Preparation method and application of an alkaline degreasing agent

Abstract

The present invention relates to the technical field of metal processing, and specifically to a preparation method and application of an alkaline degreasing agent. It includes the following steps: Step 1: First, cholesterol chloroformate and cysteamine undergo an ammonolysis reaction, then a click reaction with ethylene oxide, and finally polymerization is initiated to obtain surfactant A; Step 2: First, cholesterol chloroformate and bis(2-aminophenyl) disulfide undergo an ammonolysis reaction, and then an alcoholysis reaction with tea polyphenols to obtain surfactant B; Step 3: Prepare a chelating agent; formulate to obtain the alkaline degreasing agent. The alkaline degreasing agent includes the following components: The content of each component is: 5-15 g / L of sodium hydroxide, 10-20 g / L of sodium carbonate, 30-100 g / L of sodium phosphate, 5-7 g / L of sodium pyrophosphate, 2-5 g / L of sodium gluconate, 20-30 g / L of surfactant A, 10-20 g / L of surfactant B, 3-6 g / L of chelating agent, and the rest is deionized water.

Description

Technical Field

[0001] The present invention relates to the technical field of metal processing, and specifically to a preparation method and application of an alkaline degreasing agent. Background Art

[0002] In the electroplating industry, degreasing the metal surface is a very important pretreatment process before electroplating. If the pretreatment is not carried out to remove the oil film formed by contamination during the processing, it will affect the quality of subsequent electroplating processing. As a chemical agent for removing oil stains, grease, and dirt on the metal surface, the degreasing mechanism of the metal degreasing agent is to remove mineral oil, polishing paste, lubricating oil, powder scale, metal filings, fingerprints, etc. on the metal surface through saponification, emulsification, wetting, solubilization, dispersion, dissolution, micro-etching, etc., to ensure the stable progress of subsequent processing. The degreasing agent commonly used in the electroplating industry is an alkaline degreasing agent, which mostly contains strong alkaline substances such as sodium hydroxide and potassium hydroxide and surfactants as the main components. However, in actual applications, the commonly used alkaline degreasing agents still have insufficient cleaning power, which affects the deposition of metal ions and causes defects such as peeling and blistering of the coating.

[0003] In summary, the present invention will prepare an alkaline degreasing agent with higher cleaning power and apply it to the cleaning of electroplated metal substrates to improve the electroplating quality. Summary of the Invention

[0004] The purpose of the present invention is to provide a preparation method and application of an alkaline degreasing agent to solve the problems raised in the above background art.

[0005] To solve the above technical problems, the present invention provides the following technical solutions:

[0006] A preparation method of an alkaline degreasing agent includes the following steps:

[0007] Step 1: Perform an ammonolysis reaction with cholesteryl chloroformate and cysteamine to introduce a mercapto group, then perform a click reaction with ethylene oxide, and finally initiate polymerization to obtain surfactant A with a polyoxyethylene ether structure;

[0008] Step 2: First perform an ammonolysis reaction with cholesteryl chloroformate and bis(2-aminophenyl) disulfide, and then perform an alcoholysis reaction with tea polyphenols to obtain surfactant B;

[0009] Step 3: Prepare a chelating agent; and mix it with sodium hydroxide, sodium carbonate, sodium phosphate, sodium pyrophosphate, sodium gluconate, surfactant A, surfactant B, etc. to prepare an alkaline degreasing agent.

[0010] Further, the alkaline degreasing agent comprises the following components: by weight: 5-15 g / L of sodium hydroxide, 10-20 g / L of sodium carbonate, 30-100 g / L of sodium phosphate, 5-7 g / L of sodium pyrophosphate, 2-5 g / L of sodium gluconate, 20-30 g / L of surfactant A, 10-20 g / L of surfactant B, 3-6 g / L of chelating agent, and the balance being deionized water.

[0011] Further, the preparation method of the surfactant A is as follows: (1) Dissolve cholesterol chloroformate and cysteamine in sufficient ethanol respectively to prepare a cholesterol chloroformate solution and a cysteamine solution; (2) At room temperature, dropwise add the cholesterol chloroformate solution into the cysteamine solution drop by drop with stirring within 1-3 h. After the addition is complete, continue to react for 16-24 h to obtain reaction solution A; (3) Weigh a certain amount of ethylene oxide and divide it into two parts, A and B. Add ethylene oxide A and a photoinitiator to reaction solution A, and then perform ultrasonic dispersion treatment for 5-15 min. Then, irradiate with ultraviolet light at 365 nm for 30-60 min to end the reaction and obtain reaction solution B; (4) Under a nitrogen atmosphere, add ethylene oxide B and DMC to reaction solution B, perform ultrasonic dispersion treatment for 5-15 min, then adjust the temperature to 50-80 °C, and react for 3-6 h to obtain surfactant A.

[0012] Further, the mass ratio of the cholesterol chloroformate, cysteamine, and ethylene oxide is (5.85-6):1:(2-20).

[0013] Further, the mass ratio of ethylene oxide A and ethylene oxide B is 1:10.

[0014] Further, the photoinitiator is 0.4-2% of the mass of ethylene oxide A.

[0015] Further, the DMC is 0.25-3.7% of the mass of ethylene oxide B.

[0016] Further, the preparation method of surfactant B is as follows: (1) Dissolve cholesterol chloroformate in sufficient ethanol to prepare a cholesterol chloroformate solution. Separately, weigh a certain amount of bis(2-aminophenyl) disulfide and dissolve it in a mixed solution of ethanol and pyridine to prepare a bis(2-aminophenyl) disulfide solution; (2) At room temperature, dropwise add the cholesterol chloroformate solution to the bis(2-aminophenyl) disulfide solution with stirring within 1 - 3 h. After the addition is complete, continue the reaction for 2 - 4 h. Evaporate ethanol under reduced pressure, then wash with deionized water 2 - 3 times. Add sufficient anhydrous sodium sulfate for drying, and then filter to obtain product A; (3) Dissolve the reaction product A in sufficient ethanol. After it is completely dissolved, add sodium hydroxide and tea polyphenols, adjust the temperature to 30 - 60 °C, and stir and react at a rotation speed of 200 - 500 r / min for 12 - 24 h. After the reaction is completed, evaporate ethanol under reduced pressure, wash with deionized water 2 - 3 times, and finally dry at room temperature to obtain surfactant B.

[0017] Further, the mass ratio of cholesterol chloroformate to bis(2-aminophenyl) disulfide is 1.8:1; the addition amount of pyridine in the mixed solution is 3 times the mass of cholesterol chloroformate.

[0018] Further, the mass ratio of tea polyphenols to bis(2-aminophenyl) disulfide is (1.8 - 2):1.

[0019] Further, the addition amount of sodium hydroxide is 5 - 10% of the mass of tea polyphenols.

[0020] Further, the preparation method of the chelating agent is as follows: (1) Mix 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone with a 70% ethanol solution to prepare a 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone solution, and adjust the pH value to 5.5 - 6.5 with sodium hydroxide. Adjust the temperature to 60 - 80 °C, add sodium persulfate, stir and react for 1 - 3 h, then dropwise add an aqueous solution of 2,2`-bipyridine-3,3`-dicarboxylate sodium to the reaction solution, stir and react for 2 - 6 h, then end the reaction. Wait for the solution system to cool naturally to room temperature, and then filter, wash, and dry to obtain the chelating agent.

[0021] Further, the concentration of the 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone solution is 25 - 30 g / L, and the concentration of the aqueous solution of 2,2`-bipyridine-3,3`-dicarboxylate sodium is 7 - 8.5 g / L.

[0022] Further, the mass ratio of 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone, sodium persulfate, and 2,2`-bipyridine-3,3`-dicarboxylate sodium is (3 - 4):1:(0.1 - 0.5).

[0023] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: Two surfactants are added to the alkaline degreasing agent obtained in the present invention. The preparation methods of the two surfactants are simple and easy to operate and control, and there are few side reactions. Surfactant A is a surfactant with a polyoxyethylene ether structure, which has good penetration, emulsification, wetting, and dispersion properties, can reduce the surface tension of the solution, promote the emulsification effect, and has excellent cleaning ability. However, this surfactant has a certain degree of irritation. In order to alleviate this irritation, a surfactant B is prepared in the alkaline degreasing agent of the present invention. This surfactant connects tea polyphenols and cholesteryl chloroformate through a disulfide bond and has a stable structure. This surfactant has a large number of hydroxyl groups, which can further reduce the surface tension of water and improve the cleaning strength. However, due to the excessive number of hydroxyl groups, a large amount of foam will be generated, which is not conducive to thorough cleaning. Surfactant A has a certain defoaming ability, and the two cooperate with each other to make the alkaline degreasing agent have the properties of low irritation and high efficiency. A chelating agent is also prepared to disperse impurity metals in cooperation with the surfactant to prevent deposition and affect the cleaning of the electroplated board. Finally, phosphate is added to the alkaline degreasing agent, which has a solubilizing effect on the solution and can also form a film to protect the electroplated board from corrosion. Sodium gluconate is added to prevent scaling and play a role in rust removal. An alkaline degreasing agent with high cleaning ability and capable of improving the electroplating quality is obtained comprehensively.

[0024] (1) In the present invention, cysteamine is used as a bridge to connect cholesteryl chloroformate. The amino group and acyl chloride group of the two react, and ammonolysis forms a stable amide group. At the same time, a mercapto group is also introduced, which undergoes a click reaction with ethylene oxide under the action of light irradiation, and then polymerization is initiated to obtain surfactant A with a polyoxyethylene ether structure. Surfactant B with a large number of hydroxyl groups is generated by the ammonolysis reaction of cholesteryl chloroformate with bis(2-aminophenyl) disulfide and then the alcoholysis reaction with tea polyphenols. The two surfactants cooperate to improve the performance of the alkaline degreasing agent;

[0025] (2) The present invention also prepares a chelating agent, which can promote the dispersion of other raw material substances, and at the same time cooperate with the surfactant to treat impurity metals to prevent their deposition and promote cleaning. Specific Embodiments

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0027] In the following examples, the purity of cholesterol chloroformate is 98%, CAS No.: 7144-08-3, product number: S50032 (Shanghai Yuanye Bio-Technology Co., Ltd.), the purity of cysteamine is 95%, CAS No.: 60-23-1, product number: S30723 (Shanghai Yuanye Bio-Technology Co., Ltd.), the purity of ethanol is 99% (Wuhan Jixinbang Bio-Technology Co., Ltd.), the purity of ethylene oxide is 99% (Hubei Kewode Chemical Industry Co., Ltd.), the purity of photoinitiator is 98%, CAS No. 606-28-0 (Wuhan Xinweiye Chemical Industry Co., Ltd.), the purity of DMC is 99% (Wuhan Canos Technology Co., Ltd.), the purity of bis(2-aminophenyl) disulfide is 99%, CAS No.: 1141-88-4 (Wuhan Xinxin Jiali Bio-Technology Co., Ltd.), the purity of anhydrous sodium sulfate is 99% (Jinan Xinyue Chemical Industry Co., Ltd.), the purity of sodium hydroxide is 99% (Pande (Shanghai) International Trading Co., Ltd.), the purity of tea polyphenols is 98%, CAS No.: 84650-60-2, product number: S18152 (Shanghai Yuanye Bio-Technology Co., Ltd.), the purity of 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone is 98%, product number: S19215 (Shanghai Yuanye Bio-Technology Co., Ltd.), the purity of sodium persulfate is 99% (Changzhou Jiaye Chemical Industry Co., Ltd.), the purity of 2,2'-bipyridine-3,3'-dicarboxylic acid is 97%, CAS No.: 4433-01-6, ((alpha) Zhengzhou Alpha Chemical Industry Co., Ltd.), the purity of sodium carbonate is 99% (Weifang Haizhiyuan Chemical Industry Co., Ltd.), the purity of sodium phosphate is 98% (Hubei Rishengchang New Material Technology Co., Ltd.), the purity of sodium pyrophosphate is 99% (Shanghai Yuanye Bio-Technology Co., Ltd.), the purity of sodium gluconate is 99% (Hubei Wande Chemical Industry Co., Ltd.), and the size of the 07Cr17Ni7Al stainless steel plate is 100 mm × 100 mm × 3 mm (Dongguan Delong Metals Co., Ltd.).

[0028] Example 1: A preparation method of an alkaline degreasing agent:

[0029] Step 1: Preparation method of surfactant A: (1) Dissolve 20 g of cholesterol chloroformate and 3.5 g of cysteamine in 200 mL of ethanol respectively to prepare a cholesterol chloroformate solution and a cysteamine solution; (2) At room temperature, dropwise add the cholesterol chloroformate solution into the cysteamine solution while stirring within 2 h. After the addition is complete, continue the reaction for 24 h to obtain reaction solution A; (3) Weigh 51 g of ethylene oxide and divide it into two parts, A and B. Add 4.6 g of ethylene oxide A and 0.06 g of photoinitiator to reaction solution A, then perform ultrasonic dispersion treatment for 10 min, and then irradiate with ultraviolet light at 365 nm for 45 min to end the reaction and obtain reaction solution B; (4) Under a nitrogen atmosphere, add 46.4 g of ethylene oxide B and 1.16 g of DMC to reaction solution B. After ultrasonic dispersion treatment for 10 min, adjust the temperature to 72 °C and react for 6 h to obtain surfactant A;

[0030] Step 2: Preparation method of surfactant B: (1) Dissolve 18 g of cholesterol chloroformate in 200 mL of ethanol to prepare a cholesterol chloroformate solution. Another 10 g of bis(2-aminophenyl) disulfide is dissolved in a mixed solution of 200 mL of ethanol and 54 g of pyridine to prepare a bis(2-aminophenyl) disulfide solution; (2) At room temperature, dropwise add the cholesterol chloroformate solution into the bis(2-aminophenyl) disulfide solution while stirring within 2 h. After the addition is complete, continue the reaction for 4 h, evaporate ethanol under reduced pressure, wash twice with deionized water, add an appropriate amount of anhydrous sodium sulfate for drying, and then filter to obtain product A; (3) Dissolve the reaction product A in 400 mL of ethanol. After it is completely dissolved, add 1.4 g of sodium hydroxide and 20 g of tea polyphenols, adjust the temperature to 50 °C, and stir and react at a speed of 300 r / min for 15 h. After the reaction is over, evaporate ethanol under reduced pressure, wash twice with deionized water, and finally dry at room temperature to obtain surfactant B;

[0031] Step 3: Preparation method of chelating agent: (1) Mix 10 g of 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone with 350 mL of 70% ethanol solution to prepare a 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone solution, adjust the pH value to 6.5 with sodium hydroxide, adjust the temperature to 70 °C, add 3 g of sodium persulfate, stir and react for 2 h, then drop 150 mL of 2,2`-bipyridine-3,3`-dicarboxylic acid sodium aqueous solution with a concentration of 7.5 g / L into the reaction solution, stir and react for 3 h to end the reaction. Wait for the solution system to cool naturally to room temperature, filter, wash, and dry to obtain the chelating agent;

[0032] Step 4: Mix sodium hydroxide, sodium carbonate, sodium phosphate, sodium pyrophosphate, sodium gluconate, surfactant A, surfactant B, chelating agent, etc. to prepare an alkaline degreasing agent;

[0033] An alkaline degreaser, comprising the following components: by weight: 8 g / L of sodium hydroxide, 15 g / L of sodium carbonate, 65 g / L of sodium phosphate, 7 g / L of sodium pyrophosphate, 5 g / L of sodium gluconate, 25 g / L of surfactant A, 15 g / L of surfactant B, 3 g / L of chelating agent, and the balance being deionized water.

[0034] Example 2: A preparation method of an alkaline degreaser:

[0035] Step 1: Preparation method of surfactant A: (1) Dissolve 20 g of cholesterol chloroformate and 3.4 g of cysteamine in 200 mL of ethanol respectively to prepare a cholesterol chloroformate solution and a cysteamine solution; (2) At room temperature, dropwise add the cholesterol chloroformate solution into the cysteamine solution drop by drop with stirring within 1 h. After the addition is complete, continue the reaction for 16 h to obtain reaction solution A; (3) Weigh 6.8 g of ethylene oxide and divide it into two parts, A and B. Add 0.62 g of ethylene oxide A and 0.003 g of photoinitiator to reaction solution A, then perform ultrasonic dispersion treatment for 5 min, and then irradiate with ultraviolet light at 365 nm for 30 min to end the reaction and obtain reaction solution B; (4) Under a nitrogen atmosphere, add 6.18 g of ethylene oxide B and 0.2 g of DMC to reaction solution B, perform ultrasonic dispersion treatment for 5 min, then adjust the temperature to 50 °C, and react for 3 h to obtain surfactant A;

[0036] Step 2: Preparation method of surfactant B: (1) Dissolve 18 g of cholesterol chloroformate in 200 mL of ethanol to prepare a cholesterol chloroformate solution. Separately weigh 10 g of bis(2-aminophenyl) disulfide and dissolve it in a mixed solution of 200 mL of ethanol and 54 g of pyridine to prepare a bis(2-aminophenyl) disulfide solution; (2) At room temperature, dropwise add the cholesterol chloroformate solution into the bis(2-aminophenyl) disulfide solution drop by drop with stirring within 1 h. After the addition is complete, continue the reaction for 2 h, evaporate ethanol under reduced pressure, wash twice with deionized water, add sufficient anhydrous sodium sulfate for drying, and then filter to obtain product A; (3) Dissolve the reaction product A in 400 mL of ethanol. After it is completely dissolved, add 0.9 g of sodium hydroxide and 18 g of tea polyphenols, adjust the temperature to 50 °C, and stir and react at a speed of 200 r / min for 12 h. After the reaction is completed, evaporate ethanol under reduced pressure, wash twice with deionized water, and finally dry at room temperature to obtain surfactant B;

[0037] Step 3: The preparation method of the chelating agent is as follows: (1) Mix 10 g of 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone with 400 mL of 70% ethanol solution to prepare a 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone solution, adjust the pH value to 6.5 with sodium hydroxide, adjust the temperature to 60 °C, add 2.5 g of sodium persulfate, stir and react for 1 h, then drop 50 mL of an aqueous solution of 2,2'-bipyridine-3,3'-dicarboxylate sodium with a concentration of 7.5 g / L into the reaction solution, stir and react for 2 h, then end the reaction. Wait for the solution system to cool naturally to room temperature, and after filtration, washing and drying, obtain the chelating agent;

[0038] Step 4: Mix sodium hydroxide, sodium carbonate, sodium phosphate, sodium pyrophosphate, sodium gluconate, surfactant A, surfactant B, chelating agent, etc. to prepare an alkaline degreasing agent;

[0039] An alkaline degreasing agent, comprising the following components: by weight, 8 g / L of sodium hydroxide, 15 g / L of sodium carbonate, 65 g / L of sodium phosphate, 7 g / L of sodium pyrophosphate, 5 g / L of sodium gluconate, 25 g / L of surfactant A, 15 g / L of surfactant B, 3 g / L of chelating agent, and the rest is deionized water.

[0040] Example 3: A preparation method of an alkaline degreasing agent:

[0041] Step 1: The preparation method of surfactant A: (1) Dissolve 20 g of cholesterol chloroformate and 3.3 g of cysteamine in 200 mL of ethanol respectively to prepare a cholesterol chloroformate solution and a cysteamine solution; (2) At room temperature, drop the cholesterol chloroformate solution into the cysteamine solution drop by drop with stirring within 3 h. After the dropping is completed, continue to react for 24 h to obtain reaction solution A; (3) Weigh 66 g of ethylene oxide and divide it into two parts, A and B. Add 6 g of ethylene oxide A and 1.2 g of photoinitiator to reaction solution A, then perform ultrasonic dispersion treatment for 15 min, and then irradiate with ultraviolet light of 365 nm for 60 min to end the reaction and obtain reaction solution B; (4) Under a nitrogen atmosphere, add 60 g of ethylene oxide B and 2.22 g of DMC to reaction solution B, perform ultrasonic dispersion treatment for 15 min, then adjust the temperature to 80 °C, and react for 6 h to obtain surfactant A;

[0042] Step 2: Preparation method of surfactant B: (1) Dissolve 18 g of cholesterol chloroformate in 200 mL of ethanol to prepare a cholesterol chloroformate solution. Separately, weigh 10 g of bis(2-aminophenyl) disulfide and dissolve it in a mixed solution of 200 mL of ethanol and 54 g of pyridine to prepare a bis(2-aminophenyl) disulfide solution; (2) At room temperature, dropwise add the cholesterol chloroformate solution into the bis(2-aminophenyl) disulfide solution drop by drop with stirring within 3 h. After the addition is complete, continue the reaction for 4 h. Evaporate ethanol under reduced pressure, wash with deionized water 3 times, add sufficient anhydrous sodium sulfate for drying, and then filter to obtain product A; (3) Dissolve the reaction product A in 400 mL of ethanol. After it is completely dissolved, add 2 g of sodium hydroxide and 20 g of tea polyphenols, adjust the temperature to 60 °C, stir and react at a speed of 500 r / min for 24 h. After the reaction is completed, evaporate ethanol under reduced pressure, wash with deionized water 3 times, and finally dry at room temperature to obtain surfactant B;

[0043] Step 3: Preparation method of chelating agent: (1) Mix 10 g of 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone with 400 mL of 70% ethanol solution to prepare a 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone solution, adjust the pH value to 6.5 with sodium hydroxide, adjust the temperature to 60 °C, add 3.3 g of sodium persulfate, stir and react for 3 h, then drop 220 mL of an aqueous solution of 2,2`-bipyridine-3,3`-dicarboxylate sodium with a concentration of 7.5 g / L into the reaction solution, stir and react for 6 h, then end the reaction. Wait for the solution system to cool naturally to room temperature, filter, wash, and dry to obtain the chelating agent;

[0044] Step 4: Mix sodium hydroxide, sodium carbonate, sodium phosphate, sodium pyrophosphate, sodium gluconate, surfactant A, surfactant B, chelating agent, etc. to prepare an alkaline degreasing agent;

[0045] An alkaline degreasing agent, comprising the following components: by weight, 8 g / L of sodium hydroxide, 15 g / L of sodium carbonate, 65 g / L of sodium phosphate, 7 g / L of sodium pyrophosphate, 5 g / L of sodium gluconate, 25 g / L of surfactant A, 15 g / L of surfactant B, 3 g / L of chelating agent, and the rest is deionized water.

[0046] Comparative Example 1: An alkaline degreasing agent, comprising the following components: by weight, 8 g / L of sodium hydroxide, 15 g / L of sodium carbonate, 65 g / L of sodium phosphate, 7 g / L of sodium pyrophosphate, 5 g / L of sodium gluconate, 30 g / L of surfactant A, 20 g / L of surfactant B, 3 g / L of chelating agent, and the rest is deionized water; other conditions are the same as in Example 1;

[0047] Comparative Example 2: An alkaline degreasing agent, comprising the following components: by weight: 8 g / L of sodium hydroxide, 15 g / L of sodium carbonate, 65 g / L of sodium phosphate, 7 g / L of sodium pyrophosphate, 5 g / L of sodium gluconate, 20 g / L of surfactant A, 10 g / L of surfactant B, 3 g / L of chelating agent, and the balance being deionized water; other conditions are the same as in Example 1;

[0048] Comparative Example 3: An alkaline degreasing agent, comprising the following components: by weight: 8 g / L of sodium hydroxide, 15 g / L of sodium carbonate, 65 g / L of sodium phosphate, 7 g / L of sodium pyrophosphate, 5 g / L of sodium gluconate, 20 g / L of surfactant A, 20 g / L of surfactant B, 3 g / L of chelating agent, and the balance being deionized water; other conditions are the same as in Example 1;

[0049] Comparative Example 4: Only surfactant A is added; An alkaline degreasing agent, comprising the following components: by weight: 8 g / L of sodium hydroxide, 15 g / L of sodium carbonate, 65 g / L of sodium phosphate, 7 g / L of sodium pyrophosphate, 5 g / L of sodium gluconate, 25 g / L of surfactant A, 3 g / L of chelating agent, and the balance being deionized water; other conditions are the same as in Example 1;

[0050] Comparative Example 5: Only surfactant B is added; An alkaline degreasing agent, comprising the following components: by weight: 8 g / L of sodium hydroxide, 15 g / L of sodium carbonate, 65 g / L of sodium phosphate, 7 g / L of sodium pyrophosphate, 5 g / L of sodium gluconate, 15 g / L of surfactant B, 3 g / L of chelating agent, and the balance being deionized water; other conditions are the same as in Example 1;

[0051] Comparative Example 6: The chelating agent is not added; An alkaline degreasing agent, comprising the following components: by weight: 8 g / L of sodium hydroxide, 15 g / L of sodium carbonate, 65 g / L of sodium phosphate, 7 g / L of sodium pyrophosphate, 5 g / L of sodium gluconate, 25 g / L of surfactant A, 15 g / L of surfactant B, and the balance being deionized water.

[0052] Performance test: The alkaline degreasing agents prepared in Examples 1 to 3 and Comparative Examples 1 to 6 were subjected to performance tests; 10 07Cr17Ni7Al stainless steel plates (100 mm × 100 mm × 3 mm) were taken and weighed respectively, and the weight was recorded as m0, accurate to 0.0001. Then, 2 drops of Mobil lubricating oil were dropped on each stainless steel plate and spread evenly, and the weight was recorded as m1. Then, the oil-coated stainless steel plates were respectively placed in 9 kinds of alkaline degreasing agents prepared in the examples and comparative examples and commercially available alkaline degreasing agent - B, the temperature was adjusted to 50 °C, and the degreasing treatment was carried out for 5 min. After completion, it was washed 3 times with warm water at 35 °C and dried and weighed, and the weight was recorded as m2. Finally, the degreasing rate w was calculated: w = (m1 - m2) / (m1 - m0) × 100%; Then, a water film test was carried out on the degreasing pretreated stainless steel plate: Water mist was evenly sprayed on 9 stainless steel plates respectively. If the water film on the surface of the stainless steel plate could not be continuous and patchy, it indicated that there was still residual grease and it was unqualified. If a uniform and continuous water film could be maintained on the surface of the stainless steel plate, it indicated that the grease was removed cleanly and it was qualified; Then, a layer of nickel was electroplated on the stainless steel plate, and the nickel-plated stainless steel plate was bent repeatedly at 180° (bent 90° to both sides) until it was broken. At this time, if the nickel layer did not fall off at the break, the bonding force of the nickel layer was qualified and had a high peel strength.

[0053]

[0054] Result analysis: As can be seen from the above table, the alkaline degreasing agent prepared by the present invention has good cleaning ability. Among them, surfactant A and surfactant B have an obvious synergistic effect, which can greatly improve the degreasing performance; and after being treated with this alkaline degreasing agent, the bonding force between the nickel layer and the substrate layer is also significantly improved. To sum up, the present invention prepares an alkaline degreasing agent with high cleaning ability, which can improve the bonding force between the coating layer and the substrate layer and has significance for electroplating treatment.

[0055] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A preparation method of an alkaline degreasing agent, characterized in that: It includes the following steps: Step 1: React cholesteryl chloroformate with cysteamine by ammonolysis, then carry out click reaction with ethylene oxide, and finally initiate polymerization to obtain surfactant A with a polyoxyethylene ether structure; Step 2: React cholesteryl chloroformate with bis(2-aminophenyl) disulfide by ammonolysis first, and then carry out alcoholysis reaction with tea polyphenols to obtain surfactant B; Step 3: Mix sodium hydroxide, sodium carbonate, sodium phosphate, sodium pyrophosphate, sodium gluconate, surfactant A, surfactant B, and chelating agent to prepare an alkaline degreasing agent; The preparation method of the surfactant A is as follows: (1) Dissolve cholesteryl chloroformate and cysteamine in ethanol respectively to prepare a cholesteryl chloroformate solution and a cysteamine solution; (2) At room temperature, drop the cholesteryl chloroformate solution into the cysteamine solution drop by drop with stirring within 1 - 3 h. After the dropping is completed, continue the reaction for 16 - 24 h to obtain reaction solution A; (3) Weigh ethylene oxide and divide it into two parts, A and B. Add ethylene oxide A and a photoinitiator to reaction solution A, then perform ultrasonic dispersion treatment for 5 - 15 min, and then irradiate with ultraviolet light at 365 nm for 30 - 60 min to end the reaction and obtain reaction solution B; (4) Under a nitrogen atmosphere, add ethylene oxide B and DMC to reaction solution B, perform ultrasonic dispersion treatment for 5 - 15 min, then adjust the temperature to 50 - 80 °C, and react for 3 - 6 h to obtain surfactant A; Among them, the mass ratio of cholesteryl chloroformate, cysteamine, and ethylene oxide is (5.85 - 6):1:(2 - 20); the mass ratio of ethylene oxide A and ethylene oxide B is 1:10; the photoinitiator is 0.4 - 2% of the mass of ethylene oxide A; DMC is 0.25 - 3.7% of the mass of ethylene oxide B; The preparation method of the surfactant B is as follows: (1) Dissolve cholesteryl chloroformate in ethanol to prepare a cholesteryl chloroformate solution. Weigh another bis(2-aminophenyl) disulfide and dissolve it in a mixed solution of ethanol and pyridine to prepare a bis(2-aminophenyl) disulfide solution; (2) At room temperature, drop the cholesteryl chloroformate solution into the bis(2-aminophenyl) disulfide solution drop by drop with stirring within 1 - 3 h. After the dropping is completed, continue the reaction for 2 - 4 h, evaporate ethanol under reduced pressure, wash with deionized water 2 - 3 times, add anhydrous sodium sulfate for drying, and then filter to obtain product A; (3) Dissolve product A in ethanol. After it is completely dissolved, add sodium hydroxide and tea polyphenols, adjust the temperature to 30 - 60 °C, and stir and react at a speed of 200 - 500 r / min for 12 - 24 h. After the reaction is completed, evaporate ethanol under reduced pressure, wash with deionized water 2 - 3 times, and finally dry at room temperature to obtain surfactant B; Among them, the mass ratio of the cholesterol chloroformate to bis(2-aminophenyl) disulfide is 1.8:1; the addition amount of pyridine in the mixed solution is 3 times the mass of the cholesterol chloroformate; the mass ratio of the tea polyphenols to bis(2-aminophenyl) disulfide is (1.8 - 2):1; the addition amount of sodium hydroxide is 5 - 10% of the mass of the tea polyphenols. The alkaline degreasing agent includes the following components: the content of each component is: 5 - 15 g / L of sodium hydroxide, 10 - 20 g / L of sodium carbonate, 30 - 100 g / L of sodium phosphate, 5 - 7 g / L of sodium pyrophosphate, 2 - 5 g / L of sodium gluconate, 20 - 30 g / L of surfactant A, 10 - 20 g / L of surfactant B, 3 - 6 g / L of chelating agent, and the rest is deionized water.

2. The preparation method of an alkaline degreasing agent according to claim 1, characterized in that: The preparation method of the chelating agent is as follows: Mix 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone with a 70% ethanol solution to prepare a 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone solution, and adjust the pH value to 5.5 - 6.5 with sodium hydroxide. Adjust the temperature to 60 - 80 °C, add sodium persulfate, stir and react for 1 - 3 h, then drop the aqueous solution of 2,2'-bipyridine-3,3'-dicarboxylate sodium into the reaction solution, stir and react for 2 - 6 h, then end the reaction. Wait for the solution system to cool naturally to room temperature, and after filtration, washing, and drying, obtain the chelating agent.

3. The preparation method of an alkaline degreasing agent according to claim 2, characterized in that: The concentration of the 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone solution is 25 - 30 g / L, and the concentration of the aqueous solution of 2,2'-bipyridine-3,3'-dicarboxylate sodium is 7 - 8.5 g / L; the mass ratio of 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone, sodium persulfate, and 2,2'-bipyridine-3,3'-dicarboxylate sodium is (3 - 4):1:(0.1 - 0.5).

4. Application of an alkaline degreaser, characterized in that: The alkaline degreasing agent prepared by the preparation method of an alkaline degreasing agent according to any one of claims 1 - 3 is used for degreasing the metal surface.

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