A cleaning agent for use in a pre-treatment for painting and a method for preparing the same

Abstract

The present application relates to a kind of cleaning agent for coating pretreatment and its preparation method, belong to cleaning agent technical field.The present application discloses the cleaning agent for coating pretreatment includes the following weight parts raw materials: rust inhibitor 3-6 parts, corrosion inhibitor 0.1-1 part, brightener 5-10 parts, new surfactant 5-20 parts, modified silane coupling agent 0.1-2 parts, defoaming agent 0.1-1 part, water 20-30 parts.Brightener can reduce the roughness of metal surface increase luster and enhance the cleaning effect, cooperate with corrosion inhibitor to keep the luster of metal surface.Silane coupling agent has the effect of reducing surface tension to improve decontamination capacity, by nano metal particles to modify silane coupling agent, form silicon oxide film with reducibility on metal surface during cleaning.The present application can prepare the cleaning agent with good cleaning effect and corrosion resistance.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of cleaning agents, and relates to a cleaning agent for pre-painting treatment and a preparation method thereof. BACKGROUND

[0002] Metal cleaning agents mainly include acidic metal cleaning agents, alkaline metal cleaning agents, solvent-type metal cleaning agents and water-based metal cleaning agents. The water-based metal cleaning agent is a cleaning agent composed of water as a solvent, a surfactant as a main body and various additives. It is suitable for cleaning of metals such as aluminum alloy, stainless steel and copper alloy. The brightener in the cleaning agent can reduce the roughness of the metal surface and increase the gloss, but the oxide and impurities on the surface cannot be cleaned due to insufficient acid strength, or the cleaning surface is corroded due to excessive acidity. At the same time, the cleaned surface is quickly oxidized and becomes dark and yellow after drying and contacting with air.

[0003] Patent CN107760454A discloses a new disinfecting cleaning agent for sports equipment. The raw material composition of the invention includes soft water, hydrofluoric acid, dichlorotetrafluoromethane, ethanol, stabilizer, alkylphenol polyoxyethylene ether and defoaming agent. Hydrofluoric acid has a large acid mist, and the operation risk coefficient of the staff is high. At the same time, the brightness of the cleaning is not enough. SUMMARY

[0004] The present application relates to a cleaning agent for pre-painting treatment and a preparation method thereof, and belongs to the technical field of cleaning agents. The cleaning agent for pre-painting treatment disclosed by the present application comprises the following raw materials by weight: rust inhibitor 3-6 parts, corrosion inhibitor 0.1-1 part, brightener 5-10 parts, new surfactant 5-20 parts, modified silane coupling agent 0.1-2 parts, defoaming agent 0.1-1 part and water 20-30 parts. The brightener can reduce the roughness of the metal surface, increase the gloss and enhance the cleaning effect. The corrosion inhibitor can maintain the gloss of the metal surface. The silane coupling agent has the effect of reducing the surface tension and improving the decontamination ability. The silane coupling agent is modified by nano metal particles, and a silicon oxide film with reducing property is formed on the metal surface during cleaning. The cleaning agent prepared by the present application has good cleaning effect and corrosion resistance.

[0005] The object of the present application can be achieved by the following technical solutions:

[0006] A cleaning agent for pre-painting treatment, comprising the following raw materials by weight: rust inhibitor 3-6 parts, corrosion inhibitor 0.1-1 part, brightener 5-10 parts, new surfactant 5-20 parts, modified silane coupling agent 0.1-2 parts, defoaming agent 0.1-1 part and water 20-30 parts.

[0007] Further, the rust inhibitor is at least one of dodecanedioic acid, undecanedioic acid and sebacic acid, and the corrosion inhibitor is composed of both imidazoline quaternary ammonium salt and nitrate with a mass ratio of 1:1.

[0008] Further, the light enhancer is composed of sulfuric acid, citric acid and glacial acetic acid with a mass ratio of 1:8:1.5 or 1:10:3.

[0009] Further, the novel surfactant is polyoxyethylene polyoxypropylene ether block copolymer.

[0010] Further, the preparation method of the modified silane coupling agent comprises the following steps:

[0011] (1) nitrogen is introduced, methanol and monomethyl hydrogen dichlorosilane are mixed and reacted, and a mixed solution is obtained by adjusting the pH value;

[0012] (2) nano metal particles and a dispersing agent are added to the mixed solution, ultrasonic stirring is carried out, then filtration is carried out, and the filtrate is subjected to rectification to obtain the modified silane coupling agent.

[0013] Further, the mass ratio of methanol and monomethyl hydrogen dichlorosilane in the step (1) is 1:1, the reaction time and temperature are 0.5-1h and 30-40℃ respectively, and the pH value is 7-7.5.

[0014] Further, the mass ratio of the mixed solution, the nano metal particles and the dispersing agent in the step (2) is 100:0.5:2, the nano metal particles are composed of nano zinc and nano iron with a mass ratio of 1:1, the dispersing agent is acetone, and the ultrasonic time is 15-30min.

[0015] Further, the defoaming agent is at least one of polyether defoaming agent, polyether modified siloxane defoaming agent and polysiloxane defoaming agent.

[0016] Further, the preparation method of the cleaning agent used before coating is as follows:

[0017] The rust inhibitor, the corrosion inhibitor, the light enhancer, the novel surfactant, the modified silane coupling agent and water are mixed and stirred, the defoaming agent is added and stirred after the solution is in a transparent state, and the cleaning agent used before coating is obtained.

[0018] The application of the cleaning agent used before coating has the advantages that the cleaning agent is suitable for cleaning the metal surface.

[0019] The beneficial effects of the present application are as follows:

[0020] 1. The three substances of sulfuric acid, citric acid and glacial acetic acid in the light enhancer are compounded to reduce the roughness of the metal surface and increase the gloss. Meanwhile, the metal surface gloss can be maintained in cooperation with the corrosion inhibitor.

[0021] 2. The silane coupling agent has the effect of reducing surface tension to improve the decontamination ability, the silane coupling agent is modified by nano metal particles, a silicon oxide film with reducing property is formed on the metal surface during cleaning, and thus the effect of corrosion prevention can be achieved. DETAILED DESCRIPTION

[0022] In order to further illustrate the technical means and effects adopted by the present application to achieve the predetermined purposes, the specific embodiments, structures, features and effects according to the present application are described in detail as follows in combination with examples.

[0023] Example 1

[0024] A cleaning agent for pre-treatment before coating, the cleaning agent for pre-treatment before coating comprises the following raw materials by weight: 3 parts of rust inhibitor, 0.1 parts of corrosion inhibitor, 5 parts of brightener, 5 parts of new surfactant, 0.1 parts of modified silane coupling agent, 0.1 parts of defoaming agent, and 20 parts of water.

[0025] The rust inhibitor is dodecanedioic acid, and the corrosion inhibitor is composed of imidazoline quaternary ammonium salt and nitrate in a mass ratio of 1:1.

[0026] The brightener is composed of sulfuric acid, citric acid and glacial acetic acid in a mass ratio of 1:8:1.5.

[0027] The new surfactant is polyoxyethylene polyoxypropylene ether block copolymer.

[0028] The preparation method of the modified silane coupling agent comprises the following steps:

[0029] (1) nitrogen is introduced, methanol and monomethyl hydrogen dichlorosilane are mixed and reacted, and a mixed solution is obtained by adjusting the pH value;

[0030] (2) nano metal particles and a dispersing agent are added to the mixed solution, ultrasonic stirring is performed, then filtration is performed, and the filtrate is subjected to rectification to obtain the modified silane coupling agent.

[0031] In the step (1), the mass ratio of methanol and monomethyl hydrogen dichlorosilane is 1:1, the reaction time and temperature are 0.5 h and 30°C respectively, and the pH value is 7.

[0032] In the step (2), the mass ratio of the mixed solution, nano metal particles and the dispersing agent is 100:0.5:2, the nano metal particles are composed of nano zinc and nano iron in a mass ratio of 1:1, the dispersing agent is acetone, and the ultrasonic time is 20 min.

[0033] The defoaming agent is a polyether defoaming agent.

[0034] The preparation method of the cleaning agent used in the pre-painting treatment is as follows:

[0035] 3 parts by weight of the rust inhibitor, 0.1 parts by weight of the corrosion inhibitor, 5 parts by weight of the brightener, 5 parts by weight of the novel surfactant, 0.1 parts by weight of the modified silane coupling agent and 20 parts by weight of water are mixed and stirred, 0.1 parts by weight of the defoaming agent is added and stirred after the solution is in a transparent state, to obtain the cleaning agent used in the pre-painting treatment.

[0036] The application of the cleaning agent used in the pre-painting treatment has the advantages that the cleaning agent is suitable for cleaning the metal surface.

[0037] Example 2

[0038] A cleaning agent used in the pre-painting treatment, the cleaning agent used in the pre-painting treatment comprises the following raw materials by weight: rust inhibitor 5 parts, corrosion inhibitor 0.5 parts, brightener 8 parts, novel surfactant 13 parts, modified silane coupling agent 1 part, defoaming agent 0.5 parts, water 25 parts.

[0039] The rust inhibitor is dodecanedioic acid, and the corrosion inhibitor is composed of imidazoline quaternary ammonium salt and nitrate in a mass ratio of 1:1.

[0040] The brightener is composed of sulfuric acid, citric acid and glacial acetic acid in a mass ratio of 1:8:1.5.

[0041] The novel surfactant is a polyoxyethylene polyoxypropylene ether block copolymer.

[0042] The preparation method of the modified silane coupling agent comprises the following steps:

[0043] (1) nitrogen is introduced, methanol and monomethyl hydrogen dichlorosilane are mixed and reacted, and a mixed solution is obtained by adjusting the pH value;

[0044] (2) nano metal particles and a dispersing agent are added to the mixed solution, ultrasonic stirring is performed, then filtration is performed, and the filtrate is subjected to rectification to obtain the modified silane coupling agent.

[0045] The mass ratio of methanol and monomethyl hydrogen dichlorosilane in step (1) is 1:1, the reaction time and temperature are 0.5 h and 30°C respectively, and the pH value is 7.

[0046] The mass ratio of the mixed solution, nano metal particles and the dispersing agent in step (2) is 100:0.5:2, the nano metal particles are composed of nano zinc and nano iron in a mass ratio of 1:1, the dispersing agent is acetone, and the ultrasonic time is 20 min.

[0047] The defoaming agent is a polyether defoaming agent.

[0048] The preparation method of the cleaning agent used in the pre-painting treatment is as follows:

[0049] 5 parts by weight of the rust inhibitor, 0.5 parts by weight of the corrosion inhibitor, 8 parts by weight of the brightener, 13 parts by weight of the new surfactant, 1 part by weight of the modified silane coupling agent and 25 parts by weight of water are mixed and stirred, 0.5 parts by weight of the defoaming agent is added and stirred after the solution is in a transparent state, to obtain the cleaning agent used in the pre-painting treatment.

[0050] The application of the above-mentioned cleaning agent used in the pre-painting treatment is suitable for cleaning the metal surface.

[0051] Example 3

[0052] A cleaning agent used in the pre-painting treatment, the cleaning agent used in the pre-painting treatment comprises the following raw materials by weight: rust inhibitor 6 parts, corrosion inhibitor 1 part, brightener 10 parts, new surfactant 20 parts, modified silane coupling agent 2 parts, defoaming agent 1 part, water 30 parts.

[0053] The rust inhibitor is dodecanedioic acid, and the corrosion inhibitor is composed of imidazoline quaternary ammonium salt and nitrate in a mass ratio of 1:1.

[0054] The brightener is composed of sulfuric acid, citric acid and glacial acetic acid in a mass ratio of 1:8:1.5.

[0055] The new surfactant is a polyoxyethylene polyoxypropylene ether block copolymer.

[0056] The preparation method of the modified silane coupling agent comprises the following steps:

[0057] (1) nitrogen is introduced, methanol and monomethyl hydrogen dichlorosilane are mixed and reacted, and the pH value is adjusted to obtain a mixed solution;

[0058] (2) nano metal particles and a dispersing agent are added to the mixed solution, ultrasonic stirring is performed, then filtration is performed, and the filtrate is subjected to rectification to obtain the modified silane coupling agent.

[0059] The mass ratio of methanol and monomethyl hydrogen dichlorosilane in step (1) is 1:1, the reaction time and temperature are 0.5 h and 30°C respectively, and the pH value is 7.

[0060] The mass ratio of the mixed solution, nano metal particles and the dispersing agent in step (2) is 100:0.5:2, the nano metal particles are composed of nano zinc and nano iron in a mass ratio of 1:1, the dispersing agent is acetone, and the ultrasonic time is 20 min.

[0061] The defoaming agent is a polyether defoaming agent.

[0062] The preparation method of the cleaning agent used in the pre-painting treatment is as follows:

[0063] 6 parts by weight of rust preventive, 1 part by weight of corrosion inhibitor, 10 parts by weight of brightener, 20 parts by weight of novel surfactant, 2 parts by weight of modified silane coupling agent and 30 parts by weight of water are mixed and stirred, 1 part by weight of defoaming agent is added and stirred after the solution is in transparent state, to obtain the cleaning agent for pre-treatment before painting.

[0064] The application of the cleaning agent for pre-treatment before painting described above is suitable for cleaning of metal surface.

[0065] Comparative Example 1

[0066] On the basis of Example 2, a cleaning agent for pre-treatment before painting comprises the following parts by weight of raw materials: rust preventive 5 parts, corrosion inhibitor 0.5 parts, brightener 8 parts, novel surfactant 13 parts, modified silane coupling agent 1 part, defoaming agent 0.5 parts, water 25 parts.

[0067] The rust preventive is dodecanedioic acid, and the corrosion inhibitor is composed of imidazoline quaternary ammonium salt and nitrate in a mass ratio of 1:1.

[0068] The brightener is composed of citric acid and glacial acetic acid in a mass ratio of 9:1.5.

[0069] The novel surfactant is polyoxyethylene polyoxypropylene ether block copolymer.

[0070] The preparation method of the modified silane coupling agent comprises the following steps:

[0071] (1) nitrogen is introduced, methanol and monomethyl hydrogen dichlorosilane are mixed and reacted, and a mixed solution is obtained by adjusting pH value;

[0072] (2) nano metal particles and dispersant are added to the mixed solution, ultrasonic stirring is performed, then filtration is performed, and the filtrate is subjected to rectification to obtain the modified silane coupling agent.

[0073] The mass ratio of methanol and monomethyl hydrogen dichlorosilane in step (1) is 1:1, the reaction time and temperature are 0.5 h and 30℃ respectively, and the pH value is 7.

[0074] The mass ratio of the mixed solution, nano metal particles and dispersant in step (2) is 100:0.5:2, the nano metal particles are composed of nano zinc and nano iron in a mass ratio of 1:1, the dispersant is acetone, and the ultrasonic time is 20 min.

[0075] The defoaming agent is polyether defoaming agent.

[0076] The preparation method of the cleaning agent for pre-treatment before painting is as follows:

[0077] 5 parts by weight of rust preventive, 0.5 parts by weight of corrosion inhibitor, 8 parts by weight of brightener, 13 parts by weight of novel surfactant, 1 part by weight of modified silane coupling agent and 25 parts by weight of water are mixed and stirred, a defoaming agent of 0.5 parts by weight is added and stirred after the solution is in a transparent state, to obtain a cleaning agent for pre-treatment before coating.

[0078] The application of the cleaning agent for pre-treatment before coating described above is suitable for cleaning of metal surfaces.

[0079] Comparative Example 2

[0080] On the basis of Example 2, a cleaning agent for pre-treatment before coating comprises the following parts by weight of raw materials: rust preventive 5 parts, corrosion inhibitor 0.5 parts, brightener 8 parts, novel surfactant 13 parts, modified silane coupling agent 1 part, defoaming agent 0.5 parts, water 25 parts.

[0081] The rust preventive is dodecanedioic acid, and the corrosion inhibitor is composed of imidazoline quaternary ammonium salt and nitrate in a mass ratio of 1:1.

[0082] The brightener is composed of sulfuric acid and glacial acetic acid in a mass ratio of 9:1.5.

[0083] The novel surfactant is polyoxyethylene polyoxypropylene ether block copolymer.

[0084] The preparation method of the modified silane coupling agent comprises the following steps:

[0085] (1) nitrogen is introduced, methanol and monomethyl hydrogen dichlorosilane are mixed and reacted, and a mixed solution is obtained by adjusting the pH value;

[0086] (2) nano metal particles and a dispersing agent are added to the mixed solution, ultrasonic stirring is performed, then filtration is performed, and the filtrate is subjected to rectification to obtain a modified silane coupling agent.

[0087] The mass ratio of methanol and monomethyl hydrogen dichlorosilane in step (1) is 1:1, the reaction time and temperature are 0.5 h and 30°C respectively, and the pH value is 7.

[0088] The mass ratio of the mixed solution, nano metal particles and dispersing agent in step (2) is 100:0.5:2, the nano metal particles are composed of nano zinc and nano iron in a mass ratio of 1:1, the dispersing agent is acetone, and the ultrasonic time is 20 min.

[0089] The defoaming agent is a polyether defoaming agent.

[0090] The preparation method of the cleaning agent for pre-treatment before coating is as follows:

[0091] 5 parts by weight of rust preventive, 0.5 parts by weight of corrosion inhibitor, 8 parts by weight of brightener, 13 parts by weight of novel surfactant, 1 part by weight of modified silane coupling agent and 25 parts by weight of water are mixed and stirred, a defoaming agent of 0.5 parts by weight is added and stirred after the solution is in a transparent state, to obtain a cleaning agent for pre-treatment before coating.

[0092] The application of the cleaning agent for pre-treatment before coating described above is suitable for cleaning of metal surfaces.

[0093] Comparative Example 3

[0094] On the basis of Example 2, a cleaning agent for pre-treatment before coating comprises the following parts by weight of raw materials: rust preventive 5 parts, corrosion inhibitor 0.5 parts, brightener 8 parts, novel surfactant 13 parts, modified silane coupling agent 1 part, defoaming agent 0.5 parts, water 25 parts.

[0095] The rust preventive is dodecanedioic acid, and the corrosion inhibitor is composed of imidazoline quaternary ammonium salt and nitrate in a mass ratio of 1:1.

[0096] The brightener is composed of sulfuric acid and citric acid in a mass ratio of 1:9.5.

[0097] The novel surfactant is polyoxyethylene polyoxypropylene ether block copolymer.

[0098] The preparation method of the modified silane coupling agent comprises the following steps:

[0099] (1) nitrogen is introduced, methanol and monomethyl hydrogen dichlorosilane are mixed and reacted, and a mixed solution is obtained by adjusting the pH value;

[0100] (2) nano metal particles and a dispersing agent are added to the mixed solution, ultrasonic stirring is performed, then filtration is performed, and the filtrate is subjected to rectification to obtain a modified silane coupling agent.

[0101] In step (1), the mass ratio of methanol and monomethyl hydrogen dichlorosilane is 1:1, the reaction time and temperature are 0.5 h and 30°C respectively, and the pH value is 7.

[0102] In step (2), the mass ratio of the mixed solution, nano metal particles and the dispersing agent is 100:0.5:2, the nano metal particles are composed of nano zinc and nano iron in a mass ratio of 1:1, the dispersing agent is acetone, and the ultrasonic time is 20 min.

[0103] The defoaming agent is a polyether defoaming agent.

[0104] The preparation method of the cleaning agent for pre-treatment before coating is as follows:

[0105] 5 parts by weight of rust preventive, 0.5 parts by weight of corrosion inhibitor, 8 parts by weight of brightener, 13 parts by weight of novel surfactant, 1 part by weight of modified silane coupling agent and 25 parts by weight of water are mixed and stirred, a defoaming agent of 0.5 parts by weight is added and stirred after the solution is in a transparent state, to obtain a cleaning agent for pre-treatment before coating.

[0106] The application of the cleaning agent for pre-treatment before coating described above is suitable for cleaning of metal surfaces.

[0107] Comparative Example 4

[0108] On the basis of Example 2, a cleaning agent for pre-treatment before coating comprises the following parts by weight of raw materials: rust preventive 5 parts, corrosion inhibitor 0.5 parts, brightener 8 parts, novel surfactant 13 parts, modified silane coupling agent 1 part, defoaming agent 0.5 parts, water 25 parts.

[0109] The rust preventive is dodecanedioic acid, and the corrosion inhibitor is nitrate.

[0110] The brightener is composed of sulfuric acid, citric acid and glacial acetic acid with a mass ratio of 1:8:1.5.

[0111] The novel surfactant is polyoxyethylene polyoxypropylene ether block copolymer.

[0112] The preparation method of the modified silane coupling agent comprises the following steps:

[0113] (1) nitrogen is introduced, methanol and monomethyl hydrogen dichlorosilane are mixed and reacted, and a mixed solution is obtained by adjusting the pH value;

[0114] (2) nano metal particles and a dispersing agent are added to the mixed solution, ultrasonic stirring is performed, then filtration is performed, and the filtrate is subjected to rectification to obtain a modified silane coupling agent.

[0115] In step (1), the mass ratio of methanol and monomethyl hydrogen dichlorosilane is 1:1, the reaction time and temperature are 0.5 h and 30°C respectively, and the pH value is 7.

[0116] In step (2), the mass ratio of the mixed solution, nano metal particles and dispersing agent is 100:0.5:2, the nano metal particles are composed of nano zinc and nano iron with a mass ratio of 1:1, the dispersing agent is acetone, and the ultrasonic time is 20 min.

[0117] The defoaming agent is a polyether defoaming agent.

[0118] The preparation method of the cleaning agent for pre-treatment before coating is as follows:

[0119] 5 parts by weight of rust preventive, 0.5 parts by weight of corrosion inhibitor, 8 parts by weight of brightener, 13 parts by weight of novel surfactant, 1 part by weight of modified silane coupling agent and 25 parts by weight of water are mixed and stirred, a defoaming agent of 0.5 parts by weight is added and stirred after the solution is in a transparent state, to obtain a cleaning agent for pre-treatment before coating.

[0120] The application of the cleaning agent for pre-treatment before coating described above is suitable for cleaning of metal surfaces.

[0121] Comparative Example 5

[0122] On the basis of Example 2, a cleaning agent for pre-treatment before coating comprises the following parts by weight of raw materials: rust preventive 5 parts, corrosion inhibitor 0.5 parts, brightener 8 parts, novel surfactant 13 parts, modified silane coupling agent 1 part, defoaming agent 0.5 parts, water 25 parts.

[0123] The rust preventive is dodecanedioic acid, and the corrosion inhibitor is imidazoline quaternary ammonium salt.

[0124] The brightener is composed of sulfuric acid, citric acid and glacial acetic acid with a mass ratio of 1:8:1.5.

[0125] The novel surfactant is polyoxyethylene polyoxypropylene ether block copolymer.

[0126] The preparation method of the modified silane coupling agent comprises the following steps:

[0127] (1) nitrogen is introduced, methanol and monomethyl hydrogen dichlorosilane are mixed and reacted, and a mixed solution is obtained by adjusting the pH value;

[0128] (2) nano metal particles and a dispersing agent are added to the mixed solution, ultrasonic stirring is performed, then filtration is performed, and the filtrate is subjected to rectification to obtain a modified silane coupling agent.

[0129] In step (1), the mass ratio of methanol and monomethyl hydrogen dichlorosilane is 1:1, the reaction time and temperature are 0.5 h and 30°C respectively, and the pH value is 7.

[0130] In step (2), the mass ratio of the mixed solution, nano metal particles and dispersing agent is 100:0.5:2, the nano metal particles are composed of nano zinc and nano iron with a mass ratio of 1:1, the dispersing agent is acetone, and the ultrasonic time is 20 min.

[0131] The defoaming agent is a polyether defoaming agent.

[0132] The preparation method of the cleaning agent for pre-treatment before coating is as follows:

[0133] 5 parts by weight of rust preventive, 0.5 parts by weight of corrosion inhibitor, 8 parts by weight of brightener, 13 parts by weight of new surfactant, 1 part by weight of modified silane coupling agent and 25 parts by weight of water are mixed and stirred, 0.5 parts by weight of defoaming agent is added and stirred after the solution is in transparent state, to obtain the cleaning agent for pre-treatment before coating.

[0134] The application of the cleaning agent for pre-treatment before coating described above is suitable for cleaning of metal surface.

[0135] Comparative Example 6

[0136] On the basis of Example 2, a cleaning agent for pre-treatment before coating comprises the following raw materials by weight: rust preventive 5 parts, corrosion inhibitor 0.5 parts, brightener 8 parts, new surfactant 13 parts, silane coupling agent 1 part, defoaming agent 0.5 parts, water 25 parts.

[0137] The rust preventive is dodecanedioic acid, and the corrosion inhibitor is composed of imidazoline quaternary ammonium salt and nitrate in a mass ratio of 1:1.

[0138] The brightener is composed of sulfuric acid, citric acid and glacial acetic acid in a mass ratio of 1:8:1.5.

[0139] The new surfactant is polyoxyethylene polyoxypropylene ether block copolymer.

[0140] The silane coupling agent is methyltrimethoxysilane.

[0141] The defoaming agent is polyether defoaming agent.

[0142] The preparation method of the cleaning agent for pre-treatment before coating is as follows:

[0143] 5 parts by weight of rust preventive, 0.5 parts by weight of corrosion inhibitor, 8 parts by weight of brightener, 13 parts by weight of new surfactant, 1 part by weight of silane coupling agent and 25 parts by weight of water are mixed and stirred, 0.5 parts by weight of defoaming agent is added and stirred after the solution is in transparent state, to obtain the cleaning agent for pre-treatment before coating.

[0144] The application of the cleaning agent for pre-treatment before coating described above is suitable for cleaning of metal surface

[0145] 1. Cleaning performance test

[0146] The cleaning agent for pre-treatment before coating prepared in Examples 1-3 and Comparative Examples 1-3 is used as sample. The sample is tested according to the cleaning rate test method of metal cleaning agent standard GB / T35759-2017; the sample is tested for surface cleanliness according to GB / T18570.9-2005. The test results are shown in Table 1.

[0147] Table 1 Results of cleaning performance test

[0148]

[0149] As can be seen from Table 1, the cleaning rate and surface cleanliness of Examples 1-3 are greater than those of Comparative Examples 1-3. The three substances of sulfuric acid, citrine and glacial acetic acid in the gloss enhancer are compounded to reduce the roughness of the metal surface and increase the gloss, thereby enhancing the cleaning effect.

[0150] 2. Corrosion and corrosion resistance test

[0151] Corrosion: The cleaning agents prepared by Examples 1-3 for use in pre-coating treatment are used as samples. Different material metal test pieces (aluminum, zinc, iron, copper) are respectively placed in the sample stock solution for immersion for 120 h. According to the copper sheet corrosion test results in GB / T 5096, the discoloration range belongs to level 1 and is normal, no deformation of the metal test piece is observed, and the mass before and after has no change or the change is less than 0.05%, which is non-corrosive.

[0152] Corrosion resistance: The cleaning agents prepared by Examples 1-3 and Comparative Examples 4-6 for use in pre-coating treatment are used as samples. The same size iron pieces are cleaned with the samples, and then placed for 24 h. The change in luminosity is observed and compared. The results of the corrosion and corrosion resistance tests are shown in Table 2.

[0153] Table 2 Results of corrosion and corrosion resistance test

[0154]

[0155] As can be seen from Table 2, the metal surface in Examples 1-3 has no corrosion change in the corrosion test and the corrosion resistance test. The metal surface of Comparative Examples 4-6 has rust in the corrosion resistance test. The corrosion inhibitor can maintain the gloss of the metal surface, the silane coupling agent has the effect of reducing the surface tension to improve the decontamination ability, and the silane coupling agent is modified by the nano metal particles to form a silicon oxide film with reducing property on the metal surface during cleaning, thereby achieving the effect of corrosion resistance.

[0156] The above is only the preferred embodiment of the present application, and does not limit the present application in any form. Although the present application has been disclosed as the above preferred embodiment, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to the above disclosed technical content without departing from the scope of the technical solution of the present application to obtain equivalent embodiments with equivalent changes. Any modification, change, equivalent change and modification of the above embodiments made according to the technical essence of the present application still belong to the scope of the technical solution of the present application.

Claims

1. A cleaning agent for use in a pre-treatment of painting, characterized by, The cleaning agent used in the pre-painting treatment comprises the following raw materials by weight: rust inhibitor 3-6 parts, corrosion inhibitor 0.1-1 part, brightener 5-10 parts, surfactant 5-20 parts, modified silane coupling agent 0.1-2 parts, defoaming agent 0.1-1 part, and water 20-30 parts; The preparation method of the modified silane coupling agent comprises the following steps: (1) nitrogen is introduced, methanol and monomethyl hydrogen dichlorosilane are mixed and reacted, and a mixed solution is obtained by adjusting the pH value; (2) nano metal particles and a dispersing agent are added to the mixed solution, ultrasonic stirring is performed, then filtration is performed, and the filtrate is subjected to rectification to obtain the modified silane coupling agent; The rust inhibitor is at least one of dodecanedioic acid, undecanedioic acid and sebacic acid, and the corrosion inhibitor is composed of imidazoline quaternary ammonium salt and nitrate at a mass ratio of 1:1; The brightener is composed of sulfuric acid, citric acid and glacial acetic acid at a mass ratio of 1:8:1.5 or 1:10:3; In the step (1), the mass ratio of methanol and monomethyl hydrogen dichlorosilane is 1:1, the reaction time and temperature are 0.5-1 h and 30-40℃ respectively, and the pH value is 7-7.5; In the step (2), the mass ratio of the mixed solution, nano metal particles and a dispersing agent is 100:0.5:2, the nano metal particles are composed of nano zinc and nano iron at a mass ratio of 1:1, the dispersing agent is acetone, and the ultrasonic time is 15-30 min.

2. The cleaning agent for use in pretreatment before painting according to claim 1, characterized by, The surfactant is a polyoxyethylene polyoxypropylene ether block copolymer.

3. The cleaning agent for use in pretreatment before painting according to claim 1, characterized by, The defoaming agent is at least one of a polyether defoaming agent, a polyether modified siloxane defoaming agent and a polysiloxane defoaming agent.

4. The cleaning agent for use in pretreatment before painting according to claim 1, wherein The preparation method of the cleaning agent used in the pre-painting treatment is as follows: The rust inhibitor, the corrosion inhibitor, the brightener, the surfactant, the modified silane coupling agent and water are mixed and stirred, the defoaming agent is added and stirred after the solution is in a transparent state, and the cleaning agent used in the pre-painting treatment is obtained.

5. Use of the cleaning agent for a pre-painting treatment according to any one of claims 1 to 4, characterized in that, The cleaning agent is suitable for cleaning the surface of a metal.

Images