A metal surface silanizing treatment agent and use thereof

Abstract

The application discloses a kind of metal surface silanization treating agent, by silane treating agent A and silane treating agent B composition;Vinyl silane, silicate silane is mixed to silane mixed solution, silane mixed solution is mixed with deionized water and alcohol solvent uniformly, hydrolysis reaction is carried out at room temperature, i.e. silane treating agent A;Amino silane is mixed with deionized water and alcohol solvent uniformly, hydrolysis reaction is carried out at room temperature, i.e. silane treating agent B;The application also provides a kind of metal surface silanization treating agent application, comprising the following steps: metal is treated with degreasing agent, then water washing;Subsequently, use rust remover to treat, then water washing, blow dry;The metal after pretreatment is immersed in silane treating agent A, take out and drain;Again immersed in silane treating agent B, take out and blow dry;The silanization treating agent provided by the application can greatly improve the adhesion of substrate and organic coating, and the silane film curing temperature is low, short time, suitable for industrial production.

Description

Technical Field

[0001] This invention relates to the field of metal surface coating technology, and more specifically to a metal surface silanization treatment agent and its application. Background Technology

[0002] The coating process for automotive parts and household appliances can generally be divided into two parts: surface pretreatment of the metal and coating / spraying application. Traditional phosphating is widely used in the pretreatment process, but it presents complex environmental problems related to wastewater and waste residue treatment.

[0003] Silanization is a relatively mature pretreatment technology that can replace phosphating. Silanization not only avoids the disadvantages of traditional phosphating but also has the following advantages: short processing time, fewer processing steps, and simple control; it eliminates the need for surface conditioning and passivation processes, and has a long service life; it can improve the adhesion of paint to the substrate and can process various substrates such as iron plates, galvanized plates, and aluminum plates on the same production line. However, silanization also has the following disadvantages: the silane film formed after surface treatment with existing silanizing agents is prone to detachment from subsequent coatings; its corrosion resistance is still somewhat inferior to traditional phosphating processes, failing to meet the requirements of various industries such as home appliances; and existing silanization processes lack significant industrial value and have not been widely adopted in the market.

[0004] Chinese patent document CN108250950A discloses a hydrophilic, highly corrosion-resistant silanizing agent for steel surfaces and its synthesis method. The silanizing agent consists of a silane solution, a synthetic complexing agent, and a buffer system. However, the preparation process of the silane solution and the synthetic complexing agent is relatively complex, and the properties of the silanizing agent are difficult to maintain stability.

[0005] Chinese patent document CN101476118A discloses a general metal surface silanization treatment agent, its preparation method and application. The pretreated metal is directly immersed in an aqueous phase for 25 minutes, and then dried at 80-160℃ for 30-50 minutes. The metal surface treatment method disclosed in this patent has too long curing time and silane immersion time, and the aging film formation temperature is too high, which is not conducive to industrial production.

[0006] Currently, there is an urgent need to develop a silanization agent and application process that is both versatile and practical, making silanization more suitable for industrial production. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the present invention aims to provide a metal surface silanization treatment agent and its application, which can greatly improve the adhesion between the substrate and the organic coating, has a better anti-corrosion effect than a single silane film, and has a low curing temperature and short curing time, making it suitable for industrial production.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A metal surface silanizing agent, comprising silane treatment agent A and silane treatment agent B;

[0010] The preparation method of silane treatment agent A is as follows: Vinylsilane and silicate silane are mixed to obtain a silane mixture. The silane mixture is then mixed with deionized water and an alcohol solvent at a volume ratio of 5:55-60:35-40, and a hydrolysis reaction is carried out at room temperature for 1.5-2 hours to obtain silane treatment agent A.

[0011] The preparation method of silane treatment agent B is as follows: aminosilane is mixed with deionized water and alcohol solvent at a volume ratio of 5:55-60:35-40, and hydrolysis reaction is carried out at room temperature for 1.5-2 hours to obtain silane treatment agent B.

[0012] Preferably, the vinyl silane is one or more of vinyltrimethoxysilane, vinyltriethoxysilane, or vinyltriacetoxysilane.

[0013] Preferably, the silicate silane is methyl orthosilicate and / or tetraethyl orthosilicate.

[0014] Preferably, the aminosilane is aminopropyltrimethoxysilane and / or aminopropyltriethoxysilane.

[0015] Preferably, the alcohol solvent is one or more of methanol, ethanol or n-propanol.

[0016] Preferably, the volume ratio of vinyl silane to silicate silane in the silane mixture is 3:2 to 2:3.

[0017] This invention also claims the application of the aforementioned metal surface silanizing agent in metal surface treatment, comprising the following steps:

[0018] (1) Metal pretreatment: Treat the metal with a degreasing agent at 60-70℃ for 5-30 minutes, and then wash it with water; treat it with a rust remover at 10-40℃ for 5-30 minutes, and then wash it with water and blow it dry;

[0019] (2) Preparation of silane film: Immerse the pretreated metal in silane treatment agent A, take it out and drain it; then immerse it in silane treatment agent B, take it out and blow it dry.

[0020] Preferably, in step (2), the time for immersing the metal in silane treatment agent A is 30 to 120 seconds.

[0021] Preferably, in step (2), the time for immersing the metal in silane treatment agent B is 30 to 120 seconds.

[0022] Preferably, the metal is one or more of steel, galvanized steel sheet, aluminum, and aluminum alloy.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1) This invention provides a metal surface silanization treatment agent containing vinyl and amino groups, which can match most organic coatings and greatly improve the adhesion between the substrate and the organic coating.

[0025] 2) This invention provides an application of a metal surface silanizing agent in metal surface treatment. First, silane treatment agent A is used to treat the metal, and then silane treatment agent B is used. If silane treatment agent B is used first and then silane treatment agent A is used, the residual alkaline aminosilane on the metal surface will affect the hydrolytic stability of treatment agent A. The double silane impregnation process used in this invention produces a double-layer silane film with better anti-corrosion effect than a single silane film.

[0026] 3) The metal surface silanization treatment agent provided by this invention has a high alcohol solvent content, and the solvent evaporates quickly. After the metal is impregnated with the treatment agent, it can be quickly dried with warm air to complete the curing, avoiding the disadvantages of high aging temperature and long time of conventional silanization treatment. The high alcohol content is beneficial to the stability of the silanol solution, but the system with excessive alcohol content is highly flammable. If the alcohol vapor content reaches a certain limit, it may even cause an explosion. Therefore, this invention controls the alcohol solvent content to below 40%.

[0027] 4) The hydrolysis of aminosilane is alkaline, which can catalyze the hydrolysis of silicate ester silanes to form SiO2 particles. The nano-SiO2 particles can fill the voids in the organosilane membrane. After the alcohol solvent carries the water and evaporates rapidly, the organosilane membrane shrinks sharply and forms a tight organic / inorganic hybrid membrane with the SiO2 particles embedded in the membrane. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. Of course, the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0029] Unless otherwise specified, all chemical reagents and materials in this invention are purchased from the market or synthesized from raw materials purchased from the market.

[0030] The carbon steel was purchased from Dongguan Yuegang Mold Steel Co., Ltd., model S35C.

[0031] The rust remover is a two-in-one degreaser and rust remover, model number F-101;

[0032] The degreasing agent was purchased from Shenzhen Jintenglong Industrial Co., Ltd., and the model was Evonik Tomamine AO-455.

[0033] Example 1

[0034] The application of a silanizing agent in metal surface treatment, with the following specific steps:

[0035] (1) Mix 35 mL of methanol, 3 mL of vinyltrimethoxysilane, 2 mL of methyl orthosilicate and 60 mL of deionized water evenly, and hydrolyze at room temperature for 1.5 h to obtain silane treatment agent A;

[0036] (2) Mix 35 mL of methanol, 5 mL of aminopropyltrimethoxysilane and 60 mL of deionized water evenly, and hydrolyze at room temperature for 1.5 h to obtain silane treatment agent B;

[0037] (3) Treat the surface of the carbon steel sample with degreasing agent at 60°C for 5 minutes, then rinse it with deionized water, then treat the surface of the carbon steel sample with rust remover at room temperature for 5 minutes, rinse it with deionized water, and dry it with compressed air.

[0038] (4) Immerse the pretreated metal in silane treatment agent A for 30 seconds, then remove and drain. Immerse it in silane treatment agent B for 30 seconds, then remove and drain. Dry it quickly with warm air.

[0039] Example 2

[0040] The application of a silanizing agent in metal surface treatment, with the following specific steps:

[0041] (1) Mix 40 mL of methanol, 3 mL of vinyltrimethoxysilane, 2 mL of methyl orthosilicate and 55 mL of deionized water evenly, and hydrolyze at room temperature for 1.5 h to obtain silane treatment agent A;

[0042] (2) Mix 35 mL of methanol, 5 mL of aminopropyltrimethoxysilane and 60 mL of deionized water evenly, and hydrolyze at room temperature for 1.5 h to obtain silane treatment agent B;

[0043] (3) Treat the surface of the carbon steel sample with degreasing agent at 70°C for 5 minutes, then rinse it with deionized water, then treat the surface of the carbon steel sample with rust remover at room temperature for 5 minutes, rinse it with deionized water, and dry it with compressed air.

[0044] (4) Immerse the pretreated metal in silane treatment agent A for 30 seconds, then remove and drain. Immerse it in silane treatment agent B for 30 seconds, then remove and drain. Dry it quickly with warm air.

[0045] Example 3

[0046] The application of a silanizing agent in metal surface treatment, with the following specific steps:

[0047] (1) Mix 35 mL of methanol, 3 mL of vinyltrimethoxysilane, 2 mL of methyl orthosilicate and 60 mL of deionized water evenly, and hydrolyze at room temperature for 1.5 h to obtain silane treatment agent A;

[0048] (2) Mix 40 mL of methanol, 5 mL of aminopropyltrimethoxysilane and 55 mL of deionized water evenly, and hydrolyze at room temperature for 1.5 h to obtain silane treatment agent B.

[0049] (3) Treat the surface of the carbon steel sample with degreasing agent at 60°C for 5 minutes, then rinse it with deionized water, then treat the surface of the carbon steel sample with rust remover at room temperature for 5 minutes, rinse it with deionized water, and dry it with compressed air.

[0050] (4) Immerse the pretreated metal in silane treatment agent A for 30 seconds, then remove and drain. Immerse it in silane treatment agent B for 30 seconds, then remove and drain. Dry it quickly with warm air.

[0051] Example 4

[0052] The application of a silanizing agent in metal surface treatment, with the following specific steps:

[0053] (1) Mix 40 mL of methanol, 3 mL of vinyltrimethoxysilane, 2 mL of methyl orthosilicate and 55 mL of deionized water evenly, and hydrolyze at room temperature for 1.5 h to obtain silane treatment agent A;

[0054] (2) Mix 40 mL of methanol, 5 mL of aminopropyltrimethoxysilane and 55 mL of deionized water evenly, and hydrolyze at room temperature for 1.5 h to obtain silane treatment agent B.

[0055] (3) Treat the surface of the carbon steel sample with degreasing agent at 60°C for 5 minutes, then rinse it with deionized water, then treat the surface of the carbon steel sample with rust remover at room temperature for 5 minutes, rinse it with deionized water, and dry it with compressed air.

[0056] (4) Immerse the pretreated metal in silane treatment agent A for 30 seconds, then remove and drain. Immerse it in silane treatment agent B for 30 seconds, then remove and drain. Dry it quickly with warm air.

[0057] Example 5

[0058] The application of a silanizing agent in metal surface treatment, with the following specific steps:

[0059] (1) Mix 40 mL of methanol, 3 mL of vinyltrimethoxysilane, 2 mL of methyl orthosilicate and 55 mL of deionized water evenly, and hydrolyze at room temperature for 2 h to obtain silane treatment agent A.

[0060] (2) Mix 40 mL of methanol, 5 mL of aminopropyltrimethoxysilane and 55 mL of deionized water evenly, and hydrolyze at room temperature for 2 h to obtain silane treatment agent B.

[0061] (3) Treat the surface of the carbon steel sample with degreasing agent at 60°C for 5 minutes, then rinse it with deionized water, then treat the surface of the carbon steel sample with rust remover at room temperature for 5 minutes, rinse it with deionized water, and dry it with compressed air.

[0062] (4) Immerse the pretreated metal in silane treatment agent A for 30 seconds, then remove and drain. Immerse it in silane treatment agent B for 30 seconds, then remove and drain. Dry it quickly with warm air.

[0063] Example 6

[0064] The application of a silanizing agent in metal surface treatment, with the following specific steps:

[0065] (1) Mix 40 mL of methanol, 3 mL of vinyltrimethoxysilane, 2 mL of methyl orthosilicate and 55 mL of deionized water evenly, and hydrolyze at room temperature for 2 h to obtain silane treatment agent A.

[0066] (2) Mix 40 mL of methanol, 5 mL of aminopropyltrimethoxysilane and 55 mL of deionized water evenly, and hydrolyze at room temperature for 2 h to obtain silane treatment agent B.

[0067] (3) Treat the surface of the carbon steel sample with degreasing agent at 70°C for 5 minutes, then rinse it with deionized water, then treat the surface of the carbon steel sample with rust remover at room temperature for 5 minutes, rinse it with deionized water, and dry it with compressed air.

[0068] (4) Immerse the pretreated metal in silane treatment agent A for 60 seconds, then remove and drain. Immerse it in silane treatment agent B for 30 seconds, then remove and drain. Dry it quickly with warm air.

[0069] Example 7

[0070] The application of a silanizing agent in metal surface treatment, with the following specific steps:

[0071] (1) Mix 40 mL of methanol, 3 mL of vinyltrimethoxysilane, 2 mL of methyl orthosilicate and 55 mL of deionized water evenly, and hydrolyze at room temperature for 2 h to obtain silane treatment agent A.

[0072] (2) Mix 40 mL of methanol, 5 mL of aminopropyltrimethoxysilane and 55 mL of deionized water evenly, and hydrolyze at room temperature for 2 h to obtain silane treatment agent B.

[0073] (3) Treat the surface of the carbon steel sample with degreasing agent at 60°C for 5 minutes, then rinse it with deionized water, then treat the surface of the carbon steel sample with rust remover at room temperature for 5 minutes, rinse it with deionized water, and dry it with compressed air.

[0074] (4) Immerse the pretreated metal in silane treatment agent A for 60 seconds, then remove and drain. Immerse it in silane treatment agent B for 60 seconds, then remove and drain. Dry it quickly with warm air.

[0075] Comparative Example 1

[0076] The application of a silanizing agent in metal surface treatment, with the following specific steps:

[0077] (1) Mix 40 mL of methanol, 5 mL of aminopropyltrimethoxysilane and 55 mL of deionized water evenly, and hydrolyze at room temperature for 2 h to obtain silane treatment agent B.

[0078] (2) Treat the surface of the carbon steel sample with degreasing agent at 60°C for 5 minutes, then rinse it with deionized water, then treat the surface of the carbon steel sample with rust remover at room temperature for 5 minutes, rinse it with deionized water, and dry it with compressed air.

[0079] (3) Immerse the pretreated metal in silane treatment agent B for 30 seconds, then remove and drain, and dry quickly with warm air.

[0080] Comparative Example 2

[0081] The application of a silanizing agent in metal surface treatment, with the following specific steps:

[0082] (1) Mix 40 mL of methanol, 3 mL of vinyltrimethoxysilane, 2 mL of methyl orthosilicate and 55 mL of deionized water evenly, and hydrolyze at room temperature for 2 h to obtain silane treatment agent A.

[0083] (2) Treat the surface of the carbon steel sample with degreasing agent at 60°C for 5 minutes, then rinse it with deionized water, then treat the surface of the carbon steel sample with rust remover at room temperature for 5 minutes, rinse it with deionized water, and dry it with compressed air.

[0084] (3) Immerse the pretreated metal in silane treatment agent A for 30 seconds, then remove and drain, and dry quickly with warm air.

[0085] Comparative Example 3

[0086] The application of a silanizing agent in metal surface treatment, with the following specific steps:

[0087] Treat the surface of the carbon steel sample with a degreasing agent at 60°C for 5 minutes, then rinse it with deionized water. Next, treat the surface of the carbon steel sample with a rust remover at room temperature for 5 minutes, rinse it with deionized water, and then dry it with compressed air.

[0088] The corrosion rate of the treated carbon steel in Examples 1-7 and Comparative Examples 1-3 was measured in simulated seawater using an electrochemical corrosion method. The adhesion strength between the treated carbon steel and the coating in Examples 1-7 and Comparative Examples 1-3 was measured using GB / T5210-2006 "Paints and Varnishes - Pull-off Adhesion Test". Specific data are shown in Table 1.

[0089] Table 1

[0090]

[0091]

[0092] Comparative analysis of Examples 1-7 and Comparative Examples 1-3 shows that the double-layer silane treatment process is more effective than the single-layer silane treatment process. The corrosion resistance and bonding strength of the metal are significantly improved after silanization treatment.

[0093] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A metal surface silanizing agent, characterized in that, The silanization treatment agent consists of silane treatment agent A and silane treatment agent B; The preparation method of silane treatment agent A is as follows: Vinylsilane and silicate silane are mixed to obtain a silane mixture. The silane mixture is then mixed with deionized water and an alcohol solvent at a volume ratio of 5:55-60:35-40, and a hydrolysis reaction is carried out at room temperature for 1.5-2 hours to obtain silane treatment agent A. The preparation method of silane treatment agent B is as follows: aminosilane is mixed with deionized water and alcohol solvent at a volume ratio of 5:55-60:35-40, and hydrolysis reaction is carried out at room temperature for 1.5-2 hours to obtain silane treatment agent B; The volume ratio of vinyl silane to silicate silane in the silane mixture is 3:2 to 2:3; The application of the metal surface silanizing agent in metal surface treatment includes the following steps: (1) Metal pretreatment: Treat the metal with a degreasing agent at 60-70℃ for 5-30 minutes, and then wash it with water; treat it with a rust remover at 10-40℃ for 5-30 minutes, and then wash it with water and blow it dry; (2) Preparation of silane film: Immerse the pretreated metal in silane treatment agent A, take it out and drain it; then immerse it in silane treatment agent B, take it out and blow it dry.

2. The metal surface silanizing agent according to claim 1, characterized in that, Vinylsilane is one or more of vinyltrimethoxysilane, vinyltriethoxysilane, or vinyltriacetoxysilane.

3. The metal surface silanizing agent according to claim 1, characterized in that, The silicate ester silanes are methyl orthosilicate and / or tetraethyl orthosilicate.

4. The metal surface silanizing agent according to claim 1, characterized in that, The aminosilane is aminopropyltrimethoxysilane and / or aminopropyltriethoxysilane.

5. The metal surface silanizing agent according to claim 1, characterized in that, The alcohol solvent is one or more of methanol, ethanol, or n-propanol.

6. The metal surface silanizing agent according to claim 1, characterized in that, In step (2), the metal is immersed in silane treatment agent A for 30 to 120 seconds.

7. The metal surface silanizing agent according to claim 1, characterized in that, In step (2), the metal is immersed in silane treatment agent B for 30 to 120 seconds.

8. The metal surface silanizing agent according to claim 1, characterized in that, The metal is one or more of steel, galvanized steel sheet, aluminum, and aluminum alloy.

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