A corrosion-resistant water-soluble zinc plating sealant and its preparation method and use method

Abstract

The invention discloses a corrosion-resistant water-soluble zinc plating sealant and a preparation method and a use method thereof, wherein the raw material components, by mass fraction, include 30-50% of water-based nano-ceramic resin, 0.5-5% of dispersant, 0.5-2% of defoamer, 0.1-2% of leveling agent, 5-20% of anhydrous ethanol and the balance of deionized water; the water-based nano-ceramic resin, by mass fraction, includes 5-15% of water-based acrylic polymer, 5-20% of silica sol solution, 23-40% of siloxane, 2-15% of alcohols, 10-15% of deionized water, and a trace amount of metal oxide. The sealant of the invention is firmly combined with the zinc plating layer and can withstand the use environment of 260°C to minus 80°C; it has a super salt spray corrosion resistance function, has both sealing and passivation functions, and is a new type of zinc plating sealant that is environmentally friendly, non-toxic, low-carbon, and simple in process operation.

Description

Technical Field

[0001] The invention relates to the field of coatings, and in particular to a corrosion-resistant water-soluble zinc plating sealant and a preparation method and a use method thereof. Background Art

[0002] The galvanizing sealers on the market currently have the following problems: 1) Traditional sealers contain heavy metals such as chromium and have been banned by environmental protection departments in many places; 2) Some sealers that do not contain heavy metals have poor bonding with the galvanized layer, and when the ambient temperature changes suddenly, the sealing layer will peel off, especially when the fasteners are worn and damaged during the fastening process, resulting in a significant reduction in anti-corrosion performance; 3) Some sealers are resistant to high temperature differences and will change color during the heating and decyanation process (200°C); 4) Some products require high-temperature curing after sealing, which increases energy consumption; 5) Most sealers have poor aging resistance, water resistance, salt spray resistance, and acid corrosion resistance. For example, salt spray resistance can only be achieved for about 48-72 hours, and at most 200-300 hours, which is difficult to truly meet the needs of mid- to high-end customers. Therefore, it is necessary to develop a galvanizing sealer with excellent performance. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0004] A corrosion-resistant water-soluble zinc plating sealer, the raw material components, measured by mass fraction, include 30-50% of water-based nano-ceramic resin, 0.5-5% of dispersant, 0.5-2% of defoamer, 0.1-2% of leveling agent, 5-20% of anhydrous ethanol and the balance of deionized water;

[0005] The water-based nano ceramic resin comprises, by mass fraction, 5-15% of water-based acrylic polymer, 5-20% of silica sol solution, 23-40% of siloxane, 2-15% of alcohols, 10-15% of deionized water, and a trace amount of metal oxides.

[0006] The water-based nano ceramic resin of the present invention is a water-based nano ceramic resin synthesized with siloxane and silica sol as main raw materials, and is prepared by the composite resin formula and preparation method disclosed in "A water-based nano ceramic composite coating and coating method thereof" with publication number CN106349926A. Specifically, by mass fraction, 5-15% of water-based acrylic polymer, 5-20% of silica sol solution, 23-40% of siloxane, 2-15% of alcohol, 10-15% of deionized water, and a trace amount of metal oxide are stirred at room temperature and pressure in a reactor for 20-60 minutes to react and form the water-based nano ceramic resin.

[0007] Preferably, the leveling agent is a silicone leveling agent or a fluorocarbon leveling agent, specifically one of BYK-346, TEGO-450 or EFKA-3777.

[0008] Preferably, the defoamer is a water-based coating defoamer, commonly used polydimethylsiloxane, specifically one of TEGO-810, Taiwan Zhongya F111, and Deqian 1811.

[0009] Preferably, the dispersant is a water-based coating dispersant, specifically one of AONA-5040, MOK-5035 or BYK-190.

[0010] The preparation method of the corrosion-resistant water-soluble zinc plating sealant comprises the following steps:

[0011] Step 1: Mix deionized water and ethanol evenly according to the mass fraction ratio;

[0012] Step 2: Add water-based nano-ceramic resin, dispersant, defoamer and leveling agent in proportion;

[0013] Step 3: Stir electrically for 10 minutes, let stand to defoam, and obtain a corrosion-resistant water-soluble zinc-plating sealer.

[0014] Preferably, the electric stirring speed is 1000-1500 rpm.

[0015] The method of using the corrosion-resistant water-soluble galvanized sealant is as follows: after cleaning and drying the electro-galvanized or hot-dip galvanized parts, when the surface temperature reaches 20-50°C, immerse the parts in the sealant at room temperature for 2-3 seconds to wet the parts completely and then take them out, remove excess liquid on the surface, dry them with hot air at 60-90°C for 10 minutes, and complete the sealant operation after natural cooling.

[0016] Preferably, the removal of excess liquid on the surface is carried out by centrifugal drying or blowing.

[0017] Compared with the prior art, the sealant of the present invention is prepared by using aqueous nano-ceramic composite resin as a film-forming agent, supplemented with dispersants, defoamers, leveling agents, alcohol diluents and other raw materials, and has the following beneficial effects:

[0018] 1. It is firmly bonded to the galvanized layer. The Si and O atoms in the sealant are combined with Zn to form a strong Si-O-Zn molecular structure, which can withstand the use environment of 260℃ to minus 80℃.

[0019] 2. Strong resistance to salt spray corrosion. Due to the excellent sealing effect and aging and corrosion resistance of the water-based nano-ceramic composite resin, the sealing layer has super strong resistance to salt spray corrosion. This sealant is a nano material with a particle size of only 5 nanometers. The closed film it forms is more compact (common sealants are generally above 20 nanometers), and it is difficult for corrosive factors to invade, with better sealing and protection effects; this sealant is mainly composed of an inorganic molecular structure formed by Si and O bonds, and its own aging and corrosion resistance is far better than traditional sealants based on organic components. When the thickness of the galvanized layer is 8 microns, the salt spray resistance can reach more than 720 hours after being sealed with the sealant, which is several times the sealing effect of traditional electrogalvanizing (generally 48-72 hours), and it also far exceeds the salt spray resistance of hot-dip galvanizing with a galvanized layer thickness of 80 microns (generally 480 hours).

[0020] 3. The sealant has both sealing and passivation functions. It is a new type of galvanizing sealant that is environmentally friendly, non-toxic, low-carbon, and has simple process operation.

[0021] Compared with the prior art, the preparation method and coating method of the present invention have the characteristics of simple operation and stable configuration, solve the pain points of similar products in the industry such as environmental pollution, low anti-corrosion performance and high energy consumption, and have broad prospects for application in the fields of electrogalvanizing and hot-dip galvanizing. Therefore, the sealant for galvanized products of the present invention and its preparation method and coating method have high industrial utilization value. DETAILED DESCRIPTION

[0022] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] Examples 1-5

[0024] For the convenience of expression, the proportions and product performances of the five embodiments are expressed in a table.

[0025] Table 1: Components and mass fraction (%) of galvanizing sealer

[0026]

[0027] The preparation method of the formula of Examples 1-5 in Table 1 is as follows:

[0028] Step 1: Mix deionized water and ethanol evenly according to the mass fraction ratio;

[0029] Step 2: Add water-based nano-ceramic resin, dispersant, defoamer and leveling agent in proportion;

[0030] Step 3: Stir electrically for 10 minutes at a speed of 1000-1500 rpm, and let it stand for defoaming to obtain a corrosion-resistant water-soluble zinc plating sealer.

[0031] The corrosion-resistant water-soluble galvanizing sealer prepared according to the formula of Examples 1-5 in Table 1 is used for sealing. After cleaning and drying the parts that have been electro-galvanized or hot-dip galvanized, when the surface temperature reaches 20-50°C, the parts are immersed in the sealer at room temperature for 2-3 seconds to make the parts completely wetted and then taken out, and excess liquid on the surface is removed by centrifugal drying or blowing, and hot air drying is performed at 60-90°C for 10-20 minutes. After natural cooling, the operation of the sealer is completed.

[0032] Comparative Example 1: Electrogalvanizing with common sealant, such as the formula of invention patent CN104060261A, the main ingredients are: coupled aniline, benzoic acid, ethanol, dilute acetic acid and other organic ingredients. The combination with the zinc layer is physical, and although the initial bonding strength is also very good, it is easy to peel off after the zinc layer is oxidized. Organic matter will also change color after being heated (200℃), and the anti-corrosion performance will decrease accordingly. Representative products include: ODME DM-501.

[0033] Comparative Example 2: Hot-dip galvanizing. Hot-dip galvanizing is a traditional galvanizing method, which is an anti-corrosion coating method in which zinc is applied to the metal surface in a molten state. The reference standard is: GB-T13912-2002.

[0034] Table 2: Performance test data of zinc plating sealants of Examples 1-5 and Comparative Examples 1-2

[0035]

[0036] Note: The temperature of the high temperature test is 200℃, which simulates the dehydrogenation process (a part of the galvanizing process)

[0037] The neutral salt spray test is carried out in accordance with the standard of GB / T 10125-1997 "Artificial atmosphere corrosion test-Salt spray test".

[0038] The preparation method and coating method of the present invention have the characteristics of simple operation and stable configuration, solve the pain points of similar products in the industry such as environmental pollution, low anti-corrosion performance and high energy consumption, and have broad prospects for application in the fields of electrogalvanizing and hot-dip galvanizing. Therefore, the sealing agent for galvanized products of the present invention and its preparation method and coating method have high industrial utilization value.

[0039] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

Claims

1. A corrosion-resistant water-soluble zinc plating sealant, characterized in that: The raw materials are composed of the following components by mass fraction: 30-50% of water-based nano-ceramic resin, 0.5-5% of dispersant, 0.5-2% of defoamer, 0.1-2% of leveling agent, 5-20% of anhydrous ethanol and the balance of deionized water; The water-based nano-ceramic resin is composed of the following raw materials by mass fraction: 5-15% water-based acrylic polymer, 5-20% silica sol solution, 23-40% siloxane, 2-15% alcohol, 10-15% deionized water, 1% metal oxide, and the sum of the mass fractions of the above components is 100%; the leveling agent is an organic silicon leveling agent or a fluorocarbon leveling agent; the defoamer is a water-based paint defoamer; and the dispersant is a water-based paint dispersant; The water-based nano-ceramic resin is prepared by the following steps: by mass fraction, 5-15% of water-based acrylic polymer, 5-20% of silica sol solution, 23-40% of siloxane, 2-15% of alcohols, 10-15% of deionized water, and 1% of metal oxide are stirred in a reactor at normal temperature and pressure for 20-60 minutes to react and form a water-based nano-ceramic resin.

2. A method for preparing the corrosion-resistant water-soluble zinc plating sealant according to claim 1, characterized in that: Step 1: Mix deionized water and ethanol evenly according to the mass fraction ratio; Step 2: Add water-based nano-ceramic resin, dispersant, defoamer and leveling agent in proportion; Step 3: Stir electrically for 10 minutes, let stand to defoam, and obtain a corrosion-resistant water-soluble zinc-plating sealer.

3. The method for preparing the corrosion-resistant water-soluble zinc plating sealant according to claim 2, characterized in that: The electric stirring speed is 1000-1500 rpm.

4. A method for using the corrosion-resistant water-soluble zinc plating sealant according to claim 1, characterized in that: After cleaning and drying the electro-galvanized or hot-dip galvanized parts, when the surface temperature reaches 20-50°C, immerse the parts in the sealant for 2-3 seconds, take them out, remove excess liquid on the surface, dry them with hot air at 60-90°C for 10-20 minutes, and complete the sealant operation after natural cooling.

5. The method for using the corrosion-resistant water-soluble galvanizing sealant according to claim 4, characterized in that: The method of removing excess liquid on the surface is centrifugal drying or blowing.

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