CN103360839A - Metal protective paint and application thereof, and hot-dip metal material - Google Patents

Abstract

The invention provides a protective metal coating, which is obtained by uniformly mixing a raw material mixture, and the raw material mixture contains water-soluble silicate, silicon oxide filler, accelerator, water-soluble film-forming resin, (CH ₃ CH ₂ O) ₃ Si(CH ₂ ) ₂ Si(OCH ₂ CH ₃ ) ₃ and water; the accelerator is an aqueous emulsion of polyethylene wax and/or an aqueous emulsion of oxidized polyethylene wax. The present invention also provides the use of the above-mentioned protective metal coating in the preparation of metal materials. The present invention also provides a hot-dip metal material, which comprises a hot-dip metal substrate and a coating attached to the hot-dip metal substrate, and the coating is a metal protective coating as described above cured product. The corrosion resistance, water resistance, heat resistance and fingerprint resistance of the protective film formed by the metal protective paint provided by the invention are all excellent.

Description

A kind of metal protection paint and its application and hot-dip metal material

technical field

The invention relates to the field of metal protection, in particular to a metal protection coating, the application of the metal protection coating and a hot-dip metal material.

Background technique

Hot-dip metal materials, including hot-dip galvanized metal materials and hot-dip galvanized metal materials, in order to prevent corrosion, a layer of metal protective paint will be coated on the surface of the hot-dip metal materials to form a protective film. Therefore, the performance of metal protective coatings is very important for the anti-corrosion of hot-dip metal materials.

For example, CN101608306A discloses a passivation solution, which also belongs to a metal protective coating, and is characterized in that the passivation solution is an aqueous solution containing a water-soluble molybdenum compound, boric acid, water-soluble organic matter and silica sol, wherein the water-soluble The organic compound is a mixture of alcohol and organic carboxylic acid.

However, experiments have proved that the corrosion resistance, water resistance, heat resistance and fingerprint resistance of the protective film formed by the metal protective coating are still poor.

Contents of the invention

The purpose of the present invention is to overcome the defects of poor corrosion resistance, water resistance, heat resistance and fingerprint resistance of the protective film formed by the existing metal protective coating, and to provide a protective film capable of forming corrosion resistance, water resistance and heat resistance. Protective coating for metals with a protective film with good anti-fingerprint and anti-fingerprint properties.

In order to achieve the above object, the present invention provides a protective metal coating, which is obtained by uniformly mixing a raw material mixture, the raw material mixture contains water-soluble silicate, silicon oxide filler, accelerator, water-soluble component Film resin, (CH ₃ CH ₂ O) ₃ Si(CH ₂ ) ₂ Si(OCH ₂ CH ₃ ) ₃ and water; the accelerator is an aqueous emulsion of polyethylene wax and/or an aqueous emulsion of oxidized polyethylene wax.

The present invention also provides the use of the above-mentioned protective metal coating in the preparation of metal materials.

The present invention also provides a hot-dip metal material, which comprises a hot-dip metal substrate and a coating attached to the hot-dip metal substrate, and the hot-dip metal substrate is a hot-dip galvanized metal substrate material and/or hot-dip galvalume metal substrate, characterized in that the coating is a cured product of the metal protective coating as described above.

Through the above technical solution, the protective film formed by the metal protective coating provided by the present invention has excellent corrosion resistance, water resistance, heat resistance and fingerprint resistance. Moreover, the protective film formed by the metal protective coating provided by the invention has particularly excellent lubricating properties.

Other features and advantages of the present invention will be described in detail in the following detailed description.

Detailed ways

Specific embodiments of the present invention will be described in detail below. It should be understood that the specific embodiments described here are only used to illustrate and explain the present invention, and are not intended to limit the present invention.

According to the protective metal coating provided by the present invention, wherein, the protective metal coating is obtained after uniformly mixing a raw material mixture, and the raw material mixture contains water-soluble silicate, silicon oxide filler, accelerator, water-soluble film-forming resin, ( CH ₃ CH ₂ O) ₃ Si(CH ₂ ) ₂ Si(OCH ₂ CH ₃ ) ₃ and water; the accelerator is an aqueous emulsion of polyethylene wax and/or an aqueous emulsion of oxidized polyethylene wax.

Among them, (CH ₃ CH ₂ O) ₃ Si(CH ₂ ) ₂ Si(OCH ₂ CH ₃ ) ₃ is called bis(1,2-triethoxysilyl)ethane, which can be used as a silane coupling agent, Various (CH ₃ CH ₂ O) ₃ Si(CH ₂ ) ₂ Si(OCH ₂ CH ₃ ) ₃ commercially available as silane coupling agents can be used in the present invention.

Wherein, the metal protective coating is obtained after the raw material mixture is uniformly mixed, and is a relatively stable and uniform liquid. Preferably, each component in the raw material mixture is mixed uniformly 1-180 days before the protective metal coating is used. Wherein, there is no special requirement on the mixing order of each component, and each component in the raw material mixture can be directly mixed simultaneously, in batches or in steps, as long as a uniform stable phase can be obtained, preferably by stirring to make the mixing more uniform .

According to the protective metal coating provided by the present invention, wherein, relative to 1 part by weight of the water-soluble silicate, the amount of (CH ₃ CH ₂ O) ₃ Si(CH ₂ ) ₂ Si(OCH ₂ CH ₃ ) ₃ can be It is 0.5-4.5 parts by weight, preferably 1.4-1.8 parts by weight.

Wherein, relative to 1 part by weight of the water-soluble silicate, the content of the accelerator may be 0.2-1.8 parts by weight, preferably 0.5-0.7 parts by weight.

Wherein, relative to 1 part by weight of the water-soluble silicate, the silica filler may be used in an amount of 0.25-2.2 parts by weight, preferably 0.6-0.85 parts by weight.

Wherein, relative to 1 part by weight of the water-soluble silicate, the amount of the water-soluble film-forming resin may be 0.8-6.8 parts by weight, preferably 2.1-2.7 parts by weight, in terms of solids. Here, the solid has the same meaning as the solid used to calculate or express the solid content, that is, the remaining component of the water-soluble film-forming resin after removing the solvent.

Wherein, relative to 1 part by weight of the water-soluble silicate, the amount of water used is 10-100 parts by weight, preferably 25-40 parts by weight. It should be noted that the amount of water used in the present invention refers to the amount of additionally added water, excluding the amount of water contained in the above-mentioned other components added in the form of solution or emulsion.

According to the protective metal coating provided by the present invention, the water-soluble silicate may be sodium silicate and/or potassium silicate.

According to the protective metal coating provided by the present invention, wherein the aqueous emulsion of polyethylene wax can be an aqueous emulsion obtained by emulsifying polyethylene wax according to a conventional method, the solid content of the aqueous emulsion of polyethylene wax can be 30- 60% by weight, preferably 40-50% by weight. It should be noted that when the aqueous emulsion of polyethylene wax is used to prepare the protective metal coating provided by the present invention, its dosage refers to the value obtained by multiplying the total weight of the aqueous emulsion by its solid content.

Wherein, the polyethylene wax in the aqueous emulsion of polyethylene wax may have a melting point of 90-130°C, preferably 100-120°C, more preferably 105-115°C.

According to the metal protective coating provided by the present invention, wherein, the aqueous emulsion of the oxidized polyethylene wax can be an aqueous emulsion obtained by emulsifying the oxidized polyethylene wax according to a conventional method, and the solid content of the aqueous emulsion of the oxidized polyethylene wax can be It is 30-60% by weight, preferably 40-50% by weight. It should be noted that when the aqueous emulsion of oxidized polyethylene wax is used to prepare the protective metal coating provided by the present invention, its dosage refers to the value obtained by multiplying the total weight of the aqueous emulsion by its solid content.

Wherein, the melting point of the oxidized polyethylene wax in the aqueous emulsion of oxidized polyethylene wax may be 80-120°C, preferably 90-115°C, more preferably 100-110°C.

It should be noted that, unless otherwise stated in the present invention, the melting point of polyethylene wax and oxidized polyethylene wax refers to the value determined according to GB/T 2539-2008 Determination of the Melting Point of Petroleum Wax-Cooling Curve Method.

Wherein, the acid value of the oxidized polyethylene wax in the aqueous emulsion of oxidized polyethylene wax may be 5-60 mgKOH/g, preferably 10-50 mgKOH/g. Wherein, described acid value is the numerical value that measures according to GB/T 264-83 petroleum product acid value determination method.

According to the protective metal coating provided by the present invention, wherein the silica filler has no special requirements, it can be various fillers mainly composed of silica, for example, the silica filler can be nano-silica powder and/or Silica sol; preferably, the silica filler is nano-silica powder, and the particle size of the nano-silica powder can be 10-90nm.

According to the metal protective coating provided by the present invention, wherein, the water-soluble film-forming resin can be various water-soluble and modified or unmodified resins that can be used for film formation, and the resin can be prepared in the form of suitable products form, such as at least one of water-soluble emulsion, water-soluble solution and water-soluble solid, the present invention has no special requirements, as long as it can be used for film formation, for example, the water-soluble film-forming resin can be water-soluble Polyester film-forming resin (that is, a water-soluble film-forming resin obtained by polymerizing polyol monomers and polyacid monomers, such as the polyester resin purchased from Guangzhou Libao Fine Chemical Co., Ltd., brand CB2200), water-soluble Styrene-acrylic film-forming resin (that is, a water-soluble film-forming resin obtained by polymerizing styrene monomers and acrylic acid (ester) monomers, such as benzene purchased from Guangzhou Chaolong Chemical Technology Co., Ltd., the brand is xy-108b Acrylic emulsion), water-soluble epoxy film-forming resin (that is, a water-soluble film-forming resin obtained by polymerization of monomers containing epoxy groups, such as epoxy resin purchased from Dongguan Heima Chemical Co., Ltd., brand BH620), Water-soluble polyurethane film-forming resin (that is, a water-soluble film-forming resin obtained by polymerizing polyvalent isocyanate monomers and polyhydric hydroxyl compound monomers, such as polyurethane resin purchased from Fujian Jinjiang Jianhua Company, brand 812), water-soluble silicone acrylic Film-forming resin (i.e., the water-soluble film-forming resin obtained by polymerization of organosilicon monomers and acrylic acid (ester) monomers, such as Qingdao Xingguo Paint Company TC-05 type silicon acrylic emulsion, solid content is 48% by weight), Water-soluble acrylic film-forming resin (that is, a water-soluble film-forming resin obtained by polymerization of acrylic acid (ester) monomers, such as the acrylic resin purchased from Guangzhou Oupeng Chemical Co., Ltd. with the brand name A-3418) and water-soluble fluorocarbon film-forming resin At least one of the resin (i.e., the water-soluble film-forming resin obtained by polymerization of fluorine-containing monomers, such as the water-based fluorocarbon emulsion purchased from Beijing Shouchuang Nano Technology Co., Ltd., the trade mark is SKFT-I); preferably, The water-soluble film-forming resin is water-soluble styrene-acrylic film-forming resin, water-soluble epoxy film-forming resin, water-soluble silicon-acrylic film-forming resin, water-soluble acrylic film-forming resin, water-soluble polyurethane film-forming resin and water-soluble polyester at least one of film-forming resins.

In addition to the above components, the protective metal coating of the present invention may also contain other various components that do not affect the properties of the protective metal coating, such as one or more of dyes, pigments, dispersants and defoamers. Based on the total weight of the protective metal coating, the content of other components is not more than 20% by weight, preferably not more than 10% by weight. The defoamer may be various defoamers known in the art, such as one or more of polyether defoamers, high-carbon alcohol defoamers and silicon defoamers. More specifically, the defoamer may be one or more of SD-401 series defoamers commercially available from Dongying Shida Innovation Technology Co., Ltd., for example. Preferably, based on the total amount of the metal protective coating, the content of the defoamer is 0.01-0.05% by weight.

The metal protection paint of the present invention can be used directly without dilution.

The present invention also provides the use of the above-mentioned protective metal coating in the preparation of metal materials. The above metal protective coatings can be used in the conventional manner in the art to prepare various metal materials.

According to the hot-dip metal material provided by the present invention, the hot-dip metal material comprises a hot-dip galvanized metal substrate and a coating attached to the hot-dip metal substrate, and the hot-dip metal substrate is a hot-dip galvanized metal substrate And/or hot-dip galvalume metal substrates, characterized in that the coating is a cured product of the metal protective coating as described above.

Wherein, the hot-dip galvanized metal substrate may be a metal substrate containing a zinc coating, and the content of zinc in the zinc coating may be 92.5-95.5% by weight. The zinc coating may also contain other conventional components, such as silicon.

Wherein, the hot-dip galvalume metal material may be a metal substrate containing zinc-aluminum coating, and in the zinc-aluminum coating, the content of zinc may be 41.5-43.5% by weight, and the content of aluminum may be 51.5-55.0% by weight. The zinc-aluminum coating may also contain other conventional components, such as silicon.

According to the hot-dip metal material provided by the present invention, wherein the thickness of the coating can be the conventional thickness of the anti-corrosion coating on the hot-dip metal substrate, in order to improve the performance of the coating, preferably, the The thickness of the coating is 0.05-2 microns, preferably 0.1-1 microns.

According to the hot-dip metal material provided by the present invention, wherein, the method for adhering the coating on the hot-dip metal substrate may include attaching the metal protective coating on the surface of the hot-dip metal substrate, and then drying, drying The temperature can be 60-120°C, preferably 90-110°C, and the time can be 0.5-3 seconds. The amount of the protective metal coating can be determined according to the thickness of the coating.

Wherein, the drying method may be one or more of hot air drying, induction heating and infrared radiation heating.

In the present invention, unless otherwise stated, the volumes of all liquids and solids refer to volumes at 20° C. and 1 standard atmospheric pressure.

The present invention will be further described in detail through examples below.

Example 1

The water-soluble silicate (sodium silicate, purchased from Baoding Runfeng Industrial Co., Ltd.) of 1 weight part, the accelerator (the aqueous emulsion of polyethylene wax and the aqueous emulsion of oxidized polyethylene wax by weight ratio 1 : Obtained after 1 mixing, the aqueous emulsion of polyethylene wax is purchased from Hongguang Plastic Raw Material Management Department of Dongguan City, and the solid content is 48% by weight, and the melting point of polyethylene wax is 110-115 ℃; The aqueous emulsion of oxidized polyethylene wax is purchased from Beijing Zhongguan Special Wax Co., Ltd., the solid content is 48% by weight, the melting point of oxidized polyethylene wax is 105-110°C, the acid value is 14-21mgKOH/g), 1.6 parts by weight of (CH ₃ CH ₂ O) ₃ Si (CH ₂ ) ₂ Si(OCH ₂ CH ₃ ) ₃ (purchased from Hubei Limeida Silicon Fluoride Technology Co., Ltd., brand LMD-26E), 0.72 parts by weight of silica filler (nano silica powder, purchased from GE company, RNS-E, average particle size 20nm), 2.4 parts by weight (in terms of solids) of water-soluble film-forming resin (water-soluble silicon-acrylic film-forming resin (Qingdao Xingguo Paint Company TC-05 type silicon-acrylic emulsion, solid content of 48% by weight)) and 28 parts by weight of water were mixed until uniform at a stirring speed of 1500 rpm to obtain the protective metal coating of this embodiment.

Comparative example 1

Metal protective coatings were prepared according to the method of Example 1, except that (CH ₃ CH ₂ O) was replaced with aminopropyltriethoxysilane (purchased from Hubei Limeida Silicon Fluoride Technology Co., Ltd., brand LMD-1100) ₃ Si(CH ₂ ) ₂ Si(OCH ₂ CH ₃ ) ₃ .

Comparative example 2

Metal protective coatings were prepared according to the method of Example 1, except that no accelerator was added.

Comparative example 3

The protective metal coating was prepared according to the method of Example 1, except that no water-soluble silicate was added.

Comparative example 4

The protective metal coating was prepared according to the method of Example 1, except that no silica filler was added.

Example 2

With 1 weight part of water-soluble silicate (potassium silicate, purchased from Baoding Runfeng Industrial Co., Ltd.), 0.5 weight part of accelerator (aqueous emulsion of oxidized polyethylene wax, purchased from Beijing Zhongguan Special Wax Co., Ltd., The solid content is 48% by weight, the melting point of oxidized polyethylene wax is 100-105°C, the acid value is 17-26mgKOH/g), 1.4 parts by weight of (CH ₃ CH ₂ O) ₃ Si(CH ₂ ) ₂ Si(OCH ₂ CH ₃ ) ₃ (purchased from Hubei Limeida Silicon Fluoride Technology Co., Ltd., brand LMD-26E), 0.6 parts by weight of silica filler (nano silica, purchased from GE Company of the United States, RNS-E, average particle size 20nm), 2.1 parts by weight (in solids) of water-soluble film-forming resin (water-soluble acrylic film-forming resin (acrylic resin purchased from Guangzhou Oupeng Chemical Industry's brand is A-3418)) and 25 parts by weight of water, in Mix until uniform at a stirring speed of 1500 rpm to obtain the metal protective coating of this embodiment.

Example 3

With 1 weight part of water-soluble silicate (sodium silicate, purchased from Baoding Runfeng Industrial Co., Ltd.), 0.7 weight part of accelerator (aqueous emulsion of polyethylene wax, purchased from Dongguan Hongguang Plastic Raw Materials Management Department, The solid content is 48% by weight, the melting point of polyethylene wax is 105-110°C), 1.8 parts by weight of (CH ₃ CH ₂ O) ₃ Si(CH ₂ ) ₂ Si(OCH ₂ CH ₃ ) ₃ (purchased from Hubei Li Meida Silicon Fluorine Technology Co., Ltd., brand name LMD-26E), 0.85 parts by weight of silica filler (30% by weight of silica sol, the usage amount is based on solids), 2.7 parts by weight (based on solids) of water-soluble film-forming resin (water-soluble polyurethane film-forming resin (purchased from Fujian Jinjiang Jianhua Company, polyurethane resin of brand 812)) and 40 parts by weight of water, mixed to uniform at a stirring speed of 1500 rpm to obtain the protective metal coating of the present embodiment .

Example 4

The water-soluble silicate (sodium silicate, purchased from Baoding Runfeng Industrial Co., Ltd.) of 1 weight part, the accelerator (the aqueous emulsion of polyethylene wax and the aqueous emulsion of oxidized polyethylene wax by weight ratio 1 : Obtained after 1 mixing, the aqueous emulsion of polyethylene wax is purchased from Hongguang Plastic Raw Material Management Department of Dongguan City, and the solid content is 48% by weight, and the melting point of polyethylene wax is 110-115 ℃; The aqueous emulsion of oxidized polyethylene wax is purchased from Beijing Zhongguan Special Wax Co., Ltd., the solid content is 48% by weight, the melting point of oxidized polyethylene wax is 105-110°C, the acid value is 14-21mgKOH/g), 0.6 parts by weight of (CH ₃ CH ₂ O) ₃ Si (CH ₂ ) ₂ Si(OCH ₂ CH ₃ ) ₃ (purchased from Hubei Limeida Silicon Fluoride Technology Co., Ltd., brand LMD-26E), 2.1 parts by weight of silica filler (nano silica powder, purchased from GE company, RNS-E, average particle size 20nm), 6.5 parts by weight (in terms of solids) of water-soluble film-forming resin (water-soluble silicon-acrylic film-forming resin (Qingdao Xingguo Paint Company TC-05 type silicon-acrylic emulsion, solid content of 48% by weight)) and 90 parts by weight of water were mixed until uniform at a stirring speed of 1500 rpm to obtain the protective metal coating of this embodiment.

Example 5

The water-soluble silicate (sodium silicate, purchased from Baoding Runfeng Industrial Co., Ltd.), 1.7 parts by weight of the accelerator (the aqueous emulsion of polyethylene wax and the aqueous emulsion of oxidized polyethylene wax by weight ratio 1 : Obtained after 1 mixing, the aqueous emulsion of polyethylene wax is purchased from Hongguang Plastic Raw Material Management Department of Dongguan City, and the solid content is 48% by weight, and the melting point of polyethylene wax is 110-115 ℃; The aqueous emulsion of oxidized polyethylene wax is purchased from Beijing Zhongguan Special Wax Co., Ltd., the solid content is 48% by weight, the melting point of oxidized polyethylene wax is 105-110°C, the acid value is 14-21mgKOH/g), 4.5 parts by weight of (CH ₃ CH ₂ O) ₃ Si (CH ₂ ) ₂ Si(OCH ₂ CH ₃ ) ₃ (purchased from Hubei Limeida Silicon Fluoride Technology Co., Ltd., brand LMD-26E), 0.3 parts by weight of silica filler (nano silica powder, purchased from GE Company, RNS-E, average particle size 20nm), 1.0 parts by weight (in terms of solids) of water-soluble film-forming resin (water-soluble silicon-acrylic film-forming resin (Qingdao Xingguo Paint Company TC-05 type silicon-acrylic emulsion, solid content of 48% by weight)) and 15 parts by weight of water were mixed until uniform at a stirring speed of 1500 rpm to obtain the protective metal coating of this embodiment.

Example 6

Metal protective coatings are prepared according to the method of Example 1, the difference is that the accelerator is an aqueous emulsion of polyethylene wax, which is purchased from Dongguan Hongguang Plastic Raw Materials Management Department, with a solid content of 48% by weight and a melting point of polyethylene wax It is 118-125°C.

Example 7

Metal protective coatings are prepared according to the method of Example 1, the difference is that the accelerator is an aqueous emulsion of oxidized polyethylene wax, purchased from Beijing Zhongguan Special Wax Co., Ltd., with a solid content of 48% by weight, and the amount of oxidized polyethylene wax The melting point is 80-95°C, and the acid value is 5-10mgKOH/g.

Example 8

The metal protective coating is prepared according to the method of Example 1, the difference is that a water-soluble styrene-acrylic film-forming resin (purchased from Guangzhou Chaolong Chemical Technology Co., Ltd., a styrene-acrylic emulsion of xy-108b) is used as a water-soluble film-forming resin resin.

Example 9

Metal protective coatings were prepared according to the method of Example 1, except that a water-soluble epoxy film-forming resin (purchased from Dongguan Heima Chemical Co., Ltd., water-based epoxy resin emulsion with a brand name of BH620) was used as the water-soluble film-forming resin.

Example 10

The metal protective coating is prepared according to the method of Example 1, the difference is that a water-soluble polyester film-forming resin (purchased from Jiangsu Yancheng Juke Chemical Co., Ltd., a water-based polyester with a brand name of PE-10030-P) is used as the water-soluble polyester film-forming resin. film resin.

Preparation Example 1

Get the metallic protective paint that embodiment 1-10 and comparative example 1-4 obtain and be coated with respectively on the galvanized steel plate (purchased from Panzhihua Steel and Vanadium Co., Ltd. of Panzhihua Iron and Steel Group, model DX54D, zinc-containing 95% by weight in the galvanized layer) The surface is dried with hot air at 90-110° C. for 2 seconds to obtain the treated galvanized steel sheet 1-14. Wherein, the coating amount is such that the thickness of the coatings on the galvanized steel sheets 1-14 is all 0.8 microns. The thickness of the coating is a value measured with an XRF (fluorescence spectrometer) measuring instrument.

Preparation Example 2

Get the metal protection paint that embodiment 1-10 and comparative example 1-4 obtain and apply on galvanized steel plate respectively (purchased from Panzhihua Steel and Vanadium Co., Ltd. of Pangang Group, model DX51D+AZ, zinc 42.5 in the galvanized layer % by weight, containing 52.3% by weight of aluminum), hot air drying at 90-110° C. for 2 seconds to obtain the treated galvalume steel sheet 1-14. Wherein, the coating amount is such that the thickness of the coatings on the galvanized steel sheets 1-14 is all 0.8 microns. The thickness of the coating is a value measured with an XRF (fluorescence spectrometer) measuring instrument.

Test Example 1

According to the requirements specified in GB/T 101251997, the neutral salt spray test was carried out to determine the corrosion resistance of galvanized steel sheet 1-14 and galvanized steel sheet 1-14. According to "salt spray test 96h, rust area <20%" is considered qualified.

The water resistance of galvanized steel sheets 1-14 and galvalume-coated steel sheets 1-14 was measured as follows.

On the surface of galvanized steel plate 1-14 and galvanized steel plate 1-14 placed horizontally, add about 2 ml of boiling water dropwise, after 24 hours of natural drying, stick the dripping place with 3M adhesive tape, and stick it on the adhesive tape. According to the number of spot counts on the adhesive tape per square centimeter, the water resistance of the film layer is judged. The more spots that are stuck, the worse the water resistance.

The heat resistance of the galvanized steel sheets 1-14 and the galvalume-coated steel sheets 1-14 was measured as follows.

Put the galvanized steel sheets 1-14 and the galvanized steel sheets 1-14 in a hot air furnace, bake them at 300°C for 20 minutes, then take them out to observe the changes in the surface morphology of the coatings, and use a colorimeter to test the samples before and after baking Surface ΔL (luminance variable), Δa (red-green variable), Δb (yellow-blue variable) values, and calculate ΔE (color difference) = (ΔL ² +Δa ² +Δb ² ) ^1/2 . The smaller the ΔE, the better the heat resistance of the coating.

The fingerprint resistance of the galvanized steel sheets 1-14 and the galvalume-coated steel sheets 1-14 was measured as follows.

The ΔL (luminance variable), Δa (red-green variable), and Δb (yellow-blue variable) values of galvanized steel sheets 1-14 and galvanized steel sheets 1-14 before and after coating with 0.5 g/m2 vaseline were tested by a colorimeter, and Calculate ΔE (color difference)=(ΔL ² +Δa ² +Δb ² ) ^1/2 , the smaller the ΔE, the better the anti-fingerprint performance of the coating.

On the M-2000 ring block type friction and wear tester, measure and test the dynamic friction coefficient of the coating of galvanized steel sheet 1-14 and galvanized steel sheet 1-14 according to its instruction manual.

The test results as mentioned above are shown in Table 1.

Table 1

According to the data in Table 1, it can be seen that the corrosion resistance, water resistance, heat resistance and fingerprint resistance of the protective film formed by the metal protective coating provided by the present invention are all very good. And, according to the data in Table 1, it can be seen that, preferably relative to 1 part by weight of the water-soluble silicate, the content of the accelerator is 0.5-0.7 parts by weight, (CH ₃ CH ₂ O) ₃ Si(CH ₂ ) ₂ Si(OCH ₂ CH ₃ ) ₃ is used in an amount of 1.4-1.8 parts by weight, the amount of the silica filler is 0.6-0.85 parts by weight, and the amount of the water-soluble film-forming resin is 2.1-2.7 parts by weight in terms of solids When the amount of water used is 25-40 parts by weight, the corrosion resistance, water resistance, heat resistance, fingerprint resistance and lubricity of the protective film formed by the metal protective coating can be further improved.

The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention. These simple modifications All belong to the protection scope of the present invention.

In addition, it should be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable way if there is no contradiction. The combination method will not be described separately.

In addition, various combinations of different embodiments of the present invention can also be combined arbitrarily, as long as they do not violate the idea of the present invention, they should also be regarded as the disclosed content of the present invention.

Claims (10)

1. A protective coating for metal, which is obtained after being uniformly mixed by a mixture of raw materials, said mixture of raw materials contains water-soluble silicate, silicon oxide filler, promotor, water-soluble film-forming resin, (CH ₃ CH ₂ O) ₃ Si(CH ₂ ) ₂ Si(OCH ₂ CH ₃ ) ₃ and water; the accelerator is an aqueous emulsion of polyethylene wax and/or an aqueous emulsion of oxidized polyethylene wax. 2. The protective metal coating according to claim 1, wherein, relative to 1 part by weight of the water-soluble silicate, (CH ₃ CH ₂ O) ₃ Si(CH ₂ ) ₂ Si(OCH ₂ CH ₃ ) ₃ is used in an amount of 0.5-4.5 parts by weight, the amount of the silica filler is 0.25-2.2 parts by weight, the content of the accelerator is 0.2-1.8 parts by weight, in terms of solids, the amount of the water-soluble film-forming resin The amount of water is 0.8-6.8 parts by weight, and the amount of water is 10-100 parts by weight. 3. The protective metal coating according to claim 2, wherein, relative to 1 part by weight of the water-soluble silicate, the content of the accelerator is 0.5-0.7 parts by weight, (CH ₃ CH ₂ O) ₃ The amount of Si(CH ₂ ) ₂ Si(OCH ₂ CH ₃ ) ₃ is 1.4-1.8 parts by weight, the amount of the silica filler is 0.6-0.85 parts by weight, and the amount of the water-soluble film-forming resin is The consumption of water is 2.1-2.7 parts by weight, and the consumption of water is 25-40 parts by weight. 4. The protective metal coating according to any one of claims 1-3, wherein the solid content of the aqueous emulsion of polyethylene wax is 30-60% by weight; The melting point of ethylene wax is 100-120°C; the solid content of the aqueous emulsion of oxidized polyethylene wax is 30-60% by weight; the melting point of the oxidized polyethylene wax in the aqueous emulsion of oxidized polyethylene wax is 90-115 °C, the acid value is 10-50mgKOH/g. 5. The protective metal coating according to any one of claims 1-3, wherein the silica filler is nano silica powder and/or silica sol. 6. The protective metal coating according to any one of claims 1-3, wherein the water-soluble film-forming resin is water-soluble polyester film-forming resin, water-soluble styrene-acrylic film-forming resin, water-soluble epoxy film-forming resin At least one of film resin, water-soluble polyurethane film-forming resin, water-soluble silicone acrylic film-forming resin, water-soluble acrylic film-forming resin and water-soluble fluorocarbon film-forming resin. 7. The protective metal coating according to any one of claims 1-3, wherein the raw material mixture further contains one or more of a dispersant, a defoamer and a stabilizer. 8. Use of the protective metal coating according to any one of claims 1-7 in the preparation of metal materials. 9. A hot-dip metal material, the hot-dip metal material comprises a hot-dip metal substrate and a coating attached to the hot-dip metal substrate, the hot-dip metal substrate is a hot-dip galvanized metal substrate and/ Or a hot-dip galvalume metal substrate, characterized in that the coating is a cured product of the protective metal coating according to any one of claims 1-7. 10. The hot-dip metal material according to claim 9, wherein the thickness of the coating is 0.1-1 micron.