1. A water-based seal primer for a thermal spraying zinc substrate is prepared from a component A and a component B, and is characterized in that the preparation raw material of the component A comprises the following components in parts by weight:

the component B is prepared from the following components in parts by weight:

2. the water-based seal primer for the thermal zinc spraying substrate according to claim 1, wherein the mass ratio of the component A to the component B is 3-6: 1.

3. the water-based seal primer for the hot spray zinc substrate according to claim 2, wherein the preparation raw materials of the component A further comprise 0.2-4 parts of an organic silicon defoamer, 0.1-2 parts of a mildew preventive and 0.1-2 parts of a polyurethane thickener.

4. A water-borne shop primer for thermal zinc spraying substrates according to claim 1, characterized in that the fumed silica is R974.

5. The waterborne shop primer for thermal zinc spraying substrate according to claim 4, wherein the flash rust inhibitor is one or a combination of sodium nitrite and benzotriazole.

6. The aqueous basecoat sealer for a thermal zinc spray substrate of claim 5 wherein said epoxy emulsion is STW 602.

7. The waterborne seal primer for the thermal spraying of zinc substrate according to the claim 1 to 6, wherein the curing agent is a polyether amine curing agent.

8. The water-based primer sealer according to any one of claims 1 to 7, wherein the preparation method comprises the steps of:

(1) adding fumed silica, a dispersing agent, a wetting agent, an organic silicon defoaming agent and a mildew preventive into deionized water respectively according to a proportion, and stirring for 3-10 min at a rotating speed of 500-800 r/min to obtain a mixture 1;

(2) respectively adding the filler, the aluminum tripolyphosphate and the zinc phosphate into the mixture 1 in proportion under the stirring condition, stirring for 5-20 min at the rotating speed of 500-800 r/min, and then grinding until the fineness is not more than 40 mu m to obtain a mixture 2;

(3) respectively adding the epoxy emulsion, the base material wetting agent, the organic silicon defoamer, the silane coupling agent, the black paste and the anti-flash rust agent into the mixture 2 in proportion, and stirring for 5-20 min to obtain a mixture 3;

(4) adding a thickening agent and deionized water into the mixture 3, and adjusting the viscosity and the solid part of a system to obtain a component A;

(5) under the condition of stirring, respectively adding a curing agent and propylene glycol monomethyl ether into deionized water according to a certain proportion, and uniformly stirring at a low speed to obtain a component B;

(6) and mixing the component A and the component B in proportion, and uniformly stirring to obtain the water-based seal primer.

9. Use of the aqueous basecoat sealer of claim 8 in thermal zinc spray substrate spraying.

10. Use according to claim 9, characterized in that a water-borne base sealer is used in combination with a basecoat and a topcoat; wherein the thickness of the water-based seal primer is 30-40 μm, the thickness of the intermediate paint is 40-50 μm, and the thickness of the finish paint is 40-50 μm.

Background

At present, for corrosion prevention of a steel structure, hot spraying zinc on the surface of the steel structure is often carried out, the principle of the hot spraying zinc is summarized that firstly, high-pressure air and a pipeline are utilized to blow sand grains to the surface of a workpiece to remove rust and oxide skin on the surface of the metal, meanwhile, surface hemp is increased to increase adsorption force of a hot spraying layer, and then, zinc is atomized and sprayed to the surface of the metal at a high speed by utilizing oxygen, acetylene or an electric heat source (a large workpiece is electrically heated, and a medium-small workpiece is heated by adopting oxygen and acetylene) through compressed air and a special tool (a spray gun).

After the hot zinc spraying process, the overall performance of the base material can be improved by spraying the primer, but in the prior art, the water-based seal primer is mostly oil-based paint, the VOC content is high and is usually more than 500g/L, and the great environmental pollution is easily caused; meanwhile, the temperature of the base material after hot spraying zinc is up to more than 400 ℃, a chemical reaction can also occur on a hot spraying zinc coating of a plurality of coating water-based paints on the market to generate hydrogen to cause foaming, and the problem that the salt spray resistance is not up to the standard due to insufficient protection performance of the coating water-based paint also exists. Chinese patent No. CN110862750A discloses an aqueous alternative thermal spray zinc coating, which uses a specific passivation treatment technology to inhibit the hydrogen evolution reaction of zinc powder and water, and uses water as a dispersion medium to greatly reduce the VOC content, reduce environmental pollution, make the coating flame-retardant, and be safer in production, transportation, storage and transportation, and has the advantage of good rust resistance; however, the main component of the coating is zinc, and zinc is mixed with a water-based epoxy modified acrylic resin, a water-based passivating agent and the like to improve the corrosion resistance of the material, and various indexes such as salt spray resistance, acid-base resistance and the like are not focused. Therefore, it is necessary to develop a primer sealer suitable for use with a thermal zinc spray substrate.

Disclosure of Invention

In view of the defects in the prior art, one of the objects of the present invention is to provide a water-based sealer for a thermal spray zinc substrate, wherein the water-based sealer is a water-based paint, and has the advantages of low VOC content, environmental friendliness and good fineness.

The invention also aims to provide a preparation method of the water-based seal primer, which has simple process and is easy to control.

It is another object of the present invention to provide the use of the above-mentioned water-based primer sealer for a thermal zinc-sprayed substrate, which has excellent properties of acid and alkali resistance, water resistance, salt spray resistance and aging resistance.

In order to achieve the purpose, the invention adopts the following technical scheme:

a water-based seal coat for a thermal spray zinc substrate is prepared from a component A and a component B;

the preparation raw materials of the component A comprise the following components in parts by weight:

the component B is prepared from the following components in parts by weight:

in a preferred embodiment of the invention, the mass ratio of the component A to the component B is 3-6: 1.

in a preferred embodiment of the invention, the preparation raw materials of the component A further comprise 0.2-4 parts of an organic silicon defoaming agent, 0.1-2 parts of a mildew preventive and 0.1-2 parts of a polyurethane thickener.

In a preferred embodiment of the invention, the fumed silica is R974.

In a preferred embodiment of the invention, the flash rust inhibitor is one or a combination of sodium nitrite and benzotriazole. In a more preferred embodiment of the present invention, the flash rust inhibitor is a mixture of sodium nitrite and benzotriazole.

In a preferred embodiment of the present invention, the epoxy emulsion is STW 602.

In a preferred embodiment of the present invention, the curing agent is a polyetheramine curing agent.

The invention also claims a preparation method of the water-based seal primer, which comprises the following steps:

(1) adding fumed silica, a dispersing agent, a wetting agent, an organic silicon defoaming agent and a mildew preventive into deionized water respectively according to a proportion, and stirring for 3-10 min at a rotating speed of 500-800 r/min to obtain a mixture 1;

(2) respectively adding the filler, the aluminum tripolyphosphate and the zinc phosphate into the mixture 1 in proportion under the stirring condition, stirring for 5-20 min at the rotating speed of 500-800 r/min, and then grinding until the fineness is not more than 40 mu m to obtain a mixture 2;

(3) respectively adding the epoxy emulsion, the base material wetting agent, the organic silicon defoamer, the silane coupling agent, the black paste and the anti-flash rust agent into the mixture 2 in proportion, and stirring for 5-20 min to obtain a mixture 3;

(4) adding a thickening agent and deionized water into the mixture 3, and adjusting the viscosity and the solid part of a system to obtain a component A;

(5) under the condition of stirring, respectively adding a curing agent and propylene glycol monomethyl ether into deionized water according to a certain proportion, and uniformly stirring at a low speed to obtain a component B;

(6) and mixing the component A and the component B in proportion, and uniformly stirring to obtain the water-based seal primer.

The invention also claims the application of the water-based seal coat prepared by the method in the spraying of the thermal spraying zinc substrate.

Preferably, in the application, the water-based seal primer is matched with the intermediate paint and the finish paint for use, wherein the thickness of the water-based seal primer is 30-40 μm, the thickness of the intermediate paint is 40-50 μm, and the thickness of the finish paint is 40-50 μm.

Compared with the prior art, the invention has the following beneficial effects:

(1) the invention provides the water-based seal primer suitable for the hot zinc spraying occasion for the first time, the seal primer is water-based but not oily, the VOC content is less than 80g/L, and the seal primer is more environment-friendly.

(2) The invention adopts the water-based epoxy emulsion and the polyamine curing agent as the film forming main body, and reasonably adds various substances such as the flash rust inhibitor, the metal passivation auxiliary agent, the silane coupling agent and the like, so that the prepared water-based seal primer has excellent performance, uniform appearance, good fineness and moderate viscosity. The flash rust inhibitor has the function of preventing the instantaneous oxidation of zinc and iron, the main components are sodium nitrite and benzotriazole, the sodium nitrite can generate an oxidation film with metal to inhibit the metal, and the benzotriazole is usually used for inhibiting the corrosion of copper alloy. The metal passivation auxiliary agent is aluminum tripolyphosphate and zinc phosphate, and can effectively inhibit the reaction of zinc metal and water. The use of the silane coupling agent further improves the water resistance of the coating film and the salt spray resistance of the whole coating.

(3) The preparation method of the water-based seal primer provided by the invention has simple process and easy operation, and is beneficial to realizing industrial large-scale production.

(4) The water-based seal primer, the intermediate paint and the top coat provided by the invention are used for construction of a hot-spraying zinc base material, and have the advantages of thin film, high hardness, salt and alkali resistance, water resistance, good salt spray resistance, good adhesive force, good impact resistance, excellent aging resistance and very excellent overall performance. The intermediate paint can increase the thickness of the film layer and further improve the corrosion resistance; the use of the finish paint can improve the appearance, prevent sunlight and ultraviolet rays and isolate the permeation of oxygen and water. The sealing primer provided by the invention is matched with the intermediate paint and the polyurethane finish paint to achieve the same performance of an oil coating system when being used as oil to change water on a coating line of a certain refrigeration plant, and the production efficiency index is achieved through the water-based coating modification of a production line, so that the sealing primer has a very wide application prospect.

Drawings

FIG. 1 shows the results of the salt spray resistance test (800 hours of treatment with 5% NaCl). As can be seen from the figure, the processed plate has no bubbling and rustiness, and the single-side corrosion width at the scratch is less than or equal to 2 mm.

FIG. 2 shows the results of the acid resistance test (3% H)₂SO₄Treatment for 120 hours). As can be seen, the treated sheet did not blister or wrinkle.

FIG. 3 shows the results of alkali resistance test (120 hours of 3% NaOH treatment). As can be seen, the treated sheet did not blister or wrinkle.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clearly illustrated, the present invention will be further explained in detail with reference to the accompanying drawings.

It should be noted that the raw materials used in the present invention are purchased from the outside unless otherwise specified. Wherein, fumed silica is R974 of EVONIK, aluminum tripolyphosphate and zinc phosphate are purchased from Guangxi New Crystal science and technology Limited, filler is purchased from Jiangxi Guangxi Guanghi chemical industry Limited, polyurethane thickener is purchased from Wanhua chemical, and epoxy emulsion is STW602 of Shanghai Huayi Fine chemical industry Limited.

Example 1

A water-based seal coat for a thermal spray zinc substrate is prepared from a component A and a component B in a mass ratio of 5: 1.

Wherein the component A is prepared from the following components:

wherein the component B is prepared from the following components:

in this example, the preparation method of the water-based seal coat is as follows:

(1) adding fumed silica, a dispersing agent, a wetting agent, an organic silicon defoaming agent and a mildew preventive into deionized water respectively according to a proportion, and stirring for 5min at a rotation speed of 550r/min to obtain a mixture 1;

(2) respectively adding the filler, the aluminum tripolyphosphate and the zinc phosphate into the mixture 1 in proportion under the stirring condition, stirring for 15min at the rotating speed of 500r/min, and then grinding until the fineness is not more than 40 microns to obtain a mixture 2;

(3) respectively adding the epoxy emulsion, the substrate wetting agent, the organic silicon defoamer, the silane coupling agent, the black paste, the benzotriazole and the sodium nitrite into the mixture 2 according to the proportion, and stirring for 15min to obtain a mixture 3;

(4) adding a thickening agent and deionized water into the mixture 3, and adjusting the viscosity and the solid part of a system to obtain a component A;

(5) under the stirring condition, respectively adding the polyether amine curing agent and propylene glycol methyl ether into deionized water according to a certain proportion, and uniformly stirring at a low speed to obtain a component B;

(6) and mixing the component A and the component B in proportion, and uniformly stirring to obtain the water-based seal primer.

Example 2

A water-based seal coat for a thermal spray zinc substrate is prepared from a component A and a component B in a mass ratio of 3.5: 1.

Wherein the component A is prepared from the following components:

wherein the component B is prepared from the following components:

in this example, the preparation method of the water-based seal coat is as follows:

(1) adding fumed silica, a dispersing agent, a wetting agent, an organic silicon defoaming agent and a mildew preventive into deionized water respectively according to a proportion, and stirring for 8min at a rotating speed of 570r/min to obtain a mixture 1;

(2) respectively adding the filler, the aluminum tripolyphosphate and the zinc phosphate into the mixture 1 in proportion under the stirring condition, stirring for 10min at the rotating speed of 600r/min, and then grinding until the fineness is not more than 40 micrometers to obtain a mixture 2;

(3) respectively adding the epoxy emulsion, the substrate wetting agent, the organic silicon defoamer, the silane coupling agent, the black paste, the benzotriazole and the sodium nitrite into the mixture 2 according to the proportion, and stirring for 10min to obtain a mixture 3;

(4) adding a thickening agent and deionized water into the mixture 3, and adjusting the viscosity and the solid part of a system to obtain a component A;

(5) under the stirring condition, respectively adding the polyether amine curing agent and propylene glycol methyl ether into deionized water according to a certain proportion, and uniformly stirring at a low speed to obtain a component B;

(6) and mixing the component A and the component B in proportion, and uniformly stirring to obtain the water-based seal primer.

Example 3

A water-based seal coat for a thermal spray zinc substrate is prepared from a component A and a component B in a mass ratio of 4: 1.

Wherein the component A is prepared from the following components:

wherein the component B is prepared from the following components:

in this example, the preparation method of the water-based seal coat is as follows:

(1) adding fumed silica, a dispersing agent, a wetting agent, an organic silicon defoaming agent and a mildew preventive into deionized water respectively according to a proportion, and stirring for 10min at a rotating speed of 600r/min to obtain a mixture 1;

(2) respectively adding the filler, the aluminum tripolyphosphate and the zinc phosphate into the mixture 1 in proportion under the stirring condition, stirring for 8min at the rotating speed of 700r/min, and then grinding until the fineness is not more than 40 micrometers to obtain a mixture 2;

(3) respectively adding the epoxy emulsion, the substrate wetting agent, the organic silicon defoamer, the silane coupling agent, the black paste, the benzotriazole and the sodium nitrite into the mixture 2 according to the proportion, and stirring for 8min to obtain a mixture 3;

(4) adding a thickening agent and deionized water into the mixture 3, and adjusting the viscosity and the solid part of a system to obtain a component A;

(5) under the stirring condition, respectively adding the polyether amine curing agent and propylene glycol methyl ether into deionized water according to a certain proportion, and uniformly stirring at a low speed to obtain a component B;

(6) and mixing the component A and the component B in proportion, and uniformly stirring to obtain the water-based seal primer.

Example 4

The performance of the water-based seal primer prepared in examples 1 to 3 was tested, and the test results are shown in table 1 below.

TABLE 1 Performance test results for waterborne seal primers

As can be seen from Table 1, the waterborne seal primer prepared by the method meets various rational indexes such as VOC content, appearance, viscosity, fineness and the like of the waterborne seal primer, and is excellent in performance, environment-friendly and friendly.

Example 5

The water-based seal coat prepared in example 1 was used to thermally spray paint a substrate, and the plate making procedure was as follows: material (ground, containing hot spray zinc) → 400 mesh sanding → spray seal primer → spray waterborne epoxy intermediate coat → spray acrylic finish/polyurethane finish.

Wherein the thickness of the water-based seal primer is 35 μm, the thickness of the water-based epoxy intermediate paint is 45 μm, and the thickness of the acrylic finish/polyurethane finish is 45 μm.

The performance parameters of the water-based seal coat prepared in the invention in plate making are shown in Table 2. Table 3 shows the results of the performance tests of the prepared sheet materials.

Table 2 performance test results of water-based sealer in panel making

As can be seen from table 2, the water based sealer primer can meet the panel making requirements.

TABLE 3 relevant Performance test results for the sheets

As can be seen from Table 3 and FIGS. 1 to 3, the water-based seal primer, the intermediate paint and the top coat in the application are used in combination, and the prepared plate has excellent acid and alkali resistance, water resistance, aging resistance, salt spray resistance and the like.

Meanwhile, the water-based seal primer prepared in the embodiment 1 is used for a coating line of a certain refrigerator factory to change oil into water, the seal primer provided by the invention, together with the intermediate paint and the polyurethane finish paint, achieves the same performance of an oil coating system, achieves the production efficiency index through water-based coating transformation of a production line, and has a very wide application prospect.

The above embodiments are merely illustrative of the technical ideas and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and implement the present invention, and not to limit the protection scope of the present invention. All equivalent changes and modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.