阅读说明：本技术 一种耐热防锈氧化铝涂料及其制备方法 (Heat-resistant antirust aluminum oxide coating and preparation method thereof ) 是由 李应龙 郑兴华 郁立新 朱敏凡 张鑫 于 2021-09-22 设计创作，主要内容包括：本发明公开了一种耐热防锈氧化铝涂料及其制备方法,所述涂料由聚乙烯醇缩丁醛(PVB)、丙烯酸树脂、超细α-氧化铝、消泡剂、流平剂、分散剂、体质颜料、着色颜料及溶剂组成；本发明使用吸热基团少的高分子聚合物PVB和丙烯酸树脂作为主要成膜物质,提高耐热效果,在具有二者共同优异特性的同时提高了PVB的成膜硬度以及附着力,改善了丙烯酸树脂均匀性不佳的问题；此外,加入分散性好、性质稳定的超细α-氧化铝,进一步提高了涂料的耐热、耐腐蚀以及强度等性能,通过各组分之间的协同作用,使得本发明涂料具有优异的耐热、防锈、吸附性好等优异性能,在金属防护以及外墙装饰等方面具有良好的应用前景。(The invention discloses a heat-resistant antirust alumina coating and a preparation method thereof, wherein the coating consists of polyvinyl butyral (PVB), acrylic resin, superfine alpha-alumina, a defoaming agent, a leveling agent, a dispersing agent, an extender pigment, a coloring pigment and a solvent; according to the invention, the high molecular polymer PVB with few heat-absorbing groups and the acrylic resin are used as main film forming substances, so that the heat-resistant effect is improved, the excellent characteristics of the PVB and the acrylic resin are achieved, the film forming hardness and the adhesive force of the PVB are improved, and the problem of poor uniformity of the acrylic resin is solved; in addition, the superfine alpha-alumina with good dispersibility and stable property is added, so that the heat resistance, corrosion resistance, strength and other properties of the coating are further improved, and the coating has excellent heat resistance, rust resistance, good adsorbability and other excellent properties through the synergistic effect of the components, and has good application prospects in the aspects of metal protection, exterior wall decoration and the like.)

1. The heat-resistant antirust aluminum oxide coating is characterized by comprising the following components in parts by weight: 10-25 parts of polyvinyl butyral, 5-20 parts of acrylic resin, 10-20 parts of alpha-alumina, 0.005-0.01 part of defoaming agent, 1-2 parts of flatting agent, 0.05-0.1 part of dispersing agent, 7-18 parts of extender pigment and 50-70 parts of solvent; the extender pigment comprises mica powder, calcium carbonate, talcum powder and kaolin.

2. The heat-resistant antirust alumina coating as claimed in claim 1, wherein the particle size of the α -alumina is 10 to 100 nm.

3. A heat-resistant antirust alumina coating as claimed in claim 1, wherein said coating further contains 5 to 15 parts by weight of a coloring pigment.

4. The heat-resistant antirust alumina coating according to claim 1, wherein the solvent is a mixed reagent of ethanol and butanol; the volume ratio of the ethanol to the butanol is 0.5-3: 1.

5. The preparation method of the heat-resistant antirust aluminum oxide coating as claimed in any one of claims 1 to 4, characterized by comprising the following steps:

(1) heating the aluminum oxide;

(2) adding acrylic resin into a solvent, stirring for dissolving, adding polyvinyl butyral, and continuously stirring to obtain a mixture;

(3) and (2) adding the alumina, the mica powder, the calcium carbonate, the talcum powder, the kaolin and the titanium dioxide which are treated in the step (1) into the mixture, stirring at a first stage, adding a defoaming agent, a flatting agent and a dispersing agent discontinuously in the stirring process, and stirring at a second stage after the addition is finished to obtain the uniformly mixed coating.

6. The method for preparing the heat-resistant antirust aluminum oxide coating according to claim 5, wherein the temperature of the heating treatment in the step (1) is 1200-1600 ℃.

7. The method for preparing the heat-resistant antirust aluminum oxide coating according to claim 5, wherein in the step (1), the heating treatment time is 2-3 h.

8. The preparation method of the heat-resistant antirust aluminum oxide coating as claimed in claim 5, wherein in the step (2), the rotation speed of stirring and dissolving is 200-300 r/min, and the stirring time is 15-20 min; the rotating speed of the continuous stirring is 600-1000 r/min, and the stirring time is 1-1.5 h.

9. The preparation method of the heat-resistant antirust aluminum oxide coating as claimed in claim 5, wherein in the step (3), the rotation speed of the first-stage stirring is 200-400 r/min, and the stirring time is 10-20 min; the rotating speed of the second-stage stirring is 600-1000 r/min, and the stirring time is 2-3 h.

10. The use of a heat-resistant rust-proof aluminum oxide coating as claimed in any one of claims 1 to 4 for metal protection and exterior wall decoration.

Technical Field

The invention relates to the technical field of coatings, in particular to a heat-resistant antirust aluminum oxide coating and a preparation method thereof.

Background

The coating is a liquid or solid material which can form a film to protect, decorate or perform other special functions when being coated on the surface of an object under certain conditions, generally comprises a film-forming substance, pigment, solvent and additive, and mainly plays roles of protecting, decorating, concealing defects and other special functions of a product and improving the value of the product, for example, the coating is used as a metal surface protective coating to prevent metal from being oxidized or corroded, or is used as an outer wall coating to perform waterproof decoration and the like.

The existing coatings on the market have the problems of poor strength, hardness, toughness, corrosion resistance, ageing resistance, heat resistance, poor scratch resistance under high-strength operation and the like, for example, the traditional nitrocellulose coating has poor solvent resistance, heat resistance and corrosion resistance, the viscosity of the nitrocellulose coating is greatly changed under the influence of temperature, and the nitrocellulose coating is difficult to coat at low temperature; in addition, the polyurethane resin coating is a two-liquid type coating formed by taking carbamate as a main agent and an isohydric acid salt, and needs to be blended in proportion before use, the blended coating is difficult to store, the coating has poor adhesive force and certain toxicity, the problems of air exhaust and the like need to be noticed during use, and in addition, the pinhole phenomenon is easy to occur during high-temperature coating or thick coating; the coating is difficult to be used for protecting metal or wall bodies which are exposed to moisture, high temperature and the presence of factors such as corrosion for a long time.

Disclosure of Invention

In order to solve the problems, the invention provides a heat-resistant, rust-proof and scratch-resistant aluminum oxide coating and a preparation method thereof, polyvinyl butyral (PVB) and acrylic resin are used as film forming substances, the advantages of two materials are achieved, the defect of a single component is overcome, the film forming hardness of a paint film is increased, the adhesive force is increased, the paint film is not easy to dry and crack, and the paint film has the characteristics of better water resistance, corrosion resistance, cold resistance, scratch resistance and the like.

The invention provides the following technical scheme:

the invention provides a heat-resistant antirust alumina coating, which comprises the following components in parts by weight: 10-25 parts of polyvinyl butyral, 5-20 parts of acrylic resin, 10-20 parts of alpha-alumina, 0.005-0.01 part of defoaming agent, 1-2 parts of flatting agent, 0.05-0.1 part of dispersing agent, 7-18 parts of extender pigment and 50-70 parts of solvent; the extender pigment comprises mica powder, calcium carbonate, talcum powder and kaolin.

Further, the coating also comprises 5-15 parts by weight of a coloring pigment.

Further, the 7-18 parts of extender pigment comprises 1-3 parts of mica powder, 2-5 parts of calcium carbonate, 1-5 parts of talcum powder and 3-5 parts of kaolin.

The extender pigment has good weather resistance and wear resistance, small density and good suspension force, can prevent pigment with larger density from sinking in the coating, can increase the thickness of a paint film, enhances the hardness and wear resistance of the paint film, and has certain improvement effect on the smoothness and aging degree of the paint film.

Further, the particle size of the alpha-alumina is 10-100 nm.

The alpha-alumina is the most stable phase in all the alumina, has the characteristics of uniform particle size distribution, high purity, good dispersibility, corrosion resistance, rust resistance, insulation, high temperature resistance, aging resistance, wear resistance and the like, can be used as a filler in the coating, can form a very fine, uniform and hard net structure on the surface of a paint film, protects the lower polymer paint layer from being damaged, greatly improves the scratch resistance of the coating, and enhances the thermal conductivity, corrosion resistance, high temperature resistance, stability and the like of the coating.

Further, the defoaming agent is preferably silicone oil.

Further, the leveling agent is preferably an acrylate-based leveling agent, such as MONENG-1153.

Further, the dispersant is triethylhexyl phosphoric acid and/or polyacrylamide.

Further, the solvent is a mixed solvent of ethanol and butanol; the volume ratio of the ethanol to the butanol is 0.5-3: 1.

The defoaming agent is added to reduce the surface tension of the liquid phase and prevent the formation of foam, so that the surface of the paint film has higher flatness and density, and the generation of pinholes caused by the generation and the breakage of bubbles is avoided, and the attractiveness and the performance of the paint film are not influenced.

Because the acrylic resin is easy to have the problems of uneven film formation and easy cracking, the adhesive force and the smoothness of the coating on a substrate are further improved by adopting the acrylic ester leveling agent.

The addition of triethylhexyl phosphoric acid in the coating can enhance the mixing effect of various substances in the coating, and the addition of polyacrylamide can prevent the sedimentation or heavy flowing of granular substances such as pigments and the like.

The film forming form of a dry and hard paint film is obtained through solvent evaporation in the paint, the selection of the solvent is extremely important, if the solvent is volatilized too fast, the concentration is increased rapidly, the paint on the surface loses fluidity due to too high adhesion, so that the paint film is uneven, if the solvent is volatilized too slowly, the heavy flow phenomenon is easy to occur, the interior is difficult to dry out, cracks are easy to occur in secondary coating, and the like. The alcohol solvent of the good solvent of the film forming substance is adopted, and the high-boiling-point butanol and the low-boiling-point ethanol are used for adjusting the drying rate of the coating, so that the coating is formed into a film at a proper drying rate, the performance of the paint film is not influenced, and the preservation of the paint is facilitated; in addition, the used ethanol and butanol belong to a third class of solvents, and the harm to human bodies and the environment is small.

The second aspect of the invention provides a preparation method of the heat-resistant antirust alumina coating, which comprises the following steps:

(1) heating the fully ground alumina;

(2) adding acrylic resin into a solvent, stirring for dissolving, adding polyvinyl butyral, and continuously stirring to obtain a mixture;

(3) and (2) adding the alumina, mica powder, calcium carbonate, talcum powder, kaolin and titanium dioxide treated in the step (1) into the mixture, stirring at the first stage, adding a defoaming agent, a flatting agent and a dispersing agent discontinuously in the stirring process, stirring at the second stage after the addition is finished, obtaining a uniformly mixed coating, and packaging for later use.

Further, in the step (1), the temperature of the heating treatment is 1200-1600 ℃.

Further, in the step (1), the time of the heat treatment is 2-3 h.

Further, in the step (2), the rotation speed of stirring and dissolving is 200-300 r/min, and the stirring time is 15-20 min; the rotating speed of the continuous stirring is 600-1000 r/min, and the stirring time is 1-1.5 h.

Further, in the step (3), the rotating speed of the first-stage stirring is 200-400 r/min, and the stirring time is 10-20 min; the rotating speed of the second-stage stirring is 600-1000 r/min, and the stirring time is 2-3 h.

Low-speed mixing is adopted in the early stage to prevent PVB from agglomerating due to too high early-stage rotating speed; the later stage improves the rotational speed and makes the homodisperse that packs can be better.

In the step (3), the defoaming agent, the leveling agent and the dispersing agent are added discontinuously in the stirring process, so that various powder materials and the auxiliary agent can be well and uniformly dispersed in the coating.

The third aspect of the invention provides the application of the heat-resistant antirust aluminum oxide coating in the first aspect in metal protection and exterior wall decoration.

Further, the heat-resistant antirust alumina coating is prepared by the preparation method of the second aspect.

Compared with the prior art, the invention has the beneficial effects that: according to the invention, through improvement on the formula and preparation process of the coating, PVB and acrylic resin containing few heat-absorbing groups are used as film-forming substances together, so that the heat resistance of a paint film is improved, the adhesion of the coating to a substrate is improved while the coating has excellent characteristics of the PVB and the acrylic resin, and the uniformity and the contractibility of a formed film are improved; in addition, the hardness, the wear resistance, the heat resistance and the acid and alkali corrosion resistance of a paint film are further improved by adding the superfine alpha-alumina subjected to ceramic treatment; by controlling the adding mode and the stirring speed of each auxiliary agent in the preparation process, the powder and the auxiliary agents can be better dispersed and mixed, the components can exert the maximum effect and simultaneously generate the synergistic effect, and the scratch-resistant, waterproof, heat-resistant and corrosion-resistant coating which is not easy to settle and coat is prepared.

Drawings

FIG. 1 is a picture of an uncoated metal specimen after being placed in a salt spray test chamber for 48 hours;

FIG. 2 is a picture of a painted metal coupon after being placed in a salt spray test chamber for 48 hours.

Detailed Description

The present invention is further described below in conjunction with the following figures and specific examples so that those skilled in the art may better understand the present invention and practice it, but the examples are not intended to limit the present invention.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

The experimental methods used in the following examples are conventional methods unless otherwise specified, and materials, reagents and the like used therein are commercially available without otherwise specified.

Example 1

The heat-resistant anticorrosive alumina coating comprises, by weight, 10 parts of PVB, 5 parts of acrylic resin, 10 parts of alumina, 0.005 part of silicone oil, 1 part of acrylic leveling agent MONENG-1153, 0.025 part of triethylhexylphosphoric acid, 0.025 part of polyacrylamide, 1 part of mica powder, 3 parts of calcium carbonate, 1 part of talc powder, 3 parts of kaolin, 5 parts of titanium dioxide and 50 parts of solvent (the volume ratio of ethanol to butanol is 2:1), and is prepared by the following preparation method:

(1) the alumina was ground thoroughly in a mortar and then placed in a muffle furnace for heat treatment at 1200 ℃ for 2 h.

(2) And (2) placing a mixed reagent of ethanol and butanol and acrylic resin in a stirring kettle, stirring for 15min at the rotating speed of 200r/min, then adding PVB, and continuously stirring for 1h at the rotating speed of 600r/min to obtain a mixture.

(3) And (3) sequentially adding the ceramic alumina, mica powder, calcium carbonate, talcum powder, kaolin and titanium dioxide into the mixture obtained in the step (2), stirring for 10min at the rotating speed of 200r/min, intermittently dropping silicone oil, MONENG-1153, triethylhexylphosphoric acid and polyacrylamide during stirring, stirring for 2h at the rotating speed of 800r/min after dropping to obtain a coating, and packaging the coating for later use.

Example 2

The heat-resistant anticorrosive alumina coating comprises, by weight, 20 parts of PVB, 20 parts of acrylic resin, 20 parts of alumina, 0.01 part of silicone oil, 2 parts of an acrylic leveling agent MONENG-1153, 0.05 part of triethylhexylphosphoric acid, 0.05 part of polyacrylamide, 3 parts of mica powder, 5 parts of calcium carbonate, 5 parts of talc powder, 5 parts of kaolin, 15 parts of titanium dioxide and 70 parts of a solvent (the volume ratio of ethanol to butanol is 2:1), and is prepared by the following preparation method:

(1) the alumina was ground thoroughly in a mortar and then placed in a muffle furnace for heat treatment at 1200 ℃ for 3 h.

(2) And (2) placing a mixed reagent of ethanol and butanol and acrylic resin in a stirring kettle, stirring at the rotating speed of 300r/min for 20min, adding PVB, and continuously stirring at the rotating speed of 800r/min for 1.5h to obtain a mixture.

(3) And (3) sequentially adding the ceramic alumina, mica powder, calcium carbonate, talcum powder, kaolin and titanium dioxide into the mixture obtained in the step (2), stirring for 20min at the rotating speed of 300r/min, intermittently dropping silicone oil, MONENG-1153, triethylhexylphosphoric acid and polyacrylamide during stirring, stirring for 3h at the rotating speed of 1000r/min after dropping to obtain a coating, and packaging the coating for later use.

Example 3

The heat-resistant anticorrosive alumina coating comprises, by weight, 15 parts of PVB, 10 parts of acrylic resin, 15 parts of alumina, 0.01 part of silicone oil, 2 parts of an acrylic leveling agent MONENG-1153, 0.05 part of triethylhexylphosphoric acid, 0.05 part of polyacrylamide, 1 part of mica powder, 3 parts of calcium carbonate, 1 part of talc powder, 3 parts of kaolin, 5 parts of titanium dioxide and 60 parts of a solvent (the volume ratio of ethanol to butanol is 2:1), and is prepared by the following preparation method:

(1) the alumina was ground thoroughly in a mortar and then placed in a muffle furnace for heat treatment at 1200 ℃ for 2 h.

(2) And (2) placing a mixed reagent of ethanol and butanol and acrylic resin in a stirring kettle, stirring for 15min at the rotating speed of 300r/min, then adding PVB, and continuously stirring for 1.5h at the rotating speed of 600r/min to obtain a mixture.

(3) And (3) sequentially adding the ceramic alumina, mica powder, calcium carbonate, talcum powder, kaolin and titanium dioxide into the mixture obtained in the step (2), stirring for 15min at the rotating speed of 300r/min, intermittently dropping silicone oil, MONENG-1153, triethylhexylphosphoric acid and polyacrylamide during stirring, stirring for 3h at the rotating speed of 600r/min after dropping to obtain a coating, and packaging the coating for later use.

Example 4

The heat-resistant anticorrosive alumina coating comprises, by weight, 25 parts of PVB, 5 parts of acrylic resin, 10 parts of alumina, 0.005 part of silicone oil, 1 part of acrylic leveling agent MONENG-1153, 0.025 part of triethylhexylphosphoric acid, 0.025 part of polyacrylamide, 3 parts of mica powder, 5 parts of calcium carbonate, 3 parts of talc powder, 5 parts of kaolin, 10 parts of titanium dioxide and 70 parts of solvent (the volume ratio of ethanol to butanol is 2:1), and is prepared by the following preparation method:

(1) the alumina was ground thoroughly in a mortar and then placed in a muffle furnace for heat treatment at 1200 ℃ for 2 h.

(2) And (2) placing a mixed reagent of ethanol and butanol and acrylic resin in a stirring kettle, stirring at the rotating speed of 250r/min for 18min, adding PVB, and continuously stirring at the rotating speed of 800r/min for 1h to obtain a mixture.

(3) And (3) sequentially adding the ceramic alumina, mica powder, calcium carbonate, talcum powder, kaolin and titanium dioxide into the mixture obtained in the step (2), stirring for 15min at the rotating speed of 250r/min, intermittently dropping silicone oil, MONENG-1153, triethylhexylphosphoric acid and polyacrylamide during stirring, stirring for 2h at the rotating speed of 800r/min after dropping to obtain a coating, and packaging the coating for later use.

Example 5

The heat-resistant anticorrosive alumina coating comprises, by weight, 10 parts of PVB, 20 parts of acrylic resin, 15 parts of alumina, 0.01 part of silicone oil, 1 part of acrylic leveling agent MONENG-1153, 0.05 part of triethylhexylphosphoric acid, 0.05 part of polyacrylamide, 2 parts of mica powder, 4 parts of calcium carbonate, 2 parts of talc powder, 3 parts of kaolin, 10 parts of titanium dioxide and 60 parts of solvent (the volume ratio of ethanol to butanol is 2:1), and is prepared by the following preparation method:

(1) the alumina was ground thoroughly in a mortar and then placed in a muffle furnace for heat treatment at 1200 ℃ for 2 h.

(2) And (2) placing a mixed reagent of ethanol and butanol and acrylic resin in a stirring kettle, stirring for 15min at the rotating speed of 200r/min, then adding PVB, and continuously stirring for 1h at the rotating speed of 600r/min to obtain a mixture.

(3) And (3) sequentially adding the ceramic alumina, mica powder, calcium carbonate, talcum powder, kaolin and titanium dioxide into the mixture obtained in the step (2), stirring for 10min at the rotating speed of 400r/min, intermittently dropping silicone oil, MONENG-1153, triethylhexylphosphoric acid and polyacrylamide during stirring, stirring for 3h at the rotating speed of 1000r/min after dropping to obtain a coating, and packaging the coating for later use.

Comparative example 1

Comparative example 5, the coating prepared by the same materials and weight parts in different feeding manners in the comparative example comprises, by weight, 10 parts of PVB, 20 parts of acrylic resin, 15 parts of alumina, 0.01 part of silicone oil, 1 part of acrylic leveling agent MONENG-1153, 0.05 part of triethylhexylphosphoric acid, 0.05 part of polyacrylamide, 2 parts of mica powder, 4 parts of calcium carbonate, 2 parts of talc powder, 3 parts of kaolin, 10 parts of titanium dioxide, and 60 parts of solvent (the volume ratio of ethanol to butanol is 2:1), and is prepared by the following preparation method:

(1) the alumina was ground thoroughly in a mortar and then placed in a muffle furnace for heat treatment at 1200 ℃ for 2 h.

(2) PVB, the ceramic alumina, mica powder, calcium carbonate, talcum powder, kaolin and titanium dioxide are added into a reaction kettle at one time, and then acrylic resin is added.

(3) Adding a mixed reagent of ethanol and butanol into a stirring kettle, and starting a stirrer.

(4) And simultaneously adding silicone oil, MONENG-1153, triethylhexyl phosphoric acid and polyacrylamide during stirring, and continuing stirring.

In the stirring process, can obviously observe the bold granule, and still be difficult to the dispersion through long-time stirring, handle through accelerating stirring speed and extension churning time, still can observe the agglomerate, and this phenomenon shows that the order of putting in the material and the mode of adding can produce great influence to the homogeneity of coating.

Comparative example 2

In comparison with example 1, the heat-resistant anticorrosive alumina coating prepared by reducing the feeding amount of PVB in the comparative example has the advantages that the adding amount of PVB is reduced to 5 parts, other components, metering and experimental operation are consistent with those in example 1, and the coating is prepared.

Comparative example 3

Compared with the example 3, the heat-resistant anticorrosive alumina coating prepared by reducing the feeding amount of alumina in the comparative example has the advantages that the adding amount of alumina is reduced to 5 parts, other components, metering and experimental operation are consistent with those in the example 3, and the coating is prepared.

Comparative example 4

The comparative example uses alumina which is not subjected to ceramic treatment to prepare a heat-resistant anticorrosive alumina coating which comprises, by weight, 25 parts of PVB, 5 parts of acrylic resin, 10 parts of alumina, 0.005 part of defoaming agent, 1 part of leveling agent, 0.05 part of dispersing agent, 3 parts of mica powder, 5 parts of calcium carbonate, 3 parts of talcum powder, 5 parts of kaolin, 10 parts of coloring pigment and 70 parts of solvent (the volume ratio of ethanol to butanol is 2: 1).

(1) The alumina is fully ground in a mortar and placed at room temperature for standby.

(2) And (2) placing a mixed reagent of ethanol and butanol and acrylic resin in a stirring kettle, stirring at the rotating speed of 250r/min for 18min, adding PVB, and continuously stirring at the rotating speed of 800r/min for 1.5h to obtain a mixture.

(3) And (3) sequentially adding alumina, mica powder, calcium carbonate, talcum powder, kaolin and titanium dioxide into the mixture obtained in the step (2), stirring for 15min at the rotating speed of 250r/min, discontinuously dripping silicone oil, MONENG-1153, triethylhexyl phosphoric acid and polyacrylamide during stirring, stirring for 2h at the rotating speed of 800r/min after dripping is finished, obtaining a coating, and packaging the coating for later use.

Comparative example 5

Comparative example 2, which was prepared by adding only one film-forming material 20 parts PVB and no acrylic resin, and the other components, measurements and experimental operations were in accordance with example 2.

Comparative example 6

Comparative example 2, only 20 parts of a film-forming substance was added to this comparative example, no PVB was added to the acrylic resin, and the other components, metering and experimental operations were in accordance with those of example 2, to prepare a coating.

Study of Properties

Coating experiment:

examples 1, 2, 4 and comparative examples 2, 4, 5, 6 were subjected to coating experiments on thin aluminium sheets.

The coatings prepared in the embodiments 1, 2 and 4 are respectively easy to coat on an aluminum plate to form a film, and the coating of a thin aluminum plate is bent and folded to a certain degree, so that a paint film on the surface of a sample plate is not cracked; the coatings prepared in comparative examples 2 and 4 are respectively coated on an aluminum plate to form a film, the thin aluminum plate is bent and folded to the same degree as the thin aluminum plate in the previous example, and the paint films on the surfaces of the thin aluminum plate have obvious cracks; the coating prepared in the comparative example 5 is coated on an aluminum plate to form a film, and the dried paint film is easy to peel off; the coating prepared in comparative example 6 is coated on an aluminum plate to form a film, and the dried paint film is soft and easy to damage after collision and easily damages the coated substrate.

Heat resistance test:

1. selecting two steel plates made of the same material, coating the coating prepared in the embodiment 5 on the surfaces of the two steel plates to obtain sample plates 1 and 2, putting the sample plate 1 into an oven, heating to 200 ℃, preserving heat for 120min, taking out the sample plate, cooling to normal temperature in air, and observing the surface appearance of the sample plate. The surface of sample plate 1 after heat resistance test treatment still maintains the initial smoothness, no cracking phenomenon occurs, and the surface appearance is basically not different from that of sample plate 2 without heat resistance test, which also shows that the coating of the invention has good temperature resistance.

2. Selecting two steel plates with the same material, respectively painting with the coatings prepared in the embodiment 3 and the comparative example 3 to obtain sample plates 1 and 2, putting the two sample plates into an oven, heating to 200 ℃, keeping the temperature for 120min, taking out the sample plates, air-cooling to normal temperature, and observing the surface appearance of the sample plates; the results show that sample plate 1 (coated with the paint prepared in example 3) maintained the initial planar smoothness, while sample plate 2 (coated with the paint prepared in comparative example 3) underwent high temperature testing with surface cracking and whitening, and it is known that reducing the amount of alumina added to the paint reduced the heat resistance of the paint film.

Salt spray test:

the uncoated steel plate and the coated steel plate were placed in a 35 ℃ salt spray test chamber, after 2 hours, a 5% sodium chloride solution was sprayed into the test chamber, and the test chamber was placed in a salt spray for 48 hours, as shown in fig. 1 and 2, and the uncoated steel plate surface was corroded and rusted (as shown in fig. 1), while the coated steel plate surface in fig. 2 did not generate rust.

Building exterior wall primer test:

the coatings of examples 1 to 5 were tested according to GB/T210-2007 primer for interior and exterior walls of buildings, and the results are shown in the following Table 1:

table 1 table of performance test data of each coating

The above-mentioned embodiments are merely preferred embodiments for fully illustrating the present invention, and the scope of the present invention is not limited thereto. The equivalent substitution or change made by the technical personnel in the technical field on the basis of the invention is all within the protection scope of the invention. The protection scope of the invention is subject to the claims.