CN116288316A - Composite coating, self-cleaning color coating, color steel plate and preparation method thereof - Google Patents

Abstract

The application relates to the technical field of coatings, in particular to a composite coating, a self-cleaning colored coating, a colored steel plate and a preparation method thereof; the composite coating includes N passivation layers and N primer layers, and N passivation layers The primer layer and N primer layers are arranged alternately, and the primer layer and the passivation layer are combined by chemical crosslinking; the self-cleaning color coating includes a composite coating and a topcoat coated on the surface of the composite coating The self-cleaning color steel plate includes a steel substrate and a self-cleaning color coating, and the self-cleaning color coating is coated on at least one side of the steel substrate; using The chemical bond between the chemical passivation layer and the primer layer improves the bonding force between the passivation layer and the primer layer, so it can improve the adhesion between the topcoat layer and the steel substrate, and then realize the self-cleaning improvement through the composite coating The effect of coating adhesion.

Description

Composite coating, self-cleaning color coating, color steel plate and preparation method thereof

technical field

The application relates to the technical field of coatings, in particular to a composite coating, a self-cleaning colored coating, a colored steel plate and a preparation method thereof.

Background technique

With the increasing environmental protection requirements and maintenance costs, self-cleaning coated steel plates with self-cleaning function have attracted widespread attention. Among them, the self-cleaning function is mainly divided into two types. One is to use the surface substances of the coating to make the surface of the steel plate appear The self-cleaning leaf surface phenomenon similar to the "lotus leaf effect" makes it difficult for pollutants to adhere to the surface of the steel plate and achieves the effect of "leaving mud without staining". The other is to use special substances in the coating to make it in the Under the action of light, the organic pollutants on the surface are degraded, and then rinsed with natural water or tap water, so that the degraded dust is taken away by water droplets or water flow to achieve self-cleaning.

However, due to the weak adhesion of the material of the self-cleaning coating, after a long period of use, the self-cleaning coating is easy to peel or fall off, making the steel plate lose the ability of self-cleaning, so how to improve the adhesion of the self-cleaning coating, It is a technical problem that needs to be solved urgently at present.

Contents of the invention

The application provides a composite coating, a self-cleaning colored coating, a colored steel plate and a preparation method thereof to solve the technical problem of low adhesion of the self-cleaning coating in the prior art.

In a first aspect, the application provides a composite coating, the composite coating includes N passivation layers and N primer layers, N passivation layers and N primer layers are arranged alternately, The primer layer and the passivation layer are bonded by chemical cross-linking, wherein N≧1 and N is a positive integer.

Optionally, the chemical composition of the primer layer includes polyurethane, epoxy resin, polyester resin.

Optionally, the thickness of the passivation layer is ≤1 μm.

Optionally, the primer layer has a thickness of 3 μm˜15 μm.

In a second aspect, the application provides a self-cleaning color coating, the self-cleaning color coating includes a composite coating and a topcoat layer coated on the surface of the composite coating, the innermost layer of the composite coating is layer is a passivation layer, the outermost layer of the composite coating is a primer layer, and the primer layer and the topcoat layer are combined by chemical crosslinking, and the topcoat layer is self-cleaning Functional topcoat layer.

Optionally, the chemical composition of the topcoat layer includes silicon-modified polyurethane and fluorocarbon polyester.

In a third aspect, the present application provides a self-cleaning colored steel plate, the self-cleaning colored steel plate includes a steel substrate and the self-cleaning colored coating described in the second aspect, the self-cleaning colored coating is coated on the steel On at least one side of the substrate, the innermost layer of the self-cleaning color coating is a passivation layer, and the outermost layer of the self-cleaning color coating is a topcoat layer.

In a fourth aspect, the present application provides a method for preparing the self-cleaning colored steel plate described in the third aspect, the method comprising:

performing chemical passivation on the steel substrate to obtain a first steel substrate containing a passivation layer;

Coating a primer material on the surface of the first steel substrate, then performing a first gradient baking, and then performing a first cooling, so as to form a primer layer on the surface of the passivation layer to obtain a second steel substrate;

The surface of the second steel substrate is coated with a topcoat material, followed by a second gradient baking, and then a second cooling, so as to form a topcoat layer on the surface of the primer layer to obtain a self-cleaning colored steel plate.

Optionally, the first gradient roasting includes a first roasting zone, a second roasting zone and a third roasting zone, the temperature of the first roasting zone is 155°C-165°C, and the temperature of the second roasting zone is The temperature of the baking zone is 215°C-225°C, and the temperature of the third baking zone is 250°C-265°C.

Optionally, the second gradient roasting includes a fourth roasting zone, a fifth roasting zone and a sixth roasting zone, the temperature of the fourth roasting zone is 210°C-225°C, the fifth The temperature of the baking zone is 230°C-240°C, and the temperature of the sixth baking zone is 245°C-265°C.

Compared with the prior art, the above-mentioned technical solutions provided by the embodiments of the present application have the following advantages:

In the composite coating provided in the embodiment of the present application, through the composite coating including N passivation layers and N primer layers, the combination mode of the passivation layer and the composite coating is controlled to be chemical cross-linking, and the chemical passivation The chemical bond between the passivation layer and the primer layer improves the bonding force between the passivation layer and the primer layer, and the primer layer will combine with the topcoat layer, so that the topcoat layer can be indirectly combined with the passivation layer. , and the passivation layer is attached to the surface of the steel substrate. Therefore, through the composite coating, the adhesion between the topcoat layer and the steel substrate can be improved, and then the adhesion of the self-cleaning coating can be improved through the composite coating.

Description of drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description serve to explain the principles of the invention.

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, In other words, other drawings can also be obtained from these drawings without paying creative labor.

Fig. 1 is the structural representation of the composite coating that the embodiment of the present application provides;

Fig. 2 is a schematic structural view of the self-cleaning color coating provided by the embodiment of the present application;

Fig. 3 is the structural representation of the color steel plate that the embodiment of the present application provides;

Fig. 4 is a schematic flow chart of the method provided by the embodiment of the present application;

Figure 5 is a schematic diagram of the product structure of the colored steel plate provided by the embodiment of the present application;

Among them, 1-passivation layer, 2-primer layer, 3-finish layer, 4-steel substrate.

Detailed ways

The present invention will be described in detail below in conjunction with specific implementations and examples, and the advantages and various effects of the present invention will be presented more clearly. Those skilled in the art should understand that these specific implementations and examples are used to illustrate the present invention, not to limit the present invention.

Throughout the specification, unless otherwise specified, terms used herein should be understood as commonly used in the art. Therefore, unless otherwise defined, 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. In case of conflict, this specification shall take precedence.

Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

The technical solutions provided by the embodiments of the present invention are to solve the above-mentioned technical problems, and the general idea is as follows:

In one embodiment of the present application, as shown in Figure 1, a kind of composite coating is provided, and described composite coating comprises N passivation layer 1 and N primer layer 2, and N described passivation layer 1 Alternately arranged with N primer layers 2, the primer layers 2 are combined with the passivation layer 1 through chemical cross-linking, wherein, N≥1 and N is a positive integer.

In some optional embodiments, the chemical composition of the primer layer 2 includes polyurethane, epoxy resin, polyester resin.

In the embodiment of the present application, the positive effect of controlling the chemical composition of the primer layer 2 is that the polyurethane material has good adhesion properties, and the polyurethane-type primer layer 2 can form between the passivation layer 1 and the topcoat layer 3. The chemical cross-linking structure can effectively improve the adhesion between the passivation layer 1 and the topcoat layer 3, thereby improving the adhesion of the self-cleaning coating.

In some optional embodiments, the thickness of the passivation layer 1 is ≤1 μm.

In the embodiment of the present application, the positive effect of controlling the thickness of the passivation layer 1 to ≤1 μm is to improve the adhesion between the primer layer and the steel substrate.

In some optional embodiments, the passivation layer 1 is a reticular passivation layer 1, wherein the passivation solution required for the formation of the passivation layer 1 can be a Chemetall brand passivation agent, It can also be passivating agent of Henkel brand.

In the embodiment of the present application, the control passivation layer 1 is a reticular passivation layer 1, because the reticular passivation layer 1 can increase the chemical crosslinking area of the passivation layer 1 and the primer layer 2, thereby further increasing the passivation layer 1 And the adhesion of the primer layer 2, further improving the adhesion of the composite coating.

In some optional embodiments, the primer layer 2 has a thickness of 3 μm˜15 μm.

In the embodiment of the present application, the positive effect of controlling the thickness of the primer layer 2 to 3 μm to 15 μm is to improve the corrosion resistance of the product and improve the adhesion with the topcoat layer.

In one embodiment of the present application, as shown in Figure 2, a self-cleaning color coating is provided, the self-cleaning color coating includes a composite coating and a topcoat layer 3 coated on the surface of the composite coating , the innermost layer of the composite coating is a passivation layer 1, the outermost layer of the composite coating is a primer layer 2, and the primer layer 2 and the topcoat layer 3 are chemically crosslinked In combination, the topcoat layer 3 is a topcoat layer 3 with a self-cleaning function.

In the embodiment of the present application, the bonding method between the control composite coating and the topcoat layer 3 is chemical crosslinking, and at the same time, the control topcoat has a self-cleaning function, and then through chemical crosslinking, the topcoat layer 3 and the composite coating The primer layer 2 in the layer is firmly combined, thereby improving the adhesion between the topcoat layer 3 and the primer layer 2, thereby improving the adhesion of the self-cleaning color coating, and paving the way for the subsequent improvement of the adhesion of the self-cleaning color steel plate.

In some optional embodiments, the chemical composition of the topcoat layer 3 includes silicon-modified polyurethane, epoxy resin, polyester resin.

In the embodiment of the present application, the positive effect of controlling the chemical composition of the topcoat layer 3 is to improve the self-cleaning performance and aging function of the color-coated board and make it aesthetically pleasing for a long time.

In one embodiment of the present application, as shown in FIG. 3 , a self-cleaning color steel plate is provided, the self-cleaning color steel plate includes a steel substrate 4 and the self-cleaning color coating, and the self-cleaning color coating is coated with Covering at least one side of the steel substrate 4, the innermost layer of the self-cleaning color coating is a passivation layer 1, and the outermost layer of the self-cleaning color coating is a topcoat layer 3, wherein the steel substrate 4 It can be hot-dip galvanized sheet, galvanized sheet or galvanized aluminum-magnesium sheet.

In the embodiment of the present application, the coating method of the self-cleaning color coating and the steel substrate 4 is controlled, and the distribution of the passivation layer 1 and the topcoat layer 3 in the self-cleaning color coating is controlled, because both sides of the steel substrate 4 can be Passivation is carried out, so by controlling the distribution of the passivation layer 1, the adhesion of the self-cleaning color coating on one or both sides of the steel substrate 4 can be increased, and then color steel products with different coating distributions can be selectively obtained.

In one embodiment of the present application, as shown in Figure 4, a method for preparing a self-cleaning colored steel plate is provided, the method comprising:

S1. Perform chemical passivation on the steel substrate 4 to obtain a first steel substrate 4 containing a passivation layer 1;

S2. Coating primer material on the surface of the first steel substrate 4, then performing the first gradient baking, and then performing the first cooling, so as to form a primer layer 2 on the surface of the passivation layer 1 to obtain a second steel substrate Substrate 4;

S3. Coat the topcoat material on the surface of the second steel substrate 4, then carry out the second gradient baking, and then carry out the second cooling, so as to realize the formation of the topcoat layer 3 on the surface of the primer layer 2, and obtain a self-cleaning color steel plate.

In the embodiment of the present application, by controlling the first gradient baking after the primer material is coated and the second gradient baking after the topcoat material is coated, the gradient baking method can effectively improve the primer layer 2 or Cure rate of topcoat layer 3.

In some optional embodiments, the first gradient roasting includes a first roasting zone, a second roasting zone and a third roasting zone, and the temperature of the first roasting zone is 155°C-165°C , the temperature of the second baking zone is 215°C-225°C, and the temperature of the third baking zone is 250°C-265°C.

In the embodiment of the present application, the positive effect of the temperature of the first baking zone being 155° C. to 165° C. is to remove solvents in the solution and other substances that have no effect on improving the adhesion.

The positive effect of the temperature of the second baking zone being 215°C to 225°C is to remove the leveling agent, solvent, defoamer and other substances in the coating solution, and to promote the crosslinking reaction between the filler and the curing agent.

The positive effect of the temperature of the third baking zone being 250° C. to 265° C. is that in addition to the above effects, it can also improve the stability of the self-cleaning coating performance on the surface of the paint film.

In some optional embodiments, the second gradient roasting includes a fourth roasting zone, a fifth roasting zone and a sixth roasting zone, and the temperature of the fourth roasting zone is 210°C-225°C , the temperature of the fifth baking zone is 230°C-240°C, and the temperature of the sixth baking zone is 245°C-265°C.

In the embodiment of the present application, the positive effect of the temperature of the fourth baking zone being 210° C. to 225° C. is to promote the reaction between the catalyst, dispersant, etc. in the coating liquid and the resin.

The positive effect of the temperature of the fifth baking zone being 230°C to 240°C is to promote the cross-linking reaction between fillers, curing agents and resins in the coating liquid, and prevent excessive high temperature from causing blistering and explosion on the surface of the color-coated board. holes etc.

The positive effect of the temperature of the sixth baking zone being 245° C. to 265° C. is to fully complete the cross-linking reaction of the coating solution and improve the cleaning performance of the coating.

Example 1

A composite coating, comprising 1 passivation layer 1 and 1 primer layer 2, 1 passivation layer 1 and 1 primer layer 2 alternately arranged, passivation layer 1 includes chemical passivation layer, primer layer 2 and the passivation layer 1 are combined by chemical cross-linking.

The chemical composition of the primer layer 2 is polyurethane.

The passivation layer 1 has a thickness of 1 μm.

The passivation layer 1 is a mesh passivation layer 1 .

The primer layer 2 has a thickness of 10 μm.

As shown in Figure 2, a kind of self-cleaning colored coating is provided, and self-cleaning colored coating comprises composite coating and is coated on the finish paint layer 3 on composite coating surface, and the innermost layer of composite coating is passivation layer 1 , the outermost layer of the composite coating is the primer layer 2, the primer layer 2 and the topcoat layer 3 are combined by chemical crosslinking, and the topcoat layer 3 is a topcoat layer 3 with a self-cleaning function.

The chemical composition of the topcoat layer 3 includes silicon-modified polyurethane.

The thickness of the topcoat layer 3 is 25 μm

As shown in Figure 3, a kind of self-cleaning color steel plate is provided, and self-cleaning color steel plate comprises steel substrate 4 and self-cleaning color coating, and self-cleaning color coating is coated on the opposite two sides of steel substrate 4, and self-cleaning color coating The innermost layer of the self-cleaning color coating is the passivation layer 1, and the outermost layer of the self-cleaning color coating is the topcoat layer 3, wherein the steel substrate 4 can be hot-dip galvanized sheet, galvanized sheet or galvanized aluminum-magnesium sheet, two upper and lower The passivation layer 1 has the same thickness, the upper and lower primer layers 2 have the same thickness, and the upper and lower paint-free layers have the same thickness.

As shown in Figure 4, a kind of preparation method of self-cleaning colored steel plate is provided, and method comprises:

S1. Perform chemical passivation on the steel substrate 4 to obtain the first steel substrate 4 containing the passivation layer 1;

S2. Coating primer material on the surface of the first steel substrate 4, then performing the first gradient baking, and then performing the first cooling, so as to form the primer layer 2 on the surface of the passivation layer 1 to obtain the second steel substrate 4 ;

S3. Coat the topcoat material on the surface of the second steel substrate 4, then carry out the second gradient baking, and then carry out the second cooling, so as to realize the formation of the topcoat layer 3 on the surface of the primer layer 2, as shown in Figure 5 Self-cleaning color steel plate.

The first gradient baking includes the first baking zone, the second baking zone and the third baking zone. °C, the temperature of the third baking zone is 250 °C to 265 °C.

The second gradient baking includes the fourth baking zone, the fifth baking zone and the sixth baking zone, the temperature of the fourth baking zone is 210 ℃ ~ 225 ℃, the temperature of the fifth baking zone is 230 ℃ ~ 240 °C, the temperature of the sixth baking zone is 245 °C to 265 °C.

The process parameters of each embodiment and comparative example are as shown in table 1.

Table 1

Wherein, the difference between Comparative Example 1 and Example 1 is that no composite coating is used in Comparative Example 1, only the combination of steel substrate 4 and topcoat layer 3 is used;

The difference between Comparative Example 2 and Example 1 is that only passivation layer 1 is used in Comparative Example 2;

The difference between Comparative Example 3 and Example 1 is that only primer layer 2 is used in Comparative Example 3.

Related experiments:

Performance tests were performed on the colored steel plates of the various examples and comparative examples, and the results are shown in Table 2.

The test methods of relevant experiments are in accordance with GB/713449-2019.

Table 2

Specific analysis of Table 2:

The adhesion level refers to the adhesion of the self-cleaning color coating on the steel substrate 4, and the smaller the number of the adhesion level, the greater the adhesion.

Gloss refers to the physical quantity that evaluates the ability of the surface of the self-cleaning color coating to reflect light. The more the gloss meets the standard, the more uniform the material distribution of the self-cleaning color coating is.

The color difference value refers to the degree of color difference of the self-cleaning color coating in the same area. The smaller the color difference value, the more uniform the color of the self-cleaning color coating.

As can be seen from the data of Examples 1-5, adopt the composite coating of the present application, control the passivation layer 1 to be a chemical passivation layer, then control the combination mode of the passivation layer 1 and the composite coating to be a chemical cross-linking combination, utilize chemical The chemical bond between the passivation layer and the primer layer 2 improves the binding force between the passivation layer 1 and the primer layer 2, so that the topcoat layer 3 can be indirectly combined with the passivation layer 1 firmly, so that the surface can be improved. The adhesion between the paint layer 3 and the steel substrate 4 can be improved, and then the effect of improving the adhesion of the self-cleaning coating through the composite coating can be achieved.

From the data of Comparative Examples 1-5, it can be seen that:

Not using the composite coating of the present application or not using the combination of the passivation layer 1 and the primer layer 2 in the composite coating will affect the adhesion level, gloss and color difference of the colored steel plate to varying degrees.

One or more technical solutions in the embodiments of the present application also have at least the following technical effects or advantages:

(1) For the composite coating provided in the embodiment of the present application, the passivation layer 1 is controlled to be a chemical passivation layer, and the combination mode of the passivation layer 1 and the composite coating is controlled to be chemical cross-linking combination, and the chemical passivation layer and the bottom The chemical bond between the paint layer 2 improves the binding force between the passivation layer 1 and the primer layer 2, so that the topcoat layer 3 can be indirectly combined with the passivation layer 1 firmly, so it can improve the bond between the topcoat layer 3 and the steel. The previous adhesion of the substrate 4 is achieved, and the effect of improving the adhesion of the self-cleaning coating through the composite coating is realized.

(2) The composite coating provided by the embodiment of the present application, owing to having adopted the primer layer 2 of polyurethane, and polyurethane also has certain anticorrosion ability, so the composite coating of the present application can also improve the resistance of color steel plate to a certain extent corrosive.

(3) The self-cleaning color coating provided by the embodiment of the present application, due to the use of a reticular chemical passivation layer structure, the reticular passivation layer 1 structure can improve the adhesion between the passivation layer 1 and the primer layer 2. Focus on it, so as to further improve the adhesion of the colored steel plate.

(4) The color steel plate provided by the embodiment of the present application provides good corrosion resistance and strength for the color steel plate through the steel substrate 4, so as to ensure the universality of the service performance of the color steel plate, because the passivation layer 1 has a good network structure , so it can provide good adhesion between the steel substrate 4 and the primer layer 2, thereby further improving the adhesion of the colored steel plate.

(5) The method provided in the embodiment of the present application can effectively coat and cure the primer layer 2 and the topcoat layer 3 through two gradient bakes, thereby further ensuring the adhesion of the colored steel plate.

It should be noted that in this article, relative terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply these No such actual relationship or order exists between entities or operations. Furthermore, the term "comprises", "comprises" or any other variation thereof is intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus comprising a set of elements includes not only those elements, but also includes elements not expressly listed. other elements of or also include elements inherent in such a process, method, article, or device. Without further limitations, an element defined by the statement "comprising..." does not exclude the presence of additional same elements in the process, method, article or device comprising said element.

Neither the endpoints nor any values of the ranges disclosed herein are limited to such precise ranges or values, and these ranges or values are understood to include values approaching these ranges or values. For numerical ranges, between the endpoints of each range, between the endpoints of each range and individual point values, and between individual point values can be combined with each other to obtain one or more new numerical ranges, these values Ranges should be considered as specifically disclosed herein.

The above descriptions are only specific embodiments of the present invention, so that those skilled in the art can understand or implement the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Accordingly, the present invention will not be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims (10)

1. The composite coating is characterized by comprising N passivation layers and N primer layers, wherein the N passivation layers and the N primer layers are alternately arranged, the primer layers and the passivation layers are combined in a chemical crosslinking mode, N is more than or equal to 1, and N is a positive integer.

2. The composite coating of claim 1, wherein the primer layer comprises a chemical composition comprising polyurethane, epoxy, polyester resin.

3. The composite coating of claim 1, wherein the passivation layer has a thickness of 1 μm or less.

4. The composite coating according to claim 1 or 2, wherein the primer layer has a thickness of 3 μm to 15 μm.

5. The self-cleaning color coating is characterized by comprising a composite coating and a finish paint layer coated on the surface of the composite coating, wherein the innermost layer of the composite coating is a passivation layer, the outermost layer of the composite coating is a primer layer, the primer layer and the finish paint layer are combined in a chemical crosslinking mode, and the finish paint layer is a finish paint layer with a self-cleaning function.

6. The self-cleaning color coating according to claim 5, characterized in that the chemical composition of the topcoat layer comprises silicon modified polyurethane, fluorocarbon polyester, etc.

7. A self-cleaning color steel plate, which is characterized by comprising a steel substrate and the self-cleaning color coating according to any one of claims 5 or 6, wherein the self-cleaning color coating is coated on at least one surface of the steel substrate, the innermost layer of the self-cleaning color coating is a passivation layer, and the outermost layer of the self-cleaning color coating is a finish paint layer.

8. A method of producing the self-cleaning color steel sheet according to claim 7, comprising:

passivating the steel substrate to obtain a first steel substrate containing a passivation layer;

coating a primer material on the surface of the first steel substrate, then carrying out first gradient baking, and then carrying out first cooling to form a primer layer on the surface of the passivation layer so as to obtain a second steel substrate;

and coating a finish paint material on the surface of the second steel substrate, then carrying out second gradient baking, and then carrying out second cooling to form a finish paint layer on the surface of the primer layer, thereby obtaining the self-cleaning color steel plate.

9. The method of claim 8, wherein the first gradient bake comprises a first bake zone, a second bake zone, and a third bake zone, the first bake zone having a temperature of 155 ℃ to 165 ℃, the second bake zone having a temperature of 215 ℃ to 225 ℃, and the third bake zone having a temperature of 250 ℃ to 265 ℃.

10. The method of claim 8, wherein the second gradient bake comprises a fourth bake zone, a fifth bake zone, and a sixth bake zone, the fourth bake zone having a temperature of 210 ℃ to 225 ℃, the fifth bake zone having a temperature of 230 ℃ to 240 ℃, and the sixth bake zone having a temperature of 245 ℃ to 265 ℃.

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