An aqueous fluorocarbon paint and its preparation method

Abstract

This application relates to the technical field of coatings, and specifically discloses an aqueous fluorocarbon paint and a preparation method thereof. An aqueous fluorocarbon paint comprises component A and component B; Component A includes 30 - 60 parts of an aqueous fluorinated acrylic emulsion; 15 - 20 parts of a filler; 2 - 4 parts of an auxiliary agent; 4 - 8 parts of a polyetheramine; 10 - 15 parts of water; Component B includes 20 - 40 parts of an isocyanate curing agent; 5 - 10 parts of a perfluoropolyether derivative; The perfluoropolyether derivative is a perfluoropolyether carboxylic acid or a perfluoropolyether carboxylate; The preparation method is as follows: After mixing the aqueous fluorinated acrylic emulsion, the filler, the water and the polyetheramine, component A is obtained; After mixing the isocyanate curing agent and the perfluoropolyether derivative, component B is obtained; After mixing component A and component B, an aqueous fluorocarbon paint is obtained. The aqueous fluorocarbon paint of this application has high adhesion and strong chemical stability, can be directly sprayed on the surface of a substrate, and improves the corrosion resistance and aging resistance of the substrate.

Description

Technical Field

[0001] This application relates to the technical field of coatings, and more specifically, to a waterborne fluorocarbon paint and a preparation method thereof. Background Art

[0002] Aluminum profiles have the characteristics of low density, light weight, strong processability and plasticity, etc., and are widely used in the field of building and home furnishing. In order to improve the corrosion resistance and aging resistance of aluminum profiles and improve the surface decoration effect of aluminum profiles, surface treatment is usually required.

[0003] Fluorocarbon paint is a type of paint with fluorocarbon resin as the main film-forming substance. Due to the high bond energy (486 KJ / mol) of the C-F bond in fluorocarbon resin, small F atomic radius, low polarizability, etc., fluorocarbon paint has the characteristics of super weather resistance, corrosion resistance, chemical resistance, etc. Therefore, aluminum profiles are usually surface-treated by spraying fluorocarbon paint to improve their corrosion resistance and aging resistance.

[0004] However, the surface energy of fluorocarbon paint is relatively low, the wettability to aluminum profiles is poor, and it is not easy to adhere to aluminum profiles. Therefore, before spraying fluorocarbon paint on the surface of aluminum profiles, a primer needs to be applied, which increases the process steps of surface treatment of aluminum profiles. Summary of the Invention

[0005] In order to improve the adhesion of fluorocarbon paint, this application provides a waterborne fluorocarbon paint and a preparation method thereof.

[0006] In the first aspect, this application provides a waterborne fluorocarbon paint, adopting the following technical solution:

[0007] A waterborne fluorocarbon paint, comprising component A and component B;

[0008] Component A includes the following components in parts by weight:

[0009] 30 - 60 parts of waterborne fluorinated acrylic emulsion;

[0010] 15 - 20 parts of filler;

[0011] 2 - 4 parts of auxiliary agent;

[0012] 4 - 8 parts of polyetheramine;

[0013] 10 - 15 parts of water;

[0014] Component B includes the following components in parts by weight:

[0015] 20 - 40 parts of isocyanate curing agent;

[0016] 5 - 10 parts of perfluoropolyether derivative;

[0017] The perfluoropolyether derivative is perfluoropolyether carboxylic acid or perfluoropolyether carboxylate.

[0018] By adopting the above technical solution, after mixing component A and component B, the isocyanate curing agent, perfluoropolyether derivative, waterborne fluorinated acrylic emulsion and polyetheramine can react for crosslinking curing, so that the waterborne fluorocarbon paint is cured into a paint film. On the one hand, both the waterborne fluorinated acrylic emulsion and the perfluoropolyether derivative contain polar hydroxyl and carboxyl groups, and have good wettability to the substrate. They can be directly sprayed on the substrate and undergo dehydration condensation with the hydroxyl groups on the substrate surface, which is beneficial to increasing the adhesion between the paint film and the substrate and reducing the use of primer. On the other hand, during the film-forming process of the waterborne fluorocarbon paint, the perfluoropolyether derivative and the waterborne fluorinated acrylic emulsion polymerize into a network structure, which not only increases the density of the paint film, improves the strength of the paint film, but also reduces the surface tension of the paint film and improves the chemical stability of the paint film.

[0019] Preferably, in the waterborne fluorocarbon paint, the weight ratio of the waterborne fluorinated acrylic emulsion to the perfluoropolyether derivative is 1:(0.14 - 0.19).

[0020] By adopting the above technical solution, after mixing the waterborne fluorinated acrylic emulsion and the perfluoropolyether derivative according to the above weight ratio, the obtained waterborne fluorocarbon paint contains a certain content of polar groups and non-polar groups, which is beneficial to improving the adhesion and chemical stability of the obtained waterborne fluorocarbon paint.

[0021] Preferably, the molecular weight of the perfluoropolyether derivative is 2000 - 4000.

[0022] By adopting the above technical solution, the perfluoropolyether derivative with the above molecular weight not only has a strong ability to reduce surface tension, but also has good water solubility. When adding the perfluoropolyether derivative with the above molecular weight to the waterborne fluorinated acrylic emulsion, water and other components for film-forming curing, a large number of polar groups are dispersed in the polymerized network structure, improving the adhesion of the paint film to the substrate. At the same time, the perfluoropolyether derivative can also migrate to the surface of the paint film, reducing the surface tension of the paint film and improving the chemical stability of the paint film.

[0023] Preferably, the perfluoropolyether carboxylate is one or both of sodium perfluoropolyether carboxylate and ammonium perfluoropolyether carboxylate.

[0024] By adopting the above technical solution, sodium perfluoropolyether carboxylate and ammonium perfluoropolyether carboxylate have good water solubility and good dispersibility in the waterborne fluorinated acrylic emulsion, water and other components, so that a large number of polar groups are dispersed in the network structure formed by the polymerization of the perfluoropolyether derivative and the waterborne fluorinated acrylic emulsion, which is beneficial to improving the adhesion of the paint film to the substrate. At the same time, the perfluoropolyether carboxylate has biodegradability and low toxicity, and the obtained waterborne fluorocarbon coating has good environmental protection performance.

[0025] Preferably, the polyetheramine is a modified polyetheramine, and the preparation method of the modified polyetheramine is as follows: stir and mix the polyetheramine and epoxy group-containing silane to obtain the modified polyetheramine;

[0026] The polyetheramine is a primary amine.

[0027] By adopting the above technical solution, after mixing the polyetheramine and epoxy group-containing silane, the polyetheramine can react with the epoxy group to obtain a modified polyetheramine containing secondary amine, hydroxyl group and siloxane group. The modified polyetheramine can be hydrolyzed in water to form silanol. Since silanol can undergo dehydration condensation with the hydroxyl groups on the substrate surface, the adhesion of the paint film is improved. At the same time, the modified polyetheramine can react with perfluoropolyether derivatives and isocyanate curing agents, introducing siloxane bonds with relatively high bond dissociation energy into the waterborne fluorocarbon paint, thereby improving the chemical stability of the waterborne fluorocarbon paint.

[0028] Preferably, in the preparation method of the modified polyetheramine, the weight ratio of the polyetheramine to the epoxy group-containing silane is 1:(0.2 - 0.4).

[0029] By adopting the above technical solution, using a small amount of epoxy group-containing silane to modify the polyetheramine can optimize the content of silanol after hydrolysis of the modified polyetheramine. Therefore, the component A obtained by mixing the above modified polyetheramine with components such as waterborne fluorinated acrylic emulsion and water has good fluidity, can quickly wet the substrate, and is beneficial to improving the adhesion of the paint film.

[0030] Preferably, the epoxy group-containing silane is one or more of 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, and 3-glycidoxypropylmethyldimethoxysilane.

[0031] By adopting the above technical solution, using an aliphatic epoxy group-containing silane with a single epoxy group to modify the polyetheramine, the obtained modified polyetheramine not only has good dispersibility in component A, but also has good reactivity with perfluoropolyether derivatives after being mixed with component B, which is beneficial to improving the curing rate of the waterborne fluorocarbon paint.

[0032] Preferably, the polyetheramine is a mono-polyetheramine.

[0033] By adopting the above technical solution, after mixing raw material components such as mono-polyetheramine and perfluoropolyether derivatives, the obtained waterborne fluorocarbon paint has good fluidity, can quickly wet the substrate surface, and improves the adhesion to the substrate.

[0034] In the second aspect, the present application provides a preparation method of a waterborne fluorocarbon paint, adopting the following technical solution:

[0035] A preparation method of a waterborne fluorocarbon paint includes the following preparation steps:

[0036] S1: Mix the aqueous fluorinated acrylic emulsion, filler, water, and polyetheramine to obtain Component A;

[0037] S2: Mix the isocyanate curing agent and perfluoropolyether derivative to obtain Component B;

[0038] S3: Mix Component A and Component B to obtain the aqueous fluorocarbon paint.

[0039] By adopting the above technical solution, the present application can obtain the aqueous fluorocarbon paint after stirring and mixing the raw material components. The preparation method is simple and suitable for large-scale production. At the same time, in the related art, the curing temperature after fluorocarbon spraying on aluminum is generally between 180°C and 250°C. However, the aqueous fluorocarbon paint of the present application can be cured at room temperature, reducing the curing temperature and saving energy consumption.

[0040] In summary, the present application has the following beneficial effects:

[0041] 1. The present application uses raw material components such as aqueous fluorinated acrylic emulsion, polyetheramine, perfluoropolyether derivative, and aqueous isocyanate for crosslinking curing, introducing polar groups and non-polar groups into the aqueous fluorocarbon paint, which can increase the adhesion between the aqueous fluorocarbon paint and the substrate surface, reduce the surface tension of the film after curing of the aqueous fluorocarbon paint, and improve the chemical stability of the film;

[0042] 2. The present application modifies polyetheramine with epoxy group silane, introducing siloxane groups into the molecular structure of polyetheramine. The silanol formed by hydrolysis of the siloxane groups can condense with the hydroxyl groups on the substrate surface, which is beneficial to further improving the adhesion between the aqueous fluorocarbon paint and the substrate surface;

[0043] 3. The preparation method of the aqueous fluorocarbon paint of the present application is simple and suitable for large-scale production. Detailed Embodiments

[0044] The following further elaborates on the present application with reference to embodiments.

[0045] Except for the following special instructions, the raw materials used in the embodiments of the present application are not commercially available.

[0046] Perfluoropolyether carboxylic acid, perfluoropolyether carboxylate, and perfluoropolyether carboxylate ammonium salt are all purchased from Shanghai Biyang Industry Co., Ltd.;

[0047] 3-aminopropylmethyldiethoxysilane is purchased from Nanjing Nengde New Material Technology Co., Ltd.;

[0048] Polyetheramine is purchased from Chenghua Co., Ltd.

[0049] Preparation Examples

[0050] Preparation Example 1

[0051] A modified polyetheramine, and the raw materials and their corresponding weights (kg) are shown in the following table.

[0052]

[0053] The preparation method of the above-mentioned modified polyetheramine is as follows: Stir and mix polyetheramine and epoxy group silane for 10 minutes to obtain the modified polyetheramine.

[0054] In the preparation example of the present application, the polyetheramine is polyetheramine CAM-2070, which is a primary amine based on the copolymer main chain.

[0055] The epoxy group silane is 3-aminopropylmethyldiethoxysilane.

[0056] Preparation Examples 2-3

[0057] A modified polyetheramine, which is different from Preparation Example 1 in that the raw materials and their corresponding weights (kg) are shown in the following table.

[0058]

[0059] Preparation Example 4

[0060] A modified polyetheramine, which is different from Preparation Example 1 in that the polyetheramine is a water-soluble aliphatic diamine with the brand name CAED-600.

[0061] Performance detection

[0062] For the waterborne fluorocarbon paints obtained in the examples and comparative examples of the present application, adhesion, surface drying time, wet heat and cold cycle resistance, acid rain resistance, alkali resistance, water resistance, washability and stain resistance are detected, and the detection standards are as follows:

[0063] Adhesion: Detected according to the standard of GB / T 5210—2006;

[0064] Surface drying time: Detected according to the standard of GB / T 1728-1979(1989);

[0065] Wet heat and cold cycle resistance: Detected according to the standard of JG / T 25-2017, and record the number of cycles without abnormality of the paint film;

[0066] Acid rain resistance: Detected according to the standard of GB / T 9274-1998, and record the time without abnormality of the paint film;

[0067] Alkali resistance: Detected according to the standard of GB / T 9265-2009, and record the time without abnormality of the paint film;

[0068] Water resistance: Tested according to the standard of GB / T 1733-1993, record the time when the paint film has no abnormality;

[0069] Scrub resistance: Tested according to the standard of GB / T 9755-2014, record the maximum number of scrubbing times when the paint film has no abnormality;

[0070] Stain resistance: Tested according to the standard of GB / T 9780-2013, test the decline rate of the reflectance coefficient.

[0071] Examples

[0072] Example 1

[0073] An aqueous fluorocarbon paint, the raw materials and their corresponding weights (kg) are shown in the following table.

[0074]

[0075] The preparation method of the above aqueous fluorocarbon paint includes the following preparation steps:

[0076] S1: Mix the aqueous fluorinated acrylic emulsion, filler, auxiliary agent, water and polyetheramine to obtain component A;

[0077] S2: Mix the isocyanate curing agent and the perfluoropolyether derivative to obtain component B;

[0078] S2: Mix component A and component B to obtain the aqueous fluorocarbon paint.

[0079] In the embodiment of the present application, the aqueous fluorinated acrylic emulsion, with the brand name Ruifeng RF-102, is purchased from Ruifeng Fluorochemical.

[0080] The filler is titanium dioxide and the auxiliary agent is an antifoaming agent.

[0081] The polyetheramine is the modified polyetheramine prepared in Preparation Example 1.

[0082] The perfluoropolyether derivative is ammonium perfluoropolyether carboxylate with a molecular weight of 3000.

[0083] The isocyanate curing agent is hexamethylene diisocyanate.

[0084] Examples 2-5

[0085] An aqueous fluorocarbon paint, which is different from Example 1 in that the raw materials and their corresponding weights (kg) are shown in the following table.

[0086]

[0087] The waterborne fluorocarbon paints obtained in Examples 1-5 of this application were tested for adhesion, surface drying time, wet-heat cycling resistance, acid rain resistance, alkali resistance, water resistance, scrub resistance, and stain resistance. The test results are shown in the following table.

[0088]

[0089] By analyzing the data in the above table, it can be seen that the waterborne fluorocarbon paints obtained in Examples 1-5 have an adhesion as high as 10.9-13.5 MPa, a surface drying time as low as 0.35-0.43 h, a wet-heat cycling resistance as high as 10-12 times, an acid rain resistance as high as 48-72 h, an alkali resistance as high as 168-180 h, a water resistance as high as 168-180 h, a reflection coefficient decrease rate as low as 3.5-4.6%, and a scrub resistance as high as 20,000-26,000 times. This shows that the waterborne fluorocarbon paints obtained in Examples 1-5 of this application have the advantages of high adhesion, fast drying, and excellent chemical resistance.

[0090] By comparing Examples 1, 2, 3 with Examples 4 and 5, it can be seen that Examples 1, 2, and 3 have higher adhesion than Examples 4 and 5. This shows that when the weight ratio of the waterborne fluorinated acrylic emulsion to the perfluoropolyether derivative in the total raw materials for the preparation of the waterborne fluorocarbon paint is 1:(0.14-0.19), the adhesion and chemical resistance of the waterborne fluorocarbon paint can be improved.

[0091] Examples 6-9

[0092] A waterborne fluorocarbon paint, which is different from Example 1 in that the molecular weight of the ammonium perfluoropolyether carboxylate is as shown in the following table.

[0093]

[0094] The waterborne fluorocarbon paints obtained in Examples 6-9 of this application were tested for adhesion and stain resistance. The test results are shown in the following table.

[0095]

[0096] From the data analysis of the above table, it can be seen that compared with Examples 6 and 7, although the adhesion of Example 8 increases, the decrease rate of the reflection coefficient increases; compared with Examples 6 and 7, the adhesion of Example 9 decreases and the decrease rate of the reflection coefficient increases. This shows that in the total raw materials for the preparation of the waterborne fluorocarbon paint, when the molecular weight of the perfluoropolyether derivative is 2000 - 4000, the obtained waterborne fluorocarbon paint has more excellent chemical resistance on the basis of having higher adhesion. The reason may be that the waterborne fluorocarbon paint prepared from the perfluoropolyether derivative with a molecular weight of 2000 - 4000 and raw materials such as the waterborne fluorinated acrylic emulsion has appropriate contents of polar groups and non-polar groups, can adhere to the surface of the substrate, and reduce the surface tension of the substrate surface.

[0097] Example 10

[0098] A waterborne fluorocarbon paint, which is different from Example 1 in that the perfluoropolyether derivative is sodium perfluoropolyether carboxylate.

[0099] Example 11

[0100] A waterborne fluorocarbon paint, which is different from Example 1 in that the perfluoropolyether derivative is perfluoropolyether carboxylic acid.

[0101] For the waterborne fluorocarbon paints obtained in Examples 10 - 11 of the present application, adhesion and stain resistance tests were carried out, and the test results are shown in the following table.

[0102]

[0103] From the data analysis of the above table, it can be seen that the waterborne fluorocarbon paints obtained in Examples 1, 10, and 11 have an adhesion as high as 12.8 - 13.5 MPa and a decrease rate of the reflection coefficient as low as 3.5 - 3.7%. This shows that in the total raw materials for the preparation of the waterborne fluorocarbon paint of the present application, when the perfluoropolyether derivative is perfluoropolyether carboxylic acid or perfluoropolyether carboxylate, the obtained waterborne fluorocarbon paint has high adhesion and stain resistance.

[0104] Examples 12 - 14

[0105] A waterborne fluorocarbon paint, which is different from Example 1 in that the polyetheramine is a modified polyetheramine, and the modified polyetheramine is prepared from Preparation Examples 2 - 4 respectively.

[0106] For the waterborne fluorocarbon paints obtained in Examples 12 - 14 of the present application, adhesion and surface drying time tests were carried out, and the test results are shown in the following table.

[0107]

[0108] By analyzing the data in the above table, it can be seen that for the waterborne fluorocarbon paints obtained in Examples 1, 12, and 13, the adhesion force is as high as 11.5 - 13.5 MPa, and the surface drying time is as low as 0.35 - 0.45 h. This shows that in the total raw materials for preparing the waterborne fluorocarbon paint in this application, when the weight ratio of polyetheramine to epoxy group silane in the modified polyetheramine is 1:(0.2 - 0.4), the obtained waterborne fluorocarbon paint has high adhesion force and short surface drying time.

[0109] By comparing Example 1 with Example 14, it can be seen that compared with Example 14, Example 1 has higher adhesion force and shorter surface drying time. This shows that in the total raw materials for preparing the waterborne fluorocarbon paint in this application, modifying the monoamine polyetheramine can improve the adhesion force of the waterborne fluorocarbon paint and reduce the surface drying time. The reason may be that the waterborne fluorocarbon paint obtained by modifying the monoamine polyetheramine with epoxy group silane has good fluidity, which is convenient for wetting the substrate, thus improving the adhesion force.

[0110] At the same time, in this application, when the epoxy group silane in Example 1 is one or more of 3-aminopropylmethyldiethoxysilane, 3-glycidoxypropyltrimethoxysilane, and 3-glycidoxypropylmethyldimethoxysilane, the obtained waterborne fluorocarbon paint has the same performance as that of Example 1. Therefore, in this application, Example 1 only takes 3-aminopropylmethyldiethoxysilane as an epoxy group silane as a brief illustration, but it does not affect the application of other types of epoxy group silanes claimed in this application.

[0111] Example 15

[0112] A waterborne fluorocarbon paint, which is different from Example 1 in that the polyetheramine is polyetheramine CAM-2070, which is a monoamine based on the copolymer main chain.

[0113] For the waterborne fluorocarbon paint obtained in Example 15 of this application, tests on adhesion force, surface drying time, wet heat cold cycle resistance, and stain resistance were carried out, and the test results are shown in the following table.

[0114]

[0115] By analyzing the data in the above table, it can be seen that compared with Example 15, Example 1 has higher adhesion force, shorter surface drying time, more wet heat cold cycle times, and lower reflection coefficient decline rate. This shows that in the total raw materials for preparing the waterborne fluorocarbon paint in this application, modifying the polyetheramine can improve the adhesion force of the waterborne fluorocarbon paint, reduce the surface drying time, and improve the chemical resistance.

[0116] Comparative Example

[0117] Comparative Example 1

[0118] An aqueous fluorocarbon paint, which is different from that of Example 1 in that a fluorosurfactant PolyFox PF-154N of equal weight is used to replace the perfluoropolyether derivative.

[0119] Comparative Example 2

[0120] An aqueous fluorocarbon paint, which is different from that of Example 1 in that heptafluorobutyric acid of equal weight is used to replace the perfluoropolyether derivative.

[0121] Comparative Example 3

[0122] An aqueous fluorocarbon paint, which is different from that of Example 1 in that the addition amount of polyetheramine is 0.

[0123] The adhesion, surface drying time, wet heat cold cycle resistance, acid rain resistance, alkali resistance, water resistance, washability and stain resistance of the aqueous fluorocarbon paints obtained in Examples 12-15 of the present application were detected, and the detection results are shown in the following table.

[0124]

[0125]

[0126] It can be seen from the data analysis of the above table that compared with Comparative Examples 1, 2, and 3, Example 1 has higher adhesion, shorter surface drying time, more times of wet heat cold cycle resistance, longer acid rain resistance, alkali resistance and water resistance time, better stain resistance performance, and more times of washability. This shows that in the total raw materials for the preparation of the aqueous fluorocarbon paint of the present application, crosslinking and curing are carried out using perfluoropolyether carboxylate, polyetheramine, aqueous fluorinated acrylic emulsion, and isocyanate curing agent, and the obtained aqueous fluorocarbon paint has high adhesion, short surface drying time, and excellent chemical resistance.

[0127] This specific embodiment is only an explanation of the present application, and it does not limit the present application. Those skilled in the art can make modifications to this embodiment without creative contributions according to needs after reading this specification, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. An aqueous fluorocarbon paint, characterized in that, It includes Component A and Component B; Component A includes components in the following parts by weight: 30 - 60 parts of aqueous fluorinated acrylic emulsion; 15 - 20 parts of filler; 4 - 8 parts of polyetheramine; 10 - 15 parts of water; Component B includes components in the following parts by weight: 20 - 40 parts of isocyanate curing agent; 5 - 10 parts of perfluoropolyether derivative; In the said aqueous fluorocarbon paint, the weight ratio of the aqueous fluorinated acrylic emulsion to the perfluoropolyether derivative is 1:(0.14 - 0.19); The said perfluoropolyether derivative is perfluoropolyether carboxylate; The molecular weight of the said perfluoropolyether derivative is 2000 - 4000; The said perfluoropolyether carboxylate is one or both of sodium perfluoropolyether carboxylate and ammonium perfluoropolyether carboxylate.

2. The waterborne fluorocarbon paint according to claim 1, wherein The said polyetheramine is modified polyetheramine, and the preparation method of the modified polyetheramine is: stir and mix polyetheramine and epoxy group silane to obtain modified polyetheramine.

3. The waterborne fluorocarbon paint according to claim 2, characterized in that, In the preparation method of the said modified polyetheramine, the weight ratio of polyetheramine to epoxy group silane is 1:(0.2 - 0.4).

4. The waterborne fluorocarbon paint according to claim 2, wherein, The said epoxy group silane is one or more of 3 - glycidoxypropyltriethoxysilane, 3 - glycidoxypropyltrimethoxysilane and 3 - glycidoxypropylmethyldimethoxysilane.

5. The waterborne fluorocarbon paint according to claim 2, characterized in that, The said polyetheramine is monohydric polyetheramine.

6. The preparation method of the aqueous fluorocarbon paint according to any one of claims 1-5, characterized in that, It includes the following preparation steps: S1: Mix the aqueous fluorinated acrylic emulsion, filler, water and polyetheramine to obtain Component A; S2: Mix the isocyanate curing agent and the perfluoropolyether derivative to obtain Component B; S3: Mix Component A and Component B to obtain the aqueous fluorocarbon paint.

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