A high weather-resistant alkyd protective coating and its preparation method

Abstract

This invention relates to the field of coating technology, and proposes a high weather-resistant alkyd protective coating and its preparation method. The alkyd protective coating comprises the following components in parts by weight: 45-55 parts alkyd resin, 20-42 parts methylphenyl silicone resin, 10-25 parts carbon nanotubes, 1-2 parts dispersant, 0.5-1.5 parts anti-settling agent, 1-2 parts drying agent, and 15-20 parts solvent. This technical solution solves the problems of poor weather resistance and flexibility caused by poor tensile properties, poor low-temperature flexibility, and poor aging resistance in related technologies of alkyd protective coatings.

Description

Technical Field

[0001] This invention relates to the field of coating technology, specifically to a high weather-resistant alkyd protective coating and its preparation method. Background Technology

[0002] Alkyd coatings, also known as alkyd resin coatings, are a type of coating with alkyd resin as the main component. Alkyd coatings offer numerous advantages, including excellent adhesion to various substrates, ensuring a tight bond between the coating and the substrate. They also exhibit good workability, are easy to apply, and have low environmental requirements. Alkyd coatings are widely used in various fields, including industrial corrosion protection, building decoration, and transportation. For example, they play a vital role in steel products, chemical equipment, marine engineering equipment, wood decoration, floor coating, automobiles, trains, and ships. Despite these advantages, alkyd coatings still have drawbacks. Existing alkyd coatings do not perform ideally in terms of tensile properties, low-temperature flexibility, and aging resistance, resulting in poor overall weather resistance and flexibility. Therefore, developing an alkyd protective coating with good tensile properties, low-temperature flexibility, and excellent aging resistance is of great significance. Summary of the Invention

[0003] This invention proposes a high weather-resistant alkyd protective coating and its preparation method, which solves the problems of poor weather resistance and flexibility caused by poor tensile properties, poor low-temperature flexibility, and poor aging resistance of alkyd protective coatings in related technologies.

[0004] The technical solution of the present invention is as follows:

[0005] This invention proposes a highly weather-resistant alkyd protective coating, comprising the following components in parts by weight:

[0006] The mixture contains 45-55 parts alkyd resin, 20-42 parts methylphenyl silicone resin, 10-25 parts carbon nanotubes, 1-2 parts dispersant, 0.5-1.5 parts anti-settling agent, 1-2 parts drying agent, and 15-20 parts solvent.

[0007] As a further technical solution, the weight ratio of the methylphenyl silicone resin to the carbon nanotubes is 3~5:3.

[0008] When the weight ratio of methylphenyl silicone resin to carbon nanotubes is 3~5:3, the tensile properties and aging resistance of alkyd protective coatings can be further improved, thereby further enhancing their weather resistance.

[0009] As a further technical solution, the carbon nanotubes include single-walled carbon nanotubes and multi-walled carbon nanotubes.

[0010] When carbon nanotubes include single-walled carbon nanotubes and multi-walled carbon nanotubes, the synergistic effect of the two types of carbon nanotubes can further improve the tensile properties and aging resistance of alkyd protective coatings, thereby further improving their weather resistance.

[0011] As a further technical solution, the weight ratio of the single-walled carbon nanotubes to the multi-walled carbon nanotubes is 1~3:1.

[0012] When the weight ratio of single-walled carbon nanotubes to multi-walled carbon nanotubes is 1 to 3:1, the tensile properties and aging resistance of alkyd protective coatings can be further improved, thereby further enhancing their weather resistance.

[0013] As a further technical solution, the carbon nanotubes are modified carbon nanotubes, which are obtained by modifying carbon nanotubes with carboxymethyl chitosan and styrene-maleic anhydride copolymer.

[0014] Surface modification of carbon nanotubes using carboxymethyl chitosan and styrene-maleic anhydride copolymers improves the dispersibility of carbon nanotubes and enhances their effective bonding with alkyd resins and methylphenyl silicone resins. This further improves the internal structural stability of alkyd protective coatings, thereby enhancing their tensile properties and aging resistance, and ultimately improving their weather resistance.

[0015] As a further technical solution, the weight ratio of the carbon nanotubes, carboxymethyl chitosan, and styrene-maleic anhydride copolymer is 10~22:1:1.

[0016] When the weight ratio of carbon nanotubes, carboxymethyl chitosan, and styrene-maleic anhydride copolymer is 10~22:1:1, the tensile properties and aging resistance of alkyd protective coatings can be further improved, thereby further enhancing their weather resistance.

[0017] As a further technical solution, the preparation method of the modified carbon nanotubes includes the following steps:

[0018] The carboxymethyl chitosan was dissolved in water to obtain a carboxymethyl chitosan solution. Carbon nanotubes were added to the carboxymethyl chitosan solution and stirred to obtain a premix. The styrene-maleic anhydride copolymer was added to the premix, stirred, concentrated, and dried to obtain the modified carbon nanotubes.

[0019] As a further technical solution, the mass fraction of the carboxymethyl chitosan solution is 5%~8%.

[0020] As a further technical solution, the dispersant is one or more of sodium tripolyphosphate, polyvinyl alcohol, and sodium oleate; the anti-settling agent is one or two of organic bentonite and fumed silica; the drying agent is one or more of manganese isooctanoate, cobalt naphthenate, and sodium linoleate; and the solvent is 200# solvent oil.

[0021] This invention also proposes a method for preparing a high weather-resistant alkyd protective coating, comprising the following steps:

[0022] S1. Except for carbon nanotubes, anti-settling agent and drying agent, mix the remaining components and stir to obtain a mixed solution;

[0023] S2. Add the carbon nanotubes, the anti-settling agent and the drying agent to the mixed solution and stir to obtain an alkyd protective coating.

[0024] As a further technical solution, in step S1, the stirring time is 40-80 minutes; in step S2, the stirring time is 20-30 minutes.

[0025] This invention also proposes the application of the high weather-resistant alkyd protective coating or the alkyd protective coating prepared by the aforementioned method in the protection of metal surfaces.

[0026] The working principle and beneficial effects of this invention are as follows:

[0027] In this invention, the alkyd protective coating includes methylphenyl silicone resin and carbon nanotubes. Through the effective combination of methylphenyl silicone resin and carbon nanotubes, the internal structural stability of the alkyd protective coating can be improved, thereby improving the tensile properties and aging resistance of the alkyd protective coating. At the same time, it also helps to improve the low-temperature flexibility of the coating, thereby improving its weather resistance and flexibility. Detailed Implementation

[0028] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0029] In the following examples and comparative examples, the alkyd resin is model E1301-6D; the methyl phenyl silicone resin is model SH-9601; the single-walled carbon nanotubes have a diameter of 2 nm and are model CNT100; the multi-walled carbon nanotubes have a diameter of 10 nm and are model LBW-5585; the carboxymethyl chitosan has a CAS number of 83512-85-0; the styrene-maleic anhydride copolymer is model SMA 1000P; the polyvinyl alcohol is model PVA-105; and the organobentonite is model HFGEL-40.

[0030] Example 1

[0031] A highly weather-resistant alkyd protective coating comprises the following components in parts by weight:

[0032] 45 parts alkyd resin, 20 parts methyl phenyl silicone resin, 10 parts single-walled carbon nanotubes, 1 part polyvinyl alcohol, 0.5 parts organobentonite, 1 part sodium linoleate, and 15 parts 200# solvent oil.

[0033] Its preparation method includes the following steps:

[0034] S1. Except for carbon nanotubes, organobentonite and sodium linoleate, mix the remaining components and stir for 40 minutes to obtain a mixed solution.

[0035] S2. Add single-walled carbon nanotubes, organic bentonite and sodium linoleate to the mixed solution and stir for 20 minutes to obtain alkyd protective coating.

[0036] Example 2

[0037] A highly weather-resistant alkyd protective coating comprises the following components in parts by weight:

[0038] 50 parts alkyd resin, 32 parts methyl phenyl silicone resin, 16 parts single-walled carbon nanotubes, 1.5 parts polyvinyl alcohol, 1 part organobentonite, 1.5 parts sodium linoleate, and 18 parts 200# solvent oil;

[0039] Its preparation method includes the following steps:

[0040] S1. Except for carbon nanotubes, organobentonite and sodium linoleate, mix the remaining components and stir for 60 minutes to obtain a mixed solution.

[0041] S2. Add single-walled carbon nanotubes, organobentonite and sodium linoleate to the mixed solution and stir for 25 minutes to obtain alkyd protective coating.

[0042] Example 3

[0043] A highly weather-resistant alkyd protective coating comprises the following components in parts by weight:

[0044] 55 parts alkyd resin, 42 parts methyl phenyl silicone resin, 25 parts single-walled carbon nanotubes, 2 parts polyvinyl alcohol, 1.5 parts organobentonite, 2 parts sodium linoleate, and 20 parts 200# solvent oil.

[0045] Its preparation method includes the following steps:

[0046] S1. Except for carbon nanotubes, organobentonite and sodium linoleate, mix the remaining components and stir for 80 minutes to obtain a mixed solution.

[0047] S2. Add single-walled carbon nanotubes, organobentonite and sodium linoleate to the mixed solution and stir for 30 minutes to obtain alkyd protective coating.

[0048] Example 4

[0049] The only difference between this embodiment and Embodiment 2 is that the amount of methylphenyl silicone resin added is 23 parts, and the amount of single-walled carbon nanotubes added is 25 parts.

[0050] Example 5

[0051] The only difference between this embodiment and Embodiment 2 is that the amount of methylphenyl silicone resin added is 30 parts, and the amount of single-walled carbon nanotubes added is 18 parts.

[0052] Example 6

[0053] The only difference between this embodiment and Embodiment 2 is that 24 parts of methylphenyl silicone resin and 24 parts of single-walled carbon nanotubes were added.

[0054] Example 7

[0055] The only difference between this embodiment and Embodiment 6 is that 24 parts of single-walled carbon nanotubes are replaced with 24 parts of multi-walled carbon nanotubes.

[0056] Example 8

[0057] The only difference between this embodiment and Embodiment 6 is that the 24 carbon nanotubes added include 10 single-walled carbon nanotubes and 14 multi-walled carbon nanotubes.

[0058] Example 9

[0059] The only difference between this embodiment and Embodiment 6 is that the 24 carbon nanotubes added include 20 single-walled carbon nanotubes and 4 multi-walled carbon nanotubes.

[0060] Example 10

[0061] The only difference between this embodiment and Embodiment 6 is that the 24 carbon nanotubes added include 18 single-walled carbon nanotubes and 6 multi-walled carbon nanotubes.

[0062] Example 11

[0063] The only difference between this embodiment and Embodiment 6 is that the 24 carbon nanotubes added include 12 single-walled carbon nanotubes and 12 multi-walled carbon nanotubes.

[0064] Example 12

[0065] The only difference between this embodiment and Example 11 is that the carbon nanotubes are modified carbon nanotubes. These modified carbon nanotubes are obtained by modifying carbon nanotubes with carboxymethyl chitosan and styrene-maleic anhydride copolymer. The preparation method of the modified carbon nanotubes includes the following steps:

[0066] 2.5 parts of carboxymethyl chitosan were dissolved in water to obtain a 6% carboxymethyl chitosan solution. 19 parts of carbon nanotubes (9.5 parts of single-walled carbon nanotubes and 9.5 parts of multi-walled carbon nanotubes) were added to the 6% carboxymethyl chitosan solution and stirred to obtain a premix. 2.5 parts of styrene-maleic anhydride copolymer were added to the premix, stirred, concentrated, and dried to obtain modified carbon nanotubes.

[0067] Example 13

[0068] The only difference between this embodiment and Embodiment 12 is that the amount of carbon nanotubes added is 23 parts (11.5 parts of single-walled carbon nanotubes and 11.5 parts of multi-walled carbon nanotubes), the amount of carboxymethyl chitosan added is 0.5 parts, and the amount of styrene-maleic anhydride copolymer added is 0.5 parts.

[0069] Example 14

[0070] The only difference between this embodiment and Embodiment 12 is that the amount of carbon nanotubes added is 20 parts (10 parts of single-walled carbon nanotubes and 10 parts of multi-walled carbon nanotubes), the amount of carboxymethyl chitosan added is 2 parts, and the amount of styrene-maleic anhydride copolymer added is 2 parts.

[0071] Example 15

[0072] The only difference between this embodiment and Embodiment 12 is that the amount of carbon nanotubes added is 22 parts (11 parts of single-walled carbon nanotubes and 11 parts of multi-walled carbon nanotubes), the amount of carboxymethyl chitosan added is 1 part, and the amount of styrene-maleic anhydride copolymer added is 1 part.

[0073] Comparative Example 1

[0074] The only difference between this comparative example and Example 1 is that single-walled carbon nanotubes were not added, and the amount of methylphenyl silicone resin added was 30 parts.

[0075] Comparative Example 2

[0076] The only difference between this comparative example and Example 1 is that methylphenyl silicone resin was not added, and 30 parts of single-walled carbon nanotubes were added.

[0077] Comparative Example 3

[0078] The only difference between this comparative example and Example 1 is that methylphenyl silicone resin and single-walled carbon nanotubes were not added.

[0079] Experimental Example 1

[0080] The alkyd protective coatings of Examples 1-3 and Comparative Examples 1-3 were subjected to low-temperature flexibility tests according to the test methods in GB / T 16777-2008 "Test Methods for Waterproof Coatings for Buildings". The low-temperature flexibility test was conducted using a round bar with a diameter of 10 mm. After the specimens were removed immediately, the surface of the specimens was observed with the naked eye for cracks or fractures. The test results are shown in Table 1 below.

[0081] Experiment Example 2

[0082] The alkyd protective coatings of Examples 1-15 and Comparative Examples 1-3 were subjected to the following performance tests according to GB / T 16777-2008 "Test Methods for Waterproof Coatings for Buildings":

[0083] Tensile properties: After the alkyd protective coating was prepared into a film, dumbbell-shaped specimens were cut and subjected to tensile property tests without treatment; the film thickness was 1.5 mm and the tensile speed was 200 mm / min.

[0084] Aging resistance: After the alkyd protective coating is prepared, an artificial climate aging test is conducted. The tensile strength after the artificial climate aging test is determined according to the tensile property test method described above. The tensile property retention rate after the artificial climate aging test is calculated using the following formula: Tensile property retention rate after artificial climate aging test = Tensile strength after artificial climate aging test / Tensile strength before test × 100% (the result is retained to one decimal place). The test results are shown in Table 2 below.

[0085] Table 1 Test Results

[0086]

[0087] Table 2 Test Results

[0088]

[0089] In Table 1, compared with Comparative Examples 1 to 3, after the alkyd protective coating of Example 1 was subjected to a low-temperature flexibility test, the surface of the coating specimen of the alkyd protective coating showed no cracks. This indicates that when the alkyd protective coating includes methylphenyl silicone resin and carbon nanotubes, the methylphenyl silicone resin and carbon nanotubes have a synergistic effect. Through the effective combination of the two, it helps to improve the low-temperature flexibility of the coating, thereby improving its flexibility.

[0090] In Table 2, compared with Comparative Examples 1-3, the tensile strength and tensile property retention rate of Example 1 in the artificial climate aging test were significantly improved. This indicates that when alkyd protective coatings include methylphenyl silicone resin and carbon nanotubes, methylphenyl silicone resin and carbon nanotubes have a synergistic effect. Through the effective combination of the two, the tensile properties and aging resistance of alkyd protective coatings are improved, thereby improving their weather resistance.

[0091] Compared with Examples 2 and 4, Examples 5 and 6 show improved tensile strength and retention rates of tensile properties in artificial weathering tests, indicating that a weight ratio of methylphenyl silicone resin to carbon nanotubes of 3-5:3 can further improve the tensile properties and aging resistance of alkyd protective coatings, thereby further enhancing their weather resistance. Compared with Examples 6 and 7, Examples 8-11 show improved tensile strength and retention rates of tensile properties in artificial weathering tests, indicating that when carbon nanotubes include single-walled and multi-walled carbon nanotubes, the synergistic effect of the two types of carbon nanotubes can further improve the tensile properties and aging resistance of alkyd protective coatings, thereby further enhancing their weather resistance. Compared with Examples 8 and 9, Examples 10-11 show improved tensile strength and retention rates of tensile properties in artificial weathering tests, indicating that a weight ratio of single-walled and multi-walled carbon nanotubes of 1-3:1 can further improve the tensile properties and aging resistance of alkyd protective coatings, thereby further enhancing their weather resistance. Compared to Example 11, Examples 12-15 showed improved tensile strength and retention rate of tensile properties in artificial weathering tests, indicating that surface modification of carbon nanotubes using carboxymethyl chitosan and styrene-maleic anhydride copolymer can further improve the tensile properties and aging resistance of alkyd protective coatings, thereby further enhancing their weather resistance. Compared to Examples 12-13, Examples 14-15 showed improved tensile strength and retention rate of tensile properties in artificial weathering tests, indicating that when the weight ratio of carbon nanotubes, carboxymethyl chitosan, and styrene-maleic anhydride copolymer is 10-22:1:1, the tensile properties and aging resistance of alkyd protective coatings can be further improved, thereby further enhancing their weather resistance.

[0092] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A highly weather-resistant alkyd protective coating, characterized in that, The components include the following parts by weight: Alkyd resin 45-55 parts, methyl phenyl silicone resin 20-42 parts, carbon nanotubes 10-25 parts, dispersant 1-2 parts, anti-settling agent 0.5-1.5 parts, drier 1-2 parts, solvent 15-20 parts; The weight ratio of the methylphenyl silicone resin to the carbon nanotubes is 3~5:3; The carbon nanotubes include single-walled carbon nanotubes and multi-walled carbon nanotubes with a weight ratio of 1 to 3:

1. The carbon nanotubes are modified carbon nanotubes, which are obtained by modifying carbon nanotubes with carboxymethyl chitosan and styrene-maleic anhydride copolymer. The weight ratio of the carbon nanotubes, carboxymethyl chitosan, and styrene-maleic anhydride copolymer is 10~22:1:1; The method for preparing the modified carbon nanotubes includes the following steps: The carboxymethyl chitosan was dissolved in water to obtain a carboxymethyl chitosan solution. Carbon nanotubes were added to the carboxymethyl chitosan solution and stirred to obtain a premix. The styrene-maleic anhydride copolymer was added to the premix, stirred, concentrated, and dried to obtain the modified carbon nanotubes.

2. The high weather-resistant alkyd protective coating according to claim 1, characterized in that, The dispersant is one or more of sodium tripolyphosphate, polyvinyl alcohol, and sodium oleate; the anti-settling agent is one or two of organic bentonite and fumed silica; the drying agent is one or more of manganese isooctanoate, cobalt naphthenate, and sodium linoleate; and the solvent is 200# solvent oil.

3. A method for preparing a high weather-resistant alkyd protective coating according to any one of claims 1 to 2, characterized in that, Includes the following steps: S1. Except for carbon nanotubes, anti-settling agent and drying agent, mix the remaining components and stir to obtain a mixed solution; S2. Add the carbon nanotubes, the anti-settling agent and the drying agent to the mixed solution and stir to obtain an alkyd protective coating.

4. The application of a high weather-resistant alkyd protective coating according to any one of claims 1 to 2 or an alkyd protective coating prepared by the preparation method according to claim 3 in the protection of metal surfaces.

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