Wood water-based light-aging-resistant coating as well as preparation method and application thereof

Abstract

The invention discloses a wood water-based light-aging-resistant coating and a preparation method and application thereof, and the wood water-based light-aging-resistant coating comprises the following components in parts by mass: 10-75 parts of polyurethane acrylic resin, 0.5-2.5 parts of benzotriazole, 0.5-2.5 parts of sebacic acid bis (1, 2, 2, 6, 7-tetramethyl-1, 3-pentanedione), 0.5-1.5 parts of a curing agent, 0.5-1.5 parts of a curing agent, 0.5-1.5 parts of a curing agent, 0.5-1.5 The paint is prepared from the following components in parts by weight: 0.5 to 1.5 parts of 2, 2, 6, 6-pentamethyl-4-hydroxypiperidine) ester, 0.5 to 1.5 parts of cyclohexane, 0 to 1.5 parts of matting powder, 0 to 1.5 parts of polyoxyethylene sorbitan monooleate, and 0 to 1.5 parts of sorbitan palmitate; 0-3 parts of absolute ethyl alcohol and 10-80 parts of purified water. The wood water-based photoaging-resistant coating prepared by the invention can effectively improve the outdoor photoaging resistance of wood, and meanwhile, aggregation of organic phase microparticles can be prevented in the preparation process, so that a stable emulsion is obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of light-resistant aging materials, and specifically relates to a waterborne light-resistant aging coating for wood, a preparation method thereof, and an application thereof. Background Art

[0002] As a natural and environmentally friendly biomass material, wood has the advantages of strong renewability, beautiful texture, and high strength-to-weight ratio. However, during outdoor use, wood is affected by the combined action of environmental factors such as ultraviolet light, moisture, and oxygen, resulting in easy photo-degradation on the material surface. This phenomenon not only seriously affects the surface physical and chemical properties of the material, but also weakens the mechanical properties of the material to a certain extent. After the surface layer of wood is photo-degraded, microorganisms are more likely to invade its internal microstructure, thereby accelerating the microbial degradation process of the material. The photo-degradation problem greatly limits the application breadth and depth of wood, and significantly shortens the service life of wood products in outdoor environments. Therefore, it is urgent and necessary to carry out research on wood light protection to reduce the negative effects of ultraviolet light on wood substrates and coatings. The waterborne ultraviolet shielding coating using "water" as the dispersion medium can not only effectively reduce the emission of volatile organic compounds (VOCs) and reduce environmental pollution caused by waste, but in the waterborne ultraviolet barrier system, how to uniformly disperse the ultraviolet absorber in the organic phase in the waterborne solvent is the key to the research and development of light-resistant aging waterborne coatings. Summary of the Invention

[0003] The purpose of the present invention is to provide a waterborne light-resistant aging coating for wood, a preparation method thereof, and an application thereof. The waterborne light-resistant aging coating for wood prepared by the present invention can effectively improve the outdoor light-resistant aging performance of wood, and at the same time prevent the aggregation of organic phase microparticles during the preparation process, thereby obtaining a stable emulsion.

[0004] The technical solution of the present invention: A waterborne light-resistant aging coating for wood includes the following components by mass: 10 - 75 parts of polyurethane acrylate resin; 0.5 - 2.5 parts of benzotriazole, 0.5 - 1.5 parts of bis(1,2,2,6,6-pentamethyl-4-hydroxypiperidine) sebacate, 0.5 - 1.5 parts of cyclohexane, 0 - 1.5 parts of matting powder, 0 - 1.5 parts of polyoxyethylene sorbitan monooleate, 0 - 1.5 parts of sorbitan palmitate; 0 - 3 parts of absolute ethanol, 10 - 80 parts of pure water.

[0005] The above-mentioned waterborne light-resistant aging coating for wood comprises the following components by mass parts: 30-60 parts of polyurethane acrylate resin; 1-2 parts of benzotriazole, 1-2 parts of bis(1,2,2,6,6-pentamethyl-4-hydroxypiperidine) sebacate, 0.8-1.2 parts of cyclohexane, 0-1 part of matting powder, 0-1 part of polyoxyethylene sorbitan monooleate, 0-1 part of sorbitan palmitate; 0-2 parts of absolute ethanol, 30-60 parts of pure water.

[0006] The aforementioned waterborne light-resistant aging coating for wood comprises the following components by mass parts: 45 parts of polyurethane acrylate resin; 1.5 parts of benzotriazole, 1.5 parts of bis(1,2,2,6,6-pentamethyl-4-hydroxypiperidine) sebacate, 1 part of cyclohexane, 0.5 part of matting powder, 0.5 part of polyoxyethylene sorbitan monooleate, 0.5 part of sorbitan palmitate; 1 part of absolute ethanol, 50 parts of pure water.

[0007] The preparation method of the aforementioned waterborne light-resistant aging coating for wood comprises the following steps:

[0008] Step 1: Add benzotriazole, bis(1,2,2,6,6-pentamethyl-4-hydroxypiperidine) sebacate, cyclohexane, matting powder, polyoxyethylene sorbitan monooleate, sorbitan palmitate, absolute ethanol and pure water into a container, and then stir it.

[0009] Step 2: Add polyurethane acrylate resin into the container, stir it, and adjust the pH value to 4-9 to obtain the finished product.

[0010] In the preparation method of the aforementioned waterborne light-resistant aging coating for wood, in Step 1, the stirring speed is 100-10000 r / min, and the stirring time is 10-30 min.

[0011] In the preparation method of the aforementioned waterborne light-resistant aging coating for wood, in Step 2, the stirring speed is 100-10000 r / min, and the stirring time is 10-60 min.

[0012] An application of a waterborne light-resistant aging coating for wood, wherein the waterborne light-resistant aging coating for wood is applied to the surfaces of wood and its products.

[0013] In the aforementioned application, the coating amount of the waterborne light-resistant aging coating for wood is 20-200 g per square meter, and the total content of benzotriazole and bis(1,2,2,6,6-pentamethyl-4-hydroxypiperidine) sebacate in each square meter is 1-5 g.

[0014] Compared with the prior art, the present invention uses benzotriazole as the ultraviolet absorption functional factor in the organic phase of the coating, and bis(1,2,2,6,6-pentamethyl-4-hydroxypiperidine) sebacate as the light stabilizer. By using the emulsification technology, the organic phase such as the functional factor and the light stabilizer is highly dispersed in the aqueous phase, thereby preventing the aggregation of organic phase microparticles, and further enabling the ultraviolet absorber in the organic phase to be uniformly dispersed in the aqueous solvent, thus obtaining a stable emulsion. Then, a light-resistant aging waterborne coating is prepared therefrom. The light-resistant aging waterborne coating prepared by the present invention can effectively improve the outdoor light-resistant aging performance of wood, and has a high light color fastness, and can further improve the stability of the chromaticity, gloss, surface chemistry and other structures of wood. Description of the Drawings

[0015] Figure 1 It is a graph showing the stability test results of the emulsion after standing for 72 hours;

[0016] Figure 2 It is a Tyndall effect test graph of the wood waterborne light-resistant aging coating in Example 6;

[0017] Figure 3 It is a process graph of constructing an ultraviolet barrier on the surface of quartz glass;

[0018] Figure 4 It is a graph comparing the absorbance of Example 6 and a common coating. Detailed Embodiments

[0019] The present invention will be further described below in conjunction with the drawings and embodiments, but it shall not be used as a basis for limiting the present invention.

[0020] Example 1: A wood waterborne light-resistant aging coating, comprising the following components by mass: 60 g of polyurethane acrylate resin; 2.5 g of benzotriazole, 1 g of bis(1,2,2,6,6-pentamethyl-4-hydroxypiperidine) sebacate, 1.5 g of cyclohexane, 70 g of pure water; in this example, the benzotriazole is 2'-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole;

[0021] The preparation method of the wood waterborne light-resistant aging coating is as follows:

[0022] Step 1: Add benzotriazole, bis(1,2,2,6,6-pentamethyl-4-hydroxypiperidine) sebacate, cyclohexane and pure water into a container. Subsequently, stir it at a rotation speed of 8000 r / min for 15 min;

[0023] Step 2: Add polyurethane acrylate resin into the container, stir at a rotation speed of 5000 revolutions per minute for 30 minutes, and adjust the pH value of the solution to 4 - 9 with substances such as acetic acid and NaOH to obtain the finished product.

[0024] Example 2: A waterborne wood light - aging resistant coating, comprising the following components by mass: 30 g of polyurethane acrylate resin; 2.5 g of benzotriazole, 1.5 g of bis(1,2,2,6,6 - pentamethyl - 4 - hydroxypiperidinyl) sebacate, 1.5 g of cyclohexane, 0.5 g of matting powder, 1 g of polyoxyethylene sorbitan monooleate, 0.5 g of sorbitan palmitate, 0.5 g of absolute ethanol, 10 g of pure water; In this example, the benzotriazole is 2'-(2'-hydroxy - 3'-tert - butyl - 5'-methylphenyl)-5 - chlorobenzotriazole;

[0025] The preparation method of the waterborne wood light - aging resistant coating is as follows:

[0026] Step 1: Add benzotriazole, bis(1,2,2,6,6 - pentamethyl - 4 - hydroxypiperidinyl) sebacate, cyclohexane, matting powder, polyoxyethylene sorbitan monooleate, sorbitan palmitate, absolute ethanol and pure water into the container, and then stir at a rotation speed of 5000 revolutions per minute for 20 minutes;

[0027] Step 2: Add polyurethane acrylate resin into the container, stir at a rotation speed of 5000 revolutions per minute for 40 minutes, and adjust the pH value of the solution to 4 - 9 with substances such as acetic acid and NaOH to obtain the finished product.

[0028] Example 3: A waterborne wood light - aging resistant coating, comprising the following components by mass: 65 g of polyurethane acrylate resin; 1.5 g of benzotriazole, 1 g of bis(1,2,2,6,6 - pentamethyl - 4 - hydroxypiperidinyl) sebacate, 1 g of cyclohexane, 0.5 g of matting powder, 1.5 g of polyoxyethylene sorbitan monooleate, 1.5 g of sorbitan palmitate, 1 g of absolute ethanol, 80 g of pure water; In this example, the benzotriazole is 2'-(2'-hydroxy - 3'-tert - butyl - 5'-methylphenyl)-5 - chlorobenzotriazole;

[0029] The preparation method of the waterborne wood light - aging resistant coating is as follows:

[0030] Step 1: Add benzotriazole, bis(1,2,2,6,6 - pentamethyl - 4 - hydroxypiperidinyl) sebacate, cyclohexane, matting powder, polyoxyethylene sorbitan monooleate, sorbitan palmitate, absolute ethanol and pure water into the container, and then stir at a rotation speed of 9000 revolutions per minute for 10 minutes;

[0031] Step 2: Add polyurethane acrylate resin into the container, stir, with the stirring speed of 3000 revolutions per minute and the stirring time of 55 minutes, and adjust the pH value of the solution to 4 - 9 by substances such as acetic acid and NaOH to obtain the finished product.

[0032] Example 4: A waterborne wood light - aging resistant coating, comprising the following components by mass: 70 g of polyurethane acrylate resin, 2 g of benzotriazole, 0.5 g of bis(1,2,2,6,6 - pentamethyl - 4 - hydroxypiperidine) sebacate, 0.5 g of cyclohexane, 1.5 g of matting powder, 1 g of polyoxyethylene sorbitan monooleate, 1 g of sorbitan palmitate, 1 g of absolute ethanol, and 60 g of pure water; in this example, the benzotriazole is 2'-(2'-hydroxy - 3'-tert - butyl - 5'-methylphenyl)-5 - chlorobenzotriazole;

[0033] The preparation method of the waterborne wood light - aging resistant coating is as follows:

[0034] Step 1: Add benzotriazole, bis(1,2,2,6,6 - pentamethyl - 4 - hydroxypiperidine) sebacate, cyclohexane, matting powder, polyoxyethylene sorbitan monooleate, sorbitan palmitate, absolute ethanol, and pure water into the container, and then stir it with the stirring speed of 2000 revolutions per minute and the stirring time of 30 minutes;

[0035] Step 2: Add polyurethane acrylate resin into the container, stir, with the stirring speed of 6000 revolutions per minute and the stirring time of 30 minutes, and adjust the pH value of the solution to 4 - 9 by substances such as acetic acid and NaOH to obtain the finished product.

[0036] Example 5: A waterborne wood light - aging resistant coating, comprising the following components by mass: 45 g of polyurethane acrylate resin, 1.5 g of benzotriazole, 1.5 g of bis(1,2,2,6,6 - pentamethyl - 4 - hydroxypiperidine) sebacate, 1 g of cyclohexane, 0.5 g of matting powder, 0.5 g of polyoxyethylene sorbitan monooleate, 0.5 g of sorbitan palmitate, 1 g of absolute ethanol, and 50 g of pure water; in this example, the benzotriazole is 2'-(2'-hydroxy - 3'-tert - butyl - 5'-methylphenyl)-5 - chlorobenzotriazole;

[0037] The preparation method of the waterborne wood light - aging resistant coating is as follows:

[0038] Step 1: Add benzotriazole, bis(1,2,2,6,6-pentamethyl-4-hydroxypiperidinyl) sebacate, cyclohexane, matting powder, polyoxyethylene sorbitan monooleate, sorbitan palmitate, absolute ethanol, and pure water into a container. Subsequently, stir it at a rotation speed of 6000 rpm for 15 minutes.

[0039] Step 2: Add polyurethane acrylate resin into the container and stir it at a rotation speed of 5000 rpm for 25 minutes. Then adjust the pH value of the solution to 4 - 9 with substances such as acetic acid and NaOH to obtain the finished product.

[0040] Example 6: A waterborne wood light - resistant aging coating, comprising the following components by mass: 50 g of polyurethane acrylate resin, 2 g of benzotriazole, 2 g of bis(1,2,2,6,6 - pentamethyl - 4 - hydroxypiperidinyl) sebacate, 1 g of cyclohexane, 1 g of matting powder, 1 g of polyoxyethylene sorbitan monooleate, 2 g of sorbitan palmitate, 2 parts of absolute ethanol, and 50 g of pure water; In this example, the benzotriazole is 2'-(2'-hydroxy - 3'-tert - butyl - 5'-methylphenyl)-5 - chlorobenzotriazole.

[0041] The preparation method of the waterborne wood light - resistant aging coating is as follows:

[0042] Step 1: Add benzotriazole, bis(1,2,2,6,6 - pentamethyl - 4 - hydroxypiperidinyl) sebacate, cyclohexane, matting powder, polyoxyethylene sorbitan monooleate, sorbitan palmitate, absolute ethanol, and pure water into a container. Subsequently, stir it at a rotation speed of 5000 rpm for 20 minutes.

[0043] Step 2: Add polyurethane acrylate resin into the container and stir it at a rotation speed of 5000 rpm for 30 minutes. Then adjust the pH value of the solution to 4 - 9 with substances such as acetic acid and NaOH to obtain the finished product.

[0044] Example 7: Based on the waterborne wood light - resistant aging coatings prepared in Examples 1 - 6, the wood with dimensions of 25 mm×20 mm×5 mm is respectively coated. The coating amount of the waterborne wood light - resistant aging coating is 20 - 200 g per square meter. Adjust the contents of benzotriazole and bis(1,2,2,6,6 - pentamethyl - 4 - hydroxypiperidinyl) sebacate according to the coating amount so that the total content of benzotriazole and bis(1,2,2,6,6 - pentamethyl - 4 - hydroxypiperidinyl) sebacate in each square meter is about 3 g.

[0045] Then, the light-resistant aging wood prepared in Examples 1-6 was tested. After the test, the ultraviolet light shielding rate of the wood in each example was as high as over 99.9%. It can be seen that the waterborne light-resistant aging wood coating prepared by the present invention can effectively improve the outdoor light-resistant aging performance of wood.

[0046] Furthermore, the applicant also demonstrated the preparation process of the waterborne light-resistant aging wood coating in Example 6. Figure 1 It is the stability test result of the emulsion standing for 72 hours. The stability research result shows that after the waterborne hybrid emulsion stands for 72 hours, no obvious stratification, flocculation, demulsification and other phenomena are observed. This shows that the functional factors and light stabilizers are highly dispersed in the water phase, thus preventing the aggregation of organic phase microparticles, and further enabling the ultraviolet absorber in the organic phase to be uniformly dispersed in the waterborne solvent, thereby obtaining a stable emulsion.

[0047] Figure 2 It is the Tyndall effect test diagram of the waterborne light-resistant aging wood coating in Example 6, and its result shows a good Tyndall effect, which indicates that the ultraviolet absorber and light stabilizer are uniformly dispersed in the "water" phase in the form of particles with a suitable size in the range of 1-1000 nm. The Tyndall effect strongly reflects from the side that the emulsion dispersion system has good stability and uniformity.

[0048] As Figure 3 shown, a common waterborne polyurethane topcoat ( Figure 3 e in) and the waterborne light-resistant aging wood coating of the present invention ( Figure 3 d in) were applied on the surface of quartz glass to construct an ultraviolet barrier. Figure 4 It is the absorbance comparison between Example 6 and the common coating. It can be seen that the waterborne light-resistant aging coating of the present invention can shield 99.99% of ultraviolet rays, and the visible light transmittance is ≥80%, while the common waterborne polyurethane topcoat has a very low absorption rate of ultraviolet rays (in the 290-380 nm region) in sunlight (the ultraviolet light shielding rate is only 0-30%).

[0049] Finally, the present invention was applied to conduct a weather resistance study on the prepared wood products. A comparative study was carried out on the wood product materials prepared with common coatings and the wood products of the present invention. After accelerated aging, it was found that: the light fastness of the light-resistant aging wood materials was significantly improved. The following table shows the chromaticity parameters and total color difference of the light-resistant aging bamboo materials and the control samples before and after light aging:

[0050]

[0051] Among them: the light fastness ≥4 grades is qualified; among them, 5 grades is the highest grade.

[0052] In summary, the light-resistant aging waterborne coating prepared by the present invention can effectively improve the outdoor light-resistant aging performance of wood, and has a relatively high light color fastness. Furthermore, it can improve the stability of the chromaticity, glossiness, surface chemistry and other structures of wood. At the same time, during the preparation process of the light-resistant aging waterborne coating of the present invention, the aggregation of organic phase microparticles can be prevented, thereby obtaining a stable emulsion.

Claims

1. A water-based light-resistant aging paint for wood, characterized in that: The composition comprises the following components by mass: 10-75 parts of polyurethane acrylic resin, 0.5-2.5 parts of benzotriazole, 0.5-1.5 parts of bis(1,2,2,6,6-pentamethyl-4-hydroxypiperidinyl) sebacate, 0.5-1.5 parts of cyclohexane, 0-1.5 parts of matting powder, 0-1.5 parts of polyoxyethylene sorbitan monooleate, and 0-1.5 parts of sorbitan palmitate; 0-3 parts of anhydrous ethanol and 10-80 parts of purified water.

2. The water-based light-resistant paint for wood according to claim 1, characterized in that: The composition comprises the following components by mass: 30-60 parts of polyurethane acrylic resin, 1-2 parts of benzotriazole, 1-2 parts of bis(1,2,2,6,6-pentamethyl-4-hydroxypiperidinyl) sebacate, 0.8-1.2 parts of cyclohexane, 0-1 parts of matting powder, 0-1 parts of polyoxyethylene sorbitan monooleate, and 0-1 parts of sorbitan palmitate; 0-2 parts of anhydrous ethanol and 30-60 parts of purified water.

3. The water-based light-resistant paint for wood according to claim 1, characterized in that: The composition includes the following components by mass: 45 parts of polyurethane acrylic resin; 1.5 parts of benzotriazole, 1.5 parts of bis(1,2,2,6,6-pentamethyl-4-hydroxypiperidinyl) sebacate, 1 part of cyclohexane, 0.5 parts of matting powder, 0.5 parts of polyoxyethylene sorbitan monooleate, and 0.5 parts of sorbitan palmitate; 1 part of anhydrous ethanol and 50 parts of purified water.

4. The water-based light-resistant paint for wood according to claim 1, characterized in that: The polyoxyethylene sorbitan monooleate and sorbitan palmitate are emulsions, and cyclohexane is a continuous phase.

5. The method for preparing the water-based light-resistant aging coating for wood according to any one of claims 1 to 4, characterized in that: The steps include: Step 1, adding benzotriazole, bis(1,2,2,6,6-pentamethyl-4-hydroxypiperidinyl) sebacate, cyclohexane, matting powder, polyoxyethylene sorbitan monooleate, sorbitan palmitate, anhydrous ethanol and purified water into a container, and then stirring the container; Step 2: Add polyurethane acrylic resin into the container, stir, adjust the pH value to 4-9, adjust the ultrasonic treatment time and power to obtain the finished product.

6. The method for preparing the water-based light-resistant aging paint for wood according to claim 5, characterized in that: In step 1, the stirring speed is 100-10000 rpm, and the stirring time is 10-30 min.

7. The method for preparing the water-based light-resistant aging paint for wood according to claim 5, characterized in that: In step 2, the stirring speed is 100-10000 rpm, and the stirring time is 10-60 min.

8. The method for preparing the water-based light-resistant aging paint for wood according to claim 5, characterized in that: In step 2, the ultrasonic treatment time is 0-2h, and the ultrasonic power is 100-1000 watts.

9. An application of a water-based light-resistant aging coating for wood, characterized in that: The water-based light-resistant and aging-resistant paint for wood is applied to the surface of wood and its products.

10. The use according to claim 9, characterized in that: The coating amount of the water-based light-resistant aging paint for wood is 20-200 g / m2, wherein the total content of benzotriazole and bis(1,2,2,6,6-pentamethyl-4-hydroxypiperidinyl) sebacate is 1-5 g per m2.

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