High protection type water-based outdoor wood base-coat-in-one paint and preparation method thereof

Abstract

The application discloses a high-protection water-based outdoor wood one-coat paint and a preparation method thereof, and belongs to the field of paints. The method comprises the following steps: adding water-based acrylic resin and high-flexibility fluorine-containing acrylic emulsion into a paint mixing kettle and uniformly stirring; then adding dipropylene glycol methyl ether, dipropylene glycol butyl ether, a base material wetting agent, a defoaming agent, a scratch-resistant additive, and water into a batching kettle to obtain a dispersed mixed solution; mixing the dispersed mixed solution, modified nano cerium oxide-silicon nitride compound slurry and water-based titanium white paste again, adding micro-fine silica aerogel powder after mixing, adding isothiazolinone bactericide and tannin acid inhibitor after fine dispersion, mixing again, filtering the product after adjusting the system viscosity by adding an associated polyurethane thickening agent, and obtaining the high-protection water-based outdoor wood one-coat paint.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of water-based wood coatings, especially applied to outdoor and has high protective water-based wood basecoat paint and its preparation method. BACKGROUND

[0002] At present, water-based wood coatings as one of the important components of water-based coatings has been popularized in China, compared with oil-based paint, due to its excellent performance of ultra-low VOC, non-toxic and harmless, environment-friendly, has occupied a certain market in decoration and furniture field. In the field of outdoor wood, due to the porosity and hygroscopicity of wood body, it will absorb water from the air in the space with large temperature and humidity change, and expand and shrink easily when the temperature difference between day and night is large, which will cause the deformation and cracking of wood itself; The organic substances such as hemicellulose and lignin contained in wood can also provide a good living environment for insects, so that the wood is eroded. In addition, the sugar in wood fiber can also attract bacteria to erode wood and rot; In addition, the ultraviolet rays in light and dust in the air can also fade the natural color of wood in several years, and form a gray and black oxidation layer and dirt on the surface of wood.

[0003] Therefore, in addition to the need of decoration design, outdoor wood coatings also need to meet the requirements of good aging resistance, water resistance, self-cleaning, corrosion resistance and other requirements. The service life of ordinary water-based outdoor wood coatings on the market is basically 1-2 years, and after the above-mentioned period, the coating film will appear different degrees of cracking, loss of luster, mildew and yellowing and other maladies. Water-based acrylic coatings doped with fluorine have super aging resistance, excellent flexibility and self-cleaning function, which are very suitable for application in outdoor wood products, and have become a new research direction in the coating industry.

[0004] Compared with water-based two-component wood coatings, water-based single-component coatings are recognized by the majority of users due to their simple construction method, fast drying performance and high strength flexibility. However, the rigidity, wear resistance and water vapor shielding effect of the coating itself are also the difficult problems that need to be solved in the research direction. In addition, the complicated multi-layer coating not only has high construction cost, time-consuming and laborious, but also needs to adjust the construction time according to the weather change, which affects the construction efficiency; The single-layer coating film often has poor protective effect, which leads to malady of the coating film in later period. Therefore, it is very necessary to develop a water-based wood coating that can be used as basecoat and applied to outdoor for long time. Current research shows that using wear-resistant inorganic material coated rare earth oxide to modify water-based outdoor single-layer coating is one of the effective and feasible ways. SUMMARY

[0005] The application aims to provide a long-acting water-based wood primer and finish coating with high protection for outdoor use.

[0006] The application also aims to provide a preparation method of the above-mentioned water-based wood primer and finish coating for outdoor use.

[0007] The application can achieve the above-mentioned purposes through the following measures.

[0008] The application provides a high-protection water-based wood primer and finish coating for outdoor use, which is composed of the following components and weight parts.

[0009]

[0010] In some preferred technical solutions, the coating is composed of the following components and weight parts.

[0011]

[0012] In the technical solutions of the application, the water-based acrylic emulsion is one or more of the following: Wanhua Lacper 4570 water-based acrylic emulsion, Jiafeng Chemical JF1015 water-based core-shell structure acrylic emulsion, Lanke Road L-9130W water-based acrylic resin, and Ruyi Chemical RC-7209 water-based self-crosslinking pure acrylic emulsion.

[0013] In the technical solutions of the application, the high-flexibility fluorine-containing acrylic emulsion is one or more of the following: Donglu DF-02 core-shell structure fluorine-containing acrylic emulsion, Zhonglian Fuman FEM-101 self-crosslinking fluorocarbon emulsion, and Xun Da HD-830 self-crosslinking fluorosilicon propylene emulsion.

[0014] In the technical solutions of the application, the modified nano cerium oxide-silicon nitride composite slurry is prepared through the following steps.

[0015] S1: In a nitrogen-purged reactor, 100 parts by mass of nano cerium oxide powder is added, 20-30 parts by mass of silicon tetrachloride gas is introduced, and then ammonia gas is introduced and reacted at 1000-1500 DEG C for 3-5 hours; after the reaction is completed, the temperature is lowered to 100-200 DEG C, and the reaction is continued for 1-2 hours; wherein the molar ratio of NH3 and SiCl4 is 1.5-2:1;

[0016] Excess ammonia gas is added and the generated ammonium chloride is removed; the temperature is continuously raised to 600-800 DEG C and reacted for 4-6 hours to make the generated amorphous silicon nitride coated on the surface of the nano cerium oxide; finally, the nano cerium oxide-silicon nitride composite is obtained through centrifugation, washing, and vacuum drying;

[0017] S2:KH-560 silane coupling agent is prepared into a 20% ethanol solution at room temperature for 1h, and a proper amount of nano cerium oxide-silicon nitride composite powder is placed in the prepared solution and can be fully infiltrated, then acetone is added as a catalyst, ultrasonic dispersion is carried out for 0.5-1h, then stirring dispersion is carried out for 6-8h, and the modified nano cerium oxide-silicon nitride composite powder is obtained after filtration, cleaning with ethanol and drying.

[0018] S3:40-60 mass parts of the nano cerium oxide-silicon nitride composite powder treated by the coupling agent is placed in a paint kettle, 45-55 mass parts of deionized water, 0.5-3 mass parts of BYK-190 water-based wetting dispersant, 0.1-1 mass parts of Airex 904W defoaming agent and 0.5 mass parts of LXE bactericide are uniformly stirred, and then transferred into a sand mill for grinding to a fineness of ≤20um, so as to obtain the modified nano cerium oxide-silicon nitride composite slurry.

[0019] In the technical scheme of the present application: the substrate wetting agent is at least one of Di Guo Twin-4100, TEGO WET KL245, and BIK BYK-346; the defoaming agent is Airex 904W, FOAMEX 810, Airex 902W; the associative polyurethane thickening agent is one or more of Wanhua Vesmody U605, De Chen RHEOLATE 299, and German Ming Ling PUR40, Pu is Coadd TM U601.

[0020] In the technical scheme of the present application: the tannin inhibitor is American HALOX L-44; and the isothiazolinone bactericide is Dow Chemical LXE.

[0021] In the technical scheme of the present application: the anti-scratch aid is Glide 482, DOWSIL TM 211SAdditive, and Michaelmen ME 95535.S.

[0022] A preparation method of a high-protection water-based outdoor wood basecoat paint, characterized in that the steps of the method are as follows:

[0023] In the paint kettle, water-based acrylic emulsion and high flexibility fluorine-containing acrylic emulsion are added and stirred uniformly; then dipropylene glycol methyl ether, dipropylene glycol butyl ether, base wetting agent, defoaming agent, anti-scratch aid, water are added into the batching kettle and pre-dispersed at 800-1000 r / min for 0.5-1h to obtain the dispersed mixed liquid; the dispersed mixed liquid, modified nano cerium oxide-silicon nitride composite slurry and water-based titanium white paste are mixed again, after mixing, silica aerogel powder is added, and the dispersion is continued at 1000-1500 r / min for 0.5-1h, after the fineness dispersion is qualified, isothiazolinone bactericide and tannin acid inhibitor are added and mixed again, after mixing, the associated polyurethane thickening agent is added to adjust the system viscosity, and then the material is filtered to obtain the high protection type water-based outdoor wood bottom and surface integrated coating.

[0024] The beneficial effects of the present application are:

[0025] (1) The means of doping high flexibility fluorine-containing acrylic emulsion with acrylic resin: by mixing the fluorine resin with high flexibility in the water-based acrylic system with high cost performance, a skeleton with firm C-F bond is established, which has high bond energy and amazing chemical inertness, not only can the construction be carried out at low temperature, but also the product has excellent properties such as chemical resistance, weather resistance and stain resistance. In addition, the fluorine resin optimally gives the product super flexibility, so that the coating film can withstand the deformation pressure of wood due to thermal expansion and contraction under extremely cold and high temperature conditions, and its tensile strength has far exceeded that of similar products. (2) Modification of inorganic material coated rare earth oxide: silicon nitride has high hardness, wear resistance, good lubricity and low thermal conductivity, which can not only establish excellent rigidity and scratch resistance for outdoor coating, but also the heat transfer characteristics can also ensure that the wood in the coating does not easily expand and contract. The 4f electron structure of nano cerium oxide also has anti-aging ability and ultraviolet light shielding properties, and the introduction of nano cerium oxide can filter out most of the ultraviolet light in the 200-400nm region, thereby protecting the coating and wood from ultraviolet erosion. In addition, cerium oxide nanoparticles have excellent antibacterial and mildew-proof functions, based on the advantages of reversible valence state conversion and electrostatic interaction, they can cause permanent mechanical damage and extinction to mold, bacteria and viruses.

[0026] (3) The strategy of using silicon nitride to coat nano cerium oxide and coupling agent modification: coating can further improve the overall support and rigidity, increase the contact area and stability of the powder and liquid phase. But silicon nitride and nano cerium oxide belong to inorganic materials, the crystal structure is strong, the specific surface area is large, it is not easy to be dispersed and ground in water phase system, and it also has the defect of easy precipitation, therefore, the modification of coupling agent is an economic and optional way. The silane coupling agent can combine with the hydroxyl group of inorganic materials at one end, and condense, dehydrate and solidify under certain conditions to form covalent bond, thereby more conducive to the dispersion and stability of inorganic materials in organic polymer materials.(4) Using auxiliary new technology materials to strengthen the performance of coating film: the silica aerogel powder has the functions of superhydrophobic, heat insulation, flame retardant, gas purification and other aspects, and has the reinforcing effect on the suspension and thixotropic thickening of the coating in the tank due to its large specific surface area and high porosity structure, which can effectively prevent the sedimentation of the powder in the tank. The anti-scratch additive generally has good heat resistance and super strong lubricating effect, the particles of the additive can float and migrate to the outer surface of the coating film during the drying process of the coating film, and the addition of silicon nitride can improve the hardness and scratch resistance of the paint surface; at the same time, the anti-scratch additive also has excellent anti-fouling ability, and together with the fluorine-containing emulsion, it forms a double protection of the self-cleaning function of the coating film. Since the present application is designed as an outdoor bottom-coating paint which can directly contact with wood substrate, the tannin and pigment in wood can be dissolved with water in the coating layer, directly penetrate into the water-based paint film and be oxidized to change color, and the tannin itself also reacts with some metal complex ions in the coating to change color, therefore, the tannin inhibitor can effectively seal the tannin in the wood, has excellent barrier property and protects the color of the coating film from being damaged from inside. DETAILED DESCRIPTION

[0027] The application will be further described below in combination with examples, but the protection scope of the application is not limited thereto.

[0028] The water-based acrylic emulsion is one or more of Wanhua Lacper 4570 water-based acrylic emulsion (referred to as Lacper 4570), Jiafeng Chemical JF1015 water-based core-shell structure acrylic emulsion (referred to as JF1015), Lanke Road L-9130W water-based acrylic resin (referred to as L-9130W), and Rikao Chemical RC-7209 water-based self-crosslinking pure acrylic emulsion (referred to as RC-7209).

[0029] The high-flexibility fluorine-containing acrylic emulsion is one or more of Donglu DF-02 core-shell structure fluorine-containing acrylic fluorine emulsion (referred to as DF-02), Zhonglian Fuman FEM-101 self-crosslinking fluorocarbon emulsion (referred to as FEM-101), and Xun Da HD-830 self-crosslinking fluorosilicon propylene emulsion (referred to as HD-830).

[0030] The base material wetting agent is Digo at least one of Twin-4100, TEGO WET KL 245, BYK-346; the defoaming agent is Airex 904W, FOAMEX 810, Airex 902W; the associative polyurethane thickening agent is Wanhua Vesmody U605 (U605), Rheox RHEOLATE 299 (299), Germany Mingling PUR40 (PUR40), Puwei Coadd TM U601 (U601).

[0031] The tannin inhibitor is HALOX L-44; the isothiazolinone bactericide is Dow Chemical LXE.

[0032] The anti-scratch aid is Glide 482, DOWSIL TM 211S Additive, Michaelmen ME95535.S.

[0033] The purchase source of the silica aerogel powder includes but is not limited to the following website:

[0034] http: / / www.tianyi-nano.com.cn / Product / 3918521653.html

[0035] The purchase source of the water-based self-crosslinking pure acrylic emulsion of Sunrise Chemical RC-7209 includes but is not limited to the following website: http: / / www.sunrising.com.cn / d / file / p / rc-7209.pdf

[0036] The preparation steps of the water-based outdoor wood coatings of Examples 1-4 (see Table 1 for material ratio) and Comparative Examples 1-8 are as follows:

[0037] (1) Preparation of modified nano cerium oxide-silicon nitride composite slurry:

[0038] In a nitrogen-purged reactor, 100 parts by mass of nano cerium oxide powder was added, and after 25 parts by mass of silicon tetrachloride gas was introduced, ammonia gas was introduced. Among them, NH3: SiCl4 = 1.5:1 (molar ratio). Turn on the powder stirring, react at 1500℃ for 5h. Cool to 100℃, continue to react for 2h. Add excess ammonia gas, heat treatment of hydrogen chloride produced by reaction at 300℃. After 2h, cool to 100℃. Increase the temperature to remove the byproduct ammonium chloride of ammonia and hydrogen chloride. Continue to heat to 600℃ for 4h to make the generated amorphous silicon nitride coated on the surface of nano cerium oxide. After centrifugation, washing, vacuum drying at 50℃, nano cerium oxide-silicon nitride composite is obtained. Prepare a 20% ethanol solution of KH-560 silane coupling agent at room temperature for 1h, take the nano cerium oxide-silicon nitride composite powder and immerse it in the prepared solution, then add acetone as a catalyst, ultrasonic dispersion for 1h, then stirring dispersion for 8h, filter and clean with ethanol, and dry to obtain modified nano cerium oxide-silicon nitride composite powder.

[0039] Put 50 parts by mass of nano cerium oxide-silicon nitride composite powder treated by coupling agent into a paint kettle, add 48 parts by mass of deionized water, 1 part by mass of BYK-190 water-based wetting dispersant, 0.5 parts by mass of Airex904W defoamer and 0.5 parts by mass of LXE bactericide, stir evenly, then transfer to a sand mill to grind to a fineness of ≤20um, and obtain a 50% mass concentration of modified nano cerium oxide-silicon nitride composite slurry.

[0040] (2) Preparation of water-based outdoor wood base and surface one-coat paint:

[0041] Add water-based acrylic resin and high-flexibility fluorine-containing acrylic emulsion to the paint kettle and stir evenly; then add dipropylene glycol methyl ether, dipropylene glycol butyl ether, substrate wetting agent, defoamer, anti-scratch additive, water to the mixing kettle and pre-disperse at 800r / min for 1h to obtain a dispersed mixture; mix the dispersed mixture with modified nano cerium oxide-silicon nitride composite slurry and water-based titanium white paste again, add micro-fine silica aerogel powder after mixing, continue to disperse at 1000r / min for 0.5h, add isothiazolinone bactericide and tannin inhibitor after passing the fineness dispersion, mix again, and adjust the system viscosity by adding associated polyurethane thickener to obtain a high-protection water-based outdoor wood base and surface one-coat paint.

[0042] Table 1: Addition amount of materials in examples 1-4 (parts by mass)

[0043]

[0044]

[0045] Material proportions of Comparative Examples 1-8:

[0046] (1) Comparative Example 1

[0047] 25 parts by mass of the high-flexibility fluorine-containing acrylic emulsion DF-02 in Example 1 is replaced by 25 parts by mass of the water-based acrylic copolymer emulsion 4507, and the remaining material proportions are the same as in Example 1.

[0048] (2) Comparative Example 2

[0049] 30 parts by mass of the modified nano cerium oxide-silicon nitride composite slurry in Example 2 is replaced by 30 parts by mass of the water-based precipitated barium sulfate water slurry, and the remaining material proportions are the same as in Example 2.

[0050] (3) Comparative Example 3

[0051] 2 parts by mass of the microfine silica aerogel powder in Example 3 is replaced by 2 parts by mass of the organic bentonite, and the remaining material proportions are the same as in Example 3.

[0052] (4) Comparative Example 4

[0053] 0.5 parts by mass of the anti-scratch aid DOWSIL 211S and ME 95535.S in Example 4 is replaced by 0.5 parts by mass of the water-based leveling agent BYK-333, and the remaining material proportions are the same as in Example 4.

[0054] (5) Comparative Example 5

[0055] 2 parts by mass of the tannic acid inhibitor L-44 in Example 1 is replaced by 2 parts by mass of deionized water, and the remaining material proportions are the same as in Example 1.

[0056] (6) Comparative Example 6

[0057] 30 parts by mass of the modified nano cerium oxide-silicon nitride composite slurry in Example 2 is replaced by 28 parts by mass of deionized water and 2 parts by mass of the water-based ultraviolet light absorber, and the remaining material proportions are the same as in Example 2.

[0058] (7) Comparative Example 7

[0059] 25 parts by mass of the modified nano cerium oxide-silicon nitride composite slurry in Example 3 is replaced by 24 parts by mass of deionized water and 1 part by mass of the water-based dry film mildew inhibitor, and the remaining material proportions are the same as in Example 3.

[0060] (8) Comparative Example 8

[0061] ​The 20 parts by mass of modified nanometer cerium oxide-silicon nitride composite slurry in Example 4 was replaced by 20 parts by mass of nanometer cerium oxide slurry, and the rest of the material ratio was the same as in Example 4.

[0062] Performance test

[0063] The test panel was made, maintained and the performance test was carried out according to the method stipulated by each execution standard. In addition, according to the actual use, some performance test indexes were added. The sample panel was made and the curing process was as follows: the solid wood board, the tin plate and the white porcelain tile for external use were selected, one coating was completed, the coating amount was (100.00±10.00) g / m 2 , and the test was carried out after 7 days of placement.

[0064] The main technical index list of the paint is as follows (Tables 2-5):

[0065] Table 2 General performance indexes of Examples 1-4

[0066]

[0067]

[0068] Table 3 Artificial aging performance indexes of Examples 1-4

[0069]

[0070] Note: [1] The quantity grades 0, 1, 2, 3, 4 and 5 respectively represent: none, very little, a small amount, moderate, more, serious or dense; [2] The blister and cracking size grades S0, S1, S2, S3, S4 and S5 respectively represent: invisible under 10 times magnifying lens, visible under 10 times magnifying lens, visible under normal vision, <0.5 mm bubble (normal vision clearly visible), 0.5 mm-5 mm bubble (1 mm wide cracking), >5 mm bubble (more than 1 mm wide cracking); [3] The mold spot size grades S0, S1, S2, S3, S4 and S5 respectively represent: invisible, visible, <1 mm mold spot, <2 mm mold spot, <5 mm mold spot, ≥5 mm mold spot; [4] The spot size grades S0, S1, S2, S3, S4 and S5 respectively represent: invisible, visible, <1 mm spot, <2 mm spot, <5 mm spot, ≥5 mm spot.

[0071] Table 4 General performance indexes of Comparative Examples 1-4

[0072]

[0073]

[0074] Table 5 Conventional performance indicators of Comparative Examples 5-8

[0075]

[0076]

[0077] Table 6 Artificial aging resistance performance indicators of Comparative Examples 1-4

[0078]

[0079] Table 7 Artificial aging resistance performance indicators of Comparative Examples 5-8

[0080]

[0081] Notes: [1] The quantity levels 0, 1, 2, 3, 4, 5 respectively represent: none, very little, small amount, moderate, more, severe or dense; [2] The blistering and cracking size levels S0, S1, S2, S3, S4, S5 respectively represent: invisible under 10 times magnifying lens, visible under 10 times magnifying lens, visible to normal vision, <0.5mm blister (clearly visible to normal vision), 0.5mm-5mm blister (1mm wide cracking), >5mm blister (more than 1mm wide cracking); [3] The mold spot size levels S0, S1, S2, S3, S4, S5 respectively represent: invisible, visible, <1mm mold spot, <2mm mold spot, <5mm mold spot, ≥5mm mold spot; [4] The spot size levels S0, S1, S2, S3, S4, S5 respectively represent: invisible, visible, <1mm spot, <2mm spot, <5mm spot, ≥5mm spot.

[0082] The test results show that:

[0083] Comparison between Example 1 and Comparative Example 1: In Comparative Example 1, the high-flexibility water-based fluorine-containing emulsion is replaced by a common water-based acrylic emulsion. Although the hardness is improved to a certain extent, the wood will produce cracking and other defects due to the lack of high flexibility, which cannot withstand the stress on the surface of the paint film. The performance indicators such as impact resistance and elongation at break decrease. Moreover, due to the lack of C-F bond energy of fluorine resin, the surface energy increases, resulting in poor performance of the entire system such as stain resistance and weak self-cleaning function.

[0084] Example 2 and Comparative Example 2 are compared: in Comparative Example 2, the self-made modified nano cerium oxide-silicon nitride composite slurry is replaced by an aqueous precipitated barium sulfate water slurry. Although there is no change in the hardness of the coating film, the nano cerium oxide-silicon nitride composite does not have the properties of heat insulation, cold resistance, ultraviolet resistance, antibacterial, and chemical resistance, etc. which are not embodied by barium sulfate, resulting in a serious decline in the comprehensive performance index of the coating film and yellowing of the paint film due to damage by ultraviolet light. Moreover, in terms of aging resistance, the lack of protection of the nano cerium oxide-silicon nitride composite to the coating layer results in a significant decline in various indicators after a certain period of time, and the paint film is severely damaged.

[0085] Example 3 and Comparative Example 3 are compared: in Comparative Example 3, the micro-fine silica aerogel powder is replaced by organic bentonite. For silicon nitride and cerium oxide with high specific gravity, the hydrogen bonds formed by some groups on the silica aerogel form a thixotropic structure, and through its colloidal state in the paint, a network structure is formed to achieve the purpose of preventing sedimentation. Or it is adsorbed on the surface of the pigment and filler, acting as a bridge between the pigment and filler to control the flocculation of the pigment and filler and prevent sedimentation. The same amount of organic bentonite only acts by changing the attraction between the sheets and increasing the viscosity of the system. For inorganic non-metallic materials and rare earth oxides, the effect on sedimentation is not as good as that of silica aerogel. In addition, silica aerogel also has the characteristics of low thermal conductivity and hydrophobicity, which can further prevent moisture absorption while blocking infrared rays, and can provide excellent help to the heat resistance and water resistance of the coating film. Organic bentonite does not have these properties, so it will increase the water absorption of the coating film, resulting in a decrease in the water resistance of the coating film.

[0086] Example 4 and Comparative Example 4 are compared: in Comparative Example 4, the anti-scratch additive is replaced by a water-based leveling agent, reducing the auxiliary effect of the nano cerium oxide-silicon nitride composite on the lubrication, scratch resistance, and wear resistance of the coating film, and also reducing the effective help of fluorine-containing resin on stain resistance and self-cleaning effect. Therefore, in various performance indicators, such as wear resistance, stain resistance, and spot resistance, there is a partial decline in performance.

[0087] Example 1 and Comparative Example 5 are compared: in Comparative Example 5, the tannin acid inhibitor is replaced by deionized water. In single-coat coating, due to the lack of tannin acid inhibitor to block tannin acid, some tannin acid, oil, and pigment contained in wood easily penetrate into the coating film through the water phase, causing the coating film to yellow and discolor. Tannin acid is a weak acid, and in the chemical resistance test, tannin acid will react with alkali, causing the paint film to discolor and be damaged. In the artificial aging test, due to the long-term migration of tannin acid in the coating film, the adhesion between the resin and the substrate decreases, resulting in a failure in the later adhesion test.

[0088] Example 2 compared with Comparative Example 6: In Comparative Example 2, the self-made modified nano cerium oxide-silicon nitride composite slurry was replaced by an aqueous ultraviolet light absorber and deionized water. Although the effect of resisting ultraviolet light was not affected, the coating film lost strength in hardness and rigidity, resulting in a large degree of decline in the physical comprehensive performance index of the coating film. Through comparison, the effect of the ultraviolet absorber was slightly inferior to that of the nano cerium oxide-silicon nitride composite in resisting ultraviolet light within the same aging test period.

[0089] Example 3 compared with Comparative Example 7: In Comparative Example 3, the self-made modified nano cerium oxide-silicon nitride composite slurry was replaced by an aqueous dry film mildew inhibitor and deionized water. For the same reason, the invasion of mold and mildew stains was prevented after film formation, but due to the lack of rigid strength of the coating film, some of the hardness indicators were not up to par. Secondly, due to the loss of ultraviolet light resistance function, the yellow color difference value became larger, and some of the aging test indicators deviated due to the exposure of ultraviolet light.

[0090] Example 4 compared with Comparative Example 8: In Comparative Example 4, the self-made modified nano cerium oxide-silicon nitride composite slurry was completely replaced by nano cerium oxide slurry that was not modified by silicon nitride. Due to the coating effect of the modified nano cerium oxide-silicon nitride composite, it has stronger support and rigidity than the unmodified nano cerium oxide, increases the contact area and stability of the powder and liquid phase, and has a coupling effect with molecules. Not only is the anti-settling effect better, but also the performance in all aspects, including stain resistance and elongation at break, is more excellent.

Claims

1. A high protection waterborne one-coat exterior wood stain, characterized in that Consists of the following composition and weight parts: ； The modified nano cerium oxide-silicon nitride composite slurry is prepared by the following steps: S1: In a nitrogen purging reactor, 100 parts by mass of nano cerium oxide powder is added, 20-30 parts by mass of silicon tetrachloride gas is introduced, then ammonia gas is introduced and reacted at 1000-1500°C for 3-5h; after the reaction is completed, the temperature is lowered to 100-200°C, and the reaction is continued for 1-2h; wherein the molar ratio of ammonia gas to SiCl4 is 1.5-2:1; Supplement excess ammonia and remove the generated ammonium chloride; continue to heat to 600-800°C for 4-6h to make the generated amorphous silicon nitride coated on the surface of nano cerium oxide; finally, after centrifugation, washing, vacuum drying, nano cerium oxide-silicon nitride composite is obtained; S2: Take the nano cerium oxide-silicon nitride composite powder and place it in the KH-560 silane coupling agent solution and make it fully infiltrated, then add acetone as a catalyst, ultrasonic dispersion for 0.5-1h, then stirring dispersion for 6-8h, filter, clean with ethanol, and dry to obtain modified nano cerium oxide-silicon nitride composite powder; S3: 40-60 parts by mass of the nano cerium oxide-silicon nitride composite powder treated with the coupling agent is placed in a paint preparation kettle, 45-55 parts by mass of deionized water, 0.5-3 parts by mass of BYK-190 water-based wetting dispersant, 0.1-1 parts by mass of TEGO ® Airex 904W defoamer and 0.5 parts by mass of KATHON ® After the LXE bactericide is stirred uniformly, it is transferred into a sand mill to grind to a fineness of ≤20 μm, to obtain a modified nano cerium oxide-silicon nitride composite slurry.

2. The high protection waterborne one-coat exterior wood stain according to claim 1, characterized in that The water-based acrylic emulsion is one or more of Wanhua Lacper 4570 water-based acrylic emulsion, Jiafeng Chemical JF1015 water-based core-shell structure acrylic emulsion, Lanke Road L-9130W water-based acrylic resin, and Ruyi Chemical RC-7209 water-based self-crosslinking pure acrylic emulsion.

3. The high-protection water-based outdoor wood bottom and surface one-coat paint according to claim 1, wherein the high-flexibility fluorine-containing acrylic emulsion is one or more of Donglu DF-02 core-shell structure fluorine-containing acrylic fluorine emulsion, Zhonglian Fuman FEM-101 self-crosslinking fluorocarbon emulsion, and Xunda HD-830 self-crosslinking fluorosilicon propylene emulsion.

4. The high protection waterborne one-coat exterior wood stain according to claim 1, characterized in that The substrate wetting agent is at least one of Dow Corning TEGO ® Twin- 4100, TEGO WET KL 245, BYK-346; the defoaming agent is TEGO ® Airex 904W, TEGO ® FOAMEX 810, TEGO ® Airex 902W; the associative polyurethane thickener is Wanhua Vesmody U605, Rheox RHEOLATE 299, Germany Ming Ling TAFIGEL ® PUR40, Puresyn Coadd TM U601.

5. The high protection waterborne all-in-one wood floor coating according to claim 1, characterized in that The tannic acid inhibitor is HALOX L-44 from the United States; the isothiazolinone bactericide is KATHON from Dow Chemical. ® LXE.

6. The high protection waterborne all-in-one wood floor coating according to claim 1, characterized in that the anti-scratch aid is one or more of TEGO ® Glide 482, DOWSIL™ 211S Additive, Michelman ME 95535.S.

7. A method of preparing a high protection waterborne all-in-one wood exterior coating according to claim 1, characterized in that The steps of the method are as follows: In the paint mixing kettle, add water-based acrylic emulsion and high-flexibility fluorine-containing acrylic emulsion and stir uniformly; then add dipropylene glycol methyl ether, dipropylene glycol butyl ether, substrate wetting agent, defoaming agent, anti-scratch aid, and water into the batching kettle and pre-disperse at 800-1000r / min for 0.5-1h to obtain a dispersed mixture; mix the dispersed mixture with modified nano cerium oxide-silicon nitride composite slurry and water-based titanium white paste again, add silica aerogel powder after mixing, continue to disperse at 1000-1500r / min for 0.5-1h, add isothiazolinone bactericide and tannin inhibitor after fine dispersion, mix again, filter after adjusting the system viscosity by adding associated polyurethane thickener, and the high-protection water-based outdoor wood bottom and surface one-coat paint is obtained.

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