Waterproof and stain-resistant additive for water-based wood paint and preparation method thereof

Abstract

The present application relates to the technical fields of silicone functional emulsion preparation, in particular to a high solid content alkoxyl-containing silicone emulsion and a preparation method thereof, which is applied to water-based wood paint and plays a role of water resistance and stain resistance, and is composed of the following raw materials: 50-60 parts of silicone oligomer, 2-5 parts of surfactant, 3-6 parts of cosolvent, 0.1-0.5 parts of pH regulator and 40-50 parts of solvent; the silicone oligomer is a small molecule resin obtained by partial hydrolysis and condensation of alkyl trimethoxysilane. The emulsion prepared by the method has a theoretical solid content of at least 55%, a viscosity of 40-60 mPa·s / 25 DEG C, good and stable waterproof effect, and can be placed for more than one year at room temperature; the emulsion can be cured at medium and high temperatures and can be self-cured at room temperature, and the cured paint film has high hardness, good toughness and high bonding reliability.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of silicone functional emulsion preparation, in particular to a high solid content alkoxyl-containing silicone emulsion and a preparation method thereof, which is applied to water-based wood paint and plays a role of water resistance and stain resistance. BACKGROUND

[0002] Various coating enterprises continuously introduce "oil to water" countermeasures to expand the application field of water-based paint. Water-based wood paint, as a coating variety for indoor furniture and decoration, contributes to reducing the concentration of indoor organic pollutants. Compared with oil-based paint, it is less harmful to the human body, safe and environmentally friendly, and has been pursued and warmly welcomed by market consumers since its launch. At present, water-based wood paint is difficult to completely replace oil-based paint because of its short board in terms of fullness, film hardness, water resistance, stain resistance, etc.

[0003] The resin of water-based wood paint mainly includes water-based alkyd, acrylic emulsion, water-based polyurethane dispersion and water-based acrylic polyurethane dispersion. Water-based paint is usually divided into three types: water-soluble paint, water-thinnable paint and water-dispersible paint (emulsion paint). The high molecular resin of the first two types of paint itself has strong polarity and can be water-soluble or water-dispersible. The emulsion type paint is O / W emulsion, the resin itself is oily, and the emulsifier forms a dynamically stable emulsion or microemulsion. The emulsifier does not volatilize during the curing process of the paint film. Therefore, the water-based resin itself or the emulsifier remains after the construction of the water-based paint, resulting in a considerable hydrophilicity of the paint film, thereby causing a decrease in water resistance and easy contamination. More seriously, it can also cause mold and rot of wood when used in a humid environment.

[0004] It has obvious value to study water-resistant and stain-resistant water-based paint additives to broaden the application environment of water-based paint and improve the performance of the paint film. The relatively mature methods include wax emulsion and silicone rubber emulsion. Both of these two methods add low surface energy emulsion additives to water-based paint. When the water volatilizes and dries, the surface activity of wax and silicone rubber is the driving force for the migration of chain segments to the interface. Migration to the liquid-solid interface helps to improve the wettability of the substrate. It will also migrate to the gas-liquid interface, thereby forming a wax or silicone layer on the surface of the coating. Due to the low interaction between the molecules of wax and silicone, the coating has wear resistance, lubricity, water resistance and stain resistance.

[0005] However, both of the above two types of additives are physically mixed, and the corresponding effects are achieved by phase separation and migration during the film formation process. There is no chemical reaction between the molecules of wax and silicone rubber and the high molecular resin. This is not conducive to improving the hardness of the paint film, and the durability of water resistance and stain resistance is also insufficient.

[0006] A kind of wood efficient permeation type organic silicon waterproof agent invented by Chinese invention patent (publication number CN 105293992B) has good waterproof effect, and has the characteristics of non-toxic, non-pollution and non-corrosion, but is not water-based, which brings inconvenience in transportation. A kind of reinforced waterproof and mildewproof organic silicon waterproof agent invented by Chinese invention patent (publication number CN 103820995B) uses octyl triethoxysilane monomer and silane quaternary ammonium salt as main components, mainly plays a role in antibacterial and mildewproof, and octyl triethoxysilane monomer containing alkoxy silane monomer is directly emulsified, due to the hydrolysis problem of ethoxyl group, viscosity may rise or even gel during storage. There are few reports on water-based wood paint water-resistant and stain-resistant organic silicon waterproof agent in foreign patents such as Europe and the United States. SUMMARY

[0007] The present application provides a small molecule silicon resin emulsion that can be cured at room temperature and medium-high temperature of 50-100 DEG C and has cross-linking activity, and can be miscible with water-based resin at any ratio. In the process of drying and film forming of water-based paint, the silicon resin will be further hydrolyzed and condensed to cure, thereby improving the water resistance and stain resistance of the paint film and also improving the surface hardness of the paint film.

[0008] The technical solution to solve the above technical problems is as follows:

[0009] A water-based wood paint water-resistant and stain-resistant additive is composed of the following raw materials by weight parts:

[0010] Organic silicon oligomer 50-60 parts,

[0011] Surfactant 2-5 parts,

[0012] Cosolvent 3-6 parts,

[0013] pH regulator 0.1-0.5 parts,

[0014] Solvent 40-50 parts.

[0015] The organic silicon oligomer is a small molecule resin obtained by partial hydrolysis and condensation of alkyl trimethoxysilane. Part of the methoxy groups on the oligomer molecular network are reserved to improve the curing reaction activity.

[0016] Further, the alkyl trimethoxysilane is any one or a mixture of multiple of methyl trimethoxysilane, ethyl trimethoxysilane, propyl trimethoxysilane, isobutyl trimethoxysilane, n-hexyl trimethoxysilane and octyl trimethoxysilane. Preferably, propyl trimethoxysilane.

[0017] Preferably, the formula is composed of the following raw materials by weight parts:

[0018] Organic silicon oligomer 57 parts,

[0019] surfactant 2.7 parts,

[0020] co-solvent 5.5 parts,

[0021] pH regulator 0.3 parts,

[0022] solvent 43 parts.

[0023] Further, the surfactant is a mixture of one or more of fatty alcohol polyoxyethylene ether, isomeric tridecanol ethoxylate, and linear secondary alcohol polyoxyethylene ether.

[0024] Further, the co-solvent is methanol or ethanol, preferably methanol.

[0025] Further, the pH regulator is a 1% by mass aqueous potassium hydroxide solution.

[0026] Still further, the solvent is deionized water.

[0027] Another object of the present application is to provide a preparation method of the water-resistant and stain-resistant additive for water-based wood paint described above, comprising the following steps:

[0028] S1: According to the formula, the silicone oligomer is put into a stirrer, heated to 35-40℃, and then the surfactant and co-solvent are added, stirred at 30-40℃ for 10 min, to obtain intermediate product A;

[0029] S2: The solvent is added to the intermediate product A in multiple batches, stirred at 30-40℃ for 30 min, emulsified, and the phase inversion from water-in-oil to oil-in-water is completed, to obtain a stable emulsion, which is intermediate product B;

[0030] S3: The pH regulator is added to the intermediate product B, stirred at 30-40℃ for 10 min, and the pH value of the system is controlled to be 7.0-8.0, to obtain emulsion pre-product C;

[0031] S4: The emulsion pre-product C is put into a high-pressure homogenization emulsifier for homogenization and emulsification, and the pressure of the high-pressure homogenization emulsifier is set to 50 MPa, to obtain the final product D.

[0032] The beneficial effects of the present application are:

[0033] The water-resistant and stain-resistant additive for water-based wood paint prepared by the present application is an alkoxy silicone resin emulsion, with a solid content of 55%, a viscosity of 40-60 mPa.s, and the resin can participate in the film-forming crosslinking of the paint film.

[0034] The use of the co-solvent not only improves the stability of the emulsion, but more importantly, since the silicone oligomer contains methoxy and hydroxy groups, the co-solvent can inhibit the hydrolysis of the methoxy group, thereby improving the storage stability of the emulsion.

[0035] When the surfactant is added to two immiscible liquids, it forms a molecular layer on the surface of the liquid, which can reduce the surface tension of the liquid to a low enough level to allow the two liquids to mix together, thus forming a stable O / W emulsion. Therefore, in the present application, the surfactant acts as an emulsifier.

[0036] The organic silicon oligomer contains a trace amount of acid, and the emulsion formed by the organic silicon oligomer under acidic conditions is not stable. Adjusting the pH of the emulsion to weak alkaline with a pH regulator can achieve long-term stability.

[0037] The presence of methoxy groups in the oligomer enables the emulsion to solidify and crosslink into a film at low temperature. With the continuous volatilization of the cosolvent and water, the methoxy groups and the hydroxyl groups condense and crosslink into a dense film, thereby achieving a waterproof effect, with a water contact angle of up to 125°.

[0038] The water-based wood paint water-resistant and stain-resistant organic silicon emulsion prepared by the present application has the characteristics of high solid content and low viscosity, and can be cured at room temperature and medium-high temperature of 50-100℃, with high film hardness, good weather resistance and color retention, and wide application range.

[0039] The present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 The process flow chart for preparing the water-based wood paint water-resistant and stain-resistant additive of the present application. DETAILED DESCRIPTION

[0041] In order to make the technical means, creative features, purposes and effects achieved by the present application easy to understand, the present application will be further described below in conjunction with specific embodiments, but the following embodiments are only preferred embodiments of the present application, not all. Based on the embodiments in the embodiments, other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0042] In Examples 1-3, a small molecule resin obtained by partial hydrolysis and condensation of propyltrimethoxysilane is selected as the organic silicon oligomer.

[0043] Example 1:

[0044] S1: Put 57 parts of the organic silicon oligomer into a blender, heat to 40℃, then add 2.7 parts of fatty alcohol polyoxyethylene ether and 5.5 parts of methanol, stir at 35℃ for 10 min to obtain intermediate product A;

[0045] S2: Gradually add 43 parts of deionized water to the intermediate product A, stir at 35℃ for 30 min to obtain intermediate product B;

[0046] S3: 0.3 parts of 1% potassium hydroxide aqueous solution by mass fraction was added to the intermediate product B, stirred at 35°C for 10 min, and the pH value of the system was controlled at 7.0-8.0 to obtain emulsion preform C;

[0047] S4: The emulsion preform C was put into a high-pressure homogenization emulsifier, and the pressure of the high-pressure homogenization emulsifier was set to 50 MPa to obtain the final product D.

[0048] Example 2:

[0049] S1: 57 parts of silicone oligomer was put into a stirrer, heated to 40°C, then 2.7 parts of straight-chain secondary alcohol polyoxyethylene ether and 5.5 parts of methanol were added, stirred at 350°C for 10 min to obtain intermediate product A;

[0050] S2: 43 parts of deionized water was gradually added to the intermediate product A, stirred at 35°C for 30 min to obtain intermediate product B;

[0051] S3: 0.3 parts of 1% potassium hydroxide aqueous solution by mass fraction was added to the intermediate product B, stirred at 35°C for 10 min, and the pH value of the system was controlled at 7.0-8.0 to obtain emulsion preform C;

[0052] S4: The emulsion preform C was put into a high-pressure homogenization emulsifier, and the pressure of the high-pressure homogenization emulsifier was set to 50 MPa to obtain the final product D.

[0053] Example 3:

[0054] S1: 57 parts of silicone oligomer was put into a stirrer, heated to 40°C, then 2.7 parts of straight-chain secondary alcohol polyoxyethylene ether and 5.5 parts of methanol were added, stirred at 350°C for 10 min to obtain intermediate product A;

[0055] S2: 43 parts of deionized water was gradually added to the intermediate product A, stirred at 35°C for 30 min to obtain intermediate product B;

[0056] S3: 0.3 parts of 1% potassium hydroxide aqueous solution by mass fraction was added to the intermediate product B, stirred at 35°C for 10 min, and the pH value of the system was controlled at 7.0-8.0 to obtain emulsion preform C;

[0057] S4: The emulsion preform C was put into a high-pressure homogenization emulsifier, and the pressure of the high-pressure homogenization emulsifier was set to 50 MPa to obtain the final product D.

[0058] Example 4:

[0059] Methyl trimethoxysilane partially hydrolyzed-condensed small molecule resin was selected as the silicone oligomer.

[0060] S1: Add 50 parts of organosilicon oligomer to a mixer, heat to 35°C, then add 2.7 parts of linear secondary alcohol polyoxyethylene ether and 3 parts of methanol, stir at 40°C for 10 min to obtain intermediate product A;

[0061] S2: Gradually add 40 parts of deionized water to intermediate product A and stir at 30°C for 30 min to obtain intermediate product B;

[0062] S3: Add 0.1 part of 1% potassium hydroxide aqueous solution to intermediate product B, stir at 40℃ for 10 min, and control the pH of the system to 7.0-8.0 to obtain emulsion preform C;

[0063] S4: The emulsion preform C is fed into a high-pressure homogenizer for homogenization and emulsification. The pressure of the high-pressure homogenizer is set to 50 MPa to obtain the final product D.

[0064] Example 5:

[0065] Small molecule resins formed by the partial hydrolysis-condensation of a mixture of ethyltrimethoxysilane and octyltrimethoxysilane in equal mass ratio were selected as organosilicon oligomers.

[0066] S1: Add 55 parts of organosilicon oligomer to a mixer, heat to 38°C, then add 5 parts of fatty alcohol polyoxyethylene ether and 4 parts of methanol, stir at 30°C for 10 min to obtain intermediate product A.

[0067] S2: Gradually add 50 parts of deionized water to intermediate product A and stir at 40°C for 30 min to obtain intermediate product B;

[0068] S3: Add 0.2 parts of 1% potassium hydroxide aqueous solution to intermediate product B, stir at 30℃ for 10 min, and control the pH of the system to 7.0-8.0 to obtain emulsion preform C;

[0069] S4: The emulsion preform C is fed into a high-pressure homogenizer for homogenization and emulsification. The pressure of the high-pressure homogenizer is set to 50 MPa to obtain the final product D.

[0070] Example 6:

[0071] Small molecule resins formed by the partial hydrolysis-condensation of a mixture of ethyltrimethoxysilane, propyltrimethoxysilane and octyltrimethoxysilane in equal mass ratio were selected as organosilicon oligomers.

[0072] S1: Add 60 parts of organosilicon oligomer to a mixer, heat to 36°C, then add 2 parts of isomeric tridecyl alcohol ethoxylate, 2 parts of linear secondary alcohol polyoxyethylene ether and 6 parts of ethanol, stir at 33°C for 10 min to obtain intermediate product A.

[0073] S2: 46 parts of deionized water was gradually added to the intermediate product A, stirred at 38℃ for 30min, to obtain the intermediate product B;

[0074] S3: 0.5 parts of 1% potassium hydroxide aqueous solution was added to the intermediate product B, stirred at 37℃ for 10min, the pH value of the system was controlled at 7.0-8.0, to obtain the emulsion preform C;

[0075] S4: The emulsion preform C was put into the high-pressure homogenization emulsifier, and the pressure of the high-pressure homogenization emulsifier was set to 50MPa, to obtain the final product D.

[0076] Example 7:

[0077] The partially hydrolyzed-condensed small molecule resin of isobutyl trimethoxysilane was selected as the silicone oligomer.

[0078] S1: 60 parts of the silicone oligomer was put into the stirrer, heated to 36℃, then 2 parts of isomeric tridecanol ethoxylate and 6 parts of ethanol were added, stirred at 33℃ for 10min, to obtain the intermediate product A;

[0079] S2: 46 parts of deionized water was gradually added to the intermediate product A, stirred at 38℃ for 30min, to obtain the intermediate product B;

[0080] S3: 0.5 parts of 1% potassium hydroxide aqueous solution was added to the intermediate product B, stirred at 37℃ for 10min, the pH value of the system was controlled at 7.0-8.0, to obtain the emulsion preform C;

[0081] S4: The emulsion preform C was put into the high-pressure homogenization emulsifier, and the pressure of the high-pressure homogenization emulsifier was set to 50MPa, to obtain the final product D.

[0082] Example 8:

[0083] The partially hydrolyzed-condensed small molecule resin of isobutyl trimethoxysilane and n-hexyl trimethoxysilane was selected as the silicone oligomer.

[0084] S1: 60 parts of the silicone oligomer was put into the stirrer, heated to 36℃, then 2.5 parts of isomeric tridecanol ethoxylate, 2 parts of linear secondary alcohol polyoxyethylene ether and 6 parts of ethanol were added, stirred at 33℃ for 10min, to obtain the intermediate product A;

[0085] S2: 46 parts of deionized water was gradually added to the intermediate product A, stirred at 38℃ for 30min, to obtain the intermediate product B;

[0086] S3: 0.5 parts of 1% mass fraction potassium hydroxide aqueous solution was added to the intermediate product B, and stirred at 37 DEG C for 10 min, the pH value of the system was controlled to be 7.0-8.0, to obtain emulsion preform C;

[0087] S4: the emulsion preform C was put into a high-pressure homogenization emulsifier, and the pressure of the high-pressure homogenization emulsifier was set to 50 MPa, to obtain the final product D.

[0088] Table 1 is the formula table of examples 1-8, because examples 1-8 contain methoxy, so the loss on drying method test cannot be carried out, the theoretical solid content is at least 55%, and the viscosity is 40-60 mPa·s / 25 DEG C.

[0089] Table 1 formula table of examples 1-8

[0090] Example 1 2 3 4 5 6 7 8 Silicone oligomer 57 57 57 50 55 60 60 60 Fatty alcohol polyoxyethylene ether 2.7 5 Straight-chain secondary alcohol polyoxyethylene ether 2.7 2.7 2 2 Isomeric tridecanol ethoxylate 2.7 2 2 2.5 Methanol 5.5 5.5 5.5 3 4 Ethanol 6 6 6 1% wt KOH aqueous solution 0.3 0.3 0.3 0.1 0.2 0.5 0.5 0.5 Deionized water 43 43 43 40 50 46 46 46 Room temperature stabilization time (days) 14 ＞365 35 28 56 198 ＞365 ＞365 Viscosity (mPa.s / 25°C) 56 50 54 58 52 58 58 60

[0091] When applied, the final product D, i.e. the water-resistant and stain-resistant additive prepared by the application, is added to the common acrylic emulsion type wood paint to be miscible.

[0092] The detection method of the application is as follows:

[0093] 5 parts of different silicon emulsion additives prepared in examples 1-8 were respectively added to 95 parts of Dow Chemical ROSHIELD TM 3638A acrylic emulsion wood paint to be miscible, and a blank test control group was set.

[0094] The film parameters are shown in Table 2 as follows:

[0095] Table 2 film parameters

[0096] Item Parameter Acrylic emulsion wood lacquer 95 parts Silicone emulsion 5 parts Substrate Glass plate film Wet film thickness 125 μm Curing conditions 20-25°C, 24 hours

[0097] The water contact angle was detected according to the standard GB / T24368-2009, the adhesion was detected according to the standard GB / T9286-1998, the flexibility was detected according to the standard GB / T1731-2020, the film hardness was tested according to the standard GB / T6739-2006, the alcohol resistance, water resistance and stability were detected according to the standard GB / T23999-2009, and the stain resistance was detected according to the standard GB / T 9780-2013, and the results are shown in Table 3 as follows:

[0098] Table 3 performance test of different silicon resin emulsion additives

[0099]

[0100]

[0101] As shown in Table 3, the water-resistant and stain-resistant additive prepared by the present application is an alkoxyl-containing silicone emulsion with high solid content, low viscosity, good stability, and good water resistance and stain resistance, and the cured film has high hardness and good toughness, and high bonding reliability.

[0102] The oligomer synthesized by using propyltrimethoxysilane in Examples 1-3 is emulsified. The propyl C3H7 has moderate steric hindrance, and the residual methoxy groups on the molecular network are not prone to further hydrolysis and condensation at room temperature, so the emulsion has good stability. After the water is volatilized, the methoxy groups on the oligomer participate in the curing reaction under the action of the catalyst and the crosslinking agent. The silicone emulsion is added to 5% by mass in the acrylic emulsion type wood paint, and is coated on a glass plate to be cured and formed. The propyl C3H7 has better compatibility with the main film-forming resin than the methyl CH3, so that the film has good flexibility and the hardness is increased from H of the blank to 2H. On the basis of the control group, the film has significantly improved hydrophobicity, and the water drop angle is more than 120°. The water resistance, alcohol resistance and stain resistance are all significantly improved.

[0103] The oligomer synthesized by using methyltrimethoxysilane in Example 4 is emulsified. Since the CH3 has small steric hindrance, the residual methoxy groups on the molecular network tend to hydrolyze and condense at room temperature. Although the same surfactant, i.e. emulsifier, as in Example 2 is used, the emulsion has a stable time of only 28 days. The silicone emulsion is added to 5% by mass in the acrylic emulsion type wood paint, and is coated on a glass plate to be cured and formed. The methyl carbon chain is shorter than the propyl, and the hydrophobicity is relatively low, and the film has a water drop angle of less than 120°. The oligomer has poor compatibility with the main film-forming resin, resulting in decreased flexibility and hardness of the film, and the film bending radius is 5 mm. The lack of compatibility is accompanied by a decrease in the water resistance and alcohol resistance of the film compared with Example 2.

[0104] The oligomer synthesized by co-hydrolysis of ethyltrimethoxysilane and octyltrimethoxysilane in Example 5 is then formulated. The ethyl and octyl groups have large differences in steric hindrance, similar to the difference in "reactivity ratio" in free radical polymerization. The ethyl silane will preferentially hydrolyze and condense with the octyl silane, and the outer edge of the molecular network will have more octyl groups. The octyl C8 has a long carbon chain and has good compatibility with the main film-forming resin. However, the reaction has large steric hindrance, and the oligomer itself is not easy to cure or graft to the crosslinking network of the film-forming resin. The silicone emulsion is added to 5% by mass in the acrylic emulsion type wood paint, and is coated on a glass plate to be cured and formed. The obtained film is softer, and the flexibility test shaft rod diameter reaches 2 mm. The long carbon chain is prone to migration and is more hydrophobic, and the film has a higher water drop angle than Example 2. The film has excellent water resistance, alcohol resistance and stain resistance.

[0105] Example 6 uses ethyl trimethoxysilane, propyl trimethoxysilane, octyl trimethoxysilane co-hydrolysis synthesis of oligomers, and then emulsified. The effect is similar to Example 5. Because of the different emulsifier collocation, the room temperature storage stability of the emulsion is longer than Example 5.

[0106] Example 7 and 8, using different emulsifier formulations, the storage stability of the emulsion obtained is different. Among them, when using linear secondary alcohol polyoxyethylene ether emulsification, the emulsifier addition amount is small, and the storage stability is still good, and the product itself can be placed at room temperature for more than one year. Add 5% mass fraction of silicone emulsion to the acrylic emulsion type wood paint, coat on the glass plate and solidify to form. Because the isobutyl and n-hexyl group has a longer molecular chain than the propyl group, it has good hydrophobicity, so it has excellent water and alcohol resistance. At the same time, because the molecular group has large steric hindrance, the paint film flexibility test shaft rod diameter can also reach 2mm.

[0107] Through comprehensive analysis of the above data, Example 2 is the best choice among all the schemes. But it does not mean that other schemes cannot get better results after optimization.

[0108] The above is only the preferred embodiment of the present application, and does not limit the present application in any form. Any simple modification or equivalent change made on the basis of the technical essence of the present application to the above embodiments falls within the scope of protection of the present application.

Claims

1. A method for preparing a water-resistant and stain-resistant additive for water-based wood coatings, characterized in that, The water-based wood coating water-resistant and stain-resistant additive is composed of the following raw materials in parts by weight: 50-60 parts of organosilicon oligomer 2-5 parts of surfactant 3-6 parts of cosolvent pH adjuster 0.1-0.5 parts, Solvent 40-50 parts; The organosilicon oligomer is a small molecule resin formed by partial hydrolysis-condensation of propyltrimethoxysilane; some methoxy groups are retained on the molecular network of the organosilicon oligomer to improve the curing reaction activity; The surfactant is one or more of fatty alcohol polyoxyethylene ether, isotridecyl alcohol ethoxylate, and linear secondary alcohol polyoxyethylene ether; The co-solvent is methanol or ethanol; The solvent is deionized water; Includes the following steps: S1: According to the formula, put the organosilicon oligomer into a mixer, heat it to 35-40°C, then add the surfactant and cosolvent, stir at 30-40°C for 10 minutes to obtain intermediate product A; S2: Add solvent to intermediate product A in multiple batches, stir at 30-40℃ for 30 min to complete emulsification, and obtain intermediate product B; S3: Add a pH adjuster to intermediate product B, stir at 30-40℃ for 10 min, and control the pH of the system to 7.0-8.0 to obtain emulsion preform C; S4: The emulsion preform C is fed into a high-pressure homogenizer for homogenization and emulsification. The pressure of the high-pressure homogenizer is set to 50 MPa to obtain the final product D.

2. The preparation method according to claim 1, characterized in that, The water-based wood coating water-resistant and stain-resistant additive is composed of the following raw materials in parts by weight: 57 parts of organosilicon oligomers 2.7 parts of surfactant 5.5 parts of co-solvent pH adjuster 0.3 parts, 43 parts solvent.

3. The preparation method according to claim 1, characterized in that, The co-solvent is methanol.

4. The preparation method according to claim 1 or 2, characterized in that, The pH adjuster is a 1% (w / w) aqueous solution of potassium hydroxide.

Images