Water-based high-content organic silicon modified acrylate dispersion and application thereof in stain-resistant coating

Abstract

The invention discloses a water-based high-content organic silicon modified acrylate dispersion and application thereof in a stain-resistant coating, and belongs to the field of high polymer material synthesis and coatings. According to the invention, the organosilicon prepolymer is introduced, the organosilicon prepolymer is placed in the mixed monomer, and the organosilicon prepolymer is successfully introduced into the organosilicon acrylate dispersion by utilizing the dispersion emulsification process, so that the silicon content of the antifouling paint is effectively improved, and more organosilicon with low surface energy is spontaneously enriched to the surface in the film forming process; and the antifouling coating can have excellent stain resistance. Molecular-scale mixing of the prepared organic silicon prepolymer and organic silicon acrylate resin is realized in the emulsification process, and the organic silicon prepolymer reacts in the drying process, so that the scrubbing resistance of the stain-resistant coating is enhanced.

Description

Technical Field

[0001] The invention relates to a water-based high-content organosilicon-modified acrylate dispersion and application thereof in a stain-resistant coating, belonging to the field of polymer material synthesis and coatings. Background Art

[0002] Acrylate-based waterborne coatings are widely used in the field of waterborne coatings due to their excellent film-forming properties, mechanical strength and weather resistance, and are commonly seen in the surface treatment of textiles, fibers and artificial leather. However, the hydrophilic groups contained in polyacrylate molecules, such as hydroxyl and carboxyl groups, result in low water resistance and anti-fouling properties of the coatings. This shortcoming limits its further application in waterborne functional coating materials.

[0003] Silicone, due to its low surface tension and excellent hydrophobic and oleophobic properties of the siloxane main chain, significantly enhances anti-fouling performance. Compounding silicone with water-based acrylic resin can effectively improve the water resistance and anti-fouling properties of the coating. At present, silicone-modified acrylate dispersions are generally prepared by solution polymerization. Usually, the silicone content in the silicone-modified resin synthesized by solution polymerization is 1-20wt%, which is low, and the anti-fouling property of the prepared coating needs to be further improved.

[0004] For example, CN 116554751 A is prepared by mixing a homemade high-content silicone-modified acrylate resin, a pure acrylate resin and a curing agent, and then composite emulsifying them during the preparation of an aqueous dispersion, so that the final prepared coating has excellent stain resistance; however, the coating preparation procedure is complicated, the solvent resistance is poor, and the stain resistance needs to be further improved.

[0005] Regarding silicone-modified acrylates, current research focuses on the effects of resin composition, silicone type, molecular weight and content on coating performance, but there is less in-depth research on the synthesis of high silicone content resins. The surface of high-content silicone acrylate coatings is enriched with more low-surface energy silicone, providing the coating with excellent hydrophobicity and good stain resistance. Summary of the invention

[0006] [Technical issues]

[0007] In the organosilicon modified resin synthesized by solution polymerization, the organosilicon content is 1-20wt%, which is relatively low. ;

[0008] There is little research on the synthesis of high silicone content resins and the application of silicone prepolymers in the field of water-based coatings.

[0009] [Technical solution]

[0010] In order to solve the above problems, the present invention introduces an organosilicon prepolymer, places the organosilicon prepolymer in a mixed monomer, and utilizes the dispersion emulsification process to successfully introduce the organosilicon prepolymer into the organosilicon acrylate dispersion, thereby effectively increasing the silicon content of the antifouling coating. During the film-forming process, more low-surface-energy organosilicon spontaneously accumulates on the surface, which enables the antifouling coating to have excellent anti-fouling properties.

[0011] The first object of the present invention is to provide a method for preparing a water-based high-content silicone-modified acrylate resin, comprising the following steps:

[0012] (1) mixing an organosilicon acrylate monomer, a hydroxyl-containing acrylate monomer, a carboxyl acrylate monomer, and other acrylate monomers, adding a chain transfer agent, and then adding an organosilicon prepolymer and mixing them uniformly to obtain a mixed monomer;

[0013] (2) mixing the initiator and the mixed solvent uniformly to obtain an initiator solution;

[0014] (3) Firstly, a solvent is added to the reaction container for reflux, and then an initiator solution and a mixed monomer solution are added dropwise to carry out polymerization. After the polymerization is completed, a water-based high-content silicone-modified acrylate resin is obtained.

[0015] In one embodiment of the present invention, the silicone acrylate monomer is one or both of methacrylate-terminated polydimethylsiloxane (PDMS-MA) and acrylate-terminated polydimethylsiloxane having a functionality of 1 and a molecular weight of 1000-8000.

[0016] In one embodiment of the present invention, the hydroxyl-containing acrylic ester monomer is one or more of hydroxyethyl acrylate (2-HEA), hydroxyethyl methacrylate (HEMA), and hydroxypropyl acrylate (HPA).

[0017] In one embodiment of the present invention, the carboxyl acrylate monomer is one or both of acrylic acid (AA) and methacrylic acid (MAA).

[0018] In one embodiment of the present invention, the other acrylic ester monomers are one or more of methyl methacrylate (MMA), methyl acrylate (MA), ethyl acrylate (EA), butyl methacrylate (BMA), butyl acrylate (BA), isooctyl methacrylate (EHMA), and isooctyl acrylate (2-EHA).

[0019] In one embodiment of the present invention, the chain transfer agent is one or more of dodecyl mercaptan, mercaptoethanol, thioglycolic acid, and isooctyl 3-mercaptopropionate.

[0020] In one embodiment of the present invention, the organosilicon prepolymer (PDMS) is one or more of Dow Corning Sylgard-184, Dow Corning MDX4-4210, and Kraft K-5318W.

[0021] In one embodiment of the present invention, the initiator is one or more of azobisisoheptanonitrile, azobisisobutylamidine hydrochloride, azobisisobutylimidazoline hydrochloride, azobisisobutylimidazoline, azobiscyanovaleric acid, and dibenzoyl peroxide.

[0022] In one embodiment of the present invention, the mixed solvent is two or more of acetone, butanone, dimethyl carbonate, propylene glycol methyl ether acetate, tetrahydrofuran, toluene, and butyl acetate, and is further preferably a mixed solvent of acetone and tetrahydrofuran, and the mass ratio of acetone to tetrahydrofuran is 3:2.

[0023] In one embodiment of the present invention, the solvent is one or more of acetone, butanone, tetrahydrofuran, propylene glycol monomethyl ether, and propylene glycol methyl ether acetate.

[0024] In one embodiment of the present invention, the mass ratio of silicone acrylate monomer, hydroxyl acrylate monomer, carboxyl acrylate monomer, other acrylate monomers, chain transfer agent and silicone prepolymer is 40-70:2-5:3-10:10-40:1-5:5-15; more preferably 50:5:6:39:1:10.

[0025] In one embodiment of the present invention, the mass ratio of silicone monomer, hydroxyl acrylate monomer, carboxyl acrylate monomer, other acrylate monomer, chain transfer agent, silicone prepolymer, initiator, mixed solvent and solvent is 40-70:2-5:3-10:10-40:1-5:5-15:1-4:40-50:5-10; more preferably 50:5:6:39:1:10:1:50:10.

[0026] In one embodiment of the present invention, the initiator and the mixed solvent are mixed by ultrasonic mixing.

[0027] In one embodiment of the present invention, the parameters of the solvent reflux are set as follows: heating in an oil bath to condense and reflux the solvent for 15 minutes and passing N2 to exhaust the air in the device.

[0028] In one embodiment of the present invention, the dripping speed of the initiator solution and the mixed monomer solution is 0.1-0.5 g / min.

[0029] In one embodiment of the present invention, the polymerization is carried out at 75-80° C., the dropping time is controlled at 3-5 hours, and the temperature is kept at 6-8 hours.

[0030] In one embodiment of the present invention, the solid content of the water-based high-content silicone-modified acrylate resin is 20-60wt%; wherein, solid content (%) = (W 干重 -W 湿重 ) / W 干重 ×100%.

[0031] The second object of the present invention is the water-based high-content silicone-modified acrylate resin prepared by the method of the present invention.

[0032] The third object of the present invention is to provide a method for preparing an aqueous high-content silicone-modified acrylate dispersion, comprising the following steps:

[0033] A neutralizing agent is added to a water-based high-content silicone-modified acrylate resin, and the mixture is stirred to fully neutralize the resin into a salt to obtain a neutralized resin;

[0034] Water is added dropwise to the neutralized resin for high-speed shear emulsification. After the addition is complete, the mixture is stirred at a low speed for defoaming. The mixed solvent in the resin is removed by rotary evaporation to obtain a water-based high-content silicone-modified acrylate dispersion.

[0035] In one embodiment of the present invention, the neutralizing agent is one or more of triethylamine, triethanolamine and aminoacetic acid.

[0036] In one embodiment of the present invention, the molar ratio of the amine group in the neutralizer to the carboxyl group in the water-based high-content silicone-modified acrylate resin is 1:1.

[0037] In one embodiment of the present invention, the conditions for neutralization to form salt are reaction at 20-30° C. for 0.5-1.5 h.

[0038] In one embodiment of the present invention, the mass ratio of the neutralizing resin to water is 50-150:500, more preferably 100:500.

[0039] In one embodiment of the present invention, the water is added at a rate of 15-25 g / min, preferably 20 g / min, and high-speed stirring is required during the addition, with a stirring speed of 500-1500 rpm, preferably 1000 rpm.

[0040] In one embodiment of the present invention, the high-speed shear emulsification is high-speed shearing at 500-1500 rpm for 20-40 min, and more preferably high-speed shearing at 1000 rpm for 30 min.

[0041] In one embodiment of the present invention, the low-speed stirring defoaming is 50-150 rpm stirring defoaming for 1-2 hours; more preferably, it is 100 rpm stirring defoaming for 1.5 hours.

[0042] In one embodiment of the present invention, the rotary evaporation is carried out under reduced pressure at 55-65°C, more preferably under reduced pressure at 60°C.

[0043] In one embodiment of the present invention, the solid content of the aqueous high-content silicone-modified acrylate dispersion is 20-30 wt %; solid content (%) = (W 干重 -W 湿重 ) / W 干重 ×100%.

[0044] The fourth object of the present invention is an aqueous high-content silicone-modified acrylate dispersion prepared by the method of the present invention.

[0045] The fifth object of the present invention is to provide a water-based anti-fouling coating, the components of which include a water-based high-content silicone-modified acrylate dispersion, a crosslinking agent, a curing agent, a cosolvent, a defoamer, a wetting agent, and a thickener;

[0046] Among them, the mass ratio of aqueous high-content silicone-modified acrylate dispersion, crosslinking agent, curing agent, cosolvent, defoaming agent, wetting agent and thickener is 70-90: 0.3-0.6: 4-7: 15-25: 0.6-0.8: 1-2: 0.05-0.15; more preferably 80: 0.4: 5: 20: 0.72: 1.5: 0.1.

[0047] In one embodiment of the present invention, the cross-linking agent is one or both of aziridines and carbodiimides.

[0048] In one embodiment of the present invention, the curing agent is a water-based isocyanate curing agent, specifically one or more of Shiquanxing F-70D, Jiubang Chemical JB-696C, Asahi Kasei WS20-70D, and Guanzhi New Materials BL-8127; the amount is determined according to the hydroxyl content in the silicone-modified acrylate dispersion as n(NCO):n(OH)=0.8-1.2:1.

[0049] In one embodiment of the present invention, the co-solvent is one or more of propylene glycol methyl ether acetate, N,N-dimethylformamide, dimethyl sulfoxide, and dimethylacetamide.

[0050] In one embodiment of the present invention, the defoaming agent is one or more of BYK-038, BYK-025, Airex-530, and PB-9299.

[0051] In one embodiment of the present invention, the wetting agent is one or more of Dow CF-10, BYK-103, and X-405.

[0052] In one embodiment of the present invention, the thickener is one or more of BASF SC-96, BYK-7600, and BYK-3300.

[0053] The sixth object of the present invention is a method for preparing a water-based anti-fouling coating, comprising the following steps:

[0054] The aqueous high-content silicone-modified acrylate dispersion, the crosslinking agent, and the curing agent are stirred and mixed evenly, and then a cosolvent, a defoaming agent, a wetting agent, and a thickener are added, and the mixture is continued to be evenly mixed to remove bubbles, so as to obtain a water-based stain-resistant coating.

[0055] In one embodiment of the present invention, the uniform mixing is performed by stirring at room temperature (20-30° C.) for 20-40 minutes.

[0056] The seventh object of the present invention is to provide a water-based anti-fouling coating, which adopts the water-based anti-fouling coating described in the present invention.

[0057] In one embodiment of the present invention, the water-based anti-fouling coating is coated on the surface of the substrate, dried at room temperature (20-30°C) for 1 hour, then dried at 80°C for 20-40 minutes, and then dried at 130-150°C for 20-40 minutes.

[0058] In one embodiment of the present invention, the thickness of the water-based anti-fouling coating is 5-20 μm.

[0059] In one embodiment of the present invention, the substrate of the water-based stain-resistant coating is leather, plastic, rubber, fiber, glass, metal, fabric, wood, etc.

[0060] The eighth objective of the present invention is the application of the water-based high-content silicone-modified acrylate resin, water-based high-content silicone-modified acrylate dispersion, and water-based anti-fouling coating described in the present invention in the field of anti-fouling treatment.

[0061] [Beneficial Effects]

[0062] (1) The present invention optimizes the composition and dosage of functional monomers and mixed solvents to ensure the smooth progress of solution polymerization, and prepares a water-dispersible high-content silicone-modified acrylate resin, which can be used in the subsequent preparation of water-based stain-resistant coatings.

[0063] (2) The present invention introduces organosilicon prepolymer PDMS, places the organosilicon prepolymer PDMS in a mixed monomer, and successfully introduces the organosilicon prepolymer PDMS into the organosilicon acrylate dispersion by utilizing the dispersion emulsification process, thereby effectively increasing the silicon content of the coating. During the film-forming process, more low-surface-energy organosilicon spontaneously accumulates on the surface, enabling the coating to have excellent stain resistance.

[0064] (3) The organic silicon prepolymer prepared by the present invention and the organic silicon acrylate resin are mixed at the molecular scale during the emulsification process, and the organic silicon prepolymer reacts during the drying process, thereby enhancing the scrub resistance of the anti-fouling coating. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 These are the water absorption test results of the coatings formed by WSiPA-10-C, WSiPA-5-C, WSiPA-15-C, and WSiPA-0-C.

[0066] Figure 2 Stress-strain curves of coatings formed by coatings WSiPA-10-C, WSiPA-5-C, WSiPA-15-C, and WSiPA-0-C.

[0067] Figure 3 Static water contact angle bar graphs and digital photos of coatings formed by coatings WSiPA-10-C, WSiPA-5-C, WSiPA-15-C, and WSiPA-0-C.

[0068] Figure 4 These are digital photos of the oil-pen stain resistance of the coatings formed by the coatings WSiPA-10-C, WSiPA-5-C, WSiPA-15-C, and WSiPA-0-C. Figures 1-3 are the results after oil-pen staining, after wiping with a dry paper towel, and after wiping with an alcohol cotton, respectively. DETAILED DESCRIPTION

[0069] The preferred embodiments of the present invention are described below. It should be understood that the embodiments are for better explaining the present invention and are not used to limit the present invention.

[0070] Test method:

[0071] 1. Water absorption:

[0072] The water resistance of the film was determined according to GB 1733-1993.

[0073] The film sample (m0) was immersed in deionized water. After every 24 hours, the sample was taken out, the surface moisture was wiped dry and the sample was weighed (m1).

[0074] Water absorption (W) is calculated using the following formula:

[0075] W (wt%) = (m1-m0) / m0×100%

[0076] 2. Hydrophobic properties:

[0077] An optical contact angle meter was used to test the static water contact angle of the coating. The water drop volume was 3 μL, and the average value was obtained by testing five locations.

[0078] 3. Mechanical properties:

[0079] Desktop tensile testing machine-tensile test:

[0080] The tensile properties of the film were tested using a universal testing machine 5967, Instron, with a tensile rate of 30 mm / min and a dumbbell-shaped sample with a length of 16 mm and a width of 2 mm.

[0081] 4. Anti-fouling performance:

[0082] Use an oil-based marker pen (Delistar 6824) to leave stains on the coating surface. After 1 hour, wipe the stains with a dry paper towel and observe the residual stains on the coating surface.

[0083] Evaluation criteria for stain resistance:

[0084] Excellent - Oily pen stains on the coating surface can be completely wiped clean without leaving any stains;

[0085] Good - After wiping with a paper towel, a small amount of oil pen stains remain on the coating surface (<20% of the area contaminated by the oil pen stains);

[0086] Medium - After wiping with a paper towel, a lot of oily pen stains remain on the coating surface (20-40% of the area contaminated by the oily pen stains). Poor - After wiping with a paper towel, a lot of oily pen stains remain on the coating surface (40-60% of the area contaminated by the oily pen stains);

[0087] 5.Solvent resistance:

[0088] The coating surface was wiped 50 times with a 200 g weight wrapped in non-woven fabric soaked in anhydrous ethanol, acetone and ethyl acetate, and its surface phenomenon was observed.

[0089] Evaluation criteria for solvent resistance:

[0090] Sticky-the coating surface is damaged by the swelling of the solvent, and the surface becomes sticky;

[0091] Slightly sticky - the coating surface is slightly swollen by the solvent, and the surface is slightly sticky;

[0092] Relatively intact - the coating surface is not obviously swollen by the solvent and the surface is relatively intact;

[0093] Intact - The coating shows almost no traces of solvent wiping and has a smooth, intact surface.

[0094] 6. Surface silicon content test:

[0095] The surface silicon content was obtained by XPS testing method.

[0096] The raw materials used in the examples are:

[0097] PDMS: Model: Dow Corning Sylgard 184, purchased from Shanghai Kaiyin Chemical Co., Ltd.;

[0098] PDMS-MA: methacrylate-terminated polydimethylsiloxane with a functionality of 1 and a molecular weight of 1000-8000.

[0099] Aziridine cross-linking agent: model XL-706, purchased from Guangzhou Yangsong Trading Co., Ltd.;

[0100] Water-based isocyanate curing agent: model: Shiquanxing F-70D, purchased from Shanghai Kaiyin Chemical Co., Ltd.;

[0101] Cosolvent: propylene glycol monomethyl ether, purchased from Shanghai Hushi Technology Co., Ltd.;

[0102] Defoaming agent: Airex-530, purchased from Dalian Liansheng Trading Co., Ltd.;

[0103] Wetting agent: Dow CF-10, purchased from Shanghai Kaiyin Chemical Co., Ltd.;

[0104] Thickener: model BYK-3300, purchased from Dalian Liansheng Trading Co., Ltd.;

[0105] PET film treated with polyurethane primer: purchased from Jiangsu Stdick New Materials Co., Ltd.

[0106] The reactions in the embodiments and comparative examples without specifying the reaction temperature refer to room temperature (20-30° C.), and the % without specifying the meaning refers to mass percentage.

[0107] Example 1

[0108] A method for preparing a water-based high-content silicone-modified acrylate resin comprises the following steps:

[0109] (1) 25 g of methacrylate-terminated modified polydimethylsiloxane (PDMS-MA) (accounting for 50 wt% of the total acrylate monomers), 2.5 g of hydroxyethyl acrylate (2-HEA), 3 g of acrylic acid (AA), 10 g of methyl methacrylate (MMA), 7.5 g of butyl acrylate (BA), and 2 g of isooctyl methacrylate (EHMA) were mixed evenly, 0.5 g of dodecyl mercaptan was added, and then 5 g of organosilicon prepolymer (PDMS) (accounting for 10 wt% of the total acrylate monomers) was added, and the mixture was continued to obtain 55.5 g of a mixed monomer;

[0110] (2) 1 g of initiator azobisisoheptanenitrile and 50 g of a mixed solvent (30 g of acetone and 20 g of tetrahydrofuran) were ultrasonically treated for 5 min to completely dissolve and mix well to obtain 51 g of an initiator solution;

[0111] (3) Add 10 g of solvent (butanone) to the bottom of a four-necked flask, heat in an oil bath at 80°C to condense and reflux the solvent for 15 min while passing nitrogen to exhaust the air in the device;

[0112] The initiator solution and the mixed monomer solution were added to the constant pressure dropping funnel respectively, the polymerization temperature was controlled at 80°C, and the dropping was started at the same time. The dropping speed was 0.2g / min, and the dropping was completed in 5 hours. The temperature was kept for 8 hours to ensure that all monomers participated in the reaction, and a water-based high-content silicone-modified acrylate resin was obtained.

[0113] The water-based high-content silicone-modified acrylate resin has a transparent solution with a blue glow. After complete polymerization, the resin solid content is 43.36%, which is recorded as SiPA-10 (10 represents the mass ratio of PDMS to the mixed monomer solution).

[0114] Example 2

[0115] A method for preparing an aqueous high-content silicone-modified acrylate dispersion comprises the following steps:

[0116] 3.544 g of triethylamine (the molar ratio of the amine group in the triethylamine to the carboxyl group in the water-based high-content silicone-modified acrylate resin is 1:1) was added to 100 g of the water-based high-content silicone-modified acrylate resin of Example 1, and the mixture was stirred at 25° C. and 800 rpm to fully neutralize the mixture into salt for 1 h to obtain a neutralized resin;

[0117] In 100g of neutralized resin, 500g of water was added dropwise at a dropping speed of 20g / min under high-speed stirring (1000rpm). After the addition was completed, high-speed stirring (1000rpm) was performed for 30min, then low-speed stirring (100rpm) was switched to defoaming for 1.5h. Then, the mixed solvent in the dispersion was removed by reduced pressure evaporation at 60°C using a rotary evaporator to obtain an aqueous high-content silicone-modified acrylate dispersion with a solid content of 25wt%, which was named WSiPA-10.

[0118] Example 3

[0119] The mass of PDMS in Example 1 was adjusted to 2.5 g, and the other conditions were kept consistent with Examples 1 and 2 to obtain an aqueous high-content silicone-modified acrylate dispersion named WSiPA-5.

[0120] Example 4

[0121] The mass of PDMS in Example 1 was adjusted to 7.5 g, and the other conditions were kept consistent with Examples 1 and 2 to obtain an aqueous high-content silicone-modified acrylate dispersion named WSiPA-15.

[0122] Comparative Example 1

[0123] The mass of PDMS in Example 1 was adjusted to 0 g, and the other components were kept consistent with Examples 1 and 2 to obtain an aqueous high-content silicone-modified acrylate dispersion, which was named WSiPA-0.

[0124] The amount of each monomer used in the water-based high-content silicone-modified acrylate dispersion is shown in Table 1.

[0125] Table 1

[0126]

[0127] Example 5

[0128] A method for preparing a water-based anti-fouling coating comprises the following steps:

[0129] 20g of the aqueous high-content silicone-modified acrylate dispersion of Examples 2, 3, 4 and Comparative Example 1, 0.1g of aziridine crosslinker (accounting for 2wt% of the pure resin), and 1.27g of aqueous isocyanate curing agent (calculated as nNCO:nOH=1.1) were stirred at 250rpm for 30min, and then 5g of cosolvent, 0.18g of defoamer, 0.375g of wetting agent and 0.025g of thickener were added thereto, and stirred at 250rpm for 20min. After stirring evenly, the mixture was placed in a vacuum drying oven at 25°C and vacuumed for 1h to eliminate bubbles generated by stirring, thereby obtaining an aqueous high-content silicone-modified acrylate stain-resistant coating, which was named WSiPA-10-C, WSiPA-5-C, WSiPA-15-C, and WSiPA-0-C.

[0130] Example 6

[0131] A method for preparing a water-based anti-fouling coating comprises the following steps:

[0132] Use a coating rod to scrape the coating WSiPA-10-C, WSiPA-5-C, WSiPA-15-C, and WSiPA-0-C onto the surface of the PET film treated with the polyurethane primer, dry it at room temperature for 1 hour, and then cure it at high temperature (80°C, 30 min; 140°C, 30 min) to ensure that the curing reaction of the water-based curing agent is complete to form an excellent stain-resistant coating with a coating thickness of 15 μm.

[0133] The obtained coating was subjected to performance test, and the test results are as follows:

[0134] Figure 1 The water absorption test results of the coatings formed by WSiPA-10-C, WSiPA-5-C, WSiPA-15-C, and WSiPA-0-C. Figure 1It can be seen that: with the extension of the immersion time of the coating, the water absorption rate shows a trend of gradual increase, and slightly decreases after reaching the maximum adsorption amount, and then fluctuates slightly; and with the increase of the hydrophobic PDMS content, the water absorption rate of the coating decreases accordingly; at 120h, the water absorption rate of the WSiPA-0-C coating decreases from 32.7% to 22.6% of the WSiPA-15-C coating, which means that the WSiPA-PDMS coating with a high silicone content is more water resistant.

[0135] Figure 2 The stress-strain curves of the coatings WSiPA-10-C, WSiPA-5-C, WSiPA-15-C, and WSiPA-0-C. Figure 2 It can be seen that: with the increase of PDMS content, the Young's modulus and elongation at break of the coating show a trend of first increasing and then decreasing. When the PDMS content increases to 10wt%, the Young's modulus of the coating is 1.14MPa, and the elongation at break is 161%; the PDMS content of the silicone prepolymer introduced into the polymer structure has a certain reinforcing effect on the coating, and the appropriate addition improves the mechanical properties of the film, but the compatibility of PDMS and acrylate is limited, and excessive PDMS addition will have a negative impact on the mechanical properties of the coating.

[0136] Figure 3 The static water contact angle bar graph and digital photos of the coatings formed by coatings WSiPA-10-C, WSiPA-5-C, WSiPA-15-C, and WSiPA-0-C. Figure 3 It can be seen that the water contact angles of the coatings are all over 90°, indicating that the coatings are hydrophobic and the higher the PDMS content in the coatings, the larger the contact angle and the stronger its hydrophobicity. The contact angle of the WSiPA-15-C coating is 116.8° and it is the most hydrophobic. The reason is that the use of a high content of silicone-modified acrylate makes it easier for the coating surface to accumulate low surface energy hydrophobic silicone.

[0137] Figure 4 The digital photos of the oil pen stain resistance of the coating formed by the coating WSiPA-10-C, WSiPA-5-C, WSiPA-15-C, and WSiPA-0-C, among which 1-3 are the results after oil pen staining, after dry paper towel wiping, and after alcohol cotton wiping. Figure 4 It can be seen that: with the increase of PDMS content, the stains of the oil pen on the coating surface are easier to wipe clean, and the high content of silicone-modified acrylate can give the coating a good decontamination effect; and with the increase of PDMS content, the solvent resistance of the coating is better, and the surface is not sticky after wiping back and forth with alcohol cotton swab 50 times.

[0138] Table 2 shows the test results of the coating. It can be seen from Table 2 that the PDMS content affects the hydrophobicity, stain resistance and water resistance of the coating. The higher the PDMS content, the stronger the hydrophobicity, stain resistance and water resistance of the coating, but the corresponding mechanics will decrease with the increase of PDMS content; therefore, the stain-resistant coating with the best comprehensive performance is WSiPA-10-C prepared by compounding and curing a high-content silicone-modified acrylate dispersion and various additives.

[0139] Table 2

[0140]

[0141] Comparative Example 2

[0142] The PDMS in Example 1 was adjusted to Shin-Etsu KE-1180 to prepare the coating, and the other conditions remained the same as in Example 1.

[0143] The results showed that the viscosity of the polymerization reaction increased rapidly during the insulation stage, resulting in violent polymerization. The polymerization reaction could not proceed smoothly, high-content silicone-modified acrylate polymers were difficult to prepare, and the polymerization reaction failed.

[0144] Comparative Example 3

[0145] If PDMS is not added during polymerization, it can be added during the preparation of the neutralized resin.

[0146] The results showed that the blending could not be successful.

[0147] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Anyone familiar with this technology can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the definition of the claims.

Claims

1. A method for preparing a water-based high-content silicone-modified acrylate resin, characterized in that: The steps include: (1) mixing an organosilicon acrylate monomer, a hydroxyl-containing acrylate monomer, a carboxyl acrylate monomer, and other acrylate monomers, adding a chain transfer agent, and then adding an organosilicon prepolymer and mixing them uniformly to obtain a mixed monomer; (2) mixing the initiator and the mixed solvent uniformly to obtain an initiator solution; (3) Firstly, a solvent is added to the reaction container for reflux, and then an initiator solution and a mixed monomer solution are added dropwise to carry out polymerization. After the polymerization is completed, a water-based high-content silicone-modified acrylate resin is obtained.

2. The method according to claim 1, characterized in that The mass ratio of the silicone acrylate monomer, the hydroxyl-containing acrylate monomer, the carboxyl acrylate monomer, the other acrylate monomers, the chain transfer agent and the silicone prepolymer is 40-70:2-5:3-10:10-40:1-5:5-15.

3. The method according to claim 1, characterized in that The silicone acrylate monomer is one or two of methacrylate-terminated polydimethylsiloxane (PDMS-MA) and acrylate-terminated polydimethylsiloxane with a functionality of 1 and a molecular weight of 1000-8000; the hydroxyl-containing acrylate monomer is one or more of hydroxyethyl acrylate (2-HEA), hydroxyethyl methacrylate (HEMA), and hydroxypropyl acrylate (HPA); the carboxyl acrylate monomer is one or two of acrylic acid (AA) and methacrylic acid (MAA); the other acrylate monomers are One or more of methyl methacrylate (MMA), methyl acrylate (MA), ethyl acrylate (EA), butyl methacrylate (BMA), butyl acrylate (BA), isooctyl methacrylate (EHMA), and isooctyl acrylate (2-EHA); the chain transfer agent is one or more of dodecyl mercaptan, mercaptoethanol, thioglycolic acid, and isooctyl 3-mercaptopropionate; the silicone prepolymer (PDMS) is one or more of Dow Corning Sylgard-184, Dow Corning MDX4-4210, and Kraft K-5318W.

4. A water-based high-content silicone-modified acrylate resin prepared by the method according to any one of claims 1 to 3.

5. A method for preparing an aqueous high-content silicone-modified acrylate dispersion, characterized in that: The steps include: Adding a neutralizing agent to the water-based high-content silicone-modified acrylate resin of claim 4, mixing and stirring to fully neutralize into a salt, to obtain a neutralized resin; Water is added dropwise to the neutralized resin for high-speed shear emulsification. After the addition is complete, the mixture is stirred at a low speed for defoaming. The mixed solvent in the resin is removed by rotary evaporation to obtain a water-based high-content silicone-modified acrylate dispersion.

6. Aqueous high-content silicone-modified acrylate dispersion prepared by the method of claim 5.

7. A water-based anti-fouling coating, characterized in that: Its components include the aqueous high-content silicone-modified acrylate dispersion as claimed in claim 6, a crosslinking agent, a curing agent, a cosolvent, a defoamer, a wetting agent, and a thickener; Among them, the mass ratio of water-based high-content silicone-modified acrylate dispersion, crosslinking agent, curing agent, co-solvent, defoaming agent, wetting agent and thickener is 70-90: 0.3-0.6: 4-7: 15-25: 0.6-0.8: 1-2: 0.05-0.

15.

8. A method for preparing a water-based anti-fouling coating, characterized in that: The steps include: The aqueous high-content silicone-modified acrylate dispersion, crosslinking agent, and curing agent described in claim 6 are stirred and mixed uniformly, and then a cosolvent, defoaming agent, wetting agent, and thickener are added, and the mixing is continued to be uniform, and bubbles are removed to obtain a water-based stain-resistant coating.

9. A water-based anti-fouling coating, characterized in that: The water-based anti-fouling coating according to claim 7 is adopted.

10. Use of the water-based high-content silicone-modified acrylate resin according to claim 4, the water-based high-content silicone-modified acrylate dispersion according to claim 6, and the water-based anti-fouling coating according to claim 7 in the field of anti-fouling treatment.

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