Stain-resistant emulsion, stain-resistant coating as well as preparation method and application of stain-resistant emulsion and stain-resistant coating

Abstract

The invention belongs to the technical field of coatings, and particularly relates to a stain-resistant emulsion, a stain-resistant coating as well as a preparation method and application of the stain-resistant emulsion and the stain-resistant coating. The stain-resistant emulsion is prepared from the following raw materials: methyl methacrylate, n-butyl acrylate, 2-ethylhexyl acrylate, methacrylic acid, an anionic emulsifier, a nonionic emulsifier, a crosslinking monomer, an initiator, a neutralizer and water. The crosslinking monomer comprises a diacetone acrylamide / adipic acid dihydrazine system and vinyl triethoxy silane. According to the invention, the anionic emulsifier and the nonionic emulsifier are compounded for use, so that the hydrophilic-lipophilic balance is controlled, and the stain resistance of the emulsion is improved; a specific diacetone acrylamide / adipic acid dihydrazine system and vinyltriethoxysilane are adopted as cross-linking monomers, and other components are combined to act together, so that the film forming density of the emulsion is greatly improved, and the paint is ensured to have good stain resistance.

Description

Technical Field

[0001] This invention belongs to the field of coating technology, and specifically relates to a stain-resistant emulsion, a stain-resistant coating, a preparation method thereof, and its application. Background Technology

[0002] Wall paint refers to coatings used on building walls for both decoration and protection. It makes building walls aesthetically pleasing and clean, while also protecting them and extending their lifespan. Wall paints are broadly classified into interior and exterior wall paints. Interior wall paints emphasize decoration and environmental friendliness, while exterior wall paints emphasize protection and durability. In addition to their decorative and protective functions, wall paints are also developing towards a wider variety of styles, fashionable designs, and a healthier, more environmentally friendly approach.

[0003] Currently, interior wall paints are widely used, but commercially available interior wall paints are easily stained. Once the wall surface is stained with tea stains, soy sauce, juice, etc., it is difficult to clean. These existing wall paints usually use acrylic emulsions as film-forming materials. This type of coating easily allows dirt to penetrate, and even with wiping or cleaning, stains or marks will still be left on the wall surface.

[0004] Therefore, it is of great significance to provide an emulsion that enables wall paint to have good stain resistance. Summary of the Invention

[0005] The present invention aims to solve one or more technical problems existing in the prior art, and at least provide a beneficial alternative. Specifically, the present invention provides a stain-resistant emulsion, wherein the coating prepared therefrom has good stain resistance properties.

[0006] The inventive concept of this invention: The raw materials for preparing the coating of this invention include methyl methacrylate, n-butyl acrylate, isooctyl acrylate, methacrylic acid, anionic emulsifier, nonionic emulsifier, crosslinking monomer, initiator, neutralizer, and water; the crosslinking monomer includes a diacetone acrylamide / dihydrazine adipate system and vinyltriethoxysilane. This invention, by using a combination of anionic and nonionic emulsifiers, controls the hydrophilic-lipophilic balance, thereby improving the stain resistance of the emulsion; by using a specific diacetone acrylamide / dihydrazine adipate system and vinyltriethoxysilane as crosslinking monomers, combined with the synergistic effect of other components, the film density of the emulsion is greatly improved, ensuring that the coating has excellent stain resistance.

[0007] Therefore, a first aspect of the present invention provides a stain-resistant emulsion.

[0008] Specifically, the raw materials for preparing the stain-resistant emulsion include methyl methacrylate, n-butyl acrylate, isooctyl acrylate, methacrylic acid, anionic emulsifier, nonionic emulsifier, crosslinking monomer, initiator, neutralizer, and water;

[0009] The crosslinking monomers include the diacetone acrylamide / dihydrazine adipate system and vinyltriethoxysilane.

[0010] Preferably, the particle size of the emulsion is 65-95 nm; more preferably, the particle size of the emulsion is 70-90 nm.

[0011] Preferably, the anionic emulsifier comprises sodium sulfosuccinate monoester.

[0012] Preferably, the nonionic emulsifier includes alkyl polyoxyethylene ether.

[0013] Preferably, in the crosslinking monomer, the mass ratio of the diacetone acrylamide / dihydrazine adipate system to vinyltriethoxysilane is (1.5-2.5):1; more preferably, in the crosslinking monomer, the mass ratio of the diacetone acrylamide / dihydrazine adipate system to vinyltriethoxysilane is (1.8-2.2):1; even more preferably, in the crosslinking monomer, the mass ratio of the diacetone acrylamide / dihydrazine adipate system to vinyltriethoxysilane is 2:1.

[0014] Preferably, in the diacetone acrylamide / dihydrazine adipic acid system, the mass ratio of diacetone acrylamide to dihydrazine adipic acid is 1:(0.8-1.2); more preferably, in the diacetone acrylamide / dihydrazine adipic acid system, the mass ratio of diacetone acrylamide to dihydrazine adipic acid is 1:(0.9-1.1); even more preferably, in the diacetone acrylamide / dihydrazine adipic acid system, the mass ratio of diacetone acrylamide to dihydrazine adipic acid is 1:1.

[0015] Specifically, the diacetone acrylamide / dihydrazine adipic acid system is a mixture of diacetone acrylamide and dihydrazine adipic acid.

[0016] Preferably, the raw materials for preparing the emulsion, by weight, include 40-60 parts of methyl methacrylate, 20-40 parts of n-butyl acrylate, 20-40 parts of isooctyl acrylate, 0.2-4 parts of methacrylic acid, 0.8-2 parts of anionic emulsifier, 0.6-1 parts of nonionic emulsifier, 0.3-1 parts of crosslinking monomer, 0.2-0.7 parts of initiator, 9-11 parts of neutralizer, and 80-120 parts of water.

[0017] Preferably, the initiator comprises sodium persulfate.

[0018] Preferably, the neutralizing agent comprises sodium hydroxide.

[0019] More preferably, the neutralizing agent comprises a sodium hydroxide solution.

[0020] Preferably, the sodium hydroxide solution has a mass fraction of 4-6%; more preferably, the sodium hydroxide solution has a mass fraction of 4.5-5.5%; and even more preferably, the sodium hydroxide solution has a mass fraction of 5%.

[0021] A second aspect of the present invention provides a method for preparing the stain-resistant emulsion described in the first aspect of the present invention.

[0022] Specifically, the method for preparing the stain-resistant emulsion includes the following steps:

[0023] The raw materials are mixed and subjected to semi-continuous emulsion polymerization to obtain the emulsion.

[0024] Preferably, the method for preparing the stain-resistant emulsion includes the following steps:

[0025] (1) Mix a portion of methyl methacrylate, n-butyl acrylate, isooctyl acrylate, methacrylic acid, anionic emulsifier and water to obtain preemulsion A;

[0026] The crosslinking monomer, a portion of water, a portion of anionic emulsifier, and the remainder of methyl methacrylate, n-butyl acrylate, isooctyl acrylate, and methacrylic acid are mixed to obtain pre-emulsion B.

[0027] (2) Mix the remaining anionic emulsifier and the remaining water, heat up, add part of the pre-emulsion A and part of the initiator, and keep warm; then add the remaining pre-emulsion A and the remaining initiator, and finally add the pre-emulsion B, neutralizer and nonionic emulsifier to obtain the emulsion.

[0028] Preferably, in step (1), during the preparation of preemulsion A, the amounts of methyl methacrylate, n-butyl acrylate, isooctyl acrylate, methacrylic acid, anionic emulsifier, and water are respectively 20-30 parts of methyl methacrylate, 10-20 parts of n-butyl acrylate, 10-20 parts of isooctyl acrylate, 0.1-2 parts of functional monomer, 0.1-0.5 parts of anionic emulsifier, and 10-20 parts of water.

[0029] Specifically, in step (1), the portion of methyl methacrylate, n-butyl acrylate, isooctyl acrylate, methacrylic acid, anionic emulsifier and water refers to the portion of methyl methacrylate, the portion of n-butyl acrylate, the portion of isooctyl acrylate, the portion of methacrylic acid, the portion of anionic emulsifier and water; the remainder of methyl methacrylate, n-butyl acrylate, isooctyl acrylate and methacrylic acid refers to the remainder of methyl methacrylate, the remainder of n-butyl acrylate, the remainder of isooctyl acrylate and the remainder of methacrylic acid.

[0030] Preferably, in step (1), during the preparation of the pre-emulsion B, the amounts of water and anionic emulsifier are 10-20 parts water and 0.1-0.5 parts anionic emulsifier, respectively.

[0031] Preferably, in step (1), the portion of preemulsion A accounts for 4-6% of the total amount of preemulsion A; more preferably, the portion of preemulsion A accounts for 4.5-5.5% of the total amount of preemulsion A; even more preferably, the portion of preemulsion A accounts for 5% of the total amount of preemulsion A.

[0032] Preferably, in step (2), the temperature after heating is 80-90℃; more preferably, in step (2), the temperature after heating is 86-88℃.

[0033] Preferably, in step (2), the heat preservation time is 2-4 hours; more preferably, the heat preservation time is 2.5-3.5 hours; and even more preferably, the heat preservation time is 3 hours.

[0034] Preferably, in step (2), the dripping time of the remaining preemulsion A is 55-130 min; more preferably, the dripping time of the remaining preemulsion A is 60-120 min.

[0035] Preferably, in step (2), after the remaining amount of preemulsion A has been added, the preemulsion B is added, and at this time the remaining amount of initiator has not been added.

[0036] Preferably, in step (2), the dripping time of the preemulsion B is 55-130 min; more preferably, the dripping time of the preemulsion B is 60-120 min.

[0037] Preferably, in step (2), the remaining initiator is added 25-35 minutes later than the pre-emulsion B; more preferably, the remaining initiator is added 27-33 minutes later than the pre-emulsion B; and even more preferably, the remaining initiator is added 30 minutes later than the pre-emulsion B.

[0038] A third aspect of the present invention provides a stain-resistant coating.

[0039] Specifically, the stain-resistant coating includes fillers and the stain-resistant emulsion described in the first aspect of the present invention;

[0040] The filler includes 750-850 mesh calcium carbonate and 1200-1300 mesh calcium carbonate.

[0041] Preferably, the calcium carbonate includes 800-mesh calcium carbonate and 1250-mesh calcium carbonate.

[0042] Preferably, the mass ratio of the 750-850 mesh calcium carbonate to the 1200-1300 mesh calcium carbonate is 1:(0.8-1.2); more preferably, the mass ratio of the 750-850 mesh calcium carbonate to the 1200-1300 mesh calcium carbonate is 1:(0.9-1.1); even more preferably, the mass ratio of the 750-850 mesh calcium carbonate to the 1200-1300 mesh calcium carbonate is 1:1.

[0043] Preferably, the stain-resistant coating further includes additives, cellulose, pigments, and water.

[0044] Preferably, by weight, the stain-resistant coating comprises 20-32 parts emulsion, 3-6.5 parts additives, 20-25 parts pigment, 15-30 parts filler, 0.2-0.5 parts cellulose and 15-30 parts water.

[0045] Preferably, the additives include at least one of dispersants, wetting agents, defoamers, pH adjusters, antifreeze agents, film-forming aids, leveling agents, thickeners, and bactericides.

[0046] More preferably, the additives include dispersants, wetting agents, defoamers, pH adjusters, antifreeze agents, film-forming aids, leveling agents, thickeners, and bactericides.

[0047] Preferably, by weight, the stain-resistant coating comprises 20-32 parts of stain-resistant emulsion, 0.4-0.6 parts of dispersant, 0.1-0.2 parts of wetting agent, 0.1-0.3 parts of defoamer, 0.1-0.3 parts of pH adjuster, 1-2 parts of antifreeze, 1-2 parts of film-forming aid, 0.1-0.3 parts of leveling agent, 0.1-0.3 parts of thickener, 0.1-0.5 parts of bactericide, 20-25 parts of pigment, 15-30 parts of filler, 0.2-0.5 parts of cellulose, and 15-30 parts of water.

[0048] Preferably, the dispersant comprises a sodium polycarboxylate dispersant.

[0049] Preferably, the wetting agent comprises alkyl polyoxyethylene ether.

[0050] Preferably, the defoamer includes a mineral oil-based defoamer.

[0051] Specifically, the defoamer includes NOPCO NXZ defoamer.

[0052] Preferably, the cellulose comprises hydroxyethyl cellulose.

[0053] Specifically, the cellulose includes Ashland hydroxyethyl cellulose NATROSOL 250HBR.

[0054] Preferably, the pH adjuster comprises sodium hydroxide.

[0055] Preferably, the sodium hydroxide has a mass fraction of 1.5-2.5%; more preferably, the sodium hydroxide has a mass fraction of 1.8-2.2%; and preferably, the sodium hydroxide has a mass fraction of 2%.

[0056] Preferably, the pigment includes titanium dioxide.

[0057] Preferably, the titanium dioxide includes rutile titanium dioxide.

[0058] Preferably, the antifreeze agent comprises propylene glycol.

[0059] Preferably, the film-forming aid includes alcohol ester film-forming aids.

[0060] Specifically, the film-forming aid includes Dow Coasol 290Plus.

[0061] Preferably, the leveling agent comprises an associative polyurethane leveling agent.

[0062] Specifically, the leveling agent includes Rohm and Haas leveling agent RM-2020.

[0063] Preferably, the thickener is an alkali-swellable anionic thickener.

[0064] Preferably, the bactericide comprises a fast-acting, highly effective, broad-spectrum bactericide; more preferably, the bactericide comprises 1,2-benzisothiazolin-3-one.

[0065] A fourth aspect of the present invention provides a method for preparing the stain-resistant coating described in the third aspect of the present invention.

[0066] Specifically, the method for preparing the stain-resistant coating includes the following steps:

[0067] The components of the coating are mixed to obtain the stain-resistant coating.

[0068] Preferably, a portion of water, dispersant, wetting agent, and defoamer are first mixed, then cellulose and pH adjuster are added and dispersed; then titanium dioxide and calcium carbonate are added and dispersed at high speed; finally, the remaining defoamer, antifreeze, film-forming aid, stain-resistant emulsion, bactericide, thickener, leveling agent, and remaining water are added and stirred to obtain the stain-resistant coating.

[0069] Preferably, the portion of water accounts for 75-90% of the total water usage; more preferably, the portion of water accounts for 80-85% of the total water usage.

[0070] Preferably, the portion of the defoamer accounts for 22-33% of the total amount of defoamer used; more preferably, the portion of the defoamer accounts for 25-30% of the total amount of defoamer used.

[0071] Preferably, the dispersion rotation speed is 350-650 r / min and the dispersion time is 1.5-2.5 min; more preferably, the dispersion rotation speed is 400-600 r / min and the dispersion time is 1.8-2.2 min.

[0072] Preferably, the high-speed dispersion rotation speed is 1100-1500 r / min, and the high-speed dispersion time is 10-20 min; more preferably, the high-speed dispersion rotation speed is 1200-1400 r / min, and the high-speed dispersion time is 13-17 min.

[0073] Preferably, the stirring speed is 750-1100 r / min and the stirring time is 8-12 min; more preferably, the stirring speed is 800-1000 r / min and the stirring time is 9-11 min.

[0074] The fifth aspect of the present invention provides the application of the stain-resistant emulsion described in the first aspect of the present invention or the stain-resistant coating described in the third aspect of the present invention on building walls.

[0075] Compared with the prior art, the beneficial effects of the technical solution provided by the present invention are as follows:

[0076] (1) This invention uses anionic and nonionic emulsifiers in combination to control the hydrophilic-lipophilic balance and improve the stain resistance of the emulsion; it uses a specific diacetone acrylamide / dihydrazine adipate system and vinyltriethoxysilane as crosslinking monomers, and works together with other components to greatly improve the film density of the emulsion and ensure that the coating has good stain resistance.

[0077] (2) The coating of the present invention uses calcium carbonate of different mesh sizes in combination, and the components in the coating work together to make the coating have good stain resistance.

[0078] (3) The preparation process of this invention is simple and easy to apply in industrial applications. Detailed Implementation

[0079] To enable those skilled in the art to more clearly understand the technical solutions described in this invention, the following embodiments are provided for illustration. It should be noted that the following embodiments do not constitute a limitation on the scope of protection claimed by this invention.

[0080] Unless otherwise specified, the raw materials, reagents or devices used in the following examples are available from conventional commercial sources or can be obtained by existing known methods.

[0081] The sources of the relevant raw materials in the embodiments of the present invention are as follows:

[0082] Anionic emulsifier AEROSOL 501: purchased from Solvay;

[0083] Nonionic emulsifier LCN407: purchased from Clariant;

[0084] Dispersant AD504: purchased from Sannopco;

[0085] Wetting agent LCN-407: purchased from Clariant;

[0086] Defoamer NXZ: Purchased from Sannopco;

[0087] Hydroxyethyl cellulose NATROSOL 250HBR: purchased from Ashland;

[0088] Titanium dioxide R706: purchased from Chemours;

[0089] Coasol 290 Plus, a film-forming aid, was purchased from Dow Chemical.

[0090] Leveling agent RM2020: purchased from Rohm and Haas;

[0091] Thickener ASE-60: purchased from Rohm and Haas.

[0092] Example 1

[0093] This embodiment provides a stain-resistant emulsion and its preparation method, and a stain-resistant coating and its preparation method, specifically:

[0094] A stain-resistant emulsion, by weight, is composed of the following raw materials: 49.2 parts methyl methacrylate, 23.8 parts n-butyl acrylate, 25 parts isooctyl acrylate, 2 parts methacrylic acid, 1.4 parts anionic emulsifier AEROSOL 501, 1 part nonionic emulsifier LCN407, 0.1 parts crosslinking monomer vinyltriethoxysilane, 0.2 parts crosslinking monomer diacetone acrylamide / diazid adipic acid (the mass ratio of diacetone acrylamide and dizid adipic acid is 1:1), 0.5 parts sodium persulfate initiator, 10 parts sodium hydroxide solution with a mass fraction of 10% neutralizing agent, and 96 parts water.

[0095] The method for preparing the above-mentioned stain-resistant emulsion includes the following steps:

[0096] (1) Mix 0.4 parts of anionic emulsifier AEROSOL 501, 14 parts of water, 24.6 parts of methyl methacrylate, 11.9 parts of n-butyl acrylate, 12.5 parts of isooctyl acrylate and 1 part of methacrylic acid to obtain pre-emulsion A;

[0097] Pre-emulsion B was obtained by mixing 0.4 parts of anionic emulsifier AEROSOL 501, 14 parts of water, 24.6 parts of methyl methacrylate, 11.9 parts of n-butyl acrylate, 12.5 parts of isooctyl acrylate, 1 part of methacrylic acid, 0.1 parts of vinyltriethoxysilane, and 0.2 parts of diacetone acrylamide / diazid adipic acid (the mass ratio of diacetone acrylamide to dizid adipic acid is 1:1).

[0098] (2) Add 68 parts of water and 0.6 parts of anionic emulsifier AEROSOL 501 to the reactor. After the temperature reaches 86-88℃, pour 5% of the total amount of preemulsion A into the reactor and pour 0.1 parts of initiator into the reactor. Keep warm for 30 minutes. Then add the remaining preemulsion A and the remaining initiator dropwise. The dropwise addition time of the remaining preemulsion A is controlled at 90 minutes. After the dropwise addition of the remaining preemulsion A is completed, add preemulsion B dropwise. The dropwise addition time of preemulsion B is controlled at 90 minutes. The remaining initiator is added 30 minutes later than preemulsion B. Finally, add 10 parts of neutralizer and 1 part of nonionic emulsifier LCN407 to obtain a stain-resistant emulsion.

[0099] A stain-resistant coating, by weight, comprises the following components: 32 parts stain-resistant emulsion, 0.5 parts dispersant AD504, 0.1 parts wetting agent LCN-407, 0.2 parts defoamer NXZ, 0.4 parts hydroxyethyl cellulose NATROSOL 250HBR, 0.2 parts pH adjuster (2% NaOH by mass), 25 parts titanium dioxide R706, 10 parts calcium carbonate 1250 mesh, 10 parts calcium carbonate 800 mesh, 1 part antifreeze propylene glycol, 2 parts film-forming aid Coasol 290Plus, 0.1 parts leveling agent RM2020, 0.2 parts thickener ASE-60, 0.2 parts bactericide 1,2-benzisothiazolin-3-one (BIT), and 18.1 parts water.

[0100] The method for preparing the above-mentioned stain-resistant coating includes the following steps:

[0101] First, add 82% of the total amount of water, dispersant, wetting agent, and 28% of the total amount of defoamer to the reactor. Then add cellulose and pH adjuster and disperse at 500 r / min for 2 min. Next, add titanium dioxide and calcium carbonate and disperse at 1300 r / min for 15 min. Finally, add the remaining defoamer, antifreeze, film-forming aid, stain-resistant emulsion, bactericide, thickener, leveling agent, and the remaining water. Stir at 900 r / min for 10 min to obtain a stain-resistant coating.

[0102] Example 2

[0103] This embodiment provides a stain-resistant emulsion and its preparation method, specifically:

[0104] A stain-resistant emulsion, by weight, is composed of the following raw materials: 49.2 parts methyl methacrylate, 23.8 parts n-butyl acrylate, 25 parts isooctyl acrylate, 2 parts methacrylic acid, 1.6 parts anionic emulsifier AEROSOL 501, 0.6 parts nonionic emulsifier LCN407, 0.3 parts crosslinking monomer vinyltriethoxysilane, 0.6 parts crosslinking monomer diacetone acrylamide / diazid adipic acid (the mass ratio of diacetone acrylamide and dizid adipic acid is 1:1), 0.5 parts sodium persulfate initiator, 10 parts sodium hydroxide solution with a mass fraction of 10% and water, respectively.

[0105] The method for preparing the above-mentioned stain-resistant emulsion includes the following steps:

[0106] (1) Mix 0.4 parts of anionic emulsifier AEROSOL 501, 14 parts of water, 24.6 parts of methyl methacrylate, 11.9 parts of n-butyl acrylate, 12.5 parts of isooctyl acrylate and 1 part of methacrylic acid to obtain pre-emulsion A;

[0107] Pre-emulsion B was obtained by mixing 0.4 parts of anionic emulsifier AEROSOL 501, 14 parts of water, 24.6 parts of methyl methacrylate, 11.9 parts of n-butyl acrylate, 12.5 parts of isooctyl acrylate, 1 part of methacrylic acid, 0.3 parts of vinyltriethoxysilane, and 0.6 parts of diacetone acrylamide / diazid adipic acid (the mass ratio of diacetone acrylamide to dizid adipic acid is 1:1).

[0108] (2) Add 68 parts of water and 0.8 parts of anionic emulsifier AEROSOL 501 to the reactor. After the temperature reaches 86-88℃, pour 5% of the total amount of preemulsion A into the reactor and pour 0.1 parts of initiator into the reactor. Keep warm for 30 minutes. Then add the remaining preemulsion A and the remaining initiator dropwise. The dropwise addition time of the remaining preemulsion A is controlled at 60 minutes. After the dropwise addition of the remaining preemulsion A is completed, add preemulsion B dropwise. The dropwise addition time of preemulsion B is controlled at 60 minutes. The remaining initiator is added 30 minutes later than preemulsion B. Finally, add 10 parts of neutralizer and 0.6 parts of nonionic emulsifier LCN407 to obtain a stain-resistant emulsion.

[0109] This embodiment also provides a stain-resistant coating. The stain-resistant coating of Example 2 differs from that of Example 1 only in that it uses the stain-resistant emulsion prepared in Example 2, and is otherwise the same as that of Example 1.

[0110] Comparative Example 1

[0111] The only difference between Comparative Example 1 and Example 2 is that Comparative Example 1 uses an equal amount of diacetone acrylamide / dihydrazine adipic acid to replace vinyltriethoxysilane, i.e. it does not contain vinyltriethoxysilane. Otherwise, it is the same as Example 2.

[0112] Comparative Example 2

[0113] The only difference between Comparative Example 2 and Example 2 is that Comparative Example 2 uses an equal amount of vinyltriethoxysilane to replace diacetone acrylamide / dihydrazide adipate, i.e. it does not contain diacetone acrylamide / dihydrazide adipate. Otherwise, it is the same as Example 2.

[0114] Comparative Example 3

[0115] The only difference between Comparative Example 3 and Example 1 is that Comparative Example 3 uses an equal amount of anionic emulsifier AEROSOL501 to replace nonionic emulsifier LCN407, i.e. it does not contain nonionic emulsifier LCN407. Otherwise, it is the same as Example 1.

[0116] Comparative Example 4

[0117] The only difference between Comparative Example 4 and Example 1 is that Comparative Example 4 uses an equal amount of nonionic emulsifier LCN407 to replace anionic emulsifier AEROSOL 501, that is, it does not contain anionic emulsifier AEROSOL 501. Otherwise, it is the same as Example 1.

[0118] Comparative Example 5

[0119] The only difference between Comparative Example 5 and Example 1 is that in the coating of Comparative Example 5, an equal amount of 1250 mesh calcium carbonate is used to replace 800 mesh calcium carbonate; otherwise, they are the same as in Example 1.

[0120] Comparative Example 6

[0121] The only difference between Comparative Example 6 and Example 1 is that in the coating of Comparative Example 6, an equal amount of 800-mesh calcium carbonate is used instead of 1250-mesh calcium carbonate; otherwise, they are the same as in Example 1.

[0122] Performance testing

[0123] According to GB / T 9780-2013 "Test Method for Stain Resistance of Architectural Coatings", the stain resistance of the coatings prepared in Examples 1-2 and Comparative Examples 1-6 was tested, and the test results are shown in Table 1.

[0124] Table 1: Performance test results of coatings from Examples 1-2 and Comparative Examples 1-6

[0125]

[0126] As can be seen from Table 1, the coating of the present invention has good stain resistance.

[0127] Comparative Example 1 used an equal amount of diacetone acrylamide / dihydrazine adipate to replace vinyltriethoxysilane, i.e., it contained no vinyltriethoxysilane. Comparative Example 2 used an equal amount of vinyltriethoxysilane to replace diacetone acrylamide / dihydrazine adipate, i.e., it contained no diacetone acrylamide / dihydrazine adipate. This resulted in Comparative Examples 1 and 2 having inferior stain resistance compared to Example 2. This demonstrates that the crosslinking monomers vinyltriethoxysilane and diacetone acrylamide / dihydrazine adipate both play important roles in this invention, and their synergistic effect is necessary to achieve good stain resistance.

[0128] In Comparative Example 3, an equal amount of anionic emulsifier AEROSOL 501 was used to replace the nonionic emulsifier LCN407. In Comparative Example 4, an equal amount of nonionic emulsifier LCN407 was used to replace the anionic emulsifier AEROSOL 501. The stain resistance of the coatings in Comparative Examples 3 and 4 was worse than that in Example 1. This demonstrates that a good stain resistance effect can only be achieved through the synergistic effect of anionic and nonionic emulsifiers in this invention.

[0129] In Comparative Example 5, an equal amount of 1250-mesh calcium carbonate replaced 800-mesh calcium carbonate. In Comparative Example 6, an equal amount of 800-mesh calcium carbonate replaced 1250-mesh calcium carbonate. This resulted in both Comparative Example 5 and 6 exhibiting inferior stain resistance compared to Example 1. This demonstrates that the 1250-mesh and 800-mesh calcium carbonate work synergistically to achieve good stain resistance in this invention.

[0130] In summary, this invention improves the stain resistance of the emulsion by using a combination of anionic and nonionic emulsifiers to control the hydrophilic-lipophilic balance. The specific diacetone-acrylamide / dihydrazine adipic acid system and vinyltriethoxysilane as crosslinking monomers, combined with other components, significantly enhance the film density of the emulsion, ensuring excellent stain resistance. Furthermore, the use of calcium carbonate of different mesh sizes in the coating further improves its stain resistance.

[0131] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. An emulsion characterized in that, The preparation raw materials of the emulsion include methyl methacrylate, n-butyl acrylate, isooctyl acrylate, methacrylic acid, an anionic emulsifier, a non-ionic emulsifier, a crosslinking monomer, an initiator, a neutralizing agent and water; The crosslinking monomer includes a diacetone acrylamide / adipic acid dihydrazine system and vinyl triethoxy silane.

2. The emulsion of claim 1, wherein, The anionic emulsifier includes a sodium salt of a sulfosuccinic acid monoester; and / or, the non-ionic emulsifier includes an alkyl polyoxyethylene ether.

3. The emulsion of claim 1, wherein, In the crosslinking monomer, the mass ratio of the diacetone acrylamide / adipic acid dihydrazine system and vinyl triethoxy silane is (1.5-2.5):1; and / or, in the diacetone acrylamide / adipic acid dihydrazine system, the mass ratio of diacetone acrylamide and adipic acid dihydrazine is 1:(0.8-1.2).

4. The emulsion of claim 1, wherein, The preparation raw materials of the emulsion include, by weight fraction, 40-60 parts of methyl methacrylate, 20-40 parts of n-butyl acrylate, 20-40 parts of isooctyl acrylate, 0.2-4 parts of methacrylic acid, 0.8-2 parts of an anionic emulsifier, 0.6-1 part of a non-ionic emulsifier, 0.3-1 part of a crosslinking monomer, 0.2-0.7 part of an initiator, 9-11 parts of a neutralizing agent and 80-120 parts of water.

5. Process for the preparation of an emulsion as claimed in any one of claims 1 to 4, characterized in that, The preparation method includes the following steps: The preparation raw materials are mixed, and the emulsion is prepared through semi-continuous emulsion polymerization.

6. The preparation method according to claim 5, characterized in that, The preparation method includes the following steps: (1) a part of methyl methacrylate, n-butyl acrylate, isooctyl acrylate, methacrylic acid, an anionic emulsifier and water are mixed to obtain a pre-emulsion A; a crosslinking monomer, a part of water, a part of an anionic emulsifier and the rest of methyl methacrylate, n-butyl acrylate, isooctyl acrylate and methacrylic acid are mixed to obtain a pre-emulsion B; (2) the rest of an anionic emulsifier and the rest of water are mixed, heated, a part of the pre-emulsion A and a part of an initiator are added, and then the rest of the pre-emulsion A and the rest of an initiator are added, finally, the pre-emulsion B, a neutralizing agent and a non-ionic emulsifier are added to prepare the emulsion.

7. The production method according to claim 6, wherein In the preparation of the pre-emulsion A in step (1), the use amounts of the part of methyl methacrylate, n-butyl acrylate, isooctyl acrylate, methacrylic acid, an anionic emulsifier and water are 20-30 parts of methyl methacrylate, 10-20 parts of n-butyl acrylate, 10-20 parts of isooctyl acrylate, 0.1-2 parts of methacrylic acid, 0.1-0.5 parts of an anionic emulsifier and 10-20 parts of water, respectively; and / or, in the preparation of the pre-emulsion B, the use amounts of the part of water and the part of an anionic emulsifier are 10-20 parts of water and 0.1-0.5 parts of an anionic emulsifier, respectively; and / or, the part of the pre-emulsion A accounts for 4-6% of the total amount of the pre-emulsion A; and / or, in step (2), the temperature after heating is 80-90℃; and / or, the time for heat preservation is 2-4h.

8. A coating characterized by, The coating includes a filler and the emulsion of any one of claims 1-4; The filler includes 750-850 mesh calcium carbonate and 1200-1300 mesh calcium carbonate.

9. The method of preparing a coating according to claim 8, characterized in that The method of preparation comprises the steps of: mixing the components of the coating to produce the coating.

10. Use of an emulsion as claimed in any of claims 1 to 4 or a coating as claimed in claim 8 in architectural wall finishes.

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