Water-based poly(meth)acrylic self-dulling resin and cover-free self-dulling multi-color paint

Abstract

Disclosed is a water-based poly(meth)acrylic self-mattifying resin and a self-mattifying multi-color coating without a topcoat. The resin comprises several micrometer poly(meth)acrylate resin particles generated in situ for mattifying effect, and also comprises small-particle-size resin particles for film forming. The refractive index of the micrometer resin particles and the small-particle-size resin particles generated in situ is consistent, and the mattifying paint film prepared therefrom has excellent transparency. The density of the micrometer particles and the small-particle-size emulsion generated in situ is substantially consistent, which can further prevent the sedimentation of large particles, and the resin has excellent storage stability. The resin is used in the preparation of coatings or adhesives as a mattifying coating or a mattifying topcoat with high transparency, smooth touch and storage stability, and is especially used in mattifying multi-color coating formulations, which eliminates the need for an additional mattifying topcoat process for achieving mattifying effect in traditional construction.

Description

TECHNICAL FIELD

[0001] The present invention relates to the field of preparing coatings, in particular to the field of matt topcoat coatings, more particularly to waterborne poly(meth)acrylate self-matt resin. BACKGROUND

[0002] The surface of a matt or flat coating can hide slight paint film defects, making the appearance uniform. Currently, matt or flat coatings are prepared by directly adding matting agents into the coating. The matting agent can make the paint film form a rough surface, which forms diffuse reflection when light is incident, and the paint film becomes matt or flat, thereby achieving the purpose of matting. The matting agent can provide matting while also imparting good resistance and good hand feeling to the paint film. The matting agent is mainly divided into inorganic matting agents such as silica or calcium carbonate, organic matting agents such as polymethyl urea, and liquid or solid polyethylene wax. When preparing matt or flat coatings, the inorganic matting agent of silica or calcium carbonate has poor compatibility with the resin, which can significantly reduce the transparency, water resistance, alcohol resistance, and wear resistance of the paint film. The organic matting agent of polymethyl urea has good compatibility with the resin, which does not significantly reduce the water resistance, alcohol resistance, and wear resistance of the paint film, but it can cause the paint film to be hazy and turbid due to the difference in refractive index between the resin and the matting agent, thereby reducing the transparency. The polyethylene wax matting agent is prone to migrate to the surface of the coating, which is easy to polish, and can also cause the problem of delamination instability when the finished coating is prepared.

[0003] To solve these problems, in recent years, vinyl polymer microspheres have been used as matting agents in coating compositions to provide a matte coating. Due to the excellent compatibility between the vinyl polymer microspheres and the film-forming resin, the water resistance, alcohol resistance, wear resistance, and other properties of the paint film can be significantly improved, and a special smooth hand feeling can be provided. For example, Japan Synthetic Chemical, Japan Sekisui Chemical, Microbeads AS, and other companies provide single-size thermosetting PMMA microsphere solid powder as products of various sizes, which can be used as matting agents. CN101037558A relates to a waterborne coating composition containing a polymerized matting agent component and a binder component, and a coated article prepared therefrom, the average particle size of the polymerized matting agent component is 1-20 um, and the waterborne composition can provide a matte coating with anti-polishing, flexibility, and feeling or touch properties. CN107531974A unexpectedly found that by selecting the appropriate combination of stabilizer type and stabilizer concentration and initiator type, suspension polymerization can be allowed to produce a storage-stable waterborne dispersion containing particles with an average particle size diameter of 1 micrometer to 30 micrometers, which can be used as a matting agent. Due to the very good compatibility of these vinyl polymer microspheres with the resin, especially the polyacrylate type resin, they have more excellent performance than inorganic matting agents and polyethylene wax, polymethyl urea, and other organic matting agents.

[0004] But the thermosetting PMMA or PST microspheres mentioned above can be used as matting agent, the appearance of these products is solid powder form, there is a great risk of dust explosion, especially in the relatively closed production workshop. Because these powders are very light, it is easy to be inhaled into the body, there is a great risk of occupational health. Because of the dry powder, it is difficult to disperse uniformly in the formulation system, in the industrial production, generally need to add a filter step after the paint is finished, or add a certain amount of wet dispersant to help its dispersion. In order to solve the dispersion problem of resin particles, CN103030731A and other hydrophilic modification of resin particles can obtain good dispersion of resin particles, but the person skilled in the art is familiar with the introduction of too much hydrophilic segment on the resin particles will significantly reduce the resistance of the coating, especially the water resistance. In addition, the use of these vinyl polymer microspheres, matting particle composition or dispersion, although the paint film transparency and resistance are better than the use of inorganic matting filler and organic matting agent such as polymethyl urea, but due to the difference between the refractive index and the film forming resin, the transparency cannot meet the high-end consumer's demand for high transparency, especially in the case of high addition amount. Considering the compatibility with other film forming resins, it will greatly limit its application range. The size of these particles is relatively large, generally in the range of 1-30um, and there is a certain density difference between the film forming resin. Considering the long-term storage and the use of container sea transportation, the person skilled in the art is familiar with the standard for judging the storage stability, which is generally no caking or hard precipitation after storing at 50℃ for at least four weeks. At present, it is difficult to store stably without stratification and precipitation for the water dispersion or water-based composition containing large particle size vinyl polymer particles with a certain density difference before the film forming resin, unless a certain amount of thickening agent or anti-settling agent is added to improve the viscosity of the system, such as CN102533040A, CN102952462A, CN105308131A. But in the coating system with high requirements for water and chemical resistance, the additional thickening agent and highly hydrophilic partially hydrolyzed ethyl acetate (co) polymer stabilizer are not conducive.

[0005] In view of the above status, in recent years, the research on self-matt resin which can make the coating or adhesive achieve lower gloss effect without adding organic and or inorganic extinction particles has gradually risen. At present, the water-based self-matt resin research is more mainly water-based polyurethane self-matt resin and water-based acrylate modified polyurethane self-matt resin, for example: CN103613702A etc. The research on water-based acrylate self-matt resin is not much, mainly because the principle of extinction is mainly to increase the unevenness of the coating surface, and enhance the scattering of light. Water-based polyurethane resin and water-based acrylate modified polyurethane resin, because of the dispersion process, can reduce the proportion of hydrophilic substances, and can generate several micron polyurethane or acrylate modified polyurethane particles in situ during the preparation of the resin. These particles can form a concave-convex surface after the resin is formed to achieve the effect of extinction. These particles are generated in situ, and the refractive index of the small particle size resin which forms the film is consistent, so the resin has excellent transparency after film formation. The density is also basically consistent, and they also have excellent storage stability. Because the water-based polyacrylate resin basically adopts the emulsion polymerization process, it is difficult to prepare a resin emulsion with a particle size greater than 1 um, and there are no large particles. These resins are difficult to self-matt. Therefore, at present, the water-based acrylate self-matt resin is mainly in the form of adding several micron extinction particles after adding. This external addition will cause various problems such as transparency, storage stability, etc. as described above

[0006] Chinese patent CN106608943A discloses a single-component acrylic matte core-shell emulsion with excellent water white performance, and its preparation method and application. The method adjusts the different PH values to make the core layer part neutralize with different degrees of 3-10 carbon atom oleic acid functional monomers, so that the emulsion has a surface micro-phase separation rough structure after film formation, and different matte degrees of emulsion are obtained. In the results described, the coating film prepared by the emulsion has obvious differences between crystal regions and amorphous regions under a 500-fold magnifying glass. Although the phase separation can effectively reduce the gloss of the coating film, the stability of the resin is also very good, but due to the difference in refractive index between the crystal region and the amorphous region, the transparency of the paint film formed is not high, and the transparency is a very important performance for varnish paint film, especially for topcoat. Chinese patent CN109180854A discloses a water-based self-extinguishing controllable gloss acrylic resin and its preparation method. The method controls the content of the organic high molecular flocculant by controlling the different proportions of carboxyl groups in acrylic acid and acrylic acid derivatives, thereby controlling the gloss of the coating film. With the increase of the acid content in the seed monomer, the number of the synthesized organic high molecular flocculant increases and the particle size becomes larger. At the same time, due to the loose structure of the flocculation effect, there is a difference between the refractive index of the air and the emulsion of the acrylic ester monomer itself in the paint film, so the gloss of the coating film will further decrease. However, due to the introduction of air, the transparency of the paint film will also become very poor. Chinese patent CN103467639A discloses a core-shell emulsion preparation method with controllable matte degree and its application. The method can obtain different matte emulsions by changing the amount of N-hydroxymethyl acrylamide in the outer shell vinyl monomer. Although the gloss is low, it is not clear whether the matte effect is caused by the emulsion itself or other factors due to the mixing of different film-forming emulsions and wax emulsions. SUMMARY

[0007] The purpose of the present application is to provide a water-based poly(meth)acrylate self-extinguishing resin, which can in-situ synthesize several micrometer poly(meth)acrylate particles during the preparation process, and also contains small particle size resin particles that provide film-forming effect. The paint film prepared thereby has excellent transparency and outstanding storage stability while achieving extinction effect. The present application solves the problems caused by adding extinction powder for traditional matte topcoat, reduces the harm to human body, and the multi-color paint film of the present application has excellent permeability, solving the problems of poor permeability and poor stability of paint film caused by other extinction methods.

[0008] To achieve the above purpose, the technical scheme of the present application is as follows:

[0009] A water-based poly(meth)acrylate self-extinguishing resin comprises the following raw materials:

[0010]

[0011] A method for preparing the water-based poly(meth)acrylate self-diminished resin according to the present application, comprising the following steps:

[0012] (1) Preparation of seed emulsion containing oligomer:

[0013] (1-1) Add 0.5-1.5 wt% of emulsifier based on the total weight of monomers and molecular weight regulators in monomer pre-emulsion a to water, then add 68-92 wt% of non-ionic monovinyl (meth)acrylate, 0.2-2 wt% of hydrophilic monovinyl monomer, and 6.5-30 wt% of molecular weight regulator based on the total weight of monomers and molecular weight regulators in monomer pre-emulsion a to the water containing emulsifier to prepare monomer pre-emulsion a;

[0014] (1-2) Add 92-98 wt% of non-ionic monovinyl (meth)acrylate, 2-8 wt% of hydrophilic monovinyl monomer, 1.25-6.75 wt% of emulsifier, and deionized water based on the total weight of polymers in poly(meth)acrylate seed emulsion to a reaction kettle, heat to 80-90°C, and add 0.1-0.2 wt% of water-soluble initiator based on the total weight of polymers in poly(meth)acrylate seed emulsion to initiate the reaction to obtain poly(meth)acrylate seed emulsion;

[0015] (1-3) Add the monomer pre-emulsion a obtained in (1-1) and water-soluble initiator dropwise into the poly(meth)acrylate seed emulsion obtained in (1-2) to continue emulsion polymerization to obtain seed emulsion containing oligomer;

[0016] (2) Preparation of water-based (meth)acrylate self-diminished resin:

[0017] (2-1) Mix 80-97 wt% of non-ionic monovinyl (meth)acrylate monomer and 3-20 wt% of hydrophilic monovinyl monomer based on the total weight of monomers used in monomer pre-emulsion b, then add oil-soluble azo initiator, and add the obtained mixture to an emulsifier aqueous solution to disperse it into monomer pre-emulsion b using a high-speed disperser;

[0018] (2-2) Add the seed emulsion containing oligomer of step (1) to the monomer pre-emulsion obtained in step (2-1) to swell;

[0019] (2-3) Add protective glue solution to the swollen seed emulsion obtained in (2-2) and initiate free radical polymerization by heating;

[0020] (2-4) Add water-soluble initiator to eliminate residual monomers at 65-75°C.

[0021] The particle size of the seed emulsion containing oligomers in step (1) is 200-800 nm, preferably 300-500 nm.

[0022] In step (2-1) of the present application, the monomer pre-emulsion is preferably prepared by a high-speed disperser at a speed of 500-10000 rpm, preferably 1000-5000 rpm, and more preferably 2000-3000 rpm.

[0023] In step (2-1) of the present application, the dispersion time of the monomer pre-emulsion is preferably controlled at 5-120 minutes, preferably 10-60 minutes, and more preferably 15-30 minutes.

[0024] In step (2-1) of the present application, since the high-speed disperser generates a large amount of heat during the preparation of the pre-emulsion, the temperature of the pre-emulsion will rise to a certain extent, so the dispersion needs to be carried out under the condition of controlling the temperature of the pre-emulsion, and the preferred temperature is 10-50℃, preferably 20-40℃, and more preferably room temperature.

[0025] In step (2-2) of the present application, the temperature during stirring and swelling should not be too high, so as to prevent a large amount of monomers from being absorbed by the seed emulsion containing oligomers and then free radical polymerization occurs, and the preferred temperature is 10-80℃, preferably 20-60℃, and more preferably 30-40℃.

[0026] In step (2-3) of the present application, the temperature for initiating free radical polymerization is 40-90℃, preferably 50-80℃; and the reaction time is 1-10 hours, preferably 4-6 hours.

[0027] The particle size of the water-based poly(meth)acrylate self-mattifying resin of the present application is 50-5000 nm, preferably 100-4000 nm. The poly(meth)acrylate particles in the range of 1000-5000 nm play a role in mattifying, and the poly(meth)acrylate emulsion in the range of 50-1000 nm can play a role in film formation. Preferably, the particle size is bimodal distribution, the large particle size part D50 particle size is preferably 2000-5000 nm, and the small particle size part particle size is preferably 50-150 nm. The volume percentage of the two parts is 1:1-10, preferably 1:1-4, and more preferably 1:1-1.5.

[0028] The Tg of the self-mattifying resin of the present application is in the range of -15℃-45℃, preferably in the range of 20-40℃.

[0029] The non-ionic monovinyl (meth)acrylate monomer of the present application is selected from (C 1-20) alkyl esters such as one or more of (meth)acrylic acid methyl ester, (meth)acrylic acid ethyl ester, (meth)acrylic acid butyl ester, (meth)acrylic acid 2-ethylhexyl ester, (meth)acrylic acid hydroxyethyl ester, (meth)acrylic acid hydroxypropyl ester, preferably one or more of methyl methacrylate, butyl acrylate, (meth)acrylic acid 2-ethylhexyl ester.

[0030] The hydrophilic monovinyl monomer according to the present application is selected from one or more of methacrylic acid, acrylic acid, propyleneoxypropionic acid, methyleneoxypropionic acid, itaconic acid, maleic acid or anhydride, fumaric acid, crotonic acid, maleic acid monomethyl ester, fumaric acid monomethyl ester, itaconic acid monomethyl ester, acrylamide, methacrylamide, N-hydroxymethyl acrylamide, N,N-dimethyl acrylamide, diacetone acrylamide, methacrylamidoethyl ethylene urea, preferably one or both of methacrylic acid and acrylic acid, more preferably acrylic acid.

[0031] The addition of the hydrophilic monovinyl monomer according to the present application greatly improves the film-forming property of the paint film and reduces the amount of film-forming aids used. The addition of the hydrophilic monovinyl monomer also functions as a transport agent, increasing the solubility of the non-ionic monovinyl (meth)acrylate monomer and the oil-soluble azo initiator in water. Under the action of the emulsifier, a large amount of monomer undergoes emulsion polymerization while free radical polymerization occurs, forming a film-forming emulsion with a small particle size, providing sufficient film-forming property for the entire resin. It also increases the rate of monomer migration into the seed emulsion. However, the amount of hydrophilic monovinyl monomer used should not be too large, as this would result in poor water resistance of the paint film.

[0032] The molecular weight regulator according to the present application is selected from one or more of tetrabromomethane, sodium methylallyl sulfonate, alkyl sulfide and mercaptan, preferably one or more of alkyl sulfide and C4-C22 linear or branched alkyl mercaptan, more preferably one or more of 3-mercapto propionic acid methyl ester, 3-mercapto propionic acid butyl ester, n-hexyl mercaptan, n-dodecyl mercaptan.

[0033] The purpose of using the molecular weight regulator is to prepare a seed emulsion containing oligomers, the proportion of the molecular weight regulator in the seed emulsion containing oligomers being 5-60 wt%, preferably 7-40 wt% of the weight of the polymer. The weight average molecular weight of the oligomers is 200-10000, preferably 1000-8000, more preferably 2000-5000. The particle size of the seed emulsion containing oligomers is selected from 200-800 nm, preferably 300-500 nm. Due to the presence of the oligomers, the seed emulsion more easily absorbs monomers, so that the volume can swell several times or even tens of times.

[0034] The emulsifier according to the present application is selected from anionic emulsifiers such as sodium dodecylbenzenesulfonate, sodium dodecylsulfate, sodium tridecylsulfate, sodium 2-ethylhexyl sulfate, sodium alkyl succinate sulfonate; or nonionic emulsifiers such as one or more of tridecyl alcohol ethoxylate, oleic acid alcohol ethoxylate, octylphenol ethoxylate, nonylphenol ethoxylate; or anionic-nonionic emulsifiers such as one or more of alkyl polyoxyethylene ether sulfate, alkyl polyoxyethylene ether; preferably anionic emulsifiers, more preferably one or more of sodium dodecylbenzenesulfonate, sodium dodecylsulfate, sodium tridecylsulfate.

[0035] The azo oil-soluble initiator according to the present application is selected from azobis(isobutyronitrile), azobis(isoheptyl nitrile), preferably azobis(isobutyronitrile).

[0036] Azobis(isobutyronitrile) has a certain polarity and can be partially dissolved in water in the presence of a certain amount of polar monomers, especially acrylic ester monomers containing carboxylic acid. Thus, when seed swelling suspension polymerization is carried out, the part of azobis(isobutyronitrile) that swells into the seed along with the monomers can initiate suspension polymerization when the temperature is raised, generating several microns of poly(meth)acrylate particles that play an extinction role. The part of azobis(isobutyronitrile) that is dissolved in water can initiate emulsion polymerization in the presence of an emulsifier, generating tens to hundreds of nanometers of polyacrylate emulsion that plays a film-forming role.

[0037] The water-soluble initiator according to the present application is selected from any one of potassium persulfate, sodium persulfate and ammonium persulfate or a combination thereof with ascorbic acid, a combination of tert-butyl hydroperoxide with ascorbic acid. Since the decomposition temperature of azobis(isobutyronitrile) is relatively low, its half-life t1 / 2=0.1h (101℃), 1.0h (82℃), 10h (65℃), and due to the heat released by the reaction in the later stage of the reaction, the temperature will surge to about 100℃, and with the increase of the temperature, azobis(isobutyronitrile) will be quickly consumed, at this time, there will be a part of the monomers that are not completely reacted, and finally the water-soluble initiator can be used for post-treatment to eliminate residual monomers, and due to the presence of a large amount of emulsifier, the part of the monomers will all undergo emulsion polymerization to generate tens to hundreds of nanometers of poly(meth)acrylate emulsion that further helps the resin to form a film. Preferably, the redox reaction of tert-butyl hydroperoxide with ascorbic acid is used for post-treatment, and the post-treatment temperature is preferably 65-75℃.

[0038] The protective colloid according to the present application is selected from one or more of polyvinyl alcohol with a molecular weight of 40000-200000, chitosan, polyacrylic acid sodium salt, polyvinylpyrrolidone, preferably polyvinyl alcohol.

[0039] When the in-situ generated poly(meth)acrylate particle size is less than 1.5um, no protective colloid is needed, and the non-ionic emulsifier containing 20-40 EO can provide sufficient stability. However, when the in-situ generated poly(meth)acrylate particle size is greater than 1.5um, especially when the Tg of the poly(meth)acrylate particles is in the range of 40-60℃, it is preferred to use polyvinyl alcohol as a protective colloid to provide stability to the resin.

[0040] In the scheme described in the present application, by taking advantage of the water solubility of azo oil initiator and (meth)acrylate monomers, and by controlling the amount of initiator and emulsifier added, simultaneous suspension polymerization and emulsion polymerization can occur during the process of free radical polymerization. Two particle sizes of poly(meth)acrylate particles can be produced, and suspension polymerization can synthesize poly(meth)acrylate particles of several microns in situ. Due to the presence of seeds, the swelling ratio is controlled, effectively controlling the particle size of large-sized poly(meth)acrylate particles, and the distribution is relatively narrow, and the extinction effect is better than that of particles with wide distribution. The emulsion polymerization generates small particle size emulsion that provides film forming effect. Since the refractive index of the in-situ generated micron-sized particles and the small particle size emulsion is consistent, the prepared paint film has very excellent transparency while achieving extinction effect. Since the density of the in-situ generated micron-sized particles and the small particle size emulsion is basically consistent, further prevention of large particle sedimentation can be achieved, and the resin has excellent storage stability.

[0041] The present application provides a mask-free self-extinguishing multi-color solution, which comprises the following parts:

[0042] A mask-free self-extinguishing multi-color paint, comprising the following components: 30-50wt% of a dispersed phase, 20-40wt% of a protective colloid solution, and 25-50wt% of a continuous phase.

[0043] The dispersed phase is prepared from the following raw materials: 40-60wt% of water, 0.8-2.5wt% of cellulose, 0.05-0.25wt% of a pH adjuster, 0.1-0.3wt% of a defoaming agent, 0.1-0.5wt% of a dispersing agent, 5-10wt% of a pigment and filler, 25-40wt% of resin A, 0.5-5wt% of a film-forming aid, 0.1-0.3wt% of a bactericide, 0.3-0.8wt% of an anti-freezing agent, 0.1-0.4wt% of a mildew-proof agent, and 4-8wt% of a protective colloid solution.

[0044] Further, the cellulose is preferably one or a mixture of hydroxyethyl cellulose and hydrophobically modified hydroxyethyl cellulose.

[0045] Further, the resin A of the dispersed phase is produced by Wanhua Chemical Co., Ltd.

[0046] The protective glue solution is prepared from the following raw materials: 5-15wt% of lithium magnesium silicate, 85-95wt% of water.

[0047] The continuous phase is prepared from the following raw materials: 5-30wt% of water, 60-85wt% of the matt resin B, 0.1-0.3wt% of pH regulator, 0.1-0.3wt% of defoaming agent, 1-10wt% of film forming aid, 1-10wt% of anti-freezing agent, 0.1-0.3wt% of bactericide, 0.4-0.8wt% of thickening agent.

[0048] Further, the continuous phase matt resin B is the water-based poly(meth)acrylate matt resin prepared in the present application.

[0049] The poly(meth)acrylate matt resin in the present application is used in coatings or adhesives, and the coating or finish has high transparency, smooth touch, and storage stable matt performance. Preferably, the above-mentioned acrylate matt resin is used in coatings or adhesives for buildings, wood, synthetic leather coated products, paper, and plastics, as matt coating or matt finish, and more preferably, as water-based multi-color coating for buildings.

[0050] The purpose of the present application is to prepare a water-based (meth)acrylate matt resin consistent with the matt principle of water-based polyurethane and water-based acrylate modified polyurethane, and its application, using the way of seed swelling suspension polymerization, using azo oil initiator and water solubility of (meth)acrylate monomer, by controlling the amount of initiator and emulsifier, the process of free radical polymerization can occur simultaneously with suspension polymerization and emulsion polymerization. Two kinds of poly(meth)acrylate particles can be produced, suspension polymerization can synthesize several microns of poly(meth)acrylate particles in situ, because of the existence of seeds, control the swelling ratio, effectively control the particle size of large particle size poly(meth)acrylate particles, and the distribution is narrow, and the matt effect is better than the wide distribution of particles. The emulsion polymerization generates small particle size emulsion which provides film forming effect, because the refractive index of the micron level particles and the small particle size emulsion generated in situ is consistent, the paint film prepared by the resin has very excellent transparency while achieving matt effect. Because the density of the micron level particles and the small particle size emulsion generated in situ is basically consistent, the settlement of large particles can be further prevented, and the resin has excellent storage stability. The water-based multi-color coating prepared by the resin provides a matt multi-color coating and a preparation method thereof, reduces the construction steps, and can greatly improve the efficiency and save the cost; the present application solves the problems caused by adding matt powder for matt finish in traditional matt finish, and reduces the harm to human body; the matt multi-color coating film of the present application has excellent permeability, and solves the problems of poor permeability and poor stability of the paint film caused by other matt methods.

[0051] Term explanation:

[0052] "Copolymer" means a polymer polymerized from at least two different monomers.

[0053] "Oligomer" means a polymer consisting of multiple repeating units, the number of which is controllable, and the weight average molecular weight of which is in the range of 200-10000. The oligomer in the present application, which is copolymerized with the vinyl-containing polymerizable monomer, is a polymer with a weight average molecular weight in the range of 200-10000, which is obtained by polymerization of the polymerizable vinyl monomer in the presence of a molecular chain regulator. The content of the oligomer is tested as follows: the seed containing the oligomer is dissolved in tetrahydrofuran solvent, and the weight average molecular weight of the seed is tested by gel permeation chromatography (model e2695-2414RID, Waters Corporation), and the proportion of the weight average molecular weight in the range of 200-10000 is counted.

[0054] "Average particle size" is the value of d50 measured on a German new Patek wet laser particle size analyzer HELOS / SUCELL (from German new Patek Co., Ltd.). "Molecular weight" or "Mw" refers to the weight average molecular weight of the polymer determined by gel permeation chromatography (GPC) relative to polyacrylic acid standard. "Swelling" refers to a process in which the vinyl-containing polymerizable monomer continuously penetrates into the seed emulsion containing the oligomer, so that the particle size of the seed emulsion continuously increases.

[0055] "wt%" refers to weight percent. "60° gloss" refers to the gloss of the coating determined by using MN268 type gloss meter (from Tianjin Qilisi Technology Co., Ltd.) at an observation angle of 60°.

[0056] "Glass transition temperature" refers to the glass transition temperature determined by differential scanning calorimetry (DSC), and the inflection point on the differential analysis diagram is taken as the glass transition temperature value.

[0057] "High-speed disperser" is a JFS-2200 / T multifunctional experimental machine from Shanghai Saje Chemical Equipment Co., Ltd.

[0058] Unless otherwise specified, all temperature and pressure units are standard temperature and pressure (STP). Optionally added means added or not added. DETAILED DESCRIPTION

[0059] The present application will be further described in conjunction with specific examples. However, the examples are not a limitation of the present application. Unless otherwise specified, parts and % are by weight.

[0060] Example 1

[0061] (1-1) 6 grams of ethoxylated sodium alkyl sulfate salt (Solvay Rhodapex CM-30), 220 grams of deionized water were added to a pre-emulsification kettle, after stirring and dissolving, 96 grams of methyl methacrylate, 411 grams of butyl acrylate, 3 grams of acrylic acid, and 45 grams of n-dodecanethiol were added to form a stable monomer pre-emulsified liquid;

[0062] (1-2) 0.75 grams of sodium dodecyl sulfate, 19 grams of butyl acrylate, 1 gram of acrylic acid, and 980 grams of deionized water were added to the reaction kettle, stirring and heating were started, and the temperature was raised to 85°C. A solution of 0.03 grams of ammonium persulfate and 1 gram of deionized water was added, and after the blue light appeared, the reaction was continued for 15 minutes to prepare a seed emulsion;

[0063] (1-3) The prepared monomer pre-emulsified liquid and a solution of 1.2 grams of ammonium persulfate and 12 grams of deionized water were added dropwise to the seed emulsion, and the dropping was carried out for 4 hours. After the dropping was completed, the temperature was kept for 1 hour, and then the temperature was lowered to 45°C. Filtration was performed to obtain a seed emulsion containing oligomers with an average particle size of about 0.65 um.

[0064] Example 2

[0065] (1-1) 6 grams of ethoxylated sodium alkyl sulfate salt (Solvay Rhodapex CM-30), 220 grams of deionized water were added to a pre-emulsification kettle, after stirring and dissolving, 96 grams of methyl methacrylate, 411 grams of butyl acrylate, 3 grams of acrylic acid, and 45 grams of n-dodecanethiol were added to form a stable monomer pre-emulsified liquid;

[0066] (1-2) 0.75 grams of sodium dodecyl sulfate, 19 grams of butyl acrylate, 1 gram of acrylic acid, and 980 grams of deionized water were added to the reaction kettle, stirring and heating were started, and the temperature was raised to 85°C. A solution of 0.03 grams of ammonium persulfate and 1 gram of deionized water was added, and after the blue light appeared, the reaction was continued for 15 minutes to prepare a seed emulsion;

[0067] (1-3) The prepared monomer pre-emulsified liquid and a solution of 1.2 grams of ammonium persulfate and 12 grams of deionized water were added dropwise to the seed emulsion, and the dropping was carried out for 4 hours. After the dropping was completed, the temperature was kept for 1 hour, and then the temperature was lowered to 45°C. Filtration was performed to obtain a seed emulsion containing oligomers with an average particle size of about 0.65 um.

[0068] Example 3

[0069] (1-1) 6 grams of ethoxylated sodium alkyl sulfate salt (Solvay Rhodapex CM-30), 220 grams of deionized water were added to a pre-emulsification kettle, after stirring and dissolving, 96 grams of methyl methacrylate, 411 grams of butyl acrylate, 3 grams of acrylic acid, and 45 grams of n-dodecanethiol were added to form a stable monomer pre-emulsified liquid;

[0070] (1-2) Into a reactor, 0.25 g of sodium dodecyl sulfate, 19 g of methyl methacrylate, 1 g of acrylic acid and 980 g of deionized water were added, stirring and heating were started, and the temperature was raised to 85°C. A solution of 0.03 g of ammonium sulfate and 1 g of deionized water was added, and after the blue light appeared, the reaction was continued for 15 minutes to prepare a seed emulsion;

[0071] (1-3) The prepared monomer pre-emulsion and a solution of 1.2 g of ammonium sulfate and 12 g of deionized water were added dropwise to the seed emulsion, and the dropping was continued for 4 hours. After the dropping was completed, the temperature was kept for 1 hour, and then the temperature was lowered to 45°C. Filtration was performed to obtain a seed emulsion containing oligomers with an average particle size of about 0.78 um.

[0072] Comparative Example 1

[0073] (1-1) Into a pre-emulsification kettle, 6 g of ethoxylated alkyl sulfate sodium salt (Solvay Rhodapex CM-30) and 220 g of deionized water were added, and after stirring and dissolving, 146 g of methyl methacrylate, 451 g of butyl acrylate and 3 g of acrylic acid were added to form a stable monomer pre-emulsion;

[0074] (1-2) Into a reactor, 0.25 g of sodium dodecyl sulfate, 19 g of methyl methacrylate, 1 g of acrylic acid and 980 g of deionized water were added, stirring and heating were started, and the temperature was raised to 85°C. A solution of 0.03 g of ammonium sulfate and 1 g of deionized water was added, and after the blue light appeared, the reaction was continued for 15 minutes to prepare a seed emulsion;

[0075] (1-3) The prepared monomer pre-emulsion and a solution of 1.2 g of ammonium sulfate and 12 g of deionized water were added dropwise to the seed emulsion, and the dropping was continued for 4 hours. After the dropping was completed, the temperature was kept for 1 hour, and then the temperature was lowered to 45°C. Filtration was performed to obtain a seed emulsion containing oligomers with an average particle size of about 0.78 um.

[0076] Example 4

[0077] (2-1) Into a monomer charging kettle, 10 parts by weight of methyl methacrylate, 9 parts by weight of butyl acrylate, 0.5 parts by weight of methacrylamide ethyl ethylene urea, 1 part by weight of methacrylic acid and 0.2 parts by weight of azobisisobutyronitrile were added. The azobisisobutyronitrile was completely dissolved in the above-mentioned monomers by ultrasonic treatment. Subsequently, the monomer mixture was poured into a dispersion kettle containing 2 parts by weight of sodium dodecylbenzenesulfonate and 60 parts by weight of water, and the temperature was controlled at about 30°C. The dispersion was performed by a high-speed disperser at a speed of 1000 rpm for 15 minutes;

[0078] (2-2) Pour the product of step (2-1) into a polymerization kettle equipped with 0.5 parts by weight of the seed emulsion containing oligomer of Example 2, a stirrer, and a condenser, and protect with nitrogen, and allow the emulsion to swell for 1 hour at 25°C with a stirring speed of 180 rpm;

[0079] (2-3) Add an aqueous PVA solution (0.1 parts of PVA dissolved in 10 parts of deionized water at 85°C) to the polymerization kettle, and raise the temperature to 80°C to initiate polymerization, and polymerize for 2 hours at this temperature;

[0080] (2-4) Add 0.25 parts of the post-treatment initiator t-butyl hydroperoxide / ascorbic acid at 70°C, and maintain for 1 hour, and then lower to room temperature, and filter the emulsion using a 350 mesh filter to obtain a bi-modal self-sterilizing poly(meth)acrylate emulsion, and test the large particle size portion using a particle size instrument, D50 = 3.8 um, and the small particle size portion is about 100 nm. The volume percentage of the large particle size portion is about equal to 42.3%.

[0081] Comparative Example 2

[0082] (2-1) Add 10 parts by weight of methyl methacrylate, 9 parts by weight of butyl acrylate, 0.5 parts by weight of methacrylamide ethyl ethylene urea, 1 part by weight of methacrylic acid, and 0.2 parts by weight of azobisisobutyronitrile to a monomer charging kettle, and use ultrasonic waves to completely dissolve the azobisisobutyronitrile in the above monomers, and then pour the monomer mixture into a dispersing kettle containing 2 parts by weight of sodium dodecylbenzenesulfonate and 60 parts by weight of water, and control the temperature at about 30°C, and disperse using a high speed disperser at a speed of 1000 rpm for 15 minutes;

[0083] (2-2) Pour the product of step (2-1) into a polymerization kettle equipped with 0.5 parts by weight of the seed emulsion containing oligomer of Example 2, a stirrer, and a condenser, and protect with nitrogen, and allow the emulsion to swell for 1 hour at 25°C with a stirring speed of 180 rpm;

[0084] (2-3) Add an aqueous PVA solution (0.1 parts of PVA dissolved in 10 parts of deionized water at 85°C) to the polymerization kettle, and raise the temperature to 80°C to initiate polymerization, and polymerize for 2 hours at this temperature;

[0085] (2-4) Add 0.25 parts of the post-treatment initiator t-butyl hydroperoxide / ascorbic acid at 70°C, and maintain for 1 hour, and then lower to room temperature, and filter the emulsion using a 350 mesh filter, and 350 mesh filtration is difficult, and the large particle size is in the range of tens to hundreds of microns, and the small particle size is about 100 nm.

[0086] Comparative Example 3

[0087] (2-1) To a monomer charging tank, 75 parts by weight of butyl methacrylate, 1 part by weight of methacrylamidoethyl ethylene urea, 2 parts by weight of methacrylic acid, 1.25 parts by weight of azobisisheptyl nitrile were added, and the azobisisheptyl nitrile was completely dissolved in the above monomers using ultrasonic waves. Subsequently, the monomer mixture was poured into a dispersing tank containing 2.5 parts by weight of sodium dodecyl sulfate and 95 parts by weight of water, and dispersed at 1500 rpm using a high-speed disperser for 20 minutes;

[0088] (2-2) A PVA aqueous solution (2 parts of PVA dissolved in 100 parts of deionized water at 85°C) was added to the polymerization tank, and the temperature was raised to 80°C to initiate polymerization, and the polymerization was carried out at this temperature for 2 hours;

[0089] (2-3) 0.75 parts by weight of a post-treatment initiator, t-butyl hydroperoxide / ascorbic acid, was added at 70°C, and the mixture was kept at this temperature for 1 hour, and then cooled to room temperature. The emulsion was filtered using a 350-mesh filter, and a bimodal self- extinguishing poly(meth)acrylate emulsion was obtained. The particle size analyzer was used to test the large particle size portion D50 = 3.6 um, and the small particle size portion was about 103 nm. The volume percentage of the large particle size portion was about equal to 43.1%.

[0090] Example 5

[0091] (2-1) To a monomer charging tank, 75 parts by weight of butyl methacrylate, 1 part by weight of methacrylamidoethyl ethylene urea, 2 parts by weight of methacrylic acid, 1.25 parts by weight of azobisisheptyl nitrile were added, and the azobisisheptyl nitrile was completely dissolved in the above monomers using ultrasonic waves. Subsequently, the monomer mixture was poured into a dispersing tank containing 2.5 parts by weight of sodium dodecyl sulfate and 95 parts by weight of water, and dispersed at 1500 rpm using a high-speed disperser for 20 minutes;

[0092] (2-2) The product of step (2-1) was poured into a polymerization tank equipped with 1.3 parts by weight of the seed emulsion containing oligomers of Example 1, a stirrer, and a condenser, and protected with nitrogen. The emulsion was allowed to swell at 25°C and a stirring speed of 180 rpm for 5 hours;

[0093] (2-3) A PVA aqueous solution (2 parts of PVA dissolved in 100 parts of deionized water at 85°C) was added to the polymerization tank, and the temperature was raised to 80°C to initiate polymerization, and the polymerization was carried out at this temperature for 2 hours;

[0094] (2-4) 0.75 parts by weight of a post-treatment initiator, t-butyl hydroperoxide / ascorbic acid, was added at 70°C, and the mixture was kept at this temperature for 1 hour, and then cooled to room temperature. The emulsion was filtered using a 350-mesh filter, and a bimodal self- extinguishing poly(meth)acrylate emulsion was obtained. The particle size analyzer was used to test the large particle size portion D50 = 3.6 um, and the small particle size portion was about 103 nm. The volume percentage of the large particle size portion was about equal to 43.1%.

[0095] Example 6

[0096] (2-1) To a monomer charge tank was added 65 parts by weight of butyl methacrylate, 2 parts by weight of methacrylamidoethyl ethylene urea, 2 parts by weight of methacrylic acid, 1.25 parts by weight of azobisisoheptanenitrile, and the azo initiator was completely dissolved in the monomers using ultrasonics. The monomer mixture was then poured into a dispersion tank containing 4 parts by weight of sodium dodecyl sulfate, 95 parts by weight of water, and dispersed using a high speed disperser at 1500 rpm for 20 minutes;

[0097] (2-2) The product of step (2-1) was poured into a polymerization tank equipped with 1.3 parts by weight of the seed emulsion containing oligomers of Example 3, a stirrer, and a condenser and protected with nitrogen. The emulsion was allowed to swell at 25 °C for 5 hours with stirring at 180 rpm;

[0098] (2-3) An aqueous PVA solution (1.4 parts of PVA dissolved in 100 parts of deionized water at 85 °C) was added to the polymerization tank, and the temperature was raised to 80 °C to initiate polymerization. The polymerization was carried out at this temperature for 2 hours.

[0099] (2-4) At 70 °C, 0.75 parts by weight of a post-treatment initiator, t-butyl hydroperoxide / ascorbic acid, was added, and the temperature was maintained for 1 hour. The temperature was then lowered to room temperature, and the emulsion was filtered using a 350 mesh screen to obtain a bi-modal self- extinguishing poly(meth)acrylate emulsion. The D50 of the large particle size fraction was 3.1 um, and the small particle size fraction was about 80 nm. The volume percentage of the large particle size fraction was about 43.9%.

[0100] Comparative Example 4

[0101] A resin particle suspension was prepared according to the method described in Example 4 of patent CN103030731A.

[0102] Comparative Example 5

[0103] (2-1) To a monomer charge tank was added 65 parts by weight of butyl methacrylate, 2 parts by weight of methacrylamidoethyl ethylene urea, 2 parts by weight of methacrylic acid, 1.25 parts by weight of azobisisoheptanenitrile, and the azo initiator was completely dissolved in the monomers using ultrasonics. The monomer mixture was then poured into a dispersion tank containing 4 parts by weight of sodium dodecyl sulfate, 95 parts by weight of water, and dispersed using a high speed disperser at 1500 rpm for 20 minutes;

[0104] (2-2) Pour the product of step (2-1) into a polymerization kettle equipped with 0.5 parts by weight of the seed emulsion containing oligomer of Example 2, a stirrer and a condenser and protected with nitrogen, and allow the emulsion to swell at 25°C for 1 hour at a stirring speed of 180 rpm;

[0105] (2-3) Add an aqueous PVA solution (0.1 parts of PVA dissolved in 10 parts of deionized water at 85°C) to the polymerization kettle, and raise the temperature to 80°C to initiate polymerization, and polymerize at this temperature for 2 hours;

[0106] (2-4) At 70°C, add 0.25 parts of post-treatment initiator t-butyl hydroperoxide / ascorbic acid, and maintain the temperature for 1 hour, and then lower the temperature to room temperature, and filter the emulsion using a 350-mesh filter to obtain a self- extinguishing crosslinked poly(meth)acrylate emulsion having a bimodal distribution, and test the large-particle-size portion using a particle size instrument, D50 = 3.8 um, and the small-particle-size portion is about 100 nm. The volume percentage of the large-particle-size portion is about equal to 42.3%.

[0107] Self-extinguishing resin performance evaluation: The water-based multicolor paint comprises a dispersed phase, a protective colloid solution and a continuous phase, and the mass ratio among them is 45:25:30.

[0108] The components and mass parts of the dispersed phase are as follows:

[0109] Deionized water 42.8 parts, cellulose (250HBR) 0.4 parts, cellulose (EHM500) 0.6 parts, pH regulator (AMP-95) 0.1 parts, defoamer (SN-154) 0.4 parts, dispersant (731A) 0.3 parts, titanium dioxide (R996) 0.5 parts, kaolin (DB-80) 9.5 parts, resin A (8028) 30 parts, film-forming aid (Texanol) 1.5 parts, mildewcide (DF-19) 0.2 parts, bactericide (LX150) 0.1 parts, anti-freezing agent (propylene glycol) 0.6 parts, protective colloid solution (S482) 8 parts, deionized water 5 parts;

[0110] The dispersed phase is prepared according to the following steps: add deionized water, cellulose according to the formula, stir at 300 rpm for 5 minutes, add pH regulator, defoamer, dispersant in sequence, mix and stir until uniform, then slowly add titanium dioxide and kaolin, disperse at 1500 rpm until fineness ≤50 um, add resin A, film-forming aid, mildewcide, bactericide, anti-freezing agent, protective colloid solution and the remaining deionized water, and stir until uniform for standby use.

[0111] The components and mass parts of the continuous phase are as follows:

[0112] ​Deionized water 12 parts, self-extinction resin B described in the examples and comparative examples, film forming aid (Texanol) 4 parts, anti-freeze agent (propylene glycol) 2 parts, defoaming agent (NXZ) 0.4 parts, bactericide (LX150) 0.2 parts, mildewcide (DF-19) 0.2 parts, alkali swelling thickener (A401) 0.2 parts, polyurethane thickener 0.2 parts.

[0113] The continuous phase is prepared according to the following steps: according to the formulation amount, the above deionized water, emulsion B, film forming aid, anti-freeze agent, defoaming agent, bactericide, mildewcide, alkali swelling thickener, polyurethane thickener are mixed and stirred at 1000 rpm until uniform for standby.

[0114] Mix 45 parts of the dispersed phase and 25 parts of the protective glue solution, add the mixture to the granulation equipment, and get the mixture of the dispersed phase color point suspended in the protective glue solution for standby.

[0115] Add 30 parts of the continuous phase to the granulation mixture and stir uniformly at 200 rpm to complete the preparation of the mask-free self-extinction multi-color coating.

[0116] The performance of the multi-color composite coating is in accordance with the technical standard of HG / T4343-2012 water-based multi-color architectural coating for external use, and the results are shown in Table 1.

[0117] Table 1 Performance of multi-color composite coating

[0118]

[0119] Those skilled in the art can understand that, under the teaching of the present specification, some modifications or adjustments can be made to the present application. These modifications or adjustments should also be within the scope defined by the claims of the present application.

Claims

1. An aqueous poly(meth)acrylic acid self-mattifying resin, characterized in that, Preparation is carried out by the following steps: (1) Preparation of seed emulsion containing oligomer: (1-1) 0.5-1.5wt% of emulsifier based on the total weight of monomers and molecular weight regulator in monomer pre-emulsion a is added to water, then 68-92wt% of non-ionic monovinyl (meth) acrylate, 0.2-2wt% of hydrophilic monovinyl monomer, 6.5-30wt% of molecular weight regulator based on the total weight of monomers and molecular weight regulator in monomer pre-emulsion a is added to the above water containing emulsifier to prepare monomer pre-emulsion a; (1-2) 92-98wt% of non-ionic monovinyl (meth) acrylate, 2-8wt% of hydrophilic monovinyl monomer, 1.25-6.75wt% of emulsifier, deionized water based on the total weight of polymer in poly (meth) acrylate seed emulsion is added to the reaction kettle, heated to 80-90℃, 0.1-0.2wt% of water-soluble initiator based on the total weight of polymer in poly (meth) acrylate seed emulsion is added at one time to initiate the reaction to prepare poly (meth) acrylate seed emulsion; (1-3) The monomer pre-emulsion a obtained in (1-1) is added dropwise into the poly (meth) acrylate seed emulsion obtained in (1-2), and the emulsion polymerization is continued to obtain the seed emulsion containing oligomer; (2) Preparation of water-based (meth) acrylate self-extinction resin: (2-1) 80-97wt% of non-ionic monovinyl (meth) acrylate monomer, 3-20wt% of hydrophilic monovinyl monomer based on the total weight of monomers used in monomer pre-emulsion b is mixed uniformly, then an azo oil-soluble initiator is added, and the obtained mixture is added to an emulsifier aqueous solution, which is dispersed into monomer pre-emulsion b by using a high-speed disperser; (2-2) The seed emulsion containing oligomer of step (1) is added to the monomer pre-emulsion obtained in step (2-1) for swelling; (2-3) The protective glue solution is added to the swollen seed emulsion obtained in (2-2), and the temperature is raised to initiate free radical polymerization; (2-4) Water-soluble initiator is added at 65-75℃ to eliminate residual monomer; the protective glue is selected from one or more of polyvinyl alcohol with a molecular weight of 40000-200000, chitosan, polyacrylic acid sodium salt, and polyvinylpyrrolidone; The particle size of the water-based poly (meth) acrylate self-extinction resin is bimodal distribution, the large particle size part D50 particle size is 2000-5000nm, and the small particle size part particle size is 50-150nm; the volume percentage of the large particle size part and the small particle size part is 1:1-10.

2. The self-darkening resin according to claim 1, wherein, It comprises the following raw materials:

3. The self-darkening resin of claim 1, wherein, In the step (1), the particle size of the seed emulsion containing oligomer is 200nm-800nm.

4. The self-darkening resin of claim 1, wherein, The particle size of the water-based poly (meth) acrylate self-extinction resin is 50-5000nm.

5. The self-darkening resin of claim 1, wherein, The volume percentage of the large particle size part and the small particle size part is 1:1-4.

6. The self-darkening resin of claim 1, wherein, The Tg of the self-extinction resin is-15℃-45℃.

7. The self-darkening resin of claim 1, wherein, It comprises the following raw materials:

8. The self-darkening resin of claim 1, wherein, The particle size of the seed emulsion containing oligomer in step (1) is 300-500 nm.

9. The self-darkening resin of claim 1, wherein, The aqueous poly(meth)acrylate self-dimming resin has a particle size of 100-4000 nm.

10. The self-darkening resin of claim 1, wherein, The volume percentage of the large particle size part to the small particle size part is 1:1-1.

5.

11. The self-darkening resin of claim 1, wherein, The Tg of the self-dimming resin is 20-40℃.

12. A mask-free self-dimming multi-color paint, comprising the following components: 30-50wt% of a dispersed phase, 20-40wt% of a protective peptizing solution, and 25-50wt% of a continuous phase. The dispersed phase is prepared from the following raw materials: water 40-60 wt%, cellulose 0.8-2.5 wt%, pH regulator 0.05-0.25 wt%, antifoaming agent 0.1-0.3 wt%, dispersant 0.1-0.5 wt%, pigment and filler 5-10 wt%, 802825 - 40 wt%, film forming aid 0.5-5 wt%, bactericide 0.1-0.3 wt%, anti-freezing agent 0.3-0.8 wt%, mildew-proof agent 0.1-0.4 wt%, protective colloid solution 4-8 wt%; The continuous phase is prepared from the following raw materials: 5-30wt% of water, 60-85wt% of the self-dimming resin according to any one of claims 1-11, 0.1-0.3wt% of a pH adjuster, 0.1-0.3wt% of an antifoaming agent, 1-10wt% of a film-forming aid, 1-10wt% of an anti-freezing agent, 0.1-0.3wt% of a bactericide, and 0.4-0.8wt% of a thickening agent.

13. The self-flattening self-extinguishing multicolor coating according to claim 12, characterized in that, The protective peptizing solution is prepared from the following raw materials: 5-15wt% of magnesium lithium silicate, and 85-95wt% of water.

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