Colorful continuous phase emulsion and preparation method thereof, colorful paint and preparation method and application thereof

Abstract

The invention provides a colorful continuous phase emulsion and a preparation method thereof, a colorful coating and a preparation method and application thereof, and relates to the technical field of emulsions.The preparation method of the colorful continuous phase emulsion comprises the following steps that (a) a hydrophobic monomer and a silane coupling agent are introduced into a polyurethane shell layer to be subjected to a cross-linking reaction with polyurethane, and a polyurethane prepolymer is obtained; and (b) reacting the polyurethane prepolymer obtained in the step (a) through an interfacial polymerization process to obtain the colorful continuous phase emulsion. According to the colorful continuous phase emulsion, a chain extender is added for reaction in the coating preparation process, and the chain extender and a polyurethane shell layer are subjected to reaction crosslinking. The invention solves the technical problems of poor water-white resistance, poor construction effect and paint film defects of the multicolor paint in the prior art, and achieves the technical effects of effectively improving the water-white resistance stability of the multicolor paint on the basis of strong stereoscopic impression and good appearance texture, and effectively improving the color and gloss of the paint at the same time.

Description

Technical Field

[0001] The invention relates to the technical field of emulsions, and in particular to a colorful continuous phase emulsion and a preparation method thereof, a colorful coating and a preparation method and application thereof. Background Art

[0002] In recent years, colorful paints with low cost, simple construction, and elegance and solemnity similar to marble and granite have become increasingly popular. As the market continues to expand, the competition for colorful paints is becoming increasingly fierce. The first problem facing manufacturers is the water whitening resistance of paints, and the main factor that determines the water whitening resistance of colorful paints is the colorful continuous phase emulsion.

[0003] At present, there are two main types of emulsions on the market, one is styrene-acrylate copolymer and the other is all-acrylate copolymer, each of which has its own characteristics. Although all-acrylate copolymers have good water-whitening stability, they have the problems of poor three-dimensional sense and poor appearance texture, which leads to poor market acceptance; styrene-acrylate copolymers are more likely to turn white during soaking due to the presence of styrene, which results in poor water-whitening resistance of colorful coatings, poor construction effect, and some defects in the paint film.

[0004] The main characteristics of styrene acrylic emulsion are strong three-dimensional sense and good appearance texture. Therefore, in order to make good use of styrene acrylic emulsion in colorful coatings, the problem of poor water whitening resistance of styrene acrylic emulsion must be solved.

[0005] In view of this, the present invention is proposed. Summary of the invention

[0006] One of the purposes of the present invention is to provide a method for preparing a colorful continuous phase emulsion, which can significantly improve the hydrophobicity and density of the polyurethane shell layer, thereby effectively solving the problem of the colorful continuous phase turning white when soaked in water.

[0007] The second object of the present invention is to provide a colorful continuous phase emulsion with good water whitening resistance and stability.

[0008] The third object of the present invention is to provide a multi-colored coating with good water whitening resistance, good color and gloss.

[0009] The fourth object of the present invention is to provide a method for preparing a colorful coating, by which a dense insulating layer is formed by cross-linking the chain extender with the polyurethane shell layer, thereby increasing the coverage rate of the polyurethane shell layer and further improving the water whitening resistance of the colorful coating.

[0010] A fifth object of the present invention is to provide an application of a multi-colored coating that can achieve outstanding application effects.

[0011] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly adopted:

[0012] In a first aspect, a method for preparing a colorful continuous phase emulsion comprises the following steps:

[0013] (a) introducing a hydrophobic monomer and a silane coupling agent into the polyurethane shell layer to undergo a cross-linking reaction with the polyurethane to obtain a polyurethane prepolymer;

[0014] (b) reacting the polyurethane prepolymer obtained in step (a) through an interfacial polymerization process to obtain the colorful continuous phase emulsion.

[0015] Further, the hydrophobic monomer includes at least one of dodecyl methacrylate and tridecyl methacrylate;

[0016] Preferably, the silane coupling agent includes at least one of vinyltriethoxysilane, γ(methacryloyloxy)propyltrimethoxysilane and vinyltrimethoxysilane.

[0017] Furthermore, in step (a), the raw materials for preparing the polyurethane prepolymer include the following components in parts by mass:

[0018] 2-4 parts of small molecule diol, 6-12 parts of macromolecular polyol, 3-6 parts of first functional monomer, 3-5 parts of hydrophilic polyol, 55-80 parts of polyisocyanate, 3-5 parts of organic amine, 1-5 parts of silane coupling agent, and 2-8 parts of hydrophobic monomer.

[0019] Further, the small molecule diol includes at least one of diethylene glycol, ethylene glycol, propylene glycol, triethylene glycol, dipropylene glycol, pentanediol, hexanediol, butanediol, octanediol, isoprene glycol, neopentyl glycol and 1,4-butene glycol;

[0020] Preferably, the molecular weight of the macromolecular polyol is between 200-10000;

[0021] Preferably, the first functional monomer comprises 2,2-dihydroxymethylpropionic acid;

[0022] Preferably, the hydrophilic polyol comprises at least one of polyethylene glycol monomethyl ether, polyethylene glycol and polyethylene glycol-polypropylene glycol block copolymer;

[0023] Preferably, the polyisocyanate includes at least one of isophorone diisocyanate, toluene diisocyanate, dicyclohexylmethane diisocyanate and xylylene diisocyanate;

[0024] Preferably, the organic amine comprises triethylamine.

[0025] Furthermore, in step (b), the raw materials for preparing the colorful continuous phase emulsion include the following components in parts by mass:

[0026] 45-60 parts of water, 17-20 parts of hard monomer, 18-21 parts of soft monomer, 1-3 parts of emulsifier, 0.1-0.7 parts of initiator, 0.1-0.2 parts of pH adjuster, 0.1-0.2 parts of defoamer, 0.1-0.2 parts of preservative, 1-10 parts of second functional monomer, and 5-10 parts of polyurethane prepolymer.

[0027] Further, the hard monomer includes at least one of styrene, methyl acrylate and methyl methacrylate;

[0028] Preferably, the soft monomer includes at least one of butyl acrylate, isooctyl acrylate and hydroxyethyl acrylate;

[0029] Preferably, the second functional monomer includes at least one of acrylic acid, acrylamide, glyceryl methacrylate, triethyltrimethoxysilane and γ-(methacryloyloxy)propyltrimethoxysilane.

[0030] In a second aspect, a colorful continuous phase emulsion is prepared by any of the preparation methods described above.

[0031] In a third aspect, a multi-colored coating is prepared using the multi-colored continuous phase emulsion described above.

[0032] In a fourth aspect, a method for preparing the multi-colored coating described above comprises the following steps:

[0033] Adding a chain extender to the colorful continuous phase emulsion to react, thereby obtaining the colorful coating;

[0034] The chain extender includes diethylenetriamine.

[0035] A fifth aspect is an application of the multi-colored paint described above in building decoration.

[0036] Compared with the prior art, the present invention has at least the following beneficial effects:

[0037] The invention provides a method for preparing a colorful continuous phase emulsion. Polyurethane is coated on the surface of latex particles to form a shell layer, and a silane coupling agent and a hydrophobic monomer are introduced into the shell layer to undergo a cross-linking reaction with the polyurethane, thereby improving the hydrophobicity and compactness of the polyurethane shell layer, which can effectively improve the water whitening resistance of the continuous phase emulsion.

[0038] The colorful continuous phase emulsion provided by the invention has good water whitening resistance and stability.

[0039] The multi-colored coating provided by the invention has good water-whitening resistance stability and better color and gloss.

[0040] The preparation method of the multi-color coating provided by the present invention comprises adding a chain extender during the coating preparation process to react and cross-link with the polyurethane shell layer, thereby forming a dense insulating layer, thereby effectively isolating the core layer from erosion during the soaking process, effectively avoiding the problem of the coating turning white when soaked in water, and further improving the water-whitening resistance of the multi-color coating.

[0041] The application of the multi-colored coating provided by the present invention can achieve outstanding application effects. DETAILED DESCRIPTION

[0042] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] In the prior art, the emulsion used in the multi-color coating usually optimizes the water whitening stability with a classic core-shell structure, but the coverage rate of the shell layer of the emulsion prepared by the classic core-shell structure on the core layer is low, which results in the fact that the water whitening performance of the multi-color coating is not significantly improved, the construction effect is poor, and some drawbacks of the paint film are formed; although the styrene acrylic emulsion has the characteristics of a strong three-dimensional sense of the product and good appearance texture, its water whitening stability is not good; therefore, if the styrene acrylic emulsion is well used in the multi-color coating, the problem of poor water whitening resistance of the multi-color continuous phase emulsion must be solved. In view of this, the technical solution of the present invention is specially proposed.

[0044] According to a first aspect of the present invention, there is provided a method for preparing a colorful continuous phase emulsion, comprising the following steps:

[0045] (a) introducing a hydrophobic monomer and a silane coupling agent into the polyurethane shell layer to undergo a cross-linking reaction with the polyurethane to obtain a polyurethane prepolymer;

[0046] (b) reacting the polyurethane prepolymer obtained in step (a) through an interfacial polymerization process to obtain a colorful continuous phase emulsion.

[0047] In the preparation of polyurethane prepolymer, hydrophobic monomers and silane coupling agents are introduced into the polyurethane shell layer to undergo cross-linking reactions with the polyurethane, thereby improving the hydrophobicity and density of the polyurethane shell layer and solving the problem of the colorful continuous phase turning white when soaked in water. Then, the polyurethane prepolymer is prepared through an interfacial polymerization process to obtain a colorful continuous phase emulsion, thereby effectively improving the water-whitening resistance of the continuous phase emulsion.

[0048] In summary, the preparation method of the colorful continuous phase emulsion provided by the present invention is that polyurethane is coated on the surface of latex particles to form a shell layer, and a silane coupling agent and a hydrophobic monomer are introduced into the shell layer to undergo a cross-linking reaction with the polyurethane, thereby improving the hydrophobicity and density of the polyurethane shell layer, thereby achieving the purpose of effectively improving the water whitening resistance of the continuous phase emulsion.

[0049] In a preferred embodiment, the hydrophobic monomer includes but is not limited to at least one of lauryl methacrylate and tridecyl methacrylate.

[0050] In a preferred embodiment, the silane coupling agent includes but is not limited to at least one of vinyltriethoxysilane, γ(methacryloyloxy)propyltrimethoxysilane and vinyltrimethoxysilane.

[0051] The hydrophobic monomer and silane coupling agent in the present invention are more conducive to cross-linking reaction with polyurethane, and can further improve the hydrophobicity and compactness of the polyurethane shell layer.

[0052] In the present invention, the raw materials for preparing the polyurethane prepolymer include the following components in parts by mass:

[0053] 2-4 parts of small molecule diol, 6-12 parts of macromolecular polyol, 3-6 parts of first functional monomer, 3-5 parts of hydrophilic polyol, 55-80 parts of polyisocyanate, 3-5 parts of organic amine, 1-5 parts of silane coupling agent, and 2-8 parts of hydrophobic monomer.

[0054] Among them, the typical but non-limiting mass fractions of small molecule diols are, for example, 2 parts, 3 parts, and 4 parts; the typical but non-limiting mass fractions of macromolecular polyols are, for example, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, and 12 parts; the typical but non-limiting mass fractions of the first functional monomer are, for example, 3 parts, 4 parts, 5 parts, and 6 parts; the typical but non-limiting mass fractions of hydrophilic polyols are, for example, 3 parts, 4 parts, and 5 parts; the typical but non-limiting mass fractions of polyisocyanates are, for example, 55 parts, 60 parts, 65 parts, 70 parts, 75 parts, and 80 parts; the typical but non-limiting mass fractions of organic amines are, for example, 3 parts, 4 parts, and 5 parts; the typical but non-limiting mass fractions of silane coupling agents are, for example, 1 part, 2 parts, 3 parts, 4 parts, and 5 parts; the typical but non-limiting mass fractions of hydrophobic monomers are, for example, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, and 8 parts.

[0055] In a preferred embodiment, the small molecule diol includes but is not limited to at least one of diethylene glycol, ethylene glycol, propylene glycol, triethylene glycol, dipropylene glycol, pentanediol, hexanediol, butanediol, octanediol, isoprene glycol, neopentyl glycol and 1,4-butene glycol, which is beneficial to increase the polymerization reaction temperature and reduce the polymerization reaction viscosity.

[0056] In the present invention, the molecular weight of the macromolecular polyol may be between 200 and 10,000.

[0057] In a preferred embodiment, the first functional monomer includes but is not limited to 2,2-dihydroxymethylpropionic acid, which is conducive to transesterification or condensation reaction with other monomers to improve the strength, flexibility, chemical resistance and water resistance of the polyurethane shell layer.

[0058] In a preferred embodiment, the hydrophilic polyol includes but is not limited to at least one of polyethylene glycol monomethyl ether (MPEG), polyethylene glycol and polyethylene glycol-polypropylene glycol block copolymer, which is beneficial to improve the hydrophilicity of the polyurethane prepolymer, thereby increasing the coverage rate of the polyurethane shell layer on the core.

[0059] In a preferred embodiment, the polyisocyanate includes, but is not limited to, at least one of isophorone diisocyanate (IPDI), toluene diisocyanate (TDI), dicyclohexylmethane diisocyanate (HMDI) and xylylene diisocyanate (XDI).

[0060] In the present invention, organic amines include but are not limited to triethylamine (TEA), which are beneficial to promote the reaction between polyisocyanate and macromolecular polyol, accelerate the polymerization reaction rate, improve the mechanical properties, chemical stability, heat resistance, hardness, durability of the polyurethane shell layer, and improve the processing performance of the polyurethane shell layer.

[0061] A typical preparation method of a polyurethane prepolymer comprises the following steps:

[0062] S1: Add macromolecular polyol, hydrophilic polyol, first functional monomer, small molecular diol and hydrophobic monomer into a reaction container in sequence, dehydrate, cool to 90°C, and then add 2 / 3 of polyisocyanate to react for 5h;

[0063] S2: After reacting for 5 hours, slowly add the remaining 1 / 3 of the polyisocyanate and silane coupling agent into the reaction container and stir to dilute. After cooling to room temperature, add the organic amine and disperse at high speed for 10-15 minutes to obtain a polyurethane prepolymer for use.

[0064] In the preparation of polyurethane prepolymer, with the coordinated cooperation of various components and their steps, through the core-shell process design, polyurethane is coated on the surface of latex particles to form a shell layer, and silane coupling agent and hydrophobic monomer are introduced into the shell layer to cross-link with polyurethane to improve the hydrophobicity and density of the polyurethane shell layer, which can effectively improve the water whitening resistance of the continuous phase emulsion.

[0065] The obtained polyurethane prepolymer is added into the continuous phase emulsion polymerization process, and the colorful continuous phase emulsion is prepared by the interfacial polymerization process.

[0066] In a preferred embodiment, the raw materials for preparing the colorful continuous phase emulsion include the following components in parts by mass:

[0067] 45-60 parts of water, 17-20 parts of hard monomer, 18-21 parts of soft monomer, 1-3 parts of emulsifier, 0.1-0.7 parts of initiator, 0.1-0.2 parts of pH adjuster, 0.1-0.2 parts of defoamer, 0.1-0.2 parts of preservative, 1-10 parts of second functional monomer, and 5-10 parts of polyurethane prepolymer.

[0068] Typical but non-limiting weight fractions of water are, for example, 45 parts, 50 parts, 55 parts, and 60 parts; typical but non-limiting weight fractions of hard monomers are, for example, 17 parts, 18 parts, 19 parts, and 20 parts; typical but non-limiting weight fractions of soft monomers are, for example, 18 parts, 19 parts, 20 parts, and 21 parts; typical but non-limiting weight fractions of emulsifiers are, for example, 1 part, 2 parts, and 3 parts; typical but non-limiting weight fractions of initiators are, for example, 0.1 parts, 0.3 parts, 0.5 parts, and 0.7 parts; typical but non-limiting weight fractions of pH adjusters are, for example, 0.1 parts, 0.12 parts, 0.14 parts, 0.1 Typical but non-limiting mass portions of defoaming agent are, for example, 0.1 part, 0.12 part, 0.14 part, 0.16 part, 0.18 part, 0.2 part; typical but non-limiting mass portions of preservative are, for example, 0.1 part, 0.12 part, 0.14 part, 0.16 part, 0.18 part, 0.2 part; typical but non-limiting mass portions of the second functional monomer are, for example, 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts; typical but non-limiting mass portions of polyurethane prepolymer are, for example, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts.

[0069] In a preferred embodiment, the hard monomer includes but is not limited to at least one of styrene, methyl acrylate and methyl methacrylate, which is beneficial to improving the hardness, weather resistance, stain resistance and water resistance of the latex coating.

[0070] In a preferred embodiment, the soft monomer includes but is not limited to at least one of butyl acrylate, isooctyl acrylate and hydroxyethyl acrylate, which is beneficial to improving the flexibility, water resistance, cold cracking resistance and UV resistance of the emulsion coating.

[0071] In a preferred embodiment, the second functional monomer includes but is not limited to at least one of acrylic acid, acrylamide, methacrylate, triethyltrimethoxysilane and γ-(methacryloyloxy)propyltrimethoxysilane, which is beneficial to improve the stability of emulsion polymerization, improve the adhesion of the emulsion coating, and at the same time improve water resistance and scrub resistance.

[0072] In the raw materials for preparing the colorful continuous phase emulsion, the emulsifier can be at least one of anionic emulsifiers, nonionic emulsifiers and anionic non-emulsifiers; the initiator can be at least one of sodium persulfate, ammonium persulfate and potassium persulfate; the pH regulator can be at least one of ammonia water, AMP-95 and triethanolamine; the defoamer can be at least one of silicone defoamers and mineral oil defoamers; the preservative can be at least one of kason and BIT.

[0073] A typical preparation method of a colorful continuous phase emulsion comprises the following steps:

[0074] S1: Preparation of pre-emulsion: Mix and stir the emulsifier and water at room temperature and pressure for 10 minutes for later use;

[0075] S2: Preparation of mixed monomers: at room temperature and pressure, the hard monomer, the soft elastomer and the second functional monomer are mixed and stirred for 10 minutes for later use;

[0076] S3: Preparation of emulsion: at room temperature and pressure, add the mixed monomers of S2 to the pre-emulsion of S1 and mix and stir for 30 minutes for later use;

[0077] S4: Preparation of initiator solution: at normal temperature and pressure, mix water and initiator and stir until the initiator is completely dissolved, and set aside;

[0078] S5: At normal temperature and pressure, add water into the reactor, heat up to 85°C, add 1% of the solution obtained from S3 and 1 / 5 of the initiator solution obtained from S4, react for 15 minutes, wait for the temperature to stabilize at 85±1°C, start to drip the remaining S3 solution and the initiator solution of S4 (the dripping time is 3.5 hours), when the dripping is 2.5 hours, stop dripping the S3 solution and the initiator solution of S4, and start to keep warm for 30 minutes; then, add the polyurethane prepolymer to the S3 solution and stir for 20 minutes and continue to drip. After the dripping is completed for 1 hour, keep warm and mature for another 1 hour to ensure the monomer yield; then, cool to below 45°C, add pH adjuster, preservative and defoamer and stir for 10 minutes, filter the material to obtain a colorful continuous phase emulsion.

[0079] According to a second aspect of the present invention, there is provided a colorful continuous phase emulsion prepared by any of the preparation methods described above.

[0080] The colorful continuous phase emulsion provided by the invention has good water whitening resistance and stability.

[0081] According to a third aspect of the present invention, there is provided a multi-colored coating, which is prepared using the multi-colored continuous phase emulsion described above.

[0082] The multi-colored coating provided by the invention has good water-whitening resistance stability and better color and gloss.

[0083] According to a fourth aspect of the present invention, there is provided a method for preparing the multi-colored coating described above, comprising the following steps:

[0084] Adding a chain extender into a colorful continuous phase emulsion to react, thereby obtaining a colorful coating;

[0085] The chain extender includes but is not limited to diethylenetriamine.

[0086] The preparation method of the multi-color coating provided by the present invention comprises adding a chain extender during the coating preparation process to react and cross-link with the polyurethane shell layer, thereby forming a dense insulating layer, thereby effectively isolating the core layer from erosion during the soaking process, effectively avoiding the problem of the coating turning white when soaked in water, and further improving the water-whitening resistance of the multi-color coating.

[0087] In the present invention, the raw materials for preparing the multi-color coating include the following components by mass:

[0088] 10-20 parts of water, 0.1-1 parts of preservatives, 0.5-1 parts of cellulose, 0.1-1 parts of defoaming agents, 5-10 parts of film-forming aids, 0.5-1 parts of thickeners, 0.1-0.5 parts of pH regulators, 5-15 parts of chain extenders, and 65-75 parts of colorful continuous phase emulsions.

[0089] In the raw materials for preparing the colorful coating, the preservative can be at least one of Kathon, BIT10 and BIT20; the cellulose can be hydroxyethyl cellulose, specifically at least one of Ashland 250HBR and Akzo EHM500; the defoamer can be at least one of silicone defoamers, mineral oil defoamers and polyether modified defoamers; the film-forming aid can be at least one of dipropylene glycol butyl ether, dipropylene glycol methyl ether and ethylene glycol; the thickener can be at least one of Dow Chemical's RM8W and Shenzhen Mingjia's PU40W; the pH adjuster can be at least one of ammonia water, AMP-95 and triethanolamine; the chain extender can be a diethylenetriamine aqueous solution prepared by dissolving 9-10% diethylenetriamine in 89-90% deionized water.

[0090] A typical preparation method of a multi-color coating comprises the following steps:

[0091] S1: Add water to a mixing tank, set the speed to 1000-1500 r / min, add cellulose and stir for 10-15 minutes until it is uniform;

[0092] S2: Continue to add preservatives, defoamers and film-forming aids into the mixing tank in sequence, and continue to disperse at 300-600r / min for 5-10min;

[0093] S3: Add the pH regulator and the colorful continuous phase emulsion into the stirring tank in sequence, and continue to disperse at 500-800 r / min for 10-15 minutes;

[0094] S4: Continue to add thickener to the mixing tank and continue dispersing at 800-1200r / min for 10-15min;

[0095] S5: Keep the rotation speed at 800-1200r / min, add the chain extender into the mixing tank three times in sequence, with an interval of 5-10 minutes each time, to obtain a colorful coating.

[0096] In the preparation of the colorful coating, a chain extender is added to react with the polyurethane shell layer to cross-link, thereby forming a dense insulating layer, which can isolate moisture during the soaking process to prevent whitening, thereby effectively improving the water-resistant whitening stability of the colorful continuous phase; at the same time, the introduction of a chain extender into the polyurethane shell layer can also effectively increase the coverage of the shell layer to the core layer, further enhancing the water-resistant whitening ability of the colorful continuous phase; with the coordinated cooperation of each component and its steps, the colorful coating prepared by the present invention not only has strong water-resistant whitening stability, but also has a strong three-dimensional sense and good appearance texture.

[0097] In summary, the present invention effectively improves the water-whitening stability of styrene acrylic emulsion in colorful coatings on the basis of strong three-dimensional sense and good appearance texture through special polymerization process design, and also effectively improves the color and gloss of the coating; the present invention not only has a simple operation process, but also with the coordinated cooperation of various components and steps, the obtained colorful coating not only has good water resistance stability, good storage stability, good yellowing resistance and good weather resistance, but also has a strong three-dimensional sense, good appearance texture, and stable paint matching performance.

[0098] According to a fifth aspect of the present invention, there is provided a use of the above-mentioned multi-colored paint in building decoration.

[0099] The application of the multi-colored coating provided by the present invention can achieve outstanding application effects.

[0100] The present invention is further described below by way of examples. Unless otherwise specified, the materials in the examples are prepared according to existing methods or directly purchased from the market.

[0101] Example 1

[0102] This embodiment provides a multi-colored coating, which is prepared by the following method:

[0103] Step 1: Prepare polyurethane prepolymer. The raw materials and their mass fractions are shown in Table 1:

[0104] The preparation method of polyurethane prepolymer comprises the following steps:

[0105] S1: Add macromolecular polyol, hydrophilic polyol, functional monomer, small molecule diol and hydrophobic monomer into a reaction vessel in sequence, dehydrate, cool to 90°C, and then add 2 / 3 of polyisocyanate to react for 5 hours;

[0106] S2: After reacting for 5 hours, slowly add the remaining 1 / 3 of the polyisocyanate and silane coupling agent into the reaction container and stir, and after cooling to room temperature, add organic amine and disperse evenly to obtain a polyurethane prepolymer;

[0107] Table 1

[0108] Raw material type Specific substances Mass fraction Small molecule diols Diethylene glycol 3 Macromolecular polyols Polyethylene glycol monomethyl ether (MPEG1000) 7 Functional monomer 2,2-Dihydroxymethylpropionic acid 5 Hydrophilic polyols Polyethylene glycol monomethyl ether 4 Polyisocyanate Isophorone diisocyanate 70 Organic amine Triethylamine 4 Silane coupling agent Vinyltriethoxysilane 2 Hydrophobic monomer Dodecyl Methacrylate 5

[0109] Step 2: Prepare colorful continuous phase emulsion. The raw materials and their mass fractions are shown in Table 2:

[0110] The preparation method of the colorful continuous phase emulsion comprises the following steps:

[0111] S1: Preparation of pre-emulsion: Mix and stir the emulsifier and water at room temperature and pressure for 10 minutes for later use;

[0112] S2: Preparation of mixed monomers: at room temperature and pressure, the hard monomer, the soft elastomer and the second functional monomer are mixed and stirred for 10 minutes for later use;

[0113] S3: Preparation of emulsion: at room temperature and pressure, add the mixed monomers of S2 to the pre-emulsion of S1 and mix and stir for 30 minutes for later use;

[0114] S4: Preparation of initiator solution: at normal temperature and pressure, mix water and initiator and stir until the initiator is completely dissolved, and set aside;

[0115] S5: At room temperature and pressure, add water to the reactor, heat it to 85°C, add 1% of the solution obtained from S3 and 1 / 5 of the initiator solution obtained from S4, react for 15 minutes, wait for the temperature to stabilize at 85±1°C, start dripping the remaining solution of S3 and the initiator solution of S4 (dropping time is 3.5 hours), when the dripping is 2.5 hours, stop dripping the solution of S3 and the initiator solution of S4, and start keeping warm for 30 minutes; then, add the polyurethane prepolymer to the solution of S3 and stir for 20 minutes and continue dripping. After the dripping is completed for 1 hour, keep warm and mature for another 1 hour to ensure the monomer yield; then, cool to below 45°C, add pH adjuster, preservative and defoamer and stir for 10 minutes, filter the material to obtain a colorful continuous phase emulsion;

[0116] Table 2

[0117] Raw material type Specific substances Mass fraction water Deionized water (conductivity <10μS / cm) 50 Hard monomer Styrene 18 Soft monomer Butyl acrylate 19 Emulsifier Anionic emulsifier 2 Initiator Sodium Persulfate 0.4 pH Adjusters ammonia 0.2 Defoaming agent Silicone defoamer 0.2 preservative Casson 0.2 Functional monomer acrylic acid 3 Polyurethane prepolymer The polyurethane prepolymer obtained in the first step 7

[0118] Step 3: Prepare colorful coatings. The raw materials and their mass fractions are shown in Table 3:

[0119] The preparation method of the multi-color coating comprises the following steps:

[0120] S1: Add water to the mixing tank, set the speed to 1300r / min, add cellulose and stir for 13 minutes until it is uniform;

[0121] S2: Continue to add preservatives, defoamers and film-forming aids into the mixing tank in sequence, and continue to disperse at 500 r / min for 8 minutes;

[0122] S3: Add the pH regulator and the colorful continuous phase emulsion into the mixing tank in sequence, and continue to disperse at 600 r / min for 13 min;

[0123] S4: Continue to add thickener to the mixing tank and continue dispersing at 1000r / min for 13min;

[0124] S5: Keep the rotation speed at 1000r / min, add the chain extender into the mixing tank three times in sequence, with an interval of 8 minutes each time, to obtain a colorful coating.

[0125] Table 3

[0126] Raw material type Specific substances Mass fraction water Deionized water (conductivity <10μS / cm) 10 preservative Casson 0.5 Cellulose Hydroxyethyl Cellulose 0.5 Defoaming agent Silicone defoamer 0.5 Film-forming aids Dipropylene glycol butyl ether 7.5 Thickener Shenzhen Mingjia's PU40W 0.5 pH Adjusters ammonia 0.5 Chain Extender Diethylenetriamine aqueous solution (mass concentration 10%) 10 Colorful continuous phase emulsion The colorful continuous phase emulsion obtained in the second step 70

[0127] Example 2

[0128] The difference between this embodiment and embodiment 1 is that in the first step, the hydrophobic monomer used is tridecyl methacrylate;

[0129] The remaining steps and process parameters are the same as those in the embodiment to obtain a multi-colored coating.

[0130] Example 3

[0131] The difference between this embodiment and embodiment 1 is that in the first step, the silane coupling agent is γ (methacryloyloxy) propyl trimethoxy silane;

[0132] The remaining steps and process parameters are the same as those in the embodiment to obtain a multi-colored coating.

[0133] Example 4

[0134] The difference between this embodiment and embodiment 1 is that in the first step, the silane coupling agent is vinyltrimethoxysilane;

[0135] The remaining steps and process parameters are the same as those in the embodiment to obtain a multi-colored coating.

[0136] Example 5

[0137] The difference between this embodiment and embodiment 1 is that, in the first step, the raw materials for preparing the polyurethane prepolymer and their mass fractions are shown in Table 4;

[0138] Table 4

[0139] Raw material type Specific substances Mass fraction Small molecule diols Ethylene glycol 3 Macromolecular polyols Polyethylene glycol-polypropylene glycol block copolymer 9 Functional monomer 2,2-Dihydroxymethylpropionic acid 5 Hydrophilic polyols Polyethylene glycol 4 Polyisocyanate Dicyclohexylmethane diisocyanate 67 Organic amine Triethylamine 4 Silane coupling agent Vinyltriethoxysilane 3 Hydrophobic monomer Dodecyl Methacrylate 5

[0140] The remaining steps and process parameters are the same as those in the embodiment to obtain a multi-colored coating.

[0141] Example 6

[0142] The difference between this embodiment and embodiment 1 is that in the first step, the raw materials for preparing the polyurethane prepolymer and their mass fractions are shown in Table 5;

[0143] Table 5

[0144] Raw material type Specific substances Mass fraction Small molecule diols Triethylene glycol 4 Macromolecular polyols Polyethylene glycol monomethyl ether (MPEG2000) 12 Functional monomer 2,2-Dihydroxymethylpropionic acid 6 Hydrophilic polyols Polyethylene glycol monomethyl ether 5 Polyisocyanate Xylylene diisocyanate 55 Organic amine Triethylamine 5 Silane coupling agent Vinyltrimethoxysilane 5 Hydrophobic monomer Tridecyl Methacrylate 8

[0145] The remaining steps and process parameters are the same as those in the embodiment to obtain a multi-colored coating.

[0146] Example 7

[0147] The difference between this embodiment and embodiment 1 is that in the second step, the raw materials for preparing the colorful continuous phase emulsion and their mass fractions are shown in Table 6;

[0148] Table 6

[0149] Raw material type Specific substances Mass fraction water Deionized water (conductivity <10μS / cm) 45 Hard monomer Methyl acrylate 20 Soft monomer 2-Ethylhexyl acrylate 21 Emulsifier Nonionic emulsifier 2 Initiator Ammonium Persulfate 0.4 pH Adjusters AMP-95 0.2 Defoaming agent Silicone defoamer 0.2 preservative BIT 0.2 Functional monomer Acrylamide 1 Polyurethane prepolymer The polyurethane prepolymer obtained in the first step 10

[0150] The remaining steps and process parameters are the same as those in the embodiment to obtain a multi-colored coating.

[0151] Example 8

[0152] The difference between this embodiment and embodiment 1 is that in the second step, the raw materials for preparing the colorful continuous phase emulsion and their mass fractions are shown in Table 7;

[0153] Table 7

[0154] Raw material type Specific substances Mass fraction water Deionized water (conductivity <10μS / cm) 55 Hard monomer Methyl Methacrylate 17 Soft monomer Hydroxyethyl acrylate 18 Emulsifier Nonionic emulsifier 2 Initiator Potassium Persulfate 0.4 pH Adjusters Triethanolamine 0.2 Defoaming agent Mineral oil defoamer 0.2 preservative Casson 0.2 Functional monomer Glyceryl Methacrylate 2 Polyurethane prepolymer The polyurethane prepolymer obtained in the first step 5

[0155] The remaining steps and process parameters are the same as those in the embodiment to obtain a multi-colored coating.

[0156] Example 9

[0157] The difference between this embodiment and embodiment 1 is that in the third step, the raw materials for preparing the multi-color coating and their mass fractions are shown in Table 8;

[0158] Table 8

[0159] Raw material type Specific substances Mass fraction water Deionized water (conductivity <10μS / cm) 15 preservative Casson 1 Cellulose Hydroxyethyl Cellulose 1 Defoaming agent Silicone defoamer 1 Film-forming aids Dipropylene glycol methyl ether 10 Thickener Shenzhen Mingjia's PU40W 1 pH Adjusters Triethanolamine 0.5 Chain Extender Diethylenetriamine aqueous solution (mass concentration 10%) 5.5 Colorful continuous phase emulsion The colorful continuous phase emulsion obtained in the second step 65

[0160] The remaining steps and process parameters are the same as those in the embodiment to obtain a multi-colored coating.

[0161] Example 10

[0162] The difference between this embodiment and embodiment 1 is that in the third step, the raw materials for preparing the multi-color coating and their mass fractions are shown in Table 9;

[0163] Table 9

[0164] Raw material type Specific substances Mass fraction water Deionized water (conductivity <10μS / cm) 10 preservative Casson 1 Cellulose Hydroxyethyl Cellulose 1 Defoaming agent Silicone defoamer 1 Film-forming aids Ethylene glycol 6 Thickener Shenzhen Mingjia's PU40W 0.5 pH Adjusters AMP-95 0.5 Chain Extender Diethylenetriamine aqueous solution (mass concentration 10%) 15 Colorful continuous phase emulsion The colorful continuous phase emulsion obtained in the second step 65

[0165] The remaining steps and process parameters are the same as those in the embodiment to obtain a multi-colored coating.

[0166] Comparative Example 1

[0167] The difference between this comparative example and Example 1 is that no hydrophobic monomer is added during the preparation of the polyurethane prepolymer in the first step;

[0168] The remaining steps and process parameters are the same as those in the embodiment to obtain a multi-colored coating.

[0169] Comparative Example 2

[0170] The difference between this comparative example and Example 1 is that no silane coupling agent is added during the preparation of the polyurethane prepolymer in the first step;

[0171] The remaining steps and process parameters are the same as those in the embodiment to obtain a multi-colored coating.

[0172] Comparative Example 3

[0173] The difference between this comparative example and Example 1 is that in the third step, no chain extender is added during the preparation of the multi-colored coating;

[0174] The remaining steps and process parameters are the same as those in the embodiment to obtain a multi-colored coating.

[0175] Comparative Example 4

[0176] The difference between this comparative example and Example 1 is that in the third step, during the preparation of the multi-colored coating, the chain extender is replaced by an equal amount of hexamethylenediamine in place of diethylenetriamine;

[0177] The remaining steps and process parameters are the same as those in the embodiment to obtain a multi-colored coating.

[0178] Test example

[0179] The performance of the multi-colored coatings obtained in Examples 1-10 and Comparative Examples 1-4 was tested, and the results are shown in Table 10.

[0180] Performance test method: Refer to GB / T1733-1993 Method A for testing, the method is as follows:

[0181] Plate making: Plates are made in parallel on glass plates (at least two plates) and the film is pushed with a 100 micron wire rod;

[0182] Initial water whitening resistance: After drying at room temperature for 24 hours, soak in water for 24 hours; observe and record the water whitening during the soaking process;

[0183] Water resistance: After drying at room temperature for 96 hours, soak in water for 96 hours; observe and record the water whitening during the soaking process;

[0184] Recovery: If the water becomes white, take it out of the water and record how long it takes to return to normal.

[0185] Score different whitening conditions (1-5 points, 1 point is the worst, 5 points is the best):

[0186]

[0187] Table 10

[0188]

[0189] It can be seen from the performance data recorded in Table 10 that the present invention prepares a colorful continuous phase emulsion and a colorful coating through a special process. The first step is to prepare a polyurethane prepolymer, introduce a hydrophobic monomer and a silane coupling agent into the polyurethane shell layer, and cross-link with the polyurethane to improve the hydrophobicity and density of the polyurethane shell layer, effectively solving the problem of the colorful continuous phase turning white when soaked in water. The second step is to prepare a colorful continuous phase emulsion through an interfacial polymerization process. The third step is to add a chain extender during the coating preparation process to react with the polyurethane shell layer and cross-link to form a dense insulating layer and improve the coverage rate of the polyurethane shell layer, effectively solving the problem of the colorful continuous phase turning white when soaked in water.

[0190] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a colorful continuous phase emulsion, characterized in that: The following steps are involved: (a) introducing a hydrophobic monomer and a silane coupling agent into the polyurethane shell layer to undergo a cross-linking reaction with the polyurethane to obtain a polyurethane prepolymer; (b) reacting the polyurethane prepolymer obtained in step (a) through an interfacial polymerization process to obtain the colorful continuous phase emulsion.

2. The preparation method according to claim 1, characterized in that: The hydrophobic monomer includes at least one of dodecyl methacrylate and tridecyl methacrylate; Preferably, the silane coupling agent includes at least one of vinyltriethoxysilane, γ(methacryloyloxy)propyltrimethoxysilane and vinyltrimethoxysilane.

3. The preparation method according to claim 1 or 2, characterized in that: In step (a), the raw materials for preparing the polyurethane prepolymer include the following components in parts by mass: 2-4 parts of small molecule diol, 6-12 parts of macromolecular polyol, 3-6 parts of first functional monomer, 3-5 parts of hydrophilic polyol, 55-80 parts of polyisocyanate, 3-5 parts of organic amine, 1-5 parts of silane coupling agent, and 2-8 parts of hydrophobic monomer.

4. The preparation method according to claim 3, characterized in that: The small molecule diol includes at least one of diethylene glycol, ethylene glycol, propylene glycol, triethylene glycol, dipropylene glycol, pentanediol, hexanediol, butanediol, octanediol, isoprene glycol, neopentyl glycol and 1,4-butene glycol; Preferably, the molecular weight of the macromolecular polyol is between 200-10000; Preferably, the first functional monomer comprises 2,2-dihydroxymethylpropionic acid; Preferably, the hydrophilic polyol comprises at least one of polyethylene glycol monomethyl ether, polyethylene glycol and polyethylene glycol-polypropylene glycol block copolymer; Preferably, the polyisocyanate includes at least one of isophorone diisocyanate, toluene diisocyanate, dicyclohexylmethane diisocyanate and xylylene diisocyanate; Preferably, the organic amine comprises triethylamine.

5. The preparation method according to claim 1 or 2, characterized in that: In step (b), the raw materials for preparing the colorful continuous phase emulsion include the following components in parts by mass: 45-60 parts of water, 17-20 parts of hard monomer, 18-21 parts of soft monomer, 1-3 parts of emulsifier, 0.1-0.7 parts of initiator, 0.1-0.2 parts of pH adjuster, 0.1-0.2 parts of defoamer, 0.1-0.2 parts of preservative, 1-10 parts of second functional monomer, and 5-10 parts of polyurethane prepolymer.

6. The preparation method according to claim 5, characterized in that: The hard monomer includes at least one of styrene, methyl acrylate and methyl methacrylate; Preferably, the soft monomer includes at least one of butyl acrylate, isooctyl acrylate and hydroxyethyl acrylate; Preferably, the second functional monomer includes at least one of acrylic acid, acrylamide, glyceryl methacrylate, triethyltrimethoxysilane and γ-(methacryloyloxy)propyltrimethoxysilane.

7. A colorful continuous phase emulsion prepared by the preparation method according to any one of claims 1 to 6.

8. A multi-colored paint, characterized in that: The multicolored continuous phase emulsion is prepared by using the multicolored continuous phase emulsion described in claim 7.

9. A method for preparing the multi-color coating according to claim 8, characterized in that: The following steps are involved: Adding a chain extender to the colorful continuous phase emulsion to react, thereby obtaining the colorful coating; The chain extender includes diethylenetriamine.

10. Use of the multi-colored paint according to claim 8 in building decoration.

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