Safe and environment-friendly water-based paint and preparation method thereof

Abstract

The invention discloses a safe and environment-friendly water-based paint and a preparation method thereof.A methoxy group on a red molecular structure of pigment 146 is modified into a phenolic hydroxyl group through a chemical modification method; the modified 146 red with the phenolic hydroxyl group is introduced in the process of synthesizing polyurethane, and the pigment is combined with resin in a chemical bond mode, so that the physical resistances such as adhesion, hardness and water resistance of the pigment on a base material can be greatly improved. The essence polymer is prepared by using cyclodextrin coated essence as a seed phase and carrying out in-situ polymerization to obtain an essence-cyclodextrin-polymer; meanwhile, the same essence is introduced into a monomer dropwise adding phase, so that volatilization of the essence in the high-temperature polymerization process can be effectively inhibited, and the embedding effect of cyclodextrin on the essence is ensured. When the essence polymer is used as an essence adding system of the water-based paint, the long-range essence release property of the water-based paint can be effectively controlled.

Description

Technical Field

[0001] The present invention relates to a waterborne coating and a preparation method thereof, and particularly relates to a safe and environment-friendly waterborne coating and a preparation method thereof. Background Art

[0002] In an aqueous system, the problem of poor compatibility between the high polarity of resins (such as aqueous acrylate and polyurethane) and pigments is essentially due to the adsorption competition and thermodynamic instability caused by the mismatch of the interfacial energy between the resin and the pigment. Conventional dispersants (such as anionic wetting agents) are difficult to maintain dispersion stability for a long time only through electrostatic repulsion. Especially during the film-forming process, as water volatilizes and the resin crosslinks, the van der Waals force and capillary force between particles exacerbate agglomeration.

[0003] The difference in the release behavior of aromatic substances between traditional coatings and waterborne coatings essentially stems from the interaction difference between the characteristics of the liquid carrier and the internal structure of the cured material. Traditional coatings rely on specific types of liquid media, and such media have the physical property of slow evaporation. Their release mechanism is based on the concentration difference-driven process formed by the staged evaporation of the liquid medium. This system promotes the transfer of aromatic substances from the liquid state to the gaseous state at a specific rhythm by maintaining the dynamic balance of the medium concentration in the liquid surface area, thereby realizing the continuous release of odor. In contrast, the aqueous system uses ordinary water as the main liquid component, and its fast evaporation characteristic breaks the gradual change of concentration, resulting in the rapid formation of a solid isolation layer on the liquid surface layer, causing the concentrated loss of aromatic substances.

[0004] The difference in the internal structure of the cured material further deepens this distinction: traditional coatings form a tightly connected molecular structure during the drying process, and this structure restricts the movement path of small molecules through physical barrier effects; while waterborne coatings produce a porous structure formed by the accumulation of tiny particles during curing, and this structure contains a large number of interconnected microscopic channels, significantly improving the movement efficiency of small molecules. Research on the surface characteristics of materials shows that the interaction between specific chemical groups existing on the surface of waterborne coatings after curing and aromatic substances is weak, and this insufficient compatibility phenomenon causes aromatic substances to be more likely to aggregate towards the surface. At the same time, the change in the surface force field caused by the rapid evaporation of the liquid component further strengthens the tendency of small molecules to migrate towards the surface layer. Summary of the Invention

[0005] In view of the deficiencies of the prior art, the present invention provides a safe and environment-friendly waterborne coating and a preparation method thereof. Using polymer macromolecule type pigments as colorants and polymer-coated fragrances as a fragrance slow-release system, and at the same time adopting an aqueous environmental protection system, a waterborne coating using polymer pigment / dye type colorants is developed. The waterborne coating prepared by the method of the present invention has a particle size as low as 453 nm, and has good stability, and the fragrance retention effect is significantly better than that of the coating directly added with essential oils.

[0006] One of the technical solutions of the present invention is to provide a preparation method of a safe and environmentally friendly waterborne coating, specifically: mixing 100 parts by weight of a macromolecular colorant, 10-20 parts by weight of a fragrance polymer, 2-4 parts by weight of a thickener, 1-3 parts by weight of a leveling agent, 1-4 parts by weight of a film-forming aid, 0.5-0.8 parts by weight of an antifoaming agent, and 20-30 parts by weight of pure water evenly.

[0007] Further, the macromolecular colorant is prepared through the following steps: Mix 100 parts of polypropylene glycol with a molecular weight of 2000, 4 parts of G 500 polyethylene glycol ether with a multi-molecular weight of 500, and 4 parts of B 11 / 150 polyalkylene monobutyl polyether with a molecular weight of 2500. Under stirring at 250 rpm, heat up to 70 °C for vacuum dehydration for 1 h, then add 54 parts of isophorone diisocyanate and 0.058 parts of dibutyltin dilaurate, and react at 85 °C for 2 h to obtain a prepolymer. Then cool down to 65 °C, then add 13 parts of 2,2-dimethylolpropionic acid, 1.5 parts of ethanolamine, and 85 parts of acetone, continue to react for 3.5 h, add 18 parts of the above-mentioned modified pigment red 146, increase the rotation speed to 1000 rpm, heat up to 90 °C and react for 2 h, then cool down to 50 °C and add 40 parts of acetone. Add the obtained polymer to 400 parts of pure water under high-speed stirring at 1500 rpm for dispersion and emulsification for 30 min, and finally heat up to 85 °C and maintain a stirring speed of 600 rpm to remove acetone to obtain a macromolecular colorant emulsion with a pH of 7.5-8.5.

[0008] Further, the modified pigment red 146 is prepared through the following steps: Stir and dissolve 10 g of NaOH in 90 g of pure water for later use. In a 500 mL three-necked flask, add 100 g of DMF, 100 g of pure water, and 2 g of the aforementioned red solid, stir and mix at a rotation speed of 1000 rpm at 45 °C, add 0.1 g of 1-dodecyl mercaptan, and slowly drop the aforementioned NaOH aqueous solution until the pH value of the system is between 7.5-8.5. Keep reacting at 45 °C for 16 h, detect the pH value of the system, and after reaching 7.5-8.5, perform suction filtration, washing, and drying to obtain the modified pigment red 146 red solid.

[0009] Further, the pigment red 146 is prepared through the following steps: Stir and dissolve 30 g of NaNO 2 in 70 g of pure water for later use. In a 500 mL three-necked flask, add 100 g of pure water, 6 g of HCl, and 5.0 g of 3-amino-4-methoxybenzoylaniline, stir and mix at a speed of 500 rpm for 1.5 h. Then place it in an ice-water bath and cool down to 5 °C, add the aforementioned prepared NaNO 2 solution, react for 40 min, then add an appropriate amount of urea and react until the system is neutral (detected using pH test paper). After the reaction is completed, perform suction filtration to obtain a yellow and clear diazo solution.

[0010] In a 500 mL three-necked flask, 80 g of pure water, 0.72 g of NaOH, and 3.2 g of N-(4-chloro-2,5-dimethoxyphenyl)-3-hydroxy-2-naphthamide were added, and the reaction was carried out at 90 °C for 1 h at a rotation speed of 600 rpm. Then it was placed in an ice-water bath and cooled to 5 °C, and the aforementioned yellow and clear diazo solution was slowly added dropwise into the flask using a constant-pressure dropping funnel. During the process, anhydrous sodium acetate was used to adjust the pH of the system to neutral (detected using pH test paper). After the dropping was completed, stirring was maintained for 1 h. Filtration was carried out, and it was washed with pure water at 60 - 70 °C until the washing liquid was neutral (detected using pH test paper), and then dried at 100 °C to obtain the red solid of Pigment Red 146.

[0011] Further, the essence polymer is obtained by the following preparation method: (1) 20 parts of β-hydroxypropyl cyclodextrin and 40 parts of pure water were stirred and dissolved in a water bath at 60 °C at a speed of 200 rpm, then cooled to room temperature, and 8 parts of myroxylon balsamum essential oil were slowly added dropwise within 2 h, the stirring speed was maintained at 100 rpm, and then it was kept warm for 1 h to obtain the essence@cyclodextrin coating solution.

[0012] (2) At room temperature, 5 parts of styrene monomer, 12 parts of n-butyl acrylate monomer, 4 parts of acrylic acid monomer, 2 parts of myroxylon balsamum essential oil, 0.4 part of emulsifier Emulsogen APG 2019, and 8 parts of deionized water were mixed and stirred and dissolved at a speed of 400 rpm for 40 min to obtain the monomer dropping phase.

[0013] (3) The temperature of the essence@cyclodextrin coating solution was raised to 80 °C, the stirring speed was adjusted to 150 rpm, and after 15 min, the monomer dropping phase and the initiator aqueous solution were simultaneously added dropwise, and the dropping time was 3 h. The initiator aqueous solution was prepared by dissolving 0.2 part of sodium persulfate in 4 parts of pure water. After the monomer dropping phase and the initiator aqueous solution were simultaneously added dropwise completely, it was kept warm and stirred for 1 h to obtain the polymerization reaction solution; the polymerization reaction solution was cooled to 70 °C, an aqueous solution of tert-butyl hydroperoxide was added, and the aqueous solution of tert-butyl hydroperoxide was obtained by dissolving 0.06 part of tert-butyl hydroperoxide in 0.6 part of pure water, and it was kept warm and stirred for 10 min, then an aqueous solution of Rongalite was added, and the aqueous solution of Rongalite was obtained by dissolving 0.06 part of Rongalite in 0.6 part of pure water, and it was kept warm and stirred for 10 min, then it was cooled to room temperature, an aqueous solution of preservative was added, and the aqueous solution of preservative was obtained by adding 0.03 weight part of DeuAddMB-11 to 0.2 part of pure water, 0.5 part of multifunctional auxiliary agent (AMP-95) was added dropwise, and finally it was filtered and discharged to obtain the essence polymer.

[0014] The thickener is one or more of polyurethane thickeners, cellulose thickeners, polyacrylic acid thickeners, and polyacrylate thickeners; preferably polyacrylic acid or polyacrylate thickeners.

[0015] Polyurethane thickeners include 8020, Longshida Chemical Technology Co., Ltd.; RHEOLATE® 216, King Industries, Inc.; DeuRheo WT-105A, King Industries, Inc.; DeuRheo WT-201, King Industries, Inc.; DeuRheo WT-202, King Industries, Inc.; DeuRheo WT-204, King Industries, Inc., etc.

[0016] Cellulose thickeners include CELLOSIZETM QP 4400H, Dow Chemical Company; CELLOSIZETM QP15000H, Dow Chemical Company; CELLOSIZETM QP 30000H, Dow Chemical Company; CELLOSIZETM QP 52000H, Dow Chemical Company; CELLOSIZETM QP 100MH, Dow Chemical Company; CELLOSIZETM ER 30M, Dow Chemical Company; CELLOSIZETM ER 52M, Dow Chemical Company, etc.

[0017] Polyacrylic acid thickeners include DeuRheo WT-113, King Industries, Inc.; DeuRheo WT-115, King Industries, Inc.; DeuRheo WT-120, King Industries, Inc., etc.

[0018] The leveling agent can be a polyacrylate leveling agent (such as A900, Milliken Chemical Co., Ltd.; Resiflow W50, BYK), a silicone resin leveling agent (such as Silcn 353, Shanghai Deyu Trade Co., Ltd.), a fluoroolefin leveling agent (such as 5100, Longshida Chemical Technology Co., Ltd.) or a mixture of any two or more of them in any proportion; preferably polyacrylate leveling agent.

[0019] The film-forming auxiliary agent is TEXANOL alcohol ester 12 (Eastman Chemical Company).

[0020] The defoamer is a modified silicone defoamer, such as: FoamStar® SI 2293 (BASF), FoamStar® SI 2213 (BASF), FoamStar® SI 2210 (BASF), FoamStar® SI 2240 (BASF), FoamStar® SI 2250 (BASF), FoamStar® SI 2280 (BASF), and FoamStar® SI 2250 (BASF) is particularly preferred.

[0021] The conductivity of the purified water is not more than 10 us / cm (25 °C).

[0022] In the present invention, the preparation of the macromolecular colorant is carried out by a chemical modification method, in which the methoxy group on the 146 red molecular structure is modified into a phenolic hydroxyl group; and the modified 146 red with phenolic hydroxyl group is introduced during the synthesis of polyurethane: on the molecular structure of polyurethane, there are multiple groups that can react with phenolic hydroxyl groups. It includes multiple epoxy groups on the main chain derived from G 500 polyethylene glycol - G - glycidyl ether and B 11 / 150 polyalkylene monobutyl polyether - ethylene oxide / propylene oxide random copolymer (ethylene oxide / propylene oxide ratio is 1:1 end - functional group), -NCO groups on the molecular chain ends, and carboxyl groups remaining after partial neutralization of the carboxyl groups on 2,2 - dimethylolpropionic acid (a small amount of organic amine is added). These groups can all react with the phenolic hydroxyl groups on the modified 146 red to chemically graft 146 red into the polyurethane main chain. The pigment is combined with the resin in a chemical bond - and manner, which can greatly improve the physical resistance such as the adhesion, hardness, and water resistance of the pigment on the substrate. The fragrance polymer is obtained by using cyclodextrin - coated fragrance as the seed phase and carrying out in - situ polymerization to obtain fragrance@cyclodextrin@polymer; at the same time, the same fragrance is introduced into the monomer dropping phase, which can effectively inhibit the volatilization of the fragrance during the high - temperature polymerization process and ensure the encapsulation effect of cyclodextrin on the fragrance. Using this fragrance polymer as the fragrance addition system for the coating can effectively control the long - range fragrance release property of the coating.

[0023] The second technical solution of the present invention lies in providing a safe and environmentally friendly water - borne coating prepared by the above method.

[0024] The beneficial effects of the present invention are as follows: An environmentally friendly and safe water - borne system is adopted, and a self - made macromolecular colorant is used as the coloring main body, and the system shows better gloss, adhesion, pencil hardness, water resistance and other properties than commercially available products; a self - made polymer - coated fragrance system is used, and the system shows far better long - range fragrance slow - release performance than commercially available products. Description of the Drawings

[0025] Figure 1 It is the effect of Example 1 of the present invention applied to the nail. Detailed implementation manners

[0026] The following examples are used to further illustrate the present invention. The purpose is to explain the present invention rather than to limit the scope of the present invention. Unless otherwise specified, weight parts and weight percentages are used hereinafter.

[0027] The raw materials used in the present invention are all conventional commercially available products unless otherwise specified; the methods used in the present invention are all conventional methods in the art unless otherwise specified.

[0028] The B 11 / 150 polyalkylene monobutyl polyether described in the present invention is a random copolymer of ethylene oxide / propylene oxide, and the ratio of ethylene oxide (EO) / propylene oxide (PO) is 1:1; the end groups are butoxy and hydroxyl groups.

[0029] The particle size test of the coating is carried out on a Malvern ZETASIZER 3000 HAS particle size analyzer, and the test temperature is 25°C.

[0030] The storage stability of the coating refers to that the coating is left standing at 60°C for 18 days, and no precipitation and no stratification represent that the storage stability of the coating > 12 months.

[0031] The glossiness test of the coating refers to scraping a film on a glass slide with a 100um wire bar at room temperature, drying it in a 50°C forced air drying oven, and then measuring it with a 60° glossiness meter.

[0032] The drying time of the coating is measured by the finger-touch method in a constant temperature and humidity chamber at 65% RH and 25°C.

[0033] The adhesion test of the coating is carried out according to GB / T 13217.7-2009. If the adhesion fastness ≥ 95%, it can be considered that the adhesion fastness of the coating is excellent.

[0034] The hardness test of the coating is carried out according to GB / T 6739-2006.

[0035] The water resistance test of the coating is carried out according to GB / T 1733-1993.

[0036] The fragrance slow-release function of the coating is carried out according to QB / T 2929-2021. The initial fragrance release concentration is set at 100%, and the fragrance release concentration is measured regularly later. The higher the ratio of the latter to the former, the better the slow-release effect.

[0037] The molecular weights described in the present invention are all number-average molecular weights, and the unit is g / mol.

[0038] The following further illustrates the embodiments of the present invention with multiple examples.

[0039] It should be clear that the described embodiments are only a part of the embodiments of this application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of this application.

[0040] The terms used in the embodiments of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The singular forms "a", "the", and "said" used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0041] Example 1 1. Preparation of Pigment Red 146: Dissolve 30 g of NaNO 2 by stirring in 70 g of pure water for standby. In a 500 mL three-necked flask, add 100 g of pure water, 6 g of HCl, and 5.0 g of 3-amino-4-methoxybenzoylaniline, and stir and mix at a speed of 500 rpm for 1.5 h. Then place it in an ice-water bath to cool down to 5 °C, and add the aforementioned standby NaNO 2 solution. After reacting for 40 min, add an appropriate amount of urea and react until the system becomes neutral (detected using pH test paper). After the reaction is completed, filter by suction to obtain a yellow and clear diazo solution.

[0042] In a 500 mL three-necked flask, add 80 g of pure water, 0.72 g of NaOH, and 3.2 g of N-(4-chloro-2,5-dimethoxyphenyl)-3-hydroxy-2-naphthamide, and react at 90 °C at a rotation speed of 600 rpm for 1 h. Then place it in an ice-water bath to cool down to 5 °C, and slowly add the aforementioned yellow and clear diazo solution into the flask using a constant pressure dropping funnel. During the process, adjust the pH of the system to neutral with anhydrous sodium acetate (detected using pH test paper). After the dropping is completed, keep stirring for 1 h. Filter by suction, wash with pure water at 60-70 °C until the washing liquid becomes neutral (detected using pH test paper), and dry at 100 °C to obtain the red solid of Pigment Red 146.

[0043] Preparation of Modified Pigment Red 146: Dissolve 10 g of NaOH by stirring in 90 g of pure water for standby. In a 500 mL three-necked flask, add 100 g of DMF, 100 g of pure water, and 2 g of the aforementioned red solid, stir and mix at a rotation speed of 1000 rpm at 45 °C, add 0.1 g of 1-dodecanethiol, and slowly add the aforementioned NaOH aqueous solution until the pH value of the system is between 7.5 and 8.5. After reacting at 45 °C for 16 h, detect the pH value of the system. After reaching 7.5-8.5, filter by suction, wash, and dry to obtain the red solid of modified Pigment Red 146.

[0044] 3. Preparation of Macromolecular Colorants: In a four-necked flask equipped with an electric stirrer, a reflux condenser, and a mercury thermometer, 100 parts of polypropylene glycol with a molecular weight of 2000 (from Sinopharm Chemical Reagent Co., Ltd.), 4 parts of G 500 polyethylene glycol ether with a multi-molecular weight of 500 (from Clariant), and 4 parts of B 11 / 150 polyalkylene monobutyl polyether with a multi-molecular weight of 2500 (from Clariant) were added. Under stirring at 250 rpm, the temperature was raised to 70 °C for vacuum dehydration for 1 h. Then, 54 parts of isophorone diisocyanate (from Sinopharm Chemical Reagent Co., Ltd.) and 0.058 parts of dibutyltin dilaurate (from Jinan Dahui Chemical Technology Co., Ltd.) were added, and the reaction was carried out at 85 °C for 2 h to obtain a prepolymer. Then, the temperature was lowered to 65 °C, and then 13 parts of 2,2-dimethylolpropionic acid (from Sinopharm Chemical Reagent Co., Ltd.), 1.5 parts of ethanolamine (from Sinopharm Chemical Reagent Co., Ltd.), and 85 parts of acetone (from Sinopharm Chemical Reagent Co., Ltd.) were added. After continuing the reaction for 3.5 h, 18 parts of the above-mentioned modified pigment red 146 were added, the rotation speed was increased to 1000 rpm, and the temperature was raised to 90 °C for reaction for 2 h (pay attention to controlling the acetone reflux situation during the process). Then, the temperature was lowered to 50 °C, and 40 parts of acetone (from Sinopharm Chemical Reagent Co., Ltd.) were added. The obtained polymer was added to 400 parts of pure water dispersion milk under high-speed stirring at 1500 rpm for 30 min, and finally the temperature was raised to 85 °C and the stirring speed was maintained at 600 rpm to remove acetone to obtain a macromolecular colorant emulsion with a pH of 7.5 - 8.5.

[0045] The fragrance polymer is obtained through the following preparation method: (1) Preparation of the base phase: 20 parts of β-hydroxypropyl cyclodextrin (from Xi'an Cuibang Biotechnology Co., Ltd.) and 40 parts of pure water were stirred and dissolved in a water bath at 60 °C at a speed of 200 rpm, then cooled to room temperature, and 8 parts of peach wood essential oil were slowly added dropwise within 2 h, with the stirring speed maintained at 100 rpm, and then kept warm for 1 h to obtain a fragrance@cyclodextrin coating solution.

[0046] (2) Preparation of the dropping phase: At room temperature, 5 parts of styrene monomer (from Shanghai Hechuang Chemical Technology Co., Ltd.), 12 parts of n-butyl acrylate monomer (from Shanghai Hechuang Chemical Technology Co., Ltd.), 4 parts of acrylic acid monomer (from Shanghai Hechuang Chemical Technology Co., Ltd.), 2 parts of peach wood essential oil, 0.4 part of emulsifier Emulsogen APG 2019 (from Clariant), and 8 parts of deionized water were mixed and stirred and dissolved at a speed of 400 rpm for 40 min to obtain a monomer dropping phase.

[0047] (3) Polymerization: Raise the temperature of the primer phase to 80 °C, adjust the stirring speed to 150 rpm. After 15 min, simultaneously add dropwise the remaining monomer addition phase and the aqueous initiator solution over 3 h. The aqueous initiator solution is prepared by dissolving 0.2 part of sodium persulfate (Suzhou Huahang Chemical Technology Co., Ltd.) in 4 parts of pure water. After the monomer addition phase and the aqueous initiator solution are added dropwise simultaneously, keep stirring for 1 h to obtain a polymerization reaction solution; cool the polymerization reaction solution to 70 °C, add an aqueous tert-butyl hydroperoxide solution. The aqueous tert-butyl hydroperoxide solution is obtained by dissolving 0.06 part of tert-butyl hydroperoxide (Shanghai Baiyi Chemical Co., Ltd.) in 0.6 part of pure water, keep stirring for 10 min, then add an aqueous Rongalite solution. The aqueous Rongalite solution is obtained by dissolving 0.06 part of Rongalite (Shanghai Fengrui Chemical Co., Ltd.) in 0.6 part of pure water, keep stirring for 10 min, then cool to room temperature, add an aqueous preservative solution. The aqueous preservative solution is obtained by adding 0.03 part by weight of DeuAdd MB-11 (Deken Corporation) to 0.2 part of pure water, add dropwise 0.5 part of AMP-95 (Dow Chemical Company), and finally filter and discharge to obtain the essence polymer.

[0048] Mix 100 parts by weight of macromolecular colorant, 20 parts by weight of essence polymer, 2 parts by weight of thickener DeuRheo WT-113 (Deken Corporation), 2 parts by weight of leveling agent Resiflow W50 (BYK), 4 parts by weight of film-forming aid TEXANOL alcohol ester 12 (Eastman), 0.5 part by weight of defoaming agent FoamStar® SI 2250 (BASF), and 30 parts by weight of pure water and stir evenly. The average particle size of the obtained coating is as low as 453 nm, and it can be completely dried in 14 minutes, and there is still fragrance residue after 7 days of application.

[0049] Example 2 Mix 100 parts by weight of macromolecular colorant, 18 parts by weight of essence polymer, 3 parts by weight of thickener DeuRheo WT-113 (Deken Corporation), 1 part by weight of leveling agent Resiflow W50 (BYK), 2 parts by weight of film-forming aid TEXANOL alcohol ester 12 (Eastman), 0.5 part by weight of defoaming agent FoamStar® SI 2250 (BASF), and 20 parts by weight of pure water and stir evenly. The average particle size of the obtained coating is 487 nm.

[0050] Example 3 Mix 100 parts by weight of macromolecular colorant, 10 parts by weight of fragrance polymer, 4 parts by weight of thickener DeuRheo WT-113 (Dekang Company), 3 parts by weight of leveling agent Resiflow W50 (BYK Company), 1 part by weight of film-forming aid TEXANOL alcohol ester 12 (Eastman Company), 0.8 part by weight of defoamer FoamStar® SI 2250 (BASF Company), and 20 parts by weight of pure water and stir and mix them evenly. The average particle size of the obtained coating is 501 nm.

[0051] Example 4: Mix 100 parts by weight of macromolecular colorant, 15 parts by weight of fragrance polymer, 3 parts by weight of thickener DeuRheo WT-113 (Dekang Company), 2 parts by weight of leveling agent Resiflow W50 (BYK Company), 3 parts by weight of film-forming aid TEXANOL alcohol ester 12 (Eastman Company), 0.54 part by weight of defoamer FoamStar® SI 2250 (BASF Company), and 30 parts by weight of pure water and stir and mix them evenly. The average particle size of the obtained coating is 462 nm.

[0052] Table 1. Performance data of Examples 2 - 4

[0053] Comparative Example 1: The difference from Example 1 is that modified pigment red 146 was not added in Step 3. A polyurethane emulsion with a pH of 7.5 - 8.5 was finally prepared.

[0054] Add 20 parts of the above polyurethane emulsion to the dispersion kettle, start stirring, keep the rotation speed at 100 rpm, and then sequentially add 30 parts of pure water, 2 parts of BYK-190 dispersant (BYK Company), 0.04 part of DAPPO ® DF 3163 (Dekang Company) and 10 parts of pigment red 146, and stir and mix them evenly at a rate of 200 rpm and then transfer them to a horizontal sand mill, grind for 3 passes and then filter and discharge to obtain an aqueous color paste; then sequentially add the obtained aqueous color paste, 20 parts of the above polyurethane emulsion, 28 parts by weight of pure water, 0.8 part by weight of ANTI-TERRA-250 (BYK Company), and 0.06 part of DAPPO ® DF 3163 (Dekang Company) to the dispersion tank, stir at a rate of 150 rpm for 0.5 h and then filter and discharge to obtain a self-made PU + pigment red 146 colorant.

[0055] Mix 100 parts by weight of the self-made PU + Pigment Red 146 colorant, 20 parts by weight of the fragrance polymer, 2 parts by weight of the thickener DeuRheo WT-113 (Deken Corporation), 2 parts by weight of the leveling agent Resiflow W50 (BYK Corporation), 4 parts by weight of the film-forming aid TEXANOL alcohol ester 12 (Eastman Chemical Company), 0.5 part by weight of the defoaming agent FoamStar® SI 2250 (BASF Corporation), and 30 parts by weight of pure water, and stir and mix them evenly.

[0056] Comparative Example 2: The difference from Example 1 is that 146 red paste is used instead of the macromolecular colorant, and the addition amount of the fragrance polymer is increased. Specifically, it is 10 parts by weight of 146 red paste, 90 parts by weight of the fragrance polymer, 2 parts by weight of the thickener DeuRheo WT-113 (Deken Corporation), 2 parts by weight of the leveling agent Resiflow W50 (BYK Corporation), 4 parts by weight of the film-forming aid TEXANOL alcohol ester 12 (Eastman Chemical Company), 0.5 part by weight of the defoaming agent FoamStar® SI 2250 (BASF Corporation), and 30 parts by weight of pure water, and stir and mix them evenly.

[0057] Among them, the preparation method of 146 red paste is as follows: Add 30 parts of pure water, 4 parts of BYK-190 dispersant (BYK Corporation), 0.04 part of DAPPO ® DF 3163 (Deken Corporation) and 10 parts of Pigment Red 146 into the dispersion kettle in sequence, stir and mix them evenly at a rate of 200 rpm, then transfer them to a horizontal sand mill, grind for 3 passes, and filter and discharge to obtain an aqueous color paste.

[0058] Comparative Example 3: The difference from Comparative Example 1 is that peach wood essential oil is used to replace the fragrance polymer. Specifically, it is 100 parts by weight of the macromolecular colorant, 1 part by weight of peach wood essential oil, 2 parts by weight of the thickener DeuRheo WT-113 (Deken Corporation), 2 parts by weight of the leveling agent Resiflow W50 (BYK Corporation), 4 parts by weight of the film-forming aid TEXANOL alcohol ester 12 (Eastman Chemical Company), 0.5 part by weight of the defoaming agent FoamStar® SI 2250 (BASF Corporation), and 30 parts by weight of pure water, and stir and mix them evenly.

[0059] Table 2. Performance comparison of Example 1 and each comparative example

[0060] As shown in Table 2, Example 1 and Comparative Example 3 use homemade macromolecular colorants, and the coatings are superior to other systems in terms of adhesion, pencil hardness and water resistance; in addition, the particle size of the system in which the colorant Pigment Red 146 is chemically grafted and polymerized into the resin segment is significantly lower than the particle size obtained by physical grinding in other comparative examples and the particle size of commercially available nail polish, which is also the reason why the glossiness of the coating of Example 1 after film formation is significantly higher than that of other systems. In terms of drying time, Example 1 is slightly faster than commercially available nail polish products. In terms of sustained release of fragrance, the sustained release effect of the system using the homemade fragrance polymer of the invention is significantly better than the physical addition fragrance system (Comparative Example 3) and the commercially available fragrance nail polish system. Since Comparative Example 2 does not add macromolecular colorants, the system lacks a film-forming resin, and the sealing property of the fragrance is slightly worse than that of Example 1 and Comparative Example 2, so the release concentration in 7 days is less than that of the latter two. There is little difference in the long-range release of fragrance between Example 1 and Comparative Example 1. The above results show that the water-based environmentally friendly coating prepared by the present invention is superior to commercially available nail polish in terms of physical resistance and fragrance release, showing broad market prospects.

[0061] The above embodiments describe in detail the structure, features and effects of the present invention. The above are only preferred embodiments of the present invention. Any changes made in accordance with the concept of the present invention, or modifications to equivalent embodiments with equivalent changes, which do not exceed the scope covered by the specification, should be within the protection scope of the present invention.

Claims

1. A method for preparing a safe and environmentally friendly water-based coating, characterized in that: The invention comprises the following steps: 100 parts by weight of a macromolecular colorant, 10-20 parts by weight of a fragrance polymer, 2-4 parts by weight of a thickener, 1-3 parts by weight of a leveling agent, 1-4 parts by weight of a film-forming aid, 0.5-0.8 parts by weight of a defoamer and 20-30 parts by weight of purified water are stirred and uniformly mixed; the macromolecular colorant is prepared by the following steps: (1) mixing polypropylene glycol, polyethylene glycol ether and polyalkylene monobutyl polyether, adding isophorone diisocyanate and a catalyst after dehydration, and reacting to obtain a primary polymer; and (2) adding dimethylol propionic acid, ethanolamine and acetone, and then adding pigment red 146, and reacting to obtain the macromolecular colorant.

2. The preparation method according to claim 1, characterized in that: The macromolecular colorant is prepared by the following steps: (1) 100 parts of polypropylene glycol with a molecular weight of 2000, 4 parts of polyethylene glycol ether with a molecular weight of 500 and 4 parts of polyalkylene monobutyl polyether with a molecular weight of 2500 were mixed, heated to 70°C for vacuum dehydration for 1 hour under stirring at 250 rpm, and then 54 parts of isophorone diisocyanate and 0.058 parts of dibutyltin dilaurate were added, and the mixture was reacted at 85°C for 2 hours to obtain a primary polymer; (2) Cooling to 65°C, then adding 13 parts of 2,2-dihydroxymethylpropionic acid, 1.5 parts of ethanolamine and 85 parts of acetone, continuing the reaction for 3.5 hours, adding 18 modified pigment red 146, increasing the speed to 1000 rpm, heating to 90°C and reacting for 2 hours, cooling to 50°C, adding 40 parts of acetone to obtain a polymer; (3) The obtained polymer was added with 400 parts of pure water for dispersion and emulsification at 1500 rpm for 30 min. Finally, the temperature was raised to 85°C and the stirring speed was maintained at 600 rpm to remove acetone to obtain a macromolecular colorant emulsion with a pH of 7.5-8.

5.

3. The preparation method according to claim 2, characterized in that: The modified Pigment Red 146 is prepared by the following steps: 10g of NaOH is stirred and dissolved in 90g of pure water for standby use; 100g of DMF, 100g of pure water and 2g of Pigment Red 146 are stirred and mixed at 45°C at a speed of 1000rpm, 0.1g of 1-dodecyl mercaptan is added, and the aforementioned NaOH aqueous solution is slowly added dropwise until the pH value of the system is between 7.5-8.5; after maintaining the reaction at 45°C for 16h, the pH value of the system is detected, and after reaching 7.5-8.5, the modified Pigment Red 146 is obtained by suction filtration, washing and drying.

4. The preparation method according to claim 1, characterized in that: The fragrance polymer is obtained by the following preparation method: (1) 20 parts of β-hydroxypropyl cyclodextrin and 40 parts of purified water were stirred and dissolved in a 60°C water bath at a speed of 200 rpm, then cooled to room temperature, and 8 parts of myrtle essential oil were slowly added dropwise over a period of 2 hours, with the stirring speed maintained at 100 rpm, and then kept warm for 1 hour to obtain an essence@cyclodextrin coating liquid; (2) at room temperature, 5 parts of styrene monomer, 12 parts of n-butyl acrylate monomer, 4 parts of acrylic acid monomer, 2 parts of myrtle essential oil, 0.4 parts of emulsifier and 8 parts of deionized water were mixed and dissolved at a speed of 400 rpm for 40 minutes to obtain a monomer addition phase; (3) Raise the temperature of the flavor@cyclodextrin coating liquid to 80°C, adjust the stirring speed to 150rpm, and then simultaneously add the monomer addition phase and the initiator aqueous solution after 15min. The addition time is 3h. After the monomer addition phase and the initiator aqueous solution are added simultaneously, keep warm and stir for 1h to obtain a polymerization reaction liquid; the initiator aqueous solution is prepared by dissolving 0.2 parts of sodium persulfate in 4 parts of pure water; (4) The polymerization reaction liquid was cooled to 70° C., and an aqueous solution of tert-butyl hydroperoxide was added, and the mixture was stirred for 10 minutes at the temperature maintained. The aqueous solution of tert-butyl hydroperoxide was prepared by dissolving 0.06 parts of tert-butyl hydroperoxide in 0.6 parts of pure water; (5) adding Rongalite aqueous solution, stirring at temperature for 10 minutes, and then cooling to room temperature, wherein the Rongalite aqueous solution is obtained by dissolving 0.06 parts of Rongalite in 0.6 parts of pure water; (6) Add an aqueous preservative solution, dropwise add 0.5 parts of a multifunctional auxiliary agent, and finally filter out the material to obtain the flavor polymer; the aqueous preservative solution is obtained by adding 0.03 parts by weight of DeuAdd MB-11 to 0.2 parts of pure water; the multifunctional auxiliary agent is AMP-95.

5. The preparation method according to claim 1, characterized in that: The thickener is one or more of a polyurethane thickener, a cellulose thickener, a polyacrylic thickener, and a polyacrylate thickener.

6. The preparation method according to claim 1, characterized in that: The leveling agent is one or more of a polyacrylate leveling agent, a silicone resin leveling agent, and a fluoroolefin leveling agent.

7. The preparation method according to claim 1, characterized in that: The film-forming aid is TEXANOL alcohol ester dodecahydrate.

8. The preparation method according to claim 1, characterized in that: The defoamer is a modified siloxane defoamer.

9. The preparation method according to claim 1, characterized in that: The conductivity of the pure water at 25° C. is not greater than 10 us / cm.

10. A safe and environmentally friendly water-based coating prepared by the preparation method according to any one of claims 1 to 9.

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