Waterborne polyurethane for nail polish and method of making the same

Abstract

The application discloses a water-based polyurethane for nail polish and a preparation method thereof, and relates to the technical field of water-based polyurethane. The water-based polyurethane for nail polish comprises mixed polyols, polyisocyanate, functional monomers, a hydrophilic agent, a post-chain extender and deionized water, wherein the mixed polyols are a combination of polycaprolactone glycol, phthalic anhydride polyester polyol and polyether polyol, and the functional monomers comprise amino type furan monomers and amino type maleimide monomers. Through the technical scheme, the glossiness and surface hand feeling of the water-based polyurethane after film formation can be effectively improved, and the apparent quality and product value of the nail polish prepared from the water-based polyurethane are improved.

Description

Technical Field

[0001] This invention relates to the technical field of polymer materials, and in particular to a waterborne polyurethane for nail polish and its preparation method. Background Technology

[0002] As a commonly used beauty product, the performance of the film-forming material in nail polish directly affects the user experience. With increasingly stringent environmental regulations and rising health awareness, waterborne polyurethane, due to its low volatile organic compound (VOC) content and non-toxic and environmentally friendly characteristics, is gradually becoming an important alternative to solvent-based nail polish film-forming resins.

[0003] However, in practical applications, it has been found that waterborne polyurethane, after forming a nail polish film, exhibits a significant difference in surface condition and gloss compared to traditional solvent-based nail polish, directly impacting the nail polish's aesthetics, texture, and user experience. Because waterborne polyurethane uses water as the dispersion medium, the fusion and leveling of polymer particles during film formation are often insufficient. This results in microscopic unevenness on the final nail polish coating surface, leading to low gloss and difficulty in achieving the high-gloss, mirror-like effect characteristic of solvent-based nail polish. Furthermore, the introduction of hydrophilic groups or segments into waterborne polyurethane may cause a slight stickiness on the surface of the nail polish coating after drying or even complete curing. This not only results in a poor feel but also makes it more prone to dust accumulation, affecting aesthetics and durability, and further impacting the appearance quality and commercial value of waterborne polyurethane nail polish.

[0004] Therefore, how to fundamentally solve the problems of low gloss and stickiness of water-based polyurethane film while maintaining the environmental advantages of water-based systems has become a key challenge to enhance the competitiveness of water-based nail polish products and promote them to the high-end market. Summary of the Invention

[0005] In order to improve the problems of low gloss and poor surface feel of nail polish made of waterborne polyurethane after curing, and to improve the appearance quality and product value of nail polish, this application provides a nail polish made of waterborne polyurethane and a method for preparing the same.

[0006] Firstly, the water-based polyurethane nail polish provided in this application adopts the following technical solution: A nail polish made of water-based polyurethane comprises the following percentages of raw materials based on the total mixed mass of the water-based polyurethane: Mixed polyols: 30-35%; Polyisocyanates: 12-16%; Functional monomers: 0.66-0.75%; Hydrophilic agent: 1-1.6%; Chain extender: 1.2-2%; The remainder is deionized water; The mixed polyol is a composition of polycaprolactone diol, phthalic anhydride polyester polyol and polyether polyol, the polyisocyanate includes IPDI, and the functional monomer includes amino-type furanyl monomer and amino-type maleimide monomer.

[0007] By employing the above-mentioned technical solution, using specific mixed polyols and functional monomers in a specific ratio, the gloss and surface feel of waterborne polyurethane films can be effectively improved. The selection of mixed polyols facilitates better leveling and densification of the waterborne polyurethane during subsequent film formation, thereby improving film gloss while simultaneously enhancing surface hardness and reducing surface tackiness. The introduction of functional monomers not only synergistically increases the crosslinking density of the waterborne polyurethane with the mixed polyols and polyisocyanates, but also improves the surface properties of the film, resulting in a smoother coating and reduced tackiness, ultimately enhancing the appearance quality and product value of waterborne polyurethane nail polish.

[0008] Optionally, in the mixed polyols, the mass ratio of the polycaprolactone diol, the phthalic anhydride polyester polyol, and the polyether polyol is (6-8):(1-3):1; Wherein, the number-average molecular weight of the polycaprolactone diol is 2000-3000; the phthalic anhydride polyester polyol is at least one of phthalic anhydride-hexanediol polyester polyol or phthalic anhydride-neopentyl glycol polyester polyol; the polyether polyol is polyethylene glycol, and the number-average molecular weight of the polyethylene glycol is 600-800.

[0009] By adopting the above technical solution, the resulting waterborne polyurethane not only possesses high gloss and good surface hardness, but also effectively reduces surface tackiness, which is beneficial for improving the appearance quality and user experience of subsequent waterborne polyurethane nail polish. Furthermore, by further defining the specific components of polycaprolactone diol, phthalic anhydride polyester polyol, and polyether polyol, not only is it beneficial to ensure the processing performance of the waterborne polyurethane, preventing it from becoming too viscous and difficult to process, but it also effectively balances the relationship between the flexibility and rigidity of the subsequent waterborne polyurethane coating.

[0010] Optionally, the phthalic anhydride polyester polyol is a composition of phthalic anhydride-hexanediol polyester polyol and phthalic anhydride-neopentyl glycol polyester polyol, and the mass ratio of phthalic anhydride-hexanediol polyester polyol to phthalic anhydride-neopentyl glycol polyester polyol is (4-5):1.

[0011] By adopting the above technical solution, it is beneficial to maintain a high gloss in the coating film formed by water-based polyurethane, and to ensure good performance in terms of surface drying time and surface hardness. This is beneficial to make the nail polish produced subsequently both durable and have excellent surface gloss and feel.

[0012] Optionally, the mass ratio of the amino-type furanyl monomer to the amino-type maleimide monomer is 1:(1.2-1.5).

[0013] By adopting the above technical solutions, a denser cross-linked network structure can be formed during the film-forming process. This not only helps to reduce the microscopic unevenness of the film surface, thereby significantly improving the gloss of nail polish, but also helps to shorten the surface drying time of water-based polyurethane and improve the problem of surface tackiness, making the coating film more durable and glossy.

[0014] Optionally, the amino-type furanyl monomer is a composition of 2,5-bis(aminomethyl)furan and [5-(3-aminophenyl)furan-2-yl]methanol, and the mass ratio of 2,5-bis(aminomethyl)furan to [5-(3-aminophenyl)furan-2-yl]methanol is (1-2):1; The amino-based maleimide monomer is N-(2-aminoethyl)maleimide.

[0015] By adopting the above technical solution, when the amino-type furanyl monomer is composed of 2,5-bis(aminomethyl)furan and [5-(3-aminophenyl)furan-2-yl]methanol, it is beneficial to further improve the gloss and surface hardness of nail polish. The N-(2-aminoethyl)maleimide used can react with the chain extender through the amino group, which can not only stably graft onto the polyurethane molecular chain, but also ensure that the DA reaction is not affected, which is beneficial to ensure the stable performance of the modification effect of the subsequent functional monomers.

[0016] Optionally, the polyisocyanate further includes HDI trimer, and the mass ratio of IPDI to HDI trimer is (8-9.5):(0.5-2).

[0017] By adopting the above technical solution, using IPDI as the main polyisocyanate helps to ensure the yellowing resistance of the subsequent film formation. The addition of a small amount of HDI trimer as an aid can provide multifunctional crosslinking sites for the waterborne polyurethane system, which is beneficial to improve the crosslinking density of the coating film. At the same time, in conjunction with the rigid segments of phthalic anhydride polyester polyol, it can further promote the tight stacking of molecular chains of waterborne polyurethane after film formation, which is beneficial to further optimize the pencil hardness and water resistance of the coating film.

[0018] Optionally, the hydrophilic agent is one of 2,2-dimethylolpropionic acid or 2,2-dimethylolbutyric acid.

[0019] By adopting the above technical solution, both are small molecule carboxylic acid hydrophilic agents that can achieve chemical bonding with polyurethane molecular chains through hydroxyl groups, which is beneficial to ensure the stability of emulsion preparation. At the same time, the hydrophilicity of both is not very strong, which is beneficial to balancing the relationship between the stability, water resistance, and anti-tack properties of waterborne polyurethane.

[0020] Optionally, the chain extender is one of ethylenediamine, castor oil, or a silane coupling agent.

[0021] By employing the above technical solutions, all three methods can effectively extend the polyurethane molecular chains and achieve the technical effect of preventing surface stickiness over a long period of time. Furthermore, when castor oil is used as the post-chain extender, the resulting waterborne polyurethane coating exhibits the best gloss.

[0022] Secondly, the method for preparing water-based polyurethane nail polish provided in this application adopts the following technical solution: A method for preparing water-based polyurethane nail polish includes the following steps: S1. Add the mixed polyols to the reactor in advance, dehydrate them at high temperature, introduce inert gas and start stirring in an inert atmosphere, add polyisocyanate, heat to 83-92℃ and continue stirring for 2-3 hours, and add amino-type furanyl monomer within 30 minutes before the reaction. After the reaction is completed, polyurethane prepolymer is obtained. S2. Add a hydrophilic agent and an auxiliary solvent to the polyurethane prepolymer obtained in S1, maintain the temperature and continue stirring for 1-2 hours, then lower the temperature to 35-50°C, add a neutralizing agent to neutralize the reaction, then add deionized water, homogenize at high speed 2-3 times, after which slowly add a chain extender and an amino-type maleimide monomer, stir at high speed, after which reduce the stirring speed and vacuum distill to remove the auxiliary solvent in the system, and obtain the waterborne polyurethane.

[0023] By employing the above-mentioned technical solution, adding an amino-type furanyl monomer 30 minutes before the reaction allows for a full reaction between the amino group and the isocyanate group of the prepolymer, achieving stable grafting of the furanyl group onto the polyurethane prepolymer molecular chain. Simultaneously adding a chain extender and an amino-type maleimide monomer ensures stable chain extension of the polyurethane prepolymer while introducing the amino-type maleimide monomer through grafting with the chain extender. This provides additional active sites for in-situ crosslinking during the subsequent nail polish film-forming process. Furthermore, the overall preparation process requires no special equipment, features mild reaction conditions, strong process controllability, and good repeatability, making it suitable for large-scale industrial production.

[0024] Optionally, the auxiliary solvent is acetone, and the amount of the auxiliary solvent added is equal to the total mass of the polyurethane prepolymer.

[0025] In summary, the technical solution of this application has at least one of the following beneficial effects: 1. By using specific mixed polyols and functional monomers in a specific ratio, the gloss and surface feel of waterborne polyurethane film can be effectively improved, thereby enhancing the appearance quality and product value of waterborne polyurethane nail polish.

[0026] 2. By introducing amino-type furanyl monomers and amino-type maleimide monomers as functional monomers, not only can the crosslinking density of waterborne polyurethane be further improved by synergistic mixing of polyols and polyisocyanates, but the surface properties of the coating film can also be improved, making the coating smoother, reducing the problem of re-tack, and making it more durable and glossy.

[0027] 3. By using castor oil as a chain extender, it can not only stably graft the introduced amino-maleimide monomer and attach the amino-maleimide monomer to the waterborne polyurethane backbone, but also further improve the gloss of the coating film through the double bonds. Detailed Implementation

[0028] The present application will be further described in detail below with reference to embodiments, comparative examples and application examples.

[0029] Polycaprolactone diol was specifically purchased from Jinan Yuno Chemical Co., Ltd., with the specific grades being PCL 2000 and PCL 3000. The number average molecular weight of PCL 2000 is 2000, and that of PCL 3000 is 3000.

[0030] The phthalic anhydride polyester polyols were specifically purchased from Nanjing Shouqianshou Chemical Technology Co., Ltd., with the specific grades PA-56H and PA-110N. PA-56H is a phthalic anhydride-hexanediol polyester polyol with a number average molecular weight of 1000 and a viscosity of 30000-5000 cP. PA-110N is a phthalic anhydride-neopentyl glycol polyester polyol with a number average molecular weight of 2000 and a viscosity of >10000 cP.

[0031] The polyethylene glycol was specifically purchased from Haian Petrochemical, with the specific grades being PEG-600 and PEG-800. Example

[0032]

Example 1

[0033] In this embodiment, the mixed polyol is specifically a composition of polycaprolactone diol, phthalic anhydride-hexanediol polyester polyol, and polyethylene glycol, wherein the polycaprolactone diol is grade PCL-2000, and the polyethylene glycol is grade PEG-600. Specifically, the mass ratio of polycaprolactone diol, phthalic anhydride-hexanediol polyester polyol, and polyethylene glycol is 6:3:1, that is, it includes 18g of polycaprolactone diol, 9g of phthalic anhydride-hexanediol polyester polyol, and 3g of polyethylene glycol.

[0034] In this embodiment, the polyisocyanate comprises 9.6 g IPDI and 2.4 g HDI trimer.

[0035] In this embodiment, the functional monomers include an amino-type furanyl monomer and an amino-type maleimide monomer, wherein the mass ratio of the amino-type furanyl monomer to the amino-type maleimide monomer is 1:1. Specifically, the amino-type furanyl monomer is 2,5-bis(aminomethyl)furan, and the amino-type maleimide monomer is N-(2-aminoethyl)maleimide. That is, the functional monomers include 0.3g of 2,5-bis(aminomethyl)furan and 0.36g of N-(2-aminoethyl)maleimide.

[0036] In this embodiment, the hydrophilic agent is 2,2-dimethylolpropionic acid, and the chain extender is ethylenediamine.

[0037] A method for preparing water-based polyurethane nail polish includes the following steps: S1. Add the mixed polyols to the reactor in advance, dehydrate them at high temperature, introduce nitrogen gas and start stirring under nitrogen atmosphere, add polyisocyanate, heat to 83°C and stir continuously for 2 hours, and add amino-type furanyl monomer within 30 minutes before the reaction. After the reaction is completed, polyurethane prepolymer is obtained. S2. Add a hydrophilic agent and acetone to the polyurethane prepolymer obtained in S1, wherein the amount of acetone added is equal to the total mass of the polyurethane prepolymer. Maintain the temperature and continue stirring for 2 hours. Then lower the temperature to 40°C, add triethylamine to neutralize the reaction, and then add deionized water. Homogenize at a high speed of 10,000 rpm three times. After homogenization, add a chain extender and an amino-type maleimide monomer. Stir at a high speed of 500 rpm to react. After the reaction, reduce the stirring speed to 300 rpm and vacuum distill to remove acetone from the system to obtain the waterborne polyurethane.

[0038]

Example 2

[0039] In this embodiment, the mixed polyol is specifically a composition of polycaprolactone diol, phthalic anhydride-hexanediol polyester polyol, phthalic anhydride-neopentyl glycol polyester polyol, and polyethylene glycol, wherein the polycaprolactone diol is grade PCL-3000 and the polyethylene glycol is grade PEG-800. Specifically, the mass ratio of polycaprolactone diol, phthalic anhydride-neopentyl glycol polyester polyol, and polyethylene glycol is 8:0.8:0.2:1, which includes 28g of polycaprolactone diol, 2.8g of phthalic anhydride-hexanediol polyester polyol, 0.7g of phthalic anhydride-neopentyl glycol polyester polyol, and 3.5g of polyethylene glycol.

[0040] In this embodiment, the polyisocyanate specifically includes 15.2g IPDI and 0.8g HDI trimer.

[0041] In this embodiment, the functional monomers include an amino-type furanyl monomer and an amino-type maleimide monomer, wherein the amino-type furanyl monomer is 2,5-bis(aminomethyl)furan, and the amino-type maleimide monomer is N-(2-aminoethyl)maleimide, that is, the functional monomers include 0.3g of 2,5-bis(aminomethyl)furan and 0.45g of N-(2-aminoethyl)maleimide.

[0042] In this embodiment, the hydrophilic agent is 2,2-dihydroxymethylbutyric acid, and the chain extender is silane coupling agent KH602.

[0043] A method for preparing water-based polyurethane nail polish includes the following steps: S1. Add the mixed polyols to the reactor in advance, dehydrate them at high temperature, introduce nitrogen gas and start stirring under nitrogen atmosphere, add polyisocyanate, heat to 92°C and stir continuously for 2 hours, and add amino-type furanyl monomer within 30 minutes before the reaction. After the reaction is completed, polyurethane prepolymer is obtained. S2. Add a hydrophilic agent and acetone to the polyurethane prepolymer obtained in S1, wherein the amount of acetone added is equal to the total mass of the polyurethane prepolymer. Maintain the temperature and continue stirring for 2 hours. Then lower the temperature to 45°C, add triethylamine to neutralize the reaction, and then add deionized water. Homogenize at a high speed of 12,000 rpm three times. After homogenization, add a chain extender and an amino-type maleimide monomer. Stir at a high speed of 500 rpm to react. After the reaction, reduce the stirring speed to 300 rpm and vacuum distill to remove acetone from the system to obtain the waterborne polyurethane.

[0044]

Example 3

[0045] In this embodiment, the mixed polyol is specifically a composition of polycaprolactone diol, phthalic anhydride-neopentyl glycol polyester polyol, and polyethylene glycol, wherein the phthalic anhydride-neopentyl glycol polyester polyol is grade PA-110N. Specifically, it includes 18g of polycaprolactone diol, 9g of phthalic anhydride-neopentyl glycol polyester polyol, and 3g of polyethylene glycol.

[0046]

Example 4

[0047] In this embodiment, the mixed polyol is specifically a composition of polycaprolactone diol, phthalic anhydride-hexanediol polyester polyol, phthalic anhydride-neopentyl glycol polyester polyol, and polyethylene glycol. Specifically, it includes 18g of polycaprolactone diol, 7.5g of phthalic anhydride-hexanediol polyester polyol, 1.5g of phthalic anhydride-neopentyl glycol polyester polyol, and 3g of polyethylene glycol.

[0048]

Example 5

[0049] In this embodiment, the mixed polyol is specifically a composition of polycaprolactone diol, phthalic anhydride-hexanediol polyester polyol, phthalic anhydride-neopentyl glycol polyester polyol, and polyethylene glycol. Specifically, it includes 18g of polycaprolactone diol, 6g of phthalic anhydride-hexanediol polyester polyol, 3g of phthalic anhydride-neopentyl glycol polyester polyol, and 3g of polyethylene glycol.

[0050]

Example 6

[0051] In this embodiment, the amino-type furanyl monomer is a composition of 2,5-bis(aminomethyl)furan and [5-(3-aminophenyl)furan-2-yl]methanol in a 1:1 ratio. That is, the functional monomer comprises 0.15g of 2,5-bis(aminomethyl)furan, 0.15g of [5-(3-aminophenyl)furan-2-yl]methanol, and 0.3g of N-(2-aminoethyl)maleimide.

[0052]

Example 7

[0053] In this embodiment, the amino-type furanyl monomer is a composition of 2,5-bis(aminomethyl)furan and [5-(3-aminophenyl)furan-2-yl]methanol in a 2:1 ratio. That is, the functional monomer comprises 0.2g of 2,5-bis(aminomethyl)furan, 0.1g of [5-(3-aminophenyl)furan-2-yl]methanol, and 0.3g of N-(2-aminoethyl)maleimide.

[0054]

Example 8

[0055] In this embodiment, the chain extender is castor oil.

[0056]

Example 9

[0057] In this embodiment, the chain extender is the silane coupling agent KH604. Comparative Example

[0058] Comparative Example 1 A water-based polyurethane nail polish differs from [Example 1] in that it uses a different mixed polyol.

[0059] In this comparative example, polycaprolactone diol was used to replace phthalic anhydride polyester polyol in equal amounts, i.e., the mixed polyols included 27g of polycaprolactone diol and 3g of polyethylene glycol.

[0060] Comparative Example 2 A water-based polyurethane nail polish differs from [Example 1] in that it does not contain functional monomers. Performance testing

[0061] Preparation of nail polish samples to be tested: The nail polish samples to be tested were prepared according to the formulation in Table 1. The waterborne polyurethane resin used in test examples 1-9 was prepared from the corresponding examples 1-9, and the waterborne polyurethane used in test examples 10-11 was prepared from the corresponding examples 1-2. The overall viscosity of the nail polish was controlled to be 1500 mpa·s / 25℃ by using deionized water.

[0062] Table 1. Nail Polish Formulas to be Tested

[0063] 1. Gloss: The nail polish sample to be tested was dried on a black polyamide plastic plate with a thickness of 100μm. The test was carried out in accordance with GB / T 9754-2007 Determination of specular gloss of paint film without metallic pigments at 20°, 60° and 85°. The gloss meter used was used to measure the gloss of the film at 60°.

[0064] 2. Surface drying time test: Refer to section 6.4 of GB / T 2287-2011 Nail Polish for testing. Under the conditions of room temperature (20±5)℃ and relative humidity ≤80%, use the finger touch method. That is, clean the sample with ethyl acetate, wait for it to dry, and then use a brush to apply the nail polish sample to be tested onto the sample in one go. Touch the coating with your finger every 30 seconds for 2 minutes until there is no adhesion when you touch the coating with your finger, and record the current time.

[0065] 3. Pencil Hardness: The nail polish sample to be tested was coated with a film of 100 μm thickness on a black polyamide plastic plate. After drying, the hardness of the film was tested according to "GB / T 6739-2006 Determination of Hardness of Paints and Varnishes by Pencil Method" and the test results of each sample were recorded. The pencil load was 750g.

[0066] 4. Water resistance test: Apply the nail polish sample to be tested to a black polyamide plastic plate with a thickness of 100μm. After drying, place it in a room temperature water bath and soak for 1 hour. Observe whether the edges are peeling or flaking. If there is no obvious peeling, flaking, whitening or loss of gloss, it is recorded as qualified; otherwise, it is unqualified.

[0067] 5. Surface tack test: Apply the nail polish sample to be tested to a black polyamide plastic plate with a thickness of 100μm. After drying, let it stand at room temperature for 72 hours. Observe and touch the surface with your finger to see if there is any tackiness. If there is no obvious tackiness and the surface is smooth, it is recorded as qualified; otherwise, it is unqualified.

[0068] Table 2 Performance test data of the nail polish samples to be tested

[0069] Combining Test Examples 1 and 10-11 with the data in Table 2, it can be seen that, under the premise that other raw materials for preparing nail polish are the same, the waterborne polyurethane prepared in Example 1 exhibits the performance of Comparative Examples 1 and 2 in terms of gloss, surface drying time, pencil hardness and water resistance.

[0070] Specifically, as shown in Test Examples 1 and 10 and their data, adding a small amount of phthalic anhydride polyester polyol to the mixed polyol can effectively improve the gloss, hardness, and water resistance of the cured waterborne polyurethane. This is likely because the phthalic anhydride polyester polyol introduces aromatic benzene rings and rigid polyester segments. The aromatic benzene rings have high refractive index and hydrophobicity, which not only significantly improves the overall refractive index of the waterborne polyurethane, which is mainly composed of aliphatic segments, but also maximizes the specular reflection ability of light in conjunction with the aromatic heterocycles of the functional monomers, thus improving gloss. Furthermore, it can balance the hydrophilic properties in the system and work with the rigid polyester segments to block water molecule penetration, thereby improving water resistance. As the molecular backbone of the waterborne polyurethane, the rigid polyester segments can reduce molecular chain entanglement. At the same time, in conjunction with the crosslinking network containing HDI trimers, it is beneficial to promote the tight packing of molecular chains during curing and film formation, and improve the hardness of the coating film.

[0071] Furthermore, as shown in Test Examples 1 and 11 and their data, introducing a small amount of functional monomers composed of amino-furan-based monomers and amino-maleimide-based monomers can not only effectively shorten the surface drying time of nail polish, thus improving the film-forming and curing efficiency of waterborne polyurethane, but also improve the surface tackiness of nail polish. This may be because the introduced functional monomers all contain strongly hydrophobic aromatic heterocycles. Aromatic heterocycles not only help reduce the hydrophilicity of the coating surface and accelerate water evaporation, but also, due to the structural characteristics of the furan group and maleimide group in the functional monomers, they can slowly undergo a DA cycloaddition reaction at room temperature. This reaction can accelerate the curing of the coating film and shorten the surface drying time by adding crosslinking sites in situ, and can also generate a more hydrophobic heterocyclic structure, making the coating molecules more densely packed, reducing the exposure of surface hydrophilic groups, and thus further improving its surface hardness, water resistance, and improving the surface tackiness of the coating film.

[0072] Combining Test Example 1 and Test Examples 3-5 with the data in Table 2, it can be seen that when phthalic anhydride polyester polyol is combined with phthalic anhydride-hexanediol polyester polyol and phthalic anhydride-neopentyl glycol polyester polyol in a certain proportion, the resulting waterborne polyurethane has a better overall film-forming effect after being prepared into nail polish. Not only does the gloss of the nail polish remain at a high level, but the surface drying time is also moderate, neither too long to cause inconvenience in use nor too short to affect the film-forming quality. In addition, the pencil hardness is also moderate, which ensures the durability of the nail polish without affecting the feel of the coating due to excessive hardness.

[0073] Combining Test Examples 4 and 6-7 with the data in Table 2, it can be seen that when the amino-type furanyl monomer is a combination of 2,5-di(aminomethyl)furan and [5-(3-aminophenyl)furan-2-yl]methanol in a certain proportion, the resulting waterborne polyurethane exhibits better overall film-forming performance after being prepared into nail polish compared to using only 2,5-di(aminomethyl)furan. Since [5-(3-aminophenyl)furan-2-yl]methanol also introduces some aromatic benzene rings and has higher molecular chain rigidity, it can also appropriately improve the gloss and surface hardness of the nail polish.

[0074] Based on test examples 7-9 and the data in Table 2, it can be seen that when castor oil is used as the chain extender, the resulting waterborne polyurethane coating exhibits the highest gloss when used as nail polish. This is likely because natural castor oil contains a large number of unsaturated double bonds, and these double bonds have a high refractive index, resulting in higher gloss after film formation.

[0075] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this specific embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A water-based polyurethane nail polish, characterized in that, Based on the total mixed mass of waterborne polyurethane, the following percentages of raw materials are included: Mixed polyols: 30-35%; Polyisocyanates: 12-16%; Functional monomers: 0.66-0.75%; Hydrophilic agent: 1-1.6%; Chain extender: 1.2-2%; The remainder is deionized water; The mixed polyol is a composition of polycaprolactone diol, phthalic anhydride polyester polyol and polyether polyol, the polyisocyanate includes IPDI, and the functional monomer includes amino-type furanyl monomer and amino-type maleimide monomer.

2. The waterborne polyurethane nail polish according to claim 1, characterized in that: In the mixed polyols, the mass ratio of the polycaprolactone diol, the phthalic anhydride polyester polyol, and the polyether polyol is (6-8):(1-3):1; Wherein, the number-average molecular weight of the polycaprolactone diol is 2000-3000; the phthalic anhydride polyester polyol is at least one of phthalic anhydride-hexanediol polyester polyol or phthalic anhydride-neopentyl glycol polyester polyol; the polyether polyol is polyethylene glycol, and the number-average molecular weight of the polyethylene glycol is 600-800.

3. The waterborne polyurethane nail polish according to claim 2, characterized in that: The phthalic anhydride polyester polyol is a composition of phthalic anhydride-hexanediol polyester polyol and phthalic anhydride-neopentyl glycol polyester polyol, and the mass ratio of phthalic anhydride-hexanediol polyester polyol to phthalic anhydride-neopentyl glycol polyester polyol is (4-5):

1.

4. The waterborne polyurethane nail polish according to claim 1, characterized in that: The mass ratio of the amino-type furanyl monomer to the amino-type maleimide monomer is 1:(1.2-1.5).

5. The waterborne polyurethane nail polish according to claim 4, characterized in that: The amino-type furanyl monomer is a composition of 2,5-bis(aminomethyl)furan and [5-(3-aminophenyl)furan-2-yl]methanol, and the mass ratio of 2,5-bis(aminomethyl)furan to [5-(3-aminophenyl)furan-2-yl]methanol is (1-2):1; The amino-based maleimide monomer is N-(2-aminoethyl)maleimide.

6. The waterborne polyurethane nail polish according to claim 1, characterized in that: The polyisocyanate further includes HDI trimer, and the mass ratio of IPDI to HDI trimer is (8-9.5):(0.5-2).

7. The waterborne polyurethane nail polish according to claim 1, characterized in that: The hydrophilic agent is one of 2,2-dimethylolpropionic acid or 2,2-dimethylolbutyric acid.

8. The waterborne polyurethane nail polish according to claim 1, characterized in that: The chain extender is one of ethylenediamine, castor oil, or silane coupling agent.

9. A method for preparing waterborne polyurethane for nail polish, used to prepare waterborne polyurethane for nail polish as described in any one of claims 1-8, characterized in that, Includes the following steps: S1. Add the mixed polyols to the reactor in advance, dehydrate them at high temperature, introduce inert gas and start stirring in an inert atmosphere, add polyisocyanate, heat to 83-92℃ and continue stirring for 2-3 hours, and add amino-type furanyl monomer within 30 minutes before the reaction. After the reaction is completed, polyurethane prepolymer is obtained. S2. Add a hydrophilic agent and an auxiliary solvent to the polyurethane prepolymer obtained in S1, maintain the temperature and continue stirring for 1-2 hours, then lower the temperature to 35-50°C, add a neutralizing agent to neutralize the reaction, then add deionized water, homogenize at high speed 2-3 times, after which slowly add a chain extender and an amino-type maleimide monomer, stir at high speed, after which reduce the stirring speed and vacuum distill to remove the auxiliary solvent in the system, and obtain the waterborne polyurethane.

10. The method for preparing a waterborne polyurethane nail polish according to claim 9, characterized in that: The auxiliary solvent is acetone, and the amount of the auxiliary solvent added is equal to the total mass of the polyurethane prepolymer.

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