Cyclodextrin-based water-resistant modified polyurethane film-forming agent and preparation method thereof

Abstract

The invention belongs to the technical field of cosmetics, and discloses a cyclodextrin-based water-resistant modified polyurethane film-forming agent and a preparation method thereof. The cyclodextrin-based water-resistant modified polyurethane film-forming agent comprises a hydrophilic chain segment and a hydrophobic chain segment, the hydrophilic chain segment comprises a chain segment formed by raw materials of cyclodextrin and 2, 2-dimethylolbutyric acid, and the hydrophobic chain segment comprises a chain segment formed by a raw material of organosilicon. Compared with the prior art, the cyclodextrin-based water-resistant modified polyurethane film-forming agent disclosed by the invention has good film-forming property, water resistance, dispersity, softness and adhesive force, can also be used as a film-forming material of cosmetic products, and enhances the waterproof, sweat-resistant and lasting characteristics of cosmetics.

Description

Technical Field

[0001] The invention relates to the technical field of cosmetics, and in particular to a cyclodextrin-based water-resistant modified polyurethane film-forming agent and a preparation method thereof. Background Art

[0002] Cosmetic film formers refer to ingredients used in cosmetic formulas that can form a thin film on the skin surface to protect, fix and improve the effects of cosmetics. As people's requirements for the quality and durability of cosmetics continue to increase, the demand for cosmetic film formers is also gradually increasing. Common cosmetic film formers are mainly divided into two categories: one is oily film formers, such as trimethylsiloxane silicone triesters, acrylic resin and dimethylsiloxane copolymers, etc.; the other is water-based film formers, such as polyvinyl pyrrolidone, polyvinyl alcohol, polyurethane, etc. However, the films of these film formers on the market are relatively hard, and they feel tight when used. The skin feel of soft films is relatively sticky, the film forming speed is slow, and the setting effect cannot be achieved. Therefore, in cosmetic formulas, the addition of film formers is intended to enhance the appearance, texture and durability of cosmetics, and may also have the effect of protecting the skin, making it one of the indispensable and important components in cosmetic formulas.

[0003] Polyurethane (PU) is a commonly used film-forming agent in cosmetics due to its film-forming, good elasticity, high gloss, good toughness, and non-sticky feel. It is a class of organic polymer materials, which are connected by organic units of carbamate (R-NH-COO-R) synthesized by the reaction of polyisocyanate (OCN-R-NCO) and polyol (HO-R-OH). The performance of polyurethane (PU) is mainly determined by the structure of its soft segment and hard segment. Due to the flexibility in the selection of hard segment and soft segment materials, a variety of different chemical structures and microphase separation can be regulated, so that polyurethane has excellent elastic range, tensile strength, friction performance, film-forming, low temperature resistance and other advantages. Traditional PU coatings contain a large amount of volatile organic compounds (VOCs) in their composition. The release of these organic compounds may cause environmental pollution and pose a potential hazard to human health. Waterborne polyurethane (WPU) technology uses water as the main dispersion medium, which greatly reduces the emission of volatile organic compounds (VOCs) and has the advantages of safety, reliability, pollution-free, excellent mechanical properties, good compatibility, and easy modification. However, in the process of preparing WPU, hydrophilic groups are introduced, resulting in poor water resistance, heat resistance and solvent resistance, making it difficult to meet people's requirements for material functional diversity.

[0004] Silicone is a compound with a special molecular chain structure. The main chain is an alternating -Si-O-Si- bond, and the side chain has an organic group. This structure gives the silicone compound the dual characteristics of inorganic and organic materials. Due to the high Si-O bond energy and low internal rotation energy barrier, the silicone compound has good flexibility, low temperature resistance and water resistance. The introduction of silicone materials into WPU can improve its water resistance and thermal stability, making up for the shortcomings of polyurethane performance.

[0005] Cyclodextrin (CD) is a natural cyclic oligosaccharide obtained by the degradation of starch by cyclodextrin glucosyltransferase. It is composed of multiple glucose residues connected by α-1,4-glycosidic bonds. The number of glucose residues is generally 6, 7, and 8, which are called α-, β-, and γ-cyclodextrin, respectively. Each glucose residue in each cyclodextrin molecule has 1 primary hydroxyl group and 2 secondary hydroxyl groups, that is, each β-cyclodextrin molecule has 7 primary hydroxyl groups and 14 secondary hydroxyl groups. Since the hydroxyl groups are concentrated on the outer edge of the molecule, the outer wall of the cyclodextrin molecule has strong hydrophilicity. The inner cavity of cyclodextrin is composed of hydrogen atoms at C-3 and C-5 and oxygen atoms at C-4. Since the hydrogen atoms at C-3 and C-5 have a shielding effect on the glycoside oxygen atom at C-4, cyclodextrin has strong hydrophobicity. Due to its unique "hydrophobic inside and hydrophilic outside" property, cyclodextrin can interact with some small molecules of appropriate size and polarity to form host-guest inclusion complexes, thereby improving the solubility of the guest molecules and enhancing the stability of the guest molecules. Summary of the invention

[0006] The purpose of the present invention is to provide a cyclodextrin-based water-resistant modified polyurethane film-forming agent and a preparation method thereof in view of the above-mentioned deficiencies in the prior art, which has good film-forming properties, water resistance, dispersibility, softness and good adhesion, and can also be used as a film-forming material for makeup products, thereby enhancing the waterproof, sweat-proof and long-lasting properties of cosmetics.

[0007] The technical solution adopted by the present invention to achieve the above-mentioned purpose is: In a first aspect, the present invention provides a cyclodextrin-based water-resistant modified polyurethane film-forming agent, which includes a hydrophilic segment and a hydrophobic segment, wherein the hydrophilic segment includes a molecular segment formed by raw material cyclodextrin and 2,2-dihydroxymethylbutyric acid, and the hydrophobic segment includes a molecular segment formed by raw material silicone.

[0008] Preferably, the mass proportion of cyclodextrin in the hydrophilic segment in the cyclodextrin-based water-resistant modified polyurethane film-forming agent is 0.5-0.6wt%; the mass proportion of silicone in the hydrophobic segment in the cyclodextrin-based water-resistant modified polyurethane film-forming agent is 0.5-1.4wt%.

[0009] Preferably, the cyclodextrin is β-cyclodextrin.

[0010] Preferably, the organosilicon is γ-aminopropyltriethoxysilane (KH550).

[0011] In a second aspect, a method for preparing the above-mentioned cyclodextrin-based water-resistant modified polyurethane film-forming agent of the present invention comprises the following steps: S1. Mix cyclodextrin, solvent, 2,2-dihydroxymethylbutyric acid, polycaprolactone diol, isophorone diisocyanate, and dibutyltin dilaurate, and heat under condensation reflux with stirring for a certain time at a certain temperature to obtain solution A; S2. The chain extender 1,4-butanediol is added to solution A, and the mixture is condensed, refluxed, stirred and heated at a certain temperature for a certain period of time to obtain solution B; S3. triethylamine and organosilicon are added to solution B, and the mixture is condensed, refluxed, stirred and heated at a certain temperature for a certain period of time to obtain solution C; S4. Add pure water to solution C, stir and mix to fully dissolve, and obtain solution D, that is, a cyclodextrin-based water-resistant modified polyurethane film-forming agent.

[0012] Preferably, the method further comprises step S5 of purifying solution D, wherein the purification is dialysis purification.

[0013] Preferably, the amount of silicone used in step S3 is 0-0.12 g.

[0014] Preferably, in step S1, the mass volume ratio of cyclodextrin, solvent, 2,2-dihydroxymethylbutyric acid, polycaprolactone diol, isophorone diisocyanate and dibutyltin dilaurate is 0.02-0.1g: 3-10mL: 0.5-1g: 3-4g: 3-5g: 0.05-0.2g; in step S1, the mixture is condensed, refluxed, stirred and heated at 70-80°C under a nitrogen atmosphere for 1-2h.

[0015] Preferably, the amount of 1,4-butanediol added in step S2 is 0.48 g; and in step S2, the mixture is condensed, refluxed, stirred and heated at 70-80° C. under a nitrogen atmosphere for 1.5-2 h.

[0016] Preferably, the amount of triethylamine added in step S3 is 0.33 g; in step S3, the mixture is heated with condensation, reflux, stirring and heating at 40-50° C. under nitrogen atmosphere for 1.5-2 h.

[0017] Waterborne polyurethane (WPU) or polyurethane emulsion is formed by the exothermic reaction between diisocyanate and molecules containing two or more hydroxyl groups. Repeated carbamate groups are generated during the prepolymer reaction. Usually, chain extenders containing hydrophilic groups, chain extenders of diols or diamines, catalysts or other additives should be added to form WPU prepolymers. Then, water is added to the prepolymer system to extend the chain, emulsify and disperse the prepolymer to obtain WPU dispersion. However, the addition of hydrophilic groups will lead to poor hydrophobicity and water resistance of WPU films, so silicone can be used to modify them. The structure of silane coupling agents is generally expressed as X3Si(CH2)nY, where n=0-3, X represents a hydrolyzable group on Si, generally an alkoxy group; and Y is an organic functional group that reacts with a given resin. The hydrophobic modification of WPU by silane coupling agent is connected to the WPU macromolecular chain in the form of covalent bonds through chemical reactions. The active organic functional group Y (such as amino, epoxy) at one end of the silane coupling agent reacts with the isocyanate of WPU, and the alkoxy group (X group) at the other end is hydrolyzed into silanol at room temperature. The silanol groups then form a three-dimensional -Si-O-Si- cross-linked structure through dehydration condensation. Since the Si-O-Si bond has good hydrophobicity, it can give WPU good water resistance. γ-Aminopropyltriethoxysilane (KH550) is an amino silane coupling agent with rich nitrogen-containing and oxygen-containing groups. The aminopropyl group of KH550 reacts with the hydroxyl group in the polyurethane prepolymer to form a covalent bond, and KH550 is grafted onto the polyurethane molecule. This chemical bonding can significantly improve the interfacial bonding between polyurethane and inorganic materials and enhance the overall performance of the material. Each glucose residue in the cyclodextrin molecule has 1 primary hydroxyl group and 2 secondary hydroxyl groups, that is, each β-cyclodextrin molecule has 7 primary hydroxyl groups and 14 secondary hydroxyl groups, which can react with isocyanate as a hydroxyl component, and the cyclodextrin molecular structure forms a part of the polyurethane body. The special cavity structure of cyclodextrin can give polyurethane materials more application functions, such as selective adsorption inclusion, inclusion of functional additives or materials, formation of cavity network structure, increase of molecular cross-linking, etc. Therefore, the present invention introduces cyclodextrin into waterborne polyurethane. Due to the special cavity structure, some active substances that are difficult to dissolve in water can be loaded, and the characteristics such as high compatibility with active ingredients can be improved, and the volatilization rate can be reduced, so as to achieve the purpose of sustained release and improve the added value of the film-forming agent.

[0018] The cyclodextrin-based water-resistant modified polyurethane film-forming agent of the present invention introduces silicone and cyclodextrin into waterborne polyurethane through chemical reaction to prepare a composite material. First, cyclodextrin is used as a hydroxyl group to react with isocyanate to obtain an isocyanate (NCO-) terminated prepolymer, and an appropriate amount of chain extender is added to expand the molecular weight of the polymer. Then, by introducing silicone, hydrolysis and condensation, a Si-O-Si- three-dimensional cross-linked structure is formed, giving WPU good water resistance. Specifically, cyclodextrin-based water-resistant modified polyurethane film-forming agent (CD-WPU-Si) is synthesized using raw materials such as β-cyclodextrin (β-CD), polycaprolactone diol (PCL-2000), isophorone diisocyanate (IPDI), 2,2-dihydroxymethylbutyric acid (DMBA), silicone, etc. The material has good film-forming property, water resistance, dispersibility, softness and good adhesion, and can be used as a film-forming material for makeup products, enhancing the waterproof, sweat-proof and long-lasting properties of cosmetics.

[0019] The present invention selects water-insoluble resveratrol as an active ingredient, mixes resveratrol with the prepared film-forming material, and prepares an inclusion compound. Through testing, it is proved that the material has good loading capacity, and resveratrol can be released by a suitable method to achieve the purpose of sustained and controlled release, so that the makeup product has skin care effect.

[0020] Compared with the prior art, the present invention has the following beneficial effects: 1. The cyclodextrin-based water-resistant modified polyurethane film-forming agent of the present invention is prepared by reacting β-cyclodextrin (β-CD) and 2,2-dihydroxymethylbutyric acid (DMBA) as hydrophilic segments with polycaprolactone diol (PCL-2000), isophorone diisocyanate (IPDI), silicone and other raw materials. The polyurethane is modified by utilizing the hydrophobicity of silicone, so that the cyclodextrin-based water-resistant modified polyurethane film-forming agent has good water resistance, thereby improving the waterproof and sweat-proof capabilities of makeup products.

[0021] 2. Due to its unique cavity structure, the cyclodextrin of the present invention can interact with some small molecules of suitable size and polarity to form a host-guest inclusion complex. Introducing cyclodextrin as a hydroxyl component into polyurethane can make water-based polyurethane include some insoluble active ingredients, thereby increasing the added value of water-based polyurethane. By introducing β-cyclodextrin (β-CD), the prepared cyclodextrin-based water-resistant modified polyurethane film-forming agent has the ability to load oil-soluble active substances, increases the compatibility and stability of active substances in water systems, and reduces its volatility and burst release, thereby achieving the purpose of sustained and controlled release, and making the makeup product have skin care effects.

[0022] 3. The present invention mainly uses water as a solvent, and the synthesis scheme is green and environmentally friendly, which is conducive to industrial production. Based on the degradability of β-cyclodextrin (β-CD), the cyclodextrin-based water-resistant modified polyurethane film-forming agent obtained by the present invention is environmentally friendly.

[0023] 4. The present invention selects water-insoluble resveratrol as an active ingredient, mixes resveratrol with the prepared cyclodextrin-based water-resistant modified polyurethane film-forming agent material, and prepares an inclusion compound. Through testing, it is proved that the material has good loading capacity, and resveratrol can be released by a suitable method to achieve the purpose of sustained and controlled release, so that the makeup product has skin care effect.

[0024] The above is an overview of the technical solution of the invention. The present invention will be further described below in conjunction with the accompanying drawings and specific implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 FTIR infrared spectra of CD-WPU, WPU-Si, and CD-WPU-Si; Figure 2 Schematic diagram of the relationship between different KH550 content ratios and contact angles; Figure 3 Schematic diagram of adhesion test results of CD-WPU-Si-1 with different concentrations; Figure 4 The ultraviolet spectra of β-CD, CD-WPU and CD-WPU-Si encapsulated resveratrol, wherein (a) is the ultraviolet spectrum of β-CD encapsulated resveratrol, (b) is the ultraviolet spectrum of CD-WPU encapsulated resveratrol, and (c) is the ultraviolet spectrum of CD-WPU-Si encapsulated resveratrol; Figure 5 The UV spectra of the inclusion complex decapsulated by different acids are shown in Figure 1, wherein (a) is the UV spectra of the CD-RES inclusion complex decapsulated by different acids, and (b) is the UV spectra of the CPS-RES inclusion complex decapsulated by different acids. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the following is a detailed description in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0027] The cyclodextrin-based water-resistant modified polyurethane film-forming agent of the present invention comprises: using raw materials such as β-cyclodextrin (β-CD), polycaprolactone diol (PCL-2000), isophorone diisocyanate (IPDI), 2,2-dihydroxymethylbutyric acid (DMBA), silicone, etc., and the mass volume ratio of cyclodextrin, solvent, 2,2-dihydroxymethylbutyric acid, polycaprolactone diol, isophorone diisocyanate, and dibutyltin dilaurate is 0.02-0.1g: 3-10mL: 0.5-1g: 3-4g: 3-5g: 0.05-0.2g, synthesizing an isocyanate-terminated prepolymer under appropriate temperature conditions, condensing and reflux heating at a certain temperature (80°C, in some embodiments, it can be 70°C, 75°C) for a certain time (2h, in some embodiments, it can be 1h, 1.5h), adding 1,4-butanediol (BDO) for chain extension, and heating at a certain temperature The obtained product is condensed and refluxed at 80°C (80°C, which may be 70°C or 75°C in some embodiments) for a certain period of time (2h, which may be 1.8h or 1.5h in some embodiments), and after the molecular weight is expanded by a chain extender, triethylamine and organic silicon such as γ-aminopropyltriethoxysilane (KH550) 0-0.12g are introduced for modification, and condensed and refluxed at a certain temperature (40°C, which may be 50°C or 45°C in some embodiments) for a certain period of time (2h, which may be 1.8h or 1.5h in some embodiments), and water is added for emulsification, wherein one end of the organic silicon reacts with the isocyanate, and the alkoxy group at the other end is hydrolyzed into silanol group, and the silanol group is dehydrated and condensed to form a three-dimensional -Si-O-Si- cross-linked structure, thereby obtaining a cyclodextrin-based water-resistant modified polyurethane film-forming agent (CD-WPU-Si), and the finished product is obtained by dialysis purification and sealed and stored at room temperature. In some embodiments, the amount of each raw material used: cyclodextrin can be 0.02g, 0.04g, 0.05g, 0.06g, 0.08g, or 0.1g; the solvent can be 3mL, 5mL, 7mL, or 10mL; the 2,2-dihydroxymethylbutyric acid can be 0.5g, 0.7g, 0.9g, or 1g; the polycaprolactone diol can be 3g, 3.3g, 3.5g, 3.7g, or 4g; the isophorone diisocyanate can be 3g, 3.5g, 3.9g, 4.3g, 4.6g, or 5g; and the dibutyltin dilaurate can be 0.05g, 0.08g, 0.12g, 0.15g, 0.18g, or 0.2g.

[0028] At the same time, water-insoluble resveratrol was selected as the active ingredient, and resveratrol was mixed with the prepared cyclodextrin-based water-resistant modified polyurethane film-forming agent material to prepare an inclusion compound. Through testing, it was proved that the cyclodextrin-based water-resistant modified polyurethane film-forming agent material has good loading capacity and can release resveratrol to achieve its purpose of sustained and controlled release, so that the makeup product has skin care effect.

[0029] Example 1

[0030] This embodiment provides a cyclodextrin-based water-resistant modified polyurethane film-forming agent CD-WPU (without silicone) and a preparation method thereof, and the specific steps are as follows: 1) Disperse 0.05 g of β-cyclodextrin (β-CD) in 3 mL of solvent N,N-dimethylacetamide (DMAC), stir to fully disperse it, add 3.3 g of polycaprolactone diol (PCL-2000), 3.9 g of isophorone diisocyanate (IPDI), 0.5 g of 2,2-dihydroxymethylbutyric acid (DMBA), and 0.08 g of dibutyltin dilaurate (DBTDL), and heat under condensation reflux at 80 ° C under nitrogen atmosphere, and mechanically stir for 2 h to obtain solution A; 2) Add 0.48 g of 1,4-butanediol (BDO) to solution A, heat under condensation reflux at 80°C under nitrogen atmosphere, and mechanically stir for 2 h to obtain solution B; 3) Add 0.33 g of triethylamine (TEA) to solution B, heat under condensation reflux at 40°C under nitrogen atmosphere, and mechanically stir for 1.5 h to obtain solution C; 4) Add 20 mL of pure water to solution C and stir to fully dissolve it to obtain solution D; 5) Solution D is dialyzed and purified to finally obtain a milky white liquid E (CD-WPU), namely, a cyclodextrin-based water-resistant modified polyurethane film-forming agent CD-WPU (without silicone), which is sealed and stored at room temperature.

[0031] Example 2

[0032] This embodiment provides a cyclodextrin-based water-resistant modified polyurethane film-forming agent CD-WPU-Si and a preparation method thereof, which is basically the same as that of Example 1, except that: organic silicon γ-aminopropyl triethoxysilane (KH550) is added, and the specific steps are as follows: 3) Add 0.33 g of triethylamine (TEA) and 0.04 g of γ-aminopropyltriethoxysilane (KH550) of silicone to solution B, heat under condensation reflux at 40°C under nitrogen atmosphere, and mechanically stir for 1.5 h to obtain solution C; finally, a blue-light milky white liquid is obtained, that is, a cyclodextrin-based water-resistant modified polyurethane film-forming agent (CD-WPU-Si-1) is obtained.

[0033] Example 3

[0034] This embodiment provides a cyclodextrin-based water-resistant modified polyurethane film-forming agent CD-WPU-Si and a preparation method thereof, which is basically the same as that of Example 1, except that the amount of γ-aminopropyltriethoxysilane (KH550) is changed. The specific steps are as follows: 3) Add 0.33 g of triethylamine (TEA) and 0.08 g of γ-aminopropyltriethoxysilane (KH550) of silicone to solution B, heat under condensation reflux at 40°C under nitrogen atmosphere, and mechanically stir for 1.5 h to obtain solution C; finally, a blue-light milky white liquid is obtained, that is, a cyclodextrin-based water-resistant modified polyurethane film-forming agent (CD-WPU-Si-2) is obtained.

[0035] Example 4

[0036] This embodiment provides a cyclodextrin-based water-resistant modified polyurethane film-forming agent CD-WPU-Si and a preparation method thereof, which is basically the same as that of Example 1, except that the amount of γ-aminopropyltriethoxysilane (KH550) is changed. The specific steps are as follows: 3) Add 0.33 g of triethylamine (TEA) and 0.12 g of γ-aminopropyltriethoxysilane (KH550) to solution B, heat under condensation reflux at 40°C under nitrogen atmosphere, and mechanically stir for 1.5 h to obtain solution C; finally, a blue-light milky white liquid is obtained, that is, a cyclodextrin-based water-resistant modified polyurethane film-forming agent (CD-WPU-Si-3) is obtained.

[0037] Example 5

[0038] This embodiment provides a cyclodextrin-retained resveratrol inclusion compound CD-RES and a preparation method thereof, and the specific steps are as follows: 1) Dissolve 0.08 g of resveratrol in 5 ml of ethanol to obtain solution F; 2) Dissolve 0.05 g of β-cyclodextrin (β-CD) in 10 ml of water to obtain solution G; 3) On a magnetic stirrer, solution F was added dropwise into solution G, and the mixture was stirred for 6 h. The inclusion temperature was 30° C., and the mixture was allowed to stand for a certain period of time. The mixture was filtered to obtain an inclusion complex CD-RES containing only cyclodextrin and resveratrol.

[0039] Example 6

[0040] This embodiment provides a CD-WPU inclusion complex of resveratrol CP-RES and a preparation method thereof, which is basically the same as that of Example 5, except that the specific steps are as follows: 2) Take 10 ml of the CD-WPU prepared in Example 1 as solution G.

[0041] Example 7

[0042] This embodiment provides a CD-WPU-Si inclusion complex of resveratrol CPS-RES-1 (i.e., CD-WPU-SI-RES-1) and a preparation method thereof, which is substantially the same as that of Example 5, except that the specific steps are as follows: 2) Take 10 ml of CD-WPU-Si-3 prepared in Example 4 as solution G.

[0043] Example 8

[0044] This embodiment provides a CD-WPU-Si inclusion complex of resveratrol CPS-RES-2 (i.e., CD-WPU-SI-RES-2) and a preparation method thereof, which is basically the same as Example 5, except that the specific steps are as follows: 1) reducing the concentration of CD-WPU-Si-3, 2) taking 5 ml of CD-WPU-Si-3 prepared in Example 4 and adding 5 ml of water to obtain solution G.

[0045] By performing corresponding tests on the above embodiments, the test results are shown in the attached Figures 1 to 5 As shown: By the attached Figure 1 It can be seen that the CD-WPU-Si curve is at 3325cm -1 The peak at 1632cm is attributed to the stretching vibration of OH in β-CD. -1 The peak at 1034 cm corresponds to the bending vibration absorption peak of OH in β-CD. -1 The peak corresponds to the stretching vibration of CO in β-CD. -1 Compared with the absorption peak of Si-OC at 1075cm in the CD-WPU-Si curve, -1 The absorption peak of CD-WPU-Si curve is different from that of unmodified CD-WPU curve at 1034 cm -1 The CD-WPU-Si curve at 1233 cm -1 The absorption peak at is stronger than that of CD-WPU curve, which may be due to the overlap of the stretching vibration of Si-O-Si and the vibration peak of ester group. The infrared spectrum further shows that β-CD is introduced into WPU and KH550 is successfully cross-linked on CD-WPU chain.

[0046] Attached Figure 2 The relationship between different KH550 contents and contact angles was demonstrated. Four groups of experiments were designed, with the addition amounts of KH550 being 0, 0.04, 0.08, and 0.12 g, respectively. After the sample coating was naturally air-dried, it was placed in an oven at 105°C for 30 minutes, and then tested with a contact angle meter, taking the average value of the three samples. Figure 2It can be seen that the contact angle of CD-WPU-Si is larger than that of CD-WPU, mainly due to the introduction of silicon, which increases the water resistance of the film. When the KH550 content is 0.08, the maximum contact angle is 61.7°. With the increase of the silicone content, the water resistance of the film former is increased, and the waterproof and sweat-proof ability of the makeup product is improved.

[0047] Attached Figure 3 The adhesion test of different concentrations of CD-WPU-Si-1 (Example 2) is shown, which are 2% w / v CD-WPU-Si-1 and 13% w / v CD-WPU-Si-1. After the sample coating is naturally air-dried, it is placed in an oven at 105°C for 30 minutes and then evenly cut with a crosshatch. Figure 3 It can be seen that the cutting edges of 2w / v%CD-WPU-Si-1 and 13w / v%CD-WPU-Si-1 are smooth, and there is no shedding in the grid. According to the GB / T9286-2021 / ISO2409:2020 rating standard, the adhesion is level 0, which has good adhesion, so that the setting makeup product has good anti-scratch ability.

[0048] Attached Figure 4 The UV spectra of the inclusion complex of β-CD, CD-WPU and CD-WPU-Si containing resveratrol are shown. Two different concentrations of 13% w / v CD-WPU-Si-3 and 6% w / v CD-WPU-Si-3 are designed to contain the same amount of resveratrol. The CD-WPU-Si-3 of Example 4 is used, and 1 ml of 0.1M HCl is used to acidify the inclusion complex to remove the inclusion complex. Figure 4 It can be seen that the inclusion complex has an absorption peak at around 300nm. After adding HCl, the acid destroys the cyclodextrin cavity structure, resveratrol is released, and the ultraviolet absorbance increases. Under the same concentration and the same absolute content of resveratrol, the absorbance of high-concentration CPS-RES-1 at around 300nm is higher than that of low-concentration CPS-RES-2 (right figure), indicating that high-concentration CPS-RES-1 contains relatively more resveratrol than low-concentration CPS-RES-2. However, after adding acid, the absorbance of CPS-RES-1 is lower than the ultraviolet absorbance of CPS-RES-2, which may be due to insufficient acidification and incomplete destruction of cyclodextrin. This shows that CD-WPU-Si has the ability to load resveratrol due to the introduction of β-cyclodextrin, which makes the makeup product have skin care effects.

[0049] Attached Figure 5 The UV spectra of the inclusion complex decapsulated by different acids are shown. 0.2 ml of 0.1 M HCl and 2 wt% malic acid (MA) are selected to decapsulate the prepared inclusion complex. Figure 5It can be seen that in the case of pure cyclodextrin inclusion complex CD-RES and low-concentration CPS-RES-2, there is no significant change in UV absorbance after acidification with 0.1M HCl and 2wt% malic acid, indicating that the acidification effect of 2wt% malic acid (MA) is the same as that of 0.1M HCL. After adding acid, the UV absorbance of high-concentration CPS-RES-1 is lower than that of low-concentration CPS-RES-2, which is due to incomplete acidification and incomplete release of the encapsulated resveratrol.

[0050] According to the disclosure and teaching of the above description, those skilled in the art to which the present invention belongs may also make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and changes to the invention should also fall within the scope of protection of the claims of the present invention.

Claims

1. A cyclodextrin-based water-resistant modified polyurethane film-forming agent, characterized in that: The cyclodextrin-based water-resistant modified polyurethane film-forming agent comprises a hydrophilic segment and a hydrophobic segment. The hydrophilic segment comprises a molecular segment formed by raw material cyclodextrin and 2,2-dihydroxymethylbutyric acid, and the hydrophobic segment comprises a molecular segment formed by raw material organosilicon.

2. The cyclodextrin-based water-resistant modified polyurethane film-forming agent according to claim 1, characterized in that: The mass proportion of cyclodextrin in the hydrophilic segment in the cyclodextrin-based water-resistant modified polyurethane film-forming agent is 0.5-0.6wt%; The mass proportion of the organosilicon in the hydrophobic segment in the cyclodextrin-based water-resistant modified polyurethane film-forming agent is 0.5-1.4wt%.

3. The cyclodextrin-based water-resistant modified polyurethane film-forming agent according to claim 1, characterized in that: The cyclodextrin is β-cyclodextrin.

4. The cyclodextrin-based water-resistant modified polyurethane film-forming agent according to claim 1, characterized in that: The organosilicon is γ-aminopropyltriethoxysilane KH550.

5. A method for preparing the cyclodextrin-based water-resistant modified polyurethane film-forming agent according to any one of claims 1 to 4, characterized in that: The steps include: S1. Mix cyclodextrin, solvent, 2,2-dihydroxymethylbutyric acid, polycaprolactone diol, isophorone diisocyanate, and dibutyltin dilaurate, and heat under condensation reflux with stirring for a certain time at a certain temperature to obtain solution A; S2. The chain extender 1,4-butanediol is added to solution A, and the mixture is condensed, refluxed, stirred and heated at a certain temperature for a certain period of time to obtain solution B; S3. triethylamine and organosilicon are added to solution B, and the mixture is condensed, refluxed, stirred and heated at a certain temperature for a certain period of time to obtain solution C; S4. Add pure water to solution C, stir and mix to fully dissolve, and obtain solution D, that is, a cyclodextrin-based water-resistant modified polyurethane film-forming agent.

6. The method for preparing the cyclodextrin-based water-resistant modified polyurethane film-forming agent according to claim 5, characterized in that: The method further comprises step S5 of purifying solution D, wherein the purification is dialysis purification.

7. The method for preparing the cyclodextrin-based water-resistant modified polyurethane film-forming agent according to claim 5, characterized in that: The amount of organic silicon used in step S3 is 0-0.12 g.

8. The method for preparing the cyclodextrin-based water-resistant modified polyurethane film-forming agent according to claim 5, characterized in that: In the step S1, the mass volume ratio of cyclodextrin, solvent, 2,2-dihydroxymethylbutyric acid, polycaprolactone diol, isophorone diisocyanate, and dibutyltin dilaurate is 0.02-0.1 g: 3-10 mL: 0.5-1 g: 3-4 g: 3-5 g: 0.05-0.2 g; in the step S1, the mixture is condensed, refluxed, stirred, and heated at 70-80° C. under a nitrogen atmosphere for 1-2 h.

9. The method for preparing the cyclodextrin-based water-resistant modified polyurethane film-forming agent according to claim 5, characterized in that: The amount of 1,4-butanediol added in step S2 is 0.48 g; In the step S2, the mixture is heated under condensation reflux with stirring at 70-80° C. for 1.5-2 h under a nitrogen atmosphere.

10. The method for preparing the cyclodextrin-based water-resistant modified polyurethane film-forming agent according to claim 5, characterized in that: The amount of triethylamine added in step S3 is 0.33 g; In the step S3, the mixture is heated under condensation reflux with stirring at 40-50° C. for 1.5-2 h under a nitrogen atmosphere.

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