Sunscreen color complementing agent and preparation method thereof

Abstract

The invention relates to the field of coatings, and provides a sunscreen color complementing agent and a preparation method thereof.The sunscreen color complementing agent is prepared from, by weight, 5%-10% of silicate, 5%-10% of silicon dioxide, 3%-8% of ferric oxide, 0.5%-1% of organic silicon, 5%-10% of vegetable gum, 1%-3% of ultraviolet light absorber, 0.5%-1% of composite bio-based antibacterial agent and the balance deionized water, wherein the composite bio-based antibacterial agent is a mixture of modified cinnamon essential oil and carvacrol. The sunscreen color complementing agent provided by the invention has good ultraviolet shielding effect and antibacterial property, can be widely applied to the field of agriculture, and has better commercial application value.

Description

Technical Field

[0001] The invention relates to the field of coatings, and in particular to a sunscreen color-correcting agent and a preparation method thereof. Background Art

[0002] During the growth process, crops need to be exposed to sunlight, but the impact of sunlight on crops is complex. It is beneficial to the growth and development of crops and is a necessary factor for the growth of crops. However, some extreme climatic conditions, such as high temperature and strong light, can also have a negative effect on the growth of crops and even cause damage to crops. For example, excessive ultraviolet rays can destroy the chlorophyll in plant leaves, inhibit the efficiency of photosynthesis, and cause crops to wither and fade. Excessive light and high temperature can burn the peel of crops and increase the photorespiration of crops themselves, leading to problems such as soft flesh and decreased sugar content. The red light in visible light can accelerate the synthesis of anthocyanins in crop fruits and play a role in color supplementation. However, in actual applications, there is a problem of excessive loss of red light. Therefore, it is particularly important to develop materials that can simultaneously protect crops from the sun and supplement their colors.

[0003] At present, people usually apply some coatings with heat insulation and UV shielding functions on the greenhouse film of crops to achieve the effect of sun protection. The main sunscreens are UV absorbers composed of indium tin oxide, antimony tin oxide and some rare earth materials, but they all have poor dispersion and cannot make the coatings sun-proof for a long time. In addition, adding antibacterial agents to greenhouse film coatings is also very important for the growth of crops, but the antibacterial agents currently on the market are not environmentally friendly enough or the stability of bio-based antibacterial agents is poor.

[0004] Patent CN 109836893B discloses an ultra-high weather resistance, low light transmittance, high thermal insulation inorganic functional slurry and a preparation method thereof. The inorganic functional slurry prepared in this application is composed of a dispersant, an inorganic thermal insulation pigment nanopowder and a solvent. It has the properties of high clarity, ultra-high weather resistance, low light transmittance, high thermal insulation and high UV isolation. It can be widely used in coatings, inks, window films, textiles, plastic sheets, plastic greenhouses and glass laminated films. However, this application does not solve the problem of excessive loss of red light in visible light and does not have good color-complementing properties for crops.

[0005] Therefore, there is an urgent need for a sunscreen color-correcting agent with good ultraviolet shielding effect and antibacterial property on the market. Summary of the invention

[0006] In view of the problems existing in the prior art, the present invention adds silicate, silicon dioxide, iron oxide, silicone, plant gum, ultraviolet absorber and composite bio-based antibacterial agent into deionized water to synthesize a sunscreen color corrector with good ultraviolet shielding effect and antibacterial property.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] On one hand, the present invention provides a sunscreen color corrector, which comprises the following raw materials, calculated by 100wt%, including 5-10wt% of silicate, 5-10wt% of silicon dioxide, 3-8wt% of iron oxide, 0.5-1wt% of organosilicon, 5-10wt% of plant gum, 1-3wt% of ultraviolet absorber, 0.5-1wt% of composite bio-based antibacterial agent, and the rest of deionized water, wherein the composite bio-based antibacterial agent is a mixture of modified cinnamon essential oil and carvacrol.

[0009] Wherein, the silicate is sodium silicate or potassium silicate; the organosilicon is dimethylsiloxane or methylphenylsiloxane; and the plant gum is guar gum or fenugreek gum.

[0010] In some embodiments of the present invention, the iron oxide is transparent iron oxide.

[0011] The transparent iron oxide selected by the applicant has the function of shielding blue light in visible light and enhancing the transmission intensity of red light in visible light, which is beneficial to promote the synthesis of anthocyanins in plant fruits, accelerate the coloring of crops, and play a role in color complementation.

[0012] In some embodiments of the present invention, the method for preparing the ultraviolet absorber comprises the following steps:

[0013] (1) adding cerium nitrate hexahydrate and lanthanum nitrate hexahydrate to anhydrous ethanol, heating to 30-40° C., stirring, and obtaining solution 1 for later use; adding curcumin to anhydrous ethanol, heating to 35-45° C., stirring, and obtaining solution 2 for later use;

[0014] (2) adding solution 1 of step (1) into solution 2, adding sodium hydroxide aqueous solution, stirring, standing, suction filtering, washing, suction filtering, drying, and obtaining a complex for use;

[0015] (3) Add oleic acid amide to anhydrous ethanol, heat to 60-80° C., stir, add the complex of step (2), stir, and dry to obtain an ultraviolet absorber.

[0016] In some embodiments of the present invention, in step (1), the molar ratio of cerium nitrate hexahydrate, lanthanum nitrate hexahydrate and curcumin is 1:(2.5-3):(2.5-3.5).

[0017] Preferably, in step (1), the molar ratio of cerium nitrate hexahydrate, lanthanum nitrate hexahydrate and curcumin is 1:2.7:3.

[0018] In some embodiments of the present invention, in step (3), the mass ratio of the complex to oleamide is 1:(0.08-0.12).

[0019] Preferably, in step (3), the mass ratio of the complex to oleamide is 1:0.1.

[0020] The rare earth elements cerium and lanthanum have special optical and chemical properties that enable them to absorb ultraviolet rays well, giving them good application prospects in the field of sun protection. Rare earth lanthanum can also produce red light after absorbing ultraviolet light, thereby achieving the effect of complementing the color of crops. Currently, rare earth elements are often added to coatings and other materials in the form of oxides to improve their ultraviolet shielding effect, but rare earth oxides have the problem of poor dispersion.

[0021] On the one hand, the applicant uses a mixed rare earth salt solution composed of cerium nitrate hexahydrate and lanthanum nitrate hexahydrate to act on curcumin. The ketone group in curcumin enables it to have a good ultraviolet absorption function, thereby playing a role in shielding ultraviolet rays. In addition, the rare earth cerium ions and lanthanum ions coordinate with the hydroxyl oxygen and carbonyl oxygen in curcumin to form a complex, which has a good ultraviolet shielding effect while also improving the stability of the ultraviolet absorber. Furthermore, the applicant controls the ratio of cerium nitrate hexahydrate and lanthanum nitrate hexahydrate to maximize the synergistic ultraviolet shielding activity of cerium and lanthanum. On the other hand, the applicant adds oleic acid amide to the above-mentioned complex. Oleic acid amide is amphiphilic, which can make the prepared ultraviolet absorber well dispersed in the sunscreen toner, and the carbon-carbon double bonds in oleic acid amide and the carbon-carbon double bonds in curcumin may form a certain cross-linking trend, making the ultraviolet absorber more stable as a whole.

[0022] In some embodiments of the present invention, the mass ratio of modified cinnamon essential oil to carvacrol in the composite bio-based antibacterial agent is 1:(0.4-0.6).

[0023] Preferably, the mass ratio of modified cinnamon essential oil to carvacrol in the composite bio-based antibacterial agent is 1:0.5.

[0024] In some embodiments of the present invention, the method for preparing the modified cinnamon essential oil comprises the following steps:

[0025] 1) adding gallic acid to tetrahydrofuran and stirring to obtain liquid 1 for later use, adding beet pectin to deionized water and stirring to obtain liquid 2 for later use, mixing liquid 1 and liquid 2, stirring at 50-70° C. for 23-25 ​​h, rotary evaporating, dialyzing, and freeze-drying to obtain product 1 for later use;

[0026] 2) adding egg yolk lecithin, cholesterol, zein, product 1 of step 1), Tween 20 and cinnamon essential oil into anhydrous ethanol, heating to 65-75° C., stirring, rotary evaporation, adding PBS buffer, ultrasonication, homogenization, and obtaining product 2 for later use;

[0027] 3) adding chitosan to an acetic acid aqueous solution and stirring to obtain a 0.3-0.5 wt % liquid 3 for later use, adding sodium alginate to deionized water and stirring to obtain a 0.01-0.03 wt % liquid 4 for later use;

[0028] 4) adding product 2 to liquid 3, stirring, and then adding to liquid 4, stirring, to obtain modified cinnamon essential oil.

[0029] Wherein, in said step 4), the volume ratio of the product 2, the liquid 3 and the liquid 4 is 1:(0.8-1.2):(1.5-2.5).

[0030] Preferably, in step 4), the volume ratio of product 2, liquid 3 and liquid 4 is 1:1:1.

[0031] In some embodiments of the present invention, in step 1), the mass ratio of beet pectin to gallic acid is 1:(0.45-0.55).

[0032] Preferably, in step 1), the mass ratio of beet pectin to gallic acid is 1:0.51.

[0033] In some embodiments of the present invention, in step 2), the mass ratio of cinnamon essential oil to product 1 is 1:(0.4-0.8).

[0034] Preferably, in the step 2), the mass ratio of cinnamon essential oil to product 1 is 1:0.6.

[0035] The applicant compounded the modified cinnamon essential oil and carvacrol, which has a synergistic antibacterial effect, and carvacrol can also improve the problem of the strong odor of cinnamon essential oil.

[0036] As a bio-based natural substance, cinnamon essential oil has significant inhibitory effects on bacteria, fungi and viruses. It is an effective antibacterial agent and also has good antioxidant effects. However, cinnamon essential oil is volatile and sensitive to light and heat, which makes it unstable. Direct use will greatly reduce its effectiveness.

[0037] The applicant uses egg yolk lecithin, cholesterol, zein and gallic acid-modified beet pectin (product 1) to embed cinnamon essential oil to form cinnamon essential oil liposomes (product 2), and then introduces chitosan and sodium alginate to perform double-layer modification on the cinnamon essential oil liposomes to improve the stability and antibacterial properties of cinnamon essential oil. On the one hand, the applicant controls the ratio of phospholipids and cholesterol to form hydrogen bonds between the hydrophilic hydroxyl groups and the polar groups of the phospholipid molecules, and uses the interaction between hydrogen bonds to adjust the rigidity and density of the lipid membrane, thereby improving the stability of the liposomes, thereby improving the loading capacity of the liposomes for cinnamon essential oil, and improving the stability of the cinnamon essential oil. In addition, the applicant adds Tween 20, the hydrophilic long-chain structure in its structure can make the liposomes have a certain steric hindrance effect, making the cinnamon essential oil liposome system firm and stable. Furthermore, the applicant introduces zein and gallic acid-modified beet pectin, and the combination of the two can protect the activity of cinnamon essential oil to a certain extent and improve the cinnamon essential oil. The invention discloses a novel cinnamon essential oil liposome, wherein the cinnamon essential oil liposome is a liposome of cinnamon oil, and the cinnamon essential oil liposome is a liposome of cinnamon oil. The ...

[0038] Another aspect of the present invention further provides a method for preparing the sunscreen color-correcting agent described in the above technical solution, comprising the following steps:

[0039] Silicate, silicon dioxide, iron oxide, organic silicon, vegetable gum, ultraviolet absorber and composite bio-based antibacterial agent are added into deionized water and stirred to obtain a sunscreen color corrector.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] (1) The present invention adds silicate, silicon dioxide, iron oxide, silicone, plant gum, ultraviolet absorber and composite bio-based antibacterial agent into deionized water to synthesize a sunscreen color corrector. Through the synergistic effect of the components, the sunscreen color corrector has the advantages of good ultraviolet shielding effect and antibacterial property.

[0042] (2) The present invention uses transparent iron oxide, which is beneficial to enhancing the transmission intensity of red light, thereby playing a role in color complementation.

[0043] (3) The present invention uses a mixed rare earth salt solution composed of cerium nitrate hexahydrate and lanthanum nitrate hexahydrate to react with curcumin to form a complex, which has good ultraviolet shielding function and improves the stability of the ultraviolet absorber. In addition, oleic acid amide is introduced to make the ultraviolet absorber have good dispersibility in the sunscreen toner system.

[0044] (4) The present invention uses the bio-based antibacterial agent cinnamon essential oil as the main component, modifies it to form cinnamon essential oil liposomes, then introduces chitosan and sodium alginate to perform double-layer modification on the cinnamon essential oil liposomes to improve the stability and antibacterial property of the cinnamon essential oil, and then forms a composite bio-based antibacterial agent with carvacrol to achieve a synergistic antibacterial effect.

[0045] (5) The sunscreen color corrector prepared by the present invention has good ultraviolet shielding effect and antibacterial property, can be widely used in the agricultural field, and has good commercial application value. DETAILED DESCRIPTION

[0046] The present invention will be described below in conjunction with specific embodiments. It should be noted that the following embodiments are examples of the present invention and are only used to illustrate the present invention, but not to limit the present invention. Other combinations and various modifications within the concept of the present invention may be performed without departing from the spirit or scope of the present invention.

[0047] In the following examples and comparative examples, except for the ultraviolet absorber and modified cinnamon essential oil, the other compound monomers and related reagents used can be purchased from the market, among which guar gum was purchased from Henan Kangzhiwang Biotechnology Co., Ltd.; fennel gum was purchased from Shaanxi Chenming Biotechnology Co., Ltd.; beet pectin was purchased from Azelis International Trade (Shanghai) Co., Ltd.; Tween 20 was purchased from Guangdong Mingtong Biotechnology Co., Ltd.; cinnamon essential oil was purchased from Jiangxi Global Natural Flavors Co., Ltd.; chitosan was purchased from Huantai County Jinhu Crust Products Co., Ltd.

[0048] Preparation Example 1

[0049] The synthesis method of ultraviolet light absorber A comprises the following steps:

[0050] (1) adding 0.02 mol of cerium nitrate hexahydrate and 0.054 mol of lanthanum nitrate hexahydrate to 50 ml of anhydrous ethanol, heating to 35° C., stirring for 20 min, and obtaining solution 1 for later use; adding 0.06 mol of curcumin to 60 ml of anhydrous ethanol, heating to 40° C., stirring for 20 min, and obtaining solution 2 for later use;

[0051] (2) Add solution 1 of step (1) to solution 2, add 2 ml of 1 mol / L sodium hydroxide aqueous solution, stir for 10 min, let stand for 24 h, filter with suction, wash with anhydrous ethanol three times, filter with suction, and dry at 60° C. for 12 h to obtain a complex for use;

[0052] (3) Add 1 g of oleic acid amide to 30 ml of anhydrous ethanol, heat to 70° C., stir for 1.5 h, add 10 g of the complex prepared in step (2), stir for 1 h, and dry at 105° C. for 12 h to obtain UV absorber A.

[0053] Preparation Example 2

[0054] The specific implementation manner of the ultraviolet absorber B is the same as that of the ultraviolet absorber A, except that in step (1), the molar number of lanthanum nitrate hexahydrate is replaced with 0.04 mol.

[0055] Preparation Example 3

[0056] The specific implementation manner of the ultraviolet absorber C is the same as that of the ultraviolet absorber A, except that in step (1), the molar number of curcumin is replaced with 0.03 mol.

[0057] Preparation Example 4

[0058] The specific implementation manner of the ultraviolet absorber D is the same as that of the ultraviolet absorber A, except that in step (3), the mass of oleamide is replaced with 0.5 g.

[0059] Preparation Example 5

[0060] The synthetic method of modified cinnamon essential oil A comprises the following steps:

[0061] 1) Add 5.1 g of gallic acid to 300 ml of tetrahydrofuran and stir for 20 min to obtain liquid 1 for later use; add 10 g of beet pectin to 300 ml of deionized water and stir for 15 min to obtain liquid 2 for later use; mix liquid 1 and liquid 2, stir at 60° C. for 24 h, rotary evaporate, dialyze with deionized water for 96 h, and freeze-dry at -40° C. for 96 h to obtain product 1 for later use;

[0062] 2) 1 g of egg yolk lecithin, 0.25 g of cholesterol, 0.35 g of zein, 0.15 g of the product 1 of step 1), 0.25 g of Tween 20 and 0.25 g of cinnamon essential oil were added to 100 ml of anhydrous ethanol, heated to 70° C., stirred for 30 min, rotary evaporated at 40° C., added with 40 ml of 0.01 mol / L PBS buffer, ultrasonicated for 10 min, and homogenized (first sheared at 10000 r / min for 2 min in a normal pressure homogenizer, and then cycled 3 times under 60 MPa high pressure homogenization) to obtain product 2 for use;

[0063] 3) adding 0.4 g of chitosan to 100 ml of 1 wt% acetic acid aqueous solution, stirring for 20 min, obtaining 0.4 wt% of liquid 3 for standby use, adding 0.02 g of sodium alginate to 100 ml of deionized water, stirring for 20 min, obtaining 0.02 wt% of liquid 4 for standby use;

[0064] 4) Add 5 ml of product 2 to 5 ml of liquid 3, stir for 1 hour, then add to 10 ml of liquid 4, and stir for 1 hour to obtain modified cinnamon essential oil A.

[0065] Preparation Example 6

[0066] The specific implementation method of modified cinnamon essential oil B is the same as that of modified cinnamon essential oil A, except that in step 1), the mass of gallic acid is replaced with 4 g.

[0067] Preparation Example 7

[0068] The specific implementation manner of modified cinnamon essential oil C is the same as that of modified cinnamon essential oil A, except that in step 2), the mass of product 1 is replaced with 0.08 g.

[0069] Preparation Example 8

[0070] The specific implementation manner of modified cinnamon essential oil D is the same as that of modified cinnamon essential oil A, except that in step 4), the volume of liquid 3 is replaced with 3 ml.

[0071] Preparation Example 9

[0072] The specific implementation manner of modified cinnamon essential oil E is the same as that of modified cinnamon essential oil A, except that in step 4), the volume of liquid 4 is replaced with 6 ml.

[0073] Example 1

[0074] A sunscreen color corrector comprises the following raw materials, calculated as 100wt%, including 7.5wt% of sodium silicate, 7.5wt% of silicon dioxide, 5.5wt% of transparent iron oxide, 0.75wt% of dimethylsiloxane, 7.5wt% of guar gum, 2wt% of ultraviolet absorber A, 0.75wt% of composite bio-based antibacterial agent, and the rest is deionized water, wherein the composite bio-based antibacterial agent is a mixture of modified cinnamon essential oil A and carvacrol, and the mass ratio is 1:0.5.

[0075] The preparation method of the sunscreen color-correcting agent in this embodiment comprises the following steps:

[0076] Sodium silicate, silicon dioxide, transparent iron oxide, dimethylsiloxane, guar gum, ultraviolet absorber A and composite bio-based antibacterial agent are added into deionized water and stirred for 2 hours to obtain a sunscreen color corrector.

[0077] Example 2

[0078] A sunscreen color corrector comprises the following raw materials, calculated as 100wt%, including 5wt% potassium silicate, 5wt% silicon dioxide, 3wt% transparent iron oxide, 0.5wt% methylphenylsiloxane, 5wt% fennel gum, 2wt% ultraviolet absorber A, 0.5wt% composite bio-based antibacterial agent, and the rest is deionized water, wherein the composite bio-based antibacterial agent is a mixture of modified cinnamon essential oil A and carvacrol, and the mass ratio is 1:0.4.

[0079] The preparation method of the sunscreen color-correcting agent in this embodiment comprises the following steps:

[0080] Potassium silicate, silicon dioxide, transparent iron oxide, methylphenylsiloxane, fennel gum, ultraviolet absorber A and composite bio-based antibacterial agent are added into deionized water and stirred for 2 hours to obtain a sunscreen color corrector.

[0081] Example 3

[0082] A sunscreen color corrector comprises the following raw materials, calculated as 100wt%, including 10wt% sodium silicate, 10wt% silicon dioxide, 8wt% transparent iron oxide, 1wt% methylphenylsiloxane, 10wt% fennel gum, 2wt% ultraviolet absorber A, 1wt% composite bio-based antibacterial agent, and the rest is deionized water, wherein the composite bio-based antibacterial agent is a mixture of modified cinnamon essential oil A and carvacrol, and the mass ratio is 1:0.6.

[0083] The preparation method of the sunscreen color-correcting agent in this embodiment comprises the following steps:

[0084] Sodium silicate, silicon dioxide, transparent iron oxide, methylphenylsiloxane, fennel gum, ultraviolet absorber A and composite bio-based antibacterial agent are added into deionized water and stirred for 2 hours to obtain a sunscreen color corrector.

[0085] Example 4

[0086] A sunscreen color corrector comprises the following raw materials, calculated as 100wt%, including 6wt% of sodium silicate, 6wt% of silicon dioxide, 4wt% of transparent iron oxide, 0.6wt% of dimethylsiloxane, 6wt% of guar gum, 1wt% of ultraviolet absorber A, 0.75wt% of composite bio-based antibacterial agent, and the rest of deionized water, wherein the composite bio-based antibacterial agent is a mixture of modified cinnamon essential oil A and carvacrol, and the mass ratio is 1:0.5.

[0087] The preparation method of the sunscreen color correcting agent in this embodiment is the same as that in Example 1.

[0088] Example 5

[0089] A sunscreen color corrector comprises the following raw materials, calculated as 100wt%, including 9wt% of sodium silicate, 9wt% of silicon dioxide, 7wt% of transparent iron oxide, 0.9wt% of dimethylsiloxane, 9wt% of guar gum, 3wt% of ultraviolet absorber A, 0.75wt% of composite bio-based antibacterial agent, and the rest is deionized water, wherein the composite bio-based antibacterial agent is a mixture of modified cinnamon essential oil A and carvacrol, and the mass ratio is 1:0.5.

[0090] The preparation method of the sunscreen color correcting agent in this embodiment is the same as that in Example 1.

[0091] Example 6

[0092] This embodiment provides a sunscreen color correcting agent and a preparation method thereof. The specific implementation method is the same as that of Embodiment 1, except that the ultraviolet absorber A is replaced by an equal amount of ultraviolet absorber B.

[0093] Example 7

[0094] This embodiment provides a sunscreen color correcting agent and a preparation method thereof. The specific implementation method is the same as that of Example 1, except that the ultraviolet absorber A is replaced by an equal amount of ultraviolet absorber C.

[0095] Example 8

[0096] This embodiment provides a sunscreen color correcting agent and a preparation method thereof. The specific implementation method is the same as that of Example 1, except that the ultraviolet absorber A is replaced by an equal amount of ultraviolet absorber D.

[0097] Example 9

[0098] This embodiment provides a sunscreen color correcting agent and a preparation method thereof. The specific implementation method is the same as that of Example 1, except that the modified cinnamon essential oil A is replaced by the modified cinnamon essential oil B in an equal amount.

[0099] Example 10

[0100] This embodiment provides a sunscreen color correcting agent and a preparation method thereof. The specific implementation method is the same as that of Example 1, except that the modified cinnamon essential oil A is replaced by the modified cinnamon essential oil C in an equal amount.

[0101] Embodiment 11

[0102] This embodiment provides a sunscreen color correcting agent and a preparation method thereof. The specific implementation method is the same as that of Example 1, except that the modified cinnamon essential oil A is replaced by an equal amount of modified cinnamon essential oil D.

[0103] Example 12

[0104] This embodiment provides a sunscreen color correcting agent and a preparation method thereof. The specific implementation method is the same as that of Example 1, except that the modified cinnamon essential oil A is replaced by the modified cinnamon essential oil E in an equal amount.

[0105] Embodiment 13

[0106] This embodiment provides a sunscreen color correcting agent and a preparation method thereof. The specific implementation method is the same as that of Example 1, except that an equal amount of cerium oxide is used to replace the ultraviolet absorber A.

[0107] Comparative Example 1

[0108] This comparative example provides a sunscreen color correcting agent and a preparation method thereof. The specific implementation method is the same as that of Example 1, except that an equal amount of cinnamon essential oil is used to replace the modified cinnamon essential oil A.

[0109] Performance Testing

[0110] The ultraviolet shielding performance and antibacterial property of the sunscreen color corrector of the above-mentioned Examples 1-13 and Comparative Example 1 were tested, and the test results are shown in Table 1.

[0111] The sunscreen color corrector obtained in Examples 1-13 and Comparative Example 1 was diluted 10 times by mass with deionized water and then coated on the same agricultural greenhouse film to a thickness of 0.003 mm, and the ultraviolet shielding performance and antibacterial property of the film coated with the sunscreen color corrector were tested.

[0112] (1) Ultraviolet shielding performance

[0113] The film coated with the sunscreen color corrector was subjected to a UV / NIR diffuse reflectance test using a Shimadzu UV-3600i Plus UV-visible-near-infrared spectrophotometer from Japan.

[0114] (2) Antibacterial properties

[0115] The antibacterial property of the film coated with the sunscreen color corrector is tested. The antibacterial property is judged by the antibacterial rate. When the antibacterial rate is not less than 90%, it means that the sample has an antibacterial effect; when the antibacterial rate is not less than 99%, it means that the sample has a good antibacterial effect. The GB / T 21866-2008 method is used for testing

[0116] Table 1

[0117]

[0118]

[0119] It can be seen from the data in Table 1 that the sunscreen color correcting agents in Examples 1-5 of the present invention have good ultraviolet shielding performance and antibacterial properties as a whole. Among them, Examples 6-8 respectively changed the addition amounts of lanthanum nitrate hexahydrate, curcumin and oleamide in the synthesis process of the ultraviolet absorber, thereby reducing the ultraviolet shielding effect, stability and dispersibility of the ultraviolet absorber, resulting in a decrease in the ultraviolet blocking rate of the sunscreen color corrector, but having little effect on the antibacterial property; Examples 9-12 changed the modification ratio of gallic acid to beet pectin in the modified cinnamon essential oil, the modification ratio of beet pectin modified by egg yolk lecithin and other substances to cinnamon essential oil, and the modification ratio of chitosan and sodium alginate to cinnamon essential oil, so that the stability of cinnamon essential oil was not significantly improved, thereby resulting in a decrease in the antibacterial property of the sunscreen color corrector, but having little effect on the ultraviolet shielding performance; Example 13 and Comparative Example 1 respectively selected cerium oxide and cinnamon essential oil to replace the ultraviolet absorber A and the modified cinnamon essential oil A in equal amounts, and the test found that the ultraviolet shielding performance and antibacterial property of the sunscreen color corrector both showed poor results.

[0120] The above implementation modes are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the content of the present invention and implement it, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A sunscreen color-correcting agent, characterized in that: The sunscreen color corrector comprises the following raw materials based on 100wt%: 5-10wt% silicate, 5-10wt% silicon dioxide, 3-8wt% iron oxide, 0.5-1wt% silicone, 5-10wt% plant gum, 1-3wt% ultraviolet absorber, 0.5-1wt% composite bio-based antibacterial agent, and the rest is deionized water, wherein the composite bio-based antibacterial agent is a mixture of modified cinnamon essential oil and carvacrol.

2. The sunscreen color correcting agent according to claim 1, characterized in that: The iron oxide is transparent iron oxide.

3. The sunscreen color correcting agent according to claim 1, characterized in that: The preparation method of the ultraviolet absorber comprises the following steps: (1) adding cerium nitrate hexahydrate and lanthanum nitrate hexahydrate to anhydrous ethanol, heating to 30-40° C., stirring, and obtaining solution 1 for later use; adding curcumin to anhydrous ethanol, heating to 35-45° C., stirring, and obtaining solution 2 for later use; (2) adding solution 1 of step (1) into solution 2, adding sodium hydroxide aqueous solution, stirring, standing, suction filtering, washing, suction filtering, drying, and obtaining a complex for use; (3) Add oleic acid amide to anhydrous ethanol, heat to 60-80° C., stir, add the complex of step (2), stir, and dry to obtain an ultraviolet absorber.

4. The sunscreen color correcting agent according to claim 3, characterized in that: In the step (1), the molar ratio of cerium nitrate hexahydrate, lanthanum nitrate hexahydrate and curcumin is 1:(2.5-3):(2.5-3.5).

5. The sunscreen color correcting agent according to claim 3, characterized in that: In the step (3), the mass ratio of the complex to oleamide is 1:(0.08-0.12).

6. The sunscreen color correcting agent according to claim 1, characterized in that: The mass ratio of modified cinnamon essential oil to carvacrol in the composite bio-based antibacterial agent is 1:(0.4-0.6).

7. The sunscreen color correcting agent according to claim 6, characterized in that: The preparation method of the modified cinnamon essential oil comprises the following steps: 1) adding gallic acid to tetrahydrofuran and stirring to obtain liquid 1 for later use, adding beet pectin to deionized water and stirring to obtain liquid 2 for later use, mixing liquid 1 and liquid 2, stirring at 50-70° C. for 23-25 ​​h, rotary evaporating, dialyzing, and freeze-drying to obtain product 1 for later use; 2) adding egg yolk lecithin, cholesterol, zein, product 1 of step 1), Tween 20 and cinnamon essential oil into anhydrous ethanol, heating to 65-75° C., stirring, rotary evaporation, adding PBS buffer, ultrasonication, homogenization, and obtaining product 2 for later use; 3) adding chitosan to an acetic acid aqueous solution and stirring to obtain a 0.3-0.5 wt % liquid 3 for later use, adding sodium alginate to deionized water and stirring to obtain a 0.01-0.03 wt % liquid 4 for later use; 4) adding product 2 to liquid 3, stirring, and then adding to liquid 4, stirring, to obtain modified cinnamon essential oil.

8. The sunscreen color correcting agent according to claim 7, characterized in that: In the step 1), the mass ratio of beet pectin to gallic acid is 1:(0.45-0.55).

9. The sunscreen color correcting agent according to claim 7, characterized in that: In the step 2), the mass ratio of cinnamon essential oil to product 1 is 1:(0.4-0.8).

10. A method for preparing the sunscreen color-correcting agent according to any one of claims 1 to 9, characterized in that: The following steps are involved: Silicate, silicon dioxide, iron oxide, organic silicon, vegetable gum, ultraviolet absorber and composite bio-based antibacterial agent are added into deionized water and stirred to obtain a sunscreen color corrector.

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