CN113116773A

CN113116773A - Mild liquid cosmetic with whitening and skin moisture improving functions

Info

Publication number: CN113116773A
Application number: CN202110294299.6A
Authority: CN
Inventors: 张文龙
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-03-19
Filing date: 2021-03-19
Publication date: 2021-07-16

Abstract

The invention discloses a mild liquid cosmetic with whitening and skin moisture improving functions, which comprises the following raw materials in parts by weight: 2-12 parts of grease, 800.1-0.3 part of span, 6-8 parts of nutrient components, 0.2-0.8 part of antioxidant, 20-30 parts of natural plant extract, 100 parts of deionized water and 120 parts of humectant, and 7-9 parts of humectant; the liquid cosmetic is prepared by the following steps: firstly, mixing grease and span 80, setting the temperature at 80 ℃, stirring for 5min, standing and cooling to 40 ℃ to obtain a first component; secondly, mixing the nutrient components, the antioxidant, the natural plant extract and deionized water to obtain a second component; and thirdly, mixing the first component and the second component, adding a humectant, adjusting the pH value to 6-6.5 by using a pH regulator, standing and filtering to obtain the mild liquid cosmetic with the functions of whitening and improving skin moisture.

Description

Mild liquid cosmetic with whitening and skin moisture improving functions

Technical Field

The invention belongs to the technical field of cosmetics, and particularly relates to a mild liquid cosmetic with whitening and skin moisture improving functions.

Background

The skin is the largest organ of human body, the total weight accounts for 5% -15% of the body weight, the total area is 1.5-2 square meters, and the thickness is 0.5-4 mm depending on the human body or the part. The skin covers the whole body and is closely connected with other organs of the human body, thereby playing the role of protecting the human body from external stimulation or injury. The skin has a barrier effect in two ways: on one hand, the loss of water, electrolyte and other substances in the body is prevented; on the other hand, the invasion of the outside harmful substances is prevented. Keeps the stability of the internal environment of the human body, plays an important protection function in physiology, and simultaneously, the skin also participates in the metabolic process of the human body.

The synthesis of melanin is a series of complex enzymatic oxidation reactions, wherein tyrosine or dopa is used as a substrate, and dopaquinone is produced through oxidation under the catalytic action of tyrosinase, the oxidation reaction process is a key rate-limiting reaction in the synthesis of melanin, and the overexpression of tyrosinase is a main cause of hyperpigmentation. Therefore, inhibiting the oxidation reaction or the activity of tyrosinase can block the biosynthesis reaction chain of melanin, reduce the generation of melanin, and achieve the whitening effect. In recent years, more and more compounds have been proved to be effective in inhibiting tyrosinase activity, which are called tyrosinase inhibitors, such as kojic acid, arbutin, vitamin C derivatives and some natural extracts. However, vitamin C is unstable, not easily absorbed by the skin, and difficult to be widely used; arbutin is a compound containing phenol group, has slow inhibition effect on tyrosinase although being safe, has good light absorption and is not suitable for being used in the daytime; kojic acid has remarkable whitening and freckle removing effects but has certain toxicity, and cannot be used for a long time.

Disclosure of Invention

The invention provides a mild liquid cosmetic with whitening and skin moisture improving functions.

The technical problems to be solved by the invention are as follows:

the skin moisturizing cream has the effects of improving the water locking capacity of the skin, reducing the melanin content of the skin and moisturizing. Vitamin C can reduce the formed melanin into colorless melanin precursor by using its own strong antioxidant effect, and improve skin darkness effect. Vitamin C has strong reducibility, is easy to oxidize and destroy, loses original reducibility, and is generally coated by liposome, but the liposome is easy to oxidize and decompose and is not beneficial to storage.

The purpose of the invention can be realized by the following technical scheme:

a mild liquid cosmetic with whitening and skin moisture improving functions comprises the following raw materials in parts by weight:

2-12 parts of grease, 800.1-0.3 part of span, 6-8 parts of nutrient components, 0.2-0.8 part of antioxidant, 20-30 parts of natural plant extract, 100 parts of deionized water and 120 parts of humectant, and 7-9 parts of humectant;

the mild liquid cosmetic with the functions of whitening and improving skin moisture is prepared by the following steps:

firstly, mixing grease and span 80, setting the temperature at 80 ℃ and the rotating speed at 200r/min, stirring for 5min, standing and cooling to 40 ℃ to obtain a first component;

secondly, mixing the nutrient components, the antioxidant, the natural plant extract and deionized water to obtain a second component;

and thirdly, mixing the first component and the second component, adding a humectant, adjusting the pH value to 6-6.5 by using a pH regulator, standing and filtering to obtain the mild liquid cosmetic with the functions of whitening and improving skin moisture.

Further, the grease is one or two of olive oil and jojoba oil which are mixed according to any proportion; the humectant is one or more of sodium hyaluronate, trimethylglycine, methylglycine proline and xylitol glucoside which are mixed according to any proportion; the pH regulator is citric acid-sodium citrate; the nutrient component is small molecular polypeptide.

Further, the natural plant extract is rose water, which is another product in the process of constant production of rose essential oil, and contains saturated aqueous solution of rose essential oil. The rose water contains moisturizing factor, can be fully absorbed by skin and can keep moisture, and the antioxidant mainly contains vitamin C, and can inhibit tyrosinase activity, thereby reducing melanin generation. Meanwhile, vitamin C can also reduce the formed melanin into colorless melanin precursor by utilizing the strong antioxidation of the vitamin C, thereby improving the effect of skin darkness. The vitamin C has strong reducibility, is easy to oxidize and damage, loses the original reducibility, is generally coated by liposome, but the liposome is easy to oxidize and decompose and is not beneficial to storage, and the stability of the liposome is improved by modifying the sodium alginate, so that the antioxidation effect of the vitamin C is better exerted.

Further, the antioxidant is prepared by the following steps:

step S21, adding the egg acid ester, the auxiliary agent and the Tween-80 into absolute ethyl alcohol, setting the temperature at 25 ℃ and the rotating speed at 300r/min, stirring for 6-10min, transferring the obtained reaction solution into a rotary evaporator after stirring is finished, and performing reduced pressure evaporation for 50min at the temperature of 55 ℃ to obtain a mixture A;

and step S22, adding vitamin C into 0.05mol/L phosphate buffer solution for mixing, transferring the mixture into the mixture A after mixing, stirring for 15-20min at the temperature of 0-5 ℃ and the rotating speed of 200r/min, and after stirring is finished, performing ultrasonic dispersion for 20min at the temperature of 0-5 ℃ and the frequency of 40kHz to obtain the antioxidant.

Further, in the step S21, the dosage ratio of the egg acid ester, the auxiliary agent, the tween-80 and the absolute ethyl alcohol is 1 g: 0.4-0.8 g: 0.3 g: 50 mL; the dosage ratio of the vitamin C, the 0.05mol/L phosphate buffer solution and the mixture A in the step S22 is 0.3 g: 100mL of: 1-2 g.

Further, the auxiliary agent is prepared by the following steps:

step S31, adding modified sodium alginate into a round-bottom flask, adding dimethyl sulfoxide, setting the temperature to be 50 ℃ and the rotating speed to be 300r/min, stirring for 16h, cooling to 40 ℃ after stirring, then adding cholesterol and dichloromethane after mixing, stirring uniformly, then adding N, N' -dicyclohexylcarbodiimide and 4-dimethylaminopyridine, and stirring and reacting for 24h at 40 ℃ to obtain a reaction solution B;

and step S32, mixing the reaction liquid B with four times of volume of absolute ethyl alcohol, separating out a precipitate, performing centrifugal separation, removing supernatant, washing the precipitate with the absolute ethyl alcohol, dissolving the washed precipitate with deionized water, adjusting the pH value to 7 with sodium hydroxide solution with the mass fraction of 4%, standing to remove insoluble substances, filling the obtained supernatant into a dialysis bag with the molecular weight cutoff of 14000 for dialysis for 3 days, concentrating by using a rotary evaporator, and performing freeze drying at-70 ℃ under vacuum to obtain the auxiliary agent.

Further, in step S31, the amount ratio of the modified sodium alginate to the dimethyl sulfoxide to the cholesterol to the dichloromethane to the N, N' -dicyclohexylcarbodiimide to the 4-dimethylaminopyridine is 5 g: 200mL of: 3.25 g: 15mL of: 2.64 g: 2.1 g.

Further, the modified sodium alginate is prepared by the following steps:

step S41, under the protection of nitrogen, adding 2, 6-xylenol, paraformaldehyde and n-heptane into a three-neck flask, setting the temperature at 90 ℃ and the rotation speed at 300r/min, stirring for 10min, then adding concentrated hydrochloric acid, keeping the temperature and the rotation speed unchanged, stirring for reacting for 12h, cooling the reaction liquid to room temperature, extracting the obtained reaction liquid for three times by using ethyl acetate and deionized water, combining organic phases, washing the organic phases to be neutral by using the deionized water, drying by using anhydrous sodium sulfate after the washing is finished, removing the ethyl acetate by rotary evaporation by using a rotary evaporator, and then drying in vacuum at 30 ℃ to constant weight to obtain an intermediate 1;

step S42, adding the intermediate 1, n-heptane and triphenylphosphine into a three-neck flask, stirring and reacting for 2h at the temperature of 80 ℃ and the rotating speed of 200r/min, cooling the reaction solution to room temperature after the stirring and reacting are finished, washing with petroleum ether, and drying in vacuum for 12h at the temperature of 30 ℃ after the washing is finished to obtain an intermediate 2; 2, 6-xylenol is used as a raw material to prepare an intermediate 2, the intermediate 2 is a quaternary phosphonium salt compound containing a hindered phenol structure, the intermediate 2 and sodium alginate generate ion exchange in a reaction manner to prepare the modified sodium alginate, the quaternary phosphonium salt structure in the modified sodium alginate has excellent antibacterial performance, a preservative is not required to be additionally added in the prepared skin care product, the components are milder, the hindered phenol structure of the modified sodium alginate can prevent the oxidative decomposition of the lecithin and the auxiliary agent, the storage stability of the antioxidant is improved, and the functions of vitamin C in the mild liquid cosmetic with the functions of whitening and improving the skin moisture are improved.

And step S43, mixing the intermediate 2 with deionized water, adding sodium alginate, stirring for 8-10h at the temperature of 50 ℃ and the rotating speed of 200r/min, washing with distilled water after the reaction is finished, and drying at the temperature of 40 ℃ to constant weight to obtain the modified sodium alginate.

Further, in step S41, the mass fraction of the concentrated hydrochloric acid is 37%, and the usage ratio of the 2, 6-xylenol, paraformaldehyde, n-heptane and concentrated hydrochloric acid is 2 g: 6 g: 5mL of: 16 mL; the dosage ratio of the intermediate 1, the n-heptane and the triphenylphosphine in the step S42 is 3 g: 2 g: 5 mL; in the step S43, the dosage ratio of the intermediate 2 to the deionized water to the sodium alginate is 1-3 g: 100mL of: 5-7 g.

The invention has the beneficial effects that:

the rose water contains moisturizing factor, can be fully absorbed by skin and can keep moisture, and the antioxidant mainly contains vitamin C, and can inhibit tyrosinase activity, thereby reducing melanin generation. Meanwhile, the vitamin C can also reduce the formed melanin into colorless melanin precursor by utilizing the strong antioxidation of the vitamin C, thereby improving the effect of skin darkness. The vitamin C has strong reducibility, is easy to oxidize and damage, loses the original reducibility, is generally coated by liposome, but the liposome is easy to oxidize and decompose and is not beneficial to storage, and the stability of the liposome is improved by modifying the sodium alginate, so that the antioxidation effect of the vitamin C is better exerted.

2, 6-xylenol is used as a raw material to prepare an intermediate 2, the intermediate 2 is a quaternary phosphonium salt compound containing a hindered phenol structure, the intermediate 2 and sodium alginate generate ion exchange in a reaction manner to prepare the modified sodium alginate, the quaternary phosphonium salt structure in the modified sodium alginate has excellent antibacterial performance, a preservative is not required to be additionally added in the prepared skin care product, the components are milder, the hindered phenol structure of the modified sodium alginate can prevent the oxidative decomposition of the lecithin and the auxiliary agent, the storage stability of the antioxidant is improved, and the functions of vitamin C in the mild liquid cosmetic with the functions of whitening and improving the skin moisture are improved.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

2 parts of grease, 800.1 parts of span, 6 parts of nutrient components, 0.2 part of antioxidant, 20 parts of natural plant extract, 100 parts of deionized water and 7 parts of humectant;

and thirdly, mixing the first component and the second component, adding a humectant, adjusting the pH value to 6 by using a pH regulator, standing and filtering to obtain the mild liquid cosmetic with the functions of whitening and improving skin moisture.

Wherein the natural plant extract is rose water.

Wherein the antioxidant is prepared by the following steps:

step S21, adding the egg acid ester, the auxiliary agent and the Tween-80 into absolute ethyl alcohol, setting the temperature at 25 ℃ and the rotating speed at 300r/min, stirring for 6min, transferring the obtained reaction solution into a rotary evaporator after stirring is finished, and performing reduced pressure evaporation for 50min at the temperature of 55 ℃ to obtain a mixture A;

and step S22, adding vitamin C into 0.05mol/L phosphate buffer solution for mixing, transferring the mixture into the mixture A after mixing, stirring for 15min at the temperature of 0 ℃ and the rotating speed of 200r/min, and after stirring is finished, performing ultrasonic dispersion for 20min at the frequency of 0 ℃ and 40kHz to obtain the antioxidant.

Wherein the dosage ratio of the egg acid ester, the auxiliary agent, the tween-80 and the absolute ethyl alcohol in the step S21 is 1 g: 0.4 g: 0.3 g: 50 mL; the dosage ratio of the vitamin C, the 0.05mol/L phosphate buffer solution and the mixture A in the step S22 is 0.3 g: 100mL of: 1g of the total weight of the composition.

The auxiliary agent is prepared by the following steps:

Wherein the dosage ratio of the modified sodium alginate, the dimethyl sulfoxide, the cholesterol, the dichloromethane, the N, N' -dicyclohexylcarbodiimide and the 4-dimethylaminopyridine in the step S31 is 5 g: 200mL of: 3.25 g: 15mL of: 2.64 g: 2.1 g.

The modified sodium alginate is prepared by the following steps:

step S42, adding the intermediate 1, n-heptane and triphenylphosphine into a three-neck flask, stirring and reacting for 2h at the temperature of 80 ℃ and the rotating speed of 200r/min, cooling the reaction solution to room temperature after the stirring and reacting are finished, washing with petroleum ether, and drying in vacuum for 12h at the temperature of 30 ℃ after the washing is finished to obtain an intermediate 2;

and step S43, mixing the intermediate 2 with deionized water, adding sodium alginate, stirring for 8 hours at the temperature of 50 ℃ and the rotating speed of 200r/min, washing with distilled water after the reaction is finished, and drying at the temperature of 40 ℃ to constant weight to obtain the modified sodium alginate.

Wherein, in the step S41, the mass fraction of the concentrated hydrochloric acid is 37%, and the dosage ratio of the 2, 6-xylenol, the paraformaldehyde, the n-heptane and the concentrated hydrochloric acid is 2 g: 6 g: 5mL of: 16 mL; the dosage ratio of the intermediate 1, the n-heptane and the triphenylphosphine in the step S42 is 3 g: 2 g: 5 mL; in the step S43, the dosage ratio of the intermediate 2 to the deionized water to the sodium alginate is 1 g: 100mL of: 5g of the total weight.

Example 2

7 parts of grease, 800.2 parts of span, 7 parts of nutrient components, 0.5 part of antioxidant, 25 parts of natural plant extract, 110 parts of deionized water and 8 parts of humectant;

Wherein the natural plant extract is rose water.

Wherein the antioxidant is prepared by the following steps:

step S21, adding the egg acid ester, the auxiliary agent and the Tween-80 into absolute ethyl alcohol, setting the temperature at 25 ℃ and the rotating speed at 300r/min, stirring for 8min, transferring the obtained reaction solution into a rotary evaporator after stirring is finished, and performing reduced pressure evaporation for 50min at the temperature of 55 ℃ to obtain a mixture A;

and step S22, adding vitamin C into 0.05mol/L phosphate buffer solution for mixing, transferring the mixture into the mixture A after mixing, stirring for 18min at the temperature of 2 ℃ and the rotating speed of 200r/min, and after stirring is finished, performing ultrasonic dispersion for 20min at the frequency of 2 ℃ and 40kHz to obtain the antioxidant.

Wherein the dosage ratio of the egg acid ester, the auxiliary agent, the tween-80 and the absolute ethyl alcohol in the step S21 is 1 g: 0.6 g: 0.3 g: 50 mL; the dosage ratio of the vitamin C, the 0.05mol/L phosphate buffer solution and the mixture A in the step S22 is 0.3 g: 100mL of: 1.5 g.

The auxiliary agent is prepared by the following steps:

The modified sodium alginate is prepared by the following steps:

and step S43, mixing the intermediate 2 with deionized water, adding sodium alginate, stirring for 9 hours at the temperature of 50 ℃ and the rotating speed of 200r/min, washing with distilled water after the reaction is finished, and drying at the temperature of 40 ℃ to constant weight to obtain the modified sodium alginate.

Wherein, in the step S41, the mass fraction of the concentrated hydrochloric acid is 37%, and the dosage ratio of the 2, 6-xylenol, the paraformaldehyde, the n-heptane and the concentrated hydrochloric acid is 2 g: 6 g: 5mL of: 16 mL; the dosage ratio of the intermediate 1, the n-heptane and the triphenylphosphine in the step S42 is 3 g: 2 g: 5 mL; in the step S43, the dosage ratio of the intermediate 2 to the deionized water to the sodium alginate is 2 g: 100mL of: 6 g.

Example 3

12 parts of grease, 800.3 parts of span, 8 parts of nutrient components, 0.8 part of antioxidant, 30 parts of natural plant extract, 120 parts of deionized water and 9 parts of humectant;

and thirdly, mixing the first component and the second component, adding a humectant, adjusting the pH value to 6.5 by using a pH regulator, standing and filtering to obtain the mild liquid cosmetic with the functions of whitening and improving skin moisture.

Wherein the natural plant extract is rose water.

Wherein the antioxidant is prepared by the following steps:

step S21, adding the egg acid ester, the auxiliary agent and the Tween-80 into absolute ethyl alcohol, setting the temperature at 25 ℃ and the rotating speed at 300r/min, stirring for 10min, transferring the obtained reaction solution into a rotary evaporator after stirring is finished, and performing reduced pressure evaporation for 50min at the temperature of 55 ℃ to obtain a mixture A;

and step S22, adding vitamin C into 0.05mol/L phosphate buffer solution for mixing, transferring the mixture into the mixture A after mixing, stirring for 20min at the temperature of 5 ℃ and the rotating speed of 200r/min, and after stirring is finished, performing ultrasonic dispersion for 20min at the frequency of 5 ℃ and 40kHz to obtain the antioxidant.

Wherein the dosage ratio of the egg acid ester, the auxiliary agent, the tween-80 and the absolute ethyl alcohol in the step S21 is 1 g: 0.8 g: 0.3 g: 50 mL; the dosage ratio of the vitamin C, the 0.05mol/L phosphate buffer solution and the mixture A in the step S22 is 0.3 g: 100mL of: 2g of the total weight.

The auxiliary agent is prepared by the following steps:

The modified sodium alginate is prepared by the following steps:

and step S43, mixing the intermediate 2 with deionized water, adding sodium alginate, stirring for 10 hours at the temperature of 50 ℃ and the rotating speed of 200r/min, washing with distilled water after the reaction is finished, and drying at the temperature of 40 ℃ to constant weight to obtain the modified sodium alginate.

Wherein, in the step S41, the mass fraction of the concentrated hydrochloric acid is 37%, and the dosage ratio of the 2, 6-xylenol, the paraformaldehyde, the n-heptane and the concentrated hydrochloric acid is 2 g: 6 g: 5mL of: 16 mL; the dosage ratio of the intermediate 1, the n-heptane and the triphenylphosphine in the step S42 is 3 g: 2 g: 5 mL; in the step S43, the dosage ratio of the intermediate 2 to the deionized water to the sodium alginate is 3 g: 100mL of: 7 g.

Comparative example 1

The antioxidant of example 1 was replaced with vitamin C, and the remaining raw materials and preparation process were kept unchanged.

The cosmetics prepared in examples 1-3 were tested for preservative performance and the results were found to be acceptable in a single challenge preservative test using the classic 28 day preservative challenge recommended by the American society for cosmetics, toiletries and fragrances (CTFA) with reference to the efficacy evaluation method of preservative systems recommended by the CTFA.

The cosmetics of examples 1 to 3 and comparative example 1 were subjected to a performance test, 100 persons of 20 to 30 years old were divided into 5 groups, each group was equal in number of men and women and age, and were tried continuously for 30 days, the melanin content in the skin was examined with a skin melanin tester, the moisture content was measured with a skin moisture test probe, and the effect on the skin was evaluated by comparative analysis;

the melanin change rate is the skin melanin content measured after the sample is smeared/the skin melanin content measured before the sample is smeared multiplied by 100 percent; moisture content is the skin moisture content measured after application of the sample/moisture content measured before application of the sample x 100%. The test results are all mean values.

The test results are shown in table 1 below:

TABLE 1

From the above table 1, it can be seen that the mild liquid cosmetic with skin whitening and moisture improving effects prepared by the present invention has significant skin whitening and moisture improving effects.

In the description herein, references to the description of "one embodiment," "an example," "a specific example" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The foregoing is illustrative and explanatory only and is not intended to be exhaustive or to limit the invention to the precise embodiments described, and various modifications, additions, and substitutions may be made by those skilled in the art without departing from the scope of the invention or exceeding the scope of the claims.

Claims

1. A mild liquid cosmetic with whitening and skin moisture improving functions is characterized by comprising the following raw materials in parts by weight:

thirdly, mixing the first component and the second component, adding a humectant, adjusting the pH value to 6-6.5 by using a pH regulator, standing and filtering to obtain the mild liquid cosmetic with the functions of whitening and improving skin moisture;

the antioxidant is prepared by the following steps:

2. A mild liquid cosmetic with whitening and skin moisture improving effects as claimed in claim 1, wherein the oil is one or two of olive oil and jojoba oil mixed at any ratio; the humectant is one or more of sodium hyaluronate, trimethylglycine, methylglycine proline and xylitol glucoside which are mixed according to any proportion; the pH regulator is citric acid-sodium citrate; the nutrient component is small molecular polypeptide.

3. The mild liquid cosmetic with whitening and skin moisture improving effects according to claim 1, wherein the natural plant extract is rose water.

4. The mild liquid cosmetic with whitening and skin moisture improving effects as claimed in claim 1, wherein the auxiliary is prepared by the steps of:

step S31, adding modified sodium alginate into a round-bottom flask, adding dimethyl sulfoxide, setting the temperature to be 50 ℃, stirring for 16 hours, cooling to 40 ℃ after stirring is finished, then mixing cholesterol and dichloromethane, adding, uniformly stirring, then adding N, N' -dicyclohexylcarbodiimide and 4-dimethylaminopyridine, and stirring and reacting for 24 hours at 40 ℃ to obtain a reaction solution B;

5. The mild liquid cosmetic with whitening and skin moisture improving effects according to claim 4, wherein the modified sodium alginate is prepared by the following steps:

step S41, under the protection of nitrogen, adding 2, 6-xylenol, paraformaldehyde and n-heptane into a three-neck flask, setting the temperature to 90 ℃, stirring for 10min, then adding concentrated hydrochloric acid, keeping the temperature and the rotating speed unchanged, stirring for reaction for 12h, cooling the reaction liquid to room temperature, extracting the obtained reaction liquid for three times by using ethyl acetate and deionized water, combining organic phases, washing the organic phases to be neutral by using the deionized water, drying by using anhydrous sodium sulfate after the washing is finished, removing the ethyl acetate by using a rotary evaporator through rotary evaporation, and then drying in vacuum at 30 ℃ to constant weight to obtain an intermediate 1;

step S42, adding the intermediate 1, n-heptane and triphenylphosphine into a three-neck flask, stirring and reacting for 2h at the temperature of 80 ℃, cooling the reaction liquid to room temperature after the stirring and reacting are finished, washing with petroleum ether, and drying in vacuum for 12h at the temperature of 30 ℃ after the washing is finished to obtain an intermediate 2;

and step S43, mixing the intermediate 2 with deionized water, adding sodium alginate, stirring at 50 ℃ for 8-10h, washing with distilled water after the reaction is finished, and drying at 40 ℃ to constant weight to obtain the modified sodium alginate.