Chitosan sunscreen skin care composition and preparation method thereof

Abstract

The present invention separates and purifies chitosan in shrimp by-products, and then prepares chitosan / collagen / plant essential oil multilayer nano composite microsphere emulsion, which is applied to sunscreen skin care products. The plant essential oil has sunscreen effect, chitosan has antibacterial and anti-inflammatory properties, and collagen can repair damaged skin. By controlling the extraction and purification process of chitosan, the molecular weight of chitosan is controlled, the homogeneity of chitosan is improved, and the antibacterial property of chitosan is improved. Through the form of multilayer nano composite microsphere emulsion, the plant essential oil is protected, the volatilization of the plant essential oil is reduced; the release rate of the plant essential oil is controlled, and a slow release effect is produced; the particle size of the effective ingredient is smaller and easier to be absorbed by the skin; at the same time, a component with waterproof performance is added to the sunscreen cosmetics, so that the sunscreen skin care products of the present invention have excellent sunscreen effect and waterproof performance.

Description

Technical Field

[0001] The invention relates to the field of cosmetics, and in particular to a chitosan sunscreen and skin care composition, and a method for preparing the sunscreen and skin care composition. Background Art

[0002] There is a large amount of chitosan in marine arthropods such as shrimps, crabs, insects, fungi, algae, as well as mollusks and higher plants. Chitosan is widely distributed in nature, and its reserves are only second to cellulose. It is the second largest natural polymer and a recyclable renewable resource that is inexhaustible. White shrimp farming is one of the main components of aquaculture. In the shrimp processing industry, a large amount of shrimp by-products are produced, such as shrimp heads, shrimp shells and shrimp tails, which are rich in chitosan resources. However, most shrimp by-products are still in the primary processing stage, lacking high-value development and utilization, which not only leads to waste of resources, but also causes environmental pollution.

[0003] Chitosan is obtained after deacetylation of chitin. Chitosan is a chain polymer compound formed by monomers connected by β-1,4-glycosidic bonds. Chitosan is one of the few natural cationic polymers and has a wide range of applications in many fields due to its unique functions. It has excellent biocompatibility, film-forming properties, moisturizing, anti-wrinkle, whitening, hair softening and hair care effects, and is widely used in the field of skin care products due to its safety, non-irritation and non-toxicity to the skin.

[0004] Sunscreen products are commonly used skin care products in people's daily lives. The main active ingredients of sunscreen products on the market are physical sunscreens, chemical sunscreens and natural sunscreens. Physical sunscreens are essentially very fine particles made of opaque substances, which can reflect or scatter ultraviolet rays so that they cannot enter the skin and can protect against UVA and UVB in a broad spectrum. They mainly include titanium dioxide, zinc oxide, talc, magnesium oxide, calcium carbonate and white clay. Their disadvantages are that they are thick and heavy, and they tend to turn white when applied on the face, which is unnatural, and they tend to clog pores, affect the normal secretion of sebaceous glands and sweat glands, and they tend to fall off and cause acne. Chemical sunscreens are absorbers of ultraviolet rays, which can absorb ultraviolet rays and attenuate their energy so that they cannot reach the skin. Their disadvantages are that they are somewhat irritating and can easily cause allergies. Natural sunscreens are some natural ingredients from nature, such as plant flavonoids, phenylpropanoids, polyphenols, carotenoids and other secondary metabolites, which have benzene rings or conjugated structures, can absorb ultraviolet rays, and also have antioxidant, anti-inflammatory, anti-aging or repair effects. Natural sunscreen ingredients are generally derived from plants, and they have a high safety and green index. In addition to plant extracts, many plant essential oils also have good sunscreen effects. However, since plant essential oils are highly volatile, they may evaporate or deteriorate quickly when used in cosmetics, and only a small part of them can be absorbed and utilized, reducing their sunscreen and skin care effects in cosmetics.

[0005] Therefore, it is necessary to develop a sunscreen skin care product that can effectively utilize chitosan in shrimp by-products and simultaneously improve the sunscreen skin care effect. Summary of the invention

[0006] In order to solve the above problems, the present invention provides a chitosan sunscreen skin care composition and a preparation method thereof. Soluble chitosan (i.e., chitosan) is prepared by extracting chitosan from shrimp by-products and applied to sunscreen skin care products. The chitosan is mainly in the form of a multi-layer nano-composite microsphere emulsion to protect plant essential oils and reduce the volatilization of essential oils. At the same time, the sustained-release function is enhanced, thereby improving the sunscreen skin care effect.

[0007] The specific steps are as follows:

[0008] S1 Dispersed Collagen

[0009] Accurately weigh a certain amount of collagen and disperse it in an acetic acid solution with a mass fraction of 1% to 3%. After stirring at room temperature until completely dissolved, continue stirring for 10 to 15 minutes to evenly disperse the collagen in the acetic acid solution to obtain a collagen solution.

[0010] S2 collagen wrapped with plant essential oil

[0011] Accurately measure the prepared collagen solution and natural plant essential oil with sunscreen effect and add them into a beaker in a volume ratio of 5:1-10:1, and disperse them with a high-speed disperser at a speed of 10000-15000 r / min for 3-5 minutes. Take the upper white emulsion and wash it with deionized water until it is neutral to obtain collagen / plant essential oil microsphere A emulsion.

[0012] S3 Dispersed Chitosan

[0013] Accurately weigh a certain amount of chitosan and disperse it in an acetic acid solution with a mass fraction of 1% to 3%. After stirring at room temperature until it is completely dissolved, continue stirring for 10 to 15 minutes to evenly disperse the chitosan in the acetic acid solution to obtain a chitosan solution.

[0014] S4 Chitosan Encapsulated Microspheres A Emulsion

[0015] Accurately measure the prepared collagen / plant essential oil microsphere A emulsion and chitosan solution in a volume ratio of 5:5 to 1:5, add them into a beaker and stir evenly, use a high-speed disperser to disperse at a speed of 10000 to 15000 r / min for 3 to 5 minutes, take the upper white emulsion and wash it with deionized water until it is neutral to obtain chitosan / collagen / plant essential oil multilayer nanocomposite microsphere B emulsion.

[0016] S5 added oil wax ingredients

[0017] Accurately weigh a certain amount of natural vegetable oil and natural vegetable wax, add them into a beaker, heat in a water bath at 75-85°C and stir evenly until completely melted to obtain solution C.

[0018] S6 adds various ingredients

[0019] Accurately weigh a certain amount of natural moisturizer and add it to deionized water, and stir it evenly at room temperature until it is completely dissolved; then add natural plant extracts, natural antioxidants, and natural preservatives therein, and stir it evenly at room temperature until it is completely dissolved, to obtain solution D;

[0020] S7 Emulsification

[0021] Accurately weigh a certain amount of natural emulsifier and add it to deionized water, and stir it evenly at room temperature until it is completely dissolved; then add chitosan / collagen / plant essential oil multilayer nanocomposite microsphere B emulsion, solution C, solution D, and the remaining water, and stir it evenly at room temperature until it is completely emulsified, so as to obtain a sunscreen skin care product with uniform texture, delicate application, smooth skin feel, refreshing and non-greasy, excellent sunscreen effect and waterproof properties.

[0022] In step S1, collagen is dissolved in acetic acid solution. The reasons for choosing acetic acid solution to dissolve collagen are as follows: First, acetic acid solution is used to dissolve collagen, taking advantage of the fact that collagen is easily soluble in acidic solution; second, the property that acetic acid solution is miscible with deionized water is used to create conditions for using deionized water to wash and remove acetic acid in step S2.

[0023] Based on the same principle, in step S3, chitosan is dissolved in acetic acid solution. The reason why acetic acid solution is chosen to dissolve chitosan is mainly due to the following reasons. First, the chitosan is easily soluble in acidic solution, and acetic acid solution is used to dissolve chitosan; second, the acetic acid solution and deionized water are mutually soluble, which creates conditions for washing with deionized water to remove acetic acid in step S4.

[0024] In step S2, by controlling the ratio of collagen solution: natural plant essential oil, the speed of the disperser, the dispersion time and other parameters, the collagen is wrapped around the plant essential oil to form a collagen / plant essential oil microsphere A emulsion with a microsphere structure with the plant essential oil as the inner core and collagen as the spherical shell.

[0025] In step S4, by controlling the ratio of microsphere A emulsion: chitosan solution, the speed of the disperser, the dispersion time and other parameters, the chitosan is wrapped around the microsphere A emulsion to form a chitosan / collagen / plant essential oil multilayer nanocomposite microsphere B emulsion with a microsphere structure having one or more microspheres A as the inner core and chitosan as the spherical shell.

[0026] Preferably, the skin care product includes 10% to 25% by mass of chitosan / collagen / plant essential oil multilayer nanocomposite microsphere B emulsion, 4% to 6% by mass of natural plant oil, 5% to 6% by mass of natural plant wax, 5% to 7% by mass of natural moisturizer, 3% to 5% by mass of natural plant extract, 3% to 6% by mass of natural antioxidant, 3% to 5% by mass of natural preservative, 1.5% to 2% by mass of natural emulsifier, and the remainder is water.

[0027] The collagen in the skin care products has multiple benefits in skin care, making collagen a key ingredient in many skin care products and cosmetics, helping to keep the skin healthy, young and beautiful.

[0028] (1) Moisturizing effect. Collagen contains natural moisturizing factors that can form a protective layer on the skin surface, lock in moisture, and keep the skin hydrated.

[0029] (2) Anti-wrinkle effect. Collagen also has anti-wrinkle and skin firming effects. By increasing the firmness and elasticity of the skin, collagen helps reduce wrinkles, improve skin elasticity, and make the skin firmer.

[0030] (3) Whitening effect. The tyrosine residues in collagen can inhibit the formation of melanin, thereby helping to whiten the skin.

[0031] (4) Nutritional effect. Collagen provides essential nutrition for the skin, enhances the activity of original collagen, improves the living environment of cells and promotes metabolism.

[0032] (5) Anti-aging and sun protection effects. It can effectively protect the skin from ultraviolet damage and delay skin aging.

[0033] (6) Skin repairing effect: Collagen can promote the metabolism of skin cells and help repair damaged skin and tissues.

[0034] Preferably, the natural plant essential oil with sunscreen effect is any one or more mixtures of carrot seed essential oil, myrrh essential oil, chamomile essential oil and lavender essential oil.

[0035] Carrot seed essential oil is a natural essential oil extracted from carrot seeds by pressing or distillation, and has multiple benefits in skin care.

[0036] (1) Antioxidant effect. Carrot seed essential oil is rich in antioxidants, such as β-carotene, vitamin E, flavonoids, sesquiterpenoids, carotene alcohols and carotene alcohols, which can neutralize free radicals, reduce the damage of oxidative stress to cells, and protect the health of cells and tissues.

[0037] (2) Skin repairing effect: Promote cell and tissue regeneration, repair the basal layer of the skin, and accelerate scar healing.

[0038] (3) Anti-aging effect.

[0039] (4) Moisturizing effect, improving skin elasticity and radiance.

[0040] (5) Analgesic and anti-inflammatory effects.

[0041] (6) Sun protection: Helps block ultraviolet rays and prevents the formation of dark spots or sun spots.

[0042] (7) Nutritional effect. Carrot seed essential oil is rich in vitamin A, which promotes the production of collagen and reduces skin dryness and fine lines.

[0043] (8) Regulatory effect. Monoterpene alcohols and esters can regulate hormone secretion, adjust women's body functions, and restore disordered body rhythms.

[0044] Myrrh essential oil is known as the "essential oil for moisturizing and nourishing the skin". It is extracted from the distilled resin of the myrrh tree. It has a strong aroma and multiple medicinal properties, and has multiple functions in skin care.

[0045] (1) Antibacterial, anti-inflammatory and anti-allergic effects.

[0046] (2) It has the functions of astringency, analgesia, and stimulation of wound healing. It is called "natural band-aid".

[0047] (3) Antioxidant and anti-aging effects. It can help tighten the skin, reduce dryness, aging, roughness, wrinkles, and restore skin elasticity and radiance.

[0048] (4) Sun protection effect.

[0049] Chamomile essential oil is a natural essential oil extracted from the chamomile plant. It has multiple effects such as anti-inflammatory, anti-allergic, antibacterial, healing, and moisturizing. It can be used to treat minor skin infections or wounds, helping to promote wound healing and reduce the risk of infection. Chamomile essential oil can cool sunburned skin, calm and reduce inflammation, neutralize allergies and enhance skin regeneration. It has a good soothing effect on skin pain and muscle spasms caused by sunburn.

[0050] Lavender essential oil is extracted from lavender. It can clear away heat and detoxify, cleanse the skin, control oil content, remove freckles and whiten the skin, remove wrinkles and tender skin, remove eye bags and dark circles, and promote the regeneration of damaged tissues. Lavender essential oil not only has sunscreen effects, but also can reduce inflammation, relieve pain, and moisturize the skin after sun exposure, promote the repair and regeneration of sunburned skin cells, and avoid leaving scars. It is known as the "skin first aid oil".

[0051] Preferably, the natural plant oil with sunscreen effect is any one or more mixtures of camellia oil, wood wax oil, sesame oil and avocado oil.

[0052] Camellia oil, also known as tea seed oil, is taken from the seeds of the tea tree of the Theaceae family of the Camellia genus. It is a natural plant oil with multiple benefits in skin care.

[0053] (1) Antioxidant effect. Camellia oil is rich in fatty acids (93% unsaturated fatty acids, including 82% oleic acid and 11% linoleic acid), camellia glycosides, tea polyphenols, saponins, tannins, and antioxidants, and has a strong antioxidant effect.

[0054] (2) Moisturizing effect. Camellia oil has a relatively fine molecular structure and is absorbed quickly after use. Camellia oil can form a protective film on the skin surface, which has a moisturizing effect and is helpful in preventing and improving dry skin.

[0055] (3) Sun protection. The protective film can also isolate the skin from ultraviolet rays to a certain extent, reducing the irritation and damage of ultraviolet rays to the skin, and has a sun protection effect.

[0056] (4) Anti-inflammatory and anti-cancer effects. Camellia oil is rich in squalene, which has anti-inflammatory effects. Squalene and flavonoids have certain effects on anti-cancer.

[0057] (5) Nutritional effect. Camellia oil is rich in nutrients such as vitamin D and vitamin A. Proper use can provide certain nutrients to the skin, help enhance skin elasticity, and prevent fine wrinkles on the skin surface.

[0058] Wood wax oil is a natural oil extracted from tree wax and has many benefits in skin care.

[0059] (1) Moisturizing effect. The main components of wood wax oil are cerotic acid, oleic acid, linoleic acid, etc. It is used for skin care and has good lubricating, antiseptic, waterproof and moisturizing effects.

[0060] (2) Anti-inflammatory effect: Wood wax oil has the characteristics of fragrance, strong volatility, bactericidal and disinfectant.

[0061] (3) Sun protection effect. Some components in wood wax oil have a certain ability to absorb ultraviolet rays and have certain sun protection properties.

[0062] (4) Repairing effect. Wood wax oil can increase the consistency and lubricity of cosmetics. It also has good absorption, which helps it penetrate deep into the skin, protecting, repairing and moisturizing the skin.

[0063] (5) Moisturizing effect. Wood wax oil has good emollient and glossy properties, which can improve the uniformity and softness of makeup.

[0064] Sesame oil is a vegetable oil extracted from the mature seeds of Sesame, a plant of the Sesame family. It has many benefits in skin care. The main ingredients are unsaturated fatty acids, oleic acid, linoleic acid, natural antioxidant sesame acid, as well as protein, sesamin, vitamin E, lecithin, sucrose, calcium, phosphorus, iron and other minerals. It is a very nutritious vegetable oil.

[0065] (1) Anti-aging effect. Vitamin E has the function of promoting cell division and delaying aging.

[0066] (2) Moisturizing effect. Unsaturated fatty acids can penetrate the skin to form a protective film, preventing water loss, thereby keeping the skin soft, smooth and elastic, and exerting moisturizing and nourishing functions.

[0067] (3) Antioxidant effect. Antioxidants can resist the effects of free radicals, delay skin aging, and improve dry and rough skin problems.

[0068] (4) Anti-inflammatory effect. Sesame oil also has anti-inflammatory and bactericidal properties, which can help treat skin inflammation and infection, improve the skin's resistance, and fight against the invasion of harmful substances from the outside world.

[0069] (5) Whitening and sun protection effect. Sesame oil can also inhibit the production of melanin, help fade spots and acne marks, and improve skin quality. Sesame oil has a sun protection effect and can be used as a natural sunscreen to effectively block the damage of sunlight ultraviolet rays to the skin.

[0070] Avocado oil, also known as alligator pear oil, is extracted from the dried fruit by pressing and has many benefits in skin care.

[0071] (1) Moisturizing effect. Avocado oil is rich in nutrients, has a heavy texture, good permeability, can improve skin elasticity, and has moisturizing oil properties. It is very suitable for dry skin, sensitive skin, dehydrated skin, and eczema skin. Because it is rich in vitamin D, it is suitable for dry, fragile, sun-exposed, swollen skin, and increases skin elasticity, dehydrated and inelastic skin.

[0072] (2) Cleansing effect. It can also be used as a cleansing milk, which has a good deep cleansing effect and is very effective in metabolism, fading dark spots, and eliminating wrinkles.

[0073] (3) Antioxidant effect. Avocado oil is rich in vitamins A, E, and C, which can effectively improve dryness and aging of the skin and is a very good natural antioxidant.

[0074] (4) Sun protection. The rich vitamins and fatty acids in avocado oil can soothe and protect the skin from sunburn. It can also help the skin increase its resistance, moisturize and penetrate easily, and have anti-aging effects. In addition, lutein and zeaxanthin can protect the skin from damage by ultraviolet rays and radiation.

[0075] Preferably, the natural plant wax is any one or more mixtures of rice bran wax, sugarcane wax, sunflower seed wax and laurel wax.

[0076] Among them, rice bran wax is an important by-product of rice oil processing. It is a natural wax extracted from the rice bran on the outer layer of rice and has multiple functions in skin care.

[0077] (1) Moisturizing effect. Rice bran wax is mainly composed of esters of higher fatty alcohols and higher fatty acids. It has excellent moisturizing properties and can help the skin lock in moisture, making the skin softer and smoother. Rice bran wax also has good lubricity and waterproof properties, which can enhance the durability and water resistance of cosmetics.

[0078] (2) Synergistic antioxidant effect. Since rice bran wax itself has multiple functions, it can be combined with other ingredients to further enhance the effect of cosmetics. For example, when combined with antioxidant ingredients such as vitamin E, it can provide better antioxidant protection and slow down the aging of the skin.

[0079] (3) Synergistic moisturizing effect. In addition, when combined with moisturizing ingredients such as hyaluronic acid, it can create an ideal moisturizing effect and provide long-term moisture to the skin.

[0080] (4) Immune effect. Rice bran wax also has biological activity in promoting cell vitality, immune enhancement and anti-wrinkle.

[0081] Sugarcane wax, also known as sugarcane wax, is originally attached to the outer layer of sugarcane peel and is a by-product of the sugar industry. The main component of sugarcane wax is esters composed of 16-carbon fatty acids and 30-carbon fatty alcohols or stigmasterols. It is rich in plant sterols and natural higher alkanol mixtures, and has anti-inflammatory and anti-aging effects.

[0082] Sunflower seed wax is a natural plant wax extracted from sunflower seeds and has many benefits in skin care.

[0083] (1) Thickening and emulsifying effects. As a lubricant, thickener, emulsifier, etc., it can improve the consistency, adhesion and emulsification of cosmetics, improve its gloss effect, improve the texture and feel of cosmetics, and bring a better user experience.

[0084] (2) Waterproof effect. Prevent oil and sweat from washing away and removing cosmetics, thus increasing their service life and making them last longer.

[0085] (3) Moisturizing effect. Sunflower seed wax also has good moisturizing properties. It can effectively lock in moisture, prevent skin from drying out, and keep the skin moist and smooth.

[0086] Bay wax is a wax extracted from bay leaves and has many functions.

[0087] (1) Antibacterial effect. Laurel wax has good antibacterial effect and can effectively kill bacteria and fungi. It is of great significance for the prevention and treatment of skin diseases.

[0088] (2) Antioxidant effect. Laurel wax is rich in antioxidant ingredients, which can reduce the damage caused by free radicals to cells and have anti-aging effects.

[0089] (3) Repairing effect. Laurel wax has good tissue repair ability, can promote the regeneration and repair of skin cells, and has a positive effect on the prevention and treatment of scars.

[0090] (4) Waterproof effect. Laurel wax has good waterproof properties and can be used in cosmetics to improve the waterproofness of cosmetics.

[0091] Preferably, the natural moisturizing agent is any one or more mixtures of glycerol glucoside, hydrolyzed collagen, and urea.

[0092] Among them, glyceryl glucoside is a glycoside compound formed by glucose and glycerol connected by glycosidic bonds, which has multiple functions in skin care.

[0093] (1) Protective effect. With good ecological safety, compatibility and surface activity, it can protect cells from damage caused by harsh environments such as high osmotic pressure, high temperature, drought and ultraviolet rays. It improves the skin barrier, helps the skin retain moisture, locks the skin's moisture factor, adds a protective layer to the skin, and plays an important role in protecting the skin layer.

[0094] (2) Moisturizing effect. Due to its low water absorption and high moisturizing properties, glyceryl glucoside can be used as a cosmetic raw material to improve the moisturizing effect of the skin. It has a unique moisturizing effect. It can lock water for cells due to its polyhydroxy structure and increase the expression of aquaporin AQP3 to deeply moisturize cells. It can also penetrate into the dermis to achieve long-term moisturizing. It can also eliminate the tightness of the skin after cleansing, promote the skin's moisture factor, balance the skin's water and oil balance, replenish the skin's lack of moisture, and increase the skin's moisturizing, elasticity, smoothness and thickness.

[0095] (3) Pharmacological effects. Glyceryl glucoside has excellent transdermal properties and a small molecular weight. It can penetrate into the dermis efficiently and has high pharmacological activity and skin care value. It can act as a cell activator in cosmetics and has antioxidant, anti-aging and cell repair effects. It can powerfully activate cells and promote cell regeneration; enhance cell vitality and accelerate the process of cell metabolism; stimulate skin cells to regenerate; enhance the antioxidant capacity of epidermal cells (SOD); and accelerate the synthesis of type I collagen precursor in aging cells.

[0096] (4) Anti-inflammatory effect. Glyceryl glucoside can also reduce the production of inflammatory bacterial factors, achieve anti-inflammatory effects, help repair skin tissue layers, and accelerate wound healing.

[0097] (5) Antioxidant effect. Glyceryl glucoside can effectively cut off collagenase and is a strong antioxidant that can remove skin free radicals, enhance skin metabolism, accelerate the production of collagen in aging cells, repair the skin, delay aging, and whiten the skin.

[0098] In short, glyceryl glucoside has the effects of moisturizing, whitening, repairing, anti-oxidation, anti-aging, anti-inflammatory and anti-allergic. It can not only moisturize, protect the stratum corneum, and resist ultraviolet rays, but also repair cells, inhibit the formation of cytokine SCF, prevent inflammation, enhance skin elasticity, prevent skin redness, rash, and reduce crow's feet.

[0099] Hydrolyzed collagen has many benefits in skin care.

[0100] (1) Moisturizing effect. It has the effects of moisturizing, brightening skin tone, tightening skin, fading fine lines and repairing damaged skin tissue. Hydrolyzed collagen is rich in hydrophilic natural moisturizing factors, which can strongly lock in moisture and relieve dry skin. The increase in water content affects the glossiness of the skin. The good water retention capacity of hydrolyzed collagen can keep the skin moisturized and shiny, and has the effect of brightening the skin tone.

[0101] (2) Skin firming effect. After being absorbed by the skin, hydrolyzed collagen can fill the space between the skin and the dermis, increasing the skin's firmness and elasticity. Due to its rich water content and firming effect, hydrolyzed collagen helps to reduce facial fine lines and wrinkles.

[0102] (3) Repairing effect. Repairing damaged skin tissue. Hydrolyzed collagen can penetrate into the bottom layer of the skin, help cells grow normally, and repair damaged skin tissue.

[0103] (4) Antioxidant effect. In addition, hydrolyzed collagen also has an antioxidant effect, which can remove free radicals and slow down the aging process;

[0104] Urea has many benefits in skin care.

[0105] (1) Moisturizing effect. Urea is a very useful moisturizing ingredient. It exists in the stratum corneum of the skin and is the main component of the skin's natural moisturizing factor (NMF). It helps to maintain the moisture and nourishment of the skin, can reduce the loss of moisture in the skin, and enhance the skin's barrier function, especially under low humidity conditions.

[0106] (2) Exfoliation. Urea has the effect of softening keratin, helping to soften and remove dead skin cells, preventing the stratum corneum from blocking pores, promoting the generation of new cells, improving skin texture, and thereby improving acne problems.

[0107] (3) Antibacterial effect. Urea also has antibacterial and antipruritic effects, helping to reduce the growth of harmful microorganisms on the skin surface.

[0108] Preferably, the natural plant extract with sunscreen effect is any one of green tea extract, licorice extract, olive leaf extract, safflower extract, lavender extract or a mixture thereof.

[0109] Among them, green tea extract is the active ingredient extracted from green tea leaves, mainly including tea polyphenols (catechins), caffeine, aromatic oils, water, minerals, pigments, carbohydrates, proteins, amino acids, vitamins, etc., and has multiple functions in skin care.

[0110] (1) Antioxidant effect. Green tea extract can scavenge free radicals and inhibit lipid peroxidation, thus having anti-aging effects.

[0111] (2) Sun protection effect. Studies have shown that green tea extract can inhibit UV-induced skin damage and reduce skin redness, swelling and pigmentation.

[0112] (3) Anti-inflammatory effect. As an excellent additive for cosmetics and daily chemicals, it has strong antibacterial and enzyme inhibitory effects. Therefore, it can prevent and treat skin diseases, skin allergies, remove skin pigments, prevent tooth decay, dental plaque, periodontitis and bad breath, etc.

[0113] Licorice extract has a variety of benefits in skin care.

[0114] (1) Antioxidant and anti-inflammatory effects. Glycyrrhizic acid in licorice extract has antioxidant and anti-inflammatory effects, which can repair damaged skin and reduce pigmentation.

[0115] (2) Sun protection. Licorice extract can also reduce the stimulation of ultraviolet rays on the skin and keep the skin healthy. Olive leaf extract has multiple effects in skin care.

[0116] (1) Anti-inflammatory effect. Olive leaf extract has anti-inflammatory and antibacterial effects. It contains oleuropein, which can resist inflammation and promote wound healing.

[0117] (2) Antioxidant effect. Oleuropein in olive leaf extract can inhibit the production of free radicals, stimulate fibroblasts, promote fibroblasts to synthesize collagen, reduce wrinkles, and play an anti-aging role.

[0118] (3) Sun protection effect. Oleuropein can also prevent ultraviolet rays from breaking down skin membrane lipids, protecting skin cells from damage by ultraviolet rays.

[0119] Safflower extract has many functions in skin care. It has the functions of promoting blood circulation, anti-inflammation, and anti-oxidation. It improves skin blood circulation, promotes skin metabolism, removes free radicals, inhibits melanin deposition, accelerates the removal of spots and decolorization, absorbs ultraviolet rays, etc., and has the functions of whitening, sun protection, and anti-aging. It also has a therapeutic effect on contact dermatitis, seborrheic dermatitis, pruritus, and neurodermatitis.

[0120] Lavender extract has a variety of benefits in skin care.

[0121] (1) Sunscreen and antioxidant effects. Lavender extract is rich in polyphenols and flavonoids, which are natural antioxidants that can effectively fight the damage of ultraviolet radiation to the skin and have excellent ultraviolet protection effects. Therefore, adding lavender extract to skin care products can provide additional ultraviolet protection and effectively prevent skin aging and pigmentation.

[0122] (2) Antibacterial effect. Lavender extract contains a natural substance called lavandulone, which has a strong antibacterial effect. Therefore, lavender extract can be used as a natural antibacterial agent in skin care products to remove bacteria and dirt on the skin surface, and prevent and relieve the occurrence of skin inflammation problems such as acne.

[0123] (3) Astringent effect. Lavender extract also has an astringent effect, which can effectively shrink pores and reduce oil secretion, thereby preventing skin problems such as acne.

[0124] (4) Repairing effect. Lavender extract also contains a lot of alcohols and acids, which can quickly penetrate into the deep layers of the skin, promote the division and repair of skin cells, and thus accelerate the healing speed of the skin during the recovery period. Especially in terms of reducing scars, the effect of lavender extract is very significant. By deeply nourishing and promoting skin cell renewal, the skin can be restored to a smoother, firmer and more elastic state. Lavender extract can also help improve skin pigmentation and dullness, making the skin more radiant.

[0125] Preferably, the natural antioxidant is any one of ergothioneine, sage extract, black wolfberry extract, or a mixture thereof.

[0126] Ergothioneine is a natural sulfur-containing amino acid that has a variety of benefits in skin care.

[0127] (1) Antioxidant effect. Ergothioneine is a natural antioxidant that can remove free radicals, reduce the damage caused by free radicals to the skin, and prevent and delay skin aging caused by oxidation.

[0128] (2) Sun protection effect. Ergothioneine can inhibit the activity of tyrosinase, help filter ultraviolet rays, reduce skin oxidative stress, protect the skin from ultraviolet damage, prevent excessive melanin production, whiten the skin, reduce spots, and brighten the skin tone.

[0129] (3) Moisturizing effect. Ergothioneine has a moisturizing effect, which can prevent skin dryness and keep the skin hydrated.

[0130] (4) Ergothioneine also has the effects of controlling oil secretion, clearing acne, removing dead skin, and reducing inflammation.

[0131] Sage extract has a variety of benefits in skin care.

[0132] (1) Antioxidant effect. Sage extract is rich in powerful antioxidants such as polyphenol compounds. These ingredients have the ability to scavenge free radicals and can significantly reduce oxidative stress damage to the skin. Therefore, it can effectively slow down the aging process, prevent the formation of wrinkles and fine lines, and make the skin glow with youthful radiance.

[0133] (2) Anti-inflammatory effect. Sage extract also contains a series of ingredients with anti-inflammatory properties, such as basilone, which is very beneficial for relieving skin inflammation and redness. Especially for sensitive skin and skin prone to acne, its anti-inflammatory and calming effect will bring significant improvement.

[0134] (3) Regulating effect. Sage extract also has an oil-control effect and can regulate sebum secretion, which is especially important for oily skin and acne-prone skin. By reducing excess oil, it keeps the skin refreshed, reduces the formation of acne, and makes the skin healthier;

[0135] Black wolfberry extract has multiple benefits in skin care.

[0136] (1) Antioxidant effect. Black wolfberry extract is rich in anthocyanins and has a strong antioxidant effect. It can delay aging, enhance vascular elasticity, and inhibit allergies and inflammation.

[0137] (2) Immune effect. Black wolfberry extract is also rich in wolfberry polysaccharides, which are water-soluble polysaccharides that can enhance nonspecific immune function, improve disease resistance, and inhibit tumor growth and cell mutation. Black wolfberry extract also has anti-radiation and body protection effects.

[0138] Preferably, the natural preservative is any one of peppermint extract, xanthan gum, and bay leaf extract, or a mixture thereof.

[0139] Among them, peppermint extract has multiple benefits in skin care.

[0140] (1) Antibacterial effect. Peppermint extract has a certain inhibitory effect on fungi and viruses. It is relatively safe and non-comedogenic. It generally has no effect on pregnant women and can be used with confidence.

[0141] (2) Cooling effect. Peppermint extract is rich in menthol, menthol acid, menthol and other ingredients, which have calming and cooling effects and can soothe the skin. In the summer, under direct sunlight, the skin is easily irritated and damaged, and redness, swelling and itching may occur. Peppermint extract can help cool down the skin, reduce swelling, and restore it, reduce the inflammatory response of the skin after sun exposure, and soothe the skin's discomfort.

[0142] (3) Oil control. Peppermint extract can also control oil. In summer, the skin is prone to oiliness. An appropriate amount of peppermint extract can absorb excess oil secretion and achieve an oil control effect.

[0143] Xanthan gum, also known as xanthan gum, is a kind of microbial extracellular polysaccharide with a wide range of functions produced by fermentation of Xanthomonas campestris with carbohydrates as the main raw materials. It has unique rheological properties, good water solubility, stability to heat and acid and alkali, good compatibility with various salts, and has multiple functions in skin care.

[0144] (1) Moisturizing effect. Xanthan gum has strong water absorption and forms a colloid similar to collagen after contact with water, which plays a moisturizing role and produces anti-aging effects. It can form a protective film on the skin surface to prevent water loss, keep the skin moisturized, reduce dryness, and make the skin smooth and delicate.

[0145] (2) Whitening effect: Xanthan gum can inhibit the activity of tyrosinase, help lighten spots, and make the skin white and shiny.

[0146] (3) Antioxidant effect. Xanthan gum is rich in vitamin E, which can remove free radicals in the skin, has antioxidant effects, inhibits the formation of melanin, and improves problems such as rough and dull skin.

[0147] (4) Repair effect. Xanthan gum can repair the skin barrier, reduce skin irritation, and improve skin itching and redness. Xanthan gum also has the effect of promoting cell growth and wound healing.

[0148] (5) Emulsification. Due to its stable chemical properties, xanthan gum is also often used as a thickener and emulsifier in cosmetics.

[0149] (6) Antiseptic effect. In addition, xanthan gum also has an antiseptic and fresh-keeping effect.

[0150] Bay leaf extract is a common natural plant extract with various benefits in skin care.

[0151] (1) Antibacterial and anti-inflammatory effects. Bay leaf extract is rich in flavonoids, which have very strong antibacterial effects and can effectively kill bacteria and viruses on the skin surface, thereby reducing skin inflammation and infection. Flavonoids also have strong anti-inflammatory effects and can effectively reduce skin inflammation, redness, and swelling caused by excessive rubbing.

[0152] (2) Oil control and astringent effect. The tannic acid in bay leaf extract has a strong astringent effect, which can effectively shrink pores and reduce facial oil secretion, and regulate the water and oil balance of the skin.

[0153] (3) Antioxidant effect. Bay leaf extract also has a good antioxidant effect, which can protect the skin from damage caused by environmental stress such as ultraviolet rays and haze.

[0154] Preferably, the natural emulsifier is any one of apricot gum, tragacanth gum, gum arabic or a mixture thereof.

[0155] Among them, apricot gum is a brown block formed by the gum secreted by the apricot tree. It is a kind of natural gum and has multiple functions in skin care.

[0156] (1) Emulsification. Apricot gum can be used as a stabilizer, thickener and emulsifier, and its emulsification ability and viscosity are both higher than those of gum arabic.

[0157] (2) Moisturizing effect. Moisturizing effect is one of the most important effects of apricot gum. Apricot gum can absorb moisture and form a protective film on the skin surface to lock in moisture and prevent moisture evaporation. It can increase the moisture and elasticity of the skin, reduce dryness and wrinkles, and make the skin smooth and tender.

[0158] (3) Anti-aging effect. Apricot gum is rich in collagen and various amino acids, which can promote skin cell regeneration and collagen synthesis. Collagen is an important substance for maintaining skin elasticity and firmness. It can reduce the formation of fine lines and wrinkles and delay the aging process of the skin.

[0159] (4) Whitening effect. Vitamin C and polyphenol compounds in apricot gum have the effect of inhibiting melanin production and promoting skin whitening. It can reduce dark spots, freckles and pigmentation, making the skin brighter and more even.

[0160] (5) Antibacterial effect. The natural antibacterial ingredients in apricot gum can inhibit the growth of acne bacteria, reduce the occurrence of acne, reduce skin sensitivity and redness, and relieve skin discomfort and allergic reactions.

[0161] (6) Astringent effect. Apricot gum also has an astringent effect, which can shrink pores, reduce oil secretion, and improve oily skin.

[0162] (7) Absorption-promoting effect. In addition to the above effects, apricot gum also has the effect of promoting transdermal absorption, which can promote the absorption of active ingredients.

[0163] (8) Antioxidant effect. Apricot gum contains flavonoids, which have excellent antioxidant effects.

[0164] Tragacanth gum, also known as tragacanth gum, tragacanth gum, and tolagan gum, is obtained by drying and refining the gum that oozes out after the trunk and branches of the leguminous plant tragacanth tree are cut. It is mainly composed of galactoarabinan and acidic polysaccharides containing galacturonic acid groups. It has multiple functions in skin care. It has emulsifying, thickening, suspending, gelling, sticky, film-forming, stabilizing and other effects. It can be used as a blocker for sustained-release preparations to regulate the release of drugs.

[0165] Gum arabic, also known as gum arabic, is derived from the exudate of the trunk of the Acacia tree of the Leguminosae family, so it is also called acacia gum. Its main components are high-molecular polysaccharides and their calcium, magnesium and potassium salts. It has multiple functions in skin care.

[0166] (1) Emulsification. Gum Arabic has good emulsification properties and is particularly suitable for water-in-oil emulsion systems. It is widely used as an emulsifier stabilizer in emulsified flavors.

[0167] (2) Film-forming effect. Gum arabic also has good film-forming properties.

[0168] (3) Cleansing effect. As a colloid, gum arabic has good adhesion and adsorption properties, which can effectively absorb dirt and keratin on the face and clean the pores.

[0169] (4) Moisturizing effect. Gum arabic can also form a protective film that effectively blocks damage to the skin from the external environment, slows down water loss, and keeps the skin hydrated.

[0170] (5) Anti-inflammatory effect. In addition, gum arabic has a calming and soothing effect, which can reduce skin sensitivity and redness and swelling, making the skin healthier.

[0171] Preferably, the preparation method of chitosan in step S3 is:

[0172] S3-1 Microbial fermentation:

[0173] After washing the shrimp by-products such as shrimp heads, shrimp shells and shrimp tails to remove impurities, the shrimp by-products are crushed by a high-pressure homogenizer for 30 minutes to obtain shrimp by-product powder with a particle size of less than 100 μm; the shrimp by-product powder, water, glucose and lactic acid bacteria are mixed in a mass ratio of 1:15:1:1, and fermented at 38-40° C. for 36 h to 40 h; trypsin is added to make its concentration reach 1-2 g / L; alkaline protease is added to make its concentration reach 2-3 g / L; and enzymolysis is carried out at 40-50° C. for 6-10 h.

[0174] S3-2 Crude Purification

[0175] After enzymatic hydrolysis, the precipitate is filtered to obtain the protein and the peptides and amino acids after enzymatic hydrolysis are in the filtered supernatant, thereby removing the protein. The precipitate, water and citric acid are mixed in a mass ratio of 5:20:2, and the temperature is raised to 60-70°C, stirred for 2-4 hours, and the crude chitosan is obtained by filtering. The calcium salts such as calcium carbonate are hydrolyzed by citric acid to remove the calcium salts in the chitosan. The crude chitosan is washed with amyl alcohol to remove the pigment.

[0176] S3-3 deacetylation

[0177] The crude chitosan, water, sodium hydroxide and amyl alcohol are mixed in a mass ratio of 1:20:12:4, and treated at 60-80° C. for 30-35 hours; and deacetylated chitosan precipitate is obtained by filtration.

[0178] S3-4 Refining and Purification

[0179] The deacetylated chitosan precipitation solution is subjected to ultrafiltration and dialysis in an acetic acid aqueous solution with a mass ratio of 3-5%, using an ultrafiltration membrane package with a pore size of 40,000 Daltons, chitosan with a molecular weight less than 40,000 Daltons passes through the membrane package and is separated from chitosan with a molecular weight greater than 40,000 Daltons, and a permeate A is collected, wherein the molecular weight of chitosan in the permeate A is less than 40,000 Daltons; the permeate A is subjected to ultrafiltration and dialysis using an ultrafiltration membrane package with a pore size of 20,000 Daltons, chitosan with a molecular weight less than 20,000 Daltons passes through the membrane package and is separated from chitosan with a molecular weight greater than 20,000 Daltons; and chitosan with a molecular weight of 20,000-40,000 Daltons in a reflux liquid B is collected.

[0180] S3-5 Drying

[0181] The reflux liquid B is dried to obtain chitosan, the molecular weight of the chitosan is 20000-40000 Daltons, the degree of deacetylation is greater than 97%, and the purity is greater than 98%.

[0182] Through the above technical solutions, the present invention produces the following technical effects:

[0183] (1) Improve the utilization rate of shrimp industry by-products;

[0184] (2) Through the form of multi-layer nanocomposite emulsion, the plant essential oil is protected and the volatilization of the plant essential oil is reduced; the release rate of the plant essential oil is controlled to produce a slow-release effect;

[0185] The active ingredients have smaller particle size and are easier to be absorbed by the skin, achieving excellent sun protection and skin care effects.

[0186] (3) By controlling the extraction and purification process of chitosan, the molecular weight of chitosan is controlled, the homogeneity of chitosan is improved, and the antibacterial properties of chitosan are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0187] Figure 1 It is a comparative analysis diagram of the moisturizing effects of the embodiment and the comparative example.

[0188] Figure 2 It is a comparative analysis diagram of the whitening effects of the embodiment and the comparative example.

[0189] Figure 3 It is a comparative analysis diagram of the antioxidant effects of the embodiment and the comparative example.

[0190] Figure 4 It is a comparative analysis diagram of the sunscreen effects of the embodiment and the comparative example.

[0191] Figure 5 It is a comparative analysis diagram of the waterproof effect of the embodiment and the comparative example. DETAILED DESCRIPTION

[0192] Therefore, the technical solution of the present application produces beneficial effects and has significant progress.

[0193] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific research process of the present invention is firstly described, and then the process verification and analysis are carried out through specific embodiments and comparative examples.

[0194] Specific research process

[0195] 1. Deacetylation study; test method:

[0196] The crude chitosan, water, sodium hydroxide and amyl alcohol were mixed in a mass ratio of 1:20:12:0, 1:20:12:2, 1:20:12:4 and 1:20:12:8, respectively, and treated at 70°C for 32 hours; the deacetylated chitosan precipitate was obtained by filtration. The deacetylation degree and molecular weight of the prepared chitosan were determined.

[0197] Determination method of chitosan deacetylation degree: Determined by double jump potentiometric titration. Accurately weigh 0.3g of chitosan sample dried to constant weight in a conical flask, add 30mL 0.1mol / L HCl standard solution, stir to completely dissolve the chitosan, and measure the initial pH value. Titrate with 0.1mol / L NaOH standard solution, measure the pH value after adding different volumes of NaOH standard solution, measure three times in parallel, and take the average value of the results. Plot the pH value of the solution against the volume of the NaOH standard solution used for titration to obtain the acid-base titration curve. The deacetylation degree calculation formula is as follows:

[0198] Deacetylation degree = (V NaOH1 -V NaOH2 )×C NaOH ×10 -3 ×16 / m / 0.094

[0199] Where:

[0200] V Na0H1 —The volume of NaOH solution that produces the first sudden jump in pH value (mL);

[0201] V NaOH2 —The volume of NaOH solution that produces the second sudden jump in pH value (mL);

[0202] C NaOH —Concentration of NaOH solution in mol / L;

[0203] m—mass of chitosan g;

[0204] 16—Relative molecular weight of amino group;

[0205] 0.0994—Theoretical amino content.

[0206] Antimicrobial activity assay method:

[0207] 170 μL of LB liquid culture medium with a pH of 5 was added to a 96-well plate, and 20 μL of chitosan oligosaccharide solution was added to make the final concentration of the chitosan oligosaccharide solution 10 g / L, and then 10 μL of 10-fold diluted Escherichia coli suspension (bacterial concentration was 1×108 cfu / mL) was added, and a blank control was set up at the same time. The plate was cultured at 37°C for 2 h, and the colorimetric value at 630 nm was determined. The measurement was repeated three times and the results were averaged.

[0208] Test results and analysis:

[0209] The results of the deacetylation test showed that the deacetylation degree of chitosan was significantly increased after adding amyl alcohol. The deacetylation reaction of chitosan is essentially the hydrolysis of amide. -As a nucleophilic agent, it attacks the acetylamino group in chitosan and hydrolyzes it into amino groups. The deacetylation degree of chitosan obtained by using water as solvent is low. The main reason is that the polarity of water is strong, which makes the nucleophilic agent OH - Solvation, thus greatly reducing the OH - Nucleophilic activity. Pentanol has a weak polarity and can significantly promote the deacetylation reaction.

[0210] The higher the OD630 absorbance, the more vigorous the bacterial growth. The antibacterial activity test results show that when the deacetylation degree of chitosan is higher than 95%, the antibacterial activity increases significantly.

[0211] Table 1 Deacetylation degree experimental results

[0212]

[0213] 2. Study on antibacterial activity of weight average molecular weight

[0214] Test method:

[0215] The deacetylated chitosan precipitate was dissolved in an acetic acid aqueous solution with a mass fraction of 5%, and ultrafiltration was performed using an ultrafiltration membrane package with a pore size of 40,000 Daltons. Chitosan with a molecular weight less than 40,000 Daltons passed through the membrane package and was separated from chitosan with a molecular weight greater than 40,000 Daltons. The reflux liquid was collected as test sample 1, and the permeate A was collected. The permeate A was treated by ultrafiltration and dialysis using an ultrafiltration membrane package with a pore size of 20,000 Daltons. Chitosan with a molecular weight less than 20,000 Daltons passed through the membrane package and was separated from chitosan with a molecular weight greater than 20,000 Daltons; the reflux liquid B was collected as test sample 2, and the permeate was collected as test sample 3. The sample average molecular weight was determined by laser scattering, and the antibacterial activity determination method was the same as that of the "deacetylation study".

[0216] Test results:

[0217] The higher the OD630 absorbance, the more vigorous the bacterial growth and the worse the antibacterial activity of chitosan. The antibacterial test results show that the antibacterial activity of chitosan is weak when the molecular weight is too high or too low, and the antibacterial activity is strongest when the molecular weight is about 30,000.

[0218] Table 2 Antibacterial activity test results

[0219] Test No. Molecular weight (Dalton) Antibacterial activity (OD630 absorbance) Test 1 Sample 66500 0.13 Test 2 Sample 32500 0.01 Test 3 Sample 10500 0.22

[0220] When the molecular weight of chitosan is small, such as monomers, pentamers, and heptamers, the polymer chain is too short and the local charge density is low, which is not conducive to the interaction between the polymer and the negative sites on the cell membrane surface, resulting in very low antibacterial activity.

[0221] When the molecular weight of chitosan is too large, the molecular conformation of chitosan changes from a simple random curl to a compact, almost spherical structure. Since most of the active groups of chitosan are confined to the interior of the spherical molecular structure and are spatially inaccessible, the electrostatic interaction between chitosan and the bacterial cell surface is weakened, resulting in high molecular weight chitosan also showing low antibacterial activity.

[0222] Based on the above research, we conducted process verification of 3 embodiments according to the research results, and conducted comparative studies with the control examples.

[0223] Embodiment 1:

[0224] A method for preparing a chitosan sunscreen skin care composition comprises the following steps:

[0225] After washing the shrimp by-products such as shrimp heads, shrimp shells and shrimp tails to remove impurities, the shrimp by-products were crushed by a high-pressure homogenizer for 30 minutes to obtain shrimp by-product powder with a particle size of less than 100 μm; the shrimp by-product powder, water, glucose and lactic acid bacteria were mixed in a mass ratio of 1:15:1:1, and fermented at 38°C for 36 hours; trypsin was added to make its concentration reach 1 g / L; alkaline protease was added to make its concentration reach 2 g / L; and enzymatic hydrolysis was carried out at 40°C for 6 hours.

[0226] After enzymatic hydrolysis, the precipitate is filtered to obtain the protein and the peptides and amino acids after enzymatic hydrolysis are in the filtered supernatant, thereby removing the protein. The precipitate, water and citric acid are mixed in a mass ratio of 5:20:2, and the temperature is raised to 60°C, stirred for 2 hours, and filtered to obtain the crude chitosan. The calcium salts such as calcium carbonate are hydrolyzed by citric acid to remove the calcium salts in the chitosan. The crude chitosan is washed with amyl alcohol to remove the pigment.

[0227] The crude chitosan, water, sodium hydroxide and amyl alcohol were mixed in a mass ratio of 1:20:12:4 and treated at 60° C. for 30 h; and the deacetylated chitosan precipitate was obtained by filtration.

[0228] The deacetylated chitosan precipitate is dissolved in an acetic acid aqueous solution with a mass fraction of 3%, and ultrafiltration and dialysis are performed using an ultrafiltration membrane package with a pore size of 40,000 Daltons. Chitosan with a molecular weight less than 40,000 Daltons passes through the membrane package and is separated from chitosan with a molecular weight greater than 40,000 Daltons. The permeate A is collected, and the molecular weight of chitosan in the permeate A is less than 40,000 Daltons; the permeate A is treated by ultrafiltration and dialysis using an ultrafiltration membrane package with a pore size of 20,000 Daltons, and chitosan with a molecular weight less than 20,000 Daltons passes through the membrane package and is separated from chitosan with a molecular weight greater than 20,000 Daltons; and the reflux liquid B is collected. The reflux liquid B is dried to obtain chitosan.

[0229] Accurately weigh 5 g of collagen and disperse it in 95 g of 1.5% acetic acid solution. After stirring at room temperature until completely dissolved, continue stirring for 10 minutes to evenly disperse the collagen in the acetic acid solution to obtain a 5% collagen solution.

[0230] Accurately measure the prepared 5% mass fraction collagen solution and carrot seed essential oil with sunscreen effect and add them into a beaker in a volume ratio of 10:1, and disperse them at a speed of 12000r / min for 4 minutes using a high-speed disperser. Take the upper white emulsion and wash it with deionized water until it is neutral to obtain a collagen / carrot seed essential oil emulsion.

[0231] Accurately weigh 10 g of chitosan and disperse it in 90 g of 3% acetic acid solution. After stirring at room temperature until completely dissolved, continue stirring for 11 minutes to evenly disperse the chitosan in the acetic acid solution to obtain a chitosan solution with a mass fraction of 10%.

[0232] Accurately measure the prepared collagen / carrot seed essential oil emulsion and 10% chitosan solution by volume ratio of 5:5, add them into a beaker and stir evenly, then use a high-speed disperser to disperse at a speed of 15000r / min for 3 minutes, take the upper white emulsion and wash it with deionized water until it is neutral to obtain a chitosan / collagen / carrot seed essential oil multilayer nanocomposite emulsion.

[0233] Accurately weigh 2 g of camellia oil, 1 g of wood wax oil, 1 g of sesame oil, 2 g of avocado oil, 2 g of rice bran wax, and 3 g of sunflower seed wax, add them into a beaker, heat in a 75°C water bath and stir evenly until completely melted to obtain solution C.

[0234] Accurately weigh 3 g of glyceryl glucoside and 3 g of urea, add them to 20 g of deionized water, and stir them evenly at room temperature until they are completely dissolved; then add 2 g of green tea extract, 2 g of olive leaf extract, 1 g of ergothioneine, 3 g of black wolfberry extract, and 5 g of peppermint extract, and stir them evenly at room temperature until they are completely dissolved to obtain solution D;

[0235] Accurately weigh 1g of apricot gum and 1g of gum arabic, add them to 20g of deionized water, and stir them evenly at room temperature until they are completely dissolved; then add 20g of chitosan / collagen / carrot seed essential oil multilayer nanocomposite emulsion, solution C, solution D, and 8g of the remaining water, and stir them evenly at room temperature until they are completely emulsified, so as to obtain a sunscreen skin care product with uniform texture, delicate application, smooth skin feel, refreshing and non-greasy, excellent sunscreen effect and waterproof properties.

[0236] Embodiment 2:

[0237] A method for preparing a chitosan sunscreen skin care composition comprises the following steps:

[0238] After washing the shrimp by-products such as shrimp heads, shrimp shells and shrimp tails to remove impurities, the shrimp by-products are crushed by a high-pressure homogenizer for 30 minutes to obtain shrimp by-product powder with a particle size of less than 100 μm; the shrimp by-product powder, water, glucose and lactic acid bacteria are mixed in a mass ratio of 1:15:1:1, and fermented at 40°C for 40 hours; trypsin is added to make its concentration reach 2 g / L; alkaline protease is added to make its concentration reach 3 g / L; and enzymolysis is carried out at 50°C for 10 hours.

[0239] After enzymatic hydrolysis, the precipitate is filtered to obtain the protein and the peptides and amino acids after enzymatic hydrolysis are in the filtered supernatant, thereby removing the protein. The precipitate, water and citric acid are mixed in a mass ratio of 5:20:2, and the temperature is raised to 70°C, stirred for 4 hours, and filtered to obtain the crude chitosan. The calcium salts such as calcium carbonate are hydrolyzed by citric acid to remove the calcium salts in the chitosan. The crude chitosan is washed with amyl alcohol to remove the pigment.

[0240] The crude chitosan, water, sodium hydroxide and amyl alcohol were mixed in a mass ratio of 1:20:12:4 and treated at 80°C for 35h; the deacetylated chitosan precipitate was obtained by filtration.

[0241] The deacetylated chitosan precipitate is dissolved in an acetic acid aqueous solution with a mass fraction of 5%, and ultrafiltration and dialysis are performed using an ultrafiltration membrane package with a pore size of 40,000 Daltons. Chitosan with a molecular weight less than 40,000 Daltons passes through the membrane package and is separated from chitosan with a molecular weight greater than 40,000 Daltons. The permeate A is collected, and the molecular weight of chitosan in the permeate A is less than 40,000 Daltons; the permeate A is treated by ultrafiltration and dialysis using an ultrafiltration membrane package with a pore size of 20,000 Daltons, and chitosan with a molecular weight less than 20,000 Daltons passes through the membrane package and is separated from chitosan with a molecular weight greater than 20,000 Daltons; and the reflux liquid B is collected. The reflux liquid B is dried to obtain chitosan.

[0242] Accurately weigh 10 g of collagen and disperse it in 90 g of 2% acetic acid solution. After stirring at room temperature until completely dissolved, continue stirring for 12 minutes to evenly disperse the collagen in the acetic acid solution to obtain a 10% collagen solution.

[0243] Accurately measure the prepared collagen solution with a mass fraction of 10% and lavender essential oil with sunscreen effect and add them into a beaker in a volume ratio of 9:1. Use a high-speed disperser to disperse them at a speed of 15000r / min for 3 minutes. Take the upper white emulsion and wash it with deionized water until it is neutral to obtain a collagen / lavender essential oil emulsion.

[0244] 15 g of chitosan was accurately weighed and dispersed in 85 g of 1% acetic acid solution. After being completely dissolved by stirring at room temperature, stirring was continued for 13 min to uniformly disperse the chitosan in the acetic acid solution to obtain a chitosan solution with a mass fraction of 15%.

[0245] Accurately measure the prepared collagen / lavender essential oil emulsion and 15% chitosan solution by volume ratio of 3:5, add them into a beaker and stir evenly, then use a high-speed disperser to disperse at a speed of 12000r / min for 4 minutes, take the upper white emulsion and wash it with deionized water until it is neutral to obtain a chitosan / collagen / lavender essential oil multilayer nanocomposite emulsion.

[0246] Accurately weigh 2 g of camellia oil, 2 g of avocado oil, 3 g of sugarcane wax, and 3 g of laurel wax into a beaker, heat in an 80°C water bath and stir evenly until completely melted to obtain solution C.

[0247] Accurately weigh 4 g of glyceryl glucoside, 2 g of hydrolyzed collagen, and 1 g of urea, add them to 20 g of deionized water, and stir them evenly at room temperature until they are completely dissolved; then add 2 g of green tea extract, 1 g of licorice extract, 2 g of ergothioneine, 2 g of sage extract, and 5 g of laurel leaf extract, and stir them evenly at room temperature until they are completely dissolved to obtain solution D;

[0248] Accurately weigh 1g of tragacanth gum and 1g of gum arabic, add them to 20g of deionized water, and stir them evenly at room temperature until they are completely dissolved; then add 10g of chitosan / collagen / lavender essential oil multilayer nanocomposite emulsion, solution C, solution D, and 19g of the remaining water, and stir them evenly at room temperature until they are completely emulsified, so as to obtain a sunscreen skin care product with uniform texture, delicate application, smooth skin feel, refreshing and non-greasy, excellent sunscreen effect and waterproof properties.

[0249] Embodiment 3:

[0250] A method for preparing a chitosan sunscreen skin care composition comprises the following steps:

[0251] After washing the shrimp by-products such as shrimp heads, shrimp shells and shrimp tails to remove impurities, the shrimp by-products were crushed by a high-pressure homogenizer for 30 minutes to obtain shrimp by-product powder with a particle size of less than 100 μm; the shrimp by-product powder, water, glucose and lactic acid bacteria were mixed in a mass ratio of 1:15:1:1, and fermented at 39°C for 38 hours; trypsin was added to make its concentration reach 1.5 g / L; alkaline protease was added to make its concentration reach 2.5 g / L; and enzymatic hydrolysis was carried out at 45°C for 8 hours.

[0252] After enzymatic hydrolysis, the precipitate is filtered to obtain the protein and the peptides and amino acids after enzymatic hydrolysis are in the filtered supernatant, thereby removing the protein. The precipitate, water and citric acid are mixed in a mass ratio of 5:20:2, and the temperature is raised to 65°C, stirred for 3 hours, and filtered to obtain the crude chitosan. The calcium salts such as calcium carbonate are hydrolyzed by citric acid to remove the calcium salts in the chitosan. The crude chitosan is washed with amyl alcohol to remove the pigment.

[0253] The crude chitosan, water, sodium hydroxide and amyl alcohol were mixed in a mass ratio of 1:20:12:4 and treated at 70°C for 32 hours; the deacetylated chitosan precipitate was obtained by filtration.

[0254] The deacetylated chitosan precipitate is dissolved in an acetic acid aqueous solution with a mass fraction of 4%, and an ultrafiltration membrane package with a pore size of 40,000 Daltons is used for ultrafiltration and dialysis, and chitosan with a molecular weight less than 40,000 Daltons passes through the membrane package and is separated from chitosan with a molecular weight greater than 40,000 Daltons, and a permeate A is collected, and the molecular weight of chitosan in the permeate A is less than 40,000 Daltons; an ultrafiltration membrane package with a pore size of 20,000 Daltons is used for ultrafiltration and dialysis treatment of the permeate A, and chitosan with a molecular weight less than 20,000 Daltons passes through the membrane package and is separated from chitosan with a molecular weight greater than 20,000 Daltons; a reflux liquid B is collected, and the reflux liquid B is dried to obtain chitosan.

[0255] Accurately weigh 15 g of collagen and disperse it in 85 g of 3% acetic acid solution. After stirring at room temperature until completely dissolved, continue stirring for 14 minutes to evenly disperse the collagen in the acetic acid solution to obtain a collagen solution with a mass fraction of 15%.

[0256] Accurately measure the prepared collagen solution with a mass fraction of 15% and myrrh essential oil with sunscreen effect and add them into a beaker in a volume ratio of 8:1, and disperse them at a speed of 10000r / min for 5 minutes using a high-speed disperser. Take the upper white emulsion and wash it with deionized water until it is neutral to obtain a collagen / myrrh essential oil emulsion.

[0257] Accurately weigh 20 g of chitosan and disperse it in 80 g of 1.5% acetic acid solution. After stirring at room temperature until completely dissolved, continue stirring for 15 minutes to evenly disperse the chitosan in the acetic acid solution to obtain a chitosan solution with a mass fraction of 20%.

[0258] Accurately measure the prepared collagen / myrrh essential oil emulsion and 20% chitosan solution by volume ratio of 1:5, add them into a beaker and stir evenly, then use a high-speed disperser to disperse at a speed of 10000r / min for 5 minutes, take the upper white emulsion and wash it with deionized water until it is neutral to obtain a chitosan / collagen / myrrh essential oil multilayer nanocomposite emulsion.

[0259] Accurately weigh 2 g of wood wax oil, 3 g of sesame oil, 4 g of sunflower seed wax, and 2 g of laurel wax into a beaker, heat in an 85°C water bath and stir evenly until completely melted to obtain solution C.

[0260] Accurately weigh 4 g of hydrolyzed collagen and 2 g of urea, add them to 20 g of deionized water, and stir them evenly at room temperature until they are completely dissolved; then add 3 g of safflower extract, 2 g of lavender extract, 4 g of sage extract, 1 g of xanthan gum, and 2 g of laurel leaf extract, and stir them evenly at room temperature until they are completely dissolved to obtain solution D;

[0261] Accurately weigh 1.5 g of tragacanth gum and add it to 20 g of deionized water, and stir it evenly at room temperature until it is completely dissolved; then add 15 g of chitosan / collagen / myrrh essential oil multilayer nanocomposite emulsion, solution C, solution D, and 14.5 g of the remaining water, and stir it evenly at room temperature until it is completely emulsified, so as to obtain a sunscreen skin care product with uniform texture, delicate application, smooth skin feel, refreshing and non-greasy, excellent sunscreen effect and waterproof properties.

[0262] Embodiment 4:

[0263] A method for preparing a chitosan sunscreen skin care composition comprises the following steps:

[0264] After washing the shrimp by-products such as shrimp heads, shrimp shells and shrimp tails to remove impurities, the shrimp by-products were crushed by a high-pressure homogenizer for 30 minutes to obtain shrimp by-product powder with a particle size of less than 100 μm; the shrimp by-product powder, water, glucose and lactic acid bacteria were mixed in a mass ratio of 1:15:1:1, and fermented at 38°C for 36 hours; trypsin was added to make its concentration reach 1 g / L; alkaline protease was added to make its concentration reach 2 g / L; and enzymatic hydrolysis was carried out at 40°C for 6 hours.

[0265] After enzymatic hydrolysis, the precipitate is filtered to obtain the protein and the peptides and amino acids after enzymatic hydrolysis are in the filtered supernatant, thereby removing the protein. The precipitate, water and citric acid are mixed in a mass ratio of 5:20:2, and the temperature is raised to 60°C, stirred for 2 hours, and filtered to obtain the crude chitosan. The calcium salts such as calcium carbonate are hydrolyzed by citric acid to remove the calcium salts in the chitosan. The crude chitosan is washed with amyl alcohol to remove the pigment.

[0266] The crude chitosan, water, sodium hydroxide and amyl alcohol were mixed in a mass ratio of 1:20:12:4 and treated at 60° C. for 30 h; and the deacetylated chitosan precipitate was obtained by filtration.

[0267] The deacetylated chitosan precipitate is dissolved in an acetic acid aqueous solution with a mass fraction of 3%, and ultrafiltration and dialysis are performed using an ultrafiltration membrane package with a pore size of 40,000 Daltons. Chitosan with a molecular weight less than 40,000 Daltons passes through the membrane package and is separated from chitosan with a molecular weight greater than 40,000 Daltons. The permeate A is collected, and the molecular weight of chitosan in the permeate A is less than 40,000 Daltons; the permeate A is treated by ultrafiltration and dialysis using an ultrafiltration membrane package with a pore size of 20,000 Daltons, and chitosan with a molecular weight less than 20,000 Daltons passes through the membrane package and is separated from chitosan with a molecular weight greater than 20,000 Daltons; and the reflux liquid B is collected. The reflux liquid B is dried to obtain chitosan.

[0268] Accurately weigh 20 g of collagen and disperse it in 80 g of 1% acetic acid solution. After stirring at room temperature until completely dissolved, continue stirring for 15 minutes to evenly disperse the collagen in the acetic acid solution to obtain a 20% collagen solution.

[0269] Accurately measure the prepared collagen solution with a mass fraction of 20% and chamomile essential oil with sunscreen effect and add them into a beaker in a volume ratio of 5:1. Use a high-speed disperser to disperse them at a speed of 13000r / min for 4 minutes. Take the upper white emulsion and wash it with deionized water until it is neutral to obtain a collagen / chamomile essential oil emulsion.

[0270] Accurately weigh 25 g of chitosan and disperse it in 75 g of 2.5% acetic acid solution. After stirring at room temperature until completely dissolved, continue stirring for 10 minutes to evenly disperse the chitosan in the acetic acid solution to obtain a chitosan solution with a mass fraction of 25%.

[0271] Accurately measure the prepared collagen / chamomile essential oil emulsion and 25% chitosan solution by volume ratio of 4:5, add them into a beaker and stir evenly, then use a high-speed disperser to disperse at a speed of 13000r / min for 4 minutes, take the upper white emulsion and wash it with deionized water until it is neutral to obtain chitosan / collagen / chamomile essential oil multilayer nanocomposite emulsion.

[0272] Accurately weigh 3 g of camellia oil, 3 g of sesame oil, 2 g of rice bran wax, and 3 g of sugarcane wax, add them into a beaker, heat in a 78°C water bath and stir evenly until they are completely melted to obtain solution C.

[0273] Accurately weigh 5 g of glyceryl glucoside and add it to 20 g of deionized water, and stir it evenly at room temperature until it is completely dissolved; then add 2 g of olive leaf extract, 2 g of safflower extract, 5 g of black wolfberry extract, 3 g of peppermint extract, and 2 g of laurel leaf extract, and stir it evenly at room temperature until it is completely dissolved to obtain solution D;

[0274] Accurately weigh 0.8 g of apricot gum and 0.8 g of tragacanth gum, add them to 20 g of deionized water, and stir them evenly at room temperature until they are completely dissolved; then add 25 g of chitosan / collagen / chamomile essential oil multilayer nanocomposite emulsion, solution C, solution D, and 3.4 g of the remaining water, and stir them evenly at room temperature until they are completely emulsified, so as to obtain a sunscreen skin care product with uniform texture, delicate application, smooth skin feel, refreshing and non-greasy, excellent sunscreen effect and waterproof properties.

[0275] Embodiment 5:

[0276] A method for preparing a chitosan sunscreen skin care composition comprises the following steps:

[0277] After washing the shrimp by-products such as shrimp heads, shrimp shells and shrimp tails to remove impurities, the shrimp by-products are crushed by a high-pressure homogenizer for 30 minutes to obtain shrimp by-product powder with a particle size of less than 100 μm; the shrimp by-product powder, water, glucose and lactic acid bacteria are mixed in a mass ratio of 1:15:1:1, and fermented at 40°C for 40 hours; trypsin is added to make its concentration reach 2 g / L; alkaline protease is added to make its concentration reach 3 g / L; and enzymolysis is carried out at 50°C for 10 hours.

[0278] After enzymatic hydrolysis, the precipitate is filtered to obtain the protein and the peptides and amino acids after enzymatic hydrolysis are in the filtered supernatant, thereby removing the protein. The precipitate, water and citric acid are mixed in a mass ratio of 5:20:2, and the temperature is raised to 70°C, stirred for 4 hours, and filtered to obtain the crude chitosan. The calcium salts such as calcium carbonate are hydrolyzed by citric acid to remove the calcium salts in the chitosan. The crude chitosan is washed with amyl alcohol to remove the pigment.

[0279] The crude chitosan, water, sodium hydroxide and amyl alcohol were mixed in a mass ratio of 1:20:12:4 and treated at 80°C for 35h; the deacetylated chitosan precipitate was obtained by filtration.

[0280] The deacetylated chitosan precipitate is dissolved in an acetic acid aqueous solution with a mass fraction of 5%, and ultrafiltration and dialysis are performed using an ultrafiltration membrane package with a pore size of 40,000 Daltons. Chitosan with a molecular weight less than 40,000 Daltons passes through the membrane package and is separated from chitosan with a molecular weight greater than 40,000 Daltons. The permeate A is collected, and the molecular weight of chitosan in the permeate A is less than 40,000 Daltons; the permeate A is treated by ultrafiltration and dialysis using an ultrafiltration membrane package with a pore size of 20,000 Daltons, and chitosan with a molecular weight less than 20,000 Daltons passes through the membrane package and is separated from chitosan with a molecular weight greater than 20,000 Daltons; and the reflux liquid B is collected. The reflux liquid B is dried to obtain chitosan.

[0281] Accurately weigh 8 g of collagen and disperse it in 92 g of 2.5% acetic acid solution. After stirring at room temperature until completely dissolved, continue stirring for 11 minutes to evenly disperse the collagen in the acetic acid solution to obtain a collagen solution with a mass fraction of 8%.

[0282] Accurately measure the prepared 8% mass fraction collagen solution and lavender essential oil with sunscreen effect and add them into a beaker in a volume ratio of 7:1, and disperse them at a speed of 14000r / min for 3 minutes using a high-speed disperser. Take the upper white emulsion and wash it with deionized water until it is neutral to obtain a collagen / lavender essential oil emulsion.

[0283] Accurately weigh 30 g of chitosan and disperse it in 70 g of 1.2% acetic acid solution. After stirring at room temperature until completely dissolved, continue stirring for 14 minutes to evenly disperse the chitosan in the acetic acid solution to obtain a chitosan solution with a mass fraction of 30%.

[0284] Accurately measure the prepared collagen / lavender essential oil emulsion and 30% chitosan solution by volume ratio of 2:5, add them into a beaker and stir evenly, then use a high-speed disperser to disperse at a speed of 11000r / min for 5 minutes, take the upper white emulsion and wash it with deionized water until it is neutral to obtain chitosan / collagen / lavender essential oil multilayer nanocomposite emulsion.

[0285] Accurately weigh 2 g of wood wax oil, 2 g of avocado oil, 1 g of rice bran wax, 1 g of sugarcane wax, 2 g of sunflower seed wax, and 2 g of laurel wax into a beaker, heat in a water bath at 82° C. and stir evenly until completely melted to obtain solution C.

[0286] Accurately weigh 5 g of hydrolyzed collagen and add it to 20 g of deionized water, stirring evenly at room temperature until it is completely dissolved; then add 3 g of licorice extract, 2 g of lavender extract, 3 g of sage extract, 3 g of black wolfberry extract, and 3 g of xanthan gum, stirring evenly at room temperature until it is completely dissolved, to obtain solution D;

[0287] Accurately weigh 2 g of gum arabic and add it to 20 g of deionized water, and stir it evenly at room temperature until it is completely dissolved; then add 22 g of chitosan / collagen / lavender essential oil multilayer nanocomposite emulsion, solution C, solution D, and 7 g of remaining water, and stir it evenly at room temperature until it is completely emulsified, so as to obtain a sunscreen skin care product with uniform texture, delicate application, smooth skin feel, refreshing and non-greasy, excellent sunscreen effect and waterproof properties.

[0288] Embodiment 6:

[0289] A method for preparing a chitosan sunscreen skin care composition comprises the following steps:

[0290] After washing the shrimp by-products such as shrimp heads, shrimp shells and shrimp tails to remove impurities, the shrimp by-products were crushed by a high-pressure homogenizer for 30 minutes to obtain shrimp by-product powder with a particle size of less than 100 μm; the shrimp by-product powder, water, glucose and lactic acid bacteria were mixed in a mass ratio of 1:15:1:1, and fermented at 39°C for 38 hours; trypsin was added to make its concentration reach 1.5 g / L; alkaline protease was added to make its concentration reach 2.5 g / L; and enzymatic hydrolysis was carried out at 45°C for 8 hours.

[0291] After enzymatic hydrolysis, the precipitate is filtered to obtain the protein and the peptides and amino acids after enzymatic hydrolysis are in the filtered supernatant, thereby removing the protein. The precipitate, water and citric acid are mixed in a mass ratio of 5:20:2, and the temperature is raised to 65°C, stirred for 3 hours, and filtered to obtain the crude chitosan. The calcium salts such as calcium carbonate are hydrolyzed by citric acid to remove the calcium salts in the chitosan. The crude chitosan is washed with amyl alcohol to remove the pigment.

[0292] The crude chitosan, water, sodium hydroxide and amyl alcohol were mixed in a mass ratio of 1:20:12:4 and treated at 70°C for 32 hours; the deacetylated chitosan precipitate was obtained by filtration.

[0293] The deacetylated chitosan precipitate is dissolved in an acetic acid aqueous solution with a mass fraction of 4%, and an ultrafiltration membrane package with a pore size of 40,000 Daltons is used for ultrafiltration and dialysis, and chitosan with a molecular weight less than 40,000 Daltons passes through the membrane package and is separated from chitosan with a molecular weight greater than 40,000 Daltons, and a permeate A is collected, and the molecular weight of chitosan in the permeate A is less than 40,000 Daltons; an ultrafiltration membrane package with a pore size of 20,000 Daltons is used for ultrafiltration and dialysis treatment of the permeate A, and chitosan with a molecular weight less than 20,000 Daltons passes through the membrane package and is separated from chitosan with a molecular weight greater than 20,000 Daltons; a reflux liquid B is collected, and the reflux liquid B is dried to obtain chitosan.

[0294] 18 g of collagen was accurately weighed and dispersed in 82 g of 2.8% acetic acid solution. After being completely dissolved by stirring at room temperature, stirring was continued for 13 min to evenly disperse the collagen in the acetic acid solution to obtain a collagen solution with a mass fraction of 18%.

[0295] Accurately measure the prepared collagen solution with a mass fraction of 18% and myrrh essential oil with sunscreen effect in a volume ratio of 6:1 and add them to a beaker. Use a high-speed disperser to disperse them at a speed of 11000r / min for 5 minutes. Take the upper white emulsion and wash it with deionized water until it is neutral to obtain a collagen / myrrh essential oil emulsion.

[0296] Accurately weigh 5 g of chitosan and disperse it in 95 g of 2% acetic acid solution. After stirring at room temperature until completely dissolved, continue stirring for 12 minutes to evenly disperse the chitosan in the acetic acid solution to obtain a 5% chitosan solution.

[0297] Accurately measure the prepared collagen / myrrh essential oil emulsion and 5% chitosan solution by volume ratio of 5:5, add them into a beaker and stir evenly, then use a high-speed disperser to disperse at a speed of 14000r / min for 3 minutes, take the upper white emulsion and wash it with deionized water until it is neutral to obtain a chitosan / collagen / myrrh essential oil multilayer nanocomposite emulsion.

[0298] Accurately weigh 2 g of camellia oil, 2 g of sesame oil, 2 g of avocado oil, 3 g of rice bran wax, and 3 g of laurel wax into a beaker, heat in a 76°C water bath and stir evenly until completely melted to obtain solution C.

[0299] Accurately weigh 2 g of glyceryl glucoside, 2 g of hydrolyzed collagen, and 3 g of urea, add them to 20 g of deionized water, and stir them evenly at room temperature until they are completely dissolved; then add 2 g of safflower extract, 3 g of licorice extract, 3 g of ergothioneine, 2 g of peppermint extract, and 2 g of xanthan gum, and stir them evenly at room temperature until they are completely dissolved to obtain solution D;

[0300] Accurately weigh 1.5 g of apricot gum and add it to 20 g of deionized water, and stir it evenly at room temperature until it is completely dissolved; then add 18 g of chitosan / collagen / myrrh essential oil multilayer nanocomposite emulsion, solution C, solution D, and 9.5 g of the remaining water, and stir it evenly at room temperature until it is completely emulsified, so as to obtain a sunscreen skin care product with uniform texture, delicate application, smooth skin feel, refreshing and non-greasy, excellent sunscreen effect and waterproof properties.

[0301] Comparative Examples 1-6 are the control groups of Examples 1-6, except that the chitosan / collagen / plant essential oil multilayer nanocomposite emulsion is not added, and the other ingredients are the same as those of Examples 1-6, wherein the proportion of the chitosan / collagen / plant essential oil multilayer nanocomposite emulsion is supplemented with the balance water.

[0302] Comparative Example 1:

[0303] The preparation method comprises the following steps:

[0304] Accurately weigh 2 g of camellia oil, 1 g of wood wax oil, 1 g of sesame oil, 2 g of avocado oil, 2 g of rice bran wax, and 3 g of sunflower seed wax, add them into a beaker, heat in an 85°C water bath and stir evenly until they are completely melted to obtain solution C.

[0305] Accurately weigh 3 g of glyceryl glucoside and 3 g of urea, add them to 20 g of deionized water, and stir them evenly at room temperature until they are completely dissolved; then add 2 g of green tea extract, 2 g of olive leaf extract, 1 g of ergothioneine, 3 g of black wolfberry extract, and 5 g of peppermint extract, and stir them evenly at room temperature until they are completely dissolved to obtain solution D;

[0306] Accurately weigh 1g of apricot gum and 1g of gum arabic, add them to 20g of deionized water, and stir evenly at room temperature until completely dissolved; then add solution C, solution D, and 28g of the remaining water, and stir evenly at room temperature until completely emulsified, to obtain the skin care product of Comparative Example 1.

[0307] Comparative Example 2:

[0308] The preparation method comprises the following steps:

[0309] Accurately weigh 2 g of camellia oil, 2 g of avocado oil, 3 g of sugarcane wax, and 3 g of laurel wax into a beaker, heat in an 85°C water bath and stir evenly until completely melted to obtain solution C.

[0310] Accurately weigh 4 g of glyceryl glucoside, 2 g of hydrolyzed collagen, and 1 g of urea, add them to 20 g of deionized water, and stir them evenly at room temperature until they are completely dissolved; then add 2 g of green tea extract, 1 g of licorice extract, 2 g of ergothioneine, 2 g of sage extract, and 5 g of laurel leaf extract, and stir them evenly at room temperature until they are completely dissolved to obtain solution D;

[0311] Accurately weigh 1g of tragacanth gum and 1g of gum arabic, add them to 20g of deionized water, stir them evenly at room temperature until they are completely dissolved; then add solution C, solution D, and 29g of the remaining water, stir them evenly at room temperature until they are completely emulsified, and the skin care product of comparative example 2 is obtained.

[0312] Comparative Example 3:

[0313] The preparation method comprises the following steps:

[0314] Accurately weigh 2 g of wood wax oil, 3 g of sesame oil, 4 g of sunflower seed wax, and 2 g of laurel wax into a beaker, heat in an 85°C water bath and stir evenly until completely melted to obtain solution C.

[0315] Accurately weigh 4 g of hydrolyzed collagen and 2 g of urea, add them to 20 g of deionized water, and stir them evenly at room temperature until they are completely dissolved; then add 3 g of safflower extract, 2 g of lavender extract, 4 g of sage extract, 1 g of xanthan gum, and 2 g of laurel leaf extract, and stir them evenly at room temperature until they are completely dissolved to obtain solution D;

[0316] Accurately weigh 1.5 g of tragacanth gum and add it to 20 g of deionized water, and stir evenly at room temperature until it is completely dissolved; then add solution C, solution D, and 29.5 g of the remaining water, and stir evenly at room temperature until it is completely emulsified, to obtain the skin care product of Comparative Example 3.

[0317] Comparative Example 4:

[0318] The preparation method comprises the following steps:

[0319] Accurately weigh 3 g of camellia oil, 3 g of sesame oil, 2 g of rice bran wax, and 3 g of sugarcane wax, add them into a beaker, heat in an 85°C water bath and stir evenly until they are completely melted to obtain solution C.

[0320] Accurately weigh 5 g of glyceryl glucoside and add it to 20 g of deionized water, and stir it evenly at room temperature until it is completely dissolved; then add 2 g of olive leaf extract, 2 g of safflower extract, 5 g of black wolfberry extract, 3 g of peppermint extract, and 2 g of laurel leaf extract, and stir it evenly at room temperature until it is completely dissolved to obtain solution D;

[0321] Accurately weigh 0.8 g of apricot gum and 0.8 g of tragacanth gum, add them to 20 g of deionized water, and stir evenly at room temperature until completely dissolved; then add solution C, solution D, and 28.4 g of the remaining water, and stir evenly at room temperature until completely emulsified, to obtain the skin care product of Comparative Example 4.

[0322] Comparative Example 5:

[0323] The preparation method comprises the following steps:

[0324] Accurately weigh 2 g of wood wax oil, 2 g of avocado oil, 1 g of rice bran wax, 1 g of sugarcane wax, 2 g of sunflower seed wax, and 2 g of laurel wax into a beaker, heat in an 85°C water bath and stir evenly until completely melted to obtain solution C.

[0325] Accurately weigh 5 g of hydrolyzed collagen and add it to 20 g of deionized water, stirring evenly at room temperature until it is completely dissolved; then add 3 g of licorice extract, 2 g of lavender extract, 3 g of sage extract, 3 g of black wolfberry extract, and 3 g of xanthan gum, stirring evenly at room temperature until it is completely dissolved, to obtain solution D;

[0326] Accurately weigh 2 g of gum arabic and add it to 20 g of deionized water, and stir evenly at room temperature until it is completely dissolved; then add solution C, solution D, and 29 g of the remaining water, and stir evenly at room temperature until it is completely emulsified, to obtain the skin care product of comparative example 5.

[0327] Comparative Example 6:

[0328] The preparation method comprises the following steps:

[0329] Accurately weigh 2 g of camellia oil, 2 g of sesame oil, 2 g of avocado oil, 3 g of rice bran wax, and 3 g of laurel wax into a beaker, heat in an 85°C water bath and stir evenly until completely melted to obtain solution C.

[0330] Accurately weigh 2 g of glyceryl glucoside, 2 g of hydrolyzed collagen, and 3 g of urea, add them to 20 g of deionized water, and stir them evenly at room temperature until they are completely dissolved; then add 2 g of safflower extract, 3 g of licorice extract, 3 g of ergothioneine, 2 g of peppermint extract, and 2 g of xanthan gum, and stir them evenly at room temperature until they are completely dissolved to obtain solution D;

[0331] Accurately weigh 1.5 g of apricot gum and add it to 20 g of deionized water, and stir evenly at room temperature until it is completely dissolved; then add Solution C, Solution D, and 27.5 g of the remaining water, and stir evenly at room temperature until it is completely emulsified, to obtain the skin care product of Comparative Example 6.

[0332] The skin care products obtained from the above Examples 1-6 and Comparative Examples 1-6 were evaluated.

[0333] (1) Sensory evaluation

[0334] A total of 120 volunteers were selected, numbered 1-120, all of whom were female, and their facial skin had the following conditions to varying degrees: skin redness, pain, itching, dryness, tightness, peeling, blackening, dullness, sun spots, etc. The sunscreen skin care products prepared by the present invention were used 2-3 times a day, wherein No. 1-20 used the product of Example 1, No. 21-40 used the product of Example 2, No. 41-60 used the product of Example 3, No. 61-80 used the product of Example 4, No. 81-100 used the product of Example 5, and No. 101-120 used the product of Example 6.

[0335] One month after the trial, the comprehensive condition of the subjects' facial skin was assessed, and it was found that no subjects showed any adverse reactions, and their facial skin had improved: redness, swelling, pain, and itching of the skin were repaired; darkened and dull skin became fair and lustrous; sun spots were reduced or disappeared; the skin was no longer dry, tight, or flaky, and became more hydrated and plump.

[0336] Each embodiment in this specification focuses on the differences from other embodiments, and the same and similar parts between the various embodiments can be referred to each other. The above description of the disclosed embodiments enables professionals and technicians in this field to implement or use the present invention. Various modifications to these embodiments will be obvious to professionals and technicians in this field, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown in this article, but will comply with the widest range consistent with the principles and novel features disclosed herein.

[0337] (2) Moisturizing effect

[0338] A saturated calcium chloride solution was prepared and placed in a desiccator to control the humidity at 31%, and the indoor temperature was maintained at 25°C. A layer of medical breathable tape was pasted on the glass plate and its mass was accurately weighed, and then the samples of the embodiments and comparative examples were evenly applied on the surface of the medical breathable tape, weighed, and immediately placed in a desiccator with a saturated calcium chloride solution. After every 2, 4, 6, 8, 10, and 12 hours, the samples were weighed to calculate their water holding capacity, that is, the moisture retention rate. The moisture retention rates of the embodiments and comparative examples over time are shown in FIG. Figure 1 shown.

[0339]

[0340] M t : The mass of the sample after placing th, g; M 0 : The mass of the sample before placement, g.

[0341] Depend on Figure 1 It can be seen that the moisturizing rates of each embodiment and comparative example show a downward trend as time goes by. The order of moisturizing effect is: Example 5> Example 4> Example 6> Example 1> Example 3> Example 2> Comparative Example 6> Comparative Example 5> Comparative Example 2> Comparative Example 3> Comparative Example 1> Comparative Example 4, among which the strongest moisturizing effect is Example 5, followed by Example 4 (both groups contain more natural moisturizers and ingredients with moisturizing effects such as apricot gum, tragacanth gum, gum arabic, xanthan gum, chitosan / collagen / plant essential oil multilayer nanocomposite microsphere emulsion), and the moisturizing effect of Examples 1-6 is proportional to the content of these moisturizing ingredients. The higher the content, the better the moisturizing effect. And the moisturizing rate of each embodiment at 12h is >50%, indicating that each embodiment has a strong moisturizing effect and can keep the skin moisturized and plump for a long time. Comparative Examples 1-6 also have a certain moisturizing effect, but the moisturizing effect of each example is much higher than that of the corresponding comparative example, indicating that the chitosan / collagen / plant essential oil multilayer nanocomposite emulsion has an excellent moisturizing effect.

[0342] (3) Whitening effect

[0343] Tyrosinase is an oxidase and a key enzyme in the formation of melanin. The better the inhibition of tyrosinase, the more obvious the whitening effect. The present invention mainly evaluates the whitening effect of the examples and comparative examples by measuring the inhibition rate of tyrosinase activity. The specific data are as follows:

[0344] The ingredients in the formula of the present invention all have multiple functions, and the ingredients with whitening function include: collagen, carrot seed essential oil, lavender essential oil, camellia oil, wood wax oil, sesame oil, avocado oil, apricot gum, glyceryl glucoside, hydrolyzed collagen, green tea extract, licorice extract, olive leaf extract, safflower extract, lavender extract, ergothioneine, xanthan gum, etc.

[0345] Depend on Figure 2 It can be seen that the order of whitening efficacy is: Example 4> Example 5> Example 6> Example 1> Example 3> Example 2> Comparative Example 6> Comparative Example 5> Comparative Example 2> Comparative Example 4> Comparative Example 3> Comparative Example 1> Vc, among which the strongest whitening efficacy is given to Example 4, followed by Example 5 (both groups contain more whitening ingredients and chitosan / collagen / plant essential oil multilayer nanocomposite microsphere emulsions), and the whitening efficacy of Examples 1-6 is proportional to the content of the whitening ingredients. The higher the content of the whitening ingredients, the higher the inhibition rate of tyrosinase activity, and the better the whitening efficacy. And the inhibition rate of tyrosinase activity in each embodiment is >61%, which is much higher than the positive control Vc, indicating that each embodiment has a very strong whitening efficacy. Comparative Examples 1-6 also have a strong whitening efficacy, which is higher than the positive control Vc, indicating that each comparative example has a strong whitening efficacy. The whitening effect of each example is much higher than that of the corresponding comparative example, indicating that the chitosan / collagen / plant essential oil multilayer nanocomposite emulsion has an excellent inhibitory effect on tyrosinase activity.

[0346] (4) Antioxidant effect

[0347] As people age, they age and develop various skin problems. Skin aging can be delayed by increasing antioxidant activity and promoting cell metabolism. The present invention mainly evaluates the antioxidant activity of the samples of the examples and comparative examples by measuring the total reducing power. The specific data are as follows:

[0348] The ingredients in the formula of the present invention all have multiple functions, and the ingredients with antioxidant effect include: carrot seed essential oil, myrrh essential oil, chamomile essential oil, lavender essential oil, camellia oil, sesame oil, avocado oil, rice bran wax, sugarcane wax, laurel wax, glyceryl glucoside, hydrolyzed collagen, green tea extract, licorice extract, olive leaf extract, safflower extract, lavender extract, ergothioneine, sage extract, black wolfberry extract, mint extract, xanthan gum, bay leaf extract, apricot gum, etc.

[0349] Depend on Figure 3It can be seen that the order of total reducing power is: Example 4> Example 1> Example 6> Example 5> Example 2> Example 3> Comparative Example 4> Comparative Example 6> Comparative Example 2> Comparative Example 5> Comparative Example 1> Comparative Example 3> Vc, among which Example 4 has the strongest total reducing power, followed by Example 1 (both groups contain more antioxidant ingredients and chitosan / collagen / plant essential oil multilayer nanocomposite microsphere emulsion). The strength of the antioxidant effect of Examples 1-6 is proportional to the content of the antioxidant ingredients therein. The higher the content of the antioxidant ingredients, the stronger its total reducing power. Compared with the corresponding Comparative Examples 1-6, Examples 1-6 have a higher total reducing power because the chitosan / collagen / plant essential oil multilayer nanocomposite microsphere emulsion added in the formula also has a strong antioxidant property. Due to the synergistic effect, it has a better antioxidant effect than the corresponding Comparative Examples 1-6.

[0350] (5) Sun protection effect

[0351] Cut the medical breathable tape into strips of 1.0 cm × 4.0 cm, and stick it to one side of the 1.0 cm absorption cell and weigh it accurately. Evenly apply the samples of the embodiment and comparative example on the surface of the tape, and weigh them accurately with a 1 / 10,000 balance, and prepare 3 parallel samples for each sample to be tested; prepare 2 blank absorption cells with medical breathable tape but no sample applied according to the above steps, and place them in the light path as a baseline to adjust the instrument zero point; all the above samples are placed at room temperature (25°C) for 30 minutes to be tested (the transmittance value measured after the sample is applied and placed for 30 minutes to form a film is compared with the direct test value, and the effect is significantly better than the latter and has good reproducibility). Use a UV-visible spectrophotometer to measure the transmittance of the above samples at 280-400nm, and calculate the average value of the measured values ​​of the parallel samples. The results obtained can be used as the sunscreen effect evaluation of the corresponding samples.

[0352] The ingredients in the formula of the present invention all have multiple functions, and the ingredients with sunscreen function include: collagen, carrot seed essential oil, myrrh essential oil, chamomile essential oil, lavender essential oil, camellia oil, wood wax oil, sesame oil, avocado oil, glyceryl glucoside, green tea extract, licorice extract, olive leaf extract, safflower extract, lavender extract, ergothioneine, sage extract, mint extract, xanthan gum, bay leaf extract, apricot gum, gum arabic, etc.

[0353] The wavelength of ultraviolet rays is between 280-400nm. The lower the transmittance, the better the effect of preventing long-wave ultraviolet rays UVA and medium-wave ultraviolet rays UVB, and the higher the sun protection factor. Figure 4It can be seen that the order of light transmittance is: titanium dioxide>zinc oxide>zinc oxide+titanium dioxide>comparative example 3>comparative example 5>comparative example 4>comparative example 2>comparative example 1>comparative example 6>example 2>example 3>example 5>example 6>example 1>example 4, and the strength of the sunscreen effect is inversely proportional to the light transmittance. Therefore, the order of the sunscreen effect is: example 4>example 1>example 6>example 5>example 3>example 2>comparative example 6>comparative example 1>comparative example 2>comparative example 4>comparative example 5>comparative example 3>zinc oxide+titanium dioxide>zinc oxide>titanium dioxide, among which example 4 has the best sunscreen effect, followed by example 1 (both groups contain more chitosan / collagen / plant essential oil multilayer nanocomposite microsphere emulsion and other ingredients with sunscreen effect). The strength of the sunscreen effect of Examples 1-6 is proportional to the content of the sunscreen ingredients therein. The higher the content of the sunscreen ingredients and the chitosan / collagen / plant essential oil multilayer nanocomposite microsphere emulsion, the stronger the sunscreen effect. The transmittance of different sunscreens (zinc oxide, titanium dioxide) in the positive control group is much higher than that of the embodiment, that is, the sunscreen effect of the positive control group is much lower than that of the embodiment, indicating that the sunscreen skin care products prepared by the present invention with the addition of chitosan / collagen / plant essential oil multilayer nanocomposite microsphere emulsion are much stronger than the sunscreen skin care products with the addition of general sunscreens. Compared with the corresponding comparative examples 1-6, Examples 1-6 have better sunscreen effects, because the chitosan / collagen / plant essential oil multilayer nanocomposite microsphere emulsion added in the formula has a strong sunscreen effect, and has more excellent sunscreen performance than the corresponding comparative examples 1-6.

[0354] (6) Waterproof effect

[0355] Net weight method: Soak the cosmetic sample in a certain amount of water for a certain period of time, then take it out and weigh it, and compare the weight difference before and after soaking to evaluate the waterproof performance of the cosmetic. The smaller the weight difference, the better the waterproof performance of the cosmetic. Stick a layer of medical breathable tape on the glass plate and accurately weigh its mass, then evenly apply the example and comparative example samples on the surface of the medical breathable tape, weigh it and put it in a beaker filled with water, and weigh it after 2 hours.

[0356] The ingredients in the formula of the present invention all have multiple functions, and the ingredients with waterproofing function include: chitosan, camellia oil, wood wax oil, rice bran wax, sugarcane wax, sunflower seed wax, laurel wax, apricot gum, tragacanth gum, gum arabic, etc.

[0357] Depend on Figure 5It can be seen that the weight change rate of each embodiment and comparative example sample is in the order of: comparative example 4> comparative example 2> comparative example 5> comparative example 6> comparative example 3> comparative example 1> embodiment 2> embodiment 3> embodiment 6> embodiment 1> embodiment 5> embodiment 4, and the weight change rate is inversely proportional to the waterproof effect. Therefore, the order of the waterproof effect is: embodiment 4> embodiment 5> embodiment 1> embodiment 6> embodiment 3> embodiment 2> comparative example 1> comparative example 3> comparative example 6> comparative example 5> comparative example 2> comparative example 4, among which the best waterproof effect is embodiment 4, followed by embodiment 5 (both groups contain more chitosan / collagen / plant essential oil multilayer nanocomposite microsphere emulsion and other ingredients with waterproof effect). The strength of the waterproof effect of embodiments 1-6 is proportional to the content of the waterproof effect component therein. The higher the content of the waterproof effect component and the chitosan / collagen / plant essential oil multilayer nanocomposite microsphere emulsion, the better the waterproof effect. The waterproof effect of Examples 1-6 is better than that of the corresponding Comparative Examples 1-6, because the chitosan / collagen / plant essential oil multilayer nanocomposite microsphere emulsion added in the formula has a strong waterproof effect and has a better waterproof effect than that of the corresponding Comparative Examples 1-6.

[0358] The above-mentioned embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present invention shall fall within the scope of protection required by the present invention.

Claims

1. A method for preparing a chitosan skin care composition, characterized in that: The steps include: S1 Dispersed Collagen Disperse collagen in an acetic acid solution with a mass fraction of 1% to 3%, stir at room temperature until completely dissolved, and continue stirring for 10 to 15 minutes to evenly disperse the collagen in the acetic acid solution to obtain a collagen solution; S2 collagen wrapped with plant essential oil The prepared collagen solution and natural plant essential oil were added into a beaker in a volume ratio of 5:1 to 10:1, and dispersed for 3 to 5 minutes at a speed of 10000 r / min to 15000 r / min using a high-speed disperser, and the upper white emulsion was washed with deionized water until neutral to obtain collagen / plant essential oil microsphere A emulsion; S3 Dispersed Chitosan Disperse chitosan in an acetic acid solution with a mass fraction of 1% to 3%, stir at room temperature until completely dissolved, and continue stirring for 10 to 15 minutes to evenly disperse the chitosan in the acetic acid solution to obtain a chitosan solution; S4 Chitosan Encapsulated Microspheres A Emulsion The prepared collagen / plant essential oil microsphere A emulsion and chitosan solution are added into a beaker in a volume ratio of 5:5 to 1:5 and stirred evenly. The mixture is dispersed at a speed of 10000 to 15000 r / min for 3 to 5 minutes using a high-speed disperser. The upper white emulsion is washed with deionized water until it is neutral to obtain a chitosan / collagen / plant essential oil multilayer nanocomposite microsphere B emulsion. S5 added oil wax ingredients Add natural vegetable oil and natural vegetable wax into a beaker, heat in a water bath at 75-85°C and stir evenly until completely melted to obtain solution C; S6 adds various ingredients Take the natural moisturizer and add it to deionized water, stir it evenly at room temperature until it is completely dissolved; then add natural plant extracts, natural antioxidants, and natural preservatives. Stir evenly at room temperature until completely dissolved to obtain solution D; S7 Emulsification Take a natural emulsifier and add it to deionized water, stir it evenly at room temperature until it is completely dissolved; then add chitosan / collagen / plant essential oil multilayer nanocomposite microsphere B emulsion, solution C, solution D, and the remaining water, stir it evenly at room temperature until it is completely emulsified, and then obtain a sunscreen skin care product.

2. The method for preparing the chitosan skin care composition according to claim 1, characterized in that: The mass fraction of the collagen solution in step S1 is 5% to 20%; the mass fraction of the chitosan solution in step S3 is 5% to 30%.

3. The method for preparing the chitosan skin care composition according to claim 2, characterized in that: The preparation method of chitosan in step S3 comprises the following steps: S3-1 Fermentation After washing the shrimp heads, shells and tails to remove impurities, the shrimp by-products were crushed with a high-pressure homogenizer for 30 minutes to obtain shrimp by-product powder with a particle size of less than 100 μm; the shrimp by-product powder, water, glucose and lactic acid bacteria were mixed in a mass ratio of 1:15:1:1, and fermented at 38-40°C for 36-40 hours; trypsin was added to make its concentration reach 1-2 g / L; alkaline protease was added to make its concentration reach 2-3 g / L; enzymolysis was performed at 40-50°C for 6-10 hours; S3-2 Crude Purification After enzymatic hydrolysis, the product is filtered to obtain a precipitate, and the protein and peptides and amino acids after enzymatic hydrolysis are in the filtered supernatant, thereby removing the protein; the precipitate, water, and citric acid are mixed in a mass ratio of 5:20:2, and the temperature is raised to 60-70° C., stirred for 2-4 hours, and filtered to obtain a crude chitosan product, and calcium salts such as calcium carbonate are hydrolyzed by citric acid to remove the calcium salts in the chitosan; the crude chitosan product is washed with amyl alcohol to remove the pigment; S3-3 deacetylation The crude chitosan, water, sodium hydroxide and amyl alcohol are mixed in a mass ratio of 1:20:12:4, and treated at 60-80° C. for 30-35 hours; and deacetylated chitosan precipitate is obtained by filtration; S3-4 Refining and Purification The deacetylated chitosan precipitate is dissolved in an acetic acid aqueous solution with a mass fraction of 3-5%, and ultrafiltration and dialysis are performed using an ultrafiltration membrane package with a pore size of 40,000 Daltons, and chitosan with a molecular weight less than 40,000 Daltons passes through the membrane package and is separated from chitosan with a molecular weight greater than 40,000 Daltons, and a permeate A is collected, and the molecular weight of chitosan in the permeate A is less than 40,000 Daltons; the permeate A is treated by ultrafiltration and dialysis using an ultrafiltration membrane package with a pore size of 20,000 Daltons, and chitosan with a molecular weight less than 20,000 Daltons passes through the membrane package and is separated from chitosan with a molecular weight greater than 20,000 Daltons; and chitosan with a molecular weight of 20,000-40,000 Daltons in a reflux liquid B is collected; S3-5 Drying The reflux liquid B is dried to obtain chitosan, wherein the chitosan has the following characteristics: the molecular weight of the chitosan is 20,000 to 40,000 Daltons, and the degree of deacetylation is greater than 95%.

4. The method for preparing the chitosan skin care composition according to claim 3, characterized in that: The natural plant essential oil is any one or more mixtures of carrot seed essential oil, myrrh essential oil, chamomile essential oil and lavender essential oil.

5. The method for preparing the chitosan skin care composition according to claim 4, characterized in that: The natural plant oil is any one or more mixtures of camellia oil, wood wax oil, sesame oil and avocado oil; the natural emulsifier is any one or a mixture of apricot gum, tragacanth gum and gum arabic.

6. The method for preparing the chitosan skin care composition according to claim 4, characterized in that: The natural plant wax is any one or more mixtures of rice bran wax, sugarcane wax, sunflower seed wax and laurel wax; the natural plant extract is any one or a mixture of green tea extract, licorice extract, olive leaf extract, safflower extract and lavender extract.

7. The method for preparing the chitosan skin care composition according to claim 5, characterized in that: The natural moisturizing agent is any one or more mixtures of glycerol glucoside, hydrolyzed collagen and urea.

8. The method for preparing the chitosan skin care composition according to claim 7, characterized in that: The natural preservative is any one of peppermint extract, xanthan gum, and bay leaf extract, or a mixture thereof.

9. The method for preparing the chitosan skin care composition according to claim 8, characterized in that: The natural antioxidant is any one of ergothioneine, sage extract, black wolfberry extract or a mixture thereof.

10. The chitosan skin care composition according to claim 1, characterized in that: It includes 10% to 25% by mass of chitosan / collagen / plant essential oil multilayer nanocomposite microsphere B emulsion, 4% to 6% by mass of natural plant oil, 5% to 6% by mass of natural plant wax, 5% to 7% by mass of natural moisturizer, 3% to 5% by mass of natural plant extract, 3% to 6% by mass of natural antioxidant, 3% to 5% by mass of natural preservative, 1.5% to 2% by mass of natural emulsifier, and the balance is water.

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