CN120815007B

CN120815007B - A method for preparing lignin-coated zinc oxide composite nanoparticles, its products and applications

Info

Publication number: CN120815007B
Application number: CN202511320008.0A
Authority: CN
Inventors: 刘楠; 丁赟
Original assignee: Hangzhou Island Xingqing Biotechnology Co ltd
Current assignee: Hangzhou Island Xingqing Biotechnology Co ltd
Priority date: 2025-09-16
Filing date: 2025-09-16
Publication date: 2026-01-13
Anticipated expiration: 2045-09-16
Also published as: CN120815007A

Abstract

The invention discloses a preparation method of lignin coated zinc oxide composite nano particles, a product and application thereof, belonging to the technical field of chemical product preparation, comprising the steps of adding lignin powder into alkali solution to obtain lignin powder suspension, slowly dropwise adding zinc salt solution, regulating the pH value to 9.0-12.0, performing hydrothermal reaction under nitrogen atmosphere, centrifugally collecting precipitate, and washing to obtain the raspberry-shaped lignin-coated zinc oxide composite nano particles. The composite nano particles disclosed by the invention show a raspberry-shaped rough surface, increase friction force, have certain rigidity, improve cleaning effect, have more excellent ultraviolet shielding performance and oxidation resistance, enable the composite nano particles to effectively relieve scalp inflammation and prevent ultraviolet damage of hair, and simultaneously endow the composite particles with excellent antibacterial performance, so that the growth of fungi such as malassezia is effectively inhibited, and the generation of dandruff is reduced.

Description

Preparation method of lignin coated zinc oxide composite nano particles, product and application thereof

Technical Field

The invention belongs to the technical field of chemical product preparation, and particularly relates to a preparation method of lignin-coated zinc oxide composite nano particles, a product and application thereof.

Background

Hair cleansing and scalp care are important issues in the public health area. Hair health and dandruff problems significantly affect the daily life of an individual. Dandruff is produced mainly due to the fact that the excess sebum secretion, the excess secretion of scalp grease, provides a suitable growth environment for the fungi, thus stimulating the production of dandruff. Scalp inflammation, a variety of inflammatory scalp disorders such as eczema and psoriasis, are associated with increased dandruff. These inflammatory reactions not only cause discomfort to the scalp, but may also lead to disruption of the skin barrier function, thereby exacerbating the dandruff problem. Bacterial and fungal infections malassezia globosa (m. Globosa) and malassezia limiter (m. Restricta) are associated with dandruff and seborrheic dermatitis, and when their numbers are out of control, they may lead to increased dandruff. Currently, the components with wider application range mainly comprise zinc pyrithione, piroctone olamine salt, selenium disulfide and the like, but the components can irritate scalp, seriously cause contact dermatitis and lead to dry and frizzy hair.

Lignin is widely present in the cell wall of natural plants, the second largest natural macromolecule next to cellulose, which has excellent biocompatibility, broad-spectrum uv protection, oxidation resistance, antibacterial properties, and the like. The structure of the skin-cleaning agent contains rich phenolic hydroxyl groups, carbonyl groups, unsaturated double bonds, conjugated structures and other special structures, so that the skin-cleaning agent can interact with dirt through hydrogen bonds, van der Waals force, wetting action and the like, and the effect of removing skin dirt is achieved. However, lignin has problems of poor dispersibility, heavy color, weak antibacterial activity, insufficient rigidity and the like, and is difficult to be directly used as a functional auxiliary agent of the scalp cleaning product.

Therefore, how to apply lignin to the washing and caring articles and improve the efficacy of lignin is a technical problem to be solved.

Disclosure of Invention

The invention aims to provide an antibacterial anti-dandruff sun-screening component, which is composite particles composed of lignin and zinc oxide, wherein the introduction of the zinc oxide can effectively enhance the antibacterial property of the lignin, simultaneously provide a certain rigidity, and promote the friction force of the composite particles, thereby effectively removing dirt. In addition, the composite particles can be used as an additive of a shampoo product to effectively inhibit dandruff, clean scalp and relieve inflammation. The method is simple, convenient and quick, low in cost, mild in reaction condition and good in application value.

As one aspect of the invention, the invention provides a preparation method of lignin-coated zinc oxide composite nano particles, which comprises the following steps,

Adding lignin powder into an alkali solution to obtain lignin powder suspension, slowly dropwise adding zinc salt solution, adjusting the pH to 9.0-12.0, performing hydrothermal reaction in a nitrogen atmosphere, centrifugally collecting precipitate, and washing to obtain the raspberry-shaped lignin coated zinc oxide composite nano particles.

As a preferable scheme of the preparation method of the lignin-coated zinc oxide composite nano particle, the lignin comprises enzymatic hydrolysis lignin.

As a preferable scheme of the preparation method of the lignin-coated zinc oxide composite nano particle, the zinc salt is at least one of zinc nitrate, zinc acetate, zinc sulfate, zinc chloride and zinc nitrite.

As a preferable scheme of the preparation method of the lignin-coated zinc oxide composite nano particle, the mass ratio of lignin to zinc salt is 0.5-2.0:1.

As a preferable scheme of the preparation method of the lignin-coated zinc oxide composite nano particle, the hydrothermal reaction temperature is 80-120 ℃ and the time is 6.0-12.0 h.

The preparation method of the lignin-coated zinc oxide composite nanoparticle has the preferable scheme that the concentration of the lignin powder suspension is 0.01-0.015 g/mL, and the concentration of the zinc salt solution is 0.1-0.2 g/mL.

As a preferable scheme of the preparation method of the lignin-coated zinc oxide composite nano particle, the alkali solution comprises sodium hydroxide solution.

The invention also provides application of the lignin-coated zinc oxide composite nano particles prepared by the preparation method of the lignin-coated zinc oxide composite nano particles in preparation of cosmetics.

Wherein, the lignin coated zinc oxide composite nano particles are used for preparing scalp care agents, hair conditioners, scalp cleaners or shampoos.

The scalp care agent comprises, by mass, 5% -25% of lignin-coated zinc oxide composite nano particles, 10% -25% of surfactants, 2% -5% of conditioning agents, 0.05% -0.15% of emulsifying agents, 10% -30% of emollients, 0.01% -0.3% of preservatives, 0% -0.8% of essence, 0.5% -1% of viscosity regulators, 0.05% -0.2% of chelating agents, 0.001% -0.2% of pH regulators, 10% -25% of humectants and the balance of water.

Preferably, the surfactant is at least one of sodium laureth sulfate, ammonium laureth sulfate, sodium lauroyl amphoacetate, cocamide MEA, cocamidopropyl betaine, behenamidopropyl dimethylamine, trideceth-10, trideceth-3, oxidized polyethylene lauric acid and sodium polynaphthalenesulfonate, and has a cleaning effect in the components.

Preferably, the conditioning agent is at least one of glycol distearate, maleic acid modified castor oil, polyquaternium-10, dipalmitoyl oxyethyl dimethyl ammonium chloride, oleamide propyl PG-dimethyl ammonium chloride, guar gum hydroxypropyl trimethyl ammonium chloride, amino end polydimethylsiloxane, serine and cocoyl dimethyl ammonium hydroxypropyl hydrolytic collagen, and plays a role in removing dandruff and resisting static in the components.

Preferably, the emulsifier is at least one of cetrimide, propylene glycol fatty acid ester, sucrose fatty acid ester and polyglycerol fatty acid ester, and has the function of stabilizing oil-soluble components.

Preferably, the emollient is at least one of butter fruit, coconut oil, mango seed oil, serine, glycerol, propylene glycol, ethylene glycol distearate, glyceryl stearate.

Preferably, the preservative is at least one of piroctone olamine salt, phenoxyethanol, cetrimide, phenoxyethanol, and paraben.

Preferably, the humectant is at least one of glycerin, propylene glycol, dipropylene glycol, and pentanediol.

Preferably, the chelating agent is EDTA-disodium.

Preferably, the flavour is vanillin.

Preferably, the viscosity modifier is sodium chloride.

The invention has the beneficial effects that:

(1) The invention provides an antibacterial, anti-dandruff and sun-screening component, which is composite particles assembled by combining lignin serving as a precursor with zinc oxide through a hydrothermal method, wherein on one hand, the lignin has an amorphous three-dimensional structure and rich surface groups, and can form stable particles with the zinc oxide particles through hydrogen bonding and electrostatic interaction, so that the prepared composite particles are suitable in particle size, uniform in particle size distribution, migration-resistant and light in color. On the other hand, the composite particles effectively adsorb dirt through hydrogen bonding, van der Waals force and wetting action, and at the same time, they exhibit a rough surface in a shape of raspberry, increase friction force, have a certain rigidity, and improve cleaning effect.

(2) The composite particles have more excellent ultraviolet shielding performance and oxidation resistance, so that scalp inflammation can be effectively relieved, ultraviolet damage of hair can be prevented, and meanwhile, excellent antibacterial performance is provided for the composite particles, and growth of fungi such as malassezia can be effectively inhibited, so that dandruff is reduced.

(3) The invention selects the natural biomass lignin with wide sources, low cost and easy obtainment as the precursor, simply, conveniently and quickly prepares the composite nano particles with stable size, excellent antibacterial and anti-ultraviolet performance and oxidation resistance (anti-inflammation), and solves the problems of poor utilization of lignin raw materials, difficult dispersion, deep color, difficult regulation of the size and the shape of the lignin-zinc oxide composite particles and the like. Meanwhile, the lignin coated zinc oxide composite particles prepared by the method adopt water and glycerol as solvents, and compared with the traditional organic solvents for dissolving lignin, the lignin coated zinc oxide composite particles have the advantages of simplicity and convenience in preparation, green and non-toxic products, high yield and the like, and are suitable for large-scale production.

(4) The antibacterial and anti-dandruff component provided by the invention has the particle size of more than 100 nm, can not permeate into organism tissues, has certain rigidity and rough surface, and can not scratch skin while enhancing the cleaning force. The introduction of zinc oxide promotes the antibacterial property of the composite particles, thereby inhibiting the growth and reproduction of bacteria and effectively reducing the generation of dandruff. In addition, the lipophilicity, oxidation resistance and ultraviolet shielding performance of lignin are also beneficial to the removal of skin grease, the alleviation of scalp inflammation and the prevention of ultraviolet damage to hair.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the description of the embodiments will be briefly described below, in which:

FIG. 1 is a graph of the microscopic morphology of example 2 lignin-coated zinc oxide nanocomposite particles.

Fig. 2 is an SEM image of the product of comparative example 1.

FIG. 3 is a statistical plot of the particle size distribution of the product of example 3.

FIG. 4 is a thermal weight graph of lignin-coated zinc oxide composite particles, where the right hand label is the zinc oxide loading of each sample.

FIG. 5 is a photograph of the product of example 4 formulated as an aqueous dispersion having a concentration of 15 wt%.

Detailed Description

In order that the above-recited objects, features and advantages of the present invention will become more apparent, a more particular description of the invention will be rendered by reference to specific embodiments thereof.

The various materials of the present invention are commercially available unless specifically indicated.

Mixing a sample with a polyvinyl alcohol (PVA) aqueous solution (10% w/v), pouring a PVA composite film with uniform thickness (the content of lignin coated zinc oxide composite particles in the PVA composite film is 1 wt%), and testing the absorbance at a position of 320: 320 nm by using an ultraviolet spectrophotometer;

free radical self-cleaning measurement, namely preparing lignin coated zinc oxide composite particles into an aqueous suspension (0.05 g/mL) by taking ZnO dispersion liquid (0.05 g/mL) as a blank control, and detecting the free radical scavenging capacity by DPPH free radicals;

Composite particle migration amount measurement, namely, preparing water/ethanol (9:1 v/v) as a simulation solution, placing the PVA composite film of 1.0 g into the 20 g simulation solution, standing for 48 and h, taking out the film, and measuring the migration amount (mg) of the lignin-coated zinc oxide composite particles in the PVA composite film.

Antibacterial performance test, namely selecting gram positive bacteria (staphylococcus aureus) and gram negative bacteria (escherichia coli) as target strains, and adopting a bacterial colony counting method to characterize the bacteria. Preparation of bacterial liquid, namely ten-fold gradient dilution of the activated bacterial liquid to the concentration of 1X 10 ⁵ CFU/mL by using sterile PBS, sample treatment, namely preparing the composite nano particles into 50 mg/mL dispersion by using PBS, mixing the 1mL dispersion with 1mL bacterial liquid to perform shaking culture at 37 ℃ and 200 rpm for 3 h, plate culture, namely uniformly coating 50 mu L of culture liquid on an LB agar plate, culturing at 37 ℃ for 24: 24 h, counting surviving colonies, and replacing the sample solution by using an equal volume of PBS buffer (pH=7.4) in a control group, wherein the antibacterial rate (A) is calculated by a formula (3-1):

N _control and N _sample in the formula represent colony numbers of the culture medium of the control group and the sample group respectively

And (3) evaluating the sun-screening capability, namely mixing the lignin-coated zinc oxide composite nano particles with blank cream (infant moisturizing facial cream) without sun-screening active ingredients according to the mass ratio of 1:10 to prepare the ultraviolet sun-screening agent sun-screening cream. The ability of the composite particles to prevent uv damage was assessed by measuring the SPF value of the composite sunscreen.

The test method comprises selecting two areas on the back of the tested person, wherein one area is coated with the sample, and the other area is not protected. Then, the two areas are simultaneously exposed to ultraviolet radiation with the same intensity (since the two areas receive the same ultraviolet radiation intensity, the minimum erythema dose required for generating the minimum erythema is proportional to the irradiation time), the SPF value of the sample can be obtained by recording the time division of the erythema generated by the two areas, and the detection results are shown in Table 1.

Example 1:

Screening micron-sized enzymolysis lignin powder (LMP) through a screen with a screen mesh size of 140 meshes (aperture of 106 mu m) after grinding the enzymolysis lignin, slowly adding 4g enzymolysis lignin powder into a NaOH solution of 0.05 mol/L and 300 mL under stirring to fully dissolve the enzymolysis lignin powder (LMP) suspension, slowly dropwise adding 4g zinc acetate (dissolved in 40 mL water) into the enzymolysis lignin powder (LMP) suspension under stirring, regulating the pH value to 12 by NaOH, transferring the mixture into a flask, reacting at 90 ℃ under nitrogen atmosphere for 6h, centrifuging 30min by using a centrifuge 9000 rpm after the reaction is completed, collecting a precipitate product, replacing supernatant by distilled water, and repeating the centrifugation operation for three times to obtain the raspberry-shaped lignin coated zinc oxide composite nano particles. Wherein, the enzymatic lignin (LIG-I type) is purchased from Shandong Longli Biotechnology Co., ltd.

Example 2:

referring to example 1, the hydrothermal reaction time was changed to 9 h only, and the remaining conditions were unchanged.

Example 3:

referring to example 1, the hydrothermal reaction time was changed to 12 h only, and the remaining conditions were unchanged.

Example 4:

Referring to example 3, the hydrothermal reaction temperature was changed to 120 ℃ only, and the remaining conditions were unchanged. FIG. 5 is a photograph of the product of example 4 formulated as an aqueous dispersion having a concentration of 15 wt%.

Example 5:

referring to example 3, the hydrothermal reaction temperature was changed to 60 ℃ only, and the remaining conditions were unchanged.

Example 6:

referring to example 3, only the pH of the mixture of zinc acetate and the enzymatic lignin powder (LMP) suspension was changed to 11, and the remaining conditions were unchanged.

Example 7:

Referring to example 3, only the pH of the mixture of zinc acetate and the enzymatic lignin powder (LMP) suspension was changed to 13, and the remaining conditions were unchanged.

Example 8:

referring to example 3, the amount of zinc acetate added was changed to 8 g, and the other conditions were unchanged.

Example 9:

referring to example 3, the amount of zinc acetate added in the step was changed to 2 g, and the remaining conditions were unchanged.

Comparative example 1:

screening micron-sized enzymolysis lignin powder (LMP) through a screen with a screen mesh size of 140 meshes (aperture of 106 mu m) after grinding the enzymolysis lignin, slowly adding 4g the enzymolysis lignin powder into a NaOH solution of 0.05mol/L and 300 mL under stirring to fully dissolve the enzymolysis lignin powder (LMP) to obtain enzymolysis lignin powder (LMP) suspension, regulating the pH to 12 by NaOH, transferring the suspension into a flask, reacting at 90 ℃ under the nitrogen atmosphere for 12 h, centrifuging 30min by using a centrifuge 9000 rpm after the reaction is completed, collecting a precipitated product, and repeating the centrifugation operation for three times to obtain the product.

Comparative example 2:

The enzymatically hydrolyzed lignin is ground and then screened through a sieve having a mesh size of 140 mesh (pore size 106 μm) to obtain a micron-sized enzymatically hydrolyzed lignin powder. The enzymatic lignin powder (4 g) was slowly added (0.05 mol/L,300 mL) to the NaOH solution under stirring to dissolve thoroughly. Slowly adding 4g nm zinc oxide (average particle size is 50+/-10 nm) into LMP suspension under stirring, adjusting pH to 12 with NaOH, transferring to a flask, reacting at 90 ℃ under nitrogen atmosphere for 12 h, centrifuging 30min by using a centrifuge 9000 rpm after the reaction is completed, collecting a precipitate, replacing supernatant with distilled water, and repeating the centrifugation operation for three times to obtain the lignin zinc oxide composite nano particles.

Comparative example 3:

The dealkalized lignin is ground, and then micron-sized dealkalized lignin powder (LMP) is screened through a screen with a mesh size of 140 meshes (pore diameter of 106 μm), and 4 g of the dealkalized lignin powder is slowly added into NaOH solution (0.05 mol/L,300 mL) under stirring to be fully dissolved. Slowly dropwise adding 4 g zinc acetate (dissolved in 40 mL water) into an alkali-removed lignin powder (LMP) suspension under stirring, adjusting the pH to 12 with NaOH, transferring to a flask, reacting at 90 ℃ under nitrogen atmosphere for 12 h, centrifuging 30 min by using a centrifuge 9000 rpm after the reaction is completed, replacing the supernatant with distilled water, and repeating the centrifugation operation for three times to obtain the lignin zinc oxide composite nano particles.

TABLE 1 comparison of the Properties of Lignin-coated Zinc oxide composite nanoparticles prepared according to the invention

FIG. 1 is a graph showing the microscopic morphology and particle size distribution of zinc oxide/lignin nanoparticles prepared by the method of the present invention in example 2. From the figure, the lignin-coated zinc oxide composite nano particles are in a multidirectional raspberry shape, the lignin nano particles are wrapped on the periphery of the zinc oxide, the lignin nano particles and the zinc oxide are combined through hydrogen bonding and electrostatic action, when the acting force is greater than the strong base or strong acid destructive force, the lignin-coated zinc oxide composite nano particles can be formed, the lignin zinc oxide is uniformly combined, the particle size of the lignin-coated zinc oxide composite particles is uniform, more than 90% of the particle sizes are greater than 200 nm, and the overall particle size distribution is uniform (D50#372 nm). FIG. 3 is a graph showing the particle size distribution of lignin-coated zinc oxide composite nanoparticles in example 3. Comparing example 2 with example 3, it can be seen that with the increase of the reaction time, the lignin and zinc oxide are more fully combined, the shape of the lignin coated zinc oxide composite nano particle is more plump, the particle size is increased, the zinc oxide loading capacity is improved, and the particle size distribution is more concentrated.

Examples 1-8 explore the effects of morphology and physical properties of composite nanoparticles by changing reaction time, reaction temperature, zinc salt content and reaction pH, and the core is to regulate hydrogen bond and electrostatic force between lignin and zinc salt, lignin is soluble in alkaline environment, zinc salt acts as a nucleating agent in lignin self-assembly process in crystal formation process, nano lignin and nano zinc oxide co-grow, lignin is effectively coated on zinc oxide surface, and raspberry-shaped structure is formed. From the above results, it can be seen that, since lignin and zinc oxide have antibacterial and anti-ultraviolet functions, the composite nanoparticle can effectively inhibit bacterial growth and exhibit excellent anti-ultraviolet functions, and 320 nm ultraviolet transmittance decreases with increasing ZnO content to only 0.1%. Meanwhile, the migration quantity of the composite particles is low, and the nano toxicity is greatly reduced. In comparative example 2, nano lignin and nano zinc oxide are added respectively, hydrogen bond or electrostatic bonding capability of the nano lignin and the nano zinc oxide is weak, meanwhile, the lignin is in a dissolved state at a pH value of 12, the nano zinc oxide cannot be used as a nucleating agent in the processes of lignin self-assembly and growth, so that effective coating on zinc oxide is difficult to form, in comparative example 3, acting force between dealkalized lignin and zinc salt is weak, so that effective coating on zinc oxide is difficult to form, and zinc oxide with uneven particle size distribution is easy to migrate. Examples 6 and 7 explore the influence of different pH values on the morphology of nanoparticles, when the pH=13, lignin is sufficiently dissolved, and when zinc oxide is precipitated, lignin is difficult to precipitate at the same time, so that the particle size of the composite particles is smaller, and the morphology is not full. Examples 8 and 9 explore the influence of different zinc salt and lignin ratios on the performance of nanoparticles, when the zinc salt is 8g, the content of formed zinc oxide is improved, the binding sites of lignin and zinc oxide are increased, so that the content of formed composite nano particle zinc oxide is also greatly improved to 80.2%, but the efficiency of generating active oxygen free radicals after the lignin captures ZnO stimulated by ultraviolet light is reduced.

The products prepared in examples 3, 5, 7 and 8 and comparative examples 1 and 2 are used as antibacterial and anti-dandruff active ingredients and added into scalp cleaning and nursing agents shown in each application example according to the corresponding mass percent, and the addition amounts of the components in the scalp cleaning and nursing agents in each application example are shown in table 2, and the preparation method is that the raw materials of the formula are uniformly mixed.

TABLE 2 scalp cleaning care agent (wt%) prepared by the present invention

The scalp cleaning care agents prepared in application examples 1-6 and application comparative examples 1-2 are subjected to evaluation test, 10 evaluators are selected, each index is scored by 0-10 score from low to high in sensory intensity, 1 g+/-0.1 g of each sample is taken and circularly smeared on the inner side of the forearm, and after 20 circles of the sample are smeared, the easy push-open degree (0 is easy to spread and 10 is difficult to spread) and the stinging sensation (0 is hardly mechanical friction and 10 is stinging sensation caused by friction) are evaluated. Simultaneously, 5 men from 18-60 years old male volunteers, suffering from dandruff and scalp inflammation, were selected. The scalp care agent obtained in application examples 1-6 or application comparative examples 1-2 was used twice a week by each group of volunteers, and the use method was that after the hair was wetted, 3g + -0.5 g scalp care agent was placed near the root of the hair, spread out with the abdomen of the finger, massaged 5min, then washed with clear water, and then rinsed according to the daily hair washing habit of the individual. The evaluation was performed after continuous use for 1 month and the results (dandruff, scalp itching, hair frizziness) were counted, and the results are shown in Table 3.

Table 3 scalp care agent with different ratios and use effect

It is noted that the significant improvement of dandruff is a significant reduction, the itchy scalp inflammation problem is eliminated, the improvement is a reduction of the dandruff, the occurrence frequency of itchy scalp is reduced, the number of acnes is reduced, and the ineffectiveness is no change in the itchy scalp inflammation problem.

It should be noted that the above embodiments are only for illustrating the technical solution of the present invention and not for limiting the same, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solution of the present invention may be modified or substituted without departing from the spirit and scope of the technical solution of the present invention, which is intended to be covered in the scope of the claims of the present invention.

Claims

1. The application of the lignin-coated zinc oxide composite nano particle in preparing cosmetics is characterized in that the lignin-coated zinc oxide composite nano particle is used for preparing scalp care agents, hair conditioners, scalp cleaners or shampoos,

The preparation method of the lignin coated zinc oxide composite nano particle comprises the following steps,

Grinding the enzymolysis lignin, passing through a screen with a mesh size of 140 meshes, slowly adding 4g enzymolysis lignin powder into a NaOH solution of 0.05 mol/L and 300 mL under stirring to fully dissolve the enzymolysis lignin powder suspension, dissolving 4g zinc acetate into 40 mL water under stirring, slowly dripping the zinc acetate into the enzymolysis lignin powder suspension, regulating the pH value to 12 by NaOH, transferring the solution into a flask, reacting the solution with the solution at the temperature of 90 ℃ under the nitrogen atmosphere for 12 h, centrifuging the solution with a centrifuge 9000 rpm for 30 min after the reaction is finished, collecting a precipitate product, replacing supernatant with distilled water, and repeating the centrifugation operation for three times to obtain the raspberry-shaped lignin coated zinc oxide composite nano particles;

the enzymatic hydrolysis lignin is LIG-I type enzymatic hydrolysis lignin.

2. The application of the scalp care agent according to claim 1, wherein the scalp care agent comprises, by mass, 5% -25% of lignin-coated zinc oxide composite nano particles, 10% -25% of surfactants, 2% -5% of conditioning agents, 0.05% -0.15% of emulsifying agents, 10% -30% of emollients, 0.01% -0.3% of preservatives, 0% -0.8% of essence, 0.5% -1% of viscosity regulators, 0.05% -0.2% of chelating agents, 0.001% -0.2% of pH regulators, 10% -25% of moisturizers and the balance of water.