A non-sensitive high-efficiency air purifying agent and its application

Abstract

The application discloses a non-allergic high-efficiency air purifying agent, which comprises the following raw materials in parts by weight: D-limonene 20-30 parts, sesquiterpene organic matter 1-5 parts, tea polyphenol 1-5 parts, carbonate 50-70 parts and emulsifier 5-10 parts. The non-allergic high-efficiency air purifying agent prepared by the application is atomized and dispersed in air for use. The application simplifies the raw material formula of the air purifying agent, still maintains good deodorization effect, reduces production cost, and has no allergic or irritating reaction to the skin.

Description

Technical Field

[0001] This invention belongs to the field of deodorization technology, specifically relating to a hypoallergenic, high-efficiency air purifier and its application. Background Technology

[0002] Common sources of odors include: 1. Odors from organic fertilizer production; 2. Odors from animal manure during livestock farming; 3. Odors from food processing waste; 4. Odors from stagnant water bodies; 5. Odors from building septic tanks, public toilets, and home bathrooms; 6. The smell of fermenting and rotting kitchen waste; 7. Formaldehyde odors from new houses and cars; 8. Smoke odors and other odors from old cars; 9. Odors from clothes and shoes.

[0003] Deodorants are cleaning products used to remove odors from a local space. They mainly come in the following types: physical deodorants, chemical deodorants, microbial deodorants, and plant-based deodorants.

[0004] Physical deodorizers remove odors through physical methods. They utilize the physical properties of the deodorizer or the odor gas itself, changing only its local or relative concentration without altering the gas composition. Common types include adsorption deodorizers and masking deodorizers. Adsorption deodorizers use substances with excellent adsorption capabilities to adsorb odor molecules into porous materials using intermolecular van der Waals forces. These deodorizers have a large specific surface area and large pore volume, typically reducing the concentration of odors in the air through adsorption. Common adsorption deodorizers include activated carbon and diatomaceous earth. Masking deodorizers, on the other hand, use natural aromatic oils and fragrances to mask odors. They are primarily used for stubborn odors or in environments where deodorization is difficult, by mixing several odorous gases in a specific ratio to reduce the odor. Air fresheners are a common example.

[0005] Chemical deodorizers eliminate odors by using oxidation, reduction decomposition, neutralization, addition, condensation, and ion exchange reactions to transform odor-causing substances into odorless substances.

[0006] The basic principle of microbial deodorizers is to utilize microorganisms to absorb odor substances dissolved in water into their own bodies, and then degrade them through the metabolic activities of the microorganisms. Microbial deodorization can be divided into three stages: ① the dissolution process of odor gases, that is, the transfer from the gas phase to the liquid phase; ② the adsorption and absorption of odor components in the aqueous solution by microorganisms; ③ the odor components that enter the microbial cells are decomposed and utilized by the microorganisms as nutrients, thereby removing pollutants.

[0007] Plant-based deodorizers utilize plant extracts to remove odors. Currently available plant-based deodorizers are limited to removing common odors such as ammonia, hydrogen sulfide, and methanethiol, and are ineffective against carcinogenic gases like formaldehyde and benzene. Furthermore, most disclosed plant-based deodorizers employ traditional distillation extraction methods, resulting in lower purity and a crude purification process that damages some active ingredients (such as active enzymes). Consequently, the deodorizing effect of plant-based deodorizers is often less than ideal, exhibiting significant fluctuations.

[0008] The aforementioned deodorizers each have the following drawbacks: physical deodorizers require a long time to deodorize and their effects are not obvious, especially after their adsorption capacity approaches saturation, at which point the deodorizing effect worsens, requiring frequent replacement; chemical deodorizers have the disadvantage that some products are corrosive or toxic, limiting their use. Microbial deodorizers have a long deodorizing time, and the activity level of the biological enzymes has a significant impact on the deodorizing effect. Plant-based deodorizing products, while having a more complex production process and higher product cost, offer deodorizing effects comparable to chemical deodorizers. In a sense, they represent an upgrade from chemical deodorizing products.

[0009] Chinese patent CN107303461A discloses a method for preparing a traditional Chinese medicine extract for rapid formaldehyde removal, comprising honeysuckle, agastache rugosa, Dryopteris crassirhizoma, Atractylodes lancea, Isatis indigotica, Perilla frutescens, Artemisia argyi, Artemisia annua, Citrus reticulata peel, Platycodon grandiflorus, and peppermint. This invention is a pure traditional Chinese medicine formula, avoiding the irritation of human skin and mucous membranes by other chemical components, and leaving no harmful residues after use. The preparation method is simple and easy to promote, involving extraction, mixing, and fermentation. The diluted extract can be directly sprayed, making it highly operable.

[0010] Chinese patent CN108671753A discloses a formaldehyde removal and purification agent, which is made from more than 20 kinds of pure natural Chinese herbal plants, including Ailanthus altissima, orange peel, lavender, Platycladus orientalis leaves, Pseudolarix amabilis leaves, Artemisia argyi, cinnamon, and Phellodendron amurense leaves. It is formulated and refined using different low-temperature cold extraction and fermentation methods. Based on the characteristics of the organic components of the roots, stems, leaves, and fruits of these plants, the roots are extracted using traditional boiling methods, the leaves using cold extraction methods, and the fruits using cell wall breaking methods. The plant extracts obtained by different methods are thoroughly mixed and processed into the finished product using a special low-temperature, high-efficiency fermentation process. The beneficial effects of this invention are: This formaldehyde removal and purification agent is suitable for removing formaldehyde from our living environment, and has the functions of removing formaldehyde, sterilizing, deodorizing, and purifying the air, with a formaldehyde removal rate of up to 91.0%.

[0011] Chinese patent CN115212718A discloses an air purifier and deodorizer for use after renovation, comprising the following raw materials in parts by weight: 10-15 parts Maya Blue liquid, 5-10 parts nano-photocatalyst, 15-20 parts plant extract, 2-4 parts dispersant, 6-8 parts additives, and 80-100 parts deionized water; the nano-photocatalyst is titanium dioxide with a particle size between 4-8 nm; the plant extract is composed of the following raw materials: wild chrysanthemum extract, holly extract, cactus extract, artemisia extract, lavender extract, and deionized water; the dispersant is sodium polyacrylate; and the additives are glycerol. This invention combines Maya Blue liquid with plant extract, and after spraying indoors, it can rapidly absorb harmful gases and odors emitted from indoor air after renovation. After being applied to indoor furniture and walls, it can form an absorption film on the furniture and walls to oxidize and degrade harmful gases such as formaldehyde and benzene, as well as volatile organic compounds, on their surfaces.

[0012] The aforementioned patents all have the characteristics of complex formulas and high costs. Summary of the Invention

[0013] The purpose of this invention is to provide a hypoallergenic and highly efficient air purifier that simplifies the raw material formula of the air purifier while still maintaining a good deodorizing effect, reducing production costs, and causing no allergic or irritating reactions to the skin.

[0014] A hypoallergenic and highly efficient air purifier comprises the following raw materials in parts by weight: 20-30 parts D-limonene, 1-5 parts sesquiterpene organic matter, 1-5 parts tea polyphenols, 50-70 parts carbonate, and 5-10 parts emulsifier.

[0015] Furthermore, the hypoallergenic high-efficiency air purifier comprises the following raw materials in parts by weight: 27 parts D-limonene, 3 parts sesquiterpene organic matter, 4 parts tea polyphenols, 60 parts carbonate, and 6 parts emulsifier.

[0016] Furthermore, the carbonate is food grade.

[0017] Furthermore, the carbonate is one or a mixture of two of sodium carbonate and potassium carbonate.

[0018] Furthermore, the emulsifier is one or a mixture of D-mannitol, propylene glycol, sucrose ester, propylene glycol fatty acid ester, and glycerol fatty acid ester.

[0019] Furthermore, the D-limonene is obtained by extraction from orange or lemon peel.

[0020] Furthermore, the sesquiterpenoid organic compounds were obtained by extraction from Robinia pseudoacacia.

[0021] Furthermore, the preparation method of the hypoallergenic high-efficiency air purifier includes the following steps:

[0022] A. D-Limonene was prepared by extraction using orange or lemon peel as raw material;

[0023] B. Using *Robinia pseudoacacia* as raw material, extract and prepare sesquiterpenoid organic compounds;

[0024] C. Mix D-limonene, sesquiterpenoid organic compounds, tea polyphenols and emulsifier, stir evenly to obtain a liquid;

[0025] D. Mix the liquid with the carbonate and stir until homogeneous to obtain the final product.

[0026] This invention also discloses an application of a hypoallergenic, high-efficiency air purifier: the prepared hypoallergenic, high-efficiency air purifier is atomized and dispersed into the air.

[0027] Furthermore, the dosage of the hypoallergenic high-efficiency air purifier is 2-3 mL / m².

[0028] The advantages of this invention compared to the prior art are as follows:

[0029] 1. The effective components of the air purifier of this invention—D-limonene, sesquiterpenoids, and tea polyphenols—are derived from oranges or lemons, locust trees, and tea leaves, respectively. They are safe, non-toxic, and pollution-free, and will not cause allergies or harm upon contact with human skin, nor will inhalation have adverse effects on the lungs. Tea polyphenols can chemically react with odor molecules, weakening the bonds in the odor molecules and ultimately producing odorless and non-toxic substances. D-limonene and sesquiterpenoids can capture formaldehyde, synergistically enhancing the formaldehyde removal ability of tea polyphenols.

[0030] 2. Tea polyphenols contain catechins, which can react with formaldehyde. The phenolic hydroxyl groups dissociate, causing the formaldehyde carbonyl group to protonate, increasing the electron deficiency on the carbonyl carbon. Finally, the oxygen anion generated from the dissociation of catechins adds to formaldehyde, as shown in the following reaction:

[0031]

[0032] Tea polyphenols have a strong hydroxyl association ability, and the hydrogen bonds within the molecule are easily broken; D-limonene and sesquiterpenes contain multiple double bonds in their structure, which can form stable bonds with tea polyphenols; while sesquiterpenes are prone to forming aerosols in the air, D-limonene has extremely strong dissolving ability and can capture free formaldehyde, and the captured formaldehyde is then dissociated by tea polyphenols, thereby reducing the concentration of free formaldehyde in the air.

[0033] 3. This invention transforms an air purifier into a mist-like substance, forming micro-aerosol particles in the air. These particles capture, decompose, and transform organic compounds such as formaldehyde and benzene, improving indoor air quality and creating an oxygen-rich indoor gas environment. Furthermore, the atomized purifier can penetrate all areas of the room, including spaces and crevices invisible to the naked eye. The air purifier actively targets airborne viruses such as influenza and respiratory infections, achieving sterilization, disinfection, inhibition of disease transmission, and elimination of various odors. Testing shows that the atomized air purifier achieves a formaldehyde removal rate of over 94%. Detailed Implementation

[0034] Before further describing specific embodiments of the present invention, it should be understood that the scope of protection of the present invention is not limited to the specific embodiments described below; it should also be understood that the terminology used in the embodiments of the present invention is for describing specific embodiments and not for limiting the scope of protection of the present invention.

[0035] Example 1

[0036] A hypoallergenic and highly efficient air purifier comprises the following raw materials in parts by weight: 30 parts D-limonene, 1 part sesquiterpene ester, 1 part tea polyphenol, 63 parts potassium carbonate, 1 part D-mannitol, and 4 parts sucrose ester.

[0037] Preparation method:

[0038] A. D-Limonene was prepared by extraction using orange or lemon peel as raw material;

[0039] B. Sesquiterpene esters were prepared by extraction using *Robinia pseudoacacia* as raw material;

[0040] C. Mix D-limonene, sesquiterpene esters, tea polyphenols with D-mannitol and sucrose esters, stir well to obtain a liquid;

[0041] D. Mix the liquid with potassium carbonate and stir until homogeneous to obtain the final product.

[0042] Application method: Atomize and disperse the prepared hypoallergenic high-efficiency air purifier into the air; dosage is 2 mL / m².

[0043] Example 2

[0044] A hypoallergenic and highly efficient air purifier comprises the following raw materials in parts by weight: 25 parts D-limonene, 5 parts sesquiterpene esters, 5 parts tea polyphenols, 55 parts sodium carbonate, 5 parts propylene glycol, 3 parts propylene glycol fatty acid esters, and 2 parts glycerol fatty acid esters.

[0045] Preparation method:

[0046] A. D-Limonene was prepared by extraction using orange or lemon peel as raw material;

[0047] B. Sesquiterpene esters were prepared by extraction using *Robinia pseudoacacia* as raw material;

[0048] C. Mix D-limonene, sesquiterpene esters, tea polyphenols with propylene glycol, propylene glycol fatty acid esters, and glycerol fatty acid esters, stir well, and obtain a liquid.

[0049] D. Mix the liquid with sodium carbonate and stir until homogeneous to obtain the final product.

[0050] Application method: Atomize and disperse the prepared hypoallergenic high-efficiency air purifier into the air; the dosage is 2.2 mL / m².

[0051] Example 3

[0052] A hypoallergenic and highly efficient air purifier comprises the following raw materials in parts by weight: 27 parts D-limonene, 3 parts sesquiterpene esters, 4 parts tea polyphenols, 60 parts sodium carbonate, 3 parts propylene glycol, 2 parts sucrose esters, and 1 part propylene glycol fatty acid esters.

[0053] Preparation method:

[0054] A. D-Limonene was prepared by extraction using orange or lemon peel as raw material;

[0055] B. Sesquiterpene esters were prepared by extraction using *Robinia pseudoacacia* as raw material;

[0056] C. Mix D-limonene, sesquiterpene esters, tea polyphenols with propylene glycol, sucrose esters, and propylene glycol fatty acid esters, stir until homogeneous, and obtain a liquid.

[0057] D. Mix the liquid with sodium carbonate and stir until homogeneous to obtain the final product.

[0058] Application method: Atomize and disperse the prepared hypoallergenic high-efficiency air purifier into the air; the dosage is 2.5 mL / m².

[0059] Example 4

[0060] A hypoallergenic and highly efficient air purifier comprises the following raw materials in parts by weight: 20 parts D-limonene, 2 parts sesquiterpene esters, 1 part tea polyphenols, 70 parts potassium carbonate, 3 parts propylene glycol, and 4 parts glycerol fatty acid esters.

[0061] Preparation method:

[0062] A. D-Limonene was prepared by extraction using orange or lemon peel as raw material;

[0063] B. Sesquiterpene esters were prepared by extraction using *Robinia pseudoacacia* as raw material;

[0064] C. Mix D-limonene, sesquiterpene esters, tea polyphenols with propylene glycol and glycerol fatty acid esters, stir well to obtain a liquid;

[0065] D. Mix the liquid with potassium carbonate and stir until homogeneous to obtain the final product.

[0066] Application method: Atomize and disperse the prepared hypoallergenic high-efficiency air purifier into the air; the dosage is 2.8 mL / m².

[0067] Example 5

[0068] A hypoallergenic and highly efficient air purifier comprises the following raw materials in parts by weight: 30 parts D-limonene, 5 parts sesquiterpene esters, 5 parts tea polyphenols, 25 parts potassium carbonate, 25 parts sodium carbonate, 1 part D-mannitol, 2 parts propylene glycol fatty acid esters, and 7 parts glycerol fatty acid esters.

[0069] Preparation method:

[0070] A. D-Limonene was prepared by extraction using orange or lemon peel as raw material;

[0071] B. Sesquiterpene esters were prepared by extraction using *Robinia pseudoacacia* as raw material;

[0072] C. Mix D-limonene, sesquiterpene esters, tea polyphenols with D-mannitol, propylene glycol fatty acid esters, and glycerol fatty acid esters, stir evenly, and obtain a liquid.

[0073] D. Mix the liquid with potassium carbonate and sodium carbonate, and stir until homogeneous to obtain the final product.

[0074] Application method: Atomize and disperse the prepared hypoallergenic high-efficiency air purifier into the air; dosage is 3 mL / m².

[0075] Comparative Example 1

[0076] Ingredients: 4 parts tea polyphenols, 90 parts sodium carbonate, 3 parts propylene glycol, 2 parts sucrose ester, 1 part propylene glycol fatty acid ester.

[0077] Preparation method:

[0078] A. Mix tea polyphenols with propylene glycol, sucrose ester, and propylene glycol fatty acid ester, stir well, and obtain a liquid.

[0079] B. Mix the liquid with sodium carbonate and stir until homogeneous to obtain the final product.

[0080] Application method: Atomize the prepared air purifier and disperse it into the air; the dosage is 2.5 mL / m².

[0081] Comparative Example 2

[0082] Ingredients: 27 parts D-limonene, 4 parts tea polyphenols, 63 parts sodium carbonate, 3 parts propylene glycol, 2 parts sucrose ester, 1 part propylene glycol fatty acid ester.

[0083] Preparation method:

[0084] A. D-Limonene was prepared by extraction using orange or lemon peel as raw material;

[0085] B. Mix D-limonene, tea polyphenols with propylene glycol, sucrose ester, and propylene glycol fatty acid ester, stir well to obtain a liquid;

[0086] C. Mix the liquid with sodium carbonate and stir until homogeneous to obtain the final product.

[0087] Application method: Atomize the prepared air purifier and disperse it into the air; the dosage is 2.5 mL / m².

[0088] Comparative Example 3

[0089] Ingredients: 3 parts sesquiterpene esters, 4 parts tea polyphenols, 87 parts sodium carbonate, 3 parts propylene glycol, 2 parts sucrose esters, and 1 part propylene glycol fatty acid esters.

[0090] Preparation method:

[0091] A. Sesquiterpene esters were prepared by extraction from Robinia pseudoacacia.

[0092] B. Mix sesquiterpene esters, tea polyphenols with propylene glycol, sucrose esters, and propylene glycol fatty acid esters, stir until homogeneous, and obtain a liquid.

[0093] C. Mix the liquid with sodium carbonate and stir until homogeneous to obtain the final product.

[0094] Application method: Atomize the prepared air purifier and disperse it into the air; the dosage is 2.5 mL / m².

[0095] I. Formaldehyde Removal Test

[0096] 1. Testing Method

[0097] Refer to QB / T 2761-2006 Indoor Air Purification Product Purification Effect Test Method Disinfection Technical Specification (2002 Edition), with an action time of 24 hours.

[0098] 2. The test results are shown in Table 1.

[0099] Table 1. Formaldehyde removal efficiency of products from Examples 1-5 and Comparative Examples 1-3

[0100] Group <![CDATA[Concentration value in the test module, mg / m 3 > Formaldehyde removal rate / % control group 1.01 / Example 1 0.07 93.1 Example 2 0.08 92.1 Example 3 0.06 94.1 Example 4 0.08 92.1 Example 5 0.07 93.1 Comparative Example 1 0.20 80.2 Comparative Example 2 0.10 90.1 Comparative Example 3 0.18 82.2

[0101] As can be seen from the data in the table above, the formaldehyde removal rate of the products used in Examples 1 to 5 of this invention is all above 92.1%, which shows that they have a good formaldehyde removal effect.

[0102] Comparative Example 1 was based on Example 3 without adding sesquiterpenoid organic compounds and tea polyphenols, and still had a relatively high formaldehyde removal rate, but the effect was lower than that of Example 3; Comparative Example 2 added sesquiterpenoid organic compounds on the basis of Comparative Example 1, significantly improving the formaldehyde removal rate; Comparative Example 3 added tea polyphenols on the basis of Comparative Example 1, and the formaldehyde removal rate also increased to a certain extent. However, compared with Comparative Example 1, the formaldehyde removal rate when sesquiterpenoid organic compounds and tea polyphenols were used in combination in Example 3 of the present invention was higher than the sum of the effects of using sesquiterpenoid organic compounds and tea polyphenols alone in Comparative Examples 2 and 3. It can be seen that the combination of sesquiterpenoid esters and tea polyphenols can synergistically improve the effect of D-limonene in removing formaldehyde.

[0103] II. Skin irritation test

[0104] 1. Test method

[0105] Disinfection Technical Specifications (2002 Edition), Part II: Inspection Technical Specifications for Disinfection Products, 2.2.3.

[0106] Detection environment: Ordinary-class animal house, experimental animal use license number: SYXK (Guangdong) 2018-0086; room temperature 22-23°C, relative humidity 45-50%.

[0107] Experimental animals: Ordinary-class New Zealand white rabbits were used, provided by the Guangdong Provincial Center for Medical Experimental Animals (Sanshui Base) (experimental animal production license number: SCXK (Guangdong) 2019-0035). The body weight of the experimental animals was 2.2-2.4 kg, and the experimental animal certificate number was: NO.4441600007425.

[0108] Number / sex of experimental animals: 3 females.

[0109] Sample preparation: The stock solution of the sample in Example 3 was taken as the test substance.

[0110] Observation time points: Observe the skin reaction at the site where the test substance was administered at 1 h, 24 h, and 48 h after removing the test substance.

[0111] 2. Experimental procedures:

[0112] (1) Select 3 healthy adult New Zealand rabbits. 24 h before the test, shave the hair on both sides of the spine on the back of each experimental animal, prepare 2 depilated areas (each depilated area is about 3 cm × 3 cm), and conduct the test after confirming that the skin of the animal is intact.

[0113] (2) Apply 0.5 mL of the test substance evenly to a 2.5 cm × 2.5 cm area of ​​hairless skin on the left side of the experimental animal, then cover it with a patch and secure it with non-irritating adhesive tape and a bandage. Cover the hairless area on the other side as a control. Remove any remaining test substance with warm water 4 hours after application. Observe the skin reaction at the test site at 1 h, 24 h, and 48 h after removing the test substance and score the skin irritation reaction according to Table 2-11 "Skin Irritation Reaction Scoring Criteria". Record the skin reaction score at each observation point, calculate the reaction score according to the corresponding content in the evaluation provisions of Method 2.3.3.4, and assess the level of skin irritation intensity of the test substance to the animal according to Table 2-12 "Skin Irritation Intensity Grading".

[0114] Table 2-12 Disinfection Technical Specifications 2002 Skin Irritation Intensity Classification

[0115] Skin irritation index strength 0～＜0.5 Non-irritating 0.5～＜2.0 Mild irritation 2.0～＜6.0 moderately irritating 6.0～＜8.0 Strong irritant

[0116] 3. The test results are shown in Table 2:

[0117] Table 2 Results of acute skin irritation reactions of the test substances in rabbits

[0118]

[0119]

[0120] Test results showed that no irritation was observed on the intact skin of rabbits at any observation time point, and the highest score (irritation index) was 0, indicating that the deodorizing product of the present invention is safe and non-irritating.

[0121] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A hypoallergenic, highly efficient air purifier, characterized in that, The raw materials include the following parts by weight: 20-30 parts D-limonene, 1-5 parts sesquiterpene organic matter, 1-5 parts tea polyphenols, 50-70 parts carbonate, and 5-10 parts emulsifier; The D-limonene was obtained by extraction from orange or lemon peel; The sesquiterpenoid organic compounds were obtained by extraction from Robinia pseudoacacia.

2. The hypoallergenic, high-efficiency air purifier according to claim 1, characterized in that, The ingredients include the following parts by weight: 27 parts D-limonene, 3 parts sesquiterpenoid organic compounds, 4 parts tea polyphenols, 60 parts carbonates, and 6 parts emulsifiers.

3. The hypoallergenic, high-efficiency air purifier according to claim 1 or 2, characterized in that: Both the carbonates and emulsifiers mentioned are food grade.

4. The hypoallergenic, high-efficiency air purifier according to claim 3, characterized in that: The carbonate is one or a mixture of two of sodium carbonate and potassium carbonate.

5. The hypoallergenic, high-efficiency air purifier according to claim 3, characterized in that: The emulsifier is one or a mixture of D-mannitol, propylene glycol, sucrose ester, propylene glycol fatty acid ester, and glycerol fatty acid ester.

6. The hypoallergenic, high-efficiency air purifier according to claim 1 or 2, characterized in that, The preparation method includes the following steps: A. D-Limonene was prepared by extraction using orange or lemon peel as raw material; B. Using *Robinia pseudoacacia* as raw material, extract and prepare sesquiterpenoid organic compounds; C. Mix D-limonene, sesquiterpenoid organic compounds, tea polyphenols and emulsifier, stir evenly to obtain a liquid; D. Mix the liquid with the carbonate and stir until homogeneous to obtain the final product.

7. The application of a hypoallergenic, high-efficiency air purifier according to any one of claims 1 to 6, characterized in that: The prepared hypoallergenic and highly efficient air purifier is atomized and dispersed into the air.

8. The application of the hypoallergenic high-efficiency air purifier according to claim 7, characterized in that: The dosage is 2-3 mL / m².

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