Water-soluble menthol as well as application and preparation method thereof

Abstract

The invention provides water-soluble menthol, and relates to the technical field of fine chemical engineering new materials. The menthol injection comprises the following components: menthol serving as a main material, a main solvent, an auxiliary solvent, a cosolvent, a dispersing agent and a stabilizer. Menthol which is almost insoluble in water is prepared into 20% of daily chemical, edible and medical water-soluble menthol and 30% of high-content water-soluble menthol. Not only are several laboratory preparation methods for dissolving menthol in water innovated, but also water-soluble menthol series product real objects are obtained through process amplification research and pilot scale production, and feasible process routes, production operation steps and technical essentials are determined. The water-soluble menthol series product disclosed by the invention is high in content and has a good and stable water-soluble effect; the menthol can be directly added into various products in various fields of daily chemicals, foods and medicines, and the worry of many enterprises on the indissolvable menthol in water is relieved. The raw materials are safe and low in cost, the formula is reasonable and high in efficiency, the process is simplified and easy to operate, the input-output rate is 99.9% or above, and environmental protection and no pollution are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of fine chemical new materials, and in particular to a water-soluble menthol, an application and a preparation method thereof. Background Art

[0002] 1. Physical and chemical characteristics of menthol

[0003] Menthol is a colorless, transparent prismatic or needle-shaped crystal obtained by freezing, crystallizing, separating and purifying peppermint crude oil. It is solid at room temperature and has the aroma of peppermint crude oil and a spicy, refreshing taste.

[0004] The chemical name of menthol is: "5-methyl-2-isopropylcyclohexanol", referred to as menthol; the molecular formula is: "C 10 H 20 O”;

[0005] Molecular weight: "156.27";

[0006] The molecular structure is shown below;

[0007]

[0008] Menthol (menthol) molecules can be divided into three optical isomers: L-type, D-type and DL-type. Each optical isomer can be further divided into four different isomers. Therefore, there are 12 isomers of menthol in total.

[0009] The physical and chemical properties of menthol are shown in the following table:

[0010] Feature indicators Physical and chemical characteristics Characteristics Colorless, transparent needle-shaped or prismatic crystals or crystalline powder odor Has the characteristic aroma of Asian mint oil and a spicy, cooling taste Solubility It is completely soluble in ether, alcohol, acetic acid, chloroform, benzene, etc., and very slightly soluble in water. Melting point 42～44℃ Optical rotation -50°～-49°

[0011] As a common flavor and cooling agent, menthol is widely used in daily chemicals, food, medicine and other fields. However, it is a hydrophobic substance that is very slightly soluble in water, which limits its application in water-based or emulsion products.

[0012] 2. Background technology of menthol being soluble in water

[0013] In order to solve the problem of menthol dissolution in water-based or emulsion products, the following methods are usually used:

[0014] (1) When alcohol or other alcoholic solvents are used as a single or combined solvent to dissolve a small amount of menthol, a small amount of water can be added to form an emulsion, but as the amount of menthol or water increases, the emulsion becomes turbid. The menthol content of the obtained aqueous product is low and the water-soluble effect is poor.

[0015] (2) Menthol is modified by various organic chemical methods into menthol water-soluble potassium (sodium) salt, menthol propylene glycol polyether complex, menthol hydroxypropyl-β-cyclodextrin, etc., which have certain water-soluble functions. Some of them have poor water-soluble effects, some of them have low menthol content in water-based products, and some of them have high requirements for process equipment, and their actual use is still subject to certain restrictions;

[0016] (3) Tweens, Spans or other polyoxyethylene ether surfactants are used as solubilizers to prepare menthol hydrates. The menthol content of such aqueous solutions is relatively low, and the water-soluble effect is good, but the stability is poor.

[0017] (4) Menthol is mixed with polyoxyethylene ether surfactants, Tween surfactants, medium-chain fatty acid glycerides, etc., and water is added to form an emulsion, which is then nano-treated and preservatives are added to obtain a "menthol nanoemulsion". This water-based emulsion has a stable and good water-soluble effect, but the menthol content is not high, the formula is relatively complex, the requirements for process equipment are high, and the actual use is also subject to certain restrictions.

[0018] The above technologies are mainly based on the research and invention of the single technology of menthol dissolving in water, but lack the systematic and overall research and development for developing or creating a "menthol water-soluble system" or innovatively producing a "water-soluble menthol series product" that can be directly applied to multiple fields. This is exactly the main problem that the technology of the present invention is to solve. Summary of the invention

[0019] Based on this, it is necessary to provide several new methods for preparing menthol that are soluble in water, pay more attention to producing a series of water-soluble menthols with menthol contents up to more than 20% through process amplification research, which are water-soluble series products that can be used in daily chemical fields, food fields and medical fields respectively. It can not only overcome the disadvantages of low menthol contents that cannot be avoided in previous technologies, but also fully take into account the different requirements of various products in different fields for the water solubility of menthol, so that the special series water-soluble menthol products we provide are more in line with the requirements of "reasonable raw material cost, simple and safe formula, and simple and easy process equipment" in various fields on the basis of retaining good water solubility and stability. Therefore, it is more convenient for menthol to be directly applied in various water-based or emulsion products in various fields without worrying about its water solubility problem. At the same time, the present invention also provides two kinds of water-soluble menthols for daily chemical use with menthol contents up to 30% and preparation methods thereof.

[0020] To achieve the above object, the present invention provides the following technical solutions:

[0021] A water-soluble menthol comprises menthol as a main ingredient, a main solvent, an auxiliary solvent, a solubilizing agent, a dispersant and a stabilizer; the main solvent comprises a certain proportion of a certain type of polyoxyethylene ether or a certain type of polysorbate or a certain type of hydrogenated castor oil; the auxiliary solvent comprises ethylene glycol, propylene glycol and glyceryl monolaurate; the solubilizing agent comprises a certain type of hydrogenated castor oil or sorbitan monooleate or a certain type of polysorbate; the dispersant comprises propylene glycol and a certain type of polyethylene glycol; and the stabilizer comprises glyceryl monocaprylate and sucrose fatty acid ester.

[0022] The invention discloses an application of water-soluble menthol, which is used for preparing 20% ​​water-soluble menthol for daily chemical use, 20% water-soluble menthol for food use, 20% water-soluble menthol for medical use and 30% high-content water-soluble menthol for daily chemical use.

[0023] Preferably, when preparing 20% ​​water-soluble menthol for daily use, the main solvent is a certain type of polyoxyethylene ether, the auxiliary solvent is propylene glycol, the cosolvent is a certain type of polysorbate, the dispersant is a certain type of polyethylene glycol, and the stabilizer is monocaprylic glycerol. The mass percentages of each component are as follows:

[0024]

[0025] The method for preparing 20% ​​water-soluble menthol for daily use in a laboratory comprises the following steps:

[0026] S1: Weigh 41 g of a certain type of polyoxyethylene ether, 13 g of propylene glycol and 24 g of a certain type of polysorbate and add them into a 150 ml glass beaker in sequence. Place the beaker on a temperature-controllable magnetic stirring hot plate and heat it and keep it at a constant temperature of 55°C ± 2°C.

[0027] S2: Weigh 20 g of menthol and slowly add it into a glass beaker while stirring. Continue heating and keep the temperature constant at 60°C ± 2°C, and continue stirring until all the menthol crystals are melted.

[0028] S3: Weigh 1 gram of a certain type of polyethylene glycol and 1 gram of monocaprylin, add them into a glass beaker under stirring, and stop heating and stirring after magnetic stirring for 5 minutes to obtain 100 grams of 20% daily chemical water-soluble menthol.

[0029] Preferably, when preparing 20% ​​edible water-soluble menthol, the main solvent is a certain type of polysorbate, the auxiliary solvent is glyceryl monolaurate, the cosolvent is sorbitan monooleate, the dispersant is propylene glycol and a certain type of polyethylene glycol, and the stabilizer is glyceryl monocaprylate. The mass percentages of the components are as follows:

[0030]

[0031] The method for preparing 20% ​​edible water-soluble menthol in a laboratory comprises the following steps:

[0032] S1: Weigh 39 g of a certain type of polysorbate, 14 g of sorbitan monooleate and 8 g of glyceryl monolaurate and pour them into a 150 ml glass beaker in sequence, place the beaker on a temperature-controlled magnetic stirring hot plate and heat it and keep it at a constant temperature of 65°C ± 2°C;

[0033] S2: Weigh 20 grams of menthol and slowly add it into a glass beaker under stirring, maintain a constant temperature of 55°C ± 2°C, and continue stirring until all the menthol crystals are melted;

[0034] S3: Weigh 12 grams of propylene glycol, 6 grams of a certain type of polyethylene glycol and 1 gram of monocaprylin, add them into a glass beaker while stirring, and stir magnetically for 5 minutes before stopping the heat preservation and stirring to obtain 100 grams of 20% edible water-soluble menthol.

[0035] Preferably, when preparing 20% ​​medical water-soluble menthol, the main solvent is a certain type of hydrogenated castor oil, the auxiliary solvent is propylene glycol, the cosolvent is a certain type of polysorbate, the dispersant is a certain type of polyethylene glycol, and the stabilizer is sucrose fatty acid ester, and the mass percentage of each component is as follows:

[0036]

[0037] The method for preparing 20% ​​medical water-soluble menthol in the laboratory comprises the following steps:

[0038] S1: Weigh 60 g of a certain type of hydrogenated castor oil, 2 g of propylene glycol and 16 g of a certain type of polysorbate and add them into a 150 ml glass beaker in sequence. Place the beaker on a temperature-controlled magnetic stirring hot plate and heat it and keep it at a constant temperature of 60°C ± 2°C.

[0039] S2: Weigh 20 g of menthol and slowly add it into a glass beaker while stirring. Keep the temperature at 55°C ± 2°C and continue stirring until all the menthol crystals are melted.

[0040] S3: Weigh 1 gram of a certain type of polyethylene glycol and 1 gram of sucrose fatty acid ester, add them into a glass beaker while stirring, and stop heating and stirring after magnetic stirring for 5 minutes to obtain 100 grams of 20% medical water-soluble menthol.

[0041] Preferably, when preparing 30% high-content water-soluble menthol for daily use, there are formula one and formula two.

[0042] The main solvent of formula 1 is a certain type of polyoxyethylene ether, the auxiliary solvent is propylene glycol, the cosolvent is a certain type of hydrogenated castor oil, the dispersant is a certain type of polyethylene glycol, and the stabilizer is monocaprylic glyceride. The mass percentages of each component are as follows:

[0043]

[0044] Laboratory preparation method of formula 1:

[0045] S1: Weigh 49g of a certain type of polyoxyethylene ether, 16g of propylene glycol and 2g of a certain type of hydrogenated castor oil and add them into a 150ml glass beaker in sequence, place the beaker on a temperature-controllable magnetic stirring hot plate and heat it and keep the temperature at 55℃±2℃; continue stirring for 2 minutes to mix the liquid evenly;

[0046] S2: Adjust the temperature to 60℃±2℃, weigh 30g of menthol and slowly add it into the glass beaker while stirring, and continue stirring until all the menthol crystals are melted;

[0047] S3: Weigh 2 grams of a certain type of polyethylene glycol and 1 gram of monocaprylin, add them into a glass beaker under stirring, and stop heating and stirring after magnetic stirring for 5 minutes to obtain 100 grams of 30% high-content water-soluble menthol for daily use.

[0048] The main solvent of formula 2 is a certain type of polyoxyethylene ether, the auxiliary solvent is ethylene glycol, the cosolvent is a certain type of polysorbate, the dispersant is a certain type of polyethylene glycol, and the stabilizer is monocaprylic glycerol. The mass percentages of each component are as follows:

[0049]

[0050] The method for preparing the 30% high-content water-soluble menthol for daily use in formula 2 in the laboratory comprises the following steps:

[0051] S1: Weigh 43 g of a certain type of polyoxyethylene ether, 7 g of ethylene glycol and 16 g of a certain type of polysorbate and add them into a 150 ml glass beaker in sequence. Place the beaker on a temperature-controllable magnetic stirring hot plate and heat it and keep it at a constant temperature of 55°C ± 2°C.

[0052] S2: Weigh 30 g of menthol and slowly add it into a glass beaker while stirring. Keep the temperature at 60°C ± 2°C and continue stirring until all the menthol crystals are melted.

[0053] S3: Weigh 3 grams of a certain type of polyethylene glycol and 1 gram of monocaprylin, add them into a glass beaker under stirring, and stop heating and stirring after magnetic stirring for 5 minutes to obtain 100 grams of 30% high-content water-soluble menthol for daily use.

[0054] The beneficial effects of the present invention are:

[0055] (1) The effect of the present invention is not limited to innovating several methods for preparing menthol dissolved in water, but also innovating a series of menthol dissolved in water products - water-soluble menthol. This product can not only be used directly and conveniently in many products in the fields of daily chemicals, food and medicine, but also the menthol content therein is increased to 20%, or even up to 30%. It is a series of water-soluble menthol products that can be used directly, rather than a menthol water-based emulsion that needs to be prepared by the user;

[0056] (2) The water-soluble menthol series products prepared and produced by the present invention have the following advantages:

[0057] (A) The menthol content can be as high as 20-30%, and the product utilization rate is significantly improved;

[0058] (B) Without using alcohol at all, menthol can also obtain good and stable water-soluble effect;

[0059] (C) It can be directly added to various products in the fields of daily chemicals, food and medicine that require menthol flavoring or menthol cooling agent, thus eliminating the worries of many companies about the difficulty of menthol to dissolve in water;

[0060] (D) The raw materials are safe, the formula is reasonable, the process is simple and smooth, the equipment is simple and easy to operate, the input-output ratio is above 99.9%, and it is environmentally friendly and pollution-free;

[0061] (E) The raw material cost is low, which can significantly reduce production costs.

[0062] (3) The technology of the present invention not only innovates several laboratory preparation methods for dissolving menthol in water, but also obtains physical water-soluble menthol series products through pilot production, verifying the creativity, advancement and practicality of the laboratory preparation method; and determines the feasible process route, production operation steps and technical essentials; and also clarifies the physical and chemical indicators and water solubility test methods of the water-soluble menthol series products produced by the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 A summary process map of the water-soluble menthol series products of the present invention;

[0064] Figure 2 It is the process route of 20% water-soluble menthol for daily use;

[0065] Figure 3 The process map for 20% edible water-soluble menthol;

[0066] Figure 4 The process map for 20% medical water-soluble menthol;

[0067] Figure 5The process route diagram of 30% daily chemical water-soluble menthol formula 1;

[0068] Figure 6 It is the process route of the 30% daily chemical water-soluble menthol formula 2; DETAILED DESCRIPTION

[0069] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0070] The water-soluble menthol series products prepared by the present invention or produced by pilot scale-up process adopt ultramicroemulsification direct dissolution technology, and the water-soluble mechanism thereof is as follows:

[0071] After the high-efficiency direct solvent specially formulated for natural menthol is mixed and synthesized with natural menthol in a certain proportion and a special process, it can form completely oil-in-water (W / O) ultra-micro micelles and micellar droplets in a certain concentration of aqueous solution. The solution composed of droplets with a diameter as small as 50nm will no longer hinder the penetration of light and is transparent, so it is called a micro-emulsified homogeneous transparent water-soluble system. This water-soluble system can organically associate the active substance menthol to be micro-emulsified in the micro-emulsion droplets, presenting a "molecular pair" or "molecular cluster" state of "continuous dispersion and exposure", and dissolve into a homogeneous transparent quasi-solution through "phase transfer". Then, according to the different characteristics and technical requirements of products in different fields, adding appropriate amounts of different types of dispersants and stabilizers can greatly improve its dispersibility, dissolution, release and bioavailability compared with ordinary emulsified solubilization products, and it is also in a metastable state in thermodynamics. Finally, it is dynamically associated and homogenized after high shear stirring. Thus, the menthol, which is almost insoluble in water, is modified into a series of water-soluble menthol products that can form stable hydrates (lamellar transparent crystalline liquids) with water through dynamic associations such as coordination, compounding, and hydration. This product is almost anhydrous and not an aqueous solution, but it can be directly dissolved in water at a high proportion.

[0072] Functional system and formula of raw material components:

[0073] The invention creates a raw material component functional system of water-soluble menthol, which divides different raw material components in water-soluble menthol series products into main material, main solvent, auxiliary solvent, co-solvent, dispersant and stabilizer according to their different functions.

[0074] The system uses menthol as the main ingredient; the main solvent includes a considerable proportion of a certain type of polyoxyethylene ether or a certain type of polysorbate or a certain type of hydrogenated castor oil; the auxiliary solvent includes ethylene glycol, propylene glycol and glyceryl monolaurate; the co-solvent includes a certain type of hydrogenated castor oil or sorbitan monooleate or a certain type of polysorbate; the dispersant includes propylene glycol and a certain type of polyethylene glycol; and the stabilizer includes glyceryl monocaprylate and sucrose fatty acid ester.

[0075] This system flexibly brings into play the different functions of each component through different formula proportions, and conducts process scale-up pilot tests based on the different characteristics of each component in the formula to determine the reasonable process route and technical essentials of production operation, so as to achieve or meet the functional goals and technical requirements of different specifications of water-soluble menthol series products.

[0076] Product formula:

[0077] The mass ratio (W / W) of each component of the 20% water-soluble menthol for daily use of the present invention is:

[0078]

[0079]

[0080] The mass ratio of each component of the 20% edible water-soluble menthol of the present invention (W / W):

[0081] The mass ratio (W / W) of each component of the 20% medical water-soluble menthol of the present invention is:

[0082] The mass ratio (W / W) of each component of the 30% high-content water-soluble menthol of the present invention is as follows: ① Formula 1:

[0083]

[0084] ②Formula 2:

[0085]

[0086] (Note: In production practice, the actual proportion of the main ingredient menthol should be slightly greater than 20% or 30%)

[0087] The present invention comprises the following process conditions and operating techniques:

[0088] (A) Feeding order: The technical requirements of the present invention are that the feeding order of each component material during preparation or production is:

[0089] ① Main solvent: a certain type of polyoxyethylene ether or a certain type of polysorbate or a certain type of hydrogenated castor oil;

[0090] ② Auxiliary solvents: ethylene glycol, propylene glycol and glyceryl monolaurate;

[0091] ③ Cosolvent: a certain type of polysorbate or sorbitan monooleate or a certain type of hydrogenated castor oil;

[0092] ④Main ingredient: menthol;

[0093] ⑤Dispersant: propylene glycol or a certain type of polyethylene glycol;

[0094] ⑥ Stabilizer: monocaprylic glyceride or sucrose fatty acid ester;

[0095] If a certain specification of water-soluble menthol formula does not contain one or several of the above components, then do not add them, and the remaining components are added in order;

[0096] (B) Temperature control: The technical requirements of the present invention are to determine the temperature control range of each link of the preparation or pilot production according to the physical and chemical properties of the different components such as melting point, cloud point, freezing point, etc., within the range of 55°C to 65°C ± 2°C. The temperature control of different formula products in different production links is different;

[0097] (C) Stirring method and speed:

[0098] ① The technical requirements of the present invention are to use magnetic stirring in the laboratory to prepare small samples, and to use high shear variable frequency speed stirring in the workshop pilot production;

[0099] ② The technical requirements of the present invention are to use different stirring rates in different stages of pilot production. When the menthol crystals are not completely melted, the stirring speed is controlled at 300 to 350 rpm; in the later stage of material synthesis, the stirring speed is controlled at more than 1200 rpm;

[0100] Equipment selection:

[0101] ① The technology of the present invention uses Shanghai Lei Magnetic Temperature Control Timing JB-3 Heating Constant Temperature Magnetic Stirrer to prepare small samples in the laboratory.

[0102] ② The technical requirements of the present invention are that the equipment for the pilot production process unit enlargement is a 50-liter interlayer electric heating temperature-controlled stainless steel reactor, and is equipped with a variable frequency speed-adjustable high-shear mixer. Each time, 50 kilograms of a certain specification of water-soluble menthol finished product can be produced in a trial manner.

[0103] Application and preparation method of the present invention

[0104] The specific implementation method of the preparation of the present invention includes: first, laboratory preparation method and steps; second, process route and production technology and operation essentials and steps determined by pilot test. Since the water-soluble menthol series products produced by the present invention are divided into three different specifications: daily chemical use, food use and medical use, the laboratory preparation steps and workshop production steps are described one by one as follows:

[0105] The specific method and implementation steps of the laboratory preparation and pilot process scale-up production of 20% water-soluble menthol for daily use in the present invention are as follows:

[0106] (1) Laboratory preparation method

[0107] (A) Weigh 41 g of a certain type of polyoxyethylene ether, 13 g of propylene glycol and 24 g of a certain type of polysorbate and pour them into a 150 ml glass beaker in sequence. Place the beaker on a temperature-controlled magnetic stirring hot plate and heat it while maintaining a constant temperature of 55°C ± 2°C.

[0108] (B) Accurately weigh 20 g of menthol and slowly add it into a glass beaker while stirring. Continue heating and keep the temperature constant at 60°C ± 2°C, and continue stirring until all the menthol crystals are melted.

[0109] (C) Weigh 1 gram of a certain type of polyethylene glycol and 1 gram of monocaprylin, add them into a glass beaker under stirring, and stir magnetically for 5 minutes before stopping the heating and stirring to obtain 100 grams of 20% daily chemical water-soluble menthol.

[0110] (2) The process route and operation steps for pilot-scale production of 20% daily chemical grade water-soluble menthol are as follows:

[0111] (A) Turn on a 50-liter interlayer electric heating stainless steel reactor and heat it to 55°C ± 2°C and keep the temperature constant. At the same time, add 20.5 kg of a certain type of polyoxyethylene ether, 6.5 kg of propylene glycol and 12 kg of a certain type of polysorbate into the reactor in sequence. Turn on a high-shear variable-frequency speed-adjustable mixer and control the speed to 300-350 rpm. Keep the temperature and keep stirring at the original speed for 3 minutes.

[0112] (B) Adjust the temperature of the reactor to 60°C ± 2°C, slowly add 10.3 kg of menthol under stirring, and pay attention to controlling the feeding speed of menthol to prevent too much menthol crystals from depositing at the bottom of the reactor. Keep the temperature and continue stirring at the original speed for about 5 minutes, turn on the lighting of the reactor, and pay attention to observe that the menthol crystals in the reactor are completely melted and the liquid becomes transparent;

[0113] (C) 0.5 kg of a certain type of polyethylene glycol and 0.5 kg of monocaprylin were weighed and added to the reactor, the variable frequency speed regulation shearing function was turned on, and the speed of the high shear mixer was adjusted to be above 1200 rpm. After reacting for 10 minutes, the heat preservation was stopped and the machine was turned off to obtain 50.3 kg of a daily chemical water-soluble menthol product with a content of 20%.

[0114] (3) Note: Considering that the content of menthol in the actual product produced in the workshop should be greater than 20%, the actual proportion of menthol as the main ingredient should be slightly greater than 20%.

[0115] The specific method and implementation steps of the technology of the present invention using laboratory preparation and pilot scale production of 20% edible water-soluble menthol are as follows:

[0116] (1) Laboratory preparation method

[0117] (A) Weigh 39 g of a certain type of polysorbate, 14 g of sorbitan monooleate and 8 g of glyceryl monolaurate and pour them into a 150 ml glass beaker in sequence, place the beaker on a 65°C ± 2°C magnetic stirring hot plate and heat and stir for 3 minutes until the liquid is evenly mixed;

[0118] (B) adjusting the temperature to 55°C ± 2°C, weighing 20 g of menthol and slowly adding it into a glass beaker under stirring, maintaining the temperature at 55°C ± 2°C, and continuing to stir until all the menthol crystals are melted;

[0119] (C) Then weigh 12 grams of propylene glycol, 6 grams of a certain type of polyethylene glycol and 1 gram of monocaprylin, add them into a glass beaker while stirring, and stir magnetically for 5 minutes to obtain 100 grams of edible water-soluble menthol.

[0120] (2) The technical points and operation steps for pilot-scale production of 20% edible water-soluble menthol are as follows:

[0121] (A) Turn on a 50-liter double-layer electrically heated stainless steel reactor and heat it to 65°C ± 2°C and keep the temperature constant. At the same time, add 19.5 kg of a certain type of polysorbate, 7 kg of sorbitan monooleate and 4 kg of glyceryl monolaurate into the reactor in sequence. Turn on a high-shear variable-frequency speed-adjustable mixer and control the speed to 300-350 rpm. Keep the temperature and keep stirring at the original speed for 3 minutes.

[0122] (B) Adjust the temperature of the reactor to 55°C ± 2°C, slowly add 10.3 kg of menthol under stirring, and pay attention to controlling the feeding speed of menthol to prevent too much menthol crystals from depositing at the bottom of the reactor. Keep the temperature and continue stirring at the original speed for about 5 minutes, turn on the lighting of the reactor, and pay attention to observe that the menthol crystals in the reactor are completely melted and the liquid becomes transparent;

[0123] (C) 6 kg of propylene glycol, 3 kg of a certain type of polyethylene glycol and 0.5 kg of monocaprylin are weighed and added into the reactor, the variable frequency speed regulation shear function is turned on, the speed of the high shear mixer is adjusted to above 1200 rpm, and after reacting for 10 minutes, the heat preservation is stopped and the machine is turned off to obtain 50.3 kg of edible water-soluble menthol product with a content of 20%.

[0124] (3) Note: Considering that the content of menthol in the actual product produced in the workshop should be greater than 20%, the actual proportion of menthol as the main ingredient should be slightly greater than 20%.

[0125] The specific method and implementation steps of the laboratory preparation and pilot process scale-up production of 20% medical water-soluble menthol are as follows:

[0126] (1) Laboratory preparation method

[0127] (A) Weigh 60 g of a certain type of hydrogenated castor oil, 2 g of propylene glycol and 16 g of a certain type of polysorbate and pour them into a 150 ml glass beaker in sequence, place the beaker on a 60°C ± 2°C magnetic stirring hot plate and heat and stir for 3 minutes until the liquid is evenly mixed;

[0128] (B) adjusting the temperature to 55°C ± 2°C, weighing 20 g of menthol and slowly adding it into a glass beaker under stirring, maintaining the temperature at 55°C ± 2°C, and continuing to stir until all the menthol crystals are melted;

[0129] (C) Weigh 1 gram of a certain type of polyethylene glycol and 1 gram of sucrose fatty acid ester, add them into a glass beaker while stirring, and stir magnetically for 5 minutes to obtain 100 grams of medical water-soluble menthol.

[0130] (2) The technical points and operation steps for pilot-scale production of 20% medical water-soluble menthol are as follows:

[0131] (A) Start a 50-liter double-layer electric heating stainless steel reactor and heat it to 60°C ± 2°C and keep the temperature constant. At the same time, add 30 kg of a certain type of hydrogenated castor oil, 1 kg of propylene glycol and 8 kg of a certain type of polysorbate into the reactor in sequence. Start a high-shear variable-frequency speed-adjustable mixer and control the speed to 300-350 rpm. Keep the temperature and keep stirring at the original speed for 3 minutes.

[0132] (B) Adjust the temperature of the reactor to 55°C ± 2°C, slowly add 10.3 kg of menthol under stirring, and pay attention to controlling the feeding speed of menthol to prevent too much menthol crystals from depositing at the bottom of the reactor. Keep the temperature and continue stirring at the original speed for about 5 minutes, turn on the lighting of the reactor, and pay attention to observe that the menthol crystals in the reactor are completely melted and the liquid becomes transparent;

[0133] (C) 0.5 kg of a certain type of polyethylene glycol and 0.5 kg of sucrose fatty acid ester are weighed and added to the reactor, the variable frequency speed regulation shear function is turned on, and the speed of the high shear mixer is adjusted to above 1200 rpm. After reacting for 10 minutes, the heat preservation is stopped and the machine is turned off, and 50.3 kg of a medical water-soluble menthol product with a content of 20% is obtained.

[0134] (3) Note: Considering that the content of menthol in the actual product produced in the workshop should be greater than 20%, the actual proportion of menthol as the main ingredient should be slightly greater than 20%.

[0135] The specific method and implementation steps of the laboratory preparation and amplification production of 30% high-content water-soluble menthol for daily use in the present invention are as follows:

[0136] (1) Laboratory preparation of formula 1

[0137] (A) Weigh 49 g of a certain type of polyoxyethylene ether, 16 g of propylene glycol and 2 g of a certain type of hydrogenated castor oil and add them into a 150 ml glass beaker in sequence, place the beaker on a temperature-controllable magnetic stirring hot plate and heat it while maintaining the temperature at 55°C ± 2°C; continue stirring for 2 minutes to mix the feed liquid evenly;

[0138] (B) adjusting the temperature to 60°C ± 2°C, weighing 30 g of menthol and slowly adding it into a glass beaker while stirring, and continuing to stir until all the menthol crystals are melted;

[0139] (C) 2 g of a certain type of polyethylene glycol and 1 g of monocaprylin are weighed and added into a glass beaker under stirring. After 5 minutes of magnetic stirring, the heating and stirring are stopped to obtain 100 g of 30% high-content water-soluble menthol for daily use.

[0140] (2) Laboratory preparation of formula 2

[0141] (A) Weigh 43 g of a certain type of polyoxyethylene ether, 7 g of ethylene glycol and 16 g of a certain type of polysorbate and add them into a 150 ml glass beaker in sequence. Place the beaker on a temperature-controllable magnetic stirring hot plate and heat it while maintaining a constant temperature of 55°C ± 2°C.

[0142] (B) Weigh 30 g of menthol and slowly add it into a glass beaker while stirring. Keep the temperature at 60°C ± 2°C and continue stirring until all the menthol crystals are melted.

[0143] (C) 3 g of a certain type of polyethylene glycol and 1 g of monocaprylin are weighed and added into a glass beaker under stirring. After 5 minutes of magnetic stirring, the heating and stirring are stopped to obtain 100 g of 30% high-content water-soluble menthol for daily use.

[0144] (3) The technical points and operation steps of the technical process of the present invention for scaling up the production of 30% high-content water-soluble menthol for daily use are as follows:

[0145] Technical points and operation steps of formula 1:

[0146] (A) Turn on a 50-liter interlayer electric heating stainless steel reactor and heat it to 55°C ± 2°C and keep the temperature constant. At the same time, add 24.5 kg of a certain type of polyoxyethylene ether, 8 kg of propylene glycol and 1 kg of a certain type of polysorbate into the reactor in sequence. Turn on a high-shear variable-frequency speed-regulating mixer and control the speed to 300-350 rpm. Keep the temperature and keep stirring at the original speed for 3 minutes.

[0147] (B) Adjust the temperature of the reactor to 60°C ± 2°C, slowly add 15.3 kg of menthol under stirring, and pay attention to controlling the feeding speed of menthol to prevent too much menthol crystals from depositing at the bottom of the reactor. Keep the temperature and continue stirring at the original speed for about 5 minutes, turn on the lighting of the reactor, and pay attention to observe that the menthol crystals in the reactor are completely melted and the liquid becomes transparent;

[0148] (C) 1 kg of a certain type of polyethylene glycol and 0.5 kg of monocaprylin were weighed and added to the reactor, the variable frequency speed regulation shearing function was turned on, and the speed of the high shear mixer was adjusted to be above 1200 rpm. After reacting for 10 minutes, the heat preservation was stopped and the machine was turned off to obtain 50.3 kg of a 30% high-content water-soluble menthol product for daily use.

[0149] Technical points and operation steps of formula 2:

[0150] (A) Turn on a 50-liter interlayer electric heating stainless steel reactor and heat it to 55°C ± 2°C and keep the temperature constant. At the same time, add 21.5 kg of a certain type of polyoxyethylene ether, 3.5 kg of ethylene glycol and 8 kg of a certain type of polysorbate into the reactor in sequence. Turn on a high-shear variable-frequency speed-adjustable mixer and control the speed to 300-350 rpm. Keep the temperature and keep stirring at the original speed for 3 minutes.

[0151] (B) Adjust the temperature of the reactor to 60°C ± 2°C, slowly add 15.3 kg of menthol under stirring, and pay attention to controlling the feeding speed of menthol to prevent too much menthol crystals from depositing at the bottom of the reactor. Keep the temperature and continue stirring at the original speed for about 5 minutes, turn on the lighting of the reactor, and pay attention to observe that the menthol crystals in the reactor are completely melted and the liquid becomes transparent;

[0152] (C) 1.5 kg of a certain type of polyethylene glycol and 0.5 kg of monocaprylin were weighed and added to the reactor, the variable frequency speed regulation shearing function was turned on, and the speed of the high shear mixer was adjusted to be above 1200 rpm. After reacting for 10 minutes, the heat preservation was stopped and the machine was turned off to obtain 50.3 kg of a 30% high-content water-soluble menthol product for daily use.

[0153] (4) Note: Considering that the content of menthol in the actual product produced in the workshop should be greater than 30%, the actual proportion of menthol as the main ingredient should be slightly greater than 30%.

[0154] Product indicators and testing

[0155] 1. The physical and chemical properties and technical indicators of various specifications of water-soluble menthol series products prepared by the technology of the present invention or scaled up by pilot process are shown in the following table:

[0156]

[0157]

[0158] Note: Due to the different water-soluble systems, there is a big gap between the coagulation range of water-soluble menthol used in daily chemicals and that of water-soluble menthol used in food and medicine.

[0159] 2. Water solubility test

[0160] The water solubility effect test of the high-content water-soluble menthol for daily use prepared by the present invention or produced by pilot process can be carried out according to the following steps:

[0161] (1) Water solubility test 1: Under ambient temperature (25°C), accurately and evenly weigh 1 gram of sample and place it in a 100 ml glass measuring cylinder, add 30 ml of distilled water and shake until the sample is completely mixed into the water; continue to add distilled water to the 100 ml mark and shake well. The resulting solution should not be turbid but should be homogeneous and transparent. If it remains homogeneous and transparent after standing for one week under ambient temperature (25°C), it is qualified.

[0162] (2) Water solubility test 2: At ambient temperature (25°C), accurately and evenly weigh 1 gram of sample and place it in a 1000 ml glass measuring cylinder, add 50 ml of distilled water and shake until the sample is completely mixed into the water; continue to add distilled water to the 1000 ml mark and shake well. The resulting solution should not be turbid but should be homogeneous and transparent. If it remains homogeneous and transparent after standing for one week at ambient temperature (25°C), it is qualified.

[0163] (3) Water-soluble stability test: The water-soluble menthol series products of various specifications produced by the present invention are sealed and protected from light, and stored at room temperature for 15 months. Then the product is placed in a 35°C water bath and stirred until it is clear and transparent, then a sample is taken and the water-soluble test steps 1 and 2 are followed. If the product is still homogeneous and transparent, it is qualified.

[0164] (4) Before sampling and testing, the edible and medicinal water-soluble menthol produced by the present invention should be placed in a 35°C water bath and shaken until transparent, and then a representative sample can be weighed for water-solubility testing.

[0165] (5) If the 20% and 30% water-soluble menthol for daily use produced by the present invention has been subjected to an ambient temperature below -1°C during storage or has partially solidified or even completely solidified into a paste, it should be placed in a 35°C water bath and shaken until transparent before sampling, and then a representative sample can be weighed for water solubility testing.

[0166] 3. Description of water-soluble effect

[0167] (1) The water-soluble menthol of various specifications prepared or pilot-produced by the technology of the present invention has good compatibility with aqueous solutions of most substances, but addition tests are required when encountering strong acids and alkalis;

[0168] (2) Each specification of water-soluble menthol prepared or produced by the technology of the present invention is qualified when the aqueous solution is homogeneous and transparent at a concentration of 1% to 1‰. In fact, some specifications of water-soluble menthol can even show a homogeneous and transparent water-soluble effect in an aqueous solution with a concentration of 3 to 5%. It is enough to meet the water-soluble requirements of menthol for most products in the three major application fields.

[0169] (3) Ambient temperature is an important condition for water solubility testing. If the water solubility test needs to be conducted at a lower ambient temperature, distilled water at 25-35°C should be used for dilution. If the static environment is lower than 25°C, the homogeneous transparent solution may appear turbid or turbid. At this time, the turbid aqueous solution can be heated to an ambient temperature above 25°C, and the aqueous solution will still appear homogeneous and transparent after shaking.

[0170] 4. Other instructions

[0171] (1) All raw materials used in the water-soluble menthol for daily chemical, edible and medicinal use of the present invention should comply with the relevant national standards for corresponding cosmetic raw materials, food additive raw materials and pharmaceutical raw materials.

[0172] (2) The embodiments described in the present invention only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present invention. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the attached claims.

Claims

1. A water-soluble menthol, characterized in that: The invention comprises the main ingredient of menthol, a main solvent, an auxiliary solvent, a solubilizing agent, a dispersant and a stabilizer; the main solvent comprises a considerable proportion of a certain type of polyoxyethylene ether or a certain type of polysorbate or a certain type of hydrogenated castor oil; the auxiliary solvent comprises ethylene glycol, propylene glycol and glyceryl monolaurate; the solubilizing agent comprises a certain type of polysorbate, sorbitan monooleate or a certain type of hydrogenated castor oil; the dispersant comprises propylene glycol and a certain type of polyethylene glycol; the stabilizer comprises glyceryl monocaprylate and sucrose fatty acid ester.

2. The use of a water-soluble menthol according to claim 1, characterized in that: It is used for preparing 20% ​​water-soluble menthol for daily chemical use, 20% water-soluble menthol for food use, 20% water-soluble menthol for medical use and 30% high-content water-soluble menthol for daily chemical use.

3. The use of water-soluble menthol according to claim 2, characterized in that: When preparing 20% ​​water-soluble menthol for daily use, the main solvent is a certain type of polyoxyethylene ether, the auxiliary solvent is propylene glycol, the cosolvent is a certain type of polysorbate, the dispersant is a certain type of polyethylene glycol, and the stabilizer is monocaprylic glycerol. The mass percentages of the components are as follows: Method for preparing 20% ​​water-soluble menthol for daily use in the laboratory, The following steps are involved: S1: Weigh 41 g of a certain type of polyoxyethylene ether, 13 g of propylene glycol and 24 g of a certain type of polysorbate and pour them into a 150 ml glass beaker in sequence. Place the beaker on a temperature-controllable magnetic stirring hot plate and heat it and keep it at a constant temperature of 55°C ± 2°C. S2: Weigh 20 g of menthol and slowly add it into a glass beaker while stirring. Continue heating and keep the temperature constant at 60°C ± 2°C, then continue stirring until all the menthol crystals are melted. S3: Weigh 1 gram of a certain type of polyethylene glycol and 1 gram of monocaprylin, add them into a glass beaker under stirring, and stop heating and stirring after magnetic stirring for 5 minutes to obtain 100 grams of 20% daily chemical water-soluble menthol.

4. The use of water-soluble menthol according to claim 2, characterized in that: When preparing 20% ​​edible water-soluble menthol, the main solvent is a certain type of polysorbate, the auxiliary solvent is glyceryl monolaurate, the cosolvent is sorbitan monooleate, the dispersant is propylene glycol and a certain type of polyethylene glycol, and the stabilizer is glyceryl monocaprylate. The mass percentages of the components are as follows: Method for preparing 20% ​​edible water-soluble menthol in the laboratory, The following steps are involved: S1: Weigh 39 g of a certain type of polysorbate, 14 g of sorbitan monooleate and 8 g of glyceryl monolaurate and pour them into a 150 ml glass beaker in sequence, place the beaker on a temperature-controlled magnetic stirring hot plate and heat it and keep it at a constant temperature of 65°C ± 2°C; S2: Weigh 20 grams of menthol and slowly add it into a glass beaker under stirring, maintain a constant temperature of 55°C ± 2°C, and continue stirring until all the menthol crystals are melted; S3: Weigh 12 grams of propylene glycol, 6 grams of a certain type of polyethylene glycol and 1 gram of monocaprylin, add them into a glass beaker while stirring, and stir magnetically for 5 minutes before stopping the heat preservation and stirring to obtain 100 grams of 20% edible water-soluble menthol.

5. The use of water-soluble menthol according to claim 2, characterized in that: When preparing 20% ​​medical water-soluble menthol, the main solvent is a certain type of hydrogenated castor oil, the auxiliary solvent is propylene glycol, the cosolvent is a certain type of polysorbate, the dispersant is a certain type of polyethylene glycol, and the stabilizer is a certain type of sucrose fatty acid ester. The mass percentages of the components are as follows: The method for preparing 20% ​​medical water-soluble menthol in the laboratory comprises the following steps: S1: Weigh 60 g of a certain type of hydrogenated castor oil, 2 g of propylene glycol and 16 g of a certain type of polysorbate and add them into a 150 ml glass beaker in sequence. Place the beaker on a temperature-controlled magnetic stirring hot plate and heat it and keep it at a constant temperature of 60°C ± 2°C. S2: Weigh 20 g of menthol and slowly add it into a glass beaker while stirring. Keep the temperature at 55°C ± 2°C and continue stirring until all the menthol crystals are melted. S3: Weigh 1 gram of a certain type of polyethylene glycol and 1 gram of sucrose fatty acid ester, add them into a glass beaker while stirring, and stop heating and stirring after magnetic stirring for 5 minutes to obtain 100 grams of 20% medical water-soluble menthol.

6. The use of water-soluble menthol according to claim 2, characterized in that: When preparing 30% high-content water-soluble menthol for daily use, there are formula one and formula two.

7. The use of water-soluble menthol according to claim 6, characterized in that: The main solvent of formula 1 is a certain type of polyoxyethylene ether, the auxiliary solvent is propylene glycol, the cosolvent is a certain type of hydrogenated castor oil, the dispersant is a certain type of polyethylene glycol, and the stabilizer is monocaprylic glyceride. The mass percentages of each component are as follows: The method for preparing the 30% high-content water-soluble menthol for daily use in formula 1 in the laboratory comprises the following steps: S1: Weigh 49 g of a certain type of polyoxyethylene ether, 16 g of propylene glycol and 2 g of a certain type of hydrogenated castor oil and pour them into a 150 ml glass beaker in sequence, place the beaker on a temperature-controllable magnetic stirring hot plate and heat it and keep it at a constant temperature of 55°C ± 2°C; S2: Accurately weigh 30 grams of menthol and slowly add it into a glass beaker while stirring. Keep the temperature at 60℃±2℃ and continue stirring until all the menthol crystals are melted. S3: Weigh 2 grams of a certain type of polyethylene glycol and 1 gram of monocaprylin, add them into a glass beaker under stirring, and stop heating and stirring after magnetic stirring for 5 minutes to obtain 100 grams of 30% high-content water-soluble menthol for daily use.

8. The use of water-soluble menthol according to claim 6, characterized in that: The main solvent of formula 2 is a certain type of polyoxyethylene ether, the auxiliary solvent is ethylene glycol, the cosolvent is a certain type of polysorbate, the dispersant is a certain type of polyethylene glycol, and the stabilizer is monocaprylic glycerol. The mass percentages of each component are as follows: The method for preparing the 30% high-content water-soluble menthol for daily use in formula 2 in the laboratory comprises the following steps: S1: Weigh 43 g of a certain type of polyoxyethylene ether, 7 g of ethylene glycol and 16 g of a certain type of polysorbate and add them into a 150 ml glass beaker in sequence. Place the beaker on a temperature-controllable magnetic stirring hot plate and heat it and keep it at a constant temperature of 55°C ± 2°C. S2: Weigh 30 g of menthol and slowly add it into a glass beaker while stirring. Keep the temperature at 55°C ± 2°C and continue stirring until all the menthol crystals are melted. S3: Weigh 3 grams of a certain type of polyethylene glycol and 1 gram of monocaprylin, add them into a glass beaker under stirring, and stop heating and stirring after magnetic stirring for 5 minutes to obtain 100 grams of 30% high-content water-soluble menthol for daily use.

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