Synthesis method of 1, 2-diol and application of 1, 2-diol in cosmetics

Abstract

The invention discloses a synthetic method of bio-based 1, 2-diol and application of the bio-based 1, 2-diol in cosmetics. The invention discloses a preparation method of 1, 2-diol, which comprises the step of reducing bio-based 2-hydroxy fatty acid or ester thereof to obtain the 1, 2-diol. The 1, 2-hexanediol, 1, 2-octylene glycol, 1, 2-decanediol and other products obtained by the invention are applied to cosmetics, and have the characteristics of high purity, few impurities, good smell, low irritation and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic compound synthesis, and in particular, relates to a method for synthesizing 1,2-diol and an application thereof in cosmetics. Background Art

[0002] 1,2-Alkanediol In the development of the chemical industry, vicinal diols are indispensable, especially 1,2-vicinal diol, which is a special product with chemical process features that other chemicals do not have.

[0003] 1,2-diol products have a wide range of uses. For example, 1,2-hexanediol is an important chemical raw material, which is mostly used in the ink of color inkjet printers, high-end cosmetics and synthetic raw materials in the pharmaceutical industry. In the application of ink, printers are a widely used tool in contemporary society. 1,2-hexanediol can be used as a raw material for inkjet printing ink in printers, and its use is becoming more and more widespread. Canon, Seiko Epson and others add 1,2-hexanediol to ink to obtain more uniform ink with excellent ozone resistance and gloss. In the application of cosmetics, 1,2-hexanediol is added to daily necessities and used as a preservative that the human body contacts. It has the effects of sterilization and moisturizing, and does not have a negative effect on human health. Many patents or documents combine 1,2-hexanediol and other antimicrobial substances to play an antimicrobial role. Procter & Gamble adds 1,2-hexanediol to deodorants and antiperspirants, and the deodorants / antiperspirants obtained are more outstanding in deodorization / antiperspirant, and have better skin feel and transparency, and are gentle on the skin. Oshoff Soft in the United States adds 1,2-hexanediol to eyelid scrubs, and Givaudan Co., Ltd. and FANCL Co., Ltd. of Japan also add 1,2-hexanediol to skin care compositions to replace other bactericidal preservatives. Dow Global Technologies uses 1,2-hexanediol instead of alcohol to add to perfumes, which reduces irritation to the skin and, due to its excellent solvent and solubilizing ability, reduces the use of surfactants and can also obtain products with higher stability. Chinese cosmetics companies also add 1,2-hexanediol to cosmetics, which has bactericidal and preservative effects and is less irritating to the skin, improving the safety of skin care products. In terms of application in the pharmaceutical industry, 1,2-hexanediol is mainly used as a chemical raw material in the pharmaceutical industry, providing a basis for the development and utilization of downstream products.

[0004] At present, the industrial production of 1,2-alkyl diols all uses hydrogen peroxide and formic acid to react first to generate peroxyformic acid, which is then catalytically reacted with normal olefins to obtain 1,2-diol and its formate (1), which is then hydrolyzed with sodium hydroxide to obtain 1,2-diol (2).

[0005]

[0006] This process has obvious disadvantages, which are mainly manifested in the following aspects: 1) Peroxyformic acid is produced during the reaction, which is difficult to control and can easily explode if not handled properly, posing a major threat to production safety; 2) As people have higher and higher requirements for production safety, the demand for raw materials from natural renewable sources is extremely urgent.

[0007] In recent years, natural bioactive substances have attracted much attention due to their renewable, safe, environmentally friendly, abundant sources and biodegradability.

[0008] At present, the raw materials for producing diols are all petrochemical sources. There is no technological breakthrough in the production and supply of 1,2-diols from bio-based sources. Bio-based diols are a type of raw material synthesized through biological or chemical processes using bio-renewable resources as raw materials. Bio-based raw materials avoid dependence on petrochemical resources, have two functions of low carbon and carbon fixation, and are a type of sustainable polymer material. However, the current use of bio-based cosmetic raw materials is very small. Therefore, bio-based raw materials will be one of the important directions for future development in this field. Therefore, it is urgent to develop a bio-based and sustainable 1,2-alkyl diol preparation process. Summary of the invention

[0009] The purpose of the present invention is to provide a method for producing bio-based diols, avoiding the use of petrochemical α-olefins, using naturally derived fatty acids as raw materials, converting them into 2-hydroxy fatty acids through biological or chemical methods, and reducing them to obtain bio-based 1,2-diols. This technology has the advantages of a wide source of raw materials, sustainability, and high purity. In product applications, it exhibits the characteristics of few impurities, low irritation, and mild formula.

[0010] The purpose of the present invention and the solution to the technical problem are achieved by adopting the following technical solutions.

[0011] One aspect of the present invention provides a method for producing 1,2-diol, characterized in that the method is: a method for reducing 2-hydroxy fatty acid or its derivatives by a reduction method to obtain 1,2-diol, wherein the 2-hydroxy fatty acid or its derivatives have the following general formula:

[0012]

[0013] Wherein, R1 is: OH, Cl, Br, I, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, tert-butoxy;

[0014] R2 is: formyl, acetyl, propionyl, butyryl, methoxyl, ethoxyl, propoxyl, tert-butoxyl;

[0015] R3 is: a C4-C22 saturated or unsaturated alkyl group;

[0016] The reduction method includes borohydride reduction method, metallic sodium reduction method, lithium aluminum tetrahydride reduction method and catalytic hydrogenation method.

[0017] Preferably, the 1,2-diol includes 1,2-hexanediol, 1,2-octanediol, 1,2-decanediol, 1,2-dodecanediol, 1,2-tetradecanediol, 1,2-hexadecanediol, 1,2-octadecanediol, 1,2-behenediol, 1,2-docosahexadecane and 1,2-tetracosanediol.

[0018] Preferably, the 2-hydroxy fatty acid or its derivative includes 2-hydroxycaproic acid, 2-hydroxyoctanoic acid, 2-hydroxydecanoic acid, 2-hydroxylauric acid, 2-hydroxymyristic acid, 2-hydroxypalmitic acid, 2-hydroxystearic acid, 2-hydroxyarachidic acid, 2-hydroxybehenic acid, 2-hydroxyoleic acid, 2-hydroxylinoleic acid, 2-hydroxylinolenic acid, 2-fatty acylhydroxycaproic acid, 2-fatty acylhydroxyoctanoic acid, 2-acetylhydroxydecanoic acid, 2-acetylhydroxylauric acid, 2-acetylhydroxymyristic acid and their esters.

[0019] Preferably, the borohydride reduction method specifically comprises the following steps: adding THF and 2-hydroxy fatty acid or its derivative into a three-necked flask with a stirrer, a thermometer and a condenser, adding reducing agent powder under stirring, stirring the suspension at 65° C. for 15 minutes, then adding organic alcohol dropwise, and finally reacting under reflux, cooling to room temperature and neutralizing with HCl, separating the organic phase, extracting the aqueous phase with ethyl acetate, combining the organic phases, drying with anhydrous MgSO4, concentrating to obtain an oily substance, and performing reduced pressure distillation to obtain the product 1,2-diol;

[0020] The 2-hydroxy fatty acid or its derivative is 2-hydroxycaproic acid, 2-hydroxyoctanoic acid, 2-hydroxydecanoic acid, 2-hydroxylauric acid, 2-hydroxymyristic acid, 2-hydroxypalmitic acid, 2-hydroxystearic acid, 2-hydroxyarachidic acid, 2-hydroxybehenic acid, 2-hydroxyoleic acid, 2-hydroxylinoleic acid, 2-hydroxylinolenic acid, 2-fatty acyl hydroxycaproic acid, 2-fatty acyl hydroxyoctanoic acid, 2-acetylhydroxydecanoic acid, 2-acetylhydroxylauric acid, 2-acetylhydroxymyristic acid and its ester.

[0021] The reducing agent is sodium borohydride or potassium borohydride;

[0022] The organic alcohol is methanol or ethanol.

[0023] Preferably, the borohydride reduction method specifically comprises the following steps: adding THF and 2-hydroxyhexanoic acid to a three-necked flask with a stirrer, a thermometer and a condenser, adding LiAlH4 powder in batches under stirring, reflux reaction, cooling to 0°C, adding ethyl acetate dropwise, recovering THF, adding ethyl acetate and saturated brine, separating the organic phase, extracting the aqueous phase twice with ethyl acetate, combining the organic phases, drying over anhydrous MgSO4, concentrating to obtain an oily substance, and performing reduced pressure distillation to obtain the product 1,2-diol;

[0024] The 2-hydroxy fatty acid ester or its derivative is 2-hydroxycaproic acid, 2-hydroxyoctanoic acid, 2-hydroxydecanoic acid, 2-hydroxylauric acid, 2-hydroxymyristic acid, 2-hydroxypalmitic acid, 2-hydroxystearic acid, 2-hydroxyarachidic acid, 2-hydroxybehenic acid, 2-hydroxyoleic acid, 2-hydroxylinoleic acid, 2-hydroxylinolenic acid, 2-fatty acyl hydroxycaproic acid, 2-fatty acyl hydroxyoctanoic acid, 2-acetylhydroxydecanoic acid, 2-acetylhydroxylauric acid, 2-acetylhydroxymyristic acid and esters thereof.

[0025] Preferably, the metallic sodium reduction method specifically comprises the following steps: placing sodium and toluene in a flask, heating the flask in an oil bath until the sodium melts, then starting a stirrer, and when the mixture cools to 60° C., rapidly dropping a solution of 2-hydroxy fatty acid ester or its derivative, ethanol, and ethanol from a separatory funnel, heating until the sodium is completely dissolved, evaporating the ethanol, adding deionized water, separating the liquids, washing with water, recovering toluene by vacuum distillation, and then vacuum distilling to obtain the product 1,2-diol;

[0026] The 2-hydroxy fatty acid ester or its derivative is 2-hydroxycaproic acid, 2-hydroxyoctanoic acid, 2-hydroxydecanoic acid, 2-hydroxylauric acid, 2-hydroxymyristic acid, 2-hydroxypalmitic acid, 2-hydroxystearic acid, 2-hydroxyarachidic acid, 2-hydroxybehenic acid, 2-hydroxyoleic acid, 2-hydroxylinoleic acid, 2-hydroxylinolenic acid, 2-fatty acyl hydroxycaproic acid, 2-fatty acyl hydroxyoctanoic acid, 2-acetylhydroxydecanoic acid, 2-acetylhydroxylauric acid, 2-acetylhydroxymyristic acid and esters thereof.

[0027] Preferably, the lithium aluminum tetrahydride reduction method specifically comprises the following steps: adding toluene to a flask, adding red aluminum solution thereto after nitrogen is passed through for half an hour, cooling with ice water and stirring evenly, dripping a mixed solution of 2-hydroxy fatty acid ester or its derivative and toluene, reacting at the reflux temperature of toluene after the dripping is completed, slowly dripping concentrated hydrochloric acid thereto after the reactant is cooled to room temperature, initially a large amount of gas escapes and a large amount of precipitation is generated, adding a total of 18 ml of concentrated hydrochloric acid, adding ethyl acetate to the solid-liquid mixture, stirring and washing, and precipitating in the lower layer after standing, which is viscous, separating the upper clear liquid, rotary evaporating until no liquid is distilled out, and distilling under reduced pressure to obtain the product 1,2-diol;

[0028] The 2-hydroxy fatty acid ester or its derivative is 2-hydroxycaproic acid, 2-hydroxyoctanoic acid, 2-hydroxydecanoic acid, 2-hydroxylauric acid, 2-hydroxymyristic acid, 2-hydroxypalmitic acid, 2-hydroxystearic acid, 2-hydroxyarachidic acid, 2-hydroxybehenic acid, 2-hydroxyoleic acid, 2-hydroxylinoleic acid, 2-hydroxylinolenic acid, 2-fatty acyl hydroxycaproic acid, 2-fatty acyl hydroxyoctanoic acid, 2-acetylhydroxydecanoic acid, 2-acetylhydroxylauric acid, 2-acetylhydroxymyristic acid and esters thereof.

[0029] Preferably, the catalytic hydrogenation method specifically comprises the following steps: adding a copper-based catalyst and 1,2-diol into a reactor, introducing a mixed gas of 5% H2 / 95% N2, controlling the flow rate to be 50-100 mL / min, and activating at 140-300° C. for 10-50 h; adjusting the reaction temperature of the reactor to 120-200° C. and the hydrogen pressure to 5-15 MPa, adding 2-hydroxy fatty acid ester or its derivative and 1,2-diol into the reactor for reaction, and reacting for 3-30 h to obtain 1,2-diol;

[0030] The 2-hydroxy fatty acid ester or its derivative is 2-hydroxycaproic acid, 2-hydroxyoctanoic acid, 2-hydroxydecanoic acid, 2-hydroxylauric acid, 2-hydroxymyristic acid, 2-hydroxypalmitic acid, 2-hydroxystearic acid, 2-hydroxyarachidic acid, 2-hydroxybehenic acid, 2-hydroxyoleic acid, 2-hydroxylinoleic acid, 2-hydroxylinolenic acid, 2-fatty acyl hydroxycaproic acid, 2-fatty acyl hydroxyoctanoic acid, 2-acetylhydroxydecanoic acid, 2-acetylhydroxylauric acid, 2-acetylhydroxymyristic acid and esters thereof.

[0031] Preferably, the raw material composition of the copper-based catalyst comprises the following components in mass percentage: CuO 40-70%, SiO2 10-40%, Al2O3 10-30% and MnO2 3-9%.

[0032] Another aspect of the present invention also discloses an application of 1,2-diol obtained according to the production method of 1,2-diol, wherein the application includes use in skin care products, such as skin care creams, lotions, oils, and toners; use in hair care products, such as hair oils, hair waxes, hair milks, and hair pastes; use in washing products, such as shampoo, hand soap, dishwashing detergent, and laundry detergent; and facial masks.

[0033] The expected effects and advantages of the present invention are as follows:

[0034] The production method of 1,2-diol provided by the present invention avoids the use of α-olefins from petrochemical sources, uses fatty acids from natural sources as raw materials, converts them into 2-hydroxy fatty acids through biological or chemical methods, and reduces them to obtain bio-based 1,2-diol. This technology has the advantages of wide raw material sources, sustainability, and high purity. In product applications, it exhibits the characteristics of few impurities, low irritation, and mild formula.

[0035] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the preferred embodiments of the present invention are described in detail as follows. DETAILED DESCRIPTION

[0036] In order to make the technical means, creative features, objectives and effects of the present invention easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] Examples 1 to 5 Method for synthesizing 2-hydroxy fatty acids from fatty acids

[0038] Synthesis of 2-Hydroxyhexanoic Acid and Its Esters

[0039] In a three-necked flask equipped with a stirrer, a thermometer and a condenser, add 200 mL of phosphate buffer solution (pH = 7.5, 0.1), water, 5 g of n-caproic acid, and 10 g of DMSO, and add 1 g of P450 enzyme solution under stirring, and stir the suspension overnight at room temperature. Extract with 100 mL of ethyl acetate three times, combine, concentrate, and dry over anhydrous Na2SO4. Concentrate to obtain an oily substance and perform vacuum distillation to obtain a product with a 2-hydroxycaproic acid content of 93.6% and a yield of 85.1%.

[0040] Synthesis of 2-Hydroxyoctanoic Acid and 2-Acetoxyoctanoic Acid

[0041] In a three-necked flask equipped with a stirrer, a thermometer and a condenser, add 200 mL of phosphate buffer solution (pH = 7.5, 0.1), water, 6 g of octanoic acid and 12 g of DMSO, add 1 g of P450 enzyme solution under stirring, and stir the suspension overnight at room temperature. Extract with 100 mL of ethyl acetate three times, combine, concentrate, dry over anhydrous Na2SO4, concentrate to obtain an oily substance, and perform vacuum distillation to obtain a product with a 2-hydroxyoctanoic acid content of 91.2% and a yield of 80.6%.

[0042] Synthesis of 2-Hydroxylauric Acid

[0043] In a three-necked flask equipped with a stirrer, a thermometer and a condenser, add 200 mL of phosphate buffer solution (pH = 7.5, 0.1), water, 6 g of lauric acid, and 12 g of DMSO, and add 1 g of P450 enzyme solution under stirring, and stir the suspension overnight at room temperature. Extract with 100 mL of ethyl acetate three times, combine, concentrate, and dry over anhydrous Na2SO4. Concentrate to obtain an oily substance and perform vacuum distillation to obtain a product with a 2-hydroxyoctanoic acid content of 67.2% and a yield of 69.6%.

[0044] Synthesis of 2-Hydroxydecanoic Acid

[0045] In a three-necked flask equipped with a stirrer, a thermometer and a condenser, 6 g of decanoic acid and 0.2 g of chlorosulfonic acid were added, and the temperature was raised to 120°C while stirring. Oxygen: chlorine (volume ratio of 1:2) was introduced for 10 hours. The mixture was washed with water, washed with sodium bicarbonate aqueous solution, and washed with water until neutral. The oily substance was concentrated to obtain a 2-hydroxyoctanoic acid content of 96.2% and a yield of 92.6%.

[0046] Synthesis of 2-Hydroxypalmitic Acid

[0047] Add 20 g of palmitic acid and 1.2 g of chlorosulfonic acid into a three-necked flask equipped with a stirrer, a thermometer and a condenser. Heat to 120°C while stirring, introduce oxygen: chlorine (volume ratio of 1:2). The reaction is completed in 11 hours. Wash with water, sodium bicarbonate aqueous solution, and water until neutral, and concentrate to obtain an oily substance with a 2-hydroxypalmitic acid content of 92.2% and a yield of 91.1%.

[0048] Example 6-7 Synthesis of 2-Hydroxy Fatty Acid Ester

[0049] Synthesis of Ethyl 2-Hydroxydecanoate

[0050] In a three-necked flask equipped with a stirrer, a thermometer and a condenser, add 20 g of 2-hydroxydecanoic acid, 200 mL of ethanol and 5 g of concentrated sulfuric acid, heat and reflux for 5 h, recover the ethanol, neutralize with sodium bicarbonate, extract three times with 50 mL of ethyl acetate, combine, concentrate, dry over anhydrous MgSO4, concentrate to obtain an oily substance, and distill under reduced pressure to obtain the product ethyl 2-hydroxydecanoate with a content of 96.2% and a yield of 97.3%.

[0051] Synthesis of 2-Hydroxyhexanoic Acid Methyl Ester

[0052] In a single-mouth bottle with a magnetic stirrer and a thermometer, add 2 g of 2-hydroxyhexanoic acid, 20 mL of methanol, and 0.5 g of sulfuric acid, heat and reflux for 5 hours, neutralize with sodium bicarbonate, recover methanol, wash with water, and concentrate to obtain methyl 2-hydroxyhexanoate with a yield of 99.2% and a content of 98.3%.

[0053] Example 8-9 Synthesis of 2-acetyl fatty acid ester

[0054] Synthesis of 2-acetoxyoctanoic acid

[0055] In a single-mouth bottle, add 10g of 2-hydroxyoctanoic acid, 50mL of acetic acid, and 0.5g of sodium acetate, heat and reflux for 3 hours, recover acetic anhydride, add the residue into water, heat to 50℃ and react for 2 hours, separate, wash with water, and concentrate to obtain methyl 2-acetoxyhexanoate, with a yield of 79.2% and a content of 93.2%.

[0056] Synthesis of methyl 2-acetoxyhexanoate

[0057] In a single-mouth bottle, add 10g of methyl 2-hydroxyhexanoate, 50mL of acetic acid, and 0.5g of sodium acetate, recover acetic anhydride, add the residue into water, heat to 50°C and react for 10 minutes, separate, wash with water, and concentrate to obtain methyl 2-acetoxyhexanoate with a yield of 89.2% and a content of 91.2%.

[0058] Example 10-11 Method for preparing 1,2-diol using NaBH4 as a reducing agent

[0059] Synthesis of 1,2-Decanediol

[0060] Add 500 mL of THF and 50 g of methyl 2-hydroxydecanoate to a three-necked flask with a stirrer, a thermometer and a condenser, add 50 g of NaBH4 powder while stirring, and stir the suspension at 65°C for 15 min. Then add 50 mL of methanol dropwise, and finally react under reflux for 4 h. After cooling to room temperature, neutralize with 100 mL of 2N HC1. Separate the organic phase, extract the aqueous phase with 200 mL of ethyl acetate three times, combine the organic phases, dry with anhydrous MgSO4, concentrate to obtain an oily substance, and perform vacuum distillation to obtain a product with a 1,2-decanediol content of 99.5% and a yield of 88.7%.

[0061] Synthesis of 1,2-octanediol

[0062] Add 500 mL of THF and 45 g of methyl 2-hydroxyoctanoate to a three-necked flask with a stirrer, a thermometer and a condenser, add 50 g of NaBH4 powder while stirring, and stir the suspension at 65°C for 15 min. Then add 50 mL of methanol dropwise, and finally react for 4 h under reflux. After cooling to room temperature, neutralize with 100 mL of 2N HCl. Separate the organic phase, extract the aqueous phase with 200 mL of ethyl acetate three times, combine the organic phases, dry with anhydrous MgSO4, concentrate to obtain an oily substance, and perform vacuum distillation to obtain a product with a 1,2-decanediol content of 99.7% and a yield of 82.1%.

[0063] Example 12 Method for preparing 1,2-diol using KBH4 as a reducing agent

[0064] Synthesis of 1,2-octanediol

[0065] Add 500mL of THF and 50g of ethyl 2-hydroxyoctanoate to a three-necked flask with a stirrer, a thermometer and a condenser, add 55g of KBH4 powder while stirring, and stir the suspension at 65°C for 15min. Then add 50mL of ethanol dropwise, and finally react for 4h under reflux. After cooling to room temperature, neutralize with 100mL of 2N HC1. Separate the organic phase, extract the aqueous phase with 200mL of ethyl acetate three times, combine the organic phases, dry with anhydrous MgSO4, concentrate to obtain an oily substance, and perform vacuum distillation to obtain a product with a 1,2-octanediol content of 99.7% and a yield of 92.5%.

[0066] Example 13 Method for preparing 1,2-diol using KBH4 as a reducing agent

[0067] Synthesis of 1,2-Hexanediol

[0068] In a three-necked flask equipped with a stirrer, a thermometer and a condenser, 500 mL of anhydrous THF and 50 g of 2-hydroxyhexanoic acid were added, and 40 g of LiAlH4 powder was added in batches under stirring. The reaction was refluxed for 5 h. After cooling to 0°C, 60 mL of ethyl acetate was added dropwise, THF was recovered, 200 ml of ethyl acetate and 100 mL of saturated brine were added, the organic phase was separated, and the aqueous phase was extracted twice with 100 mL of ethyl acetate. The organic phases were combined, dried over anhydrous MgSO4, and concentrated to obtain an oily substance for vacuum distillation to obtain a product with a 1,2-hexanediol content of 99.6% and a yield of 96.3%.

[0069] Example 13 Method for preparing 1,2-diol using Na as a reducing agent

[0070] Synthesis of 1,2-octanediol

[0071] Place 60g of sodium and 200mL of toluene in a flask. Heat the flask in an oil bath until the sodium melts, then start the agitator. When the mixture cools to 60°C, quickly drop 100g of ethyl 2-hydroxyhexanoate in a solution of 150mL of ethanol and 500mL of ethanol from a separatory funnel, raise the temperature until the sodium is completely dissolved, evaporate the ethanol, add 200mL of deionized water, separate the liquids, wash with 100mL of water, recover toluene by vacuum distillation, and then vacuum distill to obtain a product with a 1,2-octanediol content of 99.5% and a yield of 91.5%.

[0072] Example 14 Method for preparing 1,2-diol using red aluminum as a reducing agent

[0073] Synthesis of 1,2-Dodecanediol

[0074] Add 10ml of toluene to the flask, and add 25g of red aluminum solution after passing nitrogen for half an hour. After cooling with ice water and stirring evenly, add a mixed solution of 5.8g of 2-hydroxylauric acid ethyl ester and 10ml of toluene. After the addition is complete, react at the reflux temperature of toluene for 10 hours. After the reactant is cooled to room temperature, concentrated hydrochloric acid is slowly added thereto. Initially, a large amount of gas escapes and a large amount of precipitation is produced. A total of 18ml of concentrated hydrochloric acid is added. Add 50ml of ethyl acetate to this solid-liquid mixture, stir and wash, and precipitate in the lower layer after standing. It is viscous, separate the supernatant, rotary evaporate until no liquid is distilled out, and obtain the product 1,2-dodecanediol with a content of 99.3% and a yield of 89.7%.

[0075] Example 15 Method for preparing 1,2-diol by catalytic hydrogenation

[0076] Synthesis of 1,2-Hexanediol

[0077] The catalyst prepared according to the method of CN114192155A was loaded into a 1mm×700mm stainless steel tubular reactor, and a certain volume of 1,2-hexanediol was added. A mixed gas of 5% H2 / 95% N2 was introduced at 300°C and atmospheric pressure for reduction for 6h. The H2 flow rate was controlled to be 100mL / min. 1,2-hexanediol and 2-hydroxyhexanoic acid ethyl ester were mixed in a volume ratio of 1:2. The reaction mixture was heated to 200°C at a pressure of 2MPa, a hydrogen-ester ratio of 330 (mol), a temperature of 205°C, and a liquid hourly space velocity of 1.2h. -1 The reaction was carried out under the following conditions, and the obtained 1,2-hexanediol was subjected to reduced pressure distillation to obtain a product 1,2-hexanediol with a content of 99.7% and a yield of 96.6%.

[0078] Comparative Examples 16-18 Method for preparing 1,2-diol from olefins

[0079] Synthesis of 1,2-Hexanediol

[0080] In a three-necked flask equipped with a stirrer, a thermometer and a condenser, add 100 mL of formic acid and 70 g of n-hexene, raise the temperature to 70°C, add 60 g of 50% hydrogen peroxide dropwise, continue stirring for 2 hours after the addition is complete, recover the formic acid, add water to the residual liquid for washing, add 30 g of 30% sodium hydroxide aqueous solution, raise the temperature to 45°C, react for 15 minutes, neutralize to neutrality, separate the liquids, wash with water, dry, concentrate, and distill under reduced pressure to obtain 1,2-hexanediol with a content of 99.7%.

[0081] Synthesis of 1,2-octanediol

[0082] Add 100 mL of formic acid and 75 g of n-octene into a three-necked flask with a stirrer, a thermometer and a condenser, raise the temperature to 70°C, add 60 g of 50% hydrogen peroxide dropwise, continue stirring for 2 hours after the addition is complete, recover the formic acid, add water to the residual liquid for washing, add 28 g of 30% sodium hydroxide aqueous solution, raise the temperature to 45°C, react for 15 minutes, neutralize to neutrality, separate the liquids, wash with water, dry, concentrate, and distill under reduced pressure to obtain 1,2-octanediol with a content of 99.5%.

[0083] Synthesis of 1,2-Decanediol

[0084] In a three-necked flask equipped with a stirrer, a thermometer and a condenser, add 100 mL of formic acid and 80 g of n-decene, raise the temperature to 70°C, add 60 g of 50% hydrogen peroxide dropwise, continue stirring for 2 hours after the addition is complete, recover the formic acid, add water to the residual liquid for washing, add 26 g of 30% sodium hydroxide aqueous solution, raise the temperature to 45°C, react for 15 minutes, neutralize to neutrality, separate the liquids, wash with water, dry, concentrate, and distill under reduced pressure to obtain 1,2-decanediol with a content of 99.6%.

[0085] Test Example 19 Comparison of the Quality of Bio-based 1,2-diols and Chemically Originated 1,2-diols

[0086] Table 1 Comparison of product quality of 1,2-diols from petroleum-based and bio-based sources

[0087] Example 1,2-Alkyl glycol Source of raw materials Aldehyde content Ketone Content odor Comparative Example 16 1,2-Hexanediol n-Hexene 0.11％ 0.07％ Slight odor Embodiment 15 1,2-Hexanediol 2-Hydroxyhexanoic acid ND ND Odorless Comparative Example 17 1,2-Octanediol n-Octene 0.09％ 0.13％ Slight odor Embodiment 13 1,2-Octanediol 2-Hydroxyoctanoic acid ND ND Odorless Comparative Example 18 1,2-Decanediol n-Decene 0.21％ 0.05％ Slight odor Example 10 1,2-Decanediol 2-Hydroxydecanoic acid ND ND Odorless

[0088] From the results in Table 1, it can be seen that ketones and aldehydes were detected in petroleum-based 1,2-diols, while ketones and aldehydes were detected in bio-based 1,2-diols. Therefore, bio-based products have lower odor.

[0089] Test Example 20 Irritation test of petroleum-based and bio-based 1,2-diols used in facial masks

[0090] The samples in Table 1 above were prepared into facial masks according to the formula in Table 2 below, and then a double-blind irritation test was conducted.

[0091] Table 2 Mask formula

[0092]

[0093]

[0094] Table 3 Comparison of facial mask irritation

[0095] Example 1,2-Alkyl glycol Source of raw materials stinging or burning sensation Comparative Example 16 1,2-Hexanediol n-Hexene ***** Embodiment 15 1,2-Hexanediol 2-Hydroxyhexanoic acid ** Comparative Example 17 1,2-Octanediol n-Octene ***** Embodiment 13 1,2-Octanediol 2-Hydroxyoctanoic acid ** Comparative Example 18 1,2-Decanediol n-Decene ***** Example 10 1,2-Decanediol 2-Hydroxydecanoic acid ***

[0096] From the above evaluation results, it can be seen that bio-based 1,2-diol products used in facial mask products have lower irritation and burning sensation, and are gentler and safer.

[0097] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modifications to equivalent embodiments of equivalent changes by using the methods and technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A method for producing 1,2-diol, characterized in that: The method is: a method of reducing 2-hydroxy fatty acid or its derivatives to obtain 1,2-diol by a reduction method, wherein the general formula of the 2-hydroxy fatty acid or its derivatives is as follows: Wherein, R1 is: OH, Cl, Br, I, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, tert-butoxy; R2 is: formyl, acetyl, propionyl, butyryl, methoxyl, ethoxyl, propoxyl, tert-butoxyl; R3 is: a C4-C22 saturated or unsaturated alkyl group; The reduction method includes borohydride reduction method, metallic sodium reduction method, lithium aluminum tetrahydride reduction method and catalytic hydrogenation method.

2. The method for producing 1,2-diol according to claim 1, characterized in that The 1,2-diols include 1,2-hexanediol, 1,2-octanediol, 1,2-decanediol, 1,2-dodecanediol, 1,2-tetradecanediol, 1,2-hexadecanediol, 1,2-octadecanediol, 1,2-eicosanediol, 1,2-docosandiol, and 1,2-tetracosandiol.

3. The method for producing 1,2-diol according to claim 1, characterized in that: The 2-hydroxy fatty acid or its derivative includes 2-hydroxyhexanoic acid, 2-hydroxyoctanoic acid, 2-hydroxydecanoic acid, 2-hydroxydecanoic acid methyl ester, 2-hydroxydecanoic acid ethyl ester, 2-hydroxyoctanoic acid methyl ester, 2-hydroxyoctanoic acid ethyl ester, 2-hydroxyhexanoic acid ethyl ester, 2-hydroxylauric acid ethyl ester, 2-hydroxylauric acid, 2-hydroxymyristic acid, 2-hydroxypalmitic acid, 2-hydroxystearic acid, 2-hydroxyarachidic acid, 2-hydroxybehenic acid, 2-hydroxyoleic acid, 2-hydroxylinoleic acid, 2-hydroxylinolenic acid, 2-fatty acyloxyhexanoic acid, 2-fatty acyloxyoctanoic acid, 2-acetoxydecanoic acid, 2-acetoxylauric acid, and 2-acetoxymyristic acid.

4. The method for producing 1,2-diol according to claim 1, characterized in that: The borohydride reduction method specifically comprises the following steps: adding THF and 2-hydroxy fatty acid or its derivative into a three-necked flask with a stirrer, a thermometer and a condenser, adding reducing agent powder under stirring, stirring the suspension at 65° C. for 15 minutes, then adding organic alcohol dropwise, and finally reacting under reflux, cooling to room temperature and neutralizing with HCl, separating the organic phase, extracting the aqueous phase with ethyl acetate, combining the organic phases, drying with anhydrous MgSO4, concentrating to obtain an oily substance, and performing reduced pressure distillation to obtain the product 1,2-diol; The 2-hydroxy fatty acid or its derivative is 2-hydroxycaproic acid, 2-hydroxyoctanoic acid, 2-hydroxydecanoic acid, 2-hydroxylauric acid, 2-hydroxymyristic acid, 2-hydroxypalmitic acid, 2-hydroxystearic acid, 2-hydroxyarachidic acid, 2-hydroxybehenic acid, 2-hydroxyoleic acid, 2-hydroxylinoleic acid, 2-hydroxylinolenic acid, 2-fatty acyl hydroxycaproic acid, 2-fatty acyl hydroxyoctanoic acid, 2-acetylhydroxydecanoic acid, 2-acetylhydroxylauric acid, 2-acetylhydroxymyristic acid and its ester. The reducing agent is sodium borohydride or potassium borohydride; The organic alcohol is methanol, ethanol, propanol, isopropanol, n-butanol, and tert-butanol.

5. The method for producing 1,2-diol according to claim 1, characterized in that: The borohydride reduction method specifically comprises the following steps: adding THF and 2-hydroxy fatty acid ester or its derivative into a three-necked flask with a stirrer, a thermometer and a condenser, adding LiAlH4 powder in batches under stirring, reflux reaction, cooling to 0°C, adding ethyl acetate dropwise, recovering THF, adding ethyl acetate and saturated saline, separating the organic phase, extracting the aqueous phase with ethyl acetate twice, combining the organic phases, drying with anhydrous MgSO4, concentrating to obtain an oily substance, and performing reduced pressure distillation to obtain the product 1,2-diol; The 2-hydroxy fatty acid ester or its derivative is 2-hydroxycaproic acid, 2-hydroxyoctanoic acid, 2-hydroxydecanoic acid, 2-hydroxylauric acid, 2-hydroxymyristic acid, 2-hydroxypalmitic acid, 2-hydroxystearic acid, 2-hydroxyarachidic acid, 2-hydroxybehenic acid, 2-hydroxyoleic acid, 2-hydroxylinoleic acid, 2-hydroxylinolenic acid, 2-fatty acyl hydroxycaproic acid, 2-fatty acyl hydroxyoctanoic acid, 2-acetylhydroxydecanoic acid, 2-acetylhydroxylauric acid, 2-acetylhydroxymyristic acid and esters thereof.

6. The method for producing 1,2-diol according to claim 1, characterized in that: The metallic sodium reduction method specifically comprises the following steps: placing sodium and toluene in a flask, heating the flask in an oil bath until the sodium melts, then starting a stirrer, and when the mixture cools to 60° C., rapidly dropping a solution of 2-hydroxy fatty acid ester or its derivative, ethanol, and ethanol from a separatory funnel, heating until the sodium is completely dissolved, evaporating the ethanol, adding deionized water, separating the liquids, washing with water, recovering toluene by vacuum distillation, and then vacuum distilling to obtain the product 1,2-diol; The 2-hydroxy fatty acid ester or its derivative is 2-hydroxycaproic acid, 2-hydroxyoctanoic acid, 2-hydroxydecanoic acid, 2-hydroxylauric acid, 2-hydroxymyristic acid, 2-hydroxypalmitic acid, 2-hydroxystearic acid, 2-hydroxyarachidic acid, 2-hydroxybehenic acid, 2-hydroxyoleic acid, 2-hydroxylinoleic acid, 2-hydroxylinolenic acid, 2-fatty acyl hydroxycaproic acid, 2-fatty acyl hydroxyoctanoic acid, 2-acetylhydroxydecanoic acid, 2-acetylhydroxylauric acid, 2-acetylhydroxymyristic acid and esters thereof.

7. The method for producing 1,2-diol according to claim 1, characterized in that: The lithium aluminum tetrahydride reduction method specifically comprises the following steps: adding toluene to a flask, adding a red aluminum solution thereto after nitrogen is passed through for half an hour, cooling with ice water and stirring evenly, dripping a mixed solution of 2-hydroxy fatty acid ester or its derivative and toluene, reacting at the reflux temperature of toluene after the dripping is completed, slowly dripping concentrated hydrochloric acid thereto after the reactant is cooled to room temperature, initially a large amount of gas escapes and a large amount of precipitation is generated, adding a total of 18 ml of concentrated hydrochloric acid, adding ethyl acetate to the solid-liquid mixture, stirring and washing, and precipitating in the lower layer after standing, which is viscous, separating the upper clear liquid, rotary evaporating until no liquid is distilled out, and distilling under reduced pressure to obtain the product 1,2-diol; The 2-hydroxy fatty acid ester or its derivative is 2-hydroxycaproic acid, 2-hydroxyoctanoic acid, 2-hydroxydecanoic acid, 2-hydroxylauric acid, 2-hydroxymyristic acid, 2-hydroxypalmitic acid, 2-hydroxystearic acid, 2-hydroxyarachidic acid, 2-hydroxybehenic acid, 2-hydroxyoleic acid, 2-hydroxylinoleic acid, 2-hydroxylinolenic acid, 2-fatty acyl hydroxycaproic acid, 2-fatty acyl hydroxyoctanoic acid, 2-acetylhydroxydecanoic acid, 2-acetylhydroxylauric acid, 2-acetylhydroxymyristic acid and esters thereof.

8. The method for producing 1,2-diol according to claim 1, characterized in that: The catalytic hydrogenation method specifically comprises the following steps: adding a copper-based catalyst and 1,2-diol into a reactor, introducing a mixed gas of 5% H2 / 95% N2, controlling the flow rate to be 50-100 mL / min, and activating at 140-300° C. for 10-50 h; adjusting the reaction temperature of the reactor to 120-200° C. and the hydrogen pressure to 5-15 MPa, adding 2-hydroxy fatty acid ester or its derivative and 1,2-diol into the reactor for reaction, and reacting for 3-30 h to obtain 1,2-diol; The 2-hydroxy fatty acid ester or its derivative is 2-hydroxycaproic acid, 2-hydroxyoctanoic acid, 2-hydroxydecanoic acid, 2-hydroxylauric acid, 2-hydroxymyristic acid, 2-hydroxypalmitic acid, 2-hydroxystearic acid, 2-hydroxyarachidic acid, 2-hydroxybehenic acid, 2-hydroxyoleic acid, 2-hydroxylinoleic acid, 2-hydroxylinolenic acid, 2-fatty acyl hydroxycaproic acid, 2-fatty acyl hydroxyoctanoic acid, 2-acetylhydroxydecanoic acid, 2-acetylhydroxylauric acid, 2-acetylhydroxymyristic acid and esters thereof.

9. The method for producing 1,2-diol according to claim 8, characterized in that: The raw material composition of the copper-based catalyst comprises the following components in mass percentage: CuO 40-70%, SiO2 10-40%, Al2O3 10-30% and MnO2 3-9%.

10. Use of 1,2-diol obtained by the method for producing 1,2-diol according to any one of claims 1 to 9, characterized in that: The applications include use in skin care products, such as skin care creams, lotions, oils, and toners; use in hair care products, such as hair oils, hair waxes, hair milks, and hair pastes; use in washing products, such as shampoo, hand soap, dishwashing detergent, and laundry detergent; and facial masks.

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