A kind of synthesis process of ethylhexylglycerol

Abstract

The invention discloses a synthesis process of ethylhexylglycerol, and belongs to the technical field of organic synthesis of cosmetic additives. The synthesis process comprises the following steps: after mixing epichlorohydrin with 2-ethylhexanol, adding an inorganic base and heating to 60-70°C for catalytic reaction to obtain octyl glycidyl ether; the octyl glycidyl ether is passed from the lower end of a fixed bed reactor after vaporization treatment, and water is passed from the upper end of the fixed bed reactor to react with the octyl glycidyl ether in the fixed bed reactor to obtain ethylhexylglycerol. The present invention designs a new synthesis route of ethylhexylglycerol, with high yield, and uses a fixed bed reactor for synthesis, and the catalyst is easy to separate from the reaction system.

Description

Technical Field

[0001] The invention belongs to the technical field of organic synthesis of cosmetic additives, and particularly relates to a synthesis process of ethylhexylglycerin. Background Art

[0002] Ethylhexylglycerin, also known as octoxyglycerin, is a new type of multifunctional daily chemical product additive. It has a certain bactericidal ability and can be used as an armpit deodorant. It has moisturizing and wetting functions and can be used in skin care products of various emulsified systems. It can also be added to surfactant system products for washing purposes. It can also be used in hair care products with conditioning, moisturizing, and nourishing effects. Compared with the toxicity risks of traditional preservatives, ethylhexylglycerin, as a green, non-irritating, and preservative-free "no-additive preservative" representative, is increasingly being used and studied.

[0003] Patent CN104817436B discloses a method for preparing high-purity ethylhexyl glycerol. The invention uses acetone and 2-ethylhexyl glycidyl ether as raw materials. Under the acid catalysis of boron trifluoride, 2-ethylhexyl glycidyl ether is ring-opened and condensed with acetone to generate 4-alkoxymethyl-1,3-dioxoalkane, which is then subjected to alkaline terminator and acid-catalyzed hydrolysis in sequence to prepare ethylhexyl glycerol. Although excessive use of the alkaline terminator can quench the catalytic effect of the acid catalyst, it has a certain inhibitory effect on the condensed 4-alkoxymethyl-1,3-dioxoalkane, so the maximum yield can only reach 89.1%. Patent CN112759507B discloses a method for preparing ethylhexylglycerol. The invention uses isooctyl alcohol and 3-chloro-1,2-propylene glycol as raw materials to react in an alkaline environment to obtain ethylhexylglycerol. 3-chloro-1,2-propylene glycol is prone to self-condensation in an alkaline environment, affecting the synthesis efficiency. Therefore, the yield of the invention can only reach 86.3% at most. Patent CN112661614B discloses a method for continuously synthesizing ethylhexylglycerol in a microchannel reactor. The method utilizes the good mass transfer and heat transfer performance of the microchannel reactor, uses isooctyl alcohol and 3-chloro-1,2-propylene glycol as raw materials, and further increases the yield of ethylhexylglycerol to 92.4%. Although the microchannel reactor increases the yield of ethylhexylglycerol, it cannot be mass-produced due to the batch limit and easy clogging of the microchannel reactor.

[0004] Therefore, a synthesis process of ethylhexyl glycerol which avoids self-condensation of polyhydroxy alcohols and has a high yield is designed, which has practical application value. Summary of the invention

[0005] In view of the deficiencies of the prior art, the present invention uses epichlorohydrin and 2-ethylhexanol as raw materials, condenses in an alkaline environment to obtain octyl glycidyl ether, and then hydrolyzes octyl glycidyl ether under acid catalysis to obtain ethylhexyl glycerol, so as to solve the problems in the background technology. Specifically, the technical solution of the present invention includes the following contents:

[0006] A synthesis process for ethylhexylglycerol, the synthesis process comprising the following steps:

[0007] After epichlorohydrin and 2-ethylhexanol are mixed, an inorganic base is added and the temperature is raised to 60-70°C for catalytic reaction to obtain octyl glycidyl ether;

[0008] The octyl glycidyl ether is introduced from the lower end of the fixed bed reactor after being vaporized, and water is introduced from the upper end of the fixed bed reactor to react with the octyl glycidyl ether in the fixed bed reactor to obtain ethylhexyl glycerol.

[0009] Furthermore, the molar ratio of the epichlorohydrin to the 2-ethylhexanol is 1:1 to 3. Compared with polyhydroxy alcohols such as 3-chloro-1,2-propylene glycol in the prior art, epichlorohydrin has no hydroxyl group at the ortho position of the chlorine atom and will not undergo self-condensation. In addition, the spatial position effect of the epoxy structure has a large steric hindrance for the condensation-etherification reaction in a strong alkaline environment, and it is not easy for the chloride ion to undergo an elimination reaction.

[0010] Furthermore, the inorganic base includes sodium hydroxide or potassium hydroxide.

[0011] Furthermore, the amount of the inorganic base is 1% to 5% of the mass of the 2-ethylhexanol.

[0012] Furthermore, the vaporization temperature of the octyl glycidyl ether is 80-90°C.

[0013] Furthermore, the feeding rate of the octyl glycidyl ether introduced from the lower end of the fixed bed reactor after vaporization is 0.5-0.9 ml / min, and the feeding rate of the water introduced from the upper end of the fixed bed reactor is 0.1-0.6 ml / min.

[0014] Furthermore, the fixed bed reactor is provided with a solid acid catalyst with a filling height of 5 to 12 cm. In the prior art, stirred tank reactors and microchannel reactors are mostly used for catalytic reactions. The stirred tank reactor has problems such as low catalytic synthesis yield and difficulty in separating the catalyst from the reaction system. Although the microchannel reactor has high mass transfer and heat transfer and high synthesis yield, it has a small processing batch and is prone to clogging. The present invention prepares a solid acidic silicon oxide compound by acid precipitation, and then immerses it in concentrated sulfuric acid to introduce sulfonic acid groups, thereby enhancing the proton acidity of the silicon oxide compound (i.e., the ability to release proton hydrogen), and prepares a solid acid catalyst, which is loaded in a fixed bed reactor. The catalyst is easily separated from the reaction system and the yield of catalytic synthesis is high.

[0015] Furthermore, the preparation of the solid acid catalyst comprises the following steps:

[0016] After the sodium silicate is dissolved, hydrochloric acid is added dropwise to react until no more precipitation is produced. The precipitate is collected by filtration and washed with deionized water, and then placed in a drying oven and dried at 160-180° C. for 6-10 hours to obtain a powdered solid.

[0017] The powdered solid is immersed in concentrated sulfuric acid for 2 to 5 hours and then dried at 80° C. for 12 hours to obtain the solid acid catalyst.

[0018] Furthermore, the conditions for the reaction of octyl glycidyl ether and water in the fixed bed reactor include a reaction residence time of 1 to 2 hours and a reaction temperature of 40 to 60°C.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] (1) The present invention designs a new synthesis route for ethylhexylglycerol, thereby avoiding the self-condensation of chloride ions with the hydroxyl groups in the structure thereof and the elimination reaction of chloride ions that are easily generated when polyhydroxy alcohols such as 3-chloro-1,2-propylene glycol are used for condensation in the prior art, thereby further improving the synthesis yield of ethylhexylglycerol.

[0021] (2) The solid acid catalyst designed and synthesized in the present invention is loaded in a fixed bed reactor. Compared with the kettle stirring method in the prior art that uses acid catalysts such as boron trifluoride for mixing, it has the advantage of easy separation of the reaction system and has a high yield comparable to that of a microchannel reactor. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The synthetic route of the present invention is shown in FIG.

[0023] Figure 2 This is a process equipment route diagram for synthesizing ethylhexylglycerol in Example 9.

[0024] Explanation of the accompanying drawings: 1-sodium hydroxide raw material; 2-process water; 3-formic acid raw material; 4-octyl glycidyl ether raw material; 5-reaction kettle; 6-formic acid preparation tank; 7-distillation kettle; 8-saponification kettle; 9-sodium hydroxide preparation tank; 10-distillation kettle; 11-preheater; 12-aging tower; 13-ethylhexylglycerin collection barrel. DETAILED DESCRIPTION

[0025] The technical solution of the present invention will be clearly and completely described below through the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0026] Unless otherwise specified, the raw materials and reagents used in the present invention are commercially available or can be prepared by known methods.

[0027] Embodiment 1:

[0028] The preparation of solid acid catalyst specifically includes the following process:

[0029] Weigh 30 g of sodium silicate and place it in a flask, add deionized water and stir to completely dissolve it to obtain a sodium silicate aqueous solution, add hydrochloric acid dropwise to the sodium silicate aqueous solution and continue stirring to react until no precipitate is precipitated to obtain a mixed solution, stop adding hydrochloric acid, filter the mixed solution to collect the filter cake, rinse the filter cake with deionized water until the pH value of the rinsed water is neutral, put the filter cake in a drying oven, heat to 160°C and dry for 6 hours to obtain a powdered solid, put all the powdered solid into concentrated sulfuric acid, stir and immerse at a speed of 100 r / min for 2 hours, evaporate under reduced pressure to remove the concentrated sulfuric acid, put the remaining solid into an oven, and dry it at 80°C for 12 hours to obtain a solid acid catalyst.

[0030] Embodiment 2:

[0031] The preparation of solid acid catalyst specifically includes the following process:

[0032] Weigh 30 g of sodium silicate and place it in a flask, add deionized water and stir to completely dissolve it to obtain a sodium silicate aqueous solution, add hydrochloric acid dropwise to the sodium silicate aqueous solution and continue stirring to react until no precipitate is precipitated to obtain a mixed solution, stop adding hydrochloric acid, filter the mixed solution to collect the filter cake, rinse the filter cake with deionized water until the pH value of the rinsed water is neutral, put the filter cake in a drying oven, heat to 165°C and dry for 6 hours to obtain a powdered solid, put all the powdered solid into concentrated sulfuric acid, stir and immerse at a speed of 100 r / min for 3 hours, evaporate under reduced pressure to remove the concentrated sulfuric acid, put the remaining solid into an oven, and dry it at 80°C for 12 hours to obtain a solid acid catalyst.

[0033] Embodiment 3:

[0034] The preparation of solid acid catalyst specifically includes the following process:

[0035] Weigh 30 g of sodium silicate and place it in a flask, add deionized water and stir to completely dissolve it to obtain a sodium silicate aqueous solution, add hydrochloric acid dropwise to the sodium silicate aqueous solution and continue stirring to react until no precipitate is precipitated to obtain a mixed solution, stop adding hydrochloric acid, filter the mixed solution to collect the filter cake, rinse the filter cake with deionized water until the pH value of the rinsed water is neutral, put the filter cake in a drying oven, heat to 175°C and dry for 8 hours to obtain a powdered solid, put all the powdered solid into concentrated sulfuric acid, stir and immerse at a speed of 100 r / min for 4 hours, evaporate under reduced pressure to remove the concentrated sulfuric acid, put the remaining solid into an oven, and dry it at 80°C for 12 hours to obtain a solid acid catalyst.

[0036] Embodiment 4:

[0037] The preparation of solid acid catalyst specifically includes the following process:

[0038] Weigh 30 g of sodium silicate and place it in a flask, add deionized water and stir to completely dissolve it to obtain a sodium silicate aqueous solution, add hydrochloric acid dropwise to the sodium silicate aqueous solution and continue stirring to react until no precipitate is precipitated to obtain a mixed solution, stop adding hydrochloric acid, filter the mixed solution to collect the filter cake, rinse the filter cake with deionized water until the pH value of the rinsed water is neutral, put the filter cake in a drying oven, heat to 180°C and dry for 10 hours to obtain a powdered solid, put all the powdered solid into concentrated sulfuric acid, stir and immerse at a speed of 100 r / min for 5 hours, evaporate under reduced pressure to remove the concentrated sulfuric acid, put the remaining solid in an oven, and dry it at 80°C for 12 hours to obtain a solid acid catalyst.

[0039] Embodiment 5:

[0040] A synthesis process of ethylhexylglycerol specifically comprises the following preparation process:

[0041] Weigh 1 mol of epichlorohydrin and 1 mol of 2-ethylhexanol, mix and stir evenly, add 1.3 g of sodium hydroxide and mix with them, then heat the reaction system to 60° C., start timing reaction for 3 hours, add an equal volume of deionized water to the reaction system after the reaction is completed, let it stand for separation to obtain an oil phase containing octyl glycidyl ether, and then rinse the oil phase with deionized water until the rinse liquid is neutral to obtain octyl glycidyl ether; load the solid acid catalyst in Example 1 into a fixed bed reactor, control the loading height of the solid acid catalyst to 5 cm, and control the temperature of the fixed bed reactor to The reaction mixture was heated to 40°C, and then octyl glycidyl ether was vaporized at 80°C and introduced into the fixed bed reactor from the lower end of the fixed bed reactor at a feeding rate of 0.5 ml / min. At the same time, water was introduced into the fixed bed reactor from the upper end of the fixed bed reactor at a feeding rate of 0.1 ml / min to react with octyl glycidyl ether. The residence time of the two materials was controlled to be 1 hour. After the reaction was completed, ethylhexyl glycerol was collected by reduced pressure distillation. According to chromatographic analysis, the yield of ethylhexyl glycerol was 90.71% and the purity was 99.03%.

[0042] Embodiment 6:

[0043] A synthesis process of ethylhexylglycerol specifically comprises the following preparation process:

[0044] Weigh 1 mol of epichlorohydrin and 2 mol of 2-ethylhexanol, mix and stir evenly, add 5.2 g of sodium hydroxide and mix with them, then heat the reaction system to 62° C., start timing reaction for 3 hours, add an equal volume of deionized water to the reaction system after the reaction is completed, let it stand for separation to obtain an oil phase containing octyl glycidyl ether, and then rinse the oil phase with deionized water until the rinse liquid is neutral to obtain octyl glycidyl ether; load the solid acid catalyst in Example 2 into a fixed bed reactor, control the loading height of the solid acid catalyst to 7 cm, and control the temperature of the fixed bed reactor to The reaction mixture was heated to 44°C, and then octyl glycidyl ether was vaporized at 83°C and introduced into the fixed bed reactor from the lower end of the fixed bed reactor at a feeding rate of 0.6 ml / min. At the same time, water was introduced into the fixed bed reactor from the upper end of the fixed bed reactor at a feeding rate of 0.2 ml / min to react with octyl glycidyl ether. The residence time of the two materials was controlled to be 1 hour. After the reaction was completed, ethylhexyl glycerol was collected by reduced pressure distillation. According to chromatographic analysis, the yield of ethylhexyl glycerol was 92.03% and the purity was 99.12%.

[0045] Embodiment 7:

[0046] A synthesis process of ethylhexylglycerol specifically comprises the following preparation process:

[0047] Weigh 1 mol of epichlorohydrin and 2 mol of 2-ethylhexanol, mix and stir evenly, add 5.2 g of potassium hydroxide and mix with them, then heat the reaction system to 67° C., start timing the reaction for 4 hours, add an equal volume of deionized water to the reaction system after the reaction is completed, let it stand for separation to obtain an oil phase containing octyl glycidyl ether, and then rinse the oil phase with deionized water until the rinse liquid is neutral to obtain octyl glycidyl ether; load the solid acid catalyst in Example 3 into a fixed bed reactor, control the loading height of the solid acid catalyst to 11 cm, and control the temperature of the fixed bed reactor to The reaction mixture was heated to 55°C, and then octyl glycidyl ether was vaporized at 88°C and introduced into the fixed bed reactor from the lower end of the fixed bed reactor at a feeding rate of 0.8 ml / min. At the same time, water was introduced into the fixed bed reactor from the upper end of the fixed bed reactor at a feeding rate of 0.5 ml / min to react with octyl glycidyl ether. The residence time of the two materials was controlled to be 2 h. After the reaction was completed, ethylhexyl glycerol was collected by reduced pressure distillation. According to chromatographic analysis, the yield of ethylhexyl glycerol was 93.81% and the purity was 99.45%.

[0048] Embodiment 8:

[0049] A synthesis process of ethylhexylglycerol specifically comprises the following preparation process:

[0050] Weigh 1 mol of epichlorohydrin and 3 mol of 2-ethylhexanol, mix and stir evenly, add 7.8 g of potassium hydroxide and mix with it, then heat the reaction system to 70°C, start timing reaction for 4 hours, add an equal volume of deionized water to the reaction system after the reaction is completed, let it stand for separation to obtain an oil phase containing octyl glycidyl ether, and then rinse the oil phase with deionized water until the rinse liquid is neutral to obtain octyl glycidyl ether; load the solid acid catalyst in Example 4 into a fixed bed reactor, control the loading height of the solid acid catalyst to 12 cm, and control the temperature of the fixed bed reactor to 60°C, then octyl glycidyl ether is vaporized at 90°C and introduced into the fixed bed reactor from the lower end of the fixed bed reactor at a feeding rate of 0.9 ml / min, and water is introduced into the fixed bed reactor from the upper end of the fixed bed reactor at a feeding rate of 0.6 ml / min to react with octyl glycidyl ether, and the residence time of the two materials is controlled to be 2h. After the reaction is completed, ethylhexyl glycerol is collected by reduced pressure distillation. According to chromatographic analysis, the yield of ethylhexyl glycerol is 92.54% and the purity is 99.28%.

[0051] Embodiment 9:

[0052] A synthesis process of ethylhexylglycerol specifically comprises the following preparation process:

[0053] Octyl glycidyl ether raw material 4 is introduced into reactor 5 through pipeline, formic acid raw material 3 is added into formic acid preparation tank 6 according to the molar ratio of 1:1 with octyl glycidyl ether raw material 4, and process water 2 is added for dilution, the diluted formic acid is introduced into reactor 5 through pipeline and mixed with octyl glycidyl ether and stirred evenly, the reactor 5 is heated to 70-75°C for reaction for 0.5h, and the reaction product is introduced into saponification reactor 8 through pipeline, sodium hydroxide raw material 1 is added into sodium hydroxide preparation tank 9 according to the same weight as the reaction product in saponification reactor 8, and process water 2 of the same volume as sodium hydroxide is added for pre-dissolution and dilution, and the prepared formic acid is introduced into reactor 5 through pipeline, and the formic acid is mixed with octyl glycidyl ether and stirred evenly, the reaction vessel 5 is heated to 70-75°C for reaction for 0.5h, and the reaction product is introduced into saponification reactor 8 through pipeline, the sodium hydroxide raw material 1 is added into sodium hydroxide preparation tank 9 according to the same weight as the reaction product in saponification reactor 8, and process water 2 of the same volume as sodium hydroxide is added for pre-dissolution and dilution, and the prepared formic acid is mixed with octyl glycidyl ether and stirred evenly, and the reaction vessel 5 is heated to 70-75°C for reaction for 0.5h, and the reaction product is introduced into saponification reactor 8 through pipeline, and the formic acid is mixed with octyl glycidyl ether and stirred evenly ... The sodium hydroxide solution is pumped into the saponification kettle 8 through a pipeline to mix with the reaction product, and then the saponification kettle is heated to 60-70°C and stirred for reaction for 0.5h, and then allowed to stand for stratification. The bottom aqueous phase layer is separated and enters the distillation kettle 7 for subsequent waste liquid treatment; the upper organic layer is passed into the distillation kettle 10 for vacuum distillation to obtain ethylhexylglycerol, and the collected ethylhexylglycerol is preheated by the preheater 11 and then passed into the aging tower 12, aged at 100°C to obtain colorless and odorless ethylhexylglycerol finished product, which is transferred to the ethylhexylglycerol collection barrel 13. According to chromatographic analysis, the yield of ethylhexylglycerol is 90.75% and the purity is 99.11%.

[0054] The above-described embodiments provide a detailed description of the technical solutions and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected.

Claims

1. A synthesis process for ethylhexylglycerol, characterized in that: The synthesis process comprises the following steps: After epichlorohydrin and 2-ethylhexanol are mixed, an inorganic base is added and the temperature is raised to 60-70°C for catalytic reaction to obtain octyl glycidyl ether; The octyl glycidyl ether is introduced from the lower end of the fixed bed reactor after being vaporized, and water is introduced from the upper end of the fixed bed reactor to react with the octyl glycidyl ether in the fixed bed reactor to obtain ethylhexyl glycerol; The fixed bed reactor is provided with a solid acid catalyst having a filling height of 5 to 12 cm; The preparation of the solid acid catalyst comprises the following steps: After the sodium silicate is dissolved, hydrochloric acid is added dropwise to react until no more precipitation is produced. The precipitate is collected by filtration and washed with deionized water, and then placed in a drying oven and dried at 160-180°C for 6-10 hours to obtain a powdered solid. The powdered solid is immersed in concentrated sulfuric acid for 2-5 hours and then dried at 80° C. for 12 hours to obtain the solid acid catalyst.

2. A synthesis process for ethylhexylglycerol according to claim 1, characterized in that: The molar ratio of the epichlorohydrin to the 2-ethylhexanol is 1:1-3.

3. A synthesis process for ethylhexylglycerol according to claim 1, characterized in that: The inorganic base is sodium hydroxide or potassium hydroxide.

4. A synthesis process for ethylhexylglycerol according to claim 1, characterized in that: The amount of the inorganic base is 1% to 5% of the mass of the 2-ethylhexanol.

5. A synthesis process for ethylhexylglycerol according to claim 1, characterized in that: The vaporization temperature of the octyl glycidyl ether is 80-90°C.

6. A synthesis process for ethylhexylglycerol according to claim 1, characterized in that: The feeding rate of the vaporized octyl glycidyl ether from the lower end of the fixed bed reactor is 0.5-0.9 ml / min, and the feeding rate of the water from the upper end of the fixed bed reactor is 0.1-0.6 ml / min.

7. A synthesis process for ethylhexylglycerol according to claim 1, characterized in that: The conditions for the reaction of octyl glycidyl ether and water in the fixed bed reactor are a reaction residence time of 1 to 2 hours and a reaction temperature of 40 to 60° C.

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