A method for preparing high purity bis-diglyceryl polyacyladipate-2

Abstract

The application provides a preparation method of high-purity double-diglycerol polyacyl adipate-2 and relates to the technical field of organic synthesis. The specific steps comprise the following steps: S1, putting double-diglycerol and mixed acid into a reaction kettle, vacuum heating and material mixing, water removal and mixing to obtain material; S2, adding a catalyst to the material to perform esterification reaction, and measuring the acid value after the reaction is completed; S3, after the acid value reaches the standard, cooling under a vacuum state, and filtering to obtain double-diglycerol polyacyl adipate-2. All raw materials except the catalyst are preheated and mixed under a vacuum state in the application, the mixing uniformity of the raw materials is improved, the raw materials are pretreated by water removal under a vacuum state, the water content of the material is ensured to be low, the reaction is promoted to proceed in a positive direction, the catalyst is added after the pretreatment by water removal to perform heat preservation reaction, the reaction is prevented from starting during the material mixing, the first step of the reaction is better controlled, the selectivity of the product is better, the side reaction is less, the purity of the final product is high, and the process flow is more controllable.

Description

Technical Field

[0001] This invention relates to the field of organic synthesis technology, and in particular to a method for preparing high-purity bis-diglycerol polyacryl adipate-2. Background Technology

[0002] Bis-diglyceride polyacryladiopate-2 is a plant-derived emulsifier, a pale yellow ointment-like solid, odorless or with a slight characteristic odor. It has good adhesion, durability and water retention properties, with a water absorption capacity of over 170%. It is mainly used as a moisturizer, conditioning agent and nonionic surfactant in skin care products, baby creams, lipsticks and other cosmetics.

[0003] Di-diglyceryl polyacryl adipate-2 is commonly used as a softener to replace traditional lanolin, locking in essential moisture and preventing water loss. Traditional lanolin's viscosity, color, and odor are easily affected by temperature, light, oxygen, and storage time, making it unstable. Products prepared using di-diglyceryl polyacryl adipate-2 exhibit better stability, a softer texture, better adhesion, and a refreshing, non-greasy feel. Furthermore, di-diglyceryl polyacryl adipate-2 is frequently used as an emulsifying and stabilizing surfactant / accelerator. Traditional surfactants, such as polysorbates, contain numerous ester bonds, which are easily hydrolyzed by residual lipases in inhibitors, producing free fatty acids that form insoluble particles, affecting product appearance and stability, and demonstrating chemical instability.

[0004] However, in the traditional synthesis of bis-diglycerol polyacryl adipate-2, the esterification reaction often uses acidic catalysts, which can easily corrode the reaction equipment, increasing production costs and equipment maintenance difficulties. In addition, the reaction process requires strict temperature control to avoid the generation of by-products, which places high demands on the production process. Subsequent steps such as alkaline washing and neutralization, and water washing are also required, which not only increases the complexity of the process but may also generate a large amount of wastewater, which is detrimental to environmental protection.

[0005] Existing technology CN120647533 A discloses a method for synthesizing bis-diglycerol polyacryl adipate-2, comprising: S1, mixing isostearic acid, caprylic / capric acid, stearic acid and 12-hydroxystearic acid to obtain total fatty acids; S2, mixing diglycerol, adipic acid, total fatty acids and organotin catalyst and starting to heat; S3, controlling the initial reaction temperature at 140-150℃, the reaction vacuum at 0.04MPa, controlling the heating rate during the reaction at 2-10℃ / h to raise the temperature to 190-210℃, then changing the reaction vacuum to 0.1MPa, and holding the reaction at this temperature for 4-10h; after the reaction is completed, taking a sample to determine the acid value; S4, after the acid value reaches the standard, turning on the vacuum pump unit, and holding the reaction at this temperature for 2-5h under high vacuum conditions to obtain the crude product of bis-diglycerol polyacryl adipate-2, and cooling and filtering the crude product of bis-diglycerol polyacryl adipate-2 to obtain bis-diglycerol polyacryl adipate-2. The above-mentioned technical method involves adding all raw materials and catalysts into the reactor at once, and slowly raising the temperature to 190-210℃ at an initial temperature of 140-150℃, using an organotin catalyst. This method has the following drawbacks: 1. The organotin catalyst used is expensive and difficult to separate and process after the reaction, resulting in catalyst residue. Trace amounts of residue can affect the safety of the product in cosmetic applications; 2. By adding the materials and catalyst into the reactor at once and raising the temperature simultaneously, the catalyst begins to act during the material preparation stage, making it difficult to control the first step of the reaction, resulting in difficulty in achieving the desired degree of esterification in the later stages and poor selectivity of the final product.

[0006] Therefore, there is an urgent need to develop a method for preparing bis-diglycerol polyacryl adipate-2 that features easy catalyst separation, high product purity, and a green and environmentally friendly process. Summary of the Invention

[0007] Therefore, this invention proposes a method for preparing high-purity bis-diglycerol polyacryl adipate-2.

[0008] The technical solution of this invention is implemented as follows: A method for preparing high-purity bis-diglycerol polyacryl adipate-2, the specific steps of which include: S1. Add diglyceride and mixed acid into the reactor, heat under vacuum to dissolve the material, remove water, mix well, and obtain the material. S2. Add a catalyst to the material to carry out the esterification reaction, and measure the acid value after the reaction is completed; S3. After the acid value meets the standard, the temperature is lowered under vacuum and filtered to obtain bis-diglycerol polyacryl adipate-2.

[0009] Furthermore, in step S1, the mixed acids are caprylic / capric acid, isostearic acid, stearic acid, and adipic acid in a molar ratio of 0.50-0.55:0.04-0.05:1.10-1.50:0.80-0.85.

[0010] Furthermore, the molar ratio of caprylic / capric acid, isostearic acid, stearic acid, adipic acid to diglycerides is 0.50-0.55:0.04-0.05:1.10-1.50:0.80-0.85:1.

[0011] Furthermore, in step S1, the vacuum degree of the vacuum heating is 5-20 Pa, the temperature is 80-120℃, and the time is 30-60 min; the water removal is carried out until the moisture content is less than 0.1%.

[0012] Furthermore, in step S2, the catalyst is at least one of zinc oxide or bismuth oxide, and the amount of catalyst added is 0.05-0.08% of the material mass.

[0013] Furthermore, in step S2, the initial reaction temperature of the esterification reaction is 140°C, which is then increased to 180°C, the vacuum degree is 5-20 Pa, and the time is 6-15 h.

[0014] Furthermore, in step S3, the acid value meeting the standard means that the acid value measured in S2 is less than 0.2 mg KOH / g.

[0015] Furthermore, in step S3, the vacuum cooling is carried out at a cooling rate of 5-20 Pa and 0.8-1 °C / min to room temperature; the filtration is carried out through a 0.1 μm microporous filter, and the catalyst residue is less than 5 ppm; the purity of the bis-diglycerol polyacryl adipate-2 is greater than 98%.

[0016] A high-purity bis-diglycerol polyacryladiopside-2 is prepared by any of the above preparation methods.

[0017] Application of a high-purity bis-diglyceride polyacryladiopate-2 in the preparation of cosmetics.

[0018] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention pre-processes all raw materials except the catalyst under vacuum heating to improve the mixing uniformity of the raw materials. It also pre-treats the raw materials under vacuum to remove water, ensuring low moisture content and promoting the forward reaction. The catalyst is added after the water removal pre-treatment for heat preservation reaction, avoiding the reaction from starting during the material processing. This allows for better control of the first step of the reaction, better product selectivity, fewer side reactions, high purity of the final product, and more controllable process flow.

[0019] 2. The catalyst of this invention uses zinc oxide or bismuth oxide, which is safer than the organotin catalysts of the prior art. The catalyst of this invention can be separated from the product by sieving, reducing catalyst residue, resulting in high product safety. The amount of catalyst used is small, which reduces the esterification reaction temperature, lowers the cost, and improves production efficiency.

[0020] 3. The mixed acid of the present invention is composed of caprylic / capric acid, isostearic acid, stearic acid, and adipic acid in a molar ratio of 0.50-0.55:0.04-0.05:1.10-1.50:0.80-0.85, with stearic acid and adipic acid as the dominant acids and isostearic acid as the minimum proportion. Products prepared from raw materials with specific proportions exhibit better hardness and film-forming properties. Verification has shown that the hardness and film-forming properties of the product of the present invention are highly correlated with the proportions of the various raw materials in the mixed acid. Detailed Implementation

[0021] To better understand the technical content of this invention, specific embodiments are provided below to further illustrate the invention.

[0022] Unless otherwise specified, the experimental methods used in the embodiments of this invention are all conventional methods.

[0023] Unless otherwise specified, all materials and reagents used in the embodiments of this invention are commercially available.

[0024] The acid value of the present invention is obtained according to the test method in GB / T 5009.229-2016.

[0025] Example 1 S1. Diglycerides, caprylic / capric acid, isostearic acid, stearic acid and adipic acid in a molar ratio of 1:0.53:0.04:1.25:0.83 are added into the reaction vessel in sequence. The mixture is heated to 100°C under vacuum of 10Pa and kept at 45min to turn the material into a liquid state. Water is removed until the moisture content is less than 0.1%. The mixture is stirred and mixed to obtain the material. S2. Add zinc oxide catalyst to the material. The amount of zinc oxide added is 0.07% of the total material. Stir and mix. The initial reaction temperature is 140℃. The temperature is increased to 180℃ at a heating rate of 2℃ / min. The vacuum degree is 10Pa. The temperature is maintained for 8 hours. After the reaction is completed, the acid value is measured to be 0.15mgKOH / g. S3. Under a vacuum of 10 Pa, the temperature was reduced to room temperature at a rate of 1 °C / min. After filtration through a 0.1 μm microporous filter, the residual zinc oxide catalyst was less than 5 ppm, yielding bis-diglycerol polyacryladiate-2 with a purity of 99.0%.

[0026] Example 2 S1. Diglycerides, caprylic / capric acid, isostearic acid, stearic acid and adipic acid in a molar ratio of 1:0.50:0.04:1.10:0.80 are added into the reaction vessel in sequence. The mixture is heated to 80°C under vacuum of 5 Pa and kept at 60 min to turn the material into a liquid state. Water is removed until the moisture content is less than 0.1%. The mixture is stirred and mixed to obtain the material. S2. Add bismuth oxide catalyst to the material. The amount of bismuth oxide added is 0.05% of the total material. Stir and mix. The initial reaction temperature is 140℃. The temperature is increased to 180℃ at a heating rate of 1℃ / min. The vacuum degree is 5Pa. The temperature is maintained for 15h. After the reaction is completed, the acid value is measured to be 0.20mgKOH / g. S3. Under a vacuum of 5 Pa, the temperature was reduced to room temperature at a rate of 1 °C / min. After filtration through a 0.1 μm microporous filter, the residual amount of bismuth oxide catalyst was less than 5 ppm, yielding bis-diglycerol polyacryladiate-2 with a purity of 98.8%.

[0027] Example 3 S1. Diglycerides, caprylic / capric acid, isostearic acid, stearic acid and adipic acid in a molar ratio of 1:0.55:0.05:1.50:0.85 are added into the reaction vessel in sequence. The mixture is heated to 120°C under vacuum of 20Pa and kept at that temperature for 30 minutes to turn the material into a liquid state. Water is removed until the moisture content is less than 0.1%. The mixture is stirred and mixed to obtain the final material. S2. Add zinc oxide catalyst to the material. The amount of zinc oxide added is 0.08% of the total material. Stir and mix. The initial reaction temperature is 140℃. The temperature is increased to 180℃ at a heating rate of 3℃ / min. The vacuum degree is 20Pa. The temperature is maintained for 6h. After the reaction is completed, the acid value is measured to be 0.17mgKOH / g. S3. Under a vacuum of 20 Pa, the mixture was cooled to room temperature at a rate of 1 °C / min and filtered through a 0.1 μm microporous filter. The residual amount of zinc oxide catalyst was less than 5 ppm, yielding bis-diglycerol polyacryladiate-2 with a purity of 98.9%.

[0028] Results: The products obtained in Examples 1-3 were pale yellow ointments with no or slight characteristic odor, good film-forming properties when applied to the skin, and were not easy to rinse off.

[0029] Comparative Example 1 The difference from Example 1 is that the heating procedure in step S2 is different.

[0030] S1. Diglycerides, caprylic / capric acid, isostearic acid, stearic acid and adipic acid in a molar ratio of 1:0.53:0.04:1.25:0.83 are added into the reactor in sequence. The mixture is heated to 100°C under vacuum at 10Pa and kept at 100°C for 45 minutes to turn the mixture into a liquid. Water is removed until the moisture content is less than 0.1%. The mixture is stirred and mixed to obtain the final material. S2. Add zinc oxide catalyst to the material, the amount of zinc oxide added is 0.07% of the total material, stir and mix, the initial reaction temperature is 140℃, the temperature is increased to 160℃ at a heating rate of 10℃ / min, the vacuum degree is 10Pa, and the temperature is held for 2h. Then the temperature is increased to 180℃ at a heating rate of 5℃ / h, the vacuum degree is 10Pa, and the temperature is held for 6h. After the reaction is completed, the acid value is measured to be 6.55mgKOH / g. S3. Under a vacuum of 10 Pa, the temperature was reduced to room temperature at a rate of 1 °C / min. After filtration through a 0.1 μm microporous filter, the residual zinc oxide catalyst was less than 5 ppm, yielding bis-diglycerol polyacryladiate-2 with a purity of 95.0%.

[0031] Results: The obtained product was a pale yellow paste with no or slight characteristic odor. It exhibited obvious stringiness when applied and the residue after rinsing with water was not as good as in Example 1.

[0032] Comparative Example 2 The difference from Example 1 is that the molar ratio of the raw materials is different.

[0033] S1. Diglycerides, caprylic / capric acid, isostearic acid, stearic acid and adipic acid in a molar ratio of 1:0.6:0.1:0.7:0.5 are added into the reaction vessel in sequence. The mixture is heated to 100°C under vacuum at 10Pa and kept at 100°C for 45 minutes to turn the material into a liquid state. Water is removed until the water content is less than 0.1%. The mixture is stirred and mixed to obtain the material. S2. Add zinc oxide catalyst to the material. The amount of zinc oxide added is 0.07% of the total material. Stir and mix. The initial reaction temperature is 140℃. The temperature is increased to 180℃ at a heating rate of 2℃ / min. The vacuum degree is 10Pa. The temperature is maintained for 8 hours. After the reaction is completed, the acid value is measured to be 4.96mgKOH / g. S3. Under a vacuum of 10 Pa, the temperature was reduced to room temperature at a rate of 1 °C / min. After filtration through a 0.1 μm microporous filter, the residual zinc oxide catalyst was less than 5 ppm, yielding bis-diglycerol polyacryladiate-2 with a purity of 96.5%.

[0034] Results: The obtained product was a pale yellow paste with no or a slight characteristic odor. The sampled product was too soft and lacked hardness. The residue after rinsing with water was not as good as in Implementation Example 1.

[0035] Comparative Example 3 The difference from Example 1 is that the molar ratio of the raw materials is different.

[0036] S1. Diglycerides, caprylic / capric acid, isostearic acid, stearic acid and adipic acid in a molar ratio of 1:2.3:0.80:2.60:0.83 are added into the reaction vessel in sequence. The mixture is heated to 100°C under vacuum of 10Pa and kept at 45min to turn the material into a liquid state. Water is removed until the water content is less than 0.1%. The mixture is stirred and mixed to obtain the material. S2. Add zinc oxide catalyst to the material. The amount of zinc oxide added is 0.07% of the total material. Stir and mix. The initial reaction temperature is 140℃. The temperature is increased to 180℃ at a heating rate of 2℃ / min. The vacuum degree is 10Pa. The temperature is maintained for 8 hours. After the reaction is completed, the acid value is measured to be 6.29mgKOH / g. S3. Under a vacuum of 10 Pa, the temperature was reduced to room temperature at a rate of 1 °C / min. After filtration through a 0.1 μm microporous filter, the residual amount of zinc oxide catalyst was less than 5 ppm, yielding bis-diglycerol polyacryladiate-2 with a purity of 96.0%.

[0037] Results: The obtained product was a pale yellow solid with a slight characteristic odor. The sample was too hard, but it had a smooth feel when applied to the skin and formed a good film.

[0038] Comparative Example 4 The difference from Example 1 is that the catalyst used is the organotin catalyst tetrabutyltin from CN120647533 A.

[0039] S1. Diglycerides, caprylic / capric acid, isostearic acid, stearic acid and adipic acid in a molar ratio of 1:0.53:0.04:1.25:0.83 are added into the reactor in sequence. The mixture is heated to 100°C under vacuum at 10Pa and kept at 100°C for 45 minutes to turn the mixture into a liquid. Water is removed until the moisture content is less than 0.1%. The mixture is stirred and mixed to obtain the final material. S2. Add tetrabutyltin catalyst to the material. The amount of tetrabutyltin added is 0.07% of the total material. Stir and mix. The initial reaction temperature is 140℃. The temperature is increased to 180℃ at a heating rate of 2℃ / min. The vacuum degree is 10Pa. The temperature is maintained for 8 hours. After the reaction is completed, the acid value is measured to be 11.25mgKOH / g. S3. Under a vacuum of 10 Pa, the temperature was reduced to room temperature at a rate of 1 °C / min. After filtration through a 0.1 μm microporous filter, the catalyst residue was greater than 50 ppm, yielding bis-diglycerol polyacryladiate-2 with a purity of 95.8%.

[0040] Results: The obtained product was a pale yellow paste with a slight characteristic odor, and the sample was too hard.

[0041] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing high-purity bis-diglycerol polyacryladiopside-2, characterized in that, The specific steps include: S1. Add diglyceride and mixed acid into the reactor, heat under vacuum to dissolve the material, remove water, mix well, and obtain the material. S2. Add a catalyst to the material to carry out the esterification reaction, and measure the acid value after the reaction is completed; S3. After the acid value meets the standard, the temperature is lowered under vacuum and filtered to obtain bis-diglycerol polyacryl adipate-2.

2. The method for preparing high-purity bis-diglycerol polyacryladiopside-2 as described in claim 1, characterized in that, In step S1, the mixed acids are caprylic / capric acid, isostearic acid, stearic acid and adipic acid in a molar ratio of 0.50-0.55:0.04-0.05:1.10-1.50:0.80-0.

85.

3. The method for preparing high-purity bis-diglycerol polyacryladiopside-2 as described in claim 2, characterized in that, The molar ratio of caprylic / capric acid, isostearic acid, stearic acid, adipic acid and diglycerides is 0.50-0.55:0.04-0.05:1.10-1.50:0.80-0.85:

1.

4. The method for preparing high-purity bis-diglycerol polyacryladiopside-2 as described in claim 1, characterized in that, In step S1, the vacuum degree of the vacuum heating is 5-20 Pa, the temperature is 80-120℃, and the time is 30-60 min; the water removal is carried out until the moisture content is less than 0.1%.

5. The method for preparing high-purity bis-diglycerol polyacryladiopside-2 as described in claim 1, characterized in that, In step S2, the catalyst is at least one of zinc oxide or bismuth oxide, and the amount of catalyst added is 0.05-0.08% of the material mass.

6. The method for preparing high-purity bis-diglycerol polyacryladiopside-2 as described in claim 1, characterized in that, In step S2, the initial reaction temperature of the esterification reaction is 140°C, which is then increased to 180°C, the vacuum degree is 5-20 Pa, and the time is 6-15 h.

7. The method for preparing high-purity bis-diglycerol polyacryladiopside-2 as described in claim 1, characterized in that, In step S3, the acid value meeting the standard means that the acid value measured in S2 is less than 0.2 mg KOH / g.

8. The method for preparing high-purity bis-diglycerol polyacryladiopside-2 as described in claim 1, characterized in that, In step S3, the vacuum cooling is carried out at a cooling rate of 0.8-1℃ / min to room temperature; the filtration is carried out through a 0.1μm microporous filter, and the catalyst residue is less than 5ppm; the purity of the bis-diglycerol polyacryl adipate-2 is greater than 98%.

9. A high-purity bis-diglycerol polyacryladiopside ester-2, characterized in that, It is prepared by the preparation method according to any one of claims 1-8.

10. The use of the high-purity bis-diglycerol polyacryl adipate-2 according to claim 9 in the preparation of cosmetics.