Polyethylene glycol monoricinoleate, its preparation method and application

Abstract

This invention belongs to the field of organic synthesis technology, specifically relating to a method for preparing polyethylene glycol monoricinoleate, particularly a low-color polyethylene glycol monoricinoleate, and further disclosing its preparation method and applications. The preparation method of polyethylene glycol monoricinoleate according to this invention is based on a traditional esterification reaction system, using polyethylene glycol and ricinoleic acid as raw materials, and employing organic or inorganic acids as catalysts to esterify and synthesize polyethylene glycol monoricinoleate. By adding an azeotropic agent and a siloxane modifier to the reaction system, the problems of dark color and poor performance in existing products are solved, especially as a coating additive to obtain coating products with a high dynamic color index.

Description

Technical Field

[0001] This invention belongs to the field of organic synthesis technology, specifically relating to a method for preparing polyethylene glycol monoricinoleate, particularly a low-color polyethylene glycol monoricinoleate, and further disclosing its preparation method and application. Background Technology

[0002] In recent years, with the improvement of people's living standards and the enhancement of environmental awareness, the development of new green surfactants with low toxicity and biodegradability using biomass such as natural plant oils as raw materials has become an industry trend. Polyethylene glycol monoricinoleate (PEG) is a nonionic surfactant that can be used to disperse pigments and pearlescent agents in the production processes of water-based coatings, printing inks, and thermoplastics. It promotes pigment deflocculation, and because the deflocculated pigment particles are small, it not only improves the gloss and color intensity of the coating, but also enhances the transparency of transparent pigments and the hiding power of opaque pigments. Currently, industrial paints containing PEG are mainly used in construction, automotive, canning, and leather industries.

[0003] Studies show that polyethylene glycol monoricinoleate (PEG) as a paint additive also has a significant impact on the final gloss effect of the paint surface. Currently, the intensity of the gloss effect is internationally expressed using the Dynamic Color Index (Dynamic Color Index), and the color number, purity, and acid value of PEG PEG itself all ultimately affect the Dynamic Color Index. However, the traditional synthesis process of PEG PEG mainly uses the direct esterification method, which employs catalysts such as sulfuric acid, p-toluenesulfonic acid, boric acid, and solid acids under high-temperature conditions for direct esterification. PEG PEG products prepared using this process are mostly amber or dark yellow, and their dark color often affects the final paint finish.

[0004] For example, Chinese patent CN102816324A reports a method for synthesizing polyethylene glycol monoricinoleate via a borate ester method. This involves reacting polyethylene glycol with boric acid to form a borate ester, then adding a PTS catalyst followed by esterification with ricinoleic acid. The resulting product is a pale yellow liquid. Another example is the literature "Research and Development of Synthetic Process for Low-Color Polyethylene Glycol 400 Dioleate," which reports the synthesis of polyethylene glycol dioleate using oleic acid and polyethylene glycol 400 under catalytic conditions, with antioxidant X as a protective agent. This process yields a product with a color intensity of 150 APHA. Therefore, the field anticipates the development of more low-color, high-performance polyethylene glycol monoricinoleate products, which is of positive significance for the preparation of coatings with high dynamic color indices. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to provide a method for preparing polyethylene glycol monoricinoleate, so as to solve the problems of dark color and poor performance of polyethylene glycol monoricinoleate products in the prior art;

[0006] The second technical problem to be solved by the present invention is to improve the polyethylene glycol monoricinoleate prepared by the above method and its application, wherein the polyethylene glycol monoricinoleate, as a coating additive, can produce coating products with high dynamic color index.

[0007] To solve the above-mentioned technical problems, the present invention provides a method for preparing polyethylene glycol monoricinoleate, comprising the steps of esterification synthesis using polyethylene glycol and ricinoleic acid as raw materials in the presence of an acidic catalyst, and adding an azeotropic agent and a siloxane modifier.

[0008] Specifically, in the preparation method of the polyethylene glycol monoricinoleate, the siloxane modifier includes one or a mixture of several of hexamethyldisiloxane, octamethyltrisiloxane, hexaethyldisiloxane, hexaphenyldisiloxane, methyloctadecylsiloxane or tetradecamethylhexasiloxane;

[0009] Preferably, the siloxane modifier includes hexaphenyldisiloxane and / or hexamethyldisiloxane.

[0010] Specifically, in the preparation method of the polyethylene glycol monoricinoleate, the amount of siloxane modifier added is 1-20 wt% of the mass of the ricinoleic acid;

[0011] Preferably, the amount of the siloxane modifier added is 5-10 wt% of the mass of the ricinoleic acid.

[0012] Specifically, in the preparation method of the polyethylene glycol monoricinoleate, the water azeotropic agent includes an organic solvent that can form an azeotrope with water;

[0013] Preferably, the water azeotropic agent includes one or more of the following solvents: n-hexane, cyclohexane, n-heptane, n-octane, toluene, benzene, xylene, or n-decane.

[0014] Preferably, the water azeotropic agent comprises n-heptane and / or n-octane.

[0015] Specifically, in the preparation method of the polyethylene glycol monoricinoleate, the molar ratio of polyethylene glycol to ricinoleic acid is 1.0-1.5:1.

[0016] Specifically, the method for preparing the polyethylene glycol monoricinoleate includes the polyethylene glycol comprising one or a mixture of several of polyethylene glycol-400, polyethylene glycol-600, polyethylene glycol-800, polyethylene glycol-1000, polyethylene glycol-2000, or polyethylene glycol-5000.

[0017] Preferably, the polyethylene glycol includes one or a mixture of several of polyethylene glycol-400, polyethylene glycol-600, or polyethylene glycol-800.

[0018] Specifically, in the preparation method of the polyethylene glycol monoricinoleate, the acidic catalyst includes at least one of an organic acid catalyst or an inorganic acid catalyst;

[0019] Preferably, the acidic catalyst comprises one or a mixture of several of sulfuric acid, acetic acid, p-toluenesulfonic acid, methanesulfonic acid, benzoic acid, or phenylacetic acid;

[0020] Preferably, the acidic catalyst comprises methanesulfonic acid and / or p-toluenesulfonic acid;

[0021] Preferably, the amount of acidic catalyst used is 0.1-2.0 wt% of the mass of ricinoleic acid. In the esterification process of the present invention, the amount of acidic catalyst has a certain impact on the color of polyethylene glycol monoricinoleate products. Generally, when the amount of acidic catalyst exceeds 5%, it will affect the color of the system, making it difficult to meet product requirements.

[0022] Specifically, the preparation method of the polyethylene glycol monoricinoleate is as follows:

[0023] The esterification reaction is carried out at a temperature of 100-200°C, preferably 120-160°C; and / or,

[0024] The esterification reaction takes 2-24 hours.

[0025] Specifically, the method for preparing the polyethylene glycol monoricinoleate further includes the steps of collecting the esterification reaction product and removing the azeotrope formed by the water azeotropic agent and water.

[0026] The present invention also discloses polyethylene glycol monoricinoleate prepared by the method.

[0027] The present invention also discloses the use of the polyethylene glycol monoricinoleate in the preparation of high dynamic color index coating products, and in particular in the preparation of coating additives.

[0028] The preparation method of polyethylene glycol monoricinoleate according to this invention is based on a traditional esterification reaction system. Using polyethylene glycol and ricinoleic acid as raw materials, and organic or inorganic acids as catalysts, esterification is carried out to synthesize polyethylene glycol monoricinoleate. By adding an azeotropic agent and a siloxane modifier to the reaction system, the problems of dark color and poor performance in existing products are solved, especially as a coating additive, to obtain coating products with a high dynamic color index.

[0029] The method for preparing polyethylene glycol monoricinoleate according to the present invention, based on the traditional esterification reaction, adds siloxanes as modifiers, especially siloxanes containing phenyl or alkyl groups. During the esterification synthesis process, the phenyl or alkyl groups contained in the siloxane can form coordination structures with Si atoms, that is, dπ-pπ bonds can be formed in Si-C, which reduces the electron cloud density of the system, lowers the energy of the system, inhibits the reaction of free radicals, and improves the thermal stability of the system. Moreover, the added siloxane can improve the thermal sensitivity of the system, ensuring that the undesirable components are controlled at extremely low levels even under prolonged heating, thus ensuring product quality.

[0030] The preparation method of polyethylene glycol monoricinoleate according to the present invention, based on the traditional esterification reaction, effectively removes the water produced in the esterification reaction by adding an azeotropic agent, especially an organic solvent that can form an azeotrope with water. This effectively ensures the stability of the entire esterification process. After the reaction, a simple removal of the azeotropic agent and the azeotrope of water can yield a low-color-number, high-quality polyethylene glycol monoricinoleate product, thus meeting the requirements of high-performance, low-color-number products. This effectively solves the problems of dark color and poor performance of existing products, especially as a coating additive, enabling the production of coating products with high dynamic color index. Detailed Implementation

[0031] The present invention will be further illustrated below with specific embodiments. These embodiments are merely illustrative and do not limit the scope of the invention.

[0032] In the following embodiments of the present invention, in order to improve the color and application performance of polyethylene glycol monoricinoleate products, a method for preparing polyethylene glycol monoricinoleate is provided, which includes the step of esterification synthesis using polyethylene glycol and ricinoleic acid as raw materials in the presence of an acidic catalyst, and adding an azeotropic agent and a siloxane modifier.

[0033] The preparation method of polyethylene glycol monoricinoleate according to the present invention, based on the traditional esterification reaction, effectively removes the water generated in the esterification reaction by adding a siloxane modifier and an azeotropic agent, thus ensuring the stability of the entire esterification process. After the reaction is completed, a simple removal of the azeotropic agent and the azeotrope of water yields a low-color-number, high-quality polyethylene glycol monoricinoleate product, which meets the requirements of high performance and low color number products. This effectively solves the problems of dark color and poor performance of existing products, especially as a coating additive, it can produce coating products with high dynamic color index.

[0034] As some possible implementation methods, the siloxane modifier includes one or a mixture of several of hexamethyldisiloxane, octamethyltrisiloxane, hexaethyldisiloxane, hexaphenyldisiloxane, methyloctadecylsiloxane or tetrademethylhexasiloxane;

[0035] Preferably, the siloxane modifier includes hexaphenyldisiloxane and / or hexamethyldisiloxane.

[0036] The method for preparing polyethylene glycol monoricinoleate according to the present invention, based on the traditional esterification reaction, adds siloxanes as modifiers, especially siloxanes containing phenyl or alkyl groups. During the esterification synthesis process, the phenyl or alkyl groups contained in the siloxane can form coordination structures with Si atoms, that is, dπ-pπ bonds can be formed in Si-C, which reduces the electron cloud density of the system, lowers the energy of the system, inhibits the reaction of free radicals, and improves the thermal stability of the system. Moreover, the added siloxane can improve the thermal sensitivity of the system, ensuring that the undesirable components are controlled at extremely low levels even under prolonged heating, thus ensuring product quality.

[0037] As one possible approach, the amount of the siloxane modifier added is 1-20 wt% of the mass of the ricinoleic acid;

[0038] Preferably, the amount of the siloxane modifier added is 5-10 wt% of the mass of the ricinoleic acid.

[0039] As some possible implementation methods, the water azeotropic agent includes one or more of the following solvents: n-hexane, cyclohexane, n-heptane, n-octane, toluene, benzene, xylene, or n-decane.

[0040] Preferably, the water azeotropic agent includes n-heptane and / or n-octane.

[0041] As one possible implementation, the molar ratio of the polyethylene glycol to the ricinoleic acid is 1.0-1.5:1.

[0042] As some possible implementation methods, the polyethylene glycol includes one or a mixture of several of polyethylene glycol-400, polyethylene glycol-600, polyethylene glycol-800, polyethylene glycol-1000, polyethylene glycol-2000 or polyethylene glycol-5000;

[0043] Preferably, the polyethylene glycol includes one or a mixture of several of polyethylene glycol-400, polyethylene glycol-600, or polyethylene glycol-800.

[0044] As some possible implementation methods, the acidic catalyst includes at least one of an organic acid catalyst or an inorganic acid catalyst;

[0045] Preferably, the acidic catalyst comprises one or a mixture of several of sulfuric acid, acetic acid, p-toluenesulfonic acid, methanesulfonic acid, benzoic acid, or phenylacetic acid;

[0046] Preferably, the acidic catalyst comprises methanesulfonic acid and / or p-toluenesulfonic acid.

[0047] As one possible implementation method, the amount of acidic catalyst used is 0.1-2.0 wt% of the mass of ricinoleic acid. In the esterification process of this invention, the amount of acidic catalyst has a certain impact on the color of polyethylene glycol monoricinoleate products. Generally, when the amount of acidic catalyst exceeds 5%, it will affect the color of the system, making it difficult to meet product requirements.

[0048] As some possible implementation methods, the esterification reaction is carried out at a temperature of 100-200°C, preferably 120-160°C;

[0049] As one possible approach, the esterification reaction can be carried out over a period of 2-24 hours.

[0050] As some possible implementations, the method also includes the steps of collecting the esterification reaction product and removing the azeotrope formed by the water azeotropic agent and water.

[0051] The present invention also discloses polyethylene glycol monoricinoleate prepared by the method.

[0052] The present invention also discloses the use of the polyethylene glycol monoricinoleate in the preparation of high dynamic color index coating products, and in particular in the preparation of coating additives.

[0053] In the following embodiments of the present invention, the monitoring and verification of the product throughout the esterification process is performed using colorimetric chromatography.

[0054] As an exemplary detection method, the gas chromatography parameters in the following embodiments of the present invention are as follows:

[0055] Gas chromatograph: Agilent 7820A;

[0056] Chromatographic column HP-5 (30m × 320μm × 0.25μm);

[0057] Inlet temperature: 150℃;

[0058] Flow split ratio 50:1;

[0059] Carrier gas flow rate: 1.5 ml / min;

[0060] Temperature program: Hold at 50℃ for 1 min, increase to 90℃ at 10℃ / min, hold for 0 min, then increase to 180℃ at 5℃ / min, hold for 0 min, then increase to 280℃ at 30℃ / min, hold for 6 min;

[0061] Detector temperature: 280℃.

[0062] Example 1

[0063] Equip a three-necked flask with a stirrer, water separator, and condenser, and connect it to a double-row tube for inert gas protection. Add 1 mol of ricinoleic acid, 1.1 mol of polyethylene glycol-600, 300.0 g of n-octane, 5 wt% of the mass of ricinoleic acid, and 3.0 g of p-toluenesulfonic acid (1.0 wt% of the mass of ricinoleic acid) to the three-necked flask and mix thoroughly.

[0064] Turn on the stirrer and control the oil bath heating to maintain the reaction temperature at around 140℃ for 8 hours. Stop heating when water is separated in the water separator after the reaction. Perform vacuum distillation on the collected reaction solution at 140℃ and 10 kPa to remove the azeotrope of n-octane and water, to obtain polyethylene glycol monoricinoleate.

[0065] In this embodiment, the reaction product was detected by gas chromatography, and its structure was found to be correct.

[0066] In this embodiment, the conversion rate and selectivity of the target product were measured respectively; wherein, the conversion rate refers to the percentage of molar amount of ricinoleic acid converted to the initial molar amount of ricinoleic acid; and the selectivity refers to the ratio of ricinoleic acid consumed in the formation of polyethylene glycol monoricinoleate to the total ricinoleic acid consumed.

[0067] In this embodiment, the conversion rate of the target product was measured to be 99.4%, and the selectivity of polyethylene glycol monoricinoleate was 95.3%.

[0068] Example 2

[0069] Equip a three-necked flask with a stirrer, water separator, and condenser, and connect it to a double-row tube for inert gas protection. Add ricinoleic acid (1 mol), polyethylene glycol-600 (1.05 mol), cyclohexane (300.0 g), hexaphenyldisiloxane (6.7 wt% of ricinoleic acid), and p-toluenesulfonic acid (0.7 wt% of ricinoleic acid) to the three-necked flask and mix thoroughly.

[0070] Turn on the stirrer and control the oil bath heating to maintain the reaction temperature at around 120℃ for 16 hours. Stop heating when water is separated in the water separator after the reaction. The collected reaction solution is then subjected to vacuum distillation at 120℃ and a vacuum degree of 5 kPa to remove the azeotrope of cyclohexane and water, yielding polyethylene glycol monoricinoleate.

[0071] In this embodiment, the reaction product was detected by gas chromatography, and its structure was found to be correct. The conversion rate of the target product was determined to be 99.6%, and the selectivity of polyethylene glycol monoricinoleate was 95.7%.

[0072] Example 3

[0073] Equip a three-necked flask with a stirrer, water separator, and condenser, and connect it to a double-row tube for inert gas protection. Add ricinoleic acid (1 mol), polyethylene glycol-400 (1 mol), cyclohexane (300.0 g), hexamethyldisiloxane (5 wt% of ricinoleic acid), and phenylacetic acid (0.5 wt% of ricinoleic acid) to the three-necked flask and mix thoroughly.

[0074] Turn on the stirrer and control the oil bath heating to maintain the reaction temperature at around 160℃ for 10 hours. Stop heating when water is separated in the water separator after the reaction. Perform vacuum distillation on the collected reaction solution at 140℃ and 10 kPa to remove the azeotrope of cyclohexane and water, to obtain polyethylene glycol monoricinoleate.

[0075] In this embodiment, the reaction product was detected by gas chromatography, and its structure was correct. The conversion rate of the target product was determined to be 95.3%, and the selectivity of polyethylene glycol monoricinoleate was 90.4%.

[0076] Example 4

[0077] Equip a three-necked flask with a stirrer, water separator, and condenser, and connect it to a double-row tube for inert gas protection. Add ricinoleic acid (1 mol), polyethylene glycol-800 (1.2 mol), n-heptane (300.0 g), octamethyltrisiloxane (10 wt% of ricinoleic acid), and sulfuric acid (1.0 wt% of ricinoleic acid) to the three-necked flask and mix thoroughly.

[0078] Turn on the stirrer and control the oil bath heating to maintain the reaction temperature at around 100℃ for 24 hours. Stop heating when water is separated in the water separator after the reaction. Perform vacuum distillation on the collected reaction solution at 140℃ and 10 kPa to remove the azeotrope of n-heptane and water, to obtain polyethylene glycol monoricinoleate.

[0079] In this embodiment, the reaction product was detected by gas chromatography, and its structure was found to be correct. The conversion rate of the target product was determined to be 99.7%, and the selectivity of polyethylene glycol monoricinoleate was 95.5%.

[0080] Example 5

[0081] Equip a three-necked flask with a stirrer, water separator, and condenser, and connect it to a double-row tube for inert gas protection. Add ricinoleic acid (1 mol), polyethylene glycol-1000 (1.5 mol), cyclohexane (300.0 g), hexaethyldisiloxane (1 wt% of the mass of ricinoleic acid), and methanesulfonic acid (0.1 wt% of the mass of ricinoleic acid) to the three-necked flask and mix thoroughly.

[0082] Turn on the stirrer and control the oil bath heating to maintain the reaction temperature at around 160℃ for 10 hours. Stop heating when water is separated in the water separator after the reaction. Perform vacuum distillation on the collected reaction solution at 140℃ and 10 kPa to remove the azeotrope of cyclohexane and water, to obtain polyethylene glycol monoricinoleate.

[0083] In this embodiment, the reaction product was detected by gas chromatography, and its structure was found to be correct. The conversion rate of the target product was determined to be 82.1%, and the selectivity of polyethylene glycol monoricinoleate was 91.6%.

[0084] Example 6

[0085] Equip a three-necked flask with a stirrer, water separator, and condenser, and connect it to a double-row tube for inert gas protection. Add ricinoleic acid (1 mol), polyethylene glycol-2000 (1.3 mol), xylene (300.0 g), tetradecyl hexasiloxane (20 wt% of ricinoleic acid), and acetic acid (2.0 wt% of ricinoleic acid) to the three-necked flask and mix thoroughly.

[0086] Turn on the stirrer and control the oil bath heating to maintain the reaction temperature at around 200℃ for 2 hours. Stop heating when water is separated in the water separator after the reaction. Perform vacuum distillation on the collected reaction solution at 140℃ and 10 kPa to remove the azeotrope of xylene and water, to obtain polyethylene glycol monoricinoleate.

[0087] In this embodiment, the reaction product was detected by gas chromatography, and its structure was found to be correct. The conversion rate of the target product was determined to be 86.2%, and the selectivity of polyethylene glycol monoricinoleate was 87.2%.

[0088] Example 7

[0089] Equip a three-necked flask with a stirrer, water separator, and condenser, and connect it to a double-row tube for inert gas protection. Add ricinoleic acid (1 mol), polyethylene glycol-5000 (1.1 mol), toluene (300.0 g), methyloctadecylsiloxane (8 wt% of ricinoleic acid), and p-toluenesulfonic acid (1.0 wt% of ricinoleic acid) to the three-necked flask and mix thoroughly.

[0090] Turn on the stirrer and control the oil bath heating to maintain the reaction temperature at around 140℃ for 10 hours. Stop heating when water is separated in the water separator after the reaction. Perform vacuum distillation on the collected reaction solution at 140℃ and 10 kPa to remove the azeotrope of toluene and water, to obtain polyethylene glycol monoricinoleate.

[0091] In this embodiment, the reaction product was detected by gas chromatography, and its structure was found to be correct. The conversion rate of the target product was determined to be 88.9%, and the selectivity of polyethylene glycol monoricinoleate was 89.1%.

[0092] Comparative Example 1

[0093] The preparation method of polyethylene glycol monoricinoleate in this comparative example is the same as that in Example 1, except that the hexaphenyldisiloxane is not added. Gas chromatography was used to detect the reaction product, and the structure was correct. The conversion rate of the target product was determined to be 98.1%, and the selectivity of polyethylene glycol monoricinoleate was 82.1%.

[0094] Comparative Example 2

[0095] The preparation method of polyethylene glycol monoricinoleate in this comparative example is the same as that in Example 1, except that the water azeotropic agent is not added. Gas chromatography was used to detect the reaction product, and the structure was correct. The conversion rate of the target product was determined to be 51.2%, and the selectivity of polyethylene glycol monoricinoleate was 92.6%.

[0096] Comparative Example 3

[0097] The preparation method of polyethylene glycol monoricinoleate in this comparative example is the same as that in Example 1, except that an equal amount of polymethylhydrosiloxane is added instead of hexaphenyldisiloxane. Gas chromatography was used to detect the reaction product, and the structure was correct. The conversion rate of the target product was determined to be 98.7%, and the selectivity of polyethylene glycol monoricinoleate was 82.5%.

[0098] Comparative Example 4

[0099] The preparation method of polyethylene glycol monoricinoleate in this comparative example is the same as that in Example 1, except that an equal amount of hexachlorodisiloxane is added instead of hexaphenyldisiloxane. Gas chromatography was used to detect the reaction product, and the structure was correct. The conversion rate of the target product was determined to be 98.2%, and the selectivity of polyethylene glycol monoricinoleate was 81.7%.

[0100] Comparative Example 5

[0101] The preparation method of polyethylene glycol monoricinoleate in this comparative example is the same as that in Example 1, except that an equal amount of heptamethylcyclotetrasiloxane is added instead of hexaphenyldisiloxane. Gas chromatography was used to detect the reaction product, and the structure was correct. The conversion rate of the target product was determined to be 99.4%, and the selectivity of polyethylene glycol monoricinoleate was 95.3%.

[0102] Comparative Example 6

[0103] The preparation method of polyethylene glycol monoricinoleate in this comparative example is the same as that in Example 1, except that an equal amount of tert-butylhydroquinone antioxidant is added instead of hexaphenyldisiloxane. Gas chromatography was used to detect the reaction product, and the structure was correct. The conversion rate of the target product was determined to be 98.6%, and the selectivity of polyethylene glycol monoricinoleate was 80.3%.

[0104] Experimental Example

[0105] 1. Physical and chemical parameter testing

[0106] The polyethylene glycol monoricinoleate prepared in Examples 1-7 and Comparative Examples 1-6 were subjected to physicochemical tests. The test indicators and methods are as follows:

[0107] Color number testing: APHA platinum-cobalt colorimetric method was used.

[0108] The physicochemical properties of the polyethylene glycol monoricinoleate products prepared in the above embodiments and comparative examples are shown in Table 1 below.

[0109] Table 1. Physicochemical properties of polyethylene glycol monoricinoleate

[0110] serial number Color number Example 1 18Hazen Example 2 25 Hazen Example 3 52Hazen Example 4 45 Hazen Example 5 56Hazen Example 6 61Hazen Example 7 58Hazen Comparative Example 1 92Hazen Comparative Example 2 87Hazen Comparative Example 3 76Hazen Comparative Example 4 112Hazen Comparative Example 5 83Hazen Comparative Example 6 61Hazen

[0111] As can be seen, the preparation method of polyethylene glycol monoricinoleate described in this application, by adding siloxane as a modifier, can obtain high-quality polyethylene glycol monoricinoleate with low color number under a catalytic system.

[0112] 2. Application performance

[0113] In this experimental example, polyethylene glycol monoricinoleate prepared in Examples 1-7 and Comparative Examples 1-6 were used as coating additives for paint preparation and coating. The specific paint preparation and coating process methods are referred to the methods provided in the paper "Preparation and Performance Study of Waterborne Metallic Coatings for Automobiles".

[0114] In this experimental example, the performance of coating products prepared using polyethylene glycol monoricinoleate as a coating additive was determined. The test indicators and test methods are as follows:

[0115] Dynamic Color Index: The SGY-A strobe index meter measures color using three internationally recognized angles: 15°, 45°, and 110°. Calculation formula: FI = [2.69(L* 15 -L* 110 ) 1.11 / (L* 45 ) 0.86 ].

[0116] The performance results of the coating products prepared from the polyethylene glycol monoricinoleate products in the above embodiments and comparative examples are shown in Table 2 below.

[0117] Table 2 Performance index results of coatings prepared from polyethylene glycol monoricinoleate

[0118] serial number Dynamic Color Index Example 1 26.3 Example 2 25.6 Example 3 24.8 Example 4 25.2 Example 5 24.2 Example 6 23.7 Example 7 24.1 Comparative Example 1 19.7 Comparative Example 2 21 Comparative Example 3 21.9 Comparative Example 4 18.8 Comparative Example 5 21.2 Comparative Example 6 21.6

[0119] Therefore, the polyethylene glycol monoricinoleate described in this application can be used as a coating additive to prepare high-quality polyethylene glycol monoricinoleate coating products with high dynamic color index.

[0120] In summary, the preparation method of polyethylene glycol monoricinoleate described in this invention is based on a traditional esterification reaction system. By adding an azeotropic agent and a modifier to the reaction system, it solves the problems of dark color and poor performance of existing products. In particular, as a coating additive, it can produce coating products with a high dynamic color index.

[0121] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A process for the preparation of polyethylene glycol monoricinoleate, characterized in that, The step of esterification synthesis including polyethylene glycol and ricinoleic acid as raw materials, and adding water azeotrope and siloxane modifier in the presence of an acidic catalyst; The siloxane modifier includes one or a mixture of several of hexamethyldisiloxane, octamethyltrisiloxane, hexaethyldisiloxane, hexaphenyldisiloxane or tetradecamethylhexasiloxane; The siloxane modifier is added in an amount of 1-20wt% of the mass of the ricinoleic acid.

2. The process for the preparation of polyethylene glycol mono ricinoleate according to claim 1, characterized in that, The siloxane modifier includes hexaphenyldisiloxane and / or hexamethyldisiloxane.

3. The process for the preparation of polyethylene glycol mono ricinoleate according to claim 1 or 2, characterized in that, The siloxane modifier is added in an amount of 5-10wt% of the mass of the ricinoleic acid.

4. The process for the preparation of polyethylene glycol mono ricinoleate according to claim 1, characterized in that, The water azeotrope includes an organic solvent that can form an azeotrope with water.

5. The process for the preparation of polyethylene glycol mono ricinoleate according to claim 4, characterized in that, The water azeotrope includes one or a mixture of several of n-hexane, cyclohexane, n-heptane, n-octane, toluene, benzene, xylene or n-decane.

6. The process for the preparation of polyethylene glycol mono ricinoleate according to claim 5, characterized in that, The water azeotrope includes n-heptane and / or n-octane.

7. The process for the preparation of polyethylene glycol mono ricinoleate according to claim 1, characterized in that, The molar ratio of the polyethylene glycol to the ricinoleic acid is 1.0-1.5:

1.

8. The process for the preparation of polyethylene glycol mono ricinoleate according to claim 1, characterized in that, The polyethylene glycol includes one or a mixture of several of polyethylene glycol-400, polyethylene glycol-600, polyethylene glycol-800, polyethylene glycol-1000, polyethylene glycol-2000 or polyethylene glycol-5000.

9. The process for the preparation of polyethylene glycol mono ricinoleate according to claim 8, characterized in that, The polyethylene glycol includes one or a mixture of several of polyethylene glycol-400, polyethylene glycol-600 or polyethylene glycol-800.

10. The process for the preparation of polyethylene glycol mono ricinoleate according to claim 1, characterized in that, The acidic catalyst includes at least one of an organic acid catalyst or an inorganic acid catalyst.

11. The process for the preparation of polyethylene glycol mono ricinoleate according to claim 10, characterized in that, The acidic catalyst includes one or a mixture of several of sulfuric acid, acetic acid, p-toluenesulfonic acid, methanesulfonic acid, benzoic acid or phenylacetic acid.

12. The process for the preparation of polyethylene glycol mono ricinoleate according to claim 11, characterized in that, The acidic catalyst includes methanesulfonic acid and / or p-toluenesulfonic acid.

13. The process for the preparation of polyethylene glycol mono ricinoleate according to claim 1, characterized in that, The acidic catalyst is used in an amount of 0.1-2.0wt% of the mass of the ricinoleic acid.

14. The method for preparing polyethylene glycol monoricinoleate according to claim 1, wherein: The temperature of the esterification reaction is 100-200℃; and / or, The reaction time of the esterification reaction is 2-24h.

15. The process for the preparation of polyethylene glycol mono ricinoleate according to claim 14, characterized in that: The temperature of the esterification reaction is 120-160℃.

16. The process for the preparation of polyethylene glycol mono ricinoleate according to claim 1, characterized in that, The method further includes the steps of collecting the esterification reaction product and removing the azeotrope formed by the water azeotrope and water.

17. Polyethylene glycol monoricinoleate prepared by the method of any one of claims 1-16.

18. Use of the polyethylene glycol monoricinoleate of claim 17 for preparing a high dynamic color index coating product.