Process for the co-production of propylene glycol / dipropylene glycol / polyether 202 and process for the preparation of polyether

Abstract

The application relates to a method for co-producing propylene glycol / dipropylene glycol / polyether 202 and a polyether preparation method, wherein the method for co-producing propylene glycol / dipropylene glycol / polyether 202 comprises the following steps: mixing water and propylene oxide to carry out a hydration reaction to obtain a reaction liquid; the temperature of the hydration reaction is 160 DEG C-240 DEG C, the pressure is 10 MPa-25 MPa, and the molar ratio of water to propylene oxide is (0.08-0.6):1; the reaction liquid is subjected to rectification to obtain propylene glycol, dipropylene glycol and polyether 202 respectively. KOH or NaOH is not needed to be used as a catalyst, that is, neutralization and filtration steps are not needed to be carried out, waste water and filter residue generated due to the neutralization and filtration steps can be effectively avoided, and the risk that polyether 202 contains potassium ions, sodium ions or has an acid value exceeding a standard can be effectively avoided. The polyether 202 obtained by the method has a low acid value, low contents of potassium ions and sodium ions, and can be directly used as a starting agent for preparing polyether; and the obtained propylene glycol and dipropylene glycol have high purity.

Description

Technical Field

[0001] This application relates to the field of synthetic technology, and in particular to a method for co-producing propylene glycol / dipropylene glycol / polyether 202 and a method for preparing the polyether. Background Technology

[0002] Propylene glycol (PG) is an important raw material for unsaturated polyesters, epoxy resins, and polyurethane resins. Unsaturated polyesters are widely used in surface coatings and reinforced plastics. At the same time, due to its good viscosity and hygroscopicity and non-toxicity, propylene glycol is widely used as a humectant, antifreeze, lubricant, and solvent in the food, pharmaceutical, and cosmetic industries. Propylene glycol is also used as a humectant and mildew inhibitor in tobacco.

[0003] Dipropylene glycol can be used as a raw material for polyester resins, polyurethane resins, acrylates and cosmetics, as an oil-water miscible solvent, a solvent for printing inks and fragrances, and a wetting agent for cellophane.

[0004] Low molecular weight polyethers, such as polypropylene glycol with a molecular weight of 200-700, can be used as dispersants for pigments, antifoaming agents in coatings and hydraulic oils, refrigerants and coolants for heat transfer fluids, viscosity improvers, and additives for water-soluble cutting fluids, roller oils, and hydraulic oils, depending on their molecular weight. They can also be used as intermediates in esterification, etherification, and polycondensation reactions.

[0005] Polyurethane elastomers derived from polyether polyols possess excellent hydrolytic stability, weather resistance, low-temperature flexibility, and mildew resistance, making them widely used in automotive parts, cables, films, medical devices, rubber rollers, and oil-resistant seals. High-molecular-weight polyether polyols can be synthesized from low-molecular-weight polyethers, such as polyether 202. Traditional methods for preparing polyether 202 use propylene glycol as a starting agent and KOH or NaOH as a catalyst, undergoing a ring-opening polymerization reaction with propylene oxide, followed by neutralization, filtration, and distillation. However, this method typically generates large amounts of wastewater and filter residue during the neutralization and filtration steps, and also carries the risk of excessive potassium ion, sodium ion, or acid value levels.

[0006] Therefore, it is necessary to improve the traditional preparation method of polyether 202. Summary of the Invention

[0007] Based on this, this application provides a method for co-producing propylene glycol / dipropylene glycol / polyether 202 and a method for preparing polyether. The polyether 202 prepared by this method has a low acid value and low potassium and sodium ion content, and can be directly used as an initiator for preparing high molecular weight polyether.

[0008] The technical solution to the above-mentioned technical problems in this application is as follows.

[0009] The first aspect of this application provides a method for co-producing propylene glycol / dipropylene glycol / polyether 202, comprising the following steps:

[0010] Water and propylene oxide are mixed and subjected to a hydration reaction to obtain a reaction solution; the temperature of the hydration reaction is 160℃~240℃, the pressure is 10 MPa~25 MPa, and the molar ratio of water to propylene oxide is (0.08~0.6):1.

[0011] The reaction solution was distilled to obtain propylene glycol, dipropylene glycol and polyether 202, respectively.

[0012] In some embodiments, in the method for co-producing propylene glycol / dipropylene glycol / polyether 202, the hydration reaction is carried out at a temperature of 190°C to 220°C and a pressure of 19 MPa to 24 MPa.

[0013] In some embodiments, in the method for co-producing propylene glycol / dipropylene glycol / polyether 202, the molar ratio of water to propylene oxide is (0.1~0.4):1.

[0014] In some embodiments, the hydration reaction time in the method for co-producing propylene glycol / dipropylene glycol / polyether 202 is 8 h to 25 h.

[0015] In some embodiments, the distillation in the method for co-producing propylene glycol / dipropylene glycol / polyether 202 is a three-tower continuous distillation.

[0016] In some embodiments, in the method for co-producing propylene glycol / dipropylene glycol / polyether 202, the distillation equipment includes a No. 1 distillation column, a No. 2 distillation column, and a No. 3 distillation column, wherein propylene glycol is obtained at the top of the No. 2 distillation column, dipropylene glycol is obtained at the top of the No. 3 distillation column, and polyether 202 is obtained at the bottom of the No. 3 distillation column.

[0017] In some embodiments, the reactor for carrying out the hydration reaction in the method for co-producing propylene glycol / dipropylene glycol / polyether 202 includes at least one of a batch reactor, a tubular reactor, a fixed-bed reactor, a slurry-bed reactor, and a microchannel reactor.

[0018] The second aspect of this application provides a polyether 202, which is prepared using the method for co-producing propylene glycol / dipropylene glycol / polyether 202 provided in the first aspect of this application.

[0019] In some embodiments, the hydroxyl value of polyether 202 is 450 mgKOHg~540 mgKOHg.

[0020] A third aspect of this application provides a method for preparing a polyether, comprising the following steps:

[0021] Polyether 202 is prepared using the method for co-producing propylene glycol / dipropylene glycol / polyether 202 provided in the first aspect of this application;

[0022] The polyether 202, the bimetallic catalyst, and propylene oxide were mixed and then subjected to an etherification reaction at 110°C to 160°C to prepare the polyether.

[0023] In some embodiments, the bimetallic catalyst in the polyether preparation method includes at least one of a zinc-cobalt bimetallic catalyst and an iron-cobalt bimetallic catalyst.

[0024] Compared with the prior art, the method for co-producing propylene glycol / dipropylene glycol / polyether 202 in this application has the following beneficial effects:

[0025] The above-mentioned method for co-producing propylene glycol / dipropylene glycol / polyether 202 involves mixing water and propylene oxide for a hydration reaction, controlling the ratio of water to propylene oxide, as well as the temperature and pressure of the hydration reaction, to co-produce propylene glycol, dipropylene glycol, and polyether 202. The resulting polyether 202 has a low acid value and is free of potassium and sodium ions, making it suitable as a direct initiator for polyether preparation. Furthermore, the resulting propylene glycol and dipropylene glycol have high purity.

[0026] The above-mentioned method for co-producing propylene glycol / dipropylene glycol / polyether 202 does not require the use of KOH or NaOH as a catalyst, that is, it does not require neutralization and filtration steps, effectively avoiding wastewater and filter residue generated by neutralization and filtration steps, and effectively avoiding the risk of excessive potassium ions, sodium ions or acid value in polyether 202. Detailed Implementation

[0027] Reference will now be made to detailed embodiments of the present invention, one or more of which are described below. Each example is provided for explanation and not for limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made to the invention without departing from its scope or spirit. For example, features described or illustrated as part of one embodiment may be used in another embodiment to produce further embodiments.

[0028] Therefore, this invention is intended to cover such modifications and variations falling within the scope of the appended claims and their equivalents. Other objects, features, and aspects of the invention are disclosed in or will be apparent from the following detailed description. It will be understood by those skilled in the art that this discussion is merely a description of exemplary embodiments and is not intended to limit the broader aspects of the invention.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0030] The terms “comprising,” “including,” or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element preceded by the phrase “comprising one…” does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. The indefinite articles “a” and “an” preceding an element or component of the invention are not restrictive in terms of the number of elements or components (i.e., the number of times they appear). Therefore, “an” or “an” should be interpreted as including one or at least one, and singular elements or components also include plural forms, unless the quantity clearly refers only to the singular. “A plurality” means at least two, such as two, three, etc., unless otherwise expressly specified.

[0031] The weights of the relevant components mentioned in the embodiments of this invention can refer not only to the specific content of each component, but also to the proportional relationship between the weights of the components. Therefore, any scaling up or down of the content of the relevant components according to the embodiments of this invention is within the scope disclosed in the embodiments of this invention. Specifically, the weights mentioned in the embodiments of this invention can be well-known units of mass in the chemical industry, such as μg, mg, g, and kg.

[0032] Unless otherwise shown or indicated in the operational embodiments, all figures used to represent the amounts, physicochemical properties, etc., of ingredients in the specification and claims are to be understood to be adjusted by the term "about" in all cases. For example, therefore, unless stated to the contrary, the numerical parameters listed in the foregoing specification and appended claims are approximations, and those skilled in the art can appropriately modify these approximations to obtain the desired characteristics by utilizing the teachings disclosed herein. The use of numerical ranges indicated by endpoints includes all numbers within that range and any range within that range; for example, 1 to 5 includes 1, 1.1, 1.3, 1.5, 2, 2.75, 3, 3.80, 4, and 5, etc.

[0033] One embodiment of this application provides a method for co-producing propylene glycol / dipropylene glycol / polyether 202, comprising:

[0034] Step S10: Mix water and propylene oxide to carry out a hydration reaction to obtain a reaction solution; wherein the temperature of the hydration reaction is 160℃~240℃, the pressure is 10 MPa~25 MPa, and the molar ratio of water to propylene oxide is (0.08~0.6):1.

[0035] It is understood that the hydration reaction temperature includes, but is not limited to, 160℃, 170℃, 180℃, 190℃, 200℃, 210℃, 220℃, 230℃, and 240℃; the pressure includes, but is not limited to, 10 MPa, 11 MPa, 12 MPa, 13 MPa, 14 MPa, 15 MPa, 16 MPa, 17 MPa, 18 MPa, 19 MPa, 20 MPa, 21 MPa, 22 MPa, 23 MPa, 24 MPa, and 25 MPa; and the molar ratio of water to propylene oxide includes, but is not limited to, 0.08:1, 0.1:1, 0.15:1, 0.2:1, 0.25:1, 0.3:1, 0.35:1, 0.4:1, 0.45:1, 0.5:1, 0.55:1, and 0.6:1. In some examples, any two of these point values ​​can be used as endpoints within a range, and the same applies below.

[0036] In some of these examples, the temperature of the hydration reaction in step S10 is 160°C to 240°C.

[0037] Furthermore, the hydration reaction occurs at temperatures ranging from 190°C to 220°C.

[0038] In some of these examples, the pressure of the hydration reaction in step S10 is 10 MPa to 25 MPa.

[0039] Furthermore, the pressure for the hydration reaction is 19 MPa to 24 MPa.

[0040] In some of these examples, the hydration reaction time in step S10 is 8 h to 25 h.

[0041] The hydration reaction time includes, but is not limited to, 8 h, 10 h, 12 h, 14 h, 15 h, 16 h, 18 h, 20 h, 22 h, 24 h, and 25 h.

[0042] Furthermore, the hydration reaction takes 12 h to 22 h.

[0043] It is understandable that when the reactor carrying out the hydration reaction is a continuous reactor, the hydration reaction time can be referred to as "space time," which is short for "space-time," and its value is the ratio of the reaction volume to the feed volume flow rate.

[0044] In some of these examples, in step S10, the reactors in which the hydration reaction takes place include batch reactors and continuous reactors.

[0045] Furthermore, batch reactors include batch autoclave reactors.

[0046] Furthermore, the continuous reactor includes at least one of the following: tubular reactor, fixed-bed reactor, slurry-bed reactor, and microchannel reactor.

[0047] In some of these examples, in step S10, the propylene oxide can be added in an intermittent or continuous manner.

[0048] In some of these examples, in step S10, the molar ratio of water to propylene oxide is (0.08~0.6):1.

[0049] Furthermore, the molar ratio of water to propylene oxide is (0.1~0.4):1.

[0050] Step S20: The reaction solution is distilled to obtain propylene glycol, dipropylene glycol and polyether 202, respectively.

[0051] The above-mentioned method for co-producing propylene glycol / dipropylene glycol / polyether 202 involves mixing water and propylene oxide for a hydration reaction, controlling the ratio of water to propylene oxide, as well as the temperature and pressure of the hydration reaction. This method can co-produce propylene glycol, dipropylene glycol, and polyether 202. The resulting polyether 202 has a low acid value and is free of potassium and sodium ions, making it suitable as a direct initiator for preparing high molecular weight polyethers such as polyether 210. Furthermore, the resulting propylene glycol and dipropylene glycol have high purity.

[0052] The above-mentioned method for co-producing propylene glycol / dipropylene glycol / polyether 202 does not require the use of KOH or NaOH as a catalyst, that is, it does not require neutralization and filtration steps, effectively avoiding wastewater and filter residue generated by neutralization and filtration steps, and effectively avoiding the risk of excessive potassium ions, sodium ions or acid value in polyether 202.

[0053] The skill of the craftsman also attempted to lower the temperature of the hydration reaction, but failed to obtain polyether 202. He also attempted to further increase the molar ratio of water to propylene oxide, but the resulting polyether 202 had a high hydroxyl value and could not be used as a starting agent for the preparation of polyethers. He also attempted to lower the molar ratio of water to propylene oxide, but failed to obtain polyether 202.

[0054] In some of these examples, in step S20, the distillation is a three-tower continuous distillation.

[0055] It is understandable that a three-tower distillation column is used for continuous three-tower distillation.

[0056] In some of these examples, in step S20, the distillation apparatus includes distillation column 1, distillation column 2, and distillation column 3, with propylene glycol obtained at the top of distillation column 2, dipropylene glycol obtained at the top of distillation column 3, and polyether 202 obtained at the bottom of distillation column 3.

[0057] One embodiment of this application provides a polyether 202, which is prepared by the above-described method for co-producing propylene glycol / dipropylene glycol / polyether 202.

[0058] In some of these examples, the hydroxyl value of polyether 202 is 450 mgKOHg to 540 mgKOHg.

[0059] It is understandable that the higher the hydroxyl value of polyether 202, the smaller the molecular weight.

[0060] One embodiment of this application provides a method for preparing a polyether, including step S30:

[0061] Polyether 202 was prepared using the above method;

[0062] Polyether was prepared by mixing polyether 202, a bimetallic catalyst, propylene oxide, and the bimetallic catalyst and then carrying out an etherification reaction at 110℃~160℃.

[0063] The above-mentioned method for preparing polyethers, using polyether 202 as the initiator, results in high molecular weight polyethers with low acid values ​​and low potassium and sodium ion content.

[0064] It is understood that the polyethers prepared by the above-mentioned method can include, but are not limited to, polyether 210.

[0065] It is understood that in step S30, the temperature of the etherification reaction includes, but is not limited to, 110°C, 120°C, 130°C, 140°C, 150°C, and 160°C.

[0066] In some embodiments, in step S30, after mixing the mixture with propylene oxide, the mixture is first heated to 140°C~160°C for activation, and then cooled to 110°C~140°C for etherification reaction.

[0067] It is understandable that the activation phenomenon is a rapid rise in temperature and a rapid drop in pressure.

[0068] In some embodiments, in step S30, the reaction is stopped once there is no pressure drop in the reaction system.

[0069] Bimetallic catalysts are understood to refer to composite materials composed of two different metals, including but not limited to bimetallic catalysts dominated by noble metals, bimetallic catalysts dominated by transition metals, and bimetallic catalysts dominated by non-metals. Among them:

[0070] Bimetallic catalysts, primarily composed of precious metals, are typically composed of precious metals (such as platinum, palladium, and rhodium) and other metals (such as iron and vanadium). Due to the high catalytic activity of precious metals, these catalysts usually exhibit high catalytic activity and selectivity, making them suitable for applications in organic synthesis and chemical production.

[0071] Bimetallic catalysts, which are mainly composed of transition metals, are generally composed of transition metals (such as molybdenum, chromium, and manganese) and noble metals (such as palladium and platinum). Compared with catalysts containing only noble metals, these catalysts are less expensive and have the same high catalytic activity and selectivity. They are often used in chemical production and environmentally friendly preparation.

[0072] Bimetallic catalysts, which are predominantly nonmetallic, are generally composed of nonmetals (such as boron and phosphorus) and metals (such as rhodium and palladium). These catalysts can be used in reactions such as low-temperature hydrogenation and denitrification, as well as in fields such as organic synthesis.

[0073] In some embodiments, in step S30, the bimetallic catalyst includes at least one of a zinc-cobalt bimetallic catalyst and an iron-cobalt bimetallic catalyst.

[0074] In some embodiments, step S30 includes the following steps:

[0075] Step S31: The above polyether 202 and bimetallic catalyst are mixed and then dehydrated to obtain a mixture;

[0076] Step S32: Mix the mixture with propylene oxide and carry out an etherification reaction at 110℃~160℃ to prepare polyether.

[0077] In some embodiments, step S31, the dehydration process includes the following steps:

[0078] The mixture obtained by mixing polyether 202 and bimetallic catalyst was replaced with nitrogen and dehydrated at 95℃~120℃.

[0079] In some embodiments, in step S30, the mass percentage of water in the dehydrated mixture is <500 ppm.

[0080] One embodiment of this application provides a polyether prepared using the above-described method for preparing polyether.

[0081] In some of these embodiments, the polyether comprises polyether 210.

[0082] In some of these embodiments, the hydroxyl value of the polyether is 107 mgKOHg to 117 mgKOHg.

[0083] Furthermore, the hydroxyl value of the polyether is 110 mgKOHg~115 mgKOHg.

[0084] In some of these embodiments, the viscosity of the polyether is 150 mPa·s to 300 mPa·s.

[0085] Furthermore, the viscosity of the polyether is 150 mPa·s to 170 mPa·s.

[0086] In some of these embodiments, the polyether has a moisture content of ≤0.05% by mass.

[0087] Furthermore, the water content of the polyether is 0.01% to 0.05% by mass.

[0088] In some of these embodiments, the polyether has a pH of 6 to 7.

[0089] In some of these embodiments, the polyether has an acid value ≤0.05 mgKOH / g.

[0090] One embodiment of this application provides an elastomer article comprising the above-described polyether.

[0091] In some embodiments, the elastomer articles include, but are not limited to, automotive parts, cables, films, medical devices, rubber rolls, and oil-resistant seals.

[0092] The present application will be described in further detail below with reference to specific embodiments, but the embodiments of the present application are not limited thereto.

[0093] Example 1

[0094] Water and propylene oxide were mixed under pressure at a molar ratio of 0.4:1 and then fed into a tubular reactor. The reaction was carried out continuously at 200℃ and 15MPa for 9 h space time. The resulting reaction solution had the following composition by mass percentage: propylene oxide: propylene glycol: dipropylene glycol: tripropylene glycol: tetrapropylene glycol: pentapropylene glycol: hexapropylene glycol = 0.882: 27.781: 39.067: 19.656: 8.497: 2.996: 1.121. After continuous distillation in three columns, propylene glycol with a mass content greater than 99.9% was obtained at the top of the second column, dipropylene glycol with a mass content greater than 99.9% was obtained at the top of the third column, and polyether 202 with a hydroxyl value of 518 mgKOHg was obtained at the bottom of the third column. The overall yield was 98%.

[0095] Example 2

[0096] Water and propylene oxide were mixed under pressure at a molar ratio of 0.2:1 and then fed into a tubular reactor. The reaction was carried out continuously at 220℃ and 20MPa for 15 h space time. The resulting reaction solution had the following composition by mass percentage: propylene oxide: propylene glycol: dipropylene glycol: tripropylene glycol: tetrapropylene glycol: pentapropylene glycol: hexapropylene glycol = 0.148: 23.503: 31.28: 22.539: 13.479: 6.701: 2.35. After continuous distillation in three columns, propylene glycol with a mass content greater than 99.9%, dipropylene glycol with a mass content greater than 99.9%, and polyether 202 with a hydroxyl value of 496 mgKOHg were obtained, with an overall yield of 97.6%.

[0097] Example 3

[0098] Water and propylene oxide were added to a high-pressure autoclave reactor in a molar ratio of 0.3:1. After three nitrogen purgings, the mixture was heated and reacted at 180°C and 10 MPa until no pressure drop occurred. The resulting reaction solution had the following composition by mass percentage: propylene oxide: propylene glycol: dipropylene glycol: tripropylene glycol: tetrapropylene glycol: pentapropylene glycol: hexapropylene glycol = 0.46: 25.554: 34.696: 21.271: 11.19: 5.169: 1.66. Continuous distillation in three columns yielded propylene glycol with a mass content greater than 99.9%, dipropylene glycol with a mass content greater than 99.9%, and polyether 202 with a hydroxyl value of 505 mgKOHg, with an overall yield of 98.2%.

[0099] Example 4

[0100] Water and propylene oxide were mixed under pressure at a molar ratio of 0.4:1 and then injected into a tubular reactor. The reaction was carried out continuously at a temperature of 160℃ and a pressure of 25MPa for a space time of 9 h. The resulting reaction solution contained various components.

[0101] The composition by mass percentage is propylene oxide: propylene glycol: dipropylene glycol: tripropylene glycol: tetrapropylene glycol: pentapropylene glycol: hexapropylene glycol = 0.515: 26.984: 32.578: 18.797: 14.38: 4.146: 1.405. After continuous distillation in three columns, propylene glycol with a mass content greater than 99.9%, dipropylene glycol with a mass content greater than 99.9%, and polyether 202 with a hydroxyl value of 500 mg KOH / g were obtained, with an overall yield of 98%.

[0102] Example 5

[0103] Water and propylene oxide were mixed under pressure at a molar ratio of 0.6:1 and then fed into a tubular reactor. The reaction was carried out continuously at 200℃ and 15MPa for 9 h space time. The resulting reaction solution had the following composition by mass percentage: propylene oxide: propylene glycol: dipropylene glycol: tripropylene glycol: tetrapropylene glycol: pentapropylene glycol: hexapropylene glycol = 0.148: 23.503: 31.28: 22.539: 13.479: 6.701: 2.35. After continuous distillation in three columns, propylene glycol with a mass content greater than 99.9%, dipropylene glycol with a mass content greater than 99.9%, and polyether 202 with a hydroxyl value of 534 mgKOHg were obtained, with an overall yield of 98%.

[0104] Example 6

[0105] Water and propylene oxide were mixed under pressure at a molar ratio of 0.08:1 and then fed into a tubular reactor. The reaction was carried out continuously at 200℃ and 15 MPa for 9 h space time. The resulting reaction solution had the following composition and mass percentage: propylene oxide: propylene glycol: dipropylene glycol: tripropylene glycol: tetrapropylene glycol: pentapropylene glycol: hexapropylene glycol = 0.148: 23.503: 31.28: 22.539: 13.479: 6.701: 2.35. After continuous distillation in three columns, propylene glycol with a mass content greater than 99.9%, dipropylene glycol with a mass content greater than 99.9%, and polyether 202 with a hydroxyl value of 534 mgKOHg were obtained, with an overall yield of 98%.

[0106] Comparative Example 1

[0107] The Comparative Example 1 is essentially the same as Example 1, except that it was carried out continuously at a temperature of 220°C and a pressure of 1 MPa for a space time of 9 h, as detailed below:

[0108] Water and propylene oxide were mixed under pressure at a molar ratio of 0.4:1 and then pumped into a tubular reactor. The reaction was carried out continuously at a temperature of 220℃ and a pressure of 1MPa for a space time of 9 h. The mass content of propylene oxide in the resulting reaction solution was 99.76%, and the hydration reaction did not proceed.

[0109] Comparative Example 2

[0110] The Comparative Example 2 is essentially the same as Example 1, except that it was carried out continuously at a temperature of 140°C and a pressure of 20 MPa for a space time of 9 h, as detailed below:

[0111] Water and propylene oxide were mixed under pressure at a molar ratio of 0.4:1 and then fed into a tubular reactor. The reaction was carried out continuously at a temperature of 140℃ and a pressure of 20MPa for a space time of 9 h. The composition and mass percentage of the components in the resulting reaction solution were propylene oxide: propylene glycol: dipropylene glycol = 68.434: 30.011: 1.555. After continuous distillation in three columns, propylene glycol with a content greater than 99.9% and dipropylene glycol with a content greater than 99.9% could be obtained. Polyether 202 could not be obtained.

[0112] Comparative Example 3

[0113] It is basically the same as Example 1, except that in Comparative Example 3, the molar ratio of water to propylene oxide is 1:1.

[0114] Comparative Example 4

[0115] It is basically the same as Example 1, except that in Comparative Example 4, the molar ratio of water to propylene oxide is 0.01:1.

[0116] The main parameters of each embodiment and comparative example are shown in Table 1.

[0117] Table 1

[0118]

[0119] The performance of propylene glycol, dipropylene glycol, and Dow propylene glycol obtained in each embodiment was tested, wherein:

[0120] Stability test: Take 100g of sample, add 1g of 50% KOH aqueous solution, mix well, and store in an oven at 80 degrees Celsius to observe the color change.

[0121] Crystallinity test: Take 100g of sample and store it in a refrigerator below -25℃ to observe its crystallinity.

[0122] The test results for propylene glycol are shown in Table 2.

[0123] Table 2

[0124]

[0125] As shown in Table 2, the method for co-producing propylene glycol / dipropylene glycol / polyether 202 in this application yields propylene glycol with high purity, good stability, no impurities, and good product quality.

[0126] The test results for dipropylene glycol are shown in Table 3.

[0127] Table 3

[0128]

[0129] As shown in Table 3, the method for co-producing propylene glycol / dipropylene glycol / polyether 202 in this application yields dipropylene glycol with high purity, good stability, and an isomer distribution consistent with that of the Dow dipropylene glycol sample, indicating good product quality.

[0130] The polyether 202 prepared in each example and comparative example was used as an initiator for DMC method polyether (polyether 210) for experimental investigation. Taking the preparation of polyether 210 with polyether 202 with a hydroxyl value of 500 mgKOH / g as an example, the preparation steps are as follows:

[0131] 500 g of polyether 202 and 0.112 g (50 ppm) of zinc-cobalt bimetallic complex catalyst were added to the reactor. After nitrogen purging, the temperature was raised to 110℃ for dehydration for 1 h. Then, the temperature was raised to 120℃~140℃, and 86 g of propylene oxide was added for activation (the temperature rose rapidly and the pressure dropped rapidly). After activation, 1645 g of propylene oxide was added dropwise at a rate of 500 g / h. After the addition was completed, the mixture was matured until there was no pressure drop. The hydroxyl value was measured, and the product was degassed and discharged to obtain polyether.

[0132] Polyether 210 was successfully prepared using polyether 202 obtained in Examples 1-6 as the initiator, but no polyether 210 was detected using polyether 202 obtained in Comparative Example 3 as the initiator.

[0133] The polyether 210 prepared in Examples 1 to 6 were subjected to performance tests, and the required indicators were as follows:

[0134] Hydroxyl value 107 mgKOH / g~117 mgKOH / g, viscosity range 150 Pa·s~300 Pa·s, pH range 5.5~7.5, acid value ≤0.05 mgKOH / g, moisture <0.05%, potassium and sodium ≤2%.

[0135] The results are shown in Table 4. Examples 1 to 6 refer to polyether 210 prepared by using polyether 202 prepared by Examples 1 to 6 as the initiator. For example, Example 1 refers to polyether 210 prepared by using polyether 202 prepared by Example 1 as the initiator.

[0136] Table 4

[0137]

[0138] "0" means that the element was not detected.

[0139] As can be seen from the above, the method for co-producing propylene glycol / dipropylene glycol / polyether 202 in this application does not require neutralization and filtration steps, and the polyether 202 obtained by distillation can be directly used for the production of DMC process polyether.

[0140] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0141] The embodiments described above are merely illustrative of several implementation methods of this application, intended to facilitate a detailed understanding of the technical solutions of this application, but should not be construed as limiting the scope of protection of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the scope of protection of this application. It should be understood that technical solutions obtained by those skilled in the art based on the technical solutions provided in this application through logical analysis, reasoning, or limited experimentation are all within the scope of protection of the appended claims. Therefore, the scope of protection of this patent application should be determined by the content of the appended claims, and the specification can be used to interpret the content of the claims.

Claims

1. A method for co-producing propylene glycol / dipropylene glycol / polyether 202, characterized in that, Includes the following steps: Water and propylene oxide are mixed and subjected to a hydration reaction to obtain a reaction solution; the temperature of the hydration reaction is 160℃~240℃, the pressure is 10 MPa~25 MPa, and the molar ratio of water to propylene oxide is (0.08~0.6):

1. The reaction solution was distilled to obtain propylene glycol, dipropylene glycol and polyether 202, respectively, wherein the hydroxyl value of polyether 202 is 450 mgKOHg~540 mgKOHg.

2. The method as described in claim 1, characterized in that, The hydration reaction is carried out at a temperature of 190℃ to 220℃ and a pressure of 16 MPa to 21 MPa.

3. The method as described in claim 1, characterized in that, The molar ratio of water to propylene oxide is (0.1~0.4):

1.

4. The method as described in claim 1, characterized in that, The hydration reaction takes 8 h to 25 h.

5. The method according to any one of claims 1 to 4, characterized in that, The distillation is a three-tower continuous distillation.

6. The method as described in claim 5, characterized in that, The distillation equipment includes a No. 1 distillation column, a No. 2 distillation column, and a No. 3 distillation column. Propylene glycol is obtained at the top of the No. 2 distillation column, dipropylene glycol is obtained at the top of the No. 3 distillation column, and polyether 202 is obtained at the bottom of the No. 3 distillation column.

7. A method for preparing a polyether, characterized in that, Includes the following steps: Polyether 202 is prepared by the method according to any one of claims 1 to 6; The polyether 202, the bimetallic catalyst, and propylene oxide were mixed and then subjected to an etherification reaction at 110°C to 160°C to prepare the polyether.

8. The preparation method according to claim 7, characterized in that, The bimetallic catalyst includes at least one of a zinc-cobalt bimetallic catalyst and an iron-cobalt bimetallic catalyst.

9. The preparation method according to claim 7 or 8, characterized in that, The hydroxyl value of the polyether is 107 mgKOHg~117 mgKOHg.

Images