Method for preparing polyether polyol by using double metal cyanide catalyst and application thereof

Abstract

The invention relates to the technical field of polyether polyol preparation, in particular to a method for preparing polyether polyol by using a double-metal cyanide catalyst and application of the polyether polyol. According to the method for preparing the polyether polyol by using the double-metal cyanide catalyst, ethylene oxide and other epoxy compounds are firstly introduced to initiate a reaction, then feeding is performed in multiple stages, and P2-P1, Px-Py and Pn are controlled to be within a certain range, so that regulation and control of product distribution are realized, high molecular weight trailing is reduced, and the viscosity of the product is reduced; the random poly (alkylene oxide-co-ethylene oxide) polyether polyol which is clear and transparent in appearance, good in fluidity at low temperature, uniform in molecular weight distribution and low in viscosity is prepared, and when the random poly (alkylene oxide-co-ethylene oxide) polyether polyol is used for preparing flatulence slow-rebound polyurethane foam, better stability can be achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of polyether polyol preparation, in particular to a method for preparing polyether polyol using a double metal cyanide catalyst and application thereof. BACKGROUND

[0002] Slow-rebound polyurethane foam, also known as viscoelastic foam, is also known as memory foam or energy-absorbing foam due to its special memory function of automatically restoring to the original shape after being subjected to an applied external force. Unlike ordinary soft polyurethane foam, slow-rebound polyurethane foam can quickly recover due to its elasticity after being subjected to an external force. When the slow-rebound foam is deformed by an external force, the recovery time can reach 3-15 seconds, and the recovery time can be adjusted according to the actual use. Since the slow-rebound polyurethane foam has good shape memory performance, energy absorption, sound absorption, shock absorption and other functions, it is often used as an impact absorber, sound absorber and shock absorber, and is widely used in high-end furniture, private bed mattresses, automobile parts, medical devices and other fields. When slow-rebound foam material is used in bedding and furniture such as sofas, the pressure distribution on the human body is more uniform, which can greatly reduce fatigue and displacement of the bottom surface.

[0003] Polyether polyols are generally used to manufacture polyurethane foams, including slow-rebound polyurethane foams. Polyether polyols (also known as polyoxyalkylene polyols) are basic chemical raw materials generated by reacting a starting material containing multiple active hydrogens with one or more alkylene oxides. In the production of slow-rebound polyurethane foam, the polyether polyols used are usually prepared by polymerizing a high-ethylene oxide (EO) content propylene oxide (PO) and ethylene oxide mixed monomer with a specific hydroxyl functionality starting compound using a strong base such as potassium hydroxide as a catalyst. The use of double metal cyanide (DMC) catalyst in this polymerization reaction can significantly reduce the content of monofunctional impurities in the polyether, and since the amount used is very small, the residual part does not need to be removed additionally, which can effectively reduce the production cost.

[0004] However, the application of DMC catalyst has key limitations. In the copolymerization of EO and PO, when the EO content in the system is high (especially when the EO accounts for more than 50% of the total monomer amount), the catalytic efficiency of the DMC catalyst decreases significantly, which is manifested as: the polymerization reaction rate is unstable, and local overheating or reaction stagnation easily occurs; the monomer conversion rate decreases, and the residual amount of unreacted EO increases, making it difficult to control the structure of the copolymer, the molecular weight distribution is uneven, the viscosity increases at low temperature, and the stability of the slow-rebound polyurethane foam is poor. SUMMARY

[0005] Therefore, the present application aims to solve the technical problem of overcoming the low polymerization efficiency in the prior art method for preparing polyether polyols using a double metal cyanide catalyst, which leads to the defects of high viscosity at low temperature and uneven molecular weight distribution of the prepared polyether polyols, thereby providing a method for preparing polyether polyols using a double metal cyanide catalyst and its application.

[0006] To this end, the present application provides the following technical solutions:

[0007] A method for preparing polyether polyols using a double metal cyanide catalyst, comprising the following steps:

[0008] S1 step: adding polyol, double metal cyanide catalyst and protonic acid into a closed reactor;

[0009] S2 step: heating the closed reactor to a reaction temperature, and introducing ethylene oxide and other epoxy compounds to initiate the reaction;

[0010] S3 step: after the initiation reaction is completed, a mixture of ethylene oxide and other epoxy compounds is added to the closed reactor in multiple stages for polymerization reaction, wherein the minimum value of the reaction pressure of each stage is P1, the maximum value of the reaction pressure of each stage is P2, P1 and P2 are both in MPa, wherein P1 and P2 of each stage satisfy 0

[0011] The pressure in the closed reactor at the end of each stage is Py, and nitrogen is charged to increase the pressure in the closed reactor to Px after the feeding of each stage is completed, except for the last stage, Py and Px are both in MPa, wherein Px and Py satisfy 0

[0012] S4 step: after the reaction is completed, aging and degassing to obtain polyether polyols.

[0013] Further, in the S3 step, the temperature of the polymerization reaction is 80-135℃.

[0014] Further, P1 and P2 satisfy 0

[0015] Further, P1 satisfies -0.1≤P1≤0.8MPa.

[0016] Further, P2 satisfies -0.01≤P2

[0017] Further, Px satisfies 0≤Px≤0.8MPa.

[0018] Furthermore, the Py satisfies -0.05≤Py≤0.9MPa.

[0019] Furthermore, the multi-stage operation is divided into 2-5 stages, with the mass of ethylene oxide and other epoxides added in each stage accounting for 20-50% of the total mass of ethylene oxide and other epoxides added in step S3.

[0020] Furthermore, in step S2 or S3, the weight ratio of the other epoxy compound to ethylene oxide is 95:5 to 5:95, preferably 60:40 to 5:95, and more preferably 25:75.

[0021] Furthermore, the other epoxy compound is selected from at least one of propylene oxide, 1,2-epoxybutane, 2,3-epoxybutane, tetrahydrofuran, and 1,2-epoxypentane, preferably propylene oxide.

[0022] Furthermore, in step S1, the polyol is a polyether polyol.

[0023] In some alternative embodiments, the polyether polyol has a functionality of 1-8 and a hydroxyl equivalent of >100 g / mol.

[0024] In some alternative embodiments, the polyether polyol is selected from at least one of glycerol polyoxyethylene polyoxypropylene ether, propylene glycol polyoxyethylene polyoxypropylene ether, and diglycerol polyoxyethylene polyoxypropylene ether.

[0025] Furthermore, the amount of the bimetallic cyanide catalyst added is 5-100 ppm based on the total mass of the polyol and the ethylene oxide and other epoxides added in steps S2 and S3.

[0026] Furthermore, the protic acid is selected from at least one of nitric acid, phosphoric acid, and sulfuric acid.

[0027] Furthermore, the mass of the protic acid accounts for 40-200 ppm of the mass of the polyol.

[0028] Furthermore, after the S2 step is heated, a step of introducing a protective gas for dehydration is also included.

[0029] In some alternative embodiments, the temperature of the heating and dehydration treatment is 50–160°C.

[0030] In some alternative embodiments, the protective gas is selected from at least one of nitrogen, carbon dioxide, helium, and argon.

[0031] Furthermore, in step S4, the degassing temperature is 50–165°C, the pressure is -0.085–-0.095 MPa, and the time is 15–120 min.

[0032] Furthermore, in step S2, the temperature at which the reaction is initiated is 120-155°C.

[0033] Furthermore, the total mass of ethylene oxide and other epoxides added in step S2 accounts for 10-50% of the mass of the polyol.

[0034] The present invention also provides a polyether polyol prepared by the above-described method for preparing polyether polyols using a bimetallic cyanide catalyst.

[0035] Furthermore, the hydroxyl equivalent of the polyether polyol is 1300–3000 g / mol.

[0036] Furthermore, the primary hydroxyl groups of the polyether polyol account for 50% to 90% of the molar percentage of all hydroxyl groups in the polyether polyol.

[0037] The present invention also provides an inflatable slow-rebound polyurethane foam, wherein, by weight, the raw materials include 60-80 parts of the above-mentioned polyether polyol, 50-70 parts of isocyanate and / or modified isocyanate, 2-5 parts of foaming agent, 10-30 parts by weight of chain extender, 5-15 parts by weight of grafted polyether, 0.01-0.5 parts by weight of catalyst, 0.3-2 parts by weight of foam stabilizer, and 2-5 parts by weight of cell opener.

[0038] The present invention also provides a method for preparing the above-mentioned inflatable slow-rebound polyurethane foam, comprising the following steps: mixing polyether polyol, foaming agent, chain extender, grafted polyether, catalyst, foam stabilizer, and cell opener, and then reacting them with isocyanate and / or modified isocyanate to obtain inflatable slow-rebound polyurethane foam.

[0039] In some alternative embodiments, the ambient temperature of the reaction is 20-30°C.

[0040] In some alternative embodiments, the reaction temperature is 22-24°C.

[0041] The technical solution of this invention has the following advantages:

[0042] 1. This invention provides a method for preparing polyether polyols using a bimetallic cyanide catalyst, comprising the following steps: S1 step: adding polyol, bimetallic cyanide catalyst, and protic acid to a closed reactor; S2 step: heating the closed reactor to the reaction temperature, and introducing ethylene oxide and other epoxides to initiate the reaction; S3 step: after the initiation reaction is complete, adding a mixture of ethylene oxide and other epoxides to the closed reactor in multiple stages to carry out a polymerization reaction, wherein the minimum reaction pressure of each stage is P1, and the maximum reaction pressure of each stage is P2, P... 1. The unit of P2 is MPa. In each stage, P1 and P2 satisfy 0 < P2 - P1 < 0.2 MPa. The pressure in the closed reactor after each stage of feeding is Py. Except for the last stage, nitrogen is introduced after each stage of feeding to increase the pressure in the closed reactor to Px. The units of Py and Px are MPa. In each stage, Px and Py satisfy 0 < Px - Py ≤ 0.1 MPa. The pressure in the closed reactor after the final reaction is Pn, 0 < Pn ≤ 1 MPa. Step S4: After the reaction is completed, the product is matured and degassed to obtain polyether polyol. This invention achieves product distribution regulation by first introducing ethylene oxide and other epoxy compounds to initiate the reaction, then feeding the product in multiple stages and controlling P2-P1, Px-Py, and Pn within specific ranges. This reduces high molecular weight tailing and lowers product viscosity, resulting in a random poly(epoxyalkane-co-ethylene oxide) polyether polyol with a clear and transparent appearance, good low-temperature flowability, uniform molecular weight distribution, and low viscosity.

[0043] 2. The slow-rebound polyurethane foam provided by this invention comprises 60-80 parts of polyether polyol prepared by the method of preparing polyether polyol using the bimetallic cyanide catalyst of this invention, 50-70 parts of isocyanate or modified isocyanate, 2-5 parts of blowing agent, 10-30 parts by weight of chain extender, 5-15 parts by weight of grafted polyether, 0.01-0.5 parts by weight of catalyst, 0.3-2 parts by weight of foam stabilizer, and 2-5 parts by weight of cell opener. The polyether polyol prepared by the method of preparing polyether polyol using the bimetallic cyanide catalyst of this invention, when mixed with the blowing agent, chain extender, grafted polyether, catalyst, foam stabilizer, and cell opener, and then used in combination with isocyanate and / or modified isocyanate in a specific ratio, can significantly improve the stability of the slow-rebound polyurethane foam. Foaming tests on the prepared slow-rebound polyurethane foam showed that the foam did not shrink, collapse, or sink. Detailed Implementation

[0044] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0045] For experiments not specifically described in the examples, the procedures or conditions should be followed according to the conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.

[0046] The raw materials used in the embodiments and comparative examples of this invention are as follows:

[0047] Glycerol polyoxyethylene polyoxypropylene ether (Mn=600, hydroxyl equivalent: 200g / mol, EO:PO mass ratio=75:25): purchased from Shanghai Fujia Fine Chemical Co., Ltd., product number: VE285.

[0048] DMC catalyst: purchased from Jiangsu Bade Polyurethane Co., Ltd., product number: DMC.

[0049] Grafted polyether: purchased from Jiahe Chemical (Binzhou) Co., Ltd., product numbers: PP3645, PP3630.

[0050] Chain extender: purchased from Jiangsu Sirbang Petrochemical Co., Ltd., product number: diethanolamine.

[0051] Catalyst A1: Purchased from Anhui Hengguang Polyurethane Materials Co., Ltd., item number: Catalyst A-1.

[0052] Catalyst A33: Purchased from Anhui Hengguang Polyurethane Materials Co., Ltd., item number: A-33.

[0053] Open-pore silicone oil: purchased from Jiahe Chemical Quanzhou Co., Ltd., product number: F5570.

[0054] Closed-cell silicone oil: purchased from Jiahe Chemical Quanzhou Co., Ltd., product number: Z6916.

[0055] Opening agent: purchased from Shanghai Fujia Fine Chemical Co., Ltd., item number: C1510.

[0056] Modified isocyanate (isocyanate group content 26%): purchased from Shanghai Fujia Fine Chemical Co., Ltd., item number: M26.

[0057] Example 1

[0058] This embodiment provides a method for preparing polyether polyols using a bimetallic cyanide catalyst, comprising the following steps:

[0059] (1) In a 2L stainless steel reactor at room temperature, add 225g of glycerol polyoxyethylene polyoxypropylene ether, 0.0525g of DMC catalyst and 0.018g of phosphoric acid.

[0060] (2) Seal the reactor, maintain pressure and test for leaks, evacuate, raise the temperature to 120℃ and remove trace amounts of moisture by nitrogen blowing, and dehydrate for 60 minutes under a pressure of -0.095MPa; close the vacuum valve and stop the vacuum, and add 40g of a mixture of propylene oxide and ethylene oxide (mass ratio EO:PO = 75:25) at a temperature of 125℃ and a pressure of -0.1MPa to initiate the reaction, which is initiated by the DMC catalyst. The total flow rate of the mixture of propylene oxide and ethylene oxide is 80g / min. 2-5 minutes after the feeding is completed, the initiation reaction is characterized by a rapid decrease in pressure and a rapid increase in temperature.

[0061] (3) After the reaction is initiated, the pressure inside the reactor stops decreasing and the temperature stops rising, indicating that the reaction is fully matured. At this time, the pressure inside the reactor is -0.1 MPa. A mixture of propylene oxide and ethylene oxide (mass ratio EO:PO = 75:25) is added to the reactor in stages for polymerization. The feed amount of the mixture of propylene oxide and ethylene oxide (mass ratio EO:PO = 75:25) is 308.75 g in each stage, as detailed below:

[0062] First stage: The initial reactor pressure in this stage is -0.1 MPa. A mixture of propylene oxide and ethylene oxide is added at a flow rate of 3 g / min. In this stage, P1 is -0.09 MPa, P2 is -0.01 MPa, and P2-P1 = 0.08 MPa. When the feeding is completed, the reactor pressure Py is -0.05 MPa. At this time, nitrogen is added until the reactor pressure Px is 0 MPa, and Px-Py = 0.05 MPa. The reaction temperature in this stage is controlled at 125℃.

[0063] Second stage: Continue to add the mixture of propylene oxide and ethylene oxide at a flow rate of 3 g / min. At this time, P1 is 0 MPa, P2 is 0.08 MPa, P2-P1=0.08 MPa, and the reactor pressure Py is 0.05 MPa when the feeding is completed. At this time, nitrogen gas is added until the reactor pressure Px is 0.1 MPa, Px-Py=0.05 MPa. The reaction temperature in this stage is controlled at 125℃.

[0064] Third stage: Continue to add the mixture of propylene oxide and ethylene oxide at a flow rate of 3 g / min. In this stage, P1 is 0.1 MPa, P2 is 0.17 MPa, P2-P1 = 0.07 MPa, and the reactor pressure Py when the feeding is completed is 0.16 MPa. At this time, nitrogen is added until the reactor pressure Px is 0.2 MPa, Px-Py = 0.04 MPa. The reaction temperature in this stage is controlled at 125℃.

[0065] Fourth stage: Continue to add the mixture of propylene oxide and ethylene oxide at a flow rate of 3 g / min. In this stage, P1 is 0.2 MPa, P2 is 0.28 MPa, P2-P1=0.08 MPa, and the reaction temperature is controlled at 125℃. This is the final stage of the reaction. No more nitrogen is added to the reactor. The reaction ends, and the pressure in the reactor at the end is 0.24 MPa.

[0066] (4) After the reaction is completed, age the mixture until the pressure inside the reactor is maintained for 30 minutes without dropping. Remove excess water and unreacted propylene oxide and ethylene oxide mixture at 125℃ and -0.094MPa for 30 minutes. Then, cool the mixture to 90℃ and discharge the product to obtain the target polyether polyol 1, which is glycerol polyoxyethylene polyoxypropylene ether 1 (Mn = 4000, hydroxyl equivalent: 1333g / mol; obtained by NMR detection, the primary hydroxyl groups in the polyether polyol 1 account for 67.6% of all hydroxyl groups).

[0067] The hydroxyl value of polyether polyol 1 is 43.08 mg KOH / g; the viscosity is 934 mpa·s / 25℃, and the appearance is clear and transparent; and at 5℃, the product is still liquid with a viscosity of 4700 mpa·s; the polydispersity index (PDI) is 1.1327.

[0068] Example 2

[0069] This embodiment provides a method for preparing polyether polyols using a bimetallic cyanide catalyst, comprising the following steps:

[0070] (1) In a 2L stainless steel reactor, at room temperature, add 225g of glycerol polyoxyethylene polyoxypropylene ether (Mn=600, mass ratio EO:PO=75:25), 0.0525g of DMC catalyst, and 0.018g of phosphoric acid.

[0071] (2) Seal the reactor, maintain pressure and test for leaks, evacuate, raise the temperature to 120℃ and remove trace amounts of moisture by nitrogen blowing, and dehydrate for 60 minutes under a pressure of -0.095MPa; close the vacuum valve and stop the vacuum, and add 40g of a mixture of propylene oxide and ethylene oxide (mass ratio EO:PO = 75:25) at a temperature of 123℃ and a pressure of -0.1MPa to initiate the reaction, which is initiated by the DMC catalyst. The total flow rate of the mixture of propylene oxide and ethylene oxide is 80g / min. 2-5 minutes after the feeding is completed, the initiation reaction is characterized by a rapid decrease in pressure and a rapid increase in temperature.

[0072] (3) After the reaction is initiated, the pressure inside the reactor stops decreasing and the temperature stops rising, indicating that the reaction is fully matured. At this time, the pressure in the reactor is -0.1 MPa. Nitrogen gas is added to the reactor until the pressure reaches 0 MPa. Then, a mixture of propylene oxide and ethylene oxide (mass ratio EO:PO = 75:25) is added in stages, with a total amount of 1235 g. The feed amount of the mixture of propylene oxide and ethylene oxide (mass ratio EO:PO = 75:25) is 308.75 g in each stage, as detailed below:

[0073] First stage: The initial reactor pressure in this stage is 0 MPa. A mixture of propylene oxide and ethylene oxide is added at a flow rate of 3 g / min. In this stage, P1 is 0 MPa, P2 is 0.08 MPa, and P2-P1 = 0.08 MPa. When the feeding is completed, the reactor pressure Py is 0.05 MPa. At this time, nitrogen is added until the reactor pressure Px is 0.1 MPa, and Px-Py = 0.05 MPa. The reaction temperature in this stage is controlled at 125℃.

[0074] Second stage: Continue to add the mixture of propylene oxide and ethylene oxide at a flow rate of 3 g / min. In this stage, P1 is 0.1 MPa, P2 is 0.19 MPa, P2-P1 = 0.09 MPa, and the reactor pressure Py when the feeding is completed is 0.15 MPa. At this time, nitrogen is added until the reactor pressure Px is 0.2 MPa, Px-Py = 0.05 MPa. The reaction temperature in this stage is controlled at 125℃.

[0075] Third stage: Continue to add the mixture of propylene oxide and ethylene oxide at a flow rate of 3 g / min. In this stage, P1 is 0.2 MPa, P2 is 0.28 MPa, P2-P1 = 0.08 MPa, and the reactor pressure Py when the feeding is completed is 0.26 MPa. At this time, nitrogen is added until the reactor pressure Px is 0.3 MPa, Px-Py = 0.04 MPa. The reaction temperature in this stage is controlled at 125℃.

[0076] Fourth stage: Continue to add the mixture of propylene oxide and ethylene oxide at a flow rate of 3 g / min. In this stage, P1 is 0.3 MPa, P2 is 0.39 MPa, P2-P1=0.09 MPa, and the reaction temperature is controlled at 125℃. This is the final stage of the reaction. No more nitrogen is added to the reactor. The reaction ends, and the pressure in the reactor at the end is 0.35 MPa.

[0077] (4) After the reaction is completed, age the mixture until the pressure inside the reactor remains constant for 30 minutes. Remove excess water and unreacted propylene oxide and ethylene oxide mixture at 124℃ and -0.093MPa for 30 minutes. Then, cool the mixture to 90℃ to discharge the product and obtain the target polyether polyol 2, which is glycerol polyoxyethylene polyoxypropylene ether 2 (Mn = 4000, hydroxyl equivalent: 1333g / mol; obtained by NMR detection, the primary hydroxyl groups in the polyether polyol 2 account for 68.1% of all hydroxyl groups).

[0078] The hydroxyl value of polyether polyol 2 is 42.86 mg KOH / g; the viscosity is 838 mpa·s / 25℃, and the appearance is clear and transparent; and at 5℃, the product is still liquid with a viscosity of 4500 mpa·s; the polydispersity index (PDI) is 1.1241.

[0079] Example 3

[0080] This embodiment provides a method for preparing polyether polyols using a bimetallic cyanide catalyst, comprising the following steps:

[0081] (1) In a 2L stainless steel reactor, at room temperature, add 225g of glycerol polyoxyethylene polyoxypropylene ether (Mn=600, mass ratio EO:PO=75:25), 0.0525g of DMC catalyst, and 0.018g of phosphoric acid.

[0082] (2) Seal the reactor, maintain pressure and test for leaks, evacuate, heat to 120℃ and remove trace amounts of moisture by nitrogen blowing, and dehydrate for 60 minutes under a pressure of -0.095MPa; close the vacuum valve and stop the vacuum, and add 40g of a mixture of propylene oxide and ethylene oxide (mass ratio EO:PO = 75:25) at a temperature of 124℃ and a pressure of -0.1MPa to initiate the reaction, which is initiated by the DMC catalyst. The total flow rate of the mixture of propylene oxide and ethylene oxide is 80g / min. 2-5 minutes after the feeding is completed, the initiation reaction is characterized by a rapid decrease in pressure and a rapid increase in temperature.

[0083] (3) After the reaction is initiated, the pressure inside the reactor stops decreasing and the temperature stops rising, indicating that the reaction is fully matured. At this time, the pressure inside the reactor is -0.1 MPa. After adding nitrogen to the reactor to 0 MPa, a mixture of propylene oxide and ethylene oxide (mass ratio EO:PO = 75:25) is added in stages, with a total amount of 1235 g. The feed amount of the mixture of propylene oxide and ethylene oxide (mass ratio EO:PO = 75:25) is 308.75 g in each stage, as detailed below:

[0084] First stage: The initial reactor pressure in this stage is 0 MPa. A mixture of propylene oxide and ethylene oxide is added at a flow rate of 5 g / min. In this stage, P1 is 0 MPa, P2 is 0.13 MPa, and P2-P1 = 0.13 MPa. When the feeding is completed, the reactor pressure Py is 0.11 MPa. At this time, nitrogen is added until the reactor pressure Px is 0.15 MPa, and Px-Py = 0.04 MPa. The reaction temperature in this stage is controlled at 125℃.

[0085] Second stage: Continue to add the mixture of propylene oxide and ethylene oxide at a flow rate of 5 g / min. In this stage, P1 is 0.15 MPa, P2 is 0.27 MPa, P2-P1=0.12 MPa, and the reactor pressure Py is 0.25 MPa when the feed is completed. At this time, nitrogen is added until the reactor pressure Px is 0.3 MPa, Px-Py=0.05 MPa. The reaction temperature in this stage is controlled at 125℃.

[0086] Third stage: Continue to add the mixture of propylene oxide and ethylene oxide at a flow rate of 5 g / min. In this stage, P1 is 0.3 MPa, P2 is 0.43 MPa, P2-P1 = 0.13 MPa, and the reactor pressure Py when the feeding is completed is 0.41 MPa. At this time, nitrogen is added until the reactor pressure Px is 0.45 MPa, Px-Py = 0.04 MPa. The reaction temperature in this stage is controlled at 125℃.

[0087] Fourth stage: Continue to add the mixture of propylene oxide and ethylene oxide at a flow rate of 5 g / min. In this stage, P1 is 0.45 MPa, P2 is 0.58 MPa, P2-P1=0.13 MPa, and the reaction temperature is controlled at 125℃. This is the final stage of the reaction. No more nitrogen is added to the reactor. The reaction ends, and the pressure in the reactor at the end is 0.51 MPa.

[0088] (4) After the reaction is completed, age the mixture until the pressure inside the reactor remains constant for 30 minutes. Remove excess water and unreacted propylene oxide and ethylene oxide mixture at 124℃ and -0.092MPa for 30 minutes. Then, cool the mixture to 90℃ to discharge the product and obtain the target polyether polyol 3, which is glycerol polyoxyethylene polyoxypropylene ether 3 (Mn = 4000, hydroxyl equivalent: 1333g / mol; obtained by NMR detection, the primary hydroxyl groups in the polyether polyol 3 account for 66.5% of all hydroxyl groups).

[0089] The hydroxyl value of polyether polyol 3 is 42.26 mg KOH / g; the viscosity is 1148 mpa·s / 25℃, and the appearance is clear and transparent; and at 5℃, the product is still liquid with a viscosity of 5500 mpa·s; the polydispersity index (PDI) is 1.1620.

[0090] Example 4

[0091] This embodiment provides an inflatable, slow-rebound polyurethane foam, the formulation of which is listed in Table 1:

[0092] Table 1. Inflatable Slow-Rebound Polyurethane Foam Formulation

[0093] Component Mass parts Polyether polyol 2 prepared in Example 2 70 Grafted polyether 10 Chain extender 20 Catalyst A1 0.05 Catalyst A33 0.25 Foam stabilizer: open-cell silicone oil 0.8 Foam stabilizer: closed-cell silicone oil 0.6 Water 3.2 Open-cell agent 3.5

[0094] This embodiment provides a method for preparing inflatable slow-rebound polyurethane foam, including the following steps:

[0095] (1) The white material is prepared by completely mixing the glycerol polyoxyethylene polyoxypropylene ether 2, grafted polyether, chain extender, catalysts A1 and A33, foam stabilizer (open-cell silicone oil and closed-cell silicone oil), water and open-cell agent obtained in Example 2 with the above mass parts; the modified isocyanate (isocyanate group content is 26%) is the black material.

[0096] (2) Under the conditions of ambient temperature of 22℃ and material temperature of 25℃, white material and black material are mixed at a mass ratio of 100:60, the stirring speed is 4000rpm, the stirring time is 6s, the mixture is foamed, and then quickly poured into a box mold for foaming to obtain inflatable slow rebound polyurethane foam.

[0097] Example 5

[0098] The difference from Example 4 is that the polyether polyol 2 prepared in Example 2 is replaced with an equal mass of polyether polyol 1 prepared in Example 1, and the other steps are the same as in Example 4, to obtain an inflatable slow rebound polyurethane foam.

[0099] Example 6

[0100] The difference from Example 4 is that the polyether polyol 2 prepared in Example 2 is replaced with an equal mass of polyether polyol 3 prepared in Example 3. The other steps are the same as in Example 4, and the inflatable slow rebound polyurethane foam is obtained.

[0101] Comparative Example 1

[0102] The difference from Example 1 lies in step (3). The operation of this comparative example is as follows: after the reaction is initiated, the pressure in the reactor no longer decreases and the temperature no longer increases, indicating that the reaction is fully matured. At this time, the pressure in the reactor is -0.1 MPa. A mixture of propylene oxide and ethylene oxide (mass ratio EO:PO = 75:25) with a total amount of 1235 g is added directly to the reactor at a flow rate of 3 g / min. During this stage, P1 is -0.1 MPa, P2 is 0 MPa, and P2-P1 = 0.1 MPa. No nitrogen is added to the reactor during the entire reaction stage. The reaction ends when the feeding is completed. Other steps are the same as in Example 1, and the target polyether polyol 4 is obtained, which is glycerol polyoxyethylene polyoxypropylene ether 4 (Mn = 4000, hydroxyl equivalent: 1333 g / mol, obtained by NMR detection, the primary hydroxyl groups in the polyether polyol 4 account for 61.8% of all hydroxyl groups).

[0103] The hydroxyl value of polyether polyol 4 is 42.9 mg KOH / g; the viscosity is 1200 mpa·s / 25℃, and the appearance is clear and transparent; at 5℃, the product is still liquid and the viscosity is 6100 mpa·s; the polydispersity is 1.1864.

[0104] Comparative Example 2

[0105] The difference from Example 1 lies in step (3). Step (3) of this comparative example is as follows: After the reaction is initiated, the pressure inside the reactor no longer decreases and the temperature no longer increases, indicating that the reaction is fully matured. At this time, the pressure inside the reactor is -0.1 MPa. A mixture of propylene oxide and ethylene oxide (mass ratio EO:PO = 75:25) with a total amount of 1235g is added to the reactor in stages for polymerization. The mixture of propylene oxide and ethylene oxide (mass ratio EO:PO = 75:25) is fed in 308.75g at each stage, as follows:

[0106] First stage: The initial reactor pressure in this stage is -0.1 MPa. A mixture of propylene oxide and ethylene oxide is added at a flow rate of 10 g / min. In this stage, P1 is -0.1 MPa, P2 is 0.14 MPa, and P2-P1 = 0.24 MPa. When the feed is completed, the reactor pressure Py is 0.11 MPa. At this time, nitrogen is added until the reactor pressure Px is 0.15 MPa, and Px-Py = 0.04 MPa. The reaction temperature in this stage is controlled at 125℃.

[0107] Second stage: Continue to add the mixture of propylene oxide and ethylene oxide at a flow rate of 10 g / min. At this time, P1 is 0.15 MPa, P2 is 0.41 MPa, P2-P1=0.26 MPa, and the reactor pressure Py is 0.35 MPa when the feeding is completed. At this time, nitrogen gas is added until the reactor pressure Px is 0.40 MPa, Px-Py=0.05 MPa. The reaction temperature in this stage is controlled at 125℃.

[0108] Third stage: Continue to add the mixture of propylene oxide and ethylene oxide at a flow rate of 10 g / min. In this stage, P1 is 0.40 MPa, P2 is 0.63 MPa, P2-P1 = 0.23 MPa, and the reactor pressure Py when the feeding is completed is 0.56 MPa. At this time, nitrogen is added until the reactor pressure Px is 0.60 MPa, Px-Py = 0.04 MPa. The reaction temperature in this stage is controlled at 125℃.

[0109] Fourth stage: Continue to add the mixture of propylene oxide and ethylene oxide at a flow rate of 10 g / min. In this stage, P1 is 0.60 MPa, P2 is 0.85 MPa, P2-P1 = 0.25 MPa, and the reaction temperature is controlled at 125℃. This is the final stage of the reaction. No more nitrogen is added to the reactor. The reaction ends, and the pressure in the reactor at the end is 0.76 MPa.

[0110] The other steps are the same as in Example 1, and the target polyether polyol 5 is obtained, which is glycerol polyoxyethylene polyoxypropylene ether 5 (Mn = 4000, hydroxyl equivalent: 1333 g / mol, obtained by NMR detection, the primary hydroxyl groups in the polyether polyol 5 account for 63.7% of all hydroxyl groups).

[0111] The hydroxyl value of polyether polyol 5 is 42.7 mg KOH / g; the viscosity is 1330 mpa·s / 25℃, and the appearance is clear and transparent; at 5℃, the product is still liquid and the viscosity is 6700 mpa·s; the polydispersity is 1.2223.

[0112] Comparative Example 3

[0113] The difference from Example 4 is that the polyether polyol 2 prepared in Example 2 is replaced with an equal mass of the polyether polyol 4 prepared in Comparative Example 1. The other steps are the same as in Example 4, and the inflatable slow rebound polyurethane foam is obtained.

[0114] Comparative Example 4

[0115] The difference from Example 4 is that the polyether polyol 2 prepared in Example 2 is replaced with an equal mass of the polyether polyol 5 prepared in Comparative Example 2. The other steps are the same as in Example 4, and the inflatable slow rebound polyurethane foam is obtained.

[0116] Experiment Example 1: Foaming Test

[0117] Test methods: The expansion-promoting slow-rebound polyurethane foams prepared in Examples 4-6, Comparative Examples 3 and 4 of this invention were tested for foaming time, fiber drawing time, and free rise time according to HG / T 4574-2014 "Determination of Foaming Reaction Characteristics of Polyurethane Raw Materials"; their 25%, 40%, and 65% indentation hardness were tested according to GB / T 10807-2006 "Determination of Hardness of Flexible Foam Polymer Materials (Indentation Method)". The test results are shown in Table 2 below:

[0118] Table 2 Foaming Test Results

[0119]

[0120] Table 2 shows that in the foaming test, Examples 4-6 used the polyether polyol prepared by the method of preparing polyether polyol using a bimetallic cyanide catalyst provided by the present invention as raw material to prepare slow-rebound polyurethane foam with relatively stable properties. During the test, it was observed that the foam did not shrink, collapse or sink. Compared with Examples 4-6, it was found that the foams of Comparative Examples 3 and 4 showed relatively slow reaction activity and an increasing trend of foam hardness, resulting in unstable foam properties. This indicates that the slow-rebound polyurethane foam prepared by using the polyether polyol provided by the present invention as raw material has good stability.

[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 a polyether polyol using a double metal cyanide catalyst, characterized in that, The method comprises the following steps: S1: adding polyol, double metal cyanide catalyst and protonic acid into a closed reactor; S2: heating the closed reactor to a reaction temperature, and introducing ethylene oxide and other epoxy compounds to initiate the reaction; S3: after the initiation reaction is completed, a mixture of ethylene oxide and other epoxy compounds is added into the closed reactor in multiple stages to carry out the polymerization reaction, wherein the minimum value of the reaction pressure of each stage is P1, the maximum value of the reaction pressure of each stage is P2, and the units of P1 and P2 are MPa, wherein P1 and P2 of each stage satisfy 0 The pressure in the closed reactor when the feeding of each stage is completed is Py, and nitrogen is filled after the feeding of each stage is completed to increase the pressure in the closed reactor to Px, except for the last stage, wherein the units of Py and Px are MPa, and Px and Py satisfy 0 S4: after the reaction is completed, aging and degassing are carried out to obtain polyether polyol.

2. The process for preparing polyether polyols using double metal cyanide catalyst according to claim 1, characterized in that, In S3, the temperature of the polymerization reaction is 80-135℃; And / or, the P1 and P2 satisfy 0 And / or, the P1 satisfies -0.1≤P1≤0.8MPa; And / or, the P2 satisfies -0.01≤P2<1.0MPa; And / or, the Px satisfies 0≤Px≤0.8MPa; And / or, the Py satisfies -0.05≤Py≤0.9MPa; And / or, the multiple stages are divided into 2-5 stages, and the mass of ethylene oxide and other epoxy compounds added in each stage accounts for 20-50% of the total mass of ethylene oxide and other epoxy compounds added in S3.

3. The process for preparing polyether polyols using double metal cyanide catalyst according to claim 1, characterized in that, In S2 or S3, the weight ratio of the other epoxy compounds to ethylene oxide is 95:5-5:95, preferably 60:40-5:95, and more preferably 25:

75.

4. Process for the preparation of polyether polyols using double metal cyanide catalysts according to any of claims 1 to 3, characterized in that The other epoxy compounds are selected from at least one of propylene oxide, 1,2-epoxybutane, 2,3-epoxybutane, tetrahydrofuran and 1,2-epoxypentane, and propylene oxide is preferred.

5. The process for preparing polyether polyols using double metal cyanide catalyst according to claim 1, characterized in that, In S1, the polyol is polyether polyol; Optionally, the functionality of the polyether polyol is 1-8, and the hydroxyl equivalent weight is >100g / mol; More optionally, the polyether polyol is selected from at least one of glycerol polyoxyethylene polyoxypropylene ether, propylene glycol polyoxyethylene polyoxypropylene ether and dipolyglycerol polyoxyethylene polyoxypropylene ether; And / or, the addition amount of the double metal cyanide catalyst is 5-100ppm based on the total mass of the polyol and ethylene oxide and other epoxy compounds added in S2 and S3; And / or, the protonic acid is selected from at least one of nitric acid, phosphoric acid and sulfuric acid; And / or, the mass of the protonic acid accounts for 40-200ppm of the mass of the polyol. And / or, the step S2 further comprises a step of passing protective gas to remove water after the temperature rising; Optionally, the temperature of the temperature rising and the water removing is 50-160℃; Optionally, the protective gas is at least one selected from nitrogen, carbon dioxide, helium and argon; And / or, in the step S4, the temperature of the degassing is 50-165℃, the pressure is -0.085 to -0.095 MPa, and the time is 15-120 min.

6. The process for preparing polyether polyols using double metal cyanide catalyst according to claim 1, characterized in that, In the step S2, the temperature of the initiating reaction is 120-155℃; And / or, the total mass of the ethylene oxide and other epoxy compounds added in the step S2 is 10-50% of the mass of the polyol.

7. The polyether polyol prepared by the method of any one of claims 1-6.

8. The polyether polyol of claim 7, wherein, The hydroxyl equivalent weight of the polyether polyol is 1300-3000 g / mol; And / or, the mole percentage of the primary hydroxyl group in the polyether polyol is 50-90% of all the hydroxyl groups in the polyether polyol.

9. An aerated slow-rebound polyurethane foam characterized by, The raw materials include, by weight, 60-80 parts of the polyether polyol of claim 8, 50-70 parts of isocyanate and / or modified isocyanate, 2-5 parts of blowing agent, 10-30 parts of chain extender, 5-15 parts of grafted polyether, 0.01-0.5 parts of catalyst, 0.3-2 parts of foam stabilizer, and 2-5 parts of cell opener.

10. A process for the preparation of a gas blown, slow-rebound polyurethane foam as claimed in claim 9, characterized in that, The method comprises the following steps: After mixing the polyether polyol, blowing agent, chain extender, grafted polyether, catalyst, foam stabilizer and cell opener, the mixture is reacted with isocyanate and / or modified isocyanate to prepare the slow rebound polyurethane foam; optionally, the ambient temperature of the reaction is 20-30℃, and optionally, the material temperature of the reaction is 22-24℃.

Images