A process for the preparation of a low odor high molecular weight high activity polyether polyol

Abstract

The application discloses a preparation method of a low-odor high-molecular-weight high-activity polyether polyol. The method is a step-by-step polymerization method for preparing a high-molecular-weight high-activity crude polyether polyol capped by ethylene oxide, and an organic acid is used as a refining agent of the polyether polyol, so that the odor of the polyether product can be effectively removed, and finally the high-activity polyether polyol with a low odor and a hydroxyl value of 8-70 mgKOH / g is obtained.

Description

Technical Field

[0001] This invention relates to a method for preparing a low-odor, high-molecular-weight, highly active polyether polyol, belonging to the field of organic synthesis technology. Background Technology

[0002] This invention uses a stepwise polymerization method to prepare ethylene oxide-terminated high molecular weight, highly active crude polyether polyol, and uses organic acid as a refining agent for the polyether polyol, which can effectively remove the odor of the polyether product.

[0003] Traditional polyether polyol production uses alkali metal compounds as catalysts. After the polymerization reaction, a neutralizing agent is added to remove the alkali metal compounds; this process is called the purification process of polyether polyols. The introduction of neutralizing agents and other substances during purification can introduce odors into the polyether product. Therefore, many studies have made changes at this stage to reduce the odor of the polyether product.

[0004] CN109438691A reports a method for preparing a low-odor polyether polyol. The method uses a polyol compound as a starting agent and reacts it with potassium hydroxide as a catalyst at a pressure of 0-0.4 MPa and a temperature of 80-140 °C, with a space velocity of 20-25 h⁻¹. -1 Propylene oxide, after being treated with adsorption and aldehyde reduction in a molecular sieve tank, is polymerized in steps and capped with ethylene oxide to obtain crude polyether. After neutralization and adsorption, the crude polyether is then added to an aqueous isopropanol solution and reacted at 60-80℃ for 30 min. The product is then distilled under reduced pressure to obtain a low-odor polyether polyol. The polyol contains 1%-16% polyol compounds, 67.5%-90.8% propylene oxide, 8%-16% ethylene oxide, and 0.2%-0.5% alkali metal hydroxide. The resulting polyether polyol product has an odor level ≤2.5 and good environmental performance.

[0005] CN108484896A describes a method for preparing low-VOC, high-activity, high-molecular-weight polyether polyols. Using glycerol as a starting agent, a polymerization reaction is carried out with propylene oxide under the action of a low-alkali catalyst. The reaction is then capped with ethylene oxide. The high-activity, high-molecular-weight polyether polyol, catalyzed by the low-alkali catalyst, is added to a closed reactor, along with deionized water and a highly efficient refining adsorbent. Nitrogen purging is performed, and the mixture is mixed, refined, and adsorbed at a specific temperature. After dehydration and filtration, the low-VOC, high-activity, high-molecular-weight polyether polyol product is obtained. This invention simplifies the process flow, eliminates the need for acid neutralization, and avoids the generation of aldehydes during neutralization. By using a highly efficient refining adsorbent, aldehydes and other impurities generated during the polyether polyol production process can be effectively adsorbed, ultimately reducing the VOC content in the polyether polyol. This method is suitable for the preparation of low-VOC, high-activity, high-molecular-weight polyether polyols.

[0006] CN108059717A discloses a purification method for low-odor polyether polyols and its applications. The purification method includes the following steps: 1. Adding water and a compounded antioxidant to crude polyether polyol; 2. Neutralizing with a neutralizing agent, followed by adsorption with an adsorbent; 3. Dehydrating under negative pressure and filtering to obtain the purified polyether polyol; wherein the crude polyether polyol is a polyether polyol synthesized using an alkali metal catalyst, and the compounded antioxidants include antioxidant 1010 and antioxidant DPDP. This purification method effectively reduces the odor of polyethers while maximizing the removal of alkali metal catalysts. Summary of the Invention

[0007] This invention discloses a method for preparing low-odor, high-molecular-weight, and highly active polyether polyols. The method employs a stepwise polymerization process to prepare ethylene oxide-terminated high-molecular-weight, highly active crude polyether polyols, and uses organic acids as a refining agent for the polyether polyols to effectively remove the odor from the polyether products, ultimately yielding highly active polyether polyols with a hydroxyl value of 8-70 mgKOH / g and low odor.

[0008] On one hand, the present invention provides a method for preparing polyether polyols, comprising the steps of:

[0009] Preparation of S1 intermediate 1: Using a small molecule polyol compound as the starting polymer, it is contacted with the first alkali metal catalyst, and one or more epoxy compounds I are added at a temperature of 110-130℃ to prepare intermediate 1 with a hydroxyl value of 55-300 mgKOH / g.

[0010] Preparation of S2 intermediate 2: Intermediate 1 is contacted with a second alkali metal catalyst and subjected to ring-opening polymerization at a temperature of 110-130°C to generate one or more epoxy compounds II, thereby obtaining intermediate 2 with a hydroxyl value of 20-180 mgKOH / g.

[0011] Preparation of S3 intermediate 3: Intermediate 2 is contacted with a third alkali metal catalyst, and ring-opening polymerization is carried out at a temperature of 110-130°C to generate one or more epoxy compounds III, thereby obtaining intermediate 3 with a hydroxyl value of 10-100 mgKOH / g.

[0012] Preparation of S4 polyether polyol: The intermediate 3 is mixed with ethylene oxide, and the intermediate 3 is subjected to ring-opening polymerization with ethylene oxide at a temperature of 100-130°C to obtain the polyether polyol.

[0013] The starting polymers used in this invention include alcohols, sugars, etc.

[0014] Alcohols include divalent alcohols such as water, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,3-propanediol, 1,4-cyclohexanediol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, and 1,4-cyclohexanediol; and polyvalent alcohols such as glycerol, trimethylolpropane, pentaerythritol, dipentaerythritol, tripentaerythritol, and polyglycidol.

[0015] Sugars include glucose, sorbitol, dextrose, levulose, sucrose, methyl glucoside, hydroxyethyl glucoside, and other sugars or their derivatives.

[0016] Optionally, the small molecule polyol compound is selected from at least one of ethylene glycol, 1,2-propanediol, glycerol, pentaerythritol, sorbitol, mannitol, and sucrose.

[0017] Optionally, in S1, the mass ratio of the small molecule alcohol compound, the first alkali metal catalyst, and the epoxy compound I ranges from 1:0.005 to 0.17:5 to 10.

[0018] Optionally, in S2, the mass ratio of intermediate 1, the second alkali metal catalyst, and epoxide II is in the range of 1:0.003 to 0.1:0.5 to 6.

[0019] Optionally, in S3, the mass ratio of intermediate 2, the third alkali metal catalyst, and epoxide III is in the range of 1:0.002 to 0.1:0.5 to 6.

[0020] Optionally, in S4, the mass ratio of intermediate 3 to ethylene oxide is in the range of 1:0.08 to 0.5.

[0021] Optionally, epoxy compound I, epoxy compound II, and epoxy compound III are each independently selected from at least one of propylene oxide, ethylene oxide, butane oxide, styrene oxide, cyclohexane oxide, epichlorohydrin, bromopropylate, methyl glycidyl ether, and allyl glycidyl ether.

[0022] The epoxy compounds polymerized during the preparation of intermediates in this invention include propylene oxide, ethylene oxide, butane oxide, styrene oxide, cyclohexane oxide, epichlorohydrin, bromopropylidene oxide, methyl glycidyl ether, allyl glycidyl ether, etc. Two or more epoxides can also be used in combination. Preferably, propylene oxide, ethylene oxide, butane oxide, and styrene oxide are used; more preferably, propylene oxide and ethylene oxide are used. In the manufacture of alkoxylated compounds, propylene oxide is most preferably used.

[0023] Stepwise polymerization, with alkali metal catalyst added at each step to ensure its dosage is 0.002%-0.17% based on the initiator or intermediate of the polymerization stage. Because epoxides readily isomerize to form double bonds in an alkaline environment, and further oxidize to aldehydes under heating conditions, stepwise addition of the alkali metal catalyst required for the synthesis of the target polyether polyol can reduce the amount of alkaline substances in the environment during polymerization, effectively inhibiting the formation of aldehydes during the polymerization reaction.

[0024] The maximum pressure during the addition polymerization of the epoxide is preferably below 0.8 MPa(G). When the maximum pressure of the epoxide exceeds 0.8 MPa(G), the content of the monohydric alcohol (total unsaturation) as a byproduct of propylene oxide increases. The maximum reaction pressure is preferably below 0.6 MPa(G), and most preferably below 0.5 MPa(G). The epoxide can be supplied to the polymerization system in batches or in a continuous manner.

[0025] Optionally, the amount of alkali metal catalyst used is a calculated value, and the total mass of alkali metal is 0.078% to 0.26% of the small molecule polyol.

[0026] Optionally, the alkali metal catalyst is selected from at least one of NaOH, KOH, and NaH.

[0027] Optionally, the end-sealing treatment is carried out in a nitrogen environment with a nitrogen pressure of 0.01 MPa to 0.4 MPa.

[0028] Optionally, the end-capping treatment yields an end-capped product; the method further includes a step of purifying the end-capped product; the purification step includes sequential organic acid treatment and inorganic acid treatment.

[0029] Optionally, the organic acid is selected from at least one of cyclopentanoic acid, cyclohexanoic acid, oxalic acid, adipic acid, cyclohexanoic acid, and cyclopentanoic acid.

[0030] Optionally, the inorganic acid is selected from at least one of phosphoric acid, hydrochloric acid, and sulfuric acid.

[0031] Optionally, the organic acid is used to neutralize the alkali metal catalyst in the capped product.

[0032] Optionally, the mass ratio of the organic acid to the end-capping product is 1:115 to 440.

[0033] Optionally, the inorganic acid is used to adjust the pH value; the pH is adjusted to 5.2 to 7.0.

[0034] Optionally, the hydroxyl value of the polyether polyol is 8 to 70 mg KOH / g.

[0035] Optionally, it can be used in the preparation of polyurethane or as a lubricant, brake fluid, or resin modifier;

[0036] The polyurethane is selected from at least one of semi-rigid and flexible polyurethane foams, coatings, adhesives, bedding materials, waterproofing materials, elastomers, sealants, and shoe soles.

[0037] The ethylene oxide end-capping reaction is carried out in the presence of nitrogen, which effectively avoids insufficient primary hydroxyl groups in the product due to homopolymerization caused by the high reactivity of ethylene oxide. The nitrogen pressure is 0.01 MPa-0.4 MPa, preferably 0.05-0.1 MPa.

[0038] After the epoxide is added, the pressure inside the polymerization reactor will slowly decrease. The reaction is controlled based on the hydroxyl value of the polyether polyol. The polymerization is generally carried out until the hydroxyl value is between 8 and 120 mg KOH / g.

[0039] When manufacturing polyether polyols using the above method, after the epoxide polymerization is completed, a catalyst-containing polyether polyol (hereinafter referred to as crude polyol) is obtained, and it is usually necessary to remove the catalyst from the crude polyol.

[0040] The final product uses a refining agent to remove the alkali metal catalyst. However, unlike the traditional polyether refining process which uses inorganic acid neutralization, this invention employs organic acid neutralization and inorganic acid to control the pH value. This effectively avoids the characteristic odor and side reactions caused by the introduction of phosphoric acid during the neutralization process in traditional methods. Organic acids include one or a mixture of several of cyclopentanoic acid, cyclohexanoic acid, oxalic acid, adipic acid, and cyclohexanoic acid, while inorganic acids include phosphoric acid, hydrochloric acid, and sulfuric acid. The total amount of organic and inorganic acids used is 1-3% based on the amount of polyether polyol product, preferably 1-1.5%, and the contact temperature is preferably in the range of 50-130°C.

[0041] Unlike existing technologies, this invention uses a stepwise polymerization method to prepare ethylene oxide-terminated high molecular weight, highly active crude polyether polyols. It was found that the use of inorganic acids (mainly phosphoric acid) in the traditional neutralization process would give the polyether polyol product a strong odor. By using organic acids as a refining agent and inorganic acids to adjust the product's pH value, this method can effectively remove the odor from the polyether product.

[0042] The method for manufacturing polyether polyols of the present invention effectively reduces the odor in polyols, resulting in polyols with lower odor. Polyether polyols manufactured using the method of the present invention can be widely used in the polyurethane field, including semi-rigid and flexible polyurethane foams, coatings, adhesives, bedding materials, waterproofing materials, elastomers, sealants, and shoe soles. They can also be used in lubricants, brake fluids, and resin modifiers. Detailed Implementation

[0043] Example 1: Preparation of polyether polyol A

[0044] Preparation of Intermediate 1: 200g of ethylene glycol and 1.27g of KOH were added to an automated pressure vessel (hereinafter referred to as the automated vessel) equipped with a stirrer, temperature controller, pressure gauge, nitrogen inlet pipe, and monomer inlet pipe. The air was replaced with nitrogen. Then, under the conditions of polymerization temperature of 110℃ and maximum reaction pressure of 0.3MPa (standard atmospheric pressure), 1006.5g of propylene oxide was added in batches (10-15 batches, each batch not exceeding 100g). After the propylene oxide was completely added, the temperature of the automated vessel was maintained at 110℃~120℃ for 2-3 hours, and the reaction was terminated. Then, under the same temperature, the mixture was subjected to reduced pressure at 665kPa for 30min to obtain Intermediate 1.

[0045] Preparation of Intermediate 2: 200g of Intermediate 1 and 0.84g of KOH were added to an automated reactor. The air was replaced with nitrogen. Then, under polymerization conditions of 110℃ and a maximum reaction pressure of 0.3MPa (standard atmospheric pressure), 800g of propylene oxide was added in batches (8-15 batches, each batch not exceeding 100g). After the propylene oxide was completely added, the temperature of the automated reactor was maintained at 110℃-120℃ for 2-3 hours to terminate the reaction. Then, under the same temperature, the mixture was subjected to reduced pressure at 665kPa for 30min to obtain Intermediate 2.

[0046] Preparation of Intermediate 3: 200g of Intermediate 2 and 1.37g of KOH were added to an automated reactor. The air was replaced with nitrogen. Then, under polymerization conditions of 110℃ and a maximum reaction pressure of 0.3MPa (standard atmospheric pressure), 968g of propylene oxide was added in batches (10-15 batches, each batch not exceeding 100g). After the propylene oxide was completely added, the temperature of the automated reactor was maintained at 110℃-120℃ for 2-3 hours to terminate the reaction. Then, under the same temperature, the mixture was subjected to reduced pressure at 665kPa for 30min to obtain Intermediate 3.

[0047] Preparation of crude polyether polyol A: 200g of intermediate 3 was added to an automated reactor, and the air was replaced with nitrogen. N2 was then introduced into the reactor to bring the pressure to 0.1MPa. Then, under polymerization temperature of 110℃ and maximum reaction pressure of 0.3MPa (standard atmospheric pressure), 75g of ethylene oxide was added in 3-5 batches. After the ethylene oxide was completely added, the temperature of the automated reactor was maintained at 110℃-120℃ for 2-3 hours to terminate the reaction. Then, under the same temperature, the mixture was subjected to reduced pressure at 665kPa for 30min to obtain crude polyether polyol A.

[0048] Purification of polyether polyol A: 500g of crude polyether polyol A is added to an automatic reactor, and 1.14g of cyclohexanoic acid is added as a refining agent at 50℃ for purification. The mixture is stirred and mixed for 1 hour, and then 0.02g-0.03g of hydrochloric acid is added to adjust the pH value of the polyether polyol to between 5.2 and 6.0. Solid salts are removed by filtration to obtain polyether polyol AA.

[0049] Example 2 Preparation of polyether polyol B

[0050] Preparation of Intermediate 1: 400g of 1,2-propanediol and 7.77g of KOH were added to an automated reactor. The air was replaced with nitrogen. Then, under the conditions of polymerization temperature of 130℃ and maximum reaction pressure of 0.4MPa (standard atmospheric pressure), 3290g of propylene oxide was added in batches (33-50 batches, each batch not exceeding 100g). After the propylene oxide was completely added, the temperature of the automated reactor was maintained at 130℃-135℃ for 2-3 hours to terminate the reaction. Then, under the same temperature, the mixture was subjected to reduced pressure at 550kPa for 30min to obtain Intermediate 1.

[0051] Preparation of Intermediate 2: 400g of Intermediate 1 and 2.74g of KOH were added to an automated reactor. The air was replaced with nitrogen. Then, under polymerization conditions of 130℃ and a maximum reaction pressure of 0.3MPa (standard atmospheric pressure), 1307g of propylene oxide was added in batches (14-25 batches, each batch not exceeding 100g). After the propylene oxide was completely added, the temperature of the automated reactor was maintained at 130℃-135℃ for 2-3 hours to terminate the reaction. Then, under the same temperature, the mixture was subjected to reduced pressure at 550kPa for 30min to obtain Intermediate 2.

[0052] Preparation of Intermediate 3: 400g of Intermediate 2 and 1.79g of KOH were added to an automated reactor. The air was replaced with nitrogen. Then, under polymerization conditions of 130℃ and a maximum reaction pressure of 0.4MPa (standard atmospheric pressure), 652g of propylene oxide was added in batches (7-15 batches, each batch not exceeding 100g). After the propylene oxide was completely added, the temperature of the automated reactor was maintained at 130℃-135℃ for 2-3 hours to terminate the reaction. Then, under the same temperature, the mixture was subjected to reduced pressure at 550kPa for 30min to obtain Intermediate 3.

[0053] Preparation of crude polyether polyol B: 200g of intermediate 3 was added to an automated reactor, and the air was replaced with nitrogen. N2 was then introduced into the reactor to bring the pressure to 0.2MPa. Then, under conditions of polymerization temperature of 130℃ and maximum reaction pressure of 0.4MPa (standard atmospheric pressure), 50g of ethylene oxide was added in batches (3-5 batches). After the ethylene oxide was completely added, the temperature of the automated reactor was maintained at 130℃-135℃ for 2-3 hours to terminate the reaction. Then, under the same temperature, the mixture was subjected to reduced pressure at 550kPa for 30min to obtain crude polyether polyol B.

[0054] Purification of polyether polyol B: 500g of crude polyether polyol B is added to an automatic reactor, and 1.62g of oxalic acid and 3g of deionized water are added at 70℃ and stirred for 1h. Then, 0.05g-0.1g of phosphoric acid is added to adjust the pH value of the polyether polyol to between 5.5 and 6.5. The solid salt is removed by filtration to obtain polyether polyol B.

[0055] Example 3 Preparation of polyether polyol C

[0056] Preparation of Intermediate 1: 300g of glycerol and 5.1g of KOH were added to an automated reactor. The air was replaced with nitrogen. Then, 2928g of propylene oxide was added in batches (30-50 batches, each batch not exceeding 100g) under the conditions of polymerization temperature of 120℃ and maximum reaction pressure of 0.4MPa (standard atmospheric pressure). After the propylene oxide was completely added, the temperature of the automated reactor was maintained at 120℃-130℃ for 1-3 hours to terminate the reaction. Then, under the same temperature, the mixture was subjected to reduced pressure at 650kPa for 30min to obtain Intermediate 1.

[0057] Preparation of Intermediate 2: 300g of Intermediate 1 and 0.99g of KOH were added to an automated reactor. The air was replaced with nitrogen. Then, under polymerization conditions of 120℃ and a maximum reaction pressure of 0.4MPa (standard atmospheric pressure), 627g of propylene oxide was added in batches (7-15 batches, each batch not exceeding 100g). After the propylene oxide was completely added, the temperature of the automated reactor was maintained at 120℃-130℃ for 1-3 hours to terminate the reaction. Then, under the same temperature, the mixture was subjected to reduced pressure at 650kPa for 30min to obtain Intermediate 2.

[0058] Preparation of Intermediate 3: 300g of Intermediate 2 and 0.99g of KOH were added to an automated reactor, and the air was replaced with nitrogen. Then, under the conditions of polymerization temperature of 120℃ and maximum reaction pressure of 0.4MPa (standard atmospheric pressure), 527g of propylene oxide was added in batches (6-15 batches, each batch not exceeding 100g). After the propylene oxide was completely added, the temperature of the automated reactor was maintained at 120℃-130℃ for 1-3 hours to terminate the reaction. Then, under the same temperature, the mixture was subjected to reduced pressure at 650kPa for 30min to obtain Intermediate 3.

[0059] Preparation of crude polyether polyol C: 300g of intermediate 3 was added to an automated reactor, and the air was replaced with nitrogen. N2 was then introduced into the reactor to bring the pressure to 0.15MPa. Then, under conditions of polymerization temperature of 130℃ and maximum reaction pressure of 0.4MPa (standard atmospheric pressure), 50g of ethylene oxide was added in batches (3-5 batches). After the ethylene oxide was completely added, the temperature of the automated reactor was maintained at 130℃-135℃ for 1-3 hours to terminate the reaction. Then, under the same temperature, the mixture was subjected to reduced pressure at 650kPa for 30min to obtain crude polyether polyol C.

[0060] Purification of polyether polyol C: 500g of crude polyether polyol C was added to an automatic reactor, and 1.97g of adipic acid and 6g of deionized water were added at 90℃ and stirred for 1h. Then, 0.05g-0.1g of phosphoric acid was added to adjust the pH value of the polyether polyol to between 5.5 and 6.5. The polyether polyol was dehydrated until the water content was no more than 0.04%, and the solid salt was removed by filtration to obtain polyether polyol C.

[0061] Example 4 Preparation of polyether polyol D

[0062] Preparation of Intermediate 1: 500g of pentaerythritol and 6.59g of KOH were added to an automated reactor. The air was replaced with nitrogen. Then, under the conditions of polymerization temperature of 115℃ and maximum reaction pressure of 0.25MPa (standard atmospheric pressure), 3167g of propylene oxide was added in batches (32-50 batches, each batch not exceeding 100g). After the propylene oxide was completely added, the temperature of the automated reactor was maintained at 115℃-125℃ for 2-3 hours to terminate the reaction. Then, under the same temperature, the mixture was subjected to reduced pressure at 600kPa for 30min to obtain Intermediate 1.

[0063] Preparation of Intermediate 2: 500g of Intermediate 1 and 3.58g of KOH were added to an automated reactor. The air was replaced with nitrogen. Then, under polymerization conditions of 115℃ and a maximum reaction pressure of 0.25MPa (standard atmospheric pressure), 2000g of propylene oxide was added in batches (20-40 batches, each batch not exceeding 100g). After the propylene oxide was completely added, the temperature of the automated reactor was maintained at 115℃-125℃ for 2-3 hours to terminate the reaction. Then, under the same temperature, the mixture was subjected to reduced pressure at 600kPa for 30min to obtain Intermediate 2.

[0064] Preparation of Intermediate 3: 500g of Intermediate 2 and 1.28g of KOH were added to an automated reactor. The air was replaced with nitrogen. Then, under the conditions of polymerization temperature of 115℃ and maximum reaction pressure of 0.25MPa (standard atmospheric pressure), 680g of propylene oxide was added in batches (7-15 batches, each batch not exceeding 100g). After the propylene oxide was completely added, the temperature of the automated reactor was maintained at 115℃-125℃ for 2-3 hours to terminate the reaction. Then, under the same temperature, the mixture was subjected to reduced pressure at 600kPa for 30min to obtain Intermediate 3.

[0065] Preparation of crude polyether polyol D: 500g of intermediate 3 was added to an automated reactor, and the air was replaced with nitrogen. N2 was then introduced into the reactor to bring the pressure to 0.1MPa. Then, under conditions of polymerization temperature of 130℃ and maximum reaction pressure of 0.35MPa (standard atmospheric pressure), 40g of ethylene oxide was added in batches (3-5 batches). After the ethylene oxide was completely added, the temperature of the automated reactor was maintained at 130℃-135℃ for 2-3 hours to terminate the reaction. Then, under the same temperature, the mixture was subjected to reduced pressure at 600kPa for 30min to obtain crude polyether polyol D.

[0066] Purification of polyether polyol D: 500g of crude polyether polyol D was added to an automatic reactor, and 2.62g of cyclohexanediol and 5g of deionized water were added at 100℃ and stirred for 1h. Then, 0.02g-0.03g of hydrochloric acid was added to adjust the pH value of the polyether polyol to between 5.2 and 6.2. The polyether polyol was dehydrated until the water content was no more than 0.04%. The solid salt was removed by filtration to obtain polyether polyol D.

[0067] Example 5 Preparation of polyether polyol E

[0068] Preparation of Intermediate 1: 300g of sorbitol and 2.34g of NaH were added to an automated reactor. The air was replaced with nitrogen. Then, under the conditions of polymerization temperature of 115℃ and maximum reaction pressure of 0.25MPa (standard atmospheric pressure), 1550g of propylene oxide was added in batches (15-30 batches, each batch not exceeding 100g). After the propylene oxide was completely added, the temperature of the automated reactor was maintained at 115℃-125℃ for 2-3 hours to terminate the reaction. Then, under the same temperature, the mixture was subjected to reduced pressure at 550kPa for 30min to obtain Intermediate 1.

[0069] Preparation of Intermediate 2: 500g of Intermediate 1 and 3.58g of NaH were added to an automated reactor. The air was replaced with nitrogen. Then, under polymerization conditions of 115℃ and a maximum reaction pressure of 0.25MPa (standard atmospheric pressure), 333g of propylene oxide was added in batches (4-10 batches, each batch not exceeding 100g). After the propylene oxide was completely added, the temperature of the automated reactor was maintained at 115℃-125℃ for 2-3 hours to terminate the reaction. Then, under the same temperature, the mixture was subjected to reduced pressure at 550kPa for 30min to obtain Intermediate 2.

[0070] Preparation of Intermediate 3: 300g of Intermediate 2 and 0.6g of NaH were added to an automated reactor. The air was replaced with nitrogen. Then, under the conditions of polymerization temperature of 115℃ and maximum reaction pressure of 0.25MPa (standard atmospheric pressure), 260g of propylene oxide was added in batches (3-8 batches, each batch not exceeding 100g). After the propylene oxide was completely added, the temperature of the automated reactor was maintained at 115℃-125℃ for 2-3 hours to terminate the reaction. Then, under the same temperature, the mixture was subjected to reduced pressure at 550kPa for 30min to obtain Intermediate 3.

[0071] Preparation of crude polyether polyol E: 300g of intermediate 3 was added to an automated reactor, and the air was replaced with nitrogen. N2 was then introduced into the reactor to bring the pressure to 0.1MPa. Then, under conditions of polymerization temperature of 130℃ and maximum reaction pressure of 0.35MPa (standard atmospheric pressure), 128g of ethylene oxide was added in batches (6-10 batches). After the ethylene oxide was completely added, the temperature of the automated reactor was maintained at 130℃-135℃ for 2-3 hours to terminate the reaction. Then, under the same temperature, the mixture was subjected to reduced pressure at 550kPa for 30min to obtain crude polyether polyol E.

[0072] Purification of polyether polyol E: 500g of crude polyether polyol E is added to an automatic reactor, and 4.3g of cyclohexanediol and 4g of deionized water are added at 115℃ and stirred for 1h. Then, 0.02g-0.03g of hydrochloric acid is added to adjust the pH value of the polyether polyol to between 5.2 and 6.5. The polyether polyol is dehydrated until the water content is no more than 0.04%, and the solid salt is removed by filtration to obtain polyether polyol E.

[0073] Example 6 Preparation of polyether polyol F

[0074] Preparation of Intermediate 1: 342g of sucrose, 62g of ethylene glycol, and 5.61g of NaOH were added to an automated reactor. The air was replaced with nitrogen. Then, under conditions of polymerization temperature of 125℃ and maximum reaction pressure of 0.35MPa (standard atmospheric pressure), 2400 g of propylene oxide was added in batches (24-50 batches, each batch not exceeding 100g). After the propylene oxide was completely added, the temperature of the automated reactor was maintained at 125℃-130℃ for 2-3 hours to terminate the reaction. Then, under the same temperature, the mixture was subjected to reduced pressure at 500kPa for 30 minutes to obtain Intermediate 1.

[0075] Preparation of Intermediate 2: 400g of Intermediate 1 and 1.49g of NaOH were added to an automated reactor. The air was replaced with nitrogen. Then, under the conditions of polymerization temperature of 125℃ and maximum reaction pressure of 0.35MPa (standard atmospheric pressure), 743g of propylene oxide was added in batches (8-20 batches, each batch not exceeding 100g). After the propylene oxide was completely added, the temperature of the automated reactor was maintained at 125℃-130℃ for 2-3 hours to terminate the reaction. Then, under the same temperature, the mixture was subjected to reduced pressure at 500kPa for 30min to obtain Intermediate 2.

[0076] Preparation of Intermediate 3: 400g of Intermediate 2 and 0.8g of NaOH were added to an automated reactor. The air was replaced with nitrogen. Then, under the conditions of polymerization temperature of 125℃ and maximum reaction pressure of 0.35MPa (standard atmospheric pressure), 300g of propylene oxide was added in batches (3-10 batches, each batch not exceeding 100g). After the propylene oxide was completely added, the temperature of the automated reactor was maintained at 125℃-130℃ for 2-3 hours to terminate the reaction. Then, under the same temperature, the mixture was subjected to reduced pressure at 500kPa for 30min to obtain Intermediate 3.

[0077] Preparation of crude polyether polyol F: 400g of intermediate 3 was added to an automated reactor, and the air was replaced with nitrogen. N2 was then introduced into the reactor to bring the pressure to 0.17MPa. Then, under conditions of polymerization temperature of 130℃ and maximum reaction pressure of 0.4MPa (standard atmospheric pressure), 57g of ethylene oxide was added in batches (3-5 batches). After the ethylene oxide was completely added, the temperature of the automated reactor was maintained at 130℃-135℃ for 2-3 hours to terminate the reaction. Then, under the same temperature, the mixture was subjected to reduced pressure at 500kPa for 30min to obtain crude polyether polyol F.

[0078] Purification of polyether polyol F: 500g of crude polyether polyol F was added to an automatic reactor, and 2.69g of cyclopentalic acid and 2g of deionized water were added at 130℃ and stirred for 1h. Then, 0.02g-0.03g of sulfuric acid was added to adjust the pH value of the polyether polyol to between 5.8 and 7.0. The polyether polyol was dehydrated until the water content was no more than 0.04%, and the solid salt was removed by filtration to obtain polyether polyol F.

[0079] Comparative Example 1: Polyether Polyol 1#

[0080] In a pressure-resistant automatic reactor (hereinafter referred to as the automatic reactor) equipped with a stirrer, temperature controller, pressure gauge, nitrogen inlet pipe, and monomer inlet pipe, 200g of ethylene glycol and 47.62g of KOH were added. The air was replaced with nitrogen. Then, under the conditions of polymerization temperature of 110℃ and maximum reaction pressure of 0.3MPa (standard atmospheric pressure), 32950g of propylene oxide was added in batches (331-400 batches, each batch not exceeding 100g). After the propylene oxide was completely added, the temperature of the automatic reactor was maintained at 110℃-120℃ for 5-7 hours until the reaction was terminated. Then, under the same temperature, the reactor was subjected to reduced pressure at 665kPa for 30 minutes. The air was replaced with nitrogen, and N2 was introduced into the automatic reactor to reach a pressure of 0.1MPa. Then, under the conditions of polymerization temperature of 110℃ and maximum reaction pressure of 0.3MPa (standard atmospheric pressure), 75g of ethylene oxide was added in batches (3-5 batches). After ethylene oxide was completely added, the temperature of the automated reactor was maintained at 110℃-120℃ for 2-3 hours to terminate the reaction. Then, at the same temperature, the mixture was subjected to reduced pressure at 665 kPa for 30 minutes to obtain crude polyether polyol 1#.

[0081] Purification of polyether polyol 1#: 500g of crude polyether polyol 1# is added to an automatic reactor, and 0.89g of phosphoric acid is added as a refining agent at 50℃ for the purification process. The mixture is stirred for 1 hour, and the pH value of the polyether polyol is adjusted to between 5.5 and 6.5. Solid salts are removed by filtration to obtain polyether polyol 1#.

[0082] Comparative Example 2: Preparation of Polyether Polyol 2#

[0083] In a pressure-resistant automatic reactor (hereinafter referred to as the automatic reactor) equipped with a stirrer, temperature controller, pressure gauge, nitrogen inlet pipe, and monomer inlet pipe, 400g of 1,2-propanediol and 103.6g of KOH were added. The air was replaced with nitrogen. Then, under the conditions of polymerization temperature of 130℃ and maximum reaction pressure of 0.4MPa (standard atmospheric pressure), 39000g of propylene oxide was added in batches (400-600 batches, each batch not exceeding 100g). After the propylene oxide was completely added, the temperature of the automatic reactor was maintained at 130℃-135℃ for 5-7 hours until the reaction was terminated. Then, under the same temperature, the reactor was subjected to reduced pressure at 550kPa for 30 minutes. The air was replaced with nitrogen, and N2 was introduced into the automatic reactor to reach a pressure of 0.2MPa. Then, under the conditions of polymerization temperature of 130℃ and maximum reaction pressure of 0.4MPa (standard atmospheric pressure), 50g of ethylene oxide was added in batches (3-5 batches). After ethylene oxide was completely added, the temperature of the automated reactor was maintained at 130℃-135℃ for 2-3 hours to terminate the reaction. Then, at the same temperature, the mixture was subjected to reduced pressure at 550 kPa for 30 minutes to obtain crude polyether polyol 2#.

[0084] Purification of polyether polyol 2#: Add 500g of crude polyether polyol 2# to an automatic reactor, add 1.78g of phosphoric acid and 6g of deionized water at 70℃ and stir for 1h. Adjust the pH value of the polyether polyol to between 5.5 and 6.5, dehydrate until the water content is no more than 0.04%, filter to remove solid salts, and obtain polyether polyol 2#.

[0085] Comparative Example 3: Preparation of Polyether Polyol 3#

[0086] In a pressure-resistant automatic reactor (hereinafter referred to as the automatic reactor) equipped with a stirrer, temperature controller, pressure gauge, nitrogen inlet pipe, and monomer inlet pipe, 300g of glycerol and 48.14g of KOH were added. The air was replaced with nitrogen. Then, under the conditions of polymerization temperature of 120℃ and maximum reaction pressure of 0.4MPa (standard atmospheric pressure), 25900g of propylene oxide was added in batches (260-400 batches, each batch not exceeding 100g). After the propylene oxide was completely added, the temperature of the automatic reactor was maintained at 120℃-130℃ for 5-7 hours until the reaction was terminated. Then, under the same temperature, the reactor was subjected to reduced pressure at 650kPa for 30min. The air was replaced with nitrogen, and N2 was introduced into the automatic reactor to reach a pressure of 0.15MPa. Then, under the conditions of polymerization temperature of 130℃ and maximum reaction pressure of 0.4MPa (standard atmospheric pressure), 50g of ethylene oxide was added in batches (3-5 batches). After ethylene oxide was completely added, the temperature of the automated reactor was maintained at 130℃-135℃ for 2-3 hours to terminate the reaction. Then, at the same temperature, the mixture was subjected to reduced pressure at 650 kPa for 30 minutes to obtain crude polyether polyol 3#.

[0087] Purification of polyether polyol 3#: Add 500g of crude polyether polyol 3# to an automatic reactor, add 1.34g of phosphoric acid and 6g of deionized water at 90℃ and stir for 1h. Adjust the pH of the polyether polyol to between 5.5 and 6.5, dehydrate until the water content is no more than 0.04%, filter to remove solid salts, and obtain polyether polyol 3#.

[0088] Comparative Example 4: Preparation of Polyether Polyol 4#

[0089] In an automated pressure vessel (hereinafter referred to as the "automatic vessel") equipped with a stirrer, temperature controller, pressure gauge, nitrogen inlet pipe, and monomer inlet pipe, 500g of pentaerythritol and 79.8g of KOH were added. The air was replaced with nitrogen. Then, under conditions of polymerization temperature of 115℃ and maximum reaction pressure of 0.25MPa (standard atmospheric pressure), 40900g of propylene oxide was added in batches (410-500 batches, each batch not exceeding 100g). After the propylene oxide was completely added, the temperature of the automatic vessel was maintained at 115℃-120℃ for 5-7 hours until the reaction was terminated. Then, under the same temperature, the vessel was subjected to reduced pressure treatment at 600kPa for 30 minutes. The air was replaced with nitrogen, and N2 was introduced into the automatic vessel to reach a pressure of 0.1MPa. Then, under conditions of polymerization temperature of 130℃ and maximum reaction pressure of 0.35MPa (standard atmospheric pressure), 40g of ethylene oxide was added in batches (3-5 batches). After ethylene oxide was completely added, the temperature of the automated reactor was maintained at 130℃-135℃ for 2-3 hours to terminate the reaction. Then, at the same temperature, the mixture was subjected to reduced pressure at 600 kPa for 30 minutes to obtain crude polyether polyol 4#.

[0090] Purification of polyether polyol 4#: Add 500g of crude polyether polyol 4# to an automatic reactor, add 1.51g of phosphoric acid and 5g of deionized water at 100℃ and stir for 1h. Adjust the pH value of the polyether polyol to between 5.5 and 6.5, dehydrate until the water content is no more than 0.04%, filter to remove solid salts, and obtain polyether polyol 4#.

[0091] Comparative Example 5: Preparation of Polyether Polyol 5#

[0092] In an automated pressure vessel (hereinafter referred to as the "automatic vessel") equipped with a stirrer, temperature controller, pressure gauge, nitrogen inlet pipe, and monomer inlet pipe, 300g of sorbitol and 38.94g of NaH were added. The air was replaced with nitrogen. Then, under conditions of polymerization temperature of 115℃ and maximum reaction pressure of 0.25MPa (standard atmospheric pressure), 5300g of propylene oxide was added in batches (530-600 batches, each batch not exceeding 100g). After the propylene oxide was completely added, the temperature of the automatic vessel was maintained at 115℃-120℃ for 5-7 hours until the reaction was terminated. Then, under the same temperature, the vessel was subjected to reduced pressure treatment at 550kPa for 30 minutes. The air was replaced with nitrogen, and N2 was introduced into the automatic vessel to reach a pressure of 0.1MPa. Then, under conditions of polymerization temperature of 130℃ and maximum reaction pressure of 0.35MPa (standard atmospheric pressure), 128g of ethylene oxide was added in batches (6-10 batches). After ethylene oxide was completely added, the temperature of the automated reactor was maintained at 130℃-135℃ for 2-3 hours to terminate the reaction. Then, at the same temperature, the mixture was subjected to reduced pressure treatment at 550 kPa for 30 minutes to obtain crude polyether polyol 5#.

[0093] Purification of polyether polyol 5#: Add 500g of crude polyether polyol 5# to an automatic reactor, add 1.05g of phosphoric acid and 4g of deionized water at 115℃ and stir for 1h. Adjust the pH value of the polyether polyol to between 5.5 and 6.5, dehydrate until the water content is no more than 0.04%, filter to remove solid salts, and obtain polyether polyol 5#.

[0094] Comparative Example 6: Preparation of Polyether Polyol 6#

[0095] In a pressure-resistant automatic reactor (hereinafter referred to as the automatic reactor) equipped with a stirrer, temperature controller, pressure gauge, nitrogen inlet pipe, and monomer inlet pipe, 342g of sucrose, 62g of ethylene glycol, and 32.06g of NaOH were added. The air was replaced with nitrogen. Then, under the conditions of polymerization temperature of 125℃ and maximum reaction pressure of 0.35MPa (standard atmospheric pressure), 13720g of propylene oxide was added in batches (140-200 batches, each batch not exceeding 100g). After the propylene oxide was completely added, the temperature of the automatic reactor was maintained at 125℃-130℃ for 5-7 hours to terminate the reaction. Then, at the same temperature, the reactor was subjected to reduced pressure at 500kPa for 30 minutes to recover unreacted propylene oxide. The air was replaced with nitrogen, and N2 was introduced into the automated reactor to reach a pressure of 0.17 MPa. Then, under conditions of polymerization temperature of 130℃ and maximum reaction pressure of 0.4 MPa (standard atmospheric pressure), 57 g of ethylene oxide was added in batches (3-5 batches). After the ethylene oxide was completely added, the temperature of the automated reactor was maintained at 130℃-135℃ for 2-3 hours to terminate the reaction. Then, under the same temperature, the mixture was subjected to reduced pressure at 500 kPa for 30 min to obtain crude polyether polyol III.

[0096] Purification of polyether polyol 6#: Add 500g of crude polyether polyol 6# to an automatic reactor, add 2.37g of phosphoric acid and 2g of deionized water at 130℃ and purify for 1 hour. Adjust the pH value of the polyether polyol to between 5.5 and 6.5, dehydrate until the water content is no more than 0.04%, filter to remove solid salts, and obtain polyether polyol 6#.

[0097] The physical properties of polyether polyols are compared in Table 1.

[0098] In the embodiments and comparative examples of this invention:

[0099] The test method for hydroxyl value is: GB / T 12008.3-2009 Plastics Polyether Polyols Part 3: Determination of Hydroxyl Value.

[0100] Table 1. Physical properties of polyether polyols

[0101]

[0102] Note: The odor level test refers to the PV3900 [(Shanghai Volkswagen) Automotive Interior Component Odor Test] method. Five testers conducted blind tests and the average value was taken.

[0103] The odor evaluation criteria are shown in Table 2.

[0104] Table 2 Odor Assessment Criteria

[0105] Fraction Evaluate 1 Odorless 2 It has an odor, but it is not bothersome. 3 It has a distinct odor, but is still not bothersome. 4 It has a disturbing odor 5 It has a strong, interfering odor. 6 It has an unbearable odor.

[0106] It should be noted that the above embodiments only list a few cases, and the preparation of the low-odor, high-activity polyether polyols described in this invention adopts, but is not limited to, the cases listed in the above embodiments. Polyether polyols with hydroxyl values ​​of 8-70 mg KOH / g prepared using alcohols such as butanol, octanol, allyl alcohol, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,3-propanediol, 1,4-cyclohexanediol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, 1,4-cyclohexanediol, glycerol, trimethylolpropane, pentaerythritol, and sorbitol as initiators are all within the scope of protection of this invention.

Claims

1. A method for preparing a polyether polyol, characterized in that: The method includes: Preparation of S1 intermediate 1: Using a small molecule polyol compound as the starting polymer, it is contacted with the first alkali metal catalyst, and one or more epoxy compounds I are added at a temperature of 110-130℃ to prepare intermediate 1 with a hydroxyl value of 55-300 mgKOH / g. Preparation of S2 intermediate 2: Intermediate 1 is contacted with a second alkali metal catalyst and subjected to ring-opening polymerization at a temperature of 110-130°C to generate one or more epoxy compounds II, thereby obtaining intermediate 2 with a hydroxyl value of 20-180 mgKOH / g. Preparation of S3 intermediate 3: Intermediate 2 is contacted with a third alkali metal catalyst, and ring-opening polymerization is carried out at a temperature of 110-130°C to generate one or more epoxy compounds III, thereby obtaining intermediate 3 with a hydroxyl value of 10-100 mgKOH / g. Preparation of S4 polyether polyol: The intermediate 3 is mixed with ethylene oxide, and the intermediate 3 is subjected to ring-opening polymerization of ethylene oxide at a temperature of 100-130°C to obtain a capped product; the method further includes a purification step of the capped product; the purification step includes sequential organic acid treatment and inorganic acid treatment to obtain the polyether polyol.

2. The preparation method according to claim 1, characterized in that: In S1, the mass ratio of the small molecule alcohol compound, the first alkali metal catalyst, and epoxy compound I ranges from 1:0.005 to 0.17:5 to 10. And / or, in S2, the mass ratio of intermediate 1, the second alkali metal catalyst, and epoxide II is in the range of 1:0.003 to 0.1:0.5 to 6; And / or, in S3, the mass ratio of intermediate 2, the third alkali metal catalyst, and epoxide III is in the range of 1:0.002 to 0.1:0.5 to 6; And / or, in S4, the mass ratio of intermediate 3 to ethylene oxide is in the range of 1:0.08 to 0.5; And / or, each of the epoxy compounds I, II, and III is independently selected from at least one of propylene oxide, ethylene oxide, butane oxide, styrene oxide, cyclohexane oxide, epichlorohydrin, bromopropylate, methyl glycidyl ether, and allyl glycidyl ether.

3. The preparation method according to claim 1 or 2, characterized in that: The small molecule polyol compound is selected from at least one of ethylene glycol, 1,2-propanediol, glycerol, pentaerythritol, sorbitol, mannitol, sucrose, glucose, sorbitol, dextrose, levulose, methyl glucoside, and hydroxyethyl glucoside.

4. The preparation method according to claim 1 or 2, characterized in that: The amount of alkali metal catalyst used is a calculated value, and the total mass of alkali metal is 0.078% to 0.26% of the small molecule polyol.

5. The preparation method according to claim 1 or 2, characterized in that: The alkali metal catalyst is selected from at least one of NaOH, KOH, and NaH.

6. The preparation method according to claim 1 or 2, characterized in that: The end-capping treatment is carried out in a nitrogen environment at a pressure of 0.01 MPa to 0.4 MPa.

7. The preparation method according to claim 1 or 2, characterized in that: The organic acid is selected from at least one of cyclopentanoic acid, cyclohexanoic acid, oxalic acid, adipic acid, and cyclohexanoic acid; And / or, the inorganic acid is selected from at least one of phosphoric acid, hydrochloric acid, and sulfuric acid.

8. The preparation method according to claim 7, The organic acid is used to neutralize the alkali metal catalyst in the end-capped product. And / or, the mass ratio of the organic acid to the end-capped product is 1:115 to 440; And / or, the inorganic acid is used to adjust the pH value; the pH is adjusted to 5.2 to 7.

0.

9. The polyether polyol obtained by any one of claims 1-8, characterized in that, The hydroxyl value of the polyether polyol is 8-70 mg KOH / g.

10. The application of the polyether polyol obtained by any one of claims 1-8 or the polyether polyol of claim 9, characterized in that, Used in the preparation of polyurethane or as a lubricant, brake fluid, or resin modifier.

11. The application according to claim 10, characterized in that, The polyurethane is selected from at least one of semi-rigid and flexible polyurethane foams, coatings, adhesives, bedding materials, waterproofing materials, elastomers, sealants, and shoe soles.

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