Preparation method of narrow-distribution low-color-number bisphenol a polyoxyethylene ether

Abstract

The present application relates to a kind of preparation methods of narrow distribution low color number bisphenol A polyoxyethylene ether.The high-pressure resistant reaction kettle is added with bisphenol A, antioxidant and low activity catalyst, oxygen is removed under nitrogen protection, heated to 50-80 DEG C, first a small amount of ethylene oxide is added, then a small amount of ethylene oxide is slowly added under the condition that pressure is not more than 0.3MPa, bisphenol A is melted or melted, and then stirred at 100-140 DEG C to be aged until pressure does not decrease again;The reaction kettle is cooled, high activity catalyst is added, the reaction kettle is sealed, oxygen is removed under nitrogen protection, heated to 100-140 DEG C, gradually add the remaining ethylene oxide under the condition that pressure is not more than 0.5MPa, and 100-140 DEG C is aged;The reaction kettle is cooled, the pH of reaction system is adjusted to weak acid, and then treated after adding adsorbent, filtration.The raw material of the preparation method is simple and easy to obtain, the reaction temperature is low, the product quality is stable, and it is beneficial to the synthesis and application of downstream UV photocuring monomer.

Description

Technical Field

[0001] This invention belongs to the field of chemical synthesis, specifically relating to a method for preparing narrow-distribution, low-color-number bisphenol A polyoxyethylene ether. Background Technology

[0002] Bisphenol A polyoxyethylene ether is mainly prepared by the addition reaction of bisphenol A with ethylene oxide under the action of different types of catalysts.

[0003] Bisphenol A polyoxyethylene ether is a polymer with different numbers of epoxy additions, and the properties of the product vary depending on the number of epoxy additions. Traditional preparation processes require the addition of solvents or products to promote the melting of bisphenol A, which leads to a wide and unstable molecular weight distribution. The molecular weight distribution of bisphenol A polyoxyethylene ether affects the synthesis and use of downstream products. Bisphenol A polyoxyethylene ether with a narrow molecular weight distribution has advantages such as fewer by-products, better quality stability, and better application performance.

[0004] Bisphenol A has a melting point of 158℃. Traditional bisphenol A polyoxyethylene ether synthesis processes typically involve first heating bisphenol A, then reacting the melted bisphenol A with ethylene oxide and a catalyst. This process is lengthy and easily leads to product discoloration. Dark-colored bisphenol A polyoxyethylene ether significantly impacts downstream applications such as the synthesis of UV-curable monomers and the use of pre-toughening agents, severely reducing product quality. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of traditional preparation processes and to propose a method for preparing bisphenol A polyoxyethylene ether with low color number and narrow distribution.

[0006] The technical solution adopted in this invention is as follows: A method for preparing narrow-distribution, low-color-number bisphenol A polyoxyethylene ether, comprising the following steps:

[0007] 1) In a high-pressure reactor, add bisphenol A, antioxidant and low-activity catalyst, remove oxygen and heat to 50-80℃ under nitrogen protection. First add 1-10% ethylene oxide by weight of bisphenol A, then continue heating to 100-140℃, controlling the pressure to not exceed 0.3MPa. During the heating process, slowly add 10-30% ethylene oxide by weight of bisphenol A to melt or fused the system. Then start stirring and age at 100-140℃ for 4-8 hours until the reaction is complete and the pressure no longer decreases.

[0008] 2) Cool the reactor to 60-100℃, discharge to atmospheric pressure, quickly add a highly active catalyst, then quickly seal the reactor again to remove oxygen and, under nitrogen protection, raise the temperature to 100-140℃, controlling the pressure to not exceed 0.5MPa, gradually add the remaining ethylene oxide, and age the reaction for 1-4 hours until the pressure no longer decreases.

[0009] 3) Cool down and depressurize the reactor, adjust the pH of the reaction system to acidic, add adsorbent, and perform post-treatment with or without filter aid, then filter and discharge the material.

[0010] Furthermore, in the above-mentioned method for preparing a narrow-distribution, low-color-number bisphenol A polyoxyethylene ether, the antioxidant is selected from one, two, or three of potassium borohydride, sodium borohydride, and 2,6-di-tert-butyl-p-cresol.

[0011] Furthermore, in the above-mentioned method for preparing a narrow-distribution, low-color-number bisphenol A polyoxyethylene ether, the low-activity catalyst is selected from one, two, or three of sodium carbonate, potassium carbonate, and tetramethylammonium hydroxide.

[0012] Furthermore, in the above-mentioned method for preparing a narrow-distribution, low-color-number bisphenol A polyoxyethylene ether, the highly active catalyst is selected from one, two, or three of potassium hydroxide, sodium hydroxide, and triethylamine.

[0013] Furthermore, in the above-mentioned method for preparing a narrow-distribution, low-color-number bisphenol A polyoxyethylene ether, in step 3), the pH of the reaction system is adjusted to 4.0-6.5 using phosphoric acid or acetic acid.

[0014] Furthermore, in the above-mentioned method for preparing a narrow-distribution, low-color-number bisphenol A polyoxyethylene ether, the adsorbent is selected from magnesium aluminum silicate.

[0015] Furthermore, in the above-mentioned method for preparing a narrow-distribution, low-color-number bisphenol A polyoxyethylene ether, the filter aid is selected from activated clay and / or diatomaceous earth.

[0016] The beneficial effects of this invention are:

[0017] 1. This invention lowers the melting point of the system by pre-addition of ethylene oxide, while adding antioxidants ensures the color of the product. The absence of solvent addition and pre-reaction ensures the narrow distribution of the product.

[0018] 2. The narrow-distribution, low-color-number bisphenol A polyoxyethylene ether product prepared by this invention has an average molar molecular weight component accounting for more than 80%, and a low color number, which is recorded as a platinum-cobalt color number between 10 and 40#.

[0019] 3. The narrow-distribution, low-color-number bisphenol A polyoxyethylene ether product prepared by this invention uses simple and readily available raw materials, has a low reaction temperature, and stable product quality, which is beneficial to the synthesis and application of downstream UV-curable monomers. Detailed Implementation

[0020] The following embodiments are used to further illustrate the present invention, but are not intended to limit the present invention.

[0021] Example 1 Bisphenol A polyoxyethylene (2) ether

[0022] The preparation method is as follows:

[0023] 1. Add 456g of bisphenol A, 0.05g of potassium borohydride, and 0.3g of sodium carbonate to a high-pressure reactor. After purging with nitrogen five times, measure the residual oxygen content in the reactor to be <100ppm. Then, seal the reactor and heat it to 50℃. Slowly add 10g of ethylene oxide, and then heat it to gradually increase the temperature to 105℃, controlling the pressure to not exceed 0.3MPa. During the heating process, slowly add 80g of ethylene oxide to melt or fused the system. Then, start stirring intermittently and age it at 100-110℃ for 5 hours until the reaction is complete and the pressure does not drop.

[0024] 2. Cool the reactor to 70-80℃, discharge to normal pressure, quickly add 0.3g of potassium hydroxide, and quickly seal the reactor again. Start stirring, purge with nitrogen 5 times to remove oxygen, and under nitrogen protection, heat to 100-110℃ in a sealed manner. After controlling the pressure to not exceed 0.5MPa, gradually add 96g of ethylene oxide and react for 0.5h. Then, age at 100-110℃ for 1h with stirring until the pressure does not drop.

[0025] 3. After the reaction vessel is cooled down to 70-80℃ again, the reaction product is transferred to a four-necked flask. The pH of the reaction system is adjusted to 5.5 with 80% phosphoric acid. Then, 2g of magnesium aluminum silicate is added, and the mixture is stirred at 80-90℃ for 0.5h. The mixture is then filtered to obtain a colorless and transparent liquid.

[0026] Example 2 Bisphenol A polyoxyethylene (4) ether

[0027] The preparation method is as follows:

[0028] 1. Add 456g of bisphenol A, 0.05g of 2,6-di-tert-butyl-p-cresol, and 0.4g of potassium carbonate to a high-pressure reactor. After purging with nitrogen five times, measure the residual oxygen content in the reactor to be <100ppm. Then, seal the reactor and raise the temperature to 60℃. Slowly add 10g of ethylene oxide, and then heat the reactor to gradually raise the temperature to 105℃, controlling the pressure to not exceed 0.3MPa. During the heating process, slowly add 70g of ethylene oxide to melt or fused the system. Then, start stirring intermittently and continue aging at 110-120℃ for 6 hours until the reaction is complete and the pressure does not drop.

[0029] 2. Cool the reactor to 70-80℃, release to atmospheric pressure, quickly add 0.5g sodium hydroxide, and quickly seal the reactor again. Start stirring, purge with nitrogen 5 times to remove oxygen, and under nitrogen protection, heat to 100-120℃ in a sealed manner. After controlling the pressure to not exceed 0.5MPa, gradually add 282g ethylene oxide and react for 1 hour. Then, age at 110-120℃ for 1.5 hours with stirring until the pressure does not drop.

[0030] 3. After the reaction vessel is cooled down to 70-80℃ again, the reaction product is transferred to a four-necked flask. The pH of the reaction system is adjusted to 5.5 with 80% phosphoric acid. Then, 2g of magnesium aluminum silicate is added, and the mixture is stirred at 70-80℃ for 0.5h. The mixture is then filtered to obtain a colorless and transparent liquid.

[0031] Example 3: Bisphenol A polyoxyethylene (10) ether

[0032] The preparation method is as follows:

[0033] 1. In a high-pressure reactor, add 342g of bisphenol A, 0.05g of sodium borohydride, and 0.3g of sodium carbonate. After purging with nitrogen five times, measure the residual oxygen content in the reactor to be <100ppm. Then, seal the reactor and heat it to 60℃. Slowly add 10g of ethylene oxide, and then heat it to gradually increase the temperature to 105℃, controlling the pressure to not exceed 0.3MPa. During the heating process, slowly add 85g of ethylene oxide to melt or fused the system. Then, start stirring and continue aging at 120-130℃ for 6 hours until the reaction is complete and the pressure does not drop.

[0034] 2. Cool the reactor to 70-80℃, discharge to normal pressure, quickly add 0.5g of potassium hydroxide, and quickly seal the reactor again. Start stirring, purge with nitrogen 5 times to remove oxygen, and under nitrogen protection, heat to 110-130℃ in a sealed manner. After controlling the pressure to not exceed 0.5MPa, gradually add 575g of ethylene oxide and react for 1.5h. Then, age at 120-130℃ for 2h with stirring until the pressure does not drop.

[0035] 3. After the material in the reactor is cooled to 70-80℃, the reaction product is transferred to a four-necked flask. The pH of the reaction system is adjusted to 6.0 with anhydrous acetic acid. 2.5g of magnesium aluminum silicate is added, and the mixture is stirred at 70-80℃ for 0.5h. The mixture is then filtered to obtain a colorless and transparent liquid. Comparative Example 1: Bisphenol A polyoxyethylene (10) ether

[0036] The preparation method is as follows:

[0037] 1. Add 342g of bisphenol A, 100g of bisphenol A polyoxyethylene (10) ether, and 0.7g of sodium hydroxide to a high-pressure reactor. After purging with nitrogen five times, the residual oxygen content in the reactor is measured to be <100ppm. Then, seal the reactor and heat it to 120℃ and maintain it for 6 hours. After jogging, start stirring and control the pressure to not exceed 0.5MPa and the temperature to 120-130℃. Gradually and slowly add a total of 660g of ethylene oxide and react for 3 hours. Then, start stirring and continue aging at 120-130℃ for 1.5 hours until the pressure does not drop.

[0038] 2. Cool the reaction vessel to 70-80℃, transfer the reaction product to a four-necked flask, add 80% phosphoric acid to adjust the pH to 6.0, add 2.5g of magnesium aluminum silicate, stir at 70-80℃ for 0.5h, filter and discharge to obtain a yellow transparent liquid.

[0039] Example 4

[0040] The bisphenol A polyoxyethylene ethers prepared in Examples 1-3 and Comparative Example 1 were tested, and the specific indicators are shown in the table below:

[0041] Table 1

[0042] Serial Number Average number of added moles Average mole array percentage Platinum Cobalt Color Example 1 2 87.8 20# Example 2 4 85.2 30# Example 3 10 80.6 40# Comparative Example 1 10 51.3 150#

[0043] The higher the average mole array percentage in Table 1, the narrower the distribution. As can be seen from Table 1, the average mole array percentage in the examples is all above 80%, which is significantly higher than that in the comparative examples.

Claims

1. A method for preparing a narrow distribution low color bisphenol A polyoxyethylene ether, characterized by, The preparation method comprises the following steps: 1) in a high-pressure resistant reaction kettle, add bisphenol A, antioxidant and low-activity catalyst, deoxygenate and heat to 50-80℃ under nitrogen protection, first add 1-10% of the weight of bisphenol A of ethylene oxide, then continue to heat to 100-140℃, control the pressure not to exceed 0.3 MPa, slowly add 10-30% of the weight of bisphenol A of ethylene oxide to melt or fuse the system during the heating process, then open the stirring and age at 100-140℃ for 4-8h until the reaction is complete and the pressure no longer decreases; 2) cool the reaction kettle to 60-100℃, discharge to normal pressure, quickly add high-activity catalyst, then quickly close the reaction kettle again, deoxygenate and heat to 100-140℃ under nitrogen protection, control the pressure not to exceed 0.5 MPa, gradually add the remaining ethylene oxide, and age for 1-4h until the pressure no longer decreases; 3) cool the reaction kettle and discharge the pressure, adjust the pH of the reaction system to be acidic, add adsorbent, add or do not add filter aid for post-treatment, and filter the discharge; The antioxidant is selected from one or two or three of potassium borohydride, sodium borohydride and 2,6-p-di-tert-butyl-p-cresol; The low-activity catalyst is selected from one or two or three of sodium carbonate, potassium carbonate and tetramethylammonium hydroxide; The high-activity catalyst is selected from one or two or three of potassium hydroxide, sodium hydroxide and triethylamine; In step 3), phosphoric acid or acetic acid is used to adjust the pH of the reaction system to be 4.0-6.5; The adsorbent is selected from magnesium aluminum silicate; The filter aid is selected from activated clay and / or diatomite.