Preparation method of butane tetracarboxylic acid

Abstract

The invention discloses a preparation method of butanetetracarboxylic acid, which comprises the following steps: hydrolyzing tetrahydrophthalic anhydride under the action of a catalyst, adding calcium ions to react, adding an oxidant to oxidize, acidizing with sulfuric acid, filtering to remove calcium sulfate, and purifying to obtain butanetetracarboxylic acid. The method has the advantages of simple operation steps, mild reaction conditions, short reaction time, high product yield, high quality, good performance and good environmental benefits, and can be used for preparing butane tetracarboxylic acid with high purity.

Description

Technical Field

[0001] The present invention relates to the technical field of new material chemical industry, and particularly to a preparation method of butane tetracarboxylic acid (BTCA). Background Art

[0002] Butane tetracarboxylic acid (BTCA) is an important chemical product and is used as a formaldehyde-free durable press finishing agent in the textile industry. Practical applications show that fabrics finished with BTCA have excellent properties such as high drying self-flattening, wrinkle resistance, dimensional stability, non-yellowing, formaldehyde-free finishing, low toxicity, and re-recovery. In addition, butane tetracarboxylic acid (BTCA) can also be used as an activator in cosmetics. With the innovation of technology, butane tetracarboxylic acid (BTCA) has become the main raw material of polyimide (PI) organic polymer materials. This new material is famous for its excellent high-temperature resistance, electrical insulation, wear resistance, high-temperature radiation resistance, and physical and mechanical properties. Due to its unique comprehensive properties, PI materials have been widely used in fields such as aviation, aerospace, microelectronics, nanotechnology, liquid crystals, separation membranes, and lasers. Especially in high-end technology fields such as rockets and aerospace, PI materials have become one of the indispensable materials. In addition, after adding glass fibers, graphite, and boron fibers to PI, higher hardness and strength can be obtained, and it can replace metals to manufacture jet engine structural components. PI resin filled with graphite or polytetrafluoroethylene (PTFE) can be used as a self-lubricating material, and after adding wear-resistant fillers, it can be used to manufacture high-temperature resistant brake pads, etc.

[0003] Chinese Patent Application No. 201110193138.4 discloses a preparation method of butane tetracarboxylic acid. This method has a relatively high reaction temperature, a relatively long reaction time, and relatively strict requirements for reaction equipment. Summary of the Invention

[0004] To solve the problems existing in the prior art, the present invention provides a preparation method of butane tetracarboxylic acid (BTCA). The operation steps of this method are simple, the reaction conditions are mild, and the reaction time is relatively short. Through this method, butane tetracarboxylic acid (BTCA) with relatively high purity can be prepared, and the product has high yield, high quality, good performance, and good environmental benefits.

[0005] To achieve the above object, the present invention adopts the following technical scheme: A preparation method of butane tetracarboxylic acid, comprising the following steps: (1) Hydrolyze tetrahydrophthalic anhydride under the action of a catalyst to obtain an aqueous solution of 4-cyclohexene-1,2-dicarboxylic acid; (2) Add calcium ions to the aqueous solution of 4-cyclohexene-1,2-dicarboxylic acid, and react to obtain an aqueous solution of calcium 4-cyclohexene-1,2-dicarboxylate; (3) Add an oxidizing agent to the aqueous solution of calcium 4-cyclohexene-1,2-dicarboxylate and react at 70-80 °C to obtain an aqueous solution of calcium butanetetracarboxylate; (4) Add sulfuric acid to acidify the aqueous solution of calcium butanetetracarboxylate, then filter to remove calcium sulfate to obtain an aqueous solution of butanetetracarboxylic acid, and then purify it to obtain butanetetracarboxylic acid.

[0006] Preferably, the catalyst in step (1) is tungstic acid.

[0007] Preferably, the weight ratio of tetrahydrophthalic anhydride to water in step (1) is 1:4 to 4.5.

[0008] Preferably, the reaction temperature in step (1) is 50-60 °C.

[0009] Preferably, the weight ratio of tetrahydrophthalic anhydride to the catalyst in step (1) is 1:0.03 to 0.05.

[0010] Preferably, the calcium ion in step (2) is derived from calcium carbonate.

[0011] Preferably, the reaction temperature in step (2) is 50-60 °C.

[0012] Preferably, step (2) further includes the step of adjusting the pH of the system to 3.5-4.5.

[0013] Preferably, the oxidizing agent in step (3) is hydrogen peroxide. More preferably, the concentration of the hydrogen peroxide is 30%wt-50%wt.

[0014] Preferably, the reaction temperature in step (3) is 70-80 °C.

[0015] Preferably, the weight ratio of the oxidizing agent in step (3) to the tetrahydrophthalic anhydride in step (1) is 0.9-1.9:1.

[0016] Preferably, the sulfuric acid in step (4) has a concentration of 98%wt.

[0017] Preferably, the acidification temperature in step (4) is 30-40 °C.

[0018] Preferably, the pH of the acidification in step (4) is 2.0-3.0.

[0019] Preferably, the purification in step (4) includes the steps of concentration, cooling, crystallization, centrifugation, and drying.

[0020] Preferably, the conditions for the concentration are 70-85 °C and a vacuum degree of -0.09 to -0.095 MPa.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention provides a new method for preparing butanetetracarboxylic acid (BTCA) by a green process. The operation steps of this method are simple, the raw materials are easily available, the reaction conditions are mild, the reaction time is short. By this method, a butanetetracarboxylic acid (BTCA) product with high purity can be prepared, with a high yield, good performance, low equipment requirements, and good environmental benefits. Description of the Drawings

[0022] Figure 1 It is the chromatogram of the purified product obtained in Example 3.

[0023] Figure 2 It is the chromatogram of the purified product obtained in the comparative example. Detailed Embodiments

[0024] The present invention will be further described below through examples, but is not limited to the following content.

[0025] Example 1 Add 1 kg of tetrahydrophthalic anhydride and 4 kg of deionized water to the reaction kettle, stir evenly, add 30 g of tungstic acid, react at 50 °C for 0.5 hour, slowly add calcium carbonate, adjust the pH of the reaction solution to 3.5, then continue stirring for 0.5 hour, slowly pump 3.8 kg of 30% hydrogen peroxide into the reaction kettle with a metering pump, the pumping time is 4 hours, heat up to 70 °C, keep the temperature for reaction until the hydrogen peroxide < 0.3 mol / L, end the reaction, and detect that the purity of the reaction solution is 81.12%. Cool to 30 °C, measure and add sulfuric acid, adjust the pH of the reaction solution to 2.0, and then filter to remove calcium salts. The aqueous solution of BTCA semi-finished product is reacted, concentrated, cooled, crystallized, centrifuged, and dried at 70 °C and a vacuum degree of -0.090 MPa to obtain 1.43 kg of butanetetracarboxylic acid (BTCA), with a yield of 93.18% and a purity of 98.10%.

[0026] Example 2 Add 1 kg of tetrahydrophthalic anhydride and 4 kg of deionized water to the reaction kettle, stir evenly, add 40 g of tungstic acid, react at 50 °C for 0.5 hour, slowly add calcium carbonate, adjust the pH of the reaction solution to 3.5, then continue stirring for 0.5 hour, slowly pump 3.8 kg of 30% hydrogen peroxide into the reaction kettle with a metering pump, the pumping time is 4 hours, heat up to 70 °C, keep the temperature for reaction until the hydrogen peroxide < 0.3 mol / L, end the reaction, and detect that the purity of the reaction solution is 80.59%. Cool to 30 °C, measure and add sulfuric acid, adjust the pH of the reaction solution to 2.0, and then filter to remove calcium salts. The aqueous solution of BTCA semi-finished product is reacted, concentrated, cooled, crystallized, centrifuged, and dried at 70 °C and a vacuum degree of -0.090 MPa to obtain 1.47 kg of butanetetracarboxylic acid (BTCA), with a yield of 95.57% and a purity of 98.50%.

[0027] Example 3 Add 1 kg of tetrahydrophthalic anhydride and 4 kg of deionized water to the reaction kettle, stir evenly, add 50 g of tungstic acid, react for 0.5 hour under the condition of 50 °C, slowly add calcium carbonate, adjust the pH of the reaction solution to 3.5, then continue to stir for 0.5 hour, slowly meteringly pump 3.8 kg of 30% hydrogen peroxide into the reaction kettle through a metering pump, the pumping time is 4 hours, raise the temperature to 70 °C, keep the temperature for reaction until the hydrogen peroxide < 0.3 mol / L, end the reaction, and detect that the purity of the reaction solution is 82.38%. Cool to 30 °C, meteringly add sulfuric acid, adjust the pH of the reaction solution to 2.0, and then filter to remove calcium salts. The semi-finished BTCA aqueous solution is reacted, concentrated, cooled, crystallized, centrifuged, and dried under the conditions of 70 °C and a vacuum degree of -0.090 MPa to obtain 1.53 kg of butanetetracarboxylic acid (BTCA), with a yield of 99.14% and a purity of 99.31%, as Figure 1 shown.

[0028] Example 4 Add 1 kg of tetrahydrophthalic anhydride and 4 kg of deionized water to the reaction kettle, stir evenly, add 30 g of tungstic acid, react for 0.5 hour under the condition of 60 °C, slowly add calcium carbonate, adjust the pH of the reaction solution to 4.5, then continue to stir for 0.5 hour, slowly meteringly pump 3.8 kg of 30% hydrogen peroxide into the reaction kettle through a metering pump, the pumping time is 4 hours, raise the temperature to 80 °C, keep the temperature for reaction until the hydrogen peroxide < 0.3 mol / L, end the reaction, and detect that the purity of the reaction solution is 80.38%. Cool to 40 °C, meteringly add sulfuric acid, adjust the pH of the reaction solution to 2.5, and then filter to remove calcium salts. The semi-finished BTCA aqueous solution is reacted, concentrated, cooled, crystallized, centrifuged, and dried under the conditions of 80 °C and a vacuum degree of -0.095 MPa to obtain 1.47 kg of butanetetracarboxylic acid (BTCA), with a yield of 96.08% and a purity of 98.03%.

[0029] Example 5 Add 1 kg of tetrahydrophthalic anhydride and 4 kg of deionized water to the reaction kettle, stir evenly, add 30 g of tungstic acid, react for 0.5 hour under the condition of 60 °C, slowly add calcium carbonate, adjust the pH of the reaction solution to 4.0, then continue to stir for 0.5 hour, slowly meteringly pump 3 kg of 30% hydrogen peroxide into the reaction kettle through a metering pump, the pumping time is 4 hours, raise the temperature to 80 °C, keep the temperature for reaction until the hydrogen peroxide < 0.3 mol / L, end the reaction, and detect that the purity of the reaction solution is 81.15%. Cool to 30 °C, meteringly add sulfuric acid, adjust the pH of the reaction solution to 2.5, and then filter to remove calcium salts. The semi-finished BTCA aqueous solution is reacted, concentrated, cooled, crystallized, centrifuged, and dried under the conditions of 80 °C and a vacuum degree of -0.095 MPa to obtain 1.48 kg of butanetetracarboxylic acid (BTCA), with a yield of 96.22% and a purity of 98.77%.

[0030] Example 6 Add 1 kg of tetrahydrophthalic anhydride and 4 kg of deionized water to the reaction kettle, stir evenly, add 40 g of tungstic acid, react at 60 °C for 0.5 hour, slowly add calcium carbonate, adjust the pH of the reaction solution to 4.0, then continue stirring for 0.5 hour, slowly meteringly pump 3 kg of 50% hydrogen peroxide into the reaction kettle over 4 hours, raise the temperature to 80 °C, keep the temperature for reaction until the hydrogen peroxide is < 0.3 mol / L, end the reaction, and detect that the purity of the reaction solution is 80.95%. Cool to 30 °C, meteringly add sulfuric acid, adjust the pH of the reaction solution to 2.5, and then filter to remove calcium salts. The semi-finished BTCA aqueous solution is reacted, concentrated, cooled, crystallized, centrifuged, and dried at 80 °C and a vacuum of -0.095 MPa to obtain 1.46 kg of butanetetracarboxylic acid (BTCA), with a yield of 95.23% and a purity of 98.47%.

[0031] Example 7 Add 1 kg of tetrahydrophthalic anhydride and 4 kg of deionized water to the reaction kettle, stir evenly, add 50 g of tungstic acid, react at 60 °C for 0.5 hour, slowly add calcium carbonate, adjust the pH of the reaction solution to 4.0, then continue stirring for 0.5 hour, slowly meteringly pump 3 kg of 50% hydrogen peroxide into the reaction kettle over 4 hours, raise the temperature to 80 °C, keep the temperature for reaction until the hydrogen peroxide is < 0.3 mol / L, end the reaction, and detect that the purity of the reaction solution is 82.59%. Cool to 30 °C, meteringly add sulfuric acid, adjust the pH of the reaction solution to 3.0, and then filter to remove calcium salts. The semi-finished BTCA aqueous solution is reacted, concentrated, cooled, crystallized, centrifuged, and dried at 80 °C and a vacuum of -0.095 MPa to obtain 1.49 kg of butanetetracarboxylic acid (BTCA), with a yield of 97.34% and a purity of 98.57%.

[0032] Example 8 Add 1 kg of tetrahydrophthalic anhydride and 4.5 kg of deionized water to the reaction kettle, stir evenly, add 30 g of tungstic acid, react at 60 °C for 0.5 hour, slowly add calcium carbonate, adjust the pH of the reaction solution to 4.5, then continue stirring for 0.5 hour, slowly meteringly pump 3 kg of 50% hydrogen peroxide into the reaction kettle over 4 hours, raise the temperature to 80 °C, keep the temperature for reaction until the hydrogen peroxide is < 0.3 mol / L, end the reaction, and detect that the purity of the reaction solution is 80.06%. Cool to 30 °C, meteringly add sulfuric acid, adjust the pH of the reaction solution to 3.0, and then filter to remove calcium salts. The semi-finished BTCA aqueous solution is reacted, concentrated, cooled, crystallized, centrifuged, and dried at 80 °C and a vacuum of -0.095 MPa to obtain 1.46 kg of butanetetracarboxylic acid (BTCA), with a yield of 95.36% and a purity of 98.13%.

[0033] Example 9 Add 1 kg of tetrahydrophthalic anhydride and 4.5 kg of deionized water to the reaction kettle, stir evenly, add 40 g of tungstic acid, react at 60 °C for 0.5 hour, slowly add calcium carbonate, adjust the pH of the reaction solution to 4.5, then continue stirring for 0.5 hour, slowly meteringly pump 3 kg of 50% hydrogen peroxide into the reaction kettle over 4 hours, heat up to 80 °C, keep the temperature for reaction until the hydrogen peroxide content is < 0.3 mol / L, end the reaction, and detect that the purity of the reaction solution is 82.01%. Cool to 30 °C, meteringly add sulfuric acid, adjust the pH of the reaction solution to 3.0, and then filter to remove calcium salts. The semi-finished BTCA aqueous solution is reacted for concentration, cooling, crystallization, centrifugation, and drying under the conditions of 80 °C and a vacuum degree of -0.095 MPa to obtain 1.49 kg of butanetetracarboxylic acid (BTCA), with a yield of 97.11% and a purity of 98.33%.

[0034] Example 10 Add 1 kg of tetrahydrophthalic anhydride and 4.5 kg of deionized water to the reaction kettle, stir evenly, add 50 g of tungstic acid, react at 60 °C for 0.5 hour, slowly add calcium carbonate, adjust the pH of the reaction solution to 4.5, then continue stirring for 0.5 hour, slowly meteringly pump 3 kg of 50% hydrogen peroxide into the reaction kettle over 4 hours, heat up to 80 °C, keep the temperature for reaction until the hydrogen peroxide content is < 0.3 mol / L, end the reaction, and detect that the purity of the reaction solution is 81.95%. Cool to 30 °C, meteringly add sulfuric acid, adjust the pH of the reaction solution to 3.0, and then filter to remove calcium salts. The semi-finished BTCA aqueous solution is reacted for concentration, cooling, crystallization, centrifugation, and drying under the conditions of 80 °C and a vacuum degree of -0.095 MPa to obtain 1.51 kg of butanetetracarboxylic acid (BTCA), with a yield of 98.22% and a purity of 99.00%.

[0035] Add 1 kg of tetrahydrophthalic anhydride and 4.5 kg of deionized water to the reaction kettle, stir evenly, add 50 g of tungstic acid, react at 80 °C for 0.5 hour, heat up to 85 - 90 °C, keep the temperature for 0.5 hour, slowly meteringly pump 3 kg of 50% hydrogen peroxide into the reaction kettle over 12 - 16 hours, control the temperature at 85 - 90 °C, keep the temperature for reaction until the hydrogen peroxide content is < 0.3 mol / L, end the reaction, and detect that the purity of the reaction solution is 69.80%. Cool to 30 °C, and the semi-finished BTCA aqueous solution is reacted for concentration, cooling, crystallization, centrifugation, and drying under the conditions of 80 °C and a vacuum degree of -0.095 MPa to obtain 1.26 kg of butanetetracarboxylic acid (BTCA), with a yield of 82.08% and a purity of 95.23%, as Figure 2 shown.

[0036] By comparison, it can be seen that in the present invention, by adding calcium ions, while adjusting the pH of the reaction solution, the activity of the catalyst is improved, the reaction temperature is reduced, and the purity after the reaction ends is higher than that of the prior art.

Claims

1. A method for preparing butane tetracarboxylic acid, characterized in that, It includes the following steps: (1) Hydrolyze tetrahydrophthalic anhydride under the action of a catalyst to obtain an aqueous solution of 4-cyclohexene-1,2-dicarboxylic acid; (2) Add calcium ions to the aqueous solution of 4-cyclohexene-1,2-dicarboxylic acid, and react to obtain an aqueous solution of calcium 4-cyclohexene-1,2-dicarboxylate; (3) Add an oxidant to the aqueous solution of calcium 4-cyclohexene-1,2-dicarboxylate, and react at 70-80 °C to obtain an aqueous solution of calcium butanetetracarboxylate; (4) Acidify the aqueous solution of calcium butanetetracarboxylate with sulfuric acid, then filter to remove calcium sulfate to obtain an aqueous solution of butanetetracarboxylic acid, and then purify to obtain butanetetracarboxylic acid.

2. The preparation method according to claim 1, characterized in that, The catalyst described in step (1) is tungstic acid.

3. The preparation method according to claim 1, characterized in that, The weight ratio of tetrahydrophthalic anhydride to water described in step (1) is 1:4-4.

5.

4. The preparation method according to claim 1, characterized in that, The calcium ions described in step (2) are derived from calcium carbonate.

5. The preparation method according to claim 1, characterized in that, The reaction temperature described in step (2) is 50-60 °C.

6. The preparation method according to claim 1, characterized in that, Step (2) also includes the step of adjusting the pH of the system to 3.5-4.

5.

7. The preparation method according to claim 1, wherein The oxidant described in step (3) is hydrogen peroxide; preferably, the concentration of the hydrogen peroxide is 30%wt-50%wt.

8. The preparation method according to claim 1, characterized in that, The reaction temperature described in step (3) is 70-80 °C.

9. The preparation method according to claim 1, wherein The weight ratio of the oxidant described in step (3) to the tetrahydrophthalic anhydride described in step (1) is 0.9-1.9:

1.

10. The preparation method according to claim 1, characterized in that, The pH of the acidification described in step (4) is 2.0-3.0.

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