CN114349727A - Method for reducing acetic acid residue in synthesis of 3,3 ', 4, 4' -diphenyl ether dianhydride - Google Patents
Method for reducing acetic acid residue in synthesis of 3,3 ', 4, 4' -diphenyl ether dianhydride Download PDFInfo
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Abstract
本发明涉及提纯除杂技术领域，具体公开一种降低3,3’,4,4’‑二苯醚二酐合成中醋酸残留的方法。所述包括以下步骤：将3,3’,4,4’‑二苯醚四甲酸粗品精制得到3,3’,4,4’‑二苯醚四甲酸精制湿品；将所述3,3’,4,4’‑二苯醚四甲酸精制湿品经减压烘干、粉碎，至其堆积密度≤0.4g/cm3，得3,3’,4,4’‑二苯醚四甲酸精制干品；将所述3,3’,4,4’‑二苯醚四甲酸精制干品经醋酐脱水，减压烘干，得3,3’,4,4’‑二苯醚二酐。本发明通过控制粗品的精制以及降温析晶的条件使得3,3’,4,4’‑二苯醚四甲酸的堆积密度≤0.4g/cm3，进而实现将产品中的醋酸残留降至0.2%以下。
The invention relates to the technical field of purification and impurity removal, and specifically discloses a method for reducing acetic acid residues in the synthesis of 3,3',4,4'-diphenyl ether dianhydride. The process includes the following steps: purifying the crude product of 3,3',4,4'-diphenyl ether tetracarboxylic acid to obtain a 3,3',4,4'-diphenyl ether tetracarboxylic acid refined wet product; ',4,4'-diphenyl ether tetracarboxylic acid refined wet product is dried under reduced pressure and pulverized until its bulk density ≤ 0.4g/cm 3 , to obtain 3,3',4,4'-diphenyl ether tetracarboxylic acid Refined dry product; dehydrate the 3,3',4,4'-diphenyl ether tetracarboxylic acid refined dry product through acetic anhydride, and dry under reduced pressure to obtain 3,3',4,4'-diphenyl ether diphenyl ether anhydride. The present invention controls the refining of the crude product and the conditions for cooling and crystallization so that the bulk density of 3,3',4,4'-diphenyl ether tetracarboxylic acid is less than or equal to 0.4g/cm 3 , thereby reducing the acetic acid residue in the product to 0.2 %the following.
Description
Technical Field
The invention relates to the technical field of purification and impurity removal, in particular to a method for reducing acetic acid residue in synthesis of 3,3 ', 4, 4' -diphenyl ether dianhydride.
Background
3,3 ', 4, 4' -diphenyl ether dianhydride is an important monomer for synthesizing polyimide, and the polyimide synthesized by using the dianhydride as a raw material has excellent hot processing performance, high temperature resistance of over 400 ℃ and high insulating performance. With the development of digitalization, intellectualization and touch screen, the usage amount of polyimide as a high-end electronic material for display screens is rapidly increasing, and thus, the demand amount of 3,3 ', 4, 4' -diphenyl ether dianhydride is rapidly increasing.
The 3,3 ', 4, 4' -diphenyl ether dianhydride is usually obtained by performing an acetic anhydride dehydration process on 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid, and in the reaction process, a product has obvious sour taste and affects the quality of the product, so that acetic acid residue is one of important indexes of the product quality, and the index of the acetic acid residue is required to be below 0.5%. At present, residual acetic acid is mainly removed by a reduced pressure drying mode, but the method has poor purification effect on 3,3 ', 4, 4' -diphenyl ether dianhydride, and the content of the residual acetic acid is difficult to be reduced to be less than 0.5%, so that the method for reducing the residual acetic acid is found to be of great significance for obtaining high-purity 3,3 ', 4, 4' -diphenyl ether dianhydride and synthesizing polyimide by using high-purity 3,3 ', 4, 4' -diphenyl ether dianhydride.
Disclosure of Invention
In view of the above, the present application provides a method for reducing acetic acid residue in the synthesis of 3,3 ', 4, 4' -diphenyl ether dianhydride, wherein the bulk density is less than or equal to 0.4g/cm by controlling the conditions of crude product refining and crystallization at reduced temperature of 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid3Further reducing the acetic acid residue in the product to below 0.2 percent.
In order to achieve the purpose of the invention, the embodiment of the invention adopts the following technical scheme:
a method for reducing acetic acid residue in the synthesis of 3,3 ', 4, 4' -diphenyl ether dianhydride, comprising the steps of:
step A, mixing the crude 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid, pure water and mixed acid, heating for refining, and after finishing refining, carrying out stepped cooling crystallization to obtain a refined wet 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid, wherein the specific process of the stepped cooling crystallization is as follows: reducing the temperature to 55-60 ℃ at a cooling rate of 20-30 ℃/h, adding 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid seed crystals, and keeping the temperature for 0.5-1 h; then reducing the temperature to 20-30 ℃ at a cooling rate of 10-20 ℃/h, and preserving the temperature for 0.5-1 h; then reducing the temperature to 0-10 ℃ at a cooling rate of 5-10 ℃/h, and preserving the temperature for 0.5-1 h;
step B, drying and crushing the refined wet product of the 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid until the bulk density is less than or equal to 0.4g/cm3To obtain a refined dry product of 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid;
and step C, dehydrating the refined dry 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid product by acetic anhydride, cooling and crystallizing, carrying out solid-liquid separation, drying under reduced pressure, and sieving to obtain 3,3 ', 4, 4' -diphenyl ether dianhydride, wherein inert gas is adopted for intermittent replacement in the drying process.
Compared with the prior art, the method for reducing acetic acid residue in the synthesis of 3,3 ', 4, 4' -diphenyl ether dianhydride provided by the application has the following advantages:
the applicant of the present invention finds, in a large number of experimental research processes, that, in a process of preparing 3,3 ', 4, 4' -diphenyl ether dianhydride by dehydration of acetic anhydride, when the stacking density of the 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid intermediate is higher than 0.5g/cm, it is difficult to remove residual acetic acid, only the acetic acid residue can be reduced to about 0.6%, and the stacking density of the 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid intermediate is also difficult to be reduced to less than 0.5g/cm by using methods such as reduced pressure drying and the like; in addition, the applicant has found that when crude 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid is refined by using mixed acid and specific stepped temperature reduction conditions are adopted, the bulk density of the 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid can be reduced to 0.4g/cm3The acetic acid residue is easily removed after the acetic anhydride is dehydrated, and the effect of reducing the acetic acid residue in the product to be below 2 percent is achieved, so that the acetic acid residue is reduced, the purity and the yield of the 3,3 ', 4, 4' -diphenyl ether dianhydride are improved under the conditions of reducing the drying time and the drying times, and the purposes of reducing energy consumption and improving the production efficiency are achieved.
The method provided by the invention is simple to operate, low in cost, capable of effectively reducing the acetic acid residue of the product and suitable for industrial production.
The reaction for dehydrating the acetic anhydride with the above-mentioned 3,3 ', 4, 4' -diphenylether tetracarboxylic acid is as follows:
optionally, in step B, drying and pulverizing the refined wet product of 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid under reduced pressure until the bulk density is 0.35g/cm3~0.4g/cm3To obtain a refined dry product of 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid;
further optionally, to a bulk density of 0.35g/cm3To obtain the refined dry product of 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid.
According to the method, the bulk density of the refined and dried 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid is controlled, so that acetic acid residues are easily removed after acetic anhydride is dehydrated, and the purpose of improving the quality of the 3,3 ', 4, 4' -diphenyl ether dianhydride is achieved.
Optionally, in step a, the refining conditions are as follows: the rotating speed is 80rpm to 100rpm, the temperature is 60 ℃ to 100 ℃, and the time is 1h to 3 h.
Further optionally, the refining temperature is 70-90 ℃; optionally, the temperature of the refining is 80 ℃.
Further optionally, the refining time is 2 h.
Further optionally, the refining speed is 85 rpm-95 rpm; optionally, the rotation speed of the refining is 90 rpm.
Optionally, in the step A, the temperature rise rate of the temperature rise is 30-35 ℃/h; optionally, the temperature rise rate of the temperature rise is 35 ℃/h.
The optimized refining conditions such as temperature, rotating speed, heating rate and the like enable the refined wet product of the 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid to crystallize in a unique structure and size, and provide a foundation and guarantee for obtaining a dry product with a specific bulk density.
Optionally, in the step a, the mass ratio of the pure water to the 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid crude product is 5-10: 1.
Further optionally, in the step A, the mass ratio of the pure water to the 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid crude product is 5-8: 1; optionally, the mass ratio of the pure water to the crude 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid is 7: 1.
Optionally, in the step a, the mass ratio of the mixed acid to the crude 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid is 0.3-0.5: 1.
Further optionally, in the step a, the mass ratio of the mixed acid to the crude product of 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid is 0.4-0.5: 1; optionally, the mass ratio of the mixed acid to the crude product of 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid is 0.45: 1.
Optionally, the mixed acid comprises inorganic acid and acetic acid in a mass ratio of 2-5: 1, and the inorganic acid is sulfuric acid or hydrochloric acid.
Further optionally, in the step A, the mixed acid comprises inorganic acid and acetic acid in a mass ratio of 3-4: 1; optionally, the mixed acid comprises inorganic acid and acetic acid in a mass ratio of 3.5: 1.
Optionally, the concentration of the sulfuric acid is 40wt% to 50 wt%.
Optionally, the concentration of the hydrochloric acid is 30wt% -36 wt%.
Optionally, the rotating speed of the step cooling crystallization is 50-60 rpm.
Further optionally, the rotation speed of the step cooling crystallization is 55 rpm.
Optionally, in step a, the step cooling crystallization specifically comprises the following steps: cooling to 55 deg.C at a rate of 25 deg.C/h, adding 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid seed crystal, and maintaining for 1 h; then reducing the temperature to 25 ℃ at the cooling rate of 15 ℃/h, and preserving the heat for 1 h; then the temperature is reduced to 5 ℃ at the cooling rate of 10 ℃/h, and the temperature is kept for 1 h.
The optimized step cooling crystallization process, the whole stirring rotating speed and cooling rate, and the step cooling, so that the refined wet product of the 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid is crystallized in a unique structure and size, and a foundation and guarantee are provided for obtaining a dry product with a specific bulk density.
Optionally, the mass ratio of the 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid seed crystal to the crude 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid is 0.0005-0.002: 1.
Further optionally, the mass ratio of the 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid seed crystal to the crude 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid is 0.001: 1.
Optionally, the purity of the 3,3 ', 4, 4' -diphenyl ether tetracetic acid crystal is not less than 99%, and the stacking density is 0.35g/cm through carrying out thin-wall high-speed high-speed high-speed high speed.
Optionally, in step B, the reduced-pressure drying conditions are as follows: the vacuum degree is-0.095 MPa to-0.085 MPa, the steam pressure is 0.2MPa to 0.3MPa, the drying temperature is 100 ℃ to 120 ℃, and the drying time is 6h to 10 h.
Further optionally, in step B, the reduced-pressure drying condition is: the vacuum degree is-0.095 MPa, the steam pressure is 0.25MPa, the drying temperature is 110 ℃, and the drying time is 6-8 h; optionally, the drying time is 8 hours.
The preferable reduced pressure drying condition can make the bulk density of the refined and dried 3,3 ', 4, 4' -diphenyl ether tetraformic acid product reach 0.4g/cm3The following provides a basis for the dehydration of acetic anhydride.
Optionally, in the step B, the fineness of the crushing is 8-20 meshes.
Further optionally, in the step B, the fineness of the pulverization is 10 meshes.
Optionally, in the step C, the temperature of the acetic anhydride dehydration is 60-140 ℃, and the time is 5-10 h.
Further optionally, in the step C, the temperature for dehydrating the acetic anhydride is 80-130 ℃; optionally, the temperature is 120 ℃.
Further optionally, in the step C, the acetic anhydride is dehydrated for 6-8 hours; optionally, the time is 7 h.
Optionally, in the step C, the mass ratio of the acetic anhydride to the refined dried 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid product is 3-8: 1.
Further optionally, in the step C, the mass ratio of the acetic anhydride to the refined dried 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid is 4-6: 1; optionally, the mass ratio of the acetic anhydride to the refined dried 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid is 5: 1.
The preferable conditions of acetic anhydride dehydration, such as temperature, reaction time and addition ratio of the two, make the 3,3 ', 4, 4' -diphenyl ether tetraformic acid refined dry product completely react, reduce the generation of by-products and also facilitate the removal of acetic acid.
Optionally, in the step C, the temperature for cooling and crystallizing is 0-20 ℃, and the time is 0.5-1 h.
Further optionally, in the step C, the temperature for cooling and crystallizing is 10 ℃ and the time is 1 h.
Optionally, in the step C, the solid-liquid separation mode has no special requirements; optionally, the solid-liquid separation is performed in a centrifugal manner.
Optionally, in the step C, the aperture of the sieve is 20-40 meshes.
Further optionally, in step C, the screened aperture is 30 mesh.
Optionally, in step C, the reduced-pressure drying conditions are as follows: the vacuum degree is-0.095 MPa to-0.085 MPa, the steam pressure is 0.2MPa to 0.3MPa, the drying temperature is 100 ℃ to 120 ℃, and the drying time is 10h to 14 h.
Further optionally, in step C, the reduced-pressure drying conditions are as follows: the vacuum degree is-0.095 MPa, the steam pressure is 0.25MPa, the drying temperature is 110 ℃, and the drying time is 11-13 h; optionally, the drying time is 12 h.
The preferable reduced pressure drying condition ensures that the residue of acetic acid in the product is less than 0.2 percent, and the 3,3 ', 4, 4' -diphenyl ether dianhydride product with higher purity is obtained.
Optionally, in step C, the specific process of the intermittent replacement is as follows: and (3) adopting inert gas to unload the vacuum degree to 0MPa, then stopping introducing the inert gas, and continuing to perform reduced pressure drying, wherein the time interval of intermittent replacement is 1-2 h.
Further preferably, the inert gas is nitrogen.
Optionally, the reduced-pressure drying is performed by using an enamel rotating double-cone dryer.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without creative efforts.
FIG. 1 is a reaction equation for dehydration of 3,3 ', 4, 4' -diphenylether tetracarboxylic acid acetic anhydride provided in the examples of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
In the examples of the present invention, all the raw material components are commercially available products well known to those skilled in the art unless otherwise specified.
Example 1
The embodiment of the application provides a method for reducing acetic acid residue in synthesis of 3,3 ', 4, 4' -diphenyl ether dianhydride, which comprises the following steps:
step A, putting 100Kg of crude 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid into an anchor type reaction tank, then adding 700Kg of pure water and 45Kg of mixed acid, heating to 80 ℃ at the speed of 35 ℃/h under the condition of 90rpm, refining for 2h, cooling to 55 ℃ at the speed of 25 ℃/h by using circulating water after heat preservation, adding 0.1Kg of 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid seed crystal, and preserving heat for 1 h; switching cold saline water, reducing the temperature to 25 ℃ at the cooling rate of 15 ℃/h, and preserving the temperature for 1 h; cooling to 5 deg.C at a rate of 10 deg.C/h, maintaining for 1h, and centrifuging to obtain refined wet product of 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid; wherein, the content of the 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid seed crystal is 99.1 percent, and the stacking density is 0.39g/cm for carrying out the thin film cultivation; the mixed acid comprises 35Kg of hydrochloric acid with the concentration of 35wt% and 10Kg of acetic acid;
step B, putting the refined wet 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid product into an enamel bipyramid, setting the steam pressure to be 0.25MPa, the temperature to be 110 ℃, the vacuum degree to be-0.095 MPa, drying for 8h, discharging, and sieving by a 10-mesh shaking granulation machine to obtain 97kg of refined dry 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid product with the stacking density of 0.35g/cm for carrying out the method;
step C, putting 97Kg of refined dry 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid and 485Kg of acetic anhydride into a reaction tank for dehydration reaction, heating to 120 ℃, and preserving heat for 7 hours; then cooling to 10 ℃, preserving heat for 1h, and centrifuging to obtain a 3,3 ', 4, 4' -diphenyl ether dianhydride wet product;
filling the 3,3 ', 4, 4' -diphenyl ether dianhydride wet product into an enamel rotating double cone, setting steam pressure to be 0.25MPa, temperature to be 110 ℃, vacuum degree to be-0.095 MPa, drying for 12h, replacing a vacuum double cone system once every 1h of nitrogen in the drying process, stopping replacement after vacuum pressure in the system is released to be 0MPa, and continuing heating and drying; after drying, discharging, sieving with 30 mesh vibrating sieve, and measuring the content of acetic acid residue in the finished product of 3,3 ', 4, 4' -diphenyl ether dianhydride by 84.6Kg, with purity of 99.7% and yield of 97.0%.
Example 2
The embodiment of the application provides a method for reducing acetic acid residue in synthesis of 3,3 ', 4, 4' -diphenyl ether dianhydride, which comprises the following steps:
step A, putting 100Kg of crude 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid into an anchor type reaction tank, then adding 800Kg of pure water and 40Kg of mixed acid, heating to 70 ℃ at the speed of 33 ℃/h under the condition of 80rpm, refining for 3h, cooling to 60 ℃ at the speed of 30 ℃/h by using circulating water after heat preservation, adding 0.1Kg of 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid seed crystal, and preserving heat for 1 h; switching cold brine, reducing the temperature to 30 ℃ at the cooling rate of 10 ℃/h, and preserving the temperature for 1 h; reducing the temperature to 5 ℃ at the cooling rate of 10 ℃/h, preserving the temperature for 1h, and centrifuging to obtain a refined wet product of the 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid, wherein the content of the 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid seed crystal is 99 percent, and the stacking density is 0.40g/cm for carrying out the thin film epitaxy; the mixed acid comprises 30Kg of sulfuric acid and 10Kg of acetic acid;
step B, putting the refined wet 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid product into an enamel bipyramid, setting the steam pressure to be 0.2MPa, the temperature to be 110 ℃, the vacuum degree to be-0.095 MPa, drying for 6h, discharging, and sieving by using an 8-mesh swing granulator to obtain 96kg of refined dry 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid product, wherein the stacking density is 0.38g/cm for carrying out powder casting;
step C, putting 96Kg of refined and dried 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid and 288Kg of acetic anhydride into a reaction tank for dehydration reaction, heating to 85 ℃, and preserving heat for 10 hours; then cooling to 0 ℃, preserving heat for 0.5h, centrifuging to obtain a 3,3 ', 4, 4' -diphenyl ether dianhydride wet product;
filling the 3,3 ', 4, 4' -diphenyl ether dianhydride wet product into an enamel rotating double cone, setting steam pressure to be 0.3MPa, temperature to be 100 ℃, vacuum degree to be-0.095 MPa, drying for 14h, replacing a vacuum double cone system once every 1h of nitrogen in the drying process, stopping replacement after vacuum pressure in the system is released to be 0MPa, and continuing heating and drying; after drying, discharging, sieving with a 20-mesh vibrating sieve, and obtaining 82.5Kg of finished 3,3 ', 4, 4' -diphenyl ether dianhydride product with a purity of 99.65% and a yield of 95.58%, wherein the acetic acid residue is detected to be 0.18%.
Example 3
The embodiment of the application provides a method for reducing acetic acid residue in synthesis of 3,3 ', 4, 4' -diphenyl ether dianhydride, which comprises the following steps:
step A, putting 100Kg of crude 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid into an anchor type reaction tank, then adding 600Kg of pure water and 50Kg of mixed acid, heating to 90 ℃ at the speed of 30 ℃/h under the condition of 100rpm, refining for 1h, cooling to 55 ℃ at the speed of 25 ℃/h by using circulating water after heat preservation, adding 0.05Kg of 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid seed crystal, and preserving heat for 1 h; switching cold brine, reducing the temperature to 20 ℃ at the cooling rate of 20 ℃/h, and keeping the temperature for 1 h; reducing the temperature to 0 ℃ at the speed of 5 ℃/h, preserving the temperature for 1h, and centrifuging to obtain a refined wet product of the 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid, wherein the content of the 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid seed crystal is 99.1 percent, and the stacking density is 0.35g/cm for carrying out thin film plantation; the mixed acid comprises 40Kg of hydrochloric acid with the concentration of 35wt% and 10Kg of acetic acid;
step B, putting the refined wet 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid product into an enamel bipyramid, setting the steam pressure to be 0.3MPa, the temperature to be 100 ℃, the vacuum degree to be-0.085 MPa, drying for 10h, discharging, and passing through a 10-mesh swing granulator to obtain 96.2kg of refined dry 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid product, wherein the stacking density is 0.37g/cm for carrying out the process;
step C, putting 96.2Kg of refined dry 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid and 481Kg of acetic anhydride into a reaction tank for dehydration reaction, heating to 120 ℃, and keeping the temperature for 8 hours; then cooling to 10 ℃, preserving heat for 1h, and centrifuging to obtain a 3,3 ', 4, 4' -diphenyl ether dianhydride wet product;
filling the 3,3 ', 4, 4' -diphenyl ether dianhydride wet product into an enamel rotating double cone, setting steam pressure to be 0.25MPa, temperature to be 110 ℃, vacuum degree to be-0.095 MPa, drying for 13h, replacing a vacuum double cone system once every 1h of nitrogen in the drying process, stopping replacement after vacuum pressure in the system is released to be 0MPa, and continuing heating and drying; after drying, discharging, sieving with 30 mesh vibrating sieve, and obtaining 82.64Kg finished product of 3,3 ', 4, 4' -diphenyl ether dianhydride with the purity of 99.7% and the yield of 96.74%, and detecting that the acetic acid residue is 0.17%.
Example 4
The embodiment of the application provides a method for reducing acetic acid residue in synthesis of 3,3 ', 4, 4' -diphenyl ether dianhydride, which comprises the following steps:
step A, putting 100Kg of crude 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid into an anchor type reaction tank, then adding 500Kg of pure water and 45Kg of mixed acid, heating to 60 ℃ at the speed of 35 ℃/h under the condition of 90rpm, refining for 2.5h, cooling to 55 ℃ at the speed of 20 ℃/h by using circulating water after heat preservation, adding 0.05Kg of 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid seed crystal, and preserving heat for 1 h; switching cold saline water, reducing the temperature to 25 ℃ at the cooling rate of 15 ℃/h, and preserving the temperature for 1 h; reducing the temperature to 10 ℃ at the cooling rate of 10 ℃/h, preserving the temperature for 1h, and centrifuging to obtain a refined wet product of the 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid, wherein the content of the 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid seed crystal is 99.1 percent, and the stacking density is 0.4g/cm for carrying out thin film plantation; the mixed acid comprises 30Kg of hydrochloric acid with the concentration of 35wt% and 15Kg of acetic acid;
step B, putting the refined wet 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid product into an enamel bipyramid, setting the steam pressure to be 0.25MPa, the temperature to be 115 ℃, the vacuum degree to be-0.095 MPa, drying for 8 hours, discharging, and sieving by a 20-mesh swing granulator to obtain 96kg of refined dry 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid product, wherein the stacking density is 0.35g/cm for carrying out powder casting;
step C, putting 96Kg of refined dry 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid and 384Kg of acetic anhydride into a reaction tank for dehydration reaction, heating to 80 ℃, and preserving heat for 7 hours; then cooling to 15 ℃, preserving heat for 0.8h, centrifuging to obtain a 3,3 ', 4, 4' -diphenyl ether dianhydride wet product;
filling the 3,3 ', 4, 4' -diphenyl ether dianhydride wet product into an enamel rotating double cone, setting steam pressure to be 0.3MPa, temperature to be 110 ℃, vacuum degree to be-0.090 MPa, drying for 12h, replacing a vacuum double cone system once every 2h of nitrogen in the drying process, stopping replacement after vacuum pressure in the system is released to be 0MPa, and continuing heating and drying; after drying, discharging, sieving with a 40-mesh vibrating screen, and obtaining 82.7Kg of finished 3,3 ', 4, 4' -diphenyl ether dianhydride product with a purity of 99.6% and a yield of 95.76%, wherein the acetic acid residue is detected to be 0.18%.
Example 5
The embodiment of the application provides a method for reducing acetic acid residue in synthesis of 3,3 ', 4, 4' -diphenyl ether dianhydride, which comprises the following steps:
step A, putting 100Kg of crude 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid into an anchor type reaction tank, then adding 1000Kg of pure water and 30Kg of mixed acid, heating to 100 ℃ at the speed of 35 ℃/h under the condition of 95rpm, refining for 2h, cooling to 60rpm by using circulating water after heat preservation, cooling to 60 ℃ at the speed of 25 ℃/h, adding 0.1Kg of 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid seed crystal, and preserving heat for 1 h; switching cold brine, reducing the temperature to 30 ℃ at the cooling rate of 20 ℃/h, and preserving the temperature for 1 h; reducing the temperature to 5 ℃ at the speed of 5 ℃/h, preserving the temperature for 1h, and centrifuging to obtain a refined wet product of the 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid, wherein the content of the 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid seed crystal is 99.2 percent, and the stacking density is 0.38g/cm for carrying out thin film plantation; the mixed acid comprises 25Kg of hydrochloric acid with the concentration of 35wt% and 5Kg of acetic acid;
step B, putting the refined wet 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid product into an enamel bipyramid, setting the steam pressure to be 0.3MPa, the temperature to be 120 ℃, the vacuum degree to be-0.090 MPa, drying for 6h, discharging, and sieving by a 10-mesh swing granulator to obtain 95kg of the refined dry 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid product, wherein the stacking density is 0.36g/cm for carrying out powder milling;
step C, putting 95Kg of refined dry 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid and 760Kg of acetic anhydride into a reaction tank for dehydration reaction, heating to 140 ℃, and preserving heat for 5 hours; then cooling to 5 ℃, preserving heat for 0.5h, centrifuging to obtain a 3,3 ', 4, 4' -diphenyl ether dianhydride wet product;
filling the 3,3 ', 4, 4' -diphenyl ether dianhydride wet product into an enamel rotating double cone, setting steam pressure to be 0.2MPa, temperature to be 110 ℃, vacuum degree to be-0.095 MPa, drying for 12h, replacing a vacuum double cone system once every 2h of nitrogen in the drying process, stopping replacement after vacuum pressure in the system is released to be 0MPa, and continuing heating and drying; after drying, discharging, sieving with 30 mesh vibrating screen, 81.7Kg of finished product of 3,3 ', 4, 4' -diphenyl ether dianhydride with purity of 99.69% and yield of 95.68%, detecting acetic acid residue of 0.16%.
Example 6
The embodiment of the application provides a method for reducing acetic acid residue in synthesis of 3,3 ', 4, 4' -diphenyl ether dianhydride, which comprises the following steps:
step A, putting 100Kg of crude 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid into an anchor type reaction tank, then adding 700Kg of pure water and 45Kg of mixed acid, heating to 85 ℃ at the speed of 32 ℃/h under the condition of 85rpm, refining for 2.5h, cooling to 55rpm by using circulating water after heat preservation, cooling to 55 ℃ at the speed of 25 ℃/h, adding 0.1Kg of 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid seed crystal, and preserving heat for 1 h; switching cold saline water, reducing the temperature to 25 ℃ at the cooling rate of 15 ℃/h, and preserving the temperature for 1 h; reducing the temperature to 5 ℃ at the cooling rate of 10 ℃/h, preserving the temperature for 1h, and centrifuging to obtain a refined wet product of the 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid, wherein the content of the 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid seed crystal is 99 percent, and the stacking density is 0.39 g/cm; the mixed acid comprises 35Kg of hydrochloric acid with the concentration of 35wt% and 10Kg of acetic acid;
step B, putting the refined wet 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid product into an enamel bipyramid, setting the steam pressure to be 0.25MPa, the temperature to be 110 ℃, the vacuum degree to be-0.095 MPa, drying for 9h, discharging, and passing through a 15-mesh swing granulator to obtain 96.5kg of refined dry 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid product, wherein the stacking density is 0.35g/cm for carrying out the method;
step C, putting 96.5Kg of refined dry 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid and 485Kg of acetic anhydride into a reaction tank for dehydration reaction, heating to 120 ℃, and preserving heat for 6 hours; then cooling to 10 ℃, preserving heat for 1h, and centrifuging to obtain a 3,3 ', 4, 4' -diphenyl ether dianhydride wet product;
filling the 3,3 ', 4, 4' -diphenyl ether dianhydride wet product into an enamel rotating double cone, setting the steam pressure to be 0.25MPa, the temperature to be 120 ℃, the vacuum degree to be-0.085 MPa, drying for 12h, replacing a vacuum double cone system once every 2h of nitrogen in the drying process, stopping replacement after the vacuum pressure in the system is released to be 0MPa, and continuing heating and drying; after drying, discharging, sieving with 30 mesh vibrating screen, 82.95Kg of 3,3 ', 4, 4' -diphenyl ether dianhydride finished product with purity of 99.7%, yield of 95.64%, and acetic acid residue of 0.16%.
In order to better illustrate the technical solution of the present invention, further comparison is made below by means of a comparative example and an example of the present invention.
Comparative example 1
The comparative example provides a method for reducing acetic acid residue in the synthesis of 3,3 ', 4, 4' -diphenyl ether dianhydride, comprising the steps of:
step A, replacing 35Kg of hydrochloric acid with the concentration of 35wt% and 10Kg of propionic acid with the mixed acid, and keeping the conditions in the rest step A unchanged;
step B, putting the refined wet 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid product into an enamel bipyramid, setting the steam pressure to be 0.25MPa, the temperature to be 110 ℃, the vacuum degree to be-0.095 MPa, drying for 8 hours, discharging, and sieving by a 10-mesh swing granulator to obtain 92kg of refined dry 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid product with the stacking density of 0.52 g/cm;
step C, putting 92Kg of refined and dried 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid and 460Kg of acetic anhydride into a reaction tank for dehydration reaction, heating to 120 ℃, and preserving heat for 7 hours; then cooling to 10 ℃, preserving heat for 1h, and centrifuging to obtain a 3,3 ', 4, 4' -diphenyl ether dianhydride wet product;
filling the 3,3 ', 4, 4' -diphenyl ether dianhydride wet product into an enamel rotating double cone, setting steam pressure to be 0.25MPa, temperature to be 110 ℃, vacuum degree to be-0.095 MPa, drying for 12h, replacing a vacuum double cone system once every 1h of nitrogen in the drying process, stopping replacement after vacuum pressure in the system is released to be 0MPa, and continuing heating and drying; and (3) after drying, discharging, and screening by using a 30-mesh vibrating screen to obtain 74.5Kg of finished 3,3 ', 4, 4' -diphenyl ether dianhydride product with the purity of 99.28 percent and the yield of 89.73 percent, wherein the acetic acid residue is detected to be 0.65 percent.
Comparative example 2
The comparative example provides a method for reducing acetic acid residue in the synthesis of 3,3 ', 4, 4' -diphenyl ether dianhydride, comprising the steps of:
step A, replacing 35Kg of nitric acid and 10Kg of acetic acid with the mixed acid, and keeping the conditions in the rest step A unchanged, wherein the concentration of the nitric acid is 35 wt%;
step B, putting the refined wet 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid product into an enamel bipyramid, setting the steam pressure to be 0.25MPa, the temperature to be 110 ℃, the vacuum degree to be-0.095 MPa, drying for 8 hours, discharging, and passing through a 10-mesh swing granulator to obtain 91.5kg of refined dry 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid product, wherein the stacking density is 0.58g/cm for carrying out the method;
step C, putting 91.5Kg of refined and dried 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid and 457.5Kg of acetic anhydride into a reaction tank for dehydration reaction, heating to 120 ℃, and preserving heat for 7 hours; then cooling to 10 ℃, preserving heat for 1h, and centrifuging to obtain a 3,3 ', 4, 4' -diphenyl ether dianhydride wet product;
filling the 3,3 ', 4, 4' -diphenyl ether dianhydride wet product into an enamel rotating double cone, setting steam pressure to be 0.25MPa, temperature to be 110 ℃, vacuum degree to be-0.095 MPa, drying for 12h, replacing a vacuum double cone system once every 1h of nitrogen in the drying process, stopping replacement after vacuum pressure in the system is released to be 0MPa, and continuing heating and drying; after drying, discharging, sieving with 30 mesh vibrating sieve, and detecting that the acetic acid residue is 0.68% in 73.83Kg of 3,3 ', 4, 4' -diphenyl ether dianhydride finished product, with a purity of 99.25% and a yield of 89.37%.
Comparative example 3
The comparative example provides a method for reducing acetic acid residue in the synthesis of 3,3 ', 4, 4' -diphenyl ether dianhydride, comprising the steps of:
step A, putting 100Kg of crude 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid into an anchor type reaction tank, then adding 700Kg of pure water and 45Kg of mixed acid, heating to 80 ℃ at the speed of 35 ℃/h under the condition of 90rpm, refining for 2h, cooling to 55 ℃ at the speed of 35 ℃/h by using circulating water after heat preservation, adding 0.1Kg of 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid seed crystal, and preserving heat for 1 h; switching cold brine, reducing the temperature to 25 ℃ at the cooling rate of 25 ℃/h, and keeping the temperature for 1 h; cooling to 5 deg.C at a rate of 15 deg.C/h, maintaining for 1h, and centrifuging to obtain refined wet product of 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid; wherein, the content of the 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid seed crystal is 99.1 percent, and the stacking density is 0.39g/cm for carrying out the thin film cultivation; the mixed acid comprises 35Kg of hydrochloric acid and 10Kg of acetic acid;
step B, putting the refined wet 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid product into an enamel bipyramid, setting the steam pressure to be 0.25MPa, the temperature to be 110 ℃, the vacuum degree to be-0.095 MPa, drying for 8h, discharging, and passing through a 10-mesh swing granulator to obtain 92.5 kg of refined dry 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid product with the stacking density of 0.55g/cm for carrying out the process;
step C, putting 92.5 Kg of refined dry 3,3 ', 4, 4' -diphenyl ether tetracarboxylic acid and 462.5Kg of acetic anhydride into a reaction tank for dehydration reaction, heating to 120 ℃, and preserving heat for 7 hours; then cooling to 10 ℃, preserving heat for 1h, and centrifuging to obtain a 3,3 ', 4, 4' -diphenyl ether dianhydride wet product;
filling the 3,3 ', 4, 4' -diphenyl ether dianhydride wet product into an enamel rotating double cone, setting steam pressure to be 0.25MPa, temperature to be 110 ℃, vacuum degree to be-0.095 MPa, drying for 12h, replacing a vacuum double cone system once every 1h of nitrogen in the drying process, stopping replacement after vacuum pressure in the system is released to be 0MPa, and continuing heating and drying; and (3) after drying, discharging, and screening by using a 30-mesh vibrating screen to obtain 74.5Kg of finished 3,3 ', 4, 4' -diphenyl ether dianhydride product with the purity of 99.20% and the yield of 89.17%, wherein the acetic acid residue is detected to be 0.72%.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents or improvements made within the spirit and principle of the present invention should be included in the scope of the present invention.
Claims (10)
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Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1073436A (en) * | 1991-10-25 | 1993-06-23 | 西方化学公司 | The preparation method of the acid anhydrides of oxydiphthalic acid and its purifying |
| US5336788A (en) * | 1993-11-15 | 1994-08-09 | Occidental Chemical Corporation | Method of making oxydiphthalic anhydride |
| CN1800170A (en) * | 2004-12-22 | 2006-07-12 | 通用电气公司 | Method of purifying dianhydrides |
| JP2006213646A (en) * | 2005-02-03 | 2006-08-17 | Mitsubishi Chemicals Corp | Method for producing oxydiphthalic anhydride |
| CN1827611A (en) * | 2006-04-14 | 2006-09-06 | 黑龙江省石油化学研究院 | Process for preparing 3,3',4,4'-tetracarboxydiphthalic ether dianhydride |
| US20060293528A1 (en) * | 2005-06-24 | 2006-12-28 | General Electric Company | Method of purifying dianhydrides |
| US20070073066A1 (en) * | 2005-09-23 | 2007-03-29 | General Electric Company | Method for purifying dianhydrides |
| CN101068799A (en) * | 2004-12-07 | 2007-11-07 | 三菱化学株式会社 | High-purity oxydiphthalic anhydride and its production method |
| CN102046619A (en) * | 2008-03-28 | 2011-05-04 | 沙伯基础创新塑料知识产权有限公司 | Process for purifying dianhydrides, dianhydrides formed thereby, and polyetherimides derived therefrom |
| JP2011195466A (en) * | 2010-03-17 | 2011-10-06 | Air Water Inc | Method for producing purified 3,3',4,4'-diphenyl ether tetracarboxylic acid |
| CN110551085A (en) * | 2019-10-15 | 2019-12-10 | 上海固创化工新材料有限公司 | Preparation method of 3,3',4,4' -diphenyl ether tetracarboxylic dianhydride |
| CN111943922A (en) * | 2020-09-01 | 2020-11-17 | 上海固创化工新材料有限公司 | Method for recycling 3,3', 4,4' -diphenyl ether tetracarboxylic dianhydride from adsorption activated carbon and reusing activated carbon |
| CN113912240A (en) * | 2021-12-13 | 2022-01-11 | 河北海力香料股份有限公司 | Extraction agent and method for treating 4,4' -diphenyl ether dianhydride production wastewater by using same |
-
2022
- 2022-01-25 CN CN202210084611.3A patent/CN114349727B/en active Active
Patent Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1073436A (en) * | 1991-10-25 | 1993-06-23 | 西方化学公司 | The preparation method of the acid anhydrides of oxydiphthalic acid and its purifying |
| US5336788A (en) * | 1993-11-15 | 1994-08-09 | Occidental Chemical Corporation | Method of making oxydiphthalic anhydride |
| CN101068799A (en) * | 2004-12-07 | 2007-11-07 | 三菱化学株式会社 | High-purity oxydiphthalic anhydride and its production method |
| CN1800170A (en) * | 2004-12-22 | 2006-07-12 | 通用电气公司 | Method of purifying dianhydrides |
| JP2006213646A (en) * | 2005-02-03 | 2006-08-17 | Mitsubishi Chemicals Corp | Method for producing oxydiphthalic anhydride |
| US20060293528A1 (en) * | 2005-06-24 | 2006-12-28 | General Electric Company | Method of purifying dianhydrides |
| US20070073066A1 (en) * | 2005-09-23 | 2007-03-29 | General Electric Company | Method for purifying dianhydrides |
| CN1827611A (en) * | 2006-04-14 | 2006-09-06 | 黑龙江省石油化学研究院 | Process for preparing 3,3',4,4'-tetracarboxydiphthalic ether dianhydride |
| CN102046619A (en) * | 2008-03-28 | 2011-05-04 | 沙伯基础创新塑料知识产权有限公司 | Process for purifying dianhydrides, dianhydrides formed thereby, and polyetherimides derived therefrom |
| JP2011195466A (en) * | 2010-03-17 | 2011-10-06 | Air Water Inc | Method for producing purified 3,3',4,4'-diphenyl ether tetracarboxylic acid |
| CN110551085A (en) * | 2019-10-15 | 2019-12-10 | 上海固创化工新材料有限公司 | Preparation method of 3,3',4,4' -diphenyl ether tetracarboxylic dianhydride |
| CN111943922A (en) * | 2020-09-01 | 2020-11-17 | 上海固创化工新材料有限公司 | Method for recycling 3,3', 4,4' -diphenyl ether tetracarboxylic dianhydride from adsorption activated carbon and reusing activated carbon |
| CN113912240A (en) * | 2021-12-13 | 2022-01-11 | 河北海力香料股份有限公司 | Extraction agent and method for treating 4,4' -diphenyl ether dianhydride production wastewater by using same |
Non-Patent Citations (3)
| Title |
|---|
| SAKAKURA, AKIRA等: ""Bronsted Base-Assisted Boronic Acid Catalysis for the Dehydrative Intramolecular Condensation of Dicarboxylic Acids"", 《ORGANIC LETTERS》 * |
| 张春荣等: ""3,3,’4,4’-二苯醚四甲酸二酐的提纯研究"", 《化学与黏合》 * |
| 闫琴等: ""3,3",4,4"-二苯醚二酐的合成工艺研究"", 《精细与专用化学品》 * |
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