阅读说明：本技术 一种可溶性聚酰亚胺树脂的制备方法 (Preparation method of soluble polyimide resin ) 是由 赵智丽 任守陇 董志勇 徐志新 于 2021-09-24 设计创作，主要内容包括：本发明属于聚酰亚胺树脂设备技术领域,尤其是一种可溶性聚酰亚胺树脂的制备方法,将五氧化二磷粉末在真空条件下与多聚磷酸混合,温度控制在110-160°C,通过离心混合搅拌机构进行充分搅拌。该可溶性聚酰亚胺树脂的制备方法,通过设置将五氧化二磷粉末在真空条件下与多聚磷酸混合和二苯醚四羧酸二酐、二苯甲酮四羧酸二酐,可以在保证树脂优良耐热性的同时,显著改善树脂的溶解性能,实现连续化生产,树脂收率高,具有较好的安全性和工业应用性；保证了该类树脂在成型后清洗彻底,并经较低温度干燥后溶剂去除干净的效果,制备工艺简单,成本低,对环境污染小,解决了酚类溶剂毒性较大,不利于工业化等问题。(The invention belongs to the technical field of polyimide resin equipment, and particularly relates to a preparation method of soluble polyimide resin. According to the preparation method of the soluble polyimide resin, phosphorus pentoxide powder is mixed with polyphosphoric acid under a vacuum condition, and diphenyl ether tetracarboxylic dianhydride and benzophenone tetracarboxylic dianhydride are arranged, so that the excellent heat resistance of the resin is ensured, the solubility of the resin is obviously improved, the continuous production is realized, the resin yield is high, and the safety and the industrial applicability are better; the resin is ensured to be thoroughly cleaned after being molded, and the solvent is completely removed after being dried at a lower temperature, the preparation process is simple, the cost is low, the environmental pollution is small, and the problems that the phenol solvent has higher toxicity and is not beneficial to industrialization and the like are solved.)

1. A method for preparing soluble polyimide resin is characterized in that: step one, mixing phosphorus pentoxide powder with polyphosphoric acid under a vacuum condition, controlling the temperature at 110-160 ℃, fully stirring by using a centrifugal mixing and stirring mechanism to obtain polyphosphoric acid mixed solution with the content of 85-95%, and cooling to 40-60 ℃;

step two, adding diphenyl ether tetracarboxylic dianhydride and benzophenone tetracarboxylic dianhydride into the cooled polyphosphoric acid mixed solution, stirring and mixing, carrying out polycondensation reaction after mixing, and carrying out sufficient thermal imidization to obtain a polyimide solution;

and step three, adding an alcohol solvent into the polyimide acid solution to form polyimide solid precipitate, and washing to obtain the polyimide solid.

2. The method for preparing a soluble polyimide resin according to claim 1, wherein: the formula ratio of the diphenyl ether tetracarboxylic dianhydride to the benzophenone tetracarboxylic dianhydride is 1: 0.85.

3. The method for preparing a soluble polyimide resin according to claim 1, wherein: the alcohol solvent is added into the polyimide acid solution, and the flow rate of the alcohol solvent is controlled to be 2-90 m/min.

4. The method for preparing a soluble polyimide resin according to claim 1, wherein: the temperature of the polycondensation reaction is between 190 ℃ and 210 ℃ for 3.5 to 5.5 hours, and then the polycondensation reaction is carried out at 230 ℃ and 260 ℃ for 1.5 to 2.5 hours.

5. The method for preparing a soluble polyimide resin according to claim 1, wherein: the washing temperature is controlled at 130-170 ℃ and the drying time is 3.5-6.5 hours, and then the drying time is 5.5-13 hours at 260-310 ℃.

6. The method for preparing a soluble polyimide resin according to claim 1, wherein: centrifugal mixing stirring mechanism is including supporting leg (1), a plurality of the equal fixedly connected with mixing box (2) in top of supporting leg (1), the interior diapire center of mixing box (2) is connected with discharging pipe (3) through the bearing rotation, the bottom of discharging pipe (3) is run through and is extended to the bottom of mixing box (2).

7. The method for preparing a soluble polyimide resin according to claim 6, wherein: the surface of discharging pipe (3) is fixed mounting respectively has first valve (4) and first gear (5), one of them the fixed surface of supporting leg (1) installs connecting plate (6), the fixed surface of connecting plate (6) installs driving motor (7), the output shaft of driving motor (7) passes through shaft coupling fixed mounting and has gear shaft (8), the one end fixed mounting of gear shaft (8) has second gear (9), the surface of second gear (9) and the surface engagement of first gear (5).

8. The method for preparing a soluble polyimide resin according to claim 6, wherein: the top fixed mounting of discharging pipe (3) has centrifuge box (10), rotation groove (11) have been seted up to the interior roof of mixing box (2), the top surface slip grafting of the inner wall of rotation groove (11) and centrifuge box (10), the bottom inner wall of centrifuge box (10) is the slope shape.

9. The method for preparing a soluble polyimide resin according to claim 6, wherein: the interior roof center fixed mounting of mixing box (2) has puddler (12), the fixed intercommunication in top one side of mixing box (2) has inlet pipe (13), the fixed surface of inlet pipe (13) installs second valve (14).

10. The method for preparing a soluble polyimide resin according to claim 8, wherein: the outer fixed surface of centrifugal box (10) installs spiral heating pipe (15), the top one side fixed mounting of spiral heating pipe (15) has carbon brush (16), electrically conductive groove (17) have been seted up to the top inside wall of mixing box (2), the inner wall fixed mounting of electrically conductive groove (17) has electrically conductive circle (18), the surface of electrically conductive circle (18) is pegged graft with the surface slip of carbon brush (16), and electrically conductive circle (18) with carbon brush (16) electric connection.

Technical Field

The invention relates to the technical field of polyimide resin equipment, in particular to a preparation method of soluble polyimide resin.

Background

Polyimide refers to a class of polymers containing imide rings (-CO-N-CO-) on the main chain, and is one of organic polymer materials with the best comprehensive performance. The high-temperature-resistant insulating material has high temperature resistance of more than 400 ℃, long-term use temperature range of-200-300 ℃, no obvious melting point in part, high insulating property, dielectric constant of 4.0 at 103 Hz and dielectric loss of only 0.004-0.007, and belongs to F-H grade insulation.

Polyimides can be classified into aliphatic, semi-aromatic and aromatic polyimides according to the chemical structure of the repeating unit. The crosslinking type and the non-crosslinking type are classified according to the interaction force between chains. Polyimide is used as a special engineering material and has been widely applied to the fields of aviation, aerospace, microelectronics, nano-scale, liquid crystal, separation membranes, laser and the like. In the last 60 th century, the research, development and utilization of polyimide was listed as one of the most promising engineering plastics in 21 st century in all countries. Polyimide, because of its outstanding characteristics in terms of performance and synthesis, whether as a structural material or as a functional material, has great potential for applications that have been fully recognized and is known as "problem-solving" and is considered "without polyimide, there is no current microelectronics technology".

The existing method for preparing the soluble polyimide resin has the disadvantages that the stirring and mixing are carried out by adopting a common stirring rod during stirring and mixing in the production of the polyimide resin, the stirring and mixing efficiency is low, residues are easily caused during discharging, the discharging is difficult to completely discharge, the post-treatment is difficult, the solubility of the produced resin is low, the polyamic acid intermediate is generally unstable, the storage is difficult for a long time, and the post-treatment is troublesome, so that the method for preparing the soluble polyimide resin is needed.

Disclosure of Invention

Based on the technical problems that the existing method for preparing the soluble polyimide resin adopts a common stirring rod to rotate, stir and mix when stirring and mixing the polyimide resin, has low stirring and mixing efficiency, easily causes residue during discharging, is difficult to completely discharge, is difficult to post-treat, has low solubility after resin generation, is generally unstable in polyamic acid intermediate, is difficult to store for a long time, and has troublesome post-treatment, the invention provides the method for preparing the soluble polyimide resin.

The preparation method of the soluble polyimide resin comprises the following steps of firstly, mixing phosphorus pentoxide powder with polyphosphoric acid under a vacuum condition, controlling the temperature at 110-160 ℃, fully stirring by using a centrifugal mixing and stirring mechanism to obtain polyphosphoric acid mixed solution with the content of 85-95%, and cooling to 40-60 ℃;

step two, adding diphenyl ether tetracarboxylic dianhydride and benzophenone tetracarboxylic dianhydride into the cooled polyphosphoric acid mixed solution, stirring and mixing, carrying out polycondensation reaction after mixing, and carrying out sufficient thermal imidization to obtain a polyimide solution;

and step three, adding an alcohol solvent into the polyimide acid solution to form polyimide solid precipitate, and washing to obtain the polyimide solid.

Preferably, the formula ratio of the diphenyl ether tetracarboxylic dianhydride to the benzophenone tetracarboxylic dianhydride is 1: 0.85.

Preferably, the alcohol solvent is added into the polyimide acid solution, and the flow rate is controlled to be 2-90 m/min.

Preferably, the polycondensation reaction is carried out at a temperature of 190 ℃ and 210 ℃ for 3.5-5.5 hours and then at a temperature of 230 ℃ and 260 ℃ for 1.5-2.5 hours.

Preferably, the temperature of the washing is controlled to be 130-170 ℃ for drying for 3.5-6.5 hours, and then is controlled to be 260-310 ℃ for drying for 5.5-13 hours.

Preferably, the centrifugal mixing and stirring mechanism comprises supporting legs, the tops of the supporting legs are fixedly connected with a mixing box, the center of the inner bottom wall of the mixing box is rotatably connected with a discharge pipe through a bearing, and the bottom end of the discharge pipe penetrates through and extends to the bottom end of the mixing box;

through above-mentioned technical scheme, reached the fixed back discharging pipe of mixing box and can rotate rotatory effect.

Preferably, the surface of the discharge pipe is fixedly provided with a first valve and a first gear respectively, the surface of one of the support legs is fixedly provided with a connecting plate, the surface of the connecting plate is fixedly provided with a driving motor, an output shaft of the driving motor is fixedly provided with a gear shaft through a coupler, one end of the gear shaft is fixedly provided with a second gear, and the surface of the second gear is meshed with the surface of the first gear;

through above-mentioned technical scheme, it is rotatory to have reached driving motor work and have driven the gear shaft to it is rotatory to drive the second gear rotation and drive first gear through the meshing, thereby drives the effect of the rotatory work of discharging pipe.

Preferably, a centrifugal box is fixedly mounted at the top end of the discharge pipe, a rotating groove is formed in the inner top wall of the mixing box, the inner wall of the rotating groove is in sliding insertion connection with the top surface of the centrifugal box, and the inner wall of the bottom end of the centrifugal box is in an inclined shape;

through above-mentioned technical scheme, thereby it is rotatory to have reached the discharging pipe and drive the centrifuge box, makes inside centrifugal force that produces, and the mixed liquid of control inside mixes the stirring under the condition of centrifugal force, is the slope shape through the bottom and has reached the effect that the inside mixed liquid of the direction control of being convenient for flows to and the setting of rotating the groove controls the effect of the spacing direction in top of centrifuge box.

Preferably, a stirring rod is fixedly installed in the center of the inner top wall of the mixing box, a feeding pipe is fixedly communicated with one side of the top of the mixing box, and a second valve is fixedly installed on the surface of the feeding pipe;

through the technical scheme, the effect that the mixed liquid collides, contacts and rotates with the stirring rod under the condition of centrifugal force is achieved.

Preferably, the outer surface of the centrifugal box is fixedly provided with a spiral heating pipe, one side of the top end of the spiral heating pipe is fixedly provided with a carbon brush, the inner side wall of the top end of the mixing box is provided with a conductive groove, the inner wall of the conductive groove is fixedly provided with a conductive ring, the surface of the conductive ring is in sliding insertion connection with the surface of the carbon brush, and the conductive ring is electrically connected with the carbon brush;

through above-mentioned technical scheme, reached control spiral heating pipe work among the hybrid heating and carried out the effect of ohmic heating, reached the centrifuge box rotation through carbon brush and conductive coil electric connection, can also carry out the effect of screw thread heating pipe circular telegram, avoided the winding effect of current wired connection control line.

The beneficial effects of the invention are as follows:

1. by mixing phosphorus pentoxide powder with polyphosphoric acid under a vacuum condition and mixing diphenyl ether tetracarboxylic dianhydride and benzophenone tetracarboxylic dianhydride, the excellent heat resistance of the resin can be ensured, the dissolving performance of the resin is obviously improved, continuous production is realized, the resin yield is high, and the safety and industrial applicability are better; the resin is ensured to be thoroughly cleaned after being molded, and the solvent is completely removed after being dried at a lower temperature, the preparation process is simple, the cost is low, the environmental pollution is small, and the problems that the phenol solvent has higher toxicity and is not beneficial to industrialization and the like are solved.

2. Mix rabbling mechanism through setting up the centrifugation and reached during the stirring mixing operation, it is rotatory under the effect of centrifugal force to drive inside mixing liquid through the centrifugation case is rotatory, with the puddler contact stirring, the effect that the reinforcing stirring was mixed to and open the inside mixing liquid of second valve control under the condition of centrifugal force during the ejection of compact and be tornado shape downstream outflow, the ejection of compact thoroughly prevents to adhere to the inner wall at the centrifugation case.

Drawings

FIG. 1 is a schematic structural view of a process for preparing a soluble polyimide resin;

FIG. 2 is a half sectional view showing a structure of a mixing box in a method for preparing a soluble polyimide resin;

FIG. 3 is a top view of a conductive groove structure of a method for preparing a soluble polyimide resin;

FIG. 4 is a perspective view of a spiral heating tube structure of a method for preparing a soluble polyimide resin;

fig. 5 is an enlarged view of a structure a in fig. 2 of a method for preparing a soluble polyimide resin.

In the figure: 1. supporting legs; 2. a mixing box; 3. a discharge pipe; 4. a first valve; 5. a first gear; 6. a connecting plate; 7. a drive motor; 8. a gear shaft; 9. a second gear; 10. a centrifuge box; 11. a rotating groove; 12. a stirring rod; 13. a feed pipe; 14. a second valve; 15. a spiral heating pipe; 16. a carbon brush; 17. a conductive slot; 18. and a conductive ring.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.

Referring to fig. 1-5, a method for preparing soluble polyimide resin comprises the steps of firstly, mixing phosphorus pentoxide powder with polyphosphoric acid under vacuum condition, controlling the temperature at 110-;

step two, adding diphenyl ether tetracarboxylic dianhydride and benzophenone tetracarboxylic dianhydride into the cooled polyphosphoric acid mixed solution, stirring and mixing, carrying out polycondensation reaction after mixing, and carrying out sufficient thermal imidization to obtain a polyimide solution, wherein the formula ratio of the diphenyl ether tetracarboxylic dianhydride to the benzophenone tetracarboxylic dianhydride is 1: 0.85; the temperature of the polycondensation reaction is between 190 ℃ and 210 ℃ for 3.5 to 5.5 hours, and then the polycondensation reaction is carried out at 230 ℃ and 260 ℃ for 1.5 to 2.5 hours; (ii) a

Adding an alcohol solvent into the polyimide acid solution to form polyimide solid precipitate, washing to obtain polyimide solid, and adding the alcohol solvent into the polyimide acid solution, wherein the flow rate is controlled to be 2-90 m/min; the washing temperature is controlled at 130-170 ℃, the drying time is 3.5-6.5 hours, and then the drying time is 5.5-13 hours under 260-310 ℃;

by mixing phosphorus pentoxide powder with polyphosphoric acid under a vacuum condition and mixing diphenyl ether tetracarboxylic dianhydride and benzophenone tetracarboxylic dianhydride, the excellent heat resistance of the resin can be ensured, the dissolving performance of the resin is obviously improved, continuous production is realized, the resin yield is high, and the safety and industrial applicability are better; the resin is ensured to be thoroughly cleaned after being molded, and the solvent is completely removed after being dried at a lower temperature, the preparation process is simple, the cost is low, the environmental pollution is small, and the problems that the phenol solvent has higher toxicity and is not beneficial to industrialization and the like are solved;

the centrifugal mixing and stirring mechanism comprises supporting legs 1, wherein the tops of a plurality of supporting legs 1 are fixedly connected with a mixing box 2, the center of the inner bottom wall of the mixing box 2 is rotatably connected with a discharging pipe 3 through a bearing, and the bottom end of the discharging pipe 3 penetrates through and extends to the bottom end of the mixing box 2;

the surface of the discharge pipe 3 is fixedly provided with a first valve 4 and a first gear 5 respectively, the surface of one of the support legs 1 is fixedly provided with a connecting plate 6, the surface of the connecting plate 6 is fixedly provided with a driving motor 7, an output shaft of the driving motor 7 is fixedly provided with a gear shaft 8 through a coupler, one end of the gear shaft 8 is fixedly provided with a second gear 9, and the surface of the second gear 9 is meshed with the surface of the first gear 5;

the top fixed mounting of discharging pipe 3 has centrifuge box 10, the interior roof of mixing box 2 has seted up rotation tank 11, the inner wall of rotation tank 11 is pegged graft with the top surface slip of centrifuge box 10, the bottom inner wall of centrifuge box 10 is the slope shape, through the above-mentioned technical scheme, it is rotatory thereby to have reached discharging pipe 3 and drive centrifuge box 10 rotatory, make inside production centrifugal force, the mixed liquid of control inside mixes the stirring under the condition of centrifugal force, it has reached the effect of the mixed liquid outflow of the interior guided control of being convenient for to be the slope shape through the bottom, and the top spacing effect of leading of centrifuge box 10 is controlled in the setting of rotation tank 11;

the stirring rod 12 is fixedly installed in the center of the inner top wall of the mixing box 2, the feeding pipe 13 is fixedly communicated with one side of the top of the mixing box 2, and the second valve 14 is fixedly installed on the surface of the feeding pipe 13;

the outer surface of the centrifugal box 10 is fixedly provided with the spiral heating pipe 15, one side of the top end of the spiral heating pipe 15 is fixedly provided with the carbon brush 16, the inner side wall of the top end of the mixing box 2 is provided with the conductive groove 17, the inner wall of the conductive groove 17 is fixedly provided with the conductive ring 18, the surface of the conductive ring 18 is in sliding insertion connection with the surface of the carbon brush 16, and the conductive ring 18 is electrically connected with the carbon brush 16;

mix rabbling mechanism through setting up the centrifugation and reached during the stirring mixing operation, rotatory inside mixed liquid that drives through centrifuge box 10 is rotatory under the effect of centrifugal force, with puddler 12 contact stirring, the effect that the reinforcing stirring was mixed to and open the inside mixed liquid of second valve 14 control under the condition of centrifugal force during the ejection of compact and be tornado shape downstream outflow, the ejection of compact thoroughly prevents to adhere to the inner wall at centrifuge box 10.

The working principle is as follows: in the mixing operation, the driving motor 7 is controlled to work to drive the gear shaft 8 to rotate, so as to drive the second gear 9 to rotate, the first gear 5 is driven to rotate under the meshed condition, so as to drive the discharge pipe 3 to rotate, the centrifugal box 10 is controlled to rotate, the internal mixed liquid is controlled to generate centrifugal force, so as to be collided and mixed with the stirring rod 12 under the centrifugal force condition, meanwhile, when heating is needed, the conductive ring 18 is controlled to electrify the carbon brush 16, and the spiral heating pipe 15 is controlled to work to generate heat for heating.

Example one

Referring to fig. 1 to 5, a method for preparing a soluble polyimide resin includes the steps of firstly, mixing phosphorus pentoxide powder with polyphosphoric acid under a vacuum condition, controlling the temperature at 110 ℃, sufficiently stirring by a centrifugal mixing stirring mechanism to obtain a polyphosphoric acid mixed solution with the content of 85%, and cooling to 40 ℃;

step two, adding diphenyl ether tetracarboxylic dianhydride and benzophenone tetracarboxylic dianhydride into the cooled polyphosphoric acid mixed solution, stirring and mixing, carrying out polycondensation reaction after mixing, and carrying out sufficient thermal imidization to obtain a polyimide solution, wherein the formula ratio of the diphenyl ether tetracarboxylic dianhydride to the benzophenone tetracarboxylic dianhydride is 1: 0.85; the temperature of the polycondensation reaction is 190 ℃ for 3.5 hours, and then the reaction is carried out at 230 ℃ for 1.5 hours;

adding an alcohol solvent into the polyimide acid solution to form polyimide solid precipitate, washing to obtain polyimide solid, and adding the alcohol solvent into the polyimide acid solution, wherein the flow rate is controlled at 30 m/min; the washing temperature is controlled at 130 ℃, the drying is carried out for 3.5 hours, and then the drying is carried out for 5.5 hours at 260 ℃;

by mixing phosphorus pentoxide powder with polyphosphoric acid under a vacuum condition and mixing diphenyl ether tetracarboxylic dianhydride and benzophenone tetracarboxylic dianhydride, the excellent heat resistance of the resin can be ensured, the dissolving performance of the resin is obviously improved, continuous production is realized, the resin yield is high, and the safety and industrial applicability are better; the resin is ensured to be thoroughly cleaned after being molded, and the solvent is completely removed after being dried at a lower temperature, the preparation process is simple, the cost is low, the environmental pollution is small, and the problems that the phenol solvent has higher toxicity and is not beneficial to industrialization and the like are solved;

the centrifugal mixing and stirring mechanism comprises supporting legs 1, wherein the tops of a plurality of supporting legs 1 are fixedly connected with a mixing box 2, the center of the inner bottom wall of the mixing box 2 is rotatably connected with a discharging pipe 3 through a bearing, and the bottom end of the discharging pipe 3 penetrates through and extends to the bottom end of the mixing box 2;

the surface of the discharge pipe 3 is fixedly provided with a first valve 4 and a first gear 5 respectively, the surface of one of the support legs 1 is fixedly provided with a connecting plate 6, the surface of the connecting plate 6 is fixedly provided with a driving motor 7, an output shaft of the driving motor 7 is fixedly provided with a gear shaft 8 through a coupler, one end of the gear shaft 8 is fixedly provided with a second gear 9, and the surface of the second gear 9 is meshed with the surface of the first gear 5;

the top fixed mounting of discharging pipe 3 has centrifuge box 10, the interior roof of mixing box 2 has seted up rotation tank 11, the inner wall of rotation tank 11 is pegged graft with the top surface slip of centrifuge box 10, the bottom inner wall of centrifuge box 10 is the slope shape, through the above-mentioned technical scheme, it is rotatory thereby to have reached discharging pipe 3 and drive centrifuge box 10 rotatory, make inside production centrifugal force, the mixed liquid of control inside mixes the stirring under the condition of centrifugal force, it has reached the effect of the mixed liquid outflow of the interior guided control of being convenient for to be the slope shape through the bottom, and the top spacing effect of leading of centrifuge box 10 is controlled in the setting of rotation tank 11;

the stirring rod 12 is fixedly installed in the center of the inner top wall of the mixing box 2, the feeding pipe 13 is fixedly communicated with one side of the top of the mixing box 2, and the second valve 14 is fixedly installed on the surface of the feeding pipe 13;

the outer surface of the centrifugal box 10 is fixedly provided with the spiral heating pipe 15, one side of the top end of the spiral heating pipe 15 is fixedly provided with the carbon brush 16, the inner side wall of the top end of the mixing box 2 is provided with the conductive groove 17, the inner wall of the conductive groove 17 is fixedly provided with the conductive ring 18, the surface of the conductive ring 18 is in sliding insertion connection with the surface of the carbon brush 16, and the conductive ring 18 is electrically connected with the carbon brush 16;

mix rabbling mechanism through setting up the centrifugation and reached during the stirring mixing operation, rotatory inside mixed liquid that drives through centrifuge box 10 is rotatory under the effect of centrifugal force, with puddler 12 contact stirring, the effect that the reinforcing stirring was mixed to and open the inside mixed liquid of second valve 14 control under the condition of centrifugal force during the ejection of compact and be tornado shape downstream outflow, the ejection of compact thoroughly prevents to adhere to the inner wall at centrifuge box 10.

The working principle is as follows: in the mixing operation, the driving motor 7 is controlled to work to drive the gear shaft 8 to rotate, so as to drive the second gear 9 to rotate, the first gear 5 is driven to rotate under the meshed condition, so as to drive the discharge pipe 3 to rotate, the centrifugal box 10 is controlled to rotate, the internal mixed liquid is controlled to generate centrifugal force, so as to be collided and mixed with the stirring rod 12 under the centrifugal force condition, meanwhile, when heating is needed, the conductive ring 18 is controlled to electrify the carbon brush 16, and the spiral heating pipe 15 is controlled to work to generate heat for heating.

Example two

Referring to fig. 1 to 5, a method for preparing a soluble polyimide resin includes the steps of firstly, mixing phosphorus pentoxide powder with polyphosphoric acid under a vacuum condition, controlling the temperature at 135 ℃, sufficiently stirring by a centrifugal mixing stirring mechanism to obtain a polyphosphoric acid mixed solution with the content of 90%, and cooling to 50 ℃;

step two, adding diphenyl ether tetracarboxylic dianhydride and benzophenone tetracarboxylic dianhydride into the cooled polyphosphoric acid mixed solution, stirring and mixing, carrying out polycondensation reaction after mixing, and carrying out sufficient thermal imidization to obtain a polyimide solution, wherein the formula ratio of the diphenyl ether tetracarboxylic dianhydride to the benzophenone tetracarboxylic dianhydride is 1: 0.85; the temperature of the polycondensation reaction is 200 ℃ for 4.5 hours, and then the reaction is carried out at 245 ℃ for 3.5 hours;

adding an alcohol solvent into the polyimide acid solution to form polyimide solid precipitate, washing to obtain polyimide solid, and adding the alcohol solvent into the polyimide acid solution, wherein the flow rate is controlled at 60 m/min; drying for 5 hours at the washing temperature of 150 ℃, and drying for 7.5 hours at 285 ℃;

by mixing phosphorus pentoxide powder with polyphosphoric acid under a vacuum condition and mixing diphenyl ether tetracarboxylic dianhydride and benzophenone tetracarboxylic dianhydride, the excellent heat resistance of the resin can be ensured, the dissolving performance of the resin is obviously improved, continuous production is realized, the resin yield is high, and the safety and industrial applicability are better; the resin is ensured to be thoroughly cleaned after being molded, and the solvent is completely removed after being dried at a lower temperature, the preparation process is simple, the cost is low, the environmental pollution is small, and the problems that the phenol solvent has higher toxicity and is not beneficial to industrialization and the like are solved;

the centrifugal mixing and stirring mechanism comprises supporting legs 1, wherein the tops of a plurality of supporting legs 1 are fixedly connected with a mixing box 2, the center of the inner bottom wall of the mixing box 2 is rotatably connected with a discharging pipe 3 through a bearing, and the bottom end of the discharging pipe 3 penetrates through and extends to the bottom end of the mixing box 2;

the surface of the discharge pipe 3 is fixedly provided with a first valve 4 and a first gear 5 respectively, the surface of one of the support legs 1 is fixedly provided with a connecting plate 6, the surface of the connecting plate 6 is fixedly provided with a driving motor 7, an output shaft of the driving motor 7 is fixedly provided with a gear shaft 8 through a coupler, one end of the gear shaft 8 is fixedly provided with a second gear 9, and the surface of the second gear 9 is meshed with the surface of the first gear 5;

the top fixed mounting of discharging pipe 3 has centrifuge box 10, the interior roof of mixing box 2 has seted up rotation tank 11, the inner wall of rotation tank 11 is pegged graft with the top surface slip of centrifuge box 10, the bottom inner wall of centrifuge box 10 is the slope shape, through the above-mentioned technical scheme, it is rotatory thereby to have reached discharging pipe 3 and drive centrifuge box 10 rotatory, make inside production centrifugal force, the mixed liquid of control inside mixes the stirring under the condition of centrifugal force, it has reached the effect of the mixed liquid outflow of the interior guided control of being convenient for to be the slope shape through the bottom, and the top spacing effect of leading of centrifuge box 10 is controlled in the setting of rotation tank 11;

the stirring rod 12 is fixedly installed in the center of the inner top wall of the mixing box 2, the feeding pipe 13 is fixedly communicated with one side of the top of the mixing box 2, and the second valve 14 is fixedly installed on the surface of the feeding pipe 13;

the outer surface of the centrifugal box 10 is fixedly provided with the spiral heating pipe 15, one side of the top end of the spiral heating pipe 15 is fixedly provided with the carbon brush 16, the inner side wall of the top end of the mixing box 2 is provided with the conductive groove 17, the inner wall of the conductive groove 17 is fixedly provided with the conductive ring 18, the surface of the conductive ring 18 is in sliding insertion connection with the surface of the carbon brush 16, and the conductive ring 18 is electrically connected with the carbon brush 16;

mix rabbling mechanism through setting up the centrifugation and reached during the stirring mixing operation, rotatory inside mixed liquid that drives through centrifuge box 10 is rotatory under the effect of centrifugal force, with puddler 12 contact stirring, the effect that the reinforcing stirring was mixed to and open the inside mixed liquid of second valve 14 control under the condition of centrifugal force during the ejection of compact and be tornado shape downstream outflow, the ejection of compact thoroughly prevents to adhere to the inner wall at centrifuge box 10.

The working principle is as follows: in the mixing operation, the driving motor 7 is controlled to work to drive the gear shaft 8 to rotate, so as to drive the second gear 9 to rotate, the first gear 5 is driven to rotate under the meshed condition, so as to drive the discharge pipe 3 to rotate, the centrifugal box 10 is controlled to rotate, the internal mixed liquid is controlled to generate centrifugal force, so as to be collided and mixed with the stirring rod 12 under the centrifugal force condition, meanwhile, when heating is needed, the conductive ring 18 is controlled to electrify the carbon brush 16, and the spiral heating pipe 15 is controlled to work to generate heat for heating.

EXAMPLE III

Referring to fig. 1 to 5, a method for preparing a soluble polyimide resin includes the steps of firstly, mixing phosphorus pentoxide powder with polyphosphoric acid under a vacuum condition, controlling the temperature at 160 ℃, sufficiently stirring by a centrifugal mixing stirring mechanism to obtain a polyphosphoric acid mixed solution with a content of 95%, and cooling to 60 ℃;

step two, adding diphenyl ether tetracarboxylic dianhydride and benzophenone tetracarboxylic dianhydride into the cooled polyphosphoric acid mixed solution, stirring and mixing, carrying out polycondensation reaction after mixing, and carrying out sufficient thermal imidization to obtain a polyimide solution, wherein the formula ratio of the diphenyl ether tetracarboxylic dianhydride to the benzophenone tetracarboxylic dianhydride is 1: 0.85; the temperature of the polycondensation reaction is 210 ℃ for 5.5 hours, and then the reaction is carried out at 260 ℃ for 2.5 hours;

adding an alcohol solvent into the polyimide acid solution to form polyimide solid precipitate, washing to obtain polyimide solid, and adding the alcohol solvent into the polyimide acid solution, wherein the flow rate is controlled at 90 m/min; the washing temperature is controlled at 170 ℃, the drying is carried out for 6.5 hours, and then the drying is carried out for 13 hours at 310 ℃;

by mixing phosphorus pentoxide powder with polyphosphoric acid under a vacuum condition and mixing diphenyl ether tetracarboxylic dianhydride and benzophenone tetracarboxylic dianhydride, the excellent heat resistance of the resin can be ensured, the dissolving performance of the resin is obviously improved, continuous production is realized, the resin yield is high, and the safety and industrial applicability are better; the resin is ensured to be thoroughly cleaned after being molded, and the solvent is completely removed after being dried at a lower temperature, the preparation process is simple, the cost is low, the environmental pollution is small, and the problems that the phenol solvent has higher toxicity and is not beneficial to industrialization and the like are solved;

the centrifugal mixing and stirring mechanism comprises supporting legs 1, wherein the tops of a plurality of supporting legs 1 are fixedly connected with a mixing box 2, the center of the inner bottom wall of the mixing box 2 is rotatably connected with a discharging pipe 3 through a bearing, and the bottom end of the discharging pipe 3 penetrates through and extends to the bottom end of the mixing box 2;

the surface of the discharge pipe 3 is fixedly provided with a first valve 4 and a first gear 5 respectively, the surface of one of the support legs 1 is fixedly provided with a connecting plate 6, the surface of the connecting plate 6 is fixedly provided with a driving motor 7, an output shaft of the driving motor 7 is fixedly provided with a gear shaft 8 through a coupler, one end of the gear shaft 8 is fixedly provided with a second gear 9, and the surface of the second gear 9 is meshed with the surface of the first gear 5;

the top fixed mounting of discharging pipe 3 has centrifuge box 10, the interior roof of mixing box 2 has seted up rotation tank 11, the inner wall of rotation tank 11 is pegged graft with the top surface slip of centrifuge box 10, the bottom inner wall of centrifuge box 10 is the slope shape, through the above-mentioned technical scheme, it is rotatory thereby to have reached discharging pipe 3 and drive centrifuge box 10 rotatory, make inside production centrifugal force, the mixed liquid of control inside mixes the stirring under the condition of centrifugal force, it has reached the effect of the mixed liquid outflow of the interior guided control of being convenient for to be the slope shape through the bottom, and the top spacing effect of leading of centrifuge box 10 is controlled in the setting of rotation tank 11;

the stirring rod 12 is fixedly installed in the center of the inner top wall of the mixing box 2, the feeding pipe 13 is fixedly communicated with one side of the top of the mixing box 2, and the second valve 14 is fixedly installed on the surface of the feeding pipe 13;

the outer surface of the centrifugal box 10 is fixedly provided with the spiral heating pipe 15, one side of the top end of the spiral heating pipe 15 is fixedly provided with the carbon brush 16, the inner side wall of the top end of the mixing box 2 is provided with the conductive groove 17, the inner wall of the conductive groove 17 is fixedly provided with the conductive ring 18, the surface of the conductive ring 18 is in sliding insertion connection with the surface of the carbon brush 16, and the conductive ring 18 is electrically connected with the carbon brush 16;

mix rabbling mechanism through setting up the centrifugation and reached during the stirring mixing operation, rotatory inside mixed liquid that drives through centrifuge box 10 is rotatory under the effect of centrifugal force, with puddler 12 contact stirring, the effect that the reinforcing stirring was mixed to and open the inside mixed liquid of second valve 14 control under the condition of centrifugal force during the ejection of compact and be tornado shape downstream outflow, the ejection of compact thoroughly prevents to adhere to the inner wall at centrifuge box 10.

The working principle is as follows: in the mixing operation, the driving motor 7 is controlled to work to drive the gear shaft 8 to rotate, so as to drive the second gear 9 to rotate, the first gear 5 is driven to rotate under the meshed condition, so as to drive the discharge pipe 3 to rotate, the centrifugal box 10 is controlled to rotate, the internal mixed liquid is controlled to generate centrifugal force, so as to be collided and mixed with the stirring rod 12 under the centrifugal force condition, meanwhile, when heating is needed, the conductive ring 18 is controlled to electrify the carbon brush 16, and the spiral heating pipe 15 is controlled to work to generate heat for heating.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.