KR20160077480A - Method for the continuous manufacture of polyimide precursor solution, polyimide film manufactured by thereof - Google Patents

Abstract

The present invention relates to a method for continuously producing a polyimide precursor solution by continuously putting, into a reactor, dianhydride and a diamine monomer, dissolved in a polymerizing solvent, in the same mole fraction. According to the present invention, it is possible to easily adjust the equivalence ratio, since uniform insertion of both dianhydride and diamine used as raw materials is possible. In addition production of polyamic acid having uniform material properties is also possible, thereby securing excellent processability in a post-process, improved mechanical properties, and high quality of products in the production of films as well.

Description

[0001] The present invention relates to a method for continuously producing a polyimide precursor solution and a polyimide film prepared by the method,

The present invention relates to a continuous process for producing a polyimide precursor solution and a polyimide film produced thereby. More specifically, the present invention relates to a process for continuously producing a polyimide precursor solution by mixing a mixture of two monomers into a polymerization reaction tank, Lt; RTI ID = 0.0 > polyimide < / RTI > precursor solution.

The wholly aromatic polyimide is a polymer having excellent heat resistance and refers to a high heat resistant resin prepared by solution polymerization of an aromatic dianhydride and an aromatic diamine or an aromatic diisocyanate to prepare a polyamic acid derivative and then dehydrating and dehydrating the polymer at a high temperature . Polyimide has excellent properties in heat resistance, chemical resistance, mechanical properties, electrical properties and dimensional stability, and is used in a wide range of electric / electronic materials such as aerospace, circuit board, and liquid crystal alignment film.

The polyimide does not dissolve in most of the solvents and has insolubility and / or insolubility characteristics that do not melt even at high temperatures. Due to these properties, it is prepared in the form of a polyamic acid dissolved in a solvent, and then it is made into a polyimide through a separate imidization process. In general, polyamic acid, a polyimide precursor, is prepared by adding dianhydride and diamine in the same molar ratio in a polar solvent.

In order to prepare such a polyimide, pyromellitic acid dianhydride (PMDA) or biphenyltetracarboxylic acid dianhydride (BPDA) or the like is used as an aromatic dianhydride component, and as an aromatic diamine component, oxydianiline (ODA ), p-phenylenediamine (p-PDA), m-phenylenediamine (m-PDA), methylenedianiline (MDA), and bisaminophenylhexafluoropropane (HFDA).

The physical properties of the polyimide are determined by the molecular weight. In order to obtain a high molecular weight, the equivalence ratio of the dianhydride and the diamine is important. Korean Patent Laid-Open Nos. 2014-0118386 and 2014-0112062 disclose a method in which a diamine is dissolved in a polar solvent, and dianhydride is then added to prepare a batch. In the case of such a batch-type production, since the equivalence ratio changes due to the variation in the amount of the charge during each addition, it is difficult to produce a uniform polymerized product, and the workability of the post-process such as the production of the film due to the difference in property between batches is also lowered.

It is an object of the present invention to provide a continuous process for preparing a polyimide precursor solution having a uniform amount of dianhydride and diamine,

Another object of the present invention is to provide a polyimide film having improved mechanical properties, excellent quality uniformity of the product, and excellent after-processability.

According to one aspect of the present invention, there is provided a method for preparing a diamine solution, comprising the steps of: dissolving a diamine compound in a polymerization solvent in a preparation of a diamine solution to prepare a diamine solution dissolved in an amount of 10 to 20 wt%;

Dissolving a dianhydride compound in a polymerization solvent in a dianhydride solution preparation to prepare a solution of the dianhydride dissolved at 10 to 20 wt%;

Adding the diamine solution and the dianhydride solution to the reaction tank at a flow rate of 2 L / min to 3 L / min and stirring to prepare a polyamic acid;

Transferring the polyamic acid to a storage tank; And

And then discharging the polyamic acid from the reservoir. When the step of transferring the polyamic acid to the reservoir is completed, 10 to 20 wt% of a diamine solution and 10 to 20 wt% of a dianhydride solution are introduced into the reactor Wherein the polyamic acid solution is stirred continuously to prepare a polyamic acid solution and the polyamic acid solution is transferred to the reservoir, and the flow rate of the lower portion of the reservoir solution is maintained constant. .

Another aspect of the present invention to attain the above object is a polyimide film using the polyimide precursor produced by the continuous production method of the polyimide precursor solution.

According to the continuous production method of the polyimide precursor solution according to the present invention, it is possible to uniformly introduce the dianhydride and the diamine used as the raw material, and the equivalence ratio can be easily controlled. In addition, polyamic acid having a constant physical property can be produced, and workability in a post-process can be improved, and mechanical properties and high quality of a product can be ensured at the time of film production.

1 is a schematic view of a continuous reactor for preparing a polyimide precursor solution according to an embodiment of the present invention.

Hereinafter, a method for producing a polyimide precursor solution according to the present invention will be described in detail with reference to examples and accompanying drawings.

The present invention relates to a process for continuously producing a polyimide precursor solution by continuously introducing dianhydride and diamine monomers dissolved in a polymerization solvent into the reactor at the same molar ratio.

1 is a schematic diagram of a continuous reactor 10 for producing a polyimide precursor solution according to an embodiment of the present invention. Referring to FIG. 1, in order to continuously prepare a polyimide precursor solution, a diamine compound is first dissolved in a polymerization solvent in the preparation of a first diamine solution preparation (11) to prepare a diamine solution dissolved at 10 to 20 wt%. Also, the dianhydride compound is dissolved in the polymerization solvent in the preparation of the first dianhydride solution preparation (13) to prepare a solution of the dianhydride dissolved at 10 to 20 wt%. Each of the prepared diamine solution and dianhydride solution was added to the polyimide precursor reaction tank 15 connected to the bottom of the first diamine solution preparation 11 and the first dianhydride solution preparation 13 and stirred Thereby producing polyamic acid which is a polyimide precursor. In order to continuously inject two kinds of monomers into the polyimide precursor reaction tank 15, the respective monomers are dissolved in a polymerization solvent at a constant concentration of 10 to 20 wt%, and then a diamine solution and a dianhydride solution are metered in. A metering pump is used to continuously supply the respective monomers to the polyimide precursor reaction tank 15 in a constant amount. In order to uniformly mix the two kinds of monomers in the polyimide precursor reaction tank 15, it is preferable to introduce a line mixer (not shown).

The flow rate of the diamine solution and the dianhydride solution into the polyimide precursor reaction tank 15 should be adjusted in consideration of the equivalence ratio according to the target properties of the polyimide precursor to be produced. Preferably, the flow rate of the diamine solution and the dianhydride solution into the polyimide precursor reaction tank 15 is 2 L / min to 3 L / min. When the flow rate is less than 2 L / min or exceeds 3 L / min, it is difficult to control the process steps and it is difficult to secure a polyimide precursor having uniform physical properties.

On the other hand, the inside of the polyimide precursor reaction tank 15 is replaced with nitrogen, thereby preventing the reactants from being oxidized in the inside. In addition, cooling water is allowed to flow through the cooling jacket 16 outside the polyimide precursor reaction tank 15 to maintain the temperature inside the polyimide precursor reaction tank 15 constant at 10 to 20 占 폚.

The prepared polyamic acid is then transferred to the polyimide precursor reservoir 17. When the transfer to the polyimide precursor reservoir 17 is completed, the diamine compound is dissolved in the polymerization solvent in the second diamine solution preparation 12 to prepare a diamine solution and a second dianhydride solution solution which are dissolved at 10 to 20 wt% 14, the dianhydride compound is dissolved in 10 to 20 wt% of the dianhydride solution, and the dianhydride solution is added to the polyimide precursor reaction tank 15 and stirred to continuously produce the polyamic acid. The produced polyamic acid is continuously transferred to the polyimide precursor reservoir 17 and finally discharged through the transfer line 19 installed at the bottom of the reservoir.

When the transfer to the polyimide precursor reservoir 17 is completed, the diamine compound is dissolved in the polymerization solvent in the first diamine solution preparation 11 to prepare a solution of the diamine solution and the first dianhydride solution dissolved in 10 to 20 wt% The process of dissolving the dianhydride compound in the polymerization solvent in the preparation (13), adding the dianhydride solution dissolved in 10 to 20 wt% to the polyimide precursor reaction tank (15) and stirring to prepare the polyamic acid is repeated do. The produced polyamic acid is continuously transferred to the polyimide precursor reservoir 17 and finally discharged through the transfer line 19 installed at the bottom of the reservoir.

The polyimide precursor reservoir 17 prevents the polyamic acid produced by replacing the inside with nitrogen to be oxidized. Further, cooling water is supplied to the cooling jacket 18 outside the polyimide precursor reservoir 17 to maintain the temperature inside the polyimide precursor reservoir 17 constant at 5 to 15 캜.

As described above, according to the present invention, the polyamic acid produced in the polyimide precursor reaction tank 15 can be continuously transferred to the polyimide precursor reservoir 17, so that the flow rate of the lower portion of the polyimide precursor reservoir 17 can be maintained constant.

Specific examples of the dianhydride compound include 4-4- (2,2,2-trifluoro-1-phenylethylidene) diphthalic anhydride (3FDAh), pyromellitic dianhydride (PMDA) , 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride (BPDA), 3,3', 4,4'-benzophenone tetracarboxylic dianhydride (TDA), 4,4'- (ODPA), 2,2'-bis- (3,4-dicarboxyphenyl) hexafluoropropanediamine hydrate (6FDA), cyclobutane-1,2,3,4-tetra (CBDA), cyclohexanediamine hydrate (CHDA), and the like, but are not limited thereto.

Specific examples of the diamine compound include 1,1-bis (4-aminophenyl) -1-phenyl-2,2,3-trifluoroethane, bistrifluoromethylbenzidine (TFDB), p- (p-PDA), m-phenylenediamine (m-PDA), bis (3-aminophenyl) sulfone (3-DDS), bis (4,4'-ODA), 3,3'-oxydianiline (3,3'-ODA), 2,2-bis ), Bisaminophenoxyphenylhexafluoropropane (DBOH), cyclohexanediamine (1,4-CHDA) and 2,2-bis (4- [3-aminophenoxy] phenyl) sulfone , But is not limited thereto.

The diamine compound and the dianhydride compound are dissolved in a polymerization solvent. The polymerization solvent may be any of those known in the art without limitation, but 1,3-dimethyl-2-imidazolidinone (DMI), N-methylpiperazine N-dimethylacetamide (DMAc), tetrahydrofuran (THF), N, Ndimethylformamide (DMF), dimethyl (N, N-dimethylacetamide) Dimethylsulfoxide (DMSO), cyclohexane, and acetonitrile, or a mixture thereof may be used.

According to the present invention, it is preferable that the concentrations of the dianhydride solution and the diamine solution in the polyimide precursor solution are 10 to 20 wt%, respectively. When the concentration of the dianhydride solution and / or the diamine solution is less than 10 wt%, the molecular weight of the polyimide precursor to be prepared is lowered. When the concentration of the dianhydride solution and / or the diamine solution exceeds 20 wt%, the viscosity of the precursor becomes too high, it's difficult.

When the diamine solution and the dianhydride solution are introduced into the polyimide precursor reaction tank 15, the solution should be continuously prepared at a constant concentration. At this time, the reaction in the polyimide precursor reaction tank 15 can be performed at 10 to 20 캜 for 2 to 12 hours, preferably at 10 캜 for about 4 hours. When the reaction is carried out for a longer time, the molecular weight of the polyimide precursor to be produced is lowered and the reaction efficiency is not increased, so that the reaction time is lengthened and the production efficiency may be lowered. In addition, when the reaction temperature is out of the above range, the polyimide precursor produced may be decomposed.

In addition, the flow rate of the lower portion of the polyimide precursor reservoir 17 is controlled according to the reaction time so as to have a constant flow rate. Below the polyimide precursor reservoir 17, a reservoir bottom transfer line 19 is connected and the flow rate of the produced polyamic acid transferred from the polyimide precursor reservoir 17 along the reservoir bottom transfer line 19 is 2 L / min To 3 L / min. If the flow rate is out of the above range, the flow velocity of the lower portion of the polyimide precursor reservoir 17 becomes uneven.

The diamine solution and the dianhydride solution may be reacted at a molar ratio of 1: 1 to 1: 1.02, preferably at a molar ratio of 1: 1.01. If the molar ratio of the diamine solution to the dianhydride solution is less than 1: 1, the molecular weight may be small and the heat resistance may be deteriorated. If the molar ratio exceeds 1: 1.02, a polymer having a desired molecular weight can not be obtained, And the viscosity may be lowered, which may make the coating and processing process difficult.

The diamine solution and the dianhydride solution may be used alone or in combination of two or more kinds of monomers.

The imidization step is a step of adding a catalyst to the precursor solution or heating to produce the polyimide as the final product. The imidization can be carried out by introducing the imidation catalyst into the precursor solution to advance the chemical imidization. The imidization catalyst may be any of those known in the art without limitation, and specifically includes acid anhydrides such as acetic anhydride, isoquinoline,? -Picoline, pyridine, azole, phosphine, malononitrile, Dimethylpiperidine, triethylamine, N, N, N, N'-tetramethylethylenediamine, triphenylphosphine, 4-dimethylaminopyridine, tripropylamine, tributylamine, N, 1,2,4-triazole, triisobutylamine, and the like.

The imidization can be carried out in combination with chemical imidization and thermal imidization. Specifically, a dehydrating agent and an imidization catalyst may be added to the precursor solution and heated to activate the dehydrating agent and the imidization catalyst, thereby partially imidizing the precursor solution. The imidization can proceed at 50 to 400 ° C and can be imidized at 90% or more by heating at 200 to 400 ° C for 30 minutes or more.

The imidization catalyst may be added to the precursor solution at a molar ratio of 1: 1 or more, preferably 1: 3 or more. If the imidization catalyst is added in an excess molar amount relative to the precursor solution, the dehydration reaction can be effectively induced, and the imidization can proceed smoothly and the imidization can proceed at a lower temperature, so that the thermal stability degradation due to the long- Can be prevented.

The present invention also provides a polyimide film using the polyimide precursor solution prepared by the method for producing the polyimide precursor solution.

The polyimide film may be produced by a conventional method known in the art. The polyimide film may be prepared from the precursor solution formed in the production of the polyimide of the present invention. Specifically, the precursor solution may be cast on a support and imidized to prepare a film. In addition, additives or fillers known in the art can be added during the casting. The imidization may be thermal imidization, chemical imidization, or thermal imidization and chemical imidization. Specifically, a polyimide film can be prepared by introducing a dehydrating agent and an imidation catalyst into a precursor solution, casting it, and then heating the mixture at a temperature ranging from room temperature to 150 ° C for 1 to 12 hours to imidize the polyimide film. At this time, the precursor solution may partially be imidized and contain a solid content, and the solid content is preferably 5 to 30% by weight based on the total precursor solution. In addition, the precursor solution may be thermally imidized by heating it for 1 minute to 4 hours while slowly heating the solution at a temperature of 40 to 400 ° C after casting on the support.

The polyimide film may be prepared by placing the precursor solution in a solvent such as water, methanol, or ethyl ether having a lower polarity than the polymerization solvent and precipitating to obtain a solid component, dissolving the precursor solution in a solvent, casting it on a support, and imidizing it. The solvent may be any solvent known in the art without limitation, and specific examples thereof include 1,3-dimethyl-2-imidazolidinone, N-methylpyrrolidinone, N, N-dimethylacetamide, Furan, N, N-dimethylformamide, dimethylsulfoxide, cyclohexane, and acetonitrile, or a mixture thereof.

The polyimide film manufacturing method may further include a heat treatment step of performing heat treatment for 1 to 30 minutes at a temperature of 150 to 450 DEG C under a predetermined tension. In the case of thermal imidization, the thermal history that occurs during the film forming process may lower the thermal stability of the final imide product, so that the thermal history can be removed through the heat treatment process.

Hereinafter, the present invention will be described in detail with reference to specific examples. The embodiments shown are merely illustrative of the present invention and are not intended to limit the scope of the present invention.

≪ Example 1: Preparation of continuous polyimide precursor solution >

Preparation of first diamine solution (11) 100 kg of dimethylacetamide was charged and 16.89 kg of oxydianiline was dissolved at 20 占 폚 to prepare a first diamine solution.

Preparation of first dianhydride solution (13) 100 kg of dimethylacetamide was charged and 18.40 kg of pyromellitic dianhydride (PMDA) was dissolved at 20 占 폚 to prepare a first dianhydride solution. The first diamine solution was introduced into the polyimide precursor reactor 15 at a flow rate of 2.40 L / min, and the inside of the reactor was stirred with the polyimide precursor reactor 15 at a flow rate of 2.62 L / min for the first dianhydride solution Respectively. In order to prevent the reactants from being oxidized, the interior of the polyimide precursor reactor 15 was replaced with nitrogen. The temperature inside the reactor was further stirred for 4 hours while being kept at 10 캜 by the cooling water in the cooling jacket 16 outside the reactor to prepare a 15 wt% polyamic acid solution. The prepared polyamic acid was transferred to the polyimide precursor reservoir 17. On the other hand, the second diamine solution preparation (12) was charged with 100 kg of dimethylacetamide and 16.89 kg of oxydianiline was dissolved at 20 占 폚 to prepare a second diamine solution. Preparation of Second Dianhydride Solution Preparation A second dianhydride solution was prepared by filling 14 kg of dimethylacetamide into 14 and dissolving 18.40 kg of pyromellitic dianhydride at 20 ° C. When the polyamic acid is transferred to the polyimide precursor reservoir 17, the second diamine solution is introduced into the polyimide precursor reactor 15 at a flow rate of 2.40 L / min and the second dianhydride solution is introduced into the polyimide precursor reservoir 17 at 2.62 L / min to the polyimide precursor reactor 15 while stirring the inside of the reactor. In order to prevent the reactants from being oxidized, the interior of the polyimide precursor reactor 15 was replaced with nitrogen. Further, the temperature inside the reactor was kept at 10 캜 by cooling water in the cooling jacket 16 outside the reactor, and stirred for 4 hours to prepare a 15 wt% polyamic acid solution. The prepared polyamic acid was transferred to a polyimide precursor reservoir 17, and physical properties of the polyamic acid continuously produced were measured and reported in Table 1 below.

≪ Examples 2 to 5: Preparation of continuous polyimide precursor solution >

The polyamic acid continuously prepared in Example 1 was further sampled four times at intervals of 4 hours, and the samples sampled at intervals of 4 hours were measured as Examples 2 to 5, respectively, .

≪ Comparative Example 1: Preparation of batch polyimide precursor solution >

200 kg of dimethylacetamide was charged into the batch type reactor, and 16.89 kg of oxydianiline was added thereto at 20 캜 in a solid state and stirred for 30 minutes to completely dissolve. Subsequently, 18.40 kg of pyromellitic dianhydride in a solid state was slowly added while stirring in the reactor while stirring. To prevent the reactants from being oxidized, the inside of the batch type reactor was replaced with nitrogen. The inside temperature of the reactor was kept at 10 캜 by cooling water flowing inside the cooling jacket outside the reactor, and the mixture was stirred for 4 hours to prepare a 15 wt% polyamic acid solution. These procedures were repeated five times to determine the respective Comparative Examples 1 to 5, and the physical properties of the polyimide precursor solution prepared in Comparative Examples 1 to 5 between the batches are shown in Table 1 below.

division Viscosity IV Solid content (%) Example 1 2,512 1.796 15.001 Example 2 2,507 1.792 15.003 Example 3 2,514 1.797 14.998 Example 4 2,502 1.790 14.999 Example 5 2,498 1.789 15.002 Property difference 14 0.007 0.005 Comparative Example 1 2,542 1.805 14.988 Comparative Example 2 2,488 1.785 15.059 Comparative Example 3 2,465 1.778 15.016 Comparative Example 4 2,510 1.795 14.992 Comparative Example 5 2,494 1.787 15.034 Property difference 77 0.027 0.071

Referring to Table 1, in the case of the continuous production method of the polyimide precursor solution according to Examples 1 to 5, a certain amount of dianhydride and diamine can be charged, so that the equivalence ratio can be easily controlled, Polyamic acid can be prepared. In the case of producing the polyimide precursor by batch method according to Comparative Examples 1 to 5, even when the same conditions are applied, the amounts of the dianhydride and the diamine are varied, resulting in a large difference in properties between batches due to the unbalance of the equivalence ratio.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, The facts will be apparent to those skilled in the art. Accordingly, the scope of protection of the present invention should be defined in the appended claims and their equivalents.

10: continuous reactor 11: preparation of first diamine solution preparation
12: preparation of second diamine solution preparation 13: preparation of first dianhydride solution preparation
14: preparation of second dianhydride solution tank
15: polyimide precursor reactor
16, 18: External cooling jacket
17: polyimide precursor reservoir
19: Transfer line

Claims (7)

Dissolving a diamine compound in a polymerization solvent in a diamine solution preparation to prepare a diamine solution dissolved at 10 to 20 wt%;
Dissolving a dianhydride compound in a polymerization solvent in a dianhydride solution preparation to prepare a solution of the dianhydride dissolved at 10 to 20 wt%;
Adding the diamine solution and the dianhydride solution to the reaction tank at a flow rate of 2 L / min to 3 L / min and stirring to prepare a polyamic acid;
Transferring the polyamic acid to a storage tank; And
And then discharging the polyamic acid from the reservoir. When the step of transferring the polyamic acid to the reservoir is completed, 10 to 20 wt% of a diamine solution and 10 to 20 wt% of a dianhydride solution are introduced into the reactor Stirring the polyamic acid to prepare a polyamic acid, and transferring the polyamic acid to the storage tank are continuously repeated so that the flow rate of the lower portion of the storage tank is kept constant.
The continuous method for producing a polyimide precursor solution according to claim 1, wherein cooling water is supplied to a cooling jacket outside the reaction vessel to maintain the temperature inside the reaction vessel at 5 to 15 占 폚. The method according to claim 1, wherein the diamine solution and the dianhydride solution are reacted at a molar ratio of 1: 1 to 1: 1.02.
The method according to claim 1, wherein the flow rate of the lower portion of the reservoir is maintained at 2 L / min to 3 L / min.
A method for producing a polyimide comprising the steps of: (a) heating a solution of the polyimide precursor prepared according to claim 1 to form an end product;
A polyimide produced by the method according to claim 5.
A polyimide film produced by using the polyimide according to claim 6.

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