Polyamic acid production system and production method, and polyimide production system and production method

Abstract

To provide a system and a method for producing a polyamic acid, which are capable of continuously and stably producing a polyamic acid and suppressing generation of air bubbles during production.SOLUTION: A system 1 for producing a polyamic acid includes: a first supply part which supplies a first solution A1 having a polyaddition-type first polymerizable compound dissolved therein; a second supply part which supplies a second solution having a polyaddition-type second polymerizable compound dissolved therein; a first mixing part 20 which mixes the first solution and the second solution to produce a first mixed solution; and a first reaction part 30 which stirs the first mixed solution in non-contact with a gas to make a polymerization reaction between the first polymerizable compound and the second polymerizable compound proceed, thereby producing a first polymerization solution having a polyamic acid dissolved therein.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a polyamic acid production system and method for producing polyamic acid, which is a precursor of polyimide, and a polyimide production system and method for producing polyimide, and more particularly to a polyamic acid production system and method capable of continuously producing polyamic acid, and a polyimide production system and method capable of continuously producing polyimide. [Background technology]

[0002] Batch production methods using a stirring tank have been known for some time as methods for producing polyamic acid. In batch production methods, the raw material solution poured into the stirring tank is stirred to cause the polymerization reaction. However, in this case, the gas phase at the top of the stirring tank is entrained in the liquid phase due to the stirring, resulting in the inclusion of air bubbles in the polymerization solution. When polyamic acid is cast to produce a polyimide film, any air bubbles remaining in the polymerization solution can cause film defects. The presence of air bubbles in the polymerization solution is a major issue in terms of quality.

[0003] In response to this, for example, an efficient degassing method for a polymerization solution has been proposed (see, for example, Patent Document 1). However, the method disclosed in Patent Document 1 requires a decompression facility, which may require high facility costs for implementation. Furthermore, this method requires a long degassing time, which may reduce productivity.

[0004] Furthermore, as a continuous method for producing polyamic acid, for example, a method for producing fine particles of polyamic acid (polyamic acid) using a tubular or other tubular reactor is known (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 2741208 [Patent Document 2] Japanese Patent Application Laid-Open No. 2006-249380 Summary of the Invention [Problem to be solved by the invention]

[0006] As described above, the batch production method using a stirring tank has a problem of bubble generation. In contrast, when a tubular reactor or other tubular reactor is used, as in the method disclosed in Patent Document 2, the problem of bubble generation is less likely to occur.

[0007] However, although the method disclosed in Patent Document 2 is suitable for producing fine particles of polyamic acid, when producing polyamic acid in a dissolved state in a solution, there is a problem in that it is difficult to stably obtain the desired polyamic acid.

[0008] An object of the present invention is to provide a polyamic acid production system and production method that enable continuous and stable production of polyamic acid while suppressing the generation of bubbles during production.Another object of the present invention is to provide a polyimide production system and production method that enable continuous and stable production of polyimide while suppressing the generation of bubbles during production. [Means for solving the problem]

[0009] Specific means for solving the above problems include the following embodiments. <1> A polyamic acid production system for producing a polyamic acid using as raw materials a first solution in which a first polymerizable compound with polyaddition properties is dissolved and a second solution in which a second polymerizable compound with polyaddition properties that undergoes polyaddition with the first polymerizable compound is dissolved, the system comprising: a first supply unit that supplies the first solution; a second supply unit that supplies the second solution; a first mixing section that mixes the first solution and the second solution by joining them together in a sealed tube without contacting them with gas, thereby generating a first mixed solution; a first reaction section in which the first mixed solution is stirred in a sealed tube without contact with gas, and a polymerization reaction between the first polymerizable compound and the second polymerizable compound is allowed to proceed, thereby producing a first polymerization solution in which a polyamic acid is dissolved; a first control unit that controls the supply of the first solution and / or the second solution, the first mixing section is a connection section between a tubular liquid delivery line through which the first solution is passed, a tubular liquid delivery line through which the second solution is passed, and a tubular liquid delivery line through which the first mixed solution is passed, The polyamic acid production system, wherein the first reaction section includes a static mixer.

[0010] <2> a first measurement unit that acquires one or more pieces of first reaction information related to a physical quantity and / or a composition of any one or more of the first solution, the second solution, the first mixed solution, and the first polymerization solution; The first control unit controls the supply in the first supply unit and / or the second supply unit based on the first reaction information acquired by the first measurement unit. <1> The polyamic acid production system according to claim 1.

[0011] <3> The first measurement unit is configured to include one or more selected from the group consisting of a viscometer, a pressure gauge, a pump pressure gauge, an absorption spectrometer, an infrared spectrometer, a near-infrared spectrometer, a density meter, a color difference meter, a refractometer, a spectrophotometer, a conductivity meter, a turbidity meter, and an X-ray fluorescence analyzer. <2> The polyamic acid production system according to claim 1.

[0012] <4> The first control unit controls a flow rate fluctuation rate of the first solution and / or the second solution so that a difference between a flow rate fluctuation rate of the first solution and a flow rate fluctuation rate of the second solution becomes small. <1> ~ <3> 10. The polyamic acid production system according to claim 9, wherein

[0013] <5> The first control unit controls the flow rate fluctuation of the first solution and the flow rate fluctuation of the second solution so as to be synchronized. <4> The polyamic acid production system according to claim 1.

[0014] <6> The first control unit controls the rate of change in flow rate of the first solution to be equal to or less than a first threshold value, and controls the rate of change in flow rate of the second solution to be equal to or less than a second threshold value. <1> ~ <5> 10. The polyamic acid production system according to claim 9, wherein

[0015] <7> One of the first polymerizable compound and the second polymerizable compound is a tetracarboxylic dianhydride, and the other is a diamine. <1> ~ <6> 10. The polyamic acid production system according to claim 9, wherein

[0016] <8> One of the first polymerizable compound and the second polymerizable compound is an acid anhydride-terminated or amino-terminated polyamic acid, and the other is a diamine or a tetracarboxylic dianhydride. <1> ~ <6> 10. The polyamic acid production system according to claim 9, wherein

[0017] <9> the polyamic acid contained in the first polymerization solution is an acid anhydride-terminated or amino-terminated polyamic acid, a third supply unit for supplying a third solution in which a diamine or a tetracarboxylic dianhydride to be polyadded to the acid anhydride-terminated or amino-terminated polyamic acid contained in the first polymerization solution is dissolved; a second mixing section that mixes the first polymerization solution and the third solution by joining them together in a sealed pipe without contacting them with gas, thereby producing a second mixed solution; a second reaction section for stirring the second mixed solution in a sealed tube without contact with gas, and promoting a polymerization reaction between the acid anhydride-terminated or amino-terminated polyamic acid from the first polymerization solution contained in the second mixed solution and the diamine or tetracarboxylic dianhydride from the third solution, thereby producing a second polymerized solution in which the polyamic acid is dissolved, the second mixing section is a connecting section between a tubular liquid feed line through which the first polymerization solution is passed, a tubular liquid feed line through which the third solution is passed, and a tubular liquid feed line through which the second mixed solution is passed, The second reaction section is configured to include a static mixer. <1> ~ <8> 10. The polyamic acid production system according to claim 9, wherein

[0018] <10> <1> ~ <9> a polyamic acid production system according to any one of the above items; an imidization unit that imidizes the polyamic acid produced by the polyamic acid production system.

[0019] <11> A method for producing a polyamic acid using a first solution containing a first polymerizable compound with polyaddition properties dissolved therein and a second solution containing a second polymerizable compound with polyaddition properties dissolved therein as raw materials, the method comprising the steps of: a first supplying step of supplying the first solution; a second supplying step of supplying the second solution; a first mixing step of mixing the first solution and the second solution by joining them together in a sealed tube without contacting them with gas to produce a first mixed solution; a first reaction step in which the first mixed solution is stirred in a sealed tube without contact with gas, and a polymerization reaction between the first polymerizable compound and the second polymerizable compound is allowed to proceed, thereby producing a first polymerization solution in which a polyamic acid is dissolved; a first control step of controlling the supply of the first solution and / or the second solution, In the first mixing step, the first solution and the second solution are mixed at a connecting portion between a tubular liquid feed line through which the first solution is passed, a tubular liquid feed line through which the second solution is passed, and a tubular liquid feed line through which the first mixed solution is passed, to generate the first mixed solution; In the first reaction step, the first mixed solution is stirred by passing it through a static mixer to produce the first polymerized solution.

[0020] <12> a first measurement step of acquiring one or more pieces of first reaction information relating to a physical quantity and / or a composition of any one or more of the first solution, the second solution, the first mixed solution, and the first polymerization solution; In the first control step, the supply in the first supply step and / or the second supply step is controlled based on the first reaction information acquired in the first measurement step. <11> 1. A method for producing the polyamic acid according to claim 1.

[0021] <13> In the first measurement step, the first reaction information is acquired by one or more devices selected from the group consisting of a viscometer, a pressure meter, a pump pressure meter, an absorption spectrometer, an infrared spectrometer, a near-infrared spectrometer, a density meter, a color difference meter, a refractometer, a spectrophotometer, a conductivity meter, a turbidity meter, and an X-ray fluorescence analyzer. <12> 1. A method for producing the polyamic acid according to claim 1.

[0022] <14> In the first control step, the flow rate fluctuation rate of the first solution and / or the second solution is controlled so that a difference between the flow rate fluctuation rate of the first solution and the flow rate fluctuation rate of the second solution becomes small. <11> ~ <13> 1. A method for producing the polyamic acid according to claim 1.

[0023] <15> In the first control step, the flow rate fluctuation of the first solution and the flow rate fluctuation of the second solution are controlled so as to be synchronized. <14> 1. A method for producing the polyamic acid according to claim 1.

[0024] <16> In the first control step, a flow rate fluctuation rate of the first solution is controlled to be equal to or less than a first threshold value, and a flow rate fluctuation rate of the second solution is controlled to be equal to or less than a second threshold value. <11> ~ <15> 1. A method for producing the polyamic acid according to claim 1.

[0025] <17> One of the first polymerizable compound and the second polymerizable compound is a tetracarboxylic dianhydride, and the other is a diamine. <11> ~ <16> 1. A method for producing the polyamic acid according to claim 1.

[0026] <18> One of the first polymerizable compound and the second polymerizable compound is an acid anhydride-terminated or amino-terminated polyamic acid, and the other is a diamine or a tetracarboxylic dianhydride. <11> ~ <16> 1. A method for producing the polyamic acid according to claim 1.

[0027] <19> the polyamic acid contained in the first polymerization solution is an acid anhydride-terminated or amino-terminated polyamic acid, a third supplying step of supplying a third solution in which a diamine or tetracarboxylic dianhydride to be polyadded to the acid anhydride-terminated or amino-terminated polyamic acid contained in the first polymerization solution is dissolved; a second mixing step of mixing the first polymerization solution and the third solution by joining them together in a sealed pipe without contacting with gas to produce a second mixed solution; a second reaction step of stirring the second mixed solution in a sealed tube without contact with gas, and causing a polymerization reaction between the acid anhydride-terminated or amino-terminated polyamic acid from the first polymerization solution contained in the second mixed solution and the diamine or tetracarboxylic dianhydride from the third solution, thereby producing a second polymerized solution in which the polyamic acid is dissolved, In the second mixing step, the first polymerization solution and the third solution are mixed at a connecting portion between a tubular liquid feed line through which the first polymerization solution is passed, a tubular liquid feed line through which the third solution is passed, and a tubular liquid feed line through which the second mixture solution is passed, to generate the second mixture solution; In the second reaction step, the second mixed solution is stirred by passing it through a static mixer to produce the second polymerized solution. <11> ~ <18> 1. A method for producing the polyamic acid according to claim 1.

[0028] <20> <11> ~ <19> a polyamic acid production step of producing a polyamic acid by the production method according to any one of the above items; an imidization step of imidizing the polyamic acid produced in the polyamic acid production step. [Effects of the Invention]

[0029] According to the present invention, it is possible to provide a polyamic acid production system and a polyamic acid production method that are capable of continuously and stably producing polyamic acid and that are capable of suppressing the generation of bubbles during production. Also, according to the present invention, it is possible to provide a polyimide production system and a polyimide production method that are capable of continuously and stably producing polyimide and that are capable of suppressing the generation of bubbles during production. [Brief explanation of the drawings]

[0030] [Figure 1] FIG. 1 is a diagram showing a polyamic acid production system according to a first embodiment. [Figure 2] FIG. 1 is a flow diagram illustrating a method for producing a polyamic acid according to a first embodiment. [Figure 3] FIG. 10 is a diagram showing a polyamic acid production system according to a second embodiment. [Figure 4] FIG. 10 is a flow diagram illustrating a method for producing a polyamic acid according to a second embodiment. [Figure 5] FIG. 10 is a diagram showing a polyamic acid production system according to a third embodiment. [Figure 6] FIG. 10 is a block diagram of a polyamic acid production system according to a third embodiment. [Figure 7] FIG. 10 is a flow chart illustrating the operation of the polyamic acid production system according to the third embodiment. [Figure 8] FIG. 10 is a flowchart illustrating another operation of the polyamic acid production system according to the third embodiment. [Figure 9] FIG. 10 is a diagram showing a polyamic acid production system according to a fourth embodiment. [Figure 10] FIG. 10 is a block diagram of a polyamic acid production system according to a fourth embodiment. [Figure 11] FIG. 10 is a flow chart illustrating the operation of the polyamic acid production system according to the fourth embodiment. [Figure 12]FIG. 10 is a flowchart illustrating another operation of the polyamic acid production system according to the fourth embodiment. [Figure 13] FIG. 10 is a diagram showing a polyamic acid production system according to a fifth embodiment. [Figure 14] 13A and 13B are diagrams showing flow rate waveforms before and after control in the fifth embodiment. [Figure 15] FIG. 10 is a flow chart illustrating the operation of the polyamic acid production system according to the fifth embodiment. [Figure 16] FIG. 10 is a diagram showing a polyamic acid production system according to a sixth embodiment. [Figure 17] FIG. 10 is a flow chart illustrating the operation of the polyamic acid production system according to the sixth embodiment. [Figure 18] FIG. 10 is a diagram showing a polyamic acid production system according to a seventh embodiment. [Figure 19] 13A and 13B are diagrams showing flow rate waveforms before and after control in the seventh embodiment. [Figure 20] FIG. 13 is a flow chart illustrating the operation of the polyamic acid production system according to the seventh embodiment. [Figure 21] FIG. 13 is a diagram showing a polyamic acid production system according to an eighth embodiment. [Figure 22] FIG. 13 is a flowchart illustrating the operation of the polyamic acid production system according to the eighth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0031] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0032] First Embodiment A polyamic acid production system according to the first embodiment will be described with reference to Figures 1 and 2. The first embodiment is an example of a polyamic acid production system having a single-stage reaction section.

[0033] First, an outline of a polyamic acid production system 1 according to a first embodiment will be described with reference to FIG. The polyamic acid production system 1 is a system for producing a polyamic acid using, as raw materials, a first solution A1 in which a first polymerizable compound having polyaddition properties is dissolved, and a second solution A2 in which a second polymerizable compound having polyaddition properties that undergoes polyaddition with the first polymerizable compound is dissolved.

[0034] In the following, as an example, a case where one of the first polymerizable compound and the second polymerizable compound is a tetracarboxylic dianhydride and the other is a diamine will be described. More specifically, a case where the first polymerizable compound contained in the first solution A1 is a tetracarboxylic dianhydride and the second polymerizable compound contained in the second solution A2 is a diamine will be described.

[0035] The tetracarboxylic dianhydride is not particularly limited, and the same tetracarboxylic dianhydride as that used in conventional polyimide synthesis can be used. Specific examples of the tetracarboxylic dianhydride include 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, pyromellitic dianhydride, 1,3-bis(2,3-dicarboxyphenoxy)benzene dianhydride, 1,4-bis(2,3-dicarboxyphenoxy)benzene dianhydride, 2,3,3',4'-benzophenonetetracarboxylic dianhydride, 2,2',3,3'-benzophenonetetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, 2,2',6,6'-biphenyltetracarboxylic dianhydride, and naphthalene-1,2,4, Examples of the tetracarboxylic acid dianhydride include aromatic tetracarboxylic acid dianhydrides such as 1,5-tetracarboxylic acid dianhydride, anthracene-2,3,6,7-tetracarboxylic acid dianhydride, phenanthrene-1,8,9,10-tetracarboxylic acid dianhydride, and 2,2-bis(4-hydroxyphenyl)propanedibenzoate-3,3',4,4'-tetracarboxylic acid dianhydride; aliphatic tetracarboxylic acid dianhydrides such as butane-1,2,3,4-tetracarboxylic acid dianhydride; alicyclic tetracarboxylic acid dianhydrides such as cyclobutane-1,2,3,4-tetracarboxylic acid dianhydride; and heterocyclic tetracarboxylic acid dianhydrides such as thiophene-2,3,4,5-tetracarboxylic acid dianhydride and pyridine-2,3,5,6-tetracarboxylic acid dianhydride. One type of tetracarboxylic acid dianhydride may be used alone, or two or more types may be used in combination.

[0036] The solvent used for the first solution A1 is one that dissolves tetracarboxylic dianhydride and polyamic acid. Specific examples of solvents include amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, and acetanilide; cyclic ester solvents such as γ-butyrolactone; chain ester solvents such as ethyl acetate; ketone solvents such as 2-propanone, 3-pentanone, acetone, and methyl ethyl ketone; ether solvents such as tetrahydrofuran and dioxolane; alcohol solvents such as methanol, ethanol, and isopropanol; and aromatic hydrocarbon solvents such as toluene and xylene. Among these, amide solvents, cyclic ester solvents, and ether solvents, which have high solubility for polyamic acid, are preferred. The solvents may be used alone or in combination. For example, by mixing a highly polar alcoholic solvent with a solvent in which polyamic acid has a relatively low solubility, such as acetone, ethyl acetate, methyl ethyl ketone, toluene, or xylene, the solubility of polyamic acid can be improved.

[0037] The first solution A1 may contain a small amount of a tertiary amine such as trimethylamine or triethylamine in order to increase the solubility of the tetracarboxylic dianhydride or to increase the reactivity with the diamine.

[0038] The diamine is not particularly limited, and the same diamines as those used in conventional polyimide synthesis can be used. Specific examples of the diamine include 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 4,4'-bis(4-aminophenoxy)biphenyl, 1,4'-bis(4-aminophenoxy)benzene, 1,3'-bis(4-aminophenoxy)benzene, o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylsulfone, 3,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, 4,4'-methylene-bis(2-chloroaniline), 3,3'-dimethyl-4,4'-diaminobiphenyl, 4,4'- Examples of the diamine include aromatic diamines such as diaminodiphenyl sulfide, 2,6-diaminotoluene, 2,4-diaminochlorobenzene, 1,2-diaminoanthraquinone, 1,4-diaminoanthraquinone, 3,3'-diaminobenzophenone, 3,4'-diaminobenzophenone, 4,4'-diaminobenzophenone, and 4,4'-diaminobibenzyl; aliphatic diamines such as 1,2-diaminoethane, 1,4-diaminobutane, tetramethylenediamine, and 1,10-diaminododecane; alicyclic diamines such as 1,4-diaminocyclohexane, 1,2-diaminocyclohexane, bis(4-aminocyclohexyl)methane, and 4,4'-diaminodicyclohexylmethane; and heterocyclic diamines such as 3,4-diaminopyridine. The diamines may be used singly or in combination of two or more.

[0039] The solvent for the second solution A2 is one that dissolves diamines and polyamic acids. Specific examples of solvents include amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, and acetanilide; cyclic ester solvents such as γ-butyrolactone; chain ester solvents such as ethyl acetate; ketone solvents such as 2-propanone, 3-pentanone, acetone, and methyl ethyl ketone; ether solvents such as tetrahydrofuran and dioxolane; alcohol solvents such as methanol, ethanol, and isopropanol; and aromatic hydrocarbon solvents such as toluene and xylene. Among these, amide solvents, cyclic ester solvents, and ether solvents, which have high solubility for polyamic acids, are preferred. The solvents may be used alone or in combination. For example, by mixing a highly polar alcoholic solvent with a solvent in which polyamic acid has a relatively low solubility, such as acetone, ethyl acetate, methyl ethyl ketone, toluene, or xylene, the solubility of polyamic acid can be improved.

[0040] As shown in FIG. 1, the polyamic acid production system 1 is configured to produce polyamic acid by mixing raw materials, a first solution A1 and a second solution A2, in a first mixing section 20 to produce a first mixed solution B, and then causing a polymerization reaction in a first reaction section 30 to produce a first polymerization solution C.

[0041] Here, the polyamic acid production system 1 has a tubular liquid transfer line L that connects, in a sealed state, a first tank 11 and a second tank 12 described below to the first cushion tank 40. This allows the polyamic acid production system 1 to continuously produce polyamic acid without generating bubbles in the first mixed solution B or the first polymerization solution C.

[0042] Next, a specific configuration of the polyamic acid production system 1 will be described. 1, the polyamic acid production system 1 includes a first tank 11, a second tank 12, a first supply pump 15 (first supply unit), a second supply pump 16 (second supply unit), a first mixing unit 20, a first reaction unit 30, a first cushion tank 40, and a liquid transfer line L. The liquid transfer line L includes a first liquid transfer unit L1, a second liquid transfer unit L2, and a third liquid transfer unit L3.

[0043] The first tank 11 contains a first solution A1 in which a first polymerizable compound having polyaddition properties is dissolved. In this embodiment, the first tank 11 contains a first solution A1 in which a tetracarboxylic dianhydride is dissolved. The first solution A1 contained in the first tank 11 is supplied to the first mixing section 20 via a first liquid supply section L1.

[0044] The second tank 12 contains a second solution A2 in which a second polymerizable compound capable of polyaddition with the first polymerizable compound is dissolved. In this embodiment, the second tank 12 contains the second solution A2 in which a diamine is dissolved. The second solution A2 contained in the second tank 12 is supplied to the first mixing unit 20 via the second liquid supply unit L2.

[0045] The first supply pump 15 (first supply unit) supplies the first solution A1 contained in the first tank 11 to the first mixing unit 20. The first supply pump 15 supplies the first solution A1 at a predetermined flow rate. For example, the first supply pump 15 is adjusted to supply the first solution A1 under conditions that allow polyamic acid with desired properties to be obtained.

[0046] The second supply pump 16 (second supply unit) supplies the second solution A2 contained in the second tank 12 to the first mixing unit 20. The second supply pump 16 supplies the second solution A2 at a predetermined flow rate. For example, the second supply pump 16 is adjusted to supply the second solution A2 under conditions that allow polyamic acid with desired properties to be obtained.

[0047] The first mixing section 20 is disposed downstream of the first supply pump 15 and the second supply pump 16. The first mixing section 20 mixes the first solution A1 and the second solution A2 to produce a first mixed solution B. The first mixing section 20 is configured with a confluence valve that merges the first solution A1 supplied by the first supply pump 15 and the second solution A2 supplied by the second supply pump 16.

[0048] The first reaction section 30 is a section where a polymerization reaction between the first polymerizable compound and the second polymerizable compound contained in the first mixed solution B proceeds. In the first reaction section 30, the polymerization reaction between the first polymerizable compound and the second polymerizable compound contained in the first mixed solution B proceeds gradually, and a first polymerization solution C is obtained.

[0049] The first reaction section 30 is composed of a double pipe extending in a predetermined direction, and has a first reaction stirring section 31 disposed on the radially inner side and a first reaction temperature adjusting section 32 disposed on the radially outer side. The first reaction section 30 is configured so that the first mixed solution B flows therethrough for a desired residence time.

[0050] The first reaction stirring unit 31 stirs the first mixed solution B, which is a mixture of the first solution A1 and the second solution A2, without contacting it with gas. In this embodiment, the first reaction stirring unit 31 stirs the first mixed solution B, which has been adjusted to a temperature suitable for the polymerization reaction by the first reaction temperature adjusting unit 32, without contacting it with gas.

[0051] The first reaction stirring section 31 is configured to include, for example, a static mixer such as a static mixer, a nozzle, or an orifice, or a driven mixer such as a centrifugal pump, a volute pump, or an in-line mixer with stirring blades, preferably a static mixer, and more preferably a static mixer. Note that a pipe with a twist tape inserted therein (see, for example, [Figure 19] of JP 2003-314982 A) can also achieve the same stirring promotion effect as a static mixer, but a static mixer is preferred because it provides a stronger stirring promotion effect.

[0052] The static mixer is not particularly limited, and examples thereof include Kenics mixer type, Sulzer SMV type, Sulzer SMX type, Tray Hi-mixer type, Komax mixer type, Lightnin mixer type, Ross ISG type, Bran & Lube mixer type, etc. Among these, Kenics mixer type static mixers are more preferred because they have a simple structure and therefore no dead space.

[0053] The first reaction temperature adjustment section 32 is a piping section disposed radially outside the first reaction stirring section 31. The first reaction temperature adjustment section 32 adjusts (e.g., cools) the temperature of the first mixed solution B flowing through the first reaction stirring section 31 to a desired temperature condition. In the first reaction temperature adjustment section 32, the first mixed solution B is adjusted to a temperature suitable for the polymerization reaction and is then flowed through the first reaction stirring section 31.

[0054] The first cushion tank 40 contains the first polymerization solution C from the first reaction section 30. The first cushion tank 40 serves as a tank containing a raw material solution when, for example, polyamic acid is imidized to produce polyimide.

[0055] The polyamic acid production system 1 in this embodiment may be part of a polyimide production system for producing polyimide. In this case, the polyimide production system further includes an imidization unit that imidizes the polyamic acid. The imidization unit (not shown) imidizes the polyamic acid by, for example, a thermal imidization method that thermally dehydrates and ring-closes the polyamic acid, or a chemical imidization method that uses a dehydrating agent and an imidization accelerator.

[0056] When the polyamic acid production system 1 in this embodiment is part of a polyimide production system for producing polyimide, the first cushion tank 40 may be omitted and the polyamic acid may be sent from the first reaction section 30 to the imidization section. However, as described above, it is preferable to temporarily store the polyamic acid in the first cushion tank 40.

[0057] Next, a method for producing a polyamic acid according to the first embodiment will be described with reference to FIG. As shown in FIG. 2, in the first supply step ST11, the first supply pump 15 supplies the first solution A1 contained in the first tank 11 to the first mixing section 20. In parallel with this, the second supply pump 16 supplies the second solution A2 contained in the second tank 12 to the first mixing section 20 in a second supply step ST12.

[0058] Next, in the first mixing step ST13, the first mixing section 20 merges and mixes the first solution A1 supplied by the first supply pump 15 and the second solution A2 supplied by the second supply pump 16 to produce a first mixed solution B.

[0059] Next, in the first reaction step ST14, the first reaction unit 30 causes a polymerization reaction between the first polymerizable compound and the second polymerizable compound contained in the first mixed solution B to proceed, thereby producing a first polymerized solution C in which polyamic acid is dissolved. Specifically, the first reaction stirring unit 31 stirs the first mixed solution B, which has been adjusted to a temperature suitable for the polymerization reaction by the first reaction temperature adjustment unit 32, without contacting it with gas, thereby causing the polymerization reaction to proceed and producing the first polymerized solution C. When the first reaction stirring unit 31 is a stationary mixer such as a static mixer, the first mixed solution B is stirred simply by being passed through it.

[0060] Here, for example, the method for producing polyamic acid in this embodiment may be part of a method for producing polyimide, in which case the method for producing polyimide further includes an imidization step of imidizing polyamic acid.

[0061] The polyamic acid production system 1 of this embodiment has the following advantages. The polyamic acid production system 1 includes a first reaction section 30 that stirs a first mixed solution B, in which a first solution A1 and a second solution A2 are mixed, without contact with gas, to produce a first polymerization solution C in which polyamic acid is dissolved. Such a polyamic acid production system 1 enables continuous and stable production of polyamic acid and can suppress the generation of bubbles during production. Specifically, the polyamic acid production system 1 enables continuous and stable production of the first polymerization solution C in which polyamic acid is dissolved, and can suppress the generation of bubbles in the first polymerization solution C.

[0062] Furthermore, in the polyamic acid production system 1, the first reaction section 30 may be configured to include a static mixer. For example, in the polyamic acid production system 1, a static mixer can be disposed as the first reaction stirring section 31 constituting the first reaction section 30. As a result, according to the polyamic acid production system 1, the first mixed solution B can be stirred simply by passing it through the first reaction stirring section 31.

[0063] In this embodiment, one of the first polymerizable compound and the second polymerizable compound is a tetracarboxylic dianhydride and the other is a diamine. However, this is not limiting. For example, one of the first polymerizable compound and the second polymerizable compound may be an acid anhydride-terminated or amino-terminated polyamic acid (prepolymer), and the other may be a diamine or tetracarboxylic dianhydride. In this case, when one of the first polymerizable compound and the second polymerizable compound is an acid anhydride-terminated polyamic acid, the other is a diamine. Furthermore, when one of the first polymerizable compound and the second polymerizable compound is an amino-terminated polyamic acid, the other is a tetracarboxylic dianhydride.

[0064] In addition, in this embodiment, the first reaction section 30 is described as being configured as a double pipe including the first reaction stirring section 31 and the first reaction temperature adjustment section 32, but the present invention is not limited to this. For example, the first reaction section 30 may be configured as a single pipe including only the first reaction stirring section 31, and this first reaction stirring section 31 may be immersed in a temperature adjustment liquid.

[0065] Furthermore, in the present embodiment, the first tank 11 and the second tank 12 to the first cushion tank 40 are connected in a sealed state by a tubular liquid feed line L, but the present invention is not limited to this. For example, in order to prevent bubbles from being generated in the first polymerization solution C, it is sufficient that at least the first reaction section 30 is capable of stirring the solution without contacting the gas. However, as described above, it is more preferable that the solution does not come into contact with the gas throughout the entire liquid feed line L.

[0066] Furthermore, in this embodiment, the case where there is one reaction section (first reaction section) that stirs the first mixed solution B without contacting it with gas has been described, but the present invention is not limited to this. For example, the reaction section that stirs the first mixed solution B without contacting it with gas may include a mixing and stirring section and a reaction and stirring section that is disposed downstream of the mixing and stirring section and continues therefrom. The mixing and stirring section and the reaction and stirring section can be configured with a static mixer, similar to the first reaction section 30. In this case, the mixing and stirring section stirs the first mixed solution B without contacting it with gas, and the reaction and stirring section further stirs the solution stirred in the mixing and stirring section without contacting it with gas to produce the first polymerization solution C. This polyamic acid production system can further improve the quality and yield of the produced polyamic acid.

[0067] Second Embodiment Next, a polyamic acid production system according to a second embodiment will be described with reference to Figures 3 and 4. The second embodiment is an example of a polyamic acid production system having two stages of treatment sections (reaction sections).

[0068] First, a polyamic acid production system 1A according to the second embodiment will be described with reference to FIG. As shown in FIG. 3, the polyamic acid production system 1A includes a first processing unit K1 and a second processing unit K2.

[0069] The first processing unit K1 has the same configuration as the polyamic acid production system 1 in the first embodiment, and therefore a detailed description thereof will be omitted in this embodiment. The configuration requirements and operation of the first processing unit K1 can be similar to those described in the first embodiment. However, the first polymerization solution C produced in the first processing unit K1 contains an acid anhydride-terminated or amino-terminated polyamic acid (prepolymer).

[0070] The second processing unit K2 further advances the polymerization reaction using the first polymerization solution C produced by the first processing unit K1 (the polyamic acid production system 1 in the first embodiment) and the third solution A3 as raw materials to produce polyamic acid (having a larger molecular weight). The second processing unit K2 has the same basic configuration as the first processing unit K1, but differs from the first processing unit K1 in that the second processing unit K2 produces polyamic acid using the first polymerization solution C produced by the first processing unit K1 as raw material.

[0071] The second processing unit K2 includes a third tank 13, a third supply pump 17 (third supply unit), a second mixing unit 50, a second reaction unit 60, a second cushion tank 70, and a part of the liquid transfer line L. The part of the liquid transfer line L includes a fourth liquid transfer unit L4 and a fifth liquid transfer unit L5.

[0072] The third tank 13 contains a third solution A3 in which a diamine or tetracarboxylic dianhydride is dissolved, which undergoes polyaddition to the acid anhydride-terminated or amino-terminated polyamic acid contained in the first polymerization solution C. The third solution A3 contained in the third tank 13 is supplied to the second mixing section 50 via the fourth liquid supply section L4.

[0073] In the following, as an example, a case will be described in which the first polymerization solution C contains a polyamic acid having an acid anhydride group at its terminal, and the third solution A3 contains a diamine.

[0074] The third supply pump 17 (third supply unit) supplies the third solution A3 contained in the third tank 13 to the second mixing unit 50. The third supply pump 17 supplies the third solution A3 at a predetermined flow rate. For example, the third supply pump 17 is adjusted to supply the third solution A3 under conditions that result in polyamic acid with desired properties. The flow rate of the third supply pump 17 can be set depending on the properties and composition of the first polymerization solution C. The flow rate of the third supply pump 17 can also be set depending on the reaction rate, etc., of the first polymerization solution C. In other words, the flow rate of the third supply pump 17 can be adjusted to achieve the target properties, composition, and reaction rate.

[0075] The second mixing section 50 is disposed downstream of the first reaction section 30 and the third supply pump 17 in the first processing section K1. The second mixing section 50 mixes the first polymerization solution C from the first reaction section 30 with the third solution A3 from the third supply pump 17 to produce a second mixed solution D. The second mixing section 50 is configured with a confluence valve that merges the first polymerization solution C from the first reaction section 30 with the third solution A3 from the third supply pump 17.

[0076] The second reaction section 60 is composed of a double pipe extending in a predetermined direction, and has a second reaction stirring section 61 arranged on the radially inner side and a second reaction temperature adjusting section 62 arranged on the radially outer side. The second reaction section 60 is formed so that the second mixed solution D flows therethrough for a desired residence time.

[0077] The second reaction stirring section 61 stirs the second mixed solution D, which is a mixture of the first polymerization solution C and the third solution A3, without contacting it with gas. In this embodiment, the second reaction stirring section 61 stirs the second mixed solution D, which has been adjusted to a temperature suitable for the polymerization reaction by the second reaction temperature adjusting section 62, without contacting it with gas.

[0078] The second reaction stirring section 61 is configured to include, for example, a static mixer such as a static mixer, a nozzle, or an orifice, or a driven mixer such as a centrifugal pump, a volute pump, or an in-line mixer with stirring blades, preferably a static mixer, and more preferably a static mixer. As mentioned above, a tube with a twist tape inserted therein can also achieve the same stirring promotion effect as a static mixer, but a static mixer is preferred because it can achieve a stronger stirring promotion effect.

[0079] The static mixer is not particularly limited, and examples thereof include Kenics mixer type, Sulzer SMV type, Sulzer SMX type, Tray Hi-mixer type, Komax mixer type, Lightnin mixer type, Ross ISG type, Bran & Lube mixer type, etc. Among these, Kenics mixer type static mixers are more preferred because they have a simple structure and therefore no dead space.

[0080] The second reaction temperature adjustment unit 62 is a piping unit arranged radially outside the second reaction stirring unit 61. The second reaction temperature adjustment unit 62 adjusts (e.g., cools) the temperature of the second mixed solution D flowing through the second reaction stirring unit 61 to a desired temperature condition. In the second reaction temperature adjustment unit 62, the second mixed solution D is adjusted to a temperature suitable for the polymerization reaction, and is flowed through the second reaction stirring unit 61.

[0081] The second cushion tank 70 contains the second polymerization solution E from the second reaction section 60. The second cushion tank 70 serves as a tank containing a raw material solution when, for example, polyamic acid is imidized to produce polyimide.

[0082] The polyamic acid production system 1A in this embodiment may be part of a polyimide production system for producing polyimide. In this case, the polyimide production system further includes an imidization unit that imidizes the polyamic acid. The imidization unit (not shown) imidizes the polyamic acid by, for example, a thermal imidization method that thermally dehydrates and ring-closes the polyamic acid, or a chemical imidization method that uses a dehydrating agent and an imidization accelerator.

[0083] When the polyamic acid production system 1 in this embodiment is part of a polyimide production system that produces polyimide, the second cushion tank 70 may be omitted, and the polyamic acid may be sent from the second reaction section 60 to the imidization section. However, as described above, it is preferable to temporarily store the polyamic acid in the second cushion tank 70.

[0084] Next, a method for producing a polyamic acid according to a second embodiment will be described with reference to FIG. Here, ST21 to ST24 in this embodiment have the same content as ST11 to ST14 in the first embodiment, so detailed description thereof will be omitted. The contents of ST21 to ST24 in this embodiment can be derived from the descriptions of ST11 to ST14 in the first embodiment.

[0085] As shown in FIG. 4, in the third supply step ST25, the third supply pump 17 supplies the third solution A3 contained in the third tank 13 to the second mixing section . In parallel, the first polymerization solution C from the first reaction section 30 is supplied to the second mixing section 50.

[0086] Next, in the second mixing step ST26, the second mixing section 50 merges and mixes the first polymerization solution C from the first reaction section 30 with the third solution A3 supplied by the third supply pump 17 to produce a second mixed solution D.

[0087] Next, in the second reaction step ST27, the second reaction unit 60 promotes a polymerization reaction between the acid anhydride-terminated polyamic acid from the first polymerization solution C contained in the second mixed solution D and the diamine from the third solution A3, thereby producing a second polymerization solution E in which the polyamic acid is dissolved. Specifically, the second reaction stirring unit 61 promotes the polymerization reaction by stirring the second mixed solution D, which has been adjusted to a temperature suitable for the polymerization reaction by the second reaction temperature adjustment unit 62, without contacting it with gas, thereby producing the second polymerization solution E. When the second reaction stirring unit 61 is a stationary mixer such as a static mixer, the second mixed solution D is stirred simply by being passed through it.

[0088] Here, for example, the method for producing polyamic acid in this embodiment may be part of a method for producing polyimide, in which case the method for producing polyimide further includes an imidization step of imidizing polyamic acid.

[0089] The polyamic acid production system 1A of this embodiment has the following advantages in addition to the advantages of the first embodiment described above. The polyamic acid production system 1A has a first processing unit K1 and a second processing unit K2, and is configured to carry out a polymerization reaction in two stages. This makes it easier to achieve the target reaction rate and the like, and further improves the quality and yield of the produced polyamic acid.

[0090] In addition to the first reaction section 30, the polyamic acid production system 1A also includes a second reaction section 60 that stirs a second mixed solution D, obtained by mixing the first polymerization solution C and the third solution A3, without contacting the solution with gas, to produce a second polymerization solution E in which polyamic acid is dissolved. Such a polyamic acid production system 1A enables continuous and stable production of polyamic acid and can suppress the generation of bubbles during production. Specifically, the polyamic acid production system 1A enables continuous and stable production of the second polymerization solution E in which polyamic acid is dissolved, and can suppress the generation of bubbles in the second polymerization solution E.

[0091] In this embodiment, the first polymerization solution C contains an acid anhydride-terminated polyamic acid, and the third solution A3 contains a diamine. However, the present invention is not limited to this. For example, the first polymerization solution C may contain an amino-terminated polyamic acid, and the third solution A3 may contain a tetracarboxylic dianhydride.

[0092] In addition, in this embodiment, the second reaction section 60 is described as being configured as a double pipe consisting of the second reaction stirring section 61 and the second reaction temperature adjustment section 62, but the present invention is not limited to this. For example, the second reaction section 60 may be configured as a single pipe consisting of only the second reaction stirring section 61, and this second reaction stirring section 61 may be immersed in a temperature adjustment liquid.

[0093] Furthermore, in the present embodiment, the first tank 11 and the second tank 12 are connected to the second cushion tank 70 in a sealed state by a tubular liquid transfer line L, but the present invention is not limited to this. For example, in order to prevent bubbles from being generated in the second polymerization solution E, it is sufficient that at least the first reaction section 30 and the second reaction section 60 are capable of stirring the solution without contacting the gas. However, as described above, it is more preferable that the solution does not come into contact with the gas throughout the entire liquid transfer line L.

[0094] Furthermore, in this embodiment, the case where there is one reaction section (second reaction section) that stirs the second mixed solution D without contacting the gas has been described, but the present invention is not limited thereto. For example, the reaction section that stirs the second mixed solution D without contacting the gas may include a mixing and stirring section and a reaction and stirring section that is disposed downstream of the mixing and stirring section and continues therefrom. The mixing and stirring section and the reaction and stirring section can be configured to include a static mixer, similar to the second reaction section 60. In this case, the mixing and stirring section stirs the second mixed solution D without contacting the gas, and the reaction and stirring section further stirs the solution stirred in the mixing and stirring section without contacting the gas, thereby producing the second polymerization solution E. Such a polyamic acid production system can further improve the quality and yield of the produced polyamic acid.

[0095] Third Embodiment Next, a polyamic acid production system according to a third embodiment will be described with reference to Figures 5 to 8. The third embodiment is an example of a polyamic acid production system having a single stage of treatment section (reaction section), and is an example of a system capable of controlling the supply amount of a raw material solution based on measurement information from a measurement section.

[0096] First, a polyamic acid production system 1B according to the third embodiment will be described with reference to Fig. 5. However, a description of the same configuration as in the first embodiment will be omitted.

[0097] The polyamic acid production system 1B has a first measurement unit that acquires one or more pieces of first reaction information related to the physical quantity and / or composition of one or more of the first solution A1, the second solution A2, the first mixed solution B, and the first polymerization solution C (hereinafter referred to as "first measurement object"). In this embodiment, the polyamic acid production system 1B has a plurality of first measurement units. More specifically, the polyamic acid production system 1B has a pump pressure measurement unit 81, first differential pressure measurement units 91 and 92, and a first viscosity measurement unit 111.

[0098] The pump pressure measuring unit 81 acquires, as first reaction information, information on the pump pressure of the first supply pump 15. The pump pressure measuring unit 81 acquires, as first reaction information, for example, numerical information on the pump pressure, or information on voltage or current values.

[0099] The first differential pressure measuring units 91 and 92 acquire information on the differential pressure between the inlet and outlet of the first reaction unit 30 (the differential pressure between the upstream side and the downstream side) as first reaction information.

[0100] The first viscosity measuring unit 111 acquires, as first reaction information, viscosity information of the first polymerization solution C. Since the viscosity increases as the polymerization reaction progresses, the viscosity information is effective information as first reaction information.

[0101] The first measurement unit is not limited to the measurement unit (type of physical quantity and / or composition, measurement method) of this embodiment. The first measurement unit is configured to include one or more selected from the group consisting of, for example, a viscometer, a pressure gauge, a pump pressure gauge, an absorption spectrometer, an infrared spectrometer, a near-infrared spectrometer, a densitometer, a color difference meter, a refractometer, a spectrophotometer, a conductivity meter, a turbidity meter, and an X-ray fluorescence analyzer.

[0102] The first measurement section acquires one or more pieces of first reaction information relating to the physical quantity and / or composition of the first measurement object, and outputs the acquired first reaction information to a first control section 200B, which will be described later.

[0103] Next, a block diagram of a polyamic acid production system 1B according to the third embodiment will be described with reference to FIG. As shown in FIG. 6, the polyamic acid production system 1B includes a plurality of first measurement units (first measurement unit group), a first control unit 200B, a first storage unit 300B, and a first supply pump 15 and a second supply pump 16 to be controlled.

[0104] As described above, the first measurement unit acquires one or more pieces of first reaction information related to the physical quantity and / or composition of the first measurement object. The polyamic acid production system 1B has a plurality of first measurement units. More specifically, the polyamic acid production system 1B has a pump pressure measurement unit 81, first differential pressure measurement units 91 and 92, and a first viscosity measurement unit 111. Here, the first reaction information includes not only numerical information such as measured values ​​of physical quantities and / or compositions, but also electrical signals that change in response to the physical quantities and / or compositions.

[0105] The first control unit 200B controls the supply from the first supply pump 15 and / or the second supply pump 16 based on the first reaction information acquired by the first measurement unit. The first control unit 200B has a determination unit 210B, a selection unit 220B, and an instruction unit 230B.

[0106] The determination unit 210B determines whether or not the measurement values ​​relating to the physical quantity and / or composition of the first measurement object are within a predetermined allowable range based on the first reaction information from the first measurement unit. The determination unit 210B acquires the first reaction information from the first measurement unit based on the measurement interval stored in the measurement interval information storage unit 310B described later, and determines whether or not the acquired first reaction information is within a predetermined allowable range based on the allowable range information stored in the allowable range information storage unit 320B described later.

[0107] When there are multiple pieces of first reaction information that the judgment unit 210B judges to be outside the acceptable range, the selection unit 220B selects the first reaction information to be prioritized in control based on priority information from the priority information storage unit 340B described below. Furthermore, when the first reaction information determined by the determination unit 210B to be outside the allowable range is specific information, for example, when the first reaction information is viscosity information, the selection unit 220B selects other first reaction information to be supplemented to determine the control content based on supplemental information from the supplemental information storage unit 330B (described later). For example, when the first reaction information is viscosity information, even if it is determined from the viscosity measurement that the polymerization reaction is insufficient, it may not be possible to determine whether to increase the first solution A1 or the second solution A2. The selection unit 220B selects other first reaction information to be supplemented for the viscosity information based on the supplemental information.

[0108] The instruction unit 230B controls the supply from the first supply pump 15 and / or the second supply pump 16 based on control information from a control information storage unit 350B, which will be described later. The instruction unit 230B acquires control information, which is control content stored in the control information storage unit 350B, based on information from the determination unit 210B and the selection unit 220B. Then, the instruction unit 230B controls the first supply pump 15 and / or the second supply pump 16 based on the acquired control information.

[0109] The first storage unit 300B includes a measurement interval information storage unit 310B, an allowable range information storage unit 320B, a complementary information storage unit 330B, a priority information storage unit 340B, and a control information storage unit 350B.

[0110] The measurement interval information storage unit 310B stores measurement interval information relating to the interval at which the first control unit 200B (determination unit 210B) acquires the first reaction information from the first measurement unit. The measurement interval is set for each first measurement unit (first reaction information). The measurement interval is also set according to the position at which the first measurement unit is located (upstream or downstream position on the liquid transfer line L).

[0111] The acceptable range information storage unit 320B stores information on the acceptable range (e.g., range of measurement values, signal strength, etc.) corresponding to the quality, etc. required to obtain the desired polymer for each piece of first reaction information acquired by each first measurement unit.

[0112] The complementary information storage unit 330B stores information that can identify the first reaction information to be selected as complementary information when the various first reaction information (various first measurement units) is specific first reaction information (specific measurement unit). The complementary information storage unit 330B stores the specific first reaction information and the first reaction information to be complementary in association with each other. The complementary information storage unit 330B stores, for example, information indicating that viscosity information is to be complemented with specific first reaction information.

[0113] When the determining unit 210B determines that a plurality of pieces of first reaction information (first measurement units) are outside the allowable range, the priority information storage unit 340B stores information (for example, information on the order of priority) on the first reaction information that should be prioritized. The priority information storage unit 340B stores, for example, information indicating that viscosity information is prioritized.

[0114] The control information storage unit 350B stores information on the control content corresponding to the content of the first reaction information determined to be outside the allowable range. The control information storage unit 350B stores, for example, control information on the content to increase / decrease the supply amount of the first supply pump 15 and / or the second supply pump 16.

[0115] Next, the operation of the polyamic acid production system 1B in the third embodiment will be described with reference to Fig. 7. Here, the control using viscosity information as the first reaction information will be described. As shown in FIG. 7, in step ST31, the determination unit 210B acquires viscosity information, which is first reaction information, from the first viscosity measurement unit 111, which is the first measurement unit.

[0116] Next, in step ST32, the determination unit 210B determines whether or not the acquired viscosity information is within a predetermined allowable range, based on the allowable range information stored in the allowable range information storage unit 320B. Then, when the determining unit 210B determines that the viscosity information (viscosity value) is within the predetermined range (YES), the supply amount of the second supply pump 16 is not changed (step ST33). Moreover, when the determining unit 210B determines that the viscosity information (viscosity value) is not within the predetermined range (NO), the process proceeds to step ST34.

[0117] Next, in step ST34, the selection unit 220B acquires complementary information, which is information on the first reaction information (type) that complements the viscosity information, from the complementary information storage unit 330B.

[0118] Next, in step ST35, the instruction unit 230B acquires control information such as control conditions from the control information storage unit 350B based on the content of the viscosity information and the content of the first reaction information identified by the complementary information. Then, based on the acquired control information, the instruction unit 230B controls the second supply pump 16. If the control content is to increase the supply amount in the second supply pump 16 (increase), the instruction unit 230B controls the second supply pump 16 to increase the supply amount (step ST36). Furthermore, when the control content is to decrease the supply amount in the second supply pump 16 (decrease), the instructing unit 230B controls the second supply pump 16 to decrease the supply amount (step ST37).

[0119] Next, the first control unit 200B enters a standby state (step ST38). Here, the first control unit 200B acquires viscosity information from the first viscosity measuring unit 111 at predetermined intervals based on the measurement interval information stored in the measurement interval information storage unit 310B.

[0120] Next, another operation of the polyamic acid production system 1B in the third embodiment will be described with reference to Fig. 8. Here, control using a plurality of pieces of first reaction information will be described. As shown in FIG. 8, in step ST41, the determination unit 210B acquires first reaction information from each measurement unit of the first measurement unit group.

[0121] Next, in step ST42, the judgment section 210B judges whether or not all of the acquired first reaction information is within a predetermined tolerance range, based on the tolerance information stored in the tolerance information storage section 320B. Then, when the determining unit 210B determines that all of the first reaction information is within the predetermined range (YES), the supply amount of the second supply pump 16 is not changed (step ST43). Furthermore, when determining that not all of the first reaction information is within the predetermined range (one or more pieces of first reaction information are outside the predetermined range) (NO), determining section 210B advances the process to step ST44.

[0122] Next, in step ST44, if there are multiple pieces of first reaction information that fall outside the predetermined range (YES), the judgment unit 210B proceeds to step ST45. If there are not multiple pieces of first reaction information that fall outside the predetermined range (NO), the judgment unit 210B proceeds to step ST46.

[0123] Next, in step ST45, the selection section 220B selects the first reaction information (type) with the highest priority based on the priority information recorded in the priority information storage section 340B.

[0124] Next, in step ST46, the instruction section 230B acquires control information such as control conditions from the control information storage section 350B based on the content of the first reaction information that is outside the predetermined range. Then, based on the acquired control information, the instruction unit 230B controls the second supply pump 16. If the control content is to increase the supply amount in the second supply pump 16 (increase), the instruction unit 230B controls the second supply pump 16 to increase the supply amount (step ST47). Furthermore, if the control content is to decrease the supply amount in the second supply pump 16 (decrease), the instruction unit 230B controls the second supply pump 16 to decrease the supply amount (step ST48).

[0125] Next, the first control unit 200B enters a standby state (step ST49). Here, the first control unit 200B acquires first reaction information from each measurement unit of the first measurement unit group at predetermined intervals based on the measurement interval information stored in the measurement interval information storage unit 310B.

[0126] The polyamic acid production system 1B of this embodiment has the following advantages in addition to the advantages of the first embodiment described above. The polyamic acid production system 1B includes a first measurement unit that acquires first reaction information related to the physical quantity and / or composition of a first measurement object, and a first control unit that controls the supply from the first supply pump 15 and / or the second supply pump 16 based on the first reaction information acquired by the first measurement unit. The polyamic acid production system 1B described above makes it possible to continuously and stably obtain a desired polyamic acid. Furthermore, the polyamic acid production system 1B also makes it possible to reduce the out-of-spec rate in the continuous production of polyamic acid.

[0127] Furthermore, in the polyamic acid production system 1B, the first measurement unit includes one or more devices selected from the group consisting of a viscometer, a pressure gauge, a pump pressure gauge, an absorbance meter, an infrared spectrometer, a near-infrared spectrometer, a densitometer, a colorimeter, a refractometer, a spectrophotometer, a conductivity meter, a turbidity meter, and an X-ray fluorescence analyzer. This allows the polyamic acid production system 1B to control the supply from the first supply pump 15 and / or the second supply pump 16 based on the multiple types of first reaction information acquired by the multiple types of first measurement units, thereby more suitably adjusting the polymerization reaction.

[0128] <Fourth embodiment> Next, a polyamic acid production system according to a fourth embodiment will be described with reference to Figures 9 to 12. The fourth embodiment is an example of a polyamic acid production system having two stages of treatment sections (reaction sections), and is an example of a system that can control the supply amount of a raw material solution based on measurement information from a measurement section.

[0129] First, a polyamic acid production system 1C according to the fourth embodiment will be described with reference to FIG. As shown in FIG. 9, the polyamic acid production system 1C includes a first processing unit K3 and a second processing unit K4.

[0130] The first processing unit K3 has the same configuration as that of the polyamic acid production system 1B in the third embodiment, and therefore a detailed description thereof will be omitted in this embodiment. Also, a detailed description of the second processing unit K4 having the same configuration as that in the second embodiment will be omitted in this embodiment.

[0131] In addition to the first measurement unit described above, the polyamic acid production system 1C has a second measurement unit that acquires one or more pieces of second reaction information related to the physical quantity and / or composition of one or more of the first polymerization solution C, the third solution A3, the second mixed solution D, and the second polymerization solution E (hereinafter referred to as "second measurement targets"). In this embodiment, the polyamic acid production system 1C has a plurality of second measurement units. More specifically, the polyamic acid production system 1C has second differential pressure measurement units 93 and 94, a second viscosity measurement unit 112, a first absorbance measurement unit 101, and a second absorbance measurement unit 102.

[0132] The second differential pressure measuring units 93 and 94 acquire information on the differential pressure between the inlet and outlet of the second reaction unit 60 (the differential pressure between the upstream side and the downstream side) as second reaction information.

[0133] The second viscosity measuring unit 112 acquires, as second reaction information, viscosity information of the second polymerization solution E. Since the viscosity increases as the polymerization reaction progresses, the viscosity information is effective as second reaction information.

[0134] The first absorbance measurement unit 101 acquires information on the absorbance of a specific wavelength in the first polymerization solution C as second reaction information. The second absorbance measurement unit 102 acquires information on the absorbance of the second polymerization solution E at a specific wavelength as second reaction information. Here, the difference in absorbance can be calculated from the absorbance information acquired by the first absorbance measurement unit 101 and the absorbance information acquired by the second absorbance measurement unit 102.

[0135] The second measurement unit is not limited to the measurement unit of this embodiment (type of physical quantity and / or composition, measurement method), and may include one or more devices selected from the group consisting of a viscometer, a pressure gauge, a pump pressure gauge, an absorption spectrometer, an infrared spectrometer, a near-infrared spectrometer, a densitometer, a color difference meter, a refractometer, a spectrophotometer, a conductivity meter, a turbidity meter, and an X-ray fluorescence analyzer.

[0136] The second measurement section acquires one or more pieces of second reaction information relating to the physical quantity and / or composition of the second measurement object, and outputs the acquired second reaction information to a second control section 200C, which will be described later.

[0137] Next, a block diagram of a polyamic acid production system 1C according to the fourth embodiment will be described with reference to FIG. As shown in FIG. 6, the polyamic acid production system 1C includes a plurality of first measurement units (first measurement unit group), a plurality of second measurement units (second measurement unit group), a second control unit 200C, a second memory unit 300C, and a first supply pump 15, a second supply pump 16, and a third supply pump 17, which are to be controlled.

[0138] As described above, the second measurement unit acquires one or more pieces of second reaction information related to the physical quantity and / or composition of the second measurement object. The polyamic acid production system 1C has multiple second measurement units. More specifically, the polyamic acid production system 1C has second differential pressure measurement units 93 and 94, a second viscosity measurement unit 112, a first absorbance measurement unit 101, and a second absorbance measurement unit 102. Here, the second reaction information includes not only numerical information such as measured values ​​of physical quantities and / or compositions, but also electrical signals that change in response to the physical quantities and / or compositions.

[0139] The second control unit 200C controls the supply from the third supply pump 17 based on the first reaction information acquired by the first measurement unit and / or the second reaction information acquired by the second measurement unit. Here, the second control unit 200C also has the function of the first control unit, and is therefore configured to be able to control the supply from the first supply pump 15 and / or the second supply pump 16 based on the first reaction information acquired by the first measurement unit. Hereinafter, components with the same names as those in the third embodiment have the functions described in the third embodiment in addition to the functions described below in this embodiment.

[0140] The second control unit 200C has a determination unit 210C, a selection unit 220C, and an instruction unit 230C.

[0141] The determination unit 210C determines whether or not the measured values ​​relating to the physical quantities and / or compositions of the first and / or second measurement objects are within a predetermined allowable range based on the first and / or second reaction information. The determination unit 210C acquires the first and / or second reaction information from the first and / or second measurement units based on the measurement interval stored in the measurement interval information storage unit 310C described later, and determines whether or not the acquired first and / or second reaction information is within a predetermined allowable range based on the allowable range information stored in the allowable range information storage unit 320C described later.

[0142] When there are multiple pieces of first reaction information and / or second reaction information that the judgment unit 210C judges to be outside the acceptable range, the selection unit 220C selects the first reaction information and / or second reaction information to be prioritized in control based on priority information from the priority information storage unit 340C described below.

[0143] Furthermore, when the first reaction information and / or the second reaction information determined by the determination unit 210C to be outside the allowable range is specific information, for example, when the first reaction information and / or the second reaction information is viscosity information, the selection unit 220C selects other first reaction information and / or second reaction information to be supplemented to determine the control content based on supplemental information from the supplemental information storage unit 330C (described later). For example, when the first reaction information and / or the second reaction information is viscosity information, even if the viscosity measurement value indicates that the polymerization reaction is insufficient, it may not be possible to determine whether to increase the first polymerization solution C or the third solution A3. The selection unit 220C selects other first reaction information and / or second reaction information to be supplemented for the viscosity information based on the supplemental information.

[0144] The instruction unit 230C controls the supply from the third supply pump 17 based on control information from a control information storage unit 350C, which will be described later. The instruction unit 230C acquires control information, which is the control content stored in the control information storage unit 350C, based on information from the determination unit 210C and the selection unit 220C. Then, the instruction unit 230C controls the third supply pump 17 based on the acquired control information.

[0145] Next, the second storage unit 300C has a measurement interval information storage unit 310C, an allowable range information storage unit 320C, a supplementary information storage unit 330C, a priority information storage unit 340C, and a control information storage unit 350C. Hereinafter, components with the same names as those in the third embodiment have the functions described in the third embodiment in addition to the functions described in the present embodiment below.

[0146] The measurement interval information storage unit 310C stores measurement interval information relating to the interval at which the second control unit 200C (determination unit 210C) acquires the first reaction information from the first measurement unit and the interval at which the second reaction information is acquired from the second measurement unit. The measurement interval is set for each first measurement unit (first reaction information). The measurement interval is also set according to the position at which the first measurement unit is arranged (upstream or downstream position on the liquid feed line L). Similarly, the measurement interval is set for each second measurement unit (second reaction information). The measurement interval is also set according to the position at which the second measurement unit is arranged (upstream or downstream position on the liquid feed line L).

[0147] The tolerance information storage unit 320C stores, for each piece of first reaction information acquired by each first measurement unit, information on tolerance ranges (e.g., ranges of measurement values, signal strength, etc.) corresponding to the quality, etc. required to obtain a desired polymer. In addition, the tolerance information storage unit 320C stores, for each piece of second reaction information acquired by each second measurement unit, information on tolerance ranges (e.g., ranges of measurement values, signal strength, etc.) corresponding to the quality, etc. required to obtain a desired polymer.

[0148] The complementary information storage unit 330C stores information that can identify the first reaction information and / or second reaction information to be selected as complementary information when the various first reaction information (various first measurement units) and / or various second reaction information (various second measurement units) are specific first reaction information (specific measurement unit) and / or specific second reaction information (specific measurement unit). The complementary information storage unit 330C stores the specific first reaction information and / or second reaction information in association with the first reaction information and / or second reaction information to be complementary. The complementary information storage unit 330C stores, for example, information indicating that viscosity information is to be complemented with specific first reaction information and / or second reaction information.

[0149] When the determination unit 210C determines that a plurality of pieces of first reaction information (first measurement unit) and / or second reaction information (second measurement unit) are outside the allowable range, the priority information storage unit 340C stores information (e.g., information on the order of priority) regarding the first reaction information and / or second reaction information that should be prioritized. The priority information storage unit 340C stores, for example, information indicating that viscosity information is prioritized.

[0150] The control information storage unit 350C stores information on the control content corresponding to the first reaction information and / or the second reaction information determined to be outside the allowable range. The control information storage unit 350C stores, for example, control information on the content for increasing / decreasing the supply amount of the third supply pump 17.

[0151] Next, the operation of the polyamic acid production system 1C according to the fourth embodiment will be described with reference to Fig. 11. Here, control using viscosity information as the second reaction information will be described. As shown in FIG. 11, in step ST51, the determination unit 210C acquires viscosity information, which is second reaction information, from the second viscosity measurement unit 112, which is the second measurement unit.

[0152] Next, in step ST52, the determination unit 210C determines whether the acquired viscosity information is within a predetermined allowable range based on the allowable range information stored in the allowable range information storage unit 320C. Then, when the determining unit 210C determines that the viscosity information (viscosity value) is within the predetermined range (YES), the supply amount of the third supply pump 17 is not changed (step ST53). Moreover, when the determining unit 210C determines that the viscosity information (viscosity value) is not within the predetermined range (NO), the process proceeds to step ST54.

[0153] Subsequently, in step ST54, the selection unit 220C acquires complementary information, which is information on the first reaction information (type) and / or the second reaction information (type) that complements the viscosity information, from the complementary information storage unit 330C.

[0154] Next, in step ST55, the instruction unit 230C acquires control information such as control conditions from the control information memory unit 350C based on the contents of the viscosity information and the contents of the first reaction information and / or second reaction information identified by the complementary information. Then, based on the acquired control information, the instruction unit 230C controls the third supply pump 17. If the control content is to increase the supply amount in the third supply pump 17 (increase), the instruction unit 230C controls the third supply pump 17 to increase the supply amount (step ST56). Furthermore, if the control content is to decrease the supply amount in the third supply pump 17 (decrease), the instruction unit 230C controls the third supply pump 17 to decrease the supply amount (step ST57).

[0155] Next, the second control unit 200C enters a standby state (step ST58). Here, the second control unit 200C acquires viscosity information from the second viscosity measuring unit 112 at predetermined intervals based on the measurement interval information stored in the measurement interval information storage unit 310C.

[0156] Next, another operation of the polyamic acid production system 1C in the fourth embodiment will be described with reference to Fig. 12. Here, control using a plurality of pieces of first reaction information and second reaction information will be described. As shown in FIG. 12, in step ST61, the determination unit 210C acquires first reaction information from each measurement unit of the first measurement unit group, and acquires second reaction information from each measurement unit of the second measurement unit group.

[0157] Next, in step ST62, the judgment section 210C judges whether or not all of the acquired first reaction information and second reaction information are within a predetermined tolerance range, based on the tolerance information stored in the tolerance information storage section 320C. Then, when the determining unit 210C determines that all of the first reaction information and second reaction information are within the predetermined range (YES), the supply amount of the third supply pump 17 is not changed (step ST63). Furthermore, when the judgment section 210C judges that not all of the first reaction information and second reaction information are within the predetermined range (one or more pieces of reaction information are outside the predetermined range) (NO), the process proceeds to step ST64.

[0158] Next, in step ST64, if there is a plurality of pieces of reaction information that are out of the predetermined range (YES), the judgment unit 210C proceeds to step ST65. If there is not a plurality of pieces of reaction information that are out of the predetermined range (NO), the judgment unit 210C proceeds to step ST66.

[0159] Next, in step ST65, the selection section 220C selects the first reaction information (type) and / or the second reaction information (type) with the highest priority based on the priority information.

[0160] Next, in step ST66, the instruction section 230C acquires control information such as control conditions from the control information storage section 350C based on the content of the reaction information that is outside the predetermined range. Then, based on the acquired control information, the instruction unit 230C controls the third supply pump 17. If the control content is to increase the supply amount in the third supply pump 17 (increase), the instruction unit 230C controls the third supply pump 17 to increase the supply amount (step ST67). Furthermore, if the control content is to decrease the supply amount in the third supply pump 17 (decrease), the instruction unit 230C controls the third supply pump 17 to decrease the supply amount (step ST68).

[0161] Next, the second control unit 200C enters a standby state (step ST69). Here, the second control unit 200C acquires the first reaction information from each first measurement unit and the second reaction information from each second measurement unit at predetermined intervals based on the measurement interval information stored in the measurement interval information storage unit 310C.

[0162] The polyamic acid production system 1C of this embodiment has the following advantages in addition to the advantages of the second embodiment described above. The polyamic acid production system 1C includes a first measurement unit that acquires first reaction information related to the physical quantity and / or composition of a first measurement object, a second measurement unit that acquires second reaction information related to the physical quantity and / or composition of a second measurement object, and a first control unit that controls supply from one or more of the first supply pump 15, the second supply pump 16, and the third supply pump 17 based on the first reaction information acquired by the first measurement unit and / or the second reaction information acquired by the second measurement unit. The polyamic acid production system 1C allows for continuous and stable production of a desired polyamic acid. Furthermore, the polyamic acid production system 1C allows for a reduced out-of-spec rate during continuous polyamic acid production.

[0163] In addition, in the polyamic acid production system 1C, the first measurement unit and the second measurement unit are configured to include one or more selected from the group consisting of a viscometer, a pressure gauge, a pump pressure gauge, an absorbance meter, an infrared spectrometer, a near-infrared spectrometer, a densitometer, a colorimeter, a refractometer, a spectrophotometer, a conductivity meter, a turbidity meter, and an X-ray fluorescence analyzer. This allows the polyamic acid production system 1C to control the supply from one or more of the first supply pump 15, the second supply pump 16, and the third supply pump 17 based on the multiple types of first reaction information obtained by the multiple types of first measurement units and / or the multiple types of second reaction information obtained by the multiple types of second measurement units, thereby more suitably adjusting the polymerization reaction.

[0164] (Specific examples of control) Specific examples of control in the polyamic acid production system 1B and the polyamic acid production system 1C will be described below, although the present invention is not limited to the following specific examples.

[0165] (1) Example 1 Assume that the viscosity of the first polymerization solution C at the outlet of the first reaction section 30 is lower than the set value. An in-line viscometer is installed at the outlet of the first reaction section 30, and viscosity information of the first polymerization solution C is acquired over time. To increase the viscosity, the flow rate ratio may be controlled so that the tetracarboxylic dianhydride / diamine ratio approaches an equimolar ratio.

[0166] (2) Example 2 Assume that the viscosity of the first polymerization solution C at the outlet of the first reaction section 30 is lower than the set value. Two pressure gauges are installed near the outlet of the first reaction section 30, and viscosity information of the first polymerization solution C is obtained over time using the differential pressure. To increase the viscosity, the flow rate ratio should be controlled so that the tetracarboxylic dianhydride / diamine ratio approaches an equimolar ratio.

[0167] (3) Example 3 Assume that the viscosity of the first polymerization solution C at the outlet of the first reaction section 30 is lower than the set value. An in-line viscometer is installed at the outlet of the first reaction section 30, and viscosity information of the first polymerization solution C is acquired over time. Furthermore, an in-line absorption spectrometer is installed at the outlet of the first reaction section 30, and absorbance information of the first polymerization solution C is acquired over time. Then, based on the absorbance information detected when there is excess monomer, it is determined whether the tetracarboxylic dianhydride or the diamine is in excess. To increase the viscosity, the flow rate ratio may be controlled so that the tetracarboxylic dianhydride / diamine ratio approaches an equivalence ratio.

[0168] (4) Example 4 Assume that the viscosity of the first polymerization solution C at the outlet of the first reaction section 30 is lower than the set value. An in-line viscometer is installed at the outlet of the first reaction section 30, and viscosity information of the first polymerization solution C is acquired over time. Furthermore, an in-line infrared spectrometer is installed at the outlet of the first reaction section 30, and infrared spectroscopic information of the first polymerization solution C is acquired over time. Then, based on the infrared spectroscopic information detected when there is excess monomer, it is determined whether the tetracarboxylic dianhydride or the diamine is in excess. To increase the viscosity, the flow rate ratio may be controlled so that the tetracarboxylic dianhydride / diamine ratio approaches an equimolar ratio.

[0169] (5) Example 5 Assume that the viscosity of the first polymerization solution C at the outlet of the first reaction section 30 is lower than the set value. Two pressure gauges are installed near the outlet of the first reaction section 30, and viscosity information of the first polymerization solution C is obtained over time using differential pressure. Furthermore, an in-line absorption spectrometer is installed at the outlet of the first reaction section 30, and absorbance information of the first polymerization solution C is obtained over time. Then, based on the absorbance information detected when there is excess monomer, it is determined whether the tetracarboxylic dianhydride or the diamine is in excess. To increase the viscosity, the flow rate ratio may be controlled so that the tetracarboxylic dianhydride / diamine ratio approaches equivalence.

[0170] (6) Example 6 Assume that the viscosity of the first polymerization solution C at the outlet of the first reaction section 30 is lower than the set value. Two pressure gauges are installed near the outlet of the first reaction section 30, and viscosity information of the first polymerization solution C is obtained over time using differential pressure. Furthermore, an inline infrared spectrometer is installed at the outlet of the first reaction section 30, and infrared spectroscopic information of the first polymerization solution C is obtained over time. Then, based on absorbance information detected when there is excess monomer, it is determined whether the tetracarboxylic dianhydride or the diamine is in excess. To increase the viscosity, the flow rate ratio may be controlled so that the tetracarboxylic dianhydride / diamine ratio approaches equivalence.

[0171] (7) Example 7 Assume that the viscosity of the first polymerization solution C at the outlet of the first reaction section 30 is lower than the set value. An in-line viscometer is installed at the outlet of the first reaction section 30, and viscosity information of the first polymerization solution C is acquired over time. Next, the flow rate of either the first solution A1 or the second solution A2 is reduced to check whether the viscosity increases or decreases. Then, the correlation between the increase or decrease in flow rate and the increase or decrease in viscosity is checked, and the flow rate ratio is controlled in the direction that increases the viscosity.

[0172] (8) Example 8 A calibration curve is created for the viscosity of the polyamic acid solution serving as the first solution A1 and the tetracarboxylic dianhydride / diamine ratio in the first solution A1. By determining the tetracarboxylic dianhydride / diamine ratio that results in the desired viscosity in advance, the amount of second solution A2 to be added to the first solution A1 can be calculated. An in-line viscometer is installed at the outlet of the first supply pump 15, and viscosity information on the first solution A1 is acquired over time. Using the obtained viscosity information on the first solution A1, the amount of second solution A2 required to achieve the desired viscosity at the outlet of the first reaction section 30 is calculated, and the supply rate of second solution A2 is controlled to achieve the calculated flow rate.

[0173] (9) Example 9 Assume that the viscosity of the second polymeric solution E at the outlet of the second reaction section 60 is lower than the set value. An in-line viscometer is installed at the outlet of the second reaction section 60, and viscosity information of the second polymeric solution E is obtained over time. Furthermore, an in-line absorbance meter is installed at the outlet of the second reaction section 60, and absorbance information of the second polymeric solution E is obtained over time. Furthermore, an in-line viscometer is installed at the outlet of the first reaction section 30, and viscosity information of the first polymeric solution C is obtained over time. Furthermore, an in-line absorbance meter is installed at the outlet of the first reaction section 30, and absorbance information of the first polymeric solution C is obtained over time.

[0174] If the viscosity of the first polymerization solution C at the outlet of the first reaction section 30 deviates from the set value, it is determined whether the tetracarboxylic dianhydride or the diamine is in excess based on absorbance information detected when there is excess monomer. Then, the flow rate of the second solution A2 is controlled so that the tetracarboxylic dianhydride / diamine ratio approaches the set value for the viscosity of the first polymerization solution C. On the other hand, when the viscosity of the first polymerization solution C at the outlet of the first reaction section 30 indicates a set value, it is determined whether the tetracarboxylic dianhydride or the diamine is in excess based on absorbance information detected when there is excess monomer. Then, the flow rate of the third solution A3 is controlled so that the tetracarboxylic dianhydride / diamine ratio approaches a value that makes the viscosity of the second polymerization solution E the set value.

[0175] Fifth Embodiment Next, a polyamic acid production system according to a fifth embodiment will be described with reference to Figures 13 to 15. The fifth embodiment is an example of a polyamic acid production system having a single treatment section (reaction section), and is an example of a system that can control the supply of a solution based on fluctuations in the flow rate of the solution, which is a raw material.

[0176] First, a polyamic acid production system 1D according to the fifth embodiment will be described with reference to Figures 13 and 14. However, a description of the same configuration as in the first embodiment will be omitted.

[0177] In the polyamic acid production system 1D, a first supply pump 15, a first flow control valve 151, and a first flow measurement unit 152 are arranged in this order from the upstream side to the downstream side between the first tank 11 and the first mixing unit 20.

[0178] The first supply pump 15 is configured as a positive displacement pump. Examples of the positive displacement pump include a reciprocating pump of a push type such as a plunger pump, and a rotary pump such as a gear pump equipped with gears.

[0179] It is preferable to select a pump with a small inherent pulsation rate (rate of flow rate fluctuation) as the first supply pump 15. Instead of selecting a pump with a small inherent pulsation rate (rate of flow rate fluctuation) as the first supply pump 15, or in addition to selecting a pump with a small inherent pulsation rate (rate of flow rate fluctuation) as the first supply pump 15, it is also preferable to provide a device for damping flow rate fluctuations (for example, an accumulator) in the liquid transfer line L. By providing a damping device such as an accumulator, the rate of flow rate fluctuation can be further reduced.

[0180] The first flow rate adjustment valve 151 is disposed between the first supply pump 15 and the first mixing unit 20. The first flow rate adjustment valve 151 is a valve capable of adjusting the flow rate of the first solution A1 supplied by the first supply pump 15. In the present embodiment, the flow rate of the first solution A1 is adjusted by adjusting the valve opening degree of the first flow rate adjustment valve 151. The valve opening degree of the first flow rate adjustment valve 151 is controlled by a first control unit 200D, which will be described later.

[0181] The first flow rate measuring unit 152 measures the flow rate of the first solution A1 in the first liquid delivery unit L1 downstream of the first supply pump 15. In this embodiment, the first flow rate measuring unit 152 is disposed between the first flow rate adjustment valve 151 and the first mixing unit 20. The first flow rate measuring unit 152 may also be disposed upstream of the first flow rate adjustment valve 151 and downstream of the first supply pump 15. The first flow rate measuring unit 152 outputs the measured flow rate of the first solution A1 to a first control unit 200D, which will be described later.

[0182] In the polyamic acid production system 1D, a second supply pump 16, a second flow control valve 161, and a second flow measurement unit 162 are disposed in this order from the upstream side to the downstream side between the second tank 12 and the first mixing unit 20 in the second liquid delivery unit L2.

[0183] The second supply pump 16 is configured as a positive displacement pump, similar to the first supply pump 15 described above.

[0184] It is preferable to select a pump with a small inherent pulsation rate (rate of flow rate fluctuation) as the second supply pump 16. Instead of selecting a pump with a small inherent pulsation rate (rate of flow rate fluctuation) as the second supply pump 16, or in addition to selecting a pump with a small inherent pulsation rate (rate of flow rate fluctuation) as the second supply pump 16, it is also preferable to provide a device for damping flow rate fluctuations (for example, an accumulator) in the liquid transfer line L. By providing a damping device such as an accumulator, the rate of flow rate fluctuation can be further reduced.

[0185] The second flow rate adjustment valve 161 is disposed between the second supply pump 16 and the first mixing unit 20. The second flow rate adjustment valve 161 is a valve capable of adjusting the flow rate of the second solution A2 supplied by the second supply pump 16. In this embodiment, the flow rate of the second solution A2 is adjusted by adjusting the valve opening degree of the second flow rate adjustment valve 161. The valve opening degree of the second flow rate adjustment valve 161 is controlled by a first control unit 200D, which will be described later.

[0186] The second flow rate measuring unit 162 measures the flow rate of the second solution A2 in the second liquid delivery unit L2 downstream of the second supply pump 16. In this embodiment, the second flow rate measuring unit 162 is disposed between the second flow rate adjustment valve 161 and the first mixing unit 20. The second flow rate measuring unit 162 may also be disposed upstream of the second flow rate adjustment valve 161 and downstream of the second supply pump 16. The second flow rate measuring unit 162 outputs the measured flow rate of the second solution A2 to the first control unit 200D, which will be described later.

[0187] The first control unit 200D will be described. The first supply pump 15, the second supply pump 16, the first flow rate adjustment valve 151, the first flow rate measurement unit 152, the second flow rate adjustment valve 161, and the second flow rate measurement unit 162 are electrically connected to the first control unit 200D.

[0188] The first control unit 200D controls the flow rate fluctuations of the first solution A1 and / or the second solution A2 so that the peak values ​​of the flow rate values ​​of the first solution A1 and the second solution A2 fluctuate in synchronization (i.e., so that the flow rate fluctuations of the first solution A1 and the flow rate fluctuations of the second solution A2 are synchronized).

[0189] Here, "the peak values ​​of the flow rate values ​​fluctuate synchronously" means that the periods of the flow rate fluctuations are substantially the same, and a slight difference in phase is acceptable. For example, when the distance between adjacent peaks (crests) of the flow rate value of the first solution A1 is L1 and the distance between adjacent peaks (crests) of the flow rate value of the first solution A1 and the flow rate value of the second solution A2 (i.e., the phase shift) is M1, it is preferable that L1 and M1 satisfy the following formula (1): 0≦(M1 / L1)≦0.1 (1)

[0190] For example, in the flow rate waveform before control in Fig. 14, the flow fluctuations of the first solution A1 and the second solution A2 are not synchronized. In this case, the first control unit 200D controls the flow rate fluctuations of the first solution A1 and / or the second solution A2 so that the flow fluctuations of the first solution A1 and the second solution A2 are synchronized.

[0191] As a method for controlling the flow rate fluctuation of the first solution A1 and the flow rate fluctuation of the second solution A2 so as to synchronize them, for example, the following method can be mentioned. Plunger pumps are used as the first supply pump 15 and the second supply pump 16, and Coriolis mass flowmeters are used as the first flow rate measuring unit 152 and the second flow rate measuring unit 162. The first control unit 200D instructs the first supply pump 15 and / or the second supply pump 16 to set new strokes and rotation speeds based on the obtained flow rate information so that the flow rate fluctuations of the first solution A1 and the second solution A2 are synchronized. In this way, the flow rate fluctuations of the first solution A1 and the second solution A2 can be controlled to be synchronized.

[0192] 14 illustrates a case where the period of the flow rate fluctuation of the first solution A1 is constant, but the period of the flow rate fluctuation of the first solution A1 does not necessarily have to be constant. In other words, the distance between adjacent peaks (mountains) of the flow rate value of the first solution A1 does not necessarily have to be constant. Similarly, FIG. 14 illustrates a case where the period of the flow rate fluctuation of the second solution A2 is constant, but the period of the flow rate fluctuation of the second solution A2 does not necessarily have to be constant. In other words, the distance between adjacent peaks (mountains) of the flow rate value of the second solution A2 does not necessarily have to be constant.

[0193] Furthermore, the first control unit 200D controls the first flow rate fluctuation rate and / or the second flow rate fluctuation rate so as to reduce the difference between the flow rate fluctuation rate of the first solution A1 (hereinafter also referred to as the "first flow rate fluctuation rate") and the flow rate fluctuation rate of the second solution A2 (hereinafter also referred to as the "second flow rate fluctuation rate"). In this embodiment, the difference between the first flow rate fluctuation rate and the second flow rate fluctuation rate is preferably, for example, 3% or less, and more preferably 1% or less. The lower limit of the difference between the first flow rate fluctuation rate and the second flow rate fluctuation rate may be 0%, but is preferably 0.001% or more. By setting the difference between the first flow rate fluctuation rate and the second flow rate fluctuation rate to 0.001% or more and slightly varying the mixing ratio of the first solution A1 and the second solution A2, the first solution A1 and the second solution A2 tend to be mixed well.

[0194] In this embodiment, for example, as shown in the flow rate waveform before control in Figure 14, the first flow rate fluctuation rate Ha is defined as the ratio of the flow rate Sa, which is half the amplitude of the flow rate fluctuation, to the flow rate value Ka, which is the center of the amplitude of the flow rate fluctuation (Ha = (Sa / Ka) x 100 [%]). Also, for example, the second flow rate fluctuation rate Hb is defined as the ratio of the flow rate Sb, which is half the amplitude of the flow rate fluctuation, to the flow rate value Kb, which is the center of the amplitude of the flow rate fluctuation (Hb = (Sb / Kb) x 100 [%]). Furthermore, the absolute value of the difference between the first flow rate fluctuation rate Ha and the second flow rate fluctuation rate Hb is used as the difference x between the first flow rate fluctuation rate Ha and the second flow rate fluctuation rate Hb (x=|Ha−Hb|). In the flow rate waveform before control in FIG. 14, the first flow rate fluctuation rate Ha is greater than the second flow rate fluctuation rate Hb of the second solution A2 (Ha>Hb).

[0195] When the difference between the first flow rate fluctuation rate Ha and the second flow rate fluctuation rate Hb is outside a predetermined range, the first control unit 200D adjusts the flow rate using the first flow rate adjustment valve 151 and / or the second flow rate adjustment valve 161, and adjusts the supply pressure of the solution supplied by the first supply pump 15 and / or the second supply pump 16, so that the difference between the first flow rate fluctuation rate Ha and the second flow rate fluctuation rate Hb becomes smaller. In this embodiment, the predetermined range for the difference between the first flow rate fluctuation rate Ha and the second flow rate fluctuation rate Hb is set to, for example, 3% or less.

[0196] When controlling to reduce the difference between the first flow rate fluctuation rate Ha and the second flow rate fluctuation rate Hb, the first control unit 200D may control to reduce or increase the first flow rate fluctuation rate Ha, and may control to reduce or increase the second flow rate fluctuation rate Hb.

[0197] This is because, when the peak values ​​of the flow rate values ​​of the first solution A1 and the second solution A2 fluctuate synchronously, if the difference between the first flow rate fluctuation rate Ha and the second flow rate fluctuation rate Hb is small, the peaks and valleys of the flow rate fluctuations of the first solution A1 and the second solution A2 will overlap, regardless of the magnitude of the first flow rate fluctuation rate Ha and the second flow rate fluctuation rate Hb. In other words, when the first solution A1 and the second solution A2 are mixed, the peaks of the flow rate values ​​will mix, and the valleys of the flow rate values ​​will mix. Therefore, by executing control to reduce the difference between the first flow rate fluctuation rate Ha and the second flow rate fluctuation rate Hb, the mixing ratio of the first solution A1 and the second solution A2 can be made closer to the same ratio, regardless of the magnitude of the first flow rate fluctuation rate Ha and the second flow rate fluctuation rate Hb.

[0198] 14, when the first control unit 200 reduces the difference between the first flow rate fluctuation rate Ha and the second flow rate fluctuation rate Hb, the first control unit 200 controls the first flow rate fluctuation rate Ha to be reduced to match the second flow rate fluctuation rate Hb, which has a smaller flow rate fluctuation rate before control. By reducing the first flow rate fluctuation rate Ha to match the second flow rate fluctuation rate Hb, which has a smaller flow rate fluctuation rate, even if the first solution A1 and the second solution A2 become out of synchronization for some reason, it is possible to minimize fluctuations in the mixing ratio of the first solution A1 and the second solution A2 and stabilize the mixing ratio of the first solution A1 and the second solution A2.

[0199] 14, the first flow rate fluctuation rate Ha is greater than the second flow rate fluctuation rate Hb (Ha>Hb). Therefore, the first control unit 200D reduces the valve opening of the first flow rate adjustment valve 151 so that the first flow rate fluctuation rate Ha becomes smaller. Furthermore, the first control unit 200D increases the supply pressure (discharge pressure) of the first supply pump 15 so that the supply rate of the first supply pump 15 becomes the same as the supply rate before the valve opening of the first flow rate adjustment valve 151 was reduced. As a result, the difference x (=|Ha-Hb|) between the first flow rate fluctuation rate Ha and the second flow rate fluctuation rate Hb becomes smaller.

[0200] The first control unit 200 is not limited to controlling the first flow rate fluctuation rate Ha to be smaller in accordance with the second flow rate fluctuation rate Hb having a smaller flow rate fluctuation rate, but may also control the second flow rate fluctuation rate Hb to be larger in accordance with the first flow rate fluctuation rate Ha having a larger flow rate fluctuation rate.

[0201] Next, the operation of the polyamic acid production system 1D according to the fifth embodiment will be described with reference to FIG. First, in the polyamic acid production system 1D, by starting operation, the first supply pump 15 supplies the first solution A1, and the second supply pump 16 supplies the second solution A2. Here, the supply pressures (discharge pressures) of the first supply pump 15 and the second supply pump 16 are controlled by the first control unit 200D so that the first solution A1 and the second solution A2 are supplied at a desired ratio.

[0202] 15, in step ST71, the first flow rate measurement unit 152 measures and obtains the flow rate of the first solution A1. The second flow rate measurement unit 162 measures and obtains the flow rate of the second solution A2. In this embodiment, the first control unit 200D controls the flow rates of the first solution A1 and the second solution A2 so that the flow rate fluctuations are synchronized.

[0203] Next, in step ST72, the first control unit 200D determines whether the difference between the first flow rate fluctuation rate and the second flow rate fluctuation rate is outside a predetermined range. In this embodiment, the predetermined range for the difference between the first flow rate fluctuation rate and the second flow rate fluctuation rate is set to, for example, 3% or less. This is because, when the difference between the first flow rate fluctuation rate and the second flow rate fluctuation rate is, for example, 3% or less, it is possible to stably obtain the desired polyamic acid.

[0204] If the first control unit 200D determines that the difference between the first flow rate fluctuation rate and the second flow rate fluctuation rate is outside the predetermined range (YES), the process proceeds to step ST73. If the first control unit 200D determines that the difference between the first flow rate fluctuation rate and the second flow rate fluctuation rate is not outside the predetermined range (NO), the process returns to step ST71.

[0205] Next, in step ST73, the first control unit 200D controls the difference between the first flow rate fluctuation rate and the second flow rate fluctuation rate so that it falls within a predetermined range. For example, in the flow rate waveform before control in FIG. 14, the first flow rate fluctuation rate Ha is greater than the second flow rate fluctuation rate Hb (Ha>Hb). Therefore, the first control unit 200D reduces the valve aperture of the first flow rate adjustment valve 151 so that the first flow rate fluctuation rate Ha decreases. In addition, the first control unit 200D increases the supply pressure (discharge pressure) of the first supply pump 15 so that the supply rate of the first supply pump 15 becomes the same as the supply rate before the valve aperture of the first flow rate adjustment valve 151 was reduced. As a result, the difference x (=|Ha-Hb|) between the first flow rate fluctuation rate Ha and the second flow rate fluctuation rate Hb falls within a predetermined range.

[0206] Here, the first solution A1 and the second solution A2 have their peak values ​​of flow rate values ​​fluctuating synchronously, and therefore the first solution A1 and the second solution A2 are mixed in a state where the peaks and valleys of the flow rate fluctuations coincide. Therefore, by controlling the difference between the first flow rate fluctuation rate and the second flow rate fluctuation rate to be within a predetermined range, the first solution A1 and the second solution A2 can be mixed in approximately the same ratio, and the desired polyamic acid can be stably obtained.

[0207] Next, the first control unit 200D goes into a standby state (step ST74), after which the process returns to step ST71.

[0208] The polyamic acid production system 1D of this embodiment has the following advantages in addition to the advantages of the first embodiment described above. The polyamic acid production system 1D includes a first control unit 200D that controls the supply of the first solution A1 and / or the second solution A2 so that the flow rate fluctuations of the first solution A1 and the second solution A2 are synchronized and the difference between the first flow rate fluctuation rate and the second flow rate fluctuation rate is small. Such a polyamic acid production system 1D can synchronize the flow rate fluctuations of the first solution A1 and the second solution A2 and reduce the difference between the first flow rate fluctuation rate and the second flow rate fluctuation rate, making it possible to more stably obtain a desired polyamic acid.

[0209] Sixth Embodiment Next, a polyamic acid production system according to a sixth embodiment will be described with reference to Figures 16 and 17. The sixth embodiment is an example of a polyamic acid production system having two treatment sections (reaction sections), and is an example of a system that can control the supply of a solution based on fluctuations in the flow rate of the solution, which is a raw material.

[0210] First, a polyamic acid production system 1E according to the sixth embodiment will be described with reference to FIG. As shown in FIG. 16, the polyamic acid production system 1E includes a first processing unit K5 and a second processing unit K6.

[0211] The first processing unit K5 has the same configuration as that of the polyamic acid production system 1D in the fifth embodiment, and therefore a detailed description thereof will be omitted in this embodiment. Also, a detailed description of the second processing unit K6 having the same configuration as that in the second embodiment will be omitted in this embodiment.

[0212] In the polyamic acid production system 1E, a third supply pump 17, a third flow control valve 171, and a third flow measurement unit 172 are disposed between the third tank 13 and the second mixing unit 50 in this order from the upstream side to the downstream side.

[0213] The third supply pump 17 is configured as a positive displacement pump, similar to the first supply pump 15 described above.

[0214] It is preferable to select a pump with a small inherent pulsation rate (rate of flow rate fluctuation) as the third supply pump 17. Instead of selecting a pump with a small inherent pulsation rate (rate of flow rate fluctuation) as the third supply pump 17, or in addition to selecting a pump with a small inherent pulsation rate (rate of flow rate fluctuation) as the third supply pump 17, it is also preferable to provide a device for damping flow rate fluctuations (for example, an accumulator) in the liquid transfer line L. By providing a damping device such as an accumulator, the rate of flow rate fluctuation can be further reduced.

[0215] The third flow rate adjustment valve 171 is disposed between the third supply pump 17 and the second mixing unit 50. The third flow rate adjustment valve 171 is a valve capable of adjusting the flow rate of the third solution A3 supplied by the third supply pump 17. In this embodiment, the flow rate of the third solution A3 is adjusted by adjusting the valve opening degree of the third flow rate adjustment valve 171. The valve opening degree of the third flow rate adjustment valve 171 is controlled by a second control unit 200E, which will be described later.

[0216] The third flow rate measuring unit 172 measures the flow rate of the third solution A3 in the fourth liquid delivery unit L4 downstream of the third supply pump 17. In this embodiment, the third flow rate measuring unit 172 is disposed between the third flow rate adjustment valve 171 and the second mixing unit 50. The third flow rate measuring unit 172 may also be disposed upstream of the third flow rate adjustment valve 171 and downstream of the third supply pump 17. The third flow rate measuring unit 172 outputs the measured flow rate of the third solution A3 to the second control unit 200E, which will be described later.

[0217] In addition, in the polyamic acid production system 1E, a fourth flow rate measuring unit 182 is disposed between the first reaction unit 30 and the second mixing unit 50.

[0218] The fourth flow rate measuring unit 182 measures the flow rate of the first polymerization solution C at the third liquid supply unit L3 downstream of the first reaction unit 30. The fourth flow rate measuring unit 182 outputs the measured flow rate of the first polymerization solution C to the second control unit 200E, which will be described later.

[0219] The second control unit 200E is now described. The first supply pump 15, the second supply pump 16, the first flow rate adjustment valve 151, the first flow rate measurement unit 152, the second flow rate adjustment valve 161, the second flow rate measurement unit 162, the third flow rate adjustment valve 171, the third flow rate measurement unit 172, and the fourth flow rate measurement unit 182 are electrically connected to the second control unit 200E.

[0220] The second control unit 200E also has the functions of the first control unit 200D in the fifth embodiment, but detailed description of the parts common to the first control unit 200D will be omitted below.

[0221] The second control unit 200E controls the flow rate fluctuations of the first polymeric solution C and / or the third solution A3 so that the peak values ​​of the flow rate values ​​of the first polymeric solution C and the third solution A3 fluctuate in synchronization (i.e., so that the flow rate fluctuations of the first polymeric solution C and the flow rate fluctuations of the third solution A3 are synchronized).

[0222] Here, "the peak values ​​of the flow rate values ​​fluctuate synchronously" means that the periods of the flow rate fluctuations are substantially the same, and a slight difference in phase is permissible. For example, when the distance between adjacent peaks (crests) of the flow rate value of the first polymerization solution C is L2 and the distance between adjacent peaks (crests) of the flow rate value of the first polymerization solution C and the flow rate value of the third solution A3 (i.e., the phase shift) is M2, it is preferable that L2 and M2 satisfy the following formula (2): 0≦(M2 / L2)≦0.1 (2)

[0223] As a method for controlling the flow rate fluctuation of the first polymerization solution C and the flow rate fluctuation of the third solution A3 so as to synchronize with each other, for example, the following method can be mentioned. Plunger pumps are used as the first supply pump 15, the second supply pump 16, and the third supply pump 17, and Coriolis mass flowmeters are used as the third flow rate measurement unit 172 and the fourth flow rate measurement unit 182. The second control unit 200E instructs the third supply pump 17 to set a new stroke and rotation speed based on the obtained flow rate information so that the flow rate fluctuations of the first polymerizable solution C and the third solution A3 are synchronized. In this way, the flow rate fluctuations of the first polymerizable solution C and the third solution A3 can be controlled to be synchronized.

[0224] As in the fifth embodiment, the period of the flow rate fluctuation of the first polymerization solution C and the period of the flow rate fluctuation of the third solution A3 do not necessarily have to be constant.

[0225] Furthermore, the second control unit 200E controls the third flow rate fluctuation rate so as to reduce the difference between the flow rate fluctuation rate of the first polymerizable solution C (hereinafter also referred to as the "polymerizable solution flow rate fluctuation rate") and the flow rate fluctuation rate of the third solution A3 (hereinafter also referred to as the "third flow rate fluctuation rate"). In this embodiment, the difference between the flow rate fluctuation rate of the polymerizable solution and the third flow rate fluctuation rate is, for example, preferably 3% or less, and more preferably 1% or less. The lower limit of the difference between the flow rate fluctuation rate of the polymerizable solution and the third flow rate fluctuation rate may be 0%, but is preferably 0.001% or more. By setting the difference between the flow rate fluctuation rate of the polymerizable solution and the third flow rate fluctuation rate to 0.001% or more and slightly varying the mixing ratio of the first polymerizable solution C and the third solution A3, the first polymerizable solution C and the third solution A3 tend to be mixed well.

[0226] In this embodiment, based on the same concept as the first flow rate fluctuation rate Ha and the second flow rate fluctuation rate Hb in the fifth embodiment, for example, the polymerization solution flow rate fluctuation rate Hc is defined as the ratio of the flow rate Sc, which is half the amplitude of the flow rate fluctuation, to the flow rate value Kc at the center of the amplitude of the flow rate fluctuation (Hc=(Sc / Kc)×100[%]). Also, for example, the third flow rate fluctuation rate Hd is defined as the ratio of the flow rate Sd, which is half the amplitude of the flow rate fluctuation, to the flow rate value Kd at the center of the amplitude of the flow rate fluctuation (Hd=(Sd / Kd)×100[%]). Furthermore, the difference y between the polymerization solution flow rate fluctuation rate Hc and the third flow rate fluctuation rate Hd is the absolute value of the difference between the polymerization solution flow rate fluctuation rate Hc and the third flow rate fluctuation rate Hd (y = |Hc - Hd|), based on the same concept as the difference x between the first flow rate fluctuation rate Ha and the second flow rate fluctuation rate Hb in the fifth embodiment.

[0227] When the difference between the polymerization solution flow rate fluctuation rate Hc and the third flow rate fluctuation rate Hd is outside a predetermined range, the second control unit 200E adjusts the flow rate of the third solution A3 using the third flow rate adjustment valve 171 and adjusts the supply pressure of the solution supplied by the third supply pump 17 so as to reduce the difference between the polymerization solution flow rate fluctuation rate Hc and the third flow rate fluctuation rate Hd. In this embodiment, the predetermined range for the difference between the polymerization solution flow rate fluctuation rate Hc and the third flow rate fluctuation rate Hd is set to, for example, 3% or less.

[0228] When the second control unit 200E controls the difference between the polymerization solution flow rate fluctuation rate Hc and the third flow rate fluctuation rate Hd to be small, it may control the third flow rate fluctuation rate Hd to be small or large.

[0229] This is because, when the peak values ​​of the flow rate values ​​of the polymerization solution flow rate fluctuation rate Hc and the third flow rate fluctuation rate Hd fluctuate synchronously, if the difference between the polymerization solution flow rate fluctuation rate Hc and the third flow rate fluctuation rate Hd is small, the peaks and valleys of the flow rate values ​​overlap in the peaks and valleys of the flow rate fluctuations of the first polymerization solution C and the third solution A3, regardless of the magnitude of the polymerization solution flow rate fluctuation rate Hc and the third flow rate fluctuation rate Hd. That is, when the first polymerization solution C and the third solution A3 are mixed, the peaks of the flow rate values ​​mix together and the valleys of the flow rate values ​​mix together. Therefore, by executing control to reduce the difference between the polymerization solution flow rate fluctuation rate Hc and the third flow rate fluctuation rate Hd, the mixing ratio of the first polymerization solution C and the third solution A3 can be made closer to the same ratio, regardless of the magnitude of the polymerization solution flow rate fluctuation rate Hc and the third flow rate fluctuation rate Hd.

[0230] Next, the operation of the polyamic acid production system 1E according to the sixth embodiment will be described with reference to FIG. First, when the polyamic acid production system 1E starts operating, the first supply pump 15 supplies the first solution A1, the second supply pump 16 supplies the second solution A2, and the third supply pump 17 supplies the third solution A3. Here, the supply pressures (discharge pressures) of the first supply pump 15 and the second supply pump 16 are controlled by the second control unit 200E so that the first solution A1 and the second solution A2 are supplied at a desired ratio. The supply pressure (discharge pressure) of the third supply pump 17 is controlled by the second control unit 200E so that the third solution A3 is supplied at a desired ratio.

[0231] 17, in step ST81, the fourth flow rate measurement unit 182 measures and obtains the flow rate of the first polymerization solution C. Furthermore, the third flow rate measurement unit 172 measures and obtains the flow rate of the third solution A3. In this embodiment, the second control unit 200E controls the flow rates of the first polymerization solution C and the third solution A3 so that the flow rate fluctuations are synchronized.

[0232] Next, in step ST82, the second control unit 200E determines whether the difference between the polymerization solution flow rate fluctuation rate and the third flow rate fluctuation rate is outside a predetermined range. In this embodiment, the predetermined range for the difference between the polymerization solution flow rate fluctuation rate and the third flow rate fluctuation rate is set to, for example, 3% or less. This is because, when the difference between the polymerization solution flow rate fluctuation rate and the third flow rate fluctuation rate is, for example, 3% or less, it is possible to stably obtain the desired polyamic acid.

[0233] If the second control unit 200E determines that the difference between the polymerization solution flow rate fluctuation rate and the third flow rate fluctuation rate is outside the predetermined range (YES), the process proceeds to step ST83. If the second control unit 200E determines that the difference between the polymerization solution flow rate fluctuation rate and the third flow rate fluctuation rate is not outside the predetermined range (NO), the process returns to step ST81.

[0234] Next, in step ST83, the second control unit 200E controls the difference between the polymerization solution flow rate fluctuation rate and the third flow rate fluctuation rate so that it falls within a predetermined range. For example, the second control unit 200E adjusts the valve opening of the third flow rate adjustment valve 171 to decrease or increase, and decreases or increases the supply pressure (discharge pressure) of the third supply pump 17 so that the supply rate of the third solution A3 becomes the same as the supply rate before the valve opening of the third flow rate adjustment valve 171 was decreased or increased. As a result, after the control, the third flow rate fluctuation rate is adjusted to decrease or increase, and the difference y between the polymerization solution flow rate fluctuation rate and the third flow rate fluctuation rate falls within a predetermined range.

[0235] Here, the first polymerization solution C and the third solution A3 fluctuate in sync with each other in peak flow rate, so that the first polymerization solution C and the third solution A3 are mixed in a state where the peaks and valleys of the flow rate fluctuations coincide. Therefore, by controlling the difference between the polymerization solution flow rate fluctuation rate and the third flow rate fluctuation rate to be within a predetermined range, the first polymerization solution C and the third solution A3 can be mixed in approximately the same ratio, and the desired polyamic acid can be stably obtained.

[0236] Next, the second control section 200E goes into a standby state (step ST84), after which the process returns to step ST81.

[0237] The polyamic acid production system 1E of this embodiment has the following advantages in addition to the advantages of the second embodiment described above. The polyamic acid production system 1E includes a second control unit 200E that controls the supply of the third solution A3 so that the flow rate fluctuations of the first polymerization solution C and the third solution A3 are synchronized and the difference between the rate of change of the polymerization solution flow rate and the rate of change of the third flow rate is reduced. Such a polyamic acid production system 1E can synchronize the flow rate fluctuations of the first polymerization solution C and the third solution A3 and reduce the difference between the rate of change of the polymerization solution flow rate and the rate of change of the third flow rate, making it possible to more stably obtain a desired polyamic acid.

[0238] Seventh Embodiment Next, a polyamic acid production system according to the seventh embodiment will be described with reference to Figures 18 to 20. The seventh embodiment is an example of a polyamic acid production system having a single treatment section (reaction section), and is an example of a system capable of controlling the supply of a solution based on the flow rate fluctuation rate of the solution, which is a raw material.

[0239] First, a polyamic acid production system 1F according to the seventh embodiment will be described with reference to Figures 18 and 19. However, since the polyamic acid production system 1F is similar to the above-described fifth embodiment except for the first control unit 200F, a description of the configuration other than the first control unit 200F will be omitted.

[0240] In this embodiment, as in the first embodiment, the first polymerizable compound contained in the first solution A1 is a tetracarboxylic dianhydride, and the second polymerizable compound contained in the second solution A2 is a diamine.

[0241] The first control unit 200F controls the molar ratio of the tetracarboxylic dianhydride contained in the first solution A1 to the diamine contained in the second solution A2 to be within a predetermined range by controlling the first supply pump 15 and / or the second supply pump 16. The molar ratio is set, for example, so as to obtain a polyamic acid with desired properties.

[0242] In this embodiment, for example, when the number of moles of diamine at an equivalent ratio to the number of moles of tetracarboxylic dianhydride is taken as 100, the number of moles of diamine is preferably within a range of 95 to 105, and more preferably within a range of 97.5 to 102.5.

[0243] In this embodiment, when the molar ratio of tetracarboxylic dianhydride to diamine is an equivalent ratio, the molecular weight of the polyamic acid is maximized, and the viscosity of the first polymerization solution C is also maximized. Furthermore, as the molar ratio of tetracarboxylic dianhydride to diamine deviates from the equivalent ratio, the molecular weight of the polyamic acid significantly decreases, and the viscosity of the first polymerization solution C also significantly decreases. Therefore, when the molar ratio of tetracarboxylic dianhydride to diamine fluctuates due to inherent pulsation of the first supply pump 15 and the second supply pump 16, the molecular weight of the polyamic acid significantly changes, and the viscosity of the first polymerization solution C also significantly changes. Thus, when the viscosity of the first polymerization solution C varies, flow rate fluctuations (pulsations) occur in the first polymerization solution C, and accordingly, flow rate fluctuations (pulsations) also occur in the first solution A1 and the second solution A2. The effect of these flow rate fluctuations (pulsations) becomes more pronounced as the viscosity increases.

[0244] At this time, if the back pressure applied to the solution flowing through the liquid feed line L is sufficiently high, the flow rate fluctuation (pulsation) of the first polymerization solution C caused by viscosity variations will be small, and the resulting flow rate fluctuation (pulsation) of the first solution A1 and the second solution A2 will also be small. However, the flow rate fluctuation (pulsation) of the first solution A1 and the second solution A2 will be superimposed on the pulsation inherent to the first supply pump 15 and the second supply pump 16, resulting in complex fluctuations in the flow rates of the first solution A1 and the second solution A2. In this embodiment, various controls are performed by the first control unit 200F to continuously and stably obtain the desired polyamic acid even under such circumstances.

[0245] The first control unit 200F is electrically connected to the first supply pump 15, the second supply pump 16, the first flow rate adjustment valve 151, the first flow rate measurement unit 152, the second flow rate adjustment valve 161, and the second flow rate measurement unit 162.

[0246] The first control unit 200F controls the flow rate fluctuation rate of the first solution A1 (first flow rate fluctuation rate) to be equal to or less than a first threshold, and controls the flow rate fluctuation rate of the second solution A2 (second flow rate fluctuation rate) to be equal to or less than a second threshold. In this embodiment, the first flow rate fluctuation rate and / or the second flow rate fluctuation rate are preferably, for example, 3% or less, and more preferably 2.5% or less. The lower limit of the first flow rate fluctuation rate and / or the second flow rate fluctuation rate is not particularly limited, but may be, for example, 0.01%.

[0247] 19 , when the first flow rate fluctuation rate Ha is greater than the first threshold value TH1, the first control unit 200F adjusts the valve aperture of the first flow rate adjustment valve 151 to decrease so that the first flow rate fluctuation rate Ha becomes equal to or less than the first threshold value TH1, and increases the supply pressure of the solution supplied by the first supply pump 15 so that the supply rate of the first solution A1 becomes the same as the supply rate before adjusting the valve aperture of the first flow rate adjustment valve 151. Furthermore, when the second flow rate fluctuation rate Hb is greater than the second threshold value TH2, the first control unit 200F adjusts the valve aperture of the second flow rate adjustment valve 161 to decrease so that the second flow rate fluctuation rate Hb becomes equal to or less than the second threshold value TH2, and increases the supply pressure of the solution supplied by the second supply pump 16 so that the supply rate of the second solution A2 becomes the same as the supply rate before adjusting the valve aperture of the second flow rate adjustment valve 161. As a result, the first flow rate fluctuation rate Ha is adjusted to be equal to or less than the first threshold value TH1 (Ha≦TH1), and the second flow rate fluctuation rate Hb is adjusted to be equal to or less than the second threshold value TH2 (Hb≦TH2), as shown in the flow rate waveform after control in Fig. 19. In this embodiment, the first threshold value TH1 for the first flow rate fluctuation rate Ha and the second threshold value TH2 for the second flow rate fluctuation rate Hb are preferably, for example, 3%, and more preferably 2.5%.

[0248] In this way, by adjusting the supply pressure of the solution supplied by the first supply pump 15 and / or the second supply pump 16 in accordance with the adjustment of the valve opening of the first flow control valve 151 and / or the second flow control valve 161, the first solution A1 and the second solution A2 can be mixed without changing the ratio of the tetracarboxylic dianhydride contained in the first solution A1 to the diamine contained in the second solution A2.

[0249] Next, the operation of the polyamic acid production system 1F in the seventh embodiment will be described with reference to FIG. First, in the polyamic acid production system 1F, by starting operation, the first supply pump 15 supplies the first solution A1, and the second supply pump 16 supplies the second solution A2. Here, the first control unit 200F controls the supply pressures (discharge pressures) of the first supply pump 15 and the second supply pump 16 so that the first solution A1 and the second solution A2 are supplied at a desired ratio.

[0250] 20, in step ST91, the first flow rate measurement unit 152 measures and obtains the flow rate of the first solution A1, and the second flow rate measurement unit 162 measures and obtains the flow rate of the second solution A2.

[0251] Next, in step ST92, the first control unit 200F determines whether the first flow rate fluctuation rate is greater than a first threshold value and whether the second flow rate fluctuation rate is greater than a second threshold value. In this embodiment, the first threshold value and the second threshold value are set to, for example, 3%. This is because a desired polyamic acid can be stably obtained when the first flow rate fluctuation rate and the second flow rate fluctuation rate are 3% or less.

[0252] If the first control unit 200F determines that the first flow rate fluctuation rate is greater than the first threshold value or the second flow rate fluctuation rate is greater than the second threshold value (YES), the process proceeds to step ST93. If the first control unit 200F determines that the first flow rate fluctuation rate is equal to or less than the first threshold value and the second flow rate fluctuation rate is equal to or less than the second threshold value (NO), the process returns to step ST91.

[0253] Next, in step ST93, the first control unit 200F controls the first flow rate fluctuation rate and / or the second flow rate fluctuation rate. If the first flow rate fluctuation rate is greater than the first threshold, the first control unit 200F adjusts the valve aperture of the first flow rate adjustment valve 151 to be smaller so that the first flow rate fluctuation rate is equal to or less than the first threshold, and increases the supply pressure of the solution supplied by the first supply pump 15 so that the supply rate of the first solution A1 is the same as the supply rate before adjusting the valve aperture of the first flow rate adjustment valve 151. If the second flow rate fluctuation rate is greater than the second threshold, the first control unit 200F adjusts the valve aperture of the second flow rate adjustment valve 161 to be smaller so that the second flow rate fluctuation rate is equal to or less than the second threshold, and increases the supply pressure of the solution supplied by the second supply pump 16 so that the supply rate of the second solution A2 is the same as the supply rate before adjusting the valve aperture of the second flow rate adjustment valve 161. As a result, as shown in FIG. 19, the first flow rate fluctuation rate Ha after control becomes equal to or less than the first threshold value TH1 (Ha≦TH1), and the second flow rate fluctuation rate Hb after control becomes equal to or less than the second threshold value TH2 (Hb≦TH2).

[0254] Next, the first control unit 200F goes into a standby state (step ST94), after which the process returns to step ST91.

[0255] The polyamic acid production system 1F of this embodiment has the following advantages in addition to the advantages of the first embodiment described above. The polyamic acid production system 1F includes a first control unit 200F that controls the first flow rate fluctuation rate to be equal to or less than a first threshold value and controls the second flow rate fluctuation rate to be equal to or less than a second threshold value. Such a polyamic acid production system 1F can reduce the first flow rate fluctuation rate and the second flow rate fluctuation rate, thereby making it possible to more stably obtain a desired polyamic acid.

[0256] Eighth Embodiment Next, a polyamic acid production system according to an eighth embodiment will be described with reference to Figures 21 and 22. The eighth embodiment is an example of a polyamic acid production system having two treatment sections (reaction sections), and is an example of a system that can control the supply of a solution based on the flow rate fluctuation rate of the solution, which is a raw material.

[0257] First, a polyamic acid production system 1G according to the eighth embodiment will be described with reference to Fig. 21. However, since the polyamic acid production system 1G is the same as that of the sixth embodiment except for the second control unit 200G, a description of the configuration other than the second control unit 200G will be omitted.

[0258] In this embodiment, as in the second embodiment, the polyamic acid contained in the first polymerization solution C is a polyamic acid having an acid anhydride group at its terminal, and the polymerizable compound contained in the third solution A3 is a diamine.

[0259] The second control unit 200G controls the third supply pump 17 to control the molar ratio of the acid anhydride-terminated polyamic acid contained in the first polymerization solution C to the diamine contained in the third solution A3 so that it falls within a predetermined range. The molar ratio is set, for example, so as to obtain a polyamic acid with desired properties.

[0260] In this embodiment, assuming that the number of moles of diamine at an equivalent ratio to the number of moles of acid anhydride group-terminated polyamic acid is 100, the number of moles of diamine is preferably within the range of 95 to 105, and more preferably within the range of 97.5 to 102.5.

[0261] In this embodiment, when the molar ratio of the acid anhydride-terminated polyamic acid to the diamine is an equivalent ratio, the molecular weight of the polyamic acid is maximized, and the viscosity of the second polymerization solution E is also maximized. Furthermore, as the molar ratio of the acid anhydride-terminated polyamic acid to the diamine deviates from the equivalent ratio, the molecular weight of the polyamic acid significantly decreases, and the viscosity of the second polymerization solution E also significantly decreases. Therefore, when the molar ratio of the acid anhydride-terminated polyamic acid to the diamine fluctuates due to the inherent pulsation of the third supply pump 17, the molecular weight of the polyamic acid significantly changes, and the viscosity of the second polymerization solution E also significantly changes. Thus, when the viscosity of the second polymerization solution E varies, flow rate fluctuations (pulsations) occur in the second polymerization solution E, and accordingly, flow rate fluctuations (pulsations) also occur in the third solution A3. The effect of these flow rate fluctuations (pulsations) becomes more pronounced as the viscosity increases.

[0262] At this time, if the back pressure applied to the solution flowing through the liquid supply line L is sufficiently high, the flow rate fluctuation (pulsation) of the second polymerization solution E caused by uneven viscosity will be small, and the resulting flow rate fluctuation (pulsation) of the third solution A3 will also be small. However, the flow rate fluctuation (pulsation) of the third solution A3 will be superimposed on the pulsation inherent to the third supply pump 17, resulting in complex fluctuations in the flow rate of the third solution A3. In this embodiment, various controls are performed by the second control unit 200G to continuously and stably obtain the desired polyamic acid even under such circumstances.

[0263] The second control unit 200G is electrically connected to the first supply pump 15, the second supply pump 16, the first flow control valve 151, the first flow measurement unit 152, the second flow control valve 161, the second flow measurement unit 162, the third flow control valve 171, the third flow measurement unit 172, and the fourth flow measurement unit 182.

[0264] The second control unit 200G also has the functions of the first control unit 200F in the seventh embodiment, but detailed description of the parts common to the first control unit 200F will be omitted below.

[0265] The second control unit 200G controls the flow rate fluctuation rate of the third solution A3 (third flow rate fluctuation rate) so that it is equal to or less than a third threshold. In this embodiment, the third flow rate fluctuation rate is, for example, preferably equal to or less than 3%, and more preferably equal to or less than 2.5%. The lower limit of the third flow rate fluctuation rate is not particularly limited, but may be, for example, 0.01%.

[0266] For example, when the third flow rate fluctuation rate is greater than the third threshold, the second control unit 200G adjusts the valve opening of the third flow rate adjustment valve 171 to be smaller in order to make the third flow rate fluctuation rate equal to or less than the third threshold, and also increases the supply pressure of the solution supplied by the third supply pump 17 so that the supply amount of the third solution A3 becomes the same as the supply amount before adjusting the valve opening of the third flow rate adjustment valve 171. In this embodiment, the third threshold for the third flow rate fluctuation rate is preferably, for example, 3%, and more preferably 2.5%.

[0267] In this way, by adjusting the supply pressure of the solution supplied by the third supply pump 17 in accordance with the adjustment of the valve opening of the third flow control valve 171, the first polymerization solution C and the third solution A3 can be mixed without changing the ratio of the acid anhydride group-terminated polyamic acid contained in the first polymerization solution C to the diamine contained in the third solution A3.

[0268] Next, the operation of the polyamic acid production system 1G according to the eighth embodiment will be described with reference to FIG. First, when the polyamic acid production system 1G starts operating, the first supply pump 15 supplies the first solution A1, the second supply pump 16 supplies the second solution A2, and the third supply pump 17 supplies the third solution A3. Here, the supply pressures (discharge pressures) of the first supply pump 15 and the second supply pump 16 are controlled by the second control unit 200G so that the first solution A1 and the second solution A2 are supplied at a desired ratio. The supply pressure (discharge pressure) of the third supply pump 17 is controlled by the second control unit 200G so that the third solution A3 is supplied at a desired ratio.

[0269] 22, in step ST101, the fourth flow rate measuring unit 182 measures and obtains the flow rate of the first polymerization solution C. In addition, the third flow rate measuring unit 172 measures and obtains the flow rate of the third solution A3.

[0270] Next, in step ST102, the second control unit 200G determines whether the third flow rate fluctuation rate is greater than a third threshold value. In this embodiment, the third threshold value is set to, for example, 3%. This is because a desired polyamic acid can be stably obtained when the third flow rate fluctuation rate is 3% or less.

[0271] If the second control unit 200G determines that the third flow rate fluctuation rate is greater than the third threshold value (YES), the process proceeds to step ST103. If the second control unit 200G determines that the third flow rate fluctuation rate is equal to or less than the third threshold value (NO), the process returns to step ST101.

[0272] Next, in step ST103, the second control unit 200G adjusts the valve aperture of the third flow rate adjustment valve 171 to be smaller in order to make the third flow rate fluctuation rate equal to or less than the third threshold, and also increases the supply pressure of the solution supplied by the third supply pump 17 so that the supply rate of the third solution A3 becomes the same as the supply rate before adjusting the valve aperture of the third flow rate adjustment valve 171. As a result, the third flow rate fluctuation rate after control becomes equal to or less than the third threshold.

[0273] Next, the second control unit 200G goes into a standby state (step ST104), after which the process returns to step ST101.

[0274] The polyamic acid production system 1G of this embodiment has the following advantages in addition to the advantages of the second embodiment described above. The polyamic acid production system 1G includes a second control unit 200G that controls the third flow rate fluctuation rate to be equal to or less than a third threshold value. According to such a polyamic acid production system 1G, the third flow rate fluctuation rate can be reduced, and therefore, the desired polyamic acid can be more stably obtained.

[0275] <Modification> The present invention is not limited to the above-described embodiment, and includes modifications and improvements within the scope of achieving the object of the present invention.

[0276] Although the above-described embodiments have been described separately as the first to eighth embodiments for convenience, the details described in each embodiment may be combined as appropriate. For example, in the fifth or seventh embodiment, similar to the third embodiment, the supply from the first supply pump 15 and / or the second supply pump 16 may be controlled based on the first reaction information acquired by the first measurement unit. Furthermore, in the fifth embodiment, similar to the seventh embodiment, the first flow rate fluctuation rate may be controlled to be equal to or less than a first threshold value, and the second flow rate fluctuation rate may be controlled to be equal to or less than a second threshold value.

[0277] Furthermore, in the above-described embodiment, the polyamic acid production system is configured to have one or two processing sections, but is not limited thereto and may be configured to have three or more processing sections. That is, the polyamic acid production system is not limited to one that performs a one-stage or two-stage reaction, but may be one that performs a three-stage or more reaction. For example, the polyamic acid production system may be configured to have three or more sets of mixing sections and reaction sections. The polyamic acid production system can adjust the supply amount, etc. in multiple stages so that the target reaction rate and quality are approached as the polyamic acid passes through each processing section.

[0278] In addition, in the polyamic acid production system, the first solution A1 and / or the second solution A2 may contain a filler. By adding the filler to the first solution A1 and / or the second solution A2, the filler can be easily introduced into the produced polyamic acid. [Example]

[0279] The present invention will be specifically explained below with reference to examples, but the present invention is not limited to these examples.

[0280] Example 1 In Example 1, polyamic acid was produced using a polyamic acid production system 1 having a structure as shown in Figure 1. A first tank 11 contained a first solution A1 prepared by dissolving an acid anhydride-terminated polyamic acid obtained by reacting 4,4'-diaminodiphenyl ether with pyromellitic dianhydride in N,N-dimethylformamide. A second tank 12 contained a second solution A2 prepared by dissolving p-phenylenediamine in N,N-dimethylformamide.

[0281] First, in the first mixing section 20, the first solution A1 supplied by the first supply pump 15 and the second solution A2 supplied by the second supply pump 16 were mixed to produce a first mixed solution B. Next, in the first reaction section 30, the first mixed solution B was stirred without contact with gas to produce a first polymerized solution C in which polyamic acid was dissolved. Specifically, the solution was stirred without contact with gas using a Kenics mixer-type static mixer (inner diameter 8 mm, length 335 mm) to allow the polymerization reaction to proceed. As a result, a first polymerized solution C with a higher viscosity than the first solution A1 was obtained. No air bubbles were observed in the obtained first polymerized solution C.

[0282] <Example 2> In Example 2, polyamic acid was produced using a polyamic acid production system 1 having a structure as shown in Figure 1. A first tank 11 contained a first solution A1 prepared by dissolving an acid anhydride-terminated polyamic acid obtained by reacting 4,4'-diaminodiphenyl ether with pyromellitic dianhydride in N,N-dimethylformamide. A second tank 12 contained a second solution A2 prepared by dissolving p-phenylenediamine in N,N-dimethylformamide.

[0283] First, in the first mixing section 20, the first solution A1 supplied by the first supply pump 15 and the second solution A2 supplied by the second supply pump 16 were mixed to produce a first mixed solution B. Next, in the first reaction section 30, the first mixed solution B was stirred without contact with gas to produce a first polymerization solution C in which polyamic acid was dissolved. Specifically, the solution was stirred without contact with gas using a drive-type mixer (FQ mixer, FQ40, manufactured by Sakura Seisakusho), and then further stirred without contact with gas using a Kenics mixer-type static mixer (inner diameter 8 mm, length 335 mm) to promote the polymerization reaction. The rotation speed of the drive-type mixer was set to 350 rpm. As a result, a first polymerization solution C with a higher viscosity than the first solution A1 was obtained. No air bubbles were observed in the resulting first polymerization solution C.

[0284] Example 3 In Example 3, polyamic acid was produced using a polyamic acid production system 1 having a structure as shown in Figure 1. A first tank 11 contained a first solution A1 prepared by dissolving an acid anhydride-terminated polyamic acid obtained by reacting 4,4'-diaminodiphenyl ether with pyromellitic dianhydride in N,N-dimethylformamide. A second tank 12 contained a second solution A2 prepared by dissolving p-phenylenediamine in N,N-dimethylformamide.

[0285] First, in the first mixing section 20, the first solution A1 supplied by the first supply pump 15 and the second solution A2 supplied by the second supply pump 16 were mixed to produce a first mixed solution B. Next, in the first reaction section 30, the first mixed solution B was stirred without contact with gas to produce a first polymerized solution C in which polyamic acid was dissolved. Specifically, the solution was stirred without contact with gas using a Kenics mixer-type static mixer (inner diameter 8 mm, length 335 mm), and then the solution was further stirred without contact with gas using a Kenics mixer-type static mixer (inner diameter 8 mm, length 260 mm) to allow the polymerization reaction to proceed. As a result, a first polymerized solution C with a higher viscosity than the first solution A1 was obtained. No air bubbles were observed in the resulting first polymerized solution C.

[0286] Example 4 A first polymerization solution C containing dissolved polyamic acid was prepared in the same manner as in Example 3, except that a solution of 2,2-bis(4-hydroxyphenyl)propanedibenzoate-3,3',4,4'-tetracarboxylic dianhydride dissolved in N,N-dimethylformamide was used as the first solution A1. As a result, a first polymerization solution C having a higher viscosity than the first solution A1 was obtained. No bubbles were observed in the obtained first polymerization solution C.

[0287] <Example 5> In Example 5, polyamic acid was produced using a polyamic acid production system 1 having a structure as shown in Figure 1. A first tank 11 contained a first solution A1 prepared by dissolving amino-terminated polyamic acid obtained by reacting 4,4'-diaminodiphenyl ether with pyromellitic dianhydride in N,N-dimethylformamide. A second tank 12 contained a second solution A2 prepared by dissolving pyromellitic dianhydride in N,N-dimethylformamide.

[0288] First, in the first mixing section 20, the first solution A1 supplied by the first supply pump 15 and the second solution A2 supplied by the second supply pump 16 were mixed to produce a first mixed solution B. Next, in the first reaction section 30, the first mixed solution B was stirred without contact with gas to produce a first polymerization solution C in which polyamic acid was dissolved. Specifically, the solution was stirred without contact with gas using a Kenics mixer-type static mixer (inner diameter 8 mm, length 100 mm), and then the solution was further stirred without contact with gas using another Kenics mixer-type static mixer (inner diameter 8 mm, length 235 mm) to allow the polymerization reaction to proceed. As a result, a first polymerization solution C with a higher viscosity than the first solution A1 was obtained. No air bubbles were observed in the resulting first polymerization solution C.

[0289] Example 6 In Example 6, polyamic acid was produced using a polyamic acid production system 1B having a structure as shown in FIG. 5. A first tank 11 contained a first solution A1 prepared by dissolving an acid anhydride-terminated polyamic acid obtained by reacting 4,4'-diaminodiphenyl ether with pyromellitic dianhydride in N,N-dimethylformamide. A second tank 12 contained a second solution A2 prepared by dissolving p-phenylenediamine in N,N-dimethylformamide. An in-line spectrophotometer was installed as a first viscosity measurement unit 111.

[0290] First, in the first mixing section 20, the first solution A1 supplied by the first supply pump 15 and the second solution A2 supplied by the second supply pump 16 were mixed to produce a first mixed solution B. Next, in the first reaction section 30, the first mixed solution B was stirred in a Kenics mixer-type static mixer without contact with gas, to produce a first polymerization solution C in which the polyamic acid was dissolved.

[0291] The absorbance A of a solution is expressed by the Beer-Lambert law as follows: A = εcl (3) Here, ε is the molar extinction coefficient, c is the molar concentration of the sample, and l is the optical path length. The absorbance of a polymerization solution obtained using a predetermined polymerization recipe was measured offline in advance, and a specific relationship between absorbance and viscosity was found. Specifically, the lower the absorbance at a wavelength of 490 nm, the higher the viscosity. When the target viscosity is 3200 poise, the absorbance must be 0.178. During the flow of the first solution A1 and the second solution A2, measurement information was obtained indicating an absorbance of 0.199 (equivalent viscosity: 2100 poise). Therefore, the flow rate ratio was changed to increase the flow rate of the second solution A2, adjusting the absorbance to 0.178. As a result, the viscosity of the first polymerization solution C became 3200 poise. No bubbles were observed in the resulting first polymerization solution C.

[0292] Example 7 In Example 7, polyamic acid was produced using a polyamic acid production system 1B having a structure as shown in Figure 5. A first tank 11 contained a first solution A1 in which an acid anhydride-terminated polyamic acid obtained by reacting 4,4'-diaminodiphenyl ether with pyromellitic dianhydride was dissolved in N,N-dimethylformamide. A second tank 12 contained a second solution A2 in which p-phenylenediamine was dissolved in N,N-dimethylformamide. Two pressure gauges were installed as first differential pressure measurement units 91 and 92.

[0293] First, in the first mixing section 20, the first solution A1 supplied by the first supply pump 15 and the second solution A2 supplied by the second supply pump 16 were mixed to produce a first mixed solution B. Next, in the first reaction section 30, the first mixed solution B was stirred in a Kenics mixer-type static mixer without contact with gas, to produce a first polymerization solution C in which the polyamic acid was dissolved.

[0294] The pressure loss ΔP of a solution flowing in a laminar flow in a circular pipe can be calculated using the Hagen-Poiseuille equation shown in the following equation (4). ΔP=32μLu / D 2 ···(4) Here, μ is the viscosity of the solution, L is the pipe length (the distance between the two pressure gauges), u is the average cross-sectional flow velocity of the solution, and D is the pipe diameter. Since the values ​​of ΔP, L, u, and D can be obtained, the relationship between the differential pressure and the viscosity of the solution can be calculated using the above equation (4). The distance between the two points at which the differential pressure is measured can be determined taking into account the accuracy of the pressure measurement. A preliminary investigation of the relationship between differential pressure and viscosity revealed that the viscosity increases linearly as the measured differential pressure decreases. When the target viscosity is 1500 poise, the differential pressure must be 0.6 MPa. Since measurement information indicating a differential pressure of 0.4 MPa (equivalent viscosity: 600 poise) was obtained during the flow of the first solution A1 and the second solution A2, the flow rate ratio was changed to increase the flow rate of the second solution A2, adjusting the differential pressure to 0.6 MPa. As a result, the viscosity of the first polymerized solution C was 1500 poise. No bubbles were observed in the resulting first polymerized solution C.

[0295] Example 8 In Example 8, polyamic acid was produced using a polyamic acid production system 1D having a structure as shown in Figure 13. A first tank 11 contained a first solution A1 prepared by dissolving an acid anhydride-terminated polyamic acid obtained by reacting 4,4'-diaminodiphenyl ether with pyromellitic dianhydride in N,N-dimethylformamide. A second tank 12 contained a second solution A2 prepared by dissolving p-phenylenediamine in N,N-dimethylformamide.

[0296] First, in the first mixing section 20, the first solution A1 supplied by the first supply pump 15 and the second solution A2 supplied by the second supply pump 16 were merged and mixed to produce a first mixed solution B. Next, in the first reaction section 30, the first mixed solution B was stirred without contact with gas to produce a first polymerized solution C in which polyamic acid was dissolved. Specifically, the solution was stirred without contact with gas using a Kenics mixer-type static mixer (inner diameter 8 mm, length 670 mm) to allow the polymerization reaction to proceed. The viscosity of the resulting polymerized solution at 23°C was measured using an E-type viscometer. The first flow rate fluctuation rate for the first solution A1 and the second solution A2, whose flow fluctuations were synchronized, was controlled to 1.1% and 3.6%, respectively. As a result, a first polymerized solution C (weight fraction of polyamic acid: 21%) with a uniform viscosity of 1030 poise was obtained. No bubbles were observed in the obtained first polymerization solution C.

[0297] Example 9 In Example 9, polyamic acid was produced using a polyamic acid production system 1F having a structure as shown in Figure 18. A first tank 11 contained a first solution A1 prepared by dissolving an acid anhydride-terminated polyamic acid obtained by reacting 4,4'-diaminodiphenyl ether with pyromellitic dianhydride in N,N-dimethylformamide. A second tank 12 contained a second solution A2 prepared by dissolving p-phenylenediamine in N,N-dimethylformamide.

[0298] First, in the first mixing section 20, the first solution A1 supplied by the first supply pump 15 and the second solution A2 supplied by the second supply pump 16 were merged and mixed to produce a first mixed solution B. Next, in the first reaction section 30, the first mixed solution B was stirred without contact with gas to produce a first polymerized solution C in which polyamic acid was dissolved. Specifically, the solution was stirred without contact with gas using a Kenics mixer-type static mixer (inner diameter 8 mm, length 520 mm) to allow the polymerization reaction to proceed. The viscosity of the resulting polymerized solution at 23°C was measured using an E-type viscometer. The first flow rate fluctuation rate was controlled to 0.25% and the second flow rate fluctuation rate to 0.50%, resulting in a first polymerized solution C (weight fraction of polyamic acid: 20%) with a uniform viscosity of 2410 poise. No bubbles were observed in the resulting first polymerized solution C.

[0299] Example 10 In Example 10, polyamic acid was produced using a polyamic acid production system 1F having a structure as shown in Figure 18. A first tank 11 contained a first solution A1 prepared by dissolving an acid anhydride-terminated polyamic acid obtained by reacting 4,4'-diaminodiphenyl ether with pyromellitic dianhydride in N,N-dimethylformamide. A second tank 12 contained a second solution A2 prepared by dissolving p-phenylenediamine in N,N-dimethylformamide.

[0300] First, in the first mixing section 20, the first solution A1 supplied by the first supply pump 15 and the second solution A2 supplied by the second supply pump 16 were merged and mixed to produce a first mixed solution B. Next, in the first reaction section 30, the first mixed solution B was stirred without contact with gas to produce a first polymerized solution C in which polyamic acid was dissolved. Specifically, the solution was stirred without contact with gas using a Kenics mixer-type static mixer (inner diameter 8 mm, length 520 mm) to allow the polymerization reaction to proceed. The viscosity of the resulting polymerized solution at 23°C was measured using an E-type viscometer. The first flow rate fluctuation rate was controlled to 0.32% and the second flow rate fluctuation rate to 0.40%, resulting in a first polymerized solution C (weight fraction of polyamic acid: 20%) with a uniform viscosity of 5700 poise. No bubbles were observed in the resulting first polymerized solution C.

[0301] <Comparative Example 1> An anhydride-terminated polyamic acid obtained by the reaction of 4,4'-diaminodiphenyl ether and pyromellitic dianhydride was placed in a 3 L separable flask. Then, while stirring the solution in the flask at 200 rpm with a 45-degree inclined paddle blade, a solution containing p-phenylenediamine was added dropwise to promote the polymerization reaction of the polyamic acid so that the weight fraction of the polyamic acid was 18%. The viscosity of the resulting polymerization solution at 23°C was measured using an E-type viscometer and found to be 2000 poise. After 1 hour of polymerization, the solution contained air bubbles and was not easily degassed even when left to stand. [Explanation of symbols]

[0302] 1. Polyamic acid production system 11 First Tank 12 Second Tank 15 First supply pump (first supply section) 16 Second supply pump (second supply section) 20 1st mixing section 30 First reaction section 40 First cushion tank A1 First solution A2 2nd solution B 1st mixed solution C 1st polymerization solution L Liquid transfer line

Claims

1. A polyamic acid production system for producing a polyamic acid using as raw materials a first solution in which a first polymerizable compound having polyaddition properties is dissolved and a second solution in which a second polymerizable compound having polyaddition properties that undergoes polyaddition with the first polymerizable compound is dissolved, the system comprising: a first supply unit that supplies the first solution; a second supply unit that supplies the second solution; a first mixing section that mixes the first solution and the second solution by joining them together in a sealed tube without contacting them with gas, thereby generating a first mixed solution; a first reaction section in which the first mixed solution is stirred in a sealed tube without contact with gas, and a polymerization reaction between the first polymerizable compound and the second polymerizable compound is allowed to proceed, thereby producing a first polymerized solution in which a polyamic acid is dissolved; a first control unit that controls the supply of the first solution and / or the second solution, the first mixing section is a connection section between a tubular liquid feed line through which the first solution is passed, a tubular liquid feed line through which the second solution is passed, and a tubular liquid feed line through which the first mixed solution is passed, The polyamic acid production system, wherein the first reaction section includes a static mixer.

2. a first measurement unit that acquires one or more pieces of first reaction information related to a physical quantity and / or a composition of any one or more of the first solution, the second solution, the first mixed solution, and the first polymerization solution; 2. The polyamic acid production system according to claim 1, wherein the first control unit controls the supply in the first supply unit and / or the second supply unit based on the first reaction information acquired by the first measurement unit.

3. 3. The polyamic acid production system according to claim 2, wherein the first measurement unit includes one or more devices selected from the group consisting of a viscometer, a pressure gauge, a pump pressure gauge, an absorptiometer, an infrared spectrometer, a near-infrared spectrometer, a densitometer, a color difference meter, a refractometer, a spectrophotometer, a conductivity meter, a turbidity meter, and an X-ray fluorescence analyzer.

4. 4. The polyamic acid production system according to claim 1, wherein the first control unit controls the flow rate fluctuation rates of the first solution and / or the second solution so that a difference between a flow rate fluctuation rate of the first solution and a flow rate fluctuation rate of the second solution becomes small.

5. 5. The polyamic acid production system according to claim 4, wherein the first control unit controls the flow rate fluctuation of the first solution and the flow rate fluctuation of the second solution so as to be synchronized.

6. 6. The polyamic acid production system according to claim 1, wherein the first control unit controls the flow rate fluctuation rate of the first solution to be equal to or less than a first threshold value, and controls the flow rate fluctuation rate of the second solution to be equal to or less than a second threshold value.

7. 7. The polyamic acid production system according to claim 1, wherein one of the first polymerizable compound and the second polymerizable compound is a tetracarboxylic dianhydride, and the other is a diamine.

8. 7. The polyamic acid production system according to claim 1, wherein one of the first polymerizable compound and the second polymerizable compound is an acid anhydride-terminated or amino-terminated polyamic acid, and the other is a diamine or a tetracarboxylic dianhydride.

9. the polyamic acid contained in the first polymerization solution is an acid anhydride-terminated or amino-terminated polyamic acid, a third supply unit that supplies a third solution in which a diamine or a tetracarboxylic dianhydride that is to be polyadded to the acid anhydride-terminated or amino-terminated polyamic acid contained in the first polymerization solution is dissolved; a second mixing section that mixes the first polymerization solution and the third solution by joining them together in a sealed pipe without contacting them with gas, thereby producing a second mixed solution; a second reaction section for stirring the second mixed solution in a sealed tube without contact with gas, and for causing a polymerization reaction between the acid anhydride-terminated or amino-terminated polyamic acid from the first polymerization solution contained in the second mixed solution and the diamine or tetracarboxylic dianhydride from the third solution, thereby producing a second polymerized solution in which the polyamic acid is dissolved, the second mixing section is a connecting section among a tubular liquid feed line through which the first polymerization solution is passed, a tubular liquid feed line through which the third solution is passed, and a tubular liquid feed line through which the second mixed solution is passed, 9. The polyamic acid production system according to claim 1, wherein the second reaction section includes a static mixer.

10. The polyamic acid production system according to any one of claims 1 to 9, an imidization unit that imidizes the polyamic acid produced by the polyamic acid production system.

11. A method for producing a polyamic acid using as raw materials a first solution in which a first polymerizable compound having polyaddition properties is dissolved, and a second solution in which a second polymerizable compound having polyaddition properties that undergoes polyaddition with the first polymerizable compound is dissolved, the method comprising the steps of: a first supplying step of supplying the first solution; a second supplying step of supplying the second solution; a first mixing step of mixing the first solution and the second solution by joining them together in a sealed tube without contacting them with gas to produce a first mixed solution; a first reaction step of stirring the first mixed solution in a sealed tube without contact with gas to cause a polymerization reaction between the first polymerizable compound and the second polymerizable compound to proceed, thereby producing a first polymerization solution in which a polyamic acid is dissolved; a first control step of controlling the supply of the first solution and / or the second solution, In the first mixing step, the first solution and the second solution are mixed at a connection portion between a tubular liquid feed line through which the first solution is passed, a tubular liquid feed line through which the second solution is passed, and a tubular liquid feed line through which the first mixed solution is passed, to generate the first mixed solution; In the first reaction step, the first mixed solution is agitated by passing it through a static mixer to produce the first polymerization solution.

12. a first measurement step of acquiring one or more pieces of first reaction information relating to a physical quantity and / or a composition of any one or more of the first solution, the second solution, the first mixed solution, and the first polymerization solution; 12. The method for producing a polyamic acid according to claim 11, wherein the first control step controls the supply in the first supply step and / or the second supply step based on first reaction information acquired in the first measurement step.

13. 13. The method for producing a polyamic acid according to claim 12, wherein in the first measurement step, the first reaction information is acquired by one or more devices selected from the group consisting of a viscometer, a pressure meter, a pump pressure meter, an absorptiometer, an infrared spectrometer, a near-infrared spectrometer, a densitometer, a color difference meter, a refractometer, a spectrophotometer, a conductivity meter, a turbidity meter, and an X-ray fluorescence analyzer.

14. 14. The method for producing a polyamic acid according to claim 11, wherein in the first control step, a flow rate fluctuation rate of the first solution and / or the second solution is controlled so that a difference between a flow rate fluctuation rate of the first solution and a flow rate fluctuation rate of the second solution becomes small.

15. 15. The method for producing a polyamic acid according to claim 14, wherein the first control step controls the flow rate fluctuation of the first solution and the flow rate fluctuation of the second solution so as to be synchronized.

16. 16. The method for producing a polyamic acid according to claim 11, wherein in the first control step, a flow rate fluctuation rate of the first solution is controlled to be equal to or less than a first threshold value, and a flow rate fluctuation rate of the second solution is controlled to be equal to or less than a second threshold value.

17. The method for producing a polyamic acid according to any one of claims 11 to 16, wherein one of the first polymerizable compound and the second polymerizable compound is a tetracarboxylic dianhydride, and the other is a diamine.

18. The method for producing a polyamic acid according to any one of claims 11 to 16, wherein one of the first polymerizable compound and the second polymerizable compound is an acid anhydride-terminated or amino-terminated polyamic acid, and the other is a diamine or a tetracarboxylic dianhydride.

19. the polyamic acid contained in the first polymerization solution is an acid anhydride-terminated or amino-terminated polyamic acid, a third supplying step of supplying a third solution in which a diamine or a tetracarboxylic dianhydride to be polyadded to the acid anhydride-terminated or amino-terminated polyamic acid contained in the first polymerization solution is dissolved; a second mixing step of mixing the first polymerization solution and the third solution by joining them together in a sealed pipe without contacting them with gas to produce a second mixed solution; a second reaction step of stirring the second mixed solution in a sealed tube without contact with gas, and causing a polymerization reaction between the acid anhydride-terminated or amino-terminated polyamic acid from the first polymerization solution contained in the second mixed solution and the diamine or tetracarboxylic dianhydride from the third solution, thereby producing a second polymerized solution in which the polyamic acid is dissolved, In the second mixing step, the first polymerization solution and the third solution are mixed at a connecting portion between a tubular liquid feed line through which the first polymerization solution is passed, a tubular liquid feed line through which the third solution is passed, and a tubular liquid feed line through which the second mixed solution is passed, to generate the second mixed solution; 19. The method for producing a polyamic acid according to claim 11, wherein the second reaction step comprises agitating the second mixed solution by passing it through a static mixer to produce the second polymerization solution.

20. a polyamic acid production step of producing a polyamic acid by the production method according to any one of claims 11 to 19; an imidization step of imidizing the polyamic acid produced in the polyamic acid production step.

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