JP5228327B2 - Method for producing polymer solution - Google Patents

Description

  The present invention relates to a method for producing a uniform polymer solution that does not generate undissolved substances.

  Flat panel displays typified by liquid crystal displays, organic EL, PDP, and the like are thin and light in weight and meet market needs. They are rapidly spreading and their range of use is expanding. In these flat panel displays, a number of polymer films are used, for example, plastic substrate film, polarizer protective film, retardation film, viewing angle compensation film, light diffusion film, light reflection film, electromagnetic wave shielding film, It is used for display surface protection films. In general, these polymer films are required to have very high transparency, excellent surface smoothness, and thickness accuracy so as not to deteriorate the visibility of the display.

  On the other hand, a polymer composed of a fumaric acid diester was discovered by Otsu et al. In 1981 (see, for example, Non-Patent Document 1), and optical materials such as optical lenses, prism lenses, and optical fibers have been proposed (for example, Patent Documents). 1 and 2). In addition, a polymer alignment film substrate for a liquid crystal display using a monomolecular film of a fumaric acid diester polymer (for example, see Patent Document 3) is disclosed, and a method for producing an ultrathin film of a fumaric acid diester polymer is also disclosed. Applications such as electrical elements, patterning, microlithography, and optical elements (optical waveguides, binder resins for nonlinear tertiary elements) have been proposed (see, for example, Patent Document 4). Furthermore, a low dielectric polymer material, a film, a substrate and an electronic component made of a fumaric acid diester polymer are disclosed, and a film by a solution casting method is also proposed. (For example, refer to Patent Document 5).

  In order to obtain a film having very high transparency and excellent surface smoothness and thickness accuracy by the solution casting method, it is necessary to produce a polymer solution in which the polymer is uniformly dissolved and free from foreign matters such as undissolved substances.

Japanese Patent Laid-Open No. 61-028513 JP 61-034007 A Japanese Patent Laid-Open No. 02-214731 Japanese Patent Laid-Open No. 02-269130 JP 09-208627 A Radical polymerization handbook (page 314), ST

  However, the fumaric acid diester polymer has poor solubility in a solvent, and even when dissolved, the polymer solution has a high viscosity. Therefore, it is difficult to produce a polymer solution that dissolves uniformly and has no undissolved material. .

  Accordingly, an object of the present invention is to provide a method for producing a uniform polymer solution free from undissolved substances.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have used a stirring tank equipped with a specific stirring blade when dissolving the polymer, and further set the specific stirring conditions so that the polymer is not dissolved. The inventors have found that a uniform polymer solution can be produced without any object, and have completed the present invention.

  That is, the present invention is a stirring tank provided with a disper type stirring blade, and the peripheral speed of stirring is 10 to 25 m / sec. Further, the present invention relates to a method for producing a polymer solution, wherein the polymer is dissolved under stirring with a setting such that the ratio (Q / V) of the discharge flow rate Q to the solution amount V is 7 to 30.

  Hereafter, the manufacturing method of the polymer solution of this invention is demonstrated in detail.

  In the method for producing a polymer solution of the present invention, the polymer is dissolved using a stirring tank equipped with a disper type stirring blade. Here, the disper-type stirring blade is a disk-shaped stirring blade having a shape that is obtained by alternately bending a circular saw blade up and down, for example, one having the shape shown in FIG. . By using the stirring blade, a large shearing effect can be given to the solution in the vicinity of the blade of the stirring blade, and the ability to uniformly disperse the polymer charged in the solvent into the solvent is high. It is a stirring blade excellent in manufacturing. For the stirring blades other than the disperser type, the propeller type and anchor type have a small shearing action, so that it is easy to produce polymer aggregates that have been put into the solvent, and it is also difficult to disassemble the aggregates once generated. For this reason, undissolved substances remain in the solution, and it is difficult to produce a uniformly dissolved polymer solution.

  In the method for producing a polymer solution in a stirring vessel equipped with a disper-type stirring blade according to the present invention, it is important that the polymer does not settle and is uniformly dispersed, so that the peripheral speed of stirring is 10 to 25 m / sec. And preferably 15 to 23 m / sec. , Particularly preferably 17 to 21 m / sec. It is. The peripheral speed is 10 m / sec. If the amount is less than 1, the polymer is not uniformly dispersed in the solvent and aggregates are formed, and the fluidity of the entire system is reduced, so that undissolved matter remains after dissolution, and a solution with good solubility is obtained. It is difficult. The peripheral speed is 25 m / sec. Exceeding this causes the solution to be splattered during stirring, and the equipment load of the stirring tank increases, making the dissolution operation difficult. Here, the peripheral speed (m / sec.) Is represented by the product of the rotational speed (rpm) and the circumference (m) of the stirring blade.

  The ratio of the discharge flow rate Q to the solution amount V (hereinafter Q / V) is 7-30, preferably 10-25. When Q / V is less than 7, the polymer is not uniformly dispersed in the solvent and aggregates are formed, and the fluidity of the entire system is reduced, so that undissolved matter remains after dissolution, and the solubility is good It is difficult to obtain a simple solution. When Q / V exceeds 30, scattering of the solution becomes intense at the time of stirring, and the equipment load of the stirring tank becomes large, so that the dissolving operation becomes difficult. Here, the discharge flow rate Q is the flow rate discharged from the tip of the stirring blade, and the solution amount V represents the total amount of the polymer and solvent used in the production of the solution.

  In the method for producing the polymer solution of the present invention, there is no particular limitation on the method for introducing the polymer into the solvent, and examples include a method for introducing the polymer into the solvent, a method for introducing the solvent into the polymer, etc. Therefore, a method in which a polymer is introduced into a solvent is preferable. In that case, if it takes a long time to charge the polymer, the viscosity of the solution increases greatly due to the dissolution of the polymer, so that the polymer charged later is not easily dispersed in the solution, and undissolved substances are easily formed. It is preferred to end the polymer charge before the increase is significant.

  In the method for producing a polymer solution of the present invention, the ratio of the diameter d of the stirring blade to the inner diameter D of the stirring tank (hereinafter referred to as d / D) is preferably 0.4 to 0.6.

  The solvent used in the present invention is not particularly limited as long as the polymer can be uniformly dissolved and a colorless and transparent solution can be obtained. For example, aromatic hydrocarbons such as toluene and xylene; acetone, methyl ethyl ketone, cyclohexane Ketones such as hexanone; ethers such as tetrahydrofuran and dioxane; esters such as ethyl acetate and butyl acetate; halogenated hydrocarbons such as dichloromethane and chloroform. Further, the solvent may be a single solvent or a mixed solvent of two or more kinds, and the mixing ratio of the solvent is arbitrary as long as a colorless and transparent solution is obtained. Of these, toluene, xylene, and tetrahydrofuran are preferable from the viewpoint of solubility of the polymer, and a mixed solvent obtained by adding acetone or methyl ethyl ketone to toluene or xylene is preferable from the viewpoint of drying characteristics when forming a film.

  In the method for producing a polymer solution of the present invention, the concentration of the polymer and the solvent is not particularly limited as long as the polymer is dissolved under a specific stirring condition in a stirring tank equipped with a disperse type stirring blade. For example, polymer / solvent = 15/85 to 25/75 (weight ratio) is preferable.

  In the method for producing a polymer solution of the present invention, there is no particular limitation on the temperature setting such as heating or cooling of the stirring tank during dissolution, and it can be arbitrarily set according to the boiling point of the solvent used. However, since the solution viscosity decreases as the temperature in the solution increases, a polymer solution having good solubility can be obtained.

  The polymer dissolved in the method for producing a polymer solution of the present invention is a fumaric acid diester polymer, and any polymer can be used as long as it belongs to the category of fumaric acid diester polymers. Among them, the following general formula ( The fumaric acid diester residue shown in 1) is preferably 50 mol% or more, particularly preferably 80 mol% or more, and more preferably 90 mol% or more.

（ここで、Ｒ_１、Ｒ_２はそれぞれ独立して炭素数１〜１２の直鎖アルキル基、炭素数３〜１２の分岐アルキル基または環状アルキル基である。）
ここで、Ｒ_１、Ｒ_２はそれぞれ独立して炭素数１〜１２の直鎖アルキル基、炭素数３〜１２の分岐アルキル基または環状アルキル基であり、これらはフッ素、塩素などのハロゲン基；エーテル基；エステル基もしくはアミノ基で置換されていてもよい。

(Here, R ₁ and R ₂ are each independently a linear alkyl group having 1 to 12 carbon atoms, a branched alkyl group having 3 to 12 carbon atoms, or a cyclic alkyl group.)
Here, R ₁ and R ₂ are each independently a linear alkyl group having 1 to 12 carbon atoms, a branched alkyl group having 3 to 12 carbon atoms or a cyclic alkyl group, and these are halogen groups such as fluorine and chlorine; Ether group; optionally substituted with an ester group or an amino group.

Examples of the linear alkyl group having 1 to 12 carbon atoms in R ₁ and R ₂ include a methyl group, an ethyl group, a propyl group, an n-butyl group, an n-pentyl group, and an n-hexyl group. Examples of the 3-12 branched alkyl group include isopropyl group, isobutyl group, sec-butyl group, tert-butyl group, isopentyl group, sec-pentyl group, tert-pentyl group, 2-ethylhexyl group and the like. Examples of the cyclic alkyl group having 3 to 12 include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group. Among these, an isopropyl group, a tert-butyl group, a cyclopentyl group, and a cyclohexyl group are preferable, and an isopropyl group is particularly preferable.

  Specific examples of the fumaric acid diester residue represented by the general formula (1) include dimethyl fumarate residue, diethyl fumarate residue, dipropyl fumarate residue, diisopropyl fumarate residue, di-n-fumarate residue. Butyl residue, diisobutyl fumarate residue, di-sec-butyl fumarate residue, di-tert-butyl fumarate residue, di-n-pentyl fumarate residue, di-isopentyl fumarate residue, fumaric acid Di-sec-pentyl residue, di-tert-pentyl fumarate residue, di-n-hexyl fumarate residue, bis- (2-ethylhexyl) fumarate residue, dicyclopropyl fumarate residue, fumaric acid Dicyclobutyl residue, dicyclopentyl fumarate residue, dicyclohexyl fumarate residue, etc., among them diisopropyl fumarate residue, di-fumarate ert- butyl residues, fumarate dicyclopentyl residues, preferably fumaric acid dicyclohexyl residues, especially diisopropyl fumarate residue are preferred. Moreover, 1 type or 2 types or more may be contained.

  The fumaric acid diester polymer may contain other monomer residues. Examples of the other monomer residues include styrene residues such as styrene residues and α-methylstyrene residues. (Meth) acrylic acid residue; (meth) acrylic acid methyl residue, (meth) ethyl acrylate residue, (meth) acrylic acid butyl residue, oxetanyl group represented by the following general formula (2) (Meth) acrylic acid ester residues such as (meth) acrylic acid ester residues such as (meth) acrylic acid ester residues having a tetrahydrofurfuryl group represented by the following general formula (3); vinyl acetate residues Vinyl ester residues such as vinyl propionate residues; acrylonitrile residues; methacrylonitrile residues; methyl vinyl ether residues, ethyl vinyl ether residues, butyl vinyl ether residues Vinyl ether residues: N-substituted maleimide residues such as N-methylmaleimide residue, N-cyclohexylmaleimide residue and N-phenylmaleimide residue; olefin residues such as ethylene residue and propylene residue; 1 type or 2 types or more chosen from more can be mentioned. Among these, other monomer residues include a (meth) acrylic acid ester residue having an oxetanyl group represented by the following general formula (2) and a tetrahydrofurfuryl group represented by the following general formula (3). A (meth) acrylic acid ester residue is preferred.

（ここで、Ｒ_３は水素、メチル基であり、Ｒ_４は水素、炭素数１〜４の直鎖アルキル基、分岐アルキル基を示す。ｎは１または２を示す。）

(Here, R ₃ represents hydrogen or a methyl group, R ₄ represents hydrogen, a linear alkyl group having 1 to 4 carbon atoms, or a branched alkyl group. N represents 1 or 2.)

（ここで、Ｒ_５は水素、メチル基であり、Ｒ_６は水素、炭素数１〜４の直鎖アルキル基、分岐アルキル基を示す。）
ここで一般式（２）のＲ_３は水素、メチル基であり、Ｒ_４は水素、炭素数１〜４の直鎖アルキル基、分岐アルキル基であり、ｎは１または２である。Ｒ_４における炭素数１〜４の直鎖アルキル基としては、例えばメチル基、エチル基、プロピル基、ｎ−ブチル基等が挙げられ、炭素数１〜４の分岐アルキル基としては、例えばイソプロピル基、イソブチル基、ｓｅｃ−ブチル基、ｔｅｒｔ−ブチル基等が挙げられる。そして、具体的な一般式（２）で示されるオキセタニル基を有する（メタ）アクリル酸エステル残基としては、例えば（メタ）アクリル酸３−メチル−３−オキセタニルメチル残基、（メタ）アクリル酸３−エチル−３−オキセタニルメチル残基、（メタ）アクリル酸３−エチル−３−オキセタニルエチル残基等が挙げられる。

(Here, R ₅ represents hydrogen or a methyl group, and R ₆ represents hydrogen, a linear alkyl group having 1 to 4 carbon atoms, or a branched alkyl group.)
Here, R ₃ in the general formula (2) is hydrogen or a methyl group, R ₄ is hydrogen, a linear alkyl group having 1 to 4 carbon atoms, or a branched alkyl group, and n is 1 or 2. Examples of the linear alkyl group having 1 to ₄ carbon atoms in R ₄ include a methyl group, an ethyl group, a propyl group, and an n-butyl group. Examples of the branched alkyl group having 1 to 4 carbon atoms include an isopropyl group. , Isobutyl group, sec-butyl group, tert-butyl group and the like. Examples of the (meth) acrylic acid ester residue having an oxetanyl group represented by the general formula (2) include, for example, (meth) acrylic acid 3-methyl-3-oxetanylmethyl residue, (meth) acrylic acid Examples include 3-ethyl-3-oxetanylmethyl residue, (meth) acrylic acid 3-ethyl-3-oxetanylethyl residue, and the like.

Also, R ₅ in the general formula (3) is hydrogen, methyl group, R ₆ is hydrogen, straight-chain alkyl group having 1 to 4 carbon atoms, a branched alkyl group. Examples of the linear alkyl group having 1 to 4 carbon atoms in R ₆ include a methyl group, an ethyl group, a propyl group, and a butyl group. Examples of the branched alkyl group having 1 to 4 carbon atoms include an isopropyl group and isobutyl. Group, sec-butyl group, tert-butyl group and the like. Examples of the (meth) acrylic acid ester residue having a tetrahydrofurfuryl group represented by the general formula (3) include, for example, tetrahydrofurfuryl acrylate residue, 2-methyltetrahydrofurfuryl acrylate residue, An acrylic acid 2-ethyltetrahydrofurfuryl residue etc. are mentioned.

  The fumaric acid diester polymer used as the polymer of the present invention has a standard polystyrene equivalent number average molecular weight of 50,000 to 250 obtained from an elution curve measured by gel permeation chromatography (hereinafter referred to as GPC). , 000 is preferable.

  The fumarate diester polymer used as the polymer of the present invention is, for example, dimethyl fumarate, diethyl fumarate, dipropyl fumarate, diisopropyl fumarate, di-n-butyl fumarate, diisobutyl fumarate, di-fumarate. sec-butyl, di-tert-butyl fumarate, di-n-pentyl fumarate, di-isopentyl fumarate, di-sec-pentyl fumarate, di-tert-pentyl fumarate, di-n-hexyl fumarate, It can be produced by radical polymerization of fumaric acid diesters such as bis- (2-ethylhexyl) fumarate, dicyclopropyl fumarate, dicyclobutyl fumarate, dicyclopentyl fumarate and dicyclohexyl fumarate.

  When the fumaric acid diester polymer contains other monomer residues, the fumaric acid diesters and styrenes such as styrene and α-methylstyrene; (meth) acrylic acid (Meth) such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, (meth) acrylic acid ester having an oxetanyl group, (meth) acrylic acid ester having a tetrahydrofurfuryl group Acrylic esters; vinyl esters such as vinyl acetate and vinyl propionate; acrylonitrile; methacrylonitrile; vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, butyl vinyl ether; N-methylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide N-substituted maleimides such as Ethylene, olefins such as propylene or the like can be obtained to radical copolymerization.

  For the radical polymerization or radical copolymerization, any of known polymerization methods such as bulk polymerization, solution polymerization, suspension polymerization, precipitation polymerization, and emulsion polymerization can be employed.

  In the method for producing a polymer solution of the present invention, other polymers, surfactants, polymer electrolytes, conductive complexes, inorganic fillers, pigments, dyes, antioxidants, light stabilizers, ultraviolet rays are used within the scope of the invention. Absorbers, photocationic initiators, thermal cation initiators, antistatic agents, antiblocking agents, lubricants, plasticizers, and the like may be blended.

  The polymer solution produced by the present invention can be formed into a film by applying it onto a substrate such as a polyethylene terephthalate film or a metal plate by a method generally known as a solution casting method. Furthermore, foreign matters can be removed by passing the polymer solution through a filter before coating, and a film having high transparency, excellent surface smoothness and thickness accuracy can be obtained.

  According to the method for producing a polymer solution of the present invention, it is possible to produce a polymer solution suitable for a solution film forming method for producing a polymer film that requires high transparency, excellent surface smoothness, and thickness accuracy.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these Examples. Unless otherwise noted, commercially available reagents were used.

  In addition, the various physical properties shown by an Example were measured with the following method.

~ Measurement of number average molecular weight ~
Using a gel permeation chromatography (GPC) apparatus (manufactured by Tosoh Corporation, trade name C0-8011 (column; equipped with trade name GMH _HR- H)), measured at 40 ° C. using tetrahydrofuran as a solvent, standard polystyrene equivalent value As sought.

~ Fumaric acid diester polymer composition ~
Using a nuclear magnetic resonance measuring apparatus (manufactured by JEOL, trade name JNM-GX270), it was determined by proton nuclear magnetic resonance spectroscopy ( ¹ H-NMR) spectrum analysis.

~ Measurement of solution viscosity ~
The measurement was performed at 30 ° C. using a spindle type viscometer (trade name TV-20, manufactured by Toki Sangyo Co., Ltd.).

Synthesis Example 1 (Synthesis of fumaric acid diester polymer)
In a 5 L autoclave equipped with a stirrer, a condenser tube, a nitrogen inlet tube and a thermometer, hydroxypropylmethylcellulose (manufactured by Shin-Etsu Chemical Co., Ltd., trade name Metroze 60SH-50) 4 g, distilled water 26000 g, diisopropyl fumarate 1400 g, and polymerization initiator 7 g of a certain t-butyl peroxypivalate was added, nitrogen bubbling was performed for 1 hour, and then radical suspension polymerization was performed by maintaining at 50 ° C. for 24 hours while stirring at 450 rpm. After cooling to room temperature, the resulting suspension containing polymer particles was centrifuged. The obtained polymer particles were washed twice with distilled water and twice with methanol, and then dried under reduced pressure at 80 ° C. (yield: 75%).

  The number average molecular weight of the obtained diisopropyl fumarate homopolymer was 120,000.

Synthesis Example 2 (Synthesis of fumaric acid diester polymer)
In a 50 L autoclave equipped with a stirrer, a condenser tube, a nitrogen inlet tube and a thermometer, 40 g of hydroxypropylmethylcellulose (manufactured by Shin-Etsu Chemical Co., Ltd., trade name Metroze 60SH-50), 26000 g of distilled water, 13750 g of diisopropyl fumarate, 3-ethyl acrylate -3-Ocetanylmethyl 250 g and polymerization initiator t-butyl peroxypivalate 80 g were added, nitrogen bubbling was performed for 1 hour, and then the suspension was maintained at 50 ° C. for 24 hours while stirring at 200 rpm. Was done. After cooling to room temperature, the resulting suspension containing polymer particles was centrifuged. The obtained polymer particles were washed twice with distilled water and twice with methanol, and then dried under reduced pressure at 80 ° C. (yield: 81%).

¹ H-NMR measurement confirmed that the diisopropyl fumarate copolymer was diisopropyl fumarate residue / 3-ethyl-3-oxetanylmethyl acrylate residue = 97/3 (mol%). The number average molecular weight of the obtained diisopropyl fumarate copolymer was 150,000.

Example 1
In a stirring tank equipped with a disperse type stirring blade, 3.8 g of phenolic antioxidant (trade name AO-60, manufactured by Asahi Denka Co., Ltd.), phosphorous oxidation in a mixed solvent consisting of 2.2 kg of toluene and 2.2 kg of methyl ethyl ketone 11.7 g of an inhibitor (manufactured by Asahi Denka, trade name PEP-36) was added, and the peripheral speed was 24 m / sec. In addition, the ratio of the discharge flow rate Q to the solution amount V (hereinafter Q / V) 12 and the ratio of the diameter d of the stirring blade to the inner diameter D of the stirring tank (hereinafter referred to as d / D) 0.42 After adding 1.1 kg of the fumaric acid diester polymer obtained in Synthesis Example 1, stirring was continued at room temperature for 1 hour to obtain a polymer solution. The solution viscosity of the obtained solution was 2700 cP, and undissolved matter was not observed visually, and it confirmed that it was a uniform polymer solution.

Example 2
In a stirring tank equipped with a disperse type stirring blade, 0.9 g of phenolic antioxidant (trade name AO-60, manufactured by Asahi Denka Co., Ltd.), phosphorus-based oxidation was added to a mixed solvent consisting of 0.5 kg of toluene and 0.5 kg of methyl ethyl ketone. 2.7 g of an inhibitor (trade name PEP-36 manufactured by Asahi Denka) was added, and the peripheral speed was 19 m / sec. In addition, 0.25 kg of the fumaric acid diester polymer obtained in Synthesis Example 1 was added under stirring conditions of Q / V = 27 and d / D = 0.53, and then stirred at room temperature for 1 hour. Subsequently, a polymer solution was obtained. The solution viscosity of the obtained solution was 2900 cP, and undissolved matter was not observed visually, and it confirmed that it was a uniform polymer solution.

Example 3
In a stirring tank equipped with a disper type stirring blade, a peripheral speed of 10 m / sec. Was added to a mixed solvent consisting of 50 g of toluene and 50 g of methyl ethyl ketone. In addition, 25 g of the fumaric acid diester polymer obtained in Synthesis Example 2 was added under the stirring condition of Q / V = 22 and d / D = 0.57, and then the stirring was continued at room temperature for 1 hour. A polymer solution was obtained. The solution viscosity of the obtained solution was 3000 cP, and undissolved matter was not observed visually, and it confirmed that it was a uniform polymer solution.

Example 4
In a stirring tank equipped with a disper type stirring blade, a peripheral speed of 18 m / sec. Was added to a mixed solvent consisting of 4.2 kg of toluene and 4.2 kg of methyl ethyl ketone. In addition, 2.1 kg of the fumaric acid diester polymer obtained in Synthesis Example 2 was added under stirring conditions of Q / V = 7.6 and d / D = 0.46, and then at room temperature for 1 hour. Stirring was continued to obtain a polymer solution. The solution viscosity of the obtained solution was 3000 cP, and undissolved matter was not observed visually, and it confirmed that it was a uniform polymer solution.

Comparative Example 1
In a stirring tank equipped with a disper type stirring blade, a mixed solvent consisting of 0.46 kg of toluene and 0.46 kg of methyl ethyl ketone, 0.8 g of a phenolic antioxidant (trade name AO-60, manufactured by Asahi Denka), phosphorus-based oxidation 2.4 g of an inhibitor (trade name PEP-36 manufactured by Asahi Denka) was added, and the peripheral speed was 9.1 m / sec. In addition, 0.23 kg of the fumaric acid diester polymer obtained in Synthesis Example 1 was added under stirring conditions of Q / V = 7.7 and d / D = 0.50, and then at room temperature for 1 hour. Stirring was continued to obtain a polymer solution. The solution viscosity of the obtained solution was 3800 cP, and undissolved substances were visually observed.

Comparative Example 2
In a stirring tank equipped with a disper type stirring blade, a peripheral speed of 26 m / sec. Was added to a mixed solvent consisting of 4.6 kg of toluene and 4.6 kg of methyl ethyl ketone. In addition, 2.3 kg of the fumaric acid diester polymer obtained in Synthesis Example 1 was added under stirring conditions of Q / V = 19 and d / D = 0.65, followed by stirring at room temperature for 1 hour. Subsequently, a polymer solution was obtained. The solution viscosity of the obtained solution was 3600 cP, and undissolved matter (scattered polymer) was visually observed.

Comparative Example 3
In a stirring tank equipped with a disper type stirring blade, a mixed solvent consisting of 2.0 kg of toluene and 2.0 kg of methyl ethyl ketone, 3.5 g of a phenol-based antioxidant (trade name AO-60, manufactured by Asahi Denka), phosphorus-based oxidation 10 g of an inhibitor (trade name PEP-36, manufactured by Asahi Denka) was added, and the peripheral speed was 18 m / sec. In addition, 1.0 kg of the fumaric acid diester polymer obtained in Synthesis Example 2 was added under stirring conditions of Q / V = 6.5 and d / D = 0.33, and then at room temperature for 1 hour. Stirring was continued to obtain a polymer solution. The solution viscosity of the obtained solution was 4000 cP, and undissolved substances were visually observed.

Comparative Example 4
In a stirring tank equipped with a disper type stirring blade, a peripheral speed of 15 m / sec. Was added to a mixed solvent composed of 60 g of toluene and 60 g of methyl ethyl ketone. In addition, under the stirring conditions of Q / V = 31 and d / D = 0.53, 30 g of the fumaric acid diester polymer obtained in Synthesis Example 2 was added, and stirring was continued at room temperature for 1 hour. A polymer solution was obtained. The solution viscosity of the obtained solution was 3500 cP, and undissolved matter (scattered polymer) was visually observed.

An example of a disperser type stirring blade

Claims (2)

This is a stirring tank equipped with a disperse type stirring blade, and the peripheral speed of stirring is 10 to 25 m / sec. And the ratio (Q / V) of the discharge flow rate Q to the solution amount V is 7 to 30 min. Under the stirring given the setting of ^-1 , the polymer, which is a polymer composed of 50 mol% or more of the fumaric acid diester residue represented by the following general formula (1), is dissolved in aromatic hydrocarbons, ketones, ethers A method for producing a polymer solution, which is carried out using a single solvent selected from the group consisting of esters, esters and halogenated hydrocarbons, or using two or more kinds of mixed solvents.

(Wherein R ₁ and R ₂ are each independently a linear alkyl group having 1 to 12 carbon atoms, a branched alkyl group having 3 to 12 carbon atoms or a cyclic alkyl group, and these are halogen groups which are fluorine and chlorine. Ether group; may be substituted with ester group or amino group) The polymer solution is produced according to claim 1, wherein the polymer is dissolved at a ratio (d / D) of the diameter d of the stirring blade and the inner diameter D of the stirring tank set to 0.4 to 0.6. Method.

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