JP5314856B2 - Method for producing polyimide compound - Google Patents

Description

  The present invention relates to a method for producing a polyimide compound.

  The polyimide compound soluble in the solvent is formed by addition polymerization of an acid dianhydride monomer and a diamine monomer in a polar solvent such as triglyme or γ-butyrolactone, and then a cyclized dehydration reaction. Can be synthesized by imidization.

  However, in the case of a polyimide compound in which a polar group is introduced by using a monomer having a polar group such as a hydroxyl group, an amide group, a carboxylic acid group, or a sulfonic acid group and is soluble in the solvent, a solvent such as triglyme or γ-butyrolactone Is used, the viscosity of the reaction solution increases during solution imidization due to the interaction (hydrogen bonding) between polar groups introduced into the main chain of the polyimide compound. Then, the reaction solution having an increased viscosity is lifted on the shaft of the stirrer by the Weisenberg effect. Therefore, the imidization reaction must be interrupted.

  In order to suppress such a phenomenon of rising of the reaction solution, various methods shown below have been proposed. For example, there is a method for producing a good varnish by adding a salt such as lithium bromide when imidization and inhibiting the main chains from hydrogen bonding via a polar group. There is also a method of reducing the proportion of polyimide solids in the solution. Further, a method has been reported in which an inert gas such as nitrogen or argon used in the synthesis is humidified, hydrogen bonds are cut with the moisture, and a good varnish is produced (for example, see Patent Document 1). .

JP 2002-12664 A

  The polyimide compound produced by the method of adding a salt at the time of imidization has an adverse effect such as a decrease in insulation resistance or conductor corrosion due to the added salt when used for an electronic material such as a semiconductor or a substrate material. The salt must be completely removed from the polyimide varnish through a purification step such as reprecipitation.

  Moreover, since the polyimide compound manufactured by the method of reducing the solid content concentration in the polyimide varnish has a low solid content concentration, it is difficult to form a thick film. In particular, this method cannot be applied in a field where a substrate material requires a film thickness of 10 μm or more, such as a solder resist or a coverlay.

  In the method described in Patent Document 1, it is difficult to manage the dew point at the time of synthesis, and it is indispensable to introduce new equipment, which is not preferable in terms of manufacturing cost.

  Accordingly, the inventors of the present invention have made extensive studies in view of the above-mentioned circumstances, and as a result, the phenomenon of the reaction solution rising can be suppressed by refluxing the water produced by the polymerization reaction into the reaction system. The manufacturing method of the polyimide compound was discovered.

That is, the method for producing a polyimide compound of the present invention is a method for producing a polyimide compound synthesized by a polymerization reaction of an acid dianhydride dissolved in a predetermined solvent, a siloxane diamine, and a diamine having a polar group. The polymerization reaction includes a first polymerization step for recovering water generated by the polymerization reaction, and a second polymerization step for refluxing water generated by the polymerization reaction. The weight of water to be generated is adjusted by the amount of diamine having a polar group to be reacted in the second polymerization step, and the weight of water in the reaction solution is 0.01 wt% or more with respect to the total weight of the reaction solution. It is characterized in that the water generated in the second polymerization step is refluxed into the reaction system so as to be in the range of 1 wt% or less.

  According to the method for producing a polyimide compound of the present invention, an increase in the viscosity of a reaction solution is suppressed by refluxing water generated by a polymerization reaction into the reaction system, thereby suppressing the phenomenon of rising of the reaction solution. it can. Moreover, a polyimide film having a film thickness of 10 μm or more is obtained by refluxing so that the weight of water generated by the polymerization reaction is in the range of 0.01 wt% to 1.1 wt% with respect to the total weight of the reaction solution. A polyimide compound having a polymerization degree as high as can be produced can be produced. Therefore, in order to suppress the phenomenon of rising of the reaction solution, it is not necessary to reduce the solid content concentration in the reaction solution, add or remove salt in the reaction solution, or introduce new equipment.

  Hereinafter, the manufacturing method of the polyimide compound of this invention is demonstrated. The present invention is not limited to the following description, and can be appropriately changed without departing from the spirit of the present invention.

  The method for producing a polyimide compound of the present invention is a reaction having a polyimide compound by refluxing water generated by a polymerization reaction in order to suppress a phenomenon in which a reaction solution rises in a polymerization reaction between an acid dianhydride and a diamine. It decreases the viscosity of the solution.

  As the acid dianhydride used in such a method for producing a polyimide compound of the present invention, any acid dianhydride can be used. For example, 3,3 ′, 4,4′-diphenylsulfonetetracarboxylic dianhydride ( Ricacid DSDA (hereinafter simply referred to as DSDA) can be used. Other acid dianhydrides include pyromellitic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 4,4 ′-(hexafluoroisopropylidene) diphthalic anhydride, 3, 4,3 ′, 4′-benzophenonetetracarboxylic dianhydride, 3,4,3 ′, 4′-biphenyltetracarboxylic dianhydride, 4,4′-oxydiphthalic anhydride, 9,9-bis [ 4- (3,4-dicarboxyphenoxy) phenyl] fluorene dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, bicyclo [2.2.2] oct-7-ene-2, Aromatic acid dianhydrides such as 3,5,6-tetracarboxylic dianhydride and alicyclic acid dianhydrides are exemplified. The amount of acid dianhydride used in the polymerization reaction may be equimolar, or more or less than the total amount of diamine having a polar group and siloxane diamine shown below. It changes suitably according to the molecular weight of the polyimide compound to do.

  As the diamine that undergoes a polymerization reaction with the acid dianhydride, a diamine having a polar group and a siloxane diamine are used. The polar group of the diamine having a polar group is a functional group having polarity, and examples thereof include a hydroxyl group, an amide group, a carboxylic acid group, and a sulfonic acid group. Any diamine having a polar group can be used as long as it has a polar group. For example, a diamine having a hydroxyl group as a polar group can be used. Examples of the diamine having a hydroxyl group include 3,3′-diamino-4,4′-dihydroxydiphenylsulfone (BSDA) or 2,2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane (Bis). -Ap-Af), 2,2-bis (3-amino-4-hydroxyphenyl) propane, 3,3'-diamino-4,4'-dihydroxydiphenylmethane, 3,3'-dihydroxy-4,4'-diamino Biphenyl, 2,4-diaminophenol, 9,9-bis (3-amino-4-hydroxyphenyl) fluorene and the like can be mentioned.

  The amount of the diamine having a polar group used for the polymerization reaction is preferably 0.1 wt% or more and 25 wt% or less based on the total weight of the acid dianhydride as a monomer, the diamine having a polar group, and the siloxane diamine. As will be described in detail below, the water that is mainly refluxed by the polymerization reaction is adjusted by the amount of the diamine having a polar group, so that the weight of the diamine having a polar group is within the above range. The weight of the generated water is in the range of 0.01 wt% to 1.1 wt% with respect to the total weight of the reaction solution. That is, when the diamine having a polar group is added to the reaction solution, the weight of water in the reaction solution easily satisfies the above range by allowing the reaction solution to reflux.

  Siloxane diamine is, for example, represented by the following structural formula 1 having at least a dimethylsilylene skeleton in the molecule (in the structural formula 1, m represents 0 or an integer of 1 or more, and n represents an integer of 1 or more). Siloxane diamine is preferred. Moreover, the siloxane diamine by which the terminal amino group was protected by the predetermined | prescribed protective group can also be used, and you may use together the siloxane diamine shown by following Structural formula 1, and the siloxane diamine by which the terminal was protected. Specific examples of such siloxane diamines include KF-8010, X-22-9409 (both manufactured by Shin-Etsu Chemical Co., Ltd.) and the like.

  The amount of the siloxane diamine used in the polymerization reaction is preferably 20 wt% or more and 80 wt% or less based on the total weight of the acid dianhydride as a monomer, the diamine having a polar group, and the siloxane diamine.

  As the solvent used in the method for producing the polyimide compound of the present invention, an aprotic polar solvent can be used. Ether solvents such as ethylene glycol dimethyl ether (TriGL), tetraglyme, dioxane, tetrahydrofuran, or a mixed solvent of these lactone solvents and ether solvents can be used.

  The amount of the solvent is such that the acid dianhydride, siloxane diamine and polar group-containing diamine are based on the total weight of the reaction solution when the acid dianhydride, siloxane diamine and polar group-containing diamine are added. The amount is preferably such that the total weight (solid content concentration) is 10 wt% or more and 60 wt% or less. By satisfy | filling this range, when forming a polyimide film from the varnish which has the polyimide compound synthesize | combined, sufficient film thickness is obtained.

  The manufacturing method of the polyimide compound of this invention can be performed using the said monomer and solvent. Details are shown below. In the method for producing a polyimide compound of the present invention, the polymerization reaction of acid dianhydride and diamine is performed so that the water in the reaction solution is in the range of 0.01 wt% to 1.1 wt% with respect to the total weight of the reaction solution. The water produced by is refluxed.

  Specifically, it is divided into a first polymerization step for recovering water generated by the polymerization reaction and a second polymerization step for refluxing water generated by the polymerization reaction. The first polymerization step is performed as necessary. It can be omitted. That is, the present invention includes two methods, a two-step method comprising a first polymerization step and a second polymerization step, and a one-step method comprising a second polymerization step.

  First, the two-step method (two-step invention method) will be described. In the first polymerization step, for example, a reaction vessel equipped with a Dean-Stark-Trap is used to recover water generated by the polymerization reaction. A reaction solution in which acid dianhydride, siloxane diamine and, if necessary, a diamine having a polar group are added to a solvent is placed in the reaction vessel, and heated at a predetermined temperature. Thereby, an acid dianhydride and diamine react to produce an amic acid (imide precursor) component, and the amic acid component undergoes ring closure (solution imidization) by proceeding with imidization in the reaction solution. . In the first polymerization step, an imide oligomer having a polymerization degree smaller than that of the polyimide compound and an intermediate of the polyimide compound is synthesized. In this case, in view of the second polymerization step, it is preferable that the acid dianhydride or diamine has an excess composition. In the case of a composition in which the acid dianhydride is excessive, an imide oligomer having an acid anhydride that reacts with the diamine at the terminal of the imide oligomer (an acid anhydride terminal imide oligomer) is obtained. On the other hand, in the case of a composition in which diamine is excessive, an end of the synthesized imide oligomer is an imide oligomer having an amino group that reacts with acid dianhydride (amino group-terminated imide oligomer).

  The solution imidization means may be any conditions as long as the cyclization dehydration reaction can be performed, and examples thereof include heating imidization in a solution and chemical imidization with a dehydrating agent. For example, in heat imidization, an azeotropic agent such as toluene and xylene is added to an imide precursor, and the mixture is heated and stirred at 180 ° C. or higher to perform a dehydration reaction of an amic acid component to form a ring-closed imide component. be able to. At this time, a tertiary catalyst such as triethylamine, a basic catalyst such as aromatic isoquinoline and pyridine, and an acid catalyst such as benzoic acid and parahydroxybenzoic acid may be added as a catalyst for imidization, if necessary. Further, for example, the amic acid can also be closed by a chemical imidizing agent such as acetic anhydride / pyridine or dicyclohexylcarbodiimide which is a dehydrating cyclization reagent.

  When the acid anhydride-terminated imide oligomer is synthesized, the process proceeds to the second polymerization step. In the second polymerization step, a reaction vessel equipped with a reflux tube is used. A solution in which a diamine having a polar group and, if necessary, a siloxane diamine are added to a reaction solution in which an acid anhydride-terminated imide oligomer is synthesized is placed in a reaction vessel equipped with a reflux tube and heated to a predetermined temperature. Since this reaction vessel is provided with a reflux pipe, water generated by the polymerization reaction is refluxed, and the polymerization reaction proceeds in a state where water is present in the reaction solution. This reflux is adjusted so that the weight of water present in the reaction solution is in the range of 0.01 wt% to 1.1 wt% with respect to the total weight of the reaction solution. This can be adjusted by the amount of the diamine having a polar group introduced in the second polymerization step and, if necessary, the amount of siloxane diamine added. On the other hand, in the case of an amino group-terminated imide oligomer, it can be adjusted by the amount of acid dianhydride charged in the second polymerization step. And when water exists in the reaction solution beyond this range, a polyimide compound having a high degree of polymerization cannot be obtained. For example, when a polyimide film is produced from a varnish having a polyimide compound, a film having a sufficient film thickness of 10 μm is formed. Cannot be formed. On the other hand, if the amount of water in the reaction solution is less than this range, the reaction solution will rise during the polymerization reaction, and the polymerization reaction must be interrupted.

  Next, the one-step method (one-step invention method) will be described. In the one-step method, a reaction vessel equipped with a reflux tube used in the second polymerization step described above is used. A reaction solution in which acid dianhydride, siloxane diamine, and diamine having a polar group are added to a solvent is placed in a reaction vessel equipped with a reflux tube and heated at a predetermined temperature. Since this reaction vessel is provided with a reflux pipe, water generated by the polymerization reaction is refluxed, and the polymerization reaction proceeds in a state where water is present in the reaction solution. This reflux is adjusted so that the weight of water present in the reaction solution is in the range of 0.01 wt% to 1.1 wt% with respect to the total weight of the reaction solution. This can be adjusted by the amount of the diamine having a polar group and the siloxane diamine introduced in the second polymerization step.

  When passing through the acid dianhydride-terminated imide oligomer generated in the first polymerization step, the weight of water in the reaction solution relative to the total weight of the reaction solution is charged when a reaction vessel equipped with a reflux tube is used. It can be calculated as a theoretical value based on the amount of diamine monomer (diamine having a polar group, siloxane diamine). This polymerization reaction produces two molecules of water per molecule of diamine monomer. On the other hand, when passing through the amino group-terminated imide oligomer produced in the first polymerization step, the weight of water in the reaction solution with respect to the total amount of the reaction solution is the amount of acid added when a reaction vessel equipped with a reflux tube is used. Based on the amount of anhydride monomer, it can be calculated as a theoretical value. This polymerization reaction produces two molecules of water per molecule of acid dianhydride monomer. By providing the reflux tube, the water produced by the polymerization reaction is in the reaction system, so the weight of water present in the reaction solution can be calculated from the amount of diamine monomer introduced when the reflux tube is provided, and the reaction A ratio of the weight of water to the total weight of the solution is obtained.

  As in the one-step method and the two-step method, the water produced by the polymerization reaction is refluxed, so that the reaction solution contains water. Water in this reaction solution breaks hydrogen bonds between polar groups introduced into the synthesized polyimide compound. Therefore, the apparent molecular weight of the synthesized polyimide compound does not increase, and an increase in viscosity can be prevented, so that the reaction solution does not rise. In addition, in the conventional technique in which nitrogen having a controlled dew point is introduced, water is considered to act near the interface between the reaction solution and humidified nitrogen, whereas in the method of the present invention, water is allowed to act on the entire reaction solution. it can. Therefore, the method for producing a polyimide compound of the present invention is effective when using a monomer having a highly polar substituent, and in particular, when using BSDA, which is difficult to polymerize due to solubility and polarity, as the monomer. This is an extremely effective method.

  In order to improve the mechanical properties of the polyimide compound, it is necessary to increase the degree of polymerization. Conventionally, in order to obtain a polyimide compound having a high degree of polymerization, water generated by polymerization of acid dianhydride and diamine has been completely removed from the system using an azeotropic agent or the like. However, in the present invention, as in the one-step method and the two-step method, water generated by polymerization is left in the reaction solution, and the amount of reflux imidized water is 0.01 wt% with respect to the total weight of the reaction solution. By setting it as the range of 1.1 wt% or less above, it is possible to ensure a high degree of polymerization and a high solid content concentration so as to obtain a film thickness of 10 μm or more when formed into a film.

  As described above, the production method of the present invention is capable of breaking hydrogen bonds between polar groups by refluxing water generated by polymerization, thereby suppressing an increase in the viscosity of the reaction solution, and the reaction solution by the Weisenberg effect. The phenomenon of rising up can be suppressed. Therefore, it is not necessary to add a special equipment or a step of removing salt such as introducing nitrogen with controlled dew point as in the prior art in order to suppress the phenomenon of rising of the reaction solution. Moreover, since the polyimide compound manufactured by this method can secure a high degree of polymerization and a high solid content concentration, it can be applied to electronic materials, and particularly requires a thick film of 10 μm or more. It can also be applied to the field.

  The effectiveness of the method for producing a polyimide compound of the present invention will be described based on experimental results. In this example, an invention method (one-step invention method, two-step invention method) that adjusts the amount of reflux imidized water in the reaction solution by reflux and a comparison method (one-step comparison) that completely removes the generated water from the system. Method, two-step comparison method).

  First, a polyimide compound using BSDA as a diamine having a polar group was examined.

  In Example 1, a polyimide compound was synthesized by the one-step invention method of the present invention. In a 500 ml four-necked separable flask equipped with a reflux tube, 66.620 g (0.049 mol) of siloxane diamine (X22-9409) and 7.890 g (0.028 mol) of BSDA (purity 99.5%) were added. The mixture was completely dissolved in a mixed solvent of 118.000 g of triglyme (TriGL) and 29.500 g of γ-butyrolactone (GBL) under a nitrogen atmosphere. 27.990 g (0.078 mol) of DSDA (purity 99.7%) was added to the solution, and the mixture was held and refluxed for 3 hours while stirring with an agitator at 180 ° C. in an oil bath to synthesize a polyimide compound.

  In Example 2, a polyimide compound was synthesized by the two-step invention method of the present invention. First, as a first polymerization step, 66.620 g (0.049 mol) of X22-9409 was charged into a 500 ml four-necked separable flask equipped with a Dean-Stark-Trap. Under a nitrogen atmosphere, it was completely dissolved in a mixed solvent of 118.000 g of TriGL and 29.500 g of GBL. 27.990 g (0.078 mol) of DSDA (purity 99.7%) was added to the solution, and the mixture was stirred at room temperature for 12 hours, and then an azeotropic agent for recovering water generated by imidization outside the system. 50 ml of toluene is added, and the mixture is maintained and refluxed for 3 hours while stirring with an agitator at 180 ° C. in an oil bath, and the remaining water and toluene are completely removed by dehydration under reduced pressure just before the stirring is completed. An imide oligomer having a product at the end was synthesized. In addition, the polystyrene standard conversion molecular weight by GPC (Gel Permeation Chromatography: gel permeation chromatography) at this time was 3570 as a number average molecular weight. Further, the IR spectrum when the obtained compound was dried at 100 ° C. for 10 minutes was as shown in FIG. 1, and it was confirmed that the terminal was an acid dianhydride.

  Subsequently, as a second polymerization step, 7.890 g (0.028 mmol) of BSDA (purity 99.5%) was dispersed in the reaction solution cooled to room temperature. Then, remove the Dean-Stark trap provided in the four-neck separable flask, attach a reflux tube instead, hold and reflux for 3 hours while stirring with a stirrer at 180 ° C, and polymerize in the reaction solution The polyimide compound was synthesized by leaving the water produced by the above. When the obtained polyimide compound was dried at 100 ° C. for 10 minutes, the IR spectrum was as shown in FIG. 1, and it was confirmed that the reaction to the polyimide was completely completed.

  In Example 3, BSDA was added separately in the first polymerization step and the second polymerization step so that the weight of water in the reaction solution was 0.01 wt% with respect to the total weight of the reaction solution. A polyimide compound was synthesized in the same manner as in the two-step invention method of 2. Specifically, in the first polymerization step, 7.694 g (0.027 mol) of BSDA (purity 99.5%) was added to the mixed solvent of Example 2 in addition to X22-9409, and the second polymerization step Then, 0.196 g (0.001 mol) of BSDA (purity 99.5%) was added to synthesize a polyimide compound.

  In Example 4, a polyimide compound was synthesized in the same manner as the two-step invention method shown in Example 2. In Example 4, the solid content concentration at which the total amount of DSDA, X22-9409, and BSDA added to the mixed solvent of TriGL and GBL indicates the ratio to the total weight of the reaction solution was 45%.

  In Example 5, a polyimide compound was synthesized in the same manner as the two-step invention method shown in Example 2. In Example 5, the same solid content concentration as in Example 4 was used, and a mixed solvent of 90% TriGL and 10% GBL was used as a solvent.

  In Example 6, a polyimide compound was synthesized in the same manner as the two-step invention method shown in Example 2. In Example 6, the same solid content concentration as in Example 4 was used, and a mixed solvent of 95% TriGL and 5% GBL was used as a solvent.

  In Example 7, a polyimide compound was synthesized in the same manner as the two-step invention method shown in Example 2. In Example 7, the same solid content concentration as in Example 4 was used, and TriGL was used alone as a solvent to be used.

  In Comparative Example 1, a polyimide compound was synthesized by a one-step comparative method, which is a one-step manufacturing method in which water generated by the polymerization reaction is not refluxed. In the method of Comparative Example 1, a Dean-Stark trap is attached to a 500 ml four-necked separable flask instead of the reflux tube used in Example 1, and produced by a polymerization reaction using an azeotropic toluene. Water is completely removed from the reaction system. In Comparative Example 1, N-methyl-2-pyrrolidone (NMP) was used alone as a solvent.

  In Comparative Example 2, a polyimide compound was synthesized in the same manner as the one-step comparative method shown in Comparative Example 1. In Comparative Example 2, GBL was used alone as a solvent.

  In Comparative Example 3, a polyimide compound was synthesized in the same manner as the one-step comparative method shown in Comparative Example 1. In Comparative Example 3, TriGL was used alone as a solvent.

  In Comparative Example 4, a polyimide compound was synthesized in the same manner as the one-step comparison method shown in Comparative Example 1. In Comparative Example 3, TriGL was used alone as a solvent, and the solid content concentration was 20%.

  In Comparative Example 5, a polyimide compound was synthesized in the same manner as the one-step comparison method shown in Comparative Example 1. In Comparative Example 5, the same solvent as Comparative Example 4 was used, and the solid content concentration was 10%.

  In Comparative Example 6, a polyimide compound was synthesized by a two-step comparative method, which is a two-step manufacturing method in which water generated by the polymerization reaction is not refluxed. In the method of Comparative Example 6, a Dean-Stark trap was attached to a 500 ml four-necked separable flask instead of the reflux tube used in the second polymerization step of Example 2, and the azeotropic toluene was used. The water produced by the polymerization reaction is completely removed from the reaction system. In Comparative Example 6, DSDA, X22-9409, BSDA, the solvent to be used, and the solid content concentration were the same as those in Comparative Example 4. Then, DSDA and X22-9409 were dissolved in a mixed solvent of GBL and TriGL, and an imide oligomer was synthesized while completely recovering the generated water. Then, BSDA was dispersed in the reaction solution having the synthesized imide oligomer, and the polyimide compound was synthesized while completely recovering the generated water.

  Tables 1 and 2 below show the monomer composition of the polyimide compound using BSDA as a monomer and the results of each evaluation.

  During the polymerization reaction, it was observed whether or not a phenomenon that the reaction solution was lifted occurred. During the polymerization, when the phenomenon of rising of the reaction solution was confirmed on the shaft of the stirrer due to the Weisenberg effect, X was given, and when the phenomenon of the reaction solution rising was not confirmed, ○ was given, and a slight rise was confirmed. In the case of varnish state (rising during polymerization) in Table 1.

  Moreover, the varnish containing the synthesized polyimide compound was dropped on a slide glass and exposed to a temperature of 30 ° C. and a humidity of 70% for 30 minutes to observe whether the varnish absorbed moisture and whitening occurred. After 30 minutes, the case where the varnish was whitened was marked as x, and the case where the varnish was in a transparent state was marked as ◯.

  Furthermore, the varnish containing the synthesized polyimide compound was coated on a 12 μm copper foil, dried at 100 ° C. for 10 minutes, and the state of the formed polyimide film was evaluated. After drying, the polyimide film to be formed has a film thickness of 10 μm or more, smoothness is good, and a film that does not crack even when the copper foil is bent is marked with ○, and the film thickness is 10 μm. The case where the smoothness is poor or the case where a crack is caused by bending the copper foil is marked as x in the polyimide film state column.

  And the number average molecular weight and weight average molecular weight by polystyrene standard conversion were computed by GPC measurement for the synthesized polyimide compound, and it described in Tables 1 and 2.

  Although the rising phenomenon of the reaction solution was slightly confirmed in Example 3, the polymerization reaction was not interrupted. In Examples 1 and 2, and Examples 4 to 7, the phenomenon of rising of the reaction solution was not confirmed. In Examples 1 to 7, the varnish remained transparent in the evaluation of moisture absorption of the varnish. Furthermore, Example 1 thru | or Example 7 have a high number average molecular weight and a weight average molecular weight, the state of a polyimide film has a film thickness of 10 micrometers or more, smoothness is good, and even if it folds copper foil, The formed film did not crack and good results were obtained.

  On the other hand, in Comparative Examples 2 to 4 and Comparative Example 6, the phenomenon of rising of the reaction solution was confirmed. In Comparative Example 1 and Comparative Example 5, the phenomenon of rising of the reaction solution was not confirmed, but in Comparative Example 1, the varnish was whitened, and in Comparative Example 5, it was difficult to control the film thickness after drying, and the thickness was 10 μm. It was difficult to form a smooth film.

  When a polyimide compound is synthesized by a polymerization reaction between an acid dianhydride and a diamine using an aprotic amide solvent such as NMP as in the method shown in Comparative Example 1, the phenomenon of rising of the reaction solution Is not confirmed. However, since the aprotic amide solvent has high hygroscopicity, the varnish is whitened during printing or coating of the varnish having a polyimide compound. Therefore, when a varnish having a polyimide compound is used for printing or coating, an aprotic polar solvent excluding an amide solvent, particularly a lactone solvent such as GBL, an ether solvent such as TriGL, or a mixture thereof. It is preferable to use a solvent.

  From this result, in the manufacturing method of the polyimide compound of this invention, it produces | generates by a polymerization reaction so that the weight of the water in a reaction solution may be 0.01 wt% or more and 1.1 wt% or less with respect to the reaction solution total weight. It was found that when the water was refluxed, the reaction solution was not lifted up. It was also found that this method can ensure a high degree of polymerization and a high solid content concentration such that the polyimide compound has a film thickness of 10 μm or more when formed into a film.

  Next, a polyimide compound using Bis-Ap-Af as a diamine having a polar group was examined. In Example 8 and Comparative Examples 7 to 11 shown below, the composition of each monomer is 101 mol% for DSDA, 66.2 mol% for X22-9409, and 33.8 mol% for Bis-Ap-Af. .

  In Example 8, a polyimide compound was synthesized in the same manner as the two-step invention method shown in Example 2. In Example 8, the solid content concentration was 43%, and TriGL was used alone as a solvent.

  In Comparative Example 7, a polyimide compound was synthesized in the same manner as the one-step comparative method shown in Comparative Example 1.

  In Comparative Example 8, a polyimide compound was synthesized in the same manner as the one-step comparison method shown in Comparative Example 1. In Comparative Example 8, a mixed solvent of 50% TriGL and 50% GBL was used as a solvent.

  In Comparative Example 9, a polyimide compound was synthesized in the same manner as the one-step comparative method shown in Comparative Example 1. In Comparative Example 9, TriGL was used alone as a solvent.

  In Comparative Example 10, a polyimide compound was synthesized in the same manner as the one-step comparison method shown in Comparative Example 1. In Comparative Example 10, the same solvent as in Comparative Example 9 was used, and the solid content concentration was 45%.

  In Comparative Example 11, a polyimide compound was synthesized in the same manner as the one-step comparison method shown in Comparative Example 1. In Comparative Example 10, the same solvent as in Comparative Example 9 was used, and the solid content concentration was 43%.

  The monomer composition of the polyimide compound using Bis-Ap-Af as a monomer and the results of each evaluation are shown in Table 3 below. About each evaluation, it is the same as that of the said Table 1 and Table 2.

  In Example 8, as in the example using BSDA, the phenomenon of rising of the reaction solution was not confirmed. Moreover, in the evaluation of moisture absorption of the varnish, the varnish remained transparent. Furthermore, the number average molecular weight and the weight average molecular weight are both high, the polyimide film has a film thickness of 10 μm or more, good smoothness, and the formed film does not crack even when the copper foil is bent. Good results were obtained.

  On the other hand, in Comparative Examples 8 to 11, the phenomenon of rising of the reaction solution was confirmed. As for Comparative Example 7, the phenomenon of rising of the reaction solution was not confirmed as in Comparative Example 1, but Comparative Example 1 whitened the varnish, and Comparative Example 5 had a film thickness after drying of less than 10 μm. there were.

  From this result, it was found that even when Bis-Ap-Af was used as the diamine having a polar group, the same effect as that obtained when BSDA was used was obtained.

It is a figure which shows the IR spectrum of the acid anhydride terminal oligomer obtained at the 1st polymerization process in Example 2, and the polyimide compound obtained at the 2nd polymerization process.

Claims (6)

A method for producing a polyimide compound synthesized by a polymerization reaction of an acid dianhydride dissolved in a predetermined solvent, a siloxane diamine, and a diamine having a polar group,
The polymerization reaction is
A first polymerization step for recovering water produced by the polymerization reaction;
A second polymerization step of refluxing water produced by the polymerization reaction,
The weight of water generated by the second polymerization step is adjusted by the amount of diamine having a polar group to be reacted in the second polymerization step, and the weight of water in the reaction solution is based on the total weight of the reaction solution. The method for producing a polyimide compound is characterized in that the water produced in the second polymerization step is refluxed into the reaction system so that it falls within a range of 0.01 wt% to 1.1 wt%. 2. The total weight of the acid dianhydride, the siloxane diamine, and the diamine having a polar group is 10 wt% or more and 60 wt% or less based on the total weight of the reaction solution. A method for producing a polyimide compound. The method for producing a polyimide compound according to claim 1 or 2, wherein the solvent is a lactone solvent, an ether solvent or a mixed solvent thereof. The said polar group is a hydroxyl group, The manufacturing method of the polyimide compound of any one of Claim 1 thru | or 3 characterized by the above-mentioned. 5. The weight of the siloxane diamine is 20 wt% or more and 80 wt% or less based on the total weight of the acid dianhydride, the siloxane diamine, and the diamine having a polar group. The manufacturing method of the polyimide compound of any one of these. The weight of the diamine having a polar group is 0.1 wt% or more and 25 wt% or less based on the total weight of the acid dianhydride, the siloxane diamine, and the diamine having the polar group. The method for producing a polyimide compound according to any one of claims 1 to 5.