KR20180009989A - Solubility Polyimide Particle, Method of Producing The Same and Polyimide film Produced The Same - Google Patents

Abstract

The present invention relates to soluble polyimide particles, a production method thereof and a polyimide film produced thereby. The residues such as unreacted materials, catalysts, etc. in the polyimide particles are minimized. The particle size is controlled to 10 m or less so that a problem causing faults of a film as polyimide particles are not dissolved and condensed in a process of dissolving the polyimide particles again and making the same into a film can be prevented.

Description

Soluble polyimide particles, a process for producing the same, and a polyimide film produced therefrom (Solubility Polyimide Particle, Method of Producing the Same and Polyimide film Produced The Same)

The present invention relates to a soluble polyimide particle, a process for producing the same, and a polyimide film produced therefrom.

Generally, polyimide (PI) resin refers to a high heat-resistant resin prepared by preparing a polyamic acid derivative by combining an aromatic dianhydride with an aromatic diamine or an aromatic diisocyanate in solution and then dehydrating it by ring-closure dehydration at a high temperature. (PMDA) or biphenyltetracarboxylic acid dianhydride (BPDA) or the like is used as an aromatic dianhydride component, and examples of the aromatic diamine component include oxydianiline (ODA), p (P-PDA), m-phenylenediamine (m-PDA), methylene dianiline (MDA), and bisaminophenylhexafluoropropane (HFDA).

However, since the polyimide film is colored with brown or yellow owing to its high aromatic ring density, it has a low transmittance in the visible light region and a yellowish color, which lowers the light transmittance, making it difficult to use the polyimide film in fields requiring transparency. Recently, a colorless transparent polyimide film has been developed. In order to improve the coloring property specific to polyimide, transparency is realized by decreasing the high aromatic ring density or minimizing the intramolecular charge transfer complex. In this case, the inherent insolubility characteristic of the conventional polyimide resin is lowered, and the solvent resistance to the organic solvent is low. The polyimide resin is precipitated in a sub-solvent having a low solubility by using the solubility, To remove the unreacted material and the catalyst, and dissolve the polyimide resin in a soluble solvent to obtain a polyimide resin having improved physical properties, thereby obtaining a polyimide film from which extreme impurities have been removed.

However, when the soluble polyimide particles prepared by the reprecipitation method are reused, the size of the precipitated particles is long due to the particle size of several tens of micrometers to several millimeters, and the re-dissolution time is prolonged and coagulated, There is a problem of causing defects on the film. In addition, if the particle size is large, there is a problem that it is impossible to effectively clean the polymerization solvent, unreacted material, catalyst, etc. remaining in the particles.

Japanese Patent Application No. 2008-081718 discloses a method of mixing polyimide particles with a non-solvent which does not cause precipitation and then precipitating the polyimide particles into a secondary solvent. However, since the particle size is in the range of 0.5 to 1 mm, And it is highly likely that the polymerization residues such as polymerization solvents, unreacted monomers and catalyst components are mixed in the particles.

US Patent Application No. 2012-979597 discloses a method of controlling particle shape to 25 μm or less using hydrolysis. However, the polyimide resin is recycled, dissolved in a basic solvent, and then precipitated with an acid solvent to form particles Which is not suitable for use as an optical polyimide film because of the residual problem of the alkali metal used in the basic solution used and the possibility of lowering the molecular weight. Other particle size control methods using a general milling method are highly undesirable as a particle formation method for producing an optical film because of the high possibility of incorporation of foreign matter during milling.

Other general methods for producing particles containing powdery molding polyimide particles or insoluble polyimide are those in which a solution of a soluble polyamic acid is insoluble polyimide and the resulting solution is subjected to direct precipitation It is possible to adjust the particle size within a range of a few nm to a few 탆, but it is not suitable for a method of producing soluble polyimide particles.

Japanese Patent Application No. 2009-188107 discloses a method for producing a nano-order product obtained by emulsifying a polyamic acid precursor at a temperature below a critical temperature by using a micromixer in an insoluble poor solvent, A method for producing polyamic acid particles is disclosed, but a method using a polyamic acid precursor which is poor in storage stability and a residual problem of a polymer surfactant added for emulsification is required to convert polyamic acid particles to polyimide particles again Is required.

Therefore, in a method for producing a polyimide film, particularly a method for producing an optical polyimide film, it is possible to minimize the amount of unreacted materials and catalysts remaining in the soluble polyimide resin, There is a need for a method for producing polyimide particles which do not induce fine particles.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of the above problems, which is an object of the present invention to minimize the residual of unreacted materials and catalysts in the soluble polyimide particles and to render the polyimide particles unfiltered in the process of re- A method for producing the same, and a polyimide film produced from the polyimide film.

In order to solve the above problems, a first preferred embodiment of the present invention is to provide a soluble polyimide particle having a particle size of 10 탆 or less of a copolymerized polyimide including dianhydride and diamine.

The particles of the polyimide are characterized in that they are obtained by re-impregnation from a soluble polyimide in which a soluble polyamic acid prepared by copolymerization including the dianhydride and a diamine is imidized.

And the particle size is 2 to 10 mu m.

The polyimide has a weight average molecular weight of 50,000 to 600,000.

The dianhydride may be at least one selected from the group consisting of 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropanediamine hydride (6FDA), biphenyltetracarboxylic dianhydride (BPDA) Dioxotetrahydrofuran-3-yl) -1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic anhydride (TDA), pyromellitic acid dianhydride (PMDA), benzophenone tetra (BDA), bisdicarboxyphenoxyphenyldiphenylsulfide dianhydride (BDSDA), sulfonyloxyphenyldimethylsilane dianhydride (SiDA), and the like. (SO2DPA), isopropylidene is at least one selected from the group consisting of phenoxy bisphthalic anhydride (6HBDA) and a group thereof.

The diamine may be at least one selected from the group consisting of oxydianiline (ODA), p-phenylenediamine (pPDA), m-phenylenediamine (mPDA), p-methylenediamine (pMDA), m- 133APB), bisaminophenoxybenzene (134APB), bisaminophenoxyphenylhexafluoropropane (4BDAF), bisaminophenylhexafluoropropane (33-6F), bisaminophenylhexafluoropropane (44-6F) , Bisaminophenylsulfone (4DDS), bisaminophenylsulfone (3DDS), bistrifluoromethylbenzidine (TFDB), cyclohexanediamine (13CHD), cyclohexanediamine (14CHD), bisaminophenoxyphenylpropane (6HMDA) (DBA), bisaminophenoxy diphenyl sulfone (DBSDA), bis (4-aminophenyl) fluorene (FDA), bis (4-amino-3-fluorophenyl) fluorene (F-FDA), and a group of these.

The polyimide may be one copolymerized with an aromatic dicarbonyl compound. The aromatic dicarbonyl compound is at least one selected from the group consisting of terephthaloyl chloride (TPC), terephthalic acid (TPA), isophthaloyl dichloride (IPC), 4,4'-benzoyl chloride (BZC) .

A second preferred embodiment of the present invention is a process for producing a polyamic acid solution comprising: (S1) copolymerizing a dianhydride and a diamine to prepare a polyamic acid solution; Imidizing the prepared polyamic acid solution to prepare polyimide (S2); And a step (S3) of adding the prepared polyimide to a solution having an acid value of pH 4 to 5 and then precipitating (S3) the soluble polyimide.

And the aromatic dicarbonyl compound is copolymerized in the step S1.

The imidation process in the step S2 is characterized in that the imidation is carried out by adding an acid anhydride and an imidation catalyst to react them.

The solution having an acid value of pH 4 to 5 in the step S3 is a mixture of an alcohol and an organic acid anhydride.

The alcohol and the organic acid anhydride are mixed in a weight ratio of 99.95 to 95: 0.05 to 5.

The alcohol is at least one selected from the group consisting of methyl alcohol, ethyl alcohol, 1-propyl alcohol, 2-propyl alcohol and mixtures thereof.

The organic acid anhydride is at least one selected from the group consisting of acetic anhydride, propionic anhydride, anhydrous butyric acid, anhydrous caproic acid, isobutyric anhydride, and mixtures thereof.

A third preferred embodiment of the present invention is to provide a polyimide film produced from the polyimide particles produced by the above-mentioned production method.

According to the present invention, the size of the polyimide particles is controlled to 10 탆 or less, thereby minimizing the amount of unreacted materials, catalysts, and polymerization solvents remaining in the polyimide particles and sufficiently removing them. Thus, It is possible to improve the mechanical properties and to shorten the redissolution time in the film process, thereby achieving economical effects.

According to one embodiment of the present invention, it is possible to provide polyimide particles having a particle size of 10 占 퐉 or less of copolymerized polyimide including dianhydride and diamine.

The polyimide particles according to the present invention have a size of 10 탆 or less, preferably 2 to 10 탆, more preferably 5 to 10 탆, which is significantly lower than the soluble polyimide particle size by the conventional reprecipitation method By implementing the size, it is possible to prevent defects on the film due to the agglomeration of the polyimide particles when the polyimide particles are reused by filming, to shorten the redissolution time and to obtain economical effects, By significantly lowering the amount of the polymerization solvent, unreacted material, catalyst, and the like remaining in the particles, it can be effectively removed during the cleaning process.

In particular, the polyimide particles according to the present invention are obtained by re-impregnating a soluble polyimide having a soluble polyamic acid prepared by copolymerization including a dianhydride and a diamine, in a soluble polyimide.

Specifically, the precipitation method for an insoluble polyimide utilizes the fact that a soluble polyamic acid is imidized to form an insoluble polyimide and precipitation occurs in the solution in the soluble polyamic acid. In the re-impregnation method, There is a method in which the polyimide is made into fine particles through an activator or the like and then a polyimide is formed in the state of fine particles and a method in which a solvent in which soluble polyimide dissolved in the dissolved solvent is dissolved is introduced and precipitated. The latter re-precipitation method has a relatively large particle size relative to the particles obtained by the precipitation method of the insoluble polyimide.

In the present invention, unlike the conventional reprecipitation method, in which polyimide particles are obtained by the reprecipitation method, the soluble polyimide resin is directly granulated. Since the particle size is small, coagulation at the time of solvent cleaning and redissolution of the particles can be minimized Effect. Compared with the conventional precipitation method, it is a re-impregnation method which does not form particles in the amic acid state but forms a precipitate as an imide state, minimizes the residual components and remarkably exerts a remarkable effect on the film which is important in optical properties as it is cleaned during precipitation Can be obtained.

The soluble polyimide according to the present invention means a polyimide which is soluble in an organic solvent, which is commonly used in the field of the present invention, with a solids content of 5% or more. Examples of the organic solvent include m-cresol, N-methyl-2-pyrrolidone (NMP), dimethylformamide (DMF), dimethylacetamide (DMAc), dimethylsulfoxide (DMSO) A solvent used in polymerization of a polar polyimide resin having a polarity such as acetate may be used.

Since the general polyimide is insoluble, the polyimide is prepared by preparing a polyamic acid soluble in a polymerization solvent as described above, and using the polyamic acid to prepare a polyimide resin. In this case, the polyimide resin exhibits inherent insolubility characteristics. In the case of the colorless polyimide (CPI), in order to improve the coloring characteristic peculiar to polyimide, the density of a high aromatic ring is decreased or the intramolecular charge transfer complex The transparency is minimized. In this case, insolubility inherent in the conventional polyimide resin is lowered and the solvent resistance to the organic solvent is low. Therefore, a solvent that does not dissolve the polyimide resin is added to the polyimide resin in a state dissolved in the organic solvent, and precipitation can be generated / granulated from a solvent condition of a certain ratio or more. In the present invention, a soluble polyimide imidized with a soluble polyamic acid means this, and insoluble polyimide is difficult to apply the re-impregnation method as described above.

The polyimide particles preferably have a size of 10 탆 or less, preferably 2 to 10 탆, more preferably 5 to 10 탆. When the thickness is less than 2 탆, it is difficult to dehydrate the solvent in the cake containing the precipitated particles, The cleaning of the particles may be insufficient, and there is a problem that it is difficult to collect the particles after drying the cake. If it is more than 10 mu m, the redissolving time of the particles with respect to the soluble solvent takes a long time, so that a large amount of undissolved matter may be generated.

The polyimide preferably has a weight average molecular weight of 50,000 to 600,000, and preferably 200,000 to 300,000. The polyimide according to the present invention has an advantage that the weight average molecular weight is high and the particle size is reduced. When the weight-average molecular weight is less than 50,000, precipitation does not occur in the precipitation step, and remains in the lower alcohol used as a minor solvent. When the weight average molecular weight is more than 600,000, the viscosity at the time of redissolving becomes too high, It is difficult to obtain polyimide particles of uniform size by precipitating before the uniform precipitation occurs because the precipitation occurs early before uniformly mixing in the minor solvent in the redissolving step.

The dianhydride may be at least one selected from the group consisting of 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropanediamine hydride (6FDA), biphenyltetracarboxylic dianhydride (BPDA) Dioxotetrahydrofuran-3-yl) -1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic anhydride (TDA), pyromellitic acid dianhydride (PMDA), benzophenone tetra (BDA), bisdicarboxyphenoxyphenyldiphenylsulfide dianhydride (BDSDA), sulfonyloxyphenyldimethylsilane dianhydride (SiDA), and the like. (SO2DPA), isopropylidene is at least one selected from the group consisting of phenoxy bisphthalic anhydride (6HBDA) and a group thereof.

The diamine may be at least one selected from the group consisting of oxydianiline (ODA), p-phenylenediamine (pPDA), m-phenylenediamine (mPDA), p-methylenediamine (pMDA), m- 133APB), bisaminophenoxybenzene (134APB), bisaminophenoxyphenylhexafluoropropane (4BDAF), bisaminophenylhexafluoropropane (33-6F), bisaminophenylhexafluoropropane (44-6F) , Bisaminophenylsulfone (4DDS), bisaminophenylsulfone (3DDS), bistrifluoromethylbenzidine (TFDB), cyclohexanediamine (13CHD), cyclohexanediamine (14CHD), bisaminophenoxyphenylpropane (6HMDA) (DBA), bisaminophenoxy diphenyl sulfone (DBSDA), bis (4-aminophenyl) fluorene (FDA), bis (4-amino-3-fluorophenyl) fluorene (F-FDA), and a group of these.

In the present invention, in addition to the dianhydride and diamine included in the copolymerization of the polyimide, an aromatic dicarbonyl compound may be copolymerized.

The aromatic dicarbonyl compound is at least one selected from the group consisting of terephthaloyl chloride (TPC), terephthalic acid (TPA), isophthaloyl dichloride (IPC), 4,4'-benzoyl chloride (BZC) will be.

The above-mentioned polyimide particles having a size of 10 탆 or less can be produced according to another embodiment of the present invention.

According to another embodiment of the present invention, there is provided a process for producing a polyamic acid solution, comprising: (S1) copolymerizing a dianhydride and a diamine to prepare a polyamic acid solution; Imidizing the prepared polyamic acid solution to prepare polyimide (S2); And a step (S3) of adding the prepared polyimide to a solution having an acid value of pH 4 to 5 and then precipitating (S3) the soluble polyimide.

First, a polyamic acid solution is prepared by copolymerizing dianhydride and diamine (S1).

The aromatic dicarbonyl compound may be copolymerized in the step S1.

The dianhydride, diamine and aromatic dicarbonyl compound are the same as described above.

The polyamic acid solution can be prepared by polymerization in a nitrogen or argon atmosphere at a reaction temperature of -10 to 80 and a reaction time of 1 to 48 hours at a 1: 1 equivalent ratio of the dianhydride and the diamine described above.

The solvent (polymerization solvent) for the polymerization reaction of the above monomers is not particularly limited as long as it is a solvent dissolving the polyamic acid. As the known reaction solvent, there may be used, for example, m-cresol, N-methyl-2-pyrrolidone (NMP), dimethylformamide (DMF), dimethylacetamide (DMAc), dimethylsulfoxide (DMSO) One or more polar solvents are used. In addition, a low boiling point solution such as tetrahydrofuran (THF), chloroform or a low-absorbency solvent such as? -Butyrolactone may be used. In addition, a low boiling point solution such as tetrahydrofuran (THF), chloroform or a low-absorbency solvent such as? -Butyrolactone may be used.

The content of the solvent for polymerization is preferably 50 to 95% by weight, more preferably 70 to 90% by weight, based on the total amount of the polyamic acid solution to obtain the appropriate molecular weight and viscosity of the polyamic acid solution, % Is more preferable.

When the aromatic dicarbonyl compound is copolymerized in step S1, the molar amount of the dianhydride and the aromatic dicarbonyl compound and the molar amount of the diamine are preferably in an equimolar amount, and they are dissolved in the solvent and polymerized A polyamic acid solution can be prepared. The conditions for the polymerization reaction are not particularly limited, but the reaction temperature is preferably -20 to 80, and the reaction time is preferably 2 to 48 hours. It is more preferable that the reaction atmosphere is an inert atmosphere such as argon or nitrogen.

Next, the prepared polyamic acid solution is imidized to prepare polyimide (S2).

By using the dianhydride, the aromatic dicarbonyl compound and the diamine, the polyimide of the present invention can obtain the effect of improving the heat resistance if it is colorless and transparent.

The polyimide resin prepared by imidizing the polyamic acid solution thus prepared preferably has a glass transition temperature (Tg) of 200 to 400 in consideration of thermal stability.

As the imidation method that can be applied to the step of imidizing the polymerized polyamic acid, a chemical imidation method can be mentioned.

In the chemical imidation method, a dehydrating agent represented by an acid anhydride such as acetic anhydride and a imidation catalyst represented by tertiary amines such as isoquinoline, β-picoline, and pyridine are added to the polyamic acid solution.

In the present invention, it is preferable that imidization is carried out by a chemical imidization method in which an acid anhydride and an imidization catalyst are added and reacted in the imidation method described above. The chemical imidation method implements the polyamic acid and precipitates in a minor solvent having low solubility such as water and alcohol, so that precipitated particles can be obtained in a stable soluble polyimide state in which hydrolysis by a minor solvent does not occur Lt; / RTI >

Then, the prepared polyimide is added to a solution having an acid value of pH 4 to 5 and then precipitated (S3).

That is, the polyimide prepared in the step S2 is added to a solution of a lower alcohol having an acid value of pH 4 to 5, preferably an acid value of 4 to 4.5, and then the solution is precipitated. The polyimide particles having the following sizes can be produced.

The alcohol may be at least one selected from the group consisting of lower alcohols such as methyl alcohol, ethyl alcohol, 1-propyl alcohol and 2-propyl alcohol, and mixtures thereof. The ease of drying and the solubility of polyimide Methyl alcohol or ethyl alcohol is most preferable in terms of relatively high molecular weight oligomers and the like in order to remove them without precipitating.

The organic acid anhydride may be at least one selected from the group consisting of acetic anhydride, anhydrous propionic acid, anhydrous butyric acid, anhydrous caproic acid, anhydrous isobutyric acid, and a mixture thereof. The dehydrating agent used in the above- The use of the same organic acid anhydride is preferable to anhydrous acetic acid known to have high imidization rate and good sedimentation property in view of not impairing the stability of the polyimide. .

It is preferable that the alcohol and the organic acid anhydride are mixed in a weight ratio of 99.95 to 95: 0.05 to 5, preferably 99.9 to 98: 0.1 to 2. If the organic acid anhydride is out of the above range, the degree of imidization of the polyimide resin during the precipitation may be partially uneven depending on the organic acid anhydride added, so that the particle size distribution of the precipitated polyimide particles is widened, .

In the present invention, it is possible to obtain polyimide particles in the form of solid powder having a size of 10 탆 or less through a process of precipitating the polyimide in a solution of a lower alcohol containing acid-anhydride-adjusted organic acid anhydride having a pH of 4 to 5 .

When the polyimide is added to a solution having an acid value of less than 4, there is a problem that the polyimide resin gels in a state in which the polyimide resin is mixed without causing precipitation in the secondary solvent. Further, when a small amount of organic acid anhydride is used so as to have an acid value exceeding pH 5, the effect of obtaining uniform particles of 10 탆 or less when precipitated in a minor solvent of polyimide resin is low, Lt; / RTI >

When the organic acid anhydride is an anhydrous organic acid, the acid having an acid value of less than 4 appears at a small mixing amount, so that the solution does not precipitate and gels There is a problem of discarding and an anhydrous form is preferable. Therefore, it is preferable to use an organic acid anhydride which is easy to control the acid value, and in view of the stability of the polyimide, the acetic anhydride which is the same as the dehydrating agent used in the above-mentioned chemical imidation process is most preferable.

The polyimide particles can basically be used as a film, a varnish, an adhesive, a molding material, a toner, or the like in substitution for metal / ceramics. However, the particles of the soluble polyimide using the reprecipitation according to the present invention, .

According to another embodiment of the present invention, there can be provided a polyimide film produced from the polyimide particles produced by the above-mentioned production method.

The polyimide particles may be used to produce a film by selecting one of the polyimide film production methods well known in the art to which the present invention belongs. For example, the polyimide particles may be used in combination with m-cresol, Used for the polymerization of polar polyamides in polar solvents such as N-methyl-2-pyrrolidone (NMP), dimethylformamide (DMF), dimethylacetamide (DMAc), dimethylsulfoxide (DMSO), acetone and diethyl acetate , The solution obtained is applied to a stainless steel plate, casted and dried with hot air, and then slowly cooled to separate from the plate to obtain a polyimide film.

Hereinafter, the present invention will be described in more detail with reference to Examples. These examples are for the purpose of illustrating the present invention more specifically, and the present invention is not limited thereto.

Example  One

Nitrogen was passed through a 1 L reactor equipped with a stirrer, a nitrogen injector, a dropping funnel, a temperature controller and a condenser, and 910.08 g of N, N-dimethylacetamide (DMAc) was charged. 57.64 g (0.18 mol) of TFDB was dissolved and the solution was maintained at 25 占 폚. 26.48g (0.09mol) of BPDA and 39.98g (0.09mol) of 6FDA were added thereto, followed by stirring and dissolving for a predetermined time. 17.09 g of pyridine and 21.86 g of anhydrous acetic acid were added to the polymerized polyamic acid solution, and the mixture was stirred for 30 minutes and further stirred at 80 ° C for 1 hour and cooled to room temperature. The polyimide resin was added to the mixture of 1551.28 g of methanol and 7.75 g of acetic anhydride at pH 4.3 to precipitate the precipitate. The precipitate was filtered with 20 L of methanol and then dried at 100 ° C under vacuum for 6 hours to obtain a poly I got a Mid. The weight average molecular weight of the polyimide was 1.9 x 10 ⁵ g / mol.

Example  2

Nitrogen was passed through a 1 L reactor equipped with a stirrer, a nitrogen injector, a dropping funnel, a temperature controller and a condenser, and 910.08 g of N, N-dimethylacetamide (DMAc) was charged. 57.64 g (0.18 mol) of TFDB was dissolved and the solution was maintained at 25 占 폚. 26.48g (0.09mol) of BPDA and 39.98g (0.09mol) of 6FDA were added thereto, followed by stirring and dissolving for a predetermined time. 17.09 g of pyridine and 21.86 g of anhydrous acetic acid were added to the polymerized polyamic acid solution, and the mixture was stirred for 30 minutes and further stirred at 80 ° C for 1 hour and cooled to room temperature. The polyimide resin was added to the mixed solution of 1551.28 g of methanol and 16.35 g of anhydrous acetic acid to precipitate the precipitate. The precipitate was filtered with 20 L of methanol and then dried at 100 DEG C under vacuum for 6 hours to obtain a poly I got a Mid. The weight average molecular weight of the polyimide was 1.9 x 10 ⁵ g / mol.

Example  3

Nitrogen was passed through a 1 L reactor equipped with a stirrer, a nitrogen injector, a dropping funnel, a temperature controller and a condenser, and 910.08 g of N, N-dimethylacetamide (DMAc) was charged. 57.64 g (0.18 mol) of TFDB was dissolved and the solution was maintained at 25 占 폚. 26.48g (0.09mol) of BPDA and 39.98g (0.09mol) of 6FDA were added thereto, followed by stirring and dissolving for a predetermined time. 17.09 g of pyridine and 21.86 g of anhydrous acetic acid were added to the polymerized polyamic acid solution, and the mixture was stirred for 30 minutes and further stirred at 80 ° C for 1 hour and cooled to room temperature. The polyimide resin was introduced into a mixed solution of 1551.28 g of 2-propyl alcohol and 7.75 g of acetic anhydride to precipitate the polyimide resin. The precipitate was filtered with 20 L of methanol and then dried under vacuum at 100 DEG C for 6 hours to obtain a solid powder Lt; / RTI > polyimide was obtained. The weight average molecular weight of the polyimide was 1.9 x 10 ⁵ g / mol.

Example  4

Nitrogen was passed through a 1 L reactor equipped with a stirrer, a nitrogen injector, a dropping funnel, a temperature controller and a condenser, and 910.08 g of N, N-dimethylacetamide (DMAc) was charged. 57.64 g (0.18 mol) of TFDB was dissolved and the solution was maintained at 25 占 폚. 26.48g (0.09mol) of BPDA and 39.98g (0.09mol) of 6FDA were added thereto, followed by stirring and dissolving for a predetermined time. 17.09 g of pyridine and 21.86 g of anhydrous acetic acid were added to the polymerized polyamic acid solution, and the mixture was stirred for 30 minutes and further stirred at 80 ° C for 1 hour and cooled to room temperature. The polyimide resin was added to the mixed solution of 1551.28 g of methanol and 7.75 g of anhydrous propionic acid to deposit the polyimide resin. The precipitate was filtered with 20 L of methanol, and then dried at 100 ° C under vacuum for 6 hours to obtain a poly I got a Mid. The weight average molecular weight of the polyimide was 1.9 x 10 ⁵ g / mol.

Example  5

N, N-dimethylacetamide (DMAc) 889.99 g was charged into a 1 L reactor equipped with a stirrer, a nitrogen injector, a dropping funnel, a temperature controller and a condenser, and the temperature of the reactor was adjusted to 25 ° C 57.64 g (0.18 mol) of TFDB was dissolved and the solution was maintained at 25 占 폚. 15.89g (0.054mol) of BPDA, 7.85g (0.036mol) of PMDA and 39.98g (0.09mol) of 6FDA were added and dissolved and reacted for a certain period of time. 17.09 g of pyridine and 21.86 g of anhydrous acetic acid were added to the polymerized polyamic acid solution, and the mixture was stirred for 30 minutes and further stirred at 80 ° C for 1 hour and cooled to room temperature. The polyimide resin was added to the mixture of 1551.28 g of methanol and 7.75 g of acetic anhydride at pH 4.3 to precipitate the precipitate. The precipitate was filtered with 20 L of methanol and then dried at 100 ° C under vacuum for 6 hours to obtain a poly I got a Mid. The weight average molecular weight of the polyimide was 3.3 x 10 < ⁵ > g / mol.

Example  6

N, N-dimethylacetamide (DMAc) 761 g was charged into a 1 L reactor equipped with a stirrer, a nitrogen injector, a dropping funnel, a temperature controller and a condenser while nitrogen was passed through the reactor. 57.64g (0.18mol) was dissolved and the solution was maintained at 25 占 폚. 14.30 g (0.049 mol) of BPDA and 9.60 g (0.022 mol) of 6FDA were added thereto, and the mixture was stirred and dissolved for a predetermined time. After maintaining the temperature of the solution at 15 ° C, 22.29g (0.109mol) of TPC was added, and the solution was reacted at 25 ° C for 12 hours to obtain a polyamic acid solution. 17.09 g of pyridine and 21.86 g of anhydrous acetic acid were added to the polymerized polyamic acid solution, and the mixture was stirred for 30 minutes and further stirred at 80 ° C for 1 hour and cooled to room temperature. The polyimide resin was added to the mixture of 1551.28 g of methanol and 7.75 g of acetic anhydride at pH 4.3 to precipitate the precipitate. The precipitate was filtered with 20 L of methanol and then dried at 100 ° C under vacuum for 6 hours to obtain a poly I got a Mid. The polyimide had a weight average molecular weight of 2.1 x 10 < ⁵ > g / mol.

Comparative Example  One

Nitrogen was passed through a 1 L reactor equipped with a stirrer, a nitrogen injector, a dropping funnel, a temperature controller and a condenser, and 910.08 g of N, N-dimethylacetamide (DMAc) was charged. 57.64 g (0.18 mol) of TFDB was dissolved and the solution was maintained at 25 占 폚. 26.48g (0.09mol) of BPDA and 39.98g (0.09mol) of 6FDA were added thereto, followed by stirring and dissolving for a predetermined time. To the polymerized polyamic acid solution, 17.09 g of pyridine and 21.86 g of anhydrous acetic acid were added. After stirring for 30 minutes, the mixture was further stirred at 80 ° C for 1 hour to be imidized, and then cooled to room temperature. The prepared polyimide was added to 1551.28 g of methanol to precipitate. The precipitated solids were filtered and dried at 100 DEG C under vacuum for 6 hours to obtain polyimide in a solid powder state. The weight average molecular weight of the polyimide was 1.9 x 10 ⁵ g / mol.

Comparative Example  2

Nitrogen was passed through a 1 L reactor equipped with a stirrer, a nitrogen injector, a dropping funnel, a temperature controller and a condenser, and 910.08 g of N, N-dimethylacetamide (DMAc) was charged. 57.64 g (0.18 mol) of TFDB was dissolved and the solution was maintained at 25 占 폚. 26.48g (0.09mol) of BPDA and 39.98g (0.09mol) of 6FDA were added thereto, followed by stirring and dissolving for a predetermined time. To the polymerized polyamic acid solution, 17.09 g of pyridine and 29.61 g of acetic anhydride were added. After stirring for 30 minutes, the mixture was stirred at 80 ° C for 1 hour to imidize the mixture, and then cooled to room temperature to prepare polyimide. The polyimide was added to 1551.28 g of methanol to precipitate the precipitate. The precipitate was filtered with 20 L of methanol and then dried at 100 DEG C under vacuum for 6 hours to obtain polyimide in a solid powder state. The weight average molecular weight of the polyimide was 1.9 x 10 ⁵ g / mol.

Comparative Example  3

Nitrogen was passed through a 1 L reactor equipped with a stirrer, a nitrogen injector, a dropping funnel, a temperature controller and a condenser, and 910.08 g of N, N-dimethylacetamide (DMAc) was charged. 57.64 g (0.18 mol) of TFDB was dissolved and the solution was maintained at 25 占 폚. 26.48g (0.09mol) of BPDA and 39.98g (0.09mol) of 6FDA were added thereto, followed by stirring and dissolving for a predetermined time. To the polymerized polyamic acid solution, 17.09 g of pyridine and 21.86 g of acetic anhydride were added. After stirring for 30 minutes, the mixture was stirred at 80 ° C for 1 hour to imidize the mixture, and then cooled to room temperature to prepare polyimide. The polyimide thus prepared was added to a mixture of 1551.28 g of methanol and 81.55 g of acetic anhydride to precipitate the precipitated polyimide. The precipitate was filtered with 20 L of methanol and then dried under vacuum at 100 ° C. for 6 hours to obtain a solid Polyimide was obtained. The weight average molecular weight of the polyimide was 1.9 x 10 ⁵ g / mol.

Comparative Example  4

Nitrogen was passed through a 1 L reactor equipped with a stirrer, a nitrogen injector, a dropping funnel, a temperature controller and a condenser, and 910.08 g of N, N-dimethylacetamide (DMAc) was charged. 57.64 g (0.18 mol) of TFDB was dissolved and the solution was maintained at 25 占 폚. 26.48g (0.09mol) of BPDA and 39.98g (0.09mol) of 6FDA were added thereto, followed by stirring and dissolving for a predetermined time. To the polymerized polyamic acid solution, 44.84 g of pyridine and 55.129 g of acetic anhydride were added. After stirring for 30 minutes, the mixture was stirred at 80 ° C for 1 hour to imidize the mixture, and then cooled to room temperature to prepare polyimide. The polyimide was added to the mixture of 1551.28 g of methanol and 0.62 g of acetic acid to precipitate the precipitate. The precipitate was filtered with 20 L of methanol, and then dried under vacuum at 100 캜 for 6 hours to obtain a solid agglomerated polyimide . The weight average molecular weight of the polyimide was 1.9 x 10 ⁵ g / mol.

Film manufacturing

The polyimide particles prepared according to Examples 1 to 6 and Comparative Examples 1 to 4 were dissolved in N, N-dimethylacetamide (DMAc) to obtain a solution having a solid content of 11 wt%, and the thus obtained solution was applied to a stainless steel plate And then the film was dried by hot air at 150 ° C for 1 hour, at 200 ° C for 1 hour, and at 300 ° C for 30 minutes by hot air, then slowly cooled and separated from the plate to obtain an 80 μm polyimide film. Thereafter, the substrate was subjected to heat treatment at 300 ° C for 10 minutes as a final heat treatment process.

How to measure

The polyimide particles and films prepared according to Examples 1 to 6 and Comparative Examples 1 to 4 were measured for their physical properties by the following methods. The measured physical properties are shown in Table 1 below.

 (1) Average particle size and coefficient of variation (C.V .: Coefficient of variation)

The coefficient of variation (CV) was measured using a particle size distribution analyzer (Multisizer 3, manufactured by Coulter Electronics Co., Ltd.) with respect to the average particle diameter representing the polyimide particles produced. The coefficient of variation (CV) Respectively.

[Equation 1]

C.V. (%) = (standard deviation of particle diameter / average particle diameter of particle) 占 100

(2) Reuse time

The polyimide particles thus prepared were dissolved in DMAc of 25 캜 at a concentration of 5% as a solid, and then sieved with a sieve having a sieve size of 25 탆 to determine the presence or absence of gel-state undissolved components by the respective dissolution time. At this time, the minimum dissolution time at which the gelatinous unsalted powder was not visually confirmed by the sieve was measured.

(3) Weight average molecular weight The polystyrene reduced weight average molecular weight (Mw) was determined by gel permeation chromatography (GPC) (Sykam GPC System [pump: S1122, RI Dectector: S3580] The polymer to be measured was dissolved in dimethylacetamide so as to have a concentration of 10,000 ppm and 20 μl was injected into GPC. The mobile phase of GPC was run at a flow rate of 1.0 mL / min using a solvent in which 25 mM LiBr and 30 mM H3PO4 were dissolved in a tetrahydrofuran and dimethylformamide 1: 1 solvent, and the analysis was carried out at 50 ° C. The column was connected in series with two Agilent PLgel Mixed-D. The detector was measured at 50 캜 using RI.

(4) Optical transmittance

The prepared film was measured for optical transmittance at 550 nm using a UV spectrometer (Kotikaminolta CM-3700d).

(5) Yellow Index (Y.I.)

The yellowing degree was measured according to the ASTM E313 standard using a UV spectrometer (Kotikaminolta CM-3700d).

division Average particle diameter (占 퐉) C.V. (%) Redeposition time (hr) Optical Transmittance (%) Yellowing degree Example 1 8 14 3  88.6 3.7 Example 2 5 19 4  88.6 3.7 Example 3 9 15 3 88.5 3.9 Example 4 10 15 3 88.1 4.0 Example 5 9 14 3 87.8 4.9 Example 6 5 18 4 88.5 4.2 Comparative Example 1 31 27 More than 24 hours 87.2 5.4 Comparative Example 2 30 27 More than 24 hours 87.1 5.4 Comparative Example 3 Agglomeration during gelation / precipitation - - - - Comparative Example 4 Agglomeration during gelation / precipitation - - - -

As shown in Table 1, the polyimide particles of Examples 1 to 6 produced according to the present invention had an average particle diameter of 10 μm or less and a variation coefficient of 14% to 19% And the time is excellent. However, in Comparative Examples 1 and 2, since the average particle diameter was 24 탆 or more, which is a level of the prior art, and the dispersion degree was high, the possibility of secondary aggregation of precipitated particles at the time of redissolution was high, There is a problem. Further, in Comparative Examples 3 to 4, it can be seen that the sediment does not occur in the gelled state when the minor solvent is added.

The polyimide particles of Examples 1 to 6 produced according to the present invention had an average particle diameter of 10 μm or less and a variation coefficient of 14% to 19%, and the polyimide film produced using the polyimide particles had a yellowing degree of 5 or less It is colorless and transparent, and the redissolution time is short, so that it can be seen that there is an advantage that the optical film can be efficiently produced with excellent optical properties. However, in Comparative Examples 1 to 4, the average particle diameter of the polyimide particles after the precipitation was 24 탆 or more, which is the level of the prior art, so that the unreacted materials remained in the particles during the polymerization to lower the optical properties, It can be seen that there is a problem that takes a long time to remove the minute.

Claims (16)

Soluble polyimide particles having a particle size of 10 占 퐉 or less of copolymerized polyimide including dianhydride and diamine.
The soluble polyimide particle according to claim 1, wherein the particles of the polyimide are obtained by re-impregnating a soluble polyimide prepared by copolymerization including the dianhydride and the diamine, from a soluble polyimide imidized.
The soluble polyimide particle according to claim 1, wherein the particle size is from 2 to 10 mu m.
The soluble polyimide particles according to claim 1, wherein the polyimide has a weight average molecular weight of 50,000 to 600,000.
The method of claim 1, wherein the dianhydride is selected from the group consisting of 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropanediamine hydrate (6FDA), biphenyltetracarboxylic dianhydride (BPDA), 4 - (2,5-dioxotetrahydrofuran-3-yl) -1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic anhydride (TDA), pyromellitic acid dianhydride (PMDA), benzophenone tetracarboxylic dianhydride (BTDA), oxydiphthalic dianhydride (ODPA), biscarboxyphenyldimethylsilanediamine hydride (SiDA), bisdicarboxyphenoxy diphenylsulfide dianhydride (BDSDA), sulfonyldiphthalic anhydride (SO2DPA), isopropylidene is at least one selected from the group consisting of phenoxy bisphthalic anhydride (6HBDA) and a group thereof.
The method of claim 1, wherein the diamine is selected from the group consisting of oxadiazines (ODA), p-phenylenediamine (pPDA), m-phenylenediamine (mPDA), p- methylenediamine (pMDA) , Bisaminophenoxybenzene (133APB), bisaminophenoxybenzene (134APB), bisaminophenoxyphenylhexafluoropropane (4BDAF), bisaminophenylhexafluoropropane (33-6F), bisaminophenylhexafluoro (14CHD), cyclohexanediamine (14CHD), bisaminophenoxane (14CHD), bis-aminophenylsulfone (14DD), bis (4-aminophenyl) fluorene (FDA), bis (4-aminophenyl) fluorene, bis (aminophenyl) 3-fluorophenyl) fluorene (F-FDA) and one or more of these groups Loja is soluble polyimide particles.
The soluble polyimide particles according to claim 1, wherein the polyimide is copolymerized with an aromatic dicarbonyl compound.
8. The method of claim 7, wherein the aromatic dicarbonyl compound is selected from the group consisting of terephthaloyl chloride (TPC), terephthalic acid (TPA), isophthaloyl dichloride (IPC), 4,4'-benzoyl chloride (BZC) Soluble polyimide particles. ≪ RTI ID = 0.0 > 11. < / RTI >
(S1) copolymerizing the dianhydride and the diamine to prepare a polyamic acid solution;
Imidizing the prepared polyamic acid solution to prepare polyimide (S2); And
(S3) adding the polyimide to a solution having an acid value of pH 4 to 5 and then precipitating the polyimide.
The process for producing soluble polyimide particles according to claim 9, wherein the step (S1) comprises copolymerizing an aromatic dicarbonyl compound.
10. The method according to claim 9, wherein in the step (S2), the imidation step is carried out by a chemical imidization method in which an acid anhydride and an imidization catalyst are added and reacted.
10. The method according to claim 9, wherein the solution having an acid value of 4 to 5 in step S3 comprises a mixture of an alcohol and an organic acid anhydride.
13. The method according to claim 12, wherein the alcohol and the organic acid anhydride are mixed in a weight ratio of 99.95 to 95: 0.05 to 5.
13. The process for producing soluble polyimide particles according to claim 12, wherein the alcohol is at least one selected from the group consisting of methyl alcohol, ethyl alcohol, 1-propyl alcohol, 2-propyl alcohol and mixtures thereof.
13. The method according to claim 12, wherein the organic acid anhydride is at least one selected from the group consisting of acetic anhydride, propionic anhydride, anhydrous butyric acid, anhydrous caproic acid, isobutyric acid anhydride, .
16. A polyimide film produced from the polyimide particles produced according to any one of claims 9 to 15.