KR20210121009A - Novel diamines, novel polyimides derived therefrom, and molded articles thereof - Google Patents

Abstract

A diamine compound for providing a resin having both excellent solvent solubility (solution processability) and high heat resistance, a polyimide having excellent solution processability synthesized from the diamine compound, and a molded article having high heat resistance obtained from the polyimide do it with By the diamine compound represented by the following formula (1), the above problem can be solved.
[Formula 1]

Description

Novel diamines, novel polyimides derived therefrom, and molded articles thereof

The present invention relates to a novel polyimide derived from diamine, which is excellent in processability and has high heat resistance, and to a polyimide molded product thereof. Since the polyimide of the present invention has high heat resistance in addition to excellent solution processability, insulating materials used in electronic devices such as flexible wiring boards and semiconductors, and liquid crystal displays (LCD) and organic electroluminescent (EL) displays It is also useful as a plastic substrate used for , electronic paper, light emitting diode (LED) devices, solar cells, and the like.

BACKGROUND ART Polyimides that can withstand a high temperature higher than the solder mounting temperature (260° C.) are widely used as insulating materials for semiconductor devices and flexible printed wiring boards. However, most polyimides with high heat resistance lack processability, and in most cases, they are processed from a polyimide precursor (for example, polyamic acid soluble in a solvent) (Non-Patent Document 1).

In order to form (imidize) a polyimide from a polyimide precursor, since high temperature (thermal imidation) of 300 degreeC or more is required, a use may be limited by the imidation temperature. In addition, in the case of producing a polyimide molded body from a polyimide precursor, depending on the thermal imidization conditions, defects (voids) in the molded body may be caused by rupture due to shrinkage accompanying dehydration and ring closure, and desorption components generated during imidization. There is also a possibility of generating it, and it is very difficult to control the imidation reaction. Furthermore, there existed a fault that the high temperature furnace required for imidation of 300 degreeC or more was needed, and manufacturing cost also became high.

Accordingly, a polyimide soluble in a solvent (solvent-soluble polyimide) in a state in which imidization has already been completed has been developed in recent years, and processability has been improved compared to that of the conventional polyimide. Most of these polyimides introduce a bond that facilitates intramolecular rotational motion by bending a polymer main chain such as a siloxane chain or an ether bond in the polyimide main chain, or put a bulky substituent in the side chain to prevent aggregation of the polymer chain The workability is improved by inhibiting or reducing the concentration of imide groups in the main chain (Non-Patent Documents 2 and 3). However, this molecular design significantly lowers the heat resistance inherent to polyimide. Therefore, it was difficult to synthesize|combine the polyimide which had heat resistance of 300 degreeC or more and high solvent solubility.

Prog. Polym. Sci., 16, 561 (1991). Polym. Eng. Sci., 29, 1413 (1989). J. Polym. Sci., Part A, Polym. Chem., 44, 6836 (2006).

The present invention relates to a diamine compound for providing a resin having both excellent solvent solubility (solution processability) and high heat resistance, a polyimide having excellent solution processability synthesized from the diamine compound, and a molded article having high heat resistance obtained from the polyimide. intended to provide

As a result of intensive research to solve the above problems, the present inventors have found that a polyimide having excellent solution processability is obtained from the diamine compound represented by the following formula (1), and the polyimide has heat resistance of 300° C. or higher, and the present invention completed

The present invention is as follows.

1. A diamine compound represented by Formula 1 below.

(In the formula, R ₁ , R ₂ is a trifluoromethyl group, R ₃ , R ₄ each independently represents an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a, b, c, and d are Each independently represents an integer of 0 to 4. However, the sum of a and c and the sum of b and d are each 4 or less.)

2. A diamine compound represented by Formula 2 below.

(In the formula, R ₅ , R ₆ each independently represents a hydrogen atom or a trifluoromethyl group.)

3. A polyimide comprising a structural unit represented by the following formula (3).

(In the formula, R ₁ , R ₂ is a trifluoromethyl group, R ₃ , R ₄ each independently represents an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a, b, c, and d are Each independently represents an integer of 0 to 4, and X represents a tetravalent aromatic and/or aliphatic group, provided that the sum of a and c and the sum of b and d are each 4 or less.)

4. A polyimide comprising a structural unit represented by the following formula (4).

(In the formula, R ₅ and R ₆ each independently represent a hydrogen atom or a trifluoromethyl group, and X represents a tetravalent aromatic and/or aliphatic group.)

5. The polyimide solution which consists of the polyimide of 3. or 4. and a solvent.

6. A polyimide molded article obtained from the polyimide solution described in 5.

According to the present invention, a diamine compound characterized in that six methyl groups are substituted in a central biphenylene group in a polyimide having excellent solution processability and high heat resistance, and a molded product thereof, which were difficult in the prior art. It is obtained by setting it as a raw material.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the infrared spectrum of the polyimide film of Example 2. FIG.
2 is a view showing an infrared spectrum of the polyimide film of Example 3. FIG.
3 is a view showing an infrared spectrum of the polyimide film of Example 4.
4 is a view showing an infrared spectrum of the polyimide film of Example 6.

The diamine compound of the present invention has a chemical structure represented by Chemical Formula 1 below.

[Formula 1]

(In the formula, R ₁ , R ₂ is a trifluoromethyl group, R ₃ , R ₄ each independently represents an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a, b, c, and d are Each independently represents an integer of 0 to 4. However, the sum of a and c and the sum of b and d are each 4 or less.)

In formula (1), a and b are each independently preferably 0, 1, or 2, more preferably 0 or 1, and still more preferably 1. Among them, it is preferable that a and b are a combination of 0 and 1, or both are 1. In this case, _{the (trifluoromethyl group) substitution position of R 1} and R ₂ is ortho-position or meta-position with respect to the ether bond. A position is preferable, and an ortho position is more preferable.

In the formula (1), _{when any one of R 3} and R ₄ is an alkyl group having 1 to 4 carbon atoms, it means a linear or branched alkyl group having 1 to 4 carbon atoms, specifically, a methyl group, an ethyl group, n -propyl group, i-propyl group, n-butyl group, i-butyl group, and t-butyl group are mentioned. Among them, an alkyl group having 1 or 2 carbon atoms is preferable. When _{any one of R 3} and R ₄ is an alkoxy group having 1 to 4 carbon atoms, it means a linear or branched alkoxy group having 1 to 4 carbon atoms, specifically, a methoxy group, an ethoxy group, n-propoxy period, i-propoxy group, n-butoxy group, i-butoxy group, and t-butoxy group. Among them, an alkoxy group having 1 or 2 carbon atoms is preferable. In the formula (1), _{preferred embodiments of R 3} and R ₄ are a methyl group, an ethyl group, and a methoxy group, and among these, a methyl group is more preferable. c and d are each independently preferably 0, 1, or 2, more preferably 0 or 1, and still more preferably 0.

In the general formula (1), the substitution position of the amino group is preferably meta-position or para-position with respect to the ether bond, and more preferably para-position.

Among the diamine compounds represented by the general formula (1), the diamine compounds represented by the following general formula (2) are preferable.

[Formula 2]

(In the formula, R ₅ , R ₆ each independently represents a hydrogen atom or a trifluoromethyl group.)

In the general formula (2), the substitution position of the amino group is preferably a meta position or a para position with respect to the ether bond, and more preferably a para position. Further, _{when either or both of R 5} and R ₆ are a trifluoromethyl group, the substituted position is preferably an ortho position or a meta position with respect to an ether bond, and more preferably an ortho position.

The chemical structural characteristics of the polyimide using the diamine compound represented by Formula 1 is that 6 methyl groups exist at the 2,2',3,3',5,5' positions of the central biphenylin group through an ether bond. will do These methyl groups greatly distort the dihedral angle of the biphenylene group by a steric hindrance effect (non-coplanarity), thereby preventing aggregation between polymer chains, thereby improving solubility in solvents. In addition, since the steric hindrance effect also suppresses intramolecular rotation around the ether bond, the heat resistance of the polyimide containing this structure, that is, the glass transition temperature, is increased. Among them, in the general formula (2), when a trifluoromethyl group is introduced into only one or both of _{R 5} and R _{6 , it particularly contributes to the same steric effect.}

Hereinafter, the present invention will be described in detail.

The polyimide of the present invention is prepared using a diamine compound represented by the following formula (1).

[Formula 1]

<Method for producing diamine compound>

The diamine compound represented by the formula (1) is a diol (5), that is, 2,2',3,3',5,5'-hexamethyl-biphenyl-4,4'-diol, as shown by the following reaction formula (Hereinafter referred to as HM44BP in some cases.) can

(In the above scheme, R ₁ to _{R 4} , a to d have the same definitions as in Formula 1, and Y represents a halogen atom.)

Suitable examples of the halogenated nitrobenzenes represented by the formulas (6) and (7), specifically, 4-chloronitrobenzene, 4-fluoronitrobenzene, and 2-chloro-5-nitrobenzotrifluoro Ride, 2-fluoro-5-nitrobenzotrifluoride, 1-chloro-3-nitrobenzene, 3-fluoronitrobenzene, 5-chloro-2-nitrobenzotrifluoride, 5-fluoro-2- Nitrobenzotrifluoride, 2-chloro-5-nitrotoluene, 2-fluoro-5-nitrotoluene, 2,5-dimethyl-4-chloronitrobenzene, 2,5-dimethyl-4-fluoronitrobenzene, 2-chloro-5-nitroanisole, 2-fluoro-5-nitroanisole, 2,3-dimethyl-4-chloronitrobenzene, 2,3-dimethyl-4-fluoronitrobenzene, etc. are mentioned. . The halogenated nitrobenzenes represented by the formula (6) and the halogenated nitrobenzenes represented by the formula (7) may be the same.

Moreover, as a diamine compound synthesize|combined from the said suitable halogenated nitrobenzenes, the thing of the following chemical structure is mentioned specifically,.

A characteristic of the chemical structure of the diamine compound represented by Formula 1, which is the raw material of the polyimide of the present invention, is that six methyl substituents exist in the central biphenylene group, thereby increasing (twisting) the dihedral angle of the biphenyl. . Thereby, the solubility with respect to a solvent and heat resistance can be improved.

The polyimide of the present invention can synthesize a polyimide including a structural unit represented by the following Chemical Formula 3 by using the diamine compound represented by Chemical Formula 1 as a raw material and reacting it with an acid dianhydride, and has excellent properties as described above. polyimide can be obtained.

[Formula 3]

(In the formula, R ₁ , R ₂ is a trifluoromethyl group, R ₃ , R ₄ each independently represents an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a, b, c, and d are Each independently represents an integer of 0 to 4, and X represents a tetravalent aromatic and/or aliphatic group, provided that the sum of a and c and the sum of b and d are each 4 or less.)

In the polyimide containing the structural unit represented by the formula (3) _{, a suitable chemical structure for R 1} to _{R 4} or its substitution positions and a to d, which is the number of substituents, and the substitution position of a nitrogen atom derived from an amino group is represented by the formula (1) It is the same as the diamine compound shown.

Among the polyimides of the present invention, in particular, the polyimide containing the structural unit represented by the general formula (4) exhibits an excellent effect of improving solubility in solvents and heat resistance.

[Formula 4]

(In the formula, R ₅ and R ₆ each independently represent a hydrogen atom or a trifluoromethyl group, and X represents a tetravalent aromatic and/or aliphatic group.)

In the polyimide containing the structural unit represented by the formula (4) _{, a suitable chemical structure for R 5} , R ₆ or its substitution position and the substitution position of a nitrogen atom derived from an amino group is the same as that of the diamine compound represented by the formula (2) do.

Although it does not specifically limit about the manufacturing method of a polyimide, An acid dianhydride, for example, an aromatic and/or aliphatic tetracarboxylic dianhydride, and the diamine containing the diamine compound of this invention react so that the substance amount of it becomes equimolar. Thus, it can be produced through a process of obtaining a polyimide precursor (polyamic acid) represented by the following Chemical Formula 8 and a process of imidizing the polyimide precursor.

(In the formula, R ₁ to _{R 4} and a to d have the same definitions as in Formula 1.)

Although it does not specifically limit as aromatic and/or aliphatic tetracarboxylic dianhydride which can be used when superposing|polymerizing the polyimide precursor of this invention, As aromatic tetracarboxylic dianhydride, For example, pyromellitic dianhydride, 3 ,3',4,4'-biphenyltetracarboxylic dianhydride, hydroquinone-bis(trimellitate anhydride), methylhydroquinone-bis(trimellitate anhydride), 1,4,5 ,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 3,3' ,4,4'-biphenylethertetracarboxylic dianhydride, 3,3',4,4'-biphenylsulfonetetracarboxylic dianhydride, 2,2'-bis(3,4-dicarboxyphenyl) ) hexafluoropropanoic acid dianhydride, 2,2'-bis(3,4-dicarboxyphenyl)propanoic acid dianhydride, etc. are mentioned.

As an aliphatic tetracarboxylic dianhydride, for example, as an alicyclic one, bicyclo[2. 2. 2] octo-7-ene-2,3,5,6-tetracarboxylic dianhydride, 5-(dioxotetrahydrofuryl-3-methyl-3-cyclohexene-1,2-dicarboxyl Acid anhydride, 4-(2,5-dioxotetrahydrofuran-3-yl)tetralin-1,2-dicarboxylic acid anhydride, tetrahydrofuran-2,3,4,5-tetracarboxylic acid dianhydride, bicyclo-3,3',4,4'-tetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentane Tetracarboxylic dianhydride etc. are mentioned.

As these acid dianhydrides, it is also possible to use together 2 or more types.

Examples of the acid dianhydride used to obtain the polyimide of the present invention include tetracarboxylic dianhydride having a rigid and linear structure from the viewpoint of heat resistance of the polyimide molded article, that is, pyromellitic dianhydride, 3,3' ,4,4'-biphenyltetracarboxylic dianhydride is suitable.

When polymerizing the precursor of the polyimide of the present invention, an aromatic or aliphatic diamine compound may be used in combination as a copolymerization component in addition to the diamine compound represented by the above formula (1) in the range that does not significantly impair polymerization reactivity and properties of the polyimide molded body. have.

Examples of the aromatic diamine usable at this time include 2,2'-bis(trifluoromethyl)benzidine, p-phenylenediamine, m-phenylenediamine, 2,4-diaminotoluene, 2,5-diaminotoluene, 2,4-diaminoxylene, 2,4-diaminodurene, 4,4'-diaminodiphenylmethane, 4,4'-methylenebis(2-methylaniline), 4,4'-methylenebis(2 -ethylaniline), 4,4'-methylenebis(2,6-dimethylaniline), 4,4'-methylenebis(2,6-diethylaniline), 4,4'-diaminodiphenyl ether, 3 ,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 2,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylsulfone, 3,3'-diamino Diphenylsulfone, 4,4'-diaminobenzophenone, 3,3'-diaminobenzophenone, 4,4'-diaminobenzanilide, 4-aminophenyl-4'-aminobenzoate, benzidine, 3, 3'-dihydroxybenzidine, 3,3'-dimethoxybenzidine, o-tolidine, m-tolidine, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-amino) Phenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, bis(4-(3-aminophenoxy)phenyl)sulfone, Bis(4-(4-aminophenoxy)phenyl)sulfone, 2,2-bis(4-(4-aminophenoxy)phenyl)propane, 2,2-bis(4-(4-aminophenoxy)phenyl ) Hexafluoropropane, 2,2-bis(4-aminophenyl)hexafluoropropane, p-terphenylenediamine, etc. are mentioned.

The aliphatic diamine is a chain aliphatic or alicyclic diamine, and the alicyclic diamine is, for example, 4,4'-methylenebis(cyclohexylamine), isophoronediamine, and trans-1,4-diaminocyclo. Hexane, cis-1,4-diaminocyclohexane, 1,4-cyclohexanebis(methylamine), 2,5-bis(aminomethyl)bicyclo[2. 2. 1] Heptane, 2,6-bis (aminomethyl) bicyclo [2. 2. 1] Heptane, 3,8-bis (aminomethyl) tricyclo [5. 2. 1. 0] Decane, 1,3-diaminoadamantane, 2,2-bis(4-aminocyclohexyl)propane, 2,2-bis(4-aminocyclohexyl)hexafluoropropane, chain Examples of the aliphatic diamine include 1,3-propanediamine, 1,4-tetramethylenediamine, 1,5-pentamethylenediamine, 1,6-hexamethylenediamine, 1,7-heptamethylenediamine, 1,8 -octamethylenediamine, 1,9- nonamethylenediamine, diaminosiloxane, etc. are mentioned.

One or more types of these diamine compounds can be used in combination.

Among them, diamine compounds having a rigid and linear structure, that is, 2,2'-bis(trifluoromethyl)benzidine (hereinafter, TFMB is sometimes called.) is suitable as a copolymerization component.

The solvent used for polymerization of the polyimide precursor is preferably an aprotic solvent such as N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, or dimethyl sulfoxide, When the raw material monomer, the produced polyimide precursor, and the imidized polyimide are dissolved, any solvent can be used without any problem, and the structure or type of the solvent is not particularly limited. Specifically, for example, an amide solvent such as N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, γ-butyrolactone, γ-valerolactone, ester solvents such as δ-valerolactone, γ-caprolactone, ε-caprolactone, α-methyl-γ-butyrolactone, butyl acetate, ethyl acetate, isobutyl acetate, carbonate solvents such as ethylene carbonate and propylene carbonate; glycol solvents such as diethylene glycol dimethyl ether, triethylene glycol and triethylene glycol dimethyl ether, phenolic solvents such as phenol, m-cresol, p-cresol, o-cresol, 3-chlorophenol, and 4-chlorophenol; Ketone solvents such as cyclopentanone, cyclohexanone, acetone, methyl ethyl ketone, diisobutyl ketone, and methyl isobutyl ketone, tetrahydrofuran, 1,4-dioxane, dimethoxyethane, diethoxyethane, dibutyl Ether solvents, such as ether, are mentioned. Other general-purpose solvents include acetophenone, 1,3-dimethyl-2-imidazolidinone, sulfolane, dimethyl sulfoxide, propylene glycol methyl acetate, ethyl cellosolve, butyl cellosolve, 2-methyl cellosolve acetate , ethyl cellosolve acetate, butyl cellosolve acetate, butanol, ethanol, xylene, toluene, chlorobenzene, turpentine, mineral spirit, petroleum naphtha solvent and the like can also be used. You may use these solvents in mixture of 2 or more types.

The method for manufacturing the polyimide of this invention is not specifically limited, A well-known method is applicable suitably. Specifically, for example, it can be synthesized by the following method.

First, a diamine compound is dissolved in a polymerization solvent, and a powder of tetracarboxylic dianhydride substantially equimolar to the diamine compound is gradually added to the solution, and a mechanical stirrer or the like is used in the range of 0 to 100°C, preferably Stirring is carried out at 20-60 degreeC for 0.5-150 hours, Preferably it is 1-72 hours. At this time, the monomer concentration is usually in the range of 5 to 50% by weight, preferably in the range of 10 to 40% by weight. By performing polymerization in such a monomer concentration range, a polyimide precursor having a uniform and high polymerization degree can be obtained. When the polymerization degree of a polyimide precursor increases too much and the polymerization solution becomes difficult to stir, it is also possible to dilute suitably with the same solvent. From the viewpoint of increasing the mechanical strength of the polyimide molded body, the polymerization degree of the polyimide precursor is preferably as high as possible. By carrying out the polymerization in the above monomer concentration range, the polymerization degree of the polymer is sufficiently high, and the solubility of the monomer and the polymer can be sufficiently ensured. When polymerization is performed at a concentration lower than the above range, the polymerization degree of the polyimide precursor may not be sufficiently high, and if polymerization is performed at a concentration higher than the above monomer concentration range, the monomer or the resulting polymer may not be sufficiently dissolved. . In addition, in the case of using an aliphatic diamine, salt formation often occurs at the beginning of polymerization to hinder polymerization. desirable.

The imidation method of the obtained polyimide precursor is demonstrated.

A well-known imidation method can be applied for imidation, For example, "thermal imidation method" which thermally cyclizes a polyimide precursor film, and "solution thermal imide" which cyclizes a polyimide precursor solution at high temperature. Chemical imidization method", "chemical imidation method" using a dehydrating agent, etc. can be used suitably.

Specifically, in the case of "thermal imidization method", a polyimide precursor solution (for example, polyamic acid) is cast on a substrate or the like, and dried at 50 to 200°C, preferably 60 to 150°C. After forming the polyimide precursor film, by heating in an inert gas or under reduced pressure at 150°C to 400°C, preferably 200°C to 380°C for 1 to 12 hours, thermal dehydration cyclization is performed to complete imidization, thereby completing imidization of the polyimide of the present invention. A molded body can be obtained.

In addition, in the case of the "solution thermal imidization method", a polyimide precursor (for example, polyamic acid) solution to which a basic catalyst or the like has been added is heated in the presence of an azeotrope such as xylene at 100 to 250°C, preferably at 150 to 220°C. The polyimide solution of the present invention can be obtained by heating in a furnace for 0.5 to 12 hours to remove byproduct water from the system to complete imidization.

In the case of "chemical imidation method", while stirring the polyimide precursor solution prepared by adjusting the polyimide precursor (for example, polyamic acid) to a suitable solution viscosity that is easy to stir with a mechanical stirrer or the like, an anhydride of an organic acid and a basic catalyst Imidization is chemically completed by adding dropwise a dehydrating ring-closing agent (chemical imidizing agent) composed of amines and stirring at 0 to 100°C, preferably 10 to 50°C for 1 to 72 hours. Although it does not specifically limit as an organic acid anhydride which can be used at this time, Acetic anhydride, propionic anhydride, etc. are mentioned. Acetic anhydride is preferably used from the viewpoint of handling and purification of reagents. Moreover, as a basic catalyst, pyridine, triethyleneamine, quinoline, etc. can be used, Although pyridine is used suitably from handling of a reagent and the ease of isolation|separation, It is not limited to these. The amount of organic acid anhydride in the chemical imidizing agent is in the range of 1 to 10 moles of the theoretical dehydration amount of the polyimide precursor (when using polyamic acid), more preferably 1 to 5 moles. The amount of the basic catalyst is in the range of 0.1 to 2 moles, more preferably 0.1 to 1 mole, based on the amount of the organic acid anhydride.

In the case of "solution thermal imidization method" or "chemical imidization method", since by-products (hereinafter referred to as impurities) such as catalysts, chemical imidization agents, and carboxylic acids are mixed in the reaction solution, these are removed and You may refine it. For purification, a known method can be used. For example, as the simplest method, the imidized reaction solution is added dropwise to a large amount of poor solvent while stirring to precipitate polyimide, then the polyimide powder is recovered, washed repeatedly until impurities are removed, and dried under reduced pressure. Thus, a method for obtaining polyimide powder can be applied. At this time, as a solvent that can be used, alcohols such as water, methanol, ethanol, and isopropanol, which precipitate polyimide, can remove impurities efficiently and are easy to dry, are suitable, and these may be mixed and used. When the concentration of the polyimide solution is added dropwise to the poor solvent to precipitate, if the concentration of the polyimide solution is too high, the precipitated polyimide becomes a particle agglomeration, and impurities may remain in the coarse particles. It may take a long time to dissolve in On the other hand, when the density|concentration of a polyimide solution is made too thin, since a large amount of poor solvent is required and the environmental load increase accompanying waste-solvent treatment and manufacturing cost become high, it is unpreferable. Therefore, the density|concentration of the polyimide solution at the time of dripping in a poor solvent is 20 weight% or less, More preferably, it is 10 weight% or less. The amount of the poor solvent used at this time is preferably equal to or greater than that of the polyimide solution, preferably 1.5 to 3 times the amount.

The obtained polyimide powder is collect|recovered, and a residual solvent is removed by vacuum drying, hot air drying, etc. The drying temperature and time are not limited as long as the polyimide is not deteriorated and the residual solvent is not decomposed, and drying is preferably performed in a temperature range of 30 to 200°C for 48 hours or less.

The polyimide of the present invention has an intrinsic viscosity of the polyimide, preferably in the range of 0.1 to 10.0 dL/g, more preferably in the range of 0.5 to 5.0 dL/g.

Since the polyimide of the present invention is soluble in various solvents, a solvent can be selected according to the intended use or processing conditions. For example, although not particularly limited, amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone; γ-butyrolactone, γ-valerolactone Ester solvents such as , δ-valerolactone, γ-caprolactone, ε-caprolactone, α-methyl-γ-butyrolactone, carbonate solvents such as ethylene carbonate and propylene carbonate, diethylene glycol dimethyl ether, triethylene glycol , glycol solvents such as triethylene glycol dimethyl ether, phenolic solvents such as phenol, m-cresol, p-cresol, o-cresol, 3-chlorophenol, and 4-chlorophenol, cyclopentanone, cyclohexanone, and acetone , ketone solvents such as methyl ethyl ketone, diisobutyl ketone, methyl isobutyl ketone, ether solvents such as tetrahydrofuran, 1,4-dioxane, dimethoxyethane, diethoxyethane, dibutyl ether, and other general purpose As the solvent, acetophenone, 1,3-dimethyl-2-imidazolidinone, sulfolane, dimethyl sulfoxide, butyl acetate, ethyl acetate, isobutyl acetate, propylene glycol methyl acetate, ethyl cellosolve, butyl cellosolve , 2-methyl cellosolve acetate, ethyl cellosolve acetate, butyl cellosolve acetate, chloroform, butanol, ethanol, xylene, toluene, chlorobenzene, turpentine, mineral spirits, petroleum naphtha solvents and the like can also be used. You may mix and use 2 or more types of these solvents.

The solid content concentration when the polyimide of the present invention is dissolved in a solvent to form a solution varies depending on the molecular weight of the polyimide, the manufacturing method, and the molded article to be manufactured, but preferably 5 wt% or more. When the solid content concentration is too low, molding to a sufficient film thickness becomes difficult, and conversely, when the solid content concentration is high, the solution viscosity is too high and molding becomes difficult. As a method for dissolving the polyimide of the present invention in a solvent, for example, the polyimide powder of the present invention is added while stirring the solvent, and 1 in the temperature range from room temperature to the boiling point of the solvent or less in air or in an inert gas. It can be made to melt|dissolve over time - 48 hours, and it can be set as a polyimide solution.

Moreover, additives, such as a mold release agent, a filler, a silane coupling agent, a crosslinking agent, a terminal blocker, antioxidant, an antifoamer, and a leveling agent, can be added to the polyimide of this invention as needed.

The obtained polyimide solution can be shape|molded by a well-known method. For example, in the case of forming a polyimide film, the polyimide solution is cast on a support such as a glass substrate using a doctor blade or the like, and a hot air dryer, an infrared dryer, a vacuum dryer, an inert oven, etc. , It can be set as a polyimide film by drying normally in the range of 40-300 degreeC, Preferably it is 50-250 degreeC.

Since the polyimide molded article of the present invention molded as described above has a glass transition temperature of 300° C. or higher, it is particularly suitably used as a heat-resistant material, for example, lead-free soldering when used in semiconductors or flexible wiring boards. Since it can sufficiently withstand the mounting temperature of 260°C, it is suitable as an insulating material.

Example

Hereinafter, the present invention will be specifically described by way of Examples, but the present invention is not limited to these Examples. In addition, the physical property value in the following example was measured by the following evaluation method.

<About evaluation method>

1. Infrared absorption spectrum

The infrared absorption spectrum of the diamine compound was measured by the KBr method using Fourier transform infrared spectrophotometer FT/IR4100 (made by the Japan Spectroscopy company). In addition, about the infrared absorption spectrum of polyimide, the thin film sample (about 5 micrometers thickness) was produced and measured.

2. ¹ H-NMR spectrum

Using Fourier transform nuclear magnetic resonance JNM-ECP400 (manufactured by JEOL), ¹ H-NMR spectrum of the polyimide powder synthesized and chemically imidized in _{deuterated dimethyl sulfoxide (DMSO) or deuterated chloroform (CDCl 3 ) was measured} did.

3. Differential Scanning Calorimetry (melting point)

The melting point of the diamine compound was measured using a differential scanning calorimeter DSC3100 (manufactured by Nechi Corporation) in a nitrogen atmosphere at a temperature increase rate of 2°C/min. The higher the melting point and the sharper the melting peak, the higher the purity.

4. Intrinsic Viscosity

The reduced viscosity of 0.5 wt % of the polyimide precursor solution or polyimide solution was measured at 30° C. using an Ostwald viscometer. As the solvent, N-methyl-2-pyrrolidone (NMP) was used. This value was regarded as the intrinsic viscosity.

5. Solubility test of polyimide powder in solvent

With respect to 0.1 g of the polyimide powder, 9.9 g (solid content concentration of 1 wt%) of the solvent described in Table 2 was put into a sample tube, and the dissolved state was visually confirmed by stirring for 5 minutes using a test tube mixer.

As a solvent, N,N-dimethylacetamide (DMAc), N-methyl-2-pyrrolidone (NMP), dimethyl sulfoxide (DMSO), γ-butyrolactone (GBL), triethylene glycol dimethyl ether (Tri- GL) was used.

In Table 2, the evaluation results are ++ when dissolved at room temperature, + when dissolved by heating and uniformity was maintained even after cooling to room temperature, ± when swollen/partially dissolved, and - when insoluble. indicated.

6. Glass transition temperature: Tg

The glass transition temperature of the polyimide film was determined using a thermomechanical analyzer (TMA4000) manufactured by Nechi Corporation, with a polyimide film size of 5 mm in width, 15 mm in length, and a load of 5° C./min. After raising the temperature to 150 ° C with a furnace (first temperature increase), cooling to 20 ° C, and further raising the temperature at 5 ° C / min (second temperature increase), the tangential method of the TMA curve at the second temperature rise (the tangent to the glassy state and It was calculated|required from the intersection of the tangent line after Tg).

7. Average coefficient of linear thermal expansion: CTE

The coefficient of linear thermal expansion of the polyimide film was measured using TMA4000 manufactured by Nechi Corporation (sample size: width 5 mm, length 15 mm), the load was set to a film thickness (µm) × 0.5 g, and the temperature was raised to 150°C once at 5°C/min. After (1st temperature rise), it cooled to 20 degreeC, it further heated up at 5 degreeC/min (2nd time temperature rise), and it calculated from the TMA curve at the time of 2nd temperature rise. The linear thermal expansion coefficient was calculated|required as an average value between 100-200 degreeC.

8. Pyrolysis temperature (nitrogen), pyrolysis temperature (air)

Using a thermogravimetric analyzer (TG-DTA2000) manufactured by Nechi Co., Ltd., the initial weight of the polyimide film (20 µm thickness) was reduced by 5% in the process of increasing the temperature in nitrogen or in air at a temperature increase rate of 10°C/min. The temperature at the time was measured. It shows that thermal stability is so high that these values are high.

9. Average refractive index: n _av

Using an Abbe refractometer (Abe 1T) manufactured by Atago Co., _{Ltd., the refractive indices of the direction parallel to the polyimide film plane (n in} ) and the direction perpendicular to the plane of the polyimide film (film thickness direction) (n _out ) were measured with an Abbe refractometer (using a sodium lamp, wavelength 589). nm).

From this refractive index, the average refractive index (n _av =(2n _in + n _out )/3) of the polyimide film was computed.

10. Permittivity: ε _opt

Based on the average refractive index n _av of the polyimide film, the dielectric constant (ε _opt =1.1×n _av ² ) of the polyimide film was calculated.

11. Modulus of elasticity, maximum elongation at break

Using TENSILON UTM-2 (manufactured by A&D), a tensile test (stretching speed: 8 mm/min) was performed on a polyimide film test piece (3 mm × 30 mm), and the stress-strain curve was The elastic modulus (GPa) was obtained from the initial gradient, and the maximum elongation at break (%) was obtained from the elongation at the time of breakage of the film. The higher the maximum elongation at break, the higher the toughness of the film.

Example 1

Synthesis of diamine compound represented by Formula 1 of the present invention

Synthesis of dinitrosomal intermediates

In a 100 mL three-necked flask, 6.93 g (30.7 mmol) of 2-chloro-5-nitrobenzotrifluoride, HM44BP (2,2',3,3',5,5'-hexamethyl-biphenyl-4,4) 2.71 g (10.0 mmol) of '-diol), 2.89 g of potassium carbonate, and 20 mL of N,N-dimethylformamide (DMF) were added, and the mixture was stirred at 85°C under a nitrogen atmosphere for 2.5 hours. A precipitate was formed during the reaction. The reaction solution was poured into a large amount of water, and the precipitate was recovered. The precipitate was washed with methanol and then dried at 100°C in a vacuum dryer for 12 hours (amount 5.60 g, yield 86%). The dried crude product was recrystallized from dimethyl sulfoxide to obtain a white powder (total yield 83%).

Identification of dinitrosomal intermediates

The product was obtained from a Fourier transform infrared spectrophotometer FT/IR4100 (manufactured by Japan Spectroscopy) ^{, an aromatic C-H stretching vibration absorption band at 3103 cm -1} , an aliphatic C-H stretching vibration absorption band at 2951 cm ^-1 , 1524, 1357 cm ^-1 A nitro group stretching vibration absorption band, and an ether C-O-C stretching vibration absorption band at ^{1252, 1193 cm -1 were confirmed.}

^{As a result of performing 1} H-NMR measurement using a Fourier transform nuclear magnetic resonance spectrophotometer JNM-ECP400 (manufactured by JEOL) _{, (CDCl 3} -d ₁ , δ, ppm): 8.63 (sd, J = 2.6 Hz, 2H), 8.32-8.28 (m, 2H), 6.98 (s, 1H), 6.92 (sd, J = 3.3 Hz, 1H), 6.70-6.64 (m, 2H), and 2.11-1.99 (m, 18H).

From the above analysis result, it was confirmed that the product was a dinitro body.

Moreover, when melting|fusing point was measured with differential scanning calorimetry DSC3100 (Nechi Corporation), the sharp melting peak was shown at 297 degreeC, and it was suggested that this product is high purity.

Synthesis of diamine compounds (reduction of dinitro intermediates)

In a 200 mL three-necked flask, add 5.13 g (7.91 mmol) of dinitro body, 0.514 g of palladium/carbon (Pd 10%) (about 55% wetted product) as catalyst, 120 mL of DMF, and 120 °C while bubbling hydrogen. was stirred for 5 hours. Then, after standing to cool to room temperature, the catalyst was separated by filtration, the filtrate was poured into saturated brine, and the precipitate was collect|recovered. The precipitate was washed with water, xylene, and methanol, and dried in a vacuum dryer at 120° C. for 12 hours (amount 4.34 g, yield 93%). 1.57 g of the obtained crude product was dissolved by heating with toluene (90 mL) and ethyl acetate (20 mL), and the recrystallized product was collected by filtration. The recovered crystals were washed with toluene and methanol, and then dried in a vacuum dryer at 120° C. for 12 hours to obtain a white powder (total yield: 80%).

Identification of diamine compounds

The product was obtained from a Fourier transform infrared spectrophotometer FT/IR4100 (manufactured by Japan Spectroscopy Co., Ltd.) at 3449, 3346 cm ⁻¹ in N-H stretching vibration absorption band, 3011 cm ⁻¹ in aromatic C-H stretching vibration absorption band, 2919 cm ⁻¹ in Aliphatic C-H stretching vibration absorption band, 1348, 1047 cm ^{-1 The} ether C-O-C stretching vibration absorption band was confirmed.

^{As a result of performing 1} H-NMR measurement using a Fourier transform nuclear magnetic resonance spectrophotometer JNM-ECP400 (manufactured by JEOL) _{, (CDCl 3-} d ₁ , δ, ppm): 7.00 (sd, J=4.0 Hz, 2H), 6.89(s, 1H), 6.84(sd, J=4.0 Hz, 1H), 6.65-6.67(m, 2H), 6.28-6.34(m, 2H), 3.55(s, 4H), 1.93-2.17(m, 18H).

The elemental analysis values were estimated values C: 65.30%, H: 5.14%, N: 4.76%, measured values C: 65.06%, H: 5.16%, and N: 4.66%.

From these analysis results, it was confirmed that the product was a diamine compound.

Example 2

Polyimide precursor polymerization; PMDA (50): s-BPDA (50) / diamine compound 25 mol%

0.4414 g (0.75 mmol) of the diamine compound synthesized in Example 1 and 0.7205 g (2.25 mmol) of 2,2'-bis(trifluoromethyl)benzidine (TFMB) were dehydrated N-methyl-2-pyrrolidone ( NMP). Here, 0.3272 g (1.50 mmol) of pyromellitic dianhydride (PMDA) powder and 0.4413 g (1.50 mmol) of 3,3',4,4'-biphenyltetracarboxylic dianhydride (s-BPDA) powder were mixed. One powder was slowly added and stirred at room temperature for 72 hours to obtain polyamic acid as a polyimide precursor (solid content concentration: 19.2 wt%). The obtained polyamic acid had an intrinsic viscosity of 1.29 dL/g.

chemical imidization reaction

After diluting the obtained polyamic acid solution with dehydration NMP to a solid content concentration of 10.0% by weight, a mixed solution of 3.0627 g (30 mmol) acetic anhydride and 1.1865 g (15 mmol) pyridine was slowly added dropwise at room temperature while stirring, After completion, the mixture was stirred for an additional 24 hours. The obtained polyimide solution was slowly dripped at a large amount of ethanol, and the polyimide was precipitated. The resulting precipitate was sufficiently washed with ethanol and vacuum dried at 120°C for 12 hours. As a result of proton NMR measurement of this powder, COOH protons (near δ13 ppm) and NHCO protons (near δ11 ppm) specific to polyamic acid were not observed, suggesting that the chemical imidization reaction was complete. . The intrinsic viscosity of the obtained polyimide was 2.95 dL/g, and it was a high molecular weight body.

Preparation of polyimide solution and film forming of polyimide film

The polyimide powder was redissolved in NMP at room temperature to prepare an 8.49 wt% homogeneous solution. This polyimide solution was cast on a glass substrate and dried at 80°C with a hot air dryer for 2 hours. Thereafter, the substrate was dried at 250° C. in vacuum for 1 hour, allowed to cool to room temperature, and then the polyimide film was peeled from the glass substrate. This polyimide film was heat-treated once more at 255° C. in vacuum to remove residual strain.

Example 3

Polyimide precursor polymerization; PMDA(50): s-BPDA(50)/diamine compound 50 mol%

0.8829 g (1.50 mmol) of the diamine compound synthesized in Example 1 and 0.4803 g (1.50 mmol) of 2,2'-bis(trifluoromethyl)benzidine (TFMB) were dissolved in dehydrated NMP. Here, 0.3272 g (1.50 mmol) of pyromellitic dianhydride (PMDA) powder and 0.4413 g (1.50 mmol) of 3,3',4,4'-biphenyltetracarboxylic dianhydride (s-BPDA) powder were added. The mixed powder was slowly added and stirred at room temperature for 72 hours to obtain polyamic acid as a polyimide precursor (solid content concentration of 19.9% by weight). The obtained polyamic acid had an intrinsic viscosity of 0.91 dL/g.

chemical imidization reaction

After diluting the obtained polyamic acid solution with dehydrated NMP to a solid content concentration of 10.0% by weight, a mixed solution of 3.0627 g (30 mmol) acetic anhydride and 1.1865 g (15 mmol) pyridine was slowly added dropwise at room temperature while stirring, After completion of the dropwise addition, the mixture was stirred for an additional 24 hours. The obtained polyimide solution was slowly dripped at a large amount of ethanol, and the polyimide was precipitated. The resulting precipitate was sufficiently washed with ethanol and vacuum dried at 120°C for 12 hours. As a result of proton NMR measurement of this powder, COOH protons (near δ13 ppm) and NHCO protons (near δ11 ppm) specific to polyamic acid were not observed, suggesting that the chemical imidization reaction was complete. . The intrinsic viscosity of the obtained polyimide was 1.57 dL/g, and it was a high molecular weight body.

Preparation of polyimide solution and film forming of polyimide film

The polyimide powder was redissolved in NMP at room temperature to prepare a 15.8 wt% homogeneous solution. This polyimide solution was cast on a glass substrate and dried at 80°C with a hot air dryer for 2 hours. Thereafter, the substrate was dried at 250° C. in vacuum for 1 hour, allowed to cool to room temperature, and then the polyimide film was peeled from the glass substrate. This polyimide film was heat-treated once more at 250° C. in vacuum to remove residual strain.

Example 4

Polyimide precursor polymerization; PMDA (50): s-BPDA (50) / diamine compound 75 mol%

1.3243 g (2.25 mmol) of the diamine compound synthesized in Example 1 and 0.2402 g (0.75 mmol) of 2,2'-bis(trifluoromethyl)benzidine (TFMB) were dissolved in dehydrated NMP. Here, 0.3272 g (1.50 mmol) of pyromellitic dianhydride (PMDA) powder and 0.4413 g (1.50 mmol) of 3,3',4,4'-biphenyltetracarboxylic dianhydride (s-BPDA) powder were mixed. One powder was slowly added and stirred at room temperature for 72 hours to obtain polyamic acid as a polyimide precursor (solid content concentration: 18.4 wt%). The obtained polyamic acid had an intrinsic viscosity of 0.46 dL/g.

chemical imidization reaction

After diluting the obtained polyamic acid solution with dehydration NMP to a solid content concentration of 10.0% by weight, a mixed solution of 3.0627 g (30 mmol) acetic anhydride and 1.1865 g (15 mmol) pyridine was slowly added dropwise at room temperature while stirring, After completion, the mixture was stirred for an additional 24 hours.

The obtained polyimide solution was slowly dripped at a large amount of ethanol, and the polyimide was precipitated. The resulting precipitate was sufficiently washed with ethanol and vacuum dried at 120°C for 12 hours. As a result of proton NMR measurement of this powder, COOH protons (near δ13 ppm) and NHCO protons (near δ11 ppm) specific to polyamic acid were not observed, suggesting that the chemical imidization reaction was complete. . The intrinsic viscosity of the obtained polyimide was 1.15 dL/g, and it was a high molecular weight body.

Preparation of polyimide solution and film forming of polyimide film

The polyimide powder was redissolved in NMP at room temperature to prepare a 23.4 wt% homogeneous solution. This polyimide solution was cast on a glass substrate and dried at 80°C with a hot air dryer for 2 hours. Thereafter, the substrate was dried at 250° C. in vacuum for 1 hour, allowed to cool to room temperature, and then the polyimide film was peeled from the glass substrate. This polyimide film was heat-treated once more at 305° C. in vacuum to remove residual strain.

Example 5

Preparation of polyimide solution and film forming of polyimide film

The polyimide powder of Example 4 was redissolved in γ-butyrolactone (GBL) at room temperature to prepare a 16.5 wt% homogeneous solution. This polyimide solution was cast on a glass substrate and dried at 80°C with a hot air dryer for 2 hours. Thereafter, the substrate was dried at 250° C. in vacuum for 1 hour, allowed to cool to room temperature, and then the polyimide film was peeled from the glass substrate. This polyimide film was heat-treated once more at 325°C in vacuum to remove residual strain.

Example 6

Polyimide precursor polymerization; PMDA(50): s-BPDA(50)/diamine compound 100 mol%

1.7657 g (3.00 mmol) of the diamine compound synthesized in Example 1 was dissolved in dehydrated NMP. Here, 0.3272 g (1.50 mmol) of pyromellitic dianhydride (PMDA) powder and 0.4413 g (1.50 mmol) of 3,3',4,4'-biphenyltetracarboxylic dianhydride (s-BPDA) powder were mixed. One powder was slowly added, followed by stirring at room temperature for 72 hours to obtain polyamic acid as a polyimide precursor (solid content concentration: 16.9 wt%). The obtained polyamic acid had an intrinsic viscosity of 0.66 dL/g.

chemical imidization reaction

After diluting the obtained polyamic acid solution with dehydration NMP to a solid content concentration of 10.0% by weight, a mixed solution of 3.0627 g (30 mmol) acetic anhydride and 1.1865 g (15 mmol) pyridine was slowly added dropwise at room temperature while stirring, After completion, the mixture was stirred for an additional 24 hours. The obtained polyimide solution was slowly dripped at a large amount of ethanol, and the polyimide was precipitated. The resulting precipitate was sufficiently washed with ethanol and vacuum dried at 120°C for 12 hours. As a result of proton NMR measurement of this powder, COOH protons (near δ13 ppm) and NHCO protons (near δ11 ppm) specific to polyamic acid were not observed, suggesting that the chemical imidization reaction was complete. . The intrinsic viscosity of the obtained polyimide was 2.30 dL/g, and it was a high molecular weight body.

Preparation of polyimide solution and film forming of polyimide film

The polyimide powder was redissolved in NMP at room temperature to prepare a 15.2 wt% homogeneous solution. This polyimide solution was cast on a glass substrate and dried at 80°C with a hot air dryer for 2 hours. Thereafter, the substrate was dried at 250° C. in vacuum for 1 hour, allowed to cool to room temperature, and then the polyimide film was peeled from the glass substrate. This polyimide film was heat-treated once more at 315°C in vacuum for 1 hour to remove residual strain.

Example 7

Preparation of polyimide solution and film forming of polyimide film

The polyimide powder of Example 6 was redissolved in GBL at room temperature to prepare a 12.4 wt% homogeneous solution. This polyimide solution was cast on a glass substrate and dried at 80°C with a hot air dryer for 2 hours. Thereafter, the substrate was dried at 250° C. in vacuum for 1 hour, allowed to cool to room temperature, and then the polyimide film was peeled from the glass substrate. This polyimide film was heat-treated once more at 315°C in vacuum for 1 hour to remove residual strain.

Example 8

Polyimide precursor polymerization; PMDA (100) / diamine compound 75 mol%

1.3243 g (2.25 mmol) of the diamine compound synthesized in Example 1 and 0.2402 g (0.75 mmol) of 2,2'-bis(trifluoromethyl)benzidine (TFMB) were dissolved in dehydrated NMP. To this was slowly added 0.6544 g (3.00 mmol) of pyromellitic dianhydride (PMDA) powder, followed by stirring at room temperature for 72 hours to obtain polyamic acid as a polyimide precursor (solid content concentration: 15.8 wt%). The obtained polyamic acid had an intrinsic viscosity of 0.74 dL/g.

chemical imidization reaction

After diluting the obtained polyamic acid solution with dehydration NMP to a solid content concentration of 10.0% by weight, a mixed solution of 3.0627 g (30 mmol) acetic anhydride and 1.1865 g (15 mmol) pyridine was slowly added dropwise at room temperature while stirring, After completion, the mixture was stirred for an additional 24 hours. The obtained polyimide solution was slowly dripped at a large amount of ethanol, and the polyimide was precipitated. The resulting precipitate was sufficiently washed with ethanol and vacuum dried at 120°C for 12 hours. As a result of proton NMR measurement of this powder, COOH protons (near δ13 ppm) and NHCO protons (near δ11 ppm) specific to polyamic acid were not observed, suggesting that the chemical imidization reaction was complete. . The intrinsic viscosity of the obtained polyimide was 0.77 dL/g.

Preparation of polyimide solution and film forming of polyimide film

The polyimide powder was redissolved in NMP at room temperature to prepare a 21.4 wt% homogeneous solution. This polyimide solution was cast on a glass substrate and dried at 80°C with a hot air dryer for 2 hours. Thereafter, the substrate was dried at 250° C. in vacuum for 1 hour, allowed to cool to room temperature, and then the polyimide film was peeled from the glass substrate. This polyimide film was heat-treated once more at 259 DEG C in vacuum for 1 hour to remove residual strain.

Example 9

Polyimide precursor polymerization; PMDA (100) / diamine compound 100 mol%

1.7657 g (3.00 mmol) of the diamine compound synthesized in Example 1 was dissolved in dehydrated NMP. To this, 0.6544 g (3.00 mmol) of pyromellitic dianhydride (PMDA) powder was slowly added, followed by stirring at room temperature for 72 hours to obtain polyamic acid as a polyimide precursor (solid content concentration: 14.7 wt%). The obtained polyamic acid had an intrinsic viscosity of 1.11 dL/g.

chemical imidization reaction

After diluting the obtained polyamic acid solution with dehydration NMP to a solid content concentration of 10.0% by weight, a mixed solution of 3.0627 g (30 mmol) acetic anhydride and 1.1865 g (15 mmol) pyridine was slowly added dropwise at room temperature while stirring, After completion, the mixture was stirred for an additional 24 hours. The obtained polyimide solution was slowly dripped at a large amount of ethanol, and the polyimide was precipitated. The resulting precipitate was sufficiently washed with ethanol and vacuum dried at 120°C for 12 hours. As a result of proton NMR measurement of this powder, COOH protons (near δ13 ppm) and NHCO protons (near δ11 ppm) specific to polyamic acid were not observed, suggesting that the chemical imidization reaction was complete. . The obtained polyimide had an intrinsic viscosity of 1.10 dL/g.

Preparation of polyimide solution and film forming of polyimide film

The polyimide powder was redissolved in NMP at room temperature to prepare a 23.6 wt% homogeneous solution. This polyimide solution was cast on a glass substrate and dried at 80°C with a hot air dryer for 2 hours. Thereafter, the substrate was dried at 250° C. in vacuum for 1 hour, allowed to cool to room temperature, and then the polyimide film was peeled from the glass substrate. This polyimide film was heat-treated once more at 348° C. in vacuum to remove residual strain.

Comparative Example 1

Synthesis of dinitro intermediates (synthesis of diamines without methyl groups)

In a 100 mL 3-neck flask, 2-chloro-5-nitrobenzotrifluoride 6.92 g (30.7 mmol), 4,4'-biphenol 1.89 g (10.1 mmol), potassium carbonate 2.89 g, N,N-dimethylformamide (DMF) 15 mL was added, and the mixture was stirred at 85°C under a nitrogen atmosphere for 4 hours. The reaction solution was poured into a large amount of water, and the precipitate was recovered. The precipitate was washed with water and methanol, and then dried in a vacuum dryer at 80° C. for 12 hours (amount 4.91 g, yield 86%). The dried crude product was recrystallized from toluene to obtain white needles (total yield 72%).

Identification of dinitrosomal intermediates

The product is a Fourier transform infrared spectrophotometer FT / IR4100 (Japan Spectroscopic Co., Ltd.) from, 3109 ㎝ ^-1 aromatic C-H stretching absorption band, 1530, a nitro group stretching vibration absorption band, 1243, 1049 ㎝ ^-1 to 1351 ㎝ ^-1 to The ether C-O-C stretch vibration absorption band was confirmed. ^{As a result of performing 1} H-NMR measurement using a Fourier transform nuclear magnetic resonance spectrophotometer JNM-ECP400 (manufactured by JEOL), (DMSO-d ₆ , δ, ppm): 8.55-8.48 (m, 4H), 7.86 (d, J = 8.7 Hz, 4H), 7.38 (d, J = 8.7 Hz, 4H), 7.22 (d, J = 9.2 Hz, 2H), it was confirmed that the product was a dinitro body. Moreover, when melting|fusing point was measured with the differential scanning calorimetry apparatus DSC3100 (Nechi Corporation), it was suggested that this product was highly purified from showing a sharp melting peak at 211 degreeC.

Reduction of dinitrosomal intermediates

In a 200 mL three-necked flask, add 3.00 g (5.32 mmol) of dinitro body, 0.303 g of palladium/carbon (Pd 10%) (about 55% wetted product) as catalyst, and 90 mL of DMF to 100 while bubbling hydrogen. The mixture was stirred at ℃ for 4 hours. Then, after standing to cool to room temperature, the catalyst was separated by filtration, the filtrate was poured into water, and the precipitate was collect|recovered. The precipitate was washed with water and dried in a vacuum dryer at 100° C. for 12 hours (amount 2.48 g, yield 92%). 3.10 g of the obtained crude product was dissolved by heating with ethanol (15 mL), recrystallized, collected by filtration, and dried at 80°C in a vacuum dryer for 12 hours to obtain a gray powder (total yield 65%).

Identification of diamine compounds

The product was obtained from a Fourier transform infrared spectrophotometer FT/IR4100 (manufactured by Nippon Spectroscopy Co., Ltd.) at 3431, 3358 cm ^-1 in N-H stretching vibration absorption band, at 3040 cm ^-1 in aromatic C-H stretching vibration absorption band, 1228, 10479 cm ^{− 1} , the ether C-O-C stretching vibration absorption band was confirmed.

^{As a result of performing 1} H-NMR measurement using a Fourier transform nuclear magnetic resonance spectrophotometer JNM-ECP400 (manufactured by JEOL), (DMSO-d ₆ , δ, ppm): 7.56 (d, J = 8.7 Hz, 4H), 6.94 -6.82(m, 10H), 5.46(s, 4H), elemental analysis values are estimated values C: 61.91%, H: 3.60%, N: 5.55%, actual values C: 61.80%, H: 3.85%, At N:5.51%, it was confirmed that the product was a diamine. Moreover, when melting|fusing point was measured with differential scanning calorimetry DSC3100 (Nechi Corporation), the sharp melting peak was shown at 153 degreeC, and it was suggested that this product is highly purified.

Comparative Example 2

Polyimide precursor polymerization; PMDA (50): s-BPDA (50) / diamine compound 0 mol%

0.9607 g (3.00 mmol) of 2,2'-bis(trifluoromethyl)benzidine (TFMB) was dissolved in dehydrated N-methyl-2-pyrrolidone (NMP). Here, 0.3272 g (1.50 mmol) of pyromellitic dianhydride (PMDA) powder and 0.4413 g (1.50 mmol) of 3,3',4,4'-biphenyltetracarboxylic dianhydride (s-BPDA) powder were mixed. One powder was slowly added and stirred at room temperature for 72 hours to obtain polyamic acid as a polyimide precursor (solid content concentration: 17.4 wt%). The obtained polyamic acid had an intrinsic viscosity of 0.92 dL/g.

chemical imidization reaction

The obtained polyamic acid solution was diluted with dehydrated NMP to a solid content concentration of 10.0% by weight, and a mixed solution of 3.0627 g (30 mmol) acetic anhydride and 1.1865 g (15 mmol) pyridine was slowly added dropwise at room temperature while stirring. It lost fluidity and gelled.

Comparative Example 3

Polyimide precursor polymerization; PMDA (50): s-BPDA (50) / diamine compound (25 mol%)

0.3783 g (0.75 mmol) of the diamine compound synthesized in Comparative Example 1 and 0.7205 g (2.25 mmol) of 2,2'-bis(trifluoromethyl)benzidine (TFMB) were dehydrated N-methyl-2-pyrrolidone ( NMP). Here, 0.3272 g (1.50 mmol) of pyromellitic dianhydride (PMDA) powder and 0.4413 g (1.50 mmol) of 3,3',4,4'-biphenyltetracarboxylic dianhydride (s-BPDA) powder were mixed. One powder was slowly added and stirred at room temperature for 72 hours to obtain polyamic acid as a polyimide precursor (solid content concentration of 28.8% by weight). The obtained polyamic acid had an intrinsic viscosity of 1.38 dL/g.

chemical imidization reaction

After diluting the obtained polyamic acid solution with dehydration NMP to a solid content concentration of 10.0% by weight, a mixed solution of 3.0627 g (30 mmol) acetic anhydride and 1.1865 g (15 mmol) pyridine was slowly added dropwise at room temperature while stirring, After completion, the mixture was stirred for an additional 24 hours. The obtained polyimide solution was slowly dripped at a large amount of ethanol, and the polyimide was precipitated. The resulting precipitate was sufficiently washed with ethanol and vacuum dried at 120°C for 12 hours. As a result of proton NMR measurement of this powder, COOH protons (near δ13 ppm) and NHCO protons (near δ11 ppm) specific to polyamic acid were not observed, suggesting that the chemical imidization reaction was complete. . The intrinsic viscosity of the obtained polyimide was 1.286 dL/g, and it was a high molecular weight body.

Preparation of polyimide solution and film forming of polyimide film

The polyimide powder was redissolved in triethylene glycol dimethyl ether (Tri-GL) at room temperature to prepare an 18.1 wt% homogeneous solution. This polyimide solution was cast on a glass substrate and dried at 80°C with a hot air dryer for 1.5 hours. Thereafter, the substrate was dried at 250° C. in vacuum for 1 hour, allowed to cool to room temperature, and then the polyimide film was peeled from the glass substrate. This polyimide film was heat-treated once more at 260° C. in vacuum to remove residual strain.

Comparative Example 4

Polyimide precursor polymerization; PMDA (50): s-BPDA (50) / diamine compound (50 mol%)

0.7566 g (1.50 mmol) of the diamine compound synthesized in Comparative Example 1 and 0.4803 g (1.50 mmol) of 2,2'-bis(trifluoromethyl)benzidine (TFMB) were dehydrated N-methyl-2-pyrrolidone ( NMP). Here, 0.3272 g (1.50 mmol) of pyromellitic dianhydride (PMDA) powder and 0.4413 g (1.50 mmol) of 3,3',4,4'-biphenyltetracarboxylic dianhydride (s-BPDA) powder were mixed. One powder was slowly added and stirred at room temperature for 72 hours to obtain polyamic acid as a polyimide precursor (solid content concentration: 14.7 wt%). The obtained polyamic acid had an intrinsic viscosity of 1.09 dL/g.

chemical imidization reaction

After diluting the obtained polyamic acid solution with dehydration NMP to a solid content concentration of 10.0% by weight, a mixed solution of 3.0627 g (30 mmol) acetic anhydride and 1.1865 g (15 mmol) pyridine was slowly added dropwise at room temperature while stirring, After completion, the mixture was stirred for an additional 24 hours. The obtained polyimide solution was slowly dripped at a large amount of ethanol, and the polyimide was precipitated. The resulting precipitate was sufficiently washed with ethanol and vacuum dried at 120°C for 12 hours. As a result of proton NMR measurement of this powder, COOH protons (near δ13 ppm) and NHCO protons (near δ11 ppm) specific to polyamic acid were not observed, suggesting that the chemical imidization reaction was complete. . The intrinsic viscosity of the obtained polyimide was 1.90 dL/g, and it was a high molecular weight body.

Preparation of polyimide solution and film forming of polyimide film

The polyimide powder was redissolved in NMP at room temperature to prepare a 18.8 wt% homogeneous solution. This polyimide solution was cast on a glass substrate and dried at 80°C with a hot air dryer for 2 hours. Thereafter, the substrate was dried at 250° C. in vacuum for 1 hour, allowed to cool to room temperature, and then the polyimide film was peeled from the glass substrate. This polyimide film was heat-treated once more at 260° C. in vacuum to remove residual strain.

Comparative Example 5

Polyimide precursor polymerization; PMDA (50): s-BPDA (50) / diamine compound (75 mol%)

1.1349 g (2.25 mmol) of the diamine compound synthesized in Comparative Example 1 and 0.2402 g (0.75 mmol) of 2,2'-bis(trifluoromethyl)benzidine (TFMB) were dehydrated N-methyl-2-pyrrolidone ( NMP). Here, 0.3272 g (1.50 mmol) of pyromellitic dianhydride (PMDA) powder and 0.4413 g (1.50 mmol) of 3,3',4,4'-biphenyltetracarboxylic dianhydride (s-BPDA) powder were mixed. One powder was slowly added and stirred at room temperature for 72 hours to obtain polyamic acid as a polyimide precursor (solid content concentration: 19.0 wt%). The obtained polyamic acid had an intrinsic viscosity of 1.29 dL/g.

chemical imidization reaction

After diluting the obtained polyamic acid solution with dehydration NMP to a solid content concentration of 10.0% by weight, a mixed solution of 3.0627 g (30 mmol) acetic anhydride and 1.1865 g (15 mmol) pyridine was slowly added dropwise at room temperature while stirring, After completion, the mixture was stirred for an additional 24 hours. The obtained polyimide solution was slowly dripped at a large amount of ethanol, and the polyimide was precipitated. The resulting precipitate was sufficiently washed with ethanol and vacuum dried at 120°C for 12 hours. As a result of proton NMR measurement of this powder, COOH protons (near δ13 ppm) and NHCO protons (near δ11 ppm) specific to polyamic acid were not observed, suggesting that the chemical imidization reaction was complete. . The intrinsic viscosity of the obtained polyimide was 2.00 dL/g, and it was a high molecular weight body.

Preparation of polyimide solution and film forming of polyimide film

The polyimide powder was redissolved in NMP at room temperature to prepare a 18.8 wt% homogeneous solution. This polyimide solution was cast on a glass substrate and dried at 80°C with a hot air dryer for 2 hours. Thereafter, the substrate was dried at 250° C. in vacuum for 1 hour, allowed to cool to room temperature, and then the polyimide film was peeled from the glass substrate. This polyimide film was heat-treated once more at 260° C. in vacuum to remove residual strain.

Comparative Example 6

Polyimide precursor polymerization; PMDA (50): s-BPDA (50) / diamine compound (100 mol%)

1.5133 g (3.00 mmol) of the diamine compound synthesized in Comparative Example 1 was dissolved in dehydrated N-methyl-2-pyrrolidone (NMP). Here, 0.3272 g (1.50 mmol) of pyromellitic dianhydride (PMDA) powder and 0.4413 g (1.50 mmol) of 3,3',4,4'-biphenyltetracarboxylic dianhydride (s-BPDA) powder were mixed. One powder was slowly added and stirred at room temperature for 72 hours to obtain polyamic acid as a polyimide precursor (solid content concentration of 20.7% by weight). The obtained polyamic acid had an intrinsic viscosity of 0.84 dL/g.

chemical imidization reaction

After diluting the obtained polyamic acid solution with dehydration NMP to a solid content concentration of 10.0% by weight, a mixed solution of 3.0627 g (30 mmol) acetic anhydride and 1.1865 g (15 mmol) pyridine was slowly added dropwise at room temperature while stirring, After completion, the mixture was stirred for an additional 24 hours. The obtained polyimide solution was slowly dripped at a large amount of ethanol, and the polyimide was precipitated. The resulting precipitate was sufficiently washed with ethanol and vacuum dried at 120°C for 12 hours. As a result of proton NMR measurement of this powder, COOH protons (near δ13 ppm) and NHCO protons (near δ11 ppm) specific to polyamic acid were not observed, suggesting that the chemical imidization reaction was complete. . The intrinsic viscosity of the obtained polyimide was 0.85 dL/g, and it was a high molecular weight body.

Preparation of polyimide solution and film forming of polyimide film

The polyimide powder was redissolved in NMP at room temperature to prepare a 19.2 wt% homogeneous solution. This polyimide solution was cast on a glass substrate and dried at 80°C with a hot air dryer for 2 hours. Thereafter, the substrate was dried at 250° C. in vacuum for 1 hour, allowed to cool to room temperature, and then the polyimide film was peeled from the glass substrate. This polyimide film was heat-treated once more at 245° C. in vacuum to remove residual strain.

About the polyimide film of Examples 2-9, the solution composition for film forming and film|membrane physical property evaluation are put together in Table 1 below, and are shown.

The solvent solubility of the polyimide powders of Examples 2-4, 6, 8, 9 is put together in Table 2 below, and is shown.

About the polyimide film of Comparative Examples 2-6, the solution composition for film forming and film|membrane physical property evaluation are put together in Table 3 below, and are shown.

In addition, the glass transition temperature of Comparative Example 6 shows the value calculated|required from the loss peak in frequency 0.1 Hz, amplitude 0.1%, and a temperature increase rate of 5 degreeC/min using the TA Instruments company make, dynamic viscoelasticity measuring apparatus (Q800).

The polyimide without the diamine compound synthesized in Example 1 was insoluble in the solvent as shown in Comparative Example 2, but the polyimide using the diamine compound synthesized in Example 1 was prepared in the same manner as in Examples 2 to 9. In addition, the glass transition temperature of the polyimide film obtained from the solution was 330 degreeC or more, and it was high temperature. On the other hand, although the polyimide using the diamine compound synthesize|combined in Comparative Example 1 became soluble in a solvent like Comparative Examples 2-6, the glass transition temperature became less than 300 degreeC, and there existed a problem in heat resistance. From these Examples and Comparative Examples, the polyimide using the diamine compound of the present invention in which 6 methyl groups exist at the 2,2',3,3',5,5' positions of the central biphenylene group via an ether bond is , by methyl group, the dihedral angle of the biphenylene group is greatly distorted by the steric hindrance effect (non-coplanarity), preventing aggregation between polymer chains to improve solubility in solvents, and also, the steric hindrance effect is the molecule around the ether bond. Since rotation resistance is also suppressed, it is thought that the heat resistance of the polyimide containing this structure, ie, glass transition temperature, was able to be raised.

Claims (6)

A diamine compound represented by Formula 1 below.
[Formula 1]

(In the formula, R ₁ , R ₂ is a trifluoromethyl group, R ₃ , R ₄ each independently represents an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a, b, c, and d are Each independently represents an integer of 0 to 4. However, the sum of a and c and the sum of b and d are each 4 or less.) A diamine compound represented by Formula 2 below.
[Formula 2]

(In the formula, R ₅ , R ₆ each independently represents a hydrogen atom or a trifluoromethyl group.) A polyimide comprising a structural unit represented by Formula 3 below.
[Formula 3]

(In the formula, R ₁ , R ₂ is a trifluoromethyl group, R ₃ , R ₄ each independently represents an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a, b, c, and d are Each independently represents an integer of 0 to 4, and X represents a tetravalent aromatic and/or aliphatic group, provided that the sum of a and c and the sum of b and d are each 4 or less.) A polyimide comprising a structural unit represented by Formula 4 below.
[Formula 4]

(In the formula, R ₅ and R ₆ each independently represent a hydrogen atom or a trifluoromethyl group, and X represents a tetravalent aromatic and/or aliphatic group.) The polyimide solution which consists of the polyimide of Claim 3 or 4, and a solvent. The polyimide molded object obtained from the polyimide solution of Claim 5.

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