KR102640145B1 - Diamine and its uses - Google Patents

Abstract

(식 중, X는 산소원자 또는 -NH-기를 나타내고, Y는 할로겐원자, 탄소원자수 1 내지 5의 알킬기, 탄소원자수 1 내지 5의 할로알킬기 또는 탄소원자수 1 내지 5의 알콕시기를 나타내고, n은 0~4의 정수를 나타낸다.)[Problem] To provide a novel diamine that provides a film that not only has excellent flexibility and transparency, but also has the characteristics of low retardation.
[Solution] A diamine characterized by the formula (1-1), a polyamic acid and polyimide obtained from this diamine, a composition for forming a film containing this polyimide, and a film and flexible device formed therefrom. Board.

(Wherein, Represents an integer of ~4.)

Description

Diamine and its uses

The present invention relates to diamine and its use.

Recently, with the rapid progress in electronics such as liquid crystal displays and organic electroluminescence displays, there has been a demand for devices to be thinner, lighter, and more flexible.

In these devices, various electronic elements, such as thin film transistors and transparent electrodes, are formed on a glass substrate. However, by changing this glass material to a flexible and lightweight resin material, the device itself can be made thinner, lighter, and more flexible. I'm looking forward to making a fuss.

Under these circumstances, polyimide is attracting attention as an alternative material to glass. In addition to flexibility, polyimide for this application is required to have transparency similar to that of glass in most cases. In order to realize these properties, semicyclic polyimides and fully alicyclic polyimides obtained by using alicyclic diamine components or alicyclic anhydride components as raw materials have been reported (see, for example, Patent Documents 1 and 2).

On the other hand, among the acid dianhydrides and diamines that give aromatic polyimide, acid dianhydrides and diamines with a tryptycene skeleton containing three benzene rings have been reported as raw material compounds that can impart transparency to polyimides (B (see patent documents 1 and 2). Compounds containing such a tryptycene skeleton are attractive as raw materials for creating new aromatic polyimides because they are expected to exhibit unique physical properties due to their characteristic structures.

Japanese Patent Publication No. 2013-147599 Japanese Patent Publication No. 2014-114429 International Publication No. 2011/149018 Pamphlet

Journal of Polymer Science Part A: Polymer Chemistry, Vol. 49, No. 14, p.p. 3109-3120, 2011 Journal of Polymer Research, Vol. 19, no. 1, article 9757, 2012

However, when using a polyimide resin material as a display substrate, it is desirable that the resin material not only has excellent transparency but also has low retardation as one of the required performances.

In other words, retardation (phase difference) refers to the product of the refractive index (difference between two orthogonal refractive indices) and film thickness. This value, especially the retardation in the thickness direction, is an important value that affects the viewing angle characteristics, and a large retardation value Since silver can cause a decrease in the display quality of a display (see, for example, patent document 3), these characteristics in addition to high flexibility (flexibility) are also required for flexible display substrates.

The present invention was made in view of these circumstances, and aims at a diamine that provides a film that not only has excellent flexibility and transparency, but also has the characteristics of low retardation.

The present inventors have conducted extensive studies to solve the above problems, and as a result, diamine compounds represented by the following formula (1-1) have been found, especially those containing fluorine atoms such as 2,2'-di(trifluoromethyl)benzidine. A polyimide soluble in an organic solvent is obtained by copolymerizing an aromatic diamine with an alicyclic tetracarboxylic dianhydride such as tetracyclobutanoic dianhydride, and a composition obtained by dissolving the polyimide in an organic solvent provides flexibility and It was discovered that a film not only excellent in transparency but also characterized by low retardation could be obtained, and the present invention was completed.

That is, the present invention, as a first aspect, relates to a diamine characterized by being represented by formula (1-1).

[Formula 1]

(Wherein,

Y represents a halogen atom, an alkyl group with 1 to 5 carbon atoms, a haloalkyl group with 1 to 5 carbon atoms, or an alkoxy group with 1 to 5 carbon atoms,

n represents an integer from 0 to 4.)

As a second viewpoint, it relates to the diamine described in the first viewpoint, which is a diamine represented by formula (1-2).

[Formula 2]

(In the formula, X represents an oxygen atom or -NH- group.)

As a third viewpoint, it relates to the diamine described in the second viewpoint, which is a diamine represented by formula (1-3).

[Formula 3]

(In the formula, X represents an oxygen atom or -NH- group.)

As a fourth viewpoint, it relates to a polyamic acid obtained by reacting a diamine component containing the diamine described in any one of the first to third viewpoints with an acid dianhydride component.

As a fifth aspect, it relates to the polyamic acid described in the fourth aspect, wherein the diamine component further contains a diamine represented by formula (A1).

[Formula 4]

(In the formula, B ² represents a divalent group selected from the group consisting of formulas (Y-1) to (Y-34).)

[Formula 5]

[Formula 6]

[Formula 7]

[Formula 8]

[Formula 9]

(In the formula, * represents the number of bonds.)

As a sixth aspect, it relates to the polyamic acid according to the fourth or fifth aspect, wherein the acid dianhydride component contains an acid dianhydride represented by formula (C1).

[Formula 10]

[In the formula, B ¹ represents a tetravalent group selected from the group consisting of formulas (X-1) to (X-12).

[Formula 11]

(In the formula, a plurality of R independently represents a hydrogen atom or a methyl group, and * represents the number of bonds.)]

As a seventh viewpoint, it relates to a polyamic acid-containing film forming composition containing the polyamic acid according to any one of the fourth to sixth viewpoints and an organic solvent.

As an eighth aspect, it relates to a film formed from the polyamic acid-containing film-forming composition described in the seventh aspect.

As a ninth aspect, it relates to a substrate for a flexible device made of a film formed from the polyamic acid-containing film-forming composition described in the seventh aspect.

As a tenth viewpoint, it relates to a polyimide obtained by imidizing the polyamic acid described in any one of the fourth to sixth viewpoints.

As an 11th viewpoint, it relates to a film-forming composition containing the polyimide described in the 10th viewpoint and an organic solvent.

As a twelfth aspect, it relates to a film formed from the film-forming composition described in the eleventh aspect.

As a thirteenth aspect, it relates to a substrate for a flexible device made of a film formed from the composition for film formation according to the eleventh aspect.

As a fourteenth aspect, it relates to a dinitro compound represented by formula (2-1).

[Formula 12]

(Wherein,

Y represents a halogen atom, an alkyl group with 1 to 5 carbon atoms, a haloalkyl group with 1 to 5 carbon atoms, or an alkoxy group with 1 to 5 carbon atoms,

n represents an integer from 0 to 4.)

As a 15th aspect, it relates to the dinitro compound described in the 14th aspect, which is a dinitro compound represented by formula (2-2).

[Formula 13]

(In the formula, X represents an oxygen atom or -NH- group.)

As a sixteenth aspect, it relates to the dinitro compound described in the fifteenth aspect, which is a dinitro compound represented by formula (2-3).

[Formula 14]

(In the formula, X represents an oxygen atom or -NH- group.)

As a seventeenth aspect, a method for producing diamine represented by formula (1-1),

[Formula 15]

(Wherein,

Y represents a halogen atom, an alkyl group with 1 to 5 carbon atoms, a haloalkyl group with 1 to 5 carbon atoms, or an alkoxy group with 1 to 5 carbon atoms,

n represents an integer from 0 to 4.)

A production method comprising the step of reducing the nitro group of the dinitro compound represented by Formula (2-1) to obtain a diamine represented by Formula (1-1).

[Formula 16]

(In the formula, X, Y and n have the same meaning as above.)

The novel diamine compound of the present invention can be copolymerized with an alicyclic tetracarboxylic dianhydride, especially with a conventionally known fluorine-containing aromatic diamine, to obtain a polyimide soluble in organic solvents.

Moreover, the polyimide obtained from the diamine compound of the present invention is excellent in flexibility and transparency, and can form a film capable of realizing low retardation.

Furthermore, the film obtained from the film-forming composition containing the polyimide of the present invention is excellent in flexibility and transparency, and especially shows low retardation, so this film can also be suitably used as a substrate for flexible devices, especially flexible displays. You can.

[Diamine compound]

Hereinafter, the present invention will be described in more detail.

The diamine according to the present invention is a diamine represented by the formula (1-1), and in particular, a diamine represented by the formula (1-2) is preferable, and among these, it is excellent in flexibility and transparency, and has the ability to produce a low retardation film. Considering that it can be obtained efficiently, diamine represented by formula (1-3) is preferred.

[Formula 17]

(In the above formula, X represents an oxygen atom or -NH- group,

Y represents a halogen atom, an alkyl group with 1 to 5 carbon atoms, a haloalkyl group with 1 to 5 carbon atoms, or an alkoxy group with 1 to 5 carbon atoms,

n represents an integer from 0 to 4.)

Examples of the halogen atom include a fluorine atom, a chlorine atom, and a bromine atom.

Examples of the alkyl group having 1 to 5 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, and n-pentyl groups. , isoamyl group, neopentyl group, tert-amyl group, sec-isoamyl group, cyclopentyl group, n-hexyl group, etc.

Examples of the haloalkyl group having 1 to 5 carbon atoms include groups in which any arbitrary number of hydrogen atoms at any position in the alkyl group having 1 to 5 carbon atoms are substituted with the halogen atom.

In addition, alkoxy groups having 1 to 5 carbon atoms include methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, isobutoxy group, sec-butoxy group, tert-butoxy group, and n-pentoxy group. group, isopentoxy group, neopentoxy group, tert-pentoxy group, etc.

The diamines represented by the above formulas (1-1) to (1-3) of the present invention can be obtained by reducing the nitro group of dinitro compounds represented by the following formulas (2-1) to (2-3), respectively. .

[Formula 18]

(In the formula, X, Y and n have the same meaning as above.)

Specifically, the diamine represented by the above formula (1-1) is, as an example, 9,10-[1, 2] After synthesizing the benzenoanthracene-9,10-dicarboxylic acid compound (hereinafter also referred to as the benzenoanthracene dicarboxylic acid compound), the benzenoanthracene dicarboxylic acid compound is dissolved in an organic solvent as shown in the following scheme. is a benzenoanthracenedicarboxylic acid chloride compound (step 1), and this acid chloride compound is reacted with nitrophenol compounds or nitroaniline compounds to produce an intermediate (compound represented by formula (2-1)). It can be obtained by reducing the nitro group of this intermediate (second step) and reducing the nitro group of this intermediate (third step). Meanwhile, dinitro compounds represented by the above formulas (2-1) to (2-3), which are intermediates, are also the subject of the present invention.

[Formula 19]

(In the formula, X, Y and n have the same meaning as above.)

In the first step reaction, the method for converting the benzenoanthracenedicarboxylic acid compound into an acid chloride compound may be any known method. There is no particular limitation, but for example, the benzenoanthracenedicarboxylic acid compound may be used as an acid chloride compound. A method of stirring under reflux conditions in the presence of excess thionyl chloride may be used. Meanwhile, during this reaction, the organic solvent may or may not be present, and when this organic solvent is used, the organic solvent may be distilled off simultaneously with the distillation of the thionyl chloride after the reaction. Additionally, the acid chloride compound can be obtained by adding 2 equivalents or more of oxalyl chloride to a benzenoanthracenedicarboxylic acid compound in an organic solvent and stirring the mixture. At this time, a catalyst may be added for the purpose of promoting the reaction.

The organic solvent used in the first step reaction is not particularly limited as long as it is a solvent that does not affect the reaction, and includes aromatic hydrocarbons such as benzene, toluene, xylene, and the like; Aliphatic hydrocarbons such as n-hexane, n-heptane, and cyclohexane; Amides such as N,N-dimethylformamide (hereinafter referred to as DMF), N,N-dimethylacetamide (hereinafter referred to as DMAc), and N-methyl-2-pyrrolidone (hereinafter referred to as NMP) ; Ethers such as diethyl ether, tetrahydrofuran, 1,4-dioxane, 1,2-dimethoxyethane, and cyclopentylmethyl ether, ketones such as 2-butanone and 4-methyl-2-pentanone, and aceto Nitriles such as nitrile, dimethyl sulfoxide (hereinafter referred to as DMSO), halogenated hydrocarbons such as chloroform, dichloromethane, and dichloroethane; etc. can be used. These solvents may be used individually or in combination of two or more types. On the other hand, if the solvent contains a large amount of moisture, hydrolysis of the acid chloride occurs, so it is preferable to use a dehydrating solvent or to use the solvent after dehydration.

The reaction temperature can be any temperature below the boiling point of the solvent used, and can be around 0 to 200°C, but is preferably 0 to 150°C, and more preferably 0 to 80°C.

The catalyst used is not particularly limited as long as it promotes the reaction, but examples include DMF, dimethylaminopyridine, and pyridine. The amount used is not particularly limited, but is usually 0.01 mol% to 50 mol%, preferably 0.1 mol% to 20 mol%, based on the benzenoanthracenedicarboxylic acid chloride compound.

After the reaction, the solvent is distilled off, and the crude product is used as is or purified for use in the next step. The purification method is arbitrary and may be appropriately selected from known methods such as recrystallization, distillation, and silica gel column chromatography.

In the second step reaction, there is no particular limitation on the method of using the benzenoanthracenedicarboxylic acid chloride compound as an intermediate (compound represented by formula (2-1)), for example, in an organic solvent, in the presence of a base. First, a method of reacting (stirring) nitrophenol compounds or nitroaniline compounds with benzenoanthracenedicarboxylic acid chloride compound can be mentioned.

The organic solvent used in the second stage reaction is not particularly limited as long as it is a solvent that does not affect the reaction, and includes aromatic hydrocarbons such as benzene, toluene, xylene, and the like; Aliphatic hydrocarbons such as n-hexane, n-heptane, and cyclohexane; Amides such as N,N-dimethylformamide (hereinafter referred to as DMF), N,N-dimethylacetamide (hereinafter referred to as DMAc), and N-methyl-2-pyrrolidone (hereinafter referred to as NMP) ; Ethers such as diethyl ether, tetrahydrofuran, 1,4-dioxane, 1,2-dimethoxyethane, and cyclopentylmethyl ether, ketones such as 2-butanone and 4-methyl-2-pentanone, and aceto Nitriles such as nitrile, dimethyl sulfoxide (hereinafter referred to as DMSO), halogenated hydrocarbons such as chloroform, dichloromethane, and dichloroethane; etc. can be used. These solvents may be used individually or in combination of two or more types. On the other hand, if the solvent contains a large amount of moisture, hydrolysis of the acid chloride occurs, so it is preferable to use a dehydrating solvent or to use the solvent after dehydration.

The reaction temperature may be below the boiling point of the solvent and may be approximately 0 to 200°C, but is preferably 0 to 100°C, and more preferably 0 to 50°C.

The base used is not particularly limited as long as it can capture by-produced acids, but examples include pyridine, triethylamine, and tributylamine.

After the reaction, the solvent is distilled off, and the crude product is used as is or purified and used in the next step. The purification method is arbitrary and may be appropriately selected from known methods such as recrystallization, distillation, and silica gel column chromatography.

In the third step reaction, a known method may be adopted as a method for reducing the nitro group of the intermediate to an amino group, and there is no particular limitation, but examples include palladium-carbon, platinum oxide, Raney-nickel, and platinum. -Carbon, rhodium-alumina, platinum carbon sulfide, reduced iron, iron chloride, tin, tin chloride, zinc, etc. are used as catalysts, and there is a method using hydrogen gas, hydrazine, hydrogen chloride, ammonium chloride, etc. In particular, catalytic hydrogenation is preferable because side reactions due to the ester portion of the intermediate are unlikely to occur and the target product can be easily obtained.

Hydrogen resources for catalytic hydrogenation include hydrogen gas, hydrazine, hydrogen chloride, ammonium chloride, and ammonium formate.

Catalysts used for catalytic hydrogenation include metal powders such as platinum, palladium, ruthenium, rhodium, nickel, iron, zinc, and tin, and the metal powder may be supported on an activator. The type of catalyst is appropriately determined depending on the type of hydrogen source and reaction conditions, so it is not particularly limited, but any catalyst that can reduce only nitro is sufficient, and preferably palladium-carbon, platinum oxide, Raney-nickel, Platinum-carbon, rhodium-alumina, platinum carbon sulfide, etc. can be mentioned. In addition, the amount of catalyst used is appropriately determined depending on the type of hydrogen source and reaction conditions, so it is not particularly limited, but is usually 0.01 mol% to 50 mol%, preferably 0.01 mol% in terms of metal, relative to the dinitro body (intermediate) of the raw material. It is 0.1 mol% to 20 mol%.

As the reaction solvent, a solvent that does not affect the reaction can be used. For example, ester solvents such as ethyl acetate and methyl acetate, aromatic hydrocarbon solvents such as toluene and xylene, aliphatic hydrocarbon solvents such as n-hexane, n-heptane, and cyclohexane, 1,2-dimethoxyethane, and tetrahydrocarbon solvents. Ether-based solvents such as hydrofuran and dioxane, alcohol-based solvents such as methanol and ethanol, ketone-based solvents such as 2-butanone and 4-methyl-2-pentanone, N,N-dimethylformamide, N,N -Aprotic polar solvents such as dimethylacetamide, N-methyl-2-pyrrolidone, and dimethyl sulfoxide, and water are included. These solvents can be used individually or in combination of two or more types.

The reaction temperature can be carried out at a temperature at which the reaction proceeds efficiently as long as the raw materials or products do not decompose and is below the boiling point of the solvent used. Specifically, a temperature of -78°C to less than the boiling point of the solvent is preferable, and from the viewpoint of simplicity of synthesis, a temperature of 0°C to less than the boiling point of the solvent is more preferable, more preferably 0 to 100°C, even more preferable. Typically, it is 10 to 50 degrees Celsius.

In addition, catalytic hydrogenation can also be performed under pressurized conditions, such as by using an autoclave, from the viewpoint of improving the reaction rate and enabling the reaction at low temperature.

After the reaction, the solvent is removed and purified using known methods such as recrystallization, distillation, and silica gel column chromatography to obtain the target diamine. On the other hand, if the solvent contains a lot of oxygen, coloring of the produced diamine compound may occur, so it is preferable to use the solvent used for reaction and purification after degassing. In addition, in order to further prevent coloring, it is preferable to degas the reaction solution before and after the solvent is removed after the reaction.

In addition, the benzenoanthracenedicarboxylic acid compound used in the present invention can be obtained by the method described in JOURNAL OF POLYMER SCIENCE: PART A-1 vol.6, 2955-2965 (1968), as described above.

[Polyamic acid and polyimide]

The diamine component containing the diamine of the present invention described above can be converted into a polyamic acid through a polycondensation reaction with an acid dianhydride component, and then converted into the corresponding polyimide by a dehydration ring closure reaction using heat or a catalyst. Both polyamic acid and polyimide are the subject of the present invention. Meanwhile, the polyamic acid of the present invention is a reaction product of a diamine component including the diamine of the present invention and an acid dianhydride component, and the polyimide of the present invention is an imidate of the polyamic acid.

From the viewpoint of obtaining polyamic acid and polyimide with good reproducibility, which provide a film that not only has excellent flexibility and transparency but also has the characteristics of low retardation, the diamine component used in the production of the polyamic acid of the present invention is of the above formula of the present invention. In addition to the diamine represented by (1-1), it preferably contains a fluorinated atom aromatic diamine, and more preferably contains a diamine represented by the following formula (A1).

[Formula 20]

(In the formula, B ² represents a divalent group selected from the group consisting of formulas (Y-1) to (Y-34).)

[Formula 21]

[Formula 22]

[Formula 23]

[Formula 24]

[Formula 25]

(In the formula, * represents the number of bonds.)

Among the diamines represented by the above formula (A1), B ² in the formula is one of the above formulas (Y-12), (Y-13), (Y-14), (Y-15), (Y-18), (Y Diamines represented by -27), (Y-28), (Y-30), and (Y-33) are preferred, and B ² is represented by the formula (Y-12), (Y-13), (Y- Diamines represented by 14), (Y-15), and (Y-33) are particularly preferred.

Additionally, within the range that does not impair the effect of the present invention, other diamine compounds other than the diamine represented by the formula (1-1) and the diamine represented by the formula (A1) may be used as the diamine component. .

In the diamine component, when a fluorinated atom aromatic diamine is used together with the diamine represented by the formula (1-1) of the present invention, the diamine represented by the formula (1-1) and the fluorinated atom aromatic The molar ratio of diamine is usually diamine: fluorine-containing aromatic diamine represented by the above formula (1-1) = 1:1 to 1:10. By setting this range, brittleness of the film can be suppressed, and a film with a low linear expansion coefficient can be obtained with good reproducibility.

From the viewpoint of reproducibly obtaining polyamic acid and polyimide that provide a film that not only has excellent flexibility and transparency but also has the characteristics of low retardation, the acid dianhydride component used in the production of the polyamic acid of the present invention is preferably an alicyclic It contains tetracarboxylic dianhydride, more preferably acid dianhydride represented by the formula (C1) below.

[Formula 26]

[In the formula, B ¹ represents a tetravalent group selected from the group consisting of formulas (X-1) to (X-12).

[Formula 27]

(In the formula, a plurality of R independently represents a hydrogen atom or a methyl group, and * represents the number of bonds.)]

Among the acid dianhydrides represented by the above formula (C1), B ¹ in the formula is one of the above formulas (X-1), (X-2), (X-4), (X-5), (X-6), ( Acid ^dianhydrides represented by Acid dianhydrides represented by X-2), (X-4), (X-6), (X-7), (X-11), and (X-12) are particularly preferred.

Among them, it is preferable to use two or more types of acid dianhydride represented by (C1).

From the viewpoint of reproducibly obtaining polyamic acids and polyimides that provide a film with high flexibility, high transparency, and low retardation, the content of alicyclic tetracarboxylic dianhydride in the acid dianhydride component used in the production of the polyamic acid of the present invention is preferable. Preferably it is 50 mol% or more, more preferably 60 mol% or more, even more preferably 70 mol% or more, even more preferably 80 mol% or more, even more preferably 90 mol% or more, and most preferably 100 mol%. .

On the other hand, when the diamine represented by the formula (1-1) and the diamine represented by the formula (A1) are used as the diamine component, and the acid dianhydride represented by (C1) is used as the acid dianhydride component, polya Mixic acid has a monomer unit represented by the following formula (4-1) and a monomer unit represented by the following formula (4-2).

[Formula 28]

(In the formula, X, Y, n, B ¹ and B ² have the same meaning as above.)

The method for obtaining the polyamic acid of the present invention is not particularly limited, and the above-mentioned acid dianhydride component and diamine component may be reacted and polymerized by a known method.

When synthesizing polyamic acid, the ratio of the number of moles of the acid dianhydride component to the number of moles of the diamine component is acid dianhydride component/diamine component = 0.8 to 1.2.

Solvents used in polyamic acid synthesis include, for example, m-cresol, N-methyl-2-pyrrolidone (NMP), N,N-dimethylformamide (DMF), and N,N-dimethylacetamide ( DMAc), N-methylcaprolactam, dimethylsulfoxide (DMSO), tetramethylurea, pyridine, dimethylsulfone, hexamethylphosphoramide, γ-butyrolactone, etc. These may be used individually or in mixture. Additionally, even if it is a solvent that does not dissolve polyamic acid, it can be used by adding it to the solvent within the range of obtaining a uniform solution.

The temperature for the polycondensation reaction can be selected at any temperature from -20 to 150°C, preferably -5 to 100°C.

The polyamic acid-containing solution obtained by the polymerization reaction of the polyamic acid described above can be used as is, or after dilution or concentration, as a polyamic acid-containing film-forming composition for forming a polyimide film described later. Additionally, a poor solvent such as methanol or ethanol is added to this polyamic acid-containing solution to precipitate the polyimide to isolate the polyamic acid, and the isolated polyamic acid is re-dissolved in an appropriate solvent to form a polyamic acid-containing film, which will be described later. It can also be used as a composition.

The solvent for diluting the polyamic acid-containing solution and the solvent for re-dissolving the isolated polyamic acid is not particularly limited as long as it dissolves the obtained polyamic acid. For example, m-cresol, 2-pyrrolidone, NMP, N- Examples include ethyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, DMAc, DMF, and γ-butyrolactone.

In addition, even if it is a solvent that does not dissolve polyamic acid alone, it can be used by adding it to the solvent as long as it is within the range in which polyamic acid does not precipitate. Specific examples include ethyl cellosolve, butyl cellosolve, ethyl carbitol, butyl carbitol, ethyl carbitol acetate, ethylene glycol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 1-Butoxy-2-propanol, 1-phenoxy-2-propanol, propylene glycol monoacetate, propylene glycol diacetate, propylene glycol-1-monomethyl ether-2-acetate, propylene glycol-1-monoethyl ether- Examples include 2-acetate, dipropylene glycol, 2-(2-ethoxypropoxy)propanol, methyl lactate, ethyl lactate, n-propyl lactate, n-butyl lactate, and isoamyl lactate. .

The polyimide of the present invention can be obtained by dehydrating the polyamic acid described above by heating (thermal imidization) or chemically ring-closing it using a known dehydration ring-closing catalyst.

The heating method can be performed at any temperature of 100 to 300°C, preferably 120 to 250°C.

The chemical ring closure method can be performed, for example, in the presence of pyridine, triethylamine, 1-ethylpiperidine, etc., and acetic anhydride, and the temperature at this time is any temperature between -20 and 200°C. You can choose.

The polyimide obtained from the polyamic acid having the monomer unit represented by the formula (4-1) and the monomer unit represented by the formula (4-2) thus obtained is a monomer unit represented by the formula (5-1) below. and has a monomer unit represented by the following formula (5-2).

[Formula 29]

(In the formula, X, Y, n, B ¹ and B ² have the same meaning as above.)

The polyimide solution obtained by the ring-closure reaction of the polyamic acid described above can be used as is or after dilution or concentration as a film-forming composition described later. Additionally, a poor solvent such as methanol or ethanol is added to this polyimide solution to precipitate the polyimide to isolate the polyimide. The isolated polyimide is re-dissolved in an appropriate solvent and used as a film-forming composition described later. You can.

The solvent for re-dissolution is not particularly limited as long as it dissolves the obtained polyimide, and examples include m-cresol, 2-pyrrolidone, NMP, N-ethyl-2-pyrrolidone, and N-vinyl-2- Pyrrolidone, DMAc, DMF, γ-butyrolactone, etc. can be mentioned.

In addition, even if it is a solvent that does not dissolve polyimide alone, it can be used by adding it to the solvent as long as it is within the range in which polyimide does not precipitate. Specific examples include ethyl cellosolve, butyl cellosolve, ethyl carbitol, butyl carbitol, ethyl carbitol acetate, ethylene glycol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 1-Butoxy-2-propanol, 1-phenoxy-2-propanol, propylene glycol monoacetate, propylene glycol diacetate, propylene glycol-1-monomethyl ether-2-acetate, propylene glycol-1-monoethyl ether- Examples include 2-acetate, dipropylene glycol, 2-(2-ethoxypropoxy)propanol, methyl lactate, ethyl lactate, n-propyl lactate, n-butyl lactate, and isoamyl lactate. .

In the present invention, the number average molecular weight of the polyamic acid (polyimide) is preferably 5,000 or more, more preferably 10,000 or more, and even more preferably 15,000 or more from the viewpoint of improving the flexibility, strength, etc. of the resulting film. From the viewpoint of ensuring the solubility of the resulting polyimide, it is preferably 200,000 or less, more preferably 100,000 or less, and even more preferably 50,000 or less. Meanwhile, in this specification, the number average molecular weight is a value measured by a GPC (gel permeation chromatography) device and calculated as a value converted to polyethylene glycol and polyethylene oxide.

[Film-forming composition / Polyamic acid-containing film-forming composition]

The film-forming composition containing the polyimide of the present invention and an organic solvent described above, and the polyamic acid-containing film-forming composition containing the polyamic acid of the present invention and an organic solvent are also subject to the present invention. Here, the film-forming composition and the polyamic acid-containing film-forming composition of the present invention are uniform, and no phase separation is observed.

<Organic solvent>

The film-forming composition or polyamic acid-containing film-forming composition of the present invention contains an organic solvent in addition to the polyimide or polyamic acid. This organic solvent is not particularly limited, and examples thereof include those similar to specific examples of the reaction solvent used in preparing the polyamic acid and polyimide. More specifically, N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, N-ethyl-2- Pyrrolidone, γ-butyrolactone, etc. can be mentioned. On the other hand, the organic solvent may be used individually or in combination of two or more types.

Among these, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, and γ-butyrolactone are preferable considering obtaining a highly flat film with good reproducibility.

The solid content in the film-forming composition or polyamic acid-containing film-forming composition of the present invention is usually about 0.5 to 30% by mass, preferably about 5 to 25% by mass. If the solid concentration is less than 0.5% by mass, the film forming efficiency decreases when producing a film, and the viscosity of the film forming composition or the polyamic acid-containing film forming composition decreases, making it difficult to obtain a film with a uniform surface. In addition, if the solid concentration exceeds 30% by mass, the viscosity of the film-forming composition or the polyamic acid-containing film-forming composition becomes too high, which may eventually lead to deterioration of film-forming efficiency or lack of surface uniformity of the coating film. Meanwhile, the solid content here refers to the total mass of components other than the organic solvent, and even liquid monomers etc. can be included in the weight as solid content.

On the other hand, the viscosity of the film-forming composition or the polyamic acid-containing film-forming composition is set appropriately in consideration of the thickness of the film to be produced, etc., but especially when the goal is to obtain a film with a thickness of about 5 to 50 μm with good reproducibility, Usually, it is about 500 to 50,000 mPa·s at 25°C, preferably about 1,000 to 20,000 mPa·s.

In order to impart processing characteristics and various functionalities to the film-forming composition or the polyamic acid-containing film-forming composition of the present invention, various other organic or inorganic low-molecular-weight or high-molecular compounds may be added. For example, catalysts, antifoaming agents, leveling agents, surfactants, dyes, plasticizers, fine particles, coupling agents, sensitizers, etc. can be used. For example, a catalyst may be added for the purpose of retardation of the membrane or lowering the coefficient of linear expansion. Meanwhile, a film-forming composition or a polyamic acid-containing film-forming composition that is added to the polyimide or polyamic acid and an organic solvent and further contains silicon dioxide particles or a catalyst can also be used as the subject of the present invention.

On the other hand, in the solid content of the film-forming composition or polyamic acid-containing film-forming composition of the present invention, including the case where other components are included, the proportion of the polyimide or polyamic acid can be 70 to 100% by mass. .

The film-forming composition or polyamic acid-containing film-forming composition of the present invention can be obtained by dissolving the polyimide or polyamic acid obtained by the above-described method in the above-described organic solvent, and the reaction after preparation of the polyimide or polyamic acid The above organic solvent may be additionally added to the solution as needed.

[membrane]

The film-forming composition or polyamic acid-containing film-forming composition of the present invention described above is applied to a substrate, dried and heated to remove the organic solvent, and has high heat resistance, high transparency, appropriate flexibility, and an appropriate linear expansion coefficient, In addition, a film with small retardation can be obtained.

That is, by heating the polyamic acid-containing film-forming composition (polyamic acid-containing solution) applied on a substrate and performing an imidization reaction while evaporating the solvent, the film of the present invention containing polyimide can be obtained, and this film can be obtained. It consists of the solid content of the polyamic acid-containing film-forming composition, and contains imidized products of the polyamic acid in this solid content.

Alternatively, the film-forming composition (polyimide-containing solution, also referred to as polyimide solution) applied on a substrate is heated and the solvent is evaporated to obtain the film of the present invention containing polyimide, and this film has the above-described film. It consists of the solid content of the film-forming composition.

And the film, that is, the film (thin film) containing the polyimide, is also the subject of the present invention.

Base materials used in the production of membranes include, for example, plastics (polycarbonate, polymethacrylate, polystyrene, polyester, polyolefin, epoxy, melamine, triacetylcellulose, ABS, AS, norbornene-based resin, etc.), metal, and stainless steel. Examples include steel (SUS), wood, paper, glass, silicon wafer, and slate.

In particular, in the case of application as a substrate material for electronic devices, it is preferable that the applied substrate is glass or a silicon wafer from the viewpoint of being able to use existing equipment, and it is even more preferable to use glass because the resulting film exhibits good peelability. desirable. Meanwhile, the linear expansion coefficient of the applied substrate is preferably 35 ppm/℃ or less, more preferably 30 ppm/℃ or less, even more preferably 25 ppm/℃ or less, from the viewpoint of warping of the substrate after coating. , 20ppm/℃ or less.

The application method of the film-forming composition or polyamic acid-containing film-forming composition to the substrate is not particularly limited, but includes, for example, cast coat method, spin coat method, blade coat method, dip coat method, and roll coat method. , barcoat method, die-coat method, inkjet method, printing method (convex plate, intaglio plate, flat panel, screen printing, etc.), etc., and these can be used appropriately depending on the purpose.

The heating temperature is usually about 40 to 500°C, but is preferably 300°C or lower. If the temperature exceeds 300°C, the resulting film may become brittle, making it impossible to obtain a film particularly suitable for use as a display substrate.

In addition, considering the heat resistance and linear expansion coefficient characteristics of the resulting film, the applied film-forming composition or polyamic acid-containing film-forming composition is heated at 40°C to 100°C for 5 minutes to 2 hours, and then the heating temperature is gradually raised. and finally heating at a temperature exceeding 175°C to 280°C for 30 minutes to 2 hours. In this way, low linear expansion characteristics can be developed by heating at a temperature of two or more stages: drying the solvent and promoting molecular orientation.

In particular, the applied film-forming composition is heated at 40°C to 100°C for 5 minutes to 2 hours, then heated at over 100°C to 175°C for 5 minutes to 2 hours, then at over 175°C to 280°C for 5 minutes~ It is desirable to heat for 2 hours.

Apparatuses used for heating include, for example, hot plates and ovens. The heating atmosphere may be under air or an inert gas such as nitrogen, and may be under normal pressure or reduced pressure, and different pressures may be applied at each stage of heating.

The thickness of the film, especially when used as a flexible display substrate, is usually about 1 to 60 μm, preferably about 5 to 50 μm, and the thickness of the coating film before heating is adjusted to form a film of the desired thickness.

On the other hand, there is no particular limitation on the method of peeling the film formed in this way from the substrate, and examples include a method of peeling the film by cooling it for each substrate and cutting the film, or a method of peeling the film by applying tension through a roll. .

And, a flexible device substrate made of a film formed from the film-forming composition or the polyamic acid-containing film-forming composition, that is, a flexible device made of a cured product of the film-forming composition or a cured product of the polyamic acid-containing film-forming composition. A device substrate is also the subject of the present invention.

Example

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these. Meanwhile, the abbreviations of the reagents used, the equipment used, and its conditions are as follows.

DCT: Dicarboxyl Triptycene

DCTCl: Triptycene Dicarbonyl Chloride

DCTDNB: Dicarboxyl Triptycene Dinitrobenzoate

DCTDAB: Dicarboxyl Triptycene Diaminobenzoate

DCTDNBA: Dicarboxyl Triptycene Dinitrobenzamide

DCTDABA: Dicarboxyl Triptycene Diaminobenzamide

<HPLC analysis>

Column: Inertsil ODS-3, 5μm, 4.6×250mm

Oven: 40℃, detection wavelength: 217nm, 254nm, flow rate: 1.0mL/min.

Eluent:

DCT: Acetonitrile/0.5% phosphoric acid aqueous solution=50/50 Sample injection volume: 10μL

DCTCl: Acetonitrile/0.5% phosphoric acid aqueous solution=50/50 Sample injection volume: 10μL

DCTDNB: Acetonitrile/0.5% phosphoric acid aqueous solution=70/30 Sample injection volume: 10μL

DCTDAB: Acetonitrile/0.5% phosphoric acid aqueous solution = 40/60 Sample injection volume: 10μL

DCTDNBA: Acetonitrile/0.5% phosphoric acid aqueous solution = 70/30 Sample injection volume: 10μL

DCTDABA: Acetonitrile/water=70/30 Sample injection volume: 10μL

< ^1H NMR analysis>

Device: Fourier transform superconducting nuclear magnetic resonance (FT-NMR) (INOVA-400 (Varian) 400 MHz

Solvent: DMSO-d6, CDCl ₃

Internal standard: tetramethylsilane (TMS)

<Measurement of number average molecular weight (Mn) and weight average molecular weight (Mw)>

Device: Showdex GPC-101, manufactured by Showa Denko Co., Ltd.

Column: KD803 and KD805

Column temperature: 50℃

Elution solvent: DMF, flow rate: 1.5ml/min.

Calibration curve: standard polystyrene

[1] Synthesis of DCTDAB and DCTDABA

[Synthesis Example 1-1: Synthesis of DCTDNB]

Under a nitrogen atmosphere, DCT (14.0 g) and N,N-dimethylformamide (1.4 g) were added to chloroform (210 g), and thionyl chloride (48.8 g) was added dropwise over 15 minutes, and then stirred under reflux conditions. (Stirred at 61°C for 3.5 hours. After confirming the completion of the reaction by HPLC, N,N-dimethylformamide, chloroform, and thionyl chloride were distilled off under reduced pressure to obtain crude DCTCl.

At room temperature, under a nitrogen atmosphere, the DCTCl crude product was dissolved in N,N-dimethylformamide (311g), and 4-nitrophenol (12.6g), triethylamine (12.5g), and N,N-dimethylformamide ( 62.2 g) of the mixed solution was added dropwise over 30 minutes and stirred at room temperature for 16 hours. Water (351 g) was added to the reaction solution, and after stirring for 30 minutes, the precipitate was collected by filtration and washed twice with water (150 g) and twice with methanol (150 g). The filtered product (29.9 g) was dried under reduced pressure at 50°C to obtain 21.5 g of DCTDNB crude product.

Next, this DCTDNB crude product (20.5 g) was added to tetrahydrofuran (205 g), stirred at 50°C for 1 hour, filtered, and the filtered product was washed twice with tetrahydrofuran (20 g). This operation was performed again, and the resulting filtrate (22.5 g) was dried under reduced pressure at 50°C, and 18.5 g of DCTDNB crystals were obtained (yield: 77.0%, HPLC white value (retention time: 30.9 min); 99.5%). ¹ From the HNMR analysis results, it was confirmed that this crystal was DCTDNB.

¹ HNMR(DMSO-d6, δ4H), 8.0(m,4H), 8.0(m,6H), 7.3(m,6H).

[Example 1-1: Synthesis of DCTDAB]

In the reaction vessel, DCTDNB (6.1 g) obtained in Synthesis Example 1-1, 5% Pd-C (STD type, wet product, manufactured by NKEMCAT Co., Ltd., 0.61 g), N, N-dimethylformamide (91.7 g) was added, the inside of the reaction vessel was replaced with hydrogen, and then stirred at room temperature for 21 hours under the condition of a hydrogen pressure of 0.8 MPa. The same manipulation was performed twice on the DCTDNB (6.1 g) scale.

Completion of the reaction was confirmed by HPLC, the reaction solutions were combined, and Pd-C was removed from the reaction mixture by filtration. This Pd-C was washed twice with N,N-dimethylformamide (37 g), and washed with N,N-dimethylformamide (37 g). The N,N-dimethylformamide used was recovered along with the filtrate. After water (361.8 g) was added dropwise to this filtrate, the precipitate was recovered by filtration, and the filtrate was washed three times with water (37 g). This filtered material (21.0 g) was dried under reduced pressure at 50°C to obtain 15.9 g of DCTDAB filtered material. This DCTDAB residue was added to N,N-dimethylformamide (191 g), heated to 50°C to dissolve, and then cooled to 5°C. After this, isopropyl alcohol (382 g) was added dropwise, and after stirring for 1 hour, the precipitate was collected by filtration and washed twice with isopropyl alcohol (37 g). By drying the filtered product (17.5 g) under reduced pressure at 50°C, 12.7 g of DCTDAB crystals were obtained (yield: 75.2%, HPLC white value (retention time: 6.1 min); 99.3%). ¹ From the HNMR analysis results, it was confirmed that this crystal was DCTDAB.

¹ HNMR(DMSO-d6, δ7.3(m,4H), 7.2(m,6H), 6.8(m,4H), 5.3(s,4H).

[Formula 30]

[Synthesis Example 1-2: Synthesis of DCTDNBA]

Under a nitrogen atmosphere, DCT (16.2g) and N,N-dimethylformamide (1.6g) were added to chloroform (292g), and thionyl chloride (56.4g) was added dropwise over 15 minutes, followed by refluxing conditions. It was stirred at 61°C for 3.5 hours. After confirming the completion of the reaction by HPLC, N,N-dimethylformamide, chloroform, and thionyl chloride were distilled off under reduced pressure to obtain crude DCTCl.

Under a nitrogen atmosphere, the DCTCl crude product was added to tetrahydrofuran (126 g), cooled to 5°C, and then added to a mixed solution of 4-nitroaniline (14.4 g), triethylamine (10.6 g), and tetrahydrofuran (143.8 g). was added dropwise over 30 minutes, then the temperature was raised to room temperature and stirred for 20 hours. Water (539 g) was added to the reaction solution, and after stirring for 30 minutes, the precipitate was collected by filtration and washed twice with water (90 g) and twice with methanol (90 g). The filtered product (36.3 g) was dried under reduced pressure at 70°C to obtain 25.0 g of crude DCTDNBA.

Next, this DCTDNBA crude product (25.0 g) was added to N,N-dimethylformamide (250 g), dissolved at 80°C, and then cooled to room temperature. Methanol (750 g) was added dropwise, stirred for 1 hour, filtered, and the filtrate was washed three times with methanol (54 g). The obtained filtrate (29.4 g) was dried under reduced pressure at 70°C, and 21.6 g of DCTDNBA crystals were obtained (yield: 77.8%, HPLC white value (retention time: 20.7 min); 99.8%). ¹ From the HNMR analysis results, it was confirmed that this crystal was DCTDNBA.

¹ HNMR(DMSO-d6, δ2H), 8.3(m, 4H), 8.2(m,4H), 8.0(m,6H), 7.2(m,6H).

[Example 1-2: Synthesis of DCTDABA]

In the reaction vessel, DCTDNBA (7.2 g) obtained in Synthesis Example 1-2, 5% Pd-C (STD type, wet product, manufactured by NKEMCAT Co., Ltd., 0.61 g), N, N-dimethylformamide (72 g) ) was added, the inside of the reaction vessel was replaced with hydrogen, and then stirred at room temperature for 23 hours under the condition of a hydrogen pressure of 0.8 MPa. The same manipulation was performed twice on the DCTDNBA (7.2 g) scale.

Completion of the reaction was confirmed by HPLC, the reaction solutions were combined, and Pd-C was removed from the reaction mixture by filtration. This Pd-C was washed twice with N,N-dimethylformamide (43 g), and washed with N,N-dimethylformamide (43 g). The N,N-dimethylformamide used was recovered along with the filtrate. After adding 1 drop of hydrazine to this filtrate, water (1250 g) was added dropwise. After filtering the precipitate, the filtered material was washed twice with water (43 g). By drying this filtered material under reduced pressure at 70°C, 18.6 g of DCTDABA crystals were obtained (yield: 96.1%, HPLC white value (retention time: 4.5 min); 99.6%). ¹ From the HNMR analysis results, it was confirmed that this crystal was DCTDABA.

¹ HNMR(DMSO-d6, δ8.0(m,6H), 7.5(m,4H), 7.1(m,6H), 6.6(m,4H), 5.0(s,4H).

[Formula 31]

[2] Synthesis of polyimide

[Example 2-1]

In a nitrogen-purged flask, 2.478 g (0.0077 mol) of 2,2'-di(trifluoromethyl)benzidine (TFMB) and 0.4511 g (0.00085 mol) of DCTDAB were placed. 9.47 g of N-methyl-2-pyrrolidone (NMP) was added thereto and stirred to confirm that TFMB and DCTDAB were dissolved. Again, 0.9639 g (0.0043 mol) of 2,3,5-tricarboxycyclopentylacetic acid-1,4:2,3-dianhydride (TCA) and 3.789 g of NMP were added. Then, the obtained mixture was stirred at 90°C for 4 hours under a nitrogen atmosphere, the reaction mixture was cooled to 50°C, and then 0.8432 g (0.0043 g) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA) was added again. mol) and 5.684 g of NMP were added and stirred overnight.

Afterwards, the reaction mixture was diluted using NMP so that the solid concentration was 8% by mass, and 3.512 g (0.0344 mol) of acetic anhydride and 2.04 g (0.0258 mol) of pyridine were added to the diluted reaction mixture, and then incubated under a nitrogen atmosphere. , and stirred at 90°C for 4 hours.

Next, the obtained reaction mixture was added dropwise into 350 g of methanol, stirred for 30 minutes, and the precipitate was recovered by filtration. This operation was repeated three times.

Finally, the obtained residue was dried at 150°C for 8 hours under reduced pressure to obtain polyimide (I) (3.26 g yield: 73.6%).

[Example 2-2]

In a nitrogen-purged flask, 1.838 g (0.0057 mol) of 2,2'-di(trifluoromethyl)benzidine (TFMB) and 1.2904 g (0.0025 mol) of DCTDAB were placed. 9.703 g of N-methyl-2-pyrrolidone (NMP) was added thereto and stirred to confirm that TFMB and DCTDAB were dissolved. Again, 0.919 g (0.0041 mol) of 2,3,5-tricarboxycyclopentylacetic acid-1,4:2,3-dianhydride (TCA) and 3.881 g of NMP were added. Then, the obtained mixture was stirred at 90°C for 4 hours under a nitrogen atmosphere, the reaction mixture was cooled to 50°C, and then 0.804 g (0.0041 g) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA) was added again. mol) and 5.822 g of NMP were added and stirred overnight.

Afterwards, the reaction mixture was diluted using NMP so that the solid concentration was 8% by mass, and 3.348 g (0.0328 mol) of acetic anhydride and 1.946 g (0.0246 mol) of pyridine were added to the diluted reaction mixture, and then incubated under a nitrogen atmosphere. , and stirred at 90°C for 4 hours.

Next, the obtained reaction mixture was added dropwise into 350 g of methanol, stirred for 30 minutes, and the precipitate was recovered by filtration. This operation was repeated three times.

Finally, the obtained residue was dried at 150°C for 8 hours under reduced pressure to obtain polyimide (II) (3.12 g yield: 68.4%).

[Example 2-3]

In a nitrogen-purged flask, 2.882 g (0.009 mol) of 2,2'-di(trifluoromethyl)benzidine (TFMB) and 0.5245 g (0.001 mol) of DCTDAB were placed. 15.78 g of N-methyl-2-pyrrolidone (NMP) was added thereto and stirred to confirm that TFMB and DCTDAB were dissolved. Again, 1.251 g (0.005 mol) of bicyclo[3,3,0]octane-2,4,6,8-tetracarboxylic dianhydride (BODA) and 3.38 g of NMP were added. Then, the obtained mixture was stirred at 90°C for 4 hours under a nitrogen atmosphere, the reaction mixture was cooled to 50°C, and then 0.9805 g (0.005 g) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA) was added again. mol) and 3.38 g of NMP were added and stirred overnight.

Afterwards, the reaction mixture was diluted using NMP so that the solid concentration was 8% by mass, and 4.08 g (0.04 mol) of acetic anhydride and 2.373 g (0.03 mol) of pyridine were added to the diluted reaction mixture, and then incubated under a nitrogen atmosphere. , and stirred at 100°C for 4 hours.

Next, the obtained reaction mixture was added dropwise into 100 g of methanol, stirred for 30 minutes, and the precipitate was recovered by filtration. This operation was repeated three times.

Finally, the obtained residue was dried at 150°C for 8 hours under reduced pressure to obtain polyimide (III) (4.91 g yield: 87.0%).

[Example 2-4]

In a flask purged with nitrogen, 8.64 g (0.027 mol) of 2,2'-di(trifluoromethyl)benzidine (TFMB) and 1.573 g (0.003 mol) of DCTDAB were placed. 52.99 g of N-methyl-2-pyrrolidone (NMP) was added thereto and stirred to confirm that TFMB and DCTDAB were dissolved. Again, 5.765 g (0.015 mol) of norbonane-2-spiro-α-cyclopentanone-α'-spiro-2”norbonane-5,5””tetracarboxylic dianhydride (CpODA) and 11.35 g of NMP were added. . Then, the obtained mixture was stirred at 90°C for 10 minutes under a nitrogen atmosphere, and then 2.942 g (0.015 mol) of 1,2,3,4-cyclobutane tetracarboxylic dianhydride (CBDA) and 11.35 g of NMP were added, After that, it was stirred at 180°C for 7 hours.

Thereafter, at room temperature, the reaction mixture was added dropwise into 350 g of methanol, stirred for 30 minutes, and the precipitate was recovered by filtration. This operation was repeated three times.

Finally, the obtained residue was dried at 150°C for 8 hours under reduced pressure to obtain polyimide (IV) (16.08 g yield: 85.0%).

[Example 2-5]

In a nitrogen-purged flask, 5.764 g (0.018 mol) of 2,2'-di(trifluoromethyl)benzidine (TFMB) and 1.049 g (0.002 mol) of DCTDAB were placed. 31.57 g of γ-butyrolactone (GBL) was added thereto and stirred to confirm that TFMB and DCTDAB were dissolved. Again 2.5 g (0.01 mol) of bicyclo[2,2,2]octane-2,3:5,6-tetracarboxylic dianhydride (BODAxx), 6.84 g of γ-butyrolactone (GBL), and 1-ethyl. 0.23 g of piperidine was added. Then, the obtained mixture was stirred at 140°C for 3 hours under a nitrogen atmosphere, and then 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA) 1.9611 g (0.01 mol) and γ-butyrolactone (GBL) were added. ) 6.84 g and 0.23 g of 1-ethylpiperidine were added, and then stirred at 180°C for 7 hours.

Thereafter, at room temperature, the reaction mixture was added dropwise into 350 g of methanol, stirred for 30 minutes, and the precipitate was recovered by filtration. This operation was repeated three times.

Finally, the obtained residue was dried at 150°C for 8 hours under reduced pressure to obtain polyimide (V) (9.696 g yield: 86.0%).

[Example 2-6]

In a 100 mL three-necked reaction flask equipped with a nitrogen inlet/outlet and a mechanical stirrer, 1.457 g (0.00455 mol) of 2,2'-di(trifluoromethyl)benzidine (TFMB) and 1.019 g (0.00195 mol) of DCTDABA were added. I put it in. 13.13 g of γ-butyrolactone (GBL) was added thereto and stirred to confirm that TFMB and DCTDABA were dissolved.

Again, 0.7285 g (0.00325 mol) of 2,3,5-tricarboxycyclopentylacetic acid-1,4:2,3-dianhydride (TCA) and 2.813 g of γ-butyrolactone (GBL) were added. Then, the obtained mixture was stirred at 90°C for 7 hours under a nitrogen atmosphere,

After the reaction mixture was cooled to 50°C, 0.637 g (0.00325 mol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA) and 2.813 g of GBL were added, and the mixture was stirred overnight under a nitrogen atmosphere. . Afterwards, the reaction mixture was diluted using GBL so that the solid concentration was 10% by mass, and 2.654 g (0.026 mol) of acetic anhydride and 1.542 g (0.0195 mol) of pyridine were added to the diluted reaction mixture, and then incubated at 100°C. It was stirred for 4 hours.

Next, the obtained reaction mixture was added dropwise into 250 g of methanol, stirred for 30 minutes, and the precipitate was recovered by filtration. This operation was repeated three times.

Finally, the obtained residue was dried at 120°C for 8 hours under reduced pressure to obtain polyimide (VI) (3.53 g yield: 92%).

[3] Preparation of polyimide solution (varnish)

[Example 3-1]

Polyimide (I) obtained in Example 2-1 was dissolved in NMP so that the concentration was 12% by mass, and polyimide solution (I) was obtained.

[Example 3-2]

Polyimide solution (II) was prepared in the same manner as in Example 3-1, except that polyimide (II) obtained in Example 2-2 was used instead of polyimide (I) obtained in Example 2-1. got it

[Example 3-3]

Polyimide solution (III) was prepared in the same manner as in Example 3-1, except that polyimide (III) obtained in Example 2-3 was used instead of polyimide (I) obtained in Example 2-1. got it

[Example 3-4]

Polyimide solution (IV) was prepared in the same manner as in Example 3-1, except that polyimide (IV) obtained in Example 2-4 was used instead of polyimide (I) obtained in Example 2-1. got it

[Example 3-5]

The polyimide (V) obtained in Example 2-5 was dissolved in GBL so that the concentration was 12% by mass, and a polyimide solution (V) was obtained.

[Example 3-6]

Polyimide (VI) obtained in Example 2-6 was dissolved in GBL so that the concentration was 12% by mass, and polyimide solution (VI) was obtained.

[4] Production of polyimide film

[Example 4-1]

First, the polyimide solution (I) obtained in Example 3-1 was pressure filtered using a 5 μm filter.

Thereafter, the filtered polyimide solution (I) was applied on a glass substrate under air and heated sequentially at 50°C for 30 minutes, 140°C for 30 minutes, and 200°C for 60 minutes to obtain a polyimide film. Then, a square cut was made in the obtained polyimide membrane, the membrane was peeled off, and it was used as an evaluation sample.

[Example 4-2]

The polyimide was prepared in the same order and method as in Example 4-1, except that the polyimide solution (II) obtained in Example 3-2 was used instead of the polyimide solution (I) obtained in Example 3-1. got the curtain Then, a square cut was made in the obtained polyimide membrane, the membrane was peeled off, and it was used as an evaluation sample.

[Example 4-3]

The polyimide was prepared in the same order and method as in Example 4-1, except that the polyimide solution (III) obtained in Example 3-3 was used instead of the polyimide solution (I) obtained in Example 3-1. got the curtain Then, a square cut was made in the obtained polyimide membrane, the membrane was peeled off, and it was used as an evaluation sample.

[Example 4-4]

The polyimide was prepared in the same order and method as in Example 4-1, except that the polyimide solution (IV) obtained in Example 3-4 was used instead of the polyimide solution (I) obtained in Example 3-1. got the curtain Then, a square cut was made in the obtained polyimide membrane, the membrane was peeled off, and it was used as an evaluation sample.

[Example 4-5]

The polyimide was prepared in the same order and method as in Example 4-1, except that the polyimide solution (V) obtained in Example 3-5 was used instead of the polyimide solution (I) obtained in Example 3-1. got the curtain Then, a square cut was made in the obtained polyimide membrane, the membrane was peeled off, and it was used as an evaluation sample.

[Example 4-6]

The polyimide solution (VI) obtained in Example 3-6 was pressure filtered using a 5 μm filter.

Thereafter, the filtered polyimide solution (VI) was applied onto a glass substrate and heated sequentially under air at 50°C for 30 minutes, 140°C for 30 minutes, and 200°C for 60 minutes to obtain a transparent polyimide film. Then, the obtained polyimide film was peeled off by mechanical cutting and used as an evaluation sample.

[5] Evaluation of polyimide films and membranes

Heat resistance and optical properties of each film (evaluation sample) produced in the above-described order, i.e., coefficient of linear expansion (CTE) at 50°C to 200°C, 5% weight loss temperature (Td _5% ), light transmittance (T _400nm) , T _{550 nm} ) and CIE b ^* value (yellow color evaluation), retardation (R _th , R ₀ ) and refractive index (Δ) were evaluated in the following order. The results are shown in Table 1.

1) Coefficient of Linear Expansion (CTE)

<Example 4-1 to 4-5 samples>

Using TMA Q400 manufactured by TA Instruments, the membrane was cut to a size of 5 mm in width and 16 mm in length, first heated at 10°C/min to 50 to 300°C (first heating), and then lowered at 10°C/min. After cooling to 50°C, the temperature is raised at 10°C/min and heated to 50 to 420°C (second heating). Coefficient of linear expansion (CTE [ppm/°C]) at 50°C to 200°C in the second heating. It was obtained by measuring the value. Meanwhile, a load of 0.05 N was applied through the first heating, cooling, and second heating.

<Example 4-6 Sample>

Each evaluation sample was cut to a size of 5 mm in width and 16 mm in length, and this was first heated at 10° C./min to 50 to 300° C. (first heating) using a TMA Q400 manufactured by TA Instruments, and then heated at 10° C./min. After cooling to 30°C by lowering the temperature at 10°C/min, the temperature is raised at 10°C/min and heated to 30 to 410°C (second heating), at 50°C to 200°C and 200°C to 250°C in the second heating. It was obtained by measuring the value of the coefficient of linear expansion (CTE [ppm/°C]). Meanwhile, a load of 0.05 N was applied through the first heating, cooling, and second heating.

2) 5% weight loss temperature (Td _5% )

<Example 4-1 to 4-5 samples>

The 5% weight loss temperature (Td _5% [°C]) was determined by measuring the temperature of about 5 to 10 mg of the film in nitrogen at 10°C/min to 50 to 800°C using a TGA Q500 manufactured by TA Instruments.

<Example 4-6 Sample>

The 5% weight loss temperature (Td _5% [°C]) was determined by measuring the temperature of about 5 to 10 mg of the film in nitrogen at 10°C/min to 50 to 800°C using a TGA Q500 manufactured by TA Instruments. Meanwhile, the weight at 150°C was set to 0% weight loss.

3) Light transmittance (transparency) (T _400nm , T _550nm ) and CIE b value (CIE b ^* )

<Example 4-1 to 4-5 samples>

Light transmittance (T _{400 nm} , T _{550 nm} [%]) and CIE b value (CIE b ^* ) at wavelengths of 400 nm and 550 nm were measured at room temperature using an SA4000 spectrometer manufactured by Japan Sensei Kogyo Co., Ltd. with air as the reference. , measurements were made.

<Example 4-6 Sample>

The light transmittance (T _{400 nm} , T _{550 nm} [%]) at wavelengths of 400 nm and 550 nm was measured at room temperature using an ultraviolet-visible spectrophotometer UV-Visible 3600 manufactured by Shimadzu Corporation, and with air as the reference. .

The CIE b value (CIE b ^* ) was measured at room temperature using an SA4000 spectrometer manufactured by Nippon Seokjin Kogyo Co., Ltd., with air as the reference.

4) Retardation (R _th , R ₀ )

Thickness direction retardation (R _th ) and in-plane retardation (R ₀ ) were measured at room temperature using KOBURA 2100ADH manufactured by Oji Measuring Equipment Co., Ltd.

On the other hand, the thickness direction retardation (R _th ) and the in-plane retardation (R ₀ ) are calculated with the following equations.

R ₀ =(Nx-Ny)×d=ΔNxy×d

R _th =[(Nx+Ny)/2-Nz]×d=[(ΔNxz×d)+(ΔNyz×d)/2

Nx, Ny: Two orthogonal refractive indices in the plane (Nx>Ny, Nx is also called slow axis and Ny is called fast axis)

Nz: Refractive index in the thickness (perpendicular) direction (perpendicular) to the surface

d: film thickness

ΔNxy: Difference between two refractive indices in a plane (Nx-Ny) (refractive index)

ΔNxz: Difference between the refractive index Nx in the plane and the refractive index Nz in the thickness direction (refractive index)

ΔNyz: Difference between the refractive index Ny in the plane and the refractive index Nz in the thickness direction (refractive index)

5) Film thickness (d)

The film thickness of the obtained film was measured with a thickness meter manufactured by Techrock Co., Ltd.

6) Refractive index (Δn)

Using the value of the thickness direction retardation (R _th ) obtained by <4) retardation> described above, it was calculated using the following equation.

ΔN=[R _th /d (film thickness)]/1000

[Table 1]

As shown in Table 1, the films produced using the diamine of the present invention (Examples 4-1 to 4-5) are very flexible, and in particular, the transmittance (T _{550 nm} ) at a wavelength of 550 nm is approximately The result was as high as 90%. In addition, the in-plane retardation R ₀ of this film was 2.2 nm to 9.8 nm, and the retardation R _th in the thickness direction was also a low value of 440 nm to 1022 nm.

In this way, the film manufactured using the diamine of the present invention has the characteristics of high flexibility, transparency, and low retardation, that is, it satisfies the requirements required as a base film for a flexible display substrate, and is especially useful as a base film for a flexible display substrate. You can expect to be able to use it conveniently.

Claims (17)

A diamine characterized by being represented by formula (1-1).

(Wherein,
Y represents a halogen atom, an alkyl group with 1 to 5 carbon atoms, a haloalkyl group with 1 to 5 carbon atoms, or an alkoxy group with 1 to 5 carbon atoms,
n represents an integer from 0 to 4.) According to paragraph 1,
Diamine, which is a diamine represented by formula (1-2).

(In the formula, X represents an oxygen atom or -NH- group.) According to paragraph 2,
Diamine, which is a diamine represented by formula (1-3).

(In the formula, X represents an oxygen atom or -NH- group.) A polyamic acid obtained by reacting a diamine component containing the diamine according to claim 1 and an acid dianhydride component. According to paragraph 4,
A polyamic acid in which the diamine component further contains diamine represented by formula (A1).

(In the formula, B ² represents a divalent group selected from the group consisting of formulas (Y-1) to (Y-34).)

(In the formula, * represents the number of bonds.) According to paragraph 4,
A polyamic acid in which the acid dianhydride component contains an acid dianhydride represented by formula (C1).

[In the formula, B ¹ represents a tetravalent group selected from the group consisting of formulas (X-1) to (X-12).

(In the formula, a plurality of R independently represents a hydrogen atom or a methyl group, and * represents the number of bonds.)] A composition for forming a polyamic acid-containing film, comprising the polyamic acid according to any one of claims 4 to 6 and an organic solvent. A film formed from the polyamic acid-containing film-forming composition according to claim 7. A substrate for a flexible device comprising a film formed from the polyamic acid-containing film-forming composition according to claim 7. A polyimide obtained by imidizing the polyamic acid according to any one of claims 4 to 6. A composition for forming a film comprising the polyimide according to claim 10 and an organic solvent. A film formed from the film-forming composition according to claim 11. A substrate for a flexible device consisting of a film formed from the film-forming composition according to claim 11. A dinitro compound characterized by being represented by formula (2-1).

(Wherein,
Y represents a halogen atom, an alkyl group with 1 to 5 carbon atoms, a haloalkyl group with 1 to 5 carbon atoms, or an alkoxy group with 1 to 5 carbon atoms,
n represents an integer from 0 to 4.) According to clause 14,
A dinitro compound, which is a dinitro compound represented by formula (2-2).

(In the formula, X represents an oxygen atom or -NH- group.) According to clause 15,
A dinitro compound, which is a dinitro compound represented by formula (2-3).

(In the formula, X represents an oxygen atom or -NH- group.) As a method for producing diamine represented by formula (1-1),

(Wherein,
Y represents a halogen atom, an alkyl group with 1 to 5 carbon atoms, a haloalkyl group with 1 to 5 carbon atoms, or an alkoxy group with 1 to 5 carbon atoms,
n represents an integer from 0 to 4.)
A production method comprising the step of reducing the nitro group of the dinitro compound represented by Formula (2-1) to obtain a diamine represented by Formula (1-1).

(In the formula, X, Y and n have the same meaning as above.)