TWI684580B - Diamine and use thereof - Google Patents

Abstract

Provided is a novel diamine that can impart not only excellent flexibility and transparency, but also low so-called retardation.

(式中，R₁至R₅係分別獨立表示鹵素原子、烷基或烷氧基，R₆及R₇係分別獨立表示氫原子、鹵素原子、烷基或烷氧基，a、b、d及e係分別獨立表示0~4之整數，然後c係表示0~2之整數)。 A diamine characterized by the formula (1-1); the polyamic acid and polyimide obtained from the diamine; and, for forming a thin film containing the polyimide and silicon dioxide particles The composition and the film formed therefrom,

(In the formula, R ₁ to R ₅ independently represent a halogen atom, alkyl group or alkoxy group, R ₆ and R ₇ independently represent a hydrogen atom, halogen atom, alkyl group or alkoxy group, a, b, d And e independently represent integers from 0 to 4, and then c represents integers from 0 to 2.)

Description

Diamine and its utilization

The present invention relates to diamine and its utilization.

In recent years, with the rapid progress of electronic components such as liquid crystal displays and organic electroluminescence displays, there has been a demand for thinner or lighter devices, and further flexibility.

In these devices, various electronic components such as thin film transistors or transparent electrodes are formed on a glass substrate, but by replacing the glass material with a soft and lightweight resin material, the device itself can be expected Thinner or lighter and flexible.

Then, as a candidate for such a resin material, polyimide has attracted much attention, and there have been various reports on polyimide films in the past (refer to, for example, Patent Documents 1 and 2).

[Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Unexamined Patent Publication No. 60-188427

[Patent Document 2] Japanese Unexamined Patent Publication No. 58-208322

[Patent Document 3] International Publication No. 2011/149018 Specification

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

That is, the so-called retardation (phase difference) refers to the product of birefringence (the difference between two orthogonal refractive indexes) and the film thickness, but this value, especially the retardation in the thickness direction, is an important value that affects the viewing angle characteristics. The delay value may cause the display quality of the display to deteriorate (refer to, for example, Patent Document 3). Therefore, even a flexible display substrate requires such characteristics in addition to high flexibility (flexibility).

The present invention is an invention in view of such circumstances, and an object of the present invention is to provide a diamine that can impart not only excellent flexibility and transparency, but also a film with a characteristic of so-called low retardation.

The present inventors have made repeated and intensive studies to solve the above-mentioned problems and found that by combining the diamine compound represented by the following formula (1-1) with 2,2′-bis(trifluoromethyl)benzidine, etc. The aromatic diamine containing fluorine atom is copolymerized with alicyclic tetracarboxylic dianhydride such as tetracyclobutyric dianhydride Together, a polyimide soluble in an organic solvent can be obtained, and a composition obtained by dissolving the polyimide in an organic solvent can be obtained from the composition not only in flexibility and transparency, but also The film also has a feature that the retardation is low, and the present invention has been completed.

(式中，R₁、R₂、R₃、R₄及R₅係分別獨立表示鹵素原子、碳原子數1至5之烷基或碳原子數1至5之烷氧基，R₆及R₇係分別獨立表示氫原子、鹵素原子、碳原子數1至5之烷基或碳原子數1至5之烷氧基，a、b、d及e係分別獨立表示0~4之整數，然後c係表示0~2之整數)。 That is, the first aspect of the present invention relates to a diamine whose characteristic is represented by formula (1-1),

(In the formula, R ₁ , R ₂ , R ₃ , R ₄ and R ₅ each independently represent a halogen atom, an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms, R ₆ and R ₇ represents independently hydrogen atom, halogen atom, alkyl group having 1 to 5 carbon atoms or alkoxy group having 1 to 5 carbon atoms, a, b, d and e independently represent integers of 0 to 4, and c is an integer from 0 to 2).

The second viewpoint is the diamine described in the first viewpoint, which is the diamine represented by the formula (1-2),

The third aspect is the diamine described in the second aspect, which is a diamine represented by formula (1-3) or formula (1-4),

The fourth aspect relates to a polyamic acid, which is a reaction product of a diamine component and an acid dianhydride component, and the diamine component includes the diamine described in any one of the first aspect to the third aspect.

The fifth aspect is the polyamic acid described in the fourth aspect, wherein the diamine component further includes the diamine represented by the formula (A1), [Chem. 4] H ₂ NB ² -NH ₂ (A1) ( In the formula, B ² represents a divalent group selected from the group consisting of formulas (Y-1) to (Y-34)),

(式中，＊係表示鍵結鍵)。

(In the formula, * means a bond).

[式中，B¹係表示選自由式(X-1)~(X-12)所成之群之4價基，

(式中，複數的R係相互獨立表示氫原子或甲基，＊係表示鍵結鍵)]。 The sixth aspect is the polyamic acid described in the fourth aspect or the fifth aspect, wherein the acid dianhydride component includes the acid dianhydride represented by the formula (C1),

[In the formula, B ¹ represents a 4-valent group selected from the group consisting of formulas (X-1) to (X-12),

(In the formula, plural R systems independently represent a hydrogen atom or a methyl group, and * systems represent a bonding bond)].

The seventh aspect relates to a polyimide which is obtained by imidizing the polyimide acid described in any one of the fourth to sixth points.

The eighth aspect is a composition for forming a thin film, which includes the polyimide described in the seventh aspect, an organic solvent, and silicon dioxide particles having a specific surface area measured by a nitrogen adsorption method The average particle diameter calculated from the value is 100 nm or less.

The ninth aspect is the composition for thin film formation described in the eighth aspect, wherein the mass ratio of the polyimide to the silicon dioxide particles is 1:10 to 10:1.

As the tenth point of view, it is about the eighth point or the ninth point. In the composition for film formation, the average particle diameter is 60 nm or less.

The eleventh point is about a thin film formed from the thin film forming composition described in any one of the eighth point to the tenth point.

The twelfth aspect is a substrate for a flexible device, which is formed from the thin film described in the eleventh aspect.

The thirteenth aspect is a composition for film formation, which contains the polyimide described in the seventh aspect and an organic solvent.

The fourteenth aspect relates to a flexible device substrate, which is formed of a film formed from the film-forming composition described in the thirteenth aspect.

(式中，R₁、R₂、R₃、R₄及R₅係分別獨立表示鹵素原子、碳原子數1至5之烷基或碳原子數1至5之烷氧基，R₆及R₇係分別獨立表示氫原子、鹵素原子、碳原子數1至5之烷基或碳原子數1至5之烷氧基，a、b、d及e係分別獨立表示0~4之整數，然後c係表示0~2之整數)。 As the fifteenth point of view, a dinitro compound is characterized by the formula (2-1),

(In the formula, R ₁ , R ₂ , R ₃ , R ₄ and R ₅ each independently represent a halogen atom, an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms, R ₆ and R ₇ represents independently hydrogen atom, halogen atom, alkyl group having 1 to 5 carbon atoms or alkoxy group having 1 to 5 carbon atoms, a, b, d and e independently represent integers of 0 to 4, and c is an integer from 0 to 2).

The 16th viewpoint is the dinitro compound described in the 15th viewpoint, which is a dinitro compound represented by the formula (2-2),

As the 17th viewpoint, the dinitro compound described in the 16th viewpoint is a dinitro compound represented by formula (2-3) or formula (2-4),

(式中，R₁、R₂、R₃、R₄及R₅係分別獨立表示鹵素原子、碳原子數1至5之烷基或碳原子數1至5之烷氧基，R₆及R₇係分別獨立表示氫原子、鹵素原子、碳原子數1至5之烷基或碳原子數1至5之烷氧基，a、b、d及e係分別獨立表示0~4之整數，然後c係表示0~2之整數)，

(式中，R₁、R₂、R₃、R₄、R₅、R₆、R₇、a、b、c、d及e係表示與上述相同之意思)。 The eighteenth point is about a manufacturing method which is a method for manufacturing the diamine represented by the formula (1-1), which includes reducing the nitro group of the dinitro compound represented by the formula (2-1) to obtain the formula ( 1-1) The stage of the diamine indicated,

(In the formula, R ₁ , R ₂ , R ₃ , R ₄ and R ₅ each independently represent a halogen atom, an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms, R ₆ and R ₇ represents independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms, and a, b, d, and e independently represent integers of 0 to 4, and c is an integer from 0 to 2),

(In the formula, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , a, b, c, d, and e represent the same meaning as described above).

The novel diamine compound of the present invention can be obtained by dissolving an organic solvent-soluble polyacrylic acid by co-polymerizing a conventionally known fluorine atom-containing aromatic diamine with an alicyclic tetracarboxylic dianhydride Imine.

In addition, the polyimide obtained from the diamine compound of the present invention can form a thin film having excellent flexibility and transparency, and can further realize low retardation.

Furthermore, the film obtained by the film-forming composition containing the polyimide of the present invention exhibits low linear expansion coefficient and low retardation in addition to being excellent in flexibility and transparency, and therefore the resin The film can also be suitably used as a substrate for flexible devices, especially flexible displays.

Then, the film formed using the polyimide of the present invention can exhibit high transparency (high light transmittance, low yellowness) and low retardation, so it can be suitably used as a flexible device, especially Use for flexible display substrates.

[Best form for carrying out the invention] [Diamine compound]

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

The diamine related to the present invention is a diamine represented by formula (1-1), and particularly preferably a diamine represented by formula (1-2). Among them, considering flexibility and transparency, it is excellent, When a low-retardation film with good reproducibility and the like can be obtained, the diamine represented by formula (1-3) or formula (1-4) is preferred.

(上述式(1-1)中，R₁、R₂、R₃、R₄及R₅係分別獨立表示鹵素原子、碳原子數1至5之烷基或碳原子數1至5之烷氧基，R₆及R₇係分別獨立表示氫原子、鹵素原子、碳原子數1至5之烷基或碳原子數1至5之烷氧基，a、b、d及e係分別獨立表示0~4之整數，然後c係表示0~2之整數)。

(In the above formula (1-1), R ₁ , R ₂ , R ₃ , R ₄ and R ₅ each independently represent a halogen atom, an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms Group, R ₆ and R ₇ independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms, and a, b, d, and e independently represent 0 ~4 integer, then c is an integer of 0~2).

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 and ethyl Group, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, sec- Isoamyl, cyclopentyl, n-hexyl, etc.

In addition, examples of the alkoxy group having 1 to 5 carbon atoms include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, and sec-butoxy. Group, tert-butoxy, n-pentyloxy, isopentyloxy, neopentyloxy, tert-pentyloxy, etc.

The diamines represented by the above formulas (1-1) to (1-4) of the present invention can respectively reduce the nitro group of the dinitro compounds represented by the following formulas (2-1) to (2-4) And get.

(式中，R₁、R₂、R₃、R₄、R₅、R₆、R₇、a、b、c、d及e係表示與上述相同之意思)。

(In the formula, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , a, b, c, d, and e represent the same meaning as described above).

Specifically, the diamine represented by the above formula (1-1) is represented as, for example, in the following flow chart. In an organic solvent, in the presence of an alkali catalyst, 9,10-[1,2] Benzoanthracene-1,4-diol compound (hereinafter, also called benzoanthracenediol compound) reacts with nitrobenzoyl halide compound and Intermediate (9,10-[1,2]benzoanthracene-1,4-diyl bis(nitrobenzoate) compound) (compound represented by formula (2-1)) (stage 1 ), which can be obtained by reducing the nitro group of the intermediate (stage 2). Still, the dinitro compound represented by the above formulas (2-1) to (2-4) of the intermediate is also the object of the present invention.

(上述流程圖中，X係表示鹵素原子，R₁、R₂、R₃、R₄、R₅、R₆、R₇、a、b、c、d及e係表示與上述相同之意思)。

(In the above flowchart, X represents a halogen atom, and R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , a, b, c, d, and e represent the same meaning as above) .

In the reaction in the first stage, the charging ratio of the benzoanthracene diol compound to the nitrobenzoyl halide compound is 1 to 2 moles of the benzoanthracene diol compound, and the nitrobenzoyl halide compound 2~ 4 molar is better. In addition, since the nitrobenzyl halide compound has low stability in the reaction solution, it is not necessary to add the amount at one time, but it is preferable to add it in batches several times.

As an alkaline catalyst, trimethylamine, triethylamine, diisopropylamine, diisopropylethylamine, N-methylpiperidine, 2,2,6,6-tetramethyl can be suitably used Organic bases such as organic amines such as N-methylpiperidine, pyridine, 4-dimethylaminopyridine, N-methylmorpholine, etc. In addition, the amount of the alkali catalyst used is not particularly limited as long as it is 2 moles or more relative to 1 mole of the benzoanthracene compound, but it is usually about 2 to 10 moles.

In addition, in order to neutralize the acid such as hydrochloric acid which is a by-product generated in the reaction, an acid absorbent may also be used. Examples of the acid absorbent include epoxides such as propylene oxide. The use amount of the acid absorbent is not particularly limited as long as it is 2 moles or more with respect to 1 mole of the benzoanthracene compound, but it is usually about 2 to 10 moles.

The organic solvent is not particularly limited as long as it does not affect the reaction, and aromatic hydrocarbons such as benzene, toluene, and xylene can be used; N,N-dimethylformamide (hereinafter referred to as DMF) ), N,N-dimethylacetamide (hereinafter referred to as DMAc), N-methyl-2-pyrrolidone (hereinafter referred to as NMP) and other amides; diethyl ether, tetrahydrofuran, 1, Ethers such as 4-dioxane, 1,2-dimethoxyethane, cyclopentyl methyl ether, ketones such as 2-butanone, 4-methyl-2-pentanone, and nitriles such as acetonitrile Class, dimethyl sulfoxide (hereinafter referred to as DMSO) and so on. These solvent systems may be used alone or in combination of two or more. In addition, if the solvent contains too much water, the hydrolysis of the ester will be caused, so it is preferable to use a dehydration solvent or use it after dehydration.

The reaction temperature can be set to about 0 to 200°C, but preferably 20 to 150°C.

After the reaction, the solvent is distilled off, and the crude product can be used directly or after purification for subsequent steps. The purification method is arbitrary, and may be appropriately selected from well-known methods such as recrystallization, distillation, and silica gel column chromatography.

In the reaction in the second stage, as a method for reducing the nitro group of the intermediate to the amine group, there is no particular limitation as long as a well-known method is used, for example, palladium-carbon, platinum oxide, Raney nickel, platinum-carbon , Rhodium-aluminum, sulfide Platinum carbon, reduced iron, iron chloride, tin, tin chloride, zinc, etc. are used as catalysts, and are carried out by hydrogen, hydrazine, hydrogen chloride, ammonium chloride, etc. In particular, it is difficult to cause a side reaction caused by the ester part of the intermediate, and the target can be easily obtained, so contact hydrogenation is preferable.

As a source of hydrogen atoms in contact with hydrogenation, hydrogen, hydrazine, hydrogen chloride, ammonium chloride, ammonium formate, etc. may be mentioned.

Examples of the catalyst used in the contact hydrogenation include powders of metals such as platinum, palladium, ruthenium, rhodium, nickel, iron, zinc, and tin, and powders of metals may be supported on the active body. The type of catalyst is not particularly limited because it is appropriately determined according to the type of hydrogen source or the reaction conditions, but it is only required as long as the catalyst can reduce the nitro group, preferably palladium-carbon, platinum oxide, thunder Nickel, platinum-carbon, rhodium-aluminum, platinum sulfide carbon. In addition, the amount of catalyst used is appropriately determined according to the type of hydrogen source or the reaction conditions, so it is not particularly limited. It is usually 0.01 mol% in terms of metal relative to the dinitro body (intermediate) of the raw material. To 50 mol%, preferably 0.1 mol% to 20 mol%.

As the reaction solvent, a solvent that does not affect the reaction can be used. Examples thereof include 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. -Ether solvents such as dimethoxyethane, tetrahydrofuran and dioxane, alcohol solvents such as methanol and ethanol, ketone solvents such as 2-butanone and 4-methyl-2-pentanone, N,N -Aprotic polar solvents such as dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, dimethylsulfoxide, water, etc. These solvents can be used alone or in combination of two or more use.

As long as no raw materials or products are decomposed, and below the boiling point of the solvent used, the reaction temperature is carried out at a temperature at which the reaction can proceed efficiently. Specifically, a temperature of -78°C to the boiling point of the solvent or lower is preferable, and from the viewpoint of simplicity of synthesis, a temperature of 0°C to the boiling point of the solvent or lower is still more preferable, and more preferably 0 to 100 °C, and further preferably 10 to 50°C.

In addition, the contact hydrogenation system can also be carried out using an autoclave under pressurized conditions.

After the reaction, the solvent is distilled off, and the diamine which can obtain the target substance is purified using well-known methods such as recrystallization, distillation, and silica gel column chromatography. In addition, if there is too much oxygen in the solvent, it may cause coloration of the generated diamine compound. Therefore, the solvent used in the reaction and purification is preferably degassed. In addition, in order to further prevent coloration, it is also preferable to degas the reaction liquid before the solvent distillation after the reaction and after the solvent distillation.

In addition, the benzoanthracenediol compound used in the present invention is, for example, as shown in the following flowchart, according to a well-known method, an anthracene compound and a 1,4-benzoquinone compound are subjected to Diels- in an organic solvent. Alder reaction to obtain 9,10-[1,2]benzoanthracene-13,16(9H,10H)-diketone compound, the obtained compound in acetic acid solvent in the presence of 47% hydrogen bromide, by Available under heating conditions.

(上述流程圖中，X係表示鹵素原子，R₁、R₂、R₃、R₄、R₅、R₆、R₇、a、b、c、d及e係表示與上述相同之意思)。

(In the above flowchart, X represents a halogen atom, and R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , a, b, c, d, and e represent the same meaning as above) .

[Polyamide and polyimide]

The above-described diamine of the present invention is produced by polycondensation reaction with acid dianhydride to form polyamic acid, and can be converted into corresponding polyimide by heat or dehydration ring-closure reaction using a catalyst . The polyamic acid and the polyimide are the object of the present invention.

From the viewpoint of obtaining reproducibly good polyamic acid and polyimide which are not only excellent in flexibility and transparency, but also have low retardation characteristics, the polyamic acid of the present invention The diamine component used in the production is preferably an aromatic diamine containing a fluorine atom in addition to the diamine represented by the above formula (1-1) of the present invention, and further preferably contains the following formula (A1) The diamine represented.

[Chem. 21] H ₂ NB ² -NH ₂ (A1) (wherein, B ² represents a divalent group selected from the group consisting of formulas (Y-1) to (Y-34))

(式中，＊係表示鍵結鍵)。

(In the formula, * means a bond).

In the diamine represented by the above formula (A1), B ² in the formula is represented by the aforementioned formulas (Y-12), (Y-13), (Y-14), (Y-15), (Y-18), The diamine represented by (Y-27), (Y-28), (Y-30), (Y-33) is preferred, and the aforementioned B ^{2 is} represented by the aforementioned formulas (Y-12), (Y-13), The diamines represented by (Y-14), (Y-15) and (Y-33) are particularly preferred.

In addition, as long as the effect of the present invention is not impaired, other diamines than the diamine represented by the above formula (1-1) and the diamine represented by the above formula (A1) may be used as the diamine component. Amine compounds.

When the aromatic diamine containing a fluorine atom is used together with the diamine represented by the above formula (1-1) of the present invention in the above diamine component, the diamine represented by the above formula (1-1) and the fluorine-containing The molar ratio between the atomic aromatic diamines is usually the diamine represented by the above formula (1-1): fluorine atom-containing aromatic diamine = 1:1 to 1:10. By setting to such a range, the fragility of the film can be suppressed, and a thin film with a low linear expansion coefficient can be obtained with good reproducibility membrane.

From the viewpoint of obtaining reproducibly good polyamic acid and polyimide which are not only excellent in flexibility and transparency, but also have low retardation characteristics, the polyamic acid of the present invention The acid dianhydride component used in production preferably contains an alicyclic tetracarboxylic dianhydride, and more preferably contains an acid dianhydride represented by the following formula (C1).

[式中，B¹係表示選自由式(X-1)~(X-12)所成之群之4價基，

(式中，複數的R係相互獨立表示氫原子或甲基、＊係表示鍵結鍵)]。

[In the formula, B ¹ represents a 4-valent group selected from the group consisting of formulas (X-1) to (X-12),

(In the formula, plural R systems independently represent a hydrogen atom or a methyl group, and * systems represent a bonding bond)].

In the acid dianhydride represented by the above formula (C1), B ¹ in the formula is represented by the aforementioned formulas (X-1), (X-2), (X-4), (X-5), (X-6) , (X-7), (X-8), (X-9), (X-11), (X-12) represented by acid dianhydride is preferred, the above B ^{1 is} based on the above formula (X-1 ), (X-2), (X-6), (X-11), and (X-12) are particularly preferred.

From the viewpoint of obtaining reproducibly good polyamic acid and polyimide that impart high flexibility, high transparency, and low retardation film, the acid diacid used in the production of the polyamic acid of the present invention The content of the alicyclic tetracarboxylic dianhydride in the anhydride component is preferably 50 mol% or more, more preferably 60 mol% or more, more preferably 70 mol% or more, and still more preferably 80 mol% or more , And more preferably 90 mol% or more, and most preferably 100 mol%.

Still, if the diamine represented by the above formula (1-1) and the diamine represented by the above formula (A1) are used, as the acid dianhydride component, the acid represented by the above (C1) is used In the case of a dianhydride, the polyamic acid will be a monomer unit represented by the following formula (4-1) and a monomer unit represented by the following formula (4-2).

(式中，R₁、R₂、R₃、R₄、R₅、R₆、R₇、a、b、c、d、e、B¹及B²係與上述表示相同意思)。

(In the formula, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , a, b, c, d, e, B ¹ and B ^{2 have} the same meaning as described above).

The method for obtaining the polyamic acid of the present invention is not particularly limited, as long as the aforementioned acid dianhydride component and diamine component are reacted and polymerized by a well-known method.

The ratio of the number of moles of acid dianhydride component to the number of moles of diamine component when synthesizing polyamide is acid dianhydride component/diamine component=0.8~1.2.

Examples of the solvent used in the synthesis of polyamic acid include m-cresol, N-methyl-2-pyrrolidone (NMP), N,N-dimethylformamide (DMF), and N, N-dimethylacetamide (DMAc), N-methylcaprolactam, dimethyl sulfoxide (DMSO), tetramethylurea, pyridine, dimethyl sulfoxide, hexamethylphosphoramide, γ -Butyrolactone, etc. These systems can be used alone or in combination. Furthermore, even if it is a solvent that cannot dissolve the polyamic acid, a solvent other than the above-mentioned solvents can be used as long as a uniform solution can be obtained.

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

The polyamic acid solution obtained by the above-mentioned polymerization reaction of polyamic acid can be used directly, or after dilution or concentration, and used as a film-forming composition for forming a film of polyimide described later. In addition, after adding a weak solvent such as methanol and ethanol to the polyamic acid, the polyimide is precipitated and the polyamic acid is isolated, and the isolated polyamic acid is redissolved in an appropriate solvent. This is used as a composition for film formation described later.

The solvent for redissolution is not particularly limited as long as it can dissolve the obtained polyamic acid, and examples thereof include m-cresol, 2-pyrrolidone, NMP, and N-ethyl-2-pyrrolidine. Ketone, N-vinyl-2-pyrrolidone, DMAc, DMF, γ-butyrolactone, etc.

In addition, even if it is a solvent that cannot dissolve the polyamic acid alone, as long as the polyamic acid is not precipitated, the above solvent can be used Outside the solvent. As this specific example, 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-2-acetate, dipropylene glycol, 2-(2-ethoxypropoxy) propanol, methyl lactate, Ethyl lactate, n-propyl lactate, n-butyl lactate, isoamyl lactate, etc.

The polyimide of the present invention can be obtained by chemically ring-closing the above-described polyamic acid by heat-dehydration ring-closing (thermo-imidization) or using a well-known dehydration ring-closure catalyst.

The heating method is 100 to 300°C, preferably 120 to 250°C.

The method of chemical ring closure can be carried out, for example, in the presence of pyridine, triethylamine, 1-ethylpiperidine, etc., and acetic anhydride, etc. At this time, the temperature can be selected at any temperature from -20 to 200°C .

A polyimide obtained from a polyamic acid having the monomer unit represented by the above formula (4-1) and the monomer unit represented by the above formula (4-2) obtained in this way, It has a monomer unit represented by the following formula (5-1) and a monomer unit represented by the following formula (5-2).

(式中，R₁、R₂、R₃、R₄、R₅、R₆、R₇、a、b、c、d、e、B¹及B²係與上述表示相同意思)。

(In the formula, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , a, b, c, d, e, B ¹ and B ^{2 have} the same meaning as described above).

The polyimide solution obtained by the ring-closing reaction of the above-mentioned polyamic acid can be used directly, or after dilution or concentration, as a composition for film formation described later. After adding a weak solvent such as methanol and ethanol to the polyimide solution, the polyimide is precipitated and the polyimide is isolated, and the isolated polyimide is re-dissolved in an appropriate solvent. This is used as a composition for film formation described later. In addition, these film-forming compositions can be used in the preparation of a film-forming composition containing polyimide and silicon dioxide particles described later.

The solvent for redissolution is not particularly limited as long as it can dissolve the obtained polyimide, and examples thereof include m-cresol, 2-pyrrolidone, NMP, and N-ethyl-2-pyrrolidine. Ketone, N-vinyl-2-pyrrolidone, DMAc, DMF, γ-butyrolactone, etc.

Moreover, even if it is a solvent which cannot dissolve polyimide alone, as long as it does not precipitate polyimide, a solvent other than the above-mentioned solvents can be used. As this specific example, ethyl cellosolve, butyl cellosolve can be exemplified Agent, 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-2-acetate, dipropylene glycol, 2-(2-ethoxypropoxy) propanol, methyl lactate, ethyl lactate, n-propyl lactate, n-butyl lactate , Isoamyl lactate, etc.

In the present invention, the number average molecular weight of the polyamic acid (polyimide) is preferably 5,000 or more, and more preferably 10,000 or more from the viewpoint of improving the flexibility and strength of the obtained film. It is still more preferably 15,000 or more, more preferably 20,000 or more. From the viewpoint of ensuring the solubility of the obtained polyimide, it is preferably 200,000 or less, more preferably 100,000 or less, and still more preferably 50,000 the following. In the present specification, the number average molecular weight is measured by a GPC (gel permeation chromatography) device, and is calculated as a conversion value of polyethylene glycol and polyethylene oxide.

[Composition for film formation]

A composition for forming a thin film including the above-mentioned polyimide of the present invention, an organic solvent, and silica particles is also an object of the present invention.

<silica>

The silica (silica) used in the present invention is not particularly limited, but the silica in the form of particles, for example, has an average particle diameter of 100 nm or less, For example, 5 nm to 100 nm, preferably 5 nm to 60 nm, and more preferably 5 nm to 55 nm, from the viewpoint of obtaining a more transparent film with good reproducibility, preferably 5 nm to 50 nm, and more preferably 5 nm ~45nm, preferably 5nm~35nm, more preferably 5nm~30nm.

In the present invention, the average particle diameter of silicon dioxide particles refers to an average particle diameter value calculated from a specific surface area value measured by a nitrogen adsorption method using silicon dioxide particles.

In particular, in the present invention, colloidal silica having the value of the above average particle diameter can be used, and silica sol can be used as the colloidal silica. As the silica sol, an aqueous silica sol produced by a well-known method using a sodium silicate aqueous solution as a raw material, and an organic silica obtained by substituting water of a dispersion medium of the aqueous silica sol with an organic solvent can be used Stone sol.

Alternatively, an alkoxysilane such as methyl silicate or ethyl silicate may be used in an organic solvent such as alcohol with an alkali catalyst such as ammonia, organic amine compound, sodium hydroxide, etc. The silica sol obtained by hydrolyzing and condensing in the presence of a medium), or an organic silica sol in which the silica sol is replaced with a solvent to another organic solvent.

Among them, the present invention is preferably an organic silica sol using a dispersion medium as an organic solvent.

As an example of the organic solvent in the above-mentioned organosilica sol, lower alcohols such as methanol, ethanol, isopropanol, etc.; N,N-dimethylformamide, N,N-dimethylacetamide Linear amides such as N-methyl-2-pyrrolidone; ethers such as γ-butyrolactone; alcohols such as ethyl cellosolve, ethylene glycol, etc. Acetonitrile, etc. The substitution can be by distillation Method, ultrafiltration method and the like.

The viscosity of the above organosilica sol is about 20℃, 0.6mPa‧s~100mPa‧s.

Examples of commercially available products of the above-mentioned organosilica sol include, for example, the trade name MA-ST-S (methanol-dispersed silica sol, manufactured by Nissan Chemical Industry Co., Ltd.) and the trade name MT-ST (methanol-dispersed silica sol , Nissan Chemical Industry Co., Ltd.), trade name MA-ST-UP (methanol-dispersed silica sol, Nissan Chemical Industry Co., Ltd.), trade name MA-ST-M (methanol-dispersed silica sol, Nissan Chemical Industry) (Stock)), trade name MA-ST-L (methanol-dispersed silica sol, Nissan Chemical Industry Co., Ltd.), trade name IPA-ST-S (isopropyl alcohol-dispersed silica sol, Nissan Chemical Industry (share) )), trade name IPA-ST (isopropyl alcohol-dispersed silica sol, manufactured by Nissan Chemical Industry Co., Ltd.), trade name IPA-ST-UP (isopropyl alcohol-dispersed silica sol, manufactured by Nissan Chemical Industry Co., Ltd.) ), trade name IPA-ST-L (isopropyl alcohol-dispersed silica sol, manufactured by Nissan Chemical Industry Co., Ltd.), trade name IPA-ST-ZL (isopropanol-dispersed silica sol, manufactured by Nissan Chemical Industry (stock)) ), trade name NPC-ST-30 (n-propyl cellosolve-dispersed silica sol, manufactured by Nissan Chemical Industry Co., Ltd.), trade name PGM-ST (1-methoxy-2-propanol-dispersed silica Sol, Nissan Chemical Industry Co., Ltd.), trade name DMAC-ST (dimethylacetamide-dispersed silica sol, Nissan Chemical Industry Co., Ltd.), trade name XBA-ST (xylene‧n-butanol Mixed solvent dispersed silica sol, manufactured by Nissan Chemical Industry Co., Ltd., trade name EAC-ST (ethyl acetate dispersed silica sol, manufactured by Nissan Chemical Industry Co., Ltd.), trade name PMA-ST (propanediol monomethyl ether) Acetate disperse silica Sol, Nissan Chemical Industry Co., Ltd.), trade name MEK-ST (methyl ethyl ketone dispersion silica sol, Nissan Chemical Industry Co., Ltd.), trade name MEK-ST-UP (methyl ethyl ketone dispersion) Silica sol, Nissan Chemical Industry Co., Ltd.), trade name MEK-ST-L (methyl ethyl ketone dispersed silica sol, Nissan Chemical Industry Co., Ltd.), and trade name MIBK-ST (methyl isobutyl) Ketone-dispersed silica sol, Nissan Chemical Industry Co., Ltd., etc., but not limited to these.

The silica in the present invention can be used as an organic silica sol, for example, the silica series mentioned above as the above-mentioned products can also be used by mixing two or more kinds.

<organic solvent>

The composition for forming a thin film of the present invention contains an organic solvent in addition to the aforementioned polyimide and silicon dioxide. The organic solvent is not particularly limited, and examples thereof include the same as the specific examples of the reaction solvent used in the preparation of the above-mentioned polyamic acid and polyimide. More specifically, N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2- Imidazolinone, N-ethyl-2-pyrrolidone, γ-butyrolactone, etc. Still, the organic solvent system may be used alone or in combination of two or more.

Among these, when it is considered that a thin film with high flatness can be obtained with good reproducibility, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, and γ-butyrolactone are preferred. good.

<Composition for film formation>

The present invention is a film-forming composition containing the aforementioned polyimide, silicon dioxide, and an organic solvent. Here, the composition for thin film formation of the present invention is uniform, and phase separation cannot be observed.

In the composition for forming a thin film of the present invention, the blending ratio of the polyimide and the silicon dioxide is preferably of a good quality: polyimide: silicon dioxide=10:1~1:10, preferably 8:2~2:8, for example, 7:3~3:7.

In addition, in the composition for forming a thin film of the present invention, the amount of the solid content is usually about 0.5 to 30% by mass, preferably about 5 to 25% by mass. If the solid content concentration is less than 0.5% by mass, the film-forming efficiency during film formation will be low, and the viscosity of the film-forming composition will be low, making it difficult to obtain a uniform coating film on the surface. If the solid content concentration exceeds 30% by mass, the viscosity of the film-forming composition becomes too high, which may result in deterioration of film-forming efficiency or insufficient surface uniformity of the coating film. In addition, the solid content here means the total mass of components other than the organic solvent, and even the liquid monomer and the like are included in the weight as the solid content.

In addition, the viscosity of the film-forming composition can be appropriately set according to the thickness of the film to be produced, etc. In particular, if the purpose is to obtain a film with a thickness of about 5 to 50 μm with good reproducibility, usually It is about 500~50,000mPa‧s at 25°C, preferably about 1,000~20,000mPa‧s.

In order to impart processing characteristics or various functionalities to the composition for film formation of the present invention, various other Organic or inorganic low molecular or high molecular compounds. For example, catalysts, defoamers, leveling agents, surfactants, dyes, plasticizers, microparticles, coupling agents, sensitizers, etc. can be used. For example, the catalyst system can be added for the purpose of reducing the retardation or linear expansion coefficient of the film. In addition, in addition to the aforementioned polyimide, silicon dioxide, and an organic solvent, even a composition for forming a thin film containing a catalyst may also be an object of the present invention.

The composition for forming a thin film of the present invention can be obtained by dissolving the polyimide and silicon dioxide obtained by the above method in the above organic solvent, and adding it to the prepared reaction solution of polyimide Silicon dioxide may be further added with the aforementioned organic solvent as desired.

[film]

The thin film forming composition of the present invention described above is coated on a substrate, and the organic solvent is removed by drying and heating to obtain high heat resistance, high transparency, appropriate flexibility, and appropriate linear expansion Coefficient, and retardation is a small film.

In addition, the thin film, that is, the thin film containing the polyimide and the inorganic silica compound is also an object of the present invention.

Examples of the substrate used in the production of films include plastics (polycarbonate, polymethacrylate, polystyrene, polyester, polyolefin, epoxy, melamine, cellulose triacetate, ABS, AS, (Norbornene-based resin, etc.), metal, stainless steel (SUS), wood, paper, glass, silicon wafer, slate, etc.

Especially when it is used as a substrate material for electronic devices, From the standpoint of using existing equipment, glass and silicon wafers are the preferred substrates, and glass is more preferable in terms of the resulting film exhibiting good peelability. Still, as the linear expansion coefficient of the applicable substrate, from the viewpoint of substrate warpage after coating, it is preferably 35 ppm/°C or less, more preferably 30 ppm/°C or less, and still more preferably 25 ppm/ Below ℃, more preferably 20 ppm/℃ or less.

The coating method of the substrate film-forming composition is not particularly limited, but examples thereof include a casting method, spin coating method, blade coating method, dip coating method, roll coating method, bar coating method, die coating method, and inkjet Method, printing method (relief, intaglio, lithography, screen printing, etc.), etc., can be appropriately used according to the purpose.

The heating temperature is preferably 300°C or lower. If the temperature exceeds 300°C, the resulting thin film becomes brittle, so in particular, a thin film suitable for display substrate applications may not be obtained.

In addition, when considering the heat resistance and linear expansion coefficient characteristics of the obtained film, after heating the coated film-forming composition at 40°C to 100°C for 5 minutes to 2 hours, the heating temperature is directly increased stepwise. Finally, it is better to heat at 175℃~280℃ for 30 minutes~2 hours. In this way, by heating at a temperature of two or more stages of the stage of drying the solvent and the stage of promoting molecular alignment, low thermal expansion characteristics can be exhibited.

In particular, the coated film forming composition is heated at 40°C to 100°C for 5 minutes to 2 hours, then heated at more than 100°C to 175°C for 5 minutes to 2 hours, and then heated at more than 175°C to 280°C It is better to perform for 5 minutes to 2 hours.

Examples of the appliance used for heating include a hot plate and an oven. The heating atmosphere may be under air or an inert gas such as nitrogen, or under normal pressure or under reduced pressure, and different pressures may be applied in each stage of heating.

The thickness of the film, especially when used as a substrate for a flexible display, 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 thin film of a desired thickness.

Still, the method of peeling the film formed in this way from the substrate is not particularly limited, and examples include a method of cooling the film together with the substrate, scoring a slit on the film and peeling it, or giving it through a roller Tension is used as a method of peeling.

[Composition and film for film formation]

As described above, the solution containing polyamic acid or the solution containing polyimide can be suitably used as a film-forming composition for forming a film of polyimide.

That is, by heating the above-mentioned solution containing polyamic acid applied to the substrate, evaporating the solvent while causing the imidization reaction, or by heating the above-mentioned solution containing polyimide applied to the substrate, By evaporating the solvent, a film containing the polyimide of the present invention can be obtained. At this time, the heating temperature is usually about 40 to 500° C., for example, the heating may be performed stepwise in the range of 40 to 150° C., 180 to 350° C., and further in the range of 380 to 450° C.

Still, the adhesion between the polyimide film and the substrate is further improved For the purpose, well-known additives such as coupling agents can also be added to the polyamic acid solution or the polyimide solution.

The film-forming composition described above and the film formed by the composition are also objects of the present invention.

In addition, the well-known additives that can be formulated in the film-forming composition, or the conditions regarding the formation of the polyimide film, etc., can be suitably used in the previously detailed film-forming composition. Additives, or conditions related to the production of thin films formed from the composition.

[Example]

The following examples illustrate the invention in more detail, but the invention is not limited to these. In addition, the abbreviation of the reagent used, the apparatus used, and its conditions are as follows.

<HPLC analysis (1)>

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

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

Dissolving agent:

TB: Acetonitrile/0.5% phosphoric acid aqueous solution=70/30 Sample injection volume: 2μL

TH: Acetonitrile/0.5% phosphoric acid aqueous solution=70/30 Sample injection volume: 1μL

THDNB: Acetonitrile/0.5% phosphoric acid aqueous solution=80/20 Sample injection volume: 10 μL

THDAB: Acetonitrile/water=80/20 Sample injection volume: 5μL

<HPLC analysis (2)>

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

Oven: 40℃, detection wavelength: 200nm, 254nm, flow rate: 1.0mL/min

Dissolving agent:

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

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

< ¹ HNMR analysis>

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

Solvent: DMSO-d6, CDCl ₃

Internal standard substance: Tetramethylsilane (TMS)

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

Installation: Showa Denko Co., Ltd., Showdex GPC-101

Tubing: KD803 and KD805

Column temperature: 50℃

Dissolution solvent: DMF, flow rate: 1.5ml/min

Inspection line: standard polystyrene

[1] Synthesis of compounds

[Synthesis Example 1] Synthesis of 9,10-[1,2]benzoanthracene-13,16(9H,10H)-dione (hereinafter referred to as TB)

Toluene (900 g), anthracene (90 g) and 1,4-benzoquinone (63.32 g) were placed in the flask, the flask was degassed and replaced with nitrogen, and the temperature was raised to dissolve the solid. Then, under reflux conditions (110° C.), the resulting mixture was stirred for 20 hours. In addition, while heating and stirring, the reaction proceeds while confirming the precipitation of the product.

After that, the reaction mixture was cooled to room temperature, and the precipitate was recovered by filtration, and washed with toluene (540 g).

Finally, TB122.73g (yield; 84.9%, HPLC area percentage (holding time; 6.3min); 98.8%) was obtained by drying the washed filtrate (135.64g) under reduced pressure at 60°C.

¹ HNMR (CDCl ₃ , δ ppm): 7.4 (m, 1H), 7.2 (m, 2H), 7.1 (m, 1H), 6.3 (s, 1H), 4.9 (s, 1H), 3.1 (t, 1H ).

[Synthesis Example 2] Synthesis of 9,10-dihydro-9,10-[1,2]benzoanthracene-1,4-diol (hereinafter referred to as TH)

Acetic acid (693.5 g) was placed in the flask, and TB (95 g) obtained in Synthesis Example 1 was placed therein and dissolved. Then, after raising the temperature to 70°C and dropping 47% HBr aqueous solution (7.8 g) over 3 minutes, the resulting mixture was stirred at 70-80°C for 1 hour.

After that, the reaction mixture was cooled to 30° C., and the precipitate was recovered by filtration, and washed with acetic acid (135.76 g) and toluene (221.79 g) in this order.

Finally, TH89.89g (yield; 94.6%, HPLC area percentage (holding time; 4.1min); 99.8%) was obtained by drying the washed filtrate (99.39g) under reduced pressure at 70°C.

¹ HNMR (DMSO-d6, δ ppm): 8.8 (s, 2H), 7.4 (m, 4H), 7.0 (m, 4H), 6.3 (s, 2H), 5.8 (s, 2H).

[Synthesis Example 3] 9,10-dihydro-9,10-[1,2]benzoanthracene-1,4-diyl-bis(4-nitrobenzoate) (hereinafter referred to as THDNB) synthesis

Under nitrogen flow, degassed DMF (2000g) was placed in the flask, and TH (40g) obtained in Synthesis Example 2 was placed and dissolved therein, then triethylamine (42.41g) was added and the temperature was raised to 30 ℃.

Next, about 5-10 g of 4-nitrobenzyl chloride was added to the resulting mixture and stirred for 5 minutes. The addition of 4-nitrobenzyl chloride and the 5-minute stirring were recombined 9 times, and a total of 59.62 g of nitrobenzoyl chloride was added.

After that, the temperature was raised to 50°C and stirred for 2 hours, and 240 g of water was added to the resulting reaction mixture and cooled to 20-30°C, followed by stirring for 16 hours.

After stirring, the precipitate was recovered by filtration, and washed sequentially with water (750 g) and methanol (750 g) to obtain an undried crude product (crude product 1).

The above operation was repeated under the same conditions except that the amount of TH used was 35 g, and an undried crude product (crude product 2) and a total of 211.18 g of undried crude product (crude product) were obtained. 1+2).

The undried crude product (crude product 1+crude product 2) was sufficiently dried at 70° C. under reduced pressure to obtain 157.37 g of dried THDNB crude product.

By mixing 60 g of dried THDNB crude product with DMF (3 L), the resulting suspension was stirred at 120°C for 1 hour and 30 minutes, and cooled to 20°C after stirring. Then, the precipitate was recovered by filtration and washed with methanol (400 g), then dried under reduced pressure at 70°C and washed The net filtrate yielded THDNB52.09g (yield; 86.8%, HPLC area percentage (holding time; 10.0min); 99.2%).

Still, the THDNB of the product obtained above cannot be dissolved in a commonly used deuterated solvent, so it cannot be identified by NMR, but as described later, the fact that THDAB can be obtained by reducing the product can confirm that the product is THDNB .

[Synthesis Example 4] 9,10-dihydro-9,10-[1,2]benzoanthracene-1,4-diyl-bis(4-aminobenzoate) (hereinafter referred to as THDAB) Synthesis (1)

Put the THDNB (10g), 5% Pd-C (STD type, wet product, NE chemcat (share), 1g) and dimethyl obtained in Synthesis Example 3 into the autoclave in which the reaction vessel was replaced with nitrogen After the formamide (70 g) was replaced with hydrogen in the reaction vessel, it was stirred at 30° C. for 21.5 hours under the condition of a hydrogen pressure of 0.8 MPa.

After confirming the completion of the reaction using HPLC, Pd-C was removed from the reaction mixture by filtration, and the Pd-C was washed with dimethylformamide (38g), and the dimethylformamide used was washed. It is recovered together with the filtrate (filtrate 1).

The above operation is performed again, the filtrate (filtrate 2) is recovered, and the filtrate 1 and the filtrate 2 are combined.

Next, after the filtrate (filtrate 1+filtrate 2) was dropped into water (1623 g), the precipitate was recovered by filtration and washed with water (395 g). Then, methanol (300 g) was added to the obtained filtrate, and the slurry was washed at 26°C.

Finally, the mixture was filtered and THDAB (15.46 g) (yield; 86.2%, HPLC area percentage (holding time; 4.7 min); 99.5%) was obtained by drying the filter under reduced pressure at 70°C.

¹ HNMR (DMSO-d6, δ ppm): 8.0 (m, 4H), 7.4 (m, 4H), 7.0 (m, 4H), 6.9 (s, 2H), 6.7 (m, 4H), 6.3 (s, 4H), 5.6 (s, 2H).

[Synthesis Example 5] Synthesis of THDAB (2)

Put the THDNB (10g), 5% Pd-C (STD type, wet product, NE chemcat (share), 1g) and dimethyl obtained in Synthesis Example 3 into the autoclave in which the reaction vessel was replaced with nitrogen After the formamide (70 g) was replaced with hydrogen in the reaction vessel, it was stirred at 30° C. for 92.5 hours under conditions of hydrogen pressure and normal pressure.

After confirming the completion of the reaction using HPLC, Pd-C was removed from the reaction mixture by filtration, and the Pd-C was washed with dimethylformamide (18g), and the dimethylformamide used was washed. Recycle with the filtrate.

Next, after dropping the filtrate into water (679 g), the precipitate was recovered by filtration and washed with water (200 g). Then, methanol (148 g) was added to the obtained filtrate, and the slurry was washed at 23°C.

Finally, the mixture was filtered and THDAB (8.57 g) (yield; 95.5%, HPLC area percentage (holding time; 4.7 min); 99.4%) was obtained by drying the filter under reduced pressure at 70°C.

¹ HNMR (DMSO-d6, δ ppm): 8.0 (m, 4H), 7.4 (m, 4H), 7.0 (m, 4H), 6.9 (s, 2H), 6.7 (m, 4H), 6.3 (s, 4H), 5.6 (s, 2H).

[Synthesis Example 6] (9,10-dihydro-9,10-[1,2]benzoanthracene-1,4-diyl-bis(3-nitrobenzoate) (hereinafter referred to as m- THDNB)

Under a nitrogen stream, TH (20 g) obtained in Synthesis Example 2 was dissolved in DMF (1000 g) at 25° C., and triethylamine (29.8 g) was added.

Next, about 3-5 g of 3-nitrobenzyl chloride was added to the solution at 21°C, and the mixture was stirred at 21°C to 27°C for 5 minutes. This operation was repeated a total of 8 times, and a total of 29.8 g of 3-nitrobenzoyl chloride was added. After stirring at 23°C to 27°C for 18 hours, water (1000 g) was added to the reaction liquid at 25°C, and further stirred at 25°C for 1 hour.

The precipitate was recovered by filtration, and the filtrate was washed with water (200 g) to obtain an undried product of crude m-THDNB. Add all the m-THDNB crude product obtained here to methanol (400g) at 25℃ After stirring for 1 hour, filter and wash the filtrate with methanol (200 g). The obtained filtrate (88.5g) was dried under reduced pressure at 70°C to obtain 43.1g of m-THDNB (yield; 99.3%, HPLC area percentage (holding time; 10.0min); 96.8%).

Still, m-THDNB of the product obtained above cannot be dissolved in a commonly used deuterated solvent, so it cannot be identified by NMR, but as described later, the fact that m-THDAB can be obtained by reducing the product can be confirmed The product is m-THDNB.

[Synthesis Example 7] 9,10-dihydro-9,10-[1,2]benzoanthracene-1,4-diyl-bis(3-aminobenzoate) (hereinafter referred to as m-THDAB ) Synthesis

M-THDNB (40.5g), 5% Pd-C (STD type, wet product, NE chemcat (product), 4.05g) obtained in Synthesis Example 6 was added to N,N-dimethylformamide (284g) ), under normal pressure of hydrogen, stir at 20-30°C for 24 hours. Thereafter, N,N-dimethylformamide (81 g) and 5% Pd-C (4.05 g) were added and stirred for 26 hours.

After confirming the completion of the reaction using HPLC, the filtrate was obtained by removing Pd-C from the reaction mixture by filtration. Also, wash the Pd-C used with N,N-dimethylformamide (81g), and remove the dimethyl used in the washing Formamide is recovered together with the previous filtrate. After water (2300 g) was added dropwise to the recovered filtrate at 25° C., the precipitate was recovered by filtration and the filtrate was washed with water (500 g). Furthermore, by drying the obtained filtrate (66.2 g) at 70° C. under reduced pressure, m-THDAB crude product (35.2 g) was obtained.

This crude m-THDAB product (35.2 g) was dissolved in degassed tetrahydrofuran (106 g), 79% hydrazine monohydrate (30 mg) was added, and cooled to 5°C. To this solution, degassed 2-propanol (317 g) was added dropwise and stirred for 1 hour. The precipitate was filtered, the filtrate was washed twice with degassed 2-propanol (70g), and all the obtained filtrate was dried under reduced pressure at 70°C to obtain a recrystallized m-THDAB. (30.8g).

This m-THDAB recrystallized product (30.8 g) was dissolved in degassed tetrahydrofuran (308 g), and after adding 79 mg of hydrazine monohydrate 30 mg, special egret activated carbon (3.08 g) was added and stirred for 1 hour, followed by filtration. . By drying the obtained filtrate at 70° C. under reduced pressure, m-THDAB activated carbon treated product (28.6 g) was obtained.

Furthermore, this m-THDAB activated carbon treated product was added to degassed hexane (858 g), and stirred under reflux conditions for 1 hour. After cooling to room temperature, the filtrate obtained after filtration was washed three times with degassed hexane (143 g). By drying the obtained filtrate (27.5 g) at 70° C. under reduced pressure, 26.4 g of crystals of m-THDAB (yield; 70.6%, HPLC area percentage (holding time; 6.7 min); 99.7%) .

The results of ¹ HNMR analysis confirmed that the crystal was m-THDAB.

¹ HNMR (DMSO-d6, δ ppm): 7.5 (dd, 2H), 7.4 (m, 6H), 7.3 (dd, 2H), 7.0 (m, 4H), 7.0 (s, 2H), 7.0 (ddd, 2H), 5.6 (s, 2H), 5.6 (br, 4H).

[2] Synthesis of Polyimide (1)

[Example 1]

In a flask replaced with nitrogen, 1.46 g of 2,2'-bis(trifluoromethyl)benzidine (TFMB) and 0.898 g of THDAB were placed. After adding 14.9 g of γ-butyrolactone and stirring, it was confirmed that TFMB and THDAB were dissolved, and then 2,3,5-tricarboxycyclopentylacetic acid-1,4:2,3-dianhydride (TCA) was added 0.728g. Then, the obtained mixture was stirred at 90° C. for 4 hours under a nitrogen atmosphere, and after cooling the reaction mixture to 50° C., further added 0.637 g of 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA) Stir overnight in this state.

After that, the reaction mixture was diluted with γ-butyrolactone so that the solid concentration became 8% by mass. After adding 2.65 g of acetic anhydride and 1.542 g of pyridine to the diluted reaction mixture, the mixture was stirred at 100° C. under a nitrogen atmosphere. 4 hour.

Next, the obtained reaction mixture was dropped into 100 g of methanol and stirred for 30 minutes, and the precipitate was recovered by filtration. Repeat this operation 3 times.

Finally, the obtained filtrate was dried at 150° C. for 8 hours under reduced pressure to obtain polyimide (3.248 g yield: 87.2%).

[Comparative Example 1]

Polyimide (3.22g 86.2%) was obtained in the same manner as in Example 1, except that 0.913g of the following known diamine (hereinafter THDA) was used in place of THDAB, wherein the THDA is the same as that of the present invention. The amine has the same skeleton having 9,10-dihydro-9,10-[1,2]benzoanthracene in the molecule.

Still, THDA was synthesized according to the method described in Journal of Polymer Science Part A: Polymer Chemistry, Vol. 49, 3109-3120 (2011).

[3] Preparation of polyimide solution (varnish)

[Example 2]

The polyimide obtained in Example 1 was dissolved in γ-butyrolactone so that the concentration became 12% by mass to obtain a polyimide solution.

[Comparative Example 2]

A polyimide solution was obtained in the same manner as in Example 2 except that the polyimide obtained in Comparative Example 1 was used instead of the polyimide obtained in Example 1.

[4] Production of polyimide film

[Example 3]

First, the polyimide solution obtained in Example 2 was pressure-filtered using a 5 μm filter.

After that, the filtered polyimide solution was applied on the glass substrate in the atmosphere, and heated at 50° C. for 30 minutes, 140° C. for 30 minutes, and 200° C. for 60 minutes, to obtain a polyimide film. . Then, the obtained polyimide film was engraved with square notches, and the film was peeled off to prepare an evaluation sample.

[Comparative Example 3]

Except that the polyimide solution obtained in Comparative Example 2 was used instead of the polyimide solution obtained in Example 2, the same procedure and method as in Example 3 were used to obtain a polyimide film. Then, the obtained polyimide film was engraved with square notches, and the film was peeled off to prepare an evaluation sample.

[5] Synthesis of Polyimide (2)

[Example 4]

In a 100 mL three-necked flask equipped with a nitrogen injection/discharge port and equipped with a mechanical stirrer and cooler, 10.087 g (31.5 mmol) of TFMB and 1.611 g (3.5 mmol) of THDAB were charged. Next, 45.9 g of γ-butyrolactone was added and stirring was started. Immediately afterwards, 6.76g of norbornane-2-spiro-α-cyclopentanone-α'-spiro-2”-norbornane-5,5”,6,6”-tetracarboxylic dianhydride (CpODA) was added (17.5mmol), then add γ-butyrolactone 9.836g, by heating to 90°C under a nitrogen atmosphere and stirring for 20 minutes. Thereafter, 3.431 g (17.5 mmol) of CBDA and 0.655 g of 1-ethylpiperidine were added, and 9.836 g of γ-butyrolactone was further added, and the mixture was stirred at 180° C. for 6 hours under a nitrogen atmosphere. Next, the obtained reaction mixture was subjected to recovery and purification of precipitates using methanol, and the obtained filtrate was dried to obtain polyimide (Mn: 49,646, Mw: 119,613) at a yield of 86.2%.

[6] Preparation of thin film forming composition

[Example 5]

At room temperature, 3 g of the polyimide obtained in Example 4 was added to the GBL-M prepared by the following [Reference Example]: γ-butyrolactone dispersed silica sol (silica solid content concentration: 25.25 After mixing for 30 minutes in mass%), the composition for film formation (solid content concentration: 18.97 mass%, polyimide: silicon dioxide) can be obtained by placing the stirred mixture in a state of standing overnight. Particles = 3: 7 (mass ratio)).

[Reference example] Preparation example of silica sol

In a 1000 mL round-bottom flask, methanol-dispersed silica sol made by Nissan Chemical Industry Co., Ltd.: MA-ST-M 350g (silica solid content concentration: 40.4% by mass) and 419-gamma-butyrolactone were placed. Then, by connecting the flask to a vacuum evaporator and depressurizing the flask, and immersing it in a warm water bath at about 35°C for 20 to 50 minutes, a silicon in which the solvent is substituted from methanol to γ-butyrolactone can be obtained Stone sol (GBL-M) about 560.3g (silica solid Content concentration: 25.25% by mass).

In addition, in the said silica sol, the average particle diameter calculated from the specific surface area value measured by the nitrogen adsorption method is 22 nm. The specific surface area of the dried powder of silica sol was measured using Monosorb MS-16, a specific surface area measuring device made by Yuasa Ionics, specifically, the measured specific surface area S (m ² /g) and D (nm) =2720/S formula to calculate the average primary particle size.

[7] Film production

[Example 6]

The composition for film formation obtained in Example 5 was applied on a glass substrate, and the coating film was sequentially heated under vacuum of -97 kPa at 50°C for 30 minutes, 140°C for 30 minutes, and 200°C for 60 minutes. Films are available. Still, for heating, three types of ovens set to a desired temperature in advance are used.

The obtained film was peeled off by mechanical cutting and provided for the subsequent evaluation.

[8] Evaluation of polyimide films and films

The heat resistance and optical properties of each film (evaluation sample) produced by the above procedure, that is, the linear expansion coefficient (CTE) of 50°C to 200°C, 5% weight reduction temperature (Td _5% ), light transmission Rate (T _400nm , T _550nm ), CIE b ^* value (yellow evaluation), retardation (R _th , R ₀ ), and birefringence (Δn) were evaluated separately according to the following procedures. The results are shown in Table 1.

1) Coefficient of linear expansion (CTE)

Using TMA Q400 manufactured by TA INSTRUMENTS, the film was cut into a width of 5 mm and a length of 16 mm, and the temperature was first increased at 10° C./min, heated from 50° C. to 300° C. (first heating), and then cooled at 10° C./min. After cooling to 50°C, the temperature is increased at 10°C/min, and the temperature is increased from 50°C to 420°C (second heating). At this time, the linear expansion coefficient (CTE [ppm/ ℃]) to obtain the coefficient of linear expansion. Still, the load of 0.05N is added during the first heating, cooling and second heating.

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

The 5% weight loss temperature (Td _5% [℃]) is a TGA Q500 manufactured by TA INSTRUMENTS. In nitrogen, a film of about 5 to 10 mg is heated from 50℃ to 800℃ at 10℃/min at 10℃/min. The 5% weight reduction temperature can be obtained.

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

The light transmittance (T _400nm , T _550nm [%]) and CIE b value (CIE b ^* ) of wavelengths 400nm and 550nm are based on SA4000 spectrometer manufactured by Nippon Denshoku Industries Co., Ltd., using air as the reference at room temperature Perform the measurement.

4) Delay (R _th , R ₀ )

The Kojira 2100ADH manufactured by Oji Measuring Instruments Co., Ltd. was used to measure the thickness direction retardation (R _th ) and the in-plane retardation (R ₀ ) at room temperature.

Still, the retardation in the thickness direction (R _th ) and in-plane retardation (R ₀ ) can be calculated by the following formula.

R ₀ = (Nx-Ny)×d=△Nxy×d

R _th =[(Nx+Ny)/2-Nz]×d=[(△Nxz×d)+(△Nyz×d)]/2

Nx, Ny: In-plane orthogonal two refractive indexes (Nx>Ny, Nx is also called slow axis, Ny is called fast axis)

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

d: film thickness

△Nxy: the difference between the two refractive indexes in the plane (Nx-Ny) (birefringence)

△Nxz: the difference between the in-plane refractive index Nx and the thickness direction refractive index Nz (birefringence)

△Nyz: the difference between the refractive index Ny in the plane and the refractive index Nz in the thickness direction (birefringence)

5) Film thickness (d)

The film thickness of the obtained thin film was measured with a thickness meter made by TECLOCK (Co., Ltd.).

6) Birefringence (△n)

Using the value of the thickness direction retardation (R _th ) obtained by the aforementioned <4) retardation>, it is calculated according to the following formula.

△N=[R _th /d(thin film thickness)]/1000

As shown in Table 1, the film produced using the diamine of the present invention (Example 3) was compared with the film produced using the known diamine having a similar structure to the diamine of the present invention (Comparative Example 3). ) Has a low coefficient of linear expansion, and has a so-called low value of about 30 ppm/°C. In addition, compared with the comparative example, the transmittance is higher, and the heat resistance is improved, and the yellowness (CIE b ^* ) is also low. In addition, the retardation R _{th in the} thickness direction is also a value less than 700 nm, which is as low as the comparative example.

Furthermore, a thin film (Example 6) produced using the thin film forming composition of the present invention (which includes the polyimide produced using the diamine of the present invention and silicon dioxide particles) (Example 6) Silicon particles, but the light transmittance is high, and the linear expansion coefficient at 50°C to 200°C is about 15 ppm/°C, so it can show a lower linear expansion coefficient than the film of Example 3, that is, it will become The dimensional stability is excellent, and the heat resistance evaluated at a 5% weight reduction temperature is also a result of improvement. In particular, the thickness direction retardation R _th of the film is an extremely low value less than 150 nm, and the birefringence Δn is also a so-called extremely low value of 0.004, where the thickness direction retardation R _th is observed from the thickness direction cross section The two birefringences at the time (the difference between the two refractive indexes in the plane and the refractive index in the thickness direction) are multiplied by the film thickness, respectively, and the obtained two phase differences are expressed as the average value as "the thickness direction retardation R _th ".

The film and the like produced by using the diamine of the present invention have characteristics of low linear expansion coefficient, high transparency (high light transmittance, low yellowness), low retardation, etc., that is, they are suitable for flexible display substrates The requirements for the base film are particularly expected to be suitable for use as a base film for flexible display substrates.

[9] Synthesis of Polyimide (3)

[Example 7]

A 100 mL reaction three-necked flask equipped with a nitrogen injection/discharge port and equipped with a mechanical stirrer was charged with 1.457 g (4.45 mmol) of TFMB and 0.898 g (1.95 mmol) of THDAB. Immediately thereafter, 14.884 g of γ-butyrolactone (GBL) was added and stirring was started. After the diamine was completely dissolved in the solvent, 0.728 g (3.25 mmol) of TCA was added, and the reaction mixture was obtained by stirring at 90°C for 4 hours under a nitrogen atmosphere. Next, the reaction mixture was cooled to 50°C, CBDA 0.637 g (3.25 mmol) was added, and the reaction was allowed to proceed overnight under a nitrogen atmosphere. The next day, the reaction mixture was diluted with GBL so that the solid concentration became 8% by mass, 2.654 g (0.026 mol) of acetic acid and 1.542 g (19.5 mmol) of pyridine were added, and stirred at 100° C. for 4 hours. Next, the resulting reaction mixture was dropped into 100 g of methanol and stirred for 30 minutes, and the solid polyimide was filtered. Repeat this operation 3 times. The methanol in the polyimide was removed by drying in a vacuum oven at 150° C. for 8 hours, and finally, 3.2438 g of dried polyimide I was obtained (yield 81.17%). Then, with a concentration of 12% In the formula, the powdered polyimide I is dissolved in GBL to obtain a polyimide I solution.

[10] Synthesis of Polyimide (4)

[Example 8]

In a 100 mL reaction three-necked flask equipped with a nitrogen injection/discharge port and equipped with a mechanical stirrer, TFMB 1.457 g (4.45 mmol) and THDA 0.913 g (1.95 mmol) were charged. Immediately thereafter, 14.947 g of γ-butyrolactone (GBL) was added and stirring was started. After the diamine was completely dissolved in the solvent, 0.728 g (3.25 mmol) of TCA was added, and the mixture was stirred at 90° C. for 4 hours under a nitrogen atmosphere. Next, it cooled to 50 degreeC, and CBDA 0.637g (3.25mmol) was added, and it was made to react overnight under nitrogen atmosphere. The next day, the reaction mixture was diluted to 8% with GBL, 2.654 g (0.026 mol) of acetic acid and 1.542 g (19.5 mmol) of pyridine were added, and the temperature was raised to a temperature of 100° C. for 4 hours. After that, it was purified in the same manner as in Example 1. Polyimide was obtained to obtain 3.22 g of dried polyimide II (yield 86.23%). Next, the powder polyimide II was dissolved in GBL so that the concentration became 12% by mass to obtain a polyimide II solution.

[11] Synthesis of Polyimide (5)

[Example 9]

TFMB 10.087g (31.5mmol) and THDAB 1.611g (3.5mmol) were charged in a 100mL reaction three-necked flask with a nitrogen injection/discharge port equipped with a mechanical stirrer and a cooler, and then γ-butyrolactone was added (GBL) 45.9g and start stirring. Immediately thereafter, 6.726 g (17.5 mmol) of CpODA was added, followed by 9.836 g of GBL, and stirred for 20 minutes under a nitrogen atmosphere. Next, add CBDA 3.431g (17.5mmol) and 1-ethylpiperidine 0.655g, then add GBL 9.836g, and The solution was stirred at 210°C for 6 hours under a nitrogen atmosphere. Next, the obtained reaction mixture was subjected to recovery and purification of the precipitate using methanol, and the obtained filtrate was dried to obtain polyimide III at a yield of 86.2%.

[12] Synthesis of Polyimide (6)

[Example 10]

A 100 mL reaction three-necked flask equipped with a mechanical agitator and a cooler equipped with a nitrogen injection/discharge port was charged with 1.457 g (4.55 mmol) of TFMB and 1.023 g (1.95 mmol) of m-THDAB, and then γ-butane was added Lactone (GBL) 13.143g and started stirring. Immediately thereafter, 0.728 g (3.25 mmol) of TCA was added, followed by 2.817 g of GBL, and the mixture was stirred at 90° C. for 5 hours under a nitrogen atmosphere. Then, add CBDA 0.637g (3.25mmol), then add GBL 2.817g, and then add nitrogen The solution was stirred at 50°C overnight. The next day, dilute the varnish with GBL 17.92g to 10%, add 2.654g (26mmol) of acetic anhydride and 1.542g (19.5mmol) of pyridine, and react at 100°C for 4 hours. Next, for the obtained reaction mixture, the precipitation of methanol was recovered and purified, and the obtained filtrate was dried to obtain polyimide IV in a yield of 93.3%.

[13] Synthesis of Polyimide (7)

[Example 11]

In a 250 mL reaction three-necked flask equipped with a mechanical agitator, a cooler, and a Dean-Stark distiller device equipped with a nitrogen injection/exhaust port, TFMB 5.764 g (18 mmol) and m-THDAB 1.049 g (2 mmol) were charged, followed by , Add 31.569g of γ-butyrolactone (GBL) and start stirring. Immediately thereafter, 2.5 g (10 mmol) of BODAxx was added, and then 6.765 g of GBL and 0.22 g of 1-ethylpiperidine were added, and the mixture was stirred at 140° C. for 5 hours under a nitrogen atmosphere. Next, add CBDA 1.961g(10 mmol) and 0.22 g of 1-ethylpiperidine, followed by the addition of 6.765 g of GBL, and the solution was stirred at 180° C. for 7 hours under a nitrogen atmosphere. Next, for the obtained reaction mixture, the precipitation of methanol was recovered and purified, and the obtained filtrate was dried to obtain polyimide V in a yield of 85.5%.

[14] Synthesis of Polyimide (8)

[Example 12]

A 250 mL reaction three-necked flask equipped with a mechanical agitator, a cooler, and a Dean-Stark distiller device with a nitrogen injection/discharge port was charged with 4.483 g (14 mmol) of TFMB and 3.147 g (6 mmol) of m-THDAB, and then, Add 33.858 g of γ-butyrolactone (GBL) and start stirring. Immediately thereafter, 2.5 g (10 mmol) of BODAxx was added, followed by 7.255 g of GBL and 0.22 g of 1-ethylpiperidine, and the mixture was stirred at 140° C. for 5 hours under a nitrogen atmosphere. Next, CBDA 1.961g (10mmol) and 1-ethylpiperidine 0.24g were added, followed by GBL 7.255g, The solution was stirred at 180°C for 7 hours under a nitrogen atmosphere. Next, the obtained reaction mixture was subjected to recovery and purification of the precipitates using methanol, and the obtained filtrate was dried to obtain polyimide V in a yield of 84.7%.

[15] Preparation of polyimide film-forming composition and production of polyimide film

[Example 13]

At room temperature, 1 g of the polyimide I obtained in Example 7 was dissolved in GBL solvent so that the polyimide concentration became 12% by mass, and this solution was passed through a 5 μm filter and slowly filtered under pressure A composition for film formation can be obtained. Next, the obtained composition for forming a thin film was coated on a glass substrate, and heated at 50° C. for 30 minutes, 140° C. for 30 minutes, and 200° C. for 60 minutes in the atmosphere to obtain a transparent film PI-I. The obtained film was mechanically cut and peeled off from the glass substrate. Table 2 shows the optical and thermal properties.

[16] Preparation of polyimide film-forming composition and production of polyimide film

[Example 14]

At room temperature, 1 g of the polyimide II obtained in Example 8 was dissolved in GBL solvent so that the polyimide concentration became 12% by mass, and this solution was passed through a 5 μm filter and slowly filtered under pressure A composition for film formation can be obtained. Next, the obtained composition for forming a thin film is applied The transparent film PI-II can be obtained by heating on a glass substrate at 50°C for 30 minutes, 140°C for 30 minutes and 200°C for 60 minutes under the atmosphere. The obtained film was mechanically cut and peeled off from the glass substrate. Table 2 shows the optical and thermal properties.

[17] Preparation of polyimide film-forming composition and production of polyimide film

[Example 15]

At room temperature, 1 g of the polyimide III obtained in Example 9 was dissolved in GBL solvent so that the polyimide concentration became 12% by mass, and the solution was passed through a 5 μm filter and slowly filtered under pressure A composition for film formation can be obtained. Next, the obtained composition for forming a thin film was coated on a glass substrate, and heated at 50° C. for 30 minutes, 140° C. for 30 minutes, and 200° C. for 60 minutes in the atmosphere to obtain a transparent film PI-III. The obtained film was mechanically cut and peeled off from the glass substrate. Table 2 shows the optical and thermal properties.

[18] Preparation of polyimide film-forming composition and production of polyimide film

[Example 16]

At room temperature, 3 g of the polyimide III obtained in Example 9 was dissolved in GBL solvent so that the polyimide concentration became 12% by mass, and the solution was passed through a 5 μm filter and slowly filtered under pressure , The obtained solution was added to GBL-M described in Example 5: γ-butyrolactone-dispersed silica sol (SiO ₂ 25.25% with a size of 18 to 23 nm dispersed in γ-butyrolactone) 3.326 After mixing in g for 30 minutes, the composition for film formation can be obtained by leaving it to stand. The thin film forming composition was coated on a glass substrate and heated under reduced pressure of -97 kPa at 50°C for 30 minutes, at 140°C for 30 minutes and at 200°C for 60 minutes to obtain a transparent film PI-III-A . The obtained film was mechanically cut and peeled off from the glass substrate. Table 2 shows the optical and thermal properties.

[19] Preparation of polyimide film-forming composition and production of polyimide film

[Example 17]

At room temperature, 1 g of the polyimide IV obtained in Example 4 was dissolved in GBL solvent so that the polyimide concentration became 12% by mass, and the solution was passed through a 5 μm filter and slowly filtered under pressure A composition for film formation can be obtained. Next, the obtained film-forming composition was coated on a glass substrate, heated at 50°C for 30 minutes, 140°C for 30 minutes, and 200°C for 60 minutes in the atmosphere, and then reduced to -280 kPa at 280 Heating at ℃ for 60 minutes can obtain the transparent film PI-IV. The obtained film was mechanically cut and peeled off from the glass substrate. Table 3 shows the optical and thermal properties.

[20] Preparation of polyimide film forming composition and preparation of polyimide film

[Example 18]

At room temperature, 1 g of polyimide V obtained in Example 11 was dissolved in GBL solvent so that the concentration of polyimide was 12% by mass, and the solution was passed through a 5 μm filter and slowly filtered under pressure A composition for film formation can be obtained. Next, the obtained film-forming composition was applied on a glass substrate, heated at 50°C for 30 minutes, 140°C for 30 minutes, and 200°C for 60 minutes in the atmosphere, and then reduced to -280 kPa at 280 The transparent film PI-V can be obtained by heating at ℃ for 60 minutes. The obtained film was mechanically cut and peeled off from the glass substrate. Table 3 shows the optical and thermal properties.

[21] Preparation of polyimide film-forming composition and production of polyimide film

[Example 19]

At room temperature, 1 g of the polyimide V obtained in Example 6 was dissolved in GBL solvent so that the polyimide concentration became 12% by mass, and the solution was passed through a 5 μm filter and slowly filtered under pressure A composition for film formation can be obtained. Next, the obtained film-forming composition was applied on a glass substrate, heated at 50°C for 30 minutes, 140°C for 30 minutes, and 200°C for 60 minutes in the atmosphere, and then reduced to -280 kPa at 280 After heating at ℃ for 60 minutes, a transparent film PI-VI can be obtained. The obtained film was mechanically cut and peeled off from the glass substrate. Table 2 shows the optical and thermal properties.

[22] Evaluation of polyimide membrane

The optical and thermal properties of each polyimide film produced in Examples 13 to 19 were measured using the following equipment.

The light transmittance (T _{400 nm} and T _{550 nm} ) and yellowness (CIE b ^* ) of the polyimide film were measured at room temperature using Nippon Denshoku SA4000 spectrometer.

Using KOBURA 2100 ADH manufactured by Oji Measuring Equipment Co., Ltd., the thickness aromatic retardation (R _th ) and the internal retardation (R _o ) were measured at room temperature.

The linear expansion coefficient (CTE) was measured using a TMA Q400 from TA INSTRUMENTS at a heating rate of 10°C/min under a nitrogen flow, and measured at a temperature range of 50°C to 200°C.

The thermal decomposition temperature (Td point) was implemented under a nitrogen flow at a heating rate of 10°C/min using TGA Q500 of TA INSTRUMENTS. A weight loss of 0% is specified at 150°C.

The number average molecular weight (Mn) and the weight average molecular weight (Mw) were determined using Showdex GPC-101 manufactured by Showa Denko Co., Ltd. A PTFE 0.45 μm filter used for polymer filtration is used, and standard polystyrene is used for the calibration line.

The film forming system was implemented using COTEST INSTRUMENTS OF AUTOMATIC FILM APPLICATOR PFA-2010-1, and the film baking system was implemented using Deng YNG's round oven DO45.

The film thickness is measured by a thickness meter manufactured by TECLOCK Corporation.

As shown in Tables 2 and 3, the membranes manufactured using the diamine of the present invention (Example 13 to Example 15, Example 17 to Example 19) have a low linear expansion coefficient and high transmittance In addition, the heat resistance is also good, and the yellowness (CIE b ^* ) is also low. Moreover, even the retardation R _{th in the} thickness direction is a good result.

Furthermore, a thin film (Example 16) manufactured using the thin film forming composition of the present invention (which includes the polyimide manufactured using the diamine of the present invention and silicon dioxide particles) (Example 16) Silicon particles, but with high light transmittance, the coefficient of linear expansion at 50°C to 200°C shows a so-called very low value of about 16 ppm/°C. That is, the heat resistance evaluated as a dimensional stability during heating is excellent, and the 5% weight reduction temperature is also a result of improvement. In particular, the thickness direction retardation R _th of the film is an extremely low value less than 150 nm, and the birefringence Δn is also a so-called extremely low value of 0.004, where the thickness direction retardation R _th is observed from the thickness direction cross section The two birefringences at the time (the difference between the two refractive indexes in the plane and the refractive index in the thickness direction) are multiplied by the film thickness, respectively, and the obtained two phase differences are expressed as the average value as "the thickness direction retardation R _th ".

The film and the like produced by using the diamine of the present invention have characteristics of low linear expansion coefficient, high transparency (high light transmittance, low yellowness), low retardation, etc., that is, they are suitable for flexible display substrates The requirements for the base film are particularly expected to be suitable for use as a base film for flexible display substrates.

Claims (18)

A diamine whose characteristics are represented by formula (1-1),

(In the formula, R ₁ , R ₂ , R ₃ , R ₄ and R ₅ each independently represent a halogen atom, an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms, R ₆ and R ₇ represents independently hydrogen atom, halogen atom, alkyl group having 1 to 5 carbon atoms or alkoxy group having 1 to 5 carbon atoms, a, b, d and e independently represent integers of 0 to 4, and c is an integer from 0 to 2). If the diamine of claim 1, it is the diamine represented by formula (1-2),

If the diamine of claim 2 is a diamine represented by formula (1-3) or formula (1-4),

Polyamide acid, which is a reactant of a diamine component and an acid dianhydride component, the diamine component contains any one of any one of claim 1 to claim 3 amine. The polyamic acid according to claim 4, wherein the diamine component further includes the diamine represented by formula (A1), [Chem 4] H ₂ NB ² -NH ₂ (A1) (where B ² represents (A bivalent group selected by the group formed by formulas (Y-1)~(Y-34)),

(In the formula, * means a bond). The polyamic acid according to claim 4 or claim 5, wherein the acid dianhydride component includes the acid dianhydride represented by formula (C1),

[In the formula, B ¹ represents a 4-valent group selected from the group consisting of formulas (X-1) to (X-12),

(In the formula, plural R systems independently represent a hydrogen atom or a methyl group, and * systems represent a bonding bond)]. A polyimide obtained by polyimidization of the polyamic acid of any one of claim 4 to claim 6. A thin film forming composition comprising the polyimide of claim 7, an organic solvent, and silica particles, the silica particles having an average particle diameter calculated by a specific surface area value measured by a nitrogen adsorption method is Below 100nm. The thin film forming composition according to claim 8, wherein the mass ratio of the polyimide to the silicon dioxide particles is 1:10 to 10:1. The thin film forming composition according to claim 8 or claim 9, wherein the average particle diameter is 60 nm or less. A thin film formed by the thin film forming composition of any one of claim 8 to claim 10. A substrate for a flexible device, which is made of the film of claim 11. A film-forming composition comprising the polyimide of claim 7 and an organic solvent. A substrate for a flexible device, which is formed of the film formed by the film-forming composition of claim 13. A dinitro compound, whose characteristic is represented by formula (2-1),

(In the formula, R ₁ , R ₂ , R ₃ , R ₄ and R ₅ each independently represent a halogen atom, an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms, R ₆ and R ₇ represents independently hydrogen atom, halogen atom, alkyl group having 1 to 5 carbon atoms or alkoxy group having 1 to 5 carbon atoms, a, b, d and e independently represent integers of 0 to 4, and c is an integer from 0 to 2). If the dinitro compound of claim 15 is a dinitro compound represented by formula (2-2),

If the dinitro compound of claim 16, it is a dinitro compound represented by formula (2-3) or formula (2-4),

A manufacturing method which is a method for manufacturing the diamine represented by formula (1-1), which includes reducing the nitro group of the dinitro compound represented by formula (2-1) to obtain the formula (1-1) The stage of diamine,

(In the formula, R ₁ , R ₂ , R ₃ , R ₄ and R ₅ each independently represent a halogen atom, an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms, R ₆ and R ₇ represents independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms, and a, b, d, and e independently represent integers of 0 to 4, and c is an integer from 0 to 2),

(In the formula, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , a, b, c, d, and e represent the same meaning as described above).