WO2012090827A1 - Polyimide complex, polyamic acid solution, method for manufacturing polyimide complex, and film produced from polyimide complex - Google Patents

Abstract

The objective of the present invention is to provide a polyimide complex that emits fluorescence having a specific wavelength and achieves high fluorescence intensity as a result of being irradiated with ultraviolet rays without compromising the colorless transparency, mechanical properties, and heat resistance of a polyimide having a specific structure, and to provide a method for manufacturing the complex. This polyimide complex is obtained by adding 0.001-4 parts by weight of a europium (Eu) compound per 100 parts by weight of a polyamic acid solution (S1) obtained from a specific polyamic acid obtained from an alicyclic diamine compound (A) and an aromatic tetracarboxylic dianhydride (B) as well as a solvent (C) in which the polyamic acid dissolves, obtaining a polyamic acid solution (S2), and imidating the polyamic acid contained in the polyamic acid solution (S2) and removing the solvent (C).

Description

Polyimide composite, polyamic acid solution, method for producing polyimide composite, and film comprising polyimide composite

The present invention relates to a polyimide composite and a method for producing a polyimide composite.
Specifically, the present invention relates to a polyimide composite containing a europium (Eu) compound, which is colorless and transparent, emits fluorescence of a specific wavelength instantaneously by irradiation with ultraviolet rays, and has high fluorescence intensity, and a method for producing the same.

Polyimides have been widely used in various fields as molding materials, composite materials, electrical and electronic materials because of their excellent heat resistance, mechanical properties, and electrical properties.

Conventionally, a polyimide is generally obtained by a method in which a diamine and tetracarboxylic dianhydride are reacted in a solvent to form a polyamic acid, which is dehydrated and cyclized.
Among these, many of the polyimides obtained from aromatic tetracarboxylic dianhydride and aromatic diamine are excellent in heat resistance and mechanical properties. However, these polyimides have a reddish brown to yellow resin and have a problem in optical properties. In addition, both diamine and tetracarboxylic dianhydride, or one of them, has an alicyclic structure, or introduces a relatively bulky and low polarizability fluorine group or trifluoromethyl group. As a result, a polyimide having colorless transparency can be obtained, but there are examples in which the heat resistance and mechanical properties of the polyimide cannot be imparted.

On the other hand, fluorescent materials can generally be classified into three categories: quantum dots, organic dyes, and rare earth complexes. Quantum dots have a wide absorption band, excellent light emission characteristics, and long-term stability, but have the drawback of a small Stokes shift. Here, the fluorescent material generally has a difference between the excitation wavelength and the fluorescence wavelength, and the wavelength difference is called a Stokes shift. In addition, organic dyes have characteristics such as a high extinction coefficient, quantum yield, and good processability, but they have difficulty in photostability. On the other hand, rare earth complexes have a high quantum yield but a low extinction coefficient.
Further, when these fluorescent materials are low molecular weight compounds, problems such as aggregation of the low molecular fluorescent material and quenching, and bleeding out from the resin remain when mixed with the resin as the base material.
Some rare earth cations emit fluorescence in a wide wavelength range from ultraviolet to infrared. Since these are based on f-orbital electron transitions (ff transitions) that are not easily affected by external fields such as ligand fields, the wavelength band of the emission band is very narrow compared to organic phosphors, etc., and in principle the color purity is high. It is a useful fluorescent species. Further, since it is excellent in stability against heat and light, it has been applied to a display of a television receiver.

For example, a complex such as a metal complex containing europium (Eu) generates red fluorescence by excitation with ultraviolet light.
Patent Document 1 discloses a fluorescent material made of a transparent polyimide using tetracarboxylic dianhydride containing diphenyl ether and the like, and diamine containing an alicyclic structure in the main chain as raw materials. The polyimide emits fluorescence in the blue to violet region by shortening the emission wavelength, and the polyimide itself emits light when irradiated with ultraviolet rays.

Patent Document 2 discloses an optical memory material in which a rare earth element ion is contained in a polymer having a carbonyl group in the main chain or side chain of the polymer. Since the invention focuses on the optical memory effect, a large amount of rare earth element ions are added to provide optical memory properties. Therefore, it is not possible to obtain excellent mechanical properties and electrical properties possessed by polyimide. Moreover, in order to improve the light emission luminance, it is necessary to irradiate with ultraviolet rays for a long time, and high-speed response cannot be obtained.

JP 2005-320393 A JP 2005-70579 A

The present invention is a polyimide composite that emits fluorescence of a specific wavelength by irradiation with ultraviolet rays and has high fluorescence intensity without impairing the colorless transparency, mechanical properties and heat resistance of the polyimide having a specific structure. And providing a manufacturing method thereof.

As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved by combining a polyimide having a specific structure and a europium (Eu) compound, thereby completing the present invention. I arrived. That is,
The polyimide composite of the present invention is obtained by dissolving the polyamic acid represented by the general formula (1) obtained from the alicyclic diamine compound (A) and the aromatic tetracarboxylic dianhydride (B) and the polyamic acid. 0.001 to 4 parts by weight of a europium (Eu) compound is added to 100 parts by weight of the polyamic acid solution (S1) obtained from the solvent (C) to obtain a polyamic acid solution (S2). It is obtained by imidation of polyamic acid contained in the acid solution (S2) and removal of the solvent (C).

(In formula (1), X represents a divalent alicyclic group having 4 to 15 carbon atoms, and Y represents a tetravalent aromatic group having 6 to 27 carbon atoms.)
Moreover, it is preferable that the polyimide contained in the said polyimide composite contains the structural unit represented by following General formula (2).

In the formula (2), X is

At least one alicyclic group selected from the group consisting of:
Y is

At least one aromatic group selected from the group consisting of:

It is also preferred that the polyimide contained in the polyimide composite contains a structural unit represented by the following general formula (3).

It is also preferable that the polyimide contained in the polyimide composite includes a structural unit represented by the following general formula (4).

It is also preferable that the polyimide contained in the polyimide composite includes a structural unit represented by the following general formula (5).

It is also preferable that the polyimide contained in the polyimide composite includes a structural unit represented by the following general formula (6).

(In the formula, m and n represent the number of repeating structural units represented in parentheses, and the ratio of the average value of m to the average value of n (m: n) is 1: 9 to 9: 1)
The europium (Eu) compound is preferably at least one selected from europium chloride, europium nitrate and europium acetate.

The polyimide composite of the present invention usually emits fluorescence having a wavelength of 500 to 800 nm by irradiating with an ultraviolet ray having a wavelength of 250 to 400 nm.
The polyimide composite preferably has a total light transmittance of 80% or more.

The film of the present invention comprises the polyimide composite of the present invention.
The method for producing a polyimide composite according to the present invention includes the following steps 1 to 3.

(Step 1) The polyamic acid represented by the general formula (1) obtained from the alicyclic diamine compound (A) and the aromatic tetracarboxylic dianhydride (B), and the solvent (C A step of obtaining a polyamic acid solution (S1) obtained from

(In formula (1), X represents a divalent alicyclic group having 4 to 15 carbon atoms, and Y represents a tetravalent aromatic group having 6 to 27 carbon atoms.)

(Step 2) A step of adding 0.001 to 4 parts by weight of a europium (Eu) compound to 100 parts by weight of the polyamic acid to obtain a polyamic acid solution (S2), and (Step 3) the polyamic acid solution (S2 The process of obtaining a polyimide composite by imidation of the polyamic acid contained in), and solvent (C) removal.

The polyamic acid solution (S2) of the present invention includes a polyamic acid represented by the following general formula (1),

(In formula (1), X represents a divalent alicyclic group having 4 to 15 carbon atoms, and Y represents a tetravalent aromatic group having 6 to 27 carbon atoms.)
It is characterized by being obtained by adding 0.001 to 4 parts by weight of a europium (Eu) compound to 100 parts by weight of the polyamic acid in the solvent (C) in which the polyamic acid is dissolved.

It is preferable that the solvent (C) is an aprotic amide solvent.

The polyimide composite obtained by the present invention instantaneously emits fluorescence of a specific wavelength by irradiating with ultraviolet rays without impairing the optical properties (colorless transparency), mechanical properties and heat resistance inherent to the polyimide alone. To emit. Moreover, since the fluorescence intensity is very high, fluorescence can be emitted efficiently. Therefore, this polyimide composite is used for wavelength conversion materials, display materials such as displays, fluorescent materials such as fluorescent paints, security printing materials such as security inks, lighting materials, photovoltaic power generation materials, and radiation sensors. It is suitable for materials for agricultural use, agricultural films and the like.

FIG. 1 shows fluorescence emission spectra when the films obtained in Synthesis Example 2, Examples 2, 3 and Reference Example 1 were irradiated with ultraviolet rays.

The polyimide composite of this invention and its manufacturing method are demonstrated.
<Polyamic acid solution (S1)>
(Polyamide acid)
In the present invention, when preparing a polyimide composite, it is possible to use a solution (S1) containing a polyamic acid which is a polyimide precursor, that is, a polyamic acid varnish (also referred to as a polyimide precursor varnish). The polyamic acid is obtained from the reaction of the alicyclic diamine compound (A) and the aromatic tetracarboxylic dianhydride (B) in the presence of a solvent in which the polyamic acid is dissolved, and is represented by the following general formula (1). It has a semi-alicyclic repeating structure.

(In formula (1), X represents a divalent alicyclic group having 4 to 15 carbon atoms, and Y represents a tetravalent aromatic group having 6 to 27 carbon atoms.)
The concentration of the polyamic acid in the polyamic acid solution (S1) is not particularly limited as long as a polyimide composite can be produced, but preferably 100 to 10,000 parts by weight of solvent, more preferably 200 to 5000 parts per 100 parts by weight of polyamic acid. Parts by weight.

Since the polyimide according to the present invention is composed of the alicyclic diamine compound (A) and the aromatic tetracarboxylic dianhydride (B), it depends on the carboxyl group that is present in the state of the precursor polyamic acid. A carbochelate anion and a metal cation can form an ionic bond. For this reason, a europium (Eu) compound can be suitably combined, and it is colorless and transparent without impairing mechanical properties and heat resistance. For example, irradiation with 200 to 400 nm ultraviolet light usually gives fluorescence of 500 to 800 nm. It can be emitted instantly. In order to promote fluorescence emission due to the ff transition of europium (Eu), as an organic molecular site capable of coordinating with europium in close proximity so that a π-electron donor can efficiently transfer energy via the optical antenna effect, It is considered that the case of having aromaticity can have very high fluorescence intensity. Therefore, the polyimide composite of the present invention can emit fluorescence efficiently.

(Divalent alicyclic diamine compound (A))
X in the repeating structure of the formula (1) is derived from the divalent alicyclic diamine compound (A). The diamine compound (A) is not particularly limited as long as a polyamic acid and a polyimide can be produced.
Cyclobutanediamines, cyclohexanediamines (including trans-1,4-cyclohexylamine), di (aminomethyl) cyclohexanes (bis (aminomethyl) cyclohexanes such as 1,4-bis (aminomethyl) cyclohexane), diamino Bicycloheptanes, diaminomethylbicycloheptanes (including norbornanediamines such as norbornanediamine), diaminooxybicycloheptanes, diaminomethyloxybicycloheptanes (including oxanorbornanediamines such as oxanorbornanediamine), isophoronediamine, etc. Isophoronediamines, diaminotricyclodecanes, diaminomethyltricyclodecanes, bis (aminocyclohexyl) mess such as bis (4-aminocyclohexyl) methane Emissions include (4,4'-methylenebis (methylenebis cyclohexyl amine) (cyclohexylamine) compound), bis (aminocyclohexyl) isopropylidene and the like can be mentioned.

Preferred alicyclic diamine compounds (A) include cyclohexanediamines containing trans-1,4-cyclohexylamine, 1, for reasons of availability, good optical properties, and thermal and mechanical stability. Di (aminomethyl) cyclohexanes including 4-bis (aminomethyl) cyclohexane, diaminomethylbicycloheptanes (including norbornanediamines such as norbornanediamine), oxanorbornanediamine, isophoronediamine, 4,4'-methylenebis (cyclohexyl) Amine). If the diaminomethylbicycloheptanes (including norbornanediamines) are described in more detail, (2S, 5S) -diaminomethyl-bicyclo [2.2.1] heptane, (2S, 5R) -diaminomethyl -Bicyclo [2.2.1] heptane, (2S, 6R) -diaminomethyl-bicyclo [2.2.1] heptane, and (2S, 6S) -diaminomethyl-bicyclo [2.2.1] heptane Can be mentioned. Although this diaminomethylbicycloheptane has an isomer, it can be used alone or as a mixture of isomers.
Moreover, you may use these diamine compounds (A) individually or in mixture of 2 or more types.

(Tetravalent aromatic tetracarboxylic dianhydride (B))
Y in the repeating structure of the formula (1) is derived from the tetravalent aromatic tetracarboxylic dianhydride (B). The acid dianhydride (B) is not particularly limited as long as a polyamic acid and a polyimide can be produced.
Pyromellitic dianhydrides such as pyromellitic dianhydride, biphenyltetracarboxylic dianhydrides such as 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, benzophenonetetracarboxylic dianhydride Bis (dicarboxyphenyl) ether dianhydrides such as bis (3,4-dicarboxyphenyl) ether dianhydride, bis (carboxyphenyl) ester dianhydrides, 2,2-bis (3 And bis (dicarboxyphenyl) hexafluoropropane dianhydride such as 4-dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane dianhydride.

Among them, a preferable acid dianhydride (B) is a donor having a π electron system with a high extinction coefficient that can efficiently transfer the photoexcitation energy of an organic molecule through the optical antenna effect. Pyromellitic dianhydrides, biphenyltetracarboxylic dianhydrides, bis (dicarboxyphenyl) ether dianhydrides, and the like. More specifically, 1,2,4,5-pyrrole Mellitic acid dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride.
Moreover, you may use these acid dianhydrides (B) individually or in mixture of 2 or more types.

(solvent)
The solvent used in the preparation of the polyamic acid solution (S1) according to the present invention is not particularly limited as long as the formed polyamic acid can be dissolved.
Phenol, o-chlorophenol, m-chlorophenol, p-chlorophenol, o-cresol, m-cresol, p-cresol, 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6 Phenolic solvents such as xylenol, 3,4-xylenol, 3,5-xylenol;
N, N-dimethylformamide, N, N-dimethylacetamide, N, N-diethylacetamide, N-methylacetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, N-methylcaprolactam Aprotic or similar amide solvents such as hexamethylphosphorotriamide;
1,2-dimethoxyethane, bis (2-methoxyethyl) ether, 1,2-bis (2-methoxyethoxy) ethane, tetrahydrofuran, bis [2- (2-methoxyethoxy) ethyl] ether, 1,4-dioxane Ether solvents such as;
Pyridine, quinoline, isoquinoline, α-picoline, β-picoline, γ-picoline, isophorone, piperidine, 2,4-lutidine, 2,6-lutidine, trimethylamine, triethylamine, tripropylamine, tributylamine solvents; and dimethyl sulfoxide Dimethylsulfone, diphenyl ether, sulfolane, diphenylsulfone, tetramethylurea, anisole, water, benzene, toluene, o-xylene, m-xylene, p-xylene, chlorobenzene, o-dichlorobenzene, m-dichlorobenzene, p-dichlorobenzene, bromobenzene, o-dibromobenzene, m-dibromobenzene, p-dibromobenzene, o-chlorotoluene, m-chlorotoluene, p-chlorotoluene, o-bromotoluene, m-bromotolu Ene, p-bromotoluene, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, γ-butyrolactone, methanol, ethanol, propanol, isopropanol, butanol, isobutanol, pentane, hexane, heptane, cyclohexane, dichloromethane, chloroform, Other solvents such as carbon tetrachloride, fluorobenzene, methyl acetate, ethyl acetate, butyl acetate, methyl formate, and ethyl formate are listed.

These solvents may be used alone or in combination of two or more.
Among the above-mentioned solvents, aprotic or equivalent amide solvents are preferred, and N, N-dimethylformamide, N, N-dimethylacetamide, N, N-diethylacetamide, N-methylacetamide, N-methyl-2-pyrrolidone 1,3-dimethyl-2-imidazolidinone, N-methylcaprolactam, and hexamethylphosphorotriamide are more preferable.

(Preparation of polyamic acid solution (S1))
The polyamic acid solution (S1) containing the polyamic acid and the solvent (also referred to as polyamic acid varnish) is not particularly limited as long as the polyamic acid can be produced. Examples thereof include the following production methods.

Generally, it is obtained by polymerizing the diamine compound (A) and the acid dianhydride (B) in the solvent, typically an aprotic amide solvent.
In carrying out the polymerization reaction, the method for adding each raw material to the polymerization reaction system is not particularly limited,
(A) a method of simultaneously adding the diamine compound (A), the acid dianhydride (B) and the solvent,
(B) A method of adding the acid dianhydride (B) after mixing the diamine compound (A) and the solvent,
(C) A method of adding the diamine compound (A) after mixing the acid dianhydride (B) and the solvent,
(D) The method of mixing and adding each after mixing an acid dianhydride (B), a solvent, a diamine compound (A), and a solvent, respectively. Further, in performing the temperature control during the polymerization reaction, a cooling or heating operation may be performed.

In the production of polyamic acid or polyimide, it is usual to adjust the quantitative ratio between the diamine compound (A) and the acid dianhydride (B) in order to adjust the molecular weight of the produced polyamic acid or polyimide.

In the production method of the present invention, when the polyamic acid is produced, the molar ratio of the total diamine compound (A) to the total acid dianhydride (B) (total diamine compound (A) / total acid dianhydride (B )) Is usually in the range of 0.9 to 1.1. When the oligomer component is polymerized, the molar ratio of the diamine compound (A) to the acid dianhydride (B) is arbitrary and may or may not be in the range of 0.9 to 1.1.

For example, when the molar ratio of the total diamine compound (A) to the total acid dianhydride (B) is 0.9 to 1.1, a concentration of 0.5 g / dl in N, N-dimethylacetamide (DMAc) A polyamic acid having a logarithmic viscosity measured at 35 ° C. in the range of usually 0.1 to 3.0 dL / g can be produced.

The molecular terminal of the polyimide contained in the polyimide composite obtained by the present invention and its polyamic acid may be sealed. When the molecular terminal is sealed, as is conventionally known, it is desirable to seal with a group that is not reactive with amines and dicarboxylic anhydrides.

Specifically, it is desirable that molecular ends of polyimide and polyamic acid are sealed with a dicarboxylic acid anhydride or a monoamine compound.
When the molecular ends of polyamic acid or polyimide are sealed, the following two methods are used. That is, when the diamine compound is excessive and the terminal is sealed with a dicarboxylic anhydride, the tetracarboxylic dianhydride (B) is 0.9 mol or more and less than 1.0 mol per mol of the diamine compound. An acid anhydride is 0.001 mol or more and less than 0.3 mol. When the tetracarboxylic dianhydride (B) is excessive and the end is sealed with a monoamine compound, the diamine compound (A) is 0.9 mole or more per mole of the tetracarboxylic dianhydride (B). Less than 0.0 mol, and the monoamine compound is 0.001 mol or more and less than 0.3 mol.

In addition, when polyamic acid or polyimide is a copolymer, the ordering property and regularity of two or more kinds of repeating units constituting the copolymer may or may not be limited. Further, the type of copolymer may be random, alternating, or block. Therefore, when the diamine compound (A) and the acid dianhydride (B) are composed of three or more kinds, the order of addition is arbitrary, and the addition method of these raw materials may be either batch or divided.

<Polyamic acid solution (S2)>
The polyamic acid solution (S2) of the present invention can be obtained by adding a europium (Eu) compound to the polyamic acid solution (S1).

The europium (Eu) compound is not limited as long as the effects of the present invention are exhibited, and examples thereof include europium oxide, europium hydroxide, europium inorganic acid salt, europium organic acid salt, and europium organic complex. Among these, europium chloride, europium nitrate, and europium acetate are preferable. These europium compounds can be used alone or as a mixture of other metal compounds containing two or more europium compounds.

In the present invention, by adding a europium (Eu) compound to the polyamic acid solution (S1) according to the present invention, the resulting polyimide composite can be obtained without impairing optical properties (colorless and transparent), mechanical properties, and heat resistance. On the other hand, irradiation with ultraviolet rays (for example, a wavelength of 250 to 400 nm) usually produces an effect of instantaneously emitting fluorescence having a wavelength of 500 to 800 nm. Moreover, the fluorescence intensity is very high.

It is considered that the excitation energy for promoting light emission by the ff transition of europium (Eu) can be obtained through the optical antenna effect by forming a complex with the organic molecule. Therefore, by using a donor having a π electron system with a high extinction coefficient, for example, an aromatic compound, the efficiency of energy transfer becomes very high. Therefore, it is desirable that the closest ligand capable of imparting excitation energy is an aromatic system, and the europium compound having some strong interaction with the aromatic tetracarboxylic dianhydride (B) is efficient. It is estimated that fluorescence can be emitted. That is, even if a europium compound is simply added to polyimide, the effect of the present invention cannot be expected for polyimide. And it originates from the interaction based on such a specific structure, and it is estimated that the polyimide composite obtained will have the physical property of this invention.

This is because, for example, a polyimide complex obtained from a europium compound, an aromatic tetracarboxylic dianhydride, and an aromatic diamine has a complex called a charge transfer complex (CT complex) in the polyimide molecule. Since it forms, it can also be estimated from the non-radiative transition, and the fluorescence emission becomes extremely low.

(Preparation of polyamic acid solution (S2))
The polyamic acid solution (S2) (also referred to as a composite varnish) is prepared by adding a europium (Eu) compound to a polyamic acid solution (S1) containing a polyamic acid and a solvent and mixing them.

The amount of the europium compound added is not limited as long as the effects of the present invention can be achieved, but preferably 0.001 to 4 parts by weight, more preferably 0.01 to 3.5 parts by weight with respect to 100 parts by weight of the polyamic acid. Parts, more preferably 0.1 to 3 parts by weight. When the addition amount of the europium compound is 0.001 part by weight or more, sufficient fluorescence is obtained even when diluted, and when it is 4 parts by weight or less, the mechanical strength of the finally obtained polyimide composite is sufficient, There is no practical problem. Moreover, if it is the said range, since it becomes possible to satisfy | fill all the colorless transparency of the polyimide composite finally obtained, high heat resistance, and mechanical strength in a practical range, it is preferable.

The means for adding the europium (Eu) compound is not particularly limited. For example, the europium (Eu) compound may be added directly, but preferably, the europium (Eu) compound is finely pulverized and the pulverized product is added. Further, the europium (Eu) compound may be previously dissolved or dispersed in a solvent that does not react with the polyamic acid solution (S1) and then added to the polyamic acid solution (S1).

The mixing method of the europium (Eu) compound is not particularly limited, and can be mixed by a known apparatus such as a general mixer or blender under an inert atmosphere such as air or nitrogen.

The above mixing is preferably performed at around 0 to 50 ° C. from the viewpoint of suppressing imidization of the polyamic acid, more preferably at about 10 to 40 ° C., and it may be performed at room temperature because of operational advantages. Most preferred. The mixing time is not particularly limited, but is preferably in the range of 30 minutes to 24 hours, and more preferably in the range of 1 hour to 20 hours.

Further, for the purpose of removing impurities and insoluble components from the obtained polyamic acid solution (S2), filtration may be performed as necessary. The filtration can be performed, for example, by pressure filtration provided with PTFE (tetrafluoroethylene resin) filter paper.

For example, additives and fillers may be further added to the polyamic acid solution (S2) thus obtained within a range not impairing the effects of the present invention.
Examples of additives include wear resistance improvers such as graphite, carborundum, molybdenum disulfide, and fluorine-based resins, flame retardant improvers such as antimony trioxide, phosphazene compounds, and phosphate esters, clay, mica, Electrical property improvers such as kaolin, tracking resistance improvers such as asbestos, silica and graphite, acid resistance improvers such as silica and calcium metasilicate, heat conductivity improvers such as iron powder, zinc powder and aluminum powder, etc. Examples thereof include glass beads, glass spheres, glass fibers, talc, diatomaceous earth, alumina, hydrated alumina, titania, shirasu balloons, colorants, and pigments.

(Polyamide acid composite)
When the solvent is removed under the condition that the polyamic acid contained in the polyamic acid solution (S2) is not imidized, a polyamic acid composite (PAAC) can be produced.

Examples of the method for removing the solvent include a reprecipitation method in which a poor solvent that does not dissolve the polyamic acid complex (PAAC) is added to the polyamic acid solution (S2) to precipitate the polyamic acid complex (PAAC), And a vacuum drying method in which the solvent is volatilized and distilled off under reduced pressure.

<Polyimide composite>
(Polyimide)
The polyimide contained in the colorless and transparent polyimide composite of the present invention has a semi-alicyclic repeating structure represented by the following general formula (2).

(In formula (2), X represents a divalent alicyclic group having 4 to 15 carbon atoms, and Y represents a tetravalent aromatic group having 6 to 27 carbon atoms).

As described above, the polyimide having the repeating structure represented by the above formula (2) is obtained by reacting the divalent alicyclic diamine compound (A) with the tetravalent aromatic tetracarboxylic dianhydride (B). It is formed.

In addition, when the polyimide of the present invention is a copolymer, the ordering and regularity of two or more kinds of repeating units constituting the copolymer may or may not be limited. The type can be random, alternating, or block. Therefore, when the diamine compound (A) and the tetracarboxylic dianhydride (B) are composed of 3 or more types, the order of addition is arbitrary, and the method for adding these raw materials can be either batch or divided. It is.

In the present invention, X and Y in the above formula (2) preferably have the following structural units because they are excellent in colorless transparency, high heat resistance and mechanical strength of the polyimide composite of the present invention. .

X in the above formula (2) is

At least one alicyclic group selected from the group consisting of:
Y in the above formula (2) is

At least one aromatic group selected from the group consisting of:

In the present invention, a polyimide containing any one of the following general formulas (3) to (11) is more preferable because the fluorescence intensity is high even if the fluorescence wavelength derived from europium is the same.

In general formula (3), diamine compound [1] is norbornanediamine, and compound [2] is obtained from 1,2,4,5-pyromellitic dianhydride.

In the general formula (4), the diamine compound [1] is trans-1,4-cyclohexyldiamine, and the compound [2] is obtained from 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride.

In general formula (5), diamine compound [1] is 1,4-bis (aminomethyl) cyclohexane, and compound [2] is obtained from 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride. It is done.

In the general formula (6), the diamine compound [1] is trans-1,4-cyclohexyldiamine and norbornanediamine, and the compound [2] is from 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride. can get.

(In the formula, m and n represent the number of repeating structural units represented in parentheses, and the ratio of the average value of m to the average value of n (m: n) is 1: 9 to 9: 1)
In the general formula (7), the diamine compound [1] is 4,4′-methylenebis (cyclohexylamine), and the compound [2] is obtained from 1,2,4,5-pyromellitic dianhydride.

In the general formula (8), the diamine compound [1] is norbornanediamine, and the compound [2] is obtained from bis (3,4-dicarboxyphenyl) ether dianhydride.

In the general formula (9), the diamine compound [1] is norbornanediamine, and the compound [2] is 2,2-bis (3,4-dicarboxyphenyl) -1,1,1,3,3,3- Obtained from hexafluoropropane dianhydride.

In the general formula (10), the diamine compound [1] is norbornanediamine and oxanorbornanediamine, and the compound [2] is 2,2-bis (3,4-dicarboxyphenyl) -1,1,1, Obtained from 3,3,3-hexafluoropropane dianhydride.

(In the formula, m and n represent the number of repeating structural units represented in brackets: [] and brackets: (), and the ratio of m: n is 4: 6 to 9: 1. is there.)
In the general formula (11), the diamine compound [1] is norbornane diamine and isophorone diamine, and the compound [2] is 2,2-bis (3,4-dicarboxyphenyl) -1,1,1,3. , 3,3-hexafluoropropane dianhydride.

(In the formula, m and n represent the number of repeating structural units represented in brackets: [] and brackets: (), and the ratio of m: n is 5: 5 to 9: 1. is there.)
Among these, it is particularly preferable to include polyimide represented by the general formulas (3) to (6) from the viewpoint of balance between fluorescence intensity and mechanical intensity.

(Polyimide composite)
The polyimide composite of the present invention usually contains 0.001 to 10 equivalents of europium (Eu) with respect to 100 equivalents of the repeating unit of the polyimide represented by the above formula (2).

Also, the polyimide composite is colorless and transparent. Here, in the present invention, colorless and transparent means that when a film having a thickness of 30 μm is produced, the light transmittance is usually 80% to 100% at a wavelength of 400 nm or more, preferably 400 to 800 nm in the visible light region. Preferably, it means 85 to 100%. When the light transmittance is less than the above range, basically, a polyimide composite cannot be used as a material for a member requiring “colorless and transparent”.

The polyimide composite of the present invention usually emits fluorescence having a wavelength of 500 to 800 nm, preferably 550 to 700 nm instantaneously, for example, by irradiating with an ultraviolet ray having a wavelength of 250 to 400 nm. This fluorescence can usually be identified as red. Note that “instantaneous” means that fluorescence is emitted immediately upon irradiation with ultraviolet rays, and that the response to ultraviolet rays is fast. Furthermore, the polyimide composite has a very high fluorescence intensity.

Such an effect is obtained by the structure based on the carboxyl group substituted on the aromatic ring and europium (Eu), which is the polyamic acid side chain, formed in the polyamic acid solution (S2) by imidization and solvent removal. It is presumed to be caused by the fact that it is formed in the polyimide composite in a stronger form. Although the detailed mechanism formed by the structure is not necessarily clear, the reaction condition employed for imidization is a condensation reaction involving thermal or chemical dehydration, so the carboxyl group substituted on the aromatic ring and It is presumed that a structure based on europium (Eu) was formed more firmly in the polyimide composite. Therefore, the excitation energy for promoting the light emission by the ff transition of europium (Eu) is obtained through the optical antenna effect from the photoexcitation energy from the aromatic organic compound having the carboxyl group. Although the polyimide composite is colorless and transparent, for example, when irradiated with ultraviolet rays having a wavelength of 250 to 400 nm, it is possible to instantaneously emit fluorescence usually having a wavelength of 500 to 800 nm.

The polyimide composite of the present invention is excellent in heat resistance and preferably has a Tg of 200 ° C. or higher, more preferably 250 ° C. or higher.
The polyimide composite obtained by the present invention can maintain excellent mechanical properties and dimensional stability by compounding a europium compound with an addition amount within a suitable range. Preferably, the increase or decrease in the coefficient of thermal expansion (CTE) is suppressed in the range of −5 to +5 ppm, more preferably in the range of −3 to +3 ppm, and the tensile test, compared to the polyimide alone with no europium compound added. The increase / decrease in the tensile elongation at is in the range of −10 to + 10%, more preferably in the range of −5 to + 5%, and the above colorless transparency and high fluorescence can be efficiently imparted.

(Preparation of polyimide composite)
The polyimide composite of the present invention can be produced by imidizing the polyamic acid contained in the polyamic acid solution (S2) and removing the solvent simultaneously with or after the imidization. In addition, if the solvent cannot be sufficiently removed even if the solvent is removed simultaneously with imidization, the solvent may be further removed following imidization. In addition, it can replace with the said polyamic-acid solution (S2), and can also produce a polyimide composite body by the same operation using the varnish containing the said polyamic acid.

As the imidization, a known method can be employed, and examples thereof include thermal imidization and chemical imidization. A plurality of these imidization means may be combined to imidize. The thermal imidization is usually carried out by heating at a temperature of 150 to 300 ° C., preferably 200 to 300 ° C., for 30 minutes to 4 hours. If it is the said range, the imide ring formation by a dehydration condensation reaction can be completed more and it is preferable from the point which can suppress the coloring of a polyimide composite_body | complex more. Chemical imidization is performed with an imidizing agent such as acetic anhydride. The atmosphere at the time of imidation is not particularly limited, and for example, imidization can be performed under an inert atmosphere such as air or nitrogen.

The solvent can be removed by, for example, heating and further reducing the pressure as necessary.
The conditions for solvent removal vary depending on the solvent species and are not particularly limited, but are usually performed by heating at a temperature of 150 to 300 ° C. for 30 minutes to 4 hours. The heating atmosphere at this time is not particularly limited, and for example, the solvent can be removed under an inert atmosphere such as reduced pressure, air, or nitrogen.

When imidation is performed by thermal imidization, for example, the solvent may be removed simultaneously with the heating. If the solvent cannot be removed sufficiently during the imidation reaction, the solvent can be removed usually by reheating at a temperature of 150 to 300 ° C.

In the case of imidization by chemical imidization, for example, after chemical imidation, the solvent can be removed by heating at a temperature of usually 150 to 300 ° C. for 30 minutes to 4 hours.
The polyimide composite of this invention is obtained by such imidation, The polyimide contained in the polyimide composite contains the repeating unit shown by the said Formula (2).

<Application>
The polyimide composite of the present invention can be used for members and materials that require colorless transparency, high heat resistance, high mechanical strength, high fluorescence, wavelength conversion, excellent electrical properties, etc. Widely used in optical communication, photonics, electronics, flat panel displays including liquid crystal displays and organic EL displays, flexible displays and light emitting displays, fluorescent paints, security inks, lighting fixtures, solar power generation, radiation sensors, and agricultural films Can be applied.

For example, by coating the solar cell panel with the polyimide composite of the present invention as a wavelength conversion material, energy in the ultraviolet region can also be converted, and an efficient battery can be obtained. In the field of LEDs, a color excellent in color purity can be directly emitted from the polyimide composite of the present invention.

Also, the polyimide composite of the present invention can be used for, for example, a molded body such as a film, a rigid including a metal laminated plate, a flexible circuit substrate, a reflector, and the like. In addition, the conditions for manufacturing these molded bodies can be appropriately set according to the thickness of the film, the shape of the molded body, and the like.

(the film)
The polyimide composite of the present invention can be used as, for example, a film, a metal laminate having at least one layer composed of the polyimide composite, and the like. The film is colorless and transparent. For example, wavelength conversion films, optical materials, photosensitive resin cover materials, display material members such as displays and flexible displays, rigid and flexible circuit boards that require transparency, solar cells, etc. It can be used for protective films, agricultural films for promoting photosynthesis and crop growth.

The film of the present invention is not particularly limited, but usually has a thickness of several μm to several hundred μm. A film having such a thickness is obtained by, for example, applying a coating material containing a polyamic acid solution (S2) or a polyamic acid composite (PAAC) at a thickness of 10 to 1000 μm, imidizing, and removing the solvent. Can be made. The concentration of the coating material, the content of other components, and the like can be set as appropriate depending on the application.

EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, this invention is not restrict | limited at all by these.
<Test method>
Test methods for various tests common to the examples are as follows.

(1) Intrinsic logarithmic viscosity of polymer solution Among polymers, N, N-dimethylacetamide (DMAc), 1-methyl-2-pyrrolidone (NMP), 1,3-dimethyl-2-imidazolidinone (DMI) The same solvent as that used in the synthesis was used for dissolution, and a polymer solution was prepared so as to have a solid concentration of 0.5 dL / g, and measurement was performed at 35 ° C. using an Ubbelohde viscometer.

(2) Total light transmittance Using a HZ-2 (TM double beam system) manufactured by Suga Test Instruments Co., Ltd. equipped with an integrating sphere, measurement was performed with an aperture diameter of 20 mm and a light source of D65.

(3) Measurement of fluorescence spectrum Using FP-6600 manufactured by JASCO Corporation, the fluorescence spectrum at the maximum excitation wavelength is 250 to 800 nm while scanning the range of excitation light: 220 to 600 nm at a scan speed of 5000 nm / min. Obtained in the range. The PMT voltage at this time: 550 V, spectrum correction was performed with rhodamine B, and the fluorescence intensity at the obtained maximum fluorescence wavelength was measured.

(4) Glass transition temperature (Tg) and coefficient of thermal expansion (CTE)
Using a TMA-50 type manufactured by Shimadzu Corporation, measurement was performed under an air stream at a temperature rising rate of 10 ° C./min and a load of 14 g / mm ² . The coefficient of thermal expansion was measured in the range of 100 to 200 ° C.

(5) Tensile elongation test A dumbbell punched specimen with a marked line width of 5 mm was prepared and used to break until it reached a tensile speed of 30 mm / min using an EZ-S tensile tester manufactured by Shimadzu Corporation. The stress-strain curve was obtained by measuring the stress and elongation. The measurement was obtained as an average value of 10 times.

<Raw materials and solvents>
The reagents used in the following synthesis examples, examples, reference examples, and comparative examples are as follows.
(A) Europium compound Europium chloride hexahydrate (EuCl ₃ , manufactured by Tokyo Chemical Industry Co., Ltd.)
Europium nitrate hexahydrate (Eu (NO ₃ ) ₃ , manufactured by STREM CHEMICAL)
Europium acetate hydrate (Eu (OOCCH ₃ ) ₃ , manufactured by Alfa Aesar)
(B) Polyimide raw material (a) Diamine compound NBDA: Norbornanediamine (Compound 1)
H-XDA: 1,4-bis (aminomethyl) cyclohexane (compound 2)
tCHDA: trans-1,4-cyclohexyldiamine (compound 3)
ONDA: oxanorbornanediamine (compound 4)
IPDA: Isophoronediamine (Compound 5)
H-MDA: 4,4′-methylenebis (cyclohexylamine) (Compound 6)
ODA: 4,4′-diaminodiphenyl ether [4,4′-oxydianiline] (Compound 7)
APB: 1,3-bis (3-aminophenoxy) benzene (Compound 8)
mBP: 4,4′-bis (3-aminophenoxy) biphenyl (Compound 9)
(B) Tetracarboxylic dianhydride PMDA: pyromellitic dianhydride (Compound 10)
BPDA: 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (Compound 11)
ODPA: Bis (3,4-dicarboxyphenyl) ether dianhydride (Compound 12)
6FDA: 2,2-bis (3,4-dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane dianhydride (Compound 13)
H-PMDA: 1,2,4,5-cyclohexanetetracarboxylic dianhydride (Compound 14)

(C) Solvent • N, N-dimethylacetamide (DMAc, manufactured by Wako Pure Chemical Industries)
・ 1-Methyl-2-pyrrolidone (NMP, manufactured by Wako Pure Chemical Industries)
・ 1,3-Dimethyl-2-imidazolidinone (DMI, manufactured by Wako Pure Chemical Industries)

<Polyamide acid polymerization and creation of polyimide film>
(Synthesis Example 1)
In a 1 L 5-neck separable flask equipped with a thermometer, stirrer, nitrogen inlet tube and dropping funnel, 153 g (0.700 mol) of pyromellitic dianhydride (PMDA) and N, N-dimethylacetamide as an organic solvent (DMAc) 420 g was added and stirred in an ice water bath at 0 ° C. to obtain a slurry liquid. 108 g (0.700 mol) of norbornanediamine (NBDA) charged in the dropping funnel and 188 g of N, N-dimethylacetamide (DMAc) were slowly added dropwise over 2 hours. After completion of the dropwise addition, the mixture was further stirred at room temperature for 16 hours to obtain a polyamic acid varnish. The intrinsic log viscosity of this polyamic acid was 0.69 dL / g. The results are shown in Table 1.

The obtained polyamic acid solution was cast on a glass substrate using a doctor blade. This was transferred to an inert oven, heated from 50 ° C. to 270 ° C. in a nitrogen stream over 2 hours, and then kept at 270 ° C. for 2 hours to have a self-supporting colorless transparent polyimide with a film thickness of 26 μm. A film was obtained. Table 2 shows the measurement results of various physical properties (total light transmittance, maximum excitation wavelength, maximum fluorescence wavelength and intensity, glass transition temperature, thermal linear expansion coefficient, and tensile elongation) of this polyimide film.

(Synthesis Example 2)
In a 1 L five-necked separable flask equipped with a thermometer, a stirrer, and a nitrogen introduction tube, 35.6 g (0.250 mol) of 1,4-bis (aminomethyl) cyclohexane (H-XDA), 3,3 ′ , 4,4′-biphenyltetracarboxylic dianhydride (BPDA) 73.5 g (0.250 mol) and solvent N, N-dimethylacetamide (DMAc) 620 g were added at room temperature, and the reaction vessel was kept at 100 ° C. Bathed in an oil bath for 10 minutes. It was confirmed that salt precipitation occurred in about 5 minutes, and it was quickly redissolved and thickened. After removing the oil bath, the mixture was further stirred at room temperature for 18 hours to obtain a polyamic acid varnish. The intrinsic logarithmic viscosity of the obtained polyamic acid was 1.22 dL / g (35 ° C., 0.5 g / dL). The results are shown in Table 1.
A colorless transparent polyimide film was produced in the same manner as in Synthesis Example 1, and the measurement results of various physical properties of the obtained film are shown in Table 2.

(Synthesis Example 3)
A polyamic acid solution and a colorless transparent polyimide film were prepared in the same manner as in Synthesis Example 2 except that H-XDA was changed to 57.1 g (0.500 mol) of trans-1,4-cyclohexyldiamine (tCHDA). The measurement results of various physical properties are shown in Tables 1 and 2.

(Synthesis Example 4)
A polyamic acid solution and a colorless transparent polyimide film were prepared in the same manner as in Synthesis Example 1 except that NBDA was changed to 105 g of 4,4′-methylenebis (cyclohexylamine) (H-MDA). Tables 1 and 2 show.

(Synthesis Examples 5 and 6)
PMDA was 155 g of bis (3,4-dicarboxyphenyl) ether dianhydride (ODPA), 2,2-bis (3,4-dicarboxyphenyl) -1,1,1,3,3,3- A polyamic acid solution and a colorless transparent polyimide film were prepared in the same manner as in Synthesis Example 1 except that the amount was changed to 222 g of hexafluoropropane dianhydride (6FDA), and the results of various physical properties are shown in Tables 1 and 2.

(Synthesis Examples 7 and 8)
A polyamic acid solution was prepared in the same manner as in Synthesis Example 1 except that the diamine component was NBDA alone, but was changed to a copolymer of 50 mol% oxanorbornane diamine (ONDA), 30 mol% isophorone diamine (IPDA) and NBDA, respectively. A colorless transparent polyimide film was prepared, and the measurement results of various physical properties are shown in Tables 1 and 2.

(Synthesis Example 9)
In a 300 mL five-necked separable flask equipped with a thermometer, a stirrer and a nitrogen inlet tube, 11.4 g (0.100 mol) of trans-1,4-cyclohexyldiamine (tCHDA) and N-methylpyrrolidone (0.100 mol) as a solvent NMP) (149 g) was added and stirred. To the transparent solution, 2,5.9 g (0.0880 mol) of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (BPDA) was charged in powder form, and the reaction vessel was placed at 120 ° C. And bathed in an oil bath maintained for 5 minutes. It was confirmed that the salt precipitated after a while after the BPDA was charged, and then rapidly redissolved and thickened. After removing the oil bath, the mixture was further stirred at room temperature for 18 hours to obtain an oligoamidic acid varnish having an amino group derived from tCHDA at the terminal.

Subsequently, 6.19 g (0.0402 mol) of norbornanediamine (NBDA) and 1,3-dimethyl-2-imidazolidinone were added to a 200 mL 5-neck separable flask equipped with a thermometer, a stirrer, and a nitrogen introduction tube. (DMI) 64.5 g was added and stirred. To the transparent solution, 15.3 g (0.0522 mol) of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (BPDA) was charged in powder form, and the reaction vessel was placed at 120 ° C. And bathed in an oil bath maintained for 5 minutes. After the BPDA was charged, the salt temporarily precipitated, but it was confirmed that it immediately re-dissolved and became a homogeneous transparent solution. A cooling tube and a Dean-Stark type concentrator were attached to the separable flask, 15 g of xylene was added to the reaction solution, and dehydration thermal imidization reaction was carried out at 180 ° C. with stirring for 4 hours. After distilling off xylene, an oligoimide varnish having a terminal BPDA-derived acid anhydride structure was obtained.

The oligoamido acid varnish and oligoimide varnish obtained above were mixed and stirred while diluting to 15 wt% by adding NMP to synthesize a multi-block polyamic acid imide varnish. The inherent logarithmic viscosity of the obtained varnish was 1.31 dL / g (35 ° C., 0.5 g / dL). The results are shown in Table 1.
A colorless transparent polyimide film was produced in the same manner as in Synthesis Example 1, and the measurement results of various physical properties of the obtained film are shown in Table 2.

(Synthesis Examples 10, 12, and 14)
The diamine component NBDA is 146 g (0.500 mol) of 1,3-bis (3-aminophenoxy) benzene (APB), solvent DMI 602 g, 4,4′-diaminodiphenyl ether [4,4′-oxydianiline] (ODA) 100 g (0.500 mol) of the solvent NMP 494 g, 4,4′-bis (3-aminophenoxy) biphenyl (mBP) 184 g (0.500 mol) was changed to the solvent DMI 690 g, Except for changing the PMDA of the acid anhydride component to 112 g (0.500 mol) of 1,2,4,5-cyclohexanetetracarboxylic dianhydride (H-PMDA), A polyamic acid solution and a colorless transparent polyimide film were prepared, and the measurement results of various physical properties are shown in Tables 1 and 2.

(Synthesis Examples 11, 13, and 15)
Each of the polyamic acid varnishes obtained in Synthesis Examples 10, 12, and 14 was poured into a flask equipped with a condenser and a Dean-Stark type concentrator, and 20 wt% of xylene was added as an azeotropic agent. A time azeotropic dehydration reaction was carried out, and finally xylene was distilled off to obtain a polyimide varnish. Table 1 shows the intrinsic logarithmic viscosity results of the obtained polyimide.
A colorless transparent polyimide film was produced in the same manner as in Synthesis Example 1, and the measurement results of various physical properties of the obtained film are shown in Table 2.

(Synthesis Examples 16 and 17)
The diamine component H-XDA was converted into 146 g (0.500 mol) of 1,3-bis (3-aminophenoxy) benzene (APB) and 166 g of 4,4′-bis (3-aminophenoxy) biphenyl (mBP), respectively. 0.450 mol) and 4,4′-diaminodiphenyl ether [4,4′-oxydianiline] (ODA) (10.0 g, 0.0500 mol) are added with tetracarboxylic dianhydride component BPDA. A polyamic acid solution and a polyimide film were prepared in the same manner as in Synthesis Example 2 except that the pyromellitic dianhydride (PMDA) was changed to 109 g (0.500 mol). Tables 1 and 2 show the measurement results of various physical properties. Shown in

(Synthesis Example 18)
The diamine component H-XDA was added to 57.1 g (0.500 mol) of trans-1,4-cyclohexyldiamine (tCHDA), and the tetracarboxylic dianhydride component BPDA was added to 1,2,4,5- A polyamic acid solution and a colorless transparent polyimide film were prepared in the same manner as in Synthesis Example 2 except that 112 g (0.500 mol) of cyclohexanetetracarboxylic dianhydride (H-PMDA) was changed. Shown in 1 and 2.
(Synthesis Example 19)
In a 500 mL 5-neck separable flask equipped with a thermometer, a stirrer, and a nitrogen inlet tube, 35.6 g (0.178 mol) of 4,4′-diaminodiphenyl ether [4,4′-oxydianiline] (ODA) And 267 g of N, N-dimethylacetamide (DMAc) as an organic solvent was added and stirred in an ice water bath at 0 ° C. to obtain a uniform solution. Thereto was powdered 78.9 g (0.178 mol) of 2,2-bis (3,4-dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane dianhydride (6FDA). The mixture was charged in the form of a solid and stirred at room temperature for 16 hours to obtain a polyamic acid varnish. The intrinsic log viscosity of this polyamic acid was 0.98 dL / g. The results are shown in Table 1. The polyimide film was prepared in the same manner as in Synthesis Example 1, and the measurement results of various physical properties are shown in Table 2.

(Examples 1, 3, 6 to 11 and 13)
The polymer solution (polyamic acid varnish or polyamic acid imide varnish) obtained in Synthesis Examples 1 to 9 is 1.0 part by weight with respect to 100 parts by weight of the solid content of the corresponding polyamic acid or polyamic acid imide. Europium chloride hexahydrate was added as described above, and the mixture was stirred for 5 minutes using a rotation / revolution mixer (or kneading / mixing foam removing device) (manufactured by Keyence Corporation, product name: Hybrid Mixer-500), and the corresponding composite A varnish was obtained. The varnish is cast on a glass substrate using a doctor blade, transferred to an inert oven, heated from 50 ° C. to 270 ° C. over 2 hours in a nitrogen stream, and then further heated at 270 ° C. at 2 A polyimide composite film having self-supporting property and colorless transparency was obtained by maintaining for a while.
Table 3 shows the measurement results of various physical properties (total light transmittance, maximum excitation wavelength, maximum fluorescence wavelength and intensity, glass transition temperature, thermal expansion coefficient, and tensile elongation) of the polyimide composite film.

(Examples 2 and 12)
The europium chloride hexahydrate was added to the polymer solution (polyamic acid varnish) obtained in Synthesis Examples 2 and 9 so that the corresponding solid content of the polyamic acid was 100 parts by weight to 0.20 part by weight. A corresponding composite varnish and a polyimide composite film having self-supporting property and colorless transparency were produced in the same manner as in Example 1 except that the addition amount was changed. Table 3 shows the measurement results of various physical properties.

Example 4
The amount of europium nitrate hexahydrate added to the polymer solution (polyamic acid varnish) obtained in Synthesis Example 2 was changed to 1.0 part by weight with respect to 100 parts by weight of the solid content of the polyamic acid. Except that, a composite varnish and a polyimide composite film having self-supporting property and colorless transparency were produced in the same manner as in Example 3. Table 3 shows the measurement results of various physical properties.

(Example 5)
The amount of europium acetate hydrate added to the polymer solution (polyamic acid varnish) obtained in Synthesis Example 2 was changed to 1.0 part by weight with respect to 100 parts by weight of the solid content of the polyamic acid. Except for the above, a composite varnish and a polyimide composite film having self-supporting property and colorless transparency were produced in the same manner as in Example 3. Table 3 shows the measurement results of various physical properties.

(Reference Examples 1 and 2)
The polymer solution (polyamic acid varnish or polyamic acid imide varnish) obtained in Synthesis Examples 2 and 9 is 5.0 parts by weight with respect to 100 parts by weight of the solid content of the corresponding polyamic acid or polyamic acid imide. A corresponding composite varnish and a polyimide composite film having self-supporting property and colorless transparency were prepared in the same manner as in Example 1 except that the addition amount of europium chloride hexahydrate was changed. Table 4 shows the measurement results of various physical properties.

(Comparative Examples 1 to 9)
The polymer solutions (polyamic acid varnish or polyimide varnish) obtained in Synthesis Examples 10 to 18 were chlorinated so as to be 1.0 part by weight with respect to 100 parts by weight of the solid content of the corresponding polyamic acid or polyimide. Corresponding composite varnish and polyimide composite film were prepared in the same manner as in Example 1 except that the amount of europium hexahydrate added was changed. Table 5 shows the measurement results of various physical properties.

(Comparative Example 10)
A colorless transparent polyimide film obtained in Synthesis Example 2 above was spin-coated with a 3% acetonitrile solution of europium nitrate hydrate and dried at room temperature. Various physical properties were measured. The results are shown in Table 5.

(Comparative Example 11)
A colorless transparent polyimide film obtained in Synthesis Example 2 above was immersed in a 3% acetonitrile solution of europium nitrate hydrate for 6 hours and dried at room temperature, and the film was dried in the same manner as in Example 1. Various physical properties were measured. The results are shown in Table 5.
(Comparative Example 12)
The amount of europium nitrate hexahydrate added to the polymer solution (polyamic acid varnish) obtained in Synthesis Example 19 was changed to 1.0 part by weight with respect to 100 parts by weight of the solid content of the polyamic acid. A polyimide composite film having a corresponding composite varnish and self-supporting property was produced in the same manner as in Example 1 except that. Table 5 shows the measurement results of various physical properties.

As shown in the examples of Table 3, when the components of polyimide diamine compound / tetracarboxylic dianhydride are alicyclic / aromatic, the produced composite film is colorless and transparent, but excited. Fluorescence derived from a europium compound showing a maximum light emission value at a wavelength of 615 nm by light irradiation was observed. Since the scanning speed at this time was 5000 nm / min, it was found that the fluorescence emission had high-speed response.

Further, as shown in the reference example of Table 4, even when the polyimide has the same structure as Table 3, the addition amount of the europium compound was prepared from varnish with 5 parts by weight added to 100 parts by weight of the polymer. In the case of a composite film, although the fluorescence intensity and film properties are slightly lower than those of a composite film prepared from a varnish to which 1 part by weight of the europium compound is added, it still has colorless transparency and fast response fluorescence. I found out.

On the other hand, as shown in Comparative Example in Table 5, when the polyimide diamine compound / tetracarboxylic dianhydride component is aromatic / alicyclic or alicyclic / alicyclic, the composite film is colorless. Although it has transparency, no fluorescence (wavelength around 615 nm) derived from a europium compound was observed even when irradiated with excitation light. When the polyimide diamine compound / tetracarboxylic dianhydride component is aromatic / aromatic, the composite film is colored yellow or brown, and the fluorescence derived from the additive even when irradiated with excitation light. The intensity (wavelength near 615 nm) was extremely small, and the fluorescence was not confirmed visually due to the color of the composite film itself. In particular, as shown in Comparative Example 12, even when the composition is the same as that of Patent Document 2, it is clear that no fluorescence is exhibited when the scan speed is high (5000 nm / min) as in this measurement. It was.

In addition, the colorless transparent polyimide film obtained in Synthesis Example 2 was spin-coated with a 3% acetonitrile solution of europium nitrate hydrate, or the film immersed in the solution for 6 hours was dried at room temperature. In the thing, even if it irradiates excitation light, the fluorescence intensity (wavelength 615nm vicinity) derived from a europium compound was not confirmed. Thereby, in order to give interaction between a colorless and transparent polyimide and a europium compound, it turned out that the composite in the state of the polyamic-acid varnish of a polyimide precursor is required.

1 Example 3
2 Example 2
3 Reference Example 1
4 Synthesis Example 2

Claims (13)

1. Obtained from the polyamic acid represented by the general formula (1) obtained from the alicyclic diamine compound (A) and the aromatic tetracarboxylic dianhydride (B), and the solvent (C) in which the polyamic acid is dissolved. To 100 parts by weight of the polyamic acid solution (S1)
   By adding 0.001 to 4 parts by weight of a europium (Eu) compound, a polyamic acid solution (S2) is obtained,
   A polyimide composite obtained by imidization of the polyamic acid contained in the polyamic acid solution (S2) and removal of the solvent (C).
   

   

   (In formula (1), X represents a divalent alicyclic group having 4 to 15 carbon atoms, and Y represents a tetravalent aromatic group having 6 to 27 carbon atoms.)
2. 2. The polyimide composite according to claim 1, wherein the polyimide contained in the polyimide composite includes a structural unit represented by the following general formula (2).
   

   

   In the formula (2), X is
   

   

   At least one alicyclic group selected from the group consisting of:
   Y is
   

   

   At least one aromatic group selected from the group consisting of:
3. 2. The polyimide composite according to claim 1, wherein the polyimide contained in the polyimide composite includes a structural unit represented by the following general formula (3).
   

   
4. 2. The polyimide composite according to claim 1, wherein the polyimide contained in the polyimide composite includes a structural unit represented by the following general formula (4).
   

   
5. The polyimide composite according to claim 1, wherein the polyimide contained in the polyimide composite includes a structural unit represented by the following general formula (5).
   

   
6. 2. The polyimide composite according to claim 1, wherein the polyimide contained in the polyimide composite includes a structural unit represented by the following general formula (6).
   

   

   (In the formula, m and n represent the number of repeating structural units represented in parentheses, and the ratio of the average value of m to the average value of n (m: n) is 1: 9 to 9: 1)
7. The polyimide composite according to any one of claims 1 to 6, wherein the europium (Eu) compound is at least one selected from europium chloride, europium nitrate, and europium acetate.
8. The polyimide composite according to any one of claims 1 to 7, wherein the polyimide composite emits fluorescence having a wavelength of 500 to 800 nm when irradiated with an ultraviolet ray having a wavelength of 250 to 400 nm.
9. The polyimide composite according to claim 8, wherein the total light transmittance is 80% or more.
10. A film comprising the polyimide composite according to any one of claims 1 to 9.
11. The manufacturing method of the polyimide composite characterized by including the following processes 1 to 3.
    (Step 1) The polyamic acid represented by the general formula (1) obtained from the alicyclic diamine compound (A) and the aromatic tetracarboxylic dianhydride (B), and the solvent (C A step of obtaining a polyamic acid solution (S1) obtained from
    

    

    (In formula (1), X represents a divalent alicyclic group having 4 to 15 carbon atoms, and Y represents a tetravalent aromatic group having 6 to 27 carbon atoms.)
    (Step 2) A step of adding 0.001 to 4 parts by weight of a europium (Eu) compound to 100 parts by weight of the polyamic acid to obtain a polyamic acid solution (S2), and (Step 3) the polyamic acid solution (S2 The process of obtaining a polyimide composite by imidation of the polyamic acid contained in), and solvent (C) removal.
12. A polyamic acid represented by the following general formula (1);
    

    

    (In formula (1), X represents a divalent alicyclic group having 4 to 15 carbon atoms, and Y represents a tetravalent aromatic group having 6 to 27 carbon atoms.)
    In the solvent (C) in which the polyamic acid is dissolved,
    A polyamic acid solution (S2) obtained by adding 0.001 to 4 parts by weight of a europium (Eu) compound to 100 parts by weight of the polyamic acid.
13. The polyamic acid solution (S2) according to claim 12, wherein the solvent (C) is an aprotic amide solvent.

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