TWI691491B - Tetracarboxylic acid dianhydride, polyamic acid and polyimide - Google Patents

Abstract

An object of the present invention is to provide a polyimide which is excellent in solvent solubility and exhibits a high refractive index.

The present inventor found that the above problem can be solved by a polyimide which is produced from a tetracarboxylic acid dianhydride having a fluorene skeleton, an ether group and an ester group represented by the following formula (1), which is not only excellent in solvent solubility and having a high refractive index, but also has excellent toughness in spite of having a rigid structure like a fluorene skeleton.

Description

Tetracarboxylic dianhydride, polyamic acid and polyimide

The present invention relates to a novel tetracarboxylic dianhydride having a stilbene group, an ether group and an ester group used as a raw material of polyimide resin, etc., and a polyamic acid obtained from the tetracarboxylic dianhydride and Polyimide.

Resin materials with high refractive index have higher processability than traditional glass materials. Therefore, they have been reviewed and widely used in the optics of spectacle lenses, cameras, etc., optical disc lenses, f θ lenses, and image display media. Components, optical films, films, substrates, various optical filters, tinctures, optical components for communications, etc. Examples of resins that exhibit high refractive index are also mentioned polyester, polycarbonate, polyacrylic Amines. Among them, polyimide is known as a resin excellent in heat resistance, and in the above-mentioned applications, polyimide having a high refractive index and excellent heat resistance is required particularly in the category requiring heat resistance.

However, most of the heat-resistant polyimide is insoluble in organic solvents, so the forming process of polyimide itself is generally not easy. Therefore, it must be formed into a film by using a polyamic acid solution of a polyimide precursor as a film, and then subjected to dehydration cyclization (imidization) by heating at a high temperature of 250 to 350°C. Polyimide film was obtained. However, the method of obtaining a polyimide film by imidization after forming a film with a polyamic acid solution, etc., is due to the process of cooling from the imidization temperature (250 to 350°C) to room temperature. The resulting thermal stress often causes problems such as curling, film peeling, and cracking, and there is a problem that a uniform polyimide film cannot be obtained. At the same time, a high-temperature furnace that requires more than 300°C during imidization will also be manufactured. The disadvantage of increased costs.

Therefore, a polyimide which is excellent in solvent solubility and exhibits a high refractive index has been proposed, for example, a polyimide obtained from an aromatic diamine compound having a naphthalene skeleton [Japanese Patent Application Publication No. 2010-070513 (Patent Literature 1)]. The polyimide described in this document is soluble in solvents and has a refractive index of about 1.63 which is a high refractive index. However, due to the high refractive index required for resin materials today, it is necessary to further increase the refractive index.

[Prior Technical Literature] [Patent Literature]

[Patent Literature 1] JP 2010-070513

The object of the present invention is to provide a polyimide with excellent solvent solubility and high refractive index.

In order to solve the above problems, the present inventors conducted various reviews of the tetracarboxylic dianhydride and diamine structures of polyimide raw materials, and found that a tetracarboxylic dianhydride having a stilbene skeleton represented by the following formula (1) was used. Made of Poly Acetylene imide has excellent solvent solubility and can express a high refractive index. Specifically, the present invention includes the following items.

[1] A tetracarboxylic dianhydride represented by the following formula (1),

[2] A polyamide having a repeating unit represented by the following formula (2).

(In the formula, Z represents a diamine residue.)

[3] A polyimide having a repeating unit represented by the following formula (3).

(In the formula, Z represents a diamine residue.)

[4] A method for producing tetracarboxylic dianhydride as described in [1], which comprises trimellitic anhydride halide and the following formula (4):

The bisphenol reaction shown.

The polyimide produced by using the tetracarboxylic dianhydride having a stilbene skeleton of the present invention has the characteristics of excellent solvent solubility and high refractive index. And it has the following features: Although it has a rigid structure such as a skeleton, its toughness is still excellent, so it can be used not only in lenses of eyeglasses, cameras, etc., optical discs, f θ lenses, image display media, optical components, and optical films. , Film, various optical filters, 珜鏡, communication optical components and other optical systems, also suitable for use in electronic materials such as flexible printed circuit boards, protective films for semiconductor elements, interlayer insulating films for integrated circuits, And replace the general use of flexible substrates for glass substrates such as liquid crystal displays, electronic paper, solar cells, etc.

Fig. 1 is a ¹ H-NMR spectrum of tetracarboxylic dianhydride represented by formula (1).

FIG. 2 is a ¹³ C-NMR spectrum of tetracarboxylic dianhydride represented by formula (1).

Figure 3 is a mass analysis diagram of tetracarboxylic dianhydride represented by formula (1).

<Method for producing tetracarboxylic dianhydride represented by formula (1)>

As a method for obtaining the tetracarboxylic dianhydride represented by the above formula (1), generally known methods can be suitably used. For example: in the presence of a deoxidizer (base), the compound represented by the above formula (4) (9,9-bis(4-(4-hydroxyphenyloxy)phenyl) stilbene, hereinafter, may also be abbreviated as BPOPF) The method of the reaction of the halide with trimellitic anhydride (acid halogen method); the method of BPOPF and the trimellitic anhydride through direct dehydration reaction; the deacetation reaction of the diacetate body of BPOPF and the trimellitic anhydride at high temperature Method; using dehydrating agent such as dicyclohexylcarbodiimide to dehydrate BPOPF and trimellitic anhydride; using toluenesulfonyl chloride/N,N-dimethylformamide/pyridine mixture The method of activating acid anhydride to esterify BPOPF. Among them, since the raw material trimellitic acid halide can be obtained inexpensively, the acetyl halide method is preferred. The halogen method will be described in detail below.

The acyl halide method specifically means that in the presence of a deoxidizer, BPOPF is reacted with an acyl halide of trimellitic anhydride represented by the following formula (5) to obtain the tetracarboxylic dianhydride represented by the above formula (1) Reaction (hereinafter, this reaction is also called esterification reaction.).

BPOPF used as a raw material can be a commercially available product, and can be manufactured by a generally known method (for example, International Publication No. 2006/052001 and Japanese Patent Laid-Open No. 2015-182970). Specifically, it can be prepared by reacting stilbene with p-phenoxyphenol in the presence of an acid.

The acyl halide of trimellitic anhydride used in the esterification reaction has a structure represented by the following formula (5),

(In the formula, Y represents a halogen atom.) Among the halides of trimellitic anhydride, since the halides of trimellitic anhydride can be obtained inexpensively, Y is preferably a chlorine atom.

The amount of phthalic anhydride of trimellitic anhydride shown in the above formula (5) used in the esterification reaction is usually 2 to 4 times the molar ratio, and 2 to 3 times the molar ratio with respect to 1 molar BPOPF Better. A sufficient reaction rate can be obtained when the use amount of phthalic anhydride is more than 2 times mole, and when the use amount is less than 4 times mole, the unreacted benzene trimer represented by the above formula (5) can be reduced As the acid halide, as a result, the purity of the obtained tetracarboxylic dianhydride represented by the above formula (1) can be improved.

Examples of the deoxidizer used in the esterification reaction include organic tertiary amines such as pyridine, triethylamine, N,N-dimethylaniline, and epoxy resins such as propylene oxide and allyl epoxypropyl ether. Inorganic bases such as potassium carbonate and sodium hydroxide. One type of these deoxidizers may be used, or two or more types may be used in combination as needed. Among these deoxidizers, pyridine is suitable because it is inexpensive and easy to separate and remove after the reaction. The amount of deoxidizer used is usually 2 to 4 times moles, and preferably 2 to 3 times moles relative to 1 mole of BPOPF. When the amount of deoxidizer used is 2 times more moles, the reaction rate can be increased, and when it is less than 4 times moles, the formation of impurities can be suppressed.

When performing esterification reaction, organic solvent Agent. Examples of organic solvents that can be used include ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, and ethers such as 1,2-dimethoxyethane, tetrahydrofuran, and cyclopentyl methyl ether. Aromatic hydrocarbons such as benzene, toluene and xylene, halogenated aromatic hydrocarbons such as chlorinated benzene and dichlorobenzene, nitriles such as acetonitrile, propionitrile, butyronitrile, isobutyronitrile, valeronitrile, isovaleronitrile and benzonitrile . From the viewpoint of acquisition and operability, ethers, aromatic hydrocarbons, and nitriles are preferred, and one or more of these organic solvents may be used in combination. The usage amount of these solvents when used is generally 1 to 30 parts by weight relative to 1 part by weight of BPOPF, preferably 1 to 5 parts by weight.

The esterification reaction is usually carried out at -10°C to 110°C, preferably -5°C to 80°C, more preferably 20°C to 70°C. By making the reaction temperature below 110°C, by-products can be reduced, and when the reaction temperature becomes above -10°C, a sufficient reaction rate can be obtained.

Examples of the esterification reaction are: in the solution of the mixture of the phthalic anhydride of trimellitic anhydride and the solvent shown in the above formula (5), while stirring the solution, in addition, a solution prepared by mixing BPOPF and a deoxidizer in the solvent After the exhaustion or continuous addition in the above temperature range, the method of continuing the reaction in the above temperature range. Alternatively, it may be a solution obtained by mixing the halogen of trimellitic anhydride and BPOPF represented by the above formula (5) in a solvent, directly using a deoxidizer, or after being mixed in a solvent, and then exhausting at the above temperature range or Continuous addition. After addition, continue the reaction at the above temperature range.

After the esterification reaction is completed, the reactant is cooled to 15°C to 35°C to precipitate crystals, and the crystals obtained by filtering the precipitated crystals are washed by a solvent that can be used in the foregoing reaction to obtain the above formula (1) Show Of tetracarboxylic dianhydride (hereinafter, this step is sometimes referred to as a crystallization step). The obtained tetracarboxylic dianhydride represented by the above formula (1) may be subjected to general purification such as adsorption treatment and recrystallization, if necessary.

At the same time, after the esterification reaction is completed, before performing the above crystallization step, if necessary, after adding water and an organic solvent separated from water to the reactant, the water layer is separated by stirring (hereinafter, there are Is called water washing step), extract the tetracarboxylic dianhydride represented by the above formula (1) in the organic solvent layer, and remove the excess amount of the deoxidizer and the hydrolysate of trihalomide anhydride, and the deoxidizer After the water layer divided by the halogen salt is removed, the by-product ring-opening body (hydrolysate of tetracarboxylic dianhydride represented by the above formula (1)) in the water washing step is cyclized in the presence of an organic solvent and acetic anhydride, The step of forming the tetracarboxylic dianhydride represented by the above formula (1) is performed again.

Obtained by the above method, the tetracarboxylic dianhydride represented by the above formula (1) can be used not only as a raw material for polyimide, but also as a raw material for resins such as polyester, additives, and hardeners for epoxy resins and polyurethane resins Wait for use. In addition, the purity of the tetracarboxylic dianhydride represented by the above formula (1) can be easily increased by the degree of polymerization of the polyamic acid represented by the above formula (2) or the polyimide represented by the above formula (3) From a point of view, the HPLC purity measured by the method described below is preferably 95% or more, and particularly preferably 99% or more.

<Polyamide having the repeating unit represented by the above formula (2) and its production method>

Hereinafter, a polyamic acid having a repeating unit represented by the above formula (2) (hereinafter, sometimes referred to as the polyamic acid of the present invention) will be described in detail.

The polyamic acid of the present invention has a repeating unit represented by the above formula (2), and the diamine residue represented by Z in the above formula (2) represents the tetracarboxylic dianhydride represented by the above formula (1) and is described later During the reaction of the diamines, the obtained diamine has a structure other than the amine group (-NH ₂ ).

The molecular weight of the polyamic acid of the present invention is preferably from 10,000 to 700,000, and more preferably from 20,000 to 600,000 using the weight average molecular weight obtained by the measurement method described later. When the molecular weight of the polyamic acid is 10,000 or more, it is possible to form, and it is easy to maintain good mechanical properties. In addition, when the molecular weight of the polyamic acid is 700,000 or less, it is easy to control the molecular weight during synthesis, and in many cases, it is easy to obtain a solution with an appropriate viscosity and the operation is easy. In addition, the molecular weight of the polyamic acid can be an indicator of the viscosity of the polyamic acid solution.

The polyamic acid of the present invention can be prepared by adding the powder of the tetracarboxylic dianhydride represented by the above formula (1) at 10 to 20°C after dissolving the diamine described later in the polymerization solvent described later, Stirring at 10 to 100°C, more preferably 10 to 30°C, obtains a polyamic acid solution (hereinafter, sometimes referred to as a polyamic acid solution).

The diamines that can be used in the present invention can be general aromatic diamines, aliphatic diamines, alicyclic diamines, etc. used in the production of polyimide. Examples of such diamines are: 1,4-diaminobenzene, 1,3-diaminobenzene, 2,4-diaminotoluene, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether (also known as 4,4'-oxydiphenylamine), 3,3'-diaminodiphenylbenzene, 3,4'-diaminodiphenyl Ether, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-bis(tris Fluoromethyl)-4,4'-diaminobiphenyl (also known as 2,2'-bis(trifluoromethyl)benzidine), 3,7-diamino-dimethyldibenzothiophene -5,5-dioxide, 4,4'-diamine Diphenyl ketone, 3,3'-diaminodiphenyl ketone, 4,4'-bis(4-aminophenyl) sulfide, 4,4'-diaminodiphenyl sulfone, 4, 4'-diaminobenzylaniline, 1,3-bis(4-aminophenoxy)propane, 1,4-bis(4-aminophenoxy)butane, 1,5-bis( 4-aminophenoxy)pentane, 1,3-bis(4-aminophenoxy)-2,2-dimethylpropane, 1,2-bis[2-(4-aminophenoxy Yl)ethoxy]ethane, 9,9-bis(4-aminophenyl) stilbene, 5(6)-amino-1-(4-aminomethyl)-1,3,3-tri Methyldihydroindene, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene Group) benzene, 4,4'-bis(4-aminophenoxy)biphenyl, 4,4'-bis(3-aminophenoxy)biphenyl, 2,2-bis[4-(4 -Aminophenoxy)phenyl]propane, bis[4-(4-aminophenoxy)phenyl]suan, bis[4-(3-aminophenoxy)phenyl]suan, 2, 2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 3,3'-dicarboxy-4,4'-diaminodiphenylmethane, 4,6-dicarboxy- 1,3-phenylenediamine, 3,3'-dihydroxy-4,4'-diaminobiphenyl, 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane, 3 ,3',4,4'-tetraaminobiphenyl, 1,6-diaminohexane, 1,3-bis(3-aminopropyl)tetramethyldisilaxane, 1-amino -3-aminomethyl-3,5,5-trimethylcyclohexane, 4,4'-methylenebis(4-cyclohexylamine), trans-1,4-cyclohexanediamine , Bicyclo[2.2.1]heptane bis(methylamine), tricyclo[3.3.1.13,7]decane-1,3-diamine (also known as adamantane-1,3-diamine), 4-aminobenzoic acid-4-aminophenyl ester, 2-(4-aminophenyl)aminobenzoxazole, 9,9-bis[4-(4-aminophenoxy)phenyl ] Fu, 2,2'-bis(3-sulfopropyloxy)-4,4'-diaminobiphenyl, 4,4'-bis(4-aminophenoxy)biphenyl-3 , 3'-disulfonic acid, 3,3'-diaminodiphenyl sulfone, etc. In addition, two or more of these diamines may be used in combination.

Among the above diamines, 3,3'-diaminodiphenyl sulfone, bicyclo[2.2.1]heptane bis(methylamine), trans-1,4-cyclohexanediamine, etc. are used fat In the case of cyclic diamines, the transparency of the polyimide obtained is more improved, and when using 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2, 2'-bis(trifluoromethyl)benzidine and other fluorine-containing diamines can significantly improve the solvent solubility of the obtained polyimide, and at the same time can also make the resulting polyimide low dielectric . When these diamines are used together with the tetracarboxylic dianhydride represented by the above formula (1) and other acid anhydrides, it is usually 0.9 to 1.1 moles relative to 1 mole of all acid dianhydrides including other acid dianhydrides. From the viewpoint of improving the degree of polymerization, it is better to use 0.95 to 1.05 moles.

In addition, general acid dianhydride may be used as a copolymerization component if necessary. Examples of acid dianhydrides that can be used in combination include pyromellitic anhydride, oxydiphthalic dianhydride, diphenyl-3,4,3',4'-tetracarboxylic dianhydride, and diphenyl ketone -3,4,3',4'-tetracarboxylic dianhydride, diphenyl sulfone-3,4,3',4'-tetracarboxylic dianhydride, 4,4'-(2,2-hexafluoro (Isopropylidene) diphthalic dianhydride, m-triphenyl-3,4,3',4'-tetracarboxylic dianhydride, p-triphenyl-3,4,3',4'- Tetracarboxylic dianhydride, cyclobutane-1,2,3,4-tetracarboxylic dianhydride, 1-carboxymethyl-2,3,5-cyclopentanetricarboxylic acid-2,6:3,5 -Dianhydride, cyclohexane-1,2,4,5-tetracarboxylic dianhydride, butane-1,2,3,4-tetracarboxylic dianhydride, 4-phenylethynyl phthalic anhydride, Naphthalene-1,4,5,8-tetracarboxylic dianhydride, 1,4-bis(1,3-bi- pendant-1,3-dihydroisobenzofuran-5-carboxylic acid) 1,4 -Phenylidene, etc., these acid dianhydrides may be used in combination of two or more. When other acid dianhydrides are used in combination, the use amount of other acid dianhydrides in all acid dianhydrides is preferably 10% by weight or more, more preferably 30% by weight or more, and on the other hand, 90% by weight or less, It is better to be below 70% by weight. When other acid dianhydrides of 10% by weight or more are used, as will be described later, by using other acid dianhydrides together, the effect of improving physical properties can be sufficiently obtained. On the other hand, in other acid dianhydrides When the use amount is 90% by weight or less, the characteristics of the structure derived from the tetracarboxylic dianhydride represented by the above formula (1) can be fully exhibited.

An example of the effect of using together with other acid dianhydride, by using 4,4'-(2,2-hexafluoroisopropylidene) phthalic dianhydride and other fluoric acid dianhydride together, the resulting polymer Acetylene reduces the dielectric constant. In addition, when acid dianhydrides such as pyromellitic anhydride having a rigid skeleton are used in combination, the heat resistance of the obtained polyimide can be improved.

In the manufacture of polyamic acid, the solvent that can be used is any tetracarboxylic dianhydride and diamine represented by the above formula (1) that can dissolve the raw material monomer, and the raw material and the resulting polyamide The acid may be inactive, and is not particularly limited. Examples of such solvents can be used: N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone and other amide solvents, butyl acetate, Chain ester solvents such as ethyl acetate and isobutyl acetate, cyclic ester solvents such as γ-butyrolactone, γ-caprolactone and ε-caprolactone, carbonates such as ethylene carbonate and propylene carbonate Solvents, triethylene glycol, ethylcellulose, butylcellulose, propylene glycol methyl acetate, 2-methylcellulose acetate, ethylcellulose acetate, butylcellulose Glycol solvents such as threoacetate, dimethoxyethane, diethoxyethane, diethylene glycol, etc., phenol, o-cresol, m-cresol, p-cresol, 3-chlorophenol, 4- Phenolic solvents such as chlorophenol, ether solvents such as tetrahydrofuran, dibutyl ether, and diethyl ether, methyl isobutyl ketone, diisobutyl ketone, cyclohexanone, methyl ethyl ketone, acetone, styrene Ketone solvents such as ketones, alcohol solvents such as butanol and ethanol, aromatic solvents such as xylene, toluene, and chlorobenzene, benzene solvents such as cyproterone, dimethyl sulfoxide and the like. Preferred examples are: N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-pyrrole Acetylamine solvents such as pyridone are preferred. One type of these solvents may be used, or two or more types may be mixed and used as necessary.

The amount of the solvent used is usually 5 to 40% by weight, preferably 8 to 25% by weight, in the total concentration (monomer concentration) of the monomer components (tetracarboxylic dianhydride + diamines) in the reaction system. Polymerization is carried out in the aforementioned monomer concentration range to obtain a uniform and highly polymerized polyamide solution. In addition, when the polymerization is performed at a concentration lower than the above-mentioned monomer concentration range, the degree of polymerization of the polyamic acid cannot be sufficiently high, so the polyimide film finally obtained may become fragile. When the polymerization is carried out at a high concentration in the monomer concentration range, the monomer may not be fully dissolved and the reaction solution may be uneven and colloidal. The solution of the polyamic acid having the repeating unit represented by the above formula (2) obtained by the above method is usually directly used as a solution in the polyimination step described later.

<Polyimide having the repeating unit represented by the above formula (3) and its production method>

The polyimide having the repeating unit represented by the above formula (3) of the present invention can provide a dehydration cyclization reaction (imidization) with the polyamic acid having the repeating unit represented by the above formula (2) obtained by the above method Reaction). Examples of the method of the imidization reaction include thermal imidization and chemical imidization.

First, the thermal imidization method will be described in detail. The thermal imidization method is to first cast a polymer solution of polyamic acid on a glass plate, and then heat it in a vacuum, inert gas such as nitrogen, or in air to obtain a polyamic acid film. Specifically, for example, by drying in an autoclave, usually at 50 to 190°C, and more preferably at 100 to 180°C, that is A film of polyamide can be obtained.

Next, the resulting film of polyamide is heated on a glass plate at usually 200 to 400°C, more preferably 250 to 350°C. In this way, the polyimide film can be obtained by starting the imidization reaction. The heating temperature is preferably 200°C or higher from the viewpoint that the imidization reaction can sufficiently proceed, and preferably 400°C or lower from the viewpoint of the thermal stability of the polyimide film formed.

The imidization reaction is preferably carried out in vacuum or in an inert gas. When the temperature of the imidization reaction is not too high, it can be carried out in air.

Next, the chemical imidization method will be described in detail. The chemical imidization method is to first add the same solvent during polymerization to the polyamic acid solution of the invention having the repeating unit represented by the above formula (2) obtained by the above method to become a moderate solution viscosity that is easy to stir, and then Under stirring, add organic acid anhydride and dehydration cyclizing agent (these two can also be called chemical imidizing agent), and at a temperature of 0 to 100 ℃, more preferably at 10 to 50 ℃ stirring 1 to 72 The chemical imidization can be completed within hours.

Examples of organic acid anhydrides that can be used in chemical imidization include acetic anhydride and propionic anhydride. Among these organic acid anhydrides, acetic anhydride is preferred because it is easy to handle and easy to separate. Also dehydration cyclization agent, can be used: pyridine, triethylamine, quinoline and so on. Among these dehydration cyclization agents, pyridine is preferred because of its easy operation and simple separation. The amount of organic acid anhydride in the chemical imidization agent is preferably in the range of 1 to 10 times the molar amount of the theoretical dehydration amount of the polyamic acid, and more preferably 2 to 10 times the molar amount. The amount of dehydration cyclizing agent is preferably in the range of 0.1 to 5 times the molar amount relative to the amount of organic acid anhydride. The range of 1 to 5 times mole is better.

Since the reaction solution obtained by the above chemical imidization method is mixed with unreacted chemical imidization agents, organic acids and other by-products (hereinafter, referred to as impurities), these can also be removed to separate/refine polyimide amine. For purification, generally known methods can be used. For example, a reaction solution that is imidized can be used, dropped in a poor solvent to precipitate polyimide, and then repeatedly washed and dried until polyimide powder is recovered to remove impurities, to obtain polyimide powder Methods. It can be used as a poor solvent, as long as it can precipitate polyimide, efficiently remove impurities, and is easy to dry. For example, water and alcohols such as methanol, ethanol, and isopropanol are preferred. Etc. mixed use.

When the concentration of the polyimide solution precipitated by dropping into a poor solvent is too high, the precipitated polyimide will form pellets, and impurities may remain in the pellets, and the resulting polyimide It takes a long time when the imine powder is redissolved in the solvent. Therefore, the concentration of the polyimide solution when dropped into a poor solvent is preferably 20% by weight or less, and more preferably 10% by weight or less. In addition, the amount of the poor solvent used is preferably 1 part by weight or more relative to the polyimide solution, and more preferably 1.5 to 10 parts by weight.

The temperature at which the obtained polyimide powder is recovered and the remaining solvent is removed by vacuum drying, hot air drying, etc. is not limited as long as it does not deteriorate the polyimide, and may be, for example, 30 to 150°C.

When the polyimide powder having the repeating unit represented by the above formula (3) thus obtained is a polyimide film, it is necessary to temporarily make the polyimide powder having the repeating unit represented by the above formula (3) Soluble Polyimide solution. The usable solvent may be any solvent that can properly dissolve the polyimide powder according to the application and processing conditions. Specific examples include N,N-dimethylformamide, N,N-dimethyl Acetylamine solvents such as ethyl acetamide, N-methyl-2-pyrrolidone, γ-butyrolactone, γ-valerolactone, δ-valerolactone, γ-caprolactone, ε-caprolactone, α-methyl-γ-butyrolactone, butyl acetate, ethyl acetate, isobutyl acetate and other ester solvents, ethylene carbonate, propylene carbonate and other carbonate solvents, diethylene glycol dimethyl ether, Glycol solvents such as triethylene glycol and triethylene glycol dimethyl ether, phenol solvents such as phenol, m-cresol, p-cresol, o-cresol, 3-chlorophenol and 4-chlorophenol, cyclopentanone , Cyclohexanone, acetone, methyl ethyl ketone, diisobutyl ketone, methyl isobutyl ketone and other ketone solvents, tetrahydrofuran, 1,4-dioxane, dimethoxyethane, diethoxy Ether, dibutyl ether and other ether solvents, in addition to other can also be used: acetophenone, 1,3-dimethyl-2-imidazolidinone, cyclobutane, dimethyl sulfoxide, propylene glycol methyl Acetate, ethylcellulose, butylcellulose, 2-methylcellulose acetate, ethylcellulose acetate, butylcellulose acetate, butanol, ethanol, Xylene, toluene, chlorobenzene, turpentine, mineral spirits, widely used solvents called petroleum brain system, etc. One type of these solvents may be used alone or two or more types may be used in combination. The method of dissolving the polyimide powder can be dissolved in the air or in an inert gas at a temperature ranging from room temperature to the boiling point of the solvent or below to become a polyimide solution.

Then, the polyimide solution obtained in this way is cast on, for example, a glass plate, and heated in a vacuum, inert gas such as nitrogen, or in air to remove the solvent to obtain a polyimide film. For example, in an oven, usually at 200 to 400 ℃, 250 to It is better to dry at 350°C to obtain a polyimide film. The polyimide film is preferably made in vacuum or in an inert gas. If the temperature is not too high, it can also be done in air.

The molecular weight of the polyimide having the repeating unit represented by the above formula (3) obtained by the above method is preferably a weight average molecular weight of 10,000 to 600,000 obtained by the measurement method described later, and preferably 20,000 to 500,000 Better, from 40,000 to 400,000 is even better. When the molecular weight of the polyimide is 10,000 or more, it can be formed, and it is easy to maintain good mechanical properties. In addition, when the molecular weight of the polyimide is 400,000 or less, the molecular weight can be easily controlled during synthesis, and a solution with an appropriate viscosity can be easily obtained. Therefore, there are many cases where the operation is easy. In addition, the molecular weight of the polyimide can be a standard for the viscosity of the polyimide solution.

The polyimide having the repeating unit represented by the above formula (3) of the present invention obtained by the above method is excellent in solvent solubility, the refractive index also shows a high refractive index of 1.65 or more, and the glass transition temperature is also 260°C or more The heat resistance is excellent. Furthermore, when combined with the diamine used, it can be a polyimide with both low dielectric constant and high transparency.

Examples

The embodiments of the present invention are presented below, but the present invention is not limited thereto. The physical property values shown in the examples/comparative examples are the results of measurements with the following measuring devices and conditions.

〔1〕NMR measurement

¹ H-NMR and ¹³ C-NMR use tetramethylsilane as the internal standard, use hexahydrogen DMSO solvent, and record with JEOL-ESC400 spectrophotometer.

〔2〕LC-MS measurement

Separate and analyze the quality under the following measurement conditions to identify the target.

×100mm)，‧管柱溫度：40℃，‧檢測波長：UV 220至500nm，‧流動相：A液=0.1%甲酸溶液，B液=乙腈，‧流動相流量：0.3mL/分鐘，‧流動相梯度：B液濃度：80%(0分鐘)→80%(10分鐘後)→100%(15分鐘後)，‧檢測方法：Q-Tof，‧離子化法：APCI(-)法，‧離子源：溫度120℃，‧採樣錐：電壓50V，氣體流量50L/小時，‧去溶劑化氣體：溫度500℃，氣體流量1000L/小時。 ‧Apparatus: “Xevo G2 Q-Tof” manufactured by Waters, ‧Column: ACQUITY UPLC BEHC18, (1.7μm, 2.1mm

×100mm), ‧Column temperature: 40℃, ‧Detection wavelength: UV 220 to 500nm, ‧Mobile phase: Liquid A = 0.1% formic acid solution, Liquid B = acetonitrile, ‧Mobile phase flow rate: 0.3mL/min, ‧Flow Phase gradient: B liquid concentration: 80% (0 minutes) → 80% (after 10 minutes) → 100% (after 15 minutes), ‧ detection method: Q-Tof, ‧ ionization method: APCI (-) method, ‧ Ion source: temperature 120℃, ‧sampling cone: voltage 50V, gas flow 50L/hour, ‧desolvated gas: temperature 500℃, gas flow 1000L/hour.

〔3〕HPLC purity

The area percentage value at the time of high-speed liquid chromatography (HPLC) measurement under the following measurement conditions was taken as the purity of each compound.

×250mm)，‧管柱溫度：40℃，‧檢測波長：UV 254nm，‧流動相：A液=己烷，B液=四氫呋喃， ‧流動相流量：1.0mL/分鐘，‧流動相梯度：A液濃度：85%(0分鐘)→60%(35分鐘後)→0%(40分鐘後)。 ‧Installation: L-2130 manufactured by Hitachi, Ltd. ‧Column: ZORBAX CN (5μm, 4.5mm

×250mm), ‧Column temperature: 40℃, ‧Detection wavelength: UV 254nm, ‧Mobile phase: Liquid A = hexane, Liquid B = tetrahydrofuran, ‧Mobile phase flow rate: 1.0mL/min, ‧Mobile phase gradient: A Liquid concentration: 85% (0 minutes) → 60% (after 35 minutes) → 0% (after 40 minutes).

〔4〕Weight average molecular weight of polyamide

The weight average molecular weight was measured under the following measurement conditions. (Converted polystyrene) ‧Equipment: HLC-8320GPC manufactured by Tosoh Corporation, ‧Column: TSK-GEL Super AWM-H (6.0mm ID×15cm), ‧Mobile phase: N,N-dimethyl formaldehyde Acetamide, flow rate: 0.6mL/min, ‧column temperature: 40℃.

〔5〕Determination of melting point

Using a differential scanning calorimeter (SII Nanotechnology Co., Ltd.), "EXSTAR DSC 7020C", the maximum temperature of the melting endotherm detected during the measurement at a heating rate of 10°C/min is the melting point.

〔6〕Determination of glass transition temperature (Tg)

A differential scanning calorimeter (SII Nanotech Co., Ltd. "EXSTAR DSC 7020C") was used. The temperature was measured at a heating rate of 30°C/min. The intersection point of the tangent to the inflection point was taken as the glass transition temperature.

〔7〕Measurement of the cut-off wavelength

Using a spectrophotometer ("UV-2450" manufactured by Shimadzu Corporation), the transmittance of the polyimide film from 200 to 800 nm was measured. The wavelength with a transmittance of 0.5% or less is the cutoff wavelength. The shorter the cutoff wavelength, the better the transparency of the polyimide film.

〔8〕Measurement of light transmittance (T ₄₀₀ )

Using a spectrophotometer ("UV-2450" manufactured by Shimadzu Corporation), the 400 nm transmittance of the polyimide film was measured. The higher the transmittance, the better the transparency of the polyimide film.

〔9〕Measurement of refractive index (n _in ) and dielectric constant (ε)

Abbe refractometer ("Multi-wavelength Abbe Refractometer DR-M2" manufactured by Atago Co., Ltd.) was used to measure the parallel (n _in ) and vertical (n _out ) refraction of the polyimide film. Ratio (wavelength: 589 nm), the average refractive index (n _av ) of polyimide is determined by the following formula.

n _av = (2n _in +n _out )/3

Based on the average refractive index (n _av ), the dielectric constant (ε) of the polyimide film at 1 MHz is calculated by the following formula.

ε=1.1×n _av ²

〔10〕Determination of tensile elongation

Using a tensile testing machine ("AUTOGRAPH AGS-X" manufactured by Shimadzu Corporation), a tensile test was performed on a test piece of a polyimide film (dumbbell-shaped test piece parallel part 5 mm × 20 mm) (tensile speed 10 mm/ Minutes) to determine the tensile elongation (%) of the film. The higher the tensile elongation, the higher the toughness of the film.

〔11〕Solvent solubility

Add 20 mg of the obtained polyimide film or powder to 1 mL of N,N-dimethylacetamide (DMAc), N-methyl-2-pyrrolidone (NMP), tetrahydrofuran (THF), cyclopentanone (CPN), γ-butyrolactone (GBL), the solubility was tested. The solvent solubility was evaluated according to the following criteria.

○: Dissolve at room temperature.

△: It dissolves when heated and does not precipitate even after cooling to room temperature.

×: Does not dissolve.

1. Production example of acid dianhydride represented by the above formula (1)

<Example 1>

In a 1 L 4-neck flask equipped with a thermometer, a dropping funnel, and a stirring bar, add 11.0 g (52.2 mmol) of trimellitic anhydride chloride, 20.0 g of acetonitrile, 10.0 g of toluene, and 9,9-bis(4-(4 -Hydroxyphenyloxy)phenyl) stilbene (BPOPF) 10.0 g (18.7 mmol), after stirring, cooled to 2°C again. After cooling, 4.1 g (51.8 mmol) of pyridine was added dropwise at 2°C to 7°C. After dropping, the temperature was raised to 25°C again. After the temperature was raised, crystals began to precipitate at the time of stirring at the same temperature for 1 hour. Therefore, 10.0 g of acetonitrile and 5.0 g of toluene were added, and stirring was performed for another 1 hour.

After the stirring is completed, the crystals are filtered at 25°C, and the crystals are washed with acetonitrile to obtain yellow crystals. The yellow crystals were vacuum dried at 80° C. to obtain 11.6 g of the tetracarboxylic dianhydride of the above formula (1) (production rate 70.2 g, purity 99.4%).

From the ¹ H-NMR spectrum shown in Fig. ¹ , the ¹³ C-NMR spectrum shown in Fig. 2 and the mass analysis chart shown in Fig. 3, it was confirmed that the resulting product was represented by the above formula (1) The tetracarboxylic dianhydride. Hereinafter, ¹ H-NMR and ¹³ C-NMR of the obtained tetracarboxylic dianhydride represented by the above formula (1) will be described in detail.

Fig. 1 shows a ¹ H-NMR (DMSO-d ₆ ) diagram of the obtained tetracarboxylic dianhydride represented by the above formula (1). Among them, the peak of 8.26 to 8.64 ppm belongs to the hydrogen on the benzene ring of trimellitic acid, the peak of 7.35 to 7.96 ppm belongs to the hydrogen of the benzene ring of the stilbene skeleton, and the peak of 6.95 to 7.43 ppm belongs to 4-(4- Hydroxyphenyloxy) phenyl hydrogen on the benzene ring. In addition, the peak observed at 2.5 ppm is DMSO of the solvent, and the peak observed at 3.3 ppm is derived from the water contained in DMSO.

Figure 2 shows a ¹³ C-NMR (DMSO-d ₆ ) diagram. Among them, 164.0 to 168.9 ppm and 139.95 to 156.02 ppm are carbons derived from the trimellitic anhydride skeleton, and 118.8 to 138.83 ppm are derived from 9,9-bis(4-(4-hydroxyphenyloxy)phenyl) The carbon peak of stilbene benzene ring, the peak of 64.4ppm belongs to the ninth carbon of stilbene. In addition, the peaks observed at 39.2 to 40.5 ppm are those of DMSO derived from solvents.

The mass spectrum value and melting point of the obtained tetracarboxylic dianhydride represented by the above formula (1) are as follows.

Mass spectrum value (M-‧): 882.17,

Melting point (DSC): 193°C.

2. Examples of the production of the polyamic acid having the repeating unit represented by the above formula (2) and the polyimide having the repeating unit represented by the above formula (3)

<Example 2>

(In the polyamic acid represented by the above formula (2), the tetracarboxylic dianhydride represented by the above formula (1) and 9,9-bis(4-aminophenyl) stilbene (hereinafter, sometimes referred to as (FDA) Production example of polyamic acid (called polyamic acid having a repeating unit represented by the following formula (2-A)) prepared by the reaction)

The FDA of 5.0 g (5.66 mmol) and 2.0 g (5.66 mmol) of tetracarboxylic dianhydride represented by the above formula (1) obtained in Example 1 was dissolved in N,N-dimethylacetamide at room temperature In 80.2g of amine, after the temperature was raised to 100°C, the solution was determined to be homogeneous, and after cooling, the reaction was carried out at room temperature for 24 hours to synthesize a polyamic acid having a repeating unit represented by the above formula (2-A) . The weight average molecular weight (Mw) of polyamide is 335,368.

<Example 3>

(In the polyimide represented by the above formula (3), the chemical imidization of the polyamic acid having the repeating unit represented by the above formula (2-A) has the following formula (3-A) (Manufacture of polyimide shown as a repeating unit)

To the N,N-dimethylacetamide solution of the polyamic acid having the repeating unit represented by the above formula (2-A) obtained in Example 2, 87.2 g of acetic anhydride and 2.2 g of pyridine were added, After stirring at room temperature for 24 hours, a N,N-dimethylacetamide solution of polyimide having a repeating unit represented by the above formula (3-A) was obtained.

The obtained N,N-dimethylacetamide solution of the polyimide having the repeating unit represented by the above formula (3-A) was dropped into 250 g of methanol to precipitate the above formula (3-A) Polyimide with repeating units shown. Then, the precipitated polyimide was filtered, washed with methanol, and dried to obtain 7.2 g of light yellow polyimide powder.

Then, 25.0 g of N,N-dimethylacetamide was added to 5.0 g of the obtained polyimide powder and stirred until uniform to obtain a polyimide having a repeating unit represented by the above formula (3-A) N,N-dimethylacetamide solution of amine. After coating this solution on a glass plate, it was heated at 150°C for 1 hour and at 250°C for 1 hour to obtain a thin film of polyimide having a repeating unit represented by the above formula (3-A). The film thickness is about 19 μm.

Table 1 shows the glass transition temperature (Tg), cutoff wavelength, transmittance at 400 nm (T ₄₀₀ ), refractive index (n _in ), dielectric constant (ε), stretching of the obtained polyimide film Measurement results of elongation. In addition, Table 2 shows the solubility in various solvents.

<Example 4>

(That is, in the polyamic acid represented by the above formula (2), the tetracarboxylic dianhydride represented by the above formula (1) and 2,2'-bis(trifluoromethyl)-4,4'-di Polyamino acids prepared by the reaction of aminobiphenyl (also known as 2,2'-bis(trifluoromethyl)benzidine) (hereinafter sometimes referred to as TFMB) (having the following formula (2-B ) Manufacture of the polyamide of the repeating unit shown))

The TFMB of 5.0 g (5.66 mmol) and 1.8 g (5.66 mmol) of tetracarboxylic dianhydride represented by the above formula (1) obtained in Example 1 was dissolved in N,N-dimethylacetamide at room temperature After 16.8 g of amine, the mixture was stirred at room temperature. Since the viscosity increases as the reaction progresses, by appropriately adding (total addition amount: 52.0 g) N,N-dimethylacetamide while stirring at room temperature for 25 hours, a compound having the above formula (2-B ) The N,N-dimethylacetamide solution of the polyamide of the repeating unit shown. The weight average molecular weight (Mw) of polyamide is 537,315.

<Example 5>

(In the polyimide represented by the above formula (3), the chemical imidization of the polyamic acid having the repeating unit represented by the above formula (2-B) has the following formula (3-B) (Manufacture of polyimide shown as a repeating unit)

Via 92.3 g of N,N-dimethylacetamide solution of the polyamidoamine having the repeating unit represented by the above formula (2-B) obtained in Example 4, acetic anhydride 5.8 g and pyridine 2.2 g were added After stirring at room temperature for 24 hours, a N,N-dimethylacetamide solution of polyimide having a repeating unit represented by the above formula (3-B) was obtained.

The obtained N,N-dimethylacetamide solution of the polyimide having the repeating unit represented by the above formula (3-B) was dropped into 250 g of methanol to have the above formula (3-B) The polyimide of the repeating unit is precipitated. The precipitated polyimide was filtered, washed with methanol, and dried to obtain 6.8 g of white polyimide powder.

Furthermore, 45.0 g of N,N-dimethylacetamide was added to 5.0 g of the obtained polyimide powder and stirred until uniform, to obtain a polyimide having a repeating unit represented by the above formula (3-B) N,N-dimethylacetamide solution. After the obtained solution was coated on a glass plate, it was heated at 150°C for 1 hour and at 250°C for 1 hour to obtain a thin film of a polyimide having a repeating unit represented by the above formula (3-B). The thickness of the thin film is about 14 μm.

Table 1 shows the glass transition temperature (Tg), cutoff wavelength, transmittance at 400 nm (T ₄₀₀ ), refractive index (n _in ), dielectric constant (ε), and tensile strength of the prepared polyimide film. The measurement result of elongation. In addition, Table 2 shows the solubility in various solvents.

3. Examples of the production of polyimide derived from acid dianhydride having other stilbene skeleton, and the physical properties of polyimide

<Reference Example 1>

(Production example of polyimide obtained from acid dianhydride and TFMB represented by the following formula (6) and having a repeating unit represented by the following formula (7))

The following formula (6):

The TFMB of 5.0g (6.88mmol) and 2.2g (6.88mmol) of the tetracarboxylic dianhydride shown are dissolved in 17.8g of N,N-dimethylacetamide at room temperature and reacted at room temperature for 24 hours , Synthesis of N,N-dimethylacetamide solution of polyamide. The weight average molecular weight (Mw) of polyamide is 66,029.

By adding 25.0g of N,N-dimethylacetamide solution of the obtained polyamic acid, 11.0g of N,N-dimethylacetamide, 7.0g of acetic anhydride and 2.7g of pyridine were added at room temperature The mixture was stirred for 22 hours to obtain a N,N-dimethylacetamide solution of polyimide having a repeating unit represented by the above formula (7).

The resulting N,N-dimethylacetamide solution of the polyimide having the repeating unit represented by the above formula (7) was dropped into 250 g of methanol to make the repeating unit represented by the above formula (7) Polyimide precipitates. The precipitated polyimide was filtered, washed with methanol, and dried to obtain 6.6 g of white polyimide powder.

Then, 20.0 g of N,N-dimethylacetamide was added to 5.0 g of the obtained polyimide powder and stirred until uniform to obtain N of polyimide having the repeating unit represented by the above formula (7), N-dimethylacetamide solution. After the obtained solution was coated on a glass plate, it was heated at 150°C for 1 hour and at 250°C for 1 hour to obtain a thin film of polyimide having a repeating unit represented by the above formula (7). The film thickness of the thin film is about 25 μm.

Table 1 shows the glass transition temperature (Tg), cutoff wavelength, transmittance at 400 nm (T ₄₀₀ ), refractive index (n _in ), dielectric constant (ε), and tensile strength of the prepared polyimide film. The measurement result of elongation.

Since the figure in this case is experimental data, it is not a representative figure in this case. Therefore, there is no designated representative figure in this case.

Claims (4)

A tetracarboxylic dianhydride represented by the following formula (1),

A polyamide having a repeating unit represented by the following formula (2),

In the formula, Z represents a diamine residue. A polyimide having a repeating unit represented by the following formula (3),

In the formula, Z represents a diamine residue. A method for producing tetracarboxylic dianhydride. The tetracarboxylic dianhydride is as described in item 1 of the patent application scope. The production method is to use a trimellitic anhydride halide and a bismuth represented by the following formula (4) Phenol reaction,

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