JP2008163090A - Tetracarboxylic acid dianhydride, method for producing the same and polymer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a high-purity tetracarboxylic acid dianhydride and a method for producing a polymer from the high-purity tetracarboxylic acid dianhydride. <P>SOLUTION: The method for producing an acid dianhydride represented by the general formula (1) (wherein, A is a bifunctional group; X<SP>1</SP>, X<SP>2</SP>, X<SP>3</SP>, X<SP>4</SP>, X<SP>5</SP>and X<SP>6</SP>are each independently a hydrogen atom, a halogen atom, a nitrile group, a nitro group, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an amino group or an amide group; the number of carbon atoms of a carbon-containing group is ≤10; and n is an integer of 0, 1 or 2) comprises carrying out recrystallization in the presence of an organic solvent having a solubility parameter δ (unit: MPa<SP>1/2</SP>) of ≥21.3 under measurement conditions at 1 atmospheric pressure at 25°C. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for producing high-purity acid dianhydride, and in particular, the reaction by-product is highly removed by recrystallization of tetracarboxylic dianhydride obtained by the reaction to highly purify tetracarboxylic dianhydride. It relates to a method for obtaining things. The present invention also relates to a tetracarboxylic dianhydride produced by this method and a polymer obtained using the tetracarboxylic dianhydride.

  Polyimide has not only excellent heat resistance but also chemical resistance, radiation resistance, electrical insulation, excellent mechanical properties, etc., so it can be used for flexible printed circuit boards, tape automation bonding substrates, and semiconductors. Currently, it is widely used in various electronic devices such as protective films for elements and interlayer insulating films for integrated circuits. Polyimide is also a very useful material in terms of simplicity of production method, high film purity, and ease of improving physical properties, and functional polyimide material designs suitable for various applications have been made in recent years.

  Since many polyimides are insoluble in organic solvents and do not melt above the glass transition temperature, it is usually not easy to mold the polyimide itself. For this reason, polyimide is generally obtained by first reacting an aromatic tetracarboxylic dianhydride such as pyromellitic anhydride with an aromatic diamine such as diaminodiphenyl ether in an aprotic polar organic solvent such as dimethylacetamide to obtain a high molecular weight. A polyimide precursor having a polymerization degree is polymerized, this solution is formed into a film or the like, heated at a temperature of about 250 ° C. to 350 ° C., and dehydrated and closed (imidized) to form a film.

  Thermal stress generated in the process of cooling the polyimide / metal substrate laminate from the imidization temperature to room temperature often causes serious problems such as curling, film peeling and cracking. Recently, with the increase in the density of electronic circuits, multilayer wiring boards have come to be used. However, even if film peeling or cracking does not occur, the residual stress in the multilayer board can increase device reliability. Reduce significantly. For this reason, reduction of thermal stress has also been studied, but these low thermal stress resins have a problem of low solubility in solvents and poor operability.

  On the other hand, when polyimide is soluble in an organic solvent, a thermal imidization step is not required. Therefore, after applying a polyimide organic solvent solution (varnish) on a metal substrate, the solvent is removed at a temperature much lower than the thermal imidization temperature. It is only necessary to evaporate and dry, and it is possible to reduce the thermal stress in the metal substrate / insulating film laminate. However, there are only a limited number of polyimides that are soluble in organic solvents and put into practical use, and development of polyimides having various physical properties that are soluble in solvents is awaited.

Furthermore, it is known that polyimide generally has a high water absorption rate. Water absorption in the insulating layer causes serious problems such as dimensional change of the insulating film and deterioration of electrical characteristics. It has been reported that the introduction of an ester bond into a polyimide skeleton is effective as a molecular design for realizing a low water absorption rate (Non-patent Document 1).
In recent years, increasing the calculation speed of microprocessors and shortening the rise time of clock signals have become important issues in the information processing and communication fields. To that end, polyimide films used as insulating films It is necessary to lower the dielectric constant. Also, for high-density wiring and a multilayer substrate for shortening the electrical wiring length, it is advantageous in that the insulating layer can be made thinner as the dielectric constant of the insulating film is lower.

Introduction of a fluorine substituent into the skeleton is effective for lowering the dielectric constant of polyimide (Non-patent Document 2). However, the use of fluorinated monomers is disadvantageous in terms of cost.
In addition, replacing aromatic units with alicyclic units to reduce π electrons is an effective means for reducing the dielectric constant (Non-patent Document 3).

  However, it is not easy in terms of molecular design to obtain a polyimide having low dielectric constant (target value of 3.0 or less), low water absorption and solvent solubility at the same time, and maintaining solder heat resistance. No practical material is known so far. Low dielectric constant polymer materials and inorganic materials other than polyimide are also being studied, but at present the required characteristics are not sufficiently satisfied in terms of dielectric constant, heat resistance and toughness.

  Furthermore, in recent years, the demand for a polyimide exhibiting high transparency in the visible light region is increasing due to the demand for development of optical material applications. In addition to this transparency, if a polyimide having heat resistance, solubility, and moderate toughness is obtained, it can be suitably used as a flexible substrate for liquid crystal displays and EL displays, and various optical property members used inside. However, at present, no material having such physical properties is known.

  In addition, for the purpose of performing through-hole formation and fine processing on polyimide as an insulating layer, a photosensitive polyimide system in which photosensitive performance is imparted to polyimide or its precursor itself has been actively studied. On the other hand, etching is performed on polyimide itself with a basic substance to form through holes. However, in the latter, since the etching rate of the polyimide film with alkali is usually slow, the etching solution is limited to a special basic substance such as ethanolamine, and even if ethanolamine is used, it cannot be applied to all polyimides. If a material having the above-mentioned required characteristics and easily etched by a general-purpose basic substance is developed, a material that is extremely useful in the industrial field can be provided. However, such a material is currently known. It is not done.

  Solving such conventional problems, it has a high glass transition temperature, high transparency, low water absorption and etching characteristics, and the field of electronic materials such as electrical insulating films and laminates, flexible printed wiring boards in various electronic devices, Display devices such as liquid crystal display substrates, organic electroluminescence (EL) display substrates, electronic paper substrates, optical materials such as lenses, diffraction gratings and optical waveguides, semiconductors such as buffer coat films and interlayer insulation films, In addition, as an ester group-containing alicyclic tetracarboxylic dianhydride capable of providing a useful alicyclic polyesterimide in a solar cell substrate, photosensitive material, etc., the present applicant has previously described a general formula (1) described later. The ester group containing alicyclic tetracarboxylic dianhydride represented by these was proposed (patent document 1).

  Since this tetracarboxylic dianhydride has characteristics such as having an alicyclic skeleton and containing an ester group, a polyimide resin synthesized from this acid dianhydride has high heat resistance while maintaining high heat resistance. It has excellent properties such as transparency, low dielectric property, low water absorption, low thermal expansion, solvent solubility and etching properties. For this reason, resins for electronic materials such as electrical insulation films and flexible printed wiring boards, substrates for liquid crystal displays, substrates for organic electroluminescence (EL) displays, substrates for electronic paper, substrates for solar cells, sealing for light emitting diodes It can be used for an optical material such as an agent and an optical waveguide.

  In general, in the production of polyimide resin, it is known that the purity of tetracarboxylic dianhydride and diamine as raw materials has a great influence on the degree of polymerization, and polyimide having a sufficient degree of polymerization when used in each of the above applications. It is necessary to use high-purity raw materials to obtain

However, the acid dianhydride represented by the general formula (1) cannot be applied to the recrystallization method, which is the simplest purification method, because of its low solubility in a commonly used solvent. Could not get. For this reason, the degree of polymerization was not sufficiently increased, and a high-performance polyimide resin could not be obtained. The main factor that the degree of polymerization does not increase is the influence of monoacid anhydride contained in acid dianhydride.
Japanese Patent Application No. 2006-308082 Proceedings of Macromolecules Conference, 53, 4115 (2004) Macromolecules, 24,5001 (1991) Macromolecules, 32, 4933 (1999)

  The present invention can have excellent properties such as high transparency, low dielectric property, low water absorption, low thermal expansion, solvent solubility, and etching properties while maintaining high heat resistance, and can be used as an electric insulating film and a flexible film. Optical materials such as resins for electronic materials such as printed wiring boards, substrates for liquid crystal displays, substrates for organic electroluminescence (EL) displays, substrates for electronic paper, substrates for solar cells, sealants for light emitting diodes, optical waveguides, etc. A method for producing tetracarboxylic dianhydride which is a useful raw material for producing a resin usable for use, a tetracarboxylic dianhydride produced by this production method, and this tetracarboxylic dianhydride A polymer obtained as a raw material is provided.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors recrystallized using a solubility parameter having a solubility parameter δ greater than or equal to a predetermined value, thereby producing a tetracarboxylic acid dicarboxylic acid represented by the following general formula (1). We have found that the anhydride can be highly purified.

  The present invention has been achieved based on the above findings, and the gist thereof is as follows.

（式（１）中、Ａは２価の基を示す。
Ｘ^１、Ｘ^２、Ｘ^３、Ｘ^４、Ｘ^５、およびＸ^６は各々独立に水素原子、ハロゲン原子、ニトリル基、ニトロ基、アルキル基、アルケニル基、アルキニル基、アルコキシ基、アミノ基、またはアミド基を表す。ただし、これらの基は更に置換基を有していても良く、炭素含有基にあっては、その炭素数は１０以下である。
ｎは０、１または２の整数を表す。）
δ＝（ΔＨ／Ｖ）^１／２ （２）
（式（２）において、ΔＨおよびＶは、それぞれ前記有機溶媒のモル蒸発熱（単位：Ｊ／ｍｏｌ）およびモル体積（単位：ｃｍ^３／ｍｏｌ）である。） [1] A method for producing a tetracarboxylic dianhydride represented by the following general formula (1), wherein the solubility parameter δ () represented by the following formula (2) under the measurement conditions of 1 atm and 25 ° C. A method for producing a high-purity acid dianhydride, characterized in that recrystallization is performed in the presence of an organic solvent having a unit of MPa ^1/2 ) of 21.3 or more.

(In the formula (1), A represents a divalent group.
X ¹ , X ² , X ³ , X ⁴ , X ⁵ , and X ⁶ are each independently a hydrogen atom, halogen atom, nitrile group, nitro group, alkyl group, alkenyl group, alkynyl group, alkoxy group, amino group, or Represents an amide group. However, these groups may further have a substituent, and in the case of a carbon-containing group, the carbon number is 10 or less.
n represents an integer of 0, 1 or 2. )
δ = (ΔH / V) ^1/2 (2)
(In the formula (2), ΔH and V are respectively the molar evaporation heat (unit: J / mol) and the molar volume (unit: cm ³ / mol) of the organic solvent.)

[2] A method for producing a high-purity acid dianhydride according to [1], wherein an acid anhydride is added to the organic solvent and recrystallization is performed.

[3] A method for producing a high-purity acid dianhydride according to [2], wherein the acid anhydride is a carboxylic acid anhydride having 10 or less carbon atoms.

[4] In any one of [1] to [3], the solvent used for recrystallization does not substantially react with the tetracarboxylic dianhydride represented by the general formula (1). Method for producing acid dianhydride.

[5] The method for producing a high-purity acid dianhydride according to any one of [1] to [4], wherein the solvent used for recrystallization has a boiling point of 100 ° C. or higher at normal pressure.

（式（１）中、Ａは２価の基を示す。
Ｘ^１、Ｘ^２、Ｘ^３、Ｘ^４、Ｘ^５、およびＸ^６は各々独立に水素原子、ハロゲン原子、ニトリル基、ニトロ基、アルキル基、アルケニル基、アルキニル基、アルコキシ基、アミノ基、またはアミド基を表す。ただし、これらの基は更に置換基を有していても良く、炭素含有基にあっては、その炭素数は１０以下である。
ｎは０、１または２の整数を表す。）

（式（３）中、Ａ、Ｘ^１、Ｘ^２、Ｘ^３、Ｘ^４、Ｘ^５、Ｘ^６、ｎは一般式（１）におけると同義である。） [6] A tetracarboxylic dianhydride represented by the following general formula (1), wherein the content of the monoacid anhydride represented by the following general formula (3) is relative to the tetracarboxylic dianhydride. Tetracarboxylic dianhydride, characterized in that it is 1 mol% or less.

(In the formula (1), A represents a divalent group.
X ¹ , X ² , X ³ , X ⁴ , X ⁵ , and X ⁶ are each independently a hydrogen atom, halogen atom, nitrile group, nitro group, alkyl group, alkenyl group, alkynyl group, alkoxy group, amino group, or Represents an amide group. However, these groups may further have a substituent, and in the case of a carbon-containing group, the carbon number is 10 or less.
n represents an integer of 0, 1 or 2. )

(In the formula (3), A, X ¹ , X ² , X ³ , X ⁴ , X ⁵ , X ⁶ , and n are as defined in the general formula (1).)

[7] A polymer produced using the tetracarboxylic dianhydride according to [6].

  According to the present invention, high-purity tetracarboxylic dianhydride can be produced by recrystallization using a specific organic solvent. Thus, using the tetracarboxylic dianhydride having a low content of impurities such as monoacid anhydride produced in this way, high heat resistance, high transparency, low dielectric property, low water absorption, low heat It becomes possible to produce a polymer having both expansibility, solvent solubility and etching characteristics.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail. However, the description of constituent elements described below is an example (representative example) of an embodiment of the present invention, and is not specified by these contents.

（式（１）中、Ａは２価の基を示す。
Ｘ^１、Ｘ^２、Ｘ^３、Ｘ^４、Ｘ^５、およびＸ^６は各々独立に水素原子、ハロゲン原子、ニトリル基、ニトロ基、アルキル基、アルケニル基、アルキニル基、アルコキシ基、アミノ基、またはアミド基を表す。ただし、これらの基は更に置換基を有していても良く、炭素含有基にあっては、その炭素数は１０以下である。
ｎは０、１または２の整数を表す。） [Tetracarboxylic dianhydride]
The tetracarboxylic dianhydride produced in the present invention (hereinafter sometimes referred to as “the compound of the present invention”) is represented by the following general formula (1).

(In the formula (1), A represents a divalent group.
X ¹ , X ² , X ³ , X ⁴ , X ⁵ , and X ⁶ are each independently a hydrogen atom, halogen atom, nitrile group, nitro group, alkyl group, alkenyl group, alkynyl group, alkoxy group, amino group, or Represents an amide group. However, these groups may further have a substituent, and in the case of a carbon-containing group, the carbon number is 10 or less.
n represents an integer of 0, 1 or 2. )

The structure of A in the general formula (1) is not particularly limited as long as it is bonded to a carboxyl group so as to form the structure at two locations.
Specifically, in general formula (1), A may be any divalent group. The compound of the present invention is characterized by a structure having two alicyclic structures and two ester groups connecting the two alicyclic structures, and by having this structure, high transparency and high toughness when an alicyclic polyesterimide resin is obtained. , Physical properties such as high solvent solubility can be obtained. That is, even if the structure of A is an arbitrary divalent group, these physical properties of the present compound tend not to be greatly affected. Therefore, the structure of A is not particularly limited as long as it is an arbitrary divalent group.

Among these divalent groups, a group having a cyclic structure is preferable. The structure having a cyclic structure means a structure containing an aromatic group in A or a structure containing an alicyclic structure. When A has a cyclic structure, the heat resistance and dimensional stability of the alicyclic polyesterimide resin are improved. Further, when the alicyclic structure is included, it is possible to obtain a feature that light absorption in the UV region can be reduced while maintaining heat resistance. Specific examples of the structure include phenylene group, naphthylene group, biphenylene group, diphenyl ether group, diphenylsulfone group, 4,4 ′-(9-fluorenylidene) diphenyl, which are all divalent groups as aromatic groups. Group, methylenediphenyl group, isopropylidenediphenyl group, 3,3 ′, 5,5′-tetramethyl- (1,1′-biphenyl) group and the like, and alicyclic structures include cyclohexylene group, cyclohexanediphenyl group, and the like. A methylene group, a decahydronaphthylene group, etc. are mentioned. Furthermore, a structure in which a plurality of these groups are bonded to each other or a linking group may be used. Specific examples of the linking group applicable here include a methylene group (—CH ₂ —), an ether group (—O—), an ester group (—C (O) O—), a keto group (—C ( O)-), a sulfonyl group (—SO ₂ —), a sulfinyl group (—SO—), a sulfenyl group (—S—), a 9,9-fluorenylidene group, and the like. In addition, regarding the group containing the above-mentioned divalent cyclic structure, the substitution position is not particularly limited. For example, a phenylene group is preferred when it is substituted at the 1,4-position, since the structure of -A- becomes a straight line, so that the heat resistance is improved and the linear expansion coefficient is expected to be small. On the other hand, substitution at the 1,3-position in the phenylene group is preferable because the -A- structure is bent, so that improvement in solubility in a solvent is expected. Therefore, as for the substitution position, it is preferable to select A having an appropriate structure according to the required physical properties.

  In a more preferred structure, A is a group containing an aromatic group. When the aromatic group is contained, the heat resistance and dimensional stability of the alicyclic polyesterimide resin are further improved, and the refractive index is improved. Specific examples of the aromatic group include those described above. Among them, phenylene group, biphenylene group, diphenyl ether group, diphenyl sulfone group, 4,4 ′-(9-fluorenylidene) diphenyl group, 3, The 3 ′, 5,5′-tetramethyl- (1,1′-biphenyl) group or the like is particularly preferable in that it has a more rigid structure. Furthermore, phenylene group, 4,4 ′-(9-fluorenylidene) diphenyl group, 3,3 ′, 5,5′-tetramethyl- (1,1′-biphenyl) group is a raw material, and the resulting resin This is preferable because of its good physical properties.

In the general formula (1), X ¹ , X ² , X ³ , X ⁴ , X ⁵ and X ⁶ are each independently a hydrogen atom, halogen atom, nitrile group, nitro group, alkyl group, alkenyl group, alkynyl. Represents a group, an alkoxy group, an amino group, or an amide group. As for carbon number of an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an amino group, and an amide group, 1-10 are preferable. More specifically, examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, and an n-butyl group. Examples of the alkoxy group include a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, and an n-butoxy group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Among these examples, it is easy to obtain raw materials that X ¹ , X ² , X ³ , X ⁴ , X ⁵ and X ^{6 in the} general formula (1) are each independently a hydrogen atom or a halogen atom. This is preferable. In this case, the number of halogen atoms and the substitution position are not particularly limited. More preferably, X ¹ , X ² , X ³ , X ⁴ , X ⁵ and X ^{6 in the} general formula (1) are all hydrogen atoms.

As a preferred structure as a combination of A and X ¹ , X ² , X ³ , X ⁴ , X ⁵ and X ⁶ , A is a group having a cyclic structure, and X ¹ , X ² , X ³ , X ⁴ , X ⁵ and X ⁶ are each independently composed of a halogen atom or a hydrogen atom. More preferably, A is a group having a cyclic structure, and X ¹ , X ² , X ³ , X ⁴ , X ⁵ and X ⁶ are all composed of hydrogen atoms.

In the general formula (1), n represents an integer of 0, 1 or 2, preferably n = 0 or n = 1, more preferably n = 1. In general formula (1), n in the ring substituted by X ^{1 to} X ³ and n in the ring substituted by X ^{3 to} X ⁶ are not necessarily the same, and may be different. good.

[Contained impurities]
The tetracarboxylic dianhydride represented by the general formula (1) is produced by a reaction between a corresponding acid anhydride and a diol. As a reaction byproduct derived from the production process, for example, the following general formula ( The monoacid anhydride represented by 3) and the monoester represented by the following general formula (4) are included.

（式（３）中、Ａ、Ｘ^１、Ｘ^２、Ｘ^３、Ｘ^４、Ｘ^５、Ｘ^６、ｎは一般式（１）におけると同義である。）

(In the formula (3), A, X ¹ , X ² , X ³ , X ⁴ , X ⁵ , X ⁶ , and n are as defined in the general formula (1).)

（式（４）中、Ａ、Ｘ^１、Ｘ^２、Ｘ^３、ｎは一般式（１）におけると同義である。）

(In the formula (4), A, X ¹ , X ² , X ³ and n have the same meaning as in the general formula (1).)

  Since these impurities are factors that inhibit the polymerization reaction, in the present invention, these impurities are removed and purified by recrystallization using a specific organic solvent.

[Organic solvent used for recrystallization]
In the present invention, the tetracarboxylic dianhydride represented by the general formula (1) containing the above-described impurities obtained by the reaction is represented by the following formula (2) under the measurement conditions of 1 atm and 25 ° C. Purification is performed by recrystallization in the presence of an organic solvent having a solubility parameter δ (unit: MPa ^1/2 ) of 21.3 or more.
δ = (ΔH / V) ^1/2 (2)
(In the formula (2), ΔH and V are respectively the molar evaporation heat (unit: J / mol) and the molar volume (unit: cm ³ / mol) of the organic solvent.)
The heat of molar evaporation of the organic solvent can be measured using calorimetry as described in "Experimental Chemistry Course 4th Edition Volume 4" (Maruzen).
In addition, data of solubility parameters of various solvents are described in “Polymer Handbook 4th Edition” (WILEY-INTERSCIENCE).

If the solubility parameter of the organic solvent used for recrystallization is less than 21.3 MPa ^1/2 , the solubility of the target tetracarboxylic dianhydride is low and it is very difficult to purify by recrystallization. Preferably the solubility parameter is ^{22 MPa 1/2} or more, further preferably ^{24 MPa 1/2} or more. The upper limit is not particularly limited in the solubility parameter, 40 MPa ^1/2 or less is preferable because it tends to solubility too high fall.

  Examples of the organic solvent satisfying such a solubility parameter include the following.

γ-butyrolactone (solubility parameter: 25.8 MPa ^1/2 )
Dimethyl sulfoxide (solubility parameter: 29.7 MPa ^1/2 )
N, N-dimethylformamide (solubility parameter: 24.8 MPa ^1/2 )
N-methylpyrrolidone (solubility parameter: 23.1 MPa ^1/2 )
N, N-dimethylacetamide (solubility parameter: 22.1 MPa ^1/2 )
Acetophenone (solubility parameter: 21.7 MPa ^1/2 )
Cyclopentanone (solubility parameter: 21.3 MPa ^1/2 )
These organic solvents may be used individually by 1 type, and may use 2 or more types together.

  These organic solvents preferably do not substantially react with the target tetracarboxylic dianhydride. Examples of the organic solvent that reacts with tetracarboxylic dianhydride include alcohols and amines.

The boiling point of these organic solvents at normal pressure is preferably 100 ° C. or higher, more preferably 120 ° C. or higher. If the boiling point is too low, the temperature cannot be raised too much at normal pressure when dissolving the crude tetracarboxylic dianhydride, so a problem arises that a large amount of solvent is required or the need to pressurize arises. Arise. The upper limit of the boiling point is not particularly limited, but if it is too high, it becomes difficult to remove the solvent adhering to the purified tetracarboxylic dianhydride after recrystallization by drying, so 300 ° C. is preferable, more preferably 250 ° C.

  The amount of the organic solvent used is not particularly limited as long as it is sufficient to dissolve the crude tetracarboxylic dianhydride and varies depending on the solubility parameter of the organic solvent. 1 to 30 parts by weight, especially 3 to 15 parts by weight per 1 part by weight of the product. If the amount of the organic solvent used is too small, a high temperature is required to dissolve the tetracarboxylic dianhydride, and there is a high risk that the tetracarboxylic dianhydride causes a side reaction during the dissolution and the purity is lowered. . Too much causes a problem in economy.

[Acid anhydride added during recrystallization]
In the present invention, it is preferable to perform recrystallization by adding an acid anhydride at the time of recrystallization in order to prevent the acid anhydride ring from being opened at the time of recrystallization. The acid anhydride is not particularly limited as long as it is dissolved in the solvent used for recrystallization and does not substantially react with the target tetracarboxylic dianhydride. Further, acid anhydrides having 4 to 10 carbon atoms such as propionic anhydride and maleic anhydride are used.
These may be used alone or in combination of two or more.

  The usage-amount of these acid anhydrides is 0.1-2 molar equivalent with respect to 1 mol of tetracarboxylic dianhydrides which are a target object normally. If the amount of acid anhydride used is too small, the ring-opening reaction during recrystallization cannot be sufficiently prevented, and if too much, the amount remaining in tetracarboxylic dianhydride increases and inhibits the polymerization reaction. It becomes a factor.

[Recrystallization operation]
Specifically, the recrystallization is performed by adding a predetermined amount of the above-mentioned organic solvent and, preferably, the above-mentioned acid anhydride to the crude tetracarboxylic dianhydride, and dissolving it by heating. If the heating temperature at this time is too high, there is a high risk that the tetracarboxylic dianhydride will cause a side reaction during the dissolution and the purity will decrease. Therefore, it is usually 40 to 200 ° C, particularly 60 to 150 ° C.

  After the crude tetracarboxylic dianhydride is dissolved by heating, a poor solvent of tetracarboxylic dianhydride is added and cooled to precipitate the target tetracarboxylic dianhydride.

  Examples of the poor solvent for tetracarboxylic dianhydride used here include aromatic hydrocarbons such as toluene and xylene, and aliphatic hydrocarbons such as hexane and heptane. These may be used alone or in combination of two or more.

  The usage-amount of a poor solvent is 0.2-5 weight part normally with respect to a recrystallization solvent. If the amount used is too small, the precipitation efficiency of the target product is poor, and if it is too large, sufficient purity cannot be obtained.

In addition, although cooling after heating and melting may be allowed to cool, accelerated cooling with a refrigerant or the like may be performed as necessary.
Crystals precipitated by recrystallization are solid-liquid separated according to a conventional method and then dried.

  Drying of the solid-liquid separated crystals is usually performed at 20 to 200 ° C., and this drying is performed under vacuum or reduced pressure as necessary.

<Purity of tetracarboxylic dianhydride>
The purified tetracarboxylic dianhydride obtained according to the method of the present invention is usually an acid dianhydride in which the content of the monoacid anhydride represented by the general formula (3) is represented by the general formula (1). 1 mol% or less, preferably 0.5 mol% or less, and particularly preferably one in which the monoanhydride is substantially not detected. The abundance of this monoacid anhydride can be detected from the peak of the ¹ H-NMR spectrum.

[Production of polymer]
The high-purity tetracarboxylic dianhydride produced as described above is suitably used for the production of polymers such as alicyclic polyesterimides, and has excellent polymerization reactivity and high characteristics of alicyclic polyester. An imide can be produced.

  In order to produce an alicyclic polyesterimide, the tetracarboxylic dianhydride produced as described above is reacted with substantially equimolar diamines in a polymerization solvent to produce an alicyclic polyesterimide. A precursor is produced. Here, tetracarboxylic dianhydride may be used individually by 1 type, and may use 2 or more types together. In addition to the high-purity tetracarboxylic dianhydride of the present invention, it is possible to mix and use acid dianhydrides having other structures without limitation. In this case, examples of the acid dianhydride that can be used in addition to the ester group-containing alicyclic tetracarboxylic dianhydride include aromatic dianhydrides having one benzene ring such as pyromellitic acid, 3 ′, 4,4′-biphenyltetracarboxylic dianhydride (BPDA), 2,3 ′, 3,4′-biphenyltetracarboxylic dianhydride (a-BPDA), 3,3 ″, 4 4'-diphenylsulfone tetracarboxylic dianhydride (DSDA), 3,3 ', 4,4'-benzophenone tetracarboxylic dianhydride (BTDA), 2,2', 3,3'-benzophenone tetracarboxylic acid Dianhydride, 3,3 ′, 4,4′-oxydiphthalic anhydride (ODPA), bis (2,3-dicarboxyphenyl) -terdioic anhydride (a-ODPA), bis (3,4 -Dicarboxyphenyl) ether Dianhydride, bis (3,4-dicarboxyphenyl) methane dianhydride, 2,2′-bis (3,4-dicarboxyphenyl) propane dianhydride (BDCP), 2,2′-bis (2,3-dicarboxyphenyl) propane dianhydride, 2,2′-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride (BDCF), 2,2′-bis (2,3- Aromatic dianhydrides having two benzene rings such as dicarboxyphenyl) hexafluoropropane dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalene Aromatic dianhydrides having a naphthalene skeleton such as tetracarboxylic dianhydride and 1,4,5,8-naphthalene tetracarboxylic dianhydride, 2,3,6,7-anthracene tetracarboxylic dianhydride 1 Aromatic dianhydride having an anthracene skeleton such 2,5,6-anthracene tetracarboxylic acid dianhydride as an example.

  On the other hand, examples of alicyclic acid anhydrides that can be additionally used include chained aliphatic tetracarboxylic acids such as 1,2,3,4-butanetetracarboxylic dianhydride and ethylenetetracarboxylic dianhydride. Acid dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,4, 5-cyclopentanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, bicyclo [2.2. 2] octa-7-ene-2,3,5,6-tetracarboxylic dianhydride, dicyclohexyl-3,4,3 ′, 4′-tetracarboxylic dianhydride (BPDA hydrogenated product), 2, 3,5-tricarboxycyclope Tylacetic dianhydride, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic dianhydride, bicyclo [3,3,0] octane-2,4,6,8- And tetracarboxylic dianhydride having an alicyclic structure such as tetracarboxylic dianhydride.

  The use ratio of these acid dianhydrides and the high purity tetracarboxylic acid anhydride of the present invention can be arbitrarily set depending on the physical properties of the resin to be obtained. The amount used is preferably 5 mol% or more, more preferably 10 mol% or more.

  The diamine used for producing the alicyclic polyesterimide precursor according to the present invention is freely selected as long as the polymerization reactivity during the production of the precursor and the required characteristics of the alicyclic polyesterimide are not significantly impaired. Is possible. Specific examples of diamines that can be used include aromatic diamines such as 3,5-diaminobenzotrifluoride, 2,5-diaminobenzotrifluoride, 3,3′-bistrifluoromethyl-4,4′-diamino. Biphenyl, 3,3′-bistrifluoromethyl-5,5′-diaminobiphenyl, bis (trifluoromethyl) -4,4′-diaminodiphenyl, bis (fluorinated alkyl) -4,4′-diaminodiphenyl, dichloro -4,4'-diaminodiphenyl, dibromo-4,4'-diaminodiphenyl, bis (fluorinated alkoxy) -4,4'-diaminodiphenyl, diphenyl-, 4'-diaminodiphenyl, 4,4'bis ( 4-aminotetrafluorophenoxy) tetrafluorobenzene, 4,4′-bis (4-aminoteto) Fluorophen) octafluorobiphenyl, 4,4′-binaphthylamine, o-, m-, p-phenylenediamine, 2,4-diaminotoluene, 2,5-diaminotoluene, 2,4-diaminoxylene, 2, 4-diaminodurene, dimethyl-4,4′-diaminodiphenyl, dialkyl-4,4′-diaminodiphenyl, dimethoxy-4,4′-diaminodiphenyl, diethoxy-4,4′-diaminodiphenyl, 4,4 ′ -Diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminobenzophenone, 3, 3′-diaminobenzophenone, 1,3-bis (3-aminophen Noxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4-aminophenoxy) biphenyl, bis (4 (3- Aminophenoxy) phenyl) sulfone, bis (4- (4-aminophenoxy) phenyl) sulfone, 2,2-bis (4- (4-aminophenoxy) phenyl) propane, 2,2-bis (4- (4- Aminophenoxy) phenyl) hexafluoropropane, 2,2-bis (4- (3-aminophenoxy) phenyl) propane, 2,2-bis (4- (3-aminophenoxy) phenyl) hexafluoropropane, 2,2-bis (4- (4-amino-2-trifluoromethylphenoxy) phenyl) hexafluoropropane, 2,2-bis (4- (3-amino-5-trifluoromethylphenoxy) phenyl) hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 2,2-bis (3-aminophenyl) hexafluoropropane, 2,2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane, 2,2 bis (3-amino-4-methylphenyl) hexafluoropropane, 4,4′-bis (4-aminophenoxy) ) Octafluorobiphenyl, 4,4′-diaminobenzanilide and the like can be exemplified, and two or more of these can be used in combination.

  Examples of the aliphatic diamine include 4,4′-methylenebis (cyclohexylamine), isophoronediamine, trans-1,4-diaminocyclohexane, cis-1,4-diaminocyclohexane, 1,4-cyclohexanebis (methylamine), 2,5-bis (aminomethyl) bicyclo [2.2.1] heptane, 2,6-bis (aminomethyl) bicyclo [2.2.1] heptane, 3,8-bis (aminomethyl) tricyclo [5 .2.1.0] decane, 1,3-diaminoadamantane, 2,2-bis (4-aminocyclohexyl) propane, 2,2-bis (4-aminocyclohexyl) hexafluoropropane, 1,3-propanediamine 1,4-tetramethylenediamine, 1,5-pentamethylenediamine, 1,6-hexamethylenedia Emissions, 1,7 heptamethylene diamine, 1,8-octamethylene diamine, 1,9-nonamethylenediamine, and the like. Two or more of these may be used in combination, or may be used in combination with the aromatic diamine listed above.

Furthermore, siloxane group-containing diamines such as 1,3-bis (3-aminopropyl) -1,1,3,3-tetramethyldisiloxane can also be used.
Among these diamines, aromatic diamines include mononuclear phenylenediamine compounds such as o-, m-, and p-phenylenediamine, 4,4'-diaminodiphenyl, 4,4'-diaminodiphenylsulfone, 4,4. Diaminodiphenyl compounds such as' -diaminodiphenylmethane and 4,4'-diaminodiphenyl ether are preferable. Among them, p-phenylenediamine, 4,4'-diaminodiphenyl ether, More preferred is 4,4′-diaminodiphenyl. As the aliphatic diamine, alicyclic diamines such as 4,4′-methylenebis (cyclohexylamine), trans-1,4-diaminocyclohexane, isophoronediamine and the like are preferable because they have a ring structure and are easily available. The resin from which trans-1,4-diaminocyclohexane is obtained is more preferable because of good physical properties.
These may be used alone or in combination of two or more.

  The ratio of tetracarboxylic dianhydride and diamine is preferably 1: 0.8 to 1.2 in terms of molar ratio. As in the normal polycondensation reaction, the closer the molar ratio is to 1: 1, the higher the molecular weight of the polyamic acid obtained.

  If the reaction temperature is too low, the solubility of the reagent is lowered, a sufficient reaction rate cannot be obtained, and if it is too high, it is difficult to control the progress of the reaction. The lower limit is −20 ° C., preferably −10 ° C., more preferably 0 ° C., and the upper limit is 150 ° C., preferably 100 ° C., more preferably 60 ° C.

  Although the reaction time can be adopted without any particular limitation, in order to achieve a sufficient reagent conversion rate, the lower limit is 10 minutes, preferably 30 minutes, more preferably 1 hour, and the upper limit is not particularly limited, but the reaction is completed. There is no need to extend the reaction time more than necessary. For example, 100 hours, preferably 50 hours, and more preferably 30 hours are employed.

  The polymerization reaction is performed using a solvent. As the solvent used in this case, there is no problem as long as the diamine as the raw material monomer and the alicyclic tetracarboxylic acid of the present invention do not react with the solvent, and these raw materials dissolve, and the structure is particularly limited. Not. Specifically, amide solvents such as N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, γ-butyrolactone, γ-valerolactone, δ-valerolactone, γ-caprolactone, ε -Cyclic ester solvents such as caprolactone, α-methyl-γ-butyrolactone, carbonate solvents such as ethylene carbonate and propylene carbonate, lactam solvents such as caprolactam, ether solvents such as dioxane, glycol solvents such as triethylene glycol, m- Phenolic solvents such as cresol, p-cresol, 3-chlorophenol, 4-chlorophenol, 4-methoxyphenol, 2,6-dimethylphenol, acetophenone, 1,3-dimethyl-2-imidazolidinone, sulfolane , Dimethyl Sulfoxide, tetramethyl urea are preferably employed. In addition, other common organic solvents such as phenol, o-cresol, butyl acetate, ethyl acetate, isobutyl acetate, propylene glycol methyl acetate, ethyl cellosolve, butyl cellosolve, 2-methyl cellosolve acetate, ethyl cellosolve acetate, butyl cellosolve acetate , Tetrahydrofuran, dimethoxyethane, diethoxyethane, dibutyl ether, diethylene glycol dimethyl ether, methyl isobutyl ketone, diisobutyl ketone, cyclohexanone, methyl ethyl ketone, acetone, butanol, ethanol, xylene, toluene, chlorobenzene, terpene, mineral spirit, petroleum naphtha A solvent etc. can also be added and used. Of these, aprotic solvents such as N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, dimethyl sulfoxide, and γ-butyrolactone are preferred because of the high solubility of the raw materials.

  The solvent is preferably used in such an amount that the weight concentration of the total amount of the tetracarboxylic dianhydride and diamine as raw materials falls within the following range. That is, the concentration is 0.1% by weight or more, preferably 1% by weight or more, more preferably 5% by weight or more, and the upper limit is not particularly limited, but 80% by weight from the viewpoint of solubility of tetracarboxylic dianhydride. Hereinafter, preferably 50 wt% or less, more preferably 30 wt% or less is employed. By carrying out polymerization in the concentration range of this tetracarboxylic dianhydride, a polyimide precursor solution having a uniform and high degree of polymerization can be obtained. In order to impart film toughness to the target polyesterimide, the degree of polymerization of the polyesterimide precursor is preferably as high as possible. When polymerization is performed at a concentration lower than the above concentration range, the degree of polymerization of the polyimide precursor is sufficient. Is not preferable, and the finally obtained polyimide film may be brittle. When an alicyclic diamine is used as the diamine, a higher polymerization concentration requires a longer polymerization time until the formed salt dissolves and disappears, which may lead to a decrease in productivity.

If necessary, inorganic salts may be used as a catalyst in the production of the precursor. The inorganic salts used in this, for example LiCl, NaCl, alkali metal halide such as LiBr, alkaline earth metal halides such as CaCl _2, metal halide such as ZnCl ₂ and the like. Of these, _LiCl, metal chlorides such as CaCl 2, ZnCl ₂ is particularly preferred.
The reaction is preferably carried out with stirring during the process.

  The intrinsic viscosity of the alicyclic polyesterimide precursor of the present invention thus obtained is not particularly limited, but as a preferred intrinsic viscosity, the lower limit is 0.3 dL / g, preferably 0.5 dL / g, Preferably, it is 0.7 dL / g. On the other hand, the upper limit is 5.0 dL / g, preferably 3.0 dL / g, more preferably 2.0 dL / g. Intrinsic viscosity is measured by the method described in the Examples section below.

  Examples of the method for synthesizing the alicyclic polyesterimide include (i) a method obtained from an alicyclic polyesterimide precursor and (ii) a method obtained without using an alicyclic polyesterimide precursor. And (i) As a method obtained from an alicyclic polyesterimide precursor, there are a heating imidization method and a chemical imidization method. However, the production method of the alicyclic polyesterimide of the present invention is not particularly limited to the production method described below.

(I) Method Obtained from Alicyclic Polyesterimide Precursor The alicyclic polyesterimide of the present invention can be produced by subjecting the alicyclic polyesterimide precursor obtained by the above method to a cyclization imidization reaction. it can.
At this time, the manufacturable form of the alicyclic polyesterimide is a film, a powder, a molded body and a solution.

  An alicyclic polyesterimide film can be produced, for example, as follows. First, the polymerization solution (varnish) of the alicyclic polyesterimide precursor is cast and applied onto a substrate such as glass, copper, aluminum, silicon, a quartz plate, a stainless plate, or a Kapton film. As a method of coating, the alicyclic polyesterimide solution obtained as described above is dropped onto the above-mentioned substrate and the solution is stretched on a support having a fixed height, thereby extending the solution to a uniform height. Can be applied. At this time, it may be performed using a device such as a doctor blade. As other coating methods, any method capable of coating the solution with a predetermined thickness, such as a spin coating method, a printing method, and an ink jet method, can be employed without any limitation.

  Since the coating film thus applied contains a solvent, it is then dried. The lower limit of the drying temperature employed at that time is usually 20 ° C., preferably 40 ° C., more preferably 60 ° C. On the other hand, the upper limit is 200 ° C, preferably 150 ° C, more preferably 100 ° C.

The drying time can be used without particular limitation as long as the solvent is removed to some extent, but the lower limit is 10 minutes, preferably 30 minutes, more preferably 1 hour, and the upper limit is not particularly limited, but 50 hours, preferably 30 Time, more preferably 10 hours, is employed.
Drying may be performed under reduced pressure. The degree of reduced pressure employed at that time is usually 0.05 MPa or less, preferably 0.01 MPa or less, more preferably 0.001 MPa or less.

  The dried alicyclic polyesterimide precursor film thus obtained is imidized by heating on a substrate in a vacuum, in an inert gas such as nitrogen, or in air at a high temperature. This method is called heat imidization.

  The lower limit of the temperature employed at this time is 180 ° C., preferably 200 ° C., more preferably 250 ° C. On the other hand, the upper limit is 500 ° C., preferably 400 ° C., more preferably 350 ° C. If the heating temperature is 180 ° C. or less, the cyclization reaction of the cyclization imidation reaction is incomplete, which is not preferable, and if it is too high, the produced alicyclic polyimide ester film may be colored. Therefore, it is not preferable. The imidization is preferably performed in a vacuum or in an inert gas, but may be performed in air if the temperature of the imidization reaction is not too high. The degree of reduced pressure employed when the heat imidization is performed under reduced pressure is usually 0.05 MPa or less, preferably 0.01 MPa or less, and more preferably 0.001 MPa or less.

  The time for which the cyclization imidation proceeds sufficiently is adopted as the heating time, but usually the lower limit is 5 minutes, preferably 10 minutes, more preferably 20 minutes, and the upper limit is not particularly limited, but 20 hours, preferably 10 hours, more preferably 5 hours are employed.

EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to these Examples, unless the summary is exceeded.
In the following, the NMR spectrum of tetracarboxylic dianhydride and the method for measuring the intrinsic viscosity of the polyimide precursor are as follows.

^<1 H-NMR spectrum>
The product was dissolved in deuterated dimethyl sulfoxide, and a ¹ H-NMR spectrum was measured using a proton resonance frequency 400 MHz NMR spectrometer.

<Intrinsic viscosity>
The 0.5 wt% polyimide precursor solution was measured at 30 ° C. using an Ostwald viscometer.

[Synthesis Example 1]
As a production example of the tetracarboxylic dianhydride of the present invention, 1,4-bis (4′-oxa-3 ′, 5′-dioxotricyclo [5.2.1.0] represented by the following structural formula The synthesis of ^2,6 ] -decan-8′-ylcarboxy) benzene will be described.

  Norbornane-2-exo, 3-exo, 5-exo-tricarboxylic acid trimethyl ester, which is a raw material for the synthesis of this product, can be synthesized by the method described in Japanese Patent No. 3342938.

(Synthesis of norbornane-2-exo, 3-exo, 5-exo-tricarboxylic acid)
In a reaction vessel equipped with a nitrogen inlet and a condenser, 45.1 g (167 mmol) of norbornane-2-exo, 3-exo, 5-exo-tricarboxylic acid trimethyl ester, 45.0 g of sulfolane, and 16.7 g of 98% sulfuric acid were added to water 74. An aqueous solution dissolved in 0.7 g was charged and heated at 104 ° C. for 5 hours in a nitrogen atmosphere. During this time, 25 g of water was added per hour, and the distilled methanol and water were removed from the system. After the reaction, the reaction mixture was cooled, 225 g of water was added, and extraction was performed with toluene (300 mL × 4 times). After 95 g of sodium chloride was added to the aqueous layer, extraction was performed with a mixed solvent of tetrahydrofuran / ethyl acetate (1/1) (volume ratio) (300 mL × 2 times, 150 mL × 1 time). The obtained tetrahydrofuran / ethyl acetate layer was washed with saturated brine (150 mL × 1 time), and then the solvent was concentrated and washed with 60 ml of toluene to give crude norbornane-2-exo, 3-exo which is a white solid. , 5-2.9-tricarboxylic acid 42.9 g was obtained. To this crude product, 40 ml of tetrahydrofuran was added and heated to 75 ° C. to dissolve, then 100 ml of toluene was added and allowed to cool to 20 ° C. The precipitated crystals were filtered and dried under vacuum at 80 ° C. for 5 hours to obtain 21.7 g of purified norbornane-2-exo, 3-exo, 5-exo-tricarboxylic acid (yield 57%).

(Synthesis of 5-exo-chloroformyl-norbornane-2-exo, 3-exo-dicarboxylic anhydride)
In a reaction vessel equipped with a nitrogen inlet and a condenser, 21.5 g (94.2 mmol) of norbornane-2-exo, 3-exo, 5-exo-tricarboxylic acid, 38 mg (0.52 mmol) of dimethylformamide, 0 with respect to the tricarboxylic acid 0.005 mol equivalent), 130 mL of toluene was added as a solvent, and the internal temperature was heated to 70 ° C. To this was added 50.5 g (424 mmol; 4.5 mol equivalent to tricarboxylic acid) of thionyl chloride, and the mixture was refluxed for 3 hours in a nitrogen atmosphere. Thereafter, excess thionyl chloride and toluene were distilled off under reduced pressure to obtain a light brown crude product. To this, 220 mL of heptane was added and washed to obtain 20.5 g (yield 95%) of 5-exo-chloroformyl-norbornane-2-exo, 3-exo-dicarboxylic acid anhydride as a white solid.

(Synthesis of crude 1,4-bis (4′-oxa-3 ′, 5′-dioxotricyclo [5.2.1.0 ^2,6 ] -decan-8′-ylcarboxy) benzene)
4.88 g (44.3 mmol) of hydroquinone, 28.1 g of pyridine, and 100 mL of tetrahydrofuran were dissolved in a reaction vessel under a nitrogen atmosphere. After cooling this to 4 ° C. in an ice bath, 20.3 g of 5-exo-chloroformyl-norbornane-2exo, 3exo-dicarboxylic acid anhydride (88.8 mmol; 2.0 molar equivalent to hydroquinone) A solution obtained by adding 100 mL of tetrahydrofuran to the solution was added dropwise with a dropping funnel over 1 hour, and further stirred for 5 hours to obtain a white precipitate. The produced white precipitate was filtered off, suspended in 250 mL of water and filtered, and further thoroughly washed with water to completely remove the hydrochloride. The resulting product was vacuum-dried at 100 ° C. for 6 hours to give 17.7 g (80% yield) of crude 1,4-bis (4′-oxa-3 ′, 5′-dioxo as white powder. Tricyclo [5.2.1.0 ^2,6 ] -decan-8′-ylcarboxy) benzene was obtained. From the ¹ H-NMR chart of this product, it was found that this crude product contained 5.4 mol% of pyridine with respect to the target product. Furthermore, a peak corresponding to 5.1 mol% was observed in the range of 6 to 7 ppm with respect to 1 mol of the target hydrogen atom.

[Example 1]
Crude 1,4-bis (4′-oxa-3 ′, 5′-dioxotricyclo [5.2.1.0 ^2,6 ] -decan-8′-ylcarboxy) obtained in Synthesis Example 1 12.0 g of γ-butyrolactone (solubility parameter: 25.8 MPa ^1/2 ) was added to 2.00 g of benzene and heated to 135 ° C. to dissolve. To this was added 12.0 g of toluene, and the mixture was allowed to cool to 20 ° C. The precipitated crystals were filtered and dried under vacuum at 150 ° C. for 6 hours to obtain 1.32 g of the purified desired product. In the ¹ H-NMR chart of this product, a peak derived from pyridine and a peak in the range of 6 to 7 ppm were not observed.

A polyimide was synthesized using the resulting purified acid dianhydride.
In a 50 mL three-necked flask under nitrogen atmosphere, 0.109 g (1.01 mmol) of p-phenylenediamine was dissolved in 2.01 g of N, N-dimethylacetamide (DMAc), and the resulting acid dianhydride was obtained. 0.500 g (1.01 mmol) of the product was added and stirred at room temperature. On the way, when the viscosity of the reaction solution increased, DMAc was added each time to adjust the viscosity. Stirring was continued for a total of 6 hours to obtain a transparent and viscous alicyclic polyesterimide precursor solution. The final concentration of this was 11.0% by weight and the intrinsic viscosity was 1.55 dL / g.

  This reaction solution was applied to a glass substrate, dried at 60 ° C. for 0.5 hours in a nitrogen atmosphere, and then heated to 150 ° C. at a rate of 2.5 ° C./min under a reduced pressure of 0.001 MPa. The time was maintained, and then the temperature was raised to 300 ° C. at a rate of 2.5 ° C./minute and held for 1 hour.

[Example 2]
Crude 1,4-bis (4′-oxa-3 ′, 5′-dioxotricyclo [5.2.1.0 ^2,6 ] -decan-8′-ylcarboxy) obtained in Synthesis Example 1 12.0 g of γ-butyrolactone (solubility parameter: 25.8 MPa ^1/2 ) and 0.42 g of acetic anhydride were added to 2.00 g of benzene and heated to 135 ° C. to dissolve. To this was added 12.0 g of toluene, and the mixture was allowed to cool to 20 ° C. The precipitated crystals were filtered and dried under vacuum at 150 ° C. for 15 hours to obtain 1.48 g of the purified desired product. In the ¹ H-NMR chart of this product, a peak derived from pyridine and a peak in the range of 6 to 7 ppm were not observed.

  In the same manner as in Example 1, when polyimide was synthesized using the obtained purified dianhydride, the intrinsic viscosity of the polyimide precursor was 1.46 dL / g. When the polymerization reaction solution was similarly heat-treated, it was colorless. A transparent polyimide film was obtained.

[Example 3]
Crude 1,4-bis (4′-oxa-3 ′, 5′-dioxotricyclo [5.2.1.0 ^2,6 ] -decan-8′-ylcarboxy) obtained in Synthesis Example 1 10.8 g of cyclopentanone (solubility parameter: 21.3 MPa ^1/2 ) was added to 0.800 g of benzene, and the mixture was heated to 129 ° C. and dissolved. To this was added 12.0 g of toluene and the mixture was allowed to cool to 25 ° C. The precipitated crystals were filtered and dried under vacuum at 150 ° C. for 6 hours to obtain 0.60 g of the purified desired product. In the ¹ H-NMR chart of this product, a peak derived from pyridine and a peak in the range of 6 to 7 ppm were not observed.

  In the same manner as in Example 1, when polyimide was synthesized using the obtained purified dianhydride, the intrinsic viscosity of the polyimide precursor was 1.28 dL / g. When the polymerization reaction solution was similarly heat-treated, it was colorless. A transparent polyimide film was obtained.

[Comparative Example 1]
Crude 1,4-bis (4′-oxa-3 ′, 5′-dioxotricyclo [5.2.1.0 ^2,6 ] -decan-8′-ylcarboxy) obtained in Synthesis Example 1 When benzene was used without purification and polyimide was synthesized in the same manner as in Example 1, the intrinsic viscosity of the polyimide precursor was as low as 0.72 dL / g.

[Comparative Example 2]
Crude 1,4-bis (4′-oxa-3 ′, 5′-dioxotricyclo [5.2.1.0 ^2,6 ] -decan-8′-ylcarboxy) obtained in Synthesis Example 1 Acetic anhydride (solubility parameter: 21.1 MPa ^1/2 ) 15.1 g was added to 0.502 g of benzene and heated to 140 ° C., but it was not completely dissolved and recrystallization purification could not be performed.

Claims (7)

A method for producing a tetracarboxylic dianhydride represented by the following general formula (1), wherein the solubility parameter δ (unit: MPa) represented by the following formula (2) under the measurement conditions of 1 atm and 25 ° C. ^A method for producing a high-purity acid dianhydride, wherein recrystallization is performed in the presence of an organic solvent having a ^1/2 ) of 21.3 or more.

(In the formula (1), A represents a divalent group.
X ¹ , X ² , X ³ , X ⁴ , X ⁵ , and X ⁶ are each independently a hydrogen atom, halogen atom, nitrile group, nitro group, alkyl group, alkenyl group, alkynyl group, alkoxy group, amino group, or Represents an amide group. However, these groups may further have a substituent, and in the case of a carbon-containing group, the carbon number is 10 or less.
n represents an integer of 0, 1 or 2. )
δ = (ΔH / V) ^1/2 (2)
(In the formula (2), ΔH and V are respectively the molar evaporation heat (unit: J / mol) and the molar volume (unit: cm ³ / mol) of the organic solvent.)   The method for producing a high-purity acid dianhydride according to claim 1, wherein recrystallization is performed by adding an acid anhydride to the organic solvent.   The method for producing a high-purity acid dianhydride according to claim 2, wherein the acid anhydride is a carboxylic acid anhydride having 10 or less carbon atoms.   The high-purity acid dianhydride according to any one of claims 1 to 3, wherein the solvent used for recrystallization does not substantially react with the tetracarboxylic dianhydride represented by the general formula (1). Manufacturing method.   The method for producing a high-purity acid dianhydride according to any one of claims 1 to 4, wherein the solvent used for recrystallization has a boiling point at normal pressure of 100 ° C or higher. A tetracarboxylic dianhydride represented by the following general formula (1), wherein the content of the monoacid anhydride represented by the following general formula (3) is 1 mol with respect to the tetracarboxylic dianhydride. % Tetracarboxylic dianhydride characterized by being less than or equal to%.

(In the formula (1), A represents a divalent group.
X ¹ , X ² , X ³ , X ⁴ , X ⁵ , and X ⁶ are each independently a hydrogen atom, halogen atom, nitrile group, nitro group, alkyl group, alkenyl group, alkynyl group, alkoxy group, amino group, or Represents an amide group. However, these groups may further have a substituent, and in the case of a carbon-containing group, the carbon number is 10 or less.
n represents an integer of 0, 1 or 2. )

(In the formula (3), A, X ¹ , X ² , X ³ , X ⁴ , X ⁵ , X ⁶ , and n are as defined in the general formula (1).)   A polymer produced using the tetracarboxylic dianhydride according to claim 6.