JP2008163087A - Method for producing ester group-containing alicyclic tetracarboxylic acid dianhydride - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing an alicyclic polyesterimide having an excellent heat resistance and mechanical strength. <P>SOLUTION: The method for producing an ester group-containing alicyclic tetracarboxylic acid dianhydride comprises purification from tetracarboxylic acids represented by formulas (1)-(3) by using a mixed solvent of a ≤10C carboxylic acid anhydride and an inert organic solvent. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for producing an ester group-containing alicyclic tetracarboxylic dianhydride, and in particular, an ester group-containing alicyclic tetracarboxylic acid or an ester group-containing alicyclic tetracarboxylic acid monoanhydride as a reaction byproduct. Further, the present invention relates to a method for purifying an ester group-containing alicyclic tetracarboxylic acid containing a hydrochloride and obtaining a high-purity ester group-containing alicyclic tetracarboxylic dianhydride. The present invention also provides a high-purity ester group-containing alicyclic tetracarboxylic dianhydride obtained by this method and a high polymerization reactivity using the high-purity ester group-containing alicyclic tetracarboxylic dianhydride. The present invention relates to a method for producing an alicyclic polyesterimide having excellent heat resistance and mechanical strength.

  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, practically usable polyimides that are soluble in organic solvents are very limited, 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 has been increasing due to the demand for development in 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 liquid crystal display, a flexible substrate for EL display, and various optical property members used inside. However, there are currently no known materials having such physical properties.

  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).

  If this ester group-containing alicyclic tetracarboxylic dianhydride is derived from the fact that the acid anhydride group is bonded on the cyclohexane ring, this ester group-containing alicyclic tetracarboxylic dianhydride is By suppressing the pi-electron conjugation and the intramolecular / intermolecular charge transfer interaction in the alicyclic polyesterimide produced by using the alicyclic polyesterimide, it becomes possible to increase the transparency and decrease the dielectric constant. The ester bond in the alicyclic polyesterimide enables alkali etching when fine processing such as through-hole formation is required.

  In Patent Document 1, ester group-containing alicyclic tetracarboxylic dianhydride is synthesized by reacting nuclear hydrogenated trimellitic anhydride chloride with a diol in the presence of a base. As the base, an organic amine is generally used, and an amine hydrochloride equivalent to the product in an equimolar amount is precipitated during the reaction. If the target product is insoluble in the reaction solvent, the reaction mixture is filtered to remove the hydrochloride from the mixture of hydrochloride and target product by washing with water. It was difficult to remove. Moreover, there also existed a problem that acid anhydride hydrolyzes by wash | cleaning with water, and carboxylic acid produces | generates.

On the other hand, when the target product is soluble in the reaction solvent, the hydrochloride can be removed by filtering the reaction solution after the reaction, but it cannot be completely removed by itself. Further, the hydrochloride can be removed by washing the filtrate with water, but in this case, there is a problem that hydrolysis of the acid anhydride proceeds and a considerable amount of carboxylic acid is produced.
Furthermore, when an ester group-containing alicyclic tetracarboxylic dianhydride mixed with such a hydrochloride or carboxylic acid is reacted with a diamine, the polyamic acid has low polymerizability and has excellent heat resistance and mechanical strength. A film could not be obtained.
Japanese Patent Application No. 2006-152772 Proceedings of Macromolecules Conference, 53, 4115 (2004) Macromolecules, 24,5001 (1991) Macromolecules, 32, 4933 (1999)

  The object of the present invention is to solve the problems of the conventional production method, and to produce a high purity ester group-containing alicyclic tetracarboxylic dianhydride with little contamination with hydrochloride, tetracarboxylic acid or monoanhydride, It is providing the high characteristic alicyclic polyesterimide using purity ester group containing alicyclic tetracarboxylic dianhydride.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have converted ester group-containing alicyclic tetracarboxylic acids containing impurities by-produced by reaction into carboxylic acid anhydrides having 10 or less carbon atoms and the carboxylic acid anhydrides. By purifying using an inert organic solvent excellent in compatibility with the product, the reaction by-product tetracarboxylic acid, monoanhydride, and hydrochloride are highly removed, and only the dianhydride is obtained. It was found that it can be efficiently recovered.

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

（式（１）〜（３）中、Ａは２価の基を示す。） [1] The ester group-containing alicyclic tetracarboxylic acid represented by the following general formula (1) whose purity is improved from the ester group-containing alicyclic tetracarboxylic acids represented by the following general formulas (1) to (3) The method for producing an acid dianhydride is characterized by purifying using a mixed solvent containing a carboxylic acid anhydride having at least 10 carbon atoms and an inert organic solvent miscible with the carboxylic acid anhydride in an indefinite ratio. To produce an ester group-containing alicyclic tetracarboxylic dianhydride.

(In formulas (1) to (3), A represents a divalent group.)

[2] The method for producing an ester group-containing alicyclic tetracarboxylic dianhydride according to [1], wherein the carboxylic acid anhydride is acetic anhydride.

[3] The [1] or [2], wherein the inert organic solvent is one or more selected from the group consisting of carboxylic acids, cyclic esters, amides, and hydrocarbons. A method for producing an ester group-containing alicyclic tetracarboxylic dianhydride.

[4] The inert organic solvent is one or more selected from the group consisting of acetic acid, γ-butyrolactone, N-methylpyrrolidone, N, N-dimethylacetamide, and toluene. 3] The manufacturing method of ester group containing alicyclic tetracarboxylic dianhydride as described in 3].

[5] The mixing ratio of the carboxylic acid anhydride and the inert organic solvent is 0.1 to 30 parts by weight of the inert organic solvent with respect to 1 part by weight of the carboxylic acid anhydride. [4] The method for producing an ester group-containing alicyclic tetracarboxylic dianhydride according to any one of [4].

（式（１）〜（３）中、Ａは２価の基を示す。） [6] An ester group-containing alicyclic tetracarboxylic acid dianhydride represented by the following general formula (1), wherein the nitrogen content is 800 ppm or less. Carboxylic dianhydride.

(In formulas (1) to (3), A represents a divalent group.)

[7] A process for producing an alicyclic polyesterimide, wherein the ester group-containing alicyclic tetracarboxylic dianhydride according to [6] is reacted with a diamine and then imidized.

  Purifying ester group-containing alicyclic tetracarboxylic acids according to the present invention using a mixed solvent containing a carboxylic acid anhydride having 10 or less carbon atoms and an inert organic solvent miscible with the carboxylic acid anhydride in a non-stoichiometric ratio. As a result, a high-purity acid dianhydride with less nitrogen content and less carboxylic acid contamination can be obtained. This is the effect of increasing the solubility of the nitrogen-containing hydrochloride while ring-closing the partially opened dicarboxylic acid of the ester group-containing alicyclic tetracarboxylic acid to the acid anhydride with a carboxylic acid anhydride having 10 or less carbon atoms. Because there is.

  When the high-purity ester group-containing alicyclic tetracarboxylic dianhydride obtained by purification in this way is reacted with diamine, a polyamic acid having good polymerizability is produced, heat resistance is high, and mechanical strength is high. A high alicyclic polyesterimide can be obtained.

  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. “Class” as used in the present invention means “compound”. For example, tetracarboxylic acids and diamines mean a tetracarboxylic acid compound and a diamine compound, respectively.

<Ester group-containing alicyclic tetracarboxylic acids>
The ester group-containing alicyclic tetracarboxylic acids to be purified in the present invention are those represented by the following general formula (1) and those represented by the following general formula (2). One end forms a condensed ring, the other end is a dicarboxylic acid, and a tetracarboxylic acid represented by the following general formula (3).

（式（１）〜（３）中、Ａは２価の基を示す。）

(In formulas (1) to (3), A represents a divalent group.)

The structure of A in the general formulas (1) to (3) is not particularly limited as long as it is bonded to a carboxy group so as to form the structure at two positions.
Specifically, in the general formulas (1) to (3), A may be any divalent group. That is, these compounds are characterized by a structure having two cyclohexane rings and two ester groups connecting them, and by having this structure, high transparency and high toughness when made into an alicyclic polyesterimide resin. , 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, but is preferably a divalent group having an aromatic group and / or an aliphatic 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.

  As 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.

<Carboxylic anhydride having 10 or less carbon atoms>
The carboxylic acid anhydride having 10 or less carbon atoms used for the purification of the ester group-containing alicyclic tetracarboxylic acids is not particularly limited. However, if the boiling point is high, it is difficult to remove at the time of drying. ~ 6 are preferred.

Examples of such carboxylic acid anhydrides include acetic anhydride, trifluoroacetic anhydride, propionic anhydride, and the like. Among these, it is particularly inexpensive, has a low boiling point, and is easy to remove during drying. It is preferable to use acetic anhydride.
These carboxylic acid anhydrides may be used alone or in combination of two or more.

  The amount of these carboxylic acid anhydrides used is such that the lower limit is 1 mole, preferably 3 moles relative to the 1,2-dicarboxyl group contained in the ester group-containing alicyclic tetracarboxylic acids to be purified. The upper limit is not particularly limited, but is 10000 mol times, preferably 5000 mol times, more preferably 1000 mol times from an economic viewpoint.

<Inert organic solvent>
The inert organic solvent is basically inactive under the operating conditions employed in purification with respect to the ester group and acid anhydride group of the ester group-containing alicyclic tetracarboxylic acid to be purified, In the present invention, such an inert organic solvent that is miscible with the above-described carboxylic acid anhydride in an indefinite ratio is used. In addition, mixing with a carboxylic acid anhydride at an indefinite ratio means that it can be sufficiently compatible with a wide mixing ratio of, for example, carboxylic acid anhydride: inert organic solvent = 1: 1000 to 1000: 1 (weight ratio). Point to.

  Such inert organic solvents include carboxylic acids, cyclic esters, amides, hydrocarbons and the like.

  For example, examples of the carboxylic acid include those having 2 to 4 carbon atoms such as formic acid, acetic acid, trifluoroacetic acid, trichloroacetic acid, propionic acid, butyric acid, and among them, acetic acid is preferable in terms of availability and easy handling. .

  Examples of cyclic esters include those having 5 to 7 members or 4 to 5 carbon atoms such as γ-butyrolactone, α-methyl-γ-butyrolactone, δ-valerolactone, ε-caprolactone, and the like. γ-butyrolactone, α-methyl-γ-butyrolactone, δ-valerolactone, and the like are preferable, and γ-butyrolactone is preferable in terms of availability and easy handling.

  Examples of amides include cyclic amides having about 4 to 5 carbon atoms such as N-methylpyrrolidone, and chain amides having 3 to 5 carbon atoms such as N, N-dimethylformamide, N, N-dimethylacetamide, and trimethylacetamide. Among these, N-methylpyrrolidone and N, N-dimethylformamide are preferable in terms of availability and easy handling.

  Examples of the hydrocarbon include aromatic hydrocarbons having 7 to 8 carbon atoms such as toluene and xylene, and aliphatic hydrocarbons having 6 to 8 carbon atoms such as cyclohexane, n-hexane, n-heptane, and n-octane. Of these, toluene, xylene, n-hexane and the like are preferable.

  These inert organic solvents may be used individually by 1 type, and 2 or more types may be mixed and used for them.

<Mixing ratio of carboxylic anhydride and inert organic solvent>
The mixing ratio of the carboxylic acid anhydride and the inert organic solvent used for the purification of the ester group-containing alicyclic tetracarboxylic acid is 0.1 to 30 parts by weight of the inert organic solvent with respect to 1 part by weight of the carboxylic acid anhydride. It is preferable that If the amount of the inert organic solvent is less than this range, the carboxylic acid anhydride is difficult to dissolve, and if the amount is large, the dehydration reaction is insufficient and the carboxylic acid may remain. Preferably, the amount is 1 to 20 parts by weight, particularly 5 to 10 parts by weight, based on 1 part by weight of the carboxylic acid anhydride.

<Purification method>
In the present invention, for example, the ester group-containing alicyclic tetracarboxylic acid obtained by the reaction is heated and dissolved by adding the above carboxylic acid anhydride and an inert organic solvent, and then cooled and the precipitated solid is added. By separating and drying, a purified ester group-containing alicyclic tetracarboxylic dianhydride represented by the general formula (1) can be obtained.

  Here, there are no particular restrictions on the amounts of carboxylic anhydride and inert organic solvent used for the ester group-containing alicyclic tetracarboxylic acids, but carboxylic acid anhydride is usually used for 1 g of the ester group-containing alicyclic tetracarboxylic acids. 2 to 50 ml, particularly 4 to 30 ml in total (hereinafter, a mixture of carboxylic acid anhydride and inert organic solvent may be referred to as “purification solvent”). If the amount of the purification solvent used is less than this range, the dissolution is insufficient, and if it is more than this range, the amount of carboxylic acid anhydride obtained is reduced, which is uneconomical.

  The heating temperature for dissolving the ester group-containing alicyclic tetracarboxylic acids in the purification solvent is usually 80 to 145 ° C, preferably 90 to 140 ° C. When the heating temperature is lower than this range, dissolution is insufficient, and when the heating temperature is higher, the carboxylic acid anhydride is colored.

  Cooling after melting by heating may be allowed to cool, but accelerated cooling may be performed using a cooling device as necessary.

  The purified product obtained by solid-liquid separation is usually dried at 100 to 150 ° C., and this drying may be performed under vacuum or under reduced pressure as necessary.

  In addition, after cooling, a hydrocarbon solvent such as toluene may be further added to lower the solubility of the carboxylic acid anhydride, and may be precipitated. Aprotic polar solvents such as cyclic esters and amides have a high solubility of tetracarboxylic acid anhydride, and the amount of tetracarboxylic acid anhydride that is precipitated by ordinary dissolution recrystallization is small. In such a case, by adding a poor solvent such as toluene to reduce the solubility of the tetracarboxylic acid anhydride, the tetracarboxylic acid anhydride can be efficiently obtained without reducing the purity.

  In addition, prior to the purification operation of dissolution recrystallization using a purification solvent as described above, if tetracarboxylic anhydride is soluble in the reaction solvent, impurities derived from excessively added nuclear hydrogenated trimellitic anhydride chloride Even if it is mixed and tetracarboxylic acid anhydride is directly dissolved and recrystallized, a high purity product may not be obtained. In that case, hydrolyze with acid to obtain tetracarboxylic acid, and then perform ring closure treatment. May be.

  The acid used for hydrolysis of the acid anhydride ring of the tetracarboxylic acid anhydride is preferably a weak acid since hydrolysis of the ester group in the molecule proceeds when the acidity is high. Among weak acids, it is preferable to use carboxylic acid from the viewpoint of good solubility of the tetracarboxylic acid produced. Examples of carboxylic acids that can be used include those having 2 to 4 carbon atoms such as acetic acid, propionic acid, butyric acid, and acetic acid is particularly preferred.

  Carvone is used as an aqueous solution, and its concentration is usually 3 to 20% by weight, preferably 4 to 10% by weight. If the concentration is lower than this range, the reaction rate is slow, and if it is too high, the exchange reaction with the ester proceeds, which is not preferable.

  The reaction temperature during hydrolysis of the acid anhydride ring is usually 20 to 80 ° C, preferably 40 to 60 ° C. If the temperature is lower than this range, the reaction rate is slow, and if it is too high, hydrolysis of the ester proceeds, which is not preferable.

  The reaction time for hydrolysis of the acid anhydride ring is usually 0.2 to 3 hours, preferably 0.5 to 2 hours. If the reaction time is shorter than this range, hydrolysis of the acid anhydride is insufficient, and if it is too long, hydrolysis of the ester proceeds, which is not preferable.

  After the hydrolysis of the acid anhydride ring, the precipitated tetracarboxylic acid is filtered off and dissolved in a solvent immiscible with water in order to perform a water washing operation. As the solvent, ethyl acetate, which has high solubility and can be easily distilled off, is preferably used. By performing the washing operation, impurities derived from the nuclear hydrogenated trimellitic anhydride chloride are removed, and a high purity tetracarboxylic acid is obtained.

  After washing with water, the solvent is distilled off under reduced pressure to obtain purified tetracarboxylic acid, which is used for dissolution and recrystallization with the above-described purified solvent.

<Purity of ester group-containing alicyclic tetracarboxylic dianhydride>
The purified ester group-containing alicyclic tetracarboxylic dianhydride obtained according to the method of the present invention usually has a nitrogen content of 800 ppm or less, preferably 50 ppm or less.

That is, ester group-containing alicyclic tetracarboxylic acids obtained by reaction of nuclear hydrogenated trimellitic anhydride chloride with dihydric alcohol in the presence of organic amine as a base contain hydrochloride derived from organic amine. In general, the nitrogen content when the purification operation is not performed is about 820 to 7000 ppm, but according to the present invention, this can be greatly reduced.
In addition, although there is no restriction | limiting in particular about the minimum of nitrogen content, Usually, it is about 0.01 ppm.

When such an ester group-containing alicyclic tetracarboxylic dianhydride having a low nitrogen content is used, an alicyclic polyesterimide having a high molecular weight and excellent heat resistance and mechanical strength can be produced.
Note that the nitrogen content of the ester group-containing alicyclic tetracarboxylic dianhydride is measured by the method described in the Examples section below.

<Manufacture of alicyclic polyesterimide>
To produce an alicyclic polyesterimide, the ester group-containing alicyclic tetracarboxylic dianhydride purified as described above is reacted with substantially equimolar diamines in a polymerization solvent. To produce an alicyclic polyesterimide precursor. Here, ester group containing alicyclic tetracarboxylic dianhydride may be used individually by 1 type, and 2 or more types may be mixed and used for it. In addition to the ester group-containing alicyclic tetracarboxylic dianhydride, 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) terdioic anhydride, bis 3,4-dicarboxyphenyl) methane dianhydride, 2,2′-bis (3,4-dicarboxyphenyl) propane dianhydride (BDCP), 2,2′-bis (2,3-dicarboxy) Phenyl) propane dianhydride, 2,2′-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride (BDCF), 2,2′-bis (2,3-dicarboxyphenyl) hexafluoropropane Aromatic dianhydrides having two benzene rings such as dianhydrides, 2,3,6,7-naphthalene tetracarboxylic dianhydride, 1,2,5,6-naphthalene tetracarboxylic dianhydride, Aromatic dianhydrides having a naphthalene skeleton such as 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-anthracenetetracarboxylic dianhydride, 1,2,5, 6-Antra Aromatic dianhydride having an anthracene skeleton such emissions 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 tetracarboxylic acid anhydride of the present invention can be arbitrarily set depending on the physical properties of the resin to be obtained, but the use amount of the tetracarboxylic acid anhydride of the present invention is 5 mol%. The above is preferable, and it is more preferable to use 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.

Furthermore, siloxane group-containing diamines such as 1,3-bis (3-aminopropyl) -1,1,3,3-tetramethyldisiloxane can also be used.
Among these diamines, examples of aromatic diamines include mononuclear phenylenediamine compounds such as o-, m-, and p-phenylenediamine, 4,4′-diaminodiphenyl, 4,4′-diaminodiphenylsulfone, and 4,4. Diaminodiphenyl compounds such as' -diaminodiphenylmethane and 4,4'-diaminodiphenyl ether are preferred. Among these, 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 to be subjected to the reaction 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
Time, more preferably 30 hours, is 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, metal chlorides such as LiCl, CaCl ₂ and ZnCl ₂ are 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 of the present invention 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.

[Physical properties of alicyclic polyesterimide]
The glass transition point Tg (° C.) of the alicyclic polyesterimide of the present invention is usually 150 ° C., preferably 200 ° C., more preferably 250 ° C., and the upper limit is usually 500 ° C., preferably 450 ° C., more preferably. Is in the range of 400 ° C. and has high heat resistance.

The linear thermal expansion coefficient of the alicyclic polyesterimide of the present invention is usually 100 ppm / K or less, preferably 50 ppm / K or less, more preferably 30 ppm / K.
The polyesterimide of the present invention exhibits high solubility in a solvent. In particular, it dissolves well in the solvent used when synthesizing the alicyclic polyesterimide precursor described above, and can be easily made into a solution.

  In addition, the glass transition point and linear thermal expansion coefficient of alicyclic polyesterimide are measured by the method described in the item of the below-mentioned Example.

[Incorporation of inorganic filler into alicyclic polyesterimide]
By adding an inorganic filler to the alicyclic polyesterimide of the present invention, physical properties such as improved thermal stability can be improved.

  In this case, as the inorganic filler used, zirconium oxide, titanium oxide, zinc oxide, aluminum oxide, silicon dioxide, magnesium oxide, calcium oxide and other oxides, carbonates such as calcium carbonate and sodium carbonate, aluminum hydroxide, Examples thereof include hydroxides such as magnesium hydroxide, sulfates such as barium sulfate and calcium sulfate, nitrates, phosphates, silicates, and graphite.

  In addition, the amount of the inorganic filler is different depending on the physical properties to be improved, but if it is excessively large, problems such as loss of transparency and brittleness occur, and if it is too small, the inorganic filler is compounded. Since the effect of improving the physical properties cannot be sufficiently obtained, the content is preferably 5 to 95% by weight, particularly 10 to 80% by weight, based on the alicyclic polyesterimide.

For example, the inorganic filler may be blended as follows.
Add an inorganic filler to an alicyclic polyesterimide dissolved in a solvent such as N, N-dimethylacetamide and disperse it by stirring, or dissolve the alicyclic polyesterimide in a solvent in which an inorganic filler has been dispersed in advance. Dry the solvent. At this time, a dispersant can be used. As the dispersant, carboxylic acids such as acetic acid, caproic acid, caprylic acid, capric acid, succinic acid and phthalic acid are preferably used.

  Hereinafter, the present invention will be described more specifically with reference to examples.

  In the following, the nitrogen content in the ester group-containing alicyclic tetracarboxylic dianhydride, the intrinsic viscosity of the polyesterimide precursor, the glass transition point and the linear thermal expansion coefficient of the polyesterimide film are measured by the following methods. did.

<Nitrogen content>
It measured by TN-10 (made by Dia Instruments Co., Ltd.) by the oxygen combustion-chemiluminescence method.

<Intrinsic viscosity>
The 0.5 wt% polyesterimide precursor solution was measured at 30 ° C. using an Ubbelohde viscometer.
<Glass transition point>
Using a differential scanning calorimeter (DSC 6220) manufactured by SII NanoTechnology, the heating rate was 10 ° C./min. DSC measurement was performed under the conditions described above to determine the glass transition temperature.

<Linear thermal expansion coefficient: CTE>
The range of 100 to 200 ° C. from the elongation of the test piece at a load of 0.5 g / film thickness of 1 μm and a heating rate of 5 ° C./min by thermomechanical analysis using a Bruker Ax thermomechanical analyzer (TMA4000). The linear thermal expansion coefficient of the polyesterimide film was determined as an average value at.

[Comparative Example 1] Synthesis of Hydroquinone Hydrogenated Trimellitic Diester Acid Anhydride Crude A nuclear hydrogenated trimellitic anhydride chloride was synthesized as follows.
Under nitrogen flow, dissolve in a 500 mL four-necked flask by adding 40.91 g (0.189 mol) of nuclear hydrogenated trimellitic acid, 40.6 mg (0.56 mmol) of N, N′-dimethylformamide, and 200 ml of toluene. I let you. To this was added 64.35 g (0.541 mol) of thionyl chloride, and the mixture was reacted at 60 ° C. for 4.5 hours in a nitrogen atmosphere. After the reaction, excess thionyl chloride and toluene were distilled off under reduced pressure, and the contents were concentrated to about 100 g. To this solution was added 300 ml of hexane to precipitate a solid, which was filtered and then vacuum dried at room temperature for 5 hours to obtain 32.9 g (yield 82.2%) of nuclear hydrogenated trimellitic anhydride chloride.
Next, under a nitrogen flow, 13.81 g (125 mmol) of hydroquinone and 20.24 g (256 mmol) of pyridine were dissolved in 160 ml of tetrahydrofuran in a 500 mL four-necked flask and cooled to 0 ° C. in an ice bath. A solution obtained by dissolving 55.43 g (256 mmol) of nuclear hydrogenated trimellitic anhydride chloride in 110 mL of tetrahydrofuran was added dropwise thereto. After completion of the dropwise addition, the mixture was returned to room temperature and reacted for 15 hours. After the reaction, the precipitated white solid was separated by filtration and washed 4 times with 40 ml of water to remove the hydrochloride. This was vacuum-dried at 120 ° C. to obtain 47.8 g (yield 81.0%) of a crude product of hydroquinone hydrogenated trimellitic acid diester dianhydride (structure is shown below). The nitrogen content of this product was 870 ppm.

  This crude hydroquinone hydrogenated trimellitic acid diester dianhydride was polymerized with 4,4′-diaminodiphenyl ether (hereinafter abbreviated as ODA) in N, N-dimethylacetamide (hereinafter abbreviated as DMAc) to form a polyesterimide. An attempt was made to produce a film, but the degree of polymerization did not increase and a film could not be obtained.

[Example 1] Purification of hydroquinone hydrogenated trimellitic diester dianhydride crude (recrystallization with acetic anhydride / acetic acid) and synthesis of polyimide Hydroquinone hydrogenation obtained in Comparative Example 1 in a 1 L three-necked flask 200 ml of acetic anhydride and 300 ml of acetic acid were added to 23.9 g of a crude product of trimellitic diester dianhydride and dissolved at 140 ° C. This was cooled at room temperature, and the precipitated solid was filtered off and then vacuum dried at 150 ° C. to obtain 13.7 g of the desired product. The nitrogen content of this purified hydroquinone hydrogenated trimellitic acid diester dianhydride was 6 ppm.

To a 50 mL three-necked flask, 0.801 g (4.00 mmol) of ODA and 10.75 g of DMAc were added and stirred at room temperature to dissolve. To this was added 1.88 g (4.00 mmol) of the purified hydroquinone hydrogenated trimellitic acid diester dianhydride, and the mixture was stirred for 1 hour. Next, after dilution with 6.39 g of DMAc, the mixture was continuously stirred for 16 hours.
The intrinsic viscosity of the obtained alicyclic polyesterimide precursor was 1.99 dL / g, which was a very high polymer.
Thereafter, 13.68 g of DMAc was added for dilution, and 5 ml of acetic anhydride and 2.5 ml of pyridine were added and reacted at 100 ° C. for 4 hours. After cooling, the content was poured into 200 ml of methanol, and the precipitate was separated by filtration, washed with methanol and then vacuum dried at 100 ° C. for 5 hours to obtain 2.18 g of polyimide powder. The structure of the obtained polyimide is shown below.

  The synthesized polyesterimide powder was dissolved in DMAc to a solid concentration of 20% by weight and applied on a glass plate. The glass plate was heated at 80 ° C. for 1 hour and at 200 ° C. for 1 hour to obtain a good polyesterimide film. This polyesterimide film had a glass transition point of 220 ° C. and a linear thermal expansion coefficient of 86 ppm / K.

[Example 2] Purification of hydroquinone hydrogenated trimellitic acid diester dianhydride crude product (recrystallization with acetic anhydride / γ-butyrolactone)
In a 50 ml three-necked flask, 2 ml of acetic anhydride and 20 ml of γ-butyrolactone were added to 5.00 g of the hydroquinone hydrogenated trimellitic acid diester dianhydride obtained in Comparative Example 1, and dissolved at 115 ° C. This was cooled at room temperature, 100 ml of toluene was added, the precipitated solid was filtered off, and then vacuum dried at 150 ° C. to obtain 3.80 g of the desired product. The nitrogen content of this purified hydroquinone hydrogenated trimellitic acid diester dianhydride was 19 ppm.

[Comparative Example 2] Synthesis of 9,9-bis (4-hydroxyphenyl) fluorene hydrogenated trimellitic diester dianhydride crude substance In a 500 mL four-necked flask under nitrogen flow, 9,9-bis (4 -Hydroxyphenyl) fluorene 20.2 g (57.7 mmol) and pyridine 16.16 g (204 mmol) were dissolved in tetrahydrofuran 160 ml. A solution obtained by dissolving 27.52 g (127 mmol) of the nuclear hydrogenated trimellitic anhydride chloride obtained in Comparative Example 1 in 80 mL of tetrahydrofuran was added dropwise thereto. After completion of the dropping, the reaction was further continued at room temperature for 7 hours. After the reaction, the precipitated hydrochloride was filtered off and the filtrate was concentrated. The obtained white solid was vacuum-dried at 120 ° C. to obtain 52.33 g of a crude product of 9,9-bis (4-hydroxyphenyl) fluorene hydrogenated trimellitic acid diester dianhydride (structure is as follows). The nitrogen content of this product was 0.68% by weight.

  Using this 9,9-bis (4-hydroxyphenyl) fluorene hydrogenated trimellitic acid diester dianhydride crude material, an attempt was made to prepare a polyesterimide film by polymerizing with ODA in DMAc. The film could not be obtained.

[Example 3] Purification of crude 9,9-bis (4-hydroxyphenyl) fluorene hydrogenated trimellitic acid diester dianhydride (acetic anhydride / toluene recrystallization)
To the 9,9-bis (4-hydroxyphenyl) fluorene-hydrogenated trimellitic acid diester dianhydride crude product obtained in Comparative Example 2, 500 ml of a 5 wt% aqueous acetic acid solution was added and reacted at 50 ° C for 1 hour. Hydrolysis was performed. The precipitated white solid of tetracarboxylic acid was filtered off, dissolved in 340 ml of ethyl acetate, washed three times with 100 ml of water, and dried over anhydrous magnesium sulfate. After the dehydrating agent was filtered off, the filtrate was concentrated, and 28 ml of acetic anhydride and 280 ml of toluene were added to the resulting white solid and heated at 95 ° C., after which the solid dissolved once and then precipitated again. This was cooled, filtered, and vacuum dried at 150 ° C. for 9 hours to obtain 31.38 g of purified 9,9-bis (4-hydroxyphenyl) fluorene hydrogenated trimellitic acid diester dianhydride. The nitrogen content of this product was 9 ppm.

To a 50 mL three-necked flask, ODA 0.300 g (1.50 mmol) and DMAc 3.06 g were added and stirred at room temperature to dissolve. To this, 1.07 g (1.51 mmol) of 9,9-bis (4-hydroxyphenyl) fluorene hydrogenated trimellitic acid diester dianhydride purified by the above method was added and stirred as it was for 30 minutes. Next, the solution was diluted with 4.44 g of DMAc, and then stirred for 2 hours.
The intrinsic viscosity of this alicyclic polyesterimide precursor was 1.06 dL / g.
Thereafter, 8 ml of DMAc was added for dilution, and 2.5 ml of acetic anhydride and 1.25 ml of pyridine were added and reacted at room temperature for 16 hours. The contents were poured into 200 ml of water, and the precipitate was separated by filtration, washed with water and methanol, and then vacuum dried at 100 ° C. for 6.5 hours to obtain 1.00 g of polyesterimide powder. The structure of the obtained polyesterimide is shown below.

  The synthesized polyesterimide powder was dissolved in DMAc to a solid concentration of 20% by weight and applied on a glass plate. The glass plate was heated at 80 ° C. for 1 hour and at 200 ° C. for 1 hour to obtain a good polyesterimide film. The glass transition point of the polyesterimide film was 269 ° C.

[Reference Example 1] Reduction effect of linear thermal expansion coefficient by adding inorganic filler to polyesterimide film (Preparation method of zirconium oxide)
500 ml of benzyl alcohol was placed in a 1 L 3-neck flask and bubbled with nitrogen for 30 minutes. With nitrogen bubbling, 116.7 g (0.25 mol) of a 70 wt.% Zirconium propoxide / 1-propanol solution was added and stirred for 30 minutes. To this, 100.3 g (0.375 mol) of oleylamine was added to add 30 more. Stir for minutes. The prepared solution was sealed in a stainless steel sealed container having a Teflon inner cylinder and heated at 200 ° C. for 24 hours in an oven. A large excess of ethanol was added to the resulting milky white slurry-like reaction solution to form a zirconium oxide precipitate, which was then centrifuged to collect the precipitate. The precipitate was washed three times with ethanol to obtain a wet white precipitate. The crystal particle diameter of the zirconium oxide was 3 nm (average particle diameter).

(Film production example 1)
48 mg wet zirconium oxide obtained by the above method and 15 mg acetic acid were stirred in 911 mg DMAc at 20 ° C. for 1.5 hours, and then filtered through a filter having a pore diameter of 45 μm to obtain a colorless and transparent dispersion of zirconium oxide. A liquid was obtained. In 508 mg of this solution, 85 mg of the polyesterimide powder synthesized in Example 1 was dissolved, cast onto a glass substrate, dried at 20 ° C. under a nitrogen atmosphere for 30 minutes, and then from 20 ° C. to 15 under a reduced pressure of 0.001 MPa. The temperature was raised to 80 ° C. over a period of 1 hour and treated for 1 hour, and further heated to 200 ° C. over 2 hours and treated for 1 hour. After cooling, the film was peeled off from the glass substrate to obtain a colorless and transparent film having a thickness of 20 μm. The linear expansion coefficient at 100 to 150 ° C. of this film was 74 ppm / K, which was lower than the value of 86 ppm / K of the polyesterimide film obtained in Example 1.

(Film Production Example 2)
In a glass container, 28 mg of wet zirconium oxide obtained by the above method, 94 mg of the polyesterimide powder synthesized in Example 1, and 539 mg of N, N-dimethylacetamide were added. After the polyesterimide and the solvent became uniform, the zirconium oxide was well dispersed in the varnish by stirring at 20 ° C. for 16 hours to obtain a cloudy varnish. This was cast on a glass substrate, heated from 20 ° C. to 80 ° C. over 15 minutes in a nitrogen atmosphere, treated for 1 hour, and further heated to 200 ° C. over 2 hours and treated for 1 hour. After cooling, the film was peeled off from the glass substrate to obtain a white turbid polyesterimide film having a film thickness of 25 μm.

Claims (7)

The ester group-containing alicyclic tetracarboxylic acid dianhydride represented by the following general formula (1) whose purity is increased from the ester group-containing alicyclic tetracarboxylic acids represented by the following general formulas (1) to (3): In the method for producing a product, the ester group is purified by using a mixed solvent containing a carboxylic acid anhydride having at least 10 carbon atoms and an inert organic solvent mixed with the carboxylic acid anhydride at an indefinite ratio. A method for producing an alicyclic tetracarboxylic dianhydride.

(In formulas (1) to (3), A represents a divalent group.)   The method for producing an ester group-containing alicyclic tetracarboxylic dianhydride according to claim 1, wherein the carboxylic anhydride is acetic anhydride.   The ester group-containing alicyclic ring according to claim 1 or 2, wherein the inert organic solvent is one or more selected from the group consisting of carboxylic acids, cyclic esters, amides, and hydrocarbons. A process for producing a formula tetracarboxylic dianhydride.   4. The inert organic solvent is one or more selected from the group consisting of acetic acid, γ-butyrolactone, N-methylpyrrolidone, N, N-dimethylacetamide, and toluene. The manufacturing method of ester group containing alicyclic tetracarboxylic dianhydride of description.   The mixing ratio of the carboxylic acid anhydride and the inert organic solvent is 0.1 to 30 parts by weight of the inert organic solvent with respect to 1 part by weight of the carboxylic acid anhydride. A process for producing an ester group-containing alicyclic tetracarboxylic dianhydride according to claim 1. An ester group-containing alicyclic tetracarboxylic dianhydride represented by the following general formula (1), wherein the nitrogen content is 800 ppm or less. Anhydride.

(In formulas (1) to (3), A represents a divalent group.)   A method for producing an alicyclic polyesterimide, wherein the ester group-containing alicyclic tetracarboxylic dianhydride according to claim 6 is reacted with a diamine and then imidized.