Tetracarboxylic dianhydride, carbonyl compound, polyimide precursor resin, and polyimide

Abstract

To provide a tetracarboxylic acid dianhydride that can be used as a base monomer for producing a polyimide having a higher level of heat resistance, and also allows for improved polymerization reactivity when used as the base monomer for producing the polyimide.SOLUTION: A tetracarboxylic acid dianhydride has: an acid dianhydride (A) having an exo / exo conformation represented by a specific general formula and / or at least one acid dianhydride (B) selected from the group consisting of a compound having an endo / exo conformation represented by specific another general formula and an enantiomer thereof, which is a compound having an exo / endo conformation. Relative to the total amount of the acid dianhydrides (A) and (B), the content of the acid dianhydride (A) is 30-100 mol% in terms of molar ratio.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to tetracarboxylic dianhydrides, carbonyl compounds, polyimide precursor resins, and polyimides.

Background Art

[0002] Generally, tetracarboxylic dianhydrides are useful as raw materials for producing polyimide resins, epoxy curing agents, and the like. Among such tetracarboxylic dianhydrides, aromatic tetracarboxylic dianhydrides such as pyromellitic dianhydride have been mainly used as raw materials for polyimide resins used in the field of electronic devices and the like. And as polyimides obtained using such aromatic tetracarboxylic dianhydrides, for example, polyimide (trade name "Kapton") sold by Toray DuPont has been widely known as an essential material for advanced industries such as space and aviation applications. However, although polyimides obtained using conventional aromatic tetracarboxylic dianhydrides have excellent physical properties in terms of heat resistance, they are colored (yellow to brown) and are not suitable for use in optical applications where transparency is required.

[0003] Under such circumstances, in order to produce polyimide that can be used for optical applications and the like, from the perspective of light transmittance, research on various aliphatic tetracarboxylic dianhydrides has been carried out. Such aliphatic tetracarboxylic dianhydrides have not always been sufficient in terms of heat resistance when used to produce polyimide in the past. Therefore, in recent years, research on aliphatic tetracarboxylic dianhydrides that can produce polyimide with a high level of heat resistance has been advanced. As such an aliphatic tetracarboxylic dianhydride, for example, in International Publication No. 2018 / 147373 (Patent Document 1), a compound composed of stereoisomers having an end / exo-type three-dimensional structure of 5,5'-bi-2-norbornene-5,5',6,6'-tetracarboxylic acid-5,5',6,6'-dianhydride (hereinafter sometimes referred to as "BNBDA") and its enantiomers (stereoisomers having an exo / endo-type three-dimensional structure), and stereoisomers having an end / end-type three-dimensional structure, wherein the content ratio of the stereoisomers having an end / end-type three-dimensional structure is within a specific range with respect to the total amount of these stereoisomers, and other tetracarboxylic dianhydrides are disclosed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The tetracarboxylic dianhydride as described in Patent Document 1 above is an aliphatic tetracarboxylic dianhydride, but it was capable of producing polyimide having a high level of heat resistance. In the field of such aliphatic tetracarboxylic dianhydrides, the emergence of tetracarboxylic dianhydrides that can produce polyimide capable of exhibiting an even higher level of heat resistance according to applications and the like is desired.

[0006] The present invention has been made in view of the problems of the above prior art, and can be used as a raw material monomer for producing a polyimide having a higher level of heat resistance. Moreover, when used as a raw material monomer for producing a polyimide, it is also possible to further improve the polymerization reactivity. The present invention aims to provide a tetracarboxylic dianhydride, a carbonyl compound that can be used to efficiently produce the tetracarboxylic dianhydride, a polyimide that can have a higher level of heat resistance, and a polyimide precursor resin that can be suitably used for producing the polyimide.

Means for Solving the Problems

[0007] As a result of intensive studies to achieve the above object, the present inventors have found that an acid dianhydride (A) having an exo / exo-type steric structure represented by the following general formula (1), and / or at least one acid dianhydride (B) selected from the group consisting of a compound having an endo / exo-type steric structure represented by the following general formula (2) and a compound having an exo / endo-type steric structure which is a mirror image thereof. When a polyimide is produced using the tetracarboxylic dianhydride in which the content of the acid dianhydride (A) with respect to the total amount of the acid dianhydrides (A) and (B) is 30 to 100 mol% in terms of molar ratio, it is possible not only to have a higher level of heat resistance compared to conventional polyimides (for example, the polyimide described in Patent Document 1 above), but also to further improve the polymerization reactivity during the production of the polyimide. Based on this finding, the present invention has been completed.

[0008] That is, the present invention provides the following aspects.

[0009] [1] The following general formula (1):

[0010]

Chemical Formula

[0011] [In formula (1), R 1 each independently represents one selected from the group consisting of a hydrogen atom and a methyl group and the like.] shown R 2 and R 3 each independently represents one selected from the group consisting of a hydrogen atom and a methyl group and the like.] An acid dianhydride (A) having an exo / exo-type steric structure represented by a tetracarboxylic dianhydride composed of, or the acid dianhydride (A) and the following general formula (2):

[0012]

Chemical formula

[0013] [In formula (2), R 1 , R 2 and R 3 are respectively synonymous with R 1 , R 2 and R 3 in the above formula (1).] At least one acid dianhydride (B) selected from the group consisting of a compound having an endo / exo-type steric structure represented by and an enantiomer thereof having an exo / endo-type steric structure a tetracarboxylic dianhydride composed of and a tetracarboxylic dianhydride in which the content of the acid dianhydride (A) relative to the total amount of the acid dianhydrides (A) and (B) is 30 to 100 mol% in terms of molar ratio.

[0014] [2] The following general formula (3):

[0015]

Chemical formula

[0016] [In formula (3), R 1 each independently represents one selected from the group consisting of a hydrogen atom and a methyl group and the like.] shown R 2 and R 3 each independently represents a hydrogen atomand a methyl group represents one selected from the group consisting of R 4 each independently represents one selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms, and an aralkyl group having 7 to 20 carbon atoms.] a carbonyl compound (A) having an exo / exo type steric structure represented by a carbonyl compound composed of, or the carbonyl compound (A) and the following general formula (4):

[0017] [Chemical formula]

[0018] [In formula (4), R 1 , R 2 , R 3 and R 4 are respectively synonymous with R 1 , R 2 , R 3 and R 4 in the above formula (3).] at least one carbonyl compound (B) selected from the group consisting of a compound having an endo / exo type steric structure represented by and an enantiomer thereof having an exo / endo type steric structure a carbonyl compound composed of and a carbonyl compound in which the content of the carbonyl compound (A) relative to the total amount of the carbonyl compounds (A) and (B) is 30 to 100 mol% in molar ratio.

[0019] [3] The following general formula (5):

[0020] [Chemical formula]

[0021] [In formula (5), R 1 each independently represents one selected from the group consisting of a hydrogen atom and a methyl group selected from the group consisting of shown R 2 and R3 each independently represents one selected from the group consisting of a hydrogen atom and a methyl group and the like, R 5 represents an arylene group having 6 to 50 carbon atoms.] The repeating unit (A) having an exo / exo type steric structure represented by a polyimide containing, or the repeating unit (A) and The following general formula (6):

[0022] [Chemical formula]

[0023] [In formula (6), R 1 , R 2 , R 3 and R 5 are each the same as R 1 , R 2 , R 3 and R 5 in the above formula (5).] contains at least one repeating unit (B) selected from the group consisting of a structural unit having an endo / exo type steric structure represented by and a structural unit having an exo / endo type steric structure which is a mirror image thereof a polyimide which does and a polyimide in which the content of the repeating unit (A) relative to the total amount of the repeating units (A) and (B) is 30 to 100 mol% in terms of molar ratio.

[0024] [4] The following general formula (7):

[0025] [Chemical formula]

[0026] [In formula (7), R 1 each independently represents one selected from the group consisting of a hydrogen atom and a methyl group and the like, R 2 and R 3 each independently represents one selected from the group consisting of a hydrogen atom and a methyl group and the like, R 5represents an arylene group having 6 to 50 carbon atoms, Y 1 each independently represents one selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, and an alkylsilyl group having 3 to 9 carbon atoms, One of the bonds represented by *1 and the bond represented by *2 is bonded to the carbon atom a forming the norbornane ring, and the other of the bond represented by *1 and the bond represented by *2 is bonded to the carbon atom b forming the norbornane ring. One of the bonds represented by *3 and the bond represented by *4 is bonded to the carbon atom c forming the norbornane ring, and the other of the bond represented by *3 and the bond represented by *4 is bonded to the carbon atom d forming the norbornane ring.] a repeating unit (A') having an exo / exo type steric structure represented by a polyimide precursor resin containing, or the repeating unit (A') and The following general formula (8):

[0027]

Chemical formula

[0028] [In formula (8), R 1 , R 2 , R 3 , R 5 , Y 1 , a to d and *1 to *4 are respectively the same as R 1 , R 2 , R 3 , R 5 , Y 1 , a to d and *1 to *4 in formula (7).] contains at least one repeating unit (B') selected from the group consisting of a structural unit having an endo / exo type steric structure represented by and its enantiomer having an exo / endo type steric structure a polyimide precursor resin which does and a polyimide precursor resin in which the content of the repeating unit (A') relative to the total amount of the repeating units (A') and (B') is 30 to 100 mol% in molar ratio.

[0029] Regarding the expression of the form of stereoisomers, etc. in the present application, when focusing on one bicyclic ring (norbornane ring), the form is expressed depending on whether the other bicyclic ring (norbornane ring) is bonded at the exo position or the endo position. For example, the above acid dianhydride (A) is expressed as "exo / exo form" because the other bicyclic ring is bonded to the exo position of one bicyclic ring whether viewed from the left or the right.

Advantages of the Invention

[0030] According to the present invention, it is possible to use it as a raw material monomer for producing a polyimide having a higher level of heat resistance, and moreover, it is also possible to further improve the polymerization reactivity when used as a raw material monomer for producing a polyimide. Provided are a tetracarboxylic dianhydride, a carbonyl compound that can be used to efficiently produce the tetracarboxylic dianhydride, a polyimide that can have a higher level of heat resistance, and a polyimide precursor resin that can be suitably used for producing the polyimide.

Embodiments for Carrying Out the Invention

[0031] Hereinafter, the present invention will be described in detail according to its preferred embodiments. In this specification, unless otherwise specified, the notation "X to Y" for numerical values X and Y means "X or more and Y or less". When a unit is attached only to the numerical value Y in such notation, the unit is also applied to the numerical value X.

[0032] [Tetracarboxylic Dianhydride] The tetracarboxylic dianhydride of the present invention comprises at least one acid dianhydride (B) selected from the group consisting of an acid dianhydride (A) having an exo / exo-type steric structure represented by the above general formula (1) and / or a compound having an endo / exo-type steric structure represented by the above general formula (2) and a compound having an exo / endo-type steric structure which is an enantiomer thereof, and the content of the acid dianhydride (A) relative to the total amount of the acid dianhydrides (A) and (B) is 30 to 100 mol% in terms of molar ratio.

[0033] Note that the following formula (9):

[0034]

Chemical formula

[0035] [In formula (9), R 1 , R 2 and R 3 are synonymous with R 1 , R 2 and R 3 in the above formula (1), respectively.] The tetracarboxylic dianhydride represented by the formula includes, as stereoisomers, a stereoisomer A (acid dianhydride (A)) having an exo / exo type three-dimensional structure represented by the above general formula (1), a compound having an endo / exo type three-dimensional structure represented by the above general formula (2), and a stereoisomer B (acid dianhydride (B)) composed of a compound having an exo / endo type three-dimensional structure which is a mirror image thereof. In addition, there is a stereoisomer C having an endo / endo type three-dimensional structure. The tetracarboxylic dianhydride of the present invention is a compound (acid dianhydride) composed of stereoisomer A and / or stereoisomer B among such stereoisomers A to C, and the amount of stereoisomer A relative to the total amount of stereoisomer A and stereoisomer B is 30 to 100 mol% in terms of molar ratio. Regarding the above-mentioned "stereoisomer B (acid dianhydride (B))", a stereoisomer having an endo / exo type structure represented by the above general formula (2) (hereinafter, sometimes simply referred to as "stereoisomer B1") and / or a stereoisomer having an exo / endo type structure which is a mirror image thereof (hereinafter, sometimes simply referred to as "stereoisomer B2") cannot be spectroscopically distinguished from each other. Therefore, in the above description of stereoisomers, the endo / exo type structure and the exo / endo type structure are evaluated as having equivalent isomeric structures, and the stereoisomer composed of stereoisomer B1 and / or stereoisomer B2 is simply expressed as "stereoisomer B". And in the present invention, the "compound having an endo / exo type three-dimensional structure" which cannot be spectroscopically distinguished and its mirror image (enantiomer), the "compound having an exo / endo type three-dimensional structure", are referred to as "acid dianhydride (B)".

[0036] R in the above general formula (1) 1 each independently represents one selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a hydroxyl group, and a nitro group, or two Rs 1 bonded to the same carbon atom in the above general formula (1) 1 may together form a methylidene group. R in the above general formula (1) 1The alkyl group that can be selected as such is an alkyl group having 1 to 10 carbon atoms. When the number of carbon atoms exceeds 10, the heat resistance of the resulting polyimide decreases when used as a monomer of the polyimide. Also, such R 1 Regarding the number of carbon atoms of the alkyl group that can be selected as such, from the viewpoint of obtaining higher heat resistance when producing the polyimide, it is preferably 1 to 6, more preferably 1 to 5, still more preferably 1 to 4, and particularly preferably 1 to 3. Also, such R 1 The alkyl group that can be selected as such may be linear or branched.

[0037] Among the plurality of R's in the general formula (1) above 1 Two R's bonded to the same carbon atom 1 may combine together to form a methylidene group (=CH2). That is, two R's bonded to the same carbon atom in the general formula (1) above 1 may combine together and be bonded as a methylidene group (methylene group) to the carbon atom (among the carbon atoms forming the norbornane ring structure, the carbon atom to which two R's 1 are bonded) by a double bond.

[0038] Among the plurality of R's in the general formula (1) above 1 As such, from the viewpoints of obtaining higher heat resistance when producing the polyimide, easy availability of raw materials, easier purification, etc., each independently, it is more preferably a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, or an isopropyl group, and particularly preferably a hydrogen atom or a methyl group. Also, the plurality of R's in such formula (1) 1 may be the same or different from each other, but from the viewpoint of ease of purification, etc., it is preferably the same.

[0039] R in the general formula (1) above 2 and R 3is independently selected from the group consisting of a hydrogen atom and an alkyl group having 1 to 10 carbon atoms. Such R 2 and R 3 When the number of carbon atoms of the alkyl group that can be selected as exceeds 10, the heat resistance of the resulting polyimide decreases when used as a monomer of the polyimide. Also, such R 2 and R 3 As the alkyl group that can be selected as, from the viewpoint of obtaining higher heat resistance when producing polyimide, it is preferably 1 to 6, more preferably 1 to 5, still more preferably 1 to 4, and particularly preferably 1 to 3. Also, such R 2 and R 3 The alkyl group that can be selected as may be linear or branched.

[0040] Also, R in the general formula (1) above 2 and R 3 From the viewpoints of obtaining higher heat resistance when producing polyimide, easy availability of raw materials, easier purification, etc., each is more preferably independently a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, or an isopropyl group, and particularly preferably a hydrogen atom or a methyl group. Also, R in such formula (1) 2 and R 3 may be the same or different from each other, but from the viewpoint of ease of purification, etc., it is preferably the same.

[0041] Also, a plurality of R in the general formula (1) above 1 、R 2 and R 3 are all particularly preferably hydrogen atoms. Thus, in the compound represented by the general formula (1), when the substituents represented by R 1 、R 2 and R 3 are all hydrogen atoms, the yield of the compound tends to improve. Also, when producing a polyimide using the compound as a monomer, higher heat resistance tends to be obtained.

[0042] In the general formula (2) above, R 1 , R 2 and R 3 are respectively synonymous with R 1 , R 2 and R 3 in the general formula (1) above, and the preferred ones are the same.

[0043] The acid dianhydride (B) may contain a compound having an end / exo-type steric structure and a compound having an exo / end-type steric structure. However, as the acid dianhydride (B), it may contain only one of the compounds, or it may contain both of those compounds.

[0044] The tetracarboxylic dianhydride of the present invention consists of the above acid dianhydride (A) and / or the above acid dianhydride (B), and the content of the acid dianhydride (A) relative to the total amount of the acid dianhydrides (A) and (B) is 30 to 100 mol%. By setting the content of the acid dianhydride (A) to be equal to or higher than the lower limit, when polyimide is produced using this, not only can a high level of heat resistance be exhibited, but also when used as a monomer in the polymerization of polyimide, the polymerization reactivity can be further improved.

[0045] Furthermore, the content of the acid dianhydride (A) relative to the total amount of the acid dianhydrides (A) and (B) is more preferably 40 to 100 mol%, still more preferably 60 to 100 mol%, particularly preferably 80 to 100 mol%, and most preferably 90 to 100 mol%. When the content of the acid dianhydride (A) is within the preferred range, when polyimide is produced using this, the heat resistance tends to be further improved.

[0046] A method for producing such a tetracarboxylic dianhydride of the present invention will be described later.

[0047] [Carbonyl compound] The carbonyl compound of the present invention comprises at least one carbonyl compound (A) having an exo / exo-type steric structure represented by the above general formula (3) and / or at least one carbonyl compound (B) selected from the group consisting of a compound having an endo / exo-type steric structure represented by the above general formula (4) and a compound having an exo / endo-type steric structure which is an enantiomer thereof, and the content of the carbonyl compound (A) relative to the total amount of the carbonyl compounds (A) and (B) is 30 to 100 mol% in terms of molar ratio. Regarding the carbonyl compound, the compound having an endo / exo-type steric structure and the compound having an exo / endo-type steric structure which is an enantiomer (enantiomer) thereof cannot be spectroscopically distinguished from each other, and thus these are referred to as "carbonyl compound (B)".

[0048] Such R in the general formula (3) 1 , R 2 and R 3 are the same as R 1 , R 2 and R 3 in the above general formula (1), respectively, and the preferred ones are also the same as R 1 , R 2 and R 3 in the above general formula (1). Note that a plurality of R 1 in such general formula (3) may be the same or different from each other, but from the viewpoint of ease of purification, etc., it is preferably the same. Further, R 2 and R 3 in the general formula (3) may also be the same or different from each other, but from the viewpoint of ease of purification, etc., it is preferably the same.

[0049] A plurality of R 1 , R 2 and R 3 in the above general formula (3) are all particularly preferably hydrogen atoms. Thus, in the compound represented by the general formula (3), R 1 , R 2 and R 3When all of the substituents represented by [the formula] are hydrogen atoms, the yield of the compound tends to improve. Further, when an acid dianhydride is formed from the compound and a polyimide is produced using the obtained acid dianhydride as a monomer, a higher degree of heat resistance tends to be obtained.

[0050] Further, R in the general formula (3) 4 The alkyl group that can be selected as [R] is an alkyl group having 1 to 10 carbon atoms. When the number of carbon atoms of such an alkyl group exceeds 10, purification becomes difficult. Further, for the number of carbon atoms of such a plurality of alkyl groups that can be selected as [R], from the viewpoint of easier purification, it is more preferably 1 to 5, and even more preferably 1 to 3. Further, the alkyl group that can be selected as such a plurality of [R] may be linear or branched. 4 For the number of carbon atoms of such a plurality of alkyl groups that can be selected as [R], from the viewpoint of easier purification, it is more preferably 1 to 5, and even more preferably 1 to 3. Further, the alkyl group that can be selected as such a plurality of [R] may be linear or branched. 4 The alkyl group that can be selected as [R] may be linear or branched.

[0051] Further, R in the general formula (3) 4 The cycloalkyl group that can be selected as [R] is a cycloalkyl group having 3 to 10 carbon atoms. When the number of carbon atoms of such a cycloalkyl group exceeds 10, purification becomes difficult. Further, for the number of carbon atoms of such a plurality of cycloalkyl groups that can be selected as [R], from the viewpoint of easier purification, it is more preferably 3 to 8, and even more preferably 5 to 6. 4 For the number of carbon atoms of such a plurality of cycloalkyl groups that can be selected as [R], from the viewpoint of easier purification, it is more preferably 3 to 8, and even more preferably 5 to 6.

[0052] Furthermore, R in the general formula (3) 4 The alkenyl group that can be selected as [R] is an alkenyl group having 2 to 10 carbon atoms. When the number of carbon atoms of such an alkenyl group exceeds 10, purification becomes difficult. Further, for the number of carbon atoms of such a plurality of alkenyl groups that can be selected as [R], from the viewpoint of easier purification, it is more preferably 2 to 5, and even more preferably 2 to 3. 4 For the number of carbon atoms of such a plurality of alkenyl groups that can be selected as [R], from the viewpoint of easier purification, it is more preferably 2 to 5, and even more preferably 2 to 3.

[0053] Further, R in the general formula (3) 4The aryl group that can be selected as such is an aryl group having 6 to 20 carbon atoms. When the number of carbon atoms of such an aryl group exceeds 20, purification becomes difficult. Also, for such a plurality of Rs 4 From the viewpoint of easier purification, the number of carbon atoms of the aryl group that can be selected as such is more preferably 6 to 10, and even more preferably 6 to 8.

[0054] Also, R in the general formula (3) 4 The aralkyl group that can be selected as such is an aralkyl group having 7 to 20 carbon atoms. When the number of carbon atoms of such an aralkyl group exceeds 20, purification becomes difficult. Also, for such a plurality of Rs 4 From the viewpoint of easier purification, the number of carbon atoms of the aralkyl group that can be selected as such is more preferably 7 to 10, and even more preferably 7 to 9.

[0055] Furthermore, for a plurality of Rs in the general formula (3) 4 From the viewpoint of easier purification, each is independently preferably a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, sec-butyl, t-butyl, cyclohexyl group, allyl group, phenyl group or benzyl group, more preferably a methyl group, an ethyl group, an n-propyl group, even more preferably a methyl group, an ethyl group, and particularly preferably a methyl group. Note that a plurality of Rs in the general formula (3) 4 may be the same or different from each other, but from the viewpoint of synthesis, it is more preferably the same.

[0056] Also, R in the general formula (4) 1 , R 2 , R 3 and R 4 are respectively synonymous with R in the above general formula (3) 1 , R 2 , R 3 and R 4 and the preferred ones are the same.

[0057] The carbonyl compound (B) may contain a compound having an endo / exo-type steric structure and a compound having an exo / endo-type steric structure. Such a carbonyl compound (B) may contain only one of the compounds, or may contain both of the compounds.

[0058] Further, the tetracarboxylic dianhydride of the present invention is composed of the above carbonyl compound (A) and / or the above carbonyl compound (B), and the content of the carbonyl compound (A) relative to the total amount of the carbonyl compounds (A) and (B) is 30 to 100 mol% in terms of molar ratio. By setting the content of such a carbonyl compound (A) to be not less than the above lower limit, when an acid anhydride is produced using this and a polyimide is produced using it as a monomer, not only can a higher level of heat resistance be exhibited, but also the polymerization reactivity of the monomer can be further improved.

[0059] Furthermore, the content of the carbonyl compound (A) relative to the total amount of such carbonyl compounds (A) and (B) is more preferably 40 to 100 mol%, still more preferably 60 to 100 mol%, particularly preferably 80 to 100 mol%, and most preferably 90 to 100 mol%. When the content of the carbonyl compound (A) is within the above preferred range, when an acid anhydride is produced using this and a polyimide is produced using it as a monomer, the heat resistance of the polyimide can be further improved.

[0060] (Method for producing a carbonyl compound) A method that can be preferably adopted as a method for producing the carbonyl compound of the present invention will be described. The method for producing such a carbonyl compound is not particularly limited. For example, in the presence of a palladium catalyst and an oxidizing agent, the following general formula (10):

[0061]

Chemical formula

[0062] [wherein, R 1 and R 2 are respectively the same as R 1 and R 2 in the above formula (3) (and the preferred ones are also the same).] A compound represented by (a norbornene compound having an exo - type steric structure in which a vinyl group is bonded to the exo - position: hereinafter, sometimes simply referred to as "raw material compound (I)") is reacted with an alcohol and carbon monoxide to obtain the following general formula (11):

[0063] [Chemical formula]

[0064] [wherein, R 1 , R 2 and R 4 are respectively the same as R 1 , R 2 and R 4 in the above formula (3) (and the preferred ones are also the same).] A step (1) of obtaining a compound represented by (since such a compound is used as a raw material in the following step (2), hereinafter, sometimes simply referred to as "raw material compound (II)"), and A mixture of the raw material compound (II) and dicyclopentadiene which may have a substituent is heated to a temperature of 150 °C or higher and reacted to obtain the following formula (12):

[0065] [Chemical formula]

[0066] [wherein, R 1 , R 2 , R 3 and R 4 are respectively the same as R 1 , R 2 , R 3 and R 4is synonymous with (and its preferred ones are also synonymous with).] a compound having an exo / exo-type steric structure represented by, and the following formula (13):

[0067] [Chemical formula]

[0068] [wherein, R 1 , R 2 , R 3 and R 4 are respectively R 1 , R 2 , R 3 and R 4 in the above formula (3) and are synonymous with (and their preferred ones are also synonymous with).] a step (2) of obtaining a carbonyl compound precursor comprising a compound having an endo / exo-type steric structure represented by and / or a compound having an exo / endo-type steric structure which is a mirror image thereof, in the presence of a palladium catalyst and an oxidizing agent, reacting the carbonyl compound precursor with an alcohol and carbon monoxide to obtain a carbonyl compound comprising the above carbonyl compound (A) and the above carbonyl compound (B), and then, if necessary, adjusting the content of the carbonyl compound (A) to obtain the carbonyl compound of the present invention in step (3), A method including can be employed. Hereinafter, steps (1) to (3) will be described separately.

[0069] 〈Regarding step (1)〉 Step (1) is a step of obtaining the raw material compound (II) by reacting the raw material compound (I) with an alcohol and carbon monoxide.

[0070] The raw material compound (I) used in the step (1) is a norbornene compound having an exo - type steric structure in which a vinyl group is bonded to the exo - position, as represented by the above formula (10). The method for producing such a raw material compound (I) is not particularly limited, and known methods (for example, the method described in "Bull. Chem. Soc. Jpn., vol. 60, p. 1954 - p. 1956 (1987)") can be appropriately adopted. In the above formula (10), R 1 and R 2 are respectively synonymous with R 1 and R 2 in the above formula (3), and the preferred ones are also synonymous.

[0071] The alcohol used in the step (1) is not particularly limited, but from the viewpoint of ease of purification, the following general formula (14): R a OH (14) [In the formula, R a is other than a hydrogen atom among the atoms and groups that can be selected as R 4 in the general formula (11).] is preferably an alcohol represented by. That is, as such an alcohol, it is preferable to use an alkyl alcohol having 1 to 10 carbon atoms, a cycloalkyl alcohol having 3 to 10 carbon atoms, an alkenyl alcohol having 2 to 10 carbon atoms, an aryl alcohol having 6 to 20 carbon atoms, or an aralkyl alcohol having 7 to 20 carbon atoms.

[0072] Specific examples of such alcohols include methanol, ethanol, butanol, allyl alcohol, cyclohexanol, benzyl alcohol, etc. Among them, from the viewpoint that the purification of the obtained compound becomes easier, methanol and ethanol are more preferable, and methanol is particularly preferable. Also, such an alcohol may be used alone or in a mixture of two or more.

[0073] In the present invention, in the presence of a palladium catalyst and an oxidizing agent, the alcohol (preferably R aBy reacting (OH) and carbon monoxide (CO) with the norbornene-based compound represented by the general formula (10), to the carbon of the olefin moiety in the norbornene ring of the norbornene-based compound represented by the general formula (10), respectively, the following general formula (15): -COOR a (15) [In the formula, R a is other than a hydrogen atom among the atoms and groups that can be selected as R 4 in the general formula (11).] An ester group represented by (such an ester group may be the same or different for each introduced position of R 4 ).) can be introduced, and thereby, the compound represented by the general formula (11) (raw material compound (II)) can be obtained. Thus, in the present invention, in the presence of a palladium catalyst and an oxidizing agent, an alcohol (preferably R a OH) and carbon monoxide (CO) are used to introduce an ester group to the carbon of the olefin moiety in the norbornene ring (hereinafter, such a reaction may be simply referred to as "esterification reaction" in some cases).), and it is possible to obtain the raw material compound (II) represented by the general formula (11). In addition, the conditions that can be adopted in such an esterification reaction are not particularly limited, and known conditions employed in the reaction for introducing an ester group to the carbon of the olefin moiety in the norbornene ring can be appropriately adopted (for example, the same conditions as those employed in the esterification method described in International Publication No. 2018 / 147373 can be adopted).

[0074] The palladium catalyst used in such an esterification reaction is not particularly limited, and a known catalyst containing palladium (for example, the catalyst described in International Publication No. 2018 / 147373) can be appropriately used. Examples thereof include inorganic salts of palladium, organic acid salts of palladium, and catalysts in which palladium is supported on a carrier. Such palladium catalysts include, for example, palladium chloride, palladium nitrate, palladium sulfate, palladium acetate, palladium propionate, palladium carbon, palladium alumina, palladium black, and palladium acetate having a nitrite ligand (formula: Pd3(CH3COO)5(NO2)), etc. are mentioned as preferred ones.

[0075] Further, as such a palladium catalyst, from the viewpoint that the generation of by-products can be more sufficiently suppressed and the compound represented by the general formula (11) can be produced with a higher selectivity, a palladium catalyst containing palladium acetate having a nitrite ligand (a catalyst represented by the formula: Pd3(CH3COO)5(NO2)) (hereinafter, sometimes simply referred to as "Pd3(OAc)5(NO2)") is preferably used. The method for producing such palladium acetate having a nitrite ligand (Pd3(OAc)5(NO2)) is not particularly limited, and known methods can be appropriately used. For example, the method described on pages 1989 to 1992 of Dalton Trans (vol. 11) issued on June 7, 2005 (authors: Vladimir I, Bakhmutov, et al.) etc. can be appropriately used.

[0076] In addition, as the oxidizing agent used in the esterification reaction, when Pd in the palladium catalyst is reduced to Pd 2+ in the esterification reaction, the Pd 0 is reduced to Pd 0 and then to Pd 2+Any substance that can be oxidized may be used. Such oxidizing agents are not particularly limited, and examples include copper compounds and iron compounds. Specifically, such oxidizing agents include cupric chloride, cupric nitrate, cupric sulfate, cupric acetate, ferric chloride, ferric nitrate, ferric sulfate, ferric acetate, etc.

[0077] Furthermore, the amount of alcohol used in such an esterification reaction may be any amount that enables the compound represented by the general formula (11) to be obtained, and is not particularly limited. For example, the alcohol may be added in an amount equal to or greater than the theoretically required amount (theoretical amount) to obtain the compound represented by the general formula (11), and the excess alcohol may be used as a solvent as it is.

[0078] In addition, in the esterification reaction, it is sufficient that the required amount of carbon monoxide can be supplied to the reaction system. Therefore, it is not necessary to use a high-purity gas of carbon monoxide, and a mixed gas of a gas (e.g., nitrogen) inert to the esterification reaction and carbon monoxide may be used. The pressure of such carbon monoxide is not particularly limited, but is preferably not less than normal pressure (about 0.1 MPa [1 atm]) and not more than 10 MPa.

[0079] Furthermore, the method for supplying the carbon monoxide to the reaction system is not particularly limited, and a known method can be appropriately adopted. For example, a method of supplying carbon monoxide by bubbling it into a mixed solution containing the alcohol, the compound represented by the general formula (10), and the palladium catalyst, or when using a reaction vessel, a method of supplying carbon monoxide to the reaction system by introducing carbon monoxide into the atmospheric gas in the vessel can be appropriately adopted.

[0080] In the esterification reaction, the amount of the palladium catalyst used is preferably such that the molar amount of palladium in the palladium catalyst is 0.001 to 0.1 times the molar amount (more preferably 0.001 to 0.01 times the molar amount) of the norbornene-based compound represented by the general formula (10). Further, the amount of the oxidizing agent used is preferably 2 to 16 times the molar amount (more preferably 2 to 8 times the molar amount, still more preferably 2 to 6 times the molar amount) of the norbornene-based compound represented by the general formula (10).

[0081] A solvent may be used in the reaction (esterification reaction) of the norbornene-based compound represented by the general formula (10) with an alcohol and carbon monoxide. Such a solvent is not particularly limited, and known solvents that can be used in the esterification reaction can be appropriately used. Examples include hydrocarbon solvents such as n-hexane, cyclohexane, benzene, and toluene. Further, in the esterification reaction, since an acid is by-produced from the oxidizing agent or the like, a base may be added to remove such an acid. As such a base, fatty acid salts such as sodium acetate, sodium propionate, and sodium butyrate are preferable. The amount of such a base used may be appropriately adjusted according to the amount of acid generated or the like.

[0082] The reaction temperature conditions in the esterification reaction are not particularly limited, but are preferably 0°C to 200°C (more preferably 0°C to 100°C, still more preferably about 10 to 60°C, particularly preferably about 20 to 50°C). When such a reaction temperature exceeds the upper limit, the yield tends to decrease. On the other hand, when it is less than the lower limit, the reaction rate tends to decrease. The reaction time of the esterification reaction is not particularly limited, but is preferably about 30 minutes to 24 hours.

[0083] In addition, the atmospheric gas in the esterification reaction is not particularly limited, and a gas that can be used in the esterification reaction can be appropriately used. For example, an inert gas for the esterification reaction (such as nitrogen, argon, etc.), carbon monoxide, or a mixed gas of carbon monoxide and other gases (such as nitrogen, air, oxygen, hydrogen, carbon dioxide, argon, etc.) may be used. From the perspective of not affecting the catalyst and oxidizing agent, carbon monoxide, an inert gas for the esterification reaction, or a mixed gas of carbon monoxide and an inert gas for the esterification reaction is preferable. When adopting the method of introducing carbon monoxide by bubbling as the method of supplying carbon monoxide into the mixed solution, for example, the atmospheric gas may be made of an inert gas for the esterification reaction before the reaction, and the reaction may be started by the above-mentioned bubbling, and as a result, the reaction may proceed with the atmospheric gas becoming a mixed gas of carbon monoxide and an inert gas for the esterification reaction.

[0084] Furthermore, the pressure conditions in the esterification reaction (the pressure conditions of the atmospheric gas: when the reaction proceeds in the reaction vessel, it is the pressure conditions of the gas in the vessel) are not particularly limited, but it is preferably 0.05 MPa to 15 MPa, more preferably normal pressure (0.1 MPa [1 atm]) to 15 MPa, still more preferably 0.1 MPa to 10 MPa, and particularly preferably 0.11 MPa to 5 MPa.

[0085] By proceeding with the esterification reaction in this way, a carbonyl compound (tetraester compound) represented by the general formula (11) in which all of the R 4 in the formula (11) are groups other than hydrogen atoms can be obtained. When producing a carbonyl compound represented by the general formula (11) in which all of the R 4 in the formula (11) are hydrogen atoms, after introducing a group represented by the above formula: -COOR a by the esterification reaction, a hydrolysis treatment or a transesterification reaction with a carboxylic acid may be performed to convert such a group into a group represented by the formula: -COOH in which R a is a hydrogen atom. Such a reaction method is not particularly limited, and the formula: -COOR aA known method that can make the group represented by [[ID=]] (ester group) into -COOH (carboxy group) can be appropriately employed.

[0086] By thus carrying out step (1) and esterifying the olefin moiety in the norbornene ring in the starting compound (I), the starting compound (II) can be obtained. Note that the starting compound (II) is a norbornane compound having an exo-type steric structure in which a vinyl group is bonded to the exo position, and is the compound represented by the above formula (11). When obtaining such a starting compound (II), when by-products are present in the crude product obtained by carrying out step (1), known methods may be employed for appropriate purification. Note that R in formula (11) 1 , R 2 and R 4 are respectively synonymous with R in the above formula (3) 1 , R 2 and R 4 , and the preferred ones thereof are also synonymous.

[0087] 〈Regarding step (2)〉 Step (2) is a step of obtaining the carbonyl compound precursor by heating a mixture of the starting compound (II) and dicyclopentadiene which may have a substituent to a temperature of 150°C or higher for reaction. Note that in such a step, the starting compound (II) uses the one obtained in the above step (1).

[0088] Also, the dicyclopentadiene which may have a substituent used in step (2) is dicyclopentadiene or a compound in which at least a part of the hydrogen atoms in dicyclopentadiene are substituted with a substituent. As such a substituent, one selected from the group consisting of alkyl groups having 1 to 10 carbon atoms, which is a group that can be selected as R in the above formula (3) 3 is mentioned. By using dicyclopentadiene which may have such a substituent, a substituent (R in the above formula (3)) in the system during heating 3It is possible to generate cyclopentadiene which may have a group that can be selected as (a molecule of dicyclopentadiene which may have a substituent is thermally decomposed to generate two molecules of cyclopentadiene which may have a substituent), and by the reaction (Diels - Alder reaction) of such cyclopentadiene with the raw material compound (II), a carbonyl compound precursor containing a compound having an exo / exo - type steric structure represented by the above formula (12), a compound having an endo / exo - type steric structure represented by the above formula (13), and its enantiomer (a compound having an exo / endo - type steric structure) can be obtained.

[0089] Thus, step (2) is a step for obtaining the target carbonyl compound precursor by using dicyclopentadiene which may have a substituent as a material for generating cyclopentadiene which may have a substituent, and reacting the cyclopentadiene which may have a substituent generated in the system by heating with the raw material compound (II) by a Diels - Alder reaction.

[0090] In such step (2), first, a mixture of the raw material compound (II) and dicyclopentadiene which may have a substituent is prepared. In such a mixture, the content ratio of the raw material compound (II) and dicyclopentadiene which may have a substituent is not particularly limited, but it is preferable that the molar ratio ([raw material compound (II)]:[dicyclopentadiene which may have a substituent]) is 1:0.5 to 1:1. By using each component in such a ratio, the reaction can proceed more efficiently.

[0091] In step (2), a solvent may be further added to the mixture, and the reaction may be allowed to proceed by heating in the solvent. Such a solvent is not particularly limited, but an organic solvent that can be used in a so-called Diels-Alder reaction can be preferably used. For example, an alcohol-based solvent (including a glycol-based solvent, a glycerin-based solvent, and other polyhydric alcohol-based solvents), a cellosolve-based solvent, an ether-based solvent, an amide-based solvent, and a nitrile-based solvent can be mentioned. When the mixture contains a solvent, it is preferable to use the solvent such that the total amount of the raw material compound (II) and dicyclopentadiene which may have a substituent in the mixed solution is about 10 to 50% by mass.

[0092] In step (2), the mixture is heated to a temperature of 150°C or higher (more preferably a temperature of 160 to 200°C). If such a heating temperature is less than the lower limit, it becomes difficult to thermally decompose dicyclopentadiene which may have a substituent to produce cyclopentadiene which may have a substituent, and it becomes difficult to efficiently obtain a carbonyl compound precursor.

[0093] When performing the reaction (Diels-Alder reaction) by heating in this way, a pressure vessel such as an autoclave may be used. In this case, heating may be started at normal pressure, or heating may be started at a predetermined pressure.

[0094] Thus, in step (2), various conditions (including the heating temperature) should be such that dicyclopentadiene which may have a substituent is thermally decomposed to generate cyclopentadiene which may have a substituent in the system, and a Diels-Alder reaction can be caused between the generated cyclopentadiene which may have a substituent and the raw material compound (II). Known conditions that can be used when performing the Diels-Alder reaction can be appropriately adopted.

[0095] By heating the mixture to a temperature of 150°C or higher and reacting it in this way, a carbonyl compound precursor can be obtained, which consists of a compound having an exo / exo-type steric structure represented by the above formula (12), a compound having an endo / exo-type steric structure represented by the above formula (13), and a compound having an exo / endo-type steric structure which is an enantiomer thereof. In the formulas (12) and (13), R 1 、R 2 、R 3 and R 4 are synonymous with R 1 、R 2 、R 3 and R 4 in the above formula (3), respectively, and preferred ones thereof are also synonymous.

[0096] 〈Regarding Step (3)〉 In Step (3), in the presence of a palladium catalyst and an oxidizing agent, the carbonyl compound precursor is reacted with an alcohol and carbon monoxide to obtain a carbonyl compound composed of the above carbonyl compound (A) and the above carbonyl compound (B), and then, if necessary, the content of the carbonyl compound (A) is adjusted to obtain the carbonyl compound of the present invention.

[0097] In such Step (3), in the presence of a palladium catalyst and an oxidizing agent, the step of reacting the carbonyl compound precursor with an alcohol and carbon monoxide can appropriately employ the same method and the same conditions as the "esterification reaction" described in Step (1), except that the carbonyl compound precursor is used instead of the raw material compound (I). Therefore, the same palladium catalyst, oxidizing agent, etc. as those described in Step (1) can be used.

[0098] In this way, by esterifying the carbonyl compound precursor (introducing an ester group to the carbon atom of the olefin site in the norbornene ring contained in the carbonyl compound precursor), a compound containing at least one carbonyl compound (B) selected from the group consisting of the carbonyl compound (A) having an exo / exo-type steric structure and / or the compound having an endo / exo-type steric structure and its enantiomer having an exo / endo-type steric structure can be obtained.

[0099] And in step (3), regarding the compound obtained by the esterification reaction, the content of the carbonyl compound (A) is adjusted as necessary to obtain the carbonyl compound of the present invention. Here, "adjusting the content of the carbonyl compound (A) as necessary" means that even if the content of the carbonyl compound (A) is not adjusted, when the carbonyl compound obtained after the esterification reaction is originally a carbonyl compound (A) which is one of the stereoisomers and has a content of 30 mol% or more, it is not necessary to deliberately perform a step of adjusting the content of the isomers for the obtained carbonyl compound, because in that case, it will correspond to the carbonyl compound of the present invention without performing the step of adjusting the content of the isomers. At the same time, when the carbonyl compound obtained after the reaction (the compound before adjusting the content of the stereoisomers) has a content of the carbonyl compound (A) which is one of the stereoisomers of less than 30 mol%, or when it is necessary to make the content of the carbonyl compound (A) higher as desired according to the use, etc., it means that a step of adjusting the content of the isomers may be performed to obtain a carbonyl compound having a higher content of the carbonyl compound (A).

[0100] In addition, as a process for adjusting the content of the carbonyl compound (A) in the compound obtained by the esterification reaction, there are no particular restrictions. For example, a method of adjusting the content of the carbonyl compound (A) by sublimation purification can be adopted by taking advantage of the fact that the sublimation temperature of the carbonyl compound (A) is higher than that of the carbonyl compound (B). For example, a method of adjustment using a so-called Kugelrohr can be adopted. In this case, after sublimating the compound for adjusting the content of the isomer, the types of isomers that are likely to remain precipitated in the high-temperature side sphere (Kugel) that is first cooled and the sphere (Kugel) on the lower temperature side than that are different due to the difference in sublimation temperature for each isomer. A method can be adopted in which the proportion of the isomer in the compound precipitated in each Kugel is appropriately adjusted based on the proportion of the isomer so as to obtain a desired content ratio. In this way, the carbonyl compound of the present invention can be obtained by adjusting the content of the carbonyl compound (A) to be 30 mol% or more based on the total amount of the carbonyl compounds (A) and (B).

[0101] In addition, R in the formula 4 When producing a carbonyl compound in which all of them are hydrogen atoms, after introducing a group represented by the above formula: -COOR a in the esterification reaction, in order to convert such a group into a group represented by the formula: -COOH in which R a is a hydrogen atom, a hydrolysis treatment or a transesterification reaction with a carboxylic acid may be performed. The method of such a reaction is not particularly limited, and a known method capable of converting a group represented by the formula: -COOR a (ester group) into a group represented by the formula: -COOH (carboxy group) can be appropriately adopted.

[0102] (Method for producing tetracarboxylic dianhydride) A method that can be suitably employed as a method for producing the tetracarboxylic dianhydride of the present invention will be described. As such a method for producing the tetracarboxylic dianhydride of the present invention, for example, in the presence of a palladium catalyst and an oxidizing agent, the compound represented by the general formula (10) (raw material compound (I)) is reacted with an alcohol and carbon monoxide to obtain the compound represented by the general formula (11) (raw material compound (II)) in step (1); A mixture of the raw material compound (II) and dicyclopentadiene which may have a substituent is heated to a temperature of 150 °C or higher and reacted to obtain a carbonyl compound precursor containing a compound having an exo / exo type steric structure represented by the formula (12), a compound having an endo / exo type steric structure represented by the formula (13), and / or a compound having an exo / endo type steric structure which is a mirror image thereof in step (2); In the presence of a palladium catalyst and an oxidizing agent, the carbonyl compound precursor is reacted with an alcohol and carbon monoxide to obtain a carbonyl compound composed of the above carbonyl compound (A) and the above carbonyl compound (B) in step (3'); The carbonyl compound is heated in a carboxylic acid having 1 to 5 carbon atoms using an acid catalyst to obtain a tetracarboxylic dianhydride composed of the acid dianhydride (A) and the acid dianhydride (B), and then, if necessary, the content of the acid dianhydride (A) is adjusted to obtain the carbonyl compound of the present invention in step (4); A method including these steps can be adopted. Hereinafter, each step will be described separately.

[0103] 〈Regarding steps (1) to (3')〉 In such a method, step (1) and step (2) are the same steps as step (1) and step (2) respectively described in the method for producing the carbonyl compound mentioned above. Further, step (3') is the same step as the step described in the method for producing the carbonyl compound mentioned above, except that the carbonyl compound precursor is esterified without performing the step of "adjusting the content of the carbonyl compound (A)" which is adopted as necessary, and the carbonyl compound is obtained as it is.

[0104] <Regarding step (4)> Step (4) is a step of obtaining the tetracarboxylic dianhydride of the present invention by heating a carbonyl compound (a carbonyl compound composed of the above carbonyl compound (A) and the above carbonyl compound (B); hereinafter, sometimes referred to as "raw material compound (III)") in a carboxylic acid having 1 to 5 carbon atoms using an acid catalyst (heating step), obtaining a tetracarboxylic dianhydride composed of the acid dianhydride (A) and the acid dianhydride (B), and then adjusting the content of the acid dianhydride (A) as necessary.

[0105] The acid catalyst used in step (4) is not particularly limited, and it may be a homogeneous acid catalyst or a heterogeneous acid catalyst (solid catalyst). Among such acid catalysts, from the viewpoint of ease of purification, it is preferably a homogeneous acid catalyst.

[0106] Such a homogeneous acid catalyst is not particularly limited, and a known homogeneous acid catalyst that can be used in a reaction to convert a carboxylic acid into an anhydride or a reaction to convert an ester compound into an acid anhydride can be appropriately used. Among such homogeneous acid catalysts, from the viewpoint of improving the reaction yield, trifluoromethanesulfonic acid, tetrafluoroethanesulfonic acid, nonafluorobutanesulfonic acid, and chlorodifluoroacetic acid are more preferable, and trifluoromethanesulfonic acid and tetrafluoroethanesulfonic acid are even more preferable. Note that such a homogeneous acid catalyst may be used alone or in combination of two or more.

[0107] In addition, the amount of the acid catalyst (more preferably a homogeneous acid catalyst) used is not particularly limited, but it is preferably such that the molar amount of the acid of the acid catalyst is 0.001 to 2.00 molar equivalents (more preferably 0.01 to 1.00 molar equivalents) with respect to the amount (molar amount) of the carbonyl compound (raw material compound (III)). If the amount of such an acid catalyst is less than the lower limit, the reaction rate tends to decrease. On the other hand, if it exceeds the upper limit, purification becomes somewhat difficult and the purity of the product tends to decrease. Here, the molar amount of the acid of the acid catalyst is the molar amount in terms of functional groups (such as sulfonic acid groups (sulfonyl groups) and carboxylic acid groups (carboxy groups)) in the acid catalyst.

[0108] Also, the amount of the acid catalyst (more preferably a homogeneous acid catalyst) used is preferably 0.1 to 100 parts by mass, and more preferably 1 to 20 parts by mass, with respect to 100 parts by mass of the carbonyl compound (raw material compound (III)). If the amount of such an acid catalyst is less than the lower limit, the reaction rate tends to decrease. On the other hand, if it exceeds the upper limit, side reaction products tend to be generated.

[0109] Furthermore, in such a method, the carbonyl compound is heated (heating step) in a carboxylic acid having 1 to 5 carbon atoms using the acid catalyst. Thus, in the heating step, a carboxylic acid having 1 to 5 carbon atoms (hereinafter, sometimes simply referred to as "lower carboxylic acid") is used. Examples of such lower carboxylic acids include formic acid, acetic acid, propionic acid, butyric acid, etc. Among them, from the viewpoints of ease of production and purification, formic acid, acetic acid, and propionic acid are preferred, and formic acid and acetic acid are more preferred. Such lower carboxylic acids may be used alone or in combination of two or more. Also, the amount of such a lower carboxylic acid (for example, formic acid, acetic acid, propionic acid) used is not particularly limited, but it is preferably 4 to 100 times the molar amount of the carbonyl compound (raw material compound (III)).

[0110] In such a method, since the carbonyl compound (starting compound (III)) is heated in the lower carboxylic acid, it is preferable to contain the carbonyl compound in the lower carboxylic acid. The content of the carbonyl compound in such a lower carboxylic acid is preferably 1 to 40% by mass, more preferably 2 to 30% by mass.

[0111] In such a method, when the carbonyl compound (starting compound (III)) is a compound (tetracarboxylic acid) in which all of the R's in the formula are hydrogen atoms, the reaction (forward reaction) in which tetracarboxylic dianhydride and water are formed from the carbonyl compound (tetracarboxylic acid) proceeds by the heating step. And such a forward reaction and the reverse reaction in which the carbonyl compound (tetracarboxylic acid) is formed from tetracarboxylic dianhydride and water are equilibrium reactions. In such a method, when the carbonyl compound is a compound in which the R in the formula 4 is a group other than a hydrogen atom, the reaction (forward reaction) in which tetracarboxylic dianhydride, an ester compound of the lower carboxylic acid, and water are formed from the carbonyl compound and the lower carboxylic acid proceeds by the heating step. And such a forward reaction and the reverse reaction in which the carbonyl compound and the lower carboxylic acid are formed from the carboxylic anhydride, the ester compound of the lower carboxylic acid, and water are equilibrium reactions. Therefore, in such a heating step, it is also possible to efficiently advance the reaction (forward reaction) by appropriately changing the concentration of the components in the system and the like. 4

[0112] In addition, the conditions that can be adopted in such a heating process (including heating temperature, atmosphere conditions, etc.) are not particularly limited. In the lower carboxylic acid using the acid catalyst, the carbonyl compound (raw material compound (III)) is heated, and thereby, if it is a method (condition) capable of converting the ester group and / or carboxy group (carboxylic acid group) in the carbonyl compound into an acid anhydride group, the conditions can be appropriately adopted. For example, conditions such as those employed in known reactions capable of forming an acid anhydride group (e.g., the conditions for forming an acid anhydride described in International Publication No. WO2018 / 147373) can be appropriately utilized.

[0113] In addition, in such a heating process, first, it is preferable to prepare a mixture of the lower carboxylic acid, the carbonyl compound, and the acid catalyst so that heating in the lower carboxylic acid becomes possible. The method for preparing such a mixture is not particularly limited and may be appropriately prepared according to the apparatus used in the heating process, etc. For example, it may be prepared by adding (introducing) these into the same container. In addition, in such a heating process, another solvent may be added to and used with the lower carboxylic acid. Examples of such a solvent (other solvent) include aromatic solvents such as benzene, toluene, xylene, and chlorobenzene; ether solvents such as ether, THF, and dioxane; ester solvents such as ethyl acetate; hydrocarbon solvents such as hexane, cyclohexane, heptane, and pentane; nitrile solvents such as acetonitrile and benzonitrile; halogen solvents such as methylene chloride and chloroform; ketone solvents such as acetone and MEK; and amide solvents such as DMF, NMP, DMI, and DMAc.

[0114] In addition, although the temperature conditions for heating the carbonyl compound (starting compound (III)) in the lower carboxylic acid are not particularly limited, it is preferable to set the upper limit of the heating temperature to 180 °C (more preferably 150 °C, still more preferably 140 °C, particularly preferably 130 °C). On the other hand, it is preferable to set the lower limit of the heating temperature to 80 °C (more preferably 100 °C, still more preferably 110 °C). Further, such a heating temperature is preferably set to a temperature lower than the boiling point of the homogeneous acid catalyst within the range of the above temperature conditions.

[0115] In addition, in the heating step, from the viewpoint of more efficiently producing the tetracarboxylic anhydride, the step of refluxing the mixture (the mixture of the lower carboxylic acid, the carbonyl compound, and the acid catalyst) by heating may be included. Thus, by including the reflux step in the heating step, it becomes possible to more efficiently produce the carboxylic anhydride.

[0116] Here, the degree of progress of the forward reaction can be determined by checking the amount of by-products (such as water or ester compounds of lower carboxylic acids) contained in the vapor. Therefore, when performing a reflux step, while checking the amount of by-products (such as ester compounds of lower carboxylic acids) in the vapor, the reflux time is appropriately set so that the reaction proceeds efficiently, and then, a step of removing the distillate components may be performed while heating. By performing the step of removing the distillate components in this way, by-products (such as ester compounds of lower carboxylic acids and water) can be removed from the reaction system, and it becomes possible to make the forward reaction proceed more efficiently. Further, during the step of removing the distillate components, when the lower carboxylic acid decreases when the distillate components (vapor) are appropriately distilled off (for example, as by-products, an ester compound of a lower carboxylic acid and water are generated, the carboxylic acid is consumed, and as a result, the carboxylic acid decreases when the vapor is distilled off, etc.), it is preferable to appropriately add (continuously in some cases) the decreased amount of the lower carboxylic acid and perform heating. Further, when such a heating step includes a step of refluxing the mixture, the reflux conditions are not particularly limited, and known conditions can be appropriately adopted, and can be appropriately changed to suitable conditions according to the type of carbonyl compound (raw material compound) used, etc.

[0117] Further, the pressure conditions (reaction pressure conditions) when heating the carbonyl compound (raw material compound (III)) in the lower carboxylic acid are not particularly limited, and it may be under normal pressure, under pressurized conditions, or under reduced pressure conditions, and the reaction can proceed under any conditions. For example, when adopting the above-mentioned reflux step, the reaction may be carried out under pressurized conditions by the vapor of the lower carboxylic acid serving as a solvent. Further, such pressure conditions are preferably 0.001 to 10 MPa, and more preferably 0.1 to 1.0 MPa.

[0118] In addition, the atmosphere gas when heating the carbonyl compound (raw material compound (III)) in the lower carboxylic acid is not particularly limited, and for example, it may be air or an inert gas (nitrogen, argon, etc.). In order to efficiently volatilize by-products (ester compounds and water of the lower carboxylic acid) generated in the reaction and make the reaction proceed more efficiently (to shift the equilibrium reaction of transesterification in the production system), the above gas (preferably an inert gas such as nitrogen or argon) may be bubbled, or stirring may be carried out while introducing air into the gas phase part of the reactor (reaction vessel).

[0119] In addition, the heating time when heating the carbonyl compound (raw material compound (III)) in the lower carboxylic acid is not particularly limited, but it is preferably 0.5 to 100 hours, and more preferably 1 to 50 hours. When heating the carbonyl compound (raw material compound (III)) in the lower carboxylic acid, from the viewpoint of allowing the reaction to proceed uniformly, the reaction may be allowed to proceed while stirring the lower carboxylic acid into which the carbonyl compound has been introduced (more preferably, a mixture of the lower carboxylic acid, the carbonyl compound, and the acid catalyst).

[0120] Furthermore, in the step of heating the carbonyl compound (raw material compound (III)) in the lower carboxylic acid (heating step), it is preferable to use acetic anhydride together with the lower carboxylic acid. When using such acetic anhydride, the amount used is not particularly limited, but it is preferably 4 to 100 times the molar amount of the carbonyl compound (raw material compound (III)).

[0121] Also, even when using acetic anhydride in this way, it is preferable to adopt the conditions such as temperature conditions, pressure conditions, atmosphere gas conditions, heating time conditions, etc. during heating as the conditions described in the above heating step. Further, when using acetic anhydride in this way, it is preferable that the heating step is a step of refluxing the mixture. In this way, when refluxing is performed using acetic anhydride, it is possible to sufficiently progress the reaction only by performing the reflux step without performing steps such as distilling off the vapor and adding a lower carboxylic acid according to the amount used, etc., and it is also possible to produce the tetracarboxylic dianhydride more efficiently.

[0122] By performing such a heating step, it is possible to obtain a tetracarboxylic dianhydride composed of the acid dianhydride (A) and the acid dianhydride (B) from the carbonyl compound (raw material compound (III)).

[0123] And in step (4), with respect to the tetracarboxylic dianhydride obtained by subjecting to the heating step, the content of the acid dianhydride (A) is adjusted as necessary to obtain the tetracarboxylic dianhydride of the present invention. Here, "as necessary" regarding the step of adjusting the content of the acid dianhydride (A) means that even if the content of the acid dianhydride (A) is not adjusted, by the heating step, if a tetracarboxylic dianhydride in which the content of the acid dianhydride (A), which is one of the stereoisomers, is 30 mol% or more with respect to the total amount of the acid dianhydride (A) and the acid dianhydride (B) is obtained, then for the obtained tetracarboxylic dianhydride, it is not necessary to deliberately perform a step of adjusting the content of the isomers, and in that case, it means that it is not necessary to deliberately perform a step of adjusting the content of the isomers. Also, when the tetracarboxylic dianhydride (compound before adjusting the content of the stereoisomers) obtained by the heating step has a content of the acid dianhydride (A), which is one of the stereoisomers, of less than 30 mol% with respect to the total amount of the acid dianhydride (A) and the acid dianhydride (B), or when it is necessary to make the content of the acid dianhydride (A) higher as desired depending on the use or the like, it means that a step of adjusting the content of the isomers may be performed in order to obtain a tetracarboxylic dianhydride having a higher content of the acid dianhydride (A).

[0124] In addition, the process for adjusting the content of the acid dianhydride (A) is not particularly limited. For example, a method of adjusting the content of the acid dianhydride (A) by sublimation purification can be adopted by utilizing the fact that the sublimation temperature of the acid dianhydride (A) is higher than that of the acid dianhydride (B). For example, a method of adjustment using a so-called Kugelrohr can be adopted. In this case, after sublimating the tetracarboxylic dianhydride for adjusting the content of the isomer, based on the fact that the types of isomers that are likely to precipitate and remain are different depending on the difference in sublimation temperature for each isomer in the sphere (Kugel) on the high-temperature side that is first cooled and the sphere (Kugel) on the lower-temperature side than that, a method of appropriately adjusting so as to obtain a desired content ratio based on the ratio of the isomers in the compound precipitated in each Kugel can be adopted. In this way, by obtaining a tetracarboxylic dianhydride in which the content of the acid dianhydride (A) is 30 mol% or more based on the total amount of the acid dianhydrides (A) and (B), the carbonyl compound of the present invention can be obtained.

[0125] As described above, a method that can be preferably adopted as a method for producing the tetracarboxylic dianhydride of the present invention based on the method including steps (1) to (4) has been described. However, the method for producing the tetracarboxylic dianhydride of the present invention is not limited to the above method. For example, the carbonyl compound of the present invention can be prepared in advance, and the carbonyl compound of the present invention can be heated in a carboxylic acid having 1 to 5 carbon atoms using an acid catalyst to obtain the tetracarboxylic dianhydride of the present invention. In addition, the heating step (the step of heating in a carboxylic acid having 1 to 5 carbon atoms using an acid catalyst) in such a method is preferably the same as the heating step described in the above step (4).

[0126] [Polyimide] The polyimide of the present invention contains at least one repeating unit (A) having an exo / exo type steric structure represented by the above general formula (5), and / or a structural unit (repeating unit) having an endo / exo type steric structure represented by the above general formula (6) and a structural unit (repeating unit) having an exo / endo type steric structure which is a mirror image thereof, and the content of the repeating unit (A) relative to the total amount of the repeating units (A) and (B) is 30 to 100 mol% in terms of molar ratio. The repeating unit (B) may contain a structural unit (repeating unit) having an endo / exo type steric structure alone, may contain a structural unit (repeating unit) having an exo / endo type steric structure alone, or may contain both of them.

[0127] R in such general formulas (5) and (6) 1 、R 2 and R 3 are the same as R 1 、R 2 and R 3 in the above general formula (1), respectively, and preferred ones thereof are also the same as R 1 、R 2 and R 3 in the above general formula (1). In such general formulas (5) and (6), a plurality of R 1 may be the same or different from each other, but from the viewpoint of ease of purification and the like, it is preferably the same. Further, in general formulas (5) and (6), R 2 and R 3 may be the same or different from each other, but from the viewpoint of ease of purification and the like, it is preferably the same.

[0128] Also, R in the above general formulas (5) and (6) 5The arylene group that can be selected as such is an arylene group having 6 to 50 carbon atoms. Further, the number of carbon atoms of such an arylene group is preferably 6 to 40, more preferably 6 to 30, and even more preferably 12 to 20. If the number of carbon atoms is less than the lower limit, the heat resistance of the polyimide tends to decrease. On the other hand, if it exceeds the upper limit, the solubility of the obtained polyimide in a solvent decreases, and the moldability into a film or the like tends to decrease.

[0129] R in the repeating units represented by such general formulas (5) and (6) 5 (arylene group having 6 to 50 carbon atoms) is represented by the following formula (16): H2N-R5-NH2(16) [In formula (16), R 5 represents an arylene group having 6 to 50 carbon atoms.] is preferably the residue obtained by removing two amino groups from the diamine compound represented by the above formula (16) (thus, it is preferable to use the diamine compound represented by the above formula (16) as a raw material compound and introduce R 5 as a residue into the repeating unit). Such a diamine compound (R 5The raw material compound used for introduction into the repeating unit) is not particularly limited, and known diamine compounds (for example, aromatic diamines described in International Publication No. 2018 / 147373) can be appropriately used. Examples of such diamine compounds include 1,4-diaminobenzene, 1,3-diaminobenzene, 2,4-diaminotoluene, 2,5-diaminotoluene, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 2,4'-diaminodiphenyl ether, 2,2'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 3,7-diamino-dimethyldibenzothiophene-5,5-dioxide, 4,4'-diaminobenzanilide, 3,3'-diaminobenzophenone, bis(4-aminophenyl) sulfide, 1,3-bis(4-aminophenoxy)propane, 1,4-bis(4-aminophenoxy)butane, 1,5-bis(4-aminophenoxy)pentane, 1,3-bis(4-aminophenoxy)-2,2-dimethylpropane, 1,2-bis[2-(4-aminophenoxy)ethoxy]ethane, 9,9-bis(4-aminophenyl)fluorene, 5(6)-amino-1-(4-aminomethyl)-1,3,3-trimethylindane, 1,4-bis(4-aminophenoxy)benzene, 1,4-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, 4,4'-bis(3-aminophenoxy)biphenyl, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, bis[4-(3-aminophenoxy)phenyl]sulfone, bis[4-(4-aminophenoxy)phenyl]sulfone, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 3,3'-dicarboxy-4,4'-diaminodiphenylmethane, 4,6-dihydroxy-1,3-phenylenediamine, 3,3'-dihydroxy-4,4'-diaminobiphenyl, 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane, 3,3',4,4'-tetraaminobiphenyl, 1,3-bis(3-aminopropyl)tetramethyldisiloxane, 1,6-diaminohexane, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, 4,4'-methylenebis(4-cyclohexylamine), trans-1,4-cyclohexanediamine, bicyclo[2.2.1]heptane bis(methylamine), tricyclo[3.3.1.13,7]decane-1,3-diamine, 4-aminobenzoic acid 4-aminophenyl, 2-(4-aminophenyl)aminobenzoxazole, 9,9-bis[4-(4-aminophenoxy)phenyl]fluorene, 2,2'-bis(3-sulfopropyl)oxy-4,4'-diaminobiphenyl, 4,4'-bis(4-aminophenoxy)biphenyl-3,3'-disulfonic acid, bis(4-aminophenyl)terephthalate, etc. are mentioned. Such diamine compounds may be used alone or in combination of two or more kinds.,

[0130] Also, R 5 As the diamine compound used as a raw material compound for introducing into the repeating unit, among others, 2,2-bis[4-(4-aminophenoxy)phenyl]propane (abbreviation: BAPP), 2,2'-bis(trifluoromethyl)benzidine (abbreviation: TFMB), 4,4'-diaminobenzanilide (abbreviation: DABAN), p-phenylenediamine (abbreviation: PPD), bis(4-aminophenyl)terephthalate (abbreviation: BPTP), 4,4'-diaminodiphenyl ether (abbreviation: ODA), 1,3-diaminobenzene, 9,9-bis(4-aminophenyl)fluorene, 4-aminobenzoic acid 4-aminophenyl are preferable, and BAPP, ODA, BPTP, DABAN, PPD, TFMB are more preferable. The method for producing such diamine compounds is not particularly limited, and known methods can be appropriately adopted. Also, commercially available ones of such diamine compounds may be appropriately used.,

[0131] In addition, the polyimide of the present invention contains at least one repeating unit (B) selected from the group consisting of a repeating unit (A) having an exo / exo-type steric structure represented by the above general formula (5), and / or a structural unit (repeating unit) having an endo / exo-type steric structure represented by the following general formula (6) and a structural unit (repeating unit) having an exo / endo-type steric structure which is a mirror image thereof, and the content of the repeating unit (A) relative to the total amount of the repeating units (A) and (B) is 30 to 100 mol% in terms of molar ratio.

[0132] Thus, the content of the repeating unit (A) having an exo / exo-type steric structure is 30 to 100 mol% with respect to the total molar amount of the repeating units (A) and (B). By setting the content of such a repeating unit (A) to be not less than the above lower limit, it is possible to have a higher level of heat resistance. Further, from the viewpoint of obtaining higher mechanical strength, the content of the repeating unit (A) relative to the total molar amount of the repeating units (A) and (B) is more preferably 40 to 100 mol%, still more preferably 60 to 100 mol%, particularly preferably 80 to 100 mol%, and most preferably 90 to 100 mol%.

[0133] Such a polyimide of the present invention is preferably composed of a polycondensate of an acid dianhydride monomer containing the tetracarboxylic dianhydride of the present invention and the diamine compound. By using the tetracarboxylic dianhydride of the present invention as a raw material and carrying out polycondensation with the diamine compound, it is possible to efficiently obtain a polyimide containing the repeating unit (A) and / or the repeating unit (B) and having a content of the repeating unit (A) of 30 to 100 mol% relative to the total molar amount of the repeating units (A) and (B).

[0134] In addition, as such polyimide, those mainly containing the repeating unit (A) and / or the repeating unit (B) (more preferably, the total amount of the repeating units (A) and (B) is 50 to 100 mol% (more preferably 70 to 100 mol%, particularly preferably 80 to 100 mol%, most preferably 90 to 100 mol%) based on all the repeating units in the polyimide) are preferred. In such a polyimide, other repeating units may be included as long as the effects of the present invention are not impaired. Such other repeating units are not particularly limited, and examples include known repeating units that can be used as the repeating unit of polyimide, such as repeating units derived from other tetracarboxylic dianhydrides other than the tetracarboxylic dianhydride of the present invention and the diamine compound. Thus, other repeating units can be easily introduced into the polyimide, for example, when the polyimide of the present invention is a polycondensate of an acid dianhydride monomer containing the tetracarboxylic dianhydride of the present invention and the diamine compound, by using the acid dianhydride monomer containing the tetracarboxylic dianhydride of the present invention and other tetracarboxylic dianhydrides.

[0135] Such other tetracarboxylic dianhydrides are not particularly limited, and known ones that can be used in the production of polyimides can be appropriately used. For example, pyromellitic dianhydride, 3,4'-oxydiphthalic dianhydride, 4,4'-oxydiphthalic dianhydride, biphenyl-3,4,3',4'-tetracarboxylic dianhydride, benzophenone-3,4,3',4'-tetracarboxylic dianhydride, diphenyl sulfone-3,4,3',4'-tetracarboxylic dianhydride, 4,4'-(2,2-hexafluoroisopropylidene)diphthalic dianhydride, m-terphenyl-3,4,3',4'-tetracarboxylic dianhydride, p-terphenyl-3,4,3',4'-tetracarboxylic dianhydride, cyclobutane-1,2,3,4-tetracarboxylic dianhydride, 3-carboxymethyl-1,2,4-cyclopentanetricarboxylic acid 1,4:2,3-dianhydride, cyclohexane-1,2,4,5-tetracarboxylic dianhydride, butane-1,2,3,4-tetracarboxylic dianhydride, naphthalene-1,4,5,8-tetracarboxylic dianhydride, bis(1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylic acid) 1,4-phenylene, norbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5'',6,6''-tetracarboxylic dianhydride (CpODA), the following formulas (17) to (18):

[0136] [Chemical formula]

[0137] Compounds represented by (the compound represented by the above formula (17) (abbreviation "BNBDA"), the compound represented by the above formula (18) (abbreviation "BzDA")), etc. can be mentioned. Such other tetracarboxylic dianhydrides may be used alone or in combination of two or more.

[0138] In addition, when the polyimide contains other repeating units together with the repeating units (A) and (B), the molar ratio ([total amount of the repeating units (A) and (B)]:[other repeating units]) may be 99.9:0.1 to 0.1:99.9. Further, when other repeating units are included, from the viewpoints of the heat resistance and transparency of the resulting polyimide, the ratio of the total amount (total amount) of the repeating units (A) and (B) to the content of other repeating units is preferably 9:1 to 5:5 (more preferably 9:1 to 7:3) in terms of molar ratio ([total amount of the repeating units (A) and (B)]:[content of other repeating units]).

[0139] As the polyimide of the present invention, those having a 5% weight loss temperature of 450 °C or higher are preferable, and those having a 5% weight loss temperature of 460 to 520 °C are more preferable. If the 5% weight loss temperature is less than the lower limit, high heat resistance cannot be obtained. On the other hand, if it exceeds the upper limit, it tends to be difficult to produce a polyimide having such properties. Such a 5% weight loss temperature can be determined by heating from room temperature (25 °C) to 40 °C while flowing nitrogen gas in a nitrogen gas atmosphere, starting from 40 °C, and heating under the condition of 10 °C / min. to measure the temperature at which the weight of the sample used decreases by 5%. In addition, when measuring, it is preferable to use the mass of the sample as 1.0 mg to 10 mg (more preferably 1.5 mg to 4.0 mg). By setting the mass of the sample within the above range, even if the mass of the sample is changed and measured, the same value can be measured for the same polyimide.

[0140] Also, as such a polyimide, those having a glass transition temperature (Tg) of 300 °C or higher are preferable, and those having a glass transition temperature (Tg) of 330 to 450 °C are particularly preferable. If such a glass transition temperature (Tg) is less than the lower limit, it tends to be difficult to achieve sufficient heat resistance. On the other hand, if it exceeds the upper limit, it tends to be difficult to produce a polyimide having such properties. Such a glass transition temperature (Tg) can be measured in a tensile mode using a thermomechanical analyzer (trade name "TMA8310" manufactured by Rigaku).

[0141] Furthermore, such a polyimide preferably has a coefficient of thermal expansion (CTE) of 0 to 100 ppm / K, more preferably 10 to 60 ppm / K. When such a coefficient of thermal expansion exceeds the above upper limit, peeling is likely to occur due to thermal history when combined with a metal or inorganic substance having a coefficient of thermal expansion in the range of 5 to 20 ppm / K. Also, when the coefficient of thermal expansion is less than the above lower limit, the solubility and film properties tend to decrease. As a method for measuring the coefficient of thermal expansion of such a polyimide, a polyimide film having a size of 20 mm in length and 5 mm in width (although the thickness of such a film is not particularly limited as it does not affect the measured value, it is preferably 10 to 30 μm.) is formed as a measurement sample, and a thermomechanical analyzer (trade name "TMA8310" manufactured by Rigaku) is used as a measurement device. Under a nitrogen atmosphere, in a tensile mode (49 mN), with a heating rate of 5°C / min, the value obtained by determining the average value of the change in length per degree Celsius in the temperature range of 100°C to 200°C is adopted.

[0142] Furthermore, such a polyimide preferably has a softening temperature of 300°C or higher, more preferably 330 to 450°C. When such a softening temperature is less than the above lower limit, it tends to be difficult to achieve sufficient heat resistance. On the other hand, when it exceeds the above upper limit, it tends to be difficult to manufacture a polyimide having such properties. Such a softening temperature can be measured in a penetration mode using a thermomechanical analyzer (trade name "TMA8310" manufactured by Rigaku). Also, when measuring, since the size of the sample (length, width, thickness, etc.) does not affect the measured value, the size of the sample may be appropriately adjusted to a size that can be mounted on the jig of the thermomechanical analyzer (trade name "TMA8310" manufactured by Rigaku) used.

[0143] In addition, as such a polyimide, those having a thermal decomposition temperature (Td) of 450°C or higher are preferable, and those having a thermal decomposition temperature (Td) of 460 to 520°C are more preferable. If such a thermal decomposition temperature (Td) is less than the lower limit, it tends to be difficult to achieve sufficient heat resistance. On the other hand, if it exceeds the upper limit, it tends to be difficult to manufacture a polyimide having such characteristics. Such a thermal decomposition temperature (Td) can be determined by measuring the temperature at the intersection of the tangent lines drawn on the decomposition curves before and after thermal decomposition under a nitrogen atmosphere at a heating rate of 10°C / min using a TG / DTA220 thermogravimetric analyzer (manufactured by SII NanoTechnology Inc.). When measuring, it is preferable to use a sample mass of 1.0 to 10 mg (more preferably 5 mg to 10 mg). By setting the sample mass within the above range, even if the sample mass is changed for measurement, the same value can be measured for the same polyimide. Furthermore, such a thermal decomposition temperature (Td) can also be measured simultaneously under the same conditions (under a nitrogen atmosphere, at a heating rate of 10°C / min) using the same apparatus as that for measuring the 5% weight loss temperature.

[0144] Furthermore, the number average molecular weight (Mn) of such a polyimide is preferably 1,000 to 1,000,000 in terms of polystyrene. If such a number average molecular weight is less than the lower limit, it tends to be difficult to achieve sufficient heat resistance. On the other hand, if it exceeds the upper limit, processing tends to be difficult. Also, the weight average molecular weight (Mw) of such a polyimide is preferably 1,000 to 5,000,000 in terms of polystyrene. If such a weight average molecular weight is less than the lower limit, it tends to be difficult to achieve sufficient heat resistance. On the other hand, if it exceeds the upper limit, processing tends to be difficult. Furthermore, the molecular weight distribution (Mw / Mn) of such a polyimide is preferably 1.1 to 5.0. If such a molecular weight distribution is less than the lower limit, production tends to be difficult. On the other hand, if it exceeds the upper limit, it tends to be difficult to produce a uniform film. Incidentally, the molecular weight (Mw or Mn) and the molecular weight distribution (Mw / Mn) of such a polyimide can be determined by converting the measured data to polystyrene using gel permeation chromatography as a measuring device. In such a polyimide, when it is difficult to measure the molecular weight, the molecular weight etc. may be estimated based on the viscosity of the polyamic acid used for the production of the polyimide, and a polyimide suitable for the application etc. may be selected and used.

[0145] Also, from the perspective of obtaining higher transparency, such polyimide with a total light transmittance of 80% or more (more preferably 85% or more, particularly preferably 87% or more) is more preferable. Further, from the perspective of obtaining higher transparency, such polyimide with a haze (turbidity) of 5 to 0 (more preferably 4 to 0, particularly preferably 3 to 0) is more preferable. Furthermore, from the perspective of obtaining higher transparency, such polyimide with a yellowness index (YI) of 5 to 0 (more preferably 4 to 0, particularly preferably 3 to 0) is more preferable. Such total light transmittance, haze (turbidity), and yellowness index (YI) can be easily achieved by appropriately selecting the type of polyimide and the like. Note that for such total light transmittance and haze (turbidity), as a measuring device, the value measured using a film made of polyimide with a thickness of 5 to 80 μm as a measurement sample using the product name "Haze Meter NDH-5000" manufactured by Nippon Denshoku Industries Co., Ltd. can be adopted. Also, for the yellowness index, the value measured using a film made of polyimide with a thickness of 5 to 80 μm as a measurement sample using the product name "Spectrophotometer SD6000" manufactured by Nippon Denshoku Industries Co., Ltd. can be adopted. Note that for the total light transmittance, haze (turbidity), and yellowness index (YI), as long as it is a film made of polyimide with a thickness of 5 to 80 μm, since the thickness is sufficiently thin and does not affect the measured value, the same value can be measured from the same polyimide. Therefore, for the measurement of the total light transmittance, haze (turbidity), and yellowness index (YI), a film having a thickness within the above range may be used. Also, the vertical and horizontal sizes of the measurement sample may be any size that can be placed at the measurement site of the above measuring device, and the vertical and horizontal sizes may be appropriately changed. Note that such total light transmittance is determined by performing measurement in accordance with JIS K7361-1 (issued in 1997), haze (turbidity) is determined by performing measurement in accordance with JIS K7136 (issued in 2000), and yellowness index (YI) is determined by performing measurement in accordance with ASTM E313-05 (issued in 2005).

[0146] Such a polyimide preferably has an elongation at break of 5% or more. If the elongation at break is less than the above lower limit, the toughness is low and it tends to be mechanically brittle. Such an elongation at break can be measured in accordance with the method described in "JIS K7161" of Japanese Industrial Standards.

[0147] The shape of such a polyimide is not particularly limited. For example, it may be in the form of a film, powder, or even pellet-shaped by extrusion molding. Thus, the polyimide of the present invention can be made into a film shape, pellet shape by extrusion molding, or appropriately formed into various shapes by known methods.

[0148] When the polyimide of the present invention is made into a film form, the form of the film (polyimide film) is not particularly limited as long as it is in a film form and can be appropriately designed into various shapes (such as disk-shaped, cylindrical (formed by processing the film into a cylindrical shape), etc.). The thickness of such a polyimide film (a film made of the polyimide of the present invention) is not particularly limited, but is preferably 1 to 500 μm, and more preferably 5 to 200 μm. If the thickness is less than the above lower limit, the strength tends to decrease and handling becomes difficult. On the other hand, if it exceeds the above upper limit, multiple coatings may be required or the processing may tend to become complicated.

[0149] In addition, such a polyimide may be used as a resin solution (varnish) of polyimide in a state of being dissolved in an organic solvent. As the organic solvent used for such a resin solution of polyimide (a resin solution containing the polyimide of the present invention and an organic solvent), the same ones as those used for the method for producing the polyimide precursor resin described later can be preferably used.

[0150] In addition, the uses for which the polyimide of the present invention can be utilized are not particularly limited, and it can be appropriately applied to known uses where polyimide can be used. Further, since the polyimide of the present invention has a sufficiently high transparency and a higher heat resistance, it can be used for films for flexible printed circuit boards, heat-resistant insulating tapes, wire enamels, semiconductor coating agents (e.g., semiconductor protective coating agents), liquid crystal alignment films, transparent conductive films for organic EL, films for organic EL lighting, flexible substrate films, flexible substrate films for organic EL, front films for flexible displays, back films for flexible displays, polyimide belts, coating agents, barrier films, sealing materials, interlayer insulating materials, passivation films, TAB (Tape Automated Bonding) tapes, optical waveguides, flexible transparent conductive films, transparent conductive films for organic thin-film solar cells, transparent conductive films for dye-sensitized solar cells, flexible gas barrier films, films for touch panels, seamless polyimide belts for copiers (so-called transfer belts), transparent electrode substrates (transparent electrode substrates for organic EL, transparent electrode substrates for solar cells, transparent electrode substrates for electronic paper, etc.), interlayer insulating films, sensor substrates, substrates for image sensors, reflectors for light-emitting diodes (LED) (reflectors for LED lighting: LED reflectors), covers for LED lighting, covers for LED reflector lighting, coverlay films, highly ductile composite substrates, resists for semiconductors, lithium-ion batteries, substrates for organic memories, substrates for organic transistors, substrates for organic semiconductors, materials for manufacturing color filter substrates, etc. are particularly useful. Further, such a polyimide can also have a lower dielectric tangent (tanδ) depending on its structure. Therefore, when the polyimide of the present invention is used for, for example, correlation insulating film materials for semiconductors, substrate films for flexible printed circuit boards (FPC), etc., it is also possible to sufficiently reduce transmission loss.Therefore, the polyimide of the present invention can also be suitably used for high-frequency band materials (such as large-scale integrated circuits (LSIs), electronic circuits, etc.). A method for manufacturing such a polyimide will be described later. The polyimide of the present invention has been described above. Hereinafter, the polyimide precursor resin of the present invention will be described.

[0151] [Polyimide Precursor Resin] The polyimide precursor resin of the present invention contains at least one repeating unit (B') selected from the group consisting of a repeating unit (A') having an exo / exo-type steric structure represented by the above general formula (7), and / or a structural unit (repeating unit) having an endo / exo-type steric structure represented by the above general formula (8) and a structural unit (repeating unit) having an exo / endo-type steric structure which is a mirror image thereof, and the content of the repeating unit (A') with respect to the total amount of the repeating units (A') and (B') is 30 to 100 mol% in terms of molar ratio.

[0152] Such a polyimide precursor resin can form the polyimide of the present invention by imidizing it (for example, when the polyimide precursor resin is a polyamic acid, by imidizing and dehydrating to form a closed ring). The polyimide precursor resin containing such a repeating unit (A') and / or (B') can be formed based on the tetracarboxylic dianhydride of the present invention and the diamine compound.

[0153] R in the above general formulas (7) and (8) 1 , R 2 , R 3 and R 5 are the same as 1 , R 2 , R 3 and R 5 in the above general formulas (5) and (6). Note that a plurality of R in such general formulas (7) and (8) 1may be the same or different from each other, but from the viewpoint of ease of purification and the like, it is preferably the same. Further, R in General Formulas (7) and (8) 2 and R 3 may also be the same or different from each other, but from the viewpoint of ease of purification and the like, it is preferably the same.

[0154] In General Formulas (7) and (8), one of the bonds represented by *1 and the bond represented by *2 is bonded to the carbon atom a (the carbon atom with the symbol a) that forms the norbornane ring, and the other of the bond represented by *1 and the bond represented by *2 is bonded to the carbon atom b (the carbon atom with the symbol b) that forms the norbornane ring. Also, in General Formulas (7) and (8), one of the bonds represented by *3 and the bond represented by *4 is bonded to the carbon atom c (the carbon atom with the symbol c) that forms the norbornane ring, and the other of the bond represented by *3 and the bond represented by *4 is bonded to the carbon atom d (the carbon atom with the symbol d) that forms the norbornane ring. The bonds represented by *1 to *4 may each take an exo-stereoconfiguration or an endo-stereoconfiguration with respect to the norbornane ring to which the bond is bonded, and the stereoconfigurations of the bonds represented by *1 to *4 are not particularly limited, but from the viewpoint of further improving reactivity or further lowering the linear expansion coefficient, it is preferable for all of them to take an exo-stereoconfiguration.

[0155] In addition, when the bonds *1 to *4 in the repeating unit are those obtained from a polyimide precursor resin under mild reaction conditions, they usually take an exo configuration with respect to the norbornane methylene head. This is because when the polyimide precursor resin is formed under mild reaction conditions, the configuration of the raw material compound (the acid dianhydride ring bonded to the norbornane ring basically takes an exo configuration with respect to the norbornane methylene head) is retained, and the bonds *1 to *4 take an exo configuration with respect to the norbornane methylene head. Thus, by retaining the exo configuration, when forming a polyimide using a polyimide precursor resin having such a configuration, the imidization reaction (condensation reaction) step can proceed more efficiently. Furthermore, the arrangement of bond *1 and bond *3 with respect to the polymer main chain may be either a cis configuration or a trans configuration, and the arrangement of bond *2 and bond *4 depends on the arrangement of bond *1 and bond *3, but this may also be either a cis configuration or a trans configuration. Generally, it is known that when the arrangement of bond *1 and bond *3 with respect to the polymer main chain is in a trans configuration, physical properties such as the linear expansion coefficient are improved.

[0156] Also, in the above general formulas (7) and (8), Y 1 is independently either a hydrogen atom, an alkyl group having 1 to 6 carbon atoms (preferably 1 to 3 carbon atoms), or an alkylsilyl group having 3 to 9 carbon atoms. Y 1 can change the type of its substituent and the introduction rate of the substituent by appropriately changing its production conditions. When such Y 1 are all hydrogen atoms (when it becomes a repeating unit of polyamic acid), the production of polyimide tends to be easy.

[0157] Also, Y in the above general formulas (7) and (8) 1 When it is an alkyl group having 1 to 6 carbon atoms (preferably 1 to 3 carbon atoms), the storage stability of the polyimide precursor resin tends to be more excellent. Also, when Y 1 is an alkyl group having 1 to 6 carbon atoms (preferably 1 to 3 carbon atoms), Y 1is more preferably a methyl group or an ethyl group.

[0158] In addition, Y in the above general formulas (7) and (8) 1 When Y is an alkylsilyl group having 3 to 9 carbon atoms, the solubility of the polyimide precursor resin tends to be superior. 1 When Y is an alkylsilyl group having 3 to 9 carbon atoms, 1 is more preferably a trimethylsilyl group or a t-butyldimethylsilyl group.

[0159] Such a polyimide precursor resin has a repeating unit Y 1 1) Polyamic acid (Y in the general formula of the repeating unit contained in the polyimide precursor resin) according to the type of the substituent 1 are hydrogen atoms), 2) polyamic acid ester (Y 1 at least a portion of which is an alkyl group), 3) polyamic acid silyl ester (Y 1 In addition, such polyimide precursor resins can be easily prepared by using the repeating units (A') and / or (B') in which Y in the general formula is an alkylsilyl group. 1 are all hydrogen atoms.

[0160] In addition, when the polyimide precursor resin is a polyamic acid, the intrinsic viscosity [η] of the polyamic acid is preferably 0.05 to 3.0 dL / g, more preferably 0.1 to 2.0 dL / g. If the intrinsic viscosity [η] is less than 0.05 dL / g, when a film-like polyimide is produced using the polyimide, the resulting film tends to be brittle. On the other hand, if the intrinsic viscosity [η] exceeds 3.0 dL / g, the viscosity is too high and the processability is reduced, and for example, when a film is produced, it is difficult to obtain a uniform film. In addition, in this specification, the "intrinsic viscosity [η]" is a value measured as follows. That is, first, N,N-dimethylacetamide is used as a solvent, and the polyamic acid is dissolved in the N,N-dimethylacetamide so that the concentration becomes 0.5 g / dL to obtain a measurement sample (solution). Next, the viscosity of the measurement sample is measured using a dynamic viscometer under a temperature condition of 30°C, and the obtained value is adopted as the intrinsic viscosity [η]. As such a kinematic viscometer, an Ostwald type viscometer (an automatic viscosity measuring device manufactured by CANNON (product name "mini-PV-HX")) is used.

[0161] In addition, Y in the above general formulas (7) and (8) 1 Regarding the above, when a group other than a hydrogen atom (an alkyl group and / or an alkylsilyl group) is introduced, the introduction rate (Y 1 Based on the total amount of 1 The ratio of Y 1 When at least a part of Y is an alkyl group and / or an alkylsilyl group, 1 It is preferable that 25% or more (more preferably 50% or more, and even more preferably 75% or more) of the total amount of Y be alkyl groups and / or alkylsilyl groups. 1 becomes a hydrogen atom). 1 By making alkyl groups and / or alkylsilyl groups account for 25% or more of the total amount of the polyimide precursor, the storage stability of the polyimide precursor tends to be improved.

[0162] In addition, the polyimide precursor resin (more preferably, polyamic acid) of the present invention has a content of the repeating unit (A') of 30 to 100 mol% in terms of molar ratio with respect to the total amount of the repeating units (A') and (B'). Thus, the content of the repeating unit (A') having an exo / exo type steric structure is 30 to 100 mol% with respect to the total molar amount of the repeating units (A') and (B'). By setting the content of such a repeating unit (A') to be equal to or higher than the lower limit, when a polyimide is produced using this, a polyimide having a higher level of heat resistance can be obtained. Further, from the viewpoint of obtaining higher mechanical strength, the content of the repeating unit (A') with respect to the total molar amount of the repeating units (A') and (B') is more preferably 40 to 100 mol%, still more preferably 60 to 100 mol%, particularly preferably 80 to 100 mol%, and most preferably 90 to 100 mol%.

[0163] Such a polyimide precursor resin (more preferably, polyamic acid) is preferably composed of an adduct or a derivative thereof of an acid dianhydride monomer containing the tetracarboxylic dianhydride of the present invention and the diamine compound. By using the tetracarboxylic dianhydride of the present invention as a raw material and subjecting it to an addition polymerization reaction with the diamine compound, a polyimide precursor resin containing the repeating unit (A') and / or the repeating unit (B') and having a content of the repeating unit (A') of 30 to 100 mol% with respect to the total molar amount of the repeating units (A') and (B') can be efficiently obtained.

[0164] Further, as the polyimide precursor resin (more preferably polyamic acid) of the present invention, those mainly containing a repeating unit composed of the repeating unit (A') and / or the repeating unit (B') (more preferably, the total amount of the repeating unit (A') and the repeating unit (B') is 50 to 100 mol% based on all repeating units) are more preferable. Further, in the polyimide precursor resin (more preferably polyamic acid) of the present invention, the total amount (total) of the repeating unit (A') and the repeating unit (B') is preferably 90 mol% or more, more preferably 95 to 100 mol%, and still more preferably 98 to 100 mol% based on all repeating units contained in the polyimide precursor resin (more preferably polyamic acid).

[0165] In such a polyimide precursor resin (more preferably, polyamic acid), other repeating units other than the repeating unit (A') and the repeating unit (B') may be included as long as the effects of the present invention are not impaired. Such other repeating units are not particularly limited, and examples thereof include known repeating units that can be used as repeating units of polyimide precursor resins (more preferably, polyamic acids). For example, repeating units derived from other tetracarboxylic dianhydrides other than the tetracarboxylic dianhydride of the present invention and the diamine compound are included. Thus, other repeating units can be easily introduced into the polyimide, for example, when the polyimide precursor resin of the present invention is an adduct of an acid dianhydride monomer containing the tetracarboxylic dianhydride of the present invention and the diamine compound, by using the acid dianhydride monomer containing the tetracarboxylic dianhydride of the present invention and other tetracarboxylic dianhydrides. Further, when such other repeating units are included, the molar ratio ([total amount of the repeating units (A') and (B')]:[other repeating units]) may be 99.9:0.1 to 0.1:99.9. Furthermore, when other repeating units are included, from the viewpoints of the heat resistance and transparency of the resulting polyimide, the ratio of the total amount (total amount) of the repeating units (A') and (B') to the content of other repeating units is preferably a molar ratio ([total amount of the repeating units (A') and (B')]:[content of other repeating units]) of 9:1 to 5:5 (more preferably 9:1 to 7:3).

[0166] Such a polyimide precursor resin (more preferably, polyamic acid) may be dissolved in an organic solvent to form a polyimide precursor resin solution (varnish). As the organic solvent used in such a polyimide precursor resin solution (a resin solution containing the polyimide precursor resin (more preferably, polyamic acid) of the present invention and an organic solvent), the same solvents as those used in the method for producing the polyimide precursor resin described below can be preferably used. Therefore, such a polyimide precursor resin solution may be prepared by carrying out the method for producing the polyimide precursor resin described below and using the reaction solution obtained after the reaction as the polyimide precursor resin solution as it is.

[0167] The content of the polyimide precursor resin in such a polyimide precursor resin solution is not particularly limited, but is preferably 1 to 80% by mass, and more preferably 5 to 50% by mass. If the content is less than the lower limit, the production of the polyimide film tends to be difficult. On the other hand, if it exceeds the upper limit, the production of the polyimide film also tends to be difficult. Such a polyimide precursor resin solution can be preferably used for the production of the polyimide of the present invention and can be preferably used for producing polyimides of various shapes. For example, such a polyimide precursor resin solution can be applied onto various substrates and imidized and cured to easily produce a polyimide in film form.

[0168] (Method for producing the polyimide precursor resin of the present invention) A method that can be preferably adopted as the method for producing the polyimide precursor resin of the present invention will be described.

[0169] The method for producing the polyimide precursor of the present invention is not particularly limited, and except that the type of the tetracarboxylic dianhydride is the tetracarboxylic dianhydride of the present invention, it is a known method known as a method for producing a polyimide precursor (for example, paragraph of International Publication No. 2018 / 147373)

[0170] A method similar to the method described in paragraph

[0200] (reaction conditions, etc.) can be appropriately adopted. Further, as a method for producing the polyimide precursor of the present invention, for example, in the presence of an organic solvent, the tetracarboxylic dianhydride of the present invention and the diamine compound (the diamine compound represented by the general formula (16)) are subjected to an addition polymerization reaction to obtain a polyimide precursor. A method can be mentioned as a preferred method.

[0170] As the organic solvent used in such a method, it is preferable that the organic solvent can dissolve both the tetracarboxylic dianhydride of the present invention and the diamine compound (more preferably, the organic solvent can also dissolve the formed polyimide precursor). Such an organic solvent is not particularly limited, and those that can be used in the production of polyimide can be appropriately used. For example, N-methyl-2-pyrrolidone (NMP), N,N-dimethylacetamide (DMAc), N,N-dimethylformamide, γ-butyrolactone (GBL), γ-caprolactone, tetramethylurea (N,N,N’,N’-tetramethylurea: TMU), dimethyl sulfoxide, δ-valerolactone, etc. can be mentioned. Such an organic solvent may be used alone or in combination of two or more.

[0171] The amount of the organic solvent used is preferably such that the total amount of the monomers used in the reaction (the total amount of the tetracarboxylic dianhydride of the present invention and the diamine compound) is 5 to 40% by mass (more preferably 10 to 25% by mass) with respect to the total amount of the reaction solution. Further, the amount of the diamine compound used is preferably such that when the total amount of the tetracarboxylic dianhydride used in the reaction is converted to 1 mol, the number of moles of the diamine compound is 0.9 to 1.1 mol. From the viewpoint of being able to further increase the degree of polymerization, it is more preferable that the number of moles of the diamine compound is 0.95 to 1.05 mol.

[0172] In addition, when subjecting the tetracarboxylic dianhydride of the present invention and the diamine compound to an addition polymerization reaction, the reaction temperature may be appropriately adjusted to a temperature at which these addition polymerization reactions can proceed, and is not particularly limited, but is preferably 15 to 100°C. Further, when performing such an addition polymerization reaction, although not particularly limited, for example, in the atmosphere, or under an inert atmosphere such as nitrogen, helium, argon, etc., a solution containing the tetracarboxylic dianhydride and the diamine compound is stirred at the reaction temperature for 3 to 100 hours. A method of reacting while stirring may be employed. In this way, by allowing the addition polymerization reaction between the tetracarboxylic dianhydride of the present invention and the diamine compound to proceed, a polyamic acid (Y in formulas (7) and (8)) suitable as a polyimide precursor of the present invention 1 (a polyimide precursor in which all are hydrogen atoms) can be obtained.

[0173] Here, as a production method in the case of producing a polyimide precursor resin containing a repeating unit (II) in which Y 1 in formulas (7) and (8) is other than a hydrogen atom, a known method may be appropriately adopted according to the design. For example, except for using the tetracarboxylic dianhydride of the present invention as the tetracarboxylic dianhydride, the methods described in paragraphs

[0170] to

[0200] of WO 2018 / 147373, paragraphs

[0165] to

[0174] A method similar to a known method (such as reaction conditions) described in the method described therein can be appropriately adopted.

[0174] (Method for producing the polyimide of the present invention) The method for producing the polyimide of the present invention is not particularly limited. For example, except for using the tetracarboxylic dianhydride of the present invention as the tetracarboxylic dianhydride, a known method for producing a polyimide by reacting a tetracarboxylic dianhydride with a diamine compound (for example, the method described in International Publication No. 2011 / 099518, the method described in International Publication No. 2015 / 163314, the method described in JP-A-2018-044180, the method described in International Publication No. 2018 / 066522, the method described in International Publication No. 2018 / 147373, the method described in International Publication No. 2018 / 051888, etc.) can be appropriately adopted in the same manner (reaction conditions, etc.).

[0175] Also, as a method suitably usable for manufacturing the polyimide of the present invention, for example, a method of forming a polyimide precursor resin (preferably polyamic acid (polyamic acid)) as described above, and then subjecting the polyimide precursor resin to ring-closing condensation (dehydration ring-closing: intramolecular condensation) to imidize it to obtain a polyimide can be exemplified. Thus, the method (conditions, etc.) for ring-closing condensation of the polyimide precursor resin (preferably polyamic acid) to imidize it is not particularly limited, and known imidization methods (for example, the method described in International Publication No. 2011 / 099518, the method described in International Publication No. 2015 / 163314, the method described in Japanese Patent Application Laid-Open No. 2018-044180, the method described in International Publication No. 2018 / 066522, the method described in International Publication No. 2018 / 147373, the method described in International Publication No. 2018 / 051888, etc.) can be appropriately adopted. As such a method for imidization, for example, a method of imidizing by heat-treating the polyamic acid under temperature conditions of 60 to 400°C (more preferably 150 to 350°C), or a method of imidizing using a so-called "imidizing agent" can be appropriately adopted. Such an imidizing agent is also not particularly limited, and known ones can be appropriately used. Examples include acid anhydrides such as acetic anhydride, propionic anhydride, and trifluoroacetic anhydride; tertiary amines such as pyridine, collidine, lutidine, triethylamine, and N-methylpiperidine; and the like. Further, the reaction temperature during imidization when imidizing using an imidizing agent is preferably -40°C to 200°C (more preferably 30 to 150°C).

[0176] Also, in a method that can be suitably used as a method for producing the polyimide of the present invention, in the presence of a reaction accelerator, the tetracarboxylic dianhydride and the diamine compound of the present invention are heated and reacted in an organic solvent, whereby the formation of the polyimide precursor resin and subsequent ring-closing condensation (imidization) are allowed to proceed simultaneously as a series of reactions to form a polyimide. Thereby, it is possible to efficiently produce a polyimide by allowing the formation of an intermediate polyimide precursor resin (preferably polyamic acid) and subsequent formation of polyimide (imidization) to proceed simultaneously. Further, when such a method is adopted, depending on the type of polyimide, it is also possible to obtain the polyimide in the state of a resin solution (polyimide varnish) of the polyimide after its production. Thus, the method of forming the polyimide precursor resin and subsequent ring-closing condensation (imidization) simultaneously as a series of reactions to form a polyimide is not particularly limited, and a known method (for example, the method described in International Publication No. 2018 / 051888, etc.) can be appropriately adopted. In addition, when such a method is adopted, as the organic solvent, the same solvents as those described in the method for producing the aforementioned polyimide precursor resin can be used. Furthermore, the reaction accelerator is not particularly limited, and known ones (for example, those described in International Publication No. 2018 / 051888, etc.) can be appropriately used. For example, triethylamine, diisopropylethylamine, N-methylpiperidine, and pyridine can be mentioned as suitable ones. Such a reaction accelerator may be used alone or in combination of two or more. Also, when heating in an organic solvent in the presence of a reaction accelerator, the heating temperature is not particularly limited, but it is preferably 150 to 200°C.

Examples

[0177] Hereinafter, the present invention will be described more specifically based on Examples and Comparative Examples, but the present invention is not limited to the following Examples.

[0178] In addition, the identification of the molecular structures and the like of the compounds obtained in each of the following examples and comparative examples was carried out by appropriately adopting measurements such as infrared absorption spectrum measurement (IR measurement) and nuclear magnetic resonance spectrum measurement (NMR measurement) according to the type of the compound. Here, for the IR measurement and NMR measurement, an IR measuring instrument (manufactured by Thermo Scientific, trade name: Nicolet 380 FT-IR spectrometer) and an NMR measuring instrument (manufactured by VARIAN, trade name: UNITY INOVA-600) were used as the measuring devices, respectively.

[0179] <1>Synthesis of the starting compound of the carbonyl compound (Synthesis Example 1: Synthesis of 2,3-di(methoxycarbonyl)-5-exo-vinylbicyclo[2.2.1]heptane) First, methanol (500 g), CuCl2(II) (59.2 g, 0.44 mol), exo-5-vinyl-2-norbornene (25.2 g, 0.21 mol), and Pd3(OAc)5(NO2) (122.1 mg, 0.54 mmol in terms of Pd) were added to a 1-L glass autoclave reactor to obtain a mixed solution. The "exo-5-vinyl-2-norbornene" used for the preparation of the mixed solution was previously produced with reference to the method described on pages 1954 - 1956 of Bull. Chem. Soc. Jpn. (vol. 60) issued in 1987, and "Pd3(OAc)5(NO2)" was previously produced by adopting the method described on page 1991 of Dalton Trans (vol. 11) issued in 2005 (note that all the "Pd3(OAc)5(NO2)" used in the following examples and the like described in this application were produced by the same method, and the description of the production method is omitted in the following description).

[0180] Next, after reducing the pressure inside the autoclave reactor to -0.08 MPaG, carbon monoxide was introduced into the autoclave reactor and adjusted so that the internal pressure became 0.03 MPaG. Next, after setting the temperature inside the autoclave reactor to 25°C and stirring the mixed solution for 4 hours, the temperature was gradually raised to 40°C while continuing stirring, and after continuing stirring for another 4 hours under the temperature condition of 40°C, the stirring of the mixed solution was stopped and left standing overnight (13.5 hours) to obtain a reaction solution as a brown suspension.

[0181] Next, the autoclave reactor was depressurized by removing the atmosphere gas containing carbon monoxide from inside the autoclave reactor, and the atmosphere gas inside the autoclave reactor was replaced with nitrogen. Then, while flowing nitrogen inside the autoclave reactor, the temperature was raised to 50 degrees Celsius, and it was confirmed that the concentration of carbon monoxide in the gas (exit gas) discharged from the autoclave reactor was 0 ppm. Thereafter, by further raising the temperature inside the autoclave reactor to 65 degrees Celsius, methanol was distilled off from the reaction solution to obtain a solid content. Next, toluene (760 g) was added to the inside of the autoclave reactor in which the solid content had precipitated to obtain a mixture of the solid content and toluene. Then, in order to completely remove methanol from the mixture, the pressure inside the autoclave reactor was reduced to -0.07 MPaG and the temperature was raised to 73 degrees Celsius, and a part of the solvent in the mixture was distilled off. Next, after further adding toluene (190 g) to the mixture, the temperature was raised to 80 degrees Celsius with stirring and filtration was performed to separate and recover the precipitate (solid content) and the filtrate. Next, the obtained precipitate was washed with toluene (190 g), and the washing solution was added to the filtrate. Then, while heating the filtrate and maintaining it at a temperature of 80 degrees Celsius, it was washed twice with 5 mass% hydrochloric acid (380 g), once with saturated brine (380 g), and once with ion-exchanged water (380 g). After washing in this way, the obtained organic layer was subjected to filter filtration to remove (separate) the solid content precipitated in the washing solution to obtain an organic layer. Next, the solid content removed from the washing solution was washed with toluene (190 g), and the washing solution was added to the organic layer. Next, the organic layer thus obtained (the organic layer obtained by liquid separation and purification) was concentrated under reduced pressure using an evaporator to obtain a crude product. Then, the obtained crude product was subjected to vacuum distillation to obtain a main fraction at a temperature of 113 degrees Celsius and a pressure of 14 Pa. For the structure confirmation of the main fraction thus obtained, IR measurement, NMR( 1 1H-NMR, 13When ^(13)C-NMR measurement was carried out, it was found that the obtained product was a mixture of a compound represented by the following general formula (20) (compound name: 2,3-di(methoxycarbonyl)-5-exo-vinylbicyclo[2.2.1]heptane) and a compound represented by the following general formula (21) (compound name: 2,3-di(methoxycarbonyl)-5-ethylidenebicyclo[2.2.1]heptane).

[0182]

Chemical formula

[0183] Therefore, the components in such a mixture were separated by preparative liquid chromatography, and 18 g (yield 36%) of 2,3-di(methoxycarbonyl)-5-exo-vinylbicyclo[2.2.1]heptane (the compound represented by the above general formula (20): the target product) was obtained. The purity of the 2,3-di(methoxycarbonyl)-5-exo-vinylbicyclo[2.2.1]heptane thus separated and obtained was determined by HPLC and GC measurements, and the purity was 99 area%.

[0184] (Synthesis Example 2: Synthesis of 2,2'-bi(bicyclo[2.2.1]heptane)-5'-ene-5,6'-dicarboxylic acid diester) First, 2,3-di(methoxycarbonyl)-5-exo-vinylbicyclo[2.2.1]heptane (100 g, 0.42 mol) prepared by performing the same method as in Synthesis Example 1 multiple times and dicyclopentadiene (31 g, 234 mmol) were added to an autoclave reactor with a capacity of 500 mL to obtain a mixture. Next, nitrogen was introduced so that the gauge pressure in the autoclave reactor became 0.034 MPa (5 psig), and then the internal temperature was raised to 180°C and the mixture was stirred for 4 hours. After stirring in this manner, the internal temperature of the autoclave reactor was cooled to room temperature (25°C), solids were precipitated in the reactor, and then the precipitate (solids) was taken out by filtration. Next, the precipitate was washed 3 times with toluene (30 mL) and then vacuum dried at 60°C to obtain 52 g of a product (crystals).

[0185] For the structural confirmation of the product thus obtained, IR measurement, NMR( 1 1H-NMR, 13 13C-NMR) measurement was carried out, and the obtained product had the following general formula (22):

[0186]

Chemical formula

[0187] It is 2,2'-bi(bicyclo[2.2.1]heptane)-5'-ene-5,6'-dicarboxylic acid diester (hereinafter, sometimes referred to as "BNBDE"), and it was confirmed that the yield was 41%. The obtained BNBDE is a stereoisomer A (hereinafter, sometimes referred to as "BNBDE-A") which is a compound having an exo / exo-type steric structure represented by the following general formula (23), and a compound having an endo / exo-type steric structure represented by the following general formula (24) and a stereoisomer B (hereinafter, sometimes referred to as "BNBDE-B". Since the endo / exo-type and exo / endo-type enantiomers cannot be spectroscopically distinguished, hereinafter, these are both evaluated as "stereoisomer B".) which is a mixture of compounds having an exo / endo-type steric structure. It was confirmed that the content ratio (molar ratio) of BNBDE-A and BNBDE-B in the obtained mixture was 1 / 3 (BNBDE-A / BNBDE-B).

[0188] [Chemical formula]

[0189] (2) Synthesis of carbonyl compounds (Example 1) First, into a 1-L glass autoclave reactor, methanol (470 g), CuCl2(II) (59.2 g, 0.44 mol), BNBDE (63.9 g, 0.21 mol: a mixture of BNBDE-A and BNBDE-B) prepared by repeating the same method as in Synthesis Example 2 a plurality of times, and Pd3(OAc)5(NO2) (122.1 mg, 0.54 mmol in terms of Pd) were added to obtain a mixed solution. Next, after evacuating the inside of the autoclave reactor to -0.08 MPaG, carbon monoxide was introduced into the autoclave reactor and adjusted so that the internal pressure became 0.03 MPaG. Then, with the internal temperature of the autoclave reactor set at 25°C, the mixed solution was stirred for 4 hours, and then while continuing stirring, the temperature was gradually raised to 40°C and stirring was continued for an additional 4 hours under the temperature condition of 40°C. After that, stirring of the mixed solution was stopped and it was allowed to stand overnight (13.5 hours) to obtain a reaction solution as a brown suspension.

[0190] Next, the autoclave reactor was depressurized by removing the atmosphere gas containing carbon monoxide from inside the autoclave reactor, and the atmosphere gas inside the autoclave reactor was replaced with nitrogen. Then, while flowing nitrogen through the autoclave reactor, the temperature was raised to 50°C, and it was confirmed that the concentration of carbon monoxide in the gas (exit gas) discharged from the autoclave reactor was 0 ppm. Thereafter, by further raising the temperature inside the autoclave reactor to 65°C, methanol was distilled off from the reaction solution to obtain a solid content. Next, toluene (760 g) was added to the inside of the autoclave reactor in which the solid content had precipitated to obtain a mixture of the solid content and toluene. Then, in order to completely remove methanol from the mixture, the pressure inside the autoclave reactor was reduced to -0.07 MPaG and the temperature was raised to 73°C, and a part of the solvent in the mixture was distilled off. Next, after further adding toluene (190 g) to the mixture, the temperature was raised to 80°C with stirring and filtration was performed to separate and recover the precipitate (solid content) and the filtrate. Next, the obtained precipitate was washed with toluene (190 g), and the washing solution was added to the filtrate. Then, while heating the filtrate and maintaining it at a temperature of 80°C, it was washed twice with 5 mass% hydrochloric acid (380 g), once with saturated aqueous sodium chloride solution (380 g), and once with ion-exchanged water (380 g). After washing in this manner, the obtained organic layer was subjected to filter filtration to remove (separate) the solid content precipitated in the washing solution to obtain an organic layer. Next, the solid content removed from the washing solution was washed with toluene (190 g), and the washing solution was added to the organic layer. Next, the organic layer thus obtained (the organic layer obtained by liquid separation and purification) was concentrated under reduced pressure at 60°C using an evaporator until the amount of toluene became 440 g to obtain a concentrated solution. Thereafter, recrystallization was performed by gradually cooling the concentrated solution to room temperature (25°C) to precipitate a solid content (crystals). Next, the solid content (crystals) thus obtained was collected by filtration, washed 4 times with toluene (25 g), and vacuum dried at 60°C to obtain 66 g of a product (white crystals).

[0191] For the structural confirmation of the product thus obtained, IR measurement, NMR( 1 1H-NMR, 13When the product obtained was subjected to 13C-NMR measurement, it was found to be 5,5'-bi-2-norbornene-5,5',6,6'-tetracarboxylic acid tetramethyl ester represented by the following general formula (25) (hereinafter sometimes referred to as "BNBTE"), and the yield was confirmed to be 74%. The obtained BNBTE is a stereoisomer A (hereinafter sometimes referred to as "BNBTE-A") which is a compound having an exo / exo-type steric structure represented by the following general formula (26), and a compound having an endo / exo-type steric structure represented by the following general formula (27) and its enantiomer having an exo / endo-type steric structure. It was confirmed that it is a mixture of stereoisomer B (hereinafter sometimes referred to as "BNBTE-B". Since the endo / exo-type and exo / endo-type enantiomers cannot be spectroscopically distinguished, hereinafter, these are collectively evaluated as "stereoisomer B"). The content ratio (molar ratio) of BNBTE-A and BNBTE-B in the obtained mixture was 1 / 3 (BNBDE-A / BNBDE-B).

[0192] [Chemical formula]

[0193]

[0194] [Chemical formula]

[0195] <3-1>Synthesis of Tetracarboxylic Anhydride (Example 2) ​Using the BNBTE (a mixture of BNBTE-A and BNBTE-B) obtained in Example 1, a tetracarboxylic dianhydride was prepared as follows. First, a 1-L reaction vessel was purged with nitrogen, and BNBTE (34 g, 80.5 mmol) obtained in Example 1, acetic acid (0.49 kg), and trifluoromethanesulfonic acid (0.30 g, 2.00 mmol) were added to obtain a mixed solution. Next, the temperature of the mixed solution was raised to 113 °C and maintained at that temperature (113 °C). While dropping acetic acid with a pump so that the liquid volume in the reaction vessel became constant, a step of distilling off vapor (such as acetic acid) was carried out. Next, every hour, the distillate distilled out of the system was analyzed by mass measurement and gas chromatography to confirm the progress of the reaction. By such analysis, it was confirmed that acetic acid, methyl acetate, and water were present in the distillate. Then, after the distillation of the vapor was started in this step, since the distillation of methyl acetate stopped after 6 hours had passed, heating was stopped and cooling was carried out to room temperature (25 °C). Next, the reaction solution was concentrated with an evaporator to obtain a crude product.

[0196] Next, the crude product thus obtained was subjected to sublimation purification by the following method. That is, first, for purification, the crude product was placed in a Kugel distillation apparatus (manufactured by Shibata Scientific Technology, GTO-2000, number of cooling spheres: 3). Next, at room temperature (25 °C), after reducing the pressure inside the apparatus to 0.12 Torr, the temperature was gradually increased stepwise to 200 °C and 250 °C (the heating rate was 10 °C / min, and it was held at each temperature of 200 °C and 250 °C for 30 minutes respectively), and finally the temperature was raised to 315 °C. After the temperature reached 315 °C in this way of raising the temperature, heating was continued for one and a half hours and then returned to room temperature. After the temperature reached 315 °C in this way of raising the temperature, heating was continued for one and a half hours and then returned to room temperature. Sublimation purification was thus carried out, and the product (precipitate) was precipitated in the first high-temperature side sphere (Kugel: hereinafter referred to as the "high-temperature part") and the second low-temperature side sphere (Kugel: hereinafter referred to as the "low-temperature part") among the three cooling spheres in the Kugel apparatus. In this way, 4 g (yield 15%) of the product (hereinafter, for convenience, referred to as the "high-temperature side product") was obtained from the high-temperature part, and 20 g (yield 75%) of the product (hereinafter, for convenience, referred to as the "low-temperature side product") was obtained from the low-temperature part.

[0197] Next, for the structure confirmation of the products (high-temperature side product and low-temperature side product) in each Kugel (cooling sphere), IR measurement and NMR ( 1 1H-NMR, 13 13C-NMR) measurements were carried out, and it was found that the products in each Kugel (cooling sphere) all had the following general formula (28):

[0198]

Chemical formula

[0199] It was confirmed that it is 5,5'-bi-2-norbornene-5,5',6,6'-tetracarboxylic acid-5,5',6,6'-di-anhydride (hereinafter sometimes referred to as "BNBDA"). The low-temperature side product is a stereoisomer A having an exo / exo-type steric structure represented by the following general formula (29) (hereinafter sometimes referred to as "BNBDA-A") in consideration of the results of the above structure confirmation (IR measurement, NMR measurement), etc., and a compound having an endo / exo-type steric structure represented by the following general formula (30) and a stereoisomer B composed of a compound having an exo / endo-type steric structure which is its enantiomer (hereinafter sometimes referred to as "BNBDA-B". Since the endo / exo-type and exo / endo-type enantiomers cannot be spectroscopically distinguished, these are both evaluated as "stereoisomer B".), and it was found that it is a mixture containing BNBDA-A and BNBDA-B at a ratio of 1 / 10 based on the molar ratio (BNBDA-A / BNBDA-B). On the other hand, the high-temperature side product was found to be a compound containing 100 mol% of BNBDA-A (BNBDA consisting only of stereoisomer A) in consideration of the results of the above structure confirmation (IR measurement, NMR measurement), etc.

[0200] [Chemical formula]

[0201] As a result of the NMR measurement during the structure confirmation, the NMR data of the high-temperature side product (BNBDA-A) 1 1H-NMR and 13 13C-NMR measurement results) are shown below. 1 1H-NMR (600 MHz, DMSO) δ = 1.00 (dd, 2H), 1.21 (dd, 2H), 1.43 (dt, 2H), 1.61 - 1.70 (m, 2H), 1.72 - 1.85 (m, 2H), 2.50 - 2.53 (m, 2H), 2.55 - 2.60 (m, 2H), 3.11 (d, 2H), 3.30 (d, 2H) 1313C-NMR (600 MHz, DMSO) δ = 27.9, 34.8, 38.7, 39.7, 46.2, 47.4, 48.8, 172.2, 173.2.

[0202] (Comparative Example 1) Using the same method as Comparative Example 2 of International Publication No. 2018 / 147373, a compound containing 100 mol% of BNBDA-B (stereoisomer B consisting of a compound having an endo / exo-type steric structure represented by the above general formula (30) and an exo / endo-type steric structure which is an enantiomer thereof) (BNBDA consisting only of stereoisomer B) was prepared.

[0203] (Comparative Example 2) Using the same method as Example 2 of International Publication No. 2018 / 147373, a compound containing 100 mol% of stereoisomer C having an endo / endo-type steric structure represented by the following general formula (31) (hereinafter sometimes referred to as "BNBDA-C") (BNBDA consisting only of stereoisomer C) was prepared.

[0204] [Chemical formula]

[0205] <4>Synthesis of Polyimide Before explaining the polyimide synthesis methods employed in each example, etc., first, the abbreviations of the diamine compounds used in the polyimide synthesis are shown below. All of the compounds used commercially available products.

[0206] BAPP: 2,2-Bis[4-(4-aminophenoxy)phenyl]propane (manufactured by Seika Corporation) ODA: 4,4'-Diaminodiphenyl ether (manufactured by Seika Corporation) BPTP: Bis(4-aminophenyl)terephthalate (manufactured by Seika Corporation) DABAN: 4,4'-Diaminobenzanilide (manufactured by Seika Corporation) PPD: p-Phenylenediamine (manufactured by Seika Corporation) TFMB: 2,2'-Bis(trifluoromethyl)benzidine (manufactured by Seika Corporation).

[0207] (Example 3) 〈Preparation Process of Polyamic Acid〉 First, using the low-temperature side product obtained in Example 2 (a mixture containing BNBDA-A and BNBDA-B in a ratio of 1 / 10 based on the molar ratio (BNBDA-A / BNBDA-B)) and the high-temperature side product (a compound containing 100 mol% of BNBDA-A), these were mixed so that the molar ratio of BNBDA-A to BNBDA-B (BNBDA-A / BNBDA-B) was 3 / 7, and 1.65 g (5.00 mmol) of a tetracarboxylic dianhydride with a molar ratio of BNBDA-A to BNBDA-B of 3 / 7 was prepared.

[0208] Next, under a nitrogen atmosphere, BAPP (2.05 g, 5.00 mmol) as a diamine compound was introduced into a 20 mL screw tube, and a tetracarboxylic dianhydride (1.65 g, 5.00 mmol) with a molar ratio of BNBDA-A to BNBDA-B of 3 / 7 was introduced. Then, 14.8 g of N-methyl-2-pyrrolidone (NMP) was added to the screw tube to obtain a mixed solution. Next, the obtained mixed solution was stirred at room temperature (25°C) for 3.5 hours under a nitrogen atmosphere to produce polyamic acid (PAA), and a reaction solution (PAA solution: PAA varnish) containing such polyamic acid was obtained. Using a part of the reaction solution (solvent: NMP) thus obtained, the solvent was removed to isolate polyamic acid, and then the polyamic acid was dissolved in N,N-dimethylacetamide so that the concentration became 0.5 g / dL to prepare a measurement sample (solution). As described above, the intrinsic viscosity [η] of the polyamic acid was measured, and as a result, the intrinsic viscosity [η] was 0.65 dL / g.

[0209] 〈Preparation Process of Film Composed of Polyimide (Thermal Imidization Process)〉 The reaction solution (PAA varnish) obtained in the step of preparing the polyamic acid was spin-coated onto a glass plate made of a large slide glass (product name "S9213" manufactured by Matsunami Glass Industry Co., Ltd., vertical: 76 mm, horizontal: 52 mm, thickness: 1.3 mm) to form a coating film. Then, the glass plate with the coating film formed thereon was placed in an oven, the temperature condition was set to 60°C, and it was left standing for 4 hours in a nitrogen atmosphere. After that, the temperature condition was changed to 300°C (final film-forming temperature), and it was left standing at 300°C for 1 hour to cure the coating film, thereby obtaining a polyimide-coated glass having a thin film (film made of polyimide) coated on the glass plate.

[0210] Next, the polyimide-coated glass thus obtained was taken out of the oven and immersed in hot water at 90°C for 0.5 hour, and the film was peeled off from the glass plate and recovered to obtain a film made of polyimide with a film thickness of 6 μm. Regarding the obtained film made of polyimide, when its color was visually confirmed, it was confirmed to be colorless and transparent. When the IR spectrum of the film thus obtained was measured, C=O stretching vibration of imide carbonyl was observed at 1705 cm -1 , 1775 cm -1 . From this, it was confirmed that the obtained film was made of polyimide.

[0211] (Examples 4 to 8 and Comparative Examples 3 to 5) The types (ratios, etc.) of isomers in the tetracarboxylic dianhydride, the amount of the tetracarboxylic dianhydride used, the types and amounts of the diamine compounds used, the types and amounts of the solvents used, and the final film-forming temperature in the polyimide preparation process were changed as described in Table 1, respectively. Films made of polyimide were obtained in the same manner as in Example 3, except for the above changes. When the IR spectra of the films obtained in Examples 4 to 8 and Comparative Examples 3 to 5 were measured, absorption peaks of C=O stretching vibrations of imide carbonyl were confirmed in the IR spectra of all the films. Thus, it was confirmed that all the obtained films were made of polyimide. Regarding the tetracarboxylic dianhydride, in Examples 4 to 8, the high-temperature-side product (compound containing 100 mol% of BNBDA-A) obtained in Example 2 was used alone. In Comparative Example 3, the compound containing 100 mol% of BNBDA-B obtained in Comparative Example 1 was used alone. In Comparative Examples 4 to 5, the compounds containing 100 mol% of BNBDA-C obtained in Comparative Example 2 were used alone, respectively. Further, in Examples 7 and 8 regarding the diamine compounds, a mixture of the two compounds described in Table 1 was used. Also, "DMAc" in the solvents described in Table 1 indicates N,N-dimethylacetamide. Further, regarding Examples 4 to 8 and Comparative Examples 3 to 5, the intrinsic viscosity [η] of the polyamic acid obtained in the polyamic acid preparation process was also measured in the same manner as in Example 3. The measurement results are shown in Table 1.

[0212] (Example 9) 〈Polyimide varnish preparation process〉 First, the low-temperature-side product and the high-temperature-side product obtained in Example 2 were used, and they were mixed so that the molar ratio of BNBDA-A to BNBDA-B (BNBDA-A / BNBDA-B) was 3 / 7, and 1.65 g (5.00 mmol) of a tetracarboxylic dianhydride with a molar ratio of BNBDA-A to BNBDA-B of 3 / 7 was prepared.

[0213] Next, in a nitrogen atmosphere, in a 50 mL flask, TFMB (1.60 g, 5.00 mmol) as a diamine compound and a tetracarboxylic dianhydride (1.65 g, 5.00 mmol) with a molar ratio of BNBDA-A to BNBDA-B of 3 / 7 were introduced. Next, DMAc (6.5 g) as a solvent, γ-butyrolactone (6.5 g) as a solvent, and triethylamine (25.3 mg) as a reaction accelerator were added to the flask to obtain a mixed solution. Next, the obtained mixed solution was stirred at 180 °C for 6 hours in a nitrogen atmosphere to produce polyimide, and a reaction solution containing polyimide (polyimide varnish: PI varnish) was obtained. In addition, except for preparing and using a measurement sample (solution) in which the concentration of PI in DMAc is 0.5 g / dL using a part of the PI varnish thus obtained, the intrinsic viscosity [η] of polyimide was measured in the same manner as the measurement method of the intrinsic viscosity [η] of the aforementioned polyamic acid. As a result, the intrinsic viscosity [η] of polyimide was 0.42 dL / g. Here, "GBL" in the solvents listed in Table 1 indicates γ-butyrolactone.

[0214] <Film Preparation Step Comprising Polyimide> Next, the PI varnish was spin-coated onto a glass plate made of a large slide glass (product name "S9213" manufactured by Matsunami Glass Industry Co., Ltd., vertical: 76 mm, horizontal: 52 mm, thickness: 1.3 mm) to form a coating film of the PI varnish. Thereafter, the glass plate with the coating film formed thereon was put into an oven, the temperature condition was set to 60°C, and it was left standing for 4 hours in a nitrogen atmosphere. Then, the temperature condition was changed to 350°C (final film-forming temperature), and it was left standing at 350°C for 1 hour to cure the coating film, thereby obtaining a polyimide-coated glass in which a thin film (film made of polyimide) made of polyimide was coated on the glass plate. Next, the polyimide-coated glass thus obtained was taken out of the oven and immersed in hot water at 90°C for 0.5 hour, and the film was peeled off from the glass plate and recovered to obtain a film made of polyimide with a film thickness of 20 μm. Regarding the obtained film made of polyimide, when its color was visually confirmed, it was confirmed to be colorless and transparent. When the IR spectrum of the film thus obtained was measured, an absorption peak of the stretching vibration of C=O of imide carbonyl was confirmed in the IR spectrum, and it was confirmed that the obtained film was made of polyimide.

[0215] [Evaluation of the properties of the polyimides obtained in Examples 3 to 9 and Comparative Examples 3 to 5] <Measurement of the 5% weight loss temperature (Td5%)> The 5% weight loss temperature of the polyimide obtained in each example etc. was determined by using a thermogravimetric analyzer ("TG / DTA220" manufactured by SII NanoTechnology Inc.) with the polyimide film produced in each example, flowing nitrogen gas, raising the temperature from room temperature to 40°C, then using 40°C as the start temperature of measurement, heating under a temperature raising condition of 10°C / min, and measuring the temperature at which the weight of the sample used decreased by 5%. The results obtained are shown in Table 1.

[0216] <Measurement of yellowness index (YI)> The yellowness index (YI) of the polyimide obtained in each example etc. was determined by using the polyimide film obtained in each example etc. as a sample for measurement as it was, and using a spectrocolorimeter "SD6000" manufactured by Nippon Denshoku Industries Co., Ltd. as a measuring device, and performing measurement in accordance with ASTM E313-05 (issued in 2005). The results obtained are shown in Table 1.

[0217] <Measurement of Coefficient of Thermal Expansion (CTE) and Glass Transition Temperature (Tg)> The coefficient of thermal expansion (CTE) and glass transition temperature (Tg) were measured by forming a film with a size of 20 mm in length and 5 mm in width from the polyimide film obtained in each example etc. (since the thickness of such a film does not affect the measurement value, the thickness of the film obtained in each example etc. was adopted as it was) as a measurement sample, using a thermomechanical analyzer (trade name "TMA8310" manufactured by Rigaku) as a measuring device, and performing measurement under a nitrogen atmosphere, in a tensile mode (49 mN), and at a heating rate of 5 °C / min, and were determined from the obtained TMA curve. The Tg of the polyimide obtained in each example etc. was determined by measuring the temperature at the intersection of the tangents drawn to the curves before and after the inflection point from the TMA curve. Also, the CTE of the polyimide obtained in each example etc. was determined by calculating the average value of the change in length per degree Celsius in the temperature range of 100 °C to 200 °C from the TMA curve. The results obtained are shown in Table 1.

[0218]

Table 1

[0219] As is clear from the results shown in Table 1, when comparing Examples 3 to 4 and Comparative Examples 3 to 4 using BAPP as the diamine compound, when using a tetracarboxylic dianhydride containing 30 mol% or more of BNBDA-A with respect to the total amount of BNBDA-A and BNBDA-B (Examples 3 to 4), compared with the tetracarboxylic dianhydride containing 100 mol% of BNBDA-B (Comparative Example 3) and the tetracarboxylic dianhydride containing 100 mol% of BNBDA-C (Comparative Example 4), it was found that the intrinsic viscosity of the polyamic acid (PAA) was a higher value. Here, considering that Examples 3 to 4 and Comparative Examples 3 to 4 adopted the same conditions except for the type of tetracarboxylic dianhydride, when using a tetracarboxylic dianhydride containing 30 mol% or more of BNBDA-A with respect to the total amount of BNBDA-A and BNBDA-B as a monomer for polyimide production (Examples 3 to 4), compared with the case of using a tetracarboxylic dianhydride containing 100 mol% of BNBDA-B as a monomer for polyimide production (Comparative Example 3) and the case of using a tetracarboxylic dianhydride containing 100 mol% of BNBDA-C as a monomer for polyimide production (Comparative Example 4), it was found that the monomer showed higher polymerization reactivity.

[0220] Also, when comparing Example 5 and Comparative Example 5 using ODA as the diamine compound, when using a tetracarboxylic dianhydride containing 100 mol% of BNBDA-A (Example 5), compared with the tetracarboxylic dianhydride containing 100 mol% of BNBDA-C (Comparative Example 5), it was also found that the intrinsic viscosity of the polyamic acid (PAA) was a higher value. From such results, when using a tetracarboxylic dianhydride containing 100 mol% of BNBDA-A as a monomer for polyimide production (Example 5), compared with the case of using a tetracarboxylic dianhydride containing 100 mol% of BNBDA-C as a monomer for polyimide production (Comparative Example 5), it was found that the monomer showed higher polymerization reactivity.

[0221] Thus, when a tetracarboxylic dianhydride containing 30 mol% or more of BNBDA-A with respect to the total amount of BNBDA-A and BNBDA-B is used as a monomer for producing polyimide, the reason why the intrinsic viscosity of polyamic acid (PAA) becomes a higher value is not necessarily clear. However, from the structure of BNBDA-A and the like, the solubility of the monomer is further improved, the polymerizability is improved, and thus the molecular weight of the resulting polyamic acid becomes higher, and the inventors speculate that a polyamic acid having a higher intrinsic viscosity can be formed.

[0222] Also, when comparing Examples 3 to 4 and Comparative Examples 3 to 4 using BAPP as the diamine compound, the polyimides obtained in Examples 3 to 4 have a higher Td5% value. In the same system of diamine compounds, by using a tetracarboxylic dianhydride containing 30 mol% or more of BNBDA-A with respect to the total amount of BNBDA-A and BNBDA-B, it was confirmed that the heat resistance based on Td5% of the resulting polyimide becomes higher. Further, when comparing Example 5 and Comparative Example 5, the polyimide obtained in Example 5 has a higher Td5% value. In the same system of diamine compounds, when using a tetracarboxylic dianhydride containing 100 mol% of BNBDA-A, it was also confirmed that the heat resistance based on Td5% of the resulting polyimide becomes higher. From the results described in Table 1, all of the polyimides obtained in Examples 3 to 9 have a higher Td5% value compared to the polyimides obtained in Comparative Examples 3 to 5. From such results as well, it can be seen that by using a tetracarboxylic dianhydride containing 30 mol% or more of BNBDA-A with respect to the total amount of BNBDA-A and BNBDA-B, a polyimide showing a higher level of heat resistance can be obtained. From such measurement results of Td5%, it was found that when using a tetracarboxylic dianhydride containing 30 mol% or more of BNBDA-A with respect to the total amount of BNBDA-A and BNBDA-B (Examples 3 to 9), a polyimide having a higher degree of heat resistance can be obtained.

[0223] Thus, when a tetracarboxylic dianhydride containing 30 mol % or more of BNBDA-A relative to the total amount of BNBDA-A and BNBDA-B is used as a monomer for producing a polyimide, the reason why the heat resistance of the resulting polyimide is improved is not necessarily clear. However, the inventors speculate that this is because the molecular skeleton of the polyimide becomes more linear and rigid due to the structure of BNBDA-A in the tetracarboxylic dianhydride, and the polyimide contains a specific amount or more of such a rigid molecular skeleton portion, resulting in higher heat resistance based on Td5%.

[0224] As shown in Table 1, all of the polyimides of the present invention have a Tg of 333° C. or higher, and from this viewpoint, they are also found to have high heat resistance. In addition, all of the polyimides of the present invention have a CTE of 60 ppm / K or lower, and are also found to have excellent dimensional stability. [Industrial Applicability]

[0225] As described above, according to the present invention, it is possible to provide a tetracarboxylic dianhydride that can be used as a raw material monomer for producing a polyimide having a higher level of heat resistance and that can further improve the polymerization reactivity when used as a raw material monomer for producing a polyimide, a carbonyl compound that can be used to efficiently produce the tetracarboxylic dianhydride, a polyimide that can have a higher level of heat resistance, and a polyimide precursor resin that can be suitably used to produce the polyimide. The polyimide of the present invention is useful as a material for producing polyimide products to be used in the various applications described above (for example, films for flexible wiring boards, etc.).

Claims

1. A tetracarboxylic dianhydride comprising an acid dianhydride (A) having an exo / exo-type steric structure represented by the following general formula (1): 【Chemical 1】 [In formula (1), R １ each independently represents one selected from the group consisting of a hydrogen atom and a methyl group, R ２ and R ３ each independently represents one selected from the group consisting of a hydrogen atom and a methyl group. or a tetracarboxylic dianhydride comprising at least one acid dianhydride (B) selected from the group consisting of the acid dianhydride (A) and a compound having an endo / exo-type steric structure represented by the following general formula (2) and a compound having an exo / endo-type steric structure which is an enantiomer thereof, and [Chemical 2] [In formula (2), R １ , R ２ and R ３ are synonymous with R １ , R ２ and R ３ in the above formula (1), respectively.] the content of the acid dianhydride (A) relative to the total amount of the acid dianhydrides (A) and (B) is 30 to 100 mol% in molar ratio. A tetracarboxylic dianhydride characterized by the above.

2. A carbonyl compound comprising a carbonyl compound (A) having an exo / exo-type steric structure represented by the following general formula (3): or a carbonyl compound comprising at least one carbonyl compound (B) selected from the group consisting of the carbonyl compound (A) and a compound having an endo / exo-type steric structure represented by the following general formula (4) and a compound having an exo / endo-type steric structure which is an enantiomer thereof, and 【Chemical Formula 3】 [In formula (3), R １ each independently represents one selected from the group consisting of a hydrogen atom and a methyl group, R ２ and R ３ each independently represents one selected from the group consisting of a hydrogen atom and a methyl group, R ４ each independently represents one selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms, and an aralkyl group having 7 to 20 carbon atoms.] the content of the carbonyl compound (A) relative to the total amount of the carbonyl compounds (A) and (B) is 30 to 100 mol% in molar ratio. A carbonyl compound characterized by the above. 【Chemical Formula 4】 [In formula (4), R １ , R ２ , R ３ and R ４ are respectively synonymous with R １ , R ２ , R ３ and R ４ in the above formula (3).]

3. A polyimide containing a repeating unit (A) having an exo / exo-type steric structure represented by the following general formula (5): or a polyimide containing at least one repeating unit (B) selected from the group consisting of the repeating unit (A) and a structural unit having an endo / exo-type steric structure represented by the following general formula (6) and a structural unit having an exo / endo-type steric structure which is an enantiomer thereof, and the content of the repeating unit (A) relative to the total amount of the repeating units (A) and (B) is 30 to 100 mol% in molar ratio. A polyimide characterized by the above. [Chemical Formula 5] [In formula (5), R １ each independently represents one selected from the group consisting of a hydrogen atom and a methyl group, R ２ and R ３ each independently represents one selected from the group consisting of a hydrogen atom and a methyl group, R ５ represents an arylene group having 6 to 50 carbon atoms.

4. 【Chemical Formula 6】 [In formula (6), R １ , R ２ , R ３ and R ５ are respectively synonymous with R １ , R ２ , R ３ and R ５ in the above formula (5).] The following general formula (7): ​ ​ ​ [Chemical Formula 7] [In formula (7), R １ each independently represents one selected from the group consisting of a hydrogen atom and a methyl group, R ２ and R ３ each independently represents one selected from the group consisting of a hydrogen atom and a methyl group, R ５ represents an arylene group having 6 to 50 carbon atoms, Y １ each independently represents one selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, and an alkylsilyl group having 3 to 9 carbon atoms, One of the bonds represented by *1 and the bond represented by *2 is bonded to the carbon atom a forming the norbornane ring, and the other of the bond represented by *1 and the bond represented by *2 is bonded to the carbon atom b forming the norbornane ring. One of the bonds represented by *3 and the bond represented by *4 is bonded to the carbon atom c forming the norbornane ring, and the other of the bond represented by *3 and the bond represented by *4 is bonded to the carbon atom d forming the norbornane ring.] A polyimide precursor resin containing a repeating unit (A') having an exo / exo-type steric structure represented by, or the repeating unit (A') and the following general formula (8): 【Chemical Formula 8】 [In formula (8), R １ , R ２ , R ３ , R ５ , Y １ , a to d and *1 to *4 are respectively R １ , R ２ , R ３ , R ５ , Y １ , a to d and *1 to *4 in the above formula (7) and have the same meanings.] A polyimide precursor resin containing at least one repeating unit (B') selected from the group consisting of a structural unit having an endo / exo-type steric structure represented by and a structural unit having an exo / endo-type steric structure which is a mirror image thereof, and A polyimide precursor resin characterized in that the content of the repeating unit (A') relative to the total amount of the repeating units (A') and (B') is 30 to 100 mol% in terms of molar ratio.

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