JP5790386B2 - Method for producing norbornane skeleton-containing polyamide - Google Patents

Description

  The present invention relates to a method for producing a norbornane skeleton-containing polyamide.

  Conventionally, an epoxy resin has been widely used as a resin for an optical member used for an optoelectronic device or the like because of a mounting process on an electronic substrate or the like, heat resistance under high temperature operation, mechanical characteristics, or versatility. However, in recent years, the use of high-intensity laser light, blue light, and near-ultraviolet light has expanded in the field of optoelectronic devices, and a resin that is superior in transparency, heat resistance, and light resistance than ever has been required.

  In general, epoxy resins have high transparency under visible light, but sufficient transparency cannot be obtained in the ultraviolet to near ultraviolet region. Further, a cured product composed of an alicyclic epoxy resin and an acid anhydride has a relatively high transparency in the near-ultraviolet region, but has a problem that it is easily colored by heat or light. Moreover, the improvement of heat resistance and ultraviolet coloring resistance is calculated | required, and various epoxy resins are examined (for example, refer patent documents 1-4).

  On the other hand, heat-resistant resins such as polyamide are excellent in heat resistance, insulation, light resistance and mechanical properties, and are therefore widely used in the field of electronics as surface protection films and interlayer insulation films for semiconductor elements. Among them, polymers having an alicyclic structure are beginning to be examined as materials for optoelectronic devices and various displays because of their excellent transparency in the ultraviolet region. As such raw material monomers, dicarboxylic acids having a norbornane skeleton or derivatives thereof are actively used (see, for example, Patent Documents 5 to 8).

  By the way, in general, dimethyl norbornane dicarboxylate, which is a dicarboxylic acid derivative having a norbornane skeleton, is subjected to Diels-Alder reaction of cyclopentadiene and acrylate ester to form norbornene monocarboxylic acid ester, and then to the unsaturated bond portion. Although it can be obtained by adding a carboxylic acid ester, in the Diels-Alder reaction, an exo / endo mixture having a high endo-isomer ratio is obtained (see, for example, Patent Document 9). On the other hand, it is known that a norbornane derivative having a polar functional group at the end position reduces the polymerization activity of the catalyst (see, for example, Patent Document 10).

JP 2007-308683 A JP 2006-131867 A JP 2003-171439 A JP 2004-75894 A Japanese Patent No. 3091784 Japanese Patent No. 3331121 Japanese Patent No. 3795234 Japanese Patent No. 4384636 Japanese Patent Application No. 2007-261980 JP 2003-128766 A

  The present inventors have found that a polymer obtained using a norbornane derivative having a polar functional group at the end position has low heat resistance and the like.

  In contrast, a norbornane skeleton-containing polyamide having a high exo-form ratio has a structure with high crystallinity, and therefore can be expected to be a polymer having excellent heat resistance and thermal conductivity. Accordingly, an object of the present invention is to provide a norbornane skeleton-containing polyamide having a high exo ratio.

  As a result of diligent research to solve the above object, the present inventors have found that a norbornane skeleton-containing polyamide having a high exo isomer ratio is excellent in heat resistance and the like. The invention has been completed.

  That is, the present invention is as follows.

<1> norbornane dicarboxylic acid represented by the following formula (I);
A diisocyanate compound represented by the following general formula (II):
(In the formula, X is a divalent organic group.)
A process for producing a norbornane skeleton-containing polyamide in which the reaction is carried out in a polar solvent,
60 mol% or more of the total amount of norbornane dicarboxylic acid is an exo norbornane dicarboxylic acid represented by the following formula (III), and contains 60 mol% or more of an exo skeleton, the following general formula (IV) The manufacturing method of the norbornane frame | skeleton containing polyamide represented by these.

(In the formula, X is a divalent organic group. N is an integer of 1 to 500.)

<2> The method for producing a norbornane skeleton-containing polyamide according to <1>, wherein the diisocyanate compound represented by the general formula (II) is a diisocyanate compound represented by the following general formula (V).

(In the formula, Y is a divalent organic group selected from a divalent aliphatic group having 4 to 16 carbon atoms and a divalent alicyclic group having 4 to 16 carbon atoms.)

<3> The process for producing a norbornane skeleton-containing polyamide according to <1>, wherein the diisocyanate compound represented by the general formula (II) is a diisocyanate compound represented by the following general formula (VI).

(However, in the formula, Z is a divalent aromatic group.)

<4> An exo / endo mixed norbornane dicarboxylic acid containing 60 mol% of an exo norbornane dicarboxylic acid represented by the above formula (III) is obtained by a method including the steps (1) to (2). The method for producing a norbornane skeleton-containing polyamide according to any one of <1> to <3> above.

(1) Step: Norbornadiene represented by the following formula (VII) and formate represented by the following general formula (VIII),
(However, R < ² >, R < ³ > shows a C1-C5 alkyl group, a vinyl group, and a benzyl group. In addition, R < ² >, R < ³ > may be same or different.)
The reaction is carried out in the presence of a catalyst system containing a ruthenium compound, a cobalt compound, a halide salt, and a basic compound, and 60 mol% of an exo norbornane dicarboxylic acid derivative represented by the following general formula (IX) is obtained. It is set as the exo body / endo body mixed norbornane dicarboxylic acid derivative containing the above.

(However, in the formula, R ² and R ³ each independently represents an alkyl group having 1 to 5 carbon atoms, a vinyl group, or a benzyl group. Note that R ² and R ³ may be the same or different. Good.)

(2) Step: Hydrolyzing the alkoxycarbonyl group of the exo / endo mixed norbornane dicarboxylic acid derivative containing 60 mol% or more of the exo norbornane dicarboxylic acid derivative represented by the general formula (IX), An exo / endo mixed norbornane dicarboxylic acid containing 60 mol% or more of the exo norbornane dicarboxylic acid represented by III) is obtained.

<5> Production of norbornane skeleton-containing polyamide according to any one of <1> to <4>, wherein the ruthenium compound is a ruthenium complex having both a carbonyl ligand and a halogen ligand in the molecule. Method.

<6> The method for producing a norbornane skeleton-containing polyamide according to any one of <1> to <5>, wherein the halide salt is a quaternary ammonium salt.

<7> The method for producing a norbornane skeleton-containing polyamide according to any one of <1> to <7>, wherein the basic compound is a tertiary amine.

<8> The method for producing a norbornane skeleton-containing polyamide according to any one of <1> to <7>, wherein the catalyst system further contains a phenol compound.

<9> The method for producing a norbornane skeleton-containing polyamide according to any one of <1> to <8>, wherein the catalyst system further contains an organic halogen compound.

  By the production method of the present invention, a norbornane skeleton-containing polyamide having a high exo isomer ratio, specifically, containing 60 mol% or more of an exo skeleton is obtained. The norbornane skeleton-containing polyamide having a high exo-form ratio obtained from the production method of the present invention is excellent in heat resistance, insulation, light resistance and mechanical properties, so it can be used in electronic parts used in semiconductors and liquid crystals, optical fibers, optical lenses, etc. It can be used as a representative optical material, a display-related material, and a medical material.

13C-NMR spectrum of methyl exo-norbornanedicarboxylate obtained in Synthesis Example 1 13C-NMR spectrum of methyl exo-norbornanedicarboxylate obtained in Synthesis Example 1 1H-NMR spectrum of methyl exo-norbornane dicarboxylate obtained in Synthesis Example 1 1H-13C HSQC spectrum of exo-form norbornanedicarboxylate obtained in Synthesis Example 1 1H-1H COSY spectrum of exo-form norbornane dicarboxylate obtained in Synthesis Example 1 1H-13H HMBC spectrum of methyl exo norbornane dicarboxylate obtained in Synthesis Example 1 1H-1H NOESY spectrum of methyl exo norbornane dicarboxylate obtained in Synthesis Example 1 1H-NMR spectrum of the exo-norbornanedicarboxylic acid obtained in Synthesis Example 1 Synthesis Example 1 1H-NMR spectrum of methyl endo norbornane dicarboxylate obtained 13C-NMR spectrum of methyl endo norbornanedicarboxylate obtained in Synthesis Example 1 1H-13C HSQC spectrum of methyl endo norbornane dicarboxylate obtained in Synthesis Example 1 1H-1H COSY spectrum of methyl endo norbornane dicarboxylate obtained in Synthesis Example 1 1H-13H HMBC spectrum of methyl endo norbornanedicarboxylate obtained in Synthesis Example 1

  Hereinafter, the present invention will be described in more detail.

<1> Method for producing norbornane skeleton-containing polyamide of the present invention The present invention comprises a norbornane dicarboxylic acid represented by the following formula (I):
A diisocyanate compound represented by the following general formula (II):
(In the formula, X is a divalent organic group.)
A process for producing a norbornane skeleton-containing polyamide in which the reaction is carried out in a polar solvent,
60 mol% or more of the total amount of norbornane dicarboxylic acid is an exo norbornane dicarboxylic acid represented by the following formula (III), and contains 60 mol% or more of an exo skeleton, the following general formula (IV) It is related with the manufacturing method of the norbornane frame | skeleton containing polyamide represented by these.

(In the formula, X is a divalent organic group.)

  First, the norbornane skeleton-containing polyamide obtained by the production method of the present invention will be described below.

<Norbornane skeleton-containing polyamide obtained by the production method of the present invention>
The norbornane skeleton-containing polyamide obtained by the production method of the present invention is a norbornane skeleton-containing polyamide having a high exo isomer ratio and containing 60 mol% or more of the skeleton represented by the following general formula (IVa).

(In the formula, X is a divalent organic group. N is an integer of 1 to 500.)

X in the above formula is the same as X in the diisocyanate compound represented by the general formula (II) described later.
Moreover, n in the said formula is 1-500.

The norbornane skeleton-containing polyamide obtained by the production method of the present invention preferably has a number average molecular weight of 2,000 to 200,000, more preferably 3,000 to 180,000. When the number average molecular weight is less than 2,000, heat resistance and the like tend to decrease, and when it exceeds 200,000, solubility in a solvent tends to decrease.
In order to make the number average molecular weight of the norbornane skeleton-containing polyamide within the above range, it may be produced by the production method of the present invention.

The number average molecular weight is measured under the following conditions using gel permeation chromatography (hereinafter abbreviated as “GPC”), and is calculated using a calibration curve based on standard polystyrene.
Apparatus: Hitachi, Ltd., L6000 type Column: Showa Denko Co., Ltd., Shodex KD-806M × 1 Eluent: N-methyl-2-pyrrolidone 1.0 ml / min
Detector: UV (280 nm)

The norbornane skeleton-containing polyamide in the present invention is represented by the following general formula (II), and an exo / endo mixed norbornane dicarboxylic acid containing 60 mol% or more of an exo norbornane dicarboxylic acid represented by the following formula (III): It can be obtained by reacting a diisocyanate compound with a polar solvent.
(In the formula, X is a divalent organic group.)

In the production method of the present invention, by using an exo / endo mixed norbornane dicarboxylic acid containing 60 mol% or more of the exo norbornane dicarboxylic acid represented by the above formula (III) as a raw material, the above general formula (IVa) A norbornane skeleton-containing polyamide having a high exo-form ratio and containing 60 mol% or more of the skeleton represented can be obtained.
In order to determine how much the norbornane skeleton-containing polyamide in the present invention contains the skeleton represented by the above general formula (IVa), GC (gas chromatography) is used.
Specifically, the value obtained by measuring how much the norbornane dicarboxylic acid used for the synthesis of the norbornane skeleton-containing polyamide contains the exo norbornane dicarboxylic acid represented by the above formula (III) is obtained. / The content of endo-forms. However, since dicarboxylic acid cannot be analyzed by GC, the ratio of exo isomer / endo isomer is obtained by measuring carboxylic acid diester by GC.

<Various raw material components used in the production method of the present invention>
Various raw material components in the process for producing the norbornane skeleton-containing polyamide of the present invention will be described below.

(Diisocyanate compound)
In the method for producing a norbornane skeleton-containing polyamide of the present invention, the diisocyanate compound represented by the above general formula (II) to be reacted with the exo / endo mixed norbornane dicarboxylic acid represented by the above formula (I) is specifically Specifically, the diisocyanate compound represented by the following general formula (V) or the following general formula (VI) is mentioned.

(In the formula, Y is a divalent organic group selected from a divalent aliphatic group having 4 to 16 carbon atoms and a divalent alicyclic group having 4 to 16 carbon atoms.)

(However, in the formula, Z is a divalent aromatic group.)

The diisocyanate compound represented by the general formula (V) is not particularly limited, and examples thereof include aliphatic isocyanates such as hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, and lysine diisocyanate (in the general formula (V)). Y is a divalent aliphatic group);
Use cycloaliphatic isocyanates such as isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, cyclohexylene diisocyanate, cyclohexylmethyl isocyanate (in the general formula (V), Y is a divalent alicyclic group); Can do.
These can also be used individually or in mixture of 2 or more types.

The diisocyanate compound represented by the general formula (VI) is not particularly limited. For example, 4,4′-diphenylmethane diisocyanate, tolylene diisocyanate, xylylene diisocyanate, 4,4′-diphenyl ether diisocyanate, 4,4 ′-[ 2,2-bis (4-phenoxyphenyl) propane] diisocyanate, biphenyl-4,4'-diisocyanate, biphenyl-3,3'-diisocyanate, biphenyl-3,4'-diisocyanate, 3,3'-dimethylbiphenyl- 4,4'-diisocyanate, 2,2'-dimethylbiphenyl-4,4'-diisocyanate, 3,3'-diethylbiphenyl-4,4'-diisocyanate, 2,2'-diethylbiphenyl-4,4'- Diisocyanate, 3,3'-dimethoxy Phenyl-4,4'-diisocyanate, 2,2'-dimethoxybiphenyl-4,4'-diisocyanate, naphthalene-1,5-diisocyanate, naphthalene-2,6-diisocyanate, 1,3-phenylene diisocyanate, 4-chloro Aromatic isocyanates such as -6-methyl-1,3-phenylene diisocyanate (in the general formula (VI), Z is a divalent aromatic group); and the like can be used.
These can also be used individually or in mixture of 2 or more types.

  Further, two or more of the aliphatic or alicyclic diisocyanate compound represented by the general formula (V) and the aromatic diisocyanate compound represented by the general formula (VI) can be mixed and used. .

(Polar solvent)
A polar solvent is used for the reaction of the exo / endo mixed norbornane dicarboxylic acid represented by the above formula (I) and the diisocyanate compound represented by the above general formula (II). The polar solvent that can be used is not particularly limited as long as it can dissolve the compound used as a raw material.

Specific examples of polar solvents that can be suitably used include N-methylpyrrolidone, N, N′-dimethylacetamide, N, N′-dimethylformamide, 1,3-dimethyl-3,4,5,6-tetrahydro-2 ( Nitrogen-containing solvents such as 1H) -pyrimidinone;
Ether solvents such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether;
Sulfur-containing solvents such as dimethyl sulfoxide, diethyl sulfoxide, dimethyl sulfone, sulfolane;
Ester solvents such as γ-butyrolactone and cellosolve acetate; ketone solvents such as cyclohexanone and methyl ethyl ketone; and the like can be used.

<Reaction conditions of exo isomer / endo isomer norbornane dicarboxylic acid represented by formula (I) and diisocyanate compound represented by general formula (II)>
In the method for producing a norbornane skeleton-containing polyamide of the present invention, the exo / endo mixed norbornane dicarboxylic acid represented by the above formula (I) and the diisocyanate compound represented by the above general formula (II) are reacted in a polar solvent. The reaction conditions for this are described below.

  The amount of the exo / endo mixed norbornane dicarboxylic acid represented by the above formula (I) and the diisocyanate compound represented by the above general formula (II) is based on the total number of moles of carboxyl groups of the norbornane dicarboxylic acid. The number of moles of isocyanate group is preferably 0.7 to 2.0, more preferably 0.8 to 1.7, still more preferably 0.9 to 1.5, and 0.95. It is especially preferable to set it to -1.3.

  If it is less than 0.7 or exceeds 2.0, it will be difficult to increase the molecular weight of the resulting polyamide, and mechanical properties, heat resistance and the like will tend to be reduced.

  The amount of the polar solvent used is based on 100 parts by mass of the total amount of the exo / endo mixed norbornane dicarboxylic acid represented by the above formula (I) and the diisocyanate compound represented by the above general formula (II). It is preferably 20 to 500 parts by mass, more preferably 30 to 300 parts by mass, and particularly preferably 50 to 200 parts by mass.

  When the amount used is less than 20 parts by mass, the raw materials are not sufficiently dissolved, and the reaction rate tends to be slow. Even when the amount exceeds 500 parts by mass, the yield of the polyamide per batch is reduced, which is particularly advantageous. There is no.

  The reaction temperature is preferably 80 to 200 ° C, more preferably 90 to 190 ° C, and particularly preferably 100 to 180 ° C. The reaction time can be appropriately selected depending on the scale of the batch and the reaction conditions employed.

<Synthesis of exo / endo mixed norbornane dicarboxylic acid represented by formula (I)>
The exo / endo mixed norbornane dicarboxylic acid represented by the above formula (I) used in the production method of the present invention is represented by the above formula (III) in order to obtain a norbornane skeleton-containing polyamide having a high exo isomer ratio. It is important to use an exo isomer / endo isomer mixed norbornane dicarboxylic acid containing 60 mol% or more of exo isomer norbornane dicarboxylic acid (hereinafter also referred to as “exo isomer / endo isomer norbornane dicarboxylic acid having a high exo isomer ratio”).
The exo isomer / endo isomer mixed norbornane dicarboxylic acid having a high exo isomer ratio in the present invention can be obtained by a method including the following steps (1) to (2).

(1) Step: Norbornadiene represented by the following formula (VII) and formate represented by the following general formula (VIII),
(However, R < ² >, R < ³ > shows a C1-C5 alkyl group, a vinyl group, and a benzyl group. In addition, R < ² >, R < ³ > may be same or different.)
The reaction is carried out in the presence of a catalyst system in which a ruthenium compound, a cobalt compound, a halide salt, and a basic compound are combined, and 60 mol of an exo-norbornane dicarboxylic acid derivative represented by the following general formula (IX) is obtained. % Of exo isomer / endo isomer norbornane dicarboxylic acid derivative (hereinafter also referred to as “exo isomer / endo isomer norbornane dicarboxylic acid derivative having a high exo isomer ratio”).

(However, in the formula, R ² and R ³ each independently represents an alkyl group having 1 to 5 carbon atoms, a vinyl group, or a benzyl group. Note that R ² and R ³ may be the same or different. Good.)

(2) Step: Hydrolysis of the alkoxycarbonyl group of the exo / endo mixed norbornane dicarboxylic acid derivative having a high exo isomer ratio yields an exo / endo mixed norbornane dicarboxylic acid having a high exo isomer ratio.

Each step will be described.
(1) Step: Step of obtaining a norbornanedicarboxylic acid derivative represented by the general formula (IX) (also referred to as “hydroesterification reaction”) The above general formula (VIII) reacted with the norbornadiene represented by the above formula (VII) There is no restriction | limiting in particular as formic acid ester represented by these, The following are mentioned.

(Formate ester)
Formate esters usable in the hydroesterification reaction step are appropriately selected from, for example, methyl formate, ethyl formate, propyl formate, isopropyl formate, butyl formate, isobutyl formate, amyl formate, isoamyl formate, vinyl formate, benzyl formate, and the like. Can be used. From the viewpoint of cost and reactivity, linear alkyl formate such as methyl formate and ethyl formate is preferred, and methyl formate is more preferred.

In addition, the ester part (R < ² >, R < ³ >) of formic acid ester respond | corresponds to R < ² >, R < ³ > in the said general formula (IX). R ² and R ³ may be the same or different.

  In order for the norbornane dicarboxylic acid derivative represented by the general formula (IX) to have two types of ester moieties derived from different formic acid esters, the norbornadiene represented by the above formula (VII) and the two formic acid esters are combined together. What is necessary is just to make it react.

(Catalyst system)
For the hydroesterification reaction, a catalyst system that essentially comprises four components of a ruthenium compound, a cobalt compound, a halide salt, and a basic compound is used.
Here, the “catalyst system” includes not only the catalyst itself but also additives, sensitizers, and the like that assist the action of the catalyst.

  As will be clarified by the examples described later, in the present invention, a combination of a ruthenium compound, a cobalt compound, a halide salt, and a basic compound, a desired purpose (norbornane dicarboxylic acid having a high exo-isomer ratio). Ester can be obtained efficiently). Without being bound by theory, the hydroesterification reaction of an unsaturated organic compound according to the present invention reacts with a cobalt compound in which the ruthenium compound cleaves the C—H bond of the formate ester and is added to the unsaturated group of norbornadiene. It is considered that the halide salt and the basic compound promote such a reaction.

  Hereinafter, various compounds of the catalyst system will be specifically described.

(1) Ruthenium compound The ruthenium compound that can be used in the hydroesterification reaction step is not particularly limited as long as it is a compound containing ruthenium. For example, a ruthenium complex compound having a structure in which a ligand is bonded around a ruthenium atom as a center. In one embodiment of the present invention, a ruthenium complex compound having both a carbonyl ligand and a halogen ligand in the molecule is preferable.

Specific examples of such ruthenium complex compounds include [RuCl ₂ (CO) ₃ ] ₂ , [RuCl ₂ (CO) ₂ ] _n , and [Ru (CO) ₃ Cl ₃ ] ⁻ , [Ru ₃ (CO) _11. Cl] ^- and _{[Ru 4 (CO) 13 Cl} ] - and various compounds having as a counter anion. The various compounds having the counter anion may have, for example, a metal ion such as an alkali metal or an alkaline earth metal as the counter cation. Among the exemplified compounds, [Ru (CO) ₃ Cl ₂ ] ₂ and [Ru (CO) ₂ Cl ₂ ] _n are more preferable from the viewpoint of improving the reaction rate.

The ruthenium compound used in the hydroesterification reaction step can be produced according to a method well known in the art, but can also be obtained as a commercial product. [Ru (CO) ₂ Cl ₂ ] _n is M. J. et al. Cleare, W.M. P. Griffith, J. et al. Chem. Soc. (A), 1969, 372. It can be produced according to the method described in 1.

Examples of the ruthenium compound used in the hydroesterification reaction step include RuCl ₃ , Ru ₃ (CO) ₁₂ , RuCl ₂ (C ₈ H ₁₂ ), Ru (CO) ₃ (C ₈ H ₈ ), and Ru (CO) _3. Using the (C ₈ H ₁₂ ) and Ru (C ₈ H ₁₀ ) (C ₈ H ₁₂ ) as precursor compounds, the ruthenium compound is prepared before or during the reaction step of hydroesterification in the present invention. Then, it may be introduced into the reaction system.

  The amount of the ruthenium compound used is preferably as small as possible in view of production costs. However, when the amount of ruthenium used is less than 1/10000 equivalent, the esterification reaction rate tends to be slow. Therefore, the amount of the ruthenium compound used is preferably in the range of 1/10000 to 1 equivalent, more preferably in the range of 1/1000 to 1/10 equivalent, relative to norbornadiene used as the raw material. Ruthenium compounds may be used alone or in combination.

(2) Cobalt compound The cobalt compound that can be used in the hydroesterification reaction step is not particularly limited as long as it is a compound containing cobalt. Specific examples of suitable compounds include cobalt complex compounds having a carbonyl ligand such as Co ₂ (CO) ₈ , HCo (CO) ₄ , and Co ₄ (CO) ₁₂ , cobalt acetate, cobalt propionate, cobalt benzoate, Examples include cobalt complex compounds having a carboxylic acid compound such as cobalt citrate as a ligand, and cobalt phosphate. Among these, from the viewpoint of improving the reaction rate, a cobalt complex compound having a carbonyl ligand is preferable.

  The amount of the cobalt compound used is 1/100 to 10 equivalents, preferably 1/10 to 5 equivalents, relative to the ruthenium compound. Even if the ratio of the cobalt compound to the ruthenium compound is lower than 1/100 equivalents or higher than 10 equivalents, the production amount of the exo / endo mixed norbornane dicarboxylic acid compound having a high exo isomer ratio decreases. Or they tend not to be generated. A cobalt compound may be used independently or may be used in combination.

(3) Halide salt The halide salt that can be used in the hydroesterification reaction step is not particularly limited as long as it is a compound composed of a halide ion such as chloride ion, bromide ion and iodide ion, and a cation. Not. The cation may be either an inorganic ion or an organic ion. The halide salt may contain one or more halogen ions in the molecule.

  The inorganic ion constituting the halide salt may be one metal ion selected from alkali metals and alkaline earth metals. Specific examples include ions of lithium, sodium, potassium, rubidium, cesium, calcium, strontium and the like.

  The organic ion may be a monovalent or higher organic group derived from an organic compound. Examples include ions such as ammonium, phosphonium, pyrrolidinium, pyridium, imidazolium and iminium, and the hydrogen atom of these ions may be substituted by a hydrocarbon group such as alkyl and aryl. Although not particularly limited, specific examples of suitable organic ions include tetramethylammonium, tetraethylammonium, tetrapropylammonium, tetrabutylammonium, tetrapentylammonium, tetrahexylammonium, tetraheptylammonium, tetraoctylammonium, and trioctyl. Examples include ions such as methylammonium, benzyltrimethylammonium, benzyltriethylammonium, benzyltributylammonium, tetramethylphosphonium, tetraethylphosphonium, tetraphenylphosphonium, benzyltriphenylphosphonium, bis (triphenylphosphine) iminium. Of these, quaternary ammonium salts such as butylmethylpyrrolidinium chloride, bis (triphenylphosphine) iminium iodide, trioctylmethylammonium chloride, and tetraethylammonium chloride are more preferable from the viewpoint of improving the reaction rate.

  The halide salt used in the hydroesterification reaction step does not need to be a solid salt, and an ionic liquid containing halide ions that becomes liquid near room temperature or in a temperature range of 100 ° C. or less may be used. Specific examples of cations used for such ionic liquids include 1-ethyl 3-methylimidazolium, 1-propyl-3-methylimidazolium, 1-butyl-3-methylimidazolium, 1-pentyl-3- Methylimidazolium, 1-hexyl-3-methylimidazolium, 1-heptyl-3-methylimidazolium, 1-octyl-3-methylimidazolium, 1-decyl-3-methylimidazolium, 1-dodecyl-3- Methylimidazolium, 1-tetradecyl-3-methylimidazolium, 1-hexadecyl-3-methylimidazolium, 1-octadecyl-3-methylimidazolium, 1-ethyl-2,3-dimethylimidazolium, 1-butyl- 2,3-dimethylimidazolium, 1-hexyl-2,3-dimethylimidazole 1-ethylpyridinium, 1-butylpyridinium, 1-hexylpyridinium, 8-methyl-1,8-diazabicyclo [5.4.0] -7-undecene, 8-ethyl-1,8-diazabicyclo [ 5.4.0] -7-undecene, 8-propyl-1,8-diazabicyclo [5.4.0] -7-undecene, 8-butyl-1,8-diazabicyclo [5.4.0] -7 -Undecene, 8-pentyl-1,8-diazabicyclo [5.4.0] -7-undecene, 8-hexyl-1,8-diazabicyclo [5.4.0] -7-undecene, 8-heptyl-1 , 8-diazabicyclo [5.4.0] -7-undecene, 8-octyl-1,8-diazabicyclo [5.4.0] -7-undecene and the like.

  Among the halide salts described above, preferred halide salts are chloride salts, bromide salts, and iodide salts, and compounds in which the cation is an organic ion. Although not particularly limited, specific examples of the halide salt suitable in the present invention include butylmethylpyrrolidinium chloride, bis (triphenylphosphine) iminium iodide, and trioctylmethylammonium chloride.

  The added amount of the halide salt is, for example, 1 to 1000 equivalents, preferably 2 to 50 equivalents, relative to the ruthenium compound. By making the addition amount 1 equivalent or more, the reaction rate can be effectively increased. On the other hand, when the addition amount exceeds 1000 equivalents, even if the addition amount is further increased, there is a tendency that a further improvement effect of reaction promotion cannot be obtained. In the present invention, halide salts may be used alone or in combination.

(4) Basic compound In the hydroesterification reaction step, the usable basic compound may be an inorganic compound or an organic compound. Specific examples of the basic inorganic compound include carbonates, hydrogen carbonates, hydroxide salts, and alkoxides of various metals such as alkali metals and alkaline earth metals. Specific examples of basic organic compounds include primary amine compounds, secondary amine compounds, tertiary amine compounds, pyridine compounds, imidazole compounds, and quinoline compounds.

  Among the above basic compounds, a tertiary amine compound is preferable from the viewpoint of the reaction promoting effect. Specific examples of the tertiary amine compound suitable in the present invention include trialkylamine, N-alkylpyrrolidine, N-alkylpiperidine, quinuclidine, and triethylenediamine.

  Although the addition amount of a basic compound is not specifically limited, For example, it is 1-1000 equivalent with respect to a ruthenium compound, Preferably it is 2-200 equivalent. By making the addition amount 1 equivalent or more, the expression of the promoting effect tends to become more prominent. Moreover, when the addition amount exceeds 1000 equivalents, even if the addition amount is further increased, there is a tendency that a further improvement effect of reaction promotion cannot be obtained.

(5) Other components of catalyst system In the hydroesterification reaction step, a specific catalyst system containing a ruthenium compound, a cobalt compound, a halide salt, and a basic compound, if necessary, a phenol compound or an organic halogen compound It is possible to further enhance the effect of promoting the reaction by the catalyst system.
Hereinafter, various compounds will be described.

(5-1) Phenol compounds Specific examples of suitable phenol compounds used in the hydroesterification reaction include phenol, cresol, alkylphenol, methoxyphenol, phenoxyphenol, chlorophenol, trifluoromethylphenol, hydroquinone and catechol.

  The addition amount of a phenol compound is 1-1000 equivalent with respect to a ruthenium compound, Preferably it is 2-50 equivalent. By making the addition amount 1 equivalent or more, the expression of the promoting effect tends to become more prominent. Moreover, when the addition amount exceeds 1000 equivalents, even if the addition amount is further increased, there is a tendency that a further improvement effect of reaction promotion cannot be obtained.

(5-2) Organic Halogen Compound Suitable organic halogen compounds in the hydroesterification reaction step include methyl halide, dihalogen methane, dihalogen ethane, trihalogen methane, tetrahalogen carbon, halogenated benzene and the like.

  The amount of the organic halogen compound added is, for example, 1 to 1000 equivalents, preferably 2 to 50 equivalents, relative to the ruthenium compound. By making the addition amount 1 equivalent or more, the expression of the promoting effect tends to become remarkable. Moreover, when the addition amount exceeds 1000 equivalents, even if the addition amount is further increased, there is a tendency that a further improvement effect of reaction promotion cannot be obtained.

(solvent)
In the hydroesterification reaction, the reaction between norbornadiene represented by the above formula (VII) and formate represented by the above general formula (VIII) can proceed without using any solvent. However, if necessary, a solvent may be used. The solvent that can be used in the present invention is not particularly limited as long as it can dissolve the compound used as a raw material. Specific examples of solvents that can be suitably used in the present invention include n-pentane, n-hexane, n-heptane, cyclohexane, benzene, toluene, o-xylene, p-xylene, m-xylene, ethylbenzene, cumene, tetrahydrofuran, N -Methylpyrrolidone, dimethylformamide, dimethylacetamide, dimethylimidazolidinone, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, acetonitrile and the like.

(Ratio of each raw material)
The ratio of the norbornadiene represented by the above formula (VII) and the formic acid ester represented by the above general formula (VIII) used in the reaction is the amount charged, relative to 1 mol of norbornadiene represented by the above formula (VII). The formic acid ester represented by the general formula (VIII) is preferably 2 to 100 mol, more preferably 4 to 50. When the amount is less than 2 mol, side reactions tend to increase and the number rate tends to decrease. When the amount exceeds 100 mol, only the productivity is lowered and there is no particular effect.

(Reaction temperature)
In the hydroesterification reaction step, the reaction of norbornadiene represented by the above formula (VII) with the formate represented by the above general formula (VIII) is preferably carried out in a temperature range of 80 ° C to 200 ° C. The reaction is more preferably performed at a temperature range of 100 ° C to 160 ° C. By carrying out the reaction at a temperature of 80 ° C. or higher, the reaction rate is increased and the reaction can proceed efficiently. On the other hand, by controlling the reaction temperature to 200 ° C. or lower, decomposition of the formate used as a raw material can be suppressed. When the formate is decomposed, addition of the ester group to norbornadiene cannot be achieved. Furthermore, if the reaction temperature is too high, ring-opening polymerization of norbornadiene, which is a raw material, may occur and the yield may be lowered. Therefore, a reaction temperature that is too high is undesirable.

  When the reaction temperature exceeds the boiling point of either norbornadiene or formate used as a raw material, it is necessary to carry out the reaction in a pressure resistant vessel. The completion of the reaction can be confirmed using a well-known analytical technique such as gas chromatography or NMR.

  The exo / endo mixed norbornane dicarboxylic acid derivative obtained in the step (1) as shown above and having a high exo-isomer ratio is isolated by distillation or the like, if necessary, and the raw material for the hydrolysis step in the following (2) It can be.

(2) Step: Hydrolysis step of exo / endo mixed norbornane dicarboxylic acid derivative containing 60 mol% of exo norbornane dicarboxylic acid derivative represented by the above general formula (IX) In the production method of the present invention, exo compound ratio The exo isomer / endo isomer mixed norbornane dicarboxylic acid having a high exo isomer ratio used to obtain a polyamide having a high norbornane skeleton is obtained by the exo isomer / endo isomer norbornane having a high exo isomer ratio obtained in the step (1). Obtained by hydrolyzing the alkoxycarbonyl group of the dicarboxylic acid derivative.

  There is no particular limitation on the method of hydrolyzing the alkoxycarbonyl group of the exo / endo mixed norbornane dicarboxylic acid derivative having a high exo isomer ratio to obtain an exo / endo mixed norbornane dicarboxylic acid having a high exo isomer ratio. For example, acid hydrolysis, alkali hydrolysis, etc. described in Japanese Patent No. 2591492 or JP-A-2008-31406 can be used. Alternatively, it can be hydrolyzed by heating at a high temperature of 140 ° C. or higher in the presence of moisture in a heat-resistant container without adding an acid component or an alkali component.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the scope of the present invention is not limited by the following examples.

<1> Synthesis of norbornane dicarboxylic acid (Synthesis Example 1)
<Synthesis of exo / endo mixed norbornane dicarboxylic acid containing 60 mol% or more of exo norbornane dicarboxylic acid represented by formula (III)>
[Synthesis of dimethyl norbornane dicarboxylate: synthesis of exo / endo mixed norbornane dicarboxylic acid derivative containing 60 mol% or more of exo norbornane dicarboxylic acid derivative represented by general formula (IX) (in general formula (IX), R ² , R ³ = methyl group)]

In a stainless steel pressure reactor having an internal volume of 50 ml at room temperature, 0.05 mmol of [Ru (CO) ₃ Cl ₂ ] ₂ as a ruthenium compound, 0.05 mmol of Co ₂ (CO) ₈ as a cobalt compound, halide A catalyst system was obtained by adding 0.25 mmol of butylmethylpyrrolidinium chloride as a salt and 1.0 mmol of triethylamine as a basic compound and mixing them. To this catalyst system, 2.5 mmol of norbornadiene and 5.0 mL of methyl formate were added, and then the inside of the reactor was purged with nitrogen gas at 0.5 MPa and maintained at 120 ° C. for 15 hours.
Thereafter, the reaction apparatus was cooled to room temperature, released, a part of the remaining organic phase was extracted, and the components of the reaction mixture were analyzed using a gas chromatograph.

  According to the analysis results, methyl norbornane dicarboxylate produced by the reaction was 1.63 mmol (yield 65.2% based on methyl norbornane dicarboxylate), and the composition ratio (molar ratio) of exo / endo was 75 / 25. At this time, since there were two gas chromatographic peaks for both the exo and endo isomers, it was presumed to be 2,5-isomer and 2,6-isomer.

In addition, the gas chromatograph analysis was performed on the following conditions using GC-353B type GC by GL Sciences.
Detector: Hydrogen flame ion detector Column: TC-1 manufactured by GL Sciences (length: 60 m)
Carrier gas: helium (300 kPa)
Temperature inlet: 200 ° C
Detector: 200 ° C
Column: 40 ° C. to 240 ° C. (heating rate: 5 ° C./min)

  Further, the exo form / endo form (two peaks of gas chromatograph) were separated by distillation under reduced pressure to obtain an exo form and an end form, respectively.

The 13C-NMR spectrum of methyl exo-norbornanedicarboxylate obtained by separation under reduced pressure distillation is shown in FIGS. The measurement conditions and identification data of the 13C-NMR spectrum shown in FIGS. 1 and 2 are as follows.
Conditions: Solvent DMSO-d6, apparatus “AV400M” manufactured by BRUKER (carbon fundamental frequency: 100.62 MHz).

  As a result of 13C-NMR analysis, carbon of carbonyl was observed near 170 to 180 ppm, carbon of methyl ester was observed near 51 to 52 ppm, carbon of methylene was observed near 39 to 45 ppm, and carbon of methine was observed near 32 to 36 ppm. The number was carbonyl / methyl ester / methylene / methine = 2/2/4/5. Each carbon was assigned as shown below.

The sign of each carbon in the following sentence corresponds to a circle number indicating the position of carbon in the above chemical formula.
Carbon (1): peak at 39.89 ppm (methine)
Carbon (2): Peak of 44.59 ppm (methine)
Carbon (3): 33.03 ppm peak (methylene)
Carbon (4): peak at 39.89 ppm (methine)
Carbon (5): 44.59 ppm peak (methine)
Carbon (6): 33.02 ppm peak (methylene)
Carbon (7): 34.35 ppm peak (methylene)
Carbon (8): 51.44 ppm peak (methyl ester)
Carbon (9): 175.22 ppm peak (carbonyl)
Carbon (11): 35.15 ppm peak (methine)
Carbon (12): Peak at 44.77 ppm (methine)
Carbon (13): 32.68 ppm peak (methylene)
Carbon (14): peak at 43.86 ppm (methine)
Carbon (15): 32.68 ppm peak (methylene)
Carbon (16): Peak at 44.77 ppm (methine)
Carbon (17): 34.47 ppm peak (methylene)
Carbon (18): 51.51 ppm peak (methyl ester)
Carbon (19): peak at 174.85 ppm (carbonyl)

  FIG. 3 shows the 1H-NMR spectrum of the resulting methyl exo-norbornane dicarboxylate. The measurement conditions and identification data of the 1H-NMR spectrum shown in FIG. 3 are as follows.

Conditions: Solvent DMSO-d6, apparatus “AV400M” manufactured by BRUKER (proton fundamental frequency: 400.13 MHz).
As a result of 1H-NMR analysis, each proton was assigned as shown below.

The sign of each carbon in the following sentence corresponds to a circle number indicating the position of carbon in the above chemical formula.
Proton (1): peak around 2.47 ppm (methine)
Proton (2): Peak around 2.4 ppm (methine)
Proton (3): peak around 1.5 ppm to 1.8 ppm (methylene)
Proton (4): peak around 2.47 ppm (methine)
Proton (5): peak around 2.4 ppm (methine)
Proton (6): peak around 1.5 ppm to 1.8 ppm (methylene)
Proton (7): Peak around 1.3 ppm (methylene)
Proton (8): Peak around 3.6 ppm (methyl)
Proton (9): Peak around 2.3 ppm (methine)
Proton (12): Peak around 2.5 ppm (methine)
Proton (13): peak around 1.5 ppm to 1.8 ppm (methylene)
Proton (14): peak around 2.7 ppm (methine)
Proton (15): peak around 1.5 ppm to 1.8 ppm (methylene)
Proton (16): Peak around 2.5 ppm (methine)
Proton (17): Peak near 1.2 ppm (methylene)
Proton (18): peak around 3.6 ppm (methyl)

  From the integrated intensity ratio, it was found that there were 4 methyl groups, 6 methylene groups, and 8 methine groups.

  FIG. 4 shows a 1H-13C HSQC spectrum of the obtained methyl exo-form norbornane dicarboxylate. From the 1H-13C HSQC spectrum shown in FIG. 4, it was found that carbon and proton having the same peak number correlated with each other, and the assignment results in FIGS. 1, 2, and 3 were correct.

  FIG. 5 shows the 1H-1H COSY spectrum of the resulting methyl exo-form norbornane dicarboxylate.

  From FIG. 5, proton (1) (4) and proton (7), proton (1) (4) and proton (3) (6), proton (2) (5) and proton (3) (6), proton (11) (14) and proton (17), proton (12) (16) and proton (13) (15) Proton (13) (15) and proton (14) were correlated, respectively. ) To (7) and (11) to (17) were confirmed to constitute a norbornane ring.

  FIG. 6 shows the 1H-13H HMBC spectrum of the resulting methyl exo-norbornane dicarboxylate. Two types of compounds were identified by 1H-13H HMBC spectrum.

(1) Compounds in which the norbornane ring is composed of protons (1) to (7)

  From FIG. 6, since the correlation was recognized by carbonyl carbon (9), methine proton (2), and methine proton (5), it was confirmed that it was methyl norbornane-2,5-dicarboxylate.

(2) Compounds in which the norbornane ring is composed of protons (11) to (17)

  From FIG. 6, it was confirmed that carbonyl carbon (19), methine proton (12), and methine proton (16) were methyl norbornane-2,6-dicarboxylate.

  FIG. 7 shows the 1H-1H NOESY spectrum of the obtained methyl exo-form norbornane dicarboxylate. From the 1H-1H NOESY spectrum, three-dimensional structure identification of methyl norbornane-2,5-dicarboxylate and methyl norbornane-2,6-dicarboxylate was performed.

(1) Methyl norbornane-2,5-dicarboxylate From FIG. 7, there is a correlation between proton (1) (4) and proton (7), but no correlation with proton (2) (5). Thus, it can be seen that protons (2) and (5) are bonded to the end positions. Therefore, this compound was confirmed to be methyl norbornane-2 (exo) -5 (exo) -dicarboxylate.

(2) Methyl norbornane-2,6-dicarboxylate From FIG. 7, protons (11) and (14) have a correlation with proton (17) but no correlation with protons (12) and (16). Thus, it can be seen that protons (12) and (16) are bonded to the end positions. Therefore, this compound was confirmed to be methyl norbornane-2 (exo) -6 (exo) -dicarboxylate.

[Synthesis of norbornene dicarboxylic acid: Synthesis of exo / endo mixed norbornane dicarboxylic acid containing 60 mol% or more of exo norbornane dicarboxylic acid represented by formula (III)]
In a 1-liter eggplant-shaped flask equipped with a cooling tube, 30 g of dimethyl norbornane dicarboxylate (composition ratio of exo-form / endo-form (molar ratio): 75/25) obtained from [dimethyl norbornane dicarboxylate] and 200 g of methanol were added. After making it into a homogeneous solution, 200 g of 10% sodium hydroxide solution was added, put into an oil bath at 100 ° C., and heated to reflux for 6 hours. Thereafter, methanol was distilled off until the amount of the reaction solution reached 140 g, and 48 ml of 36% hydrochloric acid was added thereto to adjust the pH to 1. As a result, a white powder precipitated. This white powder was filtered, washed with water and dried to obtain 25 g of norbornane dicarboxylic acid (NBDA-1).

As a result of analyzing the obtained norbornane dicarboxylic acid by 1H-NMR, the peaks of methylene and methine groups of the norbornane ring are in the vicinity of 1.1 to 3.0 ppm, and the peak of the hydroxyl group due to the carboxylic acid is in the vicinity of 12.4 ppm. The integrated intensity ratio was 10.00 / 1.98 (theoretical value: 10/2). The results of 1H-NMR are shown in FIG.
The composition ratio (molar ratio) of the exo form / endo form of norbornane dicarboxylic acid after hydrolysis is the same as the composition ratio (molar ratio) of the exo form / endo form of norbornane dicarboxylic acid derivative before hydrolysis.

  Next, FIG. 9 shows 1H-NMR of methyl endo norbornanedicarboxylate separated by distillation under reduced pressure. In addition, although the endo-form norbornane dicarboxylate had two peaks as a result of analysis by gas chromatography, the ratio was 95/5 (composition ratio), so it was analyzed as one kind.

  As a result of 1H-NMR analysis, methylene of norbornane ring was observed in the vicinity of 1.3 to 1.7 ppm, methyl ester of norbornane ring was observed in the vicinity of 2.3 to 2.8 ppm, and methyl ester was observed in the vicinity of 3.6 ppm, and methyl norbornane dicarboxylate was observed. It was confirmed that.

  FIG. 10 shows the 13C-NMR spectrum of the resulting methyl methyl endo norbornane dicarboxylate.

  As a result of 13C-NMR analysis, each carbon was assigned as shown below.

The sign of each carbon below corresponds to a circle number indicating the position of carbon in the above chemical formula.
Carbon (1): peak at 39.61 ppm (methine)
Carbon (2): Peak of 44.01 ppm (methine)
Carbon (3): 31.36 ppm peak (methylene)
Carbon (4): peak at 40.63 ppm (methine)
Carbon (5): 45.07 ppm peak (methine)
Carbon (6): 28.94 ppm peak (methylene)
Carbon (7): peak at 37.50 ppm (methylene)
Carbon (8): 51.37 and 51.48 ppm peaks (methyl ester)
Carbon (9): 174.22 and 175.03 ppm peaks (carbonyl)

  FIG. 11 shows the 1H-13C HSQC spectrum of the resulting dimethyl endo norbornane dicarboxylate.

  From FIG. 11, the correlation between each carbon and proton was confirmed, and all protons constituting the endo norbornane dicarboxylate could be assigned, and the obtained dimethyl nor norbornane dicarboxylate was 2,5-isomer. I understood.

  FIG. 12 shows the 1H-1H COSY spectrum of the obtained endo-form norbornanedicarboxylate dimethyl.

  From FIG. 12, the correlation between all adjacent methine group and methylene group protons in protons (1) to (7) is observed, and it can be confirmed that the norbornane ring is composed of protons (1) to (7). It was.

  FIG. 13 shows the 1H-1H NOESY spectrum of the resulting dimethyl norbornanedicarboxylate.

  From FIG. 13, since a correlation is recognized between methine protons (2) and (5) and methylene proton (7), the carboxylic acid methyl groups bonded to the 2nd and 5th positions are both endo forms. confirmed.

(Synthesis Example 2)
<Synthesis of norbornane dicarboxylic acid represented by formula (I)>
[Synthesis of dimethyl norbornane dicarboxylate]
(Formation of cyclopentadiene)

700 g of dicyclopentadiene was charged in a 1 liter flask equipped with a stirrer, a thermometer and a distillation column at the top of the tower, a thermometer and a condenser tube (7 stages), and heated in an oil bath. . When the temperature in the flask reached 158 ° C., cyclopentadiene was distilled from the top of the distillation column, and the receiver was recovered over about 6 hours while cooling with ice. The distillation temperature at this time was 41 to 48 ° C., and the recovered amount was 609 g (recovery rate: 87%).
When the obtained cyclopentadiene was analyzed by gas chromatography, the purity was 100%.

(Synthesis of methyl norbornenecarboxylate)

  Into a 1 liter flask equipped with a stirrer, thermometer, dropping funnel and condenser, 344 g (4.0 mol) of methyl acrylate was charged, and then the above-mentioned (formation of cyclopentadiene) while stirring and cooling the flask with water 265 g (4.0 mol) of cyclopentadiene obtained in (1) was added dropwise with care so that the temperature in the flask was maintained at 30 to 40 ° C. After completion of the dropwise addition, the mixture was reacted for 6 hours while maintaining the reaction temperature, and analyzed by gas chromatography. As a result, methyl acrylate and cyclopentadiene as raw materials disappeared completely, and the selectivity for methyl norbornenecarboxylate was 99.6%. To obtain 0.4% of dicyclopentadiene. The composition ratio (molar ratio) of this methyl norbornenecarboxylate was exo / endo = 25/75.

(Synthesis of methyl norbornane dicarboxylate)

In a stainless steel pressure reactor having an internal volume of 500 ml at room temperature, [Ru (CO) ₃ Cl ₂ ] ₂ is 0.25 mmol as a ruthenium compound, Co ₂ (CO) ₈ is 0.25 mmol as a cobalt compound, halide In a catalyst system in which 5 mmol of trioctylmethylammonium chloride as a salt and 20 mmol of triethylamine as a basic compound were mixed, 100 mmol of methyl norbornenecarboxylate (unpurified) obtained in the above (synthesis of methyl norbornenecarboxylate) and 50 mL of methyl formate After the addition, the reaction vessel was purged with 0.5 MPa of nitrogen gas and held at 120 ° C. for 8 hours. Thereafter, the reaction apparatus was cooled to room temperature, released, and a part of the remaining organic layer was extracted and analyzed using a gas chromatograph.

  According to the analysis results, methyl norbornane dicarboxylate produced by the reaction was 94.3 mmol (yield 94.3% based on methyl norbornane dicarboxylate), and the composition ratio (molar ratio) of exo / endo isomer was 43/57. Met. The obtained methyl norbornane dicarboxylate (exo / endo mixture) was isolated by distillation under reduced pressure.

[Synthesis of norbornene dicarboxylic acid]
In the above Synthesis Example 1 [Synthesis of norbornene dicarboxylic acid], except that the dimethyl norbornane dicarboxylate obtained in the above (synthesis of methyl norbornane dicarboxylate) (composition ratio of exo / endo compound: 43/57) was used. The same operation as [Synthesis of norbornene dicarboxylic acid] in Synthesis Example 1 was performed to obtain 24 g of norbornane dicarboxylic acid (NBDA-2).

(Synthesis Example 3)
[Synthesis of dimethyl norbornane dicarboxylate]

In a stainless steel pressure reactor having an internal volume of 50 ml at room temperature, 0.05 mmol of [Ru (CO) ₃ Cl ₂ ] ₂ as a ruthenium compound, 0.05 mmol of Co ₂ (CO) ₈ as a cobalt compound, halide 0.25 mmol of butylmethylpyrrolidinium chloride as a salt was added and mixed to obtain a catalyst system. To this catalyst system, 2.5 mmol of norbornadiene and 5.0 mL of methyl formate were added, and then the inside of the reactor was purged with nitrogen gas at 0.5 MPa and maintained at 120 ° C. for 15 hours.
Thereafter, the reaction apparatus was cooled to room temperature, released, a part of the remaining organic phase was extracted, and the components of the reaction mixture were analyzed using a gas chromatograph.

  According to the analysis results, the amount of methyl norbornane dicarboxylate produced by the reaction was trace.

<2> Synthesis of norbornane skeleton-containing polyamide (Example 1) [Synthesis of norbornane skeleton-containing polyamide (PA-1) having a high exo-form ratio]
In a 500 ml flask equipped with a stirrer, thermometer, nitrogen introduction tube and cooling tube, 74.20 g (0.350 mol) of norbornane dicarboxylic acid obtained in Synthesis Example 1 and 59.98 g (0.357 mol) of hexamethylene diisocyanate were obtained. (Dicarboxylic acid / diisocyanate (molar ratio) = 1.00 / 1.02) and 202.84 g of N-methylpyrrolidone were heated to 160 ° C. and reacted for 3 hours to give a number average molecular weight of 85,000. A polyamide having a norbornane skeleton (PA-1) was obtained.
In addition, the exo-form ratio of the obtained polyamide is the same as the ratio of norbornane dicarboxylic acid used as a raw material.

The obtained polyamide (PA-1) having a norbornane skeleton was applied onto a Teflon (registered trademark) substrate, heated at 250 ° C., and the organic solvent was dried to form a coating film having a thickness of 30 μm. The glass transition temperature (Tg) and thermal decomposition start temperature (5% mass reduction temperature, Td ₅ ) of this coating film were measured under the following conditions. The results are shown in Table 1.

(1) Glass transition temperature (Tg)
It was measured with a thermomechanical analyzer (Seiko Electronics Co., Ltd., 5200 type TMA).
Measurement mode: Extension measurement span: 10 mm
Load: 10g
Temperature increase rate: 5 ° C / min
Atmosphere: Air

(2) Thermal decomposition start temperature (5% mass reduction temperature, Td ₅ )
It measured with the differential thermal balance (the Seiko Electronics Co., Ltd. make, 5200 type TG-DTA).
Temperature increase rate: 5 ° C / min
Atmosphere: Air

(3) Light transmittance The light transmittance at each wavelength of the obtained polyamide (PA-1) having a norbornane skeleton was measured with a V-570 type UV / VIS spectrophotometer manufactured by JASCO Corporation. . The evaluation results are summarized in Table 1.

(Example 2) [Synthesis of norbornane skeleton-containing polyamide (PA-2) with a high exo-isomer ratio]
In a 500 ml flask equipped with a stirrer, thermometer, nitrogen introduction tube and cooling tube, 53.00 g (0.250 mol) of norbornane dicarboxylic acid obtained in Synthesis Example 1 and 66.81 g of 4,4′-cyclohexylmethane diisocyanate ( 0.255 mol) (dicarboxylic acid / diisocyanate (molar ratio) = 1.00 / 1.02) and 179.72 g of N-methylpyrrolidone were heated to 160 ° C., reacted for 3 hours, and number averaged A polyamide (PA-2) having a norbornane skeleton having a molecular weight of 90,000 was obtained.
The properties of the obtained polyamide (PA-2) having a norbornane skeleton were evaluated in the same manner as in Example 1. The results are summarized in Table 1.

Example 3 [Synthesis of Norbornane Skeleton-Containing Polyamide (PA-3) with High Exo Ratio]
In a 500 ml flask equipped with a stirrer, a thermometer, a nitrogen introduction tube and a cooling tube, 57.24 g (0.270 mol) of norbornane dicarboxylic acid obtained in Synthesis Example 1 and 61.14 (0.275 mol) of isophorone diisocyanate ( Dicarboxylic acid / diisocyanate (molar ratio) = 1.00 / 1.02) and 177.57 g of N-methylpyrrolidone were heated to 160 ° C. and reacted for 3 hours to obtain a number average molecular weight of 85,000. A polyamide (PA-3) having a norbornane skeleton was obtained.
The properties of the obtained polyamide (PA-3) having a norbornane skeleton were evaluated in the same manner as in Example 1. The results are summarized in Table 1.

(Example 4) [Synthesis of norbornane skeleton-containing polyamide (PA-4) having a high exo ratio]
In a 500 ml flask equipped with a stirrer, a thermometer, a nitrogen introduction tube and a cooling tube, 55.12 g (0.260 mol) of norbornane dicarboxylic acid obtained in Synthesis Example 1 and 66.30 g of 4,4′-diphenylmethane diisocyanate (0 .265 mol) (dicarboxylic acid / diisocyanate (molar ratio) = 1.00 / 1.02) and 182.91 g of N-methylpyrrolidone were heated to 160 ° C. and reacted for 3 hours to obtain a number average molecular weight. Obtained polyamide (PA-4) having a norbornane skeleton of 80,000.
The properties of the obtained polyamide (PA-4) having a norbornane skeleton were evaluated in the same manner as in Example 1. The results are summarized in Table 1.

(Comparative Example 1) [Synthesis of norbornane skeleton-containing polyamide (PA-5)]
In a 500 ml flask equipped with a stirrer, thermometer, nitrogen introduction tube and cooling tube, 74.20 g (0.350 mol) of norbornane dicarboxylic acid obtained in Synthesis Example 2 and 59.98 g (0.357 mol) of hexamethylene diisocyanate were obtained. (Dicarboxylic acid / diisocyanate (molar ratio) = 1.00 / 1.02) and 202.84 g of N-methylpyrrolidone were heated to 160 ° C. and reacted for 3 hours to give a number average molecular weight of 45,000. A polyamide having a norbornane skeleton (PA-5) was obtained.
The properties of the obtained polyamide (PA-5) having a norbornane skeleton were evaluated in the same manner as in Example 1. The results are summarized in Table 1.
In addition, the exo-form ratio of the obtained polyamide is the same as the ratio of norbornane dicarboxylic acid used as a raw material.

(Comparative Example 2) [Synthesis of norbornane skeleton-containing polyamide (PA-6)]
In a 500 ml flask equipped with a stirrer, a thermometer, a nitrogen introduction tube and a cooling tube, 53.00 g (0.250 mol) of norbornane dicarboxylic acid obtained in Synthesis Example 2 and 66.81 g of 4,4′-cyclohexylmethane diisocyanate ( 0.255 mol) (dicarboxylic acid / diisocyanate (molar ratio) = 1.00 / 1.02) and 179.72 g of N-methylpyrrolidone, heated to 160 ° C., reacted for 3 hours, number average A polyamide (PA-6) having a norbornane skeleton having a molecular weight of 55,000 was obtained.
The properties of the obtained polyamide (PA-6) having a norbornane skeleton were evaluated in the same manner as in Example 1. The results are summarized in Table 1.

(Comparative Example 3) [Synthesis of norbornane skeleton-containing polyamide (PA-7)]
In a 500 ml flask equipped with a stirrer, thermometer, nitrogen introduction tube and cooling tube, 57.24 g (0.270 mol) of norbornane dicarboxylic acid obtained in Synthesis Example 2 and 61.14 (0.275 mol) of isophorone diisocyanate ( Dicarboxylic acid / diisocyanate (molar ratio) = 1.00 / 1.02) and 177.57 g of N-methylpyrrolidone were heated to 160 ° C. and reacted for 3 hours to obtain a number average molecular weight of 42,000. A polyamide (PA-7) having a norbornane skeleton was obtained.
The properties of the obtained polyamide (PA-7) having a norbornane skeleton were evaluated in the same manner as in Example 1. The results are summarized in Table 1.

(Comparative Example 4) [Synthesis of norbornane skeleton-containing polyamide (PA-8)]
In a 500 ml flask equipped with a stirrer, a thermometer, a nitrogen introduction tube and a cooling tube, 55.12 g (0.260 mol) of norbornane dicarboxylic acid obtained in Synthesis Example 2 and 66.30 g of 4,4′-diphenylmethane diisocyanate (0 .265 mol) (dicarboxylic acid / diisocyanate (molar ratio) = 1.00 / 1.02) and 182.91 g of N-methylpyrrolidone were heated to 160 ° C. and reacted for 3 hours to obtain a number average molecular weight. Obtained a polyamide (PA-8) having a norbornane skeleton of 42,000.
The properties of the obtained polyamide (PA-8) having a norbornane skeleton were evaluated in the same manner as in Example 1. The results are summarized in Table 1.

  By the production method of the present invention, a norbornane skeleton-containing polyamide having a high exo-isomer ratio, which is excellent in heat resistance, insulation, light resistance and mechanical properties, can be obtained. Therefore, the norbornane skeleton-containing polyamide having a high exo isomer ratio according to the present invention is used as an electronic material used for semiconductors and liquid crystals, an optical material represented by an optical fiber, an optical lens, and the like, as well as a display-related material and a medical material. be able to.

Claims (9)

Norbornane dicarboxylic acid represented by the following formula (I):
A diisocyanate compound represented by the following general formula (II):
(In the formula, X is a divalent organic group.)
A process for producing a norbornane skeleton-containing polyamide in which the reaction is carried out in a polar solvent,
60 mol% or more of the total amount of the norbornane dicarboxylic acid compound is an exo norbornane dicarboxylic acid represented by the following formula (III), and contains the following general formula (IV) containing 60 mol% or more of an exo skeleton. The method for producing a norbornane skeleton-containing polyamide represented by:
(In the formula, X is a divalent organic group. N is an integer of 1 to 500.) The method for producing a norbornane skeleton-containing polyamide according to claim 1, wherein the diisocyanate compound represented by the general formula (II) is a diisocyanate compound represented by the following general formula (V).
(In the formula, Y is a divalent organic group selected from a divalent aliphatic group having 4 to 16 carbon atoms and a divalent alicyclic group having 4 to 16 carbon atoms.) The method for producing a norbornane skeleton-containing polyamide according to claim 1, wherein the diisocyanate compound represented by the general formula (II) is a diisocyanate compound represented by the following general formula (VI).
(In the formula, Y is a divalent aromatic group.) An exo / endo mixed norbornane dicarboxylic acid containing 60 mol% or more of an exo norbornane dicarboxylic acid represented by the formula (III) is obtained by a method including the steps (1) to (2). method for producing norbornane skeleton-containing polyamide as claimed in any one of claims 1 to 3.
(1) Step: Norbornadiene represented by the following formula (VII) and formate represented by the following general formula (VIII),
(However, R < ² >, R < ³ > shows a C1-C5 alkyl group, a vinyl group, and a benzyl group. In addition, R < ² >, R < ³ > may be same or different.)
The reaction is carried out in the presence of a catalyst system containing a ruthenium compound, a cobalt compound, a halide salt, and a basic compound, and 60 mol% of an exo norbornane dicarboxylic acid derivative represented by the following general formula (IX) is obtained. It is set as the exo body / endo body mixed norbornane dicarboxylic acid derivative containing the above.
(However, in the formula, R ² and R ³ each independently represents an alkyl group having 1 to 5 carbon atoms, a vinyl group, or a benzyl group. Note that R ² and R ³ may be the same or different. Good.)
(2) Step: Hydrolyzing the alkoxycarbonyl group of the exo / endo mixed norbornane dicarboxylic acid derivative containing 60 mol% or more of the exo norbornane dicarboxylic acid derivative represented by the general formula (IX), An exo / endo mixed norbornane dicarboxylic acid compound containing 60 mol% or more of the exo norbornane dicarboxylic acid represented by III) is obtained. The method for producing a norbornane skeleton-containing polyamide according to claim 4, wherein the ruthenium compound is a ruthenium complex having both a carbonyl ligand and a halogen ligand in the molecule. The method for producing a norbornane skeleton-containing polyamide according to claim 4 or 5, wherein the halide salt is a quaternary ammonium salt. Method for producing norbornane skeleton-containing polyamide as claimed in any one of claims 4-6, wherein the basic compound is a tertiary amine. Method for producing norbornane skeleton-containing polyamide as claimed in any one of claims 4-7 comprising said catalyst system further phenol compound. Method for producing norbornane skeleton-containing polyamide as claimed in any one of claims 4-8 comprising said catalyst system further organic halogen compound.