JP2003096026A - Method for producing hydroxyalkylcyclohexanecarboxylic acids composition and trans-hydroxyalkylcyclohexanecarboxylic acids - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new hydroxymethylcyclohexanecarboxylic acids composition having high trans isomer content, used as raw materials of various synthetic resins, intermediates of pharmaceuticals or agrochemicals, various chemicals such as solvents and raw materials thereof. SOLUTION: At least one cis isomer of hydroxyalkylcyclohexanecarbonic acids selected from a hydroxyalkylcyclohexanecarbonic acid and its ester is heated for isomerization into trans isomers to produce trans- hydroxymethylcyclohexanecarboxylic acids. The hydroxymethylcyclohexanecarboxylic acids composition containing aforementioned hydroxyalkylcyclohexanecarboxylic acids whose tarns/cis isomer ratio is 40/60 to 99/1 can be obtained.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel hydroxyalkylcyclohexanecarboxylic acid composition comprising at least one hydroxyalkylcyclohexanecarboxylic acid selected from hydroxyalkylcyclohexanecarboxylic acid and its ester, which has a higher proportion of trans isomer than before. The present invention relates to a method for producing a trans-hydroxyalkylcyclohexanecarboxylic acid, which comprises producing a trans isomer from a cis isomer of the above hydroxyalkylcyclohexanecarboxylic acid to obtain a hydroxyalkylcyclohexanecarboxylic acid composition.

[0002]

2. Description of the Related Art Heretofore, hydroxyalkylcyclohexanecarboxylic acids have been useful compounds as various synthetic fibers, synthetic resin raw materials, and intermediates for medicines and agricultural chemicals. This hydroxyalkylcyclohexanecarboxylic acid usually has a cis-form and a trans-form, and the synthetic resin produced from the trans-form has a higher glass transition temperature and softening point than the synthetic resin produced from the cis-form. Therefore, it is expected to have excellent physical properties such as weather resistance and flame retardancy.

As a method for producing this hydroxyalkylcyclohexanecarboxylic acid, for example, French Patent No. 1,44
Japanese Patent Publication No. 7,136 (published date June 20, 1966) describes a method of hydrogenating a benzene ring using p-hydroxymethylbenzoic acid as a reaction substrate and Raney nickel as a catalyst. Also, for example, EP1,04
No. 3,304A1 discloses that hydroxyalkyl cyclohexanecarboxylic acids are produced by hydrogenating an aromatic ring compound group of hydroxyalkyl aromatic carboxylic acids with a catalyst containing at least one element selected from rhodium and ruthenium. How to do is described.

In addition, Tetrahedron Let
t. , Vol. 30, No. 14, p1793-179
No. 6,1989, cis-2-acetoxymethylcyclohexanecarboxylic acid is a hydroxyalkylcyclohexanecarboxylic acid by hydrolyzing cis-2-acetoxymethylcyclohexanecarboxylic acid.
A method of making hydroxymethylcyclohexanecarboxylic acid is described.

[0005]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, French Patent No. 1,447,136 and EP 1,043,30
In the production method in which p-hydroxymethylbenzoic acid is hydrogenated in the presence of a catalyst as described in JP-A No. 4A1, these hydroxyalkylcyclohexanecarboxylic acids have a cis isomer and a trans isomer containing about 80 mol% of the cis isomer. It is obtained as a mixture of That is, the hydroxyalkyl cyclohexanecarboxylic acids obtained by the above production method,
Since the trans form is contained in only about 20 mol%, it is impossible to obtain preferable physical properties in the synthetic resin using the hydroxyalkylcyclohexanecarboxylic acid as a raw material. Also, Tetrahedron Let
t. , Vol. 30, No. 14, p1793-179
According to the method described in 6,1989, only the cis isomer is selectively obtained. Therefore, it has been eagerly desired to obtain a composition having a higher trans content of these hydroxyalkylcyclohexanecarboxylic acids.

The present invention has been made in view of the above problems, and its object is to use it as a raw material for various synthetic resins, various chemicals such as intermediates for medicines and agricultural chemicals, solvents, or raw materials for these chemicals. Another object of the present invention is to provide a novel hydroxymethylcyclohexanecarboxylic acid composition having a higher ratio of trans isomer than ever before. Further, an object of the present invention is to efficiently and inexpensively obtain a cis form of hydroxyalkylcyclohexanecarboxylic acids to obtain the hydroxymethylcyclohexanecarboxylic acid composition in a trans form, which is a trans-hydroxyalkylcyclohexanecarboxylic acid composition. It is to provide a manufacturing method.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies in order to achieve the above object, and as a result, have found that at least one hydroxymethylcyclohexanecarboxylic acid cis form selected from hydroxyalkylcyclohexanecarboxylic acid and its ester and By heating a mixture of trans isomers, the cis isomer can be isomerized to the trans isomer, and a hydroxyalkylcyclohexanecarboxylic acid composition having a higher content of the trans isomer can be obtained, and the present invention was completed. It was

That is, in order to solve the above-mentioned problems, the hydroxyalkylcyclohexanecarboxylic acid composition according to the present invention is a trans form of at least one hydroxyalkylcyclohexanecarboxylic acid selected from hydroxyalkylcyclohexanecarboxylic acid and its ester. It is characterized in that the molar ratio of the cis isomer is in the range of 40/60 to 99/1.

The method for producing trans-hydroxyalkylcyclohexanecarboxylic acids according to the present invention is
In order to solve the above problems, the cis isomer of at least one hydroxyalkylcyclohexanecarboxylic acid selected from hydroxyalkylcyclohexanecarboxylic acid and its ester is heated to isomerize to the trans isomer.

Further, the method for producing trans-hydroxyalkylcyclohexanecarboxylic acids according to the present invention is characterized by heating the cis form of the above hydroxyalkylcyclohexanecarboxylic acids in the presence of a catalyst.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION A hydroxyalkylcyclohexanecarboxylic acid composition according to the present invention comprises at least one hydroxymethylcyclohexanecarboxylic acid selected from hydroxyalkylcyclohexanecarboxylic acid and its ester (hereinafter simply referred to as hydroxymethylcyclohexanecarboxylic acid). ) A novel hydroxymethylcyclohexanecarboxylic acid composition having a higher proportion of trans isomer than a hydroxymethylcyclohexanecarboxylic acid composition produced by a conventional production method as a mixture of cis and trans isomers. The composition has a trans-form / cis-form molar ratio of carboxylic acids in the range of 40/60 to 99/1.

The above-mentioned hydroxyalkylcyclohexanecarboxylic acid composition having a high trans content according to the present invention heats a mixture of cis and trans isomers of at least one hydroxymethylcyclohexanecarboxylic acid selected from hydroxyalkylcyclohexanecarboxylic acid and its ester. Then, it can be obtained by isomerizing the cis isomer to the trans isomer.

That is, the method for producing a trans-hydroxyalkylcyclohexanecarboxylic acid according to the present invention comprises heating a cis-form of at least one hydroxyalkylcyclohexanecarboxylic acid selected from hydroxyalkylcyclohexanecarboxylic acid and its ester to obtain a trans-form. Is a method of isomerizing into.

Hydroxyl used in the present invention
Killcyclohexanecarboxylic acids, that is, the present invention
Hydroxy isomerized from cis form to trans form
Alkylcyclohexanecarboxylic acids are
Rutile cyclohexanecarboxylic acid and its ester
A compound selected from the following general formula (1) HOR¹-Z-COOR²    … (1) (In the formula, Z is 1,2-, 1,3-, 1,4-cyclohexyl
Represents a silene group, R ¹Is an alkylene group having 1 to 4 carbon atoms
Represent, R²Is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms
Represents a compound). The above
Only one type of cyalkylcyclohexanecarboxylic acid
May be used, or a mixture of two or more kinds may be used.
Absent.

Hydroxyalkylcyclohexanecarboxylic acids represented by the above general formula (1), that is, 2-,
Specific examples of the 3-, 4-hydroxyalkylcyclohexanecarboxylic acid and its ester include, for example,
Examples thereof include 2-, 3-, 4-hydroxymethylcyclohexanecarboxylic acid, 2-, 3-, 4-hydroxyethylcyclohexanecarboxylic acid, and their esters.

Among the hydroxyalkylcyclohexanecarboxylic acids used in the present invention, hydroxymethylcyclohexanecarboxylic acid and its ester are more preferable, and 4-hydroxymethylcyclohexanecarboxylic acid and its ester are more preferable.
-Hydroxymethylcyclohexanecarboxylic acid and 4
Methyl hydroxymethylcyclohexanecarboxylate is particularly preferred.

The isomerization of the hydroxyalkylcyclohexanecarboxylic acids from the cis form to the trans form can be carried out only by heating the cis form, that is, cis-hydroxyalkylcyclohexanecarboxylic acids.
A catalyst may be used for the purpose of increasing the reaction rate, that is, the above-mentioned isomerization rate.

That is, in the method for producing trans-hydroxyalkylcyclohexanecarboxylic acids according to the present invention, it is preferable to heat the cis form of the above hydroxyalkylcyclohexanecarboxylic acids in the presence of a catalyst.

The above-mentioned catalyst (isomerization catalyst) optionally used in the method for producing trans-hydroxyalkylcyclohexanecarboxylic acids according to the present invention, that is, in the isomerization of the above-mentioned hydroxyalkylcyclohexanecarboxylic acids, is a catalyst having an isomerization ability. If it is, it will not be specifically limited.

As the isomerization catalyst, an organic or inorganic basic catalyst can be used. The isomerization catalyst may be a homogeneous catalyst or a heterogeneous catalyst.

The isomerization catalyst is not particularly limited, but specifically, for example, an alkali metal,
A compound containing an alkaline earth metal or an element belonging to Group IIIA; an amine compound; a crystalline basic mineral; a basic ion exchange resin;

Alkali metal, alkaline earth metal, IIIA
More specifically, examples of the compound containing an element belonging to the group include oxides, hydroxides, acetates and alkoxides thereof, but are not particularly limited.

Examples of the above oxides include alkali metal oxides such as sodium oxide, potassium oxide and cesium oxide; alkaline earth metal oxides such as magnesium oxide, calcium oxide, barium oxide and barium peroxide; and the like.

The above-mentioned hydroxides include alkali metal hydroxides such as sodium hydroxide, potassium hydroxide and cesium hydroxide; alkaline earth metal hydroxides such as magnesium hydroxide, calcium hydroxide and barium hydroxide. Group IIIA hydroxides such as lanthanum hydroxide and cerium hydroxide;
Etc.

Examples of the above-mentioned acetates include alkali metal acetates such as sodium acetate, potassium acetate and cesium acetate; alkaline earth metal acetates such as magnesium acetate, calcium acetate and barium acetate; group IIIA such as lanthanum acetate and cerium acetate. Acetate; and the like.

Examples of the above-mentioned alkoxides include alkali metal alkoxides such as sodium methoxide, sodium ethoxide, potassium methoxide and potassium ethoxide; magnesium methoxide, calcium methoxide,
Alkaline earth metal alkoxides such as barium methoxide and barium ethoxide; and the like.

Examples of the amine compound include organic amines such as methylamine, ethylamine, ethanolamine, dimethylamine, trimethylamine, triethylamine and ethylenediamine.

Examples of crystalline basic minerals include basic minerals such as hydroxyapatite and hydrotalcite.

As the basic ion exchange resin, a known basic ion exchange resin, for example, a commercially available basic ion exchange resin can be used.

These isomerization catalysts may be used in the form of powder or liquid. When a compound containing an alkali metal, an alkaline earth metal, or an element belonging to Group IIIA is used as the isomerization catalyst, an immobilized inorganic carrier containing these compounds as a catalytically active component, that is, a so-called supported catalyst ( A carrier) may be used as the isomerization catalyst.

The above-mentioned immobilized inorganic carrier is an alkali metal,
It can be easily obtained by supporting a compound containing an alkaline earth metal or an element belonging to Group IIIA on a carrier.
The carrier used when these compounds are used as a supported catalyst is not particularly limited as long as it can immobilize the compound, but specifically,
For example, isocrystalline or amorphous metal oxides such as silicon oxide (silica), aluminum oxide (alumina), titanium oxide (titania), zirconium oxide (zirconia), or composite oxidation of silica-alumina, zeolite, etc. And the like; clay; activated carbon; and the like. These carriers may be used alone or in combination of two or more. Among these carriers, silica, silica-alumina and activated carbon are particularly preferable.

Alkali metal, alkaline earth metal, IIIA
When a compound containing an element belonging to Group III is used as a supported catalyst, the catalytically active component supported on the carrier is not particularly limited as long as it is a compound containing an alkali metal, an alkaline earth metal or an element belonging to Group IIIA. Not a thing,
Among them, a compound containing at least one element selected from the group consisting of sodium, potassium, cesium, barium, magnesium and calcium is preferable. That is, the inorganic carrier-immobilized product is sodium,
It is preferable that at least one element selected from the group consisting of potassium, cesium, barium, magnesium and calcium is immobilized on a carrier.

The method for preparing the above-mentioned isomerization catalyst used in the present invention is not particularly limited, but the preparation method for the case where the above-mentioned isomerization catalyst consists of, for example, the above-mentioned immobilized inorganic carrier is described below. explain.

When the catalytically active component is an inorganic oxide such as an alkali metal or an alkaline earth metal, or an oxide of a compound containing an element belonging to Group IIIA, the above-mentioned elements such as an alkali metal or an alkaline earth metal are included. Finally, it may be supported on the carrier in the form of oxide. In this case, the oxide containing the above element can be directly supported on the carrier,
For the preparation of the isomerization catalyst, generally, a method of carrying the above element on a carrier or oxidizing it in the carrying process is used. The method for supporting the element or its oxide is not particularly limited, and various known supporting methods such as impregnation method, precipitation method, vapor deposition method and the like can be adopted.

An example of a specific method for preparing the above-mentioned inorganic carrier-immobilized product by adopting an impregnation method to support the above elements in the form of an oxide on the carrier as a result will be shown. First, a compound containing the above element is dissolved in a solvent such as water or alcohol to prepare a uniform solution. At this time, you may heat as needed. Next, after adding a carrier to the above solution, the solvent is evaporated to dryness. Further, if necessary, the carrier is further calcined at a predetermined temperature after drying. As a result, an inorganic carrier-immobilized product in which the above-mentioned element is oxidized in the solvent evaporation, dry-solidification step, or firing step to support the oxide of the above-mentioned element on the carrier is prepared. When two or more kinds of elements are loaded on the carrier, the order of loading these elements on the carrier is not particularly limited, and both may be loaded at the same time, and either one may be loaded first. ,
The other may be supported.

The above-mentioned catalyst used as the isomerization catalyst in the present invention may be used alone or in combination of two or more kinds. Among these catalysts,
Alkali metals, alkaline earth metals, oxides, hydroxides and alkoxides of compounds containing elements belonging to Group IIIA, which are basic catalysts; inorganic carriers containing alkali metals, alkaline earth metals, elements belonging to Group IIIA Immobilized substances; crystalline basic minerals are preferable, and among them, sodium hydroxide; potassium hydroxide; barium hydroxide; barium peroxide; sodium methoxide; sodium ethoxide;
Potassium methoxide; potassium ethoxide; at least one element selected from the group consisting of sodium, potassium, cesium, barium, magnesium, and calcium is immobilized on at least one carrier selected from the group consisting of silica, silica-alumina, and activated carbon. An immobilized inorganic carrier, a hydroxyapatite, and hydrotalcite are particularly preferable.

The above-mentioned hydroxyalkylcyclohexanecarboxylic acids which are reaction substrates can be prepared, for example, by the following general formula (2) HOR ¹ -P-COOR ² (2) (wherein P is an o-, m- or p-phenylene group). Represents R
¹ represents an alkylene group having 1 to 4 carbon atoms, R ² represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, or a hydroxyalkylbenzoic acid or ester thereof (hereinafter, hydroxyalkylbenzoic acid (ester ))
Can be obtained by the ring hydrogenation reaction of.

The method for hydrogenating the hydroxyalkyl benzoic acid (ester) is not particularly limited, and for example, the hydroxyalkyl benzoic acid (ester) and the hydrogenation catalyst ( It is possible to proceed by reacting the hydroxyalkyl benzoic acid (ester) with hydrogen (hydrogen reduction) using a reduction catalyst).

The reducing catalyst is not particularly limited, but a catalyst containing at least one noble metal element selected from rhodium and ruthenium is preferably used. Specifically, for example, a supported catalyst in which at least one selected from rhodium and ruthenium is supported on a carrier; oxides such as rhodium oxide and ruthenium oxide;
Rhodium black, ruthenium black, and other metals;
Raney catalysts such as Ranel rhodium and Ranel ruthenium; and the like. Among them, a supported catalyst is particularly preferable because it has excellent catalytic activity and can easily separate the reducing catalyst and the reaction solution after the reaction. These reducing catalysts may be used alone or in combination of two or more.

The reaction conditions such as reaction temperature, reaction pressure, reaction time, etc. can be set according to the type of hydroxyalkyl benzoic acid (ester) used, the type of reduction catalyst, the hydrogen supply method, the hydrogen partial pressure, etc. The reaction temperature is preferably room temperature to 250 ° C., and more preferably 50 ° C. to 200 ° C., although it is not particularly limited. The reaction pressure may be either normal pressure (atmospheric pressure) or increased pressure and is not particularly limited, but is 0.098 MPa.
Is preferably within the range of 24.5 MPa, 0.098M
The range of Pa to 14.7 MPa is more preferable.

In the above-mentioned ring hydrogenation reaction, when the hydroxyalkyl benzoic acid ester is liquid under the above-mentioned reaction conditions, it is not necessary to use a solvent, but depending on the reaction conditions and the reaction method, for example, ring-hydrogenation When the reaction is violent, the reaction solution can be diluted with a solvent inert to the reaction, if necessary. For example, after mixing hydroxyalkyl benzoic acid (ester) with an appropriate amount of solvent, a reducing catalyst is added, the system is replaced with an inert gas, hydrogen gas is introduced, and heating is performed as necessary. By doing so, the ring hydrogenation reaction can easily proceed.

The solvent is not particularly limited, but specifically, for example, water; methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, sec- Butyl alcohol, tert-butyl alcohol and the like, alcohols having 1 to 6 carbon atoms; ethers such as isopropyl ether, tetrahydrofuran and dioxane; saturated hydrocarbon compounds having 5 to 8 carbon atoms such as pentane, hexane and cyclohexane; Can be mentioned. These solvents may be used alone or in combination of two or more.

The above-mentioned hydroxyalkylcyclohexanecarboxylic acids can be obtained, for example, by preparing a reaction liquid from which a reduction catalyst is separated,
It can be easily isolated by distillation or crystallization. In addition, the above-mentioned hydroxyalkylcyclohexanecarboxylic acids may be purified as required after isolation.

The method for producing the hydroxyalkylcyclohexanecarboxylic acids used in the present invention is not limited to the above-mentioned production method. That is, as the hydroxyalkylcyclohexanecarboxylic acid used as a raw material in the method for producing trans-hydroxyalkylcyclohexanecarboxylic acid in the present invention, hydroxyalkylcyclohexanecarboxylic acid obtained by various known production methods can be used.

However, the hydroxyalkylcyclohexanecarboxylic acid obtained by the above-mentioned production method or a known production method other than the above-mentioned production method usually has a trans isomer / cis isomer molar ratio within the range of 20/80 to 30/70. , A mixture of cis and trans isomers.

Therefore, as a raw material used in the method for producing trans-hydroxyalkylcyclohexanecarboxylic acids according to the present invention, cis-hydroxyalkylcyclohexanecarboxylic acids may be used alone, but usually hydroxyalkylcyclohexanecarboxylic acids are used. A mixture of the cis form and the trans form is used.
As the raw material used in the method for producing trans-hydroxyalkylcyclohexanecarboxylic acid according to the present invention, the hydroxyalkylcyclohexanecarboxylic acid obtained by the above production method or a known production method other than the above production method can be used as it is. Therefore, the mixture, that is, the raw material used in the method for producing the trans-hydroxyalkylcyclohexanecarboxylic acid, the compound other than the cis and trans isomers of the hydroxyalkylcyclohexanecarboxylic acid, such as unreacted monomers and impurities and solvents May be included.

According to the present invention, a mixture of the cis isomer and the trans isomer of the hydroxyalkylcyclohexanecarboxylic acid is used as a raw material to heat the cis isomer of the hydroxyalkylcyclohexanecarboxylic acid to isomerize into the trans isomer. , Trans-form / cis-form molar ratio within the range of 40/60 to 99/1, preferably 50/50 to
It is possible to obtain a novel hydroxyalkylcyclohexanecarboxylic acid composition having a trans content higher than that of the conventional composition, which is within the range of 99/1.

It is desirable that the above isomerization reaction is carried out without a solvent, since the subsequent solvent removal operation can be omitted. When the hydroxyalkylcyclohexanecarboxylic acid used as a raw material during the reaction is in a liquid state, it is not necessary to use a solvent. However, for example, when an isomerization catalyst is used for the isomerization, the isomerization catalyst and the isomerization catalyst are sufficient. When it is impossible to make uniform contact or when the reaction is violent, the reaction solution can be diluted with a solvent inert to the reaction.

The solvent is not particularly limited as long as it is an inert solvent for the isomerization reaction, and the amount used is also not particularly limited. As the solvent,
For example, a solvent such as water, alcohol or hydrocarbon can be used.

The isomerization reaction may be carried out in any of a continuous system, a batch system and a semi-batch system, and is not particularly limited. The above-mentioned isomerization catalyst may be batch-charged together with the raw materials in the reaction device when, for example, a batch system is adopted as the reaction form, and when the reaction system is, for example, a continuous system, the reaction device is previously charged. Just fill it up. The isomerization catalyst may be used in the form of a fixed bed or a suspension bed.

The amount of the isomerization catalyst used in the above-mentioned isomerization reaction, that is, the amount of the isomerization catalyst used for the above-mentioned hydroxyalkylcyclohexanecarboxylic acids depends on the kind of these hydroxyalkylcyclohexanecarboxylic acids, the composition of the catalyst, the reaction conditions, etc. However, when the isomerization catalyst is dissolved in the reaction solution, that is, when the isomerization catalyst is a homogeneous catalyst, the reaction substrate hydroxyalkyl It is preferable to use the above isomerization catalyst in an amount of 0.001% by weight or more and 50% by weight or less with respect to cyclohexanecarboxylic acid, and 0.01
It is more preferable to use it in a proportion of not less than 20% by weight and not more than 20% by weight.

When the isomerization catalyst is not dissolved in the reaction solution, that is, when the isomerization catalyst is a heterogeneous catalyst, the isomerization catalyst is added to the reaction substrate hydroxyalkylcyclohexanecarboxylic acid. , 0.
It is preferable to use it in a proportion of 001% by weight or more and 50% by weight or less, and it is more preferable to use it in a proportion of 0.01% by weight or more and 30% by weight or less.

When the isomerization catalyst according to the present invention is a supported catalyst, the amount of the basic catalyst supported on the carrier depends on the desired catalyst composition (for example, the type of oxide,
It may be appropriately set according to (type of basic catalyst to be supported) and the like, and is not particularly limited, but with respect to the carrier,
It is preferably in the range of 0.01% by weight to 80% by weight, and
More preferably within the range of 1% by weight to 50% by weight, and 0.5
More preferably, it is in the range of 20% by weight to 20% by weight. When the amount of the basic catalyst carried is within the above range, the catalytic activity is high, and the isomerization of the hydroxyalkylcyclohexanecarboxylic acids can be efficiently performed, that is, the trans form of the hydroxyalkylcyclohexanecarboxylic acids can be industrially produced. Therefore, it is preferable in that it can be obtained efficiently and inexpensively.

The reaction temperature in the above isomerization reaction may be appropriately set according to the reaction substrate and the reaction method,
Although not particularly limited, it is usually 50 ° C to 250 ° C.
It is in the range of 0 ° C, preferably in the range of 130 ° C to 200 ° C, and more preferably in the range of 140 ° C to 190 ° C. When the reaction temperature is in the range of 50 ° C. to 250 ° C., the reaction rate is fast, side reactions are unlikely to occur, and the hydroxyalkylcyclohexanecarboxylic acids can be efficiently isomerized, which is preferable.

The reaction pressure may be normal pressure (atmospheric pressure) or increased pressure. Moreover, the reaction atmosphere is not particularly limited, and may be, for example, air or an inert gas such as nitrogen or argon.

By carrying out the above reaction, isomerization of the above hydroxyalkylcyclohexanecarboxylic acids can be carried out. As a result, a reaction solution containing the trans form of the above hydroxyalkylcyclohexanecarboxylic acids is obtained. It can be confirmed, for example, by gas chromatography that the trans isomer of the hydroxyalkylcyclohexanecarboxylic acid is contained as a product in the obtained reaction liquid. When a mixture of the cis and trans isomers of the hydroxyalkylcyclohexanecarboxylic acids is used as the reaction substrate, the trans isomer of the hydroxyalkylcyclohexanecarboxylic acids is
A reaction solution containing a larger proportion than before the reaction is obtained.

In the obtained reaction liquid, in addition to the trans isomer of the above-mentioned hydroxyalkylcyclohexanecarboxylic acid which is the target product, the cis-isomer of the above-mentioned unreacted hydroxyalkylcyclohexanecarboxylic acid, and the isomerization catalyst (used) (If used), or solvent (if used), etc. are included.

That is, the hydroxyalkylcyclohexanecarboxylic acid composition may contain other components other than the cis and trans isomers of the hydroxyalkylcyclohexanecarboxylic acid. The lower limit of the total content of the cis form and the trans form of the hydroxyalkylcyclohexanecarboxylic acids in the hydroxyalkylcyclohexanecarboxylic acid composition is 20% by weight or more, preferably 40% by weight or more, more preferably 60% by weight or more. , And more preferably 80% by weight
Above, particularly preferably 90% by weight or more, the upper limit is 100% by weight or less, preferably 98% by weight or less, more preferably 96% by weight or less.

In the case where the isomerization catalyst is a heterogeneous catalyst, the isomerization catalyst is prepared by various conventionally known methods such as filtration, centrifugation, distillation, crystallization, decantation of the reaction solution, and In the case where the isomerization catalyst is a homogeneous catalyst, various conventionally known methods such as distillation, crystallization, extraction, etc.
Can be separated.

The obtained hydroxyalkylcyclohexanecarboxylic acid composition having a high content of trans isomer is used, if necessary, in order to remove impurities generated in the reaction, or a hydroxyalkylcyclohexanecarboxylic acid composition having a higher content of trans isomer. In order to obtain it, it can be processed by a conventionally known method such as distillation, crystallization, recrystallization, extraction and the like.

The cis-hydroxyalkylcyclohexanecarboxylic acid or hydroxyalkylcyclohexanecarboxylic acid composition having a high cis content, which was separated and recovered by the above treatment, the solvent (when used), and the catalyst (when used) were again It can be recycled for the isomerization reaction.

When the recovered isomerization catalyst has reduced (deteriorated) catalytic activity due to, for example, adhesion of organic substances, the isomerization catalyst is washed with a solvent or recalcined, for example. As a result, it can be reused in the above isomerization reaction after being reactivated.

The hydroxyalkylcyclohexanecarboxylic acid and its ester used in the present invention are
It is a very useful compound as a raw material for various synthetic resins, various chemicals such as solvents, or a raw material for these chemicals, and its trans form is a synthetic resin with more excellent physical properties than the cis form. You can expect to get etc.

According to the present invention, by using the hydroxyalkylcyclohexanecarboxylic acid composition having a high trans content according to the present invention as a raw material for various synthetic fibers, synthetic resins and the like, the glass transition temperature and the softening point are high and the weather resistance is high. It is possible to manufacture synthetic fibers, synthetic resins, etc., which are expected to have excellent properties such as properties and flame retardancy.

According to the present invention, trans-hydroxyalkylcyclohexanecarboxylic acids (hydroxyalkyl with a high trans content) are raw material monomers for various synthetic fibers and synthetic resins which are expected to have high performance in terms of weather resistance and flame retardancy. The cyclohexanecarboxylic acid composition) can be industrially produced at low cost.

[0066]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.

Example 1 p-Hydroxymethylbenzoic acid (manufactured by Tokyo Kasei) was used at 100 ° C. and 9.8 MPa in methanol as a solvent, using ruthenium carbon (manufactured by Kawaken Fine) as a reducing catalyst. Catalytic hydrogenation reaction,
4-Hydroxymethylcyclohexanecarboxylic acid was obtained by hydrogenating the benzene ring. Then this 4
-Hydroxymethylcyclohexanecarboxylic acid is esterified in methanol to give trans-form 1.
9.1 mol% and cis isomer 80.9 mol% contained in 4-
Obtained was methyl hydroxymethylcyclohexanecarboxylate as a raw material.

The trans form and the cis form are referred to as trans form 1
9.1 mol% and cis isomer 80.9 mol% contained in 4-
Methyl hydroxymethylcyclohexanecarboxylate 10
g as a raw material, 10 g of methyl 4-hydroxymethylcyclohexanecarboxylate and 1.0 g of 50 wt% sodium hydroxide aqueous solution as an isomerization catalyst were charged into a 30 ml flask equipped with a reflux tube, and the mixture was heated at 180 ° C. for 3 hours. After stirring, an isomerization reaction of methyl cis-4-hydroxymethylcyclohexanecarboxylate was performed.

After completion of the reaction, the resulting reaction solution was cooled to room temperature and its composition was analyzed by gas chromatography (GC). As a result, the recovery rate of methyl 4-hydroxymethylcyclohexanecarboxylate was 89 mol%.
Trans-cis isomer ratio of methyl hydroxymethylcyclohexanecarboxylate (molar ratio of trans isomer / cis isomer)
Was 0.68 / 0.32.

Example 2 5 g of spherical silicon oxide (silica) (trade name "CARIACT Q-10", manufactured by Fuji Silysia Ltd.) was placed in a mortar, and 10.3 g of a 10 wt% barium hydroxide aqueous solution was placed therein. Was added and the mixture was heated to 80 ° C., and water was slowly evaporated with stirring. Then 120
Dried overnight at 500 ° C. and calcined in air at 500 ° C. for 4 hours, 10% by weight of barium oxide was immobilized on silica,
Silica-supported barium oxide was prepared as an isomerization catalyst.

10 g of methyl 4-hydroxymethylcyclohexanecarboxylate containing the trans form and the cis form obtained in Example 1 in a ratio of 19.1 mol% trans form and 80.9 mol% cis form was used as a raw material. Used, 10 g of methyl 4-hydroxymethylcyclohexanecarboxylate
And 1.0 g of the above silica-supported barium oxide as an isomerization catalyst were charged in a 30 ml flask equipped with a reflux tube,
The mixture was stirred at 180 ° C. for 6 hours to carry out an isomerization reaction of methyl cis-4-hydroxymethylcyclohexanecarboxylate.

After completion of the reaction, the obtained reaction solution was cooled to room temperature and its composition was analyzed by gas chromatography (GC). As a result, the recovery rate of methyl 4-hydroxymethylcyclohexanecarboxylate was 95 mol%.
Trans-cis isomer ratio of methyl hydroxymethylcyclohexanecarboxylate (molar ratio of trans isomer / cis isomer)
Was 0.52 / 0.48.

50 ml of water and 2.5 g of sodium hydroxide were added to the resulting reaction solution, and the mixture was stirred at 60 ° C. for 2 hours. The obtained reaction solution was neutralized to pH 7 with 0.1N hydrochloric acid and then analyzed by liquid chromatography (LC). As a result, the hydrolysis conversion rate was 100%, and the trans-cis isomer ratio (trans isomer / cis isomer molar ratio) of 4-hydroxymethylcyclohexanecarboxylic acid was 0.52 /.
It was 0.48.

[0074]

As described above, according to the present invention, at least one hydroxyalkylcyclohexanecarboxylic acid cis isomer selected from hydroxyalkylcyclohexanecarboxylic acid and its ester is heated to isomerize into a trans isomer. Thus, it is possible to produce trans-hydroxyalkylcyclohexanecarboxylic acid efficiently and easily. Thus, according to the present invention, the trans isomer / cis isomer molar ratio of at least one hydroxyalkylcyclohexanecarboxylic acid selected from hydroxyalkylcyclohexanecarboxylic acid and its ester is 40/60 to 99 /.
The effect of being able to provide a novel hydroxyalkylcyclohexanecarboxylic acid composition having a high trans content, which is within the range of 1, is exerted. The trans form of the hydroxyalkylcyclohexanecarboxylic acids is a raw material for various synthetic resins, various chemicals such as solvents, or
It is a very useful compound as a raw material for these chemicals, and its trans form can give a synthetic resin or the like having more excellent physical properties than the cis form. Therefore, by using the above-mentioned hydroxyalkylcyclohexanecarboxylic acid composition having a high trans content as a raw material for various synthetic fibers and synthetic resins, the glass transition temperature and the softening point are high, and the weather resistance and flame retardancy, etc. It is possible to produce synthetic fibers, synthetic resins, etc., which are expected to have excellent physical properties.

Claims (3)

[Claims] 1. A trans-cis / cis-molar ratio of at least one hydroxyalkylcyclohexanecarboxylic acid selected from hydroxyalkylcyclohexanecarboxylic acid and its ester is in the range of 40/60 to 99/1. A hydroxyalkylcyclohexanecarboxylic acid composition comprising: 2. A trans-hydroxyalkylcyclohexanecarboxylic acid which is characterized in that at least one hydroxyalkylcyclohexanecarboxylic acid cis isomer selected from hydroxyalkylcyclohexanecarboxylic acid and its ester is heated to isomerize into a trans isomer. Manufacturing method. 3. The method for producing trans-hydroxyalkylcyclohexanecarboxylic acids according to claim 2, wherein the cis form of the hydroxyalkylcyclohexanecarboxylic acids is heated in the presence of a catalyst.