Method for producing metal salt of alicyclic dicarboxylic acid

Abstract

A method for producing a metal salt of an alicyclic dicarboxylic acid (a calcium salt, a hydroxyaluminum salt, a disodium salt, or a dilithium salt of an alkyl-substituted 1,2-dicarboxylic acid) is provided, the method making it possible to reduce discard loss, being simple, and having excellent selectivity (molar ratio of a cis-isomer).　The method for producing a metal salt of an alicyclic dicarboxylic acid is characterized in that the alicyclic dicarboxylic acid is a metal salt of a cyclohexane-1,2-dicarboxylic acid having at least one alkyl substituent directly bonded to the cyclohexane ring, the alkyl substituent being a C1-C4 linear or branched alkyl group, that the metal salt is a calcium salt, a hydroxyaluminum salt, a disodium salt, or a dilithium salt, and that the method includes steps (1) and (2).

Description

Method for producing metal salts of alicyclic dicarboxylic acids

[0001] The present invention relates to a method for producing a metal salt of an alicyclic dicarboxylic acid.

[0002] The present inventors have been developing metal salts of various carboxylic acids as crystal nucleating agents for crystalline thermoplastic resins, and as a result, it has become clear that metal salts of alkyl-substituted cyclohexane-1,2-dicarboxylic acids exhibit excellent nucleating agent performance in resins such as polyolefins.

[0003] Furthermore, the present inventors have conducted a detailed study into the influence of the structure of metal salts of alkyl-substituted cyclohexane-1,2-dicarboxylic acids on their nucleating agent performance, and have confirmed that excellent nucleating agent performance is exhibited when the metal species forming the metal salt is calcium or sodium. They have also found that the steric structure of the alkyl substituents positioned via the cyclohexane ring and the oxycarbonyl group forming the metal salt has a significant effect, and ultimately found that the excellent nucleating agent performance correlates with the molar ratio of the cis isomer (see Patent Document 1).

[0004] International Publication No. 2020 / 054492

[0005] Generally, the metal salts of alkyl-substituted cyclohexane-1,2-dicarboxylic acids are produced through the following steps (1) to (3): (1) A conjugated diene compound and maleic anhydride are subjected to a Diels-Alder reaction to obtain alkyl-substituted 4-cyclohexene-1,2-dicarboxylic anhydride. Alternatively, alkyl-substituted phthalic anhydride is obtained by, for example, adding an alkyl substituent to phthalic anhydride. (2) Alkyl-substituted 4-cyclohexene-1,2-dicarboxylic anhydride or alkyl-substituted phthalic anhydride is subjected to a hydrogenation reaction to obtain alkyl-substituted cyclohexane-1,2-dicarboxylic anhydride. (3) Alkyl-substituted cyclohexane-1,2-dicarboxylic anhydride is reacted with an oxide, hydroxide, or chloride of a metal species that forms the desired metal salt.

[0006] In the above reaction system, the steric structure of the alkyl substituent located via the cyclohexane ring, which significantly affects the nucleating agent performance, and the oxycarbonyl group forming the metal salt is determined by the molar ratio of cis / trans isomers. When an alkyl-substituted phthalic anhydride is used as a raw material for the hydrogenation reaction, the molar ratio is determined during the hydrogenation reaction (the above step (2)).

[0007] When a hydrogenation reaction is carried out using alkyl-substituted 4-cyclohexene-1,2-dicarboxylic anhydride, the molar ratio of the isomers of the alkyl substituents at the 3- and 6-positions is determined during the Diels-Alder reaction and the hydrogenation reaction. Furthermore, the molar ratio of the isomers of the alkyl substituents at the 4- and 5-positions is determined during the hydrogenation reaction. In other words, the cis / trans isomer ratio is already determined at the stage prior to conversion into a metal salt (prior to the above step (3)).

[0008] In both the Diels-Alder reaction and the hydrogenation reaction, the production of the cis isomer is stereochemically predominant, and even under typical reaction conditions, it is possible to obtain alkyl-substituted cyclohexane-1,2-dicarboxylic acids with a molar ratio of cis isomer of 60 to 70% or more. Furthermore, it has been confirmed that by devising the reaction conditions, alkyl-substituted cyclohexane-1,2-dicarboxylic acids with a molar ratio of cis isomer of nearly 100% can be obtained in the reaction system.

[0009] However, the double bond of the alkyl-substituted 4-cyclohexene-1,2-dicarboxylic anhydride used as the raw material easily migrates due to heat or the like (for example, this is likely to occur in step (2) (hydrogenation reaction) in the conventional method), resulting in the generation of impurities (ring structure isomers such as Δ1 type) and a decrease in selectivity. Therefore, the molar ratio of the cis isomer at the end of the reaction is usually limited to about 85%, and it has been difficult to reach 90% even under special conditions using a large amount of solvent or the like.

[0010] Furthermore, since the relative volatility of the cis- and trans-isomers of alkyl-substituted cyclohexane-1,2-dicarboxylic acids is similar, the number of theoretical plates required to remove the trans-isomer is 100 or more, which poses problems such as the need for a large amount of heat and a high waste loss due to a low recovery rate.

[0011] Therefore, an object of the present invention is to provide a method for producing a metal salt of an alicyclic dicarboxylic acid (a calcium salt, a hydroxyaluminum salt, a disodium salt, or a dilithium salt of an alkyl-substituted 1,2-dicarboxylic acid) simply and easily, which method can reduce waste and has excellent selectivity (molar ratio of cis isomer).

[0012] As a result of intensive investigations conducted by the present inventors to solve the above-mentioned problems, they have found that all of the above-mentioned problems can be solved by using a method for producing a metal salt of an alicyclic dicarboxylic acid, the method including: a step (1) of obtaining an alkali metal salt or an ammonium salt using cyclohexene-1,2-dicarboxylic anhydride having a linear or branched alkyl substituent having 1 to 4 carbon atoms or phthalic anhydride having a linear or branched alkyl substituent having 1 to 4 carbon atoms as a raw material; and a step (2) of carrying out a hydrogenation reaction using the alkali metal salt or ammonium salt obtained in the step (1), and have thus completed the present invention.

[0013] That is, the present invention provides a method for producing a metal salt of an alicyclic dicarboxylic acid, the method comprising the steps (1) and (2) below: Step (1): obtaining an alkali metal salt or an ammonium salt using cyclohexene-1,2-dicarboxylic anhydride having a linear or branched chain alkyl group with 1 to 4 carbon atoms or phthalic anhydride having a linear or branched chain alkyl group with 1 to 4 carbon atoms as a raw material; and Step (2): performing a hydrogenation reaction using the alkali metal salt or ammonium salt obtained in Step (1).

[0014] In the method for producing a metal salt of an alicyclic dicarboxylic acid of the present invention, the alkali metal salt in step (1) is preferably at least one selected from the group consisting of sodium salts, potassium salts, and lithium salts. It is more preferable that the alkali metal salt in step (1) is a sodium salt. It is preferable that the catalyst for the hydrogenation reaction in step (2) is at least one selected from the group consisting of palladium, rhodium, and ruthenium. It is also preferable that the temperature of the hydrogenation reaction in step (2) is 80°C or lower. It is also preferable that the method further comprises step (3) below. Step (3): A step of converting the hydrogenated alkali metal salt or ammonium salt obtained in step (2) into a calcium salt or disodium salt. It is also preferable that the method further comprises step (4) below after step (2). Step (4): A step of crystallizing the hydrogenated alkali metal salt or ammonium salt obtained in step (2). It is also preferable that the alkali metal salt crystallized in step (4) is a monoalkali metal salt. The alkyl substituent is preferably located at the 3rd or 4th position of the cyclohexane ring. The alkyl substituent is preferably a methyl group. Among the stereoisomers of the alkyl substituent via the cyclohexane ring of the alicyclic dicarboxylic acid and the oxycarbonyl group constituting the metal salt, the molar ratio of cis isomers is preferably 90.0% or more, more preferably 93.0% or more, and even more preferably 95% or more.

[0015] The present invention provides a method for producing a metal salt of an alicyclic dicarboxylic acid (a calcium salt, hydroxyaluminum salt, disodium salt, or dilithium salt of an alkyl-substituted 1,2-dicarboxylic acid) simply and with excellent selectivity (molar ratio of cis isomer), which can reduce waste.

[0016] The method for producing a metal salt of an alicyclic dicarboxylic acid of the present invention is a method for producing a metal salt of an alicyclic dicarboxylic acid, wherein the alicyclic dicarboxylic acid is a metal salt of cyclohexane-1,2-dicarboxylic acid having at least one alkyl substituent directly bonded to the cyclohexane ring, the alkyl substituent being a linear or branched alkyl group having 1 to 4 carbon atoms, and the metal salt being a calcium salt, hydroxyaluminum salt, disodium salt, or dilithium salt, and the method is characterized by comprising the following steps (1) and (2): Step (1): A step of obtaining an alkali metal salt or an ammonium salt using cyclohexene-1,2-dicarboxylic anhydride having a linear or branched alkyl substituent having 1 to 4 carbon atoms or phthalic anhydride having a linear or branched alkyl substituent having 1 to 4 carbon atoms as a raw material; and Step (2): A step of performing a hydrogenation reaction using the alkali metal salt or ammonium salt obtained in Step (1).

[0017] The method for producing a metal salt of an alicyclic dicarboxylic acid of the present invention includes the above-mentioned steps (1) and (2), and therefore can produce the target metal salt of an alicyclic dicarboxylic acid (calcium salt, hydroxyaluminum salt, disodium salt, or dilithium salt of an alkyl-substituted 1,2-dicarboxylic acid) having a high molar ratio of cis isomer in high yield. Furthermore, since a purification step (such as a distillation step) can be omitted, waste loss can also be reduced.

[0018] The term "cis isomer" in the calcium salt, hydroxyaluminum salt, disodium salt, or dilithium salt of alkyl-substituted 1,2-dicarboxylic acid means that the alkyl substituent on the cyclohexane ring and the two oxycarbonyl groups constituting the metal salt all point in the same direction.

[0019] Each step will be described below.

[0020] <Step (1)> The method for producing a metal salt of an alicyclic dicarboxylic acid of the present invention includes the following step (1): Step (1): A step of obtaining an alkali metal salt or an ammonium salt using cyclohexene-1,2-dicarboxylic anhydride having a linear or branched alkyl substituent having 1 to 4 carbon atoms (also referred to as alkyl-substituted cyclohexene-1,2-dicarboxylic anhydride) or phthalic anhydride having a linear or branched alkyl substituent having 1 to 4 carbon atoms (also referred to as alkyl-substituted phthalic anhydride) as a raw material.

[0021] The alkyl-substituted cyclohexene-1,2-dicarboxylic anhydride preferably has a linear or branched alkyl substituent having 1 to 4 carbon atoms at the 3- or 4-position, more preferably at the 4-position.

[0022] In the alkyl-substituted cyclohexene-1,2-dicarboxylic anhydride, examples of the linear or branched alkyl substituent having 1 to 4 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, etc. Among these, a methyl group or a tert-butyl group is preferred from the viewpoint of the crystallization-promoting effect when the resulting metal salt of an alicyclic dicarboxylic acid is used as a crystal nucleating agent.

[0023] The alkyl-substituted phthalic anhydride preferably has a linear or branched alkyl substituent having 1 to 4 carbon atoms at the 3- or 4-position, more preferably at the 4-position.

[0024] In the alkyl-substituted phthalic anhydride, examples of the linear or branched alkyl substituent having 1 to 4 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, etc. Among these, a methyl group or a tert-butyl group is preferred from the viewpoint of the crystallization-promoting effect when the resulting metal salt of an alicyclic dicarboxylic acid is used as a crystal nucleating agent.

[0025] The alkali metal salt or ammonium salt obtained in the above step (1) can be obtained by reacting the above alkyl-substituted cyclohexene-1,2-dicarboxylic anhydride or the above alkyl-substituted phthalic anhydride with an alkali metal hydroxide or an amine to ring-open the acid anhydride.

[0026] Examples of the alkali metal hydroxide include hydroxides of sodium, potassium, lithium, etc.

[0027] Examples of the amine include triethylamine, ammonia, and trimethylamine.

[0028] The amount of the alkali metal hydroxide or amine used is preferably 1 equivalent or more and 2 equivalents or less, and more preferably 1.1 equivalents or more and 1.9 equivalents or less, relative to the alkyl-substituted cyclohexene-1,2-dicarboxylic anhydride or the alkyl-substituted phthalic anhydride, from the viewpoint of stereoselectivity.

[0029] The alkali metal salt or ammonium salt obtained in the above step (1) is preferably at least one selected from sodium salt, potassium salt and lithium salt, more preferably sodium salt or potassium salt, and even more preferably sodium salt.

[0030] In the above step (1), the reaction method and reaction conditions are not particularly limited as long as an alkali metal salt or an ammonium salt can be obtained. A typical method involves adding the alkyl-substituted cyclohexene-1,2-dicarboxylic anhydride or the alkyl-substituted phthalic anhydride to a solution prepared by dissolving the alkali metal hydroxide or amine in water, and stirring the mixture at room temperature or under slight heating.

[0031] By undergoing the above step (1), when general-purpose water is used in the next step (2), it is possible to make the reaction system homogeneous from the initial stage of the reaction. This effect is particularly pronounced when the reaction temperature is lowered to increase the molar ratio of the cis isomer. Therefore, by including the above step (1), it is not necessary to use a special solvent, and it is possible to simplify the production and reduce costs.

[0032] <Step (2)> The method for producing a metal salt of an alicyclic dicarboxylic acid of the present invention includes the following step (2): Step (2): A step of hydrogenating the alkali metal salt or ammonium salt obtained in the above step (1).

[0033] The hydrogenation reaction in the above step (2) is preferably carried out under the following conditions.

[0034] (a) Concentration In the step (2), a solution of the alkali metal salt or ammonium salt (also referred to as a substrate) obtained in the step (1) is used. The concentration of the substrate is not particularly limited, but is preferably 1% by mass or more and 25% by mass or less, and more preferably 5% by mass or more and 20% by mass or less.

[0035] (b) Reaction catalyst Palladium, ruthenium, and rhodium are preferred as the reaction catalyst from the viewpoint of increasing the molar ratio of the cis isomer obtained. A more preferred reaction catalyst is selected depending on the position and type of alkyl substituents on the alkali metal salt or ammonium salt obtained in step (1) or the type of acid anhydride. For example, when the alkyl-substituted cyclohexene-1,2-dicarboxylic anhydride is used, palladium and ruthenium are preferred, and when the alkyl-substituted phthalic anhydride is used, rhodium and ruthenium are preferred.

[0036] The reaction catalyst may be supported on a carrier such as carbon, alumina, silica, zirconia, zeolite, etc. In this case, the supported amount is preferably 0.1 to 10 mass %.

[0037] The amount of the reaction catalyst used is preferably 0.1 to 5 parts by mass per 100 parts by mass of the alkali metal salt or ammonium salt obtained in the above step (1).

[0038] (c) Reaction Temperature The reaction temperature is preferably 80°C or lower from the viewpoint of suppressing the generation of the above-mentioned impurities (ring structure isomers such as Δ1 type) and a decrease in selectivity. If the reaction temperature is 80°C or lower, a metal salt of an alicyclic dicarboxylic acid having a molar ratio of cis isomer of 90.0% or higher can be suitably obtained. The reaction temperature is more preferably 60°C or lower.

[0039] (d) Reaction Pressure From the viewpoint of suppressing the generation of the above-mentioned impurities (ring structure isomers such as Δ1 type) and a decrease in selectivity, the reaction pressure is preferably 0.1 MPa or more in hydrogen pressure (gauge pressure), more preferably 0.9 MPa or more, even more preferably 1.8 MPa or more, and particularly preferably 4 MPa or more. Furthermore, in consideration of the problem of the need for high-pressure gas equipment, the reaction pressure can also be set to less than 1.0 MPa in hydrogen pressure (gauge pressure). By setting the hydrogen pressure (gauge pressure) to less than 1.0 MPa, industrially suitable production can be achieved.

[0040] (e) Reaction Time The reaction time is not particularly limited, but is preferably, for example, 30 minutes to 5 hours. The reaction time means the time from when the reaction temperature is reached to when the reaction is completed.

[0041] (f) Reaction Solvent Water may be used as the solvent.

[0042] <Step (3)> The method for producing a metal salt of an alicyclic dicarboxylic acid of the present invention preferably further includes the following step (3) as necessary: ​​Step (3): A step of converting the hydrogenated alkali metal salt or ammonium salt (also simply referred to as a hydrogenated compound) obtained in the above step (2) into a calcium salt, a hydroxyaluminum salt, a disodium salt, or a dilithium salt.

[0043] When the target metal salt of an alicyclic dicarboxylic acid is a disodium salt, if the alkali metal salt obtained in the above step (1) is a sodium salt, it can be converted into a disodium salt by appropriately reacting it with an aqueous sodium hydroxide solution after the above step (2), and the above step (3) can be omitted. On the other hand, if the alkali metal salt obtained in the above step (1) is other than a sodium salt, it can be converted into a carboxylic acid by returning the hydrogenated compound obtained in the above step (2) to the carboxylic acid and then reacting it with an aqueous sodium hydroxide solution.

[0044] When the target metal salt of an alicyclic dicarboxylic acid is a dilithium salt, if the alkali metal salt obtained in the above step (1) is a lithium salt, it can be converted into a dilithium salt by appropriately reacting it with an aqueous lithium hydroxide solution after the above step (2), and the above step (3) can be omitted. On the other hand, if the alkali metal salt obtained in the above step (1) is not a lithium salt, it can be converted into a carboxylic acid by converting the hydrogenated compound obtained in the above step (2) back into the carboxylic acid and then reacting it with an aqueous lithium hydroxide solution.

[0045] When the target metal salt of an alicyclic dicarboxylic acid is a calcium salt or a hydroxyaluminum salt, it can be easily produced by a method such as a so-called metathesis method in which the hydrogenated compound obtained in the above step (2) is reacted with a hydroxide, oxide, chloride, or the like of calcium or hydroxyaluminum.

[0046] When a solvent is used in the above step (3), it is preferably water.

[0047] <Step (4)> The method for producing a metal salt of an alicyclic dicarboxylic acid of the present invention preferably further includes the following step (4) after the step (2), as necessary: ​​Step (4): A step of crystallizing the hydrogenated compound obtained in the step (2).

[0048] By including the step (4), the molar ratio of the cis isomer of the target metal salt of an alicyclic dicarboxylic acid can be suitably increased. When the step (3) is included, it is preferable to carry out the step (4) before the step (3).

[0049] In the step (4), for example, the hydrogenated compound obtained in the step (2) can be dissolved in a solvent such as water under heating, and then cooled to crystallize the cis isomer. The solution of the hydrogenated compound obtained in the step (2) can also be used as it is.

[0050] The alkali metal salt or ammonium salt crystallized in step (4) is preferably a monoalkali metal salt or a monoammonium salt from the viewpoint of solubility in water. Specifically, the equivalent of the alkali metal salt or ammonium salt crystallized in step (4) (the equivalent of the alkali metal salt (ammonium salt) relative to the alicyclic dicarboxylic acid) is preferably 1.0 to 1.3 equivalents.

[0051] The above step (4) is preferably carried out under the following conditions.

[0052] (a) Solvent The solvent is preferably one in which the cis isomer has a relatively low solubility and in which the cis isomer is selectively precipitated, and in consideration of environmental aspects, water is more preferable.

[0053] (b) Concentration The concentration of the hydrogenated compound (also referred to as substrate concentration) during crystallization can be appropriately selected depending on the selectivity and yield of the cis isomer, but from the viewpoint of industrially suitable production, it is preferably 15 to 20 mass%.

[0054] <Metal Salt of Alicyclic Dicarboxylic Acid> The metal salt of alicyclic dicarboxylic acid produced by the method for producing a metal salt of alicyclic dicarboxylic acid of the present invention will now be described.

[0055] The metal salt of the alicyclic dicarboxylic acid is a metal salt of cyclohexane-1,2-dicarboxylic acid having at least one alkyl substituent directly bonded to the cyclohexane ring, the alkyl substituent being a linear or branched alkyl group having 1 to 4 carbon atoms, and the metal salt is a calcium salt, a hydroxyaluminum salt, a disodium salt, or a dilithium salt.

[0056] Examples of the linear or branched alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, etc. Among these, a methyl group or a tert-butyl group is preferred from the viewpoint of the crystallization-promoting effect when used as a crystal nucleating agent.

[0057] The position of the alkyl substituent is preferably the 3rd or 4th position of the cyclohexane ring, more preferably the 4th position, from the viewpoint of the crystallization-promoting effect when used as a crystal nucleating agent.

[0058] The metal salt is preferably a calcium salt from the viewpoint of the crystallization-promoting effect when used as a crystal nucleating agent.

[0059] Specific examples of the metal salts of the alicyclic dicarboxylic acids include the disodium salt of 3-methylcyclohexane-1,2-dicarboxylic acid, the calcium salt of 3-methylcyclohexane-1,2-dicarboxylic acid, the hydroxyaluminum salt of 3-methylcyclohexane-1,2-dicarboxylic acid, the dilithium salt of 3-methylcyclohexane-1,2-dicarboxylic acid, the disodium salt of 3-ethylcyclohexane-1,2-dicarboxylic acid, the calcium salt of 3-ethylcyclohexane-1,2-dicarboxylic acid, the Hydroxyaluminum salts, dilithium salt of 3-ethylcyclohexane-1,2-dicarboxylic acid, disodium salt of 3-n-propylcyclohexane-1,2-dicarboxylic acid, calcium salt of 3-n-propylcyclohexane-1,2-dicarboxylic acid, hydroxyaluminum salt of 3-n-propylcyclohexane-1,2-dicarboxylic acid, dilithium salt of 3-n-propylcyclohexane-1,2-dicarboxylic acid, disodium salt of 3-isopropylcyclohexane-1,2-dicarboxylic acid, 3-isopropylcyclohexane-1,2- calcium salts of dicarboxylic acids, hydroxyaluminum salt of 3-isopropylcyclohexane-1,2-dicarboxylic acid, dilithium salt of 3-isopropylcyclohexane-1,2-dicarboxylic acid, disodium salt of 3-n-butylcyclohexane-1,2-dicarboxylic acid, calcium salt of 3-n-butylcyclohexane-1,2-dicarboxylic acid, hydroxyaluminum salt of 3-n-butylcyclohexane-1,2-dicarboxylic acid, dilithium salt of 3-n-butylcyclohexane-1,2-dicarboxylic acid, 3-tert-butylcyclohexane disodium salt of 3-isobutylcyclohexane-1,2-dicarboxylic acid, calcium salt of 3-isobutylcyclohexane-1,2-dicarboxylic acid, hydroxyaluminum salt of 3-isobutylcyclohexane-1,2-dicarboxylic acid, dilithium salt of 3-isobutylcyclohexane-1,2-dicarboxylic acid, disodium salt of 4-methylcyclohexane-1,2-dicarboxylic acid, calcium salt of 4-methylcyclohexane-1,2-dicarboxylic acid, hydroxyaluminum salt of 4-methylcyclohexane-1,2-dicarboxylic acid,dilithium salt of 4-ethylcyclohexane-1,2-dicarboxylic acid, disodium salt of 4-ethylcyclohexane-1,2-dicarboxylic acid, calcium salt of 4-ethylcyclohexane-1,2-dicarboxylic acid, hydroxyaluminum salt of 4-ethylcyclohexane-1,2-dicarboxylic acid, dilithium salt of 4-ethylcyclohexane-1,2-dicarboxylic acid, disodium salt of 4-n-propylcyclohexane-1,2-dicarboxylic acid, calcium salt of 4-n-propylcyclohexane-1,2-dicarboxylic acid, hydroxyaluminum salt of 4-n-propylcyclohexane-1,2-dicarboxylic acid aluminum salt, dilithium salt of 4-n-propylcyclohexane-1,2-dicarboxylic acid, disodium salt of 4-isopropylcyclohexane-1,2-dicarboxylic acid, calcium salt of 4-isopropylcyclohexane-1,2-dicarboxylic acid, hydroxyaluminum salt of 4-isopropylcyclohexane-1,2-dicarboxylic acid, dilithium salt of 4-isopropylcyclohexane-1,2-dicarboxylic acid, disodium salt of 4-n-butylcyclohexane-1,2-dicarboxylic acid, calcium salt of 4-n-butylcyclohexane-1,2-dicarboxylic acid calcium salt, hydroxyaluminum salt of 4-n-butylcyclohexane-1,2-dicarboxylic acid, dilithium salt of 4-n-butylcyclohexane-1,2-dicarboxylic acid, disodium salt of 4-tert-butylcyclohexane-1,2-dicarboxylic acid, calcium salt of 4-tert-butylcyclohexane-1,2-dicarboxylic acid, hydroxyaluminum salt of 4-tert-butylcyclohexane-1,2-dicarboxylic acid, dilithium salt of 4-tert-butylcyclohexane-1,2-dicarboxylic acid, 4-isobutylcyclohexane-1,2 Examples of the dicarboxylic acid include the disodium salt of 4-isobutylcyclohexane-1,2-dicarboxylic acid, the calcium salt of 4-isobutylcyclohexane-1,2-dicarboxylic acid, the hydroxyaluminum salt of 4-isobutylcyclohexane-1,2-dicarboxylic acid, and the dilithium salt of 4-isobutylcyclohexane-1,2-dicarboxylic acid. Among these, preferred examples include the disodium salt of 3-methylcyclohexane-1,2-dicarboxylic acid, the calcium salt of 4-methylcyclohexane-1,2-dicarboxylic acid, and the calcium salt of 4-tert-butylcyclohexane-1,2-dicarboxylic acid.

[0060] In the metal salt of an alicyclic dicarboxylic acid, the molar ratio of cis isomers among stereoisomers of the alkyl substituent via the cyclohexane ring of the alicyclic dicarboxylic acid and the oxycarbonyl group constituting the metal salt is preferably 90.0% or more, more preferably 93.0% or more, even more preferably 95.0% or more, particularly preferably 97.0% or more, and most preferably 99.0% or more, from the viewpoint of the crystallization-promoting effect when used as a crystal nucleating agent.

[0061] The present specification discloses the following:

[0062] The present disclosure (1) is a method for producing a metal salt of an alicyclic dicarboxylic acid, wherein the alicyclic dicarboxylic acid is a metal salt of cyclohexane-1,2-dicarboxylic acid having at least one alkyl substituent directly bonded to the cyclohexane ring, the alkyl substituent being a linear or branched alkyl group having 1 to 4 carbon atoms, and the metal salt is a calcium salt, a hydroxyaluminum salt, a disodium salt, or a dilithium salt, and the method comprises the following steps (1) and (2): Step (1): A step of obtaining an alkali metal salt or an ammonium salt using cyclohexene-1,2-dicarboxylic anhydride having a linear or branched alkyl substituent having 1 to 4 carbon atoms or phthalic anhydride having a linear or branched alkyl substituent having 1 to 4 carbon atoms as a raw material. Step (2): A step of performing a hydrogenation reaction using the alkali metal salt or ammonium salt obtained in the above step (1). Disclosure (2) is a method for producing a metal salt of an alicyclic dicarboxylic acid according to Disclosure (1), in which the alkali metal salt in the above step (1) is at least one selected from the group consisting of a sodium salt, a potassium salt, and a lithium salt. Disclosure (3) is a method for producing a metal salt of an alicyclic dicarboxylic acid according to Disclosure (2), in which the alkali metal salt in the above step (1) is a sodium salt. The present disclosure (4) is a method for producing a metal salt of an alicyclic dicarboxylic acid according to any one of the present disclosures (1) to (3), wherein the catalyst for the hydrogenation reaction in the step (2) is at least one selected from the group consisting of palladium, rhodium, and ruthenium. The present disclosure (5) is a method for producing a metal salt of an alicyclic dicarboxylic acid according to any one of the present disclosures (1) to (4), wherein the temperature for the hydrogenation reaction in the step (2) is 80°C or lower. The present disclosure (6) is a method for producing a metal salt of an alicyclic dicarboxylic acid according to any one of the present disclosures (1) to (5), further comprising the following step (3): Step (3): Converting the hydrogenated alkali metal salt or ammonium salt obtained in the step (2) into a calcium salt or a disodium salt. The present disclosure (7) is a method for producing a metal salt of an alicyclic dicarboxylic acid according to any one of the present disclosures (1) to (6), further comprising the following step (4) after the step (2).Step (4): Crystallizing the hydrogenated alkali metal salt or ammonium salt obtained in Step (2). The present disclosure (8) is the method for producing a metal salt of an alicyclic dicarboxylic acid according to the present disclosure (7), in which the alkali metal salt or ammonium salt crystallized in Step (4) is a monoalkali metal salt. The present disclosure (9) is the method for producing a metal salt of an alicyclic dicarboxylic acid according to any one of the present disclosures (1) to (8), in which the alkyl substituent is located at the 3rd or 4th position of the cyclohexane ring. The present disclosure (10) is the method for producing a metal salt of an alicyclic dicarboxylic acid according to any one of the present disclosures (1) to (9), in which the alkyl substituent is a methyl group. The present disclosure (11) is the method for producing a metal salt of an alicyclic dicarboxylic acid according to any one of the present disclosures (1) to (10), in which, among stereoisomers of the alkyl substituent via the cyclohexane ring of the alicyclic dicarboxylic acid and the oxycarbonyl group constituting the metal salt, the molar ratio of cis isomers is 90.0% or more. The present disclosure (12) is a method for producing a metal salt of an alicyclic dicarboxylic acid according to any one of the present disclosures (1) to (11), wherein the molar ratio of the cis isomer is 93.0% or more. The present disclosure (13) is a method for producing a metal salt of an alicyclic dicarboxylic acid according to the present disclosure (7) or (8), wherein the molar ratio of the cis isomer is 95.0% or more.

[0063] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. The abbreviations of the compounds in the examples and the methods for measuring the respective properties are as follows:

[0064] [Method for analyzing the obtained compounds] (1) Gas chromatography analysis (GC analysis) In each step, the molar ratio of the cis isomer among the stereoisomers of the alkyl substituents via the cyclohexane ring of the alicyclic dicarboxylic acid and the oxycarbonyl group constituting the metal salt was measured by GC analysis. The measurement conditions for GC analysis are as follows. In the case of the alicyclic dicarboxylic acid, the ring was closed with acetic anhydride and the measurement was performed as the acid anhydride. In the case of the metal salt or ammonium salt of the alicyclic dicarboxylic acid, the salt was converted back to an acid using concentrated hydrochloric acid, and then the ring was closed with acetic anhydride and the measurement was performed as the acid anhydride. <GC measurement conditions> Model: Gas chromatograph GC-2010 (Shimadzu Corporation) Detector: FID, 280°C Column: DB-1701 (60 m x 0.25 mmφ x 0.25 μm) Column temperature: 145°C Injection temperature: 280°C Carrier gas: Helium (linear velocity: 30 cm / sec) Injection volume: 0.1 μl (split ratio: 1 / 35)

[0065] After the GC analysis, the area ratio of each peak was calculated by the area percentage method, and the molar ratio of the cis isomer among the stereoisomers of the alkyl substituent via the cyclohexane ring in the metal salt of alicyclic dicarboxylic acid and the oxycarbonyl group constituting the metal salt was calculated by [(area ratio of cis isomer) / (area ratio of cis isomer + area ratio of trans isomer)] × 100. It was confirmed that the molar ratio of the cis isomer among the stereoisomers remained unchanged before and after the step of reacting the alicyclic dicarboxylic acid or its derivative [compound obtained in steps (2) or (4)] with a metal oxide, metal hydroxide, or metal chloride [compound obtained in step (3)] by comparing the results with those obtained by converting the obtained metal salt of alicyclic dicarboxylic acid back into an acid anhydride and performing the same measurement.

[0066] In the following examples and comparative examples, the molar ratio of the cis isomer was evaluated according to the following criteria: ⊚: 93% or more; ◯: 90% or more but less than 93%; ×: Less than 90%

[0067] Furthermore, it was confirmed by the following nuclear magnetic resonance spectroscopy that the compounds corresponding to each retention time were alicyclic dicarboxylic acid anhydrides or derivatives thereof, and that the isomeric structures thereof were cis isomers and trans isomers of the above stereoisomers.

[0068] (2) Nuclear Magnetic Resonance Spectroscopic Analysis (NMR Analysis) The structure of each isomer in the gas chromatography analysis was confirmed by nuclear magnetic resonance spectroscopic analysis (NMR analysis). The conditions for the NMR analysis are as follows: NMR analysis apparatus: trade name "DRX-500", manufactured by Bruker Solvent: deuterated dimethyl sulfoxide (DMSO-d6) Internal standard: tetramethylsilane (TMS) Sample tube: 5 mm １ H-NMR...resonance frequency: 500.1 MHz, number of accumulations: 4 １３ C-NMR...resonance frequency: 125.8 MHz, number of accumulations: 23. The measurement sample was prepared by diluting 30 mg of sample with 0.8 ml of solvent. The stereostructure of the isomers was determined by measuring HMBC, HHCOYS, HMQC, and NOESY.

[0069] (3) Infrared spectroscopy (IR analysis) FT-IR device: trade name "Spectrum One", manufactured by PerkinElmer, measurement range: 650 to 4000 cm －１ , Measurement method: ATR method, Number of integrations: 3 times, Resolution: 4.00cm －１ The measurement was performed by pressing the sample onto the cell of the device.

[0070] (4) Inductively Coupled Plasma Analysis (ICP Analysis) ICP Apparatus: Product Name "iCAP 6500Duo" manufactured by Thermo Fisher Scientific Spray Chamber: Cyclone Sprayer Plasma Conditions: Plasma / Auxiliary / Carrier = 15 / 1.0 / 0.6 Plasma Observation Direction: Axial Direction 3 Times The measurement was performed on a sample that had been pretreated using a microwave decomposition method. Microwave Apparatus: Multiwave PRO manufactured by Anton Paar Decomposition Conditions: Approximately 0.05 g of sample and 6 mL of nitric acid (special grade) were decomposed and then diluted with distilled water to prepare the sample.

[0071] Example 1 <Step (1)> A 500 mL four-neck flask equipped with a stirrer and a reflux condenser was charged with 6.0 g (150 mmol) of sodium hydroxide and 125 g of ion-exchanged water, and the mixture was stirred and mixed at room temperature to dissolve uniformly. Uniform dissolution was confirmed by visual inspection. Subsequently, 25 g (150 mmol) of 4-methyl-4-cyclohexene-1,2-dicarboxylic anhydride (also referred to as "4-MT," manufactured by New Japan Chemical Co., Ltd., product name "Rikacid MT") was added, and the mixture was stirred and mixed while heating to dissolve uniformly, thereby obtaining a 20% by mass aqueous solution of a metal salt (sodium salt) of 4-methyl-4-cyclohexene-1,2-dicarboxylic acid.

[0072] <Step (2)> In a 500 mL autoclave, 150 g of the aqueous metal salt solution of 4-methyl-4-cyclohexene-1,2-dicarboxylic acid having a concentration of 20% by mass (also referred to as the substrate concentration) obtained in the above step (1) and a palladium / alumina-supported catalyst ("Pd / Al") as a hydrogenation catalyst were placed. ２ O ３ ") was charged, and hydrogen substitution was carried out three times. Subsequently, the reaction was carried out for 1 hour at 60°C under a hydrogen atmosphere of 3 MPa (gauge pressure), and after completion of the reaction, the hydrogenation catalyst was removed by hot filtration. Thereafter, water was distilled off using an evaporator, and the resulting mixture was dried in vacuo at 80°C to obtain the monosodium salt of 4-methylcyclohexane-1,2-dicarboxylic acid. The molar ratio of cis isomers in the obtained monosodium salt of 4-methylcyclohexane-1,2-dicarboxylic acid was confirmed to be 93.5% by the GC analysis described above.

[0073] <Step (3)> A 500 mL four-neck flask equipped with a stirrer, a reflux condenser, and a dropping funnel was charged with 1.92 g (48 mmol) of sodium hydroxide and 225 g of ion-exchanged water, and the mixture was stirred and mixed at room temperature to achieve a uniform solution. After visually confirming that the solution had dissolved, 10 g (48 mmol) of the monosodium salt of 4-methylcyclohexane-1,2-dicarboxylic acid obtained in step (2) above was added, and the mixture was stirred and mixed until uniformly dissolved, yielding an aqueous solution of the disodium salt of 4-methylcyclohexane-1,2-dicarboxylic acid. The resulting aqueous solution was heated to 80°C, and 21.2 g of a separately prepared aqueous calcium chloride solution (an aqueous solution obtained by uniformly dissolving 6.2 g (48 mmol) of calcium chloride dihydrate in 15 g of ion-exchanged water) was added dropwise over 1 hour. During the dropwise addition of the aqueous calcium chloride solution, precipitation of a white solid was observed almost simultaneously with the dropwise addition. After the dropwise addition of the calcium chloride solution was completed, the temperature was raised to 80°C and the mixture was heated and stirred for an additional 1 hour and 30 minutes. The mixture was then filtered while hot, washed with a small amount of water, and vacuum dried at 150°C for 10 hours to obtain 10.3 g (yield 95.7%) of the target calcium salt of 4-methylcyclohexane-1,2-dicarboxylic acid. IR analysis and ICP analysis confirmed that the structure of the resulting compound was that of the target compound. Furthermore, the resulting calcium salt was back-acidified and subjected to GC analysis, confirming that the molar ratio of cis isomers was 93.5%.

[0074] (Examples 2 to 27) The type of acid anhydride, the type and amount of alkali metal hydroxide, and the amine (also referred to as alkali metal, etc.) used in step (1) were changed as shown in the table. In addition, the concentration of the aqueous solution of metal salt of 4-methyl-4-cyclohexene-1,2-dicarboxylic acid (also referred to as substrate concentration), the type and amount of catalyst, and reaction conditions (hydrogen pressure, reaction temperature, reaction time) used in step (2) were changed as shown in the table. Except for the above, calcium salt of 4-methylcyclohexane-1,2-dicarboxylic acid was prepared in the same manner as in Example 1.

[0075] In the above examples, the catalysts used in step (2) are as follows: <Catalyst> Palladium / carbon supported catalyst (also referred to as "Pd / C") Rhodium / alumina supported catalyst (also referred to as "Rh / Al") ２ O３ Ruthenium / alumina supported catalyst (also referred to as "Ru / Al") ２ O ３ ") For trimethylamine, "Me ３ N" for triethylamine, and "Et ３ Also written as "N".

[0076] (Examples 28 to 29) In step (1), 4-methyl-phthalic anhydride (also referred to as "4-MePA") was used instead of 4-methyl-4-cyclohexene-1,2-dicarboxylic anhydride, and the amounts of alkali metals and other ingredients were changed as shown in the table. In addition, the type of catalyst used in step (2) was changed as shown in the table. Except for the above, calcium salt of 4-methylcyclohexane-1,2-dicarboxylic acid was prepared in the same manner as in Example 1.

[0077] Example 30 In step (1), 3-methyl-4-cyclohexene-1,2-dicarboxylic anhydride (also referred to as "3-MT") was used instead of 4-methyl-4-cyclohexene-1,2-dicarboxylic anhydride, and the amounts of alkali metal and other ingredients were changed as shown in the table. In addition, the type of catalyst used in step (2) was changed as shown in the table. Except for the above, the calcium salt of 3-methylcyclohexane-1,2-dicarboxylic acid was prepared in the same manner as in Example 1.

[0078] Example 31 In step (1), 4-(1-propyl)phthalic anhydride (also referred to as "4-(1-Pr)PA") was used instead of 4-methyl-4-cyclohexene-1,2-dicarboxylic anhydride, and the amounts of alkali metals and the like were changed as shown in the table. Except for the above, the calcium salt of 4-(1-propyl)cyclohexane-1,2-dicarboxylic acid was prepared in the same manner as in Example 1.

[0079] Example 32 In step (1), 4-t-butylphthalic anhydride (also referred to as "4-t-BuPA") was used instead of 4-methyl-4-cyclohexene-1,2-dicarboxylic anhydride, and the amounts of alkali metals and other ingredients were changed as shown in the table. Except for the above, the calcium salt of 4-t-butylcyclohexane-1,2-dicarboxylic acid was prepared in the same manner as in Example 1.

[0080] (Comparative Examples 1 to 3) Step (1) was omitted, and an aqueous solution of 4-methyl-4-cyclohexene-1,2-dicarboxylic acid (substrate concentration: 5% by mass) was used in step (2). In step (2), the type of catalyst was changed as shown in the table. Other than the above, the same procedures as in Example 1 were carried out.

[0081] (Comparative Example 4) Step (1) was omitted, and 4-methyl-4-cyclohexene-1,2-dicarboxylic anhydride (substrate concentration 100% by mass) was used. 150 g of 4-MT and 1.5 g of a palladium catalyst (1% by mass relative to the substrate) as a hydrogenation catalyst were charged into a 500 mL autoclave, and hydrogen substitution was performed three times. Subsequently, the reaction was carried out at 150°C for 5 hours under a hydrogen atmosphere of 3 MPa (gauge pressure), and after completion of the reaction, the hydrogenation catalyst was removed by hot filtration. In step (2), the reaction conditions (reaction temperature) were changed as shown in the table. Other than the above, the same procedures as in Example 1 were carried out.

[0082]

[0083]

[0084] Example 33 Steps (1) and (2) were carried out in the same manner as in Example 1. <Step (4)> The monosodium salt of 4-methylcyclohexane-1,2-dicarboxylic acid obtained in step (2) above was dissolved in water heated to 60°C to prepare an aqueous solution with a substrate concentration of 20% by mass. Next, the aqueous solution was slowly cooled to 30°C to crystallize the cis isomer of the monosodium salt of 4-methylcyclohexane-1,2-dicarboxylic acid. Thereafter, the solution was subjected to suction filtration, washed with a small amount of water to obtain a wet crystal, and then vacuum dried at 80°C to obtain a crystal. In addition, the filtrate obtained by suction filtration was concentrated and crystallized again in the same manner to obtain a crystal.

[0085] <Step (3)> A 500 mL four-neck flask equipped with a stirrer, a reflux condenser, and a dropping funnel was charged with 1.92 g (48 mmol) of sodium hydroxide and 225 g of ion-exchanged water, and the mixture was stirred and mixed at room temperature to achieve a uniform solution. After visually confirming that the solution had dissolved, 10 g (48 mmol) of the monosodium salt crystals of 4-methylcyclohexane-1,2-dicarboxylic acid obtained in step (4) above was added, and the mixture was stirred and mixed until a uniform solution was obtained, thereby obtaining an aqueous solution of the disodium salt of 4-methylcyclohexane-1,2-dicarboxylic acid. The temperature of the resulting aqueous solution was raised to 80°C, and 21.2 g of a separately prepared aqueous calcium chloride solution (an aqueous solution obtained by uniformly dissolving 6.2 g (48 mmol) of calcium chloride dihydrate in 15 g of ion-exchanged water) was added dropwise over 1 hour. During the dropwise addition of the aqueous calcium chloride solution, precipitation of a white solid was observed almost simultaneously with the dropwise addition. After the dropwise addition of the calcium chloride aqueous solution was completed, the temperature was raised to 80°C and the mixture was heated and stirred for an additional 1 hour and 30 minutes. The mixture was then filtered while hot, washed with a small amount of water, and vacuum dried at 150°C for 10 hours to obtain 10.3 g (yield 95.7%) of the target calcium salt of 4-methylcyclohexane-1,2-dicarboxylic acid. IR analysis and ICP analysis confirmed that the structure of the resulting compound was that of the target compound. Furthermore, the resulting calcium salt was back-acidified and subjected to GC analysis, confirming that the molar ratio of cis isomers was 99.9% or higher.

[0086] From the examples, it was confirmed that by including step (1) of obtaining an alkali metal salt or an ammonium salt using cyclohexene-1,2-dicarboxylic anhydride having a linear or branched alkyl substituent having 1 to 4 carbon atoms or phthalic anhydride having a linear or branched alkyl substituent having 1 to 4 carbon atoms as raw materials, and step (2) of carrying out a hydrogenation reaction using the alkali metal salt or ammonium salt obtained in step (1), it is possible to reduce waste and to obtain a metal salt of an alicyclic dicarboxylic acid having a high molar ratio of cis isomer.

[0087] The present invention provides a method for producing metal salts of alicyclic dicarboxylic acids (calcium salts, hydroxyaluminum salts, disodium salts, or dilithium salts of alkyl-substituted 1,2-dicarboxylic acids) simply and with excellent selectivity (molar ratio of cis isomers), while reducing waste. Metal salts of alicyclic dicarboxylic acids (calcium salts, hydroxyaluminum salts, disodium salts, or dilithium salts of alkyl-substituted 1,2-dicarboxylic acids) have excellent properties as crystal nucleating agents for polyolefin-based resins and the like. For example, they can significantly improve the crystallization rate, i.e., the crystallization temperature, of thermoplastic resins such as polyolefin-based resins, thereby significantly shortening the molding cycle, particularly for large components, and are extremely useful for reducing costs and preventing processing problems. Furthermore, improving the degree of crystallization not only improves the mechanical properties, such as rigidity, and thermal properties, such as heat resistance, of the resulting molded articles, but also reduces sink marks and warpage, enabling the stable production of molded articles with complex shapes.

Claims

1. A method for producing a metal salt of an alicyclic dicarboxylic acid, wherein the alicyclic dicarboxylic acid is a metal salt of cyclohexane-1,2-dicarboxylic acid having at least one alkyl substituent directly bonded to the cyclohexane ring, the alkyl substituent being a linear or branched alkyl group having 1 to 4 carbon atoms, and the metal salt being a calcium salt, hydroxyaluminum salt, disodium salt, or dilithium salt, the method comprising the following steps (1) and (2): Step (1): Obtaining an alkali metal salt or ammonium salt using cyclohexene-1,2-dicarboxylic anhydride having a linear or branched alkyl substituent having 1 to 4 carbon atoms or phthalic anhydride having a linear or branched alkyl substituent having 1 to 4 carbon atoms as a raw material; and Step (2): Performing a hydrogenation reaction using the alkali metal salt or ammonium salt obtained in Step (1).

2. The method for producing a metal salt of an alicyclic dicarboxylic acid according to claim 1, wherein the alkali metal salt in step (1) is at least one selected from the group consisting of sodium salts, potassium salts, and lithium salts.

3. The method for producing a metal salt of an alicyclic dicarboxylic acid according to claim 2, wherein the alkali metal salt in step (1) is a sodium salt.

4. The method for producing a metal salt of an alicyclic dicarboxylic acid according to any one of claims 1 to 3, wherein the catalyst for the hydrogenation reaction in step (2) is at least one selected from the group consisting of palladium, rhodium, and ruthenium.

5. The method for producing a metal salt of an alicyclic dicarboxylic acid according to any one of claims 1 to 3, wherein the temperature of the hydrogenation reaction in step (2) is 80°C or lower.

6. The method for producing a metal salt of an alicyclic dicarboxylic acid according to any one of claims 1 to 3, further comprising the following step (3): converting the hydrogenated alkali metal salt or ammonium salt obtained in step (2) into a calcium salt, hydroxyaluminum salt, disodium salt, or dilithium salt.

7. The method for producing a metal salt of an alicyclic dicarboxylic acid according to claim 1 or 2, further comprising the following step (4) after step (2): Step (4): A step of crystallizing the hydrogenated alkali metal salt or ammonium salt obtained in step (2).

8. The method for producing a metal salt of an alicyclic dicarboxylic acid according to claim 7, wherein the alkali metal salt or ammonium salt crystallized in step (4) is a monoalkali metal salt.

9. The method for producing a metal salt of an alicyclic dicarboxylic acid according to any one of claims 1 to 3, wherein the alkyl substituent is at the 3rd or 4th position of the cyclohexane ring.

10. The method for producing a metal salt of an alicyclic dicarboxylic acid according to any one of claims 1 to 3, wherein the alkyl substituent is a methyl group.

11. The method for producing a metal salt of an alicyclic dicarboxylic acid according to any one of claims 1 to 3, wherein, among stereoisomers of the alkyl substituent via the cyclohexane ring of the alicyclic dicarboxylic acid and the oxycarbonyl group constituting the metal salt, the molar ratio of cis isomers is 90.0% or more.

12. The method for producing a metal salt of an alicyclic dicarboxylic acid according to claim 11, wherein the molar ratio of the cis isomer is 93.0% or more.

13. A method for producing a metal salt of an alicyclic dicarboxylic acid according to claim 7, wherein, among stereoisomers of the alkyl substituent via the cyclohexane ring of the alicyclic dicarboxylic acid and the oxycarbonyl group constituting the metal salt, the molar ratio of cis isomers is 95.0% or more.

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