Method for producing lactam compounds, lactam compounds, polyamides, polyamide products, and polyamide-containing products

Abstract

To obtain lactam compounds in high yield while reducing energy costs during the manufacturing process. [Solution] A method for producing a lactam compound, comprising steps (i) and (ii) in that order. Step (i): A step in which an aminocarboxylic acid and a conjugated ketone compound are mixed and a preliminary reaction is carried out to form an imine compound. Step (ii): A step in which the imine compound obtained in step (i) is reacted at a reaction temperature higher than the reaction temperature in step (i) to form a lactam compound represented by a specific chemical formula.

Description

[Technical Field]

[0001] The present invention relates to a method for producing lactam compounds, lactam compounds, polyamides, polyamide processed products, and polyamide-containing products. [Background technology]

[0002] Polyamide (nylon) is known as a polymer with excellent lightness, strength, heat resistance, elasticity, and dyeability. There are many types of polyamide, such as nylon 4, nylon 6, nylon 66, nylon 610, and nylon 12, and they are used in various applications such as textiles, medical supplies, and industrial materials depending on their properties.

[0003] Among polyamides, nylon 4, nylon 6, and nylon 12 are polyamides composed primarily of a single monomer. The raw materials for these polyamides are lactam compounds, but traditionally, the production of lactam compounds has required a lot of energy. For example, γ-butyrolactam, the raw material for nylon 4, is produced by the addition of ammonia to γ-butyrolactone, but this reaction proceeds only under high temperature and high pressure conditions. Against this backdrop, in recent years, with growing awareness of global environmental issues, there has been a widespread demand for methods to produce lactam compounds in high yield while reducing energy costs during production.

[0004] To reduce energy costs during manufacturing, it is effective to lower the reaction temperature, shorten the reaction time, and bring the reaction pressure closer to atmospheric pressure. In other words, it is effective to carry out the reaction under the mildest possible conditions.

[0005] Patent Document 1 describes a method for continuously producing γ-butyrolactam by reacting γ-butyrolactone with ammonia in a liquid phase in the presence of water.

[0006] Non-patent document 1 describes a method for obtaining γ-butyrolactam by heating and cyclizing glutamic acid to convert it to pyroglutamic acid, followed by a decarboxylation reaction using a ruthenium catalyst.

[0007] Non-Patent Document 2 describes that γ-butyrolactam is produced by heating glutamic acid in the presence of a conjugated ketone compound.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Non-Patent Documents

[0009]

Non-Patent Document 1

Non-Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0010] The method described in Patent Document 1 is an industrial production method of γ-butyrolactam. Although the yield is high, it is necessary to carry out the reaction at a high temperature of about 300°C and under a pressure more than 100 times that of atmospheric pressure, so the energy cost during production is high.

[0011] The method described in Non-Patent Document 1 is a mild reaction using a metal catalyst. Although the energy cost during production is low, the yield of γ-butyrolactam is insufficient.

[0012] The method described in Non-Patent Document 2 can shorten the heating-up time and complete the reaction in a short time by using microwaves. However, since many by-products are generated, the yield of γ-butyrolactam is insufficient.

[0013] The present invention aims to improve upon these drawbacks and obtain lactam compounds in high yield while reducing energy costs during manufacturing. [Means for solving the problem]

[0014] As a result of diligent research to solve the above problems, the inventors of the present invention have found that it is possible to obtain lactam compounds in high yield while suppressing energy costs during production by the following manufacturing method, and have completed the present invention. That is, the present invention has the following configuration. [1] A method for producing a lactam compound, comprising steps (i) and (ii) in that order. Step (i): A step in which an aminocarboxylic acid and a conjugated ketone compound are mixed and a preliminary reaction is carried out to form an imine compound. Step (ii): A step in which the imine compound obtained in step (i) is reacted at a reaction temperature higher than the reaction temperature in step (i) to form a lactam compound represented by formula (I).

[0015] [ka]

[0016] (In formula (I), R, R', R'', R n1 , R n2 Each of these is a functional group consisting of hydrogen, an alkyl group with 1 to 6 carbon atoms, a phenyl group, a cycloalkyl group with 3 to 9 carbon atoms, or a combination thereof. n is a natural number between 1 and 11 (inclusive). [2] A method for producing the lactam compound described in [1] above, wherein the aminocarboxylic acid is a compound represented by formula (II).

[0017] [ka]

[0018] (In formula (II), R m1 , R m2 , R m3Each of these is a functional group consisting of hydrogen, an alkyl group with 1 to 6 carbon atoms, a phenyl group, a cycloalkyl group with 3 to 9 carbon atoms, or a combination thereof. m is a natural number between 1 and 11. X and Y are atoms selected from hydrogen, sodium, potassium, and calcium, respectively. [3] A method for producing a lactam compound according to [1] or [2] above, wherein the ratio of the number of moles of the conjugated ketone compound to the number of moles of the aminocarboxylic acid (number of moles of conjugated ketone compound / number of moles of aminocarboxylic acid) is 0.1 or more and 10 or less. [4] A method for producing a lactam compound according to any one of [1] to [3] above, wherein the reaction temperature in step (i) is 10°C or more and 200°C or less, and the reaction temperature in step (ii) is 70°C or more and 270°C or less. [5] A lactam compound obtained by a method for producing a lactam compound described in any of [1] to [4] above. [6] A polyamide obtained by polymerizing a raw material containing the lactam compound described in [5] above. [7] A polyamide product obtained by processing the polyamide described in [6] above. [8] A polyamide-containing product comprising the polyamide described in [6] above, or the polyamide processed product described in [7] above. [Effects of the Invention]

[0019] According to the present invention, lactam compounds can be obtained in high yield while reducing energy costs during manufacturing. The obtained lactam compounds can be suitably used as raw materials for pharmaceuticals, solvents, polymers, and the like. [Modes for carrying out the invention]

[0020] The present invention will be described in detail below.

[0021] The present invention provides a method for producing a lactam compound, comprising steps (i) and (ii) in that order. Step (i): A step in which an aminocarboxylic acid and a conjugated ketone compound are mixed and a preliminary reaction is carried out to form an imine compound. Step (ii): reacting the imine compound obtained in step (i) at a reaction temperature higher than the reaction temperature in step (i) to form a lactam compound represented by formula (I).

[0022]

Chemical formula

[0023] In formula (I), R, R’, R”, R n1 , R n2 are each a functional group consisting of hydrogen, an alkyl group having 1 to 6 carbon atoms, a phenyl group, a cycloalkyl group having 3 to 9 carbon atoms, or a combination thereof. n is a natural number of 1 or more and 11 or less.

[0024] (Step (i)) Step (i) in the present invention is a step of mixing an aminocarboxylic acid and a conjugated ketone compound to perform a preliminary reaction to form an imine compound. Here, the preliminary reaction is a reaction of chemically reacting an aminocarboxylic acid and a conjugated ketone compound to convert them into an imine compound, which is a reaction intermediate that easily forms a lactam compound. The imine compound is a compound having a chemical structure represented by formula (III) in the molecule, and is formed by the reaction of the amino group of the aminocarboxylic acid and the carbonyl structure of the conjugated ketone compound.

[0025]

Chemical formula

[0026] Here, R l1 is a structure derived from the aminocarboxylic acid, and R l2 and R l3 are structures derived from the conjugated ketone compound.

[0027] By performing the lactam formation reaction in step (ii) after this preliminary reaction, i.e., by adopting a multi-step reaction mode, the activation energy of the lactam formation reaction is reduced, making it possible to form the lactam compound at a lower reaction temperature and in a shorter time. As a result, it is possible to reduce the energy cost of producing the lactam compound compared to conventional methods. In addition, by using a reaction intermediate that is easily converted to the lactam compound, a high yield can also be achieved.

[0028] Generally, the energy E required to carry out a chemical reaction is equal to the energy E required to raise the temperature from the initial state to the desired temperature. i and the energy E required to maintain the temperature during the reaction m It is expressed as the sum of E. In an insulated system that does not consider heat loss, E m E becomes 0, and E is E i This matches E i This can be calculated by the product of three parameters: the specific heat and mass of the object to be heated, and the temperature difference before and after heating. i By dividing by the reaction time, the energy efficiency E e (Unit: W) is derived. e E represents the energy required to carry out a certain reaction per unit time. e This allows us to compare the energy costs of different reactions.

[0029] The reaction temperature for the preliminary reaction is preferably 10°C to 200°C when isophorone is used as the conjugated ketone compound. More preferably 10°C to 150°C, even more preferably 10°C to 100°C, and particularly preferably 10°C to 50°C. By carrying out the preliminary reaction at such temperatures, the formation of by-products is suppressed, making it easier to obtain the imine compound, which is the reaction intermediate, and thus the yield of the lactam compound tends to increase.

[0030] The reaction time for the preliminary reaction is preferably 5 minutes to 180 minutes, for example, when isophorone is used as the conjugated ketone compound. More preferably, it is 10 minutes to 180 minutes, even more preferably 10 minutes to 120 minutes, and particularly preferably 10 minutes to 60 minutes. By carrying out the preliminary reaction for such a time, sufficient time is ensured to form the reaction intermediate, and unnecessary reaction time is avoided, resulting in a good balance between energy cost and yield.

[0031] Step (i) is preferably carried out under an inert gas atmosphere. This is to prevent moisture present in the atmosphere from reacting with the imine compound and causing the equilibrium reaction between the reaction intermediate and the raw material to be biased towards the raw material side. As the inert gas, for example, nitrogen gas, helium gas, or argon gas can be used, but nitrogen gas is preferred from the viewpoint of cost and ease of handling. Furthermore, the reaction is preferably carried out at atmospheric pressure, i.e., 1 atmosphere. This makes it easier to suppress unnecessary increases in energy costs associated with pressurization or depressurization.

[0032] Existing chemical reaction processes can be used to carry out the preliminary reaction. For example, a batch method in which aminocarboxylic acid and conjugated ketone compounds are added to glass or stainless steel reaction vessels and reacted, a flow method in which aminocarboxylic acid and conjugated ketone compounds are dissolved in a solvent and the reaction is carried out continuously while being pumped, or a microwave method in which the reaction is carried out instantaneously using microwaves can be selected.

[0033] Existing analytical methods can be selected to check the progress of the preliminary reaction. For example, when using infrared spectroscopy (IR), the wavenumber 3300 cm² originating from the amino group of the aminocarboxylic acid can be used. -1 From 3500cm -1 This can be confirmed by the disappearance of nearby peaks.

[0034] (Step (ii)) Step (ii) in the present invention is a step in which the imine compound obtained in step (i) is reacted at a higher temperature than in step (i) to form a lactam compound represented by the above formula (I). In the prior art, only the step corresponding to step (ii) was performed without performing step (i), so it was necessary to carry out the reaction at a high temperature in order to exceed the activation energy required to form the lactam structure.

[0035] As described above, the reaction temperature of step (ii) in the present invention is higher than the reaction temperature of step (i). Preferably, the reaction temperature of step (ii) is 1°C or more higher than the reaction temperature of step (i), more preferably 5°C or more higher, even more preferably 10°C or more higher, and particularly preferably 30°C or more higher.

[0036] The reaction temperature in step (ii) is preferably 70°C to 270°C when isophorone is used as the conjugated ketone compound. More preferably, it is 80°C to 230°C, and even more preferably 90°C to 200°C. By carrying out the reaction at such temperatures, the formation of by-products can be suppressed and the reaction can be completed in a short time, which tends to result in an excellent balance between energy cost and yield.

[0037] The reaction time in step (ii) is preferably 10 minutes to 180 minutes, for example, when isophorone is used as the conjugated ketone compound. More preferably, it is 10 minutes to 120 minutes, even more preferably 30 minutes to 120 minutes, and particularly preferably 60 minutes to 120 minutes. Performing step (ii) for this amount of time ensures sufficient time for the formation of the lactam compound, and avoids unnecessary reaction time, resulting in a good balance between energy cost and yield.

[0038] Step (ii) is preferably carried out under an inert gas atmosphere. This is to prevent moisture present in the atmosphere from reacting with the imine compound and causing the equilibrium reaction between the reaction intermediate and the raw material to be biased towards the raw material side. As the inert gas, for example, nitrogen gas, helium gas, or argon gas can be used, but nitrogen gas is preferred from the viewpoint of cost and ease of handling. Furthermore, the reaction is preferably carried out at atmospheric pressure, i.e., 1 atmosphere. This makes it easier to suppress unnecessary increases in energy costs associated with pressurization or depressurization.

[0039] As for the method of carrying out step (ii), an existing chemical reaction process can be adopted. For example, one can choose from a batch method in which aminocarboxylic acid and conjugated ketone compound are introduced into a glass or stainless steel reaction vessel and reacted, a flow method in which aminocarboxylic acid and conjugated ketone compound are dissolved in a solvent and the reaction is carried out continuously while being pumped, or a microwave method in which the reaction is carried out instantaneously using microwaves.

[0040] (Lactam compounds) The lactam compound in the method for producing the lactam compound of the present invention is a lactam compound represented by formula (I).

[0041] [ka]

[0042] Here, R, R', R'', R n1 , R n2 Each of these is a functional group consisting of hydrogen, an alkyl group having 1 to 6 carbon atoms, a phenyl group, a cycloalkyl group having 3 to 9 carbon atoms, or a combination thereof. n is a natural number between 1 and 11. Preferably, n is a natural number between 2 and 11, and more preferably a natural number between 2 and 5.

[0043] Furthermore, the lactam compound of the present invention can be obtained by the method for producing the lactam compound of the present invention.

[0044] Examples of lactam compounds in the present invention include β-propiolactam, γ-butyrolactam, δ-valerolactam, ε-caprolactam, and ω-laurolactam.

[0045] (aminocarboxylic acid) The aminocarboxylic acid in this invention is a compound having at least one carboxylate salt structure resulting from the reaction of at least one amino group and at least one carboxyl group, or a carboxyl group and a basic compound, within its molecule. Such an aminocarboxylic acid is not particularly limited as long as it is a compound that reacts with a conjugated ketone compound to form a lactam compound. Furthermore, the aminocarboxylic acid in this invention may be a product derived from petroleum raw materials or a product derived from bio-raw materials, but from the viewpoint of reducing environmental impact, it is preferable to use a product derived from bio-raw materials.

[0046] Examples of aminocarboxylic acids that are preferably used in the present invention include amino acids such as α-amino acids and β-amino acids and their carboxylate salts, compounds in which an amino group is bonded to the side chain of a fatty acid compound and their carboxylate salts, compounds in which an amino group is bonded to the side chain of a dicarboxylic acid compound and their carboxylate salts, and compounds in which a carboxyl group is bonded to the side chain of a diamino compound and their carboxylate salts. These aminocarboxylic acids may be used individually or in combination of multiple types.

[0047] Examples of amino acids in the present invention include alanine, proline, glutamine, glutamic acid, aspartic acid, arginine, lysine, β-alanine, 3-aminopropionic acid, 3-aminobutanoic acid, 3-aminopentanoic acid, γ-aminobutyric acid, and δ-aminovaleric acid. Examples of carboxylate salts of amino acids in the present invention include compounds obtained by reacting the above amino acids with sodium hydroxide, potassium hydroxide, calcium hydroxide, etc.

[0048] Examples of compounds in which an amino group is bonded to the side chain of a fatty acid compound in the present invention include ε-aminocaproic acid, 7-aminoenanthic acid, 8-aminocaprylic acid, 9-aminopelargonic acid, and 12-aminolauric acid. Furthermore, examples of carboxylate salts of compounds in which an amino group is bonded to the side chain of a fatty acid compound in the present invention include compounds obtained by reacting the above-mentioned compounds in which an amino group is bonded to the side chain of a fatty acid compound with sodium hydroxide, potassium hydroxide, calcium hydroxide, etc.

[0049] Examples of compounds in which an amino group is bonded to the side chain of a dicarboxylic acid compound in the present invention include 2-aminoadipic acid, 2-aminopimelic acid, 2-aminosuberic acid, 2-aminononannodiic acid, and 2-aminododecanoic acid dioate. Furthermore, examples of carboxylate salts of compounds in which an amino group is bonded to the side chain of a dicarboxylic acid compound in the present invention include compounds obtained by reacting a compound in which an amino group is bonded to the side chain of the above fatty acid compound with sodium hydroxide, potassium hydroxide, calcium hydroxide, etc.

[0050] Examples of compounds in which a carboxyl group is bonded to the side chain of a diamino compound in the present invention include 2,3-diaminopropionic acid and ornithine. Examples of carboxylate salts of compounds in which a carboxyl group is bonded to the side chain of a diamino compound in the present invention include compounds obtained by reacting the above-mentioned compounds in which a carboxyl group is bonded to the side chain of a diamino compound with sodium hydroxide, potassium hydroxide, calcium hydroxide, etc.

[0051] The aminocarboxylic acid is preferably a compound represented by formula (II), and more preferably a compound selected from glutamic acid or a salt obtained by the reaction of glutamic acid with a basic compound.

[0052] [ka]

[0053] Here, R m1 , R m2, R m3 Each of these is a functional group consisting of hydrogen, an alkyl group having 1 to 6 carbon atoms, a phenyl group, a cycloalkyl group having 3 to 9 carbon atoms, or a combination thereof. m is a natural number between 1 and 11. Preferably, m is a natural number between 2 and 11, and more preferably between 2 and 5. Also, X and Y are atoms selected from hydrogen, sodium, potassium, and calcium, respectively.

[0054] Using such aminocarboxylic acids tends to result in higher yields of the resulting lactam compounds. Although the exact reasons for this high yield are unclear, it is presumed that these aminocarboxylic acids have a high ability to eliminate low-molecular-weight compounds produced during the reaction, causing the reaction equilibrium to shift towards the lactam compound side.

[0055] (Conjugated ketone compounds) The conjugated ketone compounds in this invention are compounds having at least one pair of alkene and ketone structures within the molecule, and having an α,β-unsaturated carbonyl structure in which the alkene and ketone structures constitute a conjugated system. Such compounds may also be called by names other than conjugated ketone compounds, such as enone compounds or conjugated carbonyl compounds. Such conjugated ketone compounds are not particularly limited as long as they react with aminocarboxylic acids to form lactam compounds. Furthermore, they may be linear conjugated ketone compounds in which the alkene structure is located on a linear chain, or cyclic conjugated ketone compounds in which the alkene structure is incorporated into a ring structure. In the method for producing lactam compounds of this invention, the conjugated ketone compounds may be used individually or in combination of multiple types.

[0056] Examples of linear conjugated ketone compounds in the present invention include (E)-4-hexen-3-one, 3-methyl-3-penten-2-one, 4-methyl-3-penten-2-one, and 3-octen-2-one. Examples of cyclic conjugated ketone compounds in the present invention include 2-cyclopenten-1-one, dihydrojasmon, 2-cyclohexen-1-one, 3-methyl-2-cyclohexen-1-one, carvone, isophorone, piperitone, and 2-cyclohepten-1-one.

[0057] The conjugated ketone compound in the present invention preferably includes a cyclic conjugated ketone compound. More preferably, it includes a cyclic conjugated ketone compound having a 2-cyclohexen-1-one skeleton, and even more preferably, it includes an isophorone. When the conjugated ketone compound satisfies the above conditions, the yield of the resulting lactam compound tends to be high. While the detailed reasons for the high yield are not clear, it is presumed that the electron density of the conjugated ketone structure and the steric hindrance due to substituents play a role.

[0058] In the method for producing lactam compounds of the present invention, it is preferable that the ratio of the number of moles of the conjugated ketone compound to the number of moles of aminocarboxylic acid (moles of conjugated ketone compound / moles of aminocarboxylic acid; hereinafter sometimes referred to as the conjugated ketone equivalent) is 0.1 or more and 10 or less. More preferably, the conjugated ketone equivalent is 0.5 or more and 8.0 or less, even more preferably 1.0 or more and 6.0 or less, and particularly preferably 2.0 or more and 4.0 or less. By keeping the conjugated ketone equivalent within this range, a sufficient amount of reaction intermediate is more easily formed when the preliminary reaction is carried out in step (i), so that the yield of the resulting lactam compound tends to be high. In addition, side reactions of the conjugated ketone compound itself can be suppressed, making it easier to simplify the purification process of the lactam compound and reduce the associated energy costs.

[0059] (Additives) In the present invention, additives may be included to the extent that the effects of the invention are not lost. Examples of additives include solvents, dehydrating agents, and catalysts. In particular, it is preferable to include a solvent from the viewpoint that the contact area between the aminocarboxylic acid and the conjugated ketone compound will be increased and the thermal conductivity will be improved, which is expected to lead to a decrease in reaction temperature and a shortening of reaction time. The solvent is not particularly limited as long as it is a liquid compound in steps (i) and (ii), but it is preferable to include a solvent that does not have nucleophilic properties. By using such a compound as a solvent, the thermal conductivity can be increased without decomposing the imine compound, which is a reaction intermediate, so that step (i) can be completed in a shorter time.

[0060] Examples of non-nucleophilic solvents in the present invention include hexane, octane, benzene, toluene, xylene, tetrahydrofuran, acetonitrile, N,N'-dimethylformamide, dimethyl sulfoxide, γ-butyrolactam, N-methyl-2-pyrrolidone, mineral oil, silicone oil, and liquid paraffin. In the present invention, it is more preferable to use compounds with a molecular weight of 200 g / mol or less among these solvents.

[0061] (polyamide) The polyamide of the present invention is obtained by polymerizing a raw material containing the lactam compound of the present invention. The lactam compound in the present invention can be used as a raw material monomer for various polyamides. The method for producing the polyamide using the lactam compound is not particularly limited, and existing polymerization methods for lactam compounds can be employed. For example, methods include polymerization by adding water, an amine compound, a carboxylic acid compound, or salts thereof, or polymerization by dissolving the lactam compound in a solvent beforehand or by reacting it with an alkaline catalyst or co-catalyst in a suspended dispersion state. Furthermore, when producing the polyamide, in addition to the lactam compound of the present invention, additives such as heat resistance improvers, chain length extenders, and flexibility improvers may be added to appropriately adjust the physical properties and handling characteristics of the resulting polyamide according to its application.

[0062] (Polyamide processed material) The polyamide processed product of the present invention is obtained by processing the polyamide of the present invention. The polyamide of the present invention may be used after being processed into polyamide processed products such as particles, fibers, films, or molded articles. In this case, the method of processing the polyamide is not particularly limited.

[0063] For example, when using the polyamide as particles, it can be atomized by the method described in International Publication WO2022 / 113993 and used for various particle applications such as cosmetics and coatings like toners and inks.

[0064] Furthermore, when using the polyamide as a fiber, for example, molten polyamide can be extruded from a spinneret, cooled to solidify, and then used as a thread-like processed product. The fibers obtained in this way are suitable for various fiber applications, such as clothing, fishing nets, and medical applications.

[0065] When using the polyamide as a film, the film can be manufactured by continuous molding methods such as casting with a die called a T-die, or by inflation molding. The film obtained in this way is suitable for various film applications, including packaging, agricultural, and electrical / electronic applications.

[0066] When using polyamide as a molded product, it can be manufactured by methods such as press molding using a mold and press, injection molding in which resin is poured into a mold under pressure, or 3D printing in which finely particulated polyamide is laid out and molded by melting it with a laser. The molded products obtained in this way are suitable for various applications such as structures, automobile parts, and industrial machinery parts.

[0067] (Products containing polyamide) The polyamide-containing products of the present invention include the polyamide of the present invention or the polyamide processed product of the present invention. The polyamide or polyamide processed product in the present invention may be used as a polyamide-containing product obtained in combination with other materials or raw materials. Examples of polyamide-containing products include cosmetics such as foundations obtained by mixing with oil components or alcohol components, composite resin materials obtained by mixing with other resin compositions, and reinforced resin materials obtained by mixing with fibers or fillers. [Examples]

[0068] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the descriptions in these examples.

[0069] <Ingredients used> • Aminocarboxylic acid (A) L-Glutamine (manufactured by Tokyo Chemical Industry Co., Ltd.) (B) D-2-aminoadipic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) (C-1) L-Glutamic Acid (manufactured by Tokyo Chemical Industry Co., Ltd.) (C-2) L-glutamic acid (prepared by the method described in Production Example 1).

[0070] • Conjugated ketone compounds (D) 2-Cyclohexen-1-one (manufactured by Tokyo Chemical Industry Co., Ltd.) (E) Isophorone (manufactured by Tokyo Chemical Industry Co., Ltd.) (F)(E)-4-hexene-3-one (manufactured by Tokyo Chemical Industry Co., Ltd.).

[0071] • Additives (solvents) (G) 2-Propanol (manufactured by Tokyo Chemical Industry Co., Ltd.) (H) Dimethyl sulfoxide (manufactured by Tokyo Chemical Industry Co., Ltd.) (I) Pure water (manufactured by Tokyo Chemical Industry Co., Ltd.) (J)γ-butyrolactam.

[0072] Other raw materials (K) Ruthenium catalyst (L) 2,6-Dimethyl-4-heptanone (manufactured by Tokyo Chemical Industry Co., Ltd.) (M)γ-Butyrolactone (manufactured by Tokyo Chemical Industry Co., Ltd.) (N) Ammonia solution (ammonia content 28% by mass, manufactured by Tokyo Chemical Industry Co., Ltd.).

[0073] <Step (i) procedure> In a glass container with a lid, predetermined amounts of aminocarboxylic acid, conjugated ketone compound, additives, and other raw materials were added and stirred using a magnetic stirrer at the temperatures and times shown in Tables 1 to 6 to allow the reaction to proceed.

[0074] <Method for confirming the formation of reaction intermediates> A portion of the reaction solution obtained in step (i) is diluted 5 to 10 times with a diluent having the same components as the reaction solvent, and measured using an infrared spectrophotometer (IRSprit-X, manufactured by Shimadzu Corporation) at a wavenumber of 400 cm. -1 From 4000cm -1 Infrared spectroscopy measurements were performed within the range of 3300 cm⁻¹. -1 From 3500cm -1 The formation of the reaction intermediate was evaluated using the decrease in the surrounding peaks as an indicator. At this point, the preliminary reaction was terminated when the above peaks disappeared, and the process proceeded to step (ii).

[0075] <Procedure for process (ii)> The reaction solution obtained in step (i) was stirred using a magnetic stirrer at the temperatures and times shown in Tables 1 to 6 to allow the reaction to proceed.

[0076] <Method for calculating the yield of lactam compounds> A portion of the reaction solution was diluted 10-fold with heavy water, and the proton spectrum was measured using a nuclear magnetic resonance spectrometer. The yield of the lactam compound was defined as the integral value of the peak corresponding to the lactam compound, when the sum of the integral value of the peak corresponding to the lactam compound (chemical shift δ = 3.3 ppm if γ-butyrolactam is obtained as the product) and the integral value of the peak corresponding to the byproduct (chemical shift δ = 4.2 ppm for pyroglutamic acid, a byproduct of γ-butyrolactam) is taken as 100%.

[0077] <Method for measuring the specific heat of a solvent> Differential scanning calorimetry (DSC25, TA Instruments Inc.) was performed in accordance with JIS K 7123. The measurement involved first isothermal measurement at -20°C for 10 minutes, followed by heating from -20°C to 100°C at a rate of 10°C / min, and finally isothermal measurement at 100°C for 10 minutes. This measurement yielded a DSC curve with the vertical axis representing heat (mW) and the horizontal axis representing time (minutes). The subjects of measurement were an empty aluminum container (blank), an aluminum container containing aluminum oxide as a standard (standard), and aluminum containers containing each solvent (sample). The weights of the standard substances and solvents placed in the containers were prepared in the range of 10 mg to 20 mg.

[0078] Using the curve diagrams obtained from the measurements, the specific heat c of each solvent was calculated according to the following formula. c = (h ÷ H) × (m' ÷ m) × c p

[0079] Here, h is the difference in the vertical axis direction of the DSC curves of the blank and the sample at 25°C, H is the difference in the vertical axis direction of the DSC curves of the blank and the standard at 25°C, m' is the mass of the standard substance, m is the mass of each solvent, c p This is the specific heat of the standard substance at 25°C.

[0080] The specific heats of each solvent obtained from these measurements and calculations are as follows: • Dimethyl sulfoxide: 1.95 J / g·K • γ-Butyrolactam: 1.99 J / g·K 2-Propanol: 2.69 J / g·K • Dimethyl sulfoxide / 2-propanol = 50% by volume / 50% by volume mixed solution: 2.31 J / g·K ·Pure water: 4.18J / g·K

[0081] <Method for calculating energy costs when manufacturing lactam compounds> To compare the energy costs involved in producing lactam compounds, we use the energy efficiency E e The following was calculated: In the example, the E of step (ii), and in the comparative example, the E of step (ii) or other steps. e The following was evaluated. For the sake of simplifying the calculation, it was assumed that the reaction system was an adiabatic system and that the specific heat of the substrate (aminocarboxylic acid, conjugated ketone compound, catalyst, etc.) was equal to that of the solvent used. The specific heat of the solvent was determined using the value obtained by the <Method for measuring the specific heat of the solvent> described above, and E was calculated according to the following formula. e I calculated it. E e = c × M × ΔT ÷ t

[0082] Here, c represents the specific heat of the solvent (unit: J / g·K), M represents the total mass of the substrate and solvent (unit: g), ΔT represents the temperature change before and after heating (unit: K), and t represents the reaction time (unit: seconds). Furthermore, ΔT is the difference in reaction temperature between step (i) and step (ii) if step (i) is performed, and the temperature rise from 25°C if step (i) is not performed.

[0083] <Method for cleaning polyamide> The reaction mixture was filtered to obtain the polyamide, which was then added to an equal weight of hexane used as the solvent during polymerization and stirred at 30°C for 30 minutes. Afterward, the polyamide was filtered and added to an equal weight of water used as the hexane, and stirred for a further 30 minutes at 80°C.

[0084] <Method for determining the molecular weight of polyamide-4 polymers> The weight-average molecular weight of polyamide-4 polymers was calculated by comparing the results with a calibration curve using polymethyl methacrylate using gel permeation chromatography under the following conditions. The measurement sample was prepared by dissolving approximately 3.0 mg of polyamide-4 polymer in approximately 3.0 g of hexafluoroisopropanol. -conditions- • Equipment: Waterse-Alliance GPC system • Columns: HFIP-806M x 2 (manufactured by Showa Denko Corporation) Mobile phase: 5 mmol / L sodium trifluoroacetate / hexafluoroisopropanol ·Flow rate: 1.0ml / min Column temperature: 30°C • Detection method: Differential refractometer.

[0085] <Method for measuring the particle size of polyamide-4 polymer particles> The volume-average particle size of polyamide-4 polymer particles was measured under the following conditions. -conditions- • Equipment: Laser diffraction / scattering particle size analyzer (Microtrac MT3300EXII, manufactured by Nikkiso Co., Ltd.) ·Dispersion medium: water ·Flow rate: 50% • Number of washes: 3 • Ultrasonic output: 40W • Ultrasound duration: 180 seconds • Number of degassing cycles: 3.

[0086] <Sensory evaluation method for powdered cosmetics> A solid powder cosmetic was evenly applied to a 3cm square area of ​​a BioSkin Plate (P001-001#BSC, manufactured by Bealux Co., Ltd.) using a makeup puff (No. 8, manufactured by Daiso Industries Co., Ltd.).

[0087] Next, the measuring contact of the multi-functional static friction measuring instrument (TL201Tf, manufactured by Trinity Lab Co., Ltd.) (contact area 1 cm²) is placed on top of the applied powder cosmetic. 2 The bioskin plate was set up with a pressing load of 80g, and the kinetic friction force was measured when the bioskin plate was moved in one direction at a speed of 5mm / second. The kinetic friction coefficient calculated from the kinetic friction force and pressing load, and the length over which the cosmetic was spread by the contactor were recorded as characteristics of the powder cosmetic.

[0088] <Measurement of glass transition temperature of polyamide-4 polymer molded articles> Dynamic viscoelasticity measurements were performed using a dynamic viscoelasticity analyzer (ARES-G2, TA Instruments Inc.) at a heating rate of 5°C / min, a frequency of 1 Hz, and a temperature range of 30 to 200°C. The glass transition temperature was defined as the temperature at the intersection of the tangent line drawn to the glassy state and the tangent line drawn to the glass transition temperature region in the obtained graph of storage modulus and temperature.

[0089] (Example 1) A preliminary reaction was carried out using 1.00 g of (A) glutamine as the aminocarboxylic acid, 1.32 g of (D) 2-cyclohexen-1-one as the conjugated ketone compound, and 4.50 mL of (H) dimethyl sulfoxide as the solvent, under the conditions shown in Table 1, according to the procedure for <Step (i)> above. After the preliminary reaction, the reaction solution was analyzed according to the method for confirming the formation of reaction intermediates above, and it was confirmed that all the starting materials had been converted into reaction intermediates. Then, the lactam formation reaction was carried out at 130°C according to the procedure for <Step (ii)> above. The yield of the lactam compound was calculated from the reaction solution after the completion of Step (ii) according to the method for calculating the yield of the lactam compound above. It was found that γ-butyrolactam could be obtained in a good yield of 65% despite the lower reaction temperature and pressure compared to conventional techniques. Furthermore, the energy efficiency E e The results were also good.

[0090] (Manufacturing Example 1) L-glutamic acid derived from bio-based raw materials was produced by the method described in Example 1 of Japanese Patent Publication No. 3812019. The yield of L-glutamic acid was 53%.

[0091] (Examples 2-34) Lactam compounds were synthesized by following steps (i) and (ii) in the same manner as in Example 1, except that the raw materials and reaction conditions used were changed as shown in Tables 1 to 5. Despite the reaction temperatures in each example being lower than those of the conventional technique (80°C to 230°C), the yield of the obtained lactam compounds was good, ranging from 60% to 95%. Furthermore, the energy efficiency E e The results were also good.

[0092] (Manufacturing example 2) The ruthenium catalyst used in Comparative Example 1 was prepared according to the following method. First, 10 g of aluminum oxide (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was suspended in an aqueous solution containing 1 g of ruthenium(III) chloride (manufactured by Tokyo Chemical Industries, Ltd.) and stirred at room temperature for 1 hour. This suspension was heated to 70°C to evaporate the water, and then the temperature was raised to 110°C for a further 12 hours to remove the water. Subsequently, the resulting powder was reduced at 400°C under a hydrogen atmosphere for 3 hours to obtain the (J) ruthenium catalyst.

[0093] (Comparative Example 1) Based on the information in Non-Patent Document 1 (ChemSusChem, 2019, 12(7), 1381-1389), γ-butyrolactam was produced from glutamic acid using a (J) ruthenium catalyst. Specifically, the raw materials listed in Table 6 were placed in a 120 mL batch autoclave reactor (manufactured by Pressure Glass Industry Co., Ltd.), and the reaction was carried out by replacing the internal air with hydrogen gas. The reaction was carried out under mild conditions of a pressure of 2 MPa and a temperature of 160 °C, but the yield of the obtained γ-butyrolactam was 45%, which was lower than that of the examples.

[0094] (Comparative Example 2) γ-butyrolactam was produced using γ-butyrolactam and ammonia as raw materials, according to the method described in Example 1 of Patent Document 1 (JP 2005-505561). The yield of the obtained γ-butyrolactam was very good at 97%, but the reaction temperature was 285°C and the reaction pressure was 160 atmospheres, making it a production method with very high energy costs compared to the example.

[0095] (Comparative Example 3) As shown in Table 6, γ-butyrolactam was produced in the same manner as in the examples, except that step (i) was omitted. As a result of the reaction, the yield of γ-butyrolactam obtained was 47%, which was lower than in the examples. It is presumed that this was due to the production of a large amount of by-products as the reaction was carried out before sufficient reaction intermediates had been formed.

[0096] (Comparative Example 4) As shown in Table 6, γ-butyrolactam was prepared using the same method as in the examples, except that (K)2,6-dimethyl-4-heptanone, a ketone compound without a conjugated structure, was used instead of the conjugated ketone compound. As a result of the reaction, the yield of the obtained γ-butyrolactam was 10%, which was significantly lower than in the examples. This indicates that lactam compounds cannot be obtained in good yield with ketone compounds that do not have a conjugated structure.

[0097] (Comparative Example 5) As shown in Table 6, γ-butyrolactam was prepared using the same method as in the examples, except that a conjugated ketone compound was not used. As a result of the reaction, no γ-butyrolactam was produced at all.

[0098] (Manufacturing Example 3) In a flask equipped with a vacuum device, 85.1 g of γ-butyrolactam obtained by the method of Example 10, 200 g of liquid paraffin (MORESCO Corporation) as a solvent, and 1.7 g of t-potassium butoxide (Tokyo Chemical Industries, Ltd.) were added, and the mixture was stirred under reduced pressure at 40°C for 3 hours. At the end of stirring, the reaction solution was in an emulsion state in which fine droplets of γ-butyrolactam were suspended and dispersed in the liquid paraffin. After confirming that the γ-butyrolactam was uniformly suspended and dispersed in the solvent, 5.7 g of ε-caprolactone (Tokyo Chemical Industries, Ltd.) was added, and stirring was continued for a further 7 hours at 40°C under a nitrogen atmosphere.

[0099] The reaction solution was filtered, and the polyamide was washed according to the <Method for Washing Polyamide> described above. The obtained polyamide was dried under reduced pressure at 80°C to obtain 70.8 g of granular polyamide 4 polymer.

[0100] The weight-average molecular weight of this polyamide-4 polymer was calculated according to the <Method for Measuring the Molecular Weight of Polyamide-4 Polymer> described above, and was found to be 40,000. For comparison, the weight-average molecular weight of a polyamide-4 polymer polymer polymerized using a similar method with commercially available γ-butyrolactam (manufactured by Tokyo Chemical Industry Co., Ltd.) was 40,500, indicating a comparable result.

[0101] (Manufacturing example 4) In a SUS316 pressure vessel with a 100 mL reaction tank, 36 g of the polyamide 4 polymer obtained in Production Example 3 and 36 g of polyethylene glycol (weight-average molecular weight 20,000, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were added as a dispersion medium. After purging the system with nitrogen, the temperature was raised to 270°C under nitrogen flow conditions, and the mixture was melt-mixed for 30 minutes while stirring at 500 rpm using a stirring blade to form a polyamide 4 polymer / polyethylene glycol emulsion. After melt-mixing, the mixture was cooled to room temperature in the vessel while continuing the nitrogen flow.

[0102] 800 g of water was added to the resulting mixture, heated to 80°C, and stirred for 1 hour. The resulting slurry was filtered, and 800 g of water was added to the resulting solid, heated to 80°C, and stirred and washed for 1 hour. The slurry was then passed through a 200 μm sieve to remove aggregates, filtered again, and the isolated solid was dried at 80°C for 12 hours to obtain 25.4 g of polyamide 4 polymer particles.

[0103] The volume-average particle size of the obtained polyamide-4 polymer particles was calculated according to the <Method for Measuring the Particle Size of Polyamide-4 Polymer Particles> described above, and was found to be 9.6 μm. For reference, polyamide-4 polymer particles polymerized and atomized using a similar method with commercially available γ-butyrolactam (manufactured by Tokyo Chemical Industry Co., Ltd.) had a volume-average particle size of 9.3 μm, which is a comparable result.

[0104] (Manufacturing example 5) A solid powder cosmetic was prepared using polyamide-4 polymer particles obtained in Production Example 4 as the powder component. 5.0 g of the above polyamide-4 polymer particles, 2.0 g of jojoba oil (NIKKOL Jojoba Oil S, manufactured by Nikko Chemicals Co., Ltd.) as the first oil component, 3.0 g of dimethicone (manufactured by Shin-etsu Kogyo Co., Ltd.) as the second oil component, 5.0 g of carbon black (manufactured by Tokyo Chemical Industry Co., Ltd.) as the pigment, 85.0 g of titanium dioxide (manufactured by Tokyo Chemical Industry Co., Ltd.) as the filler, and 50 mL of pure water (manufactured by Tokyo Chemical Industry Co., Ltd.) as the dispersion medium were placed in a 300 mL stainless steel cup and mixed with a mechanical stirrer until uniform. The resulting paste was placed in a mold of a predetermined shape and size, molded using a suction compression molding machine with a porous head, and then dried in a 60°C oven for 24 hours to obtain a gray to black solid powder cosmetic.

[0105] The properties of the obtained powdered cosmetic were evaluated according to the <Sensory Evaluation Method for Powdered Cosmetics> described above. The coefficient of dynamic friction of the powdered cosmetic prepared in this manufacturing example was 5.5 × 10⁻⁶. -3 The length over which the cosmetic was spread was 3.3 cm. Furthermore, the properties of a solid powder cosmetic prepared by the same method using polyamide 4 polymer particles made from commercially available γ-butyrolactam (manufactured by Tokyo Chemical Industry Co., Ltd.) were as follows: the coefficient of dynamic friction was 5.4 × 10⁻⁶. -3 The length over which the cosmetic was applied was 3.5 cm, and the results were comparable.

[0106] (Manufacturing example 6) The polyamide 4 polymer obtained by the method of Production Example 3 was dried under reduced pressure at 80°C for 12 hours. Then, using an injection molding machine (SE75DUZ-C250, manufactured by Sumitomo Heavy Industries, Ltd.), a plate-shaped test specimen with a thickness of 2 mm, a length of 45 mm, and a width of 12.7 mm was produced by injection molding under the conditions of cylinder temperature: 250°C and mold temperature: 80°C.

[0107] The glass transition temperature of the obtained test specimens was measured according to the above-mentioned <Measurement of Glass Transition Temperature of Polyamide 4 Polymer Molded Articles> and was found to be 90°C. For comparison, the glass transition temperature of polyamide 4 polymer molded articles using commercially available γ-butyrolactam (manufactured by Tokyo Chemical Industry Co., Ltd.) as a raw material was 89°C, which is a comparable result.

[0108] [Table 1-1]

[0109] [Table 1-2]

[0110] [Table 2-1]

[0111] [Table 2-2]

[0112] [Table 3-1]

[0113] [Table 3-2]

[0114] [Table 4-1]

[0115] [Table 4-2]

[0116] [Table 5-1]

[0117] [Table 5-2]

[0118] [Table 6-1]

[0119] [Table 6-2] [Industrial applicability]

[0120] According to the present invention, it is possible to obtain lactam compounds in high yield while reducing the energy costs involved in their production. The lactam compounds of the present invention can be suitably used as raw materials for pharmaceuticals, solvents, polymers, and the like.

Claims

1. A method for producing a lactam compound, comprising steps (i) and (ii) in that order. Step (i): A step in which an aminocarboxylic acid and a conjugated ketone compound are mixed and a preliminary reaction is carried out to form an imine compound. Step (ii): A step in which the imine compound obtained in step (i) is reacted at a reaction temperature higher than the reaction temperature in step (i) to form a lactam compound represented by formula (I). 【Chemistry 1】 (In formula (I), R, R', R'', R ｎ１ , R ｎ２ Each of these is a functional group consisting of hydrogen, an alkyl group with 1 to 6 carbon atoms, a phenyl group, a cycloalkyl group with 3 to 9 carbon atoms, or a combination thereof. n is a natural number between 1 and 11.

2. A method for producing a lactam compound according to claim 1, wherein the aminocarboxylic acid is a compound represented by formula (II). 【Chemistry 2】 (In formula (II), R ｍ１ , R ｍ２ , R ｍ３ Each of these is a functional group consisting of hydrogen, an alkyl group with 1 to 6 carbon atoms, a phenyl group, a cycloalkyl group with 3 to 9 carbon atoms, or a combination thereof. m is a natural number between 1 and 11. X and Y are atoms selected from hydrogen, sodium, potassium, and calcium, respectively.

3. A method for producing a lactam compound according to claim 1 or 2, wherein the ratio of the number of moles of the conjugated ketone compound to the number of moles of the aminocarboxylic acid (number of moles of conjugated ketone compound / number of moles of aminocarboxylic acid) is 0.1 or more and 10 or less.

4. A method for producing a lactam compound according to any one of claims 1 to 3, wherein the reaction temperature in step (i) is 10°C or more and 200°C or less, and the reaction temperature in step (ii) is 70°C or more and 270°C or less.

5. A lactam compound obtained by a method for producing a lactam compound according to any one of claims 1 to 4.

6. A polyamide obtained by polymerizing a raw material containing the lactam compound described in claim 5.

7. A polyamide product obtained by processing the polyamide described in claim 6.

8. A polyamide-containing product comprising the polyamide described in claim 6, or the polyamide processed product described in claim 7.

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