JP2011201864A - Pentamethylene diamine or salt thereof and method for preparing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for preparing pentamethylene diamine or a salt thereof having reduced amount of impurities in a high yield, and the pentamethylene diamine or a salt thereof obtained by the preparation method.SOLUTION: The method comprises extracting pentamethylene diamine or a salt thereof from an aqueous solution containing the pentamethylene diamine or a salt thereof using a 4-7C monohydric alcohol.

Description

  The present invention relates to pentamethylenediamine or a salt thereof, and a production method thereof.

  Conventionally, 1,5-pentamethylenediamine (also known as cadaverine) and its salts include, for example, intermediates for pharmaceuticals and agricultural chemicals, raw materials for polyisocyanates that are polyurethane raw materials, such as polyamide raw materials, polyimide raw materials, and epoxy It is useful as a resin raw material such as a raw material.

  As a method for producing such 1,5-pentamethylenediamine (cadaverine) or a salt thereof, for example, L-crude purified lysine decarboxylase is allowed to act on an aqueous solution of lysine hydrochloride, and 1,5-diaminopentane hydrochloride is used. After obtaining a salt, a method has been proposed in which 1,5-diaminopentane hydrochloride is converted to 1,5-diaminopentane, and then 1,5-diaminopentane is extracted from the reaction solution using chloroform. (For example, refer to Patent Document 1).

JP 2003-292612 A (Reference Examples 2 and 3)

  However, in the method described in Patent Document 1, 1,5-diaminopentane may not be obtained efficiently.

  In the method described in Patent Document 1, impurities are contained in the obtained 1,5-diaminopentane. When such 1,5-diaminopentane is used as a resin raw material, there is a problem that the properties of the resulting resin are lowered.

  An object of the present invention is to provide a method for producing pentamethylenediamine or a salt thereof capable of producing pentamethylenediamine or a salt thereof with a reduced impurity content in a high yield, and a pentamethylene obtained by the production method. The object is to provide a diamine or a salt thereof.

  In order to achieve the above object, the method for producing pentamethylenediamine or a salt thereof according to the present invention comprises converting pentamethylenediamine or a salt thereof from an aqueous solution containing pentamethylenediamine or a salt thereof into a monovalent carboxylic acid having 4 to 7 carbon atoms. It is characterized by extraction with alcohol.

  In the method for producing pentamethylenediamine or a salt thereof of the present invention, it is preferable to extract pentamethylenediamine or a salt thereof without subjecting the aqueous solution containing pentamethylenediamine or a salt thereof to heat treatment at 90 ° C. or higher. is there.

  In the method for producing pentamethylenediamine or a salt thereof of the present invention, the monohydric alcohol is preferably a linear monohydric alcohol.

  In the method for producing pentamethylenediamine or a salt thereof of the present invention, it is preferable to obtain an aqueous solution containing pentamethylenediamine or a salt thereof by decarboxylase reaction of lysine or a salt thereof.

  In addition, the pentamethylenediamine or a salt thereof of the present invention is obtained by the above-described method for producing pentamethylenediamine or a salt thereof.

  Further, the pentamethylenediamine or a salt thereof of the present invention has a content of a nitrogen-containing six-membered ring compound having an amino group and a C═N bond with respect to the total amount of pentamethylenediamine or a salt thereof is 1.5% by mass or less. It is preferable that

  In the pentamethylenediamine or salt thereof of the present invention, the nitrogen-containing six-membered ring compound having an amino group and a C═N bond is 2- (aminomethyl) -3,4,5,6-tetrahydropyridine. Is preferred.

  In the method for producing pentamethylenediamine or a salt thereof according to the present invention, pentamethylenediamine or a salt thereof is extracted with a monohydric alcohol having 4 to 7 carbon atoms. Therefore, pentamethylenediamine or a salt thereof can be efficiently extracted. Furthermore, the content ratio of impurities of pentamethylenediamine or a salt thereof can be reduced.

  Therefore, according to the pentamethylenediamine or a salt thereof of the present invention, a resin having excellent properties can be produced efficiently.

The chromatogram of GC-MS analysis 1 in the structural analysis of an unknown substance is shown. The spectrum of GC-MS analysis 1 in the structural analysis of an unknown substance is shown. The chromatogram of GC-MS analysis 2 in the structural analysis of an unknown substance is shown. The result of ¹ H-NMR in the structural analysis of the unknown substance is shown. The result of ¹³ C-NMR in the structural analysis of the unknown substance is shown. The result of COSY in the structural analysis of an unknown substance is shown. The result of HMQC in the structural analysis of an unknown substance is shown. The result of HMBC in the structural analysis of an unknown substance is shown. The result (enlarged view) of HMBC in the structural analysis of an unknown substance is shown.

  In the method for producing pentamethylenediamine or a salt thereof of the present invention, pentamethylenediamine or a salt thereof is extracted from an aqueous solution containing pentamethylenediamine or a salt thereof (hereinafter referred to as a pentamethylenediamine aqueous solution).

  In the present invention, examples of pentamethylenediamine include 1,5-pentamethylenediamine (also known as cadaverine, 1,5-diaminopentane), 1,4-pentamethylenediamine, 1,3-pentamethylenediamine, 2, 5-diaminopentane or a mixture thereof may be mentioned.

  These pentamethylenediamines can be used alone or in combination of two or more.

  As the pentamethylenediamine, 1,5-pentamethylenediamine is preferable.

  Examples of the salt of pentamethylenediamine include, for example, carboxylate (eg, acetate, oxalate, 2-ethylhexanoate, stearate), sulfonate, etc. Organic acid salts, for example, inorganic acid salts such as nitrates, sulfates, hydrochlorides, phosphates, carbonates, bicarbonates, and the like.

  As the salt of pentamethylenediamine, preferably, the hydrochloride of pentamethylenediamine is used.

  Such pentamethylenediamine or a salt thereof is extracted from, for example, an aqueous solution containing pentamethylenediamine or a salt thereof (hereinafter referred to as a pentamethylenediamine aqueous solution).

  As such pentamethylenediamine or a salt thereof, preferably, pentamethylenediamine is used.

  The pentamethylenediamine aqueous solution is not particularly limited, and can be obtained, for example, by decarboxylase reaction of lysine in water.

  Hereinafter, the decarboxylase reaction of lysine will be described in detail.

In lysine decarboxylase reaction, lysine decarboxylase is allowed to act on lysine (chemical formula: NH ₂ (CH ₂ ) ₄ CH (NH ₂ ) COOH, also known as: 1,5-pentamethylenediamine-1-carboxylic acid). .

  Examples of lysine include L-lysine.

  As lysine, a salt of lysine can also be used.

  Examples of lysine salts include carboxylate (for example, acetate, oxalate, 2-ethylhexanoate, stearate, etc.), organic acid salt such as sulfonate, for example, nitrate, sulfate, Examples thereof include inorganic acid salts such as hydrochloride, phosphate, carbonate, and bicarbonate.

  As a salt of lysine, lysine hydrochloride is preferable.

  Examples of such lysine hydrochloride include L-lysine monohydrochloride.

  The concentration of lysine (or a salt thereof) is not particularly limited, but is, for example, 10 to 700 g / L, preferably 20 to 500 g / L.

  The lysine decarboxylase is an enzyme that converts lysine (or a salt thereof) to pentamethylenediamine (or a salt thereof), and is not particularly limited, and examples thereof include those derived from known organisms. More specific examples of lysine decarboxylase include, for example, Bacillus halodurans, Bacillus subtilis, Escherichia coli, Selenomonas luminobis, and Selenomonas luminobia. (Vibrio cholerae), Vibrio parahaemolyticus, Streptomyces coelicolor, Streptomyces pirosus (St), and Streptomyces pirosus (St). Cuterium acididaminofilm, Salmonella typhimurium, Hafnia albei, Neisseria meningitide Examples include those derived from microorganisms such as Pyrococcus abyssi) or Corynebacterium glutamicum. From the viewpoint of safety, preferably, those derived from Escherichia coli are used.

  Lysine decarboxylase can be produced by a known method, for example, according to the description in JP-A No. 2004-114 (for example, paragraph numbers [0015] to [0042], etc.).

  More specifically, as a method for producing lysine decarboxylase, for example, recombinant cells in which lysine decarboxylase is highly expressed in cells (hereinafter referred to as internal expression cells) are cultured in a known medium, and then proliferated. A method of recovering and disrupting the internally expressed cells, for example, a recombinant cell in which lysine decarboxylase is localized on the cell surface (hereinafter referred to as a surface-expressing cell) is cultured in a known medium, and then proliferated surface expression Examples include a method of recovering cells and crushing them if necessary.

  In such a method, the recombinant cell is not particularly limited, and examples include those derived from microorganisms, animals, plants, or insects. More specifically, for example, when animals are used, examples include mice, rats and cultured cells thereof, and when plants are used, examples include Arabidopsis, tobacco and cultured cells thereof. In addition, in the case of using insects, for example, silkworms and cultured cells thereof can be mentioned, and in the case of using microorganisms, for example, Escherichia coli and the like can be mentioned.

  These recombinant cells can be used alone or in combination of two or more.

  The method for localizing lysine decarboxylase on the surface of a recombinant cell is not particularly limited. For example, a part of a secretory signal sequence, a gene sequence encoding a part of a cell surface localized protein, and lysine A known method such as a method of introducing DNA having a decarboxylase structural gene sequence in this order into E. coli can be employed.

  The secretory signal sequence is not particularly limited as long as it is a sequence necessary for secreting the protein in the host. For example, in Escherichia coli, for example, a part of the lipoprotein sequence, more specifically, Examples of the amino acid sequence include a gene sequence translated as MKATKLVLGAVILGSTLLAGCSSSNAKIDQ (single letter code of amino acid).

  The gene sequence encoding a part of the cell surface localized protein is not particularly limited. In E. coli, for example, a part of the sequence of the outer membrane-bound protein can be mentioned, and more specifically, for example, OmpA ( And a part of the sequence from the 46th amino acid to the 159th amino acid of the outer membrane binding protein).

  The method for cloning the lysine decarboxylase gene, lipoprotein gene, and OmpA gene is not particularly limited. For example, based on known gene information, a necessary genetic region is amplified and obtained using the PCR (polymerase chain reaction) method. For example, based on known gene information, a method of cloning from a genomic library or cDNA library using homology or enzyme activity as an index may be mentioned.

  These genes also include mutated genes due to genetic polymorphism (those in which the base sequence of the gene is partially changed due to natural mutation on the gene).

  More specifically, for example, the cadA gene or the ldc gene, which is a gene encoding lysine decarboxylase, is cloned from the chromosomal DNA of Escherichia coli K12 using the PCR method. In addition, the chromosome DNA employ | adopted at this time will not be restrict | limited if it is Escherichia coli origin, The thing derived from arbitrary strains can be employ | adopted.

  In addition, lysine decarboxylase is localized on the surface of the surface-expressing cells obtained in this way, for example, after surface-expressing cells are immunoreacted with an antibody prepared using lysine decarboxylase as an antigen. It can be confirmed by embedding and slicing, for example, by observing with an electron microscope (immunoelectron microscopy).

  In the surface-expressing cells, lysine decarboxylase may be localized on the cell surface. For example, lysine decarboxylase may be localized on the cell surface and expressed inside the cell.

  Examples of the lysine decarboxylase include those prepared from recombinant cells in which the activity of lysine decarboxylase in the cells and / or on the cell surface is increased.

  The method for increasing the activity of lysine decarboxylase in the cell and / or on the cell surface is not particularly limited, and for example, a method for increasing the amount of lysine decarboxylase, for example, intracellular of lysine decarboxylase and And / or a method for increasing the activity on the cell surface.

  Examples of means for increasing the amount of enzyme in the cell or on the cell surface include improvement of the transcriptional regulatory region of the gene, increase in the copy number of the gene, and efficient translation into the protein.

  Improving the transcriptional regulatory region means adding a modification that increases the transcription amount of the gene. For example, the promoter is strengthened by introducing a mutation into the promoter, and the transcription amount of the downstream gene is increased. it can. In addition to introducing a mutation into the promoter, a promoter that is strongly expressed in the host can also be introduced. More specifically, examples of the promoter include lac, tac, trp and the like in E. coli. In addition, the amount of gene transcription can be increased by newly introducing an enhancer. The introduction of a gene such as a chromosomal DNA promoter can be based on, for example, the description of JP-A-1-215280.

  Specifically, the increase in the copy number of a gene can be achieved by connecting the gene to a multi-copy vector to produce a recombinant DNA and allowing the host cell to hold the recombinant DNA. Vectors include those widely used, such as plasmids and phages, but besides these, for example, transposon (Berg, DE and Berg. CM, Bio / Technol., Vol. 1, P.417 (1983)) and Mu phage (Japanese Patent Laid-Open No. 2-109985). Furthermore, the number of copies can be increased by incorporating the gene into the chromosome by a method using a plasmid for homologous recombination.

  As a method for increasing the translation efficiency of a protein, for example, in prokaryotes, an SD sequence (Shine, J. and Dalgarno, L., Proc. Natl. Acad. Sci. USA, 71, 1342-1346 (1974)) In eukaryotes, Kozak consensus sequences (Kozak, M., Nuc. Acids Res., Vol. 15, p. 8125-8148 (1987)) are introduced and modified, and codon optimization (special No. 59-125895).

  As a method for increasing the intracellular and / or cell surface activity of lysine decarboxylase, a mutation may be introduced into the structural gene itself of lysine decarboxylase to increase the activity of lysine decarboxylase itself. It is done.

  Examples of methods for causing mutations in genes include site-specific mutagenesis (Kramer, W. and frita, HJ, Methods in Enzymology, vol. 154, P. 350 (1987)), recombinant PCR method ( PCR Technology, Stockton Press (1989), a method of chemically synthesizing a specific portion of DNA, a method of treating a gene with a hydroxylamine, a strain carrying the gene with ultraviolet irradiation, or a chemical agent such as nitrosoguanidine or nitrous acid The method of processing is mentioned.

  In addition, the method for culturing such recombinant cells (internally expressed cells, surface-expressing cells, etc.) is not particularly limited, and known methods can be employed. More specifically, for example, when culturing a microorganism, a medium containing, for example, a carbon source, a nitrogen source, and inorganic ions is used as the medium.

  Examples of the carbon source include sugars such as glucose, lactose, galactose, fructose, arabinose, maltose, xylose, trehalose, ribose and starch hydrolysate, for example, alcohols such as glycerol, mannitol and sorbitol, for example, gluconic acid , Organic acids such as fumaric acid, citric acid and succinic acid.

  These carbon sources can be used alone or in combination of two or more.

  Examples of the nitrogen source include inorganic ammonium salts such as ammonium sulfate, ammonium chloride, and ammonium phosphate, and organic nitrogen such as soybean hydrolysate, such as ammonia gas and aqueous ammonia.

  These nitrogen sources can be used alone or in combination of two or more.

  Examples of the inorganic ions include sodium ions, magnesium ions, potassium ions, calcium ions, chlorine ions, manganese ions, iron ions, phosphate ions, and sulfate ions.

  These inorganic ions can be used alone or in combination of two or more.

Moreover, the medium, if necessary, can also be added other organic components (organic trace nutrients), Examples of such organic components, for example, various amino acids, for example, vitamins such as vitamin B _1, For example, required substances such as nucleic acids such as RNA, and further, for example, yeast extract.

  More specifically, such a medium includes LB medium.

  The culture conditions are not particularly limited. For example, when culturing E. coli, the culture temperature is, for example, 30 to 45 ° C., preferably 30 to 40 ° C., and the culture pH is aerobic. For example, it is 5 to 8, preferably 6.5 to 7.5, and the culture time is, for example, 16 to 72 hours, preferably 24 to 48 hours. For adjusting the pH, for example, an inorganic or organic acidic or alkaline substance, ammonia gas, or the like can be used.

  Recombinant cells (internally expressed cells, surface-expressing cells) grown in such a medium can be collected by, for example, centrifugation.

  In this method, the collected cells can be used as, for example, resting cells. However, if necessary, they can be crushed and used as a cell lysate (bacterial cell lysate).

  In preparing the cell disruption solution (bacterial cell disruption solution), a known method can be employed. More specifically, for example, the obtained internal expression cells and / or surface expression cells are first crushed by a method such as sonication, dynomill, French press, etc., and then cell debris is removed by centrifugation. To do.

  In this method, lysine decarboxylase can be purified from the obtained cell lysate, if necessary.

  The purification method of lysine decarboxylase is not particularly limited, and is a known method usually used for enzyme purification (for example, ammonium sulfate fractionation, ion exchange chromatography, hydrophobic chromatography, affinity chromatography, gel filtration chromatography, Isoelectric point precipitation, heat treatment, pH treatment, etc.) can be employed in combination as appropriate.

  In the decarboxylase reaction of lysine (or a salt thereof), the resting cells and / or cell lysate thus obtained are mixed with an aqueous solution of lysine (or a salt thereof), and the lysine desorbed in water. Carbonate acts on lysine (or its salt).

  The ratio of the dry cell equivalent mass of the cells (cells) used for the reaction to the total mass of lysine (or its salt) used for the reaction is that lysine (or its salt) is converted to pentamethylenediamine (or its salt). The amount is not particularly limited as long as it is sufficient for conversion, but is, for example, 0.01 or less, preferably 0.007 or less.

  The total mass of lysine (or salt thereof) used in the reaction is the mass of lysine (or salt thereof) present in the reaction system at the start of the reaction (lysine (or salt thereof) is added to the reaction system during the reaction) In some cases, the total amount of those lysines (or their salts).

  Moreover, the dry cell equivalent mass of a microbial cell is the mass of the microbial cell which dries and does not contain a water | moisture content. The dry cell equivalent mass of the bacterial cell is, for example, separated from the liquid containing the bacterial cell (bacterial cell liquid) by a method such as centrifugation or filtration, dried until the mass becomes constant, and the mass is measured. Can be obtained.

  The reaction temperature in the decarboxylase reaction of lysine (or a salt thereof) is, for example, 28 to 55 ° C., preferably 35 to 45 ° C., and the reaction time varies depending on the type of lysine decarboxylase employed. For example, it is 1 to 72 hours, preferably 12 to 36 hours. Moreover, reaction pH is 5.0-8.0, for example, Preferably, it is 5.5-6.5.

  Thereby, lysine (or a salt thereof) undergoes a decarboxylase reaction to be converted into pentamethylenediamine, and as a result, an aqueous solution of pentamethylenediamine is obtained.

  The reaction yield of pentamethylenediamine or a salt thereof is, for example, 10 to 100 mol%, preferably 70 to 100 mol%, more preferably 80 to 100 mol%, based on lysine (or a salt thereof). .

  Further, the concentration of pentamethylenediamine or a salt thereof in the aqueous solution of pentamethylenediamine (in the case of pentamethylenediamine salt, the concentration in terms of pentamethylenediamine) is, for example, 1 to 70% by mass, preferably 2 to 50% by mass, and more preferably. Is 5-40 mass%.

  In this reaction, since the obtained pentamethylenediamine is alkaline, the pH of the reaction solution may increase as lysine (or a salt thereof) is converted to pentamethylenediamine (or a salt thereof). In such a case, if necessary, an acidic substance (for example, an organic acid, for example, an inorganic acid such as hydrochloric acid) can be added to adjust the pH.

In this reaction, for example, vitamin B ₆ and / or a derivative thereof can be added to the reaction solution as necessary.

Examples of vitamin B ₆ and / or derivatives thereof include pyridoxine, pyridoxamine, pyridoxal, pyridoxal phosphate, and the like.

These vitamin B ₆ and / or derivatives thereof can be used alone or in combination of two or more.

Vitamin B ₆ and / or its derivatives are preferably pyridoxal phosphate.

By adding vitamin of B ₆ and / or its derivatives, it is possible to improve the production rate and yield of pentamethylene diamine.

  In this method, a part of the water is distilled off from the obtained aqueous solution of pentamethylenediamine if necessary.

  More specifically, for example, an aqueous pentamethylenediamine solution is heated (heat treated) under a pressure of 0.1 kPa to normal pressure by a distillation apparatus equipped with a continuous multistage distillation column, a batch multistage distillation column, etc. A pentamethylenediamine aqueous solution in which a part of is distilled off is obtained.

  The heating temperature is, for example, 25 ° C. or more and less than 90 ° C., preferably 25 ° C. or more and 85 ° C. or less, more preferably 25 ° C. or more and less than 80 ° C., more preferably 30 ° C. or more and 70 ° C. or less. is there.

  When the aqueous solution of pentamethylenediamine is heated at 90 ° C. or higher (heat treatment), the content of a nitrogen-containing six-membered ring compound having a C═N bond (described later) relative to the total amount of pentamethylenediamine or a salt thereof increases. The extraction rate of pentamethylenediamine or a salt thereof may decrease.

  Therefore, preferably, the aqueous solution of pentamethylenediamine is not heated (heat treatment) at 90 ° C. or higher, more preferably, it is not heated at 80 ° C. or higher, and more preferably, the aqueous solution of pentamethylene diamine is heated (heat treatment). Instead, as described later, pentamethylenediamine or a salt thereof is extracted as it is from the aqueous solution.

  In the pentamethylenediamine aqueous solution, the concentration of pentamethylenediamine is, for example, 5 to 80% by mass, preferably 15 to 60% by mass with respect to the total amount of the pentamethylenediamine aqueous solution.

  In this method, pentamethylenediamine or a salt thereof is extracted. In the extraction, for example, a liquid-liquid extraction method is employed.

  In the liquid-liquid extraction method, for example, (1) pentamethylenediamine or a salt thereof is obtained by bringing an extraction solvent (described later) into contact with a pentamethylenediamine aqueous solution batchwise, semi-continuously or continuously, and mixing and stirring. Is extracted (distributed) into an extraction solvent (described later), and pentamethylenediamine or a salt thereof is separated from the extraction solvent (described later). (2) A tower (spray tower, step extraction tower) provided with a perforated plate And a column equipped with a packing, nozzle, orifice plate, baffle, injector and / or static mixer (countercurrent differential extraction column, non-stirring type column extraction column: revised fifth edition Chemical Engineering Handbook, p566 to 569, chemistry To the Engineering Society, Maruzen (1988), a pentamethylenediamine aqueous solution and an extraction solvent (described later) are continuously supplied in a countercurrent flow. Extract the salt into an extraction solvent (described later), and then continuously flow out the extraction solvent (described later) to separate pentamethylenediamine or a salt thereof from the extraction solvent (described later), (3) A tower equipped with a baffle plate and a stirring blade (stirring type extraction tower: Revised 5th edition, Chemical Engineering Handbook, p. Are supplied continuously in countercurrent, and pentamethylenediamine or a salt thereof is extracted (distributed) into an extraction solvent (described later), and then the extraction solvent (described later) is continuously flowed out and extracted. Method for separating pentamethylenediamine or a salt thereof from a solvent (described later), (4) mixer settler extractor or centrifugal extractor (revised fifth edition chemical engineering manuals p563 to 566, p574) Chemical Engineering Society, Maruzen (1988)), an extraction solvent (described later) is brought into contact with an aqueous pentamethylenediamine solution, and pentamethylenediamine or a salt thereof is extracted (distributed) into the extraction solvent (described later). A method of separating pentamethylenediamine or a salt thereof from an extraction solvent (described later) is employed.

  These liquid-liquid extraction methods can be used alone or in combination of two or more.

  From the viewpoint of production efficiency, the liquid-liquid extraction method is preferably a method of continuously extracting (distributing) pentamethylenediamine or a salt thereof into an extraction solvent (described later), more specifically, for example, The method of (1)-(3) is mentioned.

  The blending ratio of the pentamethylenediamine aqueous solution and the extraction solvent (described later) in the liquid-liquid extraction is 100 parts by mass of the pentamethylenediamine aqueous solution (if the extraction is continuous, the supply amount per unit time. The same applies hereinafter). On the other hand, an extraction solvent (after-mentioned) is 30-300 mass parts, for example, From a viewpoint of economical efficiency and productivity, Preferably, it is 50-200 mass parts, More preferably, it is 50-150 mass, Especially preferably, It is 80-120 mass parts.

  In liquid-liquid extraction, an aqueous pentamethylenediamine solution and an extraction solvent (described later) are, for example, under normal pressure (atmospheric pressure), for example, 5 to 60 ° C., preferably 10 to 60 ° C., more preferably, The mixture is mixed at 15 to 50 ° C., more preferably 15 to 40 ° C., for example, with a stirring blade, for example, for 1 to 120 minutes, preferably 5 to 90 minutes, preferably 5 to 60 minutes.

  The stirring blade is not particularly limited. For example, a propeller, a flat blade, an angled flat blade, a pitched flat blade, a flat blade disk turbine, a tilted blade disk turbine, a curved blade, a Fiddler type, a blue margin type, a dissolver, An anchor etc. are mentioned.

  Moreover, as rotation speed in mixing, it is 5-3000 rpm, for example, Preferably, it is 10-2000 rpm, More preferably, it is 20-1000 rpm.

  Thereby, pentamethylenediamine or a salt thereof is extracted into an extraction solvent (described later).

  Next, in this method, a mixture of pentamethylenediamine or a salt thereof and an extraction solvent (described later) is allowed to stand, for example, for 5 to 300 minutes, preferably 10 to 240 minutes, more preferably 20 to 180 minutes, Thereafter, the extraction solvent from which pentamethylenediamine or a salt thereof is extracted (that is, a mixture of the extraction solvent (described later) and pentamethylenediamine or a salt thereof) is taken out by a known method.

  When pentamethylenediamine or a salt thereof cannot be sufficiently extracted by one liquid-liquid extraction, liquid-liquid extraction can be repeated a plurality of times (for example, 2 to 5 times).

  Thereby, pentamethylenediamine or a salt thereof in the pentamethylenediamine aqueous solution can be extracted into an extraction solvent (described later).

  In the extraction solvent thus obtained (a mixture of the extraction solvent (described later) and pentamethylenediamine or a salt thereof), the concentration of pentamethylenediamine or a salt thereof is, for example, 0.2 to 40% by mass, preferably It is 0.3-35 mass%, More preferably, it is 0.4-30 mass%, Most preferably, it is 0.8-25 mass%.

  Moreover, the yield (extraction rate) of pentamethylenediamine or a salt thereof after extraction is, for example, 65 to 100 mol%, preferably 70 to 100 mol%, more preferably based on lysine (or a salt thereof). 80 to 100 mol%, particularly preferably 90 to 100 mol%.

  In this method, for example, pentamethylenediamine or a salt thereof can be isolated from a mixture of the obtained extraction solvent (described later) and pentamethylenediamine or a salt thereof, if necessary. The isolation of pentamethylenediamine or a salt thereof is not particularly limited, but for example, by a distillation apparatus equipped with a continuous multistage distillation column, a batch multistage distillation column, or the like, for example, 50 to 182 ° C., 0.1 kPa to normal pressure, A mixture of the extraction solvent (described later) and pentamethylenediamine or a salt thereof is distilled to remove the extraction solvent (described later).

  In such extraction, examples of the extraction solvent include monohydric alcohols having 4 to 7 carbon atoms.

  Examples of the monohydric alcohol having 4 to 7 carbon atoms include linear monohydric alcohol having 4 to 7 carbon atoms and branched monohydric alcohol having 4 to 7 carbon atoms.

  Examples of the linear monovalent alcohol having 4 to 7 carbon atoms include n-butanol, n-pentanol, n-hexanol, and n-heptanol.

  Examples of the branched monohydric alcohol having 4 to 7 carbon atoms include 2-butanol, isobutanol, tert-butanol, 2-pentanol, 3-pentanol, isopentanol, 2-methyl-1-butanol, 2-methyl-3-butanol, 2,2-dimethyl-1-propanol, tert-pentanol, 2-hexanol, 3-hexanol, isohexanol, 2-methyl-2-pentanol, 2-methyl-1-pen Tanol, 3-methyl-1-pentanol, 2-ethyl-1-butanol, 3,3-dimethyl-1-butanol, 2-heptanol, 3-heptanol, 4-heptanol, 5-methyl-1-hexanol, 4 -Methyl-1-hexanol, 3-methyl-1-hexanol, 2-ethyl-2-methyl-1-butanol And so on.

  These monohydric alcohols having 4 to 7 carbon atoms can be used alone or in combination of two or more.

  The monovalent alcohol having 4 to 7 carbon atoms is preferably a linear monohydric alcohol having 4 to 7 carbon atoms.

  When a linear monohydric alcohol having 4 to 7 carbon atoms is used, pentamethylenediamine or a salt thereof can be extracted with a high yield. In the removal of the extraction solvent, pentamethylenediamine can be extracted. The property can be maintained.

  Moreover, as linear C1-C7 monohydric alcohol, More preferably, n-butanol, n-pentanol, n-hexanol, More preferably, n-butanol and n-pentanol are mentioned.

  Moreover, in this invention, the boiling point of an extraction solvent is 60-250 degreeC, for example, Preferably, it is 80-200 degreeC, More preferably, it is 90-150 degreeC.

  When the boiling point of the extraction solvent is less than the above lower limit, separation from the extraction solvent may be difficult when pentamethylenediamine or a salt thereof is obtained by extraction from an aqueous pentamethylenediamine solution.

  On the other hand, when the boiling point of the extraction solvent exceeds the above upper limit, when obtaining pentamethylenediamine or a salt thereof from a mixture of the extraction solvent and pentamethylenediamine or a salt thereof, energy consumption in the separation step may increase. .

  The pentamethylenediamine or salt thereof thus obtained does not contain a nitrogen-containing six-membered ring compound having a C═N bond (hereinafter sometimes referred to as C═N six-membered ring compound), Or the content is reduced.

  Examples of the C═N six-membered ring compound include a nitrogen-containing six-membered ring compound having an amino group and a C═N bond (hereinafter, sometimes referred to as an amino group-containing C═N six-membered ring compound), C. And a nitrogen-containing six-membered ring compound having an N bond and no amino group (hereinafter referred to as an amino group-free C = N six-membered ring compound).

  Examples of the amino group-containing C═N six-membered ring compound include compounds represented by the following formula (1).

(In the formula, X represents an aminomethyl group.)
More specifically, examples of the compound represented by the formula (1) include 2- (aminomethyl) -3,4,5,6-tetrahydropyridine.

  Examples of the amino group-free C═N six-membered ring compound include 2,3,4,5-tetrahydropyridine.

  In the present invention, the total amount of pentamethylenediamine or a salt thereof (pentamethylenediamine or a salt thereof and impurities (including an amino group-containing C = N six-membered ring compound and an amino group-free C = N six-membered ring compound) The content of these C = N six-membered ring compounds with respect to the total amount) (the total amount of amino group-containing C = N six-membered ring compounds and amino group-free C = N six-membered ring compounds) is 2% by mass or less, Preferably, it is 1.8 mass% or less, More preferably, it is 1.5 mass% or less, Most preferably, it is 1.2 mass% or less.

  When the content of the C = N six-membered ring compound exceeds the above upper limit, when the pentamethylenediamine is used as a resin raw material, the properties of the resulting resin may be lowered.

  More specifically, pentamethylene diisocyanate (described later) is produced using pentamethylenediamine or a salt thereof in which the content of the C = N six-membered ring compound exceeds the upper limit, and further pentamethylene diisocyanate (described later). In the case of producing an isocyanate-modified product (described later), the reaction rate of pentamethylene diisocyanate (described later) is not sufficient, and a large amount of catalyst may be required. In some cases, sufficient properties (for example, storage stability) of the resulting isocyanate-modified product (described later) cannot be ensured.

  On the other hand, if the content of the C = N six-membered ring compound is not more than the above upper limit, the resin having excellent properties can be obtained using the pentamethylenediamine as a resin raw material.

  More specifically, for example, if the content of the C = N six-membered ring compound is not more than the above upper limit, pentamethylene diisocyanate that can efficiently produce an isocyanate-modified product (described later) having excellent properties, Can be manufactured.

  The content of the amino group-containing C = N six-membered ring compound with respect to the total amount of pentamethylenediamine or a salt thereof is, for example, 1.5% by mass or less, preferably 1.2% by mass or less, more preferably 1% by mass or less, particularly preferably 0.8% by mass or less.

  Even when the content of the amino group-containing C = N six-membered ring compound exceeds the above upper limit, when the pentamethylenediamine is used as a resin raw material, the properties of the resulting resin may be lowered.

  More specifically, similarly to the above, pentamethylene diisocyanate (described later) is produced using pentamethylenediamine or a salt thereof in which the content of the amino group-containing C═N six-membered ring compound exceeds the upper limit, and In the case of producing an isocyanate-modified product (described later) by reacting the pentamethylene diisocyanate (described later), the reaction rate of pentamethylene diisocyanate (described later) is not sufficient, and a large amount of catalyst is required. In some cases, the physical properties (for example, storage stability) of the resulting isocyanate-modified product (described later) may not be sufficiently ensured.

  On the other hand, if the content of the amino group-containing C = N six-membered ring compound is not more than the above upper limit, the pentamethylenediamine can be used as a resin raw material to obtain a resin having excellent properties.

  More specifically, for example, if the content of the amino group-containing C = N six-membered ring compound is not more than the above upper limit, pentamethylene diisocyanate that can efficiently produce an isocyanate-modified product having excellent properties, Can be manufactured.

  The content of the amino group-free C═N six-membered ring compound with respect to the total amount of pentamethylenediamine or a salt thereof is, for example, 0.5% by mass or less, preferably 0.4% by mass or less, more preferably 0.3 mass% or less, particularly preferably 0.2 mass% or less.

  When the content of the amino group-free C = N six-membered ring compound exceeds the above upper limit, although not described in detail, when the pentamethylenediamine is used as a resin raw material, the properties of the resulting resin are deteriorated. There is a case.

  More specifically, pentamethylene diisocyanate (described later) produced using pentamethylenediamine or a salt thereof in which the content of the amino group-free C = N six-membered ring compound exceeds the above upper limit, or its pentamethylene diisocyanate ( In some cases, the physical properties (for example, mechanical strength, chemical resistance, etc.) of a polyurethane resin obtained by reacting an isocyanate-modified product (described later) with an active hydrogen compound cannot be sufficiently ensured. .

  And in the manufacturing method of the pentamethylenediamine or its salt of this invention, since a pentamethylenediamine or its salt is extracted with a C4-C7 monohydric alcohol, pentamethylenediamine or its salt is extracted efficiently. Furthermore, the content ratio of impurities of pentamethylenediamine or a salt thereof can be reduced.

  Therefore, according to the pentamethylenediamine or a salt thereof of the present invention, a resin having excellent properties can be produced efficiently.

  As a result, the pentamethylenediamine or a salt thereof of the present invention is suitably used as various industrial raw materials, for example, polyurethane raw materials (polyisocyanates), and resin raw materials such as polyamide raw materials, polyimide raw materials, and epoxy raw materials.

  For example, when the pentamethylenediamine of the present invention or a salt thereof is used as a raw material for polyisocyanate, which is a polyurethane raw material, examples of the polyisocyanate include pentamethylene diisocyanate and an isocyanate-modified pentamethylene diisocyanate.

  Pentamethylene diisocyanate is, for example, a cold two-stage method (direct method (phosgenation method)) described in JP-A-7-309827 or a salt formation method, such as JP-A-2004-244349 and JP-A-2003-2003. A method of producing an alkyl carbamate by a method described in JP-A-212835 and the like, and thermally decomposing the alkyl carbamate (carbonate method), for example, JP-A Nos. 55-149241 and 57-114561 The urethane can be produced by the method described, and can be produced by a known method such as a method of thermally decomposing the urethane compound (urea method).

  And such a pentamethylene diisocyanate is used suitably in manufacture of an isocyanate modified body.

  Examples of isocyanate-modified products include pentamethylene diisocyanate multimers (dimers, trimers (for example, polyisocyanates having isocyanurate groups and / or iminooxadiazinedione groups)), biuret-modified products, and the like. (For example, biuret modified product produced by reaction of pentamethylene diisocyanate and water), allophanate modified product (eg, allophanate modified product produced by reaction of pentamethylene diisocyanate and monool or low molecular weight polyol (described later)) Modified polyols (for example, polyol modified products produced by reaction of pentamethylene diisocyanate with low molecular weight polyol (described later) or macropolyol (described later)), oxadiazine trione modified products (for example, pentamethyl) Oxadiazine trione produced by the reaction of carbon diisocyanate with carbon dioxide, etc.), carbodiimide modified products (carbodiimide modified products produced by decarboxylation condensation reaction of pentamethylene diisocyanate), uretdione modified products, uretonimine modified products, etc. .

  The isocyanate-modified product is preferably a trimer of pentamethylene diisocyanate, more preferably a polyisocyanate having an isocyanurate group.

  The polyisocyanate composition is a trimer of pentamethylene diisocyanate obtained by trimerizing the above pentamethylene diisocyanate (for example, a polyisocyanate having an isocyanurate group and / or an iminooxadiazine dione group). Is included.

  A method for trimming pentamethylene diisocyanate is not particularly limited, and examples thereof include a method (urea method) described in JP-A-2-250872.

  In addition, such a polyisocyanate composition may contain, for example, a compound containing a sulfonamide group (for example, aromatic sulfonamide, aliphatic sulfonamide, etc.) as necessary.

  Although not described in detail, a polyurethane resin can be produced by reacting the above pentamethylene diisocyanate and / or isocyanate-modified product (including a polyisocyanate composition) with an active hydrogen compound.

  Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

Measurement methods used in production examples and the like are shown below.
<Reaction yield of pentamethylenediamine (unit: mol%)>
Using L-lysine monohydrochloride (manufactured by Wako Pure Chemical Industries, Ltd.) and purified pentamethylenediamine obtained by (distillation of pentamethylenediamine) described below, under the following HPLC (high performance liquid chromatograph) analysis conditions The concentration of pentamethylenediamine was calculated from the calibration curve created from the area value of the obtained chromatograph, and the ratio of the concentration of pentamethylenediamine to the total concentration of L-lysine monohydrochloride and pentamethylenediamine was calculated as pentamethylenediamine. Reaction yield.

Column: Asahipak ODP-50 4E (Showa Denko)
Column temperature: 40 ° C
Eluent: 0.2 mol / L sodium phosphate (pH 7.7) +2.3 mmol / L 1-octane sulfonate sodium flow rate: 0.5 mL / min
For detection of L-lysine monohydrochloride and pentamethylenediamine, a post-column derivatization method using orthophthalaldehyde [J. Chromatogr. 83, 353-355 (1973)].
<Puramethylenediamine purity (unit: mass%)>
The purity of pentamethylenediamine was calculated using a calibration curve created from the area values of the gas chromatogram obtained under the following gas chromatographic analysis conditions using the purified pentamethylenediamine obtained in (Distillation of pentamethylenediamine) described later. .

Apparatus; GC-6890 (manufactured by Agilent Technologies)
Column; WCOT FUSED SILICA CP-SIL 8CB FOR AMINES (Varian)
Oven temperature: held at 40 ° C. for 3 minutes, heated from 40 ° C. to 300 ° C. at 10 ° C./min, held at 300 ° C. for 11 minutes Inlet temperature: 250 ° C.
Detector temperature: 280 ° C
Carrier gas; helium detection method; FID
<Extraction rate (unit: mass%)>
In order to determine the extraction rate of pentamethylenediamine with the extraction solvent, the same measurement as the above (purity of pentamethylenediamine) was performed, the concentration of pentamethylenediamine in the aqueous solution of pentamethylenediamine before the extraction operation, and the extraction solvent after the extraction operation The concentration of pentamethylenediamine was measured.

And the extraction rate was computed with the following formula | equation.
(A) Mass of pentamethylenediamine in extraction solvent = Pentamethylenediamine concentration in extraction solvent × Mass of extraction solvent / 100
(B) Mass of pentamethylenediamine in the prepared pentamethylenediamine aqueous solution = diaminopentane concentration of pentamethylenediamine aqueous solution before extraction operation × mass of prepared pentamethylenediamine aqueous solution / 100
Extraction rate (mass%) = (a) / (b) × 100
<Total content (unit: mass%) of the compound having a cyclic structure containing a C = N bond>
It calculated | required by the total value of (2,3,4,5-tetrahydropyridine density | concentration) mentioned later and (2- (aminomethyl) -3,4,5,6-tetrahydropyridine density | concentration).
<2,3,4,5-tetrahydropyridine concentration (unit: mass%)>
Area value of gas chromatogram obtained by measurement under the same conditions as described in (Pentamethylenediamine purity) using 2,3,4,5-tetrahydropyridine obtained in (Structural analysis of unknown substance) described later The 2,3,4,5-tetrahydropyridine concentration was calculated from the calibration curve created from
<2- (Aminomethyl) -3,4,5,6-tetrahydropyridine concentration (unit: mass%)>
Using 2- (aminomethyl) -3,4,5,6-tetrahydropyridine obtained in (Structural analysis of unknown substance) described later, and obtained by measurement under the same conditions as described in (Puramethylenediamine purity). The concentration of 2- (aminomethyl) -3,4,5,6-tetrahydropyridine was calculated from a calibration curve created from the area values of the obtained gas chromatogram.
<Puramethylene diisocyanate purity (unit: mass%)>
The purity of pentamethylene diisocyanate was calculated from the isocyanate group concentration measured by the n-dibutylamine method in accordance with JIS K-1556 using a potentiometric titrator.
<Pentamethylene diisocyanate concentration (unit: mass%)>
Using the pentamethylene diisocyanate (a) obtained in Example 1 to be described later, a calibration curve prepared from the area value of the chromatogram obtained under the following HPLC analysis conditions was used to determine the pentamethylene diisocyanate in the polyisocyanate composition. Concentration was calculated.

Equipment; Prominence (manufactured by Shimadzu Corporation)
1) Pump LC-20AT
2) Degasser DGU-20A3
3) Autosampler SIL-20A
4) Column thermostat COT-20A
5) Detector SPD-20A
Column; SHISEIDO SILICA SG-120
Column temperature: 40 ° C
Eluent: n-hexane / methanol / 1,2-dichloroethane = 90/5/5 (volume ratio)
Flow rate: 0.2 mL / min
Detection method: UV 225 nm
<Conversion rate of isocyanate group (unit:%)>
The conversion rate of the isocyanate group is the ratio of the area of the peak on the high molecular weight side of the peak of pentamethylene diisocyanate to the total peak area, based on the chromatogram obtained under the following GPC measurement conditions, as the conversion rate of the isocyanate group. .

Apparatus; HLC-8020 (manufactured by Tosoh Corporation)
Column; G1000HXL, G2000HXL and G3000HXL (trade name, manufactured by Tosoh Corporation) connected in series Column temperature: 40 ° C
Eluent: Tetrahydrofuran Flow rate: 0.8 mL / min
Detection method: Differential refractive index Standard material: Polyethylene oxide (manufactured by Tosoh Corporation, trade name: TSK standard polyethylene oxide)
<Isocyanate group concentration (unit: mass%)>
The isocyanate group concentration of the polyisocyanate composition was measured by an n-dibutylamine method according to JIS K-1556 using a potentiometric titrator.
<Viscosity (unit: mPa · s)>
The viscosity at 25 ° C. of the polyisocyanate composition was measured using an E-type viscometer TV-30 manufactured by Toki Sangyo Co., Ltd.
<Hue (unit: APHA)>
The hue of the polyisocyanate composition was measured by a method based on JIS K-0071.
(Distillation of pentamethylenediamine)
Into a four-necked flask equipped with a thermometer, a distillation tower, a cooling pipe, and a nitrogen introduction pipe, pentamethylene diamine (manufactured by Tokyo Chemical Industry Co., Ltd.) is charged and further refluxed under conditions of a tower top temperature of 111 to 115 ° C. and 10 KPa. Then, rectification was performed to obtain purified pentamethylenediamine. The pentamethylenediamine purified by distillation had a gas chromatography area ratio of 100%.

Preparation Example 1 (Preparation of cell disruption solution)
(Cloning of lysine decarboxylase gene (cadA))
Genomic DNA prepared from Escherichia coli W3110 strain (ATCC 27325) according to a conventional method was used as a PCR template.

  As primers for PCR, oligonucleotides having the nucleotide sequences shown in SEQ ID NOs: 1 and 2 designed based on the nucleotide sequence of lysine decarboxylase gene (cadA) (GenBank Accession No. AP009048) (consigned to Invitrogen) Synthesized). These primers have restriction enzyme recognition sequences for KpnI and XbaI, respectively, near the 5 'end.

  Using 25 μL of a PCR reaction solution containing 1 ng / μL of genomic DNA and 0.5 pmol / μL of each primer, denaturation: 94 ° C., 30 seconds, annealing: 55 ° C., 30 seconds, extension reaction: 68 ° C., from 2 minutes PCR was performed under the following reaction cycle of 30 cycles.

  The PCR reaction product and plasmid pUC18 (Takara Shuzo) were digested with KpnI and XbaI and ligated using Ligation High (Toyobo), then Escherichia coli DH5α (Toyobo) Made). The transformant was cultured on an LB agar medium containing 100 μg / mL of ampicillin (Am) and X-Gal (5-bromo-4-chloro-3-indolyl-β-D-galactoside), and was Am-resistant and white colony. The resulting transformant was obtained. A plasmid was extracted from the transformant thus obtained.

  In accordance with the usual method for determining the base sequence, it was confirmed that the base sequence of the DNA fragment introduced into the plasmid was the base sequence shown in SEQ ID NO: 3.

The obtained plasmid having DNA encoding lysine decarboxylase was named pCADA. By culturing E. coli transformed with pCADA, lysine decarboxylase having the amino acid sequence shown in SEQ ID NO: 4 could be produced.
(Production of transformants)
Escherichia coli W3110 strain was transformed with pCADA by a conventional method, and the resulting transformant was named W / pCADA.

  This transformant was inoculated into 500 ml of LB medium containing 100 μg / mL of Am in a baffled Erlenmeyer flask, shake-cultured at 30 ° C. until OD (660 nm) became 0.5, and then IPTG (isopropyl-β-thio). Galactopyranoside) was added at 0.1 mmol / L, and the mixture was further cultured with shaking for 14 hours. The culture solution was centrifuged at 8000 rpm for 20 minutes to obtain bacterial cells. The cells were suspended in a 20 mmol / L sodium phosphate buffer (pH 6.0), and then ultrasonically disrupted to prepare a cell disruption solution.

Preparation Example 2 (Production of pentamethylenediamine aqueous solution)
Into the flask, L-lysine monohydrochloride (manufactured by Wako Pure Chemical Industries, so that the final concentration is 45% by mass) and pyridoxal phosphate (manufactured by Wako Pure Chemical Industries, Ltd.), the final concentration is 0.15 mmol / L. Next, 120 parts by mass of the substrate solution prepared as described above was added, and the reaction was started by adding the above-mentioned W / pCADA microbial cell disruption solution (the weight of charged dry cells in terms of 0.3 g). The pH of the reaction solution was adjusted with 6 mol / L hydrochloric acid to pH 6. The reaction yield of pentamethylenediamine after 24 hours had reached 99%. , Adjusted to pH 2 with 6 mol / L hydrochloric acid, added 0.6 parts by mass of activated carbon (powdered activated carbon PM-SX manufactured by Mikura Kasei Co., Ltd.), stirred at 25 ° C. for 1 hour, and then filtered paper (ADVANTEC) Made by 5C) And. Then adjusted to pH12 The filtrate with sodium hydroxide to obtain pentamethylene diamine solution (17.0% by weight aqueous solution).

Example 1 (Preparation of pentamethylenediamine (a))
In a separatory funnel, 100 parts by mass of the pentamethylenediamine aqueous solution obtained in Preparation Example 2 and 100 parts by mass of n-butanol (extraction solvent) were charged, mixed for 10 minutes, and then allowed to stand for 30 minutes. Subsequently, the organic layer (n-butanol containing pentamethylenediamine) was extracted and the extraction rate was measured. As a result, the extraction rate was 91.8%.

  Next, 100 parts by mass of an organic layer extract (n-butanol containing pentamethylenediamine) was charged into a four-necked flask equipped with a thermometer, a distillation column, a cooling tube, and a nitrogen introduction tube, and oil was added under a reduced pressure of 10 kPa. N-butanol was distilled off at a bath temperature of 120 ° C. to obtain pentamethylenediamine (a) having a purity of 99.9% by mass.

  That is, pentamethylenediamine (a) could be prepared by solvent extraction of an aqueous solution of pentamethylenediamine with n-butanol and further distilling off n-butanol.

  The obtained pentamethylenediamine (a) contained impurities including 2,3,4,5-tetrahydropyridine.

Example 2 (Preparation of pentamethylenediamine (b))
In a separatory funnel, 100 parts by mass of the pentamethylenediamine aqueous solution obtained in Preparation Example 2 and 100 parts by mass of isobutanol (extraction solvent) were charged, mixed for 10 minutes, and then allowed to stand for 30 minutes. Next, the organic layer (isobutanol containing pentamethylenediamine) was extracted and the extraction rate was measured. As a result, the extraction rate was 86.0%.

  Next, isobutanol was distilled off under the same conditions and operations as in Example 1 to obtain pentamethylenediamine (b) having a purity of 99.7% by mass.

  That is, pentamethylenediamine (b) could be prepared by solvent extraction of an aqueous solution of pentamethylenediamine with isobutanol and further distilling off isobutanol.

  The obtained pentamethylenediamine (b) contained impurities including 2,3,4,5-tetrahydropyridine.

Example 3 (Preparation of pentamethylenediamine (c))
The separatory funnel was charged with 100 parts by mass of the pentamethylenediamine aqueous solution obtained in Preparation Example 2 and 100 parts by mass of n-heptanol (extraction solvent), mixed for 10 minutes, and then allowed to stand for 30 minutes. Subsequently, the organic layer (n-heptanol containing pentamethylenediamine) was extracted and the extraction rate was measured. As a result, the extraction rate was 68.5%.

  Subsequently, n-heptanol was distilled off under the same conditions and operations as in Example 1 to obtain pentamethylenediamine (c) having a purity of 99.6% by mass.

  That is, pentamethylenediamine (c) could be prepared by solvent extraction of an aqueous pentamethylenediamine solution with n-heptanol and further distilling off n-heptanol.

  The obtained pentamethylenediamine (c) contained impurities including 2,3,4,5-tetrahydropyridine.

Comparative Example 1 (Preparation of pentamethylenediamine (d))
In a separatory funnel, 100 parts by mass of the pentamethylenediamine aqueous solution obtained in Preparation Example 2 and 100 parts by mass of n-octanol (extraction solvent) were charged, mixed for 10 minutes, and then allowed to stand for 30 minutes. Subsequently, the organic layer (n-octanol containing pentamethylenediamine) was extracted and the extraction rate was measured. As a result, the extraction rate was 60.5%.

  Subsequently, pentamethylenediamine was distilled off under the same conditions and operations as in Example 1. As a result, pentamethylenediamine (d) having a purity of 99.8% by mass was obtained.

  That is, pentamethylenediamine (d) could be prepared by distilling pentamethylenediamine after solvent extraction of the aqueous solution of pentamethylenediamine with n-octanol.

  The obtained pentamethylenediamine (d) contained impurities including 2,3,4,5-tetrahydropyridine.

Comparative Example 2 (Preparation of pentamethylenediamine (e))
In a separatory funnel, 100 parts by mass of the pentamethylenediamine aqueous solution obtained in Preparation Example 2 and 100 parts by mass of chloroform (extraction solvent) were charged, mixed for 10 minutes, and then allowed to stand for 30 minutes. Next, the organic layer (chloroform containing pentamethylenediamine) was extracted and the extraction rate was measured. As a result, the extraction rate was 62.0%.

  Subsequently, chloroform was distilled off under the same conditions and operations as in Example 1 to obtain pentamethylenediamine (e) having a purity of 97.8% by mass.

  That is, pentamethylenediamine (e) could be prepared by subjecting an aqueous pentamethylenediamine solution to solvent extraction with chloroform and further distilling off chloroform.

  The obtained pentamethylenediamine (e) contained impurities including 2,3,4,5-tetrahydropyridine and unknown substances.

Example 4 (Preparation of pentamethylenediamine (f))
Into a four-necked flask equipped with a stirrer, a thermometer, a reflux tube, and a nitrogen introduction tube was charged 110 parts by mass of the pentamethylenediamine aqueous solution obtained in Preparation Example 2, and water was distilled off at 38 kPa and 80 ° C. 19.6 mass% pentamethylenediamine aqueous solution was obtained.

  In a separatory funnel, 100 parts by mass of the pentamethylenediamine aqueous solution and 100 parts by mass of n-butanol (extraction solvent) were charged, mixed for 10 minutes, and then allowed to stand for 30 minutes. Subsequently, the organic layer (n-butanol containing pentamethylenediamine) was extracted and the extraction rate was measured. As a result, the extraction rate was 93.4%.

  Subsequently, n-butanol was distilled off under the same conditions and operations as in Example 1 to obtain pentamethylenediamine (f) having a purity of 99.6% by mass.

  The obtained pentamethylenediamine (f) contained impurities including 2,3,4,5-tetrahydropyridine.

Example 5 (Preparation of pentamethylenediamine (g))
A four-necked flask equipped with a stirrer, a thermometer, a reflux tube, and a nitrogen introduction tube was charged with 110 parts by mass of the pentamethylenediamine aqueous solution obtained in Preparation Example 2, and the atmospheric pressure and the reflux temperature (105 ° C.) The water was distilled off to obtain a 19.4 mass% pentamethylenediamine aqueous solution.

  In a separatory funnel, 100 parts by mass of the pentamethylenediamine aqueous solution and 100 parts by mass of n-butanol (extraction solvent) were charged, mixed for 10 minutes, and then allowed to stand for 30 minutes. Subsequently, the organic layer (n-butanol containing pentamethylenediamine) was extracted and the extraction rate was measured. As a result, the extraction rate was 89.2%.

  Subsequently, n-butanol was distilled off under the same conditions and operations as in Example 1 to obtain pentamethylenediamine (g) having a purity of 99.2% by mass.

  The obtained pentamethylenediamine (g) contained impurities including 2,3,4,5-tetrahydropyridine.

Test Example 1 (Structural analysis of unknown substance contained in pentamethylenediamine)
Impurities contained in pentamethylenediamine were separated using a solid-phase extraction cartridge (VARIAN, model 1225-6067), and structural analysis was performed by GC-MS analysis and NMR analysis.

  In order to condition the solid phase extraction cartridge, a mixed solution of 50 mL of methanol and 450 mL of chloroform was passed. After dissolving 500 mg of pentamethylenediamine (e) in a mixed solution of 50 mL of methanol and 450 mL of chloroform, the solution was passed through a solid phase extraction cartridge to obtain an effluent. Subsequently, the mixed solution of methanol and chloroform at the ratio shown below was passed through 5 times, and the effluent from the solid phase extraction cartridge was collected.

First time: Mixed solution of methanol 100 mL and chloroform 900 mL Second time; Mixed solution of methanol 50 mL and chloroform 450 mL Third time: Mixed solution of methanol 100 mL and chloroform 400 mL Fourth time: Mixed solution of methanol 100 mL and chloroform 400 mL Fifth time; Mixed solution of chloroform (400 mL) The solvent was removed from the first and second effluents by nitrogen purge, and the resulting compound was measured under the conditions of GC-MS analysis 1 below. As a result, pentamethylenediamine was not detected, and 2,3,4,5-tetrahydropyridine having an area ratio of 99% was detected.

  The compound obtained from the third time was measured by GC-MS analysis 1 in the same manner as in the first and second effluents. As a result, pentamethylenediamine was not detected, but 2,3,4,5-tetrahydropyridine and an unknown substance were detected.

  The compounds obtained from the fourth and fifth times were measured by GC-MS analysis 1 in the same manner as in the first and second effluents. As a result, pentamethylenediamine and 2,3,4,5-tetrahydropyridine were not detected, and an unknown substance with an area ratio of 99% was detected.

  The chromatogram of GC-MS analysis 1 of the 4th and 5th compound is shown in FIG.

  In FIG. 1, the peak at 4:08 is chloroform and the peak at 13:26 is an unknown substance.

  Moreover, the spectrum of the GC-MS analysis 1 of the 4th and 5th time compound is shown in FIG.

  Next, in order to determine the chemical formula of the unknown substance, the distilled and purified pentamethylenediamine obtained in the above (distillation of pentamethylenediamine) was added as a standard substance to the fourth and fifth compounds, and the following GC-MS analysis 2 It measured on condition of this. The obtained chromatogram is shown in FIG.

  In FIG. 3, the 11:61 peak is pentamethylenediamine, and the 13:34 peak is an unknown substance.

From the results of GC-MS analysis 2, it was confirmed that the chemical formula of the unknown substance was C ₆ H ₁₂ N ₂ .

  Subsequently, in order to perform the structural analysis of the unknown substance, the fourth and fifth compounds were measured under the following NMR analysis conditions.

4 shows the results of ¹ H-NMR of the unknown substance, FIG. 5 shows the results of ¹³ C-NMR, FIG. 6 shows the results of COSY, FIG. 7 shows the results of HMQC, and FIGS. 8 and 9 show the results of HMBC. Shown in FIG. 9 shows an enlarged view of the result shown in FIG.

  From the results of GC-MS analysis and NMR analysis, it was confirmed that the unknown substance was 2- (aminomethyl) -3,4,5,6-tetrahydropyridine.

In addition, the apparatus and conditions of GC-MS analysis and NMR analysis are shown below.
<GC-MS analysis 1>
Device: Q1000GC K9 (manufactured by JEOL Ltd.)
Ionization method; EI
Column; WCOT FUSED SILICA CP-SIL 8CB FOR AMINES (Varian), 0.25 mmφ × 30 m
Oven temperature: held at 40 ° C. for 3 minutes, heated from 40 ° C. to 300 ° C. at 10 ° C./min, held at 300 ° C. for 11 minutes Inlet temperature: 250 ° C.
He flow rate: 0.7 mL / min
Injection mode; split <GC-MS analysis 2>
Device: JMS-T100GC (manufactured by JEOL)
Ionization method; FI
Column; WCOT FUSED SILICA CP-SIL 8CB FOR AMINES (Varian), 0.25 mmφ × 30 m
Oven temperature: held at 40 ° C. for 3 minutes, heated from 40 ° C. to 300 ° C. at 10 ° C./min, held at 300 ° C. for 11 minutes Inlet temperature: 250 ° C.
He flow rate: 0.7 mL / min
Injection mode; split <NMR analysis>
Equipment: Nuclear magnetic resonance system ECA500 (manufactured by JEOL)
Measurement method: ¹ H-NMR, ¹³ C-NMR, COSY, HMQC, HMBC
Test Example 2 (Measurement of impurity concentration)
The concentration of impurities (2,3,4,5-tetrahydropyridine and 2- (aminomethyl) -3,4,5,6-tetrahydropyridine) contained in the pentamethylenediamine obtained in each example is Calculation was performed by the following method.

  That is, the purified pentamethylene obtained by the above-mentioned (distillation of pentamethylenediamine) so that the concentration of 2,3,4,5-tetrahydropyridine was 2% by mass, 0.5% by mass, and 0.05% by mass. Diamine and 2,3,4,5-tetrahydropyridine obtained in Test Example 1 were mixed. Next, as an internal standard substance, a certain amount of o-dichlorobenzene (hereinafter sometimes abbreviated as ODCB) and a solution of methanol as a solvent were added three times to the purity of pentamethylenediamine. Calibration curve with the same conditions as described, with the horizontal axis representing the area ratio of ODCB and 2,3,4,5-tetrahydropyridine and the vertical axis representing the concentration ratio of ODCB to 2,3,4,5-tetrahydropyridine It was created.

  A certain amount of ODCB and a solvent methanol were added to the pentamethylenediamine obtained in each example, and the measurement was performed under the same conditions as described in (Pentamethylenediamine purity). The 5-tetrahydropyridine concentration was calculated.

  The concentration of 2- (aminomethyl) -3,4,5,6-tetrahydropyridine was calculated in the same manner as the 2,3,4,5-tetrahydropyridine concentration calculation method.

  As a result, the 2,3,4,5-tetrahydropyridine concentration of pentamethylenediamine (a) was 0.1% by mass, and the 2- (aminomethyl) -3,4,5,6-tetrahydropyridine concentration was detected. It was less than the limit (detection limit: 0.0006% by mass), and the total amount thereof (total amount in the detectable range) was 0.1% by mass.

  The pentamethylenediamine (b) has a 2,3,4,5-tetrahydropyridine concentration of 0.1% by mass and a 2- (aminomethyl) -3,4,5,6-tetrahydropyridine concentration below the detection limit ( The detection limit was 0.0006% by mass), and the total amount thereof (total amount in the detectable range) was 0.1% by mass.

  The pentamethylenediamine (c) has a 2,3,4,5-tetrahydropyridine concentration of 0.1% by mass and a 2- (aminomethyl) -3,4,5,6-tetrahydropyridine concentration below the detection limit ( The detection limit was 0.0006% by mass), and the total amount thereof (total amount in the detectable range) was 0.1% by mass.

  The pentamethylenediamine (d) has a 2,3,4,5-tetrahydropyridine concentration of 0.1% by mass and a 2- (aminomethyl) -3,4,5,6-tetrahydropyridine concentration below the detection limit ( The detection limit was 0.0006% by mass), and the total amount thereof (total amount in the detectable range) was 0.1% by mass.

  The 2,3,4,5-tetrahydropyridine concentration of pentamethylenediamine (e) is 0.6% by mass, and the concentration of 2- (aminomethyl) -3,4,5,6-tetrahydropyridine is 1.6% by mass. The total amount thereof (total amount in the detectable range) was 2.2% by mass.

  The concentration of 2,3,4,5-tetrahydropyridine in pentamethylenediamine (f) is 0.3% by mass, and the concentration of 2- (aminomethyl) -3,4,5,6-tetrahydropyridine is below the detection limit. The total amount thereof (total amount in the detectable range) was 0.3% by mass.

  The pentamethylenediamine (g) has a 2,3,4,5-tetrahydropyridine concentration of 0.6% by mass and a 2- (aminomethyl) -3,4,5,6-tetrahydropyridine concentration below the detection limit. The total amount thereof (total amount in the detectable range) was 0.6% by mass.

  Table 1 shows the concentration of each impurity in each of these pentamethylenediamines.

Production Example 1 (Production of pentamethylene diisocyanate (a))
A mixture of 51 parts by mass of pentamethylenediamine (a), 72 parts by mass of urea and 222 parts by mass of n-butanol was charged into a SUS autoclave equipped with a pressure control valve, a reflux condenser, a gas-liquid separator, and a stirrer. The gas was allowed to react for 3 hours while adjusting the internal pressure with a pressure control valve so as to keep the reaction temperature at 215 ° C. while stirring the gas at a flow rate of 0.3 L per minute at 500 rpm. The obtained reaction solution was distilled under reduced pressure at 0.5 KPa and 150 ° C. to cut light boiling components, and 150 parts by mass of bis (butoxycarbonylamino) pentane having a purity of 96.1% was obtained.

  Next, a four-necked flask equipped with a rectifying column equipped with a stirrer, a thermometer and a cooler was used as a reactor, warm water at 80 ° C. was passed through the cooler, and the receiver was passed through a cold trap cooled with cold acetone. Connected to vacuum line. The flask was charged with 70 parts by weight of bis (butoxycarbonylamino) pentane, 70 parts by weight of barrel process oil B-30 (manufactured by Matsumura Oil Co., Ltd.), and 0.14 parts by weight of dibutyltin dilaurate. After the reaction system was purged with nitrogen, the pressure was reduced to 3.0 kPa, and the reaction solution was heated to 250 ° C. and reacted for 2 hours. After completion of the reaction, the reaction solution collected in the receiver was quantified by gas chromatography. As a result, pentamethylene diisocyanate (a) having a purity of 99.9% by mass was obtained.

  The analysis conditions for gas chromatography are shown below.

Equipment: GC-14B (manufactured by Shimadzu Corporation)
Column; UA-20EX-2.0F, 1.2 mmφ × 20 m (manufactured by Frontier Laboratories)
Oven temperature: held at 100 ° C. for 2 minutes, raised from 100 ° C. to 240 ° C. at 10 ° C./min, held at 240 ° C. for 14 minutes Inlet temperature: 250 ° C.
Detector temperature: 250 ° C
Carrier gas; helium detection method; FID
Production Example 2 (Production of pentamethylene diisocyanate (b))
2000 parts by mass of orthodichlorobenzene was charged into a jacketed pressurized reactor equipped with an electromagnetic induction stirrer, an automatic pressure control valve, a thermometer, a nitrogen introduction line, a phosgene introduction line, a condenser, and a raw material feed pump. Subsequently, 2300 mass parts of phosgene was added from the phosgene introduction line, and stirring was started. Cold water was passed through the reactor jacket to maintain the internal temperature at about 10 ° C. A solution obtained by dissolving 400 parts by mass of pentamethylenediamine (a) in 2600 parts by mass of orthodichlorobenzene was fed with a feed pump over 60 minutes, and cold phosgenation was started at 30 ° C. or lower and normal pressure. After the feed was completed, the inside of the pressurized reactor became a pale brown white slurry.

  Next, the internal liquid of the reactor was pressurized to 0.25 MPa while gradually raising the temperature to 160 ° C., and further subjected to thermal phosgenation at a pressure of 0.25 MPa and a reaction temperature of 160 ° C. for 90 minutes. During the thermal phosgenation, 1100 parts by mass of phosgene was further added. During the thermal phosgenation, the liquid in the pressurized reactor became a light brown clear solution. After the completion of the thermal phosgenation, nitrogen gas was aerated at 100 to 140 ° C. and degassed.

  Subsequently, after ortho-dichlorobenzene was distilled off under reduced pressure, pentamethylene diisocyanate was also distilled off under reduced pressure.

  Subsequently, the distilled pentamethylene diisocyanate was charged into a four-necked flask equipped with a stirrer, a thermometer, a reflux tube, and a nitrogen introduction tube, and at 200 ° C. under atmospheric pressure while introducing nitrogen. Heat treatment was performed for a time.

  Next, the heat-treated pentamethylene diisocyanate was charged into a glass flask, and a distillation tube filled with 4 elements of a packing (manufactured by Sumitomo Heavy Industries, Ltd., trade name: Sumitomo / Sulzer Lab Packing EX type), reflux ratio Further reflux under conditions of 127 to 132 ° C. and 2.7 KPa using a distillation tower equipped with a control timer (manufactured by Shibata Kagaku Co., Ltd., trade name: distillation head K type) and a rectifier equipped with a condenser. Then, rectification was performed to obtain 450 parts by mass of pentamethylene diisocyanate (b) having a purity of 99.9% by mass.

Production Example 3 (Production of pentamethylene diisocyanate (c))
A pentamethylene diisocyanate (c) having a purity of 99.9% by mass was obtained under the same conditions and operation as in Production Example 1, except that pentamethylenediamine (b) was used instead of pentamethylenediamine (a).

Production Example 4 (Production of pentamethylene diisocyanate (d))
A pentamethylene diisocyanate (d) having a purity of 99.1% by mass was obtained under the same conditions and operation as in Production Example 1, except that pentamethylenediamine (e) was used instead of pentamethylenediamine (a).

Production Example 5 (Production of pentamethylene diisocyanate (e))
A pentamethylene diisocyanate (e) having a purity of 99.0% by mass was obtained under the same conditions and operations as in Production Example 2, except that pentamethylenediamine (e) was used instead of pentamethylenediamine (a).

Synthesis Example 1 (Production of polyisocyanate composition (A))
In a four-necked flask equipped with a stirrer, thermometer, reflux tube, and nitrogen introduction tube, 500 parts by mass of pentamethylene diisocyanate (a), 1.0 part by mass of isobutyl alcohol, 2,6-di (tert- (Butyl) -4-methylphenol (0.25 part by mass) and tris (tridecyl) phosphite (0.25 part by mass) were charged and reacted at 80 ° C. for 3 hours. After the temperature of this solution was lowered to 60 ° C., 0.1 part by mass of N- (2-hydroxypropyl) -N, N, N-trimethylammonium-2-ethylhexanoate was added as a trimerization catalyst. After reacting for 1 hour, 0.12 parts by mass of o-toluenesulfonamide was added (conversion rate of isocyanate group: 10% by mass). The obtained reaction liquid was passed through a thin film distillation apparatus (vacuum degree 0.093 KPa, temperature 150 ° C.) to remove unreacted 1,5-pentamethylene diisocyanate, and 100 parts by mass of the obtained composition, 0.02 parts by mass of o-toluenesulfonamide was added to obtain a polyisocyanate composition (A).

  The polyisocyanate composition (A) had a pentamethylene diisocyanate concentration of 0.3% by mass, an isocyanate group concentration 1 of 25.2% by mass, a viscosity 1 at 25 ° C. of 1700 mPa · s, and a hue 1 of APHA20. These measured values are shown in Table 2 as measured values before the heating acceleration test.

  Next, the polyisocyanate composition (A) was transferred to a metal container, purged with nitrogen, and left in an oven at 60 ° C. for 4 days to carry out a heating acceleration test. The polyisocyanate composition after the test had an isocyanate group concentration 2 of 24.7% by mass, a viscosity 2 at 25 ° C. of 1870 mPa · s, and a hue 2 of APHA30. These measured values are measured values after the heating acceleration test and are shown in Table 2.

Synthesis Example 2 (Production of polyisocyanate composition (B))
Instead of pentamethylene diisocyanate (a), pentamethylene diisocyanate (b) was used to obtain a polyisocyanate composition (B) in the same manner as in Synthesis Example 1.

  The polyisocyanate composition (B) had a pentamethylene diisocyanate concentration of 0.5% by mass, an isocyanate group concentration 1 of 25.0% by mass, a viscosity 1 at 25 ° C. of 1790 mPa · s, and a hue 1 of APHA20. These measured values are shown in Table 2 as measured values before the heating acceleration test.

  Next, the polyisocyanate composition (B) was transferred to a metal container, purged with nitrogen, and left in an oven at 60 ° C. for 4 days to conduct a heating acceleration test. The polyisocyanate composition after the test had an isocyanate group concentration 2 of 24.5% by mass, a viscosity 2 at 25 ° C. of 1990 mPa · s, and a hue 2 of APHA30. These measured values are measured values after the heating acceleration test and are shown in Table 2.

Synthesis Example 3 (Production of polyisocyanate composition (C))
Instead of pentamethylene diisocyanate (a), pentamethylene diisocyanate (c) was used to obtain a polyisocyanate composition (C) in the same manner as in Synthesis Example 1.

  The polyisocyanate composition (C) had a pentamethylene diisocyanate concentration of 0.5% by mass, an isocyanate group concentration 1 of 25.1% by mass, a viscosity 1 at 25 ° C. of 1750 mPa · s, and a hue 1 of APHA20. These measured values are shown in Table 2 as measured values before the heating acceleration test.

  Subsequently, the polyisocyanate composition (C) was transferred to a metal container, purged with nitrogen, and left in an oven at 60 ° C. for 4 days to perform a heating acceleration test. The polyisocyanate composition after the test had an isocyanate group concentration 2 of 24.6% by mass, a viscosity 2 at 25 ° C. of 1940 mPa · s, and a hue 2 of APHA30. These measured values are measured values after the heating acceleration test and are shown in Table 2.

Comparative Synthesis Example 1 (Production of polyisocyanate composition (D))
In place of pentamethylene diisocyanate (a), pentamethylene diisocyanate (d) was used, and an isocyanuration reaction was performed in the same manner as in Synthesis Example 1, but it was confirmed that the reaction rate was low from the measurement of isocyanate group concentration. Therefore, 0.2 parts by mass of trimethyl-N-2-hydroxypropylammonium · 2-ethylhexanoate was added.

  After measurement of the isocyanate group concentration, 0.1 parts by mass of trimethyl-N-2-hydroxypropylammonium · 2-ethylhexanoate was further added, and the reaction was continued for 3 hours to obtain a polyisocyanate composition (D).

    The polyisocyanate composition (D) had a pentamethylene diisocyanate concentration of 0.7% by mass, an isocyanate group concentration 1 of 20.2% by mass, a viscosity 1 at 25 ° C. of 2200 mPa · s, and a hue 1 of APHA100. These measured values are shown in Table 2 as measured values before the heating acceleration test.

  Next, the polyisocyanate composition (D) was transferred to a metal container, purged with nitrogen, and allowed to stand in an oven at 60 ° C. for 4 days, and a heating acceleration test was performed. The polyisocyanate composition after the test had an isocyanate group concentration 2 of 17.2% by mass, a viscosity 2 at 25 ° C. of 2950 mPa · s, and a hue 2 of APHA150. These measured values are measured values after the heating acceleration test and are shown in Table 2.

Comparative Synthesis Example 2 (Production of polyisocyanate composition (E))
Instead of pentamethylene diisocyanate (a), pentamethylene diisocyanate (e) was used, and an isocyanuration reaction was performed in the same manner as in Synthesis Example 1, but it was confirmed that the reaction rate was low from the measurement of isocyanate group concentration. Therefore, 0.2 parts by mass of trimethyl-N-2-hydroxypropylammonium · 2-ethylhexanoate was added.

  After measurement of the isocyanate group concentration, 0.1 parts by mass of trimethyl-N-2-hydroxypropylammonium · 2-ethylhexanoate was further added, and the reaction was continued for 3 hours to obtain a polyisocyanate composition (E).

  The polyisocyanate composition (E) had a pentamethylene diisocyanate concentration of 0.8% by mass, an isocyanate group concentration 1 of 19.8% by mass, a viscosity 1 at 25 ° C. of 2380 mPa · s, and a hue 1 of APHA100. These measured values are shown in Table 2 as measured values before the heating acceleration test.

  Subsequently, the polyisocyanate composition (E) was transferred to a metal container, purged with nitrogen, and left in an oven at 60 ° C. for 4 days to carry out a heating acceleration test. The polyisocyanate composition after the test had an isocyanate group concentration 2 of 16.6% by mass, a viscosity 2 at 25 ° C. of 3240 mPa · s, and a hue 2 of APHA150. These measured values are measured values after the heating acceleration test and are shown in Table 2.

Claims (7)

From an aqueous solution containing pentamethylenediamine or a salt thereof, pentamethylenediamine or a salt thereof is obtained.
A method for producing pentamethylenediamine or a salt thereof, wherein the extraction is performed with a monohydric alcohol having 4 to 7 carbon atoms.   The pentamethylenediamine or a salt thereof according to claim 1, wherein the pentamethylenediamine or a salt thereof is extracted without heat-treating an aqueous solution containing pentamethylenediamine or a salt thereof at 90 ° C or higher. Method.   The method for producing pentamethylenediamine or a salt thereof according to claim 1 or 2, wherein the monohydric alcohol is a linear monohydric alcohol.   The production of pentamethylenediamine or a salt thereof according to any one of claims 1 to 3, wherein an aqueous solution containing pentamethylenediamine or a salt thereof is obtained by a decarboxylase reaction of lysine or a salt thereof. Method.   Pentamethylenediamine or a salt thereof obtained by the method for producing pentamethylenediamine or a salt thereof according to any one of claims 1 to 4.   The content of the nitrogen-containing six-membered ring compound having an amino group and a C = N bond with respect to the total amount of pentamethylenediamine or a salt thereof is 1.5% by mass or less. Of pentamethylenediamine or a salt thereof.   7. The nitrogen-containing six-membered ring compound having an amino group and a C═N bond is 2- (aminomethyl) -3,4,5,6-tetrahydropyridine. Of pentamethylenediamine or a salt thereof.