Organic acid prepolymer composition, organic acid polymer, and method for producing the same

Abstract

The present invention relates to a method for producing an organic acid prepolymer and an organic acid polymer by polymerizing and washing a low-purity organic acid composition containing an inorganic compound, and to the organic acid prepolymer composition and the organic acid polymer.

Description

Technical Field

[0001] Cross-reference of related applications This application claims the benefit of priority based on Korean Patent Application Nos. 10-2024-0010984 filed on January 24, 2024, 10-2024-0134813 filed on October 4, 2024, 10-2024-0157262 filed on November 7, 2024, 10-2024-0175138 filed on November 29, 2024, 10-2025-0001746 filed on January 6, 2025, and 10-2025-0010162 filed on January 23, 2025, and all the contents disclosed in the documents of the Korean patent applications are included as part of this specification.

[0002] The present invention relates to a high-purity organic acid prepolymer composition, an organic acid polymer, and a method for producing the same.

Background Art

[0003] Organic acids are commercially important chemicals having various uses in the food, cosmetic, pharmaceutical, and polymer industries. Representative organic acids include lactic acid, 3-hydroxypropionic acid (3-HP), etc. Among them, 3-hydroxypropionic acid (3HP) is a substance that can be utilized as a raw material for the production of acrylic acid, 1,3-propanediol, acrylamide, malonic acid, and polyimide polymers.

[0004] The production of organic acids is mainly carried out by two methods: chemical methods and biological methods. In the case of chemical methods, it has been pointed out that they are not environmentally friendly due to the high cost of starting materials and the generation of toxic substances during the production process, and bio-processes that are environmentally friendly have attracted attention.

[0005] During the production of organic acids by microbial fermentation, other by-products are also generated in addition to organic acids such as 3-hydroxypropionic acid. Therefore, purification processes such as electrodialysis and ion exchange resins are necessary to extract and separate the organic acids from the fermentation liquid. However, these purification processes are lengthy and costly. Currently, there is a need for a method to efficiently convert raw materials such as biopolymers into low-purity organic acids containing by-products. [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] The present invention relates to a method for efficiently and at low process cost producing high-purity and high-molecular-weight oligomers, prepolymers, and polymers using a low-purity organic acid composition containing an inorganic compound. [Means for solving the problem]

[0007] This specification provides a method for producing an organic acid prepolymer, comprising the steps of polymerizing an organic acid composition containing an inorganic compound to produce an oligomer and / or prepolymer, and washing the oligomer and / or prepolymer with a washing solution.

[0008] Furthermore, this specification provides a method for producing an organic acid polymer, comprising the steps of: polymerizing an organic acid composition containing an inorganic compound to produce an oligomer and / or prepolymer; washing the oligomer and / or prepolymer with a washing solution; and polymerizing the washed oligomer and / or prepolymer to produce a polymer.

[0009] Furthermore, this specification provides an organic acid prepolymer in which an organic acid composition containing an inorganic compound is polymerized, wherein the inorganic compound is removed by washing.

[0010] Furthermore, this specification provides organic acid polymers obtained by polymerizing the organic acid prepolymer composition.

[0011] The following describes in more detail an organic acid prepolymer composition, an organic acid polymer, and a method for producing the same according to specific embodiments of the invention.

[0012] The terms used herein are used solely to describe exemplary embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as “includes,” “equip,” or “have” are intended to specify the existence of implemented features, figures, stages, components, or combinations thereof, and should be understood not to preemptively exclude the possibility of the existence or addition of one or more other features, figures, stages, components, or combinations thereof.

[0013] While the present invention can take on various forms through numerous modifications, specific embodiments are described in detail below. However, it should be understood that this is not intended to limit the present invention to any particular disclosure, but rather to include all modifications, equivalents, or substitutions that fall within the aforementioned concept and technical scope.

[0014] Furthermore, unless explicitly stated or otherwise specifically mentioned, the steps constituting a manufacturing method described herein are not construed as being limited to the order in which one step and another steps constituting a single manufacturing method are described in the specification. Therefore, the order of the steps constituting a manufacturing method can be changed to the extent that is easily understood by those skilled in the art, and in this case, the resulting changes that are obvious to those skilled in the art are included within the scope of the present invention.

[0015] In this specification, an organic acid means an organic compound that exhibits acidity, and may be an organic compound containing, for example, a carboxyl group or a sulfone group.

[0016] In this specification, alkali metals may mean all alkali metals and alkaline earth metals.

[0017] According to one embodiment of the invention, a method for producing an organic acid prepolymer is provided, comprising the steps of polymerizing an organic acid composition containing an inorganic compound to produce an oligomer and / or prepolymer, and washing the oligomer and / or prepolymer with a washing solution.

[0018] Conventionally, in order to produce biodegradable, high-value-added organic acid oligomers, prepolymers, and polymers, an organic acid fermentation liquid was produced by microbial fermentation, and the high-purity organic acid used as a reaction raw material was recovered by purifying this liquid. However, in order to recover high-purity organic acid, additional purification steps for the fermentation liquid, such as electrodialysis and ion exchange resin processes, were required, which complicated the process and resulted in high operating costs.

[0019] Therefore, the inventors studied a process for producing high-purity organic acid oligomers, prepolymers, and polymers without purifying the microbial fermentation liquid using complex or costly purification processes such as electrodialysis or ion exchange resin processes. They confirmed that by polymerizing an organic acid composition containing an inorganic compound to produce oligomers and / or prepolymers, and then washing the oligomers and / or prepolymers, it is possible to produce high-purity and biodegradable organic acid oligomers, prepolymers, and polymers, similar to conventional processes for polymerizing high-purity organic acids, while also enabling the production of polymers with high molecular weights. Thus, the inventors completed the invention.

[0020] The inorganic compound-containing organic acid composition can be recovered from a fermentation liquid obtained by fermenting a bacterial strain capable of producing organic acids. However, the inorganic compound-containing organic acid composition may contain a large amount of inorganic impurities such as inorganic compounds without undergoing an additional inorganic purification process. For example, the purity of the organic acid in the inorganic compound-containing organic acid composition may be 90% or less, 88% or less, 85% or less, 83% or less, 80% or less, 75% or less, 70% or less, 65% or less, 50% or less, or 5% to 40%.

[0021] The organic acid is not particularly limited as long as it can be produced from the fermentation of microorganisms. For example, it may be one or more selected from the group consisting of lactic acid, 3-hydroxypropionic acid, butyric acid, acetic acid, propionic acid, succinic acid, and salts thereof. Alternatively, it may be lactic acid or 3-hydroxypropionic acid in order to produce high added-value oligomers, prepolymers, polymers, and the like.

[0022] The method for producing an organic acid prepolymer according to the above-described embodiment may further include a step of fermenting a strain having an organic acid-producing ability to produce an organic acid fermentation broth before the step of polymerizing the inorganic compound-containing organic acid composition to produce an oligomer and / or a prepolymer.

[0023] Microorganisms such as strains having an organic acid-producing ability can produce an organic acid fermentation broth by fermenting low molecular weight sugars. Such microorganisms may be natural microorganisms or genetically engineered microorganisms. The microorganisms may be, for example, bacteria such as cellulolytic bacteria, fungi such as yeast, plants, or protists such as algae, protozoa, or fungus-like protists such as slime molds. Alternatively, a mixture of organisms may be used if the organisms do not cause a rejection reaction.

[0024] For example, a strain having the ability to produce 3-hydroxypropionic acid may contain one or more selected from the group consisting of glycerol dehydratase and aldehyde dehydrogenase, or a gene encoding the two proteins. In one example, the 3-hydroxypropionic acid-producing strain may additionally contain a gene (gdrAB) encoding glycerol dehydratase reactivating enzyme (GdrAB). In one example, the 3-hydroxypropionic acid-producing strain may additionally be a strain capable of biosynthesizing vitamin B 12

[0025] ​The glycerol dehydratase may, but is not limited to, be encoded by the dhaB (GenBank accession no. U30903.1) gene. The dhaB gene may, but is not limited to, be an enzyme derived from Klebsiella pneumonia. The gene encoding the glycerol dehydratase may include genes encoding dhaB1, dhaB2, and / or dhaB3. The glycerol dehydratase protein and the gene encoding it may contain gene and / or amino acid sequence mutations within the range that maintains enzymatic activity in breaking down glycerol into 3-hydroxypropanal (3-HPA) and water (H2O).

[0026] The gene encoding aldehyde dehydrogenase (ALDH) (aldH) may, for example, be the aldH (GenBank Accession no. U00096.3; EaldH) gene derived from Escherichia coli or E. coli K12 MG1655 cell line, the puuC gene derived from Klebsiella pneumonia, and / or the KGSADH gene derived from Azospirillum brasilense. The aldehyde dehydrogenase protein and the gene encoding it may contain mutations in the gene and / or amino acid sequence within a range that maintains activity for producing 3-hydroxypropionic acid from 3-hydroxypropanal.

[0027] The medium for the production of the fermentation broth can be selected without limitation within the target range for the production of organic acids. In one example, the medium may contain glycerol as a carbon source. In other examples, the medium may be crude glycerol and / or pretreated crude glycerol, but is not limited thereto. In one example, the production medium can additionally contain vitamin B 12 can be additionally included.

[0028] In the step of fermenting the strain having the ability to produce the organic acid to produce an organic acid fermentation broth, the concentration of the organic acid contained in the organic acid fermentation broth may be 1 g / L or more and 200 g / L or less, 10 g / L or more and 150 g / L or less, 30 g / L or more and 130 g / L or less, or 40 g / L or more and 100 g / L or less.

[0029] Also, the fermentation may be neutral fermentation, for example, the pH during fermentation may be maintained within the range of 6.0 or more and 8.0 or less, 6.5 or more and 7.5 or less, or 6.5 or more and 7.5 or less, but is not limited thereto. The pH range can be appropriately adjusted as needed. For the neutral fermentation, the alkali metal salt may be added. The alkali metal salt may contain Mg 2+ , Ca 2+ , or a mixture thereof. Also, the alkali metal salt may be Ca(OH)2 or Mg(OH)2, but is not limited thereto.

[0030] The method for producing an organic acid prepolymer according to the above embodiment can further include a step of mixing the fermentation broth and an organic solvent to precipitate organic acid salt crystals after the step of producing the organic acid fermentation broth.

[0031] To recover organic acid salt crystals from the fermentation liquid, an organic solvent can be added dropwise to the fermentation liquid, or the fermentation liquid can be added dropwise to an organic solvent, followed by mixing the fermentation liquid and the organic solvent to induce particle formation of the organic acid salt crystals and precipitate the organic acid salt. This precipitation may be carried out at temperatures of -10°C to 40°C, -9°C to 35°C, -8°C to 30°C, -7°C to 30°C, -6°C to 25°C, -5°C to 20°C, or 0°C to 15°C.

[0032] The aforementioned organic solvent is not limited to this, but may include, for example, alcohols, water, ethers, ketones, halogenated hydrocarbons, aromatic hydrocarbons, etc.

[0033] The alcohol may be one or more selected from the group consisting of, for example, linear or branched alcohols having 1 to 4 carbon atoms, such as methanol, ethanol, and propanol (e.g., isopropyl alcohol).

[0034] The ether may be ethyl ether, dioxane, tetrahydrobutane, etc., the ketone may be acetone, methyl ethyl ketone, methyl butyl ketone, methyl isobutyl ketone, etc., the halogenated hydrocarbon may be dichloromethane, chloroform, dichloroethane, trichloroethane, tetrachloroethane, dichloroethylene, trichloroethylene, tetrachloroethylene, etc., and the aromatic hydrocarbon may be benzene, toluene, xylene, etc.

[0035] Furthermore, the organic solvent may have a concentration of 10-100% (v / v), 20-100 (v / v), 30-100 (v / v), 40-100 (v / v), 50-100 (v / v), 60-100 (v / v), 70-100 (v / v), 80-100 (v / v), 90-100 (v / v), 95-100 (v / v), or 98-100 (v / v), for example, 99% (v / v).

[0036] The amount of the organic solvent added may be 5 to 10 times, 6 to 9 times, or 7 to 8 times the amount of the fermentation liquid.

[0037] The method for producing an organic acid prepolymer according to the above embodiment may further include the steps of mixing the fermentation liquid and an organic solvent to precipitate organic acid salt crystals, producing a solution in which the organic acid salt crystals are dissolved, and adding acid to control the pH to 5 or less.

[0038] For example, after precipitating the organic acid salt crystals, the organic acid salt crystals can be filtered, a solution can be prepared by dissolving the filtered organic acid salt crystals, and the pH can be controlled to 5 or less by adding acid.

[0039] Furthermore, the step of adding the acid allows for the protonation of the organic acid by titrating the acid to produce a salt. At this time, the acid is not particularly limited as long as it can control the pH of the fermentation liquid to 5 or less, but it may be one selected from the group consisting of sulfuric acid, hydrochloric acid, phosphoric acid, carbonic acid, and nitric acid, for example. The salt produced by the acid titration may be CaSO4(s) or MgSO4(s), but is not limited to these. In addition, by adding the acid to the fermentation liquid, the pH of the fermentation liquid can be controlled to 5.0 or less, 4.0 or less, 3.0 or less, 2.0 or less, 1.0 or less, or 0.5 or less.

[0040] The method for producing the organic acid prepolymer includes the step of polymerizing an organic acid composition containing an inorganic compound to produce an oligomer and / or prepolymer. The organic acid composition containing the inorganic compound may contain inorganic impurities such as inorganic compounds, for example, by using metal salts during fermentation. However, it is not limited to these impurities. For example, the organic acid composition containing the inorganic compound may contain magnesium, calcium, sodium, phosphorus, sulfur, potassium, chlorine, salts or derivatives thereof, or mixtures thereof.

[0041] Furthermore, the inorganic compound-containing organic acid composition may contain one or more elements selected from the group consisting of magnesium, calcium, sodium, phosphorus, sulfur, potassium, and chlorine. The content of the elements relative to 100% by weight of the inorganic compound-containing organic acid composition may be 5.0% by weight or less, for example, 3.0% by weight or less, 2.0% by weight or less, or 1.0% by weight or less.

[0042] For example, the inorganic compound-containing organic acid composition may have a calcium (Ca) concentration of 50 ppm or more, 100 ppm or more, 200 ppm or more, or 300 ppm or more and 3,000 ppm or less.

[0043] Furthermore, the organic acid composition containing the inorganic compound may have a sodium (Na) concentration of 300 ppm or more, 500 ppm or more, 700 ppm or more, 1,000 ppm or more, 1,300 ppm or more, 1,500 ppm or more, or 1,800 ppm or more and 3,000 ppm or less.

[0044] Furthermore, the inorganic compound-containing organic acid composition may have a phosphorus (P) concentration of 1 ppm or more, 5 ppm or more, 8 ppm or more, or 10 ppm or more and 3,000 ppm or less.

[0045] Furthermore, the organic acid composition containing the inorganic compound may have a sulfur (S) concentration of 300 ppm or more, 500 ppm or more, 700 ppm or more, 1,000 ppm or more, 1,300 ppm or more, 1,500 ppm or more, or 1,800 ppm or more and 3,000 ppm or less.

[0046] Furthermore, the inorganic compound-containing organic acid composition may have a potassium (K) concentration of 50 ppm or more, 100 ppm or more, 200 ppm or more, or 300 ppm or more and 3,000 ppm or less.

[0047] Furthermore, the organic acid composition containing the inorganic compound may have a chlorine (Cl) concentration of 300 ppm or more, 500 ppm or more, 700 ppm or more, 1,000 ppm or more, 1,500 ppm or more, 2,000 ppm or more, 2,500 ppm or more, or 3,500 ppm or more and 10,000 ppm or less.

[0048] On the other hand, the elemental concentrations can be measured using ICP-OES (Inductively Coupled Plasma-Optical Emission Spectrometry).

[0049] In the step of polymerizing the inorganic compound-containing organic acid composition to produce an oligomer and / or prepolymer, the polymerization may be carried out at a temperature of 75°C to 200°C, for example, 80°C or higher, 85°C or higher, 90°C or higher, 120°C or higher, 150°C or higher, 200°C or higher, or 180°C or lower, 160°C or lower, 150°C or lower, 130°C or lower, 125°C or lower, 120°C or lower, 115°C or lower, or 110°C or lower. If the polymerization temperature is excessively low, the molecular weight of the oligomer and / or prepolymer may be low, and if the polymerization temperature is excessively high, the polymerization of the organic acid may not proceed easily.

[0050] Furthermore, the polymerization of the inorganic compound-containing organic acid composition may be carried out at a pressure of 1 torr or more and 760 torr or less for a period of 1 to 10 hours, or for example, at a pressure of 1 torr or more, 5 torr or more, 7 torr or more, 10 torr or more, 50 torr or more, 100 torr or more, 200 torr or more, or 300 torr or more and 700 torr or less, 500 torr or less, 300 torr or less, 200 torr or less, 150 torr or less, 100 torr or less, 70 torr or less, or 50 torr or less. The reaction time for polymerization of the inorganic compound-containing organic acid composition can be appropriately considered in light of the molecular weight and yield of the resulting oligomer and prepolymer, and is preferably carried out for 1 to 10 hours, 2 to 8 hours, or 3 to 5 hours.

[0051] Furthermore, the polymerization of the inorganic compound-containing organic acid composition may be carried out without a catalyst, or in the presence of a tin-based catalyst and / or a sulfonic acid-based catalyst. The tin-based catalyst may be dibutyl tin dilaureate (DBTDL), dioctyl tin dilaurate (DOTDL), dibutyl tin diacetate, stannous acetate, or tin caprylate, and the sulfonic acid-based catalyst may be, for example, p-toluenesulfonic acid, m-xylene-4-sulfonic acid, 2-mesitylenesulfonic acid, or p-xylene-2-sulfonic acid. The catalyst can be used in amounts of 0.05 mol% to 0.5 mol%, 0.1 mol% to 0.4 mol%, or 0.2 mol% to 0.4 mol% relative to the organic acid.

[0052] The oligomers and prepolymers produced by the polymerization described above have a weight-average molecular weight of 800 or more, 1,000 or more, 1,300 or more, 1,500 or more, 2,000 or more, 2,500 or more, or 3,000 or more, and may also be 15,000 or less, 10,000 or less, 9,000 or less, 8,000 or less, or 7,000 or less.

[0053] Furthermore, the oligomer and prepolymer may have a number average molecular weight of 700 or more, 800 or more, 900 or more, 1,000 or more, 1,200 or more, 1,500 or more, or 2,000 or more, and may also be 15,000 or less, 10,000 or less, 9,000 or less, 8,000 or less, or 7,000 or less.

[0054] The method for producing an organic acid prepolymer according to the above embodiment may include the step of washing the oligomer and / or prepolymer with a washing solution.

[0055] The washing solution may be water, distilled water, or a solution containing a basic compound, such as aqueous ammonia. The basic compound is not particularly limited as long as it is a basic compound that does not contain metal ions, but examples include quaternary ammonium compounds and amines.

[0056] Examples of the quaternary ammonium compounds include tetramethylammonium hydroxide (TMAH), trimethyl-2-hydroxyethylammonium hydroxide (choline), tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, trimethylphenylammonium hydroxide, and benzyltrimethylammonium hydroxide.

[0057] The amine may be a primary aliphatic amine, a secondary aliphatic amine, a tertiary aliphatic amine, or an alicyclic amine. For example, the primary aliphatic amine may be monoethanolamine, ethylenediamine, 2-(2-aminoethoxyethanol), 2-(2-aminoethylamino)ethanol, diethylenetriamine, triethylenetetramine, etc. The secondary aliphatic amine may be diethanolamine, N-methylaminoethanol, N-hydroxyethylaminoethanol, dipropylamine, 2-ethylaminoethanol, etc. The tertiary aliphatic amine may be triethanolamine, dimethylaminoethanol, ethyldiethanolamine, etc. The alicyclic amine may be cyclopentylamine, cyclohexylamine, etc.

[0058] The amount of basic compounds contained in the cleaning solution may be 1% by weight or more, 3% by weight or more, 5% by weight or more, 7% by weight or more, 8% by weight or more, 10% by weight or more, or 30% by weight or less, 25% by weight or less, 20% by weight or less, 15% by weight or less, or 10% by weight or less, based on 100% by weight of the total cleaning solution.

[0059] When washing the oligomer and / or prepolymer with the washing solution, the washing temperature may be 50°C or higher and 95°C or lower. For example, washing can be done at temperatures of 55°C or higher, 60°C or higher, 70°C or higher, or 93°C or lower, 90°C or lower, 85°C or lower, 80°C or lower, and 75°C or lower.

[0060] If the washing temperature is too low, the prepolymer may not dissolve, making washing difficult. If the washing temperature is too high, the oligomer and / or prepolymer may be thermally decomposed.

[0061] When washing the oligomer and / or prepolymer with the washing solution, the washing solution can be used in an amount of 0.5 to 30 times the weight of the oligomer and / or prepolymer, for example, in amounts of 0.7 to 1.0 to 2.0 to 3.0 to 4.0 times, and in amounts of 28 to 25 to 23 to 20 times.

[0062] Furthermore, the purity of the oligomer and / or prepolymer washed in the washing process may be 90% or higher, 93% or higher, 95% or higher, 98% or higher, 99% or higher, or 100%.

[0063] The method for producing an organic acid prepolymer according to the above embodiment may further include, after the step of washing the oligomer and / or prepolymer with a washing solution, a step of solid-liquid or liquid-liquid separation of the washed oligomer and / or prepolymer from the washing solution.

[0064] The aforementioned solid-liquid separation step can be performed by filtration or the like, and the washed oligomer and / or prepolymer can be separated from the washing solution using a filtration flask and a vacuum pump or the like.

[0065] Furthermore, unlike the hydrophilic cleaning solution, the molten oligomer and / or prepolymer are hydrophobic or their hydrophilicity decreases, allowing them to be separated from the cleaning solution. Therefore, in the liquid-liquid separation process, the oligomer and / or prepolymer can be recovered by separating the upper and lower layers of liquid using centrifugation.

[0066] Furthermore, the cleaning solution recovered during the separation process can be reused in additional cleaning processes.

[0067] According to another embodiment of the invention, an organic acid prepolymer is provided in which an organic acid composition containing an inorganic compound is polymerized, wherein the inorganic compound is removed by washing.

[0068] In this case, the organic acid prepolymer may be a 3-hydroxypropionic acid prepolymer. Furthermore, the organic acid prepolymer composition may be produced by the method for producing the organic acid prepolymer according to the above embodiment.

[0069] On the other hand, the prepolymer may include oligomers.

[0070] Furthermore, the inorganic compound-containing organic acid composition is as described above in the method for producing an organic acid prepolymer according to the first embodiment, and may be, for example, recovered from a fermentation liquid obtained by fermenting a bacterial strain capable of producing organic acids. Such a fermentation liquid may contain a large amount of inorganic impurities such as inorganic compounds, but the organic acid prepolymer composition can have high purity by removing such inorganic compounds through washing. In addition, in addition to the by-products of the fermentation liquid, catalysts used during polymerization can also be removed by washing, resulting in high purity. For example, the purity of the organic acid prepolymer may be 90% or higher, 93% or higher, 95% or higher, 98% or higher, 99% or higher, or 100%.

[0071] For example, the washed organic acid prepolymer may have a calcium (Ca) concentration of 200 ppm or less, 150 ppm or less, 100 ppm or less, 50 ppm or less, 30 ppm or less, 15 ppm or less, or 1 ppm to 10 ppm.

[0072] Furthermore, the washed organic acid prepolymer may have a sodium (Na) concentration of 1,000 ppm or less, 500 ppm or less, 100 ppm or less, 50 ppm or less, 20 ppm or less, or 1 ppm to 15 ppm.

[0073] Furthermore, the washed organic acid prepolymer may have a phosphorus (P) concentration of 50 ppm or less, 30 ppm or less, 15 ppm or less, or 1 ppm to 10 ppm or less.

[0074] Furthermore, the washed organic acid prepolymer may have a sulfur (S) concentration of 1,000 ppm or less, 500 ppm or less, 300 ppm or less, 200 ppm or less, 100 ppm or less, or 1 ppm to 80 ppm.

[0075] Furthermore, the washed organic acid prepolymer may have a potassium (K) concentration of 200 ppm or less, 100 ppm or less, 50 ppm or less, 30 ppm or less, 15 ppm or less, or 1 ppm to 10 ppm.

[0076] Furthermore, the washed organic acid prepolymer may have a chlorine (Cl) concentration of 1,000 ppm or less, 500 ppm or less, 100 ppm or less, 50 ppm or less, 20 ppm or less, 15 ppm or less, or 1 ppm to 10 ppm.

[0077] On the other hand, the elemental concentrations can be measured using ICP-OES (Inductively Coupled Plasma-Optical Emission Spectrometry).

[0078] Furthermore, the cleaning is carried out as described above in the method for producing an organic acid prepolymer according to the first embodiment.

[0079] The prepolymer has a weight-average molecular weight of 800 or more, 1,000 or more, 1,300 or more, 1,500 or more, 2,000 or more, 2,500 or more, or 3,000 or more, and may be 15,000 or less, 10,000 or less, 9,000 or less, 8,000 or less, or 7,000 or less, and a number-average molecular weight of 700 or more, 800 or more, 900 or more, 1,000 or more, 1,200 or more, 1,500 or more, or 2,000 or more, and may be 15,000 or less, 10,000 or less, 9,000 or less, 8,000 or less, or 7,000 or less.

[0080] A method for producing an organic acid polymer is provided, further comprising the steps of: polymerizing an organic acid composition containing an inorganic compound to produce an oligomer and / or prepolymer; washing the oligomer and / or prepolymer with a washing solution; and polymerizing the washed oligomer and / or prepolymer to produce a polymer.

[0081] The steps of polymerizing the inorganic compound-containing organic acid composition to produce an oligomer and / or prepolymer, and washing the oligomer and / or prepolymer with a washing solution, are as described above in the method for producing an organic acid prepolymer according to one embodiment.

[0082] In the step of polymerizing the washed oligomer and / or prepolymer to produce a polymer, the polymerization may be carried out at a temperature of 90°C to 200°C and a pressure of 0.01 torr to 760 torr for 20 hours to 100 hours. For example, the reaction temperature for the polymerization may be 95°C to 180°C, 100°C to 150°C, or 105°C to 115°C. Furthermore, the polymerization pressure may be 700 torr or less, 500 torr or less, 300 torr or less, 200 torr or less, 100 torr or less, 50 torr or less, 40 torr or less, or 30 torr or less, and may be 0.01 torr or more, 0.02 torr or more, 0.03 torr or more, 0.04 torr or more, 0.05 torr or more, 0.06 torr or more, 0.07 torr or more, 0.08 torr or more, 0.09 torr or more, or 0.10 torr or more. The polymerization reaction time can be appropriately considered in light of the molecular weight and yield of the polymer produced, and is preferably carried out for 20 to 90 hours, 40 to 80 hours, or 50 to 70 hours.

[0083] Furthermore, the polymerization may be carried out in the presence of a tin-based catalyst and / or a sulfonic acid-based catalyst. The tin-based catalyst may be dibutyl tin dilaureate (DBTDL), dioctyl tin dilaurate (DOTDL), dibutyl tin diacetate, stannous acetate, or tin caprylate, and the sulfonic acid-based catalyst may be, for example, p-toluenesulfonic acid, m-xylene-4-sulfonic acid, 2-mesitylenesulfonic acid, or p-xylene-2-sulfonic acid. The catalyst can be used in amounts of 0.05 mol% to 0.5 mol%, 0.1 mol% to 0.4 mol%, or 0.2 mol% to 0.4 mol% relative to the organic acid and / or prepolymer.

[0084] According to yet another embodiment of the invention, the organic acid prepolymer composition is polymerized to provide an organic acid polymer.

[0085] The organic acid polymer may also be a 3-hydroxypropionic acid polymer.

[0086] Furthermore, the organic acid prepolymer composition may be produced by the method for producing an organic acid prepolymer according to the above embodiment.

[0087] The organic acid polymer may have a weight-average molecular weight of 10,000 or more, 11,000 or more, 15,000 or more, 17,000 or more, 20,000 or more, 21,000 or more, 40,000 or less, 39,000 or less, 38,000 or less, 37,000 or less, 36,000 or less, or 35,000 or less.

[0088] Furthermore, the organic acid polymer may have a number average molecular weight of 7,000 or more, for example, 7,100 or more, 7,200 or more, 7,300 or more, 7,400 or more, 8,000 or more, 8,500 or more, 9,000 or more, 9,500 or more, or 23,000 or less, 22,000 or less, 21,000 or less, 20,000 or less, or 19,000 or less. [Effects of the Invention]

[0089] According to the present invention, a method can be provided for efficiently and at low process costs to produce high-purity and high-molecular-weight oligomers, prepolymers, and polymers using a low-purity organic acid composition containing an inorganic compound. [Modes for carrying out the invention]

[0090] The embodiments of the present invention will be described in more detail below with reference to the following examples. However, the following examples are merely illustrative of embodiments of the present invention, and the content of the present invention is not limited to the following examples.

[0091] Preparation Example 1: Production of 3-hydroxypropionic acid Recombinant vectors were prepared by introducing genes encoding glycerol dehydratase and aldehyde dehydrogenase, which are known to produce 3-hydroxypropionic acid (3HP) using glycerol as a substrate. The prepared recombinant vectors were introduced into the E. coli W3110 strain to create a 3-hydroxypropionic acid-producing strain.

[0092] More specifically, a 3-hydroxypropionic acid-producing strain was created by cloning the BtuR gene encoding adenosyltransferase into a plasmid pCDF containing the genes encoding glycerol dehydratase (dhaB), aldehyde dehydrogenase (aldH), and glycerol dehydratase reactivase (gdrAB), and then introducing the resulting pCDF_J23101_dhaB_gdrAB_J23100_aldH_btuR vector into the W3110 strain (KCCM40219) using electroporation with an electroporation device (Bio-Rad, Gene Pulser Xcell). The process for creating the 3-hydroxypropionic acid-producing strain in this Preparation Example 1, as well as the vector, primers, and enzymes used, were carried out with reference to Example 1 of Published Korean Patent No. 10-2020-0051375.

[0093] The prepared 3-hydroxypropionic acid production strain was fermented in a 5L fermenter at 35°C using unpurified glycerol as a carbon source to produce 3-hydroxypropionic acid. To prevent a decrease in pH due to the production of 3-hydroxypropionic acid, calcium hydroxide (Ca(OH)2), an alkali metal salt, was added to maintain a neutral pH during fermentation.

[0094] After fermentation culture, cells were removed by centrifugation, and organic impurities were purified to prepare a 3-hydroxypropionic acid solution (concentration 5-30 g / L).

[0095] Example 1 (1) Manufacturing of prepolymers 500 g (11.7% content) of the 3-hydroxypropionic acid solution prepared in Preparation Example 1 was placed in a 1000 ml glass reactor, and a concentrated aqueous solution of 3-hydroxypropionic acid (72% content) was produced by vacuum distillation at a temperature of 40-50°C. During concentration, solid precipitates were filtered and removed additionally. 80 g of the aqueous solution of 3-hydroxypropionic acid and 0.5 g of p-toluenesulfonic acid (p-TSA) catalyst were placed in an oil bath, and a polymerization reaction was carried out at a temperature of 90°C and a pressure of 70 torr for 2 hours to produce a 3-hydroxypropionic acid prepolymer.

[0096] (2) Cleaning of prepolymer The 3-hydroxypropionic acid prepolymer was washed with water at a temperature of 85°C using a washing solution. The washing solution was used at a rate of three times the weight of the 3-hydroxypropionic acid prepolymer. Subsequently, the washed prepolymer and washing solution were separated using a filtration flask and a vacuum pump to recover the washed prepolymer. The recovered prepolymer was then dried in an oven at 40°C for 20 hours to obtain the final dried prepolymer.

[0097] (3) Production of polymers 30 g of the prepolymer and 0.25 g of p-toluenesulfonic acid (p-TSA) catalyst were placed in an oil bath, and polymerization was carried out at a temperature of 95°C and a pressure of 1 torr for 72 hours to produce a polymer, i.e., poly(3-hydroxypropionate).

[0098] Example 2 (1) Manufacturing of prepolymers 500 g (11.7% content) of the 3-hydroxypropionic acid solution prepared in Preparation Example 1 was placed in a 1000 ml glass reactor, and a concentrated aqueous solution of 3-hydroxypropionic acid (72% content) was produced by vacuum distillation at a temperature of 40-50°C. 80 g of the aqueous solution of 3-hydroxypropionic acid and 0.5 g of p-toluenesulfonic acid (p-TSA) catalyst were placed in an oil bath, and a polymerization reaction was carried out at a temperature of 90°C and a pressure of 70 torr for 2 hours to produce a 3-hydroxypropionic acid prepolymer.

[0099] (2) Cleaning of prepolymer A washing solution was prepared by mixing 500 ml of water and 5 ml of aqueous ammonia, and the 3-hydroxypropionic acid prepolymer was washed with the washing solution at a temperature of 85°C. At this time, the washing solution was used at a weight of 1:1 relative to the 3-hydroxypropionic acid prepolymer. Subsequently, the washed prepolymer and the washing solution were separated using a filtration flask and a vacuum pump, and the washed prepolymer was recovered.

[0100] (3) Production of polymers 30 g of the prepolymer and 0.25 g of p-toluenesulfonic acid (p-TSA) catalyst were placed in an oil bath, and polymerization was carried out at a temperature of 90°C and a pressure of 1 torr for 30 hours to produce a polymer, i.e., poly(3-hydroxypropionate).

[0101] Example 3 (1) Manufacturing of prepolymers 500 g (11.7% content) of the 3-hydroxypropionic acid solution prepared in Preparation Example 1 was placed in a 1000 ml glass reactor, and a concentrated aqueous solution of 3-hydroxypropionic acid (72% content) was produced by vacuum distillation at a temperature of 40-50°C. 80 g of the aqueous solution of 3-hydroxypropionic acid and 0.5 g of p-toluenesulfonic acid (p-TSA) catalyst were placed in an oil bath, and a polymerization reaction was carried out at a temperature of 90°C and a pressure of 70 torr for 2 hours to produce a 3-hydroxypropionic acid prepolymer.

[0102] (2) Cleaning of prepolymer The 3-hydroxypropionic acid prepolymer was washed twice with distilled water at a temperature of 85°C. The washing solution was used in an amount twice the weight of the 3-hydroxypropionic acid prepolymer. Subsequently, the washed prepolymer and washing solution were separated using a filtration flask and a vacuum pump, and the washed prepolymer was recovered.

[0103] (3) Production of polymers 30 g of the prepolymer and 0.25 g of p-toluenesulfonic acid (p-TSA) catalyst were placed in an oil bath, and polymerization was carried out at a temperature of 90°C and a pressure of 1 torr for 30 hours to produce a polymer, i.e., poly(3-hydroxypropionate).

[0104] Comparative Example 1 The prepolymer and polymer were manufactured in the same manner as in Example 1, except that the prepolymer cleaning step (2) was not carried out.

[0105] Reference Example 1 (1) Purification of 3-hydroxypropionic acid Inorganic impurities remaining in the 3-hydroxypropionic acid solution produced in Preparation Example 1 were purified by electrodialysis using an electrodialysis apparatus from Innomedetech. Specifically, the electrodialysis cell of the electrodialysis apparatus used an Innomedetech L3 membrane as the cation and anion separation membrane, and the process was carried out for 40 minutes using a constant voltage method (20V, 1V per cell) with 20 cells. During this time, electrodialysis was performed until the electrical conductivity of the demineralization cell decreased to 10% compared to the initial conductivity of 100%, and 3-hydroxypropionic acid was recovered.

[0106] (2) Manufacturing of prepolymers 600 g (10% content) of the 3-hydroxypropionic acid solution produced in Production Example 1 was placed in a 1000 ml glass reactor, and concentrated 3-hydroxypropionic acid (72% content) was produced by vacuum distillation at a temperature of 40-50°C. 3-hydroxypropionic acid prepolymer was produced by adding an aqueous solution of 3-hydroxypropionic acid (72%) and 0.5 g of p-toluenesulfonic acid (p-TSA) catalyst to an oil bath and polymerizing it at a temperature of 90°C and a pressure of 70 torr for 2 hours.

[0107] (3) Production of polymers Without any separate transfer, the aforementioned prepolymer was polymerized in an oil bath at a pressure of 1 torr for 21 hours by raising the temperature to 90°C. This process produced a polymer, i.e., poly(3-hydroxypropionate).

[0108] evaluation 1. Molecular weight evaluation using GPC (gel permeation chromatography) For each prepolymer and polymer produced in the above examples and comparative examples, the molecular weight was evaluated using a Water e2695 model apparatus and Agilent Plgel mixed c and b columns. 20 ul of sample was injected into a 4 mg / ml chloroform solvent. The weight-average molecular weight (Mw), number-average molecular weight (Mn), and polydispersity index (PDI) were measured using gel permeation chromatography (GPC, Tosoh ECO SEC Elite), and the results are shown in Table 1 below. If the molecular weight of the prepolymer was not measured, it is indicated as "-" in Table 1. Solvent: chloroform (eluent) Flow rate: 1.0ml / min Column temperature: 40℃ Standard: Polystyrene (corrected with a cubic function)

[0109] 2. Measurement of elemental content The elemental concentrations in the prepolymers produced in Example 1 and Comparative Example 1 were measured using ICP-OES (Inductively Coupled Plasma-Optical Emission Spectrometry), and the results are shown in Table 1 below.

[0110] Specifically, the pretreatment was carried out by Prep. Acid Digestion. After accurately weighing approximately 0.05 g of the sample into a corning tube, 0.5 mL of nitric acid was added to the sample, and then the sample was dissolved by shaking overnight at room temperature. To accelerate the reaction of the sample, a small amount of hydrogen peroxide was added to dissolve the sample. If the sample was completely dissolved cleanly, it was diluted with triple-distilled water to 10 mL to prepare an analytical sample. After removing the undissolved components with a 0.45 μm PTFE filter, the remaining filtrate was introduced into an ICP-OES apparatus (AVIO500, Perkin Elmer) for component analysis. On the other hand, when the element concentration was not measured, it was indicated as "-" in Table 1.

[0111] <ICP-OES Analysis Conditions> RF Power: 1300 W Torch Height: 15 mm Plasma Gas Flow Rate: 15 L / min Sample Gas Flow Rate: 0.8 L / min Auxiliary Gas Flow Rate: 0.20 L / min Pump Speed: 1.5 ml / min

[0112]

Table 1

[0113] Referring to Table 1 above, Example 1, in which a washing process was performed after polymerization with a prepolymer, showed a low concentration of elements such as inorganic elements, confirming that a large amount of inorganic impurities such as inorganic compounds were removed from the starting material, the "organic acid composition containing inorganic compounds," by the washing process. In contrast, the prepolymer of Comparative Example 1, in which no washing was performed, contained a large amount of elements such as inorganic elements, confirming that inorganic impurities such as inorganic compounds from the starting material, the "organic acid composition containing inorganic compounds," were still present in the prepolymer. Furthermore, it was confirmed that Examples 1 to 3, in which polymers were produced by polymerizing washed prepolymers, had higher number-average molecular weight and weight-average molecular weight compared to Comparative Example 1, in which polymers were produced by polymerizing unwashed prepolymers. In addition, it was confirmed that Examples 1 to 3 had polymer molecular weights similar to Reference Example 1, in which the organic acid was purified using an electrodialysis apparatus.

Claims

1. A step of polymerizing an organic acid composition containing an inorganic compound to produce an oligomer and / or prepolymer, The step of washing the oligomer and / or prepolymer with a washing solution is included. A method for producing organic acid prepolymers.

2. The method for producing an organic acid prepolymer according to claim 1, wherein the organic acid is one or more selected from the group consisting of lactic acid, 3-hydroxypropionic acid, butyric acid, acetic acid, propionic acid, succinic acid, and salts thereof.

3. A method for producing an organic acid prepolymer according to claim 1, wherein the purity of the organic acid in the inorganic compound-containing organic acid composition is 90% or less.

4. The method for producing an organic acid prepolymer according to claim 1, wherein the inorganic compound-containing organic acid composition comprises magnesium, calcium, sodium, phosphorus, sulfur, potassium, chlorine, salts thereof, derivatives thereof, or mixtures thereof.

5. The method for producing an organic acid prepolymer according to claim 1, wherein the oligomer and the prepolymer each independently have a weight-average molecular weight of 800 or more and 15,000 or less.

6. The method for producing an organic acid prepolymer according to claim 1, wherein the inorganic compound-containing organic acid composition is recovered from a fermentation liquid obtained by fermenting a bacterial strain having the ability to produce organic acids.

7. Before the step of polymerizing the inorganic compound-containing organic acid composition to produce an oligomer and / or prepolymer, A method for producing an organic acid prepolymer according to claim 1, further comprising the step of fermenting a bacterial strain having the ability to produce organic acids to produce an organic acid fermentation liquid.

8. A method for producing an organic acid prepolymer according to claim 7, further comprising the step of mixing the fermentation liquid with an organic solvent to precipitate organic acid salt crystals.

9. The method for producing an organic acid prepolymer according to claim 8, further comprising the step of preparing a solution in which the organic acid salt crystals are dissolved, and then adding an acid to control the pH to 5 or less.

10. The method for producing an organic acid prepolymer according to claim 1, wherein the washing solution is a solution containing water or a basic compound.

11. The method for producing an organic acid prepolymer according to claim 1, wherein the washing is performed at a temperature of 50°C to 300°C.

12. After the step of washing the oligomer and / or prepolymer with a washing solution, A method for producing an organic acid prepolymer according to claim 1, further comprising the step of separating the washed oligomer and / or prepolymer from the washing solution in a solid-liquid or liquid-liquid manner.

13. A step of polymerizing an organic acid composition containing an inorganic compound to produce an oligomer and / or prepolymer, The steps include washing the oligomer and / or prepolymer with a washing solution, The step of polymerizing the washed oligomer and / or prepolymer to produce a polymer is included, A method for producing organic acid polymers.

14. The method for producing an organic acid polymer according to claim 13, wherein the polymer has a number average molecular weight of 7,000 or more.

15. The method for producing an organic acid polymer according to claim 13, wherein the polymer has a weight-average molecular weight of 10,000 or more.

16. The organic acid prepolymer is obtained by polymerizing an organic acid composition containing an inorganic compound. The inorganic compound is an organic acid prepolymer composition removed by washing.

17. The organic acid prepolymer composition according to claim 16, wherein the organic acid prepolymer is a 3-hydroxypropionic acid prepolymer.

18. An organic acid polymer obtained by polymerizing the organic acid prepolymer composition described in claim 16.

19. The organic acid polymer according to claim 18, wherein the organic acid polymer is a 3-hydroxypropionic acid polymer.

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