KR20240041702A - Preparation method of alkyl 3-hydroxypropionate and alkyl lactate - Google Patents

Abstract

The present invention provides a method for preparing alkyl 3-hydroxypropionate and alkyl lactate from hydroxyalkanoate-lactide copolymer.

Description

Method for producing alkyl 3-hydroxypropionate and alkyl lactate {PREPARATION METHOD OF ALKYL 3-HYDROXYPROPIONATE AND ALKYL LACTATE}

The present invention relates to a process for preparing alkyl 3-hydroxypropionates and alkyl lactates.

Plastics are inexpensive and durable materials that can be used to produce a variety of products that find use in a wide range of applications. Accordingly, the production of plastics has been increasing dramatically over the past few decades. Moreover, more than 50% of these plastics are used in single-use, disposable or short-lived products that are discarded within one year of manufacture, such as packaging, agricultural films, single-use consumer goods, etc. Additionally, due to the durability of polymers, significant amounts of plastic end up in landfills and natural habitats around the world, causing increasing environmental problems. Even biodegradable plastics can last for decades, depending on local environmental factors such as levels of UV exposure, temperature, and the presence of appropriate microorganisms.

Therefore, different solutions are being explored to reduce the economic and environmental impacts associated with the accumulation of plastics, from plastic decomposition to plastic recycling.

As an example, polyethylene terephthalate (PET) is the most closed-loop recycled plastic, where PET waste (mainly bottles) is collected, sorted, and recycled. They are pressed into batches, crushed, washed, cut into flakes, melted and extruded into pellets and offered for sale. However, this plastic recycling method only applies to plastic articles containing only PET, requiring excessive prior sorting.

Additionally, another potential method for recycling plastics is chemical recycling, which allows recovering the chemical components of the polymer. The resulting monomer, after purification, can be used to re-produce plastic articles.

Recently, the demand for recycling of various types of plastics has increased considerably, but there are limitations such as difficult process design and difficulty in securing high purity or selectivity.

The present invention is intended to provide a method that can efficiently provide high purity alkyl 3-hydroxypropionate and alkyl lactate while securing high selectivity from hydroxyalkanoate-lactide copolymer.

According to one embodiment of the present invention, it includes reacting a hydroxyalkanoate-lactide copolymer with an alcohol in the presence of a catalyst, wherein the catalyst is an alkyl 3-hydroxypropyl polymer comprising an acid catalyst or a metal salt. Methods for preparing cypionates and alkyl lactates are provided.

Hereinafter, the method for producing alkyl 3-hydroxypropionate and alkyl lactate according to specific embodiments of the invention will be described in more detail.

Throughout this specification, unless otherwise specified, “include” or “contains” refers to the inclusion of a certain component (or component) without particular limitation, excluding the addition of other components (or components). cannot be interpreted as

In addition, unless it is specified that the steps constituting the manufacturing method described in this specification are sequential or continuous, or there is another special class, one step and other steps constituting one manufacturing method are performed in the order described in the specification. It is not interpreted as limited. Accordingly, the order of the structural steps of the manufacturing method can be changed within a range that can be easily understood by a person skilled in the art, and in this case, changes that are obvious to those skilled in the art are included in the scope of the present invention.

Additionally, unless otherwise stated herein, the weight average molecular weight can be measured using gel permeation chromatography (GPC). Specifically, the prepolymer or copolymer is dissolved in chloroform to a concentration of 2 mg/ml, then 20 μl is injected into GPC, and GPC analysis is performed at 40°C. At this time, the mobile phase of GPC uses chloroform and flows at a flow rate of 1.0 mL/min, the column uses two Agilent Mixed-Bs connected in series, and the detector uses an RI Detector. The Mw value is derived using a calibration curve formed using a polystyrene standard specimen. The weight average molecular weights of the polystyrene standard specimens were 2,000 g/mol, 10,000 g/mol, 30,000 g/mol, 70,000 g/mol, 200,000 g/mol, 700,000 g/mol, 2,000,000 g/mol, 4,000,000 g/mol, and 10,000,000. Nine types of g/mol were used.

Throughout this specification, “polylactic acid prepolymer” refers to polylactic acid with a weight average molecular weight of 1,000 to 50,000 g/mol, which is obtained by oligomerizing lactic acid.

Throughout this specification, “poly(3-hydroxypropionate) prepolymer” refers to poly(3-hydroxypropionate) with a weight average molecular weight of 1,000 to 50,000 g/mol obtained by oligomerizing 3-hydroxypropionate. it means.

Additionally, unless otherwise stated herein, the weight average molecular weight of polylactic acid prepolymer, poly(3-hydroxypropionate) prepolymer, and copolymer can be measured using gel permeation chromatography (GPC). Specifically, the prepolymer or copolymer is dissolved in chloroform to a concentration of 2 mg/ml, then 20 μl is injected into GPC, and GPC analysis is performed at 40°C. At this time, the mobile phase of GPC uses chloroform and flows at a flow rate of 1.0 mL/min, the column uses two Agilent Mixed-Bs connected in series, and the detector uses an RI Detector. The Mw value is derived using a calibration curve formed using a polystyrene standard specimen. The weight average molecular weights of the polystyrene standard specimens were 2,000 g/mol, 10,000 g/mol, 30,000 g/mol, 70,000 g/mol, 200,000 g/mol, 700,000 g/mol, 2,000,000 g/mol, 4,000,000 g/mol, and 10,000,000. Nine types of g/mol were used.

According to one embodiment of the invention, it includes reacting the hydroxyalkanoate-lactide copolymer with an alcohol in the presence of a catalyst, wherein the catalyst is an alkyl 3-hydroxypropyl acid catalyst or a metal salt. Methods for preparing cypionates and alkyl lactates are provided.

The present inventors reacted the hydroxyalkanoate-lactide copolymer with alcohol in the presence of a catalyst to produce alkyl 3-hydroxypropionate and alkyl lactate, which are recyclable monomers for bioacrylonitrile synthesis, etc., with high purity and The present invention was completed by finding that it can be recovered at high yield.

As the hydroxyalkanoate-lactide copolymer reacts with alcohol in the presence of a catalyst, the hydroxyalkanoate-lactide copolymer undergoes alcohol decomposition (alcoholysis), and the alcohol decomposition produces a recyclable monomer. It is environmentally friendly and economical, and the alkyl 3-hydroxypropionate and alkyl lactate can be recycled into bioacrylonitrile.

In the method for producing alkyl 3-hydroxypropionate and alkyl lactate according to the above embodiment, the hydroxyalkanoate-lactide copolymer is reacted with alcohol in the presence of a catalyst, thereby producing hydroxyalkanoate- Lactide copolymers may undergo alcohololysis.

In the step of reacting the hydroxyalkanoate-lactide copolymer with alcohol in the presence of the catalyst, the alcohol is contained in an amount of 110 parts by weight or more and 1000 parts by weight or less based on 100 parts by weight of the hydroxyalkanoate-lactide copolymer. may be included.

Specifically, in the step of reacting the hydroxyalkanoate-lactide copolymer with alcohol in the presence of the catalyst, the alcohol is used in an amount of 110 parts by weight or more, 200 parts by weight, based on 100 parts by weight of the hydroxyalkanoate-lactide copolymer. Parts by weight or more, 300 parts by weight or more, 500 parts by weight or less, 1000 parts by weight or less, 900 parts by weight or less, 800 parts by weight or less, 110 parts by weight or more, 1000 parts by weight or less, 200 parts by weight or more, 1000 parts by weight or less, 300 parts by weight More than 1000 parts by weight or less, 500 parts by weight or more but less than 1000 parts by weight, 110 parts by weight or more but less than 900 parts by weight, 200 parts by weight or more but less than 900 parts by weight, 300 parts by weight or more and less than 900 parts by weight, more than 500 parts by weight but less than 900 parts by weight , 110 parts by weight or more and 800 parts by weight or less, 200 parts by weight or more and 800 parts by weight or less, 300 parts by weight or more and 800 parts by weight or less, and 500 parts by weight or more and 800 parts by weight or less.

The most economically final alkyl 3-hydroxypropionate and alkyl lactate are produced as the alcohol is contained in an amount of 110 to 1000 parts by weight based on 100 parts by weight of the hydroxyalkanoate-lactide copolymer. Conversion rate can be improved.

If the alcohol is included in less than 110 parts by weight based on 100 parts by weight of the hydroxyalkanoate-lactide copolymer, the hydroxyalkanoate-lactide copolymer is not dissolved or only a small amount is dissolved, resulting in an extremely long reaction time. Otherwise, the conversion rate of the final produced alkyl 3-hydroxypropionate and alkyl lactate may be reduced. In addition, if the alcohol is included in excess of 1000 parts by weight based on 100 parts by weight of the hydroxyalkanoate-lactide copolymer, additional energy and time are required to recover the alcohol after the reaction proceeds, which leads to a problem of lower economic feasibility. You can.

The type of alcohol is not greatly limited, but may be a monohydric alcohol in which one hydroxy group is bonded to an alkyl group having 1 to 20 carbon atoms.

Specifically, the alcohol may include one or more alcohols selected from the group consisting of methanol, ethanol, and butanol. Depending on the type of alcohol, the alkyl group of the final produced alkyl 3-hydroxypropionate and alkyl lactate can be adjusted.

For example, when methanol is used as the alcohol, in the method for producing alkyl 3-hydroxypropionate and alkyl lactate according to the above embodiment, the hydroxyalkanoate-lactide copolymer is mixed with alcohol in the presence of a catalyst. By reaction, methyl 3-hydroxypropionate and methyl lactate can be produced.

In one embodiment, the final alkyl 3-hydroxypropionate may include alkyl 3-hydroxypropionate represented by the following formula (1).

[Formula 1]

In Formula 1, R ₁ is an alkyl group having 1 to 20 carbon atoms.

Specifically, as described above, the alkyl group, that is, R ₁ , of the finally produced alkyl 3-hydroxypropionate can be adjusted depending on the type of alcohol.

For example, when methanol is used as the alcohol, methyl 3-hydroxypropionate (Methyl 3-hydroxypropionate) in Formula 1 where R ₁ is a methyl group can be produced.

In one embodiment, the alkyl lactate that is finally produced may include an alkyl lactate represented by the following formula (2).

[Formula 2]

In Formula 2, R ₂ is an alkyl group having 1 to 20 carbon atoms.

Specifically, as described above, the alkyl group, that is, R ₂ , of the finally produced alkyl lactate can be adjusted depending on the type of alcohol.

For example, when methanol is used as the alcohol, methyl lactate in Formula 2 where R ₂ is a methyl group can be produced.

Meanwhile, in the step of reacting the hydroxyalkanoate-lactide copolymer with alcohol in the presence of the catalyst, the catalyst is used in an amount of 0.1 parts by weight or more and 10 parts by weight based on 100 parts by weight of the hydroxyalkanoate-lactide copolymer. It may be included below.

Specifically, in the step of reacting the hydroxyalkanoate-lactide copolymer with alcohol in the presence of the catalyst, the catalyst is used in an amount of 0.1 part by weight or more and 0.5 parts by weight based on 100 parts by weight of the hydroxyalkanoate-lactide copolymer. more than 10 parts by weight, less than 5 parts by weight, more than 0.1 parts by weight but less than 10 parts by weight, more than 0.1 parts by weight but less than 5 parts by weight, more than 0.5 parts by weight but less than 10 parts by weight, more than 0.5 parts by weight but less than 5 parts by weight. You can.

The most economically final alkyl 3-hydroxypropionate and alkyl lactate are produced as the catalyst is included in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the hydroxyalkanoate-lactide copolymer. Conversion rate can be improved.

If the catalyst is included in less than 0.1 parts by weight based on 100 parts by weight of the hydroxyalkanoate-lactide copolymer, a problem may occur in which the reaction does not proceed completely. In addition, if the catalyst is included in excess of 10 parts by weight based on 100 parts by weight of the hydroxyalkanoate-lactide copolymer, side reactions may occur, which may result in lower recovery or lower purity.

In the method for producing alkyl 3-hydroxypropionate and alkyl lactate according to the above embodiment, when the catalyst is an acid catalyst, the catalyst may include sulfuric acid.

As the catalyst contains sulfuric acid, it is possible to produce alkyl 3-hydroxypropionate and alkyl lactate economically while realizing a fast reaction rate, and the final produced alkyl 3-hydroxypropionate and alkyl lactate Excellent conversion rates to Tate can be achieved

Alternatively, when the catalyst is a metal salt, the catalyst may include one or more metal salts selected from the group consisting of halogen salts, phosphates, nitrates, sulfates, ammonium salts, acetates, and carbonates of metals.

Additionally, the metal salt may include a metal salt of one or more metals selected from the group consisting of zinc, copper, magnesium, manganese, cobalt, and nickel. Preferably, the metal salt may include a metal salt of one or more metals selected from the group consisting of zinc, copper, magnesium, and manganese. More preferably, the metal salt may include a metal salt of zinc or copper. For example, the metal salt may include a metal salt of zinc.

That is, the metal salt may preferably include an acetate of one or more metals selected from the group consisting of zinc, copper, magnesium, and manganese. More preferably, the metal salt may include acetate of zinc or copper. For example, the metal salt may include acetate of zinc.

As the metal salt contains the above-mentioned compounds, alkyl 3-hydroxypropionate and alkyl lactate can be produced economically while realizing a fast reaction rate, and the final produced alkyl 3-hydroxypropionate and Excellent conversion rates to alkyl lactates can be achieved.

Meanwhile, in the method for producing alkyl 3-hydroxypropionate and alkyl lactate according to the above embodiment, the hydroxyalkanoate-lactide copolymer is one or more polyhydroxyalkanoate (PHA; polyhydrxyalkanoate) ) block and may be a block copolymer containing one or more polylactic acid blocks. As the hydroxyalkanoate-lactide copolymer contains the above-mentioned blocks, it can exhibit the environmental friendliness and biodegradability of polyhydroxyalkanoate and polylactic acid.

The hydroxyalkanoates include 3-hydroxybutyrate, 4-hydroxybutyrate, 2-hydroxypropionate, 3-hydroxypropionate, and (D)-3- having a medium chain length of 6 to 14 carbon atoms. It may be hydroxycarboxylate, 3-hydroxyvalate, 4-hydroxyvalate or 5-hydroxyvalate.

Therefore, the hydroxyalkanoate-lactide copolymer is 3-hydroxybutyrate-lactide copolymer, 4-hydroxybutyrate-lactide copolymer, 2-hydroxypropionate-lactide copolymer, 3- It may be a hydroxypropionate-lactide copolymer, a 4-hydroxyvalate-lactide copolymer, or a 5-hydroxyvalate-lactide copolymer, for example, the hydroxyalkanoate-lactide. The copolymer may be a 3-hydroxypropionate-lactide copolymer to improve flexibility and mechanical properties.

The 3-hydroxypropionate-lactide copolymer may be a block copolymer obtained by polymerizing polylactic acid prepolymer and poly(3-hydroxypropionate) prepolymer. The 3-hydroxypropionate-lactide copolymer exhibits the excellent tensile strength and elastic modulus characteristics of the polylactic acid prepolymer, while the poly(3-hydroxypropionate) prepolymer has a glass transition temperature (Tg). By increasing flexibility by lowering and improving mechanical properties such as impact strength, the brittleness of polylactic acid due to its poor elongation can be prevented.

The polylactic acid prepolymer may be manufactured by fermentation or polycondensation of lactic acid. The polylactic acid prepolymer may have a weight average molecular weight of 1,000 g/mol or more, or 5,000 g/mol or more, or 6,000 g/mol or more, or 8,000 g/mol or more, and 50,000 g/mol or less, or 30,000 g/mol or less, When it is desired to increase the crystallinity of the block containing repeating units derived from polylactic acid prepolymer in the final manufactured block copolymer, the polylactic acid prepolymer must be greater than 20,000 g/mol, or 22,000 g/mol or more, or 23,000 g/mol. It is preferable to have a high weight average molecular weight of more than or equal to 25,000 g/mol, and less than or equal to 50,000 g/mol, or less than or equal to 30,000 g/mol, or less than or equal to 28,000 g/mol, or less than or equal to 26,000 g/mol.

If the weight average molecular weight of the polylactic acid prepolymer is less than 20,000 g/mol, the polymer crystals are small and it is difficult to maintain the crystallinity of the polymer in the final manufactured block copolymer. If the weight average molecular weight of the polylactic acid prepolymer exceeds 50,000 g/mol, it is difficult to maintain the crystallinity of the polymer. During polymerization, the side reaction rate occurring within the prepolymer chain becomes faster than the reaction rate between polylactic acid prepolymers. Meanwhile, 'lactic acid' used in the present invention refers to L-lactic acid, D-lactic acid, or a mixture thereof.

The poly(3-hydroxypropionate) prepolymer may be manufactured by fermenting or condensation polymerization of 3-hydroxypropionate. The weight average molecular weight of the poly(3-hydroxypropionate) prepolymer is 1,000 g/mol or more, or 5,000 g/mol or more, or 8,000 g/mol or more, or 8,500 g/mol or more, and 50,000 g/mol or less, Alternatively, it may be 30,000 g/mol or less, and when it is desired to increase the crystallinity of the repeating unit derived from the poly(3-hydroxypropionate) prepolymer in the final manufactured block copolymer, the poly(3-hydroxypropionate) The prepolymer has a high weight average molecular weight of more than 20,000 g/mol, or more than 22,000 g/mol, or more than 25,000 g/mol, and less than or equal to 50,000 g/mol, or less than or equal to 30,000 g/mol, or less than or equal to 28,000 g/mol. desirable.

As explained in the polylactic acid prepolymer, if the weight average molecular weight of the poly(3-hydroxypropionate) prepolymer is 20,000 g/mol or less, the polymer crystals are small, making it difficult to maintain the crystallinity of the polymer in the final manufactured block copolymer. It is difficult, and if the weight average molecular weight of the poly(3-hydroxypropionate) prepolymer exceeds 50,000 g/mol, the side reaction rate occurring inside the prepolymer chain is higher than the reaction rate between poly(3-hydroxypropionate) prepolymers during polymerization. becomes faster.

That is, at least one of the polylactic acid prepolymer and the poly(3-hydroxypropionate) prepolymer may have a weight average molecular weight of more than 20,000 g/mol and less than or equal to 50,000 g/mol.

The 3-hydroxypropionate-lactide copolymer is a block copolymer in which polylactic acid prepolymer and poly(3-hydroxypropionate) prepolymer are polymerized, and in the block copolymer, the polylactic acid prepolymer and poly(3 -Hydroxypropionate) The weight ratio of the prepolymer is 95:5 to 50:50, 90:10 to 55:45, 90:10 to 60:40, 90:10 to 70:30, or 90:10 to 80:20. It can be. If too little of the poly(3-hydroxypropionate) prepolymer is included in the polylactic acid prepolymer, brittleness may increase, and the poly(3-hydroxypropionate) prepolymer may increase brittleness. If too much prepolymer is included, the molecular weight may be lowered and processability and heat stability may be reduced.

The hydroxyalkanoate-lactide copolymer has a weight average molecular weight (Mw) measured using gel permeation chromatography (GPC) of 50,000 to 300,000 g/mol, and more specifically, 50,000 g/mol. mol or more, 70,000 g/mol or more, or 100,000 g/mol or more, and has a weight average molecular weight of 300,000 g/mol or less, or 200,000 g/mol or less, or 150,000 g/mol or less. If the weight average molecular weight of the hydroxyalkanoate-lactide copolymer is too small, the overall mechanical properties may be significantly reduced, and if the weight average molecular weight is too large, the process may be difficult and processability and elongation may be low.

Meanwhile, the lactic acid and 3-hydroxypropionate may be plastic and biodegradable compounds produced from renewable sources by microbial fermentation, and polylactic acid prepolymer and poly(3-hydroxypropionate) formed by polymerizing them The block copolymer containing the prepolymer can also contain a large amount of bio raw materials while exhibiting environmental friendliness and biodegradability.

In the method for producing alkyl 3-hydroxypropionate and alkyl lactate of one embodiment, the step of reacting the hydroxyalkanoate-lactide copolymer with alcohol in the presence of the catalyst is performed at a temperature of 50°C or more and 100°C or less. It can be performed in

Specifically, in the method for producing alkyl 3-hydroxypropionate and alkyl lactate of one embodiment, the step of reacting the hydroxyalkanoate-lactide copolymer with alcohol in the presence of the catalyst is performed at 50 ° C. or higher and 60 ° C. More than 70℃, more than 80℃, less than 100℃, more than 90℃, more than 50℃ but less than 100℃, more than 60℃ but less than 100℃, more than 70℃ but less than 100℃, more than 80℃ but less than 100℃, more than 50℃ 90 It can be done at ℃ or lower, 60 ℃ or higher and 90 ℃ or lower, 70 ℃ or higher and 90 ℃ or lower, or 80 ℃ or higher and 90 ℃ or lower.

If the step of reacting the hydroxyalkanoate-lactide copolymer with alcohol in the presence of the catalyst is performed below 50° C., the reactivity between the compounds decreases, resulting in the final production of alkyl 3-hydroxypropionate and alkyl lactate. A problem may occur where the conversion rate decreases.

In addition, in the method for producing alkyl 3-hydroxypropionate and alkyl lactate of one embodiment, the step of reacting the hydroxyalkanoate-lactide copolymer with alcohol in the presence of the catalyst is performed for 5 hours or more and 20 hours or less. It can be done.

Specifically, in the method for producing alkyl 3-hydroxypropionate and alkyl lactate of one embodiment, the step of reacting the hydroxyalkanoate-lactide copolymer with alcohol in the presence of the catalyst is performed for 5 hours or more, 6 hours. 1 hour or more, 20 hours or less, 15 hours or less, 10 hours or less, 5 hours or more but 20 hours or less, 5 hours or more but 15 hours or more, 5 hours or more but 10 hours or less, 6 hours but not more than 20 hours, 6 hours but not more than 15 hours, It can be more than 6 hours and less than 10 hours.

If the step of reacting the hydroxyalkanoate-lactide copolymer with alcohol in the presence of the catalyst is performed for less than 5 hours, the reaction does not proceed sufficiently, resulting in the final production of alkyl 3-hydroxypropionate and alkyl lactate. The conversion rate may decrease. Additionally, if the step of reacting the hydroxyalkanoate-lactide copolymer with alcohol in the presence of the catalyst is performed for more than 20 hours, excessively large amounts of by-products may be generated.

In the method for producing alkyl 3-hydroxypropionate and alkyl lactate of one embodiment, reacting the hydroxyalkanoate-lactide copolymer with alcohol in the presence of the catalyst; Adding eight-lactide copolymer and alcohol; adding a catalyst to the reactor; and heating the reactor to a temperature of 50°C or more and 100°C or less and stirring for 5 hours or more and 20 hours or less.

Meanwhile, after reacting the hydroxyalkanoate-lactide copolymer with alcohol in the presence of the catalyst, alkyl 3-hydroxy as a reaction product is produced in the reactor by alcohol decomposition of the hydroxyalkanoate-lactide copolymer. In addition to propionate and alkyl lactate, remaining solvents, alcohol, and hydroxyalkanoate-lactide copolymer may be included. Accordingly, a process of separating the final products, alkyl 3-hydroxypropionate and alkyl lactate, may be involved.

Specifically, cooling the reactor to a temperature of 20°C or higher and 40°C or lower to remove alcohol; and recovering alkyl 3-hydroxypropionate and alkyl lactate by adding an aqueous solvent to the reactor.

The aqueous solvent may include a mixed solvent of water and ethyl acetate.

Specifically, in the step of adding an aqueous solvent to the reactor, the aqueous solvent may include a mixed aqueous solvent in which 50 parts by weight or more and 99 parts by weight or less of ethyl acetate are mixed with respect to 100 parts by weight of water.

More specifically, in the step of recovering alkyl 3-hydroxypropionate and alkyl lactate by adding an aqueous solvent to the reactor, the aqueous solvent contains 50 parts by weight or more and 60 parts by weight of ethyl acetate based on 100 parts by weight of water. or more, 70 parts by weight or more, 75 parts by weight or more, 99 parts by weight or less, 95 parts by weight or more, 50 parts by weight or more, 99 parts by weight or less, 60 parts by weight or more, 99 parts by weight or less, 70 parts by weight or more, 99 parts by weight or less, 75 A mixed aqueous solvent mixed in an amount of not less than 99 parts by weight, not less than 50 parts by weight but not more than 95 parts by weight, not less than 60 parts by weight but not more than 95 parts by weight, not less than 70 parts by weight but not more than 95 parts by weight, and not less than 75 parts by weight and not more than 95 parts by weight. It can be included.

Specifically, in the step of recovering alkyl 3-hydroxypropionate and alkyl lactate by adding an aqueous solvent to the reactor, as a mixed solvent of water and ethyl acetate is used as an aqueous solvent, the density of water and ethyl acetate Depending on the difference, it can be separated into water in the lower layer and ethyl acetate in the upper layer.

At this time, the lower layer is removed and the upper layer is recovered, so that alkyl 3-hydroxypropionate and alkyl lactate can be extracted. By further concentrating the recovered upper layer, high purity alkyl 3-hydroxypropionate and alkyl lactate can be recovered.

In the step of recovering alkyl 3-hydroxypropionate and alkyl lactate by adding an aqueous solvent to the reactor, the weight-based recovery rate of alkyl 3-hydroxypropionate and alkyl lactate is 50% or more, 60%. or more, 70% or more, 80% or more, may be 99.9% or less, 99% or less, 50% or more but 99.9% or less, 60% or more and 99.9% or less, 70% or more and 99.9% or less, 80% or more and 99.9% It may be 50% or more and 99% or less, 60% or more and 99% or less, 70% or more and 99% or less, and 80% or more and 99% or less.

Specifically, the recovery rate is calculated by measuring the weight (Y) of the hydroxyalkanoate-lactide copolymer introduced into the reactor and the weight (X) of the final recovered alkyl 3-hydroxypropionate and alkyl lactate, and The recovery rates of the alkyl 3-hydroxypropionate and alkyl lactate can be calculated by substituting each into Equation 1 below.

[Equation 1]

Recovery of alkyl 3-hydroxypropionate and alkyl lactate (%) = X/Y * 100

In Equation 1,

In addition, after the step of recovering alkyl 3-hydroxypropionate and alkyl lactate by adding an aqueous solvent to the reactor, the purity of the recovered alkyl 3-hydroxypropionate and alkyl lactate was 50% or more, 60%. % or more, 70% or more, 80% or more, 90% or more, 99.9% or less, 99% or less, 50% or more but 99.9% or less, 60% or more but 99.9% or less, 70% or more but 99.9% or less, 80% It may be 99.9% or less, 90% or more and 99.9% or less, 50% or more and 99% or less, 60% or more and 99% or less, 70% or more and 99% or less, 80% or more and 99% or less, and 90% or more and 99% or less.

The method for measuring the purity is not greatly limited, but, for example, it can be measured by analyzing the finally recovered alkyl 3-hydroxypropionate using nuclear magnetic resonance spectroscopy (NMR).

According to the present invention, an environmentally friendly and economical method is provided to produce alkyl 3-hydroxypropionate and alkyl lactate in high purity and high yield by alcoholizing hydroxyalkanoate-lactide copolymer. It can be.

The invention is explained in more detail in the following examples. However, the following examples only illustrate the present invention, and the content of the present invention is not limited by the following examples.

Preparation example: Preparation of 3-hydroxypropionate-lactide block copolymer

(1) Production of polylactic acid prepolymer

25 g of 85% L-lactic acid aqueous solution was added to a 100 ml Schlenk flask in an oil bath and the pressure was reduced for 2 hours at 70°C and 50 mbar to remove moisture in L-lactic acid. Afterwards, based on 100 parts by weight of lactate, 0.4 parts by weight of p-toluenesulfonic acid (p-TSA) and 0.1 parts by weight of SnCl ₂ catalyst were respectively added, and a melt condensation polymerization reaction was performed at a temperature of 150° C. for 12 hours. After the reaction was completed, the reactant was dissolved in chloroform and extracted with methanol to obtain a polylactic acid prepolymer (weight average molecular weight: 8,000 g/mol).

(2) Poly(3-hydroxypropionate) prepolymer production

Add 25 ml of 60% 3-hydroxypropionate aqueous solution to a 100 ml Schlenk flask in an oil bath, remove moisture in the 3-hydroxypropionate for 3 hours at 50 ℃ and 50 mbar, and then incubate at 70 ℃ and After oligomerization at 20 mbar for 2 hours, 0.4 parts by weight of p-toluenesulfonic acid (p-TSA) catalyst based on 100 parts by weight of 3-hydroxypropionate was added to the reaction flask, and incubated at a temperature of 110°C for 24 hours. A melt condensation reaction was performed. After the reaction was completed, the reactant was dissolved in chloroform and extracted with methanol to obtain poly(3-hydroxypropionate) prepolymer (weight average molecular weight: 26,000 g/mol).

(3) Preparation of block copolymers

The polylactic acid prepolymer and the poly(3-hydroxypropionate) prepolymer were mixed in a 100 ml Schlenk flask in an oil bath at a weight ratio of 9:1, added to a total content of 30 g, and p-toluenesulfonic acid ( 90 mg of p-TSA) was added, and annealing was performed at 60°C for 3 hours. Afterwards, 3-hydroxypropionate-lactide block copolymer (weight average molecular weight: 130,000 g/mol) was prepared by solid-phase polymerization reaction using an evaporator and mixing at 150°C and 0.5 mbar for 24 hours.

Meanwhile, the weight average molecular weight of the polylactic acid prepolymer, poly(3-hydroxypropionate) prepolymer, and block copolymer was measured using gel permeation chromatography (GPC).

Example 1

10 g of the block copolymer prepared in the above preparation example and 79.2 g of methanol (density: 0.792 g/ml, 100 ml) were added to the reactor, stirred, and 100 μl of sulfuric acid (H ₂ SO ₄ , neat) was added. Afterwards, the temperature inside the reactor was heated to 90°C and stirred for 6 hours. After the reaction was completed, the temperature of the product was cooled to 25°C to remove methanol. Afterwards, the conversion rate to methyl 3-hydroxypropionate and methyl lactate was confirmed by ¹ H NMR.

Afterwards, 100 g (100 ml) of water and 90 g (100 ml) of ethyl acetate were added to the reactor to extract methyl 3-hydroxypropionate and methyl lactate, the layers were separated, and ethyl acetate was concentrated and removed.

evaluation

1. Conversion rate evaluation

In Examples and Comparative Examples, the conversion rate of hydroxyalkanoate-lactide copolymer to alkyl 3-hydroxypropionate and alkyl lactate was measured by nuclear magnetic resonance spectroscopy (NMR), and the results are shown in the table below. It is shown in ‘Conversion Rate’ of 1.

Specifically, 100 μL of the reaction solution was sampled and dissolved in 600 μL of DMSO-d6, an NMR solvent, to prepare a sample for ¹ H-NMR measurement, and the sample was used to obtain ^{a 1} H-NMR spectrum (AVANCE Ⅲ HD FT-NMR spectrometer) (500 MHz for 1H), manufactured by Bruker) was measured to confirm the conversion rate.

2. Recovery rate evaluation

The recovery rates of alkyl 3-hydroxypropionate and alkyl lactate prepared in Examples and Comparative Examples were calculated, and the results are shown in Table 1 below.

Specifically, the weight (Y) of the hydroxyalkanoate-lactide copolymer and the weight (X) of the finally recovered alkyl 3-hydroxypropionate and alkyl lactate were measured, and these were respectively substituted into Equation 1 below. The recovery rate was calculated.

[Equation 1]

Recovery rate (%) = X/Y * 100

3. Purity evaluation

The purity of the alkyl 3-hydroxypropionate and alkyl lactate prepared in Examples and Comparative Examples was measured by nuclear magnetic resonance spectroscopy (NMR), and the results are shown in ‘Purity’ in Table 1 below.

Specifically, 100 μL of the finally recovered alkyl 3-hydroxypropionate and alkyl lactate were sampled and dissolved in 600 μL of DMSO-d6, an NMR solvent, to prepare a sample for ¹ H-NMR measurement, and the sample was used Purity was confirmed by measuring ¹ H-NMR spectrum (AVANCE Ⅲ HD FT-NMR spectrometer (500 MHz for 1H), manufactured by Bruker).

Conversion Rate (%) Recovery rate (%) water(%) Example 1 89.5 83.5 98.5

According to Table 1, the Examples have excellent conversion and recovery rates to alkyl 3-hydroxypropionate and alkyl lactate, and the fraction contained in the finally recovered alkyl 3-hydroxypropionate and alkyl lactate It was found that the water content was low.

Claims (14)

Comprising: reacting the hydroxyalkanoate-lactide copolymer with alcohol in the presence of a catalyst,
A method for producing alkyl 3-hydroxypropionate and alkyl lactate, wherein the catalyst includes an acid catalyst or a metal salt.
According to paragraph 1,
In the step of reacting the hydroxyalkanoate-lactide copolymer with alcohol in the presence of the catalyst,
A method for producing alkyl 3-hydroxypropionate and alkyl lactate, wherein the alcohol is included in an amount of 110 parts by weight to 1000 parts by weight based on 100 parts by weight of the hydroxyalkanoate-lactide copolymer.
According to paragraph 1,
In the step of reacting the hydroxyalkanoate-lactide copolymer with alcohol in the presence of the catalyst,
A method for producing alkyl 3-hydroxypropionate and alkyl lactate, wherein the catalyst is included in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the hydroxyalkanoate-lactide copolymer.
According to paragraph 1,
A method for producing alkyl 3-hydroxypropionate and alkyl lactate, wherein the catalyst comprises sulfuric acid.
According to paragraph 1,
The catalyst is a method for producing alkyl 3-hydroxypropionate and alkyl lactate, wherein the catalyst includes one or more metal salts selected from the group consisting of metal halogen salts, phosphates, nitrates, sulfates, ammonium salts, acetates, and carbonates.
According to paragraph 1,
A method for producing alkyl 3-hydroxypropionate and alkyl lactate, wherein the alcohol includes at least one alcohol selected from the group consisting of methanol, ethanol, and butanol.
According to paragraph 1,
A method for producing alkyl 3-hydroxypropionate and alkyl lactate, wherein the hydroxyalkanoate-lactide copolymer is a 3-hydroxypropionate-lactide copolymer.
In clause 7,
The 3-hydroxypropionate-lactide copolymer is a block copolymer in which polylactic acid prepolymer and poly(3-hydroxypropionate) prepolymer are polymerized. Preparation of alkyl 3-hydroxypropionate and alkyl lactate method.
According to paragraph 1,
Method for producing alkyl 3-hydroxypropionate and alkyl lactate, wherein the alkyl 3-hydroxypropionate includes alkyl 3-hydroxypropionate represented by the following formula (1):
[Formula 1]

In Formula 1,
R ₁ is an alkyl group having 1 to 20 carbon atoms.
According to paragraph 1,
Method for producing alkyl 3-hydroxypropionate and alkyl lactate, wherein the alkyl lactate includes an alkyl lactate represented by the following formula (2):
[Formula 2]

In Formula 2,
R ₂ is an alkyl group having 1 to 20 carbon atoms.
According to paragraph 1,
Reacting the hydroxyalkanoate-lactide copolymer with alcohol in the presence of the catalyst;
Injecting hydroxyalkanoate-lactide copolymer and alcohol into the reactor;
adding a catalyst to the reactor; and
A method for producing alkyl 3-hydroxypropionate and alkyl lactate, comprising: heating the reactor to a temperature of 50°C or more and 100°C or less and stirring for 5 hours or more and 20 hours or less.
According to paragraph 1,
After reacting the hydroxyalkanoate-lactide copolymer with alcohol in the presence of the catalyst,
Removing alcohol by cooling the reactor to a temperature of 20°C or higher and 40°C or lower; and
A method for producing alkyl 3-hydroxypropionate and alkyl lactate, comprising: recovering alkyl 3-hydroxypropionate and alkyl lactate by adding an aqueous solvent to the reactor.
According to clause 12,
In the step of recovering alkyl 3-hydroxypropionate and alkyl lactate by adding an aqueous solvent to the reactor, alkyl 3-hydroxypropionate and alkyl lactate have a weight-based recovery rate of 50% or more. Process for preparing hydroxypropionate and alkyl lactate.
According to clause 12,
In the step of recovering alkyl 3-hydroxypropionate and alkyl lactate by adding an aqueous solvent to the reactor, alkyl 3-hydroxypropionate and alkyl lactate have a purity of 50% or more. Process for preparing cypionate and alkyl lactate.