WO2014080876A1 - 気液の向流接触による精留工程を備えるグリコリドの製造方法、及び、粗グリコリドの精製方法 - Google Patents
気液の向流接触による精留工程を備えるグリコリドの製造方法、及び、粗グリコリドの精製方法 Download PDFInfo
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- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
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- B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J2219/24—Stationary reactors without moving elements inside
Definitions
- the present invention relates to a method for efficiently and economically producing high-purity glycolide for a long period of time by depolymerization of polyglycolic acid and a method for purifying crude glycolide.
- Glycolide obtained by the production method and purification method of the present invention is useful as a monomer for ring-opening polymerization for producing polyglycolic acid (hereinafter sometimes referred to as “PGA”). More specifically, the glycolide obtained by the production method of the present invention is subjected to ring-opening polymerization alone or copolymerized with another comonomer to obtain polyglycolide (that is, polyglycolic acid) or various copolymers. be able to. Polyglycolic acid (copolymer) is useful as a biodegradable polymer material or a medical polymer material.
- the method for producing glycolide of the present invention can be applied to a method for producing glycolide via a low molecular weight polyglycolic acid such as a glycolic acid oligomer.
- the method for purifying crude glycolide according to the present invention is also useful as a method for recycling product waste or molding waste of high molecular weight polyglycolic acid into monomeric glycolide for recycling.
- Aliphatic polyesters such as polyglycolic acid and polylactic acid are hydrolyzed in vivo, and are metabolized by microorganisms into natural water and carbon dioxide under natural environment. For this reason, aliphatic polyester attracts attention as a biodegradable polymer material that can be substituted for medical materials and general-purpose resins.
- polyglycolic acid is highly biodegradable, and, for example, in addition to high hydrolyzability using an alkaline solution, mechanical properties such as heat resistance and tensile strength, and In particular, the gas barrier property when a film or sheet is also excellent. For this reason, polyglycolic acid is expected to be used as agricultural materials, various packaging (container) materials and medical polymer materials, and is being developed for use alone or in combination with other resin materials.
- PGA can be synthesized by dehydration polycondensation of glycolic acid as a monomer.
- glycolic acid as a starting material
- high molecular weight PGA is synthesized by polymerization.
- PGA is a glycolic acid (ie, ⁇ -hydroxyacetic acid) represented by the following formula [I]
- glycolide having the structure of a bimolecular cyclic ester of glycolic acid is converted into the following formula [II] in the presence of a catalyst such as tin octoate.
- the high molecular weight PGA (ie, polyglycolide) is synthesized by ring-opening polymerization according to the above.
- glycolide In order to mass-produce high molecular weight PGA using glycolide as a raw material on an industrial scale, it is essential to efficiently and economically supply high-purity glycolide. However, it has been difficult to efficiently and economically synthesize glycolide.
- Glycolide is a dimer cyclic ester having a structure in which two molecules of water are eliminated by an esterification reaction of two molecules of glycolic acid.
- glycolic acid when glycolic acid is simply esterified with each other, it is usually a glycolic acid oligomer.
- a low molecular weight polymer such as a dimer cyclic ester cannot be obtained in a high yield. Therefore, after synthesizing a glycolic acid oligomer, a method of depolymerizing the oligomer to produce glycolide is employed.
- Patent Document 1 a glycolic acid oligomer is crushed into a powder form, and a pulverized product is fed to a reactor at a small rate of about 20 g / hour. (6 to 2.0 kPa), a method of heating to 270 to 285 ° C. for depolymerization and cooling and solidifying the produced gaseous glycolide to recover.
- Patent Document 2 discloses that a polyether having excellent thermal stability is used as a substrate and a small amount of glycolic acid is block copolymerized to form a block copolymer.
- the glycolide thus obtained contains impurities (mainly glycolic acid oligomers used and glycolic acid that is a raw material thereof), conventionally various solvents such as isopropanol, t-amyl alcohol, Purification is performed by recrystallization using carbon chloride, ethyl acetate or the like. The crystal slurry of glycolide obtained by recrystallization is washed with the solvent or other washing liquid used for recrystallization while performing solid-liquid separation such as filtration, and then purified crystals are obtained by removing the solvent or washing liquid by drying. ing.
- impurities mainly glycolic acid oligomers used and glycolic acid that is a raw material thereof
- solvents such as isopropanol, t-amyl alcohol
- Purification is performed by recrystallization using carbon chloride, ethyl acetate or the like.
- the crystal slurry of glycolide obtained by recrystallization is washed with the solvent or other washing liquid used for recrystallization while
- such a purification method includes a drying step for removing the solvent or washing liquid from the crystal surface, a cooling / recovery step for the solvent or washing solution removed in the drying step, and a distillation separation step for the mixture of the collected solvent and washing solution. It must be prepared and the process is complicated. Drying is carried out below the melting point of the crystal, but cyclic esters such as glycolide are sublimable, so that if the degree of vacuum is too high during drying, crystal loss increases. In addition, impurities may be taken into the crystal, and in order to remove this, several recrystallizations are required, so the process is more complicated.
- Patent Document 4 discloses a method using a high-boiling organic solvent in a method for producing an ⁇ -hydroxycarboxylic acid dimer cyclic ester by depolymerizing an ⁇ -hydroxycarboxylic acid oligomer. It is disclosed. In this production method, a mixture containing 30 to 5,000 parts by weight of a high-boiling organic solvent with respect to 100 parts by weight of an ⁇ -hydroxycarboxylic acid oligomer is heated to a temperature at which depolymerization occurs to obtain a substantially uniform solution.
- a dimer cyclic ester can be obtained in high yield from an ⁇ -hydroxycarboxylic acid oligomer while preventing the oligomer from becoming heavy.
- Patent Document 4 also describes a method for purifying a crude ⁇ -hydroxycarboxylic acid dimer cyclic ester by applying this method.
- Patent Document 5 also describes a method for purifying a crude cyclic ester by applying the method.
- Patent Document 6 an oligomer of ⁇ -hydroxycarboxylic acid, an ester or a salt thereof is added to a solvent to which a catalyst is added, and the mixture is agitated by heating and catalytically decomposed.
- a method is disclosed. This method is carried out at normal pressure or under pressure using a solvent suitable for entraining the cyclic ester in the gas phase, and the cyclic ester and the solvent are recovered by condensing the gas phase.
- This document shows a specific example of catalytic decomposition of a lactic acid oligomer using dodecane (boiling point: about 214 ° C.) as a solvent.
- a dimer cyclic ester of ⁇ -hydroxycarboxylic acid such as glycolide is distilled along with an organic solvent having a high boiling point.
- Recovery of the cyclic ester such as glycolide from the distillate is performed by cooling the distillate and adding a non-solvent of cyclic ester such as glycolide as necessary to solidify and precipitate the cyclic ester such as glycolide. This is done by solid-liquid separation.
- the crystals of cyclic esters such as glycolide obtained in this way have low purity, and as described above, in addition to containing impurities, they have high boiling points that are difficult to remove by ordinary drying. Since an organic solvent is attached, in order to obtain a high-purity dried crystal, in addition to the above-described purification operation, an operation for further removing the organic solvent attached to the crystal is essential.
- the conventional method of purifying a cyclic ester such as glycolide and removing the organic solvent adhering to the crystal is performed by substituting and washing the obtained crystal with a low boiling point washing liquid such as cyclohexane or ether and then removing the washing liquid by drying. Is called. Drying is carried out below the melting point of the crystal. Since cyclic esters such as glycolide are sublimable, if the degree of vacuum is excessively high during drying, the loss of crystals is large and the yield of cyclic esters such as glycolide decreases. Further, if necessary, recrystallization may be performed with ethyl acetate or the like. In this case, the organic solvent adhering to the crystals is removed by drying.
- a new low boiling point cleaning liquid is essential to replace the organic solvent attached to the crystals.
- the cleaning waste liquid becomes a mixed liquid of the high boiling point organic solvent and the low boiling point cleaning liquid.
- the above-described purification method for crystals of cyclic ester such as glycolide is a drying process for removing the cleaning liquid from the crystal surface, a recovery process for the cleaning liquid removed by drying, and purification of a cleaning waste liquid containing a high boiling organic solvent and a low boiling cleaning liquid.
- a recovery process for the cleaning liquid removed by drying has a recovery process and the process is complicated.
- the cleaning liquid used for example alcohol, may react with the cyclic ester to cause a transesterification reaction.
- impurities are taken into the crystal, the process is more complicated because several recrystallizations are required.
- Patent Document 7 [first step] ⁇ -hydroxycarboxylic acid such as glycolic acid and / or ⁇ -hydroxycarboxylic acid condensate such as glycolic acid condensate is produced.
- a method is described for producing a cyclic dimer ester comprising two steps of obtaining a cyclic dimer ester while heating and simultaneously carrying out the reaction and distillation.
- a glycolic acid condensate is charged into a 500 ml flask, polyethylene glycol (liquid, boiling point 314 ° C., weight average molecular weight about 400) is added, and glycolic acid condensation is performed under a reduced pressure of 1.0 kPa under a nitrogen atmosphere.
- the mixture of the product and polyethylene glycol is heated to 230 ° C. to advance the polymerization reaction.
- the depolymerization reaction starts, glycolide, which is a cyclic dimer ester, is distilled out and accumulated in the receiver, the second step is started, and the glycolide distillation is substantially stopped until Heating at temperature to collect glycolide is described.
- the residue was present, and the distillate between the flask and the receiver was found to adhere to the distillate, but the amount accumulated was small. Is described.
- Polyglycolic acid is expected to be produced in large quantities and used in large quantities in the future, and recycling of product waste becomes an important issue. Recycling of molding waste produced as a by-product during the molding of polyglycolic acid is also an issue.
- a method for producing glycolide by depolymerization of glycolic acid oligomers a method for stably producing high-purity glycolide efficiently and economically is desired.
- An object of the present invention is to provide a method for stably and efficiently producing high-purity glycolide by depolymerization of a glycolic acid oligomer and an efficient and economical method for purifying crude glycolide. It is in.
- the present inventors have studied to solve the above-mentioned object, and depolymerizing the glycolic acid oligomer composition containing the glycolic acid oligomer by heating.
- the glycolide produced by the reaction may contain trace amounts of impurities such as free acid and solvent used in the depolymerization reaction, and the concentration of the free acid contained may be It has been found that it influences the temporal stability of the produced glycolide, and also affects the efficiency, economic efficiency and long-run property of the glycolide production method.
- glycolide generated by depolymerization reaction may be simply referred to as “glycolide”). It was found that (heaviness) proceeds.
- glycolide containing glycolic acid as a free acid at a free acid concentration of 0.85 mmol / g (hereinafter referred to as “GL0.85”), glycolide containing glycolic acid at a free acid concentration of 0.16 mmol / g. (Hereinafter referred to as “GL0.16”) and glycolide containing no glycolic acid (hereinafter referred to as “GL0.0”) in a nitrogen atmosphere at a temperature of 110 ° C., respectively, Looking at the change in (mass%), as shown in FIG. 1, even after 5.5 hours, GL0.0.
- the increase in the haze value is presumed to be the result of oligomerization of glycolide, so that glycolide in which free acid such as free carboxylic acid is present at a free acid concentration of about 0.85 mmol / g is only a few hours later. It was found that the glycolide is oligomerized, that is, heavier, has poor temporal stability, and lacks practical utility.
- the generated glycolide has a free acid concentration of 0.6 mmol / g or less from the viewpoint of practicality. It was found that the free acid concentration is preferably 0.55 mmol / g or less, more preferably the free acid concentration is 0.52 mmol / g or less.
- the measuring method of the free acid concentration of glycolide and the measuring method of the haze value of glycolide are as follows.
- the free acid concentration in glycolide is measured by the following method. That is, 30 mg of a glycolide sample is dissolved in a mixed solvent of 25 ml of acetone and 25 ml of methanol. A methanol solution containing sodium methoxide is titrated as a neutralizing solution to detect the neutralization point. From the detected neutralization point, the free acid concentration present in 1 g of glycolide sample is calculated as the number of mmols (unit: mmol / g).
- the measurement of the change over time of the residual ratio (mass fraction) and haze value of glycolide was performed by the following method. That is, glycolide (purity 99.96% by mass or more) and a predetermined amount of glycolic acid were added to a sample bottle with a volume of 10 ml, and after nitrogen was sealed, it was immersed in an oil bath at a temperature of 110 ° C. and left to stand.
- the residual ratio of glycolide was measured by the following method. That is, 100 mg of a sample containing glycolide and a predetermined amount of glycolic acid collected when the predetermined time passed, and 40 mg of p-chlorobenzophenone (manufactured by Tokyo Chemical Industry Co., Ltd.) as an internal standard substance, Dissolved in 10 ml of acetone. Next, 2 ⁇ l of the lysate is sampled and injected into a gas chromatography apparatus, the amount of glycolide is measured, and a calibration curve prepared beforehand using glycolide and p-chlorobenzophenone as an internal standard substance is used. Thus, the purity of glycolide remaining in the sample was determined.
- Residual rate of glycolide (a / b) ⁇ 100 a: Mass of glycolide remaining in the sample (g) b: Mass of glycolide previously added to the sample bottle (g)
- the haze value of glycolide was measured using Water Analyzer 2000N (manufactured by Nippon Denshoku Industries Co., Ltd.). Specifically, 100 mg of a sample containing glycolide and a predetermined amount of glycolic acid collected as described above is completely dissolved in 20 ml of acetone in an Erlenmeyer flask having a volume of 50 ml using an ultrasonic vibrator. The sample dissolved in the analysis cell was added, and the haze value (unit:%) was measured to obtain the haze value when the predetermined time passed.
- a glycolic acid oligomer composition comprising a glycolic acid oligomer composition, preferably a glycolic acid oligomer and a high-boiling organic solvent having a boiling point in the range of 220 to 500 ° C. at normal pressure
- the present inventors have found that the problem can be solved by introducing glycolide generated by heating the composition into a rectifier and performing rectification by countercurrent contact of gas and liquid, thereby completing the present invention.
- the present inventors have found that the problem can be solved by heating the crude glycolide composition, introducing it into a rectifier, and performing rectification by countercurrent contact of gas and liquid, thereby completing the present invention. did.
- Step (1) supplying a glycolic acid oligomer composition to a reaction vessel and heating to a temperature at which a depolymerization reaction of the glycolic acid oligomer occurs under normal pressure or reduced pressure;
- Step (2) is a step in which glycolide is generated by further depolymerizing the glycolic acid oligomer by continuing heating.
- Step (3) a step of distilling the produced glycolide from the reaction vessel, Step (4) Introducing distillate into a rectifier and rectifying by countercurrent contact of gas and liquid, and Process (5)
- recovering glycolide is provided,
- glycolic acid oligomer composition is a glycolic acid oligomer composition containing a glycolic acid oligomer and a high-boiling organic solvent having a boiling point of 220 to 500 ° C. at normal pressure. .
- step (3) is a step of distilling the produced glycolide together with the high boiling point organic solvent from the reaction vessel.
- the high-boiling organic solvent is an aromatic carboxylic acid alkoxyalkyl ester, aliphatic carboxylic acid alkoxyalkyl ester, polyalkylene glycol ether, polyalkylene glycol ester, aromatic carboxylic acid ester, aliphatic carboxylic acid ester, aromatic
- the method for producing glycolide as described above which is at least one selected from the group consisting of aliphatic ethers, aliphatic ethers, aromatic phosphate esters, aliphatic phosphate esters, aliphatic imide compounds, aliphatic amide compounds, and aromatic halides .
- the high boiling point organic solvent is represented by the formula (1) X—O — (— R—O—) p —Y (1)
- R represents a methylene group or a linear or branched alkylene group having 2 to 8 carbon atoms, and X and Y each independently represent a methyl group or an alkyl group having 2 to 20 carbon atoms, or Represents an aryl group
- p represents an integer of 1 or more, and when p is 2 or more, the plurality of R may be the same or different.
- the manufacturing method of the said glycolide which is at least 1 type of polyalkylene glycol ether represented by these.
- glycolic acid oligomer composition is a glycolic acid oligomer composition containing a solubilizer.
- glycolic acid oligomer composition is a glycolic acid oligomer composition not containing a high boiling point organic solvent having a boiling point in the range of 220 to 500 ° C. at normal pressure.
- Step (i) supplying the crude glycolide composition to the reaction vessel and heating it under normal pressure or reduced pressure to distill glycolide.
- Step (ii) introducing the distillate into a rectifier and rectifying it by gas-liquid countercurrent contact; and
- a method for purifying crude glycolide comprising the step (iii) of recovering glycolide.
- the crude glycolide composition is a crude glycolide composition containing crude glycolide and a high-boiling organic solvent having a boiling point of 220 to 500 ° C. at normal pressure, and The method for purifying crude glycolide, wherein the step (i) is a step of distilling glycolide together with the high-boiling organic solvent.
- an apparatus for producing glycolide comprising a reaction vessel and a rectifier, and a crude glycolide comprising a reaction vessel and a rectifier.
- a purification device is provided.
- Step (1) supplying a glycolic acid oligomer composition to a reaction vessel and heating to a temperature at which a depolymerization reaction of the glycolic acid oligomer occurs under normal pressure or reduced pressure;
- Step (2) is a step in which glycolide is generated by further depolymerizing the glycolic acid oligomer by continuing heating.
- Step (3) a step of distilling the produced glycolide from the reaction vessel, Step (4) Introducing distillate into a rectifier and rectifying by countercurrent contact of gas and liquid, and Step (5) Since the glycolide production method includes a step of recovering glycolide, the concentration of the free acid in the glycolide distillate can be reduced, and thus the efficiency, economy and long run properties are excellent. There is an effect that it is possible to provide a method for producing high-purity glycolide.
- the glycolic acid oligomer composition is a glycolic acid oligomer composition containing a glycolic acid oligomer and a high-boiling organic solvent having a boiling point of 220 to 500 ° C. at normal pressure, and more preferably
- the step (3) is the glycolide production method described above, which is a step of distilling the produced glycolide together with the high-boiling organic solvent from the reaction vessel, the concentration of free acid in the glycolide distillate can be further reduced. Therefore, there is an effect that it is possible to provide a method for producing high-purity glycolide, which is further excellent in efficiency, economy, and long-run property.
- glycolide having high purity can be recovered.
- post-treatment such as crystallization and recrystallization, which has been necessary in the past, becomes easy, and in some cases, crystallization and recrystallization are omitted.
- the glycolic acid oligomer composition is more preferably a glycolic acid oligomer composition containing a glycolic acid oligomer and a high-boiling organic solvent having a boiling point of 220 to 500 ° C. at normal pressure. Since the glycolide produced is distilled from the reaction vessel together with the high boiling point organic solvent, the concentration of the free acid in the resulting glycolide can be further reduced, so that the efficiency, economy, and long run properties are reduced.
- Step (i) supplying the crude glycolide composition to the reaction vessel and heating it under normal pressure or reduced pressure to distill glycolide.
- Step (ii) introducing the distillate into a rectifier and rectifying it by gas-liquid countercurrent contact; and
- Step (iii) A method for purifying glycolide characterized in that it comprises a step of recovering glycolide, whereby high yields of glycolide with a low or almost no impurity content and reduced free acid concentration are obtained. The effect that the purification method of the crude glycolide which can be obtained at a rate can be provided.
- a glycolide production apparatus or a crude glycolide purification apparatus comprising a reaction vessel and a rectifier.
- Glycolide is excellent in stability because it can continue the reaction for a long period of time without a decrease in efficiency, and depolymerizes glycolic acid oligomers efficiently to reduce impurities such as free acids.
- the production of glycolide or the purification apparatus of crude glycolide that can purify crude glycolide can be provided.
- the method for producing glycolide of the present invention is a method for producing glycolide by depolymerizing a glycolic acid oligomer.
- the glycolic acid oligomer (hereinafter sometimes referred to as “GAO”) used as a starting material in the present invention is a glycolic acid polymer or glycolic acid polymer containing a repeating unit capable of generating glycolide by depolymerization. It is a copolymer.
- GAO can be obtained by (co) polycondensation using glycolic acid or an alkyl ester or salt thereof, and ring-opening (co) polymerization using glycolide as a monomer. Can be obtained.
- the GAO used in the present invention is a (co) polymer having a weight average molecular weight of 3,000 or more, in many cases 5,000 or more, preferably 8,000 or more, more preferably 10,000 or more.
- the upper limit of the weight average molecular weight of GAO is usually about 80,000, and in many cases about 50,000.
- the weight average molecular weight is a value measured using gel permeation chromatography (GPC), and can be measured as a standard polymethyl methacrylate (PMMA) conversion value by GPC measurement using hexafluoroisopropanol (HFIP) as a solvent. .
- GAO may be a copolymer of glycolic acid.
- examples of comonomers that can be copolymerized with glycolic acid include ⁇ -hydroxycarboxylic acids such as lactic acid, ⁇ -hydroxybutyric acid, and ⁇ -hydroxyvaleric acid. These dimeric cyclic esters may be used.
- GAO is a copolymer of glycolic acid, the content of glycolic acid repeating units is 50% by mass or more, preferably 80% by mass or more, more preferably 90% by mass or more, and further preferably 95% by mass or more. It is desirable that it is a copolymer.
- GAO can be synthesized according to a conventional method. For example, glycolic acid or an ester or salt thereof, and a comonomer to be used, if necessary, at a temperature of 100 to 250 ° C., preferably 140 ° C. under reduced pressure or increased pressure in the presence of a condensation catalyst or a transesterification catalyst as necessary. Heating to ⁇ 230 ° C., the condensation reaction or transesterification reaction is carried out until the distillation of low molecular weight substances such as water and alcohol substantially disappears. After completion of the condensation reaction or transesterification reaction, the produced GAO can be used as it is as a raw material for the depolymerization according to the present invention.
- the obtained GAO can be taken out from the reaction system and washed with a non-solvent such as benzene or toluene to remove unreacted substances, catalyst, and the like.
- a non-solvent such as benzene or toluene to remove unreacted substances, catalyst, and the like.
- the structure of GAO may be cyclic or linear.
- Other GAOs can be synthesized by the same method.
- GAO may have a low degree of polymerization, but the melting point (Tm) is usually 140 ° C. or higher, preferably 160 ° C. or higher, more preferably 180 ° C. or higher, from the viewpoint of the yield of glycolide upon depolymerization. belongs to.
- Tm is a melting point detected when the temperature is increased at a rate of 20 ° C./min in an inert gas atmosphere using a differential scanning calorimeter (DSC).
- GAO used to produce glycolide by depolymerization can be synthesized by ring-opening (co) polymerization of glycolide, but wastes and molding waste of used PGA products can be suitably used. Therefore, recycling can be achieved.
- the shape of the used PGA product is not particularly limited, and may be any shape such as a plate shape, a film shape, a thread shape, a spherical shape, a columnar shape, or a rod shape. In order to increase the reaction efficiency, it is preferable that these be in the form of granules, powder, fibers or the like before the depolymerization reaction. Therefore, it can be granulated or powdered by pulverization or melting, or processed into a fiber by melting or stretching, and then subjected to a depolymerization reaction.
- GAO may be supplied all at once to a reaction vessel such as a reaction vessel before the depolymerization reaction, or may be supplied by continuous addition or divided addition during the depolymerization reaction.
- the GAO in the reaction vessel preferably has a residual ratio of the GAO melt phase of 0.5 or less, and the GAO melt phase and the high-boiling organic solvent It is preferable that a substantially uniform phase (solution state) can be formed.
- a separate pre-reaction vessel is provided so that the GAO melt phase and the high-boiling organic solvent liquid phase form a more uniform phase. You may introduce
- a substantially uniform phase may be formed by further containing a solubilizer described later.
- the method for producing glycolide by depolymerizing the GAO of the present invention includes the following steps (1) to (5): Step (1) A step of supplying a GAO composition to a reaction vessel and heating to a temperature at which a depolymerization reaction of the GAO occurs under normal pressure or reduced pressure.
- Step (2) Further, heating is continued to depolymerize GAO to produce glycolide, Step (3) a step of distilling the produced glycolide from the reaction vessel, Step (4) Introducing distillate into a rectifier and rectifying by countercurrent contact of gas and liquid, and Step (5)
- a method for producing glycolide comprising a step of recovering glycolide, preferably, the GAO composition has a high boiling point in which the boiling point at GAO and atmospheric pressure is in the range of 220 to 500 ° C.
- This is a method for producing glycolide, which is a GAO composition containing an organic solvent (hereinafter sometimes simply referred to as “high boiling point organic solvent”).
- the boiling point of the high-boiling organic solvent at normal pressure is in the range of 220 to 500 ° C, preferably 230 to 470 ° C, more preferably 240 to 450 ° C.
- the rectification step is performed in the presence of a high-boiling organic solvent so that the mixture containing glycolide adheres to the inner wall of the line in the rectification step and the subsequent recovery step. Further, it is possible to prevent the production of glycolide from being continued for a long time and to prevent the recovery amount of glycolide from decreasing, that is, increasing the loss of GAO.
- the high-boiling organic solvent is usually 10 to 3,000 parts by weight, preferably 20 to 2,700 parts by weight, more preferably 40 to 2,300 parts by weight, particularly preferably 50 to 2, parts by weight based on 100 parts by weight of GAO. 000 parts by weight is used.
- the high-boiling organic solvent may be added continuously or divided during the depolymerization reaction, as long as the mixture in the depolymerization reaction system preferably forms a substantially uniform liquid phase.
- the high boiling point organic solvent having a boiling point of 220 to 500 ° C. at normal pressure is not particularly limited, but is preferably selected from a group of compounds having high thermal stability.
- high-boiling organic solvents include aromatic carboxylic acid alkoxyalkyl esters, aliphatic carboxylic acid alkoxyalkyl esters, polyalkylene glycol ethers, polyalkylene glycol esters, aromatic carboxylic acid esters, aliphatic carboxylic acid esters, aromatics.
- Examples include ethers, aliphatic ethers, aromatic phosphate esters, aliphatic phosphate esters, aliphatic imide compounds, aliphatic amide compounds, and aromatic halides. Use at least one selected from the group consisting of these. That's fine.
- (A) Group solvent Among these high-boiling organic solvents whose boiling point at normal pressure is in the range of 220 to 500 ° C., aromatic halide p-chlorobenzophenone; aromatic carboxylic acid alkoxyalkyl ester di (2-methoxyethyl) phthalate, etc.
- Particularly preferred group (a) solvents are polyalkylene glycol ethers, most preferably the following formula (1) X—O — (— R—O—) p —Y (1)
- R represents a methylene group or a linear or branched alkylene group having 2 to 8 carbon atoms
- X and Y each independently represent a methyl group or an alkyl group having 2 to 20 carbon atoms, or Represents an aryl group
- p represents an integer of 1 or more, and when p is 2 or more, the plurality of R may be the same or different. It is at least 1 type of polyalkylene glycol ether represented by these.
- the alkyleneoxy unit (—R—O—) is not particularly limited as long as R is a methylene group or a linear or branched alkylene group having 2 to 8 carbon atoms.
- R is a methylene group or a linear or branched alkylene group having 2 to 8 carbon atoms.
- Specific examples thereof include polyethylene glycol ethers composed of ethyleneoxy units having 2 carbon atoms in R, polypropylene glycol ethers composed of propyleneoxy units having 3 carbon atoms in R, butylene oxy units having 4 carbon atoms in R
- the polybutylene glycol ether which consists of these is mentioned.
- polyethylene glycol ether is particularly preferable in terms of easy availability of raw materials and easy synthesis.
- the ether groups (X and Y) at both ends are each independently a methyl group, an alkyl group having 2 to 20 carbon atoms, or an aryl group, more preferably X and Y are both methyl groups or alkyl groups having 2 to 7 carbon atoms, and the total number of carbon atoms of the alkyl groups contained in the ether groups at both ends is preferably 2 to 10, more preferably 2 to It is desirable to be in the range of 8.
- Examples of such an alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, and a pentyl group. These alkyl groups may be linear or branched.
- the properties of the polyalkylene glycol ether also change depending on the number of repetitions p of the alkyleneoxy unit (—R—O—) in the formula (1).
- a polyalkylene glycol ether having a repeating number p of preferably 2 to 10, more preferably 3 to 9, and further preferably 4 to 8 may be used.
- this repeating number p becomes large, the degree of polymerization distribution tends to be wide during synthesis by polyaddition reaction, and it becomes difficult to isolate polyalkylene glycol ethers having the same number of repeating units.
- the plurality of R may be the same or different.
- the different Rs include, but are not limited to, those containing ethyleneoxy units and propyleneoxy units obtained by mixing and reacting ethylene oxide and propylene oxide. .
- the most preferred polyalkylene glycol ether of the above formula (1) is polyethylene glycol dimethyl ether in which the alkylene group (R) is an ethylene group and the ether groups (X and Y) at both ends are both methyl groups. More preferred are pentaethylene glycol dimethyl ether, hexaethylene glycol dimethyl ether, and heptaethylene glycol dimethyl ether.
- a high boiling organic solvent having a boiling point in the range of 220 to 500 ° C. at normal pressure a high boiling organic solvent having a lower solubility in GAO than the group (a) can be used.
- These high boiling point organic solvents have a dissolving power capable of dissolving the oligomer alone at a temperature at which the depolymerization reaction of GAO occurs at about 1/3 or less, in most cases 1 in comparison with the group solvent. It is a high-boiling organic solvent having a small dissolving power of / 5 or less, often 1/10 or less. These high-boiling organic solvents having a low dissolving power are referred to as (b) group solvents. These (b) group solvents are preferably used in combination with the (a) group solvent or in combination with a solubilizer described later.
- the polyalkylene glycol ether belonging to the group solvent is represented by the formula (1) X—O — (— R—O—) p —Y (1)
- the polyalkylene glycol ether represented by these may be sufficient.
- the ether groups (X and Y) at both ends are each independently a methyl group, an alkyl group having 2 to 20 carbon atoms or an aryl group, but more preferably both X and Y are carbon atoms.
- the alkyl group having a number of 1 to 18 and the total number of carbon atoms of the alkyl group contained in the ether groups at both ends is preferably 11 to 28, more preferably 11 to 24. Can do.
- alkyl groups include those formed by combining methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl, decyl, dodecyl, octadecyl, and the like. These alkyl groups may be linear or branched.
- the property of the polyalkylene glycol ether belonging to the group solvent also varies depending on the number of repetitions p of the alkyleneoxy unit (—R—O—) in the formula (1).
- the polyalkylene glycol ether exhibiting group properties preferably has a repeating number p in the range of 2 to 10, more preferably 2 to 8.
- polyalkylene glycol ethers belonging to group (b) group solvents include ethylene glycol methyl octadecyl ether, dipropylene glycol dioctyl ether, triethylene glycol butyl octyl ether, tetraethylene glycol butyl dodecyl ether, and the like.
- the aromatic carboxylic acid ester, the aliphatic carboxylic acid ester, the aromatic halide, and the aromatic phosphoric acid ester have GAO solubility, chemical stability, thermal stability, etc.
- the aromatic carboxylic acid ester for example, phthalic acid esters such as benzyl butyl phthalate, dibutyl phthalate, diamyl phthalate and dipropyl phthalate; and benzoic acid esters such as benzyl benzoate are preferable.
- the aliphatic carboxylic acid ester include adipic acid esters such as octyl adipate and sebacic acid esters such as dibutyl sebacate.
- the aromatic phosphate ester include tricresyl phosphate.
- the solvent of the group (b) may only partially dissolve the oligomer when the concentration of the oligomer is high at the temperature at which the GAO depolymerization reaction occurs.
- many of the solvents in group (b) are inexpensive and many can give glycolide in a relatively high yield if the solubility in oligomers is increased. Therefore, the solubility of GAO in the (b) group solvent is generally increased by using a solubilizer described later in combination.
- Solubilizer In the method for producing glycolide by depolymerizing the GAO of the present invention, it may be used to improve the solubility characteristics (solubility and / or dissolution rate) of GAO in the high-boiling organic solvent.
- the solubilizer can be used with a high boiling organic solvent or alone. That is, the GAO composition may be a GAO composition containing a solubilizer.
- the solubilizer used in the present invention is preferably a compound satisfying any one or more of the following requirements.
- the compound is compatible or soluble in the high boiling point organic solvent.
- Any compound that is compatible or soluble in the high-boiling organic solvent preferably used in the present invention may be liquid or solid at room temperature.
- solubilizer when used together with a high boiling organic solvent, if a compound having a boiling point at normal pressure higher than the boiling point at normal pressure of the high boiling organic solvent is used, the solubilizer is combined with glycolide and the high boiling organic solvent. It may be desirable because it does not distill or the amount of distillate is very low. In this case, for example, a compound having a boiling point of 500 ° C. or higher at normal pressure (including a compound whose boiling point at normal pressure cannot be confirmed) can be used as a solubilizer.
- a compound having a functional group such as an OH group, a COOH group, or a CONH group.
- a compound having a higher affinity with GAO than the high boiling organic solvent (iv) A compound having a higher affinity with GAO than the high boiling organic solvent.
- the affinity between the solubilizer and GAO can be confirmed by the following method. That is, a) A mixture of GAO and a high-boiling organic solvent is heated to a temperature of 230 to 280 ° C. to form a uniform solution phase, and b) GAO is further added to the mixture so that the concentration of the mixture becomes uniform. Increase until no solution phase is formed, and c) add solubilizer and observe visually whether a homogeneous solution phase is formed again.
- solubilizers that can be used in the present invention include monohydric or dihydric or higher polyhydric alcohols (may be partially esterified products and partially etherified products of polyhydric alcohols), phenols, Examples thereof include monovalent or divalent or higher polyvalent aliphatic carboxylic acids, aliphatic amides of aliphatic carboxylic acids and amines, aliphatic imides, and polyalkylene glycol ethers having a molecular weight of more than 450. These can be used alone or in combination of two or more.
- monohydric or dihydric or higher polyhydric alcohols are particularly effective as solubilizers.
- a monohydric or dihydric or higher polyhydric alcohol having a boiling point of 190 ° C. or higher at normal pressure can be preferably used.
- the boiling point of the monohydric or dihydric or higher polyhydric alcohol used as the solubilizer at normal pressure is more preferably 200 ° C. or higher, still more preferably 230 ° C. or higher, and particularly preferably 250 ° C. or higher.
- aliphatic alcohols such as decanol, tridecanol, decanediol, ethylene glycol, propylene glycol, and glycerin
- aromatic alcohols such as naphthyl alcohol
- polyalkylene glycol polyalkylene glycol monoether
- a preferable solubilizer is polyalkylene glycol or polyalkylene glycol monoether.
- the polyalkylene glycol As the polyalkylene glycol, the formula (2) HO — (— R 1 —O) q —H (2) (Wherein R 1 represents a methylene group or a linear or branched alkylene group having 2 to 8 carbon atoms, q represents an integer of 1 or more, and when q is 2 or more, a plurality of R 1 are Each may be the same or different.)
- the polyalkylene glycol represented by these is preferable.
- Specific examples of the polyalkylene glycol include polyethylene glycol, polypropylene glycol, polybutylene glycol and the like. These can be used alone or in combination of two or more.
- the polyalkylene glycol monoether is represented by the formula (3) HO — (— R 2 —O) r —X 1 (3) (Wherein R 2 represents a methylene group or a linear or branched alkylene group having 2 to 8 carbon atoms, X 1 represents a hydrocarbon group, r represents an integer of 1 or more, and r is 2 or more) In this case, the plurality of R 2 may be the same or different.)
- the polyalkylene glycol monoether represented by these is preferable.
- polyalkylene glycol monoether examples include polyethylene glycol monomethyl ether, polyethylene glycol monopropyl ether, polyethylene glycol monobutyl ether, polyethylene glycol monohexyl ether, polyethylene glycol monooctyl ether, polyethylene glycol monodecyl ether, polyethylene glycol monolauryl ether.
- Polyethylene glycol monoether such as polypropylene glycol monoether in which ethyleneoxy group is replaced with propyleneoxy group in the polyethylene glycol monoether; polybutylene glycol monoether in which ethyleneoxy group is replaced with butyleneoxy group in the polyethylene glycol monoether Ether; Other polyalkylene Glycol monomethyl ether; and the like.
- the polyethylene glycol monoether preferably has an alkyl group having 1 to 18 carbon atoms as its ether group. These can be used alone or in combination of two or more.
- polyalkylene glycol or polyalkylene glycol monoether When polyalkylene glycol or polyalkylene glycol monoether is used as a solubilizer, these compounds hardly distill from the depolymerization reaction system because of their high boiling point. Moreover, since polyalkylene glycol and polyalkylene glycol monoether have high solubility of GAO, when these are used as solubilizers, the depolymerization reaction of GAO may proceed rapidly. Further, when polyalkylene glycol monoether is used as a solubilizing agent, the cleaning effect on the can wall (reaction vessel inner wall) and the distillation line is particularly excellent.
- a non-basic compound (excluding monohydric or dihydric or higher polyhydric alcohols) having a boiling point of 190 ° C. or higher at normal pressure can be used as a solubilizer.
- solubilizers include, as described above, phenols, monovalent or divalent or higher polyvalent aliphatic carboxylic acids, aliphatic amides of aliphatic carboxylic acids and amines, and aliphatic imides.
- polyalkylene glycol ethers having a molecular weight exceeding 450, and a phenol compound having a boiling point of 230 ° C. or higher at normal pressure can be preferably used.
- solubilizer when a compound having a boiling point in the range of 220 to 500 ° C. is used as the solubilizer, the solubilizer is added to the high boiling organic solvent having a boiling point in the range of 220 to 500 ° C. at normal pressure. Is also equivalent.
- a polyalkylene glycol ether having a boiling point of 500 ° C. or higher as the solubilizer can be used.
- it has a higher affinity with GAO than a polyalkylene glycol ether preferably used as a high-boiling organic solvent having a boiling point in the range of 220 to 500 ° C., and has a boiling point exceeding 500 ° C. at normal pressure.
- high molecular weight polyalkylene glycol ether can be used together as a solubilizer.
- polyalkylene glycol ethers having a boiling point exceeding 500 ° C. suitable as a solubilizer include polyethylene glycol dimethyl ether # 500 (number average molecular weight 500), polyethylene glycol dimethyl ether # 2000 (number average molecular weight 2,000). Etc.
- These polyalkylene glycol ethers as solubilizers are high-boiling organics having a boiling point at atmospheric pressure of 220 to 500 ° C. preferably used in the present invention in that the boiling point at atmospheric pressure exceeds 500 ° C. It can be distinguished from polyalkylene glycol ether which is a solvent.
- solubilizer acts on the end of GAO, and GAO is easily dissolved in polyalkylene glycol ether, which is a high-boiling organic solvent having a boiling point in the range of 220 to 500 ° C. at normal pressure.
- the solubilizer can be used alone as the high boiling organic solvent itself having a boiling point in the range of 220 to 500 ° C. at normal pressure. . Since the solubilizer has a high affinity for GAO, there may be an effect that the depolymerization reaction of GAO can be started under relatively mild conditions.
- a solubilizer that can be used alone as a high-boiling organic solvent itself having a boiling point in the range of 220 to 500 ° C. a polyalkylene glycol monoether (with a boiling point of 220 to 500 ° C. at normal pressure) is used.
- a certain boiling point is measured.
- phenolic compounds Specifically, polyethylene glycol monomethyl ether and polyethylene glycol monooctyl ether can be preferably used as the polyalkylene glycol monoether, and 4- ⁇ -cumylphenol can be preferably used as the phenol.
- the solubilizer when a solubilizer is used, the solubilizer is usually 0.1 to 500 parts by weight, preferably 1 part per 100 parts by weight of GAO. It is used in a proportion of ⁇ 300 parts by mass, more preferably 5 to 250 parts by mass. If the use ratio of the solubilizer is too small, the solubility improving effect by the solubilizer cannot be sufficiently obtained. If the proportion of solubilizer used is too large, it will be costly to recover the solubilizer and is not economical.
- the GAO composition particularly comprises GAO and a high-boiling organic solvent having a boiling point in the range of 220 to 500 ° C. at normal pressure.
- a catalyst for depolymerization for example, a tin compound, an antimony compound, etc.
- the catalyst may be harmful.
- a catalyst can be used as long as the present invention is not essentially impaired.
- the method for producing glycolide by depolymerizing the GAO of the present invention comprises the following steps (1) to (5): Step (1) A step of supplying a GAO composition to a reaction vessel and heating to a temperature at which a depolymerization reaction of the GAO occurs under normal pressure or reduced pressure. Step (2) Further, heating is continued to depolymerize GAO to produce glycolide, Step (3) a step of distilling the produced glycolide from the reaction vessel, Step (4) Introducing distillate into a rectifier and rectifying by countercurrent contact of gas and liquid, and Step (5) A method for producing glycolide comprising a step of recovering glycolide.
- the step (1) comprises GAO and a high-boiling organic solvent having a boiling point in the range of 220 to 500 ° C. at normal pressure.
- This is a process for producing glycolide as described above, which is a step of heating the GAO composition contained to a temperature at which a depolymerization reaction of GAO occurs under normal pressure or reduced pressure.
- the method for producing glycolide by depolymerizing the GAO of the present invention preferably comprises the following steps (1 ′) to (5): Step (1 ′) GAO composition containing GAO and a high boiling point organic solvent having a boiling point in the range of 220 to 500 ° C.
- Step (2) is supplied to the reaction vessel, and depolymerization of GAO under normal pressure or reduced pressure. Heating to a temperature at which reaction occurs, Step (2) Further, heating is continued to depolymerize GAO to produce glycolide, Step (3) a step of distilling the produced glycolide from the reaction vessel, Step (4) Introducing distillate into a rectifier and rectifying by countercurrent contact of gas and liquid, and Step (5) A method for producing glycolide comprising a step of recovering glycolide.
- the step (3) is a step of distilling the produced glycolide together with the high-boiling organic solvent from the reaction vessel.
- This is a method for producing glycolide. That is, the method for producing glycolide by depolymerizing the GAO of the present invention preferably comprises the following (1 ′) to (5): Step (1 ′) GAO composition containing GAO and a high boiling point organic solvent having a boiling point in the range of 220 to 500 ° C. is supplied to the reaction vessel, and depolymerization of GAO under normal pressure or reduced pressure.
- Step (2) Heating to a temperature at which reaction occurs, Step (2) Further, heating is continued to depolymerize GAO to produce glycolide, Step (3 ′) Step of distilling the produced glycolide together with the high-boiling organic solvent from the reaction vessel Step (4) Step of introducing the distillate into a rectifier and rectifying by countercurrent contact of gas and liquid, and , Step (5) A method for producing glycolide comprising a step of recovering glycolide.
- the glycolide production method of the present invention can be carried out by using the glycolide production apparatus of the present invention, which is provided with a reaction vessel and a rectifier.
- the GAO composition in the method for producing glycolide by depolymerizing GAO of the present invention means a composition containing GAO as an essential component. Therefore, the GAO composition contains a composition consisting essentially of only GAO and GAO and other components such as a high-boiling organic solvent and solubilizer having a boiling point in the range of 220 to 500 ° C. at normal pressure. Means both the composition and the composition. Accordingly, the GAO composition includes a GAO composition that does not contain the above-described high boiling point organic solvent. In addition, the composition which consists only of GAO includes the composition containing GAO, an impurity, etc.
- the GAO composition in the present invention typically includes a GAO composition having the following specific composition.
- GAO composition substantially consisting of only GAO By the method for producing glycolide having a rectification step as described later, glycolide having a low free acid concentration and high purity can be stably obtained.
- GAO composition containing GAO and a high-boiling organic solvent having a boiling point in the range of 220 to 500 ° C. under normal pressure By the method for producing glycolide comprising a rectification step as described later, the rectification step and thereafter In this recovery step, the glycolide-containing mixture adheres to the inner wall of the line, making it impossible to continue the production of glycolide over a long period of time, and the amount of recovered glycolide is reduced. An increase in loss can be prevented.
- the depolymerization reaction temperature of GAO can be set high, so that the production rate of glycolide can be increased, and the distilled glycolide can be removed by distillation.
- group solvents (high boiling point organic solvents) are particularly preferred from the viewpoints of solubility in GAO, chemical stability, thermal stability, etc., and form a substantially uniform liquid phase with the GAO melt phase. Therefore, as described below, glycolide having a low free acid concentration and high purity can be stably obtained over a long period of time by a glycolide production method including a rectification step.
- GAO composition containing GAO and the above-mentioned group (b) solvent (high boiling point organic solvent): belonging to the high boiling point organic solvent having a boiling point in the range of 220 to 500 ° C.
- the group solvent is a high-boiling organic solvent having a lower solubility in GAO than the solvent in group (a), but many of them are inexpensive, and if the solubility in GAO is increased, glycolide is relatively high yielded. It can be expected to be obtained at a low rate and with a low free acid concentration.
- GAO GAO composition containing the solvent of group (a) and the solvent of group (b): Soluble in GAO while using the solvent of group (b), many of which are inexpensive And can form a substantially uniform liquid phase with the melt phase of GAO, so that the glycolide having a low free acid concentration and high purity can be obtained by the glycolide production method including a rectification step as described later. Can be stably obtained over a long period of time.
- GAO and GAO composition containing the solubilizing agent Since the solubilizing agent has high affinity for GAO, the depolymerization reaction of GAO can be initiated under relatively mild conditions, and GAO A substantially homogeneous liquid phase can be formed with this melt phase, and an excellent cleaning effect on the can wall (reaction vessel inner wall) and the distillation line can be expected.
- the solubilizer can be used with a high boiling organic solvent having a boiling point in the range of 220 to 500 ° C., but can also be used alone or as the high boiling organic solvent itself. It can also be used alone.
- GAO composition containing GAO, the above-mentioned solubilizer and a high-boiling organic solvent having a boiling point in the range of 220 to 500 ° C. at normal pressure By using a solubilizer having high solubility of GAO in combination A substantially homogeneous liquid phase can be formed with the GAO melt phase, the GAO depolymerization reaction proceeds rapidly, and the cleaning effect on the can wall (reaction vessel inner wall) and the distillation line is improved. The effect can be expected.
- GAO, GAO composition containing solvent of group (a) and solubilizing agent By using together a solubilizing agent having high solubility of GAO, it is substantially different from the melt phase of GAO.
- GAO depolymerization reaction can proceed rapidly, and effects such as an improved cleaning effect on the can wall (reaction vessel inner wall) and the distillation line can be expected.
- GAO, GAO composition containing the solvent of the group (b) and the solubilizing agent GAO may be highly soluble while using the solvent of the group (b), which is often inexpensive.
- the solubilizer in combination, the GAO depolymerization reaction proceeds rapidly, and effects such as improvement of the cleaning effect on the can wall (reaction vessel inner wall) and the distillation line can be expected.
- GAO has extremely high solubility and substantially equal to the melt phase of GAO. A uniform liquid phase can be formed, the depolymerization reaction of GAO proceeds rapidly, and the cleaning effect on the can wall (reaction vessel inner wall) and the distillation line can be expected, the free acid concentration is small, and the purity is low High glycolide can be obtained stably over a long period of time.
- a GAO composition preferably a GAO composition containing GAO and a high-boiling organic solvent having a boiling point in the range of 220 to 500 ° C. at normal pressure is supplied to a reaction vessel.
- the temperature at which depolymerization of GAO occurs after heating for dehydration as necessary under normal pressure or reduced pressure that is, usually 180 to 320 ° C., preferably 190 to 310 ° C., more preferably 200 ° C. It is heated to a temperature of about 300 ° C., particularly preferably about 210 to 290 ° C.
- the heating step is usually carried out under normal pressure, but it is preferably carried out in an inert gas atmosphere such as nitrogen gas. When decompression is carried out, it is 0.1 to 90 kPa, preferably 0.5 to 50 kPa, more A range of 1 to 30 kPa is preferable.
- the GAO forms a melt phase or a solution phase in the heating process.
- the GAO composition is preferably a GAO composition containing GAO and a high-boiling organic solvent having a boiling point in the range of 220 to 500 ° C., since the generation of glycolide and the volatilization rate can be increased.
- a high-boiling organic solvent a compound having high thermal stability is more preferable, and as described later, a high-boiling organic solvent capable of forming a GAO solution phase in the heating step is particularly preferable.
- GAO is melted or in a solid state, if necessary, pulverized to an appropriate particle size and then subjected to a depolymerization reaction.
- a reaction vessel such as a four-necked flask
- a high-boiling organic solvent having a boiling point in the range of 220 to 500 ° C. at normal pressure is charged into the reaction vessel together with the GAO or after the GAO is charged, and the GAO, the high-boiling organic solvent, A GAO composition containing is obtained.
- a solubilizer may be added to the reaction vessel as necessary.
- a solubilizer can also be used as the high boiling organic solvent itself.
- a heater (such as a current heating device) is installed around the reaction vessel.
- the temperature of the reaction vessel and the GAO composition in the reaction vessel can be adjusted by adjusting the heating current.
- An apparatus for distilling the distillate component from the depolymerization reaction system is connected to the reaction vessel, and a rectifier may be connected to the reaction vessel and disposed as described later.
- the heating step when a GAO composition containing a high-boiling organic solvent having a boiling point of 220 to 500 ° C. at normal pressure is used, the high-boiling organic solvent is used as the high-boiling organic solvent in the GAO melt phase.
- all or most of the GAO is dissolved in the high-boiling organic solvent, and a solution phase of GAO is substantially obtained.
- the “residual ratio of the melt phase” is the temperature at which depolymerization occurs by adding GAO F (g) in a solvent that does not substantially dissolve GAO, such as liquid paraffin.
- the volume of the GAO melt phase formed at this time is a (ml), and GAO F (g) is heated to a temperature at which depolymerization occurs in a solvent for which the residual ratio of the melt phase is to be measured.
- the volume of the melt phase is b (ml)
- the ratio of b / a is expressed.
- the residual ratio of the melt phase can be measured for the combination of the high-boiling organic solvent and the solubilizer.
- the residual ratio of the GAO melt phase is preferably 0.3 or less, more preferably 0.1 or less, and most preferably substantially zero.
- a GAO composition preferably a GAO composition containing GAO and a high-boiling organic solvent having a boiling point in the range of 220 to 500 ° C. at normal pressure, is further heated to depolymerize GAO.
- a step of producing glycolide is performed.
- the temperature at which the glycolide production step is performed may be the same as or different from the temperature at which the heating step is performed. That is, the temperature is preferably about 180 to 320 ° C., more preferably about 200 to 290 ° C., and particularly preferably about 210 to 280 ° C.
- Depressurization of the reaction vessel is preferable because the depolymerization reaction of GAO can be performed without increasing the depolymerization temperature, and the generation and volatilization rate of glycolide can be increased. Since the GAO depolymerization reaction is a reversible reaction, the GAO depolymerization reaction proceeds efficiently by distilling off glycolide from the liquid phase.
- the pressure at which the GAO depolymerization reaction is carried out is 0.1 to 90 kPa, preferably 0.3 to 50 kPa, more preferably 0.5 to 30 kPa, and even more preferably 0.7 to 10 kPa. That's fine.
- the depolymerization reaction it is preferable to perform the depolymerization reaction at a temperature of 180 to 320 ° C. and a pressure of 0.1 to 90 kPa.
- the pressure in the depolymerization reaction system it is preferable to perform the depolymerization reaction at a temperature of 180 to 320 ° C. and a pressure of 0.1 to 90 kPa.
- the temperature at which the glycolide production step and the rectification step described below can be performed can be lowered, thereby reducing solvent loss and increasing the solvent recovery rate.
- Even if the pressure of the depolymerization reaction system is less than 0.1 kPa, the effect of improving the efficiency in the glycolide production step does not increase, while the device design and maintenance costs tend to increase rapidly.
- the glycolide production method of the present invention performs a step (distillation step) of distilling glycolide produced in the glycolide production step from a reaction vessel or the like.
- the reaction vessel is connected to a device for distilling the distillate component from the depolymerization reaction system, and even if a rectifier for performing rectification is connected and arranged.
- a single tube such as a glass tube including a cooler
- simple distillation may be connected.
- the distillation step converts the glycolide produced in the glycolide production step to the high-boiling glycolide.
- glycolide or other low-intensity is added to the inner wall surface of the reaction vessel, the inner surface of the rectifier or single tube, and the inner surface of the recovery line in the recovery step described later. It is preferable because it can prevent the boiling component from adhering and accumulating.
- the distillate containing glycolide distilled off from the reaction vessel in the above-described distillation step preferably a distillate containing glycolide and the high-boiling organic solvent is purified. It is characterized in that it is provided with a process (rectification process) for introducing into a distillation apparatus and performing rectification by countercurrent contact of gas and liquid.
- Rectification is an operation in which purification and separation are performed by repeating gas-liquid countercurrent contact in which a liquid flow generated by condensation of a gas and a newly supplied gas flow come into contact with each other. That is, rectification is distinguished from distillation, in which the condensed liquid is repeatedly refluxed, simply condensing by cooling the supplied gas to obtain a liquid, and thus distillation. This is a different operation.
- a rectifier As a rectifier used for carrying out a rectification step on a distillate containing glycolide, preferably a distillate containing glycolide and the high boiling organic solvent, a rectifier includes a bubble bell, a valve type, Arrange multiple shelves of various types such as perforated plate, grid, slit type, and net type in the vertical direction, and make gas-liquid contact by inserting the gas coming from the bottom as bubbles into the liquid accumulated on the shelf
- a shelf tower that concentrates the desired components sequentially from the bottom to the top, a ring shape, a saddle shape, a corrugated plate shape, On the surface of the tower-like material filled with various types of packing materials such as plant pin plate shape, wire bundle shape, winding shape, etc., gas-liquid contact is made between the descending liquid and the ascending gas, and the gas at the position of each packing.
- Rectification column packed tower or the like is known to perform minute concentrated.
- any rectifier such as the rectification column can be used to carry out a rectification step in which the produced glycolide is rectified by gas-liquid countercurrent contact.
- the distillate which is a mixture of the produced glycolide and various volatilizable components, is introduced into the rectifier and the rectification process.
- a gas-liquid equilibrium state is obtained with a different composition at each position of a rectifier, for example, a rectifying column.
- the concentration of the glycolide as a target product that is, the purity of glycolide is maximized at a predetermined position of the rectifier, for example, at the top of the rectification column.
- the supply rate from the reaction vessel is adjusted by adjusting the temperature of each part and combining the temperature and pressure of the reaction vessel. Since the depolymerization reaction of GAO is a reversible reaction, the depolymerization reaction of GAO proceeds efficiently by distilling off glycolide from the liquid phase. Note that the volatile component having a low boiling point supplied from the reaction vessel is released out of the system in the initial stage of the rectification step.
- the rectification step that is, the step (4) of introducing the distillate into the rectifier and performing rectification by gas-liquid countercurrent contact is performed by a rectifier arranged in connection with the reaction vessel. It is preferable to carry out from the viewpoint of utilization efficiency of heat energy used for performing the depolymerization reaction of GAO and simplification of equipment.
- the glycolide produced in the glycolide production step is distilled out of the reaction vessel by distillation and once collected, and if necessary, a predetermined amount of distillate is collected after the distillation.
- the rectification step can be performed by introducing the rectifier into a separately arranged rectifier and performing rectification.
- this method is not necessarily advantageous from the viewpoints of the use efficiency of the heat energy used for performing the GAO depolymerization reaction and the necessity of separately disposing distillation equipment.
- the GAO composition contains GAO containing GAO and a high-boiling organic solvent having a boiling point in the range of 220 to 500 ° C. at normal pressure, or solubilization added as necessary.
- the rectification step is a step of rectifying the produced glycolide by gas-liquid countercurrent contact in the presence of the high-boiling organic solvent. From the viewpoint of the purity of the glycolide obtained and the thermal energy efficiency.
- glycolide produced in the glycolide production step and the high-boiling organic solvent are both distilled off from the reaction vessel in a gaseous state, introduced into a rectifier, and a rectification step is performed.
- the flow of gas newly supplied from the reaction vessel and the flow of liquid condensed in the rectifier are repeatedly counter-current contacted so that low-boiling compounds, etc. Impurities are dissipated and removed early, and the concentration and purity of glycolide gradually increase.
- polymerizable components such as glycolic acid are polymerized in the rectification process to form oligomers, and the oligomers are depolymerized to produce glycolide, so that the concentration and purity of glycolide are reduced. It is assumed that it will rise.
- most of the high-boiling organic solvents are separated from glycolide in the rectification step, refluxed to the GAO composition in the reaction vessel, and used for the heating step.
- the rectification step by adjusting so that only glycolide is distilled off and the high boiling organic solvent is not distilled, all the high boiling organic solvent is refluxed to the reaction vessel. Then, thermal energy efficiency can be improved and manufacturing costs can be reduced.
- the manufacturing method of glycolide of this invention performs the process (recovery process) which collect
- glycolide or a distillate from a rectifier such as a rectification column containing glycolide is cooled, and phase separation such as filtration, centrifugal sedimentation, decantation, and liquid-liquid separation is performed as necessary.
- a recovery operation for purification by a conventional method such as washing or extraction using a poor solvent such as cyclohexane or ether, crystallization or recrystallization using ethyl acetate or the like may be added.
- a recovery operation such as crystallization is unnecessary or even if it is carried out, it is extremely easy and simple.
- the high-boiling organic solvent and / or solubilizing agent separated in the rectification step and / or the recovery step and having a boiling point of 220 to 500 ° C. at normal pressure is refluxed to the reaction vessel. May be.
- the high-boiling organic solvent and / or the solubilizer to be used as needed is returned to the reaction vessel, returned to the depolymerization reaction system, and subjected to a heating step, whereby the high-boiling organic solvent is reused. Only a small amount of new high-boiling organic solvents that need to be added.
- the high-boiling organic solvent and a solubilizing agent to be added as necessary are contained in a mixture containing glycolide distilled from the rectification step, the high-boiling organic solvent and / or used as necessary. It is preferable that the solubilizer is separated from glycolide, refluxed to the reaction vessel to which the GAO composition is supplied, and subjected to the heating step. Since the high-boiling organic solvent and / or solubilizer is chemically and thermally stable in the depolymerization reaction, a new high-boiling organic solvent and / or a new high-boiling organic solvent that needs to be added for reuse. Only a small amount of solubilizer is required.
- the high boiling point organic solvent and / or the solubilizer is excellent in thermal stability
- in the recovery step of recovering glycolide from the distillate for example, when the distillate is cooled to recover glycolide.
- glycolide and high-boiling organics are cooled by a condenser (condenser) containing a glycolide distilled from the rectification step and a high-boiling organic solvent and / or a solubilizing agent used as necessary.
- the solvent and / or the solubilizer are phase-separated while in the liquid state, and the glycolide phase is separated and recovered.
- the distillate is phase-separated, usually, a glycolide phase is formed in the lower layer, and the upper layer is a solvent phase (high-boiling organic solvent and / or solubilizer phase).
- the lower glycolide phase can be separated and recovered in a liquid state.
- the cooling temperature is usually controlled to 85 to 180 ° C., preferably 85 to 150 ° C., more preferably 85 to 120 ° C. If the cooling temperature is too high, side reactions such as ring-opening reactions and polymerization reactions are likely to occur in the glycolide phase during the separation operation. If the cooling temperature is too low, it will be difficult to separate the phases while still in a liquid state.
- glycolide distilled together with the solvent passes through the upper solvent phase (high-boiling organic solvent and / or solubilizer phase) as droplets. And condenses in the underlying glycolide phase.
- the separated glycolide phase is further cooled and recovered, and purified as necessary. According to this method, it is not necessary to separate a large amount of solvent (high boiling point organic solvent and / or solubilizing agent) from the recovered glycolide, and the separation operation of the solvent and glycolide is simplified.
- solvent high boiling point organic solvent and / or solubilizing agent
- the high-boiling organic solvent and / or the solubilizer phase can be separated from the distillate obtained by phase separation and returned to the depolymerization reaction system. According to this method, it is not necessary to recover a large amount of solvent (high boiling point organic solvent and / or solubilizing agent), and it is not necessary to prepare a solvent exceeding the amount determined by the volume of the reaction vessel. Therefore, this method can minimize the loss of the solvent.
- Glycolide Glycolide produced by the method for producing glycolide of the present invention is glycolide having a high purity, and is a highly stable glycolide having a free acid concentration of 0.6 mmol / g or less.
- the glycolide obtained by the method for producing glycolide of the present invention has a purity of 10% by mass or more, preferably 15% by mass or more, more preferably 40% by mass or more, still more preferably 60% by mass or more, and particularly preferably 70% by mass or more.
- the most preferable is 80% by mass or more. If the purity of the obtained glycolide is 10% by mass or more, purification such as crystallization and recrystallization is easy, and purification may be unnecessary depending on the intended use or the purity of glycolide.
- the upper limit of the purity of glycolide is 100% by mass, but is usually 99.99% by mass and in many cases about 99.95% by mass.
- the purity of glycolide produced by the depolymerization reaction is measured by gas chromatography (GC). 200 mg of a glycolide sample and 40 mg of p-chlorobenzophenone (manufactured by Tokyo Chemical Industry Co., Ltd.) as an internal standard substance are dissolved in 10 ml of acetone. 2 ⁇ l of the lysate is collected, injected into a gas chromatography apparatus, the amount of glycolide is measured, and a calibration curve prepared in advance using glycolide and p-chlorobenzophenone as an internal standard substance is used. Determine the purity of glycolide.
- the glycolide produced by the glycolide production method of the present invention that is, glycolide produced by the depolymerization reaction, has a free acid concentration of 0.6 mmol / g or less, preferably 0.55 mmol / g or less, more preferably 0.5 mmol / g or less, Preferably, it is 0.45 mmol / g or less, particularly preferably 0.4 mmol / g or less, most preferably 0.35 mmol / g or less, and particularly preferably 0.3 mmol / g or less. Was found to be obtained.
- the lower limit of the free acid concentration of glycolide produced by the method for producing glycolide of the present invention is 0 mmol / g because glycolide having the lowest free acid concentration is desirable, but usually 0.01 mmol / g or more, In the case of 0.03 mmol / g or more, there is no problem.
- the free acid concentration in glycolide is measured by the following method. That is, 30 mg of a glycolide sample is dissolved in a mixed solvent of 25 ml of acetone and 25 ml of methanol. A methanol solution containing sodium methoxide is titrated as a neutralizing solution to detect the neutralization point. From the detected neutralization point, the free acid concentration present in 1 g of glycolide sample is calculated as the number of mmols (unit: mmol / g).
- Method for Purifying Crude Glycolide The method for producing glycolide of the present invention can also be applied to a method for purifying crude glycolide. That is, according to the present invention, the following steps (i) to (iii): Step (i) supplying the crude glycolide composition to the reaction vessel and heating it under normal pressure or reduced pressure to distill glycolide. Step (ii) introducing the distillate into a rectifier and rectifying it by gas-liquid countercurrent contact; and Provided is a method for purifying crude glycolide, comprising the step (iii) of recovering glycolide.
- the crude glycolide composition in the method for purifying crude glycolide means a composition containing crude glycolide as an essential component. Therefore, the crude glycolide composition is a composition substantially consisting only of crude glycolide, that is, a crude glycolide composition containing glycolide and impurities, the crude glycolide, a high-boiling organic solvent, a solubilizing agent, and the like. Both crude glycolide compositions containing other ingredients are meant. In addition, what was mentioned previously can be used for other components, such as a high boiling point organic solvent and a solubilizer.
- the crude glycolide composition is a crude glycolide composition containing crude glycolide and a high-boiling organic solvent having a boiling point of 220 to 500 ° C. at normal pressure, and ,
- the said purification method of the crude glycolide which is the process by which the said process (i) distills glycolide with this high boiling point organic solvent is employable.
- purification method of the crude glycolide which is a crude glycolide composition in which a crude glycolide composition contains a solubilizer can be employ
- the glycolide contained in the crude glycolide composition is purified together with a high-boiling organic solvent and / or a solubilizing agent and purified to a low-impurity glycolide by rectification by gas-liquid countercurrent contact. Therefore, the recovered glycolide-containing distillate is cooled with a cooler to cause phase separation in a liquid state, and the purified glycolide layer and the high-boiling organic solvent and / or the solubilizer layer are separated. They can also be collected separately.
- the high-boiling organic solvent and / or solubilizing agent is chemically and thermally stable, the amount of the new high-boiling organic solvent and / or solubilizing agent to be added is extremely small when reused. Small amount is enough.
- the crude glycolide purification method of the present invention is easy to scale up, and a large amount of crude glycolide can be industrially purified.
- the high-boiling organic solvent and / or the solubilization preferably having a boiling point in the range of 220 to 500 ° C. at normal pressure separated in the step (ii) and / or step (iii).
- a method for purifying the crude glycolide is provided in which the agent is refluxed to the reaction vessel.
- the glycolide purified by the crude glycolide purification method of the present invention has a small or almost no impurity content.
- the ratio of glycolide to the total amount of glycolide and impurities can be 85% by mass or more, preferably 90% by mass or more, and more preferably 95% by mass.
- the ratio can be 99% by mass or more, ideally 100% by mass.
- the method for purifying crude glycolide of the present invention can be carried out using the apparatus for purifying crude glycolide of the present invention, which comprises a reaction vessel and a rectifier.
- the method for measuring the physical properties of glycolide is as follows.
- the free acid concentration in glycolide produced by the depolymerization reaction was measured by the following method. That is, 30 mg of glycolide sample was dissolved in a mixed solvent of 25 ml of acetone and 25 ml of methanol. A methanol solution containing sodium methoxide is titrated as a neutralizing solution to detect the neutralization point. From the detected neutralization point, the free acid concentration present in 1 g of glycolide sample was calculated as the number of mmols (unit: mmol / g).
- a four-necked flask having a volume of 500 ml was used as a reaction vessel, and a stirring blade, a thermometer, and a pressure measuring device were arranged thereon to obtain a depolymerization reaction device.
- a distillation line was connected to the top of the flask, and a vacuum line and a receiver were attached to the outlet of the distillation line.
- a mantle heater was used to heat the flask of the depolymerization reaction system.
- distillation line in the examples, a rectifier (a packed column or a plate column including a cooler) for performing rectification, and in a comparative example, a single tube for performing simple distillation ( Each glass tube containing a cooler was used.
- the distilling line was wrapped with a ribbon heater and glass wool insulation to prevent heat dissipation.
- Example 1 A GAO composition containing 150 g of GAO prepared in Reference Example 1 and 150 g of hexaethylene glycol dimethyl ether (the solvent of the group (a) having a boiling point of 356 ° C. at normal pressure) was put into a reaction vessel of a depolymerization reactor. The sample was heated to a temperature of 220 ° C. under a reduced pressure of 3.0 kPa under a nitrogen gas atmosphere (heating step). It was confirmed by visual observation that GAO was uniformly dissolved in the solvent, and there was no GAO melt phase and no phase separation. When the temperature was changed to 237 ° C.
- Example 2 As a rectifier, instead of the packed tower, a 12-stage plate tower (inner diameter 20 mm) was used, and the depolymerization reaction was started at a temperature of 239 ° C. and a pressure of 3.5 kPa. In the same manner as in Example 1, GAO was depolymerized. When distillation was continued for 300 minutes (5 hours), the rectification operation could be performed without any problem. The collected material collected in the receiver was collected and analyzed by GC. As a result, it was concentrated glycolide, the purity of glycolide was 97% by mass, and the free acid concentration in glycolide was 0.35 mmol / g. . The results are shown in Table 1.
- Example 3 As a rectifier, instead of a 12-stage plate tower (inner diameter 20 mm), a 7-stage plate tower (inner diameter 20 mm) was used, and the depolymerization reaction was started at a temperature of 243 ° C. and a pressure of 4 A GAO depolymerization reaction was carried out in the same manner as in Example 2 except that the pressure was 0.1 kPa. When distillation was continued for 300 minutes (5 hours), the rectification operation could be performed without any problem. The collected substance collected in the receiver was collected and analyzed by GC. As a result, it was concentrated glycolide, the purity of glycolide was 88% by mass, and the free acid concentration in glycolide was 0.37 mmol / g. . The results are shown in Table 1.
- Example 4 A GAO composition containing 150 g of GAO prepared in Reference Example 1 and 150 g of heptaethylene glycol dimethyl ether (the solvent of group (a) having a boiling point of 381 ° C. at normal pressure) was charged into a reaction vessel of a depolymerization reactor. And heated under a reduced pressure of 3.0 kPa under a nitrogen gas atmosphere to a temperature of 258 ° C. (it was visually confirmed that GAO was uniformly dissolved in the solvent and not phase-separated), and A GAO depolymerization reaction was carried out in the same manner as in Example 2 except that heating was continued while maintaining the reduced pressure condition and temperature.
- the solvent of group (a) having a boiling point of 381 ° C. at normal pressure was charged into a reaction vessel of a depolymerization reactor. And heated under a reduced pressure of 3.0 kPa under a nitrogen gas atmosphere to a temperature of 258 ° C. (it was visually confirmed that GAO was uniformly dissolved in the
- Example 5 Using the depolymerization reaction apparatus and rectifier (packed tower) used in Example 1, 150 g of GAO and pentaethylene glycol dimethyl ether prepared in Reference Example 1 (the group (a) having a boiling point of 319 ° C. at normal pressure) The GAO composition containing 150 g of the solvent was put into a reaction vessel of a depolymerization reactor and heated to a temperature of 220 ° C. under a reduced pressure of 5.0 kPa in a nitrogen gas atmosphere. It was visually confirmed that GAO was uniformly dissolved in the solvent and was not phase-separated. When the pressure was further reduced to 4.5 kPa and the temperature was changed to 217 ° C.
- Example 6 As a rectifier, instead of a packed tower ( ⁇ 28 mm x 480 mm), a rectifier (Dixon packing (1/8 in, manufactured by Toutokenji Co., Ltd.) on a glass column with an inner diameter of 20 mm laid on the bottom of a 1.5 mesh stainless steel wire mesh) A packed tower obtained by packing up to a packing height of 300 mm while vibrating. Hereinafter, it may be referred to as “packed tower ( ⁇ 20 mm ⁇ 300 mm)”. The depolymerization reaction of GAO was carried out in the same manner as in Example 5 except that the depolymerization reaction start condition was changed to a temperature of 218 ° C. and the heating was continued.
- Example 7 A GAO composition containing 150 g of GAO prepared in Reference Example 1 and 150 g of p-chlorobenzophenone (the above-mentioned group (a) solvent having a boiling point of 332 ° C. at normal pressure) is charged into a reaction vessel of a depolymerization reactor. The sample was heated to 227 ° C. under a reduced pressure of 6.0 kPa under a nitrogen gas atmosphere (it was visually confirmed that GAO was uniformly dissolved in the solvent and was not phase-separated). A GAO depolymerization reaction was performed in the same manner as in Example 1 except that heating was continued while maintaining the conditions and temperature.
- p-chlorobenzophenone the above-mentioned group (a) solvent having a boiling point of 332 ° C. at normal pressure
- Example 8 150 g of GAO prepared in Reference Example 1, triethylene glycol butyl octyl ether (solvent of group (b) having a boiling point of 354 ° C. at normal pressure) and polyethylene glycol monomethyl ether [Nippon Emulsifier Co., Ltd., MPG-130H2, normal pressure
- a depolymerization reaction apparatus comprising a GAO composition containing 150 g of a mixed solvent having a mass ratio of 1: 1 of a solubilizer as a mixture containing a component having a boiling point in the range of 220 to 500 ° C. in an amount of 25 mass% or more. And heated to 240 ° C.
- Example 9 A GAO composition containing 150 g of GAO prepared in Reference Example 1 and 150 g of 4- ⁇ -cumylphenol (a solubilizer having a boiling point of 335 ° C. at normal pressure) was charged into a reaction vessel of a depolymerization reactor, It was heated to a temperature of 230 ° C. under a reduced pressure of 3.5 kPa under a nitrogen gas atmosphere (it was visually confirmed that GAO was uniformly dissolved in a solvent and not phase-separated), reduced pressure conditions and A GAO depolymerization reaction was carried out in the same manner as in Example 1 except that the heating was continued while maintaining the temperature. When distillation was continued for 300 minutes (5 hours), the rectification operation could be performed without any problem.
- 4- ⁇ -cumylphenol a solubilizer having a boiling point of 335 ° C. at normal pressure
- the collected substance collected in the receiver was collected and analyzed by GC. As a result, it was concentrated glycolide, the purity of glycolide was 88% by mass, and the free acid concentration in glycolide was 0.20 mmol / g. .
- the results are shown in Table 1.
- Example 10 A GAO composition containing 150 g of GAO prepared in Reference Example 1 and 150 g of polyethylene glycol monomethyl ether (solubilizing agent) used in Example 8 was put into a reaction vessel of a depolymerization reactor, and under a nitrogen gas atmosphere, Under reduced pressure conditions of 1.0 kPa, heating to a temperature of 230 ° C. (it was visually confirmed that GAO was uniformly dissolved in the solvent and was not phase-separated) to start the depolymerization reaction, While maintaining the conditions, the GAO was depolymerized in the same manner as in Example 6 except that the depolymerization reaction was continued by heating while raising the temperature to 255 ° C.
- Step (1) A step of supplying a GAO composition to a reaction vessel and heating to a temperature at which a depolymerization reaction of the GAO occurs under normal pressure or reduced pressure.
- Step (2) Further, heating is continued to depolymerize GAO to produce glycolide
- Step (3) a step of distilling the produced glycolide from the reaction vessel
- Step (4) Introducing distillate into a rectifier and rectifying by countercurrent contact of gas and liquid, and Step (5)
- the glycolide production method of Examples 1 to 10 including the step of recovering glycolide, even if distillation is continued for 300 minutes (5 hours), the rectification operation can be performed without any problem, and the recovery is performed. It was found that glycolide having a high stability of 20 to 98% by mass and a low free acid concentration of 0.20 to 0.58 mmol / g and excellent stability can be obtained.
- the step (4) provided in the method for producing glycolide of the present invention (4) A rectifier for carrying out a step of introducing a distillate into a rectifier and performing rectification by countercurrent contact of gas and liquid. From the results of Examples 2 and 3 in which the number of shelves was changed, and Examples 5 and 6 in which the diameter and packing height of the packed tower were changed, the distillate in step (4) was selected by selecting a rectifier. It was found that the purity of glycolide obtained and the free acid concentration in glycolide can be adjusted by changing the embodiment of the step of introducing into a rectifier and performing rectification by countercurrent contact of gas and liquid.
- glycolide of Example 8 using a GAO composition containing a solubilizer together with a high-boiling organic solvent having a boiling point in the range of 220 to 500 ° C. as the GAO composition in step (1). From the method, it was found that by using a solubilizer in combination, the resulting glycolide has high purity and can reduce the free acid concentration therein.
- Example 11 A GAO composition consisting of 150 g of GAO prepared in Reference Example 1 (containing no high-boiling organic solvent and / or solubilizing agent) was put into a reaction vessel of a depolymerization reaction apparatus, and 1.0 kPa in a nitrogen gas atmosphere. When the depolymerization reaction was started by heating to a temperature of 235 ° C. under reduced pressure, the mixture containing glycolide began to distill from the reaction vessel into the rectification apparatus.
- Step (1) A step of supplying a GAO composition to a reaction vessel and heating to a temperature at which a depolymerization reaction of the GAO occurs under normal pressure or reduced pressure.
- Step (2) Further, heating is continued to depolymerize GAO to produce glycolide
- Step (3) a step of distilling the produced glycolide from the reaction vessel
- Step (4) Introducing distillate into a rectifier and rectifying by countercurrent contact of gas and liquid
- Step (5) A method for producing glycolide of Example 11, comprising a step of recovering glycolide, specifically, the GAO composition has a high boiling point organic solvent having a boiling point in the range of 220 to 500 ° C.
- glycolide containing no solubilizer, and a rectifier [packing tower ( ⁇ 20 mm ⁇ 300 mm)] as a distillation line connected to a reaction vessel for depolymerizing the GAO to produce glycolide
- a rectifier [packing tower ( ⁇ 20 mm ⁇ 300 mm)] as a distillation line connected to a reaction vessel for depolymerizing the GAO to produce glycolide
- the rectification was performed without any problems even if the distillation was continued for 210 minutes (3.5 hours). It was found that glycolide having a high stability and a high glycolide purity of 96% by mass and a low free acid concentration of 0.50 mmol / g could be obtained.
- Example 12 Purification method of crude glycolide 150 g of glycolide (purity 99.96% by mass or more), 15 g of glycolic acid (manufactured by Wako Pure Chemical Industries, Ltd., 071-01512) and 100 g of hexaethylene glycol dimethyl ether (high boiling point organic solvent having a boiling point of 356 ° C. at normal pressure) As a rectifier, a crude glycolide composition was prepared by putting it into a reaction vessel (a four-necked flask having a capacity of 500 ml) connected to the packed tower ( ⁇ 28 mm ⁇ 480 mm) used in Example 1.
- a reaction vessel a four-necked flask having a capacity of 500 ml
- the packed tower ⁇ 28 mm ⁇ 480 mm
- the glycolide concentration in the crude glycolide composition was 56.6% by mass, the solvent (hexaethylene glycol dimethyl ether) concentration was 37.7% by mass, and the free acid concentration was 0.74 mmol / g.
- the ratio of glycolide to the total of glycolide and impurities other than the solvent (equivalent to glycolic acid) was 90.9% by mass.
- a crude glycolide composition containing crude glycolide and a high-boiling organic solvent was heated to a temperature of 180 ° C. It was visually confirmed that the crude glycolide was uniformly dissolved in the solvent and not phase-separated.
- this crude glycolide composition was depressurized to 3.0 kPa while continuing to heat, glycolide and solvent co-distillation began.
- the cock of the distillation line at the upper part of the packed column was closed, and the total reflux operation was performed to stabilize the temperature of the rectifier. Thereafter, when the cock was opened, glycolide was distilled from the rectifier (packing tower) and collected in a receiver attached to the distillation line.
- the present invention relates to a method for producing glycolide by depolymerizing GAO, and includes the following steps (1) to (5): Step (1) A step of supplying a GAO composition to a reaction vessel and heating to a temperature at which a depolymerization reaction of the GAO occurs under normal pressure or reduced pressure. Step (2) Further, heating is continued to depolymerize GAO to produce glycolide, Step (3) a step of distilling the produced glycolide from the reaction vessel, Step (4) Introducing distillate into a rectifier and rectifying by countercurrent contact of gas and liquid, and Step (5)
- the glycolide production method comprising the step of recovering glycolide, the reaction can be continued over a long period without lowering the production efficiency, and efficiently and economically. Further, since a method for producing glycolide having high purity, reduced free acid concentration and excellent stability by depolymerizing GAO is provided, the industrial applicability is high.
- the present invention also provides the following steps (i) to (iii): Step (i) supplying the crude glycolide composition to the reaction vessel and heating it under normal pressure or reduced pressure to distill glycolide. Step (ii) introducing the distillate into a rectifier and rectifying it by gas-liquid countercurrent contact; and Step (iii) A crude glycolide purification method comprising a step of recovering glycolide to obtain glycolide having high yield, high purity, reduced free acid concentration, and excellent stability. Since a method for purifying crude glycolide that can be produced is provided, the industrial applicability is high.
- the present invention is a glycolide production apparatus or a crude glycolide purification apparatus characterized by comprising a reaction vessel and a rectifier, so that the reaction is continued for a long period without a decrease in production efficiency.
- a glycolide production apparatus or a crude glycolide purification apparatus capable of producing or purifying glycolide with high purity, reduced free acid concentration and excellent stability by depolymerizing GAO efficiently and economically Since it is provided, the industrial applicability is high.
Abstract
Description
(I)脂肪族ポリエステル(A)と下記式
X’-O-(-R’-O-)a-Y’
(式中、R’は、メチレン基または炭素数2~8の直鎖状または分岐状のアルキレン基を表し、X’は、炭化水素基を表し、Y’は、炭素数2~20のアルキル基またはアリール基を表し、aは、1以上の整数を表し、aが2以上の場合には、複数のR’は、それぞれ同一でも異なってもよい。)
で表され、かつ、230~450℃の沸点と150~450の分子量を有するポリアルキレングリコールエーテル(B)とを含む混合物を、常圧下または減圧下に、該脂肪族ポリエステル(A)の解重合が起こる温度に加熱し、
(II)該脂肪族ポリエステル(A)の融液相と該ポリアルキレングリコールエーテル(B)からなる液相とが実質的に均一な相を形成した溶液状態とし、
(III)該溶液状態で加熱を継続することにより、解重合により生成した環状エステルを該ポリアルキレングリコールエーテル(B)とともに留出させ、
(IV)留出物から環状エステルを回収する環状エステルの製造方法が開示されている。この方法によれば、解重合反応により生成した環状エステルを、該ポリアルキレングリコールエーテルとともに留出させた後、両者を液状のまま相分離させて、環状エステル相を分離回収し、一方、熱劣化していないポリアルキレングリコールエーテル相を解重合反応系に循環して再利用できる、という効果が奏される。また、特許文献5には、該方法を適用して、粗環状エステルを精製する方法も記載されている。
グリコリド中の遊離酸濃度は、以下の方法により測定する。すなわちグリコリド試料30mgを、25mlのアセトンと25mlのメタノールとの混合溶媒に溶解する。ナトリウムメトキシドを含有するメタノール溶液を中和液として滴定し、中和点を検出する。検出した中和点から、グリコリド試料1g中に存在する遊離酸濃度をmmol数(単位:mmol/g)として算出する。
グリコリドの残存率(質量分率)及びヘーズ値の経時変化の測定は、以下の方法で行った。すなわち、容積10mlのサンプル瓶に、グリコリド(純度99.96質量%以上)と所定量のグリコール酸とを加え、窒素を封入した後、温度110℃のオイルバスに浸漬して静置した。オイルバスへの静置開始から、所定の時間(試験開始後1.5時間、3.5時間及び5.5時間)が経過した時点で、サンプル瓶を室温まで冷やし、グリコリドと所定量のグリコール酸とからなる100mgの試料を採取し、それぞれの試料について、グリコリドの残存率、及び、ヘーズ値の測定を行い、それらの経時変化を求めた。
グリコリドの残存率は、以下の方法で行った。すなわち、前記の所定の時間が経過した時点において採取したグリコリドと所定量のグリコール酸とを含有する試料100mg、及び、内部標準物質としてのp-クロロベンゾフェノン(東京化成工業株式会社製)40mgを、アセトン10mlに溶解させた。次いで、その溶解液2μlを採取し、ガスクロマトグラフィー装置に注入して、グリコリド量の測定を行い、あらかじめ、グリコリドと内部標準物質であるp-クロロベンゾフェノンとを用いて作成した検量線を使用して、試料中に残存するグリコリドの純度を求めた。続いて、次式により、前記の所定の時間が経過した時点におけるグリコリドの残存率を算出した。
グリコリドの残存率(質量%)=(a/b)×100
a:試料中に残存ずるグリコリドの質量(g)
b:あらかじめサンプル瓶に加えたグリコリドの質量(g)
グリコリドのヘーズ値は、Water Analyzer 2000N(日本電色工業株式会社製)を使用して測定した。具体的には、前記のとおり採取したグリコリドと所定量のグリコール酸とを含有する試料100mgを、容積50mlの三角フラスコ中で超音波振動機を使用して、アセトン20mlに完全に溶解させる。分析用セルに溶解した試料を加えて、ヘーズ値(単位:%)の測定を行い、前記の所定の時間が経過した時点におけるヘーズ値とした。
工程(1)グリコール酸オリゴマー組成物を反応容器に供給して、常圧下または減圧下に、該グリコール酸オリゴマーの解重合反応が起る温度に加熱する工程、
工程(2)更に加熱を継続してグリコール酸オリゴマーを解重合反応させてグリコリドを生成させる工程、
工程(3)生成したグリコリドを反応容器から留出させる工程、
工程(4)留出物を精留器に導入して気液の向流接触により精留する工程、及び、
工程(5)グリコリドを回収する工程
を備えることを特徴とするグリコリドの製造方法が提供される。
X-O-(-R-O-)p-Y (1)
(式中、Rは、メチレン基または炭素数2~8の直鎖状または分岐状のアルキレン基を表し、X及びYは、それぞれ独立して、メチル基または炭素数2~20のアルキル基またはアリール基を表し、pは、1以上の整数を表し、pが2以上である場合には、複数のRは、それぞれ同一でも異なってもよい。)
で表される少なくとも一種のポリアルキレングリコールエーテルである前記のグリコリドの製造方法。
工程(i)粗グリコリド組成物を反応容器に供給し、常圧下または減圧下に加熱して、グリコリドを留出させる工程、
工程(ii)留出物を精留器に導入して気液の向流接触により精留する工程、及び、
工程(iii)グリコリドを回収する工程
を備えることを特徴とする粗グリコリドの精製方法が提供される。
前記の工程(i)が、グリコリドを該高沸点有機溶媒とともに留出させる工程である前記の粗グリコリドの精製方法。
工程(1)グリコール酸オリゴマー組成物を反応容器に供給して、常圧下または減圧下に、該グリコール酸オリゴマーの解重合反応が起る温度に加熱する工程、
工程(2)更に加熱を継続してグリコール酸オリゴマーを解重合反応させてグリコリドを生成させる工程、
工程(3)生成したグリコリドを反応容器から留出させる工程、
工程(4)留出物を精留器に導入して気液の向流接触により精留する工程、及び、
工程(5)グリコリドを回収する工程
を備えることを特徴とするグリコリドの製造方法であることによって、グリコリド留出物中の遊離酸の濃度を低減できるので、効率性、経済性及びロングラン性に優れる、高純度のグリコリドを製造する方法を提供することができるという効果が奏される。
前記のグリコール酸オリゴマー組成物が、グリコール酸オリゴマーと常圧における沸点が220~500℃の範囲である高沸点有機溶媒とを含有するグリコール酸オリゴマー組成物であり、かつ、更に好ましくは、前記の工程(3)が、生成したグリコリドを該高沸点有機溶媒とともに反応容器から留出させる工程である前記のグリコリドの製造方法であることによって、グリコリド留出物中の遊離酸の濃度を更に低減できるので、効率性、経済性及びロングラン性に一層優れる、高純度のグリコリドを製造する方法を提供することができるという効果が奏される。
i)得られるグリコリドとして、純度が高いグリコリドを回収することができる。この結果、グリコリドの製造方法としての生産効率が向上するとともに、従来、必要であった晶析・再結晶等の後処理が容易となり、場合によっては、晶析や再結晶の処理を省略することも可能であるので、グリコリドの収率が向上する、
ii)グリコール酸オリゴマーの解重合反応によるグリコリドの製造を長時間継続しても、グリコール酸の重質化物や反応副生成物が解重合反応系に蓄積することが抑制され、グリコリドの生成速度の低下を抑制することができるので、ロングラン運転が可能となる。この結果、グリコリドの製造の中断や解重合反応装置等の清掃による生産効率の低下や、加熱冷却の繰り返しによる熱効率の低下を縮減することができる、
iii)高沸点有機溶媒の留出を含め、解重合を行うために費やした熱量のほとんどを精留工程を実施する熱量として利用し、回収することができるので省エネルギーであり、地球温暖化防止に寄与することができる、
iv)精留工程を実施するためには、従来配置されていた蒸留システムと置き換えることによっても可能であるので、設計やスケールアップが容易であり、工業的スケールでの量産化も容易である。さらに、反応容器と精留器を一体化すれば、蒸留設備を別個に設置する必要がないので、省スペース、省設備、省資源、省コストに寄与する、
v)特に、グリコール酸オリゴマー組成物として、グリコール酸オリゴマーと常圧における沸点が220~500℃の範囲である高沸点有機溶媒とを含有するグリコール酸オリゴマー組成物であることにより、更に好ましくは、生成したグリコリドを該高沸点有機溶媒とともに反応容器から留出させる前記のグリコリドの製造方法であることにより、得られるグリコリド中の遊離酸の濃度を更に低減できるので、効率性、経済性及びロングラン性に一層優れるグリコリドの製造方法を提供することができる、
vi)また、グリコール酸オリゴマーを溶液相、好ましくは均一溶液相で解重合を起こさせることによって、グリコール酸オリゴマーの表面積が増大し、同時に、グリコール酸オリゴマー同士の接触が溶媒の希釈効果によって抑制されるために、グリコール酸オリゴマー表面から解重合反応により生成するグリコリドの生成速度が大きくなる、
vii)さらに、前記の高沸点有機溶媒は、解重合反応及び留出工程において、熱劣化をほとんど起こさないので、解重合反応に使用した溶媒を再び解重合反応に用いることができ、連続運転中において、新たに補充する必要がある溶媒量を極く僅かにすることができる。したがって、環状エステルの大量生産を行う場合、溶媒コストを大幅に低減することができ、その結果、グリコリドなどの環状エステルを低コストで大量に生産することができる、などの効果が奏される。
工程(i)粗グリコリド組成物を反応容器に供給し、常圧下または減圧下に加熱して、グリコリドを留出させる工程、
工程(ii)留出物を精留器に導入して気液の向流接触により精留する工程、及び、
工程(iii)グリコリドを回収する工程
を備えることを特徴とする粗グリコリドの精製方法であることによって、不純物の含有量が少量またはほぼ皆無で、遊離酸の濃度が低減されたグリコリドを、高収率で得ることができる粗グリコリドの精製方法を提供することができるという効果が奏される。
本発明のグリコリドの製造方法は、グリコール酸オリゴマーを解重合してグリコリドを製造する方法である。本発明で出発原料として使用するグリコール酸オリゴマー(以下、「GAO」ということがある。)は、解重合によってグリコリドを生成することが可能な繰り返し単位を含有するグリコール酸の重合体またはグリコール酸の共重合体である。このようなGAOは、グリコール酸またはそのアルキルエステル若しくは塩を使用して、(共)重縮合することにより得ることができ、また、グリコリドをモノマーとして使用して、開環(共)重合することにより得ることができる。
本発明のGAOを解重合してグリコリドを製造する方法は、以下の工程(1)~(5):
工程(1)GAO組成物を反応容器に供給して、常圧下または減圧下に、該GAOの解重合反応が起る温度に加熱する工程、
工程(2)更に加熱を継続してGAOを解重合反応させてグリコリドを生成させる工程、
工程(3)生成したグリコリドを反応容器から留出させる工程、
工程(4)留出物を精留器に導入して気液の向流接触により精留する工程、及び、
工程(5)グリコリドを回収する工程
を備えることを特徴とするグリコリドの製造方法であり、好ましくは、前記のGAO組成物が、GAOと常圧における沸点が220~500℃の範囲である高沸点有機溶媒(以下、単に「高沸点有機溶媒」ということがある。)とを含有するGAO組成物であるグリコリドの製造方法である。
これら常圧における沸点が220~500℃の範囲である高沸点有機溶媒の中でも、芳香族ハロゲン化物であるp-クロロベンゾフェノン;芳香族カルボン酸アルコキシアルキルエステルであるジ(2-メトキシエチル)フタレート等のフタル酸ビス(アルコシキアルキルエステル);ポリアルキレングリコールエステルであるジエチレングリコールジベンゾエート等のジアルキレングリコールジベンゾエート;ポリアルキレングリコールエーテルであるペンタエチレングリコールジメチルエーテル、ヘキサエチレングリコールジメチルエーテル、ヘプタエチレングリコールジメチルエーテル等のポリエチレングリコールエーテル;は、GAOに対する大きな溶解力、化学的安定性、熱安定性などの観点から特に好ましい溶媒である。これらのGAOに対する溶解力が大きい高沸点有機溶媒を(a)グループの溶媒と呼ぶ。
特に好ましい(a)グループの溶媒は、ポリアルキレングリコールエーテルであり、最も好ましくは、下記式(1)
X-O-(-R-O-)p-Y (1)
(式中、Rは、メチレン基または炭素数2~8の直鎖状または分岐状のアルキレン基を表し、X及びYは、それぞれ独立して、メチル基または炭素数2~20のアルキル基またはアリール基を表し、pは、1以上の整数を表し、pが2以上である場合には、複数のRは、それぞれ同一でも異なってもよい。)
で表される少なくとも一種のポリアルキレングリコールエーテルである。
本発明においては、常圧における沸点が220~500℃の範囲である高沸点有機溶媒として、上記の(a)グループよりもGAOに対する溶解力が小さい高沸点有機溶媒も使用することができる。例えば、芳香族カルボン酸エステル、脂肪族カルボン酸エステル、芳香族ハロゲン化物、芳香族エーテル、脂肪族エーテル、芳香族リン酸エステル、脂肪族リン酸エステル、脂肪族イミド化合物、脂肪族アミド化合物、及びGAOに対する溶解力が小さく上記の(a)グループに属さないポリアルキレングリコールエーテルなどが挙げられる。これらの高沸点有機溶媒は、GAOの解重合反応が起る温度において、該オリゴマーを単独で溶解し得る溶解力が、(a)グループ溶媒に比較すると、概ね1/3以下、ほとんどの場合1/5以下、多くの場合1/10以下の前記溶解力が小さい高沸点有機溶媒である。これら溶解力の小さい高沸点有機溶媒を(b)グループの溶媒と呼ぶ。これらの(b)グループの溶媒は、通常、(a)グループの溶媒と混合して用いるか、または、後述する可溶化剤と組み合わせて用いることが好ましい。
(b)グループの溶媒に属するポリアルキレングリコールエーテルは、前記した式(1)
X-O-(-R-O-)p-Y (1)
で表されるポリアルキレングリコールエーテルであってもよい。ただし、この場合、両末端のエーテル基(X及びY)が、それぞれ独立して、メチル基または炭素数2~20のアルキル基またはアリール基であるが、より好ましくはX及びYがいずれも炭素数1~18のアルキル基であり、かつ、両末端のエーテル基に含まれるアルキル基の炭素数の合計が、好ましくは11~28、より好ましくは11~24の範囲にあるものを使用することができる。このようなアルキル基の例としては、メチル基、エチル基、プロピル基、ブチル基、ペンチル基、ヘキシル基、オクチル基、デシル基、ドデシル基、オクタデシル基等を組み合わせてなるものが挙げられる。これらのアルキル基は、直鎖状でも分岐状でもよい。
本発明のGAOを解重合してグリコリドを製造する方法においては、前記の高沸点有機溶媒に対するGAOの溶解特性(溶解度及び/または溶解速度)を改善するために使用されることがある可溶化剤を、高沸点有機溶剤ととともに、または単独で使用することができる。すなわち、GAO組成物は、可溶化剤を含有するGAO組成物であってもよい。
本発明で好ましく使用される前記の高沸点有機溶媒に相溶性または可溶性の化合物であれば、常温で液体でも固体でもよい。
常圧における沸点が190℃未満であると、GAOの解重合反応に先立つ加熱中や解重合反応中に、可溶化剤が沸騰し気化することにより解重合反応系及び留出ラインから逸散してしまい不都合な場合がある。また、可溶化剤を高沸点有機溶媒とともに使用する場合は、常圧における沸点が、高沸点有機溶媒の常圧における沸点より高い化合物を使用すると、可溶化剤が、グリコリド及び高沸点有機溶媒とともに留出しないか、または、留出量が極めて少なくなるので、望ましいことがある。この場合は、例えば、常圧における沸点が500℃以上の化合物(常圧における沸点を確認することができない化合物も含む。)を可溶化剤として使用することができる。
可溶化剤とGAOとの親和性は、以下の方法で確認することができる。すなわち、a)GAOと高沸点有機溶媒との混合物を温度230~280℃に加熱して均一な溶液相を形成させ、b)そこに、GAOを更に添加して、その濃度を、混合物が均一溶液相を形成しなくなるまで高め、c)そこに可溶化剤を加えて、再び均一溶液相を形成するか否かを目視により観察する。
HO-(-R1-O)q-H (2)
(式中、R1はメチレン基または炭素数2~8の直鎖状または分岐状のアルキレン基を表し、qは1以上の整数を表し、qが2以上の場合、複数のR1は、それぞれ同一でも異なってもよい。)
で表されるポリアルキレングリコールが好ましい。ポリアルキレングリコールの具体例としては、ポリエチレングリコール、ポリプロピレングリコール、ポリブチレングリコールなどが挙げられる。これらは、それぞれ単独で、または2種以上を組み合わせて使用することができる。
HO-(-R2-O)r-X1 (3)
(式中、R2はメチレン基または炭素数2~8の直鎖状または分岐状のアルキレン基を表し、X1は炭化水素基を表し、rは1以上の整数を表し、rが2以上の場合、複数のR2は、それぞれ同一でも異なってもよい。)
で表されるポリアルキレングリコールモノエーテルが好ましい。ポリアルキレングリコールモノエーテルの具体例としては、ポリエチレングリコールモノメチルエーテル、ポリエチレングリコールモノプロピルエーテル、ポリエチレングリコールモノブチルエーテル、ポリエチレングリコールモノヘキシルエーテル、ポリエチレングリコールモノオクチルエーテル、ポリエチレングリコールモノデシルエーテル、ポリエチレングリコールモノラウリルエーテル等のポリエチレングリコールモノエーテル;該ポリエチレングリコールモノエーテルにおいて、エチレンオキシ基をプロピレンオキシ基に代えたポリプロピレングリコールモノエーテル;該ポリエチレングリコールモノエーテルにおいて、エチレンオキシ基をブチレンオキシ基に代えたポリブチレングリコールモノエーテル;その他のポリアルキレングリコールモノエーテル;などが挙げられる。ポリエチレングリコールモノエーテルは、そのエーテル基として炭素数1~18のアルキル基を有するものが好ましい。これらは、それぞれ単独で、または2種以上を組み合わせて使用することができる。
本発明のGAOを解重合してグリコリドを製造する方法においては、特にGAO組成物が、GAOと常圧における沸点が220~500℃の範囲である高沸点有機溶媒とを含有するGAO組成物である場合は、解重合によるグリコリドの発生速度または揮発速度が大きくなることが多いので、一般に、解重合のための触媒(例えば、錫化合物、アンチモン化合物等)を用いる必要はない。また、熱安定性に優れたポリアルキレングリコールエーテル等の高分子の高沸点有機溶媒を使用してグリコリドを製造する場合において、触媒は、むしろ有害になるおそれもある。しかし、本発明を本質的に損なわない範囲において、触媒を使用することもできる。
本発明のGAOを解重合してグリコリドを製造する方法は、以下の工程(1)~(5)
工程(1)GAO組成物を反応容器に供給して、常圧下または減圧下に、該GAOの解重合反応が起る温度に加熱する工程、
工程(2)更に加熱を継続してGAOを解重合反応させてグリコリドを生成させる工程、
工程(3)生成したグリコリドを反応容器から留出させる工程、
工程(4)留出物を精留器に導入して気液の向流接触により精留する工程、及び、
工程(5)グリコリドを回収する工程
を備えるグリコリドの製造方法である。
工程(1’)GAOと常圧における沸点が220~500℃の範囲である高沸点有機溶媒とを含有するGAO組成物を反応容器に供給して、常圧下または減圧下に、GAOの解重合反応が起る温度に加熱する工程、
工程(2)更に加熱を継続してGAOを解重合反応させてグリコリドを生成させる工程、
工程(3)生成したグリコリドを反応容器から留出させる工程、
工程(4)留出物を精留器に導入して気液の向流接触により精留する工程、及び、
工程(5)グリコリドを回収する工程
を備えるグリコリドの製造方法である。
工程(1’)GAOと常圧における沸点が220~500℃の範囲である高沸点有機溶媒とを含有するGAO組成物を反応容器に供給して、常圧下または減圧下に、GAOの解重合反応が起る温度に加熱する工程、
工程(2)更に加熱を継続してGAOを解重合反応させてグリコリドを生成させる工程、
工程(3’)生成したグリコリドを該高沸点有機溶媒とともに反応容器から留出させる工程
工程(4)留出物を精留器に導入して気液の向流接触により精留する工程、及び、
工程(5)グリコリドを回収する工程
を備えるグリコリドの製造方法である。
本発明のグリコリドの製造方法は、反応容器と精留器とを備えることを特徴とする本発明のグリコリド製造装置を使用して実施することができる。
本発明のGAOを解重合してグリコリドを製造する方法におけるGAO組成物とは、GAOを必須の成分として含有する組成物を意味する。したがって、GAO組成物とは、実質的にGAOのみからなる組成物と、GAOと常圧における沸点が220~500℃の範囲である高沸点有機溶媒や可溶化剤等の他の成分とを含有する組成物との両方を意味する。したがって、GAO組成物としては、前記の高沸点有機溶媒を含有しないGAO組成物が包含される。なお、実質的にGAOのみからなる組成物とは、GAOと不純物等とを含有する組成物を包含する。
1)実質的にGAOのみからなるGAO組成物: 後述のように精留工程を備えるグリコリドの製造方法により、遊離酸濃度が小さく、かつ、純度が高いグリコリドを、安定して得ることができる。
2-1)GAOと、前記(a)グループの溶媒(高沸点有機溶媒)を含有するGAO組成物: 前記の常圧における沸点が220~500℃の範囲である高沸点有機溶媒に属する(a)グループの溶媒(高沸点有機溶媒)は、GAOに対する溶解力、化学的安定性、熱安定性などの観点から特に好ましい溶媒であり、GAOの融液相と実質的に均一な液相を形成することができるので、後述のように、精留工程を備えるグリコリドの製造方法により、遊離酸濃度が小さく、純度が高いグリコリドを、長時間に亘って安定して得ることができる。
2-2)GAOと、前記(b)グループの溶媒(高沸点有機溶媒)を含有するGAO組成物: 前記の常圧における沸点が220~500℃の範囲である高沸点有機溶媒に属する(b)グループの溶媒は、前記(a)グループの溶媒より、GAOに対する溶解力が小さい高沸点有機溶媒であるが、安価なものが多く、しかもGAOに対する溶解力を高めれば、グリコリドを比較的高収率で、かつ遊離酸濃度が小さいものとして得ることが期待できる。
2-3)GAOと、前記(a)グループの溶媒及び前記(b)グループの溶媒を含有するGAO組成物: 安価なものが多い前記(b)グループの溶媒を使用しつつ、GAOに対する溶解性を高め、GAOの融液相と実質的に均一な液相を形成することができるので、後述のように、精留工程を備えるグリコリドの製造方法により、遊離酸濃度が小さく、純度が高いグリコリドを、長時間に亘って安定して得ることができる。
3-1)GAOと、前記可溶化剤及び常圧における沸点が220~500℃の範囲である高沸点有機溶媒を含有するGAO組成物: GAOの溶解性が高い可溶化剤を併用することにより、GAOの融液相と実質的に均一な液相を形成することができ、GAOの解重合反応が迅速に進み、缶壁(反応容器内壁)や留出ラインのクリーニング効果が向上する等の効果が期待できる。
3-2)GAOと、前記(a)グループの溶媒及び前記可溶化剤を含有するGAO組成物: GAOの溶解性が高い可溶化剤を併用することにより、GAOの融液相と実質的に均一な液相を形成することができ、GAOの解重合反応が迅速に進み、缶壁(反応容器内壁)や留出ラインのクリーニング効果が向上する等の効果が期待できる。
3-3)GAOと、前記(b)グループの溶媒及び前記可溶化剤を含有するGAO組成物: 安価なものが多い前記(b)グループの溶媒を使用しつつ、GAOの溶解性が高い可溶化剤を併用することにより、GAOの解重合反応が迅速に進み、缶壁(反応容器内壁)や留出ラインのクリーニング効果が向上する等の効果が期待できる。
3-4)GAOと、前記(a)グループの溶媒、前記(b)グループの溶媒及び前記可溶化剤を含有するGAO組成物: GAOの溶解性が極めて高く、GAOの融液相と実質的に均一な液相を形成することができ、GAOの解重合反応が迅速に進み、缶壁(反応容器内壁)や留出ラインのクリーニング効果の向上が期待でき、遊離酸濃度が小さく、純度が高いグリコリドを、長時間に亘って安定して得ることができる。
本発明のグリコリドの製造方法は、GAO組成物、好ましくはGAOと常圧における沸点が220~500℃の範囲である高沸点有機溶媒とを含有するGAO組成物を反応容器に供給して、常圧下または減圧下に、該オリゴマーの解重合反応が起る温度に加熱する工程(加熱工程)を備える。加熱工程においては、所定量のGAO、及び、好ましくは常圧における沸点が220~500℃の範囲である高沸点有機溶媒、及び、必要に応じて加える可溶化剤を含有するGAO組成物を、常圧下または減圧下に、必要に応じて脱水のための加熱を行った後に、GAOの解重合が起こる温度、すなわち、通常180~320℃であり、好ましくは190~310℃、より好ましくは200~300℃、特に好ましくは210~290℃程度の温度に加熱する。加熱工程は、通常は常圧下で行えばよいが、窒素ガス等の不活性ガス雰囲気下で行うことが好ましく、減圧を行う場合は、0.1~90kPa、好ましくは0.5~50kPa、より好ましくは1~30kPaの範囲とすればよい。
加熱工程において、常圧における沸点が220~500℃の範囲である高沸点有機溶媒とを含有するGAO組成物を使用する場合、該高沸点有機溶媒として、加熱工程において、GAOの融液相の残存率を0.5以下とすることができるものである、すなわち、GAOの融液相と実質的に均一な液相を形成するものである、GAOに対して相溶性がある高沸点有機溶媒を使用することが特に好ましい。この場合、加熱工程において、GAOの全部または大半が該高沸点有機溶媒に溶解して、実質的に、GAOの溶液相が得られる。GAOを溶液状態で解重合反応させることにより、該オリゴマー表面から発生して揮発するグリコリドの生成速度が飛躍的に大きくなる。ここで、「融液相の残存率」とは、流動パラフィンのようにGAOに対して実質的に溶解力のない溶媒中に、GAO F(g)を加えて解重合が起こる温度に加熱した際に形成されるGAO融液相の容積がa(ml)、融液相の残存率を測定しようとする溶媒中でGAO F(g)を解重合が起こる温度に加熱して形成されるGAO融液相の容積がb(ml)である場合に、b/aの比率を表す。高沸点有機溶媒を単独で使用するもののほか、該高沸点有機溶媒と可溶化剤とを併用するものについても、融液相の残存率を測定することができる。GAO融液相の残存率は、好ましくは0.3以下、より好ましくは0.1以下、最も好ましくは実質的にゼロである。
加熱工程に続いて、GAO組成物、好ましくはGAOと常圧における沸点が220~500℃の範囲である高沸点有機溶媒とを含有するGAO組成物を、更に加熱を継続してGAOを解重合してグリコリドを生成させる工程(グリコリド生成工程)を行う。グリコリド生成工程を行う温度は、前記の加熱工程を行う温度と、同一でもよいし異なってもよい。すなわち、好ましくは180~320℃、より好ましくは200~290℃、特に好ましくは210~280℃程度の温度とすることができる。反応容器の減圧を行うと、解重合温度を上げることなく、GAOの解重合反応を行うことができ、グリコリドの発生及び揮発速度を大きくすることができるので好ましい。GAO解重合反応は、可逆反応であるためグリコリドを液相から留去することにより、GAOの解重合反応が効率的に進行する。グリコリド生成工程において、GAOの解重合反応を行う圧力は、0.1~90kPa、好ましくは0.3~50kPa、より好ましくは0.5~30kPa、更に好ましくは0.7~10kPaの範囲とすればよい。したがって、グリコリド生成工程は、温度180~320℃及び圧力0.1~90kPaの範囲で解重合反応を行うことが好ましい。一般に、解重合反応系の圧力を低くすることにより、グリコリド生成工程及び後述する精留工程を行う温度を低くすることができ、これにより、溶媒のロスが減少し、溶媒の回収率も高くなる。なお、解重合反応系の圧力を0.1kPa未満としても、グリコリド生成工程における効率の向上効果は増大せず、一方、装置の設計及び維持費用が急速に増大する傾向がある。
本発明のグリコリドの製造方法は、グリコリド生成工程において生成したグリコリドを、反応容器等から留出させる工程(留出工程)を行う。先に述べたように、反応容器には、留出成分を解重合反応系から留出させるための装置が連結されており、精留を行うための精留器を接続して配置してもよいし、また、精留を別途実施する場合は、単蒸留を行うための単管(冷却器を含むガラス管等)を接続して配置してもよい。
本発明のグリコリドの製造方法は、上記の留出工程で、反応容器から留出させられるグリコリドを含有する留出物、好ましくはグリコリドと前記高沸点有機溶媒とを含有する留出物を、精留器に導入して気液の向流接触により精留する工程(精留工程)を備える点に特徴を有する。
本発明のグリコリドの製造方法は、精留工程に続き、精留工程から留出するグリコリドを含有する混合物から、グリコリドを回収する工程(回収工程)を行う。回収工程においては、グリコリドまたはグリコリドを含有する精留塔等の精留器からの留出物を冷却し、必要に応じて、ろ別、遠心沈降、デカンテーション、液-液分離などの相分離、シクロヘキサン、エーテルなどの貧溶媒を用いた洗浄または抽出、酢酸エチル等を用いた晶析または再結晶など、常法により精製を行う回収操作を付加してもよい。しかし、本発明のグリコリドの製造方法によれば、純度の高いグリコリドを捕集することができるので、晶析等の回収操作が不要であるか、実施するとしても極めて容易かつ簡単である。
本発明においては、前記の精留工程及び/または回収工程において分離された、常圧における沸点が220~500℃の範囲である高沸点有機溶媒及び/または可溶化剤を前記の反応容器に還流してもよい。該高沸点有機溶媒及び/または必要に応じて使用する可溶化剤を、反応容器に還流して解重合反応系に戻し、加熱工程に供することにより、該高沸点有機溶媒等を再利用する際に追加が必要となる新たな高沸点有機溶媒等が、ごく少量ですむ。
本発明のグリコリドの製造方法によって製造されるグリコリドは、純度が高いグリコリドであり、また、遊離酸濃度が0.6mmol/g以下である安定性が高いグリコリドである。
本発明のグリコリドの製造方法によって得られるグリコリドは、純度が10質量%以上、好ましくは15質量%以上、より好ましくは40質量%以上、更に好ましくは60質量%以上、特に好ましくは70質量%以上、最も好ましくは80質量%以上のものである。得られるグリコリドの純度が10質量%以上であれば、晶析や再結晶等の精製が容易であり、使用用途またはグリコリドの純度によっては、精製が不要となることもある。グリコリドの純度の上限は、100質量%であるが、通常99.99質量%、多くの場合99.95質量%程度である。
解重合反応により生成したグリコリドの純度は、ガスクロマトグラフィー(GC)により測定する。グリコリド試料200mg及び内部標準物質としてのp-クロロベンゾフェノン(東京化成工業株式会社製)40mgを、アセトン10mlに溶解させる。その溶解液2μlを採取し、ガスクロマトグラフィー装置に注入して、グリコリド量の測定を行い、あらかじめ、グリコリドと内部標準物質であるp-クロロベンゾフェノンとを用いて作成した検量線を使用して、グリコリドの純度を求める。
<GC条件>
測定装置: 株式会社島津製作所製「GC-2010」
カラム: キャピラリーカラムTC-17、0.25mmφ×30mm
カラム温度: 280℃
インジェクション温度: 150℃
本発明のグリコリドの製造方法、すなわち解重合反応により生成したグリコリドは、遊離酸濃度が、0.6mmol/g以下、好ましくは0.55mmol/g以下、より好ましくは0.5mmol/g以下、更に好ましくは0.45mmol/g以下、特に好ましくは0.4mmol/g以下、最も好ましくは0.35mmol/g以下、とりわけ好ましくは0.3mmol/g以下であることにより、経時安定性が優れたグリコリドが得られることが分かった。本発明のグリコリドの製造方法によって製造されるグリコリドの遊離酸濃度の下限値は、できる限り遊離酸濃度が小さいグリコリドが望ましいことから0mmol/gであるが、通常は0.01mmol/g以上、多くの場合0.03mmol/g以上でも、何ら差し支えない。
グリコリド中の遊離酸濃度は、以下の方法により測定する。すなわちグリコリド試料30mgを、25mlのアセトンと25mlのメタノールとの混合溶媒に溶解する。ナトリウムメトキシドを含有するメタノール溶液を中和液として滴定し、中和点を検出する。検出した中和点から、グリコリド試料1g中に存在する遊離酸濃度をmmol数(単位:mmol/g)として算出する。
本発明のグリコリドの製造方法は、粗グリコリドの精製方法にも適用することができる。すなわち、本発明によれば、以下の工程(i)~(iii):
工程(i)粗グリコリド組成物を反応容器に供給し、常圧下または減圧下に加熱して、グリコリドを留出させる工程、
工程(ii)留出物を精留器に導入して気液の向流接触により精留する工程、及び、
工程(iii)グリコリドを回収する工程
を備えることを特徴とする粗グリコリドの精製方法が提供される。
前記の工程(i)が、グリコリドを該高沸点有機溶媒とともに留出させる工程である前記の粗グリコリドの精製方法を採用することができる。
本発明の粗グリコリドの精製方法は、反応容器と精留器とを備えることを特徴とする本発明の粗グリコリドの精製装置を使用して実施することができる。
解重合反応により生成したグリコリドの純度は、ガスクロマトグラフィー(GC)により測定した。グリコリド試料200mg及び内部標準物質のp-クロロベンゾフェノン(東京化成工業株式会社製)40mgを、アセトン10mlに溶解させ、その2μlを採取し、ガスクロマトグラフィー装置に注入して、グリコリド量の測定を行い、あらかじめ、グリコリドと標準物質のp-クロロベンゾフェノンとを用いて作成した検量線を用いて、グリコリドの純度を求めた。
<GC条件>
測定装置: 株式会社島津製作所製「GC-2010」
カラム: キャピラリーカラムTC-17、φ0.25mm×30mm
カラム温度: 280℃
インジェクション温度: 150℃
解重合反応により生成したグリコリド中の遊離酸濃度は、以下の方法により測定した。すなわちグリコリド試料30mgを、25mlのアセトンと25mlのメタノールとの混合溶媒に溶解した。ナトリウムメトキシドを含有するメタノール溶液を中和液として滴定し、中和点を検出する。検出した中和点から、グリコリド試料1g中に存在する遊離酸濃度をmmol数(単位:mmol/g)として算出した。
反応容器として、容積500mlの四ツ口フラスコを使用し、これに攪拌翼、温度計、及び圧力計測装置を配置して、解重合反応装置とした。該フラスコ上部の口部に、留出ラインを接続して配置し、留出ラインの出口には真空ライン及び受器を取り付けた。解重合反応系のフラスコを加熱するためにマントルヒーターを用いた。留出ラインとしては、実施例においては、精留を行うための精留器(冷却器を含む充填塔または棚段塔)を、また、比較例においては、単蒸留を行うための単管(冷却器を含むガラス管)を、それぞれ使用した。なお、留出ラインには放熱を防ぐためにリボンヒーターとグラスウール製の断熱材を巻きつけた。
容積5lのオートクレーブに、グリコール酸〔デュポン社製Glypure(登録商標)〕2,500gを仕込み、常圧で攪拌しながら170℃から200℃まで2時間かけて昇温加熱し、生成した水を留出させながら縮合反応を行った。次いで、缶内圧力を5.0kPaに減圧し、温度200℃で2時間加熱して、未反応原料等の低沸点成分を留去し、GAOを調製した。得られたGAOは、重量平均分子量19,000、融点218℃であった。
参考例1で調製したGAO150gとヘキサエチレングリコールジメチルエーテル(常圧における沸点356℃である前記の(a)グループの溶媒)150gとを含有するGAO組成物を、解重合反応装置の反応容器に投入し、窒素ガス雰囲気下、3.0kPaの減圧条件下で、温度220℃まで加熱した(加熱工程)。GAOは、溶媒に均一に溶解して、GAO融液相が存在せず、相分離していないことが目視により確認された。減圧条件を維持したまま、温度237℃に変更して加熱し続けると、GAO組成物が沸騰して解重合反応が開始し(グリコリド生成工程)、グリコリドを含有する混合物の留出が開始した(留出工程)。留出開始から1時間後、解重合反応装置に取り付けた精留器〔1.5メッシュステンレス金網を底に敷いた内径28mmのガラスカラムに、ディクソンパッキング(1/8in、トウトクエンジ株式会社製)を振動させながら、480mmの充填高さまで充填して得た充填塔。以下、「充填塔(φ28mm×480mm)」ということがある。〕上部の留出ラインのコックを閉めて、全還流運転を行って精留器の温度を安定化させた。その後、コックを開くと、精留器からグリコリドが留出して、留出ラインに取り付けた受器に溜まり出した。300分間(5時間)留出を続けたところ、問題なく精留操作をすることができた(精留工程)。受器に溜まった捕集物を回収して(回収工程)、GCで分析したところ、濃縮されたグリコリドであり、グリコリドの純度は97質量%で、グリコリド中の遊離酸濃度は0.35mmol/gであった。結果を表1に示す。
精留器として、前記の充填塔に代えて、スニーダー12段の棚段塔(内径20mm)を使用したこと、解重合反応の開始条件を、温度239℃、圧力3.5kPaとしたことを除いて、実施例1と同様にして、GAOの解重合反応を行った。300分間(5時間)留出を続けたところ、問題なく精留操作をすることができた。受器に溜まった捕集物を回収して、GCで分析したところ、濃縮されたグリコリドであり、グリコリドの純度は97質量%で、グリコリド中の遊離酸濃度は0.35mmol/gであった。結果を表1に示す。
精留器として、スニーダー12段の棚段塔(内径20mm)に代えて、スニーダー7段の棚段塔(内径20mm)を使用したこと、解重合反応の開始条件を、温度243℃、圧力4.1kPaとしたことを除いて、実施例2と同様にして、GAOの解重合反応を行った。300分間(5時間)留出を続けたところ、問題なく精留操作をすることができた。受器に溜まった捕集物を回収して、GCで分析したところ、濃縮されたグリコリドであり、グリコリドの純度は88質量%で、グリコリド中の遊離酸濃度は0.37mmol/gであった。結果を表1に示す。
参考例1で調製したGAO150gとヘプタエチレングリコールジメチルエーテル(常圧における沸点381℃である前記の(a)グループの溶媒)150gとを含有するGAO組成物を、解重合反応装置の反応容器に投入し、窒素ガス雰囲気下、3.0kPaの減圧条件下で、温度258℃まで加熱した(GAOは、溶媒に均一に溶解し、相分離していないことが目視により確認された。)こと、並びに、減圧条件及び温度を維持したまま、加熱し続けたことを除いて、実施例2と同様にして、GAOの解重合反応を行った。300分間(5時間)留出を続けたところ、問題なく精留操作をすることができた。受器に溜まった捕集物を回収して、GCで分析したところ、濃縮されたグリコリドであり、グリコリドの純度は98質量%で、グリコリド中の遊離酸濃度は0.31mmol/gであった。結果を表1に示す。
実施例1で使用した解重合反応装置及び精留器(充填塔)を使用して、参考例1で調整したGAO150gとペンタエチレングリコールジメチルエーテル(常圧における沸点319℃である前記の(a)グループの溶媒)150gとを含有するGAO組成物を、解重合反応装置の反応容器に投入し、窒素ガス雰囲気下、5.0kPaの減圧条件下で、温度220℃まで加熱した。GAOは、溶媒に均一に溶解し、相分離していないことが目視により確認された。更に、4.5kPaまで減圧し、温度217℃に変更して加熱し続けると、GAO組成物が沸騰して解重合反応が開始し、グリコリドを含有する混合物の留出が開始した。留出開始から1時間後、解重合反応装置に取り付けた精留器上部の留出ラインのコックを閉めて、全還流運転を行って精留器の温度を安定化させた後、コックを開いて、300分間(5時間)留出を続けたところ、問題なく精留操作をすることができた。受器に溜まった捕集物を回収して、GCで分析したところ、濃縮されたグリコリドであり、グリコリドの純度は72質量%で、グリコリド中の遊離酸濃度は0.34mmol/gであった。結果を表1に示す。
精留器として、充填塔(φ28mm×480mm)に代えて、精留器〔1.5メッシュステンレス金網を底に敷いた内径20mmのガラスカラムに、ディクソンパッキング(1/8in、トウトクエンジ株式会社製)を振動させながら、300mmの充填高さまで充填して得た充填塔。以下、「充填塔(φ20mm×300mm)」ということがある。〕を使用したこと、解重合反応の開始条件を、温度218℃に変更して加熱し続けたことを除いて、実施例5と同様にして、GAOの解重合反応を行った。300分間(5時間)留出を続けたところ、問題なく精留操作をすることができた。受器に溜まった捕集物を回収して、GCで分析したところ、濃縮されたグリコリドであり、グリコリドの純度は20質量%で、グリコリド中の遊離酸濃度は0.38mmol/gであった。結果を表1に示す。
参考例1で調製したGAO150gと、p-クロロベンゾフェノン(常圧における沸点332℃である前記の(a)グループの溶媒)150gとを含有するGAO組成物を、解重合反応装置の反応容器に投入し、窒素ガス雰囲気下、6.0kPaの減圧条件下で、温度227℃まで加熱した(GAOは、溶媒に均一に溶解し、相分離していないことが目視により確認された。)こと、減圧条件及び温度を維持したまま、加熱し続けたことを除いて、実施例1と同様にして、GAOの解重合反応を行った。300分間(5時間)留出を続けたところ、問題なく精留操作をすることができた。受器に溜まった捕集物を回収して、GCで分析したところ、濃縮されたグリコリドであり、グリコリドの純度は74質量%で、グリコリド中の遊離酸濃度は0.21mmol/gであった。結果を表1に示す。
参考例1で調製したGAO150gと、トリエチレングリコールブチルオクチルエーテル(常圧における沸点354℃である前記の(b)グループの溶媒)及びポリエチレングリコールモノメチルエーテル〔日本乳化剤株式会社、MPG-130H2、常圧における沸点が220~500℃の範囲である成分を25質量%以上含有する)混合物である可溶化剤〕の質量比1:1の混合溶媒150gとを含有するGAO組成物を、解重合反応装置の反応容器に投入し、窒素ガス雰囲気下、3.5kPaの減圧条件下で、温度240℃まで加熱した(GAOは、溶媒にほぼ溶解していたが、僅かに曇りがみられることが目視により確認された。)こと、温度234℃、圧力3.0kPaに変更して加熱し続けたことを除いて、実施例3と同様にして、GAOの解重合反応を行った。300分間(5時間)留出を続けたところ、問題なく精留操作をすることができた。受器に溜まった捕集物の内、グリコリド相を回収して、GCで分析したところ、濃縮されたグリコリドであり、グリコリドの純度は91質量%で、グリコリド中の遊離酸濃度は0.58mmol/gであった。結果を表1に示す。
参考例1で調製したGAO150gと、4-α-クミルフェノール(常圧における沸点335℃である可溶化剤)150gとを含有するGAO組成物を、解重合反応装置の反応容器に投入し、窒素ガス雰囲気下、3.5kPaの減圧条件下で、温度230℃まで加熱した(GAOは、溶媒に均一に溶解し、相分離していないことが目視により確認された。)こと、減圧条件及び温度を維持したまま、加熱し続けたことを除いて、実施例1と同様にして、GAOの解重合反応を行った。300分間(5時間)留出を続けたところ、問題なく精留操作をすることができた。受器に溜まった捕集物を回収して、GCで分析したところ、濃縮されたグリコリドであり、グリコリドの純度は88質量%で、グリコリド中の遊離酸濃度は0.20mmol/gであった。結果を表1に示す。
参考例1で調製したGAO150gと、実施例8で使用したポリエチレングリコールモノメチルエーテル(可溶化剤)150gとを含有するGAO組成物を、解重合反応装置の反応容器に投入し、窒素ガス雰囲気下、1.0kPaの減圧条件下で、温度230℃まで加熱して(GAOは、溶媒に均一に溶解し、相分離していないことが目視により確認された。)、解重合反応を開始し、減圧条件を維持したまま、温度を255℃まで昇温させながら加熱し、解重合反応を続けたことを除いて、実施例6と同様にして、GAOの解重合反応を行った。300分間(5時間)留出を続けたところ、問題なく精留操作をすることができた。受器に溜まった捕集物を回収して、GCで分析したところ、濃縮されたグリコリドであり、グリコリドの純度は85質量%で、グリコリド中の遊離酸濃度は0.20mmol/gであった。結果を表1に示す。
解重合反応装置の反応容器であるフラスコ上部の口部に接続して配置する留出ラインとして、精留器である充填塔(φ28m×480mm)に代えて、単管を取り付けたこと、及び、3.0kPaの減圧条件下で、温度230℃まで加熱して解重合反応を開始し、グリコリドを含む混合物の留出が開始した後、減圧条件を維持したまま、温度を241℃まで昇温させながら加熱し、解重合反応を続けたことを除いて、実施例1と同様にして、GAOの解重合反応を行った。受器に溜まった捕集物を回収して、GCで分析したところ、回収したグリコリドの純度は5質量%で、グリコリド中の遊離酸濃度は0.39mmol/gであった。結果を表1に示す。
解重合反応装置の反応容器であるフラスコ上部の口部に接続して配置する留出ラインとして、精留器である充填塔(φ28m×480mm)に代えて、単管を取り付けたこと、及び、3.0kPaの減圧条件下で、温度233℃まで加熱して解重合反応を開始し、グリコリドを含む混合物の留出が開始した後、減圧条件を維持したまま、温度を244℃まで昇温させながら加熱し、解重合反応を続けたことを除いて、実施例9と同様にして、GAOの解重合反応を行った。180分間(3時間)留出を続けたところ、留出ラインに留出物の付着残渣はほとんどみられなかったが、グリコリドの留出がなくなってきたので、解重合反応を終了した。受器に溜まった捕集物を回収して、GCで分析したところ、回収したグリコリドの純度は4質量%で、グリコリド中の遊離酸濃度は0.22mmol/gであった。結果を表1に示す。
解重合反応装置の反応容器であるフラスコ上部の口部に接続して配置する留出ラインとして、精留器である充填塔(φ28m×480mm)に代えて、単管を取り付けたこと、並びに、3.0kPaの減圧条件下で、温度230℃まで加熱して解重合反応を開始し、グリコリドを含む混合物の留出が開始した後、減圧条件を維持したまま、温度を244℃まで昇温させながら加熱し、解重合反応を続けたことを除いて、実施例8と同様にして、GAOの解重合反応を行った。受器に溜まった捕集物の内、グリコリド相を回収して、GCで分析したところ、回収したグリコリドの純度は81質量%で、グリコリド中の遊離酸濃度は1.08mmol/gであった。結果を表1に示す。
工程(1)GAO組成物を反応容器に供給して、常圧下または減圧下に、該GAOの解重合反応が起る温度に加熱する工程、
工程(2)更に加熱を継続してGAOを解重合反応させてグリコリドを生成させる工程、
工程(3)生成したグリコリドを反応容器から留出させる工程、
工程(4)留出物を精留器に導入して気液の向流接触により精留する工程、及び、
工程(5)グリコリドを回収する工程
を備える、実施例1~10のグリコリドの製造方法においては、300分間(5時間)留出を続けても、問題なく精留操作をすることができ、回収したグリコリドの純度が20~98質量%と高く、かつ、遊離酸濃度が0.20~0.58mmol/gと小さい、安定性に優れたグリコリドが得られることが分かった。
参考例1で調製したGAO150gからなるGAO組成物(高沸点有機溶媒及び/または可溶化剤を含有しない。)を、解重合反応装置の反応容器に投入し、窒素ガス雰囲気下、1.0kPaの減圧条件下で、温度235℃まで加熱して解重合反応を開始したところ、グリコリドを含む混合物が反応容器から精留装置に留出し始めた。解重合反応系からのグリコリドの留出が開始してから1時間後、解重合反応装置に取り付けた精留器〔充填塔(φ20mm×300mm)〕上部の留出ラインのコックを閉めて、全還流運転を行って精留器の温度を安定化させた。その後、コックを開くと、精留器からグリコリドが留出して、留出ラインに取り付けた受器に溜まり出した。減圧条件を維持したまま、温度を278℃まで昇温させながら、210分間(3.5時間)留出を続けたところ、問題なく精留操作をすることができた。受器に溜まった捕集物を回収して、GCで分析したところ、濃縮されたグリコリドであり、グリコリドの純度は96質量%で、グリコリド中の遊離酸濃度は0.5mmol/gであった。結果を表2に示す。
解重合反応装置であるフラスコ上部の口部に取り付ける留出ラインとして、精留器である前記の充填塔に代えて、単管を取り付けて、実施例11と同様に解重合反応を行った。温度及び圧力条件として、1.0kPaの減圧条件下で、温度237℃まで加熱して解重合反応を開始し、グリコリドを含む混合物の留出が開始した後、減圧条件を維持したまま、温度を260℃まで昇温させながら加熱して解重合反応を続け、留出物の捕集を行った。受器に溜まった捕集物を回収して、GCで分析したところ、回収したグリコリドの純度は82質量%で、グリコリド中の遊離酸濃度は1.49mmol/gであった。結果を表2に示す。
工程(1)GAO組成物を反応容器に供給して、常圧下または減圧下に、該GAOの解重合反応が起る温度に加熱する工程、
工程(2)更に加熱を継続してGAOを解重合反応させてグリコリドを生成させる工程、
工程(3)生成したグリコリドを反応容器から留出させる工程、
工程(4)留出物を精留器に導入して気液の向流接触により精留する工程、及び、
工程(5)グリコリドを回収する工程
を備える、実施例11のグリコリドの製造方法、具体的には、GAO組成物が、常圧における沸点が220~500℃の範囲である高沸点有機溶媒及び/または可溶化剤を含有しないGAO組成物であり、該GAOを解重合反応させてグリコリドを生成させる反応容器に接続して配置する留出ラインとして、精留器〔充填塔(φ20mm×300mm)〕を使用し、留出したグリコリドを気液の向流接触により精留した実施例11のグリコリドの製造方法によれば、210分間(3.5時間)留出を続けても、問題なく精留操作をすることができ、回収したグリコリドの純度が96質量%と高く、かつ、遊離酸濃度が0.50mmol/gと低く、安定性に優れるグリコリドが得られることが分かった。
グリコリド(純度99.96質量%以上)150g、グリコール酸(和光純薬工業株式会社製、071-01512)15g及び、ヘキサエチレングリコールジメチルエーテル(常圧における沸点356℃である高沸点有機溶媒)100gを、精留器として、実施例1において使用した充填塔(φ28mm×480mm)を接続して配置した反応容器(容積500mlの四ツ口フラスコ)に投入して、粗グリコリド組成物を調製した。粗グリコリド組成物中のグリコリド濃度は56.6質量%、溶媒(ヘキサエチレングリコールジメチルエーテル)濃度は37.7質量%で、遊離酸濃度は0.74mmol/gであった。グリコリドと溶媒以外の不純物(グリコール酸が相当)の合計に対するグリコリドの比率は90.9質量%であった。
工程(1)GAO組成物を反応容器に供給して、常圧下または減圧下に、該GAOの解重合反応が起る温度に加熱する工程、
工程(2)更に加熱を継続してGAOを解重合反応させてグリコリドを生成させる工程、
工程(3)生成したグリコリドを反応容器から留出させる工程、
工程(4)留出物を精留器に導入して気液の向流接触により精留する工程、及び、
工程(5)グリコリドを回収する工程
を備えることを特徴とするグリコリドの製造方法であることによって、製造効率の低下がなく長期間に亘って反応を継続することができ、効率的かつ経済的に、GAOを解重合して高純度かつ遊離酸濃度が低減され安定性に優れるグリコリドを製造する方法が提供されるので、産業上の利用可能性が高い。
工程(i)粗グリコリド組成物を反応容器に供給し、常圧下または減圧下に加熱して、グリコリドを留出させる工程、
工程(ii)留出物を精留器に導入して気液の向流接触により精留する工程、及び、
工程(iii)グリコリドを回収する工程
を備えることを特徴とする粗グリコリドの精製方法であることによって、高収率で、高純度かつ遊離酸の濃度が低減され安定性に優れるグリコリドを得ることができる粗グリコリドの精製方法が提供されるので、産業上の利用可能性が高い。
Claims (18)
- グリコール酸オリゴマーを解重合してグリコリドを製造する方法において、以下の工程(1)~(5):
工程(1)グリコール酸オリゴマー組成物を反応容器に供給して、常圧下または減圧下に、該グリコール酸オリゴマーの解重合反応が起る温度に加熱する工程、
工程(2)更に加熱を継続してグリコール酸オリゴマーを解重合反応させてグリコリドを生成させる工程、
工程(3)生成したグリコリドを反応容器から留出させる工程、
工程(4)留出物を精留器に導入して気液の向流接触により精留する工程、及び、
工程(5)グリコリドを回収する工程
を備えることを特徴とするグリコリドの製造方法。 - 前記のグリコール酸オリゴマー組成物が、グリコール酸オリゴマーと常圧における沸点が220~500℃の範囲である高沸点有機溶媒とを含有するグリコール酸オリゴマー組成物である請求項1記載のグリコリドの製造方法。
- 工程(3)が、生成したグリコリドを前記の高沸点有機溶媒とともに反応容器から留出させる工程である請求項2記載のグリコリドの製造方法。
- 前記の高沸点有機溶媒が、芳香族カルボン酸アルコキシアルキルエステル、脂肪族カルボン酸アルコキシアルキルエステル、ポリアルキレングリコールエーテル、ポリアルキレングリコールエステル、芳香族カルボン酸エステル、脂肪族カルボン酸エステル、芳香族エーテル、脂肪族エーテル、芳香族リン酸エステル、脂肪族リン酸エステル、脂肪族イミド化合物、脂肪族アミド化合物、及び芳香族ハロゲン化物からなる群より選ばれる少なくとも一種である請求項2または3記載のグリコリドの製造方法。
- 前記の高沸点有機溶媒が、前記の工程(1)において、グリコール酸オリゴマーの融液相と実質的に均一な液相を形成するものである請求項2乃至4のいずれ1項に記載のグリコリドの製造方法。
- 前記の高沸点有機溶媒が、式(1)
X-O-(-R-O-)p-Y (1)
(式中、Rは、メチレン基または炭素数2~8の直鎖状または分岐状のアルキレン基を表し、X及びYは、それぞれ独立して、メチル基または炭素数2~20のアルキル基またはアリール基を表し、pは、1以上の整数を表し、pが2以上である場合には、複数のRは、それぞれ同一でも異なってもよい。)
で表される少なくとも一種のポリアルキレングリコールエーテルである請求項2乃至5のいずれ1項に記載のグリコリドの製造方法。 - 前記のグリコール酸オリゴマー組成物が、可溶化剤を含有するグリコール酸オリゴマー組成物である請求項1乃至6のいずれか1項に記載のグリコリドの製造方法。
- 前記の可溶化剤が、常圧における沸点が190℃以上の一価または多価アルコールまたはフェノール化合物である請求項7記載のグリコリドの製造方法。
- 前記の工程(2)において、温度180~320℃及び圧力0.1~90kPaの範囲で解重合反応を行う請求項1乃至8のいずれか1項に記載のグリコリドの製造方法。
- 前記の工程(4)及び/または工程(5)において分離された常圧における沸点が220~500℃の範囲である高沸点有機溶媒及び/または可溶化剤を、前記の反応容器に還流する請求項1乃至9のいずれか1項に記載のグリコリドの製造方法。
- 工程(4)を、前記の反応容器に接続して配置した精留器を使用して実施する請求項1乃至10のいずれか1項に記載のグリコリドの製造方法。
- グリコール酸オリゴマー組成物が、常圧における沸点が220~500℃の範囲である高沸点有機溶媒を含有しないグリコール酸オリゴマー組成物である請求項1乃至11のいずれか1項に記載のグリコリドの製造方法。
- 以下の工程(i)~(iii):
工程(i)粗グリコリド組成物を反応容器に供給し、常圧下または減圧下に加熱して、グリコリドを留出させる工程、
工程(ii)留出物を精留器に導入して気液の向流接触により精留する工程、及び、
工程(iii)グリコリドを回収する工程
を備えることを特徴とする粗グリコリドの精製方法。 - 前記の粗グリコリド組成物が、粗グリコリドと常圧における沸点が220~500℃の範囲である高沸点有機溶媒とを含有する粗グリコリド組成物であり、かつ、
前記の工程(i)が、グリコリドを該高沸点有機溶媒とともに留出させる工程である請求項13記載の粗グリコリドの精製方法。 - 前記の粗グリコリド組成物が、可溶化剤を含有する粗グリコリド組成物である請求項13または14記載の粗グリコリドの精製方法。
- 前記の工程(ii)及び/または工程(iii)において分離された常圧における沸点が220~500℃の範囲である高沸点有機溶媒及び/または可溶化剤を、前記の反応容器に還流する請求項13乃至15のいずれか1項に記載の粗グリコリドの精製方法。
- 反応容器と精留器とを備えることを特徴とするグリコリドの製造装置。
- 反応容器と精留器とを備えることを特徴とする粗グリコリドの精製装置。
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CN114478468B (zh) * | 2020-10-26 | 2023-08-08 | 中国石油化工股份有限公司 | 一种精制乙交酯的方法及其所得乙交酯 |
CN113603671A (zh) * | 2021-08-13 | 2021-11-05 | 山东谷雨春生物科技有限公司 | 一种提高交酯收率的方法 |
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Citations (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2668162A (en) | 1952-03-20 | 1954-02-02 | Du Pont | Preparation of high molecular weight polyhydroxyacetic ester |
US3435008A (en) * | 1967-08-22 | 1969-03-25 | American Cyanamid Co | Method for preparation of isomerically pure beta-glycolide and polymerization method for glycolide compositions employing partial hydrolyzate of said beta-glycolide |
US4727163A (en) | 1985-07-11 | 1988-02-23 | E. I. Du Pont De Nemours And Company | Process for preparing highly pure cyclic esters |
US4835293A (en) | 1987-02-24 | 1989-05-30 | E. I. Du Pont De Nemours And Company | Atmospheric pressure process for preparing pure cyclic esters |
FR2692263A1 (fr) | 1992-06-15 | 1993-12-17 | Flamel Tech Sa | Procédé de préparation d'esters cycliques d'acides-alpha-hydroxycarboxyliques. |
JPH09328481A (ja) | 1996-02-09 | 1997-12-22 | Kureha Chem Ind Co Ltd | α−ヒドロキシカルボン酸2量体環状エステルの製造方法及び精製方法 |
WO2001072736A1 (fr) * | 2000-03-31 | 2001-10-04 | Kureha Kagaku Kogyo K.K. | Procede de purification d'ester cyclique |
WO2002014303A1 (fr) | 2000-08-11 | 2002-02-21 | Kureha Kagaku Kogyo K.K. | Procede de preparation d'esters cycliques et procede de purification desdits esters |
JP2002128777A (ja) * | 2000-10-20 | 2002-05-09 | Kureha Chem Ind Co Ltd | グリコリドの精製方法 |
WO2002083661A1 (en) * | 2001-04-12 | 2002-10-24 | Kureha Chemical Industry Company, Limited | Glycolide production process, and glycolic acid oligomer for glycolide production |
WO2003004126A2 (en) * | 2001-03-15 | 2003-01-16 | A.E. Staley Manufacturing Co. | Azeotropic distillation of cyclic esters of hydroxy organic acids |
WO2006114432A2 (en) * | 2005-04-28 | 2006-11-02 | Purac Biochem Bv | Method for purifying glycolide |
WO2006129736A1 (ja) | 2005-06-01 | 2006-12-07 | Mitsui Chemicals, Inc. | 環状エステルの製造方法 |
WO2010073512A1 (ja) * | 2008-12-26 | 2010-07-01 | 株式会社クレハ | グリコリドの製造方法 |
Family Cites Families (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5117008A (en) | 1990-10-23 | 1992-05-26 | E. I. Du Pont De Nemours And Company | Solvent scrubbing recovery of lactide and other dimeric cyclic esters |
US5830991A (en) | 1996-02-09 | 1998-11-03 | Kureha Kagaku Kagyo Kk | Preparation process and purification process of dimeric cyclic ester of hydroxycarboxylic acid |
CN1448209A (zh) | 2002-04-02 | 2003-10-15 | 吴尔盛 | 一种烟气干法脱硫治污技术 |
ATE391741T1 (de) | 2002-10-08 | 2008-04-15 | Kureha Corp | Verfahren zur herstellung von aliphatischem polyester |
WO2005056509A1 (en) | 2003-12-10 | 2005-06-23 | Tate & Lyle Public Limited Company | Purification process for lactide |
CN101887885B (zh) | 2009-05-12 | 2012-05-09 | 日月光封装测试(上海)有限公司 | 半导体封装体的堆叠构造 |
CN101857585A (zh) * | 2010-05-21 | 2010-10-13 | 常州大学 | 丙交酯连续高真空精馏提纯方法 |
CN104619690B (zh) * | 2012-11-22 | 2016-10-12 | 株式会社吴羽 | 具备通过气液逆流接触而进行的精馏工序的乙交酯的制造方法、以及粗乙交酯的精炼方法 |
-
2013
- 2013-11-19 CN CN201380046913.0A patent/CN104619690B/zh active Active
- 2013-11-19 WO PCT/JP2013/081100 patent/WO2014080876A1/ja active Application Filing
- 2013-11-19 JP JP2014548561A patent/JP6326373B2/ja active Active
- 2013-11-19 US US14/433,162 patent/US9365536B2/en active Active
- 2013-11-19 KR KR1020157005599A patent/KR101706484B1/ko active IP Right Grant
- 2013-11-19 EP EP13856470.3A patent/EP2924030B1/en active Active
-
2016
- 2016-04-22 US US15/136,656 patent/US20160236112A1/en not_active Abandoned
Patent Citations (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2668162A (en) | 1952-03-20 | 1954-02-02 | Du Pont | Preparation of high molecular weight polyhydroxyacetic ester |
US3435008A (en) * | 1967-08-22 | 1969-03-25 | American Cyanamid Co | Method for preparation of isomerically pure beta-glycolide and polymerization method for glycolide compositions employing partial hydrolyzate of said beta-glycolide |
US4727163A (en) | 1985-07-11 | 1988-02-23 | E. I. Du Pont De Nemours And Company | Process for preparing highly pure cyclic esters |
JPS63152375A (ja) | 1986-10-29 | 1988-06-24 | イー・アイ・デユポン・ドウ・ヌムール・アンド・カンパニー | 高純度環状エステルの製造方法 |
US4835293A (en) | 1987-02-24 | 1989-05-30 | E. I. Du Pont De Nemours And Company | Atmospheric pressure process for preparing pure cyclic esters |
FR2692263A1 (fr) | 1992-06-15 | 1993-12-17 | Flamel Tech Sa | Procédé de préparation d'esters cycliques d'acides-alpha-hydroxycarboxyliques. |
JPH09328481A (ja) | 1996-02-09 | 1997-12-22 | Kureha Chem Ind Co Ltd | α−ヒドロキシカルボン酸2量体環状エステルの製造方法及び精製方法 |
WO2001072736A1 (fr) * | 2000-03-31 | 2001-10-04 | Kureha Kagaku Kogyo K.K. | Procede de purification d'ester cyclique |
WO2002014303A1 (fr) | 2000-08-11 | 2002-02-21 | Kureha Kagaku Kogyo K.K. | Procede de preparation d'esters cycliques et procede de purification desdits esters |
JP2002128777A (ja) * | 2000-10-20 | 2002-05-09 | Kureha Chem Ind Co Ltd | グリコリドの精製方法 |
WO2003004126A2 (en) * | 2001-03-15 | 2003-01-16 | A.E. Staley Manufacturing Co. | Azeotropic distillation of cyclic esters of hydroxy organic acids |
WO2002083661A1 (en) * | 2001-04-12 | 2002-10-24 | Kureha Chemical Industry Company, Limited | Glycolide production process, and glycolic acid oligomer for glycolide production |
WO2006114432A2 (en) * | 2005-04-28 | 2006-11-02 | Purac Biochem Bv | Method for purifying glycolide |
WO2006129736A1 (ja) | 2005-06-01 | 2006-12-07 | Mitsui Chemicals, Inc. | 環状エステルの製造方法 |
WO2010073512A1 (ja) * | 2008-12-26 | 2010-07-01 | 株式会社クレハ | グリコリドの製造方法 |
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US20160236112A1 (en) | 2016-08-18 |
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EP2924030B1 (en) | 2020-01-01 |
US9365536B2 (en) | 2016-06-14 |
EP2924030A1 (en) | 2015-09-30 |
EP2924030A4 (en) | 2016-04-06 |
KR20150039831A (ko) | 2015-04-13 |
KR101706484B1 (ko) | 2017-02-13 |
CN104619690A (zh) | 2015-05-13 |
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