JPH11292871A - Method for producing lactide capable of suppressing racemization - Google Patents
Method for producing lactide capable of suppressing racemizationInfo
- Publication number
- JPH11292871A JPH11292871A JP9627498A JP9627498A JPH11292871A JP H11292871 A JPH11292871 A JP H11292871A JP 9627498 A JP9627498 A JP 9627498A JP 9627498 A JP9627498 A JP 9627498A JP H11292871 A JPH11292871 A JP H11292871A
- Authority
- JP
- Japan
- Prior art keywords
- lactic acid
- lactide
- acid oligomer
- optical purity
- depolymerization
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Landscapes
- Heterocyclic Compounds That Contain Two Or More Ring Oxygen Atoms (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、乳酸オリゴマーを
解重合して乳酸の環状二量体であるラクチドを製造する
方法に関し、より詳しくは、解重合の際のラセミ化を抑
制し、ラクチドを留出させ得る製造方法に関するもので
ある。ラクチドは生分解性ポリマーであるポリ乳酸の製
造原料として特に有用なものである。The present invention relates to a method for producing lactide, which is a cyclic dimer of lactic acid, by depolymerizing a lactic acid oligomer, and more particularly, to suppressing racemization during depolymerization to reduce lactide. The present invention relates to a production method which can be distilled. Lactide is particularly useful as a raw material for producing polylactic acid, a biodegradable polymer.
【０００２】[0002]
【従来の技術】従来より、ラクチドの製造は、乳酸を脱
水縮合して比較的低分子量の乳酸オリゴマーを中間体と
して得て、次いで乳酸オリゴマーを触媒存在下、減圧下
で加熱して解重合することによってラクチドを生成さ
せ、これを蒸気として反応系外に取り出す、いわゆる反
応蒸留法によって行われている。2. Description of the Related Art Conventionally, lactide has been produced by dehydrating and condensing lactic acid to obtain a relatively low molecular weight lactic acid oligomer as an intermediate, and then depolymerizing the lactic acid oligomer by heating under reduced pressure in the presence of a catalyst. In this way, lactide is produced, and the lactide is taken out of the reaction system as a vapor.
【０００３】このラクチド製造方法には多くの研究例が
知られている。たとえば、独国特許第267826号明細書に
は、真空中にて乳酸を200 ℃に加熱し、蒸留するラクチ
ド製造方法が記載されている。また、独国特許第123470
3 号明細書には、Ｌ−乳酸水溶液を原料としてチタンテ
トラアルコキシド触媒存在下で、Ｌ−ラクチドを製造す
る方法が記載されている。また、特開昭63-101378 号公
報には、工業規模でのラクチドの製造方法が記載されて
おり、特表平7-500091号公報には、低分子量の乳酸オリ
ゴマーから薄膜蒸留を利用してラクチドを連続的に製造
する方法が記載されている。[0003] Many research examples are known for this lactide production method. For example, DE 267826 describes a method for producing lactide in which lactic acid is heated to 200 ° C. in a vacuum and distilled. Also, German Patent No. 123470
No. 3 discloses a method for producing L-lactide from an aqueous L-lactic acid solution in the presence of a titanium tetraalkoxide catalyst. Japanese Patent Application Laid-Open No. 63-101378 describes a method for producing lactide on an industrial scale, and Japanese Patent Application Laid-Open No. 7-500091 discloses a method using thin film distillation from a low molecular weight lactic acid oligomer. A method for continuously producing lactide is described.
【０００４】[0004]
【発明が解決しようとする課題】しかしながら、これら
従来の方法によれば、ラクチドを留出させる際のラセミ
化は避けられない問題であった。すなわち、反応温度を
高くするとラセミ化が起こり、原料の乳酸オリゴマーと
して、光学純度の高いＬ−乳酸オリゴマーやＤ−乳酸オ
リゴマーを用いても、得られるラクチドの光学純度は低
下してしまう。光学純度の低下は、光学純度の高いラク
チドが必要な場合には、非常に大きな問題であった。However, according to these conventional methods, racemization in distilling lactide is an unavoidable problem. That is, when the reaction temperature is increased, racemization occurs, and even when an L-lactic acid oligomer or a D-lactic acid oligomer having a high optical purity is used as a lactic acid oligomer as a raw material, the optical purity of the obtained lactide decreases. The decrease in optical purity was a very serious problem when lactide with high optical purity was required.
【０００５】そこで、本発明の目的は、上記従来の技術
の課題を解決し、高光学純度のラクチド生成物を得るこ
とができるラクチドの製造方法を提供することにある。Accordingly, an object of the present invention is to solve the above-mentioned problems of the prior art and to provide a method for producing lactide capable of obtaining a lactide product having high optical purity.
【０００６】[0006]
【課題を解決するための手段】本発明者らは鋭意検討し
た結果、反応系内に塩化銅を添加し、乳酸オリゴマーを
解重合することによって、上記目的を達成できることを
見出し、本発明を完成するに至った。すなわち、本発明
のラクチドの製造方法は、乳酸オリゴマーの解重合によ
るラクチドの製造方法であって、反応系内に塩化銅を添
加し、適切な温度、および圧力条件下で乳酸オリゴマー
を解重合して、生成したラクチドを留出させる方法であ
る。Means for Solving the Problems As a result of intensive studies, the present inventors have found that the above object can be achieved by adding copper chloride to the reaction system and depolymerizing the lactic acid oligomer, and completed the present invention. I came to. That is, the method for producing lactide of the present invention is a method for producing lactide by depolymerization of lactic acid oligomer, in which copper chloride is added to the reaction system, and the lactic acid oligomer is depolymerized under appropriate temperature and pressure conditions. This is a method of distilling the produced lactide.
【０００７】以下、本発明について詳しく説明する。本
発明で原料として用いる乳酸オリゴマーは、特に限定さ
れないが、重量平均分子量が400 〜30000 程度の比較的
低分子量のものである。この乳酸オリゴマーは、従来よ
り知られている方法、すなわち乳酸モノマーを適切な加
熱温度および減圧条件下で脱水縮合して製造することが
できる。たとえば、乳酸モノマーを減圧（一般に６×10
2 〜1.5 ×104 Pa程度）下で加熱（一般に120 〜170
℃）して脱水することによって、重量平均分子量400 〜
30000 程度の乳酸オリゴマーを得ることができる。本方
法においては、上記のように乳酸モノマーから乳酸オリ
ゴマーを得て、その乳酸オリゴマーを取り出すことなし
に、そのまま解重合反応を行うこともできる。乳酸オリ
ゴマーはＬ−乳酸オリゴマー、Ｄ−乳酸オリゴマー、Ｄ
Ｌ−乳酸オリゴマーまたは任意のＤ、Ｌ比率の乳酸オリ
ゴマーのいずれを用いてもよい。Hereinafter, the present invention will be described in detail. The lactic acid oligomer used as a raw material in the present invention is not particularly limited, but has a relatively low molecular weight having a weight average molecular weight of about 400 to 30,000. This lactic acid oligomer can be produced by a conventionally known method, that is, by subjecting a lactic acid monomer to dehydration condensation at an appropriate heating temperature and reduced pressure. For example, lactic acid monomer is decompressed (generally 6 × 10
Heating (generally 120 to 170) under 2 to 1.5 × 10 4 Pa
℃) and dehydrated to obtain a weight average molecular weight of 400 ~
About 30,000 lactic acid oligomers can be obtained. In the present method, a lactic acid oligomer can be obtained from a lactic acid monomer as described above, and the depolymerization reaction can be carried out without removing the lactic acid oligomer. Lactic acid oligomer is L-lactic acid oligomer, D-lactic acid oligomer, D
Either an L-lactic acid oligomer or a lactic acid oligomer having an arbitrary D and L ratio may be used.
【０００８】本発明においては、塩化銅を乳酸オリゴマ
ーの重量に対し0.01〜５重量％添加することが好まし
い。このような添加量にすることにより、解重合反応の
際のラセミ化を抑えることができる。塩化銅の添加量が
乳酸オリゴマーに対し0.01重量％よりも少ないと、ラセ
ミ化を抑制する効果はほとんどなくなってしまう。一
方、塩化銅の添加量が乳酸オリゴマーに対し5.0 重量％
より多くするとラセミ化を抑制する効果がなくなるわけ
ではないが、その効果はほとんど変わらず、コスト高と
なり好ましくない。より好ましい塩化銅の添加量は乳酸
オリゴマーの重量に対し、０．０５〜２．０重量％であ
る。In the present invention, it is preferable that copper chloride is added in an amount of 0.01 to 5% by weight based on the weight of the lactic acid oligomer. With such an addition amount, racemization during the depolymerization reaction can be suppressed. If the addition amount of copper chloride is less than 0.01% by weight based on the lactic acid oligomer, the effect of suppressing racemization is almost lost. On the other hand, the amount of copper chloride added was 5.0%
If the amount is increased, the effect of suppressing racemization is not lost, but the effect hardly changes and the cost is increased, which is not preferable. A more preferable addition amount of copper chloride is 0.05 to 2.0% by weight based on the weight of the lactic acid oligomer.
【０００９】また、本発明では、塩化銅を添加する時期
は解重合反応を行う前であれば任意に設定できる。乳酸
モノマーから乳酸オリゴマーを得て、その乳酸オリゴマ
ーを取り出すことなしに、そのまま解重合反応を行う場
合には、乳酸モノマーに塩化銅を添加した後に乳酸オリ
ゴマーを得て、解重合反応を行っても何ら支障はない。
また、解重合反応を開始させる前に乳酸オリゴマーに塩
化銅を添加して、解重合反応を行っても何ら支障はな
い。In the present invention, the timing of adding copper chloride can be arbitrarily set as long as it is before the depolymerization reaction is performed. When a lactic acid oligomer is obtained from a lactic acid monomer and the depolymerization reaction is directly performed without removing the lactic acid oligomer, the lactic acid oligomer may be obtained after copper chloride is added to the lactic acid monomer, and the depolymerization reaction may be performed. No problem.
Further, there is no problem even if copper chloride is added to the lactic acid oligomer before the depolymerization reaction is started to perform the depolymerization reaction.
【００１０】また、本発明では、適切な解重合反応系の
温度は130 〜260 ℃程度であり、好ましくは140 〜250
℃であり、さらに好ましくは150 〜200 ℃である。解重
合反応系内の温度が130 ℃よりも低いと、反応が進行し
にくく、一方、解重合反応系内の温度が260 ℃よりも高
いと、着色が起こるので好ましくない。In the present invention, a suitable temperature of the depolymerization reaction system is about 130 to 260 ° C., preferably 140 to 250 ° C.
C., more preferably 150 to 200.degree. If the temperature in the depolymerization reaction system is lower than 130 ° C., the reaction hardly proceeds. On the other hand, if the temperature in the depolymerization reaction system is higher than 260 ° C., coloring occurs, which is not preferable.
【００１１】本発明においては、解重合反応系での圧力
に制限はないが、実用的には圧力を低く保つことが好ま
しい。通常は圧力を大気圧（1.013 ×105 Pa）以下にす
ることが好ましく、1.5 ×104 Pa以下にすることがより
好ましい。その理由は反応系の圧力が高ければ高いほ
ど、解重合反応により生成したラクチドが気化しにくく
なり、効率が悪くなるからである。一方、解重合反応系
の圧力の下限については、圧力が低いほど反応性の点で
は望ましいが、低い圧力を達成するためには高真空装置
を必要とし、また、高真空系で運転すれば、配管中の詰
まりなどが生じやすくなり、実プラントには不向きであ
る。したがって、本方法では、解重合反応系内の圧力を
５×10〜1.013 ×105 Paとすることが適切であり、５×
102 〜1.5×104 とすることが好ましい。In the present invention, the pressure in the depolymerization reaction system is not limited, but practically it is preferable to keep the pressure low. Normally, the pressure is preferably set to an atmospheric pressure (1.013 × 10 5 Pa) or lower, more preferably 1.5 × 10 4 Pa or lower. The reason is that the higher the pressure of the reaction system, the more difficult it is to vaporize the lactide generated by the depolymerization reaction, and the lower the efficiency. On the other hand, as for the lower limit of the pressure of the depolymerization reaction system, the lower the pressure, the more desirable in terms of reactivity. The clogging of the piping is likely to occur, which is not suitable for an actual plant. Therefore, in this method, it is appropriate that the pressure in the depolymerization reaction system is 5 × 10 to 1.013 × 10 5 Pa,
It is preferable to be 10 2 to 1.5 × 10 4 .
【００１２】本発明の方法においては、一般に解重合用
触媒を用いることができる。解重合用触媒としては特に
限定されるものではないが、通常、周期律表ＩＡ族、II
I Ａ族、IVＡ族、IIＢ族、IVＢ族、およびＶＡ族からな
る群から選ばれる金属または金属化合物からなる触媒を
用いることができる。In the method of the present invention, a depolymerization catalyst can generally be used. The depolymerization catalyst is not particularly limited, but is usually a group IA or II of the periodic table.
A catalyst comprising a metal or a metal compound selected from the group consisting of Group IA, Group IVA, Group IIB, Group IVB, and Group VA can be used.
【００１３】ＩＡ族に属するものとしては、たとえば、
アルカリ金属の水酸化物（たとえば、水酸化ナトリウ
ム、水酸化カリウム、水酸化リチウム等）、アルカリ金
属と弱酸の塩（たとえば、乳酸ナトリウム、酢酸ナトリ
ウム、炭酸ナトリウム、オクチル酸ナトリウム、ステア
リン酸ナトリウム、乳酸カリウム、酢酸カリウム、オク
チル酸カリウム等）、アルカリ金属のアルコキシド（た
とえば、ナトリウムメトキシド、カリウムメトキシド、
ナトリウムエトキシド、カリウムエトキシド等）、等を
あげることができる。As members of the IA family, for example,
Hydroxides of alkali metals (eg, sodium hydroxide, potassium hydroxide, lithium hydroxide, etc.), salts of alkali metals and weak acids (eg, sodium lactate, sodium acetate, sodium carbonate, sodium octylate, sodium stearate, lactic acid) Potassium, potassium acetate, potassium octylate, etc.), alkoxides of alkali metals (eg, sodium methoxide, potassium methoxide,
Sodium ethoxide, potassium ethoxide, etc.).
【００１４】III Ａ族に属するものとしては、たとえ
ば、アルミニウムエトキシド、アルミニウムプロポキシ
ド、酸化アルミニウム、塩化アルミニウム等をあげるこ
とができる。Examples of those belonging to Group IIIA include aluminum ethoxide, aluminum propoxide, aluminum oxide, aluminum chloride and the like.
【００１５】IVＡ族に属するものとしては、たとえば、
有機スズ系の触媒（たとえば、乳酸スズ、酒石酸スズ、
ジカプリル酸スズ、ジラウリル酸スズ、ジパルミチン酸
スズ、ジステアリン酸スズ、ジオレイン酸スズ、α−ナ
フトエ酸スズ、β−ナフトエ酸スズ、オクチル酸スズ
等）のほか、粉末スズ、酸化スズ、ハロゲン化スズ、等
をあげることができる。As members belonging to the IVA group, for example,
Organotin-based catalysts (for example, tin lactate, tin tartrate,
Tin dicaprylate, tin dilaurate, tin dipalmitate, tin distearate, tin dioleate, tin α-naphthoate, tin β-naphthoate, tin octylate, etc.), powdered tin, tin oxide, tin halide , Etc. can be given.
【００１６】IIＢ族に属するものとしては、たとえば、
亜鉛末、ハロゲン化亜鉛、酸化亜鉛、有機亜鉛系化合物
等をあげることができる。IVＢ族に属するものとして
は、たとえば、テトラプロピルチタネート等のチタン系
化合物、ジルコニウムイソプロポキシド等のジルコニウ
ム系化合物等をあげることができる。As members belonging to the IIB group, for example,
Zinc powder, zinc halide, zinc oxide, organic zinc compounds and the like can be mentioned. Examples of those belonging to Group IVB include titanium compounds such as tetrapropyl titanate, zirconium compounds such as zirconium isopropoxide, and the like.
【００１７】ＶＡ族に属するものとしては、たとえば、
三酸化アンチモン等のアンチモン系化合物、酸化ビスマ
ス（III ）等のビスマス系化合物をあげることができ
る。As members belonging to the VA group, for example,
Antimony compounds such as antimony trioxide and bismuth compounds such as bismuth (III) oxide can be mentioned.
【００１８】これらの中でも、スズ、またはスズ化合物
からなる触媒が活性の点から好ましく、オクチル酸スズ
が特に好ましい。これら触媒の使用量は、原料の乳酸オ
リゴマーに対して0.05〜20重量％、好ましくは0.1 〜10
重量％程度である。Of these, a catalyst comprising tin or a tin compound is preferred from the viewpoint of activity, and tin octylate is particularly preferred. These catalysts are used in an amount of 0.05 to 20% by weight, preferably 0.1 to 10% by weight, based on the starting lactic acid oligomer.
% By weight.
【００１９】なお、本発明の製造方法により得られるラ
クチドは、光学純度が９３％以上を有する。The lactide obtained by the production method of the present invention has an optical purity of 93% or more.
【００２０】[0020]
【発明の実施の形態】次に、本発明の方法を実施するた
めの装置について説明する。図１は典型的な装置構成例
を示す概略図である。図１において例えばフラスコから
なる解重合反応器（１）は、攪拌機（２）を有する縦型
反応器であり、温度調節機能を有する。本方法ではこの
反応器に原料の乳酸オリゴマーを仕込む。あるいは、こ
の反応器（１）中に乳酸モノマーを仕込み、脱水縮合さ
せて乳酸オリゴマーを得て、この乳酸オリゴマーを原料
として用いてもよい。また、導管（３）を通して乳酸オ
リゴマーを連続的に供給し、解重合反応を連続的に行わ
せてもよい。DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an apparatus for carrying out the method of the present invention will be described. FIG. 1 is a schematic diagram showing an example of a typical apparatus configuration. In FIG. 1, a depolymerization reactor (1) composed of, for example, a flask is a vertical reactor having a stirrer (2) and has a temperature control function. In this method, a raw material lactic acid oligomer is charged into this reactor. Alternatively, a lactic acid monomer may be charged into the reactor (1) and subjected to dehydration condensation to obtain a lactic acid oligomer, and the lactic acid oligomer may be used as a raw material. Alternatively, the lactic acid oligomer may be continuously supplied through the conduit (3) to continuously perform the depolymerization reaction.
【００２１】導管（４）は、反応器（１）内で生成した
ラクチド蒸気を反応器（１）外に送り出し、凝縮器
（５）に導くものである。この導管（４）は、加熱され
ているかまたは断熱されている。凝縮器（５）での凝縮
物は受器（６）で捕集される。凝縮器には、必要に応じ
て真空ポンプ（７）が接続され、反応系内の減圧を行う
ことができるようになっている。本方法では、凝縮器に
供給する冷媒の温度を、解重合反応系内の操作圧力に応
じ、ラクチドが凝縮する温度にすることが望ましい。The conduit (4) is for sending the lactide vapor generated in the reactor (1) out of the reactor (1) and leading it to the condenser (5). This conduit (4) is heated or insulated. Condensate in the condenser (5) is collected in the receiver (6). A vacuum pump (7) is connected to the condenser, if necessary, so that the pressure in the reaction system can be reduced. In the present method, it is desirable that the temperature of the refrigerant supplied to the condenser be a temperature at which lactide condenses according to the operating pressure in the depolymerization reaction system.
【００２２】本発明の方法によれば、解重合反応系内に
塩化銅を添加して乳酸オリゴマーの解重合を行うことに
より、乳酸オリゴマー、さらにはラクチドのラセミ化を
抑制することができる。このため、本方法では、塩化銅
を添加しない場合に比べ、より高い光学純度のラクチド
生成物を得ることができる。すなわち、原料の乳酸オリ
ゴマーとして、Ｌ−乳酸オリゴマーあるいはＤ−乳酸オ
リゴマーを用いた場合には、それらの光学純度に応じ
て、高光学純度のラクチド生成物を得ることができる。According to the method of the present invention, racemization of lactic acid oligomers and lactide can be suppressed by adding copper chloride to the depolymerization reaction system and depolymerizing lactic acid oligomers. Therefore, in the present method, a lactide product having higher optical purity can be obtained as compared with the case where copper chloride is not added. That is, when an L-lactic acid oligomer or a D-lactic acid oligomer is used as a raw material lactic acid oligomer, a lactide product having a high optical purity can be obtained according to their optical purity.
【００２３】[0023]
【実施例】以下、実施例により本発明をさらに具体的に
説明する。乳酸オリゴマーの重量平均分子量は、以下の
条件のＧＰＣ（ゲル浸透クロマトグラフィー）により、
ポリスチレン標準サンプルとの比較で求めた。検出器：
ＲＩＤ−６Ａ、ポンプ：ＬＣ−９Ａ、カラムオーブン：
ＣＴＯ−６Ａ、カラム：Shim-pack GPC-801C,-804C,-80
6C,-8025C を直列（島津製作所製）、移動相：クロロホ
ルム、流速：１ml/min、サンプル量：200 μl （サンプ
ル濃度が0.5w/w％となるようにクロロホルムに溶かし
た）、カラム温度：40℃。The present invention will be described more specifically with reference to the following examples. The weight average molecular weight of the lactic acid oligomer was determined by GPC (gel permeation chromatography) under the following conditions.
It was determined by comparison with a polystyrene standard sample. Detector:
RID-6A, pump: LC-9A, column oven:
CTO-6A, column: Shim-pack GPC-801C, -804C, -80
6C, -8025C in series (manufactured by Shimadzu Corporation), mobile phase: chloroform, flow rate: 1 ml / min, sample volume: 200 μl (dissolved in chloroform so that the sample concentration becomes 0.5 w / w%), column temperature: 40 ° C.
【００２４】［実施例１］ （乳酸オリゴマーの合成）光学純度98.5％のＬ−乳酸
（PH90、PURAC 社製）を温度160 ℃、圧力1.3 ×103Pa
の条件で脱水することにより、重量平均分子量1500の乳
酸オリゴマーを合成した。得られたオリゴマーの光学純
度は98.0％であった。Example 1 (Synthesis of lactic acid oligomer) L-lactic acid (PH90, manufactured by PURAC) having an optical purity of 98.5% was prepared at a temperature of 160 ° C. under a pressure of 1.3 × 10 3 Pa.
The lactic acid oligomer having a weight average molecular weight of 1500 was synthesized by dehydration under the following conditions. The optical purity of the obtained oligomer was 98.0%.
【００２５】（塩化銅によるラセミ化抑制の効果）試験
管に上記で得られた乳酸オリゴマーを５ｇ仕込み、乳酸
オリゴマーの解重合の際に触媒として用いられるオクチ
ル酸スズ0.025 ｇと、塩化銅0.01ｇを加え、200 ℃のヒ
ーティングブロック内で約20時間加熱した。加熱終了
後、試験管内の乳酸オリゴマーの光学純度を測定したと
ころ、73.1％であった。(Effect of Racemization Inhibition by Copper Chloride) A test tube was charged with 5 g of the lactic acid oligomer obtained above, and 0.025 g of tin octylate used as a catalyst in depolymerization of the lactic acid oligomer and 0.01 g of copper chloride were used. And heated in a heating block at 200 ° C. for about 20 hours. After the heating was completed, the optical purity of the lactic acid oligomer in the test tube was measured, and was 73.1%.
【００２６】［比較例１］ （乳酸オリゴマーの合成）光学純度98.5％のＬ−乳酸
（PH90、PURAC 社製）を温度160 ℃、圧力1.3 ×103Pa
の条件で脱水することにより、重量平均分子量1500の乳
酸オリゴマーを合成した。得られたオリゴマーの光学純
度は98.0％であった。Comparative Example 1 (Synthesis of lactic acid oligomer) L-lactic acid (PH90, manufactured by PURAC) having an optical purity of 98.5% was prepared at a temperature of 160 ° C. and a pressure of 1.3 × 10 3 Pa.
The lactic acid oligomer having a weight average molecular weight of 1500 was synthesized by dehydration under the following conditions. The optical purity of the obtained oligomer was 98.0%.
【００２７】（塩化銅によるラセミ化抑制の効果）試験
管に上記で得られた乳酸オリゴマーを５ｇ仕込み、乳酸
オリゴマーの解重合の際に触媒として用いられるオクチ
ル酸スズ0.025 ｇを加えた。ここには、塩化銅を加えず
に、200 ℃のヒーティングブロック内で約20時間加熱し
た。加熱終了後、試験管内の乳酸オリゴマーの光学純度
を測定したところ、48.4％であった。 ［実施例２］ （乳酸オリゴマーの合成）光学純度98.5％のＬ−乳酸
（PH90、PURAC 社製）を温度160 ℃、圧力1.3 ×103Pa
の条件で脱水することにより、重量平均分子量1500の乳
酸オリゴマーを合成した。得られたオリゴマーの光学純
度は98.0％であった。(Effect of Racemization Inhibition by Copper Chloride) A test tube was charged with 5 g of the lactic acid oligomer obtained above, and 0.025 g of tin octylate used as a catalyst in the depolymerization of the lactic acid oligomer was added. It was heated in a heating block at 200 ° C. for about 20 hours without adding copper chloride. After the completion of the heating, the optical purity of the lactic acid oligomer in the test tube was measured and found to be 48.4%. Example 2 (Synthesis of lactic acid oligomer) L-lactic acid (PH90, manufactured by PURAC) having an optical purity of 98.5% was prepared at a temperature of 160 ° C. and a pressure of 1.3 × 10 3 Pa.
The lactic acid oligomer having a weight average molecular weight of 1500 was synthesized by dehydration under the following conditions. The optical purity of the obtained oligomer was 98.0%.
【００２８】（乳酸オリゴマーの解重合）図１に示すの
と同様の構成の反応装置を用いた。容量500 ｍｌのフラ
スコ内の温度200 ℃、圧力1.3 ×103 Paに設定し、ま
た、凝縮器（５）を氷浴中にて冷却した。フラスコに上
記で得られた乳酸オリゴマーを400 ｇ仕込み、触媒とし
てオクチル酸スズ３ｇと、ラセミ化抑制剤として塩化銅
２ｇを加え、真空ポンプ（７）で減圧を開始した。約２
時間３０分経過した後、運転を停止した。凝縮器５での
凝縮物として着色のないラクチドが377 ｇ得られ、この
ラクチドの光学純度は96.5％であった。(Depolymerization of Lactic Acid Oligomers) A reaction apparatus having the same configuration as that shown in FIG. 1 was used. The temperature in the flask having a capacity of 500 ml was set to 200 ° C., the pressure was set to 1.3 × 10 3 Pa, and the condenser (5) was cooled in an ice bath. A flask was charged with 400 g of the lactic acid oligomer obtained above, 3 g of tin octylate as a catalyst and 2 g of copper chloride as a racemization inhibitor were added, and the pressure was reduced with a vacuum pump (7). About 2
After a lapse of 30 minutes, the operation was stopped. As a condensate in the condenser 5, 377 g of colorless lactide was obtained, and the optical purity of the lactide was 96.5%.
【００２９】［比較例２］ （乳酸オリゴマーの合成）光学純度98.5％のＬ−乳酸
（PH90、PURAC 社製）を温度160 ℃、圧力1.3 ×103Pa
の条件で脱水することにより、重量平均分子量1500の乳
酸オリゴマーを合成した。得られたオリゴマーの光学純
度は98.0％であった。Comparative Example 2 (Synthesis of lactic acid oligomer) L-lactic acid (PH90, manufactured by PURAC) having an optical purity of 98.5% was prepared at a temperature of 160 ° C. under a pressure of 1.3 × 10 3 Pa.
The lactic acid oligomer having a weight average molecular weight of 1500 was synthesized by dehydration under the following conditions. The optical purity of the obtained oligomer was 98.0%.
【００３０】（乳酸オリゴマーの解重合）図１に示すの
と同様の構成の反応装置を用いた。容量500 ｍｌのフラ
スコ内の温度200 ℃、圧力1.3 ×103 Paに設定し、ま
た、凝縮器（５）を氷浴中にて冷却した。フラスコに上
記で得られた乳酸オリゴマーを400 ｇ仕込み、触媒とし
てオクチル酸スズ３ｇを加え、真空ポンプ（７）で減圧
を開始した。約２時間３０分経過した後、運転を停止し
た。凝縮器５での凝縮物として着色のないラクチドが37
0 ｇ得られ、このラクチドの光学純度は91.0％であっ
た。(Depolymerization of Lactic Acid Oligomers) A reaction apparatus having the same structure as that shown in FIG. 1 was used. The temperature in the flask having a capacity of 500 ml was set to 200 ° C., the pressure was set to 1.3 × 10 3 Pa, and the condenser (5) was cooled in an ice bath. The flask was charged with 400 g of the lactic acid oligomer obtained above, 3 g of tin octylate was added as a catalyst, and the pressure was reduced by a vacuum pump (7). After about 2 hours and 30 minutes, the operation was stopped. Lactide without coloring as a condensate in the condenser 5 is 37
0 g was obtained, and the optical purity of this lactide was 91.0%.
【００３１】[0031]
【発明の効果】本発明のラクチドの製造方法によれば、
上述のように、解重合反応系に塩化銅を添加して乳酸オ
リゴマーの解重合を行うので、乳酸オリゴマー、さらに
は、乳酸オリゴマーを解重合して得られるラクチドのラ
セミ化を抑制することができる。その結果、特に、原料
として光学純度の高い乳酸オリゴマーを用いた場合に
は、高い光学純度を有するラクチドを効率よく製造する
ことができる。According to the method for producing lactide of the present invention,
As described above, since copper chloride is added to the depolymerization reaction system to depolymerize the lactic acid oligomer, it is possible to suppress the racemization of the lactic acid oligomer, and further, the lactide obtained by depolymerizing the lactic acid oligomer. . As a result, particularly when a lactic acid oligomer having high optical purity is used as a raw material, lactide having high optical purity can be efficiently produced.
【図１】本発明の方法を実施するための装置構成の一例
を示す概略図である。FIG. 1 is a schematic diagram showing an example of an apparatus configuration for performing a method of the present invention.
（１）：解重合反応器 （２）：攪拌機 （３）：導管 （４）：導管 （５）：凝縮器 （６）：受器 （７）：真空ポンプ (1): depolymerization reactor (2): stirrer (3): conduit (4): conduit (5): condenser (6): receiver (7): vacuum pump
───────────────────────────────────────────────────── フロントページの続き (72)発明者 小原 仁実 京都市中京区西ノ京桑原町１番地 株式会 社島津製作所三条工場内 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hitomi Ohara No. 1 Kuwabaracho, Nishinokyo, Nakagyo-ku, Kyoto Inside Shimazu Works Sanjo Plant
Claims (6)
チドの製造方法であって、解重合反応系に塩化銅を添加
し、所定の解重合温度、および圧力条件下で乳酸オリゴ
マーを解重合して、生成したラクチドを留出させるラク
チドの製造方法。1. A method for producing lactide by a depolymerization reaction of a lactic acid oligomer, comprising adding copper chloride to a depolymerization reaction system, depolymerizing the lactic acid oligomer at a predetermined depolymerization temperature and pressure conditions, A method for producing lactide, in which the produced lactide is distilled.
〜3000である請求項１に記載のラクチドの製造方法。2. The lactic acid oligomer has a weight average molecular weight of 400.
The method for producing lactide according to claim 1, wherein the lactide is from 3,000 to 3,000.
重量％添加する、請求項１または２に記載のラクチドの
製造方法3. The method according to claim 1, wherein copper chloride is used in an amount of 0.01 to 5 with respect to the lactic acid oligomer.
The method for producing lactide according to claim 1 or 2, wherein the lactide is added by weight%.
る、請求項１から３項のうちいずれか１項に記載のラク
チドの製造方法。4. The method for producing lactide according to claim 1, wherein the temperature of the depolymerization reaction system is from 130 to 260 ° C.
下である、請求項１〜４項のうちいずれか１項に記載の
ラクチドの製造方法。5. The method for producing lactide according to claim 1, wherein the pressure of the depolymerization reaction system is 1.013 × 10 5 Pa or less.
れた光学純度９３％以上のラクチド。6. A lactide having an optical purity of 93% or more produced by the production method according to claim 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP09627498A JP4003287B2 (en) | 1998-04-08 | 1998-04-08 | Method for producing lactide capable of suppressing racemization |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP09627498A JP4003287B2 (en) | 1998-04-08 | 1998-04-08 | Method for producing lactide capable of suppressing racemization |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH11292871A true JPH11292871A (en) | 1999-10-26 |
| JP4003287B2 JP4003287B2 (en) | 2007-11-07 |
Family
ID=14160573
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP09627498A Expired - Fee Related JP4003287B2 (en) | 1998-04-08 | 1998-04-08 | Method for producing lactide capable of suppressing racemization |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP4003287B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2003091238A1 (en) * | 2002-04-25 | 2003-11-06 | Haruo Nishida | Process for producing lactide |
| WO2004014890A1 (en) * | 2002-08-09 | 2004-02-19 | Kureha Tekunoenji K.K. | Method of purifying lactide |
-
1998
- 1998-04-08 JP JP09627498A patent/JP4003287B2/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2003091238A1 (en) * | 2002-04-25 | 2003-11-06 | Haruo Nishida | Process for producing lactide |
| WO2004014890A1 (en) * | 2002-08-09 | 2004-02-19 | Kureha Tekunoenji K.K. | Method of purifying lactide |
Also Published As
| Publication number | Publication date |
|---|---|
| JP4003287B2 (en) | 2007-11-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP0632807B1 (en) | Process for the production of cyclic esters from hydroxy acids and derivatives thereof | |
| US8258317B2 (en) | Catalyst for direct conversion of esters of lactic acid to lactide and the method for producing lactide using the same | |
| JP5030585B2 (en) | Process for producing aliphatic polyester with less residual cyclic ester | |
| JP4565278B2 (en) | Lactide synthesis method and lactide synthesis apparatus | |
| JP4075085B2 (en) | Method for producing lactide | |
| HK175595A (en) | Lactide production from dehydration of aqueous lactic acid feed | |
| JPWO2004033527A1 (en) | Method for producing aliphatic polyester | |
| CN106397389B (en) | A kind of technological method of synthesizing glycolide | |
| CN110511205B (en) | A kind of preparation method of high-purity glycolide | |
| CN110128397A (en) | A kind of preparation method of high-purity lactide | |
| JPH10109983A (en) | Method for producing cyclic ester and purification method | |
| JP4003287B2 (en) | Method for producing lactide capable of suppressing racemization | |
| EP2539332B1 (en) | Improved process for the preparation of l-lactide of high chemical yield and optical purity | |
| JPH0665230A (en) | Production of lactide | |
| JP4075089B2 (en) | Method for producing lactide | |
| CN113651794B (en) | Lactide synthesis method | |
| JPH1192475A (en) | Rapid production of lactide | |
| JPH1135579A (en) | Method for producing lactide using organic solvent | |
| KR20080018650A (en) | Optically pure lactide separation method | |
| JPH10306091A (en) | Method for producing lactide | |
| WO2012148108A2 (en) | Method for preparing lactide from alkyl lactate | |
| RU2576038C1 (en) | Method for glycolide obtaining | |
| JPH09110860A (en) | Lactide production method | |
| JPH10287668A (en) | Method for producing lactide and polylactic acid from ammonium lactate | |
| Stere et al. | Anionic and ionic coordinative polymerization of l‐lactide |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20070410 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20070412 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20070611 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20070731 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20070813 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100831 Year of fee payment: 3 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100831 Year of fee payment: 3 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110831 Year of fee payment: 4 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110831 Year of fee payment: 4 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120831 Year of fee payment: 5 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120831 Year of fee payment: 5 |
|
| S111 | Request for change of ownership or part of ownership |
Free format text: JAPANESE INTERMEDIATE CODE: R313113 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120831 Year of fee payment: 5 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120831 Year of fee payment: 5 |
|
| S111 | Request for change of ownership or part of ownership |
Free format text: JAPANESE INTERMEDIATE CODE: R313114 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120831 Year of fee payment: 5 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120831 Year of fee payment: 5 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130831 Year of fee payment: 6 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| LAPS | Cancellation because of no payment of annual fees |