JPS5829291B2 - 2,6- Naphthalene dicarbonate dimethyl ester - Google Patents
2,6- Naphthalene dicarbonate dimethyl esterInfo
- Publication number
- JPS5829291B2 JPS5829291B2 JP1630774A JP1630774A JPS5829291B2 JP S5829291 B2 JPS5829291 B2 JP S5829291B2 JP 1630774 A JP1630774 A JP 1630774A JP 1630774 A JP1630774 A JP 1630774A JP S5829291 B2 JPS5829291 B2 JP S5829291B2
- Authority
- JP
- Japan
- Prior art keywords
- dicarboxylic acid
- naphthalene dicarboxylic
- dimethyl ester
- ester
- acid dimethyl
- 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.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C67/00—Preparation of carboxylic acid esters
- C07C67/48—Separation; Purification; Stabilisation; Use of additives
- C07C67/52—Separation; Purification; Stabilisation; Use of additives by change in the physical state, e.g. crystallisation
- C07C67/54—Separation; Purification; Stabilisation; Use of additives by change in the physical state, e.g. crystallisation by distillation
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Crystallography & Structural Chemistry (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Vaporization, Distillation, Condensation, Sublimation, And Cold Traps (AREA)
Description
【発明の詳細な説明】
本発明は２・６−ナフタリンジカルボン酸ジメチルエス
テルの精製法に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for purifying 2,6-naphthalene dicarboxylic acid dimethyl ester.
更に詳しくは粗２・６−ナフタリンジカルボン酸ジメチ
ルエステルから、蒸留により高品質の２・６−ナフタリ
ンジカルボン酸ジメチルエステルを得る方法を提供しよ
うとするものである。More specifically, the present invention aims to provide a method for obtaining high quality 2,6-naphthalene dicarboxylic acid dimethyl ester by distillation from crude 2,6-naphthalene dicarboxylic acid dimethyl ester.
２・６−ナフタリンジカルボン酸ジメチルエステルは、
すぐれた物性を有するポリエステルであるポＩＪ フル
キレン−２・６−ナフタリンジカルボキシレートの原料
として有用である。2,6-naphthalene dicarboxylic acid dimethyl ester is
It is useful as a raw material for poIJ fullkylene-2,6-naphthalene dicarboxylate, which is a polyester with excellent physical properties.
従来、２・６−ナフタリンジカルボン酸ジメチルエステ
ルを得る方法として、例えば２・６−ジアルキルナフタ
リンを酸ｆヒして得られる２・６ナフタリンジカルボン
酸又は、ナフタリンモノカルボン酸及び／又は２・６−
以外のナフタリンジカルボン酸を、熱平均ｆヒ及び／又
は熱転位させて得られる２・６−ナフタリンジカルボン
酸をメタノールでエステル化する方法が知られている。Conventionally, as a method for obtaining 2,6-naphthalene dicarboxylic acid dimethyl ester, for example, 2,6-naphthalene dicarboxylic acid obtained by acid-fusing 2,6-dialkylnaphthalene, or naphthalene monocarboxylic acid and/or 2,6-
A method is known in which 2,6-naphthalene dicarboxylic acid obtained by subjecting other naphthalene dicarboxylic acids to thermal average f and/or thermal rearrangement is esterified with methanol.
ところが、このようにして得られた粗２・６−ナフタリ
ンジカルボン酸ジメチルエステルは、不純物のために黄
褐色を帯びている。However, the crude 2,6-naphthalene dicarboxylic acid dimethyl ester thus obtained has a yellowish brown color due to impurities.
このようなジメチルエステルをポリマーの原料として用
いると、ポリマーの色調も悪（製品の価値が低いので、
ジメチルエステルからこのような不純物を除去する必要
がある。If such dimethyl ester is used as a raw material for polymer, the color tone of the polymer will be poor (the value of the product will be low),
It is necessary to remove such impurities from dimethyl ester.
粗２・６−ナフタリンジカルボン酸ジメチルエステルの
精製にあたり、晶析、吸着、蒸留等、或はこれらを組合
せ実施することが考えられるが、テレフタル酸ジメチル
エステルにくらべ、？・６−ナフタリンジカルボン酸ジ
メチルエステルは融点が高いのみならず、種々の有機溶
媒に溶は難いので、吸着処理はその操作が煩雑となり、
晶析の場合は多量の溶媒が必要となる等の不利がある。In purifying crude 2,6-naphthalene dicarboxylic acid dimethyl ester, crystallization, adsorption, distillation, etc., or a combination of these may be carried out, but compared to terephthalic acid dimethyl ester, is it effective?・6-Naphthalene dicarboxylic acid dimethyl ester not only has a high melting point but also is difficult to dissolve in various organic solvents, making the adsorption treatment complicated.
In the case of crystallization, there are disadvantages such as the need for a large amount of solvent.
また蒸留の場合にも、テレフタル酸ジメチルエステルに
くらべてはるかに沸点が高いため、より高温、かつより
高真空で蒸留する必要がある。In addition, in the case of distillation, since it has a much higher boiling point than dimethyl terephthalate, it is necessary to distill it at a higher temperature and under a higher vacuum.
蒸留が高温で行なわれるため、蒸留中に２・６−ナフタ
リンジカルボン酸ジメチルエステルの熱分解により新た
に着色物やナフトエ酸メチル等の不純物を生じ、結局、
蒸留によっては高品質の２．６ナフタリンジカルボン酸
ジメチルエステルを得ることは困難であった。Since distillation is carried out at high temperatures, the thermal decomposition of 2,6-naphthalene dicarboxylic acid dimethyl ester generates new impurities such as colored substances and methyl naphthoate.
It was difficult to obtain high quality 2.6 naphthalene dicarboxylic acid dimethyl ester by distillation.
本発明者は、このような欠点のない２・６−ナフタリン
ジカルボン酸ジメチルエステルの蒸留精製法について鋭
意研究の結果、従来法のように工ステル［ヒの際その回
収率を高めるべく、可及的にエステル化率を高めたエス
テルｆヒ物を蒸留すると、着色物が留出する目的物中に
混入するが、むしろ成る程度エステル化率を低く抑えた
エステルｆヒ物を蒸留すると、高品質の目的物が得られ
ることを見出し、本発明に到達した。As a result of intensive research into a distillation purification method for 2,6-naphthalene dicarboxylic acid dimethyl ester that does not have such drawbacks, the present inventors have found that, in order to increase the recovery rate of 2,6-naphthalene dicarboxylic acid dimethyl ester, unlike the conventional method, If an ester compound with a high esterification rate is distilled, colored substances will be mixed into the target product, but if an ester compound with a low esterification rate is distilled, high quality The present invention has been achieved based on the discovery that the desired product can be obtained.
即ち、本発明は、粗２・６−ナフタリンジカルボン酸ジ
メチルエステルを蒸留により精製するにあたり、酸価１
〜５０の粗２・６−ナフタリンジカルボン酸ジメチルエ
ステルを蒸留することを特徴とする２・６−ナフタリン
ジカルボン酸ジメチルエステルの精製法である。That is, in the present invention, when purifying crude 2,6-naphthalene dicarboxylic acid dimethyl ester by distillation, the acid value is 1.
This is a method for purifying 2,6-naphthalene dicarboxylic acid dimethyl ester, which is characterized by distilling crude 2,6-naphthalene dicarboxylic acid dimethyl ester of ~50%.
本発明の精製方法に使用する粗２・６−ナフタリンジカ
ルボン酸ジメチルエステルは、如何なる方法により得ら
れたものでもよいが、例えば、前述した２・６−ジアル
キルナフタリンを酸化して得られる２・６−ナフタリン
ジカルボン酸又は、ナフタリンモノカルボン酸及び／若
しくは、２・６−以外のナフタリンジカルボン酸を、熱
不均化及び／若しくは、熱転位して得られる２・６−ナ
フタリンジカルボン酸を、公知の方法でメチルエステル
ｆヒしたもの等が、有利に用いられる。The crude 2,6-naphthalene dicarboxylic acid dimethyl ester used in the purification method of the present invention may be obtained by any method. - 2,6-naphthalene dicarboxylic acid obtained by thermal disproportionation and/or thermal rearrangement of naphthalene dicarboxylic acid or naphthalene monocarboxylic acid and/or naphthalene dicarboxylic acid other than 2,6- Methyl esters and the like are advantageously used.
本発明方法で原料とする粗２・６−ナフタリンジカルボ
ン酸ジメチルエステルは酸価１〜５０のものである。The crude 2,6-naphthalene dicarboxylic acid dimethyl ester used as a raw material in the method of the present invention has an acid value of 1 to 50.
好ましくは酸価２〜３０．特に好ましくは３〜２０のも
のを用いる。Preferably the acid value is 2-30. Particularly preferably, a number of 3 to 20 is used.
酸価が１より少いものを用いると、留出２・６−ナフタ
リンジカルボン酸ジメチルエステル中に着色不純物が混
入して充分精製されないので好ましくない。If an acid value of less than 1 is used, colored impurities will be mixed into the distilled 2,6-naphthalene dicarboxylic acid dimethyl ester and it will not be sufficiently purified, which is not preferable.
また酸価が５０よりも太きいものを用いると蒸留中に２
・６−ナフタリンジカルボン酸ジメチルエステルの熱分
解が著しくなり高揮発性のナフトエ酸メチルエステルを
多く副生ずるようになる。Also, if an acid value higher than 50 is used, 2
- Thermal decomposition of 6-naphthalene dicarboxylic acid dimethyl ester becomes remarkable, and a large amount of highly volatile naphthoic acid methyl ester is produced as a by-product.
ナフトエ酸メチルエステルの副生は２・６−ナフタリン
カルボン酸ジメチルエステルの損失を大きくするので好
ましくなく、また該ナフトエ酸メチルエステルは２・６
−ナフタリンジカルボン酸ジメチルエステルに比してよ
り揮発性であるので減圧蒸留装置の気液分離器で十分凝
縮することが難しく、それ故真空系統（例えば真空配管
、真空ポンプ等）へ吸引され該真空系統の能力を低下し
たり、或いは閉塞したりするので好ましくない。The by-product of naphthoic acid methyl ester is undesirable because it increases the loss of 2,6-naphthalenecarboxylic acid dimethyl ester, and the naphthoic acid methyl ester is
- Since it is more volatile than naphthalene dicarboxylic acid dimethyl ester, it is difficult to sufficiently condense it in the gas-liquid separator of a vacuum distillation device, and therefore it is sucked into the vacuum system (e.g., vacuum piping, vacuum pump, etc.). This is undesirable because it reduces the capacity of the system or blocks it.
更にまた、熱分解が著しくなると精製２・６−ナフタリ
ンジカルボン酸ジメチルエステルも着色する（着色度が
高くなる）ようになるので好ましくない。Furthermore, if the thermal decomposition becomes significant, purified 2,6-naphthalene dicarboxylic acid dimethyl ester will also become colored (the degree of coloring will increase), which is not preferable.
なお、ここにいう酸価とは試料１１中に含まれるカルボ
キシル基を中和するに必要なＫＯＨの■数を意味する。Note that the acid value herein means the number of KOH required to neutralize the carboxyl groups contained in Sample 11.
本発明方法で原料とする粗２・６−ナフタリンジカルボ
ン酸ジメチルエステルを得るには、２・６−ナフタリン
ジカルボン酸をメチルエステルｆヒする際に、完全にジ
メチルエステルｆヒせずに、少量の２・６−ナフタリン
ジカルボン酸及び／又は２・６−ナフタリンジカルボン
酸モノメチルエステルが残るようにすればよく、エステ
ルｆヒ反応中の、エステルｆヒ生成物の酸価を測定して
、好ましい値のところで反応を止めればよい。In order to obtain crude 2,6-naphthalene dicarboxylic acid dimethyl ester, which is used as a raw material in the method of the present invention, when methyl ester is added to 2,6-naphthalene dicarboxylic acid, a small amount of dimethyl ester is added without completely removing the dimethyl ester. It is only necessary to leave 2,6-naphthalene dicarboxylic acid and/or 2,6-naphthalene dicarboxylic acid monomethyl ester, and measure the acid value of the ester f product during the ester f reaction to find a preferable value. By the way, you can stop the reaction.
或は、エステルｆヒ生成物の酸価が低くなりすぎた場合
には、２・６−ナフタリンジカルボン酸及び／又は２・
６−ナフタリンジカルボン酸モノメチルエステルを添加
して酸価を調整してもよい。Alternatively, if the acid value of the ester product becomes too low, 2,6-naphthalene dicarboxylic acid and/or 2.
The acid value may be adjusted by adding 6-naphthalene dicarboxylic acid monomethyl ester.
蒸留に際しては、単蒸発よりも精留を行なう方が高品質
の２・６−ナフタリンジカルボン酸ジメチルエステルが
得られることは言うまでもない。It goes without saying that in distillation, higher quality 2,6-naphthalene dicarboxylic acid dimethyl ester can be obtained by performing rectification than by single evaporation.
蒸留温度の下限は、一般には２・６−ナフタリンジカル
ボン酸ジメチルエステルの融点である。The lower limit of the distillation temperature is generally the melting point of 2,6-naphthalene dicarboxylic acid dimethyl ester.
しかし、該エステルは低揮発性で、かかる低温では高真
空にすることが必要となるので、なるべく１９０℃以上
にするのが好ましい。However, since the ester has low volatility and a high vacuum is required at such low temperatures, the temperature is preferably 190° C. or higher.
また蒸留温度の上限は、２・６−ナフタリンジカルボン
酸ジメチルエステルの分解温度以下であればよい。Further, the upper limit of the distillation temperature may be below the decomposition temperature of 2,6-naphthalene dicarboxylic acid dimethyl ester.
該エステルの脱力ルギキシル化が３００℃以上で徐々に
生起するので、なるべく ３００ ’Ｃ以下にす°るの
がよい。Since the ester is slowly oxidized at temperatures above 300°C, it is preferable to keep the temperature below 300°C.
特に好ましい蒸留温度は２１０〜２８０℃である。A particularly preferred distillation temperature is 210-280°C.
蒸留は連続式でも回分式でも実施し得る。Distillation can be carried out either continuously or batchwise.
蒸留装置は公知のものでよく、例えば真空蒸発罐、棚段
式蒸留塔等を用い得る。The distillation apparatus may be a known one, such as a vacuum evaporation can, a tray distillation column, or the like.
蒸留に際して粗２・６−ナフタリンジカルボン酸ジメチ
ルエステル中に含有される遊離ジカルボン酸やモノメチ
ルエステルは高沸点成分として残留するので、蒸留装置
の罐出液（或は高沸点留分）は再度エステルｆヒエ程に
循環再使用することもできる。During distillation, the free dicarboxylic acid and monomethyl ester contained in the crude 2,6-naphthalene dicarboxylic acid dimethyl ester remain as high-boiling components, so the canned liquid (or high-boiling fraction) from the distillation apparatus is converted into ester f again. It can also be recycled and reused as much as barnyard grass.
本発明方法によれば、粗２・６−ナフタリンジカルボン
酸ジメチルエステルから、他の精製法では除去困難であ
った着色不純物を効率よく除去することができ、特に色
相のすぐれた２・６−ナフタリンジカルボン酸ジメチル
エステルを得ることができる。According to the method of the present invention, colored impurities that are difficult to remove by other purification methods can be efficiently removed from crude 2,6-naphthalene dicarboxylic acid dimethyl ester. Dicarboxylic acid dimethyl ester can be obtained.
またエステル化触媒の除去にも効果的である。It is also effective in removing esterification catalysts.
必要あれば、本発明方法を他の精製法（例えば溶媒を用
いて再結晶させる）と組合せ実施することもできる。If necessary, the method of the present invention can be carried out in combination with other purification methods (for example, recrystallization using a solvent).
以下実施例により本発明を詳述する。The present invention will be explained in detail with reference to Examples below.
比較例 １
２・６−シメチルナフタリンの空気酸ｆヒにより得られ
た粗２・６−ナフタリンジカルボン酸１重量部、メタノ
ール１５重量部およびエステル化触媒としての硫酸０．
１重量部を１３５℃で５時間反応させた結果、酸価０．
６８、着色度１．３８の粗２・６−ナフタリンジカルボ
ン酸ジメチルエステルを得た。Comparative Example 1 1 part by weight of crude 2,6-naphthalene dicarboxylic acid obtained by air acidification of 2,6-dimethylnaphthalene, 15 parts by weight of methanol, and 0.0 parts by weight of sulfuric acid as an esterification catalyst.
As a result of reacting 1 part by weight at 135°C for 5 hours, the acid value was 0.
68, crude 2,6-naphthalene dicarboxylic acid dimethyl ester having a coloring degree of 1.38 was obtained.
該粗２・６−ナフタリンジカルボン酸ジメチルエステル
を蒸留圧力３０ ｍｍＨｇ ａｂｓ 、 で単蒸留し
た結果塔頂留出物として得られた２・６−ナフタリンジ
カルボン酸ジメチルエステルはＭＯ３２１、着色度０．
１４であり黄味を帯びていた。As a result of simple distillation of the crude 2,6-naphthalene dicarboxylic acid dimethyl ester at a distillation pressure of 30 mmHg abs, the 2,6-naphthalene dicarboxylic acid dimethyl ester obtained as an overhead distillate had an MO of 321 and a coloring degree of 0.
14 and had a yellowish tinge.
（支）着色度：２・６ナフタリンジカルボン酸ジメチル
エステルをＯ−クロロフェノールニ濃度１０重量％にな
るように溶解したものを、長さｌＣｒｌ１のセルに充た
し、比較セルにＯ−クロロフェノールを充たし、日立分
光々度計モデル１０１を使用して波長５００ｍμで測定
した光学密度である。(Support) Coloring degree: 2.6 A cell with a length of 1Crl1 was filled with a solution of dimethyl naphthalene dicarboxylic acid ester to an O-chlorophenol concentration of 10% by weight, and a comparative cell was filled with O-chlorophenol. , is an optical density measured at a wavelength of 500 mμ using a Hitachi spectrophotometer model 101.
比較例 ２
２・６−シメチルナフタリンの空気酸ｆヒにより得られ
た粗２・６−ナフタリンジカルボン酸１重量部当りメタ
ノール３重量部の割合で攪拌式オー※〈トクレーブに入
れ、２６０℃で５時間反応させた後、冷却してから反応
物をとり出し、戸別して粗２・６−ナフタリンジカルボ
ン酸ジメチルエステルを得た。Comparative Example 2 2,6-dimethylnaphthalene was mixed with air at a ratio of 3 parts by weight of methanol per 1 part by weight of crude 2,6-naphthalene dicarboxylic acid obtained by air acidification in a stirred autoclave at 260°C. After reacting for 5 hours, the reaction mixture was cooled and then taken out and sent door to door to obtain crude 2,6-naphthalene dicarboxylic acid dimethyl ester.
このものの酸価は７５、着色度は１．４５であり、ナフ
トエ酸メチルエステルは含有されていなかった。This product had an acid value of 75, a coloring degree of 1.45, and did not contain naphthoic acid methyl ester.
上記反応で得られた粗２・６−ナフタリンジカルボン酸
ジメチルエステルの一部を蒸留した。A portion of the crude 2,6-naphthalene dicarboxylic acid dimethyl ester obtained in the above reaction was distilled.
蒸留条件は単蒸留で蒸留圧力３０ ｍｍＨｇ 、 ａｂ
ｓ 、で塔頂温度を２５５℃に保てるまで蒸留を続けた
結果、塔頂留出物として得られた２・６−ナフタリンジ
カルボン酸ジメチルエステルは、酸ｆヒ２７．５．着色
度０．１２であり、黄味を帯びていた。Distillation conditions were simple distillation, distillation pressure 30 mmHg, ab
Dimethyl ester of 2,6-naphthalene dicarboxylic acid obtained as an overhead distillate was obtained by continuing distillation until the top temperature could be maintained at 255°C at 27.5°C. The degree of coloration was 0.12, and it was yellowish.
その上、塔頂から留出が始まった頃より、気液分離器、
真空配管の内壁へ白色のナフトエ酸メチルエステルの固
形物が析出付着しはじめた。Moreover, since distillation started from the top of the tower, gas-liquid separators,
White naphthoic acid methyl ester solids began to precipitate and adhere to the inner walls of the vacuum piping.
そして約２０分後に配管の塞りが著しくなり、真空度の
低下が生じはじめた。After about 20 minutes, the piping became significantly clogged and the degree of vacuum began to decrease.
このため閉塞部を外部加熱してナフトエ酸メチルエステ
ルの固形物を溶融させて塞りを取り除きながら蒸留操作
を続げた。Therefore, the distillation operation was continued while the blockage was removed by externally heating the blockage to melt the naphthoic acid methyl ester solids.
この間ナフトエ酸メチルエステルが３．４％も副生じた
。During this time, 3.4% of naphthoic acid methyl ester was produced as a by-product.
実施例１〜４及び比較例３
比較例２のエステルｆヒ反応で得られた粗２・６ナフタ
リンジカルボン酸ジメチルエステルのエステル化触媒を
更に高めるために第１表に示す条件で更にエステルｆヒ
反応を行い得られたエステルを比較例２と同様に蒸留し
た。Examples 1 to 4 and Comparative Example 3 In order to further increase the esterification catalyst of the crude 2.6 naphthalene dicarboxylic acid dimethyl ester obtained in the ester f reaction of Comparative Example 2, ester f was further reacted under the conditions shown in Table 1. The ester obtained by the reaction was distilled in the same manner as in Comparative Example 2.
その結果を第１表に示す。The results are shown in Table 1.
実施例 ５
比較例３のメチルエステルｆヒで得られた粗２・６−ナ
フタリンジカルボン酸ジメチルエステル１重量部に則し
て２・６−ナフタリンジカルボン酸モノメチルエステル
０．０７重量部を添加し、酸価を１７．８にしたものを
比較例２と同様に蒸留した結果、酸価６．５９、着色度
０．０３１という着色物が極めてよく除去された２・６
−ナフタリンジカルボン酸ジメチルエステルをナフトエ
酸メチルエステルの発生もなく得ることができた。Example 5 0.07 parts by weight of 2,6-naphthalene dicarboxylic acid monomethyl ester was added to 1 part by weight of the crude 2,6-naphthalene dicarboxylic acid dimethyl ester obtained from methyl ester f of Comparative Example 3, As a result of distilling the product with an acid value of 17.8 in the same manner as in Comparative Example 2, colored substances with an acid value of 6.59 and a degree of coloration of 0.031 were removed extremely well.
- Naphthalene dicarboxylic acid dimethyl ester could be obtained without generation of naphthoic acid methyl ester.
比較例 ４
比較例３で蒸留精製した２・６−ナフタリンジカルボン
酸ジメチルエステルを更に蒸留したが着色物は殆んど除
去されず着色度０．０９１のやや黄味を帯びた２・６−
ナフタリンジカルボン酸ジメチルエステルが得られた。Comparative Example 4 The 2,6-naphthalene dicarboxylic acid dimethyl ester purified by distillation in Comparative Example 3 was further distilled, but almost no colored matter was removed, resulting in a slightly yellowish 2,6-naphthalene dicarboxylic acid with a degree of coloration of 0.091.
Naphthalene dicarboxylic acid dimethyl ester was obtained.
実施例 ６
実施例２の反応条件でメチルエステルｆヒされた粗２・
６−ナフタリンジカルボン酸ジメチルエステルを、多孔
板塔（段数１０段のもの）を用いて、塔頂圧力３０ ｍ
ｍＨｇ 、ａｂｓ、、塔頂温度２２５℃で連続式に減圧
精留して得た留出２・６−ナフタリンジカルボン酸ジメ
チルエステルは、酸価０３１３、着色度０．０１５とい
う極めて着色物の少いものであった。Example 6 Crude 2.
6-naphthalene dicarboxylic acid dimethyl ester was prepared using a perforated plate column (10 plates) at a column top pressure of 30 m.
mHg, abs, The distilled 2,6-naphthalene dicarboxylic acid dimethyl ester obtained by continuous vacuum rectification at a tower top temperature of 225°C has an acid value of 0313 and a coloration degree of 0.015, with very few colored substances. It was.
なお、精留に際し、ナフトエ酸メチルエステルの生成は
認められなかった。Note that during the rectification, no formation of naphthoic acid methyl ester was observed.
実施例 ７
比較例２の反応条件でメチルエステル１ヒされた粗２・
６−ナフタリンジカルボン酸ジメチルエステル１重量部
にメタノール１０重量部を加え、攪拌式オートクレーブ
中で、更に２６０℃で３時間エステル化させたところ、
酸価４．２、着色度１．４８の粗２・６−ナフタリンジ
カルボン酸ジメチルエステルを得た。Example 7 Crude 2.
10 parts by weight of methanol was added to 1 part by weight of 6-naphthalene dicarboxylic acid dimethyl ester, and esterification was further carried out at 260°C for 3 hours in a stirring autoclave.
Crude 2,6-naphthalenedicarboxylic acid dimethyl ester having an acid value of 4.2 and a coloring degree of 1.48 was obtained.
該エステルを、実施例６の精留条件と同じ条件で減圧精
留したところ、酸価０、 Ｏ６５、着色度０．０１７と
いう極めて着色の少い精製２・６−ナフタリンジカルボ
ン酸ジメチルエステルを得た。When the ester was rectified under reduced pressure under the same conditions as those in Example 6, purified dimethyl 2,6-naphthalene dicarboxylic acid ester with extremely little coloration, with an acid value of 0, O65, and a degree of coloration of 0.017, was obtained. Ta.
なお、精留に際し、ナフトエ酸メチルエステルの生成は
認められなかった。Note that during the rectification, no formation of naphthoic acid methyl ester was observed.
比較例 ５
比較例２の反応条件でメチルエステル化された粗２・６
−ナフタリンジカルボン酸ジメチルエステルを、実施例
６の精留条件と同じ条件で減圧精留したところ、酸価０
．５６５、着色間０．０５３の淡黄色精製２・６−ナフ
タリンジカルボン酸ジメチルエステルを得た。Comparative Example 5 Crude 2 and 6 methyl esterified under the reaction conditions of Comparative Example 2
- Naphthalene dicarboxylic acid dimethyl ester was rectified under reduced pressure under the same rectification conditions as in Example 6, and the acid value was 0.
．． 565 and a coloring interval of 0.053, pale yellow purified 2,6-naphthalenedicarboxylic acid dimethyl ester was obtained.
しかし、塔頂から留出が始まった頃より、気液分離器、
真空配管の内壁へ白色のナフトエ酸メチルエステルの固
形物が析出付着しはじめた。However, since distillation started from the top of the tower, gas-liquid separators,
White naphthoic acid methyl ester solids began to precipitate and adhere to the inner walls of the vacuum piping.
そして約４５分後に配管の塞りが著しくなり真空度の低
下が生じはじめた。After about 45 minutes, the piping became significantly clogged and the degree of vacuum began to decrease.
このためしばしば閉塞部の固形物を外部加熱で溶融させ
て塞りを取り除く必要があった。For this reason, it is often necessary to remove the blockage by melting the solid matter in the blockage by external heating.
そこで真空配管を加熱しながら蒸留操作を続げた。Therefore, the distillation operation continued while heating the vacuum piping.
比較例 ６
比較例３の反応条件でメチルエステル１ヒされた粗２・
６−ナフタリンジカルボン酸ジメチルエステルを、実施
例６の精留条件で減圧精留したところ、酸価０．０１２
、着色度０．１５という黄色味を帯びた２・６−ナフタ
リンジカルボン酸ジメチルエステルを得た。Comparative Example 6 Crude 2.
When 6-naphthalene dicarboxylic acid dimethyl ester was rectified under reduced pressure under the rectification conditions of Example 6, the acid value was 0.012.
, yellowish 2,6-naphthalene dicarboxylic acid dimethyl ester with a coloring degree of 0.15 was obtained.
精留に際し、ナフトエ酸メチルエステルは検出されなか
った。No naphthoic acid methyl ester was detected during rectification.
比較例 ７
２・６−シメチルナフタリンの空気酸ｆヒにより得られ
た粗２・６−ナフタリンジカルボン酸１重量部当りメタ
ノール３重量部の割合で攪拌式オートクレーブに入れ、
２６０℃で５．２時間反応させた後、冷却してから反応
物をとり出し、１別して粗２・６−ナフタリンジカルボ
ン酸ジメチルエステルを得た。Comparative Example 7 2,6-dimethylnaphthalene was placed in a stirred autoclave at a ratio of 3 parts by weight of methanol per 1 part by weight of crude 2,6-naphthalene dicarboxylic acid obtained by air acid f.
After reacting at 260° C. for 5.2 hours, the reaction product was taken out after cooling and separated into portions to obtain crude 2,6-naphthalene dicarboxylic acid dimethyl ester.
このものの酸価は５４、着色度は１．４３であり、ナフ
トエ酸メチルエステルは含有されていなかった。This product had an acid value of 54, a coloring degree of 1.43, and did not contain naphthoic acid methyl ester.
上記反応で得られた粗２・６−ナフタリンジカルボン酸
ジメチルエステルの一部を蒸留した。A portion of the crude 2,6-naphthalene dicarboxylic acid dimethyl ester obtained in the above reaction was distilled.
蒸留条件は単蒸留で蒸留圧力３０ ｍｍＨｇ ａｂｓ
、で塔頂温度を２５５℃に保てるまで蒸留を続けた結果
、塔頂留出物として得られた２・６−ナフタリンジカル
ボン酸ジメチルエステルは、酸化１８．１、着色度０．
０８６であり、黄味を帯びていた。Distillation conditions are simple distillation, distillation pressure 30 mmHg abs
Dimethyl ester of 2,6-naphthalene dicarboxylic acid obtained as a column overhead distillate was distilled until the top temperature could be maintained at 255°C.The oxidation rate was 18.1, and the degree of coloration was 0.
086 and had a yellowish tinge.
その上ナフトエ酸メチルエステルが０．５％（重量）も
生成していた。Moreover, 0.5% (by weight) of naphthoic acid methyl ester was produced.
また、気液分離器や真空配管の器壁にナフトエ酸メチル
エステルの一部が凝固していた。Additionally, some naphthoic acid methyl ester had solidified on the walls of the gas-liquid separator and vacuum piping.
実施例 ８
比較例７のメチルエステルｆヒで得られた粗２・６−ナ
フタリンジカルボン酸ジメチルエステル１重量部に対し
て精製２・６−ナフタリンジカルボン酸ジメチルエステ
ル０．２２重量部を添加し、酸価４４，３、着色度１１
７のものを得た。Example 8 0.22 parts by weight of purified 2,6-naphthalene dicarboxylic acid dimethyl ester was added to 1 part by weight of the crude 2,6-naphthalene dicarboxylic acid dimethyl ester obtained from methyl ester f of Comparative Example 7, Acid value 44.3, coloring degree 11
I got 7 things.
このものを比較例７と同様に蒸留した結果、酸価１４．
５、着色度０．０３９という着色物のよく除去された２
・６−ナフタリンジカルボン酸ジメチルエステルを得る
ことができた。As a result of distilling this product in the same manner as in Comparative Example 7, the acid value was 14.
5. Colored matter was well removed with a degree of coloration of 0.039.
- 6-naphthalene dicarboxylic acid dimethyl ester could be obtained.
またナフトエ酸メチルエステルの含有率はＯ，ＯＳ％の
わずかであった。Further, the content of naphthoic acid methyl ester was only a small amount of O and OS%.
Claims (1)
ルを蒸留により精製するにあたり、酸価１〜５０の粗２
・６−ナフタリンジカルボン酸ジメチルエステルを蒸留
することを特徴とする２・６ナフタリンジカルボン酸ジ
メチルエステルの精製法。1 In purifying crude 2,6-naphthalene dicarboxylic acid dimethyl ester by distillation, crude 2 with an acid value of 1 to 50 is used.
- A method for purifying 2,6-naphthalene dicarboxylic acid dimethyl ester, which comprises distilling 6-naphthalene dicarboxylic acid dimethyl ester.
Priority Applications (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1630774A JPS5829291B2 (en) | 1974-02-12 | 1974-02-12 | 2,6- Naphthalene dicarbonate dimethyl ester |
| GB601075A GB1464241A (en) | 1974-02-12 | 1975-02-12 | Purification of aromatic esters |
| FR7504302A FR2260561B1 (en) | 1974-02-12 | 1975-02-12 | |
| DE19752505831 DE2505831C3 (en) | 1974-02-12 | 1975-02-12 | Process for the purification of crude dimethyl 2,6-naphthalenedicarboxylate |
| US05/725,834 US4048021A (en) | 1974-02-12 | 1976-09-23 | Method of purifying crude 2,6-naphthalenedicarboxylic acid dimethyl ester |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1630774A JPS5829291B2 (en) | 1974-02-12 | 1974-02-12 | 2,6- Naphthalene dicarbonate dimethyl ester |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS50108248A JPS50108248A (en) | 1975-08-26 |
| JPS5829291B2 true JPS5829291B2 (en) | 1983-06-22 |
Family
ID=11912867
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1630774A Expired JPS5829291B2 (en) | 1974-02-12 | 1974-02-12 | 2,6- Naphthalene dicarbonate dimethyl ester |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JPS5829291B2 (en) |
| DE (1) | DE2505831C3 (en) |
| FR (1) | FR2260561B1 (en) |
| GB (1) | GB1464241A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5868226U (en) * | 1981-11-04 | 1983-05-10 | 伊藤 公政 | Ham, sausage, kamaboko, etc. with a hole in the center |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5095135A (en) * | 1990-04-05 | 1992-03-10 | Sumikin Chemical Co., Ltd. | Process for the preparation of high-purity naphthalenecarboxylic acid esters |
-
1974
- 1974-02-12 JP JP1630774A patent/JPS5829291B2/en not_active Expired
-
1975
- 1975-02-12 GB GB601075A patent/GB1464241A/en not_active Expired
- 1975-02-12 DE DE19752505831 patent/DE2505831C3/en not_active Expired
- 1975-02-12 FR FR7504302A patent/FR2260561B1/fr not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5868226U (en) * | 1981-11-04 | 1983-05-10 | 伊藤 公政 | Ham, sausage, kamaboko, etc. with a hole in the center |
Also Published As
| Publication number | Publication date |
|---|---|
| DE2505831A1 (en) | 1975-08-14 |
| GB1464241A (en) | 1977-02-09 |
| FR2260561A1 (en) | 1975-09-05 |
| DE2505831C3 (en) | 1979-03-15 |
| FR2260561B1 (en) | 1978-10-06 |
| JPS50108248A (en) | 1975-08-26 |
| DE2505831B2 (en) | 1978-07-13 |
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