JPH04221340A - Production of highly pure isophthalic acid - Google Patents
Production of highly pure isophthalic acidInfo
- Publication number
- JPH04221340A JPH04221340A JP41183890A JP41183890A JPH04221340A JP H04221340 A JPH04221340 A JP H04221340A JP 41183890 A JP41183890 A JP 41183890A JP 41183890 A JP41183890 A JP 41183890A JP H04221340 A JPH04221340 A JP H04221340A
- Authority
- JP
- Japan
- Prior art keywords
- isophthalic acid
- methanol
- acid
- purity
- crude
- 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.)
- Pending
Links
- QQVIHTHCMHWDBS-UHFFFAOYSA-N isophthalic acid Chemical compound OC(=O)C1=CC=CC(C(O)=O)=C1 QQVIHTHCMHWDBS-UHFFFAOYSA-N 0.000 title claims abstract description 120
- 238000004519 manufacturing process Methods 0.000 title claims description 11
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 claims abstract description 87
- KKEYFWRCBNTPAC-UHFFFAOYSA-N Terephthalic acid Chemical compound OC(=O)C1=CC=C(C(O)=O)C=C1 KKEYFWRCBNTPAC-UHFFFAOYSA-N 0.000 claims abstract description 36
- 239000002904 solvent Substances 0.000 claims abstract description 13
- 239000012535 impurity Substances 0.000 abstract description 11
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 18
- 238000000034 method Methods 0.000 description 14
- 239000002994 raw material Substances 0.000 description 13
- 238000001953 recrystallisation Methods 0.000 description 10
- 238000010438 heat treatment Methods 0.000 description 8
- 238000007254 oxidation reaction Methods 0.000 description 8
- WPYMKLBDIGXBTP-UHFFFAOYSA-N benzoic acid Chemical compound OC(=O)C1=CC=CC=C1 WPYMKLBDIGXBTP-UHFFFAOYSA-N 0.000 description 6
- 230000003647 oxidation Effects 0.000 description 6
- 239000007787 solid Substances 0.000 description 6
- CTQNGGLPUBDAKN-UHFFFAOYSA-N O-Xylene Chemical compound CC1=CC=CC=C1C CTQNGGLPUBDAKN-UHFFFAOYSA-N 0.000 description 5
- 239000007791 liquid phase Substances 0.000 description 5
- URLKBWYHVLBVBO-UHFFFAOYSA-N Para-Xylene Chemical group CC1=CC=C(C)C=C1 URLKBWYHVLBVBO-UHFFFAOYSA-N 0.000 description 4
- 239000003054 catalyst Substances 0.000 description 4
- IVSZLXZYQVIEFR-UHFFFAOYSA-N m-xylene Chemical group CC1=CC=CC(C)=C1 IVSZLXZYQVIEFR-UHFFFAOYSA-N 0.000 description 4
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 3
- 239000005711 Benzoic acid Substances 0.000 description 3
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 3
- YNQLUTRBYVCPMQ-UHFFFAOYSA-N Ethylbenzene Chemical compound CCC1=CC=CC=C1 YNQLUTRBYVCPMQ-UHFFFAOYSA-N 0.000 description 3
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 3
- 235000010233 benzoic acid Nutrition 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 3
- 238000001816 cooling Methods 0.000 description 3
- 238000000605 extraction Methods 0.000 description 3
- 239000012046 mixed solvent Substances 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 2
- 239000012141 concentrate Substances 0.000 description 2
- 238000004090 dissolution Methods 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 229920000728 polyester Polymers 0.000 description 2
- 238000000746 purification Methods 0.000 description 2
- 238000010992 reflux Methods 0.000 description 2
- JHJLBTNAGRQEKS-UHFFFAOYSA-M sodium bromide Chemical compound [Na+].[Br-] JHJLBTNAGRQEKS-UHFFFAOYSA-M 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 239000008096 xylene Substances 0.000 description 2
- PQLVXDKIJBQVDF-UHFFFAOYSA-N acetic acid;hydrate Chemical compound O.CC(O)=O PQLVXDKIJBQVDF-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 150000001491 aromatic compounds Chemical class 0.000 description 1
- 150000004945 aromatic hydrocarbons Chemical class 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 125000004432 carbon atom Chemical group C* 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- BZRRQSJJPUGBAA-UHFFFAOYSA-L cobalt(ii) bromide Chemical compound Br[Co]Br BZRRQSJJPUGBAA-UHFFFAOYSA-L 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000008025 crystallization Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- RJYMRRJVDRJMJW-UHFFFAOYSA-L dibromomanganese Chemical compound Br[Mn]Br RJYMRRJVDRJMJW-UHFFFAOYSA-L 0.000 description 1
- 239000000706 filtrate Substances 0.000 description 1
- 238000007429 general method Methods 0.000 description 1
- SYSQUGFVNFXIIT-UHFFFAOYSA-N n-[4-(1,3-benzoxazol-2-yl)phenyl]-4-nitrobenzenesulfonamide Chemical class C1=CC([N+](=O)[O-])=CC=C1S(=O)(=O)NC1=CC=C(C=2OC3=CC=CC=C3N=2)C=C1 SYSQUGFVNFXIIT-UHFFFAOYSA-N 0.000 description 1
- 229940078552 o-xylene Drugs 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000012265 solid product Substances 0.000 description 1
- 150000003738 xylenes Chemical class 0.000 description 1
Landscapes
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
Description
【０００１】0001
【産業上の利用分野】本発明は、高純度イソフタル酸の
製造方法に関し、詳しくはテレフタル酸等の不純物を含
有する粗イソフタル酸をメタノールにて再結晶させるこ
とによって、高純度イソフタル酸を効率よく製造する方
法に関する。[Industrial Application Field] The present invention relates to a method for producing high-purity isophthalic acid, and more specifically, by recrystallizing crude isophthalic acid containing impurities such as terephthalic acid with methanol, high-purity isophthalic acid can be efficiently produced. Relating to a method of manufacturing.
【０００２】0002
【従来の技術及び発明が解決しようとする課題】イソフ
タル酸はポリエステルなどの原料として広く利用されて
いるが、いずれも高純度であることが要求されている。
従来、イソフタル酸は混合キシレン等を酢酸などの溶媒
中で触媒の存在下、液相酸化して製造されている。しか
し、この方法では得られるイソフタル酸には、主にテレ
フタル酸等の異性体の反応生成物が不純物として含有さ
れており、純度は充分に高くない。そのため、ポリエス
テルなどの原料として利用するためには、精製等により
高純度のイソフタル酸を製造する必要がある。BACKGROUND OF THE INVENTION Isophthalic acid is widely used as a raw material for polyester and the like, but it is required to have high purity. Conventionally, isophthalic acid has been produced by liquid-phase oxidation of mixed xylenes and the like in a solvent such as acetic acid in the presence of a catalyst. However, the isophthalic acid obtained by this method mainly contains reaction products of isomers such as terephthalic acid as impurities, and the purity is not sufficiently high. Therefore, in order to use it as a raw material for polyester and the like, it is necessary to produce highly pure isophthalic acid through purification or the like.
【０００３】この高純度のイソフタル酸を製造する方法
としては、テレフタル酸，安息香酸等を含有する粗イソ
フタル酸を、トルエン，キシレン等の芳香族炭化水素で
抽出処理して安息香酸を分離し、次いでメタノール，エ
タノール，アセトン，酢酸などで抽出処理してイソフタ
ル酸を精製する方法が提案されている（特公昭３８−１
３６９号公報）。しかし、この方法では抽出処理を行う
ため、抽出液中にテレフタル酸がその溶解度分だけ混入
して、高純度のイソフタル酸を得ることはできなかった
。また、溶解度の差を大きくするために、抽出を２０〜
５０℃程度の比較的低い温度で行う結果、溶媒量をイソ
フタル酸１重量部当たり３５〜３５０重量部と多くする
必要があり、装置の大型化が避けられなかった。[0003] As a method for producing this high-purity isophthalic acid, crude isophthalic acid containing terephthalic acid, benzoic acid, etc. is extracted with an aromatic hydrocarbon such as toluene or xylene to separate benzoic acid. Next, a method of purifying isophthalic acid by extraction with methanol, ethanol, acetone, acetic acid, etc. has been proposed (Japanese Patent Publication No. 38-1
Publication No. 369). However, since this method involves an extraction process, terephthalic acid is mixed into the extract by an amount equal to its solubility, making it impossible to obtain highly pure isophthalic acid. In addition, in order to increase the difference in solubility, the extraction was
As a result of carrying out the process at a relatively low temperature of about 50° C., it was necessary to increase the amount of solvent to 35 to 350 parts by weight per 1 part by weight of isophthalic acid, making it inevitable to increase the size of the apparatus.
【０００４】さらに、粗イソフタル酸を酢酸−水の混合
溶媒媒にて、一定の条件下で再結晶させる高純度のイソ
フタル酸の製造方法も提案されている（特公昭５４─３
８５６号公報）。この方法は、三段階の晶析操作を行う
必要があり、分離操作が複雑である。また酢酸−水の混
合溶媒はイソフタル酸の溶解度が低いため、１２０〜２
００℃の高温で再結晶を行うため、機器の腐食の問題が
あった。このように、充分満足できる高純度イソフタル
酸の製造方法は開発されていないのが現状である。Furthermore, a method for producing high-purity isophthalic acid has been proposed in which crude isophthalic acid is recrystallized in a mixed solvent of acetic acid and water under certain conditions (Japanese Patent Publication No. 54-3).
Publication No. 856). This method requires a three-step crystallization operation, and the separation operation is complicated. In addition, since the solubility of isophthalic acid is low in acetic acid-water mixed solvent,
Since recrystallization was carried out at a high temperature of 00°C, there was a problem of equipment corrosion. As described above, at present, a method for producing highly pure isophthalic acid that is fully satisfactory has not been developed.
【０００５】[0005]
【課題を解決するための手段】そこで、本発明者らは上
記の問題点を解決し、より簡便な方法で、テレフタル酸
等の不純物を除去して高純度のイソフタル酸を効率よく
製造する方法を開発すべく鋭意研究を重ねた。その結果
、メタノールを溶媒として再結晶するという簡単な工程
により、目的を達成できることを見出した。本発明はか
かる知見に基いて完成したものである。[Means for Solving the Problems] Therefore, the present inventors solved the above problems and created a method for efficiently producing high-purity isophthalic acid by removing impurities such as terephthalic acid using a simpler method. We conducted extensive research to develop this. As a result, they found that the objective could be achieved by a simple process of recrystallization using methanol as a solvent. The present invention was completed based on this knowledge.
【０００６】すなわち、本発明はテレフタル酸を含有す
る粗イソフタル酸を、メタノールを溶媒として溶解し、
再結晶させることを特徴とする高純度イソフタル酸の製
造方法を提供するものである。That is, the present invention involves dissolving crude isophthalic acid containing terephthalic acid in methanol as a solvent,
The present invention provides a method for producing high-purity isophthalic acid, which is characterized by recrystallization.
【０００７】本発明の方法の原料である粗イソフタル酸
は、種々の公知のイソフタル酸の製造方法により得られ
たものである。通常、異性体の生成物としてテレフタル
酸が不純物として含有されており、物性が類似している
ためにイソフタル酸との分離が困難なものである。他に
、反応原料，安息公酸等の不純物が含有されているもの
であってもよい。ここで、一般的なイソフタル酸の製造
方法の一例を述べる。まず、原料としては、ｍ−キシレ
ンが用いられるが、異性体のｏ−キシレン，ｐ−キシレ
ン等、あるいはエチルベンゼン等を含有するものであっ
てもよい。この原料を通常、酢酸を溶媒として、触媒の
存在下、液相酸化を行う。ここで、触媒としては、臭化
コバルト，臭化マンガン，臭化ナトリウム等が挙げられ
る。液相酸化は種々の方法で行うことができるが、空気
酸化が一般的である。Crude isophthalic acid, which is a raw material for the method of the present invention, is obtained by various known methods for producing isophthalic acid. Usually, terephthalic acid is contained as an impurity as an isomer product, and it is difficult to separate it from isophthalic acid because their physical properties are similar. In addition, it may contain impurities such as reaction raw materials and benzoic acid. Here, an example of a general method for producing isophthalic acid will be described. First, m-xylene is used as a raw material, but it may also contain isomers such as o-xylene, p-xylene, or ethylbenzene. This raw material is usually subjected to liquid phase oxidation in the presence of a catalyst using acetic acid as a solvent. Here, examples of the catalyst include cobalt bromide, manganese bromide, sodium bromide, and the like. Liquid phase oxidation can be performed in a variety of ways, but air oxidation is common.
【０００８】溶媒の使用量は、特に制限はないが、通常
原料に対して２〜２０倍（重量比）である。また、液相
酸化の条件は、原料，触媒等により適宜選定されるが、
通常１２０〜２４０℃で１〜５時間程度反応を行えばよ
い。このようにして製造されたイソフタル酸は、異性体
であるテレフタル酸，未反応原料等の不純物を含有する
ものである。さらに、本発明の原料としては、上記の如
き方法で得られたものを、従来の精製工程をかけて得ら
れた粗イソフタル酸であってもよい。The amount of solvent to be used is not particularly limited, but is usually 2 to 20 times (by weight) the amount of the raw material. In addition, the conditions for liquid phase oxidation are appropriately selected depending on the raw materials, catalyst, etc.
Usually, the reaction may be carried out at 120 to 240°C for about 1 to 5 hours. Isophthalic acid produced in this manner contains impurities such as isomer terephthalic acid and unreacted raw materials. Furthermore, the raw material of the present invention may be crude isophthalic acid obtained by subjecting the above-described method to a conventional purification process.
【０００９】本発明の方法では、このようなテレフタル
酸等の不純物を含有する粗イソフタル酸を、メタノール
を溶媒として溶解し、再結晶を行う。本発明では、溶媒
としてメタノールを使用することが必要である。メタノ
ールは、テレフタル酸の溶解度が他の溶媒より大きく、
簡便な再結晶の操作で高純度イソフタル酸を製造できる
のである。ここで、使用するメタノールの量は、粗イソ
フタル酸の純度等により異なり適宜決定すればよいが、
通常粗イソフタル酸に対して２〜３０倍（重量比）、好
ましくは４〜２０倍（重量比）である。使用量が２倍（
重量比）未満であると、溶解させることが困難で再結晶
が速やかに行えず、また３０倍（重量比）を超えて多く
使用しても特に利点はなく、かえって大型な装置が必要
になり、また収量が低下して好ましくない。In the method of the present invention, crude isophthalic acid containing impurities such as terephthalic acid is dissolved in methanol as a solvent and recrystallized. The invention requires the use of methanol as solvent. Methanol has greater solubility of terephthalic acid than other solvents,
High purity isophthalic acid can be produced by a simple recrystallization procedure. Here, the amount of methanol used varies depending on the purity of the crude isophthalic acid and may be determined as appropriate.
It is usually 2 to 30 times (weight ratio), preferably 4 to 20 times (weight ratio) to crude isophthalic acid. Usage amount is doubled (
If the amount is less than 30 times (weight ratio), it is difficult to dissolve and recrystallization cannot be performed quickly, and there is no particular advantage even if the amount is used in excess of 30 times (weight ratio), and larger equipment is required. , and the yield decreases, which is not preferable.
【００１０】上述の量のメタノールを、粗イソフタル酸
に添加して、溶解した後冷却することにより、再結晶化
を行う。溶解は、通常加熱して行われ、加熱温度は特に
制限なく、大気圧下においてメタノールの沸点６４．６
℃で還流することで有効に行うことができる。この溶解
は、通常大気圧で行われるが、加圧あるいは減圧下で行
ってもよい。加熱時間は、通常１０〜３０分程度である
が、特に制限なく、粗イソフタル酸の量等により適宜選
択すればよい。Recrystallization is carried out by adding the above-mentioned amount of methanol to the crude isophthalic acid, dissolving it, and then cooling it. Dissolution is usually carried out by heating, and the heating temperature is not particularly limited; the boiling point of methanol is 64.6 at atmospheric pressure.
This can be effectively carried out by refluxing at °C. This dissolution is usually carried out at atmospheric pressure, but may also be carried out under increased pressure or reduced pressure. The heating time is usually about 10 to 30 minutes, but is not particularly limited and may be appropriately selected depending on the amount of crude isophthalic acid and the like.
【００１１】再結晶化にあたり、粗イソフタル酸のメタ
ノール溶液の濃縮は、必ずしも要しないが、このメタノ
ール溶液の濃縮を行うと、回収率が向上し好ましい。濃
縮の条件は、通常行われている方法で良く特に制限はな
い。好ましくは、メタノール量の５〜９０％程度を留去
する。この濃縮は、通常は減圧あるいは常圧下、３０〜
６７℃程度の温度で、０．１〜１．０時間程度加熱する
ことにより行う。上記溶液（または濃縮溶液）から、イ
ソフタル酸を再結晶させるにあたっては、該溶液を１０
〜２０℃程度で放冷すればよいが、必要により冷却を行
ってもよい。このようなメタノールでの再結晶の操作に
より生成したイソフタル酸の結晶を、濾過等により分離
する。ここで、得られたイソフタル酸は純度が９９．９
％以上と高いものである。さらに、濾液をさらに濃縮し
て高純度イソフタル酸を回収してもよい。Although it is not necessarily necessary to concentrate the methanol solution of crude isophthalic acid during recrystallization, it is preferable to concentrate the methanol solution because it improves the recovery rate. Concentration conditions are not particularly limited and may be any commonly used method. Preferably, about 5 to 90% of the methanol amount is distilled off. This concentration is usually carried out under reduced pressure or normal pressure for 30 to 30 minutes.
This is carried out by heating at a temperature of about 67° C. for about 0.1 to 1.0 hours. In recrystallizing isophthalic acid from the above solution (or concentrated solution), the solution is
It may be allowed to cool to about 20° C., but cooling may be performed if necessary. Isophthalic acid crystals produced by such recrystallization with methanol are separated by filtration or the like. Here, the purity of the obtained isophthalic acid is 99.9.
% or more. Additionally, the filtrate may be further concentrated to recover high purity isophthalic acid.
【００１２】0012
【実施例】次に本発明を実施例及び比較例により、さら
に詳しく説明する。実施例１
エチルベンゼン０．９４％，オルトキシレン０．８３％
，メタキシレン９５．８８％，パラキシレン１．８５％
及び炭素数９の非芳香族系化合物０．０５％の組成から
なる原料２００ｇを、臭化コバルト１．９ｇ，臭化マン
ガン３．９ｇ及び臭化ナトリウム１．９ｇを触媒として
、１０００Ｌ（Ｌ＝リットル）の酢酸溶媒中、２００℃
にて３時間液相空気酸化を行った。反応終了後、析出固
形物を濾過して、イソフタル酸９８．１％，テレフタル
酸１．９％の粗１ソフタル酸２９１ｇを得た。この粗イ
ソフタル酸１００ｇに、メタノール２２００ｇを加え、
３０分間還流して溶解した後、そのまま加熱濃縮した。
メタノール１９００ｇを留去した後、加熱を停止して２
０℃まで放冷した。
濾過して、固形物８８．３ｇを得た。この固形物中のイ
ソフタル酸の純度は９９．９％であった。EXAMPLES Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples. Example 1 Ethylbenzene 0.94%, ortho-xylene 0.83%
, meta-xylene 95.88%, para-xylene 1.85%
and 0.05% non-aromatic compound having 9 carbon atoms, 1000 L (L= l) in acetic acid solvent at 200°C.
Liquid phase air oxidation was performed for 3 hours at . After the reaction was completed, the precipitated solid was filtered to obtain 291 g of crude 1-sophthalic acid containing 98.1% isophthalic acid and 1.9% terephthalic acid. Add 2200 g of methanol to 100 g of this crude isophthalic acid,
After refluxing for 30 minutes to dissolve, the mixture was directly concentrated by heating. After distilling off 1900g of methanol, heating was stopped and 2
It was left to cool to 0°C. Filtration yielded 88.3 g of solid. The purity of isophthalic acid in this solid was 99.9%.
【００１３】実施例２
イソフタル酸９５．０％及びテレフタル酸５．０％から
なる酸化反応生成固形物１００ｇを、メタノール２１０
０ｇに加え、大気圧下に６４．７℃で加熱融解後、放冷
して２０℃とした。析出した固形物を濾別し、純度９９
．９％のイソフタル酸８９．１ｇを得た。Example 2 100 g of a solid product produced by an oxidation reaction consisting of 95.0% isophthalic acid and 5.0% terephthalic acid was mixed with 210 g of methanol.
After heating and melting at 64.7°C under atmospheric pressure, the mixture was allowed to cool to 20°C. The precipitated solid was filtered and the purity was 99.
．． 89.1 g of 9% isophthalic acid was obtained.
【００１４】比較例１
イソフタル酸９５．０％及びテレフタル酸５．０％から
なる酸化反応生成固形物１００ｇを、酢酸−水の混合溶
媒（重量比９５：５）９００ｇに加え、２０ｋｇ／ｃｍ
２Ｇの圧力下に２００℃で加熱融解後、放冷して２０℃
とした。
析出した固形物を濾別し、純度９５．２％のイソフタル
酸９０．０ｇを得た。Comparative Example 1 100 g of a solid produced by an oxidation reaction consisting of 95.0% isophthalic acid and 5.0% terephthalic acid was added to 900 g of a mixed solvent of acetic acid and water (weight ratio 95:5), and the mixture was heated at 20 kg/cm.
After heating and melting at 200℃ under 2G pressure, let it cool to 20℃
And so. The precipitated solid was filtered off to obtain 90.0 g of isophthalic acid with a purity of 95.2%.
【００１５】実施例３
純度９５％，９６％，９７％及び９８％のイソフタル酸
を原料として、大気圧下，６４．７℃から２０℃まで冷
却再結晶した際、使用したメタノール量を種々に変えて
、得られる高純度イソフタル酸との関係を検討した。な
お、再結晶はメタノールを濃縮せずに行った。結果を図
１に示す。また、９９．９％の高純度イソフタル酸を得
るために必要なメタノール量と原料の純度の関係を検討
した。結果を図２に示す。Example 3 Isophthalic acid with a purity of 95%, 96%, 97% and 98% was used as a raw material and recrystallized by cooling from 64.7°C to 20°C under atmospheric pressure.The amount of methanol used was varied. The relationship with the obtained high-purity isophthalic acid was investigated. Note that recrystallization was performed without concentrating methanol. The results are shown in Figure 1. In addition, the relationship between the amount of methanol required to obtain 99.9% high-purity isophthalic acid and the purity of the raw material was investigated. The results are shown in Figure 2.
【００１６】[0016]
【発明の効果】以上のように、本発明の製造方法によれ
ば従来分離が困難であった粗イソフタル酸中のテレフタ
ル酸等の不純物を再結晶という簡易な操作で、効率良く
精製でき、高純度のイソフタル酸を製造することができ
る。また、使用する溶媒であるメタノール量も比較的少
なくてよく大型装置の必要もない。このように、本発明
の製造方法で得られた高純度のイソフタル酸は、種々の
用途に幅広く有効に利用できる。As described above, according to the production method of the present invention, impurities such as terephthalic acid in crude isophthalic acid, which had been difficult to separate, can be efficiently purified by a simple operation of recrystallization, and a high Purity of isophthalic acid can be produced. Further, the amount of methanol used as a solvent may be relatively small, and there is no need for large-scale equipment. As described above, the highly purified isophthalic acid obtained by the production method of the present invention can be effectively used in a wide variety of applications.
【図１】図１は、原料の粗イソフタル酸（粗ＩＰＡ）の
各純度におけるメタノール（ＭｅＯＨ）の使用量（粗Ｉ
ＰＡに対する重量倍）（横軸）と製造される高純度イソ
フタル酸（精製ＩＰＡ）の純度（縦軸）との関係を示す
グラフ（但し、メタノールを濃縮しない場合の関係を示
すグラフ）である。[Figure 1] Figure 1 shows the amount of methanol (MeOH) used (crude IPA) for each purity of raw material crude isophthalic acid (crude IPA).
This is a graph showing the relationship between the weight times the weight of PA (horizontal axis) and the purity (vertical axis) of high-purity isophthalic acid (purified IPA) produced (however, this graph shows the relationship when methanol is not concentrated).
【図２】図２は、原料の粗イソフタル酸（粗ＩＰＡ）の
純度（横軸）に対する９９．９％の高純度イソフタル酸
（精製ＩＰＡ）を製造するために必要なメタノール（Ｍ
ｅＯＨ）の使用量（縦軸）の関係を示すグラフ（但し、
メタノールを濃縮しない場合の関係を示すグラフ）であ
る。[Figure 2] Figure 2 shows the methanol (M
A graph showing the relationship between the amount of eOH) used (vertical axis) (however,
Fig. 2 is a graph showing the relationship when methanol is not concentrated.
Claims (2)
酸を、メタノールを溶媒として溶解し、再結晶させるこ
とを特徴とする高純度イソフタル酸の製造方法。1. A method for producing high-purity isophthalic acid, which comprises dissolving crude isophthalic acid containing terephthalic acid in methanol as a solvent and recrystallizing it.
て、濃縮した後に再結晶する請求項１の製造方法。2. The production method according to claim 1, wherein crude isophthalic acid is dissolved in methanol, concentrated, and then recrystallized.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP41183890A JPH04221340A (en) | 1990-12-20 | 1990-12-20 | Production of highly pure isophthalic acid |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP41183890A JPH04221340A (en) | 1990-12-20 | 1990-12-20 | Production of highly pure isophthalic acid |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH04221340A true JPH04221340A (en) | 1992-08-11 |
Family
ID=18520771
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP41183890A Pending JPH04221340A (en) | 1990-12-20 | 1990-12-20 | Production of highly pure isophthalic acid |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH04221340A (en) |
-
1990
- 1990-12-20 JP JP41183890A patent/JPH04221340A/en active Pending
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