JPH0445504B2 - - Google Patents
Info
- Publication number
- JPH0445504B2 JPH0445504B2 JP60252633A JP25263385A JPH0445504B2 JP H0445504 B2 JPH0445504 B2 JP H0445504B2 JP 60252633 A JP60252633 A JP 60252633A JP 25263385 A JP25263385 A JP 25263385A JP H0445504 B2 JPH0445504 B2 JP H0445504B2
- Authority
- JP
- Japan
- Prior art keywords
- methanol
- boiling
- dimethyl terephthalate
- product
- methyl
- 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 - Lifetime
Links
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 claims description 99
- WOZVHXUHUFLZGK-UHFFFAOYSA-N dimethyl terephthalate Chemical compound COC(=O)C1=CC=C(C(=O)OC)C=C1 WOZVHXUHUFLZGK-UHFFFAOYSA-N 0.000 claims description 50
- 238000009835 boiling Methods 0.000 claims description 26
- 239000006227 byproduct Substances 0.000 claims description 23
- 238000000034 method Methods 0.000 claims description 19
- 239000004480 active ingredient Substances 0.000 claims description 16
- 239000003054 catalyst Substances 0.000 claims description 9
- QSSJZLPUHJDYKF-UHFFFAOYSA-N methyl 4-methylbenzoate Chemical compound COC(=O)C1=CC=C(C)C=C1 QSSJZLPUHJDYKF-UHFFFAOYSA-N 0.000 claims description 9
- URLKBWYHVLBVBO-UHFFFAOYSA-N Para-Xylene Chemical group CC1=CC=C(C)C=C1 URLKBWYHVLBVBO-UHFFFAOYSA-N 0.000 claims description 7
- 230000003647 oxidation Effects 0.000 claims description 7
- 238000007254 oxidation reaction Methods 0.000 claims description 7
- 229910001385 heavy metal Inorganic materials 0.000 claims description 5
- 239000007791 liquid phase Substances 0.000 claims description 4
- 230000001590 oxidative effect Effects 0.000 claims description 3
- 238000011084 recovery Methods 0.000 claims description 3
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 claims description 2
- 229910001882 dioxygen Inorganic materials 0.000 claims description 2
- 230000000694 effects Effects 0.000 claims description 2
- 239000007789 gas Substances 0.000 claims description 2
- 238000006243 chemical reaction Methods 0.000 description 16
- 238000004821 distillation Methods 0.000 description 14
- 238000004519 manufacturing process Methods 0.000 description 6
- VBWFYEFYHJRJER-UHFFFAOYSA-N methyl 4-(hydroxymethyl)benzoate Chemical compound COC(=O)C1=CC=C(CO)C=C1 VBWFYEFYHJRJER-UHFFFAOYSA-N 0.000 description 5
- FEIOASZZURHTHB-UHFFFAOYSA-N methyl 4-formylbenzoate Chemical compound COC(=O)C1=CC=C(C=O)C=C1 FEIOASZZURHTHB-UHFFFAOYSA-N 0.000 description 4
- 239000000047 product Substances 0.000 description 4
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 3
- 229910017052 cobalt Inorganic materials 0.000 description 3
- 239000010941 cobalt Substances 0.000 description 3
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 3
- 229910052748 manganese Inorganic materials 0.000 description 3
- 239000011572 manganese Substances 0.000 description 3
- LPNBBFKOUUSUDB-UHFFFAOYSA-N p-toluic acid Chemical compound CC1=CC=C(C(O)=O)C=C1 LPNBBFKOUUSUDB-UHFFFAOYSA-N 0.000 description 3
- KMTDMTZBNYGUNX-UHFFFAOYSA-N 4-methylbenzyl alcohol Chemical compound CC1=CC=C(CO)C=C1 KMTDMTZBNYGUNX-UHFFFAOYSA-N 0.000 description 2
- LCGLNKUTAGEVQW-UHFFFAOYSA-N Dimethyl ether Chemical compound COC LCGLNKUTAGEVQW-UHFFFAOYSA-N 0.000 description 2
- 239000007795 chemical reaction product Substances 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 description 2
- 239000012452 mother liquor Substances 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N nitrogen Substances N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 230000035484 reaction time Effects 0.000 description 2
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000012141 concentrate Substances 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000032050 esterification Effects 0.000 description 1
- 238000005886 esterification reaction Methods 0.000 description 1
- 238000007701 flash-distillation Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- WVWZECQNFWFVFW-UHFFFAOYSA-N methyl 2-methylbenzoate Chemical compound COC(=O)C1=CC=CC=C1C WVWZECQNFWFVFW-UHFFFAOYSA-N 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- QJGQUHMNIGDVPM-UHFFFAOYSA-N nitrogen group Chemical group [N] QJGQUHMNIGDVPM-UHFFFAOYSA-N 0.000 description 1
- 239000011541 reaction mixture Substances 0.000 description 1
- 238000001953 recrystallisation Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 238000007086 side reaction Methods 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- KKEYFWRCBNTPAC-UHFFFAOYSA-L terephthalate(2-) Chemical compound [O-]C(=O)C1=CC=C(C([O-])=O)C=C1 KKEYFWRCBNTPAC-UHFFFAOYSA-L 0.000 description 1
- 239000010936 titanium Substances 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- 238000005809 transesterification reaction Methods 0.000 description 1
- 238000005292 vacuum distillation Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 238000003809 water extraction Methods 0.000 description 1
Landscapes
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Description
【発明の詳細な説明】
(a) 産業上の利用分野
本発明は、特許第235515号（特公昭32−2765号
公報）、特許第286284号（特公昭36−7022号公報）
に記載された如き、Ｐ−キシレンおよび／または
Ｐ−トルイル酸メチルを酸化し、ついでメチルエ
ステル化することによつてテレフタル酸ジメチル
を製造する工程において生成する高沸点副生成物
からテレフタル酸ジメチル、Ｐ−トルイル酸メチ
ルおよびＰ−ハイドロオキシメチル安息香酸メチ
ルの如き有効成分を回収する方法に関するもので
ある。
(b) 従来技術
従来、メタノールとの反応により、前記高沸点
副生成物からテレフタル酸ジメチル製造工程に循
環使用可能なテレフタル酸ジメチル、Ｐ−トルイ
ル酸メチルおよびＰ−ハイドロオキシメチル安息
香酸メチルの如き有効成分を回収し得ることは公
知である。
しかしながら特公昭56−20303号公報、特開昭
49−66644号公報および特公昭53−30699号公報記
載のように、前記高沸点副生成物を高温でメタノ
ールと接触させ、有効成分を回収する方法におい
ては反応速度の面から反応温度を250℃以上の高
温とする必要がある。このため好ましからざる副
反応が起り、有効成分、特にＰ−ハイドロオキシ
メチル安息香酸メチルの回収率が低下するのみな
らずジメチルエーテルの生成によるメタノールの
損失、用役費の増大といつた欠点を有している。
また、前述の方法においては高沸点副生成物中
のテレフタル酸ジメチル、Ｐ−トルイル−Ｐ−ト
ルエート濃度を下げる必要があり、そのため後蒸
留を実施しているがこれは設備費等の増加につな
がり、工業的に有利な方法とは言えない。
(c) 発明の目的
そこで本発明者らは、高沸点副生成物から有効
成分を回収する方法において従来技術より更に高
収率で、しかも工業的に有利な方法で回収しうる
方法について鋭意研究を進めたところ、本発明に
到達した。
(d) 発明の構成および効果
すなわち、本発明はＰ−キシレンおよび／また
はＰ−トルイル酸メチルを重金属酸化触媒の存在
下、分子状酸素含有ガスにより酸化し、ついでメ
タノールでエステル化することによつてテレフタ
ル酸ジメチルを製造する際に副生するテレフタル
酸ジメチルよりも沸点が高い高沸点副生成物を
110〜240℃の範囲の温度でメタノールを液相に保
持するに充分な圧力下、メタノールと反応させる
ことを特徴とする前記高沸点副生成物からの有効
成分回収法である。
かかる本発明の方法によれば前記高沸点副生成
物を液状のメタノールと接触させることにより従
来技術に比べ比較的低温かつ短時間で、しかも高
収率で高沸点副生成物から有効成分を回収するこ
とが可能となる。
以下、本発明について更に詳細に説明する。
本発明の方法に用いる“テレフタル酸ジメチル
よりも沸点の高い高沸点副生成物”とはＰ−キシ
レンおよび／またはＰ−トルイル酸メチルを酸化
し、ついでエステル化することによつてテレフタ
ル酸ジメチルを製造する際、テレフタル酸ジメチ
ルを蒸留等によつて分離、精製した後に残存する
残渣または該残渣より再結晶、蒸留等の方法によ
り、テレフタル酸ジメチルを殆んど回収した後の
高沸点副生成物の濃縮物をいう。
すなわち、本発明の方法に用いる高沸点副生成
物は、テレフタル酸ジメチルやＰ−トルイル−ｐ
−トルエートの含有量に関して何ら制約を受けな
い。従つて、特公昭56−20303号公報、特開昭49
−66644号公報、特公昭53−30699号公報に記載の
如き後蒸留を全く必要とせず、粗テレフタル酸ジ
メチル製造工程から得られる蒸留残渣をそのまま
使用することができ、工業的に大変有利である。
本発明において、前記高沸点副生成物とメタノ
ールを反応させる場合、特に触媒を添加する必要
はなく、Ｐ−キシレンからテレフタル酸ジメチル
を製造する際に使用した重金属酸化触媒が残存し
ている高沸点副生成物であつても、あるいは該金
属を抽出除去した後の抽残物であつても、いずれ
も本発明を実施しうるが、重金属酸化触媒が残存
している方が反応の進行が速いため有効に実施で
きる。
また、公知のエステル化触媒やエステル交換触
媒の存在下で実施することもできる。
本発明に用いるメタノールとしては精製メタノ
ールだけでなく、粗テレフタル酸ジメチルをメタ
ノールで再結晶精製した後の母液もそのまま使用
できる。
メタノールの使用量は高沸点副生成物に対し重
量比で１／10〜10倍の範囲、好ましくは１／４〜
４倍の範囲が望ましい。メタノールの使用量が
１／10倍より少ない場合は有効成分回収量が大幅
に低下するため好ましくない。また、メタノール
使用量を10倍より多くしても多くすることによつ
て有効成分回収量は、殆んど増加しないので工業
的に有利でない。
本発明における高沸点副生成物とメタノールと
の反応はメタノールの臨界温度以下の温度で即ち
110〜240℃の範囲で、好ましくは135〜235℃の範
囲で、かつメタノールを液相に保持するのに充分
な圧力下で実施することができる。
本発明における高沸点副生成物とメタノールと
の反応時間は反応温度等の諸条件に左右され一定
でないが、一般に0.1〜10時間が好ましい。
本発明の方法は回分式または連続式のいずれの
方法によつても実施することができる。
本発明におけるメタノール処理生成物からの有
効成分の分離は、まずフラツシユ蒸留によりメタ
ノールを留去したのち通常の減圧蒸留を行うこと
により可能であり、従来技術の如く、水蒸気蒸留
やキヤリアを添加しながらの蒸留のような特殊な
蒸留操作を必要としないため、設備費、用役費等
の大幅なコスト低減が可能であり、工業的に極め
て有利である。また、メタノール処理生成物から
公知の方法により、まずテレフタル酸ジメチルを
再結晶分離した後、公知の方法で母液を蒸留する
ことにより、他の有効成分を分離回収することも
できる。
このようにして得られた有効成分は、テレフタ
ル酸ジメチル製造工程に循環することが可能であ
り、全体として本発明によりテレフタル酸ジメチ
ルの収率を大巾に改善できる。
以下実施例を掲げ本発明方法を詳述する。
実施例 １
ｐ−キシレンとｐ−トルイル酸メチルとの混合
物をコバルトおよびマンガン触媒の存在下、所定
の温度、圧力下で空気により連続的に液相酸化
し、得られたＰ−トルイル酸およびテレフタル酸
モノメチルを主成分とする酸化生成物をメタノー
ルでエステル化し、ついで得られたエステル化生
成物を減圧蒸留して粗テレフタル酸ジメチル、Ｐ
−トルイル酸メチルを主成分とする留分および蒸
留残渣に分けるテレフタル酸ジメチル製造工程か
ら、高沸点副生成物の他にテレフタル酸ジメチル
を15wt％含む前記蒸留残渣を得た。また、該蒸
留残渣中にはＰ−トルイル−Ｐ−トルエートが
0.9wt％含まれていた。
該蒸留残渣100ｇとメタノール100ｇとを撹拌機
を備えた容量500mlのチタン製オートクレーブに
仕込みオートクレーブ内を窒素置換した後、温度
230℃、反応圧力49Kg／cm2Ｇで撹拌下、１時間保
持した。
反応終了後反応生成物を取り出し、湯浴上でメ
タノールを留去した後、20mmHgで減圧蒸留を行
い、テレフタル酸ジメチル32.6ｇ、Ｐ−トルイル
酸メチル4.5ｇ、Ｐ−ハイドロオキシメチル安息
香酸メチル11.6ｇ、Ｐ−トルイルアルコール2.2
ｇ、Ｐ−ホルミル安息香酸メチル0.6ｇおよびＰ
−トルアルデヒド0.1ｇを得た。
実施例２〜５、比較例１
実施例１と同様の方法でメタノール量、反応温
度、反応時間を変えて反応を行つた後、実施例１
と同じ操作により有効成分を回収した。反応条件
および反応結果を下記表に示す。
実施例 ６
実施例１で用いた蒸留残渣から95℃で水抽出を
行うことによりコバルトおよびマンガンを除去
し、各々18ppmと1ppmとした。110℃で乾燥後こ
のコバルト、マンガン含量の少ない蒸留残渣を用
いて、実施例１と同じ反応および有効成分回収操
作を行つた。反応結果を下記表に示す。
比較例 ２
実施例１で用いた蒸留残渣150ｇを実施例１と
同じオートクレーブに仕込み、290℃、28Kg／cm2
Ｇでメタノールを150ｇ／hr、窒素ガスを60／
hrの速度で４時間連続的にフイードした。メタノ
ール蒸気は連続的に取出しかつ放圧して大気圧に
した後、冷却器にて凝縮させた。
反応終了後、オートクレーブ中の反応生成物と
凝縮メタノールをあわせた後、実施例１と同じ操
作を行い、テレフタル酸ジメチル46.1ｇＰ−トル
イル酸メチル7.0ｇ、Ｐ−ハイドロオキシメチル
安息香酸メチル6.5ｇ、Ｐ−トルイルアルコール
1.1ｇおよびＰ−ホルミル安息香酸メチル0.8ｇを
得た。
【表】[Detailed description of the invention] (a) Industrial field of application The present invention is applicable to patent No. 235515 (Japanese Patent Publication No. 32-2765) and patent No. 286284 (Japanese Patent Publication No. 7022-1989)
dimethyl terephthalate from the high-boiling byproduct produced in the process of producing dimethyl terephthalate by oxidizing P-xylene and/or methyl P-toluate and then methyl esterifying it, as described in . The present invention relates to a method for recovering active ingredients such as methyl P-toluate and methyl P-hydroxymethylbenzoate. (b) Prior Art Conventionally, dimethyl terephthalate, methyl P-toluate, and methyl P-hydroxymethylbenzoate, which can be recycled to the dimethyl terephthalate production process from the high-boiling byproducts by reaction with methanol, have been produced. It is known that active ingredients can be recovered. However, Japanese Patent Publication No. 56-20303,
As described in Japanese Patent Publication No. 49-66644 and Japanese Patent Publication No. 53-30699, in the method of recovering the active ingredient by contacting the high boiling point by-product with methanol at high temperature, the reaction temperature is set at 250°C from the viewpoint of reaction rate. The temperature must be higher than that. As a result, undesirable side reactions occur, which not only reduces the recovery rate of the active ingredient, especially methyl P-hydroxymethylbenzoate, but also causes the loss of methanol due to the formation of dimethyl ether and increases utility costs. ing. In addition, in the above-mentioned method, it is necessary to reduce the concentration of dimethyl terephthalate and P-toluyl-P-toluate in the high-boiling byproducts, and therefore post-distillation is performed, but this leads to an increase in equipment costs, etc. , cannot be said to be an industrially advantageous method. (c) Purpose of the Invention Therefore, the present inventors have conducted intensive research into a method for recovering active ingredients from high-boiling byproducts with a higher yield than conventional techniques and in an industrially advantageous manner. As a result, we have arrived at the present invention. (d) Structure and effects of the invention That is, the present invention oxidizes P-xylene and/or methyl P-toluate with a molecular oxygen-containing gas in the presence of a heavy metal oxidation catalyst, and then esterifies it with methanol. When manufacturing dimethyl terephthalate, a high-boiling by-product with a boiling point higher than that of dimethyl terephthalate is produced.
A method for recovering active ingredients from the above-mentioned high-boiling byproducts, characterized in that the reaction is carried out with methanol at a temperature in the range of 110 to 240° C. and under sufficient pressure to maintain the methanol in the liquid phase. According to the method of the present invention, by bringing the high-boiling by-product into contact with liquid methanol, the active ingredient can be recovered from the high-boiling by-product at a relatively low temperature and in a short time, and in a high yield, compared to conventional techniques. It becomes possible to do so. The present invention will be explained in more detail below. The "high-boiling byproduct with a boiling point higher than that of dimethyl terephthalate" used in the method of the present invention refers to dimethyl terephthalate produced by oxidizing P-xylene and/or methyl P-toluate and then esterifying it. During production, the residue remaining after dimethyl terephthalate is separated and purified by distillation, etc., or the high-boiling byproduct after most of dimethyl terephthalate is recovered from the residue by methods such as recrystallization and distillation. A concentrate of That is, the high-boiling byproducts used in the method of the present invention include dimethyl terephthalate and p-toluyl-p.
- There are no restrictions regarding the content of toluate. Therefore, Japanese Patent Publication No. 56-20303, Japanese Patent Publication No. 49/1973
There is no need for post-distillation as described in Japanese Patent Publication No. 66644 and Japanese Patent Publication No. 53-30699, and the distillation residue obtained from the crude dimethyl terephthalate manufacturing process can be used as it is, which is very advantageous industrially. . In the present invention, when the high-boiling by-product is reacted with methanol, there is no need to add any particular catalyst, and the heavy metal oxidation catalyst used in producing dimethyl terephthalate from P-xylene remains at a high boiling point. The present invention can be carried out using either a by-product or a raffinate after extracting and removing the metal, but the reaction proceeds faster if the heavy metal oxidation catalyst remains. Therefore, it can be implemented effectively. Moreover, it can also be carried out in the presence of a known esterification catalyst or transesterification catalyst. As the methanol used in the present invention, not only purified methanol but also a mother liquor obtained by recrystallizing and purifying crude dimethyl terephthalate with methanol can be used as it is. The amount of methanol used is in the range of 1/10 to 10 times, preferably 1/4 to 10 times the weight of the high-boiling byproduct.
A range of 4 times is desirable. If the amount of methanol used is less than 1/10 times, it is not preferable because the amount of active ingredient recovered will be significantly reduced. Further, even if the amount of methanol used is increased by more than 10 times, the amount of active ingredient recovered hardly increases, which is not industrially advantageous. In the present invention, the reaction between the high-boiling byproduct and methanol is carried out at a temperature below the critical temperature of methanol.
It can be carried out in the range 110-240°C, preferably in the range 135-235°C, and under sufficient pressure to maintain the methanol in the liquid phase. The reaction time of the high-boiling by-product and methanol in the present invention varies depending on various conditions such as reaction temperature, but is generally preferably 0.1 to 10 hours. The method of the present invention can be carried out either batchwise or continuously. The separation of the active ingredients from the methanol-treated product in the present invention is possible by first distilling methanol off by flash distillation and then carrying out ordinary vacuum distillation. Since it does not require special distillation operations such as the distillation of Further, other active ingredients can also be separated and recovered by first recrystallizing dimethyl terephthalate from the methanol-treated product by a known method and then distilling the mother liquor by a known method. The active ingredient thus obtained can be recycled to the dimethyl terephthalate production process, and overall the present invention can greatly improve the yield of dimethyl terephthalate. The method of the present invention will be described in detail below with reference to Examples. Example 1 A mixture of p-xylene and methyl p-toluate was subjected to continuous liquid phase oxidation with air at a predetermined temperature and pressure in the presence of cobalt and manganese catalysts, and the resulting p-toluic acid and terephthalate were The oxidation product containing monomethyl acid as a main component is esterified with methanol, and the resulting esterified product is then distilled under reduced pressure to obtain crude dimethyl terephthalate, P
The distillation residue containing 15 wt % of dimethyl terephthalate in addition to high-boiling by-products was obtained from the dimethyl terephthalate manufacturing process, which is divided into a fraction containing methyl toluate as a main component and a distillation residue. In addition, P-toluyl-P-toluate is contained in the distillation residue.
It contained 0.9wt%. 100 g of the distillation residue and 100 g of methanol were charged into a 500 ml titanium autoclave equipped with a stirrer, and the inside of the autoclave was replaced with nitrogen.
The reaction mixture was maintained at 230° C. and a reaction pressure of 49 Kg/cm 2 G for 1 hour with stirring. After the reaction was completed, the reaction product was taken out, methanol was distilled off on a water bath, and then distilled under reduced pressure at 20 mmHg to obtain 32.6 g of dimethyl terephthalate, 4.5 g of methyl P-toluate, and 11.6 g of methyl P-hydroxymethylbenzoate. g, P-tolyl alcohol 2.2
g, methyl P-formylbenzoate 0.6 g and P
-0.1 g of tolualdehyde was obtained. Examples 2 to 5, Comparative Example 1 After carrying out the reaction in the same manner as in Example 1 by changing the amount of methanol, reaction temperature, and reaction time, Example 1
The active ingredient was recovered by the same procedure. The reaction conditions and reaction results are shown in the table below. Example 6 Cobalt and manganese were removed from the distillation residue used in Example 1 by water extraction at 95° C. to 18 ppm and 1 ppm, respectively. After drying at 110°C, the same reaction and active ingredient recovery operations as in Example 1 were carried out using this distillation residue with low cobalt and manganese contents. The reaction results are shown in the table below. Comparative Example 2 150g of the distillation residue used in Example 1 was placed in the same autoclave as in Example 1, and heated at 290°C and 28Kg/ cm2.
G: 150g/hr of methanol, 60g/hr of nitrogen gas
It was fed continuously for 4 hours at a rate of hr. Methanol vapor was continuously taken out and depressurized to atmospheric pressure, and then condensed in a cooler. After the reaction was completed, the reaction product in the autoclave and condensed methanol were combined, and the same operation as in Example 1 was performed to obtain 46.1 g of dimethyl terephthalate, 7.0 g of methyl P-toluate, 6.5 g of methyl P-hydroxymethylbenzoate, P-toluyl alcohol
1.1 g and 0.8 g of methyl P-formylbenzoate were obtained. 【table】
Claims (1)
メチルを重金属酸化触媒の存在下、分子状酸素含
有ガスにより酸化し、ついでメタノールでエステ
ル化することによつてテレフタル酸ジメチルを製
造する際に副生するテレフタル酸ジメチルよりも
沸点が高い高沸点副生成物を110〜240℃の範囲の
温度でメタノールを液相に保持するに充分な圧力
下、メタノールと反応させることを特徴とする前
記高沸点副生成物からの有効成分回収法。 ２ 該高沸点副生成物を該高沸点副生成物に対
し、重量比で１／10〜10倍量のメタノール存在下
で、反応させることを特徴とする特許請求の範囲
第１項記載の有効成分回収法。 ３ 該高沸点副生成物を、該重金属酸化触媒存在
下でメタノールと反応させることを特徴とする特
許請求の範囲第１項あるいは第２項記載の有効成
分回収法。[Claims] 1. Dimethyl terephthalate is produced by oxidizing P-xylene and/or methyl P-toluate with a molecular oxygen-containing gas in the presence of a heavy metal oxidation catalyst, and then esterifying it with methanol. A high-boiling by-product, which has a boiling point higher than that of dimethyl terephthalate, is reacted with methanol at a temperature in the range of 110 to 240°C under sufficient pressure to maintain the methanol in the liquid phase. A method for recovering active ingredients from the high-boiling by-products. 2. The effect according to claim 1, characterized in that the high-boiling by-product is reacted in the presence of methanol in an amount of 1/10 to 10 times the weight of the high-boiling by-product. Component recovery method. 3. The method for recovering active ingredients according to claim 1 or 2, characterized in that the high-boiling byproduct is reacted with methanol in the presence of the heavy metal oxidation catalyst.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP25263385A JPS62114934A (en) | 1985-11-13 | 1985-11-13 | Recovery of active ingredient |
| US06/928,300 US4760165A (en) | 1985-11-13 | 1986-11-10 | Recovering useful components at least containing dimethyl terephthalate from high-boiling byproducts occurring in the production of dimethyl terephthalate |
| DE8686308812T DE3674161D1 (en) | 1985-11-13 | 1986-11-12 | METHOD FOR OBTAINING USEFUL COMPOUNDS CONTAINING AT LEAST DIMETHYLTEREPHTHALATE FROM THE HIGHLY SEEDING BY-PRODUCTS OF THE PRODUCTION OF DIMETHYLTEREPHTHALATE. |
| EP86308812A EP0225738B1 (en) | 1985-11-13 | 1986-11-12 | Method of recovering useful components at least containing dimethyl terephthalate from high-boiling byproducts occurring in the production of dimethyl terephthalate |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP25263385A JPS62114934A (en) | 1985-11-13 | 1985-11-13 | Recovery of active ingredient |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62114934A JPS62114934A (en) | 1987-05-26 |
| JPH0445504B2 true JPH0445504B2 (en) | 1992-07-27 |
Family
ID=17240067
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP25263385A Granted JPS62114934A (en) | 1985-11-13 | 1985-11-13 | Recovery of active ingredient |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS62114934A (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5312833A (en) * | 1976-07-22 | 1978-02-04 | Mitsubishi Chem Ind Ltd | Preparation of dimethylterephthalate |
-
1985
- 1985-11-13 JP JP25263385A patent/JPS62114934A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5312833A (en) * | 1976-07-22 | 1978-02-04 | Mitsubishi Chem Ind Ltd | Preparation of dimethylterephthalate |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS62114934A (en) | 1987-05-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP3232678B2 (en) | Acetic acid recovery method | |
| EP0031205A2 (en) | Carbonylation of ethylene or propylene | |
| US5292917A (en) | Process for purifying dimethyl carbonate | |
| CA1150303A (en) | Preparation of acids and esters | |
| EP0225738B1 (en) | Method of recovering useful components at least containing dimethyl terephthalate from high-boiling byproducts occurring in the production of dimethyl terephthalate | |
| JPS58183641A (en) | Purification of methyl (meth)acrylate | |
| EP0501374A1 (en) | Process for purifying dimethyl carbonate | |
| JPH0445504B2 (en) | ||
| JPH05271143A (en) | Production of cyclohexanone | |
| JP3986756B2 (en) | Continuous process for producing carboxylic acid esters of alkylene glycol monoalkyl ethers | |
| WO2003057660A1 (en) | Method of decomposing by-product of (meth)acrylic ester production | |
| KR960006664B1 (en) | Process for the extractive separation of a carboxylic acid from an aqueous solution of the said acid | |
| JPS6123781B2 (en) | ||
| JPH03181440A (en) | Purification of acrylic acid by distillation | |
| JPH03133972A (en) | Recovery of water-insoluble epoxyalcohol | |
| JPH0769991A (en) | Production of dimethyl 2,6-naphthalenedicarboxylate | |
| US4529550A (en) | Hydrolysis of anhydride in the production of C5 -C9 saturated aliphatic monocarboxylic acids | |
| JPS62195348A (en) | Method for recovering active ingredient | |
| JPS6056698B2 (en) | Recovery method for dimethyl terephthalate and its intermediates | |
| US4281178A (en) | Process for the production of benzoic acid from process residues that contain benzyl benzoate | |
| JP2533980B2 (en) | Method for producing perpropionic acid | |
| JPS6214534B2 (en) | ||
| US2405471A (en) | Manufacture of acetic anhydride | |
| JP3150909B2 (en) | Purification method of glyoxylates | |
| CN114195692A (en) | 3- (2-hydroxy-2-propyl) cumene hydroperoxide and preparation method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |