JPH06211735A - Method for preventing polymerization of @(3754/24)meth)acrylic acid - Google Patents
Method for preventing polymerization of @(3754/24)meth)acrylic acidInfo
- Publication number
- JPH06211735A JPH06211735A JP863093A JP863093A JPH06211735A JP H06211735 A JPH06211735 A JP H06211735A JP 863093 A JP863093 A JP 863093A JP 863093 A JP863093 A JP 863093A JP H06211735 A JPH06211735 A JP H06211735A
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- JP
- Japan
- Prior art keywords
- acrylic acid
- meth
- polymerization
- acid
- manganese
- 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.)
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- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】この発明は、（メタ）アクリル酸
（この明細書中では、アクリル酸とメタクリル酸に共通
な事柄を述べる場合に、これらの酸を「（メタ）アクリ
ル酸」と総称する。）の重合防止方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to (meth) acrylic acid (in this specification, when mentioning matters common to acrylic acid and methacrylic acid, these acids are collectively referred to as "(meth) acrylic acid"). ).
【０００２】[0002]
【従来の技術】ビニル化合物は、光や熱等により重合し
やすい性質を有する。ビニル化合物の中でも、特に（メ
タ）アクリル酸は、非常に重合しやすい。そのため、従
来、（メタ）アクリル酸の重合を防止するために、（メ
タ）アクリル酸の置かれる条件に応じて、種々の重合防
止剤が単独で、あるいは、複数種組み合わせて用いられ
ている。2. Description of the Related Art Vinyl compounds have the property of being easily polymerized by light or heat. Among the vinyl compounds, (meth) acrylic acid is particularly easy to polymerize. Therefore, conventionally, in order to prevent the polymerization of (meth) acrylic acid, various polymerization inhibitors are used alone or in combination of two or more, depending on the conditions under which (meth) acrylic acid is placed.
【０００３】従来、（メタ）アクリル酸を製造する方法
としては、たとえば、プロピレンおよび／またはアクロ
レインの接触気相酸化反応によりアクリル酸を製造する
方法、イソブチレンおよび／またはメタクロレインの接
触気相酸化反応によりメタクリル酸を製造する方法、等
がよく用いられている。これらの方法では、接触気相酸
化反応で得られた反応生成ガスを冷却し水で捕集して、
酢酸およびアルデヒド等の副生成物を含む（メタ）アク
リル酸の水溶液を得た後、この水溶液から（メタ）アク
リル酸を、蒸留、溶剤抽出等の工程を組み合わせること
により分離、精製するようにしており、上記接触気相酸
化反応による（メタ）アクリル酸の製造方法には、蒸留
により（メタ）アクリル酸を分離、濃縮、精製等する工
程が含まれている。また、上記以外の（メタ）アクリル
酸の製造方法としては、レッペ法によりアクリル酸を製
造する方法や、アセトンシアンヒドリン法によりメタク
リル酸を製造する方法等も知られている。これらの製造
方法においても、蒸留により（メタ）アクリル酸を分
離、濃縮、精製等する工程が含まれている。Conventionally, as a method for producing (meth) acrylic acid, for example, a method for producing acrylic acid by a catalytic gas phase oxidation reaction of propylene and / or acrolein, a catalytic gas phase oxidation reaction of isobutylene and / or methacrolein. The method of producing methacrylic acid according to the above is often used. In these methods, the reaction product gas obtained by the catalytic gas phase oxidation reaction is cooled and collected with water,
After obtaining an aqueous solution of (meth) acrylic acid containing by-products such as acetic acid and aldehyde, (meth) acrylic acid is separated and purified from this aqueous solution by combining steps such as distillation and solvent extraction. Therefore, the method for producing (meth) acrylic acid by the above catalytic gas phase oxidation reaction includes a step of separating (meth) acrylic acid by distillation, concentrating, purifying and the like. In addition, as a method for producing (meth) acrylic acid other than the above, a method for producing acrylic acid by the Reppe method, a method for producing methacrylic acid by the acetone cyanohydrin method, and the like are known. These manufacturing methods also include the steps of separating, concentrating, purifying, etc. (meth) acrylic acid by distillation.
【０００４】（メタ）アクリル酸は、前述したように、
光や熱等により非常に重合しやすい性質を持つ。そのた
め、特に、上述した蒸留工程等のような高温状態での処
理においては（メタ）アクリル酸の重合性が極めて大き
くなる。したがって、このように重合性の大きい（メ
タ）アクリル酸を工業的に製造する場合、蒸留工程での
これらの酸の重合によるトラブルを防止することは、プ
ロセス操作上、非常に重要な項目であり、特に、これら
の酸を高温下で扱う蒸留工程において有効な重合防止技
術を確立することは、そのプロセスを長期間連続的に、
かつ、安定して運転する上で必要不可欠の事項である。
本発明者らの知見によれば、上述した蒸留工程のうち、
脱水工程（水分離工程）時が最も重合が起こりやすく、
このことが蒸留塔を含む製造装置の連続操業を妨げる主
要因となっている。(Meth) acrylic acid is, as described above,
It has the property of being very easily polymerized by light and heat. Therefore, the polymerizability of (meth) acrylic acid becomes extremely large especially in the treatment in a high temperature state such as the above-mentioned distillation step. Therefore, when industrially producing such highly polymerizable (meth) acrylic acid, preventing troubles due to polymerization of these acids in the distillation step is a very important item in process operation. In particular, establishing an effective polymerization prevention technique in the distillation step in which these acids are treated at high temperature is to continuously process the process for a long period of time.
It is also an essential item for stable operation.
According to the knowledge of the present inventors, among the above-mentioned distillation steps,
Polymerization is most likely to occur during the dehydration step (water separation step),
This is the main factor that hinders continuous operation of manufacturing equipment including the distillation column.
【０００５】（メタ）アクリル酸を蒸留塔を用いて分
離、濃縮、精製等の操作に付した際に、これらの酸が重
合して重合物を生成しやすい箇所は、トレーの裏側、泡
鐘の内側、ダウンカマーの裏側、塔の内側の窪み等のよ
うに液にぬれにくい場所や、トレー組み込み用の金具
（ボルト、ナット等）やパッキング部等のように液の淀
みがちな箇所がほとんどである。前記重合物は、（メ
タ）アクリル酸、水、通常の有機溶媒等に溶けにくく、
また、一度塔内に生成すると、それが重合の核となって
次第に蓄積し、最後には、塔内がそれによって閉塞され
てしまい、製造装置の運転続行が不可能となる。しか
も、これらの蓄積された重合物は、その除去に非常な困
難を伴う。[0005] When (meth) acrylic acid is subjected to operations such as separation, concentration, and purification using a distillation column, the locations where these acids are likely to polymerize to form a polymerized product are located on the back side of the tray and the foam bell. Most of the places where the liquid does not get wet, such as the inside of the rack, the back of the downcomer, the inside of the tower, etc. Is. The polymer is difficult to dissolve in (meth) acrylic acid, water, ordinary organic solvents,
Further, once it is generated in the tower, it becomes a nucleus of polymerization and gradually accumulates, and finally, the inside of the tower is blocked by it, and it becomes impossible to continue the operation of the manufacturing apparatus. Moreover, these accumulated polymers are very difficult to remove.
【０００６】従来、（メタ）アクリル酸を製造する際の
蒸留工程における（メタ）アクリル酸の重合を防止する
対策としては、重合防止剤の存在下で蒸留を行う方法が
採られている。そのような重合防止剤としては、ハイド
ロキノン、メトキノン（ｐ−メトキシフェノールとも言
う）、クレゾール、フェノール、ｔ−ブチルカテコー
ル、ジフェニルアミン、フェノチアジン、およびメチレ
ンブルーからなる群の中から選ばれた少なくとも１種の
化合物と、ジメチルジチオカルバミン酸銅、ジエチルジ
チオカルバミン酸銅、およびジブチルジチオカルバミン
酸銅からなる群の中から選ばれた少なくとも１種のジチ
オカルバミン酸銅塩と、分子状酸素とからなる重合防止
剤（Ａ）が知られている（アクリル酸については特開昭
４９−８５０１６号公報参照、メタクリル酸については
特公昭５７−６１０１５号公報参照）。また、（メタ）
アクリル酸の上記以外の重合防止剤としては、酢酸マン
ガン等のマンガン塩からなる重合防止剤（Ｂ−１）、酢
酸マンガン等のマンガン塩とハイドロキノンおよび／ま
たはメトキノンとからなる重合防止剤（Ｂ−２）、酢酸
マンガン等のマンガン塩と分子状酸素とからなる重合防
止剤（Ｂ−３）、酢酸マンガン等のマンガン塩とハイド
ロキノンおよび／またはメトキノンと分子状酸素とから
なる重合防止剤（Ｂ−４）が知られている（いずれも特
開昭５１−９８２１１号公報参照）。Conventionally, as a measure for preventing the polymerization of (meth) acrylic acid in the distillation step in producing (meth) acrylic acid, a method of carrying out distillation in the presence of a polymerization inhibitor has been adopted. As such a polymerization inhibitor, at least one compound selected from the group consisting of hydroquinone, metoquinone (also referred to as p-methoxyphenol), cresol, phenol, t-butylcatechol, diphenylamine, phenothiazine, and methylene blue. And a polymerization inhibitor (A) consisting of molecular oxygen and at least one dithiocarbamic acid copper salt selected from the group consisting of copper dimethyldithiocarbamate, copper diethyldithiocarbamate, and copper dibutyldithiocarbamate. (See JP-A-49-85016 for acrylic acid and JP-B-57-61015 for methacrylic acid). Also (meta)
As the polymerization inhibitor of acrylic acid other than the above, a polymerization inhibitor composed of a manganese salt such as manganese acetate (B-1), a polymerization inhibitor composed of a manganese salt such as manganese acetate and hydroquinone and / or metquinone (B- 2), a polymerization inhibitor consisting of manganese salt such as manganese acetate and molecular oxygen (B-3), a polymerization inhibitor consisting of manganese salt such as manganese acetate and hydroquinone and / or metoquinone and molecular oxygen (B- 4) is known (see JP-A-51-98211).
【０００７】[0007]
【発明が解決しようとする課題】ところが、その後の検
討で、前述した公知の重合防止剤（Ａ）および（Ｂ−
１）〜（Ｂ−４）は、以下のような問題点を有すること
がわかった。すなわち、前述した特開昭４９−８５０１
６号公報および特公昭５７−６１０１５号公報に記載の
重合防止剤（Ａ）は、接触気相酸化反応により（メタ）
アクリル酸を製造する際の蒸留工程における（メタ）ア
クリル酸の水溶液の共沸分離塔（水分離塔）のように、
フィード組成中に水、酢酸、およびアルデヒド類を含む
ために（メタ）アクリル酸の重合が極めて起こりやすい
場合においては、重合防止効果が低く、そのため、蒸留
中にポップコーンポリマーや粘性ポリマーが発生して、
蒸留塔を含む製造装置の長期連続操業ができなくなると
いう問題があった。However, in the subsequent studies, the known polymerization inhibitors (A) and (B-
It was found that 1) to (B-4) had the following problems. That is, the above-mentioned JP-A-49-8501.
The polymerization inhibitor (A) described in JP-B No. 6 and JP-B-57-61015 is (meth) by a catalytic gas phase oxidation reaction.
Like an azeotropic separation tower (water separation tower) of an aqueous solution of (meth) acrylic acid in the distillation step when producing acrylic acid,
When the polymerization of (meth) acrylic acid is extremely likely to occur because water, acetic acid, and aldehydes are contained in the feed composition, the effect of preventing polymerization is low, and therefore popcorn polymer or viscous polymer is generated during distillation. ,
There has been a problem that the manufacturing apparatus including the distillation column cannot operate continuously for a long period of time.
【０００８】一方、前記特開昭５１−９８２１１号公報
に記載の重合防止剤（Ｂ−１）〜（Ｂ−４）は、（メ
タ）アクリル酸の製品に対しては充分な重合防止効果は
あるが、上記重合防止剤（Ａ）の場合と同様に、接触気
相酸化反応により（メタ）アクリル酸を製造する際の蒸
留工程における（メタ）アクリル酸の水溶液の共沸分離
塔のように（メタ）アクリル酸の重合が極めて起こりや
すい場合においては、重合防止効果が充分でなく、その
ため、蒸留中にポップコーンポリマーや粘性ポリマーが
発生して、製造装置の長期連続操業ができなくなるとい
う問題があった。On the other hand, the polymerization inhibitors (B-1) to (B-4) described in JP-A-51-98211 do not have a sufficient polymerization inhibitory effect on a (meth) acrylic acid product. However, as in the case of the above polymerization inhibitor (A), like the azeotropic separation column of the aqueous solution of (meth) acrylic acid in the distillation step when producing (meth) acrylic acid by the catalytic gas phase oxidation reaction, When the polymerization of (meth) acrylic acid is extremely likely to occur, the effect of preventing the polymerization is not sufficient, and therefore, there is a problem that popcorn polymers and viscous polymers are generated during distillation, which makes it impossible to operate the production apparatus for a long period of time. there were.
【０００９】このような事情に鑑み、この発明は、ビニ
ル化合物の中でも特に重合しやすい（メタ）アクリル酸
に対し、その製造装置の長期連続操業を可能にするとと
もに、（メタ）アクリル酸製品の輸送時や貯蔵時等の重
合防止にも優れた方法を提供することを課題とする。In view of such circumstances, the present invention enables long-term continuous operation of a production apparatus for (meth) acrylic acid, which is particularly easy to polymerize among vinyl compounds, and also provides a (meth) acrylic acid product. It is an object of the present invention to provide a method which is excellent in preventing polymerization during transportation or storage.
【００１０】[0010]
【課題を解決するための手段】前記課題を解決するた
め、発明者らは、種々検討を重ねた。その結果、重合防
止剤として、後で詳しく述べる、マンガン塩と、ジアル
キルジチオカルバミン酸銅塩と、フェノール系化合物
と、フェノチアジンとの４者を併用することとし、この
ようにすれば、前述した従来の重合防止方法に比べて、
前記４者の重合防止剤の、予想をはるかに超えた相乗作
用により重合防止効果が向上し、製造装置の長期連続操
業が可能になることを実験により確認して、この発明を
完成した。In order to solve the above problems, the inventors have made various studies. As a result, as the polymerization inhibitor, four members of manganese salt, dialkyldithiocarbamic acid copper salt, phenolic compound, and phenothiazine, which will be described in detail later, are used in combination. Compared with the polymerization prevention method,
The present invention was completed by confirming by experiments that the polymerization inhibitory effect of the above four polymerization inhibitors is improved by a synergistic action far beyond the expectation, and long-term continuous operation of the production apparatus is enabled.
【００１１】したがって、この発明にかかる（メタ）ア
クリル酸の重合防止方法は、酢酸マンガンおよびオクタ
ン酸マンガンのうちの少なくとも１種からなるマンガン
塩と、ジメチルジチオカルバミン酸銅塩、ジエチルジチ
オカルバミン酸銅塩、ジプロピルジチオカルバミン酸銅
塩およびジブチルジチオカルバミン酸銅塩のうちの少な
くとも１種からなるジアルキルジチオカルバミン酸銅塩
と、メトキノンおよびハイドロキノンのうちの少なくと
も１種からなるフェノール系化合物と、フェノチアジン
との４者の重合防止剤を併用する方法である。Therefore, the method for preventing polymerization of (meth) acrylic acid according to the present invention comprises a manganese salt of at least one of manganese acetate and manganese octanoate, a dimethyldithiocarbamate copper salt, a diethyldithiocarbamate copper salt, Four-way polymerization of dialkyldithiocarbamic acid copper salt consisting of at least one kind of dipropyldithiocarbamic acid copper salt and dibutyldithiocarbamic acid copper salt, a phenolic compound consisting of at least one kind of methoquinone and hydroquinone, and phenothiazine This is a method of using an inhibitor together.
【００１２】この発明では、前述のように、マンガン塩
と、ジアルキルジチオカルバミン酸銅塩と、フェノール
系化合物と、フェノチアジンとの４者の重合防止剤を併
用する。これら４者の重合防止剤のうち、フェノチアジ
ン以外の重合防止剤の詳細は、下記の通りである。In the present invention, as described above, the four polymerization inhibitors of manganese salt, copper dialkyldithiocarbamic acid, phenolic compound and phenothiazine are used in combination. Among the four polymerization inhibitors, the details of the polymerization inhibitors other than phenothiazine are as follows.
【００１３】マンガン塩としては、酢酸マンガンおよび
オクタン酸マンガンのうちの少なくとも１種が用いら
れ、これらは有水塩であっても無水塩であってもよい。
ジアルキルジチオカルバミン酸銅塩としては、ジメチル
ジチオカルバミン酸銅塩、ジエチルジチオカルバミン酸
銅塩、ジプロピルジチオカルバミン酸銅塩およびジブチ
ルジチオカルバミン酸銅塩のうちの少なくとも１種が用
いられる。As the manganese salt, at least one of manganese acetate and manganese octoate is used, which may be a water-containing salt or an anhydrous salt.
As the dialkyldithiocarbamic acid copper salt, at least one selected from dimethyldithiocarbamic acid copper salt, diethyldithiocarbamic acid copper salt, dipropyldithiocarbamic acid copper salt and dibutyldithiocarbamic acid copper salt is used.
【００１４】フェノール系化合物としては、メトキノン
およびハイドロキノンのうちの少なくとも１種が用いら
れる。この発明では、重合防止剤として前述の４者のみ
を用いても充分優れた重合防止効果が得られるが、必要
に応じ、重合防止剤としてさらに分子状酸素を用いても
よく、その場合は、相乗効果により、さらに優れた重合
防止効果が得られる。As the phenolic compound, at least one of methquinone and hydroquinone is used. In the present invention, a sufficiently excellent polymerization inhibiting effect can be obtained by using only the above-mentioned four members as the polymerization inhibitor, but if necessary, molecular oxygen may be further used as the polymerization inhibitor. In that case, Due to the synergistic effect, a further excellent polymerization inhibiting effect can be obtained.
【００１５】この発明は、ビニル化合物の中でも特に重
合しやすい（メタ）アクリル酸に対して好適に用いられ
る。この発明が適用される（メタ）アクリル酸の置かれ
る条件については、特に限定はされないが、たとえば、
（メタ）アクリル酸の製造時の反応器、蒸留塔、凝縮
塔、あるいは、精製した（メタ）アクリル酸の貯蔵槽等
に適用できる。より具体的には、たとえば、接触気相酸
化反応により（メタ）アクリル酸を製造する場合に関し
て説明すれば、（メタ）アクリル酸の精留塔、（メタ）
アクリル酸の共沸分離塔、（メタ）アクリル酸と酢酸等
の軽質分との分離塔などの諸蒸留工程、アクロレインや
メタクロレイン等の軽質分のストリッパー等の蒸留操作
を含む諸工程において、重合防止剤を（メタ）アクリル
酸と共存させることによって有効に適用される。The present invention is preferably used for (meth) acrylic acid which is particularly easy to polymerize among vinyl compounds. The conditions under which (meth) acrylic acid to which the present invention is applied are not particularly limited, but for example,
It can be applied to a reactor at the time of producing (meth) acrylic acid, a distillation column, a condensing column, a purified (meth) acrylic acid storage tank, or the like. More specifically, for example, in the case of producing (meth) acrylic acid by a catalytic gas phase oxidation reaction, a (meth) acrylic acid rectification column, (meth)
Polymerization in various distillation processes such as an azeotropic separation column of acrylic acid, a separation column of (meth) acrylic acid and light components such as acetic acid, and a distillation process such as strippers of light components such as acrolein and methacrolein. It is effectively applied by making the inhibitor coexist with (meth) acrylic acid.
【００１６】この発明では、通常、各重合防止成分を
（メタ）アクリル酸またはその溶液に添加して用いる。
各重合防止成分の添加方法は、特に限定されない。たと
えば、固体または粉体等の形で直接添加してもよいし、
適当な有機溶剤に溶解した形で添加してもよい。なお、
必要に応じて用いられる分子状酸素については、エアー
バブリング法等により（メタ）アクリル酸またはその溶
液に直接混入してもよいし、他の重合防止成分の溶液に
溶けた形で（メタ）アクリル酸またはその溶液に間接的
に混入してもよい。また、各重合防止成分は、（メタ）
アクリル酸またはその溶液に別個に添加してもよいし、
複数の重合防止成分の混合物の形で添加してもよい。In the present invention, each polymerization inhibitor is usually used by adding it to (meth) acrylic acid or its solution.
The method of adding each polymerization inhibitor is not particularly limited. For example, it may be added directly in the form of solid or powder,
You may add in the form melt | dissolved in a suitable organic solvent. In addition,
The molecular oxygen used as necessary may be directly mixed with (meth) acrylic acid or a solution thereof by an air bubbling method or the like, or may be dissolved in a solution of another polymerization inhibiting component in the form of (meth) acrylic acid. It may be indirectly mixed with the acid or its solution. Further, each polymerization inhibitor component is (meth)
May be added separately to acrylic acid or its solution,
It may be added in the form of a mixture of a plurality of polymerization inhibiting components.
【００１７】具体的には、たとえば、（メタ）アクリル
酸の製造時の蒸留工程においては、分子状酸素以外の重
合防止成分は、（メタ）アクリル酸、および、これらの
酸の製造工程において用いられる有機溶剤に比較的溶解
しやすいので、供給液や還流液に溶かして工程中へ導入
することができる。また、分子状酸素は、蒸留塔や分離
塔やストリッパーの塔底および／またはリボイラーから
ガス状で送入される。Specifically, for example, in the distillation step during the production of (meth) acrylic acid, the polymerization preventing components other than molecular oxygen are used in the production step of (meth) acrylic acid and these acids. Since it is relatively easily dissolved in the organic solvent to be used, it can be dissolved in the supply liquid or the reflux liquid and introduced into the process. Further, molecular oxygen is fed in as a gas from a distillation column, a separation column, the bottom of a stripper, and / or a reboiler.
【００１８】この発明で使用される重合防止剤の量につ
いては、一般に、操作条件等により変化し、特に限定は
されないが、具体的には、前述の、マンガン塩と、ジア
ルキルジチオカルバミン酸銅塩と、フェノール系化合物
と、フェノチアジンとの４者の重合防止剤の総量が、
（メタ）アクリル酸の蒸発蒸気量に対して１００〜１０
００ppm （重量基準）とするのが好ましい。The amount of the polymerization inhibitor used in the present invention generally varies depending on the operating conditions and is not particularly limited, but specifically, the above-mentioned manganese salt and dialkyldithiocarbamic acid copper salt are used. , The total amount of the four types of polymerization inhibitors of the phenolic compound and phenothiazine,
100 to 10 with respect to the amount of vaporized vapor of (meth) acrylic acid
It is preferably set to 00 ppm (weight basis).
【００１９】さらに、これら４者の重合防止剤の個々の
使用量については、マンガン塩として１５〜３００ppm
、ジアルキルジチオカルバミン酸銅塩として１０〜２
００ppm 、フェノール系化合物として３０〜６００ppm
およびフェノチアジン３０〜６００ppm の範囲が好まし
い（「ppm 」はいずれも（メタ）アクリル酸の蒸発蒸気
量に対する重量割合）。Further, the amount of each of the four polymerization inhibitors used is 15 to 300 ppm as a manganese salt.
, Dialkyldithiocarbamic acid copper salt 10-2
00ppm, 30-600ppm as phenolic compound
And the range of 30 to 600 ppm of phenothiazine is preferable ("ppm" is the weight ratio with respect to the vaporized vapor amount of (meth) acrylic acid).
【００２０】また、この発明を実施する場合、前述した
ように、分子状酸素の存在下で行うと効果が著しく増加
する傾向にある。したがって、（メタ）アクリル酸の蒸
発蒸気量に対して０．１〜１．０容量％程度の分子状酸
素を投入するのが望ましい。Further, when the present invention is carried out, the effect tends to remarkably increase if it is carried out in the presence of molecular oxygen, as described above. Therefore, it is desirable to add about 0.1 to 1.0% by volume of molecular oxygen with respect to the amount of evaporated vapor of (meth) acrylic acid.
【００２１】[0021]
【作用】重合防止剤として、前述した、マンガン塩と、
ジアルキルジチオカルバミン酸銅塩と、フェノール系化
合物と、フェノチアジンとの４者を併用すると、これら
４者の重合防止剤のうちの少なくとも１者が欠けた場合
に比べて、４者の重合防止剤の併用による相乗効果によ
り重合防止効果が大幅に向上し、（メタ）アクリル酸が
極めて重合しやすい条件下でも（メタ）アクリル酸の重
合を充分防止するため、（メタ）アクリル酸の蒸留塔を
含む（メタ）アクリル酸の製造装置の長期連続操業を可
能にするとともに、（メタ）アクリル酸製品の輸送時や
貯蔵時等にも優れた重合防止効果を発揮する。[Function] As a polymerization inhibitor, the aforementioned manganese salt,
When four of the dialkyldithiocarbamic acid copper salt, the phenolic compound and the phenothiazine are used in combination, the combined use of the four polymerization inhibitors compared to the case where at least one of these four polymerization inhibitors is lacking. In order to sufficiently prevent the polymerization of (meth) acrylic acid even under conditions where (meth) acrylic acid is extremely likely to be polymerized, a distillation column for (meth) acrylic acid is included ( It enables a long-term continuous operation of a (meth) acrylic acid production apparatus, and exhibits an excellent polymerization-preventing effect during transportation and storage of (meth) acrylic acid products.
【００２２】[0022]
【実施例】以下に、この発明の具体的な実施例を比較例
と併せて示すが、この発明は、下記実施例に限定されな
い。なお、下記実施例および比較例中の単位ppm は、い
ずれも重量を基準とする。 −実施例１〜２および比較例１〜４− あらかじめ蒸留により重合防止剤を除去した製品アクリ
ル酸を試験ブランク液として用いた。このブランク液２
mlを試験管に取り、これに、表１に示す種類および量の
重合防止剤を添加して、調製液とした。次いで、この試
験管内を減圧にした後、１００℃に保ったオイルバスに
試験管を浸漬し、この浸漬開始からアクリル酸が重合す
るまでの時間（重合時間）を目視により測定した。その
結果を表１に示した。EXAMPLES Specific examples of the present invention will be shown below together with comparative examples, but the present invention is not limited to the following examples. The unit ppm in the following examples and comparative examples is based on weight. -Examples 1-2 and Comparative Examples 1-4-Product acrylic acid from which the polymerization inhibitor was removed by distillation beforehand was used as a test blank solution. This blank liquid 2
ml was taken in a test tube, and the type and amount of the polymerization inhibitor shown in Table 1 were added thereto to prepare a preparation liquid. Next, after decompressing the inside of the test tube, the test tube was immersed in an oil bath maintained at 100 ° C., and the time from the start of the immersion until polymerization of acrylic acid (polymerization time) was visually measured. The results are shown in Table 1.
【００２３】[0023]
【表１】 [Table 1]
【００２４】上記表１中、重合防止剤の添加量（ppm)は
重合前のアクリル酸量を基準とするものであり、ＣＢ、
ＨＱ、ＭｎＡｃおよびＰＴＺはそれぞれジブチルジチオ
カルバミン酸銅塩、ハイドロキノン、酢酸マンガンおよ
びフェノチアジンを表す。表１にみるように、重合防止
剤としてＣＢ、ＨＱ、ＭｎＡｃおよびＰＴＺの４者のう
ちのいずれか１者が欠けても、これらを４者とも用いた
場合と比べて重合時間が短くなり、重合防止効果が低下
している。このことから、上記重合防止剤を４者とも用
いることが好適であることが確認された。特に実施例２
では、比較例１〜４に比べて、重合防止剤の総量が少な
いのにも関わらず重合時間が長くなっており、重合防止
効果が高い。In Table 1, the addition amount (ppm) of the polymerization inhibitor is based on the amount of acrylic acid before polymerization, and CB,
HQ, MnAc and PTZ represent dibutyldithiocarbamic acid copper salt, hydroquinone, manganese acetate and phenothiazine, respectively. As shown in Table 1, even if any one of CB, HQ, MnAc and PTZ is lacking as a polymerization inhibitor, the polymerization time becomes shorter as compared with the case where all of them are used. The polymerization prevention effect is reduced. From this, it was confirmed that it is preferable to use the above-mentioned polymerization inhibitors for all four types. Especially Example 2
In comparison with Comparative Examples 1 to 4, although the total amount of the polymerization inhibitor was small, the polymerization time was long and the polymerization inhibitory effect was high.
【００２５】−実施例３および比較例５〜８− 上部に留出管を備え、中央部に原料供給管を備えた充填
塔を用い、分子状酸素とそれ以外の重合防止剤の存在下
でアクリル酸水溶液の共沸分離の蒸留実験を行った。操
作圧１６０mmHgで操作し、８時間の運転時間において塔
内に発生したポリマーを減圧乾燥して恒量にした後、そ
の量を測定することにより、重合防止剤の効果をみた。-Example 3 and Comparative Examples 5-8- Using a packed column equipped with a distillation pipe in the upper part and a raw material supply pipe in the central part, in the presence of molecular oxygen and other polymerization inhibitors. Distillation experiments of azeotropic separation of acrylic acid aqueous solution were conducted. After operating at an operating pressure of 160 mmHg and drying the polymer generated in the tower under reduced pressure for a running time of 8 hours to a constant weight, the effect of the polymerization inhibitor was confirmed by measuring the amount.
【００２６】分子状酸素以外の重合防止剤は表２に示す
種類および量を添加溶解した形で還流液から塔内に投入
し、分子状酸素は表２に示す量を塔底部に供給した。な
お、分子状酸素以外の重合防止剤と分子状酸素の各量は
アクリル酸の蒸発蒸気量を基準とするものである。供給
原料としては、プロピレンの接触気相酸化反応によって
得られた、水３０重量％および酢酸２．５重量％を含む
アクリル酸水溶液を用い、還流液としてはメチルイソブ
チルケトンを用い、塔頂温度４９℃、塔底温度９７℃の
条件下で蒸留した。Polymerization inhibitors other than molecular oxygen were added and dissolved in the form and amount shown in Table 2 from the reflux liquid into the column, and molecular oxygen was supplied in the column amount shown in Table 2. The amounts of the polymerization inhibitor other than the molecular oxygen and the molecular oxygen are based on the amount of evaporated vapor of acrylic acid. Acrylic acid aqueous solution containing 30% by weight of water and 2.5% by weight of acetic acid, which was obtained by catalytic vapor phase oxidation reaction of propylene, was used as a feed material, methyl isobutyl ketone was used as a reflux liquid, and a top temperature of 49 Distillation was carried out under the conditions of ℃ and column bottom temperature of 97 ℃.
【００２７】定常状態における塔底抜き出し液組成は、
アクリル酸９７重量％、酢酸０．５重量％、その他２．
５重量％であった。還流液は留出組成をリサイクルして
用いた。結果を表２に示した。The composition of the liquid extracted from the bottom of the column in the steady state is
Acrylic acid 97% by weight, acetic acid 0.5% by weight, others 2.
It was 5% by weight. The reflux liquid was used by recycling the distillate composition. The results are shown in Table 2.
【００２８】[0028]
【表２】 [Table 2]
【００２９】上記表２中、ＣＭ、ＨＱ、ＭｎＯｃおよび
ＰＴＺはそれぞれジメチルジチオカルバミン酸銅塩、ハ
イドロキノン、オクタン酸マンガンおよびフェノチアジ
ンを表す。表２にみるように、分子状酸素以外の重合防
止剤ＣＭ、ＨＱ、ＭｎＯｃおよびＰＴＺのうちのいずれ
か１者が欠けても、これらを４者とも用いた場合と比べ
てポリマーの発生量が多くなり、重合防止効果が低下し
ている。このことから、ＣＭ、ＨＱ、ＭｎＯｃおよびＰ
ＴＺを４者とも用いることが好適であることが確認され
た。In Table 2 above, CM, HQ, MnOc and PTZ respectively represent dimethyldithiocarbamic acid copper salt, hydroquinone, manganese octanoate and phenothiazine. As shown in Table 2, even if any one of the polymerization inhibitors CM, HQ, MnOc, and PTZ other than the molecular oxygen is lacking, the amount of polymer generated is smaller than that when all of them are used. As a result, the effect of preventing polymerization is reduced. From this, CM, HQ, MnOc and P
It was confirmed that it is preferable to use TZ with all four persons.
【００３０】−実施例４〜５および比較例９〜１２− あらかじめ蒸留により重合防止剤を除去した製品メタク
リル酸を試験ブランク液として用いた。このブランク液
２mlを試験管に取り、これに、表３に示す種類および量
の重合防止剤を添加して、調製液とした。次いで、この
試験管内を減圧にした後、１３０℃に保ったオイルバス
に試験管を浸漬し、この浸漬開始からメタクリル酸が重
合するまでの時間（重合時間）を目視により測定した。
その結果を表３に示した。Examples 4 to 5 and Comparative Examples 9 to 12 Methacrylic acid, the product of which the polymerization inhibitor was removed by distillation in advance, was used as a test blank solution. 2 ml of this blank solution was placed in a test tube, and the type and amount of the polymerization inhibitor shown in Table 3 were added thereto to prepare a preparation solution. Next, after decompressing the inside of the test tube, the test tube was immersed in an oil bath kept at 130 ° C., and the time from the start of the immersion until the polymerization of methacrylic acid (polymerization time) was visually measured.
The results are shown in Table 3.
【００３１】[0031]
【表３】 [Table 3]
【００３２】上記表３中、重合防止剤の添加量（ppm)は
重合前のメタクリル酸量を基準とするものであり、Ｃ
Ｅ、ＭＱ、ＭｎＡｃおよびＰＴＺはそれぞれジエチルジ
チオカルバミン酸銅塩、メトキノン、酢酸マンガンおよ
びフェノチアジンを表す。表３にみるように、重合防止
剤としてＣＥ、ＭＱ、ＭｎＡｃおよびＰＴＺの４者のう
ちのいずれか１者が欠けても、これらを４者とも用いた
場合と比べて重合時間が短くなり、重合防止効果が低下
している。このことから、上記重合防止剤を４者とも用
いることが好適であることが確認された。特に実施例５
では、比較例９〜１２に比べて、重合防止剤の総量が少
ないのにも関わらず重合時間が長くなっており、重合防
止効果が高い。In Table 3, the addition amount (ppm) of the polymerization inhibitor is based on the amount of methacrylic acid before polymerization, and C
E, MQ, MnAc and PTZ represent diethyldithiocarbamic acid copper salt, methoquinone, manganese acetate and phenothiazine, respectively. As shown in Table 3, even if one of CE, MQ, MnAc and PTZ is lacking as a polymerization inhibitor, the polymerization time becomes shorter as compared with the case where all of them are used. The polymerization prevention effect is reduced. From this, it was confirmed that it is preferable to use the above-mentioned polymerization inhibitors for all four types. Especially Example 5
In comparison with Comparative Examples 9 to 12, although the total amount of the polymerization inhibitor was small, the polymerization time was long and the polymerization inhibitory effect was high.
【００３３】−実施例６− ５０段のステンレス製シーブトレイを段間隔１４７mmで
内装し、上部に留出管を備え、中央部に原料供給管を備
えた内径１０５mmの蒸留塔を使用し、アクリル酸水溶液
の共沸分離の連続運転を行った。使用した重合防止剤
は、酢酸マンガン、ジブチルジチオカルバミン酸銅塩、
ハイドロキノン、フェノチアジンおよび分子状酸素であ
った。酢酸マンガン、ジブチルジチオカルバミン酸銅
塩、ハイドロキノンおよびフェノチアジンはいずれも塔
頂から塔内へ導入した。分子状酸素は塔底部に所定量供
給した。各重合防止剤の使用量は、アクリル酸蒸発蒸気
量に対して、酢酸マンガンが４５ppm 、ジブチルジチオ
カルバミン酸銅塩が３０ppm 、ハイドロキノンが１００
ppm 、フェノチアジンが１００ppm であった。また、投
入酸素量は、アクリル酸蒸発蒸気量に対して０．３容量
％とした。Example 6 A 50-stage stainless steel sieve tray was internally installed with a step interval of 147 mm, a distillation column having an inner diameter of 105 mm equipped with a distillation pipe in the upper part and a raw material supply pipe in the central part was used, and acrylic acid was used. Continuous operation of azeotropic separation of the aqueous solution was performed. The polymerization inhibitor used was manganese acetate, dibutyldithiocarbamic acid copper salt,
It was hydroquinone, phenothiazine and molecular oxygen. Manganese acetate, dibutyldithiocarbamic acid copper salt, hydroquinone and phenothiazine were all introduced into the tower from the top. A predetermined amount of molecular oxygen was supplied to the bottom of the column. The amount of each polymerization inhibitor used was 45 ppm of manganese acetate, 30 ppm of copper dibutyldithiocarbamate, and 100 parts of hydroquinone, relative to the amount of vaporized acrylic acid vapor.
ppm and phenothiazine were 100 ppm. The amount of oxygen input was 0.3% by volume with respect to the amount of vaporized acrylic acid vapor.
【００３４】重合防止効果は、塔内の圧損失、フラッデ
ィングまたは塔の解体点検によって確認した。供給原料
として、プロピレンの接触気相酸化反応によって得られ
た、水を３０重量％および酢酸を２．５重量％含むアク
リル酸を用い、還流液としてメチルイソブチルケトンを
用い、塔頂温度４６℃、塔底温度９７℃、塔頂圧１１２
mmHg、供給液量１０．５６リットル／hr、還流比（Ｒ／
Ｄ）＝０．９２（モル基準）の条件下で蒸留した。The effect of preventing polymerization was confirmed by pressure loss in the tower, flooding, or disassembly inspection of the tower. Acrylic acid containing 30% by weight of water and 2.5% by weight of acetic acid, which was obtained by a catalytic gas phase oxidation reaction of propylene, was used as a feed material, methyl isobutyl ketone was used as a reflux liquid, and an overhead temperature was 46 ° C. Tower bottom temperature 97 ° C, tower top pressure 112
mmHg, supply liquid amount 10.56 liter / hr, reflux ratio (R /
It distilled under the conditions of D) = 0.92 (mol basis).
【００３５】定常状態における塔底抜き出し液組成は、
アクリル酸９７．０重量％、酢酸０．５重量％、その他
２．５重量％であった。還流液は、留出油相をリサイク
ルして用いた。この条件で約１４日間連続運転したとこ
ろ、常に安定した状態が得られ、運転停止後、蒸留塔内
の点検を行った結果においてもポリマーの発生は全く認
められなかった。The composition of the liquid extracted from the bottom of the column in a steady state is
Acrylic acid was 97.0% by weight, acetic acid was 0.5% by weight, and others were 2.5% by weight. The reflux liquid was used by recycling the distillate oil phase. When continuously operated under these conditions for about 14 days, a stable state was always obtained, and even after the operation was stopped, the inside of the distillation column was inspected, and no polymer was found at all.
【００３６】[0036]
【発明の効果】この発明によれば、前記特定の重合防止
剤４者を併用するため、それらのうちの少なくとも１者
が欠けた場合と比べて、ビニル化合物の中でも特に重合
しやすい（メタ）アクリル酸に対する重合防止効果が大
幅に向上し、（メタ）アクリル酸が極めて重合しやすい
条件下でさえも（メタ）アクリル酸の重合が充分に防止
されて、（メタ）アクリル酸の蒸留塔を含む（メタ）ア
クリル酸の製造装置の長期連続操業が可能になる。ま
た、この発明は、（メタ）アクリル酸の製造時ばかりで
なく、その製品の輸送時や貯蔵時等にも適用できる。EFFECTS OF THE INVENTION According to the present invention, since the above-mentioned four specific polymerization inhibitors are used in combination, the vinyl compound is particularly easily polymerized (meth) as compared with the case where at least one of them is lacking. Polymerization of (meth) acrylic acid is sufficiently prevented even under conditions where (meth) acrylic acid is extremely easy to polymerize, and the effect of preventing polymerization of acrylic acid is greatly improved. It enables long-term continuous operation of the manufacturing equipment of (meth) acrylic acid containing it. Further, the present invention can be applied not only during the production of (meth) acrylic acid but also during the transportation and storage of the product.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 赤沢 陽治 兵庫県姫路市網干区興浜字西沖992番地の １ 株式会社日本触媒姫路製造所内 (72)発明者 馬場 将夫 兵庫県姫路市網干区興浜字西沖992番地の １ 株式会社日本触媒姫路製造所内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoji Akazawa, 992, Nishioki, Nishihama, Aboshi-ku, Himeji-shi, Hyogo Prefecture 1 Inside Nihon Shatai Co., Ltd. Himeji Factory (72) Masao Baba, 992, Nishi-oki, Ohamaji, Aboshi-ku, Himeji, Hyogo Prefecture 1 Inside Nippon Shokubai Himeji Factory
Claims (1)
のうちの少なくとも１種からなるマンガン塩と、ジメチ
ルジチオカルバミン酸銅塩、ジエチルジチオカルバミン
酸銅塩、ジプロピルジチオカルバミン酸銅塩およびジブ
チルジチオカルバミン酸銅塩のうちの少なくとも１種か
らなるジアルキルジチオカルバミン酸銅塩と、メトキノ
ンおよびハイドロキノンのうちの少なくとも１種からな
るフェノール系化合物と、フェノチアジンとの４者の重
合防止剤を併用する（メタ）アクリル酸の重合防止方
法。1. A manganese salt consisting of at least one of manganese acetate and manganese octanoate, among dimethyldithiocarbamate copper salt, diethyldithiocarbamate copper salt, dipropyldithiocarbamate copper salt and dibutyldithiocarbamate copper salt. A method for inhibiting polymerization of (meth) acrylic acid, which comprises using at least one dialkyldithiocarbamic acid copper salt, a phenolic compound comprising at least one of methoquinone and hydroquinone, and phenothiazine in combination with four polymerization inhibitors.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP863093A JP2574109B2 (en) | 1993-01-21 | 1993-01-21 | Method for preventing polymerization of (meth) acrylic acid |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP863093A JP2574109B2 (en) | 1993-01-21 | 1993-01-21 | Method for preventing polymerization of (meth) acrylic acid |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH06211735A true JPH06211735A (en) | 1994-08-02 |
| JP2574109B2 JP2574109B2 (en) | 1997-01-22 |
Family
ID=11698277
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP863093A Expired - Fee Related JP2574109B2 (en) | 1993-01-21 | 1993-01-21 | Method for preventing polymerization of (meth) acrylic acid |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2574109B2 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1997012851A1 (en) * | 1995-10-02 | 1997-04-10 | Idemitsu Petrochemical Co., Ltd. | Method for inhibiting polymerization of vinyl compounds |
| US6046357A (en) * | 1998-10-02 | 2000-04-04 | Celanese International Corporation | Stabilization and transport of α,β-unsaturated carboxylic acid and removal of stabilizer |
| WO2002051784A1 (en) * | 2000-12-22 | 2002-07-04 | Basf Aktiengesellschaft | Method for producing acrylic acid |
| US7977503B2 (en) | 2007-06-13 | 2011-07-12 | Nippon Shokubai Co., Ltd. | Polymerization inhibition method |
-
1993
- 1993-01-21 JP JP863093A patent/JP2574109B2/en not_active Expired - Fee Related
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1997012851A1 (en) * | 1995-10-02 | 1997-04-10 | Idemitsu Petrochemical Co., Ltd. | Method for inhibiting polymerization of vinyl compounds |
| US5856568A (en) * | 1995-10-02 | 1999-01-05 | Idemitsu Petrochemical Co., Ltd. | Process for inhibiting polymerization of a vinyl compound |
| US6046357A (en) * | 1998-10-02 | 2000-04-04 | Celanese International Corporation | Stabilization and transport of α,β-unsaturated carboxylic acid and removal of stabilizer |
| WO2000020369A1 (en) * | 1998-10-02 | 2000-04-13 | Celanese International Corporation | Stabilization and transport of alpha,beta-unsaturated carboxylic acid and removal of stabilizer |
| US6207859B1 (en) | 1998-10-02 | 2001-03-27 | Celanese International Corporation | Stabilization and transport of α, β-unsaturated carboxylic acid and removal of stabilizer |
| WO2002051784A1 (en) * | 2000-12-22 | 2002-07-04 | Basf Aktiengesellschaft | Method for producing acrylic acid |
| US7977503B2 (en) | 2007-06-13 | 2011-07-12 | Nippon Shokubai Co., Ltd. | Polymerization inhibition method |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2574109B2 (en) | 1997-01-22 |
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