JPS61106546A - Pyrolysis of ethylidenebisamide - Google Patents
Pyrolysis of ethylidenebisamideInfo
- Publication number
- JPS61106546A JPS61106546A JP22599384A JP22599384A JPS61106546A JP S61106546 A JPS61106546 A JP S61106546A JP 22599384 A JP22599384 A JP 22599384A JP 22599384 A JP22599384 A JP 22599384A JP S61106546 A JPS61106546 A JP S61106546A
- Authority
- JP
- Japan
- Prior art keywords
- liquid phase
- eba
- pressure
- temperature
- nva
- 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
Landscapes
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明はポリビニルアセトアミド3等の原料として有用
t、cN−ビニルアセトアミドを得るためのエチリデン
ビスアセトアミドの熱分解法に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for thermally decomposing ethylidene bisacetamide to obtain t,cN-vinylacetamide useful as a raw material for polyvinylacetamide 3 and the like.
アセトアミド(以下A c NH2と略す。)とアセト
アルデヒドとを酸触媒の存在下で縮合させてエチリデン
ビスアセトアミド(以下、EBAと略す。)とし、次い
でこのエチリデンビスアセトアミドをそのままあるいは
精製した後、150〜250℃の温度で熱分解してN−
ビニルアセトアミド(以下、NWAと略す。)を製造す
る方法が知られている( Benl5hai、 Tst
rahedron Letters /1650.45
23Ban l5haiはEBAを蒸留装置中で、40
mH,!i’の減圧下で220℃に加熱してNVA i
得ているが、単に収率(54%)を記載しているのみで
詳細は不明である。Acetamide (hereinafter abbreviated as A c NH2) and acetaldehyde are condensed in the presence of an acid catalyst to produce ethylidene bisacetamide (hereinafter abbreviated as EBA), and then this ethylidene bisacetamide is used as it is or after being purified, 150~ N- is thermally decomposed at a temperature of 250℃.
A method for producing vinyl acetamide (hereinafter abbreviated as NWA) is known (Benlhai, Tst.
rahedron Letters /1650.45
23Ban 15hai is EBA in distillation equipment, 40
mH,! NVA i by heating to 220 °C under reduced pressure of
However, only the yield (54%) is stated and the details are unknown.
米国特許第4.018,826号では、攪拌機を備えた
反応容器に分留管を取付け、 EBAを含有する原料と
触媒(セライト等)を仕込み、40mH,9の圧力下で
、200℃の熱媒体で加熱し、留出してくるNVAを取
得しているが、この方法は操作の最後に触媒の固型物が
残るためにNVAの量産には不向である。In U.S. Patent No. 4,018,826, a fractionating tube is attached to a reaction vessel equipped with a stirrer, a raw material containing EBA and a catalyst (such as Celite) are charged, and the mixture is heated at 200°C under a pressure of 40 mH and 9. NVA is obtained by heating with a medium and distilled out, but this method is unsuitable for mass production of NVA because solid catalyst remains at the end of the operation.
本発明の目的はNVAへの選択率の高いEBAの熱分解
法を提供することにおる。An object of the present invention is to provide a method for thermally decomposing EBA with a high selectivity to NVA.
〔問題点を解決するための手段及び作用〕本発明者等は
加熱を受ける液相に対して蒸発表面の比率を大きくする
と共に、加熱によフ分解と蒸発の起っているEBAOr
)液相から発生する蒸気が再び液相に還流しないように
して外部に取出すことによシ高い選択率で効率よ(NV
Aが得られることを見出し本発明を完成した。[Means and effects for solving the problem] The present inventors have increased the ratio of the evaporation surface to the liquid phase that is heated, and have developed an EBAOr
) By preventing the vapor generated from the liquid phase from returning to the liquid phase and taking it out to the outside, it is possible to achieve high efficiency with high selectivity (NV
They found that A could be obtained and completed the present invention.
すなわち、本発明は伝熱面に接する液相のエチリデンビ
スアセトアミドに対する蒸発表面の割合を0.4 cI
T”/art”以上として、40〜200mH&の圧力
、200〜240℃の温度で加熱し、液相から発生した
蒸気を液相に還流させることなく冷却して補集すること
を特徴とするエチリデンビスアセトアミドの熱分解法で
ある。That is, in the present invention, the ratio of the evaporation surface to ethylidene bisacetamide in the liquid phase in contact with the heat transfer surface is set to 0.4 cI.
T"/art" or more, ethylidene is heated at a pressure of 40 to 200 mH& and a temperature of 200 to 240°C, and the vapor generated from the liquid phase is cooled and collected without refluxing into the liquid phase. This is a method of thermal decomposition of bisacetamide.
本発明の方法によれば、蒸発によシ同伴されるEBAの
割合が先行技術の方法よりも大きくなるためEBAの転
化率は40〜70%と比較的低いがNVAへの選択率は
90チ以上に達する。According to the method of the present invention, the proportion of EBA entrained during evaporation is greater than that of the prior art method, so that the conversion of EBA is relatively low at 40-70%, but the selectivity to NVA is 90%. reach more than that.
転化率の低さは、本出願人が先に提案しているNVAの
水相からの選択的抽出分離方法(特願昭59−1880
98号)によってEBAとAc NH2が濃厚水溶液と
して分離され、回収と再利用が容易に行えるのでNVA
製造上での障害とはならない。The low conversion rate is due to the method of selective extraction and separation of NVA from the aqueous phase previously proposed by the present applicant (Japanese Patent Application No. 1880-1989).
98), EBA and Ac NH2 are separated as a concentrated aqueous solution, which can be easily recovered and reused.
This does not pose a problem in manufacturing.
本発明の方法では操作圧力と温度はEBAの転化率とN
VAへの選択率が好ましい値となるように選定される。In the method of the present invention, the operating pressure and temperature are determined by the conversion rate of EBA and N
It is selected so that the selectivity to VA becomes a preferable value.
すなわち、操作圧力は20〜400mH,!i’、好ま
しくは40〜200wH,9が適当である。圧力が低く
なるとEBAの転化率が低くな9、一方圧力が高すぎ・
る場合にはEBAの転化率が増大しなくなると共にNV
Aへの選択率も低下するので好ましくない。温度は19
0°C〜250℃、好ましくは200℃〜240℃が適
当である。温度が低すぎる場合には、EBAの融点が高
いためug/℃)、液相を保ちにくくなること及び分解
速度が遅くなることから好ましくない。一方温度が高す
ぎる場合にはNVAへの選択率が低下するので好ましく
ない。That is, the operating pressure is 20 to 400 mH! i', preferably 40 to 200wH, 9 is suitable. If the pressure is too low, the conversion rate of EBA will be low.9 On the other hand, if the pressure is too high,
In this case, the conversion rate of EBA does not increase and the NV
This is not preferable because the selectivity to A also decreases. The temperature is 19
A temperature of 0°C to 250°C, preferably 200°C to 240°C is suitable. If the temperature is too low, it is not preferable because the melting point of EBA is high (ug/°C), it becomes difficult to maintain a liquid phase, and the decomposition rate becomes slow. On the other hand, if the temperature is too high, the selectivity to NVA will decrease, which is not preferable.
・ しかし、上記の適切な操作圧力及び温度範囲で加熱
してEBAの分解を実施したのみでは、発生した蒸気が
冷却された再び反応液に還流するためにNVAへの選択
率は上昇しない。そこで本発明では液相から発生した蒸
気を液相に還流させずに補集するようにしたのである。- However, simply decomposing EBA by heating in the above-mentioned appropriate operating pressure and temperature range does not increase the selectivity to NVA because the generated vapor is cooled and refluxed back to the reaction solution. Therefore, in the present invention, the vapor generated from the liquid phase is collected without being refluxed to the liquid phase.
また伝熱面に接する液相に対する蒸発表面積の割合が小
さくても液相に存在しているNVAが2量化するなどの
2次的な反応に消費されるために高い選択性を保持でき
ない。Furthermore, even if the ratio of the evaporation surface area to the liquid phase in contact with the heat transfer surface is small, high selectivity cannot be maintained because NVA present in the liquid phase is consumed in secondary reactions such as dimerization.
すなわち通常の攪拌機付き容器に対して空間容積の約5
0%に相当する部分に原料のEBAを仕込んで、加熱し
て分解と蒸発を行っても良い結果は得られず、伝熱面に
接する液相に対する蒸発面積は0.4 crIL”/c
♂以上とする必要があることが判明した。That is, about 5% of the space volume compared to a normal container with a stirrer.
Even if the raw material EBA is charged in the portion corresponding to 0% and heated to decompose and evaporate, no good results are obtained, and the evaporation area for the liquid phase in contact with the heat transfer surface is 0.4 crIL"/c
It turned out that it was necessary to make it more than ♂.
前述の通常の装置でもEBAの仕込み容積を減らして反
応を行えば蒸発表面積の比率が大となシ選択率は上昇す
るが、実際的ではない。従って加熱伝熱面上に薄い液膜
を形成せしめて、液相に加わった熱がEBAの分解と生
成した液相混合物の蒸発に直ちに利用されながら分解と
蒸発が行われる装置が特に好ましい。Even in the above-mentioned conventional apparatus, if the reaction is carried out by reducing the charged volume of EBA, the selectivity will increase when the ratio of the evaporation surface area is large, but this is not practical. Therefore, it is particularly preferable to use an apparatus in which decomposition and evaporation are carried out by forming a thin liquid film on the heating heat transfer surface and using the heat added to the liquid phase to immediately decompose the EBA and evaporate the produced liquid phase mixture.
このような装置の1例を第1図に示す。この装置では、
反応容器の本体(C)はガラス円筒であり、上部の回転
クヤ7トによって回転し得るようになっている。本体(
C)の下部には中空のシャフト(D)が設けられ、この
シャフトは真空シールを介して水槽(F)中に浸された
冷却フラスコ(E)に接続されている。冷却フラスコに
は内部を減圧にするための排気ラインが接続されている
。本体(C)はサイトグラス付きのオイルバス(B)で
加熱できるようになっておシ、オイルバスのオイルはレ
ベルラインを通してその液面を上下の位置に設定できる
ようにしである。この装置の本体(C)内にEBAを仕
込んだ後、排気ラインによって所定の圧力とした後、ま
ず回転シャフトを低速で回転させる。所定温度に予熱し
たオイルをレベルラインから本体(C)の上面がかくれ
るまで流入する。オイルバス(B)の温度はヒータを用
いて加熱して一定に保つ。An example of such a device is shown in FIG. With this device,
The main body (C) of the reaction vessel is a glass cylinder, which can be rotated by a rotating shaft 7 at the top. Main body (
The lower part of C) is provided with a hollow shaft (D), which is connected via a vacuum seal to a cooling flask (E) immersed in a water bath (F). An exhaust line is connected to the cooling flask to reduce the pressure inside. The main body (C) can be heated in an oil bath (B) equipped with a sight glass, and the oil level in the oil bath can be set at the upper or lower position through a level line. After EBA is charged into the main body (C) of this device, a predetermined pressure is established through an exhaust line, and the rotating shaft is first rotated at a low speed. Oil preheated to a predetermined temperature flows from the level line until the top surface of the main body (C) is covered. The temperature of the oil bath (B) is kept constant by heating using a heater.
EBAが融解し終ると同時に回転シャフトの回転数を例
えば2000rpmiで上げて、本体内壁にEBAの液
膜を形成させ、排気圧力を所定の圧力に保ちながら分解
と蒸発を行う。発生する蒸気は中空シャフト(D)を通
って冷却フラスコに導びかれ、そこで回収される。この
ようにして回収された未反応EBAを含むNVAとAc
NH2との混合物から、本発明者等が先に提案してい
る特願昭59−188098号の方法によって効率よで
純品のNVAを取得することができる。At the same time as the EBA finishes melting, the rotational speed of the rotary shaft is increased to, for example, 2000 rpm to form a liquid film of EBA on the inner wall of the main body, and decomposition and evaporation are performed while maintaining the exhaust pressure at a predetermined pressure. The vapor generated is conducted through a hollow shaft (D) into a cooling flask where it is collected. NVA containing unreacted EBA and Ac
Pure NVA can be efficiently obtained from a mixture with NH2 by the method disclosed in Japanese Patent Application No. 59-188098, which was previously proposed by the present inventors.
本発明の方法で、原料として使用するEBAは純品に限
られず、EBAの合成原料でおるAc NH2の共存す
るものでもよく、また水分が含まれているものでもよい
。In the method of the present invention, the EBA used as a raw material is not limited to a pure product, and may be one in which Ac NH2, which is a raw material for EBA synthesis, coexists, or one containing water.
本発明の方法を実施する反δ器の材質は、鉄、ステンレ
ス、アルミニウム、ガラス等が用いられるが、銅はNV
Aへの選択率を低下させるので好ま、)、、
L <な“・
〔実施例〕
第1図に示す装置を使用して、内径10crIL×長さ
12cIrLのガラス円筒からなる本体(C)に原料を
仕込み、排気ラインを300mxH&として、回転シャ
フト(A)を低速で回転させ、所定温度のオイルをレベ
ルラインから本体(C)がかくれるまで流入した後、オ
イルの温度をヒーターによって一定に保持した。原料が
溶解すると同時に回転シャフトを200Orpm と
して本体(G)に液膜を形成させ、排気圧力を所定の値
にした。発生する蒸気は冷却フラスコ中にほぼ白い固体
となシ回収された。この白色固体を水に溶かして取出し
、一部を分取してガスクロマトグラフィ法によって定量
分析した。The material of the reactor for carrying out the method of the present invention is iron, stainless steel, aluminum, glass, etc., but copper is
It is preferable because it lowers the selectivity to A).
[Example] Using the apparatus shown in Fig. 1, raw materials are charged into the main body (C) made of a glass cylinder with an inner diameter of 10 crIL x length of 12 cIrL, an exhaust line of 300 m x H&, and a rotating shaft (A ) was rotated at low speed, and oil at a predetermined temperature was flowed in from the level line until the main body (C) was covered.The temperature of the oil was kept constant by a heater.At the same time as the raw material was melted, the rotating shaft was set to 200 rpm and the main body (C) was rotated at a low speed. G) was allowed to form a liquid film, and the exhaust pressure was adjusted to a predetermined value.The generated steam was recovered as an almost white solid in the cooling flask.This white solid was dissolved in water and taken out, and a portion was separated. The sample was then quantitatively analyzed by gas chromatography.
表1に示すように4種類の反応条件を選定して分解を行
ったが、反応後容器本体内には殆ど残留物は認められな
かった。得られた結果を表1に示す。As shown in Table 1, four types of reaction conditions were selected for decomposition, but almost no residue was observed in the container body after the reaction. The results obtained are shown in Table 1.
表 1 (11(C)内温度は操作開始5分後の温度である。Table 1 (11(C) Internal temperature is the temperature 5 minutes after the start of the operation.
+21 3=蒸発表面積(crrL”)、 V=液容積
(cm” )〔発明の効果〕
本発明はEBAを加熱してNVAを製造する熱分解法に
おいて、20〜400mH,!i’の圧力下で、190
〜250℃の温度で加熱し、発生した蒸気を液相に還流
させることなく、かつ伝熱面に接する液相に対する蒸発
表面の割合を0.4 cIrL”/arr”以上とした
ものであシ、分解で生成したNVAが2次的反応を起す
ことがなく、従って高い選択率でNVAを得ることがで
きる。+21 3=evaporation surface area (crrL”), V=liquid volume (cm”) [Effects of the invention] The present invention provides a thermal decomposition method for producing NVA by heating EBA at 20 to 400 mH,! under the pressure of i', 190
It is heated at a temperature of ~250°C, without refluxing the generated vapor to the liquid phase, and the ratio of the evaporation surface to the liquid phase in contact with the heat transfer surface is 0.4 cIrL"/arr" or more. , NVA produced by decomposition does not undergo secondary reactions, and therefore NVA can be obtained with high selectivity.
第1図は本発明の熱分解法を実施する装置例の概要図で
るる。
図中符号:
A・・・回転シャフト;B・・・オイルバス;C・・・
ガラス円筒;D・・・蒸気排出用中空シャフト;(ほか
3名)
第 1 図
手続補正誉(方式)
%式%
1、事件の表示
昭;ti159年特針願第225996号2、@明の名
4F
エチリデンビスアセトアミドの熱分解法6、補正をする
者
J#汗との闘保:S許出願人
名称 (200)昭和−工株式会社
鏝が関ビル同郵便局私書箱第49号
栄光特許事務所 電話(581)−9601(代表)&
補正の対象
明#l114にの発明の詳細な説明の楠(1)明細書落
2頁6〜7行目の記載を「〔テトラヘトaン レターズ
(Tetrahedron Letters)450.
4526〜4526負(1965年)〕。」に補正する
。FIG. 1 is a schematic diagram of an example of an apparatus for carrying out the pyrolysis method of the present invention. Symbols in the diagram: A... Rotating shaft; B... Oil bath; C...
Glass cylinder; D...Hollow shaft for steam discharge; (3 others) Figure 1 Procedural amendment honor (method) % formula % 1. Indication of the incident Show; ti159 special policy application No. 225996 2, @ Ming. Name 4F Thermal decomposition method of ethylidene bisacetamide 6, Person making the amendment J# Fighting against sweat: S License Applicant name (200) Showa-Ko Co., Ltd. Kazugaseki Building Post Office Box 49 Eikou Patent Office Phone: (581)-9601 (main) &
Kusunoki (1) Detailed Description of the Invention in Object of Amendment #l114 (1) The description on page 2, lines 6-7 of the specification has been changed to "[Tetrahedron Letters] 450.
4526-4526 negative (1965)]. ”.
Claims (1)
トアミドを製造する熱分解法において、伝熱面に接する
液相のエチリデンビスアセトアミドに対する蒸発表面の
割合を0.4cm^2/cm^3以上として、20〜4
00mmHgの圧力、190〜250℃の温度で加熱し
、液相から発生した蒸気を液相に還流させることなく冷
却して補集することを特徴とするエチリデンビスアセト
アミドの熱分解法。In the thermal decomposition method for producing N-vinylacetamide by heating ethylidene bisacetamide, the ratio of the evaporation surface to the ethylidene bisacetamide in the liquid phase in contact with the heat transfer surface is set to 0.4 cm^2/cm^3 or more, and the ratio is 20 to 20. 4
A method for thermally decomposing ethylidene bisacetamide, which comprises heating at a pressure of 00 mmHg and a temperature of 190 to 250°C, and cooling and collecting the vapor generated from the liquid phase without refluxing it into the liquid phase.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP22599384A JPS61106546A (en) | 1984-10-29 | 1984-10-29 | Pyrolysis of ethylidenebisamide |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP22599384A JPS61106546A (en) | 1984-10-29 | 1984-10-29 | Pyrolysis of ethylidenebisamide |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS61106546A true JPS61106546A (en) | 1986-05-24 |
Family
ID=16838108
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP22599384A Pending JPS61106546A (en) | 1984-10-29 | 1984-10-29 | Pyrolysis of ethylidenebisamide |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS61106546A (en) |
Cited By (6)
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WO2021132363A1 (en) | 2019-12-26 | 2021-07-01 | 昭和電工株式会社 | Method for manufacturing highly polymerizable n-vinyl carboxylic acid amide monomer |
WO2021132365A1 (en) | 2019-12-26 | 2021-07-01 | 昭和電工株式会社 | Method for producing highly polymerizable n-vinyl carboxylic acid amide monomer |
WO2021132367A1 (en) | 2019-12-26 | 2021-07-01 | 昭和電工株式会社 | Method for producing highly polymerizable n-vinylcarboxamide monomer |
WO2021132366A1 (en) | 2019-12-26 | 2021-07-01 | 昭和電工株式会社 | Method for producing highly polymerizable n-vinylcarboxylic acid amide monomer |
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-
1984
- 1984-10-29 JP JP22599384A patent/JPS61106546A/en active Pending
Cited By (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2020110614A1 (en) * | 2018-11-29 | 2020-06-04 | 昭和電工株式会社 | Method for producing n-vinylcarboxylic amide |
CN113166041A (en) * | 2018-11-29 | 2021-07-23 | 昭和电工株式会社 | Process for producing N-vinylcarboxylic acid amide |
JPWO2020110614A1 (en) * | 2018-11-29 | 2021-10-14 | 昭和電工株式会社 | Method for producing N-vinylcarboxylic acid amide |
CN113166041B (en) * | 2018-11-29 | 2023-03-17 | 昭和电工株式会社 | Process for producing N-vinylcarboxylic acid amide |
WO2021132363A1 (en) | 2019-12-26 | 2021-07-01 | 昭和電工株式会社 | Method for manufacturing highly polymerizable n-vinyl carboxylic acid amide monomer |
WO2021132365A1 (en) | 2019-12-26 | 2021-07-01 | 昭和電工株式会社 | Method for producing highly polymerizable n-vinyl carboxylic acid amide monomer |
WO2021132367A1 (en) | 2019-12-26 | 2021-07-01 | 昭和電工株式会社 | Method for producing highly polymerizable n-vinylcarboxamide monomer |
WO2021132366A1 (en) | 2019-12-26 | 2021-07-01 | 昭和電工株式会社 | Method for producing highly polymerizable n-vinylcarboxylic acid amide monomer |
WO2021132364A1 (en) | 2019-12-26 | 2021-07-01 | 昭和電工株式会社 | Method for producing highly polymerizable n-vinylcarboxamide monomer |
US11718579B2 (en) | 2019-12-26 | 2023-08-08 | Showa Denko K.K. | Method for producing highly polymerizable N-vinyl carboxylic acid amide monomer |
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