JPH0124783B2 - - Google Patents
Info
- Publication number
- JPH0124783B2 JPH0124783B2 JP56051216A JP5121681A JPH0124783B2 JP H0124783 B2 JPH0124783 B2 JP H0124783B2 JP 56051216 A JP56051216 A JP 56051216A JP 5121681 A JP5121681 A JP 5121681A JP H0124783 B2 JPH0124783 B2 JP H0124783B2
- Authority
- JP
- Japan
- Prior art keywords
- reaction
- stage
- isocyanate
- phosgene
- amine
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 238000006243 chemical reaction Methods 0.000 claims description 127
- 239000012948 isocyanate Substances 0.000 claims description 60
- 150000002513 isocyanates Chemical class 0.000 claims description 60
- YGYAWVDWMABLBF-UHFFFAOYSA-N Phosgene Chemical compound ClC(Cl)=O YGYAWVDWMABLBF-UHFFFAOYSA-N 0.000 claims description 53
- 238000000034 method Methods 0.000 claims description 45
- CKDWPUIZGOQOOM-UHFFFAOYSA-N Carbamyl chloride Chemical compound NC(Cl)=O CKDWPUIZGOQOOM-UHFFFAOYSA-N 0.000 claims description 34
- 150000001412 amines Chemical class 0.000 claims description 33
- RFFLAFLAYFXFSW-UHFFFAOYSA-N 1,2-dichlorobenzene Chemical group ClC1=CC=CC=C1Cl RFFLAFLAYFXFSW-UHFFFAOYSA-N 0.000 claims description 22
- -1 amine hydrochloride Chemical class 0.000 claims description 20
- 239000006227 byproduct Substances 0.000 claims description 12
- 238000000354 decomposition reaction Methods 0.000 claims description 12
- VOZKAJLKRJDJLL-UHFFFAOYSA-N tolylenediamine group Chemical group CC1=C(C=C(C=C1)N)N VOZKAJLKRJDJLL-UHFFFAOYSA-N 0.000 claims description 11
- UPMLOUAZCHDJJD-UHFFFAOYSA-N 4,4'-Diphenylmethane Diisocyanate Chemical compound C1=CC(N=C=O)=CC=C1CC1=CC=C(N=C=O)C=C1 UPMLOUAZCHDJJD-UHFFFAOYSA-N 0.000 claims description 8
- 239000012295 chemical reaction liquid Substances 0.000 claims description 7
- 239000003960 organic solvent Substances 0.000 claims description 4
- 239000011541 reaction mixture Substances 0.000 claims description 4
- 150000003141 primary amines Chemical class 0.000 claims description 3
- 238000010924 continuous production Methods 0.000 claims description 2
- 239000013067 intermediate product Substances 0.000 claims description 2
- DVKJHBMWWAPEIU-UHFFFAOYSA-N toluene 2,4-diisocyanate Chemical group CC1=CC=C(N=C=O)C=C1N=C=O DVKJHBMWWAPEIU-UHFFFAOYSA-N 0.000 claims description 2
- HLPKYOCVWVMBMR-UHFFFAOYSA-N azane benzylbenzene Chemical compound N.N.C=1C=CC=CC=1CC1=CC=CC=C1 HLPKYOCVWVMBMR-UHFFFAOYSA-N 0.000 claims 1
- 239000007789 gas Substances 0.000 description 11
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 10
- 229910000041 hydrogen chloride Inorganic materials 0.000 description 10
- IXCSERBJSXMMFS-UHFFFAOYSA-N hydrogen chloride Substances Cl.Cl IXCSERBJSXMMFS-UHFFFAOYSA-N 0.000 description 10
- 239000002904 solvent Substances 0.000 description 9
- 238000004821 distillation Methods 0.000 description 8
- 239000007788 liquid Substances 0.000 description 8
- 238000004519 manufacturing process Methods 0.000 description 7
- 239000006185 dispersion Substances 0.000 description 5
- 239000000203 mixture Substances 0.000 description 5
- 238000003756 stirring Methods 0.000 description 5
- 230000007423 decrease Effects 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 239000002002 slurry Substances 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- 239000000047 product Substances 0.000 description 3
- 230000035484 reaction time Effects 0.000 description 3
- 230000001105 regulatory effect Effects 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 229910000831 Steel Inorganic materials 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 239000012442 inert solvent Substances 0.000 description 2
- 239000012071 phase Substances 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- KXDHJXZQYSOELW-UHFFFAOYSA-M Carbamate Chemical compound NC([O-])=O KXDHJXZQYSOELW-UHFFFAOYSA-M 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 1
- 125000003277 amino group Chemical group 0.000 description 1
- 125000003118 aryl group Chemical group 0.000 description 1
- 239000004202 carbamide Substances 0.000 description 1
- 125000003917 carbamoyl group Chemical group [H]N([H])C(*)=O 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000007872 degassing Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- ZZTCPWRAHWXWCH-UHFFFAOYSA-N diphenylmethanediamine Chemical compound C=1C=CC=CC=1C(N)(N)C1=CC=CC=C1 ZZTCPWRAHWXWCH-UHFFFAOYSA-N 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 125000004435 hydrogen atom Chemical class [H]* 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 229920001228 polyisocyanate Polymers 0.000 description 1
- 239000005056 polyisocyanate Substances 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 238000007086 side reaction Methods 0.000 description 1
- 239000000725 suspension Substances 0.000 description 1
Landscapes
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Description
【発明の詳細な説明】
本発明は工業的に有利なイソシアナートを連続
的に製造する方法に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an industrially advantageous method for continuously producing isocyanates.
さらに詳しくは３〜７Kg／cm2ゲージ圧の加圧
下、中間生成物のカルバミルクロライドとアミン
塩酸塩が30〜70％存在しているようにイソシアナ
ートへ分解する温度の60乃至100℃の温度を維持
しながら管状の循環回路中で第１段目の反応を行
い、しかる後にこれを120〜160℃に昇温された第
２段目の反応器に導き、反応を完結させイソシア
ナートに転換する方法に関するものであり、その
特徴とする所は比較的に短かい時間の反応で、高
い反応濃度においても好収率でイソシアナートが
得られ、小容量のホスゲン化反応器で大量生産を
行なうことができ、工業的に有利に実施できる点
にある。 More specifically, under pressure of 3 to 7 Kg/cm 2 gauge pressure, at a temperature of 60 to 100°C, the temperature at which the intermediate products carbamyl chloride and amine hydrochloride decompose into isocyanate in a proportion of 30 to 70%. The first stage reaction is carried out in a tubular circulation circuit while maintaining the temperature, and then it is led to the second stage reactor where the temperature is raised to 120-160°C, where the reaction is completed and converted to isocyanate. This method is characterized by a relatively short reaction time, the ability to obtain isocyanates in good yields even at high reaction concentrations, and the ability to perform mass production using a small-capacity phosgenation reactor. This means that it can be carried out industrially advantageously.
最近有機イソシアナート類特にトリレンジイソ
シアナート（以下TDIと称す）およびジフエニル
メタンジイソシアナート（以下MDIと称す）な
どの芳香族ポリイソシアナート類は相当する一級
アミンをＯ−ジクロルベンゼンのような不活性の
有機溶媒中でホスゲン化することにより大量に製
造されている。このように大量に製造されている
製品はわずかな経済上の改良でさえ工業的に実施
された場合は大きな利益をもたらし工業的にはき
わめて重要になる。 Recently, organic isocyanates, especially aromatic polyisocyanates such as tolylene diisocyanate (hereinafter referred to as TDI) and diphenylmethane diisocyanate (hereinafter referred to as MDI), It is produced in large quantities by phosgenation in an inert organic solvent. Products manufactured in such large quantities are of great importance industrially, as even small economic improvements can yield great benefits if implemented industrially.
この化合物を第１級アミン（以下アミンと称
す）またはその塩とホスゲンとの反応によつて製
造することは、公知であり、この方法について数
多くの文献が提案されている。 It is known to produce this compound by reacting a primary amine (hereinafter referred to as amine) or a salt thereof with phosgene, and numerous documents have proposed this method.
しかしながらこれらの方法の多くは収率が90％
以下であるか、または収率が高い場合においても
反応の濃度が著しく低いか、または反応時間が著
しく長いなどの欠点があり今だ工業的に実施する
場合満足さるべきものではなかつた。 However, many of these methods have a yield of 90%.
However, even when the yield is low or the yield is high, the concentration of the reaction is extremely low or the reaction time is extremely long, which are disadvantageous and have not yet been satisfactory when carried out industrially.
今までの方法の多くは例えばTDIの場合は次式
に示すように30乃至40℃以下の低温で液状ホスゲ
ンまたはホスゲンの不活性溶媒溶液と、アミンの
不活性溶媒溶液とを反応させてアミノ基を一部カ
ルバミルクロライドまたはアミン塩酸塩の形にか
え、つぎに100〜180℃に加熱してカルバミルクロ
ライドをイソシアナートにかえるとともにホスゲ
ンを吹き込み反応の過程で副生する未反応アミン
塩酸塩をイソシアナートにかえる方式が一般にと
られている。 Most of the conventional methods, for example in the case of TDI, involve reacting liquid phosgene or an inert solvent solution of phosgene with an inert solvent solution of amine at a low temperature of 30 to 40°C or less, as shown in the following formula, to form an amino group. A part of the amine hydrochloride is converted into carbamyl chloride or amine hydrochloride, and then the carbamyl chloride is converted to isocyanate by heating at 100 to 180°C, and phosgene is blown in to remove unreacted amine hydrochloride, which is produced as a by-product during the reaction process. Generally, the method is to switch to isocyanate.
この方式について槽式、塔式または循環ライン
などの反応型式が取られ、または、アミンとホス
ゲンとのモル比の変更、触媒の使用または高圧下
でホスゲン化する方式が種々提案されている。 Various reaction methods have been proposed for this method, such as a tank type, a column type, or a circulation line, and various methods have been proposed, including changing the molar ratio of amine and phosgene, using a catalyst, or phosgenation under high pressure.
この反応において式(1)のアミンとホスゲンとの
反応は低温でも非常に早く、反応の過程でアミン
塩酸塩を副生する。このアミン塩酸塩とホスゲン
との反応によるカルバミルクロライドの生成（式
２）は割合におそく低温ではほとんど進行しない
のでつぎに100〜180℃に加熱してホスゲンを吹き
込みながら未反応のアミン塩酸塩をイソシアナー
トに変えるとともに式(3)のカルバミルクロライド
の分解を行ないイソシアナートに変える方法がと
られている。 In this reaction, the reaction between the amine of formula (1) and phosgene is very rapid even at low temperatures, and amine hydrochloride is produced as a by-product during the reaction process. The formation of carbamyl chloride (Formula 2) by the reaction between this amine hydrochloride and phosgene is relatively slow and hardly progresses at low temperatures. In addition to converting the carbamyl chloride into isocyanate, a method has been adopted in which carbamyl chloride of formula (3) is decomposed to convert it into isocyanate.
この場合カルバミルクロライドは加熱により割
合に簡単に分解反応を開始し120℃付近以上では
ほぼ完全にイソシアナートに分解されるが未反応
のアミン塩酸塩のホスゲン化速度は比較的遅い。
この反応を早くするため反応温度を高くすると分
解により生じたイソシアナートとアミン塩酸塩と
の反応が起き好ましくない尿素化合物を生じ、こ
れがさらにホスゲン化を受け、またはイソシアナ
ートと重縮合し、複雑な種々の副反応を起こし、
タール状物質の副生成をもたらし収率低下の大き
な原因と考えられた。 In this case, carbamyl chloride starts a decomposition reaction relatively easily when heated, and is almost completely decomposed into isocyanate at temperatures above about 120°C, but the rate of phosgenation of unreacted amine hydrochloride is relatively slow.
When the reaction temperature is raised to speed up this reaction, the isocyanate produced by the decomposition reacts with the amine hydrochloride to produce an undesirable urea compound, which is further phosgenated or polycondensed with the isocyanate, resulting in complex Causes various side reactions,
This was thought to be a major cause of the decrease in yield due to the by-product of tar-like substances.
従つてこのアミン塩酸塩のホスゲン化をできる
だけ低温で行ない収率よくイソシアナートを得よ
うと色々改良法が提案されている。例えば、特公
昭39−14664号は第１段において、まず室温付近
で式(1)の反応を行ない、第２段目では60〜80℃で
４乃至８時間を要して式(2)の反応により完全にカ
ルバミルクロライドに転換したのち、第３段目に
おいて式(3)のカルバミルクロライドをイソシアナ
ートに分解し収率よくイソシアナートを得ようと
いう方法が記載されている。しかしこの方法は反
応時間が非常に長くなり、また反応の濃度もあま
り高くできないので大容量の反応器を必要とし、
TDIまたはMDIなど大量生産する場合において
工業的に満足すべきものではない。これに対し比
較的小容量の反応器を用い大量生産が可能な方法
として、例えば特公昭35−10774号、特公昭40−
17381号、および特公昭51−6126号が挙げられる。
特公昭35−10774号はカルバミルクロライドが分
解する以上の温度でイソシアナートの溶液を閉塞
されたループ（closed loop）のまわりを再循環
させそれにアミンを装入して一気に反応を行なつ
たのち、副生成物の塩化水素および過剰のホスゲ
ンをある箇所で低圧において除去し、そうしてイ
ソシアナート溶液の一部を回収する方法が記載さ
れている。この方法は高レイノルズ数の渦流状態
下にアミンとホスゲンとを短時間に接触させ対応
するアミンから一気にイソシアナートに変換する
ことができ、５〜10％程度の比較的反応濃度の低
い場合はかなり高収率で有機イソシアナート類を
連続的に製造でき、かなりの成果が得られてい
る。しかしながらこの方法では反応液の濃度を16
％と高くするとアミンとホスゲンとの反応の外に
アミンとイソシアナートの好ましくない反応も増
加し、不揮発性のタール状物質生成の増大を招
き、その結果収率の低下をきたし、反応液の濃度
を高くし、工業的に効率よく、高品質のイソシア
ナートを製造できない欠点があつた。また特公昭
40−17381号は、アミンと過剰量のホスゲンとを
接触反応させ対応するイソシアナートと中間体を
形成し、前段（100〜110℃）の反応が完了しない
内に、（数秒から30分）他の反応系（150〜170℃）
に反応物質を通し、ホスゲンと塩化水素との混合
物を塩化水素の濃度が第１反応系に導入したホス
ゲンとアミンとの完全反応により形成されるもの
より大であるようにして接触させる方法である。
この方法は特に第１段の滞留時間と第２段でホス
ゲンと塩化水素の割合を一定割合に調節すること
がイソシアナートへの収率を高くするための重要
なポイントであることが記載されている。しかし
工業的実施においてそのコントロールが煩雑であ
りまた反応濃度も高くできないなどまだ十分満足
さるべき方法とはいえない。また特公昭51−6126
号はホスゲンおよびアミンを40〜120℃の温度お
よび10〜50Kg／cm2のゲージ圧で反応させ次いでそ
の結果生じた反応混合物のカルバミルクロライド
を120〜180℃の温度および少なくとも15Kg／cm2の
ゲージ圧で加熱することにより有機イソシアナー
トを連続的に製造する方法であり、その実施態様
には、ホスゲン−アミン反応が気体分離器を含む
管状回路内で反応混合物を循環させながら行わ
れ、次で完結したカルバミルクロライドの加熱の
工程が蒸留塔内で加圧下に行われ、ここでカルバ
ミルクロライドのイソシアナートへの分解と塩化
水素並びにホスゲンの蒸留の両者が行なわれ、塔
の基部から取出されるホスゲン含有イソシアナー
ト希釈混合物は、大気圧下又は僅かな加圧下で蒸
留され、イソシアナート溶液が分離される方法が
記載されている。 Therefore, various improved methods have been proposed in order to carry out the phosgenation of this amine hydrochloride at as low a temperature as possible to obtain isocyanate in good yield. For example, in Japanese Patent Publication No. 39-14664, in the first stage, the reaction of formula (1) is first carried out near room temperature, and in the second stage, the reaction of formula (2) is carried out at 60 to 80°C for 4 to 8 hours. A method is described in which, after complete conversion to carbamyl chloride by reaction, the carbamyl chloride of formula (3) is decomposed into isocyanate in the third stage to obtain isocyanate in good yield. However, this method requires a very long reaction time and requires a large-capacity reactor because the reaction concentration cannot be very high.
It is not industrially satisfactory for mass production such as TDI or MDI. On the other hand, methods that allow mass production using a relatively small-capacity reactor include, for example, Japanese Patent Publication No. 10774-1977,
No. 17381, and Special Publication No. 51-6126.
In Japanese Patent Publication No. 35-10774, a solution of isocyanate is recirculated around a closed loop at a temperature higher than that at which carbamyl chloride decomposes, and an amine is charged into the loop to carry out the reaction all at once. , a process is described in which by-product hydrogen chloride and excess phosgene are removed at low pressure at a point, and a portion of the isocyanate solution is then recovered. In this method, the amine and phosgene are brought into contact with each other in a short period of time under a vortex flow condition with a high Reynolds number, and the corresponding amine can be converted into isocyanate at once. Organic isocyanates can be produced continuously with high yields, and considerable results have been obtained. However, in this method, the concentration of the reaction solution is reduced to 16
%, in addition to the reaction between the amine and phosgene, undesirable reactions between the amine and isocyanate also increase, leading to an increase in the formation of non-volatile tar-like substances, resulting in a decrease in yield and a decrease in the concentration of the reaction solution. The drawback was that it was difficult to produce high-quality isocyanates industrially and efficiently. Also Tokko Akira
No. 40-17381 involves a contact reaction between an amine and an excess amount of phosgene to form a corresponding isocyanate and an intermediate, and the reaction is carried out (from a few seconds to 30 minutes) before the previous reaction (100 to 110°C) is completed. reaction system (150-170℃)
a mixture of phosgene and hydrogen chloride is brought into contact with the mixture of phosgene and hydrogen chloride in such a way that the concentration of hydrogen chloride is greater than that formed by the complete reaction of the phosgene and the amine introduced into the first reaction system. .
In this method, it is described that controlling the residence time in the first stage and the ratio of phosgene and hydrogen chloride in the second stage to a constant ratio are important points for increasing the yield of isocyanate. There is. However, in industrial implementation, the control is complicated and the reaction concentration cannot be increased, so it is not yet a fully satisfactory method. Also special public service 51-6126
No. 1 reacts phosgene and amine at a temperature of 40-120°C and a gauge pressure of 10-50 Kg/cm 2 and then reacts the resulting reaction mixture carbamyl chloride at a temperature of 120-180°C and a gauge pressure of at least 15 Kg/cm 2 . A process for the continuous production of organic isocyanates by heating at gauge pressure, in which the phosgene-amine reaction is carried out with circulation of the reaction mixture in a tubular circuit containing a gas separator; The completed process of heating the carbamyl chloride is carried out under pressure in a distillation column, where both the decomposition of the carbamyl chloride to isocyanates and the distillation of hydrogen chloride and phosgene take place, which are removed from the base of the column. A method is described in which the diluted phosgene-containing isocyanate mixture is distilled under atmospheric or slightly elevated pressure and the isocyanate solution is separated.
確かに10乃至50気圧のような高圧下に反応させ
れば反応液中のホスゲン溶解度は著しく増大し、
カルバミルクロライドへの生成反応速度も早くな
り、かつ高い反応濃度でも好収率でイソシアナー
トが得られることは従来から知られていた。 It is true that if the reaction is carried out under high pressure such as 10 to 50 atmospheres, the solubility of phosgene in the reaction solution will increase significantly.
It has been known for a long time that the production reaction rate to carbamyl chloride is faster and that isocyanate can be obtained in good yield even at high reaction concentrations.
また第２段階のカルバミルクロライドの分解を
高圧で実施すれば未反応のホスゲンの凝縮が容易
になり塩化水素を分離する課題が容易になる効果
も確かにある。しかしながらこのような高圧下で
大過剰のホスゲンを含有する反応液を大量に取り
扱うのは工業的に実施する場合非常に危険であ
り、安全性の面から特別の考慮が必要になる。 Furthermore, if the decomposition of carbamyl chloride in the second stage is carried out at high pressure, unreacted phosgene can be easily condensed and the problem of separating hydrogen chloride can certainly be facilitated. However, handling a large amount of a reaction solution containing a large excess of phosgene under such high pressure is extremely dangerous when carried out industrially, and special consideration is required from the viewpoint of safety.
またカルバミルクロライドは溶剤に難溶であ
り、このような高い濃度のスラリー液を、高圧下
で管状回路内に循環することは、金属材質に対す
る腐食度が著しく増大し、通常用いられているス
テンレス鋼では使用不可能となり、高価な材質が
必要になるなど設備費が著しく増大する。 In addition, carbamyl chloride is poorly soluble in solvents, and circulating such a highly concentrated slurry liquid in a tubular circuit under high pressure will significantly increase the degree of corrosion to metal materials. Steel cannot be used, and expensive materials are required, resulting in a significant increase in equipment costs.
さらに、反応の濃度を高くすれば、カルバミル
クロライドのスラリー状溶液は粘度が著しく増大
し、管状回路の閉塞を引き起し、反応液の循環が
困難になる。また、この方法のように加圧一段法
では第１段階での反応で、反応の過程で副生する
アミン塩酸塩のカルバミルクロライドへの反応を
完結しておかないと第２段階での蒸留塔での分解
反応においてアミン塩酸塩が塔の閉塞起こしまた
イソシアナートの収率低下の原因となるので、第
１段の反応を完結するに十分な長い滞留時間が必
要である。 Furthermore, if the concentration of the reaction is increased, the viscosity of the carbamyl chloride slurry solution increases significantly, causing blockage of the tubular circuit and making it difficult to circulate the reaction solution. In addition, in a pressurized one-stage method like this method, if the reaction of amine hydrochloride, which is a by-product in the reaction process, to carbamyl chloride is not completed in the first stage, distillation will occur in the second stage. During the decomposition reaction in the column, amine hydrochloride causes blockage of the column and decreases the yield of isocyanate, so a residence time long enough to complete the first stage reaction is required.
本発明者等は、これらの欠点を改善し、小容量
のホスゲン化反応器で大量にイソシアナートを生
産する場合、高い反応濃度でも操作性よく安全に
操業でき、しかも好収率でイソシアナートが得ら
れないか鋭意検討したところ、従来の閉塞された
ループ循環ライン中で臨界条件の温度および圧力
下、ホスゲン−アミンの反応を行なうことにより
目的を達成することができた。 The present inventors have improved these shortcomings and have achieved a system that allows safe operation with good operability even at high reaction concentrations when producing isocyanates in large quantities using a small-capacity phosgenation reactor, and that isocyanates can be produced in good yields. After intensive investigation, the objective was achieved by carrying out the phosgene-amine reaction under critical temperature and pressure conditions in a conventional closed loop circulation line.
すなわち本発明は、不活性有機溶媒存在下大過
剰のホスゲンとアミンとを反応させて対応するイ
ソシアナートを連続的に製造する方法において
(1) ３〜７Kg／cm2ゲージ圧の加圧下で中間生成物
のカルバミルクロライドが30〜70％分解する温
度の60乃至100℃を維持しながら管状循環回路
中でアミンおよび反応の過程で副生するアミン
塩酸塩のホスゲン化を行ない、
(2) 次にこの反応混合液を120乃至160℃の温度お
よび３〜７Kg／cm2ゲージ圧の圧力に維持された
第２段目の反応器に移し、ここで未反応のアミ
ン塩酸塩のホスゲン化とカルバミルクロライド
の分解とを完結させることを特徴とする連続加
圧２段階法による有機イソシアナートの製造方
法である。 That is, the present invention provides a method for continuously producing a corresponding isocyanate by reacting a large excess of phosgene with an amine in the presence of an inert organic solvent. Phosgenation of the amine and amine hydrochloride produced as a by-product during the reaction process is carried out in a tubular circulation circuit while maintaining a temperature of 60 to 100°C at which 30 to 70% of the product carbamyl chloride decomposes. The reaction mixture was then transferred to a second stage reactor maintained at a temperature of 120-160°C and a pressure of 3-7 Kg/ cm2 gauge, where the phosgenation and carbamate of unreacted amine hydrochloride were carried out. This is a method for producing organic isocyanate using a two-step continuous pressurization process characterized by completing the decomposition of mylkloride.
すなわち本発明の目的とする所は、第１段の反
応において管状循環回路中、臨界条件の温度およ
び加圧下で反応を行なうことにより、ホスゲンの
溶解度の増大および反応液の循環によるアミン当
量に対するホスゲンのモル比を著しく増大させる
ことによりホスゲンとアミンとの反応の頻度を増
大させた早い反応速度によりタール状副生成物を
抑制し、またそれにより生成するカルバミルクロ
ライドが30〜70％分解するような温度を維持しな
がら反応を行ない、逆にイソシアナートの濃度を
反応終了後の実際の濃度より低くおさえてアミン
とイソシアナートとの反応の機会を小さくするこ
とによつて、高い反応濃度においても、好収率で
イソシアナートが得られるとともに反応液中のカ
ルバミルクロライドも比較的低い濃度におさえら
れて反応液の粘度も低くなり循環回路も操作性よ
く行うことができる有機イソシアナートの連続的
製造方法である。 That is, the object of the present invention is to increase the solubility of phosgene and increase the amount of phosgene relative to the amine equivalent by circulating the reaction solution by carrying out the reaction in a tubular circulation circuit under critical conditions of temperature and pressure in the first stage reaction. The frequency of the reaction between phosgene and amine was increased by significantly increasing the molar ratio of By carrying out the reaction while maintaining a suitable temperature and conversely, by keeping the isocyanate concentration lower than the actual concentration after the reaction is completed and reducing the chance of reaction between the amine and isocyanate, even at high reaction concentrations. , isocyanate can be obtained in a good yield, and the concentration of carbamyl chloride in the reaction solution is kept to a relatively low concentration, the viscosity of the reaction solution is also low, and the circulation circuit can be easily operated. This is the manufacturing method.
図−１は、各圧力における温度と、反応液相
（溶媒Ｏ−ジクロルベンゼン中でTDI換算濃度20
重量％）中のホスゲン溶解度の関係を示し、図−
２は圧力５Kg／cm2ゲージ圧でTDIに換算した濃度
が20重量％になるようTDAをフイードしたとき
の循環回路中の各流速における温度とCOCl2／
TDAのモル比との関係を示すものである。また
図−３はTDI換算の反応濃度20％、圧力５Kg／cm2
ゲージ圧における反応温度と反応液内のTDIおよ
びカルバミルクロライドの平衡濃度との関係を示
す図であり、これらの図より、本発明方法を実施
する場合の各臨界条件が理解できる。 Figure 1 shows the temperature at each pressure and the reaction liquid phase (TDI equivalent concentration 20 in the solvent O-dichlorobenzene).
Figure - shows the relationship between phosgene solubility in
2 is the temperature and COCl 2 /
This shows the relationship with the molar ratio of TDA. In addition, Figure 3 shows a reaction concentration of 20% in terms of TDI and a pressure of 5Kg/cm 2
FIG. 2 is a diagram showing the relationship between the reaction temperature at gauge pressure and the equilibrium concentration of TDI and carbamyl chloride in the reaction solution, and from these diagrams, each critical condition when carrying out the method of the present invention can be understood.
図−１から温度が60〜100℃の範囲では、５
Kg／cm2ゲージ圧程度のわずかな加圧でホスゲン溶
解度は著しく増大し、また図−２よりホスゲンを
多量溶解した反応液を循環することにより槽形反
応機には見られないようなCOCl2／アミンのモル
比を著しく増大することができることがわかる。
また図−３よりわかるように反応温度を60〜100
℃の範囲に維持することによりカルバミルクロラ
イドからTDIへの分解平衡は、瞬時に副生する若
干のアミン塩酸塩が含まれるものの30〜70％に保
つことができて加圧条件下での50℃以下の低温で
実施する場合のように高濃度カルバモイルクロラ
イドによる反応液の粘度が著しく高くなることは
なく、循環が容易である。また100℃以内に維持
してカルバミルクロライドの分解率を30％以上に
抑えることにより加圧条件による高濃度反応液中
でも副生成物を抑制できる。また第１段反応に於
ては、圧力は７Kg／cm2ゲージ圧以下ではカルバミ
ルクロライドおよびイソシアナートの組成割合へ
の影響は温度の及ぼす影響ほど大きくないことが
わかり、圧力は供給アミン濃度、循環回路中の循
環量などにより適宜選定できる。 From Figure 1, when the temperature is in the range of 60 to 100℃, 5
The solubility of phosgene increases significantly with a slight pressurization of about Kg/cm 2 gauge pressure, and as shown in Figure 2, by circulating the reaction solution in which a large amount of phosgene is dissolved, COCl 2 which is not seen in a tank reactor is generated. It can be seen that the molar ratio of /amine can be significantly increased.
In addition, as shown in Figure 3, the reaction temperature was set at 60 to 100.
By maintaining the decomposition equilibrium from carbamyl chloride to TDI in the range of 30 to 70 °C, including some amine hydrochloride as an instantaneous by-product, the decomposition equilibrium can be maintained at 30 to 70% under pressurized conditions. The viscosity of the reaction solution does not increase significantly due to the high concentration of carbamoyl chloride, which is the case when the reaction is carried out at a low temperature below .degree. C., and circulation is easy. Furthermore, by maintaining the temperature within 100°C and suppressing the decomposition rate of carbamyl chloride to 30% or more, by-products can be suppressed even in a highly concentrated reaction solution under pressurized conditions. In addition, in the first stage reaction, it was found that when the pressure is below 7 kg/cm 2 gauge pressure, the effect on the composition ratio of carbamyl chloride and isocyanate is not as great as the effect of temperature; It can be appropriately selected depending on the amount of circulation in the circulation circuit.
本発明者らはこのような基礎データーを積み重
ねて、本発明方法を完成させたものであり第１段
目反応の温度および圧力を選ぶことによりカルバ
ミルクロライドおよびイソシアナートの濃度をコ
ントロールし、COCl2／アミンモル比を著しく増
大させることによつて反応液の循環操作を容易に
し、同時に循環ライン中でのイソシアナートの濃
度は最終的にイソシアナートに転換されたときの
濃度の約半分近くの濃度に維持されているのでイ
ソシアナートとアミンとの反応する機会も少なく
なり高い反応濃度においても高収率でイソシアナ
ートを得ることができるのである。 The present inventors accumulated such basic data and completed the method of the present invention. By selecting the temperature and pressure of the first stage reaction, the concentration of carbamyl chloride and isocyanate is controlled, and COCl By significantly increasing the 2 /amine molar ratio, the circulation operation of the reaction solution is facilitated, and at the same time, the concentration of isocyanate in the circulation line is approximately half of the concentration when it is finally converted to isocyanate. This reduces the chance of reaction between isocyanate and amine, making it possible to obtain isocyanate in high yield even at high reaction concentrations.
本発明方法は特公昭35−10774の改良発明であ
り本方法を実施する場合も第１段目の反応はカル
バミルクロライドとイソシアナートが共存する臨
界条件の温度および加圧下で行なう以外は、多く
の点に関して、特公昭35−10774公報（以下ベツ
ク法と称す）の記載と実質的に同様に操作される
のでそれらの詳細は省略する。また、それに記載
されている選択された種々のアミンや溶媒も同様
に使用できる。 The method of the present invention is an improved invention of Japanese Patent Publication No. 35-10774, and when carrying out this method, there are many exceptions except that the first stage reaction is carried out at a temperature and under pressure under critical conditions in which carbamyl chloride and isocyanate coexist. Regarding this point, since the operation is substantially the same as that described in Japanese Patent Publication No. 35-10774 (hereinafter referred to as the Beck method), the details thereof will be omitted. In addition, various selected amines and solvents described therein can be used as well.
本方法はイソシアナートとしてはTDI、MDI
の製造に特に適した方法であり、以下Ｏ−ジクロ
ルベンゼンを溶媒として使用するトリレンジアミ
ン（TDAと称す）またはジアミノジフエニルメ
タン（MDAと称す）からTDIまたはMDIを製造
する方法につき説明する。 This method uses TDI and MDI as isocyanates.
This method is particularly suitable for the production of TDI or MDI from tolylene diamine (TDA) or diaminodiphenylmethane (MDA) using O-dichlorobenzene as a solvent. .
本発明の方法において一段目のアミン分散部へ
新しく供給するホスゲンのアミンに対するモル比
は少なくとも50％／化学当量過剰のすなわち
NH2基当り1.5モル以上好ましくは70％過剰のホ
スゲンが存在することが必要である。閉塞された
ループ内の圧力は３Kg／cm2ゲージ圧から７Kg／cm2
ゲージ圧である。それらの圧力はループ（循環回
路）の周囲を再循環するホスゲンとカルバミルク
ロライドを含有するスラリー液をポンプで昇圧循
環することにより得られ、そして該圧力は一般に
溶媒やホスゲンとともに存在する副生物の塩化水
素（オフガス）の排出口で簡単に調節される。第
１段では比較的低温で、しかも加圧下で操作され
るため、ホスゲンはほとんど再循環され実際のア
ミン当量に対するホスゲンモル比は実質的には上
記モル比よりかなり大きい値になる。 In the method of the present invention, the molar ratio of phosgene to the amine freshly supplied to the first amine dispersion section is at least 50%/chemical equivalent excess, i.e.
It is necessary that there is an excess of 1.5 moles or more, preferably 70%, of phosgene per NH 2 group. The pressure inside the closed loop is 3Kg/cm 2 gauge pressure to 7Kg/cm 2
Gauge pressure. These pressures are obtained by pumping a slurry liquid containing phosgene and carbamyl chloride that is recirculated around the loop, and are generally due to the solvent and by-products present with the phosgene. Easily regulated with a hydrogen chloride (off-gas) outlet. Since the first stage is operated at relatively low temperatures and under pressure, most of the phosgene is recycled and the actual molar ratio of phosgene to amine equivalents is substantially greater than the above molar ratio.
本発明方法では一段目アミン分散部でのホスゲ
ン化反応の濃度は通常のベツク法よりもかなり高
めでもイソシアナート収率の低下はなく、実施で
きるのが特徴であり、たとえばアミン濃度は50％
まで可能であり、また反応終了時のイソシアナー
トの濃度として30％まで可能であるが通常はイソ
シアナートの収率を考慮してアミン濃度は10〜30
％反応終了時のイソシアナートの含有濃度は10〜
25％の範囲内で実施するのが好ましい。 The method of the present invention is characterized in that it can be carried out without reducing the isocyanate yield even if the concentration of the phosgenation reaction in the first stage amine dispersion section is much higher than that in the usual Beck method. For example, the amine concentration can be 50%.
It is possible to increase the isocyanate concentration to 30% at the end of the reaction, but usually the amine concentration is 10 to 30% in consideration of the isocyanate yield.
%The concentration of isocyanate at the end of the reaction is 10~
It is preferable to carry out within the range of 25%.
またアミン分散部での反応温度は60〜100℃の
範囲であるが、それらは通常のベツク法の最適温
度よりも低目であり反応液はカルバモイルクロラ
イドおよびイソシアナートを含有するスラリー液
となる。TDA、MDAを使用する場合は70〜90℃
の温度が特に好ましい温度である。圧力は３〜７
Kg／cm2ゲージ圧である。反応濃度が15重量％以上
に増大してくるとホスゲンを加圧にすることによ
り収率への効果は急上昇してくるが５気圧程度で
十分な収率が得られ７Kg／cm2ゲージ圧以上に上げ
ても収率への効果は殆んど変らない。むしろ過剰
ホスゲンの取り扱いの際の安全性において望まし
くない。 Further, the reaction temperature in the amine dispersion section is in the range of 60 to 100°C, which is lower than the optimum temperature of the usual Beck method, and the reaction liquid becomes a slurry liquid containing carbamoyl chloride and isocyanate. 70~90℃ when using TDA, MDA
is a particularly preferred temperature. pressure is 3-7
Kg/cm 2 gauge pressure. When the reaction concentration increases to 15% by weight or more, pressurizing phosgene will have a rapid effect on the yield, but a sufficient yield can be obtained at about 5 atm and 7 Kg/cm 2 gauge pressure or higher. There is almost no change in the effect on yield even if the temperature is increased. Rather, it is undesirable in terms of safety when handling excess phosgene.
ホスゲン化の第２段階での反応は槽型撹拌ある
いは槽内への循環撹拌により行ないうるが、撹拌
の必要性は第１段階ほどではない。反応液をポン
プ循環させるだけで充分である。第２段反応の温
度は120〜160℃の範囲で、圧力は７Kg／cm2ゲージ
圧以下であるが、第１段階の圧力ほど収率には影
響しない。 The reaction in the second stage of phosgenation can be carried out by tank type stirring or circulation stirring into the tank, but the need for stirring is not as great as in the first stage. It is sufficient to circulate the reaction solution with a pump. The temperature of the second stage reaction is in the range of 120-160°C and the pressure is below 7 Kg/cm 2 gauge pressure, but it does not affect the yield as much as the pressure of the first stage.
第１段階、第２段階のオフガスを合わせて過剰
ホスゲンの回収及び再循環を考慮に入れると第２
段の圧力は第１段の圧力と同等か、若干低くして
もよい。第２段の圧力上昇は新ホスゲンを送入し
てもよいし、導入されてくる第１段反応液中の溶
解ホスゲンでも充分である。 Taking into account the recovery and recirculation of excess phosgene by combining the first and second stage offgases, the second stage
The stage pressure may be equal to or slightly lower than the first stage pressure. The pressure increase in the second stage may be achieved by introducing new phosgene, or the dissolved phosgene in the first stage reaction liquid introduced is sufficient.
本方法において用いられる第１段、第２段反応
系における滞留時間は各反応系で用いられる温度
に大きく依存する。第１段において60〜100℃の
温度範囲で30分から120分の滞留時間で十分であ
り第１段で反応を完結させる必要はない。第２段
反応の滞留時間は第１段で生成される中間生成物
アミン塩酸塩のイソシアナートへ完全に転化させ
るのに充分な時間が必要である。通常120〜160℃
の温度範囲で約10分から120分の範囲で行い、こ
の際必要あらば新たにホスゲンを導入して実施さ
れる。図４は本発明方法を実施する場合のフロシ
ートであるが図４に従がつて実施例によりさらに
詳しく本発明を説明する。％は他に指示されてい
ない限り、重量％である。 The residence time in the first and second stage reaction systems used in this method largely depends on the temperature used in each reaction system. A residence time of 30 minutes to 120 minutes in the temperature range of 60 to 100°C is sufficient in the first stage, and it is not necessary to complete the reaction in the first stage. The residence time of the second stage reaction must be sufficient to completely convert the intermediate amine hydrochloride produced in the first stage to isocyanate. Normally 120~160℃
It is carried out for about 10 minutes to 120 minutes at a temperature range of 10 to 120 minutes, and if necessary, phosgene is newly introduced. FIG. 4 is a flow sheet for carrying out the method of the present invention, and the present invention will be explained in more detail by way of examples according to FIG. Percentages are by weight unless otherwise indicated.
実施例 １
図４において第１段反応系に相当する管状循環
回路はアミンフイード分散管２、ホスゲンフイー
ド管３、及び新たな溶媒フイード管（図示せず）
を回路中に有する反応管１、と、ガス分離器５、
及び循環ライン中を一定加圧下で循環させるため
のポンプ４、より構成されている。また、カルバ
ミルクロライドの分解と、アミン塩酸塩のホスゲ
ン化を同時におこなわせる第２段反応系は槽型反
応器７、と反応器内の撹拌をするための第１段反
応系と同様の管状回路１１、より構成されてい
る。そうして、ガス分離器５上部には排出される
ガスを冷却し凝縮液を循環回路内に戻し、主に
HClよりなるオフガスを圧力調節弁を通じて連続
的に系外に排出させるコンデンサー及び凝縮液溜
を経たオフガスラインが装備されている。同じ
く、第１段反応系の循環回路より連続的に導入さ
れる第２段反応槽の上部にも、第１段反応系と同
様コンデンサ、凝縮液溜付きのオフガスラインが
装備されている。Example 1 In FIG. 4, the tubular circulation circuit corresponding to the first stage reaction system includes an amine feed dispersion tube 2, a phosgene feed tube 3, and a new solvent feed tube (not shown).
a reaction tube 1 having in its circuit a gas separator 5,
and a pump 4 for circulating the air in the circulation line under constant pressure. In addition, the second stage reaction system that simultaneously performs the decomposition of carbamyl chloride and the phosgenation of amine hydrochloride is a tank type reactor 7, and a tubular type reaction system similar to the first stage reaction system for stirring the inside of the reactor. It is composed of a circuit 11. Then, the upper part of the gas separator 5 cools the discharged gas and returns the condensate to the circulation circuit.
It is equipped with an off-gas line that passes through a condenser and condensate reservoir to continuously discharge off-gas consisting of HCl out of the system through a pressure control valve. Similarly, the upper part of the second-stage reaction tank, which is continuously introduced from the circulation circuit of the first-stage reaction system, is also equipped with an off-gas line with a condenser and a condensate reservoir, as in the first-stage reaction system.
図４中の第１段反応系の管状循環回路１、は不
錆鋼材質よりなる内径１インチの反応管でありホ
スゲンと、TDA混合異性体のＯ−ジクロルベン
ゼン溶液は連続的に１、に導入される。第１段反
応系の循環ライン中にホスゲンが管３、より毎時
24.3Kg（0.246Kモル）の速度で液状ホスゲン加圧
ポンプで加熱されながら供給され、一方別の供給
口管２、より17％濃度に調節したTDAのＯ−ジ
クロルベンゼン溶液が毎時44Kg（全アミン
0.061Kモル）の速度で加圧ポンプで分散させな
がら供給された。第１段反応系の圧力はオフガス
ラインに取り付けられた圧力調整弁９、により
5.0Kg／cm2ゲージ圧に維持された。その間、約５
％のカルバモイルクロライドと約５％のTDIおよ
び過剰のホスゲンを含有するＯ−ジクロルベンゼ
ンの懸濁液が毎時8200Kgの速度で80℃に維持され
て回路内を循環されていた。 The tubular circulation circuit 1 of the first stage reaction system in FIG. 4 is a reaction tube with an inner diameter of 1 inch made of rust-free steel, and the O-dichlorobenzene solution of phosgene and TDA mixed isomer is continuously supplied at 1, will be introduced in In the circulation line of the first stage reaction system, phosgene is pumped from tube 3 every hour.
Liquid phosgene is supplied while being heated by a pressurized pump at a rate of 24.3 Kg (0.246 Kmol), while a solution of TDA in O-dichlorobenzene adjusted to a concentration of 17% is supplied from another feed port pipe 2 at a rate of 44 Kg (total total) per hour. amine
It was supplied while being dispersed by a pressure pump at a rate of 0.061 Kmol). The pressure in the first stage reaction system is controlled by a pressure regulating valve 9 attached to the off-gas line.
Maintained at 5.0 Kg/cm 2 gauge pressure. During that time, about 5
A suspension of O-dichlorobenzene containing % carbamoyl chloride, about 5% TDI and excess phosgene was being circulated through the circuit at a rate of 8200 kg per hour, maintained at 80°C.
上記アミン溶液は分散部より導入されると同時
に瞬時に拡散混合されアミンとホスゲンとの反応
が起こり得られる混合物は80℃に維持された気液
分離器（容量140）５、に循環され、そこで副
生物の塩化水素を塔頂から排気し随伴した溶媒お
よびホスゲンはコンデンサーにより凝縮液溜めよ
り管８、からループ中の反応系に返送された。反
応液の一部は導管６、より第２段反応系の槽７に
連続的に送液されるが、大部分はポンプで第１段
反応系のラインに循環され、そこに毎時59.8Kgの
新たなＯ−ジクロルベンゼンが送入され第１段反
応系の循環ラインは上記濃度に維持されていた。 The above amine solution is introduced from the dispersion section and instantaneously mixed by diffusion, and the mixture in which the reaction between amine and phosgene can occur is circulated to the gas-liquid separator (capacity 140) 5 maintained at 80°C, where Hydrogen chloride as a by-product was exhausted from the top of the column, and the accompanying solvent and phosgene were returned to the reaction system in the loop from the condensate reservoir via tube 8 using a condenser. A part of the reaction liquid is continuously sent to the tank 7 of the second stage reaction system through the conduit 6, but the majority is circulated by a pump to the line of the first stage reaction system, where 59.8 kg/hour is pumped. Fresh O-dichlorobenzene was fed into the circulation line of the first stage reaction system to maintain the above concentration.
第１段反応系のループの総ホールドアツプ（滞
留液量）は約140Kg、滞留時間は約1.4時間であつ
た。第１段反応系より管６を通して抜き出された
反応液は150℃に維持された第２段反応系の循環
ラインに送液された。第２段反応系の槽（容量
130）７、にはホスゲンが毎時６Kg（0.061Kモ
ル）の速度で管１０より供給され、内径3/4イン
チ管の循環ライン１１をポンプで循環させること
により槽内の撹拌を続けながら反応をおこなつ
た。その間オフガスライン中の圧力調整弁９によ
り槽及び循環ラインは5.0Kg／cm2ゲージ圧に維持
され、第１段反応系と同様に第２段反応系内の気
液分離器で副生する塩化水素を除去したのち随伴
する溶媒およびホスゲンはコンデンサーで凝縮さ
れ反応系に返送された。 The total hold up (amount of retained liquid) in the loop of the first stage reaction system was approximately 140 kg, and the residence time was approximately 1.4 hours. The reaction solution extracted from the first stage reaction system through tube 6 was sent to the circulation line of the second stage reaction system maintained at 150°C. Second stage reaction system tank (capacity
130) In step 7, phosgene is supplied from the tube 10 at a rate of 6 kg (0.061 Kmol) per hour, and the reaction is carried out while stirring the tank by circulating it with a pump through the circulation line 11, which is a 3/4 inch inner diameter tube. I did it. During this time, the pressure regulating valve 9 in the off-gas line maintains the tank and circulation line at 5.0 Kg/cm 2 gauge pressure, and chloride is produced as a by-product in the gas-liquid separator in the second stage reaction system as well as the first stage reaction system. After removing hydrogen, the accompanying solvent and phosgene were condensed in a condenser and returned to the reaction system.
第２段反応系の総ホールドアツプは約150Kg、
滞留時間は約1.5時間であつた。第２段反応系の
反応液の一部を抜き出されフラツシユタンク２で
減圧された後、さらに脱ガス塔で脱ガスされた生
成物のイソシアナート溶液は通常の方法により蒸
留分析したところ、10.5％のTDIおよび0.5％の不
揮発性残渣を含有していた。 The total hold up of the second stage reaction system is approximately 150Kg.
The residence time was approximately 1.5 hours. After a part of the reaction liquid in the second stage reaction system was extracted and the pressure was reduced in the flash tank 2, the isocyanate solution of the product was further degassed in the degassing tower, and the resulting isocyanate solution was analyzed by distillation using a conventional method. Contained 10.5% TDI and 0.5% non-volatile residue.
比較例 １
実施例１と同じ装置を使用して第１段反応系の
温度を140℃、圧力を0.8Kg／cm2ゲージ圧、第２段
反応系の圧力を0.8Kg／cm2ゲージ圧とした以外は
実施例１と同じ操作を行なつたところ、9.8％の
TDIおよび1.1％の不揮発性残渣を含有しており、
上記結果に比べて残渣の含有量が増大していた。Comparative Example 1 Using the same equipment as in Example 1, the temperature of the first stage reaction system was 140°C and the pressure was 0.8 Kg/cm 2 gauge pressure, and the pressure of the second stage reaction system was 0.8 Kg/cm 2 gauge pressure. When the same operation as in Example 1 was performed except for the following, 9.8% of the
Contains TDI and 1.1% non-volatile residue,
The content of residue was increased compared to the above results.
実施例 ２
実施例１と同じ装置を使用して第１段反応系に
おいて供給TDA（濃度25％のＯ−ジクロルベンゼ
ン溶液）を毎時44Kg、供給ホスゲン量毎時40.1
Kg、Ｏ−ジクロルベンゼン毎時14.1Kg、温度80
℃、循環ループ圧力5.0Kg／cm2ゲージ圧の条件下
で実施例１と同様の操作を行なつた。得られたイ
ソシアナート溶液を蒸留分析したところ24.8％の
TDIおよび1.3％の不揮発性残渣を含有していた。Example 2 Using the same equipment as in Example 1, in the first stage reaction system, TDA (O-dichlorobenzene solution with a concentration of 25%) was supplied at 44 kg/hour, and the amount of phosgene supplied was 40.1 kg/hour.
Kg, O-dichlorobenzene 14.1Kg per hour, temperature 80
The same operation as in Example 1 was carried out under the conditions of temperature and circulation loop pressure of 5.0 Kg/cm 2 gauge pressure. Distillation analysis of the obtained isocyanate solution revealed that 24.8%
Contained TDI and 1.3% non-volatile residue.
尚、第１段反応系においてホスゲン供給量を毎
時49.1Kgの速度、循環ループ圧力を10.0Kg／cm2ゲ
ージ圧とした以外は実施例２と同様の操作を行な
つた。得られたイソシアナート溶液を蒸留分析し
たところ24.5％のTDIおよび1.2％の不揮発性残渣
を含有していた。残渣の含有量は実施例２の圧力
5.0Kg／cm2ゲージ圧の場合とほぼ同等であつた。 The same operation as in Example 2 was carried out except that in the first stage reaction system, the phosgene feed rate was 49.1 kg/hour and the circulation loop pressure was 10.0 kg/cm 2 gauge pressure. The resulting isocyanate solution was analyzed by distillation and contained 24.5% TDI and 1.2% non-volatile residue. The content of the residue is the pressure of Example 2.
It was almost the same as the case of 5.0Kg/cm 2 gauge pressure.
比較例 ２
実施例１と同じ装置を使用して第１段反応系の
温度を140℃、圧力を0.8Kg／cm2ゲージ圧とし第２
段反応系の圧力を0.8Kg／cm2ゲージ圧とした以外
は実施例２と同じ操作を行なつた。得られたイソ
シアナート溶液を蒸留分析したところ23.0％の
TDIおよび3.2％の不揮発性残渣を含有しており
上記結果に比べて残渣の含有量が増大していた。Comparative Example 2 Using the same equipment as in Example 1, the temperature of the first stage reaction system was set to 140°C, the pressure was set to 0.8 Kg/cm 2 gauge pressure, and the second stage reaction system was
The same operation as in Example 2 was carried out except that the pressure in the stage reaction system was set to 0.8 Kg/cm 2 gauge pressure. Distillation analysis of the obtained isocyanate solution revealed that 23.0%
It contained TDI and 3.2% non-volatile residue, and the residue content was increased compared to the above results.
比較例 ３
実施例２と同じ装置を使用して第１段反応系の
温度を120℃とした以外は実施例２と同じ操作を
行なつた。得られたイソシアナート溶液を蒸留分
析したところ24.0％のTDIおよび2.1％の不揮発性
残渣を含有しており上記結果に比べて残渣の含有
量が増大していた。Comparative Example 3 The same operation as in Example 2 was carried out except that the same apparatus as in Example 2 was used and the temperature of the first stage reaction system was set at 120°C. Distillation analysis of the obtained isocyanate solution revealed that it contained 24.0% TDI and 2.1% non-volatile residue, which was increased compared to the above results.
実施例 ３
実施例１と同じ装置を使用し実施例１のTDA
の代りにNH2含量15.9％の粗MDAを原料に用い
たほかは実施例１と全く同じ操作により粗MDI
の製造を行なつた。Example 3 TDA of Example 1 using the same equipment as Example 1
Crude MDI was prepared in exactly the same manner as in Example 1, except that crude MDA with a NH 2 content of 15.9% was used as a raw material instead of
was manufactured.
反応液は蒸留によりＯ−ジクロルベンゼンを留
出し、缶出液を分析したところNCO含量32.5％
粘度40cps（25℃）、HC0.02％の茶褐色の粗MDIが
得られた。 The reaction solution was distilled to remove O-dichlorobenzene, and the bottoms were analyzed and found to have an NCO content of 32.5%.
A brown crude MDI with a viscosity of 40 cps (25°C) and HC of 0.02% was obtained.
図１は、各圧力における温度と、反応液相（溶
媒Ｏ−ジクロルベンゼン中でTDI換算濃度20重量
％溶液）中のホスゲン溶解度との関係図である。
図２は、５Kg／cm2ゲージ圧で反応濃度がTDI換算
で20重量％になるようTDAを装入した時の、循
環ラインの各流速における温度とCOCl2／TDA
のモル比との関係図である。図３は、TDI換算反
応濃度20重量％、圧力５Kg／cm2ゲージ圧における
反応温度と、反応液内のTDIとカルバミルクロラ
イドの平衡濃度との関係図である。図４は、本発
明方法を実施する場合の好ましい１例のフロシー
トであり
１……循環回路中のホスゲン化反応管、４……
循環ポンプ、５……ガス分離器、７……カルバモ
イル分解及びホスゲン化反応槽、９，９′……圧
力調節弁。
FIG. 1 is a diagram showing the relationship between the temperature at each pressure and the solubility of phosgene in the reaction liquid phase (a solution with a TDI equivalent concentration of 20% by weight in the solvent O-dichlorobenzene).
Figure 2 shows the temperature and COCl 2 /TDA at each flow rate in the circulation line when TDA is charged at a reaction concentration of 20% by weight in terms of TDI at 5 Kg/cm 2 gauge pressure.
FIG. FIG. 3 is a diagram showing the relationship between the reaction temperature and the equilibrium concentration of TDI and carbamyl chloride in the reaction solution at a TDI equivalent reaction concentration of 20% by weight and a pressure of 5 kg/cm 2 gauge pressure. FIG. 4 shows a preferred example of a flow sheet for carrying out the method of the present invention. 1... Phosgenation reaction tube in the circulation circuit, 4...
Circulation pump, 5... Gas separator, 7... Carbamoyl decomposition and phosgenation reaction tank, 9, 9'... Pressure control valve.
Claims (1)
機一級アミンとを反応させて対応するイソシアナ
ートを連続的に製造する方法において、 (1) ３〜７Kg／cm2ゲージ圧の加圧下で、温度を60
乃至100℃に維持しながら、管状循環回路中の
反応濃度を10〜30重量％に保ち、アミンおよび
反応の過程で副生するアミン塩酸塩のホスゲン
化を行い、かつ中間生成物のカルバミルクロラ
イドとアミン塩酸塩が反応液の反応濃度10〜30
重量％中に30〜70％存在しているようにイソシ
アナートへ分解させ、 (2) 次にこの反応混合液を120℃乃至160℃の温度
および３〜７Kg／cm2ゲージ圧に維持された第２
段目の反応器に移し、ここで未反応のアミン塩
酸塩のホスゲン化とカルバミルクロライドの分
解を完結させながら行う、 ことを特徴とする加圧２段法による有機イソシア
ナートの連続的製造方法。 ２ 有機一級アミンがトリレンジアミンまたはジ
アミンジフエニルメタンであり、有機イソシアナ
ートがトリレンジイソシアナートまたはジフエニ
ルメタンジイソシアナートである特許請求の範囲
第１項記載の方法。 ３ 不活性有機溶剤がｏ−ジクロルベンゼンであ
る特許請求の範囲第１項記載の方法。 ４ 第一段の反応において循環反応液の滞留時間
が30分乃至120分である特許請求の範囲第１項記
載の方法。[Claims] 1. A method for continuously producing a corresponding isocyanate by reacting a large excess of phosgene with an organic primary amine in the presence of an inert organic solvent, comprising: (1) 3 to 7 Kg/cm 2 gauge pressure; Under pressure and temperature of 60
While maintaining the reaction concentration in the tubular circulation circuit at 10 to 30% by weight while maintaining the temperature at 100°C to 100°C, phosgenation of the amine and amine hydrochloride produced as a by-product in the reaction process is carried out, and the intermediate product carbamyl chloride is and amine hydrochloride in the reaction solution at a reaction concentration of 10 to 30
(2) The reaction mixture was then maintained at a temperature of 120°C to 160°C and a pressure of 3 to 7 kg/cm 2 gauge. Second
A method for continuous production of organic isocyanate by a pressurized two-stage method, characterized in that the organic isocyanate is transferred to a second stage reactor, where the phosgenation of unreacted amine hydrochloride and the decomposition of carbamyl chloride are completed. . 2. The method according to claim 1, wherein the organic primary amine is tolylene diamine or diamine diphenylmethane, and the organic isocyanate is tolylene diisocyanate or diphenylmethane diisocyanate. 3. The method according to claim 1, wherein the inert organic solvent is o-dichlorobenzene. 4. The method according to claim 1, wherein the residence time of the circulating reaction liquid in the first stage reaction is 30 minutes to 120 minutes.
Priority Applications (7)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5121681A JPS57165358A (en) | 1981-04-07 | 1981-04-07 | Continuous preparaion of organic isocyanate |
| US06/364,894 US4422976A (en) | 1981-04-07 | 1982-04-02 | Continuous preparation of organic isocyanates |
| DE3212510A DE3212510A1 (en) | 1981-04-07 | 1982-04-03 | METHOD FOR THE CONTINUOUS PRODUCTION OF ORGANIC ISOCYANATES |
| MX192184A MX156500A (en) | 1981-04-07 | 1982-04-06 | CONTINUOUS PROCEDURE FOR THE PREPARATION OF ORGANIC ISOCYANATES |
| BR8201971A BR8201971A (en) | 1981-04-07 | 1982-04-06 | PROCESS TO PREPARE AN ORGANIC ISOCIANATE CONTINUOUSLY |
| FR8206087A FR2503146B1 (en) | 1981-04-07 | 1982-04-07 | PROCESS FOR THE CONTINUOUS PREPARATION OF ORGANIC ISOCYANATES |
| GB8210299A GB2097789B (en) | 1981-04-07 | 1982-04-07 | Preparation of organic isocyanates |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5121681A JPS57165358A (en) | 1981-04-07 | 1981-04-07 | Continuous preparaion of organic isocyanate |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS57165358A JPS57165358A (en) | 1982-10-12 |
| JPH0124783B2 true JPH0124783B2 (en) | 1989-05-15 |
Family
ID=12880717
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5121681A Granted JPS57165358A (en) | 1981-04-07 | 1981-04-07 | Continuous preparaion of organic isocyanate |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS57165358A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4739798B2 (en) * | 2005-04-05 | 2011-08-03 | 三井化学株式会社 | Polyisocyanate continuous production equipment |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS516126A (en) * | 1974-07-04 | 1976-01-19 | Kobe Steel Ltd | Chukuseikeihinno seikeihoho oyobi sonosochi |
| JPS5356635A (en) * | 1976-11-01 | 1978-05-23 | Allied Chem | Method of and apparatus for producing aromatic isocyanate |
-
1981
- 1981-04-07 JP JP5121681A patent/JPS57165358A/en active Granted
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS516126A (en) * | 1974-07-04 | 1976-01-19 | Kobe Steel Ltd | Chukuseikeihinno seikeihoho oyobi sonosochi |
| JPS5356635A (en) * | 1976-11-01 | 1978-05-23 | Allied Chem | Method of and apparatus for producing aromatic isocyanate |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS57165358A (en) | 1982-10-12 |
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