JPH033652B2 - - Google Patents
Info
- Publication number
- JPH033652B2 JPH033652B2 JP8153382A JP8153382A JPH033652B2 JP H033652 B2 JPH033652 B2 JP H033652B2 JP 8153382 A JP8153382 A JP 8153382A JP 8153382 A JP8153382 A JP 8153382A JP H033652 B2 JPH033652 B2 JP H033652B2
- Authority
- JP
- Japan
- Prior art keywords
- carbonate
- soda
- hydrolysis reaction
- reaction
- calcium hydroxide
- 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
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims description 102
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 claims description 76
- 238000006243 chemical reaction Methods 0.000 claims description 49
- 238000006460 hydrolysis reaction Methods 0.000 claims description 46
- 238000004821 distillation Methods 0.000 claims description 41
- 150000001412 amines Chemical class 0.000 claims description 39
- 239000012948 isocyanate Substances 0.000 claims description 38
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 claims description 37
- 239000000920 calcium hydroxide Substances 0.000 claims description 37
- 229910001861 calcium hydroxide Inorganic materials 0.000 claims description 37
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 claims description 35
- 238000000034 method Methods 0.000 claims description 35
- 239000007788 liquid Substances 0.000 claims description 34
- 235000011121 sodium hydroxide Nutrition 0.000 claims description 34
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 claims description 28
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 24
- 229910000029 sodium carbonate Inorganic materials 0.000 claims description 23
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 claims description 22
- 238000000926 separation method Methods 0.000 claims description 22
- -1 amine compound Chemical class 0.000 claims description 21
- 230000005484 gravity Effects 0.000 claims description 17
- 239000002994 raw material Substances 0.000 claims description 17
- 239000001569 carbon dioxide Substances 0.000 claims description 14
- 229910002092 carbon dioxide Inorganic materials 0.000 claims description 14
- 230000007062 hydrolysis Effects 0.000 claims description 12
- 229910000019 calcium carbonate Inorganic materials 0.000 claims description 11
- 239000011575 calcium Substances 0.000 claims description 4
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 claims description 3
- 229910052791 calcium Inorganic materials 0.000 claims description 3
- BRPQOXSCLDDYGP-UHFFFAOYSA-N calcium oxide Chemical compound [O-2].[Ca+2] BRPQOXSCLDDYGP-UHFFFAOYSA-N 0.000 claims description 3
- 239000000292 calcium oxide Substances 0.000 claims description 3
- ODINCKMPIJJUCX-UHFFFAOYSA-N calcium oxide Inorganic materials [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 claims description 3
- 238000004064 recycling Methods 0.000 claims description 3
- 239000010410 layer Substances 0.000 claims 5
- 239000012044 organic layer Substances 0.000 claims 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 claims 1
- 235000011116 calcium hydroxide Nutrition 0.000 description 31
- 150000002513 isocyanates Chemical class 0.000 description 26
- 239000000243 solution Substances 0.000 description 19
- 239000003513 alkali Substances 0.000 description 10
- 239000012530 fluid Substances 0.000 description 9
- 239000007864 aqueous solution Substances 0.000 description 7
- VOZKAJLKRJDJLL-UHFFFAOYSA-N 2,4-diaminotoluene Chemical compound CC1=CC=C(N)C=C1N VOZKAJLKRJDJLL-UHFFFAOYSA-N 0.000 description 5
- 239000003518 caustics Substances 0.000 description 5
- 239000006227 byproduct Substances 0.000 description 4
- 239000012295 chemical reaction liquid Substances 0.000 description 4
- 238000000354 decomposition reaction Methods 0.000 description 4
- 239000002244 precipitate Substances 0.000 description 4
- 238000010438 heat treatment Methods 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 238000000746 purification Methods 0.000 description 3
- 238000011084 recovery Methods 0.000 description 3
- DVKJHBMWWAPEIU-UHFFFAOYSA-N toluene 2,4-diisocyanate Chemical compound CC1=CC=C(N=C=O)C=C1N=C=O DVKJHBMWWAPEIU-UHFFFAOYSA-N 0.000 description 3
- 239000004202 carbamide Substances 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- 238000006114 decarboxylation reaction Methods 0.000 description 2
- 238000006298 dechlorination reaction Methods 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 230000003301 hydrolyzing effect Effects 0.000 description 2
- 150000004679 hydroxides Chemical class 0.000 description 2
- IQPQWNKOIGAROB-UHFFFAOYSA-N isocyanate group Chemical group [N-]=C=O IQPQWNKOIGAROB-UHFFFAOYSA-N 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 229920002635 polyurethane Polymers 0.000 description 2
- 239000004814 polyurethane Substances 0.000 description 2
- 239000002002 slurry Substances 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- 238000005406 washing Methods 0.000 description 2
- MTZUIIAIAKMWLI-UHFFFAOYSA-N 1,2-diisocyanatobenzene Chemical compound O=C=NC1=CC=CC=C1N=C=O MTZUIIAIAKMWLI-UHFFFAOYSA-N 0.000 description 1
- 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 description 1
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 1
- JOYRKODLDBILNP-UHFFFAOYSA-N Ethyl urethane Chemical compound CCOC(N)=O JOYRKODLDBILNP-UHFFFAOYSA-N 0.000 description 1
- YGYAWVDWMABLBF-UHFFFAOYSA-N Phosgene Chemical compound ClC(Cl)=O YGYAWVDWMABLBF-UHFFFAOYSA-N 0.000 description 1
- 229920005830 Polyurethane Foam Polymers 0.000 description 1
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 description 1
- 230000002745 absorbent Effects 0.000 description 1
- 239000002250 absorbent Substances 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 239000012670 alkaline solution Substances 0.000 description 1
- 239000008346 aqueous phase Substances 0.000 description 1
- 125000003118 aryl group Chemical group 0.000 description 1
- OHJMTUPIZMNBFR-UHFFFAOYSA-N biuret Chemical compound NC(=O)NC(N)=O OHJMTUPIZMNBFR-UHFFFAOYSA-N 0.000 description 1
- 150000001718 carbodiimides Chemical class 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 239000000460 chlorine Substances 0.000 description 1
- 229910052801 chlorine Inorganic materials 0.000 description 1
- 230000003750 conditioning effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 229920001971 elastomer Polymers 0.000 description 1
- 239000000806 elastomer Substances 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 239000006260 foam Substances 0.000 description 1
- 239000002440 industrial waste Substances 0.000 description 1
- ZFSLODLOARCGLH-UHFFFAOYSA-N isocyanuric acid Chemical compound OC1=NC(O)=NC(O)=N1 ZFSLODLOARCGLH-UHFFFAOYSA-N 0.000 description 1
- 239000003973 paint Substances 0.000 description 1
- 238000006068 polycondensation reaction Methods 0.000 description 1
- 239000011496 polyurethane foam Substances 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 230000001172 regenerating effect Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 238000007086 side reaction Methods 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000007790 solid phase Substances 0.000 description 1
Landscapes
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
Description
【発明の詳細な説明】
本発明は、有機イソシアナート類を製造する際
副生する蒸留残渣から連続的に相応する有機アミ
ンを回収する方法に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for continuously recovering a corresponding organic amine from a distillation residue produced as a by-product during the production of organic isocyanates.
有機イソシアナート類はポリウレタンフオー
ム、エラストマー塗料、接着剤など色々の分野に
大量に使用される重要な工業用原料である。 Organic isocyanates are important industrial raw materials used in large quantities in various fields such as polyurethane foams, elastomer paints, and adhesives.
この有機イソシアナート類は一般に対応するア
ミンとホスゲンとの反応により製造されるが、こ
の際いわゆるタールと称される蒸留残渣が生じ
る。 These organic isocyanates are generally produced by reacting the corresponding amine with phosgene, which produces a distillation residue called tar.
このタール成分は有機アミンのホスゲン化工程
における副反応および蒸留工程での熱重縮合など
により生成し、ウレア、ビウレツト、カルボジイ
ミド、イソシアヌレートなどの複雑な重縮合物の
混合物と考えられている。このタール分は硬質ウ
レタンフオーム製造の場合のようにタールを含む
粗イソシアナートのまま使用する以外は通常蒸留
によつて除去される。この蒸留残渣中には蒸留の
方式により残存量は若干異なるが通常の蒸留では
イソシアナートが数10％残存しており、さらにこ
の通常の蒸留残渣からイソシアナートを回収した
残渣には１％程度のイソシアナートが、なお残存
している。 This tar component is produced by side reactions in the phosgenation process of organic amines and thermal polycondensation in the distillation process, and is thought to be a mixture of complex polycondensates such as urea, biuret, carbodiimide, and isocyanurate. This tar content is usually removed by distillation unless the tar-containing crude isocyanate is used as is, such as in the production of rigid urethane foam. The amount of remaining isocyanate in this distillation residue varies slightly depending on the distillation method, but in normal distillation, several tens of percent of isocyanate remains, and in addition, about 1% of isocyanate remains in the residue after recovering isocyanate from this normal distillation residue. Isocyanate still remains.
これら有機イソシアナート類の蒸留残渣の大部
分は、その有効な利用方法もなく産業廃棄物とな
り主として焼却処分されてきた。 Most of the distillation residues of these organic isocyanates have been mainly disposed of by incineration as industrial waste without any effective way to utilize them.
しかし近年ポリウレタン工業の著しい発展に伴
いその原料である有機イソシアナート類の生産も
急速に増加し、この蒸留残渣の処理も大きな環境
問題になつて来た。そこでこの環境問題を緩和し
かつ資源の再生を目的として種々の検討が行なわ
れている。その一つは有機イソシアナート類の蒸
留残渣をアルカリ水溶液の存在下加水分解してア
ミン分解物にして生成した対応するアミンを回収
する方法である。 However, in recent years, with the remarkable development of the polyurethane industry, the production of organic isocyanates, which are raw materials for polyurethane, has rapidly increased, and the treatment of this distillation residue has also become a major environmental problem. Therefore, various studies are being conducted with the aim of alleviating this environmental problem and regenerating resources. One of these methods is to hydrolyze the distillation residue of organic isocyanates in the presence of an aqueous alkali solution to recover the corresponding amine produced as an amine decomposition product.
例えば英国特許第795639号、および米国特許第
3331876号などはいずれも希アルカリ水溶液の存
在下有機イソシアナートの蒸留残渣を加水分解す
ることにより好収率で対応するアミンを回収する
方法が記載されている。 For example, UK Patent No. 795639, and US Patent No.
No. 3,331,876 and the like all describe a method for recovering the corresponding amine in good yield by hydrolyzing the distillation residue of an organic isocyanate in the presence of a dilute aqueous alkaline solution.
上記英国特許第795639号明細書には160〜250℃
の温度での残渣中に含有している少量の塩素の脱
塩素剤として蒸留残渣に対し１％以上の少量の酸
右カルシウムなどを添加してアルカリ性水溶液の
存在下で加水分解反応を行い、得られた反応液に
多量の苛性ソーダなどのアルカリを添加して水に
対するアミンの溶解度を下げ分液して、アミンを
分離蒸留して回収する記載があるが、加水分解反
応を少くとも65atmの高圧下で実施されている。 The specification of British Patent No. 795639 has a temperature of 160 to 250℃.
A small amount of calcium acid, etc. of 1% or more is added to the distillation residue as a dechlorination agent for a small amount of chlorine contained in the residue at a temperature of There is a description of adding a large amount of alkali such as caustic soda to the resulting reaction solution to lower the solubility of the amine in water, separating the amines, and recovering the amines by separate distillation. It is being carried out in
また、米国特許第3331876号明細書には、イソ
シアナート蒸留残渣にその１〜24％（重量）の希
薄な苛性ソーダ水溶液を加えて、260〜350℃の温
度で加水分解反応を行い、得られた反応液を蒸留
してアミンを回収する記憶があり、この場合も加
水分解反応時の反応器の内圧が最高176Kg／cm2に
達している。 Furthermore, in US Pat. No. 3,331,876, a dilute aqueous solution of caustic soda of 1 to 24% (by weight) is added to the isocyanate distillation residue, and a hydrolysis reaction is carried out at a temperature of 260 to 350°C. I remember recovering the amine by distilling the reaction solution, and in this case too, the internal pressure of the reactor during the hydrolysis reaction reached a maximum of 176 kg/cm 2 .
これらの公知文献では、いずれも高圧下で行う
苛酷な条件が必要とされているが、これはイソシ
アナート蒸留残渣中の尿素結合あるいはカルボジ
イミド結合などの基が加水分解を受けてアミンを
生ずる際に、同時に二酸化炭素が生成し、この二
酸化炭素は苛性アルカリと結合して炭酸塩になる
から、生成する二酸化炭素と結合するに充分な量
の苛性アルカリが系内になければ、苛性アルカリ
が消費され尽した後は加水分解の速度が低下する
ためと考えることができる。従つて、これらの公
知文献では酸化カルシウムや、苛性ソーダなどの
アルカリを脱塩素剤や触媒として蒸留残渣に対し
て少量しか用いられていないので、加水分解反応
が進むにつれて発生する二酸化炭素は系外に随時
排出させているものゝ、苛性ソーダは炭酸塩とし
て消費されてしまい、反応速度を高めるために
は、いきおい必要以上の高温高圧にせざるを得な
かつたものと推察される。 All of these known documents require harsh conditions under high pressure, but this is because groups such as urea bonds or carbodiimide bonds in the isocyanate distillation residue undergo hydrolysis to produce amines. At the same time, carbon dioxide is produced, and this carbon dioxide combines with caustic alkali to form carbonate, so if there is not enough caustic alkali in the system to combine with the carbon dioxide produced, the caustic alkali will be consumed. This is thought to be because the rate of hydrolysis decreases after the amount is exhausted. Therefore, in these known documents, only a small amount of calcium oxide or alkali such as caustic soda is used as a dechlorination agent or catalyst for the distillation residue, so the carbon dioxide generated as the hydrolysis reaction progresses is not allowed to escape from the system. The caustic soda, which was discharged from time to time, was consumed as carbonate, and in order to increase the reaction rate, it is assumed that the temperature and pressure had to be higher than necessary.
これらの改良法として、特開昭54−130525公報
は、加水分解反応で発生する二酸化炭素を吸収す
るに充分な量の水酸化カルシウム、または水酸化
カルシウムと苛性アルカリを共存させて比較的低
い圧力、及び温度で反応が実施されている。 As an improvement method for these, Japanese Patent Application Laid-Open No. 130525/1983 discloses that calcium hydroxide or calcium hydroxide and caustic alkali coexist in sufficient amount to absorb carbon dioxide generated in the hydrolysis reaction, and a relatively low pressure is applied. The reaction is carried out at , and temperature.
たしかに、二酸化炭素を吸収するのに充分な量
の多量のアルカリを添加して反応を行えば、低い
圧力で実施できる。また水酸化カルシウムを脱炭
酸吸収剤に用いれば反応後の炭酸塩の固液分離は
容易である。 It is true that the reaction can be carried out at low pressures if a large amount of alkali is added in an amount sufficient to absorb the carbon dioxide. Further, if calcium hydroxide is used as a decarboxylation absorbent, solid-liquid separation of the carbonate after the reaction is easy.
しかしながら本発明者らは水酸化カルシウムの
みを用いた場合、加水分解反応速度が遅くなり従
つて回収収率を上げるためには、苛性アルカリを
併用した場合より、より高温高圧にする必要があ
り、また生成した炭酸塩は水に対して溶解度の低
い水酸カルシウムのみであるので、多量の炭酸カ
ルシウムが反応液中に析出して、これにアミンが
容易に付着するのでその後処理が必要となる。ま
た苛性ソーダを共存させて実施した場合、得られ
た反応液から炭酸カルシウムは固液分離により容
易に分離できるが、液中に多量に溶存している
炭酸ソーダは、このままではアミン分離の蒸留工
程で詰りを生じる欠点を有することもわかつた。 However, the present inventors found that when only calcium hydroxide is used, the hydrolysis reaction rate is slow, and therefore, in order to increase the recovery yield, it is necessary to use higher temperature and pressure than when using caustic alkali together. Furthermore, since the carbonate produced is only calcium hydroxide, which has low solubility in water, a large amount of calcium carbonate precipitates in the reaction solution, and the amine easily adheres to this, requiring subsequent treatment. In addition, when carrying out the reaction in the presence of caustic soda, calcium carbonate can be easily separated from the resulting reaction solution by solid-liquid separation, but a large amount of soda carbonate dissolved in the solution cannot be removed in the distillation process for amine separation. It was also found that it has the disadvantage of causing clogging.
本発明者らはこれら工業的に欠点を有する公知
方法を鋭意検討して、本発明方法を完成させたも
のである。本発明方法は比較的低い温度および圧
力で実施でき、しかもイソシアナート残渣の加水
分解工程で多量に使用されるアルカリの原料とし
て、苛性ソーダは殆んど使用する必要がなく、苛
性ソーダにくらべ安価な水酸化カルシウム（消石
灰）と炭酸ソーダを使用できる、工業的に経済性
の大きいアミン回収方法を提供するものである。 The inventors of the present invention have completed the method of the present invention by intensively studying these known methods that have industrial disadvantages. The method of the present invention can be carried out at relatively low temperatures and pressures, and there is almost no need to use caustic soda as the raw material for the alkali that is used in large amounts in the hydrolysis process of isocyanate residues, and water is cheaper than caustic soda. The present invention provides an industrially economical amine recovery method that can use calcium oxide (slaked lime) and soda carbonate.
即ち本発明方法は、(1)、加水分解反応を、水酸
化カルシウム、及び加水分解反応工程で副生する
炭酸ソーダと水酸化カルシウムの一部とを反応さ
せて得られた苛性ソーダを共存させて反応を行
い、しかもこれらの水酸化物が加水分解反応中に
生成する二酸化炭素の全量を炭酸塩として吸収さ
せるに充分な量存在させて、加圧下、160〜280℃
の比較的温和な条件下で反応を行い、(2)、こうし
て得られる反応溶液は、固液分離して炭酸カルシ
ウムを除去し、液は所定温度に維持して静置す
れば、アミン液層と炭酸ソーダ水溶液層の比重差
により分液ができるよう炭酸ソーダ水溶液層の比
重を、予め加水分解反応系中に必要量の炭酸ソー
ダを加えて比重調整をしておくか、固液分離後に
炭酸ソーダを加えて、比重調整をして分液を行
い、(3)、アミン層は蒸留に付し、炭酸ソーダを含
む水層は、加水分解反応工程へ循環させることを
特徴とした、加水分解工程で安価な水酸化カルシ
ウムを用いる工程をベースに組立てられた、有機
イソシアナート化合物蒸留残渣より連続的に対応
するアミン化合物を回収する方法である。 That is, the method of the present invention includes (1) carrying out the hydrolysis reaction in the coexistence of calcium hydroxide and caustic soda obtained by reacting a part of the calcium hydroxide with soda carbonate, which is a by-product in the hydrolysis reaction step; The reaction is carried out at a temperature of 160 to 280°C under pressure, and these hydroxides are present in a sufficient amount to absorb the entire amount of carbon dioxide produced during the hydrolysis reaction as carbonate.
The reaction is carried out under relatively mild conditions (2), and the resulting reaction solution is solid-liquid separated to remove calcium carbonate, and the liquid is maintained at a predetermined temperature and allowed to stand, forming an amine liquid layer. The specific gravity of the sodium carbonate aqueous solution layer can be adjusted by adding the necessary amount of sodium carbonate to the hydrolysis reaction system in advance, or the specific gravity of the sodium carbonate aqueous solution layer can be adjusted by adding the necessary amount of sodium carbonate to the hydrolysis reaction system, or the specific gravity of the sodium carbonate aqueous solution layer can be separated by the specific gravity difference between A hydrolysis process characterized by adding soda, adjusting the specific gravity, and separating the liquid, (3), subjecting the amine layer to distillation, and circulating the aqueous layer containing soda carbonate to the hydrolysis reaction process. This method is based on a process that uses inexpensive calcium hydroxide, and continuously recovers the corresponding amine compound from the organic isocyanate compound distillation residue.
本発明方法において用いる有機イソシアナート
化合物蒸留残渣とは、一般式Ｒ−NCOで示され
るトリルイソシアナート、キシリルイソシアナー
トなどの芳香族モノイソシアナートや、一般式
OCN−Ｒ−NCOで示されるフエニレンジイソシ
アナート、トリレンジイソシアナート、ナフチレ
ンジイソシアナート、ジフエニルメタンジイソシ
アナートなどの芳香族イソシアナート類などの精
製工程で通常の蒸留により副生する蒸留残渣や、
あるいはこれらの蒸留残渣を、さらに真空下にあ
る加熱管などにより処理して、残存イソシアナー
トが１％以下になつた再処理残渣にも適用でき
る。また、これらのイソシアナート残存量の違う
残渣を適当に混合調整して用いることもできる。 The organic isocyanate compound distillation residue used in the method of the present invention refers to aromatic monoisocyanates such as tolyl isocyanate and xylyl isocyanate represented by the general formula R-NCO, and
Distillation produced by normal distillation in the purification process of aromatic isocyanates such as phenylene diisocyanate, tolylene diisocyanate, naphthylene diisocyanate, and diphenylmethane diisocyanate represented by OCN-R-NCO. Residues and
Alternatively, these distillation residues can be further treated with a heating tube under vacuum, and the reprocessed residue can be used to reduce the residual isocyanate content to 1% or less. Further, these residues having different residual amounts of isocyanate can be appropriately mixed and used.
本発明方法の加水分解工程において、生成する
二酸化炭素の全量を炭酸塩として吸収させるに充
分な量の水酸化カルシウム及び苛性ソーダとは、
これらの水酸化物が二酸化炭素と反応する当量以
上であり、その必要とする総量は、加水分解反応
中に発生する二酸化炭素の量で決まる。そのため
加水分解中に発生する二酸化炭素の量はイソシア
ナート蒸留残渣の種類及び品質によつて異なるの
で、予備的に加水分解を行なつて実測しておく
か、特開昭54−130525公報に記載されている式に
より夫々の残渣に対する必要量を計算できる。 In the hydrolysis step of the method of the present invention, calcium hydroxide and caustic soda are used in amounts sufficient to absorb the entire amount of carbon dioxide produced as carbonate.
The amount of these hydroxides is at least equivalent to react with carbon dioxide, and the total amount required is determined by the amount of carbon dioxide generated during the hydrolysis reaction. Therefore, the amount of carbon dioxide generated during hydrolysis varies depending on the type and quality of the isocyanate distillation residue, so it is best to carry out preliminary hydrolysis and actually measure it, or as described in JP-A-130525-1983. The required amount for each residue can be calculated using the formula given below.
また、この際水酸化カルシウムと併用する苛性
ソーダは反応初回のみに用いればよく、次回以降
の苛性ソーダは、加水分解反応後固液分離した
液中のアミン層と炭酸ソーダ水溶液を分液して炭
酸ソーダ水溶液相を加水分解反応工程へ循環さ
せ、次式に従い得られる。 In addition, at this time, the caustic soda used in combination with calcium hydroxide only needs to be used for the first time of the reaction, and the caustic soda from the next time onwards is obtained by separating the amine layer and the aqueous sodium carbonate solution in the solid-liquid separated liquid after the hydrolysis reaction. The aqueous phase is circulated to the hydrolysis reaction step and obtained according to the following formula.
Ca（OH）2＋Na2O3CaCO3＋2NaOH
反応は過剰量の水酸化カルシウムの存在下で行
なわれるので、次回以降は炭酸ソーダのみの添加
でよく、苛性ソーダの新たな添加は必ずしも必要
ない。Ca(OH) 2 +Na 2 O 3 CaCO 3 +2NaOH Since the reaction is carried out in the presence of an excess amount of calcium hydroxide, only soda carbonate needs to be added from the next time onwards, and new addition of caustic soda is not necessarily required.
第１図は本発明方法を実施する場合の好ましい
態様図であり、これにより詳述する。 FIG. 1 is a diagram showing a preferred embodiment of the method of the present invention, which will be described in detail.
図中、３は原料調整槽、６は加水分解反応器、
８は固液分離器、９は分液槽、１０は循環液中継
槽、４は、循環液貯槽であり、水酸化カルシウム
はここに添加される。 In the figure, 3 is a raw material adjustment tank, 6 is a hydrolysis reactor,
8 is a solid-liquid separator, 9 is a liquid separation tank, 10 is a circulating fluid relay tank, and 4 is a circulating fluid storage tank, to which calcium hydroxide is added.
予めイソシアナート含有量の決定されたイソシ
アナート蒸留残渣は微粉砕されて導管１より３の
原料調整槽へ添加される。また４に添加される水
酸化カルシウムと、９より分液された炭酸ソーダ
水溶液はスラリー状で導管１６を経て３へ混入混
合される。原料調整槽３は40〜90℃に維持されて
いて撹拌下、ここで原料の混合と、水酸化カルシ
ウムの一部と炭酸ソーダの反応が行なわれる。ま
た苛性ソーダ（初回のみ）及び炭酸ソーダは
夫々、２，2′より添加される。水酸化カルシウム
及び苛性ソーダを含むスラリ液は、加圧定量ポン
プ５より加水分解反応器６へ導入される。 The isocyanate distillation residue, the isocyanate content of which has been determined in advance, is pulverized and added to the raw material conditioning tank 3 through conduit 1. Further, the calcium hydroxide added to 4 and the aqueous sodium carbonate solution separated from 9 are mixed into 3 through a conduit 16 in the form of a slurry. The raw material adjustment tank 3 is maintained at a temperature of 40 to 90°C, and the raw materials are mixed and a portion of the calcium hydroxide reacts with soda carbonate while being stirred. Further, caustic soda (only for the first time) and soda carbonate are added from 2 and 2', respectively. A slurry liquid containing calcium hydroxide and caustic soda is introduced into a hydrolysis reactor 6 from a pressurized metering pump 5.
加水分解反応は反応器に直接仕込みバツチでも
可能であるが、前記のように反応器前に調整槽を
設けて実施すれば連続的に反応が出来、操作も容
易であるので好ましい方法である。 Although the hydrolysis reaction can be carried out in batches by directly charging the reactor, it is preferable to carry out the reaction by providing a regulating tank in front of the reactor as described above, since the reaction can be carried out continuously and the operation is easy.
加水分解反応系での水酸化カルシウムと苛性ソ
ーダの割合は、水酸化カルシウムに対して５〜20
モル％の苛性ソーダが存在している状態で反応を
行うのが好ましく、水酸化カルシウムに対し苛性
ソーダが５モル％以下では、水酸化カルシウムを
発生する二酸化炭素の当量以上存在させていて
も、反応が遅く効果に乏しい。また20％以上存在
させても反応には影響なく、その必要はない。反
応系中に苛性ソーダは触媒量程度存在していれば
充分である。 The ratio of calcium hydroxide and caustic soda in the hydrolysis reaction system is 5 to 20% of calcium hydroxide.
It is preferable to carry out the reaction in the presence of mol % of caustic soda. If the amount of caustic soda is less than 5 mol % relative to calcium hydroxide, the reaction will not proceed even if more than the equivalent amount of carbon dioxide that generates calcium hydroxide is present. Slow and ineffective. Moreover, even if it is present in an amount of 20% or more, it does not affect the reaction and is not necessary. It is sufficient that caustic soda is present in a catalytic amount in the reaction system.
通常、次回以降に用いる苛性ソーダは、循環液
貯槽４で添加される水酸化カルシウムと、分液槽
９で、分液されて循環される炭酸ソーダとの反応
のみで充分であり、この反応により得られる苛性
ソーダは殆んど温度に影響なくほぼ定量的に得る
ことができ、加水分解反応前に原料調整槽を設け
て実施すれば、反応系中の炭酸ソーダ及び苛性ソ
ーダの濃度を容易に調整できる。必要な場合は調
整槽へ炭酸ソーダ、または苛性ソーダを適宜添加
して行う。 Normally, for the caustic soda to be used from the next time onwards, it is sufficient to react only with the calcium hydroxide added in the circulating fluid storage tank 4 and the soda carbonate that is separated and circulated in the separating tank 9. The caustic soda produced can be obtained almost quantitatively without being affected by temperature, and if a raw material adjustment tank is provided before the hydrolysis reaction, the concentrations of soda carbonate and caustic soda in the reaction system can be easily adjusted. If necessary, add soda carbonate or caustic soda to the adjustment tank.
また本発明方法では、分液槽でアミン層を分離
するためには炭酸ソーダ水溶液層の比重が1.05以
上なければ分液できないので、そのためには反応
系中の炭酸ソーダの濃度は少くとも６％以上有し
ていなければならず、たとえイソシアナート含有
量の多い蒸留残渣を用いる場合でも加水分解反応
で生成できる炭酸ソーダのみでは不足するので、
もし分液槽で炭酸ソーダを添加しなければ、原料
調整槽で新たな炭酸ソーダを添加して反応液中の
炭酸ソーダの濃度を６％以上に調整しながら反応
を行う必要がある。炭酸ソーダを新たに添加した
場合、加水分解反応系中では水酸化カルシウムは
若干減少しその分だけ苛性ソーダが増加するが、
加水分解反応時の脱炭酸作用は苛性ソーダが若干
優先するので、反応液中の炭酸ソーダは相対的に
増加する。 In addition, in the method of the present invention, in order to separate the amine layer in the separation tank, the sodium carbonate aqueous solution layer must have a specific gravity of 1.05 or more to separate the layers, so the concentration of sodium carbonate in the reaction system must be at least 6%. Even if distillation residue with a high isocyanate content is used, soda carbonate produced by hydrolysis reaction alone will not be sufficient.
If soda carbonate is not added in the liquid separation tank, it is necessary to carry out the reaction while adjusting the concentration of soda carbonate in the reaction solution to 6% or more by adding new sodium carbonate in the raw material adjustment tank. When newly adding soda carbonate, calcium hydroxide decreases slightly in the hydrolysis reaction system, and caustic soda increases by that amount.
Since caustic soda has a slightly higher decarboxylation effect during the hydrolysis reaction, the amount of soda carbonate in the reaction solution increases relatively.
加水分解反応器は、サンプル口を設けた撹拌及
び外部加熱用ジヤケツト付の密閉型耐圧反応槽よ
りなり、通常のオートクレーブが使用できる。反
応は加圧下、好ましくは25atm以下で、160〜280
℃、好ましくは180〜250℃の温度で行う。160℃
以下の温度では、イソシアナートのアミンへの分
解率が低く、特にイソシアナート含有量が１％以
下の残渣からはアミンの回収は殆んどできない。
また280℃以上の温度にすれば、それだけより高
価な耐圧反応装置が必要になり、より高温にして
も分解率も殆んど変らない。イソシアナート残渣
を加水分解する場合、通常用いられる水の量は水
酸化カルシウムに対し２〜４倍量用いる。密閉型
反応槽槽を用いて所定温度に反応を維持すれば内
圧が最高20〜25atm付近迄達するが、反応は
25atm以下で充分実施でき、25atm付近に調節し
た制御弁を反応器に設けてもよい。また反応温度
は通常、１〜５時間でよいが滞留時間を短くする
ため複数の反応槽を直例に設けて溢流管で連結さ
せて行つてもよい。 The hydrolysis reactor consists of a closed pressure-resistant reaction tank equipped with a sample port and a jacket for stirring and external heating, and an ordinary autoclave can be used. The reaction is carried out under pressure, preferably below 25 atm, between 160 and 280
It is carried out at a temperature of 180-250°C, preferably 180-250°C. 160℃
At temperatures below, the rate of decomposition of isocyanate to amine is low, and in particular, it is almost impossible to recover amine from a residue containing 1% or less of isocyanate.
Furthermore, if the temperature is increased to 280°C or higher, a more expensive pressure-resistant reactor will be required, and the decomposition rate will hardly change even if the temperature is increased. When hydrolyzing isocyanate residues, the amount of water usually used is 2 to 4 times the amount of calcium hydroxide. If the reaction is maintained at a specified temperature using a closed type reaction tank, the internal pressure will reach a maximum of around 20 to 25 atm, but the reaction will not continue.
The reaction can be carried out satisfactorily at 25 atm or less, and the reactor may be provided with a control valve adjusted to around 25 atm. Further, the reaction temperature may normally be 1 to 5 hours, but in order to shorten the residence time, a plurality of reaction vessels may be directly provided and connected by overflow pipes.
加水分解反応が完結した反応液は、減圧弁７を
通じてフラツシユタンクに導入され（図示せず）、
50〜100℃まで冷却されこの温度で、好ましくは
60〜80℃で遠心分離器８で固液分離され、ここで
炭酸カルシウムが除去される。固液分離の際50℃
以下ではアミンが析出するので好ましくない。本
発明方法で得られるスラリ状の反応液中には炭酸
塩として炭酸カルシウムだけでなく炭酸ソーダも
水溶液として含まれていて、静置した場合生成ア
ミン化合物は炭酸ソーダ水溶液と二層を形成する
かエマルジヨン化していて、固相の炭酸カルシウ
ム沈澱物とは隔離されているので沈澱物へのアミ
ンの付着は極めて少ない。所望なら分離後炭酸カ
ルシウムケーキを水洗して付着のアミンをさらに
回収してもよい。 The reaction liquid in which the hydrolysis reaction has been completed is introduced into the flash tank through the pressure reducing valve 7 (not shown).
Cooled to 50-100°C, preferably at this temperature
Solid-liquid separation is performed in a centrifuge 8 at 60 to 80°C, and calcium carbonate is removed here. 50℃ during solid-liquid separation
The following is not preferable because the amine will precipitate. The slurry-like reaction solution obtained by the method of the present invention contains not only calcium carbonate as a carbonate but also sodium carbonate as an aqueous solution, and when left standing, the produced amine compound forms two layers with the aqueous sodium carbonate solution. Since it is emulsionized and separated from the solid phase calcium carbonate precipitate, there is very little amine adhesion to the precipitate. If desired, the calcium carbonate cake may be washed with water after separation to further recover the deposited amine.
固液分離された反応液は、次に分液槽９へ導
入され60〜90℃に維持されて、アミン液層と炭酸
ソーダを含む水層に分液される。 The solid-liquid separated reaction liquid is then introduced into a separation tank 9, maintained at 60 to 90°C, and separated into an amine liquid layer and an aqueous layer containing sodium carbonate.
その際、水層の比重が1.05以上であれば静置す
るだけで容易に分液できるが、比重が1.05未満な
らば、炭酸ソーダを貯槽１２より分液槽へ添加
し、水層の炭酸ソーダの温度を増加させて比重の
調整を行う。水層の比重が1.05以上であれば分液
できるが、炭酸ソーダを過剰に加えて1.20以上の
比重にする必要はなく、炭酸ソーダを必要量以上
添加するのは分液後の操作が不利になるので避け
たがよい。 At that time, if the specific gravity of the aqueous layer is 1.05 or more, it can be easily separated by simply leaving it to stand still, but if the specific gravity is less than 1.05, soda carbonate is added from the storage tank 12 to the separation tank, and the aqueous layer is The specific gravity is adjusted by increasing the temperature. Separation is possible if the specific gravity of the aqueous layer is 1.05 or more, but there is no need to add too much sodium carbonate to make the specific gravity more than 1.20, and adding more than the required amount of sodium carbonate will result in disadvantageous operations after separation. Therefore, it is best to avoid it.
分液槽９は、外部加熱用ジヤケツト付きの槽で
あり60〜90℃、好ましくは80〜85℃に維持されて
いる。60℃未満ではアミンの析出が生じる場合も
あり、90℃を越えると静置状態にしずらく、分液
効果に乏しい。 The separation tank 9 is a tank equipped with an external heating jacket, and is maintained at a temperature of 60 to 90°C, preferably 80 to 85°C. If the temperature is lower than 60°C, amine precipitation may occur, and if the temperature exceeds 90°C, it is difficult to keep it still and the liquid separation effect is poor.
この温度で数分静置しておけば、上層のアミン
と油層と下層の炭酸ソーダ水溶液層に分液するの
でアミン層は粗アミン受器１３に移し、アミン蒸
発缶１４で蒸留精製に付し、１５より回収され
る。 If left at this temperature for several minutes, the liquid will separate into an upper amine and oil layer and a lower sodium carbonate aqueous solution layer, so the amine layer is transferred to the crude amine receiver 13 and subjected to distillation purification in the amine evaporator 14. , 15.
また下層の炭酸ソーダの溶存している水層は、
循環水中継槽１０へ移され、水酸化カルシウムが
添加されている循環液貯槽４を経由して、定量ポ
ンプで導管１６を通つて原料調整槽３へ戻され
る。また反応系中の水分量は、４の循環液貯槽、
または３の原料調整槽や、固液分離した炭酸カル
シウムを所望なら水洗する時に、系中に適宜加え
て調整されるが、次回以降の分液した水層を循環
し始めたら、アミン液層にはほとんど水分は含ま
れないのでフラツシユ工程などで蒸発されるロス
分だけ追加すればよい。 In addition, the lower layer of water containing dissolved soda is
It is transferred to the circulating water relay tank 10, passes through the circulating fluid storage tank 4 to which calcium hydroxide is added, and is returned to the raw material adjustment tank 3 through the conduit 16 using a metering pump. In addition, the amount of water in the reaction system is determined by the circulating fluid storage tank in 4.
Alternatively, when washing the solid-liquid separated calcium carbonate in the raw material adjustment tank described in step 3, or washing it with water, it is added to the system as appropriate for adjustment. contains almost no water, so only the loss that evaporates during the flashing process etc. needs to be added.
このように本発明方法は、加水分解反応工程で
副生物として生成する炭酸ソーダを苛性ソーダ源
として使用し、しかも反応は苛性ソーダの共存下
過剰量の水酸化カルシウムを存在させて行うの
で、加水分解は比較的温和な条件で収率よく分解
反応を行うことができる。また反応液中の炭酸ソ
ーダ及び水は分液によりアミン層より分離される
のでアミン回収工程においては、工程中の炭酸ソ
ーダのつまりもなく、水分除去のための熱エネル
ギーの消費も少く連続的に実施できるものであ
る。 As described above, the method of the present invention uses sodium carbonate produced as a by-product in the hydrolysis reaction step as a caustic soda source, and the reaction is carried out in the presence of an excess amount of calcium hydroxide in the coexistence of caustic soda. The decomposition reaction can be carried out with good yield under relatively mild conditions. In addition, since the sodium carbonate and water in the reaction solution are separated from the amine layer by liquid separation, the amine recovery process is continuous, with no clogging of soda carbonate during the process, and less thermal energy consumption for water removal. It is something that can be implemented.
以下実施例を示す。 Examples are shown below.
実施例 １
２，４−トルエンジイソシアナート（以下トル
エンジイソシアナートをTDIと略す。）を製造す
る際（組成比２、４−TDI80％、２、６−TDI20
％）、精製工程で副生した蒸留残渣（蒸留可能な
イソシアナート含有率50％）を、16メツシユ以下
に粉砕した残渣80ｇ、水酸化カルシウム51.6ｇ、
苛性ソーダ10.8ｇ（対水酸化カルシウム39モル
％）、及び水162.7ｇを内容物500mlのオートクレ
ーブに仕込み、210〜220℃、20〜22Kg／cm2Ｇの条
件下で撹拌しながら１時間加水分解反応を続け
た。反応液を800℃まで冷却し、同温度で排出液
を遠心分離器にかけ、固液分離した。水酸化カル
シウムケーキを分離した反応液は、静置しても分
液されず、これに80℃に維持しながら炭酸ソーダ
を徐々加え、26.0ｇ添加したら二層に分液した。
この時の水層の比重は1.15であつた。上層のアミ
ン層を蒸留に付し、44ｇ（収率55％）のトルエン
ジアミンを回収した。Example 1 When producing 2,4-toluene diisocyanate (hereinafter toluene diisocyanate is abbreviated as TDI) (composition ratio 2,4-TDI80%, 2,6-TDI20
%), 80g of distillation residue (distillable isocyanate content: 50%), which is a by-product of the purification process, is crushed into 16 meshes or less, 51.6g of calcium hydroxide,
10.8 g of caustic soda (39 mol% of calcium hydroxide) and 162.7 g of water were placed in a 500 ml autoclave, and a hydrolysis reaction was carried out for 1 hour with stirring at 210 to 220°C and 20 to 22 Kg/cm 2 G. continued. The reaction solution was cooled to 800°C, and the discharged solution was centrifuged at the same temperature to separate solid and liquid. The reaction solution from which the calcium hydroxide cake had been separated did not separate into liquids even if it was allowed to stand still. Soda carbonate was gradually added to this while maintaining the temperature at 80°C, and when 26.0g was added, the liquid was separated into two layers.
The specific gravity of the water layer at this time was 1.15. The upper amine layer was subjected to distillation to recover 44 g (yield 55%) of toluenediamine.
下層より分離した炭酸ソーダを含む水層に水を
加えて210ｇとした後、第１回目反応と同様TDI
蒸留残渣80ｇ、水酸化カルシウム51.6ｇとともに
オートクレーブに仕込み第１回目と全く同様にし
て、反応、固液分離を行い、この反応液に第１回
目と同様な条件下で炭酸ソーダ5.0ｇを加えたら、
水層の比重は1.15となり、分液された。アミン層
を蒸留に付し37.0ｇのトルエンジアミンを回収し
た。 After adding water to the aqueous layer containing soda carbonate separated from the lower layer to make 210 g, TDI was added as in the first reaction.
80g of the distillation residue and 51.6g of calcium hydroxide were placed in an autoclave, and the reaction and solid-liquid separation were carried out in exactly the same manner as the first time.To this reaction solution, 5.0g of soda carbonate was added under the same conditions as the first time. ,
The water layer had a specific gravity of 1.15 and was separated. The amine layer was subjected to distillation to recover 37.0 g of toluenediamine.
以下同様分液された水層をリサイクルして、第
２回目と同じ量の蒸留残渣、水酸化カルシウム、
及び水の量を一定にして同じ条件下３回目、４回
目の反応を行い、第２回目と同じく夫々の回に炭
酸ソーダ5.0ｇを加えて分液してアミンを蒸留に
付して、第３回目37.0ｇ、第４回目37.5ｇのトル
エンジアミンを夫々得た。 The same amount of distillation residue, calcium hydroxide, and
A third and fourth reaction was carried out under the same conditions with the amount of water kept constant, and as in the second reaction, 5.0 g of soda carbonate was added in each reaction to separate the liquids, and the amine was distilled. 37.0 g of toluenediamine was obtained from the third time and 37.5 g from the fourth time.
実施例 ２
蒸留可能なイソシアナート含有率が１％以下の
微粉砕したTDI蒸留残渣80ｇを原料として用いた
以外は、実施例１と全く同様に、反応を行なつ
た。Example 2 A reaction was carried out in exactly the same manner as in Example 1, except that 80 g of finely pulverized TDI distillation residue having a distillable isocyanate content of 1% or less was used as the raw material.
水層をリサイクルして反応を４回行なつたが、
トルエンジアミンの平均収量は35.0ｇであつた。 The reaction was carried out four times by recycling the aqueous layer, but
The average yield of toluenediamine was 35.0 g.
実施例 ３
第１図において、蒸留可能なイソシアナートの
含有率が１％以下の微粉砕されたTDI蒸留残渣を
276Kg／hrの流量で原料調整槽３に装入し、同時
に45％苛性ソーダ水を9.6Kg／hr（２回目以降の分
液水層をリサイクルしはじめた後は苛性ソーダ水
のフイードはストツプし、炭酸ソーダを10Kg／hr
で装入した。）を添加した。一方、循環液貯槽４
に、水酸化カルシウムを、178Kg／hrの流量で、
700Kg／hrの水（２回目以降の分液水層をリサイ
クルし始めた後は、水の装入量は20Kg／hrとし
た。）とともに装入し、これをポンプで原料調整
槽へ移した。ここで50℃で３時間撹拌された原料
液をポンプ５にて反応器６に圧入し、ここで220
℃において２時間、22Kg／cm2Ｇ圧で加水分解反応
を行なつた。反応器よりサンプリングし、分析の
結果、反応液中のアミン度が一定に達した後、反
応液はフラツシユ減圧及び80℃まで冷却して、遠
心分離器８に装入され、この温度で水酸化カルシ
ウムは分離された。液をメスシリンダに採取す
ると数分で分液し、水層中の炭酸ソーダは８％含
まれていて比重は1.14であつた。80℃に維持され
た液は分液槽９へ装入、分液されたアミン層は
受器１３をへて、蒸留器１４で蒸留され、アミン
受器１５に補集された。一方分離水層は、循環液
中継槽１０をへて、循環液貯槽４に戻された。Example 3 In Figure 1, finely ground TDI distillation residue containing 1% or less of distillable isocyanate is
Charge the raw material adjustment tank 3 at a flow rate of 276Kg/hr, and at the same time feed 45% caustic soda water at 9.6Kg/hr (after starting to recycle the separated water layer from the second time onwards, the feed of caustic soda water will be stopped and carbonated 10Kg/hr of soda
I charged it with ) was added. On the other hand, the circulating fluid storage tank 4
, calcium hydroxide at a flow rate of 178Kg/hr,
It was charged with 700Kg/hr of water (after the second and subsequent recycling of the separated water layer started, the amount of water charged was 20Kg/hr), and this was transferred to the raw material adjustment tank using a pump. . Here, the raw material solution stirred at 50°C for 3 hours was pressurized into the reactor 6 using the pump 5, and the 220°C
The hydrolysis reaction was carried out at 22 kg/cm 2 G pressure for 2 hours at °C. After sampling from the reactor and analyzing the amine level in the reaction liquid to reach a certain level, the reaction liquid was flash-reduced and cooled to 80°C, charged into a centrifugal separator 8, and hydroxylated at this temperature. Calcium was isolated. When the liquid was collected into a graduated cylinder, it separated in a few minutes, and the aqueous layer contained 8% sodium carbonate and had a specific gravity of 1.14. The liquid maintained at 80° C. was charged into a separation tank 9, and the separated amine layer passed through a receiver 13, was distilled in a distiller 14, and collected in an amine receiver 15. On the other hand, the separated aqueous layer passed through the circulating fluid relay tank 10 and was returned to the circulating fluid storage tank 4.
このような方法を４回繰返し得られたトルエン
ジアミンの平均収量は118Kg／hr（収率42.8％）で
あつた。 The average yield of toluenediamine obtained by repeating this method four times was 118 Kg/hr (yield 42.8%).
第１図は本発明方法を実施する場合の好ましい
フローシートの一例である。
３……原料調整槽、４……循環液貯槽、６……
加水分解反応器、８……固液分離器、９……分液
槽、１０……循環液中継槽、１３……粗アミン受
器。
FIG. 1 is an example of a preferred flow sheet for carrying out the method of the present invention. 3... Raw material adjustment tank, 4... Circulating fluid storage tank, 6...
Hydrolysis reactor, 8... solid-liquid separator, 9... liquid separation tank, 10... circulating liquid relay tank, 13... crude amine receiver.
Claims (1)
酸化カルシウムと苛性ソーダの共存下、加水分解
反応をして対応するアミン化合物を回収する方法
において、工程、 (1) 加水分解反応に水酸化カルシウム、及び水酸
化カルシウムと工程(4)で回収した炭酸ソーダを
反応させて得られる苛性ソーダを共存させ、こ
れらをイソシアナート化合物の加水分解反応に
よつて生成する二酸化炭素の全量を炭酸塩化合
物として吸収させるに充分な量存在させ、同時
に工程(3)、で得られる炭酸ソーダを含む水層の
比重が1.05以上になるよう充分な量の炭酸ソー
ダを添加しておき、加圧下160〜280℃で加水分
解反応を行ない、 (2) 得られた反応溶液を50〜100℃で固液分離し
て炭酸カルシウムを除去し、 (3) 得られた液を60〜90℃に維持してアミン化
合物有機層と、炭酸ソーダを含む水層の二層に
分液して、 (4) アミン化合物有機層は蒸留に付し、炭酸ソー
ダを含む水層は、加水分解反応工程へ循環させ
る工程よりなる有機イソシアナート化合物蒸留
残渣より対応するアミン化合物を回収する方
法。 ２ 有機イソシアナート化合物の蒸留残渣より水
酸化カルシウムと苛性ソーダの共存下、加水分解
反応をして対応するアミン化合物を回収する方法
において、工程、 (1) 加水分解反応に水酸化カルシウム、及び水酸
化カルシウムと工程(4)で回収した炭酸ソーダを
反応させて得られた苛性ソーダを共存させ、こ
れらをイソシアナート化合物の加水分解反応に
よつて生成する二酸化炭素の全量を炭酸塩化合
物として吸収させるに充分な量存在させ、加圧
下、160〜280℃で反応を行い、 (2) 得られた反応溶液を50〜100℃で固液分離し
て炭酸カルシウムを除去し、 (3) 得られた液に、60〜90℃に維持して炭酸ソ
ーダを添加して炭酸ソーダを含む水層の比重が
1.05以上になるように調整して、アミン化合物
有機相と、炭酸ソーダを含む水層の二層に分液
して、 (4) アミン化合物有機層は蒸留に付し、炭酸ソー
ダを含む水層は、加水分解反応工程へ循環させ
る、工程よりなる有機イソシアナート化合物蒸
留残渣より対応するアミン化合物を回収する方
法。 ３ 加水分解反応工程前に、原料調整槽を設け、
水酸化カルシウムの一部と炭酸ソーダを反応させ
た後、加水分解反応工程へ導入する特許請求の範
囲第１項記載の方法。 ４ 加水分解工程で共存している苛性ソーダが水
酸化カルシウムに対し５〜20モル％である特許請
求の範囲第１項ないし第２項記載の方法。 ５ 分液工程の炭酸ソーダを含む水層の比重が
1.05〜1.20に調整されている特許請求の範囲第１
項ないし第２項記載の方法。[Claims] 1. A method for recovering a corresponding amine compound by performing a hydrolysis reaction in the coexistence of calcium hydroxide and caustic soda from a distillation residue of an organic isocyanate compound, comprising the steps of: (1) adding water to the hydrolysis reaction; Calcium oxide and caustic soda obtained by reacting calcium hydroxide with the soda carbonate recovered in step (4) are allowed to coexist, and the total amount of carbon dioxide produced by the hydrolysis reaction of the isocyanate compound is converted into a carbonate compound. At the same time, a sufficient amount of sodium carbonate is added so that the specific gravity of the aqueous layer containing sodium carbonate obtained in step (3) is 1.05 or more, and 160 to 280 carbonate is added under pressure. (2) Perform solid-liquid separation of the resulting reaction solution at 50-100°C to remove calcium carbonate; (3) Maintain the resulting solution at 60-90°C to remove amines. (4) The amine compound organic layer is subjected to distillation, and the aqueous layer containing soda carbonate is recycled to the hydrolysis reaction process. A method for recovering a corresponding amine compound from a distillation residue of an organic isocyanate compound. 2. A method for recovering a corresponding amine compound by performing a hydrolysis reaction in the coexistence of calcium hydroxide and caustic soda from a distillation residue of an organic isocyanate compound, comprising the steps of: (1) adding calcium hydroxide and hydroxide to the hydrolysis reaction; Caustic soda obtained by reacting calcium with the soda carbonate recovered in step (4) is allowed to coexist, and these are sufficient to absorb the entire amount of carbon dioxide produced by the hydrolysis reaction of the isocyanate compound. (2) The resulting reaction solution is subjected to solid-liquid separation at 50-100°C to remove calcium carbonate; (3) Calcium carbonate is added to the resulting liquid. , the specific gravity of the aqueous layer containing sodium carbonate is increased by maintaining the temperature at 60-90℃ and adding soda carbonate.
(4) The amine compound organic layer is subjected to distillation, and the aqueous layer containing soda carbonate is separated. is a method for recovering a corresponding amine compound from a distillation residue of an organic isocyanate compound, which comprises a step of recycling the organic isocyanate compound to a hydrolysis reaction step. 3 Before the hydrolysis reaction process, a raw material adjustment tank is installed,
The method according to claim 1, wherein a portion of calcium hydroxide and sodium carbonate are reacted and then introduced into the hydrolysis reaction step. 4. The method according to claim 1 or 2, wherein the amount of caustic soda coexisting in the hydrolysis step is 5 to 20 mol % based on calcium hydroxide. 5 The specific gravity of the aqueous layer containing soda carbonate in the liquid separation process is
Claim 1 adjusted to 1.05-1.20
The method described in Items 1 to 2.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8153382A JPS58201751A (en) | 1982-05-17 | 1982-05-17 | Recovery of amine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8153382A JPS58201751A (en) | 1982-05-17 | 1982-05-17 | Recovery of amine |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS58201751A JPS58201751A (en) | 1983-11-24 |
| JPH033652B2 true JPH033652B2 (en) | 1991-01-21 |
Family
ID=13748945
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP8153382A Granted JPS58201751A (en) | 1982-05-17 | 1982-05-17 | Recovery of amine |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS58201751A (en) |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0976719B1 (en) * | 1997-02-05 | 2005-01-05 | Kabushiki Kaisha Kobe Seiko Sho | Apparatus and method for decomposing and recovering isocyanate compound |
| DE19827086A1 (en) * | 1998-06-18 | 1999-12-23 | Basf Ag | Process for working up distillation residues from the synthesis of tolylene diisocyanate |
| KR100578607B1 (en) * | 2003-06-09 | 2006-05-10 | 한화석유화학 주식회사 | Method for Recovering Toluene Diamine from High Boiling Tar Residue Discharged from Toluene Diisocyanate Preparation Process |
| DE102007020444A1 (en) | 2007-04-27 | 2008-11-06 | Bayer Materialscience Ag | Process for the oxidation of a hydrogen chloride-containing gas mixture |
| WO2009127591A2 (en) * | 2008-04-14 | 2009-10-22 | Basf Se | Method for treating residues from the production of isocyanates |
| CN102633651B (en) | 2011-01-27 | 2013-10-02 | 沧州丰源环保科技有限公司 | Toluene diamine recovery from tar waste residues discharged during toluene diisocyanate synthesis |
| TW201930259A (en) * | 2017-12-27 | 2019-08-01 | 日商旭化成股份有限公司 | Method for collecting organic amine |
| CN110511132A (en) * | 2019-09-20 | 2019-11-29 | 兰州理工大学 | A kind of TDI residue method for hydrolysis for using dolomite as catalyst |
| CN113387814B (en) * | 2021-06-11 | 2023-06-13 | 兰州理工大学 | TDI residue hydrolysis method using magnesite and sodium hydroxide as mixed treating agents |
-
1982
- 1982-05-17 JP JP8153382A patent/JPS58201751A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS58201751A (en) | 1983-11-24 |
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