JP2002037756A - Acetic anhydride - Google Patents
Acetic anhydrideInfo
- Publication number
- JP2002037756A JP2002037756A JP2001107959A JP2001107959A JP2002037756A JP 2002037756 A JP2002037756 A JP 2002037756A JP 2001107959 A JP2001107959 A JP 2001107959A JP 2001107959 A JP2001107959 A JP 2001107959A JP 2002037756 A JP2002037756 A JP 2002037756A
- Authority
- JP
- Japan
- Prior art keywords
- acetic anhydride
- ozone
- ozonized
- treatment
- heat treatment
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- WFDIJRYMOXRFFG-UHFFFAOYSA-N Acetic anhydride Chemical compound CC(=O)OC(C)=O WFDIJRYMOXRFFG-UHFFFAOYSA-N 0.000 title claims abstract description 365
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims abstract description 38
- 238000010438 heat treatment Methods 0.000 claims abstract description 32
- 238000004040 coloring Methods 0.000 claims abstract description 21
- 241001550224 Apha Species 0.000 claims abstract description 17
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 claims description 97
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 51
- 239000000543 intermediate Substances 0.000 description 28
- 238000000034 method Methods 0.000 description 27
- 238000004821 distillation Methods 0.000 description 22
- 238000000746 purification Methods 0.000 description 18
- CCGKOQOJPYTBIH-UHFFFAOYSA-N ethenone Chemical compound C=C=O CCGKOQOJPYTBIH-UHFFFAOYSA-N 0.000 description 16
- WASQWSOJHCZDFK-UHFFFAOYSA-N diketene Chemical compound C=C1CC(=O)O1 WASQWSOJHCZDFK-UHFFFAOYSA-N 0.000 description 15
- 150000001875 compounds Chemical class 0.000 description 11
- 238000005987 sulfurization reaction Methods 0.000 description 10
- 238000009835 boiling Methods 0.000 description 9
- 238000004519 manufacturing process Methods 0.000 description 9
- 239000012535 impurity Substances 0.000 description 8
- 239000002994 raw material Substances 0.000 description 8
- 238000006243 chemical reaction Methods 0.000 description 7
- 239000000047 product Substances 0.000 description 7
- 230000000052 comparative effect Effects 0.000 description 6
- 239000007788 liquid Substances 0.000 description 6
- 229920002301 cellulose acetate Polymers 0.000 description 5
- 238000000354 decomposition reaction Methods 0.000 description 5
- 238000010992 reflux Methods 0.000 description 5
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 4
- 229920000106 Liquid crystal polymer Polymers 0.000 description 4
- ZFOZVQLOBQUTQQ-UHFFFAOYSA-N Tributyl citrate Chemical compound CCCCOC(=O)CC(O)(C(=O)OCCCC)CC(=O)OCCCC ZFOZVQLOBQUTQQ-UHFFFAOYSA-N 0.000 description 4
- 238000001514 detection method Methods 0.000 description 4
- 239000007789 gas Substances 0.000 description 4
- 229920006324 polyoxymethylene Polymers 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- 239000004977 Liquid-crystal polymers (LCPs) Substances 0.000 description 3
- 229930182556 Polyacetal Natural products 0.000 description 3
- 125000000218 acetic acid group Chemical group C(C)(=O)* 0.000 description 3
- 239000007864 aqueous solution Substances 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 238000005979 thermal decomposition reaction Methods 0.000 description 3
- 108010011485 Aspartame Proteins 0.000 description 2
- YASYVMFAVPKPKE-UHFFFAOYSA-N acephate Chemical compound COP(=O)(SC)NC(C)=O YASYVMFAVPKPKE-UHFFFAOYSA-N 0.000 description 2
- 239000012345 acetylating agent Substances 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 239000000605 aspartame Substances 0.000 description 2
- IAOZJIPTCAWIRG-QWRGUYRKSA-N aspartame Chemical compound OC(=O)C[C@H](N)C(=O)N[C@H](C(=O)OC)CC1=CC=CC=C1 IAOZJIPTCAWIRG-QWRGUYRKSA-N 0.000 description 2
- 229960003438 aspartame Drugs 0.000 description 2
- 235000010357 aspartame Nutrition 0.000 description 2
- 239000003814 drug Substances 0.000 description 2
- 239000000975 dye Substances 0.000 description 2
- 239000012467 final product Substances 0.000 description 2
- 235000003599 food sweetener Nutrition 0.000 description 2
- 238000004817 gas chromatography Methods 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- WGCNASOHLSPBMP-UHFFFAOYSA-N hydroxyacetaldehyde Natural products OCC=O WGCNASOHLSPBMP-UHFFFAOYSA-N 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 239000004014 plasticizer Substances 0.000 description 2
- 229920000642 polymer Polymers 0.000 description 2
- -1 polyoxytetramethylene Polymers 0.000 description 2
- 239000003765 sweetening agent Substances 0.000 description 2
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 1
- 241001292396 Cirrhitidae Species 0.000 description 1
- XBDQKXXYIPTUBI-UHFFFAOYSA-M Propionate Chemical compound CCC([O-])=O XBDQKXXYIPTUBI-UHFFFAOYSA-M 0.000 description 1
- 229920002472 Starch Polymers 0.000 description 1
- 229920004482 WACKER® Polymers 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- KXKVLQRXCPHEJC-UHFFFAOYSA-N acetic acid trimethyl ester Natural products COC(C)=O KXKVLQRXCPHEJC-UHFFFAOYSA-N 0.000 description 1
- 150000004075 acetic anhydrides Chemical class 0.000 description 1
- 239000003905 agrochemical Substances 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000005587 bubbling Effects 0.000 description 1
- 229910002091 carbon monoxide Inorganic materials 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 229940079593 drug Drugs 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000011049 filling Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 238000006385 ozonation reaction Methods 0.000 description 1
- 239000000575 pesticide Substances 0.000 description 1
- 238000000197 pyrolysis Methods 0.000 description 1
- AKHNMLFCWUSKQB-UHFFFAOYSA-L sodium thiosulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=S AKHNMLFCWUSKQB-UHFFFAOYSA-L 0.000 description 1
- 235000019345 sodium thiosulphate Nutrition 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 239000008107 starch Substances 0.000 description 1
- 235000019698 starch Nutrition 0.000 description 1
- 238000004448 titration Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
(57)【要約】
【課題】 精製された無水酢酸であって、加
熱等により着色等の品質問題が生じない無水酢酸を提供
する。
【解決手段】 ８０〜１２０℃、５時間以上の加
熱処理を施した後の硫酸着色試験の値が１０ＡＰＨＡ以
下であることを特徴とする無水酢酸。
PROBLEM TO BE SOLVED: To provide a purified acetic anhydride which does not cause a quality problem such as coloring due to heating or the like. SOLUTION: Acetic anhydride characterized in that the value of a sulfuric acid coloring test after heat treatment at 80 to 120 ° C for 5 hours or more is 10 APHA or less.
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、例えば酢酸を熱分
解してケテンを得、酢酸にそのケテンを吸収反応せしめ
る方法等によって製造される無水酢酸に関するものであ
る。無水酢酸は酢酸セルロースの原料、医薬、農薬（ア
セフェート等）、染料、洗顔料、甘味料（アスパルテー
ム等）、可塑剤（クエン酸トリブチル等）、高分子分野
（ポリオキシテトラメチレングリコール、ポリアセター
ル、液晶ポリマー等）などに広く用いられている。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to acetic anhydride produced by, for example, a method in which acetic acid is pyrolyzed to obtain ketene, and the acetic acid is allowed to absorb the ketene. Acetic anhydride is a raw material of cellulose acetate, pharmaceuticals, agricultural chemicals (acephate, etc.), dyes, face wash, sweeteners (aspartame, etc.), plasticizers (tributyl citrate, etc.), polymer fields (polyoxytetramethylene glycol, polyacetal, liquid crystal) Polymer).
【０００２】[0002]
【従来の技術】無水酢酸の工業的な製造方法としては、
酢酸を熱分解してケテンを得、酢酸にそのケテンを吸収
反応せしめて無水酢酸を得るケテン法（ワッカー法）、
酢酸メチルに一酸化炭素を反応せしめて無水酢酸を得る
ハルコン法等が知られているが、従来、酢酸の熱分解に
よるケテン法が一般的である。ケテン法において、酢酸
を熱分解して得られたケテンを酢酸に吸収反応せしめて
得られる粗製無水酢酸中には不飽和化合物などの不純物
が少なからず混入している。2. Description of the Related Art An industrial method for producing acetic anhydride includes:
A ketene method (wacker method) in which acetic acid is thermally decomposed to obtain ketene, and the ketene is absorbed and reacted with acetic acid to obtain acetic anhydride.
The Halcon method and the like for obtaining acetic anhydride by reacting carbon monoxide with methyl acetate are known, and the ketene method by thermal decomposition of acetic acid is generally used. In the ketene method, impurities such as unsaturated compounds are mixed in the crude acetic anhydride obtained by subjecting ketene obtained by thermally decomposing acetic acid to an acetic acid to cause an absorption reaction.
【０００３】また、無水酢酸は、その原料酢酸として酢
酸セルロース製造工程から排出される酢酸水溶液から濃
縮回収された酢酸が使用される場合があり、この濃縮酢
酸には酢酸セルロース製造工程からの不純物が完全に除
去されずに含まれるため、製造された粗製無水酢酸もそ
れらの影響を受ける。As acetic anhydride, acetic acid concentrated and recovered from an aqueous acetic acid solution discharged from a cellulose acetate production process may be used as a raw material acetic acid, and the concentrated acetic acid contains impurities from the cellulose acetate production process. The crude acetic anhydride produced is also affected because it is included without complete removal.
【０００４】粗製無水酢酸は、以上のように、低沸点及
び高沸点の不飽和化合物などの不純物を含むため、通
常、蒸留によって脱低沸及び脱高沸を行なう。しかしな
がら、蒸留による精製は、多大な熱エネルギーを必要と
し、また、無水酢酸に沸点が近かったり、共沸するもの
は、十分に分離できない。このような蒸留による精製の
問題を解決するため、特開平４−３４５３７号には、ケ
テン炉を通して得られる粗製無水酢酸、すなわち無水酢
酸（ＡＡ）と酢酸（ＡＣ）との混合物（ＡＡ／ＡＣ≒８
０／２０）に対してオゾン処理する精製法が開示されて
いる。粗製無水酢酸をオゾン処理することにより、不飽
和化合物などの不純物はオゾン化され、オゾン化中間体
の生成を経て、分解される。なお、オゾン処理された粗
製無水酢酸中には、不飽和化合物などの不純物がオゾン
化され、オゾン化中間体を経て分解した分解生成物が存
在する他に、分解する前のオゾン化中間体が存在し、ま
た、未反応のオゾンが溶存オゾンとして存在する。しか
しながら、この処理後の無水酢酸は酢酸セルロース製造
工程で使用され得るが、純度が低いため、ある種の方法
にはさらに高純度な無水酢酸が求められている。[0004] As described above, crude acetic anhydride contains impurities such as unsaturated compounds having a low boiling point and a high boiling point, and thus is usually subjected to deboiling and deboiling by distillation. However, purification by distillation requires a large amount of heat energy, and acetic anhydride having a boiling point close to or azeotropic cannot be sufficiently separated. In order to solve such a problem of purification by distillation, JP-A-4-34537 discloses a crude acetic anhydride obtained through a ketene furnace, that is, a mixture of acetic anhydride (AA) and acetic acid (AC) (AA / AC @). 8
0/20) is disclosed. By subjecting the crude acetic anhydride to ozone treatment, impurities such as unsaturated compounds are ozonized and decomposed via generation of an ozonized intermediate. In the ozone-treated crude acetic anhydride, impurities such as unsaturated compounds are ozonized, and in addition to the decomposition products decomposed through the ozonized intermediate, the ozonized intermediate before decomposition is also present. Present and unreacted ozone is present as dissolved ozone. However, acetic anhydride after this treatment can be used in the cellulose acetate production process, but because of its low purity, certain methods require even higher purity acetic anhydride.
【０００５】そこで、特開平６−２５０７１号には、オ
ゾン処理した後、蒸留する粗製無水酢酸の精製法が開示
されている。この方法では、不飽和化合物などの不純物
がオゾン化され生じた分解生成物、さらにオゾン化中間
体、および溶存オゾンが、蒸留により除去されて、高純
度に精製される。Therefore, Japanese Patent Application Laid-Open No. Hei 6-25071 discloses a method for purifying crude acetic anhydride which is subjected to ozone treatment and distillation. In this method, decomposition products generated by ozonation of impurities such as unsaturated compounds, ozonized intermediates, and dissolved ozone are removed by distillation and purified to high purity.
【０００６】しかしながら、オゾン処理後に蒸留する方
法により精製した無水酢酸においても、不飽和化合物な
どの不純物が存在し、また、加熱によって、着色等の品
質問題が発生することが判明した。また、オゾン処理後
に蒸留する方法により精製した無水酢酸を有機薬品のア
セチル化剤等として用いる場合、例えば、ポリオキシテ
トラメチレングリコール（ＰＴＭＧ）の製造等の場合、
硫酸等の酸と共に使用したり、加熱を施したりすること
で、ＰＴＭＧ等の最終製品が着色し、最終製品の品質の
低下を引き起こすことも判明した。However, it has been found that impurities such as unsaturated compounds also exist in acetic anhydride purified by a method of distillation after ozone treatment, and that quality problems such as coloring occur by heating. Further, when acetic anhydride purified by a method of distillation after ozone treatment is used as an acetylating agent of an organic chemical, for example, in the case of production of polyoxytetramethylene glycol (PTMG),
It has also been found that the use of an acid such as sulfuric acid or the like or the application of heat causes coloring of a final product such as PTMG, which causes deterioration in the quality of the final product.
【０００７】[0007]
【発明が解決しようとする課題】本発明の目的は、精製
された無水酢酸であって、加熱等により着色等の品質問
題が生じない無水酢酸を提供することである。SUMMARY OF THE INVENTION An object of the present invention is to provide a purified acetic anhydride which does not cause any quality problems such as coloring due to heating or the like.
【０００８】[0008]
【課題を解決するための手段】本発明者らは、上記目的
を達成するため鋭意検討した結果、上記のようにオゾン
処理後に蒸留する方法により精製するよりも、例えば蒸
留後にオゾン処理する方法により精製し、さらに、無水
酢酸中にオゾン化中間体および溶存オゾンを適量存在さ
せた状態にすることにより、無水酢酸の加熱による着色
が抑えられることを見出し、本発明を完成した。Means for Solving the Problems The present inventors have conducted intensive studies to achieve the above object, and as a result, for example, a method of performing ozone treatment after distillation, rather than a method of purifying by distillation after ozone treatment, as described above. The present inventors have found that coloring is suppressed by heating of acetic anhydride by purifying the acetic anhydride to make a state in which an ozonized intermediate and dissolved ozone are present in an appropriate amount, thereby completing the present invention.
【０００９】すなわち、本発明は、８０〜１２０℃、５
時間以上の加熱処理を施した後の硫酸着色試験の値が１
０ＡＰＨＡ以下であることを特徴とする無水酢酸であ
る。That is, the present invention provides a method for producing
The value of sulfuric acid coloring test after heat treatment for more than 1 hour is 1
An acetic anhydride characterized by being not more than 0 APHA.
【００１０】本発明の請求項２の発明は、オゾン処理し
て製造される純度９５％以上の無水酢酸であって、８０
〜１２０℃、５時間以上の加熱処理を施した後の硫酸着
色試験の値が１０ＡＰＨＡ以下であることを特徴とする
無水酢酸である。According to a second aspect of the present invention, there is provided acetic anhydride having a purity of 95% or more, which is produced by ozone treatment.
An acetic anhydride characterized by having a value of a sulfuric acid coloring test of not more than 10 APHA after subjected to a heat treatment at 120 ° C. for 5 hours or more.
【００１１】本発明の請求項３の発明は、オゾン処理し
て製造される純度９５％以上の無水酢酸であって、溶存
オゾン及びオゾン化中間体を含有し、かつ８０〜１２０
℃、５時間以上の加熱処理を施した後の硫酸着色試験の
値が１０ＡＰＨＡ以下であることを特徴とする無水酢酸
である。According to a third aspect of the present invention, there is provided acetic anhydride having a purity of 95% or more, which is produced by ozone treatment, which contains dissolved ozone and an ozonated intermediate, and is 80 to 120%.
An acetic anhydride characterized by having a sulfuric acid coloring test value of 10 APHA or less after a heat treatment at 5 ° C. for 5 hours or more.
【００１２】本発明の請求項４の発明は、オゾン処理し
て製造される純度９５％以上の無水酢酸であって、溶存
オゾン及びオゾン化中間体を合計の含有率がオゾン換算
で１５〜２００ｐｐｍ含有し、かつ８０〜１２０℃、５
時間以上の加熱処理を施した後の硫酸着色試験の値が１
０ＡＰＨＡ以下であることを特徴とする無水酢酸であ
る。According to a fourth aspect of the present invention, there is provided acetic anhydride having a purity of 95% or more produced by ozone treatment, wherein the total content of dissolved ozone and ozonized intermediate is 15 to 200 ppm in terms of ozone. 80-120 ° C, 5
The value of sulfuric acid coloring test after heat treatment for more than 1 hour is 1
An acetic anhydride characterized by being not more than 0 APHA.
【００１３】本発明の請求項５の発明は、オゾン処理し
て製造される純度９５％以上の無水酢酸であって、溶存
オゾン及びオゾン化中間体を含有し、オゾン化中間体の
含有率が５〜２００ｐｐｍであり、かつ８０〜１２０
℃、５時間以上の加熱処理を施した後の硫酸着色試験の
値が１０ＡＰＨＡ以下であることを特徴とする無水酢酸
である。According to a fifth aspect of the present invention, there is provided acetic anhydride having a purity of 95% or more, which is produced by ozone treatment, wherein the acetic anhydride contains dissolved ozone and an ozonized intermediate, and the content of the ozonized intermediate is reduced. 5 to 200 ppm, and 80 to 120 ppm
An acetic anhydride characterized by having a sulfuric acid coloring test value of 10 APHA or less after a heat treatment at 5 ° C. for 5 hours or more.
【００１４】本発明の請求項６の発明は、オゾン処理し
て製造される純度９５％以上の無水酢酸に加熱処理を施
して製造された無水酢酸である。[0014] The invention of claim 6 of the present invention is acetic anhydride produced by subjecting acetic anhydride having a purity of 95% or more produced by ozone treatment to heat treatment.
【００１５】[0015]
【発明の実施の形態】本発明の無水酢酸は、例えば、前
記したケテン法によって製造される粗製無水酢酸に対
し、蒸留した後にオゾン処理を施すという二段階の精製
処理を行うことによって製造され、また、例えば、上記
の精製処理の後、さらに加熱処理を施して製造される。
以上のような製造法により、精製無水酢酸中にオゾン化
中間体および溶存オゾンを存在させた状態にし、オゾン
化中間体および溶存オゾンの量を調整することができ
る。原料粗製無水酢酸は、無水酢酸の製造工程中、どの
ような濃度の粗製無水酢酸であっても良い。しかし、反
応工程より得られる粗製無水酢酸中の不純物が多くなる
ほど、後述するオゾン含有ガスの消費量が多くなるた
め、粗製無水酢酸中に含有される例えばジケテン等の二
重結合成分量がより少なくなる反応条件を選んで、粗製
無水酢酸を製造するのが望ましい。BEST MODE FOR CARRYING OUT THE INVENTION The acetic anhydride of the present invention is produced, for example, by subjecting crude acetic anhydride produced by the above-mentioned ketene method to a two-stage purification treatment of subjecting the crude acetic anhydride to an ozone treatment after distillation. In addition, for example, after the above-mentioned purification treatment, it is produced by further performing a heat treatment.
By the production method as described above, the ozonized intermediate and dissolved ozone can be made to exist in the purified acetic anhydride, and the amounts of the ozonized intermediate and dissolved ozone can be adjusted. The raw crude acetic anhydride may be any concentration of crude acetic anhydride during the process of producing acetic anhydride. However, as the amount of impurities in the crude acetic anhydride obtained from the reaction step increases, the consumption of the ozone-containing gas described later increases, so that the amount of double bond components such as diketene contained in the crude acetic anhydride is smaller. Preferably, the reaction conditions are selected to produce crude acetic anhydride.
【００１６】粗製無水酢酸を蒸留して一次精製する際に
使用される蒸留塔の形式に特に制限はなく、自由に選択
することができる。一般的にはシーブトレイ、バブルキ
ャップトレイ、バルブトレイ等の棚段塔、インタロック
スサドル、ポールリング、スルザーパック等の充填塔の
うちから一つまたは二つ以上選択して用いることが可能
でる。The type of distillation column used for the primary purification by distilling the crude acetic anhydride is not particularly limited and can be freely selected. Generally, one or two or more selected from tray columns such as a sieve tray, a bubble cap tray, and a valve tray, and packed columns such as an interlock saddle, a pole ring, and a sulzer pack can be used.
【００１７】棚段塔の場合は、トレイ数は２０〜８０個
程度、充填塔の場合はそれに相当する充填高さを有する
ものを使用するのが好ましい。粗製無水酢酸は、蒸留塔
の中間部、望ましくは蒸留塔中央部よりも上方から導入
され、この原料導入段より下方、望ましくは蒸留塔中央
部よりも下部から精製無水酢酸が蒸気または液で回収さ
れる。In the case of a plate tower, it is preferable to use about 20 to 80 trays, and in the case of a packed tower, it is preferable to use a tray having a filling height corresponding thereto. The crude acetic anhydride is introduced from the middle of the distillation column, preferably from above the center of the distillation column, and purified acetic anhydride is recovered as vapor or liquid from below this raw material introduction stage, preferably from below the center of the distillation column. Is done.
【００１８】蒸留塔の操作圧力については特に制限はな
いが、圧力が高すぎる場合、塔内温度の上昇により望ま
しくない反応が起こるおそれがあり、逆に圧力が低すぎ
る場合、塔頂における蒸気の凝縮に困難を伴う。したが
って、望ましい操作圧力は、塔頂において１００ｍｍＨ
ｇ〜常圧の範囲である。The operating pressure of the distillation column is not particularly limited, but if the pressure is too high, an undesirable reaction may occur due to an increase in the temperature in the column. Conversely, if the pressure is too low, the vapor Difficult to condense. Therefore, the desired operating pressure is 100 mmH
g to normal pressure.
【００１９】塔頂蒸気の凝縮液の一部は還流液として塔
頂に戻されるが、回収液流量に対する還流液流量の比、
いわゆる還流比は原料液の組成、求められる製品品質等
により決定される。通常０．５〜１０００程度、好まし
くは１〜１００程度の範囲から選択できる。A part of the condensate of the vapor at the top is returned to the top as a reflux liquid, and the ratio of the flow rate of the reflux liquid to the flow rate of the recovered liquid is as follows:
The so-called reflux ratio is determined by the composition of the raw material liquid, the required product quality, and the like. Usually, it can be selected from the range of about 0.5 to 1000, preferably about 1 to 100.
【００２０】次に、上記のような蒸留塔を用いて一次精
製された無水酢酸に対し、オゾン処理にて二次精製する
場合、これに用いるオゾン含有ガスにも特に制限はな
い。工業的には、一般に空気あるいは酸素を原料とし、
無声放電によりオゾンを発生させる方式が用いられる。
通常、空気原料の場合、オゾンの濃度は５〜２５ｇ／Ｎ
ｍ3、好ましくは１０〜２０ｇ／Ｎｍ3である。Next, when acetic anhydride which has been primarily purified using the above-mentioned distillation column is subjected to secondary purification by ozone treatment, the ozone-containing gas used for the purification is not particularly limited. Industrially, generally, air or oxygen is used as a raw material,
A method of generating ozone by silent discharge is used.
Usually, in the case of an air raw material, the concentration of ozone is 5 to 25 g / N.
m 3 , preferably 10 to 20 g / Nm 3 .
【００２１】無水酢酸と接触させるオゾンの割合は、蒸
留により一次精製された無水酢酸中に含まれる不飽和化
合物量、オゾン自身の分解反応等を考慮し、反応を完全
に完結させた後に残留する溶存オゾンが１０〜１００ｐ
ｐｍ、好ましくは１０〜６０ｐｐｍ、さらに好ましくは
１０〜５０ｐｐｍとなるように、オゾンを仕込む。実用
上はさらに気液の接触効率や精製率等を考慮して実験に
より適宜決められるが、通常、このときのオゾン使用率
は５０〜３００ｇ−Ｏ3／Ｔであり、好ましくは９０〜
２７０ｇ−Ｏ3／Ｔである。The ratio of ozone to be brought into contact with acetic anhydride remains after the reaction has been completely completed in consideration of the amount of unsaturated compounds contained in acetic anhydride primarily purified by distillation, the decomposition reaction of ozone itself, and the like. Dissolved ozone is 10-100p
pm, preferably 10 to 60 ppm, more preferably 10 to 50 ppm. Practically, it is appropriately determined by experiments in consideration of gas-liquid contact efficiency, purification rate, and the like. Usually, the ozone usage rate at this time is 50 to 300 g-O 3 / T, preferably 90 to 300 g-O 3 / T.
Is a 270g-O 3 / T.
【００２２】オゾン処理の反応器の形式は、オゾンと無
水酢酸の接触が良好に行えるのならば特に制限はない
が、実用上は気泡塔方式、攪拌槽方式、充填塔方式が好
ましい。また、接触時間は、数十秒〜数十分の範囲で適
切な時間を設定すれば良い。反応温度は室温付近が適当
であり、好ましくは２０〜４０℃程度である。温度が低
すぎると反応速度が低下し、温度が高すぎるとオゾン自
身が分解し易くなったり、オゾン分解度が低下したりす
るので好ましくない。The type of the reactor for ozone treatment is not particularly limited as long as the contact between ozone and acetic anhydride can be carried out well, but in practice, a bubble column system, a stirred tank system and a packed column system are preferable. Further, the contact time may be set to an appropriate time within a range of several tens of seconds to several tens of minutes. The reaction temperature is suitably around room temperature, preferably about 20 to 40 ° C. If the temperature is too low, the reaction rate decreases, and if the temperature is too high, ozone itself is easily decomposed and the degree of ozone decomposition is undesirably reduced.
【００２３】蒸留した後、オゾン処理した精製無水酢酸
を、さらに加熱処理する場合の加熱処理の条件として
は、８０〜１２０℃で５〜２０時間の範囲に設定すれば
良い。When the purified acetic anhydride that has been distilled and then subjected to ozone treatment is further subjected to heat treatment, the heat treatment may be performed at a temperature of 80 to 120 ° C. for 5 to 20 hours.
【００２４】このように、粗製無水酢酸を蒸留して一次
精製した後、上述したように設定されるオゾン含有ガス
処理による二次精製を行うことによって、また、上記の
精製処理の後、さらに加熱処理を施して精製することに
よって、本発明の無水酢酸が製造される。As described above, the crude acetic anhydride is distilled and subjected to the primary purification, and then the secondary purification is performed by the ozone-containing gas treatment set as described above. The acetic anhydride of the present invention is produced by performing treatment and purification.
【００２５】上記のようにして得られた本発明の無水酢
酸は、純度が９５％以上、好ましくは９９％以上であ
り、溶存オゾン及び、オゾン処理時に不飽和化合物がオ
ゾンによって酸化されて生成したオゾン化中間体を含有
し、溶存オゾン及びオゾン化中間体の合計の含有率が、
オゾン換算で１５〜２００ｐｐｍである。そのうちオゾ
ン化中間体の含有率は５〜２００ｐｐｍであるが、オゾ
ン化中間体の含有率は一次精製の蒸留条件により変化し
得る。すなわち不飽和化合物の除去量及びオゾン処理法
によって変わってくる。The acetic anhydride of the present invention obtained as described above has a purity of 95% or more, preferably 99% or more, and is formed by oxidizing dissolved ozone and unsaturated compounds by ozone during ozone treatment. Contains an ozonated intermediate, the total content of dissolved ozone and ozonized intermediate is
It is 15 to 200 ppm in terms of ozone. Among them, the content of the ozonized intermediate is 5 to 200 ppm, but the content of the ozonized intermediate can be changed depending on the distillation conditions of the primary purification. That is, it depends on the removal amount of the unsaturated compound and the ozone treatment method.
【００２６】以上、本発明の無水酢酸を得る方法とし
て、粗製無水酢酸を蒸留した後にオゾン処理する精製法
について述べたが、この精製法に限られず、本発明の８
０〜１２０℃、５時間以上の加熱処理を施した後の硫酸
着色試験の値が１０ＡＰＨＡ以下という条件をクリアー
する無水酢酸であればどのような精製法によって得られ
た無水酢酸であってもよい。本発明の無水酢酸は、例え
ば加熱等によっても新たな不飽和化合物の発生が抑えら
れ、したがって色相の悪化を生じず、その品質が安定し
て維持される。したがって本発明の無水酢酸は、前記Ｐ
ＴＭＧの製品に使用する無水酢酸の用途以外にも、酢酸
セルロースの原料、医薬、農薬（アセフェート等）、染
料、洗顔料、甘味料（アスパルテーム等）、可塑剤（ク
エン酸トリブチル等）、高分子分野（ポリアセタール、
液晶ポリマー等）等の用途に適用され得るが、特にポリ
アセタール、液晶ポリマーが好適である。また、それら
の用途に限らずどのような用途にも適用可能だが、例え
ば熱を加える処理が必要な用途に使用することができ
る。本発明の無水酢酸は、８０〜１２０℃、５時間以
上、好ましくは６時間以上、さらに好ましくは１０時間
以上、さらに６０時間以上の加熱処理を施した後の硫酸
着色試験の値が１０ＡＰＨＡ以下である。硫酸着色試験
（硫着試験）は、サンプル３０ｍｌに硫酸０．３ｍｌを
加え２５℃で５分間経過後その着色状態をＡＰＨＡで表
現することで実施される。硫着試験の着色状態を表わす
ＡＰＨＡ値が低いものが品質の良い無水酢酸である。As described above, as a method for obtaining acetic anhydride of the present invention, a purification method in which crude acetic anhydride is distilled and then treated with ozone has been described. However, the present invention is not limited to this purification method.
The acetic anhydride obtained by any purification method may be any acetic anhydride that satisfies the condition that the value of the sulfuric acid coloring test after performing the heat treatment at 0 to 120 ° C. for 5 hours or more satisfies the condition of 10 APHA or less. . In the acetic anhydride of the present invention, the generation of new unsaturated compounds is suppressed even by, for example, heating, so that the hue does not deteriorate and the quality thereof is stably maintained. Therefore, the acetic anhydride of the present invention is obtained by using the above P
In addition to the use of acetic anhydride used in TMG products, raw materials for cellulose acetate, medicines, pesticides (acephate, etc.), dyes, face wash, sweeteners (aspartame, etc.), plasticizers (tributyl citrate, etc.), polymers Fields (Polyacetal,
Liquid crystal polymer), but polyacetal and liquid crystal polymer are particularly preferable. Further, the present invention can be applied not only to those applications but also to any applications, but for example, it can be used for applications requiring heat treatment. The acetic anhydride of the present invention has a value of a sulfuric acid coloring test at 80 to 120 ° C. of 5 hours or more, preferably 6 hours or more, more preferably 10 hours or more, and further after 60 hours or more, of 10 APHA or less. is there. The sulfuric acid coloring test (sulfurization test) is performed by adding 0.3 ml of sulfuric acid to 30 ml of the sample, expressing the coloring state by APHA after 5 minutes at 25 ° C. Acetic anhydride of good quality has a low APHA value indicating the coloring state in the sulfuration test.
【００２７】[0027]
【実施例】以下、実施例および比較例を挙げて本発明を
説明するが、本発明はこれらによって限定されるもので
はない。The present invention will be described below with reference to examples and comparative examples, but the present invention is not limited to these examples.
【００２８】実施例１ ケテン炉を通して酢酸の熱分解によって得られたケテン
を酢酸に吸収させて粗製無水酢酸を得、この粗製無水酢
酸を、操作圧力をそれぞれ常圧にした脱低沸塔と脱高沸
塔とを順次通して、一次精製処理を行った。次いで、こ
の一次精製処理した無水酢酸に対し、図１に示す実験装
置を用いてオゾン処理を行った。なお、図１において、
１はオゾン発生器、２は充填塔である。空気を原料とし
てオゾン発生器１によりオゾンを発生させ、このオゾン
発生器１から出るオゾン化空気（オゾンと空気の混合ガ
ス）を、外径５ｍｍ×高さ５ｍｍのラシヒリングを装填
した充填塔２に、その下部から導入した。このときのオ
ゾン化空気量は４２ＮＬ／Ｈ、オゾン濃度１９．０ｇ／
Ｎｍ3、オゾン流入量１６．６ｍｍｏｌ／Ｈである。一
方、充填塔２の上部から、前記のように蒸留による一次
精製処理を行った粗製無水酢酸を、仕込み、オゾンと向
流接触させて、オゾン処理を行った。オゾン処理された
製品無水酢酸は、充填塔２の下部から抜き取り、これを
回収した。このときの無水酢酸の仕込流量は６００６ｇ
／Ｈで、オゾン使用率は１３３ｇ−Ｏ3／Ｔである。こ
うして得られた精製無水酢酸の純度は９９．５％、溶存
オゾンとオゾン化中間体との合計の含有率はオゾン換算
で９２ｐｐｍ、このうち、オゾン化中間体の含有率は６
９ｐｐｍであった。なお、溶存オゾンとオゾン化中間体
との合計の含有率の測定は、ＫＩ法に従って下記のよう
な手順で行った。 試料１０ｇに純水１００ｇを入れて加水分解させて２
０分放置。 サンプル１０ｃｃに０．２ＮＫＩ水溶液３０ｃｃ添
加。 ２Ｎ硫酸水溶液５ｃｃ添加。 冷蔵庫（５℃）で２０分以上冷却。 チオ硫酸ナトリウム滴定（指示薬澱粉水溶液）。 このような測定により、溶存オゾンとオゾン化中間体と
のオゾン換算での合計含有率を求めた。一方、溶存オゾ
ンとオゾン化中間体とが混在する無水酢酸中での溶存オ
ゾンの含有率の測定は、所定量のジケテンを添加し、こ
のジケテンの残量をガスクロマトグラフ分析によって測
定することによって行った（以下、ＤＫ法という）。す
なわち、ジケテンを添加するとこれが溶存オゾンによっ
て酸化され、溶存オゾンと同量のジケテンが消失する。
したがって、ジケテンの添加量から、測定されたジケテ
ン残量を引いた減少量、すなわち、溶存オゾンとの反応
で消失したジケテン量を求めて、この量を溶存オゾン量
とすることができる。また、前記したＫＩ法によって求
められた溶存オゾン及びオゾン化中間体の合計含有率か
ら、ＤＫ法によって求められた溶存オゾンの含有率を引
いた値を、オゾン化中間体の含有率とした。なお、不飽
和化合物としてのジケテン濃度の測定を併せて行った。
その濃度は、粗製無水酢酸では７６ｐｐｍ、得られた製
品無水酢酸でのジケテン濃度は検出限界（２ｐｐｍ）以
下であった。ジケテン濃度の分析は、ガスクロマトグラ
フィー（カラム；ＤＢ−１（キャピラリーカラム）、検
出器；ＦＩＤ）で行った。上記で得られた精製無水酢酸
について、硫酸着色試験（硫着試験）を下記の方法で行
った。すなわち、サンプル３０ｍｌに硫酸０．３ｍｌを
加え２５℃で５分間経過後その着色状態をＡＰＨＡで表
わした。次に、上記で得られた精製無水酢酸について、
１１０℃で６時間の加熱処理をした後、上記の方法と同
様にして、硫着試験を行った。また、加熱処理後の精製
無水酢酸の硫着試験について、さらに試験時間を１０時
間、３０時間、６０時間にして行った。以上の無水酢酸
についての各測定値をまとめて表１に示した。Example 1 Ketene obtained by thermal decomposition of acetic acid was absorbed into acetic acid through a ketene furnace to obtain crude acetic anhydride. The crude acetic anhydride was removed from a low-boiling tower having a normal operating pressure and a low-boiling tower. The primary purification treatment was performed by sequentially passing through a high boiling tower. Next, the acetic anhydride subjected to the primary purification treatment was subjected to an ozone treatment using the experimental apparatus shown in FIG. In FIG. 1,
1 is an ozone generator and 2 is a packed tower. Ozone is generated by an ozone generator 1 using air as a raw material, and ozonized air (mixed gas of ozone and air) emitted from the ozone generator 1 is supplied to a packed tower 2 equipped with a Raschig ring having an outer diameter of 5 mm and a height of 5 mm. , Introduced from the bottom. At this time, the amount of ozonized air was 42 NL / H, and the ozone concentration was 19.0 g / hour.
Nm 3 and the ozone inflow rate were 16.6 mmol / H. On the other hand, the crude acetic anhydride which had been subjected to the primary purification treatment by distillation as described above was charged from the upper portion of the packed tower 2 and brought into countercurrent contact with ozone to perform ozone treatment. The ozone-treated product acetic anhydride was withdrawn from the lower part of the packed tower 2 and collected. At this time, the charging flow rate of acetic anhydride was 6006 g.
/ H, the ozone usage rate is 133 g-O 3 / T. The purity of the purified acetic anhydride thus obtained was 99.5%, the total content of dissolved ozone and the ozonized intermediate was 92 ppm in terms of ozone, and the content of the ozonized intermediate was 6 ppm.
It was 9 ppm. The total content of the dissolved ozone and the ozonized intermediate was measured by the following procedure according to the KI method. 100 g of pure water was added to 10 g of the sample and hydrolyzed.
Leave for 0 minutes. Add 30cc of 0.2NKI aqueous solution to 10cc of sample. 5 cc of 2N sulfuric acid aqueous solution was added. Cool in refrigerator (5 ° C) for more than 20 minutes. Sodium thiosulfate titration (indicator starch aqueous solution). By such measurement, the total content of dissolved ozone and the ozonized intermediate in terms of ozone was determined. On the other hand, the measurement of the content of dissolved ozone in acetic anhydride in which dissolved ozone and an ozonized intermediate are mixed is performed by adding a predetermined amount of diketene and measuring the remaining amount of diketene by gas chromatography analysis. (Hereinafter referred to as the DK method). That is, when diketene is added, it is oxidized by dissolved ozone, and the same amount of diketene as dissolved ozone disappears.
Therefore, the amount of diketene added is calculated by subtracting the measured amount of diketene from the added amount of diketene, that is, the amount of diketene that has disappeared in the reaction with dissolved ozone, and this amount can be used as the amount of dissolved ozone. The value obtained by subtracting the content of dissolved ozone obtained by the DK method from the total content of dissolved ozone and the ozonized intermediate obtained by the KI method was defined as the content of the ozonized intermediate. In addition, the measurement of the diketene concentration as an unsaturated compound was also performed.
The concentration was 76 ppm for crude acetic anhydride, and the diketene concentration in the obtained product acetic anhydride was below the detection limit (2 ppm). The diketene concentration was analyzed by gas chromatography (column; DB-1 (capillary column), detector; FID). The purified acetic anhydride obtained above was subjected to a sulfuric acid coloring test (sulfurization test) by the following method. That is, 0.3 ml of sulfuric acid was added to 30 ml of the sample, and after 5 minutes at 25 ° C., the colored state was represented by APHA. Next, regarding the purified acetic anhydride obtained above,
After a heat treatment at 110 ° C. for 6 hours, a sulfurization test was performed in the same manner as described above. Further, the sulfuric acid test of the purified acetic anhydride after the heat treatment was further performed for 10 hours, 30 hours, and 60 hours. Table 1 summarizes the measured values of acetic anhydride described above.
【００２９】実施例２ 実施例１における無水酢酸の製造工程中、オゾン処理時
に充填塔２に導入したオゾン化空気量を１２０ＮＬ／Ｈ
とした以外は、実施例１と同様の方法で無水酢酸を製造
した。得られた精製無水酢酸の純度は９９．５％、溶存
オゾンとオゾン化中間体との合計含有率はオゾン換算で
１２４ｐｐｍ、このうち、オゾン化中間体の含有率は１
１２ｐｐｍであった。また、ジケテン濃度は検出限界
（２ｐｐｍ）以下であった。上記で得られた精製無水酢
酸およびこれを１１０℃で６時間の加熱処理をしたもの
について、実施例１と同様にして硫着試験を行った。無
水酢酸についての各測定値をまとめて表１に示した。Example 2 In the production process of acetic anhydride in Example 1, the amount of ozonized air introduced into the packed tower 2 during ozone treatment was 120 NL / H.
Acetic anhydride was produced in the same manner as in Example 1, except that The purity of the obtained purified acetic anhydride was 99.5%, the total content of dissolved ozone and the ozonized intermediate was 124 ppm in terms of ozone, and the content of the ozonized intermediate was 1 ppm.
It was 12 ppm. The diketene concentration was below the detection limit (2 ppm). The sulfuric acid test was carried out in the same manner as in Example 1 for the purified acetic anhydride obtained above and one obtained by subjecting it to heat treatment at 110 ° C. for 6 hours. Table 1 summarizes the measured values of acetic anhydride.
【００３０】比較例１ 実施例１と同様に、ケテン炉を通して酢酸の熱分解によ
って得られたケテンを酢酸に吸収させて粗製無水酢酸を
得、この粗製無水酢酸に対し、まずオゾン処理を行い、
次いで蒸留を行って製品無水酢酸を得た。オゾン処理
は、図１の装置において、オゾン濃度が２０ｇ／Ｎｍ3
のオゾン化空気を１５０ＮＬ／Ｈの速度で充填塔２の下
部から導入した。一方、粗製無水酢酸を充填塔２の上部
から６０００ｇ／Ｈで仕込み、オゾンと向流接触させて
処理した。次いで、充填塔２の下部から抜き取ったオゾ
ン処理後の無水酢酸を３０段のシーブトレイを有する蒸
留塔（内径４０ｍｍ、ガラス製）の上から１４段目に５
００ｇ／Ｈにて連続的に導入し、還流比５、塔頂圧力１
気圧にて運転を行った。濃縮された低沸物は塔頂におけ
る凝縮液より１００ｇ／Ｈ、精製された無水酢酸は上か
ら２６段目より蒸気サイドカットで３９６ｇ／Ｈの割合
で連続的に抜き取った。また、塔底より６ｇ／Ｈの割合
で高沸物を含む無水酢酸を連続的に抜き取った。得られ
た精製無水酢酸の純度は９９．６％、溶存オゾンとオゾ
ン化中間体との合計含有率はオゾン換算で３３ｐｐｍ、
このうち、溶存オゾンの含有率は検出限界（１０ｐｐ
ｍ）以下であった。また、ジケテン濃度は８ｐｐｍであ
った。上記で得られた精製無水酢酸およびこれを１１０
℃で６時間の加熱処理をしたものについて、実施例１と
同様にして硫着試験を行った。無水酢酸についての各測
定値をまとめて表１に示した。Comparative Example 1 In the same manner as in Example 1, ketene obtained by pyrolysis of acetic acid was absorbed into acetic acid through a ketene furnace to obtain crude acetic anhydride, and the crude acetic anhydride was first treated with ozone.
Then, distillation was performed to obtain a product acetic anhydride. In the ozone treatment, the ozone concentration was 20 g / Nm 3 in the apparatus shown in FIG.
Was introduced from the lower part of the packed tower 2 at a rate of 150 NL / H. On the other hand, crude acetic anhydride was charged from the upper part of the packed tower 2 at 6000 g / H, and treated by countercurrent contact with ozone. Then, the ozone-treated acetic anhydride extracted from the lower part of the packed tower 2 was placed in a 14th stage from the top of a distillation column (40 mm in diameter, made of glass) having 30 stages of sieve trays.
At a reflux ratio of 5 and a top pressure of 1
The operation was performed at atmospheric pressure. The concentrated low-boiling material was continuously withdrawn at a rate of 100 g / H from the condensate at the top of the column, and the purified acetic anhydride was continuously withdrawn at a rate of 396 g / H by steam side cut from the 26th stage from the top. Also, acetic anhydride containing a high-boiling substance was continuously extracted at a rate of 6 g / H from the bottom of the column. The purity of the obtained purified acetic anhydride was 99.6%, the total content of dissolved ozone and the ozonized intermediate was 33 ppm in terms of ozone,
Among these, the content of dissolved ozone is the detection limit (10 pp
m). The diketene concentration was 8 ppm. The purified acetic anhydride obtained above and 110
A heat treatment at 6 ° C. for 6 hours was subjected to a sulfuration test in the same manner as in Example 1. Table 1 summarizes the measured values of acetic anhydride.
【００３１】比較例２ 前記同様に得られた粗製無水酢酸を、３０段のシーブト
レイを有する蒸留塔（内径４０ｍｍ、ガラス製）の上か
ら１４段目に５００ｇ／Ｈにて連続的に導入し、還流比
５、塔頂圧力１００Ｔｏｒｒにて運転を行った。濃縮さ
れた低沸物は塔頂における凝縮液より１００ｇ／Ｈ、精
製された無水酢酸は上から２６段目より蒸気サイドカッ
トで３９４ｇ／Ｈの割合で連続的に抜き取った。得られ
た精製無水酢酸の純度は９９．６％、溶存オゾンとオゾ
ン化中間体との合計含有率はオゾン換算で６０ｐｐｍ、
このうち、溶存オゾンの含有率は検出限界（１０ｐｐ
ｍ）以下であった。また、ジケテン濃度は３ｐｐｍであ
った。上記で得られた精製無水酢酸およびこれを１１０
℃で６時間の加熱処理をしたものについて、実施例１と
同様にして硫着試験を行った。無水酢酸についての各測
定値をまとめて表１に示した。Comparative Example 2 The crude acetic anhydride obtained in the same manner as above was continuously introduced into a distillation column having a 30-stage sieve tray (inner diameter: 40 mm, made of glass) from the top to the 14th column at 500 g / H. The operation was performed at a reflux ratio of 5 and a top pressure of 100 Torr. The concentrated low-boiling substance was continuously withdrawn at a rate of 100 g / H from the condensate at the top of the column, and the purified acetic anhydride was continuously withdrawn at a rate of 394 g / H from the 26th stage by steam side cut. The purity of the obtained purified acetic anhydride was 99.6%, the total content of dissolved ozone and the ozonized intermediate was 60 ppm in terms of ozone,
Among these, the content of dissolved ozone is the detection limit (10 pp
m). The diketene concentration was 3 ppm. The purified acetic anhydride obtained above and 110
A heat treatment at 6 ° C. for 6 hours was subjected to a sulfuration test in the same manner as in Example 1. Table 1 summarizes the measured values of acetic anhydride.
【００３２】比較例３ 実施例１と同様に、ケテン炉を通して酢酸の熱分解によ
って得られたケテンを酢酸に吸収させて粗製無水酢酸を
得、この粗製無水酢酸に対し、オゾン処理を行った。オ
ゾン処理は、図１の装置において、オゾン濃度が２１ｇ
／Ｎｍ3のオゾン化空気を７５ＮＬ／Ｈバブリングしな
がら１時間接触させて処理した。得られた精製無水酢酸
の純度は８５．５％、溶存オゾンとオゾン化中間体との
合計含有率はオゾン換算で１５０ｐｐｍ、このうち、溶
存オゾンの含有率は２７ｐｐｍ、オゾン化中間体の含有
率は１２３ｐｐｍであった。上記で得られた精製無水酢
酸およびこれを１１０℃で６時間の加熱処理をしたもの
について、実施例１と同様にして硫着試験を行った。無
水酢酸についての各測定値をまとめて表１に示した。Comparative Example 3 In the same manner as in Example 1, ketene obtained by thermal decomposition of acetic acid was absorbed into acetic acid through a ketene furnace to obtain crude acetic anhydride, and the crude acetic anhydride was subjected to ozone treatment. In the ozone treatment, the ozone concentration was 21 g in the apparatus of FIG.
/ Nm 3 was contacted for 1 hour while bubbling at 75 NL / H. The purity of the obtained purified acetic anhydride was 85.5%, the total content of dissolved ozone and the ozonized intermediate was 150 ppm in terms of ozone, of which the content of dissolved ozone was 27 ppm and the content of ozonized intermediate. Was 123 ppm. The sulfuric acid test was carried out in the same manner as in Example 1 for the purified acetic anhydride obtained above and one obtained by subjecting it to heat treatment at 110 ° C. for 6 hours. Table 1 summarizes the measured values of acetic anhydride.
【００３３】[0033]
【表１】 [Table 1]
【００３４】表１より明らかなように、本発明の無水酢
酸（実施例１、２）は、加熱処理後に着色がなく、加熱
処理後の硫着試験（試験時間５分）のＡＰＨＡは低い値
であった。また、硫着試験の試験時間を１０時間、３０
時間、６０時間にした場合も、ＡＰＨＡは低い値であっ
た。これに対して、比較例１〜３の無水酢酸は、加熱処
理後に着色し、加熱処理後の硫着試験（試験時間５分）
のＡＰＨＡは高い値を示した。また、比較例１、２の無
水酢酸は、硫着試験の試験時間を６０時間にした場合、
試験時間５分の場合よりさらに高いＡＰＨＡの値を示し
た。As is clear from Table 1, the acetic anhydride of the present invention (Examples 1 and 2) has no coloring after the heat treatment, and has a low APHA in the sulfuration test (test time 5 minutes) after the heat treatment. Met. The test time of the sulfurization test was 10 hours, 30 hours.
Even when the time was set to 60 hours, the APHA was still low. On the other hand, the acetic anhydrides of Comparative Examples 1 to 3 were colored after the heat treatment, and the sulfurization test after the heat treatment (test time: 5 minutes)
APHA showed a high value. Further, the acetic anhydride of Comparative Examples 1 and 2 was obtained when the test time of the sulfurization test was set to 60 hours.
The value of APHA was higher than that of the test time of 5 minutes.
【００３５】[0035]
【発明の効果】本発明によれば、精製された無水酢酸で
あって、加熱等により着色等の品質問題が生じない無水
酢酸を提供し得る。本発明の無水酢酸は、高純度でかつ
色相等の品質が安定しているので、ポリアセタール、液
晶ポリマー製造用として、また有機薬品のアセチル化剤
等として広く用いることができる。According to the present invention, it is possible to provide purified acetic anhydride which does not cause quality problems such as coloring due to heating or the like. The acetic anhydride of the present invention has high purity and stable quality such as hue, so that it can be widely used for producing polyacetals and liquid crystal polymers, and as acetylating agents for organic chemicals.
【図１】本発明の無水酢酸の製造時にオゾン処理を行っ
たときの装置構成の一例を示す模式図である。FIG. 1 is a schematic diagram showing an example of an apparatus configuration when ozone treatment is performed during production of acetic anhydride of the present invention.
１ オゾン発生器 ２ 充填塔 1 ozone generator 2 packed tower
Claims (6)
を施した後の硫酸着色試験の値が１０ＡＰＨＡ以下であ
ることを特徴とする無水酢酸。1. An acetic anhydride characterized by having a sulfuric acid coloring test value of 10 APHA or less after a heat treatment at 80 to 120 ° C. for 5 hours or more.
上の無水酢酸であって、８０〜１２０℃、５時間以上の
加熱処理を施した後の硫酸着色試験の値が１０ＡＰＨＡ
以下であることを特徴とする無水酢酸。2. An acetic anhydride having a purity of 95% or more produced by ozone treatment and having a sulfuric acid coloring test value of 10 APHA after a heat treatment at 80 to 120 ° C. for 5 hours or more.
Acetic anhydride characterized by the following.
ン及びオゾン化中間体を含有していることを特徴とする
請求項１又は２記載の無水酢酸。3. The acetic anhydride according to claim 1, wherein the acetic anhydride before the heat treatment contains dissolved ozone and an ozonated intermediate.
含有率がオゾン換算で１５〜２００ｐｐｍであることを
特徴とする請求項３記載の無水酢酸。4. The acetic anhydride according to claim 3, wherein the total content of dissolved ozone and ozonized intermediate is 15 to 200 ppm in terms of ozone.
ｐｍであることを特徴とする請求項３又は４記載の無水
酢酸。5. The content of the ozonized intermediate is 5 to 200 p.
acetic acid anhydride according to claim 3 or 4,
上の無水酢酸に加熱処理を施して製造された無水酢酸。6. An acetic anhydride produced by subjecting acetic anhydride having a purity of 95% or more produced by ozone treatment to a heat treatment.
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|---|---|---|---|
| JP2001107959A JP2002037756A (en) | 2000-05-18 | 2001-04-06 | Acetic anhydride |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000146694 | 2000-05-18 | ||
| JP2000-146694 | 2000-05-18 | ||
| JP2001107959A JP2002037756A (en) | 2000-05-18 | 2001-04-06 | Acetic anhydride |
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| Publication Number | Publication Date |
|---|---|
| JP2002037756A true JP2002037756A (en) | 2002-02-06 |
Family
ID=26592143
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
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| Country | Link |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2011516452A (en) * | 2008-04-01 | 2011-05-26 | ビーエーエスエフ ソシエタス・ヨーロピア | Method of diluting the color of polyisocyanate with ozone-containing gas |
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|---|---|---|---|---|
| JPS60222439A (en) * | 1984-04-20 | 1985-11-07 | Daicel Chem Ind Ltd | Purification of crude acetic anhydride |
| JPS612052B2 (en) * | 1978-11-06 | 1986-01-22 | Daicel Chem | |
| JPH01211548A (en) * | 1987-12-23 | 1989-08-24 | Hoechst Celanese Corp | Purification of acetic acid by ozone |
| JPH0625071A (en) * | 1992-07-07 | 1994-02-01 | Daicel Chem Ind Ltd | Method for purifying acetic acid and / or acetic anhydride by ozone |
| JPH07324055A (en) * | 1994-04-04 | 1995-12-12 | Daicel Chem Ind Ltd | Production of acetic anhydride and acetic acid |
| JPH0820555A (en) * | 1994-07-06 | 1996-01-23 | Daicel Chem Ind Ltd | Production of acetic acid and/or acetic anhydride |
| JP2001226319A (en) * | 2000-02-17 | 2001-08-21 | Daicel Chem Ind Ltd | Purification method of crude acetic anhydride and production method of polyoxytetramethylene glycol using acetic anhydride |
| JP2001226480A (en) * | 2000-02-17 | 2001-08-21 | Daicel Chem Ind Ltd | Method for producing polyoxytetramethylene glycol |
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2001
- 2001-04-06 JP JP2001107959A patent/JP2002037756A/en active Pending
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS612052B2 (en) * | 1978-11-06 | 1986-01-22 | Daicel Chem | |
| JPS60222439A (en) * | 1984-04-20 | 1985-11-07 | Daicel Chem Ind Ltd | Purification of crude acetic anhydride |
| JPH01211548A (en) * | 1987-12-23 | 1989-08-24 | Hoechst Celanese Corp | Purification of acetic acid by ozone |
| JPH0625071A (en) * | 1992-07-07 | 1994-02-01 | Daicel Chem Ind Ltd | Method for purifying acetic acid and / or acetic anhydride by ozone |
| JPH07324055A (en) * | 1994-04-04 | 1995-12-12 | Daicel Chem Ind Ltd | Production of acetic anhydride and acetic acid |
| JPH0820555A (en) * | 1994-07-06 | 1996-01-23 | Daicel Chem Ind Ltd | Production of acetic acid and/or acetic anhydride |
| JP2001226319A (en) * | 2000-02-17 | 2001-08-21 | Daicel Chem Ind Ltd | Purification method of crude acetic anhydride and production method of polyoxytetramethylene glycol using acetic anhydride |
| JP2001226480A (en) * | 2000-02-17 | 2001-08-21 | Daicel Chem Ind Ltd | Method for producing polyoxytetramethylene glycol |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2011516452A (en) * | 2008-04-01 | 2011-05-26 | ビーエーエスエフ ソシエタス・ヨーロピア | Method of diluting the color of polyisocyanate with ozone-containing gas |
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