JPH0665659B2 - Process for producing 2,6-naphthalenedicarboxylic acid - Google Patents
Process for producing 2,6-naphthalenedicarboxylic acidInfo
- Publication number
- JPH0665659B2 JPH0665659B2 JP60199537A JP19953785A JPH0665659B2 JP H0665659 B2 JPH0665659 B2 JP H0665659B2 JP 60199537 A JP60199537 A JP 60199537A JP 19953785 A JP19953785 A JP 19953785A JP H0665659 B2 JPH0665659 B2 JP H0665659B2
- Authority
- JP
- Japan
- Prior art keywords
- naphthalenedicarboxylic acid
- producing
- reaction
- acid
- present
- 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 - Fee Related
Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/50—Improvements relating to the production of bulk chemicals
- Y02P20/52—Improvements relating to the production of bulk chemicals using catalysts, e.g. selective catalysts
Landscapes
- Catalysts (AREA)
- 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】 産業上の利用分野 この発明は、ポリエステル等の高分子材料の原料として
有用な2,6−ナフタレンジカルボン酸の製造方法に関す
る。TECHNICAL FIELD The present invention relates to a method for producing 2,6-naphthalenedicarboxylic acid useful as a raw material for a polymer material such as polyester.
従来の技術 2,6−ナフタレンジカルボン酸は、2,6−ジメチルナフタ
レンを酢酸のごとき低級脂肪酸溶媒中で、コバルトのご
とき重金属と臭素を含む触媒系を用いて、分子状酸素に
より酸化すれば製造できることが公知である。しかしな
がら、ジメチルナフタレンには物性の近似した10種の異
性体があって、これらの混合物から2,6−体のみを取得
するには若干複雑な操作を必要とする。したがって、2,
6−ナフタレンジカルボン酸をこの方法によって製造す
ると原価が高くなる。Prior art 2,6-naphthalenedicarboxylic acid is produced by oxidizing 2,6-dimethylnaphthalene with molecular oxygen in a lower fatty acid solvent such as acetic acid using a catalyst system containing a heavy metal such as cobalt and bromine. It is known that this can be done. However, dimethylnaphthalene has 10 isomers with similar physical properties, and a slightly complicated operation is required to obtain only the 2,6-isomer from the mixture. Therefore, 2,
The cost of producing 6-naphthalenedicarboxylic acid by this method is high.
これに対して、２−メチルナフタレンをアセチル化する
と２−メチル−６−アセチルナフタレンが比較的容易に
得られる。しかし、２−メチル−６−アセチルナフタレ
ンの酸化、特に分子状酸素による液相酸化反応について
は、従来あまり研究が行なわれておらず、2,6−ナフタ
レンジカルボン酸を製造するための工業的方法になり得
るかどうか不明であった。On the other hand, when 2-methylnaphthalene is acetylated, 2-methyl-6-acetylnaphthalene can be obtained relatively easily. However, the oxidation of 2-methyl-6-acetylnaphthalene, particularly the liquid-phase oxidation reaction by molecular oxygen, has not been studied so far, and an industrial method for producing 2,6-naphthalenedicarboxylic acid It was unclear whether it could be.
発明が解決しようとする問題点 この発明は、２−メチル−６−アセチルナフタレンを原
料として2,6−ナフタレンジカルボン酸を高収率で製造
する方法を提供しようとするものである。Problems to be Solved by the Invention The present invention is intended to provide a method for producing 2,6-naphthalenedicarboxylic acid in high yield using 2-methyl-6-acetylnaphthalene as a raw material.
問題点を解決するための手段 この発明は２−メチル−６−アセチルナフタレンの分子
状酸素による酸化反応を種々検討した結果、低級脂肪酸
溶媒中でコバルトのごとき重金属及び臭素を含む触媒系
を用いると、収率良く2,6−ナフタレンジカルボン酸が
生成するという発見に基づくものである。Means for Solving the Problems As a result of various studies on the oxidation reaction of 2-methyl-6-acetylnaphthalene with molecular oxygen, the present invention shows that a catalyst system containing a heavy metal such as cobalt and bromine is used in a lower fatty acid solvent. It is based on the discovery that 2,6-naphthalenedicarboxylic acid is produced in good yield.
アセチル基は酸化反応に対してメチル基より抵抗性があ
り、また、ナフタレン環はベンゼン環に比較し酸化分解
を受け易い。したがって、酸化反応条件を単に周知のパ
ラキシレンの酸化等と同様に設定したのみでは、６−ア
セチル−２−ナフトエ酸等の中間体、あるいはトリメリ
ット酸等の分解生成物の生成量が多く、高純度の2,6−
ナフタレンジカルボン酸は得られないことがわかった。
特に６−アセチル−２−ナフトエ酸等のモノカルボン酸
は一旦生成すると除去し難く、これが残存すると2,6−
ナフタレンジカルボン酸を用いる重縮合反応等に悪影響
をおよぼすのでその生成量を最低限に抑制しておく必要
がある。The acetyl group is more resistant to oxidation reaction than the methyl group, and the naphthalene ring is more susceptible to oxidative decomposition than the benzene ring. Therefore, if the oxidation reaction conditions are simply set in the same manner as the well-known oxidation of para-xylene, etc., the production amount of the intermediate such as 6-acetyl-2-naphthoic acid or the decomposition product such as trimellitic acid is large, Highly pure 2,6-
It was found that naphthalenedicarboxylic acid could not be obtained.
In particular, monocarboxylic acids such as 6-acetyl-2-naphthoic acid are difficult to remove once they are formed, and if they remain 2,6-
Since it adversely affects the polycondensation reaction using naphthalenedicarboxylic acid, it is necessary to suppress the amount of the formation to the minimum.
このためこの発明者等はさらに詳細に酸化反応の検討を
続けた結果、反応を二段階で行なうことにより、副生物
の生成量を減じ、収率良く2,6−ナフタレンジカルボン
酸を得る方法を開発することに成功し、この発明に到達
したものである。Therefore, as a result of continuing the study of the oxidation reaction in more detail, the inventors of the present invention conducted a reaction in two steps to reduce the amount of by-products produced and to obtain a method for obtaining 2,6-naphthalenedicarboxylic acid in good yield. It succeeded in developing and reached this invention.
すなわち、この発明の構成は２−メチル−６−アセチル
ナフタレンを、低級脂肪酸溶媒中、コバルト、マンガン
および臭素を含む触媒の存在下で、分子状酸素により２
段階に酸化する、2,6−ナフタレンジカルボン酸の製造
法であって、第１段階の反応温度を100〜250℃、第２段
階の反応温度を250〜290℃で行なう2,6−ナフタレンジ
カルボン酸の製造法である。That is, the constitution of the present invention comprises adding 2-methyl-6-acetylnaphthalene to molecular oxygen in the presence of a catalyst containing cobalt, manganese, and bromine in a lower fatty acid solvent.
A method for producing 2,6-naphthalenedicarboxylic acid, which is oxidized in two stages, wherein the reaction temperature in the first stage is 100 to 250 ° C and the reaction temperature in the second stage is 250 to 290 ° C. It is a method of producing an acid.
以下にこの発明の方法につき詳細に説明する。The method of the present invention will be described in detail below.
この発明の方法において、溶媒として使用する低級脂肪
酸としては、特に酢酸が好ましい。溶媒の使用量は原料
である２−メチル−６−アセチルナフタレンに対し重量
比で１ないし200倍程度、より好ましくは５ないし30倍
程度である。In the method of the present invention, acetic acid is particularly preferable as the lower fatty acid used as the solvent. The amount of the solvent used is about 1 to 200 times, and more preferably about 5 to 30 times the weight ratio of 2-methyl-6-acetylnaphthalene as a raw material.
触媒はコバルト、マンガンおよび臭素を含む系がよく、
これにセリウム等を併用してもよい。触媒は反応系にお
いて可溶であることが好ましく、用いられる化合物とし
ては、例えば、酢酸コバルト、ナフテン酸コバルト、臭
化コバルト、臭化ナトリウム、臭化水素、臭化ベンジ
ル、酢酸マンガン、硝酸セリウム等があげられる。触媒
の濃度は全系に対し、コバルト、マンガン、臭素とを50
ppmないし５％、より好ましくは500ないし5000ppm程度
である。The catalyst is preferably a system containing cobalt, manganese and bromine,
Cerium or the like may be used in combination with this. The catalyst is preferably soluble in the reaction system, and examples of the compound used include cobalt acetate, cobalt naphthenate, cobalt bromide, sodium bromide, hydrogen bromide, benzyl bromide, manganese acetate, cerium nitrate, etc. Can be given. The catalyst concentration is 50% cobalt, manganese, and bromine for all systems.
ppm to 5%, more preferably about 500 to 5000 ppm.
この発明方法の特徴とするところは酸化反応の温度を変
えて二段階に実施する点にある。すなわち、第一段階で
はナフタレン環の分解が起こり難い比較的低温で酸化を
行なうが、この条件ではある程度のアセチル基が酸化さ
れずに残存する。そこで第二段階として温度を高めて再
び酸化を行なうと、アセチル基の酸化が完結する一方、
より安定なナフタレンカルボン酸のナフタレン環の分解
は少ない。したがって、副生物の量を減じることができ
る。The feature of the method of the present invention is that the oxidation reaction is carried out in two steps by changing the temperature. That is, in the first step, the naphthalene ring is decomposed at a relatively low temperature at which decomposition is unlikely to occur, but under these conditions, some acetyl groups remain without being oxidized. Therefore, when the temperature is raised and oxidation is carried out again as the second step, while the oxidation of the acetyl group is completed,
More stable decomposition of naphthalene ring of naphthalenecarboxylic acid is less. Therefore, the amount of by-products can be reduced.
第一段の反応温度は100℃ないし250℃、より好ましくは
160℃ないし200℃の間で選ばれる。第二段は250℃ない
し290℃、より好ましくは260℃ないし280℃の間で選ば
れる。この反応温度が高温にすぎると溶媒の分解も激し
い。The reaction temperature in the first step is 100 ° C to 250 ° C, more preferably
It is selected between 160 ° C and 200 ° C. The second stage is selected between 250 ° C and 290 ° C, more preferably between 260 ° C and 280 ° C. If the reaction temperature is too high, the decomposition of the solvent will be severe.
反応圧力は反応温度にしたがって定められる。100kg／c
m2程度以下で適当な酸素分圧が得られるように定めれば
よい。The reaction pressure is set according to the reaction temperature. 100 kg / c
It may be set so that an appropriate oxygen partial pressure can be obtained at about m 2 or less.
酸化ガスとしては空気がそのまま用いられるが、爆発組
成領域に反応条件が入るおそれのある場合は適宜不活性
ガス希釈して用いればよい。Air is used as the oxidizing gas as it is, but if there is a possibility that reaction conditions may enter the explosive composition region, it may be appropriately diluted with an inert gas before use.
この発明の方法は回分式、半連続式、連続式いずれの方
法においても実施することができる。生成した2,6−ナ
フタレンジカルボン酸は、反応液を冷却して析出させ、
濾過、遠心分離等により分散して取得できる。The method of the present invention can be implemented in any of batch, semi-continuous and continuous methods. The generated 2,6-naphthalenedicarboxylic acid is cooled by precipitating the reaction solution,
It can be obtained by dispersion by filtration, centrifugation or the like.
実施例 次に実施例を挙げてこの発明を更に具体的に説明する
が、この発明はその要旨を逸脱しない限り、以下の実施
例に限定されるものではない。EXAMPLES Next, the present invention will be described more specifically by way of examples, but the present invention is not limited to the following examples without departing from the gist thereof.
実施例１〜２、比較例１〜４ 200mlのオートクレーブに所定量の２−メチル−６−ア
セチルナフタレン、酢酸70ml、触媒として酢酸コバル
ト、酢酸マンガン、臭化ナトリウムを各々全系に対しコ
バルトとして760ppm、マンガンとして720ppm、臭素とし
て1200ppmとなるように仕込み、撹拌しながら酸化ガス
を吹込んで反応を行なった。第一段反応が終了後、オー
トクレーブの内容物はそのまま、反応条件のみを第二段
の所定値に変更してひきつづき酸化反応を続行した。Examples 1 and 2 and Comparative Examples 1 to 4 A predetermined amount of 2-methyl-6-acetylnaphthalene, 70 ml of acetic acid, cobalt acetate, manganese acetate and sodium bromide as catalysts were added to a 200 ml autoclave, and 760 ppm of cobalt was added to the whole system. , Manganese was 720 ppm and bromine was 1200 ppm, and the reaction was carried out by blowing an oxidizing gas while stirring. After the completion of the first-step reaction, the content of the autoclave was left unchanged, and only the reaction conditions were changed to the predetermined values in the second step, and the oxidation reaction was continued.
これらの反応の具体的条件および結果を下記の表に示
す。The specific conditions and results of these reactions are shown in the table below.
発明の効果 以上、説明したように、この発明によれば、純度の高い
2,6−ナフタレンジカルボン酸を比較的簡単に、かつ、
収率よく製造することができる。 Effects of the Invention As described above, according to the present invention, the purity is high.
2,6-naphthalenedicarboxylic acid is relatively easy, and
It can be manufactured in high yield.
Claims (1)
低級脂肪酸溶媒中、コバルト、マンガンおよび臭素を含
む触媒の存在下で、分子状酸素により２段階に酸化す
る、2,6−ナフタレンジカルボン酸の製造法であって、
第１段階の反応温度を100〜250℃、第２段階の反応温度
を250〜290℃で行なうことを特徴とする2,6−ナフタレ
ンジカルボン酸の製造法。1. 2-Methyl-6-acetylnaphthalene,
A process for producing 2,6-naphthalenedicarboxylic acid, which comprises two-step oxidation with molecular oxygen in the presence of a catalyst containing cobalt, manganese and bromine in a lower fatty acid solvent,
A method for producing 2,6-naphthalenedicarboxylic acid, characterized in that the reaction temperature in the first step is 100 to 250 ° C and the reaction temperature in the second step is 250 to 290 ° C.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60199537A JPH0665659B2 (en) | 1985-09-11 | 1985-09-11 | Process for producing 2,6-naphthalenedicarboxylic acid |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60199537A JPH0665659B2 (en) | 1985-09-11 | 1985-09-11 | Process for producing 2,6-naphthalenedicarboxylic acid |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6261947A JPS6261947A (en) | 1987-03-18 |
| JPH0665659B2 true JPH0665659B2 (en) | 1994-08-24 |
Family
ID=16409481
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP60199537A Expired - Fee Related JPH0665659B2 (en) | 1985-09-11 | 1985-09-11 | Process for producing 2,6-naphthalenedicarboxylic acid |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0665659B2 (en) |
-
1985
- 1985-09-11 JP JP60199537A patent/JPH0665659B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6261947A (en) | 1987-03-18 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |