JPS6029733B2 - Method for controlling degree of polymerization of polyester - Google Patents

Description

【発明の詳細な説明】 本発明は鷹投機を有する反応槽でポリエステルを連続的
に製造する場合の重合度製御方法に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for controlling the degree of polymerization when polyester is continuously produced in a reactor having a hawk spectrometer.

以下、ポＩＪエチレンテレフタレートを製造する場合に
ついて説明すると、ジメチルテレフタレートとエチレン
グリコールのェステル交換反応、又はテレフタル酸とエ
チレングリコールのェステル化反応によって得られたビ
ス−３−ヒドロキシェチルテレフタレート又はその低重
合体を多段に設けた重合装置に連続的に供給し、高温高
真空下に渡洋を続けると最終の重合槽から目的とする重
合度のポリエチレンテレフタレートが連続的に得られる
。Hereinafter, to explain the case of manufacturing POIJ ethylene terephthalate, bis-3-hydroxyethyl terephthalate obtained by transesterification reaction of dimethyl terephthalate and ethylene glycol or esterification reaction of terephthalic acid and ethylene glycol or its lower weight When the combined product is continuously supplied to a multi-stage polymerization apparatus and continues to be transported across the ocean under high temperature and high vacuum conditions, polyethylene terephthalate having the desired degree of polymerization can be continuously obtained from the final polymerization tank.

このような連続重合装置の製品重合度を所望の一定値に
保つ方法としては多段に配した重合槽の各出口で重合度
とほぼ一次的関係を有する物性、例えば溶融粘度を検出
し、この検出値を一定にすべく各重合槽の真空度を制御
する方法が一般的に行なわれてきた。In order to maintain the degree of polymerization of products in such continuous polymerization equipment at a desired constant value, a physical property having an almost linear relationship with the degree of polymerization, such as melt viscosity, is detected at each outlet of the polymerization tank arranged in multiple stages, and this detection method is used. A method has generally been used to control the degree of vacuum in each polymerization tank in order to keep the value constant.

しかしながら、このような真空度を制御して重合度を一
定に保持する方法は、通常重合速度が比較的遅い場合に
は非常に有効なものであるが、重合体の自由表面積、自
由表面更新等を効果的に行うことによって従来より重合
速度をかなり遠くできるような重合槽が開発されてくる
と、上記真空制御方式のみによっては追随性が十分でな
く均一な重合度の製品を製造することが困難になってき
た。更に詳述すると本発明者らは速い重合速度を有する
重合装置を探索した際、蝿梓翼による反応物のかき上げ
および落下を行なって自由表面積の増大を計ったところ
、従来装置の２倍以上の重合速度が得られたにも拘らず
、製品重合度のバラッキが大きく、真空度の変化のみで
は到底制御出来ないことおよびこの際、重合速度は鯛梓
速度によってかなりの変化を示すことが判明した。However, this method of controlling the degree of vacuum to maintain a constant degree of polymerization is usually very effective when the polymerization rate is relatively slow; With the development of polymerization tanks that can increase the polymerization rate much further than conventional methods by effectively carrying out It's getting difficult. More specifically, when the present inventors searched for a polymerization device with a high polymerization rate, they measured an increase in the free surface area by scraping up and dropping the reactants using fly wings, and found that the free surface area was more than twice that of the conventional device. Although a polymerization rate of 100% was obtained, the degree of polymerization of the product varied widely, and it was found that it could not be controlled by changing the degree of vacuum alone, and that the polymerization rate varied considerably depending on the Taiazusa speed. did.

本発明はこのような問題に鑑み連続重合プ。In view of these problems, the present invention is directed to a continuous polymerization process.

セスの重合度制御を精度高く安定して行なわんとするも
ので、鷹梓機を有する重合槽を多段に配列したポリエス
テルの連続重合装置において、重合槽の出口で反応液の
溶融粘度を検出して該粘度と目標値とを比較し、その差
を一定域内にあるように重合槽の麓拝速度を増減して槽
内の流動状態を変化させ重合度の調整を行うようにした
ことを特徴とするものである。ここで、遺群速度の変更
は機械的手段、電気的手段等の如何なる手段によっても
よく、又蝿梓速度の変化の度合は予め定められたもので
あれば数段変速の切換式でも無段変速でもよい。The purpose of this system is to accurately and stably control the degree of polymerization in the process, and in a continuous polyester polymerization system with multiple polymerization tanks arranged in multiple stages, the melt viscosity of the reaction solution is detected at the outlet of the polymerization tank. The viscosity is compared with the target value, and the degree of polymerization is adjusted by increasing or decreasing the feeding speed of the polymerization tank to change the flow state in the tank so that the difference is within a certain range. That is. Here, the group speed may be changed by any means such as mechanical means or electrical means, and the degree of change in the fly azusa speed may be changed by a multi-speed switching method or a stepless method as long as it is predetermined. It may be variable speed.

本発明の制御方法をポリエチレンテレフタレートの場合
を例にとれば重合度が２０以上、望ましくは５０以上（
溶融粘度にして１００ポィズ以上）の範囲で単独又は真
空度制御と同時に行うことが好ましい。Taking the control method of the present invention in the case of polyethylene terephthalate as an example, the degree of polymerization is 20 or more, preferably 50 or more (
It is preferable to perform this alone or simultaneously with vacuum degree control within a range of 100 poise or more in terms of melt viscosity.

又この場合蝿梓翼回転数は数回転から数１０回転にする
のが好ましい。以下、本発明を図面によって説明する。
第１図は本発明の具体例を示す系統図である。図におい
て、１は多段式の連続重合装置の最終重合槽を示し、該
重合槽１にその入口２より供給された重合体は内設され
た瀦梓翼によって順次反応されながら出口３に向って送
られる。Further, in this case, it is preferable that the number of rotations of the fly azure blade is from several rotations to several tens of rotations. Hereinafter, the present invention will be explained with reference to the drawings.
FIG. 1 is a system diagram showing a specific example of the present invention. In the figure, 1 indicates the final polymerization tank of a multi-stage continuous polymerization apparatus, and the polymer supplied to the polymerization tank 1 from the inlet 2 is sequentially reacted by the built-in cascading blades and then flows toward the outlet 3. Sent.

重合槽１は第３〜４図に示す如く加熱ジャケット１１を
有する横型の重合槽本体１０に２つの縄梓軸１２，１３
が水平に並設されるとともに、該本体１川ま仕切板１８
で仕切られ多数の反応室２０を形成し、更に瀦拝軸１２
，１３には液面測定用の最終反応室を除いて各反応室２
０に板状の脇梓翼１４，１５が支持部村１６，１７を介
して軸万向に取付けられている。As shown in FIGS. 3 and 4, the polymerization tank 1 has a horizontal polymerization tank body 10 having a heating jacket 11 and two rope shafts 12 and 13.
are arranged horizontally in parallel, and the main body 1 river partition plate 18
partitioned to form a large number of reaction chambers 20, and furthermore, a worship shaft 12
, 13 contains each reaction chamber 2 except for the final reaction chamber for liquid level measurement.
Plate-shaped side azusa wings 14 and 15 are attached to the shaft 0 through support sections 16 and 17 in all directions of the axis.

この耀拝軸１２と１３はギア噛合方式により３：２の速
度比率で矢印の方向に回転し、又蝿梓翼１５は送り作用
を与えるため多少傾斜して設けられている。仕切板１８
には縄梓翼１５と対応する側に溢流口１９が設けられ礎
梓翼１５によって特上げられた際に重合物が次の室２０
１こ押出される如くなされている。各反応室２０では２
の女の櫨辞翼１４，１５が互いに噛み合いながら複雑な
運動を行うので重合物は均一に混合され、デットスベー
スの発生が防止される。重合物は縄梓翼１４，１５によ
って主として薄膜状に特上げられると共に特上げられた
重合物の大部分は回転に従って薄膜状に落下し、又液面
は複雑な曲面となって絶えず新しい表面が形成されるた
め重合が効果的に行なわれる。所定の重合度に反応され
た重合体は出口３から送液ポンプ４によって粘度計５に
送られ、ここで溶融粘度を計られたのち次の工程に送出
される。この溶融粘度の測定はバイパス通路を設けて行
ってもよい。この粘度計５で検出された重合体の溶融粘
度は制御装置６で温度補正後、設定値と比較されその差
に応じて又はその一定範囲を越えると可変減速機７に変
更指令を発し櫨拝翼の回転数を増減させる。この場合、
同時に真空度調節計８に信号を出し真空度調節弁９の関
度を変更するなどして重合槽１の真空度を制御するよう
にしてもよい。以上は２軸の蝿梓翼の例について説明し
たが、これに限定されるものでないことは言うまでもな
い。第２図は本発明を実施するに適した重合槽における
重合速度と縄拝速度との関係を一般的に示したものであ
る。The worship shafts 12 and 13 rotate in the direction of the arrow at a speed ratio of 3:2 by means of a gear engagement system, and the fly azure blades 15 are provided at a slight inclination to provide a feeding action. Partition plate 18
An overflow port 19 is provided on the side corresponding to the rope azusa wing 15, so that when the polymer is lifted up by the foundation azusa wing 15, it flows into the next chamber 20.
It is made so that one piece is extruded. In each reaction chamber 20, 2
Since the female cylindrical blades 14 and 15 perform complex movements while meshing with each other, the polymer is mixed uniformly and the generation of a dead base is prevented. The polymer is mainly lifted up in the form of a thin film by the rope azusa blades 14 and 15, and most of the lifted polymer falls down in the form of a thin film as it rotates, and the liquid surface becomes a complex curved surface, with new surfaces constantly being created. Because of this formation, polymerization is effectively carried out. The polymer reacted to a predetermined degree of polymerization is sent from the outlet 3 to the viscometer 5 by the liquid sending pump 4, where the melt viscosity is measured and then sent to the next step. This measurement of melt viscosity may be performed by providing a bypass passage. The melt viscosity of the polymer detected by the viscometer 5 is corrected by the temperature in the control device 6, and then compared with the set value. Depending on the difference, or if it exceeds a certain range, a change command is issued to the variable reducer 7. Increase or decrease the rotation speed of the wing. in this case,
At the same time, the vacuum level of the polymerization tank 1 may be controlled by sending a signal to the vacuum level regulator 8 and changing the function of the vacuum level regulating valve 9. Although an example of a two-axis fly wing has been described above, it goes without saying that the present invention is not limited to this. FIG. 2 generally shows the relationship between polymerization rate and rope speed in a polymerization tank suitable for carrying out the present invention.

一般に重合速度は温度、真空度、重合体自由表面積およ
び自由表面積更新作用により変化するが、鷹梓速度が大
きく関係するのは後の二者である。このような自由表面
積および自由表面積更新作用を蝿梓作用によって効果的
に実施すると、櫨群遊度の増減によって重合速度が従釆
に比して大きく変化するので、何らかの変動、例えば供
給量の変動によって重合度が変化した場合、瀦梓速度を
変更することにより流動状態を変え重合速度を非常に速
やかに調整でき、従って重合度の変化中が極めて４・さ
くなり均一な製品重合体を得ることが可能となる。Generally, the polymerization rate changes depending on the temperature, degree of vacuum, free surface area of the polymer, and free surface area renewal effect, but the latter two are largely related to the Takaazusa rate. If such a free surface area and free surface area renewal action is effectively carried out by the fly azure action, the polymerization rate will change greatly compared to the subordinate method due to an increase or decrease in the free surface area, so some fluctuations, such as fluctuations in the supply amount, will When the degree of polymerization changes due to the change in the degree of polymerization, changing the flow rate can change the flow state and adjust the polymerization rate very quickly. Therefore, the change in the degree of polymerization is extremely slow and a uniform product polymer can be obtained. becomes possible.

実施例 １ ジメチルテレフタレート１０唯部、エチレングリコール
７６部、酢酸亜鉛０．０２郡、三酸化アンチモン０．０
４部の割合で通常の連続ェステル交換反応装置に仕込み
連続してェステル交換を行い、更に連続初期重合槽を通
して得られた極限粘度０．４０（オルソクロルフヱノ−
ル溶液中３５ｑｏにて測定した値）の重合物を第１図お
よび第３〜４図に示す如き最終重合槽に２００ｋｇ／Ｈ
ｒの流量で供給した。Example 1 10 parts of dimethyl terephthalate, 76 parts of ethylene glycol, 0.02 parts of zinc acetate, 0.0 parts of antimony trioxide
4 parts of the mixture was charged into a conventional continuous transesterification reactor for continuous transesterification, and then passed through a continuous initial polymerization tank to obtain an intrinsic viscosity of 0.40 (orthochlorofluoroethylene).
200 kg/h of the polymer (measured at 35 qo in the solution) was transferred to the final polymerization tank as shown in Figures 1 and 3-4.
It was supplied at a flow rate of r.

重合槽内の温度は入口側２７９０〜２８０００、出口側
２８０ｑｏ〜２８５午Ｃに保たれており平均真空度は１
．０〜２．０肌Ｈｇａ広に保持され、低速側の蝿洋軸が
毎分３回転の速度を基準として４〜１２回転の間で連続
可変するように損梓翼を回転せしめた。そして重合物の
出口極限粘度の目標設定値は〔り〕＝０．６５とし、〔
り〕＝０．６５±０．０１０の範囲外を制御作動域とし
た。このようにして１ケ月間運転して得られた重合物の
出口極限粘度の変動は〔り〕＝０．６５±０．０２２で
あった。The temperature inside the polymerization tank is maintained at 2,790 to 28,000 degrees Celsius on the inlet side and 280 degrees Celsius to 285 degrees Celsius on the outlet side, and the average degree of vacuum is 1.
．． The rotor blade was rotated so that the rotary shaft on the low speed side was continuously varied between 4 and 12 revolutions with a speed of 3 revolutions per minute as a reference. The target setting value of the exit limiting viscosity of the polymer is [ri]=0.65, and [
The area outside the range of =0.65±0.010 was defined as the control operation range. The variation in exit limiting viscosity of the polymer obtained by operating in this way for one month was 0.65±0.022.

実施例 ２ 実施例１と同様な条件で、更に真空度を０．５〜１仇肋
Ｈｇａ戊の範囲で同時にコントロールできるようにして
反応を行い。Example 2 The reaction was carried out under the same conditions as in Example 1, with the degree of vacuum simultaneously controllable within the range of 0.5 to 1 ft Hga.

３ケ月運転したところ、得られた重合物の出口極限粘度
の変動は〔刀〕＝０．６５土０．０２０であった。After operating for 3 months, the variation in exit limiting viscosity of the obtained polymer was 0.65 = 0.020.

比較例 低速側の渡洋速度をＳｒ．ｐ．ｍ．の一定回転にした以
外は実施例２と同じ条件で１５日間運転したところ、重
合物の出口極限粘度の変動は〔り〕：０．６５十０．０
５１であった。Comparative example The crossing speed on the low speed side was set to Sr. p. m. When the operation was carried out for 15 days under the same conditions as in Example 2 except that the rotation was constant, the variation in the exit limiting viscosity of the polymer was: 0.65 - 0.0
It was 51.

このように本発明によればポリエステルの連続反応装置
での重合度制御を極めて短時間で行うことができると共
に連続して品質の安定した均一な製品を得ることが可能
となりその効果は非常に大である。As described above, according to the present invention, it is possible to control the degree of polymerization in a continuous polyester reaction apparatus in an extremely short time, and it is also possible to continuously obtain a uniform product with stable quality, which has a very large effect. It is.

【図面の簡単な説明】[Brief explanation of drawings]

第１図は本発明を実施するために適した系統図、第２図
は本発明を説明するための縄拝速度と重合速度の関係図
、第３図は第１図に示す最終重合槽の一部断面を含む側
面図、第４図は第３図のＡ−Ａ断面矢視図である。 １は最終重合槽、４はポンプ、５は粘度計、６は制御装
置、７は可変減速機、１２，１３は礎梓軸、１４，１５
は雌梓翼、１８は仕切板、２０は反応室。 第ー図 弊２図 沖る鶴 死４鶴Figure 1 is a system diagram suitable for carrying out the present invention, Figure 2 is a diagram showing the relationship between rope speed and polymerization rate to explain the present invention, and Figure 3 is a diagram of the final polymerization tank shown in Figure 1. A side view including a partial cross section, FIG. 4 is a cross-sectional view taken along the line AA in FIG. 3. 1 is the final polymerization tank, 4 is the pump, 5 is the viscometer, 6 is the control device, 7 is the variable speed reducer, 12 and 13 are the base shafts, 14 and 15
18 is a partition plate, and 20 is a reaction chamber. Fig. 2. Crane death 4.

Claims (1)

【特許請求の範囲】[Claims] １ 撹拌機を有する重合槽を多段に配列したポリエステ
ルの連続重合装置において、重合槽の出口で反応液の溶
融粘度を検出して該粘度と目標値とを比較し、その差を
一定域内にあるように重合槽の撹拌速度を増減して槽内
の流動状態を変化させ重合度の調整を行うようにしたこ
とを特徴とするポリエステルの重合度製御方法。1. In a continuous polyester polymerization device in which polymerization tanks each having a stirrer are arranged in multiple stages, the melt viscosity of the reaction solution is detected at the exit of the polymerization tank, the viscosity is compared with a target value, and the difference is determined to be within a certain range. A method for controlling the degree of polymerization of polyester, characterized in that the degree of polymerization is adjusted by increasing or decreasing the stirring speed of the polymerization tank to change the fluid state in the tank.