JPH0532489B2

JPH0532489B2 -

Info

Publication number: JPH0532489B2
Application number: JP59218606A
Authority: JP
Inventors: Atsushi Yamaguchi; Eiji Sato
Original assignee: Asahi Chemical Industry Co Ltd
Current assignee: Asahi Chemical Industry Co Ltd
Priority date: 1984-10-19
Filing date: 1984-10-19
Publication date: 1993-05-17
Also published as: JPS61102413A

Description

【発明の詳細な説明】[Detailed description of the invention]

産業上の利用分野本発明は、ポリーパラフエニレンテレフタルア
ミド（以下、PPTAと略称する）系繊維の製造方
法に関する。更に詳しくは、改良された機械的性
質を持つPPTA系繊維を、工業的に有利な硫酸水
溶液の凝固浴を用いて製造する紡糸法に関するも
のである。従来の技術芳香族ジアミンと芳香族ジカルボン酸、及び／
又は芳香族アミノカルボン酸から全芳香族ポリア
ミドが誘導されることは公知であり、またこれら
芳香族ポリアミドから繊維が得られることも既に
公知である。さらに、かかる芳香族ポリアミドの
うち特に、PPTA系ポリマーから、その剛直な分
子構造から期待される通り、高い融点、優れた結
晶性、高い強度、高いヤング率等の好ましい物性
を有する繊維が得られることも既に知られてい
る。例えば、特開昭47−39458号報によれば、少な
くとも98％以上の濃度の濃硫酸に溶解したPPTA
系ポリマーの光学的異方性を示す溶液を、オリフ
イスを通して、不活性な非凝固性流体中に押し出
し、次いで凝固浴中を通すことによつて、好まし
い機械的性質を有する繊維が得られることが開示
されている。しかしながら、かかる方法においては、凝固浴
中の凝固液と走行する糸条との摩擦抵抗により、
糸条に大きな引き取り張力、即ち紡糸張力がかか
る。この紡糸張力は、凝固液の硫酸濃度を高める
と溶液の粘度、比重の増加で増大するため、紡糸
張力の低い、即ち硫酸濃度の低い凝固液を用いた
場合は優れた機械的性質を有する繊維を与える
が、硫酸濃度の上昇に伴つて、得られる繊維の強
度・伸度が著しく低下する。従つて、溶媒として
用いる硫酸の回収面において工業的に有利な10％
以上の硫酸水溶液を一次凝固液として用いて機械
的性質に優れたPPTA繊維を得ることは困難であ
つた。かかる方法に対し、紡糸張力を低減する方法と
して、凝固浴下部に特定のスピンチユーブ（細
孔）を設け、糸条と凝固液を同時に落下させつつ
紡糸する方法（特開昭53−78320号報）が提案さ
れたが、10％以上の硫酸水溶液を用いては、張力
を充分に低減しうるには至らず、高い繊維性能を
得るには至つていない。更に、凝固液と糸条の速度差によつて生じる摩
擦抵抗を低減するために、凝固浴液を加圧し、ス
ピンチユーブからの凝固液速を加速する方法（特
開昭53−78321号報）、或いは、スピンチユーブを
通して落下する糸条と凝固液流に、複数の小径ノ
ズル或いはスリツトから噴出させた別の凝固液
を、糸条の引き取り方向に当てて加速する方法
（特開昭56−128312号報）が提案された。この方法により、一次凝固液に硫酸水溶液を用
いても、凝固液を加速することによつて、見掛け
上、紡糸張力を低減することは可能であるが、ス
ピンチユーブ以降の自由落下域においては、重力
加速度の働きにより落下液の速度が逐次高まるた
め、凝固途中の糸条に抵抗覆歴を与え、高次構造
の破壊を引き起こす結果、強度及び伸度の低下を
招き、充分に高い性能を有する繊維は得られな
い。特に10％以上の硫酸水溶液を一次凝固液に用い
た場合は、凝固がより不完全となり、見掛けの張
力を低下させても凝固途中の糸条への抵抗が変化
することで糸条の結晶配向及び糸条の高次破壊が
生じる結果、強度、伸度共に低い繊維しか得るこ
とが出来ない。 PPTA系繊維の実用性能上、高い強度は勿論の
ことながら、高い伸度を合わせ持つことが重要で
あることは周知のとおりであり、特にタイヤコー
ドとして使用される繊維では、耐疲労特性上極め
て重要である。発明が解決しようとする問題点本発明者らは、かかる点に鑑み、高い強度は勿
論のこと高い伸度を有するPPTA繊維を、工業的
に有利な10％以上の硫酸水溶液を一次凝固液とし
て用い製造する方法について、PPTA系ポリマー
の濃硫酸溶液（以下、単にドープと略称する）か
らの凝固過程における系条の形成と、得られる
PPTA繊維の物性及び構造とを対応させつつ長時
間の研究を続けてきた。その結果、ドープを非凝
固性の流体層を通して凝固浴に導く湿式紡糸法に
おいて、ある特定の条件を満たす流管中で凝固さ
せた場合においてのみ、高強度かつ高伸度の機械
的性質に優れたPPTA系繊維が得られることを見
い出し、更に鋭意検討した結果本発明を完成した
ものである。本発明の目的は、強度および伸度の改良された
高性能のPPTA系繊維を工業的に有利な10％以上
の硫酸水溶液を一次凝固液に用い製造する方法を
提供するにある。問題点を解決するための手段本発明に係るPPTA系繊維の製造方法は、溶媒
100ml当り、少なくとも30ｇのポリーパラフエニ
レンテレフタルアミド系ポリマーを含む98.0〜
100.2％硫酸の光学的異方性を示す溶液を空気又
は非凝固性の流体層を通して少なくも10％硫酸水
溶液の一次凝固液に導き、次いで凝固浴下部に設
けられた細管中に糸条を導き走行させたのち、該
糸条を洗浄、乾燥等の仕上げ工程に供する湿式紡
糸法により繊維を製造するにあたり、該細管は長
さと内径の比が0.5以上であつて、かつ、該細管
の下端部が挿入される様に流管を設置し、その際
該流管は細管の断面積の２倍以上の断面積になる
ような内径、及び走行する糸条が10mm秒以上滞留
出来るような長さを有し、かつ、流管中の凝固液
速度が糸条速度の少なくとも80％になるように、
該細管の下端面の上部から二次凝固液を供給する
ことを特徴とする。本発明において、PPTA系ポリマーとは、ポリ
ーパラフエニレンテレフタルアミドならびにその
INDUSTRIAL APPLICATION FIELD The present invention relates to a method for producing polyparaphenylene terephthalamide (hereinafter abbreviated as PPTA) fiber. More specifically, the present invention relates to a spinning method for producing PPTA fibers with improved mechanical properties using an industrially advantageous coagulation bath of an aqueous sulfuric acid solution. Conventional technology Aromatic diamine, aromatic dicarboxylic acid, and/or
It is also known that fully aromatic polyamides can be derived from aromatic aminocarboxylic acids, and that fibers can be obtained from these aromatic polyamides. Furthermore, among such aromatic polyamides, fibers having favorable physical properties such as high melting point, excellent crystallinity, high strength, and high Young's modulus can be obtained from PPTA-based polymers, as expected from their rigid molecular structure. This is already known. For example, according to JP-A-47-39458, PPTA dissolved in concentrated sulfuric acid with a concentration of at least 98%
Fibers with favorable mechanical properties can be obtained by extruding optically anisotropic solutions of polymers through an orifice into an inert, non-coagulable fluid and then through a coagulation bath. Disclosed. However, in this method, due to the frictional resistance between the coagulating liquid in the coagulating bath and the running yarn,
A large take-up tension, ie, spinning tension, is applied to the yarn. This spinning tension increases as the sulfuric acid concentration of the coagulation solution increases, as the viscosity and specific gravity of the solution increase. Therefore, when a coagulation solution with a low spinning tension, that is, a low sulfuric acid concentration, is used, fibers with excellent mechanical properties can be obtained. However, as the sulfuric acid concentration increases, the strength and elongation of the resulting fibers decrease significantly. Therefore, 10% is industrially advantageous in terms of recovering sulfuric acid used as a solvent.
It was difficult to obtain PPTA fibers with excellent mechanical properties using the above sulfuric acid aqueous solution as the primary coagulation liquid. In contrast to this method, as a method to reduce the spinning tension, a method is proposed in which a specific spin tube (pore) is provided at the bottom of the coagulation bath and the yarn and coagulation liquid are simultaneously dropped while spinning (JP-A-53-78320). ) has been proposed, but using a 10% or more sulfuric acid aqueous solution has not been able to sufficiently reduce the tension and have not resulted in high fiber performance. Furthermore, in order to reduce the frictional resistance caused by the speed difference between the coagulating liquid and the yarn, there is a method of pressurizing the coagulating bath liquid and accelerating the speed of the coagulating liquid from the spin tube (Japanese Patent Application Laid-open No. 78321/1983). Alternatively, a method of accelerating the yarn and coagulating liquid falling through a spin tube by applying another coagulating liquid jetted from a plurality of small diameter nozzles or slits in the direction of yarn take-up (Japanese Patent Laid-Open No. 56-128312) issue) was proposed. With this method, even if a sulfuric acid aqueous solution is used as the primary coagulation liquid, it is possible to reduce the spinning tension by accelerating the coagulation liquid, but in the free fall region after the spin tube, The velocity of the falling liquid increases gradually due to the action of gravitational acceleration, which gives the yarn during solidification a resistance history and causes the destruction of the higher-order structure, resulting in a decrease in strength and elongation, so it has sufficiently high performance. No fibers are obtained. In particular, when a 10% or more sulfuric acid aqueous solution is used as the primary coagulation liquid, coagulation becomes more incomplete, and even if the apparent tension is reduced, the resistance to the yarn during coagulation changes, resulting in the crystal orientation of the yarn. As a result of high-order destruction of the yarn, only fibers with low strength and elongation can be obtained. It is well known that for the practical performance of PPTA fibers, it is important to have not only high strength but also high elongation. Especially for fibers used as tire cords, they have extremely high fatigue resistance. is important. Problems to be Solved by the Invention In view of the above, the present inventors have developed PPTA fibers having not only high strength but also high elongation by using an industrially advantageous 10% or more sulfuric acid aqueous solution as a primary coagulation liquid. Regarding the manufacturing method using PPTA-based polymers, the process involves the formation of a PPTA-based polymer in the coagulation process from a concentrated sulfuric acid solution (hereinafter simply referred to as dope), and the resulting
We have continued to conduct long-term research while matching the physical properties and structure of PPTA fibers. As a result, in the wet spinning method in which the dope is introduced into a coagulation bath through a non-coagulable fluid layer, excellent mechanical properties such as high strength and high elongation can only be achieved when the dope is coagulated in a flow tube that meets certain conditions. The inventors discovered that PPTA fibers can be obtained, and as a result of further intensive study, the present invention was completed. An object of the present invention is to provide a method for producing high-performance PPTA fibers with improved strength and elongation using an industrially advantageous 10% or more sulfuric acid aqueous solution as the primary coagulation liquid. Means for Solving the Problems The method for producing PPTA fibers according to the present invention includes
Contains at least 30g of polyparaphenylene terephthalamide polymer per 100ml.
A solution exhibiting optical anisotropy of 100.2% sulfuric acid is introduced through air or a non-coagulable fluid layer to a primary coagulation solution of at least 10% sulfuric acid aqueous solution, and then the thread is introduced into a capillary provided at the bottom of the coagulation bath. After running, the yarn is subjected to finishing processes such as washing and drying to produce fibers by a wet spinning method. A flow tube is installed so that the flow tube is inserted, and at this time, the flow tube has an inner diameter that has a cross-sectional area that is at least twice that of the thin tube, and a length that allows the running yarn to stay there for at least 10 mm seconds. and such that the coagulating liquid velocity in the flow tube is at least 80% of the yarn velocity,
It is characterized in that the secondary coagulation liquid is supplied from the upper part of the lower end surface of the thin tube. In the present invention, PPTA-based polymer refers to polyparaphenylene terephthalamide and its

【式】単位又は／及び[Formula] Unit or/and

【式】単位10モル％以下が、それぞれ他の芳香族ジアミノ残基又は／及び他の
芳香族ジカルボキシル残基と置換したコポリアミ
ド、又は[Formula] A copolyamide in which 10 mol% or less of the units are substituted with other aromatic diamino residues or/and other aromatic dicarboxyl residues, or

【式】及び[Formula] and

【式】の単位より成るコポリアミドを総称する。これらPPTA系ポリマーは単
独、または混合物のいずれであつても本発明法に
用いることができる。本発明法のPPTA系繊維の製造法においては、
少くとも強度が18ｇ／ｄ以上、伸度が３％以上、
かつ初期モジユラスが250ｇ／ｄ以上を示す如く
高性能繊維が対象とされるべきであり、そのため
には、使用されるPPTA系ポリマーの重合度が一
定の値以上のものでなければならず、固有粘度
（ηinh）で表わして3.5以上、特に4.5以上である
ことが望ましい。かかるPPTA系ポリマーから、本発明法に用い
られる紡糸用ドープは、既に公知の方法によつて
調製される。その際、溶剤としては、工業的には
濃硫酸が有利に用いられる。濃硫酸の濃度は、98
〜100.2重量％が好ましく、特に高い固有粘度を
有するPPTA系ポリマーを高濃度に溶解する場合
には99重量％以上のものが用いられる。紡糸用ドープは、溶媒100ml当り少なくとも30
ｇのPPTA系ポリマーを含むように調製すること
が好ましい。更に好ましくは33ｇ以上のPPTA系
ポリマーを含むように調製する。しかしながら、ポリマー濃度が高すぎるとドー
ドープの粘度が高くなりすぎるため、ドープ温度
を高く設定する必要があり、紡糸操作上困難を伴
いやすい。従つて、高過ぎないよう選ばれるべき
である。ドープの調製および使用に当つては、上
記ポリマー濃度範囲においては、ドープは室温付
近では個化する場合があるため、室温から80℃程
度の温度で取扱えばよい。しかしながら、ポリマ
ーの分解を可及的に回避する観点から、固化しな
い限りなるべく低い温度を選ぶことが好ましい。このようにして調製された紡糸用ドープは、上
記のポリマー濃度、ドープ温度範囲で光学的異方
性を有することが認められる。かかるドープが本
発明法において使用され、紡糸口金を通して一旦
空気又は、非凝固性の液体層、通常空気中に押し
出され、ついで凝固浴中に導びかれる。その際、
凝固浴中の凝固しつつある、または凝固した糸条
はほとんど引き伸ばしが行なわれないため、吐出
されたドープは非凝固性の流体層において、引き
取りのドラフト（引き伸ばし）がかかり、引き伸
ばされる。この引き伸ばしにおいて、引き伸ばし
率が低いと充分に繊維の物性を高めることが出来
ず、また、高すぎるとこの間でドープ流が切断さ
れるため、通常は、引き伸ばし率は４〜15倍、好
ましくは５〜12倍の間に設定される。ドープの引き伸ばしが行なわれる空気又は非凝
固性の流体層の長さ、即ちドープの吐出される紡
糸用口金の面から凝固浴液表面までの距離は、通
常約１〜50mm、好適には３〜20mmの範囲に設定さ
れるが、これに限定されるものではない。具体的
には、紡糸用口金からのドープの吐出速度、上記
のドラフト率、フイラメントの融合機会を少くす
ること等を考慮して決定される。また、ドープの吐出に際して用いられる紡糸用
口金の孔径は、製造しようとする繊維の太さ、及
び上記のドラフト率の設定により選定されるべき
であつて、通常は0.05〜0.10mmの範囲のものが選
択されるが、これに限られるものではない。更に
紡糸用口金に設けられる孔数は、製造しようとす
る繊維の構成によつて決定されるべきものであ
り、特に本発明法に実施するに当つて格別限定さ
れるものではない。本発明の効果を充分に発揮させるためには、一
次凝固液として10％以上の硫酸水溶液が用いら
れ、該硫酸濃度は高ければ高い程その効果が大き
い。しかし70％を超えると糸条は、凝固の遅れが
著しくなり、僅かな抵抗で高次構造の破壊をきた
すため、二次凝固液の硫酸濃度を一次凝固液の硫
酸濃度より低くし、凝固を早めることが好まし
い。工業的に有利な硫酸水溶液を凝固液に用いて、
高性能のPPTA系繊維を製造するための本発明法
においては、前記の様にして吐出され、引き伸ば
されたドープを一次凝固液中に導き、糸条を形成
しつつ、凝固浴下部に設けられた細管に導き、更
に紡速の少なくとも80％の速度で凝固液が流れる
流管中へ糸条を走行させることに最大の特徴があ
る。 PPTA系繊維の形成過程においては、凝固によ
つて形成される高次構造の破壊、配向の進行等の
変化を伴ないながら繊維が形成されるが、これら
は単に張力のみの作用をうけるものではなく、そ
の張力が付与された糸条の凝固状態によつても大
きく変化するものである為、各凝固状態での張力
覆歴が最終製品糸の構造及び機械的な物性に反映
することは、理解されるべきである。 PPTA系繊維を10％以上の硫酸水溶液で一次凝
固させ製造する場合にあつては、硫酸濃度の上昇
と共に該水溶液の粘度、及び比重の増加による紡
糸張力の増大、更に凝固糸条中の硫酸濃度と凝固
液の硫酸濃度の差の減少により凝固の遅れが同時
に起こることによつて、凝固不完全な未凝固糸条
は、より低い張力で構造破壊を生じる。従つて紡
糸張力を低減することが重要であり、この為には
一次凝固液の速度を糸条速度まで加速する必要が
ある。しかしながら、単に凝固浴下部に細管又は
細孔を設け、糸条と共に一次凝固液を重力の加速
度によつて加速する方法、或いは、強制的に例え
ば下向きのジエツト流などにより二次凝固液の速
度を加速する方法においては、見掛け上引取時に
計測される紡糸張力は低減されるものの、自由落
下域で重力の加速度が働き、二次凝固液の落下速
度が逐次高まり、糸条と落下液との速度差を一定
に保つことが出来なかつた。この結果、凝固途中
の糸条に抵抗覆歴を与え高次構造の破壊を引き起
し充分に高い強度及び伸度を合せ持つPPTA系繊
維を得るには至らない。従つて、10％以上の硫酸水溶液を凝固液として
強度及び伸度共に優れた高性能のPPTA系繊維を
製造するためには、凝固の完成度の低い未凝固糸
条においても繊維構造の破壊を引き起さない様
に、更に、伸度の低下を招く配向の進行を抑制す
る様に、凝固状態に応じて張力を低減すると同時
に、その低張力の状態を一定時間維持することが
必要である。その為には、糸条に随伴する二次凝
固液の流速を加速して糸条と二次凝固液との摩擦
抵抗を減少せしめ、かつ、一旦加速された凝固液
は一定速度を保たせることによつて、この間で糸
条にかかる張力を極めて低い状態に保ちつつ凝固
を進行させ繊維を形成することが出来るのであ
る。ここに、直管を設け、二次凝固液を一定速度
で流す本発明法の一つの重要な意義があることは
理解されなければならない。また、糸条束又は糸
条の一部が前記直管の影響を受ける領域を走行す
ることは、張力増加につながる為さける必要があ
る。従つて、直管の上部に細管を設け、糸条を流
管中に導く前に該細管に該糸条を一端導くこと
に、本発明のもう一つの重要な意義があることも
理解されなければならない。上述した様に、強度及び伸度共に優れた高性能
PPTA系繊維を製造するには、糸条の凝固状態に
応じて、紡糸張力の低減を図る必要があり、か
つ、該低張力の状態を一定時間維持する必要があ
る。特に、300ｍ／分以上の紡糸速度を採用して、
強度及び伸度共に優れたPPTA系繊維を製造する
には、凝固浴下部に設けられた細管を経由して、
少なくとも紡糸速度の80％、好ましくは90％、更
に好ましくは95％以上の速度で凝固液が流れる流
管中へ糸条が導かれる。特に、一次凝固液の硫酸
濃度が高ければ高い程糸条の凝固が遅れる為、そ
の時かかる張力は更に低いものとする必要があ
り、流管中の凝固液の速度を紡糸速度により近づ
けることが好ましい。また、紡糸速度を高めた場合も同様のことが言
えるし、流管中に供給される二次凝固浴の硫酸濃
度を高めた場合も同様である。逆に、凝固の完成
度が高い糸条、例えば10％硫酸水溶液の一次凝固
浴で300ｍ／分で紡糸されている糸条では、張力
の比較的高い状態、又は流管中の凝固液の速度が
紡糸速度より速い状態においても繊維の高次構造
の破壊が抑制される為、該凝固液の速度を紡糸速
度の150％もの大きさまですることができ、更に、
該凝固液と糸条とを分離する工程に細孔を設け
る、あるいは気体を噴射する等の糸取出の工夫を
することで、該凝固液の速度を更に高めることも
出来る。一方流管の設計に当つては、前述した様に流管
中を走行する糸条が該流管の壁面の影響を極力受
けない様に、該流管の上端に設けた細管の断面積
の２倍以上の断面積になるような径を有する流管
を採用することが重要であり、上記断面積比が２
倍未満になると走行糸条に流管の壁面の悪影響が
及ぼされ、高強度のPPTA繊維が得られない。流
管の径を大きくすることは、供給する凝固液の量
が増大しエネルギーの増加につながる為、コスト
の面から該流管の径の上限が決定される。また、流管中を走行する糸条が管壁の影響をう
けないためには、該流管の形状が実質的に直管で
あることが好ましい。しかし、該流管が大きい内
径を有している及び／、または短かい場合は、該
流管中を走行する糸条が管壁の影響をうけにくい
ため、曲管であつてもよい。上記流管の長さは、本発明法において極めて重
要な要件の一つである。即ち、糸条の凝固の完成
度が極めて低い状態で流管中より糸条が自由落下
域に引き出されることは、わずかな張力及び／又
は抵抗変化で糸条の高次構造の破壊を招き、繊維
性能の低下のつながる為、少なくとも10mm秒以上
走行する糸条が滞留出来るような流管長を有する
ことが必要であり、該流管長は、紡糸速度の高速
化及び／又は一次、二次凝固液の硫酸濃度の高濃
度化に伴ない長く設定することが肝要である。本発明における細管は、糸条を収束させて前記
流管に導く役目があると同時に、該流管中から凝
固浴表面に向かつて流れる二次凝固液の急激な噴
出を防ぐ役目を有している。従つて、該細管は、
長さと内径の比が0.5以上に設計すると同時に、
かつ、該細管の下端部が少なくとも挿入される様
に流管を設置することが重要であり、該条件が一
方でも満たされなければ、紡浴表面及び内部に不
安定な流れを生じ、長時間安定して紡糸すること
が出来ない。本発明法の典型的な操作を第１図の紡糸装置で
示す。この装置では、細管１１を上端に有する流
管１２が紡浴下部に設けられている。一次凝固液
は供給ノズル２２を通して紡浴中に液の供給がな
され、二次凝固液は供給ノズル１３を通して液の
供給がなされる。本発明法に係る細管と流管との
位置関係は、第２図Ａに示すように細管の下端面
と流管の上端面とが少なくとも交わる関係にあ
り、特に第２図Ｂのように両端面が重なる位置関
係がより好ましい。更に、流管の中心と細管の中心とが一致するよ
うに設置することが好ましいが、一致しなくても
特に問題はない。細管及び流管の断面形状は、通
常円形のものが用いられるが、本発明法において
は特に限定されるものではなく、例えば矩形、三
角形状あるいは橢円状など、いずれであつてもよ
い。更に、上記断面形状が第３図Ｂのように長さ方
向で変化していてもよいが、細管の最小断面積の
少なくとも２倍以上の断面積になるような最小径
を有する流管とすることが必要である。本発明の実施に当つては、流管の上端に設けら
れた細管は凝固浴液表面から200mm以内の深さに
設置されることが好ましく、通常は10〜150mm、
特に好ましくは10〜100mmの範囲に設置される。本発明法によつて凝固形成された糸条は、流管
から、例えばネルソンロール等の引き取り手段に
よつて600ｍ／分以上の極めて高い速度で引き取
られ、付着する凝固液あるいは残存する溶剤硫酸
の中和、洗浄、乾燥等の仕上工程に供される。そ
の際、形成された糸条繊維中に含有される酸の中
和、洗浄、または中和によつて生じた塩の洗浄
は、最終的に得られるPPTA系繊維の品質上特に
徹底して行われることが好ましく、これらの処理
に長時間を必要とする。このような徹底した中和
又は洗浄を長時間に渡り実施する方法として、多
数のロールを組み合わせて滞留時間を長くとる方
法であつても差支えないが、特に、特公昭55−
9088号報による、ネツトコンベヤー上にPPTA系
繊維を堆積して水洗、中和、乾燥する方法が、工
業的にも且つ高品質の繊維を得る上からも好まし
く用いられる。更には、本発明法の実施に当つて
例えば特公昭54−36698号報にて提案されたネツ
トコンベヤー上での乾燥後さらに熱処理を行うこ
と等の処理を行なうことも許される。本発明は、すべてのPPTA系繊維の製造に対し
て有効であるが、PPTA系繊維自体、高い結晶性
の故か、繊維がフイブリル化しやすかつたり、割
れやすいこともあつて、単繊維の太さは、太すぎ
ないことが望ましい。通常は大略10デニール以
下、好ましくは３デニール以下に設定される。総
繊維の線密度は20〜4500デニール、通常、50〜
3000デニールであることが好ましい。実施例以下、実施例によつて本発明を更に詳細に説明
するが、これらの実施例は何ら本発明を限定する
ものでない。実施例中、特にことわりのない限り「％」は重
量パーセントを表わす。また、本発明法において
用いられる種々のパラメーターの主なものは以下
の様にして測定されたものである。固有粘度の測定法；固有粘度（ηinh）は、98.5重量％の濃硫酸に濃
度（Ｃ）＝0.5ｇ／dlでポリマーまたは繊維を溶か
した溶液を30℃にて常法により測定する。 ηinh＝ln・ηrel／Ｃ繊維の強伸度特性の測定法；繊維糸条の強度、伸度およびヤング率の測定は
JIS規格に準じ、測定に先立つて10cm当り、８回
の撚りを加えた糸条について、定速伸長型強伸度
試験機により、把握長20cm、引張り速度50％／分
にて、荷重一伸長率典線を描き、それより読み取
り、または算出したもので、測定数20個の平均値
で表わす。流管と細管の断面積比；流管の内径をD₁、細管の内径をD₂とすると共
に円形のものを用いた場合は、次式により計算さ
れる。（D₁／D₂）²＝断面積比流管中の凝固液の速度；一次凝固液の供給量と該凝固液を有する紡浴か
らのオーバーフロー量との差から細管部の吸引量
（条件によつては、噴出量）と二次凝固液の供給
量より、流管中を通る凝固液量を求め、該凝固液
量を流管の断面積で除した値、即ち平均流速を流
管中の凝固液速度とする。参考例低温溶液重合法により次の如くPPTAポリマー
を得た。特公昭53−43986号公報に示された重合装置中
でＮ−メチルピロリドン1000部に無水塩化カルシ
ウム70部を溶解し、次いでパラフエニレンジアミ
ン48.6部を溶解した。８℃に冷却した後、テレフ
タル酸ジクロライド91.4部を粉末状で一度加え
た。数分後に重合反応物はチーズ状に固化したの
で、特公昭53−43986号公報記載の方法にしたが
つて重合装置より重合反応物を排出し、直ちに２
軸の密閉型ニーダーに移し、同ニーダー中で重合
反応物を微粉砕した。次に微粉砕物をヘンシエル
ミキサー中に移し、ほぼ等量の水を加えてさらに
粉砕した後、濾過し、数回温水中で洗浄して、
110℃の熱風中で乾燥した。固有粘度が6.2の淡黄
色のPPTA系ポリマー95部を得た。なお、異なつた固有粘度のポリマーは、Ｎ−メ
チルピロリドンとモノマー（パラフエニルレンジ
アミンおよびテレフタル酸ジクロライド）の比、
または／およびモノマー間の比等を変えることに
よつて容易に得ることができる。実施例１参考例に従つて製造した固有粘度（ηinh）が
6.9のポリーパラフエニレンテレフタルアミドを、
ポリマー濃度が19.2％になるように99.7％の濃硫
酸に、温度を80℃に保ちながら溶解し、紡糸用の
ポリマー溶液（以下ドープと略称）を調製した。
このドープは、光学的異方性を示すことが、直交
ニコル下の偏光顕微鏡観察で確認された。このドープを真空下４時間静置脱泡後、紡糸に
用いた。ドープをギアポンプを通して300メツシ
ユステンレス金綱を８重に巻いたキヤンドルフイ
ルターを通して濾過後、第１図に示す紡糸用装置
に設置された0.06mmφの孔径、100個の孔数を有
する紡糸用口金から５mmの空気中を通して40％硫
酸水溶液の一次凝固液中に押し出した。流管中に
供給する二次凝固液は、同じく30％硫酸水溶液
で、凝固液の温度は一次、二次凝固液共に２℃で
あつた。流管中から取出された糸条は、変向ロールにて
変向後、ネルソンロールにより引き取り、次いで
ワインダーによりボビン上に捲き取り、このボビ
ンを流れ中に２夜浸漬して糸条を洗浄後、110℃
の熱風乾燥機中で乾燥した。この際紡糸に用いた装置は第１図に示すもので
あり、一次凝固液で満たされた凝固浴槽（直径
200mm、深さ100mm）と上端に細管（直径２mmφ、
長さ10mm）を有する流管（直径６mmφ、長さ400
mm）とからなるものである。流管には、二次凝固液を供給するための、供給
ノズル13が付してあり、細管１１の下端面と流管
１２の上端面とは、２mmの重なり部を有するよう
に調整されており、一次凝固液の表面から60mmの
深さに細管が設けられている。紡糸に当つては、流管中の流速が設定速度にな
るように二次供給水量を調整した。以上の手段で、ドラフト率（ドープの吐出線
速／糸条の引き取り速度）を5.7で一定として、
各紡糸速度及び流速（流管中）で紡糸し、得られ
た繊維の物性を第１表に示す。比較例としては、管長を20mmとし、凝固が極め
て不完全のまま自由落下域に引き出す公知の紡糸
方法で製造された繊維物性を示した。なお、この
時の流管径は４mmφで、二次凝固液の供給水量が
５／分、細管部の給水量が0.95／分であつ
た。A general term for copolyamides consisting of the units of [Formula]. These PPTA-based polymers can be used alone or as a mixture in the method of the present invention. In the method for producing PPTA fiber according to the present invention,
At least the strength is 18g/d or more, the elongation is 3% or more,
In addition, high-performance fibers with an initial modulus of 250 g/d or more should be targeted, and for this purpose, the degree of polymerization of the PPTA polymer used must be above a certain value, and the specific It is desirable that the viscosity (ηinh) is 3.5 or more, particularly 4.5 or more. The spinning dope used in the method of the present invention is prepared from such a PPTA-based polymer by a known method. In this case, concentrated sulfuric acid is industrially advantageously used as the solvent. The concentration of concentrated sulfuric acid is 98
The content is preferably 100.2% by weight, and 99% by weight or more is used especially when dissolving a PPTA polymer having a high intrinsic viscosity at a high concentration. The spinning dope should be at least 30% per 100ml of solvent.
It is preferable to prepare it so that it contains the PPTA-based polymer of g. More preferably, it is prepared to contain 33 g or more of PPTA polymer. However, if the polymer concentration is too high, the viscosity of the dope becomes too high, so it is necessary to set the dope temperature high, which tends to cause difficulties in the spinning operation. Therefore, it should be chosen not to be too expensive. When preparing and using the dope, in the above polymer concentration range, the dope may become individualized near room temperature, so it may be handled at a temperature from room temperature to about 80°C. However, from the viewpoint of avoiding decomposition of the polymer as much as possible, it is preferable to select a temperature as low as possible unless it solidifies. It is recognized that the spinning dope thus prepared has optical anisotropy within the above polymer concentration and doping temperature ranges. Such a dope is used in the process of the invention and is forced through a spinneret into air or a layer of non-coagulable liquid, usually air, and then introduced into a coagulation bath. that time,
Since the coagulating or coagulated yarn in the coagulation bath is hardly stretched, the discharged dope is drawn out by a draft (stretching) in the non-coagulable fluid layer. In this stretching, if the stretching rate is low, the physical properties of the fiber cannot be sufficiently improved, and if the stretching rate is too high, the dope flow will be cut off between these stretches, so the stretching rate is usually 4 to 15 times, preferably 5 times. Set between ~12x. The length of the air or non-coagulable fluid layer in which the dope is stretched, that is, the distance from the surface of the spinneret from which the dope is discharged to the surface of the coagulating bath, is usually about 1 to 50 mm, preferably 3 to 50 mm. The range is set to 20 mm, but is not limited to this. Specifically, it is determined in consideration of the dope discharging speed from the spinning nozzle, the above-mentioned draft rate, reducing the chance of filament fusion, etc. In addition, the hole diameter of the spinning nozzle used when discharging the dope should be selected depending on the thickness of the fiber to be manufactured and the above-mentioned draft rate setting, and is usually in the range of 0.05 to 0.10 mm. is selected, but is not limited to this. Further, the number of holes provided in the spinning nozzle should be determined depending on the structure of the fiber to be produced, and is not particularly limited when implementing the method of the present invention. In order to fully exhibit the effects of the present invention, a 10% or more sulfuric acid aqueous solution is used as the primary coagulation liquid, and the higher the sulfuric acid concentration, the greater the effect. However, if the concentration exceeds 70%, the coagulation of the yarn will be significantly delayed, and the higher-order structure will be destroyed with the slightest resistance. Therefore, the sulfuric acid concentration in the secondary coagulation solution should be lower than the sulfuric acid concentration in the primary coagulation solution to prevent coagulation. It is preferable to start early. Using an industrially advantageous sulfuric acid aqueous solution as a coagulation liquid,
In the method of the present invention for producing high-performance PPTA-based fibers, the dope discharged and stretched as described above is introduced into the primary coagulation liquid, and while threads are formed, the dope is placed at the bottom of the coagulation bath. The most important feature is that the yarn is guided into a thin tube, and further into a flow tube through which a coagulating liquid flows at a speed of at least 80% of the spinning speed. During the formation process of PPTA fibers, fibers are formed with changes such as the destruction of the higher-order structure formed by coagulation and the progression of orientation, but these are not simply affected by tension. Moreover, the tension varies greatly depending on the coagulation state of the yarn to which it is applied, so the history of tension in each coagulation state is not reflected in the structure and mechanical properties of the final product yarn. should be understood. When producing PPTA fibers by primary coagulation with a 10% or more sulfuric acid aqueous solution, as the sulfuric acid concentration increases, the viscosity of the aqueous solution and the spinning tension increase due to the increase in specific gravity, and the sulfuric acid concentration in the coagulated yarn increases. Due to the simultaneous delay in coagulation caused by a decrease in the difference in the sulfuric acid concentration between the sulfuric acid concentration and the coagulation solution, the incompletely coagulated uncoagulated thread undergoes structural failure at lower tensions. Therefore, it is important to reduce the spinning tension, and for this purpose it is necessary to accelerate the speed of the primary coagulation liquid to the yarn speed. However, there is a method in which a thin tube or a pore is simply provided at the bottom of the coagulation bath, and the primary coagulation liquid is accelerated together with the yarn by the acceleration of gravity, or the velocity of the secondary coagulation liquid is forcibly reduced by, for example, a downward jet flow. In the acceleration method, although the spinning tension measured at the time of take-up is apparently reduced, the acceleration of gravity acts in the free fall region, and the falling speed of the secondary coagulation liquid increases gradually, increasing the speed of the yarn and the falling liquid. It was not possible to keep the difference constant. As a result, it imparts a resistance history to the threads during coagulation, causing destruction of the higher-order structure, making it impossible to obtain PPTA fibers having sufficiently high strength and elongation. Therefore, in order to produce high-performance PPTA fibers with excellent strength and elongation using a 10% or more sulfuric acid aqueous solution as a coagulation liquid, it is necessary to prevent the destruction of the fiber structure even in uncoagulated yarns with a low degree of coagulation. It is necessary to reduce the tension according to the solidification state and maintain the low tension state for a certain period of time to prevent this from occurring and to suppress the progress of orientation that leads to a decrease in elongation. . To do this, the flow velocity of the secondary coagulating liquid accompanying the yarn must be accelerated to reduce the frictional resistance between the yarn and the secondary coagulating liquid, and the coagulating liquid once accelerated must maintain a constant velocity. During this time, coagulation can proceed and fibers can be formed while keeping the tension applied to the yarn extremely low. It must be understood here that there is one important significance of the method of the present invention in which a straight pipe is provided and the secondary coagulation liquid is caused to flow at a constant speed. Furthermore, it is necessary to avoid running a yarn bundle or a portion of the yarn through an area affected by the straight pipe, as this will lead to an increase in tension. Therefore, it must be understood that another important significance of the present invention lies in providing a thin tube at the upper part of the straight tube and guiding one end of the yarn into the thin tube before guiding the yarn into the flow tube. Must be. As mentioned above, high performance with excellent strength and elongation.
In order to produce PPTA-based fibers, it is necessary to reduce the spinning tension depending on the coagulation state of the yarn, and it is necessary to maintain the low tension state for a certain period of time. In particular, by adopting a spinning speed of 300 m/min or more,
In order to produce PPTA-based fibers with excellent strength and elongation,
The yarn is guided into a flow tube through which the coagulating liquid flows at a rate of at least 80%, preferably 90%, more preferably 95% or more of the spinning speed. In particular, the higher the sulfuric acid concentration in the primary coagulation liquid, the slower the coagulation of the yarn, so the tension applied at that time needs to be lower, and it is preferable to bring the speed of the coagulation liquid in the flow tube closer to the spinning speed. . The same thing can be said when the spinning speed is increased, and the same is true when the sulfuric acid concentration of the secondary coagulation bath supplied into the flow tube is increased. On the other hand, for yarns with a high degree of coagulation, for example yarns spun at 300 m/min in a primary coagulation bath of 10% sulfuric acid aqueous solution, the tension is relatively high or the speed of the coagulation liquid in the flow tube is high. Since the destruction of the higher-order structure of the fiber is suppressed even when the spinning speed is higher than the spinning speed, the speed of the coagulating liquid can be increased to as much as 150% of the spinning speed.
The speed of the coagulating liquid can be further increased by creating pores in the process of separating the coagulating liquid from the yarn, or by ejecting gas or other methods for removing the yarn. On the other hand, when designing the flow tube, the cross-sectional area of the thin tube provided at the upper end of the flow tube should be adjusted so that the thread running through the flow tube is not affected by the wall surface of the flow tube as much as possible. It is important to use a flow tube with a diameter that makes the cross-sectional area more than double, and the cross-sectional area ratio above is 2.
If it is less than twice that, the running yarn will be adversely affected by the wall surface of the flow tube, making it impossible to obtain high-strength PPTA fibers. Increasing the diameter of the flow tube increases the amount of coagulation liquid to be supplied, leading to an increase in energy, so the upper limit of the diameter of the flow tube is determined from the cost perspective. Further, in order to prevent the thread running through the flow tube from being affected by the tube wall, it is preferable that the flow tube has a substantially straight shape. However, if the flow tube has a large inner diameter and/or is short, the flow tube may be a curved tube because the yarn running in the flow tube is less affected by the tube wall. The length of the flow tube is one of the extremely important requirements in the method of the present invention. In other words, if the thread is pulled out from the flow tube into the free fall region in a state where the degree of coagulation of the thread is extremely low, the higher-order structure of the thread may be destroyed due to a slight change in tension and/or resistance, and the fiber To avoid this, it is necessary to have a flow tube length that allows the thread running for at least 10 mm seconds to stay there, and the flow tube length is determined by increasing the spinning speed and/or increasing the primary and secondary coagulation liquid. As the sulfuric acid concentration becomes higher, it is important to set the time longer. The thin tube in the present invention has the role of converging the threads and guiding them to the flow tube, and at the same time has the role of preventing a sudden spout of the secondary coagulation liquid flowing from the flow tube toward the surface of the coagulation bath. There is. Therefore, the tubule is
At the same time, the length to inner diameter ratio is designed to be 0.5 or more,
In addition, it is important to install the flow tube so that at least the lower end of the thin tube is inserted, and if one of these conditions is not met, unstable flow will occur on the surface and inside of the spinning bath, resulting in a long period of time. It is not possible to stably spin the yarn. A typical operation of the method of the invention is illustrated in the spinning apparatus of FIG. In this device, a flow tube 12 having a capillary tube 11 at its upper end is provided at the bottom of the spinning bath. The primary coagulating liquid is supplied into the spinning bath through the supply nozzle 22, and the secondary coagulating liquid is supplied through the supply nozzle 13. The positional relationship between the capillary and the flow tube according to the method of the present invention is such that the lower end surface of the capillary and the upper end surface of the flow tube at least intersect as shown in FIG. 2A, and in particular, as shown in FIG. A positional relationship in which the surfaces overlap is more preferable. Furthermore, although it is preferable to install the flow tube so that the center of the flow tube and the center of the thin tube coincide with each other, there is no particular problem even if they do not coincide with each other. The cross-sectional shapes of the thin tubes and flow tubes are generally circular, but are not particularly limited in the method of the present invention, and may be, for example, rectangular, triangular, or oval. Furthermore, the cross-sectional shape may vary in the length direction as shown in FIG. 3B, but the flow tube should have a minimum diameter that is at least twice the minimum cross-sectional area of the thin tube. It is necessary. In carrying out the present invention, the thin tube provided at the upper end of the flow tube is preferably installed at a depth of 200 mm or less from the surface of the coagulation bath, usually 10 to 150 mm,
Particularly preferably, it is installed in a range of 10 to 100 mm. The yarn coagulated by the method of the present invention is taken off from the flow tube by a taking means such as a Nelson roll at an extremely high speed of 600 m/min or more, and the attached coagulating liquid or the remaining solvent sulfuric acid is removed. It is used for finishing processes such as neutralization, washing, and drying. At this time, the neutralization and washing of the acids contained in the formed yarn fibers, or the washing of the salts generated by the neutralization, must be particularly thorough in order to ensure the quality of the PPTA fibers finally obtained. These treatments require a long time. As a method for carrying out such thorough neutralization or cleaning over a long period of time, it is possible to use a method in which a large number of rolls are combined to increase the residence time, but in particular,
The method disclosed in Japanese Patent No. 9088, in which PPTA fibers are deposited on a net conveyor, washed with water, neutralized, and dried, is preferably used from the viewpoint of obtaining high-quality fibers from an industrial standpoint. Furthermore, in carrying out the method of the present invention, it is also permissible to carry out further heat treatment after drying on a net conveyor as proposed in Japanese Patent Publication No. 54-36698. Although the present invention is effective for the production of all PPTA fibers, PPTA fibers themselves tend to fibrillate and crack easily due to their high crystallinity. It is desirable that it is not too thick. Usually, it is set to about 10 denier or less, preferably 3 denier or less. Total fiber linear density is 20~4500 denier, usually 50~
Preferably it is 3000 denier. Examples Hereinafter, the present invention will be explained in more detail with reference to Examples, but these Examples are not intended to limit the present invention in any way. In the examples, "%" represents weight percentage unless otherwise specified. Further, the main various parameters used in the method of the present invention were measured as follows. Measuring method of intrinsic viscosity; Intrinsic viscosity (ηinh) is measured by a conventional method at 30° C. using a solution of polymer or fiber dissolved in 98.5% by weight concentrated sulfuric acid at a concentration (C) of 0.5 g/dl. ηinh=ln・ηrel/C Method for measuring strength, elongation and elongation characteristics of fibers; Measuring the strength, elongation and Young's modulus of fiber yarn
According to the JIS standard, the yarn was twisted 8 times per 10 cm prior to measurement, and was subjected to load-elongation using a constant speed elongation type strength and elongation tester at a gripping length of 20 cm and a pulling speed of 50%/min. It is calculated by drawing a rate line and reading or calculating it, and is expressed as the average value of 20 measurements. Cross-sectional area ratio of flow tube and capillary; When the inner diameter of the flow tube is D ₁ and the inner diameter of the capillary is D ₂ and a circular one is used, it is calculated by the following formula. (D ₁ /D ₂ ) ² = cross-sectional area specific flow velocity of the coagulating liquid in the tube; From the difference between the supply amount of the primary coagulating liquid and the overflow amount from the spinning bath containing the coagulating liquid, the suction amount of the thin tube part (conditions Depending on the situation, the amount of coagulated liquid passing through the flow tube is determined from the amount of ejection) and the supply amount of the secondary coagulated liquid, and the value obtained by dividing the amount of coagulated liquid by the cross-sectional area of the flow tube, that is, the average flow velocity, is calculated from the flow tube. Let the coagulation liquid velocity be the same. Reference Example A PPTA polymer was obtained as follows by a low temperature solution polymerization method. In a polymerization apparatus shown in Japanese Patent Publication No. 53-43986, 70 parts of anhydrous calcium chloride was dissolved in 1000 parts of N-methylpyrrolidone, and then 48.6 parts of paraphenylenediamine were dissolved therein. After cooling to 8°C, 91.4 parts of terephthalic acid dichloride was added once in powder form. After several minutes, the polymerization reaction product solidified into a cheese-like shape, so the polymerization reaction product was discharged from the polymerization apparatus according to the method described in Japanese Patent Publication No. 53-43986, and immediately
The mixture was transferred to a closed-shaft kneader, and the polymerization reaction product was pulverized in the same kneader. Next, the finely ground material was transferred to a Henschel mixer, and approximately the same amount of water was added thereto for further grinding, followed by filtration, washing in hot water several times, and
It was dried in hot air at 110°C. 95 parts of a pale yellow PPTA polymer with an intrinsic viscosity of 6.2 was obtained. In addition, polymers with different intrinsic viscosities have different ratios of N-methylpyrrolidone and monomers (paraphenyl diamine and terephthalic acid dichloride),
Alternatively, it can be easily obtained by changing the ratio between monomers, etc. Example 1 The intrinsic viscosity (ηinh) manufactured according to the reference example was
6.9 polyparaphenylene terephthalamide,
A polymer solution for spinning (hereinafter abbreviated as dope) was prepared by dissolving the polymer in 99.7% concentrated sulfuric acid to a polymer concentration of 19.2% while maintaining the temperature at 80°C.
It was confirmed by polarizing microscopy observation under crossed Nicols that this dope exhibits optical anisotropy. This dope was left standing under vacuum for 4 hours to defoam, and then used for spinning. After passing the dope through a gear pump and filtering it through a candle filter made of eight layers of 300-mesh stainless steel wire, it was passed through a spinning nozzle with a hole diameter of 0.06 mm and 100 holes installed in the spinning device shown in Figure 1. It was extruded through 5 mm of air into a primary coagulation solution of 40% sulfuric acid aqueous solution. The secondary coagulation liquid supplied into the flow tube was the same 30% sulfuric acid aqueous solution, and the temperature of the coagulation liquid was 2°C for both the primary and secondary coagulation liquids. The yarn taken out from the flow tube is changed direction with a change-of-direction roll, then taken up with a Nelson roll, then wound onto a bobbin with a winder, and the bobbin is immersed in the flow for two nights to wash the yarn. 110℃
dried in a hot air dryer. The apparatus used for spinning was shown in Fig. 1, which consisted of a coagulation bath (diameter:
200mm, depth 100mm) and a thin tube (diameter 2mmφ,
Flow tube (diameter 6mmφ, length 400mm) with
mm). The flow tube is equipped with a supply nozzle 13 for supplying the secondary coagulation liquid, and the lower end surface of the thin tube 11 and the upper end surface of the flow tube 12 are adjusted to have an overlap of 2 mm. A thin tube is provided at a depth of 60 mm from the surface of the primary coagulation liquid. During spinning, the amount of secondary water supply was adjusted so that the flow rate in the flow tube was at the set speed. Using the above method, with the draft rate (dope discharge linear speed/yarn take-up speed) constant at 5.7,
Table 1 shows the physical properties of the fibers obtained by spinning at various spinning speeds and flow rates (in the flow tube). As a comparative example, the physical properties of a fiber manufactured using a known spinning method with a tube length of 20 mm and drawn into a free fall region with very incomplete coagulation are shown. The diameter of the flow tube at this time was 4 mmφ, the amount of water supplied to the secondary coagulation liquid was 5/min, and the amount of water supplied to the thin tube part was 0.95/min.

【表】第１表からも明らかな様に、本発明法において
は、同一紡速の公知の紡糸法（比較例１）よりも
繊維の強度及び伸度共に優れた繊維が得られるこ
とが確認された。また、各紡速で流管中の流速が紡速の80％に満
たない条件下で製造された繊維は、繊維物性が極
めて低く、該液速が紡速の80％以上においては高
強度及び高伸度を有する優れた繊維を得た。実施例２固有粘度（ηinh）が7.24のポリーパラフエニレ
ンテレフタルアミドを99.8％の濃硫酸中に、ポリ
マー濃度が19.5％になるように、70℃で２時間溶
解した。溶解は真空下で行ない、次いで２時間の
静置脱泡を行なつた後紡糸に使用した。このドープを、孔径0.07mmφ、孔数500個を有
する紡糸用口金から、ドラフト率が7.9となるよ
うに押出し、細管の形状の違いを除いては実施例
１と同じ第１図に示す装置を用いて、一旦10mmの
空間を走行させたのち、温度を０〜３℃に保つた
20％硫酸水溶液を一次凝固液と二次凝固液として
用いて、第２表の紡糸条件で紡糸を行なつた。そ
の際、流管上端の細管の形状は、第３図Ａのよう
な内径４mmφ長さ10mmと内径６mmφ長さ10mmの形
状であり、流管の上端面と該細管の下端面とは、
４mmの重なり部を有していた。糸条は、一次凝固液の表面から30mmの深さに設
置された細管、更に設定速度で二次凝固液が流れ
る流管（内径12mmφ）を通つて、細管より下方
400mmに設けた変向ロールにて変向後、ネルソン
ロールにて引き取り、次いで、第４図に示す
PPTA繊維の連続製造装置（特公昭55−9088号公
報に記載）により、即ち糸条を一対のギヤーニツ
プロール（歯車状のロールが浅く噛み合い、その
間で糸条を送り出す）により反転ネツト上に振り
込み、次いで処理コンベアー上に反転させて乗せ
た。処理コンベアー上に乗せられた糸山は、シヤ
ワー方式による水洗水により洗浄された後、乳化
剤により水中に分散させた鉱物油を１％含有する
油剤液を給付され、次いで200℃の熱風乾燥を行
つた後、コンベアー上から取り上げられ、ワイン
ダーによりボビン上に捲きとられた。[Table] As is clear from Table 1, it was confirmed that the method of the present invention yields fibers with superior fiber strength and elongation compared to the known spinning method (Comparative Example 1) at the same spinning speed. It was done. In addition, fibers produced under conditions where the flow rate in the flow tube is less than 80% of the spinning speed have extremely low fiber properties, and when the liquid speed is 80% or more of the spinning speed, the fibers have high strength and Excellent fibers with high elongation were obtained. Example 2 Polyparaphenylene terephthalamide having an intrinsic viscosity (ηinh) of 7.24 was dissolved in 99.8% concentrated sulfuric acid at 70°C for 2 hours so that the polymer concentration was 19.5%. Dissolution was carried out under vacuum, and the mixture was left to stand for 2 hours for degassing before being used for spinning. This dope was extruded from a spinning nozzle with a hole diameter of 0.07 mmφ and 500 holes at a draft rate of 7.9, and the apparatus shown in FIG. 1, which was the same as Example 1 except for the difference in the shape of the thin tube, was After running in a space of 10 mm, the temperature was maintained at 0 to 3℃.
Spinning was carried out under the spinning conditions shown in Table 2 using a 20% aqueous sulfuric acid solution as the primary coagulation liquid and secondary coagulation liquid. At this time, the shape of the thin tube at the upper end of the flow tube is as shown in Fig. 3A, with an inner diameter of 4 mmφ and a length of 10 mm, and an inner diameter of 6 mmφ and length of 10 mm, and the upper end surface of the flow tube and the lower end surface of the thin tube are as follows.
It had an overlapping part of 4 mm. The thread is passed through a thin tube installed at a depth of 30 mm from the surface of the primary coagulation liquid, and then through a flow tube (inner diameter 12 mmφ) through which the secondary coagulation liquid flows at a set speed, and then below the thin tube.
After changing the direction using a changing direction roll set at 400 mm, it is taken up using a Nelson roll, and then it is shown in Figure 4.
Using a continuous production device for PPTA fiber (described in Japanese Patent Publication No. 55-9088), yarn is transferred onto a reversing net using a pair of gear nip rolls (gear-shaped rolls are shallowly meshed and the yarn is sent out between them). Then, it was inverted and placed on a processing conveyor. The thread piles placed on the processing conveyor were washed with water using a shower system, then treated with an oil solution containing 1% mineral oil dispersed in water using an emulsifier, and then dried with hot air at 200°C. Thereafter, it was picked up from the conveyor and wound onto a bobbin by a winder.

【表】この様にして得られた繊維の性能は第２表に示
す。本発明法における繊維の性能は600ｍ／分以上
の高い紡糸速度においても、糸条の滞留時間が少
なくとも10mm秒以上になる様な流管長を有する
と、20％の硫酸水溶液を一次及び二次凝固液とし
て用いても、高強度及び高伸度を有する繊維が得
られた。実施例３固有粘度（ηinh）が7.91のポリーパラフエニレ
ンテレフタルアミドを99.7％の濃硫酸中に、ポリ
マー濃度が19.3％になるように、70℃で２時間溶
解した。溶解は真空下で行ない、ついで２時間の
静置脱泡を行なつたのち紡糸に使用した。このドープを孔径0.07mmφ、孔数500個を有す
る紡糸用口金から、ドラフト率が8.0となるよう
に押出し、実施例１と同じ第１図に示す装置を用
いて、一旦10mmの空間を走行させたのち、温度を
０〜３℃に保つた35％硫酸水溶液を一次及び二次
凝固液として用いて、第３表に示す紡糸を行なつ
た。その際、流管上端の細管は内径６mmφで該細
管の下端面と流管の上端面とは、いずれも１mmの
重なり部を有していた。糸条は、一次凝固浴の表面から30mmの深さに設
置された細管、更に設定速度で二次凝固液が流れ
る流管を通つて、細管より下方500mmに設けた変
向ロールにて変向後、ネルソンロールにて引き取
り、ついで実施例２と同様の工程を経てボビン上
に捲き取られた。この様にして得られた繊維の性能を第３表に示
す。即ち、一次及び二次凝固液に35％硫酸水溶液を
用いても、流管の断面積と細管の断面積との比を
少なくとも２以上にすることで、高強度及び高伸
度を有する繊維が得られた。一方、細管の長さと内径の比が0.5に満たない
と、一次凝固液の浴中が安定せず糸条を安定して
引き取ることが出来なかつた。[Table] The performance of the fiber thus obtained is shown in Table 2. The performance of the fiber in the method of the present invention is that even at a high spinning speed of 600 m/min or more, if the flow tube length is such that the residence time of the yarn is at least 10 mm seconds or more, the primary and secondary coagulation of the 20% sulfuric acid aqueous solution is Even when used as a liquid, fibers with high strength and high elongation were obtained. Example 3 Polyparaphenylene terephthalamide having an intrinsic viscosity (ηinh) of 7.91 was dissolved in 99.7% concentrated sulfuric acid at 70° C. for 2 hours so that the polymer concentration was 19.3%. Dissolution was carried out under vacuum, and the mixture was left to stand for 2 hours for degassing before being used for spinning. This dope was extruded from a spinning nozzle with a hole diameter of 0.07 mmφ and 500 holes at a draft rate of 8.0, and was once run through a 10 mm space using the same device shown in Figure 1 as in Example 1. Thereafter, spinning as shown in Table 3 was carried out using a 35% aqueous sulfuric acid solution kept at a temperature of 0 to 3 DEG C. as the primary and secondary coagulation liquids. At this time, the thin tube at the upper end of the flow tube had an inner diameter of 6 mmφ, and the lower end surface of the thin tube and the upper end surface of the flow tube both had an overlapping portion of 1 mm. The yarn is passed through a thin tube installed at a depth of 30 mm from the surface of the primary coagulation bath, and then through a flow tube through which the secondary coagulation liquid flows at a set speed. The film was taken up using a Nelson roll, and then wound onto a bobbin through the same process as in Example 2. Table 3 shows the performance of the fibers thus obtained. In other words, even if a 35% aqueous sulfuric acid solution is used as the primary and secondary coagulation liquid, by setting the ratio of the cross-sectional area of the flow tube to the cross-sectional area of the capillary to at least 2, fibers with high strength and high elongation can be produced. Obtained. On the other hand, if the ratio of the length of the capillary to the inner diameter was less than 0.5, the bath of the primary coagulation liquid would not be stable and the yarn could not be drawn stably.

【表】比較例２細管の下端面と流管の上端面との重なり部が全
くないことを除いては、実施例３−６と同じ条件
で紡糸を試みたが、一次凝固液の紡浴中が不安定
となり、糸条を安定して引き取ることが出来なか
つた。比較例３実施例３に用いられたものと同じ紡糸用ドープ
を用い、同一の吐出条件で空間に吐出後、一次凝
固浴中に導いた。次いで一次凝固液表面から30mmの深さに設置さ
れた細管（内径６mmφ、長さ６mm）を通して糸条
及び一次凝固液を落下させ、細管から500mm下方
で変向ロールにて糸条を変向させた後、実施例２
と同様の工程を経て繊維を得た。得られた繊維の
物性を第２表に併記したが、本発明の繊維に比較
して性能面で著しく劣るものであつた。発明の効果本発明によるPPTA系繊維の製造法によれば該
ポリマーを溶解するための溶媒として用いる硫酸
の回収面で工業的に有利な10％以上の硫酸水溶液
を一次凝固液として製造される従来の繊維の物性
に対し、強度の10〜20％以上の向上に加えて、特
に伸度の約15〜30％以上の向上を達成することが
全てのPPTA系繊維の製造に対して可能である。
なお、かかる本発明法の著しい効果は、300ｍ／
分以上の紡糸速度において顕著に現われる。このように本発明法によつて得られたPPTA系
繊維は、強度及び伸度の両方に優れた繊維であつ
て、これらの優れた特性は、該繊維の実使用に当
つて消費性能上極めて有利である。本発明によつて得られたPPTA系繊維は、その
優れた特性によつて、衣料用、産業資材用を問わ
ず使用されるが、特にブレードホース、コンベア
ベルト、タイヤ、エアバツクなどのコムの補強
材、プラスチツクの強化繊維素材など、特に高強
度かつ高伸度の特徴が十分に活用される分野で有
用である。[Table] Comparative Example 2 Spinning was attempted under the same conditions as in Example 3-6, except that there was no overlap between the lower end surface of the capillary and the upper end surface of the flow tube. The inside became unstable, and the yarn could not be taken out stably. Comparative Example 3 The same spinning dope as that used in Example 3 was discharged into a space under the same discharge conditions, and then introduced into a primary coagulation bath. Next, the yarn and primary coagulated liquid were dropped through a thin tube (inner diameter 6 mmφ, length 6 mm) installed at a depth of 30 mm from the surface of the primary coagulated liquid, and the yarn was changed direction with a direction change roll 500 mm below the thin tube. After that, Example 2
Fibers were obtained through the same process. The physical properties of the obtained fibers are also listed in Table 2, and they were significantly inferior in terms of performance compared to the fibers of the present invention. Effects of the Invention According to the method for producing PPTA fibers according to the present invention, a 10% or more sulfuric acid aqueous solution is used as the primary coagulation liquid, which is industrially advantageous in terms of recovering sulfuric acid used as a solvent for dissolving the polymer. It is possible to improve the physical properties of all PPTA fibers by increasing the strength by 10 to 20%, and in particular by increasing the elongation by approximately 15 to 30%. .
Note that the remarkable effect of the method of the present invention is as follows:
This becomes noticeable at spinning speeds of minutes or more. As described above, the PPTA fiber obtained by the method of the present invention has excellent both strength and elongation, and these excellent properties are extremely important in terms of consumption performance when the fiber is actually used. It's advantageous. Due to its excellent properties, the PPTA fiber obtained by the present invention can be used for both clothing and industrial materials, but is particularly useful for reinforcing combs such as braided hoses, conveyor belts, tires, and airbags. It is especially useful in fields where the characteristics of high strength and high elongation are fully utilized, such as reinforcing fiber materials for materials and plastics.

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

第１図は本発明法に好適な紡糸装置の一例を示
す。第２図及び第３図は、第１図の細管と流管上
端部の例を示す図である。第４図は、PPTA繊維
の連続製造装置を示す。１１……細管、１２……流管、１３……二次凝
固液供給ノズル、２０……凝固液槽、２１……一
次凝固液、２２……一次凝固液供給ノズル、３０
……糸条変向用ロールガイド、４０……紡糸用口
金、５０……糸条及び凝固液流、６０……糸条、
７４……引き取り用ネルソンロール、７５……ギ
ヤーニツプロール、７６……反転ネツト、７７…
…糸山を送る為のコンベアーネツト、７８……水
洗用シヤワトレイ、７９……熱風乾燥機、８０…
…捲き取り用ワインダー、８１……糸山おさえ用
カバーネツト。 FIG. 1 shows an example of a spinning apparatus suitable for the method of the present invention. 2 and 3 are views showing examples of the thin tube and flow tube upper end portion of FIG. 1. Figure 4 shows an apparatus for continuous production of PPTA fibers. 11...Thin tube, 12...Flow tube, 13...Secondary coagulation liquid supply nozzle, 20...Coagulation liquid tank, 21...Primary coagulation liquid, 22...Primary coagulation liquid supply nozzle, 30
... Yarn direction roll guide, 40 ... Spinneret, 50 ... Yarn and coagulation liquid flow, 60 ... Yarn,
74... Nelson roll for take-up, 75... Gear unit roll, 76... Reversing net, 77...
...Conveyor net for sending thread piles, 78...Shower tray for washing with water, 79...Hot air dryer, 80...
...Winder for winding up, 81...Cover net for holding down thread piles.

Claims

【特許請求の範囲】１溶媒100ml当り、少なくとも30ｇのポリーパ
ラフエニレンテレフタルアミド系ポリマーを含む
98.0〜100.2％硫酸の光学的異方性を示す溶液を、
空気又は非凝固性の流体層を通して少なくとも10
％硫酸水溶液の一次凝固液に導き、次いで凝固浴
下部に設けられた細管中に糸条を導き走行させた
後、該糸条を洗浄、乾燥等の仕上げ工程に供する
湿式紡糸法により繊維を製造するにあたり、該細
管は長さと内径の比が0.5以上であつて、かつ、
該細管の下端部が挿入される様に流管を設置し、
その際該流管は細管の断面積の２倍以上の断面積
になるような内径、及び走行する糸条が10mm秒以
上滞留出来るような長さを有し、かつ、流管中の
凝固液速度が糸条速度の少なくとも80％になるよ
うに、該細管の下端面の上部から二次凝固液を供
給することを特徴とするポリーパラフエニレンテ
レフタルアミド系繊維の製造方法。２紡糸速度が少なくとも300ｍ／分である特許
請求の範囲第１項記載の製造方法。[Claims] 1. Contains at least 30 g of polyparaphenylene terephthalamide-based polymer per 100 ml of solvent.
A solution exhibiting optical anisotropy of 98.0-100.2% sulfuric acid,
at least 10 through the air or non-solidified fluid layer
% sulfuric acid aqueous solution, then the yarn is guided and run through a thin tube provided at the bottom of the coagulation bath, and then the yarn is subjected to finishing processes such as washing and drying to produce fibers. In doing so, the tubule has a length to inner diameter ratio of 0.5 or more, and
Install a flow tube so that the lower end of the thin tube is inserted,
In this case, the flow tube has an inner diameter that has a cross-sectional area that is at least twice the cross-sectional area of the thin tube, and a length that allows the running yarn to stay there for at least 10 mm seconds, and the coagulated liquid in the flow tube A method for producing polyparaphenylene terephthalamide fibers, characterized in that a secondary coagulation liquid is supplied from the upper part of the lower end surface of the capillary so that the speed is at least 80% of the yarn speed. 2. The manufacturing method according to claim 1, wherein the spinning speed is at least 300 m/min.