JP4392099B2

JP4392099B2 - Acrylic fiber manufacturing method

Info

Publication number: JP4392099B2
Application number: JP2000045899A
Authority: JP
Inventors: 素郎能村; 宏細川
Original assignee: Mitsubishi Chemical Corp; Mitsubishi Rayon Co Ltd
Current assignee: Mitsubishi Chemical Corp; Mitsubishi Rayon Co Ltd
Priority date: 2000-02-23
Filing date: 2000-02-23
Publication date: 2009-12-24
Anticipated expiration: 2020-02-23
Also published as: JP2001234426A

Description

【０００１】
【産業上の利用分野】
本発明は、アクリル系繊維を製造する際、凝固液としてイオン交換樹脂で処理した凝固液を用いて紡糸することにより、品質良好なアクリル系繊維を長期間安定に製造する方法に関する。
【０００２】
【従来の技術】
アクリロニトリル系重合体の紡糸方法としては、乾式紡糸法の他に、ノズルから直接凝固浴中に紡出する湿式紡糸法、ノズルからの紡出糸を一旦空気中を経たのちに凝固浴中に導く乾湿式紡糸法が知られている。湿式紡糸法、乾湿式紡糸法において凝固浴に使用される凝固液は、一般に経済面及び環境面の問題より、循環して繰り返し用いられている。しかし、この凝固液中には、その繰り返し使用により紡出糸の凝固の際に低分子量ポリマー、重合残渣物等が徐々に溶解してくることが知られており、これらの凝固液中に溶出した低分子量ポリマー、重合残渣物等が凝固浴中に浸漬されているノズル孔あるいは浴中ガイドの表面に堆積物として付着するため、糸切れ等の工程通過性および品質面で種々の問題を引き起こす原因となっている。
【０００３】
そこで、本発明者らは、先に乾湿式紡糸法において凝固浴中で糸条の走行方向を変更する浴中ガイドの下方より超音波振動を連続的または間欠的に与えることにより凝固糸との摩擦抵抗を減少させ、毛羽や繊度斑の少ないアクリル系繊維を得る技術を開発した（特開昭62−141111号公報、特開平10−219516号公報参照）。しかしながらこの方法でも、一時的な付着物の除去は可能であるが、脱落した低分子量ポリマーが再び凝固液中に溶解して蓄積され、再度析出してしまうため、上記問題点が根本的に解決されるまでには至っていない。
【０００４】
従って現状では、高品質のアクリル系繊維を長期間安定して得るという目的と凝固液の繰り返し使用という要請に答えるためには、ノズルあるいは浴中ガイドの交換が必要であり、工業生産上改善すべき大きな課題となっている。
【０００５】
【発明が解決しようとする課題】
本発明の目的は、循環して繰り返し使用する凝固液から紡糸性・品質に悪影響を与える低分子量ポリマー、重合残渣物等を除去してノズル孔あるいは浴中ガイドへの付着物を減少せしめることによって、上記従来の問題を解決し、均質なアクリル系繊維を長期間安定に製造することにある。
【０００６】
【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研究を行った結果、繰り返し使用する凝固液をイオン交換樹脂で処理し紡糸することによって、繰り返し使用での低分子量ポリマー等の付着による影響が低減され、均質なアクリル系繊維を長期間安定に製造する方法を見出した。
すなわち、本発明の要旨は、アクリロニトリル系重合体を、凝固液が循環して繰り返し使用される湿式紡糸法または乾湿式紡糸法にて、紡糸することによってアクリル系繊維を製造する方法において、凝固液を、１〜３級アミノ基を交換基とする弱塩基性陰イオン交換樹脂充填カラムに送液し、該イオン交換樹脂で処理することを特徴とするアクリル系繊維の製造方法にあり、凝固液中に溶出した低分子量ポリマー等を特定のイオン交換樹脂により捕捉させるものである。
【０００７】
【発明の実施の形態】
（イオン交換樹脂）
本発明に用いるイオン交換樹脂は、凝固液中に溶出した低分子量ポリマー等に対する捕捉性能を有しており、これらの溶出物の捕捉により凝固液の品質維持効果を奏するものが用いられ、例えば、実施例にも示したように、陰イオン交換樹脂、特に１〜３級アミノ基を交換基とする弱塩基性陰イオン交換樹脂が好ましく、更に好ましくは−ＣＨ_２ＮＨ（ＣＨ_２ＣＨ_２ＮＨ）ｎＨ基（ｎ：自然数）を交換基とする弱塩基性陰イオン交換樹脂である。
上記イオン交換樹脂の使用量は、イオン交換樹脂の捕捉能力、アクリロニトリル系重合体の組成、凝固液の種類、凝固液の濃度、凝固液の使用量等により適宜決定される。
【０００８】
（アクリロニトリル系重合体）
本発明の製造方法が適用されるアクリロニトリル系重合体としては、特に限定されないが、好適な重合体として、アクリロニトリルを１００〜５０重量％含有し、これと共重合可能な不飽和単量体０〜５０重量％とからなるアクリル系重合体が例示される。アクリロニトリル系重合体中のアクリロニトリル量が５０重量％以下の場合は、アクリル繊維の特徴である染色鮮明性、発色性が低下すると共に、熱特性をはじめとする他の物性も低下し好ましくない。共重合可能な不飽和単量体としてはアクリル酸、メタクリル酸、及びそれらの誘導体、酢酸ビニル、アクリルアミド、メタクリルアミド、塩化ビニル、塩化ビニリデン、さらに目的によってはビニルベンゼンスルホン酸ソーダ、メタリルスルホン酸ソーダ、アクリルアミドメチルプロパンスルホン酸ソーダ等のイオン性不飽和単量体を用いることができる。
【０００９】
上記アクリロニトリル系重合体の製造方法としては、懸濁重合、溶液重合等の公知の重合法が適用可能であり、特に限定されない。また、アクリロニトリル系重合体の分子量は通常アクリル繊維の製造に用いられる範囲の分子量であればよく、特に限定しないが、分子量が１０万〜１００万の範囲にあることが好ましい。
【００１０】
（紡糸原液）
紡糸原液はアクリロニトリル系重合体を１５重量％〜２８重量％濃度となるように溶剤に溶解して調製するが、濃度が１５重量％未満では、凝固時にノズル孔の形状と繊維断面の形状の差が著しく異なる傾向にあるため、目的の断面形状を得ることが困難となり好ましくない。一方濃度が２８重量％を超えると紡糸原液の経時安定性が悪くなり紡糸性が低下するので好ましくない。
溶剤としては、通常使われているアクリロニトリル系重合体用の溶剤、例えばジメチルホルムアミド、ジメチルアセトアミド、ジメチルスルホキシド等の有機溶剤、硝酸、ロダン酸塩水溶液、塩化亜鉛水溶液等を用いることができる。
【００１１】
（紡糸法）
本発明の紡糸法は、凝固液が循環して繰り返し用いられる湿式紡糸法または乾湿式紡糸法のいずれであってもよい。上記の紡糸原液を直接（湿式紡糸法）あるいは空気層を経て（乾湿式紡糸法）、イオン交換樹脂で処理されている凝固液であって、アクリロニトリル系重合体の溶剤と水とを主組成とする凝固液からなる凝固浴（以下、単に凝固浴ともいう）に導き、紡出して凝固糸とする。凝固浴条件は特に限定されないが、例えば溶剤としてジメチルアセトアミドを用いた場合、凝固浴温度０〜４０℃、溶剤濃度１０〜８５％が好ましい。
得られた凝固糸は、５０〜１００℃の温水中にて繊維中の溶剤分が１％以下になるまで洗浄処理され、８０〜１００℃の温水中にて２倍以上の湿熱延伸、油剤付与された後、１２０〜１８０℃の温度で乾熱処理されてアクリル系繊維となる。必要に応じて更に乾熱延伸処理、緩和等を行っても良く、これによりバランスのとれた力学特性が付与されたアクリル系繊維となる。
【００１２】
【実施例】
以下、実施例により本発明を具体的に説明する。
実施例中、凝固浴中に溶解している低分子量ポリマー等の含有量を蒸発乾固物量として示す。蒸発乾固物量は凝固液を８０℃、２．７ＫＰａで２４時間濃縮後、６０℃、６００Ｐａで２４時間減圧乾固して重量を測定して求めた。一般にこの含有量が高い程、浴中ガイド等への付着物量が多いと解釈することができる。また、凝固浴出張力は、浴中ガイドと凝固浴出の引き取りロール間の凝固糸にかかる張力を示した。一般にこの張力が高いほど浴中ガイドと凝固糸間の摩擦抵抗が高いと解釈することができる。この蒸発乾固物量、凝固浴出張力と共に、得られた最終繊維の繊度斑の指標としてＣＶ％、染色性の指標としてＭ率を示した。ＣＶ％の測定は、ＪＩＳＬ−７．２０Ａ法に基づき、ツェルベガーウースター社製ＵＳＴＥＲＴＥＳＴＥＲ３／Ｃを使用し、測定速度５０ｍ／分、撚り数Ｓ撚り２００Ｔ／ｍの条件にて測定した。またＭ率は、繊維糸にて作製した編地２００ｇを公知の方法で精練した後、アストラゾンブルーＦＲＲ２００（バイエル社製カチオン染料）０．３５重量％、染色温度９５℃、染色温度６０分の染色条件で得られる染色糸の濃淡を目視評価にて５段階（極淡色、淡色、中色、濃色、極濃色）に判別し、中色の割合を示したもので、Ｍ率が高いほど染色均一性が高いことを示す。
【００１３】
実施例１−３、比較例１−３
イオン交換樹脂として、表１に示す交換基を有する、三菱化学（株）製、ダイヤイオンＰＫ２２０、ＷＫ２０、ＷＡ１０、ＷＡ２０、ＷＡ３０（いずれも商品名）を使用した。イオン交換樹脂は、精製用イオン交換カラムに１００Ｌ充填し、その樹脂ベッドの深さは約７５０ｍｍとし、使用の凝固液をこのカラムに１５０Ｌ／Ｈの速度で送液するようにして、下記の乾湿式紡糸法にて、アクリル繊維の製造量を６０ｋｇ／日とし、１５日間紡糸操作を行った。
アクリロニトリル９３％、酢酸ビニル６％、スチレンスルホン酸ナトリウム１％からなる平均分子量３０万の共重合体をジメチルアセトアミドに溶解して、濃度が２５重量％の紡糸原液を調製し、これをほぼ６０℃に昇温した。一方６０個の円形孔を有する紡糸口金と凝固浴液面までの距離を１５ｍｍに設定し、上記昇温された紡糸原液を、紡糸口金から空気中に押し出し、この生成された紡糸原液の流れを直ちにジメチルアセトアミド７５％と水２５％の凝固液からなる凝固浴に導き、紡出糸を凝固させ繊維を形成させた。次いで凝固浴を通過した糸条を速度が５０ｍ／分の引き取りローラーに導いて牽引した。水洗後、沸騰水中における３．０倍の１次延伸を施し、乾燥後、１８０℃の熱ピンにおいて２．０倍の２次延伸を施した。その後、更に糸条を２５０℃の熱板上で７％の緩和処理を施して、繊度１５０ｄｔｅｘのフィラメント束として単糸繊度２．５ｄｔｅｘ（１５０ｄｔｅｘ／６０本）のアクリルフィラメントを得た。各実施例の紡糸での蒸発乾固物量、凝固浴出張力、得られた繊維の繊度斑（ＣＶ％）、Ｍ率の測定結果を表１に示す。
【００１４】
【表１】
【００１５】
表１から明らかなように、本発明の製造方法を用いることにより、凝固液の洗浄、繊度斑及び染色均一性効果が向上する。そして、イオン交換樹脂として弱塩基性陰イオン交換樹脂を用いた場合、高い効果が認められ、特にイオン交換基として−CH₂NH(CH₂CH₂NH)_nH基を有する弱塩基性陰イオン交換樹脂を用いた場合、更に顕著な効果が認められた。
【００１６】
【発明の効果】
本発明によれば、付着堆積物による経時的なノズル孔閉塞あるいは浴中ガイドの摩擦抵抗変化等がなく、繊度斑、染色性等の品質変動の小さい高品質なアクリル系繊維を長期間安定に製造することができる。[0001]
[Industrial application fields]
The present invention relates to a method for stably producing an acrylic fiber of good quality for a long period of time by spinning using a coagulation liquid treated with an ion exchange resin as a coagulation liquid when producing the acrylic fiber.
[0002]
[Prior art]
As a spinning method of acrylonitrile polymer , in addition to the dry spinning method , a wet spinning method in which spinning is directly performed from a nozzle into a coagulation bath, and the spinning yarn from the nozzle is once introduced into the coagulation bath after passing through the air. A dry and wet spinning method is known. The coagulating liquid used in the coagulation bath in the wet spinning method and the dry and wet spinning method is generally circulated and used repeatedly due to economic and environmental problems. However, it is known that in this coagulation liquid , low molecular weight polymers and polymerization residues are gradually dissolved during coagulation of the spun yarn due to repeated use. As the low molecular weight polymer and polymerization residue adhere to the surface of the nozzle hole or the guide in the bath immersed in the coagulation bath, they cause various problems in terms of processability and quality such as thread breakage. It is the cause.
[0003]
Therefore, the present inventors previously applied the ultrasonic vibration with the coagulated yarn from below the guide in the bath that changes the running direction of the yarn in the coagulation bath in the dry-wet spinning method. A technology for reducing frictional resistance and obtaining acrylic fibers with less fuzz and fineness unevenness has been developed (see JP-A-62-141111 and JP-A-10-219516). However, even with this method, temporary deposits can be removed. However, the dropped low molecular weight polymer is dissolved and accumulated again in the coagulation liquid, and precipitates again, so the above problem is fundamentally solved. It hasn't been done yet.
[0004]
Therefore, at present, it is necessary to replace the nozzle or the guide in the bath in order to meet the purpose of obtaining high-quality acrylic fibers stably for a long period of time and the repeated use of the coagulating liquid, which improves industrial production. It has become a big challenge.
[0005]
[Problems to be solved by the invention]
The object of the present invention is to remove the low molecular weight polymer, polymerization residue, etc. that adversely affect the spinnability and quality from the coagulating liquid that is repeatedly used by circulation , thereby reducing the deposits on the nozzle holes or the guide in the bath. An object of the present invention is to solve the above-mentioned conventional problems and to stably produce homogeneous acrylic fibers for a long period of time .
[0006]
[Means for Solving the Problems]
As a result of diligent research to achieve the above object, the present inventors reduced the influence of adhesion of low molecular weight polymers and the like in repeated use by treating and spinning a coagulating liquid to be used repeatedly with an ion exchange resin. The present inventors have found a method for stably producing homogeneous acrylic fibers for a long period of time.
That is, the gist of the present invention is to provide a coagulating liquid in a method for producing an acrylic fiber by spinning an acrylonitrile-based polymer by a wet spinning method or a dry-wet spinning method in which a coagulating liquid is repeatedly used. Is sent to a weakly basic anion exchange resin- filled column having a primary to tertiary amino group as an exchange group, and treated with the ion exchange resin. A low molecular weight polymer or the like eluted inside is captured by a specific ion exchange resin.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
(Ion exchange resin)
The ion exchange resin used in the present invention has a capturing ability for low molecular weight polymers and the like eluted in the coagulation liquid, and those that exhibit the effect of maintaining the quality of the coagulation liquid by capturing these eluates are used, for example, As shown in Examples, anion exchange resins , particularly weakly basic anion exchange resins having a primary to tertiary amino group as an exchange group are preferred, and more preferred is —CH ₂ NH (CH ₂ CH ₂ NH). It is a weakly basic anion exchange resin having an nH group (n: natural number) as an exchange group.
The amount of the ion exchange resin used is appropriately determined depending on the ion exchange resin capturing ability, the composition of the acrylonitrile polymer, the type of coagulation liquid, the concentration of the coagulation liquid, the amount of coagulation liquid used, and the like.
[0008]
(Acrylonitrile polymer)
The acrylonitrile-based polymer to which the production method of the present invention is applied is not particularly limited, but as a suitable polymer, it contains 100 to 50% by weight of acrylonitrile, and an unsaturated monomer 0 to copolymerizable therewith. An acrylic polymer composed of 50% by weight is exemplified. When the amount of acrylonitrile in the acrylonitrile-based polymer is 50% by weight or less, the dyeing vividness and color developability, which are the characteristics of acrylic fibers, are lowered, and other physical properties such as thermal properties are also lowered, which is not preferable. Examples of copolymerizable unsaturated monomers include acrylic acid, methacrylic acid, and derivatives thereof, vinyl acetate, acrylamide, methacrylamide, vinyl chloride, vinylidene chloride, and depending on the purpose, sodium vinylbenzene sulfonate and methallyl sulfonic acid. Ionic unsaturated monomers such as soda and acrylamidomethylpropane sulfonic acid soda can be used.
[0009]
As a method for producing the acrylonitrile-based polymer, known polymerization methods such as suspension polymerization and solution polymerization can be applied and are not particularly limited. The molecular weight of the acrylonitrile-based polymer is not particularly limited as long as the molecular weight is in a range usually used for the production of acrylic fibers, but the molecular weight is preferably in the range of 100,000 to 1,000,000.
[0010]
(Spinning stock solution)
The spinning dope is prepared by dissolving an acrylonitrile polymer in a solvent so as to have a concentration of 15% to 28% by weight. If the concentration is less than 15% by weight, the difference between the shape of the nozzle hole and the shape of the fiber cross section during solidification However, it is difficult to obtain the desired cross-sectional shape, which is not preferable. On the other hand, if the concentration exceeds 28% by weight, the stability with time of the spinning dope deteriorates and the spinning property is lowered, which is not preferable.
As the solvent, a commonly used solvent for an acrylonitrile-based polymer, for example, an organic solvent such as dimethylformamide, dimethylacetamide, dimethylsulfoxide, nitric acid, an aqueous rhodanate solution, an aqueous zinc chloride solution, or the like can be used.
[0011]
(Spinning method)
The spinning method of the present invention may be either a wet spinning method or a dry-wet spinning method in which a coagulation liquid is circulated and used repeatedly . A coagulating liquid which is treated with an ion exchange resin directly (wet spinning method) or through an air layer (dry wet spinning method), and containing a solvent of acrylonitrile polymer and water as a main composition coagulation bath consisting of coagulation liquid (hereinafter, simply referred to as the coagulation bath) to-out guide, and coagulated fiber was spun. The coagulation bath conditions are not particularly limited. For example, when dimethylacetamide is used as the solvent, the coagulation bath temperature is preferably 0 to 40 ° C. and the solvent concentration is 10 to 85%.
The obtained coagulated yarn is washed in hot water at 50 to 100 ° C. until the solvent content in the fiber becomes 1% or less, and stretched twice or more in hot water at 80 to 100 ° C. by applying an oil agent. After being dried, it is subjected to a dry heat treatment at a temperature of 120 to 180 ° C. to become an acrylic fiber. If necessary, it may be further subjected to a dry heat drawing treatment, relaxation or the like, whereby an acrylic fiber having a balanced mechanical property is obtained.
[0012]
【Example】
Hereinafter, the present invention will be described specifically by way of examples.
In the examples, the content of a low molecular weight polymer or the like dissolved in the coagulation bath is shown as the amount of evaporated to dryness. Dryness amount after 80 ° C. The coagulation liquid, at 2.7 kPa for 24 hours and concentrated, 60 ° C., was determined by measuring the weight 24 hours under reduced pressure to dryness at 600 Pa. In general, it can be interpreted that the higher the content, the greater the amount of deposits on the guide in the bath. Furthermore, the coagulation bath trip force exhibited tension on the coagulated fiber between the rolls taking over bath guide and coagulation bath and out. In general, the higher the tension, the higher the frictional resistance between the guide in the bath and the coagulated yarn. This dryness amount, with out coagulation bath tension, CV% as an indication of the fineness unevenness of the final fibers obtained showed M ratio as an index of dyeability. CV% was measured based on the JIS L-7.20A method using a USTER TESTER 3 / C manufactured by Zerbegger Worcester under the conditions of a measurement speed of 50 m / min and a twist number S twist of 200 T / m. The M rate is determined by scouring 200 g of knitted fabric made of fiber yarn by a known method, and then Astrazon Blue FRR 200 (cationic dye manufactured by Bayer) 0.35% by weight, dyeing temperature 95 ° C., dyeing temperature 60 minutes. The density of the dyed yarn obtained under the dyeing conditions is determined by visual evaluation in five levels (very light color, light color, medium color, dark color, extremely dark color), and the ratio of medium color is shown. The M ratio is high. It shows that the dyeing uniformity is high.
[0013]
Example 1-3 , Comparative Example 1-3
As the ion exchange resin, Diaion PK220, WK20, WA10, WA20, WA30 (all trade names) manufactured by Mitsubishi Chemical Corporation having the exchange groups shown in Table 1 were used. The ion exchange resin is packed in 100 L in a purification ion exchange column, the depth of the resin bed is about 750 mm, and the coagulating liquid used is fed to this column at a speed of 150 L / H, so that In the spinning method, the production amount of acrylic fiber was 60 kg / day, and the spinning operation was performed for 15 days.
A copolymer with an average molecular weight of 300,000 consisting of 93% acrylonitrile, 6% vinyl acetate and 1% sodium styrenesulfonate was dissolved in dimethylacetamide to prepare a spinning stock solution having a concentration of 25% by weight. The temperature was raised to. On the other hand, the distance from the spinneret having 60 circular holes to the coagulation bath liquid surface is set to 15 mm, and the above-described heated stock solution is extruded into the air from the spinneret, and the flow of the generated stock solution is changed. Immediately, the yarn was introduced into a coagulation bath consisting of 75% dimethylacetamide and 25% water, and the spun yarn was coagulated to form fibers. Next, the yarn that passed through the coagulation bath was led to a take-up roller having a speed of 50 m / min and pulled. After washing with water, primary stretching of 3.0 times in boiling water was performed, and after drying, secondary stretching of 2.0 times was performed on a 180 ° C. hot pin. Thereafter, the yarn was further subjected to a 7% relaxation treatment on a hot plate at 250 ° C. to obtain an acrylic filament having a single yarn fineness of 2.5 dtex (150 dtex / 60) as a filament bundle having a fineness of 150 dtex. Table 1 shows the results of measurement of the amount of evaporated and dried solids, the coagulation bath tension, the fineness unevenness (CV%) of the obtained fiber, and the M ratio in the spinning of each example.
[0014]
[Table 1]
[0015]
As is apparent from Table 1, the use of the production method of the present invention improves the cleaning of the coagulation liquid, fineness spots, and the dyeing uniformity effect. When a weakly basic anion exchange resin is used as the ion exchange resin, a high effect is recognized, and in particular, a weakly basic anion having a —CH ₂ NH (CH ₂ CH ₂ NH) _n H group as an ion exchange group. When an exchange resin was used, a more remarkable effect was recognized.
[0016]
【The invention's effect】
According to the present invention, high-quality acrylic fibers with little quality fluctuations such as fineness unevenness and dyeability are stable for a long period of time without obstruction of nozzle holes due to deposited deposits or changes in friction resistance of guides in the bath. Can be manufactured.

Claims

In a method for producing acrylic fiber by spinning an acrylonitrile-based polymer by a wet spinning method or a dry-wet spinning method in which a coagulating liquid is repeatedly used in a circulating manner, the coagulating liquid is classified into primary to tertiary amino groups. A process for producing an acrylic fiber, wherein the liquid is sent to a column filled with a weakly basic anion exchange resin using as an exchange group and treated with the ion exchange resin.

The method for producing an acrylic fiber according to claim 1 , wherein an acrylic filament is produced using a dry and wet spinning method.