JP3708030B2 - Polyketone fiber, polyketone fiber twisted product and molded article thereof - Google Patents

Description

【０００９】
本発明のポリケトン繊維は、繰り返し単位の９５〜１００質量％が１−オキソトリメチレンから構成されるポリケトンである。
繰り返し単位中の１−オキソトリメチレンの割合が高いほど分子鎖の規則性が上がり、高結晶性、高配向度の繊維が得られるようになり、結果として高強度・高弾性率、高耐熱性の繊維が得られる。
このため、１−オキソトリメチレンの割合は好ましくは９７〜１００質量％、最も好ましくは１００質量％であることが望ましい。
また、必要に応じてプロペン、ヘキセン等のエチレン以外のオレフィンやメチルメタクリレート、アリルスルホン酸ナトリウム等の不飽和炭化水素を有する化合物を共重合してもよい。
【００１０】
ポリケトンの重合度は、極限粘度で２〜１０であることが好ましい。
極限粘度が２未満である場合はポリケトン繊維の強度や紡糸性が低下する。また、極限粘度が１０を超える場合に重合コスト、紡糸コストが高くなり実用的な価格でポリケトン繊維を得ることが困難となる。
このため、ポリケトンの重合度としては、極限粘度が２〜１０の範囲、さらに好ましくは３〜６の範囲であることが望ましい。
【００１１】
本発明のポリケトン繊維は、高強度・高弾性率、高耐熱性の特性を発現するために結晶化度、結晶配向度が特定範囲にあることが必要である。
結晶化度(a) は結晶構造の量比を表す構造パラメーターであり、この値が６０％未満では、ポリケトン繊維が十分な強度、弾性率、耐熱性を発現することが出来ない。結晶化度(a) は高いほど高強度、高寸法安定性、高耐熱性、高耐薬品性となるため、６０％以上であることが必要であり、より好ましくは７０％以上、特に好ましくは８０％以上であることが望ましい。
また、結晶配向度 (b)は、繊維中の分子鎖が繊維軸方向に配列する規則性の度合いを表す構造パラメーターであり、この値が９０％未満では分子鎖の配列が不十分で弾性率が低く、荷重に対する寸法安定性が不十分となる。
結晶配向度 (b)は高いほど高弾性率で寸法安定性に優れる繊維となるため、９０％以上であることが必要であり、より好ましくは９５％以上、特に好ましくは９７％以上であることが望ましい。
また、本発明のポリケトン繊維は引張強度に優れた繊維である。引張強度(c) が高いほど、高強度の撚糸物が得られるほか、延伸時や撚糸時の張力による毛羽、断糸が起こりにくくなる。
このため、引張強度(c) としては１０ｃＮ／ｄｔｅｘ以上であることが必要であり、より好ましくは１３ｃＮ／ｄｔｅｘ以上、さらに好ましくは１５ｃＮ／ｄｔｅｘ以上、特に好ましくは１７ｃＮ／ｄｔｅｘ以上であることが望ましい。
【００１２】
高強度のポリケトン繊維は繊維軸方向に高度に配向したものであるため、撚糸を行った場合、▲１▼ 繊維軸方向以外の方向の力を受けて強度が低下する問題、▲２▼繊維表面同士の擦過によって単糸が切れたりフィブリルが発生して単糸間で絡まりあい工程通過性、品位が低下する問題が頻発するようになる。
本発明の最も重要な技術課題は、高度に結晶化、配向した高強度のポリケトン繊維であっても、▲１▼や▲２▼の問題が起こらない繊維を提供することであり、本発明者らはこれらの問題を解決するには、(i) 単糸膠着がないこと、(ii)繊維−繊維間の摩擦が小さいこと、(iii) 単糸繊度が小さいこと、(iv)毛羽やフィブリル状物がないことが重要であり、特に(i) と(ii)を同時に満足するポリケトン繊維は、撚糸による強力低下や工程通過性の低下に対して極めて優れた特性を示すことを見いだした。
【００１３】
本発明のポリケトン繊維の単糸膠着については、下式(4) で定義される単糸膠着率(d) が３０％以下である。
単糸膠着率(d) ＝［１−（見かけの単糸数／単糸数）］×１００（％） ・・・(4)
（ここで、単糸膠着率(d) とは、マルチフィラメント中の膠着した単糸の数的割合を表す値である。）
具体的な例で説明すると、１０個のホール数を持った紡糸口金を用いて製造された繊維において、２本の単糸が膠着しているものが２組あるとすれば、単糸数は１０で、見かけの単糸本数は８となり、単糸膠着率(d) は２０％となる。
単糸膠着率(d) が３０％より大きい場合に、繊維が硬くなるほか、単糸に無理な力がかかりやすくなって撚糸時に毛羽、断糸が発生するし、撚糸後の強度が低下する等問題が顕在化する。
単糸膠着率(d) としてはさらに好ましくは２０％以下であり、特に好ましくは１０％以下、最も好ましくは０％である。
【００１４】
また、繊維−繊維間の摩擦が小さいことも重要であり、これを達成するにはポリケトン繊維に０．１〜２０質量％の仕上げ剤を含有せしめて、繊維の集束・制電による無駄な接触抵抗の低減、油膜の形成による繊維表面の摩擦係数の低減をすることが極めて有効である。
仕上げ剤の成分については特に制限はなく、例えば特願２０００−１９９９５号に記載の仕上げ剤を使用することができる。
具体的には、仕上げ剤の構成成分として、(1) エステル化合物、(2) 鉱物油、(3) ポリエーテルから選ばれた少なくとも１種を必須成分とし、その合計量が仕上げ剤中に３０〜１００重量％、好ましくは５０〜８０重量％含有されている仕上げ剤が好ましい。
このような仕上げ剤を付与することにより、ポリケトン繊維の表面に強固な油膜が形成し、この油膜によって繊維表面が滑るので、延伸時や撚糸時に繊維が短期間に摩耗することがない。
【００１５】
エステル化合物(1) は、ポリケトン繊維表面の平滑性・耐摩耗性を向上させる成分であり、具体例としては、ステアリン酸オクチル、オレイン酸ラウリル等が挙げられ、その分子量は平滑性、工程通過性の観点から５００〜３０００が好ましい。
鉱物油(2) もまた、ポリケトン繊維表面の平滑性・耐摩耗性を向上させる成分であり、パラフィン系又はナフテン系のものが好ましく、その粘度は３０℃におけるレッドウッド粘度が４０〜８００秒が好ましい。
ポリエーテル(3) は、その仕上げ剤が繊維表面に形成する油膜の強度を高める働きがあり、具体的には、プロピレンオキシドとエチレンオキシドの共重合してなるポリオレフィンオキシドを主成分とするポリエーテルが好ましく、その分子量としては耐摩耗性の観点から１５００〜２００００が好ましい。
【００１６】
また、本発明で用いる仕上げ剤は、乳化剤（例えばポリオキシエチレンステアリルエーテル等）や制電剤（アニオン性界面活性剤等）、酸化防止剤を含有することが好ましい。
以上のような仕上げ剤の付着率(e) は、０．３質量％未満であると摩擦抵抗の低減効果が不十分であり、また１５質量％を超えると油膜同士の接触抵抗が増大し逆に繊維−繊維間の摩擦が増大するため、仕上げ剤の付着率(e) はポリケトン繊維に対して０．３〜１５質量％が好ましく、より好ましくは０．５〜１０質量％、さらに好ましくは１〜５質量％である。
仕上げ剤はそのままストレートで付与して、あるいは、水に分散させてエマルジョン仕上げ剤として繊維に付着させることができる。
特に、単糸数の多いポリケトン繊維では繊維間に均一に油剤を浸透させることが重要であり、浸透剤としてエステル基やケトン基、エーテル基を有する活性剤を併用するとポリケトン繊維間に仕上げ剤を均等に分散せしめて付与することが出来て効果的である。
【００１７】
また、繊維−繊維間の抵抗を低減せしめる手段としては繊維の断面を摩擦しにくい形状にすることが効果的である。
本発明のポリケトン繊維の断面形状は特に制限はなく、円、楕円、三角、四角、菱形、アルファベット形、星形、中空等目的に応じて選定出来るが、極めて高い撚糸強力利用率、撚糸時の工程通過性を得るためには円形（丸断面または楕円）が望ましく、さらに真円率(g)が１．０〜１．２である丸断面であることがより好ましい。
ここで、真円率(g)とはポリケトン繊維断面の最小外接円半径／最大内接円半径から求められる値であり、１．０に近いほど真円に近いことを意味する。
真円率(g)は１．０に近いほど、単糸間の接触面積が小さくなり繊維−繊維間の摩擦抵抗が減少し、撚糸物の耐疲労性、撚糸強力利用率が高くなり、撚糸時の工程通過性が良くなる。
真円率(g)は、より好ましくは１．０〜１．１であることが望ましい。
【００１８】
本発明のポリケトン繊維は、仕上げ剤付与および繊維断面形状の設計によって繊維−繊維間の動摩擦係数(f) （以下μと略することがある）が０．０１〜０．５とすることが望ましい。
μが０．５を超える場合、撚糸時に負荷が掛かり毛羽や断糸が頻発し、撚糸強力利用率も大きく低下する。また、μが０．０１未満の場合、マルチフィラメントの集束性が低下し、たるみが生じて撚糸強力利用率(h) および品位が低下する他、加工性・取り扱い性が悪くなる。
このため、μの値としては好ましくは０．０３〜０．４、より好ましくは０．０５〜０．３であることが望ましい。
【００１９】
さらに、本発明のポリケトン繊維には毛羽やフィブリル状物が少ないことは当然重要である。
ここで毛羽とは、単糸が切断して生成した片端が拘束されていない繊維である。
また、フィブリル状物とは、衝撃や摩耗によって剥離生成する、直径０．０１〜数μｍ、長さ１μｍ〜数十ｍｍのポリケトンからなる円筒状物である。
これら毛羽やフィブリル状物はポリケトン繊維の強度を低下させるばかりでなく、隣接する単糸や付近の２本以上の単糸と絡み合って結節点を形成し撚糸強力利用率(h) を低下させる。
毛羽数としては、好ましくは１個／１０ｍ以下、より好ましくは１個／１００ｍ以下、さらに好ましくは１個／１００００ｍ以下であることが望ましい。
また、フィブリル数としては繊維束を光学顕微鏡で観察した際に１００視野中１個以下、好ましくは１００視野中０個であることが望ましい。
【００２０】
ポリケトン繊維の単糸繊度は特に制限はないが、撚糸強力利用率および工程通過性の観点から０．１〜１０ｄｔｅｘであることが望ましい。
単糸繊度が０．１ｄｔｅｘ未満の場合、紡糸時や撚糸時に毛羽や断糸が起こり製品の品位および工程通過性が低下する。また、単糸繊度が１０ｄｔｅｘを超えると、強撚時の撚糸強力利用率が低くなる問題がある。
このため、単糸繊度としてはより好ましくは０．５〜５ｄｔｅｘ、特に好ましくは０．８〜２ｄｔｅｘであることが望ましい。
また、ポリケトン繊維の総繊度は用途や使用部位により異なるため特に制限はないが、通常は１０〜１００００ｄｔｅｘ、好ましくは３００〜３０００ｄｔｅｘである。
【００２１】
本発明のポリケトン繊維は、高強度でありながら単糸膠着がなく、仕上げ剤を有し且つ動摩擦係数(f) μが小さく撚糸性に優れた繊維であるが、撚糸性の具体的な範囲として、撚り係数Ｋが１００００となるよう撚糸した際の撚糸強力利用率(h) が６５％以上であることが望ましい。
なお、本発明において、撚糸強力利用率(h) とは撚糸後のポリケトン撚糸物の強力を撚糸前のポリケトン繊維の強力で除した１００分率である。
例えば、複数本のポリケトン繊維を撚り合わせる場合には、撚糸後のポリケトン撚糸物の強力を、撚り合わせたポリケトン繊維の強力の和で除した１００分率を撚糸強力利用率(h) とする。
また、Ｋは下式(1) で定義される撚糸物の撚り係数である。
Ｋ＝Ｙ×Ｄ^0.5 （Ｔ／ｍ・ｄｔｅｘ^0.5） ・・・(1)
〔ただし、式(1) において、Ｙはポリケトン撚糸物１ｍあたりの撚り数（Ｔ／ｍ）、Ｄはポリケトン撚糸物の総表示繊度（ｄｔｅｘ）である。〕
【００２２】
ここで、総表示繊度とは撚糸に用いた全ポリケトン繊維の繊度の和である。
例えば、１６７０ｄｔｅｘのポリケトン繊維を３本撚り合わせた場合、撚糸物の総表示繊度は５０１０ｄｔｅｘ（１６７０／３）となる。複数のポリケトン繊維を撚り合わせ、下撚り、上撚り等の多段の撚りを加えた場合、最後に加えた撚りの回数を撚り数Ｙとして撚り係数を算出する。
タイヤコードやベルト、ホース等のゴム補強材料、あるいはロープやネット、漁網等の用途に用いる場合、撚り係数Ｋが１００００〜３００００の範囲の撚糸物を用いることが多い。
ポリケトン繊維においては撚糸強力利用率(h) は撚り係数Ｋが大きくなるに連れて低下し、Ｋが１００００におけるポリケトン繊維の撚糸強力利用率(h) が６５％未満の場合、Ｋが１００００〜３００００における撚糸強力利用率(h) は６５％よりさらに小さくなる。
このため、ほとんどの用途において高強度のポリケトン繊維を用いても撚糸物の強度は実用的な強度を有さなくなるほか、撚糸工程時に毛羽や断糸等のトラブルが多発し、工程通過性や品位の低下が起こる。
このため、撚り係数Ｋが１００００における撚糸強力利用率(h) は６５％以上であることが好ましく、より好ましくは７５％、さらに好ましくは８０％以上であることが望ましい。
【００２３】
また、ポリケトン繊維の撚糸強力利用率(h) は撚糸条件（用いるポリケトン繊維の繊度、撚糸数等）により大きく変化し、ポリケトン繊維の繊度が小さいほど、また、撚糸数が少ないほど撚糸強力利用率(h) が高くなる。
このため、本発明のポリケトン繊維は、撚り係数Ｋに対して、下式(2) の範囲内にあることが好ましい。
撚糸強力利用率(h) （％）≧１００−Ｋ／３００ ・・・(2)
【００２４】
ポリケトン繊維は、タイヤやベルト、ホース等のゴム補強材料等の高い荷重を受ける用途への展開が期待されている。これらの用途では、通常下撚りをした繊維を２本あるいは３本以上撚り合わせ、更に下撚りとは逆方向に上撚りを加えて撚糸物として、得られる撚糸物には高い強力が要求される。
本発明者らは、上述の単糸膠着率、仕上げ剤の組成・付与方法、繊維断面形状、フィブリルの抑制、単糸繊度を最適な条件で行うことによって、従来のポリケトン繊維を凌駕する極めて優れた撚糸強力利用率(h) を有するポリケトン繊維を見出した。
この高撚糸強力利用率のポリケトン繊維は、撚糸強力利用率(h) が下式(3) の範囲にあり、ゴム補強材料やロープ等の高荷重のかかる用途へ極めて有用なものである。
撚糸強力利用率（％）≧１００×（１−４．７９×１０^-9×Ｋ^1.78）・・・(3)
上記式(3) で示される撚糸強力利用率(h) の値としては、具体的には撚り係数Ｋが５０００の時に９８％以上、撚り係数Ｋが１００００の時に９４％以上、撚り係数Ｋが１５０００の時に８７％以上、撚り係数Ｋが２００００の時に７８％以上、撚り係数Ｋが２５０００の時に６８％以上であり、甘撚りから強撚まで高い撚糸強力利用率(h) を維持するものである。
【００２５】
また、本発明のポリケトン繊維は短繊維として用いてもよい。
ポリケトン短繊維は、上述のポリケトンフィラメントを糸長方向にカットすることで得られる。
短繊維の長さについては特に制限はなく、使用環境、使用目的に応じて任意の長さにカットすれば良いが、通常は短繊維の平均長で０．１〜１００ｍｍ、好ましくは０．５〜５０ｍｍの長さのものが好適に用いられる。
なお、本発明において短繊維の平均長Ｌは、１本の短繊維の長手方向（繊維軸方向）の長さを繊維長Ｌ_iとして、任意に選ばれた１００本の短繊維の平均の長さとして下式(5) で算出される。
このような短繊維は、コンクリートなどの補強材料として、或いは紡績糸として編物やロープなどの用途に有用である。
【数１】

【００２６】
本発明のもう一つの形態は、上述の高強度・高弾性率で優れた撚糸性を有するポリケトン繊維を撚糸して得られるポリケトン撚糸物である。
本発明において撚糸物とは、繊維が１０回／ｍ以上の割合で撚りを加えられてなる繊維材料を意味し、繊維材料に対して１００質量％未満であれば樹脂や接着剤、油等の繊維材料以外の物質を含有していてもよい。
本発明の撚糸物は、撚糸物を構成する繊維材料の少なくとも一部に本発明のポリケトン繊維を含有するものである。
【００２７】
撚糸物に占めるポリケトン繊維の割合は高ければ高いほど高強力で高力学特性、高耐熱性となるため、好ましくは撚糸物の５０〜１００質量％、より好ましくは撚糸物の８０〜１００質量％が本発明のポリケトン繊維であることが望ましい。
中でも、繊維材料の１００質量％が本発明のポリケトン繊維から構成されるポリケトン撚糸物は高強力繊維材料として有用である。
特に、撚糸強力利用率(h) が下式(3) の範囲のポリケトン撚糸物は、広範な撚糸範囲において極めて高い力学特性を示し、従来のポリケトン撚糸物では得られなかった高強力を有するものである。
撚糸強力利用率(h) （％）≧１００×（１−４．７９×１０^-9×Ｋ^1.78）・・・(3)
【００２８】
本発明のポリケトン撚糸物の強度（強力）は、撚糸条件、用途、使用部位等により異なり一概に定義することは難しいが、撚り係数Ｋが１００００の場合で好ましくは１０ｃＮ／ｄｔｅｘ以上、より好ましくは１３ｃＮ／ｄｔｅｘ以上、特に好ましくは１５ｃＮ／ｄｔｅｘ以上であり、撚り係数Ｋが２００００の場合で好ましくは８ｃＮ／ｄｔｅｘ以上、より好ましくは１０ｃＮ／ｄｔｅｘ以上、特に好ましくは１２ｃＮ／ｄｔｅｘ以上であることが望ましい。
ここで、撚糸物の強度は、撚糸物の強力を撚糸に用いた繊維の総表示繊度で除した値である。
【００２９】
また、必要に応じてポリケトン繊維以外の繊維（例えば、ポリエステル繊維、アラミド繊維、セルロース繊維、ポリアミド繊維、ポリビニルアルコール繊維等）を含有していてもよい。
ポリケトン撚糸物の撚糸形態に特に制限はなく、撚り糸の種類としては例えば、片撚り糸、もろ撚り糸、ピッコもろ撚り糸、強撚糸などが挙げられ、撚糸の本数も１本撚りであっても、２本撚り、３本撚りあるいは４本以上の多本撚りであってもよい。
撚糸物の太さは用途に応じて適宜選定され、ゴム補強材料用途においては直径０．１〜１０ｍｍ、ロープやネット用途においては直径１〜１００ｍｍのものが好適に用いられる。
撚糸数についても用途、部位等に応じて適宜選定出来るが、上述の撚り係数Ｋが１００〜５００００の範囲が好適に用いられ、より好ましくは１０００〜３００００の範囲が好適に用いられる。
【００３０】
また、本発明のポリケトン撚糸物をゴム補強材料として用いる場合には、ゴムとの接着性を高める目的で接着剤を付着せしめることがある。
接着剤の種類は特に制限はなく、従来公知のものをそのまま、あるいは目的に応じて条件を変えて使用してもよい。
接着剤としては、レゾルシン−ホルマリン−ラテックス（ＲＦＬ）樹脂が好適に用いられ、ＲＦＬ樹脂の付着率は繊維に対して０．１〜１０質量％が好ましく、より好ましくは１〜７質量％が望ましい。
【００３１】
本発明のポリケトン繊維およびポリケトン撚糸物を含有する成形体は高い力学特性を有し、また、単糸膠着や毛羽が少なく、繊維−繊維間の摩擦係数が低いことから耐疲労性にも優れるものとなる。
本発明において成形体とは、ロープ、織物、編物、ネット、網等の繊維製品はもちろんのこと、タイヤ、ベルト、ホース、無限軌道体等のゴム製品、ＦＲＰ等の樹脂製品等の人工物を意味する。
【００３２】
次に、本発明のポリケトン繊維およびポリケトン撚糸物の製造方法について説明する。
本発明のポリケトン繊維の製造法は特に限定されないが、取扱性、毒性、引火性、ポリケトンの変性、コスト等の観点から金属塩溶液を溶剤とする湿式紡糸法が好適である。
以下、金属塩溶液を溶剤とする湿式紡糸法による本発明のポリケトン繊維の製造法を説明する。
ポリケトンの溶解に用いる金属塩溶液はポリケトンを溶解する能力を有するものであれば特に制限はなく、例えばハロゲン化亜鉛、ハロゲン化アルカリ金属塩、ハロゲン化アルカリ土類金属塩等が挙げられる。
金属塩溶液は、爆発性、取扱性、コストの観点から水溶液が好ましく、１０〜８０質量％のハロゲン化亜鉛（塩化亜鉛、ヨウ化亜鉛等）を含有する水溶液が特に好適に用いられる。また、上記の金属塩以外の化合物を本発明の目的を阻害しない範囲で混合しても良い。
【００３３】
金属塩溶液の塩濃度は５０〜８０質量％であることが好ましい。
５０質量％より低い塩濃度の場合や、または８０質量％より高い塩濃度では、紡糸が不安定になる。
塩濃度は下式(6) で定義される値である。
塩濃度（質量％）＝［塩の質量／（塩の質量＋溶媒の質量）］×１００・・・ (6)
金属塩溶液に溶解するポリケトンのポリマー濃度は、溶解性、紡糸性、製造コストの観点から０．１〜４０質量％が好ましいが、より好ましくは３〜２０質量％である。
ポリマー濃度は、下式(7) で定義される値である。
ポリマー濃度（質量％）＝［ポリマー質量／（ポリマー質量＋金属塩溶液の質量）］×１００ ・・・(7)
【００３４】
得られたポリケトン溶液を必要に応じてフィルターで濾過した後、紡糸口金から凝固浴へ押出し、繊維状に成形する。押出し時のポリケトン溶液の温度と凝固浴の温度の差が大きいときは、紡糸口金から出た繊維状物が空気相を経て浴に入る方法、いわゆるエアギャップ法が好ましい。
凝固浴の組成及び温度について特に限定はないが、溶剤の回収コストを下げる点で、溶剤に用いた塩の水溶液であることが好ましい。
凝固浴外へ引き上げられた繊維状物を水洗し、必要に応じて塩酸、硫酸、リン酸等を含んだｐＨが４以下の水溶液を用いて金属塩を実質的に除去する。
特に、金属塩溶液が、塩濃度が５９〜６４質量％である塩化カルシウム／塩化亜鉛（質量比は６８／３２〜６１／３９）の水溶液であり、紡糸口金から押出すときのポリケトン溶液の温度が６０〜１５０℃、凝固浴の温度が−５０〜２０℃の場合、単糸膠着率(d) を下げる効果が大きくなることに加え、強度を高める効果もあり、好ましい。
【００３５】
次に、繊維に含まれた水を除去するために乾燥を行う。
乾燥方法に特に限定はなく、トンネル型乾燥機、ロール加熱機やネットプロセス型乾燥機等の公知の設備を用い、延伸しながら、定長下で或いは収縮させながら乾燥を行うことができる。
乾燥温度は特に制約はないが、好ましくは１００℃〜２６０℃、より好ましくは１２０℃〜２５０℃、最も好ましくは１５０℃〜２４０℃である。
次いで、この乾燥糸を引き続き１段もしくは２段以上の多段延伸により熱延伸を行う。
【００３６】
延伸は何段で行ってもよく、多段延伸を行う場合には延伸温度を徐々に高くしていく方法が好ましい。延伸温度は１５０℃〜ポリケトン繊維の融点であることが好ましい。
１５０℃より低い温度では高強度・高弾性率のポリケトン繊維を得ることが困難であり、また、ポリケトン繊維の融点より高い温度では延伸時に糸が溶融して切断する。
延伸性および繊維物性の観点から１５０℃〜ポリケトン繊維の融点が好ましく、より好ましくは２００℃〜ポリケトン繊維の融点−５℃で延伸することが望ましい。
また、得られるポリケトン繊維の力学特性の観点から、全延伸倍率は好ましくは１０倍以上、より好ましくは１５倍以上とすることが望ましい。
熱延伸装置としては、加熱ロールまたは加熱プレート上あるいは加熱気体中を走行させる方法や、走行糸にレーザーやマイクロ波、赤外線を照射する等の従来公知の装置をそのままあるいは改良して採用することができる。
【００３７】
金属塩を用いる湿式紡糸法においては、乾燥工程で単糸膠着が発生し易いため、単糸膠着を防止する方策を施すことが極めて重要である。
単糸膠着を防ぐ方法としては、繊維に外力を加え単糸間をずらす方法、膠着が起こる前の繊維表面に離形剤を付与する方法、単糸同士の静電反発力により単糸間をずらす方法等が挙げられ、特に、得られる繊維の物性および工程通過性の観点から繊維に外力を加え単糸間をずらす方法、繊維表面に離形剤を付与する方法が好適に用いられる。
【００３８】
単糸間のずれを生ずる外力を加える場合、乾燥工程および／または延伸工程終了までのいずれかの段階で１回または複数回にわたり外力を加えられるが、この際に水分率が０〜４０質量％である繊維を処理することが重要である。
なお、本発明において水分率は次式(8) で定義される。
水分率（質量％）＝［（残水繊維質量−絶乾繊維質量）／残水繊維質量］×１００ ・・・(8)
ここで、絶乾繊維質量とは１０５℃で５時間乾燥し、水分を完全に除去したときの繊維質量である。
繊維の水分率が４０質量％より高い場合、単糸間のずれを生ずる外力を加えたときに、単糸断面が変形したり、繊維に傷が付いたり、たるみが起こる等の問題が生じやすく、水分率を３０質量％以下とすることがより好ましい。
一方、水分率が０〜１質量％と低い場合、繊維−繊維間や繊維−製造装置間の摩擦により静電気が発生し易いため、装置に導電性の材料を用いることや、また、制電効果のある油剤を付与する等の静電気除去の方策を併せて講じることが望ましい。
【００３９】
単糸間のずれとは、相接する単糸同士の相対的な位置関係が変化すること（相接する単糸間の側面が離れること、相接する単糸間の側面に沿って滑ること等）であり、これにより単糸間の膠着を防いだり、あるいは、一旦発生した膠着を取り除くことができ、単糸膠着率の低いポリケトン繊維が得られる。
単糸間のずれを生ずる外力としては、繊維をしごくことや繊維に振動を与えることが有効である。
具体的には、ピンガイドやロールに通して繊維をしごく方法、超音波発生機で繊維を振動させる方法、繊維に圧縮気体を吹き付ける方法等が挙げられる。
単糸断面の変形や傷が生じ難く真円率(g)の高い繊維が得られ、また、操作性が良く、単糸膠着率の低い繊維が得られ易いという点で繊維に圧縮気体を吹き付ける方法が好適に用いられる。
圧縮気体の組成は特に制限はないが、安全性、取り扱い性の観点から空気、窒素が好ましく、空気が最も好ましい。
【００４０】
繊維を傷つけることなく単糸膠着率(d) の低いポリケトン繊維を得るためには、繊維にかかる張力と圧縮気体の吹き付ける速度を適正な範囲とすることが重要である。
具体的には、繊維にかかる張力を０〜１ｃＮ／ｄｔｅｘの範囲とし、吹き付ける速度を０．１〜１００ｍ／秒、好ましくは１０〜５０ｍ／秒の範囲とする。
単糸膠着率(d) が高い場合には、繊維に掛かる張力を下げること、および気体の吹き付け速度を速くすることが効果的である。
圧縮気体を吹き付ける装置、方法や吹き付け孔の形状については特に制限はなく、インターレーサーや仮撚りノズル等の従来公知の圧気処理装置や圧気配管の先端に任意の形状（丸型や楕円型、矩形、長方形等）の孔を取り付けたものでもよい。
【００４１】
単糸膠着が発生する前に繊維表面に離形剤を塗布する場合、離形剤はその後の乾燥、熱延伸で膠着を防止する作用のあるものであれば特に制限はない。
なお、本発明において、離形剤とは２本の平行に位置するポリケトン繊維表面に離形剤化合物を塗布した後に、２本のポリケトン繊維が繊維軸方向に渡って接合するように配列し、２２５℃で１分間の定長熱処理を行った場合に、ポリケトン繊維同士が容易に解繊する作用のある化合物を離形剤とする。
このような離形剤の例としては、例えば非水溶性の粒子状物（金属酸化物微粒子、金属微粒子、シリコン系化合物微粒子、フッ素系化合物微粒子）、非水溶性の有機物（鉱物油、高分子量エステル化合物、高分子量エーテル化合物）およびその分散液等が挙げられ、ポリケトン繊維間への均一分散や取り扱い性の観点から金属酸化物微粒子、シリコン系微粒子を主成分とする微粒子分散液が好適に用いられる。
微粒子分散液の平均粒径としては、０．１〜１００μｍが好ましく、より好ましくは０．２〜１０μｍであることが望ましい。微粒子分散液の分散媒体は取扱性、安全性の観点から水が好ましい。
【００４２】
また、離形剤の付着量はポリケトン繊維に対して０．１〜２０質量％とすることが好適である。
離形剤の付着量が０．１質量％未満の場合、十分な単糸膠着防止効果が得られず、また２０質量％を超える場合には得られるポリケトン繊維の物性が低下するほか、延伸性にも悪影響を及ぼす。
このため、離形剤の付着量としては好ましくは０．３〜１０質量％、より好ましくは０．５〜５質量％とすることが望ましい。
離形剤を付与する場合重要な点は、洗浄工程〜乾燥工程終了のいずれかの段階でポリケトン繊維の水分率が４０％を超える段階で離形剤を付与することである。
【００４３】
水分率が４０％以下となると、単糸膠着が発生し始め離形剤を付与しても十分な単糸膠着防止効果が得られない。このため、離形剤の付与はポリケトン繊維の水分率が４０％を超える段階で行うことが必要であり、より好ましくは水分率６０％以上、さらに好ましくは水分率１００％以上の段階で付与することが望ましい。
また、離形剤の付与が凝固完了前の場合、単糸内部に離形剤が入り込み繊維物性が極端に低下するため、酸洗浄工程入口以降で行うことが望ましく、より好ましくは水洗工程入口以降、さらに好ましくは水洗工程終了後に付与することが望ましい。
離形剤の付与は１段で行っても、また、多段で行っても良く、単糸膠着を起こさない範囲であれば離形剤にその他の成分を混合してもよい。
【００４４】
また、単糸膠着防止手段とは別に、乾燥工程終了後〜熱延伸終了の任意の段階で仕上げ剤を付与し、μを低減することが必要である。仕上げ剤の付与は１回もしくは複数回行っても良く、熱延伸工程前や熱延伸工程途中で付与してもよい。仕上げ剤の組成は特に限定されず、ストレートで付与しても、また、溶剤で希釈して、あるいはエマルジョンやサスペンジョンとして供給することが出来る。熱延伸終了後に水性溶液や水性エマルジョンや水性サスペンジョンとして仕上げ剤を付与する場合には、繊維間に残存する水分によりμが増大し撚糸強力利用率(h) が低下することがあるため、仕上げ剤付与後に水分を乾燥する工程を設けることが望ましい。
仕上げ剤の付与装置は特に限定されず、ノズル給油、ロール給油等従来公知の装置をそのまま、あるいは目的に応じて修正して用いることが出来る。
【００４５】
また、延伸工程中の毛羽やフィブリル状物の発生を抑制するために、延伸工程中に繊維と接触する装置（速度規制ロールを除く）はポリケトン繊維との摩擦係数の小さい材質のものを用いることが望ましく、具体的には繊維−金属間の動摩擦係数が０．１以下、好ましくは０．０１〜０．０８の材質（例えば、表面粗度の大きい金属酸化物や金属）が好ましい。また、これら材料は導電性とし、摩擦により発生する静電気を徐電することが望ましい。
【００４６】
熱延伸工程終了後のポリケトン繊維をそのまま連続して、あるいは、一旦巻き取った後に撚糸を行う。
撚糸数は用途、使用環境に応じて選定され、一般的には、上述の撚り係数Ｋが１０００〜３００００の範囲で撚糸される。
撚糸物の力学物性、品位の観点から撚糸張力としては、下撚り張力／上撚り張力共に０．０１〜０．２ｃＮ／ｄｔｅｘとすることが好ましい。
【００４７】
ゴム補強用繊維とする場合には撚り合わされたポリケトン撚糸物を、引き続き濃度１０〜３０質量％のＲＦＬ液を付着させ、樹脂を固着させる工程（いわゆるＤｉｐ処理工程）を通す。
ＲＦＬ液の好ましい組成としては、レゾルシンを０．１〜１０質量％、ホルマリンを０．１〜１０質量％、ラテックスを１〜２８質量％であり、より好ましい組成としてはレゾルシン０．５〜３質量％、ホルマリン０．５〜３質量％、ラテックス１０〜２５質量％が望ましい。
また、ＲＦＬ液の乾燥温度としては好ましくは１００〜２５０℃、より好ましくは１４０〜２００℃であり、少なくとも１０秒、好ましくは２０〜１２０秒間乾燥熱処理することが望ましい。
【００４８】
乾燥後の撚糸物は、引き続きヒートセットゾーンおよびノルマライジングゾーンにて熱処理を受ける。
ヒートセットゾーンでの温度、張力、時間はそれぞれ、１５０〜２５０℃、０．１〜０．７ｃＮ／ｄｔｅｘ、１０〜３００秒とすることが望ましい。また、ノルマライジングゾーンでの温度、張力、時間はそれぞれ、１５０〜２５０℃、０．０１〜０．３ｃＮ／ｄｔｅｘ、１０〜３００秒とすることが望ましい。
【００４９】
以上の方法で得られたポリケトン繊維は高強度・高弾性率、および高撚糸強力利用率の優れた力学物性を有し、撚糸物とした際には原糸の強度を高いレベルで維持し、耐疲労性に優れる高強度繊維材料として有用である。特に、タイヤコードやホース、ベルト等のゴム補強材料、ロープ、ネット、漁網等の繊維を強撚して用いる産業資材用分野において極めて有用である。
【００５０】
【実施例】
本発明を、下記の実施例などにより更に詳しく説明するが、それらは本発明の範囲を限定するものではない。
実施例の説明中に用いられる各測定値の測定方法は次の通りである。
(1) 極限粘度
極限粘度［η〕は次の定義式に基づいて求められる値である。
［η〕＝ｌｉｍ（Ｔ−ｔ）／（ｔ・Ｃ） ［ｄｌ／ｇ］
Ｃ→０
（定義式中のｔ及びＴは、純度９８％以上のヘキサフルオロイソプロパノール及び該ヘキサフルオロイソプロパノールに溶解したポリケトンの希釈溶液の２５℃での粘度管の流過時間である。また、Ｃは上記１００ｍｌ中のグラム単位による溶質質量値である。）
(2) 結晶化度(a)
示差熱測定装置Ｐｙｒｉｓ１（商標；パーキンエルマー社製）を用いて下記条件で測定を行う。サンプルは糸長を５ｍｍにカットした短繊維を用いる。
サンプル質量： １ｍｇ
測定温度 ： ３０℃→３００℃
昇温速度 ： ２０℃／分
雰囲気 ： 窒素、流量＝２００ｍＬ／分
得られる吸発熱曲線において２００〜３００℃の範囲に観測される最大の吸熱ピークの面積から計算される熱量Ｈ（Ｊ／ｇ）より下記式により算出する。
結晶化度＝ΔＨ／２２５×１００ （％）
【００５１】
(3) 結晶配向度 (b)
株式会社リガク製イメージングプレートＸ線回折装置、ＲＩＮＴ（登録商標）２０００を用いて下記の条件で繊維の回折像を取り込む。
Ｘ線源 ： ＣｕＫ瘰
出力 ： ４０ＫＶ １５２ｍＡ
カメラ長 ： ９４．５ｍｍ
測定時間 ： ３分
得られた画像の２θ＝２１°付近に観察される（１１０）面を円周方向にスキャンして得られる強度分布の半値幅Ｈから下記式により算出する。
結晶配向度＝［（１８０−Ｈ）／１８０］×１００（％）
(4) 繊度、強力、強度
繊度は、試料を２５℃、５５％湿度下で４８時間静置後、試料１００ｍの質量Ｗ₁を計量し、Ｗ₁×１００を繊維の総繊度（ｄｔｅｘ）とする。
この試料を、試料長２５０ｍｍ、クロスヘッド速度３００ｍｍ／分にて引張り、強力および強度を測定する。
また、総繊度を繊維の作製に用いた紡糸口金のホール数で除した値を単糸繊度とする。
【００５２】
(5) 単糸膠着率(d)
(A) 単糸数
ポリケトン繊維をエポキシモノマー〔ケトール８１２（商品名、日新ＥＭ社製）〕と硬化剤（ドデシルサクソニックアンハイドライド、メチルナディックアンハイドライド）の混合溶液に浸漬した後、開始剤〔ＤＭＰ−３０（商品名、日新ＥＭ社製）〕を加え、６０℃の加熱条件下で２４時間処理して重合を行い、繊維を樹脂によって包埋する。
樹脂包埋した繊維をミクロトームで切断し、繊維断面を電子顕微鏡にて撮影する。撮影したネガ画像を画像解析装置（ＩＰ１０００−ＰＣ：商品名、旭化成社製）を用いて、以下の方法で計測する。
スキャナーを使用して、ネガ画像を白黒２５６階調で取り込む。取り込んだ２５６階調の画像に対し、２値化処理を行う。
この際に設定するパラメーターは、(1) しきい値（＝自動）、(2) シェーディング補正処理（＝有り）、(3) 穴埋め処理（＝有り）、(4) ガンマ補正処理（＝補正値γ＝２．２）、(5) 小図形面積（１μｍ以下除去）である。
得られた２値化画像より、粒子解析ソフトにより単糸数を計算する。
【００５３】
(B) 見かけの単糸数
黒色台紙上でポリケトン繊維をチョークで軽く２０回擦って繊維を解繊し、１００倍の拡大鏡にてフィラメント数を数える。
膠着して分繊出来ないものについては１本の単糸として数え、３回の測定の平均値を見かけの単糸数とする。
ポリケトン繊維の単糸数が多い場合は１度に解繊処理を行わず、解繊前に以下の式(9) に基づいてポリケトン繊維をｎ個に分割し、分割された単位ごとに解繊処理を行いフィラメント数を計測していき、その和を見かけの単糸数とする。
Ｎ／２００≧ｎ≧Ｎ／３００ ・・・(9)
〔ただし、Ｎ＝単糸数（Ａでの計測値）〕
計測した単糸数、見かけの単糸数から下式(10)により単糸膠着率を求める。
単糸膠着率＝［１−（見かけの単糸数／単糸数）］×１００（％）・・・(10)
【００５４】
(6) 仕上げ剤付着率(e)
繊維を５０℃のメチルエチルケトンにて洗浄し、洗浄前の質量Ｗ₂（ｇ）、洗浄後の質量をＷ₃（ｇ）とし、下式(11)により仕上げ剤付着率(e) を求める。
なお、繊維の質量（Ｗ₂およびＷ₃）は、計量前に１０５℃で５時間加熱し絶乾状態として測定する。
仕上げ剤付着率(e) ＝（Ｗ₂−Ｗ₃）／Ｗ₃×１００（％）・・・(11)
(7) 樹脂付着率
撚糸物１ｍを１０５℃で５時間加熱した後に絶乾質量Ｗ₄（ｇ）を計量する。次いで、ロープを１ｍｍ長に細断して、ヘキサフルオロイソプロパノールにて攪拌下で６０℃、２時間溶解する。溶解後ろ過し、得られた残さを１０５℃で５時間加熱処理した後に質量Ｗ₅（ｇ）を精秤し、下式(12)から樹脂付着率を求める。
樹脂付着率＝［Ｗ₅／（Ｗ₄−Ｗ₅）］×１００（％）・・・(12)
【００５５】
(8) 繊維−繊維間動摩擦係数(f)
約６９０ｍの繊維を円筒の周りに、綾角１５°で約１０ｇの張力を掛けて巻き付け、更に上述と同じ繊維３０．５ｃｍをこの円筒に掛けた。この時、この繊維は円筒の上にあり、円筒の巻き付け方向と平行にする。
グラム数で表した荷重の値が円筒上に掛けた繊維の総繊度の０．１倍になる重りを円筒に掛けた繊維の片方の端に結び、他方の端にはストレインゲージを連結させた。次に円筒を１８ｍ／分の周速で回転させ、張力をストレインゲージで測定する。
こうして測定した張力から繊維−繊維間静摩擦係数(f) を以下の式(13)に従って求めた。
μ＝１／π×ｌｎ（Ｔ₂／Ｔ₁）・・・(13)
（ここで、Ｔ₁は繊維に掛けた重りの重さ、Ｔ₂は測定した時の張力、ｌｎは自然対数、πは円周率を示す。）
【００５６】
(9) 真円率(g)
(5) −Ａで得られたポリケトン繊維断面写真画像を、異形度測定装置ＦＭＳ−２０００（商品名、ユニオンシステム社製）により単糸の最小外接円直径Ｒ₁および最大内接円直径Ｒ₂を求める。
断面写真内の任意の５０本の単糸についてＲ₁／Ｒ₂を求め、その平均値を真円率(g)とする。
【００５７】
(10) 撚糸強力利用率(h)
撚糸強力利用率（％）として、Ｆ／Ｆ₀ ×１００で表されるものである。
（ただし、Ｆは撚糸後の強力であり、Ｆ₀ は撚糸に用いた全ポリケトン繊維の強力の和である。）
なお、ＲＦＬ処理後の撚糸強力利用率＝ＲＦＬ処理撚糸物の強力／撚糸に用いるポリケトン繊維の強力の和に相当する。
【００５８】
（ポリケトン繊維）
【実施例１】
常法により調製したエチレンと一酸化炭素が完全交互共重合した極限粘度５．９のポリケトンを、塩化カルシウム４０質量％／塩化亜鉛２２質量％を含有する水溶液に添加し、８０℃で２時間攪拌後さらに９０℃で１時間溶解しポリマー濃度６．８質量％のドープを得た。
得られたドープを８０℃に加温し、２０μｍ径のフィルターでろ過した後に、紡口径０．１５ｍｍφ、Ｌ／Ｄ＝１、ホール数５０の丸紡口より１０ｍｍのエアーギャップを通した後に、２質量％の塩化カルシウム及び１．１質量％の塩化亜鉛、０．１質量％の塩酸を含有する−２℃の水からなる凝固浴に吐出量４．５ｃｃ／分の速度で押出し凝固糸条とした。さらに、ポリケトン凝固糸を温度３０℃、濃度２質量％の塩酸水溶液で洗浄し、さらに４０℃の水で仕上げ洗浄を行った後、速度５ｍ／分で巻取った。
得られた凝固糸を簡易脱水した後、ＩＲＧＡＮＯＸ（登録商標、チバスペシャリティケミカルス社製）１０９８、ＩＲＧＡＮＯＸ（登録商標、チバスペシャリティケミカルス社製）１０７６をそれぞれ０．０５質量％ずつ（対ポリケトン）含浸せしめ、引き続き温度２２５℃で１分間の定長乾燥した。
【００５９】
この繊維に０．０２ｃＮ／ｄｔｅｘの張力をかけた状態で、圧気処理装置（ＨｅｍａＪｅｔ（登録商標、日本ヘバライン社製）Ｔ−３４１）を用いて０．２ＭＰａの圧縮空気を吹き付けて解繊した。このときのポリケトン繊維の水分率は０．２％であった。
この繊維を、２２５℃の加熱炉で１段目（７倍）の延伸を行った後に、この延伸糸をさらに０．０５ｃＮ／ｄｔｅｘの張力をかけた状態で圧気処理装置〔ＨｅｍａＪｅｔ（登録商標、日本ヘバライン社製）Ｔ−３２１〕を用いて０．１ＭＰａの圧縮空気を吹き付けて解繊した。このときのポリケトン繊維の水分率は０％であった。
解繊後、引続き２４０℃の加熱炉で２段目（１．８倍）、さらに２５８℃の加熱炉で３段目（１．３５倍）の延伸を行った。
【００６０】
得られた延伸糸に仕上げ剤を付与し、０．５ｃＮ／ｄｔｅｘの張力をかけながら１８０℃で１０秒間の熱処理を行い、５０．１ｄｔｅｘ／５０ｆのポリケトン繊維を得た。
仕上げ剤は以下の組成のものを用いた。オレイン酸ラウリルエステル／ビスオキシエチルビスフェノールＡ／ポリエーテル（プロピレンオキシド／エチレンオキシド＝３５／６５：分子量２００００）／ポリエチレンオキシド１０モル付加オレイルエーテル／ポリエチレンオキシド１０モル付加ひまし油エーテル／ステアリルスルホン酸ナトリウム／ジオクチルリン酸ナトリウム＝３０／３０／１０／５／２３／１／１（質量％比）。
【００６１】
紡糸、乾燥、延伸の工程通過性は極めて良好で毛羽や断糸等のトラブルは全く発生しなかった。
このポリケトン繊維は、引張強力は９．２７Ｎ、強度１８．５ｃＮ／ｄｔｅｘと極めて優れた強度を有するものであった。また、この繊維の単糸膠着率(d) は０％、μは０．１１であり、繊維に０．０５ｃＮ／ｄｔｅｘの荷重をかけた状態で１５００回／ｍの撚りをかけたところ（撚り係数＝１０６１７）、撚糸強力利用率(h) は８６．５％と極めて優れた値を示した。
本発明の実施例のポリケトン繊維の構造および撚糸特性を下記の実施例２〜実施例１３および比較例１〜１１の結果と併せて表１にまとめて示す。
【００６２】
【実施例２】
実施例１で得られたポリケトン繊維に１０００回／ｍの撚りをかけたところ（撚り係数＝７０７８）、撚糸強力利用率(h) は９０．６％と極めて優れた値を示した。
【実施例３】
実施例１で得られたポリケトン繊維に２０００回／ｍの撚りをかけたところ（撚り係数＝１４１５６）、撚糸強力利用率(h) は７８．２％と優れた値を示した。
【実施例４】
実施例１において、乾燥途中の水分率２５％の繊維を張力０．０４ｃＮ／ｄｔｅｘの張力をかけてセラミックス製のガイドでしごいて解繊し、延伸途中の解繊を行わない以外は同様にして紡糸、乾燥、延伸、仕上げ剤付与を行った。
得られたポリケトン繊維の単糸膠着率(d) は６％と良好で、１５００回／ｍの撚りをかけたとき（撚り係数＝１０５３２）の撚糸強力利用率(h) は８１．８％と極めて優れた性能を示した。
【００６３】
【実施例５】
実施例１において乾燥工程入り口にてポリケトン繊維（水分率＝１２００％）に平均粒径５μｍのシリカ微粒子エマルジョンを付与し、乾燥工程および延伸工程にて圧気処理を行わない以外は同様にして、紡糸、洗浄、乾燥、延伸、仕上げ剤付与を行った。
得られたポリケトン繊維の単糸膠着率(d) は１０％と良好で、１５００回／ｍの撚りをかけたとき（撚り係数＝１０８３７）の撚糸強力利用率(h) は８１．２％と極めて優れた性能を示した。
【実施例６】
実施例１において、１段延伸後の解繊処理後に仕上げ剤を付与し、延伸終了後の仕上げ剤付与と併せて２段階付与とする以外は同様にしてポリケトン繊維を得た。
得られたポリケトン繊維の単糸膠着率(d) は４％と良好で、１５００回／ｍの撚りをかけたとき（撚り係数＝１０８１７）の撚糸強力利用率(h) は７４．７％と良好な性能を示した。
【００６４】
【実施例７】
実施例１において仕上げ剤の付与量を２．２％から５．２％（対ポリケトン繊維）と増やす以外は同様にしてポリケトン繊維を得た。
得られたポリケトン繊維のμは０．１１から０．０８へと小さくなり、１５００回／ｍの撚りをかけたとき（撚り係数＝１０７６５）の撚糸強力利用率(h) は８７．３％と極めて優れた性能を示した。
【実施例８】
実施例１において、仕上げ剤に以下の組成のものを用いる以外は同様にしてポリケトン繊維を得た。
オレイン酸ソルビタンエステル／ポリエチレンオキシド１０モル付加ヒマシ油エステル／ビスフェノールＡラウリル酸エステル／ポリエチレンオキシド硬化ヒマシ油マレイン酸エステル／ポリエーテル（プロピレンオキシド／エチレンオキシド＝３５／６５：分子量２００００）／ステアリルスルホン酸ナトリウム／ジオクチルリン酸ナトリウム＝３０／３０／２０／１３／５／１／１（質量比）。
得られたポリケトン繊維は、１５００回／ｍの撚りをかけたとき（撚り係数＝１０６３８）の撚糸強力利用率(h) は８３．９％と極めて優れた性能を示した。
【００６５】
【実施例９】
実施例１において、ポリケトンの溶剤を塩化亜鉛／塩化ナトリウム＝６５質量％／１０質量％を含有する水溶液とし、ポリケトンの濃度を８．２質量％とする以外は同様にして紡糸、洗浄、乾燥、解繊処理、延伸、仕上げ剤付与を行った。
得られたポリケトン繊維の単糸膠着率は１６％とまずまず良好で、１５００回／ｍの撚りをかけたとき（撚り係数＝１１１６５）の撚糸強力利用率(h) は７４．５％と良好な性能を示した。
【実施例１０】
実施例１において、紡口径を０．１８ｍｍφとし、吐出量を６．７５ｃｃ／分とする以外は同様にして紡糸、洗浄、乾燥、解繊処理、延伸、仕上げ剤付与を行った。
得られたポリケトン繊維の単糸膠着率は０％と良好で、１２００回／ｍの撚りをかけたとき（撚り係数＝１０４７５）の撚糸強力利用率(h) は７９．５％と良好な性能を示した。
【００６６】
【実施例１１】
実施例１において、紡口径を０．２５ｍｍφとし、吐出量を１１．２５ｃｃ／分とする以外は同様にして紡糸、洗浄、乾燥、解繊処理、延伸、仕上げ剤付与を行った。
得られたポリケトン繊維の単糸膠着率(d) は０％と良好で、１０００回／ｍの撚りをかけたとき（撚り係数＝１１２０３）の撚糸強力利用率(h) は７６．２％と良好な性能を示した。
【実施例１２】
実施例１において、紡口数を３００とし、吐出量を２７ｃｃ／分とし、乾燥条件を１６０℃で２０秒処理後２２５℃で１分間の定長乾燥とする以外は同様にして紡糸、洗浄、乾燥、解繊処理、延伸、仕上げ剤付与を行った。
得られたポリケトン繊維の単糸膠着率(d) は１％と良好で、６００回／ｍの撚りをかけたとき（撚り係数＝１０７７５）の撚糸強力利用率(h) は８３．２％と極めて良好な性能を示した。
【００６７】
【実施例１３】
実施例１２において１段延伸および解繊処理を行ったポリケトン繊維５本を合糸して３８９０ｄｔｅｘ／１５００ｆとし、引続き２段延伸、３段延伸、仕上げ剤付与を行う以外は同様にしてポリケトン繊維を作製した。
得られたポリケトン繊維の単糸膠着率(d) は１％と良好で、２５０回／ｍの撚りをかけたとき（撚り係数＝１００７８）の撚糸強力利用率(h) は８４．３％と極めて良好な性能を示した。
【００６８】
【比較例１】
実施例１において、解繊処理を一切行わず、延伸後の仕上げ剤付与も行わない以外は同様にして紡糸、洗浄、乾燥、延伸を行った。
得られたポリケトン繊維は単糸膠着率(d) が５５％と悪く、１４００回／ｍの撚りをかけたとき（撚り係数＝９９１９）の撚糸強力利用率(h) も５９．３％と低く、本発明の範囲外のものであった。
【比較例２】
実施例９において、解繊処理を一切行わず、延伸後の仕上げ剤付与も行わない以外は同様にして紡糸、洗浄、乾燥、延伸を行った。
得られたポリケトン繊維は単糸膠着率(d) が７２％と極めて悪く、１４００回／ｍの撚りをかけたとき（撚り係数＝９８８０）の撚糸強力利用率(h) も５３．２％と極めて低く、本発明の範囲外のものであった。
【００６９】
【比較例３】
実施例１において、乾燥工程入り口（ポリケトン繊維の水分率＝１１００％）で圧力０．２ＭＰａにて実施例１と同じ圧気処理をしたところ、断糸や毛羽、たるみが多発し延伸することが出来なかった。
【比較例４】
実施例１において、▲１▼洗浄工程終了後、温度１５０℃で３５秒間の乾燥を施したポリケトン繊維（水分率＝５９％）を圧力０．２ＭＰａにて実施例１と同じ圧気処理をして、▲２▼１段延伸後の圧気処理を行わない、▲３▼延伸後の仕上げ剤付与を行わない、以外は同様にしてポリケトン繊維を作製した。
得られたポリケトン繊維は単糸膠着率(d) が４４％と悪く、１４００回／ｍの撚りをかけたとき（撚り係数＝９９６９）の撚糸強力利用率(h) も６２．０％と不十分で、本発明の範囲外のものであった。
【００７０】
【比較例５】
実施例５において、シリカ微粒子エマルジョンの付与位置を乾燥工程出口（ポリケトン繊維の水分率＝０．２％）とする以外は同様にしてポリケトン繊維を作製した。
得られたポリケトン繊維は単糸膠着率(d) が５９％と悪く、１４００回／ｍの撚りをかけたとき（撚り係数＝１００４７）の撚糸強力利用率(h) も５４．５％と全く不十分で、本発明の範囲外のものであった。
【比較例６】
実施例５において、シリカ微粒子エマルジョンの付与位置を凝固浴出口（洗浄工程入り口前）とする以外は同様にして洗浄、乾燥後、延伸を行ったところ、延伸時に断糸して延伸することが出来なかった。
【００７１】
【比較例７】
比較例１において、延伸終了後に実施例１と同じ仕上げ剤を付与し、１８０℃で１０秒間の熱処理する以外は同様にしてポリケトン繊維を作製した。
得られたポリケトン繊維はμが０．１１と良好であったものの、単糸膠着率(d) が６５％と悪く、１４００回／ｍの撚りをかけたとき（撚り係数＝１０２１１）の撚糸強力利用率(h) も５８．３％と全く不十分で、本発明の範囲外のものであった。
【比較例８】
実施例１において、延伸終了後に仕上げ剤を付与しないでポリケトン繊維を巻き取った。得られたポリケトン繊維３０本を張力０．２ｃＮ／ｄｔｅｘで引き揃え合糸した。
このポリケトン繊維を２５０回／ｍの撚りをかけたとき（撚り係数＝９６１４）の撚糸強力利用率(h) は７４．８％と良好であったが、撚糸物には多数の毛羽が観察された。
このポリケトン繊維は仕上げ剤が付着していないため、μが高く、繊維を擦り合わせると容易に断糸が起こった。擦過部を電子顕微鏡で観察すると直径０．１〜１μｍのフィブリル状物が多数観察された。
【００７２】
【比較例９】
実施例１で用いたポリケトンを、７５質量％のレゾルシンを含む水溶液に添加し、８０℃、２時間攪拌、溶解し、ポリマー濃度８質量％のドープを得た。得られたドープを紡口径０．１５ｍｍφ、Ｌ／Ｄ＝１、ホール数５０の紡口より吐出量５．８ｃｃ／分の速度で吐出し、１０ｍｍのエアーギャップを経て、−５℃のメタノール浴中に押出して凝固糸を得た。
得られた凝固糸を２０℃のメタノール中で１．２倍に引張りながら洗浄後、１００℃にて定長乾燥し未延伸糸を得た。
この未延伸糸を加熱板上で２２５℃で５倍、引続き２４０℃で２．５倍、さらに２５８℃で１．３倍の延伸を行い延伸糸とした。この延伸糸２４本を合糸して巻き取った。
この繊維は単糸膠着率(d) １２％であり、２５０回／ｍの撚りをかけたとき（撚り係数＝１０２９３）の撚糸強力利用率(h) は６９．５％であった。
【００７３】
【比較例１０】
実施例１で用いたポリケトンをヘキサフルオロイソプロパノールに添加し、３０℃で２時間攪拌して溶解し、ポリマー濃度７重量％のドープを得た。得られたドープを紡口径０．１５ｍｍφのＬ／Ｄ＝１、ホール数５０の紡口より吐出量６．３ｃｃ／分の速度で１０℃のアセトン浴中に押出して凝固糸を得た。
得られた凝固糸を温度４０℃、風速１ｍ／分の窒素が流れる長さ１０ｍのチャンバー中を通し、４ｍ／分の速度で巻き取り凝固糸を得た。得られた凝固糸を３０℃、２４時間静置し乾燥し未延伸糸を得た。
この未延伸糸を加熱板上で２２５℃で５倍、引き続き２４０℃で２．５倍、さらに２５８℃で１．３倍の延伸を行い延伸糸とした。この延伸糸２４本を合糸し、実施例１と同じ仕上げ剤を付与して巻き取った。
この繊維は単糸膠着率(d) が３８％と本発明の範囲外であり、２５０回／ｍの撚りをかけたとき（撚り係数＝１０３３８）の撚糸強力利用率(h) は６４．２％と不十分であった。
【００７４】
【比較例１１】
比較例２で作製したポリケトン繊維に実施例１で用いた仕上げ剤を付与した繊維３０本を合糸し、再び実施例１で用いた仕上げ剤を付与した後に１８０℃、１０秒間の熱処理を行いポリケトン繊維とした。
この繊維は単糸膠着率(d) が７２％であり、２５０回／ｍの撚りをかけたとき（撚り係数＝９９０６）の撚糸強力利用率(h) は５８．１％と全く不十分で本発明の範囲外あった。
【００７５】
（ポリケトン撚糸物）
【実施例１４】
実施例１３で調製したポリケトン繊維をＺ方向に３９０回／ｍで下撚り（下撚り張力０．０５ｃＮ／ｄｔｅｘ）し、これを２本双糸しＳ方向に３９０回／ｍ上撚り（上撚り張力０．０５ｃＮ／ｄｔｅｘ）して撚糸物を得た。
このポリケトン撚糸物は撚り係数は２２２３３であり、撚糸強力利用率(h) は８０．１％と極めて高く、撚糸物強度も１４．２ｃＮ／ｄｔｅｘと極めて優れたものであった。
さらにポリケトン撚糸物を、下記の液組成のＲＦＬ液に浸漬した後に、乾燥ゾーン（張力３Ｎで１６０℃で１２０秒の熱処理）、ヒートセットゾーン（張力４．２Ｎで２２０℃で６０秒の熱処理）、ノルマライジングゾーン（張力２．８Ｎで２２０℃、６０秒の熱処理）を通してＲＦＬ処理ポリケトン撚糸物を得た。
【００７６】
（ＲＦＬ液組成）
レゾルシン ２２．０部
ホルマリン（３０質量％） ３０．０部
水酸化ナトリウム（１０質量％） １４．０部
水 ５７０．０部
ビニルピリジンラテックス（４１質量％） ３６４．０部
得られたＲＦＬ樹脂付着ポリケトン撚糸物は撚糸強力利用率(h) が７９．５％と極めて高く、撚糸物の強度も１４．１ｃＮ／ｄｔｅｘと極めて優れたものであった。
【００７７】
本発明の実施例において、撚糸条件、ＲＦＬ処理条件および撚糸物の性能を以下の実施例１５〜１７および比較例１２〜１７の結果と併せて表２にまとめて示す。
【実施例１５】
撚糸条件を下撚り数および上撚り数をそれぞれ２９０Ｔ／ｍとする以外は、実施例１４と同様の処方でポリケトン撚糸物を作製した。
得られたポリケトン撚糸物（撚り係数１６５３３）は撚糸強力利用率(h) が９０．５％と極めて高く、撚糸物の強度も１６．０ｃＮ／ｄｔｅｘと極めて優れたものであり、ＲＦＬ処理後のポリケトン撚糸物も極めて優れた撚糸強力利用率(h) および強度を有していた。
【実施例１６】
撚糸条件を下撚り数および上撚り数をそれぞれ１９０Ｔ／ｍとする以外は、実施例１４と同様の処方でポリケトン撚糸物を作製した。
得られたポリケトン撚糸物（撚り係数１０８３２）は撚糸強力利用率(d) が９７．１％と極めて高く、撚糸物の強度も１７．２ｃＮ／ｄｔｅｘと極めて優れたものであり、ＲＦＬ処理後のポリケトン撚糸物も極めて優れた撚糸強力利用率(h) および強度を有していた。
【００７８】
【実施例１７】
実施例１４において、下撚りしたポリケトン撚糸物３本を撚り合わせたものを上撚りする以外は同様にして撚糸を行った。
得られたポリケトン撚糸物（撚り係数２０２４８）は撚糸強力利用率(h) が８４．１％と極めて高く、撚糸物の強度も１４．９ｃＮ／ｄｔｅｘと極めて優れたものであり、ＲＦＬ処理後のポリケトン撚糸物も極めて優れた撚糸強力利用率(h) および強度を有していた。
【００７９】
【比較例１２】
比較例９で作製したポリケトン繊維を用い、実施例１４と同様の条件で上撚り／下撚り共に３９０回／ｍの撚糸を行った。
撚糸性は不良で撚糸時に多数の毛羽が発生した。また、得られたポリケトン撚糸物（撚り係数２２７１４）は撚糸強力利用率(h) が６０．５％と本発明のポリケトン撚糸物に比べて不十分なものであった。
また、ＲＦＬ液処理後の撚糸物の撚糸強力利用率(h) および撚糸物強度も本発明のポリケトン撚糸物と比べて不十分なものであった。
【比較例１３】
比較例１２において、撚糸回数を上撚り／下撚り共に２９０回／ｍとする以外は同様にして撚糸を行った。
撚糸性は不良で撚糸時に多数の毛羽が発生した。得られたポリケトン撚糸物（撚り係数１６８９０）は撚糸強力利用率(h) が７７．９％と本発明のポリケトン撚糸物に比べて不十分なものであった。また、ＲＦＬ液処理後の撚糸物の撚糸強力利用率(h) および撚糸物強度も本発明のポリケトン撚糸物と比べて不十分なものであった。
【００８０】
【比較例１４】
比較例１０で作製したポリケトン繊維を用い、実施例１４と同様の条件で上撚り／下撚り共に３９０回／ｍの撚糸を行った。
得られたポリケトン撚糸物（撚り係数２２８０７）は撚糸強力利用率(h) が６２．５％、撚糸物の強度は５．１ｃＮ／ｄｔｅｘと本発明のポリケトン撚糸物に比べて大きく劣るものであった。また、ＲＦＬ液処理後の撚糸物の撚糸強力利用率(h) および撚糸物強度も本発明のポリケトン撚糸物と比べて大きく劣るものであった。
【比較例１５】
比較例２で作製したポリケトン繊維３０本を合糸し、実施例１４と同様の条件で上撚り／下撚り共に３９０回／ｍの撚糸を行った。
撚糸物のたるみが多く、また、撚糸時に毛羽が多発して十分な品位の撚糸物を得ることが出来なかった。
【００８１】
【比較例１６】
比較例８で作製したポリケトン繊維を用い、実施例１４と同様の条件で上撚り／下撚り共に３９０回／ｍの撚糸を行った。
撚糸性は不良で撚糸時に多数の毛羽が発生した。得られたポリケトン撚糸物（撚り係数２１２１１）は撚糸強力利用率(h) が６４．９％と本発明のポリケトン撚糸物に比べて劣り、また多数の毛羽があり品位が悪く、単糸間で毛羽やフィブリルが絡まったものであった。
【比較例１７】
比較例１１で作製したポリケトン繊維を用い、実施例１４と同様の条件で上撚り／下撚り共に３９０回／ｍの撚糸を行った。
得られたポリケトン撚糸物（撚り係数２１８５４）は撚糸強力利用率(h) が６３．１％と本発明のポリケトン撚糸物に比べて大きく劣るものであった。原糸の強度は実施例１４と同等にも関わらず、撚糸物の強度は１０．６ｃＮ／ｄｔｅｘと全く劣るものであった。また、ＲＦＬ液処理後の撚糸物の撚糸強力利用率(h) および撚糸物強度も本発明のポリケトン撚糸物と比べて大きく劣るものであった。
【００８２】
【表１】

表１は、本発明のポリケトン繊維および比較例のポリケトン繊維の特性を示す表である。
【００８３】
【表２】

【００８４】
（注）＊；ＲＥＬ処理後の撚糸強力利用率(h) ＝ＲＥＬ処理撚糸物の強力／撚糸に用いるポリケトン繊維の強力の和
＊＊；式(3) ＝１００×（１−４．７９×１０^-9×Ｋ^1.78）
表２は、本発明のポリケトンポリケトン撚糸物および比較例のポリケトン撚糸物の特性を示す表である。
【００８５】
【発明の効果】
本発明のポリケトン繊維は高強度、高弾性率の優れた力学特性を有すると共に、単糸膠着がなく、繊維−繊維間の動摩擦係数が小さく均質で欠陥の少ない繊維であり、優れた撚糸強力利用率を有し、撚糸後にも高い強度を発現し、さらには耐疲労性にも優れる繊維である。
本発明のポリケトン繊維を撚糸物とすることで高強度産業資材として幅広い分野（例えば、網、ネットやロープ、ケーブル等の土木・工業用資材、タイヤ・ベルト・ホース等のゴム補強材、プラスチック強化繊維等の補強材料等）へ展開することが期待される。
特に、高い力学的負荷を受け、補強材である撚糸物に高強度が要求される用途、例えばタイヤやベルト、ホースのゴム補強材料やＦＲＰ等の補強材料として極めて有用である。[0001]
BACKGROUND OF THE INVENTION
  The present invention is a polyketone fiber having excellent mechanical properties such as high strength and high elastic modulus, high melting point, and excellent heat properties such as high heat resistance, fatigue resistance, twist resistance, and strong utilization after twisting. Polyketone fiber with excellent processability during drawing, twisting, and post-processing,Polyketone twisted product and molded article thereofAbout.
  The polyketone fiber of the present invention can be processed into twisted yarns and applied to a wide range of uses such as household materials, daily life materials, and industrial materials, and in particular, industrial materials for which high strength is required as twisted yarns, specifically tires. It is extremely useful as a fiber material for rubber reinforcement such as belts, hoses, and ropes.
[0002]
[Prior art]
In recent years, it is known that a polyketone in which carbon monoxide and an olefin are completely copolymerized can be obtained by polymerizing carbon monoxide and an olefin such as ethylene or propylene using palladium or nickel as a catalyst.
Polyketone fibers have high strength, high elastic modulus, high heat resistance, adhesiveness, and creep resistance, and are expected to be used in industrial materials such as rubber reinforcing fibers for tire cords and belts, and fibers for concrete reinforcement. ing.
In particular, polyketones mainly composed of ethylene and carbon monoxide repeating units (1-oxotrimethylene) have high crystallinity and melting point, high strength and high elastic modulus, low physical property change and shrinkage at high temperature, etc. The thermal stability is also the best. About this polyketone fiber, many fiberization is examined until now.
[0003]
Specifically, in JP-A-2-112413, JP-A-4-228613, JP-A-4-505344, JP-A-7-508317, etc., hexafluoroisopropanol, m-cresol, Polyketone fibers that have been wet-spun using an organic solvent such as chlorophenol, resorcin / water, phenol / acetone, propylene carbonate / hydroquinone, pyrrole, resorcin / propylene carbonate, pyridine, and formic acid are known.
However, in these documents, although there are disclosures of techniques for polyketone fibers with high strength, high elastic modulus, and high melting point, there are problems of polyketone fibers with low single-fiber sticking problems of polyketone fibers and less friction between fibers. There is no disclosure.
Only JP 7-508317 A discloses a high-strength polyketone fiber in which single yarn sticking is suppressed by pre-drawing at room temperature after coagulation using a resorcin / water solvent and a methanol coagulation bath. However, in the present invention, only a high-strength polyketone multifilament with less single yarn sticking is shown, and there is no description regarding reduction of the frictional resistance of the fiber.
[0004]
Although such a polyketone fiber certainly has high strength and high elastic modulus, since there is no single yarn sticking, the converging property of the fiber is lowered, and the fiber-fiber friction and the fiber-metal friction resistance increase. The problem is that the single yarn breaks due to frictional resistance during drawing or twisting, the fiber surface is rubbed and a fibrillar product is formed and entangled between the single yarns, and the quality of the twisted yarn deteriorates. Problems such as reduced fatigue resistance occur.
Also, in WO99 / 18143, WO00 / 09611, and JP2001-115007, etc., polyketone fibers having high strength and high elastic modulus are wet-spun using a metal salt solution such as zinc salt, calcium salt, and iron salt. The technology is known.
[0005]
However, when multifilament wet spinning was performed using a metal salt solution as a solvent, it became clear that severe single yarn sticking occurred during drying. Such single yarn agglomeration remains up to the fiber after hot drawing and the final fiber product after processing, which causes not only the process stability and quality degradation of fluff and yarn breakage, but also the twisted yarn when twisted. There is a problem that the strength of the steel is greatly reduced. In the known invention related to wet spinning using a metal salt solution, the problem of single yarn sticking and the solution thereof are not described at all. There is no description of any technology relating to improvement of process passability during drawing or twisting due to reduction of friction between them and improvement of physical properties of the twisted yarn after twisting.
As described above, the polyketone fiber has no problem of single yarn sticking, has low friction between fibers and fibers, has excellent twisting process passability, and has excellent quality and mechanical properties, resistance after twisting. There is no known polyketone fiber that can exhibit fatigue properties.
[0006]
On the other hand, some literatures are known also about the twisted thing which consists of polyketone fiber.
In JP-A-9-329198, there is a description of a twisted product comprising a polyketone fiber obtained by a melt spinning method and a polyketone fiber obtained by a wet spinning method using hexafluoroisopropanol as a solvent. -There is no description about the friction between fibers, and it does not give any knowledge about the present invention.
Japanese Patent Application Laid-Open No. 1-124617 discloses that polyketone fibers are twisted together. The present invention uses a polyketone fiber having low mechanical properties and low heat resistance obtained by melt spinning a low-melting polyketone. In addition, there is no description at all about techniques relating to single yarn sticking of polyketone fibers and friction of fibers.
In JP-A-11-334313 and JP-A-11-336957, a twisted yarn comprising a polyketone fiber obtained by a melt spinning method and a polyketone fiber (ECO fiber) composed only of 1-oxotrimethylene. Although there are descriptions of products, there is no suggestion in these inventions regarding techniques for suppressing single yarn sticking, reducing friction between fibers and fibers, and increasing the twisting strength utilization rate of polyketone fibers.
As described above, a polyketone twisted yarn comprising a polyketone fiber having no single yarn sticking and low fiber-fiber friction, and having excellent twisting process passability, twisting strength utilization, and fatigue resistance. The technology about things is not known at all until now.
[0007]
[Problems to be solved by the present invention]
  As a problem to be solved by the present invention, one problem is that it has excellent mechanical properties such as high strength and high elastic modulus, and there is no single yarn sticking and the friction between fiber and fiber and between fiber and metal is small. Polyketone fiber with passability of twisted yarn process, strong utilization of twisted yarn, and fatigue resistanceTheThe second challenge is to provide a high-strength polyketone twisted product with high twist-strength utilization and excellent fatigue resistance.And moldings therefromIs to provide.
[0008]
[Means for Solving the Problems]
  As a result of intensive studies on the structure and production method of polyketone fibers in order to achieve the above-mentioned problems, the present inventors have achieved a reduction in single yarn agglomeration, a reduction in the coefficient of friction between fibers and fibers, and a cross-sectional shape of the fibers together with a high strength technology As a result of finding out that the homogenization and the optimization of the single yarn fineness are the countermeasures, the present invention has been achieved.
  That is, the present invention is basically:
  95 to 100% by mass of the repeating unit is composed of 1-oxotrimethylene represented by the following structural formula (1)Finishing agent adhered to the surfaceA polyketone fiber, which satisfies the following requirements a to e.
  (A): Crystallinity ≧ 60%
  (B): Crystal orientation degree ≧ 90%
  (C): Tensile strength ≧ 10 cN / dtex
  (D): Single yarn sticking rate ≦ 30%
  (E): Finishing agent adhesion rate = 0.3-15% by mass
  (f); Fiber-fiber dynamic friction coefficient = 0.01 to 0.5
[Chemical 3]

[0009]
The polyketone fiber of the present invention is a polyketone in which 95 to 100% by mass of repeating units are composed of 1-oxotrimethylene.
The higher the proportion of 1-oxotrimethylene in the repeating unit, the higher the regularity of the molecular chain, and a fiber with high crystallinity and high degree of orientation can be obtained. As a result, high strength, high elastic modulus and high heat resistance are obtained. Fiber is obtained.
For this reason, the proportion of 1-oxotrimethylene is preferably 97 to 100% by mass, and most preferably 100% by mass.
Moreover, you may copolymerize the compound which has unsaturated hydrocarbons, such as olefins other than ethylene, such as propene and hexene, methyl methacrylate, and sodium allylsulfonate, as needed.
[0010]
The degree of polymerization of the polyketone is preferably 2 to 10 in terms of intrinsic viscosity.
When the intrinsic viscosity is less than 2, the strength and spinnability of the polyketone fiber are lowered. Further, when the intrinsic viscosity exceeds 10, the polymerization cost and the spinning cost become high, and it becomes difficult to obtain a polyketone fiber at a practical price.
For this reason, as a polymerization degree of polyketone, it is desirable that intrinsic viscosity is in the range of 2 to 10, more preferably in the range of 3 to 6.
[0011]
The polyketone fiber of the present invention is required to have a crystallinity and a crystal orientation within a specific range in order to exhibit characteristics of high strength, high elastic modulus, and high heat resistance.
The degree of crystallinity (a) is a structural parameter representing the quantitative ratio of the crystal structure. If this value is less than 60%, the polyketone fiber cannot exhibit sufficient strength, elastic modulus and heat resistance. The higher the crystallinity (a), the higher the strength, the higher dimensional stability, the higher heat resistance, and the higher the chemical resistance. Therefore, the crystallinity (a) needs to be 60% or more, more preferably 70% or more, and particularly preferably. It is desirable that it is 80% or more.
The degree of crystal orientation (b) is a structural parameter representing the degree of regularity in which the molecular chains in the fiber are aligned in the fiber axis direction. If this value is less than 90%, the molecular chain is not sufficiently aligned and the elastic modulus Is low and the dimensional stability with respect to the load is insufficient.
The higher the degree of crystal orientation (b), the higher the modulus of elasticity and the more excellent the dimensional stability, so 90% or more is required, more preferably 95% or more, and particularly preferably 97% or more. Is desirable.
Moreover, the polyketone fiber of the present invention is a fiber excellent in tensile strength. As the tensile strength (c) is higher, a high-strength twisted product can be obtained, and fluff and breakage due to tension during stretching and twisting are less likely to occur.
Therefore, the tensile strength (c) needs to be 10 cN / dtex or more, more preferably 13 cN / dtex or more, further preferably 15 cN / dtex or more, and particularly preferably 17 cN / dtex or more. .
[0012]
Since high-strength polyketone fibers are highly oriented in the fiber axis direction, when twisted, (1) the problem is that strength decreases due to forces in directions other than the fiber axis direction; (2) fiber surface Due to the rubbing of each other, single yarns are cut or fibrils are generated, so that problems such as entanglement between single yarns and deterioration of process passability and quality often occur.
The most important technical problem of the present invention is to provide a fiber that does not cause the problems (1) and (2) even if it is a highly crystallized and oriented high-strength polyketone fiber. To solve these problems, (i) no single yarn sticking, (ii) low fiber-to-fiber friction, (iii) low single yarn fineness, (iv) fuzz and fibrils It was important that there was no form, and in particular, polyketone fibers satisfying (i) and (ii) at the same time were found to exhibit extremely excellent characteristics against the decrease in strength and processability due to twisted yarn.
[0013]
Regarding the single yarn agglutination of the polyketone fiber of the present invention, the single yarn agglutination rate (d) defined by the following formula (4) is 30% or less.
Single yarn sticking rate (d) = [1− (apparent number of single yarn / number of single yarn)] × 100 (%) (4)
(Here, the single yarn sticking rate (d) is a value representing the numerical ratio of the single yarn stuck in the multifilament.)
As a specific example, if there are two pairs of fibers produced using a spinneret having 10 holes and two single yarns are stuck together, the number of single yarns is 10 Thus, the apparent number of single yarns is 8, and the single yarn sticking rate (d) is 20%.
When the single yarn agglutination rate (d) is greater than 30%, the fiber becomes hard, and an excessive force is easily applied to the single yarn, causing fluff and breakage during twisting, resulting in reduced strength after twisting. The problem becomes obvious.
The single yarn sticking rate (d) is more preferably 20% or less, particularly preferably 10% or less, and most preferably 0%.
[0014]
It is also important that the fiber-to-fiber friction is small. To achieve this, 0.1 to 20% by mass of a finishing agent is added to the polyketone fiber, and wasteful contact due to fiber bundling and antistatic operation. It is extremely effective to reduce resistance and reduce the coefficient of friction on the fiber surface by forming an oil film.
There is no restriction | limiting in particular about the component of a finishing agent, For example, the finishing agent of Japanese Patent Application No. 2000-19995 can be used.
Specifically, as a constituent component of the finishing agent, at least one selected from (1) ester compounds, (2) mineral oils, and (3) polyethers is an essential component, and the total amount is 30 in the finishing agent. Finishing agents containing -100% by weight, preferably 50-80% by weight are preferred.
By applying such a finishing agent, a strong oil film is formed on the surface of the polyketone fiber, and the fiber surface is slid by the oil film, so that the fiber is not worn in a short time during drawing or twisting.
[0015]
The ester compound (1) is a component that improves the smoothness and abrasion resistance of the polyketone fiber surface, and specific examples include octyl stearate, lauryl oleate, etc., the molecular weight of which is smooth, process passability From the viewpoint, 500 to 3000 is preferable.
Mineral oil (2) is also a component that improves the smoothness and abrasion resistance of the polyketone fiber surface, and is preferably paraffinic or naphthenic, and its viscosity is such that the viscosity of Redwood at 30 ° C. is 40 to 800 seconds. preferable.
Polyether (3) has the function of increasing the strength of the oil film formed on the fiber surface by the finish. Specifically, polyether (3) is a polyether mainly composed of polyolefin oxide formed by copolymerization of propylene oxide and ethylene oxide. The molecular weight is preferably 1500 to 20000 from the viewpoint of wear resistance.
[0016]
Moreover, it is preferable that the finishing agent used by this invention contains an emulsifier (for example, polyoxyethylene stearyl ether etc.), an antistatic agent (anionic surfactant etc.), and antioxidant.
If the adhesion rate (e) of the finishing agent is less than 0.3% by mass, the effect of reducing the frictional resistance is insufficient, and if it exceeds 15% by mass, the contact resistance between the oil films increases, and vice versa. Since the friction between the fibers increases, the adhesion rate (e) of the finishing agent is preferably 0.3 to 15% by mass, more preferably 0.5 to 10% by mass, and still more preferably the polyketone fiber. 1 to 5% by mass.
The finish can be applied straight as it is, or dispersed in water and attached to the fiber as an emulsion finish.
In particular, for polyketone fibers with a large number of single yarns, it is important to uniformly infiltrate the oil agent between the fibers. When an activator having an ester group, a ketone group, or an ether group is used as a penetrant, the finish is evenly distributed between the polyketone fibers. It is effective that it can be dispersed and applied.
[0017]
Further, as a means for reducing the resistance between the fibers, it is effective to make the cross section of the fibers difficult to be rubbed.
The cross-sectional shape of the polyketone fiber of the present invention is not particularly limited, and can be selected according to the purpose such as circle, ellipse, triangle, square, rhombus, alphabet, star shape, hollow, etc., but extremely high twist strength utilization rate, In order to obtain process passability, a circular shape (round section or ellipse) is desirable, and a round section having a roundness ratio (g) of 1.0 to 1.2 is more preferable.
Here, the roundness (g) is a value obtained from the minimum circumscribed circle radius / maximum inscribed circle radius of the polyketone fiber cross section, and the closer to 1.0, the closer to the perfect circle.
The closer the roundness (g) is to 1.0, the smaller the contact area between single yarns and the lower the fiber-fiber friction resistance, and the higher the fatigue resistance and twist strength utilization rate of the twisted yarn. The process passage through time is improved.
The roundness (g) is more preferably 1.0 to 1.1.
[0018]
The polyketone fiber of the present invention preferably has a fiber-to-fiber dynamic friction coefficient (f) (hereinafter sometimes abbreviated as μ) of 0.01 to 0.5 by applying a finishing agent and designing the fiber cross-sectional shape. .
When μ exceeds 0.5, a load is applied at the time of twisting, fluff and yarn breakage occur frequently, and the twisted yarn strength utilization rate is greatly reduced. On the other hand, when μ is less than 0.01, the converging property of the multifilament is lowered, sagging occurs, the twisted yarn strength utilization rate (h) and the quality are lowered, and the workability and handleability are deteriorated.
For this reason, the value of μ is preferably 0.03 to 0.4, more preferably 0.05 to 0.3.
[0019]
Furthermore, it is of course important that the polyketone fiber of the present invention has few fuzz and fibrils.
Here, the fluff is a fiber in which one end produced by cutting a single yarn is not constrained.
The fibrillar material is a cylindrical material made of polyketone having a diameter of 0.01 to several μm and a length of 1 μm to several tens of mm, which is peeled off by impact or wear.
These fluffs and fibrils not only reduce the strength of the polyketone fiber, but also entangle with adjacent single yarns or two or more adjacent single yarns to form knots, thereby reducing the twist strength utilization rate (h).
The number of fluff is preferably 1/10 m or less, more preferably 1/100 m or less, and still more preferably 1/10000 m or less.
Further, the number of fibrils is preferably 1 or less in 100 visual fields when the fiber bundle is observed with an optical microscope, and preferably 0 in 100 visual fields.
[0020]
The single yarn fineness of the polyketone fiber is not particularly limited, but is preferably 0.1 to 10 dtex from the viewpoint of the twisted yarn utilization factor and process passability.
When the single yarn fineness is less than 0.1 dtex, fluff and yarn breakage occur during spinning and twisting, and the product quality and process passability are lowered. In addition, when the single yarn fineness exceeds 10 dtex, there is a problem that the twist strength utilization rate at the time of strong twisting is lowered.
Therefore, the single yarn fineness is more preferably 0.5 to 5 dtex, and particularly preferably 0.8 to 2 dtex.
The total fineness of the polyketone fiber is not particularly limited because it varies depending on the application and use site, but is usually 10 to 10000 dtex, preferably 300 to 3000 dtex.
[0021]
The polyketone fiber of the present invention is a fiber that has high strength but does not have single yarn sticking, has a finishing agent, has a small dynamic friction coefficient (f) μ, and is excellent in twisting properties. The twist strength utilization rate (h) when twisted so that the twist coefficient K is 10,000 is preferably 65% or more.
In the present invention, the twisted yarn strength utilization rate (h) is 100 fractions obtained by dividing the strength of the polyketone twisted product after twisting by the strength of the polyketone fiber before twisting.
For example, in the case where a plurality of polyketone fibers are twisted together, the twisted yarn strength utilization rate (h) is defined as 100 minutes obtained by dividing the strength of the twisted polyketone fiber by the sum of the strength of the twisted polyketone fibers.
K is a twist coefficient of the twisted product defined by the following formula (1).
K = Y × D^0.5  (T / m · dtex^0.5(1)
[However, in the formula (1), Y is the number of twists per 1 m of the polyketone twisted product (T / m), and D is the total fineness (dtex) of the polyketone twisted product. ]
[0022]
Here, the total displayed fineness is the sum of the finenesses of all polyketone fibers used in the twisted yarn.
For example, when three 1670 dtex polyketone fibers are twisted together, the total displayed fineness of the twisted product is 5010 dtex (1670/3). When a plurality of polyketone fibers are twisted together and a multi-stage twist such as a lower twist or an upper twist is added, the number of twists added last is used as the twist number Y to calculate the twist coefficient.
When used for rubber reinforcing materials such as tire cords, belts and hoses, or ropes, nets, fishing nets, etc., twisted yarns having a twist coefficient K in the range of 10,000 to 30,000 are often used.
In the polyketone fiber, the twist strength utilization rate (h) decreases as the twist coefficient K increases, and when the twist strength utilization rate (h) of the polyketone fiber at K is 10,000 is less than 65%, K is 10,000 to 30000. The twisting strength utilization rate (h) is further smaller than 65%.
For this reason, the strength of the twisted yarn does not have a practical strength even if a high-strength polyketone fiber is used in most applications, and troubles such as fluff and yarn breakage occur frequently during the twisting process. Decrease occurs.
For this reason, the twist strength utilization rate (h) when the twist coefficient K is 10,000 is preferably 65% or more, more preferably 75%, and further preferably 80% or more.
[0023]
The twist strength utilization rate (h) of the polyketone fiber varies greatly depending on the twisting conditions (fineness of the polyketone fiber used, the number of twisted yarns, etc.). The smaller the polyketone fiber fineness and the smaller the number of twisted yarns, the greater the twist strength utilization rate. (h) becomes higher.
For this reason, it is preferable that the polyketone fiber of this invention exists in the range of the following Formula (2) with respect to the twist coefficient K.
Twisted yarn strength utilization rate (h) (%) ≧ 100−K / 300 (2)
[0024]
Polyketone fibers are expected to be used in applications that receive high loads such as rubber reinforcing materials such as tires, belts and hoses. In these applications, usually two or three or more twisted fibers are twisted together and further twisted in the opposite direction to the twisted twist to obtain a twisted product, and the resulting twisted product requires high strength. .
The inventors of the present invention are extremely superior to conventional polyketone fibers by performing the above-mentioned single yarn agglutination rate, finishing composition / application method, fiber cross-sectional shape, fibril suppression, and single yarn fineness under optimum conditions. A polyketone fiber having a high twist yarn utilization rate (h) was found.
This polyketone fiber having a high twist yarn strength utilization rate has a twist yarn strength utilization rate (h) in the range of the following formula (3), and is extremely useful for high load applications such as rubber reinforcing materials and ropes.
Twisted yarn strength utilization rate (%) ≧ 100 × (1-4.79 × 10^-9× K^1.78) ... (3)
Specifically, the value of the twisted yarn strength utilization rate (h) represented by the above formula (3) is 98% or more when the twist coefficient K is 5000, 94% or more when the twist coefficient K is 10,000, and the twist coefficient K is It is 87% or more at 15000, 78% or more when the twist coefficient K is 20000, 68% or more when the twist coefficient K is 25000, and maintains a high twisting yarn utilization rate (h) from sweet twist to strong twist. is there.
[0025]
Moreover, you may use the polyketone fiber of this invention as a short fiber.
The polyketone short fiber is obtained by cutting the polyketone filament described above in the yarn length direction.
The length of the short fiber is not particularly limited and may be cut to an arbitrary length depending on the use environment and the purpose of use. Usually, the average length of the short fiber is 0.1 to 100 mm, preferably 0.5. Those having a length of ˜50 mm are preferably used.
In the present invention, the average length L of the short fibers is the length of one short fiber in the longitudinal direction (fiber axis direction)._iAs an average length of 100 short fibers selected arbitrarily, it is calculated by the following formula (5).
Such a short fiber is useful for applications such as a knitted fabric and a rope as a reinforcing material such as concrete or as a spun yarn.
[Expression 1]

[0026]
Another embodiment of the present invention is a polyketone twisted product obtained by twisting the above-described polyketone fiber having high strength and high elastic modulus and excellent twisting properties.
In the present invention, the twisted yarn means a fiber material in which fibers are twisted at a rate of 10 times / m or more, and if it is less than 100% by mass with respect to the fiber material, resin, adhesive, oil, etc. Substances other than the fiber material may be contained.
The twisted product of the present invention contains the polyketone fiber of the present invention in at least a part of the fiber material constituting the twisted product.
[0027]
The higher the proportion of the polyketone fiber in the twisted yarn, the higher the strength, the higher mechanical properties, and the higher heat resistance. Therefore, preferably 50 to 100 mass% of the twisted yarn, more preferably 80 to 100 mass% of the twisted yarn. The polyketone fiber of the present invention is desirable.
Among them, a polyketone twisted product in which 100% by mass of the fiber material is composed of the polyketone fiber of the present invention is useful as a high-strength fiber material.
In particular, a polyketone twisted product having a twist strength utilization rate (h) in the range of the following formula (3) exhibits extremely high mechanical properties in a wide range of twisted yarns, and has a high strength not obtained by conventional polyketone twisted products. It is.
Twisted yarn strength utilization rate (h) (%) ≧ 100 × (1-4.79 × 10^-9× K^1.78) ... (3)
[0028]
The strength (strength) of the polyketone twisted product of the present invention varies depending on the twisting conditions, application, use site, etc., and is difficult to define unconditionally. However, when the twist coefficient K is 10,000, it is preferably 10 cN / dtex or more, more preferably 13 cN / dtex or more, particularly preferably 15 cN / dtex or more, and when the twist coefficient K is 20000, preferably 8 cN / dtex or more, more preferably 10 cN / dtex or more, and particularly preferably 12 cN / dtex or more. .
Here, the strength of the twisted product is a value obtained by dividing the strength of the twisted product by the total displayed fineness of the fibers used in the twisted yarn.
[0029]
Moreover, you may contain fibers other than polyketone fiber as needed (for example, polyester fiber, aramid fiber, cellulose fiber, polyamide fiber, polyvinyl alcohol fiber, etc.).
There are no particular restrictions on the twisted form of the polyketone twisted product, and examples of the type of twisted yarn include single twisted yarn, cocoon twisted yarn, picco cocoon twisted yarn, strong twisted yarn, etc. It may be a twist, a triple twist, or a multiple twist of four or more.
The thickness of the twisted yarn is appropriately selected according to the use, and those having a diameter of 0.1 to 10 mm are suitably used for rubber reinforcement materials, and those having a diameter of 1 to 100 mm are suitable for ropes and nets.
The number of twisted yarns can be appropriately selected according to the use, part, etc., but the above-mentioned twist coefficient K is preferably in the range of 100 to 50000, more preferably in the range of 1000 to 30000.
[0030]
Moreover, when using the polyketone twisted material of this invention as a rubber reinforcement material, an adhesive agent may be made to adhere for the purpose of improving adhesiveness with rubber | gum.
There is no restriction | limiting in particular in the kind of adhesive agent, You may use a conventionally well-known thing as it is, or changing conditions according to the objective.
As the adhesive, resorcin-formalin-latex (RFL) resin is suitably used, and the adhesion rate of the RFL resin is preferably 0.1 to 10% by mass, more preferably 1 to 7% by mass with respect to the fiber. .
[0031]
The molded product containing the polyketone fiber and the polyketone twisted product of the present invention has high mechanical properties, has few single yarn sticking and fuzz, and has excellent fatigue resistance due to a low coefficient of friction between fibers. It becomes.
In the present invention, the molded body refers to not only textile products such as ropes, woven fabrics, knitted fabrics, nets and nets, but also rubber products such as tires, belts, hoses, endless track bodies, and artificial products such as resin products such as FRP. means.
[0032]
Next, the manufacturing method of the polyketone fiber and polyketone twisted material of this invention is demonstrated.
The method for producing the polyketone fiber of the present invention is not particularly limited, but a wet spinning method using a metal salt solution as a solvent is preferable from the viewpoints of handleability, toxicity, flammability, polyketone modification, cost, and the like.
Hereinafter, a method for producing the polyketone fiber of the present invention by a wet spinning method using a metal salt solution as a solvent will be described.
The metal salt solution used for dissolving the polyketone is not particularly limited as long as it has the ability to dissolve the polyketone, and examples thereof include zinc halide, alkali metal halide, alkaline earth metal halide and the like.
The metal salt solution is preferably an aqueous solution from the viewpoint of explosiveness, handleability, and cost, and an aqueous solution containing 10 to 80% by mass of zinc halide (such as zinc chloride or zinc iodide) is particularly preferably used. Moreover, you may mix compounds other than said metal salt in the range which does not inhibit the objective of this invention.
[0033]
The salt concentration of the metal salt solution is preferably 50 to 80% by mass.
When the salt concentration is lower than 50% by mass or when the salt concentration is higher than 80% by mass, the spinning becomes unstable.
The salt concentration is a value defined by the following formula (6).
Salt concentration (mass%) = [mass of salt / (mass of salt + mass of solvent)] × 100 (6)
The polymer concentration of the polyketone dissolved in the metal salt solution is preferably 0.1 to 40% by mass, more preferably 3 to 20% by mass from the viewpoints of solubility, spinnability, and production cost.
The polymer concentration is a value defined by the following formula (7).
Polymer concentration (mass%) = [polymer mass / (polymer mass + mass of metal salt solution)] × 100 (7)
[0034]
The obtained polyketone solution is filtered through a filter as necessary, and then extruded from a spinneret into a coagulation bath to form a fiber. When the difference between the temperature of the polyketone solution at the time of extrusion and the temperature of the coagulation bath is large, a method in which the fibrous material from the spinneret enters the bath through the air phase, the so-called air gap method is preferred.
There is no particular limitation on the composition and temperature of the coagulation bath, but an aqueous salt solution used in the solvent is preferable from the viewpoint of reducing the recovery cost of the solvent.
The fibrous material pulled out of the coagulation bath is washed with water, and the metal salt is substantially removed using an aqueous solution containing hydrochloric acid, sulfuric acid, phosphoric acid or the like and having a pH of 4 or less as necessary.
In particular, the metal salt solution is an aqueous solution of calcium chloride / zinc chloride (mass ratio of 68/32 to 61/39) having a salt concentration of 59 to 64% by mass, and the temperature of the polyketone solution when extruded from the spinneret. Is 60 to 150 ° C. and the temperature of the coagulation bath is −50 to 20 ° C. In addition to increasing the effect of decreasing the single yarn sticking rate (d), it is also preferable because of increasing the strength.
[0035]
Next, drying is performed to remove water contained in the fibers.
There is no particular limitation on the drying method, and drying can be performed using a known facility such as a tunnel dryer, a roll heater, or a net process dryer, while stretching, under a constant length, or shrinking.
Although there is no restriction | limiting in particular in drying temperature, Preferably it is 100 to 260 degreeC, More preferably, it is 120 to 250 degreeC, Most preferably, it is 150 to 240 degreeC.
Subsequently, this dried yarn is continuously stretched by one or two or more stages.
[0036]
Stretching may be performed in any number of stages, and when performing multistage stretching, a method of gradually increasing the stretching temperature is preferable. The stretching temperature is preferably 150 ° C. to the melting point of the polyketone fiber.
When the temperature is lower than 150 ° C., it is difficult to obtain a polyketone fiber having high strength and high elastic modulus, and when the temperature is higher than the melting point of the polyketone fiber, the yarn melts and cuts during stretching.
From the viewpoint of stretchability and fiber physical properties, the melting point of the polyketone fiber is preferably 150 ° C., more preferably 200 ° C. to the melting point of the polyketone fiber −5 ° C.
Further, from the viewpoint of the mechanical properties of the resulting polyketone fiber, the total draw ratio is preferably 10 times or more, more preferably 15 times or more.
As the heat drawing apparatus, a method of traveling on a heating roll or a heating plate or in a heated gas, or a conventionally known apparatus such as irradiating a traveling yarn with laser, microwave, infrared, or the like may be used as it is or after being modified. it can.
[0037]
In the wet spinning method using a metal salt, single yarn sticking is likely to occur in the drying step. Therefore, it is extremely important to take measures to prevent single yarn sticking.
As a method of preventing single yarn sticking, there is a method of applying an external force to the fiber to shift the single yarn, a method of applying a release agent to the fiber surface before the sticking occurs, and an electrostatic repulsion force between the single yarns. In particular, a method of applying an external force to the fiber to shift between single yarns and a method of applying a release agent to the fiber surface are preferably used from the viewpoint of physical properties of the resulting fiber and process passability.
[0038]
When applying an external force that causes a shift between single yarns, the external force can be applied once or a plurality of times at any stage up to the end of the drying step and / or the drawing step. It is important to treat the fibers that are.
In the present invention, the moisture content is defined by the following formula (8).
Moisture content (mass%) = [(residual fiber mass−absolute fiber mass) / residual fiber mass] × 100 (8)
Here, the absolutely dry fiber mass is a fiber mass when the moisture is completely removed by drying at 105 ° C. for 5 hours.
If the moisture content of the fiber is higher than 40% by mass, problems such as deformation of the single yarn, damage to the fiber, and sagging are likely to occur when an external force that causes deviation between single yarns is applied. The moisture content is more preferably 30% by mass or less.
On the other hand, when the moisture content is as low as 0 to 1% by mass, static electricity is likely to be generated due to the friction between the fibers and between the fibers and the manufacturing apparatus. It is desirable to take measures to eliminate static electricity, such as applying a certain oil.
[0039]
Misalignment between single yarns means that the relative positional relationship between adjacent single yarns changes (the side surfaces between adjacent single yarns are separated, and the side surfaces between adjacent single yarns slip along the side surfaces). Thus, the sticking between the single yarns can be prevented, or the once generated sticking can be removed, and a polyketone fiber having a low single yarn sticking rate can be obtained.
As the external force that causes the deviation between the single yarns, it is effective to squeeze the fibers or give vibrations to the fibers.
Specifically, a method of squeezing the fiber through a pin guide or a roll, a method of vibrating the fiber with an ultrasonic generator, a method of blowing a compressed gas onto the fiber, and the like can be mentioned.
A fiber with a high roundness (g) is obtained that is difficult to cause deformation and scratches on the single yarn cross section, and a compressed gas is blown onto the fiber in that it is easy to obtain a fiber with good operability and low single yarn sticking rate. The method is preferably used.
The composition of the compressed gas is not particularly limited, but air and nitrogen are preferable from the viewpoints of safety and handleability, and air is most preferable.
[0040]
In order to obtain a polyketone fiber having a low single yarn sticking rate (d) without damaging the fiber, it is important to set the tension applied to the fiber and the speed at which the compressed gas is blown within an appropriate range.
Specifically, the tension applied to the fiber is set in the range of 0 to 1 cN / dtex, and the spraying speed is set in the range of 0.1 to 100 m / second, preferably 10 to 50 m / second.
When the single yarn sticking rate (d) is high, it is effective to reduce the tension applied to the fiber and to increase the gas blowing speed.
There are no particular restrictions on the apparatus, method, and shape of the spray hole for blowing compressed gas, and any shape (round, oval, rectangular, etc.) may be used at the tip of a conventionally known pressure treatment device such as an interlacer or false twist nozzle, or pressure pipe. , Rectangular, etc.) holes may be attached.
[0041]
When a release agent is applied to the fiber surface before single yarn sticking occurs, there is no particular limitation as long as the release agent has an action of preventing sticking by subsequent drying and heat drawing.
In the present invention, the release agent is arranged so that the two polyketone fibers are bonded over the fiber axis direction after applying the release agent compound to two parallel polyketone fiber surfaces, When a constant-length heat treatment is performed at 225 ° C. for 1 minute, a compound having an action of easily defibrating polyketone fibers is used as a release agent.
Examples of such release agents include, for example, water-insoluble particulate matter (metal oxide fine particles, metal fine particles, silicon-based compound fine particles, fluorine-based compound fine particles), water-insoluble organic matter (mineral oil, high molecular weight) Ester compounds, high molecular weight ether compounds) and dispersions thereof, etc., and from the viewpoint of uniform dispersion between polyketone fibers and handling properties, a fine particle dispersion mainly composed of metal oxide fine particles and silicon-based fine particles is preferably used. It is done.
The average particle size of the fine particle dispersion is preferably 0.1 to 100 μm, more preferably 0.2 to 10 μm. The dispersion medium of the fine particle dispersion is preferably water from the viewpoints of handleability and safety.
[0042]
Moreover, it is suitable that the adhesion amount of a mold release agent shall be 0.1-20 mass% with respect to a polyketone fiber.
When the amount of the release agent attached is less than 0.1% by mass, a sufficient single yarn anti-sticking effect cannot be obtained, and when it exceeds 20% by mass, the physical properties of the resulting polyketone fiber are deteriorated and stretchability is also achieved. It also has an adverse effect.
For this reason, it is desirable that the adhesion amount of the release agent is preferably 0.3 to 10% by mass, more preferably 0.5 to 5% by mass.
When applying a release agent, an important point is to apply the release agent at a stage where the moisture content of the polyketone fiber exceeds 40% at any stage from the washing step to the end of the drying step.
[0043]
When the moisture content is 40% or less, single yarn sticking starts to occur, and even if a release agent is applied, a sufficient single yarn sticking prevention effect cannot be obtained. For this reason, it is necessary to give the release agent at a stage where the moisture content of the polyketone fiber exceeds 40%, more preferably at a stage where the moisture percentage is 60% or more, more preferably 100% or more. It is desirable.
In addition, when the release agent is applied before completion of coagulation, the release agent enters the inside of the single yarn, and the fiber physical properties are extremely decreased. Therefore, it is desirable to perform the treatment after the acid washing step, and more preferably after the washing step. More preferably, it is desirable to apply after completion of the water washing step.
The release agent may be applied in a single stage or in multiple stages, and other components may be mixed with the release agent as long as the single yarn does not stick.
[0044]
In addition to the single yarn anti-sticking means, it is necessary to apply a finishing agent at any stage from the end of the drying step to the end of hot drawing to reduce μ. The finishing agent may be applied once or a plurality of times, or may be applied before or during the heat stretching process. The composition of the finishing agent is not particularly limited, and it can be applied straight, diluted with a solvent, or supplied as an emulsion or suspension. When applying a finishing agent as an aqueous solution, aqueous emulsion, or aqueous suspension after hot drawing, μ may increase due to moisture remaining between the fibers, and the twist strength utilization rate (h) may decrease. It is desirable to provide a step of drying the moisture after application.
The finishing agent applying device is not particularly limited, and a conventionally known device such as nozzle oil supply or roll oil supply can be used as it is or after being modified according to the purpose.
[0045]
In addition, in order to suppress the generation of fluff and fibrils during the drawing process, the equipment that contacts the fibers during the drawing process (excluding the speed regulating roll) should be made of a material with a low coefficient of friction with the polyketone fiber. Specifically, a material having a coefficient of dynamic friction between the fiber and metal of 0.1 or less, preferably 0.01 to 0.08 (for example, a metal oxide or metal having a large surface roughness) is preferable. In addition, it is desirable that these materials be conductive and gradually reduce static electricity generated by friction.
[0046]
The polyketone fiber after completion of the heat drawing step is continuously twisted as it is, or once wound up, twisting is performed.
The number of twisted yarns is selected according to the application and use environment. Generally, the twisted yarn K is twisted in the range of 1000 to 30000.
From the viewpoints of mechanical properties and quality of the twisted yarn, the twisting yarn tension is preferably 0.01 to 0.2 cN / dtex for both the lower twisting tension and the upper twisting tension.
[0047]
In the case of a rubber reinforcing fiber, the twisted polyketone twisted product is subsequently passed through a step (so-called Dip treatment step) in which an RFL solution having a concentration of 10 to 30% by mass is adhered and the resin is fixed.
The preferred composition of the RFL solution is 0.1 to 10% by weight of resorcin, 0.1 to 10% by weight of formalin and 1 to 28% by weight of latex, and more preferably 0.5 to 3% by weight of resorcin. %, Formalin 0.5-3 mass%, latex 10-25 mass% is desirable.
The drying temperature of the RFL solution is preferably 100 to 250 ° C., more preferably 140 to 200 ° C., and it is desirable to perform a drying heat treatment for at least 10 seconds, preferably 20 to 120 seconds.
[0048]
The twisted yarn after drying is subsequently subjected to heat treatment in the heat setting zone and the normalizing zone.
The temperature, tension, and time in the heat set zone are preferably 150 to 250 ° C., 0.1 to 0.7 cN / dtex, and 10 to 300 seconds, respectively. The temperature, tension, and time in the normalizing zone are preferably 150 to 250 ° C., 0.01 to 0.3 cN / dtex, and 10 to 300 seconds, respectively.
[0049]
The polyketone fiber obtained by the above method has excellent mechanical properties such as high strength and high elastic modulus, and high twisted yarn strength utilization rate, and maintains the strength of the raw yarn at a high level when it is a twisted product, It is useful as a high-strength fiber material excellent in fatigue resistance. In particular, the present invention is extremely useful in the field of industrial materials in which rubber reinforcing materials such as tire cords, hoses, and belts, and fibers such as ropes, nets, and fishing nets are twisted.
[0050]
【Example】
The present invention will be described in more detail with reference to the following examples, but they are not intended to limit the scope of the present invention.
The measurement method of each measurement value used in the description of the examples is as follows.
(1) Intrinsic viscosity
The intrinsic viscosity [η] is a value determined based on the following definition formula.
[Η] = lim (T−t) / (t · C) [dl / g]
C → 0
(T and T in the definition formula are the flow-through time of a viscosity tube at 25 ° C. of a diluted solution of hexafluoroisopropanol having a purity of 98% or more and a polyketone dissolved in the hexafluoroisopropanol. Solute mass value in grams in the middle.)
(2) Crystallinity (a)
Measurement is performed under the following conditions using a differential heat measuring device Pyris1 (trademark; manufactured by Perkin Elmer). The sample uses short fibers cut to a length of 5 mm.
Sample mass: 1mg
Measurement temperature: 30 ° C → 300 ° C
Temperature increase rate: 20 ° C / min
Atmosphere: Nitrogen, flow rate = 200 mL / min
The calorific value H (J / g) calculated from the area of the maximum endothermic peak observed in the range of 200 to 300 ° C. in the obtained endothermic curve is calculated by the following formula.
Crystallinity = ΔH / 225 × 100 (%)
[0051]
(3) Degree of crystal orientation (b)
Using a Rigaku Imaging Plate X-ray diffractometer, RINT (registered trademark) 2000, a fiber diffraction image is captured under the following conditions.
X-ray source: CuK
Output: 40KV 152mA
Camera length: 94.5mm
Measurement time: 3 minutes
The obtained image is calculated from the half width H of the intensity distribution obtained by scanning the (110) plane observed in the vicinity of 2θ = 21 ° in the circumferential direction by the following equation.
Crystal orientation = [(180−H) / 180] × 100 (%)
(4) Fineness, strength, strength
The fineness was determined by leaving the sample at 25 ° C. and 55% humidity for 48 hours,₁Weigh and W₁X100 is defined as the total fineness (dtex) of the fiber.
The sample is pulled at a sample length of 250 mm and a crosshead speed of 300 mm / min, and the strength and strength are measured.
Further, the value obtained by dividing the total fineness by the number of holes of the spinneret used for producing the fiber is defined as the single yarn fineness.
[0052]
(5) Single yarn sticking rate (d)
(A) Number of single yarn
After immersing the polyketone fiber in a mixed solution of an epoxy monomer [ketol 812 (trade name, manufactured by Nissin EM)] and a curing agent (dodecyl saxonic anhydride, methyl nadic anhydride), an initiator [DMP-30 ( (Trade name, manufactured by Nissin EM Co., Ltd.)] is added, polymerized by treatment for 24 hours under heating at 60 ° C., and the fibers are embedded with resin.
The resin-embedded fiber is cut with a microtome, and the fiber cross section is photographed with an electron microscope. The photographed negative image is measured by the following method using an image analysis apparatus (IP1000-PC: trade name, manufactured by Asahi Kasei Corporation).
Use a scanner to capture a negative image in 256 gray levels. A binarization process is performed on the captured 256-gradation image.
The parameters to be set at this time are (1) threshold value (= automatic), (2) shading correction processing (= present), (3) hole filling processing (= present), (4) gamma correction processing (= correction value) (γ = 2.2), (5) Small figure area (removed by 1 μm or less).
From the obtained binarized image, the number of single yarns is calculated by particle analysis software.
[0053]
(B) Apparent number of single yarns
The polyketone fiber is lightly rubbed with chalk 20 times on a black mount to defibrate the fiber, and the number of filaments is counted with a 100 times magnifier.
Those that cannot be separated due to agglutination are counted as one single yarn, and the average value of three measurements is the apparent number of single yarns.
If the number of single yarns of the polyketone fiber is large, the defibration treatment is not performed once, and the polyketone fiber is divided into n pieces based on the following formula (9) before defibration, and defibration treatment is performed for each divided unit And measure the number of filaments, and make the sum the apparent number of single yarns.
N / 200 ≧ n ≧ N / 300 (9)
[However, N = number of single yarns (measured value at A)]
From the measured number of single yarns and the apparent number of single yarns, the single yarn sticking rate is obtained by the following equation (10).
Single yarn sticking rate = [1− (apparent single yarn number / single yarn number)] × 100 (%) (10)
[0054]
(6) Finishing agent adhesion rate (e)
The fiber is washed with methyl ethyl ketone at 50 ° C., and the mass W before washing₂(G) The mass after washing is W_Three(G), and determine the finish adhesion rate (e) by the following formula (11).
The mass of the fiber (W₂And W_Three) Is measured at 105 ° C. for 5 hours before weighing and measured as an absolutely dry state.
Finishing agent adhesion rate (e) = (W₂-W_Three) / W_Three× 100 （％） ・ ・ ・ (11)
(7) Resin adhesion rate
Absolutely dry mass W after heating 1m of twisted material at 105 ° C for 5 hours_FourWeigh (g). Next, the rope is chopped into 1 mm lengths and dissolved in hexafluoroisopropanol at 60 ° C. for 2 hours with stirring. After dissolution, the mixture was filtered, and the resulting residue was heat-treated at 105 ° C. for 5 hours._Five(G) is precisely weighed, and the resin adhesion rate is obtained from the following equation (12).
Resin adhesion rate = [W_Five/ (W_Four-W_Five]] X 100 (%) (12)
[0055]
(8) Fiber-to-fiber dynamic friction coefficient (f)
A fiber of about 690 m was wound around the cylinder with a tension of about 10 g at a twill angle of 15 °, and 30.5 cm of the same fiber as above was hung on this cylinder. At this time, this fiber is on the cylinder and is parallel to the winding direction of the cylinder.
A weight with a load value expressed in grams of 0.1 times the total fineness of the fiber applied on the cylinder was tied to one end of the fiber applied to the cylinder, and a strain gauge was connected to the other end. . Next, the cylinder is rotated at a peripheral speed of 18 m / min, and the tension is measured with a strain gauge.
From the tension thus measured, the fiber-fiber static friction coefficient (f) was determined according to the following equation (13).
μ = 1 / π × ln (T₂/ T₁)···(13)
(Where T₁Is the weight of the weight on the fiber, T₂Is the measured tension, ln is the natural logarithm, and π is the circumference. )
[0056]
(9) Roundness (g)
(5) The minimum circumscribed circle diameter R of the single yarn is obtained by using the profile measuring device FMS-2000 (trade name, manufactured by Union System) of the polyketone fiber cross-sectional image obtained in -A.₁And the maximum inscribed circle diameter R₂Ask for.
R for any 50 single yarns in the cross-sectional picture₁/ R₂And the average value is defined as the roundness (g).
[0057]
(10) Twisted yarn strength utilization rate (h)
F / F as twisted yarn strength utilization rate (%)₀It is represented by x100.
(However, F is the strength after twisting and F₀Is the sum of the strength of all polyketone fibers used in the twisted yarn. )
In addition, it corresponds to the sum of the strength of the twisted yarn strength after the RFL treatment = the strength of the RFL-treated twisted yarn / the strength of the polyketone fiber used for the twisted yarn.
[0058]
(Polyketone fiber)
[Example 1]
A polyketone having an intrinsic viscosity of 5.9, which was prepared by a conventional method and was completely copolymerized with ethylene and carbon monoxide, was added to an aqueous solution containing 40% by weight of calcium chloride / 22% by weight of zinc chloride and stirred at 80 ° C. for 2 hours. Thereafter, it was further melted at 90 ° C. for 1 hour to obtain a dope having a polymer concentration of 6.8% by mass.
The obtained dope was heated to 80 ° C. and filtered through a 20 μm diameter filter, and after passing through an air gap of 10 mm from a round nozzle with a nozzle diameter of 0.15 mmφ, L / D = 1, and 50 holes, The coagulated yarn is extruded at a rate of 4.5 cc / min into a coagulation bath comprising -2 ° C water containing 2% by mass calcium chloride, 1.1% by mass zinc chloride and 0.1% by mass hydrochloric acid. It was. Further, the polyketone coagulated yarn was washed with a hydrochloric acid aqueous solution having a temperature of 30 ° C. and a concentration of 2% by mass, further subjected to finish washing with water at 40 ° C., and then wound up at a speed of 5 m / min.
The obtained coagulated yarn was simply dehydrated and impregnated with 0.05% by mass (with respect to polyketone) of IRGANOX (registered trademark, manufactured by Ciba Specialty Chemicals) 1098 and IRGANOX (registered trademark, manufactured by Ciba Specialty Chemicals) 1076 each. Subsequently, constant length drying was performed at a temperature of 225 ° C. for 1 minute.
[0059]
In a state where a tension of 0.02 cN / dtex was applied to the fibers, 0.2 MPa compressed air was blown using a pressure treatment apparatus (HemaJet (registered trademark, manufactured by Nippon Hebaline) T-341) for defibration. At this time, the water content of the polyketone fiber was 0.2%.
The fiber was first-stage (7 times) drawn in a heating furnace at 225 ° C., and then the drawn yarn was further subjected to a pressure treatment apparatus [HemaJet (registered trademark), under a tension of 0.05 cN / dtex. Using T-321] (manufactured by Nippon Hebaline Co., Ltd.), 0.1 MPa compressed air was blown to defibrate. At this time, the water content of the polyketone fiber was 0%.
After defibration, the second stage (1.8 times) was continued in a heating furnace at 240 ° C., and the third stage (1.35 times) was further stretched in a heating furnace at 258 ° C.
[0060]
A finish was added to the obtained drawn yarn, and heat treatment was performed at 180 ° C. for 10 seconds while applying a tension of 0.5 cN / dtex to obtain a polyketone fiber of 50.1 dtex / 50 f.
A finishing agent having the following composition was used. Oleic acid lauryl ester / bisoxyethyl bisphenol A / polyether (propylene oxide / ethylene oxide = 35/65: molecular weight 20000) / polyethylene oxide 10 mol addition oleyl ether / polyethylene oxide 10 mol addition castor oil ether / sodium stearylsulfonate / dioctyllin Sodium acid = 30/30/10/5/23/1/1 (mass% ratio).
[0061]
The processability of spinning, drying and drawing was very good, and troubles such as fluff and yarn breakage did not occur at all.
This polyketone fiber had an extremely excellent tensile strength of 9.27 N and a strength of 18.5 cN / dtex. Further, the single fiber sticking rate (d) of this fiber was 0% and μ was 0.11, and when the fiber was subjected to a twist of 1500 times / m with a load of 0.05 cN / dtex (twisted The coefficient = 10617) and the twisted yarn strength utilization rate (h) were 86.5%, showing an extremely excellent value.
The structure and twist characteristics of the polyketone fibers of the examples of the present invention are shown in Table 1 together with the results of Examples 2 to 13 and Comparative Examples 1 to 11 below.
[0062]
[Example 2]
When the polyketone fiber obtained in Example 1 was twisted 1000 times / m (twisting coefficient = 7078), the twist strength utilization rate (h) was 90.6%, showing an extremely excellent value.
[Example 3]
When the polyketone fiber obtained in Example 1 was twisted 2000 times / m (twisting coefficient = 14156), the twisted yarn strength utilization rate (h) showed an excellent value of 78.2%.
[Example 4]
In Example 1, a fiber having a moisture content of 25% during drying was defibrated by applying a tension of 0.04 cN / dtex with a ceramic guide and not defibrated during stretching. Spinning, drying, drawing, and applying a finishing agent were performed.
The obtained polyketone fiber has a good single yarn sticking rate (d) of 6%, and a twisted yarn strength utilization rate (h) of 81.8% when a twist of 1500 times / m is applied (twisting coefficient = 10532). It showed extremely good performance.
[0063]
[Example 5]
Spinning was carried out in the same manner as in Example 1, except that a silica fine particle emulsion having an average particle size of 5 μm was applied to the polyketone fiber (moisture content = 1200%) at the entrance of the drying process, and no pressure treatment was performed in the drying process and the stretching process. Washing, drying, stretching, and applying a finishing agent were performed.
The obtained polyketone fiber has a single yarn sticking rate (d) as good as 10%, and when a twist of 1500 times / m is applied (twisting factor = 10837), the twisted yarn strength utilization rate (h) is 81.2%. It showed extremely good performance.
[Example 6]
In Example 1, a polyketone fiber was obtained in the same manner except that a finishing agent was applied after the defibrating treatment after one-stage stretching, and two-stage application was performed in combination with finishing application after the completion of stretching.
The single yarn sticking rate (d) of the obtained polyketone fiber is as good as 4%, and when the twist of 1500 times / m is applied (twisting factor = 10817), the twisted yarn strength utilization rate (h) is 74.7%. It showed good performance.
[0064]
[Example 7]
Polyketone fibers were obtained in the same manner as in Example 1 except that the amount of finish applied was increased from 2.2% to 5.2% (vs. polyketone fibers).
The μ of the obtained polyketone fiber was reduced from 0.11 to 0.08, and the twisted yarn strength utilization rate (h) when twisting 1500 times / m (twisting coefficient = 10765) was 87.3%. It showed extremely good performance.
[Example 8]
In Example 1, polyketone fiber was obtained in the same manner except that the finishing agent having the following composition was used.
Oleic acid sorbitan ester / polyethylene oxide 10 mol addition castor oil ester / bisphenol A lauric acid ester / polyethylene oxide hydrogenated castor oil maleate ester / polyether (propylene oxide / ethylene oxide = 35/65: molecular weight 20000) / sodium stearyl sulfonate / Sodium dioctyl phosphate = 30/30/20/13/5/1/1 (mass ratio).
The obtained polyketone fiber exhibited a very excellent performance of 83.9% when the twisted yarn strength utilization rate (h) was applied at 1500 times / m (twisting coefficient = 10638).
[0065]
[Example 9]
In Example 1, the solvent of polyketone was an aqueous solution containing zinc chloride / sodium chloride = 65% by mass / 10% by mass, and the spinning, washing, drying were similarly performed except that the polyketone concentration was 8.2% by mass. Defibration treatment, stretching, and finishing agent application were performed.
The single yarn sticking rate of the obtained polyketone fiber is as good as 16%, and when the twist of 1500 times / m is applied (twisting coefficient = 11165), the twisted yarn strength utilization rate (h) is as good as 74.5%. Showed performance.
[Example 10]
In Example 1, spinning, washing, drying, defibrating treatment, stretching, and applying a finishing agent were performed in the same manner except that the nozzle diameter was 0.18 mmφ and the discharge rate was 6.75 cc / min.
The single yarn sticking rate of the obtained polyketone fiber is as good as 0%, and when the twist of 1200 times / m is applied (twisting coefficient = 10475), the twisted yarn strength utilization rate (h) is as good as 79.5%. showed that.
[0066]
Example 11
In Example 1, spinning, washing, drying, defibrating treatment, stretching, and applying a finishing agent were performed in the same manner except that the nozzle diameter was 0.25 mmφ and the discharge rate was 11.25 cc / min.
The single yarn sticking rate (d) of the obtained polyketone fiber is as good as 0%, and when the twist of 1000 times / m is applied (twisting factor = 11203), the twisted yarn strength utilization rate (h) is 76.2%. It showed good performance.
Example 12
In Example 1, spinning, washing and drying were carried out in the same manner except that the number of spinnerets was 300, the discharge rate was 27 cc / min, the drying conditions were 160 ° C. for 20 seconds, and then constant length drying at 225 ° C. for 1 minute. , Fibrillation treatment, stretching, and finishing agent application.
The obtained polyketone fiber has a single yarn sticking rate (d) as good as 1%, and a twisted yarn strength utilization rate (h) of 83.2% when twisting at 600 times / m (twisting factor = 10775) is applied. It showed very good performance.
[0067]
Example 13
The five polyketone fibers subjected to the one-stage stretching and defibrating treatment in Example 12 were combined to obtain 3890 dtex / 1500f, and the polyketone fibers were similarly prepared except that the second-stage stretching, the third-stage stretching, and the finishing agent were applied. Produced.
The obtained polyketone fiber has a single yarn sticking rate (d) as good as 1%, and when twisted at 250 times / m (twisting factor = 10078), the twisted yarn strength utilization rate (h) is 84.3%. It showed very good performance.
[0068]
[Comparative Example 1]
In Example 1, spinning, washing, drying and stretching were performed in the same manner except that no defibrating treatment was performed and no finishing agent was applied after stretching.
The resulting polyketone fiber has a single yarn sticking rate (d) as low as 55%, and the twisted yarn strength utilization rate (h) when twisted at 1400 times / m (twisting coefficient = 9919) is also as low as 59.3%. It was outside the scope of the present invention.
[Comparative Example 2]
In Example 9, spinning, washing, drying and stretching were performed in the same manner except that no defibrating treatment was performed and no finishing agent was applied after stretching.
The obtained polyketone fiber has a very low single yarn sticking rate (d) of 72%, and the twisted yarn strength utilization rate (h) when twisted 1400 times / m (twisting coefficient = 9880) is also 53.2%. It was very low and outside the scope of the present invention.
[0069]
[Comparative Example 3]
In Example 1, when the same air pressure treatment as in Example 1 was performed at the pressure of 0.2 MPa at the entrance of the drying process (moisture content of polyketone fiber = 1100%), thread breakage, fluff and sagging frequently occurred and the film could be stretched. There wasn't.
[Comparative Example 4]
In Example 1, after completion of (1) the cleaning step, the polyketone fiber (moisture content = 59%) that had been dried for 35 seconds at a temperature of 150 ° C. was subjected to the same pressure treatment as in Example 1 at a pressure of 0.2 MPa. (2) A polyketone fiber was prepared in the same manner except that the pressure treatment after one-stage stretching was not performed, and (3) the finishing agent was not applied after stretching.
The obtained polyketone fiber has a single yarn sticking rate (d) as poor as 44%, and a twisted yarn strength utilization rate (h) of 62.0% when twisted at 1400 times / m (twisting coefficient = 9969) is not good. It was sufficient and outside the scope of the present invention.
[0070]
[Comparative Example 5]
In Example 5, a polyketone fiber was produced in the same manner except that the application position of the silica fine particle emulsion was set to the drying process exit (moisture content of polyketone fiber = 0.2%).
The resulting polyketone fiber has a single yarn sticking rate (d) as poor as 59%, and when the twist of 1400 times / m is applied (twisting coefficient = 10047), the twisted yarn strength utilization rate (h) is also completely 54.5%. It was insufficient and outside the scope of the present invention.
[Comparative Example 6]
In Example 5, except that the application position of the silica fine particle emulsion was set to the coagulation bath outlet (before the cleaning process inlet), the same was washed, dried, and then stretched. There wasn't.
[0071]
[Comparative Example 7]
In Comparative Example 1, a polyketone fiber was prepared in the same manner except that the same finishing agent as in Example 1 was applied after the drawing was completed, and heat treatment was performed at 180 ° C. for 10 seconds.
Although the obtained polyketone fiber was good with a μ of 0.11, the single yarn sticking rate (d) was poor at 65%, and the twist strength when twisting 1400 times / m was applied (twist coefficient = 10211). The utilization rate (h) was 58.3%, which was completely insufficient and was outside the scope of the present invention.
[Comparative Example 8]
In Example 1, the polyketone fiber was wound up without applying a finishing agent after completion of stretching. Thirty polyketone fibers obtained were drawn and combined with a tension of 0.2 cN / dtex.
When this polyketone fiber was twisted 250 times / m (twisting coefficient = 9614), the twist strength utilization rate (h) was as good as 74.8%, but a lot of fluff was observed in the twisted product. It was.
Since this polyketone fiber does not have a finish attached, μ is high, and yarn breakage easily occurs when the fibers are rubbed together. When the rubbing part was observed with an electron microscope, many fibrils having a diameter of 0.1 to 1 μm were observed.
[0072]
[Comparative Example 9]
The polyketone used in Example 1 was added to an aqueous solution containing 75% by mass of resorcin, and stirred and dissolved at 80 ° C. for 2 hours to obtain a dope having a polymer concentration of 8% by mass. The obtained dope was discharged at a discharge rate of 5.8 cc / min from a nozzle with a nozzle diameter of 0.15 mmφ, L / D = 1, and 50 holes, passed through a 10 mm air gap, and a methanol bath at −5 ° C. It was extruded into a coagulated yarn.
The obtained coagulated yarn was washed while being pulled 1.2 times in methanol at 20 ° C. and then dried at a constant length at 100 ° C. to obtain an undrawn yarn.
This undrawn yarn was drawn on a heating plate 5 times at 225 ° C., 2.5 times at 240 ° C., and 1.3 times at 258 ° C. to obtain a drawn yarn. 24 of these drawn yarns were combined and wound up.
This fiber had a single yarn sticking rate (d) of 12% and a twist strength utilization rate (h) of 69.5% when twisted at 250 times / m (twisting coefficient = 10293).
[0073]
[Comparative Example 10]
The polyketone used in Example 1 was added to hexafluoroisopropanol and dissolved by stirring at 30 ° C. for 2 hours to obtain a dope having a polymer concentration of 7% by weight. The obtained dope was extruded into a 10 ° C. acetone bath at a rate of 6.3 cc / min from a nozzle with L / D = 1 with a nozzle diameter of 0.15 mmφ and a hole number of 50 to obtain a coagulated yarn.
The obtained coagulated yarn was passed through a 10 m long chamber through which nitrogen flowed at a temperature of 40 ° C. and a wind speed of 1 m / min to obtain a coagulated yarn wound up at a speed of 4 m / min. The obtained coagulated yarn was allowed to stand at 30 ° C. for 24 hours and dried to obtain an undrawn yarn.
This undrawn yarn was drawn on a heating plate 5 times at 225 ° C., then 2.5 times at 240 ° C., and further 1.3 times at 258 ° C. to obtain a drawn yarn. Twenty-four drawn yarns were combined, and the same finishing agent as in Example 1 was applied and wound up.
This fiber has a single yarn sticking rate (d) of 38%, which is outside the scope of the present invention, and a twist strength utilization rate (h) of 64.2 when twisting 250 times / m (twisting coefficient = 10338) is applied. % Was insufficient.
[0074]
[Comparative Example 11]
Thirty fibers with the finishing agent used in Example 1 were combined with the polyketone fiber produced in Comparative Example 2, and the finishing agent used in Example 1 was applied again, followed by heat treatment at 180 ° C. for 10 seconds. Polyketone fiber was used.
This fiber has a single yarn sticking rate (d) of 72%, and a twisting strength utilization rate (h) of 58.1% when twisted at 250 times / m (twisting coefficient = 9906) is quite insufficient. It was outside the scope of the present invention.
[0075]
(Polyketone twisted yarn)
Example 14
The polyketone fiber prepared in Example 13 was twisted at 390 turns / m in the Z direction (bottom twisting tension 0.05 cN / dtex), two of these were twisted and twisted at 390 turns / m in the S direction (top twist). (Tension 0.05 cN / dtex) to obtain a twisted product.
This polyketone twisted product had a twist coefficient of 22233, a twisted yarn strength utilization rate (h) as extremely high as 80.1%, and a twisted product strength of 14.2 cN / dtex was extremely excellent.
Further, after immersing the polyketone twisted product in an RFL solution having the following liquid composition, a drying zone (heat treatment at 160 ° C. for 120 seconds at a tension of 3 N) and a heat set zone (heat treatment at 220 ° C. for 60 seconds at a tension of 4.2 N) Then, an RFL-treated polyketone twisted product was obtained through a normalizing zone (heat treatment at 220 ° C. for 60 seconds at a tension of 2.8 N).
[0076]
(RFL solution composition)
Resorcin 22.0 parts
Formalin (30% by mass) 30.0 parts
Sodium hydroxide (10% by mass) 14.0 parts
570.0 parts of water
Vinylpyridine latex (41% by mass) 364.0 parts
The obtained RFL resin-attached polyketone twisted product had an extremely high twist strength utilization rate (h) of 79.5%, and the strength of the twisted product was extremely excellent at 14.1 cN / dtex.
[0077]
In the examples of the present invention, the twisting conditions, the RFL treatment conditions, and the performance of the twisted products are shown in Table 2 together with the results of the following Examples 15 to 17 and Comparative Examples 12 to 17.
Example 15
A polyketone twisted product was prepared in the same manner as in Example 14 except that the twisting condition was that the number of lower twists and the number of upper twists were 290 T / m, respectively.
The obtained polyketone twisted product (twist coefficient 16533) has a very high twist strength utilization rate (h) of 90.5%, and the twisted product has an extremely excellent strength of 16.0 cN / dtex. The polyketone twisted product also had extremely excellent twist strength utilization rate (h) and strength.
Example 16
A polyketone twisted product was prepared in the same manner as in Example 14 except that the twisting condition was that the number of lower twists and the number of upper twists were 190 T / m, respectively.
The obtained polyketone twisted product (twisting coefficient 10832) has a very high twist utilization factor (d) of 97.1%, and the strength of the twisted product is extremely excellent at 17.2 cN / dtex. The polyketone twisted product also had extremely excellent twist strength utilization rate (h) and strength.
[0078]
[Example 17]
In Example 14, twisting was performed in the same manner except for twisting three twisted polyketone twisted products.
The obtained polyketone twisted product (twisting factor 20248) has a very high twist utilization factor (h) of 84.1%, and the strength of the twisted product is extremely excellent at 14.9 cN / dtex. The polyketone twisted product also had extremely excellent twist strength utilization rate (h) and strength.
[0079]
[Comparative Example 12]
Using the polyketone fiber produced in Comparative Example 9, twisting of 390 times / m was performed for both upper twisting and lower twisting under the same conditions as in Example 14.
The twisting property was poor and a large number of fluff was generated during twisting. Further, the obtained polyketone twisted product (twisting factor 22714) had a twist strength utilization rate (h) of 60.5%, which was insufficient as compared with the polyketone twisted product of the present invention.
Further, the twist strength utilization rate (h) and the twist strength of the twisted product after the RFL solution treatment were insufficient as compared with the polyketone twisted product of the present invention.
[Comparative Example 13]
In Comparative Example 12, twisting was performed in the same manner except that the number of twisted yarns was 290 times / m for both the upper and lower twists.
The twisting property was poor and a large number of fluff was generated during twisting. The obtained polyketone twisted product (twisting factor 16890) had a twist strength utilization rate (h) of 77.9%, which was insufficient as compared with the polyketone twisted product of the present invention. Further, the twist strength utilization rate (h) and the twist strength of the twisted product after the RFL solution treatment were insufficient as compared with the polyketone twisted product of the present invention.
[0080]
[Comparative Example 14]
Using the polyketone fiber produced in Comparative Example 10, twisting of 390 times / m was performed for both upper twisting and lower twisting under the same conditions as in Example 14.
The obtained polyketone twisted product (twisting factor 22807) has a twist strength utilization rate (h) of 62.5%, and the strength of the twisted product is 5.1 cN / dtex, which is significantly inferior to the polyketone twisted product of the present invention. It was. Further, the twist strength utilization rate (h) and the twist strength of the twisted product after the RFL liquid treatment were significantly inferior to those of the polyketone twisted product of the present invention.
[Comparative Example 15]
Thirty polyketone fibers produced in Comparative Example 2 were combined, and under the same conditions as in Example 14, twisting of 390 turns / m was performed for both upper twisting and lower twisting.
There was a lot of slack in the twisted yarn, and fluff frequently occurred during twisting, and it was not possible to obtain a twisted yarn of sufficient quality.
[0081]
[Comparative Example 16]
Using the polyketone fiber produced in Comparative Example 8, twisting of 390 times / m was performed for both the upper twist and the lower twist under the same conditions as in Example 14.
The twisting property was poor and a large number of fluff was generated during twisting. The obtained polyketone twisted product (twisting coefficient 21211) has a twist strength utilization rate (h) of 64.9%, which is inferior to that of the polyketone twisted product of the present invention, and has a lot of fluff and poor quality. It was a mixture of fluff and fibrils.
[Comparative Example 17]
Using the polyketone fiber produced in Comparative Example 11, twisting of 390 times / m was performed for both upper twisting and lower twisting under the same conditions as in Example 14.
The obtained polyketone twisted product (twist coefficient 21854) had a twisted yarn strength utilization rate (h) of 63.1%, which was significantly inferior to the polyketone twisted product of the present invention. Although the strength of the raw yarn was equivalent to that in Example 14, the strength of the twisted yarn was quite inferior at 10.6 cN / dtex. Further, the twist strength utilization rate (h) and the twist strength of the twisted product after the RFL liquid treatment were significantly inferior to those of the polyketone twisted product of the present invention.
[0082]
[Table 1]

Table 1 is a table | surface which shows the characteristic of the polyketone fiber of this invention, and the polyketone fiber of a comparative example.
[0083]
[Table 2]

[0084]
(Note) *; Twisted yarn strength utilization after REL treatment (h) = Sum of strength of REL-treated twisted yarn / Strength of polyketone fiber used for twisting yarn
**; Formula (3) = 100 * (1-4.79 * 10)^-9× K^1.78)
Table 2 is a table | surface which shows the characteristic of the polyketone polyketone twisted material of this invention, and the polyketone twisted material of a comparative example.
[0085]
【The invention's effect】
The polyketone fiber of the present invention has excellent mechanical properties such as high strength and high elastic modulus, is free of single yarn sticking, has a small coefficient of dynamic friction between fibers and fibers, is homogeneous and has few defects, and has excellent twisted yarn strength. It is a fiber that has a high rate, expresses high strength even after twisting, and has excellent fatigue resistance.
By making the polyketone fiber of the present invention a twisted product, it can be used in a wide range of fields as high-strength industrial materials (for example, civil engineering / industrial materials such as nets, nets, ropes and cables, rubber reinforcing materials such as tires, belts and hoses, and plastic reinforcement It is expected to develop into reinforcing materials such as fibers).
In particular, it is extremely useful as a reinforcing material such as a rubber reinforcing material for tires, belts, hoses, and FRP, which is subjected to a high mechanical load and requires high strength for a twisted yarn as a reinforcing material.

Claims (9)

A polyketone fiber in which 95 to 100% by mass of the repeating unit is composed of 1-oxotrimethylene represented by the following structural formula (I) is attached to the surface, and satisfies the following requirements a to e Polyketone fiber characterized by that.
(A): Crystallinity ≧ 60%
(B): Crystal orientation degree ≧ 90%
(C): Tensile strength ≧ 10 cN / dtex
(D): Single yarn sticking rate ≦ 30%
(E): Finishing agent adhesion rate = 0.3-15% by mass
( F): Fiber-fiber dynamic friction coefficient = 0.01-0.5

The polyketone fiber according to claim 1 , wherein the polyketone fiber is an aggregate of single yarns having a round cross section, and the roundness (g) of the cross section is 1.0 to 1.2. The polyketone fiber according to claim 1 or 2, wherein the single yarn fineness is 0.8 to 2 dtex. The polyketone fiber according to claim 1, which is obtained by wet spinning using a metal salt solution as a solvent . Short fiber comprising the polyketone fiber according to any one of claims 1 to 4 , wherein the average fiber length is 0.1 to 100 mm. Claim 1 contains at least a portion of the polyketone fiber according to any one of 5, polyketone twist yarn product fibers constituting the twisted product is characterized in that it is twisted at a rate of more than 10 times / m. The polyketone twisted product according to claim 6 , wherein 0.1 to 10% by mass of resorcin-formalin-latex resin is attached to the polyketone fiber. A molded product comprising the polyketone fiber according to any one of claims 1 to 4 and / or the polyketone twisted product according to claim 6 or 7 . The molded article according to claim 8 , wherein the molded article is a rubber product selected from the group of tires, belts, hoses, and endless track bodies.