JP4343367B2 - Polyurethane urea elastic fiber with excellent heat resistance - Google Patents

Description

【００１０】
（式中ＸおよびＹは、それぞれ−（ＣＨ₂ ）ｎ−を示し、ｎは１〜３の整数を示す）。
本発明によるポリウレタンウレア弾性繊維は、高弾性、高伸度を有し、しかもこの高度弾性性能が繊維が高温高湿の繊維の加工条件のもとで損なわれることのない、高耐熱性のポリウレタンウレア弾性繊維である。
【００１１】
本発明によるポリウレタンウレア弾性繊維は、さらに、ポリウレタンウレアを構成するジイソシアネートとポイマージオールのモル比（ｎ）が１．７〜２．３の範囲の高ｎ値のポリマー溶液でも、製造工程中で安定した粘度を維持して紡糸することができる。
本発明によるポリウレタンウレア弾性繊維は、上述した設計にしたがって調製されるポリウレタンウレアの溶液を、一般的には、湿式紡糸もしくは乾式紡糸法を適用して調製することができる。
【００１２】
繊維形成に用いられるポリウレタンウレアは、両末端イソシアネートプレポリマーを有機ジイソシアネートと数平均分子量１，０００〜１０，０００のポリマージオールとの反応で先ず調製し、ついでこの両末端にイソシアネートを有するプレポリマーに前記した特定のジアミンを含むジアミン混合物でなる鎖延長剤を反応させることで調製される。
【００１３】
以下に具体態様について説明すると、まずポリマージオールに過剰モルのジイソシアネート基を反応させて、両末端基にイソシアネート基を有する中間重合体であるプレポリマーを合成する。本発明でいう過剰モルとは、本発明で用いられるジイソシアネートのモル量／ポリマージオールのモル量の比、すなわちモル比（ｎ値）が１．７〜２．３で、好ましくは１．７２〜２．０である。ｎ値が１．７より小さい組成では、高温熱処理における弾性低下が激しい。また、ｎ値が２．３より大きい組成では、ポリマーのゲル化を防ぐことは難しい。
【００１４】
通常、ポリマージオールに対してジイソシアネートを溶剤の存在下または、非存在下、反応温度０℃から１００℃の好適な温度で反応させ、両末端がイソシアネート基であるプレポリマーを得る。この場合、錫系有機化合物等のウレタン化反応を促進する触媒あるいは、アロファネート、ビュレット等の副反応を抑制する酸性の無機または有機化合物からなる負触媒を使用することもできる。
【００１５】
ここにジイソシアネートとしては、下記の化合物群を含む多くの化合物の例が知られている。例えば、ｍ−およびｐ−フェニレンジイソシアネート、２，４−及び２，６−トリレンジイソシアネート、ｍ−及びｐ−キシリレンジイソシアネート、４，４′−ジフェニルメタンジイソシアネート、４，４′−ジフェニル−ジメチルメタンジイソシアネート、４，４′−ジフェニルエーテルジイソシアネート、ナフチレン−１，５−ジイソシアネート、１，６−ヘキサメチレンジイソシアネート、４，４′−シクロへキシレンジイソシアネート、１，３−ビス（α、αジメチルイソシアネートメチル）ベンゼン、１，４−ビス（α、αジメチルイソシアネートメチル）ベンゼン、テトラクロロ−ｍ−及びｐ−キシリレンジイソシアネート、イソホロンジイソシアネート、等が挙げられる。好ましくは、ベンゼン環を有する、またはシクロヘキサン環を有するジイソシアネート化合物で特に４，４′−ジフェニルメタンジイソシアネートが好ましい。
【００１６】
本発明における数平均分子量１，０００〜１０，０００のポリマージオールの例としては、エチレンオキサイド、プロピレンオキサイド、テトラヒドロフラン、メチルテトラヒドロフラン、オキセタン、メチルオキセタン、ジメチルオキセタン等の開環重合可能な単量体を重合して得られる単独重合体または共重合体、または、開環重合可能な単量体と１分子に２個以上の水酸基を有する化合物例えば炭素原子数２から１０の直鎖または分岐したアルキレングリコール類、具体的な一例として、テトラヒドロフランとネオペンチルグリコールを重合して得られる共重合体等のポリエーテルジオールや、アジピン酸、セバチン酸、マレイン酸、イタコン酸、等から選ばれる１種以上の二塩基酸とエチレングリコール、プロピレングリコール、１，４−ブタンジオール、ヘキサメチレングリコール、ネオペンチルグリコール、ジエチレングリコールの如きグリコール類の１種以上とから得られるポリエステルジオールや、ポリ−ε−カプロラクトンジオール、炭素原子数２から１０の直鎖または分岐したアルキレングリコール類を原料にしたポリカーボネートジオール、ポリエーテルエステルジオール、ポリエーテルカーボネートジオール、ポリエステルカーボネートジオール等の単独または共重合物である。好ましい例は、数平均分子量１，０００〜１０，０００のポリエーテルジオール類、特に好ましいのは、数平均分子量１，５００〜２，２００のポリテトラメチレンエーテルグリコール（ＰＴＭＧ）である。
【００１７】
中間重合体すなわちプレポリマーを合成した後、次いで、両末端基にイソシアネート基を有するプレポリマーと２官能性ジアミン混合物により鎖延長反応を行いポリウレタンウレアが得られる。
この際、本発明では、前述したように、鎖延長剤が二種のジアミンの混合物を用いる。第一のジアミンはエチレンジアミン、且つ第二のジアミンとして一般式（１）で示されるジアミンを用いることが肝要である。この組み合わせによってポリマー中のハードセグメントにおける水素結合が抑制され、高ｎ値のポリマー組成においても粘度の経時的上昇が見られない。一般式（１）のジアミンの中でも、Ｘ＝１、Ｙ＝１である化合物１，３−ビスアミノメチルシクロヘキサン（１，３−ＢＡＣ）が特に好ましい。ＸまたはＹが、４以上であるジアミン化合物は、粘度上昇の抑制効果が著しく低下する傾向がある。
【００１８】
混合するジアミンの例として、更に、１，３−ジアミノシクロヘキサン、１，３−プロピレンジアミン、２−メチル−１，５−ペンタンジアミンが挙げられる。しかし、これらのジアミン混合物は、ｎ値が１．７以上のプレポリマー組成で、ポリマーの数平均分子量４５，０００以上では、ポリウレタンウレア溶液の粘度上昇の抑制効果は十分ではない。また、１，３−ジアミノシクロヘキサン、１，３−プロピレンジアミン、２−メチル−１，５−ペンタンジアミンの含有量を増やすことにより、ポリマー粘度上昇の抑制効果は高くなるが、弾性特性が低下し、耐熱性が低下してしまうことが認められた。
【００１９】
本発明におけるエチレンジアミンと一般式（１）のジアミンの混合比としては、全ジアミンに対して一般式（１）のジアミンが１０〜３０モル％の範囲であることが好ましい。１５〜２０モル％であることがさらに好ましい。一般式（１）のジアミンの含有量が１０モル％より小さいと粘度上昇抑制効果が不足しポリマー溶液のゲル化が発生する。また、３０モル％以上では耐熱切断秒数が低下し、熱セット工程で断糸が発生する。
【００２０】
鎖延長剤の添加時に、１官能性アミン化合物を加え末端停止反応によりポリマー分子量の調整を行って、ポリウレタンウレア重合体を得ることもできる。この場合、プレポリマー中のイソシアネート基の当量に対する２官能性ジアミン混合物のアミノ反応基当量または２官能性ジアミン混合物と１官能性アミン化合物の合計のアミノ反応基当量は、ほぼ等しいか、アミノ反応基当量が過剰でもよい。
【００２１】
また、イソシアネート基に対して、２官能性ジアミン混合物を過剰に用いて、２官能性ジアミン混合物を、１官能性アミン化合物として反応させることも可能である。すなわち、この場合、イソシアネート基当量に対して、２官能性アミン化合物の過剰当量のアミノ基は、片末端アミノ基としてポリマー末端基に未反応のまま存在し、ポリマー分子量調整剤として機能する。
【００２２】
また別の変形態様として、ポリウレタンウレア重合時に、ポリマー分子量調整剤として、１官能性アミン化合物を用いる場合、１官能性アミン化合物類の例として、ジエチルアミン、ジメチルアミン、メチルエチルアミン、メチルイソプロピルアミン、メチル−ｎ−プロピルアミン、ジイソプロピルアミン、メチル−ｎ−ブチルアミン、メチル−イソブチルアミン、メチルイソアミルアミン等があげられる。１官能性アミン化合物を用いる場合、２官能性ジアミン混合物より、先にプレポリマーに加えて反応させても良いし、または、同時に加えて反応させてもよい。１官能性アミン化合物の使用量は、プレポリマーに供給する全アミン当量のうちの４０％当量以下が適当である。
【００２３】
プレポリマーとアミン化合物との反応は、極めて速い。反応を穏やかに行うには、その反応温度は、使用する反応溶媒の融点以上で、かつ溶媒中からプレポリマーが析出しない温度であれば、低温を用いることができる。低融点のポリマージオールを用いる場合、氷点下数十度の低温下での反応も可能である。プレポリマー合成時やプレポリマーとアミン化合物類との反応時に、場合によって溶剤を使用してもよい。溶剤の例として、ジメチルフォルムアミド、ジメチルアセトアミド、ジメチルプロピオンアミド、ジメチルスルフォキシド、Ｎ−メチルピロリドン等があげられる。
【００２４】
溶剤を使用する場合、重合体固形分濃度は、通常２５〜５０重量％である。３０〜４０％がさらに好ましい。２５％以下では乾式紡糸法において溶剤を揮発させるために長い紡糸筒が必要になり工業的ではない。５０％以上ではポリマーのゲル化を防ぐことが難しい。
紡糸に適用される重合体溶液は、さらに、公知の酸化防止剤、着色防止剤、紫外線吸収剤などの安定剤や、酸化チタンの如き顔料、帯電防止剤、紡黴剤などの添加剤や充填剤（ステアリン酸金属塩類、酸化マグネシウム、ハイドロタルサイト、酸化亜鉛）を配合し、乾式又は湿式の紡糸機にて繊維を得ることができる。紡糸された糸条は、仮撚りされた後、油剤や滑剤のステアリン酸塩類等が付与される。油剤の種類は特に限定されないが、ポリジメチルシロキサン、ポリジメチルシロキサンのメチル基の一部を他のアルキル基やフェニル基で置換したジオルガノシロキサン、アミノ基、ビニル基、エポキシ基等を導入した変性ポリシロキサンのオルガノポリシロキサンや鉱物油が好ましい。
【００２５】
【発明の実施の形態】
本発明について、以下具体的に説明する。本発明を実施例で更に詳しく説明するが、本発明はこれに限定されるものではない。
実施例中の特性値の測定法を以下に示す。
〔１〕ポリマーの分子量の測定
ポリマーをジメチルアセトアミド（ＤＭＡＣ）に溶解および希釈し０．５重量％のサンプル溶液を調製する。ゲルパーミエーションクロマトグラフィー（ＧＰＣ）は、ショーデックス社製システム１１を使用して、下記の条件をで測定した。
【００２６】
カラム：ショーデックス社製ＳＢ−８０６Ｍ（２本）およびＳＢ−８０２．５（１本）
溶剤： ＤＭＡＣ
流量： １．０ｍｌ／分
カラム恒温槽温度： ６０℃
サンプル量： １００μｌ
検出器： ＲＩ
数平均分子量（Ｍｎ）および重量平均分子量（Ｍｗ）は、標準ＰＴＭＧ試料により得られた校正値から求めた。
〔２〕ポリマー溶液粘度の測定
東機産業（社）製、Ｅ型粘度計ＲＥ１１０Ｕシステムを用いて、３０℃で測定する。
〔３〕繊維の破断強度、伸度の測定
オリエンテック社製テンシロンＵＴＭ−III −１００型引張試験機を使用し、温度２０℃、湿度６５％の条件で測定した。５ｃｍの試料長のものを、５０ｃｍ／分の速度で伸長したときの破断時の強度・伸度の測定を行う。
〔４〕繊維の耐熱性試験
高温高圧染色機（ＮＩＳＳＥＮ ＣＯＲＰＯＲＡＴＩＯＮ ＴＹＰＥ １２ＬＭＰ−Ｅ）により熱処理を行った。被処理部分５０ｍｍの試験糸を８０％伸長して９０ｍｍとし、染色機内部のポット内でイオン交換水に浸漬させて処理した。処理条件は、内部温度７０℃から２．５℃／分で昇温していき１３０℃で３時間保ち、その後冷却、減圧を行った。染色機より取り出した試験体は、温度２０℃湿度６５％の雰囲気で一昼夜風乾し、処理繊維の下記の物性測定を行った。
【００２７】
▲１▼ 繊維の伸長応力回復率（残留歪）の測定：
オリエンテック社製テンシロンＵＴＭ−III −１００型引張試験機を使用し、温度２０℃、湿度６５％の条件で測定した。１、０００％／分で引っ張り、伸長を３００％までに止め、直ちに回復速度１０００％／分で回復させ、それを３回繰り返し、張力０となった時点での残留歪みを測定した。
【００２８】
▲２▼ 繊維の強力保持率の測定
熱処理前の破断強度に対する熱処理後の破断強度の割合（％）を強力保持率とした。
強力保持率（％）＝（Ｔｓａ／Ｔｓｂ）×１００
Ｔｓａ：熱処理後の破断強度（ｇ）
Ｔｓｂ：熱処理前の破断強度（ｇ）
〔５〕繊維の耐熱切断秒数の測定
被試験部分１４０ｍｍの試験糸を５０％伸長して２１０ｍｍとし、１８０℃の熱体に押当て（接触部分約１０ｍｍ）、切断されるまでの秒数を測定した。
【００２９】
〔実施例１〕
数平均分子量２，０００のＰＴＭＧ２２３ｇと４，４´−ジフェニルメタンジイソシアナート５０．４ｇとを乾燥窒素下で８０℃、３時間、撹拌下で反応させてプレポリマーを得た。これを室温に冷却した後、ジメチルアセトアミド４１４．４ｇを加え、室温で撹拌しながら溶解し、均一なプレポリマー溶液とした。一方、エチレンジアミン、４．３０ｇ、１，３−ＢＡＣ、０．４３ｇ、ジエチルアミン、０．８８ｇをＤＭＡＣ１７．５３ｇに溶解したアミン溶液を調製した。このアミン溶液の混合ジアミンのモル比はエチレンジアミン／１，３ＢＡＣ＝８０／２０である。上記プレポリマー溶液７０７．４ｇに高速撹拌下でアミン液を一気に加えた後、さらにＤＭＡＣを１２０．７ｇ加え、室温下１時間反応させ、濃度３４．１重量％、ｎ値＝１．７５のポリウレタンウレア溶液を得た。
【００３０】
このポリウレタンウレア溶液の分子量をＧＰＣで測定したところＭｗ＝１３９，４４０、Ｍｎ＝４６，４８０であった。重合直後（０日）のポリマー溶液粘度は、２９３０ポイズであった。このポリマー溶液を２５℃で保存した時の、粘度の経時変化（１日、４日、７日）の測定結果を表１に示す。
〔実施例２〕
実施例２では、ジアミンの混合比および最終ポリマー濃度を変えて重合を行った。すなわち、実施例１の方法に準じて、エチレンジアミン／１，３−ＢＡＣ＝８０／２０（モル比）、ｎ値＝１．７５、濃度３０．４重量％のポリマーおよびエチレンジアミン／１，３−ＢＡＣ＝９０／１０（モル比）、ｎ値＝１．７０、濃度３５重量％のポリマー溶液を合成した。これらのポリマーの分子量、溶液粘度および粘度の経日変化（１日、４日、７日）を表１に示す。
【００３１】
〔比較例１〕
実施例１、２における１，３−ＢＡＣの代わりに１，３−ジアミノシクロヘキサン（１，３−ＤＡＣＨ）および１，３−プロピレンジアミン（ＰＤＡ）を用いて、実施例１に準じてポリウレタンウレア溶液を合成した。
すなわち、エチレンジアミン／１，３−ＤＡＣＨ＝９０／１０（モル比）、ｎ値＝１．７０、濃度３５重量％のポリマーおよびエチレンジアミン／ＰＤＡ＝８０／２０（モル比）、ｎ値＝１．７５、濃度３０．４重量％のポリマーを合成した。これらのポリマーの分子量、溶液粘度および粘度の経日変化を表１に示す。
【００３２】
混合ジアミンとして、１、３−ＤＡＣＨおよびＰＤＡを使用したポリマーでは経時的にポリマー粘度が上昇し１０日目以降ではゲル化した。
〔実施例３、比較例２〕
実施例１、２および比較例１により得られた粘稠な重合体溶液に、（対ポリマー固形分重量％、以下同じ）、４，４´−ブチリデン−ビス（３−メチル−６−ｔ−ブチルフェノール）２％）、２−（２´−ヒドロキシ−３´−ｔ−ブチル−５´−メチルフェニル）−５−クロロ−ベンゾトリアゾール０．７％を添加したものを紡糸原液とした。
【００３３】
【表１】

【００３４】
これらの紡糸原液から通常の乾式紡糸により紡糸速度４００ｍ／分で、４４ｄｔｅｘのポリウレタンウレア繊維を得た。その破断強度、破断伸度および耐熱切断秒数の測定結果を表２に示す。これらのポリウレタン繊維を熱処理し、処理前後の強力保持率および処理後の伸長応力回復率を測定した結果を表２に示す。
混合ジアミンとして、１、３−ＤＡＣＨおよびＰＤＡを使用したポリマーでは紡糸原液が一部ゲル化しているため紡糸状態が不安定で、しばしば糸切れが発生した。また、１、３−ＤＡＣＨおよびＰＤＡを使用したポリマーから得られたウレタンウレア弾性糸は、熱処理による弾性特性の低下が１，３−ＢＡＣより大きかった。
【００３５】
【表２】

【００３６】
【発明の効果】
本発明によるポリポリウレタンウレア弾性繊維は、弾性機能および耐熱性に優れ、高温高圧湿熱のポリエステルの染色条件に耐え得るポリウレタンウレア弾性繊維である。本発明によるポリウレタンウレア弾性繊維は、ポリウレタンウレアの保存の安定性に優れており、常温における保存時の粘度変化が小さい紡糸原液を調製することができるので、トラブルを起こさない紡糸、安定した紡糸工程の下で製造することができる。[0001]
BACKGROUND OF THE INVENTION
The present invention has a high elastic force, high elongation and high heat resistance, and maintains a high elastic force and high extensibility especially in dyeing under high temperature and high pressure moist heat conditions. The present invention relates to a polyurethaneurea elastic fiber excellent in moisture and heat resistance suitable for manufacturing clothing.
[0002]
[Prior art]
Polyurethane elastic fibers are mainly knitted with nylon fibers and widely used in fields such as foundations, pantyhose, and socks. However, the use of knitted fabrics of polyester fibers and polyurethane elastic fibers, which are typical general-purpose synthetic fibers, in clothing in the outer field is limited. The main reason is that the dyeing of polyester fibers generally requires a high temperature and high pressure moist heat temperature (about 130 ° C) rather than the dyeing of nylon fibers which are generally dyed at a dyeing temperature of about 100 ° C. The heat resistance performance of the fiber was not sufficient. Therefore, when the polyester fiber / polyurethane elastic fiber mixed product manufactured by the conventional technology is dyed under the normal dyeing conditions of general-purpose polyester fiber, the polyurethane elastic fiber is greatly heat-set (heat set), and the power is greatly reduced. In some cases, the breaking strength is significantly reduced, or in some cases, it is thermally cut. Further, when the heat resistance of the polyurethane elastic fiber is not sufficient, there is a risk that the polyurethane elastic fiber is thermally cut at the time of molding at a high temperature such as coupling of a brassiere.
[0003]
However, in recent years, in the outer clothing field and sports (skiing, skating, golf, etc.) clothing field, composite fabric materials composed of polyester fibers and polyurethane elastic fibers having various elastic patterns are desired.
Polyurethane urea used in the production of polyurethane urea fibers is a polymer prepared by reacting a polymer diol with an excess molar amount of diisocyanate to synthesize a prepolymer having a terminal isocyanate group, and then chain-extending with a diamine compound. Therefore, the hard segment containing strong intermolecular hydrogen bonds is formed by the urea group contained in the polymer, and as is well known, the hard segment in the polymer forms a physical cross-linking point, and the heat resistance of polyurethane urea Improves sex. A polymer formulation that increases the ratio of the molar amount of diisocyanate to the molar amount of polymer diol (n value) to improve the heat resistance and elastic properties to increase the hard segment content can be easily assumed, but the polymer with a high n value In the formulation, the viscosity of the polymer solution must be high, and the viscosity of the polymer solution becomes unstable with time and sometimes gels, making it difficult to industrially use.
[0004]
Use of diamine mixture for chain extension process, such as urethane urea polymer chain extended with 80/20 mol mixture of ethylenediamine and hydrogenated m-phenylenediamine (1,3-diaminocyclohexane) for the purpose of improving heat setting This is disclosed in US Pat. No. 2,929,803, US Pat. No. 3,507,834, and US Pat. No. 3,549,596. It is known that a urethane urea polymer using a diamine mixture used in these known techniques generally has a reduced viscosity and an improved stability over time. However, in the combination of these known diamines, the elastic function of the obtained polyurethane urea elastic fiber is lowered, and it is generally used in a mixed state such as knitting with polyester fiber that requires dyeing at high temperature and high pressure. However, there is a problem that the desired elastic performance is insufficient.
[0005]
Japanese Patent Laid-Open No. 3-97915 discloses a method in which 2-methyl-1,5-pentanediamine is mixed with ethylenediamine for chain extension in the range of 28 to 32 mol%. However, with this diamine combination, when the n value is designed to be 1.7 or more and the number average molecular weight of the polymer is designed to be 45,000 or more, the viscosity stability of the polymer is not sufficient.
[0006]
[Problems to be solved by the invention]
An object of the present invention is to provide a polyurethane urea elastic fiber having high elasticity, high elongation, and high heat resistance. A more specific object of the present invention is to provide polyurethane urea elastic having excellent heat resistance so that the mixed fabric product such as knitting of polyester fiber and polyurethane urea elastic fiber does not lose elastic performance even under high temperature and high pressure dyeing. To provide fiber.
[0007]
[Means for Solving the Problems]
The inventors of the present invention mix a specific diamine represented by the general formula (1), which will be described later, with a commonly used diamine such as ethylenediamine in a part of the chain extender in the preparation of polyurethaneurea in the production of polyurethaneurea elastic fibers. By using the polyurethaneurea obtained by the above, it was found that the elastic performance of the polyurethaneurea elastic fiber was not lowered even when the fiber was exposed to high temperature and high humidity, and the idea of the present invention was obtained.
[0008]
That is, an object of the present invention is to chain a prepolymer comprising a polymer diol having a number average molecular weight of 1,000 to 10,000 and a diisocyanate with a mixed diamine consisting essentially of ethylenediamine and a diamine represented by the general formula (1). It is an extended polyurethaneurea elastic fiber, which is achieved by a polyurethaneurea elastic fiber having a diamine content of general formula (1) in the range of 10 to 30 mol% with respect to the total diamine.
[0009]
[Chemical formula 2]

[0010]
(In the formula, X and Y each represent — (CH ₂ ) n—, where n represents an integer of 1 to 3).
The polyurethane urea elastic fiber according to the present invention has high elasticity and high elongation, and this highly elastic performance does not impair the fiber under high temperature and high humidity fiber processing conditions. Urea elastic fiber.
[0011]
The polyurethaneurea elastic fiber according to the present invention can be used in the production process even in a polymer solution having a high n value in which the molar ratio (n) of diisocyanate and polymer diol constituting polyurethaneurea is in the range of 1.7 to 2.3. Spinning can be performed while maintaining a stable viscosity.
The polyurethaneurea elastic fiber according to the present invention can be prepared by applying a solution of polyurethaneurea prepared according to the above-described design, generally by wet spinning or dry spinning.
[0012]
Polyurethane urea used for fiber formation is prepared by first preparing an isocyanate prepolymer at both ends with an organic diisocyanate and a polymer diol having a number average molecular weight of 1,000 to 10,000, and then forming a prepolymer having isocyanate at both ends. It is prepared by reacting a chain extender comprising a diamine mixture containing the specific diamine described above.
[0013]
A specific embodiment will be described below. First, an excess mole of a diisocyanate group is reacted with a polymer diol to synthesize a prepolymer which is an intermediate polymer having isocyanate groups at both terminal groups. The excess mole in the present invention means the ratio of the molar amount of diisocyanate / the molar amount of polymer diol used in the present invention, that is, the molar ratio (n value) is 1.7 to 2.3, preferably 1.72 to 2.0. When the composition has an n value of less than 1.7, the elastic reduction during high temperature heat treatment is severe. In addition, it is difficult to prevent the gelation of the polymer with a composition having an n value larger than 2.3.
[0014]
Usually, a diisocyanate is reacted with a polymer diol in the presence or absence of a solvent at a suitable temperature between 0 ° C. and 100 ° C. to obtain a prepolymer having both ends being isocyanate groups. In this case, a catalyst for promoting a urethanation reaction such as a tin-based organic compound or a negative catalyst made of an acidic inorganic or organic compound for suppressing side reactions such as allophanate and burette can be used.
[0015]
As diisocyanates, many examples of compounds including the following compound groups are known. For example, m- and p-phenylene diisocyanate, 2,4- and 2,6-tolylene diisocyanate, m- and p-xylylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyl-dimethylmethane diisocyanate 4,4′-diphenyl ether diisocyanate, naphthylene-1,5-diisocyanate, 1,6-hexamethylene diisocyanate, 4,4′-cyclohexylene diisocyanate, 1,3-bis (α, αdimethylisocyanate methyl) benzene, 1,4-bis (α, αdimethylisocyanatomethyl) benzene, tetrachloro-m- and p-xylylene diisocyanate, isophorone diisocyanate, and the like. Preferably, it is a diisocyanate compound having a benzene ring or a cyclohexane ring, and 4,4′-diphenylmethane diisocyanate is particularly preferable.
[0016]
Examples of the polymer diol having a number average molecular weight of 1,000 to 10,000 in the present invention include monomers capable of ring-opening polymerization such as ethylene oxide, propylene oxide, tetrahydrofuran, methyltetrahydrofuran, oxetane, methyloxetane, and dimethyloxetane. A homopolymer or copolymer obtained by polymerization, or a compound having a ring-opening polymerizable monomer and two or more hydroxyl groups in one molecule, for example, a linear or branched alkylene glycol having 2 to 10 carbon atoms As a specific example, a polyether diol such as a copolymer obtained by polymerizing tetrahydrofuran and neopentyl glycol, one or more selected from adipic acid, sebacic acid, maleic acid, itaconic acid, etc. Basic acid and ethylene glycol, propylene glycol, 1 Polyester diol obtained from one or more of glycols such as 4-butanediol, hexamethylene glycol, neopentyl glycol, diethylene glycol, poly-ε-caprolactone diol, linear or branched alkylene having 2 to 10 carbon atoms Polycarbonate diols, polyether ester diols, polyether carbonate diols, polyester carbonate diols or the like, which are made from glycols as raw materials, are homopolymers or copolymers. Preferred examples are polyether diols having a number average molecular weight of 1,000 to 10,000, and particularly preferred is polytetramethylene ether glycol (PTMG) having a number average molecular weight of 1,500 to 2,200.
[0017]
After synthesizing the intermediate polymer, that is, the prepolymer, a polyurethane urea is obtained by performing a chain extension reaction with a mixture of a bifunctional diamine and a prepolymer having isocyanate groups at both terminal groups.
At this time, in the present invention, as described above, the chain extender uses a mixture of two kinds of diamines. It is important to use ethylenediamine as the first diamine and the diamine represented by the general formula (1) as the second diamine. This combination suppresses hydrogen bonding in the hard segment in the polymer, and no increase in viscosity over time is observed even in a polymer composition having a high n value. Among the diamines of the general formula (1), the compound 1,3-bisaminomethylcyclohexane (1,3-BAC) in which X = 1 and Y = 1 is particularly preferable. A diamine compound in which X or Y is 4 or more tends to significantly reduce the effect of suppressing increase in viscosity.
[0018]
Examples of the diamine to be mixed further include 1,3-diaminocyclohexane, 1,3-propylenediamine, and 2-methyl-1,5-pentanediamine. However, these diamine mixtures have a prepolymer composition having an n value of 1.7 or more, and if the number average molecular weight of the polymer is 45,000 or more, the effect of suppressing the increase in the viscosity of the polyurethaneurea solution is not sufficient. Also, increasing the content of 1,3-diaminocyclohexane, 1,3-propylenediamine, 2-methyl-1,5-pentanediamine increases the effect of suppressing the increase in polymer viscosity, but decreases the elastic properties. It was observed that the heat resistance was reduced.
[0019]
As a mixing ratio of the ethylenediamine and the diamine of the general formula (1) in the present invention, the diamine of the general formula (1) is preferably in the range of 10 to 30 mol% with respect to the total diamine. More preferably, it is 15-20 mol%. When the content of the diamine of the general formula (1) is less than 10 mol%, the effect of suppressing the increase in viscosity is insufficient and gelation of the polymer solution occurs. On the other hand, if it is 30 mol% or more, the heat-resistant cutting time decreases, and yarn breakage occurs in the heat setting process.
[0020]
At the time of adding the chain extender, a monofunctional amine compound is added and the molecular weight of the polymer is adjusted by a terminal termination reaction to obtain a polyurethaneurea polymer. In this case, the amino reactive group equivalent of the bifunctional diamine mixture or the total amino reactive group equivalent of the bifunctional diamine mixture and the monofunctional amine compound relative to the equivalent of the isocyanate group in the prepolymer is approximately equal to the amino reactive group. The equivalent may be excessive.
[0021]
It is also possible to react the bifunctional diamine mixture as a monofunctional amine compound by using an excess of the bifunctional diamine mixture with respect to the isocyanate group. That is, in this case, an excess equivalent amount of the amino group of the bifunctional amine compound with respect to the isocyanate group equivalent is present as an unreacted polymer end group as a single terminal amino group, and functions as a polymer molecular weight modifier.
[0022]
As another variation, in the case of using a monofunctional amine compound as a polymer molecular weight regulator during polyurethane urea polymerization, examples of monofunctional amine compounds include diethylamine, dimethylamine, methylethylamine, methylisopropylamine, methyl -N-propylamine, diisopropylamine, methyl-n-butylamine, methyl-isobutylamine, methylisoamylamine and the like. When a monofunctional amine compound is used, it may be added to the prepolymer before the bifunctional diamine mixture, or may be reacted at the same time. The amount of the monofunctional amine compound used is suitably 40% equivalent or less of the total amine equivalent supplied to the prepolymer.
[0023]
The reaction between the prepolymer and the amine compound is extremely fast. In order to carry out the reaction gently, a low temperature can be used as long as the reaction temperature is not lower than the melting point of the reaction solvent used and the prepolymer does not precipitate from the solvent. When a polymer diol having a low melting point is used, a reaction at a low temperature of several tens of degrees below freezing is also possible. In some cases, a solvent may be used during the synthesis of the prepolymer or during the reaction between the prepolymer and the amine compound. Examples of the solvent include dimethylformamide, dimethylacetamide, dimethylpropionamide, dimethyl sulfoxide, N-methylpyrrolidone and the like.
[0024]
When a solvent is used, the polymer solid content concentration is usually 25 to 50% by weight. 30 to 40% is more preferable. If it is 25% or less, a long spinning cylinder is required to evaporate the solvent in the dry spinning method, which is not industrial. If it is 50% or more, it is difficult to prevent gelation of the polymer.
The polymer solution applied to the spinning further includes stabilizers such as known antioxidants, anti-coloring agents, ultraviolet absorbers, additives such as pigments such as titanium oxide, antistatic agents, spinners, and fillers. An agent (metal stearate, magnesium oxide, hydrotalcite, zinc oxide) is blended, and fibers can be obtained with a dry or wet spinning machine. The spun yarn is false twisted and then provided with oil or lubricant stearates. The type of oil agent is not particularly limited, but polydimethylsiloxane, polydimethylsiloxane modified by introducing a part of the methyl group with another alkyl group or phenyl group, an amino group, a vinyl group, an epoxy group, etc. Polysiloxane organopolysiloxanes and mineral oils are preferred.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be specifically described below. The present invention will be described in more detail with reference to examples, but the present invention is not limited thereto.
The measuring method of the characteristic value in an Example is shown below.
[1] Measurement of polymer molecular weight A polymer is dissolved and diluted in dimethylacetamide (DMAC) to prepare a 0.5 wt% sample solution. Gel permeation chromatography (GPC) was measured under the following conditions using a system 11 manufactured by Shodex.
[0026]
Column: SB-806M (two) and SB-802.5 (one) manufactured by Shodex
Solvent: DMAC
Flow rate: 1.0 ml / min Column temperature chamber temperature: 60 ° C
Sample volume: 100 μl
Detector: RI
The number average molecular weight (Mn) and the weight average molecular weight (Mw) were determined from calibration values obtained with standard PTMG samples.
[2] Measurement of polymer solution viscosity Measured at 30 ° C. using an E-type viscometer RE110U system manufactured by Toki Sangyo Co., Ltd.
[3] Measurement of breaking strength and elongation of fiber Using a Tensilon UTM-III-100 type tensile tester manufactured by Orientec Co., Ltd., measurement was performed under conditions of a temperature of 20 ° C. and a humidity of 65%. The strength and elongation at break are measured when a sample having a length of 5 cm is stretched at a speed of 50 cm / min.
[4] Heat resistance test of fiber Heat treatment was performed with a high-temperature and high-pressure dyeing machine (NISSEN CORPORATION TYPE 12LMP-E). A test yarn of 50 mm to be treated was stretched by 80% to 90 mm, and was treated by immersing it in ion exchange water in a pot inside the dyeing machine. The treatment conditions were as follows: the internal temperature was raised from 70 ° C. at 2.5 ° C./min, maintained at 130 ° C. for 3 hours, and then cooled and decompressed. The specimen taken out from the dyeing machine was air-dried all day and night in an atmosphere of a temperature of 20 ° C. and a humidity of 65%, and the following physical properties of the treated fiber were measured.
[0027]
(1) Measurement of elongation stress recovery rate (residual strain) of fiber:
Using a Tensilon UTM-III-100 type tensile tester manufactured by Orientec Co., Ltd., measurement was performed under conditions of a temperature of 20 ° C. and a humidity of 65%. The sample was pulled at 1,000% / min, the elongation was stopped to 300%, and immediately recovered at a recovery rate of 1000% / min. This was repeated three times, and the residual strain when the tension became zero was measured.
[0028]
(2) Measurement of fiber strength retention ratio The ratio (%) of the breaking strength after heat treatment to the breaking strength before heat treatment was defined as the strength retention.
Strength retention (%) = (Tsa / Tsb) × 100
Tsa: Breaking strength after heat treatment (g)
Tsb: Breaking strength before heat treatment (g)
[5] Measurement of heat-resistant cutting time of the fiber The test yarn of the part to be tested 140 mm is stretched by 50% to 210 mm, pressed against a heat body at 180 ° C. (contact part approximately 10 mm), and the number of seconds until it is cut. It was measured.
[0029]
[Example 1]
223 g of PTMG having a number average molecular weight of 2,000 and 50.4 g of 4,4′-diphenylmethane diisocyanate were reacted under dry nitrogen at 80 ° C. for 3 hours with stirring to obtain a prepolymer. After cooling this to room temperature, 414.4 g of dimethylacetamide was added and dissolved with stirring at room temperature to obtain a uniform prepolymer solution. On the other hand, an amine solution in which ethylenediamine, 4.30 g, 1,3-BAC, 0.43 g, diethylamine and 0.88 g were dissolved in 17.53 g of DMAC was prepared. The molar ratio of the mixed diamine in this amine solution is ethylenediamine / 1,3BAC = 80/20. After adding an amine solution to 707.4 g of the above prepolymer solution at high speed with stirring at a stretch, 120.7 g of DMAC was further added and reacted at room temperature for 1 hour to give a polyurethane having a concentration of 34.1% by weight and an n value = 1.75. A urea solution was obtained.
[0030]
When the molecular weight of this polyurethane urea solution was measured by GPC, it was Mw = 139,440 and Mn = 46,480. The polymer solution viscosity immediately after polymerization (day 0) was 2930 poise. Table 1 shows the measurement results of changes in viscosity over time (1 day, 4 days, and 7 days) when this polymer solution was stored at 25 ° C.
[Example 2]
In Example 2, the polymerization was carried out by changing the mixing ratio of the diamine and the final polymer concentration. That is, according to the method of Example 1, ethylenediamine / 1,3-BAC = 80/20 (molar ratio), n value = 1.75, concentration 30.4% by weight of polymer and ethylenediamine / 1,3-BAC = 90/10 (molar ratio), n value = 1.70, and a polymer solution having a concentration of 35% by weight was synthesized. Table 1 shows the molecular weight, solution viscosity, and viscosity change over time (1, 4, and 7 days) of these polymers.
[0031]
[Comparative Example 1]
A polyurethane urea solution according to Example 1 using 1,3-diaminocyclohexane (1,3-DACH) and 1,3-propylenediamine (PDA) instead of 1,3-BAC in Examples 1 and 2 Was synthesized.
That is, ethylenediamine / 1,3-DACH = 90/10 (molar ratio), n value = 1.70, polymer having a concentration of 35% by weight and ethylenediamine / PDA = 80/20 (molar ratio), n value = 1.75. A polymer with a concentration of 30.4% by weight was synthesized. Table 1 shows the molecular weight, solution viscosity, and change in viscosity with time of these polymers.
[0032]
In the polymer using 1,3-DACH and PDA as the mixed diamine, the polymer viscosity increased with time and gelled after the 10th day.
[Example 3, Comparative Example 2]
To the viscous polymer solutions obtained in Examples 1 and 2 and Comparative Example 1, (% by weight of polymer solids, the same shall apply hereinafter), 4,4′-butylidene-bis (3-methyl-6-t- (Butylphenol) 2%), 2- (2'-hydroxy-3'-t-butyl-5'-methylphenyl) -5-chloro-benzotriazole 0.7% was used as the spinning dope.
[0033]
[Table 1]

[0034]
From these spinning stock solutions, 44 dtex polyurethane urea fibers were obtained at a spinning speed of 400 m / min by ordinary dry spinning. Table 2 shows the measurement results of the breaking strength, breaking elongation and heat-resistant cutting time. Table 2 shows the results of heat-treating these polyurethane fibers and measuring the strength retention before and after the treatment and the elongation stress recovery rate after the treatment.
In a polymer using 1,3-DACH and PDA as a mixed diamine, the spinning stock solution was partially gelled, so that the spinning state was unstable, and yarn breakage often occurred. Moreover, the urethane urea elastic yarn obtained from the polymer using 1,3-DACH and PDA had a larger decrease in elastic properties due to heat treatment than 1,3-BAC.
[0035]
[Table 2]

[0036]
【The invention's effect】
The polyureaurea elastic fiber according to the present invention is a polyurethaneurea elastic fiber that is excellent in elastic function and heat resistance and can withstand the dyeing conditions of high-temperature, high-pressure, and high-humidity polyester. The polyurethaneurea elastic fiber according to the present invention is excellent in storage stability of polyurethaneurea, and can prepare a spinning stock solution having a small viscosity change during storage at room temperature. Therefore, spinning without causing trouble, stable spinning process Can be manufactured under.

Claims (2)

A polyurethane urea elastic fiber in which a prepolymer comprising a polymer diol having a number average molecular weight of 1,000 to 10,000 and a diisocyanate is chain-extended with a mixed diamine consisting essentially of ethylenediamine and 1,3-bisaminomethylcyclohexane. A polyurethane elastic fiber, wherein the content of 1,3-bisaminomethylcyclohexane is in the range of 10 to 30 mol% with respect to the total diamine.   The molar amount of diisocyanate / molar amount of polymer diol (n value) is in the range of 1.7 to 2.3, and the number average molecular weight of the polymer is 45,000 or more. Polyurethane elastic fiber.