JP3603790B2 - Thermoplastic elastomer composition and method for producing the same - Google Patents

Description

【００４８】
尚、ｎは０〜１０の整数であり、Ｘはヒドロキシル基、ハロゲン化アルキル基及びハロゲン原子の少なくともいずれかであり、Ｒは炭素数１〜１５の飽和炭化水素基である。
【００４９】
尚、ｐ−置換フェノール系化合物は、アルカリ触媒の存在下においてｐ−置換フェノールとアルデヒド（好ましくはホルムアルデヒド）との縮合反応により得られる。
架橋剤として、フェノール系架橋剤を用いる場合は、上記べースポリマー（Ｄ１）１００質量部に対して好ましくは０．２〜１０質量部、より好ましくは０．５〜５質量部とすることができる。フェノール系架橋剤の使用量が０．２質量部未満であると、射出融着時の接着性及び射出融着により得られる成形体の弾性回復性が低下する傾向にある。一方、１０質量部を超えると、熱可塑性エラストマー組成物の押出加工性及び射出加工性等が低下する傾向にある。
【００５０】
これらのフェノール系架橋剤は単独でも使用できるが、架橋速度を調節するため、架橋促進剤を併用することができる。この架橋促進剤としては、金属ハロゲン化物（塩化第一すず、塩化第二鉄等）、有機ハロゲン化物（塩素化ポリプロピレン、臭化ブチルゴム、クロロプレンゴム等）等が挙げられる。
また、架橋促進剤の他、更に、酸化亜鉛等の金属酸化物やステアリン酸等の分散剤を併用することがより望ましい。
【００５１】
請求項２記載の熱可塑性エラストマー組成物は、エチレン・α−オレフィン系共重合ゴム（Ａ）３０〜７０質量％及び鉱物油系軟化剤（Ｂ２）３０〜７０質量％〔但し、（Ａ）＋（Ｂ２）＝１００質量％〕からなる油展ゴム（Ｘ）３０〜９９質量部と、鉱物油系軟化剤（Ｂ１）０〜５０質量部と、α−オレフィン系結晶性熱可塑性樹脂（ｃ１）及び／又はα−オレフィン系非晶質熱可塑性樹脂（ｃ２）で構成されるα−オレフィン系熱可塑性樹脂（Ｃ）１〜５０質量部と、からなるベースポリマー（Ｄ２）を１００質量部とした場合、ＪＩＳ Ｋ２２８３で規定される２５℃における粘度が１００００ｃＳｔ未満である未変性オルガノポリシロキサン（Ｅ１）１〜１０質量部と、粘度が１００００ｃＳｔ以上である未変性オルガノポリシロキサン（Ｆ１）１〜１０質量部と、アクリル変性オルガノポリシロキサン（Ｇ）０．２〜２０質量部と、を混合して得られる樹脂・ゴム組成物（Ｈ２）を架橋剤の存在下で動的に熱処理してなることを特徴とする。
【００５２】
上記油展ゴム（Ｘ）は、上記共重合ゴム（Ａ）と上記鉱物油系軟化剤（Ｂ２）からなる。上記油展ゴム（Ｘ）を構成する上記共重合ゴム（Ａ）と上記鉱物油系軟化剤（Ｂ２）の配合量の組み合わせは、好ましくは上記成分（Ａ）が３５〜６５質量％、上記成分（Ｂ２）が３５〜６５質量％、より好ましくは上記成分（Ａ）が４０〜６０質量％、上記成分（Ｂ２）が４０〜６０質量％である。上記成分（Ａ）の配合量が３０質量％未満であるかあるいは上記成分（Ｂ２）の配合量が７０質量％を超えると最終的に得られる熱可塑性エラストマー組成物から軟化剤がブリードアウトしたり、機械的物性及びゴム弾性が低下する傾向にある。一方、上記成分（Ａ）の配合量が７０質量％を超えるかあるいは上記成分（Ｂ２）の配合量が３０質量％未満では最終的に得られる熱可塑性エラストマー組成物の成形加工性が低下する傾向にある。尚、上記エチレン・α−オレフィン系共重合ゴム（Ａ）と上記鉱物油系軟化剤（Ｂ２）としては前記に例示したものを用いることができる。
【００５３】
上記共重合ゴム（Ａ）は、請求項３に示すように、デカリン溶媒中１３５℃で測定した場合の極限粘度〔η〕が３．５〜６．８ｄｌ／ｇ（より好ましくは４．３〜６．０ｄｌ／ｇ）である。この極限粘度が３．５ｄｌ／ｇ未満であると弾性回復性が低下する傾向にあり、一方、６．８ｄｌ／ｇを超えると成形時の加工性が低下する傾向にあり好ましくない。更に、上記共重合ゴム（Ａ）のＸ線回折測定による結晶化度は２０％以下（より好ましくは１５％以下）であることが好ましい。結晶化度が２０％を超える場合は共重合ゴムの柔軟性が低下する傾向があり好ましくない。
また、上記共重合ゴム（Ａ）がエチレン・α−オレフィン・非共役ジエン三元共重合体である場合、よう素価は５〜３０（より好ましくは７〜２０）であることが好ましい。
【００５４】
請求項２記載の熱可塑性エラストマー組成物に係わる上記ベースポリマー（Ｄ２）は、上記油展ゴム（Ｘ）、必要に応じて鉱物油系軟化剤（Ｂ１）、上記α−オレフィン系熱可塑性樹脂（Ｃ）を含有する。これらの合計を１００質量部とした場合、上記油展ゴム（Ｘ）を３０〜９９質量部（好ましくは３５〜９７質量部、より好ましくは４０〜９５質量部）、鉱物油系軟化剤（Ｂ１）を０〜５０質量部（好ましくは０〜４５質量部、より好ましくは０〜４０質量部）、α−オレフィン系熱可塑性樹脂（Ｃ）を１〜５０質量部（好ましくは２〜４５質量部、より好ましくは５〜４０質量部）を含有する。尚、上記鉱物油系軟化剤（Ｂ１）及び上記α−オレフィン系熱可塑性樹脂（Ｃ）としては、前記に例示したものを用いることができる。
【００５５】
上記油展ゴム（Ｘ）の配合量が３０質量部未満であると、得られる熱可塑性エラストマーの柔軟性が低下する傾向にある。一方、上記油展ゴム（Ｘ）の配合量が９９質量部を超えると、架橋剤の存在下で熱処理して得られた熱可塑性エラストマー組成物の流動性が低下し、成形加工性が著しく悪化する。
後に添加する上記鉱物油系軟化剤（Ｂ１）の配合量が５０質量部を超えると、練り機内で上記油展ゴム（Ｘ）を構成する共重合ゴム（Ａ）とα−オレフィン系熱可塑性樹脂（Ｃ）との分散不良を起こす傾向にあるうえ、最終的に得られる本発明の熱可塑性エラストマー組成物のゴム弾性が悪化する。
【００５６】
上記α−オレフィン系熱可塑性樹脂（Ｃ）の配合量が１質量部未満であると、架橋剤の存在下で熱処理した場合、動的架橋型熱可塑性エラストマーの特徴である良好な海島構造のモルフォロジーが形成されず熱可塑性エラストマーにならない。一方、上記α−オレフィン系熱可塑性樹脂（Ｃ）の配合量が５０質量部を超えると得られる熱可塑性エラストマーの柔軟性とゴム弾性が低下し好ましくない。上記α−オレフィン系結晶性熱可塑性樹脂（ｃ１）と上記α−オレフィン系非晶質熱可塑性樹脂（ｃ２）は、どちらか一方をあるいは両方を混合して使用してもよい。
【００５７】
請求項２記載の熱可塑性エラストマー組成物に係わる上記（Ｅ１）及び（Ｆ１）で表される未変性オルガノポリシロキサンとしては、前記に例示したものを用いることができる。
上記未変性オルガノポリシロキサン（Ｅ１）の配合量は、熱可塑性エラストマー組成物のべースポリマー（Ｄ２）１００質量部に対して１〜１０質量部、好ましくは１〜８質量部、より好ましくは１〜５質量部である。尚、ＪＩＳ Ｋ２２８３で規定される２５℃における粘度が１００００ｃＳｔ未満の未変性オルガノポリシロキサン（Ｅ１）を単独で使用すると、オルガノポリシロキサンがブリードアウトする原因となる。
上記未変性オルガノポリシリキサン（Ｆ１）の配合量は、上記べースポリマー（Ｄ２）１００質量部に対して１〜１０質量部、好ましくは１〜８質量部、より好ましくは１〜５質量部である。尚、ＪＩＳ Ｋ２２８３で規定される２５℃における粘度が１００００ｃＳｔ以上のオルガノポリシロキサン（Ｆ１）を単独で使用すると、摺動性が不足する傾向を示し、好ましくない。
【００５８】
ＪＩＳ Ｋ２２８３で規定される２５℃における粘度が１００００ｃＳｔ未満の未変性オルガノポリシロキサン（Ｅ１）と１００００ｃＳｔ以上の未変性オルガノポリシロキサン（Ｆ１）を併用することで摺動性が著しく向上する。これらの配合量の組み合わせとしては、好ましくは上記（Ｅ１）が１〜１０質量部、上記（Ｆ１）が１〜１０質量部、より好ましくは上記（Ｅ１）が１〜５質量部、上記（Ｆ１）が１〜５質量部である。
【００５９】
請求項２記載の熱可塑性エラストマー組成物に係わる上記（Ｇ）で表されるアクリル変性オルガノポリシロキサンとしては、前記に例示したものを用いることができる。上記アクリル変性オルガノポリシロキサン（Ｇ）の配合量は、上記べースポリマー（Ｄ２）を１００質量部とした場合、０．２〜２０質量部であり、好ましくは０．５〜１５質量部、より好ましくは１〜１０質量部である。このアクリル変性オルガノポリシロキサン（Ｇ）は、摺動性を付与する効果よりも、熱可塑性エラストマー組成物のべースポリマー（Ｄ２）とオルガノポリシロキサンとの相溶化剤として機能する。そのため、上記アクリル変性オルガノポリシロキサン（Ｇ）の配合量が０．２質量部未満では、相溶化が上手くいかず、混練機中で上記未変性オルガノポリシロキサン（Ｅ）及び（Ｆ）と、べースポリマー（Ｄ２）との分散不良が起こったり、押出成形や射出成形等の成形加工性が悪化する傾向にある。一方、２０質量部を超えると柔軟性や物性が低下する傾向にある。
【００６０】
請求項２記載の熱可塑性エラストマー組成物は、上記（Ｘ）及び上記（Ｃ）〜（Ｇ）を混合して得られる樹脂・ゴム組成物（Ｈ２）を架橋剤の存在下で動的に熱処理される。ここで用いられる架橋剤としては特に限定されないが、動的熱処理により、上記共重合ゴム（Ａ）を架橋できるものであれば特に限定されない。架橋剤の例示及び使用量は、前記と同様である。
【００６１】
本発明の熱可塑性エラストマー組成物には、適宜、補強材（カーボンブラック、シリカ等）、充填材（クレー、タルク、炭酸カルシウム等）、加工助剤、着色剤、酸化防止剤、紫外線吸収剤、老化防止剤、熱安定剤、滑剤、離型剤、難燃剤、発泡剤、帯電防止剤、防かび剤等の添加剤等を配合することができる。更に、上記共重合ゴム（Ａ）、上記鉱物油系軟化剤（Ｂ１及びＢ２）、上記α−オレフィン系熱可塑性樹脂（Ｃ）の他にも、例えば、天然ゴム、ポリイソプレンゴム、ポリブタジエンゴム、スチレン−ブタジエンゴム、アクリロニトリル−ブタジエンゴム、ブチルゴム、アクリルゴム等を添加してもよい。
【００６２】
請求項４記載の熱可塑性エラストマーの製造方法は、請求項１乃至３のいずれかに記載の樹脂・ゴム組成物に架橋剤を配合し、これを連続式押出機又は密閉式混練機に供給し、動的に熱処理することを特徴とする。
上記架橋剤としては、前記に例示したものを用いることができる。
【００６３】
上記「動的に熱処理する」とは、剪断力を加えること及び加熱することの両方を行うことをいう。この動的熱処理は、例えば、溶融混練装置を用いて行うことができる。このうち混練を行うことのできる装置としては、例えば、開放型のミキシングロール、非開放型のバンバリーミキサー、一軸押出機、二軸押出機、ニーダー等の装置を挙げることができる。これらのうち、経済性、処理効率等の観点から一軸押出機及び／又は二軸押出機を用いることが好ましい。この混練装置で行う処理はバッチ式でも連続式であってもよい。
【００６４】
上記連続式押出機としては上記熱可塑性エラストマー組成物を架橋剤の存在下で溶融混練することができるならば特に限定されず、例えば、一軸押出機、二軸押出機、二軸ローター型押出機等が挙げられる。これらのうち、二軸押出機が好ましく用いられ、更にはＬ／Ｄ（スクリュー有効長さＬと外径Ｄとの比）が好ましくは３０以上、より好ましくは３６〜６０の二軸押出機が好ましく用いられる。二軸押出機としては、例えば、２本のスクリューが噛み合うもの、噛み合わないもの等任意の二軸押出機を使用することができるが、２本のスクリューの回転方向が同一方向でスクリューが噛み合うものがより好ましい。このような二軸押出機としては池貝社製ＧＴ、神戸製鋼所社製ＫＴＸ、日本製鋼所社製ＴＥＸ、東芝機械社製ＴＥＭ、ワーナー社製ＺＳＫ（いずれも商標）等が挙げられる。
【００６５】
上記連続式押出機で熱可塑性エラストマー組成物を製造する場合、上記未変性及びアクリル変性オルガノポリシロキサンの供給方法としては、粉体の場合、ミキサーを用いて架橋反応に供される樹脂・ゴム組成物と予め混合して上記連続式押出機に供給する方法があるが、液体の場合、ミキサーを用いて架橋反応に供される樹脂・ゴム組成物と予め混合して上記連続式押出機に供給する方法、又はフィードホッパーとダイとの間に設けられたバレル開口部から供給する方法等がある。
【００６６】
上記連続式押出機で熱可塑性エラストマー組成物を製造する場合、鉱物油系軟化剤（Ｂ１及びＢ２）、架橋剤及び架橋助剤の供給方法としては、ミキサーを用いて架橋反応に供される上記樹脂・ゴム組成物と予め混合して上記連続式押出機に供給する方法、又はフィードホッパーとダイとの間に設けられたバレル開口部から供給する方法等がある。
【００６７】
上記密閉式混練機としては樹脂・ゴム組成物を架橋剤の存在下で溶融混練することができるならば特に限定されず、例えば、加圧型ニーダー、バンバリーミキサー、ブラベンダーミキサー等が挙げられる。
【００６８】
上記密閉式混練機で熱可塑性エラストマー組成物を製造する場合、上記未変性及びアクリル変性オルガノポリシロキサン、上記鉱物油系軟化剤（Ｂ１及びＢ２）、架橋剤及び架橋助剤は予め上記α−オレフィン系熱可塑性樹脂（Ｃ）と混合してもよいし、予め混合することなく上記密閉式混練機中に各々供給してもよく、特に限定はされない。また、樹脂・ゴム組成物を溶融混練した後で上記未変性及びアクリル変性オルガノポリシロキサン、上記鉱物油系軟化剤（Ｂ１及びＢ２）、架橋剤及び架橋助剤を投入してもよいし、最初から樹脂・ゴム組成物と一緒に上記密閉式混練機に入れ溶融混練してもよく、手順は特に限定されない。
また、無機充填材等の添加材等を、上記密閉式混練機又は上記連続式押出機に供給することができる。
【００６９】
請求項５記載の熱可塑性エラストマー組成物の製造方法は、請求項１乃至３のいずれかに記載の樹脂・ゴム組成物を密閉式混練機を用いて溶融混練し、次いでこの溶融混練物に架橋剤を配合して連続式押出機に供給し、その後動的に熱処理することを特徴とする。
【００７０】
上記密閉式混練機及び上記連続式混練機は上記例示したものを用いることができる。
架橋剤を除いて上記樹脂・ゴム組成物を上記密閉式混練機を用いて溶融混練する場合、上記未変性及びアクリル変性オルガノポリシロキサン及び上記鉱物油系軟化剤（Ｂ１）は予め樹脂・ゴム組成物と混合してもよいし、予め混合することなく上記密閉式混練機中に各々供給してもよく、特に手順は限定はされない。また、樹脂・ゴム組成物を溶融混練した後で上記未変性オルガノポリシロキサン（Ｅ）及び（Ｆ）、上記アクリル変性オルガノシロキサン（Ｇ）及び上記鉱物油系軟化剤（Ｂ１）を投入してもよいし、最初から樹脂・ゴム組成物と一緒に上記密閉式混練機に入れ溶融混練してもよく、手順は特に限定されない。
【００７１】
上記密閉式混練機で得られた溶融混練物は、フィーダールーダーを用いてペレット状に加工してもよいし、一旦、ロールミルにてシート化したものをシートペレタイザーでペレット加工してもよい。
【００７２】
上記連続式押出機を用いて樹脂・ゴム組成物を動的架橋する場合、架橋剤、架橋助剤及び鉱物油系軟化剤（Ｂ１）の供給方法としては、ミキサーを用いて架橋反応に供される樹脂・ゴム組成物と予め混合して上記連続式押出機に供給する方法や、フィードホッパーとダイとの間に設けられたバレル開口部から供給する方法等とすることができる。
【００７３】
無機充填材等の添加剤等は、上記密閉式混練機に供給することも、上記連続式押出機に供給することもでき、更には両方の押出機に供給することもできる。
【００７４】
請求項６記載の熱可塑性エラストマー組成物の製造方法は、請求項１乃至３のいずれかに記載の樹脂・ゴム組成物に架橋剤を配合し、連結した複数台の連続式混練機に供給し、動的に熱処理することを特徴とする。
【００７５】
上記製造方法は、例えば、樹脂・ゴム組成物を連結した２台の上記連続式混練機のうちの第１連続式混練機に供給し、第１連続式押出機内で架橋剤の存在下で樹脂・ゴム組成物を混練し、実質的に動的架橋反応が進行していない段階で第２連続式押出機に供給して動的架橋を進行させ、架橋する方法である。
【００７６】
上記第１連続式押出機としては、例えば、一軸押出機、二軸押出機、二軸ローター型連続式混練機等が挙げられ、これらのうち、特に二軸ローター型連続式押出機が好ましく用いられる。上記二軸ローター型連続式押出機としては日本製鋼所社製ＣＩＭ、神戸製鋼所社製ミクストロンＦＣＭ，ＮＣＭ，ＬＣＭ，ＡＣＭ（いずれも商標）がある。
【００７７】
上記第１連続式押出機における混練物は、溶融状態で上記第２連続式押出機に供給されることが好ましく、上記第２連続式押出機に供給される際の混練物の温度は、α−オレフィン系熱可塑性樹脂の融点や架橋剤種等により異なるが、好ましくは１４０℃〜２５０℃、より好ましくは１５０℃〜２４０℃、更に好ましくは１５０℃〜２３０℃とすることができる。
【００７８】
上記第２連続式押出機としては、例えば、一軸押出機、二軸押出機、二軸ローター型押出機等が挙げられるが、これらのうち、二軸押出機が好ましく用いられ、更にはＬ／Ｄ（スクリュー有効長Ｌと外径Ｄとの比）が好ましくは３０以上、より好ましくは３６〜６０の二軸押出機が好ましく用いられる。二軸押出機としては、例えば、２本のスクリューが噛み合うもの、噛み合わないもの等任意の二軸押出機を使用することができる。２本のスクリューの回転方向が同一方向でスクリューが噛み合うものがより好ましい。このような二軸押出機としては池貝社製ＧＴ、神戸製鋼所社製ＫＴＸ、日本製鋼所社製ＴＥＸ、東芝機械社製ＴＥＭ、ワーナー社製ＺＳＫ（いずれも商標）等が挙げられる。
【００７９】
例えば２台の連続式押出機を連結した装置を用いて熱可塑性エラストマー組成部を製造する場合、上記未変性及びアクリル変性オルガノポリシロキサンの供給方法としては、（１）ミキサーを用いて架橋反応に供される樹脂・ゴム組成物と予め混合して第１連続式押出機に供給する方法、（２）第１連続式押出機及び／又は第２連続式押出機のフィードホッパーから供給する方法、（３）第１連続式押出機及び／又は第２連続式押出機のフィードホッパーとダイとの間に設けられたバレル開口部から供給する方法等が挙げられる。
【００８０】
上記鉱物油系軟化剤（Ｂ１）、無機充填材等の添加剤等は、第１連続式押出機に供給することも、第２連続式押出機に供給することもでき、更には両方の押出機に供給することもできる。
【００８１】
請求項４乃至６に示される三種の動的熱処理の条件は、特に限定されないが、α−オレフィン系熱可塑性樹脂（Ｃ）の融点、架橋剤の種類、混練形態等によって異なるが、通常、処理温度は１２０℃〜３５０℃、より好ましくは１４０℃〜３２０℃、更に好ましくは１６０℃〜３００℃とすることができる。
【００８２】
【発明の実施の形態】
以下に、実施例を挙げて本発明を更に具体的に説明するが、本発明は、その要旨を超えない限り、以下の実施例に何ら制約されるものではない。
先ず、組成物原料として用いた油展ゴム（Ｘ）、共重合ゴム、鉱物油系軟化剤（Ｂ１）、α−オレフィン系結晶性熱可塑性樹脂（ｃ１）、α−オレフィン系非晶質熱可塑性樹脂（ｃ２）、未変性オルガノポリシロキサン、アクリル変性オルガノポリシロキサンを以下に示す。
【００８３】
〔１〕油展ゴム（Ｘ）
（１）油展ゴム１：エチレン・プロピレン・５−エチリデン−２−ノルボルネン三元共重合体
エチレン含量６６質量％、５−エチリデン−２−ノルボルネン含量４．５質量％、極限粘度４．７ｄｌ／ｇ、鉱物油系軟化剤（商品名「ＰＷ−３８０」、出光興産社製）含有量５０質量％
（２）油展ゴム２：エチレン・プロピレン・５−エチリデン−２−ノルボルネン三元共重合体
エチレン含量６６質量％、５−エチリデン−２−ノルボルネン含量４．５質量％、極限粘度３．８ｄｌ／ｇ、鉱物油系軟化剤（商品名「ＰＷ−３８０」、出光興産社製）含有量４０質量％
【００８４】
〔２〕鉱物油系軟化剤（Ｂ１）：商品名「ＰＷ−３８０」、出光興産社製
〔３〕α−オレフィン系結晶性熱可塑性樹脂（ｃ１）
（１）（ｃ１１）：プロピレン・エチレンランダム共重合体
密度０．９０ｇ／ｃｍ^３、ＭＦＲ（温度２３０℃、荷重２．１６ｋｇ）２３ｇ／１０ｍｉｎ．、商品名「ノバテックＰＰ ＦＬ２５Ｒ」、日本ポリケム社製
（２）（ｃ１２）：ポリプロピレン重合体
密度０．９０ｇ／ｃｍ^３、ＭＦＲ（温度２３０℃、荷重２．１６ｋｇ）３ｇ／１０ｍｉｎ．、商品名「ノバテックＰＰ ＭＡ４」、日本ポリケム社製
〔４〕α−オレフィン系非晶質熱可塑性樹脂（ｃ２）
（１）プロピレン・1−ブテン非晶質共重合体
プロピレン含量７１モル％、溶融粘度８０００ｃｐｓ、密度０．８７９ｇ／ｃｍ^３、Ｍｎ６５００、商品名「ＡＰＡＯ ＵＴ２７８０」、宇部興産社製
【００８５】
〔５〕未変性オルガノポリシロキサン
（１）ポリジメチルシロキサン
粘度１００ｃＳｔ、商品名「シリコーンオイルＳＨ−２００」、東レ・ダウコーニング・シリコーン社製
（２）ポリジメチルシロキサン
粘度１０００ｃＳｔ、商品名「シリコーンオイルＳＨ−２００」、東レ・ダウコーニング・シリコーン社製
（３）ポリジメチルシロキサン
粘度５０００ｃＳｔ、商品名「シリコーンオイルＳＨ−２００」、東レ・ダウコーニング・シリコーン社製
【００８６】
〔６〕未変性オルガノポリシロキサン
（１）ポリジメチルシロキサン
粘度１２５００ｃＳｔ、商品名「シリコーンオイルＳＨ−２００」、東レ・ダウコーニング・シリコーン社製
（２）超高分子量シリコーンゴム
粘度１００００００ｃＳｔ以上、商品名「ＢＹ１６−１４０」、東レ・ダウコーニング・シリコーン社製
〔７〕アクリル変性オルガノポリシロキサン（Ｇ）
アクリル変性シリコーン樹脂、商品名「ｘ−２２−８１７１」、信越化学工業社製
【００８７】
また、架橋剤１として、２，５−ジメチル−２，５−ジ（ｔ−ブチルパーオキシ）ヘキサン（商品名「パーヘキサ２５Ｂ−４０」、日本油脂社製）を、架橋剤２として、Ｎ，Ｎ’−ｍ−フェニレンビスマレイミド（商品名「バルノックＰＭ」、大内新興化学社製）、架橋助剤として、ジビニルベンゼン（三共化成社製）を用いた。更に、老化添加剤として、商品名「イルガノックス１０１０」（日本チバガイギー社製）を用いた。
【００８８】
実施例１〜７、比較例１〜５（密閉式混練機＋連続式混練機による製造）
表１及び２に示す配合から架橋剤を除いたものを、１５０℃に加熱した加圧ニーダー（森山製作所社製）に投入し、各成分が均一に分散するまで４０ｒｐｍで１５分問混練した。その後、溶融状態の組成物をフィーダールーダー（森山製作所社製）にてペレット化した。得られたペレットに表１及び２に示す配合割合で架橋剤及び架橋助剤を添加し、ヘンシェルミキサーにて３０秒間混合した後、重量式フィーダーを用いて二軸押出機（同方向非噛み合い型スクリュー、Ｌ／Ｄ＝３８．５、池貝社製、品名「ＰＣＭ−４５」）に吐出量４０ｋｇ／ｈで供給し、２００℃、スクリュー回転数３００ｒｐｍ、滞留時間２分で動的熱処理を施しながら押出を行い、熱可塑性エラストマー組成物を得た。
【００８９】
【表１】

【００９０】
【表２】

【００９１】
熱可塑性エラストマー組成物の評価
上記のようにして得られた熱可塑性エラストマー組成物を評価するために下記項目の測定を行った。
〔ア〕メルトフローレート（ＭＦＲ）
２３０℃、荷重１０ｋｇで測定し、表１及び２に示した。
〔イ〕硬度、引張破断強度及び引張破断伸び
ＪＩＳ−Ｋ６３０１に準じて測定した。
〔ウ〕圧縮永久歪み
ＪＩＳ−Ｋ６３０１に準じ、７０℃、２２時間、２５％圧縮の条件で測定した。
【００９２】
〔エ〕初期摺動性及び耐久摺動性
往復摺動試験機（東測精密社製）を用いて、荷重２３３ｇ／３ｃｍ^２（面圧７８ｇ／ｃｍ^２）、ガラスリング試験片摺動速度＝１００ｍｍ／ｍｉｎ（１ストローク＝５０ｍｍ）で、外径２５．７ｍｍ、内径２０ｍｍ、高さ１６．５ｍｍ、重さ９．６ｇの円筒型ガラスリング試験片に対する、熱可塑性エラストマー組成物より作製した試験片（長さ１１０ｍｍ、幅６１ｍｍ、厚さ２ｍｍ）の静摩擦係数及び動摩擦係数を測定した。初期摺動性は、熱可塑性エラストマー組成物の試験片を射出成形後、１日経過したものを用い、室温にて測定した。また、耐久摺動性は、１００℃のギアオーブンに射出成形後から５００時間経過したものを用い、室温にて測定した。
〔オ〕ブリード試験
ギアオーブン（東洋精機社製）の中に熱可塑性エラストマー組成物より作製した試験片を入れ、１００℃、１２０時間放置し、試験片の表面状態を目視観察した。
【００９３】
〔カ〕押出加工性
ラボプラストミル押出機（東洋精機社製、外径＝２０ｍｍ、Ｌ／Ｄ＝２５）を用いて、下記条件にて平板押出（口金部幅２５ｍｍ、厚み１．５ｍｍ）を行い、その外観を目視で評価した。表面が平滑でエッジあるものは○、それ以外は全て×とした。
シリンダーＣ１＝１８０℃
シリンダーＣ２＝１９０℃
シリンダーＣ３＝２１０℃
ダイ＝２０５℃
スクリュー回転数：４０ｒｐｍ
〔キ〕射出融着性
熱可塑性エラストマー組成物を射出融着した試験片を用いて、熱可塑性エラストマー組成物と被着体との継ぎ目部を起点として、角度１８０°に折り曲げたときの剥離状態を目視にて観察し、表１及び２に併記した。
尚、表１及び２における○、△、×は、各々以下の評価基準による。
○；剥離せず
△；一部剥離
×；剥離して破断に到る
【００９４】
尚、上記〔イ〕〜〔オ〕については、以下の方法で試験片を作製した。即ち、上記のようにして得られた熱可塑性エラストマー組成物を、射出成形機（型式「Ｎ−１００」、日本製鋼所社製）により１２０×１２０×２ｍｍの大きさに射出成形した試験片を作製した。
【００９５】
また、上記〔キ〕については、以下のようにオレフィン系加硫ゴムからなる被着体を作製し、試験に供した。
エチレン・プロピレン・５−エチリデン−２−ノルボルネン三元共重合体（エチレン含量７２モル％、プロピレン含量２８モル％、ムーニー粘度９２、よう素価１５、商品名「ＥＰ １０３Ａ」、ＪＳＲ社製）１００質量部に対して、カーボンブラック（商品名「シースト１１６」、東海カーボン社製）１４５質量部、パラフィン系プロセスオイル（商品名「ＰＷ−３８０」、出光興産社製）８５質量部、活性亜鉛華（堺化学工業社製）５質量部、ステアリン酸（旭電化工業社製）１質量部、加工助剤（商品名「ヒタノール１５０１」、日立化成工業社製）１質量部、離型剤（商品名「ストラクトールＷＢ２１２」、シル・アンド・ザイラハー社製）２質量部、可塑剤（ポリエチレングリコール）１質量部を配合した混合物を得た。
この混合物をバンバリーミキサーを用いて、５０℃、７０ｒｐｍ、混練時間２．５分の条件で混練した。次いで、脱水剤（商品名「ベスタＰＰ」、井上石灰工業社製）１０質量部、加硫促進剤（商品名「Ｍ」１質量部、商品名「ＰＸ」１質量部、商品名「ＴＴ」０．５質量部、商品名「Ｄ」１質量部、すべて大内新興化学工業社製）、硫黄２．２質量部を添加して、オープンロールを用いて５０℃で混練した。その後、１７０℃で１０分間加硫して、１２０ｍｍ四方、厚さ２ｍｍの加硫ゴムシートを得た。このシートを、ダンベルカッターで長さ６０ｍｍ、幅５０ｍｍに打ち抜いて被着体を得た。
以上
【００９６】
実施例の効果
比較例１乃至３は、低粘度の未変性オルガノポリシロキサンのみを用い、またアクリル変性オルガノポリシロキサンを含まない例であり、押出加工性及び射出融着性に優れるが、初期及び耐久における摺動性に劣っており、ブリードが確認された。比較例４は高粘度の未変性オルガノポリシロキサンのみを用い、またアクリル変性オルガノポリシロキサンを含まない例であり、押出加工性及び射出融着性に優れるが、初期及び耐久における摺動性に劣っていた。比較例５は低粘度及び高粘度の未変性オルガノポリシロキサンを含むが、アクリル変性オルガノポリシロキサンを含まない例であり、初期及び耐久における摺動性、押出加工性、射出融着性、に劣っており、ブリードも確認された。
一方、実施例１乃至７の熱可塑性エラストマー組成物は、初期及び耐久における摺動性と押出加工性に優れ、オルガノポリシロキサンのブリードも見られない。また、射出融着性についても剥離、破断等は見られず、優れた射出融着性を有することが分かる。
【００９７】
【発明の効果】
本発明によれば、射出成形、押出成形、中空成形、圧縮成形、真空成形、積層成形、カレンダー成形等により加工が容易な熱可塑性エラストマー組成物を得ることができる。また、押出性、摺動性、加硫ゴムに対する射出融着性、更には成形外観及び触感に優れた熱可塑性エラストマー組成物を得ることができる。特に、摺動性については初期のみでなく長期にわたって優れた性質を示す。[0001]
[Technical field to which the invention belongs]
The present invention relates to a thermoplastic elastomer composition and a method for producing the same, and more particularly, is excellent in initial slidability, durable slidability, abrasion resistance, heat sealability and moldability, and has a molded appearance of a molded article. The present invention also relates to a thermoplastic elastomer composition having a good feel and a method for producing the same.
[0002]
[Prior art]
Thermoplastic elastomers obtained by dynamically cross-linking ethylene copolymer rubber and olefin resin in the presence of a cross-linking agent are flexible, have excellent rubber properties, and do not require a vulcanization step. For this reason, a molded article can be obtained by a usual thermoplastic resin molding method such as injection molding, profile extrusion molding, calendering, and blow molding. Therefore, in recent years, from the viewpoints of energy saving, resource saving, and recycling, demand has been increasing as a substitute material for vulcanized rubber and vinyl chloride resin in automobile parts, industrial supplies, electric and electronic parts, building materials, and the like. However, automotive parts such as glass run channels and wind moldings have many problems such as poor sliding properties against window glass and poor durability.
[0003]
In order to improve the slidability, Japanese Patent Application Laid-Open No. 2000-26668 discloses an olefin-based thermoplastic elastomer composition in which an organopolysiloxane and an aliphatic amide are added to an olefin-based thermoplastic elastomer. Japanese Patent Application Laid-Open Publication No. H11-163,086 discloses an olefin-based thermoplastic elastomer composition in which an olefin-based thermoplastic elastomer is used in combination with an acrylic-modified organopolysilixane and a higher fatty acid and / or a higher fatty acid amide. In addition, there is a problem that the fatty acid amide bleeds out and causes poor appearance. Further, in Japanese Patent Application Laid-Open No. 2000-959000, an olefin-based thermoplastic elastomer has a viscosity of 10 to 10 ⁶ Organopolysiloxane of less than cSt, viscosity 10 ⁶ -10 ⁸ An olefin-based thermoplastic elastomer composition in which a cSt organopolysiloxane and a fluoropolymer are added in combination has been disclosed. However, since a large amount of the organopolysiloxane is blended, the slidability is good. There is a problem that bleed-out occurs due to poor compatibility with the plastic elastomer, and there is a slimy feeling when touching the surface, which is not preferable.
[0004]
[Problems to be solved by the invention]
The present invention has been made in view of the above circumstances, and has excellent initial slidability, durable slidability, abrasion resistance, heat sealability and moldability, and has a good molded appearance and tactile sensation of molded articles. It is an object of the present invention to provide a thermoplastic elastomer composition and a method for producing the same.
[0005]
[Means for Solving the Problems]
The thermoplastic elastomer composition according to claim 1, comprising 20 to 69 parts by mass of an ethylene / α-olefin-based copolymer rubber (A), 20 to 79 parts by mass of a mineral oil-based softener (B1), and an α-olefin-based copolymer. A base polymer comprising 1 to 50 parts by mass of an α-olefin-based thermoplastic resin (C) composed of a crystalline thermoplastic resin (c1) and / or an α-olefin-based amorphous thermoplastic resin (c2). When D1) is 100 parts by mass, 1 to 10 parts by mass of an unmodified organopolysiloxane (E1) having a viscosity at 25 ° C. of less than 10,000 cSt specified by JIS K2283, and an unmodified organopolysiloxane having a viscosity of 10,000 cSt or more. 1 to 10 parts by mass of siloxane (F1); acrylic A resin / rubber composition (H1) containing 0.2 to 20 parts by mass of a modified organopolysiloxane (G) is dynamically heat-treated in the presence of a crosslinking agent.
[0006]
The “ethylene / α-olefin-based copolymer rubber (A)” (hereinafter also simply referred to as “copolymer rubber (A)”) is a copolymer containing ethylene and an α-olefin other than ethylene as main constituent units. It is rubber. When the total amount of the copolymer rubber is 100 mol%, it is preferable to contain 90 mol% or more of ethylene and α-olefin.
[0007]
As the α-olefin constituting the copolymer rubber (A), propene (hereinafter referred to as “propylene”), 1-butene, 1-pentene, 3-methyl-1-butene, 1-hexene, 3-methyl- Α-olefins having 3 to 12 carbon atoms, such as 1-pentene, 4-methyl-1-pentene, 3-ethyl-1-pentene, 1-octene, 1-decene, and 1-undecene, may be used alone. Alternatively, two or more kinds can be used as a mixture. Of these, propylene and / or 1-butene are preferably used.
[0008]
Furthermore, non-conjugated dienes can be used as other constituent units. Examples of the non-conjugated diene include 1,4-pentadiene, 1,4-hexadiene, 1,5-hexadiene, 1,7-octadiene, 1,9-decadiene, 3,6-dimethyl-1,7-octadiene, , 5-dimethyl-1,7-octadiene, 5-methyl-1,8-nonadiene, dicyclopentadiene, 5-ethylidene-2-norbornene, 5-vinyl-2-norbornene, 2,5-norbornadiene and the like. In particular, dicyclopentadiene and / or 5-ethylidene-2-norbornene are preferably used.
[0009]
That is, as the copolymer rubber (A), ethylene ・ α-olefin binary copolymer, ethylene ・ α-olefin ・ Non-conjugated diene terpolymers and the like are preferably used.
Above ethylene ・ As the α-olefin binary copolymer, ethylene ・ Propylene binary copolymer (hereinafter simply referred to as “EPM”) and ethylene ・ A 1-butene binary copolymer (hereinafter, simply referred to as “EBM”) is particularly preferably used. Further, the ethylene content of the EPM and the EBM is preferably 50 to 95 mol% (more preferably 60 to 90 mol%) when the whole binary copolymer is 100 mol%.
[0010]
In addition, the ethylene ・ α-olefin ・ Non-conjugated diene terpolymers include ethylene ・ propylene ・ Dicyclopentadiene terpolymer, ethylene ・ propylene ・ 5-ethylidene-2-norbornene terpolymer, ethylene ・ 1-butene ・ Dicyclopentadiene terpolymer and ethylene ・ 1-butene ・ A 5-ethylidene-2-norbornene terpolymer is particularly preferably used. The ethylene content in the terpolymer may be 50 to 95 mol% (more preferably 60 to 90 mol%) when the total of ethylene units and propylene or 1-butene units is 100 mol%. preferable. Furthermore, the content of dicyclopentadiene or 5-ethylidene-2-norbornene is 3 to 10 mol% (more preferably 3 to 8 mol) when the total of ethylene units and propylene or 1-butene units is 100 mol%. %).
[0011]
If the ethylene content of the binary copolymer and the ternary copolymer is less than 50 mol%, the crosslinking efficiency tends to decrease (particularly when an organic peroxide is used as a crosslinking agent), and the It becomes difficult to obtain desired physical properties. On the other hand, if the ethylene content exceeds 95 mol%, the flexibility of the copolymer rubber (A) tends to decrease, which is not preferable.
[0012]
In the present invention, as the copolymer rubber (A), in addition to the above-mentioned binary copolymer and the above-mentioned terpolymer, some of the hydrogen atoms contained in these polymers may be halogen atoms such as chlorine atoms and bromine atoms. Halogenated copolymers substituted with atoms, vinyl chloride, vinyl acetate, (meth) acrylic acid, derivatives of (meth) acrylic acid [methyl (meth) acrylate, glycidyl (meth) acrylate, (meth) Acrylamide, etc.], maleic acid, maleic acid derivatives (maleic anhydride, maleimide, dimethyl maleate, etc.), conjugated dienes (butadiene, isoprene, chloroprene, etc.) and the like. A graft copolymer obtained by graft-polymerizing a copolymer, a halogenated copolymer, or the like can also be used. These copolymers can be used alone or in combination of two or more.
[0013]
Further, as described in claim 3, the copolymer rubber (A) has an intrinsic viscosity [η] of 3.5 to 6.8 dl / g (more preferably, 4.35 dl / g) as measured in a decalin solvent at 135 ° C. 3 to 6.0 dl / g). If the intrinsic viscosity is less than 3.5 dl / g, the elastic recovery tends to decrease, while if it exceeds 6.8 dl / g, the processability during molding tends to decrease, which is not preferable. Further, the crystallinity of the copolymer rubber (A) by X-ray diffraction measurement is preferably 20% or less (more preferably 15% or less). If the crystallinity exceeds 20%, the flexibility of the copolymer rubber tends to decrease, which is not preferable.
The copolymer rubber (A) is ethylene. ・ α-olefin ・ In the case of a non-conjugated diene terpolymer, the iodine value is preferably 5 to 30 (more preferably 7 to 20).
[0014]
The copolymer rubber (A) requires, for example, ethylene, α-olefin and non-conjugated diene in the presence of a catalyst comprising a solvent containing a Ziegler-Natta catalyst, a soluble vanadium compound, and an organoaluminum compound. Accordingly, it can be obtained by a polymerization method using a medium / low pressure method such as a method of performing polymerization while supplying hydrogen as a molecular weight regulator. The polymerization can be carried out by a gas phase method (fluidized bed or stirred bed) or a liquid phase method (slurry method or solution method).
[0015]
Examples of the soluble vanadium compound include VOCl ₃ And VCl ₄ It is preferable to use a reaction product of at least one of the above and an alcohol. As the alcohol, methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, t-butanol, n-hexanol, n-octanol, 2-ethylhexanol, n-decanol, n-dodecanol, or the like is used. Of these, alcohols having 3 to 8 carbon atoms are preferably used.
[0016]
Examples of the organic aluminum compound include, for example, triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, diethylaluminum monochloride, diisobutylaluminum monochloride, ethylaluminum sesquichloride, butylaluminum sesquichloride, ethylaluminum dichloride, butyl Examples include aluminum dichloride, methylaluminoxane, which is a reaction product of trimethylaluminum and water, and the like. Of these, ethyl aluminum sesquichloride, butyl aluminum sesquichloride, a mixture of ethyl aluminum sesquichloride and triisobutyl aluminum, and a mixture of triisobutyl aluminum and butyl aluminum sesquichloride are particularly preferably used.
Further, as the solvent, hydrocarbons are preferably used, and among these, n-pentane, n-hexane, n-heptane, n-octane, isooctane and cyclohexane are particularly preferably used. These can be used alone or in combination of two or more.
[0017]
The copolymer rubber (A) includes vegetable oil (such as coconut oil), esters of fatty acids and higher alcohols (such as phthalic diesters), phosphoric acid triesters, and mineral oil (such as paraffinic mineral oil, (Naphthenic mineral oil, aromatic mineral oil) and the like.
[0018]
The “mineral oil-based softener (B1)” is not particularly limited, but includes naphthenic oil, paraffin oil, aromatic mineral oil, and the like, and naphthenic oil and / or paraffin oil are particularly preferably used.
[0019]
Among the α-olefin-based thermoplastic resins (C), the “α-olefin-based crystalline thermoplastic resin (c1)” (hereinafter, also simply referred to as “crystalline polymer (c1)”) is an α-olefin. As a main component. That is, when the entire crystalline polymer (c1) is 100% by mass, the α-olefin preferably contains 80% by mass or more (more preferably 90% by mass or more).
The crystalline polymer (c1) may be a homopolymer of α-olefin, a copolymer of two or more α-olefins, or a copolymer with a monomer other than α-olefin. It may be. Also, a mixture of two or more of these different polymers and / or copolymers may be used.
[0020]
As the α-olefin constituting the crystalline polymer (c1), an α-olefin having 3 or more carbon atoms is preferably used, and an α-olefin having 3 to 12 carbon atoms as in the above copolymer rubber is used. Is more preferable. In the case of a copolymer with ethylene, the ethylene content is preferably 40 mol% or less (more preferably, 20 mol% or less) when the whole copolymer is 100 mol%.
[0021]
When the polymer constituting the crystalline polymer (c1) is a copolymer, the copolymer may be any of a random copolymer and a block copolymer. However, in order to obtain the following crystallinity, the total content of the structural units in the random copolymer excluding the α-olefin is 15 mol% or less (more preferably 10 mol% or less) when the whole random copolymer is 100 mol%. Mol% or less). Further, in the block copolymer, the total content of the constituent units excluding the α-olefin is preferably 40 mol% or less (more preferably 20 mol% or less) when the whole block copolymer is 100 mol%. .
In addition, such a random copolymer can be obtained, for example, by the same method as that for the copolymer rubber (A). Further, such a block copolymer can be obtained by living polymerization using a Ziegler-Natta catalyst.
[0022]
Further, the crystalline polymer (c1) has crystallinity. This crystallinity is preferably 50% or more (more preferably 53% or more, further preferably 55% or more) in crystallinity by X-ray diffraction measurement. This crystallinity is closely related to the density. For example, in the case of polypropylene, the density of α-type crystal (monoclinic) is 0.936 g / cm ³ , The density of smetica-type microcrystals (quasi-hexagonal) is 0.886 g / cm ³ The density of the amorphous (atactic) component is 0.850 g / cm ³ It is. Further, in the case of poly-1-butene, the density of the isotactic crystal is 0.91 g / cm. ³ The density of the amorphous (atactic) component is 0.87 g / cm ³ It is. Therefore, to obtain a crystalline polymer (c1) having a crystallinity of 50% or more, the density is 0.89 g / cm. ³ Or more (more preferably 0.90 to 0.94 g / cm ³ ) Is preferable. This crystallinity is less than 50% and the density is 0.89 g / cm ³ If it is less than 3, heat resistance, strength, and the like tend to decrease.
[0023]
Further, the maximum peak temperature of the crystalline polymer (c1) by the differential scanning calorimetry, that is, the melting point (hereinafter simply referred to as “T _m ) Is preferably 100 ° C or higher (more preferably 120 ° C or higher). T _m If it is lower than 100 ° C., sufficient heat resistance and strength tend not to be exhibited. Also, T _m It is preferably 120 ° C. or higher, though it depends on the monomer constituting it.
The melt flow rate (at a temperature of 230 ° C. and a load of 2.16 kg) (hereinafter simply referred to as “MFR”) is 0.1 to 100 g / 10 min (more preferably 0.5 to 80 g / 10 min). Is preferred. When the MFR is less than 0.1 g / 10 minutes, the kneading processability, extrusion processability, and the like of the elastomer composition tend to be insufficient. On the other hand, if it exceeds 100 g / 10 minutes, the strength tends to decrease.
[0024]
Therefore, the crystalline polymer (c1) has a crystallinity of 50% or more and a density of 0.89 g / cm. ³ And the content of ethylene units is 20 mol% or less, _m Is 100 ° C. or more, MFR is 0.1 to 100 g / 10 min, and melting point is 140 to 170 ° C. It is particularly preferable to use a copolymer of polypropylene and / or propylene with ethylene.
[0025]
Among the α-olefin-based thermoplastic resins (C), the “α-olefin-based amorphous thermoplastic resin” (hereinafter, also simply referred to as “amorphous polymer (c2)”) is an α-olefin. As a main component. That is, when the entire amorphous polymer (c2) is 100 mol%, the α-olefin preferably contains 50 mol% or more (more preferably 60 mol% or more).
The amorphous polymer (c2) may be a homopolymer of an α-olefin, a copolymer of two or more α-olefins, or a copolymer with a monomer that is not an α-olefin. It may be united. Also, a mixture of two or more of these different polymers and / or copolymers may be used.
As the α-olefin constituting the amorphous polymer (c2), an α-olefin having 3 or more carbon atoms is preferably used, and the α-olefin having 3 to 12 carbon atoms as exemplified in the copolymer rubber (A) is preferably used. More preferably, an α-olefin is used.
[0026]
Examples of the amorphous polymer (c2) include homopolymers such as atactic polypropylene and atactic poly-1-butene, and propylene (containing 50 mol% or more) and other α-olefins (ethylene, 1-butene). , 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, etc.), 1-butene (containing at least 50 mol%) and other α-olefins (ethylene Propylene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, etc.).
[0027]
When the polymer constituting the amorphous polymer (c2) is a copolymer, the copolymer may be any of a random copolymer and a block copolymer. However, in the case of a block copolymer, the α-olefin units (propylene and 1-butene in the above-mentioned copolymer) which are the main components need to be bonded in an atactic structure. When the amorphous copolymer (c2) is a copolymer of an α-olefin having 3 or more carbon atoms and ethylene, the content of the α-olefin is preferably 50 when the whole copolymer is 100 mol%. Mol% or more (more preferably 60 to 100 mol%).
[0028]
Examples of the amorphous polymer (c2) include atactic polypropylene (propylene content of 50 mol% or more), a copolymer of propylene (containing 50 mol% or more) and ethylene, and a copolymer of propylene and 1-butene. It is particularly preferred to use
The atactic polypropylene can be obtained as a by-product of polypropylene that can be used as the crystalline polymer (c1). Further, atactic polypropylene and atactic poly-1-butene can also be obtained by polymerization using a zirconocene compound-methylaluminoxane catalyst. Further, the random copolymer can be obtained by a method similar to that for the copolymer rubber (A). Further, the above block copolymer can be obtained by living polymerization using a Ziegler-Natta catalyst.
[0029]
The amorphous polymer (c2) has a melt viscosity at 190 ° C. of 50,000 cps or less (more preferably 100 to 30,000 cps, further preferably 200 to 20,000 cps). If the viscosity exceeds 50,000 cps, the adhesive strength to the adherend tends to decrease. Further, the crystallinity by X-ray diffraction measurement is preferably less than 50% (more preferably 30% or less, further preferably 20% or less).
This degree of crystallinity is closely related to the density as described above, and is 0.85 to 0.89 g / cm. ³ (More preferably 0.85 to 0.88 g / cm ³ ) Is preferable. Further, the number average molecular weight M of this amorphous polymer (c2) _n Is preferably 1000 to 20,000 (more preferably 1500 to 15000).
When the melt viscosity exceeds 50,000 cps, when the crystallinity exceeds 50%, the density is 0.89 g / cm. ³ When the value exceeds the above, when the thermoplastic elastomer composition finally obtained is injection-fused with a vulcanized rubber or a thermoplastic elastomer, the adhesive strength to an adherend tends to decrease.
[0030]
As the α-olefin-based thermoplastic resin (C), both the α-olefin-based crystalline thermoplastic resin (c1) and the α-olefin-based amorphous thermoplastic resin (c2) may be used. Only one may be used.
[0031]
The base polymer (D1) according to the thermoplastic elastomer composition according to claim 1, comprises the copolymer rubber (A), the mineral oil-based softener (B1), and the α-olefin-based thermoplastic resin (C). contains. When the total of these is 100 parts by mass, the copolymer rubber (A) is 20 to 69 parts by mass (preferably 23 to 65 parts by mass, more preferably 25 to 60 parts by mass), and the mineral oil-based softener ( B1) is 20 to 79 parts by mass (preferably 25 to 75 parts by mass, more preferably 25 to 70 parts by mass), and the α-olefin-based thermoplastic resin (C) is 1 to 50 parts by mass (preferably 2 to 45 parts by mass). Parts by mass, more preferably 5 to 40 parts by mass).
[0032]
If the amount of the copolymer rubber (A) is less than 20 parts by mass, the flexibility of the obtained thermoplastic elastomer tends to decrease. On the other hand, when the blending amount of the copolymer rubber (A) exceeds 69 parts by mass, the fluidity of the thermoplastic elastomer composition obtained by heat treatment in the presence of the crosslinking agent decreases, and the moldability decreases significantly. I do. When the amount of the mineral oil-based softener (B1) is less than 20 parts by mass, the fluidity of the obtained thermoplastic elastomer tends to decrease. On the other hand, when the blending amount of the mineral oil-based softener (B1) exceeds 79 parts by mass, poor dispersion of the ethylene / α-olefin-based copolymer rubber and the α-olefin-based thermoplastic resin (C) occurs in the kneader. In addition, the rubber elasticity of the finally obtained thermoplastic elastomer composition of the present invention deteriorates.
[0033]
When the blending amount of the α-olefin-based thermoplastic resin (C) is less than 1 part by mass, the phase structure (morphology) of the finally obtained thermoplastic elastomer composition is good when heat-treated in the presence of a crosslinking agent. A sea-island structure (α-olefin-based thermoplastic resin does not form a sea (matrix), cross-linked rubber forms an island (domain)), and molding processability and mechanical properties deteriorate. On the other hand, when the blending amount of the α-olefin-based thermoplastic resin (C) exceeds 50 parts by mass, the flexibility and rubber elasticity of the obtained thermoplastic elastomer are undesirably reduced. The α-olefin-based crystalline thermoplastic resin (c1) and the α-olefin-based amorphous thermoplastic resin (c2) may be used either alone or as a mixture of both.
[0034]
In claim 1, the unmodified organopolysiloxane represented by (E1) and (F1) is not particularly limited. Examples of the unmodified organopolysiloxane include dimethylpolysiloxane, methylphenylpolysiloxane, fluoropolysiloxane, tetramethyltetraphenylpolysiloxane, methylhydrogenpolysiloxane, etc., of which dimethylpolysiloxane is preferred. Used. The unmodified organopolysiloxane (E1) and the unmodified organopolysiloxane (F1) may be the same compound or a combination of different ones.
[0035]
The unmodified organopolysiloxane (E1) has a viscosity at 25 ° C. specified by JIS K2283 of less than 10,000 cSt, preferably less than 7000 cSt, more preferably less than 5000 cSt.
The amount of the unmodified organopolysiloxane (E1) is 1 to 10 parts by mass, preferably 1 to 8 parts by mass, more preferably 1 to 10 parts by mass, based on 100 parts by mass of the base polymer (D1) of the thermoplastic elastomer composition. 1 to 5 parts by mass. When the unmodified organopolysiloxane (E1) having a viscosity of less than 10,000 cSt at 25 ° C. specified by JIS K2283 is used alone, the unmodified organopolysiloxane causes bleed-out.
[0036]
The unmodified organopolysiloxane (F1) has a viscosity at 25 ° C. specified by JIS K2283 of 10,000 cSt or more, preferably 10,000 to 1,000,000 cSt, more preferably 10,000 to 100,000 cSt.
The compounding amount of the unmodified organopolysilixane (F1) is 1 to 10 parts by mass, preferably 1 to 8 parts by mass, based on 100 parts by mass of the base polymer (D1). In addition, when the unmodified organopolysiloxane (F1) having a viscosity of 10,000 cSt or more at 25 ° C. specified in JIS K2283 is used alone, the slidability tends to be insufficient, which is not preferable.
[0037]
The slidability is remarkably improved by using the unmodified organopolysiloxane (E1) having a viscosity at 25 ° C. of less than 10,000 cSt defined by JIS K2283 and the unmodified organopolysiloxane (F1) having a viscosity of 10,000 cSt or more in combination. As a combination of these compounding amounts, preferably the above (E1) is 1 to 10 parts by mass, the above (F1) is 1 to 10 parts by mass, more preferably the above (E1) is 1 to 5 parts by mass, the above (F1) ) Is 1 to 5 parts by mass.
[0038]
In claim 1, the above acrylic As the modified organopolysiloxane (G), It is preferable that an organopolysiloxane is graft-polymerized with a mixture of an acrylate or a monomer copolymerizable with acrylic acid. In addition, as the modified organopolysiloxane, There is no particular limitation as long as the organopolysiloxane is chemically modified with a functional group.Examples include acrylic modification, epoxy modification, alkyl modification, amino modification, carboxyl modification, alcohol modification, fluorine modification, alkyl aral polyether modification, Epoxy polyether modification and the like.
[0039]
Examples of the acrylate which can be graft-polymerized to the organopolysiloxane include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, hexyl acrylate, pentyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, acrylic Lauryl acrylate, alkyl acrylates such as stearyl acrylate, methoxyethyl acrylate, alkoxyalkyl acrylates such as butoxyethyl acrylate, cyclohexyl acrylate, phenyl acrylate, benzyl acrylate, and the like. These may be used alone. Alternatively, two or more kinds can be used in combination.
Examples of the monomer copolymerizable with the acrylate ester include hydroxyl group-containing unsaturated monomers such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate. . These can be used alone or in combination of two or more.
[0040]
In the graft polymerization, the polymerization ratio of the organopolysiloxane and the acrylate or the monomer copolymerizable with the acrylate is preferably a mass ratio of [organopolysiloxane / copolymerizable with the acrylate or acrylate. Monomer] = 9/1 to 1/9, more preferably 8/2 to 2/8. Examples of the acryl-modified organopolysiloxane include "X-22-8171" (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.) and "Charine R-2" (trade name, manufactured by Nissin Chemical Industry Co., Ltd.).
[0041]
the above acrylic The content of the modified organopolysiloxane (G) is 0.2 to 20 parts by mass, preferably 0.5 to 15 parts by mass, more preferably 1 to 100 parts by mass based on 100 parts by mass of the base polymer (D1). To 10 parts by mass. this acrylic The modified organopolysiloxane functions as a compatibilizer between the base polymer (D1) of the thermoplastic elastomer composition and the unmodified organopolysiloxanes (E1) and (F1), rather than the effect of imparting slidability. Therefore, acrylic If the blending amount of the modified organopolysiloxane (G) is less than 0.2 parts by mass, the compatibilization does not work well, and the unmodified organopolysiloxanes (E1) and (F1) and the base polymer (D1) are mixed in a kneader. And the molding processability such as extrusion molding and injection molding tends to deteriorate. On the other hand, if it exceeds 20 parts by mass, the flexibility and physical properties tend to decrease.
[0042]
The thermoplastic elastomer composition according to the first aspect is obtained by dynamically heat-treating the resin / rubber composition (H1) containing the above (A) to (G) in the presence of a crosslinking agent. The crosslinking agent used here is not particularly limited, but is not particularly limited as long as it can crosslink the copolymer rubber (A) by dynamic heat treatment.
Examples of the crosslinking agent include an organic peroxide, a phenolic crosslinking agent, sulfur, a sulfur compound, p-quinone, a derivative of p-quinonedioxime, a bismaleimide compound, an epoxy compound, a silane compound, and an amino resin. In particular, organic peroxides and phenolic crosslinking agents are preferably used.
[0043]
Examples of the organic peroxide include 1,3-bis (t-butylperoxyisopropyl) benzene, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexyne-3, and 2,5-dimethyl. -2,5-bis (t-butylperoxy) hexene-3, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane, 2,2'-bis (t-butylperoxy) -P-isopropylbenzene, dicumyl peroxide, di-t-butyl peroxide, t-butyl peroxide, p-menthamperoxide, 1,1-bis (t-butylperoxy) -3,3,5- Trimethylcyclohexane, dilauroyl peroxide, diacetyl peroxide, t-butylperoxybenzoate, 2,4-dichlorobenzoyl peroxide, p-chlorobenzoy Luperoxide, benzoyl peroxide, di (t-butylperoxy) perbenzoate, n-butyl-4,4-bis (t-butylperoxy) valerate, t-butylperoxyisopropyl carbonate, and the like. Of these, 1,3-bis (t-butylperoxyisopropyl) benzene, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3, 2,5-dimethyl-2,5 Those having a relatively high decomposition temperature, such as -di (t-butylperoxy) hexane, are preferably used. These organic peroxides can be used alone or in combination of two or more.
[0044]
Furthermore, when an organic peroxide is used as a crosslinking agent, the crosslinking reaction can be gently performed by using the crosslinking agent together with a crosslinking assistant, and particularly uniform crosslinking can be formed. Examples of the crosslinking assistant include sulfur or sulfur compounds (powder sulfur, colloidal sulfur, precipitated sulfur, insoluble sulfur, surface-treated sulfur, dipentamethylenethiuram tetrasulfide, etc.), oxime compounds (p-quinone oxime, p, p′-). Dibenzoylquinone oxime), polyfunctional monomers (ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di ( (Meth) acrylate, trimethylolpropane tri (meth) acrylate, diallyl phthalate, tetraallyloxyethane, triallyl cyanurate, N, N'-m-phenylenebismaleimide, N, N'-toluylenebismaleimide, anhydrous Maleic acid, divinylbenzene, di (meth) zinc acrylate and the like) and the like. Among these, p, p'-dibenzoylquinone oxime, N, N'-m-phenylenebismaleimide and divinylbenzene are particularly preferably used. These crosslinking assistants can be used alone or in combination of two or more. In addition, among the crosslinking assistants, N, N'-m-phenylenebismaleimide has an action as a crosslinking agent, and thus can be used as a crosslinking agent.
[0045]
When an organic peroxide is used as the crosslinking agent, the amount is preferably 0.05 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, based on 100 parts by mass of the base polymer (D1). It can be. If the amount of the organic peroxide is less than 0.05 parts by mass, the degree of crosslinking is insufficient, and the rubber elasticity and mechanical strength of the finally obtained thermoplastic elastomer composition may be reduced. On the other hand, if it exceeds 10 parts by mass, the degree of crosslinking becomes excessively high, and the moldability tends to deteriorate, and the mechanical properties tend to decrease.
When an organic peroxide is used as the crosslinking agent, the amount of the crosslinking aid used is preferably 10 parts by mass or less, more preferably 0.2 to 5 parts by mass, based on 100 parts by mass of the base polymer (D1). Part. When the use amount of the crosslinking aid exceeds 10 parts by mass, the degree of crosslinking becomes excessively high, and the moldability tends to deteriorate, and the mechanical properties tend to decrease.
[0046]
Examples of the phenolic crosslinking agent among the crosslinking agents include, for example, a p-substituted phenolic compound represented by the following general formula (I), an o-substituted phenol-aldehyde condensate, an m-substituted phenol-aldehyde condensate, bromine Alkylated phenol-aldehyde condensates and the like, and particularly preferred are p-substituted phenol compounds.
[0047]
Embedded image

[0048]
Note that n is an integer of 0 to 10, X is at least one of a hydroxyl group, a halogenated alkyl group and a halogen atom, and R is a saturated hydrocarbon group having 1 to 15 carbon atoms.
[0049]
Incidentally, the p-substituted phenol compound is obtained by a condensation reaction between the p-substituted phenol and an aldehyde (preferably formaldehyde) in the presence of an alkali catalyst.
When a phenolic crosslinking agent is used as the crosslinking agent, it can be preferably 0.2 to 10 parts by mass, more preferably 0.5 to 5 parts by mass, based on 100 parts by mass of the base polymer (D1). . When the use amount of the phenolic crosslinking agent is less than 0.2 parts by mass, the adhesiveness at the time of injection fusion and the elastic recovery of the molded product obtained by injection fusion tend to decrease. On the other hand, if it exceeds 10 parts by mass, the extrusion processability and the injection processability of the thermoplastic elastomer composition tend to decrease.
[0050]
These phenolic crosslinking agents can be used alone, but a crosslinking accelerator can be used in combination to adjust the crosslinking speed. Examples of the crosslinking accelerator include metal halides (such as stannous chloride and ferric chloride) and organic halides (such as chlorinated polypropylene, bromobromide rubber, and chloroprene rubber).
It is more desirable to use a metal oxide such as zinc oxide or a dispersant such as stearic acid in addition to the crosslinking accelerator.
[0051]
The thermoplastic elastomer composition according to claim 2 comprises 30 to 70% by mass of an ethylene / α-olefin-based copolymer rubber (A) and 30 to 70% by mass of a mineral oil-based softener (B2) (provided that (A) + (B2) = 100% by mass], 30 to 99 parts by mass of an oil-extended rubber (X), 0 to 50 parts by mass of a mineral oil-based softener (B1), and an α-olefin-based crystalline thermoplastic resin (c1) And / or 1 to 50 parts by mass of an α-olefin-based thermoplastic resin (C) composed of an α-olefin-based amorphous thermoplastic resin (c2), and 100 parts by mass of the base polymer (D2). In this case, 1 to 10 parts by mass of an unmodified organopolysiloxane (E1) having a viscosity at 25 ° C. of less than 10,000 cSt defined by JIS K2283, and an unmodified organopolysiloxane having a viscosity of 10,000 cSt or more F1) and 1 to 10 parts by weight, acrylic A resin / rubber composition (H2) obtained by mixing 0.2 to 20 parts by mass of the modified organopolysiloxane (G) is dynamically heat-treated in the presence of a crosslinking agent.
[0052]
The oil-extended rubber (X) comprises the copolymer rubber (A) and the mineral oil-based softener (B2). The combination of the copolymer rubber (A) and the mineral oil-based softener (B2) constituting the oil-extended rubber (X) is preferably a combination of 35 to 65% by mass of the component (A), (B2) is 35 to 65% by mass, more preferably the component (A) is 40 to 60% by mass, and the component (B2) is 40 to 60% by mass. If the compounding amount of the component (A) is less than 30% by mass or the compounding amount of the component (B2) exceeds 70% by mass, the softener may bleed out from the finally obtained thermoplastic elastomer composition. , Mechanical properties and rubber elasticity tend to decrease. On the other hand, when the amount of the component (A) is more than 70% by mass or the amount of the component (B2) is less than 30% by mass, the moldability of the finally obtained thermoplastic elastomer composition tends to decrease. It is in. In addition, as the ethylene / α-olefin-based copolymer rubber (A) and the mineral oil-based softener (B2), those exemplified above can be used.
[0053]
As described in claim 3, the copolymer rubber (A) has an intrinsic viscosity [η] of 3.5 to 6.8 dl / g (more preferably 4.3 to 6.8 dl / g) when measured in a decalin solvent at 135 ° C. 6.0 dl / g). If the intrinsic viscosity is less than 3.5 dl / g, the elastic recovery tends to decrease, while if it exceeds 6.8 dl / g, the processability during molding tends to decrease, which is not preferable. Further, the crystallinity of the copolymer rubber (A) by X-ray diffraction measurement is preferably 20% or less (more preferably 15% or less). If the crystallinity exceeds 20%, the flexibility of the copolymer rubber tends to decrease, which is not preferable.
The copolymer rubber (A) is ethylene. ・ α-olefin ・ In the case of a non-conjugated diene terpolymer, the iodine value is preferably 5 to 30 (more preferably 7 to 20).
[0054]
The base polymer (D2) according to the thermoplastic elastomer composition according to claim 2 is the oil-extended rubber (X), if necessary, a mineral oil-based softener (B1), and the α-olefin-based thermoplastic resin (B). C). When the total is 100 parts by mass, the oil-extended rubber (X) is 30 to 99 parts by mass (preferably 35 to 97 parts by mass, more preferably 40 to 95 parts by mass), and a mineral oil-based softener (B1 ) Is 0 to 50 parts by mass (preferably 0 to 45 parts by mass, more preferably 0 to 40 parts by mass), and the α-olefin-based thermoplastic resin (C) is 1 to 50 parts by mass (preferably 2 to 45 parts by mass). , More preferably 5 to 40 parts by mass). As the mineral oil-based softener (B1) and the α-olefin-based thermoplastic resin (C), those exemplified above can be used.
[0055]
When the blending amount of the oil-extended rubber (X) is less than 30 parts by mass, the flexibility of the obtained thermoplastic elastomer tends to decrease. On the other hand, when the compounding amount of the oil-extended rubber (X) exceeds 99 parts by mass, the fluidity of the thermoplastic elastomer composition obtained by heat treatment in the presence of the crosslinking agent decreases, and the moldability decreases significantly. I do.
When the blending amount of the mineral oil-based softener (B1) to be added later exceeds 50 parts by mass, the copolymer rubber (A) constituting the oil-extended rubber (X) and the α-olefin-based thermoplastic resin in a kneading machine. In addition to the tendency of poor dispersion with (C), the rubber elasticity of the finally obtained thermoplastic elastomer composition of the present invention deteriorates.
[0056]
When the blending amount of the α-olefin-based thermoplastic resin (C) is less than 1 part by mass, when heat-treated in the presence of a crosslinking agent, the morphology of a good sea-island structure characteristic of a dynamically crosslinked thermoplastic elastomer. Are not formed and the thermoplastic elastomer is not formed. On the other hand, if the blending amount of the α-olefin-based thermoplastic resin (C) exceeds 50 parts by mass, the flexibility and rubber elasticity of the obtained thermoplastic elastomer decrease, which is not preferable. The α-olefin-based crystalline thermoplastic resin (c1) and the α-olefin-based amorphous thermoplastic resin (c2) may be used either alone or as a mixture of both.
[0057]
As the unmodified organopolysiloxane represented by the above (E1) and (F1) relating to the thermoplastic elastomer composition according to the second aspect, those exemplified above can be used.
The amount of the unmodified organopolysiloxane (E1) is 1 to 10 parts by mass, preferably 1 to 8 parts by mass, more preferably 1 to 10 parts by mass with respect to 100 parts by mass of the base polymer (D2) of the thermoplastic elastomer composition. 5 parts by mass. When the unmodified organopolysiloxane (E1) having a viscosity at 25 ° C. of less than 10,000 cSt specified by JIS K2283 alone is used, the organopolysiloxane may bleed out.
The blending amount of the unmodified organopolysilixane (F1) is 1 to 10 parts by mass, preferably 1 to 8 parts by mass, more preferably 1 to 5 parts by mass with respect to 100 parts by mass of the base polymer (D2). is there. When the organopolysiloxane (F1) having a viscosity at 25 ° C. of 10,000 cSt or more specified by JIS K2283 is used alone, the slidability tends to be insufficient, which is not preferable.
[0058]
By using the unmodified organopolysiloxane (E1) having a viscosity of less than 10,000 cSt at 25 ° C. specified in JIS K2283 and the unmodified organopolysiloxane (F1) having a viscosity of 10,000 cSt or more, the slidability is remarkably improved. As a combination of these compounding amounts, preferably the above (E1) is 1 to 10 parts by mass, the above (F1) is 1 to 10 parts by mass, more preferably the above (E1) is 1 to 5 parts by mass, the above (F1) ) Is 1 to 5 parts by mass.
[0059]
The thermoplastic elastomer composition according to claim 2 is represented by (G) above. acrylic As the modified organopolysiloxane, those exemplified above can be used. the above acrylic The compounding amount of the modified organopolysiloxane (G) is 0.2 to 20 parts by mass, preferably 0.5 to 15 parts by mass, more preferably 1 to 100 parts by mass based on 100 parts by mass of the base polymer (D2). To 10 parts by mass. this acrylic The modified organopolysiloxane (G) functions as a compatibilizer between the base polymer (D2) of the thermoplastic elastomer composition and the organopolysiloxane, rather than the effect of imparting slidability. Therefore, acrylic If the amount of the modified organopolysiloxane (G) is less than 0.2 parts by mass, the compatibility will not be good, and the unmodified organopolysiloxanes (E) and (F) and the base polymer (D2) will be mixed in a kneader. And the molding processability such as extrusion molding and injection molding tends to deteriorate. On the other hand, if it exceeds 20 parts by mass, the flexibility and physical properties tend to decrease.
[0060]
The thermoplastic elastomer composition according to claim 2 is characterized in that the resin / rubber composition (H2) obtained by mixing the above (X) and the above (C) to (G) is dynamically heat-treated in the presence of a crosslinking agent. Is done. The crosslinking agent used here is not particularly limited, but is not particularly limited as long as it can crosslink the copolymer rubber (A) by dynamic heat treatment. Examples and amounts of the crosslinking agent are the same as described above.
[0061]
The thermoplastic elastomer composition of the present invention may optionally contain a reinforcing material (carbon black, silica, etc.), a filler (clay, talc, calcium carbonate, etc.), a processing aid, a coloring agent, an antioxidant, an ultraviolet absorber, An antioxidant, a heat stabilizer, a lubricant, a release agent, a flame retardant, a foaming agent, an antistatic agent, an additive such as a fungicide, and the like can be added. Further, besides the copolymer rubber (A), the mineral oil-based softeners (B1 and B2), and the α-olefin-based thermoplastic resin (C), for example, natural rubber, polyisoprene rubber, polybutadiene rubber, Styrene-butadiene rubber, acrylonitrile-butadiene rubber, butyl rubber, acrylic rubber and the like may be added.
[0062]
According to a fourth aspect of the present invention, there is provided a method for producing a thermoplastic elastomer, comprising blending a crosslinking agent with the resin / rubber composition according to any one of the first to third aspects and supplying the same to a continuous extruder or a closed kneader. It is characterized by dynamic heat treatment.
As the cross-linking agent, those exemplified above can be used.
[0063]
The term "dynamically heat-treating" refers to performing both shearing force and heating. This dynamic heat treatment can be performed using, for example, a melt kneading apparatus. Among these, examples of the apparatus that can perform kneading include apparatuses such as an open-type mixing roll, a non-open-type Banbury mixer, a single-screw extruder, a twin-screw extruder, and a kneader. Among these, it is preferable to use a single-screw extruder and / or a twin-screw extruder from the viewpoint of economy, processing efficiency and the like. The processing performed by the kneading apparatus may be a batch type or a continuous type.
[0064]
The continuous extruder is not particularly limited as long as the thermoplastic elastomer composition can be melt-kneaded in the presence of a crosslinking agent. Examples thereof include a single-screw extruder, a twin-screw extruder, and a twin-screw extruder. And the like. Among them, a twin-screw extruder is preferably used, and a twin-screw extruder having an L / D (ratio of effective screw length L to outer diameter D) of preferably 30 or more, more preferably 36 to 60, is used. It is preferably used. As the twin-screw extruder, for example, any twin-screw extruder can be used, such as one in which two screws mesh with each other, and one in which they do not mesh with each other. Is more preferred. Examples of such a twin-screw extruder include GT manufactured by Ikegai Corporation, KTX manufactured by Kobe Steel, TEX manufactured by Japan Steel Works, TEM manufactured by Toshiba Machine Co., Ltd., and ZSK manufactured by Warner (all are trademarks).
[0065]
When producing a thermoplastic elastomer composition in the continuous extruder, the unmodified and acrylic As a method for supplying the modified organopolysiloxane, in the case of powder, there is a method in which the mixture is preliminarily mixed with a resin / rubber composition subjected to a crosslinking reaction using a mixer and supplied to the continuous extruder. In the case, a method of premixing with a resin / rubber composition subjected to a crosslinking reaction using a mixer and supplying the mixture to the continuous extruder, or supplying from a barrel opening provided between a feed hopper and a die There are methods.
[0066]
When the thermoplastic extruder is produced by the continuous extruder, the mineral oil-based softener (B1 and B2), the crosslinking agent and the crosslinking aid are supplied to the crosslinking reaction using a mixer. There is a method in which the resin is mixed with the resin / rubber composition in advance and supplied to the continuous extruder, or a method in which the mixture is supplied from a barrel opening provided between a feed hopper and a die.
[0067]
The above-mentioned closed kneader is not particularly limited as long as the resin / rubber composition can be melt-kneaded in the presence of a crosslinking agent, and examples thereof include a pressure kneader, a Banbury mixer, and a Brabender mixer.
[0068]
When producing a thermoplastic elastomer composition in the internal mixer, the unmodified and acrylic The modified organopolysiloxane, the mineral oil-based softeners (B1 and B2), the cross-linking agent and the cross-linking aid may be previously mixed with the α-olefin-based thermoplastic resin (C) or may be mixed without being pre-mixed. Each of them may be supplied into a closed kneader, and there is no particular limitation. Further, after the resin and rubber composition is melt-kneaded, acrylic Degeneration Organopolysiloxane The mineral oil-based softeners (B1 and B2), the crosslinking agent and the crosslinking aid may be added, or they may be melted and kneaded together with the resin / rubber composition from the beginning in the closed kneader. The procedure is not particularly limited.
Further, additives such as an inorganic filler can be supplied to the above-mentioned closed kneader or the above-mentioned continuous extruder.
[0069]
According to a fifth aspect of the present invention, there is provided a method for producing a thermoplastic elastomer composition, wherein the resin / rubber composition according to any one of the first to third aspects is melt-kneaded using a closed kneader, and then the resulting melt-kneaded product is crosslinked. It is characterized in that the agent is compounded and supplied to a continuous extruder, followed by dynamic heat treatment.
[0070]
As the closed kneader and the continuous kneader, those exemplified above can be used.
When the resin / rubber composition is melt-kneaded using the internal kneader except for the crosslinking agent, the unmodified and acrylic The modified organopolysiloxane and the mineral oil-based softener (B1) may be preliminarily mixed with the resin / rubber composition, or may be respectively supplied to the above-mentioned closed kneader without prior mixing. Is not limited. After the resin / rubber composition is melt-kneaded, the unmodified organopolysiloxanes (E) and (F), acrylic The modified organosiloxane (G) and the mineral oil-based softening agent (B1) may be added, or the resin and rubber composition may be put into the above-mentioned closed kneader together with the resin / rubber composition and melt-kneaded from the beginning. There is no particular limitation.
[0071]
The melt-kneaded material obtained by the above-mentioned closed kneader may be processed into pellets using a feeder ruder, or may be formed into a sheet once by a roll mill and then pelletized by a sheet pelletizer.
[0072]
When the resin / rubber composition is dynamically crosslinked using the continuous extruder, the method of supplying the crosslinking agent, the crosslinking aid and the mineral oil-based softener (B1) is as follows. And a method in which the mixture is preliminarily mixed with a resin / rubber composition and supplied to the continuous extruder, or supplied from a barrel opening provided between a feed hopper and a die.
[0073]
Additives such as inorganic fillers can be supplied to the above-mentioned closed kneader, can be supplied to the continuous extruder, or can be supplied to both extruders.
[0074]
According to a sixth aspect of the present invention, there is provided a method for producing a thermoplastic elastomer composition, comprising mixing a crosslinking agent with the resin / rubber composition according to any one of the first to third aspects and supplying the composition to a plurality of connected continuous kneaders. It is characterized by dynamic heat treatment.
[0075]
In the above-mentioned production method, for example, a resin / rubber composition is supplied to a first continuous kneader of two continuous kneaders connected to each other, and the resin is mixed in a first continuous extruder in the presence of a crosslinking agent. A method in which the rubber composition is kneaded and supplied to the second continuous extruder at a stage where the dynamic cross-linking reaction has not substantially proceeded to cause the dynamic cross-linking to proceed and cross-link.
[0076]
As the first continuous extruder, for example, a single-screw extruder, a twin-screw extruder, a twin-screw rotor type continuous kneader and the like can be mentioned, and among these, a twin-screw rotor type continuous extruder is particularly preferably used. Can be Examples of the twin-screw rotor type continuous extruder include CIM manufactured by Nippon Steel Works, Ltd. and Mixtron FCM, NCM, LCM, ACM manufactured by Kobe Steel Works (all are trademarks).
[0077]
The kneaded material in the first continuous extruder is preferably supplied to the second continuous extruder in a molten state, and the temperature of the kneaded material when supplied to the second continuous extruder is α -Although it depends on the melting point of the olefin-based thermoplastic resin, the kind of the crosslinking agent, and the like, it is preferably 140 to 250C, more preferably 150 to 240C, and still more preferably 150 to 230C.
[0078]
Examples of the second continuous extruder include a single-screw extruder, a twin-screw extruder, and a twin-screw rotor-type extruder. Of these, a twin-screw extruder is preferably used. A twin screw extruder having D (ratio of effective screw length L to outer diameter D) of preferably 30 or more, more preferably 36 to 60, is preferably used. As the twin-screw extruder, for example, an arbitrary twin-screw extruder such as one in which two screws mesh with each other or one in which two screws do not mesh with each other can be used. It is more preferable that the two screws rotate in the same direction and the screws mesh with each other. Examples of such a twin-screw extruder include GT manufactured by Ikegai Corporation, KTX manufactured by Kobe Steel, TEX manufactured by Japan Steel Works, TEM manufactured by Toshiba Machine Co., Ltd., and ZSK manufactured by Warner (all are trademarks).
[0079]
For example, when manufacturing a thermoplastic elastomer composition using an apparatus in which two continuous extruders are connected, the unmodified and acrylic As a method for supplying the modified organopolysiloxane, (1) A method of premixing with a resin / rubber composition subjected to a crosslinking reaction using a mixer and feeding the mixture to a first continuous extruder; (2) A method of feeding from a feed hopper of a first continuous extruder and / or a second continuous extruder, (3) Examples include a method of supplying from a barrel opening provided between a feed hopper and a die of the first continuous extruder and / or the second continuous extruder.
[0080]
The additives such as the mineral oil-based softener (B1) and the inorganic filler can be supplied to the first continuous extruder or the second continuous extruder. Can also be supplied to the machine.
[0081]
The conditions of the three types of dynamic heat treatments as set forth in claims 4 to 6 are not particularly limited, and vary depending on the melting point of the α-olefin-based thermoplastic resin (C), the type of the crosslinking agent, the kneading form, and the like. The temperature can be from 120C to 350C, more preferably from 140C to 320C, and even more preferably from 160C to 300C.
[0082]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples at all without departing from the gist thereof.
First, the oil-extended rubber (X), copolymer rubber, mineral oil-based softener (B1), α-olefin-based crystalline thermoplastic resin (c1), α-olefin-based amorphous thermoplastic used as the composition raw material Resin (c2), unmodified organopolysiloxane, acrylic The modified organopolysiloxane is shown below.
[0083]
[1] Oil-extended rubber (X)
(1) Oil-extended rubber 1: ethylene ・ propylene ・ 5-ethylidene-2-norbornene terpolymer
Ethylene content 66 mass%, 5-ethylidene-2-norbornene content 4.5 mass%, intrinsic viscosity 4.7 dl / g, mineral oil softener (trade name "PW-380", Idemitsu Entertainment 50% by mass
(2) Oil-extended rubber 2: ethylene ・ propylene ・ 5-ethylidene-2-norbornene terpolymer
Ethylene content 66 mass%, 5-ethylidene-2-norbornene content 4.5 mass%, intrinsic viscosity 3.8 dl / g, mineral oil-based softener (trade name "PW-380", Idemitsu Entertainment 40% by mass
[0084]
[2] Mineral oil-based softener (B1): trade name "PW-380", Idemitsu Entertainment Company
[3] α-olefin crystalline thermoplastic resin (c1)
(1) (c11): propylene ・ Ethylene random copolymer
Density 0.90g / cm ³ , MFR (temperature 230 ° C, load 2.16 kg) 23 g / 10 min. , Brand name "Novatech PP FL25R", manufactured by Nippon Polychem
(2) (c12): polypropylene polymer
Density 0.90g / cm ³ , MFR (temperature 230 ° C, load 2.16 kg) 3 g / 10 min. , Product name "Novatech PP MA4", manufactured by Nippon Polychem
[4] α-olefin amorphous thermoplastic resin (c2)
(1) Propylene ・ 1-butene amorphous copolymer
Propylene content 71 mol%, melt viscosity 8000 cps, density 0.879 g / cm ³ , Mn6500, trade name "APAO UT2780", manufactured by Ube Industries, Ltd.
[0085]
[5] Unmodified organopolysiloxane
(1) Polydimethylsiloxane
Viscosity 100cSt, trade name "Silicone Oil SH-200", Dow Corning Toray ·silicone Company
(2) Polydimethylsiloxane
Viscosity 1000cSt, trade name "Silicone Oil SH-200", Dow Corning Toray ·silicone Company
(3) Polydimethylsiloxane
Viscosity 5000cSt, trade name "Silicone Oil SH-200", Dow Corning Toray ·silicone Company
[0086]
[6] Unmodified organopolysiloxane
(1) Polydimethylsiloxane
Viscosity 12,500 cSt, trade name "Silicone Oil SH-200", manufactured by Dow Corning Toray Silicone Co., Ltd.
(2) Ultra high molecular weight silicone rubber
Viscosity 1,000,000 cSt or more, trade name "BY16-140", manufactured by Dow Corning Toray Silicone Co., Ltd.
[7] acrylic Modified organopolysiloxane (G)
Acrylic-modified silicone resin, trade name "x-22-8171", manufactured by Shin-Etsu Chemical Co., Ltd.
[0087]
Further, as a cross-linking agent 1, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane (trade name “Perhexa 25B-40”, manufactured by NOF CORPORATION) is used. N'-m-phenylenebismaleimide (trade name "Valnoc PM", manufactured by Ouchi Shinko Chemical Co., Ltd.) and divinylbenzene (manufactured by Sankyo Kasei Co., Ltd.) were used as a crosslinking assistant. Further, as an aging additive, "Irganox 1010" (trade name, manufactured by Nippon Ciba Geigy) was used.
[0088]
Examples 1 to 7 and Comparative Examples 1 to 5 (manufactured by a closed kneader and a continuous kneader)
The components excluding the crosslinking agent from the formulations shown in Tables 1 and 2 were charged into a pressure kneader (Moriyama Seisakusho) heated to 150 ° C. and kneaded at 40 rpm for 15 minutes until the components were uniformly dispersed. Thereafter, the composition in the molten state was pelletized by a feeder ruder (Moriyama Seisakusho). To the obtained pellets, a crosslinking agent and a crosslinking assistant were added in the mixing ratios shown in Tables 1 and 2, and mixed for 30 seconds with a Henschel mixer, and then, using a gravimetric feeder, a twin-screw extruder (unidirectional non-meshing type). Screw, L / D = 38.5, manufactured by Ikegai Co., Ltd., product name "PCM-45") at a discharge rate of 40 kg / h, while performing dynamic heat treatment at 200 ° C., screw rotation speed of 300 rpm, and residence time of 2 minutes. Extrusion was performed to obtain a thermoplastic elastomer composition.
[0089]
[Table 1]

[0090]
[Table 2]

[0091]
Evaluation of thermoplastic elastomer composition
The following items were measured in order to evaluate the thermoplastic elastomer composition obtained as described above.
[A] Melt flow rate (MFR)
The measurement was performed at 230 ° C. under a load of 10 kg, and the results are shown in Tables 1 and 2.
[B] Hardness, tensile strength at break and tensile elongation at break
It measured according to JIS-K6301.
[C] Compression set
According to JIS-K6301, the measurement was performed under the conditions of 70 ° C., 22 hours, and 25% compression.
[0092]
[D] Initial slidability and durable slidability
Using a reciprocating sliding tester (Tosoh Seimitsu Co., Ltd.), load 233 g / 3 cm ² (Surface pressure 78g / cm ² ), A glass ring test piece sliding speed = 100 mm / min (1 stroke = 50 mm), a cylindrical glass ring test piece having an outer diameter of 25.7 mm, an inner diameter of 20 mm, a height of 16.5 mm and a weight of 9.6 g, The static friction coefficient and the dynamic friction coefficient of a test piece (length 110 mm, width 61 mm, thickness 2 mm) prepared from the thermoplastic elastomer composition were measured. The initial slidability was measured at room temperature using one day after injection molding of a test piece of the thermoplastic elastomer composition. Durability was measured at room temperature by using a gear oven at 100 ° C. after 500 hours from injection molding.
[E] Bleed test
A test piece prepared from the thermoplastic elastomer composition was placed in a gear oven (manufactured by Toyo Seiki Co., Ltd.), left at 100 ° C. for 120 hours, and the surface state of the test piece was visually observed.
[0093]
[F] Extrusion processability
Using a Labo Plast mill extruder (Toyo Seiki Co., Ltd., outer diameter = 20 mm, L / D = 25), flat plate extrusion (25 mm width, 1.5 mm thickness) was performed under the following conditions, and the appearance was visually observed. Was evaluated.も の indicates that the surface is smooth and has an edge, and x indicates all others.
Cylinder C1 = 180 ° C
Cylinder C2 = 190 ° C
Cylinder C3 = 210 ° C
Die = 205 ° C
Screw rotation speed: 40 rpm
[G] Injection fusion
Using a test piece injection-fused thermoplastic elastomer composition, starting from the joint between the thermoplastic elastomer composition and the adherend, visually observe the peeling state when bent at an angle of 180 °, The results are shown in Tables 1 and 2.
In Tables 1 and 2, ○, Δ, and × are based on the following evaluation criteria.
；: Without peeling
△: Partial peeling
×: peeling and breaking
[0094]
With respect to the above [A] to [E], test pieces were prepared by the following method. That is, a test piece obtained by injection-molding the thermoplastic elastomer composition obtained as described above into a size of 120 × 120 × 2 mm using an injection molding machine (model “N-100”, manufactured by Nippon Steel Corporation) was used. Produced.
[0095]
Regarding the above [G], an adherend made of an olefin-based vulcanized rubber was prepared as described below and subjected to a test.
ethylene ・ propylene ・ 100 parts by mass of a 5-ethylidene-2-norbornene terpolymer (ethylene content 72 mol%, propylene content 28 mol%, Mooney viscosity 92, iodine value 15, trade name "EP 103A", manufactured by JSR) 145 parts by mass of carbon black (trade name “SEIST 116”, manufactured by Tokai Carbon Co., Ltd.) and paraffin-based process oil (trade name “PW − 380 ", 85 parts by mass of Idemitsu Kosan Co., Ltd., 5 parts by mass of activated zinc flower (manufactured by Sakai Chemical Industry Co., Ltd.), 1 part by mass of stearic acid (manufactured by Asahi Denka Kogyo Co., Ltd.), a processing aid (trade name" Hitanol 1501 " A mixture was obtained in which 1 part by mass of Hitachi Chemical Co., Ltd., 2 parts by mass of a release agent (trade name “Stractor WB212”, manufactured by Syl and Zilaher Company) and 1 part by mass of a plasticizer (polyethylene glycol) were obtained. .
This mixture was kneaded using a Banbury mixer under the conditions of 50 ° C., 70 rpm, and a kneading time of 2.5 minutes. Then, 10 parts by mass of a dehydrating agent (trade name "Vesta PP", manufactured by Inoue Lime Industry Co., Ltd.), a vulcanization accelerator (trade name "M" 1 part by mass, trade name "PX" 1 part by mass, trade name "TT") 0.5 parts by mass, 1 part by mass of trade name “D”, all manufactured by Ouchi Shinko Chemical Co., Ltd.) and 2.2 parts by mass of sulfur were added, and kneaded at 50 ° C. using an open roll. Then, it was vulcanized at 170 ° C. for 10 minutes to obtain a vulcanized rubber sheet having a size of 120 mm square and a thickness of 2 mm. The sheet was punched out with a dumbbell cutter to a length of 60 mm and a width of 50 mm to obtain an adherend.
that's all
[0096]
Effects of the embodiment
Comparative Examples 1 to 3 are examples in which only low-viscosity unmodified organopolysiloxane is used, and no acrylic-modified organopolysiloxane is contained, and are excellent in extrusion processability and injection fusion property. Bleeding was observed. Comparative Example 4 is an example using only a high-viscosity unmodified organopolysiloxane and containing no acrylic-modified organopolysiloxane, and is excellent in extrusion processability and injection fusion property, but inferior in initial and durability sliding properties. I was Comparative Example 5 is an example in which low-viscosity and high-viscosity unmodified organopolysiloxanes are contained, but does not contain an acrylic-modified organopolysiloxane, and is inferior in initial and endurance slidability, extrusion processability, and injection-fusibility. And bleed was confirmed.
On the other hand, the thermoplastic elastomer compositions of Examples 1 to 7 are excellent in slidability and extrudability in the initial stage and in durability, and no bleeding of organopolysiloxane is observed. In addition, no peeling, breakage or the like was observed in the injection fusion property, indicating that the composition has excellent injection fusion property.
[0097]
【The invention's effect】
According to the present invention, a thermoplastic elastomer composition that can be easily processed by injection molding, extrusion molding, hollow molding, compression molding, vacuum molding, lamination molding, calendar molding, or the like can be obtained. Further, it is possible to obtain a thermoplastic elastomer composition having excellent extrudability, slidability, injection-fusing property to vulcanized rubber, and excellent molding appearance and touch. In particular, the slidability shows excellent properties not only in the initial stage but also for a long period.

Claims (6)

20 to 69 parts by mass of ethylene / α-olefin-based copolymer rubber (A), 20 to 79 parts by mass of mineral oil-based softener (B1), and α-olefin-based crystalline thermoplastic resin (c1) and / or α When the base polymer (D1) composed of 1 to 50 parts by mass of an α-olefinic thermoplastic resin (C) composed of an olefinic amorphous thermoplastic resin (c2) is 100 parts by mass, JIS K2283 1 to 10 parts by mass of an unmodified organopolysiloxane (E1) having a viscosity at 25 ° C. of less than 10,000 cSt, 1 to 10 parts by mass of an unmodified organopolysiloxane (F1) having a viscosity of 10,000 cSt or more, and acrylic A resin / rubber composition (H1) containing 0.2 to 20 parts by mass of a modified organopolysiloxane (G) is dynamically heat-treated in the presence of a crosslinking agent. Thermoplastic elastomer composition according to claim. An oil extension comprising 30 to 70% by mass of an ethylene / α-olefin-based copolymer rubber (A) and 30 to 70% by mass of a mineral oil-based softening agent (B2) (provided that (A) + (B2) = 100% by mass). 30 to 99 parts by mass of rubber (X), 0 to 50 parts by mass of mineral oil-based softener (B1), and α-olefin-based crystalline thermoplastic resin (c1) and / or α-olefin-based amorphous thermoplastic When the base polymer (D2) composed of 1 to 50 parts by mass of the α-olefin-based thermoplastic resin (C) composed of the resin (c2) is 100 parts by mass, the viscosity at 25 ° C. specified by JIS K2283 is used. there unmodified organopolysiloxane (E1) 1 to 10 parts by weight is less than 10,000 cSt, and unmodified organopolysiloxane (F1) 1 to 10 parts by mass of viscosity is more than 10,000 cSt, acrylic-modified Olga A thermoplastic elastomer obtained by dynamically heat-treating a resin / rubber composition (H2) obtained by mixing 0.2 to 20 parts by mass of a polysiloxane (G) in the presence of a crosslinking agent. Composition. The heat according to claim 1 or 2, wherein the intrinsic viscosity [η] of the ethylene / α-olefin copolymer rubber (A) measured at 135 ° C in a decalin solvent is 3.5 to 6.8 dl / g. Plastic elastomer composition. A thermoplastic resin, which is characterized in that a crosslinking agent is blended with the resin / rubber composition according to any one of claims 1 to 3, and the resulting mixture is supplied to a continuous extruder or a closed kneader to be dynamically heat-treated. A method for producing an elastomer composition. The resin / rubber composition according to any one of claims 1 to 3 is melt-kneaded using an internal kneader, and then a crosslinking agent is blended into the melt-kneaded material and supplied to a continuous extruder to form a dynamic mixture. A method for producing a thermoplastic elastomer composition, comprising heat-treating a thermoplastic elastomer composition. A thermoplastic elastomer composition comprising a crosslinking agent mixed with the resin / rubber composition according to any one of claims 1 to 3, supplied to a plurality of connected continuous kneaders, and dynamically heat-treated. Method of manufacturing a product.