JP3603404B2 - Manufacturing method of resin composite - Google Patents

Description

【００１７】
【発明の作用および効果】
本願発明によれば、上記押出機は上記両樹脂を混練する回転スクリューを備えており、押出機における上流側に上記高温部を設ける一方、その下流側に上記低温部を設け、高温部に上記熱可塑性液晶樹脂材料を投入するようにしたので、この液晶樹脂は、上記第１温度で可塑化・溶融された後、下流側の低温部で上記第２温度まである程度急速に温度が降下させられることになり、液晶樹脂の粘度は、この温度変化に対してかなりの時間遅れを伴って上昇する、つまり、この温度変化にも拘わらず、第１温度若しくは該第１温度に比較的近い温度での粘度と同レベルの粘度が、ある程度の間保持され、いわば記憶される。そして、上記低温部に熱可塑性マトリックス樹脂材料を投入することにより、このマトリックス樹脂は上記第２温度で可塑化・溶融される。このとき、このマトリックス樹脂と上流側からの液晶樹脂とが合流することになる。そして、その後、上記両樹脂を押し出しながら延伸するようにしたので、両樹脂の粘度の温度に対する変化特性および可塑化・溶融温度の違いにも拘わらず、押出・延伸時の粘度差を極力小さくすることができる。
【００１８】
すなわち、高温部を熱可塑性液晶樹脂の液晶転移温度以上の第１温度に設定し、この第１温度で液晶樹脂を可塑化・溶融させることで、該液晶樹脂は、第１温度若しくは該第１温度に比較的近い温度での粘度と同レベルの粘度を記憶したまま、低温部においてマトリックス樹脂と混合して調製される。このように、上流側（高温部）と下流側（低温部）とで異なる可塑化・溶融温度を設定することにより、両樹脂の粘度比を制御することが可能となり、糸引き性を（従って、延伸比を）向上させることができる。この場合において、マトリックス樹脂は低温部（第２温度）で可塑化・溶融され、その温度を該マトリックス樹脂の溶融温度（結晶性でないものにあっては、最低成形可能温度）に対して過度に高く設定する必要がないので、マトリックス樹脂の劣化を確実に防止することができる。
この結果、糸引き性を向上させて延伸比を高めることが可能になり、また、マトリックス樹脂の劣化を確実に回避することができ、液晶樹脂複合材の強度を向上させることができる。
【００１９】
【発明の実施の形態】
以下、本発明の実施の形態について、添付図面を参照しながら詳細に説明する。図１は本実施の形態に係る押出機の要部を示す部分縦断面説明図であるが、この図に示すように、上記押出機１は、熱可塑性マトリックス樹脂中に該マトリックス樹脂の最低成形可能温度よりも高い液晶転移温度を有する熱可塑性液晶樹脂が繊維状態で存在してなる樹脂複合材を押し出すもので、基台２上に固定された円筒状の本体３と、該本体３の先端に設けられたノズルヘッド部４と、本体３内に収納された回転スクリュー５とを備えるとともに、本体３の上部には上流側から順に第１および第２の二つのホッパ６，７が設けられている。
【００２０】
本実施の形態では、上記押出機１における上流側、つまり上記両ホッパ６，７の間に、内部の樹脂材料を熱可塑性液晶樹脂の液晶転移温度付近もしくはそれ以上の第１温度Ｔ１で可塑化・溶融させる高温部１１が設けられる一方、上記押出機１における下流側、つまり第２ホッパ７の下流側に、内部の樹脂材料を熱可塑性マトリックス樹脂の最低成形可能温度よりも高く上記第１温度Ｔ１よりも低い第２温度Ｔ２で可塑化・溶融させる低温部１２が設けられている。
すなわち、上記高温部１１では本体３の周囲を取り巻く加熱ヒータ１３（第１ヒータ）の設定温度が第１温度Ｔ１にセットされ、また、低温部１２では本体３の周囲を取り巻く加熱ヒータ１４（第２ヒータ）の設定温度が第２温度Ｔ２にセットされている。
尚、熱可塑性液晶樹脂を可塑化・溶融させる場合、通常、該液晶樹脂はその液晶転移温度として表示された温度以上に加熱されるが、実際には、この液晶転移温度よりもある程度低い温度でも液晶樹脂が可塑化・溶融し得ることが経験されている。従って、上記高温部１１の設定温度Ｔ１は、必ずしも当該液晶樹脂の液晶転移温度以上である必要はなく、この液晶転移温度付近でそれよりもある程度低い温度でも良い。
【００２１】
そして、上記両ヒータ１３及び１４をＯＮして高温部１１および低温部１２を各々の設定温度Ｔ１及びＴ２にセットした状態で、まず、上記第１ホッパ６に、例えば所定長さに切り揃えられた繊維状の熱可塑性液晶樹脂ＬＣＰを投入するとともに、図示しない駆動装置によって上記回転スクリュー５を所定の回転数で駆動する。これにより、第１ホッパ６から投入された熱可塑性液晶樹脂は、高温部１１において回転スクリュー５により混練されながら第１温度Ｔ１で可塑化溶融される。
続いて、第２ホッパ７に、上記液晶樹脂ＬＣＰの液晶転移温度よりも低い最低成形可能温度（結晶性のものにあっては融点）を有する例えばペレット状の熱可塑性マトリックス樹脂ＭＰを投入する。この第２ホッパ７から投入されたマトリックス樹脂ＭＰのペレットは、低温部１２において回転スクリュー５により混練されながら第２温度Ｔ２で可塑化溶融される。
【００２２】
このとき、上記高温部１１で可塑化・溶融された液晶樹脂ＬＣＰは低温部１２まで達しており、その温度は第１温度Ｔ１から第２温度Ｔ２まで降下している。そして、この低温部１２で、液晶樹脂ＬＣＰと上記マトリックス樹脂ＭＰとが合流して一緒に混練されながらノズルヘッド部４まで押し出され、その結果、マトリックス樹脂ＭＰ中に液晶樹脂ＬＣＰが繊維状に配向したストランド状の液晶樹脂複合材がノズルヘッド部４のノズル孔４ａから押し出される。
上記押出機１の外部下流側には、具体的には図示しなかったが、押し出された液晶樹脂複合材を冷却する冷却槽と、押出状態にある液晶樹脂複合材を延伸させつつ下流側に引き出す延伸装置とが設けられており、上記両樹脂を押出機１で押し出しながら延伸することにより、熱可塑性マトリックス樹脂ＭＰ中に該マトリックス樹脂ＭＰの最低成形可能温度よりも高い液晶転移温度を有する熱可塑性液晶樹脂ＬＣＰが繊維状態で存在してなる所定強度の樹脂複合材が得られるようになっている。
【００２３】
以上のように、本実施の形態に係る押出機１では、その上流側部分に内部の樹脂材料を第１温度Ｔ１（熱可塑性液晶樹脂ＬＣＰの液晶転移温度付近もしくはそれ以上の温度）で可塑化・溶融させる高温部１１が設けられる一方、その下流側部分に内部の樹脂材料を第２温度Ｔ２（熱可塑性マトリックス樹脂ＭＰの最低成形可能温度よりも高く上記第１温度よりも低い温度）で可塑化・溶融させる低温部１２が設けられており、第１ホッパ６から投入されて上記高温部１１で可塑化・溶融された液晶樹脂ＬＣＰは、下流側の低温部１２でその温度が第１温度Ｔ１から第２温度Ｔ２まである程度以上急速に降下させられる。そして、この低温部１２で、上記液晶樹脂ＬＣＰと第２ホッパ７から投入された上記マトリックス樹脂ＭＰとが一緒に混練されながら押し出される。
【００２４】
マトリックス樹脂ＭＰに比して粘度が高い液晶樹脂ＬＣＰは、一旦、第１温度Ｔ１に維持されその粘度が当該第１温度Ｔ１に対応する粘度に保たれた後、その樹脂温が第１温度Ｔ１よりも低い第２温度Ｔ２まである程度以上急速に低下させられることになるが、この場合、前述のように、液晶樹脂ＬＣＰの粘度は直ちにこの第２温度Ｔ２に対応する粘度まで上昇するのではなく、温度変化に対してかなりの時間遅れを伴って上昇する、つまり、この温度変化にも拘わらず、高温（第１温度Ｔ１）若しくは該温度に比較的近い温度での粘度と同レベルの粘度がある程度の間は保持される（いわば記憶される）ので、上記第１温度Ｔ１および第２温度Ｔ２を適切に設定することにより、液晶樹脂ＬＣＰとマトリックス樹脂ＭＰの粘度差をできるだけ小さく維持した状態で、両樹脂を押し出しながら延伸することができ、強度の高い液晶樹脂複合材を得ることができるのである。
【００２５】
次に、調製時における両樹脂の粘度比と得られた液晶樹脂複合材の強度との関係を調べた実験例について説明する。
図２は、熱可塑性液晶樹脂と熱可塑性マトリックス樹脂とを同一温度で調製する場合において、つまり、材料投入ホッパが上流部分の１箇所のみに設けられた従来の押出機を用いて、両樹脂材料を同一温度で調製して押し出す場合において、調製温度と粘度比との関係を調べた結果を示すグラフである。
また、図３は、同様に、従来の押出機を用いて両樹脂材料を同一温度で調製して押し出しながら延伸をかけた場合において、調製温度と得られた液晶樹脂複合材の引張強度との関係を調べた結果を示すグラフである。
【００２６】
この図２および図３の各グラフから分かるように、熱可塑性液晶樹脂と熱可塑性マトリックス樹脂の粘度比は、調製温度がある一定値（約３００℃：図２参照）よりも低くなると立ち上がるようにして高くなるが、この粘度比が１に近くなる温度（約３００℃付近）で調製した場合に、得られる液晶樹脂複合材の強度がほぼ極大に近くなる（図３参照）。
尚、この材料系では、温度が３１０℃を越えると、全体としての粘度が低下するため、糸引き性が悪くなる。このため、延伸比が低下し、延伸をかけた場合、延伸自体は可能であっても、出来上がった複合材にいわゆる波打ちが生じる、或いは、液晶樹脂に比して可塑化溶融される温度が低いマトリックス樹脂が劣化するなどの不具合が生じ易くなり、複合材の強度は低下し始めている。
【００２７】
上記図２および図３で示された実験で用いた熱可塑性液晶樹脂および熱可塑性マトリックス樹脂は、以下の通りであった。
・ 熱可塑性液晶樹脂
− 材質名 ： 芳香族ポリエステル樹脂
− 商品名 ： ベクトラＡ９５０（ポリプラスチックス株式会社製）
− 液晶転移温度 ： ２８０〜２９０℃
・ 熱可塑性マトリックス樹脂
− 材質名 ： ポリプロピレン（ＰＰ）樹脂
− 商品名 ： ノーブレンＨ５０１（住友化学工業株式会社製）
− 融点 ： １６５〜１７０℃（通常成形温度：１９０℃以上）
【００２８】
次に、熱可塑性液晶樹脂に関し、該液晶樹脂に温度変化（高温から低温への変化）を与えた場合における時間経過と液晶樹脂の粘度変化との関係を調べた実験結果について、図４のグラフを参照しながら説明する。
尚、本実験では、熱可塑性液晶樹脂として、上述のベクトラＡ９５０（ポリプラスチックス株式会社製）を用いた。
また、本実験で用いた実験装置および設定条件並びに実験方法は、以下の通りであった。
・ 実験装置 ： キャピラリーレオメータ
・ ダイ径 ： １．０ｍｍ
・ 剪断速度 ： １８００／ｓ
・ 実験方法 ： 熱可塑性液晶樹脂を初期温度（２５０℃）から一定温度間隔（１０℃）で昇温させ、ある所定温度（第１温度）に達すると一定時間（約１０分間程度）保持して安定化させる。その後、バレル温度を第２温度（２７０℃）に降下させ始めた際の、液晶樹脂の粘度の経時変化、およびバレル温度が実際に上記第２温度まで低下するまでの所要時間等を測定した。
【００２９】
上記図４のグラフにおいて、実線曲線Ａは、液晶樹脂を初期温度（２５０℃）から一定温度間隔（１０℃）で昇温させた際の粘度変化特性を示している。尚、各温度での粘度の測定値を、表１の第Ｉ欄に示した。
また、上記実線曲線Ａにおける２７０℃，３００℃，３３０℃及び３４０℃のポイントの右側にプロットされた白丸（○）群Ｃ０，Ｃ１，Ｃ２及びＣ３は、上記各温度（第１温度）で一定時間（約１０分間程度）保持して安定化させた場合の液晶樹脂粘度の経時変化を示している。尚、その一定時間保持（ホールド）後の粘度の測定値を、上記表１の第ＩＩ欄に示した。ちなみに、この場合、２７０℃の温度では、一定時間保持後の粘度（４２０Ｐａ・ｓ）がかなり高く、液晶樹脂が少なくとも十分には溶融していないことを示している。
【００３０】
【表１】

【００３１】
更に、図４のグラフにおいて、破線曲線Ｂ１，Ｂ２，Ｂ３は、各所定温度（第１温度）において一定時間（約１０分間程度）保持して安定化させた後、バレル温度を第２温度（２７０℃）に降下させ始めた際の、液晶樹脂の粘度の経時変化をそれぞれ示しており、また、各曲線上のポイントＰ１，Ｐ２，Ｐ３は、バレル温度が実際に上記第２温度（２７０℃）まで低下した時点を示している。尚、上記各破線曲線Ｂ１，Ｂ２，Ｂ３に対応する粘度の測定値を表１の第ＩＩＩ欄に示し、上記各ポイントＰ１，Ｐ２，Ｐ３を、この表１第ＩＩＩ欄中で測定値に括弧を付してそれぞれ示した。
また、更に、図４のグラフにおいて、一点鎖線直線Ｄは、この液晶樹脂の液晶転移温度（２８０〜２９０℃）付近の代表的な温度に対応した粘度を表す基準線である。
【００３２】
図４のグラフ及び表１のデータより、液晶樹脂は、バレル温度が第２温度（２７０℃）まで下がっても、高温での粘度をある期間保っており、特に、液晶転移温度付近の温度での粘度を、第１温度のレベルに応じて、以下の期間にわたって保持していることが判る。
・ 第１温度が３００℃の場合：約１０分間
・ 第１温度が３３０℃の場合：約３５分間
・ 第１温度が３４０℃の場合：約２５分間
従って、 このデータ例によれば、第１温度を３３０℃に設定すれば、液晶樹脂について液晶転移温度付近の温度での粘度が最もよく記憶されることになる。
【００３３】
一方、図５は、本実施の形態で用いた熱可塑性液晶樹脂（ベクトラＡ９５０：ポリプラスチックス株式会社製）および熱可塑性マトリックス樹脂（下記参照）の温度と粘度との関係について、別途に行った実験結果を示すグラフである。このグラフにおいて、曲線Ｈが液晶樹脂の粘度変化を、また、曲線Ｊ，Ｋがマトリックス樹脂の粘度変化をそれぞれ示している。
尚、上記図５で示された実験では、熱可塑性マトリックス樹脂として、前述のノーブレンＨ５０１（住友化学工業株式会社製）を用いた。
【００３４】
図５のグラフより、液晶樹脂の繊維化状態を良好に維持しつつ、液晶樹脂とマトリックス樹脂の粘度比を約１にするには、液晶樹脂は、その液晶転移温度（２８０〜２９０℃）付近の粘度を記憶させ、マトリックス樹脂は、この粘度と同レベルとなるように、約２２０〜２７０℃の範囲の温度で可塑化・溶融させれば良いことが分かる。
【００３５】
また、本発明の実施の形態に係る押出機１（図１参照）を用いて熱可塑性液晶樹脂と熱可塑性マトリックス樹脂をそれぞれ異なる温度で可塑化・溶融させて押し出し・延伸した本発明実施の形態と、従来の押出機を用いて上記両樹脂を同一温度で可塑化・溶融させて押し出し・延伸した比較例とについて、得られた液晶樹脂複合材の引張強度を測定する強度試験を行った。
本試験に用いた材料及び装置並びに試験条件等は、以下の通りであった。
ａ）材料
・ 熱可塑性液晶樹脂 ：ベクトラＡ９５０（密度１．４ｇ／ｃｍ^３）
・ 熱可塑性マトリックス樹脂：ノーブレンＨ５０１（密度０．９ｇ／ｃｍ^３）
これら材料樹脂を、液晶樹脂が６０重量％，マトリックス樹脂が４０重量％の割合で配合させた。
ｂ）装置
従来から良く知られている２軸混練機を用いた。
【００３６】
ｃ）押出条件
・ キャピラリー径：２ｍｍ（直径）×２０ｍｍ
・ 押出量 ：約６．１ｋｇ／ｈｒ
・ 剪断速度：１８００／ｓｅｃ．
ｄ）可塑化・溶融温度
・ 本発明実施の形態 − 高温部（上流側／液晶樹脂）：３３０℃
− 低温部（下流側／マトリックス樹脂）：２７０℃
・ 比較例 ： ３３０℃（上流側のみ／両樹脂同一温度）
ｅ）以上の条件で、延伸比を種々異ならせてサンプルを作製し、それぞれ引張強度を測定した。
【００３７】
試験結果は、図６のグラフに示す通りであった。
このグラフから分かるように、本発明実施の形態および比較例の両方について、延伸比を高くするほど引張強度が向上している。
また、本発明実施の形態（最大延伸比１７）の方が、比較例（最大延伸比１３）よりも延伸比を高く設定することが可能であることが確かめられた。これは、本発明実施の形態では、液晶樹脂を高温部（第１温度）で可塑化・溶融させ、該液晶樹脂に第１温度若しくは該第１温度に比較的近い温度での粘度と同レベルの粘度を記憶させたまま、低温部（第２温度）においてマトリックス樹脂と混合して調製されるので、両樹脂の粘度比を制御することができ、本発明実施の形態の方が比較例よりも、液晶樹脂とマトリックス樹脂の粘度差を小さく（つまり粘度比を１により近く）することができることによるものと考えられる。
更に、延伸比が同じでも、本発明実施の形態の方が比較例よりも大幅に引張強度が高くなることが確認できた。これは、本発明実施の形態では、液晶樹脂とマトリックス樹脂の可塑化・溶融温度を異ならせ、マトリックス樹脂を低温部で可塑化・溶融させるようにしたので、該マトリックス樹脂の劣化が確実に防止できることによるものと考えられる。
【００３８】
以上、説明したように、本実施の形態によれば、押出機１における上流側に高温部１１を設ける一方、その下流側に低温部１２を設け、高温部１１に熱可塑性液晶樹脂材料ＬＣＰを投入するようにしたので、この液晶樹脂ＬＣＰは、上記第１温度Ｔ１で可塑化・溶融された後、下流側の低温部１２で上記第２温度Ｔ２まである程度急速に温度が降下させられることになり、液晶樹脂ＬＣＰの粘度は、この温度変化に対してかなりの時間遅れを伴って上昇する、つまり、この温度変化にも拘わらず、第１温度Ｔ１若しくは該第１温度Ｔ１に比較的近い温度での粘度と同レベルの粘度が、ある程度の間保持され、いわば記憶される。そして、上記低温部１２に熱可塑性マトリックス樹脂材料ＭＰを投入することにより、このマトリックス樹脂ＭＰは上記第２温度Ｔ２で可塑化・溶融される。このとき、このマトリックス樹脂ＭＰと上流側からの液晶樹脂ＬＣＰとが合流することになる。そして、その後、上記両樹脂ＬＣＰ，ＭＰを押し出しながら延伸するようにしたので、両樹脂ＬＣＰ，ＭＰの粘度の温度に対する変化特性および可塑化・溶融温度の違いにも拘わらず、押出・延伸時の粘度差を極力小さくすることができるのである。
【００３９】
すなわち、高温部１１を熱可塑性液晶樹脂ＬＣＰの液晶転移温度付近もしくはそれ以上の第１温度Ｔ１に設定し、この第１温度Ｔ１で液晶樹脂ＬＣＰを可塑化・溶融させることで、該液晶樹脂ＬＣＰは、第１温度Ｔ１若しくは該第１温度Ｔ１に比較的近い温度での粘度と同レベルの粘度を記憶したまま、低温部１２においてマトリックス樹脂と混合して調製される。このように、上流側（高温部１１）と下流側（低温部１２）とで異なる可塑化・溶融温度を設定することにより、両樹脂ＬＣＰ，ＭＰの粘度比を制御することが可能となり、糸引き性を（従って、延伸比を）向上させることができる。この場合において、マトリックス樹脂ＭＰは低温部１２（第２温度）で可塑化・溶融され、その温度を該マトリックス樹脂の溶融温度（結晶性でないものにあっては、最低成形可能温度）に対して過度に高く設定する必要がないので、マトリックス樹脂ＭＰの劣化を確実に防止することができる。
この結果、糸引き性を向上させて延伸比を高めることが可能になり、また、マトリックス樹脂ＭＰの劣化を確実に回避することができ、液晶樹脂複合材の強度を向上させることができるのである。
本願発明に係る方法は、熱可塑性液晶樹脂の液晶転移温度と熱可塑性マトリックス樹脂の溶融温度（結晶性でないものにあっては最低成形可能温度）との差が大きい材料樹脂の組み合わせの場合には、マトリックス樹脂の劣化防止のために、特に有効である。
【００４０】
尚、上記実施の形態では、熱可塑性液晶樹脂ベクトラＡ９５０（芳香族ポリエステル樹脂）と組み合わされる熱可塑性マトリックス樹脂としてノーブレンＨ５０１（ポリプロピレン（ＰＰ）樹脂）が用いられていたが、この替わりに、以下に示すような、他の種々のマトリックス樹脂を用いることが可能である。
・ＰＰ（ポリプロピレン）樹脂：ノーブレンＤ５０１など（住友化学工業株式会社製）
・ＡＢＳ（アクリロニトリル−ブタジエン−スチレン共重合体）樹脂：クラスチックＭＨなど（住友ダウ株式会社製）
・ＰＣ（ポリカーボネイト）樹脂：レキサン１４１など（日本ジーイープラスチック株式会社製）
・ＰＣ／ＡＢＳ樹脂：テクニエースＴ１０５など（住友ダウ株式会社製）
・ＰＡ（ポリアミド）樹脂：ナイロン１０１３Ｂ，１０３０Ｂ，１０１８Ｉなど（宇部興産株式会社製）
・ＰＰＥ／ＰＡ６（ポリフェニレンエーテル／ナイロン６）樹脂：ノリルＧＴＸ６００６など（日本ジーイープラスチック株式会社製）
・ＰＳ（ポリスチレン）樹脂：エスブライト９Ｍなど（昭和電工株式会社製）
・ＰＢＴ（ポリブチレンテレフタレート）：１４０１−Ｘ０７など（東レ株式会社製）
・変性ＰＰＥ樹脂：ノリルＰＸ２６２３など（日本ジーイープラスチック株式会社製）
・ＰＣ／ＰＢＴ樹脂：ゼノイ１１０１など（日本ジーイープラスチック株式会社製）
【００４１】
尚、本発明は、以上の実施態様に限定されるものではなく、その要旨を逸脱しない範囲において、種々の改良あるいは設計上の変更が可能であることは言うまでもない。
【図面の簡単な説明】
【図１】本発明の実施の形態に係る押出機の要部を示す部分縦断面説明図である。
【図２】熱可塑性液晶樹脂と熱可塑性マトリックス樹脂とを同一温度で調製する場合における調製温度と粘度比との関係の一例を示すグラフである。
【図３】熱可塑性液晶樹脂と熱可塑性マトリックス樹脂とを同一温度で調製する場合における調製温度と引張強度との関係の一例を示すグラフである。
【図４】熱可塑性液晶樹脂に温度変化を与えた場合における時間経過と粘度変化との関係の一例を示すグラフである。
【図５】熱可塑性液晶樹脂および熱可塑性マトリックス樹脂の温度と粘度との関係の一例を示すグラフである。
【図６】上記押出機で得られた液晶樹脂複合材と従来方法で得られた液晶樹脂複合材の強度特性を比較して示すグラフである。
【符号の説明】
１…押出機
１１…高温部
１２…低温部
ＬＣＰ…熱可塑性液晶樹脂
ＭＰ…熱可塑性マトリックス樹脂
Ｔ１…第１温度
Ｔ２…第２温度[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for producing a resin composite material, and more particularly to a method for producing a resin composite material in which a thermoplastic liquid crystal resin is used as a reinforcing fiber, and the liquid crystal resin is present in a matrix resin in a fibrous state.
[0002]
[Prior art]
In recent years, it has been proposed to use a thermoplastic liquid crystal resin as a reinforcing fiber of a fiber-reinforced resin material. For example, Japanese Patent Application Laid-Open No. Sho 62-116666 discloses a liquid crystal resin composite in which a thermoplastic liquid crystal resin is used as a reinforcing fiber, which is formed into a fibrous shape.
When the thermoplastic liquid crystal resin is used as the reinforcing fiber, when the used and discarded resin molded product is recycled, the thermoplastic liquid crystal resin fiber as the reinforcing fiber is cut along with the grinding of the resin molded product. However, by heating the material to a temperature higher than the liquid crystal transition temperature of the liquid crystal resin and preparing the material, the fibrous state of the liquid crystal resin as a reinforcing material can be easily reproduced, and conventionally, fiber reinforcement of glass fiber, carbon fiber, etc. It is possible to achieve a significant improvement in recyclability, which is generally difficult with resin molded products and can be recycled into a material having the same physical properties.
[0003]
As a production method for producing such a resin composite material, an extruder is used to plasticize and melt a thermoplastic liquid crystal resin and a thermoplastic matrix resin, and then the liquid crystal resin becomes fibrous in the matrix resin. In addition, there is known a method of obtaining a resin composite material in which the fibrous liquid crystal resin (liquid crystal fiber) is used as a reinforcing fiber by performing stretching while extruding both. For example, Japanese Patent Application Laid-Open No. 6-320629 discloses a strand-like liquid crystal resin composite in which a liquid crystal resin and a matrix resin are plasticized, melted, and extruded at the same temperature higher than the liquid crystal transition temperature of the liquid crystal resin. A method for supplying a material is disclosed.
In this type of method, in order to maintain the fibrous state of the liquid crystal resin in good condition and obtain a certain or more mechanical property, at the time of extrusion, a shear rate of a predetermined value or more is applied and a drawing ratio of a predetermined value or more is applied. Need to be done.
When such a resin composite is prepared by such a method, optimizing the preparation conditions, particularly securing the above-mentioned draw ratio at a certain level or more, requires higher performance (higher strength) of the resin composite. It is important to achieve.
[0004]
[Problems to be solved by the invention]
In order to increase the draw ratio, it is necessary to improve the so-called stringiness of the liquid crystal resin and the matrix resin, and for this purpose, it is important to set the viscosity ratio between the two.
As a result of intensive studies from such a viewpoint, the present inventor has found that a composite material having higher strength can be obtained as the viscosity ratio is closer to 1 (that is, as the difference in viscosity between the two is smaller).
This is considered to be because if the difference between the viscosity of the liquid crystal resin and the viscosity of the matrix resin is greater than a certain level, "unevenness" occurs in the tensile action on both when the stretching is applied.
[0005]
That is, for example, when the viscosity of the matrix resin is too high as compared with the viscosity of the liquid crystal resin, stretching is performed in a state where the elongation of the matrix resin is relatively low, and breakage easily occurs during this stretching. In addition, in the case of the liquid crystal resin composite material obtained by the above-described production method, at the time of extrusion, a shear rate of a predetermined value or more acts, and other fibers such as a glass fiber and a carbon fiber are stretched at a draw ratio of a predetermined value or more. Compared to the reinforcing material, it is difficult to obtain a fiber having a large wire diameter in a fiberized state having predetermined physical properties. Generally, for each fiber, a fiber having a very high tensile strength is obtained. Since it is difficult to do so, it is inherently relatively easy to break or break. Therefore, when the stretching is performed in a state where the elongation of the matrix resin is low, breakage particularly easily occurs.
Also, if the viscosity of the matrix resin is too low compared to the viscosity of the liquid crystal resin, even if the stretching is applied, only the matrix resin is stretched and the tensile force is not transmitted to the liquid crystal resin, and the liquid crystal resin is not sufficiently stretched. It is considered that a good fiber state cannot be obtained.
[0006]
As described above, in order to improve the strength of the liquid crystal resin composite material by optimizing the preparation conditions, it is effective to make the viscosity ratio between the thermoplastic liquid crystal resin and the thermoplastic matrix resin close to unity. In order to extrude both into the resin so that the liquid crystal resin becomes fibrous, the preparation temperature is generally set to a temperature at which the liquid crystal resin is plasticized and melted (liquid crystal transition temperature), usually a temperature at least somewhat higher than that. Is set.
However, at temperatures in this range, there is a considerable difference in viscosity between the liquid crystal resin that plasticizes and melts at this temperature and the matrix resin that has a lower melting temperature (for non-crystalline ones, the lowest moldable temperature). It is not possible to expect much greater improvement in stringiness.
[0007]
For this reason, it is conceivable to set the preparation temperature higher to make the viscosity ratio of the two close to 1, but in this case, the material becomes almost liquid, and conversely, the stringing property is reduced, and There is a problem that the deterioration of the resin (deterioration of physical properties) is caused.
The preparation temperature is set to be excessively high with respect to the melting temperature of the matrix resin (for non-crystalline ones, the minimum moldable temperature). Even if it can be ensured, improvement in the strength of the obtained liquid crystal resin composite cannot be expected.
[0008]
The inventor of the present application has conducted intensive studies with such a problem in mind, and as a result, once maintains a resin (for example, a thermoplastic liquid crystal resin) at a certain temperature (first temperature) and raises its viscosity to the first temperature. If the temperature of the resin is lowered to a second temperature lower than the first temperature to some extent rapidly after maintaining the corresponding viscosity, the viscosity of the resin immediately increases to the viscosity corresponding to the second temperature. Instead, if the temperature rises with a considerable time delay to the temperature change, that is, if the temperature changes rapidly, the temperature may be high (the first temperature) or compared with the temperature regardless of the temperature change. It has been found that the same level of viscosity as that at a temperature close to the target is maintained for a certain period of time, that is, a phenomenon occurs as if it were remembered.
[0009]
Therefore, the present invention focuses on the fact that when the temperature of a resin changes rapidly, the viscosity changes with a considerable time delay with respect to the temperature change, and the thermoplastic liquid crystal resin and the thermoplastic matrix resin When the plasticizer is melted and extruded together with the liquid crystal resin into the matrix resin so that the liquid crystal resin becomes fibrous and stretched, by giving a temperature change to the liquid crystal resin having a high viscosity, without causing deterioration of the matrix resin. The object of the present invention is to minimize the difference in viscosity between the two resins at the time of preparation, thereby improving the strength of the liquid crystal resin composite material.
[0011]
[Means for Solving the Problems]
Therefore, the present invention provides a resin composite material in which a thermoplastic liquid crystal resin having a liquid crystal transition temperature higher than the minimum moldable temperature of the matrix resin is present in a thermoplastic matrix resin in a fibrous state. A method for producing by stretching while extruding with an extruder, wherein the extruder is provided with a rotary screw for kneading the two resins, and on the upstream side in the extruder, the resin material inside is thermoplastic. Liquid crystal transition temperature of liquid crystal resinLess thanA high-temperature portion for plasticizing and melting at the above first temperature is provided, and on the downstream side in the extruder, the resin material inside is higher than the minimum moldable temperature of the thermoplastic matrix resin and lower than the first temperature. A low-temperature portion for plasticizing and melting at the second temperature is provided, and the thermoplastic liquid crystal resin material is charged into the high-temperature portion, while the thermoplastic matrix resin material is charged into the low-temperature portion. It is characterized by being stretched while being extruded.
[0012]
UpOfAs the thermoplastic matrix resin used in the present invention, thermoplastic resins used for various applications can be used, and as typical examples, ABS (acrylonitrile-butadiene-styrene copolymer) resin, polystyrene (PS ) Resins, polycarbonate (PC) resins, polyphenylene oxide (PPO) resins, polyolefin (PO) resins, polyester resins, polyarylate (PAR) resins, polyamide (PA) resins, and mixtures thereof. Are PC / ABS resin (minimum moldable temperature 220 ° C), PC / PBT (polybutylene terephthalate) resin (minimum moldable temperature 230 ° C), m-PPE (modified polyphenylene ether) resin (minimum moldable temperature 220 ° C or 260 ° C) ° C), PA6 resin (minimum moldable temperature 215 ° C), PBT resin (minimum moldable temperature) Temperature 230 ° C), PC resin (minimum moldable temperature 270 ° C), ABS resin (minimum moldable temperature 180 ° C), PP (polypropylene) resin (minimum moldable temperature 176 ° C), PS resin (minimum moldable temperature 170 ℃ or 190 ℃) can be used.
[0013]
On the other hand, a liquid crystal resin can be defined as a resin exhibiting liquid crystallinity in a molten state, and the one used here preferably has a liquid crystal transition temperature higher than the minimum moldable temperature of the matrix resin by about 20 ° C. or more. Specifically, Vectra A950 (trade name) represented by Chemical Formula 1 (liquid crystal transition temperature: 280 to 290 ° C .: manufactured by Polyplastics Co., Ltd.), Econol 6000 (liquid crystal transition temperature: 350 ° C .: manufactured by Sumitomo Chemical Co., Ltd.) ) And Zyder (produced by Nippon Petrochemical Co., Ltd.) such as thermoplastic liquid crystal polyester and thermoplastic liquid crystal polyesteramide.
[0014]
Embedded image

[0017]
Function and Effect of the Invention
Invention of the present applicationAccording toThe extruder has a rotary screw for kneading the two resins,While the high-temperature section is provided on the upstream side of the extruder, the low-temperature section is provided on the downstream side, and the thermoplastic liquid crystal resin material is charged into the high-temperature section. After being plasticized and melted, the temperature will be lowered to the second temperature in the low-temperature part on the downstream side to some extent rapidly, and the viscosity of the liquid crystal resin will be considerably delayed with respect to this temperature change. Although the temperature rises, that is, despite the temperature change, the same level of viscosity as the viscosity at the first temperature or at a temperature relatively close to the first temperature is maintained for a certain period of time, and stored as it is. The matrix resin is plasticized and melted at the second temperature by introducing a thermoplastic matrix resin material into the low temperature section. At this time, the matrix resin and the liquid crystal resin from the upstream side merge. Then, since the two resins are stretched while being extruded, the difference in viscosity during extrusion and stretching is reduced as much as possible, regardless of the change in the viscosity of the two resins with respect to temperature and the difference in the plasticization and melting temperatures. be able to.
[0018]
That is, the high temperature part is the liquid crystal transition temperature of the thermoplastic liquid crystal resin.Less thanBy setting the above first temperature and plasticizing and melting the liquid crystal resin at the first temperature, the liquid crystal resin has the same level of viscosity at the first temperature or at a temperature relatively close to the first temperature. It is prepared by mixing with the matrix resin in the low temperature part while keeping the viscosity. In this way, by setting different plasticizing / melting temperatures on the upstream side (high temperature section) and on the downstream side (low temperature section), it is possible to control the viscosity ratio of both resins, and to improve the threading property (accordingly. And the stretching ratio) can be improved. In this case, the matrix resin is plasticized and melted at a low temperature portion (second temperature), and the temperature is excessively changed with respect to the melting temperature of the matrix resin (for non-crystalline materials, the minimum moldable temperature). Since it is not necessary to set the height higher, the deterioration of the matrix resin can be reliably prevented.
As a result, it is possible to improve the drawability by improving the threading property, and it is also possible to surely avoid the deterioration of the matrix resin and to improve the strength of the liquid crystal resin composite.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a partial vertical cross-sectional explanatory view showing a main part of an extruder according to the present embodiment. As shown in FIG. It extrudes a resin composite material in which a thermoplastic liquid crystal resin having a liquid crystal transition temperature higher than a possible temperature exists in a fibrous state, and has a cylindrical main body 3 fixed on a base 2 and a tip of the main body 3. And a rotary screw 5 housed in the main body 3, and first and second two hoppers 6, 7 are provided in the upper part of the main body 3 in order from the upstream side. ing.
[0020]
In the present embodiment, the resin material inside is plasticized at the first temperature T1 near or above the liquid crystal transition temperature of the thermoplastic liquid crystal resin on the upstream side of the extruder 1, that is, between the hoppers 6 and 7. -While the high-temperature portion 11 to be melted is provided, the first resin temperature is higher than the minimum moldable temperature of the thermoplastic matrix resin at the downstream side of the extruder 1, that is, at the downstream side of the second hopper 7. A low temperature section 12 for plasticizing and melting at a second temperature T2 lower than T1 is provided.
That is, in the high temperature section 11, the set temperature of the heater 13 (first heater) surrounding the body 3 is set to the first temperature T1, and in the low temperature section 12, the heater 14 (first heater) surrounding the body 3 is set. The set temperature of (2 heaters) is set to the second temperature T2.
Incidentally, when the thermoplastic liquid crystal resin is plasticized and melted, the liquid crystal resin is usually heated to a temperature higher than the temperature indicated as its liquid crystal transition temperature, but actually, even at a temperature somewhat lower than this liquid crystal transition temperature. It has been experienced that liquid crystal resins can be plasticized and melted. Therefore, the set temperature T1 of the high temperature section 11 does not necessarily need to be equal to or higher than the liquid crystal transition temperature of the liquid crystal resin, and may be a temperature near the liquid crystal transition temperature and somewhat lower than that.
[0021]
Then, in a state where both the heaters 13 and 14 are turned on and the high temperature section 11 and the low temperature section 12 are set at the set temperatures T1 and T2, first, the first hopper 6 is cut into a predetermined length, for example. The fibrous thermoplastic liquid crystal resin LCP is charged, and the rotating screw 5 is driven at a predetermined rotation speed by a driving device (not shown). Thereby, the thermoplastic liquid crystal resin supplied from the first hopper 6 is plasticized and melted at the first temperature T1 while being kneaded by the rotary screw 5 in the high temperature section 11.
Subsequently, for example, a pellet-shaped thermoplastic matrix resin MP having a minimum moldable temperature lower than the liquid crystal transition temperature of the liquid crystal resin LCP (melting point in the case of crystalline one) is charged into the second hopper 7. The pellets of the matrix resin MP supplied from the second hopper 7 are plasticized and melted at the second temperature T2 while being kneaded by the rotary screw 5 in the low temperature section 12.
[0022]
At this time, the liquid crystal resin LCP plasticized and melted in the high temperature section 11 has reached the low temperature section 12, and its temperature has dropped from the first temperature T1 to the second temperature T2. Then, in the low temperature section 12, the liquid crystal resin LCP and the matrix resin MP are joined and kneaded together and extruded to the nozzle head section 4, and as a result, the liquid crystal resin LCP is oriented in a fibrous form in the matrix resin MP. The strand-shaped liquid crystal resin composite material is extruded from the nozzle hole 4 a of the nozzle head 4.
Although not specifically shown, a cooling tank for cooling the extruded liquid crystal resin composite material, and a liquid crystal resin composite material in an extruded state are stretched to the downstream side outside the extruder 1. A drawing device is provided for drawing out the two resins by extruding them with the extruder 1, thereby forming a thermoplastic matrix resin MP having a liquid crystal transition temperature higher than the minimum moldable temperature of the matrix resin MP. A resin composite material having a predetermined strength in which the plastic liquid crystal resin LCP exists in a fiber state can be obtained.
[0023]
As described above, in the extruder 1 according to the present embodiment, the internal resin material is plasticized at the first temperature T1 (near or above the liquid crystal transition temperature of the thermoplastic liquid crystal resin LCP) in the upstream portion. -While the high-temperature portion 11 to be melted is provided, the resin material inside is plasticized at a second temperature T2 (a temperature higher than the minimum moldable temperature of the thermoplastic matrix resin MP and lower than the first temperature) in a downstream portion thereof. The liquid crystal resin LCP which is supplied from the first hopper 6 and plasticized and melted in the high temperature section 11 is provided with a low temperature section 12 at the downstream low temperature section 12 where the temperature is reduced to the first temperature. The temperature is rapidly lowered from T1 to the second temperature T2 to some extent or more. Then, in the low temperature section 12, the liquid crystal resin LCP and the matrix resin MP supplied from the second hopper 7 are extruded while being kneaded together.
[0024]
The liquid crystal resin LCP, which has a higher viscosity than the matrix resin MP, is temporarily maintained at the first temperature T1 and its viscosity is maintained at a viscosity corresponding to the first temperature T1. In this case, the viscosity of the liquid crystal resin LCP does not immediately rise to the viscosity corresponding to the second temperature T2, as described above. The temperature rises with a considerable time delay with respect to the temperature change. That is, despite this temperature change, the viscosity at the same level as the viscosity at a high temperature (first temperature T1) or at a temperature relatively close to the temperature is obtained. The liquid crystal resin LCP and the matrix resin MP can have a viscosity difference by appropriately setting the first temperature T1 and the second temperature T2 because the liquid crystal resin LCP is held (or stored) for some time. While maintaining small, can be stretched while extruding the two resins, it is possible to obtain a high strength liquid crystal polymer composite material.
[0025]
Next, an experimental example will be described in which the relationship between the viscosity ratio of both resins during preparation and the strength of the obtained liquid crystal resin composite material was examined.
FIG. 2 shows a case where a thermoplastic liquid crystal resin and a thermoplastic matrix resin are prepared at the same temperature, that is, using a conventional extruder in which a material input hopper is provided only at one location in the upstream portion, 5 is a graph showing the results of examining the relationship between the preparation temperature and the viscosity ratio when preparing and extruding at the same temperature.
Similarly, FIG. 3 shows the relationship between the preparation temperature and the tensile strength of the obtained liquid crystal resin composite when both resin materials were prepared and extruded at the same temperature using a conventional extruder. It is a graph which shows the result of having investigated the relationship.
[0026]
As can be seen from the graphs of FIGS. 2 and 3, the viscosity ratio between the thermoplastic liquid crystal resin and the thermoplastic matrix resin is set to rise when the preparation temperature is lower than a certain value (about 300 ° C .; see FIG. 2). However, when prepared at a temperature at which this viscosity ratio is close to 1 (around 300 ° C.), the strength of the resulting liquid crystal resin composite material becomes almost maximum (see FIG. 3).
In addition, in this material system, when the temperature exceeds 310 ° C., the viscosity as a whole decreases, so that the stringiness deteriorates. For this reason, when the stretching ratio is reduced and stretching is performed, so-called waving occurs in the completed composite material even if stretching itself is possible, or the temperature at which plasticization and melting are lower than that of the liquid crystal resin is low. Problems such as deterioration of the matrix resin are likely to occur, and the strength of the composite material has begun to decrease.
[0027]
The thermoplastic liquid crystal resin and the thermoplastic matrix resin used in the experiments shown in FIGS. 2 and 3 are as follows.
・ Thermoplastic liquid crystal resin
-Material name: Aromatic polyester resin
-Trade name: VECTRA A950 (manufactured by Polyplastics Co., Ltd.)
-Liquid crystal transition temperature: 280-290 ° C
・ Thermoplastic matrix resin
-Material name: Polypropylene (PP) resin
-Trade name: Noblen H501 (manufactured by Sumitomo Chemical Co., Ltd.)
-Melting point: 165 to 170C (normal molding temperature: 190C or higher)
[0028]
Next, regarding the thermoplastic liquid crystal resin, an experimental result obtained by examining a relationship between a time lapse and a viscosity change of the liquid crystal resin when a temperature change (change from a high temperature to a low temperature) is given to the liquid crystal resin is shown in the graph of FIG. This will be described with reference to FIG.
In this experiment, Vectra A950 (manufactured by Polyplastics Co., Ltd.) was used as the thermoplastic liquid crystal resin.
The experimental apparatus, setting conditions, and experimental method used in this experiment were as follows.
・ Experimental equipment: Capillary rheometer
・ Die diameter: 1.0mm
-Shear rate: 1800 / s
-Experimental method: The temperature of the thermoplastic liquid crystal resin is raised from the initial temperature (250 ° C) at a constant temperature interval (10 ° C), and when the temperature reaches a certain predetermined temperature (first temperature), the temperature is maintained for a certain time (about 10 minutes). Stabilize. Thereafter, when the barrel temperature was started to be lowered to the second temperature (270 ° C.), a change with time in the viscosity of the liquid crystal resin, a time required until the barrel temperature actually decreased to the second temperature, and the like were measured.
[0029]
In the graph of FIG. 4, a solid line curve A indicates a viscosity change characteristic when the temperature of the liquid crystal resin is raised at a constant temperature interval (10 ° C.) from the initial temperature (250 ° C.). The measured values of the viscosity at each temperature are shown in column I of Table 1.
The white circles (○) groups C0, C1, C2, and C3 plotted on the right side of the points of 270 ° C., 300 ° C., 330 ° C., and 340 ° C. in the solid line curve A are constant at each of the temperatures (first temperature). The graph shows the change over time in the viscosity of the liquid crystal resin when the liquid crystal resin is stabilized for a period of time (about 10 minutes). The measured value of the viscosity after the holding for a certain period of time is shown in column II of Table 1 above. Incidentally, in this case, at a temperature of 270 ° C., the viscosity (420 Pa · s) after holding for a certain period of time is considerably high, which indicates that the liquid crystal resin is at least not sufficiently melted.
[0030]
[Table 1]

[0031]
Further, in the graph of FIG. 4, the dashed curves B1, B2, and B3 are obtained by maintaining the barrel temperature for a predetermined time (about 10 minutes) at each predetermined temperature (first temperature) for about 10 minutes, and then setting the barrel temperature to the second temperature (first temperature). 270.degree. C.), the change over time in the viscosity of the liquid crystal resin when the temperature starts to fall to 270.degree. C., respectively, and points P1, P2, and P3 on each curve indicate that the barrel temperature is actually at the second temperature (270.degree. C.). ). In addition, the measured value of the viscosity corresponding to each of the dashed curves B1, B2, and B3 is shown in column III of Table 1, and the points P1, P2, and P3 are shown in parentheses of the measured values in column III of Table 1. Each of them is shown with a symbol.
Further, in the graph of FIG. 4, an alternate long and short dash line D is a reference line representing a viscosity corresponding to a typical temperature near the liquid crystal transition temperature (280 to 290 ° C.) of the liquid crystal resin.
[0032]
From the graph of FIG. 4 and the data of Table 1, the liquid crystal resin maintains the viscosity at a high temperature for a certain period of time even when the barrel temperature falls to the second temperature (270 ° C.), and particularly at a temperature near the liquid crystal transition temperature. Is maintained for the following period according to the level of the first temperature.
・ When the first temperature is 300 ° C: about 10 minutes
・ When the first temperature is 330 ° C: about 35 minutes
・ When the first temperature is 340 ° C: about 25 minutes
Therefore, according to this data example, when the first temperature is set to 330 ° C., the viscosity of the liquid crystal resin at a temperature near the liquid crystal transition temperature is best stored.
[0033]
On the other hand, FIG. 5 separately shows the relationship between the temperature and the viscosity of the thermoplastic liquid crystal resin (Vectra A950: manufactured by Polyplastics Co., Ltd.) and the thermoplastic matrix resin (see below) used in the present embodiment. 9 is a graph showing an experimental result. In this graph, a curve H indicates a change in viscosity of the liquid crystal resin, and curves J and K indicate a change in viscosity of the matrix resin.
In the experiment shown in FIG. 5, the aforementioned Noblen H501 (manufactured by Sumitomo Chemical Co., Ltd.) was used as the thermoplastic matrix resin.
[0034]
From the graph of FIG. 5, it can be seen that the liquid crystal resin needs to be in the vicinity of its liquid crystal transition temperature (280 to 290 ° C.) in order to make the viscosity ratio between the liquid crystal resin and the matrix resin approximately 1 while maintaining a good fibrous state of the liquid crystal resin. It is understood that the matrix resin may be plasticized and melted at a temperature in the range of about 220 to 270 ° C. so that the viscosity becomes the same level as this viscosity.
[0035]
Further, an embodiment of the present invention in which a thermoplastic liquid crystal resin and a thermoplastic matrix resin are plasticized, melted, extruded, and stretched at different temperatures using an extruder 1 (see FIG. 1) according to an embodiment of the present invention. A strength test for measuring the tensile strength of the obtained liquid crystal resin composite material was performed on a comparative example in which the two resins were plasticized and melted at the same temperature and extruded and stretched using the conventional extruder.
The materials, equipment, test conditions, and the like used in this test were as follows.
a) Materials
-Thermoplastic liquid crystal resin: VECTRA A950 (1.4 g / cm density)³)
-Thermoplastic matrix resin: Noblen H501 (density 0.9 g / cm³)
These material resins were mixed at a ratio of 60% by weight of liquid crystal resin and 40% by weight of matrix resin.
b) Equipment
A well-known twin-screw kneader was used.
[0036]
c) Extrusion conditions
・ Capillary diameter: 2mm (diameter) x 20mm
-Extrusion amount: about 6.1 kg / hr
-Shear rate: 1800 / sec.
d) Plasticization / melting temperature
-Embodiment of the present invention-High temperature section (upstream side / liquid crystal resin): 330 ° C
-Low temperature section (downstream side / matrix resin): 270 ° C
・ Comparative example: 330 ° C (only upstream side / same temperature for both resins)
e) Under the above conditions, samples were prepared with various draw ratios, and the tensile strength was measured for each sample.
[0037]
The test results were as shown in the graph of FIG.
As can be seen from this graph, in both the embodiment of the present invention and the comparative example, as the stretching ratio is increased, the tensile strength is improved.
It was also confirmed that the embodiment of the present invention (maximum stretching ratio 17) can set a higher stretching ratio than the comparative example (maximum stretching ratio 13). This is because, in the embodiment of the present invention, the liquid crystal resin is plasticized and melted at a high temperature portion (first temperature), and the liquid crystal resin has the same level of viscosity at the first temperature or at a temperature relatively close to the first temperature. Is prepared by mixing with the matrix resin in the low temperature part (second temperature) while keeping the viscosity of the resin, the viscosity ratio of both resins can be controlled, and the embodiment of the present invention is better than the comparative example. This is considered to be because the difference in viscosity between the liquid crystal resin and the matrix resin can be reduced (that is, the viscosity ratio is closer to 1).
Further, it was confirmed that the tensile strength of the embodiment of the present invention was significantly higher than that of the comparative example even when the stretching ratio was the same. This is because, in the embodiment of the present invention, the plasticizing and melting temperatures of the liquid crystal resin and the matrix resin are made different, and the matrix resin is plasticized and melted at a low temperature part, so that the deterioration of the matrix resin is reliably prevented. This is probably due to what can be done.
[0038]
As described above, according to the present embodiment, the high temperature section 11 is provided on the upstream side of the extruder 1, the low temperature section 12 is provided on the downstream side, and the thermoplastic liquid crystal resin material LCP is provided on the high temperature section 11. Since the liquid crystal resin LCP is plasticized and melted at the first temperature T1, the temperature of the liquid crystal resin LCP is lowered to the second temperature T2 in the downstream low-temperature portion 12 to the second temperature T2 to some extent. Thus, the viscosity of the liquid crystal resin LCP increases with a considerable time delay with respect to this temperature change, that is, despite the temperature change, the first temperature T1 or a temperature relatively close to the first temperature T1. The viscosity at the same level as the viscosity at is maintained for some time, so to speak. Then, by feeding the thermoplastic matrix resin material MP to the low temperature section 12, the matrix resin MP is plasticized and melted at the second temperature T2. At this time, the matrix resin MP and the liquid crystal resin LCP from the upstream side merge. Then, since the two resins LCP and MP are stretched while being extruded, regardless of the change characteristic of the viscosity of the two resins LCP and MP with respect to the temperature and the difference of the plasticization / melting temperature, the extrusion and the stretching are performed. The difference in viscosity can be minimized.
[0039]
That is, the high-temperature portion 11 is set to a first temperature T1 near or higher than the liquid crystal transition temperature of the thermoplastic liquid crystal resin LCP, and the liquid crystal resin LCP is plasticized and melted at the first temperature T1, thereby forming the liquid crystal resin LCP. Is prepared by mixing with the matrix resin in the low-temperature section 12 while storing the same level of viscosity as the viscosity at the first temperature T1 or a temperature relatively close to the first temperature T1. In this way, by setting different plasticizing / melting temperatures on the upstream side (high-temperature section 11) and on the downstream side (low-temperature section 12), it is possible to control the viscosity ratio of both resins LCP and MP. It is possible to improve the pulling property (therefore, the stretching ratio). In this case, the matrix resin MP is plasticized and melted in the low temperature portion 12 (second temperature), and the temperature is set to the melting temperature of the matrix resin (for non-crystalline materials, the minimum moldable temperature). Since it is not necessary to set an excessively high value, it is possible to reliably prevent the matrix resin MP from deteriorating.
As a result, it becomes possible to improve the stringing property and increase the draw ratio, and it is also possible to reliably avoid the deterioration of the matrix resin MP and to improve the strength of the liquid crystal resin composite. .
The method according to the present invention is applied to a case of a combination of material resins having a large difference between a liquid crystal transition temperature of a thermoplastic liquid crystal resin and a melting temperature of a thermoplastic matrix resin (for non-crystalline materials, a minimum moldable temperature). It is particularly effective for preventing deterioration of the matrix resin.
[0040]
In the above embodiment, Noblen H501 (polypropylene (PP) resin) was used as the thermoplastic matrix resin combined with the thermoplastic liquid crystal resin Vectra A950 (aromatic polyester resin). It is possible to use various other matrix resins as shown.
・ PP (polypropylene) resin: Noblen D501 etc. (manufactured by Sumitomo Chemical Co., Ltd.)
ABS (acrylonitrile-butadiene-styrene copolymer) resin: Clastic MH, etc. (manufactured by Sumitomo Dow)
・ PC (polycarbonate) resin: Lexan 141 etc. (manufactured by Nippon GE Plastics Co., Ltd.)
・ PC / ABS resin: Techniace T105 etc. (manufactured by Sumitomo Dow)
・ PA (polyamide) resin: Nylon 1013B, 1030B, 1018I, etc. (Ube Industries, Ltd.)
・ PPE / PA6 (polyphenylene ether / nylon 6) resin: Noryl GTX6006 etc. (manufactured by Nippon GE Plastics Co., Ltd.)
・ PS (polystyrene) resin: S-bright 9M etc. (manufactured by Showa Denko KK)
-PBT (polybutylene terephthalate): 1401-X07 etc. (manufactured by Toray Industries, Inc.)
・ Modified PPE resin: Noryl PX2623 etc. (manufactured by Nippon GE Plastics Co., Ltd.)
・ PC / PBT resin: Zenoi 1101, etc. (manufactured by Nippon GE Plastics Co., Ltd.)
[0041]
It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that various improvements or design changes can be made without departing from the scope of the invention.
[Brief description of the drawings]
FIG. 1 is a partial longitudinal sectional explanatory view showing a main part of an extruder according to an embodiment of the present invention.
FIG. 2 is a graph showing an example of a relationship between a preparation temperature and a viscosity ratio when a thermoplastic liquid crystal resin and a thermoplastic matrix resin are prepared at the same temperature.
FIG. 3 is a graph showing an example of a relationship between a preparation temperature and a tensile strength when a thermoplastic liquid crystal resin and a thermoplastic matrix resin are prepared at the same temperature.
FIG. 4 is a graph showing an example of the relationship between the passage of time and the change in viscosity when a temperature change is applied to a thermoplastic liquid crystal resin.
FIG. 5 is a graph showing an example of a relationship between temperature and viscosity of a thermoplastic liquid crystal resin and a thermoplastic matrix resin.
FIG. 6 is a graph showing a comparison between strength characteristics of a liquid crystal resin composite obtained by the extruder and a liquid crystal resin composite obtained by a conventional method.
[Explanation of symbols]
1. Extruder
11 ... High temperature part
12 ... Low temperature part
LCP: Thermoplastic liquid crystal resin
MP: thermoplastic matrix resin
T1: First temperature
T2: second temperature

Claims (1)

In a thermoplastic matrix resin, a resin composite material in which a thermoplastic liquid crystal resin having a liquid crystal transition temperature higher than the minimum moldable temperature of the matrix resin is present in a fibrous state is stretched while extruding both resins with an extruder. A manufacturing method for manufacturing by
The extruder has a rotating screw kneading the two resins, the upstream side in the extruder, plasticized, the interior of the resin material at a first temperature on the liquid crystal transition temperature degrees or of the thermoplastic liquid crystal polymer A high-temperature portion to be melted is provided, and on the downstream side in the extruder, the resin material inside is plasticized and melted at a second temperature higher than the minimum moldable temperature of the thermoplastic matrix resin and lower than the first temperature. A low-temperature section is provided, and while the thermoplastic liquid crystal resin material is charged into the high-temperature section, the thermoplastic matrix resin material is charged into the low-temperature section, and then the resin is stretched while being extruded. Manufacturing method of resin composite material.

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