JPWO2007043701A1

JPWO2007043701A1 - Liquid crystalline resin composition for injection molding

Info

Publication number: JPWO2007043701A1
Application number: JP2007540230A
Authority: JP
Inventors: 淑子熊井; 俊雄塩飽; 渡辺　一史; 一史渡辺
Original assignee: Polyplastics Co Ltd
Current assignee: Polyplastics Co Ltd
Priority date: 2005-10-13
Filing date: 2006-10-12
Publication date: 2009-04-23
Anticipated expiration: 2026-10-12
Also published as: CN101305056A; JP5107048B2; WO2007043701A1; CN101305056B

Abstract

本発明は、液晶性樹脂が有する機械的物性、特に流動性、弾性率を保持し、面衝撃強度が改善された液晶性樹脂組成物を提供する。詳しくは、（Ａ）液晶性樹脂あるいは（Ａ）液晶性樹脂と（Ｃ）特定の無機充填剤からなる樹脂組成物に対して、（Ｂ）成分として、（１Ｂ）α−オレフィンとα，β−不飽和酸のグリシジルエステルよりなるオレフィン系共重合体をグリシジルエステル成分が０．２〜０．７重量％となるように、または（２Ｂ）スチレン類とα，β−不飽和酸のグリシジルエステルよりなるスチレン系共重合体をグリシジルエステル成分が０．１〜１．１重量％となるように溶融混練して得る。The present invention provides a liquid crystalline resin composition having improved surface impact strength while maintaining the mechanical properties, particularly fluidity and elastic modulus of the liquid crystalline resin. Specifically, for the resin composition comprising (A) liquid crystalline resin or (A) liquid crystalline resin and (C) a specific inorganic filler, (1B) α-olefin and α, β as component (B) -An olefin copolymer comprising a glycidyl ester of an unsaturated acid such that the glycidyl ester component is 0.2 to 0.7 wt%, or (2B) a glycidyl ester of a styrene and an α, β-unsaturated acid. A styrene-based copolymer is melt-kneaded so that the glycidyl ester component is 0.1 to 1.1% by weight.

Description

本発明は、電気・電子機器部品、携帯電話の筺体、自動車外板等として有用な優れた面衝撃強度を有する新規な射出成形用液晶性樹脂組成物に関する。 The present invention relates to a novel liquid crystalline resin composition for injection molding having excellent surface impact strength, which is useful as an electric / electronic device part, a mobile phone casing, an automobile outer plate and the like.

液晶性ポリエステル樹脂に代表される液晶性樹脂は、優れた機械的強度、耐熱性、耐薬品性、電気的性質等をバランス良く有するため高機能エンジニアリングプラスチックとして広く利用されている。しかし、液晶性樹脂は、成形時の分子配向により、シャルピー試験においては高い衝撃強度を示すが、落錘衝撃等の面衝撃強度は低いことが知られている。
これまでに、液晶性樹脂の面衝撃強度を改良するためにはオレフィン系共重合体を配合する技術が各種提案されている。
例えば、ＪＰ−Ａ８−１２８６２には、液晶性ポリエステル樹脂の面衝撃強度を改良するため、エチレンと炭素数３以上のα−オレフィンからなるオレフィン系共重合体に対し０．０１〜１０重量％の不飽和カルボン酸またはその誘導体をグラフトして得た変性エチレン系共重合体、またはエチレン、炭素数３以上のα−オレフィン及び非共役ジエンからなる共重合体に対し０．０１〜１０重量％の不飽和カルボン酸またはその誘導体をグラフトして得た変性エチレン系共重合体を配合した液晶性ポリエステル樹脂組成物が開示されている。
同様に、ＪＰ−Ａ７−３１６４０２には、α−オレフィン類とα，β−不飽和酸のグリシジルエステルとからなるオレフィン系共重合体を配合した液晶性ポリエステル樹脂組成物が開示されている。
しかし、何れの組成物も液晶性ポリエステル樹脂の面衝撃強度を十分に改善するものではなく、また反応性オレフィン系共重合体の過度の添加により本来液晶性ポリエステル樹脂の持つ流動性、弾性率が損なわれ、薄肉射出成形品へは使用が困難である。Liquid crystalline resins typified by liquid crystalline polyester resins are widely used as highly functional engineering plastics because they have excellent mechanical strength, heat resistance, chemical resistance, electrical properties and the like in a well-balanced manner. However, liquid crystalline resins are known to exhibit high impact strength in the Charpy test due to molecular orientation during molding, but low surface impact strength such as falling weight impact.
So far, various techniques for blending an olefin copolymer have been proposed in order to improve the surface impact strength of a liquid crystalline resin.
For example, JP-A 8-12862 includes 0.01 to 10% by weight based on an olefin copolymer composed of ethylene and an α-olefin having 3 or more carbon atoms in order to improve the surface impact strength of the liquid crystalline polyester resin. 0.01 to 10% by weight based on a modified ethylene copolymer obtained by grafting an unsaturated carboxylic acid or derivative thereof, or a copolymer comprising ethylene, an α-olefin having 3 or more carbon atoms and a non-conjugated diene A liquid crystalline polyester resin composition containing a modified ethylene copolymer obtained by grafting an unsaturated carboxylic acid or derivative thereof is disclosed.
Similarly, JP-A 7-316402 discloses a liquid crystalline polyester resin composition in which an olefin copolymer composed of an α-olefin and a glycidyl ester of an α, β-unsaturated acid is blended.
However, none of the compositions sufficiently improves the surface impact strength of the liquid crystalline polyester resin, and the liquidity polyester resin inherently has fluidity and elastic modulus due to excessive addition of the reactive olefin copolymer. It is damaged and difficult to use for thin-walled injection molded products.

本発明は、液晶性樹脂が有する機械的物性、特に流動性、弾性率を保持し、面衝撃強度が改善された液晶性樹脂組成物の提供する。
本発明者らは鋭意検討を重ねた結果、液晶性樹脂（Ａ）に、特定のオレフィン系共重合体（１Ｂ）または特定のスチレン系共重合体（２Ｂ）であるＢ成分を、場合により特定の無機充填剤（Ｃ）を特定量配合し、溶融混練した場合にのみ、優れた面衝撃強度と流動性、弾性率を満足する樹脂組成物が得られることを見出し、本発明を完成するに至った。
本発明は、（Ａ）液晶性樹脂に対して、（Ｂ）成分として、（１Ｂ）α−オレフィンとα，β−不飽和酸のグリシジルエステルよりなるオレフィン系共重合体をグリシジルエステル成分が０．２〜０．７重量％となるように、または（２Ｂ）スチレン類４０〜９８重量％、α，β−不飽和酸のグリシジルエステル２０〜２重量％、他のビニルモノマー０〜４０重量％よりなるスチレン系共重合体をグリシジルエステル成分が０．１〜１．１重量％となるように、溶融混練してなることを特徴とする射出成形用液晶性樹脂組成物である。
さらに本発明は、（Ａ）液晶性樹脂１００重量部及び（Ｃ）平均繊維径１５μｍ以下、平均繊維長１００μｍ以下の繊維状充填剤、最大粒子径２０μｍ以下、アスペクト比３〜８の板状充填剤、平均粒子径０．２〜２μｍの粉粒状充填剤から選ばれる１種又は２種以上の無機充填剤１〜１００重量部からなる樹脂組成物に対して、（Ｂ）成分として、（１Ｂ）α−オレフィンとα，β−不飽和酸のグリシジルエステルよりなるオレフィン系共重合体をグリシジルエステル成分が０．２〜０．７重量％となるように、または、（２Ｂ）スチレン類４０〜９８重量％、α，β−不飽和酸のグリシジルエステル２０〜２重量％、他のビニルモノマー０〜４０重量％よりなるスチレン系共重合体をグリシジルエステル成分が０．１〜１．１重量％となるように、溶融混練してなることを特徴とする射出成形用液晶性樹脂組成物を提供する。
また、本発明は、上記液晶性樹脂組成物を射出成形することによって得られる肉厚２ｍｍ以下の射出成形品と上記液晶性樹脂組成物を射出成形することによって得られる筺体を提供する。
発明の詳細な説明
本発明の射出成形用液晶性樹脂組成物は、従来の液晶性樹脂組成物に比べて飛躍的に面衝撃強度が向上し、且つ剛性、流動性に優れるため、携帯電話、デジタルカメラ等の外装部品等、各種分野で使用可能な射出成形品を提供することができる。
以下、本発明組成物の構成成分について詳しく説明する。本発明に使用する液晶性樹脂（Ａ）は溶融時に光学的異方性を示すネマチック液晶性樹脂であり、本発明において耐熱性と易加工性を併せ持つ上で不可欠な要素である。溶融異方性の性質は直交偏光子を利用した慣用の偏光検査方法により確認することができる。具体的にはＬｅｉｔｚ偏光顕微鏡を使用しＬｅｉｔｚホットステージにのせた試料を溶融し、窒素雰囲気下で約４０倍の倍率で観察することにより確認できる。上記光学的に異方性のポリマーは直交偏光子間に挿入したとき溶融静止液状態であっても偏光は透過する。
本発明に用いられる液晶性樹脂（Ａ）は、好ましくは下記一般式（１）よりなる芳香族ヒドロキシカルボン酸基を少なくとも３０モル％以上含有する芳香族ポリエステルであり、他の一般式（２）で示すジカルボン酸基と一般式（３）で示すジオールからなる繰り返し単位を夫々３５モル％以下で含有した芳香族ポリエテスルも含まれる。

本発明に好ましく使用される液晶性ポリエステルの主たる繰り返し単位を構成する（１）式の−Ａｒ_１−はフェニレン基及び／又はナフタレン基より成り、これらの芳香族ヒドロキシカルボン酸又はそのエステル形成性化合物の重縮合によって得られる。かかる芳香族ヒドロキシカルボン酸化合物の例を示せば、４−ヒドロキシ安息香酸、６−ヒドロキシ−２−ナフトエ酸、７−ヒドロキシ−２−ナフトエ酸、４−（４−ヒドロキシフェニル）安息香酸の如き芳香族ヒドロキシカルボン酸又はそのエステル形成性化合物が挙げられ、１種又は２種以上の混合物であってもよい。特に（１）式構成単位としては４−ヒドロキシ安息香酸基を主とし、一部ヒドロキシナフトエ酸基を含むものが好ましい。特に使用するポリエステルの構成単位として後述の（２）式構成単位が不存在、又は極めて少ない場合には（１）式構成単位が上記２種よりなることが特に成形性の点で好ましい。
次に本発明に好ましく使用されるポリエステル（Ａ）を構成する（２）式の−Ａｒ_２−はフェニレン基、ナフタレン基、ジフェニレン基であり、又液晶性を保持する範囲で脂肪族基であってもよい。又、（３）式の−Ｒ−はフェニレン基、ナフタレン基、ビフェニレン基等であり、炭素数２〜８の脂肪族基であってもよい。（２）式及び（３）式構成単位は、原料としてジカルボン酸（ＨＯＯＣ−Ａｒ_２−ＣＯＯＨ）又はそのエステル形成性化合物及びジオール（ＨＯ−Ｒ−ＯＨ）より形成され、かかる酸成分とジオール成分を前記芳香族ヒドロキシカルボン酸又はそのエステル形成性化合物と共に重縮合反応することにより導入される。（２）式単位を構成するためのジカルボン酸成分としてはテレフタル酸、２，６−ナフタレンジカルボン酸、イソフタル酸、２，７−ナフタレンジカルボン酸、４，４’−ジフェニルカルボン酸等、公知の芳香族ジカルボン酸又はそのエステル形成性化合物が挙げられる。又、（３）式単位を構成するためのジオールとしては、ハイドロキノン、核置換ハイドロキノン、４，４’−ビフェノール、２，６−ジヒドロキシナフタレン、ビスフェノールＡ等の公知の芳香族ジオール、或いは脂肪族ジオール、例えばエチレングリコール、シクロヘキサンジメタノールから成る１種又は２種以上を用いることが出来る。
本発明に好ましく使用される液晶性ポリエステル（Ａ）は（１）式構成単位が少なくとも３０モル％以上、（２）式及び（３）式単位が夫々３５モル％以下であり、好ましくは（１）式４０％以上、（２）式及び（３）式単位が夫々３０％以下、更に好ましくは（１）式５０％以上、（２）式及び（３）式単位が夫々２５％以下である。尚、本発明に使用される液晶性樹脂（Ａ）は更に上記（１）式及び（２）、（３）式以外に、溶融時に液晶性を示す範囲内でエーテル結合やアミド結合を持つコモノマー成分を導入してもよく、又、液晶性を保持する範囲内で、ペンタエリスリトール、トリメリット酸、トリメシン酸、４−ヒドロキシイソフタル酸の様な多官能性エステル形成モノマーや、スルホイソフタル酸ナトリウム、パラヒドロキシエチルフェニルスルホン酸ナトリウムのようなイオン性基を持つエステル形成性モノマーを導入したものでもよい。特に好ましい液晶性ポリエステル樹脂（Ａ）としては、４−ヒドロキシ安息香酸、６−ヒドロキシ−２−ナフトエ酸から成る共重合芳香族ポリエステル、及び更にこれ以外にテレフタル酸、イソフタル酸よりなる酸成分と、ハイドロキノン、４，４’−ビフェノール、エチレングリコールよりなるジオール成分との組合せモノマーを共重合して得られる芳香族コポリエステルである。
本発明に用いられる液晶性熱可塑性樹脂（Ａ）の調製は、上記のモノマー化合物から直接重合法やエステル交換法を用いて公知の方法で行うことが出来るが、通常は溶融重合法やスラリー重合法等が用いられる。エステル形成能を有する上記化合物類はそのままの形で重合に用いても良く、又、重合の前段階で前駆体から該エステル形成能を有する誘導体に変性されたものでもよい。これらの重合に際しては種々の触媒の使用が可能であり、代表的なものはジアルキル錫酸化物、ジアリール錫酸化物、２酸化チタン、アルコキシチタンけい酸塩類、チタンアルコラート類、カルボン酸のアルカリ及びアルカリ土類金属塩類、ＢＦ_３の如きルイス酸塩等があげられる。触媒の使用量は一般にはモノマーの全重量に基いて約０．００１乃至１重量％、特に約０．０１乃至０．２重量％が好ましい。これらの重合方法により製造されたポリマーは更に必要があれば、減圧又は不活性ガス中で加熱する固相重合により分子量の増加を図ることができる。本発明で使用する液晶性樹脂（Ａ）の溶融粘度は特に限定する必要はなく、射出成形可能なものであれば何れにても良い。一般には成形温度での溶融粘度が剪断速度１０００ｓｅｃ^−１で１０ＭＰａ以上６００ＭＰａ以下のものが使用可能である。しかし、それ自体あまり高粘度のものは流動性が非常に悪化するため好ましくない。尚、上記液晶性樹脂（Ａ）は２種以上の液晶性樹脂の混合物であっても良い。
次に、本発明における（Ｂ）成分を説明する。
本発明における（１Ｂ）成分のオレフィン系共重合体は、基体液晶性樹脂（Ａ）に配合して面衝撃強度を著しく改善する効果を奏するものである。かかる（１Ｂ）成分のオレフィン系共重合体とは、α−オレフィンとα，β−不飽和酸のグリシジルエステルよりなるものである。
かかる（１Ｂ）成分のα−オレフィンとしては、具体的にはエチレン、プロピレン、ブテン等が挙げられるが、中でもエチレンが好ましく用いられる。また、（１Ｂ）成分のもう一つの構成成分であるα，β−不飽和酸のグリシジルエステルは下記一般式（４）で示されるものである。

（式中、Ｒ’は水素又は低級アルキル基である。）
α，β−不飽和酸のグリシジルエステルユニットは、例えばアクリル酸グリシジルエステル、メタクリル酸グリシジルエステル、エタクリル酸グリシジルエステル、イタコン酸グリシジルエステル等であるが、特にメタクリル酸グリシジルエステルが好ましい。
本発明で用いる（１Ｂ）オレフィン系共重合体は、本発明を損なわない範囲で上記２成分以外に第３成分としてアクリロニトリル、アクリル酸エステル、メタクリル酸エステル、α−メチルスチレン、無水マレイン酸等のオレフィン系不飽和エステルの１種又は２種以上を、上記２成分１００重量部に対し０〜４８重量部含有しても良い。
本発明の特徴の一つは、組成物中の（１Ｂ）オレフィン系共重合体のグリシジルエステル成分比率を特定範囲に規制したことにある。即ち、総添加グリシジルエステルが０．２重量％未満あるいは０．７重量％を超える場合、面衝撃強度の改善効果が得られないため、（１Ｂ）成分のオレフィン系共重合体の配合量は総添加グリシジルエステル重量％にして０．２〜０．７重量％に制限される。最も好ましくは０．２〜０．６重量％である。
また、（１Ｂ）成分のオレフィン系共重合体中のα，β−不飽和酸のグリシジルエステル含有量が低すぎる場合、面衝撃強度の改善のためには（１Ｂ）成分を多量に添加する必要が生じ、剛性（弾性率）が低下する。そのため、（１Ｂ）成分のオレフィン系共重合体中のα，β−不飽和酸のグリシジルエステル含有量は２重量％以上を必要とする。
一方、（１Ｂ）成分のオレフィン系共重合体中のα，β−不飽和酸のグリシジルエステル含有量が１３重量％を超えると面衝撃強度の改善効果が低下する。
そのため、（１Ｂ）成分のオレフィン系共重合体中のα，β−不飽和酸のグリシジルエステル含有量は２〜１３重量％であり、α−オレフィン８７〜９８重量％、α，β−不飽和酸のグリシジルエステル１３〜２重量％の比率のオレフィン系共重合体が好ましい。
組成物中の総添加グリシジルエステルを０．２〜０．７重量％にするためには、例えば、（Ａ）液晶性樹脂９７．５〜９２重量％に対し、（１Ｂ）α−オレフィン８７〜９８重量％、α，β−不飽和酸のグリシジルエステル１３〜２重量％よりなるオレフィン系共重合体２．５〜８重量％の比率が好ましい。
本発明の（１Ｂ）成分であるオレフィン系共重合体は、各成分のモノマーをラジカル重合触媒を用いて通常のラジカル重合法により容易に調製することができる。より具体的には、通常、α−オレフィンとα，β−不飽和酸のグリシジルエステルをラジカル発生剤の存在下、５００〜４０００気圧、１００〜３００℃で適当な溶媒や連鎖移動剤の存在下または不存在下に共重合させる方法により製造できる。また、α−オレフィンとα，β−不飽和酸のグリシジルエステル及びラジカル発生剤を混合し、押出機の中で溶融グラフト共重合させる方法によっても製造できる。
また、本発明の射出成形用液晶性樹脂組成物に、成形品の機械的物性、特に強度と剛性を付与するには、特定の繊維状充填剤、板状充填剤、粉粒状充填剤を併用する必要があり、
（Ａ）液晶性樹脂１００重量部及び
（Ｃ）平均繊維径１５μｍ以下、平均繊維長１００μｍ以下の繊維状充填剤、最大粒子径２０μｍ以下、アスペクト比３〜８の板状充填剤、平均粒子径０．２〜２μｍの粉粒状充填剤から選ばれる１種又は２種以上の無機充填剤１〜１００重量部からなる樹脂組成物に対して、
（１Ｂ）α−オレフィンとα，β−不飽和酸のグリシジルエステルよりなるオレフィン系共重合体をグリシジルエステル成分が０．２〜０．７重量％となるように溶融混練する必要がある。
即ち、（Ａ）液晶性樹脂及び（Ｃ）無機充填剤からなる樹脂組成物に対し、総添加グリシジルエステルが０．２重量％未満あるいは０．７重量％を超える場合、面衝撃強度の改善効果が得られないため、（１Ｂ）成分のオレフィン系共重合体の配合量は、（Ａ）液晶性樹脂及び（Ｃ）無機充填剤からなる樹脂組成物に対し総添加グリシジルエステル重量％にして０．２〜０．７重量％、好ましくは０．２〜０．６重量％である。
上記記載した通りの理由により、（Ａ）液晶性樹脂及び（Ｃ）無機充填剤からなる樹脂組成物に対し、（１Ｂ）α−オレフィン８７〜９８重量％、α，β−不飽和酸のグリシジルエステル１３〜２重量％よりなるオレフィン系共重合体を２．５〜８重量％の比率で配合するのが好ましい。
上記記載した通り、（１Ｂ）α−オレフィンとα，β−不飽和酸のグリシジルエステルよりなるオレフィン系共重合体は、第３成分を含有しても良いことは言うまでもない。
次に、本発明における（２Ｂ）成分のスチレン系共重合体は、基体液晶性樹脂（Ａ）に配合して面衝撃強度を著しく改善する効果を奏するものである。かかる（２Ｂ）成分のスチレン系共重合体とは、スチレン類４０〜９８重量％とα，β−不飽和酸のグリシジルエステル２０〜２重量％よりなるものである。
かかる（２Ｂ）成分の構成成分であるスチレン類としては、スチレン、α−メチルスチレン、ブロム化スチレン、ジビニルベンゼン等が挙げられるが、スチレンが好ましく用いられる。
また、かかる（２Ｂ）成分の構成成分であるα，β−不飽和酸のグリシジルエステルは下記一般式（４）で示されるものである。

（式中、Ｒ’は水素又は低級アルキル基である。）
α，β−不飽和酸のグリシジルエステルユニットは、例えばアクリル酸グリシジルエステル、メタクリル酸グリシジルエステル、エタクリル酸グリシジルエステル、イタコン酸グリシジルエステル等であるが、特にメタクリル酸グリシジルエステルが好ましい。
本発明で用いる（２Ｂ）スチレン系共重合体は、上記２成分以外に第３成分として他のビニルモノマーを１種以上使用して共重合した多元共重合体であってもよい。第３成分として好適なものは、アクリロニトリル、アクリル酸エステル、メタクリル酸エステル、無水マレイン酸等のオレフィン系不飽和エステルの１種又は２種以上であり、これらを４０重量％以下導入した多元共重合体は面衝撃強度改善において好ましい。
本発明の特徴の一つは、組成物中の（２Ｂ）スチレン系共重合体のグリシジルエステル成分比率を特定範囲に規制したことにある。即ち、総添加グリシジルエステルが０．１重量％未満あるいは１．１重量％を超える場合、面衝撃強度の改善効果が得られないため、（２Ｂ）成分のスチレン系共重合体の配合量は総添加グリシジルエステル重量％にして０．１〜１．１重量％に制限される。好ましくは０．２〜１．１重量％である。より好ましくは、０．２〜０．８重量％である。
また、（２Ｂ）成分のスチレン系共重合体中のα，β−不飽和酸のグリシジルエステル含有量が低すぎる場合、所期の効果を得るためには（２Ｂ）成分を多量に添加する必要が生じ、弾性率は向上するが、面衝撃強度が低下してしまう。そのため、（２Ｂ）成分のスチレン系共重合体中のα，β−不飽和酸のグリシジルエステル含有量は２重量％以上を必要とする。
一方、（２Ｂ）成分のスチレン系共重合体中のα，β−不飽和酸のグリシジルエステル含有量が２０重量％を超えると面衝撃強度の改善効果が低下する。
そのため、（２Ｂ）成分のスチレン系共重合体中のα，β−不飽和酸のグリシジルエステル含有量は２〜２０重量％であり、スチレン類８０〜９８重量％、α，β−不飽和酸のグリシジルエステル２０〜２重量％の比率のスチレン系共重合体が好ましい。
組成物中の総添加グリシジルエステルを０．１〜１．１重量％にするためには、例えば、（Ａ）液晶性樹脂９８〜８５重量％に対し、（２Ｂ）スチレン類８０〜９８重量％、α，β−不飽和酸のグリシジルエステル２０〜２重量％よりなるスチレン系共重合体２〜１５重量％の比率が好ましく、より好ましくは４〜１５重量％、特に４〜９重量％が好ましい。
本発明の（２Ｂ）成分であるスチレン系共重合体は、各成分のモノマーをラジカル重合触媒を用いて通常のラジカル重合法により容易に調製することができる。より具体的には、通常、スチレン類とα，β−不飽和酸のグリシジルエステルをラジカル発生剤の存在下、５００〜４０００気圧、１００〜３００℃で適当な溶媒や連鎖移動剤の存在下または不存在下に共重合させる方法により製造できる。また、スチレン類とα，β−不飽和酸のグリシジルエステル及びラジカル発生剤を混合し、押出機の中で溶融グラフト共重合させる方法によっても製造できる。
また、本発明の射出成形用液晶性樹脂組成物に、成形品の機械的物性、特に強度と剛性を付与するには、特定の繊維状充填剤、板状充填剤、粉粒状充填剤を併用する必要があり、
（Ａ）液晶性樹脂１００重量部及び
（Ｃ）平均繊維径１５μｍ以下、平均繊維長１００μｍ以下の繊維状充填剤、最大粒子径２０μｍ以下、アスペクト比３〜８の板状充填剤、平均粒子径０．２〜２μｍの粉粒状充填剤から選ばれる１種又は２種以上の無機充填剤１〜１００重量部からなる樹脂組成物に対して、
（２Ｂ）スチレン類４０〜９８重量％、α，β−不飽和酸のグリシジルエステル２０〜２重量％、他のビニルモノマー０〜４０重量％よりなるスチレン系共重合体をグリシジルエステル成分が０．１〜１．１重量％となるように溶融混練する必要がある。
即ち、（Ａ）液晶性樹脂及び（Ｃ）無機充填剤からなる樹脂組成物に対し、総添加グリシジルエステルが０．１重量％未満あるいは１．１重量％を超える場合、面衝撃強度の改善効果が得られないため、（２Ｂ）成分のスチレン系共重合体の配合量は、（Ａ）液晶性樹脂及び（Ｃ）無機充填剤からなる樹脂組成物に対し総添加グリシジルエステル重量％にして０．１〜１．１重量％、好ましくは０．２〜１．１重量％、より好ましくは０．２〜０．８重量％である。
上記記載した通りの理由により、（Ａ）液晶性樹脂及び（Ｃ）無機充填剤からなる樹脂組成物に対し、（２Ｂ）スチレン類８０〜９８重量％、α，β−不飽和酸のグリシジルエステル２０〜２重量％よりなるスチレン系共重合体を２〜１５重量％、より好ましくは４〜１５重量％、特に４〜９重量％の比率で配合するのが好ましい。
上記記載した通り、（２Ｂ）スチレン類とα，β−不飽和酸のグリシジルエステルよりなるスチレン系共重合体は、第３成分を含有しても良いことは言うまでもない。
繊維状充填剤としては平均繊維径１５μｍ以下、平均繊維長１００μｍ以下のものが用いられる。チョップドストランドのガラス繊維のような平均繊維長が１００μｍを超えるものは面衝撃強度を低下させる。かかる繊維状充填剤としては、ガラスやカーボンのミルドファイバー、アスベスト繊維、シリカ繊維、シリカ・アルミナ繊維、ジルコニア繊維、窒化硼素繊維、窒化硅素繊維、硼素繊維、チタン酸カリ繊維、さらにステンレス、アルミニウム、チタン、銅、真鍮等の金属の繊維状物などの無機質繊維状物質があげられる。本発明に用いる最も好ましい繊維状充填剤は、平均繊維径０．２〜０．７μｍ、平均繊維長１０〜３０μｍのものである。
板状充填剤としては最大粒子径２０μｍ以下、アスペクト比３〜８のものが用いられる。最大粒子径が２０μｍを超えたり、アスペクト比が３未満あるいは８を超えるものは面衝撃強度を低下させることがある。かかる板状充填剤としてはマイカ、ガラスフレーク、各種の金属箔等が挙げられる。本発明に用いる最も好ましい板状充填剤は、平均粒子径が３〜１２μｍ、最大粒子径が８〜１５μｍ、アスペクト比が３〜８のものである。
粉粒状充填剤としては平均粒子径０．２〜２μｍのものが用いられる。平均粒子径が０．２μｍ未満あるいは２μｍを超えるものは面衝撃強度を低下させることがある。かかる粉粒状充填剤としては、カーボンブラック、シリカ、石英粉末、ガラスビーズ、ガラス粉、硅酸カルシウム、硅酸アルミニウム、カオリン、タルク、クレー、珪藻土、ウォラストナイトの如き硅酸塩、酸化鉄、酸化チタン、酸化亜鉛、アルミナの如き金属の酸化物、炭酸カルシウム、炭酸マグネシウムの如き金属の炭酸塩、硫酸カルシウム、硫酸バリウムの如き金属の硫酸塩、その他炭化硅素、窒化硅素、窒化硼素、各種金属粉末等が挙げられる。本発明に用いる最も好ましい粉粒状充填剤は、平均粒子径が０．２〜１μｍのものである。
これら無機充填剤は１種又は２種以上を併用することができる。繊維状充填剤と板状充填剤または粉粒状充填剤の併用は、成形品の機械的強度と寸法精度等を兼備する上で好ましい組合せであり、特に弾性率の向上に有効である。
無機充填剤（Ｃ）の配合量は、特に制限されないが、（Ａ）液晶性樹脂１００重量部に対し１〜１００重量部であることが望ましい。
本発明の液晶性樹脂組成物には、一般に合成樹脂に添加される公知の物質、すなわち酸化防止剤や紫外線吸収剤等の安定剤、帯電防止剤、難燃剤、染料や顔料等の着色剤、潤滑剤、離型剤、および結晶化促進剤、結晶核剤等も要求性能に応じ適宜添加することができる。
本発明の組成物の調製は、上記（Ａ）、（Ｂ）、（Ｃ）成分を添加配合して溶融混練処理し、場合によってはその他の所望成分をも配合して溶融混練し、次いで射出成形に供される。かかる各成分の溶融混練は１軸又は２軸押出機を使用して一旦ペレット化した後、射出成形に供するのが一般的である。
本発明の液晶性樹脂組成物は、電気・電子機器部品、携帯電話の筺体、自動車外板等の射出成形品に好適に利用される。特に、薄肉成形性に優れているので、筺体等の肉厚２ｍｍ以下の射出成形品に有効である。The present invention provides a liquid crystalline resin composition that retains the mechanical properties, particularly fluidity and elastic modulus, possessed by the liquid crystalline resin and has improved surface impact strength.
As a result of intensive studies, the inventors of the present invention specified, in some cases, a B component that is a specific olefin copolymer (1B) or a specific styrene copolymer (2B) in the liquid crystalline resin (A). In order to complete the present invention, it is found that a resin composition satisfying excellent surface impact strength, fluidity and elastic modulus can be obtained only when a specific amount of the inorganic filler (C) is blended and melt-kneaded. It came.
The present invention relates to (A) a liquid crystalline resin, wherein (B) component is (1B) an olefin copolymer comprising an α-olefin and a glycidyl ester of α, β-unsaturated acid, and the glycidyl ester component is 0. 2 to 0.7% by weight or (2B) styrenes 40 to 98% by weight, glycidyl ester of α, β-unsaturated acid 20 to 2% by weight, other vinyl monomers 0 to 40% by weight A liquid crystalline resin composition for injection molding, which is obtained by melt-kneading a styrene-based copolymer so that the glycidyl ester component is 0.1 to 1.1% by weight.
Furthermore, the present invention provides (A) 100 parts by weight of a liquid crystalline resin and (C) a fibrous filler having an average fiber diameter of 15 μm or less and an average fiber length of 100 μm or less, a maximum particle diameter of 20 μm or less, and a plate-like filling having an aspect ratio of 3 to 8 As a component (B), (1B) for a resin composition comprising 1 to 100 parts by weight of one or more inorganic fillers selected from an agent and a granular filler having an average particle size of 0.2 to 2 μm ) An olefin copolymer composed of an α-olefin and a glycidyl ester of an α, β-unsaturated acid so that the glycidyl ester component is 0.2 to 0.7% by weight, or (2B) styrenes 40 to 98% by weight, 20% to 2% by weight of glycidyl ester of α, β-unsaturated acid, and a styrene copolymer comprising 0 to 40% by weight of other vinyl monomers, 0.1 to 1.1% by weight of glycidyl ester component To be , To provide an injection molding liquid resin composition characterized by comprising melting and kneading.
The present invention also provides an injection molded product having a thickness of 2 mm or less obtained by injection molding the liquid crystalline resin composition and a casing obtained by injection molding the liquid crystalline resin composition.
DETAILED DESCRIPTION OF THE INVENTION The liquid crystalline resin composition for injection molding of the present invention has significantly improved surface impact strength as compared with conventional liquid crystalline resin compositions, and is excellent in rigidity and fluidity. Injection molded products that can be used in various fields such as exterior parts such as digital cameras can be provided.
Hereinafter, the components of the composition of the present invention will be described in detail. The liquid crystalline resin (A) used in the present invention is a nematic liquid crystalline resin that exhibits optical anisotropy when melted, and is an indispensable element in the present invention for having both heat resistance and easy processability. The property of melt anisotropy can be confirmed by a conventional polarization inspection method using an orthogonal polarizer. Specifically, it can be confirmed by melting a sample placed on a Leitz hot stage using a Leitz polarizing microscope and observing it at a magnification of about 40 times in a nitrogen atmosphere. When the optically anisotropic polymer is inserted between crossed polarizers, polarized light is transmitted even in a molten stationary liquid state.
The liquid crystalline resin (A) used in the present invention is preferably an aromatic polyester containing at least 30 mol% or more of an aromatic hydroxycarboxylic acid group having the following general formula (1), and other general formula (2) An aromatic polyether containing a repeating unit composed of a dicarboxylic acid group represented by formula (3) and a diol represented by the general formula (3) in an amount of 35 mol% or less is also included.

-Ar _{1-in the} formula (1) constituting the main repeating unit of the liquid crystalline polyester preferably used in the present invention comprises a phenylene group and / or a naphthalene group, and these aromatic hydroxycarboxylic acids or ester-forming compounds thereof. Obtained by polycondensation of Examples of such aromatic hydroxycarboxylic acid compounds include fragrances such as 4-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, 7-hydroxy-2-naphthoic acid, and 4- (4-hydroxyphenyl) benzoic acid. Group hydroxycarboxylic acid or its ester-forming compound may be mentioned, and one or a mixture of two or more thereof may be used. In particular, as the structural unit of formula (1), those having mainly a 4-hydroxybenzoic acid group and partially containing a hydroxynaphthoic acid group are preferable. In particular, when the structural unit (2) described later is absent or very small as the structural unit of the polyester to be used, it is particularly preferable from the viewpoint of moldability that the (1) structural unit is composed of the above two types.
Then constituting the polyester (A) which are preferably used in the present invention (2) of -Ar 2 _- is a phenylene group, a naphthalene group, a diphenylene group, and a aliphatic radical in a range which holds the liquid crystal May be. Further, -R- in the formula (3) is a phenylene group, naphthalene group, biphenylene group or the like, and may be an aliphatic group having 2 to 8 carbon atoms. (2) and (3) structural units as a raw material is formed from a dicarboxylic acid _(HOOC-Ar 2 -COOH) or an ester-forming compound and a diol (HO-R-OH), this acid component and a diol component Is introduced by a polycondensation reaction with the aromatic hydroxycarboxylic acid or its ester-forming compound. (2) As the dicarboxylic acid component for constituting the formula unit, known fragrances such as terephthalic acid, 2,6-naphthalenedicarboxylic acid, isophthalic acid, 2,7-naphthalenedicarboxylic acid, 4,4′-diphenylcarboxylic acid, etc. Group dicarboxylic acid or an ester-forming compound thereof. (3) As the diol for constituting the formula unit, known aromatic diols such as hydroquinone, nucleus-substituted hydroquinone, 4,4′-biphenol, 2,6-dihydroxynaphthalene, bisphenol A, or aliphatic diol For example, one or more of ethylene glycol and cyclohexanedimethanol can be used.
In the liquid crystalline polyester (A) preferably used in the present invention, the structural unit (1) is at least 30 mol% or more, and the units (2) and (3) are each 35 mol% or less, preferably (1 ) Formula 40% or more, formula (2) and formula (3) units are each 30% or less, more preferably formula (1) formula 50% or more, formula (2) and formula (3) units are each 25% or less. . The liquid crystalline resin (A) used in the present invention is a comonomer having an ether bond or an amide bond within the range showing liquid crystallinity when melted in addition to the above formulas (1), (2) and (3). Ingredients may be introduced, and polyfunctional ester forming monomers such as pentaerythritol, trimellitic acid, trimesic acid, 4-hydroxyisophthalic acid, sodium sulfoisophthalate, An ester-forming monomer having an ionic group such as sodium parahydroxyethyl phenylsulfonate may be introduced. Particularly preferable liquid crystalline polyester resin (A) includes 4-hydroxybenzoic acid, a copolymerized aromatic polyester composed of 6-hydroxy-2-naphthoic acid, and an acid component composed of terephthalic acid and isophthalic acid in addition to this, An aromatic copolyester obtained by copolymerizing a combination monomer with a diol component comprising hydroquinone, 4,4′-biphenol, and ethylene glycol.
The liquid crystalline thermoplastic resin (A) used in the present invention can be prepared by a known method using a direct polymerization method or a transesterification method from the above monomer compounds, but usually a melt polymerization method or a slurry weight is used. Legal etc. are used. The above compounds having ester-forming ability may be used for polymerization as they are, or may be modified from a precursor to a derivative having ester-forming ability in the previous stage of polymerization. In the polymerization, various catalysts can be used, and typical ones are dialkyl tin oxide, diaryl tin oxide, titanium dioxide, alkoxy titanium silicates, titanium alcoholates, alkalis and alkalis of carboxylic acids. Examples include earth metal salts, Lewis acid salts such as BF _{3 and} the like. The amount of catalyst used is generally about 0.001 to 1% by weight, particularly about 0.01 to 0.2% by weight, based on the total weight of the monomers. If the polymer produced by these polymerization methods is further necessary, the molecular weight can be increased by solid-phase polymerization by heating in a reduced pressure or an inert gas. The melt viscosity of the liquid crystalline resin (A) used in the present invention is not particularly limited and may be any as long as it can be injection-molded. Generally, those having a melt viscosity at a molding temperature of 10 MPa or more and 600 MPa or less at a shear rate of 1000 sec ⁻¹ can be used. However, those having a very high viscosity are not preferable because the fluidity is extremely deteriorated. The liquid crystalline resin (A) may be a mixture of two or more liquid crystalline resins.
Next, the component (B) in the present invention will be described.
The olefin copolymer of the component (1B) in the present invention has an effect of remarkably improving the surface impact strength when blended with the base liquid crystalline resin (A). The olefin copolymer of component (1B) is composed of an glycidyl ester of an α-olefin and an α, β-unsaturated acid.
Specific examples of the α-olefin as the component (1B) include ethylene, propylene, butene and the like. Among them, ethylene is preferably used. Further, glycidyl ester of α, β-unsaturated acid, which is another component of component (1B), is represented by the following general formula (4).

(In the formula, R ′ is hydrogen or a lower alkyl group.)
Examples of the glycidyl ester unit of α, β-unsaturated acid include glycidyl acrylate, glycidyl methacrylate, glycidyl ethacrylate, glycidyl itaconate and the like, and glycidyl methacrylate is particularly preferable.
The (1B) olefin copolymer used in the present invention is a acrylonitrile, acrylic acid ester, methacrylic acid ester, α-methylstyrene, maleic anhydride, etc. as a third component in addition to the above two components within the range not impairing the present invention. You may contain 0-48 weight part of 1 type, or 2 or more types of an olefin type unsaturated ester with respect to 100 weight part of said 2 components.
One of the features of the present invention is that the ratio of the glycidyl ester component of the (1B) olefin copolymer in the composition is regulated within a specific range. That is, when the total added glycidyl ester is less than 0.2% by weight or more than 0.7% by weight, the effect of improving the surface impact strength cannot be obtained. Therefore, the blending amount of the olefin copolymer of the component (1B) is The amount of added glycidyl ester is limited to 0.2 to 0.7% by weight. Most preferably, it is 0.2 to 0.6% by weight.
In addition, when the content of the glycidyl ester of α, β-unsaturated acid in the olefin copolymer of component (1B) is too low, it is necessary to add a large amount of component (1B) in order to improve the surface impact strength. Occurs and the rigidity (elastic modulus) decreases. Therefore, the glycidyl ester content of the α, β-unsaturated acid in the olefin copolymer of the component (1B) needs to be 2% by weight or more.
On the other hand, when the glycidyl ester content of α, β-unsaturated acid in the olefin copolymer of component (1B) exceeds 13% by weight, the effect of improving the surface impact strength is lowered.
Therefore, the content of glycidyl ester of α, β-unsaturated acid in the olefin copolymer of component (1B) is 2 to 13% by weight, α-olefin 87 to 98% by weight, α, β-unsaturated. An olefin copolymer in a ratio of 13 to 2% by weight of glycidyl ester of acid is preferred.
In order to adjust the total added glycidyl ester in the composition to 0.2 to 0.7% by weight, for example, (A) liquid crystal resin 97.5 to 92% by weight, (1B) α-olefin 87 to A ratio of 2.5 to 8% by weight of an olefin copolymer comprising 98% by weight and 13 to 2% by weight of a glycidyl ester of an α, β-unsaturated acid is preferable.
The olefin copolymer which is the component (1B) of the present invention can be easily prepared by a normal radical polymerization method using a monomer for each component and a radical polymerization catalyst. More specifically, usually an α-olefin and an α, β-unsaturated glycidyl ester in the presence of a radical generator at 500 to 4000 atm and 100 to 300 ° C. in the presence of a suitable solvent or chain transfer agent. Or it can manufacture by the method of copolymerizing in absence. It can also be produced by a method in which an α-olefin, an α, β-unsaturated glycidyl ester and a radical generator are mixed and melt graft copolymerized in an extruder.
In addition, in order to impart mechanical properties of molded products, particularly strength and rigidity, to the liquid crystalline resin composition for injection molding of the present invention, a specific fibrous filler, plate-like filler, and granular filler are used in combination. Need to
(A) 100 parts by weight of a liquid crystalline resin and (C) a fibrous filler having an average fiber diameter of 15 μm or less, an average fiber length of 100 μm or less, a maximum particle diameter of 20 μm or less, a plate-like filler having an aspect ratio of 3 to 8, and an average particle diameter For a resin composition comprising 1 to 100 parts by weight of one or more inorganic fillers selected from 0.2 to 2 μm granular fillers,
(1B) It is necessary to melt-knead an olefin copolymer comprising an α-olefin and a glycidyl ester of an α, β-unsaturated acid so that the glycidyl ester component is 0.2 to 0.7% by weight.
That is, when the total added glycidyl ester is less than 0.2% by weight or more than 0.7% by weight with respect to the resin composition comprising (A) liquid crystalline resin and (C) inorganic filler, the effect of improving the surface impact strength Therefore, the blending amount of the olefin copolymer of component (1B) is 0 in terms of the total amount of glycidyl ester added to the resin composition comprising (A) liquid crystalline resin and (C) inorganic filler. .2 to 0.7% by weight, preferably 0.2 to 0.6% by weight.
For the reasons described above, (1B) 87 to 98% by weight of α-olefin and α, β-unsaturated glycidyl with respect to the resin composition comprising (A) liquid crystalline resin and (C) inorganic filler. It is preferable to blend an olefin copolymer comprising 13 to 2% by weight of the ester in a ratio of 2.5 to 8% by weight.
As described above, it goes without saying that the olefin copolymer comprising (1B) an α-olefin and a glycidyl ester of an α, β-unsaturated acid may contain a third component.
Next, the styrene copolymer of the component (2B) in the present invention has an effect of remarkably improving the surface impact strength by being blended with the base liquid crystalline resin (A). The component (2B) styrene copolymer is composed of 40 to 98% by weight of styrenes and 20 to 2% by weight of glycidyl ester of α, β-unsaturated acid.
Examples of the styrene as the component of the component (2B) include styrene, α-methylstyrene, brominated styrene, divinylbenzene and the like, and styrene is preferably used.
Moreover, the glycidyl ester of α, β-unsaturated acid, which is a component of the component (2B), is represented by the following general formula (4).

(In the formula, R ′ is hydrogen or a lower alkyl group.)
Examples of the glycidyl ester unit of α, β-unsaturated acid include glycidyl acrylate, glycidyl methacrylate, glycidyl ethacrylate, glycidyl itaconate and the like, and glycidyl methacrylate is particularly preferable.
The (2B) styrenic copolymer used in the present invention may be a multi-component copolymer obtained by copolymerization using one or more other vinyl monomers as the third component in addition to the above two components. Suitable as the third component is one or more of olefinic unsaturated esters such as acrylonitrile, acrylic acid ester, methacrylic acid ester, maleic anhydride, etc., and multi-component copolymer having 40% by weight or less thereof introduced. The coalescence is preferable in improving the surface impact strength.
One of the characteristics of the present invention is that the ratio of the glycidyl ester component of the (2B) styrene copolymer in the composition is regulated within a specific range. That is, when the total added glycidyl ester is less than 0.1% by weight or more than 1.1% by weight, the effect of improving the surface impact strength cannot be obtained. Therefore, the blending amount of the styrene copolymer of component (2B) is The added glycidyl ester is limited to 0.1 to 1.1% by weight. Preferably it is 0.2-1.1 weight%. More preferably, it is 0.2 to 0.8% by weight.
In addition, when the content of glycidyl ester of α, β-unsaturated acid in the styrene copolymer of component (2B) is too low, it is necessary to add a large amount of component (2B) in order to obtain the desired effect. And the elastic modulus is improved, but the surface impact strength is reduced. Therefore, the glycidyl ester content of α, β-unsaturated acid in the styrene copolymer of component (2B) needs to be 2% by weight or more.
On the other hand, when the glycidyl ester content of the α, β-unsaturated acid in the styrene copolymer of the component (2B) exceeds 20% by weight, the effect of improving the surface impact strength is lowered.
Therefore, the glycidyl ester content of α, β-unsaturated acid in the styrene copolymer of component (2B) is 2 to 20% by weight, styrenes are 80 to 98% by weight, and α, β-unsaturated acid. A styrene copolymer having a ratio of 20 to 2% by weight of glycidyl ester is preferred.
In order to make the total added glycidyl ester in the composition 0.1 to 1.1% by weight, for example, (A) 98 to 85% by weight of the liquid crystalline resin, (2B) 80 to 98% by weight of styrenes A ratio of 2 to 15% by weight of a styrene copolymer comprising 20 to 2% by weight of a glycidyl ester of an α, β-unsaturated acid is preferred, more preferably 4 to 15% by weight, and particularly preferably 4 to 9% by weight. .
The styrene copolymer which is the component (2B) of the present invention can be easily prepared by a normal radical polymerization method using the monomers of the respective components using a radical polymerization catalyst. More specifically, styrenes and glycidyl esters of α, β-unsaturated acids are usually used in the presence of a radical generator at 500 to 4000 atm and 100 to 300 ° C. in the presence of a suitable solvent or chain transfer agent or It can be produced by a method of copolymerization in the absence. It can also be produced by a method in which styrenes, an α, β-unsaturated glycidyl ester and a radical generator are mixed and melt graft copolymerized in an extruder.
In addition, in order to impart mechanical properties of molded products, particularly strength and rigidity, to the liquid crystalline resin composition for injection molding of the present invention, a specific fibrous filler, plate-like filler, and granular filler are used in combination. Need to
(A) 100 parts by weight of a liquid crystalline resin and (C) a fibrous filler having an average fiber diameter of 15 μm or less, an average fiber length of 100 μm or less, a maximum particle diameter of 20 μm or less, a plate-like filler having an aspect ratio of 3 to 8, and an average particle diameter For a resin composition comprising 1 to 100 parts by weight of one or more inorganic fillers selected from 0.2 to 2 μm granular fillers,
(2B) A styrene copolymer composed of 40 to 98% by weight of styrenes, 20 to 2% by weight of glycidyl ester of α, β-unsaturated acid, and 0 to 40% by weight of other vinyl monomers has a glycidyl ester component of 0. It is necessary to melt-knead so that it may become 1-1.1 weight%.
That is, when the total added glycidyl ester is less than 0.1% by weight or more than 1.1% by weight with respect to the resin composition comprising (A) liquid crystalline resin and (C) inorganic filler, the effect of improving the surface impact strength Therefore, the blending amount of the styrene copolymer of the component (2B) is 0 in terms of the total amount of glycidyl ester added to the resin composition comprising (A) liquid crystalline resin and (C) inorganic filler. 0.1 to 1.1% by weight, preferably 0.2 to 1.1% by weight, more preferably 0.2 to 0.8% by weight.
For the reasons described above, (2B) 80 to 98% by weight of styrenes and α, β-unsaturated glycidyl ester with respect to the resin composition comprising (A) liquid crystalline resin and (C) inorganic filler. It is preferable to blend a styrene copolymer comprising 20 to 2% by weight in a ratio of 2 to 15% by weight, more preferably 4 to 15% by weight, and particularly 4 to 9% by weight.
As described above, it goes without saying that (2B) a styrene copolymer comprising styrenes and a glycidyl ester of an α, β-unsaturated acid may contain a third component.
As the fibrous filler, those having an average fiber diameter of 15 μm or less and an average fiber length of 100 μm or less are used. Those having an average fiber length exceeding 100 μm, such as glass fibers of chopped strands, reduce the surface impact strength. Examples of the fibrous filler include glass and carbon milled fiber, asbestos fiber, silica fiber, silica / alumina fiber, zirconia fiber, boron nitride fiber, silicon nitride fiber, boron fiber, potassium titanate fiber, stainless steel, aluminum, Examples thereof include inorganic fibrous materials such as metallic fibrous materials such as titanium, copper, and brass. The most preferred fibrous filler used in the present invention has an average fiber diameter of 0.2 to 0.7 μm and an average fiber length of 10 to 30 μm.
As the plate-like filler, those having a maximum particle diameter of 20 μm or less and an aspect ratio of 3 to 8 are used. When the maximum particle diameter exceeds 20 μm or the aspect ratio is less than 3 or exceeds 8, the surface impact strength may be reduced. Examples of the plate filler include mica, glass flakes, various metal foils and the like. The most preferred plate-like filler used in the present invention has an average particle diameter of 3 to 12 μm, a maximum particle diameter of 8 to 15 μm, and an aspect ratio of 3 to 8.
As the granular filler, those having an average particle diameter of 0.2 to 2 μm are used. When the average particle diameter is less than 0.2 μm or more than 2 μm, the surface impact strength may be reduced. Such granular fillers include carbon black, silica, quartz powder, glass beads, glass powder, calcium oxalate, aluminum oxalate, kaolin, talc, clay, diatomaceous earth, oxalates such as wollastonite, iron oxide, Metal oxides such as titanium oxide, zinc oxide, and alumina, carbonates of metals such as calcium carbonate and magnesium carbonate, sulfates of metals such as calcium sulfate and barium sulfate, silicon carbide, silicon nitride, boron nitride, various metals A powder etc. are mentioned. The most preferable granular filler used in the present invention has an average particle size of 0.2 to 1 μm.
These inorganic fillers can be used alone or in combination of two or more. The combined use of the fibrous filler and the plate-like filler or the granular filler is a preferable combination in order to combine the mechanical strength and dimensional accuracy of the molded product, and is particularly effective for improving the elastic modulus.
Although the compounding quantity of an inorganic filler (C) is not restrict | limited in particular, It is desirable that it is 1-100 weight part with respect to 100 weight part of (A) liquid crystalline resin.
In the liquid crystalline resin composition of the present invention, known substances generally added to synthetic resins, that is, stabilizers such as antioxidants and ultraviolet absorbers, antistatic agents, flame retardants, colorants such as dyes and pigments, Lubricants, mold release agents, crystallization accelerators, crystal nucleating agents, and the like can be appropriately added according to the required performance.
The composition of the present invention is prepared by adding and blending the above components (A), (B), and (C), melt-kneading treatment, and optionally blending with other desired components, followed by injection. Used for molding. In general, the melt kneading of each component is once pelletized using a single-screw or twin-screw extruder and then subjected to injection molding.
The liquid crystalline resin composition of the present invention is suitably used for injection molded products such as electric / electronic device parts, mobile phone casings, and automobile outer panels. In particular, since it is excellent in thin moldability, it is effective for injection molded products having a thickness of 2 mm or less such as a casing.

図１は、落錘試験に用いた先端が半球状の治具を示す図である。 FIG. 1 is a view showing a jig having a hemispherical tip used in the falling weight test.

以下に実施例をもって本発明を更に詳しく説明するが、本発明はこれらに限定されるものではない。使用した各成分は以下のものである。
製造例１（全芳香族ポリエステル液晶樹脂（成分（Ａ））の合成）
ｐ−ヒドロキシ安息香酸３４５重量部（７３モル％）、６−ヒドロキシ−２−ナフトエ酸１７５重量部（２７モル％）、酢酸カリウム０．０２重量部、無水酢酸３５０重量部を、攪拌機及び留出管を備えた反応器に仕込み、十分に窒素置換した後、常圧下で１５０℃まで温度を上げ、攪拌を開始した。１５０℃で３０分攪拌し、更に徐々に温度を上昇させ、副生する酢酸を留去した。温度が３００℃に達したところで、徐々に反応器を減圧し、５Ｔｏｒｒ（即ち６６５Ｐａ）の圧力で１時間攪拌を続け、目標の攪拌トルクに達した時点で、反応器下部の排出孔を開け、窒素圧を使って樹脂をストランド状に取り出した。排出されたストランドをペレタイザーにより粒子状にした。この全芳香族ポリエステル液晶樹脂の融点は２８０℃、３００℃での溶融粘度は５０．１Ｐａ・ｓであった。
（１Ｂ）オレフィン系共重合体としては下記のものを使用した。
・（１Ｂ−１）住友化学（株）製、Ｂｏｎｄｆａｓｔ２Ｃ［エチレン−グリシジルメタクリレート共重合体（グリシジルメタクリレートを６重量％含有）］
・（１Ｂ−２）住友化学（株）製、ＢｏｎｄｆａｓｔＥ［エチレン−グリシジルメタクリレート共重合体（グリシジルメタクリレートを１２重量％含有）］
・（１Ｂ−３）アトフィナジャパン（株）製、ＬＯＴＡＤＡＲＡＸ８８４０［エチレン−グリシジルメタクリレート共重合体（グリシジルメタクリレートを８重量％含有）］
（Ｃ）無機充填剤としては下記のものを使用した。
・（Ｃ−１）シリカ［アドマテックス（株）製、アドマファインシリカＳＯＣ−２（平均粒子径０．５μｍ）］
・（Ｃ−２）タルク［松村産業（株）製、クラウンタルクＰＰ（最大粒子径１１μｍ、平均アスペクト比６）］
・（Ｃ−３）チタン酸カリウム繊維［大塚化学（株）製、ティスモＮ−１０２（平均繊維径０．３〜０．６μｍ、平均繊維長１０〜２０μｍ）］
・（Ｃ−４）ガラス長繊維製品［旭ファイバーグラス（株）製、グラスロン・チョップドストランドＣＳ０３ＪＡ４１６（平均繊維径１０μｍ、チョップドストランド長３ｍｍ）］
実施例１〜４、比較例１〜６
上記（Ａ）、（１Ｂ）、（Ｃ）成分を表１−１、１−２に示す割合で二軸押出機（（株）日本製鋼所製ＴＥＸ３０α型）を用いてシリンダー温度３００℃にて溶融混練し、樹脂組成物のペレットを得て、射出成形に供し、評価した。落錘衝撃試験用試験片としては、ファナック社製Ｒｏｂｏｓｈｏｔ α−１００ｉＡ成形機を用い、シリンダー温度３００℃、金型温度８０℃の条件で０．７ｍｍの平板を成形した。ＩＳＯ曲げ試験用試験片としては、日鋼Ｊ７５ＳＳＩＩ−Ａ成形機を用い、シリンダー温度３００℃、金型温度９０℃の条件で成形した。
尚、特性値の評価に用いた測定法は以下の通りである。
［溶融粘度］
キャピラリー式レオメーター（東洋精機製キャピログラフ１Ｂ：ピストン径１０ｍｍ）により、温度Ｔ１（樹脂の融点＋２０℃）、剪断速度１０００ｓｅｃ^−１の条件での見掛けの溶融粘度をＩＳＯ１１４４３に準拠して測定した。測定には、内径１ｍｍ、長さ２０ｍｍのオリフィスを用いた。
［ＩＳＯ曲げ強度及び弾性率］
ＩＳＯ１７８に準拠して測定した。
［打ち抜き試験］
オリエンテック製テンシロンＵＴＡ−５０ｋＮ試験機で０．７ｍｍ厚の平板試験片を用いて打ち抜き試験を行った。先端直径１６ｍｍの半球状打ち抜き治具を用い、試験速度１００ｍｍ／ｍｉｎで試験を行った。
［落錘試験］
固定した平板試験片中央部に、図１に示す先端が半球状（球直径；１２ｍｍ）の治具をのせ、この治具の上に任意の重さの重錘を任意の高さから落下させ、試験片が破壊するかを確認した。
以下の計算式に基づき、５０％破壊エネルギーを算出した。
錘を落とす高さは１ｃｍ間隔で変化させ、５０％の試験片が破壊する高さ（５０％破壊高さ）を求めた。求められた５０％破壊高さより下式により５０％破壊エネルギーを求めた。
５０％破壊エネルギー（Ｅ／（Ｊ））＝（錘の質量（ｋｇ））×（重力加速度（９．８０６６５ｍ／ｓ^２））×（５０％破壊高さ（ｍ））
結果を表１−１、１−２に示す。
実施例２−１〜２−８、比較例２−１〜２−３
上記（Ａ）、下記（２Ｂ）、上記（Ｃ）成分を表２−１、２−２に示す割合で使用した以外は、実施例１と同様にして樹脂組成物のペレットを得て、実施例１と同様にして評価した。結果を表２−１、２−２に示す。
（２Ｂ）スチレン系共重合体としては下記のものを使用した。
・（２Ｂ−１）日本油脂（株）製、マープルーフＧ１００５Ｓ［スチレン−グリシジルメタクリレート共重合体（グリシジルメタクリレートを４．３重量％含有）］
・（２Ｂ−２）日本油脂（株）製、マープルーフＧ１０１０Ｓ［スチレン−グリシジルメタクリレート共重合体（グリシジルメタクリレートを８．４重量％含有）］

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto. Each component used is as follows.
Production Example 1 (Synthesis of wholly aromatic polyester liquid crystal resin (component (A)))
345 parts by weight (73 mol%) of p-hydroxybenzoic acid, 175 parts by weight (27 mol%) of 6-hydroxy-2-naphthoic acid, 0.02 parts by weight of potassium acetate, and 350 parts by weight of acetic anhydride were stirred and distilled. After charging in a reactor equipped with a tube and sufficiently purging with nitrogen, the temperature was raised to 150 ° C. under normal pressure, and stirring was started. The mixture was stirred at 150 ° C. for 30 minutes, and the temperature was gradually raised, and acetic acid produced as a by-product was distilled off. When the temperature reached 300 ° C., the reactor was gradually depressurized and stirring was continued for 1 hour at a pressure of 5 Torr (ie, 665 Pa). When the target stirring torque was reached, a discharge hole at the bottom of the reactor was opened, The resin was taken out into strands using nitrogen pressure. The discharged strand was made into particles by a pelletizer. The wholly aromatic polyester liquid crystal resin had a melting point of 280 ° C. and a melt viscosity at 300 ° C. of 50.1 Pa · s.
(1B) The following were used as the olefin copolymer.
-(1B-1) Bondfast 2C manufactured by Sumitomo Chemical Co., Ltd. [ethylene-glycidyl methacrylate copolymer (containing 6% by weight of glycidyl methacrylate)]
-(1B-2) Bondfast E [ethylene-glycidyl methacrylate copolymer (containing 12% by weight of glycidyl methacrylate)] manufactured by Sumitomo Chemical Co., Ltd.]
-(1B-3) LOTADAR AX8840 [ethylene-glycidyl methacrylate copolymer (containing 8% by weight of glycidyl methacrylate)] manufactured by Atofina Japan Co., Ltd.]
(C) The following were used as inorganic fillers.
-(C-1) Silica [manufactured by Admatechs Co., Ltd., Admafine Silica SOC-2 (average particle size 0.5 μm)]
-(C-2) Talc [Matsumura Sangyo Co., Ltd., Crown Talc PP (maximum particle size 11 μm, average aspect ratio 6)]
(C-3) Potassium titanate fiber [Otsuka Chemical Co., Ltd., Tismo N-102 (average fiber diameter 0.3 to 0.6 μm, average fiber length 10 to 20 μm)]
-(C-4) Glass fiber product [Asahi Fiber Glass Co., Ltd., Glasslon chopped strand CS03JA416 (average fiber diameter 10 μm, chopped strand length 3 mm)]
Examples 1-4, Comparative Examples 1-6
The above components (A), (1B), and (C) were mixed at a cylinder temperature of 300 ° C. using a twin screw extruder (TEX30α type, manufactured by Nippon Steel Works) at the ratio shown in Tables 1-1 and 1-2. The mixture was melt-kneaded to obtain resin composition pellets, which were subjected to injection molding and evaluated. As a test piece for a drop weight impact test, a 0.7 mm flat plate was molded under the conditions of a cylinder temperature of 300 ° C. and a mold temperature of 80 ° C. using a robot α-100iA molding machine manufactured by FANUC. As a test piece for an ISO bending test, a Nikko J75SSII-A molding machine was used and molded under conditions of a cylinder temperature of 300 ° C. and a mold temperature of 90 ° C.
The measurement methods used for evaluating the characteristic values are as follows.
[Melt viscosity]
The apparent melt viscosity under conditions of a temperature T1 (resin melting point + 20 ° C.) and a shear rate of 1000 sec ⁻¹ was measured according to ISO 11443 using a capillary rheometer (Capillograph 1B manufactured by Toyo Seiki: piston diameter 10 mm). For the measurement, an orifice having an inner diameter of 1 mm and a length of 20 mm was used.
[ISO bending strength and elastic modulus]
Measured according to ISO 178.
[Punching test]
A punching test was conducted using a flat test piece having a thickness of 0.7 mm using an Orientec Tensilon UTA-50kN testing machine. The test was conducted at a test speed of 100 mm / min using a hemispherical punching jig having a tip diameter of 16 mm.
[Falling weight test]
A jig with a hemispherical tip (sphere diameter: 12 mm) shown in FIG. 1 is placed on the center of the fixed flat plate test piece, and a weight of any weight is dropped from any height onto this jig. It was confirmed whether the test piece was broken.
Based on the following calculation formula, 50% fracture energy was calculated.
The height at which the weight was dropped was changed at intervals of 1 cm, and the height at which 50% of the test piece was broken (50% breaking height) was determined. The 50% fracture energy was determined from the determined 50% fracture height by the following formula.
50% fracture energy (E / (J)) = (mass of weight (kg)) × (gravity acceleration (9.80665 m / s ² )) × (50% fracture height (m))
The results are shown in Tables 1-1 and 1-2.
Examples 2-1 to 2-8, Comparative examples 2-1 to 2-3
Except having used said (A), following (2B), and said (C) component in the ratio shown to Table 2-1, 2-2, it obtained the pellet of the resin composition like Example 1, and implemented. Evaluation was performed in the same manner as in Example 1. The results are shown in Tables 2-1 and 2-2.
(2B) The following were used as the styrene copolymer.
-(2B-1) Nippon Oil & Fats Co., Ltd., Marproof G1005S [styrene-glycidyl methacrylate copolymer (containing 4.3% by weight of glycidyl methacrylate)]
-(2B-2) Nippon Oil & Fats Co., Ltd., Marproof G1010S [styrene-glycidyl methacrylate copolymer (containing 8.4% by weight of glycidyl methacrylate)]

Claims

(A) As a component (B) with respect to the liquid crystalline resin, (1B) an olefin copolymer composed of a glycidyl ester of an α-olefin and an α, β-unsaturated acid has a glycidyl ester component of 0.2 to 0. 0.7% by weight or (2B) a styrene system comprising 40 to 98% by weight of styrenes, 20 to 2% by weight of glycidyl ester of α, β-unsaturated acid, and 0 to 40% by weight of other vinyl monomers A liquid crystalline resin composition for injection molding, wherein the copolymer is melt-kneaded so that the glycidyl ester component is 0.1 to 1.1% by weight.

(A) 97.5 to 92% by weight of liquid crystalline resin
(1B) The injection molding according to claim 1, comprising 2.5 to 8% by weight of an olefin copolymer consisting of 87 to 98% by weight of α-olefin and 13 to 2% by weight of glycidyl ester of α, β-unsaturated acid. Liquid crystalline resin composition.

(A) Liquid crystalline resin 98 to 85% by weight
(2B) Comprising 2 to 15% by weight of a styrene copolymer comprising 40 to 98% by weight of styrene, 20 to 2% by weight of a glycidyl ester of α, β-unsaturated acid, and 0 to 40% by weight of another vinyl monomer. The liquid crystalline resin composition for injection molding according to claim 1.

(A) 100 parts by weight of a liquid crystalline resin and (C) a fibrous filler having an average fiber diameter of 15 μm or less, an average fiber length of 100 μm or less, a maximum particle diameter of 20 μm or less, a plate-like filler having an aspect ratio of 3 to 8, and an average particle diameter For the resin composition consisting of 1 to 100 parts by weight of one or more inorganic fillers selected from 0.2 to 2 μm granular fillers,
(1B) An olefin copolymer comprising an α-olefin and a glycidyl ester of an α, β-unsaturated acid so that the glycidyl ester component is 0.2 to 0.7% by weight, or (2B) styrenes A styrene copolymer comprising 40 to 98% by weight, 20 to 2% by weight of a glycidyl ester of α, β-unsaturated acid, and 0 to 40% by weight of another vinyl monomer is contained in a glycidyl ester component of 0.1 to 1.1. A liquid crystalline resin composition for injection molding, characterized by being melt-kneaded so as to have a weight%.

(A) 97.5 to 92% by weight of a resin composition comprising 100 parts by weight of a liquid product resin and 1 to 100 parts by weight of (C) an inorganic filler.
(1B) The injection molding according to claim 4, comprising 2.5 to 2% by weight of an olefin copolymer comprising 87 to 98% by weight of α-olefin and 13 to 2% by weight of glycidyl ester of α, β-unsaturated acid. Liquid crystalline resin composition.

(A) Resin composition consisting of 100 parts by weight of liquid crystalline resin and (C) 1 to 100 parts by weight of inorganic filler 98 to 85% by weight
(2B) Comprising 2 to 15% by weight of a styrene copolymer comprising 40 to 98% by weight of styrene, 20 to 2% by weight of a glycidyl ester of α, β-unsaturated acid, and 0 to 40% by weight of another vinyl monomer. The liquid crystalline resin composition for injection molding according to claim 4.

The injection according to any one of claims 1, 2, 4 and 5, wherein the component (1B) is an ethylene copolymer comprising 87 to 98% by weight of ethylene and 13 to 2% by weight of α, β-glycidyl methacrylate. Liquid crystalline resin composition for molding.

The component (2B) is a styrene copolymer comprising 80 to 98% by weight of styrenes and 20 to 2% by weight of α, β-glycidyl methacrylate, according to any one of claims 1, 3, 4 and 6. Liquid crystalline resin composition for injection molding.

The component (1B) contains one or more selected from acrylonitrile, (meth) acrylic acid ester, α-methylstyrene, and maleic anhydride as the third component. The liquid crystalline resin composition for injection molding according to any one of 4, 5, and 7.

The component (2B) contains one or more selected from acrylonitrile, (meth) acrylic acid ester, and maleic anhydride as the third component. The liquid crystalline resin composition for injection molding according to any one of the above.

An injection molded product having a thickness of 2 mm or less obtained by injection molding the liquid crystalline resin composition according to any one of claims 1 to 10.

A casing obtained by injection molding the liquid crystalline resin composition according to any one of claims 1 to 10.