JP4587606B2 - Polycarbonate flame retardant resin composition - Google Patents

Description

たとえば、スチレン７５％とアクリロニトリル２５％からなる共重合体の溶解度パラメーターは、ポリスチレンの溶解度パラメーター９．０３、とポリアクリロニトリルの溶解度パラメーター１２．７１を用いて式（１）に代入して９．９５の値がえられる。
【００３８】
また、ビニル系単量体を２段階以上で、かつ各段階においてビニル系単量体の種類を変えて重合してえられるビニル系重合体の溶解度パラメーターδｓは、最終的にえられたビニル系重合体の全重量を各段階でえられたビニル系重合体の重量で割った値、すなわち重量分率で加成性が成立するとした。すなわち、ｑ段階で重合し、各段階でえられた重合体の溶解度パラメータδｉとその重量分率Ｗｉとから式（２）により算出できる。
【００３９】
【数２】

たとえば、２段階で重合し、１段階目にスチレン７５％とアクリロニトリル２５％からなる共重合体が５０部えられ、２段階目にメタクリル酸メチルの重合体が５０部えられたとすると、この２段階の重合でえられた重合体の溶解度パラメーターは、スチレン（７５％）−アクリロニトリル（２５％）共重合体の溶解度パラメーター９．９５とポリメタクリル酸メチルの溶解度パラメーター９．２５を用いて式（２）に代入して９．６０の値がえられる。
【００４０】
ビニル系単量体（ｂ−２）の使用量は、前記ポリオルガノシロキサン粒子（ｂ−１）４０〜９０％、さらには５０〜８０％、とくには５０〜７５％に対して合計量が１００％になるように、６０〜１０％、さらには５０〜２０％、とくには５０〜２５％であることが好ましい。
【００４１】
前記ビニル系単量体（ｂ−２）の使用量が多すぎるばあい、少なすぎるばあい、いずれも、難燃性が十分発現しなくなる傾向にある。
【００４２】
前記ビニル系単量体（ｂ−２）としては、たとえばスチレン、α−メチルスチレン、パラメチルスチレン、パラブチルスチレンなどの芳香族ビニル系単量体、アクリロニトリル、メタクリロニトリルなどのシアン化ビニル系単量体、アクリル酸メチル、アクリル酸エチル、アクリル酸プロピル、アクリル酸ブチル、アクリル酸−２−エチルヘキシル、アクリル酸グリシジル、アクリル酸ヒドロキシエチル、メタクリル酸メチル、メタクリル酸エチル、メタクリル酸ブチル、メタクリル酸ラウリル、メタクリル酸グリシジル、メタクリル酸ヒドロキシエチルなどの（メタ）アクリル酸エステル系単量体、イタコン酸、（メタ）アクリル酸、フマル酸、マレイン酸などのカルボキシル基含有ビニル系単量体などがあげられる。これらは、前述したように重合体の溶解度パラメーターが前記記載の範囲に入る限り、単独で用いてもよく２種以上を組み合わせて用いてもよい。
【００４３】
前記グラフト重合は、通常のシード乳化重合が適用でき、ポリオルガノシロキサン粒子（ｂ−１）のラテックス中で前記ビニル系単量体（ｂ−２）のラジカル重合を行なえばよい。また、ビニル系単量体（ｂ−２）は、１段階で重合させてもよく２段階以上で重合させてもよい。
【００４４】
前記ラジカル重合としては、ラジカル重合開始剤を熱分解することにより反応を進行させる方法でも、また、還元剤を使用するレドックス系での反応などとくに限定なく行なうことができる。
【００４５】
ラジカル重合開始剤の具体例としては、クメンハイドロパーオキサイド、ｔ−ブチルハイドロパーオキサイド、ベンゾイルパーオキサイド、ｔ−ブチルパーオキシイソプロピルカーボネート、ジ−ｔ−ブチルパーオキサイド、ｔ−ブチルパーオキシラウレイト、ラウロイルパーオキサイド、コハク酸パーオキサイド、シクロヘキサンノンパーオキサイド、アセチルアセトンパーオキサイドなどの有機過酸化物、過硫酸カリウム、過硫酸アンモニウムなどの無機過酸化物、２，２’−アゾビスイソブチロニトリル、２，２’−アゾビス−２，４−ジメチルバレロニトリルなどのアゾ化合物などがあげられる。このうち、反応性の高さから有機過酸化物または無機過酸化物が特に好ましい。
【００４６】
また、前記レドックス系で使用される還元剤としては硫酸第一鉄／グルコース／ピロリン酸ナトリウム、硫酸第一鉄／デキストロース／ピロリン酸ナトリウム、または硫酸第一鉄／ナトリウムホルムアルデヒドスルホキシレート／エチレンジエアミン酢酸塩などの混合物などがあげられる。
【００４７】
前記ラジカル重合開始剤の使用量は、用いられるポリオルガノシロキサン粒子（ｂ−１）１００部に対して、通常、０．００５〜２０部、さらには０．０１〜１０部であり、とくには０．０３〜５部であるのが好ましい。前記ラジカル重合開始剤の量が０．００５部未満のばあいには反応速度が低く、生産効率がわるくなる傾向があり、２０部をこえると反応中の発熱が大きくなり生産が難しくなる傾向がある。
【００４８】
また、ラジカル重合の際に要すれば連鎖移動剤も使用できる。該連鎖移動剤は通常の乳化重合で用いられているものであればよく、とくに限定はされない。
【００４９】
前記連鎖移動剤の具体例としては、ｔ−ドデシルメルカプタン、ｎ−オクチルメルカプタン、ｎ−テトラデシルメルカプタン、ｎ−ヘキシルメルカプタンなどがあげられる。
【００５０】
連鎖移動剤は任意成分であるが、使用するばあいの使用量は、ビニル系単量体（ｂ−２）１００部に対して０．０１〜５部であることが好ましい。前記連鎖移動剤の量が０．０１部未満のばあいには用いた効果がえられず、５部をこえると重合速度が遅くなり生産効率が低くなる傾向がある。
【００５１】
また、重合時の反応温度は、通常３０〜１２０℃であるのが好ましい。
【００５２】
前記重合では、ポリオルガノシロキサン粒子（ｂ−１）がビニル系重合性基を含有するばあいにはビニル系単量体（ｂ−２）がラジカル重合開始剤によって重合する際に、ポリオルガノシロキサン粒子（ｂ−１）のビニル系重合性基と反応することにより、グラフトが形成される。ポリオルガノシロキサン粒子（ｂ−１）にビニル重合性基が存在しないばあい、特定のラジカル開始剤、たとえばｔ−ブチルパーオキシラウレートなどを用いれば、ケイ素原子に結合したメチル基などの有機基から水素を引く抜き、生成したラジカルによってビニル系単量体（ｂ−２）が重合しグラフトが形成される。
【００５３】
また、ビニル系単量体（ｂ−２）のうちの０．１〜１０％、好ましくは０．５〜５％をビニル系重合性基含有シラン化合物を用いて重合し、ｐＨ５以下の酸性状態下で再分配反応させてもグラフトが生成する。これは、酸性状態ではポリオルガノシロキサンの主骨格のＳｉ−Ｏ−Ｓｉ結合は、切断と生成の平衡状態にあるので、この平衡状態でビニル系単量体とビニル系重合性基含有シラン化合物を共重合すると、重合によって生成中あるいは生成したビニル系共重合体の側鎖のシランがポリオルガノシロキサン鎖と反応してグラフトが生成するのである。該ビニル系重合性基含有シラン化合物は、ポリオルガノシロキサン粒子（ｂ−１）の製造時に必要あれば使用されるものと同じものでよく、該ビニル系重合性基含有シラン化合物の量が０．１％未満のばあいには、ビニル系単量体（ｂ−２）のグラフトする割合が低下し、１０％をこえるばあいには、ラテックスの安定性が低くなる傾向にある。
【００５４】
なお、ポリオルガノシロキサン粒子の存在下でのビニル系単量体（ｂ−２）の重合では、グラフト共重合体の枝にあたる部分（ここでは、ビニル系単量体（ｂ−２）の重合体）が幹成分（ここではポリオルガノシロキサン粒子（ｂ−１））にグラフトせずに枝成分だけで単独に重合してえられるいわゆるフリーポリマーも副生し、グラフト共重合体とフリーポリマーの混合物としてえられるが、本発明においてはこの両者を併せてグラフト共重合体という。
【００５５】
乳化重合によってえられたグラフト共重合体からなる難燃剤は、ラテックスのまま使用してもよいが、適用範囲が広いことから、ラテックスからポリマーを分離して粉体として使用することが好ましい。ポリマーを分離する方法としては、通常の方法、たとえばラテックスに塩化カルシウム、塩化マグネシウム、硫酸マグネシウムなどの金属塩を添加することによりラテックスを凝固、分離、水洗、脱水し、乾燥する方法があげられる。また、スプレー乾燥法も使用できる。
【００５６】
かくして難燃剤として使用されるポリオルガノシロキサン含有グラフト共重合体（Ｂ）は得られる。
【００５７】
前記フッ素系樹脂（Ｃ）は、フッ素原子を有する重合体樹脂であり、燃焼時の滴下防止剤として使用される成分である。滴下防止効果が大きい点で好ましい具体例としては、ポリモノフルオロエチレン、ポリジフルオロエチレン、ポリトリフルオロエチレン、ポリテトラフルオロエチレン、テトラフルオロエチレン／ヘキサフルオロエチレン共重合体などのフッ素化ポリオレフィン樹脂、ポリフッ化ビニリデン樹脂などをあげることができる。さらに、フッ素化ポリオレフィン樹脂が好ましく、とくに平均粒子径が７００μｍ以下のフッ素化ポリオレフィン樹脂が好ましい。ここでいう平均粒子径とフッ素化ポリオレフィン樹脂の一次粒子が凝集して形成される二次粒子の平均粒子径をいう。さらにフッ素化ポリオレフィン樹脂で好ましくは、密度と嵩密度の比（密度／嵩密度）が６．０以下のフッ素化ポリオレフィン樹脂である。ここでいう密度と嵩密度とはＪＩＳ−Ｋ６８９１に記載されている方法にて測定したものである。フッ素系樹脂（Ｃ）は、単独で用いてもよく、２種以上を組み合わせて用いてもよい。
【００５８】
前記酸化防止剤（Ｄ）は、本発明においては、成形時の樹脂の酸化分解を抑制することを目的とするだけでなく、難燃性を向上させることも目的とする成分である。酸化防止剤は、通常の成形時に使用されるものであれば、特に限定されない。具体例としては、トリス［Ｎ−（３，５−ジ−ｔ−ブチル−４−ヒドロキシベンジル）］イソシアヌレート（旭電化株式会社製、アデカスタブＡＯ−２０など）、テトラキス［３−（３，５−ジ−ｔ−ブチル−４−ヒドロキシフェニル）プロピオニルオキシメチル］メタン（チバ・スペシャルティ・ケミカルズ社製、イルガノックス１０１０など）、ブチリデン−１，１−ビス−（２−メチル−４−ヒドロキシ−５−ｔ−ブチル−フェニル）（旭電化株式会社製、アデカスタブＡＯ−４０など）、１，１，３−トリス（２−メチル−４−ヒドロキシ−５−ｔ−ブチルフェニル）ブタン（吉冨ファインケミカル株式会社製、ヨシノックス９３０など）などのフェノール系酸化防止剤、ビス（２，６，ジ−ｔ−ブチル−４−メチルフェニル）ペンタエリスリトールホスファイト（旭電化株式会社製、アデカスタブＰＥＰ−３６など）、トリス（２，４−ジ−ｔ−ブチルフェニル）ホスファイト（旭電化株式会社製、アデカスタブ２１１２など）、２，２−メチレンビス（４，６−ジ−ｔ−ブチルフェニル）オクチルホスファイト（旭電化株式会社製、アデカスタブＨＰ−１０など）などのリン系酸化防止剤、ジラウリル３，３’−チオ−ジプロピオネート（吉冨ファインケミカル株式会社製、ヨシノックスＤＬＴＰ）、ジミリスチル３，３’−チオ−ジプロピオネート（吉冨ファインケミカル株式会社製、ヨシノックスＤＭＴＰ）などのイオウ系酸化防止剤などがあげられる。
【００５９】
本発明のポリカーボネート系難燃性樹脂組成物は、前記ポリカーボネート系樹脂（Ａ）１００部に対して、ポリオルガノシロキサン含有グラフト共重合体（Ｂ）１〜４．５部、好ましくは２〜３部、フッ素系樹脂（Ｃ）０．０５〜１部、好ましくは０．１〜０．５部、酸化防止剤（Ｄ）０〜２部、好ましくは０．１〜１部を配合することにより得られる。但し、組成物全量１００％に対して、ケイ素含有量が０．３〜１．５％、好ましくは０．７〜１．４％になるようにポリオルガノシロキサン含有グラフト共重合体の組成を調整する必要がある。ポリオルガノシロキサン含有グラフト共重合体（Ｂ）の使用量が少なすぎると、組成物中のケイ素含有量が少なくなりすぎ難燃性が低下する傾向にあり、また多すぎると組成物中のケイ素含有量が多くなりすぎ、成形加工性が悪くなる傾向にあるばかりでなく、コストアップにつながり市場での価値が低くなる傾向にある。なお、ケイ素含有量の分析的な確認は元素分析法により行なうことができる。また、フッ素系樹脂（Ｃ）の使用量が少なすぎると難燃性が低下する傾向にあり、多すぎると成形体の表面が荒れやすくなる傾向にある。また、酸化防止剤（Ｄ）の使用量が少なすぎると難燃性の向上作用が小さくなり、多すぎると成形性が低下する傾向にある。
【００６０】
本発明のポリカーボネート系難燃性樹脂組成物を製造するための方法は、特に限定はなく、通常の方法が使用できる。たとえば、ヘンシェルミキサー、リボンブレンダー、ロール、押出機、ニーダーなどで混合する方法があげられる。
【００６１】
このとき、通常使用される配合剤、すなわち可塑剤、安定剤、滑剤、紫外線吸収剤、顔料、ガラス繊維、充填剤、高分子加工助剤、高分子滑剤、耐衝撃性改良剤などを配合することができる。高分子加工助剤の好ましい具体例は、メタクリル酸メチル−アクリル酸ブチル共重合体などのメタクリレート系（共）重合体があげられ、耐衝撃性改良剤の好ましい具体例は、ブタジエンゴム系耐衝撃性改良剤（ＭＢＳ樹脂）、アクリル酸ブチルゴム系耐衝撃性改良剤、アクリル酸ブチルゴム／シリコーンゴムの複合ゴム系耐衝撃性改良剤などがあげられる。また、他の難燃剤も併用してもよい。たとえば、併用する難燃剤の好ましい具体例は、トリフェニルホスフェート、縮合リン酸エステル、安定化赤リンなどのリン系化合物、シアヌル酸、シアヌル酸メラミンなどのトリアジン系化合物、酸化ホウ素、ホウ酸亜鉛などのホウ素系化合物などがあげられる。これらの配合剤の好ましい使用量は、効果−コストのバランスの点から熱可塑性樹脂１００部に対して、０．１〜２０部、さらには０．２〜１０部、とくには０．３〜５部である。
【００６２】
えられたポリカーボネート系難燃性樹脂組成物の成形法としては、通常の熱可塑性樹脂組成物の成形に用いられる成形法、すなわち、射出成形法、押出成形法、ブロー成形法、カレンダー成形法などを適用することができる。
【００６３】
本発明のポリカーボネート系難燃性樹脂組成物から得られる成形品の用途としては、特に限定されないが、たとえば、デスクトップ型コンピューター、ノート型コンピューター、タワー型コンピューター、サーバー型コンピューター、プリンター、コピー機、ＦＡＸ機、携帯電話、ＰＨＳ、ＴＶ、ビデオデッキ等の各種ＯＡ／情報／家電機器のハウジングおよびシャーシー部品、各種建材部材および各種自動車部材などの難燃性が必要となる用途があげられる。
【００６４】
【実施例】
本発明を実施例に基づき具体的に説明するが、本発明はこれらのみに限定されない。
【００６５】
なお、以下の実施例および比較例における測定および試験はつぎのように行った。
［重合転化率］
ラテックスを１２０℃の熱風乾燥器で１時間乾燥して固形成分量を求めて、１００×固形成分量／仕込み単量体量（％）で算出した。
［トルエン不溶分量］
ラテックスから乾燥させてえられたポリオルガノシロキサン粒子の固体０．５ｇを室温にてトルエン８０ｍｌに２４時間浸漬し、１２０００ｒｐｍにて６０分間遠心分離してポリオルガノシロキサン粒子のトルエン不溶分の重量分率（％）を測定した。
［グラフト率］
グラフト共重合体１ｇを室温にてアセトン８０ｍｌに４８時間浸漬し、１２０００ｒｐｍにて６０分間遠心分離して求めたグラフト共重合体の不溶分量（ｗ）を求め、次式によりグラフト率を算出した。
【００６６】

［平均粒子径］
ポリオルガノシロキサン粒子およびグラフト共重合体の平均粒子径をラテックスの状態で測定した。測定装置として、リード＆ノースラップインスツルメント（ＬＥＥＤ＆ＮＯＲＴＨＲＵＰ ＩＮＳＴＲＵＭＥＮＴＳ）社製のＭＩＣＲＯＴＲＡＣ ＵＰＡを用いて、光散乱法により数平均粒子径（μｍ）および粒子径分布の変動係数（１００×標準偏差／数平均粒子径）（％）を測定した。
［ケイ素含有量］
仕込みおよび重合転化率から、ポリオルガノシロキサン含有グラフト共重合体中のケイ素含有量を求め、これと配合組成割合から、組成物中のケイ素含有量を求めた。
［耐衝撃性］
ＡＳＴＭ Ｄ−２５６に準じて、ノッチつき１／８インチバーを用いて２３℃でのアイゾット試験により評価した。
［難燃性］
ＵＬ９４ Ｖ試験に準拠した垂直燃焼試験法にて、５サンプルの総燃焼時間を測定して評価した。
［成形加工性］
メルトフローインデックスを２６０℃、５ｋｇ／ｃｍ²荷重で測定し、次の基準で判定した。良い：○、少し悪い：△、悪い：×
（参考例１） ポリオルガノシロキサン粒子（Ｓ−１）の製造
次の成分からなる混合液をホモミキサーにより１００００ｒｐｍで５分間撹拌してエマルジョンを調製した。
【００６７】

このエマルジョンを撹拌機、還流冷却器、窒素吹込口、単量体追加口、温度計を備えた５口フラスコに一括して仕込んだ。系を撹拌しながら、１０％ドデシルベンゼンスルホン酸（ＤＢＳＡ）水溶液１部（固形分）を添加し、８０℃に約４０分かけて昇温後、８０℃で６時間反応させた。その後、２５℃に冷却して、２０時間放置後、系のｐＨを水酸化ナトリウムで６．８に戻して重合を終了し、ポリオルガノシロキサン粒子（Ｓ−１）を含むラテックスをえた。重合転化率、ポリオルガノシロキサン粒子のラテックスの平均粒子径およびトルエン不溶分量を測定し、結果を表１に示す。
【００６８】
（参考例２） ポリオルガノシロキサン粒子（Ｓ−２）の製造
撹拌機、還流冷却器、チッ素吹込口、単量体追加口、温度計を備えた５口フラスコに、

を仕込んだ。
つぎに、系をチッ素置換しながら７０℃に昇温し、純水１部と過硫酸カリウム（ＫＰＳ）０．０２部からなる水溶液を添加してから、つづいて

からなる混合液を一括添加して、１時間撹拌して重合を完結させて、Ｓｔ−ＢＭＡ共重合体のラテックスをえた。重合転化率は９９％であった。えられたラテックスの固形分含有率は１．０％、平均粒子径０．０１μｍであった。また、このときの変動係数は３８％であった。Ｓｔ−ＢＭＡ共重合体の溶剤不溶分量は０％であった。
【００６９】
別途、つぎの成分からなる混合物をホモミキサーで１００００ｒｐｍで５分間撹拌してポリオルガノシロキサン形成成分のエマルジョンを調製した。
【００７０】

つづいて、Ｓｔ−ＢＭＡ共重合体を含むラテックスを８０℃に保ち、系に１０％ＤＢＳＡ水溶液２部（固形分）を添加したのち、上記ポリオルガノシロキサン形成成分のエマルジョンを一括で添加した後６時間撹拌を続けたのち、２５℃に冷却して２０時間放置した。その後、水酸化ナトリウムでｐＨを６．６にして重合を終了し、ポリオルガノシロキサン粒子（Ｓ−２）を含むラテックスをえた。重合転化率、ポリオルガノシロキサン粒子のラテックスの平均粒子径およびトルエン不溶分量を測定し、結果を表１に示す。該ポリオルガノシロキサン粒子を含むラテックス中のポリオルガノシロキサン粒子は仕込み量および転化率かポリオルガノシロキサン成分９８％およびＳｔ−ＢＭＡ共重合体成分２％からなる。
【００７１】
【表１】

（参考例３〜７）
撹拌機、還流冷却器、窒素吹込口、単量体追加口および温度計を備えた５口フラスコに、純水３００部、ナトリウムホルムアルデヒドスルホキシレート（ＳＦＳ）０．２部、エチレンジアミン４酢酸２ナトリウム（ＥＤＴＡ）０．０１部、硫酸第一鉄０．００２５部および表２に示されるポリオルガノシロキサン粒子を仕込み、系を撹拌しながら窒素気流下に６０℃まで昇温させた。６０℃到達後、表２に示される単量体とラジカル重合開始剤の混合物を、表２に示すように１段階または２段階で４時間かけて滴下添加したのち、６０℃で１時間撹拌を続けることによってグラフト共重合体のラテックスをえた。
【００７２】
つづいて、ラテックスを純水で希釈し、固形分濃度を１５％にしたのち、１０％塩化カルシウム水溶液２部（固形分）を添加して、凝固スラリーを得た。凝固凝固スラリーを８０℃まで加熱したのち、５０℃まで冷却して脱水後、乾燥させてポリオルガノシロキサン含有グラフト共重合体（ＳＧ−１〜ＳＧ−５）の粉体をえた。重合転化率、平均粒子径、グラフト率を表２に示す。
【００７３】
なお、表２の中のＭＭＡはメタクリル酸メチル、ＡＮはアクリロニトリル（以上、単量体）、ＣＨＰはクメンハイドロパーオキサイド（ラジカル重合開始剤）、ＳＰは明細書記載の方法で求めた溶解度パラメーターをそれぞれ示す。
【００７４】
【表２】

（実施例１〜６および比較例１〜７）
ポリカーボネート樹脂の難燃化
ポリカーボネート樹脂（ＰＣ：出光石油化学株式会社製タフロンＡ−２２００、粘度平均分子量２２０００）、参考例３〜７で得られたポリオルガノシロキサン含有グラフト共重合体（ＳＧ−１〜ＳＧ−５）、ＰＴＦＥ（ポリテトラフルオロエチレン：ダイキン工業株式会社製ポリフロンＦＡ−５００）および酸化防止剤（ＡＯ−３０：旭電化株式会社製アデカスタブＡＯ−３０、ＨＰ−１０：旭電化製株式会社アデカスタブＨＰ−１０）を用いて表３に示す組成で配合した。
【００７５】
えられた配合物を２軸押出機（日本製鋼所株式会社製 ＴＥＸ４４ＳＳ）で２８０℃にて溶融混錬し、ペレットを製造した。えられたペレットをシリンダー温度２７０℃に設定した株式会社ファナック（ＦＡＮＵＣ）製のＦＡＳ１００Ｂ射出成形機で１／８インチのアイゾット試験片および１／１６インチ難燃性評価用試験片を作成した。えられた試験片を用いて前記評価方法に従って評価した。
【００７６】
結果を表３に示す。
【００７７】
【表３】

表３から、ポリカーボネート樹脂、ポリオルガノシロキサン含有グラフト共重合体、フッ素系樹脂、酸化防止剤を、全組成物中のケイ素含有量が特定量になるように配合することで難燃性−耐衝撃性−成形加工性バランスの優れたポリカーボネート系難燃性樹脂組成物が得られることがわかる。
【００７８】
（実施例７および比較例８）
ポリカーボネート／ポリエチレンテレフタレート混合樹脂の難燃化
ＰＣ、ポリエチレンテレフタレート樹脂（ＰＥＴ：鐘紡株式会社製ベルペットＥＦＧ−７０）、参考例５で得られたポリオルガノシロキサン含有グラフト共重合体（ＳＧ−３）、ＰＴＦＥおよび酸化防止剤（ＡＯ−３０：旭電化株式会社製アデカスタブＡＯ−３０）を用いて表４に示す組成で配合した。
【００７９】
えられた配合物を２軸押出機（日本製鋼所株式会社製 ＴＥＸ４４ＳＳ）で２６０℃にて溶融混錬し、ペレットを製造した。えられたペレットをシリンダー温度２６０℃に設定した株式会社ファナック（ＦＡＮＵＣ）製のＦＡＳ１００Ｂ射出成形機で１／８インチのアイゾット試験片および１／１２インチ難燃性評価用試験片を作成した。えられた試験片を用いて前記評価方法に従って評価した。
【００８０】
結果を表４に示す。
【００８１】
【表４】

表４から、ポリカーボネート／ポリエチレンテレフタレート混合樹脂、ポリオルガノシロキサン含有グラフト共重合体、フッ素系樹脂、酸化防止剤を、全組成物中のケイ素含有量が特定量になるように配合することで難燃性−耐衝撃性−成形加工性バランスの優れたポリカーボネート系難燃性樹脂組成物が得られることがわかる。
【００８２】
【発明の効果】
本発明により、非ハロゲンで、且つ、非リン系難燃剤を用いて、難燃性−耐衝撃性−成形加工性のバランスに優れたポリカーボネート系難燃性樹脂組成物をうることができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a polycarbonate-based flame retardant resin composition.
[0002]
[Prior art]
Polycarbonate resins are widely used as electric / electronic parts, OA equipment, household goods or building materials due to their excellent impact resistance, heat resistance, electrical characteristics, and the like. Polycarbonate resins have higher flame retardancy than polystyrene resins, but the fields requiring high flame retardancy, mainly in fields such as electrical / electronic parts and office automation equipment, remain unchanged. However, the flame retardancy is insufficient, and the improvement is achieved by adding various flame retardants. For example, organic halogen compounds and organophosphorus compounds have been widely added. However, many of the organic halogen compounds and organic phosphorus compounds have a problem in terms of toxicity. In particular, the organic halogen compounds have a problem of generating corrosive gas during combustion. For these reasons, in recent years, there has been an increasing demand for flame retardancy using non-halogen / non-phosphorus flame retardants.
[0003]
As a non-halogen / non-phosphorus flame retardant, use of a polyorganosiloxane compound (also called silicone) has been proposed. For example, JP-A-54-36365 describes that a flame retardant resin can be obtained by kneading a silicone resin made of monoorganopolysiloxane with a polycarbonate resin.
[0004]
Recently, a polyorganosiloxane-containing graft copolymer has attracted attention because it has a higher flame retardancy-imparting effect than the silicone resin and the like. For example, Japanese Patent Laid-Open No. 2000-17029 discloses a composite rubber flame retardant obtained by graft-polymerizing a vinyl monomer to a composite rubber composed of a polyorganosiloxane rubber and a polyalkyl (meth) acrylate rubber in a polycarbonate resin. It is described that a polycarbonate-based flame retardant resin composition can be obtained.
[0005]
JP-A-2000-226420 discloses that a polyorganosiloxane flame retardant obtained by grafting a vinyl monomer to a composite particle of a polyorganosiloxane having an aromatic group and a vinyl polymer is added to a polycarbonate resin. Describes that a polycarbonate flame-retardant resin composition can be obtained.
[0006]
Japanese Patent Application Laid-Open No. 2000-264935 discloses that a polycarbonate-based flame retardant is obtained by blending a polycarbonate resin with a polyorganosiloxane-containing graft copolymer obtained by graft-polymerizing a vinyl monomer to 0.2 μm or less polyorganosiloxane particles. It is described that a conductive resin composition can be obtained.
[0007]
[Problems to be solved by the invention]
However, in the polycarbonate flame retardant resin composition described in the above publication, high flame retardancy cannot be obtained unless 5 parts by weight or more of the polyorganosiloxane-containing graft copolymer is added to 100 parts by weight of the polycarbonate resin. For this reason, there has been a problem that the use of a large amount of the polyorganosiloxane-containing graft copolymer increases the cost of the flame retardant composition and also deteriorates the moldability.
[0008]
[Means for Solving the Problems]
As a result of intensive studies on the above problems, the present inventors have found that in a resin composition comprising a polycarbonate resin, a polyorganosiloxane-containing graft copolymer, a fluorine resin, and an antioxidant, silicon in the resin composition If the content is set to a specific amount, the amount of the polyorganosiloxane-containing graft copolymer is less than the conventional amount and exhibits high flame retardancy, which is advantageous in terms of cost and moldability. The inventors have found that a composition can be obtained and have completed the present invention.
[0009]
That is, the present invention
(A) 100 parts by weight of polycarbonate-based resin, (B) polyorganosiloxane-containing graft copolymer obtained by polymerizing vinyl monomer (b-2) in the presence of polyorganosiloxane particles (b-1) 1 to 4.5 parts by weight, (C) a fluororesin 0.05 to 1 part by weight, and (D) an antioxidant 0 to 2 parts by weight, the total amount of the resin composition being 100% by weight Polycarbonate flame retardant resin composition having a silicon content of 0.3 to 1.5% by weight based on
The polycarbonate-based flame-retardant resin composition according to claim 1, wherein the polyorganosiloxane particles (b-1) have an average particle size of 0.008 to 0.6 μm.
The polycarbonate-based flame retardant resin composition according to claim 1 or 2, wherein the coefficient of variation of the polyorganosiloxane particles is 10 to 70% (claim 3),
In the presence of 40 to 90% by weight of the polyorganosiloxane particles (b-1), the polyorganosiloxane-containing graft copolymer contains 60 to 10% by weight (100% by weight in total) of the vinyl monomer (b-2). A polycarbonate-based flame retardant resin composition according to claim 1 or 2, which is a graft copolymer obtained by polymerization (claim 4),
The polycarbonate-based flame-retardant resin composition (claim 5), wherein the polyorganosiloxane particles (b-1) are in a latex form.
The vinyl monomer (b-2) has a solubility parameter of 9.15 to 10.15 (cal / cm) of the polymer of the vinyl monomer. ^Three ) ^1/2 The polycarbonate-based flame-retardant resin composition according to claim 1 (claim 6) and
The vinyl monomer (b-2) is selected from the group consisting of aromatic vinyl monomers, vinyl cyanide monomers, (meth) acrylic acid ester monomers, and carboxyl group-containing vinyl monomers. 6. The polycarbonate-based flame retardant resin composition according to claim 1, 2, 4 or 5, which is at least one selected monomer.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
The polycarbonate flame retardant resin composition of the present invention comprises (A) 100 parts by weight of a polycarbonate resin (parts by weight, the same applies hereinafter) and (B) a vinyl monomer in the presence of polyorganosiloxane particles (b-1). From 1 to 4.5 parts of a polyorganosiloxane-containing graft copolymer obtained by polymerizing (b-2), (C) 0.05 to 1 part of a fluororesin, and (D) 0 to 2 parts of an antioxidant. And the silicon content is 0.3 to 1.5% with respect to 100% (weight%, hereinafter the same) of the total resin composition.
[0011]
The polycarbonate resin (A) of the present invention includes a mixed resin composition containing 50% or more, more preferably 70% or more of polycarbonate.
Preferred specific examples of the polycarbonate-based resin (A) include polycarbonate, polycarbonate / polyethylene terephthalate mixed resin, and polycarbonate / polybutylene terephthalate mixed resin from the viewpoints of economical aspect and good balance between flame retardancy and impact resistance. Polycarbonate / polyester mixed resin, polycarbonate / acrylonitrile-styrene copolymer mixed resin, polycarbonate / butadiene rubber-styrene copolymer (HIPS resin) mixed resin, polycarbonate / acrylonitrile-butadiene rubber-styrene copolymer (ABS resin) mixed Resin, polycarbonate / acrylonitrile-butadiene rubber-α-methylstyrene copolymer mixed resin, polycarbonate / styrene-butadiene rubber-acrylonitrile N- phenylmaleimide copolymer mixed resins, polycarbonate / acrylonitrile - acrylic rubber - styrene copolymer (AAS resin) mixed resins. Further, the mixed resins may be further mixed and used. Further, the viscosity average molecular weight of the polycarbonate used for the polycarbonate resin and the mixed resin containing the polycarbonate is preferably 10,000 to 50,000, more preferably 15,000 to 25,000 from the viewpoint of moldability.
[0012]
The polyorganosiloxane-containing graft copolymer (B) is a component used as a flame retardant, and is obtained by polymerizing a vinyl monomer (b-2) in the presence of polyorganosiloxane particles (b-1). It is done.
[0013]
The polyorganosiloxane particles (b-1) used in the polyorganosiloxane-containing graft copolymer (B) have an average particle size determined from light scattering or electron microscope observation from the viewpoint of flame retardancy. Is 0.008 to 0.6 μm, more preferably 0.008 to 0.2 μm, further 0.01 to 0.15 μm, and particularly preferably 0.01 to 0.1 μm. It tends to be difficult to obtain particles having an average particle size of less than 0.008 μm. When the average particle size exceeds 0.6 μm, the flame retardancy tends to deteriorate. The variation coefficient (100 × standard deviation / average particle size) (%) of the particle size distribution of the polyorganosiloxane particles is preferable in that the molded product surface appearance of the resin composition containing the flame retardant of the present invention is good. Is preferably 10 to 70%, more preferably 20 to 60%, and particularly preferably 20 to 50%.
[0014]
In the present invention, the polyorganosiloxane particles (b-1) are not only particles comprising only polyorganosiloxane but also modified polyorganosiloxanes containing 5% or less of other (co) polymers. Good. That is, the polyorganosiloxane particles may contain, for example, 5% or less of polybutyl acrylate, butyl acrylate-styrene copolymer, and the like.
[0015]
Specific examples of the polyorganosiloxane particles (b-1) include polydimethylsiloxane particles, polymethylphenylsiloxane particles, and dimethylsiloxane-diphenylsiloxane copolymer particles. These may be used alone or in combination of two or more.
[0016]
The polyorganosiloxane particles (b-1) are composed of, for example, an organosiloxane and / or a bifunctional silane compound, a vinyl polymerizable group-containing silane compound, and a trifunctional or higher functional silane compound used as necessary. It can be obtained by polymerizing the polyorganosiloxane-forming component.
[0017]
The organosiloxane and / or the bifunctional silane compound are components constituting the main skeleton of the polyorganosiloxane chain. Specific examples of the organosiloxane include hexamethylcyclotrisiloxane (D3) and octamethylcyclotetrasiloxane. Specific examples of bifunctional silane compounds such as (D4), decamethylcyclopentasiloxane (D5), dodecamethylcyclohexasiloxane (D6), tetradecamethylcycloheptasiloxane (D7), hexadecamethylcyclooctasiloxane (D8) As diethoxydimethylsilane, dimethoxydimethylsilane, diphenyldimethoxysilane, diphenyldiethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, Data heptadecafluorodecyl methyldimethoxysilane, trifluoropropyl methyl dimethoxy silane, octadecyl methyl dimethoxysilane and the like. Among these, D4 or a mixture of D3 to D7 or a mixture of D3 to D8 is contained in an amount of 70 to 100%, more preferably 80 to 100% in view of good economic efficiency and flame retardancy, and the remaining component is diphenyl. Those containing 0 to 30%, further 0 to 20% of dimethoxysilane, diphenyldiethoxysilane and the like are preferably used.
[0018]
The vinyl polymerizable group-containing silane compound is copolymerized with the organosiloxane, bifunctional silane compound, trifunctional or higher functional silane compound, etc., and introduces a vinyl polymerizable group into the side chain or terminal of the copolymer. This vinyl polymerizable group acts as a graft active site when chemically bonding to a vinyl (co) polymer formed from a vinyl monomer (b-2) described later. Furthermore, it is a component that can be used as a crosslinking agent because it can form a cross-linking bond by radical reaction between graft active sites with a radical polymerization initiator. At this time, the same radical polymerization initiator as that which can be used in the graft polymerization described later can be used. Even when the crosslinking is carried out by radical reaction, grafting is possible because a part remains as a graft active site.
[0019]
Specific examples of the vinyl polymerizable group-containing silane compound include, for example, γ-methacryloyloxypropyldimethoxymethylsilane, γ-methacryloyloxypropyltrimethoxysilane, γ-methacryloyloxypropyltriethoxysilane, and γ-methacryloyloxypropyldisilane. (Meth) acryloyloxy group-containing silane compounds such as ethoxymethylsilane, γ-acryloyloxypropyldimethoxymethylsilane, γ-acryloyloxypropyltrimethoxysilane, p-vinylphenyldimethoxymethylsilane, p-vinylphenyltrimethoxysilane, etc. Vinylphenyl group-containing silane compounds, vinylmethyldimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane and other vinyl group-containing silane compounds, DOO trimethoxysilane, mercapto group-containing silane compounds such as mercaptopropyl dimethoxymethyl silane and the like. Among these, a (meth) acryloyloxy group-containing silane compound, a vinyl group-containing silane compound, and a mercapto group-containing silane compound are preferably used from the viewpoint of economy.
[0020]
When the vinyl polymerizable group-containing silane compound is a trialkoxysilane type, it also has the role of a trifunctional or higher functional silane compound as shown below.
[0021]
The trifunctional or higher functional silane compound is copolymerized with the organosiloxane, bifunctional silane compound, vinyl polymerizable group-containing silane compound, and the like to introduce a crosslinked structure into the polyorganosiloxane to impart rubber elasticity. Used as a cross-linking agent for components, ie polyorganosiloxanes. Specific examples include tetraethoxysilane, methyltriethoxysilane, methyltrimethoxysilane, ethyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, heptadecafluorodecyltrimethoxysilane, trifluoropropyltrimethoxysilane, octadecyl. Examples thereof include tetrafunctional and trifunctional alkoxysilane compounds such as trimethoxysilane. Among these, tetraethoxysilane and methyltriethoxysilane are preferably used from the viewpoint of high crosslinking efficiency.
[0022]
The proportion of the organosiloxane, bifunctional silane compound, vinyl polymerizable group-containing silane compound, and trifunctional or higher functional silane compound used during polymerization is usually an organosiloxane and / or a bifunctional silane compound (organosiloxane and bifunctional). The ratio with the silane compound is usually 100/0 to 0/100, more preferably 100/0 to 70/30) 50 to 99.9%, further 60 to 99%, vinyl-based polymerizable group-containing silane. The compound is preferably 0 to 40%, more preferably 0.5 to 30%, trifunctional or higher functional silane compound 0 to 50%, and further preferably 0.5 to 39%. The vinyl polymerizable group-containing silane compound and the trifunctional or higher functional silane compound do not simultaneously become 0%, and any of them is preferably used in an amount of 0.1% or more.
[0023]
When the use ratio of the organosiloxane and the bifunctional silane compound is too small, the resin composition obtained by blending tends to become brittle. When the amount is too large, the amount of the vinyl polymerizable group-containing silane compound and the trifunctional or higher functional silane compound is too small, and the effect of using these tends to be difficult to be exhibited. In addition, when the proportion of the vinyl polymerizable group-containing silane compound or the trifunctional or higher functional silane compound is too small, the effect of flame retardancy is reduced, and when the proportion is too large, The resin composition obtained by blending tends to be brittle.
[0024]
The polyorganosiloxane particles (b-1) are composed of, for example, the organosiloxane and / or a bifunctional silane compound, a vinyl polymerizable group-containing silane compound, and a trifunctional or higher functional silane compound used as necessary. It is preferable to produce the polyorganosiloxane-forming component by emulsion polymerization.
[0025]
The emulsion polymerization can be carried out, for example, by emulsifying and dispersing the polyorganosiloxane-forming component and water in water in the presence of an emulsifier to form an acidic state. In this case, when the emulsion droplets of several μm or more are prepared by mechanical shearing, the average particle diameter of the polyorganosiloxane particles obtained after polymerization is in the range of 0.02 to 0.6 μm depending on the amount of the emulsifier used. Can be controlled. In addition, a coefficient of variation (100 × standard deviation / average particle size) (%) of the obtained particle size distribution can be 20 to 70%.
[0026]
Further, when producing polyorganosiloxane particles having a narrow particle size distribution of 0.1 μm or less, it is preferable to perform polymerization in multiple stages. For example, 1 to 20% of an emulsion composed of emulsion droplets of several μm or more obtained by emulsifying the polyorganosiloxane-forming component, water and an emulsifier by mechanical shearing is first obtained by emulsion polymerization in an acidic state. Polymerization is carried out by adding the remaining emulsion in the presence of the polyorganosiloxane particles as seeds. The polyorganosiloxane particles thus obtained can be controlled to have an average particle size of 0.02 to 0.1 μm and a particle size distribution variation coefficient of 10 to 60% depending on the amount of the emulsifier. A more preferred method is that in the multi-stage polymerization, a vinyl monomer (for example, styrene, butyl acrylate, methyl methacrylate, etc.) used in the graft polymerization described later is used in place of the polyorganosiloxane particle seed in the usual emulsion polymerization method. When the same multistage polymerization is carried out using a vinyl-based (co) polymer obtained by (co) polymerization, the average particle diameter of the resulting polyorganosiloxane (modified polyorganosiloxane) particles is 0.008 to The variation coefficient of the particle size distribution can be controlled to 10 to 50% at 0.1 μm.
[0027]
The emulsified liquid droplets of several μm or more can be prepared by using a high-speed stirrer such as a homomixer.
[0028]
In the emulsion polymerization, an emulsifier that does not lose emulsification ability under an acidic state is used. Specific examples include alkylbenzene sulfonic acid, sodium alkylbenzene sulfonate, alkyl sulfonic acid, sodium alkyl sulfonate, sodium (di) alkyl sulfosuccinate, sodium polyoxyethylene nonylphenyl ether sulfonate, sodium alkyl sulfate, and the like. These may be used alone or in combination of two or more. Among these, alkylbenzene sulfonic acid, sodium alkylbenzene sulfonate, alkyl sulfonic acid, sodium alkyl sulfonate, and sodium (di) alkyl sulfosuccinate are preferable because the emulsion has a relatively high emulsion stability. Furthermore, alkylbenzene sulfonic acid and alkyl sulfonic acid are particularly preferable because they also act as a polymerization catalyst for the polyorganosiloxane-forming component.
[0029]
The acidic state can be obtained by adding inorganic acids such as sulfuric acid and hydrochloric acid and organic acids such as alkylbenzene sulfonic acid, alkyl sulfonic acid, and trifluoroacetic acid to the system. The pH does not corrode production equipment and has an appropriate polymerization rate. It is preferable to adjust to 1-3 at the point that it is obtained, and it is more preferable to adjust to 1.0-2.5 further.
[0030]
The heating for the polymerization is preferably 60 to 120 ° C, more preferably 70 to 100 ° C in that an appropriate polymerization rate can be obtained.
[0031]
In an acidic state, the Si-O-Si bond forming the polyorganosiloxane skeleton is in an equilibrium state of cleavage and formation, and this equilibrium changes depending on the temperature, so that the polyorganosiloxane chain is stabilized. Furthermore, it is preferable to neutralize by adding an alkaline aqueous solution such as sodium hydroxide, potassium hydroxide, sodium carbonate or the like. Furthermore, since the equilibrium is more likely to be generated with a high molecular weight or a high degree of cross-linking on the production side as the temperature becomes lower, in order to obtain a high molecular weight or a high degree of cross-linking, the polymerization of the polyorganosiloxane-forming component must be performed. It is preferable to neutralize after performing at above ° C and then cooling to below room temperature and holding for about 5 to 100 hours.
[0032]
Thus, when the resulting polyorganosiloxane particles are formed from, for example, an organosiloxane and / or a bifunctional silane compound or a vinyl polymerizable group-containing silane compound, they are usually randomly copolymerized and vinyl polymerized. It becomes a polymer having a functional group. Further, when a trifunctional or higher functional silane compound is copolymerized, it has a crosslinked network structure. Further, when the vinyl polymerizable groups are crosslinked by a radical reaction with a radical polymerization initiator as used in graft polymerization described later, the polymer has a crosslinked structure in which the vinyl polymerizable groups are chemically bonded. Some unreacted vinyl polymerizable groups remain. The toluene insoluble content of the polyorganosiloxane particles (the amount of toluene insoluble when 0.5 g of the particles are immersed in 80 ml of toluene at room temperature for 24 hours) is preferably 95% or less and 90% or less from the viewpoint of flame retardancy. More preferred.
[0033]
A flame retardant comprising a polyorganosiloxane-containing graft copolymer can be obtained by graft polymerization of the vinyl monomer (b-2) to the polyorganosiloxane particles obtained by the above process.
[0034]
The flame retardant has a structure in which a vinyl monomer (b-2) is grafted to the polyorganosiloxane particles, and the graft ratio is 5 to 150%, more preferably 15 to 120%. This is preferable from the viewpoint of a good balance between flame resistance and impact resistance.
[0035]
The vinyl monomer (b-2) is a component used to obtain a flame retardant comprising a polyorganosiloxane-containing graft copolymer, and further, the flame retardant is blended in a thermoplastic resin. When imparting flame retardancy, it is also a component used to ensure the compatibility between the flame retardant and the thermoplastic resin and to uniformly disperse the flame retardant in the thermoplastic resin. Therefore, the vinyl monomer (b-2) has a solubility parameter of 9.15 to 10.15 ((cal / cm ^Three ) ^1/2 In the following, it is preferable that the unit is selected to be 9.17 to 10.10, particularly 9.20 to 10.05. When the solubility parameter is out of the above range, the flame retardancy tends to decrease.
[0036]
The solubility parameter is a value calculated using the group parameter of Small by the group contribution method described in “Polymer Handbook”, 1999, 4th edition, section VII, pages 682 to 685, published by John Wiley & Son. For example, polymethyl methacrylate (repeating unit molecular weight 100 g / mol, density = 1.19 g / cm ^Three (Hereinafter, unit omitted) 9.25, polybutyl acrylate (as 128, 1.06) 8.97, polybutyl methacrylate (as 142, 1.06) 9.47, polystyrene (as 104) 1.05), 9.03, and polyacrylonitrile (as 53, 1.18), 12.71. For the density of each polymer, values described in “ULMANN'S ENCYCLOPEDIA OF INDUSTRIAL CHEMISTRY” 1992, Vol. A21, page 169, published by VCH, Inc. were used. As the solubility parameter δc of the copolymer, the value of the main component is used when the weight fraction is less than 5%, and the additivity is established by the weight fraction when the weight fraction is 5% or more. That is, it can be calculated by the formula (1) from the solubility parameter δn of the homopolymer of each vinyl monomer constituting the copolymer composed of m kinds of vinyl monomers and its weight fraction Wn.
[0037]
[Expression 1]

For example, the solubility parameter of a copolymer composed of 75% styrene and 25% acrylonitrile is substituted into the formula (1) using the solubility parameter 9.03 of polystyrene and the solubility parameter 12.71 of polyacrylonitrile, and is 9.95. The value of is obtained.
[0038]
Further, the solubility parameter δs of the vinyl polymer obtained by polymerizing the vinyl monomer in two or more stages and changing the kind of the vinyl monomer in each stage is the vinyl polymer finally obtained. It was assumed that the additivity was established by the value obtained by dividing the total weight of the polymer by the weight of the vinyl polymer obtained in each stage, that is, the weight fraction. That is, it can be calculated by the equation (2) from the solubility parameter δi of the polymer obtained at each step and the weight fraction Wi obtained at each step.
[0039]
[Expression 2]

For example, if polymerization is performed in two stages and 50 parts of a copolymer composed of 75% styrene and 25% acrylonitrile is obtained in the first stage, and 50 parts of a polymer of methyl methacrylate is obtained in the second stage. The solubility parameter of the polymer obtained in the step polymerization was calculated by using the solubility parameter 9.95 of the styrene (75%)-acrylonitrile (25%) copolymer and the solubility parameter 9.25 of polymethyl methacrylate. Substituting into 2) gives a value of 9.60.
[0040]
The vinyl monomer (b-2) is used in an amount of 40 to 90%, more preferably 50 to 80%, particularly 50 to 75% of the polyorganosiloxane particles (b-1). % Is preferably 60 to 10%, more preferably 50 to 20%, and particularly preferably 50 to 25%.
[0041]
When the amount of the vinyl monomer (b-2) used is too much or too little, in any case, the flame retardancy tends to be insufficient.
[0042]
Examples of the vinyl monomer (b-2) include aromatic vinyl monomers such as styrene, α-methyl styrene, paramethyl styrene and parabutyl styrene, and vinyl cyanide monomers such as acrylonitrile and methacrylonitrile. Monomer, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, glycidyl acrylate, hydroxyethyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, methacrylic acid (Meth) acrylic acid ester monomers such as lauryl, glycidyl methacrylate, and hydroxyethyl methacrylate; carboxyl group-containing vinyl monomers such as itaconic acid, (meth) acrylic acid, fumaric acid, and maleic acid It is done. As described above, these may be used alone or in combination of two or more as long as the solubility parameter of the polymer falls within the range described above.
[0043]
As the graft polymerization, normal seed emulsion polymerization can be applied, and the vinyl monomer (b-2) may be radically polymerized in the latex of the polyorganosiloxane particles (b-1). Further, the vinyl monomer (b-2) may be polymerized in one stage or may be polymerized in two or more stages.
[0044]
The radical polymerization can be carried out without any particular limitation, such as a method of allowing the reaction to proceed by thermally decomposing a radical polymerization initiator, or a redox reaction using a reducing agent.
[0045]
Specific examples of the radical polymerization initiator include cumene hydroperoxide, t-butyl hydroperoxide, benzoyl peroxide, t-butyl peroxyisopropyl carbonate, di-t-butyl peroxide, t-butyl peroxylaurate, Organic peroxides such as lauroyl peroxide, succinic acid peroxide, cyclohexanenon peroxide, acetylacetone peroxide, inorganic peroxides such as potassium persulfate and ammonium persulfate, 2,2′-azobisisobutyronitrile, 2 , 2′-azobis-2,4-dimethylvaleronitrile, and other azo compounds. Of these, organic peroxides or inorganic peroxides are particularly preferred because of their high reactivity.
[0046]
The reducing agent used in the redox system is ferrous sulfate / glucose / sodium pyrophosphate, ferrous sulfate / dextrose / sodium pyrophosphate, or ferrous sulfate / sodium formaldehyde sulfoxylate / ethylenedieamine. Examples thereof include a mixture of acetate.
[0047]
The amount of the radical polymerization initiator used is usually from 0.005 to 20 parts, more preferably from 0.01 to 10 parts, especially 0, based on 100 parts of the polyorganosiloxane particles (b-1) used. 0.03 to 5 parts are preferred. When the amount of the radical polymerization initiator is less than 0.005 part, the reaction rate tends to be low and the production efficiency tends to be deteriorated. is there.
[0048]
Moreover, a chain transfer agent can also be used if required in radical polymerization. The chain transfer agent is not particularly limited as long as it is used in ordinary emulsion polymerization.
[0049]
Specific examples of the chain transfer agent include t-dodecyl mercaptan, n-octyl mercaptan, n-tetradecyl mercaptan, n-hexyl mercaptan and the like.
[0050]
The chain transfer agent is an optional component, but when used, the amount used is preferably 0.01 to 5 parts with respect to 100 parts of the vinyl monomer (b-2). When the amount of the chain transfer agent is less than 0.01 part, the effect used cannot be obtained, and when it exceeds 5 parts, the polymerization rate tends to be low and the production efficiency tends to be low.
[0051]
Moreover, it is preferable that the reaction temperature at the time of superposition | polymerization is 30-120 degreeC normally.
[0052]
In the polymerization, when the polyorganosiloxane particles (b-1) contain a vinyl polymerizable group, the polyorganosiloxane is polymerized when the vinyl monomer (b-2) is polymerized by the radical polymerization initiator. A graft is formed by reacting with the vinyl polymerizable group of the particles (b-1). When a vinyl polymerizable group is not present in the polyorganosiloxane particle (b-1), an organic group such as a methyl group bonded to a silicon atom can be obtained by using a specific radical initiator such as t-butyl peroxylaurate. Hydrogen is extracted from the polymer, and the vinyl monomer (b-2) is polymerized by the generated radicals to form a graft.
[0053]
In addition, 0.1 to 10%, preferably 0.5 to 5% of the vinyl monomer (b-2) is polymerized using a vinyl polymerizable group-containing silane compound, and an acidic state having a pH of 5 or less. Grafts are formed even when the redistribution reaction is performed below. This is because, in the acidic state, the Si—O—Si bond in the main skeleton of the polyorganosiloxane is in an equilibrium state of cleavage and generation. In this equilibrium state, the vinyl monomer and the vinyl polymerizable group-containing silane compound are used. When copolymerized, the side chain silane of the vinyl copolymer produced or produced by polymerization reacts with the polyorganosiloxane chain to form a graft. The vinyl polymerizable group-containing silane compound may be the same as that used if necessary at the time of producing the polyorganosiloxane particles (b-1), and the amount of the vinyl polymerizable group-containing silane compound is 0.00. If it is less than 1%, the grafting ratio of the vinyl monomer (b-2) decreases, and if it exceeds 10%, the stability of the latex tends to be low.
[0054]
In the polymerization of the vinyl monomer (b-2) in the presence of polyorganosiloxane particles, the portion corresponding to the branch of the graft copolymer (here, the polymer of the vinyl monomer (b-2)) ) Is a by-product of a so-called free polymer obtained by polymerizing only the branch component without grafting to the trunk component (here, polyorganosiloxane particles (b-1)), and a mixture of the graft copolymer and the free polymer. However, in the present invention, both are referred to as a graft copolymer.
[0055]
The flame retardant composed of the graft copolymer obtained by emulsion polymerization may be used as it is in latex, but since the application range is wide, it is preferable to separate the polymer from latex and use it as a powder. Examples of the method for separating the polymer include a usual method, for example, a method in which a latex is coagulated, separated, washed with water, dehydrated and dried by adding a metal salt such as calcium chloride, magnesium chloride, magnesium sulfate to the latex. A spray drying method can also be used.
[0056]
Thus, the polyorganosiloxane-containing graft copolymer (B) used as a flame retardant is obtained.
[0057]
The fluororesin (C) is a polymer resin having a fluorine atom, and is a component used as a dripping preventive during combustion. Preferable specific examples from the viewpoint of a large dripping prevention effect include fluorinated polyolefin resins such as polymonofluoroethylene, polydifluoroethylene, polytrifluoroethylene, polytetrafluoroethylene, tetrafluoroethylene / hexafluoroethylene copolymer, and polyfluoride. And vinylidene chloride resin. Further, a fluorinated polyolefin resin is preferable, and a fluorinated polyolefin resin having an average particle diameter of 700 μm or less is particularly preferable. The average particle diameter here refers to the average particle diameter of secondary particles formed by aggregation of primary particles of the fluorinated polyolefin resin. Further, a fluorinated polyolefin resin is preferably a fluorinated polyolefin resin having a density / bulk density ratio (density / bulk density) of 6.0 or less. The density and bulk density here are measured by the method described in JIS-K6891. The fluororesin (C) may be used alone or in combination of two or more.
[0058]
In the present invention, the antioxidant (D) is a component not only for suppressing the oxidative decomposition of the resin during molding but also for improving flame retardancy. The antioxidant is not particularly limited as long as it is used during normal molding. Specific examples include tris [N- (3,5-di-t-butyl-4-hydroxybenzyl)] isocyanurate (Asahi Denka Co., Ltd., ADK STAB AO-20, etc.), tetrakis [3- (3,5 -Di-t-butyl-4-hydroxyphenyl) propionyloxymethyl] methane (Ciba Specialty Chemicals, Irganox 1010, etc.), butylidene-1,1-bis- (2-methyl-4-hydroxy-5) -T-butyl-phenyl) (Asahi Denka Co., Ltd., ADK STAB AO-40, etc.), 1,1,3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane (Yoshihata Fine Chemical Co., Ltd.) Manufactured by Yoshinox 930), etc., and bis (2,6, di-t-butyl-4-methylphenyl) pen Erythritol phosphite (Asahi Denka Co., Ltd., ADK STAB PEP-36), Tris (2,4-di-t-butylphenyl) phosphite (Asahi Denka Co., Ltd., ADK STAB 2112 etc.), 2,2-methylenebis ( Phosphorous antioxidants such as 4,6-di-t-butylphenyl) octyl phosphite (Asahi Denka Co., Ltd., Adeka Stub HP-10, etc.), dilauryl 3,3′-thio-dipropionate (Yoshio Fine Chemical Co., Ltd.) , Yoshinox DLTP) and dimyristyl 3,3′-thio-dipropionate (Yoshinox DMTP, Yoshinox DMTP) and the like.
[0059]
The polycarbonate-based flame retardant resin composition of the present invention is 1 to 4.5 parts, preferably 2 to 3 parts of the polyorganosiloxane-containing graft copolymer (B) with respect to 100 parts of the polycarbonate resin (A). , Fluorinated resin (C) 0.05-1 part, preferably 0.1-0.5 part, antioxidant (D) 0-2 part, preferably 0.1-1 part It is done. However, the composition of the polyorganosiloxane-containing graft copolymer is adjusted so that the silicon content is 0.3 to 1.5%, preferably 0.7 to 1.4% with respect to 100% of the total composition. There is a need to. If the amount of the polyorganosiloxane-containing graft copolymer (B) used is too small, the silicon content in the composition tends to be too low, and the flame retardancy tends to decrease. Not only does the amount increase too much, the moldability tends to deteriorate, but the cost tends to increase and the market value tends to decrease. The analytical confirmation of the silicon content can be performed by elemental analysis. Moreover, when there is too little usage-amount of fluororesin (C), there exists a tendency for a flame retardance to fall, and when too much, it exists in the tendency for the surface of a molded object to become rough easily. Moreover, when there is too little usage-amount of antioxidant (D), an improvement effect of a flame retardance will become small, and when too large, it exists in the tendency for a moldability to fall.
[0060]
The method for producing the polycarbonate flame retardant resin composition of the present invention is not particularly limited, and ordinary methods can be used. For example, there is a method of mixing with a Henschel mixer, a ribbon blender, a roll, an extruder, a kneader or the like.
[0061]
At this time, usually used compounding agents, that is, plasticizer, stabilizer, lubricant, ultraviolet absorber, pigment, glass fiber, filler, polymer processing aid, polymer lubricant, impact resistance improver, etc. be able to. Preferred specific examples of the polymer processing aid include methacrylate (co) polymers such as methyl methacrylate-butyl acrylate copolymer, and preferred specific examples of the impact modifier include butadiene rubber-based impact resistance. Examples thereof include a property improver (MBS resin), a butyl acrylate rubber impact resistance improver, and a butyl acrylate rubber / silicone rubber composite rubber impact impact improver. Moreover, you may use together another flame retardant. For example, preferable specific examples of the flame retardant used in combination include triphenyl phosphate, condensed phosphate ester, phosphorus compound such as stabilized red phosphorus, triazine compound such as cyanuric acid and melamine cyanurate, boron oxide, zinc borate and the like. And boron compounds. The preferred amount of these compounding agents is 0.1 to 20 parts, more preferably 0.2 to 10 parts, especially 0.3 to 5 parts per 100 parts of the thermoplastic resin from the viewpoint of the balance between effect and cost. Part.
[0062]
As a molding method of the obtained polycarbonate-based flame retardant resin composition, a molding method used for molding a normal thermoplastic resin composition, that is, an injection molding method, an extrusion molding method, a blow molding method, a calendar molding method, etc. Can be applied.
[0063]
The use of the molded product obtained from the polycarbonate-based flame retardant resin composition of the present invention is not particularly limited. For example, desktop computers, notebook computers, tower computers, server computers, printers, copiers, FAX Applications that require flame retardancy, such as housings and chassis parts of various OA / information / home appliances such as machines, mobile phones, PHS, TVs, and VCRs, various building materials, and various automobiles.
[0064]
【Example】
The present invention will be specifically described based on examples, but the present invention is not limited thereto.
[0065]
Measurements and tests in the following examples and comparative examples were performed as follows.
[Polymerization conversion rate]
The latex was dried with a hot air dryer at 120 ° C. for 1 hour to determine the amount of solid components, and calculated by 100 × solid component amount / charged monomer amount (%).
[Toluene insoluble content]
0.5 g of solid polyorganosiloxane particles obtained by drying from latex was immersed in 80 ml of toluene at room temperature for 24 hours, centrifuged at 12000 rpm for 60 minutes, and the weight fraction of toluene insolubles in the polyorganosiloxane particles. (%) Was measured.
[Graft ratio]
1 g of the graft copolymer was immersed in 80 ml of acetone at room temperature for 48 hours and centrifuged at 12000 rpm for 60 minutes to determine the insoluble content (w) of the graft copolymer, and the graft ratio was calculated by the following formula.
[0066]

[Average particle size]
The average particle diameter of the polyorganosiloxane particles and the graft copolymer was measured in a latex state. Using a MICROTRAC UPA manufactured by LEED & NORTHRUP INSTRUMENTS as a measuring device, the number average particle size (μm) and the coefficient of variation of particle size distribution (100 × standard deviation / number average) by the light scattering method. Particle diameter) (%) was measured.
[Silicon content]
The silicon content in the polyorganosiloxane-containing graft copolymer was determined from the charge and the polymerization conversion rate, and the silicon content in the composition was determined from this and the composition ratio.
[Shock resistance]
In accordance with ASTM D-256, an Izod test at 23 ° C. was performed using a 1/8 inch bar with a notch.
[Flame retardance]
The total burning time of 5 samples was measured and evaluated by the vertical burning test method based on the UL94 V test.
[Molding processability]
Melt flow index at 260 ° C, 5 kg / cm ² Measured with load and judged according to the following criteria. Good: ○, Slightly bad: △, Bad: ×
Reference Example 1 Production of polyorganosiloxane particles (S-1)
An emulsion was prepared by stirring a mixed solution comprising the following components at 10,000 rpm for 5 minutes with a homomixer.
[0067]

This emulsion was charged all at once into a 5-neck flask equipped with a stirrer, reflux condenser, nitrogen blowing port, monomer addition port, and thermometer. While stirring the system, 1 part (solid content) of a 10% aqueous solution of dodecylbenzenesulfonic acid (DBSA) was added, the temperature was raised to 80 ° C. over about 40 minutes, and the mixture was reacted at 80 ° C. for 6 hours. Thereafter, the mixture was cooled to 25 ° C. and allowed to stand for 20 hours, and then the pH of the system was returned to 6.8 with sodium hydroxide to complete the polymerization, and a latex containing polyorganosiloxane particles (S-1) was obtained. The polymerization conversion rate, the average particle diameter of the latex of the polyorganosiloxane particles and the amount of toluene insolubles were measured, and the results are shown in Table 1.
[0068]
Reference Example 2 Production of polyorganosiloxane particles (S-2)
In a 5-neck flask equipped with a stirrer, reflux condenser, nitrogen inlet, monomer addition port, thermometer,

Was charged.
Next, the temperature was raised to 70 ° C. while replacing the system with nitrogen, and an aqueous solution consisting of 1 part of pure water and 0.02 part of potassium persulfate (KPS) was added.

The mixed solution consisting of the above was added all at once and stirred for 1 hour to complete the polymerization, and a St-BMA copolymer latex was obtained. The polymerization conversion rate was 99%. The obtained latex had a solid content of 1.0% and an average particle size of 0.01 μm. Further, the coefficient of variation at this time was 38%. The solvent-insoluble content of the St-BMA copolymer was 0%.
[0069]
Separately, a mixture of the following components was stirred with a homomixer at 10,000 rpm for 5 minutes to prepare a polyorganosiloxane-forming component emulsion.
[0070]

Subsequently, the latex containing the St-BMA copolymer was kept at 80 ° C., 2 parts of 10% DBSA aqueous solution (solid content) was added to the system, and the emulsion of the polyorganosiloxane forming component was added all at once. After stirring for an hour, the mixture was cooled to 25 ° C. and left for 20 hours. Thereafter, the pH was adjusted to 6.6 with sodium hydroxide to complete the polymerization, and a latex containing polyorganosiloxane particles (S-2) was obtained. The polymerization conversion rate, the average particle diameter of the latex of the polyorganosiloxane particles and the amount of toluene insolubles were measured, and the results are shown in Table 1. The polyorganosiloxane particles in the latex containing the polyorganosiloxane particles consist of the charged amount and the conversion rate of 98% of the polyorganosiloxane component and 2% of the St-BMA copolymer component.
[0071]
[Table 1]

(Reference Examples 3-7)
In a 5-neck flask equipped with a stirrer, reflux condenser, nitrogen inlet, additional monomer port and thermometer, 300 parts pure water, 0.2 part sodium formaldehyde sulfoxylate (SFS), disodium ethylenediaminetetraacetate (EDTA) 0.01 parts, 0.0025 parts of ferrous sulfate and polyorganosiloxane particles shown in Table 2 were charged, and the system was heated to 60 ° C. under a nitrogen stream while stirring the system. After reaching 60 ° C., a mixture of the monomer and radical polymerization initiator shown in Table 2 was added dropwise over 4 hours in one or two steps as shown in Table 2, and then stirred at 60 ° C. for 1 hour. By continuing, a latex of graft copolymer was obtained.
[0072]
Subsequently, the latex was diluted with pure water to a solid content concentration of 15%, and then 2 parts of a 10% calcium chloride aqueous solution (solid content) was added to obtain a coagulated slurry. The coagulated and solidified slurry was heated to 80 ° C., cooled to 50 ° C., dehydrated, and dried to obtain polyorganosiloxane-containing graft copolymers (SG-1 to SG-5). Table 2 shows the polymerization conversion rate, average particle diameter, and graft rate.
[0073]
In Table 2, MMA is methyl methacrylate, AN is acrylonitrile (monomer), CHP is cumene hydroperoxide (radical polymerization initiator), SP is a solubility parameter determined by the method described in the specification. Each is shown.
[0074]
[Table 2]

(Examples 1-6 and Comparative Examples 1-7)
Flame retardant of polycarbonate resin
Polycarbonate resin (PC: Teflon A-2200 manufactured by Idemitsu Petrochemical Co., Ltd., viscosity average molecular weight 22000), polyorganosiloxane-containing graft copolymer (SG-1 to SG-5) obtained in Reference Examples 3 to 7, PTFE (Polytetrafluoroethylene: Daikin Industries, Ltd. Polyflon FA-500) and antioxidant (AO-30: Asahi Denka Co., Ltd. Adeka Stub AO-30, HP-10: Asahi Denka Co., Ltd. Adeka Stub HP-10) The composition shown in Table 3 was used.
[0075]
The obtained blend was melt-kneaded at 280 ° C. with a twin screw extruder (TEX44SS manufactured by Nippon Steel Works) to produce pellets. A 1/8 inch Izod test piece and a 1/16 inch flame retardant evaluation test piece were prepared with a FAS100B injection molding machine manufactured by FANUC Corporation in which the obtained pellet was set to a cylinder temperature of 270 ° C. The obtained test piece was used for evaluation according to the evaluation method.
[0076]
The results are shown in Table 3.
[0077]
[Table 3]

From Table 3, flame retardant-impact resistance by blending polycarbonate resin, polyorganosiloxane-containing graft copolymer, fluororesin, and antioxidant so that the silicon content in the entire composition is a specific amount. It can be seen that a polycarbonate-based flame retardant resin composition having an excellent balance between moldability and moldability can be obtained.
[0078]
(Example 7 and Comparative Example 8)
Flame retardant of polycarbonate / polyethylene terephthalate mixed resin
PC, polyethylene terephthalate resin (PET: Belpet EFG-70 manufactured by Kanebo Co., Ltd.), polyorganosiloxane-containing graft copolymer (SG-3) obtained in Reference Example 5, PTFE and antioxidant (AO-30: Asahi Denka Co., Ltd. ADK STAB AO-30) was used and blended with the composition shown in Table 4.
[0079]
The obtained blend was melt-kneaded at 260 ° C. with a twin-screw extruder (TEX44SS manufactured by Nippon Steel) to produce pellets. A 1/8 inch Izod test piece and a 1/12 inch flame retardant evaluation test piece were prepared using a FAS100B injection molding machine manufactured by FANUC Corporation in which the obtained pellet was set to a cylinder temperature of 260 ° C. The obtained test piece was used for evaluation according to the evaluation method.
[0080]
The results are shown in Table 4.
[0081]
[Table 4]

From Table 4, flame retardant by blending polycarbonate / polyethylene terephthalate mixed resin, polyorganosiloxane-containing graft copolymer, fluororesin, and antioxidant so that the silicon content in the entire composition is a specific amount. It can be seen that a polycarbonate-based flame retardant resin composition having an excellent balance of property-impact resistance-moldability can be obtained.
[0082]
【The invention's effect】
According to the present invention, a non-halogen and non-phosphorus flame retardant can be used to obtain a polycarbonate flame retardant resin composition having an excellent balance of flame retardancy, impact resistance and molding processability.

Claims (7)

(A) 100 parts by weight of polycarbonate-based resin, (B) polyorganosiloxane-containing graft copolymer obtained by polymerizing vinyl monomer (b-2) in the presence of polyorganosiloxane particles (b-1) 1 to 4.5 parts by weight, (C) a fluororesin 0.05 to 1 part by weight and (D) an antioxidant 0 to 2 parts by weight, the total amount of the resin composition being 100% by weight A polycarbonate flame retardant resin composition having a silicon content of 0.3 to 1.5% by weight based on the weight of the resin. The polycarbonate flame retardant resin composition according to claim 1, wherein the polyorganosiloxane particles (b-1) have an average particle size of 0.008 to 0.6 µm. The polycarbonate flame-retardant resin composition according to claim 1 or 2, wherein the polyorganosiloxane particles have a coefficient of variation of 10 to 70%. The polyorganosiloxane-containing graft copolymer contains 60 to 10% by weight (total 100% by weight) of the vinyl monomer (b-2) in the presence of 40 to 90% by weight of the polyorganosiloxane particles (b-1). The polycarbonate flame-retardant resin composition according to claim 1 or 2, which is a graft copolymer obtained by polymerization. The polycarbonate flame retardant resin composition according to claim 1, 2 or 4, wherein the polyorganosiloxane particles (b-1) are in a latex form. 2. The polycarbonate flame retardant according to claim 1, wherein the vinyl monomer (b-2) has a solubility parameter of 9.15 to 10.15 (cal / cm ³ ) ^1/2 of the polymer of the vinyl monomer. Resin composition. The vinyl monomer (b-2) is selected from the group consisting of an aromatic vinyl monomer, a vinyl cyanide monomer, a (meth) acrylic acid ester monomer, and a carboxyl group-containing vinyl monomer. 6. The polycarbonate flame retardant resin composition according to claim 1, 2, 4 or 5, which is at least one selected monomer.