JP3976549B2 - Aromatic vinyl resin foam and method for producing the same - Google Patents

Description

（式中、Ｒ₁はレゾルシノール、ハイドロキノン、ビスフェノールＡ等の残基、Ｒ₂はフェニル基、トリル基、キシリル基などであり、同一でも異なっていてもよい、ｎは１以上の整数である）
【００６９】
一般式（５）で表されるリン酸エステル類としては、レゾルシノール・ビス（ジフェニルホスフェート）、レゾルシノール・ビス（ジキシレニルホスフェート）、レゾルシノール・ビス（ジクレジルホスフェート）、ハイドロキノン・ビス（ジフェニルホスフェート）、ハイドロキノン・ビス（ジキシレニルホスフェート）、ハイドロキノン・ビス（ジクレジルホスフェート）、ビスフェノールＡ・ビス（ジフェニルホスフェート）、ビスフェノールＡ・ビス（ジキシレニルホスフェート）、ビスフェノールＡ・ビス（ジクレジルホスフェート）などの芳香族系ジ（リン酸エステル）類（前記一般式１において、ｎ＝１のもの）、ポリ（レゾルシノール・フェニルホスフェート）、ポリ（レゾルシノール・クレジルホスフェート）、ポリ（レゾルシノール・キシレニルホスフェート）、ポリ（ハイドロキノン・フェニルホスフェート）、ポリ（ハイドロキノン・クレジルホスフェート）、ポリ（ハイドロキノン・キシレニルホスフェート）、ポリ（ビスフェノールＡ・フェニルホスフェート）、ポリ（ビスフェノールＡ・クレジルホスフェート）、ポリ（ビスフェノールＡ・キシレニルホスフェート）などの芳香族系ポリ（リン酸エステル）類（前記一般式１においてｎが２以上のもの）などのリン酸エステル類、ホスファゼン、ポリホスファゼンなどのホスファゼン類、リン酸アミン類、リン酸アミド類などが挙げられる。
【００７０】
該リン系化合物が粒子状、粉体状、板状、針状などの固体形状であった場合にはメラミン樹脂、フェノール樹脂、グアナミン樹脂、エポキシ樹脂、ウレタン樹脂、尿素樹脂、シリコーン樹脂、シランカップリング剤などから選ばれる１種以上の化合物など表面被覆あるいは表面処理できる化合物で表面処理されたものであってもよい。
【００７１】
該リン系化合物では、燃焼時の形状保持の観点から、アンモニウムホスフェート、アンモニウムポリホスフェート、メラミンホスフェート、メラミンポリホスフェートなどのリン酸塩、ホスファゼン、ポリホスファゼンなどのホスファゼン類などのリン原子および窒素原子を含有する化合物が好ましい。さらに、リン酸塩類では表面処理されたリン酸塩類がより好ましい。
【００７２】
本発明で用いられる窒素原子を含有する化合物とは、分子中に窒素原子を含有する化合物をいい、その具体例としては、炭素原子と窒素原子からなるトリアジン構造を有する化合物であり、具体的にはメラミン、メチロールメラミン類などのメラミン誘導体、シアヌル酸、メチルシアヌレート、ジエチルシアヌレート、トリメチルシアヌレート、トリエチルシアヌレート、イソシアヌル酸、メチルイソシアヌレート、Ｎ，Ｎ’−ジエチルイソシアヌレート、トリスメチルイソシアヌレート、トリスエチルイソシアヌレート、ビス（２−カルボキシエチル）イソシアヌレート、１，３，５−トリス（２−カルボキシエチル）イソシアヌレート、トリス（２，３−エポキシプロピル）イソシアヌレートなどのシアヌル酸、イソシアヌル酸またはその誘導体、メラミンシアヌレートなどのメラミン（誘導体）と（イソ）シアヌル酸（誘導体）との塩などが挙げられる。
【００７３】
さらには、ジアゾ化合物、テトラゾールグアニジン塩、テトラゾールピペラジン塩、テトラゾールアンモニウム塩等のテトラゾールアミン塩類、また、テトラゾールナトリウム塩、テトラゾールマンガン塩等のテトラゾール金属塩類などのテトラゾール化合物、例えば５，５’−ビステトラゾール２グアニジン塩、５，５’−ビステトラゾール２アンモニウム塩、５，５’−ビステトラゾール２アミノグアニジン塩、５，５’−ビステトラゾールピペラジン塩が挙げられる。
【００７４】
窒素原子含有化合物では、燃焼時の形状保持の観点から、トリアジン骨格含有化合物が好ましく、具体的にはメラミン、シアヌル酸、イソシアヌル酸、メラミンシアヌレートなどが好ましい。
【００７５】
本発明では、リン原子含有化合物または窒素原子含有化合物から選ばれる１種または２種以上の化合物が用いられるが、加熱時の形状保持性の向上の観点から、リン原子含有化合物と窒素原子含有化合物の両者ともを、それぞれ１種または２種以上併用して用いることが好ましい。
【００７６】
リン原子含有化合物または窒素原子含有化合物から選ばれる１種または２種以上の化合物の含有量は、芳香族ビニル系樹脂１００重量部に対して、１〜２００重量部であり、好ましくは５〜１５０重量部、さらに好ましくは１０〜１２０重量部である。該化合物が１重量部未満では自己消火性効果が見られず、２００重量部を越えると発泡体の成形性が困難となるため好ましくない。
【００７７】
さらに本発明では、燃焼時および加熱時の形状保持性の効果をより一層高める目的で、多価アルコール類が併用して用いられる。多価アルコール類は、１分子中に２個以上の水酸基を含有する化合物であって、その具体例としては、モノペンタエリスリトール、ジペンタエリスリトール、トリペンタエリスリトールなどのペンタエリスリトール類、エチレングリコール、ジエチレングリコール、プロピレングリコール、ポリエチレングリコール、ポリプロピレングリコール、エチレングリコールとプロピレングリコールとの共重合体などのグリコール類、グリセリン、レゾルシノール、トリメチロールプロパンなどが挙げられる。多価アルコール類では、燃焼時の形状保持の観点から、モノペンタエリスリトールが好ましい。
【００７８】
多価アルコール類の含有量は、芳香族ビニル系樹脂１００重量部に対して、１〜２００重量部であり、好ましくは５〜１５０重量部、さらに好ましくは１０〜１２０重量部である。含有量が１重量部未満では自己消火性効果が見られず、２００重量部を越えると発泡体の成形性が困難となるため好ましくない。
【００７９】
本発明では、リン原子含有化合物と多価アルコール類のいずれもを、それぞれ１種又は２種以上併用して用いること、窒素原子含有化合物と多価アルコール類のいずれもを、それぞれ１種又は２種以上併用して用いること、リン原子含有化合物、窒素原子含有化合物および多価アルコール類のいずれもを、それぞれ１種又は２種以上併用して用いることができるが、リン原子含有化合物、窒素原子含有化合物および多価アルコール類のいずれもを、それぞれ１種又は２種以上併用して用いることがより好ましい。
【００８０】
本発明において用いられる発泡剤に特に制限はないが、例えば、プロパン、ｎ−ブタン、ｉ−ブタン、ｎ−ペンタン、ｉ−ペンタン、ネオペンタンなどに例示される飽和炭化水素、ジメチルエーテル、ジエチルエーテル、メチルエチルエーテル、イソプロピルエーテル、ｎ−ブチルエーテル、ジイソプロピルエーテル、フラン、フルフラール、２−メチルフラン、テトラヒドロフラン、テトラヒドロピランなどに例示されるエーテル類、ジメチルケトン、メチルエチルケトン、ジエチルケトン、メチルｎ−プロピルケトン、メチルｎ−ブチルケトン、メチルｉ−ブチルケトン、メチルｎ−アミルケトン、メチルｎ−ヘキシルケトン、エチルｎ−プロピルケトン、エチルｎ−ブチルケトンに例示されるケトン類、メタノール、エタノール、プロピルアルコール、ｉ−プロピルアルコール、ブチルアルコール、ｉ−ブチルアルコール、ｔ−ブチルアルコールに例示されるアルコール類、蟻酸メチルエステル、蟻酸エチルエステル、蟻酸プロピルエステル、蟻酸ブチルエステル、蟻酸アミルエステル、プロピオン酸メチルエステル、プロピオン酸エチルエステルに例示されるカルボン酸エステル類、アゾジカルボンアミド、アゾビスイソブチロニトリル、Ｎ，Ｎ’−ジニトロソペンタメチレンテトラミン、ｐ−トルエンスルホニルヒドラジン、ｐ，ｐ’−オキシビス（ベンゼンスルホヒドラジド）、塩化メチル、塩化エチルなどに例示される有機発泡剤、トリクロロフルオロメタン（Ｒ１１）、ジクロロジフルオロメタン（Ｒ１２）、クロロジフルオロメタン（Ｒ２２）、テトラクロロジフルオロエタン（Ｒ１１２）、ジクロロフルオロエタン（Ｒ１４１ｂ）、クロロジフルオロエタン（Ｒ１４２ｂ）、ジフルオロエタン（Ｒ１５２ａ）、ＨＦＣ−２４５ｆａ、ＨＦＣ−２３６ｅａ、ＨＦＣ−２４５ｃａ、ＨＣＦＣ−２２５ｃａなどに例示されるフロン系発泡剤、水、二酸化炭素、窒素、空気などに例示される無機発泡剤などが挙げられる。これらは単独又は２種以上混合して使用することができる。
【００８１】
これらの中でも、次に記す非ハロゲン系発泡剤を使用することにより、本発明の発泡体の環境適合性を更に向上させることができるため望ましい。すなわち、プロパン、ｎ−ブタン、ｉ−ブタン、ｎ−ペンタン、ｉ−ペンタン、ネオペンタンなどに例示される飽和炭化水素、ジメチルエーテル、ジエチルエーテル、メチルエチルエーテル、イソプロピルエーテル、ｎ−ブチルエーテル、ジイソプロピルエーテル、フラン、フルフラール、２−メチルフラン、テトラヒドロフラン、テトラヒドロピランなどに例示されるエーテル類、 Ｎ，Ｎ’−ジニトロソペンタメチレンテトラミン、Ｎ，Ｎ’−ジメチルＮ，Ｎ’−ジニトロソテレフタールアミド、アゾジカルボンアミド、ベンゼンスルホニルヒドラジドアゾジカルボンアミド、 ｐ−トルエンスルホニルヒドラジン、アゾビスホルムアミド、ジエチルアゾジカルボキシレート、アゾビスイソブチロニトリル 、ｐ−トルエンスルホニルヒドラジン、ｐ，ｐ’−オキシビス（ベンゼンスルホヒドラジド）、３，３’−ジスルホヒドラジドジフェニルスルフォンなどの有機化学発泡剤、水、二酸化炭素、窒素、空気、炭酸ナトリウム、炭酸カリウム、炭酸マグネシウム、炭酸カルシウム、炭酸バリウム、炭酸アルミニウム、炭酸亜鉛、炭酸アンモニウム、炭酸水素ナトリウム、炭酸水素カリウム、その他の炭酸塩、その他の炭酸水素塩、などに例示される無機発泡剤などの非ハロゲン系発泡剤が環境適合性の観点で好ましい。
【００８２】
本発明の芳香族ビニル系樹脂発泡体の製造のために、添加される発泡剤の量としては、発泡倍率の設定値などに応じて適宜変えればよい。通常、発泡倍率２０〜４０倍程度であれば発泡剤の合計量を該芳香族ビニル系樹脂１００重量部に対して２〜２０重量部とするのが好ましい。発泡倍率が極小さくて良い場合は、発泡剤の添加量が２重量部未満でも充分である。逆に発泡倍率が１００倍といった大きな場合は、２０重量部を越えて添加する場合もあるが、この場合、過剰な発泡剤量のため発泡体中にボイドなどの不良を生じることに注意しなければならない。
【００８３】
また本発明においては、必要に応じて本発明の効果を阻害しない範囲でシリカ、タルク、ケイ酸カルシウム、ワラストナイト、カオリン、クレイ、マイカ、酸化亜鉛、酸化チタン、炭酸カルシウムなどの無機化合物、ステアリン酸ナトリウム、ステアリン酸マグネシウム、ステアリン酸バリウム、流動パラフィン、オレフィン系ワックス、ステアリルアミド系化合物などの加工助剤、フェノール系抗酸化剤、リン系安定剤、ベンゾトリアゾール類、ヒンダードアミン類などの耐光性安定剤、帯電防止剤、顔料などの着色剤などの添加剤を含有させることができる。
【００８４】
さらに本発明においては、更に優れた難燃性を付与する目的で、上記以外のリン系難燃剤、窒素系難燃剤、ケイ素系難燃剤、金属水酸化物、イオウ系難燃剤、アンチモン化合物、ホウ素化合物など種々の難燃剤を用いることができる。
【００８５】
本発明は、基本的には、非ハロゲン系難燃剤を用いて環境適合性を高めることを本来の目的とするので、リン原子含有化合物および／または窒素原子含有化合物等の非ハロゲン系難燃剤を多く使用した場合には、ハロゲン系難燃剤を必要としないが、より高度な難燃性を要求するときには、既述の非ハロゲン系難燃剤に加えて次の如きハロゲン系難燃剤を補助的に追加使用することができる。
【００８６】
例えば、ハロゲン系難燃剤としては、ヘキサブロモシクロドデカンなどの脂肪族あるいは脂環族炭化水素の臭素化物、ヘキサブロモベンゼン、エチレンビスペンタブロモジフェニル、デカブロモジフェニルエーテル、オクタブロモジフェニルエーテル、２，３−ジブロモプロピルペンタブロモフェニルエーテルなどの芳香族化合物の臭素化物、テトラブロモビスフェノールＡ、テトラブロモビスフェノールＡビス（２，３−ジブロモプロピルエーテル）、テトラブロモビスフェノールＡ（２−ブロモエチルエーテル）、テトラブロモビスフェノールＡジグリシジルエーテル、テトラブロモビスフェノールＡジグリシジルエーテルとトリブロモフェノール付加物などの臭素化ビスフェノール類およびその誘導体、テトラブロモビスフェノールＡポリカーボネートオリゴマー、テトラブロモビスフェノールＡジグリシジルエーテルとブロモ化ビスフェノール付加物エポキシオリゴマーなどの臭素化ビスフェノール類誘導体オリゴマー、テトラブロモフタレーロジオール、テトラブロモフタレートエステル、テトラブロモフタレートジソジウム、ポリ（ペンタブロモベンジルポリアクリレート）、ペンタブロモフェノール、ブロモフェノキシエタノール、臭素化フェノール（ノボラック型）、ジブロモクレジルグリシジルエーテル、臭素化芳香族トリアジン、ビニルブロマイド、トリブロモフェノール、ジブロモフェノール、ジブロモメタクレゾール、ジブロモネオペンチルグリコール、エチレンビステトラブロモフタルイミド、エチレンビスジブロモノルボルナンジカルボキシイミド、ビス（２，４，６ートリブロモフェノキシ）エタン、臭素化アクリル系樹脂などの臭素系芳香族化合物、塩素化パラフィン、塩素化ナフタレン、パークロロペンタデカン、テトラクロロ無水フタル酸、塩素化芳香族化合物、塩素化脂環状化合物、などが挙げられる。
【００８７】
本発明の芳香族ビニル系樹脂発泡体の製造方法としては、例えば、芳香族ビニル系樹脂、膨潤性層状珪酸塩、発泡剤およびリン原子含有化合物、窒素原子含有化合物、多価アルコール類、必要によりその他の化合物などの添加剤を押出機等の混練機を用いて溶融混練した後、押出発泡成形する方法、同様に溶融混練して発泡性組成物を得た後、必要に応じてビーズ状、板状、シート状など形態を付与し、再び加熱して発泡させ発泡体を得る方法、芳香族ビニル系樹脂、膨潤性層状珪酸塩、および添加剤を押出機等の混練機を用いて溶融混練し、途中から発泡剤を注入して押出発泡成形する方法、芳香族ビニル系樹脂、膨潤性層状珪酸塩、および添加剤を押出機等の混練機を用いて溶融混練し樹脂組成物を得た後、再び溶融混練し、途中から発泡剤を注入して押出発泡成形する方法、同様に溶融混練して樹脂組成物を得た後、必要に応じてビーズ状、板状、シート状など形態を付与し、次いで発泡剤を含浸させた後、再び加熱して発泡させて発泡体を得る方法等が挙げられる。
【００８８】
更に、芳香族ビニル系化合物および必要に応じて他の化合物を重合させて芳香族ビニル系樹脂を製造する際に、膨潤性層状珪酸塩、発泡剤および添加剤を添加し、発泡性組成物とした後、必要に応じてビーズ状、板状、シート状など形態を付与し、再び加熱して発泡させ発泡体を得る方法、同様に芳香族ビニル系樹脂を製造する際に、膨潤性層状珪酸塩、および添加剤を添加し、樹脂組成物とした後、必要に応じてビーズ状、板状、シート状など形態を付与し、次いで発泡剤を含浸させた後、再び加熱して発泡させ発泡体を得る方法などが挙げられる。これらのうち押出発泡成形が最も好ましい実施態様として推奨される。
【００８９】
膨潤性層状珪酸塩の分散性の点から、芳香族ビニル系樹脂、膨潤性層状珪酸塩、および必要により発泡剤、添加剤を押出機等の混練機を用いて溶融混練し（発泡性）樹脂組成物を得、次いで発泡させる方法、および、芳香族ビニル系化合物および必要に応じて他の化合物を重合させて芳香族ビニル系樹脂を製造する際に、膨潤性層状珪酸塩、および必要により発泡剤、添加剤を添加し、（発泡性）樹脂組成物を得、次いで発泡させる方法が好ましい。
【００９０】
押出機等の混練機を用いて溶融混練する場合、膨潤性層状珪酸塩を添加する方法としては、予め芳香族ビニル系樹脂とドライブレンドしておく方法、膨潤性層状珪酸塩を混練の途中から添加する方法、予め膨潤性層状珪酸塩を水、有機化合物などの分散媒中に分散させ、次いで芳香族ビニル系樹脂とブレンドする方法、予め膨潤性層状珪酸塩を水、有機化合物などの分散媒中に分散させ、混練の途中から添加する方法などが挙げられる。予め膨潤性層状珪酸塩を水、有機化合物などの分散媒中に分散させる場合には、混練の途中、最後あるいは混練後に水、有機化合物などの分散媒を除去することが好ましいが、水、有機化合物などの分散媒を発泡剤としても用いる場合はこの限りではない。さらに、芳香族ビニル系樹脂と膨潤性層状珪酸塩を予め溶融混練する方法として、例えば、特開平９−２１７０１２号公報などでも提案されている。
【００９１】
芳香族ビニル系樹脂を製造する際に膨潤性層状珪酸塩を添加する方法としては、予め芳香族ビニル系化合物、および／または、必要に応じて他の化合物中に分散させる方法、予め膨潤性層状珪酸塩を水、有機化合物などの分散媒中に分散させ重合の前、始め、途中、重合後の任意の段階に添加する方法、膨潤性層状珪酸塩を直接重合の前、始め、途中、重合後の任意の段階に添加する方法などが挙げられる。さらに、芳香族ビニル系樹脂を製造する際に膨潤性層状珪酸塩を添加する方法としては、特開昭６３−２１５７７５号公報などでも提案されている。
【００９２】
【実施例】
次に本発明の芳香族ビニル系樹脂発泡体およびその製造方法を実施例に基づいて、さらに詳細に説明するが、本発明はかかる実施例のみに限定されるものではない。
【００９３】
以下に示す実施例、比較例の方法で得られた発泡体の特性として、発泡体密度、自己消火性、燃焼時の溶融変形・溶融滴下状況、高温加熱時の形状変化状況を下記の方法に従って調べた。
って評価した。
１）発泡体密度（kg/m³）：発泡体密度は、次の式：発泡体密度（g/cm³）＝発泡体重量（g）／発泡体体積（cm³）に基づいて求め、単位を（kg/m³）に換算して示した。
２）自己消火性：製造後１４日経過した発泡体を用い、ＪＩＳ Ａ９５１１に規定の燃焼性評価における測定方法Ａに準じて燃焼性試験を行い、下記の基準に従い判定した。
○：炎を離した後、すぐ消炎あるいは若干燃焼したが自己消火した。
△：炎を離した後、ある程度は燃焼したが自己消火し、試験片は残存した。
×：炎を離した後、自己消火せず試験片全体が燃焼してしまった。
【００９４】
３）燃焼時の溶融変形、溶融滴下状況（形状保持性）：２）と同様にして燃焼性試験を行い、消炎後の状態を目視にて観察し下記の基準に従い判定した。
○：溶融滴下せず、炭化あるいは発泡炭状になり、形状をほぼ維持あるいは変形するものの収縮は見られない。
△：溶融滴下せず、炭化あるいは発泡炭状になるが、収縮が見られた。
×：溶融滴下して試験片が残存しなかった。
【００９５】
４）高温加熱時の形状変化状況（形状保持特性）：得られた発泡体から５０×５０×１０ｍｍの試験片を切り出し、５００℃に保った電気炉内で５分間加熱した後の状態を目視にて観察し下記の基準に従い判定した。
◎：残存物は若干収縮あるいは膨張したが、ほぼ元の形状を維持していた。
○：残存物は収縮あるいは膨張するが、ほぼ元の形状の相似形に近い形で残存していた。
△：残存物は大きく収縮あるいは膨張するもののある程度形状を維持した。
×：溶融してしまい形状が崩れてしまうあるいは残存物が無かった。
ただし、例えば△〜○と評価した場合は、△と○の中間の判定であったことを示している。
【００９６】
５）膨潤性層状珪酸塩の底面間隔（ｎｍ）：Ｘ線発生装置（理学電機（株）製、ＲＵ−２００Ｂ）を用い、ターゲットＣｕＫα線、Ｎｉフィルター、電圧４０ｋＶ、電流２００ｍＡ、走査角２θ＝０.２〜１６.０°、ステップ角＝０.０２°の測定条件で小角Ｘ線回折ピーク角値を測定し、底面間隔を、小角Ｘ線回折ピーク角値をＢｒａｇｇの式に代入して算出した。ただし、小角Ｘ線ピーク角値の確認が困難である場合は、膨潤性層状珪酸塩が膨潤し、ピーク角値が確認困難なまで分散したか、あるいは十分に膨潤し、実質的に分子状に分散したこととなる。
【００９７】
６）膨潤性層状珪酸塩の分散状態および粒子厚み（ｎｍ）：厚み５０〜１００μｍの超薄切片を用いた。透過型電子顕微鏡（日本電子ＪＥＭ−１２００ＥＸ）を用い、加速電圧８０ｋＶで倍率４万〜１００万倍で膨潤性層状珪酸塩の分散状態を観察撮影した。ＴＥＭ写真において、１００個以上の分散粒子が存在する領域を選択し、粒子数、粒子厚みを、目盛り付きの定規を用いた計測した。得られた結果を、下記式に当てはめ、粒子厚みが１００ｎｍ以下の粒子割合を求めた。
粒子厚みが１００ｎｍ以下の粒子割合＝（膨潤性層状珪酸塩の粒子厚みが１００ｎｍ以下の粒子の数／膨潤性層状珪酸塩の粒子の総数）×１００
【００９８】
下記に示した原材料を用いて実施例・比較例の方法で評価した。
芳香族ビニル系樹脂
・樹脂１：ポリスチレンホモポリマー：新日鐵化学（株）製エスチレンＧ−１７（メルトインデックス＝３．１）
・樹脂２：スチレン−メタクリル酸共重合体：エー・アンド・エム スチレン（株）製スタイロンＧ９００１（メタクリル酸共重合割合は８ｗｔ％）
・樹脂３：スチレン−無水マレイン酸共重合体：ＡＲＣＯ Ｃｈｅｍｉｃａｌ Ｊａｐａｎ製ダイラークＤ２３２
・樹脂４：スチレン−アクリロニトリル共重合体：東洋スチレン（株）製トーヨーＡＳ ＡＳ−６１ＮＴ
【００９９】
膨潤性層状珪酸塩
・珪酸塩１：モンモリロナイト：クニミネ工業（株）製クニピアＦ：底面間隔＝１．２ｎｍ
・珪酸塩２：膨潤性フッ素雲母：コープケミカル（株）製ソマシフＭＥ−１００：底面間隔＝１．０ｎｍ
・珪酸塩３：有機化処理モンモリロナイト：サザンクレープロダクツ製Ｃｌｏｉｓｉｔｅ２０Ａ（ジアルキル（Ｃ１４〜１８）メチルアンモニウムイオンで処理したモンモリロナイト：処理量は約３８重量％）：底面間隔＝２．４ｎｍ
・珪酸塩４：有機化処理膨潤性フッ素雲母：コープケミカル（株）製ＭＡＥ−１２０（ジアルキル（Ｃ１４〜１８）メチルアンモニウムイオンで処理した膨潤性フッ素雲母：処理量は約３８重量％）：底面間隔＝３．１ｎｍ
・珪酸塩５：有機化処理モンモリロナイト：製造例１で製造した
・珪酸塩６：有機化処理膨潤性フッ素雲母：製造例２で製造した
【０１００】
リン原子含有化合物
・ＴＰＰ：トリフェニルホスフェート：大八化学工業（株）製ＴＰＰ
・ＡＰＰ：ポリリン酸アンモニウム：チッソ（株）製テラージュＣ６０
窒素原子含有化合物
・ＭＣ：メラミンシアヌレート：日産化学工業（株）製ＭＣ−４４０
・メラミン：メラミン：和光純薬工業（株）製試薬
多価アルコール類
・ＰＥＲ：モノペンタエリスリトール：三菱瓦斯化学（株）製ペンタエリスリトール
【０１０１】
難燃剤
・ＨＢＣＤ：ヘキサブロムシクロドデカン：ＡＬＢＥＭＡＲＬＥ ＣＯＲＰＯＲＡＴＩＯＮ製
発泡剤
・イソブタン：三井化学（株）製
・ジメチルエーテル：三井化学（株）製
・ＨＣＦＣ１４２ｂ：１−クロロ１，１−ジフルオロエタン：ダイキン工業（株）製
【０１０２】
製造例１
イオン交換水３５００ｇにモンモリロナイト１２５ｇを加え、湿式ミル（日本精機（株）製）を用いて５０００ｒｐｍにて５分間撹拌し混合した。次いでフェニルトリメトキシシラン（信越シリコーン（株）製ＬＳ２７５０）３５ｇを加え、さらに１時間撹拌して処理した。得られたシラン系化合物処理モンモリロナイト分散液を１２０℃で２４時間乾燥して水を除去し、次いで粉砕して有機化処理モンモリロナイト粒子を得た。得られた有機化処理モンモリロナイトの底面間隔は２．４ｎｍであった。また、有機化処理モンモリロナイトを６５０℃にて２時間加熱した後の重量の加熱前の重量に対する割合は、８０重量％であり、モンモリロナイトが８０重量％含有されていることが確認された。
【０１０３】
製造例２
イオン交換水３５００ｇに膨潤性フッ素雲母１２５ｇを加え、湿式ミル（日本精機（株）製）を用いて５０００ｒｐｍにて５分間撹拌し混合した。次いでビスフェノールＡ共重合ポリエチレングリコール（三洋化成（株）製ＢＰＥ−１８０）１３ｇを加え、さらに１時間撹拌して処理した。得られたシラン系化合物処理モンモリロナイト分散液を１２０℃で２４時間乾燥して水を除去し、次いで粉砕して有機化処理処理膨潤性フッ素雲母粒子を得た。得られた有機化処理膨潤性フッ素雲母の底面間隔は１．９ｎｍであった。また、有機化処理膨潤性フッ素雲母を６５０℃にて２時間加熱した後の重量の加熱前の重量に対する割合は、９０重量％であり、膨潤性フッ素雲母が９０重量％含有されていることが確認された。
【０１０４】
（実施例１）
芳香族ビニル系樹脂として、樹脂１（ポリスチレンホモポリマー）１００重量部に対して、珪酸塩１（モンモリロナイト）３０重量部、ＡＰＰ（ポリリン酸アンモニウム）５０重量部、タルク０．３重量部、ステアリン酸バリウム０．２重量部をドライブレンドした後、３０ｍｍφ同方向回転ニ軸押出機（Ｌ／Ｄ＝３０）を用いて溶融混練し樹脂組成物を得た。
【０１０５】
得られた樹脂組成物を口径６５ｍｍと口径９０ｍｍのものを縦に連結した押出機へ約４０ｋｇ／ｈｒの割合で供給した。前記口径６５ｍｍの押出機に供給し、２００℃に加熱して溶融混練し、これに連結された口径９０ｍｍの押出機で樹脂温度を１２０℃に冷却し、口径９０ｍｍの押出機の先端に設けた厚さ方向２ｍｍ、幅方向５０ｍｍの長方形断面吐出口のあるダイスより大気中へ押し出し、直方体状の押出発泡体を得た。このとき発泡剤として、イソブタンを該樹脂１、１００重量部に対して４部、ジメチルエーテルを２部からなる発泡剤を、それぞれ別のラインから、前記口径６５ｍｍの押出機の先端付近（口径９０ｍｍの押出機の先端ダイスと反対側の端部側に接続される側の端部）から前記樹脂中に圧入した。得られた発泡体の特性を表１に示す。
【０１０６】
（実施例２〜１７）
前記に示す芳香族ビニル系樹脂、膨潤性層状珪酸塩、リン原子含有化合物、窒素原子含有化合物、多価アルコール類、および、発泡剤を用い、表１に示した組成にて、実施例１と同様にして樹脂組成物および発泡体を得た。得られた発泡体の特性を表１に示す。
（比較例１および２）
表１に示した組成にて、実施例１と同様にして樹脂組成物および発泡体を得た。得られた発泡体の特性を表１に示す。
【０１０７】
実施例１〜１７と比較例１および２を比較して判るように、本発明の膨潤性層状珪酸塩を含有した芳香族ビニル系樹脂発泡体は高温で加熱した際の形状保持性にも優れていることが判る。
【０１０８】
実施例１および３と実施例２、４、５、７および９を比較して判るように、リン原子含有化合物、窒素原子含有化合物、多価アルコール類を組み合わせることにより、自己消火性、燃焼時の形状保持性、加熱時の形状保持性を向上させることができ、特に３種共を併用することで、その合計重量部が比較的少量にて効果が発現されることが判る。
【０１０９】
実施例６、７および９と実施例１３〜１６を比較して判るように、極性基を有する芳香族ビニル系樹脂を用いた方が、ポリスチレンホモポリマーに比べ、加熱時の形状保持性が向上することが判る。実施例６および１３における膨潤性層状珪酸塩の分散状態を観察した結果、実施例６では粒子厚みが１００ｎｍ以下の粒子割合は１であったのに対し、実施例１３では１５と実施例６より高い値であった。
【０１１０】
実施例７と実施例１７を比較して判るように、リン原子含有化合物として、リン原子と窒素原子を含有するポリリン酸アンモニウムを用いた方が、加熱時の形状保持性に優れることが判る。
（実施例２１〜２９）
前記に示す芳香族ビニル系樹脂、膨潤性層状珪酸塩、リン原子含有化合物、窒素原子含有化合物、多価アルコール類、および、発泡剤を用い、表１に示した組成にて、実施例１と同様にして樹脂組成物および発泡体を得た。得られた発泡体の特性を表２に示す。
【０１１１】
実施例６、７および９と実施例１８〜２０を比較して判るように、有機化処理した膨潤性層状珪酸塩を用いた方が、処理していない膨潤性層状珪酸塩を用いた場合に比べ加熱時の形状保持性が向上することが判る。ただし、実施例１８では、モンモリロナイトの実質含有量は芳香族ビニル系樹脂１００重量部に対して５重量部、実施例１９では膨潤性フッ素雲母の実質含有量は芳香族ビニル系樹脂１００重量部に対して１０重量部、実施例２０では３０重量部である。さらに、実施例６、７、９におけるモンモリロナイトあるいは膨潤性フッ素雲母の底面間隔はそれぞれ、１．２ｎｍ、１．２ｎｍ、１．０ｎｍであったのに対して、実施例１８、１９、２０ではそれぞれ、２．３ｎｍ、３．０ｎｍ、３．０ｎｍであった。また、実施例６、７、９における粒子厚みが１００ｎｍ以下の粒子割合はいずれも１であったのに対して、実施例１８、１９、２０ではそれぞれ、３１、２５、２７であった。
【０１１２】
実施例１８および１９と実施例２１および２２と比較して判るように、極性基を有する芳香族ビニル系樹脂と有機化処理した膨潤性層状珪酸塩を組合せた方が、加熱時の形状保持性が向上することが判る。実施例２１、２２では、モンモリロナイト、膨潤性フッ素雲母の底面間隔を測定した結果、ごくわずかにそれぞれ２．４ｎｍ、３．１ｎｍの底面間隔を示すＸ線回折ピーク角値が観察された。分散状態を観察した結果、粒子厚みが１００ｎｍ以下の粒子割合はそれぞれ、８１、９０であった。さらには粒子厚みが１００ｎｍ以下の粒子の多くは、モンモリロナイト、膨潤性フッ素雲母の単位層厚みあるいは約２〜２０層積み重なった場合に相当する厚みであった。
【０１１３】
実施例２３〜２５、２７〜２９でも、実施例２１、２２と同様の膨潤性層状珪酸塩の分散状態であり、ごくわずかにそれぞれ珪酸塩３を用いた場合では２．４ｎｍ、珪酸塩４では３．１ｎｍ、珪酸塩５では２．４ｎｍの底面間隔を示すＸ線回折ピーク角値が観察され、粒子厚みが１００ｎｍ以下の粒子割合は、いずれも７５以上であった。また、実施例２６では、底面間隔が１．９ｎｍを示すＸ線回折ピーク角値が観察され、粒子厚みが１００ｎｍ以下の粒子割合は３２であった。
【０１１４】
（実施例３０）
芳香族ビニル系樹脂として、樹脂１（ポリスチレンホモポリマー）を用い、ニーダーに樹脂１（ポリスチレンホモポリマー）１００重量部を仕込み、水１００重量％に珪酸塩１（モンモリロナイト）を１０重量％を分散させた溶液を徐々に添加しながら混練し、最終的に該溶液を５０重量部添加した。得られた樹脂組成物を粉砕した後、３０ｍｍφ同方向回転ニ軸押出機（Ｌ／Ｄ＝３０）を用いて溶融混練した。次いで、得られた樹脂組成物を乾燥した後、樹脂１を１００重量部に対して、ＡＰＰ（ポリリン酸アンモニウム）２５重量部、ＭＣ（メラミンシアヌレート）１０重量部、ＰＥＲ（モノぺエンタエリスリトール）２５重量部、タルク０．３重量部、ステアリン酸バリウム０．２重量部になるようにドライブレンドした後、再び３０ｍｍφ同方向回転ニ軸押出機（Ｌ／Ｄ＝３０）を用いて溶融混練し樹脂組成物を得た。
【０１１５】
得られた樹脂組成物を口径６５ｍｍと口径９０ｍｍのものを縦に連結した押出機へ約４０ｋｇ／ｈｒの割合で供給した。前記口径６５ｍｍの押出機に供給し、２００℃に加熱して溶融混練し、これに連結された口径９０ｍｍの押出機で樹脂温度を１２０℃に冷却し、口径９０ｍｍの押出機の先端に設けた厚さ方向２ｍｍ、幅方向５０ｍｍの長方形断面吐出口のあるダイスより大気中へ押し出し、直方体状の押出発泡体を得た。このとき発泡剤として、イソブタンを該樹脂１１００重量部に対して４部、ジメチルエーテルを２部からなる発泡剤を、それぞれ別のラインから、前記口径６５ｍｍの押出機の先端付近（口径９０ｍｍの押出機の先端ダイスと反対側の端部側に接続される側の端部）から前記樹脂中に圧入した。得られた発泡体の特性を表２に示す。
【０１１６】
底面間隔を測定した結果、１．２ｎｍを示すＸ線回折ピーク角値が観察され、粒子厚みが１００ｎｍ以下の粒子割合は５０であった。
【０１１７】
実施例６と比較して、加熱時の形状保持性が向上していることが判る。
（実施例３１）
芳香族ビニル系樹脂として、樹脂１（ポリスチレンホモポリマー）１００重量部に対して珪酸塩４（有機化処理した膨潤性フッ素雲母）１６重量部をドライブレンドした後、３０ｍｍφ同方向回転ニ軸押出機（Ｌ／Ｄ＝３０）を用いて溶融混練した。得られた樹脂組成物を乾燥した後、再び、３０ｍｍφ同方向回転ニ軸押出機（Ｌ／Ｄ＝３０）を用いて溶融混練し、これをもう二度繰り返した。次いで、樹脂１を１００重量部に対して、ＡＰＰ（ポリリン酸アンモニウム）２５重量部、ＭＣ（メラミンシアヌレート）１０重量部、ＰＥＲ（モノぺエンタエリスリトール）２５重量部、タルク０．３重量部、ステアリン酸バリウム０．２重量部になるようにドライブレンドした後、再び３０ｍｍφ同方向回転ニ軸押出機（Ｌ／Ｄ＝３０）を用いて溶融混練し樹脂組成物を得た。
【０１１８】
得られた樹脂組成物を口径６５ｍｍと口径９０ｍｍのものを縦に連結した押出機へ約４０ｋｇ／ｈｒの割合で供給した。前記口径６５ｍｍの押出機に供給し、２００℃に加熱して溶融混練し、これに連結された口径９０ｍｍの押出機で樹脂温度を１２０℃に冷却し、口径９０ｍｍの押出機の先端に設けた厚さ方向２ｍｍ、幅方向５０ｍｍの長方形断面吐出口のあるダイスより大気中へ押し出し、直方体状の押出発泡体を得た。このとき発泡剤として、イソブタンを該樹脂１１００重量部に対して４部、ジメチルエーテルを２部からなる発泡剤を、それぞれ別のラインから、前記口径６５ｍｍの押出機の先端付近（口径９０ｍｍの押出機の先端ダイスと反対側の端部側に接続される側の端部）から前記樹脂中に圧入した。得られた発泡体の特性を表２に示す。
【０１１９】
底面間隔を測定した結果、３．０ｎｍを示すＸ線回折ピーク角値が観察され、粒子厚みが１００ｎｍ以下の粒子割合は４０であった。
【０１２０】
実施例１９と比較して、加熱時の形状保持性が向上していることが判る。
（実施例３２）
樹脂１を樹脂２（スチレン−メタクリル酸共重合体）にした以外は実施例３１と同様にして芳香族ビニル系樹脂発泡体を得た。
【０１２１】
底面間隔を測定した結果、Ｘ線回折ピーク角値が観察されなかった。また、粒子厚みが１００ｎｍ以下の粒子割合は１００であり、膨潤性フッ素雲母がほぼ分子状に分散していることが観察された。
【０１２２】
実施例２２と比較して、加熱時の形状保持性が向上していることが判る。
【０１２３】
【表１】

【０１２４】
【表２】

【０１２５】
【発明の効果】
本発明によれば、環境適合性に優れた熱可塑性樹脂である芳香族ビニル系樹脂からなる発泡体及びその製造方法であって、炎と接した際の溶融滴下、および高温に曝されたときの変形などが飛躍的に改善され、難燃性に優れた芳香族ビニル系樹脂発泡体が得られる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a foam made of an aromatic vinyl resin that is a thermoplastic resin excellent in environmental compatibility and a method for producing the same. More specifically, the present invention relates to an aromatic vinyl resin foam excellent in flame retardancy and a method for producing the same, which drastically improves melt dripping when in contact with a flame and deformation when exposed to a high temperature.
[0002]
[Prior art]
Synthetic resin foams have excellent heat insulation properties and are therefore used as heat insulating materials for houses as building materials. Examples of such a synthetic resin foam include aromatic vinyl resin foams such as styrene resin foams.
[0003]
It is already known that foams can be obtained by foaming methods such as extrusion foam molding and bead method foaming by incorporating a foaming agent such as halogenated hydrocarbons, hydrocarbons, carbon dioxide into an aromatic vinyl resin. ing.
[0004]
When such an aromatic vinyl-based resin foam is used as a heat insulating material for construction, flame retardance such as self-extinguishing properties is required, and for example, the flammability level is defined in JIS A9511. Such aromatic vinyl resin foams that require flame retardancy generally contain a halogen flame retardant. However, although the aromatic vinyl-based resin foam obtained in this way is self-extinguishing, it disappears or melts and drops when it comes into contact with a flame during a combustion test, and the form is not maintained. Therefore, the expansion | deployment to the use for which a shape is requested | required at the time of combustion is restrict | limited.
[0005]
Examples of the resin foam that retains its shape to some extent when in contact with flame include thermosetting resin foams such as phenol-formaldehyde resin foams. However, in such a foam, melting and dripping does not occur and the form is maintained, but the foam is brittle, the living space is contaminated by residual formaldehyde, and further, it is a thermosetting resin, so it should be recycled. There is a problem with environmental compatibility, such as being very difficult.
[0006]
As a thermoplastic resin extruded foam excellent in environmental compatibility, for example, in Japanese Patent Application Laid-Open No. 2001-200087, a thermoplastic resin extruded foam in which bentonite is contained in a thermoplastic resin and water is used as a foaming agent is proposed. However, in the present invention, it is not particularly aimed at combustion resistance, and moreover, it is not aimed at melting dripping during combustion or prevention of deformation at high temperatures. Furthermore, even if a flame retardant is added, it does not take into account the use of a non-halogen flame retardant.
JP-A-10-60160 discloses a flame retardant resin obtained by melt-kneading 100 parts by weight of a thermoplastic resin, 0.5 to 50 parts by weight of a phosphorus flame retardant, and 0.01 to 20 parts by weight of a layered silicate. There has been proposed a flame retardant thermoplastic resin composition which is a composition and suppresses the melt dripping property during combustion without using a halogen flame retardant. However, the invention is intended for injection molding and does not take into consideration the flame retardancy unique to foams, does not suggest any foams, and the foams are exposed to high temperatures. There is no mention of shape retention in the case.
[0007]
In view of such a problem, in Japanese Patent Application No. 2000-337980, we have 1) 1 to 200 parts by weight of a phosphorus compound and 2) a compound containing a triazine skeleton and / or many for 100 parts by weight of a styrene resin. A styrenic resin foam characterized by containing 1 to 200 parts by weight of a monohydric alcohol was proposed. In the foam of the invention, self-extinguishing properties are manifested in the flammability test specified in JIS A9511, and the shape is maintained to some extent by carbonization without being melted and dripped even in contact with a flame. . However, although it was effective for heating for a relatively short time such as a short time in contact with the flame, for example, in the fire performance evaluation prescribed in the Building Standards Law, for example, the ceramic outer wall on the outdoor side The flame is not in direct contact with the foam as in the case of a wall structure in which a material, a heat insulating material made of an aromatic vinyl-based resin foam, and a non-combustible or semi-incombustible plate are arranged on the indoor side, but the outer wall It has been found that when exposed to a high temperature of 400 ° C. to 600 ° C. for a long time by radiant heat through the material, the shape of the foam carbonized material is not maintained and heat may be transferred to the indoor side.
[0008]
[Problems to be solved by the invention]
The present invention has been made in view of the above prior art, and as such, as a heat insulating material for construction, not only when exposed to a flame for a short time, but also when exposed to a high temperature for a long time, the form is maintained to some extent. In addition, there has not yet been found a heat insulating material having sufficient environmental compatibility such as low emission of volatile substances and excellent recyclability.
[0009]
Under such circumstances, the problem to be solved by the present invention is to provide a foam based on an aromatic vinyl-based resin and having the above-mentioned characteristics, and a method for producing the same.
[0010]
[Means for Solving the Problems]
The inventors of the present invention have a foam in which an aromatic vinyl-based resin contains a swellable layered silicate and a phosphorus atom-containing compound and / or a nitrogen atom-containing compound, and retains a certain shape even when exposed to high temperatures. At the same time, it was found that the melt dripping property when being in contact with a flame for a short time was suppressed and the flame retardancy was excellent, and the present invention was achieved. This foam makes it possible to provide a heat insulating material for building that has little emission of volatile substances and is excellent in recyclability because it is a thermoplastic resin. In particular, when a halogen-based flame retardant is not used in combination and a non-halogen-based foaming agent is used, a foam having excellent environmental compatibility is provided.
[0011]
Furthermore, in the present invention, the swellable layered silicate is dispersed finely and further in a molecular form by using the organically treated swellable layered silicate and further combining with a specific aromatic vinyl resin. It becomes possible. Therefore, only by using a relatively small amount of swellable layered silicate, shape retention during heating is imparted, and foam formability and heat insulation are improved.
[0012]
That is, the present invention provides (1) 0.1 to 100 parts by weight of a swellable layered silicate with respect to 100 parts by weight of an aromatic vinyl resin.,Phosphorus atom-containing compounds and / orAt least one selected from the group consisting of a compound containing a triazine skeleton, a diazo compound, and a tetrazole compound1 to 200 parts by weight of a nitrogen atom-containing compound,Furthermore, polyhydric alcohols 1 to 200 parts by weightIt is related with the aromatic vinyl-type resin foam characterized by containing.
[0013]
Furthermore, the present invention provides (2) A swellable layered silicate having a bottom surface spacing of 1.6 nm or more (1))The aromatic vinyl-based resin foam described in the item.
[0014]
Furthermore, the present invention provides (3) A swellable layered silicate having a particle thickness satisfying the following formula (1)Or (2)The aromatic vinyl-based resin foam described in the item.
(The number of particles having a swellable layered silicate particle thickness of 100 nm or less / the total number of particles of the swellable layered silicate) × 100 ≧ 20
Furthermore, the present invention provides (4)X-ray diffraction peak angle value derived from the (001) plane of the swellable layered silicate in the foam is not detected(1) to (3The aromatic vinyl resin foam according to any one of items 1) to 3).
[0015]
Furthermore, the present invention provides (5(1) to (1), wherein a part or all of the aromatic vinyl resin is a resin obtained by polymerizing a compound unit containing a polar group.4The aromatic vinyl resin foam according to any one of items 1) to 3).
[0016]
Furthermore, the present invention provides (6) The swellable layered silicate is treated with one or more organic compounds selected from organic onium salts, organic compounds having a polar group, and silane compounds (1) to (1)5The aromatic vinyl resin foam according to any one of items 1) to 3).
[0017]
Furthermore, the present invention provides (7(1) The phosphorus atom-containing compound is a compound containing a phosphorus atom and a nitrogen atom.6The aromatic vinyl resin foam according to any one of items 1) to 3).
[0019]
Furthermore, the present invention provides (8(1) It is characterized by foaming by adding a non-halogen foaming agent to an aromatic vinyl resin (1) to (7It relates to a method for producing an aromatic vinyl resin foam according to any one of items 1).
[0020]
DETAILED DESCRIPTION OF THE INVENTION
The aromatic vinyl resin used in the present invention is a polymer obtained by polymerizing an aromatic vinyl compound, or obtained by copolymerizing an aromatic vinyl compound and other compounds copolymerizable therewith. Random, block or graft copolymers.
[0021]
Examples of aromatic vinyl compounds include styrene, o-methyl styrene, p-methyl styrene, m-methyl styrene, methyl styrene such as α-methyl styrene, dimethyl styrene such as 2,4-dimethyl styrene, ethyl styrene, diethyl styrene, Halogenated styrene such as isopropyl styrene, monochlorostyrene, dichlorostyrene, monobromostyrene, dibromostyrene, tribromostyrene, styrene derivatives such as pt-butylstyrene, p-hydroxystyrene, styrene-p-glycidyl ether, and divinyl Examples include polyfunctional aromatic vinyl compounds such as benzene. These aromatic vinyl compounds are used alone or in combination of two or more. Among the aromatic vinyl compounds, styrene and styrene derivatives are preferable from the viewpoint of ease of molding of the obtained aromatic vinyl resin, and particularly preferable from the viewpoint of easy reaction at the time of polymerization of the aromatic vinyl resin. Is styrene.
[0022]
Examples of other compounds copolymerizable with the aromatic vinyl compound include unsaturated carboxylic acids such as (meth) acrylic acid, itaconic acid and maleic acid, and unsaturated carboxylic acid anhydrides such as maleic anhydride and itaconic anhydride. , Methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, i-propyl (meth) acrylate, t-butyl (meth) acrylate, 2- (meth) acrylic acid 2- (Meth) acrylic acid alkyl esters such as ethylhexyl and stearyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2,3,5,6 (meth) acrylic acid -(Meth) acrylic acid hydroxyater such as pentahydroxyhexyl, acrylic acid 2,3,4,5-tetrahydroxypentyl Killer ester, maleic acid alkyl ester such as maleic acid monoethyl ester, unsaturated nitrile compound such as acrylonitrile, methacrylonitrile, maleimide, N-methylmaleimide, N-ethylmaleimide, N-phenylmaleimide, N-cyclohexylmaleimide, etc. Maleimide compounds, acrylamide, methacrylamide, N-methylacrylamide, butoxymethylacrylamide, N-propylmethacrylamide, vinyl compounds such as vinyl acetate, diene compounds such as budadiene and isoprene or derivatives thereof, glycidyl (meth) acrylate, Epoxy group-containing unsaturated compounds such as glycidyl itaconate and allyl glycidyl ether, acrylic amine, aminoethyl (meth) acrylate, aminopropyl methacrylate, Propylaminoethyl methacrylate, dimethylaminoethyl methacrylate, ethylaminopropyl methacrylate, phenylaminoethyl methacrylate, cyclohexylaminoethyl methacrylate, aminostyrene, N-vinyldiethylamine, N-acetylvinylamine, allylamine, methallylamine, N -Amino group-containing unsaturated compounds such as methylallylamine, 3-hydroxy-1-propene, 4-hydroxy-1-butene, cis-4-hydroxy-2-butene, trans-4-hydroxy-2-butene, 3- Hydroxyl-containing unsaturated compounds such as hydroxy-2-methyl-1-propene, 2-hydroxy-2-methyl-1-propene, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, vinyl oxazoline, 2-isopropeni Examples thereof include oxazoline group-containing unsaturated compounds such as ru-oxazoline and 2-acryloyl-oxazoline. These can be used alone or in admixture of two or more.
[0023]
Aromatic vinyl resins can be used alone or in admixture of two or more. When an aromatic vinyl resin is used alone, a polystyrene homopolymer is preferable from the viewpoint of foam moldability, and (meth) acrylic acid copolymerized polystyrene, maleic anhydride copolymerized polystyrene, styrene-acrylonitrile copolymer, It is preferable from the viewpoints of dispersibility of the swellable layered silicate in the foam from which an aromatic vinyl-based resin containing a polar group such as a styrene-vinyloxazoline copolymer is obtained, and shape retention during heating. When two or more kinds are used in combination, polystyrene homopolymer and (meth) acrylic acid copolymer polystyrene, maleic anhydride copolymer polystyrene, styrene-acrylonitrile copolymer, styrene-vinyloxazoline copolymer, etc. Aromatic vinyl resin using one or more selected from aromatic vinyl resins containing polar groups, or (meth) acrylic acid copolymerized polystyrene, maleic anhydride copolymerized polystyrene, styrene-acrylonitrile copolymer An aromatic vinyl resin used in combination of two or more selected from aromatic vinyl resins containing a polar group such as a polymer and a styrene-vinyl oxazoline copolymer is preferably used.
[0024]
The swellable layered silicate used in the present invention mainly comprises a tetrahedral sheet of silicon oxide and an octahedral sheet of mainly metal hydroxide, and the tetrahedral sheet and the octahedral sheet form a unit layer. A single layer, a plurality of layers may be laminated between layers to form primary particles, or aggregate particles of primary particles (secondary particles) may be present. In addition, “swellability” means that the bottom surface spacing of the layered silicate increases when contacted with water, polar organic compounds, polar polymers, nonpolar organic compounds, nonpolar polymers, etc. Alternatively, it refers to the property of cleaving or peeling in the state where the unit layer or the unit layer is laminated. However, a unit layer surface that replaces cations between layers with organic cations such as organic onium ions when swelling, depending on the type of non-polar organic compound, non-polar polymer, and polar organic compound It is possible to swell by organic treatment such as treatment with an organic compound or a silane compound having an interaction with the.
Examples of the swellable layered silicate include, for example, smectite group clay and swellable mica.
[0025]
The smectite clay is represented by the following general formula (1)
X_0.2~_0.6Y₂~_ThreeZ_FourO_Ten(OH)₂・ NH₂O (1)
(However, X is at least one selected from the group consisting of K, Na, 1 / 2Ca, and 1 / 2Mg, and Y is a group consisting of Mg, Fe, Mn, Ni, Zn, Li, Al, and Cr. One or more selected from Z, and Z is one or more selected from the group consisting of Si and Al.₂O represents a water molecule bonded to an interlayer ion, while n represents a natural or synthesized material that varies significantly depending on the interlayer ion and relative humidity. Specific examples of the smectite group clay include, for example, montmorillonite, beidellite, nontronite, saponite, iron saponite, hectorite, soconite, stevensite, bentonite, and the like, or substitution products, derivatives, or mixtures thereof. .
[0026]
Further, the swellable mica is represented by the following general formula (2)
X_0.5~_1.0Y₂~_Three(Z_FourO_Ten) (F, OH)₂          (2)
(However, X is at least one selected from the group consisting of Li, Na, K, Rb, Ca, Ba, and Sr, and Y is selected from the group consisting of Mg, Fe, Ni, Mn, Al, and Li) And Z is one or more selected from the group consisting of Si, Ge, Al, Fe, and B.) or natural or synthesized. These are water, a polar organic compound that is compatible with water at an arbitrary ratio, and a substance that has a property of swelling in a mixed solvent of water and the polar organic compound. For example, lithium teniolite, sodium Type teniolite, lithium type tetrasilicon mica, sodium type tetrasilicon mica and the like, or a substituted product, a derivative thereof, or a mixture thereof.
[0027]
Some of the above swellable mica have a structure similar to vermiculites, and such vermiculites and the like can also be used. The vermiculite-equivalent products are classified into 3 octahedron type and 2 octahedron type, and the following general formula (3)
(Mg, Fe, Al)₂~_Three(Si_4-xAl_x) O_Ten(OH)₂・ (M⁺, M²⁺ _1/2)_x・ NH₂O
(3)
(Wherein M is an exchangeable cation of an alkali or alkaline earth metal such as Na and Mg, x = 0.6 to 0.9, and n = 3.5 to 5). .
[0028]
Swellable layered silicates may be used alone or in combination of two or more. Among these, smectite group clay and swellable mica are preferable from the viewpoint of dispersibility in the obtained foam. More preferably, the swellable mica having sodium ions between layers such as montmorillonite, bentonite, hectorite, synthetic smectite, and swellable fluorine mica has a moldability during the production of an aromatic vinyl resin foam and a shape retention during heating. From the point of view of properties.
[0029]
The crystal structure of the swellable layered silicate is preferably a highly pure layer that is regularly stacked in the c-axis direction, but so-called mixed layer minerals in which the crystal period is disturbed and a plurality of types of crystal structures are mixed can also be used.
[0030]
The swellable layered silicate is improved in dispersibility of the swellable layered silicate in the resulting foam because the affinity with the aromatic vinyl resin is increased by the organic treatment. It is effective that the distance between the bottom surfaces of the salts is increased and the shape retention property improving effect during heating can be further exhibited. Furthermore, by appropriately selecting the type of swellable lamellar silicate, the method of organic treatment, the type of treatment agent, the type of aromatic vinyl resin, the production method, etc., the swellable lamellar silicate has a unit layer or unit layer. It becomes easy to finely disperse as laminated particles. By improving the dispersibility in this way, even if a relatively small amount is added, the resulting foam has an improvement effect such as improved shape retention during heating, and further improved foam moldability and heat insulation. Is preferable because it can be further exhibited.
[0031]
The method for organically treating the swellable layered silicate is, for example, a method in which an exchangeable cation existing between layers of the swellable layered silicate is exchanged with an organic onium ion by contacting with the organic onium salt, a swellable layered silicate And a method in which all or part of the compound molecule is inserted between layers by contacting with an organic compound having a hydrogen-bonding polar group, and a swelling layered silicate swells in a state in which a unit layer or a plurality of unit layers are laminated. And a method of bringing them into contact with a silane compound, or a method of combining two or more of these organic treatment methods.
[0032]
The method of exchanging exchangeable cations existing between the layers of the swellable layered silicate with organic onium ions can be produced by reacting the swellable layered silicate and organic onium ions by a known method. In order to introduce an organic onium ion, an organic onium salt containing the ion is used. Examples of such salts include salts of organic onium ions described later and anions such as chlorine ions, bromine ions, nitrate ions and carboxylate ions. As a method for introducing an organic onium ion, for example, a swellable layered silicate is added and swollen in a dispersion medium such as an organic compound having polarity such as water, methanol, ethanol, etc., and then an organic onium salt is added. Alternatively, the swellable layered silicate is added and swollen in a dispersion medium such as water, methanol, ethanol, or other polar organic compound in which organic onium ions have been dispersed in advance, and the interlayer ions of the layered silicate are made organic. Examples thereof include a method of performing an ion exchange reaction with onium ions, or a method of directly reacting a swellable layered silicate with a liquid or molten organic onium salt.
[0033]
The amount of organic onium ions used for the swellable layered silicate is the type of aromatic vinyl resin, the type of swellable layered silicate, the affinity between the swellable layered silicate and the aromatic vinyl resin, and the swellable layered silicate. It can be appropriately adjusted according to the amount of salt added, the bottom surface spacing of the swellable layered silicate, and the like. Therefore, although the amount of organic onium ions used is not generally limited by numerical values, the amount of organic onium ions used with respect to 100 parts by weight of the swellable layered silicate is preferably 0.1 to 200 parts by weight. Preferably it is 1-150 weight part, More preferably, it is 5-120 weight part, Most preferably, it is 10-100 weight part. If the amount of organic onium ions used is less than 0.1 parts by weight, the intended treatment effects such as dispersibility of the swellable layered silicate tend to be insufficient. In addition, if the amount of organic onium ions used exceeds 200 parts by weight, the fine dispersion effect does not change, while the organic onium ions impair the excellent characteristics of the aromatic vinyl resin and cause a reduction in flame retardancy. Therefore, it is not necessary to use more than 200 parts by weight.
[0034]
Examples of organic onium ions include ammonium ions, phosphonium ions, and sulfonium ions. Of these, ammonium ions and phosphonium ions are preferably used. As the onium ion, any of primary onium, secondary onium, tertiary onium, and quaternary onium may be used, but since the dispersibility of the swellable layered silicate in the resin is excellent, the quaternary phosphonium ion, quaternary Quaternary onium ions such as ammonium ions are preferred. Since these organic onium ions have the effect of entering between the layers of the swellable layered silicate and increasing the distance between the bottom surfaces, ions having a large molecular weight are preferred, and ions having 6 or more carbon atoms are particularly preferred. More preferred are ions having 8 or more carbon atoms.
[0035]
Quaternary phosphonium ions include dodecyltributylphosphonium, hexadecyltributylphosphonium, octadecyltributylphosphonium, dodecyltrimethylphosphonium, hexadecyltrimethylphosphonium, octadecyltrimethylphosphonium, didodecyldibutylphosphonium, dihexadecyldibutylphosphonium, dioctadecyldibutylphosphonium, dioctyl Examples include dodecyldimethylphosphonium, dihexadecyldimethylphosphonium, dioctadecyldimethylphosphonium, benzyldibutyldodecylphosphonium, dodecyltriphenylphosphonium, hexadecyltriphenylphosphonium, octadecyltriphenylphosphonium, and the like.
[0036]
Examples of the primary ammonium ion include decyl ammonium, dodecyl ammonium, octadecyl ammonium, oleyl ammonium, benzyl ammonium, and the like.
[0037]
Examples of secondary ammonium ions include methyl dodecyl ammonium and methyl octadecyl ammonium.
[0038]
Tertiary ammonium ions include dimethyl dodecyl ammonium, dimethyl octadecyl ammonium, and the like.
[0039]
Quaternary ammonium ions include benzyltrialkylammonium ions such as benzyldimethyldodecylammonium, benzyldimethyltetradecylammonium and benzyldimethyloctadecylammonium, alkyltrimethylammonium ions such as trimethyloctylammonium, trimethyldodecylammonium and trimethyloctadecylammonium, and dimethyldioctylammonium. Dimethyldialkylammonium ions such as dimethyldidodecylammonium and dimethyldioctadecylammonium, trialkylmethylammonium ions such as trioctylmethylammonium and tridodecylmethylammonium, diallyldimethylammonium and methacryloxyethyltrimethylammonium Examples include ammonium ions having a carbon-carbon double bond, ammonium ions having an OH group such as dimethyldiethanolammonium and methyltriethanolammonium, other dimethylbenzylphenylammonium ions, benzalkonium ions, and benzethonium ions. .
[0040]
Besides these, from melamine, aniline, p-phenylenediamine, α-naphthylamine, p-aminodimethylaniline, benzidine, pyridine, piperidine, 6-aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, etc. Examples thereof include induced ammonium ions.
These organic onium ions may be used alone or in combination of two or more.
[0041]
As a method for inserting all or part of organic compound molecules having hydrogen bonding polar groups between layers of the swellable layered silicate, for example, after swelling the layered silicate in a dispersion medium such as water , A method of contacting an organic compound having a hydrogen bonding polar group, a method of directly contacting a swellable layered silicate with an organic compound having a hydrogen bonding polar group, and a method of contacting the swellable layered silicate with an organic onium ion. After the organic onium ion-modified swellable layered silicate is obtained, it is swollen in a dispersion medium such as water or an organic compound, and then contacted with an organic compound having a hydrogen bonding polar group. Examples include a method in which an organic onium ion-modified swellable layered silicate is brought into contact with an organic onium ion and then directly brought into contact with an organic compound having a hydrogen bonding polar group.
[0042]
The compound having a hydrogen-bonding polar group refers to a compound having one or more hydrogen-bonding polar groups in the main chain and / or side chain. The hydrogen-bonding polar group is bonded to the main chain, side chain, or terminal of the compound, and is particularly bonded to the terminal in that the bottom surface spacing of the swellable layered silicate can be greatly increased. Is preferred. A hydrogen-bonding polar group is a group in which electrons are localized in a molecule and charge is biased. Examples of the polar group include a hydroxyl group (OH), a halogen group (F, Cl, Br, I), a carboxyl group (COOH), a thiol group (SH), an epoxy group, or a primary, secondary, or tertiary group. Amine (NH₂ , NH, N). The compound having a hydrogen-bonding polar group has, for example, one or more polar groups, a saturated or unsaturated linear or branched structure, and the main chain and / or side thereof. A compound that does not contain or contains an aromatic ring in the chain. Examples of the compound having a hydrogen bonding polar group include alcohols, glycols, organic carboxylic acids, organic carboxylates, polyethylene having polar groups such as OH, COOH, Cl, and epoxy groups at some or all ends. Examples thereof include polyolefins such as polypropylene, and compounds derived from these having a linear or branched structure and not containing an aromatic ring and / or containing an aromatic ring.
[0043]
Organic compounds having hydrogen-bonding polar groups tend to broaden the layers of the swellable layered silicate as the mixing ratio increases. The amount of the organic compound having a polar group is the kind of the aromatic vinyl resin, the kind of the swellable layered silicate, the affinity between the swellable layered silicate and the aromatic vinyl resin, and the addition of the swellable layered silicate. It can be suitably prepared according to the amount, the bottom spacing of the swellable layered silicate, the added amount of the phosphorus atom-containing compound and / or the nitrogen atom-containing compound described later. Therefore, the amount of the organic compound having a hydrogen-bonding polar group is not generally limited by numerical values, but is preferably 10 parts by weight or more with respect to 100 parts by weight of the swellable layered silicate. If too much is used, flame retardancy may be reduced. The organic compound having a hydrogen bonding polar group forms a hydrogen bond with the swellable layered silicate by the polar group. And at least one part intervenes between the layers of the swellable layered silicate.
[0044]
Furthermore, an organic compound, oligomer, or polymer that does not have a polar group or has a low polarity may be used in combination with an organic compound having a hydrogen bonding polar group.
[0045]
As a method of treating the swellable lamellar silicate with water or a polar organic compound, for example, the swellable lamellar silicate is swollen into a unit layer or a state in which the unit layers are laminated, and then treated with a silane compound. A method of adding a silane-based compound after swelling is mentioned. The swelling of the swellable layered silicate in the dispersion medium can be achieved by sufficiently stirring and dispersing the swellable layered silicate in the dispersion medium. In this way, the swellable stratified silicate is swelled to break up the aggregated state, and after the unit layer or the plurality of unit layers are laminated, the silane compound is added and stirred. .
[0046]
As the silane compound, any one generally used can be used, and the following general formula (4)
Y_nSiX_4-n          .... (4)
It is represented by N in General formula (4) is an integer of 0-3, Y is a C1-C25 hydrocarbon group which may have a substituent. Examples of the substituent when the hydrocarbon group having 1 to 25 carbon atoms has a substituent include, for example, a group bonded by an ester bond, a group bonded by an ether bond, an epoxy group, an amino group, and a carboxyl group , A group having a carbonyl group at the terminal, an amide group, a mercapto group, a group bonded by a sulfonyl bond, a group bonded by a sulfinyl bond, a nitro group, a nitroso group, a nitrile group, a halogen atom, a hydroxyl group, etc. . One of these may be substituted, or two or more may be substituted.
[0047]
X is a hydrolyzable group and / or a hydroxyl group. Examples of the hydrolyzable group include an alkoxy group, an alkenyloxy group, a ketoxime group, an acyloxy group, an amino group, an aminoxy group, an amide group, and a halogen atom. It is 1 or more types selected from. In general formula (4), when n or 4-n is 2 or more, n Y or 4-n X may be the same or different. The hydrocarbon group is a linear or branched (that is, having a side chain) saturated or unsaturated monovalent or polyvalent aliphatic hydrocarbon group, an aromatic hydrocarbon group, or an alicyclic hydrocarbon group. Meaning, for example, a polyvalent hydrocarbon group such as an alkyl group, an alkenyl group, an alkynyl group, a phenyl group, a naphthyl group, a cycloalkyl group, and an alkylene group, an alkenylene group, an alkynylene group, a phenylene group, a naphthylene group, and A cycloalkylene group etc. are mentioned.
[0048]
In the general formula (4), examples of the case where Y is a hydrocarbon group having 1 to 25 carbon atoms include those having a linear long-chain alkyl group such as decyltrimethoxysilane, and methyltrimethoxysilane. Those having a lower alkyl group, those having an unsaturated hydrocarbon group such as 2-hexenyltrimethoxysilane, those having an alkyl group having a side chain such as 2-ethylhexyltrimethoxysilane, phenyltriethoxysilane Examples thereof include those having a phenyl group, those having a naphthyl group such as 3-β-naphthylpropyltrimethoxysilane, and those having an aralkyl group such as p-vinylbenzyltrimethoxysilane.
[0049]
Examples of the case where Y is a group having a vinyl group among hydrocarbon groups having 1 to 25 carbon atoms include vinyltrimethoxysilane, vinyltrichlorosilane, and vinyltriacetoxysilane. An example of the case where Y is a group having a group substituted with an ester group is γ-methacryloxypropyltrimethoxysilane. Examples of the case where Y is a group having a group substituted with a group bonded with an ether group include γ-polyoxyethylenepropyltrimethoxysilane and 2-ethoxyethyltrimethoxysilane.
[0050]
An example of the case where Y is a group substituted with an epoxy group includes γ-glycidoxypropyltrimethoxysilane. Examples of when Y is a group substituted with an amino group include γ-aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropyltrimethoxysilane, and γ-anilinopropyltrimethoxysilane. Can be mentioned. An example of the case where Y is a group substituted with a group having a carbonyl group at the terminal includes γ-ureidopropyltriethoxysilane. An example of the case where Y is a group substituted with a mercapto group includes γ-mercaptopropyltrimethoxysilane. An example of the case where Y is a group substituted with a halogen atom includes γ-chloropropyltriethoxysilane.
[0051]
An example of the case where Y is a group having a group substituted with a group bonded with a sulfonyl group includes γ-phenylsulfonylpropyltrimethoxysilane. An example of the case where Y is a group having a group substituted with a group bonded with a sulfinyl group includes γ-phenylsulfinylpropyltrimethoxysilane. An example of the case where Y is a group substituted with a nitro group includes γ-nitropropyltriethoxysilane. An example of the case where Y is a group substituted with a nitroso group includes γ-nitrosopropyltriethoxysilane. Examples of the case where Y is a group substituted with a nitrile group include γ-cyanoethyltriethoxysilane and γ-cyanopropyltriethoxysilane.
[0052]
An example of the case where Y is a group substituted with a carboxyl group includes γ- (4-carboxyphenyl) propyltrimethoxysilane. In addition to the above, a silane compound in which Y is a group having a hydroxyl group can also be used. Such an example includes N, N-di (2-hydroxyethyl) amino-3-propyltriethoxysilane. The hydroxyl group can also be in the form of a silanol group (SiOH). Substitutes or derivatives of silane-based compounds can also be used. These silane compounds may be used alone or in combination of two or more.
[0053]
When the silane compound introduced into the swellable layered silicate further has a reactive functional group such as a hydroxyl group, a carboxyl group, an amino group, an epoxy group, or a vinyl group, such a reactive group It is also possible to add further compounds capable of reacting with and react this compound with this reactive group. In this way, the chain length of the functional group chain of the silane compound introduced into the swellable layered silicate can be increased, or the polarity can be changed. In this case, as the compound to be added, the above silane compound itself may be used, but is not limited thereto, and any compound may be used according to the purpose, for example, an epoxy group-containing compound, an amino group Examples thereof include a containing compound, a carboxyl group-containing compound, an acid anhydride group-containing compound, and a hydroxyl group-containing compound.
[0054]
The amount of silane compound used depends on the type of aromatic vinyl resin, the type of swellable layered silicate, the affinity between the swellable layered silicate and the aromatic vinyl resin, the amount of swellable layered silicate added, and the swelling It can be suitably prepared according to the bottom surface spacing of the functional layered silicate, the addition amount of the phosphorus atom-containing compound and / or the nitrogen atom-containing compound described later, and the like. If necessary, a plurality of types of silane compounds having different functional groups can be used in combination. Accordingly, the amount of the silane compound used is not generally limited by a numerical value, but is 0.1 to 200 parts by weight, preferably 0.2 to 150 parts by weight with respect to 100 parts by weight of the swellable layered silicate. Part, more preferably 0.3 to 120 parts by weight, still more preferably 0.5 to 100 parts by weight. When the amount of the silane compound is less than 0.1 parts by weight, the intended treatment effects such as dispersibility of the swellable layered silicate tend to be insufficient. When the amount is 200 parts by weight or more, the effect is not changed, and the flame retardancy may be lowered. Therefore, it is not necessary to add more than 200 parts by weight.
[0055]
When a dispersion medium is used when producing an organically treated swellable layered silicate, it can be used while being swelled in the dispersion medium, or it is organically treated by removing the dispersion medium. It is also possible to use after removing the swellable layered silicate. Furthermore, when a dispersion medium is not used, it can be used directly as it is, or it can be swollen in a dispersion medium. Furthermore, the dispersion medium can be used as a foaming agent as required.
[0056]
As the swellable layered silicate used for the organically treated swellable layered silicate, montmorillonite, synthetic smectite, and swellable fluorinated mica are preferable from the viewpoint of shape retention during heating, etc. A method of treating with an organic onium ion is preferable from the viewpoint of dispersibility in an aromatic vinyl resin. Further, montmorillonite treated with a quaternary ammonium ion such as dialkyl (C14-18) methylammonium ion, and swellable fluorine mica are particularly preferred from the viewpoint of shape retention during heating, and the like. Dialkyl (C14-18) methylammonium ion A swellable fluorine mica treated with a quaternary ammonium ion such as the above is preferred in that the effect of maintaining the shape during heating is exhibited with the addition of a relatively small amount.
[0057]
The affinity between the swellable layered silicate and the aromatic vinyl resin is such that a part or all of the bottom surface spacing of the swellable layered silicate in the aromatic vinyl resin foam of the present invention is 1.6 nm or more. The shape retention during heating and the amount added to express the characteristics are preferable from the viewpoint that the bottom surface spacing may be reduced as compared with a swellable layered silicate having less than 1.6 nm. More preferably, it is 2 nm or more, and particularly preferably 2.5 nm or more. The term “bottom surface spacing” as used herein refers to the distance from the bottom surface of a unit layer to the bottom surface of the next unit layer in the c-axis direction in the crystal structure of the swellable layered silicate. The interval between the bottom surfaces can be confirmed by a small angle X-ray diffraction method (SAXS) or the like. That is, the X-ray diffraction peak angle value derived from the (001) plane of the swellable layered silicate is measured by SAXS, and is calculated by applying the Bragg equation to obtain the bottom surface interval.
[0058]
The bottom surface spacing and X-ray diffraction measurement of the layered silicate compound are described in, for example, “Clay Handbook” (edited by the Japan Clay Society: Gihodo Publishing). When the swellable lamellar silicate swells and the bottom surface spacing is about 4 to 5 nm or more, and further when dispersed in a unit layer or a shape close to the unit layer, that is, substantially in a molecular form, The X-ray diffraction peak angle value derived from the (001) plane is difficult to read or cannot be detected. Therefore, the fact that the swellable layered silicate is dispersed in a molecular form is also confirmed by the fact that the X-ray diffraction peak angle value derived from the (001) plane of the swellable layered silicate is not detected.
[0059]
In order to set the spacing between the bottom surfaces of the swellable layered silicate in the aromatic vinyl-based resin foam to 1.6 nm or more, for example, the organic treatment is performed in advance as described above to swell the bottom spacing to 1.6 nm or more. A method using a porous layered silicate, a method using an aromatic vinyl resin containing a polar group in part or all of an aromatic vinyl resin, an aromatic vinyl after swelling a swellable layered silicate with a dispersion medium Examples thereof include a method of adding to a resin and melt-kneading, a method of adding a swellable layered silicate when synthesizing an aromatic vinyl resin, and a method of combining them.
[0060]
In the aromatic vinyl-based resin foam of the present invention, the swellable layered silicate particle thickness in the foam satisfies the following formula, compared to a case where the following formula is not satisfied, a relatively small amount of the swellable layered silicate Even when silicate is added, it is preferable in that the effect of shape retention during heating is exhibited. The following formula represents the ratio of particles having a thickness of 100 nm or less among the particles of the swellable layered silicate dispersed in the foam, and the higher the value, the finer the swellable layered silicate is dispersed. .
[0061]
(The number of particles having a swellable layered silicate particle thickness of 100 nm or less / the total number of particles of the swellable layered silicate) × 100 ≧ 20
Here, the thickness of the layered silicate particles is the shortest dimension among the vertical, horizontal, and height dimensions of the particles when the swellable layered silicate is dispersed in a state where a unit layer or a plurality of unit layers are laminated. Say. That is, it corresponds to the thickness when the particles are regarded as a plate.
[0062]
The thickness of the swellable layered silicate particles can be determined by photographing the dispersion state of the particles in the foam using a transmission electron microscope or the like and measuring using a ruler or the like.
[0063]
The ratio of the number of particles having a swellable layered silicate particle thickness of 100 nm or less is 20 or more, preferably 30 or more, and more preferably 50 or more.
[0064]
Furthermore, in the aromatic vinyl resin foam of the present invention, the fact that the swellable layered silicate is substantially dispersed in a molecular shape can be maintained by using a relatively small amount of the swellable layered silicate. It is particularly preferable in that it is improved in properties, strength characteristics are imparted, and heat insulation is improved. Here, the swellable layered silicate is substantially dispersed in the form of a molecule means that the layered silicate is dispersed in a state close to the unit layer although the unit layer or a plurality of unit layers are laminated. Say that. The fact that the swellable layered silicate is substantially dispersed in a molecular form means that the X-ray diffraction peak angle value derived from the (001) plane of the swellable layered silicate is not detected, or a transmission electron microscope, etc. Can be confirmed by photographing the dispersion state of the particles in the foam and measuring that the thickness of the particles is a unit layer of the swellable layered silicate used or a thickness close to the unit layer.
[0065]
Examples of a method for dispersing the particle thickness of the swellable layered silicate in the aromatic vinyl resin foam to 100 nm or less, and substantially on the molecule include, for example, a swellable layered silicate that has been previously subjected to an organic treatment as described above. A method using salt, more preferably a method of giving a high shearing force during melt kneading, an aromatic vinyl resin containing a polar group in part or all of the aromatic vinyl resin, more preferably high during melt kneading A method of applying a shearing force, a method of melt-kneading a combination of an aromatic vinyl resin containing a polar group in a part or all of an aromatic vinyl resin and a swellable layered silicate that has been previously organically treated as described above, Preferably, the swelling layered silicate is swelled to a particle thickness of 100 nm or less with a dispersion medium and then added to the aromatic vinyl resin and melt-kneaded. When synthesizing the aromatic vinyl resin, an organic treatment is preferably performed. A method of adding the swellable layered silicate, and further, a method in which a combination of these.
[0066]
The content of the swellable layered silicate in the aromatic vinyl resin foam is 0.1 to 100 parts by weight with respect to 100 parts by weight of the aromatic vinyl resin in the aromatic vinyl resin foam, preferably Is 0.5 to 80 parts by weight, more preferably 1 to 60 parts by weight. When the content of the swellable layered silicate is less than 0.1 part by weight, the effect of improving the shape retention during heating is not seen, and when it exceeds 100 parts by weight, the moldability of the foam and the toughness of the resulting foam are obtained. Etc. are not preferred because they tend to decrease. Here, the content of the swellable layered silicate is such that the obtained aromatic vinyl resin foam is incinerated by, for example, heating at 650 ° C. for 2 hours to remove organic substances, and the remaining swellable layered silicate is left. The method of measuring the weight of the resin, the aromatic vinyl resin foam is dissolved in a solvent capable of dissolving additives other than the aromatic vinyl resin and, if necessary, the swellable layered silicate, and then filtered and centrifuged. The swellable layered silicate can be taken out, and then ashed if necessary, and the weight thereof can be measured.
[0067]
In the present invention, a non-halogen compound as described below is used for the purpose of imparting shape retention and flame retardancy upon heating. That is, the phosphorus atom-containing compound used in the present invention refers to a compound containing a phosphorus atom in the molecule. Specific examples thereof include phosphorous oxides such as phosphorous trioxide, phosphorous tetroxide and phosphorous pentoxide, phosphoric acid compounds such as phosphoric acid, phosphorous acid, hypophosphorous acid, metaphosphoric acid, pyrophosphoric acid, polyphosphoric acid, mono Ammonium phosphate, diammonium phosphate, ammonium phosphate such as ammonium polyphosphate, melamine monophosphate, melamine diphosphate, melamine phosphate such as melamine polyphosphate, lithium phosphate, sodium phosphate, potassium phosphate, calcium phosphate, phosphorus Phosphate salts such as metal phosphates such as magnesium acid, trimethyl phosphate, triethyl phosphate, tributyl phosphate, tri (2-ethylhexyl) phosphate, tributoxyethyl phosphate, monoisodecyl phosphate, 2- Aliphatic phosphate esters such as acryloyloxyethyl acid phosphate and 2-methacryloyloxyethyl acid phosphate, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, tris (isopropylphenyl) phosphate, tris (phenylphenyl) Phosphate, trinaphthyl phosphate, cresyl diphenyl phosphate, xylenyl diphenyl phosphate, diphenyl (2-ethylhexyl) phosphate, di (isopropylphenyl) phenyl phosphate, diphenyl-2-acryloyloxyethyl phosphate, diphenyl-2-methacryloyloxyethyl phosphate Aromatic phosphates such as 2 for phosphate groups represented by the following general formula (5) Phosphoric acid esters having the above,
[0068]
[Chemical 1]

(Wherein R₁Is a residue such as resorcinol, hydroquinone, bisphenol A, R₂Are a phenyl group, a tolyl group, a xylyl group and the like, which may be the same or different, and n is an integer of 1 or more)
[0069]
The phosphoric acid esters represented by the general formula (5) include resorcinol bis (diphenyl phosphate), resorcinol bis (dixylenyl phosphate), resorcinol bis (dicresyl phosphate), hydroquinone bis (diphenyl phosphate). , Hydroquinone bis (dicylenyl phosphate), hydroquinone bis (dicresyl phosphate), bisphenol A bis (diphenyl phosphate), bisphenol A bis (dixylenyl phosphate), bisphenol A bis (dicresyl phosphate), etc. Aromatic di (phosphate ester) s (in the above general formula 1, n = 1), poly (resorcinol / phenyl phosphate), poly (resorcinol / cresyl phosphate), poly (resin Lucinol / xylenyl phosphate), poly (hydroquinone / phenyl phosphate), poly (hydroquinone / cresyl phosphate), poly (hydroquinone / xylenyl phosphate), poly (bisphenol A / phenyl phosphate), poly (bisphenol A / crete) Phosphoric esters such as aromatic poly (phosphate esters) such as di (phosphate) and poly (bisphenol A / xylenyl phosphate) (wherein n is 2 or more in the above general formula 1), phosphazenes, polyphosphazenes And phosphazenes such as phosphate amines and phosphate amides.
[0070]
When the phosphorus compound is in the form of particles, powders, plates, needles, etc., melamine resin, phenol resin, guanamine resin, epoxy resin, urethane resin, urea resin, silicone resin, silane cup It may be one that has been surface-treated with a compound that can be surface-coated or surface-treated, such as one or more compounds selected from ring agents and the like.
[0071]
In the phosphorous compound, from the viewpoint of shape retention during combustion, phosphorous and nitrogen atoms such as phosphates such as ammonium phosphate, ammonium polyphosphate, melamine phosphate, melamine polyphosphate, and phosphazenes such as phosphazene and polyphosphazene are contained. Compounds containing are preferred. Further, phosphates that have been surface-treated are more preferable.
[0072]
The compound containing a nitrogen atom used in the present invention refers to a compound containing a nitrogen atom in the molecule, and a specific example thereof is a compound having a triazine structure composed of a carbon atom and a nitrogen atom. Is a melamine derivative such as melamine, methylol melamines, cyanuric acid, methyl cyanurate, diethyl cyanurate, trimethyl cyanurate, triethyl cyanurate, isocyanuric acid, methyl isocyanurate, N, N'-diethyl isocyanurate, trismethyl isocyanurate Cyanuric acid such as trisethyl isocyanurate, bis (2-carboxyethyl) isocyanurate, 1,3,5-tris (2-carboxyethyl) isocyanurate, tris (2,3-epoxypropyl) isocyanurate, isocyanuric acid Or Derivative, and salts with melamine and melamine cyanurate (derivative) and (iso) cyanuric acid (derivatives).
[0073]
Furthermore, tetrazole compounds such as diazo compounds, tetrazole guanidine salts, tetrazole piperazine salts, tetrazole ammonium salts, and the like, and tetrazole compounds such as tetrazole metal salts such as tetrazole sodium salt and tetrazole manganese salt, for example, 5,5′-bistetrazole 2 guanidine salt, 5,5′-bistetrazole diammonium salt, 5,5′-bistetrazole diaminoguanidine salt, 5,5′-bistetrazole piperazine salt.
[0074]
In the nitrogen atom-containing compound, a triazine skeleton-containing compound is preferable from the viewpoint of shape retention during combustion, and specifically, melamine, cyanuric acid, isocyanuric acid, melamine cyanurate, and the like are preferable.
[0075]
In the present invention, one or more compounds selected from a phosphorus atom-containing compound or a nitrogen atom-containing compound are used. From the viewpoint of improving shape retention during heating, a phosphorus atom-containing compound and a nitrogen atom-containing compound are used. Both of these are preferably used in combination of one or more of each.
[0076]
Content of the 1 type (s) or 2 or more types of compound chosen from a phosphorus atom containing compound or a nitrogen atom containing compound is 1-200 weight part with respect to 100 weight part of aromatic vinyl resin, Preferably it is 5-150. Part by weight, more preferably 10 to 120 parts by weight. If the amount of the compound is less than 1 part by weight, the self-extinguishing effect is not observed, and if it exceeds 200 parts by weight, the moldability of the foam becomes difficult.
[0077]
Furthermore, in the present invention, polyhydric alcohols are used in combination for the purpose of further enhancing the shape retention effect during combustion and heating. Polyhydric alcohols are compounds containing two or more hydroxyl groups in one molecule. Specific examples thereof include pentaerythritols such as monopentaerythritol, dipentaerythritol and tripentaerythritol, ethylene glycol, diethylene glycol. , Propylene glycol, polyethylene glycol, polypropylene glycol, glycols such as a copolymer of ethylene glycol and propylene glycol, glycerin, resorcinol, trimethylolpropane and the like. Of the polyhydric alcohols, monopentaerythritol is preferred from the viewpoint of maintaining the shape during combustion.
[0078]
Content of polyhydric alcohol is 1-200 weight part with respect to 100 weight part of aromatic vinyl-type resin, Preferably it is 5-150 weight part, More preferably, it is 10-120 weight part. If the content is less than 1 part by weight, the self-extinguishing effect is not seen, and if it exceeds 200 parts by weight, the moldability of the foam becomes difficult, which is not preferable.
[0079]
In the present invention, each of the phosphorus atom-containing compound and the polyhydric alcohol is used alone or in combination of two or more, and each of the nitrogen atom-containing compound and the polyhydric alcohol is used alone or in combination, respectively. It can be used in combination of one or more species, and any of phosphorus atom-containing compounds, nitrogen atom-containing compounds and polyhydric alcohols can be used alone or in combination of two or more. It is more preferable to use one or both of the containing compound and the polyhydric alcohol in combination.
[0080]
The blowing agent used in the present invention is not particularly limited, and examples thereof include saturated hydrocarbons exemplified by propane, n-butane, i-butane, n-pentane, i-pentane, neopentane, dimethyl ether, diethyl ether, methyl, and the like. Ethers exemplified by ethyl ether, isopropyl ether, n-butyl ether, diisopropyl ether, furan, furfural, 2-methyl furan, tetrahydrofuran, tetrahydropyran, dimethyl ketone, methyl ethyl ketone, diethyl ketone, methyl n-propyl ketone, methyl n -Ketones exemplified by butyl ketone, methyl i-butyl ketone, methyl n-amyl ketone, methyl n-hexyl ketone, ethyl n-propyl ketone, ethyl n-butyl ketone, methanol, ethanol, pro Alcohols exemplified by alcohol, i-propyl alcohol, butyl alcohol, i-butyl alcohol, t-butyl alcohol, formic acid methyl ester, formic acid ethyl ester, formic acid propyl ester, formic acid butyl ester, formic acid amyl ester, methyl propionate Esters, carboxylic acid esters exemplified by propionic acid ethyl ester, azodicarbonamide, azobisisobutyronitrile, N, N′-dinitrosopentamethylenetetramine, p-toluenesulfonylhydrazine, p, p′-oxybis ( Organic blowing agents exemplified by benzenesulfohydrazide), methyl chloride, ethyl chloride, trichlorofluoromethane (R11), dichlorodifluoromethane (R12), chlorodifluoromethane (R22), tetrachlorodi Freon-based foaming agents exemplified by luroethane (R112), dichlorofluoroethane (R141b), chlorodifluoroethane (R142b), difluoroethane (R152a), HFC-245fa, HFC-236ea, HFC-245ca, HCFC-225ca, water, Examples thereof include inorganic foaming agents exemplified by carbon dioxide, nitrogen, air and the like. These can be used alone or in admixture of two or more.
[0081]
Among these, the use of the non-halogen-based foaming agent described below is desirable because the environmental compatibility of the foam of the present invention can be further improved. That is, saturated hydrocarbons exemplified by propane, n-butane, i-butane, n-pentane, i-pentane, neopentane, etc., dimethyl ether, diethyl ether, methyl ethyl ether, isopropyl ether, n-butyl ether, diisopropyl ether, furan , Furfural, 2-methylfuran, tetrahydrofuran, ethers exemplified by tetrahydropyran, N, N′-dinitrosopentamethylenetetramine, N, N′-dimethyl N, N′-dinitrosoterephthalamide, azodicarbon Amide, benzenesulfonylhydrazide azodicarbonamide, p-toluenesulfonylhydrazine, azobisformamide, diethylazodicarboxylate, azobisisobutyronitrile, p-toluenesulfonylhydra , P, p'-oxybis (benzenesulfohydrazide), 3,3'-disulfohydrazide diphenylsulfone and other organic chemical foaming agents, water, carbon dioxide, nitrogen, air, sodium carbonate, potassium carbonate, magnesium carbonate, carbonic acid Non-halogen foaming agents such as inorganic foaming agents exemplified by calcium, barium carbonate, aluminum carbonate, zinc carbonate, ammonium carbonate, sodium bicarbonate, potassium bicarbonate, other carbonates, other bicarbonates, etc. It is preferable from the viewpoint of compatibility.
[0082]
For the production of the aromatic vinyl resin foam of the present invention, the amount of the foaming agent added may be appropriately changed according to the setting value of the expansion ratio. Usually, if the expansion ratio is about 20 to 40 times, the total amount of the foaming agent is preferably 2 to 20 parts by weight with respect to 100 parts by weight of the aromatic vinyl resin. When the expansion ratio may be extremely small, it is sufficient that the amount of the foaming agent added is less than 2 parts by weight. On the contrary, when the expansion ratio is as large as 100 times, it may be added in excess of 20 parts by weight, but in this case, care must be taken that voids and other defects occur in the foam due to the excessive amount of foaming agent. I must.
[0083]
In the present invention, inorganic compounds such as silica, talc, calcium silicate, wollastonite, kaolin, clay, mica, zinc oxide, titanium oxide, calcium carbonate, etc., as long as they do not inhibit the effects of the present invention, Light resistance of processing aids such as sodium stearate, magnesium stearate, barium stearate, liquid paraffin, olefin wax, stearylamide compound, phenolic antioxidant, phosphorus stabilizer, benzotriazoles, hindered amines Additives such as stabilizers, antistatic agents, colorants such as pigments, and the like can be included.
[0084]
Furthermore, in the present invention, for the purpose of imparting further excellent flame retardancy, other than the above-mentioned phosphorus flame retardant, nitrogen flame retardant, silicon flame retardant, metal hydroxide, sulfur flame retardant, antimony compound, boron Various flame retardants such as compounds can be used.
[0085]
Basically, the present invention originally aims to improve environmental compatibility by using a non-halogen flame retardant. Therefore, a non-halogen flame retardant such as a phosphorus atom-containing compound and / or a nitrogen atom-containing compound is used. When many are used, halogen flame retardants are not required, but when higher flame retardancy is required, the following halogen flame retardants are supplemented in addition to the non-halogen flame retardants described above. Can be used additionally.
[0086]
For example, halogen flame retardants include brominated products of aliphatic or alicyclic hydrocarbons such as hexabromocyclododecane, hexabromobenzene, ethylenebispentabromodiphenyl, decabromodiphenyl ether, octabromodiphenyl ether, 2,3-dibromo. Brominated aromatic compounds such as propylpentabromophenyl ether, tetrabromobisphenol A, tetrabromobisphenol A bis (2,3-dibromopropyl ether), tetrabromobisphenol A (2-bromoethyl ether), tetrabromobisphenol A Brominated bisphenols and their derivatives, such as diglycidyl ether, tetrabromobisphenol A diglycidyl ether and tribromophenol adduct, tetrabromobisphenol A Brominated bisphenol derivatives oligomers such as carbonate oligomer, tetrabromobisphenol A diglycidyl ether and brominated bisphenol adduct epoxy oligomer, tetrabromophthalerodiol, tetrabromophthalate ester, tetrabromophthalate disodium, poly (pentabromo Benzylpolyacrylate), pentabromophenol, bromophenoxyethanol, brominated phenol (novolak type), dibromocresyl glycidyl ether, brominated aromatic triazine, vinyl bromide, tribromophenol, dibromophenol, dibromometacresol, dibromoneopentyl glycol , Ethylenebistetrabromophthalimide, ethylenebisdibromonorbornanedicarboximide, Brominated aromatic compounds such as bis (2,4,6-tribromophenoxy) ethane, brominated acrylic resins, chlorinated paraffin, chlorinated naphthalene, perchloropentadecane, tetrachlorophthalic anhydride, chlorinated aromatic compounds , Chlorinated alicyclic compounds, and the like.
[0087]
Examples of the method for producing the aromatic vinyl resin foam of the present invention include, for example, an aromatic vinyl resin, a swellable layered silicate, a foaming agent and a phosphorus atom-containing compound, a nitrogen atom-containing compound, a polyhydric alcohol, if necessary. After melt-kneading additives such as other compounds using a kneader such as an extruder, extrusion foam molding, after obtaining a foamable composition by melt-kneading in the same manner, beads, if necessary, A method of giving a form such as a plate shape, a sheet shape, and heating again to obtain a foam, melt-kneading the aromatic vinyl resin, the swellable layered silicate, and the additive using a kneader such as an extruder The resin composition was obtained by melt-kneading the aromatic vinyl-based resin, the swellable layered silicate, and the additive using a kneader such as an extruder. After that, melt and knead again and start from the middle. A method of injecting an agent and performing extrusion foam molding, similarly, after melt-kneading to obtain a resin composition, if necessary, forms such as beads, plates, sheets, etc., and then impregnated with a foaming agent Then, the method of heating again and making it foam and obtaining a foam etc. is mentioned.
[0088]
Further, when producing an aromatic vinyl resin by polymerizing an aromatic vinyl compound and other compounds as required, a swellable layered silicate, a foaming agent and an additive are added, After that, if necessary, a form such as a bead shape, a plate shape, or a sheet shape is provided and heated again to foam to obtain a foam. Similarly, when producing an aromatic vinyl-based resin, a swellable layered silicic acid is used. After adding salt and additives to form a resin composition, if necessary, it is given a form such as beads, plates or sheets, then impregnated with a foaming agent, then heated again to foam and foam. The method of obtaining a body is mentioned. Of these, extrusion foam molding is recommended as the most preferred embodiment.
[0089]
From the viewpoint of dispersibility of the swellable layered silicate, an aromatic vinyl resin, a swellable layered silicate, and if necessary, a foaming agent and additives are melt-kneaded using a kneader such as an extruder (foamable) resin A method of obtaining a composition and then foaming, and a swellable layered silicate, and foaming if necessary, in producing an aromatic vinyl resin by polymerizing an aromatic vinyl compound and other compounds as required The method of adding an agent and an additive to obtain a (foamable) resin composition and then foaming is preferred.
[0090]
When melt-kneading using a kneader such as an extruder, as a method of adding the swellable layered silicate, a method of dry blending with an aromatic vinyl resin in advance, the swellable layered silicate from the middle of kneading A method of adding, a method of previously dispersing a swellable layered silicate in a dispersion medium such as water or an organic compound, and then blending it with an aromatic vinyl resin, a method of previously mixing a swellable layered silicate with water, an organic compound or the like Examples thereof include a method of dispersing in and adding from the middle of kneading. When the swellable layered silicate is previously dispersed in a dispersion medium such as water or an organic compound, it is preferable to remove the dispersion medium such as water or an organic compound during, at the end or after the kneading. This is not the case when a dispersion medium such as a compound is used as a foaming agent. Further, as a method of previously melt-kneading the aromatic vinyl resin and the swellable layered silicate, for example, Japanese Patent Application Laid-Open No. 9-2117012 has been proposed.
[0091]
As a method of adding a swellable layered silicate when producing an aromatic vinyl-based resin, a method of dispersing in an aromatic vinyl-based compound and / or other compounds as necessary, a swellable layered layer in advance A method in which a silicate is dispersed in a dispersion medium such as water or an organic compound and added before, during, or before polymerization, at any stage after the polymerization, and a swellable layered silicate is directly polymerized before, during, during or after polymerization Examples include a method of adding to an optional stage later. Furthermore, Japanese Patent Application Laid-Open No. 63-215775 proposes a method for adding a swellable layered silicate when producing an aromatic vinyl resin.
[0092]
【Example】
Next, although the aromatic vinyl-type resin foam of this invention and its manufacturing method are demonstrated in detail based on an Example, this invention is not limited only to this Example.
[0093]
The properties of the foams obtained by the methods shown in the following Examples and Comparative Examples are as follows: foam density, self-extinguishing properties, melt deformation / melting dripping status during combustion, and shape change status during high temperature heating according to the following methods: Examined.
I evaluated.
1) Foam density (kg / m^Three): Foam density is the following formula: Foam density (g / cm^Three) = Foam weight (g) / foam volume (cm^Three) Based on the unit (kg / m^Three).
2) Self-extinguishing property: A flammability test was carried out in accordance with the measurement method A in the flammability evaluation prescribed in JIS A9511 using a foam that had passed 14 days after production, and was determined according to the following criteria.
○: After releasing the flame, it extinguished immediately or burned slightly, but self-extinguished.
Δ: After releasing the flame, it burned to some extent but self-extinguished and the test piece remained.
X: After releasing the flame, the whole test piece burned without self-extinguishing.
[0094]
3) Melt deformation at the time of combustion, melt dripping status (shape retention): A flammability test was conducted in the same manner as 2), and the state after extinction was visually observed and judged according to the following criteria.
◯: No melt dripping, carbonization or foaming charcoal, almost maintained or deformed but no shrinkage observed.
Δ: No melt dripping, but carbonized or foamed carbon, but shrinkage was observed.
X: The test piece did not remain after melting and dropping.
[0095]
4) Shape change during high-temperature heating (shape retention characteristics): A test piece of 50 × 50 × 10 mm was cut out from the obtained foam and visually observed for 5 minutes in an electric furnace maintained at 500 ° C. And determined according to the following criteria.
A: The residue was slightly contracted or expanded, but maintained almost the original shape.
○: The residue contracted or expanded, but remained in a shape almost similar to the original shape.
Δ: Although the residue greatly contracted or expanded, the shape was maintained to some extent.
X: It melt | dissolved and the shape collapse | crumbled or there was no residue.
However, for example, when it is evaluated as Δ to ○, it indicates that the determination is intermediate between Δ and ○.
[0096]
5) Bottom spacing of swellable layered silicate (nm): using an X-ray generator (Rigaku Denki RU-200B), target CuKα line, Ni filter, voltage 40 kV, current 200 mA, scanning angle 2θ = The small angle X-ray diffraction peak angle value is measured under the measurement conditions of 0.2 to 16.0 ° and the step angle = 0.02 °, and the bottom surface interval is substituted for the small angle X-ray diffraction peak angle value in the Bragg equation. Calculated. However, when it is difficult to confirm the small-angle X-ray peak angle value, the swellable layered silicate swells and is dispersed until the peak angle value is difficult to confirm, or is sufficiently swollen and substantially molecular. It will be distributed.
[0097]
6) Dispersion state and particle thickness (nm) of swellable layered silicate: Ultrathin slices having a thickness of 50 to 100 μm were used. Using a transmission electron microscope (JEOL JEM-1200EX), the dispersion state of the swellable layered silicate was observed and photographed at an acceleration voltage of 80 kV and a magnification of 40,000 to 1,000,000 times. In the TEM photograph, a region where 100 or more dispersed particles were present was selected, and the number of particles and the particle thickness were measured using a ruler with a scale. The obtained results were applied to the following formula, and the ratio of particles having a particle thickness of 100 nm or less was determined.
Ratio of particles having a particle thickness of 100 nm or less = (number of particles having a swellable layered silicate particle size of 100 nm or less / total number of particles of a swellable layered silicate) × 100
[0098]
It evaluated by the method of an Example and a comparative example using the raw material shown below.
Aromatic vinyl resin
Resin 1: Polystyrene homopolymer: Estyrene G-17 manufactured by Nippon Steel Chemical Co., Ltd. (melt index = 3.1)
Resin 2: Styrene-methacrylic acid copolymer: A & M Styron G9001 manufactured by Styrene Co. (methacrylic acid copolymerization ratio is 8 wt%)
Resin 3: Styrene-maleic anhydride copolymer: Dilark D232 manufactured by ARCO Chemical Japan
Resin 4: Styrene-acrylonitrile copolymer: Toyo AS AS-61NT manufactured by Toyo Styrene Co., Ltd.
[0099]
Swellable layered silicate
Silicate 1: Montmorillonite: Kunimine Industries Co., Ltd. Kunipia F: Bottom spacing = 1.2 nm
Silicate 2: swellable fluoromica: Somasif ME-100 manufactured by Coop Chemical Co., Ltd .: bottom surface distance = 1.0 nm
Silicate 3: Organically treated montmorillonite: Cloisite 20A manufactured by Southern Clay Products (montmorillonite treated with dialkyl (C14-18) methylammonium ions: treatment amount is about 38% by weight): Bottom spacing = 2.4 nm
Silicate 4: Organic treatment-swelling fluorinated mica: MAE-120 manufactured by Coop Chemical Co., Ltd. (swelling fluorinated mica treated with dialkyl (C14-18) methylammonium ions: treatment amount is about 38% by weight): bottom surface Interval = 3.1nm
Silicate 5: Organized montmorillonite: produced in Production Example 1
Silicate 6: Organic treatment swelling fluorinated mica: produced in Production Example 2
[0100]
Phosphorus atom-containing compound
・ TPP: Triphenyl phosphate: TPP manufactured by Daihachi Chemical Industry Co., Ltd.
APP: Ammonium polyphosphate: Terrass C60 manufactured by Chisso Corporation
Nitrogen atom-containing compounds
MC: Melamine cyanurate: MC-440 manufactured by Nissan Chemical Industries, Ltd.
・ Melamine: Melamine: Reagent manufactured by Wako Pure Chemical Industries, Ltd.
Polyhydric alcohols
PER: Monopentaerythritol: Pentaerythritol manufactured by Mitsubishi Gas Chemical Co., Inc.
[0101]
Flame retardants
・ HBCD: Hexabromocyclododecane: ALBEMAR CORPORATION
Blowing agent
・ Isobutane: manufactured by Mitsui Chemicals, Inc.
・ Dimethyl ether: Mitsui Chemicals, Inc.
HCFC142b: 1-chloro 1,1-difluoroethane: manufactured by Daikin Industries
[0102]
Production Example 1
125 g of montmorillonite was added to 3500 g of ion-exchanged water, and the mixture was stirred and mixed at 5000 rpm for 5 minutes using a wet mill (manufactured by Nippon Seiki Co., Ltd.). Next, 35 g of phenyltrimethoxysilane (LS2750 manufactured by Shin-Etsu Silicone Co., Ltd.) was added, and the mixture was further stirred for 1 hour for treatment. The obtained silane compound-treated montmorillonite dispersion was dried at 120 ° C. for 24 hours to remove water, and then pulverized to obtain organically treated montmorillonite particles. The bottom distance of the obtained organically treated montmorillonite was 2.4 nm. The ratio of the weight after heating the organically treated montmorillonite at 650 ° C. for 2 hours to the weight before heating was 80% by weight, and it was confirmed that 80% by weight of montmorillonite was contained.
[0103]
Production Example 2
125 g of swellable fluorine mica was added to 3500 g of ion-exchanged water, and the mixture was stirred and mixed at 5000 rpm for 5 minutes using a wet mill (manufactured by Nippon Seiki Co., Ltd.). Subsequently, 13 g of bisphenol A copolymer polyethylene glycol (BPE-180 manufactured by Sanyo Chemical Co., Ltd.) was added, and the mixture was further stirred for 1 hour for treatment. The obtained silane compound-treated montmorillonite dispersion was dried at 120 ° C. for 24 hours to remove water, and then pulverized to obtain organically treated swellable fluorinated mica particles. The bottom distance of the obtained organically treated swelling fluorinated mica was 1.9 nm. Further, the ratio of the weight after heating the organically treated swelling fluorinated mica at 650 ° C. for 2 hours to the weight before heating is 90% by weight, and 90% by weight of the swellable fluorinated mica is contained. confirmed.
[0104]
Example 1
As an aromatic vinyl resin, silicate 1 (montmorillonite) 30 parts by weight, APP (ammonium polyphosphate) 50 parts by weight, talc 0.3 parts by weight, stearic acid with respect to 100 parts by weight of resin 1 (polystyrene homopolymer) After 0.2 parts by weight of barium was dry blended, it was melt kneaded using a 30 mmφ co-rotating twin screw extruder (L / D = 30) to obtain a resin composition.
[0105]
The obtained resin composition was fed at a rate of about 40 kg / hr to an extruder in which those having a diameter of 65 mm and a diameter of 90 mm were vertically connected. It was supplied to an extruder having a diameter of 65 mm, heated to 200 ° C., melted and kneaded, the resin temperature was cooled to 120 ° C. with an extruder having a diameter of 90 mm connected thereto, and provided at the tip of the extruder having a diameter of 90 mm. Extruded into the atmosphere from a die having a rectangular cross-section discharge port with a thickness direction of 2 mm and a width direction of 50 mm, and a rectangular parallelepiped extruded foam was obtained. At this time, as a foaming agent, a foaming agent composed of 4 parts of isobutane with respect to 100 parts by weight of the resin and 2 parts of dimethyl ether, respectively, from a separate line, near the tip of the 65 mm diameter extruder (90 mm diameter). The resin was press-fitted into the resin from the end connected to the end opposite to the end die of the extruder. The properties of the obtained foam are shown in Table 1.
[0106]
(Examples 2 to 17)
Using the aromatic vinyl-based resin, the swellable layered silicate, the phosphorus atom-containing compound, the nitrogen atom-containing compound, the polyhydric alcohol, and the foaming agent described above, the composition shown in Table 1 and Example 1 Similarly, a resin composition and a foam were obtained. The properties of the obtained foam are shown in Table 1.
(Comparative Examples 1 and 2)
With the composition shown in Table 1, a resin composition and a foam were obtained in the same manner as in Example 1. The properties of the obtained foam are shown in Table 1.
[0107]
As can be seen by comparing Examples 1 to 17 and Comparative Examples 1 and 2, the aromatic vinyl resin foam containing the swellable layered silicate of the present invention is excellent in shape retention when heated at high temperature. You can see that
[0108]
As can be seen by comparing Examples 1 and 3 with Examples 2, 4, 5, 7 and 9, by combining a phosphorus atom-containing compound, a nitrogen atom-containing compound and a polyhydric alcohol, self-extinguishing properties, during combustion It can be seen that the shape-retaining property and the shape-retaining property during heating can be improved, and in particular, when the three types are used in combination, the effect is exhibited even when the total weight part is relatively small.
[0109]
As can be seen by comparing Examples 6, 7 and 9 with Examples 13 to 16, the use of an aromatic vinyl resin having a polar group improves shape retention during heating compared to polystyrene homopolymer. I know that As a result of observing the dispersion state of the swellable layered silicate in Examples 6 and 13, in Example 6, the ratio of particles having a particle thickness of 100 nm or less was 1, whereas in Example 13, from 15 and Example 6 It was a high value.
[0110]
As can be seen by comparing Example 7 and Example 17, it can be seen that the use of ammonium polyphosphate containing a phosphorus atom and a nitrogen atom as the phosphorus atom-containing compound is superior in shape retention during heating.
(Examples 21 to 29)
Using the aromatic vinyl-based resin, the swellable layered silicate, the phosphorus atom-containing compound, the nitrogen atom-containing compound, the polyhydric alcohol, and the foaming agent described above, the composition shown in Table 1 and Example 1 Similarly, a resin composition and a foam were obtained. The properties of the obtained foam are shown in Table 2.
[0111]
As can be seen by comparing Examples 6, 7 and 9 with Examples 18 to 20, when the organically treated swelling layered silicate was used, the untreated swelling layered silicate was used. It can be seen that the shape retention during heating is improved. However, in Example 18, the actual content of montmorillonite is 5 parts by weight with respect to 100 parts by weight of the aromatic vinyl resin, and in Example 19, the actual content of swellable fluoromica is 100 parts by weight of the aromatic vinyl resin. On the other hand, it is 10 parts by weight, and in Example 20, it is 30 parts by weight. Furthermore, while the bottom gaps of montmorillonite or swellable fluorine mica in Examples 6, 7, and 9 were 1.2 nm, 1.2 nm, and 1.0 nm, respectively, in Examples 18, 19, and 20, respectively. 2.3 nm, 3.0 nm, and 3.0 nm. In Examples 6, 7, and 9, the proportion of particles having a particle thickness of 100 nm or less was 1, whereas in Examples 18, 19, and 20, they were 31, 25, and 27, respectively.
[0112]
As can be seen in comparison with Examples 18 and 19 and Examples 21 and 22, the combination of the aromatic vinyl-based resin having a polar group and the organically treated swellable layered silicate has a shape retention property during heating. Can be seen to improve. In Examples 21 and 22, as a result of measuring the bottom surface spacing of montmorillonite and swellable fluorine mica, X-ray diffraction peak angle values indicating the bottom surface spacing of 2.4 nm and 3.1 nm were observed only slightly. As a result of observing the dispersed state, the ratio of particles having a particle thickness of 100 nm or less was 81 and 90, respectively. Furthermore, most of the particles having a particle thickness of 100 nm or less had a unit layer thickness of montmorillonite or swellable fluorine mica or a thickness corresponding to the case where about 2 to 20 layers were stacked.
[0113]
In Examples 23 to 25 and 27 to 29, the swellable layered silicate was dispersed in the same manner as in Examples 21 and 22. In the case where silicate 3 was used slightly, 2.4 nm and silicate 4 were used. In 3.1 nm and silicate 5, an X-ray diffraction peak angle value indicating a bottom surface interval of 2.4 nm was observed, and the ratio of particles having a particle thickness of 100 nm or less was 75 or more. In Example 26, an X-ray diffraction peak angle value with a bottom surface spacing of 1.9 nm was observed, and the ratio of particles having a particle thickness of 100 nm or less was 32.
[0114]
(Example 30)
Resin 1 (polystyrene homopolymer) is used as an aromatic vinyl resin, 100 parts by weight of resin 1 (polystyrene homopolymer) is charged into a kneader, and 10% by weight of silicate 1 (montmorillonite) is dispersed in 100% by weight of water. The solution was kneaded while gradually adding, and finally 50 parts by weight of the solution was added. The obtained resin composition was pulverized and then melt-kneaded using a 30 mmφ co-rotating twin screw extruder (L / D = 30). Next, after drying the obtained resin composition, 100 parts by weight of resin 1 is 25 parts by weight of APP (ammonium polyphosphate), 10 parts by weight of MC (melamine cyanurate), and PER (monopentaerythritol). After dry blending to 25 parts by weight, 0.3 parts by weight of talc, and 0.2 parts by weight of barium stearate, it was melt-kneaded again using a 30 mmφ co-rotating twin screw extruder (L / D = 30). A resin composition was obtained.
[0115]
The obtained resin composition was fed at a rate of about 40 kg / hr to an extruder in which those having a diameter of 65 mm and a diameter of 90 mm were vertically connected. It was supplied to an extruder having a diameter of 65 mm, heated to 200 ° C., melted and kneaded, the resin temperature was cooled to 120 ° C. with an extruder having a diameter of 90 mm connected thereto, and provided at the tip of the extruder having a diameter of 90 mm. Extruded into the atmosphere from a die having a rectangular cross-section discharge port with a thickness direction of 2 mm and a width direction of 50 mm, and a rectangular parallelepiped extruded foam was obtained. At this time, as a foaming agent, a foaming agent consisting of 4 parts of isobutane with respect to 1100 parts by weight of the resin and 2 parts of dimethyl ether, respectively, from a separate line, near the tip of the 65 mm diameter extruder (an extruder having a 90 mm diameter) From the end of the die opposite to the end die) and pressed into the resin. The properties of the obtained foam are shown in Table 2.
[0116]
As a result of measuring the bottom face spacing, an X-ray diffraction peak angle value showing 1.2 nm was observed, and the ratio of particles having a particle thickness of 100 nm or less was 50.
[0117]
Compared to Example 6, it can be seen that the shape retention during heating is improved.
(Example 31)
As an aromatic vinyl-based resin, 16 parts by weight of silicate 4 (swelling fluorinated mica subjected to organic treatment) is dry blended with 100 parts by weight of resin 1 (polystyrene homopolymer), and then 30 mmφ co-rotating twin screw extruder (L / D = 30) was used for melt kneading. After drying the obtained resin composition, it was melt-kneaded again using a 30 mmφ co-rotating twin screw extruder (L / D = 30), and this was repeated twice more. Next, 25 parts by weight of APP (ammonium polyphosphate), 10 parts by weight of MC (melamine cyanurate), 25 parts by weight of PER (monopentaerythritol), 0.3 parts by weight of talc, with respect to 100 parts by weight of resin 1 After dry blending to 0.2 parts by weight of barium stearate, it was melt kneaded again using a 30 mmφ co-rotating twin screw extruder (L / D = 30) to obtain a resin composition.
[0118]
The obtained resin composition was fed at a rate of about 40 kg / hr to an extruder in which those having a diameter of 65 mm and a diameter of 90 mm were vertically connected. It was supplied to an extruder having a diameter of 65 mm, heated to 200 ° C., melted and kneaded, the resin temperature was cooled to 120 ° C. with an extruder having a diameter of 90 mm connected thereto, and provided at the tip of the extruder having a diameter of 90 mm. Extruded into the atmosphere from a die having a rectangular cross-section discharge port with a thickness direction of 2 mm and a width direction of 50 mm, and a rectangular parallelepiped extruded foam was obtained. At this time, as a foaming agent, a foaming agent consisting of 4 parts of isobutane with respect to 1100 parts by weight of the resin and 2 parts of dimethyl ether, respectively, from a separate line, near the tip of the 65 mm diameter extruder (an extruder having a 90 mm diameter) From the end of the die opposite to the end die) and pressed into the resin. The properties of the obtained foam are shown in Table 2.
[0119]
As a result of measuring the bottom face spacing, an X-ray diffraction peak angle value indicating 3.0 nm was observed, and the ratio of particles having a particle thickness of 100 nm or less was 40.
[0120]
It can be seen that the shape retention during heating is improved as compared with Example 19.
(Example 32)
An aromatic vinyl-based resin foam was obtained in the same manner as in Example 31 except that the resin 1 was changed to the resin 2 (styrene-methacrylic acid copolymer).
[0121]
As a result of measuring the bottom surface spacing, no X-ray diffraction peak angle value was observed. Further, the ratio of particles having a particle thickness of 100 nm or less was 100, and it was observed that the swellable fluorine mica was dispersed substantially in a molecular form.
[0122]
It can be seen that the shape retention during heating is improved compared to Example 22.
[0123]
[Table 1]

[0124]
[Table 2]

[0125]
【The invention's effect】
According to the present invention, a foam made of an aromatic vinyl resin that is a thermoplastic resin excellent in environmental compatibility, and a method for producing the same, which are melted and dropped when in contact with a flame, and exposed to a high temperature As a result, the aromatic vinyl-based resin foam excellent in flame retardancy can be obtained.

Claims (8)

Selected from the group consisting of 0.1 to 100 parts by weight of a swellable layered silicate, 100 parts by weight of an aromatic vinyl resin, a compound containing a phosphorus atom-containing compound and / or a triazine skeleton, a diazo compound, and a tetrazole compound An aromatic vinyl-based resin foam comprising 1 to 200 parts by weight of at least one nitrogen atom-containing compound and 1 to 200 parts by weight of a polyhydric alcohol . Aromatic vinyl resin foam of claim 1 wherein the basal spacing is characterized by containing the above swellable layered silicate 1.6 nm. The aromatic vinyl resin foam according to claim 1 or 2, comprising a swellable layered silicate having a particle thickness satisfying the following formula.
(The number of particles having a swellable layered silicate particle thickness of 100 nm or less / the total number of particles of the swellable layered silicate) × 100 ≧ 20 The aromatic vinyl resin foam according to any one of claims 1 to 3 , wherein an X-ray diffraction peak angle value derived from a (001) plane of the swellable layered silicate in the foam is not detected. body. The aromatic vinyl resin foam according to any one of claims 1 to 4, wherein a part or all of the aromatic vinyl resin is a resin obtained by polymerizing a compound unit containing a polar group. Swellable layered silicate organic onium salts, organic compounds having a polar group, any one of claims 1 to 5, wherein, characterized in that those treated with one or more organic compounds selected from the silane compound 2. Aromatic vinyl resin foam according to item 1. The aromatic vinyl resin foam according to any one of claims 1 to 6, wherein the phosphorus atom-containing compound is a compound containing a phosphorus atom and a nitrogen atom. The method for producing an aromatic vinyl resin foam according to any one of claims 1 to 7 , wherein the aromatic vinyl resin is foam-molded by containing a non-halogen foaming agent.