JP3654456B2 - Process for gas phase polymerization of olefins - Google Patents

Description

【００２８】
上記ような流動層高さの測定方法では、流動層内の流動化嵩密度（ΔＰ₁ −ΔＰ₂ ）／（ｈ₂ −ｈ₁ ）が考慮されているため、流動層を形成する粉体の密度などが変化しても、流動層高さを正確に決定することができる。
【００２９】
固体状触媒を上記のような高さ供給すると、循環ガス中に同伴される微粒子ポリマー、触媒粒子などの量が減少し、循環ガスやガス分散板が閉塞することが少なくなる。
【００３０】
本発明では、前記固体状触媒を反応器の内壁から０．０２Ｄ〜０．５Ｄの位置であり、かつ反応器のガス分散板から０．１Ｈ〜０．９Ｈの高さ、好ましくは反応器の内壁から０．０２Ｄ〜０．４Ｄの位置であり、かつ反応器のガス分散板から０．２Ｈ〜０．５Ｈの高さ、より好ましくは反応器の内壁から０．０２Ｄ〜０．４Ｄの位置であり、かつ反応器のガス分散板から０．２Ｈ〜０．５Ｈの高さ、特に好ましくは反応器の内壁から０．１Ｄ〜０．３Ｄの位置であり、かつ反応器のガス分散板から０．２Ｈ〜０．４Ｈの高さに供給することが望ましい。
【００３１】
固体状触媒を上記のような位置および高さに供給すると、シーティングやポリマー塊の発生が生じ難くなり、かつ循環ガスやガス分散板が閉塞することが少なくなる。
【００３２】
上記のような位置に触媒を供給するには、触媒フィードノズル２先端の位置（ｌ）を反応器の内壁から０．０２Ｄ〜０．５Ｄ、好ましくは０．０２Ｄ〜０．４Ｄ、より好ましくは０．０５Ｄ〜０．３５Ｄ、特に好ましくは０．１Ｄ〜０．３Ｄの範囲とし、触媒フィードノズル２先端の高さ（ｈ）をガス分散板４から０．１Ｈ〜０．９Ｈ、好ましくは０．２Ｈ〜０．５Ｈ、より好ましくは０．２Ｈ〜０．４Ｈの範囲とすればよい。
【００３３】
触媒フィードノズル２の向きは、水平又は水平から下向きが好ましく、水平から下向き０〜５０゜の角度で設置されていることがより好ましい。また、触媒フィードノズルの数は、特に限定されないが２〜４本であることが望ましい。
【００３４】
本発明では、固体状触媒を触媒フィードノズル２から上記のような特定の位置に供給するときに、随伴ガスとしてオレフィンガス又はオレフィンガスを含有するガスを用いる。この際の、触媒フィードノズル２の供給口での随伴ガスの流速は、反応器の流動層ガス空塔速度（流動用循環ガス線速）の２〜１００倍、好ましくは５〜７０倍、より好ましくは１０〜５０倍である。なお反応器の流動層ガス空塔速度は、通常０．２〜１．０ｍ／秒、好ましくは０．４〜０．８ｍ／秒である。
【００３５】
オレフィンガスとしては、通常重合に用いられる１種または２種以上のオレフィンが用いられる。
オレフィンガスを含有するガスとしては、重合に用いられる１種または２種以上のオレフィンを含む不活性ガスが挙げられ、不活性ガスとしては、窒素ガス、アルゴンガスなどが挙げられる。このようなオレフィンガスを含有するガスにおいては、オレフィンガスは１０〜１００モル％、好ましくは２０〜９０モル％の割合で含有されていることが好ましい。
【００３６】
触媒フィードノズルの供給口における随伴ガスの流速が上記範囲より遅いと、固体状触媒粒子が供給配管内で沈積して詰ったり、流動層のポリマー粒子が触媒フィードノズルに逆流したり、触媒フィードノズル近傍で塊状ポリマーを生成することがある。また触媒フィードノズルの供給口における随伴ガスの流速が上記範囲より速いと、固体状触媒粒子が供給配管内で破砕したり、固体状触媒粒子が反応器内の流動層を突き抜けて反対側の壁面に当たり塊状ポリマーが生成したり、固体状触媒粒子が流動層の粉面上部よりガス層に吹き抜けたりすることがある。
【００３７】
固体状触媒を供給する際の随伴ガスとしてオレフィンガス又はオレフィンガスを含有するガスを用いると、反応器内の不活性ガスを反応器外に放出する必要がなく、随伴ガスとして不活性ガスを用いる場合に比べて経済的に有利である。
【００３８】
上記のように固体状触媒を反応器の特定の位置に供給するとともに、固体触媒を反応器に供給する際の随伴ガスとして、オレフィンガスまたはオレフィンガスと不活性ガスとの混合ガスを用いると、流動床内におけるポリマー塊、シート状物などの発生を低下させることができ、かつ配管、ガス分散板などの閉塞を減少させることができ、しかも経済的に有利である。
【００３９】
このような本発明に係るオレフィンの気相重合方法で用いられる固体状触媒としては、マグネシウム、チタン、ハロゲンを必須成分とするチタン系固体状触媒、第４族遷移金属のメタロセン化合物と有機アルミニウム成分と微粒子状担体からなるメタロセン系固体状触媒などが挙げられ、特に後述するようなメタロセン系固体状触媒を用いることが好ましい。
【００４０】
本発明で好ましく用いられるメタロセン系固体状触媒は、重合活性が５００００ｇ／ｍ
ｍｏｌ・遷移金属・時間以上の高活性触媒であることが好ましく、具体的には、たとえば（Ａ）シクロペンタジエニル骨格を有する配位子を含む第４族遷移金属化合物と、
（Ｂ）有機アルミニウムオキシ化合物と、
（Ｃ）微粒子状担体とから
形成された固体状のメタロセン系触媒を例示することができる。
【００４１】
メタロセン系固体状触媒を形成する（Ａ）シクロペンタジエニル骨格を有する配位子を含む第４族遷移金属化合物としては、下記一般式（Ｉ）で表される化合物を例示することができる。
【００４２】
ＭＬ_X … （Ｉ）
式中、Ｍは第４族の遷移金属原子から選ばれる１種の遷移金属原子を示し、好ましくはジルコニウム、チタンまたはハフニウムである。
【００４３】
ｘは、遷移金属の原子価であり、Ｌの個数を示す。
Ｌは、遷移金属に配位する配位子または基を示し、少なくとも１個のＬは、シクロペンタジエニル骨格を有する配位子であり、該シクロペンタジエニル骨格を有する配位子以外のＬは、炭素原子数が１〜１２の炭化水素基、アルコシキ基、アリーロキシ基、トリアルキルシリル基、ＳＯ₃Ｒ（ただし、Ｒはハロゲンなどの置換基を有していてもよい炭素原子数が１〜８の炭化水素基）、ハロゲン原子、および水素原子からなる群より選ばれる１種の基または原子である。
【００４４】
シクロペンタジエニル骨格を有する配位子としては、たとえばシクロペンタジエニル基、アルキル置換シクロペンタジエニル基、インデニル基、アルキル置換インデニル基、4,5,6,7-テトラヒドロインデニル基、フルオレニル基などを例示することができる。これらの基はハロゲン原子、トリアルキルシリル基などが置換していてもよい。
【００４５】
上記一般式（Ｉ）で表される化合物が、シクロペンタジエニル骨格を有する配位子を２個以上含む場合、そのうち２個のシクロペンタジエニル骨格を有する配位子同士は、アルキレン基、置換アルキレン基、シリレン基、置換シリレン基などを介して結合されていてもよい。
【００４６】
第４族遷移金属化合物（Ａ）としては、シクロペンタジエニル骨格を有する配位子を２個有する化合物が好ましく用いられ、Ｍがジルコニウムでありシクロペンタジエニル骨格を有する配位子を２個有する化合物がより好ましく用いられる。
【００４７】
メタロセン系固体状触媒を形成する有機アルミニウムオキシ化合物（Ｂ）としては、具体的には、従来公知のアルミノキサンおよび特開平２-７８６８７号公報に例示されているようなベンゼン不溶性の有機アルミニウムオキシ化合物が挙げられる。
【００４８】
メタロセン系固体状触媒を形成する微粒子状担体（Ｃ）として具体的には、ＳｉＯ₂ 、Ａｌ₂Ｏ₃ 、ＭｇＯ、ＺｒＯ₂ 、ＴｉＯ₂ 、Ｂ₂Ｏ₃ 、ＣａＯ、ＺｎＯ、ＢａＯ、ＴｈＯ₂ など、またはこれらを含む混合物、たとえばＳｉＯ₂-ＭｇＯ、ＳｉＯ₂-Ａｌ₂Ｏ₃ 、ＳｉＯ₂-ＴｉＯ₂ 、ＳｉＯ₂-Ｖ₂Ｏ₅ 、ＳｉＯ₂-Ｃｒ₂Ｏ₃ 、ＳｉＯ₂-ＴｉＯ₂-ＭｇＯなどの無機担体、ポリエチレン、ポリプロピレン、ポリ 1-ブテン、ポリ 4-メチル-1-ペンテン、スチレン-ジビニルベンゼン共重合体などの有機担体を挙げることができる。
【００４９】
このような微粒子状担体（Ｃ）は、平均粒径が、１〜３００μｍ、好ましくは１０〜２００μｍの範囲にあることが望ましい。
本発明で好ましく用いられるメタロセン系固体状触媒は、上記第４族遷移金属化合物（Ａ）、有機アルミニウムオキシ化合物（Ｂ）および微粒子状担体（Ｃ）から形成されるが、必要に応じて有機アルミニウム化合物（Ｄ）を含んでいてもよい。
【００５０】
このような有機アルミニウム化合物（Ｄ）としては、たとえば下記一般式（II）で表される有機アルミニウム化合物を例示することができる。
Ｒ^a _nＡｌＸ_3-n … （II）
（式中、Ｒ^a は炭素数１〜１２の炭化水素基であり、Ｘはハロゲン原子または水素原子であり、ｎは１〜３である。）
このような有機アルミニウム化合物（Ｄ）としては、具体的にはトリメチルアルミニウム、トリエチルアルミニウム、トリイソプロピルアルミニウム、トリイソブチルアルミニウムなどが挙げられる。
【００５１】
また有機アルミニウム化合物（Ｄ）として、下記一般式（III）で表される化合物を用いることもできる。
Ｒ^a _n ＡｌＹ_3-n … （III）
（式中、Ｒ^a は上記と同様であり、Ｙは−ＯＲ^b 基、−ＯＳｉＲ^c ₃ 基、−ＯＡｌＲ^d ₂ 基、−ＮＲ^e ₂ 基、−ＳｉＲ^f ₃ 基または−Ｎ（Ｒ^g ）ＡｌＲ^h ₂ 基であり、ｎは１〜２であり、Ｒ^b 、Ｒ^c 、Ｒ^d およびＲ^h はメチル基、エチル基、イソプロピル基、イソブチル基、シクロヘキシル基、フェニル基などであり、Ｒ^e は水素原子、メチル基、エチル基、イソプロピル基、フェニル基、トリメチルシリル基などであり、Ｒ^f およびＲ^g はメチル基、エチル基などである。）
メタロセン系固体状触媒は、上記のような（Ａ）遷移金属化合物、（Ｂ）有機アルミニウムオキシ化合物、（Ｃ）粒子状担体、および必要に応じて（Ｄ）有機アルミニウム化合物とから従来公知の方法により形成される。
【００５２】
メタロセン系固体状触媒を調製するに際して、（Ａ）遷移金属化合物（遷移金属原子換算）は、（Ｃ）粒子状担体１ｇ当り、通常０．００１〜１．０ミリモル、好ましくは０．０１〜０．５ミリモルの量で、（Ｂ）有機アルミニウムオキシ化合物は、通常０．１〜１００ミリモル、好ましくは０．５〜２０ミリモルの量で、（Ｄ）有機アルミニウム化合物は通常０．００１〜１０００ミリモル、好ましくは２〜５００ミリモルの量で用いられる。
【００５３】
このようなメタロセン系固体状触媒粒子は、粒径が１〜３００μｍ、好ましくは１０〜１００μｍの範囲にあることが望ましい。
またメタロセン系固体状触媒は、上記のような触媒成分とともに、必要に応じて電子供与体、反応助剤などのオレフィン重合に有用な他の成分を含んでいてもよい。
【００５４】
なおメタロセン系固体状触媒は、オレフィンが予備重合されていてもよい。
このようなメタロセン系固体状触媒は、オレフィンを優れた重合活性で（共）重合させることができる。
【００５５】
一般的に高活性チグラーナッタ型、高活性メタロセン型触媒は、水、アルコール、酸素、二酸化炭素、一酸化炭素等の不純物によって活性が阻害され易く、このような不純物は種パウダー、モノマー、イナートガス等に含まれることがある。この場合、活性阻害防止剤として有機アルミニウム化合物、好ましくはトリアルキルアルミニウムを添加することにより活性阻害物質による触媒活性の低減を防止することができる。しかし、有機アルニミウムを添加すると樹脂中のアッシュ分が増加し、製品品質の低下の原因となることがあり、また有機アルミニウム化合物も微弱ながら触媒に対して活性阻害効果があることも知られている。このため、活性阻害物質が含まれている間は有機アルミニウム化合物を添加することは有意義であるが活性阻害物質が含まれない系では有機アルミニウム化合物を用いないことが好ましい。従って、気相重合を行うに際しては重合系に活性阻害物質が含まれている場合に限り有機アルミニウム化合物（Ｄ）を添加することが望ましい。
【００５６】
ここで、本発明の方法により重合し得るオレフィンとしては、炭素数２〜１８のα−オレフィンが好ましく挙げられ、たとえば、エチレン、プロピレン、1-ブテン、1ーペンテン、1-ヘキセン、4-メチル-1-ペンテン、3-メチル-1-ペンテン、1-ヘプテン、1-オクテン、1-ノネン、1-デセン、1-ウンデセン、1-ドデセン、1-テトラデセン、1-ヘキサデセン、1-オクタデセンなどが挙げられる。
【００５７】
さらに、シクロペンテン、シクロヘプテン、ノルボルネン、5-メチル-2-ノルボルネン、テトラシクロドデセン、2-メチル1,4,5,8-ジメタノ-1,2,3,4,4a,5,8,8a-オクタヒドロナフタレン、スチレン、ビニルシクロヘキサンなども挙げられる。
【００５８】
本発明においては、これらのオレフィンを重合あるいは共重合させる。
またオレフィンとともに、ブタジエン、イソプレン、1,4-ヘキサジエン、ジシクロペンタジエン、5-エチリデン-2-ノルボルネンなどのポリエン類を共重合させることもできる。
【００５９】
上記のような固体状触媒を用いて本発明の方法によりオレフィンを重合するに際して、固体状触媒は、重合容積１リットル当り該固体状触媒に担持されている第４族遷移金属化合物（Ａ）中の遷移金属原子に換算して、通常０．００００１〜１．０ミリモル／時間、好ましくは０．０００１〜０．１ミリモル／時間の割合で用いられることが望ましい。
【００６０】
重合温度は、２０〜１３０℃、好ましくは５０〜１２０℃、より好ましくは６０〜１００℃の範囲であることが望ましく、重合圧力は、重合されるオレフィンおよび流動床（反応系）の流動状態によっても異なるが、通常１〜1 ００ｋｇ／ｃｍ² 、好ましくは２〜４０ｋｇ／ｃｍ² の範囲であることが望ましい。
【００６１】
また重合に際しては、オレフィン重合条件下においては重合しない非重合性炭化水素あるいは窒素などの重合不活性ガスを共存させることができる。
このような非重合性炭化水素としては、易揮発性の低沸点非重合性炭化水素を用いてもよい。この低沸点非重合性炭化水素は低温において凝縮しやすく、たとえば循環ライン６に設けられた凝縮器（図示せず）などにおいて水などの一般的な冷媒によって容易に液化しうるものであることが好ましい。このような低沸点非重合性炭化水素としては、具体的に、飽和炭化水素を挙げることができ、さらに具体的には、たとえば、プロパン、n-ブタン、i-ブタン、n-ペンタン、i-ペンタン、シクロペンタン、n-ヘキサン、2-メチルペンタン、シクロヘキサンを挙げることができる。これらは、単独でまたは組み合わせて用いることができる。
【００６２】
【発明の効果】
本発明に係るオレフィンの気相重合方法は、シーティングやポリマー塊の発生がなく、循環ガスやガス分散板を閉塞させることがないので、長期間にわたって安定的にオレフィンを重合することができる。また、随伴ガスとして不活性ガスを用いる場合に比べて経済的に有利である。さらに、本発明の方法により得られた重合体は、流動性に優れている。
【００６３】
【実施例】
以下、実施例に基づいて本発明をさらに具体的に説明するが、本発明はこれら実施例に限定されるものではない。
【００６４】
【実施例１】
［触媒の調製］
２５０℃で１０時間乾燥したシリカ（ＳｉＯ₂ ）１０ｋｇを、１５４リットルのトルエンに懸濁した後、０℃まで冷却した。この懸濁液に、メチルアミノキサンのトルエン溶液（Ａｌ＝１．３３モル／リットル）８２．０リットルを１時間かけて滴下した。この際、系内の温度を０℃に保った。引続き０℃で３０分間反応させ、次いで１．５時間かけて９５℃まで昇温し、その温度で２０時間反応させた。その後６０℃まで降温し、上澄液をデカンテーションにより除去した。このようにして得られた固体成分をトルエンで２回洗浄した後、トルエン１００リットルで再懸濁した。
【００６５】
このようにして得られた懸濁液に、ビス（メチルブチルシクロペンタジエニル）ジルコニウムジクロリドのトルエン溶液（Ｚｒ＝２７．０ミリモル／リットル）２４．０リットルを８０℃で３０分間かけて滴下し、さらに８０℃で２時間反応させた。その後、上澄液を除去し、ヘキサンで２回洗浄することにより、シリカ１ｇ当り５．１ｍｇのジルコニウムと１８９ｍｇのアルミニウムとを含有する固体状触媒を得た。得られた固体状触媒は、ほぼ球形の形状の良い触媒であった。
【００６６】
［気相重合］
図１に示すような反応系５の直径が１００ｃｍφ、高さが１８０ｃｍ、流動層容積１４００リットル、減速域３ａの最大直径１４０ｃｍφからなる流動床反応器３（連続式重合装置）を用い、エチレンと1-ヘキセンとを連続的に気相共重合させた。
【００６７】
流動床反応器３の流動床５内に、上記のようにして得られた固体状触媒を、Ｚｒ原子に換算して０．４６ミリモル／時間の量でｌ＝０．１０Ｄ、ｈ＝０．４３Ｈの位置にエチレン１００％の随伴ガスとともに供給し、エチレンを随伴ガスとの合計量で７５ｋｇ／時間の割合となるように、1-ヘキセンを８ｋｇ／時間および水素を７５リットル／時間の割合でライン９から連続的に供給した。
【００６８】
気相重合器内の重合条件は、圧力２０ｋｇ／ｃｍ²-G 、重合温度８５℃、滞留時間４．２時間、反応器内の流動層ガス空塔速度を０．７ｍ／秒、触媒フィードノズル先端での随伴ガス流速を１０ｍ／秒に保持した。
【００６９】
気相重合器内のガス組成は、エチレン７３．０モル％、1-ヘキセン１．６モル％、水素３３０ｐｐｍで残りは窒素であった。
生成したポリエチレン（ＬＬＤＰＥ）を、７０ｋｇ／時間の量でライン１１から連続的に抜き出した。
【００７０】
上記のようにして得られたポリエチレンは、メルトフローレート（ＭＦＲ）が４．０ｇ／10分であり、密度が０．９２０ｇ／ｃｍ³ である極めて流動性のよい粒子であった。
【００７１】
上記のような条件下で、１週間の連続運転を実施したが、気相重合器は安定しており、反応器からの重合体粒子の排出もスムーズであり、極めて安定した運転が可能であった。結果を表１に示す。
【００７２】
【実施例２】
実施例１において、触媒の供給位置をｌ＝０．２５Ｄ、ｈ＝０．１４Ｈとし、触媒フィードノズル先端での随伴ガス流速を３ｍ／秒とした以外は実施例１と同様にしてエチレンと1-ヘキセンとを共重合した。
【００７３】
上記のような条件下で、１週間の連続運転を実施したが、気相重合器は安定しており、反応器からの重合体粒子の排出もスムーズであり、極めて安定した運転が可能であった。結果を表１に示す。
【００７４】
【実施例３】
実施例１において、触媒の供給位置をｌ＝０．３５Ｄ、ｈ＝０．７９Ｈとした以外は実施例１と同様にしてエチレンと1-ヘキセンとを共重合した。
【００７５】
上記のような条件下で、１週間の連続運転を実施したが、気相重合器は安定しており、反応器からの重合体粒子の排出もスムーズであり、極めて安定した運転が可能であった。結果を表１に示す。
【００７６】
【実施例４】
実施例１において、触媒の供給位置をｌ＝０．０１Ｄ、ｈ＝０．０５Ｈとし、触媒フィードノズル先端での随伴ガス流速を１５ｍ／秒とした以外は実施例１と同様にしてエチレンと1-ヘキセンとを共重合した。
【００７７】
上記のような条件下で、１週間の連続運転を実施したが、気相重合器は安定しており、反応器からの重合体粒子の排出もスムーズであり、極めて安定した運転が可能であった。結果を表１に示す。
【００７８】
【実施例５】
実施例１において、触媒の供給位置をｌ＝０．０１Ｄ、ｈ＝０．０５Ｈとした以外は実施例１と同様にしてエチレンと1-ヘキセンとを共重合した。
【００７９】
上記のような条件下で、１週間の連続運転を実施したが、気相重合器は安定しており、反応器からの重合体粒子の排出もスムーズであり、極めて安定した運転が可能であった。結果を表１に示す。
【００８０】
【実施例６】
実施例１において、触媒の供給位置をｌ＝０．２５Ｄ、ｈ＝０．３Ｈとし、触媒フィードノズル先端での随伴ガス流速を５ｍ／秒とし、反応器内の流動層ガス空塔速度を０．５５ｍ／秒とした以外は実施例１と同様にしてエチレンと1-ヘキセンとを共重合した。
【００８１】
上記のような条件下で、１週間の連続運転を実施したが、気相重合器は安定しており、反応器からの重合体粒子の排出もスムーズであり、極めて安定した運転が可能であった。結果を表１に示す。
【００８２】
【実施例７】
実施例１において、触媒の供給位置をｌ＝０．２５Ｄ、ｈ＝０．３Ｈとし、触媒フィードノズル先端での随伴ガス流速を４０ｍ／秒とし、反応器内の流動層ガス空塔速度を０．５５ｍ／秒とした以外は実施例１と同様にしてエチレンと1-ヘキセンとを共重合した。
【００８３】
上記のような条件下で、１週間の連続運転を実施したが、気相重合器は安定しており、反応器からの重合体粒子の排出もスムーズであり、極めて安定した運転が可能であった。結果を表１に示す。
【００８４】
【比較例１】
実施例１において、触媒の供給位置をｌ＝０．０Ｄ、ｈ＝０．５９Ｈとした以外は実施例１と同様にしてエチレンと1-ヘキセンとを共重合した。
【００８５】
上記のような条件下で、約１０時間運転後、触媒供給位置近傍の重合器壁面の表面温度が約９５℃まで上昇し、その後ポリマー塊生成によるポリマー抜き出し不良で運転を停止した。結果を表１に示す。
【００８６】
【比較例２】
実施例１において、触媒の供給位置をｌ＝０．２０Ｄ、ｈ＝０．０５Ｈとした以外は実施例１と同様にしてエチレンと1-ヘキセンとを共重合した。
【００８７】
上記のような条件下で、約２０時間運転後、シート状のポリマー生成によるポリマー抜き出し不良で運転を停止した。結果を表１に示す。
【００８８】
【比較例３】
実施例１において、触媒の供給位置をｌ＝０．２５Ｄ、ｈ＝０．９３Ｈとした以外は実施例１と同様にしてエチレンと1-ヘキセンとを共重合した。
【００８９】
上記のような条件下で、約１５時間運転後、シート状のポリマー生成によるポリマー抜き出し不良で運転を停止した。結果を表１に示す。
【００９０】
【比較例４】
実施例１において、触媒の供給位置をｌ＝０．２５Ｄ、ｈ＝０．３Ｈとし、触媒フィードノズル先端での随伴ガス流速を１．２ｍ／秒とした以外は実施例１と同様にしてエチレンと1-ヘキセンとを共重合した。
【００９１】
上記のような条件下で、約２４時間運転後、塊状のポリマー生成によるポリマー抜き出し不良で運転を停止した。結果を表１に示す。
【００９２】
【比較例５】
実施例１において、触媒の供給位置をｌ＝０．２５Ｄ、ｈ＝０．３Ｈとし、触媒フィードノズル先端での随伴ガス流速を８０ｍ／秒とした以外は実施例１と同様にしてエチレンと1-ヘキセンとを共重合した。
【００９３】
上記のような条件下で、約１２時間運転後、循環ガス中に同伴された微粉ポリマーが循環ライン内で重合、成長し反応器の分散板が詰った。結果を表１に示す。
【００９４】
【比較例６】
実施例１において、触媒の供給位置をｌ＝０．０５Ｄ、ｈ＝０．３Ｈとし、触媒フィードノズル先端での随伴ガス流速を１．２ｍ／秒とした以外は実施例１と同様にしてエチレンと1-ヘキセンとを共重合した。
【００９５】
上記のような条件下で、約８時間運転後、触媒フィードノズル内で生成した重合体により触媒フィードノズルが詰った。結果を表１に示す。
【００９６】
【表１】

【図面の簡単な説明】
【図１】 本発明で用いられるオレフィンの気相重合装置の一例を示す概略図である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a process for gas phase polymerization of olefins. More specifically, an olefin (co) polymer having excellent fluidity can be produced in a stable and economically advantageous manner over a long period of time. The present invention relates to a method for gas phase polymerization of olefins.
[0002]
TECHNICAL BACKGROUND OF THE INVENTION
Olefin polymers such as polyethylene, polypropylene, ethylene / α-olefin copolymers, and propylene / α-olefin copolymers are widely used as bumper and film molding materials.
[0003]
  Such an olefin polymer has been conventionally prepared by solution polymerization, suspension polymerization or gas phase polymerization in the presence of a titanium-based solid catalyst component containing magnesium, titanium and halogen as essential components (co-polymer). ) Manufactured by polymerizing. In recent years, as a catalyst capable of (co) polymerizing olefins with higher polymerization activity,Group 4A metallocene solid catalyst comprising a solid catalyst component containing a metallocene metal compound and an organoaluminum component has been developed.
[0004]
By the way, when olefin polymerization is carried out by the gas phase polymerization method in the presence of the solid catalyst as described above, the polymer can be obtained in the form of particles, and the polymer precipitation step after the polymerization or the solvent separation step becomes unnecessary. . Therefore, it is known that the manufacturing process can be simplified and the manufacturing cost can be reduced.
[0005]
In such a gas phase polymerization method, a solid catalyst and an olefin are continuously supplied to a fluidized bed reactor to polymerize or copolymerize the olefin in the fluidized bed, and the resulting particulate polymer is continuously produced. This is a method of continuously performing (co) polymerization of olefins by extracting.
[0006]
However, when the olefin is vapor-phase polymerized using a fluidized bed reactor, polymer lumps, sheets, etc. are generated in the fluidized bed, the flow of polymer particles is inhibited, and the mixed state in the fluidized bed becomes uneven. In some cases, long-term stable operation could not be achieved. In addition, particulate polymer or the like entrained in the circulating gas from the fluidized bed adheres to the circulating gas piping wall, polymerizes and grows inside the piping to block the piping, or the grown polymer peels off the piping wall and gas In some cases, a continuous operation could not be performed stably over a long period of time, for example, by blocking the holes in the dispersion plate. Such a problem is particularly remarkable when polymerization is carried out using a highly active metallocene solid catalyst.
[0007]
As a result of studying in view of such conventional technology, the present inventors have obtained the following knowledge. In the fluidized bed, there is a region where the linear velocity of the polymer particles becomes small, and in this region, the flow of gas and particles and heat removal are insufficient. Even in such a region, when the polymer grows and the polymer particles themselves are melted by the reaction heat generated by the grown polymer, sheeting or polymer mass is generated. In particular, metallocene catalysts are highly active, and thus the above-described problems are remarkable.
[0008]
As a result of intensive studies based on the above findings, the present inventors have reduced the generation of polymer lumps and sheet-like materials in the fluidized bed when a solid catalyst is supplied to a specific position of the reactor. And the blockage of piping and gas dispersion plates can be reduced.
[0009]
Further, as a method for supplying the solid catalyst to the reactor, a method for supplying the solid catalyst to the reactor by gas pressure is generally used. As the gas used here (associated gas), for example, an inert gas such as nitrogen or argon is generally used as described in JP-A-58-201802. When an inert gas is used as the accompanying gas as described above, the inert gas in the reactor must be discharged out of the reactor in order to prevent accumulation of the inert gas in the reactor. However, when the inert gas in the reactor is released to the outside of the reactor, the olefin gas is also released along with this, resulting in a large economic loss. As a method for solving this, there is a method in which an olefin gas used for polymerization or a mixed gas of the olefin gas and an inert gas is used as an accompanying gas.
[0010]
As a result of intensive studies in view of such conventional techniques, the present inventors have supplied olefin gas or olefin as an accompanying gas when supplying the solid catalyst to a specific position of the reactor and supplying the solid catalyst to the reactor. When a mixed gas of gas and inert gas is used, the generation of polymer lumps and sheet-like materials in the fluidized bed can be further reduced, and the blockage of piping, gas dispersion plates, etc. can be further reduced. In addition, the present invention has been completed by finding that it is economically advantageous.
[0011]
OBJECT OF THE INVENTION
The present invention has been made in view of the prior art as described above, and in the gas phase polymerization of olefin in the presence of a solid catalyst, it is a stable and economically advantageous method over a long period of time. It is an object of the present invention to provide a method for vapor phase polymerization of olefin that can produce an olefin (co) polymer having excellent fluidity.
[0012]
SUMMARY OF THE INVENTION
  The method for vapor phase polymerization of olefin according to the present invention involves the polymerization of olefin in the gas phase in the presence of a solid catalyst in which a catalyst component is supported on a fine particle carrier.
  The solid catalyst is positioned 0.02D to 0.5D (where D is the diameter of the inner wall of the reactor) from the inner wall of the reactor, and 0.1H to 0.9H (where H is the diameter of the gas dispersion plate of the reactor). As a companion gas when the solid catalyst is supplied to the reactor.Contains 10 to 100 mol% of olefin gasUse gas toThe fluidized bed gas superficial velocity of the reactor is 0.2 to 1.0 m / sec,The flow rate of the accompanying gas at the supply port of the catalyst feed nozzle that supplies the solid catalyst to the reactor is 2 to 100 times the fluidized bed gas superficial velocity in the reactor.The polymerization temperature is 20 to 130 ° C., and the polymerization pressure is 1 to 100 kg / cm. ² Is in the rangeIt is characterized by that.
[0014]
When the olefin is vapor-phase polymerized under the above conditions, the generation of polymer lumps, sheet-like materials, etc. in the fluidized bed can be reduced, and blockage of piping, gas dispersion plates, etc. can be reduced. An olefin (co) polymer having excellent fluidity can be produced stably over a long period of time. In addition, since an olefin gas or a gas containing an olefin gas is used as an accompanying gas when supplying the solid catalyst, it is not necessary to discharge an inert gas in the reactor to the outside of the reactor, and an accompanying gas is not required. This is economically advantageous as compared with the case of using an active gas.
[0015]
  In the present invention, the solid catalyst is
(A) including a ligand having a cyclopentadienyl skeletonGroup 4A transition metal compound of
(B) an organoaluminum oxy compound;
(C) From particulate carrier
It is preferable that the metallocene-based solid catalyst to be formed.
[0016]
The olefin gas phase polymerization method of the present invention is suitable for the olefin gas phase polymerization method using the metallocene solid catalyst as described above.
In the present specification, the term “polymerization” may be used to mean not only homopolymerization but also copolymerization, and the term “polymer” refers not only to homopolymers but also to copolymerizations. It may be used in the meaning that also includes coalescence.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the gas phase polymerization method of olefin according to the present invention will be described in detail with reference to FIG.
[0018]
FIG. 1 is a schematic view showing an example of an olefin gas phase polymerization apparatus used in the present invention.
In the present invention, the solid catalyst is supplied to the fluidized bed reactor 3 through the catalyst feed nozzle 2, for example.
[0019]
Gaseous polymerized olefin and the like are continuously supplied from, for example, the line 9 and are blown from the lower part of the fluidized bed reactor 3 through the circulation line 6 through the gas dispersion plate 4 such as a perforated plate. . Thereby, the fluidized bed (reaction system) 5 is maintained in a fluidized state. The olefin blown into the fluidized bed 5 in which such a solid catalyst is maintained in a fluidized state undergoes a polymerization reaction to produce polymer particles [olefin (co) polymer]. The produced polymer particles are continuously withdrawn from the fluidized bed reactor 3 via the line 11. The unreacted gaseous olefin or the like that has passed through the fluidized bed 5 is decelerated in the deceleration zone 3 a provided above the fluidized bed reactor 3 and discharged outside the fluidized bed reactor 3. Is removed and circulated from the circulation line 6 to the fluidized bed 5 again. Such polymerization can also be carried out in two or more stages.
[0020]
In the present invention, the fluidized bed (reaction system) 5 can also be mechanically stirred. Stirring can be performed using various types of stirrers such as a squid type stirrer, a screw type stirrer, and a ribbon stirrer.
[0021]
In the present invention, the solid catalyst is 0.02D to 0.5D, preferably 0.02D to 0.4D, more preferably 0.05D to 0.35D, particularly preferably 0.1D to 0, from the inner wall of the reactor. .Supply to 3D range position. Here, D is the diameter of the inner wall of the reactor.
[0022]
Since the position as described above is a region where the flow and dispersion and mixing of gas and polymer particles are sufficient, when the solid catalyst is supplied to the position as described above, the solid catalyst is quickly dispersed and the gas and polymer particles are dispersed. It reacts in a region where the flow, dispersion and mixing of particles are sufficient. For this reason, heat removal is quickly performed, the melting of the polymer does not occur, the fusion of the polymer particles can be prevented, and the occurrence of sheeting and polymer lump hardly occurs.
[0023]
In the present invention, the solid catalyst is supplied from the gas dispersion plate of the reactor to a height of 0.1H to 0.9H, preferably 0.2H to 0.5H, more preferably 0.2H to 0.4H. To do. Here, H is the height from the gas dispersion plate to the fluidized bed powder surface (the bed height of the fluidized bed). The bed height of the fluidized bed can be determined according to a method for determining by the reactor differential pressure, for example, as follows.
[0024]
The differential pressure between the inside of the fluidized bed and the non-fluid space area (deceleration zone) at the top of the fluidized bed is expressed as h at two locations above and below the fluidized bed, that is, from the dispersion plate₂, H₁(Cm) (h₂> H₁) Measure at the position. The lower measurement position is the height from the bottom of the fluidized bed (h₁) Is as small as possible, and the upper measurement position is the height from the bottom of the fluidized bed (h₂) Is set to a value equal to or greater than 1/2 of the fluidized bed height (H). This differential pressure is measured by, for example, a diaphragm type differential pressure oscillator.
[0025]
Here, the height from the bottom of the fluidized bed (h₂) Is the differential pressure value measured in₂(G / cm²) And the height from the bottom of the fluidized bed (h₁) Is the differential pressure value measured in₁(G / cm²).
[0026]
Differential pressure value ΔP measured at these two locations₁, ΔP₂And the distance between the two measurement positions (h₂-H₁) To obtain the fluidized bed height (H) from the following formula.
[0027]
[Expression 1]

[0028]
In the fluidized bed height measurement method as described above, the fluidized bulk density (ΔP₁-ΔP₂) / (H₂-H₁) Is taken into consideration, the fluidized bed height can be accurately determined even if the density of the powder forming the fluidized bed changes.
[0029]
When the solid catalyst is supplied at such a height as described above, the amount of fine particle polymer, catalyst particles and the like entrained in the circulation gas is reduced, and the circulation gas and the gas dispersion plate are less likely to be clogged.
[0030]
In the present invention, the solid catalyst is located at a position of 0.02D to 0.5D from the inner wall of the reactor and at a height of 0.1H to 0.9H from the gas dispersion plate of the reactor, preferably the reactor. 0.02D to 0.4D position from the inner wall and 0.2H to 0.5H height from the gas dispersion plate of the reactor, more preferably 0.02D to 0.4D position from the inner wall of the reactor And a height of 0.2H to 0.5H from the gas dispersion plate of the reactor, particularly preferably at a position of 0.1D to 0.3D from the inner wall of the reactor, and from the gas dispersion plate of the reactor It is desirable to supply at a height of 0.2H to 0.4H.
[0031]
When the solid catalyst is supplied to the position and height as described above, it is difficult for sheeting and polymer lump generation to occur, and the circulating gas and gas dispersion plate are less likely to be clogged.
[0032]
In order to supply the catalyst to the position as described above, the position (l) of the tip of the catalyst feed nozzle 2 is 0.02D to 0.5D, preferably 0.02D to 0.4D, more preferably from the inner wall of the reactor. The height (h) at the tip of the catalyst feed nozzle 2 is 0.1H to 0.9H from the gas dispersion plate 4, preferably 0. .2H to 0.5H, more preferably 0.2H to 0.4H.
[0033]
The direction of the catalyst feed nozzle 2 is preferably horizontal or horizontal to downward, and more preferably installed at an angle of 0 to 50 ° downward from the horizontal. The number of catalyst feed nozzles is not particularly limited, but is preferably 2 to 4.
[0034]
In the present invention, when the solid catalyst is supplied from the catalyst feed nozzle 2 to the specific position as described above, an olefin gas or a gas containing an olefin gas is used as the accompanying gas. At this time, the flow rate of the accompanying gas at the supply port of the catalyst feed nozzle 2 is 2 to 100 times, preferably 5 to 70 times, the fluidized bed gas superficial velocity of the reactor (circulation gas linear velocity). Preferably it is 10 to 50 times. The fluidized bed gas superficial velocity of the reactor is usually 0.2 to 1.0 m / sec, preferably 0.4 to 0.8 m / sec.
[0035]
As the olefin gas, one or more olefins usually used for polymerization are used.
Examples of the gas containing olefin gas include an inert gas containing one or more olefins used for polymerization, and examples of the inert gas include nitrogen gas and argon gas. In the gas containing such an olefin gas, the olefin gas is preferably contained in a proportion of 10 to 100 mol%, preferably 20 to 90 mol%.
[0036]
If the flow rate of the associated gas at the supply port of the catalyst feed nozzle is slower than the above range, solid catalyst particles may be deposited and clogged in the supply pipe, the polymer particles in the fluidized bed may flow backward to the catalyst feed nozzle, or the catalyst feed nozzle May produce bulk polymer in the vicinity. If the flow rate of the accompanying gas at the supply port of the catalyst feed nozzle is faster than the above range, the solid catalyst particles may be crushed in the supply pipe, or the solid catalyst particles may penetrate through the fluidized bed in the reactor and In this case, a block polymer may be formed, or solid catalyst particles may blow through the gas layer from the upper part of the powder surface of the fluidized bed.
[0037]
When an olefin gas or a gas containing an olefin gas is used as an accompanying gas when supplying the solid catalyst, it is not necessary to discharge the inert gas in the reactor to the outside of the reactor, and the inert gas is used as the accompanying gas. It is economically advantageous compared to the case.
[0038]
When supplying a solid catalyst to a specific position of the reactor as described above and using an olefin gas or a mixed gas of an olefin gas and an inert gas as an accompanying gas when supplying the solid catalyst to the reactor, The generation of polymer lumps and sheet-like materials in the fluidized bed can be reduced, and the blockage of piping and gas dispersion plates can be reduced, which is economically advantageous.
[0039]
  As the solid catalyst used in the gas phase polymerization method of olefin according to the present invention, a titanium-based solid catalyst containing magnesium, titanium, and halogen as essential components,Group 4Examples thereof include a metallocene solid catalyst comprising a transition metal metallocene compound, an organoaluminum component, and a particulate carrier, and it is particularly preferable to use a metallocene solid catalyst as described later.
[0040]
  The metallocene solid catalyst preferably used in the present invention has a polymerization activity of 50000 g / m.
It is preferable that the catalyst is a highly active catalyst of mol / transition metal / hour or more. Specifically, for example, (A) a ligand having a cyclopentadienyl skeleton is included.Group 4A transition metal compound;
(B) an organoaluminum oxy compound;
(C) From particulate carrier
Examples of the formed solid metallocene catalyst can be given.
[0041]
  (A) including a ligand having a cyclopentadienyl skeleton forming a metallocene solid catalystGroup 4As a transition metal compound, the compound represented by the following general formula (I) can be illustrated.
[0042]
    ML_X       (I)
  Where M isGroup 4One transition metal atom selected from the following transition metal atoms is preferable, and zirconium, titanium, or hafnium is preferable.
[0043]
x is the valence of the transition metal and represents the number of L.
L represents a ligand or group coordinated to the transition metal, and at least one L is a ligand having a cyclopentadienyl skeleton, and other than the ligand having the cyclopentadienyl skeleton. L is a hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group, an aryloxy group, a trialkylsilyl group, SO_ThreeR is a group or atom selected from the group consisting of R (wherein R is a hydrocarbon group having 1 to 8 carbon atoms which may have a substituent such as halogen), a halogen atom, and a hydrogen atom. is there.
[0044]
Examples of the ligand having a cyclopentadienyl skeleton include cyclopentadienyl group, alkyl-substituted cyclopentadienyl group, indenyl group, alkyl-substituted indenyl group, 4,5,6,7-tetrahydroindenyl group, and fluorenyl. Examples include groups. These groups may be substituted with a halogen atom, a trialkylsilyl group or the like.
[0045]
When the compound represented by the general formula (I) includes two or more ligands having a cyclopentadienyl skeleton, the ligands having two cyclopentadienyl skeletons are alkylene groups, It may be bonded through a substituted alkylene group, a silylene group, a substituted silylene group or the like.
[0046]
  Group 4As the transition metal compound (A), a compound having two ligands having a cyclopentadienyl skeleton is preferably used, and a compound having two ligands having M as zirconium and having a cyclopentadienyl skeleton is preferable. More preferably used.
[0047]
Specific examples of the organoaluminum oxy compound (B) forming the metallocene solid catalyst include conventionally known aluminoxanes and benzene-insoluble organoaluminum oxy compounds exemplified in JP-A-2-78687. Can be mentioned.
[0048]
Specifically, as the particulate carrier (C) for forming the metallocene solid catalyst, SiO₂, Al₂O_Three, MgO, ZrO₂TiO₂, B₂O_Three, CaO, ZnO, BaO, ThO₂Or a mixture containing these, for example SiO₂-MgO, SiO₂-Al₂O_Three, SiO₂-TiO₂, SiO₂-V₂O_Five, SiO₂-Cr₂O_Three, SiO₂-TiO₂Examples include inorganic carriers such as -MgO, and organic carriers such as polyethylene, polypropylene, poly 1-butene, poly 4-methyl-1-pentene, and styrene-divinylbenzene copolymer.
[0049]
  The fine particle carrier (C) has an average particle diameter of 1 to 300 μm, preferably 10 to 200 μm.
  The metallocene-based solid catalyst preferably used in the present invention is the above-mentionedGroup 4Although formed from a transition metal compound (A), an organoaluminum oxy compound (B), and a particulate carrier (C), an organoaluminum compound (D) may be included as required.
[0050]
As such an organoaluminum compound (D), for example, an organoaluminum compound represented by the following general formula (II) can be exemplified.
R^a _nAlX_3-n  … (II)
(Wherein R^aIs a C1-C12 hydrocarbon group, X is a halogen atom or a hydrogen atom, and n is 1-3. )
Specific examples of such an organoaluminum compound (D) include trimethylaluminum, triethylaluminum, triisopropylaluminum, triisobutylaluminum and the like.
[0051]
As the organoaluminum compound (D), a compound represented by the following general formula (III) can also be used.
R^a _nAlY_3-n  (III)
(Wherein R^aIs the same as above, and Y is -OR.^bGroup, -OSiR^c _ThreeGroup, -OAlR^d ₂Group, -NR^e ₂Group, -SiR^f _ThreeGroup or -N (R^g) AlR^h ₂A group, n is 1-2, R^b, R^c, R^dAnd R^hIs a methyl group, an ethyl group, an isopropyl group, an isobutyl group, a cyclohexyl group, a phenyl group or the like;^eIs a hydrogen atom, a methyl group, an ethyl group, an isopropyl group, a phenyl group, a trimethylsilyl group, etc., and R^fAnd R^gIs a methyl group, an ethyl group or the like. )
The metallocene-based solid catalyst is a conventionally known method from (A) a transition metal compound, (B) an organoaluminum oxy compound, (C) a particulate carrier, and, if necessary, (D) an organoaluminum compound. It is formed by.
[0052]
In preparing the metallocene solid catalyst, the (A) transition metal compound (in terms of transition metal atom) is usually 0.001 to 1.0 mmol, preferably 0.01 to 0, per 1 g of (C) particulate carrier. In an amount of 0.5 mmol, (B) the organoaluminum oxy compound is usually 0.1 to 100 mmol, preferably 0.5 to 20 mmol, and (D) the organoaluminum compound is usually 0.001 to 1000 mmol. , Preferably in an amount of 2 to 500 mmol.
[0053]
Such metallocene-based solid catalyst particles have a particle size of 1 to 300 μm, preferably 10 to 100 μm.
The metallocene-based solid catalyst may contain other components useful for olefin polymerization, such as an electron donor and a reaction aid, as necessary, in addition to the above catalyst components.
[0054]
In the metallocene solid catalyst, olefin may be prepolymerized.
Such a metallocene-based solid catalyst can (co) polymerize olefins with excellent polymerization activity.
[0055]
In general, highly active Ziegler-Natta type and highly active metallocene type catalysts are likely to be hindered by impurities such as water, alcohol, oxygen, carbon dioxide, carbon monoxide, etc., and such impurities are added to seed powder, monomer, inert gas, etc. May be included. In this case, the addition of an organoaluminum compound, preferably a trialkylaluminum, as an activity inhibition inhibitor can prevent reduction in catalytic activity due to the activity inhibitor. However, it is known that the addition of organic aluminum increases the ash content in the resin, which may cause a reduction in product quality, and the organoaluminum compound is also weak but has an activity inhibiting effect on the catalyst. . For this reason, it is meaningful to add an organoaluminum compound while an activity inhibitor is contained, but it is preferable not to use an organoaluminum compound in a system that does not contain an activity inhibitor. Therefore, when performing vapor phase polymerization, it is desirable to add the organoaluminum compound (D) only when the polymerization system contains an activity inhibitor.
[0056]
Here, preferred examples of the olefin that can be polymerized by the method of the present invention include α-olefins having 2 to 18 carbon atoms, such as ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl- 1-pentene, 3-methyl-1-pentene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, etc. It is done.
[0057]
Further, cyclopentene, cycloheptene, norbornene, 5-methyl-2-norbornene, tetracyclododecene, 2-methyl 1,4,5,8-dimethano-1,2,3,4,4a, 5,8,8a- Also included are octahydronaphthalene, styrene, vinylcyclohexane and the like.
[0058]
In the present invention, these olefins are polymerized or copolymerized.
In addition to olefins, polyenes such as butadiene, isoprene, 1,4-hexadiene, dicyclopentadiene, and 5-ethylidene-2-norbornene can be copolymerized.
[0059]
  When the olefin is polymerized by the method of the present invention using the solid catalyst as described above, the solid catalyst is supported on the solid catalyst per liter of polymerization volume.Group 4In terms of the transition metal atom in the transition metal compound (A), it is usually used at a rate of 0.00001 to 1.0 mmol / hour, preferably 0.0001 to 0.1 mmol / hour.
[0060]
The polymerization temperature is desirably in the range of 20 to 130 ° C, preferably 50 to 120 ° C, more preferably 60 to 100 ° C. The polymerization pressure depends on the olefin to be polymerized and the fluidized state of the fluidized bed (reaction system). Although it is different, it is usually 1 to 100 kg / cm², Preferably 2-40 kg / cm²It is desirable to be in the range.
[0061]
In the polymerization, a non-polymerizable hydrocarbon or a polymerization inert gas such as nitrogen that does not polymerize under olefin polymerization conditions can coexist.
As such a non-polymerizable hydrocarbon, an easily volatile low-boiling non-polymerizable hydrocarbon may be used. This low-boiling point non-polymerizable hydrocarbon is likely to condense at a low temperature and can be easily liquefied by a general refrigerant such as water in a condenser (not shown) provided in the circulation line 6, for example. preferable. Specific examples of such low boiling point non-polymerizable hydrocarbons include saturated hydrocarbons, and more specifically, for example, propane, n-butane, i-butane, n-pentane, i- Examples include pentane, cyclopentane, n-hexane, 2-methylpentane, and cyclohexane. These can be used alone or in combination.
[0062]
【The invention's effect】
The olefin gas phase polymerization method according to the present invention does not cause sheeting or polymer lump generation, and does not block the circulating gas or the gas dispersion plate, so that the olefin can be stably polymerized over a long period of time. Moreover, it is economically advantageous compared with the case where an inert gas is used as the accompanying gas. Furthermore, the polymer obtained by the method of the present invention is excellent in fluidity.
[0063]
【Example】
EXAMPLES Hereinafter, although this invention is demonstrated further more concretely based on an Example, this invention is not limited to these Examples.
[0064]
[Example 1]
[Preparation of catalyst]
Silica (SiO2) dried at 250 ° C. for 10 hours₂) 10 kg was suspended in 154 liters of toluene and then cooled to 0 ° C. To this suspension, 82.0 liters of a toluene solution of methylaminoxan (Al = 1.33 mol / liter) was added dropwise over 1 hour. At this time, the temperature in the system was kept at 0 ° C. Subsequently, the mixture was reacted at 0 ° C. for 30 minutes, then heated to 95 ° C. over 1.5 hours, and reacted at that temperature for 20 hours. Thereafter, the temperature was lowered to 60 ° C., and the supernatant was removed by decantation. The solid component thus obtained was washed twice with toluene and then resuspended in 100 liters of toluene.
[0065]
To the suspension thus obtained, 24.0 liters of a toluene solution of bis (methylbutylcyclopentadienyl) zirconium dichloride (Zr = 27.0 mmol / liter) was added dropwise at 80 ° C. over 30 minutes. The mixture was further reacted at 80 ° C. for 2 hours. Thereafter, the supernatant was removed and washed twice with hexane to obtain a solid catalyst containing 5.1 mg of zirconium and 189 mg of aluminum per 1 g of silica. The obtained solid catalyst was a catalyst having a substantially spherical shape.
[0066]
[Gas phase polymerization]
The reaction system 5 as shown in FIG. 1 has a diameter of 100 cmφ, a height of 180 cm, a fluidized bed volume of 1400 liters, and a fluidized bed reactor 3 (continuous polymerization apparatus) having a maximum diameter of 140 cmφ in the deceleration zone 3a. Gas phase copolymerization with 1-hexene was continuously carried out.
[0067]
In the fluidized bed 5 of the fluidized bed reactor 3, the solid catalyst obtained as described above was converted into Zr atoms at an amount of 0.46 mmol / hour, l = 0.10 D, h = 0. At the position of 43H, 100% ethylene is supplied together with the accompanying gas, and 1-hexene is 8 kg / hour and hydrogen is 75 liter / hour so that the total amount of ethylene and the accompanying gas is 75 kg / hour. Feeded continuously from line 9.
[0068]
The polymerization conditions in the gas phase polymerization apparatus are as follows: pressure 20 kg / cm²-G, polymerization temperature of 85 ° C., residence time of 4.2 hours, fluidized bed gas superficial velocity in the reactor was maintained at 0.7 m / sec, and accompanying gas flow rate at the tip of the catalyst feed nozzle was maintained at 10 m / sec.
[0069]
The gas composition in the gas phase polymerization reactor was 73.0 mol% ethylene, 1.6 mol% 1-hexene, 330 ppm hydrogen, and the remainder was nitrogen.
The produced polyethylene (LLDPE) was continuously extracted from the line 11 in an amount of 70 kg / hour.
[0070]
The polyethylene obtained as described above has a melt flow rate (MFR) of 4.0 g / 10 min and a density of 0.920 g / cm.^ThreeThe particles were extremely fluid.
[0071]
Under the above conditions, continuous operation for one week was carried out, but the gas phase polymerization reactor was stable, the polymer particles were smoothly discharged from the reactor, and extremely stable operation was possible. It was. The results are shown in Table 1.
[0072]
[Example 2]
In Example 1, the catalyst supply position was l = 0.25D, h = 0.14H, and the accompanying gas flow rate at the tip of the catalyst feed nozzle was 3 m / sec. -Copolymerized with hexene.
[0073]
Under the above conditions, continuous operation for one week was carried out, but the gas phase polymerization reactor was stable, the polymer particles were smoothly discharged from the reactor, and extremely stable operation was possible. It was. The results are shown in Table 1.
[0074]
[Example 3]
In Example 1, ethylene and 1-hexene were copolymerized in the same manner as in Example 1 except that the catalyst supply position was set to l = 0.35D and h = 0.79H.
[0075]
Under the above conditions, continuous operation for one week was carried out, but the gas phase polymerization reactor was stable, the polymer particles were smoothly discharged from the reactor, and extremely stable operation was possible. It was. The results are shown in Table 1.
[0076]
[Example 4]
In Example 1, except that the supply position of the catalyst was l = 0.01D, h = 0.05H, and the accompanying gas flow rate at the tip of the catalyst feed nozzle was 15 m / sec. -Copolymerized with hexene.
[0077]
Under the above conditions, continuous operation for one week was carried out, but the gas phase polymerization reactor was stable, the polymer particles were smoothly discharged from the reactor, and extremely stable operation was possible. It was. The results are shown in Table 1.
[0078]
[Example 5]
In Example 1, ethylene and 1-hexene were copolymerized in the same manner as in Example 1 except that the catalyst supply position was set to l = 0.01D and h = 0.05H.
[0079]
Under the above conditions, continuous operation for one week was carried out, but the gas phase polymerization reactor was stable, the polymer particles were smoothly discharged from the reactor, and extremely stable operation was possible. It was. The results are shown in Table 1.
[0080]
[Example 6]
In Example 1, the catalyst supply position is 1 = 0.25D, h = 0.3H, the accompanying gas flow rate at the tip of the catalyst feed nozzle is 5 m / sec, and the fluidized bed gas superficial velocity in the reactor is 0. Ethylene and 1-hexene were copolymerized in the same manner as in Example 1 except for changing to 0.55 m / sec.
[0081]
Under the above conditions, continuous operation for one week was carried out, but the gas phase polymerization reactor was stable, the polymer particles were smoothly discharged from the reactor, and extremely stable operation was possible. It was. The results are shown in Table 1.
[0082]
[Example 7]
In Example 1, the catalyst supply position is 1 = 0.25D, h = 0.3H, the accompanying gas flow rate at the tip of the catalyst feed nozzle is 40 m / sec, and the fluidized bed gas superficial velocity in the reactor is 0. Ethylene and 1-hexene were copolymerized in the same manner as in Example 1 except for changing to 0.55 m / sec.
[0083]
Under the above conditions, continuous operation for one week was carried out, but the gas phase polymerization reactor was stable, the polymer particles were smoothly discharged from the reactor, and extremely stable operation was possible. It was. The results are shown in Table 1.
[0084]
[Comparative Example 1]
In Example 1, ethylene and 1-hexene were copolymerized in the same manner as in Example 1 except that the catalyst supply position was set to l = 0.0D and h = 0.59H.
[0085]
After operating for about 10 hours under the above conditions, the surface temperature of the wall of the polymerizer near the catalyst supply position rose to about 95 ° C., and then the operation was stopped due to poor polymer extraction due to polymer lump formation. The results are shown in Table 1.
[0086]
[Comparative Example 2]
In Example 1, ethylene and 1-hexene were copolymerized in the same manner as in Example 1 except that the catalyst supply position was set to l = 0.20D and h = 0.05H.
[0087]
After the operation for about 20 hours under the above-mentioned conditions, the operation was stopped due to poor polymer extraction due to the formation of a sheet-like polymer. The results are shown in Table 1.
[0088]
[Comparative Example 3]
In Example 1, ethylene and 1-hexene were copolymerized in the same manner as in Example 1 except that the catalyst supply position was set to l = 0.25D and h = 0.93H.
[0089]
After operating for about 15 hours under the above conditions, the operation was stopped due to poor polymer extraction due to the formation of a sheet-like polymer. The results are shown in Table 1.
[0090]
[Comparative Example 4]
In Example 1, ethylene was supplied in the same manner as in Example 1 except that the catalyst supply position was 1 = 0.25D, h = 0.3H, and the accompanying gas flow rate at the tip of the catalyst feed nozzle was 1.2 m / sec. And 1-hexene were copolymerized.
[0091]
After operating for about 24 hours under the above conditions, the operation was stopped due to poor polymer extraction due to the formation of a massive polymer. The results are shown in Table 1.
[0092]
[Comparative Example 5]
In Example 1, ethylene and 1 were used in the same manner as in Example 1 except that the catalyst supply position was 1 = 0.25D, h = 0.3H, and the accompanying gas flow rate at the tip of the catalyst feed nozzle was 80 m / sec. -Copolymerized with hexene.
[0093]
After operation for about 12 hours under the above conditions, the fine powder polymer entrained in the circulating gas was polymerized and grown in the circulation line, and the dispersion plate of the reactor was clogged. The results are shown in Table 1.
[0094]
[Comparative Example 6]
In Example 1, ethylene was supplied in the same manner as in Example 1 except that the catalyst supply position was 1 = 0.05D, h = 0.3H, and the accompanying gas flow rate at the tip of the catalyst feed nozzle was 1.2 m / sec. And 1-hexene were copolymerized.
[0095]
After operating for about 8 hours under the above conditions, the catalyst feed nozzle was clogged with the polymer produced in the catalyst feed nozzle. The results are shown in Table 1.
[0096]
[Table 1]

[Brief description of the drawings]
FIG. 1 is a schematic view showing an example of an olefin gas phase polymerization apparatus used in the present invention.

Claims (2)

When polymerizing an olefin in the gas phase in the presence of a solid catalyst in which a catalyst component is supported on a particulate carrier,
The solid catalyst is positioned at 0.02D to 0.5D (where D is the diameter of the reactor inner wall) from the inner wall of the reactor, and 0.1H to 0.9H (where H is the diameter of the reactor inner wall). Is a gas containing 10 to 100 mol% of olefin gas as an accompanying gas when the solid catalyst is supplied to the reactor. The fluidized bed gas superficial velocity of the reactor is 0.2 to 1.0 m / second, and the flow rate of the accompanying gas at the supply port of the catalyst feed nozzle for supplying the solid catalyst to the reactor is the reaction rate. Gas phase polymerization method of olefin, characterized in that it is ^{2 to} 100 times the fluidized bed gas superficial velocity in the vessel, the polymerization temperature is 20 to 130 ° C., and the polymerization pressure is in the range of 1 to 100 kg / cm ^2. . The solid catalyst is
(A) a Group 4 transition metal compound containing a ligand having a cyclopentadienyl skeleton;
(B) an organoaluminum oxy compound;
The method for vapor phase polymerization of olefin according to claim 1, which is a metallocene solid catalyst formed from (C) a particulate carrier.

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