JP3966640B2 - Novel silicon phthalocyanine compound and electrophotographic photoreceptor using the same - Google Patents

Description

【０００９】
上記ジヒドロキシシリコンフタロシアニン化合物にはアルキル、アルコキシ、ハロゲン原子置換基体が含有されても良い。
上記Ｘ線回折スペクトルは下記条件で測定したものである。
Ｘ線 Cu Kα1
電圧 40KV
電流 30mA
スタート角度 3.00deg
ストップ角度 40.00deg
ステップ角度 0.05deg
測定時間 0.50sec/step
【００１０】
本発明の新規結晶形ジヒドロキシシリコンフタロシアニン化合物は、例えば次のようにして製造することができる。ジアルコキシシリコンフタロシアニン化合物を、特開平１０−２３７３３９号公報等公知の方法で合成する。このジアルコキシシリコンフタロシアニンを特開平１０−２３７３４０号公報と同様の方法、すなわち水の存在下、 N−メチルピロリドン、エチレンカーボネート、プロピレンカーボネート、N,N-ジメチルホルムアミド、 N,N−ジメチルアセトアミド、ジメチルスルホキシド、スルホラン等の極性溶剤で加熱することにより、加水分解させると、加水分解と同時に新規結晶形ジヒドロキシシリコンフタロシアニン化合物が生成する。この際、ジアルコキシシリコンフタロシアニンの構造および製造条件によっては既知の結晶形のジヒドロキシシリコンフタロシアニン化合物となるが、例えば炭素数５以上のアルコキシ基を有するジアルコキシシリコンフタロシアニンを原料とし、加水分解条件を選ぶことにより本発明の結晶形ジヒドロキシシリコンフタロシアニンとすることができる。
【００１１】
このようにして処理された新規結晶形ジヒドロキシシリコンフタロシアニン化合物は、処理溶剤から単離、洗浄、乾燥することにより得られる。
次に、上記新規結晶形ジヒドロキシシリコンフタロシアニン化合物を感光層における光導電材料として使用した電子写真感光体について説明する。本発明の電子写真感光体において、導電性支持体上に被覆される感光層は、単層型構造からなるものであっても、あるいは電荷発生層および電荷輸送層からなる積層型構造であっても良い。また、導電性支持体と感光層との間に下引き層を形成してもよく、単層型構造では感光層上に、積層型構造では電荷輸送層上に表面保護層を設けていても良い。
【００１２】
導電性支持体としては、電子写真感光体として使用することができるものならばいかなるものでも良い。具体的には例えば、アルミニウム、銅、ニッケル等の金属ドラム、シートあるいはこれら金属箔のラミネート物、蒸着物が挙げられる。さらに、金属粉末、カーボンブラック、ヨウ化銅、高分子電解質等の導電物質を適当なバインダーとともに塗布して導電処理したプラスティックフィルム、プラスティックドラム、紙等が挙げられる。また、金属粉末、カーボンブラック、炭素繊維等の導電性物質を含有し、導電性となったプラスティックシートやドラムあるいは酸化スズ、酸化インジウム等の導電性金属酸化物層を表面に有するプラスティックフィルムなどが挙げられる。
【００１３】
下引き層は、導電性支持体からの不必要な電荷の注入を阻止するために有効であり、感光層の帯電を高める作用がある。さらに、感光層と導電性支持体との密着性を高める作用もある。下引き層を構成する材料としては、アルミニウム陽極酸化皮膜、酸化アルミニウム、水酸化アルミニウム、酸化チタン、表面処理酸化チタン等の無機物、ポリビニルアルコール、カゼイン、ポリビニルピロリドン、ポリアクリル酸、セルロース類、ゼラチン、デンプン類、ポリウレタン、ポリイミド、ポリアミド等の有機層、その他、有機ジルコニウム化合物、チタニウムキレート化合物、チタニウムアルコキシド化合物、有機チタニウム化合物、シランカップリング剤等が挙げられる。下引き層の膜厚は0.1 〜20μｍの範囲が好ましく、0.1 〜10μｍの範囲で使用するのが最も効果的である。
【００１４】
電子写真感光体が積層型構造を有する場合、電荷発生層は前記ジヒドロキシシリコンフタロシアニン化合物および結着樹脂から構成される。本発明では前記ジヒドロキシシリコンフタロシアニン化合物以外の電荷発生物質を併用しても良い。併用できる電荷発生物質は、本発明の結晶形ではないジヒドロキシシリコンフタロシアニン、ジアルコキシシリコンフタロシアニン、チタニルフタロシアニン、ガリウムフタロシアニン、インジウムフタロシアニン、無金属フタロシアニン等が挙げられる。また、上記以外のフタロシアニン系化合物、アゾ化合物、アントラキノン系化合物、ペリレン系化合物、多環キノン系化合物、スクアリック酸メチン系化合物等が挙げられるが、これらに制限されるものではない。結着樹脂は広範な絶縁性樹脂から選択することができる。好ましい結着樹脂としては、スチレン、酢酸ビニル、塩化ビニル、塩化ビニリデン、アクリル酸エステル、メタクリル酸エステル、アクリルアミド、アクリロニトリル、ビニルアルコール、エチルビニルエーテル、ビニルピリジン等のビニル化合物の重合体および共重合体、フェノキシ樹脂、ポリスルホン、ポリビニルアセタール、ポリビニルブチラール、ポリカーボネート、ポリエステル、ポリアミド、ポリウレタン、セルロースエステル、セルロースエーテル、エポキシ樹脂、ケイ素樹脂、アルキッド樹脂、ポリアリレート等が挙げられるが、これらに制限されるものではない。
【００１５】
電荷発生層は、上記結着樹脂を有機溶剤に溶解した溶液に前記ジヒドロキシシリコンフタロシアニン化合物を分散させて塗布液を調整し、それを導電性支持体上に塗布し、乾燥することによって形成することができる。分散処理の際には、一部溶解しても差し障りがない。分散処理する方法としては、公知の方法、例えば、ボールミル、サンドグラインドミル、遊星ミル、ロールミル、ペイントシェーカー等の方法を用いることができる。その場合、前記ジヒドロキシシリコンフタロシアニン化合物と結着樹脂との割合は、特に制限されないが、前記ジヒドロキシシリコンフタロシアニン化合物100 重量部に対して結着樹脂1 〜1000重量部、好ましくは10〜400 重量部の範囲である。ジヒドロキシシリコンフタロシアニン化合物の比率が高すぎる場合には、塗布液の安定性が低下し、低すぎる場合は、残留電位が高くなるので、組成比は上記範囲が適当である。使用する有機溶剤としては、テトラヒドロフラン、ジオキサン、エチレングリコールモノメチルエーテル等のエーテル類、アセトン、メチルエチルケトン、シクロヘキサノン等のケトン類、トルエン、キシレン等の芳香族炭化水素、モノクロロベンゼン、ジクロロベンゼン等のハロゲン化芳香族炭化水素、塩化メチレン、クロロホルム、四塩化炭素、ジクロロエタン、トリクロロエタン等のハロゲン化脂肪族炭化水素、メタノール、エタノール、イソプロパノール等のアルコール類、酢酸メチル、酢酸エチル等のエステル類、N,N-ジメチルホルムアミド、 N,N- ジメチルアセトアミド等のアミド類、ジメチルスルホキシド等のスルホキシド類等が挙げられる。塗布液は、ディップコーティング法、スプレーコーティング法、スピナーコーティング法、ビードコーティング法、ワイヤーバーコーティング法、ブレードコーティング法、ローラーコーティング法、カーテンコーティング法、リングコーティング法等のコーティング法により塗布することができる。塗布後の乾燥は、25〜250 ℃の温度で5 分〜3 時間の範囲で静止または送風下で行うことができる。また、形成される電荷発生層の膜厚は、通常0.1 〜5 μｍの範囲が適当である。
【００１６】
電荷輸送層は電荷輸送材料および結着樹脂、場合によって酸化防止剤等の添加物より構成される。電荷輸送材料は一般に電子輸送材料とホール輸送材料の２種に分類されるが、本発明の電子写真感光体はいずれも使用することができ、また、その混合物も使用できる。電子輸送材料としては、ニトロ基、シアノ基、エステル基等の電子吸引性基を有する電子吸引性化合物、例えば、2,4,7 −トリニトロフルオレノン、 2,4,5,7−テトラニトロフルオレノン等のニトロ化フルオレノン、テトラシアノキノジメタン、あるいはジフェノキノン等のキノン類が挙げられる。また、ホール輸送材料としては、電子供与性の有機光電性化合物、例えば、カルバゾール系、インドール系、イミダゾール系、オキサゾール系、チアゾール系、オキサジアゾール系、ピラゾール系、ピラゾリン系、チアジアゾール系、ベンゾオキサゾール系、ベンゾチアゾール系、ナフトチアゾール系等の複素環化合物、ジフェニルメタンなどのジアリールアルカン誘導体、トリフェニルメタンなどのトリアリールアルカン誘導体、トリフェニルアミンなどのトリアリールアミン誘導体、フェニレンジアミン誘導体、N ーフェニルカルバゾール誘導体、スチルベンなどのジアリールエチレン誘導体、ヒドラゾン系誘導体、ジアルキルアミノ基、ジフェニルアミノ基のような置換アミノ基、あるいはアルコキシ基、アルキル基のような電子供与基、あるいはこれらの電子供与基が置換した芳香族環基が置換した電子供与性の大きな化合物が挙げられる。また、ポリビニルカルバゾール、ポリグリシジルカルバゾール、ポリビニルピレン、ポリビニルフェニルアントラセン、ポリビニルアクリジン、ピレンーホルムアルデヒド樹脂等、上記化合物からなる基を主鎖もしくは側鎖に有する重合体も挙げられる。更に具体的には次の化合物が挙げられる。
【００１７】
【化２】

【００１８】
【化３】

【００１９】
【化４】

【００２０】
【化５】

【００２１】
また、結着樹脂としては、前記した電荷発生層に使用されるものと同様の絶縁性樹脂が使用できる。電荷輸送材料と結着樹脂との割合は、特に制限されないが、前記電荷輸送材料100 重量部に対して結着樹脂20〜3000重量部、好ましくは50〜1000重量部の範囲である。電荷輸送層は、上記電荷輸送材料および結着樹脂を前記した電荷発生層に使用されるものと同様の有機溶剤を用いて塗布液を調整した後、前記と同様の方法により塗布し、乾燥することによって形成することができる。また、電荷輸送層の膜厚は、通常5 〜50μｍの範囲が適当である。
【００２２】
電子写真感光体が単層型構造を有する場合は、感光層は前記ジヒドロキシシリコンフタロシアニン化合物、電荷輸送材料、結着樹脂から構成される。この時も積層型感光体と同様に、本発明のジヒドロキシシリコンフタロシアニン化合物以外の電荷発生物質を併用しても良い。電荷輸送材料および結着樹脂は、前期と同様なものが使用される。感光層には必要に応じて酸化防止剤、増感剤等の各種添加物を含んでいても良い。ジヒドロキシシリコンフタロシアニン化合物および電荷輸送材料と結着樹脂との割合は、ジヒドロキシシリコンフタロシアニン化合物および電荷輸送材料10重量部に対して結着樹脂2 〜300 重量部、ジヒドロキシシリコンフタロシアニン化合物と電荷輸送材料との割合は、ジヒドロキシシリコンフタロシアニン化合物1 重量部に対して電荷輸送材料0.01〜100 重量部の範囲が適当である。そして、前記と同様に塗布液を調整した後、塗布、乾燥することによって感光層が得られる。
【００２３】
【実施例】
以下、実施例によって、本発明をさらに具体的に説明するが、本発明は、その要旨を越えない限り以下の実施例によって制限されるものではない。
実施例１
「ジヒドロキシシリコンフタロシアニンの合成」
公知の方法で合成したビス（３−メトキシ−３−メチルブタノキシ）シリコンフタロシアニン１０ｇを水５ｇとＮ−メチルピロリドン９５ｇ（９５％ＮＭＰ水溶液）に添加し、１４８℃で２時間反応させた。生成物を熱ろ過し、ＮＭＰ、メタノールの順で洗浄した。次いで、メタノール１００ｍｌ中で室温撹拌した後、結晶をろ別し、乾燥してジヒドロキシシリコンフタロシアニン6.8 ｇを得た。構造解析はマススペクトル（ネガティブ測定）、ＩＲ（ＫＢｒ法）、元素分析で行った。図１にジヒドロキシシリコンフタロシアニンのマススペクトルを、図２にＩＲスペクトルを示す。マススペクトルではm/z ：５７４にジヒドロキシシリコンフタロシアニンのピークが確認された。ＩＲスペクトルでは１５１９、１０６８、８４０ｃｍ-1にジヒドロキシシリコンフタロシアニン特有の吸収が見られた（Ｅ．Ｃｉｌｉｂｅｒｔｏ ｅｔ ａｌ．，Ｊ．Ａｍ．Ｃｈｅｍ．Ｓｏｃ．，１０６，７７４８（１９８４）参照）元素分析の結果も以下に示すが、計算値とほぼ一致している。
これにより合成物はジヒドロキシシリコンフタロシアニンと確認された。

得られたジヒドロキシシリコンフタロシアニンのＣｕ−Ｋα線によるＸ線回折図（図３）では、２θに主たるピーク9.3 ゜を有し、その他11.1、13.4、20.0、22.5、23.9、27.4゜にそれぞれピークを有す本発明の結晶形を有するジヒドロキシシリコンフタロシアニンであることが確認された。
【００２４】
比較例１（従来技術１：J. B. Davision et al., Macromol., 1978, 11, 186 ）特開平１０−２１２２９１号公報 比較例１記載のジヒドロキシシリコンフタロシアニンのＩＲスペクトルを図４に、Ｘ線回折スペクトルを図５に示した。ＩＲスペクトルでは、ジヒドロキシシリコンフタロシアニン特有の吸収が１５１９、１０７０、８２９ｃｍ^-1に見られ、実施例１で製造したジヒドロキシシリコンフタロシアニンの１５１９、１０６８、８４０ｃｍ^-1の吸収に対しシフトしていることが結晶形の違いを示している。Ｘ線回折スペクトルは、２θが7.1 、9.3 、12.8、15.8、17.2、25.6、26.9゜にそれぞれピークを有し、本発明のジヒドロキシシリコンフタロシアニンの結晶とは明らかに異なるジヒドロキシシリコンフタロシアニンである。
【００２５】
比較例２ （従来技術２：特開平１０−２１２２９１）
特開平１０−２１２２９１号公報 実施例１記載のジヒドロキシシリコンフタロシアニンのＩＲスペクトルを図６に、Ｘ線回折スペクトルを図７に示した。ＩＲスペクトルでは、ジヒドロキシシリコンフタロシアニン特有の吸収が１５１９、１０６６、８３９ｃｍ^-1に見られ、実施例１で製造したジヒドロキシシリコンフタロシアニンの１５１９、１０６８、８４０ｃｍ^-1の吸収に対しシフトしていることが結晶形の違いを示している。Ｘ線回折スペクトルは、２θが9.2 、14.1、15.3、19.7、27.1゜にそれぞれピークを有し、本発明のジヒドロキシシリコンフタロシアニンの結晶とは明らかに異なるジヒドロキシシリコンフタロシアニンである。
【００２６】
「電子写真感光体の作成」
実施例２
実施例１で製造したジヒドロキシシリコンフタロシアニン0.4 ｇを4 −メトキシ−4 −メチル−２−ペンタノン、30ｇとともに、サンドグラインドミルで6 時間粉砕、微粒子化分散処理を行った。次に、ポリビニルブチラール（電気化学工業（株）製、デンカブチラール＃6000C ）0.1 ｇとフェノキシ樹脂（ユニオンカーバイド（株）製、UCAR）0.1 ｇの10％4 −メトキシ−4 −メチル−２−ペンタノン溶液と混合して分散液を調整した。この分散液をアルミニウム蒸着されたポリエステルフィルム上にバーコータにより乾燥後の膜厚が0.4 μｍとなるように電荷発生層を設けた。調液後の分散液中のジヒドロキシシリコンフタロシアニンのＸ線回折スペクトルを図８に示す。分散によりそれぞれのピークがブロード化しているが、調液前と比較し大きな変化はないことが確認できる。次にこの電荷発生層の上に、下記に示すヒドラゾン化合物5.6 ｇと
【００２７】
【化６】

【００２８】
下記に示すヒドラゾン化合物1.4 ｇ
【００２９】
【化７】

【００３０】
およびポリカーボネート樹脂（三菱化学ノバレックス７０３０Ａ）１０ｇをＴＨＦ６２ｇに溶解させた溶液をアプリケーターにより塗布し、乾燥後の膜厚が２０μｍとなるように電荷輸送層を設けた。
比較例３
実施例２において用いたジヒドロキシシリコンフタロシアニンに代えて、比較例１のジヒドロキシシリコンフタロシアニンを用いた他は実施例２
と同様にして電子写真感光体を作成した。
【００３１】
比較例４
実施例２において用いたジヒドロキシシリコンフタロシアニンに代えて、比較例２のジヒドロキシシリコンフタロシアニンを用いた他は実施例２
と同様にして電子写真感光体を作成した。
【００３２】
「評価」
得られた感光体を静電複写紙試験装置（川口電気製作所製、モデルEPA-8100) を用いて初期電気特性（帯電電位、暗減衰、半減露光量感度、残留電位）を評価した。評価法としては、暗所でコロナ電流が22 mA になるように設定した印加電圧でコロナ放電により感光体を負帯電させ（この時の表面電位を帯電電位とする）、2.4 秒後に780nm の単色光（1.0mW/cm² ）を10秒間連続的に露光し表面電位の減衰を測定した（露光10秒後の表面電位を残留電位とする）。暗減衰は帯電1 秒後に低下した電位とし、半減露光量感度は表面電位が-450V から-225V に減少するのに要した露光量（E1/2）で求めた。また上記と同条件の帯電と露光を２００００回繰り返した後の感光体の帯電電位を測定した。結果を表１に示す。
【００３３】
【表１】

【００３４】
表１より同じジヒドロキシシリコンフタロシアニンでも結晶形の違いで電気特性が著しく異なることがわかる。すなわち、比較例１の結晶形では帯電性が極めて悪く、実用上使用できない。また、第二の結晶形である比較例２の結晶形は帯電性、暗減衰、感度、残留電位ともに優れた特性を示すが、帯電と露光を２００００回繰り返した後の感光体の帯電電位の低下幅が大きい。これに対し、本発明の新規結晶形ジヒドロキシシリコンフタロシアニンは、帯電性、暗減衰、感度、残留電位に優れ、さらに帯電、露光を繰り返した場合の帯電性の低下が改善された耐刷性に優れた光導電材料である。
【００３５】
【発明の効果】
以上詳述したように、本発明は、従来にはない特定の結晶形を有するジヒドロキシシリコンフタロシアニン化合物を提供するものであり、さらに、このジヒドロキシシリコンフタロシアニン化合物を感光層として用いた電子写真感光体は、表１からも明らかなように、感度特性、電荷保持性、耐刷性に優れており、プリンター、ファクシミリ、複写機に有効に用いることができるものである。
【図面の簡単な説明】
【図１】実施例１で得られたジヒドロキシシリコンフタロシアニン化合物のマススペクトル図を示す。
【図２】実施例１で得られたジヒドロキシシリコンフタロシアニン化合物のＩＲスペクトル図を示す。
【図３】実施例１で得られたジヒドロキシシリコンフタロシアニン化合物のＸ線回折図を示す。
【図４】比較例１のジヒドロキシシリコンフタロシアニン化合物のＩＲスペクトル図を示す。
【図５】比較例１のジヒドロキシシリコンフタロシアニン化合物のＸ線回折図を示す。
【図６】比較例２のジヒドロキシシリコンフタロシアニン化合物のＩＲスペクトル図を示す。
【図７】比較例２のジヒドロキシシリコンフタロシアニン化合物のＸ線回折図を示す。
【図８】実施例２で得られた調液後のジヒドロキシシリコンフタロシアニン化合物のＸ線回折図を示す。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a dihydroxysilicon phthalocyanine compound having a novel crystal form. Furthermore, the present invention relates to an electrophotographic photosensitive member containing this silicon phthalocyanine compound in a photosensitive layer, particularly to an electrophotographic photosensitive member that can be effectively used in printers, facsimiles, and copying machines.
[0002]
[Prior art]
Conventionally, phthalocyanine compounds exhibit good photoconductivity and are used, for example, in electrophotographic photoreceptors. In recent years, laser printers that use laser light as the light source instead of conventional white light and have the advantages of high speed, high image quality, and non-impact have become widespread. It is. In particular, a method using a semiconductor laser as a light source, which has made remarkable progress in recent years, is the mainstream, and there is a strong demand for a photoreceptor having high sensitivity to long wavelength light of around 780 nm which is the light source wavelength. Under such circumstances, phthalocyanine compounds can be synthesized (1) relatively easily, (2) have an absorption peak in the long wavelength region of 600 nm or more, and (3) spectral sensitivity varies depending on the central metal and crystal form. Research and development has been carried out energetically because of the announcement of several laser diodes that exhibit high sensitivity in the wavelength range.
[0003]
Phthalocyanine compounds not only have different absorption spectra and photoconductivity depending on the type of central metal, but also have different physical properties depending on the crystal form. It is known to have a significant effect. For example, regarding copper phthalocyanine, crystal forms such as α, γ, ε, π, χ, τ, ρ, and δ are known in addition to the stable β form. It is known that they can be transferred to each other by sulfuric acid treatment, organic solvent treatment, heat treatment, etc. (see Organic Electronics Materials Series 6 Phthalocyanine). Japanese Patent Laid-Open No. 50-38543 describes that the ε form exhibits the highest sensitivity in the comparison of the α, β, γ, and ε forms of the crystal form and electrophotographic characteristics of copper phthalocyanine. .
[0004]
On the other hand, as for hydroxymetal phthalocyanine, an electrophotographic photoreceptor using dihydroxygermanium phthalocyanine, dihydroxytin phthalocyanine, and dihydroxysilicon phthalocyanine is described in US Pat. No. 4,557,989. Japanese Patent Laid-Open No. 6-214415 also has a report on an electrophotographic photosensitive member using hydroxymetal phthalocyanine (Al, Ga, In, Si, Ge, Sn). One crystal form of dihydroxysilicon phthalocyanine has been reported. Presenting. In addition to this, Japanese Patent Application Laid-Open No. 10-212291 reports a novel crystalline dihydroxysilicon phthalocyanine having more excellent characteristics as a photoconductive material.
[0005]
[Problems to be solved by the invention]
However, dihydroxysilicon phthalocyanines having the crystal forms of the above-mentioned U.S. Pat. No. 4,557,989 and JP-A-6-214415 have problems with respect to their dispersibility, dispersibility, and storage stability. Also, sufficient chargeability cannot be obtained in electrophotographic characteristics. From Japanese Patent Application Laid-Open No. 10-212291, it has been found that even a novel crystalline dihydroxysilicon phthalocyanine having excellent characteristics as a photoconductive material tends to have insufficient chargeability when charging and exposure are repeated. Other phthalocyanine compounds that have been proposed in the past are still not fully satisfactory in terms of photosensitivity and durability when used as photoconductive materials, and the development of new crystalline phthalocyanine compounds has not been achieved. It is strongly desired. Therefore, the present invention has been made in view of the above-described situation in the prior art, and the object thereof is a phthalocyanine having a novel crystal form excellent in photosensitivity, durability, and environmental characteristics as a photoconductive material. It is an object to provide a compound and an electrophotographic photosensitive member having high sensitivity, high durability, and high stability.
[0006]
[Means for Solving the Problems]
As a result of thorough examination on the relationship between the crystal form of the phthalocyanine compound and the electrophotographic characteristics, the present invention has a Bragg angle 2θ (± 0.3 °) 9.3, 13.4, 20.0, It has been found that a novel crystalline dihydroxysilicon phthalocyanine compound having peaks at 23.9 and 27.4 ° is excellent in photosensitivity, durability and environmental characteristics as a photoconductive material. That is, the present invention provides an X-ray diffraction pattern by Cu-K [alpha line at Bragg angles 2 [Theta] (± 0.3 °) a novel crystalline form dihydroxysilicon phthalocyanine compound having 9.3,13.4,20.0,23.9,27.4 ° peak crystallization and the dihydroxy The present invention relates to an electrophotographic photosensitive member containing a silicon phthalocyanine compound crystal .
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail.
The dihydroxysilicon phthalocyanine compound of the present invention has a completely different crystal form from the previously known dihydroxysilicon phthalocyanine, and has a Bragg angle 2θ (± 0.3 °) in the X-ray diffraction pattern by Cu-Kα ray. ) There are peaks at 9.3, 13.4, 20.0, 23.9 and 27.4 °. Other peaks such as 11.1, 15.6, 17.9, and 22.5 ° also have peaks, but there are subtle differences in manufacturing conditions, differences in crystal orientation, ratio of peak intensity and position due to X-ray diffraction measurement methods, etc. Etc. may vary somewhat. As described above, the dihydroxysilicon phthalocyanine compound according to the present invention exhibits a novel X-ray diffraction pattern that has not existed in the past.
[0008]
[Chemical 1]

[0009]
The dihydroxysilicon phthalocyanine compound may contain an alkyl, alkoxy, or halogen atom substituted substrate.
The X-ray diffraction spectrum is measured under the following conditions.
X-ray Cu Kα1
Voltage 40KV
Current 30mA
Start angle 3.00deg
Stop angle 40.00deg
Step angle 0.05deg
Measurement time 0.50sec / step
[0010]
The novel crystalline dihydroxysilicon phthalocyanine compound of the present invention can be produced, for example, as follows. A dialkoxysilicon phthalocyanine compound is synthesized by a known method such as JP-A-10-237339. This dialkoxysilicon phthalocyanine is prepared in the same manner as in JP-A-10-237340, that is, in the presence of water, N-methylpyrrolidone, ethylene carbonate, propylene carbonate, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl When hydrolyzed by heating with a polar solvent such as sulfoxide or sulfolane, a novel crystalline dihydroxysilicon phthalocyanine compound is produced simultaneously with the hydrolysis. At this time, depending on the structure and production conditions of dialkoxysilicon phthalocyanine, a dihydroxysilicon phthalocyanine compound having a known crystal form is obtained. For example, dialkoxysilicon phthalocyanine having an alkoxy group having 5 or more carbon atoms is used as a raw material, and hydrolysis conditions are selected. Thus, the crystalline dihydroxysilicon phthalocyanine of the present invention can be obtained.
[0011]
The novel crystalline dihydroxysilicon phthalocyanine compound thus treated can be obtained by isolation, washing and drying from the treatment solvent.
Next, an electrophotographic photoreceptor using the novel crystalline dihydroxysilicon phthalocyanine compound as a photoconductive material in the photosensitive layer will be described. In the electrophotographic photoreceptor of the present invention, the photosensitive layer coated on the conductive support may have a single-layer structure or a laminated structure comprising a charge generation layer and a charge transport layer. Also good. Further, an undercoat layer may be formed between the conductive support and the photosensitive layer, and a surface protective layer may be provided on the photosensitive layer in the single layer structure, or on the charge transport layer in the laminated structure. good.
[0012]
Any conductive support may be used as long as it can be used as an electrophotographic photosensitive member. Specific examples include metal drums such as aluminum, copper, and nickel, sheets, laminates of these metal foils, and vapor-deposited materials. Furthermore, a plastic film, a plastic drum, paper, and the like obtained by applying a conductive material such as metal powder, carbon black, copper iodide, and a polymer electrolyte together with a suitable binder to conduct a conductive treatment may be used. Also, there are plastic sheets and drums containing conductive materials such as metal powder, carbon black, and carbon fiber, and plastic films having conductive metal oxide layers such as tin oxide and indium oxide on the surface. Can be mentioned.
[0013]
The undercoat layer is effective for preventing unnecessary charge injection from the conductive support, and has the effect of increasing the charge of the photosensitive layer. Furthermore, it also has the effect of increasing the adhesion between the photosensitive layer and the conductive support. As the material constituting the undercoat layer, aluminum anodized film, aluminum oxide, aluminum hydroxide, titanium oxide, surface treated titanium oxide and other inorganic materials, polyvinyl alcohol, casein, polyvinylpyrrolidone, polyacrylic acid, celluloses, gelatin, Examples thereof include organic layers such as starches, polyurethanes, polyimides, polyamides, etc., organic zirconium compounds, titanium chelate compounds, titanium alkoxide compounds, organic titanium compounds, silane coupling agents, and the like. The thickness of the undercoat layer is preferably in the range of 0.1 to 20 μm, and most effectively used in the range of 0.1 to 10 μm.
[0014]
When the electrophotographic photosensitive member has a laminated structure, the charge generation layer is composed of the dihydroxysilicon phthalocyanine compound and a binder resin. In the present invention, a charge generating material other than the dihydroxysilicon phthalocyanine compound may be used in combination. Examples of the charge generating material that can be used in combination include dihydroxysilicon phthalocyanine, dialkoxysilicon phthalocyanine, titanyl phthalocyanine, gallium phthalocyanine, indium phthalocyanine, and metal-free phthalocyanine which are not in the crystalline form of the present invention. In addition, phthalocyanine compounds, azo compounds, anthraquinone compounds, perylene compounds, polycyclic quinone compounds, squalic acid methine compounds, and the like other than those described above are exemplified, but the invention is not limited thereto. The binder resin can be selected from a wide range of insulating resins. Preferred binder resins include polymers and copolymers of vinyl compounds such as styrene, vinyl acetate, vinyl chloride, vinylidene chloride, acrylic acid ester, methacrylic acid ester, acrylamide, acrylonitrile, vinyl alcohol, ethyl vinyl ether, vinyl pyridine, Examples include, but are not limited to, phenoxy resin, polysulfone, polyvinyl acetal, polyvinyl butyral, polycarbonate, polyester, polyamide, polyurethane, cellulose ester, cellulose ether, epoxy resin, silicon resin, alkyd resin, polyarylate, and the like. .
[0015]
The charge generation layer is formed by dispersing the dihydroxysilicon phthalocyanine compound in a solution obtained by dissolving the binder resin in an organic solvent to prepare a coating solution, coating the conductive solution on a conductive support, and drying the coating solution. Can do. During the dispersion treatment, there is no problem even if part of the solution is dissolved. As a method for the dispersion treatment, a known method such as a ball mill, a sand grind mill, a planetary mill, a roll mill, or a paint shaker can be used. In that case, the ratio of the dihydroxysilicon phthalocyanine compound and the binder resin is not particularly limited, but is 1 to 1000 parts by weight, preferably 10 to 400 parts by weight of the binder resin with respect to 100 parts by weight of the dihydroxysilicon phthalocyanine compound. It is a range. When the ratio of the dihydroxysilicon phthalocyanine compound is too high, the stability of the coating solution is lowered, and when it is too low, the residual potential is increased, so that the composition ratio is in the above range. Organic solvents used include ethers such as tetrahydrofuran, dioxane and ethylene glycol monomethyl ether, ketones such as acetone, methyl ethyl ketone and cyclohexanone, aromatic hydrocarbons such as toluene and xylene, halogenated aromatics such as monochlorobenzene and dichlorobenzene. Group hydrocarbons, halogenated aliphatic hydrocarbons such as methylene chloride, chloroform, carbon tetrachloride, dichloroethane and trichloroethane, alcohols such as methanol, ethanol and isopropanol, esters such as methyl acetate and ethyl acetate, N, N-dimethyl Examples thereof include amides such as formamide and N, N-dimethylacetamide, and sulfoxides such as dimethyl sulfoxide. The coating liquid can be applied by coating methods such as dip coating, spray coating, spinner coating, bead coating, wire bar coating, blade coating, roller coating, curtain coating, ring coating, etc. . Drying after application can be carried out at a temperature of 25 to 250 ° C. for 5 minutes to 3 hours in a static state or under air blowing. The film thickness of the charge generation layer formed is usually in the range of 0.1 to 5 μm.
[0016]
The charge transport layer is composed of a charge transport material, a binder resin, and optionally additives such as an antioxidant. The charge transport material is generally classified into two types, that is, an electron transport material and a hole transport material. Any of the electrophotographic photoreceptors of the present invention can be used, and a mixture thereof can also be used. Examples of electron transport materials include electron-withdrawing compounds having an electron-withdrawing group such as a nitro group, a cyano group, and an ester group, such as 2,4,7-trinitrofluorenone and 2,4,5,7-tetranitrofluorenone. And quinones such as nitrated fluorenone, tetracyanoquinodimethane, and diphenoquinone. In addition, as a hole transport material, an electron-donating organic photoelectric compound, for example, carbazole, indole, imidazole, oxazole, thiazole, oxadiazole, pyrazole, pyrazoline, thiadiazole, benzoxazole , Benzothiazole, naphthothiazole, etc., diarylalkane derivatives such as diphenylmethane, triarylalkane derivatives such as triphenylmethane, triarylamine derivatives such as triphenylamine, phenylenediamine derivatives, N-phenylcarbazole Derivatives, diarylethylene derivatives such as stilbene, hydrazone derivatives, substituted amino groups such as dialkylamino groups and diphenylamino groups, or electron donations such as alkoxy groups and alkyl groups , Or their electron donating group is an aromatic ring group substituted can be cited a compound having a large electron-donating substituted. Moreover, the polymer which has the group which consists of said compounds in a principal chain or a side chain, such as polyvinyl carbazole, polyglycidyl carbazole, polyvinyl pyrene, polyvinyl phenyl anthracene, polyvinyl acridine, pyrene formaldehyde resin, is also mentioned. More specifically, the following compounds may be mentioned.
[0017]
[Chemical formula 2]

[0018]
[Chemical 3]

[0019]
[Formula 4]

[0020]
[Chemical formula 5]

[0021]
Further, as the binder resin, the same insulating resin as that used for the charge generation layer described above can be used. The ratio of the charge transport material and the binder resin is not particularly limited, but is in the range of 20 to 3000 parts by weight, preferably 50 to 1000 parts by weight of the binder resin with respect to 100 parts by weight of the charge transport material. The charge transport layer is prepared by adjusting the coating solution using the same organic solvent as that used for the charge generation layer, and then applying the charge transport material and the binder resin by the same method as described above, and drying. Can be formed. The thickness of the charge transport layer is usually in the range of 5 to 50 μm.
[0022]
When the electrophotographic photoreceptor has a single-layer structure, the photosensitive layer is composed of the dihydroxysilicon phthalocyanine compound, a charge transport material, and a binder resin. At this time, a charge generating material other than the dihydroxysilicon phthalocyanine compound of the present invention may be used in combination as in the case of the multilayer type photoreceptor. The same charge transport material and binder resin as those used in the previous period are used. The photosensitive layer may contain various additives such as an antioxidant and a sensitizer as necessary. The ratio of the dihydroxysilicon phthalocyanine compound and the charge transport material to the binder resin is 2 to 300 parts by weight of the binder resin to 10 parts by weight of the dihydroxysilicon phthalocyanine compound and the charge transport material, and the ratio of the dihydroxysilicon phthalocyanine compound and the charge transport material. The proportion is suitably in the range of 0.01 to 100 parts by weight of the charge transport material with respect to 1 part by weight of the dihydroxysilicon phthalocyanine compound. And after adjusting a coating liquid like the above, a photosensitive layer is obtained by apply | coating and drying.
[0023]
【Example】
EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist.
Example 1
"Synthesis of dihydroxysilicon phthalocyanine"
10 g of bis (3-methoxy-3-methylbutanoxy) silicon phthalocyanine synthesized by a known method was added to 5 g of water and 95 g of N-methylpyrrolidone (95% NMP aqueous solution) and reacted at 148 ° C. for 2 hours. The product was filtered hot and washed with NMP and methanol in this order. Subsequently, after stirring at room temperature in 100 ml of methanol, the crystals were filtered off and dried to obtain 6.8 g of dihydroxysilicon phthalocyanine. The structural analysis was performed by mass spectrum (negative measurement), IR (KBr method), and elemental analysis. FIG. 1 shows a mass spectrum of dihydroxysilicon phthalocyanine, and FIG. 2 shows an IR spectrum. In the mass spectrum, a peak of dihydroxysilicon phthalocyanine was confirmed at m / z: 574. In the IR spectrum, absorptions peculiar to dihydroxysilicon phthalocyanine were observed at 1519, 1068, and 840 cm −1 (see E. Ciliberto et al., J. Am. Chem. Soc., 106, 7748 (1984)). As shown below, it is almost the same as the calculated value.
This confirmed that the composite was dihydroxysilicon phthalocyanine.

In the X-ray diffraction pattern of Cu-Kα ray of the obtained dihydroxysilicon phthalocyanine (Fig. 3), it has a main peak of 9.3 ° at 2θ and other peaks at 11.1, 13.4, 20.0, 22.5, 23.9 and 27.4 °, respectively. This was confirmed to be dihydroxysilicon phthalocyanine having the crystal form of the present invention.
[0024]
Comparative Example 1 (Prior Art 1: JB Davision et al., Macromol., 1978, 11, 186) JP 10-212291 A IR spectrum of dihydroxysilicon phthalocyanine described in Comparative Example 1 is shown in FIG. Is shown in FIG. The IR spectrum, dihydroxysilicon phthalocyanine specific absorption was observed at 1519,1070,829Cm ^-1, crystals that are shifted with respect to the absorption of 1519,1068,840Cm ^-1 dihydroxy silicon phthalocyanine produced in Example 1 It shows the difference in shape. The X-ray diffraction spectrum is dihydroxysilicon phthalocyanine which has peaks at 2θ of 7.1, 9.3, 12.8, 15.8, 17.2, 25.6 and 26.9 °, which is clearly different from the dihydroxysilicon phthalocyanine crystal of the present invention.
[0025]
Comparative Example 2 (Prior Art 2: JP-A-10-212291)
The IR spectrum of dihydroxysilicon phthalocyanine described in Example 1 is shown in FIG. 6 and the X-ray diffraction spectrum is shown in FIG. The IR spectrum, dihydroxysilicon phthalocyanine specific absorption was observed at 1519,1066,839Cm ^-1, crystals that have shifted to the absorption of 1519,1068,840Cm ^-1 dihydroxy silicon phthalocyanine produced in Example 1 It shows the difference in shape. The X-ray diffraction spectrum is dihydroxysilicon phthalocyanine which has peaks at 2θ of 9.2, 14.1, 15.3, 19.7 and 27.1 °, respectively, and is clearly different from the dihydroxysilicon phthalocyanine crystal of the present invention.
[0026]
"Creation of electrophotographic photoreceptor"
Example 2
0.4 g of dihydroxysilicon phthalocyanine produced in Example 1 was pulverized in a sand grind mill for 6 hours together with 4-methoxy-4-methyl-2-pentanone and 30 g, followed by fine particle dispersion treatment. Next, 10% 4-methoxy-4-methyl-2-pentanone of 0.1 g of polyvinyl butyral (Denka Butyral # 6000C, manufactured by Denki Kagaku Kogyo Co., Ltd.) and 0.1 g of phenoxy resin (manufactured by Union Carbide Co., Ltd., UCAR) The dispersion was prepared by mixing with the solution. A charge generation layer was provided on a polyester film on which this dispersion was vapor-deposited so that the film thickness after drying by a bar coater was 0.4 μm. FIG. 8 shows an X-ray diffraction spectrum of dihydroxysilicon phthalocyanine in the dispersion after preparation. Although each peak is broadened by dispersion, it can be confirmed that there is no significant change compared to before preparation. Next, on this charge generation layer, 5.6 g of the hydrazone compound shown below and
[Chemical 6]

[0028]
The following hydrazone compounds 1.4 g
[0029]
[Chemical 7]

[0030]
A solution in which 10 g of polycarbonate resin (Mitsubishi Chemical Novalex 7030A) was dissolved in 62 g of THF was applied by an applicator, and a charge transport layer was provided so that the film thickness after drying was 20 μm.
Comparative Example 3
Example 2 except that the dihydroxysilicon phthalocyanine of Comparative Example 1 was used instead of the dihydroxysilicon phthalocyanine used in Example 2.
An electrophotographic photoreceptor was prepared in the same manner as described above.
[0031]
Comparative Example 4
Example 2 except that the dihydroxysilicon phthalocyanine of Comparative Example 2 was used instead of the dihydroxysilicon phthalocyanine used in Example 2.
An electrophotographic photoreceptor was prepared in the same manner as described above.
[0032]
"Evaluation"
The obtained photoreceptor was evaluated for initial electrical characteristics (charging potential, dark decay, half-exposure sensitivity, residual potential) using an electrostatic copying paper testing apparatus (model EPA-8100, manufactured by Kawaguchi Electric Manufacturing Co., Ltd.). As an evaluation method, the photoconductor is negatively charged by corona discharge with an applied voltage set so that the corona current is 22 mA in a dark place (the surface potential at this time is set as the charging potential), and after 2.8 nm, a single color of 780 nm Light (1.0 mW / cm ² ) was continuously exposed for 10 seconds, and the decay of the surface potential was measured (the surface potential after 10 seconds of exposure was taken as the residual potential). The dark decay was the potential decreased after 1 second of charging, and the half-exposure sensitivity was determined by the exposure (E1 / 2) required for the surface potential to decrease from -450V to -225V. Further, the charging potential of the photoconductor after repeating 20000 times of charging and exposure under the same conditions as described above was measured. The results are shown in Table 1.
[0033]
[Table 1]

[0034]
From Table 1, it can be seen that even in the same dihydroxysilicon phthalocyanine, the electrical characteristics are remarkably different depending on the crystal form. That is, the crystalline form of Comparative Example 1 has extremely poor chargeability and cannot be used practically. The crystal form of Comparative Example 2, which is the second crystal form, exhibits excellent characteristics in terms of chargeability, dark decay, sensitivity, and residual potential, but the charge potential of the photoreceptor after 20000 times of charging and exposure is shown. The decline is large. In contrast, the novel crystalline dihydroxysilicon phthalocyanine of the present invention is excellent in chargeability, dark decay, sensitivity, and residual potential, and further has excellent printing durability in which a decrease in chargeability when repeated charging and exposure is improved. A photoconductive material.
[0035]
【The invention's effect】
As described above in detail, the present invention provides a dihydroxysilicon phthalocyanine compound having a specific crystal form that has not been heretofore known. Further, an electrophotographic photoreceptor using the dihydroxysilicon phthalocyanine compound as a photosensitive layer is provided. As is apparent from Table 1, it has excellent sensitivity characteristics, charge retention, and printing durability, and can be used effectively in printers, facsimiles, and copiers.
[Brief description of the drawings]
1 shows a mass spectrum diagram of a dihydroxysilicon phthalocyanine compound obtained in Example 1. FIG.
2 shows an IR spectrum of the dihydroxysilicon phthalocyanine compound obtained in Example 1. FIG.
3 shows an X-ray diffraction pattern of the dihydroxysilicon phthalocyanine compound obtained in Example 1. FIG.
4 shows an IR spectrum of the dihydroxysilicon phthalocyanine compound of Comparative Example 1. FIG.
5 shows an X-ray diffraction pattern of the dihydroxysilicon phthalocyanine compound of Comparative Example 1. FIG.
6 shows an IR spectrum of the dihydroxysilicon phthalocyanine compound of Comparative Example 2. FIG.
7 shows an X-ray diffraction pattern of a dihydroxysilicon phthalocyanine compound of Comparative Example 2. FIG.
FIG. 8 shows an X-ray diffraction pattern of a dihydroxysilicon phthalocyanine compound after preparation obtained in Example 2.

Claims (2)

Dihydroxysilicon phthalocyanine compound crystal having peaks at Bragg angles 2θ (± 0.3 °) 9.3, 13.4, 20.0, 23.9, and 27.4 ° in an X-ray diffraction pattern by Cu-Kα rays. An electrophotographic photosensitive member using a photosensitive layer containing the silicon phthalocyanine compound crystal according to claim 1 on a conductive support.

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