JP3763938B2 - Conductive member and electrophotographic apparatus - Google Patents

Description

【００２０】
（式中、Ｒ¹ は炭素数１〜３０のアルキル基，炭素数６〜３０のアリール基又は炭素数７〜３０のアラルキル基、Ｒ² ，Ｒ³ 及びＲ⁴ は、それぞれ独立に炭素数１〜６のアルキル基を示し、Ｘ^n-はｎ価の陰イオンを示す。なお、ｎは１〜６の整数である。）
で表される化合物を挙げることができる。
上記一般式（Ｉ）において、Ｒ¹ のうち炭素数１〜３０のアルキル基は直鎖状，分岐状，環状のいずれであってもよく、その例としてはメチル基，エチル基，プロピル基，ブチル基，ヘキシル基，オクチル基，ノニル基，デシル基，ドデシル基，テトラデシル基，ヘキサデシル基，オクタデシル基，エイコシル基，シクロペンチル基，シクロヘキシル基，シクロオクチル基，シクロドデシル基などが挙げられる。また炭素数６〜３０のアリール基としては、例えばフェニル基，ナフチル基などが挙げられ、炭素数７〜３０のアラルキル基としては、例えばベンジル基，フェネチル基，ナフチルメチル基などが挙げられる。なお、上記アリール基及びアラルキル基は、炭素環上に低級アルキル基，低級アルコキシ基，ハロゲンなどの適当な不活性基が導入されていてもよい。
【００２１】
また、Ｒ² ，Ｒ³ 及びＲ⁴ で表される炭素数１〜６のアルキル基は直鎖状，分岐状，環状のいずれであってもよく、その例としてはメチル基，エチル基．プロピル基，ブチル基，ペンチル基，ヘキシル基，シクロペンチル基，シクロヘキシル基などが挙げられる。Ｒ² ，Ｒ³ 及びＲ⁴ はたがいに同一であってよく、異なっていてもよい。
さらに、Ｘ^n-としては、例えばＦ^- ，Ｃｌ^- ，Ｂｒ^- ，Ｉ^- のハロゲンイオン、ＮＯ₃ ^- ，ＣＯ₃ ^2-，ＳＯ₄ ^2- ，ＣｌＯ₄ ^- ，ＢＦ₄ ^- などの無機酸イオン、酢酸根（ＣＨ₃ ＣＯＯ^- ），安息香酸根，マロン酸根，シュウ酸根，酒石酸根，クエン酸根，リンゴ酸根，コハク酸根，マレイン酸根，フマル酸根，フタル酸根，イソフタル酸根，テレフタル酸根，トリメリット酸根，トリメシン酸根，トリカルバリン酸根などの有機酸（カルボン酸）イオン、その他、ＣＨ₃ ＯＳＯ₃ ^- ，Ｃ₂ Ｈ₅ ＯＳＯ₃ ^- 等で代表される式 ＲＯＳＯ₃ ^- （Ｒは炭素数１〜１０のアルキル基を示す）で表されるアルキル硫酸イオン、さらにはｐ−トルエンスルホン酸根などの含硫黄有機酸イオンなどが挙げられる。
このＸ^n-については、特にカルボン酸イオンあるいはアルキル硫酸イオンが好ましい。
【００２２】
前記一般式（Ｉ）で表される第四級アンモニウム塩の例としては、各種のものがあるが、良好な電気抵抗の環境安定性及び連続通電時の抵抗安定性などが得られる点から、アルキル硫酸の第四級アンモニウム塩及びカルボン酸の第四級アンモニウム塩が好適である。具体的には、アルキル硫酸の第四級アンモニウム塩としては、変性脂肪族ジメチルエチルアンモニウムエトサルフェート，テトラアルキルアンモニウムエトサルフェート，ラウロイルアミノプロピルジメチルエチルアンモニウムエトサルフェート等の第四級アンモニウム塩が用いられ、カルボン酸の第四級アンモニウム塩としては、マレイン酸ベンジルトリメチルアンモニウム，マレイン酸ベンジルトリエチルアンモニウム，フマル酸ベンジルトリメチルアンモニウム，フマル酸ベンジルトリエチルアンモニウム，マロン酸ベンジルトリメチルアンモニウム，マロン酸ベンジルトリエチルアンモニウム，シュウ酸ベンジルトリメチルアンモニウム，シュウ酸ベンジルトリエチルアンモニウム，リンゴ酸ベンジルトリメチルアンモニウム，リンゴ酸ベンジルトリエチルアンモニウム，酒石酸ベンジルトリメチルアンモニウム，酒石酸ベンジルトリエチルアンモニウム，クエン酸ベンジルトリメチルアンモニウム，クエン酸ベンジルトリエチルアンモニウム，フタル酸ベンジルトリメチルアンモニウム，フタル酸ベンジルトリエチルアンモニウム，イソフタル酸ベンジルトリメチルアンモニウム，イソフタル酸ベンジルトリエチルアンモニウム，テレフタル酸ベンジルトリメチルアンモニウム，テレフタル酸ベンジルトリエチルアンモニウム，トリメリット酸ベンジルトリメチルアンモニウム，トリメリット酸ベンジルトリエチルアンモニウム，マレイン酸テトラメチルアンモニウム，マレイン酸テトラブチルアンモニウム，フマル酸テトラメチルアンモニウム，フマル酸テトラブチルアンモニウム，マロン酸テトラメチルアンモニウム，マロン酸テトラブチルアンモニウム，シュウ酸テトラメチルアンモニウム，シュウ酸テトラブチルアンモニウム，リンゴ酸テトラメチルアンモニウム，リンゴ酸テトラブチルアンモニウム，酒石酸テトラメチルアンモニウム，酒石酸テトラブチルアンモニウム，クエン酸テトラメチルアンモニウム，クエン酸テトラブチルアンモニウム，フタル酸テトラメチルアンモニウム，フタル酸テトラブチルアンモニウム，イソフタル酸テトラメチルアンモニウム，イソフタル酸テトラブチルアンモニウム，テレフタル酸テトラメチルアンモニウム，テレフタル酸テトラブチルアンモニウム，トリメリット酸テトラメチルアンモニウム，トリメリット酸テトラブチルアンモニウム，ジ硬化牛脂アルキルジメチルアンモニウムアセテート等の第四級アンモニウム塩が用いられる。
【００２３】
この第四級アンモニウム塩は一種用いてもよく、二種以上を組み合わせて用いてもよい。また、その配合量は、特に制限はなく、各種の状況に応じて適宜選定すればよいが、例えば得られる導電性材料の体積固有抵抗値が中抵抗領域、特に印加電圧１０００Ｖで１×１０⁵ 〜１×１０¹⁰Ωｃｍ程度になるようにするには、前記（Ａ）成分のポリウレタンフォーム又はポリウレタンエラストマー１００重量部に対し、0.００１〜５重量部が好ましく、特に0.０５〜１重量部の範囲がより好ましい。
この第四級アンモニウム塩を前記（Ａ）成分のポリウレタンフォーム又はポリウレタンエラストマーに配合する方法については、特に制限はないが、（Ａ）成分のポリウレタンフォームやポリウレタンエラストマーの製造時に、反応系に添加するのが有利である。この際、第四級アンモニウム塩の形で添加してもよく、また第四級アンモニウムヒドロキシドと多官能酸とを別々に添加してもよい。第四級アンモニウム塩や第四級アンモニウムヒドロキシドの形で添加する場合には、エーテル，アルコール，エステル，ラクトン，カーボネートなどの溶剤に溶解して添加するのが好ましい。
【００２４】
また、導電性付与剤として、この（Ｂ）成分の第四級アンモニウム塩とともに、本発明の目的が損なわれない範囲で、所望により、従来用いられている過塩素酸ナトリウム，過塩素酸カリウム，過塩素酸カルシウムなどの無機塩や、カーボンブラック，金属粉，金属酸化物粉などの導電性フィラーを併用してもよい。
次に、本発明に用いられる導電性材料の製造方法については、特に制限はなく、また常法によればよいが、その一例を示せば次の通りである。
まず、前記のポリイソシアネート成分，ポリオール成分，鎖延長剤，第四級アンモニウム塩及び所望により用いられる他の導電性付与剤，触媒，補強剤，着色剤，整泡剤などを均質に混合したのち、加熱して反応硬化させることにより、ポリウレタンエラストマー中に導電性付与剤を含有してなる導電性材料が得られる。また、ポリオール成分をポリイソシアネート成分で予めイソシアネート化しておき、このものと、鎖延長剤，第四級アンモニウム塩及び所望により用いられる他の導電性付与剤，触媒，補強剤，着色剤，整泡剤などを均質に混合したのち、加熱して反応硬化させてもよい。
【００２５】
また、加熱して反応硬化させる際に、従来公知の方法により、発泡させることにより、ポリウレタンフォーム中に導電性付与剤を含有してなる導電性材料が得られる。本発明では得られる導電性材料は、フォーム体であることが好ましい。ここで、発泡方法については特に制限はなく、発泡剤を用いる方法、機械的な攪拌により気泡を混入する方法など、いずれの方法も用いることができる。なお発泡倍率は、適宜定めればよく、特に制限はない。
なお、このポリウレタンフォーム又はポリウレタンエラストマーは、耐熱性，耐薬品性，機械強度などを向上させる目的で、所望により架橋することもできる。
【００２６】
このようにして得られる導電性材料は、製造の際の条件により所望の体積固有抵抗値を有するものとなり、特に印加電圧１０００Ｖにおける体積固有抵抗値が、通常１×１０⁶ 〜１×１０¹¹Ωｃｍの範囲にあって、電気抵抗の位置ばらつきが少ない。しかも、電気抵抗の印加電圧依存性が小さいと同時に、連続通電の際の電気抵抗の変動幅及び温度や湿度などの環境変化による電気抵抗の変動が小さい。
本発明の導電性弾性部材は、中抵抗領域、特に１ＭΩ〜１００ＧΩの中抵抗領域で安定な抵抗値を示し、電子写真用導電性部材、具体的には電子写真装置における転写ローラ，現像ローラなどとして好適に用いられる。
本発明の導電性弾性部材を製造する方法は特に制限なく、種々の公知の方法によればよい。例えば鉄にメッキを施したもの又はステンレス鋼などの芯金を前記導電性材料で被覆し、用途によりさらにその外側を導電性，半導電性，絶縁性塗料により塗装することによって、１ＭΩ〜１００ＧΩの中抵抗領域で安定な抵抗値を示す本発明の導電性部材が得られる。なお、本発明の導電性部材の形状は特に限定されず、用途に応じて定めればよいが、例えばローラ状，プレート状，四角ブロック状，球状，ブラシ状などが挙げられるが、通常はローラ状あるいはプレート状である。
【００２７】
次に、本発明の導電性弾性部材を電子写真複写機の転写ローラとして用いた例について説明する。
図１は、本発明の導電性弾性部材を用いた電子写真複写機の転写装置の一例を示す説明図であって、芯金（図示せず）を具備した本発明の導電性弾性部材からなる導電性ローラ（転写ローラ）１を、感光体ドラムなどのトナー像担持体２に紙などの転写材４を介して当接させ、該導電性ローラ１とトナー像担持体２との間に、電源３により電圧を印加し、トナー像担持体と導電性ローラ間に電界を発生させることによって、トナー像担持体２上のトナーを転写材４に転写するものである。
本発明の導電性弾性部材を複写機などの電子写真装置に組み込む場合は、静電画像現像部，トナーなどの現像剤転写部などに応用される。
【００２８】
【実施例】
以下、実施例、比較例を示して本発明を具体的に説明するが、本発明は下記実施例に限定されるものではない。
実施例１
グリセリンにプロピレンオキサイドとエチレンオキサイドを付加し、分子量５０００であるポリエーテルポリオール１００重量部、ジフェニルメタンジイソシアネートとカルボジイミド変性ジフェニルメタンジイソシアネートとグリコール変性ジフェニルメタンジイソシアネートの混合物１6.６重量部、反応性シリコーン系界面活性剤４重量部、ジブチルチンジラウレート0.０１重量部、シュウ酸ベンジルトリメチルアンモニウム0.３重量部をミキサーで混合し、その混合物で直径６ｍｍの金属製シャフトを中心に配設した直径１6.５ｍｍで、長さ２１５ｍｍのウレタンフォーム転写ローラを作製した。
【００２９】
ついで上記転写ローラを厚さ５ｍｍのアルミニウム板の上に載せ、ローラの両端を各々５００ｇの力で圧接しながら芯金と抵抗測定器の銅板との間の電気抵抗を測定した。測定時の温度、湿度は各々２０℃，５０％であった。電気抵抗は印加電圧が１０００Ｖの時2.０×１０⁸ Ωであった。また測定時の温度、湿度が各々３2.５℃，８５％では、印加電圧１０００Ｖで電気抵抗は5.２×１０⁷ Ω、１５℃，１０％では、印加電圧１０００Ｖで1.７×１０⁹ Ωであった。
【００３０】
さらに上記転写ローラを図１に示す電子写真装置に組み込んだ。温度、湿度が各々１５℃，１０％の環境でグレースケール、黒ベタ、白ベタ画像を印刷させたところ良好な画像が得られ、さらに温度、湿度が各々３2.５℃，８５％の環境でグレースケール、黒ベタ、白ベタ画像を印刷させたところ良好な画像が得られた。
【００３１】
ついで電子写真装置の感光体をアルミニウム素管に変更し、温度、湿度が各々２０℃，５０％の環境で、１０００Ｖの電圧を印加したまま、１５０時間連続して回転させた後、上記と同様の方法で抵抗を測定した。電気抵抗は２０℃，５０％で2.０×１０⁸ Ω、３2.５℃，８５％で4.０×１０⁷ Ω、１５℃，１０％で4.０×１０⁹ Ωであった。
この転写ローラを前述と同様に電子写真装置に組み込み、１５℃，１０％の環境でグレースケール、黒ベタ、白ベタ画像を印刷させたところ、良好な画像が得られた。
【００３２】
比較例１
実施例１において、シュウ酸ベンジルトリメチルアンモニウム0.３重量部に代えて過塩素酸ナトリウム0.０５重量部とした以外は、実施例１と同様に実験を行った。初期抵抗は２０℃，５０％で5.８×１０⁷ Ω、３2.５℃，８５％で7.２×１０⁶ Ω、１５℃，１０％で4.０×１０⁸ Ωであり、画像評価も良好であった。ところが実施例１と同様の連続通電の後に電気抵抗は２０℃，５０％で4.７×１０⁸ Ω、３2.５℃，８５％で1.６×１０⁷ Ω、１５℃，１０％で1.１×１０¹⁰Ωとなり、１５℃，１０％の環境で黒ベタ画像を印刷させたところ、白線が現れる画像不良状態となった。
【００３３】
実施例２
実施例１において、シュウ酸ベンジルトリメチルアンモニウム0.３重量部に代えて変性脂肪族ジメチルエチルアンモニウムエトサルフェート0.３重量部とした以外は実施例１と同様に実験を行った。初期抵抗は２０℃，５０％で6.８×１０⁷ Ω、３2.５℃，８５％で1.０×１０⁷ Ω、１５℃，１０％で5.０×１０⁸ Ωであり、画像評価も良好であった。実施例１と同様の連続通電の後に電気抵抗は２０℃，５０％で2.０×１０⁸ Ω、３2.５℃，８５％で1.０×１０⁷ Ω、１５℃，１０％で5.０×１０⁹ Ωで、画像も良好であった。
【００３４】
実施例３
実施例１において、イソシアネート成分をジフェニルメタンジイソシアネートとカルボジイミド変性ジフェニルメタンジイソシアネートとグリコール変性ジフェニルメタンジイソシアネートの混合物１6.６重量部に代えてカルボジイミド変性ジフェニルメタンジイソシアネート１4.５重量部とした以外は実施例１と同様に実験を行った。初期抵抗は２０℃，５０％で1.５×１０⁸ Ω、３2.５℃，８５％で5.０×１０⁷ Ω、１５℃，１０％で1.５×１０⁹ Ωであり、画像評価も良好であった。実施例１と同様の連続通電の後に電気抵抗は２０℃，５０％で1.５×１０⁸ Ω、３2.５℃，８５％で4.０×１０⁷ Ω、１５℃，１０％で3.０×１０⁹ Ωで、画像も良好であった。
【００３５】
比較例２
実施例２において、イソシアネート成分をジフェニルメタンジイソシアネートとカルボジイミド変性ジフェニルメタンジイソシアネートとグリコール変性ジフェニルメタンジイソシアネートの混合物１6.６重量部に代えてトリレンジイソシアネート8.７重量部とした以外は実施例２と同様に実験を行った。初期抵抗は２０℃，５０％で5.０×１０⁷ Ω、３2.５℃，８５％で2.２×１０⁶ Ω、１５℃，１０％で8.０×１０⁸ Ωであり、３2.５℃，８５％の環境で黒ベタ画像を印刷させたところ、周辺部ににじみが現れる画像不良状態となった。
【００３６】
【発明の効果】
以上説明したように、本発明の導電性部材を用いた導電性ローラは、抵抗の環境変動が改良され、かつ連続使用においても抵抗上昇が抑制される。これを電子写真プロセスに適用すれば、長時間使用においても安定で良好な画像が得られるものである。
【図面の簡単な説明】
【図１】 電子写真装置の一例を示す概略図である。
【符号の説明】
１：導電性ローラ
２：感光体
３：電源
４：記録媒体[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a conductive member and an electrophotographic apparatus, and more specifically, a packaging member or an impact absorbing member having an antistatic function, or a conductive member such as a developing member and a transfer member used in a mechanism such as electrophotography, and the like. The present invention relates to an electrophotographic apparatus.
[0002]
[Prior art]
In recent years, with the advancement of electronic technology, there has been a demand for packaging members or shock absorbing members that require an antistatic function to protect electronic components, or conductive members used in electrophotographic apparatuses such as laser printers and dry copying machines. In particular, a medium-resistance elastic roller used in processes such as development and transfer is drawing attention.
[0003]
Conventionally, conductive members used for such applications are polymer materials such as rubber and urethane that are adjusted to a predetermined electrical resistance by mixing metal or metal oxide powder, whiskers and / or fillers such as carbon black. (Including foamed ones). The performance required for these conductive members is not only a predetermined electric resistance in a medium resistance region of 1 × 10 ⁴ to 1 × 10 ¹² Ω, but also a variation in electric resistance at low temperature and low humidity and high temperature and high humidity. The width is small.
[0004]
[Problems to be solved by the invention]
However, it is difficult to adjust the electrical resistance of the conductive member to a certain level by mixing carbon black or the like, and by mixing a filler such as metal or metal oxide powder or whisker and / or carbon black, The conductive member made of a polymer material adjusted to a predetermined electric resistance has a problem that the electric resistance has a large positional variation and the voltage dependency of the electric resistance is large.
[0005]
Thus, by incorporating an ionic conductive material such as sodium perchlorate, a conductive member having substantially no electrical resistance variation or voltage dependency in the middle resistance region is manufactured.
[0006]
However, In such rollers, for example 3 2. variation width is large and the electric resistance at 5 ° C. / 85% of such electrical resistance at high temperature and high humidity environment 15 ° C. / 10% of such a low-temperature and low-humidity environment, Further, when the operation is continued for a long time, the resistance gradually increases, and there is a problem that an image defect is caused when used for electrophotography.
[0007]
The present invention has been made in view of the above circumstances, and in a conductive member used in a mechanism such as electrophotography, there is usually little increase in electrical resistance due to continuous energization, and low temperature and low humidity and high temperature and high humidity. It is an object of the present invention to provide a conductive member having a small fluctuation range of electric resistance and an electrophotographic apparatus using the same.
[0008]
[Means for Solving the Problems]
The first conductive member of the present invention comprises (A) 100 parts by mass of polyurethane foam or polyurethane elastomer obtained using a polyisocyanate component containing carbodiimide-modified diphenylmethane diisocyanate and / or glycol-modified diphenylmethane diisocyanate, and (B ) A conductive material containing a conductivity-imparting agent comprising 0.001 to 5 parts by weight of a quaternary ammonium salt of oxalic acid is used.
[0009]
The second conductive member of the present invention is characterized in that the conductive material is a foam body.
[0010]
In the third electrophotographic apparatus of the present invention, the developer is brought into contact with or close to the image forming body in a state where the developer is carried on the surface of the first or second conductive member, and the developer is removed by rotating the image forming body. It has a developing device that adheres to the surface and forms a visible image on the surface of the image forming body.
[0011]
According to a fourth electrophotographic apparatus of the present invention, there is provided a transfer device that charges a recording medium with the first or second conductive member and transfers the developer onto the recording medium from the electrostatic latent image visualized by the developer. It is characterized by having.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
As a result of intensive studies to achieve the above-mentioned object, the present inventors have obtained a quaternary ammonium salt, particularly an alkylsulfuric acid, as a conductive member, to a polyurethane using a specific modified diphenylmethane diisocyanate as a polyisocyanate component. It has been found that the object can be achieved by using a conductive material to which a conductivity imparting agent comprising a quaternary ammonium salt or a quaternary ammonium salt of a carboxylic acid is added. That is, the conductive material has a volume resistivity of 1 × 10 ⁵ Ωcm or more and 1 × 10 ¹⁰ Ωcm or less in the measurement voltage range of 10 to 5000 V, and there is little variation in the position of the electrical resistance. There is little variation in electrical resistance in a high temperature and high humidity environment such as 5 ° C./85% and low temperature and low humidity environment such as 15 ° C./10%, and the voltage dependence of the electrical resistance is in the range of 10 to 5000V. In addition, the electrical resistance change after 50 hours of continuous energization at a current density of 0.5 μA / cm ² is 15% even in a high-temperature and high-humidity environment of 32.5 ° C./85% compared to before continuous energization. It has been found that even in a low-temperature and low-humidity environment such as ° C / 10%, the electrical resistance during continuous energization is stable and an excellent conductive member is obtained. The present invention has been completed based on such knowledge.
[0013]
Hereinafter, the present invention will be described in more detail.
As described above, the conductive member according to the present invention is obtained by using one or more selected from (A) polyisocyanate component selected from carbodiimide-modified diphenylmethane diisocyanate, glycol-modified diphenylmethane diisocyanate, and isocyanurate-modified diphenylmethane diisocyanate. A conductive material containing the obtained polyurethane foam or polyurethane elastomer and (B) a conductivity imparting agent comprising a quaternary ammonium salt is used.
[0014]
Here, the polyisocyanate component in (A) polyurethane foam or polyurethane elastomer includes (1) carbodiimide-modified diphenylmethane diisocyanate, (2) glycol-modified diphenylmethane diisocyanate (for example, ethylene glycol-modified diphenylmethane diisocyanate) and (3) isocyanurate-modified diphenylmethane diisocyanate. It is necessary to use at least one of the following.
By using these modified diphenylmethane diisocyanates, fluctuations in the electrical resistance of the obtained conductive member, particularly electrical resistance in a high temperature and high humidity environment such as 32.5 ° C./85% and low temperature and low humidity environment such as 15 ° C./10%. It is possible to reduce fluctuations in electrical resistance.
[0015]
In the present invention, as the polyisocyanate component, at least one of the above-mentioned modified diphenylmethane diisocyanates of (1) to (3) may be used. Furthermore, ordinary diphenylmethane diisocyanate and hydrogenated products thereof, other modified diphenylmethane diisocyanates, It is also possible to use modified hexamethylene diisocyanate (for example, hexamethylene diisocyanate adduct with trimethylolpropane, isocyanurate-modified hexamethylene diisocyanate, biuret-modified hexamethylene diisocyanate, uretdione hexamethylene diisocyanate), tolylene diisocyanate, isophorone diisocyanate, etc. it can.
[0016]
The polyurethane foam or polyurethane elastomer which is the component (A) used in the present invention may use at least one of the above-mentioned modified diphenylmethane diisocyanates (1) to (3) as a polyisocyanate component as described above. There are no particular restrictions on the conditions. The polyurethane foam can be either soft or hard, but is preferably soft. Moreover, the property is not particularly limited, and may be appropriately selected according to various situations.
[0017]
In the present invention, the polyol component for producing the polyurethane foam or polyurethane elastomer as the component (A) by reacting with the polyisocyanate component is not particularly limited and may be appropriately selected according to various situations. For example, (1) ethylene glycol; diethylene glycol; 1,4-butanediol; 1,6-hexanediol; diols such as propylene glycol, triols such as trimethylolethane and trimethylolpropane, and adipic acid, glutaric acid, succinic acid, and sebacin Condensed polyester polyols obtained from dicarboxylic acids such as acids, pimelic acid, and suberic acid, and (2) lactones such as γ-butyrolactone, δ-valerolactone, and ε-caprolactone, ethylene glycol; diethylene glycol 1,4-butanediol; 1,6-hexanediol; a lactone polyester polyol obtained by ring-opening polymerization in the presence of a diol such as propylene glycol or a triol such as trimethylolethane or trimethylolpropane; (3) poly Ester-modified polyol in which the end of ether polyol is modified with lactones such as γ-butyrolactone, δ-valerolactone, and ε-caprolactone, (4) Polyethylene alcohol such as ethylene glycol, propylene glycol, and glycerin with ethylene oxide or propylene oxide. Examples include polyether polyols obtained by addition, (5) polyethers such as polytetramethylene ether glycol obtained by ring-opening polymerization of tetrahydrofuran, and the like. As these polyol components, those having a number average molecular weight of 200 to 5000 having 2 to 4 functional groups in one molecule are suitable. These polyol components may be used alone or in combination of two or more.
[0018]
A chain extender can also be used here. Examples of the chain extender include ethylene glycol; propylene glycol; short chain diols such as 1,4-butanediol, ethylenediamine, tetramethylenediamine, and hexamethylenediamine. And short chain diamines. These chain extenders may be used alone or in combination of two or more.
The polyurethane foam or polyurethane elastomer used in the present invention includes a crosslinked polyurethane. As crosslinking of polyurethane, various crosslinking methods such as allophanate crosslinking and burette crosslinking are known, and any method can be used.
In the conductive material used for the conductive elastic member of the present invention, a quaternary ammonium salt is used as the conductivity imparting agent of the component (B). As this quaternary ammonium salt, various compounds can be used.
[0019]
[Chemical 1]

[0020]
(In the formula, R ¹ is an alkyl group having 1 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms, or an aralkyl group having 7 to 30 carbon atoms, and R ² , R ^3, and R ⁴ are each independently 1 carbon atom. It indicates 6 alkyl group, X ^n-represents an n-valent anion. Here, n is an integer from 1 to 6.)
The compound represented by these can be mentioned.
In the general formula (I), the alkyl group having 1 to 30 carbon atoms in R ¹ may be linear, branched or cyclic, and examples thereof include a methyl group, an ethyl group, a propyl group, Examples include butyl, hexyl, octyl, nonyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, eicosyl, cyclopentyl, cyclohexyl, cyclooctyl, cyclododecyl and the like. Examples of the aryl group having 6 to 30 carbon atoms include a phenyl group and a naphthyl group. Examples of the aralkyl group having 7 to 30 carbon atoms include a benzyl group, a phenethyl group, and a naphthylmethyl group. In the aryl group and aralkyl group, a suitable inert group such as a lower alkyl group, a lower alkoxy group, or a halogen may be introduced on the carbocyclic ring.
[0021]
The alkyl group having 1 to 6 carbon atoms represented by R ² , R ³ and R ⁴ may be linear, branched or cyclic, and examples thereof include a methyl group, an ethyl group, and the like. Examples include propyl group, butyl group, pentyl group, hexyl group, cyclopentyl group, cyclohexyl group and the like. R ² , R ³ and R ⁴ may be the same or different.
Further, as X ⁿ⁻ , for example, halogen ions of F ⁻ , Cl ⁻ , Br ⁻ , I ⁻ , inorganic acid ions such as NO ₃ ⁻ , CO ₃ ²⁻ , SO ₄ ²⁻ , ClO ₄ ⁻ , and BF ₄ ⁻ , Acetate radical (CH ₃ COO ⁻ ), benzoate radical, malonate radical, oxalate radical, tartrate radical, citrate radical, malate radical, succinate radical, maleate radical, fumarate radical, phthalate radical, isophthalic acid radical, terephthalic acid radical, trimellitic acid radical, Organic acid (carboxylic acid) ions such as trimesic acid group and tricarbalic acid group, and other formulas represented by CH ₃ OSO ₃ ⁻ , C ₂ H ₅ OSO ₃ ^—, etc. ROSO ₃ ⁻ (R is alkyl having 1 to 10 carbon atoms) Group), a sulfur-containing organic acid ion such as p-toluenesulfonic acid radical, and the like.
As for X ⁿ⁻ , a carboxylate ion or an alkyl sulfate ion is particularly preferable.
[0022]
Examples of the quaternary ammonium salt represented by the general formula (I) include various types, from the viewpoint of obtaining good environmental stability of electrical resistance, resistance stability during continuous energization, and the like. Quaternary ammonium salts of alkyl sulfuric acids and quaternary ammonium salts of carboxylic acids are preferred. Specifically, as the quaternary ammonium salt of alkylsulfuric acid, quaternary ammonium salts such as modified aliphatic dimethylethylammonium etosulphate, tetraalkylammonium etosulphate, lauroylaminopropyldimethylethylammonium etosulphate, and the like are used. Quaternary ammonium salts of carboxylic acids include benzyltrimethylammonium maleate, benzyltriethylammonium maleate, benzyltriethylammonium fumarate, benzyltriethylammonium fumarate, benzyltriethylammonium malonate, benzyltriethylammonium malonate, benzyl oxalate Trimethylammonium, benzyltriethylammonium oxalate, benzyltrimethylammonium malate, phosphorus Benzyltriethylammonium acid, benzyltriethylammonium tartrate, benzyltriethylammonium tartrate, benzyltriethylammonium citrate, benzyltriethylammonium citrate, benzyltriethylammonium phthalate, benzyltriethylammonium phthalate, benzyltriethylammonium isophthalate, benzyltriethylammonium isophthalate , Benzyltrimethylammonium terephthalate, benzyltriethylammonium terephthalate, benzyltriethylammonium trimellitic acid, benzyltriethylammonium trimellitic acid, tetramethylammonium maleate, tetrabutylammonium maleate, tetramethylammonium fumarate, tetrabutyl fumarate Ammonium, tetramethylammonium malonate, tetrabutylammonium malonate, tetramethylammonium oxalate, tetrabutylammonium oxalate, tetramethylammonium malate, tetrabutylammonium malate, tetramethylammonium tartrate, tetrabutylammonium tartrate, citric acid Tetramethylammonium, tetrabutylammonium citrate, tetramethylammonium phthalate, tetrabutylammonium phthalate, tetramethylammonium isophthalate, tetrabutylammonium isophthalate, tetramethylammonium terephthalate, tetrabutylammonium terephthalate, tetratrimellitic acid tetra Methylammonium, trimellitic acid tetrabutylammonium, di-cured tallow alkyl A quaternary ammonium salt such as dimethylammonium acetate is used.
[0023]
This quaternary ammonium salt may be used alone or in combination of two or more. The blending amount is not particularly limited and may be appropriately selected according to various situations. For example, the volume resistivity of the obtained conductive material is 1 × 10 ^{5 in the} middle resistance region, particularly at an applied voltage of 1000V. ˜1 × 10 ¹⁰ Ωcm, 0.001 to 5 parts by weight is preferable with respect to 100 parts by weight of the polyurethane foam or polyurethane elastomer of the component (A), particularly 0.05 to 1 part by weight. The range of is more preferable.
The method of blending the quaternary ammonium salt into the polyurethane foam or polyurethane elastomer of the component (A) is not particularly limited, but it is added to the reaction system during the production of the polyurethane foam or polyurethane elastomer of the component (A). Is advantageous. At this time, it may be added in the form of a quaternary ammonium salt, or a quaternary ammonium hydroxide and a polyfunctional acid may be added separately. When added in the form of a quaternary ammonium salt or quaternary ammonium hydroxide, it is preferably added after being dissolved in a solvent such as ether, alcohol, ester, lactone, or carbonate.
[0024]
Further, as a conductivity imparting agent, together with the quaternary ammonium salt of the component (B), as long as the object of the present invention is not impaired, conventionally used sodium perchlorate, potassium perchlorate, Inorganic salts such as calcium perchlorate and conductive fillers such as carbon black, metal powder, and metal oxide powder may be used in combination.
Next, there is no restriction | limiting in particular about the manufacturing method of the electroconductive material used for this invention, Although what is necessary is just to follow a usual method, if the example is shown, it will be as follows.
First, after mixing the above polyisocyanate component, polyol component, chain extender, quaternary ammonium salt and other conductivity-imparting agents, catalysts, reinforcing agents, colorants, foam stabilizers, etc. as required. By heating and reaction curing, a conductive material containing a conductivity imparting agent in the polyurethane elastomer is obtained. In addition, the polyol component is pre-isocyanated with a polyisocyanate component, and this, a chain extender, a quaternary ammonium salt, and other conductivity-imparting agents used as required, a catalyst, a reinforcing agent, a colorant, and a foam stabilizer. After the agent and the like are mixed homogeneously, the reaction may be cured by heating.
[0025]
Moreover, when making it heat-react and harden | cure by a conventionally well-known method, the electroconductive material formed by containing a electroconductivity imparting agent in a polyurethane foam is obtained. In the present invention, the conductive material obtained is preferably a foam body. Here, there is no restriction | limiting in particular about the foaming method, Any methods, such as the method of using a foaming agent and the method of mixing bubbles by mechanical stirring, can be used. The expansion ratio may be determined as appropriate and is not particularly limited.
The polyurethane foam or polyurethane elastomer can be cross-linked as desired for the purpose of improving heat resistance, chemical resistance, mechanical strength and the like.
[0026]
The conductive material thus obtained has a desired volume resistivity value depending on the conditions during production, and the volume resistivity value at an applied voltage of 1000 V is usually 1 × 10 ⁶ to 1 × 10 ¹¹ Ωcm. And there is little variation in the position of the electrical resistance. In addition, the dependence of the electric resistance on the applied voltage is small, and at the same time, the fluctuation range of the electric resistance during continuous energization and the fluctuation of the electric resistance due to environmental changes such as temperature and humidity are small.
The conductive elastic member of the present invention exhibits a stable resistance value in a medium resistance region, particularly in a medium resistance region of 1 MΩ to 100 GΩ, and is an electrophotographic conductive member, specifically, a transfer roller, a developing roller, etc. in an electrophotographic apparatus. Is preferably used.
The method for producing the conductive elastic member of the present invention is not particularly limited, and various known methods may be used. For example, by coating a core metal such as iron plated or stainless steel with the conductive material, and coating the outside with a conductive, semiconductive, or insulating paint depending on the application, 1 MΩ to 100 GΩ. The conductive member of the present invention showing a stable resistance value in the middle resistance region is obtained. The shape of the conductive member of the present invention is not particularly limited and may be determined depending on the application. Examples thereof include a roller shape, a plate shape, a square block shape, a spherical shape, and a brush shape. Or plate shape.
[0027]
Next, an example in which the conductive elastic member of the present invention is used as a transfer roller of an electrophotographic copying machine will be described.
FIG. 1 is an explanatory view showing an example of a transfer device of an electrophotographic copying machine using the conductive elastic member of the present invention, which is composed of the conductive elastic member of the present invention having a core bar (not shown). A conductive roller (transfer roller) 1 is brought into contact with a toner image carrier 2 such as a photosensitive drum via a transfer material 4 such as paper, and between the conductive roller 1 and the toner image carrier 2, A voltage is applied by the power source 3 to generate an electric field between the toner image carrier and the conductive roller, thereby transferring the toner on the toner image carrier 2 to the transfer material 4.
When the conductive elastic member of the present invention is incorporated in an electrophotographic apparatus such as a copying machine, it is applied to an electrostatic image developing unit, a developer transferring unit such as toner.
[0028]
【Example】
EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated concretely, this invention is not limited to the following Example.
Example 1
Propylene oxide and ethylene oxide are added to glycerin, 100 parts by weight of a polyether polyol having a molecular weight of 5000, 16.6 parts by weight of a mixture of diphenylmethane diisocyanate, carbodiimide-modified diphenylmethane diisocyanate and glycol-modified diphenylmethane diisocyanate, reactive silicone surfactant 4 Part by weight, 0.01 part by weight of dibutyltin dilaurate and 0.3 part by weight of benzyltrimethylammonium oxalate were mixed with a mixer, and the mixture was 16.5 mm in diameter with a metal shaft having a diameter of 6 mm as the center. A urethane foam transfer roller having a thickness of 215 mm was produced.
[0029]
Next, the transfer roller was placed on an aluminum plate having a thickness of 5 mm, and the electric resistance between the metal core and the copper plate of the resistance measuring device was measured while pressing both ends of the roller with a force of 500 g. The temperature and humidity at the time of measurement were 20 ° C. and 50%, respectively. The electric resistance was 2.0 × 10 ⁸ Ω when the applied voltage was 1000V. When the measurement temperature and humidity are 32.5 ° C. and 85%, respectively, the applied voltage is 1000 V and the electrical resistance is 5.2 × 10 ⁷ Ω, and when 15 ° C. and 10%, the applied voltage is 1000 V and 1.7 × 10 ^9. Ω.
[0030]
Further, the transfer roller was incorporated in the electrophotographic apparatus shown in FIG. When a gray scale, black solid, or white solid image is printed in an environment where the temperature and humidity are 15 ° C. and 10%, a good image is obtained. Further, in an environment where the temperature and humidity are 32.5 ° C. and 85%, respectively. When a grayscale, black solid, or white solid image was printed, a good image was obtained.
[0031]
Next, the photoconductor of the electrophotographic apparatus was changed to an aluminum base tube, and continuously rotated for 150 hours while applying a voltage of 1000 V in an environment where the temperature and humidity were 20 ° C. and 50%, respectively. The resistance was measured by the method. The electrical resistance was 2.0 × 10 ⁸ Ω at 20 ° C. and 50%, 4.0 × 10 ⁷ Ω at 32.5 ° C. and 85%, and 4.0 × 10 ⁹ Ω at 15 ° C. and 10%.
When this transfer roller was incorporated into an electrophotographic apparatus in the same manner as described above and a gray scale, black solid or white solid image was printed in an environment of 15 ° C. and 10%, a good image was obtained.
[0032]
Comparative Example 1
The experiment was conducted in the same manner as in Example 1 except that 0.05 part by weight of sodium perchlorate was used instead of 0.3 part by weight of benzyltrimethylammonium oxalate. The initial resistance is 5.8 × 10 ⁷ Ω at 20 ° C. and 50%, 7.2 × 10 ⁶ Ω at 32.5 ° C. and 85%, and 4.0 × 10 ⁸ Ω at 15 ° C. and 10%. Evaluation was also good. However, after continuous energization as in Example 1, the electrical resistance is 4.7 × 10 ⁸ Ω at 20 ° C. and 50%, and 1.6 × 10 ⁷ Ω at 152.5 ° C. and 85% at 15 ° C. and 10%. 1.1 neighboring × ¹⁰ 10 Ω, 15 ℃, was to print the black solid image with a 10% RH, was the image defect state white line appears.
[0033]
Example 2
The experiment was conducted in the same manner as in Example 1 except that 0.3 part by weight of modified aliphatic dimethylethylammonium ethosulphate was used instead of 0.3 part by weight of benzyltrimethylammonium oxalate. The initial resistance is 6.8 × 10 ⁷ Ω at 20 ° C. and 50%, 1.0 × 10 ⁷ Ω at 32.5 ° C. and 85%, and 5.0 × 10 ⁸ Ω at 15 ° C. and 10%. Evaluation was also good. After continuous energization as in Example 1, the electrical resistance was 2.0 × 10 ⁸ Ω at 20 ° C. and 50%, 1.0 × 10 ⁷ Ω at 32.5 ° C. and 85%, and 5 at 15 ° C. and 10%. The image was good at 0.0 × 10 ⁹ Ω.
[0034]
Example 3
In the same manner as in Example 1, except that the isocyanate component was changed to 14.5 parts by weight of carbodiimide-modified diphenylmethane diisocyanate instead of 16.6 parts by weight of the mixture of diphenylmethane diisocyanate, carbodiimide-modified diphenylmethane diisocyanate and glycol-modified diphenylmethane diisocyanate. Went. The initial resistance is 1.5 × 10 ⁸ Ω at 20 ° C. and 50%, and 5.0 × 10 ⁷ Ω at 32.5 ° C. and 85%, and 1.5 × 10 ⁹ Ω at 15 ° C. and 10%. Evaluation was also good. After continuous energization in the same manner as in Example 1, the electrical resistance is 1.5 × 10 ⁸ Ω at 20 ° C. and 50%, 4.0 × 10 ⁷ Ω at 32.5 ° C. and 85%, 3 at 15 ° C. and 10%. The image was good at 0.0 × 10 ⁹ Ω.
[0035]
Comparative Example 2
In Example 2, the experiment was conducted in the same manner as in Example 2 except that the isocyanate component was changed to 16.7 parts by weight of a mixture of diphenylmethane diisocyanate, carbodiimide-modified diphenylmethane diisocyanate and glycol-modified diphenylmethane diisocyanate, and 8.7 parts by weight of tolylene diisocyanate. went. The initial resistance is 5.0 × 10 ⁷ Ω at 20 ° C. and 50%, 2.2 × 10 ⁶ Ω at 32.5 ° C. and 85%, and 8.0 × 10 ⁸ Ω at 15 ° C. and 10%. When a black solid image was printed in an environment of .5 ° C. and 85%, an image defect state in which bleeding occurred in the peripheral portion.
[0036]
【The invention's effect】
As described above, the conductive roller using the conductive member of the present invention is improved in resistance fluctuation in the environment and suppresses the increase in resistance even during continuous use. If this is applied to an electrophotographic process, a stable and good image can be obtained even when used for a long time.
[Brief description of the drawings]
FIG. 1 is a schematic diagram illustrating an example of an electrophotographic apparatus.
[Explanation of symbols]
1: Conductive roller 2: Photoconductor 3: Power supply 4: Recording medium

Claims (4)

(A) and carbodiimide-modified diphenylmethane diisocyanate and / or glycol-modified diphenylmethane diisocyanate polyurethane foam or polyurethane elastomer 100 parts by weight obtained using a polyisocyanate component comprising, (B) quaternized ammonium salt of oxalic acid 0. A conductive member comprising a conductive material containing a conductivity imparting agent comprising 001 to 5 parts by weight.   The conductive member according to claim 1, wherein the conductive material is a foam body.   3. The image forming body, wherein the developer is attached to the surface of the image forming body by rotating or contacting the image forming body in a state where the developer is carried on the surface of the conductive member according to claim 1 or 2 and rotating. An electrophotographic apparatus comprising: a developing device that forms a visible image on a surface.   An electrophotographic apparatus comprising: a transfer device that charges a recording medium with the conductive member according to claim 1 and transfers the developer onto the recording medium from an electrostatic latent image visualized by the developer.

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