JP3922845B2

JP3922845B2 - Seamless belt manufacturing method

Info

Publication number: JP3922845B2
Application number: JP25720799A
Authority: JP
Inventors: 智小田嶋; 利行川口; 登代次日比
Original assignee: Shin Etsu Polymer Co Ltd
Current assignee: Shin Etsu Polymer Co Ltd
Priority date: 1999-09-10
Filing date: 1999-09-10
Publication date: 2007-05-30
Anticipated expiration: 2019-09-10
Also published as: JP2001079862A

Description

【０００１】
【発明の属する技術分野】
本発明は、電子写真式の複写機やレーザプリンタ等に使用されるシームレスベルトに関し、より詳しくは、中間転写用、用紙搬送用、現像用、あるいは定着用のシームレスベルトの製造方法に関するものである。
【０００２】
【従来の技術】
従来、厚いシームレスベルトを製造する場合には、図示しないが、先ず、円筒形で片持ちの金型を低速回転させ、この金型内に進退動可能な供給装置のノズルを進出させ、このノズルから高分子材料溶液を回転する金型の内周面一端部から他端部にかけて２ｋｇｆ／ｃｍ²以上の圧力で噴射塗布してレベリングし、材料を乾燥させてシームレスベルトを遠心成形する。そして、シームレスベルトを加熱、冷却し、その後、シームレスベルトを所定の長さとして完成させるようにしている。
【０００３】
【発明が解決しようとする課題】
従来の厚いシームレスベルトの製造方法は、以上のように金型の内周面一端部から他端部にかけて高分子材料溶液を高い圧力で供給して飛翔塗布するので、金型への接触時に高分子材料溶液の波打ち飛散を生じ、この結果、シームレスベルトの肉厚が不均一化してしまうという大きな問題があった。
【０００４】
本発明は、上記問題に鑑みなされたもので、金型内で高分子材料溶液が波打ったり、表面に風紋状の模様が生じるのを抑制防止し、厚さ５０μｍ以上、特には８０μｍ以上、通常１ｍｍ以下の厚いシームレスベルトの肉厚の均一化を図ることのできるシームレスベルトの製造方法を提供することを目的としている。
【０００５】
【課題を解決するための手段】
本発明においては上記課題を達成するため、高分子材料溶液を円筒形で横長の金型に供給してシームレスベルトを成形する製造方法であって、
金型の両端部にそれぞれ着脱自在に嵌め合わされるリング形を呈した一対の蓋と、各蓋の外周面下部一側を接触支持する複数の駆動輪と、各蓋の外周面下部他側を接触支持し、金型の回転に伴い回転する複数の従動輪とを含み、
複数の駆動輪に対して複数の従動輪を水平横方向にスライド可能とするとともに、複数の駆動輪と従動輪の外周面を、３０°Ｈｓ〜９０°Ｈｓの硬度を有する耐熱性の弾性エラストマーでそれぞれ被覆し、
金型を回転させてその周囲から加熱し、粘度の高い線条の高分子材料溶液を金型内の長手方向一端部から他端部にかけて連続的に吐き出して金型の内周面に均一にレベリングし、金型の加熱を継続してシームレスベルトを遠心成形することを特徴としている。
【０００６】
本発明によれば、材料溶液を飛び散らせるのではなく、吐出ノズルから高分子材料溶液を連続して垂れ落とし、安定した状態で塗布するので、金型内で高分子材料溶液が波打ち飛散したり、シームレスベルトの肉厚が不均一化するのを抑制あるいは防止することができる。
【０００７】
【発明の実施の形態】
以下、図面を参照して本発明の好ましい実施形態を説明すると、本実施形態におけるシームレスベルトの製造方法は、図１に示すように、供給装置１の吐出ノズル２から高分子材料溶液４を成形装置６の金型７内の長手方向一端部から他端部にかけて所定の吐出圧力で連続して垂らしながら吐出塗布するようにしている。
【０００８】
供給装置１は、図１に示すように、細長い吐出ノズル２を水平に備えた各種のポンプ３と、このポンプ３に高分子材料溶液４を供給するホッパ５とから構成されている。そして、図示しない歯車機構やベルト機構の駆動に基づき、矢印で示すように金型７の軸方向に対して進退動し、吐出ノズル２の先端部から２０〜３０ｍｍ離れた金型７の内周面に粘度の高い(常温時で１ポイズ以上、１００ポイズ以下)液状の高分子材料溶液４を筋状、線条に連続して垂らしながら塗布する。
【０００９】
高分子材料溶液４は、ＮＭＰ等の各種溶剤にＰＥＳやＰＥＴ等の高分子材料を溶解させ、カーボン等を配合等させたものである。高分子材料としては、これらの他にも、ＰＢＴ、ＰＥＮ等のポリエステル系樹脂、ポリイミド系樹脂、ポリアミドイミド系樹脂、ポリアミド系樹脂、フッ素樹脂、ポリサルフォン、ポリカーボネート、アラミド樹脂、又はポリエーテルエーテルケトン等があげられるが、これらの中でも耐熱性、抗張力、耐クリープ特性に優れるＰＡＩやＰＥＳが好ましい。高分子材料は、熱可塑性や熱硬化性のいずれでも良く、実施する製造方法により適当なものを選択することができる。
【００１０】
成形装置６は、図２や図３に示すように、シームレスベルト２０を遠心成形する金型７と、この金型７を回転させる駆動装置８と、この駆動装置８に対して接離可能な従動装置９とから構成されている。金型７は、各種金属を使用して横長の円筒形に形成され、シームレスベルト２０を容易に脱型できるよう内周面に滑らかな鏡面加工、フッ素加工、あるいはシリコーン樹脂加工等が施されるとともに、外周面には図示しないつや消しの黒色が塗布されており、この黒色が外部ヒータからの熱を効率的に吸収する。金型７の両端部には高分子材料溶液４の漏洩を防止するリング形の蓋１０がそれぞれ着脱自在に嵌合され、蓋１０の中心部には高分子材料溶液４用の注入孔が設けられている。
【００１１】
駆動装置８は、各種のモータ１１と、このモータ１１の駆動で回転する駆動軸１２と、この駆動軸１２に嵌着される複数の駆動輪１３と、各駆動輪１３の外周面に覆着され、蓋１０の外周面下部を接触担持して制振機能を発揮する耐熱耐久性で円筒形の弾性エラストマー１４とから構成されている。弾性エラストマー１４は、例えば耐油性、耐溶剤性、耐薬品性、耐候性、耐熱性等に優れるシリコーンゴム、クロロプレンゴム、又はフッ素ゴム等からなり、９０°Ｈｓ以下、好ましくは３０°Ｈｓ〜９０°Ｈｓの硬度を有している。これは、３０°Ｈｓ未満だと圧縮永久歪み特性が悪化し、９０°Ｈｓを超えると制振性が乏しくなるからである。
【００１２】
従動装置９は、図２に示すように、駆動軸１２に対して水平横方向にスライドするフリーの従動軸１５と、この従動軸１５に嵌着される複数の従動輪１６と、各従動輪１６の外周面に覆着され、蓋１０の外周面下部を接触担持して制振機能を発揮する耐熱耐久性で円筒形の弾性エラストマー１４Ａとから構成されている。弾性エラストマー１４Ａについては、駆動装置８の弾性エラストマー１４と同様であるので説明を省略する。
【００１３】
次に、シームレスベルト２０の具体的な製造方法を説明すると、先ず、駆動装置８を駆動して水平状態の金型７を高速(例えば、９００〜１，０００ｒｐｍ)で回転させるとともに、この金型７を外部ヒータで所定の温度(特に制約はないが、７０℃〜１００℃程度)に加熱し、供給装置１を回転する金型７に対し適宜進退動させて金型７の内周面一端部から他端部にかけて高分子材料溶液４を０．５ｋｇｆ／ｃｍ²以下の吐出圧力で吐出ノズル２の先端部から連続して垂下させながら徐々に吐出塗布(吐出量は、例えば１０秒で５０ｇ〜５００ｇから選択された範囲)し、金型７の内周面に高分子材料溶液４を均一にレベリングする。
【００１４】
吐出圧力が０．５ｋｇｆ／ｃｍ²以下なのは、０．５ｋｇｆ／ｃｍ²を超えると、波打ちが生じ始め、しかも、高分子材料溶液４の粘度にもよるが、おおよそ０．８ｋｇｆ／ｃｍ²を超えると、飛散を招くからである。こうして高分子材料溶液４を完全にレベリングしたら、金型７を外部ヒータで周囲から継続加熱して高分子材料溶液４の粘度低減や溶剤の蒸発を促進する。
【００１５】
金型７を所定時間加熱したら、成形装置６を停止させて金型７を取り外し、金型７を乾燥機にセットして残留溶剤を蒸発・乾燥させ、乾燥機から金型７を取り外して室温で空冷する。すると、金型７と遠心成形されたシームレスベルト２０の熱膨張差により、金型７の内周面からシームレスベルト２０が自然に剥離する。金型７とシームレスベルト２０とが強く密着して離れない場合には、シームレスベルト２０の端部から徐々に剥がせば、金型７からシームレスベルト２０を脱型することができる。そしてその後、シームレスベルト２０の両端部をそれぞれ所定の長さで切断すれば、可撓性を有する円筒形で厚肉のシームレスベルト２０を得ることができる。
【００１６】
上記方法によれば、高粘度の高分子材料溶液４を吐出ノズル２の先端部から連続して吐出塗布するので、金型７内で高分子材料溶液４が波打ったり、得られるシームレスベルト２０の表面に風紋状の模様が生じるのをきわめて有効に抑制防止し、シームレスベルト２０の肉厚を著しく均一化することができる。したがって、厚さ５０μｍ以上、特には８０μｍ以上、通常１ｍｍ以下の高精度の厚いシームレスベルト２０を短時間に好適に製造することができる。また、不安定な片持ちではなく、駆動装置８と従動装置９とで金型７を安定状態に搭載するので、小径のみならず、２００ｍｍ以上の大径のシームレスベルト２０をも容易に遠心成形することが可能となる。また、低速回転ではなく、高速回転中の金型７に高分子材料溶液４を塗布するので、迅速なレベリングが非常に容易になる。
【００１７】
また、駆動装置８の駆動輪１３のみで金型７を回転させ、従動輪１６を従わせて回転させるので、駆動輪１３と従動輪１６との間に速度差の発生することがなく、簡易な構成で金型７の上下動や微小なスリップをきわめて有効に防止することができる。さらに、駆動装置８に対して従動装置９が図２の矢印方向に接近又は離隔するので、金型７のメンテナンスや交換の便宜を図ったり、異なる使用の金型７に簡単に対処することが期待できる。さらにまた、弾性エラストマー１４・１４Ａが耐熱性に優れるので、金型７を加熱しても、長時間の連続使用が大いに期待できる。
【００１８】
なお、上記実施形態では駆動装置８と従動装置９とを使用したが、従動装置９を省略し、一対の駆動装置８を使用することもできる。また、駆動装置８に対して従動装置９を接離可能としたが、従動装置９に対して駆動装置８を接離可能としたり、駆動装置８と従動装置９とを相互に接離可能としても良い。また、蓋１０の外周面下部に駆動輪１３や従動輪１６の弾性エラストマー１４・１４Ａを接触させたが、金型７の外周面下部に駆動輪１３や従動輪１６の弾性エラストマー１４・１４Ａを接触させても良い。また、シームレスベルト２０は、半導電性でも良いし、そうでなくても良い。さらに、高分子材料溶液４を完全にレベリングした後、高速回転する金型７を乾燥時に低速回転(例えば、２００〜２５０ｒｐｍ)させて溶剤を遠心力から解放し、排出するようにすれば、乾燥時間を短縮し、シームレスベルト２０の肉厚をさらに均一化することができる。
【００１９】
【実施例】
以下、本発明に係るシームレスベルトの製造方法の高分子材料溶液、実施例、比較例、及び評価について順次説明する。
高分子材料溶液の調整
先ず、トリメリット酸無水物と４，４′−ジアミノジフェニルメタンとの当量をジメチルアセトアミドに溶解し、加熱反応して固形分濃度(実質的全閉環のポリアミドイミド)２８重量％の芳香族ポリアミドイミドを調整した。これにジメチルアセトアミドを加え、固形分濃度１５重量％、固形分の比重１．２のポリアミドイミド溶液を得た。
次いで、カーボンフィラーとして、ジメチルアセトアミドにキャボット製「ＳｐｅｃｉａｌＢｌａｃｋＭＯＮＡＲＣＨ１２０」を１５重量％となるよう混合した。そして、ビーズミルで１時間分散処理したカーボンフィラー混合液をポリアミドイミド溶液１００重量部に対し、カーボンフィラー混合液を２０重量部加え、ビーズミルで１時間混合処理してポリアミドイミド−カーボンブラック混合溶液を得た。
【００２０】
実施例
先ず、金型(内径２００ｍｍ、外径２２０ｍｍ、長さ４００ｍｍ)７に蓋(内径１７０ｍｍ、外径２２０ｍｍ)１０を嵌合し、この金型７を成形装置６に搭載支持させた。こうして金型７を搭載したら、駆動装置８を駆動して水平の金型７を１，０００ｒｐｍの高速で回転させ、供給装置１を回転する金型７に対し適宜移動させて金型７の内周面一端部から他端部にかけてポリアミドイミド−カーボンブラック混合溶液からなる高分子材料溶液４を吐出ノズル(φ５ｍｍ)２の先端部から吐出圧力０．１ｋｇｆ／ｃｍ²で連続して垂下させながら吐出塗布し、金型７の内周面に高分子材料溶液４を均一にレベリングした。この場合の高分子材料溶液４の供給量は２１５ｇである。
【００２１】
次いで、熱風温風機により金型７の雰囲気温度を８０℃に維持し、高分子材料溶液４の粘度低減や溶剤の蒸発を促進させた。８０℃の雰囲気温度を３０分保ったら、成形装置６を停止させて金型７を取り外し、金型７を１８０℃のオーブンにセットして残留溶剤を蒸発・乾燥させ、４５分後にオーブンから金型７を取り外して室温で空冷した。そして、金型７とシームレスベルト２０の熱膨張差を利用して金型７の内周面からシームレスベルト２０を剥離し、幅２６０ｍｍにカットして厚さ約１００μｍのシームレスベルト２０を得た。
【００２２】
比較例
先ず、実施例と同様の金型７に同様の蓋１０をセットし、この金型７を成形装置６に搭載支持させた。金型７を搭載したら、駆動装置８を駆動して水平の金型７を１，０００ｒｐｍの高速で回転させ、供給装置１を回転する金型７に対し適宜移動させて金型７の内周面一端部から他端部にかけてポリアミドイミド−カーボンブラック混合溶液からなる高分子材料溶液４を吐出ノズル(φ０．２ｍｍ)２の先端部から吐出圧力２．０ｋｇｆ／ｃｍ²で連続して飛翔させながら吐出塗布し、金型７の内周面に高分子材料溶液４をレベリングした。この場合の高分子材料溶液４の供給量は２１５ｇである。
【００２３】
次いで、熱風温風機により金型７の雰囲気温度を８０℃に保ち、高分子材料溶液４の粘度低減や溶剤の蒸発を促進させた。８０℃の雰囲気温度を３０分保ったら、成形装置６を停止させて金型７を取り外し、金型７を１８０℃のオーブンにセットして残留溶剤を蒸発・乾燥させ、４５分後にオーブンから金型７を取り外して室温で冷却した。そして、金型７とシームレスベルト２０の熱膨張差を利用して金型７の内周面からシームレスベルト２０を剥離し、幅２６０ｍｍにカットして厚さ約１００μｍのシームレスベルト２０を得た。
【００２４】
評価
実施例で得られたシームレスベルト２０の周壁の厚さを縦横１０ｍｍ間隔で測定したところ、シームレスベルト２０の周壁の厚さの平均値は１００．１μｍ、最小値は９８．６μｍ、最大値は１０１．３μｍであった。また、外観上の欠点も認められなかった。
これに対し、比較例で得られたシームレスベルト２０の周壁の厚さを縦横１０ｍｍ間隔で計測したところ、シームレスベルト２０の周壁の厚さの平均値は９９．７μｍ、最小値は９５．２μｍ、最大値は１１０．３μｍであり、大きなばらつきが確認された。さらに、シームレスベルト２０の内周面に、高分子材料溶液４の飛び散りに起因すると見られる凸部が無数に認められた。
【００２５】
以上のように本発明によれば、金型内に高分子材料溶液を単に塗布するのではなく、高粘度の高分子材料溶液を線条に連続して吐出塗布するので、金型内で高分子材料溶液が波打ったり、表面に風紋状の模様が生じるのを抑制防止し、厚さ５０μｍ以上、特に８０μｍ以上、通常１ｍｍ以下の厚いシームレスベルトの肉厚の均一化を図ることができるという効果がある。また、各輪を被覆する弾性エラストマーの硬度が３０°Ｈｓ〜９０°Ｈｓの範囲なので、圧縮永久歪み特性が悪化したり、制振性が乏しくなるのを抑制することができる。
また、不安定な片持ちではなく、駆動輪と従動輪とで金型を安定状態に搭載するので、小径のみならず、２００ｍｍ以上の大径のシームレスベルトをも容易に遠心成形することができる。また、駆動輪のみで金型を回転させ、従動輪を従わせて回転させるので、駆動輪と従動輪との間に速度差の発生することがなく、簡易な構成で金型の上下動や微小なスリップを有効に防止することができる。さらに、駆動輪に対して従動輪が接近又は離隔するので、金型のメンテナンスや交換の便宜を図ったり、異なる仕様の金型に簡単に対処することが期待できる。
【図面の簡単な説明】
【図１】本発明に係るシームレスベルトの製造方法の実施形態を示す部分断面説明図である。
【図２】本発明に係るシームレスベルトの製造方法の実施形態における金型を示す正面説明図である。
【図３】図２の金型の側面説明図である。
【符号の説明】
１供給装置
２吐出ノズル
３ポンプ
４高分子材料溶液
６成形装置
７金型
８駆動装置
９従動装置
１０蓋
２０シームレスベルト[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a seamless belt used in an electrophotographic copying machine, a laser printer, and the like, and more particularly, to a method of manufacturing a seamless belt for intermediate transfer, paper conveyance, development, or fixing. .
[0002]
[Prior art]
Conventionally, when manufacturing a thick seamless belt, although not shown, first, a cylindrical cantilever mold is rotated at a low speed, and a nozzle of a supply device capable of moving forward and backward is advanced into the mold. The polymer material solution is sprayed and applied at a pressure of ² kgf / cm ² or more from one end portion to the other end portion of the inner peripheral surface of the rotating mold, and the material is dried to centrifugally mold the seamless belt. Then, the seamless belt is heated and cooled, and then the seamless belt is completed to a predetermined length.
[0003]
[Problems to be solved by the invention]
As described above, the conventional method of manufacturing a thick seamless belt supplies the polymer material solution at a high pressure from one end of the inner peripheral surface of the mold to the other end, and applies it by flying. As a result, the molecular material solution wavyly scattered, and as a result, the wall thickness of the seamless belt became uneven.
[0004]
The present invention has been made in view of the above problems, and prevents the polymer material solution from waving in the mold or generating a wind-like pattern on the surface, and has a thickness of 50 μm or more, particularly 80 μm or more. It is an object of the present invention to provide a method for producing a seamless belt which can achieve a uniform thickness of a thick seamless belt which is usually 1 mm or less.
[0005]
[Means for Solving the Problems]
In the present invention, in order to achieve the above-mentioned problem, a manufacturing method for forming a seamless belt by supplying a polymer material solution to a cylindrical and horizontally long mold,
A pair of lids that are detachably fitted to both ends of the mold, a plurality of drive wheels that contact and support one lower side of the outer peripheral surface of each lid, and the other lower side of the outer peripheral surface of each lid A plurality of driven wheels that support and rotate as the mold rotates,
A plurality of driven wheels can be slid horizontally and horizontally with respect to a plurality of driving wheels, and the outer peripheral surfaces of the plurality of driving wheels and the driven wheels have a hardness of 30 ° Hs to 90 ° Hs. Each coated with
The mold is rotated and heated from its surroundings, and the polymer material solution with high viscosity is continuously discharged from one end to the other end in the longitudinal direction in the mold, and uniformly distributed on the inner peripheral surface of the mold. It features leveling and continuous molding of the seamless belt by continuous mold heating .
[0006]
According to the present invention, instead of splashing the material solution, the polymer material solution is continuously dropped from the discharge nozzle and applied in a stable state. The thickness of the seamless belt can be suppressed or prevented from becoming uneven.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings. A seamless belt manufacturing method in the present embodiment forms a polymer material solution 4 from a discharge nozzle 2 of a supply device 1 as shown in FIG. The apparatus 6 is adapted to perform discharge application while continuously dripping at a predetermined discharge pressure from one end to the other end in the longitudinal direction in the mold 7 of the apparatus 6.
[0008]
As shown in FIG. 1, the supply device 1 includes various pumps 3 that are horizontally provided with elongated discharge nozzles 2 and a hopper 5 that supplies the polymer material solution 4 to the pumps 3. Then, based on the driving of a gear mechanism and a belt mechanism (not shown), the inner periphery of the mold 7 moves forward and backward with respect to the axial direction of the mold 7 as indicated by an arrow and is 20 to 30 mm away from the tip of the discharge nozzle 2. A liquid polymer material solution 4 having a high viscosity (1 poise or more and 100 poise or less at normal temperature) is applied to the surface while continuously hanging down on the streaks.
[0009]
The polymer material solution 4 is obtained by dissolving a polymer material such as PES or PET in various solvents such as NMP and adding carbon or the like. In addition to these, the polymer materials include polyester resins such as PBT and PEN, polyimide resins, polyamideimide resins, polyamide resins, fluororesins, polysulfones, polycarbonates, aramid resins, and polyether ether ketones. Among these, PAI and PES which are excellent in heat resistance, tensile strength and creep resistance are preferable. The polymer material may be either thermoplastic or thermosetting, and an appropriate material can be selected depending on the production method to be performed.
[0010]
As shown in FIGS. 2 and 3, the molding device 6 is capable of contacting and separating from a mold 7 for centrifugally molding the seamless belt 20, a drive device 8 for rotating the mold 7, and the drive device 8. And a driven device 9. The mold 7 is formed in a horizontally long cylindrical shape using various metals, and a smooth mirror surface processing, fluorine processing, or silicone resin processing is applied to the inner peripheral surface so that the seamless belt 20 can be easily removed. At the same time, matte black (not shown) is applied to the outer peripheral surface, and this black efficiently absorbs heat from the external heater. A ring-shaped lid 10 for preventing leakage of the polymer material solution 4 is detachably fitted to both ends of the mold 7, and an injection hole for the polymer material solution 4 is provided at the center of the lid 10. It has been.
[0011]
The drive device 8 covers various motors 11, a drive shaft 12 that rotates by driving the motor 11, a plurality of drive wheels 13 that are fitted to the drive shaft 12, and an outer peripheral surface of each drive wheel 13. In addition, it is composed of a heat-resistant and cylindrical elastic elastomer 14 that carries the vibration control function by contacting and supporting the lower part of the outer peripheral surface of the lid 10. The elastic elastomer 14 is made of, for example, silicone rubber, chloroprene rubber, or fluororubber having excellent oil resistance, solvent resistance, chemical resistance, weather resistance, heat resistance, and the like, and is 90 ° Hs or less, preferably 30 ° Hs to 90 °. It has a hardness of ° Hs. This is because if it is less than 30 ° Hs, the compression set characteristics deteriorate, and if it exceeds 90 ° Hs, the damping property becomes poor.
[0012]
As shown in FIG. 2, the driven device 9 includes a free driven shaft 15 that slides horizontally with respect to the drive shaft 12, a plurality of driven wheels 16 fitted to the driven shaft 15, and each driven wheel. 16 is composed of a heat-resistant and durable cylindrical elastic elastomer 14A that covers and covers the outer peripheral surface of the cover 10 and exerts a damping function by contacting and supporting the lower portion of the outer peripheral surface of the lid 10. Since the elastic elastomer 14A is the same as the elastic elastomer 14 of the driving device 8, the description thereof is omitted.
[0013]
Next, a specific manufacturing method of the seamless belt 20 will be described. First, the driving device 8 is driven to rotate the horizontal mold 7 at a high speed (for example, 900 to 1,000 rpm), and this mold is used. 7 is heated by an external heater to a predetermined temperature (although there is no particular limitation, about 70 ° C. to 100 ° C.), and the supply device 1 is moved forward and backward as appropriate with respect to the rotating mold 7 to end one end of the inner peripheral surface of the mold 7 The polymer material solution 4 is gradually dropped from the tip of the discharge nozzle 2 at a discharge pressure of 0.5 kgf / cm ² or less from the top to the other end, and gradually applied by discharge (discharge amount is, for example, 50 g in 10 seconds) Then, the polymer material solution 4 is uniformly leveled on the inner peripheral surface of the mold 7.
[0014]
Nanoha discharge pressure 0.5 kgf / cm ² or less, exceeds 0.5 kgf / cm ^2, it begins to occur waviness, moreover, depending on the viscosity of the polymer material solution 4, approximately greater than 0.8 kgf / cm ² This is because it causes scattering. When the polymer material solution 4 is completely leveled in this way, the mold 7 is continuously heated from the outside with an external heater to promote the viscosity reduction of the polymer material solution 4 and the evaporation of the solvent.
[0015]
When the mold 7 is heated for a predetermined time, the molding apparatus 6 is stopped, the mold 7 is removed, the mold 7 is set in a dryer, the residual solvent is evaporated and dried, the mold 7 is removed from the dryer and the room temperature is removed. Cool with air. Then, the seamless belt 20 naturally peels from the inner peripheral surface of the mold 7 due to a difference in thermal expansion between the mold 7 and the seamless belt 20 that is centrifugally molded. In the case where the mold 7 and the seamless belt 20 are in close contact with each other and are not separated from each other, the seamless belt 20 can be removed from the mold 7 by gradually peeling off the end of the seamless belt 20. After that, if both ends of the seamless belt 20 are cut to a predetermined length, a flexible cylindrical and thick seamless belt 20 can be obtained.
[0016]
According to the above method, since the high-viscosity polymer material solution 4 is continuously discharged and applied from the tip of the discharge nozzle 2, the polymer material solution 4 undulates in the mold 7 and the resulting seamless belt 20 is obtained. It is possible to extremely effectively suppress and prevent the occurrence of a wind-like pattern on the surface of the belt, and the wall thickness of the seamless belt 20 can be made extremely uniform. Therefore, the high-precision thick seamless belt 20 having a thickness of 50 μm or more, particularly 80 μm or more, and usually 1 mm or less can be suitably produced in a short time. Moreover, since the mold 7 is mounted in a stable state by the driving device 8 and the driven device 9 instead of being unstable cantilever, not only a small diameter but also a seamless belt 20 having a large diameter of 200 mm or more can be easily centrifugally formed. It becomes possible to do. Further, since the polymer material solution 4 is applied to the mold 7 that is rotating at a high speed, not at a low speed, quick leveling becomes very easy.
[0017]
Further, since the mold 7 is rotated only by the driving wheel 13 of the driving device 8 and the driven wheel 16 is rotated, the speed difference between the driving wheel 13 and the driven wheel 16 does not occur, and it is simple. With this configuration, it is possible to prevent the mold 7 from moving up and down and minute slips very effectively. Furthermore, since the driven device 9 approaches or separates from the drive device 8 in the direction of the arrow in FIG. 2, it is possible to facilitate maintenance and replacement of the mold 7, or to easily deal with differently used molds 7. I can expect. Furthermore, since the elastic elastomers 14 and 14A are excellent in heat resistance, long-term continuous use can be greatly expected even when the mold 7 is heated.
[0018]
In the above embodiment, the drive device 8 and the driven device 9 are used. However, the driven device 9 may be omitted and a pair of drive devices 8 may be used. Further, the driven device 9 can be brought into contact with and separated from the drive device 8, but the drive device 8 can be brought into contact with and separated from the driven device 9, and the drive device 8 and the driven device 9 can be brought into contact with and separated from each other. Also good. The elastic elastomers 14 and 14A of the driving wheel 13 and the driven wheel 16 are brought into contact with the lower part of the outer peripheral surface of the lid 10, but the elastic elastomers 14 and 14A of the driving wheel 13 and the driven wheel 16 are attached to the lower part of the outer peripheral surface of the mold 7. You may make it contact. The seamless belt 20 may be semiconductive or not. Further, after the polymer material solution 4 is completely leveled, the mold 7 that rotates at a high speed is rotated at a low speed (for example, 200 to 250 rpm) during drying to release the solvent from the centrifugal force and discharge it. Time can be shortened and the thickness of the seamless belt 20 can be made more uniform.
[0019]
【Example】
Hereinafter, polymer material solutions, examples, comparative examples, and evaluation of the seamless belt manufacturing method according to the present invention will be described in order.
Preparation of polymer material solution First, an equivalent of trimellitic anhydride and 4,4'-diaminodiphenylmethane was dissolved in dimethylacetamide and heated to react to a solid content concentration (substantially fully ring-closed polyamideimide) of 28% by weight. Aromatic polyamideimide was prepared. Dimethylacetamide was added thereto to obtain a polyamideimide solution having a solid content concentration of 15% by weight and a solid content specific gravity of 1.2.
Next, as a carbon filler, “Special Black MONARCH 120” manufactured by Cabot was mixed with dimethylacetamide so as to be 15% by weight. Then, 20 parts by weight of the carbon filler mixed solution is added to 100 parts by weight of the polyamideimide solution dispersed in the beads mill for 1 hour, and mixed with the beads mill for 1 hour to obtain a polyamideimide-carbon black mixed solution. It was.
[0020]
Example First, a lid (inner diameter 170 mm, outer diameter 220 mm) 10 was fitted to a mold (inner diameter 200 mm, outer diameter 220 mm, length 400 mm) 7, and this mold 7 was mounted and supported on the molding apparatus 6. When the mold 7 is thus mounted, the driving device 8 is driven to rotate the horizontal mold 7 at a high speed of 1,000 rpm, and the supply device 1 is appropriately moved with respect to the rotating mold 7 to move the inside of the mold 7. A polymer material solution 4 composed of a polyamideimide-carbon black mixed solution is discharged from one end of the peripheral surface to the other end while continuously dropping from the tip of the discharge nozzle (φ5 mm) 2 at a discharge pressure of 0.1 kgf / cm ^2. The polymer material solution 4 was uniformly leveled on the inner peripheral surface of the mold 7. In this case, the supply amount of the polymer material solution 4 is 215 g.
[0021]
Next, the atmosphere temperature of the mold 7 was maintained at 80 ° C. with a hot air warm air machine, and the viscosity reduction of the polymer material solution 4 and the evaporation of the solvent were promoted. When the atmosphere temperature of 80 ° C. is maintained for 30 minutes, the molding apparatus 6 is stopped, the mold 7 is removed, the mold 7 is set in an oven at 180 ° C. to evaporate and dry the residual solvent, and after 45 minutes, the gold is removed from the oven. The mold 7 was removed and air cooled at room temperature. Then, the seamless belt 20 was peeled from the inner peripheral surface of the mold 7 using the difference in thermal expansion between the mold 7 and the seamless belt 20 and cut to a width of 260 mm to obtain a seamless belt 20 having a thickness of about 100 μm.
[0022]
Comparative Example First, the same lid 10 was set on the same mold 7 as in the example, and this mold 7 was mounted and supported on the molding apparatus 6. When the mold 7 is mounted, the driving device 8 is driven to rotate the horizontal mold 7 at a high speed of 1,000 rpm, and the supply device 1 is appropriately moved with respect to the rotating mold 7 to move the inner periphery of the mold 7. While the polymer material solution 4 composed of a polyamideimide-carbon black mixed solution is continuously ejected from one end portion of the surface to the other end portion at a discharge pressure of 2.0 kgf / cm ² from the tip portion of the discharge nozzle (φ0.2 mm) 2. The polymer material solution 4 was leveled on the inner peripheral surface of the mold 7 by spray coating. In this case, the supply amount of the polymer material solution 4 is 215 g.
[0023]
Next, the atmosphere temperature of the mold 7 was kept at 80 ° C. with a hot air warm air machine, and the viscosity reduction of the polymer material solution 4 and the evaporation of the solvent were promoted. When the atmosphere temperature of 80 ° C. is maintained for 30 minutes, the molding apparatus 6 is stopped, the mold 7 is removed, the mold 7 is set in an oven at 180 ° C. to evaporate and dry the residual solvent, and after 45 minutes, the gold is removed from the oven. The mold 7 was removed and cooled at room temperature. Then, the seamless belt 20 was peeled from the inner peripheral surface of the mold 7 using the difference in thermal expansion between the mold 7 and the seamless belt 20 and cut to a width of 260 mm to obtain a seamless belt 20 having a thickness of about 100 μm.
[0024]
When the thickness of the peripheral wall of the seamless belt 20 obtained in the evaluation examples was measured at intervals of 10 mm in length and width, the average value of the peripheral wall thickness of the seamless belt 20 was 100.1 μm, the minimum value was 98.6 μm, and the maximum value. Was 101.3 μm. In addition, no defects in appearance were observed.
On the other hand, when the thickness of the peripheral wall of the seamless belt 20 obtained in the comparative example was measured at 10 mm vertical and horizontal intervals, the average value of the peripheral wall thickness of the seamless belt 20 was 99.7 μm, the minimum value was 95.2 μm, The maximum value was 110.3 μm, and a large variation was confirmed. Furthermore, innumerable convex portions that are considered to be caused by scattering of the polymer material solution 4 were recognized on the inner peripheral surface of the seamless belt 20.
[0025]
As described above, according to the present invention, the polymer material solution is not simply applied to the mold, but the high-viscosity polymer material solution is continuously discharged and applied to the filaments. It is possible to prevent the molecular material solution from undulating and the occurrence of a wind-like pattern on the surface, and to achieve uniform thickness of a thick seamless belt having a thickness of 50 μm or more, particularly 80 μm or more, and usually 1 mm or less. effective. Moreover, since the hardness of the elastic elastomer which coat | covers each ring | wheel is the range of 30 degrees Hs-90 degrees Hs, it can suppress that a compression set characteristic deteriorates or a damping property becomes scarce.
Moreover, since the mold is stably mounted with the driving wheel and the driven wheel instead of an unstable cantilever, not only a small diameter but also a seamless belt having a large diameter of 200 mm or more can be easily centrifugally formed. . In addition, since the mold is rotated only by the driving wheel and the driven wheel is rotated, there is no speed difference between the driving wheel and the driven wheel, and the mold can be moved up and down with a simple configuration. A minute slip can be effectively prevented. Furthermore, since the driven wheel approaches or separates from the driving wheel, it can be expected to facilitate the maintenance and replacement of the mold or easily deal with the mold having different specifications.
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional explanatory view showing an embodiment of a seamless belt manufacturing method according to the present invention.
FIG. 2 is an explanatory front view showing a mold in an embodiment of a seamless belt manufacturing method according to the present invention.
FIG. 3 is an explanatory side view of the mold of FIG. 2;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Supply apparatus 2 Discharge nozzle 3 Pump 4 Polymer material solution 6 Molding apparatus 7 Mold 8 Drive apparatus 9 Drive apparatus 10 Lid 20 Seamless belt

Claims

A method for producing a seamless belt in which a polymer material solution is supplied to a cylindrical and horizontally long mold to form a seamless belt,
A pair of lids that are detachably fitted to both ends of the mold, a plurality of drive wheels that contact and support one lower side of the outer peripheral surface of each lid, and the other lower side of the outer peripheral surface of each lid A plurality of driven wheels that support and rotate as the mold rotates,
A plurality of driven wheels can be slid horizontally and horizontally with respect to a plurality of driving wheels, and the outer peripheral surfaces of the plurality of driving wheels and the driven wheels have a hardness of 30 ° Hs to 90 ° Hs. Each coated with
The mold is rotated and heated from its surroundings, and the polymer material solution with high viscosity is continuously discharged from one end to the other end in the longitudinal direction in the mold, and uniformly distributed on the inner peripheral surface of the mold. A method for producing a seamless belt, characterized in that the seamless belt is centrifugally molded by leveling and heating the mold .