JP3587351B2

JP3587351B2 - Method for producing aluminum alloy support for lithographic printing plate

Info

Publication number: JP3587351B2
Application number: JP33286098A
Authority: JP
Inventors: 宏和澤田; 博和榊; 英樹三輪
Original assignee: Fuji Photo Film Co Ltd
Current assignee: Fujifilm Holdings Corp
Priority date: 1998-11-24
Filing date: 1998-11-24
Publication date: 2004-11-10
Anticipated expiration: 2018-11-24
Also published as: JP2000158099A

Description

【０００１】
【発明の属する技術分野】
本発明は、平版印刷版用支持体の製造方法に関し、特に、アルミニウム合金を溶解した溶湯を連続鋳造圧延及び冷間圧延を行って０．１〜０．５ｍｍの厚みに仕上げ、表面に粗面化処理を行うことで平版印刷版用支持体を製造する方法に
関する。
【０００２】
【従来の技術】
アルミニウム合金を１対の冷却ローラの間に供給し、その冷却ローラによって、アルミニウム合金溶湯を凝固させてアルミニウム板を鋳造する方法については、米国特許第４９０５３号や同第２、７９０、２１５号明細書、カナダ特許第６１９、４９１号明細書、特公昭５１−１５９６８号公報、特開昭５１−８９８２７号、同５８−２０９４４９号各公報等に開示されている。しかしこれらの方法では平版印刷版支持体用途の表面面質の優れたアルミニウム合金板を作ることは出来なかった。
本発明人らによってアルミニウム合金を連続鋳造して平版印刷版用支持体を製造する方法（特開平３−７９７９８号公報）や３ｍｍ以下に連続鋳造して平版印刷版用支持体を製造する方法（特開平７−１３８７１７号公報）が提案されている。また、特開平９−１６８８４３号公報には、すじ故障発生防止のため冷却ローらと鋳造ノズルの間隔を一定にする方法が提案されており、その中で、冷却ローラに離型材を塗布する方法が開示されている。
上記の特開平３−７９７９８号及び同７−１３８７１７号各公報の方法によって連続鋳造板から平版印刷版用アルミニウム合金支持体を作ることが出来るが、連続鋳造の途中で鋳造板が冷却ローラに固着して鋳造板が不良となり、結果として、得率を低下させる不具合があった。また、上記特開平９−１６８８４３号公報に開示された方法も、離型材塗布量の変動が起こったとき、鋳造板が冷却ローラに固着して鋳造板が不良となり、結果として、得率を低下させる不具合があった。また特開平４−３７１５４４号公報は磁気ディスク基板用途のアルミニウムを連続鋳造する際の離型剤の塗布量を限定しているが、塗布量が多すぎるため、平版印刷版用途に適用すると鋳造板の結晶組織が粗大になってしまうという不具合があった。
【０００３】
【発明が解決しようとする課題】
本発明は連続鋳造の途中で鋳造板が冷却ローラに固着して鋳造板が不良となり、結果として、得率を低下させる不具合を解決し、安定して平版印刷版用アルミニウム合金支持体を製造する方法を提供することにある。
本発明者らは鋭意検討の結果、連続鋳造の途中で鋳造板が冷却ローラに固着して鋳造板が不良となる原因が冷却ローラに塗布する離型材量の変動にあることを見出して、本発明即ち鋳造板と冷却ローラ固着を防止し、安定して平版印刷版用アルミニウム合金支持体を製造する方法を提供することにある。
【０００４】
【課題を解決するための手段】
上記課題は、以下に述べる本発明によって達成された
即ち、上記課題は、ローラ表面に離型材として微細な粒子を含む懸濁液を連続的または断続的に塗布した１対の冷却ローラの間に、溶湯供給ノズルを介してアルミニウム合金溶湯を供給し、その冷却ローラによって、アルミニウム溶湯を凝固させつつ圧延を行う、双ローラ式連続鋳造装置を用いて厚さ１０ｍｍ〜１ｍｍのアルミニウム鋳造板を連続鋳造し、冷間圧延により０．１〜０．５ｍｍの厚みに仕上げて、平版印刷版用アルミニウム合金支持体を製造する方法において、
前記離型材中に含まれる微細な粒子が、
平均粒径＝０．７〜１．５μｍであり、
メジアン径＝０．５〜１．２μｍであり、
０．２μｍ以下の粒子が粒子全体の５％未満であり、
０．４μｍ以下の粒子が粒子全体の１０％未満であり。
２μｍ以上の粒子が１０％未満であり、
３μｍ以上の粒子が５％未満であり、かつ
上記離型材の冷却ローラ上への塗布量が６０〜１２００ｍｇ／ｍ^２であることを特徴とする平版印刷版用アルミニウム合金支持体板の製造方法によって達成された。
【０００５】
【発明の実施の形態】
通常平版印刷版用アルミニウム合金支持体の製造方法としては、下記の方法が使用されている。
所定の成分に調整されたアルミニウム合金溶湯を常法に従い清浄化処理を施し、鋳造する。清浄化処理には、溶湯中の水素などの不要なガスを除去するために、フラックス処理、Ａｒガス、Ｃｌガス等を使った脱ガス処理や、セラミックチューブフィルタ、セラミックフォームフィルタ、等のいわゆるリジッドメディアフィルターや、アルミナフレーク、アルミナボール等を濾材とするフィルタや、グラスクロスフィルター等を使ったフィルタリング。あるいは、脱ガスとフィルタリングを組み合わせた処理が行われる。これらの清浄化処理は、溶湯中の、非金属介在物、酸化物、等の異物による欠陥、溶湯にとけ込んだガスによる欠陥を防ぐために、実施されることが望ましい。
以上のように、清浄化処理を施された溶湯を使って、鋳造を行う。鋳造方法に関しては、ＤＣ鋳造法に代表される、固定鋳型を用いる方法と、連続鋳造法に代表される、駆動鋳型を用いる方法がある。工程を複雑にすることなく、低コスト、短納期でアルミニウム支持体を製造するためには、連続鋳造法に代表される、駆動鋳型を用いる方法が望ましい。
【０００６】
連続鋳造法には、ハンター法、３Ｃ法に代表される、冷却ロールを用いた方法、ハズレー法、アルスイスキャスターＩＩ型に代表される冷却ベルト、冷却ブロックを用いた方法が、工業的に行われている。連続鋳造法に関しては、本発明者らによって、特開平３−７９７９８号、特開平５−２０１１６６号、特開平５−１５６４１４号、特開平６−２６２２０３号、特開平６−１２２９４９号、特開平６−２１０４０６号、特開平６−２６２３０８号各公報等に開示されている。
連続鋳造を行った場合、例えば、ハンター法等の冷却ロールを用いると板厚１〜１０ｍｍの鋳造板を直接連続鋳造圧延でき、熱間圧延の工程を省略できるメリットが得られる。また、ハズレー法等の冷却ロールを用いると、板厚１０〜５０ｍｍの鋳造板が鋳造でき、一般的に、鋳造直後に熱間圧延ロールを配置し連続的に圧延することで、板厚１〜１０ｍｍの連続鋳造圧延板が得られる。鋳造直後に熱間圧延ローラを必要としない点で、ハンター法等の冷却ローラを用いる方法が工程がよりシンプルであり、低コストで平版印刷版用アルミニウム合金支持体を提供できる点で優れており、本発明はこの冷却ローラを用いる方法を採用している。
冷却ローラを用いる場合、ローラに離型材を塗布する方法が知られている。離型材としては、アルミニウムと冷却ローラの離型性を向上できる材質であれば限定されないが、カーボングラファイトを主成分とした物、硫化モリブデンを主成分とした物、窒化硼素を主成分とした物、酸化亜鉛を主成分とした物等が使用できる。離型材の塗布方法としては、スプレイによる方法、ロールコータによる方法、布や多孔質材料を介して塗布する方法などが使用できる。離型材が少ないと冷却ローラと鋳造板が固着し、固着した部分は、結晶組織が極めて不均一になるため、冷間圧延、熱処理、冷間圧延を行って平版印刷版支持体用アルミ合金板にし、粗面化処理を行うと、外観が不均一になって得率が低下する。また、固着がひどい場合には、鋳造が不可能となり、その場合の損失は莫大な物となる。一方離型材の量が多すぎると、冷却ローラとアルミニウム溶湯間の熱伝達率が低下し、鋳造板の結晶組織が粗大になるという不具合が生じる。鋳造板の結晶組織が粗大になるとその後、冷間圧延と中間焼鈍を行って０．１〜０．５ｍｍの板に仕上げてもその結晶組織はやはり粗大になり、平版印刷版用支持体に仕上げたときに、面質ザラツキやストリークといった外観不良が発生する不具合となる。本発明者らは、鋭意検討の結果、離型材中に含まれる微粒子の径と粒度分布が固着防止と結晶組織の微細化に有効であること及び離型材の塗布量を６０〜１２００ｍｇ／ｍ^２の範囲内にすることで更に望ましい結果が得られることを見出したのである。
【０００７】
板厚１〜１０ｍｍの連続鋳造圧延板は通常その後の冷間圧延の途中で、中間焼鈍と呼ばれる熱処理を行って結晶組織を均一微細にするとともに、引っ張り強度を適正なものとする。
通常、所定の厚さ０．１〜０．５ｍｍに仕上げられたアルミニウム板は平面性を改善するために、ローラレベラ、テンションレベラ等の矯正装置によって、平面性を改善しても良い。また、板巾を所定の巾に加工するため、スリッタラインを通すことも通常行われる。
このようにして作られたアルミニウム板は表面に粗面化処理や陽極酸化処理等の表面処理を行い、感光層を塗布して平版印刷板とすることが出来る。粗面化処理には、機械的粗面化、化学的粗面化、電気化学的粗面化が単独又は組み合わせて行われる。
また、通常アルミニウム板の表面の耐磨耗性を高めるために陽極酸化処理が施される。アルミニウム板の陽極酸化処理に用いられる電解質としては酸化皮膜を形成するものならば、いかなるものでも使用することができる。一般には硫酸、リン酸、シュウ酸、クロム酸、またはそれらの混合液が用いられる。このようにして得られた平版印刷版用支持体の上には、従来より知られている感光層を設けて、感光性平版印刷版を得ることができる。この感光層中に用いられる感光性物質は特に限定されるものではなく、通常、感光性平版印刷版に用いられているものを使用できる。
【０００８】
本発明では、双ローラ式連続鋳造装置を用いて厚さ１０ｍｍ〜１ｍｍの連続鋳造板を鋳造し、途中で熱処理を行い、冷間圧延で０．１〜０．５ｍｍの厚みに仕上げて、平版印刷版用アルミニウム合金支持体を製造する際、冷却ローラに塗布する離型在中に含まれる潤滑成分粒子のサイズと、粒度分布を一定範囲にすること、更にのぞましくは、冷却ローラ表面における離型材の塗布量を６０〜１２００ｍｇ／ｍ^２にすることによって、連続鋳造の途中で鋳造板が冷却ローラに固着して鋳造板が不良となる不具合を解消すると共に、鋳造板の結晶組織を均一で微細に出来るので圧延・熱処理を行って薄板に仕上げて平版印刷版にしたときに外観の優れた平版印刷版用支持体にすることが出来る。
【０００９】
【実施例】
実施例１〜３
図１に示した連続鋳造圧延装置を用いて、次のように鋳造板３６を連続鋳造圧延した。
まず溶解保持炉１２でＦｅ０．３％、Ｓｉ０．１％、Ｃｕ０．０１５％、残りはＡｌと不可避不純物になるように溶湯２２を調整し、温度７９０℃に保持した。溶解炉１２を傾けて樋１４に溶湯を注ぎ、溶湯供給ノズル１６から一対の冷却ローラ１８、１８間に吐出させ、冷却ローラ１８、１８間で凝固・冷却・圧延しながら所定の厚さの鋳造板３６を連続鋳造圧延した。冷却ローラの間隔をかえることで色々な厚みの板を鋳造することが出来る。本実施例では、鋳造板厚を３ｍｍとして、実施例と比較例を作成した。溶湯の液面は、センサ３２と制御装置３４を用いて溶解炉傾動用モータ２４を制御する事で一定に保たれる。鋳造板３６はコイラ２０で巻き上げたり、必要に応じてカッター３８で切断することが出来る。離型材塗布装置４６を使って冷却ローラの表面に離型材の塗布を行う。本実施例、比較例では、離型材はカーボングラファイトを主成分とした物、塗布方法はスプレイ方式を使用した。
Ｔｉの供給は、例えばＡｌ−Ｔｉ（５％）−Ｂ（１％）の合金ワイヤ２３を結晶微細化材として、樋１４中の溶湯２２に供給する事が出来る。供給速度を変えることで、溶湯２２中のＴｉ濃度｛Ｔｉ｝を変えることが出来る。あるいは、溶解保持炉１２中に、Ａｌ−Ｔｉ（５％）の母合金ブロックや、Ａｌ−Ｔｉ（５％）−Ｂ（１％）の母合金ブロックを必要量添加することによっても可能である。Ｔｉ量ゼロでは結晶微細化が行えず、Ｔｉ量が多すぎるのは経済上好ましくない。Ｔｉ量は、０．００５〜０．０４％添加するのが望ましい。本実施例、比較例では、Ｔｉ量を０．０２％とした。
【００１０】
連続鋳造された板はその後冷間圧延機５０の圧延ロール５６間で所定の厚みまで圧延される。更に、連続焼鈍装置６０またはバッチ式焼鈍装置７０で熱処理され、再度冷間圧延機５０の圧延ローラ５６間で所定の厚み０．１ｍｍ〜０．５ｍｍまで圧延される。本実施例では、実施例、比較例いずれも板厚２ｍｍまで冷間圧延で薄くした後、バッチ焼鈍装置を使い、５５０℃×１０時間保持の熱処理を行ってから、再度冷間圧延機で厚み０．２４ｍｍに仕上げた。矯正機８０の矯正ローラ８６によって平面性を改善し、必要に応じて耳部をスリッタ８８で所定の巾まで切除しても良い。このようにして平版印刷版用Ａｌ板が製造される。
このようにして出来たアルミニウム板に粗面化処理、陽極酸化処理、感光層の塗布・乾燥を行って、平版印刷版とすることが出来る。ここでは、粒度分布、平均粒径の異なる離型材を用いて、本発明の方法及び比較例を作製した。実施例比較例共に連続的に３００Ｋｇ鋳造する実験を行い、鋳造板と冷却ローラ間に固着が発生するかどうか、鋳造板の結晶組織、０．２４ｍｍに仕上げて粗面化処理と陽極酸化処理を行つたときの外観について評価した。結果を表１に示した。
【００１１】
【表１】

【００１２】
表１に示すように、本発明の実施例は、固着が発生せず、かつ鋳造板の結晶組織を微細に出来るので外観の優れた平版印刷版用支持体にすることが出来る。
実施例４〜７
上記実施例１〜３、比較例１〜３と同様の方法で、今度は離型材の塗布量を変更したサンプル作製して本発明の実施例と比較例を作って評価した。結果を表２に示した。
【００１３】
【表２】

【００１４】
表２に示すように、本発明の実施例は固着が発生せず、かつ、鋳造板の結晶組織が粗大にならないので外観の優れた平版印刷版用支持体にすることが出来る。一方比較例は、固着の発生防止と結晶粒の微細化及び平版印刷版用支持体に仕上げたときの外観を両立することが出来なかった。
【００１５】
【発明の効果】
本発明では、双ローラ式連続鋳造装置を用いて厚さ１０ｍｍ〜１ｍｍの連続鋳造板を鋳造し、途中で熱処理を行い、冷間圧延で０．１〜０．５ｍｍの厚みに仕上げて、平版印刷版用アルミニウム合金支持体を製造する際、冷却ローラに塗布する離型在中に含まれる潤滑成分粒子のサイズと、粒度分布を一定範囲にすること、及び冷却ローラ表面における離型材の塗布量を６０〜１２００ｍｇ／ｍ^２にすることによって、冷却ローラと鋳造板の熱伝導を低下させることなく、剥離性を向上出来るので、連続鋳造の途中で鋳造板が冷却ローラに固着して鋳造板が不良となる不具合を解消すると共に、鋳造板の結晶組織を均一で微細に出来るので圧延・熱処理を行って薄板に仕上げて平版印刷版にしたときに外観の優れた平版印刷版用支持体にすることが出来る。
【図面の簡単な説明】
【図１】本発明の実施態様の１例である連続鋳造圧延装置の全体構成を示す。
【図２】本発明の実施態様の１例である冷間圧延装置の全体構成を示す。
【図３】本発明の実施態様の熱処理工程の１例である連続焼鈍装置の全体構成を示す。
【図４】本発明の実施態様の熱処理工程の別の１例であるバッチ焼鈍装置の全体構成を示す。
【図５】本発明の実施態様の１例である矯正装置の全体構成を示す。
【図６】望ましい離型材の粒度分布の１例を示す図である。
【符号の説明】
１０連続鋳造圧延装置
１２溶解保持炉
１４樋
１６溶湯供給ノズル
１８回転式冷却ローラ
２２溶湯
３２液面センサ
３６鋳造板
３７圧延板
３８カッター
４６離型材塗布装置
５０冷間圧延機
５６圧延ローラ
５８バックアップローラ
８０矯正装置
８６矯正ローラ[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing a support for a lithographic printing plate, and in particular, a molten metal in which an aluminum alloy is melted is subjected to continuous casting rolling and cold rolling to a thickness of 0.1 to 0.5 mm, and the surface is roughened. The present invention relates to a method for producing a lithographic printing plate support by carrying out a chemical treatment.
[0002]
[Prior art]
US Pat. No. 4,905,53 and US Pat. No. 2,790,215 disclose a method of casting an aluminum plate by supplying an aluminum alloy between a pair of cooling rollers and solidifying an aluminum alloy melt by the cooling rollers. And Canadian Patent Nos. 619 and 491, JP-B-51-15968, JP-A-51-89827 and JP-A-58-209449. However, these methods have failed to produce an aluminum alloy plate having excellent surface quality for use in a lithographic printing plate support.
A method for producing a lithographic printing plate support by continuously casting an aluminum alloy by the present inventors (Japanese Patent Laid-Open No. 3-79798) and a method for producing a lithographic printing plate support by continuously casting to 3 mm or less ( JP-A-7-138717) has been proposed. Further, Japanese Patent Application Laid-Open No. 9-168843 proposes a method for keeping a gap between a cooling roll and a casting nozzle constant in order to prevent the occurrence of a streak failure, in which a method of applying a release material to a cooling roller is proposed. Is disclosed.
An aluminum alloy support for a lithographic printing plate can be produced from a continuous casting plate by the methods described in JP-A-3-79798 and JP-A-7-138717. However, the casting plate adheres to a cooling roller during continuous casting. As a result, the cast plate became defective, and as a result, there was a problem that the yield was reduced. Further, the method disclosed in Japanese Patent Application Laid-Open No. Hei 9-168843 also discloses that when the release amount of the release material fluctuates, the cast plate adheres to the cooling roller and the cast plate becomes defective, and as a result, the yield decreases. There was a defect to do. Japanese Patent Application Laid-Open No. Hei 4-371544 limits the amount of a release agent applied when aluminum is continuously cast for use as a magnetic disk substrate. However, the amount of the release agent is too large. There was a problem that the crystal structure became coarse.
[0003]
[Problems to be solved by the invention]
The present invention solves the problem that the cast plate adheres to the cooling roller during the continuous casting and the cast plate becomes defective, thereby lowering the yield, and stably manufactures an aluminum alloy support for a lithographic printing plate. It is to provide a method.
As a result of intensive studies, the present inventors have found that the cause of the failure of the cast plate due to the cast plate sticking to the cooling roller during continuous casting is the fluctuation of the amount of release material applied to the cooling roller. It is an object of the present invention to provide a method for stably producing an aluminum alloy support for a lithographic printing plate by preventing sticking of a casting plate to a cooling roller and stably.
[0004]
[Means for Solving the Problems]
The above object has been achieved by the present invention described below. That is, the above object is achieved between a pair of cooling rollers in which a suspension containing fine particles is continuously or intermittently applied to a roller surface as a release material. A 10 mm to 1 mm thick aluminum casting plate is continuously cast using a twin-roller continuous casting apparatus, in which a molten aluminum alloy is supplied through a molten metal supply nozzle, and the aluminum alloy is rolled while being solidified by its cooling roller. Then, in a method of producing an aluminum alloy support for a lithographic printing plate by finishing to a thickness of 0.1 to 0.5 mm by cold rolling,
Fine particles contained in the release material,
Average particle size = 0.7 to 1.5 μm,
Median diameter = 0.5 to 1.2 μm,
Particles less than 0.2 μm account for less than 5% of the total particles,
Less than 10% of particles having a size of 0.4 μm or less.
Less than 10% of particles of 2 μm or more;
A method for producing an aluminum alloy support plate for a lithographic printing plate, characterized in that particles of 3 μm or more are less than 5% and the amount of the release material applied on the cooling roller is 60 to 1200 mg / m ² . Achieved.
[0005]
BEST MODE FOR CARRYING OUT THE INVENTION
Usually, the following method is used as a method for producing an aluminum alloy support for a lithographic printing plate.
The aluminum alloy melt adjusted to a predetermined component is subjected to a cleaning treatment according to a conventional method, and is cast. The cleaning treatment includes flux treatment, degassing treatment using Ar gas, Cl gas, and the like, and so-called rigid tubes such as ceramic tube filters and ceramic foam filters in order to remove unnecessary gases such as hydrogen in the molten metal. Media filters, filters using alumina flakes, alumina balls, etc. as filter media, and filtering using glass cloth filters. Alternatively, a process combining degassing and filtering is performed. These cleaning treatments are desirably carried out in order to prevent defects due to foreign substances such as nonmetallic inclusions and oxides in the molten metal and defects due to gas dissolved in the molten metal.
As described above, casting is performed using the molten metal subjected to the cleaning treatment. As for the casting method, there are a method using a fixed mold typified by a DC casting method and a method using a driving mold typified by a continuous casting method. In order to manufacture an aluminum support at a low cost and with a short delivery time without complicating the process, a method using a driving mold typified by a continuous casting method is desirable.
[0006]
In the continuous casting method, a method using a cooling roll, represented by the Hunter method and the 3C method, a Hadley method, a method using a cooling belt represented by an Al Swiss Caster II type, and a method using a cooling block are industrially practiced. Has been done. Regarding the continuous casting method, the inventors of the present invention disclosed in JP-A-3-79798, JP-A-5-201166, JP-A-5-156414, JP-A-6-262203, JP-A-6-122949, and JP-A-6-122949. -210406 and JP-A-6-262308.
In the case of performing continuous casting, for example, using a cooling roll such as a Hunter method can directly and continuously cast and roll a cast plate having a thickness of 1 to 10 mm, and has an advantage that the step of hot rolling can be omitted. When a cooling roll such as the Hasley method is used, a cast plate having a plate thickness of 10 to 50 mm can be cast. In general, immediately after casting, a hot-rolling roll is disposed and continuously rolled, so that the plate thickness is 1 to 1 mm. A 10 mm continuous cast rolled plate is obtained. The method using a cooling roller such as the Hunter method is superior in that it does not require a hot-rolling roller immediately after casting, and the process is simpler and the aluminum alloy support for lithographic printing plates can be provided at low cost. The present invention employs a method using this cooling roller.
When a cooling roller is used, a method of applying a release material to the roller is known. The release material is not limited as long as it is a material capable of improving the releasability of aluminum and the cooling roller, but a material mainly composed of carbon graphite, a material mainly composed of molybdenum sulfide, and a material mainly composed of boron nitride And those containing zinc oxide as a main component. As a method of applying the release material, a method using a spray, a method using a roll coater, a method using a cloth or a porous material, or the like can be used. If the release material is small, the cooling roller and the cast plate will adhere to each other, and since the crystal structure of the adhered portion becomes extremely non-uniform, cold rolling, heat treatment, and cold rolling are applied to the aluminum alloy plate for lithographic printing plate support. When a roughening treatment is performed, the appearance becomes uneven and the yield decreases. Further, if the sticking is severe, casting becomes impossible, and the loss in that case becomes enormous. On the other hand, if the amount of the release material is too large, the heat transfer coefficient between the cooling roller and the molten aluminum decreases, and the crystal structure of the cast plate becomes coarse. When the crystal structure of the cast plate becomes coarse, cold rolling and intermediate annealing are then performed to obtain a plate of 0.1 to 0.5 mm. In such a case, an appearance defect such as surface roughness or streak occurs. The present inventors have made intensive studies and found that the diameter and particle size distribution of the fine particles contained in the release material are effective for preventing sticking and refining the crystal structure, and the coating amount of the release material was 60 to 1200 mg / m ^2. It has been found that more desirable results can be obtained by setting the ratio within the range.
[0007]
A continuous cast rolled sheet having a sheet thickness of 1 to 10 mm is usually subjected to a heat treatment called intermediate annealing during the subsequent cold rolling to make the crystal structure uniform and fine, and to make the tensile strength appropriate.
Usually, in order to improve the flatness of the aluminum plate finished to a predetermined thickness of 0.1 to 0.5 mm, the flatness may be improved by a straightening device such as a roller leveler or a tension leveler. Further, in order to process the board width to a predetermined width, it is usually performed to pass through a slitter line.
The aluminum plate thus produced can be subjected to a surface treatment such as a surface roughening treatment or an anodic oxidation treatment, and a photosensitive layer can be applied to obtain a lithographic printing plate. In the surface roughening treatment, mechanical surface roughening, chemical surface roughening, and electrochemical surface roughening are performed alone or in combination.
Also, anodizing is usually performed to increase the abrasion resistance of the surface of the aluminum plate. As the electrolyte used for the anodic oxidation treatment of the aluminum plate, any electrolyte that forms an oxide film can be used. Generally, sulfuric acid, phosphoric acid, oxalic acid, chromic acid, or a mixture thereof is used. A conventionally known photosensitive layer is provided on the lithographic printing plate support thus obtained to obtain a photosensitive lithographic printing plate. The photosensitive substance used in the photosensitive layer is not particularly limited, and those usually used for photosensitive lithographic printing plates can be used.
[0008]
In the present invention, a continuous cast plate having a thickness of 10 mm to 1 mm is cast using a twin-roller continuous casting apparatus, heat-treated on the way, and finished to a thickness of 0.1 to 0.5 mm by cold rolling. When manufacturing an aluminum alloy support for a printing plate, the size and particle size distribution of the lubricating component particles contained in the release roller applied to the cooling roller should be within a certain range, more preferably, the surface of the cooling roller. By setting the coating amount of the release material in the above to 60 to 1200 mg / m ² , the problem that the cast plate is fixed to the cooling roller during the continuous casting and the cast plate becomes defective is eliminated, and the crystal structure of the cast plate is reduced. Since it can be made uniform and fine, it can be made into a lithographic printing plate support having excellent appearance when it is rolled and heat treated to be finished into a thin plate to form a lithographic printing plate.
[0009]
【Example】
Examples 1-3
Using the continuous casting and rolling device shown in FIG. 1, the cast plate 36 was continuously cast and rolled as follows.
First, the melt 22 was adjusted in the melting and holding furnace 12 so that Fe 0.3%, Si 0.1%, and Cu 0.015%, and the remainder became Al and inevitable impurities, and the temperature was maintained at 790 ° C. The molten metal is poured into the gutter 14 by inclining the melting furnace 12, discharged from the molten metal supply nozzle 16 between the pair of cooling rollers 18, and cast into a predetermined thickness while solidifying, cooling, and rolling between the cooling

rollers

18, 18. The plate 36 was continuously cast and rolled. By changing the interval between the cooling rollers, plates of various thicknesses can be cast. In the present example, an example and a comparative example were prepared with a cast plate thickness of 3 mm. The liquid level of the molten metal is kept constant by controlling the melting furnace tilting motor 24 using the sensor 32 and the control device 34. The cast plate 36 can be wound up by the coiler 20 or cut by a cutter 38 if necessary. The release material is applied to the surface of the cooling roller by using the release material application device 46. In this example and the comparative example, the release material used was a material containing carbon graphite as a main component, and the spray method was used as a coating method.
Ti can be supplied to the molten metal 22 in the gutter 14 using, for example, an Al—Ti (5%)-B (1%) alloy wire 23 as a crystal refining material. By changing the supply rate, the Ti concentration {Ti} in the molten metal 22 can be changed. Alternatively, it is also possible to add a required amount of a master alloy block of Al—Ti (5%) or Al—Ti (5%) — B (1%) into the melting and holding furnace 12. . If the Ti content is zero, crystal refinement cannot be performed, and it is economically undesirable that the Ti content is too large. The amount of Ti is desirably 0.005 to 0.04%. In this example and the comparative example, the Ti amount was set to 0.02%.
[0010]
The continuously cast sheet is then rolled between rolling rolls 56 of a cold rolling mill 50 to a predetermined thickness. Further, it is heat-treated by the continuous annealing device 60 or the batch annealing device 70, and is again rolled between the rolling rollers 56 of the cold rolling mill 50 to a predetermined thickness of 0.1 mm to 0.5 mm. In this example, both the example and the comparative example were thinned by cold rolling to a sheet thickness of 2 mm, heat-treated at 550 ° C. × 10 hours using a batch annealing apparatus, and then again thickened by a cold rolling mill. Finished to 0.24 mm. The flatness may be improved by the straightening roller 86 of the straightening machine 80, and the ear may be cut to a predetermined width by the slitter 88 as needed. Thus, an Al plate for a lithographic printing plate is manufactured.
A lithographic printing plate can be obtained by subjecting the aluminum plate thus obtained to a roughening treatment, an anodic oxidation treatment, and application and drying of a photosensitive layer. Here, the method of the present invention and a comparative example were prepared using release materials having different particle size distributions and average particle sizes. An experiment was carried out to continuously cast 300 kg in both the comparative example and the present invention, and it was determined whether or not sticking occurred between the casting plate and the cooling roller. The appearance at the time of going was evaluated. The results are shown in Table 1.
[0011]
[Table 1]

[0012]
As shown in Table 1, in Examples of the present invention, no sticking occurs and the crystal structure of the cast plate can be made fine, so that a lithographic printing plate support having excellent appearance can be obtained.
Examples 4 to 7
Samples were prepared in the same manner as in Examples 1 to 3 and Comparative Examples 1 to 3 except that the coating amount of the release material was changed, and Examples and Comparative Examples of the present invention were evaluated. The results are shown in Table 2.
[0013]
[Table 2]

[0014]
As shown in Table 2, in Examples of the present invention, no sticking occurs and the crystal structure of the cast plate does not become coarse, so that a lithographic printing plate support having an excellent appearance can be obtained. On the other hand, in the comparative example, it was not possible to achieve both the prevention of sticking, the refinement of crystal grains, and the appearance when finished into a lithographic printing plate support.
[0015]
【The invention's effect】
In the present invention, a continuous cast plate having a thickness of 10 mm to 1 mm is cast using a twin-roller continuous casting apparatus, heat-treated in the middle, and finished to a thickness of 0.1 to 0.5 mm by cold rolling. When manufacturing an aluminum alloy support for a printing plate, the size and particle size distribution of the lubricating component particles contained in the release roller applied to the cooling roller should be within a certain range, and the amount of the release material applied on the cooling roller surface 60 to 1200 mg / m ² , the peelability can be improved without lowering the heat conduction between the cooling roller and the cast plate. In addition to eliminating defects, the crystal structure of the cast plate can be made uniform and fine. I can do it.
[Brief description of the drawings]
FIG. 1 shows an entire configuration of a continuous casting and rolling apparatus which is an example of an embodiment of the present invention.
FIG. 2 shows an overall configuration of a cold rolling apparatus as an example of an embodiment of the present invention.
FIG. 3 shows an entire configuration of a continuous annealing apparatus which is an example of a heat treatment process according to an embodiment of the present invention.
FIG. 4 shows an overall configuration of a batch annealing apparatus which is another example of the heat treatment process according to the embodiment of the present invention.
FIG. 5 shows an overall configuration of a straightening device as an example of an embodiment of the present invention.
FIG. 6 is a diagram showing an example of a desirable particle size distribution of a release material.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Continuous casting and rolling apparatus 12 Melting and holding furnace 14 Gutter 16 Melt supply nozzle 18 Rotary cooling roller 22 Melt 32 Liquid level sensor 36 Casting plate 37 Rolling plate 38 Cutter 46 Release material coating device 50 Cold rolling mill 56 Rolling roller 58 Backup roller 80 straightening device 86 straightening roller

Claims

An aluminum alloy melt is supplied through a molten metal supply nozzle between a pair of cooling rollers, on which a suspension containing fine particles is continuously or intermittently applied as a release material on the roller surface, and the cooling rollers provide: Rolling while solidifying the aluminum melt, continuous casting of an aluminum casting plate having a thickness of 10 mm to 1 mm using a twin-roller continuous casting device, finishing by cold rolling to a thickness of 0.1 to 0.5 mm, In a method of manufacturing an aluminum alloy support for a lithographic printing plate,
Fine particles contained in the release material,
Average particle size = 0.7 to 1.5 μm,
Median diameter = 0.5 to 1.2 μm,
Particles less than 0.2 μm account for less than 5% of the total particles,
Less than 10% of particles having a size of 0.4 μm or less.
Less than 10% of particles of 2 μm or more;
A method for producing an aluminum alloy support plate for a lithographic printing plate, wherein particles of 3 μm or more are less than 5%, and the amount of the release material applied on a cooling roller is 60 to 1200 mg / m ² .

The method for producing an aluminum alloy support plate for a lithographic printing plate according to claim 1, wherein the aluminum alloy is a JIS1000-based or JIS3000-based material.

Aluminum alloy: Fe: 0.03 to 0.8%, Si: 0.02 to 0.3%, Cu: 0 to 0.05%, Ti: 0.005 to 0.1%, Mg: 0 to 0 The method for producing an aluminum alloy support plate for a lithographic printing plate according to claim 1, comprising 0.05% by weight.

2. The method for producing an aluminum alloy support plate for a lithographic printing plate according to claim 1, wherein the release material has a composition mainly composed of carbon graphite.

The method for producing an aluminum alloy support plate for a lithographic printing plate according to claim 1, wherein the release material has a composition containing molybdenum sulfide as a main component.