JP3739478B2

JP3739478B2 - Antireflection multilayer film, film forming method and film forming apparatus

Info

Publication number: JP3739478B2
Application number: JP06860896A
Authority: JP
Inventors: 健桃野; 昌弘松本; 裕明川村; 賀文太田; 久三中村
Original assignee: Ulvac Inc
Current assignee: Ulvac Inc
Priority date: 1996-03-25
Filing date: 1996-03-25
Publication date: 2006-01-25
Anticipated expiration: 2016-03-25
Also published as: JPH09258004A

Description

【０００１】
【発明の属する技術分野】
本発明は、眼鏡レンズ等の光学機器や各種部品に適用される反射防止多層膜、およびその成膜方法並びにその成膜装置に関する。
【０００２】
【従来の技術】
従来、眼鏡レンズの両面或いは片面に低屈折率と高屈折率の誘電体材料を交互に成膜し、レンズの内側では反射による視認性の低下を防止すると共にその外側では光の反射を防止することが行われている。また、最近では、ＶＤＴ作業における外光の映り込み防止のために、表面に直接反射防止膜を成膜したディスプレーや、ＰＥＴ（ポリエチレンテレフタレート）やＰＭＭＡ（ポリメチルメタアクリレート）等のフィルム状の高分子基板上に反射防止膜を成膜してこれをディスプレー上に貼着け或いは前面に設置したものが市販されている。
【０００３】
これらの反射防止膜は、その機能的性格上、常に外界の生活環境、例えば眼鏡レンズでは雨水、汗、唾、ディスプレーではコーヒー、紅茶、酒等のしぶき、幼児の指紋やよだれ、等に晒されるため、光学膜としての反射防止性能が劣化する。通常の汚染の場合、水や洗剤等を含んだ布巾や雑巾などで比較的手荒く洗浄されるのが一般である。
【０００４】
しかし、光学膜を構成する誘電体膜は、表面エネルギーが大きいため、体液に含まれる油分や飲料等に含まれるＣａ、Ｍｇ、Ｎａ等のいわゆるミネラル成分が一旦付着すると、洗剤等で拭いても１００Å以上の残査が残る。そればかりでなく、拭きムラが発生し、著しく光学特性が劣化し、反射防止性能が失われる場合もあり、反射防止膜には水分をはじく特性、つまり撥水性が要求される。
【０００５】
そこで従来の反射防止膜では、光学膜を構成する誘電体層の上に、Ｃ、Ｆ、Ｈ、Ｎ、Ｓ、Ｏ、Ｓｉ等から成る高分子材料、いわゆる界面活性剤が２０〜３０Åの膜厚で形成される。
【０００６】
反射防止膜は通常、多層膜で構成され、その最上層の誘電体膜であるＳｉＯ_XやＡｌＯ_X、ＭｇＦ_X等の水接触角は、通常、ＳｉＯ_Xで約１０°、ＡｌＯ_X、ＭｇＦ_Xで６０°程度であり、撥水性が不充分であるが、前記の界面活性剤が形成されたものは１１０°の水接触角を示し、実用上の撥水性は充分に満たされている。図１の（ａ）にＴｉＯ_XとＳｉＯ_X膜を有する従来の反射防止膜、図１の（ｂ）にＩＴＯとＳｉＯ_X膜を有する従来の反射防止膜の構造を示した。
【０００７】
反射防止膜は可視光透過性の光学フィルターであるから、基板には、通常、透光性を有する透明なＰＥＴ、ＰＭＭＡやガラス等が用いられる。図１の模式図（ａ）は、高屈折率の誘電体膜ＴｉＯ_Xと、低屈折率のＳｉＯ_X膜を交互に設計値に見合った膜厚で４層積層したもので、図１の模式図（ｂ）は、基板上の第１層目と第３層目が導電性のＩＴＯ膜になっており、導電性を持たせることによって反射防止膜に電磁シールド機能を保有させたものである。いかなる場合でも、反射防止特性を発現させるために最上層は屈折率の低いＳｉＯ_X、ＡｌＯ_X、ＭｇＦ_X、或いはこれらの混合物、例えば、Ａｌ−Ｓｉ−Ｏ_X等の材料が選択される。これら従来の反射防止膜の最上層の膜の上に、反射防止特性を阻害しない範囲の膜厚３０Å以下の界面活性剤の撥水層が形成されている。
【０００８】
図２は従来の反射防止膜の成膜装置の１例の説明図であり、反射防止膜を構成する光学膜の成膜用の真空槽ａと撥水層の成膜用の真空槽ｂとを分離独立して設け、まず真空槽ａ内に於いて繰り出しロールｄに取り付けた例えばＰＥＴ等のロール状の高分子フィルム基板ｃを成膜ドラムｅを循環して巻き取りロールｆへと繰り出し、該ドラムｅの周囲に配置した４基のスパッタ装置ｇにＲＦ電源から電力を投入して該装置ｇのスパッタターゲットをスパッタし、交互にＴｉＯ₂とＳｉＯ₂の薄膜を循環移動する該基板ｃに成膜して巻き取る。膜厚はＲＦ電力の投入量で調整される。そして巻き取った該基板ｃを１０^-5Torr程度の真空に保った真空槽ｂ内の繰り出しロールｈに取り付け、これより成膜ドラムｉを循環して巻き取りロールｊの巻き取られる間にＤＣ電源に接続したタングステンボートの蒸発源ｋから溶融蒸発するベヘン酸等の界面活性剤を例えば約３０Åの膜厚で蒸着して撥水層を形成することにより反射防止多層膜が成膜される。撥水層の厚さはＤＣ電源のパワーを調整することにより、所望値に調整できる。ｌ、ｍは真空ポンプに接続された真空排気孔、ｎはアルゴンガスの導入口で、真空槽ａ内は１０^-2〜１０^-4Torr程度にガス導入量と排気量とで調整される。尚、光学膜の成膜に蒸着法を使用し、撥水層をＣＶＤ、スクリーン印刷、ディピング等により形成することも行われている。
【０００９】
【発明が解決しようとする課題】
図１に代表的に示した従来の反射防止膜は、光学膜である積層誘電体膜の上に直接に撥水層である界面活性剤が成膜されている。通常、光学膜の光学的特性つまり反射防止特性を阻害しない撥水層の膜厚は３０Å以下であるから、界面活性剤の単分子層程度に成膜厚さが制限される。そのため、界面活性剤には、カルボキシル基等の電気的分極によって光学膜である誘電体材料と弱い電気的結合をする材料が選択されている。しかし、化学的反応を伴わない結合であるため、機械的摩擦によって膜剥離を発生する欠点がある。
【００１０】
図２の装置で作成した反射防止膜は、脱脂綿に１００％エタノールを含ませ、２５０ｇ／ｃｍ²の荷重と２ｃｍ／ｓｅｃの速さで１０回ランビングすると、０．５ｃｃ初期水接触角１１０°が８０°に低下し、実用性を満足していない。またその装置は、光学膜成膜用と撥水層成膜用が独立分離しているので、生産性の観点からコスト高となっており、基板は真空槽内で光学膜を成膜したのちこれより一旦大気中に取り出し、撥水層成膜用の真空槽に収めて成膜されるので、大気中のＨ₂Ｏ、Ｏ₂、Ｎ₂等が付着し、撥水層の耐久性が向上しない。具体的には、図２の装置の真空槽ａで表１、表２の諸元で作成した光学膜を５０℃、湿度５５％の大気中に放置し、その放置時間を変えて真空槽ｂに入れ、表２の諸元で撥水層を成膜した後、０．５ｃｃ、水接触角を測定した結果は図３に示す如くである。これに黒丸で示した水接触角は、脱脂綿に１００％エタノールを含ませ、２５０ｇ／ｃｍ²の荷重と２ｃｍ／ｓｅｃの速さで１０回ランビングしたのちの測定値であり、白丸はラビリング前の水接触角である。これより大気中の放置時間が長くなるに従ってラビリング後の水接触角の低下が見られる。
【００１１】
【表１】

【００１２】
【表２】

【００１３】
本発明は、容易に剥離しない耐久性及び撥水性の良い撥水層を備えた反射防止膜を提供すること、およびこの反射防止膜を成膜する方法、並びにこの反射防止膜を安価に作製できる装置を提供することを目的とするものである。
【００１４】
【課題を解決するための手段】
本発明では、基板上に、屈折率の異なった２種以上の材料で２層以上の反射防止用の光学薄膜を成膜し、該光学薄膜上にＣ、Ｆ、Ｈ、Ｎ、Ｓ、Ｏ、Ｓｉ等から構成される高分子材料の薄膜を撥水層として成膜した反射防止多層膜に於いて、該光学薄膜と撥水層の間に１０Å以下の膜厚でＡｌ、Ｔｉ、Ｓｉ、Ｎｂ、Ｃｒ、Ｃｕ、Ｍｇ、Ｔａ、Ｚｒのいずれかから構成される中間層を設けることにより、上記目的を達成するようにした。該中間層は該光学薄膜の最上層の薄膜及び該撥水層と化学反応で互いに結合する材料から成り、該中間層を該光学薄膜上に蒸着又はスパッタにより形成し、その上に撥水層を蒸着又はスパッタにより形成することが好ましく、請求項４の方法とすることにより、容易に剥離せずしかも撥水性のよい反射防止多層膜が安価に製作でき、この方法は請求項５の装置構成により的確に実施できる。
【００１５】
【発明の実施の形態】
本発明の実施の形態を図４に示す反射防止多層膜の模式図に基づき説明すると、同図に於いて符号１はガラス、プラスチックス等の着色又は無色の透明なセラミックス基板や高分子フィルム基板から成る任意の厚さの基板、２は該基板１上に設けられた反射防止多層膜を示し、該膜２は該基板１上に成膜された屈折率の異なった２種以上の材料から成り２層以上に形成された反射防止用の光学薄膜３と該光学薄膜３を保護するベヘン酸から成る撥水層４を有する。該撥水層４は、通常は約３０Å以下である。
【００１６】
こうした膜構成は従来のものも備えるところであるが、本発明では該光学薄膜３と撥水層４の間に１０Å以下の膜厚でＡｌ、Ｔｉ、Ｓｉ、Ｎｂ、Ｃｒ、Ｃｕ、Ｍｇ、Ｔａ、Ｚｒのいずれかから構成されて該光学薄膜の最上層の薄膜及び撥水層４の材料と化学反応する中間層５を設け、従来の撥水層が剥離し易く撥水性が失われ易い欠点を解消するようにした。該基板１にはガラス、ＰＥＴ、ＰＭＭＡが多用される。該光学薄膜３としてはＴｉＯ_X、ＳｉＯ_X、ＡｌＯ_X、ＭｇＦ_X、ＴａＯ_X、ＭｇＯ、ＺｒＯ_X、ＩＴＯ等の公知の材料が使用され、スパッタリング若しくは蒸着により膜設計値に応じた膜厚で２層以上例えば４層３ａ、３ｂ、３ｃ、３ｄに形成される。該中間層５もスパッタリング又は蒸着で反射防止機能を損なわないように極めて薄く形成され、化学反応により該光学薄膜３に強固に付着ししかも撥水層４とも化学反応して結合するから撥水層４は容易に該光学薄膜３から剥離しない。
【００１７】
該反射防止多層膜２を高分子フィルムの基板１に形成する製造装置の１例は図５に示す如くであり、１つの真空槽６内に２つの成膜ドラム７、８を回転自在に設け、該成膜ドラム７、８の周囲の空間を区画壁９、１０、１１で３つに区画し、その１の空間１２に両成膜ドラム７、８の周面の一部を露出させると共に該基板１の繰り出しロール１３と巻き取りロール１４を配置し、残りの一つの空間１５に反射防止用の光学薄膜３を２層以上に形成するために２基以上のスパッタ装置１６ａ、１６ｂ、１６ｃ、１６ｄを設け、残りのもう一つの空間１７に撥水層４を形成するための蒸発源１８が設けられ、該１の空間１２に、光学薄膜３の成膜を終えた該基板１上に中間層５を成膜するためのスパッタ装置１９を設けた構成を有する。光学薄膜３と撥水層４を成膜する各空間１５、１７には、夫々真空ポンプに接続された排気口２０、２１が設けられ、各空間１５、１７をスパッタ或いは蒸着に適した真空圧に排気する。２２はアルゴン等のスパッタガスを導入するガス導入口である。
【００１８】
ロール状の高分子フィルムの基板１を繰り出しロール１３にセットし、各空間１２、１５、１７を成膜に適した真空圧になるように排気口２０、２１から排気する。そして該繰り出しロール１３及び巻き取りロール１４を駆動し、各スパッタ装置１６ａ〜１６ｄ、１９にＲＦ電力、及び蒸発源１８にＤＣ電力を投入すると、移動する基板１の表面に４層の光学薄膜３が形成され、続いて中間層５が形成され、更にその上に例えば２０Åの撥水層４が形成されて反射防止多層膜２が製造される。該基板１の速度とスパッタ装置１９の電力を調整することにより、光学薄膜３の反射防止機能を損なわない程度の１０Å以下の薄い中間層５を成膜出来、また、各空間１２、１５、１７は区画壁９、１０、１１でコンダクタンスが小さくなるように区画されていため、空間１５、１７をプロセスに見合ったガス圧力に保てる。
【００１９】
空間１５のスパッタ装置１６ａ、１６ｃのターゲットをＴｉＯ_X、残りのスパッタ装置１６ｂ、１６ｄのターゲットをＳｉＯ_Xとし、空間１２のスパッタ装置１９のターゲットをＴｉ、蒸発源１８にベヘン酸の蒸発材料を入れ、該空間１５を例えば１０^-2乃至１０^-4Torr、空間１７を１０^-5Torrとすれば、ＴｉＯ_XとＳｉＯ_Xが交互に４層に積層された光学薄膜３とベヘン酸の撥水層４との間にＴｉの中間層５を持つ図４に示した膜構造の反射防止多層膜２が得られる。
【００２０】
こうして製造された反射防止多層膜２は、真空雰囲気中で順次に成膜されたため、撥水性を劣化させるＨ₂Ｏ、Ｏ₂、Ｎ₂などの不純物が膜中に混入することがなく、Ｔｉの中間層５が最上層の光学薄膜３ｄとＴｉ−ＳｉやＴｉ−Ｏの化学的結合すると同時に撥水層４とも化学的結合して脂肪酸塩を生成するため通常のテープ剥離試験即ち１００％エタノールを含ませた脱脂綿で２５０ｇ／ｃｍ²の荷重をかけ２ｃｍ／ｓｅｃの速度で１０回ランビングしても剥離することのない強固な結合となり、図６に示すように、従来のものの水接触角１１０°よりも大きくなり、撥水性が大きくしかもランビングされても撥水機能の低下が小さく、その生産性が向上して安価に製作できる。
【００２１】
該撥水層４のランビング後の水接触角は、図６に示したように、中間層５の膜圧が増加するに従って増加するが、その厚さが１０Å以上では一定になり、０Å付近でも従来のものと異なり１１０°を保持することができる。
【００２２】
最上層の光学薄膜３ｄがＳｉＯ_X以外の例えばＴｉＯ_X、ＡｌＯ_Xであっても、中間層５にＴｉ以外のＡｌ、Ｓｉ、Ｎｂ、Ｃｒ、Ｃｕ、Ｍｇ、Ｔａ、Ｚｒ或いはこれらの合金組成物を使用しても従来よりも剥離しにくく撥水性のよい反射防止多層膜が得られる。また、光学薄膜３を蒸着によって成膜してもスパッタ成膜した場合と同様の効果がある。撥水層４にポリテトラフルオロエチレン（商品名テフロン）をスパッタで或いはイオンビームスパッタで成膜した場合も同様の効果があった。尚、上記高分子フィルム基板の代わりに建材用のガラスの基板１を使用してもよい。
【００２３】
【実施例】
厚さ２５０ミクロン、幅１ｍ、長さ５００ｍのロール状に巻いたＰＥＴフィルムの基板１に、図５に示す装置を使用して４層の光学薄膜３の上にＴｉの中間層５を介してベヘン酸の撥水層４を有する反射防止多層膜２を成膜した。該光学薄膜３はＴｉＯ_XとＳｉＯ_Xの交互の４層とし、該光学薄膜３及び中間層５は５基のＲＦマグネトロンスパッタ装置により形成し、撥水層４はＤＣ抵抗加熱の蒸着装置により蒸着した。中間層５はカソードパワーを変えて０、５、１０、１５、２０Åの５種類の膜厚で作製し、撥水層４は１０Åとした。フィルム基板の巻き取り速度は０．３ｍ／ｍｉｎ、その他の諸元は表３に示した。
【００２４】
【表３】

【００２５】
これにより得られた反射防止多層膜２の模式的構造は図４と同様であり、各膜の中間層の厚さと水接触角の関係は図６の白丸、黒丸で示す如くであった。白丸はラビリング前の初期接触角、黒丸はラビリング後の接触角である。尚、同図の白三角及び黒三角は従来の図２の装置により作製した図１の（ａ）の膜構造を有する反射防止多層膜のラビリング前とラビリング後の水接触角である。これより明らかなように、本発明の方法で作製した反射防止多層膜２の水接触角は１２５°と大きく、ラビリング後でも１１０°以上の充分な水接触角を有し、耐久性の良い撥水性を持つことが分かる。また、このラビリングは、１００％エタノールを含ませた脱脂綿で荷重２５０ｇ／ｃｍ²、２ｃｍ／ｓｅｃの速度で１０回行ったが、撥水層４の剥離はなかった。本発明では反射防止多層膜２の完成まで基板１が大気中に曝されないので、従来よりも生産時間が短い。
【００２６】
【発明の効果】
以上のように本発明によるときは、高分子フィルム基板等の基板上に形成した屈折率の異なった２種以上の材料で２層以上から成る反射防止用の光学薄膜とＣ、Ｆ、Ｈ、Ｎ、Ｓ、Ｏ、Ｓｉ等の高分子材料の撥水層の間に１０Å以下の膜厚でＡｌ、Ｔｉ、Ｓｉ、Ｎｂ、Ｃｒ、Ｃｕ、Ｍｇ、Ｔａ、Ｚｒのいずれかから構成される中間層を設けたので、撥水層が剥離しにくく撥水性も向上する効果が得られ、請求項４の方法で本発明の反射防止多層膜を製作することにより撥水層が剥離しにくい反射防止多層膜を能率良く生産できる効果があり、請求項５の装置構成とすることにより本発明の方法を的確に実施できる効果がある。
【図面の簡単な説明】
【図１】従来の反射防止多層膜の模式的構造図
【図２】従来の反射防止多層膜の製造装置の説明図
【図３】従来の反射防止多層膜の光学薄膜を大気中に放置した時間と水接触角との関係図
【図４】本発明の反射防止多層膜の模式的構造図
【図５】本発明の反射防止多層膜の製造装置の説明図
【図６】本発明の反射防止多層膜の中間層の厚さと水接触角の関係図
【符号の説明】
１基板、２反射防止多層膜、３、３ａ、３ｂ、３ｃ、３ｄ光学薄膜、４撥水層、５中間層、６真空槽、７、８成膜ドラム、９、１０、１１区画壁、１２、１５、１７空間、１６ａ、１６ｂ、１６ｃ、１６ｄ、１９スパッタ装置、１８蒸発源、[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an antireflection multilayer film applied to optical devices such as spectacle lenses and various parts, a film forming method thereof, and a film forming apparatus thereof.
[0002]
[Prior art]
Conventionally, a dielectric material having a low refractive index and a high refractive index is alternately formed on both sides or one side of a spectacle lens to prevent deterioration of visibility due to reflection inside the lens and to prevent light reflection outside the lens. Things have been done. Also, recently, in order to prevent reflection of external light in VDT work, a display with an antireflection film formed directly on the surface, or a film-like high film such as PET (polyethylene terephthalate) or PMMA (polymethyl methacrylate) An antireflection film is formed on a molecular substrate and the film is affixed on a display or installed on the front surface.
[0003]
Due to their functional characteristics, these anti-reflective coatings are always exposed to the outside living environment, such as rainwater, sweat, saliva for spectacle lenses, splash of coffee, tea, liquor, etc. for display, fingerprints and drooling of infants, etc. Therefore, the antireflection performance as an optical film is deteriorated. In the case of normal contamination, it is generally washed relatively rough with a cloth or rag containing water or detergent.
[0004]
However, since the dielectric film constituting the optical film has a large surface energy, once a so-called mineral component such as Ca, Mg, Na contained in body fluids or beverages is adhered, it can be wiped with a detergent or the like. There remains a residue of over 100cm. Not only that, wiping unevenness occurs, optical characteristics deteriorate significantly, and the antireflection performance may be lost. The antireflection film is required to have a water repellent characteristic, that is, water repellency.
[0005]
Therefore, in the conventional antireflection film, a polymer material made of C, F, H, N, S, O, Si, or the like, that is, a so-called surfactant is 20 to 30 mm on the dielectric layer constituting the optical film. Formed with thickness.
[0006]
The antireflection film is usually composed of a multilayer film, and the water contact angle of SiO _x , AlO _x , MgF _x, etc., which is the uppermost dielectric film, is usually about 10 ° for SiO _x , AlO _x , MgF _x. However, the water repellency is insufficient, but the one formed with the surfactant exhibits a water contact angle of 110 °, and the practical water repellency is sufficiently satisfied. FIG. 1 (a) shows the structure of a conventional antireflection film having a TiO _x and SiO _x film, and FIG. 1 (b) shows the structure of a conventional antireflection film having an ITO and SiO _x film.
[0007]
Since the antireflection film is a visible light transmissive optical filter, transparent PET, PMMA, glass, or the like having translucency is usually used for the substrate. The schematic diagram (a) of FIG. 1 is obtained by laminating four layers of dielectric films TiO _x having a high refractive index and SiO _x films having a low refractive index alternately with a thickness corresponding to the design value. In FIG. 2B, the first layer and the third layer on the substrate are made of conductive ITO films, and the antireflection film has an electromagnetic shielding function by providing conductivity. . In any case, in order to develop antireflection characteristics, the top layer is made of a material such as SiO _x , AlO _x , MgF _x , or a mixture thereof such as Al—Si—O _x having a low refractive index. On the uppermost film of these conventional antireflection films, a water repellent layer of a surfactant having a thickness of 30 mm or less in a range not inhibiting the antireflection characteristics is formed.
[0008]
FIG. 2 is an explanatory view of an example of a conventional antireflection film forming apparatus, in which a vacuum chamber a for forming an optical film constituting the antireflection film and a vacuum chamber b for forming a water repellent layer are provided. In a vacuum chamber a, a roll-shaped polymer film substrate c such as PET attached to a feed roll d is circulated through a film formation drum e and fed to a take-up roll f. Power is supplied from an RF power source to four sputtering devices g arranged around the drum e to sputter the sputtering target of the device g, and the TiO ₂ and SiO ₂ thin films are alternately circulated and moved to the substrate c. Film and wind up. The film thickness is adjusted by the input amount of RF power. Then, the wound substrate c is attached to a feeding roll h in a vacuum chamber b maintained at a vacuum of about 10 ⁻⁵ Torr. An antireflection multilayer film is formed by depositing a surfactant such as behenic acid, which is melted and evaporated from an evaporation source k of a tungsten boat connected to a power source, with a film thickness of, for example, about 30 mm to form a water repellent layer. The thickness of the water repellent layer can be adjusted to a desired value by adjusting the power of the DC power source. l and m are evacuation holes connected to a vacuum pump, n is an argon gas introduction port, and the inside of the vacuum chamber a is adjusted to about 10 ⁻² to 10 ⁻⁴ Torr by the gas introduction amount and the evacuation amount. In addition, an evaporation method is used for forming an optical film, and a water repellent layer is formed by CVD, screen printing, dipping, or the like.
[0009]
[Problems to be solved by the invention]
In the conventional antireflection film typically shown in FIG. 1, a surfactant as a water repellent layer is formed directly on a laminated dielectric film as an optical film. Usually, the film thickness of the water-repellent layer that does not impair the optical characteristics of the optical film, that is, the antireflection characteristics, is 30 mm or less, and thus the film thickness is limited to about a monomolecular layer of the surfactant. For this reason, a material that weakly bonds to the dielectric material, which is an optical film, by electrical polarization such as a carboxyl group is selected as the surfactant. However, since it is a bond that does not involve a chemical reaction, there is a drawback in that film peeling occurs due to mechanical friction.
[0010]
The anti-reflective coating prepared with the apparatus of FIG. 2 contains 100% ethanol in absorbent cotton and is rubbed 10 times with a load of 250 g / cm ² and a speed of 2 cm / sec. It drops to 80 ° and does not satisfy practicality. In addition, since the apparatus for forming an optical film and the film for forming a water repellent layer are separately separated, the cost is high from the viewpoint of productivity, and the substrate is formed after forming the optical film in a vacuum chamber. Since it is once taken out into the atmosphere and stored in a vacuum chamber for forming a water-repellent layer, the film is deposited, so that H ₂ O, O ₂ , N _2, etc. in the atmosphere adhere to it and the durability of the water-repellent layer is increased. Does not improve. Specifically, the optical film prepared according to the specifications shown in Tables 1 and 2 in the vacuum chamber a of the apparatus shown in FIG. 2 is left in the atmosphere of 50 ° C. and 55% humidity, and the storage time is changed. Then, after forming a water-repellent layer according to the specifications shown in Table 2, the result of measuring the water contact angle of 0.5 cc is as shown in FIG. The water contact angle indicated by black circles is a measured value after 10% ramming with 100% ethanol in absorbent cotton and a load of 250 g / cm ² and a speed of 2 cm / sec. Water contact angle. From this, as the standing time in the atmosphere becomes longer, the water contact angle after the labyrinth is decreased.
[0011]
[Table 1]

[0012]
[Table 2]

[0013]
The present invention provides an antireflection film provided with a water repellent layer having good durability and water repellency that does not easily peel off, a method of forming the antireflection film, and the antireflection film can be produced at low cost. The object is to provide an apparatus.
[0014]
[Means for Solving the Problems]
In the present invention, two or more antireflection optical thin films are formed on a substrate with two or more materials having different refractive indexes, and C, F, H, N, S, and O are formed on the optical thin film. In the antireflection multilayer film in which a thin film of a polymer material composed of Si or the like is formed as a water repellent layer, Al, Ti, Si, By providing an intermediate layer composed of any one of Nb, Cr, Cu, Mg, Ta, and Zr, the above object is achieved. The intermediate layer is made of a material that is bonded to the uppermost thin film of the optical thin film and the water repellent layer by a chemical reaction, the intermediate layer is formed on the optical thin film by vapor deposition or sputtering, and the water repellent layer is formed thereon. preferably formed by vapor deposition or sputtering, by a method according to claim 4, easily without addition inexpensive to manufacture good antireflection multilayer film having water repellency peeling, the method device structure of claim 5 Can be implemented more accurately.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
The embodiment of the present invention will be described with reference to the schematic diagram of the antireflection multilayer film shown in FIG. 4. In the figure, reference numeral 1 denotes a transparent or colorless ceramic substrate or polymer film substrate such as glass or plastics. A substrate 2 having an arbitrary thickness, 2 is an antireflection multilayer film provided on the substrate 1, and the film 2 is made of two or more kinds of materials having different refractive indexes formed on the substrate 1. It has an antireflection optical thin film 3 formed in two or more layers and a water repellent layer 4 made of behenic acid for protecting the optical thin film 3. The water repellent layer 4 is usually about 30 mm or less.
[0016]
Although such a film configuration is also provided in the prior art, in the present invention, Al, Ti, Si, Nb, Cr, Cu, Mg, Ta, with a film thickness of 10 mm or less between the optical thin film 3 and the water repellent layer 4. An intermediate layer 5 made of any of Zr and chemically reacting with the uppermost thin film of the optical thin film and the material of the water repellent layer 4 is provided, and the conventional water repellent layer is easily peeled off and the water repellency is easily lost. It was made to cancel. Glass, PET, and PMMA are frequently used for the substrate 1. As the optical thin film 3, a known material such as TiO _x , SiO _x , AlO _x , MgF _x , TaO _x , MgO, ZrO _x , and ITO is used, and the film thickness is 2 according to the film design value by sputtering or vapor deposition. For example, four

layers

3a, 3b, 3c, and 3d are formed. Since the intermediate layer 5 is also formed extremely thin so as not to impair the antireflection function by sputtering or vapor deposition, it adheres firmly to the optical thin film 3 by a chemical reaction, and bonds with the water repellent layer 4 through a chemical reaction. 4 does not easily peel off from the optical thin film 3.
[0017]
An example of a manufacturing apparatus for forming the antireflection multilayer film 2 on the polymer film substrate 1 is as shown in FIG. 5, and two film-forming drums 7 and 8 are rotatably provided in one vacuum chamber 6. The space around the film forming drums 7 and 8 is divided into three by

partition walls

9, 10 and 11, and a part of the peripheral surface of both film forming drums 7 and 8 is exposed to the one space 12. The feeding roll 13 and the winding roll 14 of the substrate 1 are arranged, and two or

more sputtering apparatuses

16a, 16b, 16c are formed in order to form two or more antireflection optical thin films 3 in the remaining one space 15. 16d, and an evaporation source 18 for forming the water repellent layer 4 is provided in the remaining one space 17. On the substrate 1 on which the optical thin film 3 has been formed, the first space 12 is formed. A sputtering apparatus 19 for forming the intermediate layer 5 is provided. The

spaces

15 and 17 where the optical thin film 3 and the water repellent layer 4 are formed are respectively provided with

exhaust ports

20 and 21 connected to a vacuum pump, and the

spaces

15 and 17 are provided with a vacuum pressure suitable for sputtering or vapor deposition. Exhaust. Reference numeral 22 denotes a gas inlet for introducing a sputtering gas such as argon.
[0018]
The roll-shaped polymer film substrate 1 is set on the feeding roll 13, and the

spaces

12, 15, and 17 are exhausted from the

exhaust ports

20 and 21 so as to have a vacuum pressure suitable for film formation. Then, when the feeding roll 13 and the take-up roll 14 are driven and RF power is supplied to each of the sputtering devices 16a to 16d and 19 and DC power is supplied to the evaporation source 18, four optical thin films 3 are formed on the surface of the moving substrate 1. Then, the intermediate layer 5 is formed, and the water-repellent layer 4 having a thickness of, for example, 20 mm is formed thereon to manufacture the antireflection multilayer film 2. By adjusting the speed of the substrate 1 and the power of the sputtering apparatus 19, a thin intermediate layer 5 of 10 mm or less that does not impair the antireflection function of the optical thin film 3 can be formed, and each

space

12, 15, 17 can be formed. Is partitioned by the

partition walls

9, 10, and 11 so as to reduce the conductance, so that the

spaces

15 and 17 can be maintained at a gas pressure suitable for the process.
[0019]
The target of the sputter devices 16a and 16c in the space 15 is TiO _x , the target of the remaining

sputter devices

16b and 16d is SiO _x , the target of the sputter device 19 in the space 12 is Ti, and an evaporation material of behenic acid is put in the evaporation source 18. If the space 15 is, for example, 10 ^{−2 to} 10 ⁻⁴ Torr and the space 17 is 10 ⁻⁵ Torr, the optical thin film 3 in which TiO _x and SiO _x are alternately laminated in four layers and a water repellent layer of behenic acid Thus, the antireflection multilayer film 2 having the film structure shown in FIG.
[0020]
Since the antireflection multilayer film 2 manufactured in this way was sequentially formed in a vacuum atmosphere, impurities such as H ₂ O, O ₂ , and N ₂ that deteriorate water repellency are not mixed in the film, and Ti Since the intermediate layer 5 is chemically bonded to the uppermost optical thin film 3d and Ti—Si or Ti—O at the same time as the water repellent layer 4 to form a fatty acid salt, a normal tape peeling test, that is, 100% ethanol. Even if it is rubbed 10 times at a speed of 2 cm / sec with a load of 250 g / cm ² applied to the absorbent cotton containing water, it becomes a strong bond that does not peel off, and as shown in FIG. Even when rubbed, the water-repellent function is less deteriorated even when rubbed, and the productivity is improved and the product can be manufactured at a low cost.
[0021]
As shown in FIG. 6, the water contact angle after the water repellent layer 4 is increased as the film pressure of the intermediate layer 5 is increased. However, the thickness becomes constant when the thickness is 10 mm or more, and even near 0 mm. Unlike the conventional one, 110 ° can be held.
[0022]
Even if the uppermost optical thin film 3d is other than SiO _x , for example, TiO _x or AlO _x , the intermediate layer 5 is made of Al, Si, Nb, Cr, Cu, Mg, Ta, Zr or an alloy composition other than Ti. Even if it is used, it is possible to obtain an antireflection multilayer film which is less peeled than before and has good water repellency. Further, even when the optical thin film 3 is formed by vapor deposition, the same effect as in the case of forming the sputter film is obtained. The same effect was obtained when polytetrafluoroethylene (trade name: Teflon) was formed on the water repellent layer 4 by sputtering or ion beam sputtering. In addition, you may use the glass substrate 1 for building materials instead of the said polymer film board | substrate.
[0023]
【Example】
A PET film substrate 1 wound in a roll shape having a thickness of 250 microns, a width of 1 m, and a length of 500 m is formed on a four-layer optical thin film 3 via a Ti intermediate layer 5 using the apparatus shown in FIG. An antireflection multilayer film 2 having a water-repellent layer 4 of behenic acid was formed. The optical thin film 3 is composed of four alternating layers of TiO _x and SiO _x , the optical thin film 3 and the intermediate layer 5 are formed by five RF magnetron sputtering devices, and the water repellent layer 4 is deposited by a DC resistance heating vapor deposition device. did. The intermediate layer 5 was formed with five kinds of film thicknesses of 0, 5, 10, 15, and 20 mm while changing the cathode power, and the water repellent layer 4 was 10 mm. The film substrate winding speed was 0.3 m / min, and other specifications are shown in Table 3.
[0024]
[Table 3]

[0025]
The schematic structure of the antireflection multilayer film 2 obtained in this way was the same as in FIG. 4, and the relationship between the thickness of the intermediate layer of each film and the water contact angle was as shown by white circles and black circles in FIG. The white circle is the initial contact angle before rabbling, and the black circle is the contact angle after rabbling. The white triangles and black triangles in the figure are the water contact angles before and after the rabbling of the antireflection multilayer film having the film structure of FIG. 1A produced by the conventional apparatus of FIG. As is clear from this, the water contact angle of the antireflection multilayer film 2 produced by the method of the present invention is as large as 125 °, and has a sufficient water contact angle of 110 ° or more even after the rubbing, and has a good durability. You can see that it has water. Further, this labyrinth was performed 10 times with absorbent cotton containing 100% ethanol at a load of 250 g / cm ² and a speed of 2 cm / sec, but the water repellent layer 4 was not peeled off. In the present invention, since the substrate 1 is not exposed to the atmosphere until the antireflection multilayer film 2 is completed, the production time is shorter than the conventional one.
[0026]
【The invention's effect】
As described above, according to the present invention, an antireflection optical thin film composed of two or more layers of two or more materials having different refractive indexes formed on a substrate such as a polymer film substrate and C, F, H, An intermediate layer composed of any of Al, Ti, Si, Nb, Cr, Cu, Mg, Ta, and Zr with a film thickness of 10 mm or less between the water-repellent layers of polymer materials such as N, S, O, and Si Since the layer is provided, the water-repellent layer is hardly peeled off and the effect of improving the water repellency is obtained. By manufacturing the anti-reflective multilayer film of the present invention by the method of claim 4, the water-repellent layer is hardly peeled off. There is an effect that the multilayer film can be produced efficiently, and the apparatus configuration according to claim 5 has an effect that the method of the present invention can be carried out accurately.
[Brief description of the drawings]
FIG. 1 is a schematic structural view of a conventional antireflection multilayer film. FIG. 2 is an explanatory diagram of a conventional antireflection multilayer film manufacturing apparatus. FIG. 3 is a diagram showing an optical thin film of a conventional antireflection multilayer film left in the atmosphere. FIG. 4 is a schematic structural diagram of an antireflection multilayer film according to the present invention. FIG. 5 is an explanatory diagram of an apparatus for producing an antireflection multilayer film according to the present invention. Relationship between thickness of intermediate layer of prevention multilayer film and water contact angle 【Explanation of symbols】
DESCRIPTION OF SYMBOLS 1 Substrate, 2 Antireflection multilayer film, 3, 3a, 3b, 3c, 3d Optical thin film, 4 Water repellent layer, 5 Intermediate layer, 6 Vacuum chamber, 7, 8 Film formation drum, 9, 10, 11 Partition wall, 12 , 15, 17 space, 16a, 16b, 16c, 16d, 19 sputtering device, 18 evaporation source,

Claims

Two or more layers of an antireflection optical thin film are formed on a substrate with two or more materials having different refractive indexes, and C, F, H, N, S, O, Si, etc. are formed on the optical thin film. In an antireflection multilayer film formed by forming a thin film of a polymer material as a water repellent layer, Al, Ti, Si, Nb, Cr, and a film having a thickness of 10 mm or less between the optical thin film and the water repellent layer An antireflection multilayer film provided with an intermediate layer composed of any one of Cu, Mg, Ta, and Zr.

The intermediate layer is made of a material that is bonded to the uppermost thin film of the optical thin film and the water repellent layer by a chemical reaction. The intermediate layer is formed on the optical thin film by sputtering or vapor deposition, and the water repellent layer is formed thereon. The antireflection multilayer film according to claim 1, wherein the film is formed by sputtering or vapor deposition.

2. The antireflection multilayer film according to claim 1, wherein the substrate, the optical thin film, the water repellent layer, and the intermediate layer are transparent, and the substrate is made of glass, polyethylene terephthalate, or polymethyl methacrylate.

An anti-reflection optical thin film made of two or more materials having different refractive indexes on the substrate, an intermediate layer made of any of Al, Ti, Si, Nb, Cr, Cu, Mg, Ta, and Zr, and C Formation of an antireflection multilayer film characterized by sequentially forming a water-repellent layer of a polymer thin film composed of F, H, N, S, O, Si, etc. by sputtering or vapor deposition in a vacuum atmosphere Method.

Two film forming drums are rotatably provided in one vacuum chamber, and the space around the film forming drum is divided into three parts, and a part of the peripheral surfaces of both film forming drums is exposed in the one space. In addition, a polymer film substrate feed roll and a take-up roll are arranged, and a plurality of evaporations for forming two or more antireflection optical thin films with two or more materials having different refractive indexes in the remaining space A space provided with a source or a sputtering device and a space provided with an evaporation source or a sputtering device for forming a water-repellent layer are formed on the polymer film substrate on which the optical thin film has been formed in the one space. , Ti, Si, Nb, Cr, Cu, Mg, Ta, Zr An evaporation source or a sputtering apparatus for forming an intermediate layer is provided.