1333559 九、發明說明： 【發明所屬之技術領域】 本發明係有關於一種光學薄膜及其形成方法，且特別 有關於一種具有抗反射功能之光學薄膜及其形成方法。 【先前技術】 光學塑膠薄膜用基材本身的缺點是硬度低、不耐磨 B 耗，尤其光電產業之應用要求更高，因此其表面都需要高 精密、高性能的保護塗裝。台灣顯示器隨著五代廠、六代 廠不斷擴建，近幾年即將成為全球最大的LCD生產國，而 對於技術開發來說，為了提高耐用度以及使用時不受外界 光線干擾，LCD用光學薄膜的相關處理技術，如硬質塗膜 (hard coating)與抗眩、抗反射成了不可或缺的關鍵技術之 一一 〇 濺鍍用之硬質塗膜的性質要求上又比一般硬質塗膜嚴 Φ 格，例如，在液晶顯示器用抗反射膜的製程中，需要先形 成一層硬質塗膜，然後於硬質塗膜上利用真空濺鍍以形成 抗反射膜，因此底下的硬質塗膜必須能在真空下避免釋氣 現象(outgassing)，而且在丨賤鑛後仍然保持高硬度。其中， 抗反射膜的形成面臨生產速度慢與鍍膜品質不佳等問題。 習知技術中，Shin-Etsu於美國專利US 5021091利用 UV樹脂、石夕烧及次微米無機填料（inorganic submicron filler) 開發硬質塗膜材料。伊藤光學於曰本專利早期公開號JP 05-98214、JP 10-168389利用矽烷、環氧樹脂配方開發硬 0954-A22125TWF(N2)；P54960007TW；claire 5 1333559 質塗膜材料。DSM則於美國專利us 6013749中利用UV 樹脂、石夕烧、聚石夕氧炫(silic〇ne)、與奈米尺寸的矽石填料 (silica filler)開發硬質塗膜材料。 本案申請人亦在中華民國專利申請案第94147659號 揭露一種硬質塗膜組成物及硬質塗膜，該硬質塗膜可作為 藏鍵用之硬質塗膜’可解決習知技術之釋氣、翹曲及靜電 等問題。 ^ 【發明内容】 本發明進一步提供一光學薄膜及其形成方法，本發明 實施例提供之光學薄膜具有抗反射及抗眩光功能。 本發明提供一種光學薄膜，包括：一基底；一疊層， 在δ亥基底上，该豐層係由至少一第一材料層及至少一第二 材料層交替堆疊，其中該第一材料層具有一第一折射率， 該第二材料層具有一第二折射率，該第一折射率不等於該 第二折射率；以及一硬質塗膜，在該基底與該疊層之間。 參 該硬質塗膜的組成物包括：（Α)含有多官能曱基丙烯酸酯 (polyfunctional methacrylate)之感光樹脂；（Β)反應型無機填 料’由（i)烧氧基石夕烧(alkoxysilane)與（ii)奈米無機粉體反應 而成；（C)添加劑；以及（D)光起始劑。 本發明又提供一種光學薄膜的形成方法，包括：提供 一基底；在該基底上形成一疊層，該疊層係由至少一第一 材料層及至少一第二材料層交替堆疊，其中該第一材料層 具有一第一折射率，該第二材料層具有一第二折射率，該 第一折射率不等於該第二折射率；以及在該基底與該疊層 0954-A22125TWF(N2)：P54960007TW；claire 6 1333559 之間形成一硬質塗膜。該硬質塗膜的組成物包括：（A)含有 多官能曱基丙烯酸酯（polyfunctional methacrylate)之感光 树月曰，（B)反應型無機填料’由⑴烧氧基石夕院（aik〇XySiiane丨 與（ii)奈米無機粉體反應而成；（C)添加劑；以及(D)光起始 劑。 【實施方式】 以下將以實施例詳細說明做為本發明之參考。在圖式 • 或描述中，相似或相同之部分係使用相同之圖號。在圖式 中，元件之形狀或是厚度可擴大，圖中未繪示或描述之元 件’可以具有各種熟習此技藝之人士所知的形式。此外， 當敘述一層係位於一基板或是另一層上時，此層可直接位 於基板或是另一層上，或是其間亦可以有中介層。 請參照第1圖，其係緣示本發明實施例之光學薄膜。 在一例子中，光學薄膜100可應用於液晶顯示器。首先， 提供基底10。較佳者，基底10為透明基底，基底10可包 • 括玻璃基底、塑膠基底或可撓曲基底。 接著，在基底10上形成硬質塗膜11，硬質塗膜11可 藉由硬質塗膜組成物經照光固化而形成。硬質塗膜組成物 包括（A)含有多官能曱基丙稀酸@旨（p〇iyfUnctional methacrylate)之感光樹脂。多官能曱基丙烯酸酯可為一單體 或寡聚物，且可單獨或混合兩者以上一併使用，其中較佳 者例如.1，4- 丁 一醇一曱基丙細酸酉旨（1，4-butanediol di(meth)acrylate) ' 1，6-己二醇二曱基丙稀酸酯 (l，6-hexanediol di(meth)acrylate)等。應注意的是，雖然本 0954-A22l25TWF(N2):P54960007TW；claire 7 1333559 發明之感光樹脂以紫外光破化樹脂（uv curable resin)較 佳’但也可為可見光、電子束、射線等其他光硬化樹脂 系統。 硬質塗膜組成物更包括(B)反應型無機填料’由⑴烷氧 基石夕炫(alkoxysilane)與（ii)奈米热機粉體反應而成。藉由無 機奈米粉體表面導入可參與反應的有機官能基’使無機奈 米粉體可均勻分散及與感光樹脂反應。反應型無機填料較 佳具有下列至少一種能與(A)感光樹脂反應之官能基：乙焊 基、丙烯酸基、或環氧基。其中該（i)烷氧基矽烧(alkoxysilane) 與(ii)奈米無機粉體的重量比為0.1〜3 : 1。 (i) 烧氧基矽烧（alkoxysilane)可包括具有乙烯基 (vinyl)、丙烯酸基(acryl)、胺基（amino)、環氧基（epoxy)、 羧酸基（carboxylic acid )、羥基(hydroxyl)或異氰酸酯基 (isocyanate)官能基之矽氧烷。（ii)奈米無機粉體可為矽石 (Si02, silica)粉體、Ti02、或 ai2〇3 〇 (ii) 奈米無機粉體可由濕式合成法利用溶劑、水、金屬 氧化物及觸媒合成而得到，其中該濕式合成法所使用之金 屬氧化物包括：矽氧化合物、鈦氧化合物、或锆氧化合物。 (H)奈米無機粉體可由市售之無機粒子或無機粒子溶液而 得。較佳者’（ii)奈米無機粉體之粒徑為1〜1〇〇〇nm。 硬質塗膜組成物更包括（C)添加劑可為反應型或大分 子型添加劑。利用反應型添加劑解決因小分子造成釋氣 (outgassing)的問題。（C)添加劑具有反應官能基，如羥基、 乙烯基或丙烯酸基、或環氧基等，以與感光樹脂反應， 0954-A22125TWF(N2)；P54960007TW；claire 8 1333559 並可視情況與(B)反應型無機填料反應。（C)添加劑可為具 有反應官能基之聚石夕氧烧（silicone)或其他種類之界面活性 劑。 硬質塗膜組成物更包括（D)光起始劑，其在照射能量 時，可產生起始交聯反應之活性物質（例如，自由基、陽離 子或陰離子等）。較佳之光起始劑包括：苯乙酮類 (Acetophenone)、安息香類（benzoin)、二苯曱酮類 (benzophenone)、°塞 17頓酿]類（Thioxanthone)、蒽酉昆類 (anthraquinone)起始劑等。前述光起始劑除可單一使用外亦 可混合使用，以得到較高的感光速度。 除上述成分外，硬質塗膜組成物為增進塗料性質可視 需要添加其他成份如：界面活性劑、平坦劑、消泡劑、或 接著助劑等。這些添加劑的功能跟含量乃為此技藝人士所 熟知，故在此不予贅述。 在基底10上形成硬質塗膜11之後。接著，在硬質塗 膜11上形成疊層16，疊層16係由至少一第一材料層12 及至少一第二材料層13交替堆疊。其中，第一材料層12 具有第一折射率，第二材料層13具有第二折射率，且第一 折射率不等於第二折射率。第一材料層12及第二材料層 13可包括金屬氧化物。疊層16中，第一材料層12及第二 材料層13的層數並不限定，第一材料層12及第二材料層 13可為複數層，疊層16的層數以雙數層為佳。 在一例子中，當第一折射率大於第二折射率時，第一 材料層 12 可包括 Nb2〇5、Bi2〇3、Ce〇2、Cr203 或 Ti02，且 0954-A22125TWF(N2)；P54960007TW；claire 9 1333559 其具有厚度約20奈米至70奈米；第二材料層13可包括 Si02、Al2〇3、Ge203、Y203 或 MgO，其具有厚度約 30 奈 米至150奈米。較佳者，第一折射率可約介於2.2至2.5， 第二折射率可約介於1.4至1.8。 舉例而言，在基底10上形成硬質塗膜Π之後，利用 雙極直流式脈衝藏鍵（bipolar DC pulse sputtering)法在硬 質塗膜11上形成厚度約為20至70奈米如為Nb205的第一 材料層12，接著，利用雙極直流式脈衝濺鍍法在第一材料 • 層12上形成厚度約為30至100奈米如為Si02的第二材料 層13。之後，重複上述製程，在第二材料層13形成厚度 約20至70奈米的第一材料層12，在第一材料層12形成 厚度約為50至150奈米的第二材料層13,如第1圖所示。 值得注意的是，雙極直流式脈衝濺鍍法之脈衝直流電 源可瞬間產生高功率，藉此，不但加速靶材沈積速率而增 進濺鍍速率，還可提高靶材沈積密度而提升鍍膜品質。 藉由本發明提供之實施例，硬質塗膜11上之疊層16 ® 可作為抗反射膜，光學薄膜100可應用於液晶顯示器，以 消除顯示器之表面眩光。第2圖係繪示利用本發明實施例 之光學薄膜之抗反射率，此圖係量測具有利用雙極直流式 脈衝濺鍍法形成之疊層的光學薄膜，其中此疊層包括兩層 高折射率金屬氧化物層與兩層低折射率金屬氧化物層交錯 形成在硬質塗膜上。在硬質塗膜上的高折射率金屬氧化物 層為Nb205,其厚度約為23nm，且折射率約為2.2至2.3 ; 在此高折射率金屬氧化物層上的低折射率金屬氧化物層為 0954-A22125TWF(N2)；P54960007TW：claire 10 13335591333559 IX. Description of the Invention: [Technical Field] The present invention relates to an optical film and a method of forming the same, and more particularly to an optical film having an anti-reflection function and a method of forming the same. [Prior Art] The substrate of the optical plastic film itself has the disadvantages of low hardness, non-wearing B consumption, and particularly high application requirements in the photovoltaic industry, so that the surface requires high-precision, high-performance protective coating. With the continuous expansion of the five-generation and six-generation plants, Taiwan's display will become the world's largest LCD producer in recent years, and for the development of technology, in order to improve durability and use without interference from external light, LCD optical film Related processing technologies, such as hard coating and anti-glare, anti-reflection have become one of the key technologies that are indispensable. The properties of hard coatings for sputtering are more stringent than those of ordinary hard coatings. For example, in the process of using an anti-reflection film for a liquid crystal display, it is necessary to form a hard coating film and then vacuum sputtering on the hard coating film to form an anti-reflection film, so that the underlying hard coating film must be able to be avoided under vacuum. Outgassing, and still maintains high hardness after antimony ore. Among them, the formation of the anti-reflection film faces problems such as slow production speed and poor coating quality. In the prior art, Shin-Etsu uses U.S. Patent No. 5,021,091 to develop a hard coating material using a UV resin, a sinter and an inorganic submicron filler. Ito Optics developed the hard 0954-A22125TWF (N2); P54960007TW; claire 5 1333559 coating film material using decane and epoxy resin formulations in the early publications JP 05-98214 and JP 10-168389. DSM developed a hard coating material from U.S. Patent No. 6,013,749 using a UV resin, a stone smelting furnace, a silic 〇ne, and a nano-sized silica filler. The applicant of the present invention also discloses a hard coating film composition and a hard coating film, which can be used as a hard coating film for hiding keys, which can solve the outgassing and warping of the prior art in the Republic of China Patent Application No. 94147659. And static electricity and other issues. The invention further provides an optical film and a method for forming the same, and the optical film provided by the embodiment of the invention has anti-reflection and anti-glare functions. The present invention provides an optical film comprising: a substrate; a laminate on which the at least one first material layer and the at least one second material layer are alternately stacked, wherein the first material layer has a first refractive index, the second material layer has a second refractive index, the first refractive index is not equal to the second refractive index; and a hard coating film between the substrate and the laminate. The composition of the hard coating film includes: (Α) a photosensitive resin containing a polyfunctional methacrylate; (Β) a reactive inorganic filler 'by (i) alkoxysilane and (alkoxysilane) Ii) a reaction of nano inorganic powder; (C) an additive; and (D) a photoinitiator. The present invention further provides a method of forming an optical film, comprising: providing a substrate; forming a laminate on the substrate, the laminate being alternately stacked by at least one first material layer and at least one second material layer, wherein the A material layer has a first refractive index, the second material layer has a second refractive index, the first refractive index is not equal to the second refractive index; and the substrate and the laminate 0954-A22125TWF(N2): A hard coating film is formed between P54960007TW and claire 6 1333559. The composition of the hard coating film comprises: (A) a photosensitive tree yttrium containing polyfunctional methacrylate, and (B) a reactive inorganic filler '(1) a oxy-chemical stone garden (aik〇XySiiane丨 and (ii) a reaction of a nano-inorganic powder; (C) an additive; and (D) a photoinitiator. [Embodiment] The following is a detailed description of the embodiments as a reference for the present invention. In the drawings, the same reference numerals are used. In the drawings, the shape or thickness of the elements may be expanded, and the elements not shown or described in the drawings may have various forms known to those skilled in the art. In addition, when a layer is described on a substrate or another layer, the layer may be directly on the substrate or another layer, or may have an interposer therebetween. Referring to Figure 1, the present invention is shown by the present invention. Optical film of the embodiment. In one example, the optical film 100 can be applied to a liquid crystal display. First, the substrate 10 is provided. Preferably, the substrate 10 is a transparent substrate, and the substrate 10 can comprise a glass substrate, a plastic substrate or Next, a hard coating film 11 is formed on the substrate 10, and the hard coating film 11 can be formed by photocuring a hard coating film composition. The hard coating film composition includes (A) a polyfunctional mercapto propylene-containing compound. Photosensitive resin of p@iyfUnctional methacrylate. The polyfunctional mercapto acrylate may be a monomer or an oligomer, and may be used singly or in combination of two or more, preferably, for example, .1, - 1,4-butanediol di(meth)acrylate' 1,6-hexanediol di(meth)acrylate It should be noted that although the photosensitive resin of the invention of 0954-A22l25TWF(N2): P54960007TW; claire 7 1333559 is preferably uv curable resin, it can also be visible light, electron beam, ray. Other photo-curing resin systems. The hard coating composition further includes (B) a reactive inorganic filler 'by reacting (1) alkoxysilane with (ii) a nanothermal heat powder. The surface of rice flour is introduced into an organic functional group that can participate in the reaction to make inorganic nanoparticles The body may be uniformly dispersed and reacted with the photosensitive resin. The reactive inorganic filler preferably has at least one functional group capable of reacting with the (A) photosensitive resin: an ethylene-based group, an acrylic group, or an epoxy group, wherein the (i) alkane The weight ratio of alkoxysilane to (ii) nano inorganic powder is 0.1 to 3: 1. (i) Alkoxysilane may include vinyl, acrylic (acryl) a oxane of an amino group, an epoxy group, a carboxylic acid, a hydroxyl group or an isocyanate functional group. (ii) The nano-inorganic powder may be a SiO 2 (SiO 2 ) powder, TiO 2 or ai 2 〇 3 〇 (ii) Nano inorganic powder may be subjected to a wet synthesis method using a solvent, water, a metal oxide and a touch The metal oxide used in the wet synthesis method comprises an anthracene oxygen compound, a titanium oxide compound, or a zirconium oxide compound. (H) Nano inorganic powder can be obtained from commercially available inorganic particles or inorganic particle solutions. Preferably, the diameter of the (ii) nano-inorganic powder is 1 to 1 〇〇〇 nm. The hard coating composition further includes (C) the additive may be a reactive or macromolecular additive. Reactive additives are used to solve the problem of outgassing caused by small molecules. (C) The additive has a reactive functional group such as a hydroxyl group, a vinyl group or an acrylic group, or an epoxy group to react with the photosensitive resin, 0954-A22125TWF(N2); P54960007TW; claire 8 1333559 and optionally reacts with (B) Type inorganic filler reaction. The (C) additive may be a silicone or other type of surfactant having a reactive functional group. The hard coating composition further includes (D) a photoinitiator which, upon irradiation of energy, produces an active substance (e.g., a radical, a cation or an anion, etc.) which initiates a crosslinking reaction. Preferred photoinitiators include: acetophenone, benzoin, benzophenone, Thioxanthone, anthraquinone Starter and so on. The above photoinitiators may be used in combination in addition to single use to obtain a higher photospeed. In addition to the above ingredients, the hard coating composition may be added with other ingredients such as a surfactant, a flat agent, an antifoaming agent, or a auxiliary agent to enhance the properties of the coating. The function and content of these additives are well known to those skilled in the art and will not be further described herein. After the hard coating film 11 is formed on the substrate 10. Next, a laminate 16 is formed on the hard coating film 11, and the laminate 16 is alternately stacked by at least one first material layer 12 and at least one second material layer 13. Wherein the first material layer 12 has a first refractive index, the second material layer 13 has a second refractive index, and the first refractive index is not equal to the second refractive index. The first material layer 12 and the second material layer 13 may include a metal oxide. In the laminate 16, the number of layers of the first material layer 12 and the second material layer 13 is not limited, and the first material layer 12 and the second material layer 13 may be a plurality of layers, and the number of layers of the layer 16 is preferably a double layer. . In an example, when the first refractive index is greater than the second refractive index, the first material layer 12 may include Nb2〇5, Bi2〇3, Ce〇2, Cr203, or TiO2, and 0954-A22125TWF(N2); P54960007TW; Claire 9 1333559 having a thickness of from about 20 nm to about 70 nm; the second material layer 13 may comprise SiO 2 , Al 2 〇 3, Ge 203, Y 203 or MgO having a thickness of from about 30 nm to about 150 nm. Preferably, the first index of refraction may be between about 2.2 and 2.5 and the second index of refraction may be between about 1.4 and 1.8. For example, after the hard coating film is formed on the substrate 10, a thickness of about 20 to 70 nm, such as Nb205, is formed on the hard coating film 11 by a bipolar DC pulse sputtering method. A material layer 12 is then formed on the first material layer 12 by a bipolar direct current pulse sputtering method to form a second material layer 13 having a thickness of about 30 to 100 nanometers, such as SiO 2 . Thereafter, the above process is repeated, a first material layer 12 having a thickness of about 20 to 70 nm is formed in the second material layer 13, and a second material layer 13 having a thickness of about 50 to 150 nm is formed in the first material layer 12, such as Figure 1 shows. It is worth noting that the pulsed DC power supply of the bipolar DC pulse sputtering method can generate high power instantaneously, thereby not only accelerating the target deposition rate but also increasing the sputtering rate, and also increasing the deposition density of the target to improve the coating quality. With the embodiment of the present invention, the laminate 16 ® on the hard coating film 11 can be used as an antireflection film, and the optical film 100 can be applied to a liquid crystal display to eliminate surface glare of the display. Figure 2 is a graph showing the reflectance of an optical film using an embodiment of the present invention. The figure is an optical film having a laminate formed by a bipolar direct current pulse sputtering method, wherein the laminate comprises two layers of high The refractive index metal oxide layer and the two low refractive index metal oxide layers are interleaved on the hard coating film. The high refractive index metal oxide layer on the hard coating film is Nb205 having a thickness of about 23 nm and a refractive index of about 2.2 to 2.3; the low refractive index metal oxide layer on the high refractive index metal oxide layer is 0954-A22125TWF(N2); P54960007TW: claire 10 1333559
Si〇2，其厚度約為36nm，且折射率約為1.4至1.5 ;在此 低折射率金屬氧化物層上的高折射率金屬氧化物層為 Nb205，其厚度約為40nm，且折射率約為2·2至2.3 ;在此 高折射率金屬氧化物層上的低折射率金屬氧化物層為 Si〇2，其厚度約為l〇8nm，且折射率約為1.4至1.5。由圖 中顯示，當光波長約450至650奈米時，本發明實施例之 光學薄膜的抗反射率約可達0.507。 雖然本發明已以較佳實施例揭露如上，然其並非用以 限定本發明，任何熟習此技藝者，在不脫離本發明之精神 和範圍内，當可作些許之更動與潤飾，因此本發明之保護 範圍當視後附之申請專利範圍所界定者為準。Si〇2 has a thickness of about 36 nm and a refractive index of about 1.4 to 1.5; the high refractive index metal oxide layer on the low refractive index metal oxide layer is Nb205 having a thickness of about 40 nm and a refractive index of about It is from 2·2 to 2.3; the low refractive index metal oxide layer on the high refractive index metal oxide layer is Si〇2, which has a thickness of about 10 nm and a refractive index of about 1.4 to 1.5. As shown in the figure, the optical film of the embodiment of the present invention has an antireflection rate of about 0.507 when the wavelength of light is about 450 to 650 nm. While the present invention has been described in its preferred embodiments, the present invention is not intended to limit the invention, and the present invention may be modified and modified without departing from the spirit and scope of the invention. The scope of protection is subject to the definition of the scope of the patent application.
0954-A22125TWF(N2);P5496000丌 W:claire 11 1333559 【圖式簡單說明】 第1圖係繪示本發明實施例之光學薄膜；以及 第2圖係繪示利用本發明實施例之光學薄膜的抗反射 【主要元件符號說明】 100〜光學薄膜； 10〜基底； 11〜硬質塗膜； 12〜第一材料層； 13〜第二材料層； 16〜疊層。 0954-A22125TWF(N2) ：P54960007TW：claire0954-A22125TWF(N2); P5496000丌W:claire 11 1333559 BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an optical film according to an embodiment of the present invention; and FIG. 2 is a view showing an optical film using an embodiment of the present invention. Anti-reflection [Main component symbol description] 100~ optical film; 10~ substrate; 11~ hard coating film; 12~ first material layer; 13~ second material layer; 0954-A22125TWF(N2) :P54960007TW:claire