201033643 六、發明說明： 【發明所屬之技術領域】 本發明係關於可作爲液晶顯示裝置之光學構件的基質 薄膜使用的光學用層合薄膜。 【先前技術】 聚醋薄膜可作爲液晶顯示裝置之光學構件的稜鏡薄片 φ 等基質薄膜使用。 近年來，液晶顯示裝置之薄型化正進展著，對於構成 液晶顯示裝置之光學構件’要求薄膜化與片數之減少。其 中作爲基質薄膜’該自體具備光擴散性之聚酯薄膜已被提 案。 例如特開2001-272508號公報或特開2001-272511號 公報中記載，使於薄膜內部含有光擴散成分時，於基質薄 膜自體可賦予光擴散性。又，特開2002-178472號公報中 • 記載，使於薄膜內部含有球狀或凸透鏡狀粒子時，於基質 薄膜自體可賦予光擴散性。 【發明內容】 [欲發明解決之課題] 液晶顯示裝置之光學構件爲裝置於液晶顯示裝置而使 用。然而，藉由過去技術的基質薄膜，因與其他構件之摩 擦較爲大，故裝置於液晶顯示裝置的背光中時，會與其他 構件貼合，使得裝置光學構件時的操作性顯著降低。又， -5- 201033643 藉由液晶顯示裝置之使用環境中的熱或濕度會使得光學構 件之尺寸變化很大，光學構件會彎曲，其結果作爲光擴散 薄膜使用時，於液晶顯示裝置會產生亮度斑。 本發明提供一種作爲光擴散薄膜使用時的亮度斑較少 ，且可隱蔽發射線，具備優良光擴散性，況且組裝於背光 單位時，與鄰接之構件的結塊被抑制之光學用層合薄膜作 爲課題。 本發明提供一種進一步設置稜鏡層或擴散珠子層，作 @ 爲液晶顯示裝置之光學構件使用時，可得到提高亮度之效 果的光學用層合薄膜作爲課題。 [欲解決課題之手段] 即，本發明係由光擴散層及於此上所設置密著防止層 所成之光學用層合薄膜，密著防止層係由聚酯及塡料所成 之二軸配向的層，實質上未含有空隙，其表面粗度Rz爲 400〜5 OOOnm，光擴散層係由比密著防止層的聚酯之熔點 0 還低5〜5〇°C之聚酯及光擴散成分所成爲特徵之光學用層 合薄膜。 [發明之效果] 本發明爲提供一種作爲光擴散薄膜使用時的亮度斑較 少，且可隱蔽背光之發射線，具備優良光擴散性，且組裝 於背光單位時，與鄰接之構件的結塊受到抑制之光學用層 合薄膜。 -6- 201033643 • 本發明爲提供一種進一步設置稜鏡層或擴散珠子層， 作爲液晶顯示裝置之光學構件使用時，可得到提高亮度效 果的光學用層合薄膜。 [實施發明之最佳形態] 本發明的光學用層合薄膜係由光擴散層及設置此上的 密著防止層所成。以下詳細說明本發明。由密著防止層來 φ 說明。 密著防止層 密著防止層係由聚酯及塡料所成之二軸配向的層。若 • 非二軸配向之層時，熱收縮率會變高，藉由液晶顯示裝置 之背光單位的光源之熱，薄膜會變形、或產生背光單位之 亮度斑。 密著防止層爲實質上未含有空隙。本發明中實質上未 0 含有空隙時’表示未含有空隙、或含有不會使密著防止層 之全光線透過率降低的程度之空隙，例如將密著防止層於 薄膜面切斷成垂直時的空隙之截面積爲塡料截面積之50% 以下’較佳爲30%以下而言。密著防止層若實質上含有空 隙時，在空隙界面之光反射會變多，薄膜全光線透過率爲 降低，使得亮度劣化。密著防止層若實質上未含空隙時， 將薄膜之截面以掃描型顯微鏡（SEM )或透過型顯微鏡（ TEM )觀察時可由500倍〜20000倍之倍率下確認。 密著防止層之表面粗度Rz爲400〜5000nm，以1 500 201033643 〜45 OOnm爲佳。Rz未達4〇Onm時，粗度會不足’在組裝 於液晶顯示裝置之步驟時’會與其他構件密著’使得密著 防止之功能不足。另—方面’ Rz若爲超過5000nm時’薄 膜表面會過粗，使得薄膜全體之全光線透過率會降低。 使用於密著防止層之聚酯爲芳香族飽和聚酯。此係由 芳香族二羧酸成分與脂肪族二醇成分所成之聚酯。作爲該 聚酯，例如可舉出聚對苯二甲酸乙二醇酯、聚乙烯萘二羧 酸酯。彼等以共聚物或均聚物爲佳。最佳聚酯爲聚對苯二 @ 甲酸乙二醇酯之均聚物。 塡料之含有量將密著防止層之重量作爲基準時爲〇.〇5 〜10重量％。未達0.05重量％時，表面粗度會不足且密著 防止功能亦會不足，超過10重量％時，延伸時會產生多處 空隙，使得全光線透過率劣化。 本發明中，以於密著防止層之聚酯與塡料之界面不形 成空隙爲佳，作爲塡料使用塊狀粒子爲佳。使用塊狀粒子 時，於薄膜之延伸時會藉由延伸應力而使塊狀粒子崩壞， G 可得到在界面之剝離受到抑制之未含有空隙的密著防止層 ’且可得到具備高透明性之薄膜。作爲塊狀粒子，例如可 舉出塊狀二氧化矽粒子、硫酸鋇粒子、氧化鋁粒子、碳酸 鈣粒子，以塊狀二氧化矽粒子爲特佳。 塊狀粒子之平均粒徑較佳爲1〜ΙΟμιη，更佳爲1〜 8 μιη。平均粒徑於此範圍時，可得到具備充分表面粗度之 層合薄膜，亦可得到更優良的密著防止性，又於延伸時塡 料周圍較少產生空隙’且可變小故較佳。作爲塡料使用塊 -8 - 201033643 狀粒子時’塊狀粒子之 BET比表面積較佳爲 200〜 800m2/g。藉由該範圍，於延伸時塊狀塡料可追隨聚酯延 伸而移動’因塊狀粒子的適度崩解，而可抑制空隙之產生 光擴散層 光擴散層係由聚酯與光擴散成分所成。作爲光擴散層 φ 之聚酯，使用熔點比密著防止層之聚酯的熔點還低5〜 5 0°C之聚酯。本發明中，由得到高光線透過率之觀點來看 ，光擴散層爲實質上不含空隙者爲佳，將因薄膜延伸而產 生的光擴散層之空隙藉由薄膜之熱處理而消滅，得到實質 上未含有空隙之光擴散層爲佳。熔點差若未達時，保 持薄膜之機械性強度下，無法再熔解光擴散層之聚酯，延 伸時於光擴散成分之周圍所產生的空隙亦無法由薄膜之熱 處理而充分地消滅，熔點差超過5 0°C時，所得之薄膜的耐 φ 熱性會不足。 作爲使用於光擴散層之熔點低的聚酯，可使用共聚合 聚酯。例如作爲密著防止層之聚酯，使用聚對苯二甲酸乙 二醇酯爲佳，作爲光擴散層之聚酯，使用共聚合聚對苯二 甲酸乙二醇酯爲佳。作爲共聚合成分，其中作爲二羧酸成 分，例如可舉出如異鄰苯二甲酸、萘二羧酸之芳香族二羧 酸、如己二酸、壬二酸、癸二酸、癸烷二羧酸之脂肪族二 羧酸、如環己烷二羧酸之脂環族二羧酸。作爲二醇成分， 例如可舉出如1,4-丁烷二醇、1,6-己烷二醇、二乙二醇之 201033643 脂肪族二醇、1，4-環己烷二甲醇之脂環族二醇、如雙酚A 之芳香族二醇。彼等可單獨或使用二種以上。 例如作爲密著防止層之聚酯，使用聚乙烯萘二羧酸酯 時爲佳，作爲光擴散層之聚酯，使用共聚合聚乙烯萘二羧 酸酯者爲佳。作爲共聚合成分，其中作爲二羧酸成分，例 如可舉出如鄰苯二甲酸、異鄰苯二甲酸之芳香族二羧酸、 如己二酸、壬二酸、癸二酸、癸烷二羧酸之脂肪族二羧酸 、如環己烷二羧酸之脂環族二羧酸。作爲二醇成分，可舉 出如1，4-丁烷二醇、1，6-己烷二醇、二乙二醇之脂肪族二 醇、如1,4-環己烷二甲醇之脂環族二醇、如雙酚A之芳香 族二醇。彼等可單獨或使用二種以上。 作爲光擴散層之光擴散成分，使用與光擴散層之聚酯 的折射率相異的物質，例如使用塡料或非相溶聚合物。其 中’所謂非相溶聚合物表示光擴散層之聚酯與非相溶性聚 合物。 由容易控制形狀與粒徑來看，作爲光擴散成分以塡料 爲佳。塡料以球狀粒子爲佳，以真球狀粒子爲特佳。塡料 之真球度越高越佳，縱橫比以1.1以下爲特佳。塡料之平 均粒徑較佳爲0.5〜30μιη，更佳爲1〜20μιη。平均粒徑爲 該範圍時，因可得到充分高光擴散性與全光線透過率，故 亮度優，且可使塡料之周圍所產生的空隙變小，故藉由熱 處理容易消滅空隙。塡料以無色透明之物質爲佳。 作爲光擴散成分中之塡料，例如可使用二氧化矽粒子 、丙烯酸粒子、聚苯乙烯粒子、聚矽氧粒子、交聯丙烯酸 -10- 201033643 粒子、交聯聚苯乙烯粒子、交聯聚矽氧粒子。 作爲光擴散成分之塡料的折射率與光擴散層的聚酯之 折射率差，與光擴散成分之塡料的平均粒子徑之積（折射 率差X平均粒子徑（μηι ))以0.1〜〇·5[μιη]爲佳。該範圍 時，可得到非常良好之光擴散性。 光擴散層於二軸延伸後，可藉由比光擴散層之聚酯的 熔點還高之溫度下進行熱處理時，使配向緩和或使配向消 φ 失爲佳。若於光擴散層留下配向時，在與光擴散粒子之界 面，於延伸時所產生的空隙無法充分消失，而導致光線透 過率之降低。 層構成 本發明之光學用層合薄膜係由光擴散層及設置於此上 的密著防止層所成。光擴散層與密著防止層之厚度比率對 於光擴散層之厚度1而言，密著防止層之厚度較佳爲0.2 φ 〜5.0’更佳爲0.2〜4.0。藉由該範圍之厚度比率，可維持 機械性強度下，得到優良的光擴散性。本發明中較佳的構 成爲於光擴散層之兩側具備密著防止層之構成。 本發明的光學用層合薄膜之總厚度較佳爲10〜5 00μηι ’更佳爲10〜400 μιη。藉由該範圍之總厚度，具備光擴散 性與密著防止性之同時，延伸性亦良好，可得到生產性佳 的光學用層合薄膜。 於本發明之光學用層合薄膜的表面，視必要以不損害 本發明之效果下，塗佈基底層、或可施予電暈放電處理、 -11 - 201033643 ®發處理、火焰處理等。這些處理亦可於薄膜製造後施予 、或可於薄膜製造步驟內施予。 製造方法 以下將熔點以Tm表示，將玻璃轉移溫度以Tg表示 。又’ 「Tg (密著防止層）」表示密著防止層之聚酯的 Tg’ 「Tg (光擴散層）」表示光擴散層的聚酯之Tg，「 Tm (密著防止層）」表示密著防止層之聚酯的Tm，「Tm (光擴散層）」表示光擴散層之聚酯的Tm。 本發明中，光擴散層與密著防止層藉由共押出法而層 合。本發明之光學用層合薄膜，例如可如以下而製造。[Technical Field] The present invention relates to an optical laminated film which can be used as a base film of an optical member of a liquid crystal display device. [Prior Art] The polyester film can be used as a substrate film such as a crucible sheet φ of an optical member of a liquid crystal display device. In recent years, the thickness of the liquid crystal display device is progressing, and the optical member constituting the liquid crystal display device is required to be thinned and the number of sheets is reduced. Among them, a polyester film having a light diffusing property as a substrate film has been proposed. In the case where the light-diffusing component is contained in the film, the light-diffusing property can be imparted to the substrate film by itself, as described in Japanese Laid-Open Patent Publication No. 2001-272511. In JP-A-2002-178472, it is described that when the spherical or convex lenticular particles are contained in the film, the substrate film can impart light diffusibility to the film itself. SUMMARY OF THE INVENTION [Problem to be Solved by the Invention] The optical member of the liquid crystal display device is used in a liquid crystal display device. However, since the matrix film of the prior art has a large friction with other members, when it is mounted in the backlight of the liquid crystal display device, it is bonded to other members, so that the operability at the time of the optical member of the device is remarkably lowered. Further, -5-201033643 by the heat or humidity in the environment in which the liquid crystal display device is used, the size of the optical member is greatly changed, and the optical member is bent, and as a result, when used as a light-diffusing film, brightness is generated in the liquid crystal display device. spot. The present invention provides an optical laminated film which is used as a light-diffusing film and which has a small number of brightness spots and which can conceal an emission line and has excellent light diffusibility, and is assembled in a backlight unit, and agglomeration of an adjacent member is suppressed. As a subject. The present invention provides an optical laminated film which can provide an effect of improving the brightness when the ruthenium layer or the diffusion bead layer is further provided as an optical member of a liquid crystal display device. [Means for Solving the Problem] The present invention is an optical laminated film formed of a light-diffusing layer and an adhesion preventing layer provided thereon, and the adhesion preventing layer is made of polyester and tantalum. The layer of the axial alignment has substantially no voids, and has a surface roughness Rz of 400 to 5 OOOnm, and the light diffusion layer is made of polyester and light lower than the melting point 0 of the polyester of the adhesion preventing layer by 5 to 5 ° C. A laminated film for optics characterized by a diffusing component. [Effect of the Invention] The present invention provides a light-diffusion film which is used as a light-diffusing film and which can conceal an emission line of a backlight, has excellent light diffusibility, and is agglomerated with an adjacent member when assembled in a backlight unit. A laminated film for optics that is suppressed. -6-201033643 The present invention provides an optical laminated film which can improve the brightness effect when the ruthenium layer or the diffusion bead layer is further provided as an optical member of a liquid crystal display device. BEST MODE FOR CARRYING OUT THE INVENTION The optical laminated film of the present invention is formed of a light diffusion layer and a adhesion preventing layer provided thereon. The invention is described in detail below. Illustrated by the adhesion prevention layer φ. The adhesion prevention layer is a layer in which the adhesion prevention layer is a biaxial alignment formed by polyester and a crucible. If the layer is not a biaxial alignment layer, the heat shrinkage rate becomes high, and the film may be deformed or the brightness unit of the backlight unit may be generated by the heat of the light source of the backlight unit of the liquid crystal display device. The adhesion preventing layer has substantially no voids. In the present invention, when the void is substantially zero, it means that the void is not contained or the void which does not reduce the total light transmittance of the adhesion preventing layer is formed. For example, when the adhesion preventing layer is cut into a vertical direction on the film surface, The cross-sectional area of the void is 50% or less of the cross-sectional area of the crucible, and it is preferably 30% or less. When the adhesion preventing layer substantially contains a void, light reflection at the interface of the void is increased, and the total light transmittance of the film is lowered to deteriorate the luminance. When the adhesion preventing layer does not substantially contain a void, the cross section of the film can be confirmed by a scanning microscope (SEM) or a transmission microscope (TEM) at a magnification of 500 times to 20,000 times. The surface roughness Rz of the adhesion preventing layer is 400 to 5000 nm, preferably 1 500 201033643 to 45 00 nm. When the Rz is less than 4 〇 Onm, the thickness is insufficient. When the step of assembling the liquid crystal display device is adhered to the other members, the function of the adhesion prevention is insufficient. On the other hand, if Rz is more than 5000 nm, the surface of the film will be too thick, so that the total light transmittance of the entire film will be lowered. The polyester used in the adhesion preventing layer is an aromatic saturated polyester. This is a polyester composed of an aromatic dicarboxylic acid component and an aliphatic diol component. Examples of the polyester include polyethylene terephthalate and polyethylene naphthalate. They are preferably copolymers or homopolymers. The most preferred polyester is a homopolymer of polyethylene terephthalate @ ethylene glycolate. When the content of the coating is based on the weight of the adhesion preventing layer, it is 〇. 5 to 10% by weight. When the amount is less than 0.05% by weight, the surface roughness may be insufficient and the adhesion preventing function may be insufficient. When it exceeds 10% by weight, a plurality of voids may be generated during stretching to deteriorate the total light transmittance. In the present invention, it is preferred that the interface between the polyester of the adhesion preventing layer and the coating material is not formed into a void, and it is preferable to use the bulk particles as the coating material. When the bulk particles are used, the bulk particles are collapsed by the elongation stress when the film is stretched, and G can obtain a adhesion preventing layer which does not contain voids at the interface peeling, and high transparency can be obtained. The film. Examples of the bulk particles include bulk cerium oxide particles, barium sulfate particles, alumina particles, and calcium carbonate particles, and block cerium oxide particles are particularly preferable. The average particle diameter of the massive particles is preferably from 1 to ΙΟμηη, more preferably from 1 to 8 μηη. When the average particle diameter is in this range, a laminated film having a sufficient surface roughness can be obtained, and a more excellent adhesion prevention property can be obtained, and a void is less generated around the crucible when it is extended, and it is preferably small. . When the block -8 - 201033643 is used as the material, the BET specific surface area of the block particles is preferably 200 to 800 m 2 /g. With this range, the bulk material can follow the extension of the polyester during stretching. 'The moderate disintegration of the bulk particles can suppress the generation of voids. The light diffusion layer is composed of polyester and light diffusing components. to make. As the polyester of the light-diffusing layer φ, a polyester having a melting point lower than the melting point of the polyester of the adhesion preventing layer by 5 to 50 ° C is used. In the present invention, from the viewpoint of obtaining high light transmittance, the light diffusion layer is preferably substantially free of voids, and the voids of the light diffusion layer which are caused by the film stretching are destroyed by heat treatment of the film to obtain substantial A light diffusion layer having no voids is preferred. If the difference in melting point is not reached, the polyester of the light-diffusing layer cannot be melted under the mechanical strength of the film, and the voids generated around the light-diffusing component during stretching cannot be sufficiently eliminated by heat treatment of the film, and the difference in melting point When the temperature exceeds 50 ° C, the resulting film may have insufficient φ heat resistance. As the polyester having a low melting point for use in the light diffusion layer, a copolymerized polyester can be used. For example, polyethylene as the adhesion preventing layer is preferably polyethylene terephthalate, and as the polyester of the light-diffusing layer, copolymerized polyethylene terephthalate is preferably used. Examples of the copolymerization component include, as the dicarboxylic acid component, an aromatic dicarboxylic acid such as isophthalic acid or naphthalene dicarboxylic acid, such as adipic acid, sebacic acid, sebacic acid, and decane. An aliphatic dicarboxylic acid of a carboxylic acid, such as an alicyclic dicarboxylic acid of cyclohexanedicarboxylic acid. Examples of the diol component include 201033643 aliphatic diol such as 1,4-butanediol, 1,6-hexanediol, and diethylene glycol, and 1,4-cyclohexanedimethanol. A cyclodiol such as an aromatic diol of bisphenol A. They may be used alone or in combination of two or more. For example, a polyethylene naphthalene dicarboxylate is preferred as the polyester for the adhesion prevention layer, and a copolymerized polyethylene naphthalate is preferably used as the polyester of the light diffusion layer. As the copolymerization component, examples of the dicarboxylic acid component include aromatic dicarboxylic acids such as phthalic acid and isophthalic acid, such as adipic acid, sebacic acid, sebacic acid, and decane. An aliphatic dicarboxylic acid of a carboxylic acid, such as an alicyclic dicarboxylic acid of cyclohexanedicarboxylic acid. Examples of the diol component include aliphatic diols such as 1,4-butanediol, 1,6-hexanediol, and diethylene glycol, and alicyclic rings such as 1,4-cyclohexanedimethanol. A diol, such as an aromatic diol of bisphenol A. They may be used alone or in combination of two or more. As the light-diffusing component of the light-diffusing layer, a substance different from the refractive index of the polyester of the light-diffusing layer is used, and for example, a tantalum or an incompatible polymer is used. Here, the so-called incompatible polymer means a polyester of a light diffusion layer and a non-compatible polymer. From the viewpoint of easy control of the shape and particle diameter, it is preferred to use a light diffusing component as a light-diffusing component. The sputum is preferably spherical particles, and is particularly excellent in true spherical particles. The higher the true sphericity of the dip, the better the aspect ratio is 1.1 or less. The average particle diameter of the dip material is preferably from 0.5 to 30 μm, more preferably from 1 to 20 μm. When the average particle diameter is in this range, since sufficient light diffusibility and total light transmittance can be obtained, the brightness is excellent, and the voids generated around the material can be made small, so that the voids can be easily eliminated by heat treatment. The material is preferably a colorless and transparent substance. As the pigment in the light-diffusing component, for example, cerium oxide particles, acrylic particles, polystyrene particles, polyfluorene oxide particles, crosslinked acrylic acid-10-201033643 particles, crosslinked polystyrene particles, crosslinked polyfluorene can be used. Oxygen particles. The refractive index difference between the refractive index of the light diffusing component and the polyester of the light diffusing layer and the average particle diameter of the light diffusing component (refractive index difference X average particle diameter (μηι)) is 0.1~ 〇·5[μιη] is better. In this range, very good light diffusibility can be obtained. When the light-diffusing layer is subjected to heat treatment at a temperature higher than the melting point of the polyester of the light-diffusing layer after the biaxial stretching, the alignment is moderated or the alignment is preferably eliminated. When the alignment is left in the light-diffusing layer, the gap generated at the time of stretching with the light-diffusing particles cannot be sufficiently eliminated, resulting in a decrease in light transmittance. Layer Structure The optical laminate film of the present invention is formed of a light diffusion layer and a adhesion prevention layer provided thereon. The thickness ratio of the light diffusion layer to the adhesion prevention layer is preferably from 0.2 φ to 5.0', more preferably from 0.2 to 4.0, in terms of the thickness 1 of the light diffusion layer. By the thickness ratio of the range, excellent light diffusibility can be obtained while maintaining mechanical strength. In the present invention, it is preferable to have a structure in which the adhesion preventing layer is provided on both sides of the light diffusion layer. The total thickness of the laminated film for optics of the present invention is preferably from 10 to 50,000 μm, more preferably from 10 to 400 μm. By the total thickness of the range, the light diffusibility and the adhesion prevention property are improved, and the elongation is also good, and a laminated film for optical use having good productivity can be obtained. The surface of the optical laminated film of the present invention may be coated with a base layer or may be subjected to corona discharge treatment, -11 - 201033643 ® hair treatment, flame treatment, etc., as necessary, without impairing the effects of the present invention. These treatments can also be applied after the film is manufactured or can be applied during the film manufacturing step. Manufacturing Method The melting point is represented by Tm, and the glass transition temperature is represented by Tg. Further, "Tg (adhesion prevention layer)" indicates Tg' of the polyester of the adhesion preventing layer "Tg (light diffusion layer)" indicates the Tg of the polyester of the light diffusion layer, and "Tm (precise prevention layer)" indicates The Tm of the polyester of the adhesion preventing layer, "Tm (light diffusion layer)" represents the Tm of the polyester of the light diffusion layer. In the present invention, the light diffusion layer and the adhesion prevention layer are laminated by a co-extrusion method. The laminated film for optics of the present invention can be produced, for example, as follows.
即’構成含有球狀粒子之光擴散層的聚酯組成物、與 構成含有塊狀粒子之密著防止層的聚酯組成物之雙方聚酯 於熔融狀態下，例如於Tm (密著防止層）〜（Tm (密著 防止層）+70) °C之溫度下，由塑膜壓出成兩者接觸而成 爲未延伸層合薄膜。將未延伸層合薄膜於一軸方向（縱方 向或橫方向），於（Tg (密著防止層）-10)〜（Tg (密 著防止層）+70) °C之溫度下以3倍以上之倍率進行延伸 ，其次於上述延伸方向與直角方向在Tg (密著防止層） 〜（Tg (密著肪止層）+70 ) °C之溫度下以3倍以上之倍 率進行延伸。將經延伸所得之二軸配向薄膜，於光擴散層 之聚酯爲非晶性時，在（Tg (密著防止層）+70 ) °C〜（ Tm (密著防止層）-10) °C之溫度範圍下進行熱固定，於 光擴散層之聚酯爲結晶性時’在（Tm (光擴散層）+5) °C 201033643 〜（Tm (密著防止層）-l〇) °C之溫度範圍下進行熱固定 。藉由該熱固定步驟，經二軸延伸之光擴散層的聚酯之配 向會消失，可消滅於光擴散成分與聚酯之界面上所產生的 空隙。且，將塊狀粒子作爲塡料使用的密著防止層，可於 薄膜之延伸時藉由延伸應力而使塊狀粒子崩壞，在界面之 剝離受到抑制，成爲未含有空隙之密著防止層。 於此雖說明藉由逐次二軸延伸法之製造方法，但亦可 φ 同時以二軸延伸法進行延伸。若以同時二軸延伸法進行延 伸時，因延伸於二軸方向同時進行，故不容易產生空隙而 較佳。 且，空隙爲薄膜之延伸時，於塡料周圍因賦予應力而 產生，故於緩和延伸應力之條件下進行延伸時，可得到未 含有空隙之薄膜。 【實施方式】 φ 實施例 以下將本發明使用實施例作詳細說明。且物理性質藉 由以下方法測定、評估。 (1 )平均粒徑 將薄膜以六氟異丙醇溶解後分離塡料，將所得之塡料 使用於測定。平均粒徑之測定爲使用島津製作所製「CP-50 型 Centrifugal Particle Size Analyzer」進行。由將藉由 該測定器所得之離心沈澱曲線爲基準所算出之各粒徑的塡 -13- 201033643 料與其存在量之cumulative曲線，讀取相當於5〇mass percent之粒徑’將該値作爲上述平均粒徑（參照「粒度 測定技術」’ 242〜247頁，日刊工業新聞公司，1 975年 發行）。 (2 )折射率 •光擴散層之聚酯 將熔融押出前之聚酯成型爲板狀，以阿貝折射率計（ D線5 8 9nm )進行測定。 •光擴散成分（塡料） 將光擴散成分之塡料懸浮於折射率相異之種種25 °C的 液中，將懸濁液最透明之液體的折射率藉由阿貝折射率計 (D線5 89nm )測定。 (3 )縱橫比 將薄膜固定於掃描型電子顯微鏡用試料台，使用曰本 電子（股）製濺鍍裝置（JIS-11 〇〇型離子濺鍍裝置），於 薄片表面，lxl〇_3torr之真空下，以〇.25kV、1.25mA的條 件下施予1〇分鐘的離子蝕刻處理。以（股）日立製掃描 型電子顯微鏡S-4700，對於1〇〇個粒子測定長徑與短徑並 算出縱橫比，該平均値作爲縱橫比。 (4 )空隙 -14- 201033643 將薄膜以切片機於厚度方向進行切斷，將切截面以（ 股）日立製掃描型電子顯微鏡S-4 700進行觀察，計算出 對於粒子或塡料之截面積的空隙截面積之比率。對於至少 10點，算出對於塡料之截面積的空隙截面積之比率，並藉 由該平均値，以下述評估基準評估空隙。 〇：空隙截面積爲30%以下 △:空隙截面積超過30%超，50%以下 φ X:空隙截面積超過50% (5)熔點·玻璃轉移溫度 將各分離各層所得之樣品1 〇mg封入於測定用鋁製鍋 ，並裝上差示熱量計（Dupont公司製· V4.0B2000型 DSC )，由25°C以20°C/分鐘的速度昇溫至3 00°C，測定熔 點，於300 °C下保持5分鐘後取出，馬上移至冰上使其急 冷。將該鍋子再次裝上差示熱量計，由25 °C以20 °C/分的 φ 速度昇溫，測定玻璃轉移溫度。 (6)表面粗度 使用小坂硏究所公司製之表面粗度測定器SE-3FAT， 藉由JIS B0601之測定法，求得薄膜表面之十點平均粗度 Rz 〇 (7)全光線透過率 以JIS K7361爲準，使用日本電色工業公司製之霧値 -15- 201033643 測定器（NDH-2000 )，測定薄膜之全光線透過率。 (8 )霧値 依據JIS K7136，使用日本電色工業公司製之霧値測 定器（NDH-2000 )，測定薄膜之霧値。 (9 )光擴散性 依據DIN 5036，使用（股）村上色彩技術硏究所製自 動變角計GP-200，在受光角度5度、20度及70度下測定 亮度値，藉由下述式算出光擴散率，作爲光擴散性之評估 〇 光擴散率（％)=(在20度之亮度値+在70度之亮度値 )xl00/(在5度之亮度値χ2) (10 )亮度斑 由索尼（股）製液晶電視KDL-32V2500取出背光單 位’於光擴散板上載持評估對象之薄膜，以大塚電子（股 )製亮度計MC-94〇 ’對於中心點左右之螢光管上（a)、 與進一步鄰接的螢光管之間上（b)的各3處進行亮度（ cd/m2 )之測定。亮度相對値以下述式算出，作爲亮度斑 之評估。且，螢光管彼此之間隔爲23 mm。 亮度相對値=亮度（a)/亮度（b) 〇：相對亮度値爲1.1以下 △:相對亮度値超過1 · 1，1.2以下 -16- 201033643 χ :相對亮度値超過1.2，1.3以下 (1 1 )密著防止性 由索尼（股）製液晶電視KDL-32V2500取出背光單 位，於光擴散板上載持評估對象之薄膜，著重亮點產生程 度並觀察其密著程度，作爲密著防止性之評估》 〇：即使由任何角度進行觀察，幾乎無亮點產生。 φ △:將薄膜由斜面進行觀察時，1處以上產生亮點。 χ:將薄膜由正面進行觀察時，1處以上產生亮點。 (12 )各層厚度 將樣品切成三角形’固定於包埋於膠囊後，以環氧樹 脂進行包埋。然後將經包埋之樣品以切片機（ ULTRACUT-S)於縱方向切成平行截面爲50nm厚度之薄 膜切片後，使用透過型電子顯微鏡，以加速電壓1 〇〇kv進 ❹ 行觀察攝影，由照片測定各層厚度，求得平均厚度。 (13 )薄膜厚度 將薄膜樣品以電氣測微器（Electrical Micrometer) (Anritsu製K-402B) ’測定10點厚度，將平均値作爲 薄膜厚度。 (1 4 )稜鏡層之作成 於各薄膜以滴管滴入UV硬化性樹脂2g，其後載持於 -17- 201033643 頂角90°、頂角傾斜度50μιη、稜鏡高度25μπι之稜鏡成形 用版，於薄膜前面拉伸UV硬化性樹脂。於此將調整爲 30 0mJ/cm2之3 65nm的UV光，由薄膜側進行2次照射， 使UV硬化性樹脂充分硬化。硬化後將稜鏡成形用版自薄 膜剝離後成爲附有稜鏡層之樣品。作爲UV硬化性樹脂， 使用MicroSharp製MCL555 C折射率1.55〜1·58)。稜鏡 作成後，確認稜鏡之形狀於截面SEM上作成如稜鏡成形 用的版。 作爲使用於提高亮度效果之評估的基準樣品，準備全 光線透過率92%、霧値0.5%、薄膜厚度75 μπι下未添加塡 料之聚對苯二甲酸乙二醇酯薄膜，同樣下作成稜鏡層，作 爲附有稜鏡層之基準樣品。 (15)擴散珠子層之作成 於薄膜上，以Mayer bar #14塗佈下述所示組成之塗 液。其後，於100 °C之烤箱進行1分鐘乾燥，將樹脂充分 硬化。其後，以6 0 °C下進行2 4小時熟成處理，將薄膜與 珠子層進一步強固地密著，成爲附有珠子層之樣品。 作爲使用於提高亮度之效果的評估之基準樣品，準備 全光線透過率92%、霧値0.5%、薄膜厚度75μιη下無添加 塡料之聚對苯二甲酸乙二醇酯薄膜，同樣地作成擴散珠子 層’成爲附有擴散珠子層之基準樣品。 塗液： •日本觸媒（股）公司製「YudaburuS-2740」： 201033643 • 128重量份 •日本聚尿烷工業（股）公司製「CORONET HL」： 1 8重量份 •甲基乙基酮： 105重量份 •甲苯： 1 〇 5重量份 •積水化成品工業（股）公司製「MBX-20」（平均 粒徑20μιη之丙烯酸粒子）： 192重量份 (16)提高亮度之效果 由索尼（股）製液晶電視KDL-32V2500取出背光單 . 位’於光擴散板上載持評估對象之薄膜，以大塚電子（股 . )製亮度計MC-940，測定於畫面中心點之亮度（cd/m2) 。亮度提高率由下述式算出，評估提高亮度之效果。 亮度提高率（％) =亮度（a)/基準樣品亮度（b) XI 00 ◎:亮度向上率爲超過120% ❿ 〇：亮度向上率爲超過1 1 0 %，1 2 0 %以下 △:亮度向上率爲超過1 0 0 %，1 1 0 %以下 X :亮度向上率爲loo%以下 實施例1 層構成爲密著防止層/光擴散層/密著防止層。添加平 均粒徑1·7μιη之塊狀二氧化矽塡料至於聚對苯二甲酸乙二 醇酯爲0.08重量％，而準備密著防止層用之組成物。另一 方面，將平均粒徑2. Ομιη之真球狀塡料添加於異鄰苯二甲 -19- 201033643 酸（以下稱爲「ΙΑ」）12莫耳％經共聚合之共聚合聚對苯 二甲酸乙二醇酯中至2重量％，而準備光擴散層用之組成 物。各熔融彼等組成物，成爲密著防止層/光擴散層/密著 防止層之層合構成，由塑膜擠出後在澆鑄輥筒上急冷而得 到層合薄片。其後，在75°C預熱，在延伸溫度U〇°C於縱 方向延伸至3.3倍，在11(TC進行預熱，在延伸溫度130 °C 於橫方向延伸至3.6倍。其後，於結晶化區域以23 5 °C進 行熱處理後得到層合薄膜。且，進行熱處理時，於縱方向 鬆弛1.5%及於橫方向鬆弛2.0%，調整熱收縮率。評估結 果如表1所示。 實施例2 將密著防止層用之組成物與光擴散層用之組成物變更 爲表1所記載以外，與實施例1同様地得到層合薄膜。 實施例3 將密著防止層用之組成物與光擴散層用之組成物變更 爲如表1所記載，將層合構成作爲2層（密著防止層/光 擴散層），其他與實施例1同樣下得到層合薄膜。 比較例1 除未設置密著防止層以外，與實施例1同樣下進行製 膜而得到薄膜。因未有密著防止層，故欲消失光擴散層之 空隙而進行充分熱處理（ 23 5 °C)時，會使薄膜破裂而無 -20- 201033643 法安定地製膜，故將熱處理溫度降爲2 20°C而取得薄膜。 因熱處理未充分故於光擴散層存在多數空隙，成爲全光線 透過率較劣化之薄膜。 比較例2 除於密著防止層未添加塡料以外，與實施例1同様下 製膜而得到層合薄膜。因於密著防止層未添加塡料，故表 φ 面粗度不足下組裝於背光單位時，與其他光學薄膜會密著 。又，因不均勻地密著，故亮度斑會顯著。 . 比較例3 作爲密著防止層的塡料，使用比表面積較少的塊狀二 氧化矽塡料’與實施例1同樣地，經製膜得到層合薄膜。 因塡料未崩解’故於密著防止層之塡料周圍產生多數空隙 。因此’全光線透過率變差，不適合作爲光學薄膜使用。 -21 - 201033643 m ηThat is, both the polyester composition constituting the light-diffusing layer containing spherical particles and the polyester composition constituting the adhesion preventing layer containing the bulk particles are in a molten state, for example, Tm (adhesion prevention layer) ) (Tm (adhesion prevention layer) + 70) At a temperature of ° C, the plastic film is pressed and brought into contact with each other to form an unstretched laminated film. The unstretched laminated film is three times or more in the axial direction (longitudinal direction or transverse direction) at a temperature of (Tg (adhesion prevention layer)-10) to (Tg (adhesion prevention layer) + 70) °C. The magnification is extended, and the extension direction and the orthogonal direction are extended at a magnification of 3 times or more at a temperature of Tg (adhesion prevention layer) to (Tg (closed adhesion layer) + 70) °C. When the polyester of the light diffusion layer is amorphous, the (Tg (adhesion prevention layer) +70) °C~(Tm (adhesion prevention layer)-10) ° Heat setting in the temperature range of C, when the polyester of the light diffusion layer is crystalline, 'at (Tm (light diffusion layer) + 5) °C 201033643 ~ (Tm (adhesion prevention layer) - l〇) °C Heat setting at a temperature range. By the heat-fixing step, the alignment of the polyester of the light-diffusing layer which is biaxially stretched disappears, and the void generated at the interface between the light-diffusing component and the polyester can be eliminated. Further, the blocking preventing layer used as the coating material can cause the bulk particles to collapse due to the elongation stress during the stretching of the film, and the peeling at the interface is suppressed, and the adhesion preventing layer having no voids is formed. . Although the manufacturing method by the sequential biaxial stretching method is described here, it is also possible to simultaneously extend φ by the biaxial stretching method. When the stretching is carried out by the simultaneous biaxial stretching method, since the stretching is performed simultaneously in the two-axis direction, it is preferable that voids are not easily generated. Further, when the void is formed by stretching the film, stress is generated around the material. Therefore, when the film is stretched under the condition of relaxing the elongation stress, a film having no voids can be obtained. [Embodiment] φ Example Hereinafter, the present invention will be described in detail using an embodiment. The physical properties were determined and evaluated by the following methods. (1) Average particle diameter The film was dissolved in hexafluoroisopropanol, and the mash was separated, and the obtained mash was used for measurement. The measurement of the average particle diameter was carried out using "CP-50 type Centrifugal Particle Size Analyzer" manufactured by Shimadzu Corporation. From the cumulative curve of 塡-13-201033643 and the amount of each particle diameter calculated from the centrifugal sedimentation curve obtained by the measuring device, the particle diameter corresponding to 5 〇mass percent is read as the 値The above average particle size (refer to "Grain Particle Size Measurement Technology"' 242~247 pages, Nikkan Kogyo Shimbun, issued in 1975). (2) Refractive index: Polyester of light-diffusing layer The polyester before melt-extrusion was molded into a plate shape, and was measured by an Abbe refractometer (D line 889 nm). • Light-diffusing component (draft) The material of the light-diffusing component is suspended in a liquid of various refractive indices at 25 ° C, and the refractive index of the liquid which is the most transparent of the suspension is measured by an Abbe refractometer (D). Line 5 89 nm) was determined. (3) Aspect ratio The film is fixed to a sample table for a scanning electron microscope, and a sputtering device (JIS-11 〇〇 type ion sputtering device) made of a sputum electron (strand) is used on the surface of the sheet, lxl 〇 _3torr Ion etching treatment was carried out for 1 minute under vacuum at a temperature of 2525kV and 1.25mA. A scanning electron microscope S-4700 (manufactured by Hitachi) was used to measure the major axis and the minor axis for one particle, and the aspect ratio was calculated, and the average 値 was used as the aspect ratio. (4) Void-14- 201033643 The film was cut in the thickness direction by a microtome, and the cross section was observed with a scanning electron microscope S-4 700 (Hyper), and the cross-sectional area for the particles or the dip was calculated. The ratio of the cross-sectional area of the gap. For at least 10 points, the ratio of the cross-sectional area of the void to the cross-sectional area of the dip material was calculated, and by this average enthalpy, the void was evaluated on the basis of the following evaluation criteria. 〇: The cross-sectional area of the void is 30% or less. △: The cross-sectional area of the void is more than 30% super, 50% or less φ X: The cross-sectional area of the void is more than 50%. (5) Melting point and glass transition temperature The sample obtained by separating each layer is enclosed in 〇mg. The aluminum pan for measurement was equipped with a differential calorimeter (DSC model V4.0B2000 manufactured by Dupont Co., Ltd.), and the temperature was raised to 300 ° C at a rate of 20 ° C / min at 25 ° C, and the melting point was measured at 300 ° C. After 5 minutes at ° C, take it out and immediately transfer it to ice to quench it. The pot was again charged with a differential calorimeter and heated at 25 ° C at a φ speed of 20 ° C / min to measure the glass transition temperature. (6) The surface roughness was measured by the surface roughness measuring device SE-3FAT manufactured by Kobelka Co., Ltd., and the ten-point average roughness Rz 〇 (7) of the film surface was determined by the measurement method of JIS B0601. The total light transmittance of the film was measured using a smog -15-201033643 measuring device (NDH-2000) manufactured by Nippon Denshoku Industries Co., Ltd., in accordance with JIS K7361. (8) Haze The haze of the film was measured in accordance with JIS K7136 using a haze meter (NDH-2000) manufactured by Nippon Denshoku Industries Co., Ltd. (9) Light diffusivity According to DIN 5036, the automatic angle meter GP-200 manufactured by Murakami Color Technology Co., Ltd. is used to measure the brightness 5 at the light receiving angles of 5 degrees, 20 degrees and 70 degrees, by the following formula Calculate the light diffusivity as an evaluation of light diffusivity. The light diffusivity (%) = (brightness at 20 degrees 値 + brightness at 70 degrees 値) xl00 / (brightness at 5 degrees 値χ 2) (10) brightness spots The backlight unit of the LCD TV KDL-32V2500 made by Sony (share) is used to carry the film of the evaluation object on the light diffusing plate, and the brightness meter MC-94〇' is used for the fluorescent tube around the center point ( a) Measurement of luminance (cd/m2) at each of three places (b) between the adjacent adjacent fluorescent tubes. The luminance is calculated by the following equation as the evaluation of the luminance spot. Moreover, the fluorescent tubes are spaced apart from each other by 23 mm. Brightness relative 値 = brightness (a) / brightness (b) 〇: relative brightness 値 is 1.1 or less △: relative brightness 値 exceeds 1 · 1, 1.2 or less - 16 - 201033643 χ : relative brightness 値 exceeds 1.2, 1.3 or less (1 1 The adhesion prevention is taken out by the Sony (share) LCD TV KDL-32V2500, and the film of the evaluation object is carried on the light diffusion plate, and the degree of occurrence of the highlight is observed and the degree of adhesion is observed as an evaluation of adhesion prevention. 〇: Even if observed from any angle, almost no bright spots are produced. φ △: When the film is observed from a slope, a bright spot is generated at one or more points. χ: When the film is viewed from the front, one or more bright spots are produced. (12) Thickness of each layer The sample was cut into triangles' fixed in the capsule and embedded in epoxy resin. Then, the embedded sample was cut into a thin film slice having a thickness of 50 nm in a longitudinal direction by a microtome (ULTRACUT-S), and then observed and photographed at an acceleration voltage of 1 〇〇kv using a transmission electron microscope. The photo was measured for the thickness of each layer to determine the average thickness. (13) Film thickness The film sample was measured for 10 points thickness by an electrical micrometer (K-402B manufactured by Anritsu), and the average 値 was used as the film thickness. (1 4) The enamel layer is formed by dropping 2 g of the UV curable resin into each film by a dropper, and thereafter carried at -17-201033643, the apex angle is 90°, the apex angle is 50 μm, and the 稜鏡 height is 25 μm. The forming plate is stretched with a UV curable resin in front of the film. Here, the UV light of 3 65 nm adjusted to 30 mJ/cm 2 was irradiated twice by the film side to sufficiently cure the UV curable resin. After the hardening, the enamel forming plate was peeled off from the film to form a sample with a ruthenium layer. As the UV curable resin, MCL555 C made of MicroSharp C has a refractive index of 1.55 to 1.58. After the 稜鏡 was formed, it was confirmed that the shape of the crucible was formed into a plate for forming a crucible on the cross-sectional SEM. As a reference sample for evaluation for improving the brightness effect, a polyethylene terephthalate film having a total light transmittance of 92%, a haze of 0.5%, and a film thickness of 75 μm without adding a tantalum was prepared, and the same was made as a prism. The mirror layer serves as a reference sample with a layer of enamel. (15) A diffusion bead layer was formed on the film, and a coating liquid having the composition shown below was applied by Mayer bar #14. Thereafter, it was dried in an oven at 100 ° C for 1 minute to sufficiently harden the resin. Thereafter, the film was aged at 60 ° C for 24 hours, and the film and the bead layer were further strongly adhered to each other to form a sample having a bead layer. As a reference sample for evaluation for improving the effect of brightness, a polyethylene terephthalate film having no total light transmittance of 92%, haze 0.5%, and film thickness of 75 μm was prepared, and diffusion was similarly performed. The bead layer ' becomes a reference sample with a diffused bead layer. Coating liquid: • "Yudaburu S-2740" manufactured by Nippon Shokubai Co., Ltd.: 201033643 • 128 parts by weight • "CORONET HL" manufactured by Japan Polyurethane Industry Co., Ltd.: 18 parts by weight • Methyl ethyl ketone: 105 parts by weight • Toluene: 1 〇 5 parts by weight • "MBX-20" manufactured by Sekisui Chemicals Co., Ltd. (acrylic particles with an average particle size of 20 μιη): 192 parts by weight (16) The effect of improving brightness by Sony LCD TV KDL-32V2500 takes out the backlight. The film is placed on the light diffusing plate, and the brightness is measured at the center of the screen (cd/m2) with the brightness meter MC-940 manufactured by Otsuka Electronics Co., Ltd. . The brightness improvement rate was calculated by the following formula, and the effect of improving brightness was evaluated. Brightness improvement rate (%) = Brightness (a) / Reference sample brightness (b) XI 00 ◎: Brightness up rate is over 120% ❿ 〇: Brightness up rate is over 1 1 0 %, 1 2 0 % or less △: Brightness The upward rate is more than 100%, and 110% or less X: the luminance up rate is loo%. The layer of the first embodiment is configured as a adhesion preventing layer/light diffusion layer/adhesion preventing layer. A bulk cerium oxide having an average particle diameter of 1·7 μm was added to the composition of the polyethylene terephthalate to be 0.08% by weight, and a composition for the adhesion preventing layer was prepared. On the other hand, a true spherical material having an average particle diameter of 2. Ομιη is added to isophthalic-19-201033643 acid (hereinafter referred to as "ΙΑ") 12 mol% copolymerized copolymerized polyparaphenylene The composition for the light diffusion layer was prepared to 2% by weight in ethylene glycol dicarboxylate. Each of the compositions is melted to form a laminate of the adhesion preventing layer/light diffusion layer/adhesion prevention layer, and is extruded from a plastic film and then rapidly cooled on a casting roll to obtain a laminated sheet. Thereafter, it was preheated at 75 ° C, extended to 3.3 times in the longitudinal direction at the extension temperature U 〇 ° C, and preheated at 11 (the TC was extended to 3.6 times in the transverse direction at an extension temperature of 130 ° C. Thereafter, The heat treatment was carried out at 23 ° C in the crystallization zone to obtain a laminated film, and when heat treatment was performed, the heat shrinkage ratio was adjusted by 1.5% in the longitudinal direction and 2.0% in the transverse direction, and the evaluation results are shown in Table 1. Example 2 A laminate film was obtained in the same manner as in Example 1 except that the composition for the adhesion prevention layer and the composition for the light diffusion layer were changed to those shown in Table 1. Example 3 Composition for the adhesion prevention layer The composition for the object and the light-diffusing layer was changed to the two layers (the adhesion preventing layer/light-diffusion layer), and the laminate film was obtained in the same manner as in Example 1. Comparative Example 1 A film was formed in the same manner as in Example 1 except that the adhesion preventing layer was not provided. The film was not adhered, and therefore, the void of the light diffusion layer was to be removed, and sufficient heat treatment (23 5 ° C) was performed. Will cause the film to rupture without the -20-201033643 method of film formation, so will When the heat treatment is insufficient, a large amount of voids are formed in the light-diffusing layer, and the film is deteriorated in total light transmittance. Comparative Example 2 In addition to the adhesion prevention layer, no material is added. The film was formed in the same manner as in Example 1 to obtain a laminated film. Since the adhesion preventing layer was not added with a coating material, the thickness of the surface φ was insufficient when assembled in the backlight unit, and it was adhered to other optical films. In the case of the coating of the adhesion preventing layer, the bulk cerium oxide having a small specific surface area was used in the same manner as in Example 1, and the film was obtained by the film formation. The laminated film has a large number of voids around the coating of the adhesion preventing layer because the material does not disintegrate. Therefore, the total light transmittance is deteriorated, and it is not suitable for use as an optical film. -21 - 201033643 m η
實施例1 實施例2 實施例3 比較例1 比較例2 比較例3 密 著 防 止 層 塡料之種類 讎 二氧化矽 雛 二氧化矽 ΜτΙλ 二氧化矽 - - 讎 二氧化矽 塡料之平均粒徑 μιη 1.7 2.3 8 . _ 1.7 塡料表面積 (BET比表面積） m2/g 300 400 700 - - 150 撕之添加量 wt% 0.08 0.1 8 _ _ 15 聚酯的種類 PET PET PET PET PET 聚酯的熔點 °C 254 267 254 _ 254 254 層之厚度 μιη 38 38 100 38 38 空隙的有無 〇 〇 〇 _ 〇 X 表面酿 nm 2500 3500 5000 3000 150 10000 光 擴 散 層 塡料的種類 真球狀 二氧化矽 真球狀 二氧化矽 真球狀 二氧化矽 真球狀 二氧化矽 真球狀 二氧化矽 真球狀 二氧化矽 塡料的平均粒徑 μιη 2 3 1 2 2 2 觀的縱橫比 1 1 1 1 1 1 觀的添加量 wt% 2 5 8 2 2 2 塡料的折射率 1.45 1.45 1.45 1.45 1.45 1.45 光擴散層之折射率 1.60 1.60 1.60 1.60 1.60 1.60 折射率差X塡料徑 μιη 0.3 0.45 0.15 0.3 0.3 0.3 聚酯的種類 IA12 PET IA8 PET IA20 PET IA12 PET IA12 PET IA12 PET 聚酯的熔點 °c 226 231 209 226 226 226 層之厚度 μιη 150 150 250 188 150 150 空隙的有無 〇 〇 〇 X 〇 〇 層 合 薄 膜 層構成 A/B/A A/B/A A/B B A/B/A A/B/A 密著防止層與光擴散層 之聚酯的熔點差 °c 28 36 45 - 28 28 齡薄膜之熱處理溫度 °c 235 240 218 220 235 235 層合薄膜總厚度 μιη 188 188 350 188 188 188 評 估 結 果 全光線透過率 % 95 90 80 50 95 40 霧値 % 90 95 85 90 90 90 光擴散率 % 80 85 80 60 80 80 亮度斑 〇 〇 〇 〇 X 〇 密著防止性 〇 〇 〇 〇 X 〇 設有稜鏡層時的亮度提高效果 ◎ 〇 〇 X 〇 X 設有珠子層時的亮度提高效果 〇 ◎ Δ X 〇 X 201033643Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Type of adhesion preventing layer 雠 雠 矽 矽 二 二 矽Μ Ι 二 二 二 二 - - - - - - 平均 平均 平均Ιηη 1.7 2.3 8 . _ 1.7 Dipper surface area (BET specific surface area) m2/g 300 400 700 - - 150 Tear addition amount wt% 0.08 0.1 8 _ _ 15 Type of polyester PET PET PET PET PET Melting point of polyester ° C 254 267 254 _ 254 254 Thickness of layer μιη 38 38 100 38 38 The presence or absence of voids 〇〇〇 〇X Surface brewing nm 2500 3500 5000 3000 150 10000 Type of light diffusing layer material True spherical cerium oxide true spherical Cerium oxide true spherical cerium oxide true spherical cerium oxide true spherical cerium oxide true spherical cerium oxide average particle size μιη 2 3 1 2 2 2 aspect ratio 1 1 1 1 1 1 Addition amount wt% 2 5 8 2 2 2 Refractive index of the material 1.45 1.45 1.45 1.45 1.45 1.45 Refractive index of the light diffusion layer 1.60 1.60 1.60 1.60 1.60 1.60 Refractive index difference X 塡 material diameter μιη 0.3 0.45 0.15 0.3 0.3 0.3 Type of ester IA12 PET IA8 PET IA20 PET IA12 PET IA12 PET IA12 PET Melting point of polyester °c 226 231 209 226 226 226 Thickness of layer μιη 150 150 250 188 150 150 The presence or absence of voids X 〇〇 laminated film layer constitutes A/B/AA/ B/AA/BBA/B/AA/B/A Melting point difference between polyester with adhesion preventing layer and light diffusing layer °c 28 36 45 - 28 Heat treatment temperature of 28-year old film °c 235 240 218 220 235 235 Lamination Total film thickness μιη 188 188 350 188 188 188 Evaluation results Total light transmittance % 95 90 80 50 95 40 Haze % 90 95 85 90 90 90 Light diffusivity % 80 85 80 60 80 80 Brightness X 〇 The adhesion prevention 〇〇〇〇X 〇The brightness enhancement effect when the enamel layer is provided ◎ 〇〇X 〇X The brightness improvement effect when the bead layer is provided 〇◎ Δ X 〇X 201033643
. 表中，「PET」表示聚對苯二甲酸乙二醇酯，「PEN 」表示聚乙烯2,6-萘二羧酸酯，「IA12PET」表示將異鄰 苯二甲酸12莫耳％經共聚合的共聚合聚對苯二甲酸乙二醇 酯，「IA8PET」表示將異鄰苯二甲酸8莫耳％經共聚合的 共聚合聚對苯二甲酸乙二醇酯，「IA20PET」表示將異鄰 苯二甲酸20莫耳％經共聚合之共聚合聚對苯二甲酸乙二醇 酯。層構成的欄之「A」表示密著防止層，「B」表示光擴 ^ 散層。 〔產業上可利用性〕 . 本發明的光學用層合薄膜可作爲液晶顯示裝置之光學 - 構件的基質薄膜而使用。In the table, "PET" means polyethylene terephthalate, "PEN" means polyethylene 2,6-naphthalenedicarboxylate, and "IA12PET" means 12% by weight of isophthalic acid. Polymerized copolymerized polyethylene terephthalate, "IA8PET" means copolymerized polyethylene terephthalate copolymerized with 8 mol% of isophthalic acid, "IA20PET" means different 20 mole % of phthalic acid copolymerized copolymerized polyethylene terephthalate. "A" in the column of the layer indicates the adhesion prevention layer, and "B" indicates the optical diffusion layer. [Industrial Applicability] The optical laminated film of the present invention can be used as a matrix film of an optical member of a liquid crystal display device.