TWI806674B - Polyester films and hard-coated films for displays - Google Patents

Polyester films and hard-coated films for displays Download PDF

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TWI806674B
TWI806674B TW111123383A TW111123383A TWI806674B TW I806674 B TWI806674 B TW I806674B TW 111123383 A TW111123383 A TW 111123383A TW 111123383 A TW111123383 A TW 111123383A TW I806674 B TWI806674 B TW I806674B
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film
polyester
hard
polyester film
display
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TW202242011A (en
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西尾正太郎
吉野賢二
本鄉有記
西尾明子
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日商東洋紡股份有限公司
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    • C—CHEMISTRY; METALLURGY
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    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J7/00—Chemical treatment or coating of shaped articles made of macromolecular substances
    • C08J7/04—Coating
    • C08J7/043—Improving the adhesiveness of the coatings per se, e.g. forming primers
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
    • C08J5/18—Manufacture of films or sheets
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J7/00—Chemical treatment or coating of shaped articles made of macromolecular substances
    • C08J7/04—Coating
    • C08J7/046—Forming abrasion-resistant coatings; Forming surface-hardening coatings
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
    • G02B1/10—Optical coatings produced by application to, or surface treatment of, optical elements
    • G02B1/14—Protective coatings, e.g. hard coatings
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/30—Polarising elements
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09F—DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
    • G09F9/00—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements

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Abstract

本發明提供一種量產性優異、反覆彎折後於折疊部分所顯示的影像沒有產生紊亂之虞的折疊式顯示器；及搭載有此類折疊式顯示器的攜帶式終端機器；還提供一種前述所用之表面保護薄膜用聚酯薄膜和表面保護薄膜用硬塗薄膜。 折疊式顯示器之表面保護薄膜用聚酯薄膜係一種厚度10～75μm之聚酯薄膜，其特徵為，長邊方向及寬度方向之至少其一方向的折射率為1.57～1.64。又，提供採用該折疊式顯示器之表面保護薄膜用聚酯薄膜的硬塗薄膜、折疊式顯示器及攜帶式終端機器。 The present invention provides a foldable display which is excellent in mass production and does not disturb the image displayed on the folded part after repeated bending; and a portable terminal equipped with such a foldable display; Polyester film for surface protection film and hard coat film for surface protection film. The polyester film for the surface protection film of the foldable display is a polyester film with a thickness of 10-75 μm, characterized in that the refractive index in at least one of the longitudinal direction and the width direction is 1.57-1.64. Also, a hard coat film using the polyester film for a surface protection film of a foldable display, a foldable display, and a portable terminal device are provided.

Description

顯示器用聚酯薄膜及硬塗薄膜Polyester films and hard-coated films for displays

本發明係關於折疊式顯示器之表面保護薄膜用聚酯薄膜、折疊式顯示器之表面保護薄膜用硬塗薄膜、折疊式顯示器、及攜帶式終端機器，並且係關於即便反覆折疊，也難以引起位於表面之薄膜的變形所導致之影像紊亂的折疊式顯示器及攜帶式終端機器、及該折疊式顯示器之表面保護薄膜用聚酯薄膜及硬塗薄膜。The present invention relates to a polyester film for a surface protection film of a foldable display, a hard coat film for a surface protection film of a foldable display, a foldable display, and a portable terminal device. Foldable displays and portable terminal devices that cause image disturbance due to deformation of the film, and polyester films and hard-coated films for surface protection films of the foldable displays.

隨著攜帶式終端機器的薄膜輕量化之發展，智慧型手機所代表的攜帶式終端機器廣為普及。在對於攜帶式終端機器要求各種機能的同時，也被要求便利性。依此，普及中之攜帶式終端機器係要單手即可簡單操作，甚至前提是要收放在衣服的口袋等，因而必須作成6英吋左右的小畫面尺寸。With the development of lightweight thin films for portable terminal devices, portable terminal devices such as smartphones are widely used. While various functions are required for portable terminals, convenience is also required. Accordingly, popularized portable terminal devices can be easily operated with one hand, even if they are stored in a pocket of clothes, etc., so they must be made with a small screen size of about 6 inches.

另一方面，對於7英吋～10英吋畫面大小的平板終端而言，不僅僅是影像內容、音樂，還預想了商業用途、繪圖用途、閱讀等而具有高機能性。然而，無法單手操作，攜帶性也不佳，在便利性方面也有問題。On the other hand, a tablet terminal with a screen size of 7 inches to 10 inches has high functionality because not only video content and music but also business use, drawing use, reading, etc. are expected. However, it cannot be operated with one hand, and the portability is not good, so there is also a problem in terms of convenience.

為了要達成這些，有提案如專利文獻1之結合複數個顯示器來加以小型化的手法(參照專利文獻1)，但因留有邊框(bezel)的部分，會造成影像被切掉，因而視認性的降低變成問題而未普及。In order to achieve these, there are proposals such as patent document 1 combining a plurality of displays for miniaturization (refer to patent document 1), but because the part of the bezel is left, the image will be cut off, so the visibility The reduction of the technology has become a problem and has not been popularized.

於是，近年來，有提案整合可撓性顯示器、折疊式顯示器的攜帶式終端。如為此方式，則影像不會中斷，可作成為搭載有大畫面顯示器的攜帶式終端機器而便利性良好地攜帶著。Therefore, in recent years, portable terminals integrating flexible displays and foldable displays have been proposed. In this way, the video is not interrupted, and it can be conveniently carried as a portable terminal device equipped with a large-screen display.

於此，關於習知之不具有折疊構造之顯示器和攜帶式終端機器而言，其顯示器表面係可利用玻璃等不具有可撓性的材料來加以保護，但是就折疊式顯示器而言，在連著折疊部分而成為一整面顯示器的情形下，必須使用具有可撓性且可保護表面的硬塗薄膜等。然而，折疊式顯示器中，對應於折疊部分的特定之處會反覆彎折，所以會有該處的薄膜經時性地變形、顯示器所顯示之影像歪曲等的問題。Here, for the known display and portable terminal without folding structure, the display surface can be protected by non-flexible materials such as glass, but as far as the folding display is concerned, the In the case of folding parts to form a full-screen display, it is necessary to use a flexible hard-coated film that can protect the surface. However, in a foldable display, a specific portion corresponding to the folded portion is repeatedly bent, so there are problems such as deformation of the film at the portion over time, distortion of an image displayed on the display, and the like.

於是，也有提案局部改變膜厚的手法(參照專利文獻2)，但會有量產性不佳的問題。 [先前技術文獻] [專利文獻] Therefore, a method of locally changing the film thickness is also proposed (see Patent Document 2), but there is a problem that mass productivity is not good. [Prior Art Literature] [Patent Document]

專利文獻1　日本特開2010-228391號公報 專利文獻2　日本特開2016-155124號公報 Patent Document 1 Japanese Patent Laid-Open No. 2010-228391 Patent Document 2 Japanese Patent Laid-Open No. 2016-155124

[發明欲解決之課題][Problem to be solved by the invention]

本發明係想要解決如上所述之習知顯示器之表面保護構件所具有的問題的發明，為了可以提供量產性優異，且反覆彎折後沒有於折疊部分所顯示之影像上產生紊亂之虞的折疊式顯示器、及搭載有此類折疊式顯示器之攜帶式終端機器，而提供一種折疊式顯示器之表面保護薄膜用聚酯薄膜和表面保護薄膜用硬塗薄膜。 [用以解決課題之手段] The present invention is an invention intended to solve the problems of the surface protection member of the conventional display as described above, in order to provide excellent mass productivity and avoid the risk of disorder on the image displayed on the folded part after repeated bending A foldable display and a portable terminal equipped with such a foldable display provide a polyester film for a surface protection film of a foldable display and a hard-coated film for a surface protection film. [Means to solve the problem]

亦即，本發明具有如下構成。 1.一種折疊式顯示器之表面保護薄膜用聚酯薄膜，係厚度10～75μm之聚酯薄膜，其特徵為，長邊方向及寬度方向之至少其一方向的折射率為1.57～1.64。2.如上述1.之折疊式顯示器之表面保護薄膜用聚酯薄膜，其中，彎曲方向之折射率為1.57～1.64(此處的彎曲方向係指折疊聚酯薄膜時之與折疊部正交的方向)。3.如上述2.之折疊式顯示器之表面保護薄膜用聚酯薄膜，其中，彎曲方向係對應於聚酯薄膜之長邊方向。4.一種折疊式顯示器之表面保護薄膜用硬塗薄膜，其特徵為，在如上述1.至3.中之任一折疊式顯示器之表面保護薄膜用聚酯薄膜的至少單面上，具有厚度1～40μm之硬塗層。5.如上述4.之折疊式顯示器之表面保護薄膜用硬塗薄膜，其中，依據JIS K5600-5-4：1999之以750g負重所測定之硬塗層的鉛筆硬度為H以上。6.一種折疊式顯示器，其係以使硬塗層位於表面的方式，將如上述4.或5.之折疊式顯示器之表面保護薄膜用硬塗薄膜當作為表面保護薄膜來進行配置的折疊式顯示器，其特徵為，折疊時之彎曲半徑為5mm以下。7.如上述6.之折疊式顯示器，其中，連著折疊式顯示器之折疊部分，配設有連續的單一硬塗薄膜。8.一種攜帶式終端機器，其係具有如上述6.或7.之折疊式顯示器。9.一種折疊式顯示器之表面保護薄膜用聚酯薄膜的製造方法，其係厚度10～75μm之聚酯薄膜的製造方法，其特徵為，包含：將未延伸聚酯片在長邊方向及寬度方向之至少其一方向上予以延伸至延伸倍率1.0～3.0倍的步驟。10.如上述9.之折疊式顯示器之表面保護薄膜用聚酯薄膜的製造方法，其中，彎曲方向之延伸倍率為1.0～3.0倍(此處的彎曲方向係指折疊聚酯薄膜時之與折疊部正交的方向)。11.如上述10.之折疊式顯示器之表面保護薄膜用聚酯薄膜的製造方法，其中，彎曲方向係對應於未延伸聚酯片之長邊方向。 [發明之效果] That is, the present invention has the following constitutions. 1. A polyester film for a surface protection film of a foldable display, which is a polyester film with a thickness of 10-75 μm, characterized in that the refractive index of at least one of the long-side direction and the width direction is 1.57-1.64. 2. The polyester film for a surface protection film for a foldable display as described in 1. above, wherein the refractive index in the bending direction is 1.57 to 1.64 (the bending direction here refers to the direction perpendicular to the folded portion when the polyester film is folded) . 3. The polyester film for a surface protection film for a foldable display according to the above 2., wherein the bending direction corresponds to the long side direction of the polyester film. 4. A hard-coated film for a surface protection film of a foldable display, characterized in that, on at least one side of the polyester film for a surface protection film of a foldable display in any one of the above 1. to 3. 1~40μm hard coating. 5. The hard coat film for a surface protection film of a foldable display according to the above 4, wherein the pencil hardness of the hard coat layer measured with a load of 750 g according to JIS K5600-5-4:1999 is H or higher. 6. A foldable display, which is a foldable display in which a hard coat layer is located on the surface, and the hard coat film for the surface protection film of the foldable display as described in 4. or 5. above is arranged as a surface protection film. The display is characterized in that the bending radius when folded is 5mm or less. 7. The foldable display according to the above 6., wherein a continuous single hard-coated film is disposed along the folded portion of the foldable display. 8. A portable terminal device having a foldable display as described in 6. or 7. above. 9. A method for producing a polyester film for a surface protection film of a foldable display, which is a method for producing a polyester film with a thickness of 10-75 μm, characterized in that it comprises: forming an unstretched polyester sheet in the direction of the long side and the width At least one of the directions is extended to a step of 1.0 to 3.0 times the extension ratio. 10. The method for producing a polyester film for a surface protection film of a foldable display as in the above 9., wherein the stretching ratio in the bending direction is 1.0 to 3.0 times (the bending direction here refers to the difference between folding and folding of the polyester film). in the orthogonal direction). 11. The method for producing a polyester film for a surface protection film of a foldable display according to 10. above, wherein the bending direction corresponds to the long side direction of the unstretched polyester sheet. [Effect of Invention]

使用本發明之折疊式顯示器之表面保護薄膜用聚酯薄膜和硬塗薄膜的折疊式顯示器係在維持量產性的同時，其聚酯薄膜和硬塗薄膜因為在反覆折疊之後不會引起變形，所以是不會在顯示器之折疊部分產生影像紊亂者。搭載有此類折疊式顯示器之攜帶式終端機器係可提供美麗的影像、機能性豐富、攜帶性等之便利性優異者。The foldable display using the polyester film and hard-coated film for the surface protection film of the foldable display of the present invention maintains mass productivity, and since the polyester film and the hard-coated film do not cause deformation after repeated folding, Therefore, there will be no image disorder in the folded part of the display. A portable terminal equipped with such a foldable display can provide beautiful images, rich in functionality, and excellent in convenience such as portability.

[用以實施發明的形態][Mode for Carrying Out the Invention]

(顯示器) 本發明之所謂的顯示器係指所有顯示裝置，作為顯示器的種類，係有LCD、有機EL顯示器、無機EL顯示器、LED、FED等，較佳為具有可彎折構造之LCD、有機EL、無機EL。尤其是以可減少層構成之有機EL、無機EL為特佳，更佳的是色域寬廣的有機EL。 (monitor) The so-called display in the present invention refers to all display devices. As the type of display, there are LCD, organic EL display, inorganic EL display, LED, FED, etc., preferably LCD with bendable structure, organic EL, inorganic EL . In particular, organic EL and inorganic EL that can reduce the layer configuration are particularly preferable, and organic EL that has a wide color gamut is more preferable.

(折疊式顯示器) 較佳的折疊式顯示器係連續的一片顯示器在攜帶時可以折成2個，使大小減半，成為使攜帶性提升的構造。又，同時還以薄型、輕量化者為佳。因此，折疊式顯示器之彎曲半徑宜為5mm以下，更佳為3mm以下。若彎曲半徑為5mm以下，則折疊狀態的薄型化是可能的。可說是彎曲半徑越小越好，但可為0.1mm以上，也可為0.5mm以上。即便是1mm以上，對比於不具有折疊構造之習知的顯示器，實用性亦十分良好。所謂的折疊時之彎曲半徑係意指測定圖1之示意圖之元件符號11的地方，折疊時之折疊部分的內側半徑。另外，後述之表面保護薄膜係可位於折疊式顯示器之折疊外側，也可位於內側。 (foldable display) A preferred foldable display is a continuous display that can be folded into two when being carried, reducing the size by half and improving portability. Also, at the same time, it is preferable to be thin and lightweight. Therefore, the bending radius of the foldable display is preferably less than 5 mm, more preferably less than 3 mm. When the bending radius is 5 mm or less, it is possible to reduce the thickness of the folded state. It can be said that the smaller the bending radius, the better, but it may be 0.1 mm or more, or 0.5 mm or more. Even if it is more than 1mm, compared with the conventional display without folding structure, the practicability is very good. The so-called bending radius at the time of folding means the inner radius of the folded part at the time of folding at the place where the symbol 11 of the schematic diagram in FIG. 1 is measured. In addition, the surface protection film described later may be located on the outside or inside of the foldable display.

(有機EL) 有機EL顯示器之一般性構成係包括：由電極/電子輸送層/發光層/電洞輸送層/透明電極所構成之有機EL層、提升畫質用的相位差板、偏光板。 (Organic EL) The general composition of an organic EL display includes: an organic EL layer composed of an electrode/electron transport layer/luminescent layer/hole transport layer/transparent electrode, a phase difference plate for improving image quality, and a polarizing plate.

(具有觸控面板之攜帶式終端機器) 在於具有觸控面板之攜帶式終端機器上採用有機EL顯示器的情形下，會於有機EL顯示器的上部或有機EL層/相位差板之間配置觸控面板模組。此時，當從上部施加衝擊時，因為會有有機EL、觸控面板之電路斷線之虞，故而表面保護薄膜是必要的，而作為表面保護薄膜而配置在顯示器前面的薄膜，較佳的是在顯示器的至少表面側上積層有硬塗層者。 (portable terminal with touch panel) In the case of using an organic EL display on a portable terminal device with a touch panel, a touch panel module is arranged on the top of the organic EL display or between the organic EL layer/retardation plate. At this time, when an impact is applied from above, the organic EL and the circuit of the touch panel may be disconnected, so a surface protection film is necessary, and a film arranged in front of the display as a surface protection film is preferable. A hard coat layer is laminated on at least the surface side of the display.

(折疊式顯示器之表面保護薄膜) 作為表面保護薄膜，如果是聚醯亞胺薄膜、聚酯薄膜、聚碳酸酯薄膜、丙烯酸薄膜、三乙醯基纖維素薄膜、環烯烴聚合物薄膜等光線穿透性高、霧值(haze)低之薄膜的話，則可以使用，但其中，較佳的是耐衝擊性高、具有充分鉛筆硬度的聚醯亞胺薄膜、聚酯薄膜，特佳的是可便宜製造的聚酯薄膜。 (Surface protection film for foldable displays) As a surface protection film, if it is polyimide film, polyester film, polycarbonate film, acrylic film, triacetyl cellulose film, cycloolefin polymer film, etc. A lower film can be used, but among them, a polyimide film and a polyester film having high impact resistance and sufficient pencil hardness are preferable, and a polyester film which can be produced at low cost is particularly preferable.

在本發明中，聚酯薄膜係可為包括一種以上之聚酯樹脂之單層構成的薄膜，而於使用2種以上之聚酯時，可為多層構造薄膜，也可為反覆構造之超多層積層薄膜。In the present invention, the polyester film may be a single-layer film comprising more than one polyester resin, and when two or more polyester resins are used, it may be a multi-layer film or a super-multi-layer structure with repeated structures. laminated film.

作為聚酯薄膜所使用之聚酯樹脂，例如可列舉出包括聚對苯二甲酸乙二酯、聚對苯二甲酸丁二酯、聚乙烯-2,6-萘二甲酸酯、或以該等樹脂之構成成分為主成分之共聚物的聚酯薄膜。其中，就力學性質、耐熱性、透明性、價格的觀點來說，特佳的是經延伸過之聚對苯二甲酸乙二酯薄膜。As the polyester resin used for the polyester film, for example, polyethylene terephthalate, polybutylene terephthalate, polyethylene-2,6-naphthalene dicarboxylate, or the A polyester film made of a copolymer whose main component is a resin. Among them, stretched polyethylene terephthalate film is particularly preferable in terms of mechanical properties, heat resistance, transparency, and price.

在聚酯薄膜上使用聚酯之共聚物時，作為聚酯之二羧酸成分，例如可列舉出：己二酸、癸二酸等脂肪族二羧酸；對苯二甲酸、間苯二甲酸、鄰苯二甲酸、2,6-萘二甲酸等芳香族二羧酸；1,2,4-苯三甲酸、1,2,4,5-苯四甲酸等多官能羧酸。又，作為甘醇成分，例如可列舉出：乙二醇、二乙二醇、1,4-丁二醇、丙二醇、新戊二醇等脂肪酸甘醇；對二甲苯二醇等芳香族甘醇；1,4-環己烷二甲醇等脂環族甘醇；平均分子量為150～20,000之聚乙二醇。較佳的共聚物之共聚成分的質量比例為小於20質量%。於小於20質量%時，可保持薄膜強度、透明性、耐熱性，故佳。When a polyester copolymer is used for the polyester film, examples of the dicarboxylic acid component of the polyester include aliphatic dicarboxylic acids such as adipic acid and sebacic acid; terephthalic acid and isophthalic acid , phthalic acid, 2,6-naphthalene dicarboxylic acid and other aromatic dicarboxylic acids; 1,2,4-benzenetricarboxylic acid, 1,2,4,5-benzenetetracarboxylic acid and other multifunctional carboxylic acids. In addition, examples of the glycol component include fatty acid glycols such as ethylene glycol, diethylene glycol, 1,4-butanediol, propylene glycol, and neopentyl glycol; and aromatic glycols such as p-xylylene glycol. ; 1,4-cyclohexanedimethanol and other alicyclic glycols; polyethylene glycol with an average molecular weight of 150-20,000. The mass ratio of the copolymerization component of a preferable copolymer is less than 20 mass %. When it is less than 20% by mass, film strength, transparency, and heat resistance can be maintained, which is preferable.

又，在聚酯薄膜之製造時，至少一種以上之樹脂顆粒的極限黏度宜為0.50～1.0dl/g之範圍。當極限黏度為0.50dl/g以上時，所得薄膜的耐衝擊性會提升，因外部衝擊所導致之顯示器內部電路的斷線難以發生，故佳。另一方面，當極限黏度為1.00dl/g以下時，熔融流體之過濾壓力的上升不會變得過大，易於穩定地操作薄膜製造，故佳。In addition, when producing a polyester film, the intrinsic viscosity of at least one or more resin particles is preferably in the range of 0.50 to 1.0 dl/g. When the limit viscosity is 0.50dl/g or more, the impact resistance of the obtained film will be improved, and the disconnection of the internal circuit of the display due to external impact will hardly occur, so it is preferable. On the other hand, when the intrinsic viscosity is 1.00 dl/g or less, the increase in filtration pressure of molten fluid does not become too large, and it is easy to operate stable film production, which is preferable.

聚酯薄膜的厚度係以10～75μm為佳，更佳為25～75μm。當厚度為10μm以上時，可見到鉛筆硬度提升效果，而當厚度為75μm以下時，除了有利於輕量化之外，可撓性、加工性和處理性等優異。The thickness of the polyester film is preferably 10-75 μm, more preferably 25-75 μm. When the thickness is 10 μm or more, an effect of improving pencil hardness can be seen, while when the thickness is 75 μm or less, it is not only advantageous for weight reduction, but also excellent in flexibility, processability, and handleability.

本發明之聚酯薄膜的表面係可為平滑，也可具有凹凸，而基於可使用於顯示器之表面覆蓋用途上的觀點，不佳的是源自凹凸之光學特性降低。霧值宜為3%以下，更佳為2%以下，最佳為1%以下。若霧值為3%以下，則可使影像之視認性提升。霧值的下限越小越好，但可為0.1%以上，也可為0.3%以上。The surface of the polyester film of the present invention may be smooth or may have irregularities, but from the viewpoint of being usable for a surface covering of a display, it is disadvantageous that the optical properties due to the irregularities are lowered. The fog value should be less than 3%, more preferably less than 2%, most preferably less than 1%. If the fog value is less than 3%, the visibility of the image can be improved. The lower limit of the haze value is preferably as small as possible, but it may be 0.1% or more, or 0.3% or more.

如上所述，基於使霧值降低之目的來說，比較好的是薄膜表面之凹凸不大，但是基於處理性的觀點，為了要賦予適度平滑性，則作為形成凹凸的方法，係可摻配填料在表層之聚酯樹脂層中，或者是於製膜中塗布含有填料之塗布層來加以形成。As mentioned above, for the purpose of reducing the haze value, it is better that the unevenness on the surface of the film is not large, but from the viewpoint of handleability, in order to impart appropriate smoothness, as a method of forming unevenness, it is possible to blend The filler is formed in the polyester resin layer of the surface layer, or by coating a coating layer containing the filler in film formation.

作為摻配粒子於基材薄膜的方法，可採用公知方法。例如，可在製造聚酯之任意階段時進行添加，但宜為在酯化階段、或酯交換反應結束之後、聚縮合反應開始之前的階段，以已分散在乙二醇等中之漿料形態添加，而繼續進行聚縮合反應。又，可根據：使用附有通風孔的混練壓出機，將分散於乙二醇或水等之粒子的漿料與聚酯原料混合的方法；或使用混練壓出機，將已乾燥之粒子與聚酯原料混合的方法等而進行。As a method of blending the particles into the base film, a known method can be used. For example, it can be added at any stage of polyester production, but it is preferably in the form of a slurry dispersed in ethylene glycol or the like at the stage of esterification, or after the end of the transesterification reaction, and before the start of the polycondensation reaction. Added to continue the polycondensation reaction. In addition, it can be based on: using a kneading extruder with ventilation holes to mix the slurry of particles dispersed in ethylene glycol or water with polyester raw materials; or using a kneading extruder to mix the dried particles It is carried out by a method such as mixing with polyester raw materials.

其中，較佳的是：在使凝集體無機粒子均質分散於屬於聚酯原料之一部分的單體液中之後，將經過濾者添加至酯化反應前、酯化反應中或酯化反應後之聚酯原料的剩餘部分中之方法。當依據此方法時，因為單體液為低黏度，所以可輕易施行粒子之均質分散和漿料的高精度過濾，同時在添加至原料的剩餘部分時，粒子之分散性良好，不易產生新的凝集體。基於此觀點，特佳的是添加至酯化反應前之低溫狀態的原料剩餘部分。Among them, it is preferable that after the aggregated inorganic particles are homogeneously dispersed in the monomer liquid which is a part of the polyester raw material, the filtered one is added to the esterification reaction before, during the esterification reaction or after the esterification reaction. Process in the remainder of the polyester raw material. When following this method, because the monomer liquid is of low viscosity, it is easy to perform homogeneous dispersion of particles and high-precision filtration of slurry. At the same time, when it is added to the rest of the raw material, the dispersion of the particles is good, and it is difficult to generate new particles. agglomerates. From this point of view, it is particularly preferable to add to the remainder of the raw material in a low-temperature state before the esterification reaction.

又，在得到預先含有粒子之聚酯之後，藉由將該顆粒與不含有粒子之顆粒予以混練壓出等的方法(母料補充法)，可進一步減少薄膜表面之突起數。Also, after the polyester containing particles is obtained, the number of protrusions on the surface of the film can be further reduced by kneading and extruding the particles with particles not containing particles (masterbatch replenishment method).

又，聚酯薄膜係在可將總光線穿透率維持於較佳範圍的範圍內，可含有各種添加劑。作為添加劑，例如可列舉出抗靜電劑、UV吸收劑、安定劑。In addition, the polyester film may contain various additives within a range in which the total light transmittance can be maintained in a preferable range. As an additive, an antistatic agent, a UV absorber, and a stabilizer are mentioned, for example.

聚酯薄膜之總光線穿透率係以85%以上為佳，以87%以上更佳。如為85%以上之穿透率，則可充分確保視認性。雖說聚酯薄膜之總光線穿透率越高越好，但可為99%以下，也可為97%以下。The total light transmittance of the polyester film is preferably above 85%, more preferably above 87%. If the penetration rate is more than 85%, the visibility can be fully ensured. Although the higher the total light transmittance of the polyester film, the better, but it can be less than 99%, or less than 97%.

在本發明之聚酯薄膜表面上，可施行用來使與形成硬塗層等之樹脂的密接性提高之處理。The surface of the polyester film of the present invention may be treated to improve the adhesion with the resin forming the hard coat layer or the like.

作為表面處理之方法，例如可列舉出噴砂處理、溶劑處理等所致之凹凸化處理、和電暈放電處理、電子線照射處理、電漿處理、臭氧-紫外線照射處理、火焰處理、鉻酸處理、熱風處理等之氧化處理等，可無特別限制地使用。Surface treatment methods include, for example, roughening treatment by sandblasting, solvent treatment, etc., corona discharge treatment, electron beam irradiation treatment, plasma treatment, ozone-ultraviolet irradiation treatment, flame treatment, and chromic acid treatment. , oxidation treatment such as hot air treatment, etc., can be used without particular limitation.

又，也可透過易接著層等接著提升層來提高密接性。作為易接著層，可無特別限制地使用丙烯酸樹脂、聚酯樹脂、聚胺基甲酸酯樹脂、聚醚樹脂等，能藉由一般的塗布手法，較佳為所謂的模內塗布(in-line coating)手法來形成。In addition, the adhesiveness can also be improved by an adhesion-promoting layer such as an easy-adhesive layer. As the easy-to-adhesive layer, acrylic resin, polyester resin, polyurethane resin, polyether resin, etc. can be used without particular limitation, and can be applied by a general coating method, preferably so-called in-mold coating (in-mold coating). line coating) method to form.

上述聚酯薄膜係例如可經由如下步驟來加以製造：於屬於聚酯原料之一部分的單體液中使無機粒子均質分散並加以過濾之後，添加至聚酯原料的剩餘部分中，進行聚酯之聚合的聚合步驟；將該聚酯經由過濾器而熔融壓出成片狀，在將其冷卻之後，進行延伸，形成基材薄膜的薄膜形成步驟。The above-mentioned polyester film can be produced, for example, by dispersing and filtering inorganic particles homogeneously in a monomer liquid which is a part of the polyester raw material, adding it to the remaining part of the polyester raw material, and carrying out polyester A polymerization step of polymerization; a film forming step in which the polyester is melted and extruded into a sheet through a filter, cooled, and stretched to form a base film.

接著，關於雙軸延伸聚酯薄膜之製造方法，詳細說明將聚對苯二甲酸乙二酯(以下，記載為PET)之顆粒當作基材薄膜之原料的例子，但並非限定於此。又，可為單層構成、多層構成等，並未限定層數。Next, an example in which pellets of polyethylene terephthalate (hereinafter, referred to as PET) are used as a raw material of the base film will be described in detail about a method for producing a biaxially stretched polyester film, but the present invention is not limited thereto. Moreover, it may be a single-layer structure, a multi-layer structure, etc., and the number of layers is not limited.

於依既定比例將PET顆粒予以混合、乾燥之後，供給至公知的熔融積層用壓出機，從細縫狀模具壓出成片狀，使在澆鑄滾筒上進行冷卻固化，而形成未延伸薄膜。於單層的情形下，可採用一台壓出機，但於製造多層構成之薄膜的情形下，可採用2台以上壓出機，2層以上之歧管或合流區塊(例如，具有方型合流部之合流區塊)，將構成各最外表層之複數個薄膜層予以積層，從噴嘴壓出兩層以上的片，以澆鑄滾筒進行冷卻而形成未延伸薄膜。After the PET pellets are mixed and dried in a predetermined ratio, they are supplied to a known extruder for fusion lamination, extruded into a sheet form from a slit-shaped mold, and cooled and solidified on a casting drum to form an unstretched film. In the case of a single layer, one extruder can be used, but in the case of manufacturing a multi-layered film, more than two extruders can be used, and more than two layers of manifolds or confluence blocks (for example, with square The confluence block of the type confluence part), the plurality of film layers constituting each outermost layer are laminated, and more than two layers of sheets are extruded from the nozzle, cooled by the casting drum to form an unstretched film.

此時，在熔融壓出時，於熔融樹脂保持在約280℃左右的任意處，為了要去除樹脂中所含有之異物，以進行高精度過濾為佳。在熔融樹脂之高精度過濾中所採用之過濾材料，並未特別限定，但基於以Si、Ti、Sb、Ge、Cu為主要成分的凝集物及高熔點有機物的去除性能優異的觀點，較佳的是不鏽鋼燒結體之過濾材料。At this time, it is preferable to perform high-precision filtration in order to remove foreign matter contained in the resin at any place where the molten resin is kept at about 280°C during melt extrusion. The filter material used in the high-precision filtration of molten resin is not particularly limited, but based on the viewpoint of excellent removal performance of agglomerates and high-melting point organic substances mainly composed of Si, Ti, Sb, Ge, and Cu, it is preferred It is the filter material of stainless steel sintered body.

再者，過濾材料之過濾粒子尺寸(初期過濾效率95%)係以20μm以下為佳，特佳為15μm以下。當過濾材料之過濾粒子尺寸(初期過濾效率95%)超過20μm，會無法充分去除20μm以上大小之異物。藉由使用過濾材料之過濾粒子尺寸(初期過濾效率95%)為20μm以下之過濾材料來進行熔融樹脂之高精度過濾，雖然會有生產性降低的情形，但可得到因粗大粒子所造成之突起為較少的薄膜，故佳。Furthermore, the filter particle size of the filter material (initial filter efficiency 95%) is preferably below 20 μm, especially preferably below 15 μm. When the filter particle size of the filter material (initial filtration efficiency 95%) exceeds 20 μm, it will not be able to fully remove foreign matter larger than 20 μm. High-precision filtration of molten resin by using a filter material with a filter particle size (initial filtration efficiency of 95%) of 20 μm or less, although there may be a reduction in productivity, protrusions caused by coarse particles can be obtained It is better for less film.

在聚酯薄膜之長邊方向(機械流動方向)及寬度方向之至少其一方向的折射率係宜為1.57～1.64。然後，聚酯薄膜之彎曲方向的折射率係以1.57～1.64更佳。於此，所謂的彎曲方向係意指如圖2之聚酯薄膜(元件符號2)上之元件符號22所示，在折疊式顯示器之表面保護薄膜的用途上所設想之與折疊部(元件符號21)正交的方向。當長邊方向及寬度方向之至少其一方向的折射率為1.57～1.64時，反覆折疊時之變形少，不會有使折疊式顯示器之畫質降低之虞，故佳。折射率係以1.575～1.634更佳。當然，該方向係以上述彎曲方向為佳。聚酯薄膜之折射率係可透過調節延伸倍率而有效地調節。較佳的是將未延伸聚酯片長邊方向(機械流動方向)及寬度方向之至少其一方向的延伸倍率設為1.0～3.0倍，更佳為1.0～2.5倍。然後，該延伸方向係宜為上述彎曲方向。作為延伸溫度，較佳為80～140℃，更佳為90～130℃。另外，延伸時之加熱方法係可採用熱風加熱方式、滾筒加熱方式、紅外線加熱方式等習知之公知手段。藉由將延伸溫度設為80～140℃，則可以防止在上述延伸倍率下之延伸所造成的厚度不均。The refractive index in at least one of the longitudinal direction (machine flow direction) and the width direction of the polyester film is preferably 1.57 to 1.64. Then, the refractive index in the bending direction of the polyester film is more preferably 1.57-1.64. Here, the so-called bending direction means that as shown by the element symbol 22 on the polyester film (element symbol 2) of FIG. 21) Orthogonal directions. When the refractive index in at least one of the longitudinal direction and the width direction is 1.57 to 1.64, there is little deformation during repeated folding and there is no risk of lowering the image quality of the foldable display, which is preferable. The refractive index is more preferably 1.575-1.634. Of course, the direction is preferably the above-mentioned bending direction. The refractive index of the polyester film can be effectively adjusted by adjusting the stretching ratio. Preferably, the stretching ratio in at least one of the longitudinal direction (machine flow direction) and the width direction of the unstretched polyester sheet is 1.0 to 3.0 times, more preferably 1.0 to 2.5 times. Then, the extension direction is preferably the above-mentioned bending direction. As stretching temperature, it is preferable that it is 80-140 degreeC, and it is more preferable that it is 90-130 degreeC. In addition, the heating method at the time of stretching can adopt known means such as hot air heating method, drum heating method, infrared heating method and the like. By setting the stretching temperature at 80 to 140° C., thickness unevenness due to stretching at the above-mentioned stretching ratio can be prevented.

與彎曲方向正交之方向(折疊部之方向)的折射率係基於薄膜之力學特性而以大於彎曲方向為佳，作為與彎曲方向正交之方向的延伸倍率，可例示2.5～5.0倍，以大於彎曲方向之延伸倍率為佳。藉由將延伸倍率設為2.5倍以上，則可得到安定的生產性，藉由將延伸倍率設為5倍以下，則可得到良好的耐衝擊性。The refractive index in the direction perpendicular to the bending direction (the direction of the folded portion) is preferably greater than that in the bending direction based on the mechanical properties of the film. As the elongation ratio in the direction perpendicular to the bending direction, 2.5 to 5.0 times can be exemplified. The elongation ratio greater than the bending direction is better. Stable productivity can be obtained by making the stretching ratio 2.5 times or more, and favorable impact resistance can be obtained by making the stretching ratio 5 times or less.

又，聚酯薄膜之彎曲方向係宜對應到長邊方向(機械流動方向)。如此一來，可得到安定的生產性。亦即，可得到將未延伸聚酯片在長邊方向上以1.0～3.0倍，較佳為1.0～2.5倍之延伸倍率進行延伸為佳之聚酯薄膜。而且，於寬度方向上，以2.5～5.0倍之延伸倍率進行延伸者可說是較佳的態樣。Also, the bending direction of the polyester film should preferably correspond to the long side direction (machine flow direction). In this way, stable productivity can be obtained. That is, it is possible to obtain a polyester film in which an unstretched polyester sheet is preferably stretched at a stretch ratio of 1.0 to 3.0 times, preferably 1.0 to 2.5 times, in the longitudinal direction. Furthermore, stretching at a stretching ratio of 2.5 to 5.0 times in the width direction is a preferable aspect.

具體而言，例如，在將PET之顆粒予以充分真空乾燥之後，供給至壓出機，在約280℃下熔融壓出成片狀，使進行冷卻固化，形成未延伸PET片。利用加熱至80～120℃之滾筒，將所得到之未延伸片在長邊方向上延伸1.0～3.0倍，得到單軸配向PET薄膜。再者，利用夾子把持住薄膜之端部，導往已加熱成80～180℃之熱風區域，乾燥後，在寬度方向上延伸2.5～5.0倍。接下來，可以導往160～240℃之熱處理區域，進行1～60秒鐘的熱處理。於此熱處理步驟中，可以因應需要而在寬度方向或長邊方向上施以1～12%的鬆弛處理。Specifically, for example, after sufficiently vacuum-drying PET pellets, they are supplied to an extruder, melted and extruded into a sheet at about 280° C., cooled and solidified to form an unstretched PET sheet. Using a roller heated to 80-120°C, stretch the obtained unstretched sheet 1.0-3.0 times in the long side direction to obtain a uniaxially aligned PET film. Furthermore, use clips to hold the end of the film, guide it to a hot air area heated to 80-180°C, and stretch it 2.5-5.0 times in the width direction after drying. Next, it can be directed to a heat treatment zone at 160-240° C. for 1-60 seconds of heat treatment. In this heat treatment step, a relaxation treatment of 1-12% may be applied in the width direction or the longitudinal direction as required.

聚酯薄膜之極限黏度係以0.50～1.0dl/g之範圍為佳。當極限黏度為0.50dl/g以上，則耐衝擊性提升，不容易發生因外部衝擊所導致之顯示器內部電路之斷線，故佳。另一方面，當極限黏度為1.0dl/g以下，熔融流體之過濾壓力上升不會變得過大，薄膜製造安定，故佳。The intrinsic viscosity of the polyester film is preferably in the range of 0.50-1.0dl/g. When the limit viscosity is more than 0.50dl/g, the impact resistance is improved, and it is less likely to cause disconnection of the internal circuit of the display due to external impact, so it is preferable. On the other hand, when the limiting viscosity is 1.0 dl/g or less, the filtration pressure of molten fluid does not increase too much, and film production is stable, which is preferable.

(易接著層) 易接著層係將該塗布液塗布在未延伸或縱向單軸延伸薄膜之單面或兩面上之後，於100～150℃下乾燥，接著在橫向上延伸而獲得。最終的易接著層的塗布量係以管理在0.05～0.20g/m 2為佳。當塗布量小於0.05g/m 2時，會有接著性不足的情形。另一方面，當塗布量超過0.20g/m 2時，會有耐結塊性降低的情形。 (Easy-adhesive layer) The easily-adhesive layer is obtained by coating the coating solution on one or both surfaces of an unstretched or longitudinally uniaxially stretched film, drying at 100-150°C, and stretching in the transverse direction. It is better to manage the coating amount of the final easy-adhesive layer at 0.05-0.20 g/m 2 . When the coating amount is less than 0.05g/m 2 , the adhesion may be insufficient. On the other hand, when the coating amount exceeds 0.20 g/m 2 , the blocking resistance may decrease.

作為在易接著層上所使用之樹脂，係可無特別限制地使用例如聚酯樹脂、聚胺基甲酸酯樹脂、聚酯聚胺基甲酸酯樹脂、聚碳酸酯聚胺基甲酸酯樹脂、丙烯酸樹脂等。作為易接著層之交聯劑，可列舉出三聚氰胺、異氰酸酯化合物、

Figure 111123383-A0304-1
唑啉樹脂、環氧樹脂等。也可分別混合兩種以上來使用。該等係依模內塗布之性質，藉由水系塗布液進行塗布為佳，該樹脂或交聯劑係較佳係為水溶性或水分散性之樹脂和化合物。As the resin used for the easy-adhesive layer, for example, polyester resin, polyurethane resin, polyester polyurethane resin, polycarbonate polyurethane, etc. can be used without particular limitation. Resin, acrylic resin, etc. Examples of the crosslinking agent for the easy-adhesive layer include melamine, isocyanate compounds,
Figure 111123383-A0304-1
Oxazoline resin, epoxy resin, etc. It is also possible to mix and use two or more types respectively. These are based on the nature of in-mold coating, preferably by water-based coating solution, and the resin or crosslinking agent is preferably water-soluble or water-dispersible resin and compound.

為了要對易接著層賦予易滑性，較佳的是添加粒子。微粒之平均粒徑以2μm以下為佳。當粒子之平均粒徑超過2μm時，粒子會變得容易從易接著層脫落。作為易接著層所含有之粒子，例如可列舉出氧化鈦、硫酸鋇、碳酸鈣、硫酸鈣、二氧化矽、氧化鋁、滑石、高嶺土、黏土、磷酸鈣、雲母、水輝石、二氧化鋯、氧化鎢、氟化鋰、氟化鈣等之無機粒子；和苯乙烯系、丙烯酸系、三聚氰胺系、苯胍

Figure 111123383-A0304-2
系、矽酮系等之有機聚合物系粒子等。該等係可單獨添加至易接著層，亦可組合兩種以上而添加。In order to impart slipperiness to the easily-adhesive layer, it is preferable to add particles. The average particle size of the particles is preferably 2 μm or less. When the average particle diameter of the particles exceeds 2 μm, the particles tend to fall off from the easily-adhesive layer. Examples of particles contained in the easy-adhesive layer include titanium oxide, barium sulfate, calcium carbonate, calcium sulfate, silicon dioxide, aluminum oxide, talc, kaolin, clay, calcium phosphate, mica, hectorite, zirconium dioxide, Inorganic particles of tungsten oxide, lithium fluoride, calcium fluoride, etc.; and styrene, acrylic, melamine, benzoguanidine
Figure 111123383-A0304-2
Organic polymer-based particles such as silicone-based, silicone-based, etc. These may be added individually to an easy-adhesive layer, or may be added in combination of 2 or more types.

又，作為塗布塗布液之方法，可採用與上述塗布層相同的公知方法。例如可列舉出反轉滾筒塗布(reverse roll coating)法、凹版印刷塗布法、點觸塗布(kiss coating)法、滾筒閃塗法、噴塗法、氣刀塗布法、線狀棒塗法、管狀刮刀法等，該等方法可單獨進行或組合進行。Moreover, as a method of applying a coating liquid, the same well-known method as the above-mentioned coating layer can be employ|adopted. Examples include reverse roll coating, gravure coating, kiss coating, roll flash coating, spray coating, air knife coating, linear bar coating, tubular doctor blade These methods can be carried out alone or in combination.

(硬塗層) 位於折疊式顯示器之表面而保護顯示器之聚酯薄膜係宜至少其一表面上具有硬塗層。硬塗層較佳係使其位於聚酯薄膜上之顯示器表面側而使用於顯示器中。作為形成硬塗層之樹脂，可無特別限定地使用丙烯酸系、矽氧烷系、無機摻混系、胺基甲酸酯丙烯酸酯系、聚酯丙烯酸酯系、環氧系等。又，可以混合兩種以上材料而使用，也可以添加無機填料和有機填料等之粒子。 (hard coat) The polyester film which is located on the surface of the foldable display to protect the display preferably has a hard coating on at least one surface thereof. The hard coat layer is preferably used in the display so that it is on the display surface side on the polyester film. As the resin for forming the hard coat layer, acrylic, silicone, inorganic blend, urethane acrylate, polyester acrylate, epoxy and the like can be used without particular limitation. In addition, two or more kinds of materials may be mixed and used, and particles such as inorganic fillers and organic fillers may be added.

(硬塗層之膜厚) 作為硬塗層之膜厚，宜為1～40μm。若厚於1μm，則會充分硬化，可得到良好的鉛筆硬度。又，藉由將厚度設為40μm以下，可抑制因硬塗之硬化收縮所造成之翹曲，能夠提升薄膜之處理性。更佳的是2～20μm，再更佳的是3～15μm。 (film thickness of hard coat layer) The film thickness of the hard coat layer is preferably 1 to 40 µm. If it is thicker than 1 μm, it will be fully cured and good pencil hardness will be obtained. In addition, by setting the thickness to 40 μm or less, warpage due to curing shrinkage of the hard coat can be suppressed, and film handling properties can be improved. More preferably, it is 2 to 20 μm, and even more preferably, it is 3 to 15 μm.

(塗布方法) 作為硬塗層之塗布方法，可無特別限定地使用線狀棒塗布、凹版印刷塗布、模塗、刀塗等，可因應黏度、膜厚而適當地選擇。 (coating method) As the coating method of the hard coat layer, linear bar coating, gravure coating, die coating, knife coating, etc. can be used without particular limitation, and can be appropriately selected according to viscosity and film thickness.

(硬化條件) 作為硬塗層之硬化方法，可使用利用紫外線、電子線等能量線和熱之硬化方法等，為了要減輕對於薄膜的傷害，較佳的是利用紫外線和電子線等之硬化方法。 (hardening condition) As a method of hardening the hard coat layer, a curing method using energy rays such as ultraviolet rays and electron beams and heat can be used. In order to reduce damage to the film, a curing method using ultraviolet rays and electron beams is preferable.

(鉛筆硬度) 硬塗層之鉛筆硬度宜為B以上，更佳為H以上，特佳為2H以上。若為B以上之鉛筆硬度，則不會輕易受損，不會使視認性降低。一般來說，硬塗層之鉛筆硬度越高越好，但可為10H以下，也可為8H以下，而即便是6H以下，也可在實用上不會有問題地使用。 (pencil hardness) The pencil hardness of the hard coating is preferably B or higher, more preferably H or higher, and most preferably 2H or higher. If the pencil hardness is B or higher, it will not be easily damaged and will not reduce the visibility. Generally, the higher the pencil hardness of the hard coat layer, the better, but it may be 10H or less, or 8H or less, and even 6H or less can be used without any practical problems.

(硬塗層之特性) 本發明之硬塗層係可使用在提高如上所述之表面的鉛筆硬度而保護顯示器的目的上，以穿透率高者為較佳。作為硬塗薄膜之穿透率，宜為87%以上，更佳為88%以上。若穿透率為87%以上，可得到充分的視認性。硬塗薄膜之總光線穿透率一般來說是越高越好，但是可為99%以下，也可為97%以下。又，硬塗薄膜之霧值一般來說是越低越好，宜為3%以下。更佳的是硬塗薄膜之霧值為2%以下，最佳為1%以下。若霧值為3%以下，可使影像的視認性提高。霧值一般來說是越低越好，可為0.1%以上，也可為0.3%以上。 (Characteristics of hard coating) The hard coat layer of the present invention can be used for the purpose of improving the pencil hardness of the above-mentioned surface and protecting the display, and the one with high penetration rate is preferred. The transmittance of the hard coat film is preferably above 87%, more preferably above 88%. When the transmittance is 87% or more, sufficient visibility can be obtained. The total light transmittance of the hard-coated film is generally as high as possible, but it can be less than 99%, or less than 97%. Also, the haze value of the hard coat film is generally as low as possible, preferably below 3%. More preferably, the haze value of the hard coat film is less than 2%, most preferably less than 1%. If the fog value is less than 3%, the visibility of the image can be improved. Generally speaking, the lower the fog value, the better, it can be more than 0.1%, and it can also be more than 0.3%.

在硬塗層上，還可進一步追加其他機能。例如，具有如上述之一定鉛筆硬度之防眩層、防眩性抗反射層、抗反射層、低反射層及抗靜電層等附加有機能性之硬塗層也可以適當使用於本發明中。 [實施例] It is also possible to further add other functions to the hard coat layer. For example, a hard coat layer with added functions such as an anti-glare layer with a certain pencil hardness, an anti-glare anti-reflection layer, an anti-reflection layer, a low-reflection layer, and an antistatic layer can also be suitably used in the present invention. [Example]

接著，採用實施例及比較例來說明本發明之效果。首先，在本發明所實施之特性值的評價方法記載如下。Next, the effects of the present invention will be described using examples and comparative examples. First, the evaluation method of the characteristic value carried out in the present invention is described below.

(1)極限黏度 在將薄膜或聚酯樹脂予以粉碎並乾燥之後，溶解於苯酚/四氯乙烷=60/40(質量比)的混合溶劑中。對此溶液施以離心分離處理而去除無機粒子之後，使用烏氏黏度計，測定30℃下之0.4(g/dl)之濃度的溶液之流下時間及僅有溶劑之流下時間，依據該等之時間比例，使用Huggins之式，並假設Huggins常數為0.38，計算出極限黏度。 (1) Intrinsic viscosity After the film or polyester resin is pulverized and dried, it is dissolved in a mixed solvent of phenol/tetrachloroethane=60/40 (mass ratio). After subjecting this solution to centrifugation to remove inorganic particles, use an Ubbelohde viscometer to measure the flow-down time of a solution with a concentration of 0.4 (g/dl) at 30°C and the flow-down time of only the solvent. Time scale, using Huggins' formula, and assuming Huggins constant is 0.38, calculate the limiting viscosity.

(2)耐彎曲性 準備寬度方向50mm×流動方向100mm大小之硬塗薄膜樣本。使用無負擔U字型伸縮試驗機(湯淺系統機器公司製，DLDMLH-FS)，設定彎曲半徑2mm，以1次/秒的速度，使彎曲20萬次。此時，樣本係將長邊側兩端部10mm之位置固定住，而將彎曲部位作成50mm×80mm。於彎曲處理結束之後，以樣本之彎曲內側為下，放置在平面，施行目視檢查。 ◎：無法確認樣本的變形。 ○：樣本有變形，放置為水平時，浮起最大高度小於5mm。 ×：樣本上有折痕，放置為水平時，浮起最大高度為5mm以上。 (2) Bending resistance A hard coat film sample having a size of 50 mm in the width direction x 100 mm in the flow direction was prepared. Using an unloaded U-shaped stretch testing machine (manufactured by Yuasa System Equipment Co., Ltd., DLDMLH-FS), the bending radius was set at 2 mm, and the bending was performed 200,000 times at a speed of 1 time/second. At this time, the position of the sample was fixed at 10 mm from both ends of the long side, and the bent portion was made 50 mm×80 mm. After the bending process is completed, place the sample on a plane with the inner side of the bend as the bottom, and perform visual inspection. ⊚: Deformation of the sample could not be confirmed. ○: The sample is deformed, and when it is placed horizontally, the maximum floating height is less than 5mm. ×: There are creases on the sample, and when placed horizontally, the maximum floating height is 5 mm or more.

(3)折射率 根據JIS K 7142-2008「塑膠之折射率測定方法(A法)」，使用阿貝折射率計(ATAGO公司製，NAR-4T，測定波長589nm)，求取長邊方向之折射率、寬度方向之折射率。 (3) Refractive index According to JIS K 7142-2008 "Measurement method of refractive index of plastics (Method A)", using Abbe refractometer (manufactured by ATAGO, NAR-4T, measuring wavelength 589nm), the refractive index in the long side direction and the width direction are calculated of the refractive index.

(4)鉛筆硬度 以硬塗薄膜之鉛筆硬度為樣本，根據JIS K 5600-5-4：1999，在負重750g、速度1.0mm/s下進行測定。 (4) Pencil hardness Taking the pencil hardness of the hard-coated film as a sample, it was measured under a load of 750g and a speed of 1.0mm/s according to JIS K 5600-5-4:1999.

(5)總光線穿透率、霧值 以硬塗薄膜為樣本，使用霧值計(日本電色工業公司製，NDH5000)進行測定。 (5) Total light transmittance, fog value The hard coat film was used as a sample, and it measured using the haze meter (made by Nippon Denshoku Kogyo Co., Ltd., NDH5000).

(聚對苯二甲酸乙二酯顆粒(a)之調製) 作為酯化反應裝置，使用具有攪拌裝置、分餾器、原料添加口及產物取出口之由3段完全混合槽所構成之連續酯化反應裝置，將TPA設為2噸/小時，將EG設為相對於1莫耳TPA之2莫耳，將三氧化銻設為相對於生成PET而Sb原子成為160ppm的量，將該等漿料連續供給至酯化反應裝置之第一酯化反應槽，於常壓下依平均滯留時間4小時，使其於255℃下進行反應。接著，將上述第一酯化反應槽之反應產物連續地取出系統外，供給至第二酯化反應槽，在第二酯化反應槽內，將從第一酯化反應槽餾去之EG依相對於生成聚合物(生成PET)而供給8質量%，接下來，添加：相對於生成PET而Mg原子成為65ppm之量的包含醋酸鎂的EG溶液；與相對於生成PET而P原子成為20ppm之量的包含TMPA的EG溶液，於常壓下依平均滯留時間1.5小時，使其於260℃下進行反應。接著，將上述第二酯化反應槽之反應產物連續地取出系統外，供給至第三酯化反應槽，再來，添加相對於生成PET而P原子成為20ppm的量之包含TMPA的EG溶液，於常壓下依平均滯留時間0.5小時，使其於260℃下進行反應。將於上述第三酯化反應槽內所生成之酯化反應產物連續地供給至3段之連續聚縮合反應裝置，進行聚縮合，接下來，利用不鏽鋼燒結體之過濾材料(公稱過濾精度5μm粒子隔除90%)進行過濾，得到極限黏度0.62dl/g之聚對苯二甲酸乙二酯顆粒(a)。 (Preparation of polyethylene terephthalate particles (a)) As an esterification reaction device, a continuous esterification reaction device consisting of a three-stage complete mixing tank with a stirring device, a fractionator, a raw material addition port, and a product withdrawal port is used. TPA is set to 2 tons/hour, and EG is set to With respect to 2 moles of 1 mole of TPA, antimony trioxide was set to an amount of 160 ppm of Sb atoms with respect to the production of PET, and these slurries were continuously supplied to the first esterification reaction tank of the esterification reaction device. The reaction was carried out at 255° C. according to the average residence time of 4 hours under normal pressure. Next, the reaction product of the above-mentioned first esterification reaction tank is continuously taken out of the system and supplied to the second esterification reaction tank. In the second esterification reaction tank, the EG distilled from the first esterification reaction tank is 8% by mass was supplied with respect to the produced polymer (produced PET), and then added: an EG solution containing magnesium acetate in an amount of 65 ppm of Mg atoms relative to the produced PET; and 20 ppm of P atoms relative to the produced PET A large amount of EG solution containing TMPA was reacted at 260° C. under normal pressure with an average residence time of 1.5 hours. Next, the reaction product in the above-mentioned second esterification reaction tank was continuously taken out of the system, supplied to the third esterification reaction tank, and then, an EG solution containing TMPA was added in an amount of 20 ppm of P atoms relative to the produced PET, The reaction was carried out at 260° C. under normal pressure with an average residence time of 0.5 hours. The esterification reaction product generated in the above-mentioned third esterification reaction tank is continuously supplied to the 3-stage continuous polycondensation reaction device for polycondensation, and then, the filter material of stainless steel sintered body (nominal filtration fineness 5 μm particles Cut off 90%) to filter to obtain polyethylene terephthalate particles (a) with an limiting viscosity of 0.62dl/g.

(聚對苯二甲酸乙二酯顆粒(b)之調製) 在聚對苯二甲酸乙二酯顆粒(a)之製造步驟中，除了調節第三酯化反應之滯留時間之外，依相同方法，調整極限黏度為0.580dl/g，得到聚對苯二甲酸乙二酯顆粒(b)。 (Preparation of polyethylene terephthalate particles (b)) In the manufacturing step of polyethylene terephthalate particles (a), in addition to adjusting the residence time of the third esterification reaction, according to the same method, adjust the limit viscosity to 0.580dl/g to obtain polyethylene terephthalic acid Ethylene glycol granules (b).

(聚對苯二甲酸乙二酯顆粒(c)之調製) 使用旋轉型真空聚合裝置，在0.5mmHg的減壓下，於220℃下改變時間，將聚對苯二甲酸乙二酯顆粒(a)予以固相聚合，作成極限黏度0.75dl/g之聚對苯二甲酸乙二酯顆粒(c)。 (Preparation of polyethylene terephthalate particles (c)) Using a rotary vacuum polymerization device, under a reduced pressure of 0.5mmHg, the polyethylene terephthalate particles (a) are solid-phase polymerized at 220°C to produce a polypair with an intrinsic viscosity of 0.75dl/g. Ethylene phthalate particles (c).

(胺基甲酸酯樹脂之聚合) 對於具備攪拌機、戴氏冷凝器、氮氣導入管、二氧化矽凝膠乾燥管及溫度計的4口燒瓶，添加入1,3-雙(異氰酸酯甲基)環己烷72.96質量份、二羥甲基丙酸12.60質量份、新戊二醇11.74質量份、數量平均分子量2000之聚碳酸酯二醇112.70質量份、及作為溶劑的丙腈85.00質量份、N-甲基吡咯啶酮5.00質量份，在氮氣環境下，於75℃攪拌3小時，確認反應液達到既定胺當量。接著，於將此反應液降溫至40℃之後，添加三乙胺9.03質量份，得到聚胺基甲酸酯預聚物D溶液。再來，對於具備可高速攪拌之均質器的反應容器，添加水450g，調整為25℃，依2000min -1進行攪拌混合，添加異氰酸酯基末端預聚物，進行水分散。其後，於減壓下，去除丙腈及一部分的水，藉以調製固體含量35質量%之水溶性聚胺基甲酸酯樹脂(A)。 (Polymerization of urethane resin) Add 1,3-bis(isocyanate methyl) cyclo 72.96 parts by mass of hexane, 12.60 parts by mass of dimethylolpropionic acid, 11.74 parts by mass of neopentyl glycol, 112.70 parts by mass of polycarbonate diol with a number average molecular weight of 2000, and 85.00 parts by mass of propionitrile as a solvent, N- 5.00 parts by mass of methylpyrrolidone was stirred at 75° C. for 3 hours under a nitrogen atmosphere, and it was confirmed that the reaction liquid reached a predetermined amine equivalent. Next, after cooling this reaction liquid to 40 degreeC, 9.03 mass parts of triethylamines were added, and the polyurethane prepolymer D solution was obtained. Next, 450 g of water was added to a reaction vessel equipped with a homogenizer capable of high-speed stirring, and the temperature was adjusted to 25° C., and stirred and mixed for 2000 min −1 , and the isocyanate group-terminated prepolymer was added to perform water dispersion. Thereafter, propionitrile and a part of water were removed under reduced pressure to prepare a water-soluble polyurethane resin (A) with a solid content of 35% by mass.

(水溶性碳二亞胺之聚合) 對於具備溫度計、氮氣導入管、迴流冷卻器、低下漏斗及攪拌機之燒瓶，添加入異佛爾酮二異氰酸酯200質量份、碳二亞胺化觸媒之3-甲基-1-苯基-2-磷-1-氧化物4質量份，於氮氣環境下，在180℃下，攪拌10小時，得到異氰酸酯末端異佛爾酮碳二亞胺(聚合度=5)。其次，使所得到之碳二亞胺111.2g、聚乙二醇單甲基醚(分子量400)80g於100℃下反應24小時。於50℃下緩慢添加水於其中，得到固體含量40質量%之黃色透明水溶性碳二亞胺化合物(B)。 (polymerization of water-soluble carbodiimide) For a flask equipped with a thermometer, a nitrogen inlet tube, a reflux cooler, a lower funnel, and a stirrer, add 200 parts by mass of isophorone diisocyanate and 3-methyl-1-phenyl-2 - 4 parts by mass of phosphorus-1-oxide, stirred at 180° C. for 10 hours under nitrogen atmosphere to obtain isophorone carbodiimide with isocyanate terminal (polymerization degree=5). Next, 111.2 g of the obtained carbodiimide and 80 g of polyethylene glycol monomethyl ether (molecular weight: 400) were reacted at 100° C. for 24 hours. Water was slowly added thereto at 50° C. to obtain a yellow transparent water-soluble carbodiimide compound (B) with a solid content of 40% by mass.

(易接著層塗布液之調製) 混合如下所述塗劑，作成塗布液。 水                                         16.97質量份 異丙醇                                   21.96質量份 聚胺基甲酸酯樹脂(A)                3.27質量份 水溶性碳二亞胺化合物(B)          1.22質量份 粒子                                        0.51質量份 (平均粒徑40nm之二氧化矽凝膠，固體含量濃度40質量%) 界面活性劑                              0.05質量份 (矽酮系，固體含量濃度100質量%) (Preparation of coating solution for easy adhesive layer) The coating agents described below were mixed to prepare a coating solution. Water 16.97 parts by mass Isopropanol 21.96 parts by mass Polyurethane resin (A) 3.27 parts by mass Water-soluble carbodiimide compound (B) 1.22 parts by mass Particles 0.51 parts by mass (Silica gel with an average particle diameter of 40nm and a solid content concentration of 40% by mass) Surfactant 0.05 parts by mass (Silicone-based, solid content concentration 100% by mass)

於將上述聚對苯二甲酸乙二酯母料顆粒(a)依180℃減壓乾燥(3Torr)8小時之後，對於壓出機，將聚對苯二甲酸乙二酯之顆粒(a)分別供給至壓出機，在285℃下進行熔解。利用不鏽鋼燒結體之過濾材料(公稱過濾精度10μm粒子隔除95%)將此聚合物予以過濾，從噴嘴壓出成片狀後，採用靜電施加澆鑄法，使其接觸到表面溫度30℃之澆鑄滾輪，進行冷卻固化，製作未延伸薄膜。於長邊方向上不延伸此未延伸薄膜(延伸時，在85℃下進行延伸)，利用滾筒塗布法將該塗布液塗布在PET薄膜的單面上之後，在80℃下乾燥20秒鐘。另外，調整最終(雙軸延伸後)之乾燥後的塗布量成為0.06g/m 2。其後，採用拉幅機將此薄膜於95℃下在寬度方向上延伸4.0倍，於220℃下熱處理5秒鐘，得到表1之No.1的聚對苯二甲酸乙二酯薄膜。除了進行若干條件調整之外，依與上述幾乎相同之步驟，供給聚對苯二甲酸乙二酯母料顆粒(b)～(c)，得到表1之No.2～9的聚對苯二甲酸乙二酯薄膜。 After the above-mentioned polyethylene terephthalate masterbatch particles (a) were dried under reduced pressure at 180°C (3 Torr) for 8 hours, for the extruder, the polyethylene terephthalate particles (a) were respectively It supplied to an extruder, and melt|dissolved at 285 degreeC. Use the filter material of stainless steel sintered body (nominal filtration precision 10μm particles to remove 95%) to filter the polymer, press it out from the nozzle into a sheet, and use electrostatic casting method to make it contact with the surface temperature of 30 ℃. Roller for cooling and solidification to make unstretched film. This unstretched film was not stretched in the longitudinal direction (stretching was performed at 85° C.), and the coating solution was applied to one side of the PET film by a roll coating method, followed by drying at 80° C. for 20 seconds. In addition, the final (after biaxial stretching) coating weight after drying was adjusted to be 0.06 g/m 2 . Thereafter, this film was stretched 4.0 times in the width direction at 95° C. using a tenter, and heat-treated at 220° C. for 5 seconds to obtain a polyethylene terephthalate film No. 1 in Table 1. Except for some condition adjustments, according to almost the same steps as above, supply polyethylene terephthalate masterbatch particles (b) to (c) to obtain polyethylene terephthalate No.2 to 9 in Table 1. Ethylene formate film.

(硬塗塗布液a之調製) 對於含有丙烯酸酯系無機奈米填料之硬塗劑(日揮觸媒化成公司製，ELCOM(註冊商標)LP-1001，固體含量濃度61%)100重量份，添加均平劑(BYK日本公司製，BYK307，固體含量濃度100%)0.1重量份，利用MEK進行稀釋，調製出固體含量濃度40質量%之硬塗塗布液a。 (Preparation of hard coating solution a) For 100 parts by weight of the hard coating agent containing acrylate-based inorganic nano-fillers (made by Nikki Catalyst Chemical Co., Ltd., ELCOM (registered trademark) LP-1001, solid content concentration 61%), add leveling agent (manufactured by BYK Japan Co., Ltd., BYK307, 0.1 parts by weight of solid content concentration (100%), was diluted with MEK to prepare a hard coating solution a with a solid content concentration of 40 mass%.

(硬塗塗布液b之調製) 將胺基甲酸酯丙烯酸酯系硬塗劑(荒川化學工業公司製，beamset(註冊商標)577，固體含量濃度100%)95重量份、光聚合起始劑(BASF日本公司製，Irgacure(註冊商標)184，固體含量濃度100%)5重量份、均平劑(BYK日本公司製，BYK307，固體含量濃度100%)0.1重量份予以混合，利用甲苯/MEK=1/1的溶劑進行稀釋，調製出濃度40%的塗布液b。 (Preparation of hard coating liquid b) Urethane acrylate hard coating agent (made by Arakawa Chemical Industry Co., Ltd., beamset (registered trademark) 577, solid content concentration 100%) 95 parts by weight, photopolymerization initiator (made by BASF Japan Co., Ltd., Irgacure (registered trademark) Trademark) 184, 5 parts by weight of solid content concentration 100%), leveling agent (manufactured by BYK Japan Co., Ltd., BYK307, 100% solid content concentration) 0.1 parts by weight are mixed, and diluted with a solvent of toluene/MEK=1/1, A coating solution b with a concentration of 40% was prepared.

(實施例1) 使用線狀棒，以乾燥後膜厚成為5.0μm的方式，將硬塗塗布液a塗布在聚對苯二甲酸乙二酯薄膜No.3之其中一面上，在80℃下乾燥1分鐘之後，照射紫外線(高壓水銀燈，累積光量200mJ/cm 2)，得到硬塗薄膜。 (Example 1) Using a linear rod, the hard coat coating liquid a was coated on one side of polyethylene terephthalate film No. 3 so that the film thickness after drying became 5.0 μm, and the After drying for 1 minute, ultraviolet rays (high-pressure mercury lamp, cumulative light intensity: 200 mJ/cm 2 ) were irradiated to obtain a hard coat film.

(實施例2～8、比較例1～2) 利用與實施例1相同的方法，作成表2中之條件下的硬塗薄膜。 (Examples 2-8, Comparative Examples 1-2) By the same method as in Example 1, hard coat films under the conditions in Table 2 were prepared.

隔著25μm厚之黏著層，將所作成之薄膜貼合至有機EL模組上，作成在圖1之相當於彎曲半徑之半徑3mm整體的中央部可對折的智慧型手機類型之折疊式顯示器。硬塗薄膜係配置於連著折疊部分之連續一片顯示器的表面上，將硬塗層配置成位於該顯示器的表面。使用各實施例之硬塗薄膜者係作成為於中央部可對折地進行折疊並攜帶之智慧型手機，而滿足運作及視認性者。另一方面，使用各比較例之硬塗薄膜之折疊式顯示器係隨著使用頻率的增加，感覺到在顯示器之折疊部產生影像的歪斜，而不是較佳者。The produced film was bonded to an organic EL module through a 25 μm thick adhesive layer to make a smart phone-type foldable display that can be folded in half at the center of the whole with a radius of 3 mm, which is equivalent to the bending radius in FIG. 1 . The hard coat film is disposed on the surface of a continuous display connected to the folded portion, and the hard coat is disposed on the surface of the display. Those using the hard-coat films of the respective examples are made into smartphones that can be folded and carried in half at the central part, and satisfy the operability and visibility. On the other hand, the foldable displays using the hard-coated films of the comparative examples are not preferable because of the distortion of the image at the folded portion of the display as the frequency of use increases.

表1 薄膜 No. PET顆粒 PET薄膜 種類 極限黏度 (dl/g) 極限黏度 (dl/g) 延伸倍率   折射率 長邊方向 寬度方向 厚度 (μm) 長邊方向 (彎曲方向) 寬度方向 (折疊部之方向) 1 (a) 0.62 0.58 1.0 4.0 50 1.588 1.694 2 (a) 0.62 0.58 1.4 4.0 50 1.601 1.684 3 (a) 0.62 0.58 2.7 4.0 50 1.631 1.686 4 (a) 0.62 0.58 3.4 4.0 50 1.650 1.669 5 (a) 0.62 0.58 1.4 4.0 25 1.591 1.676 6 (a) 0.62 0.58 1.4 4.0 75 1.623 1.690 7 (b) 0.58 0.54 1.4 4.0 50 1.598 1.682 8 (c) 0.75 0.69 1.4 4.0 50 1.603 1.686 9 (c) 0.75 0.69 3.4 4.0 50 1.648 1.679 PET：聚對苯二甲酸乙二酯 Table 1 Film No. PET particles PET film type Intrinsic viscosity (dl/g) Intrinsic viscosity (dl/g) Extension ratio Refractive index Long side direction Width direction Thickness (μm) Long side direction (bending direction) Width direction (folding direction) 1 (a) 0.62 0.58 1.0 4.0 50 1.588 1.694 2 (a) 0.62 0.58 1.4 4.0 50 1.601 1.684 3 (a) 0.62 0.58 2.7 4.0 50 1.631 1.686 4 (a) 0.62 0.58 3.4 4.0 50 1.650 1.669 5 (a) 0.62 0.58 1.4 4.0 25 1.591 1.676 6 (a) 0.62 0.58 1.4 4.0 75 1.623 1.690 7 (b) 0.58 0.54 1.4 4.0 50 1.598 1.682 8 (c) 0.75 0.69 1.4 4.0 50 1.603 1.686 9 (c) 0.75 0.69 3.4 4.0 50 1.648 1.679 PET: polyethylene terephthalate

表2   基材PET薄膜 硬塗薄膜 薄膜No. 極限黏度 (dl/g) 厚度 (μm) 彎曲方向 (長邊方向)折射率 硬塗層 評價結果 塗布液 厚度(μm) 耐彎曲性 總光線穿透率(%) 霧值(%) 鉛筆硬度 實施例1 3 0.58 50 1.631 a 5 ○ 90.2 0.4 2H 實施例2 5 0.58 25 1.591 a 5 ◎ 90.3 0.3 H 實施例3 6 0.58 75 1.623 a 5 ○ 90.0 0.4 2H 實施例4 1 0.58 50 1.588 a 5 ◎ 90.2 0.3 2H 實施例5 2 0.58 50 1.601 a 5 ◎ 90.2 0.3 2H 實施例6 1 0.58 50 1.588 a 10 ○ 90.2 0.2 3H 實施例7 7 0.54 50 1.598 a 5 ○ 90.2 0.3 H 實施例8 8 0.69 50 1.603 a 5 ○ 90.2 0.3 2H 實施例9 3 0.58 50 1.631 b 5 ○ 90.2 0.3 2H 比較例1 4 0.58 50 1.650 a 5 × 90.2 0.3 2H 比較例2 9 0.69 50 1.648 a 5 × 90.2 0.3 2H PET：聚對苯二甲酸乙二酯 [產業上利用之可能性] Table 2 Substrate PET film Hard Coated Film Film No. Intrinsic viscosity (dl/g) Thickness (μm) Bending direction (long side direction) refractive index hard coat Evaluation results Coating solution Thickness (μm) Bending resistance Total light transmittance (%) Fog value (%) pencil hardness Example 1 3 0.58 50 1.631 a 5 ○ 90.2 0.4 2H Example 2 5 0.58 25 1.591 a 5 ◎ 90.3 0.3 h Example 3 6 0.58 75 1.623 a 5 ○ 90.0 0.4 2H Example 4 1 0.58 50 1.588 a 5 ◎ 90.2 0.3 2H Example 5 2 0.58 50 1.601 a 5 ◎ 90.2 0.3 2H Example 6 1 0.58 50 1.588 a 10 ○ 90.2 0.2 3H Example 7 7 0.54 50 1.598 a 5 ○ 90.2 0.3 h Example 8 8 0.69 50 1.603 a 5 ○ 90.2 0.3 2H Example 9 3 0.58 50 1.631 b 5 ○ 90.2 0.3 2H Comparative example 1 4 0.58 50 1.650 a 5 x 90.2 0.3 2H Comparative example 2 9 0.69 50 1.648 a 5 x 90.2 0.3 2H PET: Polyethylene terephthalate [possibility of industrial use]

如依據使用本發明之折疊式顯示器之表面保護薄膜用聚酯薄膜和硬塗薄膜的折疊式顯示器，則可維持量產性，且不會引起位於折疊式顯示器表面之聚酯薄膜和硬塗薄膜經反覆折疊後的變形，所以不會有顯示器之折疊部分產生影像紊亂的情形。搭載有將本發明之聚酯薄膜和硬塗薄膜當作表面保護薄膜而使用之折疊式顯示器的攜帶式終端機器係可提供美麗的影像，為機能性豐富、攜帶性等便利性優異之物。According to the foldable display using the polyester film and hard-coat film for the surface protection film of the foldable display of the present invention, mass productivity can be maintained, and the polyester film and hard-coat film on the surface of the foldable display will not be caused. Deformation after repeated folding, so there will be no image disorder in the folded part of the display. Portable terminal equipment equipped with a foldable display using the polyester film and hard-coat film of the present invention as a surface protection film can provide beautiful images, and is highly functional and convenient in terms of portability.

1:折疊式顯示器 2:折疊式顯示器之表面保護薄膜用聚酯薄膜 11:彎曲半徑 21:折疊部 22:彎曲方向(與折疊部正交的方向) 1: Foldable display 2: Polyester film for surface protection film of folding display 11: bending radius 21: Folding part 22: Bending direction (direction perpendicular to the folded part)

圖1係用以顯示出將本發明之折疊式顯示器予以折疊時之彎曲半徑之測定處的示意圖。 圖2係用以顯示出本發明之折疊式顯示器之表面保護薄膜用聚酯薄膜之彎曲方向的示意圖。 Fig. 1 is a schematic view showing the measuring point of the bending radius when the folding display of the present invention is folded. Fig. 2 is a schematic view showing the bending direction of the polyester film for the surface protection film of the foldable display of the present invention.

1:折疊式顯示器 1: Foldable display

11:彎曲半徑 11: bending radius

Claims (5)

一種顯示器用聚酯薄膜，其依據JIS K 7142-2008以測定波長589nm所測得之長邊方向及寬度方向之至少其一方向的折射率為1.57～1.64，且 具有彎曲方向， 其中，彎曲方向係指折疊聚酯薄膜時之與折疊部正交的方向。 A polyester film for displays, which has a refractive index of at least one of the longitudinal direction and the width direction measured at a wavelength of 589 nm in accordance with JIS K 7142-2008, and is 1.57 to 1.64, and has a bending direction, Here, the bending direction refers to the direction perpendicular to the folded portion when the polyester film is folded. 如請求項1之顯示器用聚酯薄膜，其中彎曲方向之折射率為1.57～1.64，該彎曲方向之折射率係依據JIS K 7142-2008以測定波長589nm所測得。The polyester film for display according to Claim 1, wherein the refractive index in the bending direction is 1.57-1.64, and the refractive index in the bending direction is measured at a wavelength of 589 nm according to JIS K 7142-2008. 如請求項1或2之顯示器用聚酯薄膜，其中顯示器為折疊式顯示器或具有觸控面板之攜帶式終端機器。The polyester film for display according to claim 1 or 2, wherein the display is a foldable display or a portable terminal device with a touch panel. 一種顯示器用硬塗薄膜，其在如請求項1至3中任一項之顯示器用聚酯薄膜的至少單面上，具有厚度1～40μm之硬塗層。A hard-coated film for displays, which has a hard-coated layer with a thickness of 1-40 μm on at least one side of the polyester film for displays according to any one of claims 1 to 3. 如請求項4之顯示器用硬塗薄膜，其在耐彎曲性試驗中，沒有確認到利用目視檢查之變形； 其中，耐彎曲性試驗為如下試驗：對於寬度方向50mm×流動方向100mm大小之硬塗薄膜樣本，藉由無負擔U字型伸縮試驗機，以彎曲半徑2mm、1次/秒的速度，使彎曲20萬次。 For the hard-coated film for displays in claim 4, no deformation is confirmed by visual inspection in the bending resistance test; Among them, the bending resistance test is the following test: For a hard-coated film sample with a size of 50 mm in the width direction and 100 mm in the flow direction, bend it at a bending radius of 2 mm and at a speed of 1 time per second by using an unloaded U-shaped stretch testing machine. 200,000 times.
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