WO2012086592A1 - Film polyester pour application optique - Google Patents

Film polyester pour application optique Download PDF

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Publication number
WO2012086592A1
WO2012086592A1 PCT/JP2011/079374 JP2011079374W WO2012086592A1 WO 2012086592 A1 WO2012086592 A1 WO 2012086592A1 JP 2011079374 W JP2011079374 W JP 2011079374W WO 2012086592 A1 WO2012086592 A1 WO 2012086592A1
Authority
WO
WIPO (PCT)
Prior art keywords
film
polyester
transparency
particles
polyester film
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/JP2011/079374
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English (en)
Japanese (ja)
Inventor
加藤優佳
尼子勝也
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsubishi Chemical Corp
Original Assignee
Mitsubishi Plastics Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Mitsubishi Plastics Inc filed Critical Mitsubishi Plastics Inc
Publication of WO2012086592A1 publication Critical patent/WO2012086592A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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Classifications

    • 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
    • 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
    • G02B1/04—Optical elements characterised by the material of which they are made; Optical coatings for optical elements made of organic materials, e.g. plastics
    • 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
    • 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
    • C08J2367/00—Characterised by the use of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Derivatives of such polymers
    • G02B1/105—

Definitions

  • the present invention relates to an optical polyester film, and more particularly, it has excellent clear feeling when used as a base film for a transparent conductive film of a touch panel display member, prevents optical defects due to adhesion of dust and the like, and is scratched.
  • the present invention relates to an optical polyester film excellent in prevention, workability, and productivity.
  • Biaxially stretched polyester films represented by polyethylene terephthalate and polyethylene naphthalate have excellent mechanical strength, dimensional stability, flatness, heat resistance, chemical resistance, optical properties, etc., and cost performance. It is also used for various purposes.
  • the touch panel display member is provided with a hard-coated film on both sides or one side and a transparent conductive film (ITO film) on the other side in terms of durability at pen input and good writing due to the cushioning effect of the adhesive.
  • ITO film transparent conductive film
  • an ITO film used as a transparent conductive film is usually crystallized by heat treatment at 150 ° C. for about 30 minutes (Patent Document 1). . Further, when this ITO film is crystallized in the form shown in Patent Document 2, a low molecular weight substance (oligomer) of PET is deposited on the back surface of the ITO film, that is, on the adhesive side, resulting in an optical defect (bright spot). It becomes a problem.
  • haze measurement There is a haze measurement as one of the methods for evaluating the transparency of a film.
  • haze There are two types of haze: surface haze and internal haze.
  • Surface haze is a physical property that evaluates scattering caused by the surface structure (rough surface, etc.) of the film.
  • Internal haze is scattering caused by the internal structure (void, etc.) of the film. It is a physical property evaluated. Therefore, according to the internal haze, it is possible to predict the haze value when the film is laminated with another material (hard coat or adhesive material, etc.) and laminated (excluding scattering caused by the surface structure). it can.
  • the measurement of the internal haze of a polyester film can be easily performed by using ethanol as a rough surface compensation solvent.
  • Patent Document 3 Even a highly transparent polyester film having an internal haze of 0.6% or less shown in Patent Document 3 has a particle feeling confirmed by visual inspection. In other words, the transparency of the film cannot be sufficiently evaluated with the internal haze value, and the demand for a film with excellent transparency has not yet been met.
  • the present invention has been made in view of the above circumstances, and its solution is an optical that is excellent in transparency and sharpness when used as a display member, hardly scratched, and has excellent workability and productivity. It is to provide a polyester film.
  • the first gist of the present invention resides in an optical polyester film characterized in that the transparency is 83.5% or more and the roughness (Ra) of one film surface is 9.0 nm or more.
  • the second gist of the present invention resides in an optical polyester film characterized in that the internal transparency is 96.5% or more and the roughness (Ra) of one film surface is 9.0 nm or more.
  • polyester film of the present invention it is possible to provide an optical polyester film that is excellent in visibility as a display member such as a display, has few scratches on the film surface, and has excellent workability.
  • the polyester film referred to in the present invention is a film that is melt-extruded from an extrusion die, and is subjected to stretching and heat treatment as necessary after cooling a molten polyester sheet extruded by a so-called extrusion method.
  • the polyester constituting the film of the present invention is obtained by polycondensation of an aromatic dicarboxylic acid and an aliphatic glycol.
  • aromatic dicarboxylic acid include terephthalic acid and 2,6-naphthalenedicarboxylic acid
  • aliphatic glycol include ethylene glycol, diethylene glycol, and 1,4-cyclohexanedimethanol.
  • Representative polyesters include polyethylene terephthalate (PET), polyethylene-2,6-naphthalenedicarboxylate (PEN), and the like.
  • PET polyethylene terephthalate
  • PEN polyethylene-2,6-naphthalenedicarboxylate
  • the polyester used may be a homopolyester or a copolyester.
  • a copolyester it may be a copolymer containing 30 mol% or less of the third component.
  • the dicarboxylic acid component of such a copolyester include isophthalic acid, phthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, sebacic acid, and oxycarboxylic acid (eg, P-oxybenzoic acid). 1 type or 2 types or more chosen from are mentioned.
  • One glycol component may be one or more selected from ethylene glycol, diethylene glycol, propylene glycol, butanediol, 1,4-cyclohexanedimethanol, neopentyl glycol, and the like.
  • a weathering agent a light-proofing agent, an antistatic agent, a lubricant, a light-shielding agent, an antioxidant, a fluorescent whitening agent, a matting agent, and a heat-stabilizing agent as long as the gist of the invention is not impaired
  • Examples of the particles to be blended in the film include silicon oxide, alumina, calcium carbonate, kaolin, titanium oxide, organic particles, and crosslinked polymer fine powder as described in JP-B-59-5216. These particles may be used alone or in combination of two or more components.
  • the blending amount of these particles is usually 5 to 90 ppm or less, preferably 20 to 80 ppm with respect to the polyester constituting the film.
  • the content of the particles is small, the film surface cannot be appropriately roughened, and in the film production process, there is a tendency that the surface is easily scratched or the winding properties are inferior.
  • the content of the particles is 90 ppm or more, the degree of roughening of the film surface becomes too large, and transparency may be impaired.
  • a method of blending particles only in the surface layer is preferably employed.
  • the surface layer in this case is at least one of the front and back layers, and of course, particles can be blended in both the front and back layers.
  • the blending amount of the particles in the case of such a laminated film is preferably in the range of 0.01 to 2% by weight, more preferably 0.02 to 1% by weight with respect to the polyester constituting the surface layer.
  • a sharp particle size distribution is preferably used.
  • those having a particle size distribution value of 1.0 to 2.0, which is an index representing the sharpness of the particle size distribution are preferable.
  • the particle size distribution value is the particle size distribution value d25 / d75 (d25 and d75 are calculated by calculating the accumulated accumulation of the particle group from the large particle side, and the particle size ( ⁇ m corresponding to 25% and 75% of the total volume, respectively) Is a value defined by When the particle size distribution value exceeds 2.0, transparency may be insufficient.
  • the present invention includes two inventions that define the transparency and internal transparency of the film.
  • the meanings of transparency and internal transparency are the same as those described above for haze and internal haze.
  • the transparency of the film in the measuring method mentioned later needs to be 83.5% or more, and it is preferable that it is 84.0% or more. When the transparency of the film is less than 83.5%, the transparency of the film is lowered.
  • the internal transparency of the film in the measurement method described later needs to be 96.5% or more, and preferably 97.0% or more. When the transparency of the film is less than 96.5%, the transparency of the film is lowered.
  • the film production line It can be achieved by appropriately combining various conditions such as smoothing of the roll used in the above.
  • the surface roughness (Ra) of the film is usually 9.0 nm or more, more preferably 12.0 nm or more.
  • Ra of the film is less than 9.0 nm, the film surface becomes extremely flat, and the winding characteristics in the film manufacturing process are inferior.
  • Ra of the film exceeds 22.0 nm, the planarity of the surface may be impaired, and the film may become whitish. Therefore, the upper limit of Ra is preferably 22.0 nm.
  • the method of blending the particles with the polyester is not particularly limited, and a known method can be adopted.
  • it can be added at any stage for producing the polyester, but it is preferably added as a slurry dispersed in ethylene glycol or the like at the stage of esterification or before the start of the polycondensation reaction after the transesterification reaction.
  • the condensation reaction may proceed.
  • the polyester may be chipped after melt polymerization, and further subjected to solid phase polymerization as necessary under heating under reduced pressure or in an inert gas stream such as nitrogen.
  • the intrinsic viscosity of the obtained polyester is preferably 0.40 dL / g or more, more preferably 0.40 to 0.90 dL / g.
  • the total thickness of the film of the present invention is not particularly limited as long as it can be formed as a film, but is usually 4 to 300 ⁇ m, preferably 25 to 188 ⁇ m.
  • a polyester chip obtained as described above and dried by a known method is supplied to a melt-extrusion apparatus and heated to a temperature equal to or higher than the melting point of each polymer to melt.
  • the molten polymer is extruded from the die, and rapidly cooled and solidified on the rotary cooling drum so as to have a temperature equal to or lower than the glass transition temperature to obtain a substantially amorphous unoriented sheet.
  • an electrostatic application adhesion method and / or a liquid application adhesion method is preferably employed.
  • the sheet thus obtained is stretched biaxially to form a film.
  • the unstretched sheet is preferably stretched 2 to 6 times in the machine direction at 70 to 145 ° C. to form a uniaxially stretched film, and then 2 to 90 to 160 ° C. in the transverse direction.
  • the film is preferably stretched up to 6 times and heat-treated at 150-240 ° C. for 1-600 seconds. Further, at this time, it is preferable to relax by 0.1 to 20% in the longitudinal direction and / or the transverse direction in the maximum temperature zone of the heat treatment and / or the cooling zone at the heat treatment outlet. Further, it is possible to add re-longitudinal stretching and re-lateral stretching as necessary. Further, it is possible to simultaneously biaxially stretch the unstretched sheet so that the area magnification is 10 to 40 times.
  • the polyester film of the present invention can be subjected to so-called in-line coating in which the film surface is treated during the stretching step as long as the effects of the present invention are not impaired.
  • in-line coating in which the film surface is treated during the stretching step as long as the effects of the present invention are not impaired.
  • a coating treatment with an aqueous solution, an aqueous emulsion, an aqueous slurry, or the like can be performed.
  • Various coatings may be performed by offline coating after film production. Such a coat may be either single-sided or double-sided.
  • the coating material may be either water-based or solvent-based for offline coating, but is preferably water-based for in-line coating.
  • Average particle diameter (d50) The average particle size d50 was defined as the particle size having an integrated volume fraction of 50% in an equivalent spherical distribution measured using a centrifugal sedimentation type particle size distribution analyzer (SA-CP3 type) manufactured by Shimadzu Corporation.
  • Measurement of transparency of film Measurements were made in accordance with ASTM D1746 using a transparency measuring instrument (TM-1D 2-digit type after decimal point: light source wavelength 546 ⁇ 5 nm) manufactured by Murakami Color Research Laboratory.
  • Measurement of film haze Measurement was performed according to JIS K7136 using a haze meter (HZ-2) manufactured by Suga Test Instruments.
  • Measurement of internal haze of film Measurement was performed using a haze meter (HZ-2) manufactured by Suga Test Instruments. The measurement was performed using ethanol as a rough surface compensation solvent. That is, it measured by setting a film in a glass cell and immersing in ethanol.
  • HZ-2 haze meter
  • Ra film surface roughness
  • Evaluation of scratch resistance The number of scratches on the produced film surface was counted, and the difficulty of scratching was evaluated. Evaluation was performed using an A4 size film. ⁇ Criteria> (It is hard to be scratched) ⁇ > ⁇ > ⁇ (It is easy to be scratched) ⁇ : Scratch occurrence frequency is 3 or less ⁇ : Scratch occurrence frequency is 5 or less ⁇ : Scratch occurrence frequency is 5 or more In the above criteria, ⁇ or more is a level that can be used without any problem in actual use.
  • Examples 1 to 4 and Comparative Examples 1 to 7 ⁇ Manufacture of polyester (A)> Starting from 100% by weight of dimethyl terephthalate and 60% by weight of ethylene glycol, magnesium acetate tetrahydrate is added as a catalyst to the reactor, the reaction start temperature is 150 ° C., and the reaction temperature is gradually increased as methanol is distilled off. The temperature was raised to 230 ° C. after 3 hours. After 4 hours, the transesterification reaction was substantially terminated. Ethyl acid phosphate was added to the reaction mixture, which was then transferred to a polycondensation tank, and 0.04 part of antimony trioxide was added to carry out a polycondensation reaction for 4 hours.
  • the temperature was gradually raised from 230 ° C. to 280 ° C.
  • the pressure was gradually reduced from normal pressure, and finally 0.3 mmHg.
  • the reaction was stopped at a time corresponding to an intrinsic viscosity of 0.64 dL / g due to a change in the stirring power of the reaction vessel, and the polymer was discharged under nitrogen pressure to obtain a polyester chip (A).
  • the intrinsic viscosity of this polyester was 0.64 dL / g.
  • polyester (B1 to B4) ⁇ Production of polyester (B1 to B4)>
  • the content of ethylene glycol slurry of divinylbenzene / methyl methacrylate copolymer crosslinked particles having different average particle diameters is 0.5% by weight with respect to polyester.
  • Polyesters (B1 to B4) were obtained using the same method as the production method of the polyester (A) except that it was added as described above.
  • the production method of divinylbenzene / methyl methacrylate copolymer crosslinked particles is as follows.
  • a homogeneous solution of 100 parts of methyl methacrylate, 25 parts of divinylbenzene, 22 parts of ethylvinylbenzene, 1 part of benzoyl peroxide and 100 parts of toluene is dispersed in 700 parts of water, and then stirred at 80 ° C. for 6 hours in a nitrogen atmosphere. Polymerization was carried out while heating. The average particle diameter of the obtained crosslinked polymer granules having ester groups was about 0.1 mm. The produced polymer was washed with demineralized water and extracted twice with 500 parts of toluene to remove a small amount of unreacted monomer linear polymer.
  • the crosslinked polymer particles are pulverized with an attritor and a sand grinder to obtain divinylbenzene / methyl methacrylate copolymer having average particle diameters of 0.8, 1.4, 2.3, and 4.4 ⁇ m having different particle diameters.
  • Polymerized crosslinked particles were obtained.
  • B1 is a polyester chip containing particles having a particle diameter of 0.8 ⁇ m
  • B2 is a chip containing particles of 1.4 ⁇ m
  • B3 is a chip containing particles of 2.3 ⁇ m
  • B4 is a chip containing particles of 4.4 ⁇ m. It was.
  • the obtained polyester chips (B1 to B4) all had an intrinsic viscosity of 0.62 dL / g.
  • polyester (C) ⁇ Manufacture of polyester (C)>
  • the same method as the method for producing polyester (B), except that the additive particles are silica particles having an average particle diameter of 2.7 ⁇ m and the content with respect to the polyester is 0.3% by weight. was used to obtain a polyester (D).
  • the obtained polyester (D) had an intrinsic viscosity of 0.61 dL / g.
  • polyester (D) ⁇ Manufacture of polyester (D)>
  • the additive particles are the same as the production method of the polyester (B) except that silica particles having an average particle diameter of 3.2 ⁇ m and the content with respect to the polyester are 0.6% by weight.
  • Polyester (D) was obtained using the method. The average particle size was determined by a laser method. The obtained polyester (D) had an intrinsic viscosity of 0.62 dL / g.
  • a mixed raw material obtained by mixing the polyester (A) chip and the polyester (B), (C), and (D) chips in the proportions shown in Table 1 is used as a raw material for the outermost layer (surface layer) and the intermediate layer.
  • Each was supplied to an extruder, melt-extruded at 280 ° C., and then cooled and solidified on a cooling roll having a surface temperature set to 30 ° C. using an electrostatic application adhesion method to obtain an unstretched sheet.
  • the film was stretched 3.5 times in the longitudinal direction at 85 ° C., and then subjected to a preheating step in the tenter and 4.3 times transverse stretching at 105 ° C., followed by heat treatment at 235 ° C. for 10 seconds, Each 250 mm polyester film was obtained.
  • the total thickness of the obtained film was 50 ⁇ m, and the thickness of each layer was 2.5 ⁇ m / 45 ⁇ m / 2.5 ⁇ m.
  • the optical polyester film of the present invention can be suitably used, for example, as a base film for a transparent conductive film of a touch panel display member.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
  • Manufacture Of Macromolecular Shaped Articles (AREA)

Abstract

Cette invention concerne un film polyester utile pour des applications optiques, doué d'une excellente clarté quand il est utilisé comme film de base pour film conducteur transparent, par exemple, comme film de base pour un élément d'affichage tel qu'un écran tactile. Le film polyester pour application optique selon l'invention prévient les défauts optiques par inhibition de l'adhérence de poussière et autre, et manifeste une excellente transparence et définition. Le film polyester pour application optique ci-décrit a une surface qui n'est pas sujette aux rayures, tout en offrant une excellente maniabilité et productivité. Il offre un degré de transparence de 83,5 % ou plus (ou un degré de transparence interne de 96,5 % ou plus), et une surface du film a une rugosité (Ra) de 9,0 nm ou plus.
PCT/JP2011/079374 2010-12-25 2011-12-19 Film polyester pour application optique Ceased WO2012086592A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP2010-288980 2010-12-25
JP2010288980 2010-12-25
JP2011-026005 2011-02-09
JP2011026005 2011-02-09

Publications (1)

Publication Number Publication Date
WO2012086592A1 true WO2012086592A1 (fr) 2012-06-28

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PCT/JP2011/079374 Ceased WO2012086592A1 (fr) 2010-12-25 2011-12-19 Film polyester pour application optique

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WO (1) WO2012086592A1 (fr)

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003048289A (ja) * 2001-08-07 2003-02-18 Mitsubishi Polyester Film Copp 二軸配向積層ポリエステルフィルム
JP2004250624A (ja) * 2003-02-21 2004-09-09 Teijin Dupont Films Japan Ltd 透明ポリエステルフィルム
JP2005041917A (ja) * 2003-07-23 2005-02-17 Toray Ind Inc プラスチックフィルムおよびその製造方法
JP2008239743A (ja) * 2007-03-27 2008-10-09 Toray Ind Inc ドライフィルムレジスト支持体用ポリエステルフィルム
JP2009214360A (ja) * 2008-03-09 2009-09-24 Mitsubishi Plastics Inc 光学用積層ポリエステルフィルム
JP2011148201A (ja) * 2010-01-22 2011-08-04 Toyobo Co Ltd 偏光板離型用二軸延伸ポリエチレンテレフタレートフィルム

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003048289A (ja) * 2001-08-07 2003-02-18 Mitsubishi Polyester Film Copp 二軸配向積層ポリエステルフィルム
JP2004250624A (ja) * 2003-02-21 2004-09-09 Teijin Dupont Films Japan Ltd 透明ポリエステルフィルム
JP2005041917A (ja) * 2003-07-23 2005-02-17 Toray Ind Inc プラスチックフィルムおよびその製造方法
JP2008239743A (ja) * 2007-03-27 2008-10-09 Toray Ind Inc ドライフィルムレジスト支持体用ポリエステルフィルム
JP2009214360A (ja) * 2008-03-09 2009-09-24 Mitsubishi Plastics Inc 光学用積層ポリエステルフィルム
JP2011148201A (ja) * 2010-01-22 2011-08-04 Toyobo Co Ltd 偏光板離型用二軸延伸ポリエチレンテレフタレートフィルム

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