WO2019082834A1 - Polyester film to be used as surface protection film of flexible display - Google Patents

Polyester film to be used as surface protection film of flexible display

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Publication number
WO2019082834A1
WO2019082834A1 PCT/JP2018/039147 JP2018039147W WO2019082834A1 WO 2019082834 A1 WO2019082834 A1 WO 2019082834A1 JP 2018039147 W JP2018039147 W JP 2018039147W WO 2019082834 A1 WO2019082834 A1 WO 2019082834A1
Authority
WO
WIPO (PCT)
Prior art keywords
film
polyester film
polyester
hard coat
flexible display
Prior art date
Application number
PCT/JP2018/039147
Other languages
French (fr)
Japanese (ja)
Inventor
有記 本郷
正太郎 西尾
Original Assignee
東洋紡株式会社
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 東洋紡株式会社 filed Critical 東洋紡株式会社
Priority to JP2018560045A priority Critical patent/JP7144744B2/en
Publication of WO2019082834A1 publication Critical patent/WO2019082834A1/en
Priority to JP2022136019A priority patent/JP7334837B2/en

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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
    • 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
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/36—Layered products comprising a layer of synthetic resin comprising polyesters
    • 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

Definitions

  • the present invention relates to a polyester film, and more particularly to a polyester film capable of obtaining high pencil hardness when a hard coat layer or the like is laminated.
  • Thin-film and lightweight mobile terminal devices such as displays and smartphones are in progress.
  • tempered glass is generally used to protect the display body, since all use rigid housings.
  • displays that emphasize design are preferred.
  • specially shaped displays such as circular are preferred.
  • a flexible display intended for display installation on a curved surface is required.
  • Patent Document 1 proposes a material with high hardness and flexibility as a hard coat material.
  • the material is expensive and there is a problem with versatility, and there is also a problem that the surface has a low scratch resistance.
  • Patent Document 2 a transparent polyimide material that can achieve high pencil hardness independently of the hard coat material has also been proposed.
  • this material is very expensive and has problems with mass productivity.
  • the present invention is intended to solve the problem of the transparent film as described above, and is to provide a polyester film having a high pencil hardness when the hard coat layer is laminated at low cost.
  • the present invention has the following constitution.
  • a flexible display having a limiting viscosity of 0.60 to 1.0 dL / g and having a crystallinity of 48% or more by density method and a crystallinity of 1.20 or more of the polyester film surface by ATR method Polyester film for surface protection film.
  • the polyester film for a surface protection film of a flexible display as described in the first above having a thickness of 25 to 188 ⁇ m.
  • the polyester film for surface protection films of the said flexible display as described in said 1st or 2nd which is a biaxially stretched polyester film and which has an easily bonding layer in at least one surface of the said biaxially stretched polyester film. 4.
  • the surface hardness becomes higher than that of a general polyester film, and the hard coat film is used as a surface protective film of a display body to scratch the display surface. It is possible to provide a display body that is resistant to impact, deformation, etc. and is excellent in design. The display can provide a beautiful image.
  • the display referred to in the present invention generally refers to a display device, and the types of display include LCD, organic EL display, inorganic EL display, LED, FED, etc., but it has a foldable structure. LCD, organic EL and inorganic EL are preferable. In particular, the layer structure is reduced, and a wide color gamut organic EL is more preferable.
  • the form of the display includes a large screen, a display, digital signage, a bendable portable terminal, a personal computer and the like, and can be used without limitation.
  • a display with a touch panel having a touch panel function to be operated by direct touch, digital signage, a bending portable terminal, a personal computer, and the like.
  • a display body it is especially preferable that it is the following flexible displays.
  • the flexible display is a structure in which one continuous display can be bent according to the application, and at the same time, it is desirable that the display be thin and lightweight.
  • a foldable type display such as a foldable type display and a rollable type display such as a rollable type display
  • those usable for paper-like may be mentioned.
  • Polyester film Transparent films include films with high light transmittance such as polyimide film, polyester film, polycarbonate film, acrylic film, triacetyl cellulose film, cycloolefin polymer film and low haze, among which high impact resistance and appropriate Polyester films having pencil hardness are preferred, and polyethylene terephthalate films which can be produced inexpensively are particularly preferred.
  • the polyester film may be a film having a single layer structure consisting of one or more polyester resins, or when two or more polyesters are used, a multilayer structure film may be used, or a super multilayer laminated film having a repeated structure may be used. .
  • polyester resin examples include polyester films made of polyethylene terephthalate, polybutylene terephthalate, polyethylene-2,6-naphthalate, or a copolymer containing a constituent component of these resins as a main component.
  • polyester films made of polyethylene terephthalate, polybutylene terephthalate, polyethylene-2,6-naphthalate, or a copolymer containing a constituent component of these resins as a main component.
  • a biaxially stretched polyester film is preferable, and a biaxially stretched polyethylene terephthalate film is particularly preferable.
  • examples of the dicarboxylic acid component of the polyester include aliphatic dicarboxylic acids such as adipic acid and sebacic acid; terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid Aromatic dicarboxylic acids such as acids; and polyfunctional carboxylic acids such as trimellitic acid and pyromellitic acid.
  • glycol component for example, fatty acid glycols such as ethylene glycol, diethylene glycol, 1,4-butanediol, propylene glycol, neopentyl glycol and the like; aromatic glycols such as p-xylene glycol; 1,4-cyclohexanedimethanol and the like Alicyclic glycols; polyethylene glycol having an average molecular weight of 150 to 20,000.
  • the mass ratio of the copolymer component of the preferable copolymer is less than 20% by mass. In the case of less than 20% by mass, film strength, transparency and heat resistance are preferably maintained.
  • the intrinsic viscosity of at least one resin pellet is preferably in the range of 0.60 to 1.0 dl / g.
  • the pencil hardness after hard coating is preferably improved. More preferably, it is 0.65 dl / g or more, particularly preferably 0.70 dl / g or more.
  • the intrinsic viscosity is 1.00 dl / g or less, it is preferable that the film production can be stably operated stably without the increase in filtration pressure of the molten fluid becoming too large.
  • the intrinsic viscosity of the film is 0.60 dl / g or more regardless of whether the film has a single-layer structure or a laminated structure.
  • the increase in molecular weight of the polyester resin is preferable because the elastic behavior of the film is improved, and deformation can be effectively suppressed with respect to the load of the pencil at the time of pencil hardness measurement. More preferably, it is 0.65 dl / g or more, particularly preferably 0.70 dl / g or more.
  • the pencil hardness is also improved by the increase in the intrinsic viscosity, there is a concern that the productivity may be lowered. Therefore, the intrinsic viscosity of 1.00 dl / g or less is preferable because it can be produced with good operability.
  • the thickness of the polyester film is preferably 25 to 188 ⁇ m, and more preferably 25 to 125 ⁇ m.
  • the thickness is 25 ⁇ m or more, the handling property and the impact resistance are preferably improved, and when the thickness is 188 ⁇ m or less, it is advantageous for reducing the weight, and it is preferably excellent in flexibility and processability.
  • the surface of the polyester film of the present invention may be smooth or have asperities, but since it is used for a protective film application on the surface of a display, it is not preferable to reduce the optical characteristics derived from asperities.
  • the haze is preferably 3% or less, more preferably 2% or less, and most preferably 1% or less. If the haze is 3% or less, the visibility of the image can be improved.
  • the lower limit of the haze is preferably as small as possible, but may be 0.1% or more, and may be 0.3% or more.
  • the polyester resin of the surface layer is a method for forming the unevenness to give a moderate slipperiness from the viewpoint of handling.
  • the layer can be formed by blending a filler or coating a filler-containing coat layer during film formation.
  • a well-known method is employable as a method of mix
  • it can be added at any stage of producing polyester, it is preferably added as a slurry dispersed in ethylene glycol or the like at the stage of esterification or after completion of transesterification and before the start of polycondensation reaction. And the polycondensation reaction may proceed.
  • the filtered product is used as the remainder of the polyester raw material before the esterification reaction, during the esterification reaction or after the esterification reaction.
  • the method of adding is preferable. According to this method, since the monomer liquid has a low viscosity, uniform dispersion of particles and high-precision filtration of the slurry can be easily performed, and the dispersibility of the particles is good when added to the remaining portion of the raw material. Aggregates are also less likely to occur. From such a point of view, it is particularly preferable to add to the balance of the raw material in the low temperature state before the esterification reaction.
  • the number of projections on the film surface can be further reduced by a method (master batch method) in which the pellets and the pellets containing no particles are kneaded and extruded.
  • the polyester film may contain various additives within the range which maintains the preferable range of the total light transmittance.
  • an additive an antistatic agent, a UV absorber, and a stabilizer are mentioned, for example.
  • the total light transmittance of the polyester film is preferably 85% or more, and more preferably 87% or more. If the transmittance is 85% or more, sufficient visibility can be ensured. The higher the total light transmittance of the polyester film, the better, but it may be 99% or less, or 97% or less.
  • the surface of the polyester film of the present invention can be treated to improve the adhesion to the resin forming the hard coat layer and the like.
  • unevenness treatment such as sand blasting treatment, solvent treatment, corona discharge treatment, electron beam irradiation treatment, plasma treatment, ozone / ultraviolet radiation treatment, flame treatment, chromic acid treatment, hot air treatment etc.
  • An oxidation treatment etc. are mentioned and it can use without limitation in particular.
  • the adhesion can also be improved by an adhesion improving layer such as an easy adhesion layer.
  • the easily adhesive layer can be used without particular limitation, such as acrylic resin, polyester resin, polyurethane resin, polyether resin, etc., and can be formed by a general coating method, preferably a so-called in-line coating formulation.
  • the above-mentioned polyester film is obtained, for example, by uniformly dispersing inorganic particles in a monomer liquid which is a part of the polyester raw material and filtering it, and then adding it to the remainder of the polyester raw material to carry out polymerization of the polyester. It can melt-extrude to a sheet form through a filter, and after cooling, it extends
  • PET polyethylene terephthalate
  • the number of layers is not limited, such as a single layer structure or a multilayer structure.
  • Pellets of PET are mixed and dried at a predetermined ratio, and then fed to a known melt-layering extruder, extruded from a slit die into a sheet, cooled and solidified on a casting roll to form an unstretched film .
  • a known melt-layering extruder extruded from a slit die into a sheet, cooled and solidified on a casting roll to form an unstretched film .
  • a single layer it may be a single extruder, but in the case of producing a film having a multilayer structure, two or more extruders, two or more manifolds or merging blocks (for example, merging with square junctions)
  • a plurality of film layers constituting each outermost layer can be laminated using a block), and a sheet of two or more layers can be extruded from a die and cooled with a casting roll to form an unstretched film.
  • high precision filtration is preferably performed at any place where the molten resin is maintained at about 280 ° C., in order to remove foreign matter contained in the resin.
  • the filter medium used for high-precision filtration of the molten resin is not particularly limited, but the filter medium of the stainless sintered body is excellent in the removal performance of aggregates mainly composed of Si, Ti, Sb, Ge, and Cu and high melting point organic substances Because it is preferable.
  • the filter particle size (initial filtration efficiency 95%) of the filter medium is preferably 20 ⁇ m or less, and particularly preferably 15 ⁇ m or less.
  • the filtration particle size (initial filtration efficiency 95%) of the filter medium exceeds 20 ⁇ m, foreign matter having a size of 20 ⁇ m or more can not be sufficiently removed.
  • High-precision filtration of a molten resin using a filter medium with a filter particle size (initial filtration efficiency 95%) of 20 ⁇ m or less may reduce the productivity, but a film with few protrusions due to coarse particles is obtained. Preferred above.
  • pellets of PET are sufficiently vacuum dried and then supplied to an extruder, melt extruded into a sheet at about 280 ° C., and solidified by cooling to form an unstretched PET sheet.
  • the obtained unstretched sheet is stretched 2.5 to 5.0 times in the longitudinal direction with a roll heated to 80 to 120 ° C. to obtain a uniaxially oriented PET film.
  • the end of the film is gripped by a clip, led to a hot air zone heated to 80 to 180 ° C., and after drying, it is stretched by 2.5 to 5.0 times in the width direction.
  • a heat treatment zone at 160 to 250 ° C., and heat treatment is performed for 1 to 60 seconds to complete crystal orientation.
  • 1 to 12% relaxation treatment may be performed in the width direction or the longitudinal direction, as needed.
  • the degree of crystallinity is mainly determined by the amount of heat applied to the film in the heat treatment zone.
  • the amount of heat is determined by various conditions such as film forming equipment conditions, film forming speed, film thickness, etc., so the degree of crystallization is not determined only by the heat treatment temperature, but the heat treatment temperature is preferably 160 to 250 ° C. It may be said that 240 ° C. is more preferable.
  • the temperature is preferably 160 to 250 ° C. or higher because it can suppress a decrease in crystallization due to remelting of the polyester.
  • the crystallinity of the film by the density method is 48% or more, and the crystallinity of the film surface by the ATR method is 1.20 or more .
  • the crystallinity of the polyester film by the density method is preferably 48% or more, more preferably 50% or more, and still more preferably 52% or more.
  • the degree of crystallinity is preferably high, but the upper limit of the film that can be produced is about 65%.
  • the crystallinity of the film surface according to the ATR method is preferably 1.20 or more, more preferably 1.25 or more, and still more preferably 1.27 or more.
  • the crystallinity of the film surface by the ATR method is also preferably high, but the upper limit of the film that can be produced is about 3.0.
  • the easy-adhesion layer can be obtained by applying the coating solution on one side or both sides of a uniaxially stretched film not stretched or in the longitudinal direction, then drying at 100 to 150 ° C., and stretching it in one direction or two directions. .
  • the final coating amount of the easy adhesion layer is preferably controlled to 0.05 to 0.20 g / m 2 . Adhesiveness is satisfy
  • resin used for an easily bonding layer it is possible to use without particular limitation, for example, polyester resin, polyurethane resin, polyester polyurethane resin, polycarbonate polyurethane resin, acrylic resin and the like.
  • a crosslinking agent of an easily bonding layer crosslinking agents, such as melamine type, an isocyanate type, an oxazoline type, an epoxy type, are mentioned. Two or more kinds can be mixed and used. These are preferably coated with a water-based coating solution in view of the properties of the in-line coating, and the above-mentioned resin and crosslinking agent are preferably water-soluble or water-dispersible resins and compounds.
  • the average particle diameter of the fine particles is preferably 2 ⁇ m or less. When the average particle diameter of the particles exceeds 2 ⁇ m, the particles are easily detached from the easily adhesive layer.
  • the particles to be contained in the easy adhesion layer include, for example, titanium oxide, barium sulfate, calcium carbonate, calcium sulfate, silica, alumina, talc, kaolin, clay, calcium phosphate, mica, hectorite, zirconia, tungsten oxide, lithium fluoride, Examples thereof include inorganic particles such as calcium fluoride, and organic polymer particles such as styrene type, acrylic type, melamine type, benzoguanamine type and silicone type particles. These may be added alone to the easily bonding layer, or two or more may be added in combination.
  • the well-known method can be used similarly to said application layer.
  • reverse roll coating method gravure coating method, kiss coating method, roll brush method, spray coating method, air knife coating method, wire bar coating method, pipe doctor method, etc.
  • these methods may be used alone. Or it can carry out in combination.
  • (meth) acrylic acid ester, siloxane type, inorganic hybrid type, urethane acrylate type, polyester acrylate type, epoxy type and the like can be used without particular limitation.
  • two or more types of materials can be mixed and used, and particles, such as an inorganic filler and an organic filler, can also be added.
  • (meth) acrylic acid esters and acrylate resins are preferable, and resins having three or more reactive groups in the molecule as an essential component are preferable.
  • resins having three or more reactive groups examples include tris (2-acryloyloxyethyl) isocyanurate, tris (3-acryloyloxypropyl) isocyanurate, tris (2-methacryloyloxyethyl) isocyanurate, and tris (3- (3-acryloyloxyethyl) isocyanurate.
  • Tris [(meth) acryloyloxyalkyl] isocyanurate such as methacryloyloxypropyl) isocyanurate, and further trimethylolpropane tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, propionic acid modified dipentaerythritol tri (meth) Acrylate, pentaerythritol tri (meth) acrylate, propylene oxide modified trimethylolpropane tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, propionic acid modified dipen Erythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, (meth) acrylates such as caprolactone-modified dipentaerythritol hexa (meth) acrylate.
  • One of these may be used alone, or
  • hard coating agents can also be used.
  • beam set (registered trademark) series manufactured by Arakawa Chemical Industries, Aika Intron (registered trademark) series manufactured by Aika Industries, Lioduras (registered trademark) series manufactured by Toyo Ink Co., Ltd., etc. can be used without particular limitation.
  • It can also be used by mixing it with acrylic acid ester compounds.
  • photopolymerization initiator When the hard coat layer of the present invention is cured using ultraviolet light, it is necessary to add a photopolymerization initiator.
  • the photopolymerization initiator include benzophenone, acetophenone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, methyl benzoin benzoate, benzoin dimethyl ketal, 2,4 -Diethylthioxanthone, 1-hydroxycyclohexyl phenyl ketone, benzyl diphenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, benzyl, dibenzyl, diacetyl, ⁇ -chloro anthraquinone, (2,4,6-trimethyl And benzyl diphenyl) phosphin
  • 2-hydroxy-1- ⁇ 4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] -phenyl ⁇ -2-methylpropan-1-one which is considered to be excellent in surface curability.
  • 1-hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1 -One is preferred, among which 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 2-methyl-1- [4 Particular preference is given to-(methylthio) phenyl] -2-morpholinopropan-1-one. These may be used alone or in combination of two or more.
  • the addition amount of the photopolymerization initiator is not particularly limited. For example, it is preferable to use about 1 to 10% by mass with respect to the resin to be used. Sufficient curability can be obtained by adding 1% by mass or more, and by setting the content to 10% by mass or less, the content ratio of the resin having three or more reactive groups is high, and a hard coat film having high crosslinking density and high hardness Can be
  • the thickness of the hard coat layer is preferably 1 to 40 ⁇ m. If it is thicker than 1 ⁇ m, it is sufficiently cured to obtain good pencil hardness. In addition, by setting the thickness to 40 ⁇ m or less, curling due to curing shrinkage of the hard coat can be suppressed, and the handling property of the film can be improved.
  • a coating method of a hard-coat layer it can be used without particular limitation, such as a Mayer bar, a gravure coat, a die coater, a knife coater, etc. It can select suitably according to a viscosity and a film thickness.
  • the drying temperature is preferably 60 to 100 ° C., and more preferably 60 to 90 ° C. If it is 60 ° C. or more, it can be sufficiently dried in a short time, and if it is 100 ° C. or less, deformation of the polyester film does not occur, which is preferable.
  • UV rays and electron beams As a method of curing the hard coat layer, energy rays such as ultraviolet rays and electron beams, and a method of curing by heat can be used, but ultraviolet rays and electron beams are preferable in order to reduce damage to the film.
  • UV There are a high pressure mercury lamp, an electrodeless lamp, etc. as an ultraviolet lamp, but it can be used by selecting suitably.
  • the integrated light quantity of ultraviolet light is preferably 50 to 500 mJ / cm 2, and more preferably 100 to 200 mJ / cm 2 .
  • Sufficient pencil hardness can be obtained by irradiating the integrated light amount of 50 mJ / cm 2 or more, and the processing speed can be increased if the integrated light amount is 500 mJ / cm 2 or less, which is preferable because the economic efficiency is improved.
  • the curability can also be improved by irradiation with ultraviolet light in an inert gas such as nitrogen, argon or carbon dioxide, which can be appropriately selected.
  • the electron beam irradiation apparatus is an area type, a scanning type, etc., but can be appropriately selected and used.
  • the integrated irradiation dose of the electron beam is preferably 25 to 500 kGy, more preferably 50 to 300 kGy. Sufficient pencil hardness can be obtained by irradiating an accumulated irradiation dose of 25 kGy or more, and if it is 500 kGy or less, the processing speed can be increased, which is preferable because economic efficiency is improved.
  • Irradiation is preferably performed at an oxygen concentration of 500 ppm or less in an inert gas such as nitrogen or argon. By setting the oxygen concentration to 500 ppm or less, the generation of ozone can be suppressed, and the safety during operation can be improved.
  • the pencil hardness of the hard coat layer is preferably 2H or more, more preferably 3H or more, and particularly preferably 4H or more. If the pencil hardness is 2H or more, it does not easily deform and does not reduce the visibility. Generally, the pencil hardness of the hard coat layer is preferably high, but it may be 10 H or less, 8 H or less, or 6 H or less, which can be used practically without problems.
  • the hard coat layer in the present invention may be one to which another function is added as long as it can be used for the purpose of protecting the display by increasing the pencil hardness of the surface as described above.
  • a hard coat layer to which functions such as an antiglare layer having a certain pencil hardness as described above, an antiglare antireflection layer, an antireflection layer, a low reflection layer, and an antistatic layer are added is also included. Is preferably applied.
  • the density of the film sample was measured at three points, and the average value was defined as the crystallinity degree.
  • the resin component is a mixture of completely amorphous and completely crystalline, and the density is as described later, and the density of the sample is a value obtained by dividing the sum of the mass of each component constituting the sample by the sum of the volumes of each component.
  • the crystallinity (weight ratio) of each resin was estimated based on the assumption that The sample density was measured according to the method according to JIS K-7112-1980 (density gradient tube method). The calculation formula of the degree of crystallinity is as follows, and the density of each component alone was as follows (unit: g / cm 3 ).
  • Crystallinity (%) ⁇ dc (d-da) / d (dc-da) ⁇ ⁇ 100
  • dc density of completely crystalline portion
  • da density of completely amorphous portion
  • Density of complete crystal part (dc) 1.46
  • density of completely crystalline part (dc) 1.41
  • ATR method Perform total reflection infrared absorption measurement (FT-IRATR measurement) on one side of the stretched film (non-corona treated side if any one side of the film is corona treated) under the following conditions, and absorption appears near 1340 cm -1, was calculated crystallinity by the intensity ratio of absorption appears near 1410cm -1 (1340cm -1 / 1410cm -1 ).
  • 1340 cm -1 is absorption due to bending vibration of CH 2 (trans structure) of ethylene glycol
  • 1410 cm -1 is absorption unrelated to crystal and orientation.
  • FT-IR device "FTS-60A / 896" manufactured by Bio RadDIGILAB
  • One time reflection ATR attachment SPECAC "golden gate MKII”
  • Internal reflection element diamond Incident angle: 45 ° Resolution: 4 cm -1 Integration count: 128 times
  • Pencil Hardness According to JIS K 5600-5-4: 1999, it was measured at a load of 750 g and a speed of 1.0 mm / s to visually confirm the presence or absence of deformation. It was OK if there was no deformation. It measured 5 times, and evaluation of OK made 4 or more times pencil hardness the measurement value.
  • reaction solution reached a predetermined amine equivalent.
  • this reaction solution was cooled to 40 ° C., and then 9.03 parts by mass of triethylamine was added to obtain a polyurethane prepolymer D solution.
  • 450 g of water was added to a reaction vessel equipped with a high-speed stirable homodisper, adjusted to 25 ° C., and while stirring and mixing, an isocyanate group-terminated prepolymer was added and dispersed in water. Thereafter, a water-soluble polyurethane resin (A) having a solid content of 35% by mass was prepared by removing a part of acetonitrile and water under reduced pressure.
  • the following coating agents 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 sol with an average particle diameter of 40 nm, solid content Concentration 40% by mass)
  • Surfactant 0.05 parts by mass (Silicone-based, solid content concentration 100% by mass)
  • the reaction product in the first esterification reaction vessel is continuously taken out of the system, supplied to the second esterification reaction vessel, and evaporated from the first esterification reaction vessel in the second esterification reaction vessel.
  • the EG solution containing 8% by mass of EG to the produced polymer (produced PET) and further containing Mg acetate in an amount of 65 ppm to the produced PET, and 20 ppm of P atoms to the produced PET The EG solution containing the amount of TMPA was added and allowed to react at 260.degree. C. under normal pressure for an average residence time of 1.5 hours.
  • the reaction product in the second esterification reaction vessel is continuously taken out of the system and supplied to the third esterification reaction vessel, and further contains TMPA in an amount of 20 ppm of P atom based on the produced PET
  • the EG solution was added and reacted at 260 ° C. under normal pressure for an average residence time of 0.5 hours.
  • the esterification reaction product produced in the third esterification reaction vessel is continuously supplied to a three-stage continuous polycondensation reaction apparatus to carry out polycondensation, and a filter material of a stainless sintered body (nominal filtration accuracy of 5 ⁇ m) The particles were filtered through 90% of particles to obtain polyethylene terephthalate pellets (a) having an intrinsic viscosity of 0.58 dl / g.
  • polyethylene terephthalate pellets (d) Preparation of polyethylene terephthalate pellets (d)
  • the polyethylene terephthalate pellet (a) is subjected to solid-phase polymerization using a rotary vacuum polymerization apparatus under reduced pressure of 0.5 mmHg at 220 ° C. while changing the time from (c) to a limiting viscosity of 0.75 dL / g.
  • Polyethylene terephthalate pellets (d) were produced.
  • Examples 1 to 5 and Comparative Examples 1 to 3 The above polyethylene terephthalate pellets (c) were dried under reduced pressure (3 Torr) at 180 ° C. for 8 hours, and then the pellets (a) of polyethylene terephthalate were respectively fed to the extruder and melted at 285 ° C.
  • This polymer is filtered with a filter material of a stainless steel sintered body (nominal filtration accuracy 10 ⁇ m particles 95% cut), extruded into a sheet form from a die and extruded, and then cast onto a casting drum with a surface temperature of 30 ° C. using electrostatic application casting. The film was brought into contact and solidified by cooling to form an unstretched film.
  • This unstretched film was stretched 3.4 times at 85 ° C. in the longitudinal direction.
  • the above easy-adhesion layer coating solution was applied to one side of a PET film by roll coating, and then dried at 80 ° C. for 20 seconds. In addition, it adjusted so that the application amount after drying of the last (after biaxial stretching) might be set to 0.06 g / m ⁇ 2 >.
  • This uniaxially stretched film was stretched 4.2 times at 95 ° C. in the width direction using a tenter, and heat-treated at 235 ° C. for 5 seconds to obtain the polyethylene terephthalate film of Example 1 in Table 1.
  • Example 1-1 The hard coat coating solution 10 is coated on the easily adhesive layer of the polyethylene terephthalate film obtained in Example 1 using a Mayer bar so that the film thickness after drying is 5.0 ⁇ m, and dried at 80 ° C. for 1 minute. Then, it was irradiated with ultraviolet light (integrated light amount: 200 mJ / cm 2 ) to obtain a hard coat film.
  • ultraviolet light integrated light amount: 200 mJ / cm 2
  • Examples 1-1 to 5-1, 1-2, and 2-2 and comparative examples 1-1 to 3-1) A hard coat film was produced in the same manner as in Example 1-1, using the conditions described in Table 2.
  • the produced hard coat film was bonded to the organic EL module through a 25 ⁇ m-thick adhesive layer to produce a flexible display.
  • the organic EL module could be protected from external impact, and good visibility could be obtained.
  • the polyester film which surface hardness becomes high when laminating a hard-coat layer etc. can be provided, and the hard-coat film which laminated the hard-coat layer on the surface of the polyester film of this invention
  • a surface protective film of the body By being used as a surface protective film of the body, it has become possible to provide a display body which is resistant to scratches, impacts, deformation, etc. on the surface of the display body and is also excellent in design.

Abstract

[Problem] To provide a low-cost polyester film which has a high pencil hardness when a hard coat layer is laminated. [Solution] This polyester film is to be used as a surface protection film of a flexible display, and has an intrinsic viscosity of 0.60-1.0 dL/g, a degree of crystallinity of 48% or more as measured by a density method, and a degree of crystallinity of 1.20 or more at the surface of the polyester film as measured by an ATR method. Also, provided are a hard coat film and display body using the polyester film.

Description

フレキシブルディスプレイの表面保護フィルム用ポリエステルフィルムPolyester film for surface protection film of flexible display
　本発明はポリエステルフィルムに関し、ハードコート層などを積層した場合に高い鉛筆硬度が得られるポリエステルフィルムに関する。 The present invention relates to a polyester film, and more particularly to a polyester film capable of obtaining high pencil hardness when a hard coat layer or the like is laminated.
　ディスプレイやスマートフォンなどの携帯端末機器は薄膜軽量化が進んでいる。現在、いずれもリジッドな筺体を使用しているため、表示体の保護には一般に強化ガラスが用いられている。一方、近年ではデザインを重視したディスプレイが好まれている。例えば、円形などの特殊な形状のディスプレイが好まれる。特に近年では、曲面へのディスプレイ設置を目的とした屈曲性のディスプレイが求められている。 Thin-film and lightweight mobile terminal devices such as displays and smartphones are in progress. At present, tempered glass is generally used to protect the display body, since all use rigid housings. On the other hand, in recent years, displays that emphasize design are preferred. For example, specially shaped displays such as circular are preferred. In particular, in recent years, a flexible display intended for display installation on a curved surface is required.
　しかしながら、屈曲性のあるディスプレイではガラス素材を用いることができないため、アクリル板などが用いられてきたが、薄膜のアクリル板は傷や衝撃性に弱い問題があった。また、衝撃性に強く耐光性の高いポリカーボネートが用いられることもあるが、高価であり、鉛筆硬度が弱いとの問題があった。一方、ポリエステルフィルムは、安価で、耐衝撃性に優れる一方、鉛筆硬度が不十分との問題があった。 However, although an acrylic plate or the like has been used because a glass material can not be used in a flexible display, a thin film acrylic plate has a problem of being weak in scratches and impact. In addition, although polycarbonate having high impact resistance and high light resistance may be used in some cases, it is expensive and has a problem that the pencil hardness is weak. On the other hand, polyester films are inexpensive and have excellent impact resistance, but have a problem that the pencil hardness is insufficient.
　これらを達成するため、特許文献１ではハードコート材料として、高硬度で屈曲性のある素材を提案している。しかしながら、素材が高価であり汎用性に問題がある他、表面の耐擦傷性が低いとの問題もある。 In order to achieve these, Patent Document 1 proposes a material with high hardness and flexibility as a hard coat material. However, the material is expensive and there is a problem with versatility, and there is also a problem that the surface has a low scratch resistance.
　また、特許文献２のように、ハードコート材料に依存せず高い鉛筆硬度を実現できる透明なポリイミド材料も提案されている。しかしながら、この材料は非常に高価であり量産性に問題がある。 In addition, as disclosed in Patent Document 2, a transparent polyimide material that can achieve high pencil hardness independently of the hard coat material has also been proposed. However, this material is very expensive and has problems with mass productivity.
特開２０１７－００８１４８号公報JP 2017-008148 A 特開２０１６－２２２７９７号公報JP, 2016-222797, A
　本発明は上記のような透明フィルムの課題を解決しようとするものであって、ハードコート層を積層した場合に高い鉛筆硬度となるポリエステルフィルムを安価に提供しようとするものである。 The present invention is intended to solve the problem of the transparent film as described above, and is to provide a polyester film having a high pencil hardness when the hard coat layer is laminated at low cost.
　即ち、本発明は以下の構成よりなる。
１．　極限粘度が０．６０～１．０ｄＬ／ｇのポリエステルフィルムであって、密度法による結晶化度が４８％以上、かつＡＴＲ法によるポリエステルフィルム表面の結晶化度が１．２０以上であるフレキシブルディスプレイの表面保護フィルム用ポリエステルフィルム。
２．　厚みが２５～１８８μｍである上記第１に記載のフレキシブルディスプレイの表面保護フィルム用ポリエステルフィルム。
３．　ポリエステルフィルムが２軸延伸ポリエステルフィルムであり、前記２軸延伸ポリエステルフィルムの少なくとも一方の面に易接着層を有する上記第１または第２に記載のフレキシブルディスプレイの表面保護フィルム用ポリエステルフィルム。
４．　上記第１～第３のいずれかに記載のポリエステルフィルムの少なくとも一方の面にハードコート層を有するフレキシブルディスプレイの表面保護フィルム用ハードコートフィルム。
５．　上記第４に記載のハードコートフィルムを、表面保護フィルムとして用いている表示体。 That is, the present invention has the following constitution.
1. A flexible display having a limiting viscosity of 0.60 to 1.0 dL / g and having a crystallinity of 48% or more by density method and a crystallinity of 1.20 or more of the polyester film surface by ATR method Polyester film for surface protection film.
2. The polyester film for a surface protection film of a flexible display as described in the first above, having a thickness of 25 to 188 μm.
3. The polyester film for surface protection films of the said flexible display as described in said 1st or 2nd which is a biaxially stretched polyester film and which has an easily bonding layer in at least one surface of the said biaxially stretched polyester film.
4. A hard coat film for a surface protection film of a flexible display having a hard coat layer on at least one surface of the polyester film according to any one of the first to third aspects.
5. The display body which uses the hard coat film as described in said 4th as a surface protection film.
　本発明のポリエステルフィルムは、ハードコート層などを積層した場合に表面硬度が一般的なポリエステルフィルムよりも高くなり、ハードコートフィルムが表示体の表面保護フィルムとして用いられることにより、表示体表面の傷、衝撃、変形などに強く、デザイン性にも優れた表示体の提供を可能とした。前記表示体は美しい画像を提供できるものである。 In the polyester film of the present invention, when a hard coat layer or the like is laminated, the surface hardness becomes higher than that of a general polyester film, and the hard coat film is used as a surface protective film of a display body to scratch the display surface. It is possible to provide a display body that is resistant to impact, deformation, etc. and is excellent in design. The display can provide a beautiful image.
（表示体）
　本発明で言う表示体とは、表示装置を全般に指すものであり、ディスプレイの種類としては、ＬＣＤ、有機ＥＬディスプレイ、無機ＥＬディスプレイ、ＬＥＤ、ＦＥＤなどがあるが、折曲げ可能な構造であるＬＣＤや、有機ＥＬ、無機ＥＬが好ましい。特に層構成を少なくし、色域の広い有機ＥＬがさらに好ましい。 (Display body)
The display referred to in the present invention generally refers to a display device, and the types of display include LCD, organic EL display, inorganic EL display, LED, FED, etc., but it has a foldable structure. LCD, organic EL and inorganic EL are preferable. In particular, the layer structure is reduced, and a wide color gamut organic EL is more preferable.
　表示体の形態としては、大型スクリーン、ディスプレイ、デジタルサイネージ、屈曲型携帯端末、パーソナルコンピュータなどあり、限定なく使用できる。特に、直接触れて操作するタッチパネル機能があるタッチパネル付きディスプレイ、デジタルサイネージ、屈曲型携帯端末、パーソナルコンピュータなどに用いることが好ましい。そして、表示体は以下のようなフレキシブルディスプレイであることが特に好ましい。 The form of the display includes a large screen, a display, digital signage, a bendable portable terminal, a personal computer and the like, and can be used without limitation. In particular, it is preferable to use for a display with a touch panel having a touch panel function to be operated by direct touch, digital signage, a bending portable terminal, a personal computer, and the like. And as for a display body, it is especially preferable that it is the following flexible displays.
（フレキシブルディスプレイ）
　フレキシブルディスプレイは、連続した１枚のディスプレイが、用途に従って屈曲できる構造となっているものであり、同時に薄型、軽量化されているものが望ましい。特に折り曲げ型ディスプレイであるフォルダブルディスプレイや、巻取り型ディスプレイであるローラブルディスプレイなどの他、ペーパーライクに使用できるものなどが挙げられる。 (Flexible display)
The flexible display is a structure in which one continuous display can be bent according to the application, and at the same time, it is desirable that the display be thin and lightweight. In particular, in addition to a foldable type display such as a foldable type display and a rollable type display such as a rollable type display, those usable for paper-like may be mentioned.
（ポリエステルフィルム）
　透明フィルムは、ポリイミドフィルム、ポリエステルフィルム、ポリカーボネートフィルム、アクリルフィルム、トリアセチルセルロースフィルム、シクロオレフィンポリマーフィルムなど光透過性が高く、ヘイズが低いフィルムがあるが、その中でも耐衝撃性が高く、適度な鉛筆硬度を有するポリエステルフィルムが好ましく、安価で製造できるポリエチレンテレフタレートフィルムが特に好ましい。 (Polyester film)
Transparent films include films with high light transmittance such as polyimide film, polyester film, polycarbonate film, acrylic film, triacetyl cellulose film, cycloolefin polymer film and low haze, among which high impact resistance and appropriate Polyester films having pencil hardness are preferred, and polyethylene terephthalate films which can be produced inexpensively are particularly preferred.
　本発明において、ポリエステルフィルムは、１以上のポリエステル樹脂からなる単層構成のフィルムでもよいし、２種類以上のポリエステルを使用する場合、多層構造フィルムでも良いし、繰り返し構造の超多層積層フィルムでもよい。 In the present invention, the polyester film may be a film having a single layer structure consisting of one or more polyester resins, or when two or more polyesters are used, a multilayer structure film may be used, or a super multilayer laminated film having a repeated structure may be used. .
　ポリエステル樹脂としては、例えば、ポリエチレンテレフタレート、ポリブチレンテレフタレート、ポリエチレン－２，６－ナフタレート、またはこれらの樹脂の構成成分を主成分とする共重合体からなるポリエステルフィルムが挙げられる。なかでも、力学的性質、耐熱性、透明性、価格などの点から、２軸延伸されたポリエステルフィルムが好ましく、２軸延伸されたポリエチレンテレフタレートフィルムが特に好ましい。 Examples of the polyester resin include polyester films made of polyethylene terephthalate, polybutylene terephthalate, polyethylene-2,6-naphthalate, or a copolymer containing a constituent component of these resins as a main component. Among them, in view of mechanical properties, heat resistance, transparency, cost and the like, a biaxially stretched polyester film is preferable, and a biaxially stretched polyethylene terephthalate film is particularly preferable.
　基材フィルムにポリエステルの共重合体を用いる場合、ポリエステルのジカルボン酸成分としては、例えば、アジピン酸、セバシン酸などの脂肪族ジカルボン酸；テレフタル酸、イソフタル酸、フタル酸、２，６－ナフタレンジカルボン酸などの芳香族ジカルボン酸；トリメリット酸、ピロメリット酸などの多官能カルボン酸が挙げられる。また、グリコール成分としては、例えば、エチレングリコール、ジエチレングリコール、１，４－ブタンジオール、プロピレングリコール、ネオペンチルグリコールなどの脂肪酸グリコール；ｐ－キシレングリコールなどの芳香族グリコール；１，４－シクロヘキサンジメタノールなどの脂環族グリコール；平均分子量が１５０～２０，０００のポリエチレングリコールが挙げられる。好ましい共重合体の共重合成分の質量比率は２０質量％未満である。２０質量％未満の場合には、フィルム強度、透明性、耐熱性が保持されて好ましい。 When a polyester copolymer is used for the base film, examples of the dicarboxylic acid component of the polyester include aliphatic dicarboxylic acids such as adipic acid and sebacic acid; terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid Aromatic dicarboxylic acids such as acids; and polyfunctional carboxylic acids such as trimellitic acid and pyromellitic acid. Also, as the glycol component, for example, fatty acid glycols such as ethylene glycol, diethylene glycol, 1,4-butanediol, propylene glycol, neopentyl glycol and the like; aromatic glycols such as p-xylene glycol; 1,4-cyclohexanedimethanol and the like Alicyclic glycols; polyethylene glycol having an average molecular weight of 150 to 20,000. The mass ratio of the copolymer component of the preferable copolymer is less than 20% by mass. In the case of less than 20% by mass, film strength, transparency and heat resistance are preferably maintained.
　また、ポリエステルフィルムの製造において、少なくとも１種類以上の樹脂ペレットの極限粘度は、０．６０～１．０ｄｌ／ｇの範囲が好ましい。極限粘度が０．６０ｄｌ／ｇ以上であると、ハードコート加工後の鉛筆硬度が向上するため好ましい。更に好ましくは０．６５ｄｌ／ｇ以上、特に好ましくは０．７０ｄｌ／ｇ以上である。一方、極限粘度が１．００ｄｌ／ｇ以下であると、溶融流体の濾圧上昇が大きくなり過ぎることなく、フィルム製造を安定的に操業し易く好ましい。 Further, in the production of a polyester film, the intrinsic viscosity of at least one resin pellet is preferably in the range of 0.60 to 1.0 dl / g. When the intrinsic viscosity is 0.60 dl / g or more, the pencil hardness after hard coating is preferably improved. More preferably, it is 0.65 dl / g or more, particularly preferably 0.70 dl / g or more. On the other hand, when the intrinsic viscosity is 1.00 dl / g or less, it is preferable that the film production can be stably operated stably without the increase in filtration pressure of the molten fluid becoming too large.
　フィルムが単層構成、積層構成であることに関わらず、フィルムの極限粘度は、０．６０ｄｌ／ｇ以上であることが好ましい。ポリエステル樹脂の分子量が上がることでフィルムの弾性挙動が向上し、鉛筆硬度測定時の鉛筆の荷重に対して、変形を効果的に抑制することができるため好ましい。更に好ましくは０．６５ｄｌ／ｇ以上、特に好ましくは０．７０ｄｌ／ｇ以上である。一方、極限粘度が高くなることで鉛筆硬度も向上するが、生産性が低下する懸念があるため、極限粘度が１．００ｄｌ／ｇ以下では、操業性よく製造できるため好ましい。 It is preferable that the intrinsic viscosity of the film is 0.60 dl / g or more regardless of whether the film has a single-layer structure or a laminated structure. The increase in molecular weight of the polyester resin is preferable because the elastic behavior of the film is improved, and deformation can be effectively suppressed with respect to the load of the pencil at the time of pencil hardness measurement. More preferably, it is 0.65 dl / g or more, particularly preferably 0.70 dl / g or more. On the other hand, although the pencil hardness is also improved by the increase in the intrinsic viscosity, there is a concern that the productivity may be lowered. Therefore, the intrinsic viscosity of 1.00 dl / g or less is preferable because it can be produced with good operability.
　ポリエステルフィルムの厚みは、２５～１８８μｍであることが好ましく、２５～１２５μｍであることがさらに好ましい。厚みが２５μｍ以上であるとハンドリング性、耐衝撃性が向上し好ましく、厚みが１８８μｍ以下であると軽量化に有利である他、可撓性、加工性に優れ好ましい。 The thickness of the polyester film is preferably 25 to 188 μm, and more preferably 25 to 125 μm. When the thickness is 25 μm or more, the handling property and the impact resistance are preferably improved, and when the thickness is 188 μm or less, it is advantageous for reducing the weight, and it is preferably excellent in flexibility and processability.
　本発明のポリエステルフィルムの表面は、平滑であっても凹凸を有していても良いが、表示体表面の保護フィルム用途に用いられることから、凹凸由来の光学特性低下は好ましくない。ヘイズとしては、３％以下が好ましく、２％以下がさらに好ましく、１％以下が最も好ましい。ヘイズが３％以下であれば、画像の視認性を向上させることができる。ヘイズの下限は小さいほどよいが、０．１％以上でも構わず、０．３％以上でも構わない。 The surface of the polyester film of the present invention may be smooth or have asperities, but since it is used for a protective film application on the surface of a display, it is not preferable to reduce the optical characteristics derived from asperities. The haze is preferably 3% or less, more preferably 2% or less, and most preferably 1% or less. If the haze is 3% or less, the visibility of the image can be improved. The lower limit of the haze is preferably as small as possible, but may be 0.1% or more, and may be 0.3% or more.
　前記のようにヘイズを低下させる目的からはあまりフィルム表面の凹凸は大きくない方がよいが、ハンドリング製の観点から程度な滑り性を与えるために、凹凸を形成する方法としては、表層のポリエステル樹脂層にフィラーを配合したり、フィラー入りのコート層を製膜途中でコーティングすることで形成することができる。 As described above, the unevenness on the film surface should not be too large for the purpose of reducing the haze, but the polyester resin of the surface layer is a method for forming the unevenness to give a moderate slipperiness from the viewpoint of handling. The layer can be formed by blending a filler or coating a filler-containing coat layer during film formation.
　基材フィルムに粒子を配合する方法としては、公知の方法を採用できる。例えば、ポリエステルを製造する任意の段階において添加することができるが、好ましくはエステル化の段階、またはエステル交換反応終了後、重縮合反応開始前の段階で、エチレングリコールなどに分散させたスラリーとして添加し、重縮合反応を進めてもよい。また、ベント付き混練押出機を用い、エチレングリコールまたは水などに分散させた粒子のスラリーとポリエステル原料とをブレンドする方法、または混練押出機を用い、乾燥させた粒子とポリエステル原料とをブレンドする方法などによって行うことができる。 A well-known method is employable as a method of mix | blending particle | grains with a base film. For example, although it can be added at any stage of producing polyester, it is preferably added as a slurry dispersed in ethylene glycol or the like at the stage of esterification or after completion of transesterification and before the start of polycondensation reaction. And the polycondensation reaction may proceed. Also, a method of blending a slurry of particles dispersed in ethylene glycol or water with a polyester raw material using a vented kneading extruder, or a method of blending dried particles and a polyester raw material using a kneading extruder And so on.
　なかでも、ポリエステル原料の一部となるモノマー液中に凝集体無機粒子を均質分散させた後、濾過したものを、エステル化反応前、エステル化反応中またはエステル化反応後のポリエステル原料の残部に添加する方法が好ましい。この方法によると、モノマー液が低粘度であるので、粒子の均質分散やスラリーの高精度な濾過が容易に行えると共に、原料の残部に添加する際に、粒子の分散性が良好で、新たな凝集体も発生しにくい。かかる観点より、特に、エステル化反応前の低温状態の原料の残部に添加することが好ましい。 Among them, after the aggregate inorganic particles are homogeneously dispersed in the monomer liquid to be a part of the polyester raw material, the filtered product is used as the remainder of the polyester raw material before the esterification reaction, during the esterification reaction or after the esterification reaction. The method of adding is preferable. According to this method, since the monomer liquid has a low viscosity, uniform dispersion of particles and high-precision filtration of the slurry can be easily performed, and the dispersibility of the particles is good when added to the remaining portion of the raw material. Aggregates are also less likely to occur. From such a point of view, it is particularly preferable to add to the balance of the raw material in the low temperature state before the esterification reaction.
　また、予め粒子を含有するポリエステルを得た後、そのペレットと粒子を含有しないペレットとを混練押出しなどする方法（マスターバッチ法）により、さらにフィルム表面の突起数を少なくすることができる。 Further, after the polyester containing particles is obtained in advance, the number of projections on the film surface can be further reduced by a method (master batch method) in which the pellets and the pellets containing no particles are kneaded and extruded.
　また、ポリエステルフィルムは、全光線透過率の好ましい範囲を維持する範囲内で、各種の添加剤を含有していてもよい。添加剤としては、例えば、帯電防止剤、ＵＶ吸収剤、安定剤が挙げられる。 Moreover, the polyester film may contain various additives within the range which maintains the preferable range of the total light transmittance. As an additive, an antistatic agent, a UV absorber, and a stabilizer are mentioned, for example.
　ポリエステルフィルムの全光線透過率は、８５％以上が好ましく、８７％以上がさらに好ましい。８５％以上の透過率があれば、視認性を十分に確保することができる。ポリエステルフィルムの全光線透過率は高いほどよいと言えるが、９９％以下でも構わず、９７％以下でも構わない。 The total light transmittance of the polyester film is preferably 85% or more, and more preferably 87% or more. If the transmittance is 85% or more, sufficient visibility can be ensured. The higher the total light transmittance of the polyester film, the better, but it may be 99% or less, or 97% or less.
　本発明のポリエステルフィルムの表面に、ハードコート層などを形成する樹脂との密着性を向上させるための処理を行うことができる。 The surface of the polyester film of the present invention can be treated to improve the adhesion to the resin forming the hard coat layer and the like.
　表面処理による方法としては、例えば、サンドブラスト処理、溶剤処理等による凹凸化処理や、コロナ放電処理、電子線照射処理、プラズマ処理、オゾン・紫外線照射処理、火炎処理、クロム酸処理、熱風処理等の酸化処理等が挙げられ、特に限定なく使用できる。 As a method by surface treatment, for example, unevenness treatment such as sand blasting treatment, solvent treatment, corona discharge treatment, electron beam irradiation treatment, plasma treatment, ozone / ultraviolet radiation treatment, flame treatment, chromic acid treatment, hot air treatment etc. An oxidation treatment etc. are mentioned and it can use without limitation in particular.
　また、易接着層などの接着向上層により、密着性を向上させることもできる。易接着層としては、アクリル樹脂、ポリエステル樹脂、ポリウレタン樹脂、ポリエーテル樹脂など特に限定なく使用でき、一般的なコーティング手法、好ましくはいわゆるインラインコート処方により形成できる。 The adhesion can also be improved by an adhesion improving layer such as an easy adhesion layer. The easily adhesive layer can be used without particular limitation, such as acrylic resin, polyester resin, polyurethane resin, polyether resin, etc., and can be formed by a general coating method, preferably a so-called in-line coating formulation.
　上述のポリエステルフィルムは、例えば、ポリエステル原料の一部となるモノマー液中に無機粒子を均質分散させて濾過した後、ポリエステル原料の残部に添加してポリエステルの重合を行う重合工程と、そのポリエステルをフィルターを介してシート状に溶融押し出し、これを冷却後、延伸して、基材フィルムを形成するフィルム形成工程を経て、製造することができる。 The above-mentioned polyester film is obtained, for example, by uniformly dispersing inorganic particles in a monomer liquid which is a part of the polyester raw material and filtering it, and then adding it to the remainder of the polyester raw material to carry out polymerization of the polyester. It can melt-extrude to a sheet form through a filter, and after cooling, it extends | stretches and can be manufactured through the film formation process of forming a base film.
　次に、２軸延伸ポリエステルフィルムの製造方法について、ポリエチレンテレフタレート（以下、ＰＥＴと記す場合がある）のペレットを基材フィルムの原料とした例について詳しく説明するが、これらに限定されるものではない。また、単層構成、多層構成など層数を限定するものではない。 Next, an example of using a pellet of polyethylene terephthalate (hereinafter sometimes referred to as PET) as a raw material of a substrate film will be described in detail for a method of producing a biaxially stretched polyester film, but is not limited thereto. . Further, the number of layers is not limited, such as a single layer structure or a multilayer structure.
　ＰＥＴのペレットを所定の割合で混合、乾燥した後、公知の溶融積層用押出機に供給し、スリット状のダイからシート状に押し出し、キャスティングロール上で冷却固化させて、未延伸フィルムを形成する。単層の場合は１台の押し出し機でよいが、多層構成のフィルムを製造する場合には、２台以上の押出機、２層以上のマニホールドまたは合流ブロック（例えば、角型合流部を有する合流ブロック）を用いて、各最外層を構成する複数のフィルム層を積層し、口金から２層以上のシートを押し出し、キャスティングロールで冷却して未延伸フィルムを形成することができる。 Pellets of PET are mixed and dried at a predetermined ratio, and then fed to a known melt-layering extruder, extruded from a slit die into a sheet, cooled and solidified on a casting roll to form an unstretched film . In the case of a single layer, it may be a single extruder, but in the case of producing a film having a multilayer structure, two or more extruders, two or more manifolds or merging blocks (for example, merging with square junctions) A plurality of film layers constituting each outermost layer can be laminated using a block), and a sheet of two or more layers can be extruded from a die and cooled with a casting roll to form an unstretched film.
　この場合、溶融押出しの際、溶融樹脂が約２８０℃程度に保たれた任意の場所で、樹脂中に含まれる異物を除去するために高精度濾過を行うことが好ましい。溶融樹脂の高精度濾過に用いられる濾材は、特に限定されないが、ステンレス焼結体の濾材は、Ｓｉ、Ｔｉ、Ｓｂ、Ｇｅ、Ｃｕを主成分とする凝集物および高融点有機物の除去性能に優れるため好ましい。 In this case, in melt extrusion, high precision filtration is preferably performed at any place where the molten resin is maintained at about 280 ° C., in order to remove foreign matter contained in the resin. The filter medium used for high-precision filtration of the molten resin is not particularly limited, but the filter medium of the stainless sintered body is excellent in the removal performance of aggregates mainly composed of Si, Ti, Sb, Ge, and Cu and high melting point organic substances Because it is preferable.
　さらに、濾材の濾過粒子サイズ（初期濾過効率９５％）は、２０μｍ以下が好ましく、特に１５μｍ以下が好ましい。濾材の濾過粒子サイズ（初期濾過効率９５％）が２０μｍを超えると、２０μｍ以上の大きさの異物が十分除去できない。濾材の濾過粒子サイズ（初期濾過効率９５％）が２０μｍ以下の濾材を用いて溶融樹脂の高精度濾過を行うことにより、生産性が低下する場合があるが、粗大粒子による突起の少ないフィルムを得る上で好ましい。 Furthermore, the filter particle size (initial filtration efficiency 95%) of the filter medium is preferably 20 μm or less, and particularly preferably 15 μm or less. When the filtration particle size (initial filtration efficiency 95%) of the filter medium exceeds 20 μm, foreign matter having a size of 20 μm or more can not be sufficiently removed. High-precision filtration of a molten resin using a filter medium with a filter particle size (initial filtration efficiency 95%) of 20 μm or less may reduce the productivity, but a film with few protrusions due to coarse particles is obtained. Preferred above.
　具体的には、例えば、ＰＥＴのペレットを十分に真空乾燥した後、押出し機に供給し、約２８０℃でシート状に溶融押し出し、冷却固化させて、未延伸ＰＥＴシートを形成する。得られた未延伸シートを８０～１２０℃に加熱したロールで長手方向に２．５～５．０倍延伸して、一軸配向ＰＥＴフィルムを得る。さらに、フィルムの端部をクリップで把持して、８０～１８０℃に加熱された熱風ゾーンに導き、乾燥後、幅方向に２．５～５．０倍に延伸する。引き続き、１６０～２５０℃の熱処理ゾーンに導き、１～６０秒間の熱処理を行い、結晶配向を完了させる。この熱処理工程中で、必要に応じて、幅方向または長手方向に１～１２％の弛緩処理を施してもよい。 Specifically, for example, pellets of PET are sufficiently vacuum dried and then supplied to an extruder, melt extruded into a sheet at about 280 ° C., and solidified by cooling to form an unstretched PET sheet. The obtained unstretched sheet is stretched 2.5 to 5.0 times in the longitudinal direction with a roll heated to 80 to 120 ° C. to obtain a uniaxially oriented PET film. Furthermore, the end of the film is gripped by a clip, led to a hot air zone heated to 80 to 180 ° C., and after drying, it is stretched by 2.5 to 5.0 times in the width direction. Subsequently, it is led to a heat treatment zone at 160 to 250 ° C., and heat treatment is performed for 1 to 60 seconds to complete crystal orientation. During the heat treatment step, 1 to 12% relaxation treatment may be performed in the width direction or the longitudinal direction, as needed.
（結晶化度）
　結晶化度は主に熱処理ゾーンでのフィルムにかかる熱量によって決まる。熱量は、製膜設備条件、製膜速度、フィルム厚さなど種々条件によって決まるため、熱処理温度だけで結晶化度が決まるものでもないが、熱処理温度としては、１６０～２５０℃が好ましく、２００～２４０℃がさらに好ましいと言える。１６０℃以上とすることで結晶化を促進させることができて好ましい。２５０℃以下で熱処理することで、ポリエステルの再溶融による結晶化低下を抑制することができて好ましい。 (Degree of crystallinity)
The degree of crystallinity is mainly determined by the amount of heat applied to the film in the heat treatment zone. The amount of heat is determined by various conditions such as film forming equipment conditions, film forming speed, film thickness, etc., so the degree of crystallization is not determined only by the heat treatment temperature, but the heat treatment temperature is preferably 160 to 250 ° C. It may be said that 240 ° C. is more preferable. By setting the temperature to 160 ° C. or higher, crystallization can be promoted, which is preferable. Heat treatment at 250 ° C. or less is preferable because it can suppress a decrease in crystallization due to remelting of the polyester.
　ハードコート加工後の十分な鉛筆硬度を確保するためには、密度法によるフィルムの結晶化度が４８％以上であり、ＡＴＲ法によるフィルム表面の結晶化度が１．２０以上であることが好ましい。 In order to ensure sufficient pencil hardness after hard coating, it is preferable that the crystallinity of the film by the density method is 48% or more, and the crystallinity of the film surface by the ATR method is 1.20 or more .
　密度法によるポリエステルフィルムの結晶化度は、４８％以上であることが好ましく、５０％以上であることがより好ましく、５２％以上であることが更に好ましい。結晶化度は高いことが好ましいが、製造できるフィルムの上限は６５％程度である。 The crystallinity of the polyester film by the density method is preferably 48% or more, more preferably 50% or more, and still more preferably 52% or more. The degree of crystallinity is preferably high, but the upper limit of the film that can be produced is about 65%.
　ＡＴＲ法によるフィルム表面の結晶化度は１．２０以上であることが好ましく、１．２５以上であることがより好ましく、１．２７以上であることが更に好ましい。ＡＴＲ法によるフィルム表面の結晶化度についても高いことが好ましいが、製造できるフィルムの上限は３．０程度である。 The crystallinity of the film surface according to the ATR method is preferably 1.20 or more, more preferably 1.25 or more, and still more preferably 1.27 or more. The crystallinity of the film surface by the ATR method is also preferably high, but the upper limit of the film that can be produced is about 3.0.
（易接着層）
　易接着層は、前記塗布液を未延伸又は縦方向の１軸延伸フィルムの片面または両面に塗布した後、１００～１５０℃で乾燥し、さらに１方向または２方向に延伸して得ることができる。最終的な易接着層の塗布量は、０．０５～０．２０ｇ／ｍ２に管理することが好ましい。塗布量が０．０５ｇ／ｍ２以上であると、接着性が満たされて好ましい。一方、塗布量が０．２０ｇ／ｍ２以下であると、耐ブロッキング性が得られて好ましい。 (Easy adhesion layer)
The easy-adhesion layer can be obtained by applying the coating solution on one side or both sides of a uniaxially stretched film not stretched or in the longitudinal direction, then drying at 100 to 150 ° C., and stretching it in one direction or two directions. . The final coating amount of the easy adhesion layer is preferably controlled to 0.05 to 0.20 g / m 2 . Adhesiveness is satisfy | filled as a coating amount is 0.05 g / m < 2 > or more, and it is preferable. On the other hand, when the coating amount is 0.20 g / m 2 or less, blocking resistance is preferably obtained.
　易接着層に用いられる樹脂としては、例えばポリエステル系樹脂、ポリウレタン系樹脂、ポリエステルポリウレタン樹脂、ポリカーボネートポリウレタン樹脂、アクリル樹脂等、特に限定なく使用できる。易接着層の架橋剤としては、メラミン系、イソシアネート系、オキサゾリン系、エポキシ系などの架橋剤が挙げられる。２種以上を混合して使用することもできる。これらはインラインコートの性質上、水系塗布液によって塗工されることが好ましく、前記の樹脂や架橋剤は水溶性又は水分散性の樹脂や化合物であることが好ましい。 As resin used for an easily bonding layer, it is possible to use without particular limitation, for example, polyester resin, polyurethane resin, polyester polyurethane resin, polycarbonate polyurethane resin, acrylic resin and the like. As a crosslinking agent of an easily bonding layer, crosslinking agents, such as melamine type, an isocyanate type, an oxazoline type, an epoxy type, are mentioned. Two or more kinds can be mixed and used. These are preferably coated with a water-based coating solution in view of the properties of the in-line coating, and the above-mentioned resin and crosslinking agent are preferably water-soluble or water-dispersible resins and compounds.
　易接着層には易滑性を付与するために粒子を添加することが好ましい。微粒子の平均粒径は２μｍ以下であることが好ましい。粒子の平均粒径が２μｍを超えると、粒子が易接着層から脱落しやすくなる。易接着層に含有させる粒子としては、例えば、酸化チタン、硫酸バリウム、炭酸カルシウム、硫酸カルシウム、シリカ、アルミナ、タルク、カオリン、クレー、リン酸カルシウム、雲母、ヘクトライト、ジルコニア、酸化タングステン、フッ化リチウム、フッ化カルシウム等の無機粒子や、スチレン系、アクリル系、メラミン系、ベンゾグアナミン系、シリコーン系等の有機ポリマー系粒子等が挙げられる。これらは、単独で易接着層に添加されてもよく、２種以上を組合せて添加することもできる。 It is preferable to add particles to the easily adhesive layer in order to impart slipperiness. The average particle diameter of the fine particles is preferably 2 μm or less. When the average particle diameter of the particles exceeds 2 μm, the particles are easily detached from the easily adhesive layer. The particles to be contained in the easy adhesion layer include, for example, titanium oxide, barium sulfate, calcium carbonate, calcium sulfate, silica, alumina, talc, kaolin, clay, calcium phosphate, mica, hectorite, zirconia, tungsten oxide, lithium fluoride, Examples thereof include inorganic particles such as calcium fluoride, and organic polymer particles such as styrene type, acrylic type, melamine type, benzoguanamine type and silicone type particles. These may be added alone to the easily bonding layer, or two or more may be added in combination.
　また、塗布液を塗布する方法としては、上記の塗布層と同様に公知の方法を用いることができる。例えば、リバースロール・コート法、グラビア・コート法、キス・コート法、ロールブラッシュ法、スプレーコート法、エアナイフコート法、ワイヤーバーコート法、パイプドクター法、などが挙げられ、これらの方法を単独であるいは組み合わせて行うことができる。 Moreover, as a method of apply | coating a coating liquid, the well-known method can be used similarly to said application layer. For example, reverse roll coating method, gravure coating method, kiss coating method, roll brush method, spray coating method, air knife coating method, wire bar coating method, pipe doctor method, etc. may be mentioned, and these methods may be used alone. Or it can carry out in combination.
（ハードコート層）
　ハードコート層を形成する樹脂としては、（メタ）アクリル酸エステル、シロキサン系、無機ハイブリッド系、ウレタンアクリレート系、ポリエステルアクリレート系、エポキシ系など特に限定なく使用できる。また、２種類以上の材料を混合して用いることもできるし、無機フィラーや有機フィラーなどの粒子を添加することもできる。その中でも、（メタ）アクリル酸エステルや、アクリレート系樹脂が好ましく、必須成分として分子内に３以上の反応性基を有する樹脂が好ましい。 (Hard coat layer)
As the resin for forming the hard coat layer, (meth) acrylic acid ester, siloxane type, inorganic hybrid type, urethane acrylate type, polyester acrylate type, epoxy type and the like can be used without particular limitation. Moreover, two or more types of materials can be mixed and used, and particles, such as an inorganic filler and an organic filler, can also be added. Among them, (meth) acrylic acid esters and acrylate resins are preferable, and resins having three or more reactive groups in the molecule as an essential component are preferable.
（３以上の反応性基を有する樹脂）
３以上の反応性基を有する樹脂としては、例えばトリス(２－アクリロイルオキシエチル)イソシアヌレート、トリス(３－アクリロイルオキシプロピル)イソシアヌレート、トリス(２－メタクリロイルオキシエチル)イソシアヌレート、トリス(３－メタクリロイルオキシプロピル)イソシアヌレートなどのトリス[(メタ)アクリロイルオキシアルキル]イソシアヌレート、さらにはトリメチロールプロパントリ(メタ)アクリレート、ジペンタエリスリトールトリ(メタ)アクリレート、プロピオン酸変性ジペンタエリスリトールトリ(メタ)アクリレート、ペンタエリスリトールトリ(メタ)アクリレート、プロピレンオキシド変性トリメチロールプロパントリ(メタ)アクリレート、ジペンタエリスリトールテトラ(メタ)アクリレート、プロピオン酸変性ジペンタエリスリトールペンタ(メタ)アクリレート、ジペンタエリスリトールヘキサ(メタ)アクリレート、カプロラクトン変性ジペンタエリスリトールヘキサ(メタ)アクリレートなどの(メタ)アクリレートが挙げられる。これらは１種を単独で用いてもよく、２種以上を組み合わせて用いてもよい。 (Resin having 3 or more reactive groups)
Examples of resins having three or more reactive groups include tris (2-acryloyloxyethyl) isocyanurate, tris (3-acryloyloxypropyl) isocyanurate, tris (2-methacryloyloxyethyl) isocyanurate, and tris (3- (3-acryloyloxyethyl) isocyanurate. Tris [(meth) acryloyloxyalkyl] isocyanurate such as methacryloyloxypropyl) isocyanurate, and further trimethylolpropane tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, propionic acid modified dipentaerythritol tri (meth) Acrylate, pentaerythritol tri (meth) acrylate, propylene oxide modified trimethylolpropane tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, propionic acid modified dipen Erythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, (meth) acrylates such as caprolactone-modified dipentaerythritol hexa (meth) acrylate. One of these may be used alone, or two or more of these may be used in combination.
　そのほか、市販品のハードコート剤なども使用できる。例えば、荒川化学工業社製ビームセット（登録商標）シリーズ、アイカ工業社製アイカアイトロン（登録商標）シリーズ、東洋インキ社製Lioduras（登録商標）シリーズなど、特に限定なく使用でき、他の（メタ）アクリル酸エステル化合物類と混合して使用することもできる。 Other than these, commercially available hard coating agents can also be used. For example, beam set (registered trademark) series manufactured by Arakawa Chemical Industries, Aika Intron (registered trademark) series manufactured by Aika Industries, Lioduras (registered trademark) series manufactured by Toyo Ink Co., Ltd., etc. can be used without particular limitation. ) It can also be used by mixing it with acrylic acid ester compounds.
（光重合開始剤）
　本発明のハードコート層を、紫外線を用いて硬化する場合には、光重合開始剤を添加することが必要となる。光重合開始剤としては、具体的には、ベンゾフェノン、アセトフェノン、ベンゾイン、ベンゾインメチルエーテル、ベンゾインエチルエーテル、ベンゾインイソプロピルエーテル、ベンゾインイソブチルエーテル、ベンゾイン安息香酸、ベンゾイン安息香酸メチル、ベンゾインジメチルケタール、２，４－ジエチルチオキサンソン、１－ヒドロキシシクロヘキシルフェニルケトン、ベンジルジフェニルサルファイド、テトラメチルチウラムモノサルファイド、アゾビスイソブチロニトリル、ベンジル、ジベンジル、ジアセチル、β－クロールアンスラキノン、（２，４，６－トリメチルベンジルジフェニル）フォスフィンオキサイド、２－ベンゾチアゾール－Ｎ，Ｎ－ジエチルジチオカルバメート等が挙げられる。特に、表面硬化性に優れるとされる、２－ヒドロキシ－１－{４－[４－（２－ヒドロキシ－２－メチル－プロピオニル）－ベンジル]－フェニル}－２－メチルプロパン－１－オン、１－ヒドロキシ－シクロヘキシル－フェニル－ケトン、２－ヒドロキシ－２－メチル－１－フェニル－プロパン－１－オン、２－メチル－１－[４－（メチルチオ）フェニル]－２－モルフォリノプロパン－１－オンが好ましく、中でも２－ヒドロキシ－２－メチル－１－フェニル－プロパン－１－オン、２－メチル－１－[４
－（メチルチオ）フェニル]－２－モルフォリノプロパン－１－オンが特に好ましい。こ
れらは単独で用いてもよいし、２種以上を組み合わせて用いてもよい。 (Photopolymerization initiator)
When the hard coat layer of the present invention is cured using ultraviolet light, it is necessary to add a photopolymerization initiator. Specific examples of the photopolymerization initiator include benzophenone, acetophenone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, methyl benzoin benzoate, benzoin dimethyl ketal, 2,4 -Diethylthioxanthone, 1-hydroxycyclohexyl phenyl ketone, benzyl diphenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, benzyl, dibenzyl, diacetyl, β-chloro anthraquinone, (2,4,6-trimethyl And benzyl diphenyl) phosphine oxide, 2-benzothiazole-N, N-diethyldithiocarbamate and the like. In particular, 2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] -phenyl} -2-methylpropan-1-one, which is considered to be excellent in surface curability. 1-hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1 -One is preferred, among which 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 2-methyl-1- [4
Particular preference is given to-(methylthio) phenyl] -2-morpholinopropan-1-one. These may be used alone or in combination of two or more.
　光重合開始剤の添加量は、特に限定されない。例えば、用いられる樹脂に対して１～１０質量％程度を用いることが好ましい。１質量％以上添加することで十分な硬化性を得ることができ、１０質量％以下とすることで３以上の反応性基を有する樹脂の含有比率が高く、高架橋密度で高硬度なハードコート膜にすることができる。 The addition amount of the photopolymerization initiator is not particularly limited. For example, it is preferable to use about 1 to 10% by mass with respect to the resin to be used. Sufficient curability can be obtained by adding 1% by mass or more, and by setting the content to 10% by mass or less, the content ratio of the resin having three or more reactive groups is high, and a hard coat film having high crosslinking density and high hardness Can be
（膜厚）
　ハードコート層の膜厚としては、１～４０μｍが好ましい。１μｍより厚ければ十分に硬化し、良好な鉛筆硬度が得られる。また厚みを４０μｍ以下にすることで、ハードコートの硬化収縮によるカールを抑制し、フィルムのハンドリング性を向上させることができる。 (Film thickness)
The thickness of the hard coat layer is preferably 1 to 40 μm. If it is thicker than 1 μm, it is sufficiently cured to obtain good pencil hardness. In addition, by setting the thickness to 40 μm or less, curling due to curing shrinkage of the hard coat can be suppressed, and the handling property of the film can be improved.
（塗布方法）
　ハードコート層の塗布方法としては、マイヤーバー、グラビアコート、ダイコーター、ナイフコーターなど特に限定なく使用でき、粘度、膜厚に応じて適宜選択できる。乾燥温度は６０～１００℃が好ましく、６０～９０℃がさらに好ましい。６０℃以上であれば短時間で十分に乾燥でき、１００℃以下であればポリエステルフィルムの変形など発生せず好ましい。 (Coating method)
As a coating method of a hard-coat layer, it can be used without particular limitation, such as a Mayer bar, a gravure coat, a die coater, a knife coater, etc. It can select suitably according to a viscosity and a film thickness. The drying temperature is preferably 60 to 100 ° C., and more preferably 60 to 90 ° C. If it is 60 ° C. or more, it can be sufficiently dried in a short time, and if it is 100 ° C. or less, deformation of the polyester film does not occur, which is preferable.
（硬化条件）
　ハードコート層の硬化方法としては、紫外線、電子線などのエネルギー線や、熱による硬化方法など使用できるが、フィルムへのダメージを軽減させるため、紫外線や電子線などが好ましい。 (Curing conditions)
As a method of curing the hard coat layer, energy rays such as ultraviolet rays and electron beams, and a method of curing by heat can be used, but ultraviolet rays and electron beams are preferable in order to reduce damage to the film.
（紫外線）
　紫外線ランプとして、高圧水銀ランプ、無電極ランプなどあるが適宜選択して使用することができる。紫外線の積算光量としては、５０～５００ｍＪ／ｃｍ２が好ましく、１００～２００ｍＪ／ｃｍ２がさらに好ましい。５０ｍＪ／ｃｍ２以上の積算光量を照射すれば十分な鉛筆硬度が得られ、５００ｍＪ／ｃｍ２以下の積算光量であれば加工速度を上げることができ、経済性が向上し好ましい。窒素、アルゴン、二酸化炭素などの不活性ガス中で紫外線を照射することで硬化性を向上することもでき、適宜選択できる。 (UV)
There are a high pressure mercury lamp, an electrodeless lamp, etc. as an ultraviolet lamp, but it can be used by selecting suitably. The integrated light quantity of ultraviolet light is preferably 50 to 500 mJ / cm 2, and more preferably 100 to 200 mJ / cm 2 . Sufficient pencil hardness can be obtained by irradiating the integrated light amount of 50 mJ / cm 2 or more, and the processing speed can be increased if the integrated light amount is 500 mJ / cm 2 or less, which is preferable because the economic efficiency is improved. The curability can also be improved by irradiation with ultraviolet light in an inert gas such as nitrogen, argon or carbon dioxide, which can be appropriately selected.
（電子線）
　電子線照射装置は、エリア型、走査型などあるが、適宜選択して使用することができる。電子線の積算照射量としては、２５～５００ｋＧｙが好ましく、５０～３００ｋＧｙがさらに好ましい。２５ｋＧｙ以上の積算照射量を照射すれば十分な鉛筆硬度が得られ、５００ｋＧｙ以下であれば加工速度を上げることができ、経済性が向上し好ましい。窒素、アルゴンなどの不活性ガス中で、酸素濃度５００ｐｐｍ以下で照射することが好ましい。酸素濃度を５００ｐｐｍ以下とすることでオゾン発生を抑制し、作業時の安全性を向上することができる。 (Electron beam)
The electron beam irradiation apparatus is an area type, a scanning type, etc., but can be appropriately selected and used. The integrated irradiation dose of the electron beam is preferably 25 to 500 kGy, more preferably 50 to 300 kGy. Sufficient pencil hardness can be obtained by irradiating an accumulated irradiation dose of 25 kGy or more, and if it is 500 kGy or less, the processing speed can be increased, which is preferable because economic efficiency is improved. Irradiation is preferably performed at an oxygen concentration of 500 ppm or less in an inert gas such as nitrogen or argon. By setting the oxygen concentration to 500 ppm or less, the generation of ozone can be suppressed, and the safety during operation can be improved.
（鉛筆硬度）
　ハードコート層の鉛筆硬度としては、２Ｈ以上が好ましく、３Ｈ以上が更に好ましく、４Ｈ以上が特に好ましい。２Ｈ以上の鉛筆硬度があれば、容易に変形することはなく、視認性を低下させない。一般にハードコート層の鉛筆硬度は高い方が好ましいが１０Ｈ以下で構わず、８Ｈ以下でも構わず、６Ｈ以下でも実用上は問題なく使用できる。 (Pencil hardness)
The pencil hardness of the hard coat layer is preferably 2H or more, more preferably 3H or more, and particularly preferably 4H or more. If the pencil hardness is 2H or more, it does not easily deform and does not reduce the visibility. Generally, the pencil hardness of the hard coat layer is preferably high, but it may be 10 H or less, 8 H or less, or 6 H or less, which can be used practically without problems.
（ハードコート層の種類）
　本発明におけるハードコート層は、上述のような表面の鉛筆硬度を高めてディスプレイの保護をする目的に使用できるものであれば、他の機能が付加されたものであってもよい。例えば、上記のような一定の鉛筆硬度を有する防眩層、防眩性反射防止層、反射防止層、低反射層および帯電防止層などの機能性が付加されたハードコート層も本発明おいては好ましく適用される。 (Type of hard coat layer)
The hard coat layer in the present invention may be one to which another function is added as long as it can be used for the purpose of protecting the display by increasing the pencil hardness of the surface as described above. For example, in the present invention, a hard coat layer to which functions such as an antiglare layer having a certain pencil hardness as described above, an antiglare antireflection layer, an antireflection layer, a low reflection layer, and an antistatic layer are added is also included. Is preferably applied.
　次に、本発明の効果を実施例および比較例を用いて説明する。まず、本発明で使用した特性値の評価方法を下記に示す。 Next, the effects of the present invention will be described using examples and comparative examples. First, evaluation methods of characteristic values used in the present invention are shown below.
（１）極限粘度
　フィルムまたはポリエステル樹脂を粉砕して乾燥した後、フェノール／テトラクロロエタン＝６０／４０（質量比）の混合溶媒に溶解した。この溶液に遠心分離処理を施して無機粒子を取り除いた後に、ウベローデ粘度計を用いて、３０℃で０．４（ｇ／ｄｌ）の濃度の溶液の流下時間及び溶媒のみの流下時間を測定し、それらの時間比率から、Ｈｕｇｇｉｎｓの式を用い、Ｈｕｇｇｉｎｓの定数が０．３８であると仮定して極限粘度を算出した。積層フィルムの場合は、積層厚みに応じて、フィルムの該当するポリエステル層を削り取ることで、各層単体の極限粘度を評価した。 (1) Intrinsic Viscosity After the film or polyester resin was pulverized and dried, it was dissolved in a mixed solvent of phenol / tetrachloroethane = 60/40 (mass ratio). After centrifuging this solution to remove inorganic particles, the flow time of the solution with a concentration of 0.4 (g / dl) and the flow time of the solvent alone were measured using a Ubbelode viscometer at 30 ° C. From these time ratios, the limiting viscosity was calculated using the Huggins equation and assuming that the Huggins constant is 0.38. In the case of the laminated film, the limiting viscosity of each layer alone was evaluated by scraping off the corresponding polyester layer of the film according to the laminated thickness.
（２）密度法による結晶化度
　フィルムサンプルの密度を３点測定し、その平均値を結晶化度とした。樹脂成分は完全非晶と完全結晶の混合物であり、その密度が後述の通りであり、サンプルの密度はサンプルを構成する各成分の質量の総和を各成分の体積の総和で除した値となる、との仮定に基づき、各樹脂の結晶化度（重量比）を推算した。なお、サンプルの密度ＪＩＳＫ－７１１２－１９８０準拠の方法（密度勾配管法）に従って行った。結晶化度の計算式は以下のとおりであり、各成分単独の密度は下記の値を用いた（単位：ｇ／ｃｍ３）。

　結晶化度（％）＝｛ｄｃ（ｄ－ｄａ）／ｄ（ｄｃ－ｄａ）｝×１００

ここで、ｄｃ：完全結晶部分の密度、ｄａ：完全非晶部分の密度、ｄ：試料の密度
ポリエチレンテレフタレート樹脂：完全非晶部分の密度（ｄａ）＝１．３４、
　　　　　　　　　　　　　　　　完全結晶部分の密度（ｄｃ）＝１．４６
ポリエチレンナフタレート樹脂：完全非晶部分の密度（ｄａ）＝１．３２、　　　　　　　　　　　　　　　　完全結晶部分の密度（ｄｃ）＝１．４１ (2) Crystallinity Degree by Density Method The density of the film sample was measured at three points, and the average value was defined as the crystallinity degree. The resin component is a mixture of completely amorphous and completely crystalline, and the density is as described later, and the density of the sample is a value obtained by dividing the sum of the mass of each component constituting the sample by the sum of the volumes of each component. The crystallinity (weight ratio) of each resin was estimated based on the assumption that The sample density was measured according to the method according to JIS K-7112-1980 (density gradient tube method). The calculation formula of the degree of crystallinity is as follows, and the density of each component alone was as follows (unit: g / cm 3 ).

Crystallinity (%) = {dc (d-da) / d (dc-da)} × 100

Here, dc: density of completely crystalline portion, da: density of completely amorphous portion, d: density of sample polyethylene terephthalate resin: density of completely amorphous portion (da) = 1.34,
Density of complete crystal part (dc) = 1.46
Polyethylene naphthalate resin: density of completely amorphous part (da) = 1.32, density of completely crystalline part (dc) = 1.41
（３）表面結晶化度（ＡＴＲ法）
　延伸フィルムの一方の面（フィルムのいずれか一方の面がコロナ処理をされている場合には、非コロナ処理面）について、下記条件で全反射赤外吸収測定（ＦＴ－ＩＲＡＴＲ測定）を行い、１３４０ｃｍ－１付近に現れる吸収と、１４１０ｃｍ－１付近に現れる吸収の強度比（１３４０ｃｍ－１／１４１０ｃｍ－１）により結晶化度を算出した。ここで１３４０ｃｍ－１はエチレングリコールのＣＨ２（トランス構造）の変角振動による吸収であり、１４１０ｃｍ－１は結晶、配向とは無関係の吸収である。
（測定装置、条件）
ＦＴ－ＩＲ装置：Ｂｉｏ ＲａｄＤＩＧＩＬＡＢ社製「ＦＴＳ－６０Ａ／８９６」
１回反射ＡＴＲアタッチメント：ＳＰＥＣＡＣ社製「ｇｏｌｄｅｎ ｇａｔｅ ＭＫII」
内部反射エレメント：ダイヤモンド 
入射角：４５° 
分解能：４ｃｍ－１
積算回数：１２８回  (3) Surface crystallinity (ATR method)
Perform total reflection infrared absorption measurement (FT-IRATR measurement) on one side of the stretched film (non-corona treated side if any one side of the film is corona treated) under the following conditions, and absorption appears near 1340 cm -1, was calculated crystallinity by the intensity ratio of absorption appears near 1410cm -1 (1340cm -1 / 1410cm -1 ). Here, 1340 cm -1 is absorption due to bending vibration of CH 2 (trans structure) of ethylene glycol, and 1410 cm -1 is absorption unrelated to crystal and orientation.
(Measurement device, condition)
FT-IR device: "FTS-60A / 896" manufactured by Bio RadDIGILAB
One time reflection ATR attachment: SPECAC "golden gate MKII"
Internal reflection element: diamond
Incident angle: 45 °
Resolution: 4 cm -1
Integration count: 128 times
（４）鉛筆硬度
　ＪＩＳ　Ｋ　５６００－５－４：１９９９に準拠し、荷重７５０ｇ、速度１．０ｍｍ／ｓで測定し、変形の有無を目視確認した。変形が無いものをＯＫとした。５回測定し、ＯＫの評価が４回以上の鉛筆硬度を測定値とした。 (4) Pencil Hardness According to JIS K 5600-5-4: 1999, it was measured at a load of 750 g and a speed of 1.0 mm / s to visually confirm the presence or absence of deformation. It was OK if there was no deformation. It measured 5 times, and evaluation of OK made 4 or more times pencil hardness the measurement value.
　（ウレタン樹脂の重合）
　撹拌機、ジムロート冷却器、窒素導入管、シリカゲル乾燥管、及び温度計を備えた４つ口フラスコに、１，３－ビス（イソシアネートメチル）シクロヘキサン７２．９６質量部、ジメチロールプロピオン酸１２．６０質量部、ネオペンチルグリコール１１．７４質量部、数平均分子量２０００のポリカーボネートジオール１１２．７０質量部、及び溶剤としてアセトニトリル８５．００質量部、Ｎ－メチルピロリドン５．００質量部を投入し、窒素雰囲気下、７５℃において３時間撹拌し、反応液が所定のアミン当量に達したことを確認した。次に、この反応液を４０℃にまで降温した後、トリエチルアミン９．０３質量部を添加し、ポリウレタンプレポリマーＤ溶液を得た。次に、高速攪拌可能なホモディスパーを備えた反応容器に、水４５０ｇを添加して、２５℃に調整して攪拌混合しながら、イソシアネート基末端プレポリマーを添加して水分散した。その後、減圧下で、アセトニトリルおよび水の一部を除去することにより、固形分３５質量％の水溶性ポリウレタン樹脂（Ａ）を調製した。 (Polymerization of urethane resin)
In a four-necked flask equipped with a stirrer, a Dimroth condenser, a nitrogen inlet tube, a silica gel drying tube, and a thermometer, 72.96 parts by mass of 1,3-bis (isocyanatomethyl) cyclohexane, 12.60 dimethylolpropionic acid. A mass atmosphere, 11.74 parts by mass of neopentyl glycol, 112.70 parts by mass of polycarbonate diol having a number average molecular weight of 2000, 85.00 parts by mass of acetonitrile as a solvent and 5.00 parts by mass of N-methylpyrrolidone The mixture was stirred at 75 ° C. for 3 hours, and it was confirmed that the reaction solution reached a predetermined amine equivalent. Next, this reaction solution was cooled to 40 ° C., and then 9.03 parts by mass of triethylamine was added to obtain a polyurethane prepolymer D solution. Next, 450 g of water was added to a reaction vessel equipped with a high-speed stirable homodisper, adjusted to 25 ° C., and while stirring and mixing, an isocyanate group-terminated prepolymer was added and dispersed in water. Thereafter, a water-soluble polyurethane resin (A) having a solid content of 35% by mass was prepared by removing a part of acetonitrile and water under reduced pressure.
（水溶性カルボジイミド化合物の重合）
　温度計、窒素ガス導入管、還流冷却器、滴下ロート、および攪拌機を備えたフラスコにイソホロンジイソシアネート２００質量部、カルボジイミド化触媒の３－メチル－１－フェニル－２－ホスホレン－１－オキシド４質量部を投入し、窒素雰囲気下、１８０℃において１０時間撹拌し、イソシアネート末端イソホロンカルボジイミド（重合度＝５）を得た。次いで、得られたカルボジイミド１１１．２ｇ、ポリエチレングリコールモノメチルエーテル（分子量４００）８０ｇを１００℃で２４時間反応させた。これに水を５０℃で徐々に加え、固形分４０質量％の黄色透明な水溶性カルボジイミド化合物（Ｂ）を得た。（易接着層塗布液の調製） (Polymerization of water-soluble carbodiimide compound)
200 parts by mass of isophorone diisocyanate in a flask equipped with a thermometer, a nitrogen gas inlet tube, a reflux condenser, a dropping funnel, and a stirrer, and 4 parts by mass of 3-methyl-1-phenyl-2-phospholene-1-oxide as a carbodiimidization catalyst The mixture was stirred at 180 ° C. for 10 hours under a nitrogen atmosphere to obtain isocyanate-terminated isophorone carbodiimide (degree of polymerization = 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 gradually added to this at 50 ° C. to obtain a yellow transparent water-soluble carbodiimide compound (B) having a solid content of 40% by mass. (Preparation of easily adhesive layer coating solution)
　下記の塗剤を混合し、塗布液を作製した。
水　　　　　　　　　　　　　　　　　　　　　　　　　１６．９７質量部
イソプロパノール　　　　　　　　　　　　　　　　　　２１．９６質量部
ポリウレタン樹脂（Ａ）　　　　　　　　　　　　　　　　３．２７質量部
水溶性カルボジイミド化合物（Ｂ）　　　　　　　　　　　１．２２質量部
粒子　　　　　　　　　　　　　　　　　　　　　　　　　０．５１質量部
　（平均粒径４０ｎｍのシリカゾル、固形分濃度４０質量％）
界面活性剤　　　　　　　　　　　　　　　　　　　　　　０．０５質量部
　（シリコーン系、固形分濃度１００質量％） The following coating agents 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 sol with an average particle diameter of 40 nm, solid content Concentration 40% by mass)
Surfactant 0.05 parts by mass (Silicone-based, solid content concentration 100% by mass)
（ハードコート塗布液１０の調製）
　ペンタエリスリトールトリアクリレート（新中村化学工業社製、Ａ－ＴＭＭ－３、固形分濃度１００％）９５重量部、光重合開始剤（ＢＡＳＦジャパン社製、イルガキュア（登録商標）９０７、固形分濃度１００％）５重量部、レベリング剤（ビックケミージャパン社製、ＢＹＫ３０７、固形分濃度１００％）０．１重量部を混合し、トルエン／ＭＥＫ＝１／１の溶媒で希釈して、濃度４０％の塗布液１０を調製した。 (Preparation of Hard Coat Coating Solution 10)
95 parts by weight of pentaerythritol triacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., A-TMM-3, solid content concentration 100%), photopolymerization initiator (manufactured by BASF Japan Ltd., Irgacure (registered trademark) 907, solid content concentration 100% 5.) 5 parts by weight, 0.1 part by weight of a leveling agent (by BK, Inc., BYK 307, solid concentration 100%) is mixed, diluted with a solvent of toluene / MEK = 1/1, and coated at a concentration of 40% Solution 10 was prepared.
（ハードコート塗布液１１の調製）
　ウレタンアクリレート（共栄社化学社製、ＵＡ－３０６Ｈ、固形分濃度１００％）５０重量部、ペンタエリスリトールトリアクリレート（新中村化学工業社製、Ａ－ＴＭＭ－３、固形分濃度１００％）４５重量部、光重合開始剤（ＢＡＳＦジャパン社製、イルガキュア（登録商標）９０７、固形分濃度１００％）５重量部、レベリング剤（ビックケミージャパン社製、ＢＹＫ３０７、固形分濃度１００％）０．１重量部を混合し、トルエン／ＭＥＫ＝１／１の溶媒で希釈して、濃度４０％の塗布液１１を調製した。 (Preparation of Hard Coat Coating Solution 11)
50 parts by weight of urethane acrylate (manufactured by Kyoeisha Chemical, UA-306H, solid content concentration 100%), 45 parts by weight of pentaerythritol triacrylate (manufactured by Shin-Nakamura Chemical Co., A-TMM-3, solid content concentration 100%) 5 parts by weight of a photopolymerization initiator (manufactured by BASF Japan, Irgacure (registered trademark) 907, solid content concentration 100%), 0.1 part by weight of a leveling agent (by BK Chemie Japan, BYK 307, solid content concentration 100%) The mixture was mixed and diluted with a solvent of toluene / MEK = 1/1 to prepare a coating solution 11 having a concentration of 40%.
（ポリエチレンテレフタレートペレット（ａ）の調製）
　エステル化反応装置として、攪拌装置、分縮器、原料仕込口および生成物取り出し口を有する３段の完全混合槽よりなる連続エステル化反応装置を用い、ＴＰＡを２トン／ｈｒとし、ＥＧをＴＰＡ１モルに対して２モルとし、三酸化アンチモンを生成ＰＥＴに対してＳｂ原子が１６０ｐｐｍとなる量とし、これらのスラリーをエステル化反応装置の第１エステル化反応缶に連続供給し、常圧にて平均滞留時間４時間で、２５５℃で反応させた。次いで、上記第１エステル化反応缶内の反応生成物を連続的に系外に取り出して第２エステル化反応缶に供給し、第２エステル化反応缶内に第１エステル化反応缶から留去されるＥＧを生成ポリマー（生成ＰＥＴ）に対し８質量％供給し、さらに、生成ＰＥＴに対してＭｇ原子が６５ｐｐｍとなる量の酢酸マグネシウムを含むＥＧ溶液と、生成ＰＥＴに対してＰ原子が２０ｐｐｍのとなる量のＴＭＰＡを含むＥＧ溶液を添加し、常圧にて平均滞留時間１．５時間で、２６０℃で反応させた。次いで、上記第２エステル化反応缶内の反応生成物を連続的に系外に取り出して第３エステル化反応缶に供給し、さらに生成ＰＥＴに対してＰ原子が２０ｐｐｍとなる量のＴＭＰＡを含むＥＧ溶液を添加し、常圧にて平均滞留時間０．５時間で、２６０℃で反応させた。上記第３エステル化反応缶内で生成したエステル化反応生成物を３段の連続重縮合反応装置に連続的に供給して重縮合を行い、さらに、ステンレス焼結体の濾材（公称濾過精度５μｍ粒子９０％カット）で濾過し、極限粘度０．５８ｄｌ／ｇのポリエチレンテレフタレートペレット（ａ）を得た。 (Preparation of polyethylene terephthalate pellets (a))
As a esterification reactor, using a continuous esterification reactor consisting of a 3-stage complete mixing tank having a stirrer, a partial condenser, a feed port and a product outlet, TPA is 2 tons / hr and EG is TPA1. The amount of antimony trioxide is 2 mol per mol, and the amount of Sb atoms is 160 ppm with respect to the generated PET, and these slurries are continuously supplied to the first esterification reaction can of the esterification reaction device, and the pressure is normal pressure The reaction was carried out at 255 ° C. with an average residence time of 4 hours. Next, the reaction product in the first esterification reaction vessel is continuously taken out of the system, supplied to the second esterification reaction vessel, and evaporated from the first esterification reaction vessel in the second esterification reaction vessel. The EG solution containing 8% by mass of EG to the produced polymer (produced PET) and further containing Mg acetate in an amount of 65 ppm to the produced PET, and 20 ppm of P atoms to the produced PET The EG solution containing the amount of TMPA was added and allowed to react at 260.degree. C. under normal pressure for an average residence time of 1.5 hours. Then, the reaction product in the second esterification reaction vessel is continuously taken out of the system and supplied to the third esterification reaction vessel, and further contains TMPA in an amount of 20 ppm of P atom based on the produced PET The EG solution was added and reacted at 260 ° C. under normal pressure for an average residence time of 0.5 hours. The esterification reaction product produced in the third esterification reaction vessel is continuously supplied to a three-stage continuous polycondensation reaction apparatus to carry out polycondensation, and a filter material of a stainless sintered body (nominal filtration accuracy of 5 μm) The particles were filtered through 90% of particles to obtain polyethylene terephthalate pellets (a) having an intrinsic viscosity of 0.58 dl / g.
（ポリエチレンテレフタレートペレット（ｂ）の調製）
　ポリエチレンテレフタレートペレット（ａ）の製造工程について、第３エステル化反応の滞留時間を調節した他は同様の方法にて極限粘度を０．６２ｄｌ／ｇに調整し、ポリエチレンテレフタレートペレット（ｂ）を得た。 (Preparation of polyethylene terephthalate pellets (b))
The limiting viscosity was adjusted to 0.62 dl / g by the same method except that the residence time of the third esterification reaction was adjusted in the production process of polyethylene terephthalate pellets (a), to obtain polyethylene terephthalate pellets (b) .
（ポリエチレンテレフタレートペレット（ｃ）の調製）
　ポリエチレンテレフタレートペレット（ａ）を、回転型真空重合装置を用い、０．５ｍｍＨｇの減圧下、２２０℃で固相重合を行い、極限粘度０．６７ｄＬ／ｇのポリエチレンテレフタレートペレット（ｃ）を作製した。 (Preparation of polyethylene terephthalate pellets (c))
The polyethylene terephthalate pellets (a) were subjected to solid phase polymerization at 220 ° C. under a reduced pressure of 0.5 mmHg using a rotary vacuum polymerization apparatus to produce polyethylene terephthalate pellets (c) having an intrinsic viscosity of 0.67 dL / g.
（ポリエチレンテレフタレートペレット（ｄ）の調製）
　ポリエチレンテレフタレートペレット（ａ）を、回転型真空重合装置を用い、０．５ｍｍＨｇの減圧下、２２０℃で前記（ｃ）とは時間を変えて固相重合を行い、極限粘度０．７５ｄＬ／ｇのポリエチレンテレフタレートペレット（ｄ）を作製した。 (Preparation of polyethylene terephthalate pellets (d))
The polyethylene terephthalate pellet (a) is subjected to solid-phase polymerization using a rotary vacuum polymerization apparatus under reduced pressure of 0.5 mmHg at 220 ° C. while changing the time from (c) to a limiting viscosity of 0.75 dL / g. Polyethylene terephthalate pellets (d) were produced.
（ポリエチレンテレフタレートペレット（ｅ）の調製）
　ポリエチレンテレフタレートペレット（ａ）を、回転型真空重合装置を用い、０．５ｍｍＨｇの減圧下、２２０℃で前記（ｃ）、（ｄ）とは時間を変えて固相重合を行い、極限粘度０．８３ｄＬ／ｇのポリエチレンテレフタレートペレット（ｅ）を作製した。 (Preparation of polyethylene terephthalate pellets (e))
Solid phase polymerization of polyethylene terephthalate pellets (a) was carried out using a rotary vacuum polymerization apparatus under reduced pressure of 0.5 mmHg at 220 ° C. while changing time with the above (c) and (d), and the limiting viscosity was 0. A polyethylene terephthalate pellet (e) of 83 dL / g was produced.
（実施例１～５、比較例１～３）
　上記のポリエチレンテレフタレートペレット（ｃ）を１８０℃で８時間減圧乾燥（３Ｔｏｒｒ）した後、押出機に、ポリエチレンテレフタレートのペレット（a）を押出機にそれぞれ供給し、２８５℃で融解した。このポリマーを、ステンレス焼結体の濾材（公称濾過精度１０μｍ粒子９５％カット）で濾過し、口金よりシート状にして押し出した後、静電印加キャスト法を用いて表面温度３０℃のキャスティングドラムに接触させ冷却固化し、未延伸フィルムを作った。この未延伸フィルムを長手方向に８５℃で３．４倍に延伸した。前記易接着層塗布液をロールコート法でＰＥＴフィルムの片面に塗布した後、８０℃で２０秒間乾燥した。なお、最終（二軸延伸後）の乾燥後の塗布量が０．０６ｇ／ｍ2になるように調整した。この一軸延伸フィルムをテンターを用いて幅方向に９５℃で４．２倍延伸し、２３５℃にて５秒間熱処理し、表１の実施例１のポリエチレンテレフタレートフィルムを得た。 (Examples 1 to 5 and Comparative Examples 1 to 3)
The above polyethylene terephthalate pellets (c) were dried under reduced pressure (3 Torr) at 180 ° C. for 8 hours, and then the pellets (a) of polyethylene terephthalate were respectively fed to the extruder and melted at 285 ° C. This polymer is filtered with a filter material of a stainless steel sintered body (nominal filtration accuracy 10 μm particles 95% cut), extruded into a sheet form from a die and extruded, and then cast onto a casting drum with a surface temperature of 30 ° C. using electrostatic application casting. The film was brought into contact and solidified by cooling to form an unstretched film. This unstretched film was stretched 3.4 times at 85 ° C. in the longitudinal direction. The above easy-adhesion layer coating solution was applied to one side of a PET film by roll coating, and then dried at 80 ° C. for 20 seconds. In addition, it adjusted so that the application amount after drying of the last (after biaxial stretching) might be set to 0.06 g / m < 2 >. This uniaxially stretched film was stretched 4.2 times at 95 ° C. in the width direction using a tenter, and heat-treated at 235 ° C. for 5 seconds to obtain the polyethylene terephthalate film of Example 1 in Table 1.
　また、ポリエチレンテレフタレートペレット（ｂ）～（ｅ）を用いて、実施例１と熱処理温度及び熱処理時間を変更した他はほぼ同様の工程により、表１の実施例２～５及び比較例１～３のポリエチレンテレフタレートフィルムを得た。 Moreover, except using the polyethylene terephthalate pellets (b) to (e), the heat treatment temperature and the heat treatment time were changed to those of Example 1, and the steps were substantially the same as in Examples 1 to 5 and Comparative Examples 1 to 3 in Table 1. The polyethylene terephthalate film of
（実施例１－１）
　実施例１で得たポリエチレンテレフタレートフィルムの易接着層上にマイヤーバーを用いて、ハードコート塗布液１０を乾燥後の膜厚が５．０μｍになるように塗布し、８０℃で１分間乾燥させた後、紫外線を照射し（積算光量２００ｍＪ／ｃｍ２）、ハードコートフィルムを得た。 Example 1-1
The hard coat coating solution 10 is coated on the easily adhesive layer of the polyethylene terephthalate film obtained in Example 1 using a Mayer bar so that the film thickness after drying is 5.0 μm, and dried at 80 ° C. for 1 minute. Then, it was irradiated with ultraviolet light (integrated light amount: 200 mJ / cm 2 ) to obtain a hard coat film.
（実施例１－１～５－１、１－２、２－２及び比較例１－１～３－１）
　表２に記載した条件を採用し、実施例１－１と同様の方法にて、ハードコートフィルムを作製した。 (Examples 1-1 to 5-1, 1-2, and 2-2 and comparative examples 1-1 to 3-1)
A hard coat film was produced in the same manner as in Example 1-1, using the conditions described in Table 2.
　作製したハードコートフィルムを、２５μｍ厚の粘着層を介して、有機ＥＬモジュールに貼合し、フレキシブルディスプレイを作製した。ハードコートフィルムにより、外部衝撃から有機ＥＬモジュールを保護することができ、良好な視認性を得ることができた。 The produced hard coat film was bonded to the organic EL module through a 25 μm-thick adhesive layer to produce a flexible display. With the hard coat film, the organic EL module could be protected from external impact, and good visibility could be obtained.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
　本発明によれば、ハードコート層などを積層した場合に表面硬度が高くなるポリエステルフィルムを提供でき、本発明のポリエステルフィルムの表面にハードコート層を積層したハードコートフィルムは、フレキシブルディスプレイ等の表示体の表面保護フィルムとして用いられることにより、表示体表面の傷、衝撃、変形などに強く、デザイン性にも優れた表示体の提供を可能とした。 ADVANTAGE OF THE INVENTION According to this invention, the polyester film which surface hardness becomes high when laminating a hard-coat layer etc. can be provided, and the hard-coat film which laminated the hard-coat layer on the surface of the polyester film of this invention By being used as a surface protective film of the body, it has become possible to provide a display body which is resistant to scratches, impacts, deformation, etc. on the surface of the display body and is also excellent in design.

Claims (5)

  1. 　極限粘度が０．６０～１．０ｄＬ／ｇのポリエステルフィルムであって、密度法による結晶化度が４８％以上、かつＡＴＲ法によるポリエステルフィルム表面の結晶化度が１．２０以上であるフレキシブルディスプレイの表面保護フィルム用ポリエステルフィルム。 A flexible display having a limiting viscosity of 0.60 to 1.0 dL / g and having a crystallinity of 48% or more by density method and a crystallinity of 1.20 or more of the polyester film surface by ATR method Polyester film for surface protection film.
  2. 　厚みが２５～１８８μｍである請求項１に記載のフレキシブルディスプレイの表面保護フィルム用ポリエステルフィルム。 The polyester film for a surface protection film of a flexible display according to claim 1, which has a thickness of 25 to 188 μm.
  3. 　ポリエステルフィルムが２軸延伸ポリエステルフィルムであり、前記２軸延伸ポリエステルフィルムの少なくとも一方の面に易接着層を有する請求項１または２に記載のフレキシブルディスプレイの表面保護フィルム用ポリエステルフィルム。 The polyester film for a surface protection film of a flexible display according to claim 1 or 2, wherein the polyester film is a biaxially stretched polyester film, and an easily adhesive layer is provided on at least one surface of the biaxially stretched polyester film.
  4. 　請求項１～３のいずれかに記載のポリエステルフィルムの少なくとも一方の面にハードコート層を有するフレキシブルディスプレイの表面保護フィルム用ハードコートフィルム。 A hard coat film for a surface protection film of a flexible display having a hard coat layer on at least one surface of the polyester film according to any one of claims 1 to 3.
  5. 　請求項４に記載のハードコートフィルムを、表面保護フィルムとして用いている表示体。 A display using the hard coat film according to claim 4 as a surface protective film.
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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112724432A (en) * 2019-10-28 2021-04-30 Skc株式会社 Polyester film and flexible display device including the same
TWI726704B (en) * 2019-05-08 2021-05-01 南韓商Ｓｋｃ股份有限公司 Polyester film and flexible display device comprising the same
WO2021215349A1 (en) * 2020-04-22 2021-10-28 東洋紡株式会社 Polyester film and use thereof

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2019082834A1 (en) * 2017-10-24 2019-05-02 東洋紡株式会社 Polyester film to be used as surface protection film of flexible display

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002113834A (en) * 2000-10-06 2002-04-16 Toppan Printing Co Ltd Decorative sheet and a decorative material
JP2002347109A (en) * 2001-05-23 2002-12-04 Toray Ind Inc Biaxially stretched polyester film for molding process and manufacturing method therefor
WO2014021396A1 (en) * 2012-08-03 2014-02-06 東洋紡株式会社 Polyester film and method for producing same
JP2016002764A (en) * 2014-06-19 2016-01-12 日本合成化学工業株式会社 Laminate, use thereof, and production method thereof
JP2017523254A (en) * 2014-05-21 2017-08-17 デュポン テイジン フィルムズ ユー．エス．リミテッド パートナーシップ Coated polyester film
WO2018159285A1 (en) * 2017-03-02 2018-09-07 東洋紡株式会社 Polyester film as surface protective film for foldable display and application thereof

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4117572B2 (en) 2005-02-03 2008-07-16 東洋紡績株式会社 Optical laminated polyester film, hard coat film using the same, and plasma display panel filter using the same
JP4967479B2 (en) 2006-06-30 2012-07-04 東洋紡績株式会社 Optically easy-adhesive polyester film roll and hard coat film
JP5471419B2 (en) 2009-12-22 2014-04-16 東洋紡株式会社 Hard coat film for molding with protective film
JP2011184617A (en) 2010-03-10 2011-09-22 Toray Ind Inc Biaxially oriented polyester film
JP6011539B2 (en) 2012-08-21 2016-10-19 東レ株式会社 Biaxially oriented polyethylene terephthalate film and method for producing the same
WO2019082834A1 (en) * 2017-10-24 2019-05-02 東洋紡株式会社 Polyester film to be used as surface protection film of flexible display

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002113834A (en) * 2000-10-06 2002-04-16 Toppan Printing Co Ltd Decorative sheet and a decorative material
JP2002347109A (en) * 2001-05-23 2002-12-04 Toray Ind Inc Biaxially stretched polyester film for molding process and manufacturing method therefor
WO2014021396A1 (en) * 2012-08-03 2014-02-06 東洋紡株式会社 Polyester film and method for producing same
JP2017523254A (en) * 2014-05-21 2017-08-17 デュポン テイジン フィルムズ ユー．エス．リミテッド パートナーシップ Coated polyester film
JP2016002764A (en) * 2014-06-19 2016-01-12 日本合成化学工業株式会社 Laminate, use thereof, and production method thereof
WO2018159285A1 (en) * 2017-03-02 2018-09-07 東洋紡株式会社 Polyester film as surface protective film for foldable display and application thereof

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
TWI726704B (en) * 2019-05-08 2021-05-01 南韓商Ｓｋｃ股份有限公司 Polyester film and flexible display device comprising the same
CN112724432A (en) * 2019-10-28 2021-04-30 Skc株式会社 Polyester film and flexible display device including the same
WO2021215349A1 (en) * 2020-04-22 2021-10-28 東洋紡株式会社 Polyester film and use thereof
JP7447994B2 (en) 2020-04-22 2024-03-12 東洋紡株式会社 Polyester film and its uses

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