WO2008016173A1 - film multicouche à utiliser comme film de base d'une feuille d'amélioration de la luminance - Google Patents

film multicouche à utiliser comme film de base d'une feuille d'amélioration de la luminance Download PDF

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Publication number
WO2008016173A1
WO2008016173A1 PCT/JP2007/065467 JP2007065467W WO2008016173A1 WO 2008016173 A1 WO2008016173 A1 WO 2008016173A1 JP 2007065467 W JP2007065467 W JP 2007065467W WO 2008016173 A1 WO2008016173 A1 WO 2008016173A1
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WIPO (PCT)
Prior art keywords
film
coating layer
fine particles
laminated film
film according
Prior art date
Application number
PCT/JP2007/065467
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English (en)
Japanese (ja)
Inventor
Shinichiro Okada
Atsushi Oyamatsu
Original Assignee
Teijin Dupont Films Japan Limited
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
Priority claimed from JP2006210885A external-priority patent/JP2008036867A/ja
Priority claimed from JP2006210886A external-priority patent/JP4928188B2/ja
Application filed by Teijin Dupont Films Japan Limited filed Critical Teijin Dupont Films Japan Limited
Publication of WO2008016173A1 publication Critical patent/WO2008016173A1/fr

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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
    • B32B27/36—Layered products comprising a layer of synthetic resin comprising polyesters
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C55/00—Shaping by stretching, e.g. drawing through a die; Apparatus therefor
    • B29C55/02—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets
    • B29C55/10—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets multiaxial
    • B29C55/12—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets multiaxial biaxial
    • 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
    • C08J7/0427—Coating with only one layer of a composition containing a polymer binder
    • 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
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
    • B29K2067/00—Use of polyesters or derivatives thereof, as moulding material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
    • B29K2995/00—Properties of moulding materials, reinforcements, fillers, preformed parts or moulds
    • B29K2995/0012—Properties of moulding materials, reinforcements, fillers, preformed parts or moulds having particular thermal properties
    • B29K2995/0017—Heat stable
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2367/00—Characterised by the use of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Derivatives of such polymers
    • C08J2367/02—Polyesters derived from dicarboxylic acids and dihydroxy compounds

Definitions

  • the present invention relates to a laminated film used as a base film of a brightness enhancement sheet disposed in a liquid crystal display device in order to improve the display brightness of the liquid crystal display device.
  • the polyester film is used as a base film for optical members of flat panel display devices.
  • it is used for brightness enhancement sheets for liquid crystal display devices (generally called “prism lens sheets”), base films for antireflection films, and base films for electromagnetic shielding finolems for plasma displays.
  • liquid crystal display devices have increased in screen size and brightness, and the amount of heat generated from the light source has increased, making it necessary to suppress deformation of the optical member due to heat.
  • in-vehicle liquid crystal display devices are used at high temperatures in cars under hot weather, and internal optical members are exposed to high heat.
  • the brightness enhancement sheet is composed of a base film and a prism lens layer formed thereon.
  • This prism lens layer is formed by providing an ultraviolet curable resin containing no solvent on a base film in the shape of a prism lens with a mold and irradiating it with ultraviolet rays to cure. For this reason, the base film of the brightness enhancement sheet is not exposed to heat during the formation of the prism lens layer, and tends to bend when used in a high temperature environment.
  • this film has a very high heat shrinkage rate and can prevent thermal deflection at temperatures up to about 60 ° C, but it has absolutely no dimensional stability at high temperatures of about 78 ° C or higher. Insufficient and large thermal deflection occurs. This is because polyethylene terephthalate has a glass transition point of about 78 ° C, and at temperatures above this temperature, film deformation is governed by thermal contraction rather than thermal expansion.
  • a film for brightness-enhancing sheets in which the thermal shrinkage rate of the film is set within a certain range has been proposed.
  • This film has improved adhesion to the lens layer at high temperatures and reduced thermal distortion.
  • Japanese Patent Laid-Open No. 2 00 0-1 4 1 5 7 4 Japanese Patent Laid-Open No. 2 00 0-1 4 1 5 7 4.
  • blocking is very likely to occur and handling properties are poor.
  • it is necessary to stretch in the longitudinal direction by three-stage or four-stage multi-stage stretching, and a special longitudinal multi-stage stretching film forming facility is required, and a general sequential biaxial It is difficult to manufacture with a stretched film-forming facility.
  • a biaxially stretched polyester film in which the refractive index, film thickness, and spectral reflectance of the coating film are set within a certain range has been proposed, and this film has ultraviolet transmittance that can withstand fine pitch, continuous production, and large area. It is known that good adhesion to the lens layer can be obtained (Japanese Patent Laid-Open No. 2 0 06-1 3 7 0 4 6). However, this film has a high longitudinal heat shrinkage ratio, and when used in a high temperature environment, a large thermal deflection occurs, and blocking is likely to occur, and the film is inferior in the ringing property. Disclosure of the invention
  • two brightness enhancement sheets are generally used by being stacked in a position adjacent to another member such as a diffusion plate.
  • the conventional brightness enhancement sheet for example, for in-vehicle use, when used in a high temperature environment, the opposite surface of the prism lens of the brightness enhancement sheet (surface without the prism lens layer) force constitutes the liquid crystal display device Block with adjacent members. In the blocked area, the display surface appears whitish, and the display quality of the liquid crystal display device deteriorates.
  • the first problem of the present invention is that it is used as a base film for a brightness enhancement sheet, which has anti-blocking properties in a high temperature environment and can obtain high adhesion with the prism lens layer while maintaining high transparency. To provide laminated film.
  • the second problem of the present invention is that, even when used in a high temperature environment, there is little heat deflection, it has blocking resistance in a high temperature environment, and it has high adhesion with the prism lens layer while maintaining high transparency.
  • Another object of the present invention is to provide a laminated film used as a base film for a brightness enhancement sheet.
  • a laminated film including a polyester film and a coating layer provided on at least one side thereof
  • the coating layer consists of a binder resin and organic fine particles
  • the average particle size of the organic fine particles is 20 to: L 0 00 nm,
  • the average particle size of organic fine particles exceeds 3 times the coating layer thickness
  • the difference in refractive index between the organic fine particles and the binder resin is 0.03 or less.
  • the polyester constituting the polyester film in the present invention is a linear saturated polyester synthesized from an aromatic dibasic acid or an ester-forming derivative thereof and a diol or an ester-forming derivative thereof.
  • Specific examples of such polyesters include polyethylene terephthalate, polyethylene isophthalate, polybutylene terephthalate, and poly (1,4-sicylene xylene dimethylene terephthalate).
  • the polyester used for the polyester film may be a copolymer of these polyesters or a blend with other resins.
  • the above polyester is the main component (for example, 80 mol% or more of the component)
  • the combined component or the blend component is preferably a small proportion (for example, a component of 20 mol% or less).
  • polyethylene terephthalate is particularly preferable because it has a good balance between mechanical properties and optical properties.
  • the polyester film may contain a colorant, an antistatic agent, an antioxidant, a lubricant, and a catalyst, but it is preferable from the viewpoint of transparency that it does not contain internal fine particles.
  • the thickness of the polyester film is preferably from 25 to 3500 ⁇ , more preferably from 50 to obtain the strength necessary for the base film of the brightness enhancement sheet.
  • the laminated film of the present invention has a heat shrinkage in the longitudinal direction when heat-treated at 150 ° C. for 30 minutes, preferably 1.5 to 0.0%, more preferably 1.0 to 0.0%.
  • the glass transition temperature is abbreviated as T g.
  • the polyester film in the present invention preferably has the same vertical heat shrinkage rate as the laminated film.
  • the laminated film of the present invention preferably has a heat shrinkage rate in the transverse direction of 30 to 15 minutes when heat-treated at 150 ° C. for 30 minutes, preferably 1.0 to 0.5%, more preferably 0.5 to 1 3%. If it exceeds 1.0%, the thermal dimensional stability is inferior and thermal deflection deteriorates, which is not preferable. If it is less than 0.5%, distortion is likely to occur due to thermal expansion, which is not preferable.
  • the laminated film used as the base film of the brightness enhancement sheet of the present invention includes a coating layer on the polyester film.
  • the coating layer may be provided on one side or on both sides, and preferably provided on both sides.
  • the coating layer is composed of a binder resin and organic fine particles.
  • the binder resin is preferably 60% by weight or more, more preferably 60 to 94.9% by weight, particularly preferably 10% by weight per 100% by weight of the total composition constituting the coating layer. Or 6 5-8 9.9% by weight. If the binder resin is less than 60% by weight, the blocking property tends to be inferior, which is not preferable. 94. If it exceeds 9% by weight, the adhesion to the prism lens layer tends to be inferior, which is not preferable.
  • the prism lens layer that acts to improve brightness in the brightness improving sheet is generally formed using an energy curable resin, and usually using an ultraviolet curable acrylic resin.
  • the binder resin of the coating layer is preferably made of an acrylic resin.
  • the thickness of the coating layer is preferably 20 to 15 O nm, more preferably 30 to 120 nm, and particularly preferably 40 to 90 nm. If the thickness of the coating layer exceeds 1550 nm, blocking will occur and this is not preferable. If it is less than 20 nm, the adhesion with the prism lens layer provided on the coating layer tends to be inferior.
  • the refractive index of the acrylic resin is preferably 1.45 to 1.55, more preferably 1.46 to 1.53, particularly preferably 1.48 to 1. 5 is 1. If the refractive index of the acrylic resin exceeds 1.55, high ultraviolet transmittance cannot be obtained, and it is difficult to form a prism lens using an ultraviolet curable acrylic resin when manufacturing a brightness enhancement sheet. On the other hand, it is technically difficult to make it less than 1.45.
  • the light transmittance at a wavelength of 400 nm can be 90% or more by using this acrylic resin.
  • the film does not sufficiently transmit ultraviolet rays, and if an ultraviolet curable resin is used to form the prism lens layer, curing tends to be poor, and it is processed into a brightness enhancement sheet. Difficult to do.
  • the acrylic resin of the coating layer in the present invention has a glass transition point (Tg), preferably 20 to 80 ° C, more preferably 25 to 70 ° C. If the glass transition point is less than 20 ° C, the blocking resistance deteriorates, which is not preferable. On the other hand, if it exceeds 80 ° C, the film forming property deteriorates, and the oligomer precipitation sealing property decreases, which is preferable.
  • Tg glass transition point
  • the acrylic resin is preferably soluble or dispersible in water.
  • this acrylic resin for example, polymers and copolymers of acrylic monomers exemplified below can be used.
  • Acrylic monomers include alkyl acrylate and alkyl methacrylate (alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, 2-ethyl) Hexyl group, cyclohexyl group, etc.); Hydroxy-containing monomers such as 2-hydroxyethylenoacrylate, 2-hydroxychetinoremethacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate; Epoxy group-containing monomers such as glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether; atalyl acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid and salts thereof (sodium salt, potassium salt, ammonium salt Tertiary amin salt, etc.
  • alkyl groups include methyl, eth
  • Monomers containing a carboxy group or a salt thereof such as styrene sulfonic acid and its salts (such as sodium salt, strong salt, ammonium salt, tertiary amine salt, etc.); acrylic amide, methacrylate amide, N-alkyl Acrylic amide, N-alkyl methacrylamide, N, N-dialkyl acrylamide, N, N-dialkyl methacrylate (The aralkyl groups include methyl, ethyl, n-propyl, isopropyl, n —Ptyl group, Isoptyl group, t_butyl group, 2_ethylhexyl group, cyclohexyl group, etc.), N-alkoxy acrylamide, N-alkoxy methacrylamide, N, N-dialkoxy acrylamide , N, N-dialkoxymethacrylamide (as alkoxy groups, methoxy, ethoxy, butoxy, Monomers
  • Atharyl rosin is disclosed in, for example, Production Examples 1 to 3 of JP-A-63-3-7716. It can be produced according to the method described. That is, four Lofsco were charged with a predetermined amount of sodium lauryl sulfonate as a surface active agent and a fixed amount of cation exchange water station, and the temperature was raised to 60 ° C in a nitrogen stream, and then passed as a polymerization initiator. Add 0.5 part of ammonium sulfate and 0.2 part of sodium hydrogen nitrite and adjust the mixture of monomers constituting the talyl resin to a liquid temperature of 60 to 70 ° C over 3 hours. While dripping. The reaction can be continued with stirring while maintaining the same temperature range for 2 hours after the completion of the dropping, and then cooled to obtain an aqueous dispersion of an acrylic resin. (Crosslinking agent)
  • the coating layer in the present invention is preferably composed of an acrylic resin composition containing a crosslinking agent.
  • a crosslinking agent one or more of epoxy, oxazoline, melamine and isocyanate can be used. These may be used alone or in combination of two or more.
  • Epoxy cross-linking agents include, for example, polyepoxy compounds, gepoxy compounds
  • polyepoxy compounds include sorbitol, polyglycidyl ether, polyglycerol polyglycidyl ether, pentae. Lisli tonole poly glycidyl ether, diglyceryl polyglycidyl ether, triglycidyl tris (2-hydroxyxyl) isocyanate, glycerol polyglycidyl Mention may be made of ether and trimethylolpropane polyglycidyl ether.
  • diepoxy compound examples include neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidinole ether, resonoresin dig ricidino reetenole, ethylene glyconoresin glycidino reetenole, polyethylene glyconoresin glycidinore
  • diepoxy compound examples include ether, propylene dariconoresiglycidino ether, polypropylene glycol diglycidyl ether, and polytetramethylene glycol diglycidyl ether.
  • Examples of monoepoxy compounds include allylic glycidyl ether, 2-ethylhexyl glycidyl ether, and phenyldaricidyl ether. Can do.
  • Examples of the glycidylamine compound include N, N, ⁇ ,, ,, -tetraglycidyl 1m_xylylenediamine, 1,3-bis (N, N-diglycidylamino) cyclohexane.
  • a polymer containing an oxazoline group is preferably used as the oxazoline crosslinking agent. This can be produced by polymerizing an addition-polymerizable oxazoline group-containing monomer alone and copolymerizing with other monomers.
  • Addition polymerizable oxazoline group-containing monomers include, for example, 2-vinyl-2-oxazoline, 2-bule 4-methinole 2-oxazoline, 2-vininole 5-methyl-1-oxazoline, 2-isopropenyl 2-oxazoline, 2 —Isopropenyl 4-methinoleyl 2-oxazoline, 2-Isopropenyl-5-ethyl-2-oxazoline. These may be used alone or in combination of two or more. Of these, 2-isopropenyl-l-oxazoline is preferred because it is easily available industrially.
  • the other monomer used for copolymerization with the oxazoline group-containing copolymer may be any monomer that can be copolymerized with the addition-polymerizable oxazoline group-containing monomer.
  • alkyl acrylate, alkyl methacrylate (as alkyl group) Is a (meth) crylate such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, a 2-ethylhexyl group, or a cyclohexyl group.
  • Unsaturation power such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, styrene sulfonic acid and its salts (sodium salt, potassium salt, ammonium salt, tertiary amine salt, etc.) Rubonic acid; Unsaturated nitriles such as acrylonitrile and methatalonitrile; acrylic acid, L-amide, N-alkyl acrylamide, N-alkyl methacrylamide, N, N-dialkyl acrylamide, N, N-dialkyl methacrylate (alkyl groups include methyl, ethyl, n Unsaturated amides such as —propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, 2-ethylhexyl group, cyclohexyl group, etc .; Bier esters such as those obtained by adding polyalky
  • a, ⁇ -unsaturated monomer such as styrene, a-methylenostyrene, / 3 _ Mention may be made of unsaturated aromatic monomers. These monomers may be used alone or in combination of two or more.
  • melamine crosslinking agent a compound obtained by condensing a methylol melamine derivative obtained by condensing melamine and formaldehyde with a lower alcohol and etherified, and a mixture thereof are preferable.
  • the lower alcohol for example, methyl alcohol, ethyl alcohol, or isopropyl alcohol can be used.
  • methylol melamine derivatives include monomethylol melamine, dimethylol melamine, trimethylol melamine, tetramethylol melamine, pentamethylol melamine, and hexamethylol melamine.
  • isocyanate cross-linking agents include tolylene diisocyanate.
  • Diphenylmethane-1,4'-diisocyanate metaxylylene diisocyanate, hexamethylene-1,6-diisocyanate, 1,6-diisocyanate hexane, tolylene diisocyanate and hexanetriol adduct
  • Examples include isocyanate and metaphenylene diisocyanate.
  • the content of the crosslinking agent is preferably 5 to 30% by weight, more preferably 10 to 25% by weight, per 100% by weight of the composition of the coating layer. . If it is less than 5% by weight, the resistance to procking tends to deteriorate, which is preferable. On the other hand, if it exceeds 30% by weight, the coating film becomes very hard, and it tends to be whitish in the stretching process, resulting in poor transparency. (Organic fine particles)
  • the coating layer needs to contain organic fine particles in order to obtain blocking resistance in a high temperature environment.
  • organic fine particles include fine particles of acrylic resin, styrene resin, silicone resin, fluorine resin, benzoguanamine resin, phenol resin, and nylon resin. One of these may be used, or two or more may be used. Acrylic resin and fluororesin fine particles are preferred, and acrylic resin fine particles are particularly preferred.
  • the content of the organic fine particles in the coating layer is preferably 0.1 to 10% by weight per 100% by weight of the composition of the coating layer. If it is less than 0.1% by weight, it is not preferable because sufficient lubricity and scratch resistance cannot be obtained. On the other hand, if it exceeds 10% by weight, the cohesive force of the coating film becomes low and the adhesiveness is deteriorated.
  • the average particle size of the organic fine particles contained in the coating layer is 20 to 100 nm, preferably 20 to 400 nm, more preferably 40 to 3500 nm, still more preferably 150 to 3.0 nm, particularly preferably 180 nm to 2500 nm. If it is less than 20 nm, sufficient slipperiness and scratch resistance cannot be obtained, and procking resistance deteriorates. On the other hand, if it exceeds 100 000 nm, the organic fine particles easily fall off.
  • the average particle diameter of the organic fine particles needs to exceed 3 times the thickness of the coating layer, preferably more than 3 times and less than 10 times. If it is 3 times or less, the blocking property is inferior. On the other hand, if it exceeds 10 times, it tends to fall off during the production process or handling during processing, which is not preferable. Even if the average particle size of the organic fine particles is large, the organic fine particles are supported by the acrylic resin as one component of the binder when they are blended in the composition of the coating layer and applied to the film. It will not drop out.
  • the difference between the refractive index of the acrylic resin used as the binder component and the refractive index of the organic fine particles is 0.03 or less, preferably 0 ⁇ 02 or less, more preferably 0.01. It is as follows. When the difference in refractive index exceeds 0.03, light scattering in the coating film increases, haze increases, and high transparency cannot be maintained. (Production method)
  • the polyester film in the present invention can be produced by performing a relaxation heat treatment after biaxial stretching. This relaxation heat treatment is preferably performed by inserting blades in the vicinity of both ends of the film on the downstream side of the stretching zone of the tenter to separate the film from the clip gripping portion. Further, the polyester film in the present invention can also be produced by a simultaneous biaxial stretching method. Hereinafter, the method for producing a polyester film will be described in detail. 'First, the polyester is melt-extruded into a film, cooled and solidified with a casting drum to form an unstretched film, and this unstretched film is once in the longitudinal (longitudinal) direction at T g ⁇ (T g + 60) ° C.
  • Transversely stretched to obtain a 'sequentially biaxially stretched film', and if necessary, heat treatment is carried out in a tenter for 1 to 60 to 240 ° C for 1 to 60 seconds. It can be obtained by performing a relaxation heat treatment while shrinking 0% to 20% in the longitudinal and transverse directions at a temperature as low as 20 ° C.
  • a pantograph type or linear motor type tenter is used as the tenter, and relaxation heat treatment is performed by narrowing the clip interval in the vertical direction, but a tenter that cannot narrow the clip interval in the vertical direction is used. If it is, the blade is inserted in the vicinity of both ends of the film at the downstream side of the stretching zone of the tenter to separate the film from the clip gripping section, and the speed of the take-up roll is set to 0 to the maximum speed of the clip in the tenter.
  • the desired relaxation heat treatment can be performed by slowing down by 5%.
  • a polyester film having a heat shrinkage in such a range is obtained by melt-extruding polyester into a film shape and cooling and solidifying it with a casting drum to form an unstretched film.
  • This unstretched film is Tg ⁇ (Tg + 60) Simultaneously biaxially stretch in the longitudinal direction and the transverse direction at ° C so that the surface magnification is 6 to 25 times, preferably 10 to 20 times, and if necessary, further 180 to 2 4 0.
  • the film is less likely to come into contact with the roll, fine scratches or the like are less likely to occur on the film surface than in the method described above, which is advantageous for application to optical applications.
  • the relaxation heat treatment is specifically performed at the downstream side of the stretching zone of the tenter by inserting blades in the vicinity of both ends of the film to separate the film from the clip gripping portion, and to adjust the speed of the take-up roll. It can be suitably performed by making it 0 to 5% slower than the maximum speed of the inner clip.
  • the coating liquid used for coating the coating layer is preferably used in the form of an aqueous coating liquid such as an aqueous solution, an aqueous dispersion, or an emulsion to form the coating layer.
  • an antistatic agent, a colorant, a surfactant, and an ultraviolet absorber may be further blended.
  • the solid content concentration of the coating liquid used in the present invention is usually 20% by weight or less, preferably 1 to 10% by weight. If it is less than 1% by weight, the coatability on the polyester film may be insufficient. On the other hand, if it exceeds 20% by weight, the stability of the coating solution and the appearance of the coating layer may be deteriorated.
  • the application of the coating liquid to the polyester film can be carried out at any stage, but it is preferably carried out during the production process of the polyester film. In this case, the polyester film before orientation crystallization is completed It is preferable to apply.
  • the polyester film before the crystal orientation is completed is an unstretched film, a uniaxially oriented film in which the unstretched film is oriented in either the longitudinal direction or the transverse direction, and further in the longitudinal direction and the transverse direction.
  • This is a concept including a biaxially stretched film oriented at a low magnification in the two directions (a biaxially stretched film before the orientation crystallization is completed by finally redrawing in the machine direction or the transverse direction).
  • the coating liquid When applying the coating liquid to the film, physical treatment such as corona surface treatment, flame treatment, plasma treatment, etc. is applied to the film surface as a pretreatment to improve the coatability. It is preferable to add a surfactant as a wetting agent to the coating force. When the surfactant is added to the coating liquid, the amount is preferably 1 to 10% by weight per 100% by weight of the solid content of the coating liquid.
  • the surfactant promotes the wetting of the coating liquid on the polyester film, especially the aqueous coating liquid, and improves the stability of the coating liquid.
  • Surfactants include, for example, polyoxyethylene monofatty acid esters, sorbitan fatty acid esters, glycerin fatty acid esters, fatty acid metal stones, alkyl sulfates, alkyl sulfonates, alkyl sulfosuccinates, and other anion type, nonionic type surface activity An agent can be mentioned.
  • any known coating method can be applied. For example, a roll coating method, a gravure coating method, a roll brush method, a spray coating method, an air knife coating method, an impregnation method, and a curtain coating method can be applied. These may be applied alone or in combination.
  • Example 1 Example 1
  • the refractive index of one component of the binder was measured with an Abbe refractometer (sodium D line) after the coating material was dried and solidified at 90 ° C.
  • the refractive index of the fine particles varies depending on the refractive index of the fine particles dried at 90 ° C.
  • the refractive index of the coating layer was measured using a spectrophotometer (Shimadzu Corporation UV—310 PC) with a scan speed of 20 nm / min, slit width of 20 nm, and sampling pitch of 1. O nm. Under the conditions, the spectral reflectance at a wavelength of 6 3 3 nm was determined, the average refractive index in the plane direction of the film was determined using an Abbe refractometer (sodium D line), and
  • the haze value of the film was measured using a haze measuring device NDH-2000 manufactured by Nippon Denshoku Industries Co., Ltd.
  • the value of ⁇ 1's was evaluated according to the following criteria.
  • UV-310 I PC manufactured by Shimadzu Corporation
  • the light transmittance at a wavelength of 400 nm was measured under the conditions of a scanning speed of 200 nmZ, a slit width of 20 nm, and a sampling pitch of 1.0 nm.
  • the film was cut into small pieces, embedded with epoxy resin, and the film was cut into sections with a microtome to a thickness of 50 nm. This was stained with 2% osmic acid at 60 ° C for 2 hours. The cross section of the dyed film was observed with a transmission electron microscope (LEM-2000) at a magnification of 200,000, and the coating layer thickness was measured.
  • LEM-2000 transmission electron microscope
  • Average particle size The same measurement as the measurement of the thickness of the coating layer was performed, the particle diameter of 100 fine particles was measured, and the average value was taken as the average particle diameter.
  • Blocking resistance in high temperature environments (simply referred to as “blocking resistance” in the table)
  • a UV curable acryl resin having the following composition is poured into a mold in which a prism lens pattern is formed, and the coated surface of the polyester film obtained thereon is adhered to the resin side, and the polyester film surface side is adhered.
  • Purple from a distance of 30 cm Using an external lamp (irradiation intensity 80W cm , 6.4KW) for 30 seconds to cure the lunar effect, form a prism lens layer with an apex angle of 90 degrees, a pitch of 50 ⁇ m, and a height of 30 ⁇ .
  • a brightness enhancement sheet was obtained.
  • Neopentyl glycol modified trimethylolpropane diacrylate (R-604, manufactured by Nippon Kayaku Chemical Co., Ltd.)
  • acrylic resin The following were used as components for forming a coating liquid for providing a coating layer.
  • acrylic resin The following were used as components for forming a coating liquid for providing a coating layer.
  • This acrylic resin was produced as follows according to the method described in Production Examples 1 to 3 of JP-A 63-371 67. That is, 302 parts of ion exchange water was charged into a four-necked flask and heated to 60 ° C. in a nitrogen stream, and then ammonium persulfate was used as a polymerization initiator.
  • This polyester resin was produced as follows.
  • the temperature of the reaction system is gradually raised to 25 5 ° C in a polymerization kettle with high motor torque of the stirrer, the pressure inside the system is reduced to 1 mmHg, and a polycondensation reaction is performed.
  • a polyester resin was obtained. 25 parts of this polyester resin was dissolved in 75 parts of tetrahydrofuran, and 75 parts of water was added dropwise to the resulting solution under high-speed stirring at 1000 rpm to obtain a milky white dispersion. Subsequently, this dispersion was distilled under a reduced pressure of 20 mmHg to distill off tetrahydrofuran. An aqueous dispersion of a polyester resin was obtained.
  • Fine particle 1 Acrylore filler (average particle size: 220 nm)
  • Acrylic filler (average particle size: 130 nm)
  • the molten polyethylene terephthalate used did not contain fine particles as a lubricant.
  • the coated film is subsequently dried at 110 ° C, stretched 3.6 times at 140 ° C in the transverse direction, heat-set at 235 ° C, and then from 180 ° C to 90 ° C 3% relaxation heat treatment is performed laterally in the tenter while gradually cooling the film!
  • Example 1 After forming a coating film using the coating agent listed in Table 1 and heat-fixing it at 225 ° C, insert a blade near both ends of the film in the tenter to separate the film from the clip gripping part and take it off Thickness 1 2 5 ⁇ , coating layer thickness, as in Example 1 except that the roll speed was 2.5% slower than the clip speed in the tenter and heat treatment was relaxed at 1 85 ° C. A 60 nm laminated film was obtained.
  • a prism lens layer was formed on the obtained laminated film using an ultraviolet curable acrylic resin to obtain a temperature improving sheet.
  • Table 2 shows the evaluation results.
  • This coated film was subsequently dried at 95 ° C, stretched 3.4 times in the longitudinal direction and 3.6 times in the transverse direction at 110 ° C, and heat-set at 2 25 ° C.
  • the film was subjected to relaxation heat treatment at 190 ° C. in the longitudinal and width directions by 2.5% to obtain a laminated film having a thickness of 100 nm and a coating layer thickness of 60 nm.
  • a prism lens layer was formed on the obtained laminated film using an ultraviolet curable acrylic resin to obtain a brightness enhancement sheet.
  • Table 2 shows the evaluation results.
  • a laminated film was obtained in the same manner as in Example 1 except that a coating layer having a predetermined thickness was formed using the coating agent described in Table 1.
  • a prism lens layer was formed on the obtained laminated film using an ultraviolet curable acrylic resin to obtain a brightness enhancement sheet.
  • Table 2 shows the evaluation results.
  • the coating film could not be retained because the fine particles were too large, and dropped off during film handling, and the blocking resistance of the laminated film was very poor.
  • a laminated film was obtained in the same manner as in Example 2 except that a coating layer was formed using the coating agent described in Table 1 and the film thickness was 1 8 8. Table 2 shows the evaluation results. Furthermore, the obtained laminated film is pre-cured using an ultraviolet curable acrylic resin. A brightness enhancement sheet was obtained by forming a lens lens layer. Table 2 shows the evaluation results.
  • a polyester film was obtained in the same manner as in Example 1 except that the coating layer was not formed.
  • Table 2 shows the evaluation results.
  • the obtained polyester film was used as a base film, and a prism lens layer was formed thereon using an ultraviolet curable acryl resin to obtain a brightness enhancement sheet.
  • Table 2 shows the evaluation results.
  • the obtained brightness enhancement sheet had poor adhesion between the polyester film of the base film and the prism lens layer, and could not be used satisfactorily as a brightness enhancement sheet.
  • a laminated film used as a base film for a brightness enhancement sheet which has blocking resistance in a high temperature environment and can obtain high adhesion with a prism lens layer while maintaining high transparency.
  • a laminated film used as a base film of a sheet can be provided. Industrial applicability
  • the laminated film used for the base film of the brightness enhancement sheet of the present invention can be a brightness enhancement sheet by providing a prism lens layer on the coating layer.
  • This can be suitably used in a high-temperature environment, particularly as a large-screen, high-brightness liquid crystal display device or a vehicle-mounted liquid crystal display device.

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  • Chemical & Material Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Laminated Bodies (AREA)
  • Coating Of Shaped Articles Made Of Macromolecular Substances (AREA)

Abstract

La présente invention concerne un film multicouche à utiliser comme film de base d'une feuille d'amélioration de la luminance, qui comprend un film en polyester et une couche de revêtement formée sur au moins un côté du film en polyester. Ce film multicouche est caractérisé en ce que la couche de revêtement est composée d'une résine liante et de particules organiques ayant une taille de particule moyenne de 20 à 1000 nm, la taille de particule moyenne des particules organiques représente plus de trois fois l'épaisseur de la couche de revêtement, et la différence des indices de réfraction entre les particules organiques et la résine liante n'est pas supérieure à 0,03. Ce film multicouche ne souffre pas de déformation thermique même lorsqu'il est utilisé dans des environnements à température élevée et présente une résistance au blocage dans des environnements à température élevée.
PCT/JP2007/065467 2006-08-02 2007-08-01 film multicouche à utiliser comme film de base d'une feuille d'amélioration de la luminance WO2008016173A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP2006-210886 2006-08-02
JP2006-210885 2006-08-02
JP2006210885A JP2008036867A (ja) 2006-08-02 2006-08-02 輝度向上シート用ポリエステルフィルム
JP2006210886A JP4928188B2 (ja) 2006-08-02 2006-08-02 輝度向上シート用ポリエステルフィルム

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WO2008016173A1 true WO2008016173A1 (fr) 2008-02-07

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KR (1) KR101392061B1 (fr)
WO (1) WO2008016173A1 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2450188A1 (fr) * 2009-07-01 2012-05-09 Mitsubishi Plastics, Inc. Film polyester stratifié
EP2769842A4 (fr) * 2011-10-19 2015-06-24 Mitsubishi Plastics Inc Film de polyester
JP2017217832A (ja) * 2016-06-08 2017-12-14 東レ株式会社 積層フィルム
EP3698964A4 (fr) * 2017-10-20 2021-08-18 LINTEC Corporation Matériau de base pour films barrières aux gaz, film barrière aux gaz, élément pour dispositifs électroniques, et dispositif électronique

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9778510B2 (en) 2013-10-08 2017-10-03 Samsung Electronics Co., Ltd. Nanocrystal polymer composites and production methods thereof

Citations (4)

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Publication number Priority date Publication date Assignee Title
JP2000141574A (ja) * 1998-11-18 2000-05-23 Toray Ind Inc レンズシート用フィルム
JP2003251776A (ja) * 2002-03-04 2003-09-09 Teijin Dupont Films Japan Ltd Ｉｔｏ膜用易接着性ポリエステルフィルム
JP2004009362A (ja) * 2002-06-04 2004-01-15 Teijin Dupont Films Japan Ltd 配向ポリエステルフィルムおよびそれを用いた積層フィルム
JP2006137046A (ja) * 2004-11-11 2006-06-01 Toray Ind Inc レンズシート用積層二軸延伸ポリエステルフィルム

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000141574A (ja) * 1998-11-18 2000-05-23 Toray Ind Inc レンズシート用フィルム
JP2003251776A (ja) * 2002-03-04 2003-09-09 Teijin Dupont Films Japan Ltd Ｉｔｏ膜用易接着性ポリエステルフィルム
JP2004009362A (ja) * 2002-06-04 2004-01-15 Teijin Dupont Films Japan Ltd 配向ポリエステルフィルムおよびそれを用いた積層フィルム
JP2006137046A (ja) * 2004-11-11 2006-06-01 Toray Ind Inc レンズシート用積層二軸延伸ポリエステルフィルム

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2450188A1 (fr) * 2009-07-01 2012-05-09 Mitsubishi Plastics, Inc. Film polyester stratifié
EP2450188A4 (fr) * 2009-07-01 2013-03-20 Mitsubishi Plastics Inc Film polyester stratifié
EP2769842A4 (fr) * 2011-10-19 2015-06-24 Mitsubishi Plastics Inc Film de polyester
US9523000B2 (en) 2011-10-19 2016-12-20 Mitsubishi Plastics, Inc. Polyester film
JP2017217832A (ja) * 2016-06-08 2017-12-14 東レ株式会社 積層フィルム
EP3698964A4 (fr) * 2017-10-20 2021-08-18 LINTEC Corporation Matériau de base pour films barrières aux gaz, film barrière aux gaz, élément pour dispositifs électroniques, et dispositif électronique

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KR20090046884A (ko) 2009-05-11
KR101392061B1 (ko) 2014-05-07

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