JP2014097638A - Laminated film, optical laminated film, and display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated film which has an easy adhesion layer excellent in adhesion to a solventless resin layer and excellent in scratch resistance.SOLUTION: The present invention relates to a laminated film 22 characterized in that: it has a support 30 comprising a polyester and an easy adhesion layer 31 laminated on at least one surface of the support 30; the easy adhesion layer 31 contains a water-soluble polyoxyalkylene compound; the water contact angle of the surface of the easy adhesion layer 31 is 72° or less; and the content of the water-soluble polyoxyalkylene compound is 2 mass% or more based on the total solid content in the easy adhesion layer 31.

Description

  The present invention relates to a laminated film, an optical laminated film, and a display device. Specifically, the present invention comprises a laminated film having an easy-adhesive layer containing a predetermined amount or more of water-soluble polyoxyalkylene and having a water contact angle of a predetermined angle or less, an optical laminated film comprising the laminated film, The present invention relates to a display device including the optical laminated film.

  Polyester films are excellent in transparency, dimensional stability, heat resistance, chemical resistance, and the like, and are therefore preferably used in display devices such as liquid crystal displays, plasma displays, and touch panel displays. When a polyester film is used in a display device, it may be used as an optical laminated film by being bonded to a functional film such as a prism sheet, a lens sheet, or a diffusion sheet. However, since the polyester film itself has no adhesiveness, a film layer such as an easy-adhesion layer is laminated on the polyester film, and another film is bonded through the film layer.

  For example, Patent Document 1 discloses a laminated film in which an easy adhesion layer is formed on a polyester film. Here, the easy-adhesion layer is composed of components mainly composed of a water-soluble copolymer polyester and oxidized wax or natural wax. Thereby, it is said that the laminated film excellent in slipperiness and excellent in scratch resistance can be obtained.

  Patent Document 2 discloses a laminated film having an easy adhesion layer containing a urethane resin having a polycarbonate structure and a crosslinking agent. Here, it has been proposed to improve the adhesion of an easy-adhesion layer to a solventless UV curable resin layer or the like by incorporating a specific component such as a urethane resin or a crosslinking agent in the easy-adhesion layer.

JP 7-268117 A JP 2009-220376 A

  However, although the easy-adhesion layer of Patent Document 1 is excellent in adhesion to a solvent-type resin layer, there is a problem that adhesion to a solvent-free resin layer is not sufficient. When the easy-adhesion layer of Patent Document 1 is adhered to a solventless resin layer and placed in a high-temperature and high-humidity environment, the adhesion between the easy-adhesion layer and the resin layer decreases due to the occurrence of wax crying or the like. This has been clarified by the study of the present inventors.

  In addition, the easy-adhesion layer of Patent Document 2 has improved the adhesiveness of the easy-adhesion layer to a solventless UV curable resin layer to some extent, but the adhesiveness to the solventless low-elasticity resin is not sufficient, There was a need for further improvements. Furthermore, since the easy-adhesion layer of Patent Document 2 has poor slipperiness, there is a problem that the surface of the laminated film is easily damaged.

  Accordingly, the present inventors provide a laminated film having an easy-adhesive layer excellent in adhesion to a solventless resin layer and excellent in scratch resistance, in order to solve such problems of the prior art. The study was advanced for the purpose.

As a result of earnest studies to solve the above problems, the inventors of the present application, in a laminated film having a support and an easy-adhesion layer, contain a predetermined amount or more of a water-soluble polyoxyalkylene in the easy-adhesion layer, It has been found that by setting the water contact angle on the surface of the easy-adhesion layer to a predetermined angle or less, a laminated film having excellent adhesion to a solventless resin layer and excellent scratch resistance can be obtained.
Specifically, the present invention has the following configuration.

[1] A support made of polyester and an easy adhesion layer laminated on at least one surface of the support, the easy adhesion layer containing a water-soluble polyoxyalkylene compound, and the easy adhesion layer The water contact angle of the surface is 72 ° or less, and the content of the water-soluble polyoxyalkylene compound is 2% by mass or more based on the total solid content in the easy-adhesion layer. Laminated film.
[2] The laminated film according to [1], wherein the water-soluble polyoxyalkylene compound is at least one selected from polyethylene glycol, polypropylene glycol, and a copolymer of polyethylene glycol and polypropylene glycol.
[3] The optical system according to [1] or [2], wherein the content of the water-soluble polyoxyalkylene compound is 2 to 30% by mass with respect to the total solid content in the easy-adhesion layer. Laminated film.
[4] The water contact angle of the surface of the easy-adhesion layer when the storage process is performed for 240 hours at 65 ° C. and a relative humidity of 95% is R _1, and the surface of the easy-adhesion layer before the storage process is The laminated film according to any one of [1] to [3], wherein R ₂ -R ₁ is 5 ° or less when the water contact angle is R ₂ .
[5] The laminated film according to any one of [1] to [4], wherein the easy-adhesion layer contains at least one selected from a polyester resin, a polyurethane resin, and an acrylic resin.
[6] An optical laminated film, wherein an optical functional layer is laminated facing the easy-adhesion layer of the laminated film according to any one of [1] to [5].
[7] The optical laminated film as described in [6], wherein the optical functional layer is a prism layer.
[8] The optical laminated film as described in [6] or [7], wherein the optical functional layer is a UV curable resin and has an elastic modulus of 5 to 200 MPa.
[9] A display device on which the optical laminated film according to any one of [6] to [8] is mounted.
[10] A method for producing a laminated film, wherein a coating liquid for forming an easy-adhesion layer is applied to at least one surface of a support made of polyester, and then dried. The water contact angle on the surface of the easy-adhesion layer is 72 ° or less, and the content of the water-soluble polyoxyalkylene compound is based on the total solid content in the easy-adhesion layer. On the other hand, the manufacturing method of the laminated film which is 2 mass% or more.
[11] Applying a coating liquid for forming an optical functional layer on the surface of the easy-adhesion layer of the laminated film according to any one of [1] to [5], and then irradiating with an active energy ray to cure. A method for producing an optical laminated film.

  According to this invention, a laminated film with high adhesiveness to a solventless resin layer can be obtained by setting the easy-adhesion layer to the above configuration. Furthermore, the laminated film of the present invention is a solvent-free UV curable resin layer, and can exhibit high adhesion to a resin layer composed of a low elastic resin.

  Moreover, according to this invention, since it is possible to ensure the slipperiness of the laminated film by setting the easy-adhesion layer to the above configuration, it is possible to prevent the laminated film from being damaged. That is, the laminated film according to the present invention has excellent scratch resistance.

FIG. 1 is a cross-sectional view of an optical laminated film obtained by further laminating a prism layer on the laminated film according to the present invention.

  Hereinafter, the present invention will be described in detail. The description of the constituent elements described below may be made based on representative embodiments and specific examples, but the present invention is not limited to such embodiments. In the present specification, a numerical range expressed using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.

(Laminated film)
The laminated film according to the present invention includes a support made of polyester and an easy adhesion layer laminated on at least one surface of the support. The easy adhesion layer contains water-soluble polyoxyalkylene, and the content of the water-soluble polyoxyalkylene is 2% by mass or more with respect to the total solid content in the easy adhesion layer. Moreover, the water contact angle of the surface of an easily bonding layer is 72 degrees or less.

This invention can improve the adhesiveness of a solventless type resin layer and an easily bonding layer by setting an easily bonding layer as the said structure. Here, the solventless resin layer refers to a resin layer in which a solvent is not used in the coating solution for forming the resin layer and is cured by irradiation with active energy rays such as ultraviolet rays. .
The laminated film of the present invention is a solvent-free UV curable resin layer, and has excellent adhesion to a resin layer composed of a low elastic modulus resin having an elastic modulus of 5 to 200 MPa. Have. The prism layer is often composed of a solventless resin layer, and is preferably formed of a soft material such as a low elastic modulus resin and elastically deformed. The low elastic modulus resin is preferably used in a sheet-like display device and the like because it can return to its original shape after being deformed by an external stress. The laminated film of the present invention has good adhesion to such a prism layer.

  Furthermore, this invention can make the surface state of an easily bonding layer smooth by making an easily bonding layer into the said structure, and has the outstanding slipperiness. Thereby, the laminated film can have excellent scratch resistance. The laminated film having good scratch resistance does not damage the prism layer laminated on the easy adhesion layer, and can also prevent the easy adhesion layer itself from being damaged. Further, since scratches due to rubbing can be suppressed, the defective product rate due to scratches can be reduced, and the manufacturing efficiency can be increased. Furthermore, it is possible to prevent the laminated film from being damaged during storage and transportation after winding the laminated film, and handling becomes easy.

(Easily adhesive layer)
As shown in FIGS. 1A and 1B, the easy adhesion layer 31 is provided between the support 30 and the prism layer 21. The easy-adhesion layer 31 is provided on at least one surface of the support 30 in order to improve the adhesion of the support 30 to the prism layer 21 and to increase the adhesion with the prism layer 21. The easy adhesion layer may be a single layer as shown in FIG. 1 (a), or the first easy adhesion layer 31 and the second easy adhesion layer 32 as shown in FIG. 1 (b). A laminated structure of two or more layers having When the easy adhesion layer has a laminated structure of two or more layers, it is preferable that the first easy adhesion layer 31 in contact with the prism layer 21 has the configuration of the present invention.

  The easy adhesion layer contains a water-soluble polyoxyalkylene compound. The water-soluble polyoxyalkylene compound can be obtained by adding alkylene oxide to a compound having a hydroxy group. Preferable examples of the alkylene oxide include ethylene oxide or propylene oxide, or a mixture thereof.

Examples of the water-soluble polyoxyalkylene compound used in the present invention include polyethylene glycol (PEG), polypropylene glycol (PPG), polyhydric alcohols or ethylene oxide adducts of polyhydric phenols, polyhydric alcohols or polyhydric phenols. Examples include ethylene oxide / other alkylene oxide co-adducts. Among these, the water-soluble polyoxyalkylene compound is preferably at least one selected from polyethylene glycol, polypropylene glycol, and a copolymer of polyethylene glycol and polypropylene glycol.
Commercially available products include, for example, PEG # 200, PEG # 300, PEG # 400, PEG # 600, PEG # 1000, PEG # 1500, PEG # 4000, PPG # 700, Unilube 70DP-950B, Unilube 50TG-32 (Sun Oil Co., Ltd.), EBECRYL-11 (Daicel Cytec Co., Ltd.), and the like.

  The content rate of a water-soluble polyoxyalkylene compound is 2 mass% or more with respect to the total solid content in an easily bonding layer. In the present invention, by containing 2% by mass or more of the water-soluble polyoxyalkylene compound with respect to the total solid content in the easy-adhesion layer, the adhesiveness to the solventless resin layer can be enhanced, and easy The scratch resistance of the adhesive layer can be increased.

  Moreover, the content rate of a water-soluble polyoxyalkylene compound should just be 2 mass% or more with respect to the total amount of solids in an easily bonding layer, and it is preferable that it is 30 mass% or less. The content of the water-soluble polyoxyalkylene compound is preferably 3% by mass or more, and more preferably 4% by mass or more. Moreover, it is preferable that the content rate of a water-soluble polyoxyalkylene compound is 30 mass% or less, it is preferable that it is 25 mass% or less, and it is more preferable that it is 20 mass% or less. By setting the content of the water-soluble polyoxyalkylene compound within the above range, the adhesion to the solventless resin layer can be more effectively enhanced. Furthermore, it is possible to increase the slipperiness of the easy-adhesive layer and to improve the scratch resistance.

In this invention, the water contact angle of the surface of an easily bonding layer is 72 degrees or less. The water contact angle on the surface of the easy adhesion layer may be 72 ° or less, preferably 71 ° or less, and more preferably 70.5 ° or less.
In this invention, the adhesiveness to a solventless type resin layer can be improved by making the water contact angle of an easily bonding layer into the said range. Furthermore, it is a solventless UV curable resin layer, and can exhibit excellent adhesiveness even to a resin layer composed of a low elastic resin having an elastic modulus of 5 to 200 MPa.

Furthermore, even when the easy adhesion layer is placed in a high temperature and high humidity environment, it is preferable that the rate of change in the water contact angle on the surface of the easy adhesion layer is small. When the easy contact layer according to the present invention is stored at a temperature of 65 ° C. and a relative humidity of 95% for 240 hours when the water contact angle is R ₁ and the water contact angle before storage is R ₂ , R ₂ −R ₁ (Δwater contact angle) is preferably 5 ° or less. R ₂ -R ₁ is preferably 5 ° or less, more preferably 3 ° or less, still more preferably 2 ° or less, and particularly preferably 1 ° or less. In this invention, the laminated | multilayer film excellent in heat-and-moisture resistance can be obtained by making R < ₂ > -R < ₁ > into the said range. Even when the laminated film of the present invention is used in a high-temperature and high-humidity environment, it can exhibit good adhesion over a long period of time.

  In addition to the water-soluble polyoxyalkylene compound, a suitable material is preferably mixed in the easy-adhesion layer as long as the effects of the present invention are not impaired. For example, the easy-adhesion layer can contain a binder, fine particles, a crosslinking agent, and an additive.

The binder used for the easy adhesion layer is not particularly limited, but is preferably at least one of a polyester resin, a polyurethane resin, an acrylic resin, a styrene butadiene copolymer, and a polyolefin resin from the viewpoint of adhesion. It is preferable to contain at least one selected from polyester resins, polyurethane resins and acrylic resins. In addition, a binder having water solubility or water dispersibility is particularly preferably used from the viewpoint that the load on the environment is small.
Commercially available products include, for example, plus coat series such as plus coat Z592 (manufactured by Kanayo Chemical Co., Ltd.) as polyester resin, and superflex series such as superflex 150HS as polyurethane resin (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.). Examples of the acrylic resin include Jurimer series (manufactured by Toagosei Co., Ltd.) such as Jurimer ET-410.

The easy adhesion layer may appropriately contain organic or inorganic fine particles. In addition, the easy-adhesion layer can contain metal oxide particles that exhibit conductivity by electronic conduction. As the metal oxide particles, general metal oxides can be used. For example, ZnO, TiO ₂ , SnO ₂ , Al ₂ O ₃ , In ₂ O ₃ , MgO, BaO, MoO ₃ , ZrO ₂ , CeO. ₂ , Nb ₂ O ₅ , a composite oxide thereof, or a metal oxide containing a small amount of a different element in addition to these metal oxides. Of these metal oxides, SnO ₂ , ZnO, TiO ₂ , and In ₂ O ₃ are preferable, and SnO ₂ is particularly preferable. Instead of the metal oxide particles that exhibit conductivity by electronic conduction, a π-electron conjugated conductive polymer such as polythiophene may be included.

The surface resistance of the easy-adhesion layer is adjusted to 10 ¹² Ω / □ or less by adding either metal oxide particles that exhibit conductivity by electronic conduction or π-electron conjugated conductive polymers to the easy-adhesion layer. The Thereby, the optical laminated film can obtain sufficient antistatic properties and can prevent dust and dirt from adsorbing.

Further, for the purpose of adjusting the refractive index of the easy-adhesion layer, the easy-adhesion layer may contain metal oxide particles. As the metal oxide, those having a high refractive index such as SnO ₂ , ZrO ₂ , ZnO, TiO ₂ , CeO ₂ , and Nb ₂ O ₅ are preferably used. This is because the higher the refractive index, the more the refractive index can be changed.

  The particle diameter of the metal oxide fine particles is preferably in the range of 1 nm to 50 nm, particularly preferably in the range of 2 nm to 40 nm. The amount of the metal oxide fine particles may be determined according to the target refractive index, but when the easy-adhesive layer is 100%, the fine-adhesive layer has a range of 10-90%. It is preferable to be contained in.

The easy adhesion layer may contain a crosslinking agent. The cross-linking agent is used to further increase the adhesive force between the prism layer and the support. The cross-linking agent only needs to cause a cross-linking reaction when forming the easy-adhesion layer, and may not remain as a cross-linking agent in the easy-adhesion layer after the formation. That is, in the obtained laminated film, the crosslinking agent may be incorporated into a part of the crosslinked structure obtained by crosslinking other molecules, and the reaction or action as the crosslinking agent may already be completed.
Examples of the crosslinking agent include oxazoline compounds, carbodiimide compounds, epoxy, isocyanate, melamine (C ₃ N ₆ H ₆ ) and the like. As the crosslinking agent, an oxazoline compound or a carbodiimide compound is preferably used.
Commercially available products include, for example, Epocross series (manufactured by Nippon Shokubai Co., Ltd.) such as Epocross K-2020E as oxazoline compounds, and carbodilite series (Nisshinbo Corporation) such as carbodilite V-02-L2 as carbodiimide compounds. Etc.).

  As additives, matting agents, surfactants, preservatives and the like may be used as appropriate. The matting agent may be either organic or inorganic fine particles. For example, polymer fine particles such as polystyrene, polymethyl methacrylate, silicone resin, and benzoguanamine resin, and inorganic fine particles such as silica, calcium carbonate, magnesium oxide, and magnesium carbonate can be used. Among these, polystyrene, polymethyl methacrylate, and silica are preferable from the viewpoints of the effect of improving slipperiness and cost.

  Examples of the surfactant include known anionic, nonionic, cationic, fluorine, and silicone surfactants. The surfactant is described in, for example, “Surfactant Handbook” (Nishi Ichiro, Imai Seiichiro, Kasai Shozo Edition, Sangyo Tosho Co., Ltd., 1960). In particular, anionic and nonionic surfactants are preferably used.

  Examples of commercially available anionic surfactants include Lapisol A-90, Lapisol A-80, Lapisol BW-30, Lapisol B-90, Lapisol C-70 (trade name: manufactured by NOF Corporation), NIKKOL OTP. -100 (trade name: manufactured by Nikko Chemical Co., Ltd.), Kohakuur ON, Koracool L-40, Phosphanol 702 (Toho Chemical), Viewlight A-5000, Viewlight SSS (Sanyo Kasei) and the like. .

  Commercially available nonionic surfactants include, for example, NAROACTY CL-95, HN-100 (trade name: manufactured by Sanyo Chemical Industries, Ltd.), Risolex BW400 (higher alcohol industry), EMALEX ET-2020 (Japan Emulsion Stock) Company), Unilube 50MB-26, Nonion IS-4 (Nichio Corporation), and the like.

  Examples of commercially available fluorosurfactants include MegaFuck F171, F172, F173, F176, F177, F141, F141, F142, F143, F144, R30, F437, F475, and the like. F479, F482, F554, F780, F780, F781 (above, manufactured by DIC Corporation), Fluorard FC430, FC431, FC171 (above, manufactured by Sumitomo 3M Limited), Surflon S-382, SC- 101, SC-103, SC-104, SC-105, SC1068, SC-381, SC-383, SC-383, S393, KH-40 (above, manufactured by Asahi Glass Co., Ltd.), PF636, PF656 PF6320, PF6520, PF7002 (manufactured by OMNOVA) and the like.

  Specific examples of commercially available cationic surfactants include phthalocyanine derivatives (trade name: EFKA-745, manufactured by Morishita Sangyo Co., Ltd.), organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.), (meth) acrylic acid. (Co) polymer polyflow No. 75, no. 90, no. 95 (manufactured by Kyoeisha Chemical Co., Ltd.), W001 (manufactured by Yusho Co., Ltd.) and the like.

Examples of commercially available silicone surfactants include “Toray Silicone DC3PA”, “Toray Silicone SH7PA”, “Tore Silicone DC11PA”, “Tore Silicone SH21PA”, “Tore Silicone SH28PA” manufactured by Toray Dow Corning Co., Ltd. “Tole Silicone SH29PA”, “Tole Silicone SH30PA”, “Tole Silicone SH8400”, “TSF-4440”, “TSF-4300”, “TSF-4445”, “TSF-4460”, manufactured by Momentive Performance Materials, “TSF-4452”, “KP341”, “KF6001”, “KF6002” manufactured by Shin-Etsu Silicone Co., Ltd., “BYK307”, “BYK323”, “BYK330” manufactured by BYK Chemie, and the like can be mentioned.
Only one type of surfactant may be used, or two or more types may be combined.

  Examples of preservatives include sodium dehydroacetate, sodium benzoate, sodium pyridinethion-1-oxide, p-hydroxybenzoic acid ethyl ester, 1,2-benzothiazolin-3-one, sodium sorbate, sodium pentachlorophenol, etc. Can be mentioned.

  The easy-adhesion layer is usually formed by applying a coating solution in which a water-soluble polyoxyalkylene compound and other materials are mixed to at least one surface of a support and drying it. The thickness of the easy adhesion layer can be controlled by adjusting the coating amount of the coating solution for forming the easy adhesion layer. In order to exhibit high transparency and excellent adhesion, the thickness is more preferably constant in the range of 0.01 to 5 μm. By setting the thickness to 0.01 μm or more, the adhesion can be more reliably improved than when the thickness is less than 0.01 μm. By setting the thickness to 5 μm or less, it is possible to form the easy-adhesion layer with a more uniform thickness as compared with the case where the thickness is larger than 5 μm. Furthermore, it is possible to suppress an increase in the usage amount of the coating liquid, prevent an increase in the drying time, and suppress an increase in cost. A more preferable range of the thickness of the easy-adhesion layer is 0.02 μm to 3 μm. Moreover, an easily bonding layer may laminate | stack two or more layers in the said thickness range.

(Support)
As shown in FIGS. 2A and 2B, the support 30 is provided on the side opposite to the optical functional layer such as the prism layer 21 via the easy adhesion layer 31. The support 30 supports the optical functional layer. For example, when the support 30 is planned to be the optical laminated film 20, the support 30 supports the prism layer 21.

  The support is preferably a polyester film containing polyester. The kind in particular of polyester is not restrict | limited, A well-known thing can be used as polyester.

  The polyester is preferably a saturated polyester. Thus, by using a saturated polyester, a polyester film that is superior in terms of mechanical strength as compared with a film using an unsaturated polyester can be obtained. Examples of the polyester include 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.

  As polyester used for the support, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), polybutylene naphthalate (PBN), polyarylates, polyether sulfone, polycarbonate, polyether ketone, Polymer compounds such as polysulfone, polyphenylene sulfide, polyester liquid crystal polymer, triacetyl cellulose, cellulose derivatives, polypropylene, polyamides, polyimides, polycycloolefins, and the like can be used. Among these, PET, PEN, triacetyl cellulose, and cellulose derivatives are more preferable, and PET and PEN are particularly preferable.

  The polyester may be a homopolymer or a copolymer. Further, polyester may be blended with a small amount of other types of resin, such as polyimide. Further, as the polyester, a crystalline polyester capable of forming anisotropy when melted may be used.

  From the viewpoint of heat resistance and viscosity, the molecular weight of the polyester is preferably 5000 to 30000, more preferably 8000 to 26000, and particularly preferably 12,000 to 24,000. As the weight average molecular weight of the polyester, a value in terms of polymethyl methacrylate (PMMA) measured by gel permeation chromatography (GPC) using hexafluoroisopropanol as a solvent can be used.

  The polyester can be obtained by reacting a dicarboxylic acid or an ester-forming derivative thereof with a low molecular weight aliphatic diol or a high molecular weight diol. Examples of the dicarboxylic acid or its ester-forming derivative include terephthalic acid, isophthalic acid, orthophthalic acid, naphthalene dicarboxylic acid, paraphenylene dicarboxylic acid, dimethyl terephthalate, dimethyl isophthalate, dimethyl orthophthalate, dimethyl naphthalene dicarboxylate, and paraphenylene. And dimethyl dicarboxylate. These may be used alone or in combination of two or more.

Examples of the low molecular weight aliphatic diol include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, and 1,5-pentane. Examples include diol, 1,6-hexanediol, 1,4-cyclohexanedimethanol and the like. These may be used alone or in combination of two or more.
Examples of the high molecular weight diol include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyhexamethylene glycol and the like. These may be used alone or in combination of two or more.

  Examples of the crystalline polyester composed of the above components include polyethylene terephthalate, polybutylene terephthalate, polyhexamethylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, butanediol terephthalate polytetramethylene glycol copolymer, and the like. . These may be used alone or in combination of two or more. Particularly preferred among the aromatic polyesters described herein are those using terephthalic acid and naphthalenedicarboxylic acid as main components as dicarboxylic acids, and those having ethylene glycol and cyclohexanedimethanol as main components as diols. Preferred are polyethylene terephthalate, polyethylene naphthalate, and polycyclohexanedimethylene terephthalate, and more preferred are polyethylene terephthalate and polyethylene naphthalate.

  When the polyester used in the present invention is a polymer or copolymer obtained by a condensation reaction mainly comprising an aromatic dibasic acid or an ester-forming derivative thereof and a diol or an ester-forming derivative thereof, An aromatic dibasic acid or an ester-forming derivative thereof and a diol or an ester-forming derivative thereof can be produced by an esterification reaction or an ester exchange reaction and then a polycondensation reaction. Moreover, the carboxylic acid value and intrinsic viscosity of the polyester can be controlled by selecting the raw material and reaction conditions. In order to effectively advance the esterification reaction or transesterification reaction and polycondensation reaction, it is preferable to add a polymerization catalyst during these reactions.

  As a polymerization catalyst for polymerizing polyester, Sb-based, Ge-based, and Ti-based compounds are preferably used from the viewpoint of suppressing the carboxyl group content to a predetermined range or less, and Ti-based compounds are particularly preferable. In the case of using a Ti-based compound, an embodiment in which polymerization is performed by using the Ti-based compound as a catalyst in a range of 1 ppm to 30 ppm, more preferably 3 ppm to 15 ppm is preferable. When the proportion of the Ti-based compound is within the above range, the terminal carboxyl group can be adjusted to the following range, and the hydrolysis resistance of the polymer substrate can be kept low.

  Polyester can be synthesized by a known method. For example, polyester can be synthesized by a known polycondensation method or ring-opening polymerization method, and any of transesterification and direct polymerization can be applied.

  The polyester film is preferably biaxially stretched from the viewpoint of improving mechanical strength. A biaxially stretched polymer film can be obtained by stretching a long film of a polymer compound in two directions perpendicular to each other in the longitudinal direction and the width direction. Although a draw ratio is not specifically limited, Preferably it is the range of 1.5-7 times. If the draw ratio is less than 1.5 times, the mechanical strength may be insufficient. Conversely, if it exceeds 7 times, the thickness may not be uniform. Particularly preferable stretching directions and magnifications are in the range of 2 to 5 times in two directions orthogonal to each other. In the present invention, a biaxially stretched film of PET or PEN is particularly preferably used as a support from the viewpoint of elastic modulus and transparency.

  Further, at least one of the one surface and the other surface of the polyester film may be subjected to corona discharge treatment. One side and / or the other side of the support can be hydrophilized by corona discharge treatment to improve the wettability of various aqueous coating solutions.

  The polyester film preferably has a thickness of 30 to 350 μm, and more preferably has a thickness of 50 to 300 μm. When the thickness of the support is less than 30 μm, it is not preferable because it is difficult to handle due to lack of waist. On the other hand, when the thickness of the support exceeds 500 μm, it is difficult to reduce the size and weight of the display device, and it is disadvantageous in terms of cost.

(Optical function layer)
The optical functional layer has a function of concentrating light emitted from the light guide plate and the diffusion plate by arranging a large number of minute prisms in order to improve the luminance on the display surface. Examples of the optical functional layer include a micro optical functional layer, a prism layer, and a lenticular optical functional layer. Among these, a prism layer is particularly preferably used. In order to improve the luminance on the display surface, the optical functional layer includes a large number of minute prisms, and condenses light emitted from the light guide plate and the diffusion plate.

  2A and 2B show an optical laminated film 20 in which a prism layer 21 is further laminated on a laminated film 22 in which a support 30 and an easy adhesion layer 31 are laminated in order. The optical laminated film preferably has a transmittance of 70% to 100% for light having a wavelength of 340 nm in incident light when light is incident from the support side.

  The prism layer is preferably formed of a low elastic modulus resin having an elastic modulus of 5 to 200 MPa. The low elastic modulus resin is a soft material, and can be returned to its original shape after being deformed by an external stress. Therefore, it is preferably used for a sheet-like display device or the like. Examples of such a low elastic modulus resin include a resin group having a relatively long polyethylene oxide chain, a solvent-free type, and a functional group that is cured by a crosslinking reaction or a polymerization reaction when irradiated with active energy rays. Is used. The prism layer is obtained by irradiating these resins with active energy rays such as ultraviolet rays and curing them.

  As the active energy ray curable resin, it is preferable to use a bisphenol A diacrylate resin represented by the following structural formula (1). In the following structural formula (1), the average added mole number (n + m) is preferably 5 or more, more preferably 6 or more, and still more preferably 10 or more. The average number of added moles (n + m) is preferably 30 or less, and more preferably 26 or less. This is because if the average added mole number (n + m) exceeds 30, there is a problem that the front luminance of the backlight unit is lowered due to the influence of the decrease in the refractive index.

  The bisphenol A diacrylate resin represented by the structural formula (1) is preferably contained in an amount of 10% by mass or more, more preferably 20% by mass or more based on the total mass of the prism layer. preferable. By setting the content of the bisphenol A-based diacrylate resin within the above range, the elastic modulus of the prism layer can be set within a preferable range.

The active energy ray-curable resin may be used in combination with a resin other than the bisphenol A diacrylate resin.
As a commercial item, NK ester A-BPE-10, NK ester A-BPE-4, NK ester A-LEN-10 (made by Shin-Nakamura Chemical Co., Ltd.) etc. are mentioned, for example.

The prism layer is preferably formed in a later step on the easy-adhesion layer attached to the support. The prism layer may be formed by an embossing method or a cast polymerization method. Usually, a casting polymerization method with higher productivity than the method of pressing is used.
In the casting polymerization method, a film made of a UV curable compound that is cured with ultraviolet rays (UV) is usually formed into a predetermined shape, and the compound is cured with UV in a state in which the shape is maintained, whereby a predetermined cross-sectional shape is obtained. A plurality of prisms are formed into a prism layer. When the prism layer is formed by the cast polymerization method, generally, a monomer, oligomer, or polymer having a radical polymerizable double bond as a main component is used as a material, and a polymerization initiator is further contained. Examples of monomers and oligomers having radically polymerizable double bonds include acrylic monomers and acrylic oligomers.

  Examples of the polymerization initiator include phosphine compounds such as triazine compounds, oxadiazole compounds, and acylphosphine oxides (such as Lucirin TPO and IRGACURE 819 manufactured by BASF), oxime compounds such as hexaarylbiimidazole and oxime derivatives (IRGACURE manufactured by BASF). -OXE01, IRGACURE-OXE02, etc.), organic peroxides, thio compounds, ketone compounds, aromatic onium salts, ketoxime ethers, aminoacetophenone compounds (IRGACURE907, IRGACURE369, IRGACURE369, etc. manufactured by BASF), hydroxyacetophenone compounds (BASF) IRGACURE184, DAROCUR1173, IRGACURE500, IRGACURE295 , Such as IRGACURE127) and the like. From the viewpoint of mass productivity, the cast polymerization method is preferable to the mold pressing method, and the cast polymerization method using a UV curable compound is preferable among the cast polymerization methods.

  In general, the main emission wavelength of a metal halide lamp used for UV curing is in the range of 340 nm to 400 nm, and the main emission wavelength of a high-pressure mercury lamp is 365 nm. Further, the transmittance of an optical laminated film that requires transparency in the visible light region tends to be lower as the wavelength is shorter in the range of 340 nm to 400 nm. Therefore, it is preferable that the transmittance of light having a wavelength of at least 340 nm is 70 to 100%. In particular, in the entire range of 340 to 400 nm, the light transmittance is preferably 70 to 100%. When the transmittance of light having a wavelength of 340 nm is 70% or more, when a prism layer is provided by UV curing on one surface of the support, UV irradiated from the support using a metal halide lamp or a high-pressure mercury lamp is optical. Absorption by the laminated film can be prevented. Thereby, it can prevent that the intensity | strength of UV which can contribute to hardening for forming a prism layer falls. As a result, the efficiency of curing the prism layer can be increased. When the curing efficiency is lowered, it is necessary to lengthen the curing time until a predetermined cured state is reached, resulting in a problem that the productivity of the prism layer is lowered. In addition, when the curing time is not lengthened, the prism layer is insufficiently cured, so that the prism layer has insufficient scratch resistance.

(Optical laminated film)
The present invention relates to an optical laminated film in which an optical functional layer is laminated facing the easy adhesion layer of the laminated film described above.

In the optical laminated film of the present invention, the optical functional layer is preferably a prism layer. 2A and 2B illustrate an optical laminated film 20 in which an easy-adhesion layer 31, a prism layer 21 and / or an optical functional layer are further laminated in this order on the laminated film 22, as a preferred embodiment of the present invention. .
The prism layer is preferably made of a UV curable resin and having an elastic modulus of 10 to 200 MPa. The optical laminated film preferably has a transmittance of 70% to 100% for light having a wavelength of 340 nm in incident light when light is incident from the support side.

(Display device)
The display device includes an optical laminated film 20, a liquid crystal panel unit arranged on the prism layer 21 side of the optical laminated film 20, a light guide plate arranged on the support 30 side of the optical laminated film 20, and the like. A direct type backlight or the like can be used instead of the light guide plate. In addition, the display device may include a sheet such as a prism sheet, a microlens sheet, and a reflection sheet. Various combinations of various sheets and the like can be made according to the specifications required of the display device.

(Laminated film manufacturing method)
The method for producing a laminated film includes a step of first obtaining a support by extrusion of a molten polymer. Next, it is preferable to include a step of stretching the support in the biaxial direction. The stretching directions are preferably orthogonal to each other. Next, a coating solution containing a water-soluble polyoxyalkylene that is a raw material for the easy-adhesion layer is applied to at least one surface of the support to form a coating film on the film surface. Then, the laminated film which has an easily bonding layer and a support body is obtained by passing through a drying process. In addition, when making an easily bonding layer into a 2 layer structure, after apply | coating a 2nd layer, it is preferable to make it dry and harden | cure.

  There is no restriction | limiting in particular in the coating method of a coating liquid, For example, well-known methods, such as bar coater application and slide coater application, are used. As the solvent, water, toluene, methyl alcohol, isopropyl alcohol, methyl ethyl ketone, and the like, and aqueous and organic solvent-based coating solvents such as a mixed system thereof can be used. Among them, the method using water as a coating solvent is preferably used from the viewpoint of cost and ease of production.

  Next, a prism layer is formed on the film surface on the easy adhesion layer side of the laminated film. The prism layer is obtained by applying an ultraviolet curable resin for a prism member, pressing a mold for a prism sheet against the film surface of the coating film, and irradiating ultraviolet rays from the support side to cure the coating film. . Thereby, the optical laminated film provided with the laminated film and the prism layer can be obtained.

The features of the present invention will be described more specifically with reference to examples and comparative examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below.
In addition, about Examples 2-6 and Comparative Examples 1-4, only conditions different from Example 1 are described.

Example 1
(Production of support)
A support was prepared by the following procedure. First, polyethylene terephthalate (hereinafter referred to as PET) having an intrinsic viscosity of 0.64 polycondensed using a Ti compound as a catalyst was dried to a moisture content of 50 ppm or less. The dried PET was melted in an extruder set with a heater temperature in the range of 280-300 ° C. The melted PET was extruded from a die part onto a chill roll applied with an electrostatic force to obtain a band-shaped amorphous base. The obtained amorphous base was stretched 3.3 times in the longitudinal direction and then stretched 3.8 times in the width direction to obtain a support having a thickness of 250 μm.

(Preparation of easy adhesion layer)
After carrying out the corona discharge treatment under the condition of 730 J / m ² while carrying the support at a carrying speed of 60 m / min, the following coating solution A was applied by the bar coating method. Then, it dried at 145 degreeC for 1 minute, and produced the easily bonding layer. The composition of the coating liquid A is as follows.

(Coating liquid A)
Polyester resin aqueous dispersion 145.3 parts by mass (manufactured by Kyoyo Chemical Co., Ltd., plus coat Z592 solid content 25%)
95.6 parts by mass of polyurethane resin (Daiichi Kogyo Seiyaku Co., Ltd. Superflex SF150-HS solid content 38%)
Crosslinking agent (oxazoline compound) 14.4 parts by mass (Epocross K-2020E, solid content 40%, manufactured by Nippon Shokubai Co., Ltd.)
Surfactant A 27.8 parts by mass (manufactured by Sanyo Chemical Industries, Ltd., 1% aqueous solution of NAROACTY CL-95)
Surfactant B 11.5 parts by mass (1% aqueous solution of Rapisol B-90 manufactured by NOF Corporation)
Water-soluble polyoxyalkylene compound A 3.6 parts by mass (manufactured by NOF Corporation, PEG # 1000 solid content 100%)
Preservative 0.7 parts by mass (Daito Chemical Co., Ltd., 1,2-benzothiazolin-3-one, solid content 3.5% methanol solution)
Distilled water α part by mass (α: the amount was adjusted so that the whole coating solution A was 1000 parts by mass)

(Preparation of prism layer)
The following coating liquid for forming the prism layer (hereinafter referred to as prism layer coating liquid) PA was filled in a mold for forming a prism pattern. The prism layer forming coating solution contains a compound that is cured by ultraviolet rays. 3 seconds after the start of contact between the coating liquid and the adhesive layer, from the support side, press the adhesive layer coated film against the mold so that the adhesive layer surface of the adhesive layer coated film is in contact with the coating liquid PA on the mold. Curing was performed by irradiating with ultraviolet rays at 1000 mJ / cm ² . As a light source for irradiating ultraviolet rays, a metal halide lamp UVL-1500M2 manufactured by Ushio Electric Co., Ltd. was used. The multilayer film was peeled off from the mold to obtain an optical laminated film including a prism layer having a vertex angle of 90 °, a pitch of 60 μm, and a height of 30 μm, that is, a prism sheet.

(Prism layer coating solution PA)
The composition of the prism layer coating solution is as follows.
Bisphenol A-type diacrylate resin 57.0 parts by mass (manufactured by Shin-Nakamura Chemical Co., Ltd., NK ester A-BPE-10)
Bisphenol A type diacrylate resin 5.0 parts by mass (manufactured by Shin-Nakamura Chemical Co., Ltd., NK ester A-BPE-4)
35.0 parts by mass of ethoxylated o-phenylphenol acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., NK ester A-LEN-10)
Initiator 3 parts by mass (IRGACURE184)

  The following evaluation and measurement were performed on the obtained prism sheet. Each result is shown in Table 1.

(Evaluation method)
1. Evaluation of Adhesive Force Immediately after Production On the prism layer, eleven scratches were made on each side of the prism layer with a single blade razor to form 100 squares. After that, an adhesive tape (600 manufactured by 3M) was attached, and the top of the tape was completely rubbed with an eraser. Then, the adhesive force of the prism layer with respect to a support body was evaluated in five steps of the following A to E by obtaining the number of squares peeled off in a 90-degree direction with respect to a horizontal plane.
A: When there is no peeling B: When the number of peeled squares is 1 or more and less than 5 C: When the number of peeled squares is 5 or more and less than 15 D: When the number of peeled squares is 15 or more and less than 30 E: When the number of peeled-off cells is 30 or more The above A, B and C are acceptable levels on products, and D and E are unacceptable levels.

2. Evaluation of adhesive strength after thermo treatment Thermo treatment was performed on the prism sheet. The thermo treatment is a treatment that is left in an environment of high temperature and high humidity. In this evaluation, the treatment was left in an environment of 65 ° C. and a relative humidity of 95% for 240 hours. The adhesion strength was evaluated after the thermo treatment. The evaluation method and standard of the adhesive force after the thermo treatment are the same as the evaluation method and standard of the adhesive force immediately after the production.

3. Evaluation of scratch resistance of coating film The scratch resistance of the coating film was evaluated with an abrasion resistance tester (manufactured by Shinto Kagaku Co., Ltd.). Specifically, black paper (manufactured by FUJIFILM Corporation, SKBT3 90BIGO) is brought into contact with the coated surface, and a load of 3 kg per 30 mm × 25 mm is applied and a distance of 10 cm is rubbed at 100 cm / min. It was. After the rubbing test, scratches on the coating film surface were visually evaluated.
A: No scratches or very slight appearance B: Some scratches are seen C: Some scratches are seen
D: Slightly many scratches are observed E: Scratches are significantly observed.
The above A and B are acceptable levels on the product, and C, D, and E are unacceptable levels.

4). Measurement of coating surface contact Using a fully automatic contact angle meter (DM-701 model, manufactured by Kyowa Interface Science Co., Ltd.) The water contact angle was measured.

(Example 2)
A prism sheet was obtained in the same manner as in Example 1 except that the coating liquid A in Example 1 was replaced with the following coating liquid B. Table 1 shows the results of evaluation and measurement of the obtained prism sheet using the same method and standard as in Example 1. The composition of the coating liquid B is as follows.

(Coating solution B)
Polyester resin aqueous dispersion 145.3 parts by mass (manufactured by Kyoyo Chemical Co., Ltd., plus coat Z592 solid content 25%)
95.6 parts by mass of polyurethane resin (Daiichi Kogyo Seiyaku Co., Ltd. Superflex 150HS solid content 38%)
Crosslinking agent (oxazoline compound) 14.4 parts by mass (Epocross K-2020E, solid content 40%, manufactured by Nippon Shokubai Co., Ltd.)
Surfactant A 27.8 parts by mass (manufactured by Sanyo Chemical Industries, Ltd., 1% aqueous solution of NAROACTY CL-95)
Surfactant B 11.5 parts by mass (1% aqueous solution of Rapisol B-90 manufactured by NOF Corporation)
3.6 parts by mass of water-soluble polyoxyalkylene compound B (manufactured by NOF Corporation, PEG # 4000 solid content 100%)
Preservative 0.7 parts by mass (Daito Chemical Co., Ltd., 1,2-benzothiazolin-3-one, solid content 3.5% methanol solution)
Distilled water α parts by mass

(Example 3)
A prism sheet was obtained in the same manner as in Example 1 except that the coating liquid A in Example 1 was replaced with the following coating liquid C. Table 1 shows the results of evaluation and measurement of the obtained prism sheet using the same method and standard as in Example 1.

(Coating liquid C)
Polyester resin aqueous dispersion 145.3 parts by mass (manufactured by Kyoyo Chemical Co., Ltd., plus coat Z592 solid content 25%)
95.6 parts by mass of polyurethane resin (Daiichi Kogyo Seiyaku Co., Ltd. Superflex 150HS solid content 38%)
Crosslinking agent (oxazoline compound) 14.4 parts by mass (Epocross K-2020E, solid content 40%, manufactured by Nippon Shokubai Co., Ltd.)
Surfactant A 27.8 parts by mass (manufactured by Sanyo Chemical Industries, Ltd., 1% aqueous solution of NAROACTY CL-95)
Surfactant B 11.5 parts by mass (1% aqueous solution of Rapisol B-90 manufactured by NOF Corporation)
Water-soluble polyoxyalkylene compound C 3.6 parts by mass (manufactured by NOF Corporation PPG # 700 solid content 100%)
Preservative 0.7 parts by mass (Daito Chemical Co., Ltd., 1,2-benzothiazolin-3-one, solid content 3.5% methanol solution)
Distilled water α parts by mass

(Example 4)
A prism sheet was obtained in the same manner as in Example 1 except that the coating liquid A in Example 1 was replaced with the following coating liquid D. Table 1 shows the results of evaluation and measurement of the obtained prism sheet using the same method and standard as in Example 1.

(Coating solution D)
Polyester resin aqueous dispersion 145.3 parts by mass (manufactured by Kyoyo Chemical Co., Ltd., plus coat Z592 solid content 25%)
95.6 parts by mass of polyurethane resin (Daiichi Kogyo Seiyaku Co., Ltd. Superflex 150HS solid content 38%)
Crosslinking agent (oxazoline compound) 14.4 parts by mass (Epocross K-2020E, solid content 40%, manufactured by Nippon Shokubai Co., Ltd.)
Surfactant A 27.8 parts by mass (manufactured by Sanyo Chemical Industries, Ltd., 1% aqueous solution of NAROACTY CL-95)
Surfactant B 11.5 parts by mass (1% aqueous solution of Rapisol B-90 manufactured by NOF Corporation)
Water-soluble polyoxyalkylene compound D 3.6 parts by mass (Unilube 70DP-950B, solid content 100% manufactured by NOF Corporation)
Preservative 0.7 parts by mass (Daito Chemical Co., Ltd., 1,2-benzothiazolin-3-one, solid content 3.5% methanol solution)
Distilled water α parts by mass

(Example 5)
A prism sheet was obtained in the same manner as in Example 1 except that the coating liquid A in Example 1 was replaced with the following coating liquid E. Table 1 shows the results of evaluating and measuring the obtained prism sheet by the same method and standard as in Example 1.

(Coating fluid E)
Polyester resin aqueous dispersion 145.3 parts by mass (manufactured by Kyoyo Chemical Co., Ltd., plus coat Z592 solid content 25%)
95.6 parts by mass of polyurethane resin (Daiichi Kogyo Seiyaku Co., Ltd. Superflex 150HS solid content 38%)
Crosslinking agent (oxazoline compound) 14.4 parts by mass (Epocross K-2020E, solid content 40%, manufactured by Nippon Shokubai Co., Ltd.)
Surfactant A 27.8 parts by mass (manufactured by Sanyo Chemical Industries, Ltd., 1% aqueous solution of NAROACTY CL-95)
Surfactant B 11.5 parts by mass (1% aqueous solution of Rapisol B-90 manufactured by NOF Corporation)
3.6 parts by mass of water-soluble polyoxyalkylene compound E (manufactured by NOF Corporation, Unilube 50TG-32 solid content 100%)
Preservative 0.7 parts by mass (Daito Chemical Co., Ltd., 1,2-benzothiazolin-3-one, solid content 3.5% methanol solution)
Distilled water α parts by mass

(Example 6)
A prism sheet was obtained in the same manner as in Example 1 except that the coating liquid A in Example 1 was replaced with the following coating liquid F. Table 1 shows the results of evaluating and measuring the obtained prism sheet by the same method and standard as in Example 1.

(Coating fluid F)
Polyester resin aqueous dispersion 145.3 parts by mass (manufactured by Kyoyo Chemical Co., Ltd., plus coat Z592 solid content 25%)
95.6 parts by mass of polyurethane resin (Daiichi Kogyo Seiyaku Co., Ltd. Superflex 150HS solid content 38%)
Crosslinking agent (oxazoline compound) 14.4 parts by mass (Epocross K-2020E, solid content 40%, manufactured by Nippon Shokubai Co., Ltd.)
Surfactant A 27.8 parts by mass (manufactured by Sanyo Chemical Industries, Ltd., 1% aqueous solution of NAROACTY CL-95)
Surfactant B 11.5 parts by mass (1% aqueous solution of Rapisol B-90 manufactured by NOF Corporation)
Water-soluble polyoxyalkylene compound F 3.6 parts by mass (Daicel Cytec Co., Ltd. EBECRYL-11 solid content 100%)
Preservative 0.7 parts by mass (Daito Chemical Co., Ltd., 1,2-benzothiazolin-3-one, solid content 3.5% methanol solution)
Distilled water α parts by mass

(Example 7)
In the coating liquid A in Example 1, the prism sheet was obtained like Example 1 except the addition amount of the water-soluble polyoxyalkylene compound A having been 13.0 mass parts. Table 1 shows the results of evaluating and measuring the obtained prism sheet by the same method and standard as in Example 1.

(Example 8)
In the coating liquid A in Example 1, a prism sheet was obtained in the same manner as in Example 1 except that the amount of the water-soluble polyoxyalkylene compound A added was 19.5 parts by mass. Table 1 shows the results of evaluating and measuring the obtained prism sheet by the same method and standard as in Example 1.

Example 9
A prism sheet was obtained in the same manner as in Example 1 except that the amount of the water-soluble polyoxyalkylene compound A added in the coating liquid A in Example 1 was 25.4 parts by mass. Table 1 shows the results of evaluating and measuring the obtained prism sheet by the same method and standard as in Example 1.

(Comparative Example 1)
A prism sheet was obtained in the same manner as in Example 1 except that the coating liquid A in Example 1 was replaced with the following coating liquid G. Table 1 shows the results of evaluating and measuring the obtained prism sheet by the same method and standard as in Example 1.

(Coating liquid G)
Polyester resin aqueous dispersion 145.3 parts by mass (manufactured by Kyoyo Chemical Co., Ltd., plus coat Z592 solid content 25%)
95.6 parts by mass of polyurethane resin (Daiichi Kogyo Seiyaku Co., Ltd. Superflex 150HS solid content 38%)
Crosslinking agent (oxazoline compound) 14.4 parts by mass (Epocross K-2020E, solid content 40%, manufactured by Nippon Shokubai Co., Ltd.)
Surfactant A 27.8 parts by mass (manufactured by Sanyo Chemical Industries, Ltd., 1% aqueous solution of NAROACTY CL-95)
Surfactant B 11.5 parts by mass (1% aqueous solution of Rapisol B-90 manufactured by NOF Corporation)
12.1 parts by weight of wax (Canakyo Oil Dispersion Cellosol 524 solid content 30%, manufactured by Chukyo Yushi Co., Ltd.)
Preservative 0.7 parts by mass (Daito Chemical Co., Ltd., 1,2-benzothiazolin-3-one, solid content 3.5% methanol solution)
Distilled water α parts by mass

(Comparative Example 2)
A prism sheet was obtained in the same manner as in Example 1 except that the water-soluble polyoxyalkylene compound A was not added to the coating liquid A in Example 1. Table 1 shows the results of evaluating and measuring the obtained prism sheet by the same method and standard as in Example 1.

(Comparative Example 3)
In the coating liquid A in Example 1, a prism sheet was obtained in the same manner as in Example 1 except that the amount of the water-soluble polyoxyalkylene compound A added was 0.73 parts by mass. Table 1 shows the results of evaluating and measuring the obtained prism sheet by the same method and standard as in Example 1.

In Examples 1 to 9, the easy-adhesion layer contains a water-soluble polyoxyalkylene compound, and the content is 2% by mass or more based on the total solid content of the easy-adhesion layer. The water contact angle is 72 ° or less. For this reason, Examples 1-9 are good adhesiveness immediately after manufacture, and the adhesiveness after a thermo is also favorable, and is a pass level as a product. Furthermore, it turns out that Examples 1-9 are also excellent in the flaw resistance of an easily bonding layer. In particular, it can be seen that Examples 1 to 6 have good adhesion immediately after production, adhesion after thermostating, and excellent scratch resistance.
On the other hand, since Comparative Example 1 does not contain a water-soluble polyoxyalkylene compound and uses a wax dispersion, the water contact angle is as large as 79 °. For this reason, the adhesiveness immediately after manufacture and after thermostating is remarkably bad. Moreover, it turns out that scratch resistance is also inferior.
Moreover, since the comparative example 2 uses neither a water-soluble polyoxyalkylene compound nor a wax, the slipperiness is poor and the scratch resistance is remarkably deteriorated.
Comparative Example 3 contains a water-soluble polyoxyalkylene compound, but the content is 1% by mass, and in this case, it can be seen that the scratch resistance is not improved.

  ADVANTAGE OF THE INVENTION According to this invention, the laminated | multilayer film which has the adhesiveness layer excellent in the adhesiveness with respect to a solventless type resin layer and excellent in scratch resistance can be obtained. For this reason, this invention can be utilized effectively for a display apparatus etc., and industrial applicability is high.

20 optical laminated film 21 prism layer 22 laminated film 30 support 31 easy adhesion layer 32 easy adhesion layer

Claims (11)

A support made of polyester;
An easy adhesion layer laminated on at least one surface of the support,
The easy adhesion layer contains a water-soluble polyoxyalkylene compound,
The water contact angle of the surface of the easy adhesion layer is 72 ° or less,
The content rate of the said water-soluble polyoxyalkylene compound is 2 mass% or more with respect to the total solid content in the said easily bonding layer, The laminated film characterized by the above-mentioned.   The laminated film according to claim 1, wherein the water-soluble polyoxyalkylene compound is at least one selected from polyethylene glycol, polypropylene glycol, and a copolymer of polyethylene glycol and polypropylene glycol.   The content rate of the said water-soluble polyoxyalkylene compound is 2-30 mass% with respect to the total amount of solids in an easily bonding layer, The laminated film of Claim 1 or 2 characterized by the above-mentioned. The water contact angle of the surface of the easy-adhesion layer when stored for 240 hours under the conditions of 65 ° C. and relative humidity 95% is R _1, and the water contact angle of the surface of the easy-adhesion layer before the storage treatment is performed If the set to R _2, R ₂ -R ₁ is laminated film according to any one of claims 1 to 3, characterized in that 5 ° or less.   The said easily bonding layer contains at least 1 sort (s) chosen from a polyester resin, a polyurethane resin, and an acrylic resin, The laminated | multilayer film of any one of Claims 1-4 characterized by the above-mentioned.   An optical laminated film, wherein an optical functional layer is laminated so as to face the easily adhesive layer of the laminated film according to any one of claims 1 to 5.   The optical laminated film according to claim 6, wherein the optical functional layer is a prism layer.   The optical laminated film according to claim 6 or 7, wherein the optical functional layer is a UV curable resin and has an elastic modulus of 5 to 200 MPa.   The display apparatus which mounts the optical laminated | multilayer film of any one of Claims 6-8. A method for producing a laminated film, comprising: applying a coating liquid that forms an easy-adhesion layer on at least one surface of a support made of polyester;
The easy adhesion layer contains a water-soluble polyoxyalkylene compound,
The water contact angle of the surface of the easy adhesion layer is 72 ° or less,
The content rate of the said water-soluble polyoxyalkylene compound is a manufacturing method of the laminated | multilayer film which is 2 mass% or more with respect to the total amount of solids in the said easily bonding layer.   After apply | coating the coating liquid which forms an optical function layer on the surface of the easily bonding layer of the laminated | multilayer film of any one of Claims 1-5, an active energy ray is irradiated and hardened. A method for producing an optical laminated film.

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