JP6624054B2 - Laminated film and method for producing the same - Google Patents

Description

  The present invention relates to a laminated film in which a resin layer is provided on at least one side of a polyester film and a method for producing the same.

  Thermoplastic resin films, especially biaxially stretched polyester films, have excellent properties such as mechanical properties, electrical properties, dimensional stability, transparency, and chemical resistance. Widely used in applications.

  In recent years, polyester films have been used in various optical films, particularly for display members such as touch panels, liquid crystal display panels (LCD), plasma display panels (PDP), and organic electroluminescence (organic EL).

  In particular, in such applications, a hard coat film in which a hard coat layer is laminated on a polyester film is used. In this hard coat film, in order to improve the adhesion between the polyester film as the base material and the hard coat layer, a coating layer having easy adhesion is often provided as an intermediate layer between them. Further, since the polyester film is easily charged, dust easily adheres in the process of processing the hard coat layer, and the adhesion of the dust often causes foreign matter defects or lowers the yield. For this reason, a film serving as a base material of the hard coat film is required to have antistatic properties.

  Further, the hard coat film is required to have adhesiveness to a substrate under normal temperature, high temperature and high humidity, transparency, scratch resistance, antifouling property and the like. Further, since it is often used on the surface of a display or the like, the hard coat film is required to have visibility and design. When the hard coat layer is laminated on the base material polyester film, if the refractive index of the hard coat layer and the base material polyester film are different, interference spots are generated due to interfacial reflection and visibility deteriorates. In addition, reduction of interference spots is required.

  In particular, in recent years, the demands for suppression of interference spots under a fluorescent lamp, transparency, and adhesion between layers have been increasing particularly as the screen size, the definition, and the quality have been further increased.

  On the other hand, when a refractive index adjusting layer composed of a high refractive index layer / a low refractive index layer is laminated on the surface of the hard coat layer, by increasing the refractive index of the hard coat layer, the refractive index of the high refractive index layer is reduced. The rate layer can be omitted. As a result, in the film manufacturing process, the process can be omitted without impairing the function, and the yield can be improved and the cost can be significantly reduced. This technology has attracted attention due to recent strong cost reduction demands.

  When such a hard coat layer having a high refractive index (for example, a refractive index of 1.63) is provided on a polyester film of a base material (for example, a refractive index of 1.65), as a method of suppressing interference spots, (a) A method is disclosed in which a base film is calendered after an easy-adhesion layer is formed to reduce local thickness variation of the base film (Patent Document 1).

  Also disclosed is (b) a method of providing a layer having a low refractive index on the surface layer of a base film, providing a hard coat layer and an easy-adhesion layer having an intermediate refractive index between the base film, and utilizing the cancellation of interference. (Patent Document 2).

  Furthermore, (c) a method of providing a high-refractive-index easy-to-adhesive layer having an intermediate refractive index (1.63 to 1.66) between the hard coat layer and the base film is disclosed ( Patent Document 3).

  As a method for imparting antistatic properties to a polyester film, a method of applying antistatic to a polyester resin and applying the same (for example, see Patent Document 4) and a method of applying a styrene sulfonic acid copolymer (for example, see Patent Document 5) )It has been known. These methods are antistatic methods using an ion conductive type antistatic agent.

  Also, a method of providing a polyaniline-based conductive layer on the surface of a polyester film by coating or the like (for example, see Patent Document 6) is known. This method is an antistatic method using an electron conductive type antistatic agent.

  Also, a method of providing a layer of a tin oxide-based conductive agent doped with antimony on the surface of a polyester film by coating or the like (Patent Document 7) is known. This method is an antistatic method using an electron conductive type antistatic agent.

  Further, as an antistatic method using another electron conductive type compound, an antistatic property imparted by a polythiophene-based conductive agent has been proposed. For example, an antistatic method in which a coating liquid containing a polythiophene-based conductive agent and a latex polymer is applied (Patent Document 8) is known. Further, it has been proposed to use an epoxy crosslinking agent in combination with a polythiophene-based conductive agent, and to impart an antistatic property to achieve both transparency and antistatic property of a coating film (Patent Document 9).

JP 2001-71439 A Japanese Patent No. 4169548 Japanese Patent No. 3632044 JP-A-60-141525 JP-A-61-204240 JP-A-7-101016 JP-A-11-278858 JP-A-6-295016 Japanese Patent No. 3966171

  In the method of Patent Document 1, although the unevenness of interference can be relatively suppressed when the refractive index of the hard coat layer is 1.60 or less, the hard coat layer having a refractive index of 1.60 or more and 1.65 or less is laminated. Had good adhesion, but noticeable interference spots. Further, the method of Patent Document 2 is only applicable when the material of the base film is polyethylene naphthalenedicarboxylate (refractive index: 1.7 or more) and lacks versatility.

  Patent Document 3 proposes a method of adding a water-soluble metal chelate compound or a metal acylate compound to a water-soluble polyester resin. However, water-soluble metal chelate compounds and metal acylate compounds often have high acidity, and when other components are contained in the resin layer, agglomeration occurs, thereby lowering transparency or deteriorating interference spot suppression. There was a problem to do.

  Further, in the methods using the ionic conductive type antistatic agent described in Patent Documents 4 and 5, since the antistatic property depends on humidity, there is a problem that the antistatic agent is charged depending on the humidity. In the methods of Patent Documents 6 to 9, although antistatic properties can be exhibited without depending on humidity, interference spots are conspicuous when a high-refractive-index hard coat layer is laminated, and further high-refractive-index hard There was a problem that the adhesiveness with the coat layer was also reduced.

  Therefore, in the present invention, the above-mentioned disadvantages are solved, the transparency, the interference spot suppressing property, the adhesion to the base material and the high refractive index hard coat layer are excellent, and the laminate exhibits a high level of antistatic property regardless of humidity. It is an object to provide a polyester film.

In order to solve the above problems, the laminated film of the present invention has the following configuration. That is, a laminated film in which a resin layer is provided on at least one side of a polyester film, the reflectance of the resin layer surface at a wavelength of 550 nm is 6.0% or more, and the surface resistivity of the resin layer surface is 10%. ¹² Ω / □ or less, and the surface energy change Δγ before and after the boiling test of the resin layer surface Δγ (Δγ = | surface energy of resin layer after boiling test−surface energy of resin layer before boiling test |) This is a laminated film in which a resin layer is provided on at least one side of a polyester film of 5 mN / m or less.

  The laminated film of the present invention has high transparency and high anti-reflective property regardless of humidity. Can be expressed. Furthermore, in a film in which a high refractive index hard coat layer is laminated, antistatic properties can be exhibited even on the surface of the hard coat layer.

  Hereinafter, the laminated film of the present invention will be described in detail.

The laminated film of the present invention is a laminated film in which a resin layer is provided on at least one side of a polyester film, the reflectance of the resin layer surface at a wavelength of 550 nm is 6.0% or more, and the surface of the resin layer surface The specific resistance value is 10 ¹² Ω / □ or less, and the surface energy change Δγ before and after the boiling test of the resin layer surface (Δγ = | surface energy of resin layer after boiling treatment test−resin of resin layer before boiling treatment test) The surface energy |) needs to be 5 mN / m or less.

  In the laminated film of the present invention, it is necessary that the reflectance of the resin layer at a wavelength of 550 nm is 6.0% or more. The reflectance of the resin layer surface at a wavelength of 550 nm indicates the refractive index of the resin layer. When the reflectance at a wavelength of 550 nm is higher than 6.0%, it indicates that the refractive index of the resin layer has been increased to a region close to the PET film, and when a high refractive index hard coat layer is laminated. It can have interference spot suppression properties. More preferably, it is not less than 6.0% and not more than 6.5%. As a method for making the reflectance of the resin layer surface at a wavelength of 550 nm at 6.0% or more, there are a method of including a metal oxide particle (A) described later in the resin layer and a method of including a metal chelate compound. Among them, the method using the metal oxide particles (A) having a number average particle diameter of 3 nm or more and 50 nm or less is preferable from the viewpoint of excellent transparency and adhesiveness during wet heat treatment. In the method in which the metal chelate compound is contained, the decomposition of the chelate bond by the wet heat treatment progresses, and there is a possibility that the appearance may deteriorate over time and the adhesiveness after the wet heat treatment may occur.

The laminated film of the present invention is required to have a surface resistivity value of the resin layer surface of 10 ¹² Ω / □ or less. The surface specific resistance value of the resin layer surface is an index indicating the antistatic property of the resin layer surface. When the surface specific resistance of the resin layer surface is high, electricity hardly flows to the resin layer surface (easy to be charged), and when the surface specific resistance is low, electricity easily flows (hard to be charged). By setting the surface specific resistance of the resin layer surface to 10 ¹² Ω / □ or less, a high level of antistatic property can be exhibited, and as a result, dust adhesion during processing can be prevented. The surface specific resistance of the surface of the resin layer is more preferably 10 ¹¹ Ω / □ or less.
Furthermore, in the present invention, by setting the surface specific resistance value of the resin layer surface of the laminated film to 10 ¹¹ Ω / □ or less, the laminated hard coat is formed on the laminated film of the present invention in which the high refractive index hard coat layer is laminated. Antistatic properties can also be exhibited on the surface of the layer. The reason is presumed as follows. A general hard coat layer having a high refractive index is often made of an acrylic resin, and has a polar functional group such as a carboxyl group. Therefore, the hard coat layer can polarize a polar functional group such as a carboxylic acid, so that the hard coat layer is not a perfect insulator but has a large resistance but a current conductor. When the surface resistivity of the laminated film is 10 ¹¹ Ω / □ or less, even if charge is generated on the surface of the high-refractive-index hard coat layer (charge is accumulated), the electric charge remains inside the high-refractive-index hard coat layer. , And further to the resin layer of the laminated film thereunder, so that the electric charge can be efficiently made to flow. As a result, it is presumed that in a film obtained by laminating a high refractive index hard coat layer on a laminated film, the surface specific resistance of the high refractive index hard coat layer can be reduced (it is difficult to be charged).

Further, as a more interesting phenomenon, in the film in which the hard coat layer is laminated on the resin layer surface of the laminated film of the present invention, the charge amount when the roll that winds up the film in which the hard coat layer is laminated is unwound is suppressed. It has been found that this has the effect. This phenomenon is caused not only by the so-called antistatic region where the surface specific resistance value of the hard coat layer surface is 10 ¹² Ω / □ or less, but also by the hard insulating layer where the surface specific resistance value exceeds 10 ¹³ Ω / □. It has also been confirmed on the surface of the coat layer. It is presumed that the reason for this is that there is a small amount of charge flow that does not appear in the surface resistivity value. Therefore, in the film in which the hard coat layer is laminated on the surface of the resin layer of the laminated film of the present invention, the amount of charge on the surface of the hard coat layer is suppressed, so that dust adhesion during film processing can be prevented.

As a method for lowering the surface specific resistance value of the resin layer surface, there is a method in which a conductive polymer or an ionic conductive resin is contained in the resin layer. Examples of the method for reducing the surface resistivity of the resin layer surface to 10 ¹² Ω / □ or less include a method in which the resin layer contains a π-electron conjugated polymer compound (B) such as polythiophene or polyaniline, an ammonium salt, a sulfone. There is a method of including an ion conductive compound such as an acid salt. Among them, since the surface specific resistance value of the resin layer surface can be 10 ¹² Ω / □ or less even if the content is small, the use of the π-electron conjugated polymer compound (B) makes it possible to obtain an antistatic property. It is preferable from the viewpoint of achieving both low interference and adhesiveness. The lower limit of the surface resistivity of the resin layer is not particularly limited, but if the surface resistivity is excessively reduced, the amount of the conductive polymer or the ionic conductive resin contained in the resin layer is reduced. It is preferable that the resistivity is 10 ⁵ Ω / □ or more because the film-forming property and the transparency may decrease.

  The surface energy change Δγ before and after the boiling test of the resin layer surface is obtained by a method described later, and represents a change in the structure of the resin layer due to the boiling test. A large surface energy change Δγ before and after the boiling test indicates a large change in the structure of the resin layer due to the boiling test, and a small surface energy change Δγ before and after the boiling test indicates a small change in the structure of the resin layer due to the boiling test. It represents that. By setting the surface energy change Δγ before and after the boiling test to 5 mN / m or less, in addition to transparency, it is possible to maintain excellent adhesion and antistatic properties with the high refractive index hard coat layer after the boiling treatment. . The amount of change in surface energy Δγ before and after the boiling test is more preferably 3 mN / m or less. The amount of change in surface energy Δγ before and after the boiling test can be made 5 mN / m or less by reducing the change in the chemical bond of the resin layer even when immersed in boiling water. In order to reduce the surface energy change Δγ before and after the boiling test to 5 mN / m or less, there are a method of making the resin constituting the resin layer highly crosslinked, a method of increasing the Tg of the resin constituting the resin layer, and a method of making the resin constituting the resin layer hydrophobic. No. Among them, the method of including the epoxy compound (C) and the acrylic resin (D) in the resin layer is such that a dense cross-link is built in the resin layer, and the energy change Δγ before and after the boiling test is 5 mN / m or less. It is preferable because it can exhibit a reflectance and an antistatic property.

  Further, in the laminated film of the present invention, the resin layer includes a metal oxide particle (A) having a number average particle diameter of 3 nm or more and 50 nm or less, a π-electron conjugated polymer compound (B), and an epoxy compound (C). When the acrylic resin (D) is contained, transparency, excellent suppression of interference spots when a high refractive index hard coat layer is laminated, excellent adhesion to the high refractive index hard coat layer, and a high level of antistatic regardless of humidity This is preferable since the property can be expressed.

  Further, in the laminated film of the present invention, the arithmetic average roughness (Ra) of the surface of the resin layer is preferably 20 nm or less. By setting the arithmetic average roughness (Ra) of the resin layer surface to 20 nm or less, it is possible to suppress coating film shaving during processing, and to have excellent transparency, antistatic property, and interference spot suppression property after processing. Things. The arithmetic average roughness (Ra) of the resin layer surface can be reduced by reducing the number average particle diameter of the particles contained in the resin layer. However, if the particle diameter is too small, the particles tend to aggregate because the Van der Waals force between the particles increases, and the arithmetic average roughness (Ra) may increase due to the generation of coarse particles due to the aggregation. Therefore, the particles contained in the resin layer preferably have a number average particle diameter of 3 nm or more and 50 nm or less. When the metal oxide particles (A) are used as the particles contained in the resin layer, when the resin layer contains the epoxy compound (C) in addition to the metal oxide particles (A), the arithmetic average of the surface of the resin layer is obtained. The roughness (Ra) can be reduced. When the epoxy compound (C) is contained together with the metal oxide particles (A), the arithmetic average roughness of the surface of the resin layer is reduced. The epoxy compound (C) can improve the fluidity of the resin layer. Therefore, as a result, it is considered that there is an effect of suppressing aggregation of the metal oxide particles (A).

[Metal oxide particles (A)]
In the laminated film of the present invention, the resin layer preferably contains metal oxide particles (A) having a number average particle diameter of 3 nm or more and 50 nm or less. By using such metal oxide particles (A), the reflectance of the resin layer surface at a wavelength of 550 nm can be increased. As a result, it is possible to suppress interference spots when a high refractive index hard coat layer is laminated on the resin layer of the laminated film of the present invention. Further, since the number average particle diameter of the metal oxide particles (A) is sufficiently smaller than the wavelength of visible light, the transparency of the laminated film can be increased.

  The metal oxide particles (A) in the present invention are rich in ductility and ductility, are good conductors of electricity and heat, and are elements having a metallic luster, that is, boron (B), silicon (Si), arsenic ( As) refers to oxide fine particles of an element located to the left of a diagonal line connecting As), tellurium (Te), and astatine (At). Further, the fine particles are preferably oxide fine particles of an element located on the right side of the alkaline earth metals (Group 2) in the periodic table.

  As such a metal oxide fine particle, a metal oxide particle having a high refractive index, preferably a metal oxide particle having a refractive index of 1.6 or more is preferable from the viewpoint of suppressing interference spots. The high refractive index metal oxide particles include TiO.₂, ZrO₂, ZnO, CeO₂, SnO₂, Sb₂O₅, Indium-doped tin oxide (ITO), phosphorus-doped tin oxide (PTO), Y₂O ₅, La₂O₃, Al₂O₃, And the like.

One type of these metal oxide particles may be used alone, or two or more types may be used in combination. From the viewpoints of dispersion stability and refractive index, titanium oxide particles (TiO ₂ ) (A ₁ ′) and / or zirconium oxide particles (ZrO ₂ ) (A ₂ ′) are particularly preferable.

  Here, the number average particle diameter of the metal oxide particles (A) will be described. Here, the number average particle diameter refers to a particle diameter determined by a transmission electron microscope (TEM). The magnification is 500,000, and the outer diameter of 10 particles present on the screen is the number average particle diameter obtained by measuring a total of 100 particles in 10 visual fields. Here, the outer diameter refers to the maximum diameter of the particle (that is, the longest diameter of the particle and indicates the longest diameter in the particle). Similarly, in the case of a particle having a cavity inside, the maximum diameter of the particle is also referred to as the outer diameter. Represent.

  When the number average particle diameter of the metal oxide particles (A) is small, the Van der Waals force between the metal oxide particles becomes extremely large, so that the metal oxide particles are easily aggregated, and light is scattered, so that transparency is reduced. is there. On the other hand, when the number average particle diameter of the metal oxide particles (A) is large, the metal oxide particles (A) become a starting point of light scattering, and haze may increase or reflectance may decrease. Therefore, the metal oxide particles (A) preferably have a number average particle diameter of 3 nm or more and 50 nm or less from the viewpoint of transparency. It is preferably from 10 nm to 45 nm, more preferably from 15 nm to 40 nm.

  In the present invention, the content of the metal oxide particles (A) in the resin layer is preferably 30% by weight or more and 90% by weight or less based on the entire resin layer. By setting the content in this range, the reflectance of the resin layer surface at a wavelength of 550 nm can be 6.0% or more, and the suppression of interference spots when a hard coat layer is laminated is excellent. The content of the metal oxide particles (A) in the resin layer is preferably 30% by weight or more and 80% by weight or less, more preferably 30% by weight or more and 70% by weight or less. In addition, in this invention, the content in a resin layer represents the content in the solid content ([(weight of resin composition)-(weight of solvent)]) of the resin composition which forms a resin layer.

  In the present invention, the metal oxide particles (A) are more preferably particles (AD) having an acrylic resin (D) described later on part or all of the surface of the metal oxide particles (A). (The resin layer containing the particles (AD) naturally contains the metal oxide particles (A) and the acrylic resin (D)). The fat layer contains such particles (AD), and when forming a resin layer using the resin composition described below, further aggregation of the metal oxide particles (A) and particles (AD) in the drying process. As a result, the surface roughness of the resin layer surface can be reduced to 20 nm or less. Further, it is possible to improve the transparency of the polyester film on which the resin layer is laminated.

  Here, in the present invention, the phrase “the metal oxide particles (A) have the acrylic resin (D) on the surface thereof” means that the acrylic resin (D) is partially or entirely provided on the surface of the metal oxide particles (A). ) Means that it is adsorbed and adhered.

  The method for producing the particles (AD) is not particularly limited, and examples thereof include a method of subjecting the metal oxide particles (A) to a surface treatment with an acrylic resin (D). The methods i) to (iv) are exemplified. In the present invention, the surface treatment refers to a treatment for adsorbing and attaching the acrylic resin (D) to all or a part of the surface of the metal oxide particles (A).

  (I) A method in which a mixture obtained by previously mixing the metal oxide particles (A) and the acrylic resin (D) is added to a solvent and then dispersed.

  (Ii) A method in which the metal oxide particles (A) and the acrylic resin (D) are sequentially added and dispersed in a solvent.

  (Iii) A method in which the metal oxide particles (A) and the acrylic resin (D) are dispersed in a solvent in advance, and the obtained dispersion is mixed.

  (Iv) A method of dispersing the metal oxide particles (A) in a solvent and then adding an acrylic resin (D) to the obtained dispersion.

  In addition, as a device for performing dispersion, a dissolver, a high-speed mixer, a homomixer, a meader, a ball mill, a roll mill, a sand mill, a paint shaker, an SC mill, an annular mill, a pin mill, and the like can be used.

  As a dispersing method, a method of rotating the rotating shaft at a peripheral speed of 5 to 15 m / s for 5 to 10 hours using the above-mentioned device is exemplified.

  Further, at the time of dispersion, it is more preferable to use dispersed beads such as glass beads from the viewpoint of enhancing dispersibility. The bead diameter is preferably 0.05 to 0.5 mm, more preferably 0.08 to 0.5 mm, and particularly preferably 0.08 to 0.2 mm.

  The method of mixing and stirring can be performed by shaking the container by hand, using a magnetic stirrer or a stirring blade, irradiating ultrasonic waves, or dispersing vibration.

  The presence / absence of adsorption / adhesion of the acrylic resin (D) to all or a part of the surface of the metal oxide particles (A) can be confirmed by the following analysis method. An object to be measured (for example, a resin composition containing metal oxide particles (A)) is centrifuged by a Hitachi tabletop ultracentrifuge (CS150NX manufactured by Hitachi Koki Co., Ltd.) (rotational speed: 3000 rpm, separation time) 30 minutes), after sedimentation of the metal oxide particles (A) (and the acrylic resin (D) adsorbed on the surface of the metal oxide particles (A)), the supernatant is removed, and the sediment is concentrated to dryness. . The concentrated and dried precipitate is analyzed by X-ray photoelectron spectroscopy (XPS) to confirm the presence or absence of the acrylic resin (D) on the surface of the metal oxide particles (A). When it is confirmed that 1% by weight or more of the acrylic resin (D) is present on the surface of the metal oxide particles (A) with respect to the total of 100% by weight of the metal oxide particles (A), It is assumed that the acrylic resin (D) is adsorbed and adhered to the surface of (A).

The presence or absence of the particles (AD) in the resin layer of the laminated film is determined by using XPS while etching from the resin layer side of the laminated film with an argon ion at an etching rate of 1 nm / min (in terms of SiO ₂ ). You can check. That is, when the presence of the acrylic resin (D) on the surface of the metal oxide particles (A) is confirmed, it is understood that the metal oxide particles (A) are particles (AD).

  The acrylic resin (D) comprises a monomer unit (d1) represented by the formula (1), a monomer unit (d2) represented by the formula (2), and a monomer unit (d3) represented by the formula (3). The acrylic resin (D) is preferred.

(In the formula (1), the R ₁ group represents a hydrogen atom or a methyl group, and n represents an integer of 9 or more and 34 or less.)

(In the formula (2), the group R ₂ represents a hydrogen atom or a methyl group. The group R ₄ represents a group containing two or more saturated carbon rings.)

(In the formula (3), the R ₃ group represents a hydrogen atom or a methyl group. The R ₅ group is a hydroxyl group, a carboxyl group, a tertiary amino group, a quaternary ammonium base, a sulfonic acid group, or a phosphoric acid group. Represents a group.)
Since the acrylic resin (D) has the above-mentioned monomer unit, the amount of energy change Δγ on the surface of the resin layer before and after the boiling test can be reduced while maintaining the transparency, and the adhesion to the hard coat layer is strengthened. It is preferable because it is possible to make It is particularly preferable to use an acrylic resin (D) having a monomer unit having a carboxyl group as the R ₃ group in the formula (3) since the adhesiveness can be further improved.

  An acrylic resin (D) having a monomer unit (d1) represented by the formula (1), a monomer unit (d2) represented by the formula (2), and a monomer unit (d3) represented by the formula (3) Is preferably 3 parts by weight or more and 25 parts by weight or less based on 100 parts by weight of the metal oxide particles (A) contained in the resin layer. More preferably, it is 5 to 20 parts by weight, and still more preferably 7 to 15 parts by weight. By setting the content in the above range, the reflectance at a wavelength of 550 nm can be 6.0% or more. As a result, the transparency of the resin layer is improved, and further, the suppression of interference spots during lamination of the hard coat layer is sufficient. This is preferable since it can be expressed in

  Here, when the acrylic resin (D) in the present invention has the monomer unit (d1) represented by the formula (1), the dispersibility of the metal oxide particles (A) in the aqueous solvent is further improved, and This is preferable since a laminated film having better properties can be obtained, and is more preferable because the interference spot suppression property (visibility) when a high refractive index hard coat layer is laminated is further improved.

  Here, in order for the acrylic resin (D) in the present invention to have the monomer unit (d1) represented by the formula (1), the (meth) acrylate monomer (d1 ′) represented by the following formula (4) ) Is used as a raw material and polymerization is more preferred.

  As the (meth) acrylate monomer (d1 ′), a (meth) acrylate monomer in which n in the formula (4) is an integer of 9 to 34 is preferable, and a (meth) acrylate of 11 to 32 is more preferable. Monomers, more preferably 13 to 30 (meth) acrylate monomers.

  The (meth) acrylate monomer (d1 ′) is not particularly limited as long as n in the formula (4) is 9 or more and 34 or less, and specifically, decyl (meth) acrylate and dodecyl (meth) A) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, 1-methyltridecyl (meth) acrylate, hexadecyl (meth) acrylate, octadecyl (meth) acrylate, eicosyl (meth) acrylate, docosyl (meth) acrylate, tetracosyl Examples thereof include (meth) acrylate and triacontyl (meth) acrylate, and particularly preferred are dodecyl (meth) acrylate and tridecyl (meth) acrylate. These may be used alone or as a mixture of two or more.

  Further, the acrylic resin (D) in the present invention is preferably a resin having a monomer unit (d2) represented by the formula (2).

  In the formula (2), when an acrylic resin having a monomer unit containing two or more saturated carbocycles is used, the acrylic resin sufficiently functions as steric hindrance, so that aggregation of the metal oxide particles (A) in the resin composition Alternatively, it is preferable because sedimentation can be suppressed, the reflectance of the resin layer at a wavelength of 550 nm can be 6.0% or more, and low interference when a hard coat layer is laminated can be improved. Further, since aggregation of the metal oxide particles (A) can be suppressed, coarse components in the resin layer can be reduced. As a result, the conductive polymer (B) can also be uniformly present in the resin layer, the surface resistivity of the resin layer can be less than the 12th power, and excellent antistatic properties can be exhibited. it can. In addition, since the coarse component can be reduced, the surface roughness of the resin layer can be reduced to 20 nm or less, and the processability of the laminated film is excellent.

  In order for the acrylic resin (D) in the present invention to have the monomer unit (d2) represented by the formula (2), the (meth) acrylate monomer (d2 ′) represented by the following formula (5) is used as a raw material. And polymerization is preferred.

As the (meth) acrylate monomer (d2 ′) represented by the formula (5), as R ₄ , a cross-linked condensed cyclic compound (a structure in which two or more rings each share two atoms and are bonded to each other) ), Spirocyclic (having a structure in which two cyclic structures are bonded by sharing one carbon atom), specifically, compounds having a bicyclo, tricyclo, tetracyclo group, or the like In particular, a (meth) acrylate containing a bicyclo group is preferable from the viewpoint of compatibility with the binder.

  Examples of the (meth) acrylate containing a bicyclo group include isobornyl (meth) acrylate, bornyl (meth) acrylate, disiloclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, adamantyl (meth) acrylate, and dimethyladamantyl. (Meth) acrylate and the like can be mentioned, and isobonyl (meth) acrylate is particularly preferable.

  Further, the acrylic resin (D) in the present invention is preferably a resin having a monomer unit (d3) represented by the formula (3).

When an acrylic resin having a monomer unit having a hydroxyl group, a carboxyl group, a tertiary amino group, a quaternary ammonium group, a sulfonic acid group, and a phosphoric acid group as the R ₅ group in the formula (3) is used, metal oxide particles ( Since A) can be uniformly dispersed in the resin layer, aggregation or sedimentation of the metal oxide particles (A) in the resin composition can be suppressed, so that the reflectance of the resin layer at a wavelength of 550 nm is 6%. 0.0% or more. As a result, it is preferable because the low coherence when the hard coat layer is laminated can be improved.

  In order for the acrylic resin (D) in the present invention to have the monomer unit (d3) represented by the formula (3), the (meth) acrylate monomer (d3 ′) represented by the following formula (6) is used as a raw material. And need to be polymerized.

  The following compounds are exemplified as the (meth) acrylate monomer (d3 ') represented by the formula (6).

  Examples of the (meth) acrylate monomer having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2,3-dihydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and polyethylene. Monoesters of polyhydric alcohols such as glycol mono (meth) acrylate and (meth) acrylic acid, and compounds obtained by ring-opening polymerization of ε-caprolactone with the monoesters, and particularly, 2-hydroxyethyl ( (Meth) acrylate and 2-hydroxypropyl (meth) acrylate are preferred.

  Examples of the (meth) acrylate monomer having a carboxyl group include α, β-unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, fumaric acid, and maleic acid, or hydroxyalkyl (meth) acrylate and acid anhydride. And the like, and particularly preferred are acrylic acid and methacrylic acid.

  Examples of the tertiary amino group-containing monomer include N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, and N, N-dimethylaminopropyl (meth) acrylate. N, N-dialkylamino such as dialkylaminoalkyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylamide, N, N-diethylaminoethyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide Examples thereof include alkyl (meth) acrylamide, and N, N-dimethylaminoethyl (meth) acrylate is particularly preferable.

  The quaternary ammonium base-containing monomer is preferably a monomer obtained by allowing a quaternizing agent such as epihalohydrin, benzyl halide, or alkyl halide to act on the tertiary amino group-containing monomer, and specifically, 2- (methacryloyloxy). ) Ethyltrimethylammonium chloride, 2- (methacryloyloxy) ethyltrimethylammonium bromide, (meth) acryloyloxyalkyltrialkylammonium salts such as 2- (methacryloyloxy) ethyltrimethylammonium dimethylphosphate, methacryloylaminopropyltrimethylammonium chloride, methacryloyl (Meth) acryloylaminoalkyltrialkylammonium salts such as aminopropyltrimethylammonium bromide, tetrabutylamine Tetra (meth) acrylates such as bromide (meth) acrylate, and tri-alkyl benzyl ammonium (meth 9 acrylates such as trimethylbenzylammonium (meth) acrylate. In particular 2- (methacryloyloxy) ethyl trimethyl ammonium chloride are preferred.

  Examples of the sulfonic acid group-containing monomer include (meth) acrylamide-alkanesulfonic acid such as butylacrylamidesulfonic acid and 2-acrylamido-2-methylpropanesulfonic acid, and sulfoalkyl (meth) such as 2-sulfoethyl (meth) acrylate. Acrylates and the like are mentioned, and 2-sulfoethyl (meth) acrylate is particularly preferable.

  Examples of the phosphoric acid group-containing acrylic monomer include acid phosphooxyethyl (meth) acrylate, and particularly preferred is acid phosphooxyethyl (meth) acrylate.

  In particular, in the present invention, by using a (meth) acrylate monomer having a carboxyl group as the (meth) acrylate monomer (d3 ′) represented by the formula (6), the energy change of the resin layer surface before and after the boiling test is performed. The amount Δγ can be reduced. As a result, the adhesiveness between the resin layer and the hard coat layer can be made stronger, which is preferable. It is presumed that the reason is that the carboxyl group reacts with the epoxy compound to form a stronger resin layer.

[Π electron conjugated polymer compound]
In the present invention, the resin layer preferably contains a π-electron conjugated polymer compound (B). In the present invention, the π-electron conjugated system means that π electrons are delocalized by alternate single bonds and multiple bonds, or by atoms having single or multiple bonds and available p-orbitals such as oxygen and nitrogen. To indicate that In the present invention, the high molecular compound refers to a compound having a number average molecular weight of 3000 or more. It is preferable that the π-electron conjugated polymer compound (B) has conductivity (the surface specific resistance is 10 × 10 or less). As the π-electron conjugated polymer compound used in the present invention, the repeating unit is aniline and / or a derivative thereof, pyrrole and / or a derivative thereof, isothianaphthene and / or a derivative thereof, acetylene and / or a derivative thereof, It is preferable to use thiophene and / or a derivative thereof. Among them, a π-electron conjugated polymer compound in which the repeating unit is thiophene and / or a derivative thereof is particularly preferable, since coloring is less and high total light transmittance is obtained.

  Examples of the π-electron conjugated polymer compound in which the repeating unit is thiophene and / or a derivative thereof include a compound having a structure in which the 3- and 4-positions of the thiophene ring are substituted. Those in which an oxygen atom is bonded to the carbon atoms at the 3- and 4-positions are preferred. Some of those in which a hydrogen atom or a carbon atom is directly bonded to a carbon atom have insufficient water solubility.

  Further, as a preferred embodiment of the π-electron conjugated polymer compound in which the repeating unit is thiophene and / or a derivative thereof, a compound in which thiophene and / or a derivative thereof is polymerized in the presence of a polyanion is given. Examples of the polyanion include polyacrylic acid, polymethacrylic acid, polymaleic acid, polystyrenesulfonic acid, and the like, and polystyrenesulfonic acid is preferred from the viewpoint of conductivity.

  By polymerizing the thiophene and / or its derivative in the presence of a polyanion, a repeating structure represented by the following formula (7) and / or

The repeating structure represented by the following formula (8)

Can be obtained. In the repeating structure represented by the formula (7), R ₆ and R ₇ each independently represent a hydrogen atom, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group, or an aromatic hydrocarbon. Represents a group, for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a cyclohexylene group, a benzene group and the like. P is an integer of 2 or more. In the repeating structure represented by the formula (8), m is an integer of 1 to 4, and q is an integer of 2 or more.

  In the present invention, as the π-electron conjugated polymer compound (B), it is preferable to use a polythiophene having a repeating structural formula represented by the formula (8) and / or a polythiophene derivative. In the structure, m = 1 (methylene group), m = 2 (ethylene group), and m = 3 (trimethylene group) are preferable. Among them, particularly preferred is an ethylene group compound having m = 2, that is, poly-3,4-ethylenedioxythiophene.

  The compound can be produced by the methods disclosed in, for example, JP-A-2000-6324, EP-A-602713, and US Pat. No. 5,391,472, but other methods may also be used.

  For example, starting from an alkali metal salt of 3,4-dihydroxythiophene-2,5, -dicarboxyester as a starting material, 3,4-ethylenedioxythiophene is obtained, and then potassium peroxodisulfate and sulfuric acid are added to an aqueous polystyrenesulfonic acid solution. By introducing iron and the previously obtained 3,4-ethylenedioxythiophene and reacting with each other, an acidic polymer such as polystyrenesulfonic acid is added to polythiophene such as poly (3,4-ethylenedioxythiophene). A composite composition can be obtained.

  As an aqueous coating composition containing poly-3,4-ethylenedioxythiophene and polystyrenesulfonic acid, H.I. C. For example, those sold as “Baytron” P by Starck (Germany) can be used.

  In the present invention, the content of the π-electron conjugated polymer (B) contained in the resin layer is preferably in the range of 3 to 25 parts by weight, more preferably 100 parts by weight of the metal oxide particles (A). A range of 5 to 20 parts by weight is more preferred. By setting the content within the above range, both the interference fringe suppressing property and the antistatic property can be achieved.

[Epoxy compound (C)]
In the laminated film of the present invention, the resin layer preferably contains an epoxy compound (C). In the laminated film of the present invention, when the resin layer contains the epoxy compound (C), the fluidity of the resin layer during curing is improved, and as a result, aggregation of the metal oxide particles (A) can be suppressed. And the transparency of the laminated film can be imparted. Further, by suppressing the aggregation of the metal oxide particles (A), the surface roughness of the resin layer can be reduced, so that the coating film can be prevented from being scraped during processing. For example, scratches during processing of the hard coat layer can be suppressed, and processing defects when vapor deposition, sputtering, and the like are further performed on the hard coat layer can be suppressed. In the present invention, the expression that the resin layer contains the epoxy compound (C) means that the resin layer contains an epoxy compound or an epoxy compound derivative (such as a compound in which the epoxy compound is ring-opened).

  When the epoxy compound (C) and the acrylic resin (D) are contained in the resin layer of the laminated film of the present invention, a crosslinking reaction between the epoxy compound (C) and the carboxylic acid group contained in the acrylic resin (D) is caused. It is possible to improve the adhesion of the resin layer to the laminate.

  The epoxy compound (C) used in the present invention more preferably has a molecular weight of 1,000 or less. When the molecular weight of the epoxy compound (C) is 1,000 or less, the effect of improving the fluidity of the resin composition described above can be made more remarkable.

  On the other hand, for example, when the molecular weight is too large (the molecular weight exceeds 1000), phenomena such as cracking of the coating film at the time of stretching after coating and drying occur, and the effect of improving transparency may not be sufficiently obtained. There is.

  In the present invention, the epoxy compound (C) is preferably a water-soluble compound. Here, the water-soluble compound means a compound having a water solubility of 80% or more. The term "water solubility" refers to a ratio of a compound dissolved when 90 parts by weight of water is dissolved in a solid content of 10 parts by weight at 23 ° C. That is, a water solubility of 80% means that at 23 ° C., 80% by weight of 10 parts by weight of a compound are dissolved in 90 parts by weight of water, and the remaining 20% by weight of a compound is left as an undissolved substance. Is shown. A water solubility of 100% means that 10 parts by weight of the compound is completely dissolved in 90 parts by weight of water at 23 ° C. In the present invention, the epoxy compound (C) preferably has a water solubility of 90% or more, more preferably 100%. When the water solubility is high, not only the coating liquid itself can be made water-soluble, but also excellent in transparency, antistatic property and interference spot suppressing property can be obtained.

  In addition, as a method of improving the fluidity of the resin layer at the time of curing, in addition to adding and including the epoxy compound (C) to the resin layer, for example, adding and including a high boiling point solvent such as glycerin or the like may be employed. Is mentioned. The method of adding and containing the epoxy compound (C) in the resin layer is preferable because it does not cause blocking, does not cause contamination inside the tenter for heat treatment, and does not cause air pollution, as compared with the method of adding and containing a high boiling point solvent. is there.

  In the laminated film of the present invention, the type of the epoxy compound (C) is not particularly limited, and examples thereof include sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, diglycerol polyglycidyl ether, and polyethylene glycol diglycidyl ether. Can be used. For example, epoxy compound "Denacol" manufactured by Nagase Chemtech Co., Ltd. (EX-611, EX-614B, EX-512, EX-521, EX-421, EX-313, EX-810, EX-830, EX-850, etc. ), Diepoxy / polyepoxy compounds (SR-EG, SR-8EG, SR-GLG, etc.) manufactured by Sakamoto Pharmaceutical Co., Ltd., epoxy compound "EPICLON" EM-85-75W, manufactured by Dainippon Ink Industries, Ltd. or CR- 5 L or the like can be suitably used, and among them, those having water solubility are preferable.

  The epoxy compound (C) preferably has an epoxy equivalent (weight per epoxy equivalent: WPE) of 100 to 300 WPE in terms of reactivity, and the epoxy equivalent is more preferably 110 to 200 WPE.

  Here, the content of the epoxy compound (C) is preferably from 20 to 60 parts by weight, more preferably from 30 to 60% by weight, based on 100 parts by weight of the metal oxide particles (A). It is.

  By setting the epoxy compound (C) to 20% by weight or more and 60% by weight or less based on 100 parts by weight of the metal oxide particles (A), the dispersibility of the metal oxide particles (A) is improved and the transparency is improved. And the interference spot suppression property, antistatic property and interference spot suppression property are improved.

[Ionic conductive compound (E)]
In the laminated film of the present invention, from the viewpoint of improving the antistatic property, the resin layer may contain an ion conductive compound (E) instead of the π-electron conjugated polymer compound (B). In the present invention, the ionic conductive resin refers to a resin having a property of conducting ions in a resin composition, and specifically, a resin having a structure such as a polystyrenesulfonic acid metal salt or an ammonium metal salt. When the ionic conductive compound (E) is contained in the resin layer, charges can be transferred by ionic conduction, and excellent antistatic properties can be exhibited.

  When producing the laminated film of the present invention, a method of applying a resin composition containing an aqueous solvent to a polyester film before completion of crystal orientation, stretching, and a method of completing crystal orientation by heat treatment are preferably used. . This is because heat treatment can be performed at a high temperature, the adhesion between the base material and the resin layer can be improved, and a more uniform and thin resin layer can be provided. When a resin layer is formed by this method, an aqueous resin composition that can be dissolved, emulsified, or suspended in an aqueous solvent is preferable in terms of environmental pollution and explosion-proof properties. Such a resin composition which can be dissolved, emulsified or suspended in water is used for copolymerization or reactivity with a monomer having a hydrophilic group (such as acrylic acid, methacrylic acid, acrylamide, vinyl sulfonic acid and a salt thereof). It can be produced by a method such as emulsion polymerization using an emulsifier or a surfactant, suspension polymerization, or soap-free polymerization.

  The polymerization initiator is not particularly limited, but a general radical polymerization initiator, for example, a water-soluble peroxide such as potassium persulfate, ammonium persulfate, or hydrogen peroxide, or benzoyl peroxide or t-butyl hydroperoxide An oil-soluble peroxide such as an oxide, or an azo compound such as azodiisobutyronitrile can be used.

[Polyester film]
The polyester film used as the base film in the laminated film of the present invention will be described. First, polyester is a generic term for polymers having an ester bond in the main chain, and includes ethylene terephthalate, propylene terephthalate, ethylene-2,6-naphthalate, butylene terephthalate, propylene-2,6-naphthalate, ethylene-α, β -Bis (2-chlorophenoxy) ethane-4,4'-dicarboxylate and at least one component selected therefrom can be preferably used.

  The polyester film using the polyester is preferably biaxially oriented. A biaxially oriented polyester film is generally stretched about 2.5 to 5 times in a longitudinal direction and a width direction orthogonal to the longitudinal direction, respectively, of an unstretched polyester sheet or film, and then subjected to heat treatment, This means that the orientation has been completed and shows a biaxial orientation pattern in wide-angle X-ray diffraction. When the polyester film is biaxially oriented, thermal stability, particularly dimensional stability and mechanical strength are sufficient, and flatness is also good.

  Also, in the polyester film, various additives, for example, antioxidants, heat stabilizers, weather stabilizers, ultraviolet absorbers, organic lubricants, pigments, dyes, organic or inorganic fine particles, fillers, antistatic An agent, a nucleating agent and the like may be added to such an extent that the characteristics are not deteriorated.

  The thickness of the polyester film is not particularly limited and is appropriately selected depending on the application and type.However, from the viewpoint of mechanical strength and handling properties, it is usually preferably 10 to 500 μm, more preferably 15 to 250 μm. , Most preferably from 20 to 100 μm. Further, the polyester film may be a composite film obtained by co-extrusion or a film obtained by laminating the obtained films by various methods.

[Method of forming resin layer]
Examples will be shown below for the method for producing the resin layer of the laminated film of the present invention, but the materials, usage amounts, ratios, processing details, processing procedures, and the like shown below may be appropriately changed without departing from the spirit of the present invention. it can. Therefore, the scope of the present invention should not be construed as being limited by the following examples.

  When the resin layer of the present invention contains the metal oxide particles (A), the π-electron conjugated polymer (B), the epoxy compound (C), and the acrylic resin (D), the reflectance at a wavelength of 550 nm is obtained. Is high, and the amount of change in surface energy before and after the boiling test can be reduced.

  In the resin layer, each of (A) to (D) may include a plurality of types. If necessary, other compounds other than (B) to (D), for example, the above-described ion conductive compound (E), or a titanate-based coupling such as a carbodiimide compound, an oxazoline compound, an aziridine compound, or a titanium chelate. Agents, methylolated or alkylolated melamine compounds, acrylamide compounds and the like.

  Further, various additives, for example, an organic lubricant, organic or inorganic fine particles, an antistatic agent and the like may be added to such an extent that the characteristics are not deteriorated.

  The resin composition using the aqueous solvent is at least an acrylic resin (D) that has been water-dispersed or solubilized, and metal oxide particles (A) are added in the order of (A) and (D), and once dispersed, metal After adsorbing the acrylic resin (D) on the surface of the oxide particles (A), the π-electron conjugated polymer (B) and the epoxy compound (C) are added, and the aqueous solvent is mixed at a desired weight ratio. Can be prepared by stirring. Then, if necessary, various additives (lubricant, inorganic particles, organic particles, surfactant, antioxidant, etc.) are mixed with the above resin composition at a desired weight ratio, and the mixture can be prepared by stirring. it can.

[Method of forming resin layer and method of manufacturing laminated film]
The method for forming the resin layer of the laminated film of the present invention will be described below with reference to examples, but the materials, usage amounts, ratios, processing details, processing procedures, and the like shown below are appropriately changed without departing from the spirit of the present invention. can do. Therefore, the scope of the present invention should not be construed as being limited by the following examples.

  The resin layer of the present invention comprises a resin film containing a metal oxide particle (A), a π-electron conjugated polymer compound (B), an epoxy compound (C), and an acrylic resin (D) on a polyester film. When the resin composition contains a solvent, the resin layer can be formed on the polyester film by drying the solvent.

  In the present invention, when a solvent is added to the resin composition, it is preferable to use an aqueous solvent as the solvent. By using an aqueous solvent, rapid evaporation of the solvent in the drying step can be suppressed, and not only can a uniform composition layer be formed, but also the environmental load is excellent.

  Here, the aqueous solvent is soluble in water or water such as alcohols such as methanol, ethanol, isopropyl alcohol and butanol, ketones such as acetone and methyl ethyl ketone, and glycols such as ethylene glycol, diethylene glycol and propylene glycol. Refers to an organic solvent mixed in an arbitrary ratio.

  The method for applying the resin composition to the polyester film is preferably an in-line coating method. The in-line coating method is a method of performing application in a process of manufacturing a polyester film. Specifically, it refers to a method in which coating is performed at any stage from melt extrusion of a polyester resin to biaxial stretching, heat treatment, and winding, and is generally substantially non-reflective obtained by melt extrusion and quenching. Unstretched (unoriented) polyester film (A film) in a crystalline state, then uniaxially oriented (uniaxially oriented) polyester film (B film) stretched in the longitudinal direction, or biaxially stretched in the width direction before heat treatment It is applied to any of stretched (biaxially oriented) polyester films (C films).

  In the present invention, the resin composition is applied to any one of the above-mentioned A film and B film before the completion of the crystal orientation, and then the polyester film is monoaxially or biaxially stretched, and the solvent It is preferable to adopt a method of performing a heat treatment at a temperature higher than the boiling point to complete the crystal orientation of the polyester film and provide a resin layer. According to this method, the production of the polyester film and the application and drying of the resin composition (that is, the formation of the resin layer) can be performed at the same time. Further, since the stretching is performed after the application, it is easy to make the thickness of the resin layer thinner.

  Among them, a method in which a resin composition is applied to a film (B film) uniaxially stretched in a longitudinal direction, and then stretched in a width direction and heat-treated is excellent. After applying to an unstretched film, since the stretching step is one time less than the method of biaxial stretching, it is difficult to generate defects and cracks in the composition layer due to stretching, and a composition layer excellent in transparency and smoothness is formed. This is because it can be formed.

  In the present invention, the resin layer is preferably provided by an inline coating method from the above various advantages. Here, as a method of applying the resin composition to the polyester film, any known method such as a bar coating method, a reverse coating method, a gravure coating method, a die coating method, and a blade coating method can be used.

  Therefore, the best method of forming a resin layer in the present invention is a method of applying a resin composition using an aqueous solvent on a polyester film by using an inline coating method, followed by drying and heat treatment. More preferably, a method of in-line coating the resin composition on the B film after uniaxial stretching. In the method for producing a laminated film of the present invention, drying can be performed at a temperature in the range of 80 to 130 ° C. in order to complete the removal of the solvent from the resin composition. The heat treatment can be performed in a temperature range of 160 to 240 ° C. in order to complete the crystal orientation of the polyester film, complete the thermosetting of the resin composition, and complete the formation of the resin layer.

  Further, the solid content concentration of the resin composition is preferably 10% by weight or less. By setting the solid content concentration to 10% by weight or less, good coatability can be imparted to the resin composition, and a laminated film having a transparent and uniform composition layer can be manufactured.

  Note that the solid content concentration represents a ratio of the weight of the resin composition to the weight of the resin composition minus the weight of the solvent (that is, [solid content concentration] = [( Weight)-(weight of solvent)] / [weight of resin composition]).

  Next, the method for producing a laminated film of the present invention will be described by taking, as an example, a case where a polyethylene terephthalate (hereinafter, PET) film is used as a polyester film, but is not limited thereto. First, PET pellets are sufficiently vacuum-dried, then supplied to an extruder, melt-extruded into a sheet at about 280 ° C., and cooled and solidified to produce an unstretched (unoriented) PET film (A film). This film is stretched 2.5 to 5.0 times in the longitudinal direction by a roll heated to 80 to 120 ° C. to obtain a uniaxially oriented PET film (B film). One side of the B film is coated with the resin composition of the present invention prepared at a predetermined concentration.

  At this time, a surface treatment such as a corona discharge treatment may be performed on the application surface of the PET film before the application. By performing surface treatment such as corona discharge treatment, the wettability of the resin composition to the PET film is improved, repelling of the resin composition is prevented, and a resin layer having a uniform coating thickness can be formed. After the application, the end of the PET film is gripped with a clip and guided to a heat treatment zone (preheating zone) at 80 to 130 ° C. to dry the solvent of the resin composition. After drying, the film is stretched 1.1 to 5.0 times in the width direction. Subsequently, it is led to a heat treatment zone (heat fixation zone) of 160 to 240 ° C. and heat treated for 1 to 30 seconds to complete the crystal orientation.

  In this heat treatment step (heat fixing step), a relaxation treatment of 3 to 15% may be performed in the width direction or the longitudinal direction as necessary. The laminated film thus obtained is a laminated film that is transparent, has excellent antistatic properties, and has excellent interference spot suppression properties (visibility) when a high refractive index hard coat layer is laminated.

  The thickness of the resin layer in the present invention is preferably 10 nm or more and 80 nm or less. More preferably, it is 10 nm or more and 50 nm or less, and still more preferably 10 nm or more and 40 nm or less. By setting the thickness of the resin layer to 10 nm or more and 80 nm or less, it is possible to sufficiently exhibit interference spot suppression properties and antistatic properties.

[Method of measuring characteristics and evaluating effect]
The method for measuring characteristics and the method for evaluating effects in the present invention are as follows.

(1) Haze and Transparency The haze was measured in a normal state (23 ° C., 50% relative humidity) after leaving the laminated film sample for 40 hours, using a turbidity meter “NDH5000” manufactured by Nippon Denshoku Industries Co., Ltd. And JIS
K 7136 "Method for determining haze of transparent material" (2000 version). The measurement was performed by irradiating light from the surface of the sample on which the resin layer was laminated. As samples, ten square samples each having a side of 50 mm were prepared, and each sample was measured once, and the average value measured ten times was defined as the haze value of the sample.
Further, the transparency was evaluated in four steps based on the haze value. C is a practically problematic level, B is a practical level, and A and S are good.
S: 0.6% or less A: More than 0.6% and 1.0% or less B: More than 1.0% and 1.5% or less C: More than 1.5%

(2) Reflectance A film sheet cut into an A4 cut size was divided into three parts in each of length and width, and a total of nine points were used as measurement samples. The long side was the longitudinal direction. For the measurement of the spectral reflectance, a 50 mm-wide black glossy tape (vinyl tape No. 200-50-21: black, manufactured by Yamato Co., Ltd.) is not caught by air bubbles on the back surface of the measurement surface (the resin layer). After the sample and the tape were aligned in the longitudinal direction, the sample was cut into approximately 4 cm square pieces, and the spectral reflectance at an incident angle of 5 ° was measured with a spectrophotometer (UV2450, manufactured by Shimadzu Corporation). did. The direction in which the sample was set on the measuring instrument was such that the longitudinal direction of the sample was aligned with the front and rear directions toward the front of the measuring instrument. In order to standardize the reflectance, an attached Al ₂ O ₃ plate was used as a standard reflection plate. As the reflectance, the reflectance on the resin layer side at a wavelength of 550 nm was obtained. In addition, the average value of 10 points was used for the measured value.

(3) Adhesiveness to laminate (3-1) Initial adhesiveness A UV-curable resin mixed at the following ratio on the resin layer side of the laminated film was cured using a bar coater to a thickness of 2 μm. It was evenly applied.
<Adjustment of hard coat agent>
-Titanium dioxide fine particles (TTO-55B, manufactured by Ishihara Sangyo Co., Ltd.): 30 parts by weight-Carboxylic acid group-containing monomer (Aronix M-5300, manufactured by Toagosei Co., Ltd.): 4.5 parts by weight-Cyclohexanone: 65. 5 parts by weight The above mixture was dispersed by a sand grinder mill to prepare a dispersion of titanium dioxide fine particles having an average particle diameter of 55 nm.

Dipentaerythritol hexaacrylate (DPHA, manufactured by Nippon Kayaku Co., Ltd.) and a photoinitiator (Irgacure 184, manufactured by Ciba Geigy Co., Ltd.) were added to a dispersion of the titanium dioxide fine particles in an amount of 100 parts by weight of dipentaerythritol hexaacrylate. 5 wt% of the hard coat layer was added and mixed to adjust the refractive index of the hard coat layer to 1.65.
Next, with a condensing high-pressure mercury lamp (H03-L31, manufactured by Eye Graphics Co., Ltd.) having an irradiation intensity of 120 W / cm set at a height of 9 cm from the surface on which the UV-curable resin layer was laminated, the integrated irradiation intensity was Ultraviolet rays were irradiated at 300 mJ / cm ² and cured to obtain a hard coat laminated polyester film in which a hard coat layer was laminated on the laminated polyester film. In addition, an industrial UV checker (UVR-N1 manufactured by Nippon Battery Co., Ltd.) was used for measuring the integrated irradiation intensity of ultraviolet rays. With respect to the obtained hard coat laminated polyester film, 100 cross cuts of 1 mm ² were put on the hard coat laminated surface of the obtained hard coat laminated polyester film, and “Cellotape” (registered trademark) (manufactured by Nichiban Co., Ltd., CT405AP) ) Was applied and pressed with a hand roller at a load of 1.5 kg / cm ² , and then rapidly peeled in a 90 ° direction with respect to the hard-coated laminated polyester film. Adhesion was evaluated in four steps based on the number of remaining grids. The evaluation was performed with the average value of 10 times. C is a practically problematic level, B is a practical level, and A and S are good.
S: 90 to 100 remaining A: 80 to 89 remaining B: 50 to 79 remaining C: 0 to less than 50 remaining

(3-2) Wet heat adhesiveness (3-1) After obtaining a hard coat laminated polyester film in the same manner as in the initial adhesiveness, it is stored for 240 hours in a high temperature and high humidity environment (temperature 85 ° C, relative humidity 85%), A hard coat laminated polyester film after the wet heat treatment was obtained. With respect to the hard coat laminated polyester film after the wet heat treatment, 100 1 mm ² cross cuts were put on the hard coat laminated surface of the hard coat laminated polyester film, and “Cellotape” (registered trademark) (Nichiban Co., Ltd., CT405AP) Was pressed with a hand roller at a load of 1.5 kg / cm ² , and then rapidly peeled in a 90 ° direction with respect to the hard coat laminated polyester film. Adhesion was evaluated in four steps based on the number of remaining grids. The evaluation was performed with the average value of 10 times. C is a practically problematic level, B is a practical level, and A and S are good.
S: 90 to 100 remaining A: 80 to 89 remaining B: 50 to 79 remaining C: 0 to less than 50 remaining

(4) Antistatic properties (surface resistivity)
The antistatic property was measured by a surface resistivity value. The surface resistivity was measured at 23% relative humidity for 24 hours, using a digital ultra-high resistance / micro ammeter R8340A (manufactured by Advantest Co., Ltd.) in that atmosphere and applying an applied voltage of 100 V for 10 seconds. A measurement was made. The unit is Ω / □. The resin laminated surface of the laminated sample was evaluated, and the average value measured ten times in total was defined as the surface resistivity value (R1) of the sample.
1 × 10 ¹¹ Ω / □ or less is good, and 1 × 10 ¹² Ω / □ or less is a practical level, and 1 × 10 ¹² Ω / □ is a practically problematic level.

(5) Number average particle diameter The number average particle diameter of the metal oxide particles (A) was determined by observing the cross-sectional structure of the laminated film with a transmission electron microscope (TEM). The magnification was set to 500,000, and the outer diameter of 10 particles present in the screen was measured for a total of 100 particles in 10 visual fields, and the average particle diameter was determined. If 10 particles do not exist in the screen, observe another part under the same conditions, measure the outer diameter of the particles existing in the screen, and measure the outer diameter of 100 particles in total. And averaged. Here, the outer diameter refers to the maximum diameter of the particle (that is, the longest diameter of the particle and indicates the longest diameter in the particle). Similarly, in the case of a particle having a cavity inside, the maximum diameter of the particle is also referred to as the outer diameter. Represent.

(6) Thickness of Resin Layer The thickness of the resin layer on the polyester film was measured by observing the cross section using a transmission electron microscope (TEM). As for the thickness of the resin layer, the thickness of the resin layer was read from an image photographed at a magnification of 200,000 by TEM. A total of 20 resin layer thicknesses were measured and averaged.

(7) Interference spot suppressing property In the same manner as in (3), a hard coat laminated polyester film in which a 2 μm thick hard coat layer (refractive index: 1.65) was laminated on the laminated polyester film was obtained.
Next, a sample having a size of 8 cm (width direction of the laminated polyester film) × 10 cm (longitudinal direction of the laminated polyester film) was cut out from the obtained laminated film for optics, and a black glossy tape (Yamato Co., Ltd.) was formed on the opposite surface of the hard coat layer. ), Vinyl tape No. 200-50-21: black) were stuck together so that air bubbles were not caught.
This sample was placed in a dark room with a three-wavelength fluorescent lamp (manufactured by Panasonic Corporation, three-wavelength neutral white (FL)
15EX-N 15W)), placed 30 cm directly below, visually observed the degree of interference spots while changing the viewing angle, and evaluated as follows. A or more were evaluated as good.
S: Interference spots are almost invisible A: Interference spots are slightly visible B: Weak interference spots are visible
C: The interference spot is strong.

(8) Boiling test A laminated film sample was cut into a size of 10 cm x 10 cm to obtain a reflectance evaluation sample after the boiling test. After the sample was fixed to a clip and suspended, it was placed in a boiling water (100 ° C.) of pure water prepared in a beaker for 2 hours with the entire surface of the laminated film immersed. Thereafter, the reflectance evaluation sample after the boiling test was taken out, dried at an air flow rate of 1 m / min for 30 minutes to remove moisture, and dried at normal temperature (23 ° C., relative humidity 65%) for 12 hours. Was obtained.

(9) Surface energy change Δγ of resin layer before and after boiling test
(9-1) Method for calculating surface energy The laminated film was left in an atmosphere at room temperature of 23 ° C and a relative humidity of 65% for 24 hours. Then, under the same atmosphere, the contact angles of the four types of solutions of pure water, ethylene glycol, formamide, and diiodomethane were measured with respect to the resin layer (X) side surface of the laminated film using a contact angle meter CA-D ( (Kyowa Interface Science Co., Ltd.). The average value of the three measured values excluding the maximum value and the minimum value of the five measured values is defined as the contact angle of each solution.

Next, using a contact angle of the resulting four kinds of solutions, the proposed "solid surface free energy (gamma) a dispersion force component by Hatakera (gamma _{S ^d),} polar force component (γ _S ^p) , and separated into three components of the hydrogen bond force component (gamma _S ^h), the geometric mean method based on equations that extends Fowkes equation (extended Fowkes equation) "dispersion force of the present invention, polar forces, and dispersion forces and Calculate the surface energy, which is the sum of the polar forces.

A specific calculation method will be described. The meaning of each symbol is described below. When γ _S ^L is the tension at the interface between the solid and the liquid, Expression (1) holds.

    γ_S ^L: Surface free energy of the resin layer (X) and the known solution described in Table 1.
    γ_S: Surface free energy of resin layer (X)
    γ_L: Surface free energy of the known solution described in Table 1.
    γ_S ^d: Dispersion component of surface free energy of resin layer (X)
    γ_S ^p: Polar force component of surface free energy of resin layer (X)
    γ_S ^h: Hydrogen bonding force component of surface free energy of resin layer (X)
    γ_L ^d: Dispersion component of the surface free energy of the known solution described in Table 1.
    γ_L ^p: Polar force component of the surface free energy of the known solution described in Table 1.
    γ_L ^h: Hydrogen bonding force component of the surface free energy of the known solution described in Table 1.
γ_S ^L= Γ_S+ Γ_L-2 (γ_S ^d・ Γ_L ^d)^1/2-2 (γ_S ^p・ Γ_L ^p)^1/2-2 (γ_S ^h・ Γ_L ^h)^1/2  ... Equation (1).

  In addition, the state when the droplet is in contact with the smooth solid surface at the contact angle (θ) is expressed by the following equation (Young's equation).

^{_{γ S = γ S L + γ}} L cosθ ··· equation (2).

By combining these equations (1) and (2), the following equation is obtained.
_{^{(γ S d · γ L d}} ) 1/2 + (γ S p · γ L p) 1/2 + (γ S h · γ L h) 1/2 = γ L (1 + cosθ) / 2 ··· formula (3).

  Actually, the contact angles (θ) and the components (γ) of the surface tensions of the known solutions described in Table 1 were applied to four types of solutions of water, ethylene glycol, formamide, and diiodomethane._L ^d, Γ_L ^p, Γ_L ^h) Is substituted into Equation (3) to solve four simultaneous equations. As a result, the surface free energy (γ) of the solid, that is, the surface free energy of the resin layer (X) surface is calculated.

(9-2) Surface energy change Δγ before and after boiling treatment
Absolute value of the value obtained by subtracting the surface energy of the resin layer before the boiling test from the surface energy of the resin layer after the boiling test (Δγ = | surface energy of the resin layer after the boiling test-resin layer before the boiling test) Of the surface energy |). As a sample for evaluation after the boiling treatment test, a sample obtained according to the method of (8) was used. A or more were evaluated as good.
S: 3 mN / m or less A: More than 3 mN / m and 5 mN / m or less B: More than 5 mN / m and 7 mN / m or less C: More than 7 mN / m

(10) Surface roughness (arithmetic average roughness: Ra)
The surface obtained by measuring the resin layer side of the laminated film at a measurement range of 10 μm × 10 μm, 512 measurement lines, 512 measurement lines, and a measurement rate of 1.0 Hz in a ScanAsyst Air mode of an atomic force microscope “Dimension Icon ScanAsyst” manufactured by BRUKER. From the information, the arithmetic average roughness (Ra) was calculated by the method specified in JIS-B-0601-1994. Specifically, “NanoScope Analysis” is used as software, “3rd” of “Flatten Order” is selected, and three-dimensional swell processing is performed. Thereafter, “Roughness” is selected, and the numerical value described in “Image Ra” on the screen is set as the arithmetic average roughness. In addition, measurement was performed ten times in total, and the average value of a total of eight data excluding the maximum value and the minimum value was defined as the arithmetic average roughness (Ra) of the sample.
The arithmetic average roughness was evaluated in four steps. C is a practically problematic level, B is a practical level, and A and S are good.
S: 10 nm or less A: More than 10 nm and 15 nm or less B: More than 15 nm and 20 nm or less C: More than 20 nm

(11) Composition Analysis of Resin Layer The composition analysis of the resin layer was performed on the surface of the laminated film using an X-ray photoelectron spectrometer (ESCA), a Fourier infrared spectrophotometer (FT-IR) ATR method, and a time-of-flight secondary. The measurement was performed by an ion gravimetric analyzer (TOF-SIMS). Further, the resin layer is dissolved and extracted with a solvent, separated by chromatography, and then subjected to proton nuclear magnetic resonance spectroscopy ( ¹ H-NMR), carbon nuclear magnetic resonance spectroscopy ( ¹³ C-NMR), and Fourier infrared spectroscopy. The structure was analyzed by a photometer (FT-IR), and pyrolysis gas chromatography-weight analysis (GC-MS) was performed to analyze the composition of the resin layer. By the above method, the presence or absence of the metal oxide particles (A), the π-electron conjugated polymer compound (B), the epoxy compound (C), the acrylic resin (D), and the ion conductive compound (E) in the resin layer is confirmed. did. When the above compound was contained in the resin layer, it was A, and when it was not contained, it was B.

(12) Antistatic property after lamination of high refractive index hard coat (surface resistivity)
In the same manner as in (3), a hard coat laminated polyester film having a 2 μm thick hard coat layer (refractive index: 1.65) laminated on the laminated polyester film was obtained. The surface resistivity of the hard coat layer surface of the hard coat laminated polyester film was measured. The measurement of the surface resistivity was performed by the method described in (4), and the average value measured five times in total was taken as the surface resistivity of the sample, and those of B or more were evaluated as good.
A: 1 × 10 ¹² Ω / □ or less B: More than 1 × 10 ¹² Ω / □, 1 × 10 ¹³ Ω / □ or less C: More than 1 × 10 ¹³ Ω / □ A is good, and B is P is a practical level, and C is a practically problematic level.

(13) Antistatic properties (charge amount) after lamination of high refractive index hard coat
On the resin layer side of the laminated film, (3-1) the same UV curable resin as that used in the initial adhesion is uniformly applied using a bar coater so that the cured film thickness becomes 2 μm, and then rolled. The film roll was wound into a shape, and a hard coat laminated film was wound. Thereafter, the potential of the hard coat layer surface was measured at a position 5 cm away from the unwinding surface when the wound hard coat laminated film roll was unwound. The charge amount was measured using STATION TYPE-TH manufactured by Shisido Electric Co., Ltd., and the average value measured five times in total was defined as the charge amount of the sample.
A: The absolute value of the potential is 2 kV or less. B: The absolute value of the potential exceeds 2 kV, and 5 kV or less. C: The absolute value of the potential exceeds 5 kV.

Reference Example 1 π-electron conjugated polymer compound (B-1)
7.18 parts by weight of an aqueous solution containing 20.8 parts by weight of polystyrenesulfonic acid as an acidic polymer compound, 49 parts by weight of a 1% by weight aqueous solution of iron (III) sulfate, and 3,4-ethylenedioxythiophene as a thiophene compound. 8 parts by weight and 117 parts by weight of a 10.9% by weight aqueous solution of peroxodisulfuric acid were added. The mixture was stirred at 18 ° C. for 23 hours. Next, 154 parts by weight of a cation exchange resin and 232 parts by weight of an anion exchange resin were added to the mixture, and the mixture was stirred for 2 hours. Then, the ion exchange resin was filtered off to obtain poly (3,4-ethylenedioxythiophene). ) And polystyrene sulfonic acid to obtain an aqueous dispersion (solid content: 1.3% by weight).

<Reference Example 2> Preparation of mixture (AD) of metal oxide particles (A) and acrylic resin (D) In a normal acrylic resin reaction tank equipped with a stirrer, a thermometer, and a reflux condenser, isopropyl alcohol 100 was used as a solvent. Then, the mixture was heated, stirred and maintained at 100 ° C. Among them, (meth) acrylate (d1 ′) has 40 parts of nonadecyl methacrylate with n = 19, (meth) acrylate (d2 ′) has 40 parts of isobonyl methacrylate having two rings, and has a carboxyl group. As (meth) acrylate (d3 '), a mixture composed of 20 parts of methacrylic acid was dropped over 3 hours. After completion of the dropwise addition, the mixture was heated at 100 ° C. for 1 hour, and then an additional mixed catalyst solution consisting of 1 part of t-butylperoxy-2-ethylhexaate was charged. Next, the mixture was heated at 100 ° C. for 3 hours and then cooled to obtain an acrylic resin (D).

  Next, an aqueous dispersion of zirconium oxide particles (A) (zirconium oxide dispersion SZR-CW manufactured by Sakai Chemical Industry Co., Ltd., number average particle diameter of zirconium oxide 20 nm) in an aqueous solvent and the acrylic resin (D ) Were added in order and dispersed by the following method to obtain a mixture of particles (A) and acrylic resin (D). (Method (ii) above) The addition ratio (weight ratio) of the metal oxide particles (A) and the acrylic resin (D) was (A) / (D) = 100/20 (where the weight ratio was , Rounded to the first decimal place). The dispersion treatment was performed by using a homomixer, and rotating at a peripheral speed of 10 m / s for 5 hours. The weight ratio of the particles (A) to the acrylic resin (D) in the finally obtained mixture was (A) / (D) = 100/20 (the weight ratio is the first decimal point). Rounded off).

  The obtained particles (AD) were centrifuged with a Hitachi tabletop ultracentrifuge (Hitachi Koki Co., Ltd .: CS150NX) (3,000 rpm, separation time 30 minutes) to obtain metal oxide particles (AD). A) (and the acrylic resin (D) adsorbed on the surface of the metal oxide particles (A)) was allowed to settle, the supernatant was removed, and the precipitate was concentrated to dryness. The concentrated and dried precipitate was analyzed by X-ray photoelectron spectroscopy (XPS). As a result, it was confirmed that the acrylic resin (D) was present on the surface of the metal oxide particles (A). That is, the acrylic resin (D) is adsorbed and adhered to the surface of the metal oxide particles (A), and the obtained particles (AD) are applied to the surface of the metal oxide particles (A) by the acrylic resin (D). It turned out that it corresponds to the particle which has a.

<Reference Example 3> Preparation of ion conductive compound (lithium polystyrenesulfonate (E-1)) Under a nitrogen gas atmosphere and normal temperature (25 ° C), 200 parts by weight of water and 1 part by weight of ammonium persulfate were placed in container 1. This was charged and heated to 85 ° C. and dissolved to obtain a solution 1 at 85 ° C.

    At room temperature (25 ° C.), 100 parts by weight of lithium styrenesulfonate, 3 parts by weight of ammonium persulfate, and 100 parts of water were added to the container 2 to obtain a solution 2.

  Under a nitrogen gas atmosphere, the solution 1 was transferred to the reactor, and the solution 2 was continuously dropped into the solution 1 over 4 hours while maintaining the temperature of the solution in the reactor at 85 ° C. After completion of the dropwise addition, the mixture was further stirred for 3 hours, and then cooled to 25 ° C. to obtain lithium polystyrenesulfonate (E-1).

Tables 1 to 4 show the properties and the like of the laminated films obtained in the following Examples and Comparative Examples. Hereinafter, Examples 6, 8, 9, 26 to 28 shall be read as Reference Examples 6, 8, 9, 26 to 28.

<Example 1>
First, a resin composition 1 was prepared as follows.
<Resin composition>
The particles (A), the acrylic resin (D), the π-electron conjugated polymer compound (B) and the epoxy compound (C) are added in this order to the aqueous solvent, and mixed in the ratio shown in Table 1 to obtain the resin. A composition was obtained.・ A mixture (AD) of particles (A) and acrylic resin (D)
・ Π electron conjugated polymer compound (B)
Epoxy compound (C): polyglycerol polyglycidyl ether-based epoxy cross-linking agent (Nagase Chemtech Co., Ltd.'s "Denacol (registered trademark)" EX-512 (molecular weight: 630, epoxy equivalent: 168, water solubility: 100%)
<Laminated film>
Next, PET pellets substantially containing no particles (intrinsic viscosity: 0.63 dl / g) are sufficiently dried in a vacuum, fed to an extruder, melted at 285 ° C., extruded into a sheet shape from a T-shaped die, and squeezed. It was wound around a mirror-surface casting drum having a surface temperature of 25 ° C. using an electric application casting method to be cooled and solidified. This unstretched film was heated to 90 ° C. and stretched 3.4 times in the longitudinal direction to obtain a uniaxially stretched film (B film).

Next, the resin composition 1 was applied to the corona discharge treated surface of the uniaxially stretched film with a coating thickness of about 6 μm using a bar coater. Both ends in the width direction of the uniaxially stretched film coated with the resin composition are gripped with clips and led to a preheating zone. After the atmosphere temperature is set to 75 ° C., the atmosphere temperature is subsequently set to 110 ° C. using a radiation heater, and then the atmosphere temperature is set. At 90 ° C., and the resin composition was dried to form a resin layer. Subsequently, the film is stretched 3.5 times in the width direction continuously in a heating zone (stretching zone) at 120 ° C., and subsequently subjected to a heat treatment in a heat treatment zone (thermosetting zone) at 230 ° C. for 20 seconds to complete the crystal orientation. Got. In the obtained laminated film, the thickness of the PET film was 100 μm, and the thickness of the resin layer was about 0.02 μm. Table 3 shows the properties and the like of the obtained laminated film.
The haze was low, the reflectance was high, the amount of change in surface energy and the surface resistivity were small, and the film was excellent in transparency, suppression of interference spots, adhesion, and antistatic properties.

<Examples 2 to 12>
A laminated film was obtained in the same manner as in Example 1, except that the ratio of the resin composition in the coating liquid was changed as shown in Table 1.
Table 1 shows the properties of the obtained laminated film.

<Examples 13 to 16>
Example 1 was repeated except that the number average particle diameter of the metal oxide particles (A) was changed to 3 nm (Example 13), 15 nm (Example 14), 30 nm (Example 15), and 50 nm (Example 16). A laminated film was obtained in the same manner. Table 1 shows the properties of the obtained laminated film.

<Example 17>
Except that the metal oxide particles (A) were changed to titanium oxide particles “NanoTek” (registered trademark) TiO ₂ slurry (C-I Kasei Co., Ltd., number average particle diameter 20 nm), a method similar to that of Example 1 was used. A laminated film was obtained. Table 1 shows the properties of the obtained laminated film.

<Examples 18 to 20>
Metal oxide particles (A) were zinc oxide particles FINEX-50 (manufactured by Sakai Chemical Industry Co., Ltd., number average particle diameter 20 nm) (Example 18), ITO slurry (manufactured by C I Kasei Co., Ltd., number average particles) 20 nm diameter (Example 19) and yttrium oxide “NanoTek” (registered trademark) Y ₂ O ₃ slurry (manufactured by C-I Kasei Co., Ltd., number average particle diameter 20 nm) (Example 20) A laminated film was obtained in the same manner as in Example 1. Table 1 shows the properties of the obtained laminated film.

<Examples 21 to 23>
A laminated film was obtained in the same manner as in Example 1, except that the thickness of the resin layer was changed to 10 nm (Example 21), 30 nm (Example 22), and 50 nm (Example 23). Table 1 shows the properties of the obtained laminated film.

<Example 24>
The (meth) acrylate monomer (d3 ′) was changed to N, N-dimethylaminoethyl methacrylate having a tertiary amino group (the R ₃ group of the monomer unit represented by the formula (3) does not have a carboxyl group) A laminated film was obtained in the same manner as in Example 1 except that an acrylic resin was used. Table 1 shows the properties of the obtained laminated film.

<Example 25>
The acrylic resin (D) was changed to an acrylic resin (manufactured by Nippon Carbide Co., Ltd., RX7013ED) (an acrylic having no monomer unit represented by the formula (1) and no monomer unit represented by the formula (2)) A laminated film was obtained in the same manner as in Example 1 except for using a resin. Table 1 shows the properties of the obtained laminated film.

<Example 26>
A laminated film was obtained in the same manner as in Example 1, except that zirconia chelate (Matsumoto Fine Chemical “Orgatics” (registered trademark) ZC300) was used instead of the metal oxide particles (A). Table 1 shows the properties of the obtained laminated film.

<Example 27>
A laminated film was produced in the same manner as in Example 1 except that an ion conductive compound (ammonium salt) (ADEKA Corporation, Adecakathioace PD50) was used instead of the π-electron conjugated polymer compound (B). Got. Table 1 shows the properties of the obtained laminated film.

<Example 28>
A laminated film was obtained in the same manner as in Example 1, except that an ion conductive compound (lithium styrene sulfonate) (E-1) was used instead of the π-electron conjugated polymer compound (B). Table 1 shows the properties of the obtained laminated film.

<Comparative Example 1>
Example 1 Except that the metal oxide particles (A) in Example 1 were changed to silica particles “Snowtex” (registered trademark) CM (manufactured by Nissan Chemical Industries, Ltd., number average particle diameter 20 nm). A laminated film was obtained in the same manner as described above. Table 1 shows the properties of the obtained laminated film.

<Comparative Examples 2-3>
The metal oxide particles (A) in Example 1 were mixed with MgF ₂ particles “NanoTek” (registered trademark) MgF ₂ slurry (manufactured by C-I Kasei Co., Ltd., number average particle diameter 20 nm) (Comparative Example 2), A laminated film was obtained in the same manner as in Example 1 except that silica particles were changed to “Sluria” (registered trademark) TR112 (manufactured by Nikki Shokubai Kasei Co., Ltd., number average particle diameter 20 nm) (Comparative Example 3). Was. Table 1 shows the properties of the obtained laminated film.

<Comparative Example 4>
A laminated film was obtained in the same manner as in Example 1, except that the π-electron conjugated polymer compound (B) in Example 1 was not used. As compared with Example 1, the surface resistivity was higher, and the same transparency, visibility, and adhesion to the laminate were exhibited, but the antistatic property was lacking.

<Comparative Example 5>
A laminated film was obtained in the same manner as in Example 1, except that a polyester resin (manufactured by Takamatsu Yushi, Pesresin A110) was used instead of the epoxy compound (C) in Example 1. Compared with Example 1, the use of the polyester resin resulted in a large change in surface energy after the boiling treatment, and lacked wet heat adhesiveness.

<Comparative Example 6>
A laminated film was obtained in the same manner as in Example 1 except that the acrylic resin (D) in Example 1 was not used. Compared with Example 1, by using no acrylic resin, the change in surface energy after the boiling treatment was large, and the wet heat adhesion was lacking.

<Comparative Example 7>
A laminated film was obtained in the same manner as in Example 1 except that the thickness of the resin layer in Example 1 was changed to 7 nm. As compared with Example 1, the surface resistivity was higher, and the same transparency, visibility, and adhesion to the laminate were exhibited, but the antistatic property was lacking.

  The present invention is a laminate having high transparency and high refractive index hard coat layer, and having excellent adhesion to the high refractive index hard coat layer and a high level of antistatic property regardless of humidity. The present invention relates to a film, and can be used for an optically-friendly adhesive film for display use.

Claims (10)

A laminated film in which a resin layer is provided on at least one side of a polyester film, the reflectance of the resin layer surface at a wavelength of 550 nm is 6.0% or more, and the surface specific resistance value of the resin layer surface is 10 ¹² Ω. / □ or less, and the surface energy change Δγ (Δγ = | surface energy of resin layer after boiling treatment test−surface energy of resin layer before boiling treatment test |) of the resin layer surface before and after the boiling test is 5 mN / m Ri der below,
The resin layer contains metal oxide particles (A), a π-electron conjugated polymer compound (B), an epoxy compound (C), and an acrylic resin (D);
Lamination content of the epoxy compound (C) in the resin layer, characterized in 20-60 parts by weight der Rukoto when the content of the metal oxide particles in the resin layer (A) as 100 parts by weight the film. The laminated film according to claim 1, wherein the arithmetic average roughness (Ra) of the surface of the resin layer is 20 nm or less. The laminated film according to claim 1 or 2, wherein the resin layer of the metal oxide particles (A) is a number average particle diameter is characterized by 50nm or less of the metal oxide particles (A) der Rukoto than 3 nm. The laminated film according to any one of claims 1 to 3, wherein the content of the metal oxide particles (A) in the resin layer is 30% by weight or more and 90% by weight or less based on the entire resin layer. . The laminated film according to any one of claims 1 to 4, wherein the metal oxide particles (A) are particles having the acrylic resin (D) on a surface thereof. The metal oxide particles (A) are made of TiO ₂ , ZrO ₂ , ZnO, CeO ₂ , SnO ₂ , Sb ₂ O ₅ , Indium-doped tin oxide (ITO), phosphorus-doped tin oxide (PTO), Y ₂ O ₃ , La ₂ O ₃ , Al ₂ O ₃ The laminated film according to any one of claims 1 to 5, comprising at least one member selected from the group consisting of: Laminate film according to the metal oxide particles (A) is any one of claims 1 to 6 is a titanium oxide particle (A _{1 ')} and / or zirconium oxide particles (A _2'). The acrylic resin (D) includes a monomer unit (d1) represented by the formula (1), a monomer unit (d2) represented by the formula (2), and a monomer unit (d3) represented by the formula (3). The laminated film according to any one of claims 1 to 7, wherein the resin is a resin having:

(In the formula (1), the R ₁ group represents a hydrogen atom or a methyl group, and n represents an integer of 9 or more and 34 or less.)

(In the formula (2), the group R ₂ represents a hydrogen atom or a methyl group. The group R ₄ represents a group containing two or more saturated carbon rings.)

(In the formula (3), the R ₃ group represents a hydrogen atom or a methyl group. The R ₅ group is a hydroxyl group, a carboxyl group, a tertiary amino group, a quaternary ammonium base, a sulfonic acid group, or a phosphoric acid group. Represents a group.)   The laminated film according to any one of claims 1 to 8, wherein the resin layer has a thickness of 10 to 80 nm. A method for producing a laminated film provided with a resin layer on at least one side of a polyester film,
The resin layer contains metal oxide particles (A) having a number average particle diameter of 3 nm or more and 50 nm or less, a π-electron conjugated polymer compound (B), an epoxy compound (C), and an acrylic resin (D). After applying the resin composition to at least one side of the polyester film, is a layer formed by drying,
The content of the epoxy compound (C) in the resin composition is 20 to 60 parts by weight when the content of the metal oxide particles (A) in the resin composition is 100 parts by weight. Method for producing a laminated film.