JP2017052273A - Laminated film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated film which can obtain a film roll having a good winding appearance when wound in a roll state while suppressing haze to be low though being a film in which air of the surface is hard to be removed in constituting the structure, and has excellent winding properties and transparency.SOLUTION: A laminated film has such a structure (hereinafter referred to as A/B laminated structure) that 250 or more layers of a layer made from a resin A (hereinafter referred to as A layer) and a layer made from a resin B (hereinafter referred to as B layer) are alternately laminated in a thickness direction, has a coating layer (hereinafter referred to as C layer) containing easily sliding particles on at least one surface, and satisfies all of the following (1) to (3): (1) average reflectance having a wavelength section of 380 nm to 500 nm of 25% or more and average reflectance having a wavelength section of 500 nm to 1,200 nm of less than 15%; (2) film haze of less than 1%; and (3) air leakage index of the surface of the C layer of 200 s or more and less than 1,500.SELECTED DRAWING: None

Description

The present invention relates to a laminated film having excellent winding properties, transparency, and antistatic properties.

  In films used for optical and decorative applications, the base film has excellent transparency by keeping the haze low while maintaining excellent air release (winding) and slipping (conveyance) properties. It is requested.

In such a case, in a film composed of a single layer to several layers, for example, as a means for achieving good air bleedability and slipperiness, for example, a specific surface of a film substantially free of inert particles is specified. A coating film containing a specific amount of particles having an average particle diameter is provided, and the ratio of the average particle diameter of the particles and the thickness of the coating film layer are set to specific values, so that the surface is extremely flat and has excellent transportability. And the laminated | multilayer film with favorable winding-up property and an electromagnetic conversion characteristic is proposed (patent document 1).
In addition, it is possible to give unique properties by having a multilayer structure such as an improvement in light interference and reflection in a laminated film in which the number of laminated resins is several tens of layers or more, for example, different refractive indexes. By alternately laminating resin layers, interference interference of light is exhibited, and the performance as a filter or a reflection member that selectively reflects a specific wavelength is maintained, while the color purity is reduced due to higher-order reflections. There has been proposed a laminated film capable of suppressing coloration and deterioration due to ultraviolet scattering (Patent Document 2).

However, in the laminated film as in Patent Document 2, an amorphous polymer having a low elastic modulus is often used for the low refractive index layer, and the elastic modulus of the entire film tends to be low. Is located near the surface of the film, so that the air on the surface is less likely to escape compared to a general-purpose film, and the particle design on the surface is not sufficient. It was happening.
In the structure of the laminated film of Patent Document 1, it is difficult to keep the film haze low, and it is difficult to apply the structure to the laminated film of Patent Document 2. Also, from the viewpoint of windability, the structure of the laminated film of Patent Document 1 is not sufficient for application to a laminated film in which air is difficult to escape.
Moreover, in order to prevent the yield reduction by dust adhesion at the time of processing a film, the laminated | multilayer film which provided the antistatic property is proposed (patent document 3), but screen protection of a capacitive touch panel is proposed. When the film is used as a film, if the surface specific resistance value is too low, there is a problem that malfunction occurs in touch panel operation.

Japanese Patent Laid-Open No. 9-66591 JP 2005-288784 A Japanese Patent Laying-Open No. 2015-68996

  The present invention provides a haze by providing a coating layer containing particles having a particle size suitable for the surface layer and controlling the addition amount of the antistatic agent, although it is a laminated film in which the air on the film surface is particularly difficult to escape. It is an object of the present invention to provide a laminated film having an antistatic property capable of obtaining a good winding shape when wound in a roll shape while keeping it low, and achieving both dust prevention and touchpad operability.

In order to solve the above problems, the present invention has the following configuration.
By having a coating layer containing easy-to-slip particles with a controlled particle size on at least one surface of the surface layer of the laminated film, it is possible to prevent air leakage from the film surface while keeping the haze, which is an important characteristic for optical films, low. A means to improve is adopted. That is, a structure in which layers of resin A (hereinafter referred to as A layer) and layers of resin B (hereinafter referred to as B layer) are alternately laminated in the thickness direction in total 250 layers or more (hereinafter referred to as A / B layer laminated structure) And a coating film layer (hereinafter referred to as C layer) containing easy-slip particles on at least one surface, and satisfying all of the following (1) to (3) It is.

(1) The average reflectance in the wavelength section from 380 nm to 500 nm is 25% or more, and the average reflectance in the wavelength section from 500 nm to 1200 nm is less than 15%.
(2) The film haze is less than 1%.
(3) The air escape index on the surface of the C layer is 200 s or more and less than 1500 s.
Moreover, it is a laminated | multilayer film whose surface specific resistance of the said C layer surface is 1 * 10 < ¹¹ > ohm / square or more and less than 1 * 10 < ¹⁴ > ohm / square.

  By this invention, the laminated | multilayer film which has the outstanding winding property, transparency, and antistatic property can be obtained. As described above, it is possible to suppress an increase in manufacturing cost by preventing generation of rejected products due to winding deviation during film production and improving yield by preventing dust adhesion when processing a film. In addition, when the laminated film is used as a screen protective film for a capacitive touch panel, it is possible to prevent dust from adhering to the display without causing malfunction in touch panel operation.

The figure which shows the design layer thickness of Examples 1-5, 10-12, and Comparative Examples 1-6 The figure which shows the design layer thickness of Examples 6-9 and Comparative Examples 7 and 8

The laminated film of the present invention needs to have a structure in which a total of 250 or more layers consisting of resin A (hereinafter referred to as A layer) and resin B (hereinafter referred to as B layer) are alternately laminated in the thickness direction. It is. More preferred is a structure in which a total of 400 or more layers are alternately laminated in the thickness direction, and still more preferred is a structure in which 800 or more layers are laminated. In the case of less than 250 layers, in addition to not being able to achieve high reflectivity, the light of each wavelength in the reflection wavelength band cannot be reflected uniformly, resulting in a film with large unevenness for each reflection wavelength.
The two types of resins A and B in the present invention may be either a thermoplastic resin or a thermosetting resin, or a copolymer or a mixture of two or more types of resins. . Among them, it is preferable to use a thermoplastic resin, and it is particularly preferable to use a polyester resin from the viewpoints of strength, heat resistance, transparency, and versatility.

  As polyester, the polyester obtained by superposition | polymerization from the monomer which has aromatic dicarboxylic acid or aliphatic dicarboxylic acid and diol as a main component is preferable. Here, as the aromatic dicarboxylic acid, for example, terephthalic acid, isophthalic acid, phthalic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 4,4′- Examples thereof include diphenyl dicarboxylic acid, 4,4′-diphenyl ether dicarboxylic acid, 4,4′-diphenyl sulfone dicarboxylic acid, and the like. Examples of the aliphatic dicarboxylic acid include adipic acid, suberic acid, sebacic acid, dimer acid, dodecanedioic acid, cyclohexanedicarboxylic acid and ester derivatives thereof. Among them, terephthalic acid and 2,6-naphthalenedicarboxylic acid having a high refractive index are preferable. Only one kind of these acid components may be used, or two or more kinds may be used in combination, and further, an oxyacid such as hydroxybenzoic acid may be partially copolymerized. Examples of the diol component include ethylene glycol, 1,2-propanediol, 1,3-propanediol, neopentyl glycol, 1,3-butanediol, 1,4-butanediol, and 1,5-pentanediol. 1,6-hexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-hexanedimethanol, diethylene glycol, triethylene glycol, polyalkylene glycol, 2,2-bis (4- Hydroxyethoxyphenyl) propane, isosorbate, spiroglycol and the like. Of these, ethylene glycol is preferably used. These diol components may use only 1 type and may use 2 or more types together.

  Among the polyesters, polyethylene terephthalate and copolymers thereof, polyethylene naphthalate and copolymers thereof, polybutylene terephthalate and copolymers thereof, polybutylene naphthalate and copolymers thereof, and polyhexamethylene terephthalate and copolymers thereof. It is preferable to use a polymer, polyhexamethylene naphthalate, a copolymer thereof, and the like.

As a preferable combination of the resin A and the resin B selected from thermoplastic resins, it is preferable to use a resin containing the same basic skeleton as one of the resins. Here, the “basic skeleton” referred to in the present invention refers to a repeating unit constituting a resin. For example, when one resin is polyethylene terephthalate, ethylene terephthalate is the basic skeleton. Examples of the polymer include a polymer (copolymer) composed of an ethylene terephthalate unit and a cyclohexane 1,4-dimethylene terephthalate unit. As another example, when one resin is polyethylene, ethylene is a basic skeleton. When the resin having the same basic skeleton is used, problems such as stacking faults such as flow marks and peeling between layers are less likely to occur in the formation of a laminated film.
In the laminated film of the present invention, the resin A contains polyethylene terephthalate or polyethylene naphthalate as a main component, and the resin B contains at least one of spiroglycol, cyclohexanedicarboxylic acid, and cyclohexanedimethanol. Polyester is preferred.

  For the resin A in the present invention, it is preferable to use polyethylene terephthalate or polyethylene naphthalate from the viewpoints of stamping resistance (dentation resistance) and waist strength of the film itself.

  Resin B in the present invention contains isophthalic acid, naphthalenedicarboxylic acid, diphenyl acid, and cyclohexanedicarboxylic acid, or contains spiroglycol, cyclohexanedimethanol, bisphenoxyethanol fluorene, and bisphenol A component from the viewpoint of suppressing an increase in refractive index. It is preferable that the copolymer of the resin A contained is mixed with the resin A or used alone.

The figure which shows the design layer thickness is demonstrated as an example of the preferable layer structure of the laminated film in this invention. FIG. 1 shows a film in which layers made of two types of resins (hereinafter referred to as “resin A” and “resin B”) are alternately laminated in the thickness direction. Hereinafter, it is a diagram plotted against the layer number). The layer thickness corresponds only to the integer layer number in the figure, the A layer corresponds to the odd number, and the B layer corresponds to the even number.
In the laminated film of the present invention, the outermost thick film layer is preferably formed of an A layer in order to prevent fusion to a stretching roll or the like in the film forming process. Moreover, it is preferable that this outermost layer thickness is 1% or more and less than 40% with respect to film total thickness. More preferably, it is 3% or more and less than 25%. More preferably, it is 5% or more and less than 15%. If it is less than 1%, the air escape from the film surface is poor, and there is a possibility that winding deviation will occur when winding into a roll. In addition, a flow mark due to stacking failure may occur, and streaky defects may be seen on the film surface. When it is 40% or more, the stiffness of the laminated film becomes strong, which may adversely affect the handling during molding.

As shown in FIGS. 1 and 2, in the case of a layer configuration in which the thickness of a thin film layer of less than 1 μm increases and then decreases as it goes from one surface to the opposite surface, poor stacking occurs in a very small part. Even when deviating from the design value, since the same layer thickness exists in other portions, the reflection unevenness can be reduced. In addition, the layer structure changes from decrease to increase, and the portion corresponding to the boundary portion where change from increase to decrease is likely to cause a stacking failure and causes uneven reflection. It is preferable to provide an intermediate thick film layer having a certain thickness at the location. The intermediate thick film layer is preferably an A layer. When there is no intermediate thick film layer, uneven reflection of light at a specific wavelength is likely to occur due to poor stacking.
An important optical characteristic in the present invention is a selective reflection characteristic of light in a blue wavelength region (blue light). According to recent research, blue light having a light wavelength of 380 to 500 nm having the strongest energy in visible light reaches the retina without being absorbed by the cornea or the crystalline lens. May be damaged and cause eye disease “age-related macular degeneration”. Blue light has also been found to be a major factor in VDT syndrome such as eye strain and dry eye. LED displays used in personal computers and smartphones have a characteristic of having a strong peak in the blue wavelength region.
The laminated film of the present invention is mainly used in a screen protective film for the LED display obtained by using the laminated film and a decorative molded body such as a blue decorative design, mainly in a blue wavelength region. As a specific optical design, it is necessary that the average reflectance in the wavelength section from 380 nm to 500 nm is 25% or more and the average reflectance in the wavelength section from 500 nm to 1200 nm is less than 15%. .

  When the average reflectance at a wavelength of 380 to 500 nm is less than 25%, the reflection of the blue wavelength is not sufficient, and the reflection performance for the blue wavelength sufficient for the screen protection film application cannot be achieved. The design may be lacking due to lack of taste.

  When the average reflectance at a wavelength of 500 to 1200 nm is 15% or more, in the protective film application, the visible light reflectance considering the angle dependency is high, and the characters on the screen may not be clearly visible. Moreover, in the decoration use, designability may be lacking because coloring other than blue occurs.

The total film thickness in the present invention is preferably 10 μm or more and less than 110 μm. More preferably, it is 20 μm or more and less than 60 μm. More preferably, it is 30 μm or more and less than 55 μm. When the thickness is less than 10 μm, the film surface has poor air escape, and winding misalignment may occur when winding into a roll. In addition, the reflection band becomes narrow, and the entire region with a wavelength of 380 to 500 nm may not be reflected. In the case of 110 μm or more, the stiffness of the laminated film becomes strong, which may adversely affect the handling during molding.
The haze of the laminated film in the present invention needs to be less than 1%. More preferably, it is less than 0.7%. When the haze is 1% or more, in the screen protective film application, transparency is insufficient and visibility may be hindered. Moreover, in the decoration use, there exists a possibility of lacking in designability.
The air escape index on the surface of the C layer of the laminated film in the present invention needs to be 200 s or more and less than 1500 s. When the air release index is less than 200 s, the contact between the films becomes strong when winding in a roll shape, and wrinkles may occur. Moreover, when storing in a roll shape for a long period of time, blocking may occur between films. When the air release index is 1500 s or more, there is a possibility that winding deviation occurs on the roll end face and the surface layer when winding in a roll shape.
In the laminated film of the present invention, in order to obtain a good winding shape when winding the film into a roll shape, the air release property and the easy slipperiness of the surface are important. However, as a means for achieving the above, inclusion of particles in the resin A or the resin B is not preferable due to the influence on the optical characteristics due to the deterioration of the planarity of the laminated interface and the increase in haze, and is a particle-free system. It is necessary to provide a coating layer (hereinafter referred to as C layer) containing easy-slip particles on at least one surface of the A / B laminated structure.

  The laminated film of the present invention may be provided with a printed layer or a hard coat layer on the surface for the purpose of use, and preferably an easy adhesion layer is provided on the treated surface, and the C layer is an easy adhesion layer. Is preferred.

  The thickness of the C layer in the present invention is preferably 40 nm or more and less than 90 nm. If it is less than 40 nm, the particles may fall off, and sufficient air release and easy slipping may not be obtained. Moreover, the adhesiveness with respect to a printing layer and a hard-coat layer may deteriorate. If the thickness is 90 nm or more, the haze may not be kept low. In addition, the particles may be buried, and sufficient air release and easy slipping may not be obtained.

  The laminated film of the present invention is composed of at least one resin selected from an acrylic resin and a urethane resin. In the C layer having a coating layer thickness of 40 nm or more and less than 90 nm, the volume-based particle size distribution measurement of the slippery particles is performed. And plotting the horizontal axis as the particle diameter and the vertical axis as the abundance ratio of the particles, the obtained ratio chart of the slippery particles has two maxima, and one peak top of the maxima The diameter is preferably in the range of 250 nm to less than 350 nm, and the other peak top is preferably in the range of particle diameter of 100 nm to less than 200 nm.

The easy-sliding particles contained in the C layer in the present invention are measured by volume-based particle size distribution, and when the horizontal axis is plotted as the particle diameter and the vertical axis as the abundance ratio of the particles, the chart of the abundance ratio of the obtained particles is at least It has one maximum, and the peak top of the maximum is preferably in the range of particle diameters of 250 nm or more and less than 350 nm (particle diameter (i)). When the particle diameter (i) is less than 250 nm, sufficient air escape properties may not be obtained. When it is 350 nm or more, the haze may not be able to be kept low. In addition, the particle abundance chart has two maxima, and one peak top of the maxima is in the range of particle diameters of 250 nm or more and less than 350 nm, and the other peak top is in the range of particle diameters of 100 nm or more and less than 200 nm ( More preferably, the particle diameter (ii)). Thus, by adding two kinds of particles having different particle diameters, contact between films can be avoided and blocking can be suppressed. When the particle diameter (ii) is less than 100 nm, the film is completely buried in the coating layer, and the slipperiness may not occur. In the case of 200 nm or more, the particle size difference from the particle size (i) is small, the films contact each other, and blocking may occur between the films. Further, there is a possibility that particles fall off, and sufficient air release properties and easy slipping properties cannot be obtained.
The total amount of the slippery particles contained in the C layer in the present invention is preferably 1% by weight or more and less than 10% by weight with respect to the resin component of the coating layer. When the amount is less than 1% by weight, sufficient air release properties may not be obtained. If it is 10% by weight or more, the haze may not be kept low.

In the laminated film of the present invention, the surface specific resistance of the surface of the C layer is preferably in the range of 1 × 10 ¹¹ Ω / □ or more and less than 1 × 10 ¹⁴ Ω / □. It is 1.0 × 10 ¹² Ω / □ or more and particularly preferably less than 1.0 × 10 ¹³ Ω / □. By setting the surface specific resistance of the surface of the C layer within the above range, it is possible to prevent dust adhesion when processing the laminated film and improve the process yield. Further, when the laminated film is used as a screen protection film, dust adhesion to the display can be prevented. Recently, it can be suitably used for capacitive touch panel applications mounted on information devices such as smartphones and tablets. When it is less than 1.0 × 10 ¹¹ Ω / □, the conductivity is too high, and thus, when a screen protection film using the laminated film is attached to a capacitive touch panel display, a malfunction occurs in the touch panel operation. there is a possibility. In the case of 1.0 × 10 ¹⁴ Ω / □ or more, the process yield may be lowered due to dust adhesion when the laminated film is processed. In addition, when a screen protection film using the laminated film is attached to a display, dust or the like due to static electricity may adhere and impair the appearance.

  The resin constituting the C layer in the present invention is preferably at least one resin selected from an acrylic resin and a urethane resin. The glass transition point (hereinafter, Tg) of at least one resin selected from an acrylic resin and a urethane resin is not particularly limited, but is preferably 0 to 90 ° C, more preferably 10 to 80 ° C. When a resin having a low Tg is used, the heat-resistant adhesion tends to be inferior. On the other hand, when the resin is too high, the film-forming property may be inferior. The molecular weight of the resin is preferably 100,000 or more, more preferably 300,000 or more from the viewpoint of adhesiveness.

  The acrylic resin is preferably a copolymer selected from methyl methacrylate, ethyl acrylate, n-butyl acrylate, 2-hydroxyethyl acrylate, acrylamide, N-methylol acrylamide, glycidyl methacrylate, and acrylic acid.

  It is preferable to dissolve, emulsify or suspend the acrylic resin in water and use it as a water-based acrylic resin from the viewpoint of environmental pollution and explosion-proof properties during application. Such water-based acrylic resins are copolymerized with monomers having a hydrophilic group (such as acrylic acid, methacrylic acid, acrylamide, vinyl sulfonic acid and salts thereof), emulsion polymerization using reactive emulsifiers and surfactants, and suspension polymerization. It can be prepared by a method such as turbid polymerization or soap-free polymerization.

  The urethane resin is not particularly limited as long as it is a water-soluble or water-dispersible urethane resin having an anionic group, and the main component is obtained by copolymerizing a polyol compound and a polyisocyanate compound. It is. As the urethane resin, it is preferable to use a urethane resin whose affinity for water is increased by introducing a carboxylate group, a sulfonate group, or a sulfuric acid half ester base. The content of carboxylic acid group, sulfonic acid group, sulfuric acid half ester base or the like is preferably 0.5 to 15% by weight. Examples of the polyol compound include polyethylene glycol, polypropylene glycol, polyethylene / propylene glycol, polytetramethylene glycol, hexamethylene glycol, hexamethylene glycol, tetramethylene glycol, 1,5-pentanediol, diethylene glycol, triethylene glycol, polycaprolactone. Polyhexamethylene adipate, polytetramethylene adipate, trimethylolpropane, trimethylolethane, glycerin, acrylic polyol, and the like can be used.

  Examples of the polyisocyanate compound include tolylene diisocyanate, hexamethylene diisocyanate, phenylene diisocyanate, diphenylmethane diisocyanate, an adduct of tolylene diisocyanate and trimethylolpropane, an adduct of hexamethylene diisocyanate and trimethylolethane, and the like. it can. Here, the main structural components of the urethane resin may contain a chain extender, a crosslinking agent, and the like in addition to the polyol compound and the polyisocyanate compound. As the chain extender or crosslinking agent, ethylene glycol, propylene glycol, butanediol, diethylene glycol, ethylenediamine, diethylenetriamine, or the like can be used.

  Further, as the resin constituting the C layer in the present invention, those obtained by block copolymerization and graft copolymerization of acrylic resin and urethane resin can be used.

  As the acrylic / urethane copolymer resin constituting the C layer preferably used in the present invention, acrylic monomers include, for example, alkyl acrylate (the alkyl group is methyl, ethyl, n-propyl, n-butyl, isobutyl, t-butyl). , 2-ethylhexyl, cyclohexyl, etc.), 2-hydroxylethyl acrylate, 2-hydroxylethyl methacrylate, 2-hydroxypropyl acrylate, hydroxy group-containing monomers such as 2-hydroxypropyl methacrylate, acrylamide, methacrylamide, N-methylmethacrylamide, N-methylacrylamide, N-methylolacrylamide, N-methylolmethacrylamide, N, N-diethylaminoethyl acrylate, N, N-diethylaminoethyl methacrylate Amino group-containing monomers, glycidyl group-containing monomers such as glycidyl acrylate, glycidyl methacrylate, acrylic acid, methacrylic acid and their salts (sodium salts, potassium salts, ammonium salts, etc.) carboxyl groups or monomers containing such salts Can be used.

  Moreover, as the urethane component in the present invention, a resin obtained by reacting a polyhydroxy compound and a polyisocyanate compound by a known urethane resin polymerization method such as emulsion polymerization or suspension polymerization can be used. Examples of the polyhydroxy compound constituting the urethane component include polyethylene glycol, polypropylene glycol, polyethylene / polypropylene glycol, polytetramethylene glycol, hexamethylene glycol, tetramethylene glycol, 1,5-pentanediol, diethylene glycol, triethylene glycol, poly Caprolactone, polyhexamethylene adipate, polyhexamethylene sebacate, polytetramethylene adipate, polytetramethylene sebacate, trimethylolpropane, trimethylolethane, pentaerythritol, polycarbonate diol, glycerin and the like can be used.

  As the crosslinking agent constituting the C layer in the present invention, it is preferable to copolymerize a crosslinkable functional group. For example, melamine crosslinking agent, isocyanate crosslinking agent, aziridine crosslinking agent, epoxy crosslinking agent, methylolation or An alkylolized urea crosslinking agent, acrylamide crosslinking agent, polyamide crosslinking agent, oxazoline crosslinking agent, carbodiimide crosslinking agent, various silane coupling agents, various titanate coupling agents, and the like can be used. Further, from the viewpoint of heat-and-moisture resistance to the hard coat layer and the silicone-based adhesive layer, it is preferable to use two or more types of crosslinking agents. Specifically, at least one of the crosslinking agents is an oxazoline-based crosslinking agent or a carbodiimide. It is preferable to use a system crosslinking agent.

  Furthermore, since only the component of the C layer is easily charged, foreign matters may be mixed in various film processing steps, causing a problem of appearance defects. Therefore, it is preferable that the component of the coating layer contains a conductive polymer from the viewpoint of antistatic. As the conductive polymer, polypyrrole, polyaniline, polyacetylene, polythiophene vinylene, polyphenylene sulfide, poly-p-phenylene, polyheterocycle vinylene, particularly preferably (3,4-ethylenedioxythiophene) (PEDOT) is there.

  Moreover, as a particle added to the C layer, silica, colloidal silica, alumina, alumina sol, kaolin, talc, mica, calcium carbonate, or the like can be used.

  The decorative molded body obtained using the laminated film of the present invention comprises a resin-made base material, the laminated film of the present invention integrally laminated on the surface of the base material, and, if necessary, a colored layer. It is preferable. The material of the substrate is not particularly limited as long as it can be molded by various molding methods. For example, acrylic resin, polycarbonate resin, polybutylene terephthalate resin, acrylonitrile-butadiene styrene copolymer (ABS resin), acrylonitrile-styrene copolymer Examples include polymers (AS resins), FPR resins, polystyrene resins, polyether methylene resins, and polypropylene foam resins. The color tone and shape can be variously selected according to the purpose. A preferable resin is preferable because the surface hardness is improved by using a resin substrate having a high hardness such as an acrylic resin. As a method of integral molding of resin molding and laminated film, a sheet or film for decorative molding on which a pattern or the like is printed is used, and the sheet is integrated with the surface of the base material of the molded body by in-mold decorative molding. Although the method is widely performed, it is not particularly limited, and other methods such as injection molding, press molding, in-mold transfer molding method, thermoject method, CFI method and the like may be used.

  Next, although an example of the preferable manufacturing method of the laminated | multilayer film of this invention is demonstrated below, it is not restrict | limited by this.

  First, two types of resins A and B are prepared in the form of pellets. The pellets are dried in hot air or under vacuum as necessary, and then supplied to each of two extruders. In each extruder, the resin melted by heating to a temperature equal to or higher than the melting point makes the amount of resin extruded uniform with a gear pump or the like, and removes foreign matter or modified resin through a filter or the like. Resin A and resin B sent out from different flow paths using two extruders are sent into the multilayer laminating apparatus. As the multilayer laminating apparatus, a multi-manifold die, a feed block, a static mixer, or the like can be used. In particular, in order to efficiently obtain the configuration of the present invention, at least two members having a large number of fine slits are separately provided. It is preferable to use a feed block containing at least one. When such a feed block is used, the apparatus does not become extremely large, so that foreign matter due to thermal deterioration is small, and even when the number of layers is extremely large, it is possible to stack with high accuracy. Also, the stacking accuracy in the width direction is significantly improved as compared with the prior art. It is also possible to form an arbitrary layer thickness configuration. In this apparatus, since the thickness of each layer can be adjusted by the slit shape (length, width, gap), an arbitrary layer thickness can be achieved. For this reason, the layer structure which is the characteristic of this invention can be achieved easily. On the other hand, in the conventional apparatus, in order to achieve lamination of 250 layers or more, it is common to use a square mixer together. However, in such a method, the lamination flow is deformed and laminated in a similar system. In addition, it is difficult to achieve an arbitrary layer thickness.

  When the inclined structure has two or more steps, the change from the thin layer to the thick layer or the change in the layer thickness from the thick layer to the thin layer becomes very steep. In the present invention, a feed block including at least two members having a large number of fine slits is used. However, the layer thickness distribution changed immediately after merging at the location where the resins fed from the separate feed blocks merged, which was a major factor in varying the color tone in the width direction. Furthermore, since the resin velocity near the pipe decreases due to the influence of the wall surface of the pipe in the path from the feed block to the base, the color tone uniformity in the film width direction is further deteriorated due to the flow velocity difference between the pipe wall surface and the pipe center. . Therefore, the A layer and the B layer expressing a uniform color tone in the width direction without losing the lamination ratio by replacing a certain distance between the outermost layer portion of the film and the resin merging portion of separate feed blocks with the same polymer. A laminated film having an A / B laminated structure in which a total of 250 or more layers are alternately laminated in the thickness direction can be obtained. At this time, when the outermost layers on both sides in the A / B laminated structure are both composed of the A layer, the A layer corresponds to the thick film layer. Moreover, it is preferable that the resin used as the middle thick film layer is a highly crystalline resin in order to improve the trace resistance. In adjusting the thickness of the thick film layer, it is preferable to adjust each flow rate corresponding to the thickness of the corresponding layer by the gap between the slits. In this case, the gap accuracy of each slit gap is preferably ± 10 μm or less. By using such a special feed block, it is possible to obtain a laminated film that forms an inclined structure having two or more steps with high accuracy.

Next, in order to make the average reflectance in the wavelength section 380 nm to 500 nm of 25% or more and the average reflectance in the wavelength section 500 nm to 1200 nm less than 15%, which is a feature of the present invention, the layer thickness of each layer is set to It is necessary to design based on Equation 1 below. The laminated film in the present invention can reflect / transmit light, but the reflectance can be controlled by the difference in refractive index between the A layer and the B layer and the number of layers.
2 × (na · da + nb · db) = λ Equation 1
na: In-plane average refractive index of the A layer nb: In-plane average refractive index of the B layer da: Layer thickness (nm) of the A layer
db: Layer thickness of layer B (nm)
λ: main reflection wavelength (primary reflection wavelength)
The molten laminate formed in the desired layer configuration in this way is then formed into a desired shape by a die and then discharged. And the sheet | seat laminated | stacked in the multilayer discharged | emitted from die | dye is extruded on rotary cooling bodies, such as a casting drum, and is cooled and solidified, and a casting film (non-stretched film) is obtained. At this time, it is preferable to use a wire-like, tape-like, wire-like, or knife-like electrode to be brought into close contact with a rotating cooling body such as a casting drum by an electrostatic force and rapidly solidify. Also preferred is a method in which air is blown out from a slit-like, spot-like, or planar device to be brought into close contact with a rotating cooling body such as a casting drum and rapidly cooled and solidified, or brought into close contact with a rotating cooling body with a nip roll and rapidly cooled and solidified.

  The casting film (unstretched film) thus obtained is preferably biaxially stretched as necessary. Biaxial stretching refers to stretching in the longitudinal direction and the width direction. Stretching may be performed sequentially in biaxial directions or simultaneously in two directions. Further, it may be re-stretched in the longitudinal direction and / or the width direction. In particular, in the present invention, it is preferable to use simultaneous biaxial stretching from the viewpoint of suppressing in-plane orientation differences and from the viewpoint of suppressing surface scratches.

  First, the case of sequential biaxial stretching will be described. Here, the stretching in the longitudinal direction refers to stretching for imparting molecular orientation to the film in the longitudinal direction. Usually, the stretching is performed by a difference in the peripheral speed of the roll. You may carry out in multiple steps using a roll pair of books. The stretching ratio varies depending on the type of resin, but usually 2 to 15 times is preferable, and 2 to 7 times is particularly preferable when polyethylene terephthalate is used for any of the resins constituting the laminated film of the present invention. Used. Moreover, as extending | stretching temperature, the glass transition temperature-glass transition temperature +100 degreeC of resin which comprises a laminated | multilayer film are preferable.

  When a coating layer containing easy-slip particles (hereinafter referred to as C layer) is provided on the surface of the A / B laminated structure in the present invention, a method of coating and laminating a coating agent is preferable. As a method of coating the coating agent, a method in which coating is performed in a process separate from the production process of the laminated film of the present invention, a so-called off-line coating method, and a layer C by coating during the production process of the laminated film of the present invention There is a so-called in-line coating method in which layers are laminated at once. It is preferable to adopt an in-line coating method from the viewpoint of cost and uniform coating thickness, and the solvent of the coating liquid used in that case is preferably an aqueous system from the viewpoint of environmental pollution and explosion-proof property, and water is used. It is the most preferred embodiment to use.

  When laminating the C layer by in-line coating, a coating agent that constitutes the coating layer is continuously applied to the uniaxially stretched laminated film. As a coating method of a coating (water-based coating) using water as a solvent, for example, a reverse coating method, a spray coating method, a bar coating method, a gravure coating method, a rod coating method, a die coating method, or the like can be used.

  Moreover, it is preferable to perform a corona discharge treatment or the like on the surface of the A / B laminated structure before applying the aqueous coating agent. This is because the adhesiveness between the A / B laminated structure and the C layer is improved, and the coating property is also improved.

  Subsequent stretching in the width direction refers to stretching for imparting molecular orientation in the width direction of the film, usually using a tenter, transporting the film while holding both ends with clips, and applying heat to the film. After preheating, the film is stretched in the width direction. The aqueous coating applied just before the tenter is dried during this preheating. The stretching ratio varies depending on the type of resin, but usually 2 to 15 times is preferable, and 2 to 7 times is particularly preferable when polyethylene terephthalate is used for any of the resins constituting the laminated film of the present invention. . Moreover, as extending | stretching temperature, the glass transition temperature-glass transition temperature +120 degreeC of resin which comprises the laminated | multilayer film in this invention are preferable. The biaxially stretched laminated film is preferably subjected to a heat treatment not less than the stretching temperature and not more than the melting point in the tenter in order to impart flatness and dimensional stability. After being heat-treated in this way, it is gradually cooled gradually, cooled to room temperature, and wound up by a winder. Moreover, you may use a relaxation process etc. together in the case of annealing from heat processing as needed.

  After being heat-treated in this way, it is gradually cooled gradually, cooled to room temperature, and wound up by a winder.

  Next, the case of simultaneous biaxial stretching will be described. In the case of simultaneous biaxial stretching, the coating agent which comprises C layer is apply | coated continuously to the obtained cast film. As a coating method of a coating (water-based coating) using water as a solvent, for example, a reverse coating method, a spray coating method, a bar coating method, a gravure coating method, a rod coating method, a die coating method, or the like can be used.

  Moreover, it is preferable to perform a corona discharge treatment or the like on the surface of the A / B laminated structure before applying the aqueous coating material. This is because the adhesiveness between the A / B laminated structure and the C layer is improved, and the coating property is also improved. Next, the cast film (non-stretched film) coated with the coating agent is guided to the simultaneous biaxial tenter, and conveyed while holding both ends of the film with clips, and stretched in the longitudinal and width directions simultaneously and / or stepwise. To do. As simultaneous biaxial stretching machines, there are pantograph method, screw method, drive motor method, linear motor method, but it is possible to change the stretching ratio arbitrarily and drive motor method that can perform relaxation treatment at any place or A linear motor system is preferred. The stretching magnification varies depending on the type of resin, but usually, the area magnification is preferably 6 to 50 times, and the area magnification is particularly preferably 8 to 30 times. In particular, in the case of simultaneous biaxial stretching, it is preferable to make the stretching ratios in the longitudinal direction and the width direction the same and to make the stretching speeds substantially equal in order to suppress the in-plane orientation difference. Moreover, as extending | stretching temperature, the glass transition temperature-glass transition temperature +120 degreeC of resin which comprises a laminated | multilayer film are preferable.

  The biaxially stretched film is preferably subsequently subjected to a heat treatment not less than the stretching temperature and not more than the melting point in the tenter in order to impart flatness and dimensional stability. In this heat treatment, in order to suppress the distribution of the main orientation axis in the width direction, it is preferable to perform relaxation treatment in the longitudinal direction instantaneously immediately before and / or immediately after entering the heat treatment zone. After being heat-treated in this way, it is gradually cooled gradually, cooled to room temperature, and wound up by a winder. Moreover, you may perform a relaxation | loosening process in a longitudinal direction and / or the width direction at the time of annealing from heat processing as needed. It is preferable to perform relaxation treatment in the longitudinal direction immediately before and / or immediately after entering the heat treatment zone.

  After being heat-treated in this way, it is gradually cooled gradually, cooled to room temperature, and wound up by a winder.

  Since the laminated film of the present invention has excellent winding properties and transparency, it can be suitably used as a screen protective film and a decorative molded body obtained using the laminated film.

  EXAMPLES Hereinafter, although this invention is demonstrated along an Example, this invention is not restrict | limited by these Examples. Various characteristics were measured by the following methods.

(1) Layer constitution and layer thickness of film A sample about 1 cm square was cut out from a total of five points of ± 500 mm and ± 1000 mm in the film width direction position with respect to the central part of the laminated film and the central part. About each sample, the cross section was cut out using a microtome, and the cross section of the film was magnified 40,000 times at an acceleration voltage of 75 kV using a transmission electron microscope (Hitachi Ltd., H-7100FA type). Then, the cross-sectional portion was photographed to measure the layer configuration and the layer thickness. Moreover, the total thickness of each layer was made into the laminated film whole thickness. In order to obtain a high contrast, the sample was stained with RuO ₄ .

  A specific method for obtaining the layer structure and layer thickness of the film will be described. About 40,000 times TEM photographs were captured with CanonScan D123U (manufactured by Canon Inc.) at an image size of 729 dpi. The image was saved in JPEG format, and then the JPEG file was opened and image analysis was performed using image processing software (sales company Planetron Co., Ltd., Imagc-Pro Plus ver. 4). In the image analysis processing, in the vertical thick profile mode, the relationship between the average brightness in the region sandwiched between the two lines in the thickness direction and the width direction was read as numerical data. Using spreadsheet software (Excel2000), the data of position (nm) and brightness were sampled at sampling step 6 (decimation 6) and subjected to numerical processing of 3-point moving average. Furthermore, the data obtained by periodically changing the brightness is differentiated, and the maximum and minimum values of the differential curve are read by a VBA (Visual Basic For Applications) program. Calculated as the layer thickness. This operation was performed for each photograph, and the layer thicknesses of all layers were calculated.

(2) Measurement of coating layer thickness and particle diameter Using a microtome, a small piece cut in a direction perpendicular to the surface of the laminated film was prepared, and the cross section was taken as a field emission scanning electron microscope JSM-6700F (JEOL Ltd. ))) And magnified to 10,000 times. From the cross-sectional photograph, the thickness of the coating layer and the particle size distribution of the particles present in the coating layer were determined using image analysis software Image-Pro Plus (Nippon Roper). The cross-sectional photograph is selected from different measurement fields, the diameter of 2500 or more particles arbitrarily selected from the cross-sectional photograph is measured, and the volume-based particle size distribution is plotted with the horizontal axis representing the particle diameter and the vertical axis representing the abundance ratio of the particles. Got. In the volume-based particle size distribution, the particle size responsible for the horizontal axis is based on the class for each 20 nm interval starting from 0 nm, and the abundance ratio of the particles responsible for the vertical axis is calculated by the formula “existence ratio = corresponding particle size. It is expressed by “total volume of detected particles / total volume of all detected particles”. From the chart of the abundance ratio of the particles obtained as described above, the particle diameter of the peak top showing the maximum was obtained.

(3) Young's modulus A sample was cut from the center in the width direction of the film at 15 cm in the longitudinal direction and 1.5 cm in the width direction, and used as a sample for measuring Young's modulus in the longitudinal direction. Similarly, a sample for measuring Young's modulus in the width direction was cut out at 15 cm in the width direction and 1.5 cm in the longitudinal direction. Elastic modulus, breaking strength, breaking elongation were measured with a tensile tester (Tensilon UTM-III manufactured by Toyo Sokki Co., Ltd.) with a test length of 10 cm, pulled at a speed of 20 cm / min, and recorded stress-strain curves. And determined by the method of JISK7113.

(4) In a haze normal state (temperature 23 ° C., relative humidity 65%), the laminated polyester film was allowed to stand for 1 hour, and then measured using a turbidimeter “NDH5000” manufactured by Nippon Denshoku Industries Co., Ltd. The average value obtained was taken as the haze of the laminated film.

(5) Average reflectance A 5 cm square sample was cut out from the center of the laminated film. Subsequently, the relative reflectance in incident angle (PHI) = 10 degree | times was measured using the spectrophotometer (The Hitachi, Ltd. make, U-4100 Spectrophotometer). The inner wall of the attached integrating sphere is barium sulfate, and the standard plate is aluminum oxide. The measurement wavelength was 250 nm to 1200 nm, the slit was 2 nm (visible) / automatic control (infrared), the gain was set to 2, and the measurement was performed at a scanning speed of 600 nm / min. The back of the sample was painted black with oil-based ink. Subsequently, the average reflectance in wavelength band 300-500 nm and 500 nm-1200 nm was calculated. The average reflectance is calculated by calculating the area surrounded by the reflection curve and the wavelength band based on the Simpson method formula using the absolute reflectance data for each wavelength of 1 nm, and dividing by the wavelength band width of 300 nm. Thus, the average reflectance was obtained. A detailed explanation of the Simpson method is described in “Numerical calculation method I for electronic computers” (Baifukan) (1965) by Jiro Yamauchi et al.

(6) Air drop index Using a Digibeck smoothness tester manufactured by Toyo Seiki Co., Ltd., set the coating layer surface of the film on the sample stage in accordance with the air inlet. At this time, the center of the film is set to the center of the sample stage. In this state, a weight of 200 g is placed on the top of the film, the vacuum level is set to 383 mmHg with the vacuum pump, the vacuum pump is stopped, and the time (seconds) for the vacuum level to decrease from 380 mmHg to 379 mmHg is defined as the air loss index. .

(7) Rolling form of film roll The film was slit and wound on a roll having a width of 1,100 mm and a length of 2,000 m under conditions of a tension of 280 N / m, a surface pressure of 280 N / m, and a speed of 160 m / min. Sometimes, it is determined by the amount of deviation between the roll surface and the end face described below.
◎: Less than 1 mm ○: 1 mm or more and less than 3 mm Δ: 3 mm or more and less than 10 mm x: 10 mm or more (8) Film roll winding hardness In the TAPIO RQP, roll the film roll in the roll width direction. The hardness was measured and the hardness was determined at a pitch of 5 mm in the width direction, and the average hardness was calculated from the obtained width direction hardness distribution.

(9) The surface of the coating film layer of the particle detachable laminated film was reciprocated 100 times with a load of 500 g / cm 2, a speed of 60 mm / sec, and a reciprocating distance of 120 mm using Toray Co., Ltd. A Gakushin friction fastness tester (“AB-301” manufactured by Tester Sangyo Co., Ltd.) was used as the wear test device. The powder on the surface of the trethy after the test was visually observed and judged according to the following criteria.
◎: No powder on Toraysee ○: Powder is found in places of Toraysee ×: Powder is seen on the Toraysee (10) Blocking resistance In two films, the coating layer is applied to one side of the film In this case, the surface of the coating layer is overlapped with the surface where the coating layer is not applied, and when the coating layer is applied on both sides of the film, the coating layer surface is overlapped and a pressure of 1.5 kg / cm 2 is applied to this. After peeling for 65 hours in an atmosphere of 80 ° C. × 80%, peeling is performed, and the peeling force is evaluated (g number per 5 cm). In addition, evaluation is performed on the following reference | standard from peeling force.
◎: Less than 2 g ○: 2 g or more to less than 5 g x: 5 g or more to tearing (11) Surface specific resistance value on the surface of the C layer After leaving the substrate film for screen protection at 23 ° C. and 65% relative humidity for 24 hours Using a digital ultra-high resistance / microammeter (manufactured by Advantest Co., Ltd., R8340A), the surface specific resistance value after application for 10 seconds at an applied voltage of 100 V was determined. The measurement surface is the coating surface side of the coating layer.

(12) Antistatic property (11) From the measurement results of the surface specific resistance value, the following criteria were used for evaluation.
○: Less than 1.0 × 10 ¹⁴ Ω / □ ×: 1.0 × 10 ¹⁴ Ω / □ or more.

(13) Touch panel operability When a capacitive touch panel display to which a screen protection film using the laminated film was attached was operated with a finger, the evaluation was performed according to the following criteria.
○: The touch panel operates well. Δ: The operation is dull and there are places where it does not work. X: The touch panel does not work at all.

(material)
(Resin A)
To a mixture of 100 parts by weight of dimethyl terephthalate and 60 parts by weight of ethylene glycol, 0.09 parts by weight of magnesium acetate and 0.03 parts by weight of antimony trioxide are added with respect to the amount of dimethyl terephthalate, and the temperature is raised by a conventional method. Then, a transesterification reaction is performed. Subsequently, 0.020 part by weight of 85% aqueous solution of phosphoric acid is added to the transesterification reaction product with respect to the amount of dimethyl terephthalate, and then transferred to a polycondensation reaction tank. Furthermore, the reaction system was gradually depressurized while being heated and heated, and a polycondensation reaction was carried out by a conventional method at 290 ° C. under a reduced pressure of 1 mmHg. Polyethylene terephthalate (hereinafter referred to as PET) having an intrinsic viscosity (IV) of 0.63. Got).

(Resin B-1)
Polyethylene terephthalate copolymerized with 21 mol% of spiroglycol (SPG) having an intrinsic viscosity (IV) of 0.55 and 24 mol% of cyclohexanedicarboxylic acid (CHDC).

(Resin B-2)
Polyethylene terephthalate copolymerized with 30 mol% of cyclohexanedimethanol (CHDM) having an intrinsic viscosity (IV) of 0.72.

(Resin B-3)
Copolymer polyethylene terephthalate obtained by mixing Resin A and Resin B-1 at 75:25.

(Resin B-4)
Copolymer polyethylene terephthalate obtained by mixing Resin A and Resin B-2 at 18:82.

(Resin B-5)
Copolyethylene terephthalate obtained by mixing Resin A and Resin B-2 at 38:62.
(Resin B-6)
Copolyethylene terephthalate obtained by mixing Resin A and Resin B-2 at 59:41.
(Composition of coating layer (C layer))
(Coating layer C-1)
-Aqueous dispersion of acrylic / urethane copolymer resin (a): Sannaron WG658 (solid content concentration 30% by weight), manufactured by Sannan Synthetic Chemical Co., Ltd.
-Aqueous dispersion of isocyanate compound (b): Elastron E-37 (solid content concentration: 28% by weight) manufactured by Daiichi Kogyo Seiyaku Co., Ltd.
-Aqueous dispersion of epoxy compound (c): manufactured by DIC Corporation, CR-5L (solid content concentration: 100% by weight)
-An aqueous dispersion of the composition (d) comprising a compound having a polythiophene structure and a compound having an anion structure (solid content concentration 1.3% by weight)
-Aqueous dispersion of oxazoline compound (e): Nippon Shokubai Co., Ltd., Epocross WS-500 (solid content concentration 40% by weight)
-Aqueous dispersion of carbodiimide compound (f): Nisshinbo Co., Ltd., Carbodilite V-04 (solid content concentration 40%)
(Easy-slip particles contained in the coating layer (C-1))
Silica particles W (g (i)): JGC Catalysts & Chemicals, Spherica slurry 140 (solid content concentration 40%)
Silica particle X (g (ii)): Nippon Shokubai Co., Ltd., Seahoster KE-W30 (solid content concentration 20%)
Silica particle Y (g (iii)): JGC Catalysts & Chemicals, Cataloid SI-80P (solid content concentration 40%)
Silica particles Z (g (iv)): Nippon Shokubai Co., Ltd., Seahoster KE-W50 (solid content concentration 20%)
-Acetylene diol-based surfactant (h): manufactured by Nissin Chemical Co., Ltd., Olfine EXP4051 (solid content concentration 50%)
-Aqueous solvent (i): pure water The above-mentioned (a) to (h) in terms of solids weight ratio (a) / (b) / (c) / (d) / (e) / (f) / ( g (i)) to (g (iv)), and the total addition amount in any combination of the plurality / (h) = 100/100/75/25/60/60/10/15 In addition, (i) was mixed and the concentration was adjusted so that the solid content concentration of the aqueous coating agent ((a) to (f), (h)) was 3% by weight.

(Coating layer C-2)
-Aqueous dispersion of acrylic / urethane copolymer resin (a): Sannaron WG658 (solid content concentration 30% by weight), manufactured by Sannan Synthetic Chemical Co., Ltd.
-Aqueous dispersion of isocyanate compound (b): Elastron E-37 (solid content concentration: 28% by weight) manufactured by Daiichi Kogyo Seiyaku Co., Ltd.
-Aqueous dispersion of epoxy compound (c): manufactured by DIC Corporation, CR-5L (solid content concentration: 100% by weight)
-An aqueous dispersion of the composition (d) comprising a compound having a polythiophene structure and a compound having an anion structure (solid content concentration 1.3% by weight)
-Aqueous dispersion of oxazoline compound (e): Nippon Shokubai Co., Ltd., Epocross WS-500 (solid content concentration 40% by weight)
-Aqueous dispersion of carbodiimide compound (f): Nisshinbo Co., Ltd., Carbodilite V-04 (solid content concentration 40%)
(Sliding particles contained in the coating layer C-2)
Silica particles W (g (i)): JGC Catalysts & Chemicals, Spherica slurry 140 (solid content concentration 40%)
Silica particle X (g (ii)): Nippon Shokubai Co., Ltd., Seahoster KE-W30 (solid content concentration 20%)
Silica particle Y (g (iii)): JGC Catalysts & Chemicals, Cataloid SI-80P (solid content concentration 40%)
Silica particles Z (g (iv)): Nippon Shokubai Co., Ltd., Seahoster KE-W50 (solid content concentration 20%)
-Acetylene diol-based surfactant (h): manufactured by Nissin Chemical Co., Ltd., Olfine EXP4051 (solid content concentration 50%)
-Aqueous solvent (i): pure water The above-mentioned (a) to (h) in terms of solids weight ratio (a) / (b) / (c) / (d) / (e) / (f) / ( g (i)) to (g (iv)), and the total addition amount in any combination of the plurality / (h) = 100/100/30/10/60/60/10/15 In addition, (i) was mixed and the concentration was adjusted so that the solid content concentration of the aqueous coating agent ((a) to (f), (h)) was 3% by weight.
(Coating layer C-3)
-Aqueous dispersion of acrylic / urethane copolymer resin (a): Sannaron WG658 (solid content concentration 30% by weight), manufactured by Sannan Synthetic Chemical Co., Ltd.
-Aqueous dispersion of isocyanate compound (b): Elastron E-37 (solid content concentration: 28% by weight) manufactured by Daiichi Kogyo Seiyaku Co., Ltd.
-Aqueous dispersion of epoxy compound (c): manufactured by DIC Corporation, CR-5L (solid content concentration: 100% by weight)
-An aqueous dispersion of the composition (d) comprising a compound having a polythiophene structure and a compound having an anion structure (solid content concentration 1.3% by weight)
-Aqueous dispersion of oxazoline compound (e): Nippon Shokubai Co., Ltd., Epocross WS-500 (solid content concentration 40% by weight)
-Aqueous dispersion of carbodiimide compound (f): Nisshinbo Co., Ltd., Carbodilite V-04 (solid content concentration 40%)
(Sliding particles contained in the coating layer C-3)
Silica particles W (g (i)): JGC Catalysts & Chemicals, Spherica slurry 140 (solid content concentration 40%)
Silica particle X (g (ii)): Nippon Shokubai Co., Ltd., Seahoster KE-W30 (solid content concentration 20%)
Silica particle Y (g (iii)): JGC Catalysts & Chemicals, Cataloid SI-80P (solid content concentration 40%)
Silica particles Z (g (iv)): Nippon Shokubai Co., Ltd., Seahoster KE-W50 (solid content concentration 20%)
-Acetylene diol-based surfactant (h): manufactured by Nissin Chemical Co., Ltd., Olfine EXP4051 (solid content concentration 50%)
-Aqueous solvent (i): pure water The above-mentioned (a) to (h) in terms of solids weight ratio (a) / (b) / (c) / (d) / (e) / (f) / ( g (i)) to (g (iv)), and the total addition amount in any combination of the plurality / (h) = 100/100/110/40/60/60/10/15 In addition, (i) was mixed and the concentration was adjusted so that the solid content concentration of the aqueous coating agent ((a) to (f), (h)) was 3% by weight.
(Coating layer C-4)
-Aqueous dispersion of acrylic / urethane copolymer resin (a): Sannaron WG658 (solid content concentration 30% by weight), manufactured by Sannan Synthetic Chemical Co., Ltd.
-Aqueous dispersion of isocyanate compound (b): Elastron E-37 (solid content concentration: 28% by weight) manufactured by Daiichi Kogyo Seiyaku Co., Ltd.
-Aqueous dispersion of oxazoline compound (e): Nippon Shokubai Co., Ltd., Epocross WS-500 (solid content concentration 40% by weight)
-Aqueous dispersion of carbodiimide compound (f): Nisshinbo Co., Ltd., Carbodilite V-04 (solid content concentration 40%)
(Sliding particles contained in the coating layer C-4)
Silica particles W (g (i)): JGC Catalysts & Chemicals, Spherica slurry 140 (solid content concentration 40%)
Silica particle X (g (ii)): Nippon Shokubai Co., Ltd., Seahoster KE-W30 (solid content concentration 20%)
Silica particle Y (g (iii)): JGC Catalysts & Chemicals, Cataloid SI-80P (solid content concentration 40%)
Silica particles Z (g (iv)): Nippon Shokubai Co., Ltd., Seahoster KE-W50 (solid content concentration 20%)
-Acetylene diol-based surfactant (h): manufactured by Nissin Chemical Co., Ltd., Olfine EXP4051 (solid content concentration 50%)
-Aqueous solvent (i): pure water The above-mentioned (a) to (h) are expressed as a solid content weight ratio in terms of (a) / (b) / (e) / (f) / (g (i)) to (g (iv)) and a total addition amount in any one of a plurality of combinations / (h) = 100/100/60/60/10/15, and the aqueous coating agent (( (i) was mixed and the concentration was adjusted so that the solid concentration of a), (b), (e), (f), and (h)) was 3% by weight.

Example 1
A resin A and a resin B-3 were each melted at 280 ° C. by a separate twin screw extruder with a vent, and then a slit having a second manifold having a length twice the slit width through a gear pump and a filter. Were joined by a 903-layer feed block having three slit plates having 301 pieces. The outermost layers on both sides to be the thick film layer are resin A, and the resin A and the resin B-3 are alternately laminated, and the layers made of the adjacent resin A and the resin B-3 in the thin film layer. The thickness was made almost the same. And the layer thickness of the layer which consists of adjacent resin A-1 and the layer which consists of resin B-1 was made to become substantially the same. Next, after being led to a T-die and formed into a sheet, it was brought into close contact with a casting drum maintained at a surface temperature of 25 ° C. by applying electrostatic force, and rapidly solidified to obtain a cast film.

  The obtained cast film was heated with a roll group set at 75 ° C., then stretched 3.3 times in the longitudinal direction while rapidly heating from both sides of the stretch section with a radiation heater between 100 mm in length, and then cooled once. Thus, a uniaxially stretched film was obtained. Next, the both sides of the uniaxially stretched film were subjected to corona discharge treatment in the air, the coating tension of the film was set to 55 mN / m, and the added particles were particles W and X with a # 4 metabar. 1 composition was applied to one side of the film.

  The obtained uniaxially stretched film was guided to a tenter, and after preheating with 100 ° C hot air, it was stretched 3.6 times in the transverse direction at a temperature of 110 ° C. The stretched film is directly heat-treated in a tenter with hot air of 230 ° C., then subjected to a relaxation treatment of 7% in the width direction at the same temperature, and then cooled to room temperature and wound with a winder. An axially stretched film was obtained. The total film thickness of the obtained biaxially stretched laminated film was 41 μm. The layer design of this laminated film is as shown in FIG. 1, and the layer thickness of each layer was controlled by adjusting the slit gap. A cross section in the thickness direction of the laminated film was observed with a TEM, and a layer thickness distribution was determined by image processing. 1 is a thick film layer indicated by 3 in FIG. 1, and the layer numbers 1 and 903, which are the outermost layers composed of the resin A, are both 0.4 μm in thickness and are composed of the resin A. The layer thickness of 301 and layer number 601 was 0.1 μm. Moreover, the layer thickness distribution (4 and 5 in FIG. 1) in the inclined structure of the A layer and the B layer formed by the thin film layers was 10 nm to 100 nm, respectively. The properties and evaluation results of this laminated film are shown in Table 1.

(Example 2)
A laminated film having a thickness of 41 μm was obtained in the same manner as in Example 1 except that the resin B-3 in Example 1 was changed to the resin B-4. The properties and evaluation results of this laminated film are shown in Table 1.

(Example 3)
A laminated film having a thickness of 45 μm was prepared in the same manner as in Example 1 except that the thicknesses of Layer No. 1 and Layer No. 903, which were the outermost layers of Example 2, were adjusted to 2.5 μm by adjusting the corresponding slit width. Obtained. The properties and evaluation results of this laminated film are shown in Table 1.

Example 4
A laminated film having a thickness of 41 μm was obtained in the same manner as in Example 2 except that only the particles W were added to the composition of the coating layer of Example 2. The properties and evaluation results of this laminated film are shown in Table 1.

(Example 5)
A laminated film having a thickness of 41 μm was obtained in the same manner as in Example 1 except that the resin B-3 in Example 1 was changed to the resin B-5. The properties and evaluation results of this laminated film are shown in Table 1.

(Example 6)
Lamination with a thickness of 34 μm in the same manner as in Example 5 except that in the manufacturing process of Example 5, two types of resin were merged using a 549-layer feed block having two slit plates having 275 slit plates. A film was obtained. The layer thicknesses of Layer No. 1 and Layer No. 549, which are the outermost layers composed of Resin A, were both 1.0 μm. The properties and evaluation results of this laminated film are shown in Table 1.

(Example 7)
A laminated film having a thickness of 40 μm was prepared in the same manner as in Example 6 except that the layer thicknesses of Layer No. 1 and Layer No. 549, which were the outermost layers of Example 6, were adjusted to 4.0 μm by adjusting the corresponding slit widths. Obtained. The properties and evaluation results of this laminated film are shown in Table 1.

(Example 8)
A laminated film having a thickness of 100 μm was prepared in the same manner as in Example 6 except that the layer thicknesses of Layer No. 1 and Layer No. 549, which were the outermost layers of Example 6, were adjusted to 29.5 μm by adjusting the corresponding slit width. Obtained. The properties and evaluation results of this laminated film are shown in Table 1.

Example 9
A laminated film having a thickness of 41 μm was obtained in the same manner as in Example 6 except that Resin B-5 in Example 6 was changed to Resin B-6. The properties and evaluation results of this laminated film are shown in Table 1.

(Example 10)
A laminated film having a thickness of 41 μm was obtained in the same manner as in Example 1 except that the composition of the coating film layer C-1 of Example 1 was changed to the composition of the coating film layer C-2. The properties and evaluation results of this laminated film are shown in Table 1.

(Example 11)
A laminated film having a thickness of 41 μm was obtained in the same manner as in Example 1 except that the composition of the coating layer C-1 of Example 1 was changed to the composition of the coating layer C-3. The properties and evaluation results of this laminated film are shown in Table 1.

(Example 12)
A laminated film having a thickness of 41 μm was obtained in the same manner as in Example 1 except that the composition of the coating layer C-1 of Example 1 was changed to the composition of the coating layer C-4. The properties and evaluation results of this laminated film are shown in Table 1.

(Example 13)
As a protective film of the laminated film obtained in the same manner as in Example 7, a hard coat layer having a thickness of 3 μm was formed. The coating method is as follows. The coating agent shown below is prepared, uniformly applied to the film with a # 10 bar coater, dried with a hot air convection dryer at 100 ° C. for 1 minute to remove the solvent, then 80 W / cm, Ultraviolet irradiation was performed under the condition of a conveyance speed of 20 m / min. The light transmittance of the hard coat layer alone is 91%.
UA-122P (Shin Nakamura Chemical) Urethane acrylate 70 parts DPHA (Nippon Kayaku) Dipentaerythritol hexaacrylate 8 parts U-15HA (Shin Nakamura Chemical) Urethane acrylate 8 parts Irgacure 184 (Ciba Specialty Chemicals) Photoinitiator 5 Part SH190 (silicone oil, manufactured by Toray Dow Corning Silicone Co., Ltd., trade name) 5 parts MEK 110 parts Next, on the opposite surface of the laminated film, 98% by mass of butyl acrylate, 1.5% by mass of acrylic acid, 0.5% of hydroxyethyl acrylate To 100 parts by mass of an acrylic ester copolymer (weight average molecular weight: 800,000, concentration: 40% by mass) obtained by copolymerizing 5% by mass, a tackifier [Product name “Pine Crystal, manufactured by Arakawa Chemical Industries, Ltd.” KE-359 "] 30 parts by weight, toluene and trill A coating agent for an adhesive layer, which was added with 0.5 parts by mass of a diisocyanate-based trifunctional adduct [manufactured by Nippon Polyurethane Co., Ltd., product name “Coronate L” concentration: 75% by mass], was dried using a die coater. Apply a coating agent for the adhesive layer / adhesive layer so that the film thickness is 4.5 μm, and dry it at 120 ° C. for 1 minute, then paste it with a polyethylene terephthalate film [product name “Therapy WZ” manufactured by Toray Industries, Inc. Thus, when the protective film obtained was bonded to an LED display, it was excellent in transparency and low saturation without impairing the visibility of the display. The light could be cut.

(Example 14)
On the surface of the laminated film obtained in the same manner as in Example 1, a binder IMB-003 manufactured by Teikoku Ink Manufacturing Co., Ltd. was formed with a thickness of 3 μm. Then, after pre-molding by press molding and trimming into a mobile phone shape, insert molding was performed under the following molding conditions. At this time, the film end face was joined to the step portion of the resin. The obtained decorative molded body was excellent in appearance, with no appearance defects such as color unevenness and flow marks observed.

Mold temperature: 80 ℃
Molding resin temperature: 260 ° C
Molding resin: SD polycarbonate (IM6011)
Clamping pressure: 60ton
Molded housing: PC (Comparative Example 1)
In the production process of Example 2, a laminated film having a thickness of 41 μm was obtained in the same manner as in Example 2 except that the coating layer was coated with a # 2 metabar. The properties and evaluation results of this laminated film are shown in Table 1.

(Comparative Example 2)
A laminated film having a thickness of 41 μm was obtained in the same manner as in Example 2 except that the particles added to the composition of the coating layer of Example 2 were particles X and Y. The properties and evaluation results of this laminated film are shown in Table 1.

(Comparative Example 3)
A laminated film having a thickness of 41 μm was obtained in the same manner as in Example 2 except that the particles to be added to the composition of the coating film layer of Example 2 were particles Z and W. The properties and evaluation results of this laminated film are shown in Table 1.

(Comparative Example 4)
A laminated film having a thickness of 41 μm was obtained in the same manner as in Example 2 except that no particles were added to the composition of the coating layer of Example 2. The properties and evaluation results of this laminated film are shown in Table 1.

(Comparative Example 5)
In the production process of Example 1, a laminated film having a thickness of 100 μm was obtained by adjusting the casting drum speed. The layer thickness distribution (4 and 5 in FIG. 1) in the gradient structure of the A layer and the B layer formed by the thin film layer of this film was 10 nm to 220 nm, respectively. The properties and evaluation results of this laminated film are shown in Table 1.

(Comparative Example 6)
A laminated film having a thickness of 100 μm was obtained in the same manner as in Comparative Example 4 except that Resin B-3 in Comparative Example 5 was changed to Resin B-6. The properties and evaluation results of this laminated film are shown in Table 1.

(Comparative Example 7)
In the manufacturing process of Example 9, a laminated film having a thickness of 100 μm was obtained by adjusting the casting drum speed. The properties and evaluation results of this laminated film are shown in Table 1.

(Comparative Example 8)
In the manufacturing process of Example 9, a laminated film having a thickness of 34 μm was obtained in the same manner as in Example 9 except that the coating layer was coated with a # 8 metabar. The properties and evaluation results of this laminated film are shown in Table 1.

(Comparative Example 9)
In the production process of Example 1, a single-layer film having a thickness of 40 μm was obtained in the same manner as in Example 1 except that the feed block was not used and a single-layer film of only resin A was used. The properties and evaluation results of this single layer film are shown in Table 1.

  According to the present invention, it is possible to obtain a laminated film having excellent winding properties and transparency that can obtain a film roll having a good winding shape when being wound in a roll shape while suppressing haze. More specifically, as a screen protection film for LED displays obtained by using it, and a decorative molded body such as a blue decorative design, for example, screen protection films for mobile phones, smartphones, personal computers, televisions, etc., It can be suitably used for a decorative member such as a housing or home appliance.

1: Layer number 2: Layer thickness 3: Thick film layer 4: Layer thickness distribution of layer A 5: Layer thickness distribution of layer B

Claims (7)

It has a structure (hereinafter referred to as an A / B multilayer structure) in which layers of resin A (hereinafter referred to as A layer) and layers of resin B (hereinafter referred to as B layer) are alternately laminated in the thickness direction by 250 layers or more. A laminated film having a coating layer (hereinafter referred to as C layer) containing easy-slip particles on at least one surface and satisfying all of the following (1) to (3).
(1) The average reflectance in the wavelength section from 380 nm to 500 nm is 25% or more, and the average reflectance in the wavelength section from 500 nm to 1200 nm is less than 15%.
(2) The film haze is less than 1%.
(3) The air escape index on the surface of the C layer is 200 s or more and less than 1500 s.   In the C layer composed of at least one resin selected from an acrylic resin and a urethane resin and having a coating layer thickness of 40 nm or more and less than 90 nm, the volume-based particle size distribution measurement of the easy-slip particles is performed, and the horizontal axis represents the particles When the diameter and the vertical axis are plotted as the abundance ratio of particles, the obtained chart of the abundance ratio of easy-to-slip particles has two maxima, and one peak top of the maxima has a particle diameter of 250 nm to less than 350 nm The laminated film according to claim 1, wherein the other peak top is in the range of 100 nm or more and less than 200 nm.   3. The laminate according to claim 1, wherein the outermost layers on both sides of the A / B laminate structure are both A layers, and the thickness of each outermost layer is 1% or more and less than 40% with respect to the total film thickness. the film. The laminated film according to claim 1, wherein the surface specific resistance of the surface of the C layer is 1 × 10 ¹¹ Ω / □ or more and less than 1 × 10 ¹⁴ Ω / □.   The resin A is mainly composed of polyethylene terephthalate or polyethylene naphthalate, and the resin B is a polyester comprising at least one of spiroglycol, cyclohexanedicarboxylic acid, and cyclohexanedimethanol. 4. The laminated film according to any one of 4 above.   The screen protection film obtained using the laminated | multilayer film in any one of Claims 1-5. A decorative molded body obtained by using the laminated film according to any one of claims 1 to 5.

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