WO2016148141A1

WO2016148141A1 - Layered film, liquid crystal display using same, touch panel, and organic el display

Info

Publication number: WO2016148141A1
Application number: PCT/JP2016/058157
Authority: WO
Inventors: 合田亘; 高橋弘造; 松尾雄二
Original assignee: 東レ株式会社
Priority date: 2015-03-17
Filing date: 2016-03-15
Publication date: 2016-09-22
Also published as: KR102534378B1; TW201641274A; JP6809222B2; KR20170126460A; CN107407755B; JPWO2016148141A1; TWI696555B; CN107407755A

Abstract

The drawbacks of bleedout and/or film breakage and yellowing occur in film formation when an absorbent such as a UV absorber or a dye is added at a high concentration during melt extrusion in the kneading and addition of the absorbent to conventional single-layer films and multi-layer films, and a thin film having high ability to shield light in the UV-to-blue wavelength region is difficult to obtain. The prior art also has the drawback that a synergism with the absorbent in shielding properties in the UV-to-blue wavelength region is not obtained even when the reflecting ability of a multilayer structure is jointly used. The present invention is a layered film in which at least 50 layers including layers (A layers) comprising a thermoplastic resin A and layers (B layers) comprising a thermoplastic resin B are layered in alternating fashion, wherein at least either the A layers or the B layers include one or both of a dye and a UV absorbent for absorbing blue light, the product of the film thickness and the concentration of the dye, UV absorbent, or both for absorbing blue light is 0.35 or less, and, in the wavelength range of 300 nm to 500 nm, the maximum reflectance is 15% or greater and the minimum transmittance is 70% or less.

Description

Laminated film, liquid crystal display using the same, touch panel and organic EL display

The present invention relates to a laminated film that efficiently cuts ultraviolet light and blue light, a liquid crystal display using the same, a touch panel, and an organic EL display.

Conventionally, there is a demand for films that cut ultraviolet rays in the fields of automobiles, building materials, and electronics. The purpose of cutting off the ultraviolet rays is to prevent adverse effects on the human body and deterioration of the members due to ultraviolet rays from sunlight. In the field of automobiles and building materials, it is used as a window film by laminating and laminating laminated glass or single plate glass to play a role in suppressing human skin and indoor member deterioration. In the electronics field, protective films for suppressing the curing of photosensitive resins and polarizer protective films added with ultraviolet (UV) absorbers for the purpose of protecting the liquid crystal layer of liquid crystal display panels from deterioration due to external light are known. It has been. In recent years, since the light source of liquid crystal displays has become a strong blue light LED, there is a risk that the blue light will adversely affect the retina of the human eye and the circadism of the human body. ing.

Conventionally, these light blocking methods have been generally used by adding organic or inorganic ultraviolet or yellow light absorbers inside the film, or by coding on the film. However, the light absorption characteristics of conventional ultraviolet (hereinafter referred to as “UV”) and blue light absorbers tend to be more yellowish in the color transmitted through the film, and are avoided in terms of design (design) and color design. There was a problem.

In particular, when a UV absorber is kneaded into a resin, it has high sublimation properties due to insufficient heat resistance, and film formation by melt extrusion has a problem of film breakage due to bleeding out or thermal decomposition of the UV absorber. Therefore, it is necessary to reduce the addition amount of the UV absorber, and measures have been taken to compensate for the UV shielding performance by increasing the film thickness. Here, bleed out means that the sublimation product has high sublimation properties, and a low molecular weight additive having a low melting point is extruded together with a high molecular weight resin (polymer) at a high temperature. Phenomenon that affects the quality and physical properties that lead to defects and defects of products due to pyrolysis products.

On the other hand, in the case of coating, the UV curing type using a crosslinking agent has a problem in that when a UV absorber is added, a curing reaction due to crosslinking is difficult to occur, and the matrix resin that should be cured does not solidify. When the coating layer is made thin, it is necessary to add a high concentration of UV absorber, and there is a problem that the tendency to not solidify becomes stronger.

Recently, smartphones and tablets have become thinner and more precise, and the amount of UV absorber added to films has reached a critical concentration despite an increasing trend, which is an urgent issue to be solved. .

Therefore, an ultraviolet cut film has been proposed by alternately laminating different transparent resin layers at the optical wavelength level without using a UV absorber and using a light interference reflection phenomenon (Patent Document 1). However, the optical interference reflection phenomenon has a problem that the interference reflection wavelength shifts depending on the incident angle of light, and has no shielding property against light entering from all directions, and cannot completely protect or prevent deterioration of the human body and members. Had a problem. In addition, the resin itself has a problem of deterioration.

On the other hand, a light-stable product including a single-layer or multi-layer polyester film in which a UV absorber and a light stabilizer are used together has been proposed for the purpose of preventing resin deterioration even after long-term exposure to ultraviolet rays outdoors (Patent Document 2). This is an invention of a combination of a light stabilizer and a UV absorber, which is not a multi-layer structure or a UV shielding property relating to a UV absorber, but merely for extending the life of resin degradation. Moreover, it is an example of UV absorber addition to the single layer film by the conventional melt extrusion process, and the bleeding out problem of UV absorber has arisen.

Recently, a UV shielding film using a UV absorber and UV interference reflection has been proposed. (Patent Document 3) This is a UV absorber added at a high concentration to an optical layer or a non-optical protective layer provided on the film surface in order to prevent deterioration of the UV reflective multilayer optical film itself. The function is to separate reflection and absorption mainly by the film structure.

JP 7-507152 A (second page) Special Table 2003-532752 (paragraph 2) Special table 2013-511746 gazette (2nd page)

As described above, in the kneading addition of absorbers such as UV absorbers and pigments to conventional single layer films and multilayer films, when adding a high concentration of absorbent during melt extrusion, bleeding out in film formation, There are problems of film breakage and yellowishness, and it has been difficult to produce a thin film having a high light shielding performance in the wavelength range of UV to blue. And even if it is going to use the reflection performance by a multilayer structure like patent document 3, since the addition thickness of UV absorber in the whole film is as much as 2 weight% or more, the effect of interference reflection is large. There wasn't. Moreover, examination was insufficient about the UV absorber. Therefore, not only the UV absorber bleeds out from the outermost protective layer, but also the UV absorption performance is dominant, so there is a big problem that the UV reflection performance does not work effectively. That is, there is a problem that the synergistic effect of the shielding property in the wavelength band of UV to blue region between the UV absorber and the reflection performance by the multilayer structure does not occur.

In order to solve this problem, the present invention has the following configuration. That is, a laminated film in which layers of thermoplastic resin A (A layer) and layers of thermoplastic resin B (B layer) are alternately laminated at least 50 layers, and at least one of layer A or layer B The layer of the film contains a dye that absorbs blue light and / or UV absorber, or both, and the product of the film thickness and the concentration of dye or UV absorber that absorbs blue light or both is 0.35 [μm · % / 100] or less, and a maximum reflectance of 15% or more and a minimum transmittance of 70% or less at a wavelength of 300 nm to 500 nm.

In particular, from the viewpoint of suppressing bleed out, a dye or UV absorber having a molecular weight exceeding 500 is added only to the B layer, and the lamination ratio is 1 or less, and the dye or UV absorbing blue light from the viewpoint of shielding properties. The long wavelength absorption edge of the absorber is preferably larger than the long wavelength edge of the reflection band due to interference reflection based on the layered structure of the layers.

The present invention combines the reflectivity based on interference reflection and the absorptivity by an absorbent, and creates a synergistic effect of both, thereby sharply shielding light with a wavelength of 460 nm or less or with a wavelength of 380 nm or less, and blocking blue light. Achieving low concentration of absorbing dye or UV absorber. In particular, it solves bleed-out and film breakage, which are problems in film formation of UV shielding films containing pigments and UV absorbers that absorb blue light, and has high UV and blue light even when the thickness is thin. A laminated film maintaining the shielding property can be provided. The shielding here includes the concept of reflection and absorption, and the scale is expressed by transmittance.

Moreover, it is suitable for various protective film applications such as window films, blue light cut films, and process films for dry film photoresists by eliminating the viewing angle dependence peculiar to interference reflection due to the multilayer structure. In particular, by controlling the phase difference, it is possible to provide a laminated film suitable for use in a polarizer protective film or a circularly polarizing film for liquid crystal displays.

(A) Composition diagram of a laminated film having a layer to which a blue light absorbing dye or UV absorber, or both are added, (b) a single film to which a blue light absorbing dye or UV absorber, or both are added Diagram of layer film It is explanatory drawing explaining an example of the manufacturing method of the laminated film used for this invention, (a) is a schematic front view of an apparatus, (b), (c), (d) is LL ', MM, respectively. It is sectional drawing of the resin flow path cut | disconnected by ', NN'. (A) Example of layer thickness distribution of laminated film having three inclined structures, (b) Example of layer thickness distribution of laminated film having two inclined structures (A) Explanatory view of absorption increase in laminated film having three reflection walls (b) Explanatory view of absorption increase in laminated film having two reflective walls Example of screen protection film affixed to a cover glass on an electronic device such as a liquid crystal display (A) An example of a polarizing plate using a laminated film, (b) A schematic diagram of an LCD panel having a structure in which a liquid crystal cell is sandwiched between polarizing plates, (c) From a main alignment axis of the laminated film and a polarizer of an upper polarizing plate A diagram showing the angle between the linear polarization axis (A) Configuration example of touch panel using laminated film as polarizer protective film (b) Touch panel configuration example when using laminated film as scattering prevention film and circularly polarizing plate. (C) Touch panel configuration example when the laminated film is used as a GF1 type ITO base material as a film sensor. The figure which showed the relationship between the long wavelength absorption edge of a pigment | dye or a UV absorber, and the long wavelength edge of the reflective band of a laminated film Explanatory drawing of spectral transmission spectrum and spectral reflection spectrum of laminated film containing dye Spectral transmission spectrum and spectral reflection spectrum of laminated film containing UV absorber

The present invention will be described below. The laminated film of the present invention is a laminated film obtained by alternately laminating at least 50 layers of layers composed of a thermoplastic resin A (A layer) and layers composed of a thermoplastic resin B (B layer). The product of the film thickness and the concentration of the dye or UV absorber that absorbs blue light, or both is included in at least one of the layers B, which contains a dye or UV absorber that absorbs blue light, or both. It is 0.35 [μm · weight% / 100] or less, and it is necessary that the maximum reflectance is 15% or more and the minimum transmittance is 70% or less at a wavelength of 300 to 500 nm.

Examples of the thermoplastic resin used in the laminated film of the present invention include chain polyolefins such as polyethylene, polypropylene, poly (4-methylpentene-1) and polyacetal, ring-opening metathesis polymerization of norbornenes, addition polymerization, and other olefins. Biodegradable polymers such as alicyclic polyolefin, polylactic acid, and polybutyl succinate, polyamides such as nylon 6, nylon 11, nylon 12, and nylon 66, aramid, polymethyl methacrylate, polychlorinated Vinyl, polyvinylidene chloride, polyvinyl alcohol, polyvinyl butyral, ethylene vinyl acetate copolymer, polyacetal, polyglycolic acid, polystyrene, styrene acrylonitrile copolymer, styrene copolymer polymethyl methacrylate, polycar -Polyesters such as polypropylene, polyethylene terephthalate, polyethylene terephthalate, polybutylene terephthalate, polyethylene-2,6-naphthalate, polyethersulfone, polyetheretherketone, modified polyphenylene ether, polyphenylene sulfide, polyetherimide, polyimide, polyarylate, 4 Fluorinated ethylene resin, trifluoroethylene resin, trifluorochloroethylene resin, tetrafluoroethylene-6-fluoropropylene copolymer, polyvinylidene fluoride, polycondensate of ethylene terephthalate and parahydroxybenzoic acid, phenol and Basic composition of parahydroxybenzoic acid, such as polycondensate of phthalic acid and parahydroxybenzoic acid, polycondensate of 2,6-hydroxynaphthoic acid and parahydroxybenzoic acid, etc. And then while it is possible to use a liquid crystal polymer various component and an aromatic polyester resin obtained by ester bonding to linear. Among them, it is particularly preferable to use polyester from the viewpoint of good extrusion molding, excellent chemical resistance, strength, heat resistance and transparency, and versatility. These may be a homopolymer, a copolymer, or a mixture of a plurality of polymers.

The polyester is preferably a polyester obtained by polymerization from an aromatic dicarboxylic acid or aliphatic dicarboxylic acid and a diol or an ester-forming derivative thereof. 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′-diphenyl Examples thereof include dicarboxylic acid, 4,4'-diphenyl ether dicarboxylic acid, 4,4'-diphenylsulfone dicarboxylic acid, 6,6 '-(ethylenedioxy) di-2-naphthoic 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 these, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, and cyclohexanedicarboxylic acid that exhibit high refractive index and rigidity are preferable. These acid components may be used alone or in combination of two or more thereof, and further may be partially copolymerized with oxyacids such as hydroxybenzoic acid.

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-cyclohexanedimethanol, diethylene glycol, triethylene glycol, polyalkylene glycol, 2,2-bis (4- Hydroxyethoxyphenyl) propane, 9,9-bis [4- (2-hydroxyethoxy) phenyl] fluorene, isosorbate, spiroglycol, hydrogenated bisphenol A, bisphenol A / propylene oxide, bisphenol A / ethylene oxide, glycerin, trimethylol Propane, trimethylol ether Emissions, ethylene oxide, propylene oxide and the like. Of these, fluorene, ethylene glycol, 1,4-cyclohexanedimethanol, spiroglycol, isosorbade, and bisphenol A ethylene oxide are preferably used from the viewpoint of a high glass transition point and low birefringence. In particular, these diol components may be used alone or in combination of two or more.

Among the above polyesters, either one is realized from the viewpoint of realizing high reflectivity in the blue to UV wavelength region, good thermal dimensional stability, high productivity, and excellent solubility in UV absorbers and pigments. The thermoplastic resin A is preferably polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polybutylene naphthalate, or polyhexamethylene terephthalate from the viewpoint that orientation crystallization can be imparted by biaxial stretching and heat treatment. From the viewpoint of crystallinity, it is preferable to use these copolymers having a copolymerization component of 15 mol% or less. Dicarboxylic acids for copolymerization are terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, cyclohexanedicarboxylic acid, and diols are fluorene, ethylene glycol, 1,4-cyclohexanedimethanol, spiroglycol, isosorbade, and bisphenol A ethylene oxide. Preferably, a quaternary copolymer obtained by combining these may be used. These may be a single copolymer copolymer, or a polymer alloy of a homopolymer and the copolymer.

On the other hand, as the thermoplastic resin B, it is preferable to use a copolymer of the polyester resin having 5 to 60 mol% of the copolymer component. Thus, when the copolymerization rate is high, it is likely to become amorphous, and the UV absorber and the dye tend to stay in the amorphous region. Moreover, since the heat treatment melts in the layer and the refractive index becomes isotropic, the in-plane refractive index difference between the A layer and the B layer increases, and the refractive index difference is also increased with respect to the viewing angle. Therefore, the reflectance can be improved. More preferably, the copolymerization component is 15 mol% or more and 50 mol% or less. In a preferred embodiment of the present invention, when the copolymerization rate of the thermoplastic resin B is high, the in-plane refractive index of the B layer is lower than that of the A layer. Refraction of light according to the law occurs at the interface between the A layer and the B layer. At that time, the optical path length in the B layer is longer than that in the A layer. That is, in the laminated film of the present invention, since the B layer is present, the effect of the dye that absorbs blue light and the UV absorber with respect to the viewing angle that is obliquely incident light is composed of only the thermoplastic resin A. Compared to a single layer film, the optical path length is increased, and the absorption performance is improved according to the Lambert-Beer law. Furthermore, in the present invention, since light absorption and interference reflection occur simultaneously, absorption resonance occurs, and a synergistic effect of blue light wavelength and UV shielding occurs.

The laminated film of the present invention needs to be a laminated film obtained by alternately laminating at least 50 layers of layers made of thermoplastic resin A (A layer) and layers made of thermoplastic resin B (B layer). This is because if it is less than 50 layers, the reflectivity due to interference reflection is small, and a synergistic effect of the shielding performance of blue light and ultraviolet rays hardly occurs. More preferably, it is 150 layers or more, More preferably, it is 250 layers or more. If the number of layers is too large, the entire thickness of the film becomes thick, so 600 layers or less are preferable. More preferably, it is 300 layers or less.

The laminated film of the present invention comprises a layer (A layer) composed of a thermoplastic resin A containing a dye that absorbs blue light, a UV absorber, or both in at least one of the A layer and the B layer. It is a laminated film in which at least 50 or more layers made of plastic resin B (B layer) are alternately laminated, and the product of the film thickness and the concentration of the dye or UV absorber that absorbs blue light, or both is contained. It must be 0.35 or less.

Here, the dye absorbing blue light means a dye having absorption characteristics in a wavelength range of 400 to 500 nm centered around 450 nm which is the wavelength of blue light. The pigments here can be classified into pigments (organic / inorganic) and dyes. The laminated film of the present invention is preferably a pigment exhibiting yellow, orange or even blue color from the viewpoint of reflecting in the wavelength region of 300 nm to 500 nm and effectively shielding blue light. The pigments can be roughly classified into inorganic pigments, organic pigments, and classical pigments. As the yellow inorganic pigment, chrome yellow, zinc yellow, cadmium yellow, titanium yellow, barium yellow, cobalt yellow, ocher, and fillit yellow are preferable. As the blue inorganic pigment, ultramarine blue and bitumen are preferable. A pigment is preferable in terms of moisture and heat resistance, and an organic pigment is particularly preferable from the viewpoint of affinity with a thermoplastic resin. Organic pigments are roughly classified into azo pigments, phthalocyanine pigments, dyed lakes, heterocyclic pigments, and the like.

Azo pigments are classified into insoluble azo pigments, azo lake pigments, condensed azo pigments, and metal complex azo pigments. Further, insoluble azo pigments are classified into β-naphthol-based, naphthol-AS-based, acetoacetate arylamide-based insoluble monoazo pigments, acetoacetate arylamide-based, and pyrazolone-based insoluble disazo pigments. Azo lake pigments are classified into β-naphthol type and β-oxynaphthoic acid type.

The phthalocyanine pigment is classified into copper phthalocyanine, halogenated copper phthalocyanine, metal-free phthalocyanine, and copper phthalocyanine lake.

The heterocyclic pigments are classified into anthoraquinone pigments, thioindigo pigments, perinone pigments, perylene pigments, quinacridone pigments, dioxazine pigments, isoindolinone pigments, quinophthalone pigments, and isoindoline pigments. From the viewpoint of shielding light steeply with respect to the wavelength, anthoraquinone pigments and isoindoline pigments are preferred.

Other examples include nitrone pigments, alizarin lakes, metal complex azomethine pigments, aniline black, alkali blue, and natural organic pigments. Among organic pigments, yellow is preferably anthraquinone, auramin lake, quinophthalone, or monoazobenzenesulfonate-based pigment, and blue is preferably a copper phthalocyanine pigment from the viewpoint of heat resistance and difficulty in bleeding out.

The UV absorber of the present invention is preferably a benzophenone-type, benzotriazole-type, triazine-type, or benzoxazine-type known as typical UV absorbers that absorb ultraviolet rays and convert them into thermal energy. Examples of the benzophenone series include 4-methoxy-2-hydroxybenzophenone: molecular weight 228, 4-methoxy-2-hydroxybenzophenone-5-sulfonic acid: molecular weight 308, 2,4-dihydroxybenzophenone: molecular weight 214, 4,4 ' -Dimethoxy 2,2'-dihydroxybenzophenone: molecular weight 274, 4,4'-dimethoxy-2,2'-dihydroxy-5,5'-disulfonic acid benzophenone disodium: molecular weight 478, 2,2'-4,4 ' -Tetrahydroxybenzophenone: molecular weight 246, sodium hydroxymethoxybenzophenone sulfonate: molecular weight 376, octabenzone: molecular weight 326, 2-hydroxy-4-m-octoxy-benzophenone: molecular weight 345, 2-hydroxy-4-n-octoxybenzophenone: And a molecular weight of 326, bis (5-benzoyl-4-hydroxy-2-methoxyphenyl) methane: molecular weight of 468, and the like.

As the benzotriazole series, 2- (2H-benzotriazol-2-yl) -p-cresol: molecular weight 225, 2- (2H-benzotriazol-2-yl) -4-6-bis (1-methyl) -1-phenylethyl) phenol: molecular weight 448, 2- [5-chloro (2H) -benzotriazol-2-yl] -4-methyl-6- (tert-butyl) phenol: molecular weight 316, 2,4-di -tert-Butyl-6- (5-chloro-2H-1,2,3-benzotriazol-2-yl) phenol: molecular weight 358, 2- (2H-benzotriazol-2-yl) -4,6-tert -Pentylphenol: molecular weight 352, 2- (2H-benzotriazol-2-yl) -4- (1,1,3,3-tetramethylbutyl) phenol: molecular weight 323, 2,2'-methylenebis [6- ( 2H-benzotriazol-2-yl) -4- (1,1,3,3-tetramethylbutyl) phenol]: molecular weight 659, 2 (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) ) 5 Chlorobenzotriazole: molecular weight 315, 2 (2'-hydroxy-3'5- Di-tert-butyl-phenyl) 5-chlorobenzotriazole: molecular weight 357, 2 (2'-hydroxy-5'-methylphenyl) benzotriazole: molecular weight 225, 2- (2-hydroxy-5-octylphenyl) -benzotriazo- Lu: molecular weight 323 and the like.

Further, triazines include 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5-[(hexyl) oxy] -phenol: molecular weight 426, 2- [4,6- Bis (2,4-dimethylphenyl) -1,3,5-triazin-2-yl] -5- (octyloxy) phenol:

molecular weight

509, 2,4,6-tris (2-hydroxy-4- Hexyloxy-3-methylphenyl) -1,3,5-triazine: molecular weight 700, 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5- [2- (2- Ethylhexanoyloxy) ethoxy] phenol: molecular weight 512, 1,6-hexanediamine, N, N′-bis (1,2,2,6,6-pentamethyl-4-piperidyl), polymers morpholine-2,4, Examples include, but are not limited to, 6-trichloro-1,3,5-triazine.

As the benzoxazine series, 2,2 ′-(1,4-phenylene) bis (4H-3,1-benzoxazine-4-one): molecular weight 368 can be mentioned. In addition, tetra-ethyl-2,2- (1,4-phenylene-dimethylidene-bismalonic acid with malonic ester structure: molecular weight 418, 2-ethyl 2,2'-ethoxy-oxamide with oxalic anilide structure: molecular weight 312, etc. The above-mentioned components can be used in combination of two or more.

The laminated film of the present invention preferably contains a triazine skeleton or a benzotriazole skeleton having a UV absorber molecular weight of 500 or more. This is because when the molecular weight is 500 or more, the amount of sublimation is small when melt-extruded, and there is little influence on the contamination of the polymer and film production lines and the quality of the film. Moreover, it is preferable that a functional group has polar groups, such as a hydroxyl group, from a compatible viewpoint with polyester.

The combined use of the dye for absorbing blue light of the present invention and a UV absorber is preferable from the viewpoint of functional separation and wide blocking of the wavelength of light. It is preferable to use two or more types having different absorption peaks. The combination to be used in combination is preferable because the absorption peak wavelength is different by 30 nm or more, thereby efficiently shielding light of different wavelengths. Further, the UV absorber having a higher molecular weight and lower melting point suppresses the other bleed-out from the viewpoint of the trapping effect that prevents the UV absorber having a higher melting point and higher crystallinity from appearing on the surface. The low melting point side is preferably 160 ° C. or lower, while the high melting point side is preferably 190 ° C. or higher. For example, 2,4,6-tris (2-hydroxy-4-hexyloxy-3-methylphenyl) -1,3,5-triazine having an absorption peak at a wavelength of 350 nm or more and 2 having an absorption peak at a wavelength of 320 nm or less. -(4,6- (4-biphenyl) -1,3,5-triazin-2-yl) -5- (2-ethylhexyloxy) -phenol in combination with the former suppresses the latter bleed-out This is preferable.

It is necessary that the product of the film thickness of the laminated film of the present invention and the contained concentration of the dye or UV absorber that absorbs blue light, or both is 0.35 [μm · weight% / 100] or less. The product of the film thickness and the dye or UV absorber that absorbs blue light, or the concentration of both, represents the absolute amount of the dye or UV absorber in the laminated film. It was found that this value is an important parameter affecting bleed-out as well as the type of dye and UV absorber. More preferably, it is 0.25 [μm · weight% / 100] or less, and further preferably 0.15 [μm · weight% / 100] or less. If it exceeds 0.35 [μm · weight% / 100], bleeding out tends to occur, and a synergistic effect of absorption efficiency due to interference reflection becomes difficult to develop.

From the viewpoint of thinning, the film thickness is preferably 50 to 3 μm. More preferably, it is 35 to 5 μm. More preferably, it is 20 to 6 μm. If the thickness is too thin, the number of layers required for interference reflection of the wavelength of UV to blue light cannot be secured. Moreover, it is because handling becomes difficult. On the other hand, if it is too thick, the absolute value of the added amount of the dye or UV absorber that absorbs blue light becomes large at the same concentration, so that it becomes easy to bleed out and it becomes difficult to reduce the thickness of the laminated film. Sometimes.

Further, the concentration of the absorbent as the whole film is preferably 0.1% by weight or more and 3% by weight or less. Since UV absorbers and organic dyes generally have a low melting point, they bleed out during melt extrusion. The higher the concentration, the easier it is to bleed out, so the lowest possible concentration is preferred. Preferably, they are 0.1 weight% or more and 2.0 weight% or less. More preferably, it is 0.1 wt% or more and 1.5 wt%. More preferably, they are 0.1 weight% or more and 1.0 weight% or less. Most preferably, it is 0.1 wt% or more and 0.6 wt% or less. Moreover, the pigment | dye or UV absorber which absorbs blue light, or both may be contained only in A layer, only B layer, and both A layer and B layer. In particular, when a polyester resin copolymer is mainly used for the B layer, since many amorphous regions exist, the UV absorber tends to stay in the B layer. Further, the B layer is vulnerable to ultraviolet rays as compared to the A layer that undergoes orientation crystallization. Therefore, from the viewpoint of ultraviolet deterioration and bleed out, it is preferable that the B layer contains a large amount. The absorbent concentration ratio between the A layer and the B layer is preferably A: B = 1: 4 to 2: 3.

The laminated film of the present invention needs to have a maximum reflectance of 15% or more and a minimum transmittance of 70% or less at a wavelength of 300 nm to 500 nm. If the reflectance is not more than 15% at a certain wavelength, there is little synergistic effect between interference reflection and the dye or the absorbent, and the contribution of the absorbent is dominant. On the other hand, when 90% or more is reflected, reflection of less than 70% is preferable, and reflection of less than 50% is more preferable from the viewpoint that almost no contribution of the dye or UV absorber is present. More preferably, the reflection is 40% or less. When the contribution of the synergistic effect is large, the reflection is efficiently replaced by the absorption, so that the reflectance is lowered, but at the same time, the absorption effect is strong. In particular, in the case of a UV shielding film, the maximum reflectance at a wavelength of 400 nm to 500 nm is preferably 15% or less from the viewpoint of being colorless and highly transparent. If there is a reflection peak exceeding a reflectance of 15% at a wavelength of 400 nm or more, the color of the laminated film when viewed with transmitted light is strong in yellow, and the appearance of purple to blue is strong in reflected light. In particular, this leads to a decrease in total light transmittance and in-plane color unevenness. The reflection wavelength of the reflection peak having a reflectance exceeding 15% is preferably 400 nm or less, or 390 nm or less, more preferably 380 nm or less, and further preferably 360 nm or less. Most preferably, it is 330 nm or less. An example of spectral reflection and spectral transmission spectrum patterns representing these aspects is shown in FIG.

FIG. 1 shows an example of a structure in which a laminated film according to the present invention and a conventional single layer film are added with a dye or a UV absorber that absorbs blue light, or both. The present invention will be described in detail with reference to FIG. In the laminated film 5 of the present invention, 50 layers or more of layers (A layer) 1 made of thermoplastic resin A and layers (B layer) 2 made of thermoplastic resin B are alternately laminated. As shown in FIG. 1A, when the laminated film 5 is irradiated with incident light 3 having a wavelength in the blue to UV range, a part of the light is reflected at the interface because there is a difference in refractive index between different resin layers. It becomes light 4. In FIG. 1A, a dye or UV absorber that absorbs blue light, or both 6 are included in a layer (B layer) 2 made of a thermoplastic resin B, and absorption occurs in this layer. That is, the present invention is a physical phenomenon in which reflection and absorption occur simultaneously in a region other than surface reflection. On the other hand, the conventional single-layer film shown in FIG. 1B only absorbs light except for surface reflection with respect to incident light 3 having a wavelength in the blue to UV range. This absorption phenomenon is generally known to follow Lambert's law expressed by the following formula (1).
I = IoExp (−kx) (1)
(However, Io: incident light intensity, I: outgoing light intensity, k: absorption coefficient, x: distance through which light passes (optical path length))
The laminated film 5 of the present invention is surprisingly different from the single layer film governed by the characteristics of the light absorber, and surprisingly the formula (1) does not hold. It has been found that the laminated film can greatly reduce the concentration of the light absorber because interference reflection is added compared to the amount of the light absorber added to the single layer film. That is, the minimum transmittance of incident light is 70% at a wavelength of 300 to 500 nm even when the product of the film thickness and the concentration of the dye or UV absorber that absorbs blue light, or both is 0.35 or less. It is as follows. From the viewpoint of shielding properties, it is more preferably 50% or less. The shielding property here can be measured with the minimum transmittance in the spectral transmittance spectrum. That is, a minimum transmittance of 50% at a wavelength of 300 to 500 nm means that 50% of incident light is shielded. In the laminated film of the present invention, when a UV absorber is added, the transmittance at a wavelength of 370 nm is preferably 5% or less. If it exceeds 5%, the UV shielding becomes insufficient, so when used as a polarizer protective film for a polarizing plate, the PVA or liquid crystal layer that is a polarizer cannot be protected during the production process. More preferably, it is 4% or less, and more preferably 3% or less. In particular, the transmittance is most preferably 2% or less over the entire wavelength range of 370 nm to 300 nm.

The laminated structure of the laminated film of the present invention can be easily realized by the same method as described in the paragraphs [0053] to [0063] of JP-A-2007-307893. However, the gap and length of the slit plate are different because of design values that determine the layer thickness. Below, the process of making a laminated film is demonstrated with reference to FIG.

The laminating apparatus 7 shown in FIG. 2 has the same three slit plates as the apparatus described in Japanese Patent Application Laid-Open No. 2007-307893. An example of the layer thickness distribution of the laminated structure obtained by the laminating apparatus 7 is shown in FIG. When the horizontal axis indicates the layer arrangement order 18 and the vertical axis indicates the average layer thickness (nm) 19 of each layer, the laminated structure has a layer thickness gradient structure 11 and a slit plate 72 by a resin laminate flow formed by the slit plate 71. The three inclined structures are the layered gradient structure 12 formed by the laminated flow of the resin and the layered inclined structure 13 formed by the laminated resin flow formed by the slit plate 73. Further, as shown in FIG. 3A, it is preferable that one inclined structure is opposite in direction to any other inclined structure. In addition, the inclined structure formed by one slit plate has a layer thickness distribution in which the resin A and the resin B are alternately laminated, and an average layer thickness distribution 21 of the layer made of the adjacent resin A and the layer made of the resin B. expressed. The lamination ratio can be easily adjusted by the ratio of the extrusion amounts of the resin A and the resin B of the two extruders.

The number of layers and the thickness of the laminated film are adjusted so that the average layer thickness is in the range of 40 nm to 80 nm in order to strongly reflect light in the UV to blue wavelength region. To form a film. The average layer thickness is the average layer thickness of the layer pair of the adjacent A layer and B layer. This operation is sequentially performed on all the layers of the laminated film, and the layer thickness distribution obtained for the layer pair number is defined as the average layer thickness distribution. When the layer thickness distribution of resin A (dA ₁ , dA ₂ ... DA _N ) and the layer thickness distribution of resin B (dB ₁ , dB ₂ ... DB _N ) are expressed, the average layer thickness distribution 21 is , {(DA ₁ + dB ₁ ) / 2, (dA ₂ + dB ₂ ) / 2,... (DA _N + dB _N ) / 2)}, respectively. N represents a layer number or a layer pair number, which is the order of layers. Since there are one pair of layer pairs, that is, the A layer and the B layer, about half of the number of layers is generally the total number of layer pairs. d represents the layer thickness, and the alphabet represents the resin layer.

FIG. 3 shows the average layer thickness distribution of the laminated film of the present invention. The laminated film of the present invention interferes and reflects light having a wavelength less than that of blue light. Therefore, the maximum average layer thickness of the average layer thickness means an average layer thickness that reflects 500 nm or less when converted to a reflection wavelength using the formula (5). The maximum average layer thickness in the polymer structure of the present invention is preferably 80 nm or less. Moreover, when interference-reflecting UV light having a wavelength of 400 nm or less, it is preferably 60 nm. From the viewpoint of requiring colorless and transparent in the UV shielding film, an average layer thickness of 58 nm or less at which the wavelength at the long wavelength end of the reflection band is 380 nm or less is more preferable.

As shown in FIG. 2B, the resin flow having a laminated structure that flows out from each slit plate constituting the laminating apparatus 7 flows out from the

outlets

11L, 12L, and 13L of the laminating apparatus, and then the merger 8 Then, rearrangement is performed in the cross-sectional shapes of 11M, 12M, and 13M shown in FIG. When the slit plate has a single structure, there is no rearrangement. Next, the length in the film width direction of the cross section of the flow path is widened inside the connecting pipe 9 and flows into the base 10, and further widened by the manifold and extruded from the lip of the base 10 into a sheet in a molten state. Then, it is cooled and solidified on the casting drum to obtain an unstretched film. Subsequently, it can also obtain by the method of extending | stretching at the temperature more than the glass transition point temperature (Tg) of resin which comprises the unstretched film obtained as needed.

The stretching method at this time is preferably biaxially stretched by a known sequential biaxial stretching method or simultaneous biaxial stretching method from the viewpoint of realizing high reflectance, thermal dimensional stability, and large area. The known biaxial stretching method may be a method of stretching in the width direction after stretching in the longitudinal direction, a method of stretching in the longitudinal direction after stretching in the width direction, and a plurality of stretching in the longitudinal direction and stretching in the width direction. You may carry out in combination. For example, in the case of a stretched film composed of polyester, the stretching temperature and the stretching ratio can be appropriately selected. In the case of a normal polyester film, the stretching temperature is 80 ° C. or more and 150 ° C. or less, and the stretching ratio is 2 times. It is preferably 7 times or more. The stretching method in the longitudinal direction is performed using a change in the peripheral speed between the rolls. Moreover, the well-known tenter method is utilized for the extending | stretching method of the width direction. In the simultaneous biaxial stretching method, the film is conveyed while being gripped at both ends by a simultaneous biaxial tenter and stretched simultaneously and / or stepwise in the longitudinal direction and the width direction. Stretching in the longitudinal direction is achieved by increasing the distance between the clips of the tenter and in the width direction by increasing the distance between the rails on which the clips run.

The tenter clip subjected to stretching and heat treatment in the present invention is preferably driven by a linear motor system. In addition, there are a pantograph method, a screw method, etc. Among them, the linear motor method is excellent in that the stretching ratio can be freely changed because the degree of freedom of each clip is high.

The retardation of the laminated film of the present invention is preferably 1 nm or more and 400 nm or less from the viewpoint of suppressing rainbow unevenness. In order to make it 1 nm or more and 400 nm or less, it is necessary to equalize the orientation state of the polymer chains in the vertical and horizontal directions. From the viewpoint of reducing the retardation and thickness unevenness of the laminated film of the present invention, the longitudinal stretching temperature is 95 ° C. or more and 105 ° C. or less, the longitudinal stretching ratio is 3 to 3.6 times, and the transverse stretching temperature is 100 ° C. or more and 140 ° C. or less. A combination of draw ratios of the transverse draw ratio of 3.4 to 4.6 times is preferable. When polyethylene naphthalate and its copolymer are mainly used as the thermoplastic resin A, the longitudinal stretching temperature is 130 ° C. or higher and 160 ° C. or lower, and the lateral stretching temperature is 140 ° C. or higher and 160 ° C. from the viewpoint of high glass transition point. The following is preferred. In addition, in polarizer protection applications, if the phase difference is high, brightness and color spots appear on the display. More preferably, they are 150 nm or less and 1 nm or more, More preferably, they are 100 nm or less and 1 nm or more.

On the other hand, it is preferable that the phase difference of the laminated film of the present invention is 4000 nm or more and 20000 nm or less as an opposite measure for obtaining a similar effect. In order to obtain a high phase difference of 4000 nm or more and 20000 nm or less, a combination of uniaxial stretching of 4 times or more in the longitudinal or lateral direction, or a combination of stretching ratios of 2.8 times or less and 4.5 times or more in width is preferable. Preferably, the uniaxial stretching is 5 times or more. The stretched film is then heat treated in a tenter. This heat treatment is generally performed at a temperature higher than the stretching temperature and lower than the melting point. When polyester is used, it is preferably carried out in the range of 200 ° C to 250 ° C. Further, it is preferable to perform a relaxation heat treatment of about 2 to 10% in the width direction or the longitudinal direction in order to impart thermal dimensional stability of the film.

The laminated film of the present invention has a layer (A) comprising a thermoplastic resin A that reflects at least part of light in the wavelength range, wherein the absorption peak wavelength of a dye or UV absorber that absorbs blue light is 300 nm to 500 nm. Layer) and a layer made of thermoplastic resin B (layer B), the average value of the layer thickness of a pair of layers is 40 nm to 80 nm, and the layer pair becomes a reflection wall for blue light and UV light. It is preferable that at least two reflection walls exist at different positions in the film thickness direction. The absorption peak wavelength indicates a maximum value of the extinction coefficient, and is preferably a wavelength that indicates the maximum value of the extinction coefficient.

The maximum value of the extinction coefficient of the preferred UV absorber is shown below. Bis (5-benzoyl-4-hydroxy-2-methoxyphenyl) methane, 2,2'-methylenebis [6- (2H-benzotriazol-2-yl) -4- (1,1,3,3-tetramethyl Butyl) phenol], 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5- [2- (2-ethylhexanoyloxy) ethoxy] phenol, 2,4,6- These such as tris (2-hydroxy-4-hexyloxy-3-methylphenyl) -1,3,5-triazine are preferable as UV absorbers because they have a maximum absorption at a wavelength of 340 to 360 nm. On the other hand, an anthraquinone-based, isoindolinone-based, quinophthalone-based, or monoazobenzenesulfonate-based organic pigment is preferable because it has a maximum absorption at a wavelength of 380 to 500 nm. You may use combining these.

Average layer thickness of a pair of layers composed of a layer (A layer) made of thermoplastic resin A that reflects at least part of light having a wavelength of 300 nm to 500 nm and a layer (B layer) made of thermoplastic resin B It will be described in detail that the value is 40 nm to 80 nm and the layer pair becomes a reflection wall of blue light or UV light. When the light incident angle θ is in the range of 0 to 60 degrees, the following formulas (3) and (4) are satisfied, and the following formula (5) is satisfied particularly when the incident light is perpendicular to the laminated film. To do. In the present invention, when the reflection wavelength λ based on the following formula (5) is 300 to 500 nm, at least one or more layer pairs of dA and dB satisfying the formula (5) exist in the layer thickness distribution of the laminated film. It means to do. Since the equation (5) is satisfied, this layer pair becomes a reflection wall of blue light or UV light, and it means that the average layer thickness is in the range of 80 nm to 40 nm. This can be calculated and confirmed from the layer thicknesses of the A layer and the B layer which can be measured by cross-sectional TEM observation. From the viewpoint of reflection, it is preferably the presence of a layer pair having an average layer thickness of 80 nm to 40 nm of 10 sets or more, more preferably 30 sets or more. Expressions (3) to (5) are expressions of the reflection wavelength λ in a two-layer model in which a resin A layer (A layer) and a resin B layer (B layer) are stacked.
2 · (nA · dA · cos θ _A + nB · dB · cos θ _B ) = λ (3)
sinθ = nA · sinθ _A = nB · sinθ _B (4)
Here, n is a refractive index, d is a layer thickness, θ is an incident angle (an angle between an incident vector and an interface normal vector), and alphabets A and B are A layer and B layer, respectively. Show. This will be described in detail with reference to FIGS. When light is vertically incident on the laminated film, θ = θ _A = θ _B = 0 (degrees), and Equation (3) becomes Equation (5).
2 · (nA · dA + nB · dB) = λ (5)
When the A layer is biaxially stretched polyethylene terephthalate, the B layer is copolymerized polyethylene terephthalate, the respective refractive indexes are 1.66 and 1.58, and the lamination ratio is dA / dB = 1, λ = 300 nm is satisfied. The combination of dA and dB is a set having a layer thickness of dA = dB = 46 nm. That is, a group having an average layer thickness of about 46 nm is required. In this way, the same operation is performed from a wavelength of 300 to 500 nm, and a set of necessary layer thicknesses is sequentially obtained. Reflecting the obtained average layer thickness distribution, if the obtained average layer thickness is at least one set in the layer thickness distribution, preferably 10 sets or more continuously, a reflection wall is obtained. At 300 to 500 nm, which is the wavelength of UV to blue light, it is preferable that at least two or more reflection walls exist at different positions in the film thickness direction.

This will be described in detail with reference to FIG. In the layer thickness distribution of FIG. 3A, when the maximum value 20 of the average layer thickness is 60 nm, assuming that the respective refractive indexes are 1.66 and 1.58 and the lamination ratio dA / dB = 1, the equation From (5), the reflection wavelength is 389 nm. On the other hand, if the value of the average layer thickness 22 that reflects UV light having a wavelength of 300 nm is 46 nm, as shown in FIG. To do. Each inclined structure also has a reflecting wall. Therefore, there are three reflecting walls in the film thickness direction in FIG. 3A and two reflecting walls in FIG. 3B. That is, the presence of at least two or more reflective walls at different positions in the film thickness direction means that the layer number or the layer pair number is different and at least two or more layer pairs having the same or close average layer thickness exist in the laminated film. Means that. It is preferable that there are at least 10 or more layer pairs between layer pairs having the same or close average layer thickness. More preferably, the number is 30 or more. FIG. 4 schematically illustrates a synergistic effect of reflection and absorption in incident light 3 having a certain wavelength. Since two or more reflection walls 23 exist at different positions in the film thickness direction, the incident light 3 is confined between the two reflection walls 23, so that light absorption occurs efficiently. FIG. 4A shows a case where there are three reflecting walls 23, and FIG. 4B shows a case where there are two reflecting walls 23. It has been found that the greater the number of reflection walls, the greater the light confinement effect, and thus the synergistic effect of improving the absorption efficiency of the blue light and UV absorbers added to the resin layer.

In the laminated film of the present invention, the long wavelength absorption edge of the dye or UV absorber that absorbs blue light is preferably larger than the long wavelength edge of the reflection band due to interference reflection based on the laminated structure of the layers. This will be described in detail with reference to FIG. Spectral transmission spectrum 81 of the simulation result 80 of the spectral reflectance spectrum of the laminated film that interference-reflects UV to blue light and the monolayer film containing the dye of anthoraquinone pigment that absorbs blue light in cyclohexanedimethanol copolymerized polyethylene terephthalate Is shown in FIG. The horizontal axis represents wavelength W (nm), the left vertical axis represents transmittance T (%), and the right vertical axis represents reflectance R (%). The same applies to FIGS. 9 and 10. In the optical calculation of the laminated film, the number of laminated layers 251 and the thickness 13.5 μm, and the laminated structure shown in FIG. The refractive index of the A layer was 1.66, and the refractive index of the B layer was 1.55. The long wavelength absorption edge 83 means a wavelength at which absorption starts in the spectral transmission spectrum of FIG. 8, and is obtained as an intersection of tangent lines before and after the start of absorption. The contact point for deriving the tangent is an inflection point when the transmission spectrum is differentiated. On the other hand, the long wavelength end 82 of the reflection band due to interference reflection means the wavelength at which reflection starts, and is obtained in the same manner. The intersections between the tangent lines of the respective inflection points and the baselines of the transmittance and the reflectance are the long wavelength absorption ends and the long wavelength ends of the reflection bands. Further, when the light shielding effect by the dye or UV absorber is high and the long wavelength end of the reflection band cannot be clearly derived, the reflection peak 86 seen on the long wavelength side shown in FIG. 9 may be used.

The spectral transmission spectrum and spectral reflection spectrum when the shielding effect is high will be described with reference to FIG. That is, FIG. 9 explains the spectral transmission spectrum and spectral reflection spectrum of a laminated film containing a pigment. In the original reflection spectrum 80, the hatched reflection region 84 is efficiently converted into absorption in accordance with the absorption characteristics of the dye, and the reflection of that portion disappears. On the other hand, the original transmission spectrum 81 completely blocks the speckled transmission region 85 due to reflection from the original reflection spectrum 80. In this way, a slight reflection peak 86 on the long wavelength side that has not disappeared due to the absorption characteristics of the dye is defined as the long wavelength reflection end. When the reflection peak cannot be confirmed and can be regarded as the baseline of the reflection spectrum, the long wavelength absorption edge of the dye or UV absorber that absorbs blue light is the long wavelength of the reflection band due to interference reflection based on the layered structure of the layer It can be considered larger than the edge. From the viewpoint of suppressing in-plane color unevenness, the wavelength at the long wavelength end of the reflection band due to interference reflection based on the layered structure of the layer is compared with the long wavelength absorption end of the dye or UV absorber that absorbs blue light. It is preferably 10 nm or less, and more preferably 20 nm or more.

On the other hand, the reflection peak 87 on the short wavelength side that occurs when the absorption characteristic of the UV absorber on the short wavelength side is weak is the short wavelength end of the reflection band due to interference reflection.

The half width of the reflection spectrum showing the maximum reflectance in the wavelength range of 300 nm to 500 nm of the laminated film of the present invention is preferably less than 30 nm. This is because when the half width is 30 nm or more, reflection is dominant in the UV shielding property, and the synergistic effect due to the combined use with the UV absorber is small. Further, if there is a maximum reflection spectrum having a wide half-value width in the vicinity of 400 nm, it causes coloring. Preferably, it is less than 20 nm. FIG. 10 shows an example in which the full width at half maximum is less than 30 nm, which is a preferred embodiment. Since this has a synergistic effect of reflection and absorption, the maximum reflectance at a reflection wavelength of 311 nm is 38%, and its half-value width is 28 nm. The half-value width is a distance between reflection wavelengths that takes a half value of the maximum reflectance. If the reflectance is too low, the full width at half maximum is widened. Therefore, the full width at half maximum in the present invention is applied to a maximum reflectance of 25% or more and 90% or less. The full width at half maximum of the reflection spectrum having a maximum reflectance of less than 25% and 15% or more is considered to be absent. The half width is determined by the relationship between the absorption characteristics of the UV absorber and the film resin and the reflection characteristics of the laminated film. When the full width at half maximum is large, it indicates that there is little synergistic effect with the absorption characteristic, and it means that there is little overlap between the reflection band and the absorption band.

The molecular weight of the UV absorber added to the laminated film of the present invention preferably includes a triazine skeleton or a benzotriazole skeleton that is 500 or more. This is because when the molecular weight is 500 or more, sublimation hardly occurs, so that bleed-out hardly occurs during casting. More preferably, it is 600 or more. For example, 2,2'-methylenebis [6- (2H-benzotriazol-2-yl) -4- (1,1,3,3-tetramethylbutyl) phenol]:

molecular weight

659, 2,4,6-tris (2-Hydroxy-4-hexyloxy-3-methylphenyl) -1,3,5-triazine: A molecular weight of 700 is preferred. Similarly, the molecular weight of the dye that absorbs blue light is preferably 500 or more from the viewpoint of being hardly sublimated. For example, anthraquinone, isoindolinone, quinnaphthol, monoazo benzene sulfonate, disazo benzimidazole and the like are preferable.

The UV absorber of the present invention is preferably used in combination with an antioxidant having a molecular weight of 10,000 or less from the viewpoint of suppressing oxidative degradation due to ultraviolet rays or heat. Antioxidants include radical scavengers and peroxide decomposers. As radical scavengers, there are mainly hindered amine and hindered phenol compounds.

Examples of hindered phenolic compounds include triethylene glycol-bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-hexanediol-bis [3- (3,5 -Di-t-butyl-4-hydroxyphenyl) propionate], 2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di-t-butylanilino) -1,3,5 -Triazine, pentaerythrityl tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2, 2-thio-diethylenebis [3- (3,5-di-t- Butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, N, N′-hexamethylenebis (3,5-di-t-butyl -4-hydroxy-hydrocinnamamide), 3,5-di-t-butyl-4-hydroxybenzylphosphonate-diethyl ester, 1,3,5-trimethyl-2,4,6-tris (3, 5-di-t-bu Ru-4-hydroxybenzyl) benzene, bis (3,5-di-t-butyl-4-hydroxybenzylphosphonate ethyl) calcium, tris- (3,5-di-t-butyl-4-hydroxybenzyl)- There are isocyanurates, octylated diphenylamines, 2,4, -bis [(octylthio) methyl] -O-cresol, isooctyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate.

As a hindered amine (HALS), the reaction product of cyclohexane and N-

butyl peroxide

2,2,6,6-tetramethyl-4-piperidineamine-2,4,6-

trichloro

1,3,5-triazine And 2-aminoethanol reaction product, N, N ', N' ', N' ''-tetrakis- (4,6-bis- (butyl- (N-methyl-2,2,6,6- Tetramethylpiperidin-4-yl) amino) -triazin-2-yl) -4,7-diazadecane-1,10-diamine, bis (1,2,2,6,6-pentamethyl-4-piperidyl) [[ 3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl] methyl] butyl malonate.

In the laminated film of the present invention, it is preferable that the B layer having a low refractive index is a low refractive index layer, and only the B layer contains a dye or a UV absorber that absorbs blue light, or both. The refractive index can be measured with a well-known Abbe refractometer or prism coupler, and the refractive index here means the refractive index in the in-plane direction. The B layer has a large amount of copolymerization components, so it tends to be amorphous, and low molecular compounds such as dyes and UV absorbers are easily dissolved. On the other hand, the A layer having a high refractive index is biaxially oriented to form a crystal layer, and thus serves as a barrier layer for preventing bleed out.

FIG. 4 shows a state in which the UV absorber 6 is included in the layer (B layer) 2 made of the thermoplastic resin B. The layer (A layer) 1 made of the thermoplastic resin A preferably does not contain UV absorption from the viewpoint of bleeding out. Further, according to Snell's law expressed by the equation (4), in the B layer having a low refractive index compared to the A layer having a high refractive index, the optical path length is increased due to the light propagation angle in the layer being shallow, so that absorption is achieved. It also has the effect of working favorably. More preferably, it is preferable that only the B layer contains a dye or a UV absorber. The extrusion temperature of the layer B is preferably 270 ° C. or lower because the lower the dye or UV absorber is, the lower the extrusion temperature. More preferably, it is 265 ° C. or lower. On the other hand, the A layer is a layer that is oriented and crystallized after being biaxially stretched, and is particularly a resin that forms the outermost layer, so that the UV absorber is likely to precipitate. For example, when the A layer is polyethylene terephthalate, the extrusion temperature is 280 ° C. or higher, so that the layer A is easily sublimated and bleed out easily occurs due to a biaxial extrusion vent or the like.

The laminated film of the present invention preferably has a total light transmittance of 70% or more and a chromaticity b * value in the transmission mode of 5 or less. If the total light transmittance is less than 70%, the brightness as a display or window material and the visibility of an image cannot be secured, which is not preferable. Preferably, the total light transmittance is 80% or more. More preferably, it is 90% or more. More preferably, it is 92% or more. On the other hand, if b * exceeds 5, it is not preferable because it turns yellow when it is made into a polarizing plate. More preferably, it is 3 or less, More preferably, it is 2 or less.

The achievement method is to adopt an optical design that does not exhibit absorption or interference reflection at a wavelength of 500 nm or more in the visible light region having a wavelength of 400 to 700 nm. Specifically, the average layer thickness is 77 nm or less, more preferably 58 nm or less. More preferably, there is no absorption or interference reflection in the visible light region having a wavelength of 400 nm or more. In particular, in a UV shielding film, it is preferable from the surface which suppresses coloring that the wavelength of a maximum reflectance shall be 380 nm or less. More preferably, the reflection wavelength on the longest wavelength side is 380 nm or less, more preferably 370 nm or less.

The dye and / or UV absorber used in the laminated film of the present invention, or both, has an extinction coefficient of an absorption peak in the wavelength range of 300 nm to 500 nm of 0.06 [wt% · μm] ^−1. The above is preferable. The extinction coefficient ε can be obtained from a well-known analysis method from Equation (5) obtained by modifying Equation (1). That is, by determining the thickness x [μm] of the laminated film, the addition concentration c [wt%] of the entire film of the dye or UV absorber that absorbs blue light, and the transmittance for each wavelength, the extinction coefficient ε is obtained. Can be sought. The extinction coefficient is a value obtained by dividing the absorption coefficient k of the laminated film by the addition concentration c of the UV absorber.
I = IoExp (−εcx)
ln (I / Io) = − εcx (6)

The laminated film of the present invention preferably has a transmittance at a wavelength of 370 nm of 5% or less. If it exceeds 5%, it becomes impossible to protect the liquid crystal layer from UV light as a polarizer protective film and to prevent curing of the photosensitive resin as a cover film. More preferably, it is 2% or less. This is achieved by using an optical design in which the set of layers satisfying the average layer thickness of 45 to 60 nm is 100 or more and using a UV absorber having a long wavelength absorption edge of 380 nm or more.

The average layer thickness distribution of the laminated film of the present invention preferably has two or more inclined structures, and the number of layer pairs having an average layer thickness of 40 nm or more and 60 nm or less is 80% or more of the total number of layer pairs. . If the layer pair of the UV reflecting walls is 80% or more, almost all the layers act on the function of shielding blue light and UV light, so that the thinning is possible.

In the laminated film of the present invention, it is preferable that a photocurable or thermosetting resin layer C is formed on at least one surface from the viewpoint of preventing scratches. As the photocurable type, methacrylic resin, photocurable polychlorobiphenyl, alicyclic epoxy resin, photocationic polymerization initiator, acrylate-based resin (containing Si, F), photoradical, polymerization initiator, fluorinated polyimide, etc. are used. be able to. Further, as the thermosetting type, any resin such as epoxy, phenol, urethane, acrylic, and polyester containing a crosslinking agent may be used. The resin constituting the membrane may be a single polymer or a mixture.

The resin layer C is preferably urethane acrylate, polymer acrylate, or organic-inorganic hybrid resin from the viewpoint of optical use. As the resin layer C, a more preferable one is one that is difficult to curl and has good adhesion to the substrate, and includes low-shrinkage urethane acrylate. Specific examples of urethane acrylates include AT-600, UA-101l, UF-8001, UF-8003, etc. manufactured by Kyoeisha Chemical Co., Ltd., UV7550B, UV-7600B manufactured by Nippon Synthetic Chemical Co., Ltd., and U manufactured by Shin-Nakamura Chemical Co., Ltd. -2PPA, UA-NDP, etc., such as Ebecryl-270, Ebecryl-284, Ebecryl-264, Ebecryl-9260, etc. manufactured by Daicel UCB, or an epoxy compound, specifically, EHPE3150, GT300 manufactured by Daicel Chemical Industries, Ltd. GT400, Celoxide 2021, etc., and EX-321, EX-411, EX-622, etc. manufactured by Nagase Chemtech. However, it is not limited to this.

Further, among urethane acrylates that can achieve higher hardness, urethane acrylate oligomers and monomers can be obtained by reacting polyhydric alcohols, polyvalent isocyanates, and hydroxyl group-containing acrylates. Specifically, UA-306H, UA-306T, UA-306l manufactured by Kyoeisha Chemical Co., Ltd., UV-1700B, UV-6300B, UV-7600B, UV-7605B, UV-7640B, UV manufactured by Nippon Synthetic Chemical Co., Ltd. -7650B etc., Shin-Nakamura Chemical U-4HA, U-6HA, UA-100H, U-6LPA, U-15HA, UA-32P, U-324A etc., Daicel UCB ebecryl-1290, Ebecryl -1290K, Ebecryl-5129, etc., such as UN-3220HA, UN-3220HB, UN-3220HC, UN-3220HS, manufactured by Negami Kogyo Co., Ltd., UNIDS series EQS-650, EPS-832, EPS-1259, 17- 806, RS28-444, and the like. However, it is not limited to this.

The laminated film of the present invention preferably contains a thermoplastic resin copolymerized with a UV absorber. Since the UV absorber is a low molecule, it easily volatilizes and bleeds out easily. Therefore, when a UV absorber is copolymerized with a thermoplastic resin, it has a high molecular weight and is difficult to bleed out. In the present invention, from the viewpoint of compatibility, it is preferable that a UV absorber is copolymerized with a polyester resin such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, and polybutylene naphthalate. The molecular weight is 10,000 or more, more preferably 20,000 or more. The UV absorber is preferably benzophenone, benzotriazole, or triazine, but is not particularly limited. From the viewpoint of reactivity to become a copolymer, a UV absorber having a hydroxyl group, an end of a carboxyl group, or an ester bond as a functional group is preferable.

In particular, it is preferable to have two or more of these functional groups from the viewpoint of developing high UV absorption performance. For example, among the above-mentioned UV absorbers having a plurality of functional groups, THBP (2,2 ′, 4,4′-tetrahydroxybenzophenone), 2-hydroxy-4methoxy-benzophenone, 2,2′-hydroxy-4 , 4'-dimethoxybenzophenone, 2- [2-hydroxy-5- [2- (methacryloyloxy) ethyl] phenyl] -2H-benzotriazole], particularly bisbenzotriazole compounds are particularly preferred from the viewpoint of copolymerization.

Specific examples of the bisbenzotriazole compound include, for example, 2,2′-methylenebis [6- (2H-benzotriazol-2-yl) -2,4-dihydroxybenzene], 2,2′-methylenebis [6- (2H -Benzotriazol-2-yl) -4- (hydroxymethyl) phenol], 2,2'-methylenebis [6- (2H-benzotriazol-2-yl) -4- (2-hydroxyethyl) phenol], 2 , 2'-methylenebis [6- (5-chloro-2H-benzotriazol-2-yl) -4- (2-hydroxyethyl) phenol], 2,2'-methylenebis [6- (5-bromo-2H- Benzotriazol-2-yl) -4- (2-hydroxyethyl) phenol], 2,2′-methylenebis [6- (2H-benzotriazol-2-yl) -4 -(3-Hydroxypropyl) phenol], 2,2'-methylenebis [6- (5-chloro-2H-benzotriazol-2-yl) -4- (3-hydroxypropyl) phenol], 2,2'- Methylenebis [6- (5-bromo-2H-benzotriazol-2-yl) -4- (3-hydroxypropyl) phenol], 2,2′-methylenebis [6- (2H-benzotriazol-2-yl)- 4- (2-hydroxypropyl) phenol], 2,2′-methylenebis [6- (5-chloro-2H-benzotriazol-2-yl) -4- (2-hydroxypropyl) phenol], 2,2 ′ -Methylenebis [6- (5-bromo-2H-benzotriazol-2-yl) -4- (2-hydroxypropyl) phenol], 2,2'-methylenebis [6- (2 -Benzotriazol-2-yl) -4- (4-hydroxybutyl) phenol], 2,2'-methylenebis [6- (5-chloro-2H-benzotriazol-2-yl) -4- (4-hydroxy Butyl) phenol], 2,2′-methylenebis [6- (5-bromo-2H-benzotriazol-2-yl) -4- (4-hydroxybutyl) phenol], 3,3- {2,2′- Bis [6- (2H-benzotriazol-2-yl) -1-hydroxy-4- (2-hydroxyethyl) phenyl]} propane, 2,2- {2,2′-bis [6- (2H-benzo And triazol-2-yl) -1-hydroxy-4- (2-hydroxyethyl) phenyl]} butane.

The bisbenzotriazole compound can be used alone or in combination of two or more. The copolymerization amount of the bisbenzotriazole compound is 0.01 to 50% by weight, preferably 0.1 to 30% by weight, more preferably 0.5 to 20% by weight. If the amount used is less than 0.01% by weight, the resulting copolymer polyester does not have sufficient UV absorption performance, and if it exceeds 50% by weight, the mechanical properties of the copolymer polyester deteriorate. From the viewpoint of effectively exhibiting high UV shielding performance, a UV-absorbing copolymer polyester resin containing 1% by weight or more of the UV absorber as a copolymer component is preferable. More preferably, it is 3% by weight or more. More preferably, it is 5% by weight. Since these UV-absorbing copolyesters do not bleed out, they can be used in either the A layer, the B layer, or both. When used in combination with a UV absorber, it is preferably used for the A layer having high crystallinity.

The laminated film according to the present invention is preferably used as a screen protective film. FIG. 5 shows the configuration of a laminated film that is a screen protection film. The laminated film 5 of the present invention in which the hard coat 24 made of the resin layer C is provided on the cover glass 26 on the outermost surface of the casing 27 of a television, personal computer monitor, smartphone, tablet or the like via the adhesive 25. By sticking, it is possible to provide an electronic device casing having scattering prevention properties and UV or blue light cutting properties. In particular, it is preferable for external light from the sun because it can suppress resin deterioration inside the liquid crystal panel by having UV shielding properties.

The laminated film of the present invention is preferably a polarizer protective film. FIG. 6A shows a polarizing plate 30 in which the laminated film 5 and the polarizer protective film 29 of the present invention sandwich the PVA polarizer 28. An example of a configuration diagram of a liquid crystal panel using the laminated film of the present invention is shown in FIG. The laminated film of the present invention is preferably used at the front position of the upper polarizing plate 32 of the liquid crystal panel or the rear position of the lower polarizing plate from the viewpoint of preventing rainbow unevenness and having UV shielding properties.

Furthermore, as shown in FIG. 6C, when the laminated film 5 of the present invention is used at the front position of the upper polarizing plate 32, the main alignment axis 35 of the laminated film and the linear polarization direction (transmission) of the PVA polarizer. The angle 36 formed with the (azimuth) 34 is preferably 20 degrees or more and 70 degrees or less from the viewpoint of preventing blackout. Blackout is a phenomenon in which the liquid crystal display becomes dark and disappears when an observer views the display through polarized sunglasses. By making the angle between the main alignment axis of the laminated film of the present invention and the polarization direction of the PVA polarizer to be 20 degrees or more and 70 degrees or less, linearly polarized light emitted from the PVA polarizer is caused by the birefringence of the laminated film. Elliptically polarized light leaks. This is a preferable configuration because an observer can visually recognize an image even when wearing polarized sunglasses. On the other hand, from the viewpoint of reducing light leakage in the prior art, the narrow angle of the angle between the main alignment axis and the in-plane orientation of linearly polarized light by the PVA polarizer of the upper polarizing plate of the liquid crystal display is 10 degrees or less. It is preferable that

The preferable retardation of the laminated film is preferably 60 to 280 nm from the viewpoint of a large amount of light transmission. From the viewpoint of achromatic color, the phase difference is more preferably 60 to 200 nm. More preferably, it is 80 to 150 nm. On the other hand, the preferred range of the thickness direction retardation is 50 nm or more and 800 nm or less, and more preferably 80 nm or more and 400 nm or less from the viewpoint of light transmittance without interference color. Most preferably, it is 100 nm or more and 300 nm or less. In addition, the thickness direction phase difference in this invention is a phase difference in the viewing angle of 50 degree | times measured with the automatic birefringence meter KOBRA by Oji Scientific Instruments. In the laminated film of the present invention, the lamination ratio is preferably 1 or less from the viewpoint of thickness retardation and bleed out. More preferably, it is 0.7 or less. More preferably, it is 0.5 or less.

The laminated film of the present invention is preferably used for a liquid crystal display. FIG. 6B shows a liquid crystal panel using the laminated film of the present invention. The liquid crystal display has three configurations: a front panel made of an antireflection film, a touch panel, etc., the liquid crystal panel shown in FIG. 6B, and a backlight. As the backlight, an LCD backlight system composed of at least an LED light source, a reflective film, a light guide plate, a light diffusing sheet, and a prism sheet is preferably used in terms of luminance and versatility.

In addition, the laminated film of the present invention preferably has a total light transmittance of 91% or more and a haze of 2% or less from the viewpoint of transparency used in a display. More preferably, they are 92% or more and 1% or less, respectively. More preferably, it is 93% or more. In the conventional 1 to 3 layers of polyester film, it is difficult to improve the total light transmittance due to interference caused by optical distance on the order of microns. However, in the laminated film of the present invention, the thickness of all layers is preferably 60 nm or less. In particular, when the thickness of each layer of at least 4 layers, preferably 8 layers or more, counted from the surface layer, is 30 nm or less, the optical distance configuration does not affect the transmittance in the visible light region, and the high total light transmittance Can be realized. In particular, the transmittance can be particularly improved by forming an acrylic easy-adhesion layer having a refractive index of 1.51 or less with a coating thickness of 70 nm or more.

In this invention, it is a liquid crystal display comprised in order of the upper polarizing plate, the liquid crystal layer, and the lower polarizing plate, Comprising: In an upper polarizing plate or a lower polarizing plate, the laminated film of this invention is a polarizer on the opposite surface to the liquid crystal layer side. It is preferable that it is a liquid crystal display which arrange | positions a laminated film as a protective film.

The laminated film of the present invention is preferably used for a touch panel. An example of a schematic diagram of an out-cell type touch panel including the laminated film of the present invention is shown in FIG. The touch sensor unit is composed of at least a cover glass 37 and a conductive layer 38. The touch panel of the present invention may be any of a resistance film type, an optical type, and a capacitance type. Capacitance type can be roughly divided into projection type and surface type. From the viewpoint of enabling multi-touch, the projection capacitance type is most preferable. The conductive layer is made of metal such as gold, silver, platinum, palladium, rhodium, indium, copper, aluminum, nickel, chromium, titanium, iron, cobalt, tin, and alloys thereof, tin oxide, indium oxide, titanium oxide, It can be formed by a composite film such as a metal oxide film such as antimony oxide, zinc oxide, cadmium oxide, indium tin oxide (ITO), or copper iodide. A thin film can be obtained from these transparent conductive films by vacuum deposition, sputtering, reactive RF ion plating, spray pyrolysis, chemical plating, electroplating, CVD, coating, or a combination thereof.

In addition, as the conductive polymer, polypyrrole, polyaniline, polyacetylene, polythiophene, polyphenylene vinylene, polyphenylene sulfide, poly-p-phenylene, polyheterocycle vinylene, particularly preferably (3,4-ethylenedioxythiophene) ) (PEDOT). In addition, carbon nanotubes and nano silver are preferable because they exhibit high conductivity. These can be applied to a substrate by a coating method by dissolving in an organic solvent. As the coating method, various methods can be adopted in the same manner as the hard coat layer method. From the viewpoint of versatility, ITO is preferable.

¡Out-cell type touch sensors can be broadly divided into glass sensors and film sensors. Glass sensor types include GG, GG2, G2, and G1M. GG is cover glass / ITO / glass / ITO, GG2 is cover glass / glass / ITO / insulating layer / ITO, G2 (OGS) is cover glass / ITO / insulating layer / ITO, G1M is cover glass / ITO Is a basic configuration.

From the viewpoint of preventing scattering and suppressing blackout, it is preferable to use the laminated film of the present invention between the touch panel and the liquid crystal panel. In this case, it is particularly preferable to use a glass sensor type, and FIG. 7B shows a configuration example using the laminated film 5 of the present invention.

On the other hand, as a film sensor type, there are GFF, GF2, G1F, GF1, PFF, and PF1, and any of them may be used. GFF is cover glass / ITO / film / ITO / film, GF2 is cover glass / ITO / film / ITO, or cover glass / ITO / insulating layer / ITO / film, and G1F is cover glass / ITO / ITO. / Film, GF1 is a cover glass / ITO / film, and PFF is a cover plastic / ITO / film / ITO / film, P1M cover plastic / ITO. FIG. 7C shows an example of a GF1 type TP structure in which an ITO electrode layer 38 is formed using the laminated film 5 of the present invention as a base film. The thickness of the laminated film 5 as a base material is preferably 50 μm or less, more preferably 40 μm or less from the viewpoint of thinning. If it is too thin, it is preferably 10 μm or more and 40 μm or less from the viewpoint of the handleability of the film. The GF1 type is preferred as a touch sensor due to the recent trend of thinning displays.

The laminated film of the present invention is preferably used for protecting a polarizer at the front position of a circularly polarizing plate used for preventing reflection of external light in an organic EL display. The organic EL light emission method may be a RGB primary color type or a white type.

Describe the property value evaluation method.

(Method for evaluating physical properties)
(1) Layer thickness, number of layers, layered structure The layer structure of the layered film was determined by observation with a transmission electron microscope (TEM) for a sample obtained by cutting a cross section using a microtome. That is, using a transmission electron microscope H-7100FA type (manufactured by Hitachi, Ltd.), the cross section of the film was magnified 10,000 to 40,000 times under the condition of an acceleration voltage of 75 kV, a cross-sectional photograph was taken, Each layer thickness was measured. In some cases, in order to obtain high contrast, a staining technique using a known RuO ₄ or OsO ₄ was used.

About 40,000 times TEM photographic image obtained from the above device is saved to a personal computer as a compressed image file (JPEG) by processing at a print magnification of 620,000, and then image processing software Image-Pro This file was opened using Plus ver.4 (distributor Planetron Co., Ltd.) and image analysis was performed. In the image analysis processing, the relationship between the thickness in the thickness direction and the average brightness of the region sandwiched between the two lines in the width direction was read as numerical data in the vertical thick profile mode. Using spreadsheet software (Excel 2007), the low-pass filter 10 × 10 was adopted after adopting the data in the sampling step 1 (no thinning) for the position (nm) and brightness data. Furthermore, the data obtained by periodically changing the brightness is differentiated, and the maximum value and the minimum value of the differential curve are read by a VBA (Visual Basic For Applications) program. It was calculated as the layer thickness of one layer. This operation was performed for each photograph, and the layer thicknesses of all layers were calculated. Then, the average layer thickness distribution for each layer pair of the adjacent A layer and B layer is calculated by data processing for all layers, and the horizontal axis indicates the layer pair number and the vertical axis indicates the average layer thickness distribution. It was created.

(2) Measurement of spectral transmittance and relative spectral reflectance at a wavelength of 250 to 800 nm A 5 cm square sample was cut out from the central portion of the laminated film in the film width direction. Next, using a spectrophotometer (U-4100 Spectrophotometer) manufactured by Hitachi High-Technologies, the spectral transmittance and the relative reflectance at an incident angle φ = 10 degrees were measured. 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 800 nm, the slit was 2 nm (visible), the gain was set to 2, and the scanning speed was measured at 600 nm / min. The minimum value of the spectral transmittance in the wavelength range of 300 to 500 nm and its wavelength were determined. Moreover, about the laminated | multilayer film which added the UV absorber, the transmittance | permeability in wavelength 370nm was also employ | adopted as a measured value. On the other hand, regarding the reflectance, the maximum value of the relative spectral reflectance in the wavelength range of 300 to 500 nm and its wavelength were obtained.

(3) Transmittance measurement at a wavelength of 370 nm at a light incident angle of 60 degrees Using the same device as (2) above, the attached variable angle absolute reflectance device (20-60 °) P / N134-0115 (revised) The angle variable transmittance was measured by installing. The measurement conditions were the same as in item (2), and transmittance measurements were performed in the P wave and S wave wavelength sections of 250 to 800 nm at an incident angle of 60 °. The light source mask size and sample size were changed according to the device manual. An average transmittance curve in the wavelength range of 250 nm to 800 nm for the P wave and the S wave was obtained, and in particular, the transmittance at a wavelength of 370 nm was obtained.

(4) Total light transmittance and haze A sample at the center in the width direction of the film was cut out at 5 cm × 5 cm, and in accordance with JIS K7105, the total light transmittance and haze were measured using a haze meter (Suga Test Instruments HGM-2DP (for C light)). Was measured.

(5) Colorimetric value (b *)
The laminated film was cut out at 5 cm × 5 cm from the center in the width direction, and the a * and b * values in the transmitted light were measured using CM-3600d manufactured by Konica Minolta, and the average value of n number 5 was obtained. CM A-103 attached to the device was used for the white calibration plate, and CM-A104 attached to the device was used for the zero calibration box. As the chromaticness index a *, b *, a value calculated by the apparatus based on JIS Z8722 (2000) under the conditions of D65 as a light source and a 10 ° field of view was adopted.

(6) Retardation (Retardation) Value A phase difference measuring device (KOBRA-WPR) manufactured by Oji Scientific Instruments was used. A film sample cut out at 3.5 cm × 3.5 cm was placed in the apparatus, and retardation at a wavelength of 590 nm at an incident angle of 0 ° was measured. When measuring the retardation in the thickness direction, the value of Rth at an incident angle of 50 ° was used. Sampling was performed from the center in the film width direction, and sampling was performed from three points at 50 mm intervals in the film longitudinal direction, and the average value was used. Moreover, the narrow angle formed by the film width direction and the slow axis was determined as the orientation angle, and was used as the main orientation axis of the laminated film.

(7) Bleed-out Bleed-out is a haze after heat treatment of the obtained film at 150 ° C. for 1 hour in about 2 hours of film formation and the degree of deposition of the strands of the electrostatic application device and the UV absorber around the cast drum The following criteria were used for evaluation of the increase in
S: No deposit and haze increase of 0.5% or less A: No deposit and haze increase of greater than 0.5%, 1.0% or less B: No deposit and haze increase of greater than 1.0% 2.0% or less C: Sediment is slightly present and haze rise is larger than 2.0% D: Deposit is present and haze rise is larger than 2.0%.

(8) In-plane color unevenness The obtained laminated film was cut into A4 size from the central part in the film width direction, a black layer was applied to the back surface by a black spray, and light was projected from the film surface using a three-wavelength fluorescent lamp. The in-plane color unevenness state of the film due to the reflected light was evaluated according to the following criteria.
B: The reflected light is colorless and visible as white fluorescent light.
C: A purple reflected color can be visually recognized partially in the plane.
D: Reflection colors such as purple and blue can be visually recognized in the entire area.

(9) Shielding property against blue light or UV light The shielding property against blue light or UV light of the obtained film was evaluated according to the following criteria.
In Examples 26 to 28 and Comparative Examples 7 to 9, evaluation was performed based on a high transmittance value among the transmittances of blue light at an incident angle of 0 ° and 60 ° at a wavelength of 460 nm.
A: Transmittance of 40% or more and less than 65% B: Transmittance of 65% or more and less than 75% C: Transmittance of 75% or more and less than 80% D: Transmittance of 80% or more or less than 40% In 1 to 25, 33 to 36, and Comparative Examples 1 to 6, the UV light was evaluated based on the transmittance at an incident angle of 0 ° and 60 ° at a wavelength of 370 nm.
A: Both transmittances at an incident angle of 0 ° and 60 ° are 2% or less. B: The transmittance at an incident angle of 0 ° is larger than 2% and 3% or less, and the transmittance at 60 ° is 5% or less. C: The transmittance at an incident angle of 0 ° is greater than 3% and 4% or less, and the transmittance at 60 ° is greater than 5% and 20% or less.

(10) Product of Film Thickness and UV Absorber Concentration The film thickness was measured using an electronic micrometer manufactured by Millitron with a set of main body model 1240, gauge head, measuring stand and the like. The sample was cut out from the center of the film width direction position at 5 cm × 5 cm square, and the thickness measurement result was read to the submicron unit.

The concentration (%) of the UV absorber in the laminated film was determined from the added weight of the raw material of the UV absorber in the production process of the laminated film. Specifically, a UV master chip containing 10% by weight of a UV absorber in advance in the thermoplastic resin A or B used for the A or B layer is prepared, and diluted to obtain UV contained in the laminated film. The concentration of the absorbent was adjusted.

On the other hand, the method of determining the concentration of the UV absorber from the laminated film is to obtain the absorption coefficient k from the relationship between the thickness and the transmittance using the formula (1). Moreover, since the absorption coefficient k is a product of the concentration c and the absorption coefficient, the laminated film is dissolved with a solvent, a test body with the concentration c changed is produced, and the concentration c is determined by measuring the respective transmittances. it can. In addition, the concentration of the UV absorber in the laminated film can be easily determined by using a known analysis technique. The analysis method from a film is shown below.

The weight of the laminated film cut out in 1 cm square is measured and dissolved sufficiently in methylene chloride or HFIP / methylene chloride solvent. In the range of 1 mL to 5 mL of solvent, dissolve the film sequentially and collect the concentration dependence data of the spectrum in the ultraviolet wavelength region. Paying attention to a specific absorption peak wavelength λnm, A _{λ1 represents} the absorbance derived from a known UV absorber measured at 0.02 [mg / mL], and A _{λ2 represents} the absorbance obtained from the film solution diluted x-fold. In this case, the UVA concentration in the film can be calculated as 0.02 × A _λ2 / A _λ1 × x [mg]. When the weight of the film measured in advance is y [mg], the weight percent concentration of UVA added in the film is expressed by the formula of 0.02 × A _{λ 2} / A _{λ 1} × x / y × 100 [wt%]. It is obtained by.

When calculating the product of the film thickness and the UV absorber concentration, the product was calculated as the product of the thickness [μm] of the laminated film and the value obtained by dividing the weight percent of the UV absorber by 100 as shown in Table 2. .

(11) Rainbow unevenness evaluation In a dark room at 23 ° C., a white screen was displayed on a 42-inch liquid crystal monitor of an LED light source, and an A4 size laminated film was placed thereon. By observing the laminated film while changing the in-plane azimuth angle of 0 to 360 ° and the elevation angle from 40 ° to 80 ° with reference to the pole in the direction perpendicular to the surface of the film, the colored state of rainbow unevenness is observed, Evaluation was made according to the following criteria.
A: The coloring is not visually recognized at all and there is no problem.
B: Although a slight blue color is visually recognized, there is no problem.
C: Slightly light red and yellow are visually recognized.
D: A plurality of colors are confirmed as rainbow unevenness, which is a problem.
(12) Refractive index The refractive index of the thermoplastic resin was measured according to JIS K7142 (1996) A method. That is, a sheet was produced by pressing from a molten state and then rapidly cooling to prepare a sample. Regarding the refractive indexes of the A layer and the B layer, orientation and thermal crystallization are accompanied by stretching and heat treatment. The refractive index in the biaxial stretching direction in the film surface obtained by sequential biaxial stretching using IV) and heat treatment was measured according to JIS K7142 (1996) A method.

(Thermoplastic resin)
The following were prepared as the resin A.
(Resin A-1) To a mixture of 100 parts by weight of dimethyl terephthalate and 60 parts by weight of ethylene glycol was added 0.09 parts by weight of magnesium acetate and 0.03 parts by weight of antimony trioxide with respect to the amount of dimethyl terephthalate. Transesterification is performed by heating and raising the temperature by a conventional method. Subsequently, 0.020 part by weight of 85% aqueous phosphoric acid solution is added to the transesterification product with respect to the amount of dimethyl terephthalate, and then the polycondensation reaction layer is transferred. Further, the reaction system was gradually depressurized while being heated and heated, and a polycondensation reaction was performed at 290 ° C. under a reduced pressure of 1 mmHg by a conventional method to obtain polyethylene terephthalate having IV = 0.61. Refractive index 1.58. The refractive index is 1.66 after biaxial stretching and after heat treatment.

(Resin A-2)
Polyethylene naphthalate having IV = 0.43 obtained by polycondensation of naphthalene 2,6-dicarboxylic acid dimethyl ester (NDC) and ethylene glycol (EG) by a conventional method. Refractive index 1.64. After biaxial stretching and heat treatment, the refractive index is 1.76.
(Resin A-3)
It is a thermoplastic resin in which a UV absorber is copolymerized. IV = 0.65, a copolymer obtained by copolymerizing 3% by weight of UV absorber B2 (2,2′-methylenebis [6- (2H-benzotriazol-2-yl) -4- (2-hydroxyethyl) phenol]) Polymerized polyethylene terephthalate. Refractive index 1.585. The refractive index is 1.64 after biaxial stretching and heat treatment.

(Resin A-4)
It is a thermoplastic resin in which a UV absorber is copolymerized. IV = 0.75, polybutylene terephthalate (TK1058C01 manufactured by Bell Polyester Products) obtained by copolymerizing 18% by weight of UV absorber B3 (benzotriazole-based UV absorber). Melting point 180 ° C, glass transition point 61 ° C.

(Resin A-5)
IV = 0.64 Polyethylene naphthalate copolymerized with 12 mol% of isophthalic acid. Refractive index 1.64. After biaxial stretching and heat treatment, the refractive index is 1.74.

(Resin B-1) IV = 0.73 Polyethylene terephthalate copolymerized with spiroglycol (SPG 30 mol%) and cyclohexanedicarboxylic acid (CHDA 20 mol%). Refractive index 1.55.

(Resin B-2) Polyethylene terephthalate copolymerized with IV = 0.72 cyclohexanedimethanol (CHDM 30 mol%). Refractive index 1.57.

(Resin B-3) IV = 0.64 Polyethylene terephthalate copolymerized with 17 mol% of isophthalic acid component. Refractive index 1.58.

(Resin B-4) Copolymerized polyethylene terephthalate obtained by mixing Resin A-1 and Resin B-2 at 1: 3. Refractive index 1.6
(Resin B-5) Copolymerized polyethylene terephthalate in which resin A-1 and resin B-2 are mixed at a ratio of 1: 1. Refractive index 1.62
(Resin B-6) Polyethylene terephthalate copolymerized with 30 mol% of naphthalenedicarboxylic acid component. Refractive index 1.6.

(UV absorber and dye)
As shown in Table 1, A1 (2,4,6-tris (2-hydroxy-4-hexyloxy-3-methylphenyl) -1,3,5-triazine), A2 (2- (2- ( 4,6- (4-biphenyl) -1,3,5-triazin-2-yl) -5- (2-ethylhexyloxy) -phenol), A3 (2- (4,6-diphenyl-1,3, 5-triazin-2-yl) -5- [2- (2-ethylhexanoyloxy) ethoxy] phenol), B1 of benzotriazole skeleton (2,2′-methylenebis [6- (2H-benzotriazole-2- Yl) -4- (1,1,3,3-tetramethylbutyl) phenol]), B2 (2,2′-methylenebis [6- (2H-benzotriazol-2-yl) -4- (2-hydroxy) Ethyl) phenol]), C (2,2 '-(1,4-phenylene) bis (4H-3,1-benzoxazin-4-one)) of benzoxazine skeleton, benzophenone bone Of D (bis (5-benzoyl-4-hydroxy-2-methoxyphenyl) methane), was prepared E of quinophthalone a yellow dye, a UV absorber mono azobenzene sulfonate F, B3 benzotriazole skeleton.

(Primer coat)
Resin solution (a): Acrylic resin solution cross-linking agent (b) comprising methyl methacrylate, ethyl acrylate, acrylic acid, N-methylol acrylamide, polyethylene glycol monomethacrylate having 16 repeating units of ethylene oxide, 2-sulfoethyl acrylate: Methylol-based melamine crosslinking agent particles (c): aqueous dispersion of colloidal silica particles having a particle diameter of 80 nm.
Fluorosurfactant (d)
These were mixed at a solid content weight ratio of (a) / (b) / (c) / (d) = 30 parts by weight / 8 parts by weight / 2 parts by weight / 0.6 parts by weight.

[Example 1]
(Laminated film production)
After the resin A-1 as the thermoplastic resin A is vacuum-dried at 180 ° C. for 3 hours, the resin B-1 as the thermoplastic resin B is dried under nitrogen at 80 ° C. Then, they were respectively put into a single screw extruder and a twin screw extruder, melted at extrusion temperatures of 280 ° C. and 265 ° C., respectively, and kneaded. A nitrogen purge was performed on the lower part of the hopper. Subsequently, foreign matters such as oligomers and impurities were removed by vacuum venting at a vacuum pressure of 0.1 kPa or less at two vent holes of the twin screw extruder. Moreover, Q / Ns which is the ratio of the feedstock to the twin screw extruder and the screw rotation speed was set to 1.5. After passing through 10 FSS type leaf disk filters each with a filtration accuracy of 6 μm, and measuring with a gear pump so that the discharge ratio (lamination ratio) is thermoplastic resin A / thermoplastic resin B = 1/2, A 291-layer laminating apparatus using the same principle as the laminating apparatus described in Japanese Patent No. 4552936 was used to form a laminated body in which 291 layers were alternately laminated in the thickness direction. Note that 0.9 wt% of the UV absorber A1 was added to the thermoplastic resin B-1. Further, the slit length and the gap were adjusted so as to obtain an upwardly convex layer thickness distribution, and a single-layer laminating apparatus using only the slit plate 72 of the laminating apparatus 7 in FIG. 2 was obtained. Each of the A layer and the B layer was a laminate having two inclined structures shown in FIG. In the two inclined structures, A layer and B layer are alternately laminated with 291 layers, and the two inclined structures are arranged so that the layer thickness is the thinnest in the vicinity of both surfaces of the laminated film. . Moreover, the slit design which makes the inclination which is ratio of maximum layer thickness / minimum thickness 1.25 was employ | adopted.

Next, the laminate is supplied to a T-die and formed into a sheet, and then rapidly cooled and solidified on a casting drum whose surface temperature is maintained at 25 ° C. while applying an electrostatic applied voltage of 8 kV with a wire, and unstretched A film was obtained. This unstretched film was stretched 3.2 times in the longitudinal direction of the film at 105 ° C. with a longitudinal stretching machine, subjected to corona treatment, and a primer coat was applied to both sides with a # 4 metabar. Next, both ends are guided to a tenter gripped by clips, and stretched by a factor of 3.4 in the film width direction at 110 ° C., followed by a heat treatment at 200 ° C., and a relaxation treatment in the film width direction of about 3% at 150 ° C. The laminated film having a thickness of 14 μm was obtained. The layer thickness distribution of the obtained laminated film includes two inclined structures for each of the A layer and the B layer. From the surface layer side to the 145th layer in the center in the thickness direction, both the A layer and the B layer have a layer thickness. Had an inclined structure that increased asymptotically. The average layer thickness distribution of the adjacent A layer and B layer had a convex layer thickness distribution in which the average layer thickness of 60 nm was an asymptotic line. The obtained laminated film has a UV absorber concentration of 0.6% by weight, a maximum value of relative reflectance by a spectrophotometer of 81%, a half width of 15 nm, and a transmittance of 1 in a wavelength range of 380 nm or less. %, Which is a good UV shielding property of not more than%. Low concentration addition of UV absorber, low molecular weight, and added layers are not exposed on the surface layer, so it was a laminated film suitable for a colorless and transparent polarizer protective film that does not bleed out and has no in-plane color unevenness . The product of the film thickness 14 (μm) and the UV absorber concentration was 0.08. Table 2 shows the evaluation results of the laminated film obtained.

[Example 2]
The number of slits of the slit plate of Example 1 was changed to be a 271 layer laminating apparatus with two inclined structures. Further, 271 layers were added to the thermoplastic resins A-1 and B-1 in the same manner as in Example 1 except that 0.5 wt% and 1.5 wt% of the UV absorber A-1 were added, respectively. A laminated film having a thickness of 13.5 μm was obtained. The obtained laminated film has a UV absorber concentration of 1.17% by weight, a maximum relative reflectance by a spectrophotometer of 70%, and a good UV having a transmittance of 1% or less in a wavelength range of 380 nm or less. It showed shielding properties. Further, it was a laminated film suitable for a colorless and transparent polarizer protective film without bleeding out and without in-plane color unevenness. The product of the film thickness and the UV absorber concentration was 0.16. Table 2 shows the evaluation results of the laminated film obtained.

[Example 3]
A laminated film of 271 layers and a thickness of 13.5 μm was formed in the same manner as in Example 2 except that the discharge ratio (lamination ratio) by the gear pump was changed so that thermoplastic resin A / thermoplastic resin B = 1/1. Obtained. The obtained laminated film has a UV absorber concentration of 1.0% by weight, a maximum relative reflectance of 90% by a spectrophotometer, and a good UV having a transmittance of 1% or less in a wavelength range of 380 nm or less. It showed shielding properties. Further, it was a laminated film suitable for a colorless and transparent polarizer protective film without bleeding out and without in-plane color unevenness. The product of the film thickness and the UV absorber concentration was 0.14. Table 2 shows the evaluation results of the laminated film obtained.

[Example 4]
In the thermoplastic resin B-1, a laminated film having 271 layers and a thickness of 13 μm was obtained in the same manner as in Example 3 except that the UV absorber A1 was changed to C and the concentration was added by 1.8% by weight. . The obtained laminated film has a UV absorber concentration of 0.9% by weight, a maximum value of relative reflectance by a spectrophotometer of 42%, and a good UV having a transmittance of 1% or less in a wavelength range of 370 nm or less. It showed shielding properties. Further, it was a laminated film suitable for a colorless and transparent polarizer protective film without bleeding out and without in-plane color unevenness. The product of the film thickness and the UV absorber concentration was 0.12. Table 2 shows the evaluation results of the laminated film obtained.

[Example 5]
As shown in Table 2, UV absorbers A1 and A2 were added to only the B layer on the low refractive index layer side so as to be 1.3% and 0.5%, respectively. A laminated film having a thickness of 13 μm was obtained in the same manner as in Example 3 except that 7. The obtained laminated film has a UV absorber concentration of 0.14% by weight, a maximum value of relative reflectance by a spectrophotometer of 40%, and a good UV having a transmittance of 1% or less in a wavelength range of 375 nm or less. It showed shielding properties. Furthermore, the transmittance at a wavelength of 370 nm was 1% or less even at a viewing angle of 60 °. It was a laminated film suitable for a colorless and transparent polarizer protective film having no in-plane color unevenness without bleeding out at all. The product of the film thickness and the UV absorber concentration was 0.14. Table 2 shows the evaluation results of the laminated film obtained.

[Examples 6 to 9]
As shown in Table 2, Examples 6 to 9 are the same as the resin types A-1 and B-1 of the A layer and the B layer, the lamination ratio 1, the number of laminations 251 and the concentration of the UV absorber 1% by weight. Thus, a laminated film was obtained by changing only the number of UV absorber addition layers and the number of UV absorbers. The evaluation results are shown in Table 2. From the viewpoint of bleed out, Example 9 in which the UV absorber was added only to the surface layer A side was inferior to the others. In Example 7 where the reflectance at a wavelength of 402 nm was 72%, a purple reflected color was partially visible in the plane in the in-plane color unevenness evaluation. Example 6 and Example 8 were most balanced in terms of UV shielding and bleed out suppression.

[Example 10]
A laminated film was obtained in the same manner as in Example 7 except that the lamination ratio was changed to 0.5. The rainbow unevenness evaluation is also good because of the low phase difference, and both UV shielding and bleed-out suppression are compatible. The evaluation results are shown in Table 2.

[Examples 11 to 14]
In Examples 11 to 14, using the same laminating apparatus as in Example 10, as shown in Table 3, the thermoplastic resin A, the thermoplastic resin B, the lamination ratio, and the addition layer were changed to obtain laminated films. . The thermoplastic resin A-2 of Example 11 was extruded at an extrusion temperature of 300 ° C., and the thermoplastic resin B-2 was extruded at an extrusion temperature of 290 ° C. The thermoplastic resin A-2 has a resin-derived absorption characteristic from a wavelength of 400 nm or less. The extruded unstretched film is subjected to sequential biaxial stretching 3.2 times at a longitudinal stretching temperature of 145 ° C. and 3.5 times at a transverse stretching temperature of 155 ° C., and the surfaces of the A layer and the B layer after heat treatment at 230 ° C. The difference in internal refractive index was 0.18, which was a laminated film having a great effect of interference reflection and excellent in UV shielding properties. On the other hand, the extrusion temperature of the thermoplastic resin A-2 is 300 ° C. or higher in spite of the reduced amount of the A1 UV absorber added, so that the bleed out is inferior to that of Example 1. It was. Further, since the maximum reflectance is 85% at a wavelength of 405 nm, in-plane color unevenness, which is a purple reflection color, was slightly confirmed. In the rainbow unevenness evaluation, which is a transmitted light evaluation, a slight coloring was observed. Moreover, because of the in-plane orientation peculiar to PEN, the thickness retardation was high. The half width of the reflection peak was 29 nm.

In Example 12, a laminated film was obtained in the same manner as in Example 10 except that the thermoplastic resin A-1 and the thermoplastic resin B-2 were further changed to a lamination ratio of 1. It was excellent in UV shielding without bleeding out. The UV shielding property at an incident angle of light of 60 ° and the rainbow unevenness evaluation were inferior to those of Example 3 and were at a satisfactory level.

In Examples 13 and 14, a thermoplastic film B-3 was used, the addition layer of the UV absorber was only B layer, and the laminated film was formed in the same manner as in Example 10 except that the UV absorber and the lamination ratio were changed. Obtained. In Example 13, although an increase in haze was confirmed due to the molecular weight of the UV absorber C, it was a level with no problem as a bleed-out. In Example 14, a laminated film was obtained in the same manner as in Example 6 except that the thermoplastic resin B-3 was used. Since the UV absorber was added only to the B layer, there was no problem with bleeding out. In addition, since reflection was observed at a wavelength of 395 nm, in-plane unevenness that was a purple reflection color was slightly confirmed.

In Examples 11 to 14, although the UV shielding property was affected by the change of the thermoplastic resin B, the results were satisfactory without bleeding out.

[Examples 15 to 18]
In Examples 15 to 18, laminated films were produced under the same conditions except for the laminated structure, and the relationship between the UV reflecting wall and the UV light shielding property was examined.

Example 15 obtained laminated films under the same conditions as in Example 6 described in Table 3 except that the concentration of the UV absorber in the B layer was reduced to 1.5% by weight. The laminated structure of the obtained laminated film was a two-stage inclined structure described in FIG. 3B, and two UV light reflecting walls were present at different positions in the film thickness. The product of film thickness and UV absorber concentration was very low at 0.09 and there was no bleed out. The long-wavelength absorption edge of the UV absorber is the long-wavelength end 380 nm of the reflection band due to interference reflection based on the layered structure of the layer. The effect was exhibited and the UV shielding property was excellent. This is because, as described in FIG. 4B, the two inclined structures serve as reflecting walls that reflect the UV light, and the absorption efficiency of the UV light is improved. From the above, it was a laminated film suitable for a colorless and transparent polarizer protective film without in-plane color unevenness.

In Example 16, a 201-layer laminated film was obtained in the same manner as in Example 15 except that the laminating apparatus was changed. A laminating apparatus in which the slit length was adjusted so that the layer thickness monotonously changed from one surface of the film to the opposite surface was used. By adopting a slit design in which the gradient, which is the ratio of maximum layer thickness / minimum thickness, is 1.25, a 201-layer laminating apparatus using only the slit plate 72 of the laminating apparatus 7 in FIG. Each of the B layers was a laminated film having one inclined structure. The obtained layer thickness distribution was a laminated structure that monotonously changed from the surface layer to a layer thickness of 40 nm to 60 nm. The transmittance at a wavelength of 370 nm was about 4%, which was inferior in terms of UV light shielding properties compared to Example 15. The half width of the reflection peak was 29 nm.

In Example 17, a 251 layer laminated film was obtained in the same manner as in Example 15 except that the laminating apparatus was changed. The slit length and the gap were adjusted so that the layer thickness distribution as shown in FIG. 3A was obtained, and a single-layer laminating apparatus using only the slit plate 72 in the laminating apparatus 7 of FIG. 2 was obtained. For each of the A layer and the B layer, a laminated film having three inclined structures as shown in FIG. There was no bleed out and the UV light shielding property was excellent. The reason is that as shown in FIG. 4A, the three inclined structures serve as reflecting walls that reflect the UV light, and the absorption efficiency of the UV light is improved. From the above, it was a laminated film suitable for a colorless and transparent polarizer protective film without in-plane color unevenness.

In Example 18, the slit length and the gap were adjusted so that the layer thickness distribution was W-shaped, and a single-layer laminating apparatus using only the slit plate 72 of the laminating apparatus 7 in FIG. A laminated film having four inclined structures was formed for each of the A layer and the B layer. There was no bleed out and the UV light shielding property was excellent. From the above, it was a laminated film suitable for a colorless and transparent polarizer protective film without in-plane color unevenness.

[Examples 19 to 24]
Examples 19 to 24 employ a slit design in which the gradient that is the ratio of the maximum layer thickness / minimum thickness is 1.4, and the slit length, the layer thickness distribution as shown in FIG. The gap was adjusted, and an unstretched film was obtained using a two-layer laminating apparatus using the slit plate 71 and the slit plate 73 in the laminating apparatus 7 of FIG. The types and added layers of the UV absorber used are as described in Table 4. The unstretched film was stretched 3.4 times in the longitudinal direction of the film at 100 ° C. with a longitudinal stretching machine, subjected to corona treatment, and a primer coat was applied to both sides with a # 4 metabar. Next, after guiding both ends to a tenter gripped with clips, the film was transversely stretched 3.5 times in the film width direction at 110 ° C., and then heat-treated at 210 ° C., and relaxed in the film width direction of about 1% at 150 ° C. This was carried out to obtain a laminated film.

The layer thickness distribution of the obtained laminated film includes two inclined structures for each of the A layer and the B layer, and the layer thicknesses of the A layer and the B layer are asymptotically from the surface layer side to the center in the thickness direction. It had an increasing slope structure. The average layer thickness distribution of the adjacent A layer and B layer was a convex layer thickness distribution in which both surface layer portions were 43 nm and the central portion 60 nm was an asymptote. The obtained laminated film had an overall thickness of 30 to 35 μm having two inclined structures. Moreover, it was layer thickness distribution reflecting more than the absorption edge wavelength 310nm derived from the resin of polyethylene terephthalate. Theoretically, it is a laminated film that reflects a wavelength of 280 to 390 nm. Here, the effect by having many layers which reflect UV light was confirmed. On the other hand, the UV absorber addition concentration is lower than in Examples 1 to 18, but the absolute amount is large because the thickness is thick, and the product of the film thickness and the UV absorber concentration exceeds 0.2. is there. In addition, the thickness of both surface layers of a film was 2.3 micrometers, and the thickness of the intermediate | middle layer of the center part of the film thickness direction was 2 micrometers.

Extrusion conditions in Example 19 were the same as in Example 1, and then measured with a gear pump so that the discharge ratio (lamination ratio) was thermoplastic resin A / thermoplastic resin B = 1.15 / 1. A laminated film having a thickness of 35 μm was obtained by alternately stacking 551 layers in the thickness direction by a 551 layer laminating apparatus based on the same principle as the laminating apparatus described in No. 4552936. Other conditions are as described in Table 4. The obtained laminated film had a UV absorber concentration of 0.74% by weight, and the maximum relative reflectance by a spectrophotometer was 70% at a wavelength of 320 nm, and then a reflectance of 63% at a wavelength of 385 nm. In both cases, the full width at half maximum was 15 nm or less. In addition, a good UV shielding property with a transmittance of 1% or less was exhibited in a wavelength range of 380 nm or less. UV absorber B1 has a high molecular weight, the additive layer is not a surface layer, and the extrusion temperature of the additive layer is as low as 265 ° C. It was a laminated film. The product of the film thickness and the UV absorber concentration was 0.26. Table 4 shows the evaluation results of the laminated film obtained.

On the other hand, the extrusion conditions of Example 24 were as follows. The extrusion temperature of the thermoplastic resin A-1 and the thermoplastic resin B-2 was 280 ° C., and the discharge ratio (lamination ratio) with the gear pump was thermoplastic resin A / thermoplastic resin B. The same 551-layer laminated film was obtained in the same manner as in Example 19 while weighing so that = 0.9 / 1. Other conditions are as described in Table 4. The resulting laminated film had a UV absorber concentration of 0.85% by weight, a maximum relative reflectance by a spectrophotometer of 74% at a wavelength of 397 nm, and a half-value width of the reflection peak of about 25 nm. The product of the film thickness and the UV absorber concentration was 0.35. Since the UV absorber was added to the outermost layer A, a slight bleed out was observed during the film forming process. In addition, a good UV shielding property with a transmittance of 1% or less was exhibited in a wavelength range of 380 nm or less. Since the reflection band is slightly visible, in-plane color unevenness is slightly seen, but it was a laminated film suitable for a polarizer protective film. Table 4 shows the evaluation results of the laminated film obtained.

In Examples 20 to 23, the extrusion conditions were the same as in Example 1, and then measured with a gear pump so that the discharge ratio (lamination ratio) was thermoplastic resin A / thermoplastic resin B = 1.27 / 1. However, a laminated film having a thickness of 30 μm was obtained by alternately laminating 491 layers in the thickness direction by a 491 layer laminating apparatus on the same principle as the laminating apparatus described in Japanese Patent No. 4552936. Other conditions are as described in Table 4.

In Example 20, since the molecular weight of the UV absorber was high, there was no bleed out even in the outermost layer side, and the UV shielding property was good. On the other hand, since reflection was seen in the visible light region, in-plane color unevenness was observed. In Example 21, compared with Example 20, the amount of UV absorber added was large and the molecular weight was also small, so a slight bleed out was observed. Other performance was good. In Example 22, as in Example 20, since the molecular weight of the UV absorber was large, no bleed out was observed. On the other hand, the UV shielding property at an incident angle of 60 ° was slightly inferior. In Example 23, although the molecular weight of the UV absorber was lower than that in Example 20, the bleed-out was suppressed because the additive layer was a B layer and the thickness of the outermost layer was 2.5 μm. Other performance was also good. These were laminated films suitable for the polarizer protective film. Table 4 shows the evaluation results of the laminated film obtained.

[Example 25]
Example 25 was a laminated body in which 271 layers were alternately laminated in the thickness direction by a 271 layer laminating apparatus on the same principle as the laminating apparatus described in Japanese Patent No. 4552936. Note that 4 wt% of the UV absorber B1 was added to the thermoplastic resin B-1. A slit design in which the gradient that is the ratio of maximum layer thickness / minimum thickness is 1.23 is adopted, and the slit length and gap are adjusted so that the layer thickness distribution as shown in FIG. Of the laminating apparatus 7, an unstretched film was obtained using a laminating apparatus having a single sheet configuration using only the slit plate 72. The types and added layers of the UV absorber used are as described in Table 4. This unstretched film was stretched 3.3 times in the longitudinal direction of the film at 100 ° C. with a longitudinal stretching machine, subjected to corona treatment, and a primer coat was applied to both sides with a # 4 metabar. Next, after guiding the both ends to a tenter gripped with clips at a temperature of 110 ° C. and 3.5 times in the film width direction, heat treatment at 200 ° C. is performed, followed by relaxation treatment at 150 ° C. in the film width direction of about 2%. This was carried out to obtain a laminated film. Despite the high UVA addition concentration, the addition of the high molecular weight and the B layer was effective, and a laminated film was obtained without breaking on the film formation.

The layer thickness distribution of the obtained laminated film includes two inclined structures for each of the A layer and the B layer, and the layer thicknesses of the A layer and the B layer are asymptotically from the surface layer side to the center in the thickness direction. It had an increasing slope structure. The average layer thickness distribution of the adjacent A layer and B layer was a convex layer thickness distribution in which both surface layer portions were 43 nm and the central portion 58 nm was an asymptotic line. The obtained laminated film had an overall thickness of 14.5 μm having two inclined structures. Although some bleed out was observed, other performance was good. These were laminated films suitable for the polarizer protective film. Table 4 shows the evaluation results of the laminated film obtained.

[Comparative Examples 1 to 3]
A laminated film having a thickness of 30 μm was obtained in the same manner as in Example 21 except that the type and addition concentration of the UV absorber were changed. Since the product of the film thickness and the UV absorber concentration all exceeded 0.35, the problem of bleed out occurred. Further, except for Comparative Example 3, Comparative Example 1 and Comparative Example 2 were slightly inferior to Example 21 in terms of UV shielding properties and coloring at an incident angle of 60 °. These were not laminated films suitable as a polarizer protective film. The evaluation result of the laminated film obtained in Table 5 is shown.

[Comparative Examples 4 to 5]
In Comparative Example 4, the same kind of laminated film was obtained except that the thermoplastic resin B of Example 20 and the extrusion temperature thereof were changed to 280 ° C., and the addition concentration of the UV absorber and the total thickness were 15 μm. . Since the obtained film had no synergistic effect of interference reflection, the UV shielding property was insufficient, and it was not a laminated film suitable as a polarizer protective film. Since the laminated film was substantially a single film, the UV absorber was liable to precipitate and was inferior to the multilayer film.

On the other hand, in Comparative Example 5, a laminated film was obtained in the same manner except that the addition concentration and the overall thickness of the UV absorber of Example 20 were changed. The obtained laminated film had a layer thickness structure in which interference reflection did not occur at a wavelength of 310 to 380 nm which is a wavelength band of UV light. From the results of cross-sectional TEM observation, the maximum layer thickness was very thin, less than 30 nm. Since there was no synergistic effect of interference reflection and UV absorber, UV shielding was insufficient. It was not a laminated film suitable as a polarizer protective film. The evaluation result of the laminated film obtained in Table 5 is shown.

[Comparative Example 6]
Thermoplastic resin A-1 and thermoplastic resin B-1 were put into two twin-screw vent extruders, extruded at temperatures of 280 ° C and 270 ° C, respectively, and three-layer (A / B / A) pinole was The three-layer laminate was discharged from the T-die into a sheet and cooled and solidified with a cast drum to obtain an unstretched film. The types and added layers of the UV absorber used are as described in Table 5. Film formation was performed in the same manner as Example 25 to obtain a laminated film having a thickness of 15 μm.
Since the concentration of the UV absorber added was high, bleeding occurred, the film was frequently broken, and stable film formation could not be achieved. Moreover, uniform stretching was difficult and the retardation unevenness was severe. The UV shielding property was also inferior to that of Example 25, and was an inappropriate film as a polarizer protective film.

[Example 26]
(Laminated film production)
After the resin A-1 as the thermoplastic resin A is vacuum-dried at 180 ° C. for 3 hours, the resin B-5 as the thermoplastic resin B is dried under a vacuum at 150 ° C. Then, each was put into a single screw extruder and a twin screw extruder, melted at an extrusion temperature of 280 ° C., and kneaded. A nitrogen purge was performed on the lower part of the hopper. Subsequently, foreign matters such as oligomers and impurities were removed by vacuum venting at a vacuum pressure of 0.1 kPa or less at two vent holes of the twin screw extruder. Moreover, Q / Ns which is the ratio of the feedstock to the twin screw extruder and the screw rotation speed was set to 1.5. After passing through 10 FSS type leaf disk filters each with a filtration accuracy of 6 μm, and measuring with a gear pump so that the discharge ratio (lamination ratio) is thermoplastic resin A / thermoplastic resin B = 1/1, Based on the same principle as the laminating apparatus described in Japanese Patent No. 4552936, a 251 layer laminating apparatus was used to laminate 251 layers alternately in the thickness direction. In addition, 0.4% by weight of Dye E was added to the thermoplastic resin B-5. Further, a laminated film having a thickness of 16 μm was obtained in the same manner as in Example 1 so as to obtain an upwardly convex layer thickness distribution. It is a laminated film in which 0.04% of aggregated silica particles having an average particle diameter of 2.5 μm are added to the A layer without performing coating treatment.

The layer thickness distribution of the obtained laminated film includes two inclined structures for each of the A layer and the B layer, and the layer thicknesses of both the A layer and the B layer from the surface layer side to the 125th layer in the center in the thickness direction. Had an inclined structure that increased asymptotically. The average layer thickness distribution of the adjacent A layer and B layer had a convex layer thickness distribution in which the average layer thickness of 70 nm was an asymptotic line. The resulting laminated film has a pigment concentration of 0.2% by weight, a maximum value of relative reflectance by a spectrophotometer of 32%, a transmittance at a wavelength of 460 nm of 62%, and good blue light cut performance. Was showing. The molecular weight of the dye E was high, the additive layer did not appear on the surface layer, bleed out, and was a laminated film suitable for a blue light cut film having no in-plane color unevenness. The product of the film thickness 15 (μm) and the pigment concentration 0.2 was 0.03. In addition, the rainbow unevenness has no problem because it shows blue as the reflection color. Table 6 shows the evaluation results of the laminated film obtained.

[Examples 27 to 28]
(Laminated film production)
After the resin A-1 as the thermoplastic resin A is vacuum-dried at 180 ° C. for 3 hours, the resin B-5 as the thermoplastic resin B is dried under nitrogen at 150 ° C. Then, each was put into a single screw extruder and a twin screw extruder, melted at an extrusion temperature of 280 ° C., and kneaded. A nitrogen purge was performed on the lower part of the hopper. Subsequently, foreign matters such as oligomers and impurities were removed by vacuum venting at a vacuum pressure of 0.1 kPa or less at two vent holes of the twin screw extruder. Moreover, Q / Ns which is the ratio of the feedstock to the twin screw extruder and the screw rotation speed was set to 1.5. After passing through 10 FSS type leaf disk filters each with a filtration accuracy of 6 μm, and measuring with a gear pump so that the discharge ratio (lamination ratio) is thermoplastic resin A / thermoplastic resin B = 1/1, Based on the same principle as the laminating apparatus described in Japanese Patent No. 4552936, a 551 layer laminating apparatus was used to laminate 551 layers alternately in the thickness direction. Note that 0.2% by weight of Dye E was added to the thermoplastic resin B-5. Further, a laminated film having a thickness of 40 μm was obtained in the same manner as in Example 1 so as to obtain an upwardly convex layer thickness distribution. It is a laminated film in which 0.04% of aggregated silica particles having an average particle diameter of 2.5 μm are added to the A layer without performing coating treatment.

The layer thickness distribution of the obtained laminated film includes two inclined structures for each of the A layer and the B layer, and the layer thicknesses of both the A layer and the B layer from the surface layer side to the 125th layer in the center in the thickness direction. Had an inclined structure that increased asymptotically. The average layer thickness distribution of the adjacent A layer and B layer had a convex layer thickness distribution in which the average layer thickness of 70 nm was an asymptotic line. The resulting laminated film has a pigment concentration of 0.1% by weight, a maximum relative reflectance by a spectrophotometer of 42%, a transmittance at a wavelength of 460 nm of 55%, and good blue light cutting properties. Was showing. The molecular weight of the dye E was high, the additive layer did not appear on the surface layer, bleed out, and was a laminated film suitable for a blue light cut film having no in-plane color unevenness. The product of the film thickness 40 (μm) and the pigment concentration 0.1 was 0.04. In addition, the rainbow unevenness has no problem because it shows blue as the reflection color. Table 6 shows the evaluation results of the laminated film obtained.

Example 28 obtained a laminated film in the same manner as in Example 26 except that the thermoplastic resin B was changed. In addition, the rainbow unevenness has no problem because it shows blue as the reflection color. Table 6 shows the evaluation results of the laminated film obtained.

[Comparative Examples 7 to 9]
In Comparative Example 7, a laminated film was obtained in the same manner as in Example 27 except that no pigment was added. Table 6 shows the evaluation results of the laminated film obtained. On the other hand, in Comparative Examples 6 to 7, a laminated film having a thickness of 15 μm was obtained by the same method except that the laminating apparatus was changed to a 491-layer laminating apparatus and the dye was changed to a monoazo benzenesulfonate.

Comparative Examples 8 to 9 obtained the same type of laminated film in the same manner as in Example 5 except that the contents described in Table 6 were changed. Since it was a laminated film of the same kind of PET, there was no shielding effect of the UV absorber due to the layer interface, and any of these did not bleed out and were not suitable blue light cut films.

[Example 29]
The main orientation axis of the laminated film obtained in Example 6 was pasted on a liquid crystal display using a 42-inch LED backlight liquid crystal panel manufactured by TCL in VA mode as the film width direction. At this time, the narrow angle of the angle between the main orientation axis of the laminated film and the in-plane orientation of linearly polarized light by the polarizer of the upper polarizing plate of the liquid crystal display was 0 °. In addition, if the narrow angle is 10 ° or less, when the white display is confirmed with the polarized sunglasses, the display is black, and there is no change before and after the bonding, and it is confirmed that it can be used well even if it is replaced with the conventional triacetylcellulose. .

[Example 30]
Subsequently, using a liquid crystal panel of ipad6 LED backlight manufactured by Apple in IPS mode, the laminated film obtained in Example 10 was pasted as a front polarizer of the upper polarizing plate, and brightness was obtained during both white display and extinction. It was confirmed that the film was suitable as a polarizer protective film for liquid crystal displays without problems such as color unevenness. In particular, when the direction of the linearly polarized light from the panel and the angle formed by the laminated film was set to 20 to 70 °, black display did not occur when wearing polarized sunglasses.

[Example 31]
Using the laminated film of Example 6, as in Example 29, the angle of the narrow angle among the angles formed with the in-plane orientation of linearly polarized light by the polarizer of the upper polarizing plate of the liquid crystal display is 45 degrees. Arranged. When white display was confirmed with polarized sunglasses, it was confirmed that the liquid crystal display was suitable because it did not display black at all azimuth angles.

[Example 32]
The laminated film obtained in Example 26 was pasted on iPhone 5s manufactured by Apple, and it was confirmed that the film was a screen protective film having a blue light cut property independent of the viewing angle.

[Example 33]
A laminated film was obtained in the same manner as in Example 6 except that the UV absorber of Example 6 was changed to a two-component system in which the mixing ratio of A1 and B1 was blended at a ratio of 6: 4. The evaluation results are shown in Table 4. Due to the effect of A1, there was almost no bleed-out, the reflectance at a wavelength of 339 nm was 49%, and in the evaluation of in-plane color unevenness, it was confirmed that it was colorless and had no problem. There was a balance between UV shielding and bleed-out suppression.

[Example 34]
The resin A-1 in Example 6 was changed to a resin having a UV absorber concentration of 3 wt% in the resin A-3, and the resin was put into a twin screw vent extruder. Otherwise, a laminated film was obtained in the same manner as in Example 6. The evaluation results are shown in Table 4. Despite the presence of the UVA absorbing component on the A layer side, it was a copolymer, so there was no bleeding out and the reflectance at a wavelength of 405 nm was 65%. In the transmitted color, a yellow tendency was observed, but it was confirmed that there was no particular problem. There was a balance between UV shielding and bleed-out suppression.

[Example 35]
The resin A-1 was diluted with the resin A-1 so that the concentration of the UV absorber component of the resin A-1 to the resin A-4 in Example 6 was 3% by weight, and charged into a twin screw vent extruder. Otherwise, a laminated film was obtained in the same manner as in Example 6. The evaluation results are shown in Table 4. Despite the presence of UVA absorbing component on the A layer side, it is a copolymer, so there is no bleed out, the reflectance at a wavelength of 320 nm is 49%, and in-plane color unevenness evaluation is colorless and has no problem. I was able to confirm that. There was a balance between UV shielding and bleed-out suppression.

[Example 36]
In Example 36, the thermoplastic resin A-5 was added to the A layer, and the UV absorber A1 was added to the thermoplastic resin B-3 to the B layer, and each was extruded with a biaxial vent extruder. Next, on the same principle as the laminating apparatus described in Japanese Patent No. 4552936, a laminated body was obtained in which 151 slit layers were alternately laminated in the thickness direction by a laminating apparatus having one sheet. The average layer thickness was 40 to 58 nm, which was a layer thickness distribution of two inclined structures. Subsequent film forming conditions were the same as in Example 11 to obtain a laminated film. Despite being as thin as 7.5 μm, no bleed-out was observed and other performances were good. These were laminated films suitable for the polarizer protective film. Table 4 shows the evaluation results of the laminated film obtained. Although a small amount of UVA was added to the B layer side, it was confirmed that it was colorless and had no problem. Rainbow unevenness was also suppressed, and it was excellent in terms of UV shielding and bleed out suppression. The product of the film thickness and the UV absorber concentration was 0.04. The half width was 20 nm.

Although the present invention can provide a laminated film excellent in blue light and UV shielding properties without bleed-out of dyes and UV absorbers and film breakage despite being a very thin film, It can be suitably used for process films for information communication equipment such as personal computers, smartphones, tablets, polarizer protection for polarizing plates for LCD and OLED, retardation films, circularly polarizing films, and screen protective films. It can also be used in the manufacturing process of electronic paper and semiconductor resist. Moreover, it is suitable as a laminated film used for packaging materials for automobiles, building material window films, agricultural houses, makeup, foods, medicines, medical treatments and the like.

1: Layer made of thermoplastic resin A (A layer)
2: Layer made of thermoplastic resin B (B layer)
3: Incident light 4: Reflected light 5: Laminated film 6: UV absorber 7: Laminating device 71: Slit plate 72: Slit plate 73: Slit plate 8: Merger 9: Connecting pipe 10: Base 11: By slit plate 71 Inclined structure 12 with layer thickness formed: Inclined structure 13 with layer thickness formed by slit plate 72: Inclined structure 11 L with layer thickness formed by slit plate 73: Resin flow path 12L from the outlet of slit plate 71 : Resin flow path 13L from the outlet of the slit plate 72: resin flow path 11M from the outlet of the slit plate 73: resin flow path 12M communicating with the outlet of the slit plate 71 and disposed by the recombiner: slit Resin flow path 13M communicated with the flow outlet of the plate 72 and disposed by the merger: Resin flow path communicated with the flow outlet of the slit plate 73 and disposed by the merger 4: Length in the width direction of the resin channel 15: Length in the film width direction at the inlet of the die 16: Cross section of the channel at the inlet of the die 17: Length in the film width direction of the die lip 18: Layer Or the order of layer pairs (layer number or layer pair number)
19: Layer thickness 20: Upper limit of average layer thickness (maximum average layer thickness)
21: Average layer thickness distribution 22: Average layer thickness that reflects UV light 23: Reflection 24: Hard coat 25: Adhesive 26: Cover glass 27: Electronic equipment casing 28: PVA polarizer 29: Polarizer protective film 30: Polarizing plate 31: Liquid crystal layer 32: Upper polarizing plate 33: Lower polarizing plate 34: Linear polarization direction (transmission direction) of PVA polarizer
35: Main orientation axis of laminated film 36: Orientation angle 37: Cover glass 38: Conductive layer 39: Ordinary polarizing plate 80 of TAC / PVA / TAC configuration: Spectral reflection spectrum of laminated film that interferes and reflects UV to blue light Simulation result 81: Spectral transmission spectrum of a monolayer film containing a dye of an anthraquinone pigment that absorbs blue light in cyclohexanedimethanol copolymerized polyethylene terephthalate 82: Long wavelength end 83 of reflection band due to interference reflection: Long wavelength absorption end 84: Reflection region 85 disappearing due to absorption characteristics of pigments, etc .: Transmission region 86 disappearing due to original interference reflection spectrum: Reflection peak on long wavelength side 87: Reflection peak on short wavelength side

Claims

A laminated film in which at least 50 layers of a layer made of thermoplastic resin A (A layer) and a layer made of thermoplastic resin B (B layer) are alternately laminated, and at least one of layer A or layer B Contains a dye or UV absorber that absorbs blue light, or both, and the product of the film thickness and the concentration of the dye or UV absorber that absorbs blue light or both is 0.35 [μm · weight % / 100] or less, and the concentration of the blue light absorbing dye and / or UV absorber, or both, is 0.1 to 3% by weight, and the maximum reflectance is 15% at a wavelength of 300 nm to 500 nm. A laminated film having a minimum transmittance of 70% or less.
A layer (A layer) composed of a thermoplastic resin A that has an absorption peak wavelength of 300 nm to 500 nm of the dye or UV absorber that absorbs blue light, and reflects at least part of the wavelength range, and a thermoplastic resin The average value of the layer thickness of a set of layer pairs composed of layers consisting of B (B layer) is 40 nm to 80 nm, the layer pairs are blue and UV light reflecting walls, and the reflecting walls are films The laminated film according to claim 1, wherein there are at least two or more at different positions in the thickness direction.
The laminated film according to claim 1 or 2, wherein a long wavelength absorption edge of a dye or UV absorber that absorbs blue light is larger than a long wavelength edge of a reflection band due to interference reflection based on a laminated structure of the layers.
The laminated film according to any one of claims 1 to 3, wherein the B layer has a low refractive index relative to the A layer, and the dye or the UV absorber or both are contained only in the B layer.
The laminated film according to claim 4, wherein the dye or the UV absorber has a molecular weight of 500 or more.
The laminated film according to any one of claims 1 to 5, wherein the total light transmittance is 70% or more and the chromaticity b * value in the transmission mode is 5 or less.
The laminated film according to any one of claims 1 to 6, wherein an absorption coefficient of an absorption peak of the dye or UV absorber in the wavelength range of 300 nm to 500 nm is 0.06 [wt% · µm] -1 or more.
The laminated film according to any one of claims 1 to 7, wherein the transmittance at a wavelength of 370 nm is 5% or less.
The laminated film according to any one of claims 1 to 8, which has a retardation of 4000 nm to 20000 nm, or 1 nm to 400 nm.
The average value of the layer thicknesses of the layer pairs of the adjacent A layer and B layer is the average layer thickness, and the average layer thickness distribution obtained from the relationship between the number of all layer pairs of the laminated film and the average layer thickness is two or more. The laminated film according to any one of claims 1 to 9, wherein the number of layer pairs having an inclined structure and an average layer thickness of 40 nm or more and 60 nm or less is 80% or more of the total number of layer pairs.
The laminated film according to any one of claims 1 to 10, wherein the half width of the reflection spectrum showing the maximum reflectance in the wavelength range of 300 nm to 500 nm is less than 30 nm.
The laminated film according to any one of claims 1 to 11, wherein the dye or UV absorber that absorbs blue light contains at least two components.
The laminated film according to any one of claims 1 to 12, wherein a photocurable or thermosetting resin layer C is formed on at least one surface.
The laminated film according to any one of claims 1 to 13, comprising a thermoplastic resin copolymerized with a UV absorber.
The laminated film according to any one of claims 1 to 14, which is a polarizer protective film.
A liquid crystal display using the laminated film according to any one of claims 1 to 14.
The narrow angle of the angle between the main alignment axis of the laminated film according to any one of claims 1 to 14 and the in-plane orientation of linearly polarized light by the polarizer of the upper polarizing plate of the liquid crystal display is 20 degrees or more and 70 degrees or less. The liquid crystal display according to claim 16, which is arranged in the relationship of
The angle between the main alignment axis of the laminated film according to any one of claims 1 to 14 and the in-plane orientation of linearly polarized light by the polarizer of the upper polarizing plate of the liquid crystal display is 10 ° or less. The liquid crystal display according to claim 16, which is arranged.
A touch panel using the laminated film according to any one of claims 1 to 14.
An organic EL display using the laminated film according to any one of claims 1 to 14.