JP5235316B2 - Optical laminated film and image display device - Google Patents

Description

  The present invention relates to an optical laminated film, and an image display device such as a liquid crystal display, a plasma display, an organic EL display, or a surface electric field display (SED), and a CRT display using the optical laminated film as constituent members. .

  The purpose is to secure these high quality images as the demand for image display devices such as liquid crystal display (LCD), plasma display (PDP), organic EL display, surface electric field display (SED), or CRT display increases. As a result, the demand for optical films as main constituent members has been increasing rapidly. The optical film is a film having various optical functions for preventing reflection of external light, widening the viewing angle, correcting optical unevenness, and the like.

  As the optical film, a multilayer film having a multilayer structure including a support body serving as an axis of the optical film and an upper layer provided so as to be in contact therewith is mainly used. In general, a transparent film mainly composed of a polymer is used as the support. Among them, a support made of a polyester resin is increasing in demand because it has characteristics such as excellent transparency, dimensional stability, chemical resistance, and low hygroscopicity. Further, the upper layer is a layer containing a polymer as a main component and additives for imparting various optical functions such as for the purpose of preventing the reflection of the laminated film. For example, the antireflection layer, the prism layer, the light Examples include a diffusion layer. By appropriately selecting the combination of the support and the upper layer, for example, prism films, antireflection films, light diffusion films used for LCDs, etc., IR absorption films, electromagnetic wave shielding films, and toning films used for PDPs Various optical films such as an antireflection film, an antiglare film, and a hard coat film can be freely formed.

  However, if the adhesive strength at the interface between the support and the upper layer is low, peeling occurs between the upper layer and the support, causing problems such as light leakage and inability to prevent light reflection. Therefore, in optical laminated films, the high adhesive strength at the interface is important, but the adhesive strength at the interface affects the material composition of the support and the upper layer, the unevenness of the contact surface, the formation conditions of each layer, etc. Since it is easy to receive, it is difficult to control it to a desired value. Therefore, for example, Patent Document 1 proposes an optical laminated film in which a polyester film is used as a support, and an easy-adhesion layer containing polyester is provided on the support to improve the adhesive strength at the interface. Yes.

  In addition, since the optical laminated film is composed of a plurality of members having different refractive indexes, such as a support, an easy-adhesion layer, and an upper layer, light reflection is likely to occur at each interface. Further, when light is reflected at each interface, the reflected light interferes with each other and rainbow-colored interference unevenness (rainbow unevenness) occurs, so that the display quality of the optical laminated film is significantly deteriorated. At present, the support made of polyester resin, which is mainly used, has a refractive index of about 1.65, which is a relatively high value. In view of this, a method of reducing the refractive index difference between the support and the adjacent layer by increasing the refractive index of the adjacent layer has been studied. For example, Patent Document 2 proposes a laminated film having an easy-adhesion layer that contains fine particles of a predetermined metal oxide and has a high refractive index, and Patent Document 3 discloses a support made of polyester. A laminated film in which a water-based coating layer made of a water-soluble titanium chelate compound and a water-based polyester resin and a hard coat layer are provided has been proposed. Furthermore, Patent Document 4 proposes a laminated film having an easy-adhesion layer and an upper layer in which the refractive index difference from the support is adjusted by paying attention to the refractive index of the polymer.

The rainbow unevenness is also caused by the thickness unevenness of each layer. In particular, the presence of uneven thickness in the upper layer is a problem because the reflected light intensity increases at a specific thickness and a large amount of rainbow unevenness occurs. On the other hand, Patent Document 5 proposes a method of suppressing the occurrence of rainbow unevenness by manufacturing a film while controlling the refractive index and film thickness of the easy-adhesion layer. Further, Patent Document 6 proposes a laminated film having a primer layer having a high refractive index by adding inorganic fine particles mainly composed of titanium dioxide on at least one surface of a transparent support.
JP 2001-294826 A JP 2004-054161 A JP 2005-097571 A JP 2000-111706 A Japanese Patent Laid-Open No. 2003-177209 JP 2005-178173 A

  In any of the above, fine particles, a chelate compound, and the like are added to the easy adhesion layer for the purpose of preventing rainbow unevenness. However, in this case, there is a problem that fine particles, a chelate compound, and the like are deposited on each interface between the support / the easy-adhesion layer or the easy-adhesion layer / the upper layer, and the adhesive strength is lowered. Furthermore, when a large amount of fine particles are contained for the purpose of increasing the refractive index, the strength of the layer is lowered, and the strength of the entire film is reduced in a chain. In Patent Document 5, a method of adjusting the refractive index of the easy-adhesion layer by appropriately selecting and using a polymer having a desired refractive index is used, but such a polymer is expensive. Therefore, there is a problem that the manufacturing cost is increased.

  Accordingly, a first object of the present invention is to provide a laminated film which is a film in which the occurrence of rainbow unevenness is suppressed and which is excellent in various optical properties such as antireflection. Furthermore, a second object is to provide an image display device that exhibits excellent display quality by using this optical laminated film.

The present invention comprises a support made of polyester, and a first easy-adhesion layer, a second easy-adhesion layer, and a surface layer that are sequentially arranged on at least one surface of the support, and the refractive index of the support Is η1, the refractive index of the first easy-adhesive layer is η2, the refractive index of the second easy-adhesive layer is η3, and the refractive index of the surface layer is η4, (η1 / η4) ^1/2 × 0.95 ≦ η2 / η3 ≦ (η1 / η4) ^1/2 × 1.05 is satisfied, the surface layer is a hard coat layer, and the refractive indexes η1, η2, η3, and η4 of each layer are η1 <η4, and η2 <Η3, and in the range of λ which is the wavelength of visible light 550 nm ≦ λ ≦ 600 nm, d1 (nm) which is the film thickness of the first easy-adhesion layer and η2 are −30 ≦ d1- {λ / (4 × η2)} ≦ 30, d2 (nm) being the film thickness of the second easy adhesion layer and η3 satisfy −30 ≦ d2− {λ / (4 × η3)} ≦ 30. It is characterized by.

It is preferable that the first easy-adhesion layer and the second easy-adhesion layer contain at least one of a polyester resin, a polyurethane resin, and an acrylic resin . Moreover, it is preferable that the said 2nd easily bonding layer contains the microparticles | fine-particles which have any one of a tin oxide, an indium oxide, a zirconium oxide, and a titanium oxide as a main component . Moreover, it is preferable that the said 1st easily bonding layer and / or 2nd easily bonding layer contain the compound which has multiple carbodiimide structures in a molecule | numerator .

The polyester is polyethylene terephthalate, and the refractive index η4 of the hard coat layer is 1.75 or more and 2.0 or less. An antireflection layer is provided on the hard coat layer, and the antireflection layer has a refractive index of 1.50 or less.

  The image display device of the present invention is characterized by having the optical laminated film.

  According to the present invention, on the support made of polyester, each layer has a multilayer structure in which the first easy-adhesion layer, the second easy-adhesion layer, and the surface layer are laminated in order from the side close to the support. An optical laminated film in which the occurrence of rainbow unevenness is suppressed while the adhesive strength between the members is kept high can be obtained. Moreover, the image display apparatus which has the outstanding display quality is obtained by making this laminated film for optics into a structural member.

  In order to reduce the reflectance of the antireflection film, increasing the refractive index of the hard coat layer has become a recent trend. In order to eliminate rainbow unevenness when the refractive index of the hard coat layer is increased, it is necessary to increase the refractive index of the easy-adhesion layer (when the easy-adhesion layer is one layer). In this case, in order to increase the refractive index, the content of metal oxide particles and the like in the easy adhesion layer increases, and the strength of the easy adhesion layer decreases accordingly. In the present invention, since the easy adhesion layer has a two-layer structure, it is possible to prevent rainbow unevenness without increasing the refractive index of each easy adhesion layer. Thereby, the optical laminated film which suppressed generation | occurrence | production of a rainbow nonuniformity, ensuring the adhesive strength of each layer is obtained.

  Hereinafter, the present invention will be described in detail with reference to embodiments. However, the following embodiment is one of preferred examples of application of the present invention, and does not limit the present invention.

  First, an embodiment according to the present invention will be described. As shown in FIG. 1, an optical laminated film (hereinafter simply referred to as a laminated film) 10 of the present invention includes a film-like support 11 formed of a polyester resin and a side closer to the support 11 in order. The first easy-adhesion layer 12, the second easy-adhesion layer 13, the hard coat layer 14 as a surface layer, and the antireflection layer 15 are laminated. In addition, you may provide the 1st easily bonding layer 12 and the 2nd easily bonding layer 13 not only on the single side | surface of the support body 11, but on both surfaces.

  For example, as in the second embodiment shown in FIG. 2, the first easy-adhesion layer 16 and the second easy-adhesion layer 17 are provided on the back surface of the support 11 on the laminated film 10 shown in FIG. When the NIRA (near infrared blocking) coat layer 18 is formed, the NIRA coat layer 18 can be provided on the back surface of the support 11 with good easy adhesion, and such a laminated film 20 is used as an antireflection film for PDP. It can be preferably used.

  FIG. 3 shows the laminated film 20 shown in FIG. 2, in which the first easy-adhesive layer 12 and the second easy-adhesive layer 13 are composed of a single easy-adhesive layer 25, on which a hard coat layer 26 and an antireflection layer are formed. The laminated film 30 as 3rd Embodiment which formed 27 is shown. Such a laminated film 30 can also be suitably used as an antireflection film for PDP.

  1 to 3, the hard coat layer 15 and the NIRA coat layer 18 are described as surface layers, but this surface layer includes not only the final product form but also the intermediate form. Therefore, in the case of the intermediate form, the antireflection layer 15 and other uppermost layers may be formed on the surface layer in the present invention.

  Η1 which is the refractive index of the support 11, η2 which is the refractive index of the first easy-adhesion layer 12, η3 which is the refractive index of the second easy-adhesion layer 13, and the refraction of the hard coat layer 14 which is a surface layer, for example. The rate η4 is η1 <η4 and η2 <η3. In this way, reflection of light at the interface between the hard coat layer 14 and the support 11 is prevented, and the occurrence of rainbow unevenness due to light interference is suppressed. In this invention, the laminated film by which the rainbow nonuniformity in each interface was suppressed can be obtained by adjusting so that the refractive index of adjacent layers may satisfy | fill the said conditions, although it is a multilayer structure. In addition, the refractive indexes η1 to η4 of the layers 11 to 14 include fine particles in the members constituting the layers 11 to 14 while adjusting the type and content, or appropriately select the refractive index of the polymer used as the binder. By doing so, adjustment is possible. A method for measuring the refractive index may be a known method and is not particularly limited. In addition, let refractive index (eta) 1- (eta) 4 of each layer 11-14 which concerns on this invention be a value by the visible light in wavelength 550-600 nm.

Furthermore, η2 / η3 is
(Η1 / η4) ^1/2 × 0.95 ≦ It is preferable that η2 / η3 ≦ (η1 / η4) ^1/2 × 1.05 is satisfied. More preferably,
(Η1 / η4) ^1/2 × 0.97 ≦ η2 / η3 ≦ (η1 / η4) ^1/2 × 1.03
Particularly preferably,
(Η1 / η4) ^1/2 × 0.98 ≦ That is, η2 / η3 ≦ (η1 / η4) ^1/2 × 1.02. Thereby, the reflection in the support body 11 and the hard-coat layer 14 in a laminated film is suppressed, and generation | occurrence | production of the rainbow nonuniformity of a laminated film is suppressed.

In the range where λ which is the wavelength of visible light is 550 nm ≦ λ ≦ 600 nm, d1 (nm) which is the film thickness of the first easy-adhesion layer 12 and the refractive index η2 of the first easy-adhesion layer 12 are −30 ≦ d1− {λ / (4 × η2)} ≦ 30, d2 (nm) being the film thickness of the second easy adhesion layer 13 and the refractive index η3 of the second easy adhesion layer 13 are −30 ≦ d2 It is desirable to satisfy − {λ / (4 × η3)} ≦ 30. More preferably,
−20 ≦ d1− {λ / (4 × η2)} ≦ 20, −20 ≦ d2 {λ / (4 × η3)} ≦ 20
Particularly preferably,
−10 ≦ d1− {λ / (4 × η2)} ≦ 10, −10 ≦ d2 {λ / (4 × η3)} ≦ 10
Is to satisfy. Thus, the laminated film in which the film thickness and the refractive index of the first easy-adhesion layer 12 and the second easy-adhesion layer 13 are adjusted is further prevented from being reflected at the interface, and rainbow unevenness, which is light interference, is generated. Is significantly suppressed.

Among the above, Formula (1) η1 <η4, which is a relationship of η1, η2, η3, η4,
(2) η2 <η3,
(3) (η1 / η4) ^1/2 × 0.95 ≦ η2 / η3 ≦ (η1 / η4) ^1/2 × 1.05
And the numerical formula (4) -30 ≦ d1- {λ / (4 × η2)} ≦ 30 showing the relationship between the refractive index and the film thickness of the first easy-adhesive layer 12 and the second easy-adhesive layer 13;
(5) -30 ≦ d2- {λ / (4 × η3)} ≦ 30
Will be described.

For example, the reflection at the interface between the support 11 and the hard coat layer 14 generally satisfies η2 / η3 = (η1 / η4) ^1/2 , η2 × d1 = λ / 4, and η3 × d2 = λ / 4. It can be prevented. Each of these mathematical expressions is described in general optical textbooks such as “optical thin film” (p. 98, edited by Shiro Fujiwara, Kyoritsu Publishing Co., Ltd., published in 1986). Therefore, when each value constituting the mathematical formula is adjusted to satisfy the formula, the reflectance at the interface is theoretically zero. However, it is difficult to make the reflectance of the layer close to the theoretical value only by changing the material type or adding fine particles. Furthermore, when a laminated film having a multilayer structure as shown in FIG. 1 is produced, the factors become complex, and it becomes even more difficult. However, actually, even if a slight deviation from the above general formula occurs, it was confirmed that reflection at the interface was prevented and the occurrence of rainbow unevenness was suppressed. In the present invention, the allowable range was taken into account. The mathematical formulas (3) to (5) that can be adapted to a laminated film having a multilayer structure are defined above, and further appropriate values are defined. Also, as a recent trend, the refractive index of the hard coat layer is increased in order to reduce the reflectance of the antireflection film. For this reason, it is possible to reduce the reflectance by setting the refractive index of the hard coat layer to η1 <η4 as shown in Equation (1), and η2 <η3 as shown in Equation (2). Thus, rainbow unevenness can be reduced.

[Support]
The polyester used as the support 11 is not particularly limited, and a known polyester can be used. Specific examples include polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, and polybutylene naphthalate. Among these, it is particularly preferable to use polyethylene terephthalate from the viewpoint of cost and mechanical strength.

  The support 11 of the present invention is preferably biaxially stretched. Biaxial stretching refers to stretching in both directions, assuming that the width direction and the longitudinal direction of the support 11 are each uniaxial. Thus, the biaxially stretched support 11 has a very excellent mechanical strength because the biaxial molecular orientation is sufficiently controlled. The draw ratio is not particularly limited, but the draw ratio in one direction is preferably 1.5 to 7 times, more preferably 2 to 5 times. In particular, the support 11 that has been biaxially stretched at a stretch ratio per uniaxial direction of 2 to 5 times has very good mechanical strength because the molecular orientation is controlled more efficiently and effectively. To the support 11. By setting the draw ratio of the support 11 to 1.5 times or more, sufficient mechanical strength can be obtained as compared with the case of less than 1.5 times. Further, by setting the draw ratio to 7 times or less, a uniform thickness can be obtained as compared with the case where the draw ratio exceeds 7 times.

  The thickness of the support 11 is preferably 30 μm or more and 400 μm or less. More preferably, it is 35 μm or more and 350 μm or less. The thickness of the support 11 can be easily adjusted by controlling the draw ratio. Such a support 11 is lightweight and excellent in handleability while having transparency and various optical properties. The support 11 having a thickness of 30 μm or more is not too thin and is easy to handle. Further, the support 11 having a thickness of 400 μm or less has an appropriate thickness, which makes it easy to reduce the size and weight of the image display device, and does not cause an increase in manufacturing cost. The support 11 of the present invention may contain an ultraviolet absorber and an antioxidant. In particular, when used for an antireflection film for PDP, it is preferable to contain an ultraviolet absorber as described in JP-A-2006-212815.

[First easy-adhesive layer, second easy-adhesive layer]
The 1st easily bonding layer 12 and the 2nd easily bonding layer 13 are comprised from the layer containing any one or more of a polyester resin, a polyurethane resin, and an acrylic resin. If necessary for adjusting the refractive index, fine particles mainly containing any one of tin oxide, indium oxide, zirconium oxide, and titanium oxide may be contained. The first easy-adhesion layer 12 is disposed on the support 11 so as to be in contact therewith. Moreover, by providing the 2nd easily bonding layer 13 on the 1st easily bonding layer 12, as described in the said 0023 paragraph, it acts as an antireflection layer.

  The polyester resin is a general term for polymers having an ester bond in the main chain, and is usually obtained by a reaction between a polycarboxylic acid and a polyol. Examples of the polycarboxylic acid include fumaric acid, itaconic acid, adipic acid, sebacic acid, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, and the like. Of these, terephthalic acid and naphthalenedicarboxylic acid are preferably used. A copolymer obtained by copolymerizing sodium sulfoisophthalate or the like is preferable because it can be used as a water-soluble or water-dispersible polyester resin.

  Examples of polyols include ethylene glycol, propylene glycol, 1,4 butanediol, 1,6 hexanediol, glycerin, hexanetriol, neopentyl glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and bisphenol A ethylene oxide addition. Product (NC-1900, manufactured by Nippon Emulsifier Co., Ltd.), polyester polyol and the like. Commercially available products include polyester-based aqueous dispersions Finetex ES650 and ES2200 (trade name: manufactured by Dainippon Ink & Chemicals, Inc.), Bironal MD1400, MD1480 (trade name: manufactured by Toyobo Co., Ltd.), and polyester-based water-soluble products. Examples include plus coats Z-221, Z-561, Z-730, RZ-142 (trade name: manufactured by Kyoyo Chemical Co., Ltd.) and the like, which are functional polymers.

  The polyurethane resin is a general term for polymers having a urethane bond in the main chain, and is usually obtained by a reaction between a polyisocyanate and a polyol. Examples of the polyisocyanate include TDI, MDI, NDI, TODI, HDI, and IPDI. Examples of the polyol include ethylene glycol, propylene glycol, glycerin, and hexanetriol. As the isocyanate of the present invention, a polymer obtained by subjecting a polyurethane polymer obtained by the reaction of polyisocyanate and polyol to a chain extension treatment to increase the molecular weight can also be used. The polyisocyanate, polyol and chain extension treatment described above are described in, for example, “Polyurethane Resin Handbook” (edited by Keiji Iwata, Nikkan Kogyo Shimbun, published in 1987). As commercially available products, Superflex 830, 460, 870, 420, 420NS (trade names: manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), Bondick 1370NS, 1320NS, Hydran AP-40F (trade names: Dainippon Ink & Chemicals, Inc.).

  An acrylic resin is a polymer containing acrylic acid, methacrylic acid and derivatives thereof as components. Examples of such acrylic resins include acrylic acid, methacrylic acid, methyl methacrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, acrylamide, acrylonitrile, hydroxyl acrylate, and the like, and monomers copolymerizable therewith. Examples thereof include a copolymerized polymer. Examples of this monomer include styrene and divinylbenzene. Examples of commercially available products include Jurimer ET325, ET410, SEK301 (trade name: manufactured by Nippon Pure Chemical Co., Ltd.), Boncourt AN117, AN226 (trade name: manufactured by Dainippon Ink & Chemicals, Inc.), which are acrylic water dispersions. Can be mentioned.

  If fine particles are used for the purpose of adjusting the refractive index as described above, the fine particles aggregate to form huge foreign matters, and the light transmittance of the first easy-adhesive layer 12 and the second easy-adhesive layer 13 may be reduced. In this case, aggregation can be suppressed by suitably selecting and using the particle size and type of the fine particles. In order to effectively suppress the aggregation of the fine particles, the average particle size of the fine particles is preferably 5 nm or more and 200 nm or less. More preferably, the average particle size is 10 nm or more and 100 nm or less, and particularly preferably 15 nm or more and 70 nm or less. When fine particles having an average particle diameter of 200 nm or less are used, there is no possibility that the transparency of the first easy-adhesion layer 12 and the second easy-adhesion layer 13 that can be visually confirmed is lowered or the light transmittance is lowered. . Further, by using fine particles having an average particle diameter of 5 nm or more, it is possible to obtain them at a lower price than fine particles having a smaller average particle diameter, which is advantageous in terms of production cost. In addition, since fine particles of 5 nm or more are used, there is less risk of becoming a giant foreign material due to aggregation of the fine particles compared to the case of using fine particles of less than that, and no decrease in transparency is caused. The average particle size of the fine particles in the present invention is the particle size obtained for any 50 fine particles when the fine particles taken with a scanning electron microscope are taken as the diameter of a circle having the same area. The average value of

  As the fine particles used for the first easy-adhesive layer 12 and the second easy-adhesive layer 13, among the fine particles listed above, tin oxide, zirconium oxide, It is preferable to use titanium oxide.

As the tin oxide, tin (IV) oxide having a SnO ₂ composition is preferable. Further, it is preferable to use a tin oxide doped with antimony or the like as a doping agent. Since the tin oxide doped in this manner has conductivity, it can reduce the surface resistivity of the laminated film and prevent impurities such as dust from adhering. Examples of tin oxide doped with antimony include FS-10D, SN-38F, SN-88F, SN-100F, TDL-S, and TDL-1 (all manufactured by Ishihara Sangyo Co., Ltd.). Can be preferably used in the present invention. Note that tin oxide using phosphorus as a doping agent can also be suitably used.

Zirconium oxide (IV) having a composition of ZrO ₂ is preferably used as the zirconium oxide. For example, NZS-20A, NZS-30A (both manufactured by Nissan Chemical Co., Ltd.) and the like can be mentioned. As the titanium oxide, titanium (IV) oxide having a composition of TiO ₂ is preferably used. Titanium oxide includes a rutile type which is a tetragonal high-temperature type and an anatase type which is a tetragonal low-temperature type depending on the crystal structure, but is not particularly limited. Further, titanium oxide subjected to surface treatment can also be used. Examples of titanium oxide that can be suitably used include IT-S, IT-O, and IT-W (all manufactured by Idemitsu Kosan Co., Ltd.) and TTO-W-5 (produced by Ishihara Sangyo Co., Ltd.). Can be mentioned.

  The molecular weight of the polymer used for the first easy-adhesion layer 12 and the second easy-adhesion layer 13 is not particularly limited, but is usually a weight average molecular weight for the purpose of forming a layer having excellent handling properties and a good flat surface. It is preferable to use the one of 3000 to 1000000. When the weight average molecular weight of the polymer is 3000 or more, there is no possibility that the strength of the first easy-adhesion layer 12 and the second easy-adhesion layer 13 is insufficient as compared with the case of less than 3000. In addition, when the weight average molecular weight of the polymer is 1,000,000 or less, the ease of application due to the decrease in fluidity is not impaired as compared with the case where the weight average molecular weight exceeds 1,000,000. Deterioration of the surface state of the adhesive layer 13 is suppressed.

  The first easy-adhesion layer 12 and the second easy-adhesion layer 13 preferably contain a compound having a plurality of carbodiimide structures in the molecule. When such a compound is included to form the first easy-adhesion layer 12 and the second easy-adhesion layer 13, when fine particles are contained, the peeling is prevented. The carbodiimide-based compound is not particularly limited as long as it has a plurality of carbodiimide groups, and the number of carbodiimide groups is not limited. Polycarbodiimide is usually synthesized by a condensation reaction of organic diisocyanate. The organic group of the organic diisocyanate used in this synthesis is not particularly limited, and either aromatic or aliphatic, or a mixture thereof can be used. An aliphatic system is particularly preferred from the viewpoint of reactivity. As the synthetic raw material, organic isocyanate, organic diisocyanate, organic triisocyanate and the like are used.

  As examples of organic isocyanates, aromatic isocyanates, aliphatic isocyanates, and mixtures thereof can be used. Specifically, 4,4'-diphenylmethane diisocyanate, 4,4-diphenyldimethylmethane diisocyanate, 1,4-phenylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, hexamethylene diisocyanate, cyclohexane Diisocyanate, xylylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 1,3-phenylene diisocyanate and the like are used. As the organic monoisocyanate, isophorone isocyanate, phenyl isocyanate, cyclohexyl isocyanate, butyl isocyanate, naphthyl isocyanate and the like are used. Moreover, as a carbodiimide type compound which can be used for this invention, it can also obtain as commercial items, such as carbodilite V-02-L2 (brand name: Nisshinbo Co., Ltd. product).

  It is preferable to add the carbodiimide type compound of this invention in 1-200 mass% with respect to a binder. More preferably, it is adding in 5-100 mass%. By making the addition amount of the carbodiimide-based compound 1% by mass or more, the first easy-adhesion layer 12 and the second easy-adhesion layer 13 peel off the fine particles when compared with the case of less than 1%. It can be sufficiently prevented. Moreover, by making the addition amount 200% by mass or less, deterioration of the planar shape of the first easy-adhesive layer 12 and the second easy-adhesive layer 13 can be suppressed as compared with the case where the amount exceeds 200% by mass.

  For the first easy-adhesion layer 12 and the second easy-adhesion layer 13, fine particles having an action as a matting agent may be used for the purpose of improving slipperiness. As the matting agent, either organic or inorganic fine particles can be used. Examples thereof include polymer fine particles such as polystyrene, polymethyl methacrylate, silicone resin, and benzoguanamine resin, and inorganic fine particles such as silica, calcium carbonate, magnesium oxide, and magnesium carbonate. Among these, polystyrene, polymethyl methacrylate, and silica are preferable because of improved slipperiness and low cost.

In order to impart good slipperiness, it is preferable to use a matting agent having an average particle size of 0.01 μm or more and 12 μm or less. More preferably, a matting agent having an average particle size of 0.03 μm or more and 9 μm or less is used. By setting the average particle size of the matting agent to 0.01 μm or more, better slipperiness can be obtained as compared to the case of less than 0.01 μm. Further, by setting the average particle size to 12 μm or less, there is no possibility that the display quality of the image display device is deteriorated as compared with the case of exceeding 12 μm. Further, the amount of the matting agent added varies depending on the average particle diameter, but it is excellent in the effect of improving the slipperiness and does not deteriorate the display quality of the image display device, so that it is 0.1 mg / m ² or more and 30 mg / m. It is preferably ² or less, more preferably 0.5 mg / m ² or more and 20 mg / m ² or less. When the addition amount of the matting agent is 0.1 mg / m ² or more, an effect of improving slipperiness can be obtained. Moreover, the fall of the display quality of an image display apparatus can be suppressed by setting it as 30 mg / m < ² > or less. The average particle size of the matting agent in the present invention is a value measured by the same method as the average particle size of the fine particles described above.

Various additives such as a surfactant can be used for the first easy-adhesion layer 12 and the second easy-adhesion layer 13. Examples of the surfactant include known anionic, nonionic, and cationic surfactants. Surfactants that can be used in the present invention are described in, for example, “Surfactant Handbook” (Nishi Ichiro, Imai Sachiichiro, Sho Kasai edited by Sangyo Kasai Co., Ltd., 1960). When using a surfactant, the addition amount is preferably 0.1 mg / m ² or more and 30 mg / m ² or less, more preferably 0.2 mg / m ² or more and 10 mg / m ² or less. By making the addition amount of the surfactant 0.1 mg / m ² or more, the effect by the surfactant can be obtained compared to the case of making it less than 0.1 mg / m ² , and the first easy-adhesion layer 12 and the second Occurrence of cissing in the easy-adhesion layer 13 is suppressed. Moreover, by making the addition amount 30 mg / m ² or less, it is possible to suppress deterioration of the surface states of the first easy-adhesion layer 12 and the second easy-adhesion layer 13 as compared with the case where the amount exceeds 30 mg / m ^2. .

An antistatic agent can be used for the first easy-adhesive layer 12 and the second easy-adhesive layer 13 for the purpose of antistatic. The type of the antistatic agent is not particularly limited. For example, an electron conductive polymer such as polyaniline and polypyrrole, an ion conductive polymer having a carboxyl group or a sulfonic acid group in the molecular chain, conductive fine particles, etc. Is mentioned. The conductive fine particles may be fine particles that are the same as the fine particles mainly containing tin oxide and indium oxide. For example, the conductive tin oxide fine particles described in JP-A-61-020033 can be preferably used from the viewpoints of conductivity and transparency. When the antistatic agent is used, the addition amount thereof is such that the surface resistance of the first easy-adhesive layer 12 and the second easy-adhesive layer 13 measured in an atmosphere of 25 ° C. and 30% RH is 1 × 10 ⁵ Ω or more and 1 × 10 ^13. It is preferable to adjust so as to be Ω or less. By making the surface resistance of the first easy-adhesive layer 12 and the second easy-adhesive layer 13 1 × 10 ⁵ Ω or more, avoid using a large amount of antistatic agent compared to the case of less than 1 × 10 ⁵ Ω. , A decrease in the transparency of the first easy-adhesion layer 12 and the second easy-adhesion layer 13 is suppressed. Further, by setting the surface resistance to 1 × 10 ¹³ Ω or less, an antistatic effect can be ensured as compared with the case where the surface resistance exceeds 1 × 10 ¹³ Ω, and the first easy-adhesive layer 12 and the second easy-adhesive layer. There is no possibility that impurities such as dust adhere to the surface of 13.

A slipping agent is preferably used for the first easy-adhesion layer 12 and the second easy-adhesion layer 13 in order to improve the slipperiness. As such a slipping agent, an aliphatic wax is preferably used, and the amount added is preferably 0.1 mg / m ² or more and 30 mg / m ² or less. More preferably, the addition amount is 0.5 mg / m ² or more and 10 mg / m ² or less. By making the addition amount of the slip agent 0.1 mg / m ² or more, sufficient slipperiness can be expressed. Moreover, the fall of the adhesive strength in an interface can be suppressed by making addition amount into 30 mg / m < ² > or less. The aliphatic wax that can be used in the present invention is described in detail in JP-A No. 2004-054161.

  The above various additives for improving the surface are added to both the first easy-adhesion layer 12 and the second easy-adhesion layer 13, but the second easy-adhesion layer 13 is added following the first easy-adhesion layer 12. When forming continuously, you may add only to the 2nd easily bonding layer 13. FIG.

  A method for forming the first easy-adhesion layer 12 and the second easy-adhesion layer 13 will be described. In this embodiment, after applying a coating solution in which a polymer resin, fine particles, additives, and the like and a solvent are mixed in advance to the surface of the support 11 (biaxially stretched polyethylene terephthalate film) to form a coating layer, The first easy-adhesion layer 12 and the second easy-adhesion layer 13 are sequentially formed by a coating method for drying the coating layer. As said solvent, ie, a coating solvent, water, toluene, methyl alcohol, isopropyl alcohol, methyl ethyl ketone, etc., and mixtures thereof can be used. Water can also be used as the coating solvent. In this case, water acts as a coating solvent. Thus, when water is used as a coating solvent, it is preferable because manufacturing cost and manufacturing can be simplified.

  The coating solution is preferably applied to the biaxially stretched support 11, but after providing the first easy-adhesion layer 12 on the uniaxially stretched support 11, the support 11 is It is also possible to carry out biaxial stretching by uniaxially stretching in different directions to produce the support 11 on which the first easy-adhesion layer 12 is applied, and further to apply the second easy-adhesion layer 13 off-line. Here, uniaxial means either the width direction or the longitudinal direction of the support 11, and when biaxial stretching is performed, the order of the stretching direction is not limited.

  The formation method of the 1st easily bonding layer 12 and the 2nd easily bonding layer 13 will not be specifically limited if the layer of desired thickness can be formed. Therefore, the coating method is not limited, and a known method used when forming a thin film can be used. Examples of the method include a dipping method, a spinner method, a spray method, a roll coater method, a gravure method, a wire bar method, a slot extrusion coater method (single layer and multilayer), and a slide coater method. The first and second easy-adhesion layers 12 and 13 may be applied individually off-line in addition to on-line sequential application. Said method can be used as a formation method of the layer which concerns on this invention, ie, the 1st easily bonding layer 12, the 2nd easily bonding layer 13, the hard-coat layer 14, and the antireflection layer 15. FIG.

[Hard coat layer]
The hard coat layer 14 is preferably formed using an energy curable resin or a thermosetting resin. Among these, it is preferable to use an energy curable resin. Since the energy curable resin is cured by irradiating active energy rays, the resin is not damaged as compared with a heat energy curable resin that uses heat as energy during curing. Therefore, it has the feature that a highly transparent layer can be formed.

  The energy curable resin used when forming the hard coat layer 14 will be described. The energy curable resin is preferably a curable resin having two or more acrylic groups in the same molecule. For example, ethylene glycol diacrylate, 1,6-hexanediol diacrylate, bisphenol-A diacrylate, trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, Polyol polyacrylates such as dipentaerythritol hexaacrylate, polyfunctional urethane acrylate obtained by reaction of polyisocyanate curable resin and hydroxyl group-containing acrylate such as hydroxyethyl acrylate, polyepoxy curable resin and hydroxyethyl acrylate, etc. Polyfunctional ester obtained by reaction with hydroxyl group-containing acrylate (methacrylate) Carboxymethyl acrylate, and the like. It is also possible to use a polymer having an ethylenically unsaturated group in the side chain.

  When using an energy curable resin, it is preferable to irradiate the coating layer with ionizing radiation such as radiation, gamma rays, alpha rays, electron rays, ultraviolet rays, which are active energies. As a result, the resin can be cured efficiently and effectively, so that a coating layer having a sufficient hardness, that is, the hard coat layer 14 can be formed. In addition, when forming the hard-coat layer 14, after apply | coating the coating liquid for forming the hard-coat layer 14 to the 2nd easily bonding layer 13, and forming an application layer, this application layer is irradiated with an ultraviolet-ray It is preferable to do. Thereby, the hard coat layer 14 having a uniform film thickness and uniform optical characteristics can be obtained within a short time. In addition, it is preferable to use a solution obtained by diluting a desired energy curable resin, a polymerization initiator, or the like with a solvent in advance, because a coating layer having a uniform film thickness can be easily formed.

  In the present invention, the polymerization initiators may be used alone or in combination, and are not particularly limited. Further, the addition amount of the polymerization initiator is not particularly limited, but the sum of the ethylenically unsaturated group-containing curable resin and the ring-opening polymerizable group-containing curable resin contained in the curable resin composition. And 0.1 to 15% by mass is preferable. More preferably, the addition amount with respect to the above-mentioned total is 1 to 10% by mass.

  The refractive index of the hard coat layer 14 is preferably 1.75 or more and 2.00 or less, for example, by adding inorganic fine particles to the binder used for forming the hard coat layer 14. In general, since inorganic fine particles have a high refractive index of 1.8 to 2.7, the refractive index of the layer to be formed can be adjusted within the range of the high refractive index as described above. By setting the refractive index of the hard coat layer 14 to 1.75 or more, it becomes easy to reduce the reflectance as compared with the case of less than 1.75. Further, by setting the refractive index to 2.00 or less, the hard coat layer 14 does not become brittle compared to the case where the refractive index exceeds 2.00, and deterioration of scratch resistance can be suppressed.

  As an example of a composition capable of forming a hard coat layer 14 exhibiting a high refractive index, a polyfunctional acrylate monomer is used as a resin component, which contains inorganic fine particles such as alumina and titanium oxide. And the composition disclosed in Japanese Patent No. 1815116. In addition, there is a detailed description in Japanese Patent No. 1416240 as a photopolymerizable compound composition containing inorganic fine particles made of alumina, and these descriptions can also be applied to the present invention. However, the hard coat layer 14 used in the present invention is not limited to the above example.

  The high refractive index hard coat layer 14 can also be formed by using a polymer having a high refractive index. Examples of the polymer having a high refractive index include a polymer having a cyclic group, a polymer containing a halogen atom other than fluorine, and a polymer containing both a cyclic group and a halogen atom other than fluorine. The cyclic group includes an aromatic group, a heterocyclic group, an aliphatic ring group, and the like.

  The thickness of the hard coat layer 14 is not particularly limited, but is preferably 0.5 μm or more and 10 μm or less. More preferably, they are 1 micrometer or more and 5 micrometers or less. Thereby, it has a desired optical function and a physical function such as excellent scratch resistance, and furthermore, a high adhesive strength at the interface between the second easy-adhesive layer 13 and the hard coat layer 14 can be secured. When the film thickness of the hard coat layer 14 is 0.5 μm or more, the physical function can be sufficiently expressed and the scratch resistance is excellent. In the case of 10 μm or less, it is possible to secure a high adhesive strength at the interface between the second easy-adhesive layer 13 and the hard coat layer 14 by reducing the influence of curing and absorption of the hard coat layer 14.

(Antireflection layer)
In order to provide an antireflection effect, the antireflection layer 15 is a layer having a lower refractive index than the hard coat layer 14. In order to form a low refractive index layer, adjustment is performed by using a low refractive index material such as a fluorine-based material or a silicone-based material as a binder. The refractive index of the antireflection layer 15 is preferably 1.50 or less. In this case, the antireflection performance is ensured as compared with the case of exceeding 1.50. When forming the antireflection layer 15, a commercially available coating material for an antireflection film can be used. As such a coating material, when a low refractive index layer is formed, commercially available low refractive index materials such as TT1148, TU2111, and TU2153 (all manufactured by JSR Corporation) and the like can be mentioned.

  The laminated film obtained as described above has high adhesive strength at each interface, and light interference at each interface is suppressed, so that the occurrence of rainbow unevenness is reduced. Such a laminated film excellent in optical function can be used in various image display devices as an antireflection film excellent in display quality.

  The laminated film of the present invention can be used as an optical film for use in liquid crystal displays, PDPs (plasma displays), organic EL displays, SED (surface electric field) displays, and CRT displays. For these image display devices, for example, “Display Advanced Technology” (published by Tanizuka, Kyoritsu Publishing Co., Ltd. 1998), “EL, PDP, LCD Display” (Toray Research Center, Inc. 2001) And “Color LCD” (Shunsuke Kobayashi, Sangyo Tosho Publishing Co., Ltd., published in 1990).

  The laminated film of the present invention can be suitably used as an antireflection film, an IR absorption film, an electromagnetic wave shielding film, an optical film such as a toning film, and a film filter in which these films are integrated, which are used for PDP. These films are described, for example, on page 74 of the August 2002 issue of Electric Journal, in addition to the above-mentioned documents.

  Next, each layer of the optical laminated film 20 having the NIRA coat layer 18 will be described. The first adhesive layer 12, the second adhesive layer 13, the hard coat layer 14, and the antireflection layer 15 are the same as those of the laminated film 10 having the hard coat layer 14, and detailed description thereof is omitted. For the first easy-adhesion layer 16 for forming the NIRA coat layer 18, the same material as the first easy-adhesion layer 12 of the laminated film 10 is used.

  For the second easy adhesion layer 17 for forming the NIRA coat layer 18, the same material as the second easy adhesion layer 13 of the laminated film 10 is used.

  The NIRA coat layer 18 is composed of a near-infrared shielding agent and an organic binder. The near-infrared shielding agent may be a conventionally known one, and is not particularly limited. For example, metal oxides such as indium tin oxide, indium oxide, tin oxide, silicon oxide, aluminum oxide, zinc oxide, and tungsten oxide; phthalocyanine series , Anthraquinone-based, naphthoquinone-based, cyanine-based, naphthalocyanine-based, polymer-condensed azo-based, pyrrole-based organic dye-type organic dye types; dithiol-based, mercaptonaphthol-based organometallic complexes, and the like. These near infrared shielding agents can be used alone or in combination of two or more.

  Moreover, as a commercially available near-infrared shielding material, for example, IRG-02, IRG-022, IRG-023, IRG-040 (above, manufactured by Nippon Kayaku Co., Ltd.), IR1, IR2, IR3, IR4, TX-EX- 810K, TX-EX-812K, TX-EX-905B (manufactured by Nippon Shokubai Co., Ltd.), SIR-128, SIR-130, SIR-132, SIR-159 (manufactured by Mitsui Chemicals, Inc.), CIR- 1080, CIR-1081 (manufactured by Nippon Carlit Co., Ltd.), NKX-1199 (Nippon Sensitive Dye Co., Ltd.), MIR101 (manufactured by Midori Chemical Co., Ltd.) and the like.

  Moreover, when forming the layer containing a near-infrared shielding agent on a support body, a layer can be formed using the organic binder which melt | dissolved or disperse | distributed the said near-infrared shielding agent. Examples of the organic binder include polyolefins such as polyethylene and polypropylene, polystyrene compounds such as polystyrene and poly (α-methylstyrene), styrene-butadiene copolymers, styrene-isoprene copolymers, and styrene-maleic acid copolymers. Styrene copolymers such as styrene-maleic acid ester copolymer; polyvinyl compounds such as polyvinyl chloride, polyvinyl alcohol and polyvinyl acetate; poly (meth) methyl acrylate, poly (meth) ethyl acrylate, poly Poly (meth) acrylates such as propyl (meth) acrylate and polybutyl methacrylate; polyethers such as polyoxymethylene and polyethylene oxide; polyethylene succinate, polybutylene adipate, polylactic acid, polyglycolic acid, Polica Polyesters such as lolactone and polyethylene terephthalate; natural polymers such as cellulose, starch and rubber; polyamides such as 6-nylon and 6,6-nylon; polyurethane, epoxy resin, polyacrylic acid resin, rosin, modified rosin, terpene resin, Examples thereof include phenol resins, aliphatic or alicyclic hydrocarbon resins, aromatic petroleum resins, and halogen-modified products thereof. These can be used alone or in combination of two or more. Moreover, you may harden | cure by active energy ray irradiation, such as a heat | fever and an ultraviolet-ray, after apply | coating and forming a layer using a curable monomer.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. In addition, each Example and a comparative example are examples of this invention, and do not limit this invention. Therefore, the following types of materials, ratios of the respective materials, prescriptions, and the like may be appropriately changed without departing from the spirit of the present invention. In the following description, the manufacturing method, conditions, and the like will be described in detail in the first embodiment, and the description will be omitted when the other embodiments and comparative examples are the same as the first embodiment.

[Example 1]
In this example, the laminated film shown in FIG. 1 was produced according to the following procedure.

[Support]
First, after a polyethylene terephthalate (hereinafter referred to as PET) resin having an intrinsic viscosity of 0.66 polycondensed with antimony trioxide as a catalyst is dried to a moisture content of 50 ppm or less, extrusion is performed at a heater temperature set at 280 to 300 ° C. It was melted in the machine. Next, the melted PET resin was discharged from a die part onto a chill roll electrostatically applied to obtain an amorphous film. Subsequently, the amorphous film was stretched 2.9 times in the longitudinal direction of the film, and then stretched 4.0 times in the width direction of the film to give a biaxially stretched thickness of 150 μm. A support 11 was produced. The completed support 11 had a refractive index η1 of 1.65.

[Easily adhesive layer]
While the roll-shaped support 11 having a width of 2 m and a length of 2000 m was transported at a transport speed of 70 m / min, the surface was subjected to corona discharge treatment under the condition of 730 J / m ² . Thereafter, the coating liquid A was applied to both surfaces of the support 11 by a bar coating method and dried at 180 ° C. for 1 minute to form the first easy-adhesion layer 12. Subsequently, after performing a corona discharge treatment under the condition of 730 J / m ² , the coating liquid B is applied to the surface of the first easy-adhesion layer 12 by a bar coating method, and dried at 165 ° C. for 1 minute to obtain the second easy-adhesion layer 13. Was provided. The wet coating amounts of the coating liquids A and B were 4.4 ml / m ^{2 on} both sides.

[Coating liquid A]
Various raw materials were mixed to obtain a coating solution A in order to obtain the following solid coating amount.
・ Polyester resin 70.0 (mg / m ² )
-Carbodiimide compound 14.0 (mg / m ² )
Surfactant A 0.5 (mg / m ² )
Surfactant B 1.0 (mg / m ² )
-Tin oxide dispersion 14.0 (mg / m ² )
[Coating solution B]
In order to obtain the following solid coating amount, various raw materials were mixed to obtain a coating solution B.
-Polyester resin 45.0 (mg / m ² )
-Carbodiimide compound 9.0 (mg / m ² )
Surfactant A 0.5 (mg / m ² )
Surfactant B 1.0 (mg / m ² )
-Tin oxide dispersion 143.0 (mg / m ² )
Silica dispersion 1.2 (mg / m ² )
・ Carbana wax 3.0 (mg / m ² )

  The thicknesses of the first easy-adhesion layer 12 and the second easy-adhesion layer 13 after drying were measured at a magnification of 200,000 times using a transmission electron microscope (JEM2010 (manufactured by JEOL Ltd.). The film thickness d1 of the easy adhesion layer 12 was 88 nm, and the film thickness d2 of the second easy adhesion layer 13 was 86 nm, and the refractive indexes of the first easy adhesion layer 12 and the second easy adhesion layer 13 were determined by the following method. The measured values were 1.567 and 1.650, respectively.

[Measurement of thickness of easy-adhesion layer]
The thickness of the easy adhesion layer is measured as follows. First, the film on which the easy-adhesion layers 12 and 13 are applied is embedded in an epoxy resin and dried, and then the cross section is cut with a microtome so as to have a thickness of 100 nm to obtain a sample piece. The sample piece is photographed with the transmission electron microscope at a magnification of 200,000 times. The film thickness was measured at 10 points at 20 nm intervals in the photographed image, and the average value excluding the maximum and minimum values was taken as the thickness.

[Measurement of refractive index of easy-bonding layer]
Using a refractive index measuring machine (SPA-4000 (manufactured by Sairon Technology, Inc.)), the refractive index at wavelengths of 660 nm and 850 nm of the sample provided with the coating layer was measured by the prism coupler method. Next, the refractive index at 550 nm was calculated from the measured value of the refractive index at each wavelength and the following Cermeier equation, and this was taken as the refractive index η1 in the first layer. The Selmeier equation is an equation represented by η ² −1 = Aλ ² / (λ ² −B). Here, λ is a measurement wavelength (nm), η is a refractive index at the measurement wavelength, and A and B are constants. After the constants A and B are obtained by substituting the measurement wavelength and the refractive index into the above formula, the refractive index at 550 nm can be obtained by substituting the wavelength = 550 nm. The above sample is prepared by applying a coating solution on a commercially available silicon wafer so that the film thickness after drying is 3 to 4 μm and providing a coating layer, and then drying it at 105 ° C. for 10 minutes. did.

[Hard coat layer]
Titanium oxide TTO-55B (Ishihara Sangyo Co., Ltd.) 30 mass% cyclohexanone dispersion was prepared. MEK was added to 2 parts by mass of TTO-55B dispersion 177 parts by mass, DPHA (dipentaerythritol hexaacrylate: Nippon Kayaku Co., Ltd.) 20 parts by mass, Irgacure 184 (Ciba Specialty Chemicals), and solid content 8% by mass. A hard coat layer coating solution was prepared. A hard coat layer coating solution is applied to one surface of the formed easy-adhesion layers on both sides so as to have a film thickness of about 35 μm, and then the coating layer is dried at 80 ° C. for 1 minute. I let you. Next, the resin was cured by irradiating the dried coating layer with ultraviolet rays using a high-pressure mercury lamp to form a 3 μm hard coat layer 14. In addition, the irradiation amount of the ultraviolet-ray with respect to a coating layer was 1000 mJ / cm < ² >. Moreover, it was 1.83 when (eta) 4 which is the refractive index of the hard-coat layer 14 was measured similarly to the refractive index measuring method of the 1st easily bonding layer 12. FIG.

(Antireflection layer)
On the hard coat layer 14, TU2111 manufactured by JSR Co., Ltd. was applied and dried, followed by UV irradiation (1000 mJ / cm ² ), and a low refractive index layer having a thickness of 0.1 μm was provided (refractive index is 1.39). ). Since the hard coat layer 14 has a high refractive index of 1.83, the low refractive index layer functions as the antireflection layer 15.

[Example 2]
As shown in Table 1, the experiment was performed in the same manner as in Example 1 except that the coating liquid A in Example 1 was changed to C and the coating liquid B was changed to D.
[Coating fluid C]
Various raw materials were mixed to obtain a coating solution C in order to obtain the following solid coating amount.
・ Polyurethane resin 52.0 (mg / m ² )
-Carbodiimide compound 10.4 (mg / m ² )
Surfactant A 0.5 (mg / m ² )
Surfactant B 1.0 (mg / m ² )
-Tin oxide dispersion 110.0 (mg / m ² )

[Coating fluid D]
Various raw materials were mixed to obtain a coating solution D in order to obtain the following solid coating amount.
・ Polyurethane resin 47.0 (mg / m ² )
-Carbodiimide compound 9.4 (mg / m ² )
Surfactant A 0.5 (mg / m ² )
Surfactant B 1.0 (mg / m ² )
-Titanium oxide dispersion 66.0 (mg / m ² )
Silica dispersion 1.2 (mg / m ² )
・ Carbana wax 3.0 (mg / m ² )

[Example 3]
As shown in Table 1, the experiment was performed in the same manner as in Example 1 except that the coating liquid A in Example 1 was changed to E and the coating liquid B was changed to F.

[Coating fluid E]
Various raw materials were mixed to obtain a coating solution E in order to obtain the following solid coating amount.
Acrylic resin 73.0 (mg / m ² )
-Carbodiimide compound 14.6 (mg / m ² )
Surfactant A 0.5 (mg / m ² )
Surfactant B 1.0 (mg / m ² )
-Tin oxide dispersion 14.0 (mg / m ² )

[Coating fluid F]
In order to obtain the following solid coating amount, various raw materials were mixed to obtain a coating solution F.
・ Polyester resin 58.0 (mg / m ² )
-Carbodiimide compound 11.6 (mg / m ² )
Surfactant A 0.5 (mg / m ² )
Surfactant B 1.0 (mg / m ² )
-Tin oxide dispersion 56.0 (mg / m ² )
Silica dispersion 1.2 (mg / m ² )
・ Carbana wax 3.0 (mg / m ² )

[Comparative Example 1]
As shown in Table 1, the experiment was performed in the same manner as in Example 1 except that the coating liquid C in Example 2 was changed to D and the coating liquid D was changed to C.

[Comparative Example 2]
As shown in Table 1, the experiment was performed in the same manner as in Example 1 except that the coating liquid E in Example 3 was changed to F and the coating liquid F was changed to E.

[Comparative Example 3]
As shown in Table 1, the experiment was performed in the same manner as in Example 1 except that the coating liquid A in Example 1 was set to G and the second easy-adhesion layer was not provided.

[Coating fluid G]
In order to obtain the following solid coating amount, various raw materials were mixed to obtain a coating solution F.
・ Polyurethane resin 43.2 (mg / m ² )
-Carbodiimide compound 8.6 (mg / m ² )
Surfactant A 0.5 (mg / m ² )
Surfactant B 0.9 (mg / m ² )
-Titanium oxide dispersion 79.0 (mg / m ² )
Silica dispersion 1.1 (mg / m ² )
・ Carbana wax 3.0 (mg / m ² )

Various materials used in the preparation of the coating liquids A to G are as follows.
Polyester resin: Z-561 manufactured by Kyoyo Chemical Industry Co., Ltd., solid content 25%.
Carbodiimide compound: Nisshinbo Co., Ltd., Carbodilite V-02-L2, solid content 10% aqueous solution, carbodiimide equivalent 385.
Surfactant A: Nippon Oil & Fat Co., Ltd., Rapisol B-90, 1% solid content aqueous solution, anionic.
Surfactant B: Sanyo Kasei Kogyo Co., Ltd., NAROACTY HN-100, 5% solid content aqueous solution, nonionic.
Tin oxide dispersion: manufactured by Ishihara Sangyo Co., Ltd., antimony-doped tin oxide SN-38F, solid content 17% aqueous solution, average particle size 30 nm.
Silica dispersion: Nippon Aerosil Co., Ltd., OX-50 aqueous dispersion, solid content 10% aqueous solution.
Carnauba wax: manufactured by Chukyo Yushi Co., Ltd., Cellozol 524, 3% solid content aqueous solution.
Polyurethane resin: UD-350 manufactured by Mitsui Chemicals Co., Ltd. Solid content 38%.
Titanium oxide dispersion: manufactured by Ishihara Sangyo Co., Ltd., TTO-W-5, 30% solid content aqueous solution (average particle size 70 nm).
Acrylic resin: Nippon Pure Chemical Industries, Ltd. ET-410 Solid content 30%.

  With respect to the laminated films produced in each of the above Examples 1 to 3 and Comparative Examples 1 to 3, the following five items related to adhesiveness, optical characteristics, etc. were evaluated. Evaluation 1 is the adhesion between the support 11 and the first easy-adhesion layer 12, evaluation 2 is the adhesion between the second easy-adhesion layer 13 and the hard coat layer 14, evaluation 3 is the coated surface of the laminated film, and evaluation 4 is The presence or absence of rainbow unevenness in the laminated film, evaluation 5 is scratch resistance. Below, the detail of each evaluation method is shown.

[Adhesiveness between support and first easy-adhesion layer]
First, the coating liquid used for forming the first easy-adhesion layer 12 in each Example and Comparative Example was applied to the surface of the support 11, and then this sample was immersed in distilled water at 60 ° C. for 16 hours. Next, the sample after immersion is taken out of the distilled water, and water droplets adhering to the surface of the sample are lightly wiped with paper (Kimwipe S-200, manufactured by Crecia Co., Ltd.), and immediately, the surface of the sample is immediately removed. Was scratched with a 0.1 R diamond needle using a scratch strength tester (HEIDON-18, manufactured by Shinto Kagaku Co., Ltd.). Then, after observing the rubbed portion with a microscope magnification of 100, and further visually observing and judging the degree of peeling of the first easy-adhesive layer 12 according to the following criteria, 1 The adhesive strength with the easy-adhesion layer 12, that is, the adhesiveness was evaluated in five stages. The load applied to the diamond needle was 200 g. In the following evaluation, the rank B or higher is a level with no problem in terms of products.
Rank A: When there is no peeling Rank B: When the peeled area is less than 30% of the area rubbed with the diamond needle Rank C: With respect to the area of the peeled area rubbed with the diamond needle 30% or more and less than 70% D rank: When the peeled area is 70% or more and 100% or less of the area of the portion rubbed with the diamond needle E rank: In addition to the portion rubbed with the diamond needle, its peripheral portion When peeling occurs to the coating layer

[2. Adhesiveness between 2nd easy adhesion layer and hard coat layer]
The film on which the hard coat layer 14 was laminated was conditioned for 24 hours in an atmosphere of 25 ° C. and 60% RH to prepare a sample. Next, using a single-blade razor, the surface to be used as an evaluation surface of this sample was made with 25 scratches by making 6 vertical and horizontal scratches, and then cellophane tape (405 manufactured by Nichiban Co., Ltd.) was formed thereon. No., 24 mm width). And after rubbing the top of the cellophane tape with poppy rubber and completely adhering it to the horizontal plane, the number of squares peeled off is obtained by obtaining the number of squares peeled off. The high adhesive strength, that is, the adhesiveness was evaluated in five stages. In the case of partial peeling within the squares, the peeled parts were integrated and converted to the number of squares. In the following evaluation, rank B or higher is a level with no problem in terms of product. The width of the scratch was 3 mm both vertically and horizontally.
Rank A: No peeling B rank: When the number of peeled squares is less than 1 Rank C: When the number of peeled squares is 1 or more and less than 3 D rank: When the number of peeled squares is 3 or more and less than 20, E rank : When the number of peeled cells is 20 or more

[3. (Apply surface of easy-adhesive film)
First, a first easy-adhesion layer 12 and a second easy-adhesion layer 13 were formed on the surface of the support 11 to prepare a sample. Next, the sample was placed on a desk on which a black doskin cloth was bonded, and then the diffused light of a fluorescent lamp passed through a milky white acrylic plate was applied to the coating layer. And the reflected light which generate | occur | produces here was observed visually and the coating nonuniformity was judged by the following reference | standard, and it evaluated in three steps as a coating surface shape. In the following evaluation, the rank B or higher is a level with no problem in terms of products.
Rank A: Coating unevenness is not visually confirmed in both the blackened sample and the untreated sample.
Rank B: Coating unevenness is visually confirmed in the sample after the blackening treatment, but is not confirmed in the untreated sample.
C rank: Coating unevenness is visually confirmed in both the sample after the blackening treatment and the untreated sample.

  In the above evaluation 3, in the visual judgment, blackening treatment was performed on a predetermined surface of the sample in order to prevent reflection from the back surface, and the transmittance of 550 nm light was adjusted to 1% or less. In the above blackening treatment, magic ink (artline oil-based marker supplement ink KR-20 black, manufactured by shachihata Co., Ltd.) was applied to the surface of the sample opposite to the surface to be observed, and then dried.

[4. (With or without rainbow unevenness)
First, a sample was prepared by conditioning the completed laminated film (provided up to the antireflection layer 15) in an atmosphere of 25 ° C. and 60% RH for 24 hours. Next, after rubbing an appropriate amount of the surface of this sample without the hard coat layer 14 with sandpaper, the same black magic as that used in the evaluation 3 was applied to prevent back surface reflection. . Then, this sample is placed on a desk, and interference spots (rainbow unevenness) generated by illuminating with a three-wavelength fluorescent lamp (trade name: National Parook fluorescent lamp FL20SS / EX-D / 18) from 30 cm above are obtained. It was observed visually. The interference spots observed in this observation were regarded as rainbow unevenness and evaluated in five stages according to the following criteria. In the evaluation described later, the rank C or higher is a level that does not cause a problem in terms of products.
A rank: The rainbow nonuniformity cannot be seen at all.
B rank: The rainbow nonuniformity is hardly visible.
C rank: Some rainbow unevenness is visible.
D rank: Rainbow unevenness looks strong.
E rank: Rainbow unevenness looks very strong.

[5. (Scratch resistance)
First, an easy-adhesion layer was formed on the surface of the support 11 to produce a laminated film. Using a continuous load type scratch strength tester TYPE-HEIDON-18 (Shinto Kagaku Co., Ltd., detection needle: sapphire needle 0.1R scratching speed: 600 mm / min, weight used: 200 g weight), scratches are generated on the laminated film. The load at the time was determined.
Rank A: Load at the time of scratch generation ≧ 30 g Good scratch resistance.
Rank B: 30 g> load at the time of scratch generation ≧ 20 g No problem in practical use.
Rank C: 20 g> Load at the time of scratch ≧ 20 g Problem D rank: 10 g> Load at the time of scratch occurrence Problem

  The evaluation results in each example and comparative example are summarized in Table 1.

  As shown in Table 1, in each Example, good results were shown for use as products for all evaluations. On the other hand, in each of the comparative examples, both of Comparative Examples 1 and 2 were confirmed to have rainbow unevenness as a problem as a product. Moreover, in the comparative example 3, an easily bonding layer is 1 layer structure, and the rainbow nonuniformity evaluation is favorable with A. The refractive index of the easy-adhesion layer is 1.74. Thus, when trying to obtain a high refractive index, it is necessary to make the metal oxide particle content rate of an easily bonding layer high. As a result, it becomes a D rank in the evaluation of scratch resistance and has a practical problem. Moreover, since the metal oxide particle content rate was high, the strength of the easy-adhesion layer was lowered, and as a result, the hard coat adhesiveness was deteriorated and the adhesiveness of evaluation 2 was C rank.

  Next, the present invention will be described in more detail by giving examples and comparative examples to the second embodiment and the third embodiment of the present invention.

[Example 11]
In this example, a laminated film 20 shown in FIG. 2 was prepared according to the following procedure. First, the same laminated film 10 as in the first example was obtained. First and second easy adhesion layers 16 and 17 and a NIRA coat layer 18 were formed on the laminated film 10. As a result, a laminated film 20 having the hard coat layer 14 and the antireflection layer 15 on one side of the support 11 and the NIRA coat layer 18 on the other side was obtained.

The first and second easy-adhesion layers 16 and 17 and the NIRA coat layer 18 were formed on the laminated film 10 as follows. First, a roll-shaped laminated film 10 having a width of 2 m and a length of 2000 m was obtained in the same manner as in the first example. Next, while transporting at a transport speed of 70 m / min, the surface was subjected to corona discharge treatment under the condition of 730 J / m ² . Thereafter, the coating liquid K was applied to the support 11 side of the laminated film 10 by a bar coating method and dried at 180 ° C. for 1 minute to form the first easy-adhesion layer 16. Subsequently, after performing a corona discharge treatment under the condition of 730 J / m ² , the coating liquid L was applied to the surface of the first easy-adhesion layer 16 by a bar coating method, and dried at 165 ° C. for 1 minute to give a second easy-adhesion layer 17 was provided. The wet coating amounts of the coating liquids K and L were 4.4 ml / m ^{2 on} both sides.

[Coating liquid K]
Various raw materials were mixed to obtain a coating solution K in order to obtain the following solid coating amount.
・ Polyester resin 55.0 (mg / m ² )
-Carbodiimide compound 11.0 (mg / m ² )
Surfactant A 0.5 (mg / m ² )
Surfactant B 1.0 (mg / m ² )
-Tin oxide dispersion 91.0 (mg / m ² )

[Coating liquid L]
Various raw materials were mixed to obtain a coating liquid L in order to obtain the following solid coating amount.
Acrylic resin 60.0 (mg / m ² )
-Carbodiimide compound 12.0 (mg / m ² )
Surfactant A 0.5 (mg / m ² )
Surfactant B 1.0 (mg / m ² )
-Tin oxide dispersion 65.0 (mg / m ² )
Silica dispersion 1.1 (mg / m ² )
・ Carbana wax 3.0 (mg / m ² )

[NIRA coat layer]
As a near-infrared absorbing dye, 3.1 parts by weight of “IRG-022”, 0.5 parts by weight of “IR1” and 1.7 parts by weight of “SIR-159” are dissolved in 100 parts by weight of methyl ethyl ketone, and commercially available as a binder. The mixture was stirred with 880 parts by weight of an ultraviolet curable resin (trade name “Z7503”, manufactured by JSR Corporation) to prepare a NIRA coat layer coating solution. First, the NIRA coat layer coating solution was applied on the second easy-adhesion layer 17 so as to have a film thickness of about 20 μm, and dried at 70 ° C. for 2 minutes. After drying, the film was cured by irradiating with 500 mJ / cm ² of ultraviolet rays to prepare a NIRA coat layer laminated film 20 having a dry film thickness of 9 microns.

  The prepared NIRA coat layer laminated film 20 was conditioned for 24 hours in an atmosphere of 25 ° C. and 60% RH. Next, after the surface of the NIRA coat layer of this sample was rubbed with sand paper in an appropriate amount, the same black magic as that used in Evaluation 3 was applied to prevent reflection of the NIRA coat layer surface. Then, this sample is placed on a desk so that the antireflection layer side is on, and illuminated with a three-wavelength fluorescent lamp (trade name: National Parook fluorescent lamp FL20SS / EX-D / 18) from 30 cm above. The generated interference spots (rainbow unevenness) were visually observed. The interference spots observed in this observation were regarded as rainbow unevenness and evaluated according to the above criteria in five levels. The result was A rank, and it was found that rainbow unevenness could be suppressed.

[Example 12]
Example 12 is the same as Example 11 except that the first easy-adhesion layer and the second easy-adhesion layer on the hard coat layer side of Example 11 are changed to one easy-adhesion layer. The easy-adhesion layer was produced using the coating liquid G as in Comparative Example 3.

[Comparative Example 11]
In Comparative Example 11, only the first easy-adhesion layer was provided instead of the NIRA layer side of Example 11 and the first and second easy-adhesion layers. is there. The easy-adhesion layer was prepared as in Example 3 using the coating liquid E.

  As shown in Table 1, it can be seen that Examples 11 and 12 are good because the evaluation result of rainbow unevenness is A. On the other hand, it can be seen that Comparative Example 11 is inferior because the rainbow unevenness evaluation result is D.

  When the prepared antireflection film is installed in a portion where the optical filter of the commercially available PDP (H37P- manufactured by Hitachi, Ltd. is 9000) is removed, the occurrence of rainbow unevenness is suppressed, and the optical properties such as antireflection properties are very high. It was confirmed that it was excellent. Similarly, when the antireflection film with a NIRA layer was placed on the above-mentioned commercially available PDP, it was confirmed that generation of rainbow unevenness was suppressed and it was excellent as a laminated film for blocking near infrared rays.

It is general | schematic sectional drawing which shows an example of the laminated | multilayer film concerning this invention. It is general | schematic sectional drawing which shows an example of the laminated | multilayer film in 2nd Embodiment of this invention. It is general | schematic sectional drawing which shows an example of the laminated | multilayer film in 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10, 20, 30 Laminated film 11 Support body 12,16 1st easily bonding layer 13, 17 2nd easily bonding layer 14 Hard coat layer 15 Antireflection layer 18 NIRA coating layer 25 Easy bonding layer

Claims (7)

A support made of polyester, and a first easy-adhesion layer, a second easy-adhesion layer, and a surface layer arranged in order on at least one surface of the support,
When the refractive index of the support is η1, the refractive index of the first easy-adhesion layer is η2, the refractive index of the second easy-adhesion layer is η3, and the refractive index of the surface layer is η4,
(Η1 / η4) ^1/2 × 0.95 ≦ η2 / η3 ≦ (η1 / η4) ^1/2 × 1.05 is satisfied,
The surface layer is a hard coat layer, and the refractive indexes η1, η2, η3, and η4 of the respective layers are η1 <η4 and η2 <η3 ,
In the range where λ which is the wavelength of visible light is 550 nm ≦ λ ≦ 600 nm,
The thickness d1 (nm) of the first easy-adhesion layer and the η2 are
−30 ≦ d1− {λ / (4 × η2)} ≦ 30,
D2 (nm), which is the film thickness of the second easy-adhesion layer, and η3 are
An optical laminated film characterized by satisfying −30 ≦ d2− {λ / (4 × η3)} ≦ 30 .   2. The optical laminated film according to claim 1, wherein the first easy-adhesion layer and the second easy-adhesion layer contain one or more of a polyester resin, a polyurethane resin, and an acrylic resin.   3. The optical laminated film according to claim 2, wherein the second easy-adhesion layer contains fine particles mainly containing any one of tin oxide, indium oxide, zirconium oxide, and titanium oxide.   4. The optical laminated film according to claim 1, wherein the first easy-adhesion layer and / or the second easy-adhesion layer contains a compound having a plurality of carbodiimide structures in the molecule. Wherein the polyester is polyethylene terephthalate, the optical laminated film according to claims 1 to 4 any one, wherein the refractive index η4 of the hard coat layer is 1.75 to 2.0. An anti-reflective layer on the hard coat layer, the antireflection layer, an optical laminate film according to any one of claims 1 5 in which the refractive index is equal to or is 1.50 or less . An image display device comprising the optical laminated film according to claim 1 .

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