JP2008012834A - Optical film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical film having excellent adhesiveness of an acrylic resin layer containing an organic coloring compound and excellent capabilities of preventing the occurrence of an interference pattern and reflection in the boundary face between the acrylic resin layer containing an organic coloring compound and a polyester film. <P>SOLUTION: The film consists of a lard coat layer 4 and an antireflective layer 11, laminated in order on one side of a polyester film, and an acrylic resin layer 8 laminated on the other side of the polyester film and containing at least one organic coloring compound. An easily adhesive layer 5 having a structure phase-separated in the direction of the thickness is arranged between the polyester film and the acrylic resin layer containing the coloring compound. The easily adhesive layer has a phase based on a polyester resin on the side of the polyester film and a phase based on an acrylic resin on the side of the acrylic resin layer containing the coloring compound, and, in the phase separation boundaries of the phases of the easily adhesive layer, there are areas where both phases are mingled. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an optical film having both an antireflection function and a function of selectively absorbing near-infrared absorption and / or visible light having a specific wavelength, and an optical filter for a plasma display or surface electric field display provided with this optical film on a surface layer.

  Anti-reflective films are used in image display devices such as cathode ray tube televisions, large-screen flat-screen televisions such as liquid crystal displays and plasma displays (hereinafter abbreviated as PDP), surface electric field displays (hereinafter abbreviated as SED) and monitors such as computers. It is used to reduce the reflection of external light sources such as fluorescent lamps and improve visibility.

  Antireflection is usually performed by utilizing light interference by an optical thin film. For example, as an antireflection film, a hard coat layer for preventing scratches is formed on a transparent substrate film such as polyester, and further, There is known one in which an antireflection layer comprising two layers of a high refractive index layer and a low refractive index layer is formed thereon (see Patent Documents 1 and 2). Here, an acrylic resin film that is crosslinked and cured by heat or ultraviolet rays is frequently used for the hard coat layer. At that time, the polyester film has an easy-adhesion layer to improve the adhesion to the hard coat layer. A laminated layer is usually used (see Patent Document 3).

On the other hand, in large-screen flat-screen TVs such as PDPs, shielding of electromagnetic waves that may affect the human body and equipment, shielding of near infrared rays that may cause malfunction of the remote control, and emission spectrum to prevent color purity deterioration. An optical filter having a plurality of functions such as shielding of non-effective wavelength visible light, antistatic, and antireflection is formed or installed on the front surface of the image display surface. Here, a film provided with a resin layer containing an organic dye compound that efficiently absorbs near-infrared rays and visible light having an ineffective wavelength for improving color purity is used.
Acrylic resin is often used for this resin layer because it has good transparency and weather resistance. After coating the film with a paint prepared by dissolving an acrylic resin and an organic dye compound in an organic solvent, the resin layer is dried. The method used as an optical film is taken (refer patent document 4, 5, 6, 7).

In addition, a resin layer that absorbs ineffective wavelengths in the near infrared and visible light is provided on the opposite surface of the antireflection film, and the integration of functions is proposed to reduce the number of parts and the bonding process. (See Patent Document 8).
JP 2001-201607 A JP 2001-129931 A JP 2005-343118 A Japanese Patent No. 3145309 Japanese Patent No. 3308545 JP 58-153904 A JP 2002-40233 A Japanese Patent Laid-Open No. 10-156991

In the case of an antireflection film using a polyester film as the base material, the refractive index of the hard coat layer made of an ultraviolet curable acrylic resin is about 1.52, and the refractive index of the polyester film is about 1.65. For this reason, interference fringes are generated at the interface due to this large refractive index difference. When the antireflection film in which the interference fringes appear strongly is provided on the surface of the image display device, the quality of the image display device may be deteriorated and the product value may be lowered. As means for suppressing this interference fringe, by making the refractive index of the easy-adhesion layer used for improving the adhesion with the hard coat layer a polyester resin layer having a refractive index of about 1.58, it is possible to achieve both improvement in adhesion and suppression of interference fringe. Means were adopted.

  On the other hand, when an acrylic resin layer containing an organic dye compound is laminated on the opposite side of the antireflection film for functional integration, the polyester film is easily bonded to improve adhesion to the acrylic resin. Unlike the method of applying a monomer or oligomer, cross-linking and curing, and stacking acrylic resin like the hard coat layer described above, pre-polymerized acrylic resin is used. In the case of dissolving in a solvent to form a paint and laminating by coating and drying, there is a problem that an easily adhesive layer made of a polyester resin cannot provide sufficient adhesive strength, and the laminated film easily peels off. Of course, means such as ultraviolet curing are not preferred because the organic dye compound may be decomposed. Therefore, the easy adhesion layer on the side where the acrylic resin layer containing the organic dye compound is laminated has an acrylic having sufficient adhesive strength for both the polyester film as the base material and the acrylic resin layer containing the organic dye compound. Resin has been designed and used.

  However, since the refractive index of the acrylic resin layer containing the organic dye compound is about 1.50, and the refractive index of the acrylic resin-based easy-adhesion layer is also about 1.50, the acrylic resin containing the organic dye compound When the layers are laminated, interference fringes appear very strongly due to the difference in refractive index with the polyester film, greatly reducing the quality of the image display device, and further, at the interface of the acrylic resin layer containing the polyester film and the organic dye compound. It became clear that there was a problem that the antireflection performance of the entire optical film was lowered due to an increase in reflection from the back side of the optical film due to the strong reflection.

  In addition, by using an acrylic resin in which inorganic oxide fine particles with a high refractive index such as titanium oxide are dispersed in such an easy-adhesion layer, it is an attempt to achieve both improvement in adhesion, suppression of interference fringes, and improvement in antireflection performance. In order to obtain sufficient performance, it is necessary to disperse the fine particles of the inorganic oxide at a high concentration. In this case, there is a problem that it is difficult to form an easy-adhesion layer during the process of forming the polyester film. .

  In view of the background of the prior art, the present invention provides an acrylic resin layer containing an organic dye compound having a near infrared absorption or wavelength selective absorption function in the visible light region on the surface opposite to the antireflection layer of the antireflection film. In the optical film in which the organic dye compound-containing acrylic resin layer is laminated, the adhesive property of the organic dye compound-containing acrylic resin layer is excellent, and interference fringe generation prevention and antireflection properties at the interface between the organic dye compound-containing acrylic resin layer and the polyester film are improved. It is intended to provide an excellent optical film. According to such an optical film, it is possible to provide an optical filter having excellent interference fringe prevention properties and antireflection properties, particularly those that are effectively used for large-screen thin image display devices such as PDP and SED. Can be provided.

  In order to solve the above problems, the present invention employs the following means. That is, in the optical film of the present invention, a hard coat layer and an antireflection layer are laminated in this order from the polyester film side on one side of the polyester film, and at least one kind of organic film is formed on the other side of the polyester film. In an optical film in which an acrylic resin layer containing a dye compound is laminated, an easy-adhesion layer having a phase separation structure in the thickness direction is provided between the polyester film and the organic dye compound-containing acrylic resin layer. However, the polyester film side is composed of a phase mainly composed of a polyester resin, the organic dye compound-containing acrylic resin layer side is composed of a phase mainly composed of an acrylic resin, and both phases of the easy-adhesion layer are included. The separation interface is characterized in that a mixed region of each phase exists.

A preferred embodiment of such an optical film is
(1) The content ratio of the polyester resin component in the easy-adhesion layer is 20% by mass or more and less than 60% by mass,
(2) The antireflection layer comprises two layers of a high refractive index layer and a low refractive index layer, the refractive index of the low refractive index layer is 1.42 or less, and the low refractive index layer and the high refractive index layer The refractive index difference is 0.15 or more, the thickness d _H of the high refractive index layer of the antireflection layer is in the range of 105 to 160 nm, and the thickness d _L of the low refractive index layer is in the range of 75 to 110 nm. And the ratio d _H / d _L of the thickness d _H of the high refractive index layer and the thickness d _L of the low refractive index layer is in the range of 1.0 to 1.9.
(3) The organic dye compound is a near-infrared absorbing dye, the transmittance at a wavelength of 850 nm is 15% or less, and the transmittance at a wavelength of 950 nm to 1150 nm is 10% or less,
(4) The organic dye compound is a wavelength selective absorption dye for visible light, and has a maximum absorption wavelength in a wavelength range of 580 to 610 nm.
(5) The organic dye compound is a wavelength selective absorption dye for visible light, and has a maximum absorption wavelength in a wavelength range of 570 to 580 nm.

  The optical filter for plasma display of the present invention is characterized by comprising the optical film of (4) of the above preferred embodiment, and the optical filter for surface electric field display of the present invention is of the above preferred embodiment. (5) It is characterized by being comprised with the optical film.

  According to the present invention, the adhesion between the polyester film and the acrylic resin layer containing the organic dye compound is excellent, the generation of interference fringes at the interface is suppressed, and the reflection from the back side of the film is also suppressed. An optical film having excellent antireflection performance can be obtained. Furthermore, according to a preferred aspect of the present invention, in the antireflection layer consisting of two layers of the high refractive index layer and the low refractive index layer, the minimum reflectance of the surface is low and a flatter reflection spectrum is obtained, and the reflection color Can be obtained as an optical film with a neutral color and less glare. Moreover, it can be set as the multifunctional optical film provided with the near-infrared absorptivity and / or the wavelength selective absorptivity which can absorb the visible light of a specific wavelength sharply in the surface on the opposite side to an antireflection layer. By providing an optical filter with this optical film on the surface layer on the image display surface or its front surface, the reflection of external light is suppressed to improve visibility, and the color purity is improved to expand the color reproduction range. It is possible to provide an image display device that can obtain a corrected image and prevent malfunction of the remote controller.

  In the present invention, an acrylic resin layer containing an organic dye compound having a near-infrared absorption or wavelength selective absorption function in the visible light region is laminated on the surface opposite to the antireflection layer of the antireflection film. An optical film that has excellent adhesion of the organic dye compound-containing acrylic resin layer and excellent anti-interference fringe and antireflection properties at the interface between the organic dye compound-containing acrylic resin layer and the polyester film. An optical film in which an acryl resin layer containing an organic dye compound having a near-infrared absorption or wavelength selective absorption function in the visible light region is laminated on the surface opposite to the antireflection layer of the antireflection film. In the above, when the organic dye compound-containing acrylic resin layer was laminated using a specific easy adhesion layer, that is, the polyester film It is rich in the polyester resin component, and the acrylic resin layer is richly blended on the acrylic resin layer side, and the intermediate layer is provided with an easy-adhesion layer having a phase separation structure as a mixed layer of both resin components, and laminated. , It has been clarified that such problems can be solved all at once.

  The optical film of this invention is demonstrated using drawing.

  FIG. 1 is a schematic cross-sectional view showing an example of a preferred embodiment of the optical film of the present invention. As an example of a preferred embodiment of the present invention, a hard coat layer (4) is laminated on one surface of a polyester base film (6), and a high refractive index layer (3) and a low refractive index layer ( An antireflection layer (11) comprising 2) is laminated. Furthermore, a protective film (1) for preventing the antireflection layer from being scratched or soiled in the production process may be laminated thereon. It is preferable that an easy-adhesion layer (5) is provided between the base film (6) and the hard coat layer in order to improve the adhesion of the hard coat layer. Alternatively, in the process of forming the polyester base film (6), instead of forming the easy adhesion layer (5), the hard coat layer (4) directly formed is also excellent in adhesion and interference fringe suppression. preferable.

  On the other hand, an easy-adhesion layer (7) having a phase separation structure is formed on the opposite surface of the base film (6), and an organic dye compound that absorbs near-infrared rays and / or visible light having a specific wavelength thereon. The resin layer (8) containing is laminated. Furthermore, a pressure-sensitive adhesive layer (9) and a release film (10) for bonding with other optical filter members such as semi-tempered glass or an electromagnetic wave shielding film or an antistatic film are laminated thereon. An organic dye compound that absorbs visible light having a specific wavelength may be contained in the adhesive layer (9).

  As the base film used in the optical film of the present invention, a polyester film that can be melt-formed is used because of its excellent transparency, mechanical strength, dimensional stability, etc., high light transmittance, and low haze. The

  As such a polyester film, a film having a total light transmittance of preferably 80% or more, more preferably 85% or more is used. Further, the base film, that is, the haze value of the polyester film is preferably 3% or less, more preferably 1% or less. Satisfying both of these conditions is more preferable in terms of sharpness when used as a member for an image display device. Further, the upper limit of the total light transmittance is about 99.5%, and the lower limit of the haze value is about 0.1%. Here, the total light transmittance is a value measured based on JIS K7361-1, and the haze is a value measured based on JIS K7136.

  As the polyester constituting such a polyester film, polyethylene terephthalate, polyethylene naphthalate, polypropylene terephthalate, polybutylene terephthalate, polypropylene naphthalate and the like can be used. Two or more of these may be mixed. In addition, these may be a polyester copolymerized with other dicarboxylic acid components and diol components, but the copolymerization ratio is preferably 25% or more in the degree of crystallinity in a film in which crystal orientation is completed. More preferably, the range is 30% or more, and more preferably 35% or more. When the crystallinity is less than 25%, dimensional stability and mechanical strength tend to be insufficient. The degree of crystallinity can be measured by a Raman spectrum analysis method.

  Such a polyester film is not limited to a single film, and may be a composite film having a laminated structure of two or more layers. As such a composite film, for example, a composite film that is substantially free of particles in the inner layer portion and provided with a layer containing particles in the surface layer portion, has coarse particles in the inner layer portion, and fine in the surface layer portion. Examples thereof include a composite film containing particles and a composite film having a layer in which the inner layer portion contains fine bubbles. In the composite film, the polymer constituting the inner layer portion and the surface layer portion may be a chemically different polymer or the same kind of polymer.

  Such a polyester film is sufficient if the film has sufficient thermal stability, particularly dimensional stability and mechanical strength, and has good flatness. From such a viewpoint, the polyester film is a crystal oriented film by biaxial stretching. Those are preferably used. Here, the crystal orientation by biaxial stretching is unstretched, that is, the polyester film before completion of crystal orientation is preferably stretched about 2.5 to 5 times in the longitudinal direction and the width direction, respectively. Thereafter, the crystal orientation is completed by heat treatment, and it indicates a biaxial orientation pattern by wide-angle X-ray diffraction.

  The thickness of the polyester film is preferably 10 to 500 μm, more preferably 20 to 300 μm, from the viewpoint of mechanical strength and handling properties.

  Such a polyester film may contain various additives, resin compositions, cross-linking agents and the like within a range that does not impair the effects of the present invention. For example, antioxidants, heat stabilizers, UV absorbers, organic and inorganic particles, pigments, dyes, antistatic agents, nucleating agents, acrylic resins, polyester resins, urethane resins, polyolefin resins, polycarbonate resins, alkyd resins, epoxy resins , Urea resin, phenol resin, silicone resin, rubber resin, wax composition, melamine crosslinking agent, oxazoline crosslinking agent, methylolated, alkylolized urea crosslinking agent, acrylamide, polyamide, epoxy resin, isocyanate compound , Aziridine compounds, various silane coupling agents, various titanate coupling agents, and the like.

  Among these, an ultraviolet absorber is preferably used because it can prevent photodegradation of the organic dye compound. Examples of such UV absorbers include triazole, triazine, benzophenone, and amine UV absorbers. Among these, triazine UV absorbers and amine UV absorbers are preferably used. In particular, triazine-based ultraviolet absorbers are preferable, and among them, 2 (4,6-diphenyl-1,3,5-triazin-2-yl) -5-[(hexyl) oxy] -phenol is particularly preferable. Films using this UV absorber are less colored (yellowish), excellent in transparency, less sublimation, decomposition, bleed-out, etc. of the UV absorber and are less likely to cause problems in the film forming process. There is.

  Moreover, as the inorganic particles, for example, when silica, colloidal silica, alumina, alumina sol, kaolin, talc, mica, calcium carbonate, barium sulfate, carbon black, zeolite, titanium oxide, metal fine powder, etc. are added, Since slipperiness, scratch resistance, etc. improve, it is especially preferable. The average particle diameter of such inorganic particles is preferably 0.005 to 5 μm, more preferably about 0.05 to 1 μm. The particle diameter here is a value obtained using a laser diffraction particle size distribution measuring apparatus. The average particle size is 50% distributed particle size. The 50% distribution particle size refers to the particle size where the particle size distribution is 50%, and the average particle size refers to this particle size unless otherwise specified. Moreover, the addition amount of the inorganic particles is preferably 0.05 to 20 parts by mass, more preferably 0.1 to 10 parts by mass in 100 parts by mass of the polyester film. Here, the particle diameter is a value measured based on JIS Z8825-1.

  The polyester film that is such a base film is one in which an easy-adhesion layer is formed for the purpose of improving the adhesion with a hard coat layer and an acrylic resin layer containing an organic dye compound. The easy-adhesion layer as used herein refers to a film-like layer that is formed on the polyester film in a laminated structure, and usually a method of forming simultaneously with film formation in the film formation process of the polyester film is preferably used. It is done. In this case, the easy-adhesion layer is obtained by melt-extrusion of polyester, longitudinally stretching and forming a film, and then applying a coating solution comprising the resin composition for the easy-adhesion layer on one or both sides of the polyester film. Preferably, the film is formed by transverse stretching with a film after the coating solution is applied, and then dried and cured. As such a coating solution, it is preferable to use a constituent resin of an easy-adhesion layer, which will be described later, dissolved or dispersed in water. Therefore, the constituent resin of the easy-adhesion layer is preferably water-dispersible.

  Various coating methods such as a reverse coating method, a gravure coating method, a rod coating method, a bar coating method, a Mayer bar coating method, a die coating method, and a spray coating method can be used as the coating method on the polyester film. . In consideration of the uniformity and adhesion of the coating film, it is preferable to subject the polyester film surface to corona discharge before coating.

  In the present invention, the component constituting the easy-adhesion layer is not particularly limited as long as it has sufficient adhesion to the polyester film and the hard coat layer, or the polyester film and the organic dye compound-containing acrylic resin layer. Epoxy resin, alkyd resin, acrylic resin, urea resin, urethane resin and the like can be suitably used. In particular, from the viewpoint of adhesiveness, it is more preferable to use a resin selected from a polyester resin, an acrylic resin, and a urethane resin. A polyester resin and an acrylic resin, a polyester resin and a urethane resin, or a combination of an acrylic resin and a urethane resin may be used. Good.

  Here, as a constituent component of the easy adhesion layer used on the hard coat layer forming side, a polyester resin is more preferable. As the first reason, since the polyester film is stretched as described above, the refractive index thereof is higher than that of the unstretched state of the polyester and is about 1.65. When applying an easy-adhesion layer on it, the difference in refractive index at the interface between the film and the easy-adhesion layer can be reduced by including a non-oriented polyester resin having a refractive index close to that of a biaxially oriented polyester film. it can. In order to suppress the occurrence of interference fringes at the interface between the polyester film and the hard coat layer, the refractive index of the easy-adhesion layer preferably satisfies the following formula (1).

(Refractive index of easy adhesion layer) = {(Refractive index of polyester film) × (Refractive index of hard coat layer)} ^1/2 ± 0.03 (1).

  Here, for example, if the refractive index of the biaxially stretched polyester film is 1.65 and the refractive index of the hard coat layer is 1.52, the refractive index of the non-oriented polyester resin used for the easy-adhesion layer is (1) From the formula, 1.55 to 1.61 is a preferable range. The second reason why a polyester resin is preferable for the easy-adhesion layer is that it is more excellent in adhesion to a polyester film than other resins. However, when the adhesion with the hard coat layer is insufficient only with the polyester resin, it is preferable to use it as a constituent component of the easy-adhesion layer having a phase separation structure described later.

  The thickness of the easy-adhesion layer on the hard coat layer side is preferably 20 nm or more and 200 nm or less, more preferably 50 nm or more and 150 nm or less in order to bring out the effect of suppressing interference fringes.

  In the present invention, the water-dispersible polyester resin used for the easy-adhesion layer is one having an acid value of 5 mg / g or more and less than 20 mg / g, more preferably 10 mg / g or more and 18 mg / g or less. Used because of its superiority. When the polyester resin has an acid value of less than 5 mg / g, the polyester resin cannot be dispersed in water. When the acid value is 20 mg / g or more, the hydrophilicity of the polyester resin is too high, and it adheres under high temperature and high humidity. This is not preferable because the properties are lowered. Here, the acid value is a value measured by the method described in JIS K0070.

  In order to maintain the adhesive strength at high temperature and high humidity, the glass transition point of the water-dispersible polyester resin in the present invention is preferably 30 ° C. or higher and 60 ° C. or lower, more preferably 35 ° C. or higher and 55 ° C. It is as follows. By setting the glass transition point to be equal to or higher than the above lower limit value, it is possible to prevent high-temperature deformation, and it is possible to avoid the breakage of the easily adhesive layer. Moreover, if it is below the said upper limit, the adhesive force with a polyester film can be kept favorable. Here, the glass transition point is a value measured by the method described in JIS K7121.

  As the water-dispersible polyester resin, in order to increase the water-dispersibility, it is possible to use a resin obtained by copolymerizing a compound containing a sulfonate group or a compound containing a carboxylate group with a resin. If it is strongly acidic and contains such an acid group, it tends to be difficult to maintain high-temperature moisture resistance due to moisture absorption. Therefore, a carboxylic acid base that is weakly acidic is preferably used.

  Next, what added the acrylic resin to the above-mentioned polyester resin is used for the easily bonding layer used for the organic pigment compound containing acrylic resin layer formation side.

  In other words, after the polyester resin dispersion solution is applied, a method of separately applying an acrylic resin dispersion solution may be used, but this is difficult to cause a phase separation phenomenon in each coating solution, and further, when the intermediate resin is dried in the middle The phase separation phenomenon does not occur, and a weakly adhesive layer is formed. Therefore, the most suitable method for providing an easy-adhesive layer in the present invention is to apply a mixed dispersion solution of polyester resin and acrylic resin at one time. This is a method (simultaneous mixed application method). In addition to cost advantages, this method uses acrylic resin, which is a low solubility parameter substance on the surface side, and high solubility parameter on the polyester film substrate side due to the phase separation phenomenon due to the difference in solubility parameter of each resin. The polyester resin as a material is selectively coordinated by mutual exclusion, and a refractive index permutation that is naturally advantageous with respect to the thickness direction of the easy-adhesion layer is formed.

  In this phase separation structure, the refractive index of the phase mainly composed of non-oriented polyester resin satisfies the following formula (2): Interference at the interface between the polyester film and the acrylic resin layer containing the organic dye compound This is preferable in order to suppress the generation of fringes.

(Refractive index of phase containing polyester resin as main component) = {(Refractive index of polyester film) × (Refractive index of organic dye compound-containing acrylic resin layer)} ^1/2 ± 0.03 (2).

  Here, for example, if the refractive index of the biaxially stretched polyester film is 1.65 and the refractive index of the organic dye compound-containing acrylic resin layer is 1.50, the refractive index of the non-oriented polyester resin used for the easy adhesion layer From (2), 1.54 to 1.60 is a preferred range.

  In addition, when the acrylic resin is applied to the surface layer, the polyester resin can make use of the adhesive strength of the acrylic resin with respect to a material having poor adhesion. In the above-mentioned simultaneous mixed coating method, a clear phase separation structure can be formed if sufficient drying time is taken, whereas if it is dried in a short time, the phase separation cannot be completed and the mixed region remains. A variety of variations can be added. Here, in order to improve the adhesion between the phase mainly composed of the polyester resin in the easy-adhesion layer and the phase mainly composed of the acrylic resin, and to prevent peeling at the interface, a mixed region is formed at the interface. It is extremely effective to leave.

  If the total thickness of the easy-adhesion layer having such a phase separation structure is too thin, poor adhesion may occur, and if it is too thick, problems of blocking and scraping may occur, preferably 20 nm or more and 200 nm or less, more preferably 50 nm or more. It is good that it is 150 nm or less.

  As for the mixing ratio of the polyester resin, the acrylic resin and the crosslinking agent contained in the easy-adhesion layer having such a phase separation structure, it is preferable to increase the polyester resin in order to prevent interference fringes and reduce the surface reflectance. If the amount is too small, the adhesiveness with the organic dye compound-containing acrylic resin layer is lowered, which is not preferable. Therefore, in the present invention, the mixing ratio of the polyester resin and the acrylic resin is preferably within a range of 1/4 to 2/1, more preferably 1/3 to 1/1 in terms of the mass ratio of the acrylic resin / polyester resin. 1.

  Furthermore, in consideration of the addition amount of a crosslinking agent described later, and taking into consideration adhesion and prevention of interference fringes and reduction of surface reflectance, the content ratio of the polyester resin in the easy-adhesion layer having such a phase separation structure is 20% by mass. It is preferable that it is more than 60 mass%, and the range of 33 mass% or more and 55 mass% or less is more preferable.

  Further, in the easy-adhesion layer having such a phase separation structure, the thickness of each resin phase, that is, a phase having a polyester resin as a main constituent component, a phase having an acrylic resin as a main constituent component, and a mixed region of the three phases are as follows: When the total thickness of the easy-adhesion layer is 1, the thickness of the phase mainly comprising the polyester resin is 0.33 or more and 0.8 or less, more preferably 0.5 or more and 0.75 or less, and the acrylic resin The thickness of the phase having the main constituent component is 0.2 or more and 0.67 or less, more preferably 0.25 or more and 0.5 or less, and the thickness of the mixed region of both is 0.01 or more and 0.3 or less. Preferably there is.

  In the present invention, the initial adhesion between the easy-adhesion layer having such a phase separation structure and the organic dye compound-containing acrylic resin layer is the adhesion by the cross-cut method of the coating film described in JIS K5600-5-6. In the test, it is preferable that the edge of the cut is completely smooth and has an adhesion (corresponding to a classification of 0) that does not peel off to the eyes of any lattice. Those in which peeling is observed at the intersection of the cuts (corresponding to classifications 1 to 5) are not preferable because not only the initial adhesiveness but also the adhesiveness under high temperature and high humidity are insufficient.

  In the present invention, the polyester resin used in the easy-adhesion layer having such a phase separation structure is preferably one having an ester bond in the main chain or side chain and obtained by polycondensation from a dicarboxylic acid and a diol.

  As the carboxylic acid component constituting the polyester resin, aromatic, aliphatic, and alicyclic dicarboxylic acids and trivalent or higher polyvalent carboxylic acids can be used.

  Examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, orthophthalic acid, phthalic acid, 2,5-dimethylterephthalic acid, 1,4-naphthalenedicarboxylic acid, biphenyldicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1, 2-bisphenoxyethane-p, p′-dicarboxylic acid, phenylindanedicarboxylic acid, and the like can be used. These aromatic dicarboxylic acids are preferably 30 mol% or more, more preferably 35 mol% or more, and most preferably 40 mol% or more of the total dicarboxylic acid component in terms of the strength and heat resistance of the easy-adhesion layer. It is good to use.

  Examples of the aliphatic and alicyclic dicarboxylic acids include succinic acid, adipic acid, sebacic acid, azelaic acid, dodecanedioic acid, dimer acid, 1,3-cyclopentanedicarboxylic acid, and 1,2-cyclohexanedicarboxylic acid. 1,4-cyclohexanedicarboxylic acid and the like, and ester-forming derivatives thereof can be used.

  Examples of the glycol component constituting the polyester resin include ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5- Pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 2,4-dimethyl-2-ethylhexane-1 , 3-diol, neopentyl glycol, 2-ethyl-2-butyl-1,3-propanediol, 2-ethyl-2-isobutyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2,2,4-trimethyl-1,6-hexanedioe 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, 4,4′-thiodim Phenol, bisphenol A, 4,4′-methylenediphenol, 4,4 ′-(2-norbornylidene) diphenol, 4,4′-dihydroxybiphenol, o-, m-, and p-dihydroxybenzene, 4,4 '-Isopropylidenephenol, 4,4'-isopropylidenebin diol, cyclopentane-1,2-diol, cyclohexane-1,2-diol, cyclohexane-1,4-diol, and the like can be used.

  In order to make the polyester resin water-soluble or water-dispersible, it is preferable to copolymerize a compound containing a carboxylate group. Examples of the compound containing such a carboxylate group include trimellitic acid, trimellitic anhydride, pyromellitic acid, pyromellitic anhydride, 4-methylcyclohexene-1,2,3-tricarboxylic acid, trimesic acid, 1,2 , 3,4-Butanetetracarboxylic acid, 1,2,3,4-pentanetetracarboxylic acid, 3,3 ′, 4,4′-benzophenonetetracarboxylic acid, 5- (2,5-dioxotetrahydrofurfuryl) ) -3-methyl-3-cyclohexene-1,2-dicarboxylic acid, 5- (2,5-dioxotetrahydrofurfuryl) -3-cyclohexene-1,2-dicarboxylic acid, cyclopentanetetracarboxylic acid, 2, 3,6,7-naphthalenetetracarboxylic acid, 1,2,5,6-naphthalenetetracarboxylic acid, ethylene glycol bistrimer 2,2 ′, 3,3′-diphenyltetracarboxylic acid, thiophene-2,3,4,5-tetracarboxylic acid, ethylenetetracarboxylic acid, or the like, or alkali metal salts or alkaline earth metal salts thereof Ammonium salts can be used, but are not limited thereto.

  Moreover, as a polyester resin used for the easily bonding layer which has such a phase-separation structure, a modified polyester copolymer, for example, a block copolymer modified with acrylic, urethane, epoxy, etc., a graft copolymer, etc. are also possible.

  About the molecular weight of the polyester resin used for the easily bonding layer which has this phase-separation structure, in order to make adhesiveness and water dispersibility compatible, it is preferable to exist in the range of 500-40000, and in the range of 1000-30000. More preferably.

  In the present invention, the acrylic resin used as a constituent component of the easy-adhesion layer having such a phase separation structure is, for example, an alkyl acrylate, an alkyl methacrylate (as the alkyl group, a methyl group, an ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, 2-ethylhexyl group, lauryl group, stearyl group, cyclohexyl group, phenyl group, benzyl group, phenylethyl group, etc.), 2-hydroxy Hydroxy group-containing monomers such as ethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, acrylamide, methacrylamide, N-methyl acrylamide, N-methyl methacryl Amide group-containing monomers such as amide, N-methylolacrylamide, N-methylolmethacrylamide, N, N-dimethylolacrylamide, N-methoxymethylacrylamide, N-methoxymethylmethacrylamide, N-phenylacrylamide, N, N-diethylamino Amino group-containing monomers such as ethyl acrylate and N, N-diethylaminoethyl methacrylate, epoxy group-containing monomers such as glycidyl acrylate and glycidyl methacrylate, acrylic acid, methacrylic acid and salts thereof (lithium salt, sodium salt, potassium salt, etc.), etc. A monomer containing a carboxyl group or a salt thereof can be used, and copolymerization is performed using one or two or more of these monomers.

  Furthermore, they can also be copolymerized with other types of monomers. Such other types of monomers include, for example, epoxy group-containing monomers such as allyl glycidyl ether, sulfonic acid groups such as styrene sulfonic acid, vinyl sulfonic acid and salts thereof (lithium salt, sodium salt, potassium salt, ammonium salt, etc.). Or a monomer containing a salt thereof, a monomer containing a carboxyl group or a salt thereof such as crotonic acid, itaconic acid, maleic acid, fumaric acid and salts thereof (lithium salt, sodium salt, potassium salt, ammonium salt, etc.), anhydrous Monomers containing acid anhydrides such as maleic acid and itaconic anhydride, vinyl isocyanate, allyl isocyanate, styrene, vinyl methyl ether, vinyl ethyl ether, vinyl trisalkoxysilane, alkyl maleic acid monoester, alkyl fumar Acid monoester, acrylonitrile, methacrylonitrile, alkyl itaconic acid monoester, vinylidene chloride, vinyl acetate, etc. can be used vinyl chloride.

  Other acrylic resins that can be used for the easy-adhesion layer having such a phase separation structure include modified acrylic copolymers, such as block copolymers modified with polyester, urethane, epoxy, etc., graft copolymers, etc. Is also possible.

  The acid value of the acrylic resin used for the easy-adhesion layer having such a phase separation structure is preferably less than 20 mg / g in the same manner as the polyester resin described above from the viewpoint of high temperature and humidity resistance. However, since acrylic resin emulsions are generally easier to disperse in water than polyester resin emulsions, many of them have an acid value of less than 20 mg / g.

  Although the glass transition point (henceforth Tg) of the acrylic resin used for the easily bonding layer which has this phase-separation structure is not specifically limited, Preferably it is 0-90 degreeC, More preferably, it is 10-80 degreeC. When an acrylic resin having a low Tg is used, the heat-resistant adhesion tends to be inferior. On the other hand, when it is too high, the film forming property may be inferior, which is not preferable. The molecular weight of the acrylic resin is preferably 100,000 or more, more preferably 300,000 or more from the viewpoint of adhesiveness.

  In the easy-adhesion layer having such a phase separation structure of the present invention, it is possible to dissolve, emulsify or suspend an acrylic resin in water and use it as a water-based acrylic resin in the same manner as a polyester resin. Necessary in terms. Such water-based acrylic resins are copolymerized with monomers having a hydrophilic group (such as acrylic acid, methacrylic acid, acrylamide, vinyl sulfonic acid and salts thereof), emulsion polymerization using reactive emulsifiers and surfactants, and suspension polymerization. It can be prepared by a method such as turbid polymerization or soap-free polymerization.

  Furthermore, in the easy-adhesion layer having such a phase separation structure, it is preferable from the viewpoint of improving adhesiveness that the above-mentioned resin composition contains a cross-linking agent to cross-link the easy-adhesion layer. The crosslinking agent used here is particularly limited as long as it can undergo a crosslinking reaction with a functional group present in the resin constituting the easy-adhesion layer, for example, a hydroxyl group, a carboxyl group, a methylol group, an amide group, or the like. Not melamine-based crosslinking agent, oxazoline-based crosslinking agent, isocyanate-based crosslinking agent, aziridine-based crosslinking agent, epoxy-based crosslinking agent, methylolized or alkylolized urea-based, acrylamide-based, polyamide-based resin, various silane cups A ring agent, various titanate coupling agents, and the like can be used. In particular, a melamine crosslinking agent can be suitably used from the viewpoint of compatibility with a resin, adhesiveness, and the like.

  Such a melamine-based crosslinking agent is not particularly limited, but a melamine, a methylolated melamine derivative obtained by condensing melamine and formaldehyde, a compound partially or completely etherified by reacting a methylolated melamine with a lower alcohol, and These mixtures can be used. Moreover, as such a melamine type crosslinking agent, any of the condensate which consists of a monomer, a dimer or more multimer may be sufficient, and these mixtures may be sufficient. Moreover, as a lower alcohol used for the said etherification, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butanol, isobutanol, etc. can be used.

  Among these crosslinking agents, those most preferably employed are those having an imino group, a methylol group, or an alkoxymethyl group such as a methoxymethyl group or a butoxymethyl group in one molecule, an imino group type methylated melamine resin, or a methylol. Examples thereof include a base type melamine resin, a methylol group type methylated melamine resin, and a completely alkyl type methylated melamine resin. Of these, methylolated melamine resin is most preferably employed. Further, an acidic catalyst such as p-toluenesulfonic acid may be used in order to accelerate the thermal curing of the melamine-based crosslinking agent.

  Furthermore, the use of an oxazoline-based cross-linking agent is also preferable from the viewpoint of maintaining adhesiveness in a high temperature and high humidity environment. Such an oxazoline-based cross-linking agent is more effective than other cross-linking agents to deactivate the carboxylate base that contributes to the water dispersion of the polyester or acrylic resin and lower the moisture absorption. Such an oxazoline-based cross-linking agent may be used alone, but is more preferably used in combination with the melamine-based cross-linking agent.

  The oxazoline-based crosslinking agent used in the present invention is not particularly limited as long as it has an oxazoline group as a functional group in the compound, but includes at least one monomer containing an oxazoline group, and What consists of an oxazoline group containing copolymer obtained by copolymerizing at least 1 type of another monomer is preferable.

  Examples of the monomer containing such an oxazoline group include 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline. 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-ethyl-2-oxazoline, and the like, and one or a mixture of two or more of them can also be used. Of these, 2-isopropenyl-2-oxazoline is preferred because it is easily available industrially.

  The addition amount of the crosslinking agent to the resin composition constituting the easy-adhesion layer having such a phase separation structure of the present invention is preferably 10 parts by mass or more and 50 parts by mass or less of the crosslinking agent component with respect to 100 parts by mass of the resin component. It is more preferable to add in the range of 20 parts by mass or more and 40 parts by mass or less. When the addition amount of the crosslinking agent is larger than the above range, blocking is likely to occur, and when it is less than the above range, the adhesiveness is deteriorated, which is not preferable.

  Furthermore, various additives such as an antioxidant, a heat stabilizer, a weather stabilizer, an ultraviolet absorber, an organic lubricant, an organic or inorganic fine particle, a filler, an antistatic agent, A nucleating agent or the like may be blended. In particular, those in which inorganic particles are added to such an extent that the transparency of the whole film is not impaired are more preferable because the slipperiness and blocking resistance are improved. In this case, as the inorganic particles to be added, at least one selected from silica, colloidal silica, alumina, alumina sol, kaolin, talc, mica, and calcium carbonate can be used.

  The optical film of the present invention is obtained by laminating a hard coat layer and an antireflection layer on the easy adhesion layer composed of the above-described polyester resin, and then organically depositing on the easy adhesion layer having a phase separation structure on the opposite side. It is formed by a configuration in which a dye compound-containing acrylic resin layer is laminated. By doing so, it was possible to provide an excellent optical film that does not cause photodegradation of the organic dye because it does not expose the organic dye to the ultraviolet rays used when forming the cured film of the hard coat layer or the antireflection layer. is there.

  In the present invention, the hard of the hard coat layer means that the hardness is higher than that of the polyester film substrate. In practice, the hard coat layer of the present invention preferably has a pencil hardness of 2H or more. Here, the pencil hardness is a value measured based on JIS K5600-5-4.

  The hard coat layer is not particularly limited, but an acrylic resin film obtained by coating a composition containing a (meth) acrylate compound on the easy-adhesion layer and polymerizing and curing by heat, ultraviolet rays, or the like. Can be mentioned. Examples of (meth) acrylate compounds used in such hard coat layers include methyl (meth) acrylate, n-butyl (meth) acrylate, polyester (meth) acrylate, lauryl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxy A monofunctional acrylate compound such as propyl (meth) acrylate, and a polyfunctional (meth) acrylate compound having two or more (meth) acryloyl groups in the molecule improve the solvent resistance and the like. preferable. Specific examples of the polyfunctional (meth) acrylate include pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (Meth) acrylate, dipentaerythritol hexa (meth) acrylate, trimethylolpropane tri (meth) acrylate and the like. These monomers may be used alone or in combination of two or more. Furthermore, fine particles such as silica and reactive silicon compounds such as tetraethoxysilane may be included. Among these, from the viewpoint of productivity and hardness, a composition containing an ultraviolet curable polyfunctional (meth) acrylate is preferably used.

  In the hard coat layer of the present invention, various additives can be blended as necessary. For example, stabilizers such as antioxidants, light stabilizers, ultraviolet absorbers, surfactants, leveling agents, antistatic agents, and the like can be used.

  Use of such a leveling agent is preferable because the formed hard coat layer is smoothed. Examples of such leveling agents include silicone leveling agents, acrylic leveling agents, and fluorine leveling agents, and silicone leveling agents are particularly effective when added in a small amount. As such a silicone leveling agent, it is preferable to apply an acrylic leveling agent that does not inhibit the adhesion with the antireflection layer on the hard coat layer. As such a leveling agent, “ARUFON-UP1000 series, UH2000 series, UC3000 series (trade name): manufactured by Toagosei Co., Ltd.” and the like can be preferably used. The leveling agent is preferably added in an amount of 0.01 to 5 parts by mass with respect to 100 parts by mass of the hard coat composition.

  The thickness of the hard coat layer is preferably 0.1 μm to 30 μm, more preferably 1 μm to 15 μm. When the thickness of the hard coat layer is less than 0.1 μm, even if it is sufficiently cured, it is too thin, so that the surface hardness is not sufficient and it tends to be easily damaged. On the other hand, when the thickness of the hard coat layer exceeds 30 μm, the cured film tends to be cracked due to stress such as bending.

  In the present invention, the antireflection layer formed on the hard coat layer is a single-layer antireflection layer in which only a low refractive index layer is formed, or a high refractive index layer and a low refractive index layer are formed in this order. A two-layer antireflection layer, a low-refractive-index layer, a high-refractive-index layer, and a three-layer anti-reflection layer in which a low-refractive-index layer is formed in this order. And a two-layer antireflection layer in which the production cost is balanced. Here, the level of the refractive index is expressed in comparison with the refractive index of the lower layer.

When the antireflection layer of the optical film of the present invention is two layers, in the regular reflection spectrum of 5 degrees at a wavelength of 400 to 700 nm,
(1) Minimum reflectance is 0.4% or less,
(2) Luminous regular reflectance is 0.6% or less,
(3) The difference between the maximum reflectance and the minimum reflectance is less than 3%,
It is preferable to satisfy all three conditions.

  If the minimum reflectance exceeds 0.4% or the luminous regular reflectance exceeds 0.5%, the antireflection is insufficient, which is not preferable. On the other hand, if the difference between the highest reflectance and the lowest reflectance exceeds 3%, the reflectance near 450 nm or around 700 nm increases, and the color tone of the reflected light is bluish or reddish. More preferably, the minimum reflectance is 0.3% or less, more preferably 0.2% or less, and the luminous regular reflectance is 0.5% or less, more preferably 0.4% or less. It is preferable from the viewpoint of antireflection. Further, it is preferable that the difference between the maximum reflectance and the minimum reflectance is less than 2.5%, and further less than 2.0%, because a flatter reflection spectrum is obtained and the color becomes neutral.

In the optical film of the present invention, a low refractive index layer and a high refractive index layer are used in order to set the minimum reflectance and the maximum reflectance of a regular reflection spectrum of 5 degrees at a wavelength of 400 to 700 nm and the reflectance difference within the above ranges. Is preferably adjusted as follows. The refractive index (n _L ) of the low refractive index layer is preferably 1.42 or less, and the refractive index difference between the low refractive index layer and the high refractive index layer is preferably 0.15 or more. Furthermore, the refractive index of the high refractive index layer _{(n H)} is preferably from 1.55 to 1.80, more preferably from 1.60 to 1.75. The refractive index of the low refractive index layer _{(n L)} is preferably from 1.23 to 1.42, more preferably from 1.34 to 1.38.

Here, the refractive index (n _L ) of the low-refractive index layer and the refractive index (n _H ) of the high-refractive index layer satisfy the following expressions (3) and (4) to lower the minimum reflectance. It is preferable because it is possible.

(N _H ) = (n _L ) × (n _G ) ^1/2 ± 0.02 (3)
(N _L ) = (n _H ) / (n _G ) ^1/2 ± 0.02 (4).

Here, (n _G ) is the refractive index of the hard coat layer, and is usually 1.45 to 1.55 in the case of the hard coat layer described above.

In the present invention, in order to obtain a flatter reflection spectrum, the product of the refractive index (n _H ) of the high refractive index layer and the thickness (d _H ) of the high refractive index layer in the above range (in the optical thickness). However, the thickness (d _H ) is preferably 1.2 to 1.7 times 1/4 of the wavelength (λ) of visible light for which reflection is to be prevented. -1.6 times are preferable. If the value of the product is less than 1.2 times, the difference between the maximum reflectance and the minimum reflectance exceeds 2.5%, which is not preferable. On the other hand, if the value of the product exceeds 1.7 times, the minimum reflectance becomes higher than 0.6%, and the antireflection performance becomes insufficient. Here, the wavelength (λ) of visible light to be prevented from being reflected is arbitrarily selected as long as it is in the visible light range, but is preferably in the range of 500 to 650 nm, and more preferably in the range of 530 to 620 nm. Is preferred.

Considering the range of the wavelength (λ) at which reflection is desired to be prevented, the optical thickness (n _H d _H ) of the high refractive index layer is preferably in the range of 165 to 276 nm, more preferably 178 to 260 nm, particularly preferably. Is in the range of 188-248 nm.

In view of the preferable range of the refractive index (n _H ) of the above-described high refractive index layer and the wavelength (λ) that is desired to prevent reflection, in order to obtain a flatter reflection spectrum in the present invention, the high refractive index layer The thickness (d _H ) is preferably 105 to 160 nm, more preferably 110 to 155 nm, and particularly preferably 115 to 150 nm.

On the other hand, the preferred range of the thickness (d _L ) of the low refractive index layer of the present invention includes the refractive index (n _L ) of the low refractive index layer and the thickness (d _L ) of the low refractive index layer in the above-mentioned range. Is preferably a thickness (d _L ) such that it is 0.7 to 1.00 times 1/4 of the wavelength (λ) of visible light to be prevented from reflecting, and more preferably 0.75 to 0.75 0.95 times is preferable. In the present invention, as described above, in order to make the thickness (d _H ) of the high refractive index layer thicker than ¼ of the wavelength (λ) of visible light to prevent reflection, the refractive index of the low refractive index layer When the product of the refractive index (n _L ) and the thickness (d _L ) of the low refractive index layer is set to a thickness that is ¼ of the wavelength (λ) of visible light that is desired to prevent reflection, the wavelength at which the minimum reflectance is obtained. Is shifted to the longer wavelength side, and therefore, it is preferable to make the thickness lower than a quarter of the wavelength (λ) of visible light to be prevented from being reflected.

Considering the range of the wavelength (λ) at which reflection is to be prevented, the optical thickness (n _L d _L ) of the low refractive index layer is preferably in the range of 96 to 163 nm, more preferably 103 to 154 nm, particularly preferably. The range is 109 to 147 nm.

In view of the preferable range of the refractive index (n _L ) of the above-described high refractive index layer and the wavelength (λ) to prevent reflection, in order to obtain a flatter reflection spectrum in the present invention, the low refractive index layer The thickness (d _L ) is preferably 75 to 110 nm, more preferably 85 to 110 nm, and particularly preferably 85 to 105 nm.

Furthermore, in order to obtain a flat reflection spectrum, the ratio (d _H / d _L ) between the thickness (d _H ) of the high refractive index layer and the thickness (d _L ) of the low refractive index layer is preferably 1 It is good to set it as 0.0-1.9, More preferably, it is 1.1-1.8, Most preferably, it is the range of 1.2-1.7. When the ratio is less than 1.0, the maximum reflectivity is higher than 2.5%, the difference between the maximum reflectivity and the minimum reflectivity exceeds 2.5%, and the reflection spectrum is V-shaped. Red and blue interference colors appear. On the other hand, when the ratio exceeds 1.9, a flat reflection spectrum can be obtained, but the minimum reflectance becomes higher than 0.6%, and the antireflection performance becomes insufficient. By controlling in this way, it is possible to reduce the minimum reflectance with a flat reflection spectrum.

  The component of the high refractive index layer of the present invention is not particularly limited, but it is a resin composition in which metal compound particles are dispersed in order to impart antistatic properties to the optical film surface. Is preferred. A (meth) acrylate compound is used for the resin component constituting the high refractive index layer. Such a (meth) acrylate compound is preferable because it radically polymerizes by irradiation with ultraviolet rays, and improves the solvent resistance and hardness of the formed film. Furthermore, the (meth) acryloyl group has two or more polyfunctional (meta) groups in the molecule. The acrylate compound is particularly preferably employed in the present invention because the solvent resistance and the like are improved. Specifically, for example, pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, glycerol tri (meth) acrylate, ethylene-modified trimethylolpropane tri (meth) acrylate, tris- (2-hydroxyethyl) ) -Trifunctional (meth) acrylate such as isocyanuric acid ester tri (meth) acrylate, tetrafunctional or higher functional such as pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate (Meth) acrylate etc. are mentioned.

  In order to improve the dispersibility of the metal compound particles, a (meth) acrylate compound having an acidic functional group such as a carboxyl group, a phosphate group, or a sulfonate group can be used as the resin component. Specifically, examples of the acidic functional group-containing monomer include unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, 2-methacryloyloxyethyl succinic acid, 2-methacryloyloxyethyl phthalic acid, and mono (2- (meta ) (Acryloyloxyethyl) acid phosphate, diphenyl-2- (meth) acryloyloxyethyl phosphate, and other phosphoric acid (meth) acrylic acid esters, 2-sulfoester (meth) acrylates, and the like. In addition, (meth) acrylate compounds having a bond with polarity such as an amide bond, a urethane bond, and an ether bond can be used.

  As the metal compound particles used for the high refractive index layer, various conductive metal oxide particles are preferably used. Particularly preferably, tin-containing antimony oxide particles (ATO), zinc-containing antimony oxide particles, tin-containing indium oxide particles (ITO), zinc oxide / aluminum oxide particles, antimony oxide particles, and the like can be used.

  The conductive metal compound particles have an average primary particle diameter (sphere equivalent diameter measured by the BET method) of preferably 0.5 μm or less, more preferably 0.001 to 0.3 μm, and particularly preferably 0. A particle size of 0.005 to 0.2 μm is used. When the average particle diameter exceeds this range, the transparency of the coating film (high refractive index layer) to be produced is lowered. When the average particle diameter is less than this range, the metal compound particles are likely to aggregate, and the resulting coating film (high refractive index layer) ) Increases. In either case, it becomes difficult to obtain a desired haze value.

  In the present invention, a conductive polymer such as polypyrrole, polythiophene, and polyaniline, an organometallic compound such as a metal alcoholate and a chelate compound, for the purpose of further improving the conductivity effect, as a component of the high refractive index layer, Further, it can be contained.

  In addition, the constituents of the high refractive index layer contain various additives such as a photopolymerization initiator, a polymerization inhibitor, a curing catalyst, an antioxidant, a dispersant, a leveling agent, and a silane coupling agent as necessary. May be. In addition, for the purpose of improving the surface hardness, alkyl silicates and hydrolysates thereof, colloidal silica, dry silica, wet silica, titanium oxide and other inorganic particles, colloidally dispersed silica fine particles, and the like may be further included. it can.

  In the present invention, the mixing ratio of the constituent components of the high refractive index layer is preferably the mass ratio of the resin component and the metal compound particles [(A) / (B)], preferably 10/90 to 30/70, more preferably. It is good to be 15/85 to 25/75. When the metal compound particles are within such a preferable range, the obtained film has sufficient transparency and good electrical conductivity, and on the other hand, various physical and chemical strengths of the obtained film do not deteriorate.

In order to provide a desired level of antistatic properties by such a high refractive index layer, it is preferable to control the addition amount so that the surface resistance value of the layer is 1 × 10 ¹¹ Ω / □ or less, It is preferable to control the amount of addition so that it becomes 1 × 10 ¹⁰ Ω / □ or less.

  Such a high refractive index layer is preferably a layer having a total light transmittance of preferably 40% or more, more preferably 50% or more, from the viewpoint of sharpness and transparency.

  In the present invention, the high refractive index layer is preferably prepared by preparing a coating solution dispersed with a solvent, coating the coating solution on the hard coat layer, drying the solvent to evaporate, and then irradiating with ultraviolet rays to cure. Can be formed.

  The constituent components of the low refractive index layer of the present invention are not particularly limited, but those having a low refractive index and excellent scratch resistance are preferred, silica fine particles having cavities therein, and siloxane containing fluorine The coating composition containing the compound is preferably obtained by coating, because the refractive index can be lowered and the surface reflectance can be lowered.

  Furthermore, in the low refractive index layer of the present invention, the siloxane compound as a matrix material and the silica fine particles having cavities inside are firmly bonded in order to improve the surface hardness and have excellent scratch resistance. For this purpose, it is preferable that the siloxane compound is previously reacted with the surface of the silica fine particles and bonded at the stage of the coating composition before coating.

  The coating composition for that purpose can be obtained by hydrolyzing the silane compound in a solvent with an acid catalyst in the presence of silica fine particles to form a silanol compound and then subjecting the silanol compound to a condensation reaction. As the silanol compound, one or more silane compounds selected from silane compounds represented by the following general formulas (5) to (9) are preferable.

  The obtained paint contains a siloxane compound that is a condensate of these silane compounds. Moreover, although these silane compounds are hydrolyzed, you may contain the silanol compound which has not condensed yet.

R ¹ Si (OR ⁶ ) ₃ (5)
Here, R ¹ represents a fluoroalkyl group having 3 to 17 fluorine atoms. The number of fluorine in R ¹ is preferably 6-8. When the number of fluorine atoms per molecule is large, the hardness of the obtained film tends to decrease. R ¹ preferably has 3 to 10 carbon atoms, and particularly preferably 3 carbon atoms, because the resulting coating film can have high scratch resistance.

R ⁶ represents a methyl group, an ethyl group, a propyl group, an isopropyl group, or an acetyl group, and may be the same or different. R ⁶ is more preferably a methyl group or an ethyl group.

  It is preferable to use a trifunctional silane compound represented by the general formula (5) because the refractive index of the resulting film can be lowered.

R ² Si (OR ⁷ ) ₃ (6)
Here, R ² represents a group selected from a vinyl group, an allyl group, an alkenyl group, an acrylic group, a methacryl group, a methacryloxy group, a cyano group, an epoxy group, a glycidoxy group, an amino group, and a substituted product thereof. R ² having 2 to 10 carbon atoms is preferred because it can increase the scratch resistance of the resulting coating.

R ⁷ represents a methyl group, an ethyl group, a propyl group, an isopropyl group, a methoxyethyl group, or an acetyl group, and may be the same or different. R ⁷ is more preferably a methyl group or an ethyl group.

  It is preferable to use a trifunctional silane compound represented by the general formula (6) because the hardness of the resulting film can be improved.

R ³ Si (OR ⁸ ) ₃ (7)
Here, R ³ represents a group selected from hydrogen, an alkyl group, an aryl group, and substituents thereof. The number of carbon atoms of R ³ is preferably 1 to 6 because the scratch resistance of the obtained film can be increased. If R ³ exceeds 6 carbon atoms, the hardness of the resulting coating tends to decrease.

R ⁸ represents a methyl group, an ethyl group, a propyl group, or a butyl group, and may be the same or different. R ⁸ is more preferably a methyl group or an ethyl group.

  Use of the trifunctional silane compound represented by the general formula (7) is preferable because the hardness of the resulting film can be improved.

R ⁴ R ⁵ Si (OR ⁹ ) ₂ (8)
Here, R ⁴ and R ⁵ each represents a group selected from hydrogen, an alkyl group, a fluoroalkyl group, an aryl group, an alkenyl group, a methacryloxy group, an epoxy group, a glycidoxy group, an amino group, and a substituent thereof. Each may be the same or different. As C4 of R < ⁴ >, R < ⁵ >, since 1-6 can improve the abrasion resistance of the obtained film, it is preferable.

R ⁹ represents a methyl group, an ethyl group, a propyl group, an isopropyl group or an acetyl group, and may be the same or different. R ⁹ is more preferably a methyl group or an ethyl group.

  Use of the bifunctional silane compound represented by the general formula (8) is preferable because the flexibility of the resulting film can be improved.

Si (OR ¹⁰ ) ₄ (9)
Here, R ¹⁰ represents a methyl group or an ethyl group, and may be the same or different.

  It is preferable to use a tetrafunctional silane compound represented by the general formula (9) because the hardness of the resulting film can be improved.

  These silane compounds represented by the general formulas (5) to (9) may be used alone or in combination of two or more.

  The content of the siloxane compound constituting the low refractive index layer is preferably 20% by mass or more and 70% by mass or less, particularly preferably 30% by mass or more and 60% by mass or less, based on the total amount of the film when the film is formed. is there. When the siloxane compound is contained within this range, the refractive index of the coating film can be lowered and the hardness of the coating film can be increased.

  Among these, in order to reduce the refractive index, the fluorine-containing silane compound represented by the general formula (5) is used as an essential component, and the silane compound represented by the general formulas (6) to (9) is selected. In addition, it is preferable to use a combination of at least one silane compound. The amount of the silane compound represented by the general formula (5) is preferably 20% by mass or more and 80% by mass or less, and particularly preferably 30% by mass or more and 60% by mass or less with respect to the total amount of the silane compound. When the amount of the silane compound is less than 20% by mass, the reduction in the refractive index may be insufficient. On the other hand, when the amount of the silane compound of the general formula (5) exceeds 80% by mass, the hardness of the film may be lowered.

  Specific examples of the silane compounds represented by the general formulas (5) to (9) are shown below.

  Examples of the trifunctional silane compound represented by the general formula (5) include trifluoromethyltrimethoxysilane, trifluoromethyltriethoxysilane, trifluoromethyltriacetoxysilane, trifluoropropyltrimethoxysilane, and trifluoropropyl. Triethoxysilane, trifluoropropyltriacetoxysilane, trifluoroacetoxyethyltrimethoxysilane, trifluoroacetoxyethyltriethoxysilane, trifluoroacetoxyethyltriacetoxysilane, perfluoropropylethyltrimethoxysilane, perfluoropropylethyltriethoxysilane , Perfluoropropylethyltriacetoxysilane, perfluoropentylethyltrimethoxysilane, perfluoropentylethyltriethoxy Silane, perfluoropentylethyltriacetoxysilane, tridecafluorooctyltrimethoxysilane, tridecafluorooctyltriethoxysilane, tridecafluorooctyltripropoxysilane, tridecafluorooctyltriisopropoxysilane, heptadecafluorodecyltrimethoxysilane , Heptadecafluorodecyltriethoxysilane, and the like. Of these, trifluoromethyltrimethoxysilane, trifluoromethyltriethoxysilane, trifluoropropyltrimethoxysilane, and trifluoropropyltriethoxysilane are preferred from the viewpoint of the hardness of the resulting coating.

  Examples of the trifunctional silane compound represented by the general formula (6) include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, γ-methacryloxypropyltrimethoxysilane, and γ-methacryloxypropyltriethoxy. Silane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, β-cyanoethyltriethoxysilane, glycidoxymethyltrimethoxysilane, Glycidoxymethyltriethoxysilane, α-glycidoxyethyltrimethoxysilane, α-glycidoxyethyltriethoxysilane, β-glycidoxyethyltrimethoxysilane, β-glycidoxyethyltriethoxysilane, α- Glycidoxypro Rutrimethoxysilane, α-glycidoxypropyltriethoxysilane, β-glycidoxypropyltrimethoxysilane, β-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyl Triethoxysilane, γ-glycidoxypropyltripropoxy silane, γ-glycidoxypropyl tributoxysilane, γ-glycidoxypropyltrimethoxyethoxysilane, α-glycidoxybutyltrimethoxysilane, α-glycid Xylbutyltriethoxysilane, β-glycidoxybutyltrimethoxysilane, β-glycidoxybutyltriethoxysilane, γ-glycidoxybutyltrimethoxysilane, γ-glycidoxybutyltriethoxysilane, δ-glycid Xibutyltrimethoxy , Δ-glycidoxybutyltriethoxysilane, (3,4-epoxycyclohexyl) methyltrimethoxysilane, (3,4-epoxycyclohexyl) methyltriethoxysilane, β- (3,4-epoxycyclohexyl) methyltri Methoxysilane, β- (3,4-epoxycyclohexyl) methyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltripropoxysilane, β- (3,4-epoxycyclohexyl) ethyltributoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxyethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriphenoxysilane, β- (3,4-epoxycyclohexyl) propyltrimethoxysilane, β- (3, 4-epoxycyclohexyl) pro Examples include pyrtriethoxysilane, δ- (3,4-epoxycyclohexyl) butyltrimethoxysilane, and δ- (3,4-epoxycyclohexyl) butyltriethoxysilane. Of these, vinyltrialkoxysilane and 3-methacryloxypropyltrialkoxysilane are preferred from the viewpoint of the hardness of the resulting coating.

  Examples of the trifunctional silane compound represented by the general formula (7) include methyltrimethoxysilane, methyltriethoxysilane, methyltrimethoxyethoxysilane, methyltriacetoxysilane, methyltripropoxysilane, methyltributoxysilane, Ethyltrimethoxysilane, ethyltriethoxysilane, hexyltrimethoxysilane, octadecyltrimethoxysilane, octadecyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, 3-aminopropyltriethoxysilane, N- (2-aminoethyl) ) -3-Aminopropyltrimethoxysilane, 3-chloropropyltrimethoxysilane, 3- (N, N-diglycidyl) aminopropyltrimethoxysilane, 3-glycidoxysipropyltrimethoxy Silane, and the like. Of these, methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, and phenyltriethoxysilane are preferable from the viewpoint of the hardness of the obtained film.

  Examples of the bifunctional silane compound represented by the general formula (8) include dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyldiacetoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, methylphenyldimethoxysilane, and methylvinyldimethoxy. Silane, methylvinyldiethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxy Silane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, glycidoxymethyldimethoxysilane, glycidoxymethylmethyldiethoxysilane, α-glycidoxyethylmethyldimethoxysilane, α-glycidoxyethylmethyldiethoxysilane, β-glycidoxyethylmethyldimethoxysilane, β-glycidoxyethylmethyldiethoxysilane, α-glycidoxypropylmethyldimethoxy Silane, α-glycidoxypropylmethyldiethoxysilane, β-glycidoxypropylmethyldimethoxysilane, β-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropyl Methyldiethoxysilane, γ-glycidoxypropylmethyldipropoxysilane, β-glycidoxypropylmethyldibutoxysilane, γ-glycidoxypropylmethyldimethoxyethoxysilane, γ-glycidoxypropylmethyldiphenoxysilane, γ-glycidoxypropylmethyldiacetoxysilane, γ-glycidoxypropylethyldimethoxysilane, γ-glycidoxypropylethyldiethoxysilane, γ-glycidoxypropylvinyldimethoxysilane, γ-glycidoxypropylvinyldi Ethoxysilane, trifluoropropylmethyldimethoxysilane, trifluoropropylmethyldiethoxysilane, trifluoropropylmethyldiacetoxysilane, trifluoropropylethyldimethoxysilane, trifluoropropylethyldiethoxysilane, trifluoropropylethyldiacetoxysilane, tri Fluoropropylvinyldimethoxysilane, trifluoropropylvinyldiethoxysilane, trifluoropropylvinyldiacetoxysilane, heptadecafluorodecylme Examples include tildimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropylmethyldiethoxysilane, cyclohexylmethyldimethoxysilane, 3-methacryloxypropyldimethoxysilane, and octadecylmethyldimethoxysilane. Of these, dimethyl dialkoxysilane is preferably used for the purpose of imparting flexibility to the resulting coating.

  Examples of the tetrafunctional silane compound represented by the general formula (9) include tetramethoxysilane and tetraethoxysilane.

  As the silica fine particles used in the present invention, silica fine particles having cavities inside are preferable in order to reduce the refractive index of the coating. Silica fine particles having no cavity inside generally have a refractive index lowering effect because the refractive index of the particles themselves is 1.45 to 1.50. On the other hand, since the silica fine particles having cavities inside have a refractive index of 1.20 to 1.40, the effect of lowering the refractive index by introduction is large.

  Examples of the silica fine particles having cavities therein include hollow silica fine particles having a hollow portion surrounded by an outer shell, and porous silica fine particles having a large number of hollow portions. The fine particles preferably have a refractive index of 1.20 to 1.35. Further, the number average particle diameter of the silica fine particles having cavities therein is preferably 5 nm to 100 nm. The refractive index of the silica fine particles can be measured by the method disclosed in paragraph [0034] of JP-A-2001-233611. Silica fine particles having cavities therein are produced, for example, by the method described in paragraphs [0033] to [0046] of JP-A-2001-233611 and the method described in paragraph [0043] of Japanese Patent No. 3272111. can do. A commercially available product can also be used.

  Here, the average particle diameter of the silica fine particles can be measured by a number average particle diameter using various particle counters. It is preferable to measure the particle diameter of the silica fine particles before being added to the paint. Moreover, after the coating is formed, a method of measuring the particle diameter of the silica fine particles in the coating using an electron scanning microscope or a transmission electron microscope is preferable.

  The number average particle diameter of the silica fine particles is preferably smaller than the film thickness of the coating film to be formed. When the film thickness is exceeded, silica fine particles are exposed on the surface of the film, and not only the antireflection property is impaired, but also the surface hardness and stain resistance of the film are lowered.

  The silica fine particles used in the present invention are preferably silica fine particles having a silanol group on the surface in order to easily react with the matrix siloxane compound.

  The content of the silica fine particles constituting the low refractive index layer is preferably 30% by mass or more and 80% by mass or less, particularly preferably 40% by mass or more and 70% by mass with respect to the total amount of the film when the film is formed. It is as follows. When silica fine particles are contained in the coating within this range, not only the refractive index can be lowered, but also the hardness of the coating can be increased. When the content of the silica fine particles is less than 30% by mass, the refractive index lowering effect due to the voids between the particles is reduced. On the other hand, when the content of the silica fine particles exceeds 80% by mass, many island phenomena occur in the coating film, the hardness of the coating film decreases, and the refractive index becomes uneven depending on the location, which is not preferable.

  The surface of the low refractive index layer of the present invention has irregularities derived from such fine particles. As for the surface roughness of the low refractive index layer, the center line average roughness Ra is preferably 0.5 to 15.0 nm, and the maximum height Rmax is preferably 5 to 150 nm. When Ra and Rmax are lower than this range, the antireflection effect may be reduced. Conversely, exceeding this range is not preferable because haze and scratch resistance may be deteriorated and fingerprints may be difficult to wipe off.

  The contact angle of the surface of the low refractive index layer with respect to water is preferably 95 degrees or more, more preferably 100 degrees or more, and particularly preferably 105 degrees or more. I can do it.

The optical film in the present invention is usually installed and used on the outermost surface of a display. In that case, since scratches are made when dust or the like adhering to the surface of the film is wiped off with a cloth, the scratch resistance on the surface of the antireflection layer is preferably 3 or more, more preferably 4 or more. It is good. The scratch resistance is such that the antireflection layer side surface of the optical film is subjected to a load of 250 g on # 0000 steel wool and subjected to 10 reciprocating frictions at a stroke width of 10 cm and a speed of 30 mm / sec. The method of scratching is evaluated in the following five stages.
5th grade: No scratches.
Fourth grade: 1 to 5 scratches.
3rd grade: 6 to 10 scratches.
Second grade: 11 or more scratches.
First grade: Countless scratches on the entire surface.

  As a coating method for the hard coat layer, high refractive index layer, and low refractive index layer, microgravure coating, spin coating, dip coating, curtain flow coating, roll coating, spray coating, flow coating, etc. are preferably used. However, microgravure coating is preferably used from the viewpoint of uniformity of coating thickness. After coating, each film is formed by drying and curing by heat or ultraviolet irradiation.

  The optical film of the present invention is obtained by laminating an acrylic resin layer containing an organic dye compound on an easy-adhesion layer having a phase separation structure of a polyester film base material, and has an antireflection function, a near infrared absorption and / or Or by combining the wavelength selective absorption function that can absorb visible light of a specific wavelength sharply, rather than laminating several films with each optical function with adhesive etc., members and pasting This is more preferable because the number of steps can be reduced and the manufacturing cost of the optical filter can be reduced.

  In the present invention, the organic dye compound-containing acrylic resin layer includes an organic dye compound having the ability to selectively absorb near-infrared absorption or visible light having a specific wavelength, using an acrylic resin having excellent transparency as a binder. It is a laminated film made of a resin composition.

  When such an organic dye compound-containing acrylic resin layer contains a near-infrared absorbing dye, the optical film of the present invention has a transmittance of 15% or less at a wavelength of 850 nm and a transmittance of 10% or less at a wavelength of 950 nm to 1150 nm. Is preferably satisfied. Further, the transmittance at a wavelength of 850 nm is more preferably 11% or less, and the transmittance at a wavelength from 950 nm to 1150 nm is more preferably 7% or less.

  Such near-infrared-absorbing dyes absorb in the near-infrared region such as anthraquinone dyes, cyanine dyes, diimonium dyes, phthalocyanine dyes, naphthalocyanine dyes, dithiol nickel complex dyes, azocobalt complex dyes, and squarylium dyes. In particular, a diimonium dye is suitably used as a dye that absorbs a wide range in the near infrared region. Specifically, “IRG-022”, “IRG-023”, “IRG-050”, “IRG-068”, Nippon Carlit “Nippon Kayaku Co., Ltd.” CIR-1081 "," CIR-1085 "," FD-RH "and the like.

Such a diimonium dye has a wide effective absorption wavelength region in the near infrared region having a wavelength of 850 to 1250 nm, and an organic dye in a resin layer per unit area in order to reduce the transmittance at a wavelength of 950 nm to 1150 nm to 10% or less. Is preferably 0.1 to 0.5 g / m ^2, and more preferably 0.2 to 0.4 g / m ² . If the content is below this range, the near-infrared shielding property may be inferior, and if the content exceeds this range, the total light transmittance may be insufficient and the image may become dark.

  As the near-infrared absorbing dye in the present invention, only the diimonium-based dye may be used, but in order to make the transmittance at a wavelength of 850 nm alone 15% or less, the content needs to be increased. In some cases, the total light transmittance may be insufficient. Therefore, in the present invention, it is preferable to use one or more near infrared absorbing dyes having an absorption maximum wavelength in a wavelength range of 800 nm to 900 nm together with the diimonium dye. Specific examples include phthalocyanine dyes, naphthalocyanine dyes, cyanine dyes, and dithiol nickel complex dyes. Among these, phthalocyanine dyes having one or more substituents such as primary and / or secondary amino groups, alkoxy groups, and fluorine groups from the viewpoint of light resistance and wet heat resistance are preferably used. Specific examples include “IR-1”, “IR-10”, “IR-12”, “IR-14”, etc., whose title is EEXCOLOR (registered trademark) manufactured by Nippon Shokubai Co., Ltd. .

  In addition, although cyanine dyes have difficulty in light resistance, as an improved dye, a dye that is previously integrated by coupling a cyanine compound and a quencher is also used as an alternative to the phthalocyanine dye in the present invention. Is preferably used. Here, the quencher agent is an anti-degradation agent for near-infrared absorbing dyes, which improves the light resistance of cyanine dyes by integrating them, and provides a high extinction coefficient that is characteristic of cyanine dyes. The amount used can be reduced. Here, as the quencher agent, bis (1,2-dithiophenolate) copper tetra-n-butylammonium salt is preferable because it does not impair the light resistance of the diimonium dye used together. Specific examples of such an integrated dye of a cyanine dye and a quencher include “SD50-E04N” and “SD50-E05N” manufactured by Sumitomo Seika Co., Ltd. and “TZ-111” manufactured by Asahi Denka Kogyo Co., Ltd. , “TZ-114”, “TZ-118” and the like.

In the organic dye-containing acrylic resin layer, the content in the resin layer per unit area of the near-infrared absorbing dye compound having an absorption maximum wavelength in the wavelength range of 800 nm to 900 nm is the absorption coefficient of the dye used or the content of the diimonium dye. Although it is determined according to the amount, in order to make the transmittance at a wavelength of 850 nm 15% or less, the content is preferably 0.01 to 0.3 g / m ^2, and in particular, a cyanine dye and a quencher. In the case of using an integral dye with the agent, it is preferably 0.01 to 0.1 g / m ² . If the content is below this range, the near-infrared shielding ability may be inferior, and if the content exceeds this range, the total light transmittance may be insufficient and the image may become dark.

  In the case of containing an organic dye that selectively absorbs visible light of a specific wavelength, the optical film of the present invention preferably has a maximum absorption wavelength in the range of 570 to 610 nm, and the maximum absorption wavelength is adapted. The ineffective wavelength in the emission spectrum of the image display device is preferable.

  When the optical film of the present invention is used for an optical filter for PDP, a dye that selectively absorbs orange light around 590 nm accompanying emission of neon gas sealed in the panel is preferably used. In this case, a dye having a maximum absorption wavelength in the wavelength range of 580 to 610 nm is preferable, and the transmittance of the optical film at a wavelength of 590 nm is preferably 60% or less, more preferably 45% or less. The transmittance at a wavelength of 590 nm is preferably low, but if it is too low, the total light transmittance is also low, so it is preferably 20% or more. Moreover, it is preferable to use an organic dye compound having a maximum absorption peak half width of 100 nm or less, preferably 50 nm or less.

  Moreover, when using the optical film of this invention for the optical filter for SED, the pigment | dye which selectively absorbs yellow light of 575 nm vicinity is used preferably. In this case, a dye having a maximum absorption wavelength in the wavelength range of 570 to 580 nm is preferable, and the transmittance at a wavelength of 575 nm is preferably 50% to 90%, more preferably 60% to 80%. The transmittance at a wavelength of 575 nm is preferably low, but if it is too low, the total light transmittance is also low, which is not preferable.

  Examples of organic dyes that selectively absorb visible light having a specific wavelength used in the present invention include porphyrazine dyes (also known as tetraazaporphyrin dyes) or cyanine dyes as disclosed in JP-A-2002-129052. , Light resistance, heat resistance, heat and humidity resistance, solubility in organic solvents, and extinction coefficient.

The content of the organic dye in the organic dye-containing acrylic resin layer per unit area is determined from the required value of transmittance (or absorbance) at a specific wavelength to be shielded and the extinction coefficient of the organic dye to be used. a .001~0.15g / ^{m 2,} more and more preferably, 0.01~0.10g / ^{m 2.}

  Furthermore, in an optical film used for an optical filter for PDP, both an organic dye having a maximum absorption wavelength in the range of 580 to 610 nm and the near infrared absorbing dye are used in combination, and near infrared absorption and wavelength selective absorption of visible light are performed. These functions may be combined.

  The acrylic resin used as the binder according to the present invention is preferably one that is substantially colorless and transparent without visible light absorption, has excellent weather resistance, and does not deteriorate the performance of the organic dye compound.

  Such acrylic resins are methyl (meth) acrylate, ethyl (meth) acrylate, n- or isopropyl (meth) acrylate, n- or sec- or tert-butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) ) Acrylate, cyclohexyl (meth) acrylate, methylcyclohexyl (meth) acrylate, cyclododecyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, hydroxy Several kinds of unsaturated selected from ethyl (meth) acrylate, (meth) acrylic acid, itaconic acid, maleic anhydride, glycidyl (meth) acrylate, fluorine-containing (meth) acrylate, and styrene Those obtained by copolymerizing a monomer is preferred.

  Furthermore, in order to improve the light resistance of the organic dye, an unsaturated monomer having a hindered amine that is a UV-stable group (for example, Adekastab (registered trademark) LA-82, LA-87, etc. manufactured by Asahi Denka Kogyo Co., Ltd.) A copolymer obtained by copolymerizing an unsaturated monomer having an ultraviolet absorbing group such as benzotriazole, benzophenone, or triazine is also preferably used.

  Alternatively, adding a hindered amine additive (eg Sanol Lifetech Co., Ltd. Sanol (registered trademark) LS-765, LS-2626, etc.) or an ultraviolet absorber to the polymerized resin also improves the light resistance of the organic dye. It is preferable from the point which can be performed.

  The acrylic resin used in the organic dye-containing acrylic resin layer has a glass transition point of preferably 80 ° C. or higher, more preferably 100 ° C. or higher from the viewpoint of heat resistance, but is not limited thereto. In order to reduce the influence of moisture on the organic dye, the hygroscopicity of the acrylic resin is preferably 2% or less.

  Furthermore, the acrylic resin constituting the organic dye-containing acrylic resin layer may be cross-linked in order to improve solvent resistance. In that case, cross-linking of aliphatic diisocyanate, alicyclic diisocyanate, aromatic diisocyanate, melamine, etc. An agent is preferably used. Moreover, in order to improve adhesiveness with an easily bonding layer, you may add a silane coupling agent. Examples of such silane coupling agents include alkoxysilane compounds having an unsaturated group or an epoxy group.

  Such an organic dye-containing acrylic resin is preferably soluble in an organic solvent in which the organic dye compound is soluble, that is, methyl ethyl ketone, methyl butyl ketone, cyclohexanone, acetone, acetonitrile, ethyl acetate, butyl acetate, toluene, xylene An organic dye compound that is soluble in a simple solvent such as a solvent or a mixed solvent of two or more is preferably used.

  The viscosity of the acrylic resin constituting the organic dye-containing acrylic resin layer is set to 50 to 5000 mPa.s in consideration of workability when an organic dye compound is prepared and made into a paint. It is preferable that it is s, and it is preferable that the solid content density | concentration of an acrylic resin is 10 to 50 mass%.

  Commercially available products of such acrylic resins include Mitsubishi Rayon Co., Ltd., Dainar (registered trademark) BR-80, Nippon Shokubai Co., Ltd., Hals Hybrid (registered trademark) IR-G205, Soken Chemical Co., Ltd. foret (registered) (Trademark) GS-1000 etc. are mentioned as a suitable example.

  The above-mentioned organic coloring compound can be used as either a dye or a pigment, but it is preferable to use a dye in consideration of transparency and visible light transmittance. When using dye, what melt | dissolves in the said organic solvent in which an acrylic resin is soluble is preferable. Such an organic dye compound is used after being dissolved in such an organic solvent and then mixed with an acrylic resin solution to form a coating liquid. Furthermore, it is also preferable to mix | blend an ultraviolet absorber, a ultraviolet stabilizer, antioxidant, a leveling agent, an antifoamer, etc. with this coating liquid.

  Such a coating liquid is applied onto an easy-adhesion layer having a phase separation structure of a polyester film by a coating method such as three reverse coaters, normal rotation or reverse gravure coaters, comma coaters, and die coaters, and is heated and dried. A film is formed.

  The thickness of the organic dye-containing acrylic resin layer of the present invention is not particularly limited, but is preferably 1 to 30 μm, and more preferably 3 to 15 μm from the viewpoint of the coating property of the paint on a film.

  The optical film of the present invention is bonded to a film having other functions such as an electromagnetic wave shielding film or an antistatic film, or a semi-tempered glass substrate, and used as an optical filter. Therefore, an adhesive layer is further laminated on the organic dye-containing acrylic resin layer.

  The pressure-sensitive adhesive layer used in the present invention is not particularly limited as long as two objects are bonded by their pressure-sensitive adhesive action. As the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer, rubber-based, vinyl polymerization-based, condensation polymerization-based, thermosetting resin-based, silicone-based, and the like can be used. Among these, examples of the rubber-based adhesive include butadiene-styrene copolymer system (SBR), butadiene-acrylonitrile copolymer system (NBR), chloroprene polymer system, and isobutylene-isoprene copolymer system (butyl rubber). it can.

  Examples of the vinyl polymerization pressure-sensitive adhesive include acrylic, styrene, vinyl acetate-ethylene copolymer system, vinyl chloride-vinyl acetate copolymer system, and the like. Examples of the condensation polymerization pressure-sensitive adhesive include polyester. Furthermore, examples of the thermosetting resin-based pressure-sensitive adhesive include epoxy resin-based, urethane resin-based, and formalin resin-based adhesives. Among these, acrylic adhesives are preferably used in consideration of transparency, weather resistance, heat resistance, moist heat resistance, substrate adhesion, and the like. Specific examples of the acrylic pressure-sensitive adhesive include SK Dyne (registered trademark) 1435, SK Dyne 1811L, SK Dyne 1888, SK Dyne 2094, SK Dyne 2096, SK Dyne 2137, SK Dyne 3096, SK manufactured by Soken Chemical Co., Ltd. A suitable example is Dyne 1852.

  Since such an acrylic pressure-sensitive adhesive alone has low cohesive force, it is preferably crosslinked with a crosslinking agent. As such a crosslinking agent, an isocyanate compound, an epoxy compound, an aziridine compound, a metal chelate compound, or the like is suitably used.

  In addition, an antioxidant, an ultraviolet absorber, a silane coupling agent, a metal deactivator, and the like may be appropriately added and blended with the acrylic adhesive depending on the material of the adherend (glass or functional film). Is preferred.

  Further, such an acrylic adhesive layer may contain the above-described organic dye compound, especially an organic dye that selectively absorbs a specific wavelength of visible light.

  In addition, since the optical film is colored by the above-mentioned near-infrared absorbing dye and visible light wavelength-selective absorbing dye, a colorant is contained in the acrylic resin or the acrylic adhesive layer in order to make the optical filter the desired color. The toning is preferably performed. In this case, the colorant to be used is blended with a colorant that is complementary to the color of the optical film, and the optical filter as a whole is adjusted to an achromatic color (neutral gray color) or a color close to it (blueish gray color). preferable.

  As the colorant, a pigment or a dye is used. Examples of pigments include isoindolinone, anthraquinone, dioxazine, azo, naphthol, quinophthalone, azomethine, benzimidazolone, perinone, pyranthrone, quinacridone, perylene, phthalocyanine, selenium, etc. Among these, dioxazine-based, azo-based, naphthol-based, quinacridone-based red pigments, and phthalocyanine-based blue pigments are preferable, and quinacridone-based, dioxazine-based, copper phthalocyanine are the most suitable pigments. Based pigments. These pigments are preferably used with an average particle diameter of 0.01 to 5 μm, more preferably 0.01 to 1 μm. When the average particle diameter is higher than this range, the haze of the colored layer is increased, which is not preferable. On the other hand, those smaller than this range are not preferable because pigment dispersion becomes difficult. Various dyes can be appropriately used as the dye.

  The pressure-sensitive adhesive layer preferably has a film peel strength at 90 degrees in the range of 1 to 25 N / 25 mm when an optical film is bonded to a blue plate glass plate previously degreased with alcohol or the like, and more preferably 5 to 15 N / 25 mm. The range of is preferable. If the peel strength is lower than the above value, the adhesive strength is weak and easy to peel off. Conversely, if the peel strength is higher than the above value, the reworkability is deteriorated.

  The thickness of the adhesive layer is preferably 10 to 50 μm, and more preferably 15 to 30 μm.

  Further, such an adhesive layer is bonded to the release film in consideration of workability until it is actually bonded to semi-tempered glass or another functional film. As such a release film, a film in which a film base material such as polyester is coated with a release agent such as silicone is preferably used.

  The peel strength at 90 degrees with the pressure-sensitive adhesive layer of the release film is preferably in the range of 10 to 100 mN / 25 mm, and more preferably in the range of 30 to 70 mN / 25 mm, because a good peel feeling can be obtained. . Specific examples of such a release film include Toray Film Processing Co., Ltd. Therapy (registered trademark).

  Such an adhesive layer is applied to the release surface of the release film by a coating method such as a three reverse coater, a normal rotation or reverse gravure coater, a comma coater, or a die coater, and is dried in an oven to form a film. Thereafter, a method of laminating by laminating with a resin layer containing an organic dye is preferable, but the method is not limited to this method.

  The optical film of the present invention is bonded to a functional film such as an electromagnetic wave shielding film, an antistatic film, an antireflection film, an antiglare film, a gas barrier film, or a semi-reinforced glass substrate, and is suitably used as an optical filter.

  As an example of a preferred embodiment of the optical filter of the present invention, the optical film of the present invention is bonded to a glass substrate via an adhesive, and an electromagnetic wave shielding film is bonded to the opposite glass surface to provide an optical filter for pre-installing a plasma display panel. Used as Furthermore, an antireflection film or an antiglare film may be bonded onto the electromagnetic wave shielding film.

  Also, the optical film of the present invention can be bonded to an electromagnetic wave shielding film to form an optical filter that does not use a glass substrate, and can also be a film type filter that is directly bonded to the front surface of a plasma display panel via a pressure-sensitive adhesive. Preferably used.

  Furthermore, the optical film of the present invention is preferably used as an optical filter for surface electric field display by laminating with an antistatic film.

By providing the optical film of the present invention on the surface of any optical filter,
By suppressing interference fringes and excellent adhesion to the organic dye-containing acrylic resin layer, and further suppressing reflection from the back side of the optical film, it is possible to obtain an optical filter with better antireflection performance. .

  Next, although this invention is demonstrated based on an Example, this invention is not necessarily limited to these.

1. Characteristics Evaluation Method (1) Phase Separation Structure of Easy Adhesion Layer and Thickness Measurement of High Refractive Index Layer and Low Refractive Index Layer Cross section of easy adhesion layer and antireflection layer of the produced optical film was measured with a transmission electron microscope (Hitachi H -7100FA type) was observed at an acceleration voltage of 100 kV. Sample preparation used the ultrathin section method. Observation was performed at a magnification of 100,000 times or 200,000 times, and the thickness of each layer was measured. Further, from the result, the ratio d _H / d _L of the thickness d _H of the high refractive index layer and the thickness d _L of the low refractive index layer was determined.

(2) 5 degree regular reflectance measurement No. 320-400 water-resistant sandpaper so that the 60 ° C glossiness (JIS Z8741) is 10 or less on the surface opposite to the measurement surface (surface on which the antireflection layer is provided) After the surface was uniformly roughened, a black paint was applied and colored so that the visible light transmittance was 5% or less. Using a spectrophotometer (UV-3150) manufactured by Shimadzu Corporation, the specular reflection spectrum in the wavelength region of 380 nm to 780 nm was measured at an incident angle of 5 degrees, and the minimum reflectance, its wavelength, and the maximum reflectance were measured. The difference in minimum reflectance was determined. When the measured reflection spectrum has undulations, the respective reflectances were obtained from curves connecting intermediate points between undulation peaks (maximum points) and valleys (minimum points). Further, the luminous regular reflectance was obtained from the standard spectral luminous efficiency.

(3) Transmittance measurement The transmission spectrum of the optical film was measured in the wavelength range of 380 to 1200 nm with a spectrophotometer (UV-3150) manufactured by Shimadzu Corporation. As the near infrared shielding property, a transmittance of 850 nm and a maximum transmittance in a range of 950 to 1150 nm were determined. Furthermore, when the transmission spectrum has a maximum absorption wavelength in the visible light region, the maximum absorption wavelength and its transmittance were determined.

(4) Adhesiveness between the organic dye-containing acrylic resin layer and the easy-adhesion layer Adhesion between the organic dye-containing acrylic resin layer and the easy-adhesion layer by the adhesion test by the cross-cut method of the coating film described in JIS K5600-5-6 Sex was tested. In the test, an organic dye-containing acrylic resin layer was cut into a 10 × 10 grid pattern with a 1 mm square using a multi-blade cutting tool (ERICHSEN GMBH & CO KG model 295 / V), and a cellophane adhesive tape (JIS Z1522) was cut there. ) Was attached and peeled off instantaneously while maintaining an angle of 60 degrees. The evaluation was made in 6 grades from 0 to 5 according to the degree of peeling of the acrylic resin layer. A state in which the edge of the cut is completely smooth and there is no peeling in any lattice eye is classified as Category 0, and a case where peeling is observed is classified in any one of Classifications 1 to 5 depending on the state.

(5) Observation of interference fringes Under a three-wavelength fluorescent lamp, the organic pigment-containing acrylic resin layer surface of the optical film was visually observed from an angle of 90 degrees, and the intensity of color unevenness due to the interference fringes was evaluated in three stages (○ : Light color unevenness, ×: dark color unevenness, Δ: moderate color unevenness thereof).

2. Adjustment of water-based paint for easy adhesion (1) Adjustment of water-based paint for easy adhesion on the hard coat layer side As polyester resin, 30/30 of terephthalic acid / isophthalic acid / 5-sodium sulfoisophthalic acid / ethylene glycol / 1,4-butanediol Water-based polyester resin coating solution polycondensed at 15/5/30/20 (mol%) (resin solid content 25%, acid value 15 mg / g, glass transition temperature 45 ° C., refractive index 1.58), melamine “Nicarac MW12LF” manufactured by Sanwa Chemical Co., Ltd. as the cross-linking agent and “Epocross WS500” manufactured by Nippon Shokubai Co., Ltd. as the oxazoline-based cross-linking agent are mixed so that the polyester resin is 75% by mass, melamine is 20% by mass, and oxazoline is 5% by mass. Further, 0.2% by mass of colloidal silica having an average particle size of 80 nm is added as an easy-sliding material to obtain a concentration of 5.7. The water-based paint was prepared.

(2) Adjustment of organic pigment-containing layer side easy-to-adhere water-based paint In the water-based paint, methyl methacrylate / ethyl acrylate / acrylic acid / N-methylol acrylamide is 75/20/3/2 (weight ratio) as an acrylic resin. Using a copolymerized water-based acrylic resin coating (resin solid content: about 35%, acid value: 2.8 mg / g, glass transition temperature: 42 ° C., refractive index: 1.51), the polyester resin is 56% by mass in terms of solid content. A mixture of acrylic resin 24 mass% and melamine 20 mass% was added, and 0.2 wt% of colloidal silica having an average particle size of 80 nm was added as an easy-to-lubricant to prepare an aqueous paint having a concentration of 5.7%.

3. Preparation of Low Refractive Index Paint 95.2 parts by mass of methyltrimethoxysilane and 65.4 parts by mass of trifluoropropyltrimethoxysilane were dissolved in 300 parts by mass of propylene glycol monomethyl ether and 100 parts by mass of isopropanol. In this solution, a silica fine particle dispersion having a cavity inside the outer shell having a number average particle diameter of 50 nm (isopropanol dispersion type, solid content concentration 20.5%, manufactured by Catalyst Kasei Kogyo) 297.9 parts by mass, water 54 parts by mass And 1.8 parts by mass of formic acid was added dropwise with stirring so that the reaction temperature did not exceed 30 ° C. After the dropwise addition, the obtained solution was heated at a bath temperature of 40 ° C. for 2 hours, and then the solution was heated at a bath temperature of 85 ° C. for 2 hours, the internal temperature was raised to 80 ° C. and heated for 1.5 hours, The polymer solution A was obtained.

  A solution obtained by dissolving 4.8 parts by mass of aluminum tris (acetylacetate) (“Aluminum Chelate A (W)” manufactured by Kawaken Fine Chemicals) in 125 parts by mass of methanol is added to the obtained polymer solution A. Further, 1500 parts by mass of isopropanol and 250 parts by mass of propylene glycol monomethyl ether were added and stirred at room temperature for 2 hours to prepare a low refractive index paint. A film of the prepared paint was formed on a silicon wafer, and the refractive index at 633 nm was determined by a phase difference measuring device (“NPDM-1000” manufactured by Nikon). The refractive index was 1.36.

4). Preparation of paint containing organic dye compound (1) Paint containing organic dye compound-1
As an organic dye having a maximum absorption at 575 nm, 1.74 parts by mass of “TAP-5” manufactured by Yamada Chemical Industries, and 0.15 parts by mass of “KAYASET Yellow AG” manufactured by Nippon Kayaku as a coloring dye "KAYASET Green AB" was dissolved by stirring and mixing 0.17 parts by mass with 1000 parts by mass of methyl ethyl ketone. This solution was used as a transparent polymer resin binder solution and stirred and mixed with 2000 parts by mass of Nippon Shokubai "Hals Hybrid IR-G205" (solid content concentration 29% solution) to prepare an organic dye-containing paint-1.

(2) Organic dye compound-containing paint-2
As a near-infrared absorbing dye, 14.5 parts by mass of “KAYASORB IRG-050” manufactured by Nippon Kayaku, 8 parts by mass of “EEX Color IR-10A” manufactured by Nippon Shokubai, and an organic dye having a maximum absorption at 593 nm, 2.9 parts by mass of “TAP-2” manufactured by Yamada Chemical Co., Ltd. was dissolved in 1000 parts by mass of methyl ethyl ketone with stirring. This solution was used as a transparent polymer resin binder solution, and stirred and mixed with 2000 parts by mass of “Hals Hybrid IR-G205” (solid content concentration 29% solution) manufactured by Nippon Shokubai to prepare an organic dye compound-containing paint-2.

[Example 1]
Polyethylene terephthalate was melt-extruded at 280 ° C., cast on an electrostatically applied 20 ° C. cast drum to form an unstretched sheet, preheated at 80 ° C., and then stretched in the longitudinal direction by roll stretching at this temperature. Stretched 0 times. Thereafter, a hard coating layer side easy-adhesion water-based paint was first applied to one surface. Further, an organic pigment compound-containing acrylic resin layer-side easy-to-adhere water-based paint was applied to the opposite surface. Thereafter, the film was stretched 3.5 times in the width direction at 110 ° C. and heat-treated at 220 ° C.

  The laminated film thus obtained is the above-mentioned 1. The thickness of the easy adhesion layer observed by the method described in (1) is such that an easy adhesion layer made of a polyester resin having a thickness of 60 nm is laminated on the hard coat layer side, and a base material on the organic dye compound-containing acrylic resin layer side A laminated film having a total thickness of 60 nm is formed by phase separation with a polyester resin as a main component from the side having a thickness of 34 nm, a mixed region of the polyester resin and the acrylic resin being 12 nm, and a phase having the acrylic resin as a main component being 14 nm in thickness. The film was a laminated film having a thickness of 100 μm based on a polyethylene terephthalate film.

Next, a coating material obtained by diluting a commercially available hard coat agent (“Desolite (registered trademark) Z7528” manufactured by JSR) with isopropyl alcohol to a solid content concentration of 30% is applied to the easily adhesive surface with a microgravure coater, and at 80 ° C. After drying for 1 minute, it was cured by irradiating with ultraviolet rays of 1.0 J / cm ² to provide a hard coat layer having a thickness of 5 μm, a refractive index of 1.52, and a pencil hardness of 2H.

Next, a commercially available high refractive index / antistatic coating (“OPSTAR (registered trademark) TU4005” manufactured by JSR) is diluted with isopropyl alcohol to a solid content concentration of 8% on the hard coat layer forming surface, and then applied with a micro gravure coater. Then, after drying at 120 ° C. for 1 minute, ultraviolet rays 1.0 J / cm ² were irradiated and cured to form a high refractive index layer having a refractive index of 1.65 and a thickness of 122 nm on the hard coat layer.

Next, the above-described low refractive index coating is applied to the high refractive index layer forming surface with a micro gravure coater, dried and cured at 130 ° C. for 1 minute, and a low refractive index layer having a refractive index of 1.36 and a thickness of 90 nm. Formed. The thickness ratio d _H / d _L of the antireflection layer is 1.36. The scratch resistance of the antireflection layer was grade 4.

  Next, after attaching “Sanitekt” (R) (thickness 50 μm) made by Sanei Kaken as a protective film to the antireflection surface, the organic pigment compound-containing paint-1 was applied to the phase-separation-adhesive surface with a die coater. And dried at 120 ° C. to form an organic dye compound-containing acrylic resin layer having a thickness of 10 μm and a transmittance of 575 nm of 65%.

  The properties of the produced optical film are shown in Table 1. Both the luminous regular reflectance and the minimum reflectance were low, and a flat reflection characteristic with a reflectance difference of 1.60% was obtained. Moreover, the interference fringes of the organic dye compound-containing acrylic resin layer were visually ◯ level, and the adhesiveness was also good in category 0.

[Examples 2 to 8]
The same method as in Example 1 except that the solid content mass ratio of the polyester resin, the acrylic resin, and the melamine-based crosslinking agent in the organic pigment compound-containing acrylic resin layer side easy-to-adhere water-based coating is changed to the ratio shown in Table 1. A film was prepared.

  The properties of the produced optical film are shown in Table 1. In Example 3 and Example 4, when the mass ratio of the polyester resin is decreased, and instead the amount of the acrylic resin is increased, the minimum reflectance is slightly increased, and the color unevenness of the interference fringes tends to be slightly noticeable. It is done. On the other hand, when the mass ratio of the polyester resin exceeds 60% by mass, the antireflection performance and the color unevenness of the interference fringes are improved, but the adhesiveness tends to be lowered.

[Example 9]
Except for changing the organic dye compound-containing paint-1 to the organic dye compound-containing paint-2, in the same manner as in Example 1, the thickness is 10 μm, the transmittance at 590 nm is 30%, and the transmittance at 850 nm is 8.5%. An optical film having a maximum transmittance of 4.5% in the range of 950 to 1150 nm was produced. The characteristics of the produced optical film are as shown in Table 1.

[Examples 10 to 18]
An optical film was produced in the same manner as in Example 9 except that the thickness of the high refractive index layer and the thickness of the low refractive index layer were changed to those shown in Table 2.

The characteristics of the produced optical film are shown in Table 2. As the ratio d _H / d _L between the thickness of the high refractive index layer and the thickness of the low refractive index layer is decreased, and the thickness of the high refractive index layer and the thickness of the low refractive index layer is decreased, the minimum reflectance becomes lower. However, the difference in reflectance tends to increase. When d _H / d _L is less than 1.7, the minimum reflectance is good at 0.6% or less, and a flat reflection characteristic is obtained with a reflectance difference of 2.5% or less.

  On the other hand, the optical film produced so that the thickness of the high refractive index layer is 91 nm and the thickness of the low refractive index layer is 110 nm is as low as 0.03%, but the reflectance difference is as high as 3.87%. In other words, the film had a so-called V-shaped reflection spectrum, and was a film having a blue-colored glare.

  The optical film produced so that the thickness of the high refractive index layer was 160 nm and the thickness of the low refractive index layer was 80 nm had a very flat reflection spectrum with a reflectance difference of 0.65%. Both the reflectance and the luminous regular reflectance were high, and the antireflection performance was insufficient.

[Comparative Example 1]
Instead of using an easy-adhesion layer having a phase separation structure, the same procedure as in Example 1 was conducted except that an easy-adhesion layer made of a polyester resin was formed by applying a hard coating layer-side easy-adhesion water-based paint to both sides of the polyester film. Thus, an optical film was produced. The properties of the produced optical film are shown in Table 1. Both the minimum reflectance and the luminous regular reflectance were low, and the interference fringe color unevenness was very thin and good, but the adhesion was poor.

[Comparative Example 2]
Instead of using an easy-adhesion layer having a phase separation structure, an acrylic resin coating solution and a melamine cross-linking agent are used instead of a water-based polyester resin coating solution, so that the acrylic resin is 75% by mass and melamine is 25% by mass. An optical film was produced in the same manner as in Example 1 except that an easy-adhesion layer made of an acrylic resin was formed by applying a mixed water-based paint. The properties of the produced optical film are shown in Table 1. Although the adhesiveness was good, the minimum reflectance and the luminous regular reflectance were high, and the antireflection performance was insufficient.

  The optical film of the present invention can lower the reflectance by suppressing reflection from the back surface, and can provide a flat and neutral neutral antireflection performance, and further adheres to an organic dye compound-containing acrylic resin layer. The film is suitably used as a functional composite film having an antireflection function, a near-infrared shielding function, and / or a selective absorption function of an ineffective wavelength in the visible light region. The optical film of the present invention and an electromagnetic wave shielding film, an antistatic film, an antiglare film, a gas barrier film, and other functional films are bonded to each other, so that a plasma display panel (PDP), a surface electrolytic display (SED), etc. It is suitably used as an optical filter of the image display apparatus.

It is the figure which represented typically the cross section of the optical film of the preferable aspect of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Protective film 2 Low-refractive-index layer 3 High-refractive-index layer 4 Hard coat layer 5 Easy-adhesion layer 6 Base film 7 Easy-adhesion layer 8 which has phase-separation structure Organic dye compound containing acrylic resin layer 9 Adhesive layer 10 Release film 11 Antireflection layer

Claims (8)

  A hard coat layer and an antireflection layer are laminated in this order from the polyester film side on one side of the polyester film, and an acrylic resin layer containing at least one organic dye compound is provided on the other side of the polyester film. In the laminated optical film, an easy adhesion layer having a phase separation structure in the thickness direction is provided between the polyester film and the organic dye compound-containing acrylic resin layer, and the easy adhesion layer is a polyester resin on the polyester film side. The organic dye compound-containing acrylic resin layer side is composed of a phase mainly composed of an acrylic resin, and the phase separation interface between both phases of the easy-adhesion layer is a mixed region of each phase. An optical film characterized by the presence of   The optical film according to claim 1, wherein a content ratio of the polyester resin component in the easy-adhesion layer is 20% by mass or more and less than 60% by mass. The antireflection layer is composed of two layers of a high refractive index layer and a low refractive index layer, the refractive index of the low refractive index layer is 1.42 or less, and the refractive index difference between the low refractive index layer and the high refractive index layer. Is 0.15 or more, the thickness d _H of the high refractive index layer of the antireflection layer is in the range of 105 to 160 nm, and the thickness d _L of the low refractive index layer is in the range of 75 to 110 nm. and optical film according to claim 1 or 2 ratio _d H / _{d L} thickness _{d L} of the thickness _{d H} and the low refractive index layer of the high refractive index layer is in the range of 1.0 to 1.9.   The organic dye compound is a near-infrared absorbing dye, has a transmittance of 15% or less at a wavelength of 850 nm, and a transmittance of 10% or less from a wavelength of 950 nm to 1150 nm. The optical film as described.   The optical film according to any one of claims 1 to 4, wherein the organic dye compound is a wavelength selective absorption dye for visible light and has a maximum absorption wavelength in a wavelength range of 580 to 610 nm.   The optical film according to any one of claims 1 to 4, wherein the organic dye compound is a wavelength selective absorption dye for visible light and has a maximum absorption wavelength in a wavelength range of 570 to 580 nm.   The optical filter for plasma displays comprised with the optical film of Claim 5.   The optical filter for surface electric field displays comprised with the optical film of Claim 6.

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