JP2014065887A - Easily adhesive polyester film for optical use - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an easily adhesive polyester film for optical use, which suppresses iridescent hue under fluorescent light, shows excellent adhesiveness to a hard coat layer and excellent adhesiveness (moisture-heat resistance) under high temperature and high humidity conditions, and has resistance to scraping in a coating layer.SOLUTION: The easily adhesive polyester film for optical use comprises a polyester film having a retardation of 3000 to 30000 nm and a coating layer that comprises a polyester resin, particles A and particles B, on at least one surface of the polyester film. The polyester resin comprises a naphthalene dicarboxylic acid as an acid component and a dicarboxylic acid component expressed by formula (1):HOOC-(CH)n-COOH (where n is an integer satisfying 4≤n≤10) and/or a diol component expressed by formula (2):HO-(CH)n-OH (where n is an integer satisfying 4≤n≤10). The particles A are metal oxide particles having a refractive index of 1.7 or more and 3.0 or less; and the particles B are particles having an average particle diameter of 200 nm or more and 700 nm or less.

Description

  The present invention relates to an easily adhesive polyester film for optics. For example, it is attached to the front of a display screen such as a touch panel, a liquid crystal display (LCD), a television or computer cathode ray tube (CRT), a plasma display (PDP), an organic electroluminescence (organic EL), etc. Gives anti-reflective properties to suppress glare, iris-like colors, etc., excellent adhesion to hard coat layer and adhesion after high-temperature and high-humidity treatment, and color caused by optical anisotropy (retardation) of polyester film The present invention relates to an easily-adhesive polyester film for optics that is free from spots and has good visibility.

  A hard coat film in which a transparent hard coat layer is laminated is used on the front surface of displays such as touch panels, computers, televisions, and liquid crystal display devices, and decorative materials. In addition, a transparent biaxially oriented polyester film is generally used as the transparent plastic film of the substrate, and in order to improve the adhesion between the polyester film of the substrate and the hard coat layer, these intermediate layers can be easily used. In many cases, a coating layer having adhesiveness is provided.

  The hard coat film is required to have temperature, humidity, light durability, transparency, chemical resistance, scratch resistance, antifouling property, and the like. Further, since the hard coat film is often used on the surface of a display or a decorative material, visibility and design are required. Therefore, in order to suppress glare and iris-like color caused by reflected light when viewed from an arbitrary angle, the antireflection of a multilayer structure in which a high refractive index layer and a low refractive index layer are laminated on top of the hard coat layer. It is common practice to provide a layer.

  However, in recent years, applications such as displays and decorative materials have been required to have a larger screen (larger area) and higher quality, and accordingly, the required level for suppressing iris-like colors (interference spots) especially under fluorescent lamps. Is getting higher. In addition, fluorescent lamps are mainly in the three-wavelength form for daylight color reproducibility, and interference spots are more likely to appear. Further, there is an increasing demand for cost reduction by simplifying the antireflection layer. Therefore, what suppresses interference spots as much as possible is demanded only by a hard coat film without an antireflection layer.

  The iris-like colors (interference spots) of the hard coat film are the refractive index of the base polyester film (for example, 1.62 to 1.65) and the refractive index of the hard coat layer made of acrylic resin (for example, 1.49). It is said that it occurs because of the large difference. In order to reduce the difference in the refractive index between the layers and prevent the occurrence of interference spots, a coating layer is provided on the polyester film of the base material, the refractive index difference between the polyester film and the coating layer, the refraction of the coating layer and the hard coat layer A method is disclosed in which the refractive index of the coating layer is controlled by the contents of the resin constituting the coating layer and the high refractive additive so as to reduce the difference in rate. Examples of such methods include (1) a water-soluble polyester resin and a water-soluble metal chelate compound or metal acylate compound (Patent Document 1), and (2) a polymer binder and a high refractive index metal oxide. A thing (patent document 2) etc. is proposed.

When suppressing the occurrence of interference spots by the methods (1) and (2), it is important to control the thickness of the coating layer. By providing the coating layer, reflected light generated at the hard coat layer-coating layer interface and reflected light generated at the coating layer-polyester film interface are generated. In order for these two wavelengths to cancel each other and to have opposite phases, This is because the coating layer thickness needs to be controlled within a specific range in optical design. Therefore, when the thickness of the coating layer exceeds a predetermined range, interference spots due to the reflected light occur. Therefore, in the methods (1) and (2), it is necessary to control the coating layer thickness very strictly in production management.

  Furthermore, since the biaxially oriented polyester film proposed above has birefringence, when polarized light such as a liquid crystal display device passes through the hard coat film, it is observed through a polarizing plate such as sunglasses. There is a problem that the image quality deteriorates due to optical distortion. That is, since the polyester film having birefringence has a predetermined optical anisotropy (retardation), when the hard coat film is used on the surface of a liquid crystal display device or the like, when observed through a polarizing plate such as sunglasses, a rainbow -Like color spots occur, and the image quality deteriorates. Patent Documents 3 to 5 disclose a polyester film in which retardation is reduced by using a copolyester as the polyester, but even in that case, the rainbow-like color spots could not be completely eliminated. .

  In addition, there is a method of using a triacetyl cellulose (TAC) film in order to eliminate iridescent color spots caused by optical anisotropy (retardation) of the polyester film, but sufficient mechanical strength can be obtained by reducing the thickness. The problem that it cannot be performed and moisture permeability deteriorates occurs. Further, the TAC film is very expensive and cannot satisfy the cost reduction requirement.

Japanese Patent No. 3632044 JP 2004-54161 A JP 2002-116320 A JP 2004-219620 A JP 2004-205773 A

  With the development of mobile technology, the use of mobile devices such as mobile phones, car navigation systems and e-books in the outdoor field is expanding. In addition, most of the portable devices are liquid crystal panel displays from the viewpoint of thinning. In such a field, for example, in a touch panel mobile phone, as a hard film as a display surface protection, in addition to interference fringes due to reflected light on both interfaces in contact with the coating layer, when observing the display part through sunglasses, etc. Iridescent color spots caused by the optical anisotropy (retardation) of the polyester film can be seen, resulting in poor image quality, and as a hard coat film as an icon sheet, visibility due to interference fringes in applications where the back surface is designed The shortcomings are becoming more apparent.

  However, from the point of improving production efficiency in recent years, various solvents excellent in quick-drying and leveling have come to be used as the solvent of the coating liquid for forming a hard coat layer. Among such solvents, What melt | dissolves the coating layer provided in the polyester film has come to be used. For this reason, even when a coating layer having a specific thickness is provided by the above method, the thickness of the coating layer varies depending on the solvent of the coating liquid for forming the hard coat layer, and interference spots cannot be suppressed.

  In the method (2), since the main component of the polyester resin used for controlling the refractive index is a naphthalene dicarboxylic acid component or a short-chain diol component, the hardness of the resin composition is relatively high, It is a hard coating layer. Therefore, there was a situation in which particles in the coating layer dropped off (powders) during film cutting and adhered as foreign matter.

  Furthermore, in order to improve productivity in recent years, as the speed of post-processing such as hard coat layer lamination and slit processing increases, strong friction is applied to the coating layer, and the thickness of the coating layer due to scraping that has not been a problem in the past Variation and quality variation are becoming issues. In particular, since the resin used for increasing the refractive index has a relatively high hardness and is brittle, the coating layer in which the interference spots are suppressed tends to be more severely scraped.

Therefore, there is an urgent need for an optically easy-adhesive polyester film that has an effect of suppressing interference spots that can be applied in a wide range even with various solvents, and that has less scratching of the coating layer even during high-speed processing, and has a stable effect of reducing interference spots. is there.
That is, the present invention suppresses the iris-like color under a fluorescent lamp, is excellent in adhesion to the hard coat layer, is excellent in adhesion at high temperature and high humidity, and is resistant to the coating layer even during high-speed post-processing. It is an object of the present invention to provide an optically easily adhesive polyester film having shaving properties and an optically laminated polyester film obtained by laminating a hard coat layer on the film.

Furthermore, it is possible to cope with the thinning of the liquid crystal display device (that is, it has sufficient mechanical strength), and it can suppress the occurrence of color spots even when the screen is observed through a polarizing plate such as sunglasses. It is an object to provide a polyester film.

As a result of intensive studies on the coating layer composition, the present inventor has made an average particle size of 200 nm to 700 nm on the coating layer having a predetermined refractive index on at least one side of the polyester film having a retardation of 3000 to 30000 nm. As a result of the addition of large particles, rainbow-like color spots caused by optical anisotropy (retardation) are reduced even when the screen is observed through a polarizing plate such as sunglasses, and it can be applied stably to variations in thickness. A surprising effect of suppressing interference spots caused by reflected light at both interfaces contacting the layer is found, and a polyester resin containing a long-chain dicarboxylic acid component and / or a long-chain diol component having a specific carbon number is used. It is found that the abrasion of the coating layer can be remarkably suppressed, and the optically laminated polyester of the present invention I came to get the Irumu.

That is, a typical present invention is as follows.
Item 1.
An easily adhesive polyester film for optics having a coating layer containing a polyester resin, particles A and particles B on at least one side of a polyester film having a retardation of 3000 to 30000 nm,
The polyester resin includes naphthalenedicarboxylic acid as an acid component, a dicarboxylic acid component represented by the following formula (1) and / or a diol component represented by the following formula (2),
The particle A is a metal oxide particle having a refractive index of 1.7 or more and 3.0 or less,
An easily adhesive polyester film for optics, wherein the particle B is a particle having an average particle size of 200 nm to 700 nm.
(1) HOOC- (CH ₂ ) n —COOH (where n is an integer of 4 ≦ n ≦ 10)
(2) HO— (CH ₂ ) n —OH (where n is an integer of 4 ≦ n ≦ 10)
Item 2.
Item 2. The easily adhesive polyester film for optics according to Item 1, wherein the ratio of the retardation of the polyester film to the retardation in the thickness direction (Re / Rth) is 0.2 or more.
Item 3.
Item 3. The optically easy-adhesive polyester film according to Item 1 or 2, wherein the coating layer contains a crosslinking agent.
Item 4.
The crosslinking agent is at least one crosslinking agent selected from the group consisting of urea crosslinking agents, epoxy crosslinking agents, melamine crosslinking agents, isocyanate crosslinking agents, oxazoline crosslinking agents, and carbodiimide crosslinking agents. Item 4. The easily adhesive polyester film for optics according to item 3.
Item 5.
The optical layer formed by laminating a hard coat layer made of an electron beam, an ultraviolet curable acrylic resin, or a siloxane-based thermosetting resin on the coating layer of the optically easy-adhesive polyester film according to any one of Items 1 to 4. Laminated polyester film.
Item 6.
The transparent conductive film which has a transparent conductive thin film in the side which has the said application layer of the easily adhesive polyester film for optics in any one of claim | item 1-4, or the other side.
Item 7.
The transparent conductive film which has a transparent conductive thin film in the side which laminated | stacked the hard-coat layer of the laminated polyester film for optics of claim | item 5, or the other side.
Item 8.
Item 8. A capacitive or resistive touch panel using the transparent conductive film according to Item 6 or 7.
Item 9.
Item 9. A liquid crystal display device comprising at least the touch panel according to item 8 and a white light emitting diode as a backlight light source.

The easily adhesive polyester film for optics of the present invention can suppress the occurrence of color spots and ensure good visibility even when the display screen is observed through a polarizing plate such as sunglasses.
In addition, the optically easy-adhesive polyester film of the present invention is excellent in suppression of interference spots due to reflected light at both interfaces contacting the coating layer when the hard coat layer is laminated on the easy-adhesive layer of the film, and the hard coat layer In addition to excellent adhesion and high-temperature and high-humidity adhesion (moisture and heat resistance), it is possible to remarkably suppress the abrasion of the coating layer. Therefore, it is suitable as a base film for an optically laminated polyester film in which a hard coat layer is laminated.

  The polyester film used as the optically easy-adhesive polyester film of the present invention is preferably an oriented polyester film having a retardation of 3000 to 30000 nm. When the retardation is less than 3000 nm, when the screen is observed through a polarizing plate such as sunglasses, a strong interference color is exhibited. Therefore, the envelope shape is different from the emission spectrum of the light source, and good visibility cannot be ensured. The preferred lower limit of retardation is 4500 nm, the next preferred lower limit is 5000 nm, the more preferred lower limit is 6000 nm, the still more preferred lower limit is 8000 nm, and the still more preferred lower limit is 10,000 nm. On the other hand, the upper limit of retardation is 30000 nm. Even if a polyester film having a retardation of more than that is used, it is not only possible to substantially improve the visibility, but also because the film thickness becomes considerably thick and the handling property as an industrial material is reduced, it is preferable. Absent.

The optically easy-adhesive polyester film of the present invention can be suitably used for an optical film in a liquid crystal display device, particularly a base film of a touch panel, or a front surface position of a display screen of a liquid crystal display device, etc. Even when the liquid crystal display screen is observed through a polarizing plate such as the above, color spots due to retardation are suppressed, and excellent visibility can be secured. From the viewpoint of ensuring good visibility, it is preferable to use the optically easy-adhesive polyester film of the present invention in a liquid crystal display device having a white light emitting diode (white LED) as a backlight light source. The white LED is a phosphor type, that is, an element or an organic light emitting diode (OLED) that emits white by combining a phosphor with a light emitting diode that emits blue light or ultraviolet light using a compound semiconductor. In particular, white light-emitting diodes composed of light-emitting elements that combine blue light-emitting diodes using compound semiconductors with yttrium, aluminum, and garnet yellow phosphors have a continuous and broad emission spectrum in the visible light region and emit light. Since it is also excellent in efficiency, it is suitable as a backlight light source. Further, since white LEDs with low power consumption can be widely used, it is possible to achieve an energy saving effect.

  Fluorescent tubes such as cold-cathode tubes and hot-cathode tubes that have been widely used as backlight light sources have a discontinuous emission spectrum that has a peak at a specific wavelength. In some cases, sufficient visibility cannot be secured when the screen is observed.

The mechanism is considered as follows. When a birefringent polyester film is placed between two polarizing plates (a polarizing plate of a liquid crystal display device and a polarizing plate of sunglasses), the linearly polarized light emitted from the polarizing plate of the liquid crystal display device passes through the polyester film. Disturbance occurs and light is transmitted. The transmitted light shows an interference color peculiar to retardation which is the product of birefringence and thickness of the polyester film. At this time, when a white LED having a continuous emission spectrum is used as the light source, the envelope shape of the spectrum of the transmitted light indicating the interference color is approximated to the emission spectrum of the light source by controlling the polyester film to a specific retardation range. It becomes possible to make it. This is considered to improve the visibility.

  The polyester film retardation can be obtained by measuring the refractive index and thickness in the biaxial direction, or can be obtained by using a commercially available automatic birefringence measuring device such as KOBRA-21ADH (Oji Scientific Instruments).

  The polyester film can be obtained using polyethylene terephthalate or polyethylene naphthalate, but may contain other copolymerization components. These resins are excellent in transparency and excellent in thermal and mechanical properties, and the retardation can be easily controlled by stretching. In particular, polyethylene terephthalate is the most suitable material because it has a large intrinsic birefringence and a large retardation can be obtained relatively easily even if the film is thin.

  The polyester film may be a single layer or a multilayer. Moreover, as long as it exists in the range with the effect of this invention, each of these layers can contain various additives in a polyester resin as needed. Examples of the additive include an antioxidant, a light resistance agent, an antigelling agent, an organic wetting agent, an antistatic agent, an ultraviolet absorber, and a surfactant.

  Also, in order to improve the handling properties such as film slipperiness, rollability and blocking resistance, and wear properties such as wear resistance and scratch resistance, the polyester film of the base material contains inert particles. There is. However, since the film of the present invention is used as a base film for an optical member, it is required to have excellent handling properties while maintaining high transparency. Specifically, when used as an optical member, the transparency is preferably such that the total light transmittance of the optically easy-adhesive polyester film is 85% or more, more preferably 87% or more, and further 88% or more. Preferably, 89% or more is even more preferable, and 90% or more is particularly preferable.

  For high definition, the content of inert particles in the base film is preferably as small as possible. Therefore, it is preferable to make a multilayer structure in which particles are contained only in the surface layer of the film, or to contain fine particles only in the coating layer without substantially containing particles in the film.

  In particular, from the viewpoint of transparency, when an inert particle is practically not contained in the polyester film, an inorganic and / or heat-resistant polymer particle is contained in the aqueous coating solution in order to improve the handleability of the film. It is important to form irregularities on the surface of the coating layer.

  Note that “substantially no inert particles” means, for example, in the case of inorganic particles, when the element derived from the particles is quantitatively analyzed by fluorescent X-ray analysis, 50 ppm or less, preferably 10 ppm or less, Preferably, the content is below the detection limit. This means that even if particles are not actively added to the base film, contaminants derived from foreign substances and raw material resin or dirt adhering to the line or equipment in the film manufacturing process will be peeled off and mixed into the film. It is because there is a case to do.

  In addition, when the base film has a multilayer structure, the intermediate layer does not substantially contain inert particles, and the outermost layer contains inert particles only in the two- and three-layer structure. It is preferable that both can be achieved.

(Coating layer)
The easily adhesive film for optics of the present invention includes a polyester containing naphthalene dicarboxylic acid as an acid component and a dicarboxylic acid component represented by the following formula (1) and / or a diol component represented by the following formula (2). It is important to provide a coating layer containing a resin, metal oxide particles (particle A) having a refractive index of 1.7 to 3.0 and particles (particle B) having an average particle size of 200 nm to 700 nm. That is, according to the following achievement means of the present invention.
(1) HOOC- (CH ₂ ) n —COOH (where n is an integer of 4 ≦ n ≦ 10)
(2) HO— (CH ₂ ) n —OH (where n is an integer of 4 ≦ n ≦ 10)

(1) Refractive index control of coating layer In the optically easy-adhesive film of the present invention, it is necessary to adjust the refractive index of the coating layer in the vicinity of the middle between the hard coat layer and the base polyester film. Since the refractive index of the hard coat layer varies depending on the composition of the resin used in the hard coat layer, it is desirable to adjust the refractive index of the coating layer accordingly. It is necessary to adjust to the range of 6 to 1.7. By doing in this way, each interface refractive index difference is made small and interference spots are suppressed. In general, a coating layer having easy adhesion has a low refractive index (around 1.50). Therefore, in order to control the refractive index of the coating layer within the above range, in this application, naphthalenedicarboxylic acid is used as an acid component for the resin used in the coating layer. Further, metal oxide particles (particle A) having a refractive index of 1.7 or more and 3.0 or less are added. With such a configuration, it is possible to obtain a coating layer having a high refractive index while having adhesion. Details of these compositions will be described later.

(2) Particles having an average particle diameter of 200 nm to 700 nm (Particle B)
As a result of intensive studies on the composition of the coating layer, the present inventor found an effect of suppressing interference spots by adding particles (particles B) having an average particle size of 200 nm to 700 nm to the coating layer, and reached the present invention. As a reason why the particle B has such an effect, the present inventors consider as follows. By adding particles having a relatively large average particle diameter to the coating layer, irregularities are formed at the interface between the coating layer and the hard coat layer. Such an uneven structure causes light scattering at the interface between the coating layer and the hard coat layer. Such random light scattering is considered to cause disorder in the phase of the reflected light generated at the interface between the coating layer and the base polyester film, resulting in an effect of suppressing interference spots. Since the coating layer of the optically easy-adhesive film of this application has such a configuration, it is not necessary to control the coating thickness as in the prior art, and it can be applied to a wide range of coating solutions for forming a hard coat layer consisting of various solvents. It became.

  Moreover, it discovered that adhesiveness with a hard-coat layer improved as an effect which added the particle | grains B to the application layer. This is considered to be because the formation of irregularities at the interface between the coating layer and the hard coat layer increases the interface area between the coating layer and the hard coat layer, which has an advantageous effect on adhesion.

In order for the particles B to exhibit the above effects, the thickness of the coating layer is preferably smaller than the average particle size of the particles B, and the thickness of the coating layer is preferably less than 1/1 of the average particle size of the particles B, 1/2 The following is more preferable. Moreover, 1/15 or more of the average particle diameter of the particle | grains B is preferable, as for the thickness of an application layer, 1/10 or more is more preferable, and 1/7 or more is further more preferable. When the thickness of the coating layer is less than 1/15 of the average particle diameter of the particles B, the transparency may be lowered.

(3) Polyester resin containing a long-chain dicarboxylic acid component and / or diol component The coating layer of the present invention uses a relatively hard polyester resin containing a naphthalenedicarboxylic acid component as described above, while having an average particle size of 200 nm. A relatively large particle of 700 nm or less is used. Therefore, when the line speed in the post-processing increases due to the improvement of productivity efficiency, it is considered that the coating layer is scraped or the particles are dropped. Therefore, as a result of intensive studies, the present inventor has found that the use of a long-chain dicarboxylic acid component and / or a diol component as a component of the polyester resin exhibits remarkable abrasion resistance of the coating layer.

That is, the polyester resin used for the coating layer of the present invention includes naphthalenedicarboxylic acid as an acid component, and a dicarboxylic acid component represented by the following formula (1) and / or a diol component represented by the following formula (2). .
(1) HOOC- (CH ₂ ) n —COOH (where n is an integer of 4 ≦ n ≦ 10)
(2) HO— (CH ₂ ) n —OH (where n is an integer of 4 ≦ n ≦ 10)

  Thus, by including an acid component and / or a diol component having a carbon component of a specific length, the polyester resin is given flexibility, and even a relatively large particle can be easily retained, and the coating layer Can be remarkably suppressed. On the other hand, if n is less than 4, such an effect cannot be obtained, and the wear of the coating layer may occur. Moreover, when n exceeds 10, the refractive index which a polyester resin show | plays will fall, and the suppression effect of the iris-like color under a fluorescent lamp may become inadequate. The upper limit of n is more preferably 9 or less, and further preferably 8 or less.

  Here, the abrasion resistance of the coating layer can be measured by a measurement method described later. That is, in the abrasion resistance test of the coating layer to be described later, it is preferably less than or equal to the extent that powder fall can be slightly confirmed depending on the location on the black mount, and more preferably powder fall cannot be confirmed on the black mount (that is, That is, there is no powder falling off in the abrasion resistance test of the coating layer described later). The degree of powder falling can be confirmed by visual observation, fluorescent X-ray analysis, XMA, ESCA or the like. Here, “no powder fall-off” means that when the powder is inorganic particles, more specifically, the inorganic particles on the mount are below the detection limit in the fluorescent X-ray analysis.

  The present invention controls the iris-like color under a fluorescent lamp while maintaining the adhesiveness with the hard coat layer and the adhesiveness under high temperature and high humidity (humidity and heat resistance) according to the above aspect, and is excellent. Abrasion resistance of the coating layer. Further, the configuration of the present invention will be described in detail below.

  In this invention, it is necessary to contain a polyester resin in an application layer, and it is necessary to contain naphthalene dicarboxylic acid as an acid component of the said polyester resin. By including naphthalenedicarboxylic acid, the refractive index increases and it becomes easy to control the iris color under a fluorescent lamp. In addition, the moisture and heat resistance can be improved.

As such naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid is preferable. The proportion of the naphthalenedicarboxylic acid in the polyester resin is preferably 20 mol% or more, more preferably 30 mol% or more, further preferably 50 mol% or more, and still more preferably 60 mol% or more as the acid component. The proportion of the naphthalenedicarboxylic acid in the polyester resin is preferably 90 mol% or less, more preferably 85 mol% or less, and further preferably 80 mol% or less as the acid component. The proportion of the naphthalenedicarboxylic acid in the polyester resin is appropriately adjusted so that the refractive index of the coating layer together with the particles A is in the above-mentioned range. May decrease. Moreover, when it exceeds 90 mol%, the adhesiveness of resin may fall.

Further, the polyester resin of the present invention needs to contain at least naphthalenedicarboxylic acid, a dicarboxylic acid component of the following formula (1) and / or a diol component of the following formula (2) as an acid component. The dicarboxylic acid component of the following formula (1) and / or the diol component of the following formula (2) in the polyester resin is preferably 10 mol% or more, more preferably 15 mol% or more, and further preferably 20 mol% or more. Further, the dicarboxylic acid component of the following formula (1) and / or the diol component of the following formula (2) in the polyester resin is preferably 70 mol% or less, more preferably 60 mol% or less, and even more preferably 50 mol% or less. . When the dicarboxylic acid component of the following formula (1) and / or the diol component of the following formula (2) in the polyester resin is less than 10 mol%, the abrasion resistance of the coating layer may be deteriorated depending on the ratio of other components. If it is 70 mol% or more, the refractive index is lowered, and the effect of suppressing iris-like color under a fluorescent lamp may be insufficient. In addition, about the structural component of a polyester resin, it can carry out suitably also by NMR and a mass spectrometer.
(1) HOOC- (CH ₂ ) n —COOH (where n is an integer of 4 ≦ n ≦ 10)
(2) HO— (CH ₂ ) n —OH (where n is an integer of 4 ≦ n ≦ 10)

  Examples of the dicarboxylic acid component of the formula (1) include adipic acid, sebacic acid, azelaic acid and the like. Examples of the diol component of the formula (2) include butanediol and hexanediol.

  The polyester resin is based on water or a water-soluble organic solvent (for example, an aqueous solution containing less than 50% by weight of alcohol, alkyl cellosolve, ketone, or ether) or an organic solvent (for example, toluene, ethyl acetate, etc.). Those dissolved or dispersed can be used.

  When the polyester resin is used as an aqueous coating liquid, a water-soluble or water-dispersible polyester resin is used. For such water-solubilization or water-dispersion, a compound containing a sulfonate group or a carboxyl group is used. It is preferable to copolymerize a compound containing an acid base.

  In addition, as long as the effects of the present invention are achieved, the acid component in the polyester resin may further include terephthalic acid, isophthalic acid, phthalic acid, phthalic anhydride, 1,4-cyclohexanedicarboxylic acid, trimellitic acid, pyromellitic acid Dimer acid, 5-sodium sulfoisophthalic acid, 4-sodium sulfonaphthalene-2,7-dicarboxylic acid and the like may be used. Examples of the diol component include ethylene glycol, propane glycol, neopentyl glycol, diethylene glycol, 1,4-cyclohexanedimethanol, xylene glycol, ethylene oxide adduct of bisphenol A, and the like.

  The polyester resin is preferably contained in the coating layer in an amount of 30% by mass to 90% by mass in the total solid components. More preferably, it is 40% by mass or more and 80% by mass or less. When the content of the polyester resin is large, the adhesion with the hard coat layer under high temperature and high humidity decreases, and conversely, when the content is small, the adhesion with the polyester film under normal temperature and high temperature and high humidity. Sex is reduced.

  In the present invention, a crosslinking agent may be included in order to form a crosslinked structure in the coating layer. By containing a crosslinking agent, it becomes possible to further improve the adhesion under high temperature and high humidity. Moreover, since the solvent resistance to the hard coat coating solution solvent is improved by introducing a cross-linked structure into the coating layer, it is possible to more suitably suppress the occurrence of interference fringes due to variations in the coating layer thickness. Examples of the crosslinking agent include urea, epoxy, melamine, isocyanate, oxazoline, carbodiimide, and the like. Among these, melamine-based, isocyanate-based, oxazoline-based, and carbodiimide-based ones are preferable from the viewpoint of the stability over time of the coating liquid and the effect of improving adhesion under high-temperature and high-humidity treatment. Moreover, in order to promote a crosslinking reaction, a catalyst etc. are used suitably as needed.

  As content in the application layer of a crosslinking agent, 5 to 50 mass% is preferable in all the solid components. More preferably, it is 10 mass% or more and 30 mass% or less. When the amount is small, the strength of the resin of the coating layer decreases, and the adhesion at high temperature and high humidity decreases.When the amount is large, the flexibility of the resin of the coating layer decreases and at room temperature, high temperature and high humidity. The adhesiveness of is reduced.

In the present invention, it is necessary to include metal oxide particles (particle A) having a refractive index of 1.7 or more and 3.0 or less in the coating layer. Examples of such metal oxides include TiO ₂ (refractive index 2.7), ZnO (refractive index 2.0), Sb ₂ O ₃ (refractive index 1.9), SnO ₂ (refractive index 2.1), ZrO ₂ (refractive index 2.4), Nb ₂ O ₅ (refractive index 2.3), CeO ₂ (refractive index 2.2), Ta ₂ O ₅ (refractive index 2.1), Y ₂ O ₃ (refractive) 1.8), La ₂ O ₃ (refractive index 1.9), In ₂ O ₃ (refractive index 2.0), Cr ₂ O ₃ (refractive index 2.5), etc., and including these metal atoms Examples include composite oxides. The coating layer of the present invention contains at least one or more of these metal oxides. If the refractive index of the metal oxide particles is 1.7 or more, it is preferable in that the refractive index of the coating layer is adjusted within the above range. Moreover, if the refractive index of a metal oxide particle is 3.0 or less, it is preferable at the point which maintains the transparency of a film.

  The content of the metal oxide particles in the coating layer is preferably controlled by the relationship between the refractive index of the metal oxide particles to be used and the refractive index of the hard coat layer to be applied. Specifically, in the total solid component, 2 mass% or more, More preferably, 5 mass% or more and 70 mass% or less are preferable. As a minimum of content of metal oxide particles, 7 mass% or more is more preferred, and 8 mass% or more is still more preferred. Moreover, as an upper limit of content of a metal oxide particle, 50 mass% or less is more preferable, 30 mass% or less is more preferable, 20 mass% or less is further more preferable, 15 mass% or less is especially preferable. Depending on the refractive index of the hard coat layer, metal oxide particles are added within the above range, and the refractive index of the coating layer is adjusted in the range of 1.5 to 1.7, preferably in the range of 1.6 to 1.7. To do. If the content of the metal oxide particles is less than 2% by mass or less than 5% by mass, it may be difficult to adjust the refractive index of the coating layer to the above range. Further, if the content of the metal oxide particles exceeds 70% by mass, the adhesion of the coating layer may be lowered, which is not preferable. The average particle diameter of the metal oxide particles is not particularly limited, but is preferably 1 to 100 nm from the viewpoint of maintaining the transparency of the film.

  In the present invention, it is necessary to contain particles (particle B) having an average particle size of 200 nm or more and 700 nm or less in the coating layer. Particle B is (1) silica, kaolinite, talc, light calcium carbonate, heavy calcium carbonate, zeolite, alumina, barium sulfate, carbon black, zinc oxide, zinc sulfate, zinc carbonate, titanium dioxide, satin white, aluminum silicate, Inorganic particles such as diatomaceous earth, calcium silicate, aluminum hydroxide, hydrous halloysite, magnesium carbonate, magnesium hydroxide, (2) acrylic or methacrylic, vinyl chloride, vinyl acetate, nylon, styrene / acrylic, styrene / Butadiene, polystyrene / acrylic, polystyrene / isoprene, polystyrene / isoprene, methyl methacrylate / butyl methacrylate, melamine, polycarbonate, urea, epoxy, urethane, phenol, Allyl phthalate, and organic particles of a polyester or the like.

  The particles (particles B) preferably have an average particle size of 200 to 700 nm. When the particle size is small, the unevenness formation at the interface between the coating layer and the hard coat layer is small, the scattering effect is reduced, and the effect of suppressing the iris color under a fluorescent lamp tends to be insufficient. If it is large, the transparency of the coating layer may deteriorate.

  The particles (particles B) are preferably spherical particles that hardly aggregate. When the particles are aggregated, the effect of scattering is reduced, and not only the effect of suppressing the iris-like color under the lamp tends to be insufficient, but also an optical defect may occur. Also, the spherical particles are considered preferable from the viewpoint of exhibiting the light scattering effect by the particles. Moreover, it is preferable that the particle | grains B are colorless and transparent from the point which maintains the transparency of a film.

  The average particle diameter of the particles in the coating layer of the present invention is 10 or more present in the section of the coating layer by photographing a cross section of the easy-adhesive film at a magnification of 120,000 using a transmission electron microscope (TEM). The maximum diameter of the particles can be measured, and the average value thereof can be obtained. In that case, in order to exclude foreign substances and particles of particles A, it is preferable to select particles of 100 nm or more and obtain an average.

  As content in the application layer of particle | grains B, 0.5 to 5 mass% is preferable in all the solid components. As an upper limit of content in the application layer of particle | grains B, 4 mass% or less is more preferable, 3 mass% or less is more preferable, and 2 mass% or less is especially preferable. When the amount is small, the scattering effect is reduced, and the effect of suppressing iris-like colors under a fluorescent lamp tends to be insufficient. When the amount is large, not only the transparency of the coating layer is deteriorated but also the film strength is lowered.

  The coating layer may contain a surfactant for the purpose of improving leveling properties during coating and defoaming the coating solution. The surfactant may be any of cationic, anionic and nonionic surfactants, but is preferably a silicon-based, acetylene glycol-based or fluorine-based surfactant. These surfactants are preferably contained in the coating layer within a range that does not impair the effect of suppressing the iris-like color and the adhesion under a fluorescent lamp.

  In order to impart other functionality to the coating layer, various additives may be included in a range that does not impair the effect of suppressing iris color and adhesion under a fluorescent lamp. Examples of the additive include fluorescent dyes, fluorescent brighteners, plasticizers, ultraviolet absorbers, pigment dispersants, foam suppressors, antifoaming agents, and preservatives.

  In the present invention, examples of the method for providing the coating layer on the polyester film include a method in which a coating solution containing a solvent, particles and a resin is applied to the polyester film and dried. Examples of the solvent include organic solvents such as toluene, water, and a mixed system of water and a water-soluble organic solvent. Preferably, water alone or a mixture of a water-soluble organic solvent and water is used from the viewpoint of environmental problems. preferable.

(Laminated polyester film for optics)
The laminated polyester film for optics of the present invention can be obtained by providing a hard coat layer made of an electron beam, an ultraviolet curable acrylic resin, or a siloxane thermosetting resin on the above-described polyester film coating layer.

  As an acrylic resin that is cured by electron beam or ultraviolet ray, it has an acrylate functional group, for example, a relatively low molecular weight polyester resin, polyether resin, acrylic resin, epoxy resin, urethane resin, alkyd resin, spiroacetal. Resin, polybutadiene resin, polythiol polyene resin, oligomers or prepolymers of polyfunctional compounds such as polyhydric alcohol (meth) acrylate, etc. and reactive diluents such as ethyl (meth) acrylate, ethylhexyl (meth) acrylate, styrene, methylstyrene Monofunctional monomers such as N-vinylpyrrolidone and polyfunctional monomers such as trimethylolpropane tri (meth) acrylate, hexanediol (meth) acrylate, tripropylene glycol di (meth) Contains acrylate, diethylene glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, etc. Things can be used.

  However, in the case of an electron beam or ultraviolet curable resin, as a photopolymerization initiator in the above-mentioned resin, acetophenones, benzophenones, Michler benzoylbenzoate, α-amyloxime ester, tetramethyltyramium monosulfide, thioxanthone In addition, n-butylamine, triethylamine, tri-n-butylphosphine and the like can be used as a photosensitizer.

  The siloxane-based thermosetting resin can be produced by hydrolyzing and condensing a single or two or more organosilane compounds in the presence of an acid or base catalyst. In particular, in the case of low reflection, it is better to improve the low refractive index and stain resistance by mixing and hydrolyzing and condensing one or more fluorosilane compounds.

(Manufacture of easily adhesive polyester film for optics)
The easily adhesive polyester film for optics of the present invention can be manufactured according to a general method for manufacturing a polyester film. For example, the polyester resin is melted and the non-oriented polyester extruded and formed into a sheet shape is stretched in the longitudinal direction by utilizing the speed difference of the roll at a temperature equal to or higher than the glass transition temperature, and then stretched in the transverse direction by a tenter. The method of performing heat processing is mentioned.

  The polyester film of the present invention may be a uniaxially stretched film or a biaxially stretched film, but when the biaxially stretched film is used as a protective film on the front surface of the liquid crystal panel, it is observed from directly above the film surface. However, rainbow-like color spots are not seen, but care must be taken because rainbow-like color spots may be observed when observed from an oblique direction.

  This phenomenon is that a biaxially stretched film is composed of refractive index ellipsoids having different refractive indexes in the running direction, width direction, and thickness direction, and the retardation becomes zero depending on the light transmission direction inside the film (refractive index ellipse). This is because there is a direction in which the body appears to be a perfect circle. Therefore, when the liquid crystal display screen is observed from a specific oblique direction, a point where the retardation becomes zero may be generated, and a rainbow-like color spot is generated concentrically around that point. When the angle from the position directly above the film surface (normal direction) to the position where the rainbow-like color spots are visible is θ, the angle θ increases as the birefringence in the film increases, and the rainbow-like color increases. Spots are difficult to see. The biaxially stretched film tends to reduce the angle θ, and therefore the uniaxially stretched film is more preferable because rainbow-like color spots are less visible.

  However, a perfect uniaxial (uniaxial symmetry) film is not preferable because the mechanical strength in the direction orthogonal to the orientation direction is significantly reduced. The present invention has biaxiality (biaxiality) in a range that does not substantially cause rainbow-like color spots or a range that does not cause rainbow-like color spots in a viewing angle range required for a liquid crystal display screen. It is preferable.

  As a means for suppressing the occurrence of iridescent colored spots while maintaining the mechanical strength of the optically easy-adhesive polyester film, the inventors of the present invention have a retardation (in-plane retardation) of the optically-adhesive polyester film. It has been found that the ratio to the retardation (Rth) in the thickness direction is controlled to fall within a specific range. Thickness direction retardation means an average of retardation obtained by multiplying two birefringences ΔNxz and ΔNyz by film thickness d when the film is viewed from the cross section in the thickness direction. The smaller the difference between the in-plane retardation and the thickness direction retardation, the more isotropic the birefringence action due to the observation angle, and the smaller the change in retardation due to the observation angle. Therefore, it is considered that rainbow-like color spots due to the observation angle are less likely to occur.

  The ratio (Re / Rth) of retardation and thickness direction retardation of the polyester film of the present invention is preferably 0.200 or more, more preferably 0.500 or more, and further preferably 0.600 or more. As the ratio of the retardation to the retardation in the thickness direction (Re / Rth) is larger, the birefringence action is more isotropic, and the occurrence of iridescent color spots due to the observation angle is less likely to occur. In a complete uniaxial (uniaxial symmetry) film, the ratio of the retardation to the retardation in the thickness direction (Re / Rth) is 2.0. However, as described above, the mechanical strength in the direction orthogonal to the orientation direction is significantly lowered as the film approaches a complete uniaxial (uniaxial symmetry) film.

  On the other hand, the ratio of the retardation of the polyester film of the present invention to the retardation in the thickness direction (Re / Rth) is preferably 1.2 or less, more preferably 1.0 or less. In order to completely suppress the occurrence of rainbow-like color spots due to the observation angle, the ratio of the retardation to the thickness direction retardation (Re / Rth) does not have to be 2.0, and 1.2 or less is sufficient. is there. Moreover, even if the ratio is 1.0 or less, it is possible to satisfy the viewing angle characteristics required for the liquid crystal display screen (left and right 180 °, up and down 120 °).

  Describing specifically the film forming conditions of the polyester film of the present invention, the longitudinal stretching temperature and the transverse stretching temperature are preferably from 80 to 130 ° C, particularly preferably from 90 to 120 ° C. The longitudinal draw ratio is preferably 1.0 to 3.5 times, particularly preferably 1.0 to 3.0 times. The transverse draw ratio is preferably 2.5 to 6.0 times, and particularly preferably 3.0 to 5.5 times. In order to control the retardation within the above range, it is preferable to control the ratio of the longitudinal draw ratio and the transverse draw ratio. If the difference between the vertical and horizontal draw ratios is too small, it is difficult to increase the retardation, which is not preferable. Also, setting the stretching temperature low is a preferable measure for increasing the retardation. In the subsequent heat treatment, the treatment temperature is preferably from 100 to 250 ° C, particularly preferably from 180 to 245 ° C.

  In order to suppress retardation fluctuation, it is preferable that the thickness unevenness of the film is small. Since the stretching temperature and the stretching ratio greatly affect the thickness variation of the film, it is necessary to optimize the film forming conditions from the viewpoint of the thickness variation. In particular, when the longitudinal draw ratio is lowered to increase the retardation, the longitudinal thickness unevenness may be deteriorated. Since there is a region where the vertical thickness unevenness becomes very bad in a specific range of the draw ratio, it is desirable to set the film forming conditions outside this range.

  The thickness unevenness of the film of the present invention is preferably 5.0% or less, more preferably 4.5% or less, still more preferably 4.0% or less, and 3.0% or less. It is particularly preferred.

  As described above, in order to control the retardation of the film within a specific range, the stretching ratio, the stretching temperature, and the thickness of the film can be appropriately set. For example, the higher the stretching ratio, the lower the stretching temperature, and the thicker the film, the higher the retardation. Conversely, the lower the stretching ratio, the higher the stretching temperature, and the thinner the film, the lower the retardation. However, when the thickness of the film is increased, the thickness direction retardation tends to increase. Therefore, it is desirable to set the film thickness appropriately within the range described below. In addition to controlling the retardation, it is necessary to set final film forming conditions in consideration of physical properties necessary for processing.

  Although the thickness of a polyester film is arbitrary, the range of 15-300 micrometers is preferable, More preferably, it is the range of 15-260 micrometers. In principle, it is possible to obtain a retardation of 3000 nm or more even with a film having a thickness of less than 15 μm. However, in that case, the anisotropy of the mechanical properties of the film becomes remarkable, and it becomes easy to cause tearing, tearing, etc., and the practicality as an industrial material is remarkably lowered. A particularly preferable lower limit of the thickness is 25 μm. On the other hand, if the upper limit of the thickness of the polyester film exceeds 300 μm, the handleability as an industrial material is lowered, which is not preferable. From the viewpoint of practicality as an easily adhesive polyester film for optics, the upper limit of the thickness is preferably 260 μm.

  In order for the polyester film of this invention to provide handling property (for example, winding-up property after lamination | stacking), it is preferable to make a film contain particle | grains and to form a processus | protrusion on the film surface. As particles to be included in the film, inorganic particles such as silica, kaolinite, talc, calcium carbonate, zeolite, alumina, etc., heat resistant polymer particles such as acrylic, PMMA, nylon, polystyrene, polyester, benzoguanamine / formalin condensate, etc. Is mentioned. From the viewpoint of transparency, the content of particles in the film is preferably small, for example, preferably 1 ppm or more and 1000 ppm or less. Furthermore, it is preferable to select particles having a refractive index close to that of the resin used from the viewpoint of transparency. Moreover, in order to provide various functions as needed, the film may contain a light-resistant agent (ultraviolet ray inhibitor), a pigment, an antistatic agent, and the like.

  In an arbitrary stage of the film manufacturing process, a coating solution is applied to at least one surface of the polyester film to form the coating layer. The coating layer may be formed on one side of the polyester film or on both sides. The solid content concentration of the resin composition in the coating solution is preferably 2 to 35% by weight, particularly preferably 4 to 15% by weight.

  Any known method can be used as a method for applying the coating solution to the polyester film. For example, reverse roll coating method, gravure coating method, kiss coating method, die coater method, roll brush method, spray coating method, air knife coating method, wire bar coating method, pipe doctor method, impregnation coating method, curtain coating method, etc. It is done. These methods are applied alone or in combination.

  In the present invention, the coating layer is formed by coating the coating solution on an unstretched or uniaxially stretched PET film, drying it, stretching in at least a uniaxial direction, and then performing a heat treatment.

In the present invention, the finally obtained coating layer preferably has a thickness of 20 to 350 nm, and the coating amount after drying is preferably 0.02 to 0.5 g / m ² . When the coating amount of the coating layer is less than 0.02 g / m ² , not only the effect on adhesiveness is almost lost, but also the suppression of iris color under a fluorescent lamp tends to be insufficient. On the other hand, if the coating amount exceeds 0.5 g / m ² , the effect of suppressing iris-like colors under a fluorescent lamp tends to be insufficient.

  The coating layer of the optically easy-adhesive polyester film obtained in the present invention has good adhesion to an electron beam, a hard coat layer made of an ultraviolet curable acrylic resin or a siloxane-based thermosetting resin. Also, good adhesive strength can be obtained even for applications other than optical applications. Specifically, adhesion such as photographic photosensitive layer, diazo photosensitive layer, matte layer, magnetic layer, inkjet ink receiving layer, hard coat layer, UV curable resin, thermosetting resin, printing ink and UV ink, dry laminate, extrusion laminate, etc. Examples thereof include vacuum deposition, electron beam deposition, sputtering, ion plating, CVD, plasma polymerization and the like of an agent, a metal or an inorganic substance, or an oxide thereof, and an organic barrier layer.

(Manufacture of laminated polyester film for optics)
The method for producing an optical laminated polyester film of the present invention will be described by taking a polyester film as an example, but it is not limited to this.

  The electron beam, the ultraviolet curable acrylic resin, or the siloxane thermosetting resin is applied to the coating layer surface of the optically easy-adhesive polyester film. When the coating layer is provided on both surfaces, it is coated on at least one coating layer surface. Although it is not necessary to dilute the coating solution in particular, there is no particular problem even if it is diluted with an organic solvent as required, such as the viscosity, wettability and coating thickness of the coating solution. The coating layer is obtained by curing the coating layer by applying an electron beam or ultraviolet ray and heating according to the curing conditions of the coating solution after applying the coating solution to the above-mentioned film and drying it as necessary. Then, a hard coat layer is formed.

  In the present invention, the thickness of the hard coat layer is preferably 1 to 15 μm. When the thickness of the hard coat layer is less than 1 μm, the effects on the chemical resistance, scratch resistance, antifouling property and the like as the hard coat layer are almost lost. On the other hand, if the thickness exceeds 15 μm, the flexibility of the hard coat layer is reduced, and the possibility of cracks and the like increases.

The optically laminated polyester film obtained in the present invention can be used for a wide range of applications. In particular, by forming an antireflection layer on the upper layer, a good antireflection film can be obtained. For forming such an antireflection layer, a single layer of an inorganic material such as ZnO, TiO ₂ , CeO ₂ , SnO ₂ , ZrO ₂ or the like having a high refractive index or MgF ₂ or SiO ₂ having a low refractive index or a metal material is used. Alternatively, it is performed by providing multiple layers. These layers are formed as a single layer or multiple layers of a coating layer made of a resin composition containing an inorganic material or a metal material having a high refractive index or a low refractive index, such as vapor deposition, sputtering, plasma CVD, or the like.

(Transparent conductive film, touch panel)
A transparent conductive thin film can be laminated | stacked on the easily adhesive polyester film for optics, and it can be set as a transparent conductive film. The transparent conductive thin film may be laminated on the coating layer side of the optically easy-adhesive polyester film according to the purpose of use, or may be laminated on the side opposite to the surface having the coating layer.

Although the method of providing the transparent conductive thin film on the polyester film may be directly laminated, it may be laminated via another layer as follows. The present invention is not limited to the following configurations (1) to (6), and an example of a preferred embodiment is shown.
(1) Polyester film / easy-adhesive layer (the above-mentioned coating layer is preferred) / transparent conductive thin film (2) Polyester film / easy-adhesion layer (the above-mentioned coating layer is preferred) / hard coat layer / transparent conductive thin film (3 ) Polyester film / Easily adhesive layer (The above-mentioned coating layer is preferable) / IM (Index matching) layer / Transparent conductive thin film (4) Polyester film / Easily adhesive layer (The above-mentioned coating layer is preferable) / Hard coat layer / IM (Index matching) layer / transparent conductive thin film (5) polyester film / adhesive layer (preferably the above-mentioned coating layer) / hard coat layer (high refractive index also serves as IM) / transparent conductive thin film where IM ( The index matching) layer is a laminated structure of high refractive index layer / low refractive index layer (transparent conductive thin film side is the low refractive index layer). It is possible to the ITO pattern difficult to see when viewed the surface.
By integrating the high refractive index layer and the hard coat layer of the IM (index matching) layer, the configuration of (4) can be simplified as described in (6) below.
(6) Polyester film / Easily adhesive layer (preferably the above-mentioned coating layer) / Hard coat layer (high refractive index) / Low refractive index layer / Transparent conductive thin film

In particular, in the case of a transparent conductive film used for a capacitive touch panel, the configuration of (3) to (6) in which an IM (index matching) layer is provided is preferable. Are preferably laminated. This makes it difficult to see the ITO patterning when viewing the liquid crystal display screen. Moreover, the structure of (2)-(6) which has a hard-coat layer from a viewpoint of preventing that an oligomer precipitates on the surface of a polyester film is preferable.

As the hard coat layer, the hard coat layer described above can be used. In order to improve the adhesion between the high refractive index layer and the hard coat layer, the hard coat layer may be further surface treated. Specific methods include a discharge treatment method that irradiates glow discharge or corona discharge, a method of increasing carbonyl group, carboxyl group, hydroxyl group, a chemical treatment method of treating with acid or alkali, and an amino group. And a method of increasing polar groups such as a hydroxyl group and a carbonyl group.

Further, for the purpose of making it difficult to see the patterning portion when viewed from an oblique direction, particles may be included in the hard coat layer so as to satisfy the following conditions.
The ratio of the image clarity of the transmission method when using the 0.125 mm optical comb defined by JIS K7105 (1999 edition) to the image clarity of the transmission method when using the 2.0 mm optical comb is 0. It is preferable to design in the range of 125 mm width comb value / 2 mm width comb value ≧ 0.7. More preferably, it is 0.8 or more. In the case of less than 0.7, when it is installed on the front surface of a display body such as a high-definition liquid crystal display, the glare phenomenon occurs and the visibility is lowered.

The particles to be included in the hard coat layer are not particularly limited, but inorganic particles (for example, silica, calcium carbonate, etc.), heat-resistant organic particles (for example, silicon particles, PTFE particles, polyimide particles, etc.), crosslinked polymer particles ( Cross-linked PS particles, cross-linked acrylic particles, etc.). The average particle diameter (by electron microscopy) of these particles is preferably 0.05 to 5 μm, and more preferably 0.1 to 2 μm. When the average particle size is less than 0.05 μm, there is little effect of making the patterning portion difficult to see when viewed from an oblique direction, and when the average particle size exceeds 5 μm, it is installed on the front surface of a display such as a high-definition liquid crystal display. In such a case, the glare phenomenon may occur and visibility may deteriorate.

(High refractive index layer)
The refractive index of the high refractive index layer is preferably in the range of 1.60 to 2.50, more preferably 1.70 to 2.50, and even more preferably 1.9 to 2.3. If it is less than 1.60, the difference in refractive index from the low refractive index layer is too small, so that when the transparent conductive thin film layer is patterned, the optical characteristics of the portion having the transparent conductive thin film layer and the portion not having it may be brought closer. It tends to be difficult. On the other hand, when the refractive index exceeds 2.50, it tends to be difficult to reduce the visibility of patterning in an oblique direction. Specific materials for the high refractive index layer include TiO ₂ , Nb ₂ O ₅ , ZrO ₂ , Ta ₂ O ₅ , ZnO, In ₂ O ₃ , SnO _2, and complex oxides thereof. Among these, ZnO, In ₂ O ₃ , SnO ₂ and composite oxides thereof are preferable from the viewpoint of productivity.

The film thickness of the high refractive index layer is preferably 4 to 100 nm. When the film thickness is less than 4 nm, the film becomes discontinuous and the stability of the film decreases. On the other hand, when the film thickness exceeds 100 nm, the reflection of light becomes strong. Therefore, when the transparent conductive thin film layer is patterned, it becomes difficult to bring the optical characteristics of the portion having the transparent conductive thin film layer close to the portion not having the transparent conductive thin film layer, When it is arranged on the front surface of a display body such as a liquid crystal display, the patterning of the transparent conductive thin film layer is visible and the visibility is lowered.

As a method for forming a high refractive index layer in the present invention, a vacuum deposition method, a sputtering method, a CVD method, an ion plating method, a spray method, and the like are known. Can be used as appropriate, but sputtering is preferred from the viewpoint of reducing variations in film thickness.
In general, the sputtering method includes a reactive sputtering method in which a reactive gas is introduced from a metal target to produce a metal oxide, and a method in which a metal oxide is formed from an oxide target. In the reactive sputtering method, there is a transition region in which the film formation rate changes rapidly depending on the flow rate of the reactive gas. For this reason, it is preferable to use an oxide target in order to suppress variations in film thickness.

(Low refractive index layer)
The refractive index of the low refractive index layer is preferably 1.20 to 1.60, more preferably 1.30 to 1.60, and still more preferably 1.4 to 1.5. When the refractive index is less than 1.20, a porous film is formed, so that the electrical characteristics of the transparent conductive thin film layer formed thereon are deteriorated. On the other hand, when the refractive index exceeds 1.60, the interference of light with the transparent conductive thin film layer becomes too weak. Therefore, when the transparent conductive thin film layer is patterned, a portion having the transparent conductive thin film layer and a portion having no transparent conductive thin film layer It becomes difficult to make the optical characteristics close to each other, and when it is arranged on the front surface of a display body such as a liquid crystal display, the patterning of the transparent conductive thin film layer is visible and the visibility is lowered.
Specific material of the low refractive index _layer, a composite metal oxide such as SiO 2, _Al 2 transparent metal oxide such as _{O 3} and _SiO 2 _-Al 2 _{O 3} and the like.

The film thickness of the low refractive index layer is preferably 5 to 100 nm. If the thickness exceeds 100 nm, the wavelength dependence becomes too strong due to light interference with the transparent conductive thin film layer. Therefore, when the transparent conductive thin film layer is patterned, the optical characteristics of the portion with and without the transparent conductive thin film layer It becomes difficult to bring close. On the other hand, when the thickness is less than 5 nm, light interference with the transparent conductive thin film layer hardly occurs and the transmittance cannot be improved. Therefore, when the transparent conductive thin film layer is patterned, the transparent conductive thin film layer and the portion having the transparent conductive thin film layer are present. It becomes difficult to bring the optical characteristics of the portion not to be close to each other, and when it is arranged on the front surface of a display body such as a liquid crystal display, the patterning of the transparent conductive thin film layer is visible and the visibility is lowered.

As a method for forming the low refractive index layer, a vacuum deposition method, a sputtering method, a CVD method, an ion plating method, a spray method, and the like are known, and the above method is appropriately used depending on the required film thickness. However, the sputtering method is preferable from the viewpoint of reducing variations in film thickness. In general, when forming by sputtering, a reactive DC or AC sputtering method is used. Impedance control for controlling the reactive gas flow rate so as to keep the voltage value of the DC or AC power source constant in order to improve the deposition rate, or the reactive gas flow rate so as to keep the emission intensity in the plasma of a specific element constant. A plasma emission method for controlling the pressure is used.

(Transparent conductive thin film layer)
Examples of transparent conductive thin films include indium oxide, tin oxide, zinc oxide, indium-tin composite oxide, tin-antimony composite oxide, zinc-aluminum composite oxide, indium-zinc composite oxide, Ag nanowire, and Ag ink. , Ag ink self-assembled conductive film, mesh electrode, IZO, Mg (OH) ₂ ; C-based, Nb-doped TiO ₂ ; H-based, nano-TiO ₂ -based, nano-ITO, CNT ink, conductive polymer, Steric 3-alkylthiophene and the like can be mentioned. Of these, indium-tin composite oxides are preferable from the viewpoints of environmental stability and circuit processability.

The film thickness of the transparent conductive thin film is preferably 1 to 100 nm, more preferably 4 to 50 nm. When the film thickness of the transparent conductive thin film is less than 1 nm, it is difficult to form a continuous thin film, and it is difficult to obtain good conductivity. On the other hand, when the film thickness of the transparent conductive thin film is thicker than 100 nm, when the transparent conductive thin film layer is patterned, it becomes difficult to bring the optical characteristics of the portion having the transparent conductive thin film layer close to the portion not having the transparent conductive thin film layer.

The transparent conductive thin film layer is preferably amorphous. When a crystalline transparent conductive thin film layer is used, it is difficult to dissolve when patterning the transparent conductive thin film with hydrochloric acid or the like, so that problems such as time consuming processing and fine patterning cannot be achieved.

In order to obtain an amorphous transparent conductive thin film layer, the amount of dopant is preferably adjusted. For example, when an indium-tin composite oxide is used as the transparent conductive thin film layer, the content of tin oxide is preferably 10 to 60% by mass, and more preferably 20 to 50% by mass. When the tin oxide content is less than 10% by mass, it becomes difficult to suppress crystallization during film formation. On the other hand, when the content of tin oxide exceeds 60% by mass, it becomes difficult to improve the density of the target, and an abnormal discharge tends to occur during production, which is not preferable from the viewpoint of productivity.

From the viewpoint of productivity, the transparent conductive thin film preferably has the same composition as the high refractive index layer. When the composition is different, the target and cathode for high refractive index and transparent conductive thin film are necessary, which makes the apparatus large in terms of equipment.

The layer structure of the transparent conductive thin film may be a single layer structure or a laminated structure of two or more layers. In the case of a transparent conductive thin film having a laminated structure of two or more layers, the metal oxides constituting each layer may be the same or different.

As a method for forming a transparent conductive thin film, a vacuum deposition method, a sputtering method, a CVD method, an ion plating method, a spray method, and the like are known, and the above method is appropriately used according to a required film thickness. be able to.
For example, in the case of the sputtering method, a normal sputtering method using an oxide target, a reactive sputtering method using a metal target, or the like is used. At this time, oxygen, nitrogen, or the like may be introduced as a reactive gas, or means such as ozone addition, plasma irradiation, or ion assist may be used in combination. In addition, a bias such as direct current, alternating current, and high frequency may be applied to the substrate as long as the object of the present invention is not impaired.

(Dielectric layer (protective layer) having a refractive index of 1.40 to 1.70)
The dielectric layer having a refractive index of 1.40 to 1.70 is an object as a protective layer to be laminated in order to protect the transparent conductive thin film when using the transparent conductive laminated film as a member of the display body, This layer has the purpose of increasing the capacitance change when touched with a finger or the like and improving the position input accuracy. The dielectric layer having a refractive index of 1.40 to 1.70, for _example, transparent metal oxide such as SiO 2, _Al 2 _{O 3} and composite metal oxides such as _SiO 2 _-Al 2 _{O 3,} acrylic, silicone Organic materials made of polyester resins are used.

The touch panel of this invention uses the above-mentioned transparent conductive film for the structural member. As the touch panel, a touch panel of a resistance film type (analog resistance film, matrix resistance film), a capacitance type (surface capacitance, projection capacitance) or the like is preferable.

In the resistive film type touch panel, a pair of panel plates having a transparent conductive thin film are arranged via a spacer so that the transparent conductive thin film faces each other. It is preferable that at least one panel board is the above-mentioned transparent conductive film (or transparent conductive sheet described later).
Of the pair of panel plates, the transparent conductive film disposed on the viewing side has a hard coat layer on the surface of the optically easy-adhesive polyester film described above (that is, the above-mentioned optical laminated polyester film), The structure which has a transparent conductive thin film in the surface which laminated | stacked the hard-coat layer, or the surface on the opposite side is preferable. As described above, a method for laminating a transparent conductive thin film on a polyester film may be performed by laminating a plurality of layers between the transparent conductive thin film and the polyester film, or by laminating directly.
Moreover, as another panel board, what laminated | stacked the transparent conductive thin film on one side of the easily adhesive polyester film for optics of this invention is preferable. The transparent conductive thin film may be laminated on the coating layer side, or may be laminated on the side opposite to the surface having the coating layer. Moreover, you may stick together a transparent resin sheet on the surface opposite to the transparent conductive thin film of a transparent conductive film through an adhesive, and use it as a transparent conductive sheet. As an adhesive, well-known things, such as an acrylic adhesive, a silicone adhesive, and a rubber adhesive, can be used. Since the transparent resin sheet is used for imparting mechanical strength similar to that of glass, the thickness is preferably 0.05 mm or more, and conventionally known ones can be used.

  EXAMPLES Next, although this invention is demonstrated in detail using an Example and a comparative example, naturally this invention is not limited to a following example. The evaluation method used in the present invention is as follows.

(1) Retardation (Re)
Retardation is a parameter defined by the product (ΔNxy × d) of the biaxial refractive index anisotropy (ΔNxy = | Nx−Ny |) and the film thickness d (nm) on the film. Yes, it is a scale showing optical isotropy and anisotropy. The biaxial refractive index anisotropy (ΔNxy) was determined by the following method. Using two polarizing plates, the orientation axis direction of the film was determined, and a 4 cm × 2 cm rectangle was cut out so that the orientation axis directions were perpendicular to each other, and used as a measurement sample. With respect to this sample, the biaxial refractive index (Nx, Ny) perpendicular to each other and the refractive index (Nz) in the thickness direction were determined by an Abbe refractometer (NAGO-4T, measurement wavelength 589 nm, manufactured by Atago Co., Ltd.). The absolute value (| Nx−Ny |) of the refractive index difference between the axes was defined as the refractive index anisotropy (ΔNxy). The thickness d (nm) of the film was measured using an electric micrometer (manufactured by Fine Reef, Millitron 1245D), and the unit was converted to nm. Retardation (Re) was determined from the product (ΔNxy × d) of refractive index anisotropy (ΔNxy) and film thickness d (nm).

(2) Thickness direction retardation (Rth)
Thickness direction retardation is obtained by multiplying two birefringences ΔNxz (= | Nx−Nz |) and ΔNyz (= | Ny−Nz |) by film thickness d when viewed from the cross section in the film thickness direction. It is a parameter which shows the average of retardation obtained. Thickness direction retardation (Rth) is obtained by calculating Nx, Ny, Nz and film thickness d (nm) in the same manner as the measurement of retardation, and calculating the average value of (ΔNxz × d) and (ΔNyz × d). )

(3) Observation of color spots The easy-to-adhesive polyester film for optics obtained in each example is obtained by using a white LED comprising a light emitting element in which a blue light emitting diode and a yttrium / aluminum / garnet yellow phosphor are combined as a light source (Nichia). Chemical, NSPW500CS) was placed on a liquid crystal display device (having a configuration in which a liquid crystal cell was sandwiched between two polarizing plates), the screen was observed through sunglasses, and evaluated according to the following evaluation criteria. The angle formed by the orientation axis of the easily adhesive polyester film for optics and the polarization axis of the viewing side polarizing plate was 45 degrees.
◎: No color spots from any direction.
○: When observed from an oblique direction, some very thin color spots can be observed.
X: Color spots can be clearly observed when observed from an oblique direction.

(4) Tear strength The tear strength of each film was measured in accordance with JIS P-8116 using an Elmendorf tear tester manufactured by Toyo Seiki Seisakusho. The tear direction was set to be parallel to the orientation axis direction of the film, and the determination was made as follows. In addition, the measurement of the orientation axis direction was measured with a molecular orientation meter (manufactured by Oji Scientific Instruments Co., Ltd., MOA-6004 type molecular orientation meter).
○: Tear strength is 50 mN or more ×: Tear strength is less than 50 mN

(5) Intrinsic viscosity Based on JIS K7367-5, it measured at 30 degreeC using the mixed solvent of a phenol (60 mass%) and 1,1,2,2-tetrachloroethane (40 mass%) as a solvent.

(6) Refractive index The refractive index of the hard coat layer was measured using an Abbe refractometer based on JISK 7142 for a film obtained by curing each resin used for the hard coat layer. The refractive index of the particles A is such that the particles A dried at 90 ° C. are suspended in various liquids of 25 ° C. having different refractive indexes, and the refractive index of the liquid in which the suspension looks most transparent is the Abbe refractive index. It was measured by a meter.

(7) Average particle diameter A sample of an optical laminated polyester film having a hard coat layer produced in the examples described later is embedded in a visible light curable resin (D-800, manufactured by JEOL Datum) and visible at room temperature. Cured by exposure to light. From the obtained embedding block, an ultrathin section having a thickness of about 70 to 100 nm was prepared using an ultramicrotome equipped with a diamond knife, and dyed in ruthenium tetroxide vapor for 30 minutes. A cross section of the hard coat layer was observed with a transmission electron microscope (TEM 2010, manufactured by JEOL Ltd.), and a photograph was taken of the stained ultrathin section. The magnification of the photograph is appropriately set in the range of 10,000 to 100,000 times. In this embodiment, the enlargement magnification is 80,000 times (acceleration voltage 200 kv). When obtaining the average particle size of the particles B, 10 or more particles having a particle size of about 100 nm or more were selected from the electron micrograph, the maximum diameter of these particles was measured, and the average value was obtained. This is to remove particles having a small particle diameter that are not clearly the particles B of the present application, such as particles A and foreign matters.

(8) Interference spot improvement (iris color)
An optical laminated polyester film having a hard coat layer produced in Examples described later was cut into an area of 10 cm (film width direction) × 15 cm (film longitudinal direction) to prepare a sample film. A black glossy tape (manufactured by Nitto Denko, vinyl tape No. 21; black) was attached to the surface of the obtained sample film opposite to the hard coat layer. Three-wavelength daylight white (National Purook, F.L15EX-N)
15W) was used as a light source, and observed in a positional relationship (distance 40 to 60 cm from the light source, an angle of 15 to 45 ° with respect to the normal of the film surface) where reflection was most intense visually from above.

The results of visual observation are ranked according to the following criteria. The observation is performed by five people who are familiar with the evaluation, and the highest rank is the evaluation rank. If two ranks have the same number, the center of the rank divided into three is adopted. For example, ◎ and ○ are 2 people each and △ is 1 person, ○ is ◎, ◎ is 1 person and ○ and △ are 2 people each, ○, ◎ and △ are 2 people each and ○ is 1 In the case of names, ○ is adopted.
◎: Iridescent colors are not observed even when observed from any angle ○: Some iris colors are observed depending on the angle △: Slightly iris colors are observed ×: Obvious iris colors are observed Be done

(9) Adhesiveness 100 masses that penetrate the hard coat layer and reach the base film using a cutter guide with a gap distance of 2 mm in the optical laminated polyester film having the hard coat layer produced in the examples described later. Make an eye-shaped cut on the surface of the hard coat layer. Next, a cellophane adhesive tape (manufactured by Nichiban Co., Ltd., No. 405; 24 mm width) was attached to the cut surface of the grid, and rubbed with an eraser for complete adhesion. Thereafter, the cellophane adhesive tape is peeled off vertically from the hard coat layer surface of the optical laminated polyester film, the number of squares peeled off from the hard coat layer surface is visually counted, and the hard coat layer and the base film are Adhesion was sought. In addition, what peeled partially among squares was also counted as the square which peeled, and was ranked according to the following references | standards.
Adhesiveness (%) = (1−number of peeled squares / 100) × 100
A: 100%
○: 99-90%
Δ: 90-70%
X: 69 to 0%

(10) Moisture and heat resistance An optical laminated polyester film having a hard coat layer prepared in the examples described later is left in a high-temperature and high-humidity tank at 60 ° C. and 95 RH% for 500 hours, and then at room temperature and normal humidity. Left for hours. And the contact | adhesion adhesiveness of a hard-coat layer and a base film was calculated | required by the method similar to said (9), and it ranked according to the following reference | standard.
A: 100%
○: 99-90%
Δ: 90-70%
X: 69 to 0%

(11) Scratch resistance of coating layer 3 cm (film width direction) × 20 cm of an optically easy-adhesive polyester film produced in an example described later on a friction fastness tester (manufactured by Daiei Kagaku Seisakusho, RT-200). (Film longitudinal direction) attached, using a load head part (2 cm × 2 cm, 200 g) with a weight (300 g) and an aluminum foil (thickness 80 μm, arithmetic average surface roughness 0.03 μm) at the contact part of the sample film, A 10 cm distance was reciprocated 10 times at a speed of 20 seconds per reciprocation. The sample film obtained was placed on a black mount and it was visually confirmed whether the powder had fallen.
A: No powder falling on the black mount.
○: Slight powder falling can be confirmed depending on the location on the black mount.
(Triangle | delta): The slight powder fall can be confirmed on the whole black mount.
X: Powder fall can be clearly confirmed on the black mount.

The arithmetic average surface roughness is a value measured under the following conditions using a non-contact surface shape measurement system (VertScan R550H-M100).
(Measurement condition)
・ Measurement mode: WAVE mode ・ Objective lens: 50 × ・ 0.5 × Tube lens ・ Measurement area 187 × 139 μm

(Production Example 1-Base Material Polyester A)
When the temperature of the esterification reactor was raised to 200 ° C., 86.4 parts by mass of terephthalic acid and 64.6 parts by mass of ethylene glycol were charged and 0.017 parts by mass of antimony trioxide as a catalyst while stirring. 0.064 parts by mass of magnesium acetate tetrahydrate and 0.16 parts by mass of triethylamine were charged. Next, the pressure was raised and the pressure esterification reaction was carried out under the conditions of gauge pressure 0.34 MPa and 240 ° C., then the esterification reaction can was returned to normal pressure, and 0.014 parts by mass of phosphoric acid was added. Furthermore, it heated up to 260 degreeC over 15 minutes, and 0.012 mass part of trimethyl phosphate was added. Then, after 15 minutes, dispersion treatment was performed with a high-pressure disperser, and after 15 minutes, the obtained esterification reaction product was transferred to a polycondensation reaction can and subjected to polycondensation reaction at 280 ° C. under reduced pressure.

  After completion of the polycondensation reaction, it is filtered through a NASRON filter with a 95% cut diameter of 5 μm, extruded into a strand from a nozzle, and cooled and solidified using cooling water that has been filtered (pore diameter: 1 μm or less) in advance. And cut into pellets. The obtained polyethylene terephthalate resin (A) had an intrinsic viscosity of 0.62 dl / g and contained substantially no inert particles and internally precipitated particles. (Hereafter, abbreviated as PET (A).)

(Production Example 2-Polymerization of polyester resin for coating layer)
In a stainless steel autoclave equipped with a stirrer, a thermometer and a partial reflux condenser, 302.9 parts by mass of dimethyl 2,6-naphthalenedicarboxylate, 47.4 parts by mass of dimethyl-5-sodium sulfoisophthalate, ethylene glycol 198 .6 parts by mass, 1,6-hexanediol 118.2 parts by mass, and tetra-n-butyl titanate 0.4 parts by mass were charged and a transesterification reaction was performed from 160 ° C. to 220 ° C. over 4 hours. Furthermore, 121.4 parts by weight of sebacic acid was added to carry out the esterification reaction. Next, the temperature was raised to 255 ° C., and the reaction system was gradually reduced in pressure, and then reacted for 1 hour 30 minutes under a reduced pressure of 30 Pa to obtain a copolymerized polyester resin (X-1). The obtained copolyester resin was light yellow and transparent.

In the same manner, copolymer polyester resins (X-2) to (X-12) having different compositions were obtained. Table 1 shows the results of the composition and weight average molecular weight measured by ¹ H-NMR for these copolyester resins.

(Production Example 3-Preparation of aqueous dispersion of polyester for coating layer)
In a reactor equipped with a stirrer, a thermometer and a reflux device, 20 parts by mass of polyester resin (X-1) and 15 parts by mass of ethylene glycol t-butyl ether were added and heated and stirred at 110 ° C. to dissolve the resin. After the resin was completely dissolved, 65 parts by mass of water was gradually added to the polyester solution while stirring. After the addition, the solution was cooled to room temperature while stirring to prepare an aqueous dispersion (Y-1) of milky white polyester having a solid content of 20% by mass. Similarly, polyester resins (X-2) to (X-12) are used in place of the polyester resin (X-1) to prepare an aqueous dispersion, and the aqueous dispersions (Y-2) to (Y-12) are prepared. ).

(Production Example 4-Preparation of coating solution for coating layer formation)
The following coating agent was mixed and the coating liquid (Z-1) was created. Particle A is SnO ₂ having a refractive index of 2.1, and particle B is silica particles having an average primary particle size of about 500 nm.
Water 40.16% by mass
Isopropanol 30.00% by mass
Polyester aqueous dispersion (Y-1) 18.19 mass%
Block polyisocyanate aqueous dispersion (C) 2.08% by mass
Particle A 9.37 mass%
(Cerames S-8, manufactured by Taki Chemical Co., Ltd., solid content concentration 8% by mass)
Particle B 0.17% by mass
(Nippon Shokubai Co., Ltd. Sea Hoster KEW50, solid content concentration 15 mass%)
Silicon-based surfactant 0.03% by mass
(Solid content 100%)

(Production Example 5-Polymerization of blocked polyisocyanate crosslinking agent)
100 parts by mass of a polyisocyanate compound having an isocyanurate structure using hexamethylene diisocyanate as a raw material (manufactured by Asahi Kasei Chemicals, Duranate TPA) in a flask equipped with a stirrer, a thermometer and a reflux condenser, 55 parts by mass of propylene glycol monomethyl ether acetate, 30 parts by mass of polyethylene glycol monomethyl ether (average molecular weight 750) was charged and held at 70 ° C. for 4 hours in a nitrogen atmosphere. Thereafter, the reaction solution temperature was lowered to 50 ° C., and 47 parts by mass of methyl ethyl ketoxime was added dropwise. The infrared spectrum of the reaction solution was measured to confirm that the absorption of the isocyanate group had disappeared, and a block polyisocyanate aqueous dispersion (C) having a solid content of 75% by mass was obtained.

(Production Example 6-polymerization of oxazoline-based crosslinking agent)
A mixture of 58 parts by mass of ion-exchanged water and 58 parts by mass of isopropanol as an aqueous medium in a flask equipped with a thermometer, a nitrogen gas introduction tube, a reflux condenser, a dropping funnel, and a stirrer, and a polymerization initiator (2, 2 4 parts by mass of '-azobis (2-amidinopropane) dihydrochloride) was added. On the other hand, in a dropping funnel, 16 parts by mass of 2-isopropenyl-2-oxazoline as a polymerizable unsaturated monomer having an oxazoline group, methoxypolyethylene glycol acrylate (average number of moles of ethylene glycol added: 9 moles, Shin Nakamura Chemical) A mixture of 32 parts by mass and 32 parts by mass of methyl methacrylate was added, and the mixture was added dropwise at 70 ° C. for 1 hour in a nitrogen atmosphere. After completion of the dropwise addition, the reaction solution was stirred for 9 hours and cooled to obtain a water-soluble resin (D) having an oxazoline group having a solid concentration of 40% by mass.

(Production Example 7-Polymerization of carbodiimide-based crosslinking agent)
A flask equipped with a stirrer, thermometer and reflux condenser was charged with 168 parts by mass of hexamethylene diisocyanate and 220 parts by mass of polyethylene glycol monomethyl ether (M400, average molecular weight 400), stirred at 120 ° C. for 1 hour, 26 parts by mass of 4′-dicyclohexylmethane diisocyanate and 3.8 parts by mass of 3-methyl-1-phenyl-2-phospholene-1-oxide (2% by weight based on the total isocyanate) were added as a carbodiimidization catalyst, and 185 under a nitrogen stream. Stir at 5 ° C. for a further 5 hours. The infrared spectrum of the reaction solution was measured, and it was confirmed that absorption at a wavelength of 2200 to 2300 cm ⁻¹ disappeared. It stood to cool to 60 degreeC, 567 mass parts of ion-exchange water was added, and the carbodiimide water-soluble resin (E) with a solid content of 40 mass% was obtained.

Example 1
The PET (A) resin pellets containing no particles were dried under reduced pressure (1 Torr) at 135 ° C. for 6 hours, and then supplied to an extruder and dissolved at 285 ° C. It is filtered with a filter material of stainless steel sintered body (nominal filtration accuracy 10μm particle 95% cut), extruded into a sheet form from the die with a single layer block, and then cast at a surface temperature of 30 ° C. using an electrostatic application casting method. It was wound around a drum and solidified by cooling to produce an unstretched film.

Subsequently, the said coating liquid (Z-1) was apply | coated to the single side | surface of this unstretched PET film by the reverse roll method, and it dried at 80 degreeC for 20 second. In addition, it adjusted so that the application quantity after the last (after extending | stretching) drying might be set to 0.15 g / m < ² >.

  The unstretched film on which this coating layer was formed was guided to a tenter stretching machine, and the film was guided to a hot air zone at a temperature of 125 ° C. while being gripped by a clip, and stretched 4.0 times in the width direction. Next, while maintaining the width stretched in the width direction, the film is processed at a temperature of 225 ° C. for 30 seconds, and further subjected to a relaxation treatment of 3% in the width direction, and is a uniaxially oriented polyester film having a film thickness of about 50 μm. An easily adhesive polyester film was obtained. When observed with an electron microscope, the thickness of the coating layer was 120 nm.

The hard coat layer-forming coating solution (C-1) having the following composition was applied to the coating layer surface of the obtained optically easy-adhesive polyester film using a # 10 wire bar, dried at 70 ° C. for 1 minute, Was removed. Next, the film coated with the hard coat layer was irradiated with 300 mJ / cm ² ultraviolet rays using a high-pressure mercury lamp to obtain an optical laminated polyester film having a thickness of 5 μm. The refractive index of the hard coat layer was 1.55. The evaluation results are shown in Table 2.
Hard coat layer forming coating solution (C-1)
Isopropanol 48.47 mass%
Dipentaerythritol hexaacrylate 21.25% by mass
(Shin-Nakamura Chemical A-DPH)
Polyethylene diacrylate 5.67% by mass
(Shin-Nakamura Chemical A-400)
ZrO ₂ sol 23.61% by mass
(Nissan Chemical OZ-30M, solid content 30% by mass)
Photopolymerization initiator 1.00% by mass
(Irgacure 184 manufactured by Ciba Specialty Chemicals)

(Example 2)
By changing the thickness of the unstretched film, an optically easy-adhesive polyester film, which is a uniaxially oriented polyester film, was obtained in the same manner as in Example 1 except that the thickness was about 100 μm. A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics.

(Example 3)
An unstretched film produced by the same method as in Example 1 is heated to 105 ° C. using a heated roll group and an infrared heater, and then stretched 1.5 times in the running direction with a roll group having a difference in peripheral speed. After that, the film was stretched 4.0 times in the width direction in the same manner as in Example 1 to obtain a highly adhesive polyester film for optics which is a biaxially oriented polyester film having a film thickness of about 50 μm. A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics.

Example 4
In the same manner as in Example 3, the film was stretched 2.0 times in the running direction and 4.0 times in the width direction to obtain a highly adhesive polyester film for optics which is a biaxially oriented polyester film having a film thickness of about 50 μm. . A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics.

(Example 5)
In the same manner as in Example 3, the film was stretched 3.3 times in the running direction and 4.0 times in the width direction to obtain an optically easily adhesive polyester film which is a biaxially oriented polyester film having a film thickness of about 75 μm. . A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics.

(Example 6)
100 parts by weight of a photopolymerization initiator-containing acrylic resin (Daiichi Seika Kogyo Co., Ltd., Seika Beam EXF-01J), copolymer polyester resin (Toyobo Co., Ltd., Byron 200, weight average molecular weight: 18,000 ) Blended at 0.20 parts by weight, a mixed solvent of toluene / MEK (8/2; weight ratio) as a solvent was added so that the solid concentration would be 50% by weight, and the mixture was stirred and dissolved uniformly. Was prepared. Using the Meyer bar, the coating solution prepared above was applied to the surface opposite to the surface on which the hard coat layer of the optically laminated polyester film obtained in Example 1 was laminated so that the thickness of the coating film was 5 μm. And then dried at 80 ° C. for 1 minute, and then irradiated with ultraviolet rays (light quantity: 300 mJ / cm ² ) using an ultraviolet irradiation device (UB042-5AM-W type manufactured by Eye Graphics Co., Ltd.) The coating was cured.
Next, a transparent conductive thin film made of indium-tin composite oxide was formed on the cured product layer. At this time, 2.0 W / cm ² of DC power was applied to the target using indium oxide containing 10% by weight of tin oxide as a target (Mitsui Metal Mining Co., Ltd., density: 7.1 g / cm ³ ). did. Further, Ar gas was flowed at 130 sccm and O ₂ gas was flowed at a flow rate of 10 sccm, and a film was formed by DC magnetron sputtering in an atmosphere of 0.40 Pa. However, in order to prevent arc discharge instead of normal DC, a +20 V pulse having a width of 5 μs was applied at a cycle of 50 kHz. Moreover, it sputter | spatterred, cooling a film with a -10 degreeC cooling roll. In addition, while constantly monitoring the oxygen partial pressure of the atmosphere with a sputter process monitor (Hakuto Co., Ltd., SPM200), an oxygen gas flow meter and an oxygen gas flow meter so that the degree of oxidation in the indium-tin composite oxide thin film becomes constant I went back to DC power. As described above, a transparent conductive thin film made of an indium-tin composite oxide having a thickness of 27 nm was deposited.
Further, this transparent conductive film is used as one panel plate, and the other panel plate is formed of an indium-thin oxide composite oxide thin film (tin oxide content: 10% by weight) having a thickness of 20 nm by plasma CVD on a glass substrate. A transparent conductive thin film was used. The two panel plates were arranged through epoxy beads having a diameter of 30 μm so that the transparent conductive thin film faced to prepare a touch panel.

(Example 7)
In the same manner as in Example 3, the film was stretched 4.0 times in the running direction and 1.0 times in the width direction to obtain an easily adhesive polyester film for optics which is a uniaxially oriented polyester film having a film thickness of about 100 μm. A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics. The obtained film had Re of 3000 nm or more and good visibility, but the mechanical strength was slightly inferior.

(Example 8)
In the same manner as in Example 3, the film was stretched 3.5 times in the running direction and 3.7 times in the width direction to obtain an easily adhesive polyester film for optics which is a biaxially oriented polyester film having a film thickness of about 250 μm. . A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics. The obtained film had Re of 4500 nm or more, but the Re / Rth ratio was less than 0.2. Therefore, an extremely thin rainbow was observed in an oblique direction.

Example 9
In the same manner as in Example 1, the film was stretched 1.0 times in the running direction and 3.5 times in the width direction to obtain an easily adhesive polyester film for optics which is a uniaxially oriented polyester film having a film thickness of about 75 μm. A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics.

(Example 10)
Using the same method as in Example 1, the thickness of the unstretched film was changed to obtain a uniaxially oriented polyester film having a thickness of about 275 μm. A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics.

(Comparative Example 1)
In the same manner as in Example 3, the film was stretched 3.6 times in the running direction and 4.0 times in the width direction to obtain an optically easily adhesive polyester film that is a biaxially oriented polyester film having a film thickness of about 38 μm. . A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics. The obtained film had low retardation, and rainbow-like color spots were observed when observed from an oblique direction.

(Comparative Example 2)
By using the same method as in Example 1 and changing the thickness of the unstretched film, an easily adhesive polyester film for optics which is a uniaxially oriented polyester film having a thickness of about 10 μm was obtained. A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics. The obtained film was very easy to tear and had no stiffness, so it could not be used as an optical film. Moreover, the retardation was low and iridescent colored spots were observed.

(Comparative Example 3)
The same procedure as in Example 1 was performed except that rainbow spots were observed using a cold cathode tube as the light source of the liquid crystal display device.

(Comparative Example 4)
An easily adhesive polyester film for optics was obtained in the same manner as in Example 1 except that the polyester aqueous dispersion was changed to Y-10. A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics.

(Comparative Example 5)
An optically easy-adhesive polyester film was obtained in the same manner as in Example 1 except that the particle A was changed to SiO ₂ having a refractive index of 1.46 (Snowtex ZL manufactured by Nissan Chemical Industries, solid content concentration 40% by mass). A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics.

(Comparative Example 6)
An optically easy-adhesive polyester film was obtained in the same manner as in Example 1 except that the particles B were excluded. A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics.

(Comparative Example 7)
An optical laminated polyester film was obtained in the same manner as in Example 1, except that the particle B was changed and the hard coat layer forming coating solution (C-1) was changed to the following (C-2). The refractive index of the hard coat layer was 1.55.
Hard coat layer forming coating solution (C-2)
Methyl ethyl ketone 39.00% by mass
Toluene 9.47% by mass
Dipentaerythritol hexaacrylate 21.25% by mass
(Shin-Nakamura Chemical A-DPH)
Polyethylene diacrylate 5.67% by mass
(Shin-Nakamura Chemical A-400)
SnO ₂ sol 23.61% by mass
(FSS-10T manufactured by Ishihara Sangyo Co., Ltd., solid content concentration 30% by mass)
Photopolymerization initiator 1.00% by mass
(Irgacure 184 manufactured by Ciba Specialty Chemicals)

(Comparative Example 8)
An optically easy-adhesive polyester film was obtained in the same manner as in Example 1 except that the particles B were changed to silica particles having an average particle diameter of 100 nm (Snowtex ZL manufactured by Nissan Chemical Industries, solid content concentration 40% by mass). A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics.

(Comparative Example 9)
An easily adhesive polyester film for optics was obtained in the same manner as in Example 1 except that the polyester aqueous dispersion was changed to Y-11. A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics.

(Comparative Example 10)
An easily adhesive polyester film for optics was obtained in the same manner as in Example 1 except that the polyester aqueous dispersion was changed to Y-12. A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics.

(Example 11)
An easily adhesive polyester film for optics was obtained in the same manner as in Example 1 except that the coating solution (Z-1) was changed to the following. A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics.
(Coating solution Z-1)
44.54% by mass of water
Isopropanol 30.00% by mass
Polyester aqueous dispersion (Y-1) 12.21% by mass
Block polyisocyanate aqueous dispersion (C) 3.67% by mass
Particle A 9.38 mass%
(Cerames S-8, manufactured by Taki Chemical Co., Ltd., solid content concentration 8% by mass)
Particle B 0.17% by mass
(Nippon Shokubai Co., Ltd. Sea Hoster KEW50, solid content concentration 15 mass%)
Silicon-based surfactant 0.03% by mass
(Solid concentration 100% by mass)

(Example 12)
An easily adhesive polyester film for optics was obtained in the same manner as in Example 1 except that the coating solution (Z-1) was changed to the following. A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics.
Water 37.29% by mass
Isopropanol 30.00% by mass
Polyester water dispersion (Y-1) 22.09 mass%
Block polyisocyanate aqueous dispersion (C) 1.04% by mass
Particle A 9.38 mass%
(Cerames S-8, manufactured by Taki Chemical Co., Ltd., solid content concentration 8% by mass)
Particle B 0.17% by mass
(Nippon Shokubai Co., Ltd. Sea Hoster KEW50, solid content concentration 15 mass%)
Silicon-based surfactant 0.03% by mass
(Solid concentration 100% by mass)

(Example 13)
An easily adhesive polyester film for optics was obtained in the same manner as in Example 1 except that the coating solution (Z-1) was changed to the following. A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics.
35.76% by weight of water
Isopropanol 30.00% by mass
Polyester aqueous dispersion (Y-1) 24.17% by mass
Block polyisocyanate aqueous dispersion (C) 0.49% by mass
Particle A 9.38 mass%
(Cerames S-8, manufactured by Taki Chemical Co., Ltd., solid content concentration 8% by mass)
Particle B 0.17% by mass
(Nippon Shokubai Co., Ltd. Sea Hoster KEW50, solid content concentration 15 mass%)
Silicon-based surfactant 0.03% by mass
(Solid concentration 100% by mass)

(Example 14)
An optically easy-adhesive polyester film was obtained in the same manner as in Example 1 except that the particles B were changed to silica particles having an average particle size of 230 nm (Quartron PL-20 manufactured by Fuso Chemical Industry Co., Ltd., solid content concentration: 24% by mass). A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics.

(Example 15)
An optically easy-adhesive polyester film was obtained in the same manner as in Example 1 except that the particles B were changed to acrylic particles having an average particle diameter of 300 nm (Gantz Kasei's Gantz Pearl PM-030, solid content concentration of 41% by mass). A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics.

(Example 16)
An optically easily adhesive polyester film was obtained in the same manner as in Example 1 except that the particle B was changed to silica particles having an average particle diameter of 450 nm (MP4540M, Nissan Chemical Industries, Ltd., solid content concentration: 40% by mass). A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics.

(Example 17)
An optically easily adhesive polyester film was obtained in the same manner as in Example 1 except that the particles B were changed to crosslinked polystyrene particles having an average particle diameter of 700 nm (Glossdale 207-S, manufactured by Mitsui Chemicals, solid content concentration: 53 mass%). . A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics.

(Example 18)
Particle A is ZrO ₂ having a refractive index of 2.4 (ZR-40BL manufactured by Nissan Chemical Industries, solid concentration 40% by mass), and particle B is silica particles having an average particle size of 230 nm (Quartron PL-20 manufactured by Fuso Chemical Industries, solid content) An optically easily adhesive polyester film was obtained in the same manner as in Example 1 except that the concentration was changed to 24% by mass. A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics.

(Example 19)
Particle A is ZrO ₂ having a refractive index of 2.4 (ZR-40BL manufactured by Nissan Chemical Industries, solid concentration 40% by mass), Particle B is an acrylic particle having an average particle size of 300 nm (Gantz Kasei Gantz Pearl PM-030, solid content) A highly adhesive polyester film for optics was obtained in the same manner as in Example 1 except that the concentration was changed to 41% by mass. A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics.

(Example 20)
ZrO ₂ with a refractive index of 2.4 (ZR-40BL manufactured by Nissan Chemical Industries, solid content concentration 40% by mass) and silica particles with an average particle diameter of 450 nm (MP4540M manufactured by Nissan Chemical Industries, solid content concentration 40 masses) %), An optically easy-adhesive polyester film was obtained in the same manner as in Example 1. A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics.

(Example 21)
An optically easily adhesive polyester film was obtained in the same manner as in Example 1 except that the particle A was changed to ZrO ₂ having a refractive index of 2.4 (ZR-40BL manufactured by Nissan Chemical Industries, solid concentration 40% by mass). A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics.

(Example 22)
Particle A is ZrO ₂ having a refractive index of 2.4 (ZR-40BL manufactured by Nissan Chemical Industries, solid concentration 40% by mass), and particle B is a crosslinked polystyrene particle having an average particle size of 700 nm (Grossdale 207-S manufactured by Mitsui Chemicals, solid An easily adhesive polyester film for optics was obtained in the same manner as in Example 1 except that the partial concentration was changed to 53% by mass. A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics.

(Example 23)
Particle A is TiO ₂ having a refractive index of 2.7 (TTO-W-5 manufactured by Ishihara Sangyo Co., Ltd., solid content concentration: 30% by mass), and particle B is silica particles having an average particle size of 230 nm (Quartron PL-20 manufactured by Fuso Chemical Industry Co., Ltd.) An easily adhesive polyester film for optics was obtained in the same manner as in Example 1 except that the concentration was changed to 24% by mass. A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics.

(Example 24)
Particle A is TiO ₂ having a refractive index of 2.7 (TTO-W-5, manufactured by Ishihara Sangyo Co., Ltd., solid content concentration 30% by mass), particle B is an acrylic particle having an average particle size of 300 nm (Ganz Pearl PM-030 manufactured by Ganz Kasei), solid An optically easy-adhesive polyester film was obtained in the same manner as in Example 1 except that the partial concentration was changed to 41% by mass. A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics.

(Example 25)
Particle A is TiO ₂ having a refractive index of 2.7 (TTO-W-5 manufactured by Ishihara Sangyo Co., Ltd., solid content concentration: 30% by mass), and particle B is silica particles having an average particle size of 450 nm (MP4540M manufactured by Nissan Chemical Industries, solid content concentration of 40). An optically easily adhesive polyester film was obtained in the same manner as in Example 1 except that the mass was changed to (% by mass). A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics.

(Example 26)
An optically easily adhesive polyester film was obtained in the same manner as in Example 1 except that the particle A was changed to TiO ₂ having a refractive index of 2.7 (Ishihara Sangyo TTO-W-5, solid content concentration of 30% by mass). . A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics.

(Example 27)
Particle A is TiO ₂ having a refractive index of 2.7 (TTO-W-5 manufactured by Ishihara Sangyo Co., Ltd., solid content concentration 30% by mass), and particle B is a crosslinked polystyrene particle having an average particle size of 700 nm (Glossdale 207-S manufactured by Mitsui Chemicals). An easily adhesive polyester film for optics was obtained in the same manner as in Example 1 except that the solid content concentration was changed to 53% by mass. A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics.

(Example 28)
Optically easy-adhesive polyester film and optically laminated polyester film in the same manner as in Example 1 except that the hard coat layer forming coating solution (C-1) was changed to the hard coat layer forming coating solution (C-2). Got.

(Example 29)
An optically easily adhesive polyester film was obtained in the same manner as in Example 1 except that the block polyisocyanate aqueous dispersion (C) was changed to a water-soluble resin (D) having an oxazoline group. A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics.

(Example 30)
An optically easily adhesive polyester film was obtained in the same manner as in Example 1 except that the block polyisocyanate aqueous dispersion (C) was changed to the carbodiimide water-soluble resin (E). A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics.

(Example 31)
An optically easy-adhesive polyester film was obtained in the same manner as in Example 1 except that the block polyisocyanate aqueous dispersion (C) was changed to a melamine resin (Dai Nippon Ink Becamine M-3, solid concentration 60 mass%). It was. A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics.

(Example 32)
An optically easy-adhesive film polyester was obtained in the same manner as in Example 1 except that the polyester aqueous dispersion was changed to Y-2. A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics.

(Example 33)
An easily adhesive polyester film for optics was obtained in the same manner as in Example 1 except that the polyester aqueous dispersion was changed to Y-3. A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics.

(Example 34)
An easily adhesive polyester film for optics was obtained in the same manner as in Example 1 except that the polyester aqueous dispersion was changed to Y-4. A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics.

(Example 35)
An easily adhesive polyester film for optics was obtained in the same manner as in Example 1 except that the polyester aqueous dispersion was changed to Y-5. A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics.

(Example 36)
An easily adhesive polyester film for optics was obtained in the same manner as in Example 1 except that the polyester aqueous dispersion was changed to Y-6. A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics.

(Example 37)
An optically easily adhesive polyester film was obtained in the same manner as in Example 1 except that the polyester aqueous dispersion was changed to Y-7. A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics.

(Example 38)
An easily adhesive polyester film for optics was obtained in the same manner as in Example 1 except that the polyester aqueous dispersion was changed to Y-8. A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics.

(Example 39)
An easily adhesive polyester film for optics was obtained in the same manner as in Example 1 except that the polyester aqueous dispersion was changed to Y-9. A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics.

(Example 40)
An easily adhesive polyester film for optics was obtained in the same manner as in Example 1 except that the coating solution (Z-1) was changed to the following. A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics.
Water 40.16% by mass
Isopropanol 30.00% by mass
Polyester water dispersion (Y-1) 24.27 mass%
Block polyisocyanate aqueous dispersion (C) 2.78% by mass
Particle A 2.59 mass%
(Ishihara Sangyo TTO-W-5, solid concentration 30% by mass)
Particle B 0.17% by mass
(Nippon Shokubai Co., Ltd. Sea Hoster KEW50, solid content concentration 15 mass%)
Silicon-based surfactant 0.03% by mass
(Solid concentration 100% by mass)

(Example 41)
An easily adhesive polyester film for optics was obtained in the same manner as in Example 1 except that the coating solution (Z-1) was changed to the following. A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics.
Water 40.16% by mass
Isopropanol 30.00% by mass
Polyester aqueous dispersion (Y-1) 24.97% by mass
Block polyisocyanate aqueous dispersion (C) 2.86% by mass
Particle A 1.81% by mass
(Ishihara Sangyo TTO-W-5, solid concentration 30% by mass)
Particle B 0.17% by mass
(Nippon Shokubai Co., Ltd. Sea Hoster KEW50, solid content concentration 15 mass%)
Silicon-based surfactant 0.03% by mass
(Solid concentration 100% by mass)

(Example 42)
An easily adhesive polyester film for optics was obtained in the same manner as in Example 1 except that the coating solution (Z-1) was changed to the following. A hard coat layer was provided in the same manner as in Example 1 on the resulting optically easy-adhesive polyester film to obtain a laminated polyester film for optics.
Water 40.16% by mass
Isopropanol 30.00% by mass
Polyester aqueous dispersion (Y-1) 25.91% by mass
Block polyisocyanate aqueous dispersion (C) 2.96 mass%
Particle A 0.77% by mass
(Ishihara Sangyo TTO-W-5, solid concentration 30% by mass)
Particle B 0.17% by mass
(Nippon Shokubai Co., Ltd. Sea Hoster KEW50, solid content concentration 15 mass%)
Silicon-based surfactant 0.03% by mass
(Solid concentration 100% by mass)

  The results measured for the above Examples and Comparative Examples are shown in Tables 2 and 3 below.

The optically easy-adhesive polyester film of the present invention has good processability, and prevents reflection of external light, glare, iris color, etc. when a hard coat layer is laminated on the coating layer of the film. In addition to excellent adhesion and excellent adhesion to the hard coat layer and adhesion under high temperature and high humidity (moisture and heat resistance), visibility caused by the optical anisotropy (retardation) of the polyester film when observed through sunglasses Because it is also good, it can be attached to the front of display screens and icon sheets such as touch panels, liquid crystal displays (LCDs), television and computer cathode ray tubes (CRTs), plasma displays (PDPs), and organic electroluminescence (organic ELs). An anti-reflection film that provides anti-reflection properties that suppress light reflections, glare, iris colors, etc. It is suitable as a base film of the beam. Moreover, it can also be used as a film for preventing touch panel scattering.

Claims (9)

An easily adhesive polyester film for optics having a coating layer containing a polyester resin, particles A and particles B on at least one side of a polyester film having a retardation of 3000 to 30000 nm,
The polyester resin includes naphthalenedicarboxylic acid as an acid component, a dicarboxylic acid component represented by the following formula (1) and / or a diol component represented by the following formula (2),
The particle A is a metal oxide particle having a refractive index of 1.7 or more and 3.0 or less,
An easily adhesive polyester film for optics, wherein the particle B is a particle having an average particle size of 200 nm to 700 nm.
(1) HOOC- (CH ₂ ) n —COOH (where n is an integer of 4 ≦ n ≦ 10)
(2) HO— (CH ₂ ) n —OH (where n is an integer of 4 ≦ n ≦ 10) The easily adhesive polyester film for optics according to claim 1 whose ratio (Re / Rth) of retardation of a polyester film and thickness direction retardation is 0.2 or more.   The easily adhesive polyester film for optics according to claim 1 or 2, wherein the coating layer contains a crosslinking agent.   The crosslinking agent is at least one crosslinking agent selected from the group consisting of urea crosslinking agents, epoxy crosslinking agents, melamine crosslinking agents, isocyanate crosslinking agents, oxazoline crosslinking agents, and carbodiimide crosslinking agents. The easily adhesive polyester film for optics according to claim 3 characterized by the above-mentioned.   The optical layer formed by laminating a hard coat layer made of an electron beam, an ultraviolet curable acrylic resin, or a siloxane-based thermosetting resin on the coating layer of the optically easy-adhesive polyester film according to claim 1. Laminated polyester film. The transparent conductive film which has a transparent conductive thin film in the side which has the said application layer of the easily adhesive polyester film for optics in any one of Claims 1-4, or its opposite side. The transparent conductive film which has a transparent conductive thin film in the side which laminated | stacked the hard-coat layer of the laminated polyester film for optics of Claim 5, or the other side. A capacitive or resistive touch panel using the transparent conductive film according to claim 6 or 7. A liquid crystal display device comprising at least a touch panel according to claim 8 and a white light emitting diode as a backlight light source.