TW202248320A - Readily adhesive polyester film - Google Patents

Abstract

To provide a readily adhesive polyester film which improves the reliability of the adhesion thereof to a functional layer such as a hardcoat layer, and to further provide a readily adhesive polyester film which is favorable for optical use. A readily adhesive polyester film, at least one surface of which has a coating layer obtained by curing a composition containing a polyester having a polycyclic aromatic skeleton, and a crosslinking agent having one or more skeletons which are selected from among aliphatic, alicyclic and heterocyclic skeletons, wherein the values of properties pertaining to the thickness of the formed coating layer, the surface free energy of the coating layer surface of the coating layer which does not contact the polyester film, the nitrogen atom ratio on the coating layer surface and the nitrogen atom ratio in the depth direction of the coating layer satisfy a specific relationship.

Description

Easy Adhesive Polyester Film

The present invention relates to an easily-adhesive polyester film excellent in adhesion to various functional layers, anti-blocking property, and transparency. More specifically, it relates to an easily-adhesive polyester film that can also be suitably used for optical applications.

A hard coat film laminated with a transparent hard coat layer can be used on the front surface of displays such as touch panels, computers, televisions, liquid crystal display devices, and decorative materials. In addition, as the transparent plastic film of the base material, a transparent polyester film can generally be used. In order to improve the adhesion between the polyester film of the base material and the hard coat layer, a coating with easy adhesion is usually provided on the surface of the polyester film. Layer acts as an intermediate layer among them.

The aforementioned hard coat film requires durability against temperature, humidity, light, transparency, chemical resistance, scratch resistance, stain resistance, and the like. In addition, since it is often used on the surface of displays and decorative materials, visibility and design are required. Therefore, since unevenness and rainbow-like colors caused by reflected light can be suppressed when viewed from any angle, the upper layer of the hard coat layer is generally provided with a high refractive index layer and a low refractive index layer. Anti-reflective layer of multi-layer structure.

In recent years, hard coatings with various skeletons have been developed, and the adhesion between the substrate and the hard coating was discussed at that time. In addition to the initial adhesion immediately after lamination, the reliability of liquid crystal displays using hard-coated films for long-term use requires moisture and heat resistance, adhesion retention, and adhesion degradation over time. , products with various evaluation tolerances are required.

In the field of known easy-adhesive polyester films, it has been proposed that when a polyester resin containing a naphthalene dicarboxylic acid component is used in an easily-adhesive coating layer, the adhesiveness to the base polyester film is also excellent. A preferred example (for example, refer to Patent Document 1). Moreover, the method of using the polyurethane resin which has a polycarbonate component as resin excellent in flexibility and high in adhesiveness is proposed (for example, refer patent document 2). However, although the adhesiveness was confirmed in all, the easy-adhesive polyester film which guaranteed the adhesiveness after long-term storage could not be obtained. [Prior Art Literature] [Patent Document]

[Patent Document 1] Japanese Unexamined Patent Publication No. 2011-246663 [Patent Document 2] Japanese Unexamined Patent Publication No. 2011-168053

[Problem to be solved by the invention]

The present invention has been accomplished against the background of the problems of the prior art. That is, the object of the present invention is to provide an easily adhesive polyester film with improved reliability of adhesion with functional layers such as hard coats, and to provide an easily adhesive polyester film suitable for use in optical applications, etc. . [Means to solve the problem]

The present invention has been accomplished as a result of careful examination to achieve the object. That is, the present invention includes the following configurations. 1. An easily-adhesive polyester film, which is an easily-adhesive polyester film having a coating layer formed by hardening a composition on at least one side of the polyester film, and the composition contains a polycyclic aromatic skeleton. ester, and a crosslinking agent having at least one skeleton selected from aliphatic, alicyclic, and heterocyclic groups, wherein the thickness (d: nm) of the coating layer satisfies the following formula (1), and the coating layer The surface free energy (γ _s : mN/m) of the surface of the coating layer that is not in contact with the polyester film satisfies the following formula (2), and the nitrogen atomic ratio of the coating layer surface obtained according to X-ray photoelectron spectroscopy (ESCA) (A _N : at%) satisfies the following formula (3), in the nitrogen element distribution curve measured from the element distribution in the depth direction, relative to the time t when the ratio of nitrogen atoms becomes the lower limit value (A _N Y : at%) ₁ (second), the ratio of the time t ₂ (second) at which the ratio of nitrogen atoms becomes the maximum value (A _N X: at%) to the median value of the A _N Y (A _N Z: at%) (t ₂ / t ₁ ) satisfies the following formula (4), 30 ≦ d ≦ 200 ... formula (1) 43 ≦ γ _s ≦ 49 ... formula (2) 3.0 ≦ A _N ≦ 9.5 ... formula (3) (t ₂ /t ₁ ) × 100 ≧ 40 ...Formula (4). 2. The easy-adhesive polyester film according to point 1, wherein the adhesion X (%) when a hard coat layer is provided on the coating layer after film formation is 95% or more, and the adhesion X is the same as that at 80°C , Adhesiveness Y(%) when a hard coat layer is placed on the coating layer after being left for 24 hours in a 90%RH environment satisfies the following formula (5), XY(%) ≦ 5 ... formula (5). 3. The easily-adhesive polyester film according to point 1. or point 2., wherein the polyester having a polycyclic aromatic skeleton is a polyester having a naphthalene skeleton. 4. The easily-adhesive polyester film according to any one of points 1 to 3, wherein the crosslinking agent having at least one skeleton selected from aliphatic, alicyclic, and heterocyclic groups is An isocyanate crosslinking agent having at least one skeleton selected from aliphatic, alicyclic, and heterocyclic. [Effect of Invention]

According to the present invention, it is possible to provide an easily-adhesive polyester film with guaranteed adhesion and reliability after long-term storage with a functional layer such as a hard coat layer, and its application to optical applications and the like can be broadened.

[Mode for Carrying Out the Invention]

(Polyester film) In the present invention, the polyester film used as the substrate is a film mainly composed of polyester resin. Here, the "film mainly composed of polyester resin" means a film formed of a resin composition containing 50% by mass or more of polyester resin. When blending with other polymers (for example, polycarbonate resin, polyimide resin, etc.), it means to contain more than 50% by mass of polyester resin, and when it is copolymerized with other monomers, it means to contain 50% by weight. More than 10% of polyester structural units. The polyester film preferably contains 90% by mass or more of the polyester resin, more preferably 95% by mass or more, still more preferably 100% by mass.

The material of the polyester resin is not particularly limited, and a copolymer formed by polycondensation of a dicarboxylic acid component and a diol component, or a blend resin thereof can be used. Examples of dicarboxylic acid components include terephthalic acid, isophthalic acid, phthalic acid, 2,5-naphthalene dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, 1,4-naphthalene dicarboxylic acid, 1 ,5-Naphthalene dicarboxylic acid, diphenyl carboxylic acid, diphenoxyethane dicarboxylic acid, diphenylene carboxylic acid, anthracene dicarboxylic acid, 1,3-cyclopentane dicarboxylic acid, 1,3-cyclohexane dicarboxylic acid , 1,4-cyclohexanedicarboxylic acid, hexahydroterephthalic acid, hexahydroisophthalic acid, malonic acid, dimethylmalonic acid, succinic acid, 3,3-diethylsuccinic acid, pentamethylene Diacid, 2,2-dimethylglutaric acid, adipic acid, 2-methyladipic acid, trimethyladipic acid, pimelic acid, azelaic acid, dimer acid, sebacic acid, octane Diacid, dodecyl dicarboxylic acid, etc.

Examples of the glycol component constituting the polyester resin include ethylene glycol, propylene glycol, hexanediol, neopentyl glycol, 1,2-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, decane Diol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 2,2-bis(4-hydroxyphenyl)propane, bis(4 -Hydroxyphenyl) Oxide.

The dicarboxylic acid component and diol component which comprise a polyester resin can be used individually by 1 type or 2 or more types. Moreover, other acid components, such as 1,2,4-benzenetricarboxylic acid, and other hydroxyl components, such as trimethylolpropane, can also be added suitably.

As the polyester resin, specifically, polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, etc., such as Among them, polyethylene terephthalate is preferable from the viewpoint of the balance between physical properties and cost. In addition, in order to control optical properties such as polarization, it is also preferable to contain other copolymer components and other polymers. From the viewpoint of controlling the optical properties of the polyester film, diethylene glycol, a copolymerization component having norbornene in a side chain, and the like are exemplified as preferable copolymerization components.

In order to improve the smoothness, windability, etc. of the polyester film, there may be cases where inactive particles are contained in the film, but in order to maintain high transparency, it is preferable to contain inactive particles in the film. The less content the better. Therefore, it is preferable to have a multilayer structure in which particles are contained only in the surface layer of the film, or to contain particles substantially not in the film and to contain particles only in a coating layer laminated on at least one side of the polyester film.

In addition, "substantially not containing particles" means that, for example, in the case of inorganic particles, the content is 50 ppm or less, preferably 10 ppm, when the elements derived from the particles are quantitatively analyzed by fluorescent X-ray analysis. Below, preferably below the detection limit. In this case, even if the particles are not actively added to the base film, the contamination components derived from foreign matter, the raw material resin, or the contaminants attached to the production line and equipment during the film manufacturing process will be peeled off, making it impossible to Avoidance of mixing into the film is caused by the situation.

Also, when the polyester film is made into a multi-layer structure, the inner layer does not contain inactive particles substantially, and only the outermost layer contains inactive particles. The two-type three-layer structure can have both transparency and processability, so it is better. .

The polyester film used as the base material may be a single layer, or may be laminated with two or more layers. Moreover, various additives can be contained in a film as needed within the range which achieves the effect of this invention. Examples of additives include antioxidants, light stabilizers, antigelling agents, organic wetting agents, antistatic agents, ultraviolet absorbers, surfactants, and the like. Also in the case where the thin film has a laminated structure, it is preferable to contain additives according to the function of each layer as needed. For example, in order to prevent the light deterioration of the polarizer, it is also a preferable aspect to add an ultraviolet absorber or the like to the inner layer.

The polyester film can be produced according to a conventional method. For example, it can be obtained by melting and extruding the above-mentioned polyester resin into a film form, cooling and solidifying it with a casting drum, and forming a film. As the polyester film in the present invention, either an unstretched film or a stretched film can be used, and a stretched film is preferable from the viewpoint of mechanical strength and durability of chemical resistance. When the polyester film is a stretched film, the stretching method is not particularly limited, and longitudinal uniaxial stretching, transverse uniaxial stretching, longitudinal/transverse sequential biaxial stretching, longitudinal/transverse simultaneous biaxial stretching, and the like can be used. When stretching the polyester film, the stretching may be performed before laminating the easily-adhesive coating layer described later, or after laminating the easily-adhesive coating layer. It is also possible to perform uniaxial stretching in the longitudinal or transverse direction before laminating the easily-adhesive coating layer, and to stretch in other directions after laminating the covering layer.

(coating layer) The easily-adhesive polyester film of the present invention is one in which an easily-adhesive coating layer is laminated on the above-mentioned polyester base film. The coating layer contains binding resin and additives.

Hereinafter, each composition of the coating layer will be described in detail. As the binder resin constituting the coating layer, it is a resin with easy adhesiveness. From the viewpoint of particle retention and adhesion, it is preferably polyester. In addition, in the present invention, polyester with a polycyclic aromatic skeleton is most preferable. . This system also has compatibility with the composition of the hard coat layer described later, and when the composition of the hard coat layer has an aromatic skeleton, it is also preferable from the viewpoint of conjugate interaction.

Specific examples of the polyester having a polycyclic aromatic skeleton include polyesters having a naphthalene skeleton, polyesters having a fennel skeleton, polyesters having an anthracene skeleton, and polyesters having a phenanthrene skeleton.

In the present invention, the binder resin constituting the coating layer preferably does not contain polyurethane resin. Urethane resin is used from the viewpoint of the elasticity and formability of the coating film, but it is known that the urea compound is mixed into the polyurethane resin in the form of impurities. If the amount of the compound is too large, it is preferable not to contain a polyurethane resin from the viewpoint of maintaining the temporal stability of the adhesiveness.

The aforementioned polyester is preferably contained in an amount of not less than 10% by mass and not more than 90% by mass based on the solid content of all the resins and crosslinking agents contained in the coating layer forming composition. More preferably, it is 15 mass % or more and 85 mass % or less. When the polyester resin content is 90% by mass or less, the adhesiveness of the functional layer such as a hard coat under high temperature and high humidity can be maintained, which is preferable. Conversely, when the content is 10% by mass or more, the adhesion to the polyester base film can be easily maintained at normal temperature and high temperature and high humidity, which is preferable.

In the present invention, in order to form a crosslinked structure in the coating layer, it is preferable to contain a crosslinking agent. Among them, the crosslinking agent is preferably a crosslinking agent having at least one skeleton selected from aliphatic, alicyclic, and heterocyclic. Also, a crosslinking agent capable of forming urea groups through a side reaction of crosslinking is suitable, and specific examples of the crosslinking agent include isocyanate crosslinking agents and carbodiimide crosslinking agents. Among them, an isocyanate crosslinking agent is preferred from the viewpoint of the temporal stability of the coating liquid and the adhesiveness improvement effect under high-temperature, high-humidity treatment. Furthermore, in the present invention, an isocyanate having at least one skeleton selected from aliphatic, alicyclic, and heterocyclic is most preferable. Moreover, in order to promote a crosslinking reaction, a catalyst etc. can be used suitably in the composition for coating layer formation as needed.

Specific examples of aliphatic isocyanates include 1,4-diisocyanatobutane, 1,5-pentamethylene diisocyanate, 2-methyl-1,5-pentamethylene diisocyanate, 1,6-hexamethylene diisocyanate, 1,12-dodecane diisocyanate, 2,2,4-trimethyl-1,6-hexamethylene diisocyanate, 2,4,4-trimethyl Base-1,6-hexamethylene diisocyanate, 3,5,5-trimethyl-1,6-hexamethylene diisocyanate, etc.

Specific examples of alicyclic isocyanates include cyclohexane diisocyanate, isophorone diisocyanate, 4,4-dicyclohexylmethane diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, 1,4-bis(isocyanatomethyl)cyclohexane, 1,4-diisocyanatocyclohexyl, 1,1-bis(isocyanatomethyl)cyclohexane, 2,4-hexahydrotoluene Diisocyanate, 2,6-hexahydrotoluene diisocyanate, etc.

環之2,4,6-三側氧六氫-1,3,5-三

-1,3,5-三基三(6,1-已二基)三-異氰酸酯、1,3,5-三[(5-異氰酸基-1,3,3-三甲基環己基)甲基]-1,3,5-三

-2,4,6(1H,3H,5H)-三酮等。Specific examples of heterocyclic isocyanates include 2,5-diisocyanatothiophene, 2,5-bis(isocyanatomethyl)thiophene, and 2,5-diisocyanatotetrahydrothiophene , 2,5-bis(isocyanatomethyl)tetrahydrothiophene, 3,4-bis(isocyanatomethyl)tetrahydrothiophene, 2,5-diisocyanato-1,4-di Thiane, 2,5-bis(isocyanatomethyl)-1,4-dithiane, 4,5-diisocyanato-1,3-dithiolane, 4,5- Bis(isocyanatomethyl)-1,3-dithiolane, 4,5-bis(isocyanatomethyl)-2-methyl-1,3-dithiolane , 2,6-bis(isocyanate methyl)furan, 5,5'-methylene bisfurfuryl isocyanate, 5,5'-isopropylidene bisfurfuryl isocyanate, or trimers belonging to diisocyanates Known as trimeric isocyanate body with three

2,4,6-tri-side oxygen hexahydro-1,3,5-tri

-1,3,5-triyltris(6,1-hexanediyl)tri-isocyanate, 1,3,5-tris[(5-isocyanato-1,3,3-trimethylcyclohexyl )methyl]-1,3,5-tri

-2,4,6(1H,3H,5H)-trione etc.

In the present invention, the isocyanate having an aromatic skeleton is likely to react with moisture in the air due to its high reactivity, which will promote the generation of urea compound more than necessary, so it is preferable not to use it in the coating layer forming composition. contain. Furthermore, from the viewpoint of weather resistance, isocyanates having at least one skeleton of aliphatic, alicyclic, or heterocyclic are also preferable. Also in this case, blocked isocyanate can also be used in the same way, and it is especially preferable from the viewpoint of suppressing the generation of urea compounds when the coating agent is an aqueous system.

Examples of blocking agents include bisulfite-based compounds such as sodium bisulfite, 3,5-dimethylpyrazole, 3-methylpyrazole, 4-bromo-3,5-dimethyl Pyrazole-based compounds such as pyrazole and 4-nitro-3,5-dimethylpyrazole, phenol-based compounds such as phenol and cresol, aliphatic alcohol-based compounds such as methanol and ethanol, dimethyl malonate, Active methylene series such as acetylacetone, thiol series such as butyl mercaptan and dodecyl mercaptan, acid amides such as acetaniline and acetic acid amide, ε-caprolactam, δ - Lactamides such as valerolactamide, acid imides such as succinimide and maleimide, oximes such as acetaldehyde oxime, acetone oxime, and methyl ethyl ketone oxime, A blocking agent for amines such as diphenylaniline, aniline, and ethyleneimine.

Furthermore, it is preferable to introduce a hydrophilic group into the blocked isocyanate crosslinking agent from the viewpoint of imparting water dispersibility with respect to an aqueous solvent. Furthermore, as the hydrophilic group, introduction of an anionic group such as a carboxyl group or a sulfonic acid group, or a nonionic group such as an oxyalkyl group is preferable. These hydrophilic groups are prepared by reacting a polyisocyanate serving as a base of the blocked isocyanate with a compound having a reactive group such as a hydrophilic group and a hydroxyl group in advance.

The above-mentioned crosslinking agent is preferably contained in an amount of not less than 5% by mass and not more than 50% by mass in the solid content of all resins and crosslinking agents contained in the coating layer forming composition. More preferably, it is 10 mass % or more and 45 mass % or less. More preferably, it is not less than 10% by mass and not more than 30% by mass, most preferably not less than 10% by mass and not more than 20% by mass. If it is more than 5% by mass, the strength of the resin of the coating layer can be maintained, and the adhesion under high temperature and high humidity is good. If it is less than 50% by mass, the flexibility of the resin of the coating layer can be maintained. The adhesiveness can be maintained under high temperature and high humidity, so it is better.

The coating layer of the easily-adhesive polyester film of the present invention is preferably composed of a polyester having a polycyclic aromatic skeleton and a crosslinking agent having at least one skeleton selected from the group consisting of aliphatic, alicyclic, and heterocyclic hardened. The expression of this composition hardened is described because it is difficult to properly express the chemical composition after hardening due to the crosslinking agent.

(additive) In the coating layer of the present invention, known additives such as surfactants, antioxidants, heat-resistant stabilizers, weather-resistant stabilizers, ultraviolet absorbers, organic slippery agents, and pigments can be added within the range that does not impair the effects of the present invention. , dyes, organic or inorganic particles, antistatic agents, nucleating agents, etc. However, it is preferable not to use substances that are harmful to the environment or the like.

In the present invention, in order to further improve the anti-blocking property of the coating layer, it is also a preferable aspect to add particles to the coating layer. In the present invention, as the particles contained in the coating layer, for example, titanium oxide, barium sulfate, calcium carbonate, calcium sulfate, silicon dioxide, alumina, talc, kaolin, clay, etc., or a mixture thereof, can be cited. There are other general inorganic particles, such as calcium phosphate, mica, spodumene, zirconia, tungsten oxide, lithium fluoride, calcium fluoride, inorganic particles used in combination with others, styrene-based, acrylic-based, melamine-based, Benzoguanamine-based, polysiloxane-based organic polymer particles, etc.

The average particle diameter of the inactive particles in the coating layer (the average particle diameter based on the number of particles obtained by SEM, the same applies hereinafter) is preferably 0.04 to 2.0 μm, more preferably 0.1 to 1.0 μm. When the average particle size of the inert particles is 0.04 μm or more, since it is easy to form unevenness on the surface of the film, the slipperiness and take-up properties of the film are improved, and the processability at the time of lamination is good, so it is preferable. . On the other hand, when the average particle diameter of the inert particles is 2.0 μm or less, it is more difficult for the particles to fall off, which is preferable. The particle concentration in the coating layer is preferably 1 to 20 mass % with respect to the resin component.

In the present invention, the coating layer thickness (d: nm) is preferably the following formula (1). 30 ≦ d ≦ 200 ...Formula (1) If it is adjusted within this range, it is preferable because both processability and adhesiveness can be easily achieved. More preferably, it is not less than 50 nm and not more than 150 nm, and still more preferably, it is not less than 70 nm and not more than 100 nm. When the thickness of the coating layer is 30 nm or more, since the adhesiveness is good, it is preferable. When the thickness of the coating layer is 200 nm or less, blocking is less likely to occur, which is preferable.

The thickness of the coating layer is based on a transmission electron microscope (TEM), and the section of the cut film is observed, and the average value of the thickness of the coating layer at 10 randomly measured locations is taken as the thickness of the coating layer.

The surface free energy (γ _s : mN/m) of the coating layer present on the surface of the easily-adhesive polyester film of the present invention is preferably within the range of the following formula (2). 43 ≦ γ _s ≦ 49 ... When formula (2) is adjusted within this range, bonding reliability can be ensured and the requirement of the present invention can be satisfied. More preferably, it is not less than 44 mN/m and not more than 48 mN/m, and still more preferably not less than 45 mN/m and not more than 47 mN/m. When it is 43mN/m or more, the proportion of segregation components that tend to exist on the surface of the coating layer is small, and the adhesion with the hard coat layer applied later is good, especially the stability and reliability of the adhesion over time can be ensured, and is better. Moreover, when it is 49 mN/m or less, since the adhesiveness with the initial hard-coat layer can maintain a high degree, it is preferable.

The present invention focuses on the ratio of segregated components (mainly crosslinking agent components) existing from the surface to the inside of the coating layer.

The so-called segregation components here refer to urea compounds and urethane compounds that are deformed due to the reaction of the crosslinking agent components in the coating layer forming composition due to the reaction with moisture in the air. It exists on the surface and becomes the cause of reducing the adhesion with the hard coat layer and the like.

When observing the coating layer existing on the surface of the easily-adhesive polyester film of the present invention according to X-ray photoelectron spectroscopy (ESCA), it is preferable that the ratio of the amount of nitrogen atoms relative to the total amount of all elements (nitrogen atom ratio A _N : at %) falls within the range of the following formula (3). 3.0 ≦ A _N ≦ 9.5 ...Equation (3) If adjusted within this range, it is better because bonding reliability can be ensured. More preferably, it is not less than 5.0at% and not more than 9.3at%, and more preferably not less than 7.0at% and not more than 9.0at%. When it is 3.0 at% or more, the adhesiveness with the initial hard-coat layer becomes favorable, and it is preferable. When it is 9.5 atomic % or less, since the adhesiveness with a hard-coat layer is stable even after time passes, and adhesive reliability can be maintained, it is preferable.

In the ESCA measurement, the surface of the coating layer of the easy-adhesive polyester film of the present invention is etched in the depth direction, and when the nitrogen element distribution curve measured according to the element distribution at each position in the depth direction is drawn, it can be obtained as shown in Figure 1. The spectrum is shown (horizontal axis: etching time (seconds), vertical axis: ratio of nitrogen atoms (at%)). In the obtained distribution curve, the time (t ₁ ) (seconds) when the nitrogen atomic ratio becomes the lower limit value, and the nitrogen atomic ratio becomes the middle value between the maximum value (A _N X ) and the lower limit value (A _N Y ) The time (t ₂ ) (seconds) of ( _AN Z) is preferably within the range of the following formula (4). (t ₂ /t ₁ ) × 100 ≧ 40 ... Formula (4) The time (t ₂ ) of A _N Z means the time between the maximum value (A _N X ) and the lower limit value (A _N Y ). At , the ratio of (t ₂ ) to (t ₁ ) means the breadth of the ratio of nitrogen atoms in the depth direction. That is, the larger the ratio of the overall width (t ₂ ) to (t ₁ ) in the depth direction is, the more moderate the change in the amount of segregation components from the surface of the coating layer is. More preferably, it is 47 or more, and still more preferably, it is 55 or more. When it is 40 or more, since the amount of biased existence of segregation components becomes small, it is affected and adhesion reliability can be maintained, which is preferable.

The method for satisfying the formula (2), formula (3) and formula (4) is not particularly limited, but it is preferable to control the type and ratio of the resin and the crosslinking agent in the coating layer forming composition. be adjusted.

Then, when all the relational expressions of the equations (1) to (4) are satisfied, excellent transparency, anti-blocking property, and adhesion to the hard coat layer can be obtained, especially adhesion stability over time High, easy-adhesive polyester film with high reliability as a film.

In the coating layer forming composition, a surfactant can also be contained for the purpose of improving the level dyeing property at the time of coating and defoaming the coating liquid. The surfactant system can be any one of cationic, anionic, nonionic, etc., preferably polysiloxane-based, acetylene glycol-based or fluorine-based surfactants. Such surfactants are preferably contained in the coating layer forming composition within a range in which the effect of suppressing iridescent colors under fluorescent lamps and the adhesiveness are not impaired.

As the coating method, the so-called in-line coating method is applied when the polyester base film is formed into a film, and the so-called off-line coating method is applied separately with a coater after the polyester base film is formed into a film. Either, but is preferred because of the more efficient in-line coating method.

As the coating method, a known arbitrary method can be used as a method for coating a coating liquid on a polyethylene terephthalate (hereinafter abbreviated as PET) film. For example, reverse roll coating method, gravure coating method, dot coating method, die coating method, roll brush coating method, spray coating method, air knife coating method, wire bar coating method, tubular doctor blade method, dip coating method, curtain coating etc. Coating may be performed by these coating methods alone or in combination.

In the present invention, as a method of forming a coating layer on a polyester film, a method of coating a coating solution containing a solvent, particles, and a resin on a polyester film and drying it is exemplified. Examples of the solvent include water or a mixture of water and an organic solvent, but water alone or a mixture of water and a water-soluble organic solvent is preferred from the viewpoint of environmental issues. For example, examples of water-soluble organic solvents include alcohols such as isopropanol and ethanol, ketones such as methyl ethyl ketone, ethers such as butylcytosol, and amines such as triethanolamine. , N-methylpyrrolidone and other amides.

The solid content concentration of the coating liquid depends on the type of binder resin, the type of solvent, etc., and is preferably at least 2% by mass, more preferably at least 4% by mass. The solid content concentration of the coating liquid is preferably at most 35% by mass, more preferably at most 15% by mass.

The drying temperature after coating also depends on the type of binder resin, type of solvent, presence or absence of cross-linking agent, solid content concentration, etc., but it is preferably 80°C or higher, preferably 250°C or lower.

(Manufacture of easy-adhesive polyester film) The polyester film which becomes the base material of the easily-adhesive polyester film of this invention can be manufactured according to the general polyester film manufacturing method. For example, polyester resin is melted and extruded into a sheet, and the formed unaligned polyester is stretched in the longitudinal direction at a temperature above the glass transition temperature by using a roller speed difference, and then stretched by drawing. The method of extending the frame in the transverse direction and then applying heat treatment.

The polyester film of the present invention may be a uniaxially stretched film or a biaxially stretched film, and when the biaxially stretched film is used as a protective film on the front of a liquid crystal panel, even if it is observed from directly above the film surface, Iridescent stains are not seen, but when viewed obliquely, iridescent stains may be observed, so attention should be paid.

This phenomenon is that the biaxially stretched film is composed of refractive index ellipsoids with different refractive indices in the traveling direction, width direction, and thickness direction, and the hysteresis becomes 0 due to the light penetration direction inside the film (refractive index ellipsoid It looks like the existence of the direction of a perfect circle). Therefore, when the liquid crystal display screen is observed from a specific oblique direction, there will be a place where the hysteresis becomes zero, and around this place as the center, a rainbow-like color spot will be generated like a concentric circle. Then, when θ is the angle from directly above the film surface (normal direction) to the position where iridescent spots can be seen, this angle θ increases as the in-plane birefringence of the film increases, becoming It is difficult to see the iridescence. Since the biaxially stretched film tends to have a smaller angle θ, the uniaxially stretched film is preferable because it becomes difficult to see iridescent spots.

However, in the case of a completely uniaxial (monoaxially symmetric) film, the mechanical strength in the direction perpendicular to the alignment direction is remarkably lowered, which is unfavorable. The present invention preferably has biaxiality (biaxial symmetry) in a range in which iridescent stains do not substantially occur, or in a range in which iridescent stains do not occur in the range of viewing angles required for liquid crystal display screens.

(Laminated polyester film) On the coating layer of the easily adhesive polyester film of the present invention, a functional layer such as a hard coat layer can be laminated to form a laminated polyester film, and it can preferably be used mainly for optical purposes. A hard coat layer made of electron beams, ultraviolet curable acrylic resin, silicone-based thermosetting resin, or the like may be provided on the aforementioned coating layer.

It is also a preferred form to arrange various functional layers on the coating layer of the easily-adhesive polyester film of the present invention. The so-called functional layer refers to anti-glare layer, anti-glare anti-reflection layer, anti-reflection layer, Functional layers such as low reflection layer and antistatic layer. Various layers known in this technical field can be used for the functional layer system, and the types thereof are not particularly limited. Hereinafter, each functional layer will be described.

For example, for the formation of the hard coat layer, known materials for the hard coat layer can be used without particular limitation, and any one of the hard coat layer by drying, heat, chemical reaction, or irradiating electron beams, radiation, and ultraviolet rays can be used. and polymerized and/or reacted resin compounds. Examples of such curable resins include melamine-based, acrylic-based, polysiloxane-based, and polyvinyl alcohol-based curable resins. From the viewpoint of obtaining high surface hardness and optical design, photocurable resins are preferred. Acrylic curable resin. As such acrylic curable resins, polyfunctional (meth)acrylate monomers or acrylate oligomers can be used. Examples of acrylate oligomers include polyester acrylate, cyclo Oxygen acrylate, urethane acrylate, polyether acrylate, polybutadiene acrylate, silicone acrylate, etc. By mixing a reactive diluent, a photopolymerization initiator, a sensitizer, etc. into these acrylic curable resins, a coating composition for forming the aforementioned optical function layer can be obtained.

The above-mentioned hard coat layer may have an anti-glare function to scatter external light. The anti-glare function can be obtained by forming concavo-convex on the surface of the hard coat. In this case, ideally, the haze value of the film is preferably from 0 to 50%, more preferably from 0 to 40%, and most preferably from 0 to 30%. Of course, 0% is ideal, and may be 0.2% or more, or 0.5% or more.

In addition, in order to apply low-reflection processing (anti-reflection treatment) to suppress light reflection by giving layers with different refractive indices and changing the light transmission characteristics, it is preferable to adjust the refractive index for the hard coat layer and functional layer, and ideally It is preferable to achieve a reflectance of 0 to 1.0%, more preferably 0 to 0.8%, and most preferably 0 to 0.5%. Of course, 0% is ideal, and may be 0.05% or more, or 0.1% or more.

In particular, as the hard coat composition used in the present invention, in order to adjust the refractive index, it is generally used in an amount of 5 mol% or more relative to the total number of moles of monomers and oligomers constituting the resin. Resins containing aromatic components in a proportion of less than 20 mole %.

The application of the laminated polyester film with a functional layer laminated on the easily adhesive polyester film of the present invention and its coating layer is mainly the entire optical film, and it can be suitably used in prism sheets, AR (anti-reflection) films, Hard-coated film, diffusion plate, shatterproof film, etc., base film for optical components such as LCD and flat-panel TV, CRT, etc., near-infrared absorption filter, touch panel and electroluminescent component on the front panel of plasma display Luminescent transparent conductive film, etc.

As the acrylic resin hardened by electron rays or ultraviolet rays for forming the above-mentioned hard coat layer, more specifically, it has an acrylate-based or methacrylate-based functional group, for example, a relatively low-molecular-weight polyester Resins, polyether resins, acrylic resins, epoxy resins, urethane resins, alkyd resins, screw acetal resins, polybutadiene resins, polythiol polyene resins, polyols, etc., can be used containing Monofunctional monomers such as ethyl (meth)acrylate, ethylhexyl (meth)acrylate, and polyfunctional monomers, such as trimethylolpropane tri(meth)acrylate, hexanediol (methyl) Acrylates, Tripropylene Glycol Di(meth)acrylate, Diethylene Glycol Di(meth)acrylate, Neopentylthritol Tri(meth)acrylate, Dineopentyl Glycol Hexa(meth)acrylate, 1,6-Hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, etc., oligomers or prepolymers of (meth)acrylate etc. as polyfunctional compounds and Reactive diluent.

類，作為光增感劑，可以混合使用正丁胺、三乙胺、三正丁基膦等。In addition, in the case of electron beam or ultraviolet curable resins, as a photopolymerization initiator in the aforementioned resins, acetophenones, benzophenones, miller benzoyl benzoate, α-pentoxime ester, tetramethylaminothioformyl monosulfide, 9-oxosulfur 𠮿

As a photosensitizer, n-butylamine, triethylamine, tri-n-butylphosphine, etc. can be mixed and used.

In addition, polysiloxane-based (siloxane-based) thermosetting resins can be produced by hydrolyzing and condensing organosilane compounds alone or in combination of two or more in the presence of an acid or alkali catalyst. Especially in the case of low reflection, it is more preferable to mix one or more kinds of fluorosilane compounds and make them hydrolyze and condense in order to improve the low refractive index property, stain resistance, and the like.

(manufacture of laminated polyester film) Although the manufacturing method of the laminated polyester film using the easily-adhesive polyester film of this invention is demonstrated, this invention is not limited to the concrete example demonstrated.

The aforementioned electron beam or ultraviolet curable acrylic resin, oligomer, monomer or siloxane-based thermosetting resin is coated on the coating layer of the aforementioned easy-adhesive polyester film. In the case where the coating layer is provided on both sides, it is coated on at least one coating layer. The coating liquid does not need to be diluted in particular, even if it is diluted with an organic solvent according to the viscosity, wettability, coating thickness, etc. of the coating liquid, there will be no special problem. The coating layer is formed after coating the above-mentioned coating liquid on the above-mentioned film, drying as needed, and then matching the hardening conditions of the coating liquid by irradiating electron rays or ultraviolet rays and heating to harden the coating layer to form a hard coat layer.

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 1 μm or more, the effects of the hard coat layer on chemical resistance, scratch resistance, and antifouling properties can be effectively exhibited, which is preferable. On the other hand, when the thickness is 15 μm or less, the flexibility of the hard coat layer can be maintained, and there is no possibility of cracks, etc., which is preferable.

As scratch resistance, when the coated surface is abraded with a black cardboard, it is preferable that damage is not conspicuous visually. If the damage is not obvious according to the above evaluation, it is difficult to be scratched when the guide roller passes, and it is preferable from the viewpoint of workability and the like.

Since the easily-adhesive polyester film and laminated polyester film of the present invention are mainly used for optical applications, they preferably have high transparency. The lower limit of the fog value is ideally 0%, and the closer to 0%, the better. The upper limit of the haze value is preferably 2%, and when it is 2% or less, the light transmittance is good, and a clear image can be obtained on a liquid crystal display device, so it is preferable. The haze value of a polyester film can be measured by the method mentioned later, for example.

On the easy-adhesive coating layer of the easily-adhesive polyester film, use the coating solution for forming a hard coat layer with the above-mentioned composition, and use a wire bar to coat it. For example, it can be dried at 70°C for 1 minute to remove the solvent. . Next, the hard-coated film is irradiated with ultraviolet rays of, for example, 300 mJ/cm ² using a high-pressure mercury lamp, thereby obtaining a laminated polyester film having a hard-coat layer.

Adhesion between the easily-adhesive coating layer and the hard coat layer can be obtained by evaluating the measurement method described later. The adhesiveness X after film formation is preferably 95% or more. More preferably, it is more than 98%, and even more preferably, it is 100%. When it is 95% or more, it can be said that the adhesiveness of a coating layer and a hard-coat layer is fully maintained. In addition, in the present invention, "after film formation" means continuous storage in a temperature environment of 40° C. or lower, and means within 6 months after film formation.

The adhesiveness Y of the easy-adhesive coating layer and the hard coat layer under high temperature and high humidity conditions of 80°C and 95%RH, which is evaluated according to the method described later, is the same as above, and the adhesion is preferably 95% or more. More preferably, it is more than 98%, and even more preferably, it is 100%. When it is more than 95%, under high temperature and high humidity conditions, the adhesion between the easy-adhesive coating layer and the hard coat layer can be satisfied, and the passability of the post-processing steps can be satisfied.

Originally, it is better to evaluate the adhesiveness of the easy-adhesive polyester film after it has been left for a few weeks to several months at room temperature. As an alternative measure, it is evaluated by standing in a high-temperature and high-humidity environment of 80°C and 90%RH for 24 hours.

The easy-adhesive polyester film of the present invention is a film with high adhesion reliability, and even after being exposed to a high-temperature and high-humidity environment, its effect can still show high adhesion. Therefore, the above-mentioned X(%) and Y(%) satisfy the following formula (5). X-Y(%) ≦ 5 ...Formula (5)

The value of formula (5) is preferably 5% or less. More preferably, it is 2% or less, and still more preferably, it is 0%. When it is 5% or less, the difference between the adhesiveness after film formation and the adhesiveness after moist heat treatment is small, and it can be said that there is sufficient adhesion after film formation and after moist heat treatment. This is considered to be related to the characteristic that the adhesiveness of the hard coat layer does not decrease even after long-term storage.

The easy-adhesive polyester film of the present invention can be used in various applications, but it is preferably used in the manufacturing process of the polarizing plate used in the liquid crystal display device, especially as a protection for the polarizer constituting the polarizing plate. film to use. Generally speaking, polarizers are mostly made of polyvinyl alcohol. The easily adhesive polyester film of the present invention can be made of polyvinyl alcohol, and an adhesive such as a crosslinking agent is applied on it to adhere to polarized light. mirror. At this time, it is preferable to use the coating layer of the easily-adhesive polyester film of the present invention not facing the side that is in contact with the polarizer, but facing the opposite side. On the surface attached to the polarizer of the easily-adhesive polyester film of the present invention, it is preferable to laminate a polyester-based resin, polyvinyl alcohol-based resin and Easy-to-adhesive layer of cross-linking agent. [Example]

Next, the present invention will be described in detail using examples, comparative examples, and reference examples, but the present invention is of course not limited to the following examples. In addition, the evaluation method used in this invention is as follows.

(1) Average particle size [Measurement method of scanning electron microscope] The measurement of the average particle diameter of the said particle|grains can be performed by the following method. Take pictures of the particles with a scanning electron microscope (SEM), and measure the maximum diameter (the distance between the two furthest points) of 300 to 500 particles according to the magnification of the smallest particle size of 2 to 5 mm, and average them The value is taken as the average particle size. The average particle diameter of the particle|grains which exist in the coating layer of this invention can be measured by this measuring method.

[Dynamic light scattering method] The average particle diameter of particles can also be obtained by dynamic scattering method during the manufacture of particles and thin films. The sol was diluted with a dispersion medium, and the parameters of the dispersion medium were used to measure with a subparticle analyzer N4 PLUS (manufactured by Beckman Coulter Co., Ltd.), and calculation was performed by the cumulant method to obtain an average particle diameter. In the dynamic light scattering method, the average particle diameter of the particles in the sol can be observed, and when there is aggregation of particles, the average particle diameter of the aggregated particles can be observed.

(2) Refractive index of particles The measurement of the refractive index of particles can be performed by the following method. After drying the inorganic particles at 150°C, immerse the powder pulverized with a mortar in solvent 1 (the one with a lower refractive index than the particles), and add a small amount of solvent 2 (with a higher refractive index) until the particles become almost transparent. on particles). The refractive index of this liquid was measured using the Abbe refractometer (Abe refractometer manufactured by ATAGO Co., Ltd.). The measurement system is carried out at 23°C under D-ray (wavelength 589nm). The above-mentioned solvent 1 and solvent 2 can be selected to be mixed with each other, depending on the refractive index, for example, 1,1,1,3,3,3-hexafluoro-2-propanol, 2-propanol, chloroform, tetra Solvents such as carbon chloride, toluene, glycerin, etc.

(3) Haze value of optical adhesive polyester film The haze value of the easily-adhesive polyester film was measured using a haze meter (NDH2000 manufactured by Nippon Denshoku Co., Ltd.) in accordance with JIS K 7136:2000.

(4) Adhesiveness (adhesiveness X after film making) A hard coat layer was formed on the easily-adhesive coating layer of the polyester film obtained in Examples. According to the description in 8.5.1 of JIS-K5400-1990, the adhesiveness of a hard-coat layer and a base film was calculated|required about the easy-adhesive polyester film which formed the hard-coat layer.

The coating liquid used for hard-coat formation was prepared as follows.

(Preparation of Coating Liquid L for Hard Coat Formation) Methyl ethyl ketone 64.40% by mass Dineopentylthritol hexaacrylate 27.20% by mass (A-DPH manufactured by Shin-Nakamura Chemical Co., Ltd.) Polyethylene glycol diacrylate 3.40% by mass (LightAcrylate 9EG-A manufactured by Kyoeisha Chemical Co., Ltd.) Bisphenol A diacrylate 4.00% by mass (LightAcrylate BP-4PA manufactured by Kyoeisha Chemical) Photopolymerization initiator 1.00% by mass (Omnirad 184 by IGM Resins B.V.) The aromatic components in all the resins in the prepared hard coating solution L were 13.3% in molar ratio.

(Formation of hard coat layer) The easy-adhesive polyester film produced in the following examples was stored at 20°C and 65%RH temperature and humidity. The coating solution for coating layer formation was coated on the easily-adhesive coating layer, and dried at 70° C. for 1 minute to remove the solvent. Next, the hard-coated film was irradiated with 300 mJ/cm ² of ultraviolet rays using a high-pressure mercury lamp to obtain a hard-coated film with a thickness of 7 μm.

The specific measurement method of adhesion is as follows. Using a cutter guide with a gap interval of 2mm, 100 mesh cuts penetrating through the hard coat layer to reach the substrate film are brought into contact with the hard coat layer surface. Next, cellophane adhesive tape (manufactured by Nichiban, No. 405; 24 mm width) was attached to the mesh-shaped incision surface, and rubbed with an eraser to completely adhere. Thereafter, the cellophane adhesive tape was peeled off vertically from the hard coat surface of the easy-adhesive polyester film formed with the hard coat layer, and the number of layers of the easy-adhesive polyester film formed with the hard coat layer was visually counted. The number of meshes peeled off the hard coat surface can be obtained from the following formula to obtain the adhesion between the hard coat layer and the substrate film. In addition, the partial peeling of the mesh is also counted as the mesh that has been peeled off. Adhesiveness (%)={1-(Number of meshes stripped/100)}×100

(5) Moisture and heat resistance (adhesion after being placed at 80°C and 90%RH: Adhesion Y after heat and humidity treatment) The obtained easily-adhesive polyester film was left in an environment of 80° C. and 90% RH for 24 hours in a high-temperature, high-humidity tank, and then left at room temperature (20° C., 65% RH) for 12 hours. Thereafter, a hard coat layer was formed in the same manner as described above, and the adhesion was determined.

(6) Adhesiveness Z of hard coating after 6 months of easy-adhesive polyester film roll Put the film roll of easy-adhesive polyester film in the environment of temperature: 0℃～30℃, humidity: 10%RH～80%RH for 6 months, take the film roll after placing it from the sample, and do the same as above Specifically, a hard coat layer was formed on the easily-adhesive coating layer, and the adhesiveness was evaluated. Regarding the adhesion reliability based on the adhesiveness Z, 99% or more was made ⊚, 95% or more and less than 99% was made ◯, and less than 95% was made x. If the adhesion Z is more than 95%, the adhesion reliability ◎ and ○ are considered acceptable.

(7) Number average molecular weight Dissolve 0.03 g of the resin in 10 ml of tetrahydrofuran, use a GPC-LALLS device low-angle light scattering photometer LS-8000 (manufactured by TOSOH Co., Ltd., tetrahydrofuran solvent, control group: polystyrene), use a column temperature of 30 ° C, flow A 1 ml/min column (Shodex KF-802, 804, 806 manufactured by Showa Denko Co., Ltd.) was used to measure the number average molecular weight.

(8) Sectional observation by transmission electron microscope The obtained easy-adhesive polyester film was cut into 1 mm×10 mm, and after embedding in epoxy resin, an ultramicrotome was used to make a cross-sectional thin section parallel to the short side of the embedded sample piece. Next, a portion of the sliced thin film stained with ruthenium tetroxide without significant damage was observed with a transmission electron microscope (JEM2100 manufactured by JEOL Ltd.) at an acceleration voltage of 200 kV and 20000 times. The thickness of the coating layer was measured at 10 locations from the observed image of the coating layer, and the average value thereof was regarded as the thickness of the coating layer.

(9) Surface free energy Under the conditions of 25°C and 50%RH, use a contact angle meter (manufactured by Kyowa Interface Science Co., Ltd.: Automatic Contact Angle Meter DM-701), and the obtained easy-adhesive polyester film On the coated surface, droplets of water (droplet volume: 1.8 µL) and diiodomethane (droplet volume: 0.9 µL) were produced, and the contact angles thereof were measured. As for the contact angle, the contact angle obtained by dropping each liquid onto the easily-adhesive polyester film for 10 seconds was used. Using "Kitaki Kazuhata" theory to calculate the contact angle data of water and methylene iodide, and calculate the dispersion component γ _sd and hydrogen bond component γ _s of the surface free energy of the easily adhesive polyester film. is the surface free energy γ _s . In this calculation, the calculation software in this contact angle meter software (FAMAS) is used.

(10) Nitrogen atomic ratio evaluation on the surface of the coating layer The ratio of the nitrogen atomic weight (nitrogen atomic ratio (A _N : at %)) to the total amount of all elements in the surface area is determined by X-ray photoelectron spectroscopy (ESCA) (Thermo Fisher Scientific K-Alpha ⁺ ) was evaluated. The measurement conditions are as follows. In addition, at the time of analysis, background removal was performed by Shirley's method. In addition, the calculation of A _N is the average value of the measurement results of three places. Measurement conditions Excitation X-ray: Monochromatic Al Kα ray X-ray output: 12kV, 6mA Photoelectron detachment angle: 90° Spot size: 400μmφ Transition energy: 50eV Step: 0.1eV

(11) Measurement of Nitrogen Element Distribution in Depth Direction The measurement of element distribution in the depth direction of the coating layer was performed by X-ray photoelectron spectroscopy (ESCA) (K-Alpha ⁺ manufactured by Thermo Fisher Scientific). As an ion source for etching, Ar clusters that are expected to have low damage to organic materials are used. In addition, the sample is rotated during etching which can be uniformly etched. In order to minimize the damage caused by X-ray irradiation, the spectral collection of each etching time is carried out in a snapshot mode that can be evaluated in a short time. In addition, spectrum collection is performed every 30 seconds within 120 seconds of etching time, every 60 seconds within 720 seconds, and every 120 seconds within 1200 seconds according to the evaluation suitability. once. Details of the measurement conditions are shown below. In addition, during the analysis, the removal of the background was performed by Shirley's method. Measurement conditions Excitation X-ray: Monochromatic Al Kα ray X-ray output: 12kV, 2.5mA Photoelectron detachment angle: 90° Spot size: 200μmφ Transition energy: 150eV (snapshot mode) Acceleration voltage of ion gun: 6kV Agglomerate size: Small Etching rate: 15nm/min (polystyrene conversion)* Sample rotation during etching: yes In the calculation of etching rate, monodisperse polystyrene with molecular weight (Mn: 91000; Mw/Mn=1.05) was dissolved in After soaking in toluene, a film thickness of 155nm was produced on a silicon wafer by spin coating.

Based on the data thus evaluated, a nitrogen analysis curve was plotted with the etching time from the surface of the coating layer as the horizontal axis and the ratio of nitrogen atomic weight to the total amount of all elements (nitrogen atomic ratio) as the vertical axis. One example of the distribution curve is shown in FIG. 1 .

In the distribution curve shown in Fig. 1, read the etching time (t ₁ ) (seconds) when no large change is seen (becomes the lower limit), and read the maximum amount of nitrogen atomic ratio ( _AN X: at %) and the lower limit value (A _N Y: at%), the etching time (t ₂ ) at the middle value (A _N Z: at%), according to the above formula (4), obtain the ratio, so as to represent the segregation Component-biased approach to presence. Here, the reading of _t1 is determined as follows. Draw 3 points sequentially from the left end of the horizontal axis in Figure 1, and set the etching time from the left to t _1-1 (seconds), t _1-2 (seconds), t _1-3 (seconds) When, set the nitrogen atomic ratio value of the etching time (t _1-1 ) as n ₁ (at%), and set the next (after 30 seconds, 60 seconds or 120 seconds) etching time (t _1-2 ) is set to n ₂ (at%), and further set the next (after 30 seconds, 60 seconds or 120 seconds) the nitrogen atom ratio value of the etching time (t _1-3 ) to n In the case of ₃ (at%), when obtaining the average value of these 3 points (n ₁ , n ₂ , n ₃ ) and the difference from n ₁ , check whether the following relationship (6) is satisfied until it is satisfied , continue to select 3 consecutive points in sequence (t _1-1 (seconds) of the next 3 points corresponds to the above t _1-2 (seconds)), and the first one that satisfies the relation (6) t _1-1 (seconds) is set as etching time t ₁ (seconds). │n ₁ -(n ₁ +n ₂ +n ₃ )/3│≦0.010(at%) …Formula (6) Regarding the lower limit (A _N Y), set the nitrogen atomic ratio of t ₁ (seconds) value. According to this lower limit value, A _N Z is obtained from the following formula (7), A _N Z=(A _N XA _N Y)/2 ... Formula (7) Let the etching time at this time be t ₂ (seconds) .

(Polymerization of Copolyester Resin (A) for Coating Layer) 342.0 parts by mass of 2,6-dimethyl naphthalate, 35.0 parts by mass of dimethyl terephthalate, 35.5 parts by mass of dimethyl isophthalate-5-sodium sulfonate (dimethyl-5- Sodium sulfoisophthalate), 198.6 parts by mass of ethylene glycol, 118.2 parts by mass of 1,6-hexanediol, and 0.4 parts by mass of tetra-n-butyl titanate were added to a tank equipped with a stirrer, a thermometer, and a partial reflux cooler In an autoclave made of stainless steel, the transesterification reaction was performed at a temperature of 160°C to 220°C over 4 hours. Next, 60.7 parts by mass of sebacic acid was added to carry out an esterification reaction. Then, the temperature was raised to 255° C., and after the reaction system was slowly decompressed, it was reacted under a reduced pressure of 30 Pa for 1 hour and 30 minutes to obtain a copolyester resin (A). The obtained copolyester resin (A) was light yellow and transparent. The reduced viscosity of the copolyester resin (A) was measured and found to be 0.72dl/g. The glass transition temperature according to DSC is 40°C, and the number average molecular weight is 20,000.

(Polymerization of Copolyester Resin (B) for Coating Layer) 293.0 parts by mass of 2,6-dimethyl naphthalate, 128.0 parts by mass of dimethyl terephthalate, 41.6 parts by mass of dimethyl isophthalate-5-sodium sulfonate, 125.0 parts by mass of Ethylene glycol, 105.0 parts by mass of diethylene glycol, 142.0 parts by mass of 1,6-hexanediol, and 0.4 parts by mass of tetra-n-butyl titanate are added to a device equipped with a stirrer, a thermometer, and a local reflux cooler In an autoclave made of stainless steel, the transesterification reaction was carried out at a temperature of 160°C to 220°C over 4 hours. Next, the temperature was raised to 255° C., and after the reaction system was slowly decompressed, it was reacted under a reduced pressure of 30 Pa for 1 hour and 30 minutes to obtain a copolyester resin (B). The obtained copolyester resin (B) was pale yellow and transparent. The reduced viscosity of the copolyester resin (B) was measured and found to be 0.69dl/g. The glass transition temperature according to DSC is 30°C, and the number average molecular weight is 21000.

(Polymerization of Copolyester Resin (C) for Coating Layer) 145.6 parts by mass of dimethyl terephthalate, 14.8 parts by mass of dimethyl isophthalate-5-sodium sulfonate, 43.3 parts by mass of dimethyl azelate, 80.7 parts by mass of ethylene glycol, 131.6 parts by mass of 9,9-bis[4-(2-hydroxyethoxy)phenyl] fluorene, 70.9 parts by mass of 3-methyl-1,5-pentanediol, and 0.4 parts by mass of tetratitanate The n-butyl ester was charged into a stainless steel autoclave equipped with a stirrer, a thermometer, and a partial reflux cooler, and transesterification was carried out at a temperature of 160° C. to 220° C. for 4 hours. Next, the temperature was raised to 255° C., and after the reaction system was slowly decompressed, it was reacted under a reduced pressure of 30 Pa for 1 hour and 30 minutes to obtain a copolyester resin (C). The obtained copolyester resin (C) was pale yellow and transparent. The reduced viscosity of the copolyester resin (C) was measured to be 0.65dl/g. The glass transition temperature according to DSC is 40°C, and the number average molecular weight is 19,000.

(Polymerization of Copolyester Resin (D) for Coating Layer) In addition to 194.2 parts by mass of dimethyl terephthalate, 184.5 parts by mass of dimethyl isophthalate, 14.8 parts by mass of dimethyl isophthalate-5-sodium sulfonate, and 233.5 parts by mass of diethylene di Except for the alcohol, 136.6 parts by mass of ethylene glycol, and 0.2 parts by mass of tetra-n-butyl titanate, a copolyester resin (D) was obtained in the same manner as in the polymerization of the resin (A). The reduced viscosity of the obtained copolyester resin (D) was measured and found to be 0.70 dl/g. The glass transition temperature according to DSC is 40°C.

(Preparation of polyester aqueous dispersion (Aw), (Bw), (Cw), (Dw)) Add 30 parts by mass of copolyester resin (A) and 15 parts by mass of ethylene glycol n-butyl ether into a reactor equipped with a stirrer, a thermometer and a reflux device, heat to 110° C., and stir to dissolve the resin. After the resin was completely dissolved, 55 parts by mass of water was slowly added to the polyester solution while stirring. After the addition, the solution was cooled to room temperature while stirring the solution, and a milky white polyester resin (A) aqueous dispersion Aw (resin A solution) having a solid content of 25.0% by mass was prepared.

In the same manner, the polyester resin (B) aqueous dispersion Bw (resin B solution) in which the copolyester resin (B) had been dissolved was produced.

In the same manner, the polyester resin (C) aqueous dispersion Cw (resin C solution) in which the copolyester resin (C) had been dissolved was produced.

In the same manner, polyester resin (D) aqueous dispersion Dw (resin D solution) in which copolyester resin (D) had been dissolved was produced.

(Manufacture of polyurethane aqueous dispersion (E)) [Polymerization of water-dispersible polyurethane resin composed of aliphatic polycarbonate polyol] 43.75 parts by mass of 4, 4-Diphenylmethane diisocyanate, 12.85 parts by mass of dimethylol butyric acid, 153.41 parts by mass of polyhexamethylene carbonate polyol with a number average molecular weight of 2000, and 0.03 parts by mass of dibutyltin dilaurate and 84.00 parts by mass of acetone as a solvent were put into a 4-neck flask equipped with a stirrer, a Dairy cooler, a nitrogen introduction tube, a silicone drying tube and a thermometer, and stirred at 75°C for 3 hours under a nitrogen atmosphere to confirm the reaction solution Reach the specified amine equivalent. Next, after cooling this reaction liquid to 40 degreeC, 8.77 mass parts of triethylamines were added, and the polyurethane prepolymer solution was obtained. Next, add 450 g of water to a reaction vessel equipped with a homogenizer capable of high-speed stirring, adjust to 25° C., and stir and mix at 2000 min ⁻¹ while adding the polyurethane prepolymer solution to carry out Water dispersed. Thereafter, acetone and a part of water were removed under reduced pressure to prepare a water-soluble polyurethane resin solution (resin E solution) having a solid content of 37% by mass. The glass transition temperature of the obtained polyurethane resin was -30 degreeC.

(Synthesis of crosslinking agent P) In a flask equipped with a stirrer, a thermometer, and a reflux cooler, drop 35.00 parts by mass of 3,5-dimethylpyrazole to 100 parts by mass of 1,6-hexamethylenebis The polyisocyanate compound (NCO concentration: 23.1%) and 17.5 parts by mass of N-methylpyrrolidone produced by isocyanate were kept at 70° C. for 1 hour under a nitrogen atmosphere. Thereafter, 12.50 parts by mass of dimethylolpropionic acid was dropped. The infrared spectrum of the reaction solution was measured, and after confirming that the absorption of the isocyanate group disappeared, 8.72 parts by mass of N,N-dimethylethanolamine was added. After stirring as it was for 1 hour, an appropriate amount of water was added to obtain a blocked isocyanate-based aqueous dispersion (crosslinking agent P solution) with a solid content of 40% by mass.

(Synthesis of crosslinking agent Q) In a flask equipped with a stirrer, a thermometer, and a reflux cooler, drop 35.00 parts by mass of 3,5-dimethylpyrazole to 100 parts by mass of cyclohexane diisocyanate produced by an existing method. A polyisocyanate compound (NCO concentration: 23.3%) having an isocyanuric acid structure and 17.5 parts by mass of N-methylpyrrolidone were kept at 70° C. for 1 hour under a nitrogen atmosphere. Thereafter, 12.50 parts by mass of dimethylolpropionic acid was dropped. The infrared spectrum of the reaction solution was measured, and after confirming that the absorption of the isocyanate group disappeared, 8.72 parts by mass of N,N-dimethylethanolamine was added. After stirring as it was for 1 hour, an appropriate amount of water was added to obtain a blocked isocyanate-based aqueous dispersion (crosslinking agent Q solution) having a solid content of 40% by mass.

(Synthesis of crosslinking agent R) In a flask equipped with a stirrer, a thermometer, and a reflux cooler, drop 35.00 parts by mass of 3,5-dimethylpyrazole to 100 parts by mass of 2,5-diisocyanate thiophene produced by an existing method The resulting polyisocyanate compound (NCO concentration: 23.1%) and 17.5 parts by mass of N-methylpyrrolidone were kept at 70° C. for 1 hour under a nitrogen atmosphere. Thereafter, 12.50 parts by mass of dimethylolpropionic acid was dropped. The infrared spectrum of the reaction solution was measured, and after confirming that the absorption of the isocyanate group disappeared, 8.72 parts by mass of N,N-dimethylethanolamine was added. After stirring as it was for 1 hour, an appropriate amount of water was added to obtain a blocked isocyanate-based aqueous dispersion (crosslinking agent R solution) with a solid content of 40% by mass.

(Synthesis of crosslinking agent S) In a flask equipped with a stirrer, a thermometer, and a reflux cooler, add 168 parts by mass of hexamethylene diisocyanate and 220 parts by mass of polyethylene glycol monomethyl ether (average molecular weight 400), and stir at 120°C for 1 hour , then add 26 parts by mass of 4,4'-dicyclohexylmethane diisocyanate and 3.8 parts by mass (2% by mass relative to the total isocyanate) of 3-methyl-1-phenyl as a carbodiimide catalyst -2-Phosphene-1-oxide was further stirred at 185° C. for 5 hours under a nitrogen atmosphere, and the infrared spectrum of the reaction solution was measured to confirm that the absorption of the isocyanate group disappeared. It was left to cool to 60°C, and 567 parts by mass of ion-exchanged water was added to obtain a carbodiimide-based crosslinking agent (crosslinking agent S solution) having a solid content of 40% by mass.

(Synthesis of crosslinking agent T) In a flask equipped with a stirrer, a thermometer, and a reflux cooler, drop 35.00 parts by mass of 3,5-dimethylpyrazole to 100 parts by mass of 2,4-toluene diisocyanate The polyisocyanate compound (NCO concentration: 22.3%) and 17.5 parts by mass of N-methylpyrrolidone produced by the ester were kept at 70° C. for 1 hour under a nitrogen atmosphere. Thereafter, 12.50 parts by mass of dimethylolpropionic acid was dropped. The infrared spectrum of the reaction solution was measured, and after confirming that the absorption of the isocyanate group disappeared, 8.72 parts by mass of N,N-dimethylethanolamine was added. After stirring as it was for 1 hour, an appropriate amount of water was added to obtain a blocked isocyanate-based aqueous dispersion (crosslinking agent T solution) with a solid content of 40% by mass.

(Zirconium dioxide particles) Into a 3-liter glass container, 2283.6 g of pure water and 403.4 g of oxalic acid dihydrate were charged and heated to 40° C. to prepare a 10.72% by mass oxalic acid aqueous solution. While stirring this aqueous solution, 495.8 g of zirconyl carbonate powder (ZrOCO ₃ , manufactured by AMR International Corp., containing 39.76% by mass in terms of ZrO ₂ ) was slowly added, mixed for 30 minutes, and then heated at 90° C. for 30 minutes. . Next, 1747.2 g of a 25.0% by mass tetramethylammonium hydroxide aqueous solution (manufactured by Tama Chemical Industry Co., Ltd.) was slowly added over 1 hour. At this time, the mixed solution was in the form of a slurry, and contained 4.0% by mass in terms of ZrO ₂ . This slurry was transferred to a stainless steel autoclave container, and hydrothermal treatment was performed at 145° C. for 5 hours. The product after the hydrothermal treatment is completely solized without unsoled matter. The obtained sol contained 4.0% by mass in the form of ZrO ₂ , had a pH of 6.8, and had an average particle diameter of 19 nm as determined by the dynamic light scattering method. Also, the sol was adjusted to a ZrO ₂ concentration of 2.0% by mass with pure water, and the measured transmittance was 88%. When the particles are observed with a transmission electron microscope, they are almost aggregated particles of ZrO ₂ primary particles of about 7 nm. For 4,000 _g of the zirconia sol with a ZrO concentration of 4.0% by mass obtained by the above-mentioned hydrothermal treatment, an ultrafiltration device was used to wash and concentrate while slowly adding pure water to obtain a ZrO concentration of 13.1% by mass and a pH of ₄ .9. 953 g of zirconia sol with a penetration rate of 76% when the concentration of ZrO ₂ is 13.1% by mass. The refractive index of the obtained zirconia-based fine particles was 1.75.

(Zirconium dioxide sol) 3.93 g of 20 mass % citric acid aqueous solution and 11.0 g of 25 mass % tetramethylammonium hydroxide aqueous solution were added to 300 g of zirconium _dioxide sol having a ZrO2 concentration of 13.1 mass % obtained by performing the above washing and concentration. After g, it was further concentrated with an ultrafiltration device to obtain 129 g of a high _- concentration zirconia sol with a ZrO concentration of 30.5% by mass. The obtained high-concentration zirconia sol has a pH of 9.3 and an average particle diameter of 19 nm obtained by dynamic light scattering. Also, this zirconia sol was stable for more than one month at 50°C without any sediment.

(Titanium dioxide particles) 12.09 kg of titanium tetrachloride aqueous solution containing 7.75% by mass of titanium tetrachloride (manufactured by Osaka Titanium Technology Co., Ltd.) on the basis of _TiO2 conversion and ammonia water containing 15% by mass of ammonia (Ube Industries Co., Ltd. )) 4.69kg were mixed to prepare a white slurry solution with a pH of 9.5. Next, this slurry was filtered and washed with pure water to obtain 9.87 kg of a hydrous titanic acid filter cake with a solid content of 10% by mass. Next, 11.28 kg of hydrogen peroxide water (manufactured by Mitsubishi Gas Chemical Co., Ltd.) containing 35% by mass of hydrogen peroxide and 20.00 kg of pure water were added to the filter cake, and heated at 80° C. for 1 hour with stirring. Further, 57.52 kg of pure water was added to obtain 98.67 kg of peroxytitanic acid aqueous solution containing 1% by mass of peroxytitanic acid in terms of TiO ₂ . The peroxotitanic acid aqueous solution is transparent yellow-brown and has a pH of 8.5.

Next, 4.70 kg of cation _- exchange resin (manufactured by Mitsubishi Chemical Co., Ltd.) was mixed with 98.67 kg of the aforementioned aqueous solution of titanic acid peroxide, and a mixture containing potassium stannate (Showa Chemical Co., Ltd. )) 12.33 kg of 1 mass % potassium stannate aqueous solution. Next, after separating the cation-exchange resin which captured potassium ion etc., it put into the autoclave (manufactured by Pressure-resistant Glass Industry Co., Ltd., 120L), and heated at 165 degreeC for 18 hours.

(Titania sol) Next, after cooling the obtained mixed aqueous solution to room temperature, it was concentrated using an ultrafiltration membrane device (manufactured by Asahi Kasei Co., Ltd., ACV-3010) to obtain a solution with a solid content of 10% by mass. 9.90 kg of water-dispersed sol containing titanium-based fine particles (hereinafter referred to as "P-1"). The solid content contained in the sol thus obtained was measured by the method described above, and it was a titanium-based fine particle (primary particle) composed of a composite oxide containing titanium and tin having a rutile crystal structure. Furthermore, the content of the metal components contained in the titanium-based fine particles was measured and found to be 87.2% by mass of TiO ₂ , 11.0% by mass of SnO ₂ , and 1.8% by mass of K ₂ O in terms of the oxides of the respective metal components. In addition, the pH of this mixed aqueous solution was 10.0. In addition, the water-dispersed sol containing titanium-based fine particles is transparent milky white, the average particle diameter of the aforementioned titanium-based fine particles contained in this water-dispersed sol is 35 nm, and the distribution frequency of coarse particles having a particle diameter of 100 nm or more is 0. %. Furthermore, the refractive index of the obtained titanium-based fine particles was 2.42.

(zirconium dioxide/titanium dioxide mixed sol) The zirconia particles and titania particles obtained above were mixed at respective ratios to prepare a zirconia/titania mixed sol with a solid content concentration of 13% by mass.

(Example 1) (Preparation of Coating Solution) A coating liquid having the composition described below was prepared. Water 36.47 parts by mass Isopropanol 37.42 parts by mass Silica sol 1.21 parts by mass (Silica sol with an average particle diameter of 40nm and a solid content concentration of 40% by mass) Silica sol 1.11 parts by mass (Silica sol with an average particle diameter of 450nm and a solid content concentration of 4% by mass) Resin A solution 20.06 parts by mass (solid content concentration 25% by mass) Crosslinking agent P solution 3.14 parts by mass (solid content concentration 40% by mass) Surfactant 0.25 parts by mass (Fluorine-based, solid content concentration 10% by mass) High boiling point solvent 0.34 parts by mass

(Manufacture of easy-adhesive polyester film) As a film base polymer, PET resin pellets having an intrinsic viscosity (solvent: phenol/tetrachloroethane = 60/40) of 0.65 dl/g and substantially no particles were dried at 135° C. under reduced pressure of 133 Pa for 6 hours. Thereafter, it is supplied to an extruder, melted and extruded into a thin sheet at about 280°C, and rapidly cooled and solidified on a rotating cooling metal drum whose surface temperature is kept at 20°C to obtain an unstretched PET film.

The unstretched PET film is heated to 100°C by a heated roller group and an infrared heater, and then stretched 3.5 times in the long-side direction by a roller group with a different peripheral speed to obtain a uniaxially stretched PET film .

Next, the above-mentioned coating liquid was applied on one side of the PET film by a roll coating method, and then dried at 80° C., and adjusted so that the coating amount after drying after final stretching was 0.12 g/m ² . Next, stretch 4.0 times in the width direction with a tenter at 150°C to fix the length of the film in the width direction, heat at 230°C, and then perform relaxation treatment in the width direction at 230°C. Film roll of easy-adhesive polyester film with a thickness of 38 μm.

The obtained easily-adhesive polyester film had an easily-adhesive coating thickness of 80 nm and a surface free energy of 46.3 mN/m.

Next, according to ESCA, the surface nitrogen atomic ratio is 8.6 at%, and the distribution curve of the nitrogen atomic ratio in the depth direction due to surface etching is shown in FIG. 2 . The t ₁ and t ₂ obtained from this result are respectively t ₁ =111 (seconds), t ₂ =65 (seconds), and the value obtained by the formula (4) is (t ₂ /t ₁ ) ×100=59 (seconds).

Next, a laminated polyester film was obtained by using the above-mentioned coating solution for forming a hard coat layer on the easily-adhesive coating layer of the easily-adhesive polyester film according to the above-mentioned forming method.

The adhesiveness of the hard coat layer of the obtained laminated polyester film was evaluated, and the adhesive force X was 100%.

Next, the obtained easily-adhesive polyester film was left in a high-humidity, high-temperature chamber in an environment of 80° C. and 90 RH% for 24 hours, and then left at room temperature for 12 hours. Then, on the easily-adhesive coating layer of the processed easily-adhesive polyester film, a hard-coat layer was formed using the coating liquid L for hard-coat layer formation, and the laminated polyester film was obtained.

The adhesiveness of the hard coat layer of the obtained laminated polyester film was evaluated, and the adhesive force Y was 100%.

According to this result, X-Y=0(%) can be obtained from formula (5). These results are described in Table 1.

Place the film roll of the above-mentioned easy-adhesive polyester film in the environment of temperature: 0℃～30℃, humidity: 10%RH～80%RH for 6 months, and take samples from the film roll after the storage, the same as above On the other hand, a hard coat layer was formed on the coating layer with good adhesion, and the adhesiveness Z was evaluated and described in Table 1.

As a result of the evaluation, the adhesion Z was 100%, and the adhesion reliability was ⊚, which belonged to those with good adhesion reliability.

(Example 2-3) An easily-adhesive polyester film was obtained in the same manner as in Example 1, except that the thickness of the coated resin layer was adjusted as shown in Table 1. The results are shown in Table 1.

(Example 4) Except having prepared the coating liquid of the composition mentioned below, it carried out similarly to Example 1, and obtained the easily-adhesive polyester film. Water 35.62 parts by mass Isopropanol 37.42 parts by mass Silica sol 1.21 parts by mass (Silica sol with an average particle diameter of 40nm and a solid content concentration of 40% by mass) Silica sol 1.11 parts by mass (Silica sol with an average particle diameter of 450nm and a solid content concentration of 4% by mass) Resin A solution 22.32 parts by mass (solid content concentration 25% by mass) Crosslinking agent P solution 1.72 parts by mass (solid content concentration 40% by mass) Surfactant 0.25 parts by mass (Fluorine-based, solid content concentration 10% by mass) High boiling point solvent 0.34 parts by mass

Evaluation of the obtained easily-adhesive polyester film was carried out in the same manner as in Example 1, and the results are shown in Table 1.

(Example 5) Except having prepared the coating liquid of the composition mentioned below, it carried out similarly to Example 1, and obtained the easily-adhesive polyester film. Water 37.41 parts by mass Isopropanol 37.42 parts by mass Silica sol 1.21 parts by mass (Silica sol with an average particle diameter of 40nm and a solid content concentration of 40% by mass) Silica sol 1.11 parts by mass (Silica sol with an average particle diameter of 450nm and a solid content concentration of 4% by mass) Resin A solution 17.56 parts by mass (solid content concentration 25% by mass) Crosslinking agent P solution 4.70 parts by mass (solid content concentration 40% by mass) Surfactant 0.25 parts by mass (Fluorine-based, solid content concentration 10% by mass) High boiling point solvent 0.34 parts by mass

Evaluation of the obtained easily-adhesive polyester film was carried out in the same manner as in Example 1, and the results are shown in Table 1.

(Example 6) Except having prepared the coating liquid using the crosslinking agent Q solution, it carried out similarly to Example 1, and obtained the easily-adhesive polyester film. Evaluation of the obtained easily-adhesive polyester film was carried out in the same manner as in Example 1, and the results are shown in Table 1.

(Example 7) Except having prepared the coating liquid using the crosslinking agent R solution, it carried out similarly to Example 1, and obtained the easily-adhesive polyester film. Evaluation of the obtained easily-adhesive polyester film was carried out in the same manner as in Example 1, and the results are shown in Table 1.

(Embodiment 8) Except having prepared the coating liquid using the crosslinking agent S solution, it carried out similarly to Example 1, and obtained the easily-adhesive polyester film. Evaluation of the obtained easily-adhesive polyester film was carried out in the same manner as in Example 1, and the results are shown in Table 1.

(Example 9) Except having prepared the coating liquid using the resin B solution, it carried out similarly to Example 1, and obtained the easily-adhesive polyester film. Evaluation of the obtained easily-adhesive polyester film was carried out in the same manner as in Example 1, and the results are shown in Table 1.

(Example 10) Except having prepared the coating liquid using the resin C solution, it carried out similarly to Example 1, and obtained the easily-adhesive polyester film. Evaluation of the obtained easily-adhesive polyester film was carried out in the same manner as in Example 1, and the results are shown in Table 1.

(Example 11) Except having prepared the coating liquid of the composition mentioned below, it carried out similarly to Example 1, and obtained the easily-adhesive polyester film. Water 36.47 parts by mass Isopropanol 37.42 parts by mass Zirconia sol 1.21 parts by mass Silica sol 1.11 parts by mass (Silica sol with an average particle diameter of 450nm and a solid content concentration of 4% by mass) Resin A solution 20.06 parts by mass (solid content concentration 25% by mass) Crosslinking agent P solution 3.14 parts by mass (solid content concentration 40% by mass) Surfactant 0.25 parts by mass (Fluorine-based, solid content concentration 10% by mass) High boiling point solvent 0.34 parts by mass

Evaluation of the obtained easily-adhesive polyester film was carried out in the same manner as in Example 1, and the results are shown in Table 1.

(Example 12) Except having prepared the coating liquid of the composition mentioned below, it carried out similarly to Example 1, and obtained the easily-adhesive polyester film. Water 36.47 parts by mass Isopropanol 37.42 parts by mass Titanium dioxide sol 1.21 parts by mass Silica sol 1.11 parts by mass (Silica sol with an average particle diameter of 450nm and a solid content concentration of 4% by mass) Resin A solution 20.06 parts by mass (solid content concentration 25% by mass) Crosslinking agent P solution 3.14 parts by mass (solid content concentration 40% by mass) Surfactant 0.25 parts by mass (Fluorine-based, solid content concentration 10% by mass) High boiling point solvent 0.34 parts by mass

Evaluation of the obtained easily-adhesive polyester film was carried out in the same manner as in Example 1, and the results are shown in Table 1.

(Example 13) Except having prepared the coating liquid of the composition mentioned below, it carried out similarly to Example 1, and obtained the easily-adhesive polyester film. Water 36.47 parts by mass Isopropanol 37.42 parts by mass Zirconia/titania mixed sol 1.21 parts by mass (Zirconium dioxide mass 75% by mass relative to the total mass of zirconia/titania, solid content concentration 13% by mass) Silica sol 1.11 parts by mass (Silica sol with an average particle diameter of 450nm and a solid content concentration of 4% by mass) Resin A solution 20.06 parts by mass (solid content concentration 25% by mass) Crosslinking agent P solution 3.14 parts by mass (solid content concentration 40% by mass) Surfactant 0.25 parts by mass (Fluorine-based, solid content concentration 10% by mass) High boiling point solvent 0.34 parts by mass

Evaluation of the obtained easily-adhesive polyester film was carried out in the same manner as in Example 1, and the results are shown in Table 1.

(Comparative examples 1-2) Except for adjusting the thickness of the applied resin layer as set forth in Table 1, it was carried out in the same manner as in Example 1 to obtain an easily-adhesive polyester film. The results are shown in Table 1.

(comparative example 3) Except having prepared the coating liquid of the composition mentioned below, it carried out similarly to Example 1, and obtained the easily-adhesive polyester film. Water 38.63 parts by mass Isopropanol 37.42 parts by mass Silica sol 1.21 parts by mass (Silica sol with an average particle diameter of 40nm and a solid content concentration of 40% by mass) Silica sol 1.11 parts by mass (Silica sol with an average particle diameter of 450nm and a solid content concentration of 4% by mass) Resin A solution 14.30 parts by mass (solid content concentration 25% by mass) Crosslinking agent P solution 6.74 parts by mass (solid content concentration 40% by mass) Surfactant 0.25 parts by mass (Fluorine-based, solid content concentration 10% by mass) High boiling point solvent 0.34 parts by mass

Evaluation of the obtained easily-adhesive polyester film was carried out in the same manner as in Example 1, and the results are shown in Table 1.

(comparative example 4) Except having prepared the coating liquid of the composition mentioned below, it carried out similarly to Example 1, and obtained the easily-adhesive polyester film. Water 35.06 parts by mass Isopropanol 37.42 parts by mass Silica sol 1.21 parts by mass (Silica sol with an average particle diameter of 40nm and a solid content concentration of 40% by mass) Silica sol 1.11 parts by mass (Silica sol with an average particle diameter of 450nm and a solid content concentration of 4% by mass) Resin A solution 23.83 parts by mass (solid content concentration 25% by mass) Crosslinking agent P solution 0.78 parts by mass (solid content concentration 40% by mass) Surfactant 0.25 parts by mass (Fluorine-based, solid content concentration 10% by mass) High boiling point solvent 0.34 parts by mass

Evaluation of the obtained easily-adhesive polyester film was carried out in the same manner as in Example 1, and the results are shown in Table 1.

(comparative example 5) Except having prepared the coating liquid using the resin D solution, it carried out similarly to Example 1, and obtained the easy-adhesive polyester film. Evaluation of the obtained easily-adhesive polyester film was carried out in the same manner as in Example 1, and the results are shown in Table 1.

(comparative example 6) Except having prepared the coating liquid of the composition mentioned below, it carried out similarly to Example 1, and obtained the easily-adhesive polyester film. Water 36.80 parts by mass Isopropanol 37.29 parts by mass Silica sol 1.33 parts by mass (Silica sol with an average particle diameter of 40nm and a solid content concentration of 40% by mass) Silica sol 1.23 parts by mass (Silica sol with an average particle diameter of 450nm and a solid content concentration of 4% by mass) Resin A solution 13.31 parts by mass (solid content concentration 25% by mass) Resin E solution 5.99 parts by mass (solid content concentration 37% by mass) Crosslinking agent P solution 3.47 parts by mass (solid content concentration 40% by mass) Surfactant 0.25 parts by mass (Fluorine-based, solid content concentration 10% by mass) High boiling point solvent 0.34 parts by mass

Evaluation of the obtained easily-adhesive polyester film was carried out in the same manner as in Example 1, and the results are shown in Table 1.

(comparative example 7) Except having prepared the coating liquid using the crosslinking agent T solution, it carried out similarly to Example 1, and obtained the easily-adhesive polyester film. Evaluation of the obtained easily-adhesive polyester film was carried out in the same manner as in Example 1, and the results are shown in Table 1.

[Table 1] Resin (Water Dispersion) crosslinking agent Composition ratio (mass%) particle Surface free energy γ _s (mN/m) Coating layer thickness (nm) Fog value (%) A _N X (at%) t ₁ (seconds) t ₂ (seconds) (t ₂ /t ₁ ) ×100 Adhesiveness (%) Tightness reliability resin crosslinking agent After film X Y after wet heat treatment X Y Z Example 1 A P 80 20 silicon dioxide 46.3 80 0.72 8.6 111 65 59 100 100 0 100 ◎ Example 2 A P 80 20 silicon dioxide 46.8 40 0.36 8.7 63 32 51 100 99 1 100 ◎ Example 3 A P 80 20 silicon dioxide 46.2 180 0.99 8.6 141 78 55 100 100 0 100 ◎ Example 4 A P 89 11 silicon dioxide 48.1 75 0.74 8.6 66 27 41 100 100 0 100 ◎ Example 5 A P 70 30 silicon dioxide 44.3 83 0.70 8.8 183 78 43 100 100 0 100 ◎ Example 6 A Q 80 20 silicon dioxide 45.2 81 0.69 8.7 125 60 48 100 99 1 99 ◎ Example 7 A R 80 20 silicon dioxide 46.8 77 0.80 8.4 122 74 61 99 98 1 97 ○ Example 8 A S 80 20 silicon dioxide 47.2 72 0.66 4.3 138 65 47 99 96 3 98 ○ Example 9 B P 80 20 silicon dioxide 46.3 76 0.73 8.8 119 53 45 100 99 1 99 ◎ Example 10 C P 80 20 silicon dioxide 45.9 88 0.73 5.2 123 63 51 99 97 2 97 ○ Example 11 A P 80 20 Zirconia/SiO2 46.1 75 0.74 8.7 128 60 47 100 100 0 100 ◎ Example 12 A P 80 20 Titanium oxide/silicon dioxide 46.8 86 0.76 8.6 121 64 53 100 100 0 100 ◎ Example 13 A P 80 20 Zirconia/Titanium Oxide/Silicon Dioxide 46.9 85 0.74 8.7 120 68 57 100 100 0 100 ◎ Comparative example 1 A P 80 20 silicon dioxide 47.0 250 1.41 8.8 405 155 38 83 0 83 30 x Comparative example 2 A P 80 20 silicon dioxide 46.3 25 0.20 8.3 43 15 35 30 0 30 0 x Comparative example 3 A P 57 43 silicon dioxide 40.4 88 0.73 11.0 240 82 34 100 0 100 60 x Comparative example 4 A P 95 5 silicon dioxide 50.9 84 0.79 7.3 48 18 38 87 0 87 20 x Comparative Example 5 D. P 80 20 silicon dioxide 41.0 77 0.72 2.3 135 44 33 90 0 90 18 x Comparative Example 6 E/A P 80 20 silicon dioxide 38.6 75 0.70 7.0 125 36 29 100 0 100 5 x Comparative Example 7 A T 80 20 silicon dioxide 42.3 86 0.71 8.3 163 52 32 98 0 98 twenty three x Composition ratio (mass %) is represented by the percentage of each solid content mass of resin and crosslinking agent with respect to the total solid content mass of resin and crosslinking agent. [Possibility of industrial use]

According to the present invention, it is possible to provide an easily-adhesive polyester film whose adhesion reliability is ensured after being left in a high-temperature and high-humidity environment for a long time, and the application to optical applications and the like becomes easier.

A _N X: The maximum value of the nitrogen atomic ratio (at%) A _N Y: The lower limit of the nitrogen atomic ratio (at%) A _N Z: The middle value of the nitrogen atomic ratio equivalent to the middle of A _N X and A _N Y (at%) t ₁ : Etching time when nitrogen atomic ratio reaches the lower limit (seconds) t ₂ : Etching time corresponding to A _N Z (seconds) t _1-1 , t _1-2 , t _{1- 3} : Etching time for 3 consecutive points (seconds)

Fig. 1 is an example of a nitrogen element distribution curve measured by etching from the surface of the ESCA coating layer to the depth direction of the easily-adhesive polyester film of the present invention. Fig. 2 is an example of a nitrogen element distribution curve of the easily-adhesive polyester film of Example 1 based on the element distribution measurement by etching from the surface of the coating layer of ESCA to the depth direction.

none.

Claims (4)

An easily-adhesive polyester film, which is an easily-adhesive polyester film having a coating layer formed by hardening a composition on at least one side of the polyester film, the composition containing polyester having a polycyclic aromatic skeleton, and a crosslinking agent having at least one skeleton selected from aliphatic, alicyclic, and heterocyclic groups, wherein the thickness (d: nm) of the coating layer satisfies the following formula (1), and the thickness of the coating layer The surface free energy (γ _s : mN/m) of the surface of the coating layer in contact with the polyester film satisfies the following formula (2), and the nitrogen atomic ratio (A _N : at %) satisfies the following formula (3), in the _nitrogen element distribution curve measured from the element distribution in the depth direction, the time t ₁ ( seconds), the ratio of the time t ₂ (seconds) at which the ratio of nitrogen atoms becomes the maximum (A _N X: at%) to the median value of A _N Y (A _N Z: at%) (t ₂ /t ₁ ) satisfy the following formula (4), 30 ≦ d ≦ 200 ... formula (1) 43 ≦ γ _s ≦ 49 ... formula (2) 3.0 ≦ A _N ≦ 9.5 ... formula (3) (t ₂ /t ₁ ) × 100 ≧ 40 ...Formula (4). The easily-adhesive polyester film according to claim 1, wherein the adhesiveness X (%) when a hard coat layer is provided on the coating layer after film formation is 95% or more, The adhesiveness X and the adhesiveness Y (%) when a hard coat layer is provided on the coating layer after being left in an environment of 80° C. and 90% RH for 24 hours satisfy the following formula (5), X-Y(%) ≦ 5 ...Formula (5). The easily adhesive polyester film according to claim 1 or 2, wherein the polyester having a polycyclic aromatic skeleton is a polyester having a naphthalene skeleton. The easily bondable polyester film according to any one of claims 1 to 3, wherein the crosslinking agent having at least one skeleton selected from aliphatic, alicyclic, and heterocyclic is a crosslinking agent having at least one skeleton selected from aliphatic, aliphatic An isocyanate crosslinking agent with at least one skeleton selected from ring and heterocycle groups.

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