JP6521264B2 - Laminated polyester film - Google Patents

Description

  The present invention relates to an easily-adhesive polyester film which can ensure low interference which can solve the problem of rainbow unevenness and is excellent in transparency. More particularly, the present invention relates to an easily adhering polyester film which can be suitably used even in high definition optical applications with less fine scratches.

  A hard coat film in which a transparent hard coat layer is laminated is used on the front face of a touch panel, a computer, a television, a display such as a liquid crystal display, a decorative material and the like. Moreover, a transparent polyester film is generally used as the transparent plastic film of the base material, and in order to improve the adhesion between the polyester film of the base material and the hard coat layer, easy adhesion as an intermediate layer thereof is provided. In many cases, an applied layer is provided.

  The above-mentioned hard coat film is required to be resistant to temperature, humidity and light, transparency, chemical resistance, scratch resistance, antifouling property and the like. Moreover, since it is used for surfaces, such as a display and a decoration material, in many cases, visibility and the designability are requested | required. Therefore, in order to suppress glare and iris color due to reflected light when viewed from an arbitrary angle, the anti-reflection of a multilayer structure in which a high refractive index layer and a low refractive index layer are mutually laminated on the hard coat layer It is common practice to provide layers.

  However, in applications such as displays and decorative materials, further increases in screen size (larger area) and higher definition are required in recent years, and along with this, there is a demand for suppression of iris-like color (interference spots) under fluorescent lamps in particular. The level is getting higher. In addition, three-wave fluorescent lamps have become mainstream because of the reproducibility of daylight colors, and interference spots are more easily produced. Furthermore, the cost reduction request | requirement by simplification of a reflection prevention layer is also high. Therefore, what is desired is to suppress the interference spots as much as possible with only the hard coat film to which the antireflection layer is not added.

  The iris-like color (interference spots) of the hard coat film is the refractive index of the polyester film of the base material (for example, 1.62-1.65) and the refractive index of the hard coat layer made of acrylic resin or the like (for example 1.49) It is said that it occurs because the difference between In order to reduce the difference in refractive index between laminations and prevent the occurrence of interference spots, a coated layer is provided on the polyester film of the base material, the refractive index difference between the polyester film and the coated layer, the refraction of the coated layer and the hard coat layer The method of controlling the refractive index of a coating layer by content of resin which comprises a coating layer, and a high refractive index additive so that a rate difference may be made small is disclosed.

  Conventionally, in the field of easily adhesive films for optics, there has been known a technique for reducing rainbow unevenness by including specific fine particles in the easily adhesive layer (see, for example, Patent Document 1). However, such conventional techniques are considered to have achieved certain results in terms of adhesion and rainbow unevenness suppression, but there is a problem of susceptibility to scratching due to poor slipperiness, and thus the slipperiness is enhanced. When other particles are added to the glass, the transparency is lowered, and there is a problem that the slipperiness and transparency, and the low interference property for reducing rainbow unevenness can not be balanced.

JP 2007-203712 A

  The development of mobile technology is expanding the use of mobile devices such as mobile phones, car navigation and e-books in the outdoor area. In addition, the portable device is mostly a display with a liquid crystal panel in terms of thinning. In such a field, for example, in a mobile phone equipped with a touch panel, as a hard coat film for protecting the surface of a display, it is designed on the back of the hard coat film such as interference fringes by reflected light of both interfaces in contact with the coated surface In applications where the properties are applied, the defects of visibility due to interference fringes are becoming more pronounced.

  However, when a large amount of a high refractive index additive is added in order to obtain high low interference, the transparency is impaired and there are cases where low interference and transparency can not be simultaneously achieved. In addition, since there are applications for use in high-definition displays, it has been found that transparency can not be maintained even if slip properties are improved by adding a lubricant in order to suppress scratches.

  Furthermore, as the speed of post-processing such as lamination of hard coat layer and slit processing advances for the improvement of productivity in recent years, strong friction is added to the coated layer, and scratching of the coated layer which has not been a problem in the past Thickness variations and quality variations are becoming issues. In particular, since the resin used to increase the refractive index is relatively high in hardness and brittle, the scratch resistance of the coating layer tends to increase as the coating layer suppresses interference spots.

  Therefore, an optically easy-adhesive polyester film having transparency and a high adhesion to a hard coat layer is desired, while having an effect of suppressing interference spots and without damaging the coating layer even at high speed processing.

  The present invention has been made on the background of the problems of the prior art. That is, the object of the present invention is to achieve excellent balance of characteristics such as slipperiness and transparency, excellent handleability in post-process such as manufacturing process and polarizing plate manufacturing process of liquid crystal display device, less scratching, rainbow unevenness An object of the present invention is to provide an easily adhesive polyester film which can be suitably used in optical applications which is also excellent in low interference for suppression.

As a result of intensive investigations to achieve such an object, the present inventor has completed the present invention. That is, the present invention has the following constitution.
1. It is a polyester film having a coating layer on at least one side, wherein the polyester film is a polyester film having at least one of polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate as a component, and the coating layer is A highly adhesive polyester film comprising zirconia / titania mixed particles A, lubricant particles B, and a binder resin, wherein the content ratio of zirconia to the total mass of zirconia and titania in the zirconia / titania mixed particles A is 55 to 90% by mass.
2. The easily adhesive polyester film as described in the above first, wherein the lubricant particles B have an average particle diameter of 200 nm or more.
3. The easily adhesive polyester film as described in the first or the second, wherein the average particle diameter of the zirconia / titania mixed particle A is 5 to 200 nm.
4. The easily adhesive polyester film according to any one of the above-mentioned first to third, wherein the content of the lubricant particles B with respect to the solid content of the coating layer is 0.1 to 20% by mass.
5. The easily adhesive polyester film according to any one of the first to fourth above, wherein the content of the zirconia / titania mixed particle A with respect to the solid content of the coating layer is 2 to 50% by mass.
6. It is selected from the group consisting of a hard coat layer, an antiglare layer, an antiglare antireflective layer, an antireflective layer, and a low reflective layer on the coated layer of the easily adhesive polyester film according to any one of the first to fifth aspects. Laminated polyester film having one or more functional layers.

  According to the present invention, low interference which can suppress rainbow unevenness can be secured, the balance between transparency and slipperiness is excellent, scratching is small, and handling in post processes such as manufacturing and polarizing plate manufacturing processes of liquid crystal display devices It has become possible to provide an easily adhering polyester film that can be suitably used in optical applications with excellent properties.

(Polyester film)
The polyester film used as a base material in the present invention is a film composed of a polyester resin, and is preferably a polyester film mainly composed of at least one of polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate and polyethylene naphthalate . In addition, it may be a film in which the third component monomer is a copolymerized polyester in the polyester as described above. Among these polyester films, polyethylene terephthalate films are most preferable in terms of the balance between physical properties and cost.

  The polyester film may be a single layer or multiple layers. In addition, various additives can be contained in the polyester resin, if necessary, in each of these layers, as long as the effects of the present invention can be obtained. Examples of the additive include an antioxidant, a light resistant agent, an antigelling agent, an organic wetting agent, an antistatic agent, an ultraviolet light absorber, a surfactant and the like.

(Coated layer)
The easily adhesive polyester film of the present invention is obtained by laminating an easily adhesive coated layer on a polyester base film as described above. The coating layer contains zirconia / titania mixed particles A (hereinafter sometimes simply referred to as particles A), lubricant particles B (hereinafter sometimes simply referred to as particles B), and a binder resin.

  The particles A are zirconia / titania mixed particles. The mixed particles referred to in the present invention are a particle group including both zirconia and titania in an aggregate state in which zirconia and titania are respectively dispersed alone in a single liquid and do not form a complex. Of course, in the coating layer, the liquid component is hardly evaporated in the drying step and the curing step. When the coating layer contains such particles A, the balance between the slipperiness and the transparency is excellent, and the high transparency and the low interference can be ensured. The liquid is preferably a water-based liquid in order to facilitate formation of a coating layer by the so-called in-line coating method described later.

  The particle A may contain other components other than zirconia / titania, and may be inorganic particles or organic particles, and is not particularly limited, but silica, dioxide Examples of such inorganic particles include metal oxides such as titanium, zirconium oxide, talc and kaolinite, and inorganic particles inert to polyester such as calcium carbonate, calcium phosphate and barium sulfate.

  The ratio of the total mass of zirconia and titania to the mass of particles A (not including the mass of liquid), which is mixed particles, is preferably 70% by mass or more, more preferably 80% by mass or more, and still more preferably 90% by mass. % Or more. Of course, it may be 100% by mass. If the ratio of the total mass of zirconia and titania in the particle A is 70% by mass or more, the slipperiness and transparency are preferably balanced.

  The ratio of the mass of zirconia to the total mass of zirconia and titania constituting particle A which is a mixed particle is preferably 10% by mass or more, more preferably 20% by mass or more, still more preferably 30% by mass or more It is particularly preferably 40% by mass or more, still more preferably 50% by mass or more, and most preferably 55% by mass or more. When the ratio of the mass of zirconia to the total mass of zirconia and titania is 10% by mass or more, the surface roughness does not become too large, the slipperiness with the guide roll becomes appropriate, and the film is not easily damaged. Therefore, the haze does not increase and the transparency is excellent.

  The ratio of the mass of zirconia to the total mass of zirconia and titania constituting particle A is preferably 90% by mass or less, more preferably 85% by mass or less, and still more preferably 80% by mass or less. Preferably it is 77 mass% or less. If the ratio of the mass of zirconia to the total mass of zirconia and titania is 90% by mass or less, the surface roughness does not become too small, appropriate slipperiness is maintained, and the handling property is good, and unwinding Sometimes it is hard to get hurt and is preferable.

  The ratio of the mass of titania to the total mass of zirconia and titania constituting particle A is preferably 10% by mass or more, more preferably 15% by mass or more, still more preferably 20% by mass or more, and particularly preferably 23% by mass % Or more. When the ratio of the mass of titania to the total mass of zirconia and titania is 10% by mass or more, the slipperiness is improved, the handling is improved, and the scratch resistance is improved, which is preferable. However, increasing the ratio of the mass of titania to the total mass of zirconia and titania means that the ratio of the mass of zirconia decreases, so it is preferably 90 mass% or less, more preferably 80 mass%. Or less, more preferably 70% by mass or less, particularly preferably 60% by mass or less, still more preferably 50% by mass or less, and most preferably 45% by mass or less.

  The average particle diameter of the particles A is preferably 5 nm or more, more preferably 10 nm or more, still more preferably 15 nm or more, and particularly preferably 20 nm or more. When the average particle diameter of the particles A is 5 nm or more, aggregation is difficult, which is preferable.

  The average particle diameter of the particles A is preferably 200 nm or less, more preferably 150 nm or less, still more preferably 100 nm or less, and particularly preferably 60 nm or less. The average particle diameter of the particles A is preferably 200 nm or less because of good transparency.

  The particles B are (1) silica, kaolinite, talc, light calcium carbonate, calcium carbonate carbonate, zeolite, alumina, barium sulfate, carbon black, zinc oxide, zinc sulfate, zinc carbonate, titanium dioxide, titanium dioxide, satin white, aluminum silicate Inorganic particles such as diatomaceous earth, calcium silicate, aluminum hydroxide, hydrolyzate halloysite, magnesium carbonate, magnesium hydroxide, etc., (2) acrylic or methacrylic, vinyl chloride, vinyl acetate, nylon, styrene / acrylic, Styrene / butadiene type, polystyrene / acrylic type, polystyrene / isoprene type, polystyrene / isoprene type, methyl methacrylate / butyl methacrylate type, melamine type, polycarbonate type, urea type, epoxy type, urethane type, phenol type Diallyl phthalate, but include organic particles of polyester or the like, to give an appropriate sliding property to the coating layer, silica is particularly preferably used.

  The average particle diameter of the particles B is preferably 200 nm or more, more preferably 250 nm or more, still more preferably 300 nm or more, and particularly preferably 350 nm or more. When the average particle diameter of the particles B is 200 nm or more, aggregation is difficult and slipperiness can be secured, which is preferable.

The average particle diameter of the particles B is preferably 2000 nm or less, more preferably 1500 nm or less , still more preferably 1000 nm or less , and particularly preferably 700 nm or less . Transparency is maintained as the average particle diameter of particle | grains B is 2000 nm or less, and it is preferable, without particle | grains falling off.

  Surface treatment of particles A and B may be performed, and there are physical surface treatment such as plasma discharge treatment and corona discharge treatment and chemical surface treatment using a coupling agent as a surface treatment method, but the coupling agent The use of is preferred. As a coupling agent, organoalkoxy metal compounds (eg, titanium coupling agent, silane coupling agent) are preferably used. When the particles B are silica, silane coupling treatment is particularly effective. It may be used as a surface treatment agent for the particles B in advance for surface treatment prior to preparation of the layer coating solution, or may be added as an additive at the time of preparation of the layer coating solution and contained in the layer. Of course, it may be used for particle A.

  The binder resin constituting the coating layer is not particularly limited as long as it is a resin that provides easy adhesion. Specific examples of the polymer include polyester resin, acrylic resin, urethane resin, polyvinyl resin (polyvinyl alcohol etc.), and polyalkylene. Examples include glycol, polyalkyleneimine, methylcellulose, hydroxycellulose, starches and the like. Among these, it is preferable to use a polyester resin, an acrylic resin, or a urethane resin from the viewpoint of retention of particles and adhesion. Also, in consideration of familiarity with the polyester film, polyester resin is most suitable. These binder resins may be used in combination.

  The polyester resin may be 100% by mass in the total solid components in the coating layer, but it is preferable to contain 10% by mass or more and 90% by mass or less. More preferably, it is 20% by mass to 80% by mass. When the content of the polyester resin is 90% by mass or less, adhesion with the hard coat layer under high temperature and high humidity is maintained, which is preferable. On the contrary, adhesiveness with the polyester film under normal temperature, high temperature, high humidity is maintained by presence of other urethane resins etc. as content is 10 mass% or more, and it is preferable.

  In the present invention, in order to form a crosslinked structure in the coating layer, the coating layer may be formed to contain a crosslinking agent. By including the crosslinking agent, it is possible to further improve the adhesion under high temperature and high humidity. Specific examples of the crosslinking agent include ureas, epoxys, melamines, isocyanates, oxazolines, carbodiimides, and the like. Among these, melamine type, isocyanate type, oxazoline type and carbodiimide type crosslinking agents are preferable from the viewpoint of the temporal stability of the coating liquid and the adhesion improvement effect under high temperature and high humidity treatment. Moreover, in order to accelerate | stimulate a crosslinking reaction, a catalyst etc. can be used suitably as needed.

  As content in the application layer of a crosslinking agent, 5 mass% or more and 50 mass% or less are preferable in all the solid components. More preferably, they are 10 mass% or more and 40 mass% or less. If it is 10 mass% or more, the strength of the resin of the coating layer is maintained, the adhesion under high temperature and high humidity is good, and if it is 40 mass% or less, the flexibility of the resin of the coating layer is held. Adhesiveness at normal temperature, high temperature and high humidity is maintained, which is preferable.

  The content of the particles A in the coating layer is preferably 2% by mass or more, more preferably 3% by mass or more, still more preferably 4% by mass or more, and particularly preferably 5% by mass or more. When the content of the particles A in the coating layer is 2% by mass or more, the refractive index of the coating layer can be kept high, and low interference is preferably obtained.

  The content of particles A in the coating layer is preferably 50% by mass or less, more preferably 40% by mass or less, still more preferably 30% by mass or less, and particularly preferably 20% by mass or less. Film forming property is maintained as particle | grain A content in a coating layer is 50 mass% or less, and it is preferable.

  The particle B content in the coating layer is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and still more preferably 1% by mass or more. When the particle B content in the coating layer is 0.1% by mass or more, it is preferable because the appropriate slipperiness is maintained.

  The content of particles B in the coating layer is preferably 20% by mass or less, more preferably 15% by mass or less, and still more preferably 10% by mass or less. When the particle B content in the coating layer is 20% by mass or less, the haze is kept low, which is preferable from the viewpoint of transparency.

  The thickness of the coating layer is preferably 0.001 μm or more, more preferably 0.01 μm or more, still more preferably 0.02 μm or more, and particularly preferably 0.05 μm or more. Adhesiveness is favorable for the film thickness of a coating layer to be 0.001 micrometer or more, and preferable.

  The thickness of the coating layer is preferably 2 μm or less, more preferably 1 μm or less, still more preferably 0.8 μm or less, and particularly preferably 0.5 μm or less. When the film thickness of the coating layer is 2 μm or less, there is no possibility that blocking will occur, which is preferable.

  The coating layer can also contain a surfactant for the purpose of improving the leveling properties at the time of coating and degassing the coating solution. The surfactant may be any of cationic, anionic and nonionic surfactants, but is preferably silicone, acetylene glycol or fluorosurfactant. These surfactants are preferably contained in the coating layer in such a range that the effect of suppressing iris color under fluorescent light and the adhesion are not impaired.

  In order to impart other functionality to the coating layer, various additives may be contained within a range that does not impair the effect of suppressing iris-like color under a fluorescent lamp or the adhesion. Examples of the additive include fluorescent dyes, fluorescent whitening agents, plasticizers, ultraviolet light absorbers, pigment dispersants, foam inhibitors, antifoaming agents, preservatives and the like.

  As a coating method, any of a so-called in-line coating method in which the polyester base film is simultaneously formed and a so-called off-line coating method in which the polyester base film is separately formed by a film formation can be applied. In-line coating methods are efficient and more preferred.

  As a coating method, any known method can be used as a method for applying a coating solution to a polyethylene terephthalate (hereinafter abbreviated as PET) film. For example, reverse roll coating method, gravure coating method, kiss coating method, die coating method, roll brush method, spray coating method, air knife coating method, wire bar coating method, pipe doctor method, pipe coating method, impregnation coating method, curtain coating method, etc. are mentioned. Be These methods are applied singly or in combination.

  In the present invention, as a method of providing a coating layer on a polyester film, there may be mentioned a method of applying a coating solution containing a solvent, particles and a resin to a polyester film and drying it. Examples of the solvent include an organic solvent such as toluene, water, or a mixed system of water and a water-soluble organic solvent, preferably water alone or a mixture of water and a water-soluble organic solvent from the viewpoint of environmental problems. preferable.

  The solid content concentration of the coating liquid depends on the type of binder resin, the type of solvent, and the like, but is preferably 2% by mass or more, and more preferably 4% by mass. It is preferable that solid content concentration of a coating liquid is 35 mass% or less, More preferably, it is 15 mass% or less.

  The drying temperature after application also depends on the type of binder resin, the type of solvent, the presence or absence of a crosslinking agent, the solid content concentration, etc., but is preferably 80 ° C. or higher, and preferably 250 ° C. or lower.

  The surface roughness (Ra) of the coating layer is related to the slipperiness of the surface of the coating layer and the like, and is preferably 0.01 nm or more, more preferably 0.1 nm or more, and still more preferably 0.2 nm or more And particularly preferably 0.5 nm or more. On the other hand, the upper limit of the surface roughness (Ra) of the coating layer is preferably 200 nm or less, more preferably 100 nm or less, still more preferably 80 nm or less, and particularly preferably 50 nm or less.

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

  The polyester film of the present invention may be a uniaxially stretched film or a biaxially stretched film, but when the biaxially stretched film is used as a protective film on the front surface of the liquid crystal panel, it is observed from directly above the film surface. Even if rainbow color spots are not seen, however, it is necessary to be careful because rainbow color spots may be observed when observed from an oblique direction.

  In this phenomenon, a biaxially stretched film is composed of a refractive index ellipsoid having different refractive indexes in the traveling direction, width direction, and thickness direction, and the retardation becomes zero due to the light transmission direction inside the film (refractive index ellipse This is because the body looks like a perfect circle) direction. Therefore, when the liquid crystal display screen is observed from a specific direction in the oblique direction, a point where retardation is zero may occur, and rainbow color spots may occur concentrically around that point. Then, assuming that the angle from just above the film surface (normal direction) to the position where the rainbow color spots are visible is θ, this angle θ becomes larger as the birefringence in the film surface is larger, and the rainbow color is The spots become less visible. In the biaxially stretched film, the angle θ tends to be small, so the uniaxial stretched film is more difficult to see rainbow color spots, which is preferable.

  However, a completely uniaxial (uniaxially symmetric) film is not preferable because the mechanical strength in the direction orthogonal to the orientation direction is significantly reduced. The present invention has biaxiality (biaxial symmetry) in a range in which rainbow color spots are not substantially generated, or in a range in which rainbow color spots are not generated in a viewing angle range required for a liquid crystal display screen. Is preferred.

(Laminated polyester film)
The laminated polyester film mainly used for optical applications according to the present invention is a hard coat layer comprising an electron beam or an ultraviolet curable acrylic resin or a siloxane-based thermosetting resin on the coated layer of the easily adhesive polyester film of the present invention. It can be obtained by providing

  It is also a preferred embodiment to provide a functional layer on the coated layer of the easily adhesive polyester film of the present invention. In addition to the hard coat layer described above, the functional layer is an antiglare layer, an antiglare antireflective layer, an antireflective layer, a low reflective layer, and the like for the purpose of preventing reflection, suppressing glare, suppressing rainbow unevenness, and suppressing scratches. It refers to a layer having functionality such as an antistatic layer. As the functional layer, various types known in the art can be used, and the type is not particularly limited. Each functional layer will be described below.

  For example, a known hard coat layer can be used for the formation of the hard coat layer, and there is no particular limitation, but polymerization is carried out by irradiation of drying, heat, chemical reaction, or electron beam, radiation, or ultraviolet light, Resin compounds that react and / or react can be used. Examples of such a curable resin include melamine-based, acrylic-based, silicone-based, and polyvinyl alcohol-based curable resins. However, a photocurable acrylic-based resin having high surface hardness or optical design can be used. Resins are preferred. As such an acrylic curable resin, a polyfunctional (meth) acrylate based monomer or an acrylate based oligomer can be used, and examples of the acrylate based oligomer include polyester acrylate based, epoxy acrylate based, urethane acrylate based, poly Ether acrylates, polybutadiene acrylates, silicone acrylates, etc. may be mentioned. A coating composition for forming the optical functional layer can be obtained by mixing a reactive diluent, a photopolymerization initiator, a sensitizer and the like with these acrylic curable resins.

  The above hard coat layer may have an antiglare function (anti-glare function) for scattering external light. The antiglare function (antiglare function) is obtained by forming asperities on the surface of the hard coat layer. At this time, ideally, the haze of the film is preferably 0 to 50%, more preferably 0 to 40%, and particularly preferably 0 to 30%. Of course, 0% is ideal, and may be 0.2% or more, or 0.5% or more.

  Therefore, the application of the film of the present invention mainly covers the whole of the optical film, and it is a prism lens sheet, AR (antireflection) film, hard coat film, diffusion plate, optical film such as shatterproof film, flat TV, CRT It can be suitably used as a base film of a member for a member, a near infrared absorption filter which is a member on a front plate for a plasma display, a transparent conductive film such as a touch panel or electroluminescence, and the like.

  More specifically, an acrylic resin curable by electron beam or ultraviolet light for forming the above hard coat layer is one having an acrylate functional group, and, for example, polyester resin, polyether resin, acrylic resin of relatively low molecular weight. Oligomers or prepolymers such as (meth) acrylates of polyfunctional compounds such as epoxy resins, urethane resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiol polyene resins and polyhydric alcohols, and ethyl (meth) as a reactive diluent Monofunctional monomers such as acrylates, ethylhexyl (meth) acrylates, styrene, methylstyrene, N-vinylpyrrolidone and polyfunctional monomers, such as trimethylolpropane tri (meth) acrylate, hexanediol (meth) acrylate Rate, tripropylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol Those containing di (meth) acrylate or the like can be used.

  However, in the case of an electron beam or ultraviolet curable resin, acetophenones, benzophenones, Michler's benzoyl benzoate, α-amyloxime ester, tetramethylthyraum monosulfide, thioxanthone as a photopolymerization initiator in the above-mentioned resin And photosensitizers such as n-butylamine, triethylamine, tri-n-butylphosphine and the like can be used as a mixture.

  The silicone-based (siloxane-based) thermosetting resin can be produced by hydrolysis and condensation reaction of an organosilane compound singly or in combination of two or more species under an acid or base catalyst. In particular, in the case of low reflection, it is better to mix one or more fluorosilane compounds and to cause hydrolysis and condensation reaction, in order to improve low refractive index and contamination resistance.

(Production of laminated polyester film)
The method for producing a laminated polyester film in the present invention will be described by way of an easily adhesive polyester film as an example, but of course it is not limited thereto.

  The electron beam or ultraviolet curable acrylic resin or siloxane-based thermosetting resin is applied to the surface of the coating layer of the above-mentioned easily adhesive polyester film. When the coating layer is provided on both sides, it is applied to at least one of the coating layer surfaces. The coating solution is not particularly required to be diluted, but there is no particular problem if it is diluted with an organic solvent according to the viscosity of the coating solution, the wettability, the thickness of the coating film, etc. The coating layer is applied to the above-mentioned film and dried if necessary, and then the coating layer is cured by electron beam or ultraviolet irradiation and heating according to the curing conditions of the coating liquid. , 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 effect on the chemical resistance, the abrasion resistance, the antifouling property and the like as the hard coat layer is preferably exhibited because it is efficiently exhibited. On the other hand, when the thickness is 15 μm or less, the flexibility of the hard coat layer is maintained, and there is no possibility of cracking or the like, which is preferable.

  As the scratch resistance, it is preferable that when the coated surface is worn with a black backing, the scratch is not noticeable visually. If scratches are not noticeable in the above evaluation, it is difficult to be scratched when passing the guide roll, which is preferable from the viewpoint of handling property and the like.

  The lower limit of the coefficient of static friction (μs) is preferably 0.3, and if it is 0.3 or more, the problem of excessive slippage does not occur, so that rolling up with a hard chromium plated roll or the like becomes easy in the manufacturing process. Handling property and blocking resistance are maintained, which is preferable. The upper limit of the static friction coefficient (μs) is preferably 0.5, and 0.5 or less is preferable because there is no risk of scratching the film to be a contact counterpart surface during winding.

  The lower limit of the dynamic friction coefficient (μd) is preferably 0.4, and if it is 0.4 or more, the problem of excessive slippage does not occur, so that rolling up with a hard chromium plated roll or the like becomes easy in the manufacturing process. Handling property and blocking resistance are maintained, which is preferable. The upper limit of the dynamic friction coefficient (μd) is preferably 0.6, and it is preferable that the film be 0.6 or less without damaging the film to be a contact opposite surface during winding.

  Since the polyester film of the present invention is mainly used as an easily adhesive film for optics, it is preferable to have high transparency. The lower limit of the haze is ideally 0%, and the closer to 0%, the more preferable. The upper limit of the haze is preferably 2%, and the light transmittance is preferably 2% or less, which is preferable because a clear image can be obtained in a liquid crystal display device. The haze of the polyester film can be measured, for example, according to the method described later.

  The lower limit of the adhesion between the easily adhesive layer-coated layer and the hard coat layer is preferably 80%, and the upper limit is preferably 100%, as evaluated by the measurement method described later. If it is 80% or more, it can be said that the adhesion between the coating layer and the hard coat layer is sufficiently maintained.

  The lower limit of the adhesion between the easily adhesive layer and the hard coat layer evaluated according to the method described later under high temperature and high humidity conditions is preferably 10%, and the upper limit of high temperature and high humidity adhesion is preferably 100%. is there. If it is 10% or more, the adhesion between the easy adhesion layer and the hard coat layer is generally satisfied under high temperature and high humidity conditions, and the passability in the post-processing step is satisfied as a whole. More preferably, it is 50% or more.

  It is preferable that the polyester film for polarizer protection which formed the hard coat can not confirm the interference spots by the below-mentioned evaluation method, and if the interference spots by the said evaluation method can not be checked, the visibility of a liquid crystal picture device becomes good. preferable.

  The easily adhesive polyester film of the present invention can be used for various applications, but is preferably used in the process of manufacturing a polarizing plate used in a liquid crystal display device, and is particularly preferably used as a protective film of a polarizer constituting the polarizing plate. It is In general, many polarizers are made of polyvinyl alcohol, and the easily-adhesive polyester film of the present invention is adhered using a polyvinyl alcohol or an adhesive to which a crosslinking agent is added, if necessary. At that time, it is more preferable to use the coated layer of the easily adhesive polyester film of the present invention not to the side to be bonded to the polarizer but to the opposite side. The surface of the easily adhesive polyester film of the present invention to be adhered to the polarizer includes, for example, an polyester resin, a polyvinyl alcohol resin and a crosslinking agent as described in WO 2012/105607. Preferably, the layers are laminated.

Next, the present invention will be described in detail using Examples, Comparative Examples, and Reference Examples, but the present invention is naturally not limited to the following Examples. In addition, the following Examples 2 and 3 shall be read as Reference Examples 2 and 3, respectively. Moreover, the evaluation method used by this invention is as follows.

(1) Average particle size [Measuring method by scanning electron microscope]
The measurement of the average particle diameter of the above-mentioned particles can be carried out by the following method. Take a picture of the particles with a scanning electron microscope (SEM), and at a magnification such that the size of one of the smallest particles is 2 to 5 mm, the largest diameter of 300 to 500 particles ( Measure the distance), and let the average value be the average particle size. The average particle diameter of the particles present in the coating layer in the present invention can be measured by the measurement method.

[Dynamic light scattering method]
The mean particle size of the particles can also be determined by dynamic scattering when producing particles or films. The sol was diluted with a dispersion medium, measured with a submicron particle analyzer N4 PLUS (manufactured by Beckman Coulter, Inc.) using the parameters of the dispersion medium, and calculated by the cumulant method to obtain an average particle size. In the dynamic light scattering method, the average particle size of particles in the sol is observed, and when there is aggregation between particles, the average particle size of those aggregated particles is observed.

(2) particle refractive index
The refractive index of the particles can be measured by the following method. After the inorganic particles are dried at 150 ° C., the ground powder is immersed in a solvent 1 (having a refractive index lower than that of the particles), and then the solvent 2 (having a higher refractive index than the particles) is little by little. Was added until. The refractive index of this solution was measured using an Abbe's refractometer (Abbé refractometer manufactured by Atago Co., Ltd.). The measurement was performed at 23 ° C. and D line (wavelength 589 nm). The solvent 1 and the solvent 2 are selected to be miscible with each other, and depending on the refractive index, for example, 1,1,1,3,3,3-hexafluoro-2-propanol, 2-propanol, chloroform, tetrachloride Solvents such as carbon, toluene, glycerin and the like can be mentioned.

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

(4) Adhesion The hard coat layer described in the item of formation of the above-mentioned hard coat layer was formed on the easily bonding layer of the polyester film obtained in the example. Based on the description of JIS-K5400-1990 8.5.1, the adhesion film of the hard coat layer and the base film is determined according to the description of JIS-K5400-1990 8.5.1.

Specifically, using a cutter guide with a gap of 2 mm, 100 square cuts are made on the surface of the hard coat layer to penetrate the hard coat layer and reach the base film. Then, a cellophane adhesive tape (manufactured by Nichiban, No. 405; 24 mm width) is attached to the square-shaped cut surface and rubbed completely with an eraser. Thereafter, the cellophane adhesive tape is vertically peeled off from the hardcoat layer surface of the hardcoat laminate polarizer protective film, and the number of squares separated from the hardcoat layer surface of the hardcoat laminate polarizer protective film is visually counted, and the following formula The adhesion between the hard coat layer and the substrate film is determined from the above. In addition, what has exfoliated partially among squares is also counted as a detached square.

Adhesion (%) = {1− (number of peeled squares / 100)} × 100

(5) Moisture and heat resistance The laminated film for polarizer protection formed with the above-mentioned hard coat is left in an environment of 85 ° C. and 85 RH% for 500 hours in a high temperature and high humidity tank, and then the hard coat laminated polarizer protective film is taken out. And left at room temperature for 12 hours. Thereafter, the adhesion between the hard coat layer and the substrate film was determined in the same manner as described above to obtain heat and humidity resistance.

(6) Coefficient of static friction, coefficient of dynamic friction (μs, μd)
The coefficient of friction of the polyester film obtained in the examples was measured using Tensilon (Toyo Baldwin, RTM-100) in accordance with the JIS K 7125-1999 Plastic Film and Sheet Friction Coefficient Test Method.

(7) Interference fringe improvement (iris-like color)
A hard coat layer was formed on the easy adhesion layer of the optical adhesion easy polyester film obtained in each example. A readily coatable optical polyester film having a hard coat formed thereon was cut into an area of 10 cm (film width direction) × 15 cm (film longitudinal direction) to prepare a sample film. A black glossy tape (manufactured by Nitto Denko Corporation, vinyl tape No. 21; black) was attached to the surface of the obtained sample film opposite to the hard coat surface. The hard coat surface of this sample film is the upper surface, and the positional relationship (distance 40 from the light source) where the reflection is most strongly visible visually from above at a light source with three-wave form daylight white (National Paulc, FL 15EX-N 15 W) It observed at 60 cm and the angle of 15-45 degrees.

The results of visual observation are ranked according to the following criteria. In addition, observation is performed by five persons familiar with the evaluation, and the highest rank is regarded as the evaluation rank. If two ranks were equal, the center of the rank divided into three was adopted. For example, if ◎ and が are each 2 people and が is 1 person, ○ is 1 person and ○ is 1 if ○ and 2 are 2 each, △ and が are 1 each In the case of a name, each ○ is adopted.
A: No iris-like color is observed at all viewing angles. O: A slight iris-like color is observed at certain angles. C: A slight iris-like color is observed. X: A clear iris-like color is observed. To be

(8) Scratch resistance of coated layer Attach 3 cm (film width direction) x 20 cm (film longitudinal direction) of an easy-to-adhere polyester film for optics on a rub fastness tester (RT-200, manufactured by Daiei Kagaku Seiki) 10c using black backing paper (80 μm thick, arithmetic average surface roughness 0.03 μm) at the contact portion of the load head (2 cm x 2 cm, 200 g) with the weight (300 g) and the sample film
The distance of m was reciprocated three times at a speed of 20 seconds per reciprocation. The obtained sample film was placed on a black backing and visually checked for scratches.
○: no scratches can be confirmed on the black backing, or slight scratches depending on the location can be confirmed Δ: a slight scratch can be generally confirmed on the black backing ×: the scratches are clearly visible on the black backing it can

(9) Glass transition temperature
Obtained from a DSC curve by heating 10 mg of a resin sample at a temperature of 25 to 300 ° C. at a temperature of 20 ° C./min using a differential scanning calorimeter (DSC 6200, manufactured by Seiko Instruments Inc.) in accordance with JIS K 712 1-1987. The extrapolated glass transition start temperature was taken as the glass transition temperature.

(10) Number average molecular weight
0.03 g of resin is dissolved in 10 ml of tetrahydrofuran, GPC-LALLS apparatus low angle light scattering photometer LS-8000 (made by Tosoh Corporation, tetrahydrofuran solvent, reference: polystyrene), column temperature 30 ° C., flow rate 1 ml / min, column The number average molecular weight was measured using (Shodex KF-802, 804, 806 manufactured by Showa Denko KK).

(11) Resin composition
The resin was dissolved in heavy chloroform, and 1H-NMR analysis was performed using a nuclear magnetic resonance analyzer (NMR) Gemini-200 manufactured by Varian. The molar ratio of each composition was determined from the integral ratio.

(12) Surface roughness (Ra)
Based on JIS-B0601-2001, Ra was measured with Surfcom (registered trademark) 304B (manufactured by Tokyo Seimitsu Co., Ltd.). The measurement conditions were a cutoff of 0.08 μm, a stylus radius of 2 μm, a measurement length of 0.8 mm, and a measurement speed of 0.03 mm / sec.

(Polymerization of polyester resin)
In a stainless steel autoclave equipped with a stirrer, a thermometer, and a partial reflux condenser, 194.2 parts by mass of dimethyl terephthalate, 184.5 parts by mass of dimethyl isophthalate, 14.8 parts by mass of dimethyl 5-sodium sulfoisophthalate, 233.5 parts by mass of diethylene glycol, 136.6 parts by mass of ethylene glycol, and 0.2 parts by mass of tetra-n-butyl titanate were charged, and transesterification was performed at a temperature of 160 ° C. to 220 ° C. for 4 hours. Then, the temperature was raised to 255 ° C., and the reaction system was gradually depressurized, and then reacted under a reduced pressure of 30 Pa for 1 hour and 30 minutes to obtain a copolyester resin (I). The resulting copolyester resin (I) was pale yellow and transparent. The reduced viscosity of the copolyester resin (I) was measured to be 0.70 dl / g. The glass transition temperature by DSC was 40 ° C., and the number average molecular weight was 20000.
The composition of the copolyester resin (I) is as follows.
Dicarboxylic acid composition: 49% by mole of terephthalic acid, 48% by mole of isophthalic acid, 3% by mole of 5-sodium isophthalic acid
-Diol component: ethylene glycol 40 mol%, diethylene glycol 60 mol%

(Production of polyester water dispersion)
In a reactor equipped with a stirrer, a thermometer and a reflux apparatus, 30 parts by mass of the copolymerized polyester resin (I) and 15 parts by mass of ethylene glycol-n-butyl ether were added, and heated and stirred at 110 ° C. to dissolve the resin. After the resin was completely dissolved, 55 parts by weight of water was gradually added to the polyester solution while stirring. After the addition, the solution was cooled to room temperature while stirring to prepare a milky white polyester water dispersion (Iα) having a solid content of 28.2% by mass.

(Manufacture of polyurethane water dispersion)
In a four-necked flask equipped with a stirrer, Dimroth condenser, nitrogen inlet tube, silica gel drying tube, and thermometer, 43.75 parts by mass of 4,4-dicyclohexylmethane diisocyanate, 12.85 parts by mass of dimethylol butanoic acid, 153.41 parts by mass of polyhexamethylene carbonate diol having a number average molecular weight of 2000, 0.03 parts by mass of dibutyltin dilaurate, and 84.00 parts by mass of acetone as a solvent are added, and stirred at 75 ° C. for 3 hours under nitrogen atmosphere to react It was confirmed that the solution reached a predetermined amine equivalent. Next, this reaction solution was cooled to 40 ° C., and then 8.77 parts by mass of triethylamine was added to obtain a polyurethane prepolymer solution. Next, 450 g of water was added to a reaction vessel equipped with a high-speed stirable homodisper, adjusted to 25 ° C., and polyurethane prepolymer solution was added and dispersed while stirring and mixing at 2000 min ⁻¹ . Thereafter, a water-soluble polyurethane resin solution (II) having a solid content of 37% by mass was prepared by removing a part of acetone and water under reduced pressure. The glass transition temperature of the obtained polyurethane resin (II) was -30 ° C.

(Polymerization of block polyisocyanate based crosslinking agent)
100 parts by mass of polyisocyanate compound having isocyanurate structure (Duranate TPA, manufactured by Asahi Kasei Chemicals Co., Ltd., manufactured by Asahi Kasei Chemicals, Inc.), 55 parts by mass of propylene glycol monomethyl ether acetate, having a stirrer, a thermometer, and a reflux condenser 30 parts by mass of polyethylene glycol monomethyl ether (average molecular weight 750) was charged, and maintained at 70 ° C. for 4 hours under a nitrogen atmosphere. Thereafter, the reaction solution temperature was lowered to 50 ° C., and 47 parts by mass of methyl ethyl ketoxime was dropped. The infrared spectrum of the reaction solution was measured to confirm that the absorption of the isocyanate group disappeared, and a block polyisocyanate water dispersion (III) having a solid content of 75% by mass was obtained.

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

(Polymerization of carbodiimide type crosslinking agent)
In a flask equipped with a stirrer, thermometer, and reflux condenser, 168 parts by mass of hexamethylene diisocyanate and 220 parts by mass of polyethylene glycol monomethyl ether (M 400, average molecular weight 400) are charged, and stirred at 120 ° C. for 1 hour. 26 parts by mass of 4'-dicyclohexylmethane diisocyanate and 3.8 parts by mass of 3-methyl-1-phenyl-2-phospholene-1-oxide (2% by mass with respect to all isocyanates) as a carbodiimidization catalyst are added, under nitrogen stream 185 Stir at C for a further 5 hours. The infrared spectrum of the reaction solution was measured, and it was confirmed that the absorption at a wavelength of 2200 to 2300 cm ⁻¹ disappeared. The mixture was allowed to cool to 60 ° C., and 567 parts by mass of ion exchange water was added to obtain a carbodiimide water-soluble resin (V) having a solid content of 40% by mass.

(Epoxy based crosslinking agent)
Nagase ChemteX Co., Ltd. Denacol EX-521 (solid content concentration 100%) was used as an epoxy-type crosslinking agent (epoxy-type crosslinking agent (VI)).

(Melamine based crosslinking agent)
Beckamine M-3 (solid content concentration: 60%) manufactured by DIC Corporation was used as a melamine-based crosslinking agent (melamine-based crosslinking agent (VII)).

(Zirconia particles)
In 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 mass% aqueous oxalic acid solution. While stirring this aqueous solution, 495.8 g of zirconium oxycarbonate powder (ZrOCO ₃ , manufactured by AMR International Corp., containing 39.76% by mass in terms of ZrO ₂ ) is gradually added and mixed for 30 minutes. And heating at 90 ° C. for 30 minutes. Next, 1747.2 g of a 25.0% by mass aqueous tetramethylammonium hydroxide solution (manufactured by Tama Chemicals Co., Ltd.) was gradually added over 1 hour. At this time, the mixture was in the form of a slurry and contained 4.0% by mass in terms of ZrO ₂ . The slurry was transferred to a stainless steel autoclave vessel and subjected to hydrothermal treatment at 145 ° C. for 5 hours. The product after the hydrothermal treatment was completely solified without undigested matter. The obtained sol contained 4.0% by mass as ZrO ₂ , pH 6.8, and the average particle size by dynamic light scattering was 19 nm. Further, the transmittance was measured by adjusting the sol to a ZrO ₂ concentration of 2.0% by mass with pure water, and it was 88%. The particles were observed by a transmission electron microscope, and it was found that aggregated particles of ZrO ₂ primary particles of around 7 nm were mostly. Using an ultrafiltration device, 4000 g of a zirconia sol having a concentration of 4.0% by mass of ZrO ₂ obtained by performing the above hydrothermal treatment is washed and concentrated while gradually adding pure water using an ultrafiltration device to obtain a concentration of ZrO ₂ 953 g of a zirconia sol having a transmittance of 76% was obtained at 13.1% by mass, pH 4.9, and ZrO ₂ concentration of 13.1% by mass.

After adding 3.93 g of a 20 mass% citric acid aqueous solution and 11.0 g of a 25 mass% aqueous tetramethylammonium hydroxide solution to 300 g of a zirconia sol having a concentration of 13.1 mass% of ZrO ₂ obtained by performing the above washing and concentration Further, when concentration was performed using an ultrafiltration device, 129 g of a high concentration zirconia sol having a ZrO ₂ concentration of 30.5% by mass was obtained. The obtained high concentration zirconia sol had a pH of 9.3 and an average particle diameter of 19 nm according to a dynamic light scattering method. In addition, this zirconia sol had no sediment and was stable for more than one month at 50 ° C.

(Titania particles)
12.09 kg of a titanium tetrachloride aqueous solution containing 7.75% by mass of titanium tetrachloride (Osaka Titanium Technologies Co., Ltd.) based on TiO ₂ conversion basis and an ammonia water (15% by mass of ammonia) (manufactured by Ube Industries, Ltd.) 4.) It mixed with 4.69 kg and prepared white slurry liquid of pH 9.5. Next, this slurry was filtered and then washed with pure water to obtain 9.87 kg of a hydrous titanic acid cake having a solid content of 10% by mass. Next, 11.28 kg of hydrogen peroxide water (made by Mitsubishi Gas Chemical Co., Ltd.) containing 35% by mass of hydrogen peroxide and 20.00 kg of pure water are added to this cake, and then it is kept at a temperature of 80 ° C. for 1 hour The reaction solution was heated under stirring, and 57.52 kg of pure water was further added to obtain 98.67 kg of an aqueous peroxide solution containing 1% by mass of a peroxide peroxide based on TiO ₂ conversion. The aqueous solution of peroxytitanic acid was clear yellow-brown and had a pH of 8.5.

Next, 98.67 kg of the aqueous solution of peroxytitanic acid was mixed with 4.70 kg of cation exchange resin (Mitsubishi Chemical Co., Ltd.), to which potassium stannate (produced by Showa Kako) was converted to SnO ₂ 12.33 kg of potassium stannate aqueous solution containing 1 mass% on the basis was gradually added under stirring. Next, after separating the cation exchange resin which took in potassium ion etc., it was put into an autoclave (made by pressure glass industry Ltd., 120 L), and heated at a temperature of 165 ° C. for 18 hours.

Next, after cooling the obtained mixed aqueous solution to room temperature, it is concentrated with an ultrafiltration membrane device (manufactured by Asahi Kasei Corporation, ACV-3010) to obtain titanium-based fine particles (solid content: 10% by mass) Hereinafter, 9.90 kg of water-dispersed sols containing “P-1” were obtained. When the solid contained in the sol thus obtained is measured by the above method, it is titanium-based fine particles (primary particles) having a rutile type crystal structure and composed of a composite oxide containing titanium and tin. The Furthermore, when the content of the metal component contained in the titanium-based fine particles was measured, it was found that TiO ₂ 87.2% by mass, SnO ₂ 11.0% by mass, and K ₂ O based on the oxide conversion of each metal component. It was 1.8% by mass. In addition, the pH of the mixed aqueous solution was 10.0. Furthermore, the water-dispersed sol containing the titanium-based fine particles is transparent milky white, and the average particle diameter of the titanium-based fine particles contained in the water-dispersed sol is 35 nm, and further coarse particles having a particle diameter of 100 nm or more. The distribution frequency was 0%. Furthermore, the refractive index of the obtained titanium-based fine particles could be considered to be 2.42.

(Zirconia / titania mixed particles)
The zirconia particles and the titania particles obtained above were mixed in respective proportions to prepare zirconia / titania mixed particles having a solid content concentration of 13% by mass.

(Formation of hard coat layer)
A coating solution for hard coat layer formation of the following composition is applied using a # 10 wire bar on the surface opposite to the surface to be bonded to the polarizer of the polyester film manufactured in the example described later, using 70 ° C. for 1 minute Dry and remove solvent. Next, the film coated with the hard coat layer was irradiated with ultraviolet light of 300 mJ / cm ² using a high pressure mercury lamp to obtain a polarizer protective film having a hard coat layer with a thickness of 5 μm.
・ Coating solution for hard coat layer formation
Methyl ethyl ketone 65.00 mass%
Dipentaerythritol hexaacrylate 27.20 mass%
(Shin-Nakamura Chemical A-DPH)
Polyethylene diacrylate 6.80% by mass
(Shin-Nakamura Chemical A-400)
Photopolymerization initiator 1.00 mass%
(Chiva's Specialty Chemicals Irgacure 184)

Example 1
(Preparation of coating solution)
A coating solution of the following composition was prepared.
Water 34.94 parts by mass Isopropyl alcohol 30.00 parts by mass Particle A-1 7.24 parts by mass (A zirconia / titania mixed particle having an average particle size of 23 nm,
75% by mass of zirconia based on the total mass of zirconia / titania,
Solid content concentration 13 mass%)
Particle B-1 0.90 parts by mass (silica sol having an average particle size of 450 nm, solid content concentration 40% by mass)
Polyester water dispersion (Iα) 17.92 parts by mass (solid content concentration 28.2% by mass)
Blocked isocyanate crosslinking agent (III) 2.90 parts by mass (solid content concentration 75% by mass)
0.30 parts by mass of surfactant (Fuso-based, solid content 10% by mass)
High boiling point solvent 3.00 parts by mass Dispersion aid 0.26 parts by mass

(Production of easy adhesion polyester film)
As a film raw material polymer, PET resin pellets having an intrinsic viscosity (solvent: phenol / tetrachloroethane = 60/40) of 0.62 dl / g and containing substantially no particles, are obtained at a pressure of 133 Pa and a temperature of 135C. Dried for hours. Then, it was supplied to an extruder, and melt extruded into a sheet at about 280 ° C., followed by rapid cooling adhesion solidification on a rotary cooling metal roll kept at a surface temperature of 20 ° C. to obtain an unstretched PET sheet.

  The unstretched PET sheet was heated to 100 ° C. with a heated roll group and an infrared heater, and then stretched 3.5 times in the longitudinal direction with a roll group having a peripheral speed difference to obtain a uniaxially stretched PET film.

Next, the coating solution was applied to one side of a PET film by roll coating, and then dried at 80 ° C. for 15 seconds. The coating amount after drying after final stretching was adjusted to be 0.12 g / m ² . Subsequently, the film is stretched 4.0 times in the width direction at 150 ° C. with a tenter, heated at 230 ° C. for 0.5 seconds with the length in the width direction of the film fixed, and further 10 seconds at 230 ° C. % Widthwise relaxation treatment was carried out to obtain a 38 μm thick easy-adhesive polyester film.

(Example 2)
An easily adhesive polyester film was prepared in the same manner as in Example 1, except that the ratio of the mass of zirconia to the total mass of zirconia and titania was changed to 50% by mass of particle A-2 instead of particle A-1 of the coating solution. I got

(Example 3)
An easily adhesive polyester film was prepared in the same manner as in Example 1, except that the ratio of the mass of zirconia to the total mass of zirconia and titania was changed to 25% by mass of particle A-3 instead of particle A-1 of the coating solution. I got

(Example 4)
An easily adhesive polyester film was obtained in the same manner as in Example 1 except that a coating liquid having the following composition was prepared and used in place of the coating liquid prepared and used in Example 1.
Water 37.23 parts by mass isopropyl alcohol 30.00 parts by mass particles A-1 3.79 parts by mass (zirconia / titania mixed particles having an average particle size of 23 nm,
75% by mass of zirconia based on the total mass of zirconia / titania,
Solid content concentration 13 mass%)
Particle B-1 0.95 parts by mass (silica sol with an average particle diameter of 450 nm, solid content concentration 40% by mass)
Polyester water dispersion (Iα) 18.77 parts by mass (solids concentration 28.2% by mass)
Blocked isocyanate type crosslinking agent (III) 3.03 parts by mass (solid content concentration 75% by mass)
0.30 parts by mass of surfactant (Fuso-based, solid content 10% by mass)
High boiling point solvent 3.00 parts by mass Dispersion aid 0.27 parts by mass

(Example 5)
An easily adhesive polyester film was obtained in the same manner as in Example 1 except that a coating liquid having the following composition was prepared and used in place of the coating liquid prepared and used in Example 1.
Water 32.85 parts by mass Isopropyl alcohol 30.00 parts by mass Particle A-1 10.39 parts by mass (A zirconia / titania mixed particle having an average particle size of 23 nm,
75% by mass of zirconia based on the total mass of zirconia / titania,
Solid content concentration 13 mass%)
Particle B-1 0.87 parts by mass (Silica sol having an average particle diameter of 450 nm, solid content concentration 40% by mass)
Polyester water dispersion (Iα) 17.15 parts by mass (solid content concentration 28.2% by mass)
Blocked isocyanate type crosslinking agent (III) 2.80 parts by mass (solid content concentration 75% by mass)
0.30 parts by mass of surfactant (Fuso-based, solid content 10% by mass)
High-boiling point solvent 3.00 parts by mass Dispersion aid 0.25 part by mass

(Example 6)
An easily adhesive polyester film was obtained in the same manner as in Example 1 except that a coating liquid having the following composition was prepared and used in place of the coating liquid prepared and used in Example 1.
Water 39.17 parts by mass isopropyl alcohol 30.00 parts by mass particles A-1 7.24 parts by mass (zirconia / titania mixed particles having an average particle size of 23 nm,
75% by mass of zirconia based on the total mass of zirconia / titania,
Solid content concentration 13 mass%)
Particle B-1 0.90 parts by mass (silica sol having an average particle size of 450 nm, solid content concentration 40% by mass)
Polyurethane water dispersion (II) 13.70 parts by mass (solid content concentration 37% by mass)
Blocked isocyanate crosslinking agent (III) 2.90 parts by mass (solid content concentration 75% by mass)
0.30 parts by mass of surfactant (Fuso-based, solid content 10% by mass)
High boiling point solvent 3.00 parts by mass Dispersion aid 0.26 parts by mass

(Example 7)
An easily adhesive polyester film was obtained in the same manner as in Example 1 except that a coating liquid having the following composition was prepared and used in place of the coating liquid prepared and used in Example 1.
Water 34.94 parts by mass Isopropyl alcohol 30.00 parts by mass Particle A-1 7.24 parts by mass (A zirconia / titania mixed particle having an average particle size of 23 nm,
75% by mass of zirconia based on the total mass of zirconia / titania,
Solid content concentration 13 mass%)
Particle B-1 0.90 parts by mass (silica sol having an average particle size of 450 nm, solid content concentration 40% by mass)
Polyester water dispersion (Iα) 13.27 parts by mass (solids concentration 28.2% by mass)
Polyurethane water dispersion (II) 4.98 parts by mass (solid content concentration 37% by mass)
Blocked isocyanate crosslinking agent (III) 2.90 parts by mass (solid content concentration 75% by mass)
0.30 parts by mass of surfactant (Fuso-based, solid content 10% by mass)
High boiling point solvent 3.00 parts by mass Dispersion aid 0.26 parts by mass

(Example 8)
An easily adhesive polyester film was obtained in the same manner as in Example 1 except that the block isocyanate type crosslinking agent (III) of the coating solution was changed to a water soluble resin (IV) having an oxazoline group and the content thereof was adjusted. The

(Example 9)
Coating solution blocked isocyanate type crosslinking agent (III) carbodiimide water soluble resin (V)
An easily adhesive polyester film was obtained in the same manner as in Example 1 except that the content was changed.

(Example 10)
An easily adhesive polyester film was obtained in the same manner as in Example 1 except that the blocked isocyanate crosslinking agent (III) of the coating solution was changed to the melamine crosslinking agent (VII) and the content thereof was adjusted.

(Example 11)
An easily adhesive polyester film was obtained in the same manner as in Example 1 except that the block isocyanate type crosslinking agent (III) of the coating solution was changed to the epoxy type crosslinking agent (VI) and the content thereof was adjusted.

(Example 12)
An easily adhesive polyester film was obtained in the same manner as in Example 1 except that the average particle diameter was changed to particles A-4 of 40 nm instead of the particles A-1 of the coating solution.

(Example 13)
An easily adhesive polyester film was obtained in the same manner as in Example 1 except that the average particle diameter was changed to particles A-5 of 30 nm instead of particles A-1 of the coating solution.

(Example 14)
An easily adhesive polyester film was obtained in the same manner as in Example 1 except that the film thickness of the coating layer was changed to 0.05 μm.

(Example 15)
An easily adhesive polyester film was obtained in the same manner as in Example 1 except that the thickness of the coating layer was changed to 0.075 μm.

(Example 16)
An easily adhesive polyester film was obtained in the same manner as in Example 1 except that the thickness of the coating layer was changed to 0.125 μm.

(Example 17)
An easily adhesive polyester film was obtained in the same manner as in Example 1 except that a coating liquid having the following composition was prepared and used in place of the coating liquid prepared and used in Example 1.
Water 35.40 parts by mass isopropyl alcohol 30.00 parts by mass particles A-1 7.26 parts by mass (zirconia / titania mixed particles having an average particle size of 23 nm,
75% by mass of zirconia based on the total mass of zirconia / titania,
Solid content concentration 13 mass%)
Particle B-1 0.36 parts by mass (Silica sol having an average particle diameter of 450 nm, solid content concentration 40% by mass)
Polyester water dispersion (Iα) 17.98 parts by mass (solid content concentration 28.2% by mass)
Blocked isocyanate crosslinking agent (III) 2.90 parts by mass (solid content concentration 75% by mass)
0.30 parts by mass of surfactant (Fuso-based, solid content 10% by mass)
High boiling point solvent 3.00 parts by mass Dispersion aid 0.26 parts by mass

(Example 18)
An easily adhesive polyester film was obtained in the same manner as in Example 1 except that a coating liquid having the following composition was prepared and used in place of the coating liquid prepared and used in Example 1.
Water 34.48 parts by weight Isopropyl alcohol 30.00 parts by weight Particles A-1 7.22 parts by weight (A zirconia / titania mixed particle having an average particle size of 23 nm,
75% by mass of zirconia based on the total mass of zirconia / titania,
Solid content concentration 13 mass%)
Particles B-1 1.44 parts by mass (silica sol with an average particle diameter of 450 nm, solid content concentration 40% by mass)
Polyester water dispersion (Iα) 17.88 parts by mass (solids concentration 28.2% by mass)
Blocked isocyanate crosslinking agent (III) 2.90 parts by mass (solid content concentration 75% by mass)
0.30 parts by mass of surfactant (Fuso-based, solid content 10% by mass)
High boiling point solvent 3.00 parts by mass Dispersion aid 0.26 parts by mass

(Comparative example 1)
An easily adhesive polyester film was obtained in the same manner as in Example 1 except that the non-mixed zirconia single particle A-6 containing no titania was changed instead of the particle A-1 of the coating solution.

(Comparative example 2)
In the same manner as in Example 1 except that instead of particle A-1 of the coating solution, non-mixed titania single particle A-7 not containing zirconia was changed and mass% was adjusted in consideration of solid concentration. An easily adhesive polyester film was obtained.

(Comparative example 3)
An easily adhesive polyester film was obtained in the same manner as in Example 1 except that a coating liquid having the following composition was prepared and used in place of the coating liquid prepared and used in Example 1.
Water 35.71 parts by mass isopropyl alcohol 30.00 parts by mass particles A-1 7.27 parts by mass (zirconia / titania mixed particles having an average particle diameter of 23 nm,
75% by mass of zirconia based on the total mass of zirconia / titania,
Solid content concentration 13 mass%)
Polyester water dispersion (Iα) 28.58 parts by mass (solid content concentration 28.2% by mass)
Blocked isocyanate type crosslinking agent (III) 1.38 parts by mass (solid content concentration 75% by mass)
0.30 parts by mass of surfactant (Fuso-based, solid content 10% by mass)
High boiling point solvent 3.00 parts by mass Dispersion aid 0.26 parts by mass

  The easily adhesive polyester film obtained in each of the examples is excellent in scratch resistance, has a suitable coefficient of static friction and dynamic friction, and is satisfactory in each of the evaluation items of transparency, adhesion, moist heat resistance and low interference. Results were obtained. On the other hand, the easily adhesive polyester film obtained by Comparative Example 1 was not satisfactory in heat and moisture resistance because the particles A in the coating layer did not contain zirconia. Further, the easily adhesive polyester film obtained by Comparative Example 2 was not satisfactory in scratch resistance because the particles A in the coating layer did not contain titania. And the easily adhesive polyester film obtained by Comparative Example 3 had a large coefficient of friction because it did not contain the lubricant particles B in the coating layer.

(Example 19)
A coating solution for forming an antiglare layer having the following composition is coated on the coating layer of the easily adhesive polyester film obtained in Example 1 using a # 5 wire bar, dried at 70 ° C. for 1 minute, and the solvent is removed did. Next, the film coated with the antiglare layer was irradiated with ultraviolet light of 300 mJ / cm ² using a high pressure mercury lamp to obtain a laminated polyester film having a 5 μm thick antiglare layer. A preferred laminated polyester film provided with antiglare properties was obtained.
· Coating liquid for antiglare layer formation
Toluene 34 parts by mass
Pentaerythritol triacrylate 50 parts by mass
Silica (average particle size 1 μm) 12 parts by mass
1 part by mass of silicone (leveling agent)
1 part by mass of a photopolymerization initiator
(Chiva's Specialty Chemicals Irgacure 184)

Example 20
A coating solution for forming a middle refractive index layer having the following composition is coated on the coating layer of the easily adhesive polyester film obtained in Example 1 using a bar coater, dried at 70 ° C. for 1 minute, and then using a high-pressure mercury lamp It was irradiated with ultraviolet light of 400 mJ / cm ² to obtain a medium refractive index layer having a dry film thickness of 5 μm. Next, using a bar coater, a coating liquid for forming a high refractive index layer having the following composition is formed on the formed middle refractive index layer by the same method as that for the middle refractive index layer, The coating liquid for low refractive index layer formation was formed by the same method as the middle refractive index layer to obtain a laminated polyester film in which an antireflective layer was laminated. A preferred laminated polyester film having antireflective properties was obtained.

・ Coating liquid for medium refractive index layer formation (refractive index 1.52)
70 parts by mass of dipentaerythritol hexaacrylate
1,6-Bis (3-acryloyloxy-2-hydroxypropyloxy) hexane
30 parts by mass
Photopolymerization initiator 4 parts by mass
(Ciba Specialty Chemicals Co., Ltd. Irugacure 184)
100 parts by mass of isopropanol
・ Coating liquid for high refractive index layer formation (refractive index 1.64)
ITO fine particles (average particle size 0.07 μm) 85 parts by mass
15 parts by mass of tetramethylol methane triacrylate
Photopolymerization initiator (KAYACURE BMS, manufactured by Nippon Kayaku) 5 parts by mass
900 parts by mass of butyl alcohol
・ Coating liquid for low refractive index layer formation (refractive index 1.42)
1,10-Diacryloyloxy-2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9-hexadecafluorodecane 70 parts by mass
10 parts by mass of dipentaerythritol hexaacrylate
Silica gel fine particle (XBA-ST, Nissan Chemical Industries) 60 parts by mass
Photopolymerization initiator (KAYACURE BMS, manufactured by Nippon Kayaku) 5 parts by mass

Claims (6)

It is a polyester film having a coating layer on at least one side, wherein the polyester film is a polyester film having at least one of polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate as a component, and the coating layer is A highly adhesive polyester film comprising zirconia / titania mixed particles A, lubricant particles B, and a binder resin, wherein the content ratio of zirconia to the total mass of zirconia and titania in the zirconia / titania mixed particles A is 55 to 90% by mass.   The easily adhesive polyester film according to claim 1, wherein the lubricant particles B have an average particle size of 200 nm or more.   The easily adhesive polyester film according to claim 1 or 2, wherein the average particle diameter of the zirconia / titania mixed particle A is 5 to 200 nm.   The easy-adhesive polyester film according to any one of claims 1 to 3, wherein the content of the lubricant particles B with respect to the solid content of the coating layer is 0.1 to 20% by mass.   The easily adherent polyester film according to any one of claims 1 to 4, wherein the content of the zirconia / titania mixed particle A relative to the solid content of the coating layer is 2 to 50% by mass.   It is selected from the group consisting of a hard coat layer, an antiglare layer, an antiglare antireflective layer, an antireflective layer, and a low reflective layer on the coated layer of the easily adhesive polyester film according to any one of claims 1 to 5. Laminated polyester film having one or more functional layers.