JP4029356B2 - Hard coat film and optical functional film - Google Patents

Description

  The present invention is mainly used for display members, such as a hard coat film, an antireflection film using the film, a light diffusion sheet, a prismatic lens sheet, a near-infrared shielding film, a transparent conductive film, and an antiglare film. The present invention relates to an optical functional film. Specifically, adhesion between the base film and the hard coat layer containing inorganic fine particles, and other optical functional layers (hard coat layer, light diffusion layer, prism layer, infrared absorption layer, transparent conductive layer, antiglare layer, etc.) The present invention relates to a hard coat film having excellent properties and excellent scratch resistance, and an optical functional film using the same.

  Generally, a hard coat film used for a display member such as a liquid crystal display (LCD) or a plasma display panel (PDP) has a thermoplastic resin film and a hard coat (HC) layer laminated via an adhesive modified resin layer. Has been. Furthermore, the optical functional film for display is generally used by bonding optical functional films having different functions through an adhesive layer. However, large flat displays have been increasingly demanded by the market for lower prices in recent years. For this reason, composite films in which other optical functional layers are laminated on one hard coat film have been developed for display members. For example, in a liquid crystal display (LCD), a hard coat film has an antireflection layer (AR layer) that prevents the reflection of external light, a prismatic lens layer that is used to collect and diffuse light, and a light diffusion that improves brightness. Examples include an optical composite functional film in which optical functional layers such as layers are laminated.

  A transparent film made of polyethylene terephthalate (PET), polyamide, acrylic, polycarbonate (PC), triacetyl cellulose (TAC), cyclic polyolefin, or the like is used for the thermoplastic resin film that is the base material of the hard coat film. Among these substrate films, in particular, biaxially oriented polyester films are widely used as thermoplastic resin films for various optical functional films from the viewpoints of excellent transparency, dimensional stability, and chemical resistance.

  In general, in the case of a biaxially oriented thermoplastic film such as a biaxially oriented polyester film or a biaxially oriented polyamide film, the film surface is highly crystallized so that it can adhere to various paints, adhesives, inks, etc. There is a disadvantage of being scarce. For this reason, methods for imparting easy adhesion to the biaxially oriented thermoplastic resin film surface by various methods have been proposed.

  Films that do not have polar groups, such as polyolefin films, have very poor adhesion to various paints, adhesives, inks, etc., so physical and chemical treatments such as corona discharge treatment and flame treatment are performed beforehand. After being performed, methods for imparting easy adhesion to the film surface by various methods have been proposed.

  For example, an adhesive modified layer containing an adhesive modified resin such as film, polyester, acrylic, polyurethane, acrylic graft polyester, etc. is easily adhered to the thermoplastic resin film by providing it on the surface of the thermoplastic resin film by a coating method. A method for imparting sex is generally known. Among these coating methods, a thermoplastic resin film before completion of crystal orientation is subjected to corona discharge treatment directly or as necessary, and then a dispersion obtained by dispersing the resin solution or resin with a dispersion medium is used. The aqueous coating solution is applied to the base film, dried, stretched in at least uniaxial direction, and then subjected to heat treatment to complete the crystal orientation of the thermoplastic resin film (so-called in-line coating method) After manufacturing a plastic resin film, a method (so-called off-line coating method) in which an aqueous or solvent-based coating solution is applied to the film and then dried is widely used industrially.

  LCDs, PDPs, and other displays have been increasing in size and cost each year, and the production speed of optical functional films used as the members has been increased. As the manufacturing process is speeded up, stress due to curing shrinkage is more likely to occur at the interface between the functional layer such as the hard coat layer, the diffusion layer, and the prism layer and the base film. Therefore, in order to produce a display, when cutting an optical functional film to a specific size, if the adhesion at the interface is insufficient, the end part is particularly easily peeled off. The tendency of this tendency is that the larger the film wound up in rolls and the higher the production speed in the manufacturing process, the more the influence of the peeling of the interface due to the impact during cutting becomes more pronounced. Is becoming insufficient.

  Furthermore, the processing agent used for forming the functional layers such as the prism layer and the diffusion layer is applied directly to the base film without being diluted with an organic solvent from the viewpoint of reducing the environmental load. There are many cases. For this reason, there may be a case where the wettability improvement effect of the adhesion modified layer by the organic solvent may not be sufficiently obtained, so that higher adhesion is required. On the other hand, in applications such as hard coat where importance is placed on smoothness, the processing agent is often diluted with an organic solvent in order to lower the viscosity of the processing agent and obtain a good leveling effect. In this case, an appropriate solvent resistance is required for the adhesion modified layer of the adhesion modified substrate film.

  In order to improve the adhesion between the functional layer and the base film, a method of using a resin having a low glass transition temperature as the resin constituting the adhesion modified layer is common. However, when a resin having a low glass transition temperature is used, the blocking resistance tends to decrease when the adhesive modified base film is continuously wound into a roll and the film is unwound from the roll. .

  In recent years, in order to reduce the cost, the size of a processing machine for laminating functional layers such as a hard coat layer and a diffusion layer on a base film has been increased, and a roll of an easily adhesive film used as a base film. The diameter is also increasing. Along with this, when winding with high tension in order to prevent roll misalignment, blocking is more likely to occur because the core of the roll is pressure-bonded with high pressure.

  In order to improve the blocking resistance, a method is generally employed in which irregularities are imparted to the surface of the adhesive modified base film to reduce the contact area. In order to give unevenness to the film surface, a method of increasing the content of inorganic particles or organic particles, or a method of using particles having a large particle diameter, which is contained in the adhesive modified layer or the base film, is generally used. is there. However, the refractive index of commercially available particles is generally different from the refractive index of the resin used for the adhesive modification layer, and voids are formed around the particles as the film is stretched. In this method, the light transmittance of the film is lowered and the haze is raised. In particular, the transparency required for the base film of the optical functional film is lowered. In other words, with conventional methods, it is extremely difficult to improve adhesion and blocking resistance with a functional layer while maintaining transparency due to new problems associated with higher process speeds and larger roll diameters of films. Met.

  Further, in recent years, optical functional films have been used in the case where hard coat layers are provided on both surfaces of a base film for the purpose of preventing adhesion with a light guide plate, increasing transmittance, or reducing curl, or prism lens layers. In many cases, a hard coat layer is laminated on the surface opposite to the optical functional layer such as a light diffusion layer. In particular, the hard coat film is usually a thin cured coating film (hard coat layer) having a thickness of 3 to 10 μm on a thermoplastic resin film using an ionizing radiation curable resin such as a thermosetting resin or an ultraviolet curable resin. ).

  However, since the thickness of the hard coat layer is thinner than that of the base film, the hardness of the hard coat film itself is affected by the base film and does not become sufficiently high. Therefore, in order to further improve the scratch resistance of the hard coat, it has been studied to contain inorganic particles in the hard coat layer.

  On the other hand, when inorganic particles are included in the hard coat layer, the ratio of the curable resin in the hard coat layer decreases, so that adhesion at the interface between the adhesive modified layer of the adhesive modified substrate film and the hard coat layer is reduced. Sex is reduced.

In particular, it is known that a biaxially oriented polyester film has poor adhesion to a coating agent mainly composed of an acrylic resin used for prism lenses, hard coats, and the like. For this reason, various types have been proposed in which an adhesive modification layer made of polyurethane or the like is formed on the surface of a polyester film (see, for example, Patent Document 1). However, in the case where an adhesive property modification layer made of polyurethane is formed, the adhesion with a functional layer such as a hard coat layer is improved, but the adhesion with a polyester film as a substrate is not sufficient, and as a result Adhesiveness is insufficient at the interface between the modified adhesive layer and the functional layer. In particular, the adhesion at the interface between the adhesion modified layer and the hard coat layer containing inorganic particles is remarkably inferior.
JP-A-6-340049

In addition, a resin composition layer mainly composed of copolymer polyester and polyurethane is provided on a base film made of biaxially oriented polyethylene terephthalate by an in-line coating method, and adhesion between the base polyester film and a functional layer such as ink is performed. A method for improving the performance has been proposed (see, for example, Patent Document 2). Specifically, after applying a water-dispersible coating solution containing a copolymerized polyester and polyurethane (= 20/80; mass%) to a polyester film that has been uniaxially stretched in the longitudinal direction, it is guided to a tenter, dried, and then stretched laterally And heat-fixed at 220 ° C. to obtain an easily adhesive biaxially oriented polyester film.
Japanese Patent Publication No. 64-6025

  However, in the method described in Patent Document 2, although the adhesion is improved, in recent years, a substrate film and a functional layer such as a hard coat layer and a diffusion layer, which are required as a substrate film used for an optical functional film, In particular, the adhesion at the interface between the adhesion modified layer and the hard coat layer containing inorganic particles is insufficient.

  The present applicant provides a resin composition layer to which copolymer polyester, polyurethane, and inorganic particles having an appropriate particle diameter are added on a base film made of biaxially oriented polyethylene terephthalate, and further, as an optical base film A laminated polyester film has been proposed that can sufficiently satisfy the required level of adhesion from the market while maintaining transparency, which is a very important characteristic, and has few optical defects (for example, Patent Documents 3 and 4). See). Specifically, a polyester film that is uniaxially stretched in the longitudinal direction, a copolymer polyester, polyurethane (= 20/80; mass%), two kinds of silica particles having different average particle diameters, and water containing an anionic surfactant. An easy-adhesive biaxially oriented polyester film obtained by applying a dispersible coating solution, leading to a tenter, drying, transverse stretching, and heat setting at 240 ° C. was disclosed.

The easy-adhesive biaxially oriented polyester film obtained in Patent Documents 3 and 4 has excellent adhesion and blocking resistance, transparency, and optical defects such as foreign matter and scratches are greatly improved. It satisfied the conventionally required characteristics. However, as mentioned above, with the recent cost reduction and display enlargement, the substrate film, hard coat layer, diffusion layer, prism layer, etc. that are required as a substrate film for optical functional films, etc. The required level of adhesion to the functional layer and blocking resistance tends to be stricter year by year. In particular, the adhesiveness at the interface between the adhesion modified layer and the hard coat layer containing inorganic particles is no longer fully satisfactory for the quality required in the current market.
JP 11-323271 A JP 2000-246855 A

In addition, the present applicant has proposed an invention relating to an easy-adhesive film roll in which the variation in coating amount is reduced in order to improve the uniformity of adhesion (see, for example, Patent Document 5). In an example of Patent Document 5, a polyester film uniaxially stretched in the longitudinal direction, a copolymer polyester and polyurethane (= 50/50; mass%), silica particles having an average particle diameter of 1.4 μm, and fluorine-based surface activity. An easy-adhesive biaxially oriented polyester film obtained by applying a water-dispersible coating solution containing an agent, drying at 120 ° C. in a drying furnace, transversely stretching, and then heat-setting at 220 ° C. is described. Yes. The obtained film roll had excellent adhesion uniformly throughout the film roll, and satisfied the required level from the market. However, the adhesion at the interface between the adhesion modified layer and the hard coat layer containing inorganic particles is not fully satisfactory.
JP 2004-10669 A

In addition, for the purpose of improving scratch resistance, an ionizing radiation curable hard coating agent containing about 40 parts by mass of silica ultrafine particles having a particle size of about 50 nm or less on 100 parts by mass of resin on an easily adhesive polyethylene terephthalate film is dried. A hard coat film that has been applied to a thickness of about 15 μm and cured with an electron beam has been proposed (see, for example, Patent Document 6). However, this hard coat film has a high hardness of the hard coat layer and excellent scratch resistance. However, with respect to the adhesion at the interface between the adhesive modified layer and the hard coat layer containing inorganic particles, It is no longer enough to meet the required quality of the market.
JP 2000-112379 A

On the other hand, a hard coat film is proposed in which a hard coat layer containing no particles is laminated on an easy-adhesion polyethylene terephthalate film having an adhesive modified layer composed of a copolyester and a melamine crosslinking agent (see, for example, Patent Document 7). ). However, this hard coat film is not satisfactory in terms of adhesion to the hard coat layer and hardness of the hard coat layer.
JP 2004-160774 A

  That is, in the prior art, a hard coat film excellent in adhesiveness that can withstand high speed cutting required in recent years while maintaining high hardness, in particular, adhesiveness with a hard coat layer containing inorganic particles has not been obtained. .

  An object of the present invention is to provide a hard coat film that is highly excellent in adhesion at the interface between the adhesion modified layer and the hard coat layer containing inorganic particles and has a high hardness, and an optical functional film using the same. There is.

The above-described problem can be achieved by the following solution means.
That is, the first invention in the present invention is an adhesive modified base film in which an adhesive modified layer B containing a copolymerized polyester and polyurethane is formed on one side or both sides of a thermoplastic resin film A, and the film A hard coat film having a layer structure of A / B / C or B / A / B / C, in which a hard coat layer C containing inorganic fine particles is laminated on the surface of the adhesive modified layer B on one side of The adhesive modification layer B has a microphase separation structure or a nanophase separation structure of a polyester (PEs) phase and a polyurethane (PU) phase, and the cutting surface of the hard coat film using a scanning probe microscope Is observed in the phase measurement mode, the ratio of the adhesive modified layer B defined by the following formula (1) in the range from the interface between the modified adhesive layer B and the hard coat layer C to a depth of 20 nm. A hard coat film, wherein the area ratio of the urethane phase (indicating the bright phase in phase image) is 30% to 60%.
PU phase area ratio (%) = (PU phase area / measurement area) × 100 (1)

The second invention is an adhesive modified substrate film in which an adhesive modified layer B containing a copolymerized polyester and polyurethane is formed on one or both surfaces of a thermoplastic resin film A, and either one of the films. A hard coat film having a layer structure of A / B / C or B / A / B / C, in which a hard coat layer C containing inorganic fine particles is laminated on the surface of an adhesion modified layer B, The modified layer B has a micro phase separation structure or a nano phase separation structure of a polyester (PEs) phase and a polyurethane (PU) phase, and the phase of the surface of the adhesive modification layer B is measured using a scanning probe microscope. When observed in the mode, the area ratio of the polyester phase (indicating a dark hue in the phase image) on the surface of the adhesive modified layer B defined by the following formula (2) is 35% or more in the range of 5 μm × 5 μm. Less than% It is a hard coat film to be a butterfly.
PEs phase area ratio (%) = (PEs phase area / measurement area) × 100 (2)

  A third invention is the hard coat film according to the first or second invention, wherein the content of inorganic fine particles in the hard coat layer C is 20 to 80% by mass.

  According to a fourth aspect of the invention, the thermoplastic resin film contains no particles or 50 ppm or less, and the adhesiveness modified layer contains 0.1 to 20% by mass of particles. Item 3. The hard coat film according to Item 1 or 2.

  A fifth invention is the hard coat film according to the fourth invention, wherein the particles are silica particles.

  In a sixth aspect of the invention, a hard coat layer, a light diffusing layer, a prismatic lens layer, an electromagnetic wave absorbing layer, a near-infrared blocking layer is formed on the surface opposite to the hard coat layer C of the hard coat film described in the first or second invention. An optical functional film in which at least one optical functional layer selected from transparent conductive layers is laminated.

The seventh invention is an optical functional film in which an antireflection layer or an antifouling layer is laminated on the hard coat layer C of the hard coat film described in the first or second invention.
It is.

  The hard coat film of the present invention has a specific micro phase separation structure or nano phase separation structure in the polyester phase and the polyurethane phase as an intermediate layer between the thermoplastic resin film and the hard coat layer, and the adhesion modified layer. The area ratio of the polyurethane phase in the vicinity of the interface with the hard coat layer on the cut surface is in a specific range. Therefore, even when a hard coat layer containing inorganic fine particles is laminated, adhesion with the hard coat layer can be improved while maintaining high hardness. Furthermore, the adhesiveness with optical function layers, such as a diffusion layer and a prism layer, is also excellent.

  Furthermore, a specific amount of particles having a specific particle size is contained only in the adhesive modified layer, or the particles are unevenly distributed in either the polyester phase or the polyurethane phase on the surface of the adhesive modified layer. Thus, the blocking resistance, handling property, and scratch resistance can be improved while maintaining high transparency. Therefore, it is useful as a hard coat film or an optical functional film requiring high transparency. In particular, when silica particles are contained in the adhesive modification layer, the silica particles can be unevenly distributed in the polyurethane phase, so that the drawback of polyurethane having poor blocking resistance can be compensated.

  In the present invention, the definitions of adhesion and hardness described in the problem will be described first.

In the hard coat film of the present invention, the adhesion refers to the hard coat layer and the substrate after the cross-cut peel test (100 squares) using an adhesive tape is repeated 10 times on the hard coat layer containing inorganic fine particles. It means the adhesiveness of the interface with the adhesion modified layer of the film. In the present invention, the adhesiveness defined by the following formula is 80% or more. Preferably it is 85% or more, particularly preferably 90% or more.
Adhesiveness (%) = (1-number of cells peeled off / 100) × 100

In the adhesive modified base film used in the present invention, adhesion refers to a hard coat layer obtained by curing a solvent-diluted photocurable acrylic resin with ultraviolet rays as an adhesive modified layer of the film. It means the adhesiveness at the interface between the acrylic hard coat layer and the film adhesion modified layer after forming and repeating the cross-cut peel test (100 squares) with an adhesive tape 10 times. In the present invention, the adhesiveness defined by the following formula is 80% or more. Preferably it is 85% or more, particularly preferably 90% or more.
Adhesiveness (%) = (1-number of cells peeled off / 100) × 100

  Moreover, the hardness as used in the field of this invention means the "pencil hardness" evaluated by the pencil hardness test based on JIS-K5400. Pencil hardness is the hardness of the pencil used in the test when the hardness of the hard coat layer of the hard coat film is repeated five times, and no abnormalities such as scratches are observed in any test. Is the pencil hardness. For example, using a 3H pencil, the test operation is performed 5 times, and if no appearance abnormality occurs even once, the pencil hardness of the material is set to 3H.

Further, the blocking resistance of the adhesive modified substrate film used in the present invention is such that the adhesive modified layers of two film samples are opposed to each other, and a pressure of 1 kgf / cm ² is applied thereto at 50 ° C. Then, after being in close contact for 24 hours under an atmosphere of 60% RH, the film is peeled off, and the peeled state is “a thing that can be lightly peeled without transfer of the adhesive modified layer”.

  Furthermore, the film having high transparency in the present invention means a film having a haze of 1.5% or less. Preferably, the haze is 1.0% or less.

  In order to obtain excellent adhesion and blocking resistance in the adhesive modified base film used in the present invention, a specific microphase separation structure or nanophase separation structure is developed on the surface of the adhesion modified layer. This is very important. Furthermore, in the hard coat film of the present invention, in order to increase the adhesion between the adhesive modified layer of the adhesive modified substrate film and the hard coat layer containing inorganic fine particles, the surface of the adhesive modified layer, That is, it is important to develop a specific microphase separation structure or nanophase separation structure at the interface with the hard coat layer.

  However, in the hard coat film of the present invention, the adhesive modification layer B is an intermediate layer between the thermoplastic resin film A and the hard coat layer C. That is, the phase separation structure on the surface of the adhesive property modification layer B cannot be observed from the surface of the hard coat film. Therefore, in the present invention, the hard coat film was cut, and the phase separation structure of the adhesion modified layer near the interface with the hard coat layer was observed from the cut surface.

  The specific phase separation structure of the adhesive modified layer in the present invention is the resin composition of the coating solution used for forming the adhesive modified layer, the type and concentration of the surfactant, the coating amount, the adhesive modified layer It can be formed by selectively adopting drying conditions, heat setting conditions, and the like and controlling them.

  First, the outline of the method for producing an adhesion-modified base film used in the present invention will be described using polyethylene terephthalate (hereinafter abbreviated as PET) as a representative example, but it is not limited to this representative example. .

  PET pellets that do not substantially contain particles for the purpose of imparting slipperiness are sufficiently vacuum-dried, then supplied to an extruder, melt-extruded into a sheet at 280 ° C., cooled and solidified, and unoriented A PET sheet is formed. At this time, high-precision filtration is performed at any place where the molten resin is maintained at about 280 ° C. in order to remove foreign substances contained in the resin. The obtained unoriented sheet is stretched 2.5 to 5.0 times in the longitudinal direction with a roll heated to 80 to 120 ° C. to obtain a uniaxially oriented PET film.

  Thereafter, the aqueous solution of the copolymerized polyester and polyurethane is applied to one side or both sides of the uniaxially oriented PET film. To apply the aqueous coating solution, for example, reverse roll coating method, gravure coating method, kiss coating method, roll brush method, spray coating method, air knife coating method, wire barber coating method, pipe doctor method, impregnation -A coating method, a curtain coating method, etc. are mentioned, These methods can be performed individually or in combination.

  Subsequently, the edge part of a film is hold | gripped with a clip, it guide | induces to the hot air zone heated at 80-180 degreeC, and is extended | stretched 2.5 to 5.0 times in the width direction after drying. Subsequently, it is guided to a heat treatment zone of 220 to 240 ° C., and heat treatment is performed for 1 to 20 seconds to complete crystal orientation. In this heat treatment step, a relaxation treatment of 1 to 12% may be performed in the width direction or the longitudinal direction as necessary.

  First, the phase separation structure of the adhesion modified layer of the adhesion modified substrate film used in the present invention will be described. Next, the raw materials and manufacturing conditions used for the hard coat film and optical functional film of the present invention will be described in detail, including the condition factors for controlling the phase separation structure.

(1) Phase Separation Structure of Adhesive Modified Layer In the present invention, the adhesive modified layer comprises a polyester phase (hereinafter sometimes abbreviated as PEs phase) mainly composed of a copolyester and polyurethane. It has a microphase separation structure or a nanophase separation structure of a polyurethane phase (hereinafter sometimes abbreviated as PU phase) as a main component.

  In the hard coat film of the present invention, the adhesion modified layer B is used for the purpose of improving the adhesion between the hard coat layer containing inorganic fine particles and the thermoplastic resin film. Furthermore, when the same hard coat layer and other optical functional layers are laminated on the surface opposite to the hard coat layer, it is also used for the purpose of improving the adhesion between these layers and the thermoplastic resin film.

In the present invention, the adhesive modification layer B has a structure in which a polyester (PEs) phase and a polyurethane (PU) phase are microphase-separated or nanophase-separated, and the hard coat film is cut using a scanning probe microscope. When the surface is observed in the phase measurement mode, the polyurethane phase of the adhesive modified layer B defined by the following formula in the range from the interface between the adhesive modified layer B and the hard coat layer C to a depth of 20 nm ( It is an important feature that the area ratio (PU area ratio) of a bright hue in the phase image is 30% or more and 60% or less.
PU phase area ratio (%) = (PU phase area / measured area) × 100

The area ratio of the PU phase is determined as follows.
In the hard coat film of the present invention having a thermoplastic resin film / adhesive modified layer / hard coat layer as a structural unit, in order to calculate the area ratio of the PU phase of the adhesive modified layer of the intermediate layer, It is necessary to expose the buried adhesive modification layer on the surface.

  As a method for exposing the adhesive modified layer to the surface, a method of cutting a film from an oblique direction using a surface interface property analyzer (SAICAS manufactured by Daipura Wintes Co., Ltd.) is suitable. Next, using a scanning probe microscope (SPM), the phase separation structure is observed from the phase image of the adhesive modified layer in the phase measurement mode (phase mode), and the area ratio of the PU phase in the vicinity of the hard coat layer is obtained.

The area ratio of the polyurethane phase in the vicinity of the interface with the hard coat layer on the cutting surface of the adhesive modified layer has the following technical significance.
When the area ratio of the polyurethane phase exceeds 60%, the ratio of the polyurethane phase on the surface of the adhesive modified layer becomes relatively large during the production of the adhesive modified base film, and the frequency of blocking resistance decreases. Increase. On the other hand, when the area ratio of the polyurethane phase is less than 30%, the frequency with which the adhesiveness is reduced increases. In particular, the adhesion with respect to the solventless hard coat agent and the lens forming resin is significantly reduced.

  The upper limit of the area ratio of the polyurethane phase in the adhesion modified layer near the interface with the hard coat layer is preferably 50% from the viewpoint of blocking resistance. On the other hand, the lower limit of the area ratio of the PU phase is preferably 35% from the viewpoint of adhesion to the hard coat layer and other optical functional layers made of an acrylic resin.

In addition, a microphase separation structure or a nanophase separation structure of PEs phase and PU phase is observed on the surface of the adhesion modified layer of the adhesion modified substrate film before laminating the hard coat layer. When the scanning probe microscope is observed in the phase measurement mode, the area ratio of the polyester phase (indicating a dark hue in the phase image) on the surface of the adhesive modified layer defined by the following formula is 5 μm × 5 μm. The range is 35% or more and less than 90%. In addition, in this invention, when providing an adhesive property modification layer on both surfaces of a thermoplastic resin film, any adhesive property modification layer has the area ratio of the polyester phase similar to the above.
Area ratio (%) of PEs phase = (Area of PEs phase / Measured area) × 100

  The area ratio of the PEs phase on the surface of this adhesion modified layer has the following technical significance. When the area ratio of the PEs phase is less than 35%, the area ratio of the polyurethane phase on the surface of the adhesive property modification layer becomes relatively large, and the frequency with which the blocking resistance decreases is increased. On the other hand, when the area ratio of the PEs phase is 90% or more, the frequency of decrease in adhesion increases. In particular, the decrease in adhesion to a solventless hard coat agent becomes significant.

  The lower limit of the area ratio of the PEs phase on the surface of the adhesive modified layer is preferably 40%, more preferably 45%, and particularly preferably 50% from the viewpoint of blocking resistance. On the other hand, the upper limit of the area ratio of the PEs phase on the surface of the adhesive modified layer is preferably 85%, more preferably 80%, particularly preferably 75%, from the viewpoint of adhesion to the functional layer made of an acrylic resin. It is.

  In the present invention, a phase measurement mode (phase mode) using a scanning probe microscope (SPM) was used for the evaluation of the phase separation structure on the surface of the adhesive modified layer. The phase mode is a phase lag measurement mode that is performed simultaneously with surface morphology observation in a normal dynamic force mode (DFM mode; when SII NanoTechnology SPM is used).

The measurement principle of the phase separation structure of the adhesion modified layer by the phase measurement mode (phase mode) of the scanning probe microscope (SPM) will be briefly described.
In the phase mode, the phase delay of the cantilever vibration when the DFM operation is performed is detected. In the DFM operation, the shape is measured by controlling the distance between the probe and the sample so that the vibration amplitude of the resonated cantilever is constant. Here, when the signal that vibrates the bimorph (piezoelectric element) for vibrating the cantilever is called an “input signal”, in the phase measurement mode, the phase delay of the effective cantilever vibration signal with respect to this “input signal” Is detected simultaneously with the vibration amplitude. The phase delay responds sensitively to the influence of surface properties, and the softer the sample surface, the greater the delay. By imaging the magnitude of this phase lag, it becomes possible to observe the distribution of surface physical properties (referred to as phase image or phase image). Therefore, when a plurality of resin phases having different physical properties exist on the surface, the phase separation structure can be evaluated by this measurement method.

  However, the evaluation of the phase separation structure of the adhesion modified layer can be performed in other modes such as the friction force measurement mode and the viscoelasticity measurement mode in addition to the phase measurement mode as long as it is a surface property distribution evaluation mode by a scanning probe microscope. It is important to select an observation mode that can evaluate the phase separation structure with the highest sensitivity. In the phase measurement mode, not only the phase lag due to the difference in viscoelasticity of the adhesive modified layer can be detected, but also the phase lag due to the difference in surface physical properties such as the magnitude of the adsorption force can be detected.

  When observing the phase separation structure of the cut surface of the adhesive modified layer, in order to facilitate the observation of the phase separation structure, the phase image is read with SPIP software (Version 4.1, manufactured by Image Metrology Co., Ltd.) It is preferable to increase the contrast by performing a color equalization process. The reason is as follows.

  When using a surface interface property analyzer (SAICAS) to cut the hard coat film from the base film side to the inside, it is difficult to completely avoid deformation of the cutting surface of the adhesive modified layer with respect to the cutting direction. is there. In addition, since the inorganic particles contained in the adhesion modified layer cannot be cut, it is inevitable that voids appear around the inorganic particles as a result of damage during cutting. By such cutting, the PU component becomes dominant compared with the PEs component at the interface between the adhesive modified layer exposed on the surface and the thermoplastic resin film or the hard coat layer or other functional layers. This is because the PU component is more susceptible to deformation than the PEs component, the difference in physical properties between the PEs component and the thermoplastic resin film adjacent to the adhesive modified layer, and the adhesiveness cut from an oblique direction From the point that the thickness of the modified layer is extremely thin, it is assumed that the difference in contrast is small.

  The phase separation structure of the adhesive modified layer in the present invention corresponds to a micro phase separation structure or a nano phase separation structure in terms of size. When the phase contrast image of the surface of the adhesive modified layer (interface with the hard coat layer) in the adhesive modified base film used in the present invention is observed, it may have the following phase separation structure. I understand.

  When the PEs phase is regarded as a continuous structure having a major axis and a minor axis, the PEs phase is mainly a continuous structure having a width in the minor axis direction of at most 1 μm and a length in the major axis direction exceeding 1 μm. That is, the area of the portion having the continuous structure is 80% or more, preferably 85% or more, more preferably 90% or more with respect to the entire area of the PEs phase. In addition, even if the PEs phase is dispersed in the form of islands that does not correspond to the continuous structure described in the above definition, the end of the adhesive modified layer that has a continuous structure appears on the surface. Some are.

  The size of the continuous structure of the PEs phase is preferably 1 μm at the maximum in the minor axis direction, more preferably 0.8 μm, still more preferably 0.6 μm, and particularly preferably 0.4 μm. It is. The width in the minor axis direction is not particularly limited as to the lower limit, but in order to maintain a continuous structure, the narrowest portion is preferably 0.01 μm, and particularly preferably 0.05 μm. On the other hand, the size of the continuous structure of the PEs phase is preferably such that the length in the major axis direction exceeds 1 μm, more preferably 1.5 μm or more, still more preferably 2.0 μm or more, and particularly preferably 2.5 μm or more. It is.

  In the adhesive modified base film used in the present invention, the phase separation structure on the surface of the adhesive modified layer shows a complex structure that is not found in nature, as can be seen from the representative example shown in FIG. It is difficult to uniquely define the form of phase separation. The phase separation structure can also be expressed in many ways as follows.

  For example, when the form of the phase-separated structure is expressed as a pattern, it is described in the literature as “dendritic structure” (“Chemical Dictionary”, page 226, June 15, 1979, Sankyo Publishing) Issued by Co., Ltd.), “Rippled structure” (“Pattern”, pages 168-169, issued by Nobara Inc., 2002.0.1), and “Camouflage tone”.

  The phase separation structure on the surface of such an adhesion modified layer is similar to what is expressed as a co-continuous structure in the field of morphology in polymer blend systems. Furthermore, it can also be expressed as a mutual network intrusion structure formed by entanglement of the copolyester and the self-crosslinking polyurethane.

  In terms of form, the self-similarity of the PEs phase can also be quantitatively expressed using the fractal dimension. For example, as shown in FIG. 3, the surface of the adhesive modified layer is observed in a phase measurement mode of a scanning probe microscope, and a phase in which an outline of an interface between a light hue (polyurethane phase) and a dark hue (polyester phase) is emphasized. In the image, the box count method is used as an index indicating the complexity of the boundary between the light hue and the dark hue (interface outline), and it is expressed quantitatively using the fractal dimension obtained from the interface outline. Can do.

  When the fractal dimension in the unit area is 1, it means a straight line (one dimension), and 2 means a solid surface (two dimensions). That is, the closer the fractal dimension is to 2, the denser the structure. On the other hand, a fractal dimension closer to 1 means a sparse structure.

  Specifically, in the phase image in which the outline of the interface between the light hue (polyurethane phase) and the dark hue (polyester phase) is emphasized on the surface of the adhesion modified layer of the adhesive modified substrate film, The fractal dimension of the boundary line (darkness of the interface) between the dark hue and the dark hue is preferably 1.60 to 1.95 in a measurement area of 5 μm × 5 μm. The upper limit of the fractal dimension is more preferably 1.93, and particularly preferably 1.90. On the other hand, the lower limit of the fractal dimension is more preferably 1.65, and particularly preferably 1.70.

  For example, the fractal dimension of the boundary line (interface contour) between the light hue (polyurethane phase) and the dark hue (polyester phase) on the surface of the adhesion modified layer shown in FIG. 4 is 1.89 and 1.90, respectively. is there. 4 emphasizes the outline of the interface between the light hue and the dark hue in the phase image of FIG. 1 showing a typical phase separation structure on the surface of the adhesive modified layer in the present invention. It is the figure which showed the boundary line.

  In the present invention, in order to maximize the functions of the copolyester and polyurethane used as the raw material for the adhesive modified layer, the adhesive modified layer has a micro phase separation structure or a nano phase separation structure. is important. This is because when both resins are completely compatible, the properties of the two resins cancel each other, and overall excellent properties of the copolyester or polyurethane cannot be expected. In the adhesion modified layer, other phase separation structures that can be taken by the PEs phase and the PU phase include those in which the PU phase is dispersed in the PEs phase, and so-called composite forms in which the PES phase is dispersed in the PU phase. It may be possible to show a typical sea-island structure. Of course, this sea-island structure is in an incompatible state of the resin, and if one resin phase is increased, the other is inevitably reduced to form a so-called island. Also in the present invention, if the production conditions are controlled, it is possible to obtain an adhesive modified layer composed of a separated phase having such a sea-island structure.

  However, considering the non-uniformity of the size of the resin phase forming the island structure and the non-uniform distribution state, the influence of the shape, number, and distribution state of the island phase cannot be ignored. For this reason, there is a concern that the properties of the resin constituting the sea structure are greatly affected. In this case, it is considered to be advantageous to maintain the uniformity of the material to form a phase separation structure in which the PEs phase and the PU phase of the present invention are intertwined with each other. A phase separation structure showing a sea-island structure of a PEs phase and a PU phase can also be cited as one of the typical embodiments of the present invention.

  Moreover, a core-shell structure can also be formed as still another phase separation structure of the adhesion modified layer in the present invention. For example, the PEs phase is surrounded by a PU phase, which is further surrounded by a PEs phase. However, in order to form such a core / shell structure, a very high degree of control is required. Also, because of its core / shell structure, it does not seem to be expected to show excellent material behavior.

  Furthermore, as a mode of the phase separation structure, a laminated structure in which PEs phases and PU phases are regularly arranged alternately can be adopted. However, it is ideal that the phases are arranged in parallel at substantially equal intervals. However, if the width of the phase is increased, it becomes difficult to uniformly distribute the PEs phase and the PU phase at the interface of the adhesive modified layer. In this case, the quality of the adhesion-modified base film may be affected. Due to the subtle disposition of the manufacturing conditions, they may be a mixed type while taking the form of a sea-island structure, a core-shell structure, and a laminated structure. However, it is important for maintaining the quality that the PEs phase and the PU phase have a certain size in the adhesion modified layer, and they are uniformly and uniformly mixed.

  A structure in which the PEs phase and the PU phase are phase-separated into two layers in the thickness direction of the adhesive property modification layer is not preferable in the present invention. This is because, in the present invention, it is important from the viewpoint of the effect of the present invention that the PEs phase and the PU phase are uniformly distributed at an appropriate area ratio on the surface of the adhesive modified layer (interface with the hard coat layer). It is.

  As for the phase separation structure on the surface or cutting surface of the adhesive modified layer, the polyester phase mainly composed of copolymerized polyester and the polyurethane phase mainly composed of polyurethane have irregular shapes. And those resin phases form the complicated arrangement | sequence structure which was arrange | positioned irregularly and densely and universally on the surface and inside of an adhesive property modification layer. Moreover, the structure which the other resin phase digged into the surface of one resin phase in the state of incompatibility may be sufficient. In addition, in FIG. 3, a black part shows a polyester phase and a white part shows a polyurethane phase.

  In the case where two types of resin phases are uniformly arranged on the surface of the adhesion modified layer of the adhesion modified substrate film with respect to a unit area (for example, 5 × 5 μm), one resin phase If the dimension of is increased, the dimension of the other resin phase is restricted. Therefore, a large bias occurs in the presence of the resin phase. As a result, it becomes difficult to maintain a state in which both resin phases are separated and uniformly dispersed and unevenness occurs in the material of the adhesive modification layer, which is not preferable for quality control.

  In order to cause both resin phases to be phase-separated and to be present in the adhesive modified layer in a uniformly mixed state, the PEs phase has a maximum width of 1 μm in the minor axis direction and a length in the major axis direction of 1 μm. The above is preferable. Of course, when there is no high demand for quality, a structure having a relatively large width of about 6 μm at the maximum in the minor axis direction is also possible. The phase separation structure of this continuous phase (PEs phase) consists of the resin composition of the coating solution used for the formation of the adhesion modified layer, the type and concentration of the surfactant, the coating amount, the drying conditions of the coating layer, and heat setting. By selectively adopting and controlling conditions and the like, it can be expressed as a microphase separation structure or a nanophase separation structure specific to the adhesion modified layer. In any case, the embodiment of the phase separation structure of the polyester phase and the polyurethane phase on the surface of the adhesive modified layer shown in FIG. 1 is a representative for expressing the effect of the adhesive modified substrate film of the present invention. It is a model.

Further, the importance of the phase separation structure will be described in detail.
The adhesive modified layer in the adhesive modified base film used in the present invention is composed of a copolymer polyester component and a polyurethane component as resin components, and a PEs phase mainly composed of the copolymer polyester and PU composed mainly of polyurethane. It is preferable that the phases are phase-separated and each phase has a continuous structure. By phase-separating the above two types of resins without mixing them together, it has excellent adhesion to a base film made of a thermoplastic resin film and has a relatively good solvent resistance. Polymerized polyester and polyurethane with excellent adhesion to many resins such as hard coat layers, diffusion layers, and acrylate resins, which have poor solvent resistance, have the characteristics of each resin without offsetting their properties. It can be fully utilized.

  Although it is preferable that the polyester phase which comprises an adhesive property modification layer is comprised only by copolyester, 0.01-40 mass% of polyurethane may be included. Furthermore, you may contain 0.001-20 mass% of particles in a polyester phase. In the polyester phase, a surfactant may be attached to or contained in the resin. Similarly, it is preferable that the polyurethane phase is composed of polyurethane alone, and particles, surfactants and the like can be contained in an amount as described in the copolymer polyester. In particular, in the case of particles having a high affinity for polyurethane, it can be selectively distributed in the polyurethane phase more selectively than the polyester phase in the process of forming the adhesion modified layer.

  In general, in a composition composed of a mixture of a copolyester and a polyurethane, there is a case where a chemical supplementary function is usually exhibited in which both materials are chemically uniform materials and complement each other's properties or functions. Many. On the other hand, the adhesion modified layer composed of the polyester phase and the polyurethane phase of the present invention has a large bias in the presence of the resin phase due to physical separation of the polyester phase and the polyurethane phase as described above. As a result, the structure in which both resin phases are separated and uniformly dispersed and arranged is maintained. The properties of each resin are shared through the surface of each resin phase, for example, the copolyester has blocking resistance, the polyurethane has adhesion, and the functions are shared in a phase-separated state. . In other words, it is the manifestation of a physical supplementary function, and this very function or principle is a new technical matter that is not recognized at all in the prior art.

  In the present invention, the detailed generation mechanism of the phase separation structure of the adhesion modified layer is not clear. However, the composition and characteristics of the coating liquid, such as the composition ratio of the copolyester and polyurethane, the ratio of the water / alcohol dispersion medium, the type of surfactant, the impurities in the surfactant, the pH of the aqueous coating liquid, and the coating amount. In addition, each example shows that a specific microphase separation structure or nanophase separation structure is expressed in the adhesion modified layer by a balance of delicate conditions of drying, heat setting treatment, temperature, and wind speed. And can be easily understood from the comparison of the comparative examples.

  Furthermore, it seems that the reaction start temperature of the isocyanate group of polyurethane has a subtle effect. The phase separation structure here does not mean that both the so-called PEs phase and PU phase are separated from each other by a physical boundary, but the boundary is in contact without taking a distance. It appears that a lot of copolyester is gathered and biased in the phase, and a lot of polyurethane is gathered and biased exclusively in the PU phase, and the boundary between the two layers appears to be apparently separated so that it can be clearly distinguished Should. And in the case of this invention, the isocyanate group of polyurethane may have reacted at the boundary, and the complicated isolation | separation structure is shown.

  The adhesive modified base film used in the present invention has an adhesive modified layer composed of a PEs phase and a PU phase, for example, a base composed of a thermoplastic film, a hard coat layer, and a diffusion layer. It plays the role of the interfacial function that acts on both surfaces of the so-called base material surface and the functional layer surface. As a result, both the PEs phase and the PU phase have a structure in which both are separated, and the PEs phase has an excellent property of the copolyester inherent to the both sides of the adhesive modified layer (the base material and the adhesive modified layer). It is in a state where it is exerted to the maximum with respect to the interface and the interface between the adhesion modified layer and the functional layer such as the hard coat layer. That is, the PU phase is in a state in which the excellent properties of the inherent polyurethane are fully exerted on both sides.

  This is because, in an adhesive modified base film having an adhesive modified layer, the surface of the adhesive modified layer has a microphase separation structure or a nanophase separation structure composed of a PEs phase and a PU phase. The PEs phase copolyester is exposed to maximize the properties or functions of the copolyester, and the PU phase polyurethane is exposed to maximize the properties or functions inherent to the polyurethane. It is because it plays. Therefore, if each of the PEs phase and the PU phase on the surface of the adhesion modified layer is distributed in a specific range, the properties or functions of both resins can be exhibited to the maximum. This is because of the unique structure of the laminate, it acts reasonably at the interface between the base material and the adhesive modified layer and at the interface between the adhesive modified layer and the functional layer.

  Furthermore, in the present invention, when particles are contained in the resin composition constituting the PEs phase and the PU phase, for example, silica particles can be unevenly distributed in the PU phase. This is presumed that the surface energy is closer to the silica particles in the PU phase than in the PEs phase. By making the silica particles unevenly distributed in the PU phase, it is possible to improve the blocking resistance, which is a disadvantage of polyurethane, and to reduce the particle content of the entire adhesive modification layer, thus maintaining transparency. It is a useful structure to fulfill the function.

  Similarly, it is suggested that if particles having a surface energy closer to that of the copolyester are selected, the particles can be selectively unevenly distributed in the PEs phase. In a method unpredictable from the prior art, in which particles are unevenly distributed in either a phase separation structure composed of a PEs phase or a PU phase, the slipperiness and blocking properties can be highly improved while maintaining transparency. Therefore, the present invention is also meaningful in that the application range of the material design of the micro phase separation structure or the nano phase separation structure can be expanded.

(2) Thermoplastic resin film As the thermoplastic resin film used in the present invention, an unoriented sheet obtained by melt extrusion or solution extrusion of a thermoplastic resin is stretched in a uniaxial direction in the longitudinal direction or the width direction as necessary. Alternatively, a biaxially stretched thermoplastic resin film that is successively biaxially stretched in the biaxial direction or simultaneously biaxially stretched and subjected to heat setting treatment is preferable.

  In addition, the thermoplastic resin film is a surface activation such as a corona discharge treatment, a glow discharge treatment, a flame treatment, an ultraviolet irradiation treatment, an electron beam irradiation treatment, an ozone treatment, etc., as long as the object of the present invention is not impaired. Processing may be performed.

  The thickness of the thermoplastic resin film used in the present invention can be arbitrarily determined in the range of 30 to 300 μm according to the specification of the application to be used. The upper limit of the thickness of the thermoplastic resin film is preferably 250 μm, particularly preferably 200 μm. On the other hand, the lower limit of the film thickness is preferably 50 μm, particularly preferably 75 μm. When the film thickness is less than 50 μm, rigidity and mechanical strength tend to be insufficient. On the other hand, when the film thickness exceeds 300 μm, the absolute amount of foreign matter present in the film increases, and thus the frequency of optical defects increases. Moreover, the slit property at the time of cut | disconnecting a film to a predetermined width also deteriorates, and manufacturing cost becomes high. Furthermore, since rigidity becomes strong, it becomes difficult to wind a long film in a roll shape.

  As thermoplastic resins, polyolefins such as polyethylene (PE), polypropylene (PP), polymethylpentene (TPX), polyethylene terephthalate (PET), polyethylene-2,6-naphthalate (PEN), polytetramethylene terephthalate (PTT) Polyester resin such as polybutylene terephthalate (PBT), polyamide (PA) resin such as nylon 6, nylon 4, nylon 66, nylon 12, polyimide (PI), polyamideimide (PAI), polyethersulfone (PES), Polyetheretherketone (PEEK), polycarbonate (PC), polyarylate (PAR), cellulose propionate, polyvinyl chloride (PVC), polyvinylidene chloride, polyvinyl alcohol (PVA), polyethylene (Ether imide) (PEI), polyphenylene sulfide (PPS), polyphenylene oxide, polystyrene (PS), syndiotactic polystyrene, and norbornene-based polymer. In addition to using these polymers alone, they may be a copolymer containing a small amount of a copolymer component, or one or more other thermoplastic resins may be blended.

  Among these thermoplastic resins, polyethylene terephthalate, polypropylene terephthalate, polyethylene-2,6-naphthalate, syndiotactic polystyrene, norbornene-based polymer, polycarbonate, polyarylate and the like are preferable. In addition, a resin having a polar functional group such as polyester or polyamide is preferable from the viewpoint of adhesion to the adhesive property modified layer.

  Among them, polyethylene terephthalate, polyethylene-2,6-naphthalate, polybutylene terephthalate, polypropylene terephthalate or a copolymer mainly composed of these resin components is more preferable, and in particular, biaxial orientation formed from polyethylene terephthalate. Films are particularly suitable.

  For example, when a polyester copolymer having polyethylene terephthalate as a basic skeleton is used as a resin for forming a thermoplastic resin film, the ratio of the copolymer component is preferably less than 20 mol%. If it is 20 mol% or more, the film strength, transparency, and heat resistance may be inferior. Examples of the dicarboxylic acid component that can be used as the copolymerization component include aliphatic dicarboxylic acids such as adipic acid and sebacic acid, aromatic dicarboxylic acids such as isophthalic acid, phthalic acid, and 2,6-naphthalenedicarboxylic acid, and trimellilotic acid. And polyfunctional carboxylic acids such as pyromellilottic acid. Examples of the glycol component that can be used as a copolymer component include fatty acid glycols such as diethylene glycol, 1,4-butanediol, propylene glycol, and neopentyl glycol; aromatic glycols such as p-xylene glycol; 1,4-cyclohexane Examples include alicyclic glycols such as dimethanol; polyethylene glycol having an average molecular weight of 150 to 20,000.

  In addition, the thermoplastic resin can contain various additives in addition to the catalyst, as long as the effects of the present invention are not hindered. Examples of additives include inorganic particles, heat-resistant polymer particles, alkali metal compounds, alkaline earth metal compounds, phosphorus compounds, antistatic agents, ultraviolet absorbers, light-resistant agents, flame retardants, heat stabilizers, antioxidants, Examples thereof include an antigelling agent and a surfactant.

  The above particles have a handling property (sliding property, running property, blocking property, air release property of the accompanying air at the time of winding, etc.) at the time of winding up or unwinding in the form of a thermoplastic resin film. From the point, it is used to impart moderate surface irregularities to the film surface.

  Inorganic particles include calcium carbonate, calcium phosphate, amorphous silica, crystalline glass filler, kaolin, talc, titanium dioxide, alumina, silica-alumina composite oxide particles, barium sulfate, calcium fluoride, lithium fluoride, zeolite , Molybdenum sulfide, mica and the like. Examples of the heat resistant polymer particles include crosslinked polystyrene particles, crosslinked acrylic resin particles, crosslinked methyl methacrylate particles, benzoguanamine / formaldehyde condensate particles, melamine / formaldehyde condensate particles, and polytetrafluoroethylene particles. .

  When using a polyester film as the thermoplastic resin film, among the above particles, silica particles are most suitable for applications where transparency is strongly required because the polyester resin is relatively close in refractive index and high transparency is easily obtained. is there. On the other hand, white pigments such as titanium oxide are suitable for applications that require concealment. Moreover, the particle | grains contained in a thermoplastic resin film may be used alone or in combination.

  From the viewpoint of the balance between transparency and handling properties, the type, average particle size, and addition amount of the above particles are 0.01 to 2 μm in average particle size, and 0.01 to 5.0 particle content in the film. What is necessary is just to determine according to the use of a film in the range of the mass%. In addition, when the adhesive modified base film used in the present invention is used for applications where transparency is highly required, the thermoplastic resin film substantially contains particles that cause a decrease in transparency. It is preferable to make it the structure which makes an adhesive property modification layer contain a particle | grain without making it.

  The term “substantially free of particles” means, for example, in the case of inorganic particles, when inorganic elements are quantified by fluorescent X-ray analysis, they are 50 ppm or less, preferably 10 ppm or less, most preferably the detection limit or less. Means content. This means that even if particles are not actively added to the base film, contaminants derived from foreign substances and raw material resin or dirt adhering to the line or equipment in the film manufacturing process will be peeled off and mixed into the film. It is because there is a case to do.

  Moreover, the layer structure of the thermoplastic resin film used in the present invention may be a single layer or a laminated structure imparted with a function that cannot be obtained by a single layer. In the case of a laminated structure, a coextrusion method is preferable.

  The case where polyester is used as a raw material for the thermoplastic resin film will be described in detail below as a representative example of the method for producing the base film.

  The intrinsic viscosity of the polyester pellet used as the film raw material is preferably in the range of 0.45 to 0.70 dl / g. When the intrinsic viscosity is less than 0.45 dl / g, breakage tends to occur frequently during film production. On the other hand, if the intrinsic viscosity exceeds 0.70 dl / g, the filtration pressure rises greatly, high-precision filtration becomes difficult, and the productivity tends to decrease.

  Further, in the hard coat film of the present invention or the optical functional film using the film, it is preferable to remove foreign matters contained in the raw material polyester that cause optical defects. In order to remove foreign substances in the polyester, high-precision filtration is performed at any place where the molten resin is kept at about 280 ° C. during the melt extrusion. The filter medium used for high-precision filtration of the molten resin is not particularly limited, but in the case of a stainless steel sintered filter medium, the removal performance of aggregates and high melting point organic substances mainly composed of Si, Ti, Sb, Ge, Cu Excellent and suitable.

  The filter particle size (initial filtration efficiency 95%) of the filter medium used for high-precision filtration of the molten resin is preferably 15 μm or less. When the filter particle size of the filter medium exceeds 15 μm, removal of foreign matters of 20 μm or more tends to be insufficient. Productivity may be reduced by high-precision filtration of molten resin using a filter medium with a filtration particle size (initial filtration efficiency of 95%) of 15 μm or less, but it is extremely important to obtain a film with few optical defects. It is.

  In the molten resin extrusion process, even fine foreign matter that passes through the filter medium is crystallized around the foreign matter in the cooling process of the sheet-like melt. A difference in thickness is generated to cause a lens state. Here, the light is refracted or scattered as if it were a lens, and when viewed with the naked eye, it appears larger than the actual foreign object. This minute difference in thickness can be observed as the difference between the height of the convex part and the depth of the concave part. The height of the convex part is 1 μm or more and the depth of the concave part adjacent to the convex part is 0.5 μm or more. In this case, due to the lens effect, an object having a size of 20 μm may be visually recognized as a size of 50 μm or more, and may be recognized as an optical defect of a size of 100 μm or more.

  In order to obtain a highly transparent film, it is preferable not to contain particles in the thermoplastic resin film. However, as the particle content is lower and the transparency is higher, optical defects due to minute irregularities tend to become clearer. . In addition, since the surface of a thick film is less likely to be cooled rapidly than a thin film and crystallization tends to proceed, it is necessary to rapidly cool the entire film when manufacturing an unoriented sheet. As a method for cooling the non-oriented sheet, a method in which the molten resin is extruded in a sheet form from a slit portion of a die onto a rotating cooling drum, and the sheet-like melt is brought into close contact with the rotating cooling drum, and is rapidly cooled into a sheet is preferable It is. As a method of cooling the air surface (the surface opposite to the surface in contact with the cooling drum) of the unoriented sheet, a method of cooling by blowing a high-speed air stream is effective.

(3) Adhesive modified layer The adhesive modified base film used in the present invention is an aqueous coating liquid mainly composed of a resin containing a copolymerized polyester and polyurethane, a dispersion medium containing water and alcohol, and a surfactant. Are applied continuously on one or both sides of the traveling thermoplastic resin film, a drying step of drying the coating layer (adhesive modified layer), then a stretching step of stretching at least uniaxially, and further stretching Manufactures an adhesive modified base film with an adhesive modified layer having a microphase separation structure or a nanophase separation structure, which is obtained by continuously forming the coated film through a heat setting treatment process for heat setting. To do. Moreover, at least 1 type of crosslinking agent chosen from an epoxy type crosslinking agent, a melamine type crosslinking agent, and an oxazoline type crosslinking agent may be mixed with a coating liquid, and you may form a crosslinked structure in copolyester.

In the method for producing an adhesive modified base film provided with an adhesive modified layer having a microphase-separated structure or a nanophase-separated structure, the mass ratio (PEs) of the copolyester (PEs) and polyurethane (PU) / PU) is 30/70 to 70/30, and it is preferable to satisfy the following conditions (a) to (f). The same applies when the coating solution contains a crosslinking agent.
(A) The passage time of the film from immediately after application of the coating liquid to the entrance of the drying step is less than 2 seconds (b) 0.1 to 5 seconds at a temperature of 120 to 150 ° C. in the drying step (c) The wind speed is 30 m / sec or more. (D) The heat setting treatment process is continuously divided into a plurality of heat setting zones, and each zone is partitioned so that the temperature can be controlled independently, and the film passes. The temperature of the first heat setting zone is 190 to 200 ° C., the temperature of the heat setting zone set to the maximum temperature is 210 to 240 ° C., and is set to the maximum temperature from the outlet of the first heat setting zone. The passage time of the film to the heat setting zone (in the case of multiple heat setting zones on the most inlet side) is 10 seconds or less. (E) Nonionic surfactant or cationic surfactant is 0 .01-0. 18% by mass (f) The final coating amount of the adhesion modified layer is 0.005 to 0.20 g / m ^2.

Moreover, in the production of the above-mentioned adhesive modified base film, it is more preferable that the following conditions (g) to (i) are satisfied.
(G) The film transit time from immediately after application of the coating solution to the inlet of the drying step is less than 1.5 seconds (h) In the drying step, the temperature is 130 to 150 ° C. for 0.5 to 3 seconds (i) heat setting treatment In the process, the temperature of the heat setting zone set to the maximum temperature is 225 to 235 ° C., and the heat setting zone set to the maximum temperature from the outlet of the first heat setting zone (if there are a plurality, the most inlet The passage time of the film to the heat setting zone on the side) is 5 seconds or less

  In addition, the adhesion modified layer laminated by the in-line coating method contains fine particles having an appropriate particle size to form appropriate irregularities on the surface of the adhesion modified layer, thereby improving slipperiness and winding. Take-off and scratch resistance can be imparted. For this reason, it is not necessary to contain fine particles in the thermoplastic resin film, and high transparency can be maintained.

  The adhesive modified base film used in the present invention preferably has a smooth three-dimensional center plane average surface roughness (SRa) of 0.002 to 0.010 μm on the surface of the adhesive modified layer. The upper limit of SRa is more preferably 0.0080 μm and particularly preferably 0.0060 μm from the viewpoint of transparency. On the other hand, the lower limit of SRa is more preferably 0.0025 μm, particularly preferably 0.0030 μm, from the viewpoints of handling properties such as slipping and winding properties, and scratch resistance.

  With a smooth surface with an SRa of less than 0.002 μm on the surface of the adhesive modified layer, blocking resistance when winding the adhesive modified base film into a roll, or slipperiness during film production or processing, Handling properties such as rollability and scratch resistance are lowered, which is not preferable. On the other hand, if the SRa on the surface of the adhesive modified layer exceeds 0.010 μm, the haze increases and the transparency deteriorates, so that it is not preferable as a base film for a hard coat film or an optical functional film using the same. .

In the adhesive modified substrate film used in the present invention, the adhesive modified layer has the following four morphological and structural characteristics, and can be obtained by the following means.
(A) Microphase separation or nanophase separation into a polyester phase and a polyurethane phase, and they have a specific area ratio. (B) It is possible to change the composition ratio of the resin component of the adhesive modified layer on the surface and inside. Yes (c) When particles are included in the adhesion modified layer, the particles are unevenly distributed in the polyester phase or polyurethane phase

  In addition, the polyester phase mainly composed of copolymerized polyester observed on the surface of the adhesive modified layer preferably has a continuous structure having a maximum width of 1 μm and a length exceeding 1 μm, more preferably copolymerization. In this structure, the polyester phase and the polyurethane phase have a co-continuous structure. Within the range of the area ratio of the PEs phase on the surface of the adhesive modified layer, the polyester phase mainly composed of the copolyester has a fine continuous structure having a maximum width of 1 μm and a length exceeding 1 μm. Microscopically uniform adhesion can be obtained.

  In the polyester phase composed mainly of copolyester, the phase separation structure where the width exceeds 1 μm at the maximum is locally adhered to the functional layer such as hard coat layer, diffusion layer and prism layer. Inferior parts occur. If a portion having poor adhesion is present on the surface of the adhesive modified layer, it may lead to macroscopic peeling starting from that portion. In order to achieve a fine continuous structure with a maximum width of 1 μm for the polyester phase, it is important to appropriately select the time and heat setting conditions required to reach the maximum temperature in the heat setting zone from the transverse stretching zone. It is. In particular, if the time required from the transverse stretching zone to the zone where the maximum temperature is reached in the heat setting zone is too long, the phase separation of the adhesive modified layer will proceed too much, resulting in a polyester based on the copolyester. In the narrowest part of the phase width, the part exceeding 1 μm is scattered. Specific heat setting conditions for producing the adhesive modified base film will be described later.

  In order to control the phase separation structure on the surface of the final adhesion modified layer, the evaporation rate of the solvent in the drying step described later and the subsequent heat treatment are extremely important. By controlling the solvent evaporation rate in the drying step, the composition ratio of the polyester component and the polyurethane component on the surface of the adhesive property modification layer can be changed.

  For example, when a mixed solvent of water / isopropyl alcohol is used, the ratio of water increases in the solvent remaining on the surface in the late drying process under weak drying conditions. Therefore, the ratio of polyurethane having relatively high hydrophilicity on the surface of the adhesive modified layer is higher than when the adhesive modified layer is dried under strong conditions. Also, changing the coating amount brings about the same effect as controlling the evaporation rate of the solvent. That is, when the coating amount is increased, drying takes time, and the remaining solvent existing on the coating surface immediately before drying increases the ratio of water. That is, the ratio of the polyurethane component on the surface of the adhesive modification layer can be made higher than when the coating amount is small.

  In the stretching step and the heat setting treatment step, phase separation of the polyester component and the polyurethane component proceeds. However, when thermal crosslinking of one of the resins starts, the mobility of each phase is significantly reduced, and the progress of phase separation is suppressed. That is, the phase separation structure can be controlled by controlling the heating conditions in the stretching process and the heat setting process.

  As described above, the adhesion modification is achieved by controlling the ratio of the polyester / polyurethane adhesion-modified layer near the surface in the drying process and controlling the progress of phase separation in the stretching process and heat setting process. It becomes possible to strictly control the surface phase separation structure of the layers and the ratio of each phase existing near the surface of the adhesive property modification layer. In addition, by controlling the surface energy of the particles to be contained in the adhesive modification layer, the particles can be selectively applied to either the polyester phase mainly comprising the copolyester or the polyurethane phase mainly comprising the polyurethane. It can be unevenly distributed.

  The adhesive property modification layer contains copolymer polyester and polyurethane as main resin components. The copolyester alone has sufficient adhesion to the polyester base film, but is inferior to adhesion to the hard coat layer containing inorganic fine particles. Further, since it is a relatively brittle resin, it tends to cause cohesive failure with respect to impact during cutting.

  On the other hand, polyurethane alone is relatively excellent in adhesion to a hard coat layer containing inorganic fine particles. However, it is inferior in adhesiveness with a polyester base film. Furthermore, it is inferior to blocking resistance at the time of winding an adhesive property modification base film in roll shape. Therefore, the quality of a hard coat film or an optical functional film produced using an adhesive modified base film having an adhesive modified layer of a polyurethane alone system is remarkably lowered. In order to avoid such a problem, it is necessary to include a large amount of particles, a particle having a large particle diameter, or an increase in the content of particles in the adhesive property modification layer. As a result, since the haze of the film increases, it is not preferable as a base film for a hard coat film or an optical functional film that has a particularly strong demand for transparency.

(3-1) Preparation Step of Coating Solution Used for Forming Adhesive Modified Layer In the present invention, the adhesive modified layer is formed using a coating method. Materials used for the coating liquid are a resin and a dispersion medium or a solvent. In the present invention, the coating solution used for forming the adhesive property modification layer is preferably aqueous. Moreover, in this invention, it is preferable embodiment to use particle | grains and surfactant together with a resin component. Furthermore, additives such as antistatic agents, ultraviolet absorbers, organic lubricants, antibacterial agents, and photooxidation catalysts can be used as necessary. In addition, a catalyst may be added to the coating solution in order to promote the thermal crosslinking reaction of the resin. For example, various chemicals such as inorganic substances, salts, organic substances, alkaline substances, acidic substances and metal-containing organic compounds can be used. Substances can be used. Moreover, in order to adjust pH of aqueous solution, you may add an alkaline substance or an acidic substance. The coating solution is obtained by dispersing or dissolving the resin in a dispersion medium or solvent under stirring, and then using various additives as necessary in addition to the particles and surfactant to obtain a desired solid content concentration. Adjust until diluted.

  In order to uniformly disperse the resin component and particles of the coating solution, it is preferable to finely filter the coating solution in order to remove coarse particles aggregates and foreign matters such as dust in the process.

  There is no particular limitation on the type of filter medium for finely filtering the coating solution as long as it has the above-mentioned performance, and examples thereof include a filament type, a felt type, and a mesh type. The material of the filter medium for finely filtering the coating solution is not particularly limited as long as it has the above-described performance and does not adversely affect the coating solution. Examples thereof include stainless steel, polyethylene, polypropylene, and nylon.

  The filter medium for microfiltration of the coating liquid is preferably a filter medium having a filtration particle size (initial filtration efficiency: 95%) of 25 μm or less, more preferably a filter medium having a filtration performance of 5 μm or less, particularly preferably a filter medium having a filtration performance of 1 μm or less. is there. Most preferred is a method in which filters having different filtration performance are used in combination. When a filter medium having a filtration particle size exceeding 25 μm is used, removal of coarse aggregates tends to be insufficient. Therefore, the coarse aggregate that could not be removed by filtration spreads due to the orientation stress in the uniaxial or biaxial orientation process after coating and drying, and is recognized as an aggregate of 100 μm or more, which tends to cause optical defects.

The raw materials used for the coating solution will be described in detail below.
(A) Resin In the present invention, copolymerized polyesters (PEs) and polyurethane (PU) are used as the resin constituting the adhesive modification layer. The mass ratio of the copolymerized polyesters (PEs) and polyurethane (PU) in the coating solution based on the solid content is preferably (PEs) / (PU) = 70/30 to 30/70, particularly preferably 60/40 to 40. / 60. In addition, resin which comprises an adhesive property modification layer can also use together 3rd resin other than the said copolyester and polyurethane. Moreover, you may use a crosslinking agent together.

  In the present invention, the area ratio of the polyester phase on the surface of the adhesive modified layer and the mass ratio of the copolymerized polyester to the resin component of the adhesive modified layer do not correspond as shown in FIG. FIG. 6 clearly shows that the PEs surface fraction of the surface of the adhesive modified layer varies from 30 to 91% even when the mass ratio of the copolyester to the resin component of the adhesive modified layer is 50%. It shows. This suggests that the composition ratio of the copolyester and the polyurethane is different between the surface and the inside of the adhesive modified layer. That is, this suggests that the constituent ratio of the copolyester and the polyurethane can be arbitrarily controlled in the thickness direction of the adhesion modified layer.

  Moreover, the hardness index of the surface of an adhesive property modification layer can be 3.0-15.0 nm by making the ratio of copolyester and polyurethane in an adhesive property modification layer into the said range. When the surface hardness index of the adhesive modified layer is less than 3.0 nm, the adhesive modified layer becomes brittle. Therefore, after forming a functional layer such as a hard coat layer, a diffusion layer, a prism layer, etc. containing acrylic resin as a constituent component, it is sufficient for the shearing force during high-speed cutting in the processing step of high-speed cutting to a predetermined size. Adhesion is difficult to obtain. Also. When the surface hardness index of the adhesion modified layer exceeds 15.0 nm, the blocking resistance tends to be lowered. Furthermore, there exists a tendency for the applicability | paintability to a base film, adhesiveness, and solvent resistance to become inadequate.

  In the present invention, the phase separation structure of the water-dispersed copolyester component and the hydrophilic polyurethane component is presumed to be formed as follows. Both resin components mixed with a common solvent are uniformly dispersed or dissolved in the coating solution. After the coating on the PET film, the coated surface after the drying process is in a uniform state without a clear phase separation structure. Thereafter, a phase separation structure is developed by heat treatment in the stretching step and the heat setting treatment step. That is, it is separated into a phase mainly composed of copolymer polyester and a phase mainly composed of polyurethane. In addition, as the phase separation progresses, it is considered that the ratio of the copolyester component having a lower surface energy that is present near the surface of the adhesive modified layer increases.

(Copolymerized polyester)
The copolyester used in the adhesive modification layer used in the present invention preferably comprises an aromatic dicarboxylic acid component and a glycol branched with ethylene glycol as the glycol component. Examples of the branched glycol component include 2,2-dimethyl-1,3-propanediol, 2-methyl-2-ethyl-1,3-propanediol, and 2-methyl-2-butyl-1,3. -Propanediol, 2-methyl-2-propyl-1,3-propanediol, 2-methyl-2-isopropyl-1,3-propanediol, 2-methyl-2-n-hexyl-1,3-propanediol 2,2-diethyl-1,3-propanediol, 2-ethyl-2-n-butyl-1,3-propanediol, 2-ethyl-2-n-hexyl-1,3-propanediol, 2, Such as 2-di-n-butyl-1,3-propanediol, 2-n-butyl-2-propyl-1,3-propanediol, and 2,2-di-n-hexyl-1,3-propanediol. And the like.

  The molar ratio of the branched glycol component is preferably 10 mol%, particularly preferably 20 mol%, with respect to the total glycol component. On the other hand, the upper limit is preferably 80 mol%, more preferably 70 mol%, and particularly preferably 60 mol%. If necessary, diethylene glycol, propylene glycol, butanediol, hexanediol, 1,4-cyclohexanedimethanol or the like may be used in combination.

  As the aromatic dicarboxylic acid component, terephthalic acid and isophthalic acid are most preferred. Other aromatic dicarboxylic acids, in particular, aromatic dicarboxylic acids such as diphenylcarboxylic acid and 2,6-naltalenedicarboxylic acid may be added and copolymerized within a range of 10 mol% or less with respect to the total dicarboxylic acid component. Good.

  In the present invention, it is preferable to use a water-soluble or water-dispersible resin as the copolyester used as the resin component of the adhesive modified layer. Therefore, in addition to the dicarboxylic acid component described above, in order to impart water dispersibility to the polyester, it is preferable to use 5-sulfoisophthalic acid or an alkali metal salt thereof in the range of 1 to 10 mol%. Mention may be made of acid, 5-sulfoisophthalic acid, 4-sulfonaphthaleneisophthalic acid-2,7-dicarboxylic acid and 5- (4-sulfophenoxy) isophthalic acid or alkali metal salts thereof.

(Polyurethane)
It is preferable to use a water-soluble or water-dispersible resin for the polyurethane used for the adhesive modification layer. For example, a heat-reactive water-soluble urethane, which is a resin containing a block-type isocyanate group, in which a terminal isocyanate group is blocked with a hydrophilic group (hereinafter, abbreviated as a block).

  Examples of the isocyanate group blocking agent include phenols, alcohols, lactam oximes, or active methylene compounds containing bisulfites and sulfonic acid groups. The blocked isocyanate group makes the urethane prepolymer hydrophilic or water-soluble. When heat energy is applied to the resin in the drying process or heat setting process during film production, the blocking agent deviates from the isocyanate group, so the resin is a water-dispersible copolymer mixed in a self-crosslinked stitch. While fixing polyester, it reacts with the terminal groups of the resin. The resin under preparation of the coating solution is hydrophilic and has poor water resistance, but when the thermal reaction is completed by coating, drying and heat setting, the hydrophilic group of the urethane resin, that is, the blocking agent is released, so the water resistance is good. A coating film is obtained.

  Among the above blocking agents, bisulfites are most preferable from the viewpoint that the blocking agent is removed from the isocyanate group at the heat treatment temperature and heat treatment time in the film production process, and that it is industrially available. The chemical composition of the urethane prepolymer used in the above resin includes (1) an organic polyisocyanate having two or more active hydrogen atoms in the molecule, or at least two active hydrogen atoms in the molecule. Reaction of a compound having a molecular weight of 200 to 20,000, (2) an organic polyisocyanate having two or more isocyanate groups in the molecule, or (3) a chain extender having at least two active hydrogen atoms in the molecule It is a compound having a terminal isocyanate group, which is obtained by pre-loading.

  The compound (1) generally known is a compound containing two or more hydroxyl groups, carboxyl groups, amino groups or mercapto groups in the terminal or molecule, and particularly preferred compounds include polyethers. Examples thereof include polyols and polyetherester polyols. Examples of polyether polyols include, for example, compounds obtained by polymerizing ethylene oxide and alkylene oxides such as propylene oxide, styrene oxide and epichlorohydrin, or random polymerization, block polymerization, or addition polymerization to polyhydric alcohols. The obtained compound is mentioned.

  Examples of the polyester polyol and the polyether ester polyol mainly include linear or branched compounds. Polyvalent saturated or unsaturated carboxylic acids such as succinic acid, adipic acid, phthalic acid and maleic anhydride, or the carboxylic acid anhydride, ethylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, 1 Condensation with polyvalent saturated and unsaturated alcohols such as 1,6-hexanediol and trimethylolpropane, polyalkylene ether glycols such as relatively low molecular weight polyethylene glycols and polypropylene glycols, or mixtures of these alcohols Can be obtained.

  Furthermore, polyester polyols include polyesters obtained from lactones and hydroxy acids. Further, as the polyether ester polyol, polyether esters obtained by adding ethylene oxide or propylene oxide or the like to polyesters produced in advance can be used.

  Examples of the organic polyisocyanate (2) include isomers of toluylene diisocyanate, aromatic diisocyanates such as 4,4-diphenylmethane diisocyanate, aromatic aliphatic diisocyanates such as xylylene diisocyanate, isophorone diisocyanate and 4,4. Alicyclic diisocyanates such as 4-dicyclohexylmethane diisocyanate, hexamethylene diisocyanate, and aliphatic diisocyanates such as 2,2,4-trimethylhexamethylene diisocyanate, or a single or a plurality of these compounds and trimethylolpropane Examples thereof include polyisocyanates added in advance.

  Examples of the chain extender having at least two active hydrogens in (3) above include glycols such as ethylene glycol, diethylene glycol, 1,4-butanediol, and 1,6-hexanediol, glycerin, trimethylolpropane, And polyhydric alcohols such as pentaerythritol, diamines such as ethylenediamine, hexamethylenediamine, and piperazine, amino alcohols such as monoethanolamine and diethanolamine, thiodiglycols such as thiodiethylene glycol, and water. .

  In order to synthesize a urethane prepolymer, the reaction is usually carried out for 5 minutes to several hours at a temperature of 150 ° C. or less, preferably 70 to 120 ° C., by a single-stage or multi-stage isocyanate polyaddition method using the chain extender. Let The ratio of isocyanate groups to active hydrogen atoms can be freely selected as long as it is 1 or more, but it is necessary that free isocyanate groups remain in the obtained urethane prepolymer. Furthermore, the content of free isocyanate groups may be 10% by mass or less, but considering the stability of the urethane polymer aqueous solution after being blocked, it is preferably 7% by mass or less.

  The obtained urethane prepolymer is preferably blocked using bisulfite. Mix with aqueous bisulfite solution and allow reaction to proceed with good agitation for about 5 minutes to 1 hour. The reaction temperature is preferably 60 ° C. or lower. Thereafter, it is diluted with water to an appropriate concentration to obtain a heat-reactive water-soluble urethane composition. When the composition is used, it is prepared to have an appropriate concentration and viscosity. However, when heated to about 80 to 200 ° C., the bisulfite of the blocking agent is dissociated and the active isocyanate group is regenerated, so that the prepolymer A polyurethane polymer is produced by a polyaddition reaction that takes place within or between the molecules of the polymer, or has the property of causing addition to other functional groups.

  As an example of the resin (B) containing a block type isocyanate group described above, trade name Elastron manufactured by Daiichi Kogyo Seiyaku Co., Ltd. is typically exemplified. Elastolone is a compound in which an isocyanate group is blocked with sodium bisulfite, and is water-soluble due to the presence of a carbamoylsulfonate group having strong hydrophilicity at the molecular end.

(B) Solvent In the present invention, the solvent broadly includes not only a solution for dissolving a resin but also a dispersion medium used for dispersing the resin in a particulate form. In order to carry out the present invention, various solvents such as an organic solvent and an aqueous solvent can be used.

  The solvent used in the coating solution is preferably a mixed solution in which water and alcohols such as ethanol, isopropyl alcohol, and benzyl alcohol are mixed within a range of 30 to 50% by mass in the total coating solution. Furthermore, if it is less than 10 mass%, you may mix in the range which can dissolve organic solvents other than alcohol. However, the total of alcohols and other organic solvents in the coating solution is less than 50% by mass.

  When the addition amount of the organic solvent is less than 50% by mass with respect to the total solvent, there are advantages that the drying property is improved at the time of coating and drying, and the appearance of the coating layer is improved as compared with the case of water alone. When the addition amount of the organic solvent is 50% by mass or more with respect to the total solvent, the evaporation rate of the solvent is increased, and the concentration change of the coating solution is likely to occur during coating. As a result, the viscosity of the coating liquid is increased and the coating property is lowered, so that the appearance of the coating film may be deteriorated. Furthermore, due to the volatilization of the organic solvent, there is a high risk of fire and the like. Moreover, when the addition amount of the organic solvent is less than 30% by mass with respect to the total solvent, the ratio of water is relatively increased, and the highly hydrophilic polyurethane component is segregated near the surface of the adhesive modified layer. As a result, it is difficult to make the area ratio of the PEs phase on the surface of the adhesive modified layer, or the area ratio of the PU phase near the interface with the hard coat layer in the cutting surface of the adhesive modified layer within an appropriate range. .

(C) pH adjustment of coating liquid It is preferable that pH of the coating liquid used for adhesive-adhesive property layer formation by this invention is the range of 5-5. When the pH of the coating solution is less than 5, the area ratio of the PEs phase on the surface of the adhesive modified layer increases, or the area ratio of the PU phase near the interface with the hard coat layer on the cutting surface of the adhesive modified layer It tends to be small and inferior in adhesion. On the other hand, if the pH of the coating solution is 8 or more, depending on the type of particles, significant aggregation occurs, haze increases, and transparency is deteriorated, which is not preferable. The pH adjuster is not particularly limited as long as it does not adversely affect adhesion, blocking resistance, and coatability or can be ignored. For example, sodium bicarbonate or sodium carbonate can be used to increase the pH, and acetic acid or the like can be used to decrease the pH.

(D) Combined use of surfactants When the aqueous coating solution is applied to the surface of a thermoplastic resin film, a surfactant is generally used to improve the wettability of the film and uniformly apply the coating solution. Is used. In the present invention, a surfactant can be used as one of means for controlling the surface of the adhesive modified layer and the internal phase separation structure.

  The surfactant is not particularly limited as long as it has good coatability and an appropriate phase separation structure can be obtained on the surface or inside of the adhesion modified layer. Among the surfactants, a fluorosurfactant is suitable for obtaining good coatability with a small amount of addition. Furthermore, in order to make the area ratio of the PEs phase on the surface of the adhesive modified layer or the area ratio of the PU phase near the interface with the hard coat layer on the cutting surface of the adhesive modified layer, It is preferable to blend 0.01 to 0.18% by mass of the system surfactant or nonionic surfactant with respect to the coating solution.

  When an anionic surfactant is used, the compatibility with the above-described copolymerized polyester and polyurethane may be increased, and the phase separation structure defined in the present invention is difficult to obtain. The addition amount of the surfactant can be appropriately selected as long as it does not inhibit the adhesion with a functional layer such as a hard coat layer or a diffusion layer and can provide good coating properties. For example, in the case of a fluorinated surfactant, it is preferably 30 times or less from the critical micelle concentration with respect to pure water. When the critical micelle concentration is 30 times or more, the particles contained in the coating solution are likely to aggregate, so that the haze of the obtained laminated film is increased, and this is not particularly preferable as a base film for an optical functional film. In addition, the surfactant component may bleed out on the surface of the adhesive property modification layer and adversely affect the adhesion. On the other hand, good coatability cannot be obtained at a critical micelle concentration or less. In addition, it becomes difficult to control the area ratio of the PEs phase on the surface of the adhesive modified layer or the area ratio of the PU phase near the interface with the hard coat layer on the cut surface of the adhesive modified layer to an appropriate range. .

(Surfactant purification)
The surfactant used in the present invention is preferably a purified one. In general, surfactants on the market often contain a small amount of impurities. In particular, polyethylene glycol as an impurity may inhibit obtaining a good phase separation structure depending on the content thereof. In order to prevent this, it is preferable to use a purified surfactant that has been subjected to a pretreatment to remove impurities from the surfactant.

The pretreatment process for removing impurities is not particularly limited as long as the impurities can be removed without altering the surfactant. For example, the following method is mentioned.
A method in which at least a surfactant and polyethylene glycol are dissolved in an organic solvent that can be dissolved, allowed to stand at a low temperature, the surfactant as a main component is saturated and precipitated, and then filtered to take out the surfactant with improved purity. Is mentioned. In the case of a perfluoroalkylethylene oxide adduct surfactant, the purity of the surfactant is improved by dissolving it in isopropyl alcohol on a hot bath at 30 ° C. and allowing it to stand at 0 ° C. for about 24 hours, and then filtering out the precipitate. An active agent can be obtained.

(E) Particles The haze of the adhesion-modified base film is 1.5% or less, and a hard coat film or an optical functional film using the film is used in applications where transparency is highly required. Especially preferred. The haze is more preferably 1.0% or less. When the haze exceeds 1.5%, when the film is used for a lens film for LCD, a base film for backlight or the like, the sharpness of the screen is lowered, which is not preferable.

  In order to make the haze of the adhesive modified substrate film 1.5% or less, it is preferable not to contain particles in the thermoplastic resin film. When particles are not included in the thermoplastic resin film, scratch resistance, handling properties when winding into rolls and unwinding (sliding properties, running properties, blocking properties, air release of accompanying air during winding, etc.) In order to improve the above, it is preferable that a specific amount of particles having an appropriate size is contained in the adhesive modified layer to form appropriate irregularities on the surface of the adhesive modified layer.

  As the particles, particles having high affinity with copolymerized polyester or polyurethane are preferable, and it is preferable that there is a difference that the affinity for both is unevenly distributed in either phase. By unevenly distributing the particles in one of the phase-separated resins, the particles can be gathered moderately, and excellent blocking resistance can be obtained with the addition of relatively few particles, that is, without significantly increasing haze. is there.

  Particles to be included in the adhesive modified layer include calcium carbonate, calcium phosphate, amorphous silica, crystalline glass filler, kaolin, talc, titanium dioxide, alumina, silica-alumina composite oxide particles, barium sulfate, fluoride. Inorganic particles such as calcium, lithium fluoride, zeolite, molybdenum sulfide, mica, crosslinked polystyrene particles, crosslinked acrylic resin particles, crosslinked methyl methacrylate particles, benzoguanamine / formaldehyde condensate particles, melamine / formaldehyde condensate particles, polytetra Examples thereof include heat-resistant polymer particles such as fluoroethylene particles.

Among these particles, silica particles are preferable from the following points.
The first advantage is that a highly transparent film can be easily obtained because the refractive index is relatively close to that of the resin component of the adhesive modification layer. The second advantage is that the silica particles tend to be unevenly distributed in the phase-separated polyurethane phase, and the inherent property of the polyurethane resin is inferior in the blocking resistance of the polyurethane phase present on the surface of the adhesive modified layer. It is a point that can be complemented. This is presumably because the surface energy of the silica particles and polyurethane is closer to that of the copolyester and the affinity is high.

  The shape of the particles is not particularly limited, but particles that are close to spherical are preferable from the viewpoint of imparting easy slipperiness.

  The content of the particles in the adhesive modified layer is preferably 20% by mass or less, more preferably 15% by mass or less, and particularly preferably 10% by mass or less with respect to the adhesive modified layer. When the content of the particles in the adhesion modified layer exceeds 20% by mass, the transparency is deteriorated and the adhesion of the film tends to be insufficient. On the other hand, the lower limit of the content of the particles is preferably 0.1% by mass, more preferably 1% by mass, and particularly preferably 3% by mass with respect to the adhesive modification layer.

  In addition, two or more kinds of particles having different average particle diameters may be contained in the adhesion modified layer. Moreover, you may contain the same kind of particle | grains from which an average particle diameter differs. In any case, the average particle diameter and the total content of the particles may be in the above ranges. When applying the coating solution, it is preferable to arrange a filter medium so that the coating solution is precisely filtered immediately before coating in order to remove coarse aggregates of particles in the coating solution.

  The average particle diameter of the particles is preferably 20 to 150 nm, more preferably 40 to 60 nm. When the average particle size is less than 20 nm, it is difficult to obtain sufficient blocking resistance, and scratch resistance tends to deteriorate. On the other hand, if the average particle diameter of the particles exceeds 150 nm, the haze increases and the particles easily fall off.

  In the present invention, sufficient blocking resistance and scratch resistance may not be obtained with only particles A having an average particle diameter of 20 to 150 nm. Therefore, in order to further improve the blocking resistance and scratch resistance, it is preferable to use a small amount of particles B having a larger average particle size. The average particle size of the particles B having a large average particle size is preferably 160 to 1000 nm, particularly preferably 200 to 800 nm. When the average particle size of the particle B is less than 160 nm, scratch resistance, slipping property, and winding property may be deteriorated. On the other hand, when the average particle size of the particles B exceeds 1000 nm, the haze tends to increase. Further, the particle B is preferably an aggregate particle in which primary particles are aggregated, and it is possible to use a particle having a ratio of the average particle diameter in the aggregated state to the average particle diameter of the primary particle of 4 times or more. From the point of view, it is preferable.

  When two types of particles are used, for example, the content ratio (P1 / P2) of the particles A (average particle size: 20 to 150 nm) and the particles B (average particle size: 160 to 1000 nm) in the adhesion modified layer is 5 To 30 and the content of the particles B to 0.1 to 1% by mass with respect to the solid content of the adhesive modification layer. Controlling the content of the two kinds of particles with specific particle sizes within the above range optimizes the three-dimensional center plane average surface roughness of the surface of the adhesion modified layer, and improves transparency, handling properties and anti-blocking properties. It is suitable for achieving both properties. When the content of the particles B exceeds 1% by mass with respect to the adhesion modified layer, the haze tends to increase remarkably.

The average primary particle size and average particle size of the particles are measured by the following method.
Take a photograph of the particles with an electron microscope, measure the maximum diameter of 300-500 particles at a magnification such that the size of one smallest particle is 2-5 mm, and calculate the average value as the average primary particle size or Average particle diameter. In addition, when obtaining the average particle size of the particles in the adhesion modified layer of the laminated film, a cross section of the laminated film is photographed at a magnification of 120,000 using a transmission electron microscope (TEM) to improve the adhesion. The maximum diameter of the particles existing in the cross section of the layer can be determined. The average particle size of the particles B made of aggregates is obtained by taking 300 to 500 cross-sections of the adhesive modified layer of the laminated film at a magnification of 200 using an optical microscope, and measuring the maximum diameter.

(F) Crosslinking agent Opportunities for using information terminals outdoors, such as mobile phones, PDAs, and mobile computers, are increasing. In addition, materials used in cars that become hot in summer, such as touch panels used for car navigation, are increasing. Therefore, a hard coat film having little change in quality even under such a severe environment of high temperature and high humidity, that is, a film excellent in wet heat and heat adhesion is demanded for such applications.

  When the hard coat film of the present invention is used for such an application, in order to improve the moisture and heat resistance of the adhesion modified layer, a crosslinking agent is added to the coating solution, and then a heat treatment is performed, thereby having a crosslinked structure. An adhesion modified layer containing a resin is formed. As the crosslinking agent, at least one selected from an epoxy crosslinking agent, a melamine crosslinking agent, and an oxazoline crosslinking agent is used. The cross-linking agent can be selected in consideration of the affinity with the copolymerized polyester resin used in the coating solution and the moisture and heat resistance required for the adhesion modified layer.

  In particular, when a high degree of wet heat resistance is required, an epoxy-based crosslinking agent or a melamine-based crosslinking agent is preferable among the above-mentioned crosslinking agents. Although it does not specifically limit as an epoxy-type crosslinking agent, For example, the water-soluble epoxy crosslinking agent made from Nagase Kasei Kogyo Co., Ltd. (Deconal series; EX-521, EX-512, EX-421, EX-810, EX-811). , EX-851, etc.) are commercially available. Examples of the melamine-based crosslinking agent include Sumitomo Chemical's Smitex Resin Series (M-3, MK, M-6, MC, etc.) and Miwa Chemical Co., Ltd. methylated melamine resin (MW-22, MX). -706 etc.) are commercially available. Moreover, as an oxazoline-type crosslinking agent, Nippon Shokubai Epochros series (WS-700), Shin-Nakamura Chemical Co., Ltd. NX Linker FX, etc. are available as a commercial item.

  The cross-linking agent is preferably 5 to 40% by mass, more preferably 10 to 30% by mass, based on the total amount (100% by mass) of the copolyester resin and the cross-linking agent in the adhesive modification layer. Is preferably contained in the coating solution for forming an adhesive modification layer. If the content of the cross-linking agent exceeds 40% by mass, the adhesive modification layer becomes brittle, and high-speed cutting is possible in the processing step after forming a functional layer such as a hard coat layer or a diffusion layer made of an acrylate resin. In some cases, sufficient adhesion cannot be obtained. On the other hand, if the content of the crosslinking agent is less than 5% by mass, it may be difficult to obtain durability required in recent years. In the coating solution, a catalyst may be added as necessary to promote crosslinking.

(3-2) Application Step The step of applying the aqueous coating solution is preferably an in-line coating method applied during the production process of the film. More preferably, it is applied to the base film before the crystal orientation is completed. The solid content concentration in the aqueous coating solution is preferably 30% by mass or less, and particularly preferably 10% by mass or less. The lower limit of the solid content concentration is preferably 1% by mass, more preferably 3% by mass, and particularly preferably 5% by mass. Coating amount of the aqueous coating solution The film coated with the aqueous coating solution is led to a tenter for orientation and heat setting, and heated there to form a stable film by a thermal cross-linking reaction. It becomes.

(Amount of application)
The coating amount when not dried (hereinafter abbreviated as wet coating amount) is preferably ² g / m ² or more and less than 10 g / m ² . If the wet coating amount is less than 2 g / m ² and an attempt is made to obtain the designed dry coating amount (the coating amount of the final adhesion modified layer), it is necessary to increase the solid content concentration of the coating solution. When the solid content concentration of the coating solution is increased, the viscosity of the coating solution is increased, so that streaky coating spots are likely to occur. On the other hand, when the wet coating amount is 10 g / m ² or more, it is easy to be affected by the drying wind in the drying furnace, and coating spots are likely to occur. In order to prevent defects due to dust adhesion, it is preferable to apply the coating liquid in a clean environment with a cleanness of class 5000 or less.

Moreover, it is preferable to manage the coating amount (solid content mass per film unit area) of the final adhesive property modification layer at 0.005 to 0.20 g / m ² . In the prior art, when the coating amount is less than 0.05 g / m ^2, it is difficult to obtain sufficient adhesion. However, the adhesive modified layer has a specific phase separation structure, so that even if the coating amount is less than 0.05 g / m ² , a laminated film having excellent adhesion to the functional layer and the substrate can be obtained. It is done. If the coating amount is less than 0.005 g / m ² , the adhesion will be insufficient. When the coating amount is less than 0.05 g / m ^2, it is preferable to use particles having an average particle size of 60 nm or less. When the average particle diameter of the particles exceeds 60 nm, the particles easily fall off from the adhesive modified layer during the production or processing of the adhesive base film. When the particles are unevenly distributed in the polyurethane phase, the particles are difficult to fall off if the coating amount is 0.005 g / m ² or more. On the other hand, when the coating amount exceeds 0.20 g / m ² , the polyurethane component segregated on the surface of the adhesive property modification layer increases, and the blocking resistance is lowered.

The thickness of the adhesive modified layer can be measured by cutting the cross section of the adhesive modified layer with a microtome and observing with an electron microscope. However, if the adhesive modified layer is soft, it may be deformed during cutting. is there. For simplicity, if the coating amount is known, the thickness can be converted from the density of the adhesive property modified layer. For example, when the density of the adhesive modified layer is 1 g / cm ³ , the thickness corresponds to 1 μm if the coating amount is 1 g / m ² . The density of the adhesive modified layer is determined by calculating the density of each material from the type of resin and particles constituting the adhesive modified layer, multiplying the density of each material by the mass ratio of the material, and determining the sum. The thickness of the property modifying layer can be estimated.

(3-3) Drying step In the method for producing an adhesion-modified base film, after a coating liquid is applied to the thermoplastic resin film, the thinly applied coating film is dried. Generally, when the coating film is dried after the coating solution is applied, it is often dried using a preheating zone of a tenter. In this case, although it depends on the size of the film-forming equipment and the traveling speed of the film, it generally takes at least about 5 seconds from application to drying. During this time, the balance between water and alcohol as the solvent of the coating solution is lost, and the highly hydrophilic polyurethane component is likely to segregate on the surface of the adhesive modified layer. Therefore, in the finally obtained adhesive modified base film, the area ratio of the PEs phase on the surface of the adhesive modified layer, or the PU phase near the interface with the hard coat layer on the cutting surface of the adhesive modified layer It is difficult to control the area ratio within an appropriate range. In the present invention, it is important to place a drying oven (pre-dryer) dedicated to drying the coating film as close as possible to the exit of the coating device in the film traveling direction, and to dry the coating liquid immediately after coating the polyester film. It is.

  In the drying furnace, the temperature of the drying air on the coated surface is preferably 120 ° C. or higher and lower than 150 ° C. The wind speed is preferably 30 m / second or more. A more preferable drying temperature is 130 ° C. or higher and lower than 150 ° C. When the drying temperature is less than 120 ° C. or the wind speed is less than 30 m / sec, the drying speed becomes slow, the balance between water and alcohol as the solvent of the coating solution is lost, and the ratio of water is relatively likely to increase. Therefore, a highly hydrophilic polyurethane component is segregated on the surface of the adhesive modification layer. Therefore, in the finally obtained adhesive modified base film, the area ratio of the PEs phase on the surface of the adhesive modified layer, or the PU phase near the interface with the hard coat layer on the cutting surface of the adhesive modified layer It is difficult to control the area ratio within a proper range. On the other hand, when the drying temperature is 150 ° C. or higher, crystallization of the thermoplastic resin film is likely to occur, and the frequency of breakage during transverse stretching increases.

  Moreover, in the said drying furnace, it is preferable to dry for 0.1 to 5 second, maintaining temperature at 120 to 150 degreeC. The drying time is more preferably 0.5 to 3 seconds. When the drying time is less than 0.1 seconds, the coating film is not sufficiently dried, and the roll is contaminated with an insufficiently dried coating surface when passing through the roll disposed between the drying process and the transverse stretching process. It becomes easy to do. On the other hand, when the drying time exceeds 5 seconds, crystallization of the thermoplastic resin film is likely to occur, and the frequency of breakage during transverse stretching increases.

  It is preferable that after the coating film is dried at a temperature of 120 ° C. or higher and lower than 150 ° C. in the drying furnace, the adhesive modified base film having the adhesive modified layer is immediately cooled to near room temperature. When the adhesive modified base film comes out of the drying oven with the surface temperature of the above-mentioned adhesive modified base film at a high temperature of 100 ° C. or higher and comes into contact with a roll near room temperature, scratches are generated due to the shrinkage of the film. It becomes easy.

  When the wind speed in the drying furnace is usually 30 m / second or more, drying unevenness is likely to occur because strong drying air is applied to the undried coated surface in the drying furnace. However, in the present invention, it is possible to perform at a wind speed of 30 m / sec or more by exhausting the air volume equal to or greater than the air volume to be blown out of the drying furnace. It is also important that the exhaust air flow to the opposite side of the coater to prevent unevenness on the coating surface due to the exhaust air at the coater.

  It is important that the transit time of the film from immediately after coating to entering the drying furnace is less than 2 seconds, preferably less than 1.5 seconds. If the time from application to the drying oven is 2 seconds or more, the balance between water and alcohol, which are the solvent of the coating solution, is lost during this time, so that a highly hydrophilic polyurethane component is applied to the surface of the adhesive modified layer. It becomes easy to segregate. Therefore, the finally obtained adhesive modified base film has an area ratio of PEs phase on the surface of the adhesive modified layer or a PU near the interface with the hard coat layer on the cutting surface of the adhesive modified layer. It becomes difficult to control the phase area ratio within an appropriate range.

  In order to maintain the passage time of the film from immediately after coating to entering the drying furnace to less than 2 seconds, it is necessary to appropriately select the traveling speed of the film, but it is preferable to make the coater and the drying furnace inlet as close as possible. . In the drying furnace, it is preferable to use air cleaned with a HEPA filter in order to prevent dust from being mixed in from the drying air. As the HEPA filter used at this time, a filter having a performance of cutting 95% or more of dust having a nominal filtration accuracy of 0.5 μm or more is preferably used.

  The drying step is preferably composed of a drying zone divided into so-called 2 to 8 zones in which drying temperature and drying time conditions are sequentially changed. Particularly preferably, a multistage drying apparatus divided into 3 to 6 zones is employed. For example, when the coating solution is applied to one or both sides of a uniaxially oriented thermoplastic resin film and dried in a multistage drying furnace disposed directly above the coater, the following method is suitable.

  For example, when drying is performed in four stages, drying is performed in a drying furnace divided into four drying zones. In the first drying zone, the temperature is 125 to 140 ° C. for 0.1 to 4 seconds, in the second drying zone, the temperature is 55 to 100 ° C. for 0.1 to 4 seconds, and in the third drying zone, the temperature is 35 to 55 ° C. In the fourth drying zone for 0.1 to 4 seconds, a method of drying at a temperature of 25 to 35 ° C. for 0.1 to 4 seconds can be mentioned.

  The numerical range of the drying conditions varies somewhat depending on the solid content concentration of the coating solution, and is not limited to the above typical conditions. Furthermore, when performing hot air drying, it is important that the air volume also changes at each stage.

For example, the following method is suitable.
In the first drying zone, the wind speed of the drying air to 20 to 50 m / sec, the supply air volume of the drying air 100-150 ³ / sec, setting the exhaust air volume to 150 to 200 m ³ / sec. From the second drying zone to the fourth drying zone, the supply air volume is set to 60 to 140 m ³ / sec, and the exhaust air volume is set to 100 to 180 m ³ / sec. In any drying zone, set so that the drying air does not flow to the coater side, and then grip the end of the film with a clip to make a hot air zone at a temperature of 100 to 140 ° C. and a wind speed of 10 to 20 m / sec. Guide and stretch 2-6 times in the width direction.

  Further, while maintaining the temperature at 120 to 150 ° C., the drying temperature and the total drying time may be appropriately adjusted for 0.1 to 5 seconds, preferably 0.5 to less than 3 seconds. Each step (zone) in the drying process is determined appropriately at the manufacturing site in consideration of various conditions such as the concentration of the dispersion, the coating amount, the traveling speed of the coated traveling film, the temperature of the hot air, the wind speed, and the amount of air. The appropriate value can be determined.

(3-4) Heat setting treatment step In the method for producing an adhesion-modified base film, the transverse stretching step, the heat setting treatment step, and the cooling step are continuously divided into 10 to 30 zones, and each zone is independent. Thus, it is partitioned so that temperature control is possible, and it is designed so that rapid temperature change does not occur between the zones. In particular, a rapid temperature change between adjacent zones can be suppressed by raising the temperature stepwise from the latter half of the transverse stretching zone to the heat setting maximum temperature setting zone. In the present invention, when manufacturing an adhesive modified base film having a specific phase separation structure on the surface or inside of the adhesive modified layer, temperature control is very important especially in the drying process and the heat setting process. is there. In addition, in order to form a crosslinked structure in the resin constituting the adhesion modified layer, the temperature in the heat setting treatment step is very important, and this temperature greatly affects the crosslinking reaction rate.
Hereinafter, the embodiment will be described in detail.

  As described above, in the heat setting treatment step, the heat treatment condition determines the phase separation state of the adhesive property modified layer. That is, it takes to reach the maximum temperature in the heat fixing treatment step from the maximum temperature in the heat fixing treatment step, the time required to reach the maximum temperature, and the temperature at which phase separation of the adhesive reforming layer starts to proceed remarkably. It is important to set the time appropriately.

  The temperature in each heat setting zone in the heat setting treatment step may be appropriately set within a temperature range of 100 to 260 ° C., although there is a slight difference depending on the type of resin constituting the thermoplastic resin film. Hereinafter, a case where polyethylene terephthalate, which is a typical thermoplastic resin, is used as a thermoplastic resin film will be described as an example.

  The maximum temperature in the heat setting treatment step is preferably controlled at 210 to 240 ° C, more preferably the lower limit is 225 ° C and the upper limit is 235 ° C. In general, heat fixing is performed at a relatively high temperature of 210 to 240 ° C. in the initial stage of the heat setting treatment, and the temperature is often gradually decreased to 100 to 200 ° C. in the subsequent stage.

  When the maximum temperature in the heat setting treatment step is less than 210 ° C., it is difficult to form a microphase separation structure or a nanophase separation structure in the adhesion modified layer. Therefore, it becomes difficult to obtain sufficient adhesion between the base material and the functional layer, which can withstand the peeling of the interface due to the impact during high-speed cutting, which is required in recent years. Furthermore, the heat-shrinkage rate of the obtained adhesive modified base film becomes large, which is not preferable.

  When the maximum temperature in the heat setting process exceeds 240 ° C., the PEs surface fraction on the surface of the adhesive modification layer increases, and printing is performed with a hard coat layer, a diffusion layer, a prism layer, and an ultraviolet curable ink. Adhesiveness to a functional layer such as a printed layer is likely to decrease. Furthermore, since the time required to reach the maximum temperature of the heat setting treatment from the temperature at which the phase separation of the adhesive modified layer starts to proceed remarkably increases, the narrowest part of the polyester phase mainly composed of the copolyester It will be in the state where the location where a width | variety exceeds 1 micrometer is scattered. As a result, a part having poor adhesion is generated on a functional layer such as a hard coat layer, a diffusion layer, a prism layer, or a printing layer printed with ultraviolet curable ink locally, and macroscopic peeling starts from that part. May lead to.

Specifically, the time required to reach the maximum temperature of the heat setting treatment from the temperature at which the phase separation of the adhesive modified layer starts to proceed remarkably is preferably set as follows.
In the present invention, the passage time of the film from the temperature setting zone at which the phase separation of the adhesive modified layer starts to proceed remarkably to the maximum temperature setting zone inlet of the heat setting treatment process is 3 seconds or more and less than 20 seconds. Preferably, it is 4 seconds or more and less than 15 seconds.

  If the passage time is less than 3 seconds, the time for developing the phase separation structure defined in the present invention may be insufficient. On the other hand, when the passage time is 20 seconds or more, the phase separation proceeds excessively, and the thinnest portion of the phase mainly composed of the copolyester tends to be dotted with portions having a width exceeding 1 μm. As a result, a portion having poor adhesion to a functional layer such as a hard coat layer, a diffusion layer, a prism layer, or a printing layer printed with UV ink is locally generated, which may lead to macroscopic peeling starting from that portion. is there.

  In the present invention, the temperature at which the phase separation of the adhesive property modified layer starts to progress remarkably is estimated to be about 200 ° C. within the composition range of the coating liquid shown in the examples of the present invention. However, the temperature is naturally not limited to this temperature because it varies depending on the resin component of the adhesive modification layer.

The heat setting process will be described more specifically.
In general, the transverse stretching process, heat setting process, and cooling process are divided into 10 to 30 zones in the tenter in order to suppress a rapid temperature change in each adjacent zone, and temperature control is independently performed in each zone. Has been made. In particular, in the zone set to the maximum temperature of the heat setting treatment process from the latter half of the transverse stretching zone, the temperature of each zone is increased stepwise with respect to the film advancing direction, and the temperature between each heat setting zone is rapidly increased. It is preferable that no significant temperature change occurs.

  In the present invention, it is important to quickly and uniformly raise the passage time of the film from the temperature setting zone where the phase separation starts to proceed remarkably to the maximum temperature setting zone entrance of the heat setting treatment step. . In order to quickly raise the temperature, a method of increasing the heat transfer efficiency in each heat setting zone, for example, a method of increasing the speed of hot air blown to the film is effective. However, in this method, temperature spots generally tend to occur. Therefore, in the case where spots are generated in the phase separation state of the adhesive modified layer, or foreign matters such as oligomers slightly adhered in the apparatus in the heat setting zone. May rise, and the raised foreign matter may adhere to the film and lead to optical defects.

  On the other hand, if the wind speed is too low, a sufficient heating rate cannot be obtained. Therefore, in the present invention, the wind speed is preferably set to 10 m / second or more and less than 20 m / second. In order to quickly and uniformly raise the temperature of the laminated film, it is effective to arrange the nozzles for blowing hot air at relatively short intervals of 500 mm or less. In the case where the nozzle spacing for blowing hot air is set to 500 mm or less, for example, when the nozzle spacing is set to 300 mm, 350 mm, or 400 mm, it is disadvantageous for equipment maintenance, but it is important for completing the present invention. . The number of nozzles per zone corresponding to one stage is about 6 to 12, and the number is determined in consideration of the state of the nozzle interval, the amount of ventilation, and the ventilation time. In addition, the wind speed described by this invention means the wind speed in the film surface which faced the hot air blowing nozzle exit, and was measured using the thermal-type anemometer (Nippon Kanomax make, Anemomaster model 6161).

The preferable one embodiment of the heat setting process at the time of manufacturing an adhesive property modification base film is shown.
The heat setting process is divided into a plurality of heat setting zones continuously, and each zone is partitioned so that the temperature can be controlled independently. The heat setting zone is divided into a process in which 2 to 10 steps of heat setting zones are continuously arranged, preferably 4 to 8 steps, and this heat setting zone is divided into multi-stages. It is preferable to control the temperature of the material film.

  For example, in the case of a polyester film having an adhesion modified layer, the heat setting process is performed by sequentially passing through a heat setting zone divided into six stages as shown below, with a subtle temperature difference at each stage. And a method of trimming uncoated portions at both ends of the film. The heat setting treatment temperature is 200 ° C. in the first heat setting zone, 225 ° C. in the second heat setting zone, 230 ° C. in the third heat setting zone, 230 ° C. in the fourth heat setting zone, and in the fifth heat setting zone. 210 ° C., 170 ° C. in the sixth heat setting zone, and 120 ° C. in the seventh heat setting zone. In addition, 3% relaxation treatment is performed in the width direction in the sixth heat fixing zone.

  Said stage corresponds to one heat setting zone. Thus, it is preferable to give a subtle temperature difference to the temperature of the heat setting zone of each stage, that is, to give a temperature difference of about 5 to 40 ° C. The setting of this temperature difference is arbitrarily determined in consideration of various factors such as the running speed of the thermoplastic resin film having the adhesive modified layer, the air volume, and the thickness of the adhesive modified layer.

  When used as a base film of an optical functional film such as a lens film or a diffusion plate, the film length is usually at least 1000 m or more and sometimes 2000 m or more even if the film thickness is a relatively thick film of 100 μm or more. In the form wound up in a roll shape, it is subjected to a processing step of laminating a prism layer and a diffusion layer.

  In the present invention, the area ratio of the PEs phase (showing a dark hue in the phase image) on the surface of the adhesive modified layer, or the area of the PU phase near the interface with the hard coat layer on the cut surface of the adhesive modified layer When the ratio (indicating a bright hue in the phase image) is measured at 100 m intervals in the longitudinal direction of the film, the difference between the maximum value and the minimum value of the area ratio in the longitudinal direction is preferably 15% or less. Preferably it is 10% or less. By setting the difference between the maximum value and the minimum value of the area ratio in the longitudinal direction to 15% or less, an adhesive modified base film roll having stable adhesion and blocking resistance can be obtained.

  In order to control the difference between the maximum value and the minimum value of the area ratio in the longitudinal direction to 15% or less, the film forming conditions such as the composition of the coating liquid, the coating conditions, the drying conditions, and the heat setting conditions are set as follows. It is important to keep it constant during continuous production of the long adhesive modified substrate film roll used in the invention. However, in particular, the ratio of the mixed solvent used in the coating solution is likely to fluctuate, and the idea of keeping this mixed solvent ratio constant is the area ratio of the PEs phase on the surface in the longitudinal direction of the film roll and the area of the PU phase on the cutting surface. This is important in reducing rate fluctuations. For example, the fluctuation range of the area ratio of the PEs phase on the surface of the adhesive modified layer and the area ratio of the PU phase on the cutting surface can be controlled to 15% or less by the following means. The means for keeping the ratio of the mixed solvent constant is not limited to the following method.

  Increasing the capacity of the circulation tank (13 in FIG. 7) relative to the capacity of the coating solution receiving tray (11 in FIG. 7) is effective in stabilizing the concentration ratio of the mixed solvent. Specifically, as shown in FIG. 7, when the capacity of the receiving tray of the coating liquid is 1, the ratio of the capacity of the circulation tank is preferably 10 or more, particularly preferably 50 or more. When the volume ratio (capacity of the circulation tank / capacity of the coating liquid tray) is less than 10, that is, the capacity of the circulation tank is too small, the variation in the concentration ratio of the mixed solvent tends to increase.

  Furthermore, when the capacity of the circulation tank is 1, the ratio of the capacity of the preparation tank (14 in FIG. 7) is preferably 10 or more, particularly preferably 20 or more. Thereby, when supplying a coating liquid from the tank for preparation to the tank for circulation, the capacity of the tank for circulation can be always kept constant during operation.

  In addition, increasing the accuracy (roundness and cylindricity) of the applicator roll in the coating apparatus is also effective from the point of reducing coating thickness unevenness of the adhesive modified layer in the longitudinal direction of the film roll. Furthermore, it is also effective in reducing fluctuations in characteristics due to fluctuations in the area ratio of the PEs phase on the surface of the adhesive reforming layer or the PU phase area of the cutting surface in the longitudinal direction of the film roll.

  The roundness of the applicator roll is expressed by the difference between the radii of two concentric circles by the minimum area method determined by using a recorded roundness measuring instrument as shown in JIS B 0621. It is an indicator. The unit of roundness of the roll is mm. In addition, the cylindricality of the applicator roll can be measured in various measurement planes over the entire length by moving the stand with a measuring instrument on the surface plate in the axial direction and placing the probe on the upper surface of the cylinder. This is an index represented by ½ of the maximum difference in reading at the time of measurement. The unit of cylindricity is mm.

  In the present invention, by improving the roll accuracy (roundness and cylindricity), variation in the thickness of the coating layer in the length direction can be reduced. Specifically, the roll accuracy (roundness and cylindricity) is preferably less than 5/1000 mm.

  In addition, when applying the coating liquid, the surface finish of each roll of the reverse coater is 0.3 S or less, and the accuracy (roundness and cylindricity) of the applicator roll and the metering roll is less than 5/1000 mm, 2/1000 mm By setting it as the above, the fluctuation | variation of the wet application quantity can be suppressed and the fluctuation | variation of the thickness of a coating film can also be suppressed. It is preferable to use a coating roll in which the accuracy (roundness and cylindricity) of the applicator roll and the metering roll is 3/1000 mm.

  Further, by setting the tension of the film to 4000 to 10,000 N / raw width (raw width is 1 to 2 m), the flatness of the film is maintained on an industrial scale, and the transfer amount of the coating liquid becomes uniform. The tension of the film varies depending on the thickness of the film, and the flatness is maintained by applying a lower tension to a relatively thin film.

  If the tension of the film exceeds 10,000 N / raw width, the film may be deformed or broken. On the other hand, if the tension of the film is less than 4000 N / raw width, the flatness of the film at the time of coating may be insufficient, or the film may meander. As a result, the transfer amount of the coating liquid becomes non-uniform in the length direction of the film, and the variation in the thickness of the coating layer becomes larger due to the large variation in the wet coating amount of the film.

  In order to control the fluctuation of the area ratio of the PEs phase on the surface or the PU phase on the cutting surface (difference between the maximum value and the minimum value) to 10% or less in the width direction of the film roll. It is important to reduce the variation in the thickness of the coating layer with respect to the width direction of the film roll. For this purpose, it is effective to improve the flatness in the width direction during coating. Specifically, immediately after coating with a reverse roll, only both end faces of the film are gripped using a pinch roll (16 in FIG. 7). By causing the pinch roll to grip both ends of the film, the flatness in the width direction of the film is improved on an industrial scale, and the wet coating amount in the width direction of the film is stabilized. Thereby, the fluctuation | variation of the thickness of the application layer in the width direction of a film roll can be reduced. When the both ends of the film are not held with a pinch roll, the wet coating amount in the width direction and the length direction of the film varies greatly, and the variation in the thickness of the coating layer also increases.

(4) Hard coat layer and other optical functional layers The hard coat film of the present invention has an adhesive property in which an adhesive modified layer B containing a copolymerized polyester and polyurethane is formed on one side or both sides of a thermoplastic resin film A. A / B / C or B / A / B / C layer structure in which a modified base film and a hard coat layer C containing inorganic fine particles are laminated on one side of an adhesion modified layer B of the film It is a hard coat film containing. The curable resin constituting the hard coat layer is preferably an ionizing radiation curable resin. Examples of the ionizing radiation curable resin include the following resins.

  The ionizing radiation curable resin is preferably a resin having an acrylate functional group, and particularly preferably a polyester acrylate or a urethane acrylate. The polyester acrylate is composed of a polyester polyol oligomer acrylate or methacrylate (hereinafter, acrylate and / or methacrylate may be referred to as (meth) acrylate), or a mixture thereof. Moreover, urethane (meth) acrylate is comprised from what formed the oligomer which consists of a polyol compound and a diisocyanate compound into (meth) acrylate.

  As monomers constituting (meth) acrylate, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, methoxyethyl (meth) acrylate, butoxyethyl ( And (meth) acrylate and phenyl (meth) acrylate.

  Further, when it is necessary to further increase the hardness of the hard coat layer, it is preferable to use a polyfunctional monomer in combination. For example, as the polyfunctional monomer, trimethylolpropane tri (meth) acrylate, hexanediol (meth) acrylate, tripropylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipenta Examples include erythritol hexa (meth) acrylate, 1,6-hexanediol di (meth) acrylate, and neopentyl glycol di (meth) acrylate.

  Examples of polyester polyol oligomers include adipic acid and glycol (ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, butylene glycol, polybutylene glycol, etc.) and triol (glycerin, trimethylolpropane, etc.), sebacic acid, glycol and triol. And a polyadipate polyol and a polysebacate polyol which are condensation products. In addition, some or all of the aliphatic dicarboxylic acids can be replaced with other organic acids. For example, isophthalic acid, terephthalic acid, or phthalic anhydride can be used as a component that increases the hardness of the hard coat layer.

  When applying the hard coat agent to the surface of the adhesion modified layer of the base film, it may be diluted with a diluent as necessary in order to improve the leveling property. Examples of the diluent include aromatic hydrocarbons such as benzene, toluene and xylene, aliphatic hydrocarbons such as hexane, heptane, octane, nonane and decane, and ketones such as methyl ethyl ketone, diethyl ketone and diisopropyl ketone. What is necessary is just to select the compounding quantity of a diluent suitably so that it may become a suitable viscosity.

  Examples of the inorganic fine particles to be contained in the hard coat layer C include, for example, amorphous silica, crystalline glass filler, silica, zirconium oxide, titanium dioxide, alumina, and other inorganic oxides, silica-alumina composite oxide particles, carbonic acid Examples thereof include magnesium, aluminum hydroxide, barium sulfate, calcium carbonate, calcium phosphate, kaolin, talc, barium sulfate, calcium fluoride, lithium fluoride, zeolite, molybdenum sulfide, and mica.

  When an antireflection layer composed of a high refractive index layer / low refractive index layer or a high refractive index layer / medium refractive index layer / low refractive index layer is laminated on the surface of the hard coat layer C, the hard coat layer C is By increasing the refractive index, the high refractive index layer can be omitted from the antireflection layer. As a result, cost can be reduced. In order to increase the refractive index of the hard coat layer C, it is effective to contain inorganic fine particles having a high refractive index in the hard coat layer. Examples of the inorganic fine particles having a high refractive index include zirconium oxide and titanium oxide.

  It is important that the content of the inorganic fine particles in the hard coat layer is 20% by mass or more and 80% by mass or less. When the content of the inorganic fine particles is less than 20% by mass, the scratch resistance is insufficient. On the other hand, when the content of the inorganic fine particles exceeds 80% by mass, the transparency tends to decrease. The average particle size of the inorganic fine particles is preferably 5 to 100 nm from the viewpoint of transparency. However, such inorganic fine particles having a small average particle diameter are likely to aggregate and are unstable. Therefore, in order to improve the dispersion stability of the inorganic fine particles, it is preferable to add a photosensitive group to the surface of the inorganic fine particles to increase the affinity with the curable resin.

  Commercially available hard coat agents containing such inorganic fine particles are available. For example, an ultraviolet curable resin (Desolite; Z7400A, Z7410A, Z7400B, Z7410B, Z7400C, Z7410C, Z7410D, Z7410E, Z7501, Z7503, Z7521, Z7527) manufactured by JSR Corporation may be used.

The ionizing radiation curable resin is cured by irradiation with ultraviolet rays or electron beams. When irradiating with ultraviolet rays, use an ultra-high pressure mercury lamp, a high-pressure mercury lamp, a low-pressure mercury lamp, a carbon arc, or a metal halide lamp, and irradiate ultraviolet rays with an energy of 100 to 3000 mJ / m ² in a wavelength region of 100 to 400 nm, preferably 200 to 400 nm. Irradiate. In the case of irradiating an electron beam, a scanning or curtain type electron beam accelerator is used to irradiate an electron beam having an acceleration voltage of 1000 keV or less, preferably 100 to 300 keV and having a wavelength region of 100 nm or less.

  What is necessary is just to determine the thickness of a hard-coat layer according to a use in the range of 0.1-30 micrometers. More preferably, it is 1-15 micrometers. When the thickness of the hard coat layer is within the above range, the hardness of the surface of the hard coat layer is high and scratches are hardly caused. Furthermore, the hard coat layer is difficult to become brittle, and the hard coat layer is hardly cracked when the hard coat film is folded.

Next, the optical functional film described in the present invention is a film in which an optical functional layer is laminated on or opposite to the hard coat layer C of the hard coat film of the present invention. There is a form.
(A) At least one optical functional layer selected from a hard coat layer, a light diffusing layer, a prismatic lens layer, an electromagnetic wave absorbing layer, a near-infrared shielding layer, and a transparent conductive layer on the surface opposite to the hard coat layer C An optical functional film with laminated layers.
(B) An optical functional film in which an antireflection layer or an antifouling layer is laminated on the hard coat layer C.

  A lens film using a lens layer as an optical functional layer and a light diffusion film using a light diffusion layer will be described below as representative examples.

(Lens film)
The prism lens film or the Fresnel lens film is an ionizing radiation curable hard coat layer containing inorganic fine particles on one side of an adhesive modified base film having an adhesive modified layer mainly composed of copolymer polyester and polyurethane. And a prism lens layer or a Fresnel lens layer on the opposite surface. Although the lens film may be called a lens sheet, in the present invention, the sheet is also included in the film.

Next, the active energy ray-curable resin component constituting the prism lens layer will be described.
As the active energy ray curable resin component, at least one monomer or oligomer that can be radically polymerized determines the performance of the produced lens sheet, and is appropriately selected according to the performance of the target lens film.

  As the resin component, a radically polymerizable monomer or oligomer is used alone or in combination of two or more. In particular, when two or more resins are used, the mechanical strength, impact resistance, heat resistance, surface hardness, and chemical resistance required for the lens film can be imparted. In addition, by using 60 parts by mass or more of a compound having an acryloyl group or a methacryloyl group as a radical polymerizable functional group, the composition is partially copolymerized when irradiated with active energy rays, and instantly becomes insoluble. Fluidize. Therefore, optical distortion due to convection is reduced when the lens layer is formed.

  Resin components include ester-type (meth) acrylates obtained by condensation reaction of aliphatic, alicyclic, and aromatic mono- or polyalcohols with acrylic acid or methacrylic acid, and two or more isocyanates in the molecule. Urethane poly (meth) acrylate obtained by urethanation reaction of an isocyanate compound having a group with a hydroxyl group or a (meth) acrylate containing a thiol group, a compound having at least two epoxy groups in the molecule, and acrylic Polyester obtained by condensation reaction with epoxy poly (meth) acrylate obtained by glycidyl group ring-opening reaction with acid or methacrylic acid, saturated or unsaturated polycarboxylic acid, polyhydric alcohol, and (meth) acrylic acid ( (Meth) acryloyl functional monomers such as (meth) acrylate, oligo Chromatography or, styrene, chlorostyrene, bromostyrene, dibromostyrene, divinylbenzene, vinyl compounds such as diethylene glycol bis allyl carbonate, diallyl phthalate, (meth) allyl compounds such as diallyl biphenylene rate and the like.

  Preferred specific examples are shown below. The following various resin components may be used alone or in combination of two or more. Commercially available products for the prism lens or Fresnel lens resin can be obtained. For example, a UV curable resin (Desolite; Z9590, Z9502) manufactured by JSR Corporation may be used.

(A) Aliphatic mono (meth) acrylate methyl (meth) acrylate, butyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate

(B) alicyclic mono (meth) acrylate cyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, isobornyl (meth) acrylate, bornyl (meth) acrylate

(C) Aromatic mono (meth) acrylate Phenyl (meth) acrylate, benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxy-2-methylethyl (meth) acrylate, 3-phenoxy-2-hydroxypropyl (meth) ) Acrylate, 2-phenylphenyl (meth) acrylate, 2-phenylphenoxyethyl (meth) acrylate, 4-phenylphenoxyethyl (meth) acrylate, 2-phenylphenyl-2-methyloxyethyl (meth) acrylate, 2-naphthyl (Meth) acrylate, 2-bromophenyl (meth) acrylate, 4-bromophenyl (meth) acrylate, 2,4-dibromophenyl (meth) acrylate, 2,4,6-tribromophenyl (meth) acrylate, Enylthioethyl (meth) acrylate, phenylthioethoxyethyl (meth) acrylate

(D) Aromatic skeleton ester di (meth) acrylate bis (4- (meth) acryloxyethoxyphenyl) methane, bis (4- (meth) acryloxydiethoxyphenyl) methane, 2,2-bis (4- ( (Meth) acryloxyethoxyphenyl) propane, 2,2-bis (4- (meth) acryloxydiethoxyphenyl) propane, 2,2-bis (4- (meth) acryloxypentaethoxyphenyl) propane, 2,2 -Bis (4- (meth) acryloxypropoxyphenyl) propane, 2,2-bis (4- (meth) acryloxydipropoxyphenyl) propane, 2,2-bis (4- (meth) acryloxyethoxy-3) , 5-Dibromophenyl) propane, 2,2-bis (4- (meth) acryloxydiethoxy-3,5-dibromophenyl) Propane, 2,2-bis (4- (meth) acryloxypentaethoxy-3,5-dibromophenyl) propane, bis (4- (meth) acryloxyethoxyphenyl) sulfone, bis (4- (meth) acryloxy Diethoxyphenyl) sulfone, bis (4- (meth) acryloylthiophenyl) sulfide, bis (4- (meth) acryloxyethylthiophenyl) sulfide, etc.

(E) Alicyclic skeleton ester di (meth) acrylate bis (4- (meth) acryloxycyclohexyl) methane, bis (4- (meth) acryloxyethoxycyclohexyl) methane, bis (4- (meth) acryloxydi Ethoxycyclohexyl) methane, bis (4- (meth) acryloxycyclohexyl) propane, bis (4- (meth) acryloxyethoxycyclohexyl) propane, bis (4- (meth) acryloxydiethoxycyclohexyl) propane, dicyclopentane Di (meth) acrylate

(F) Aliphatic skeleton ester di (meth) acrylate ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, polyethylene glycol (n = 4 to 15) di (meth) acrylate , Propylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, polypropylene glycol (n = 4 to 15) di (meth) acrylate, 1,4-butanediol di (meth) acrylate, polybutylene glycol (n = 2-15) Di (meth) acrylate, neopentyl glycol di (meth) acrylate, di (meth) acrylate of hydroxyhyvalic acid neopentyl glycol ester, 1,6-hexanediol di (meth) acrylate Relate, 1,9-nonanediol di (meth) acrylate

(G) Multifunctional (meth) acrylate Trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol penta (meth) Acrylate

(H) Urethane poly (meth) acrylate tris (isocyanatohexyl) isocyanurate, isophorone diisocyanate, bis (4,4'-isocyanatocyclohexyl) methane, 1,3-bis (isocyanatomethyl) cyclohexane, metaxylylene diisocyanate , 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate and other polyisocyanate compounds and 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4 -Reaction products with (meth) acrylates containing hydroxyl groups, such as hydroxybutyl (meth) acrylate

(I) Epoxy poly (meth) acrylate 2,2-bis (4-glycidyloxycyclohexyl) propane, 2,2-bis (4-glycidyloxyphenyl) propane, bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol Reaction product of epoxy compound such as S diglycidyl ether, tetrabromobisphenol A diglycidyl ether, tetrabromobisphenol S diglycidyl ether and (meth) acrylic acid

(J) Polyester poly (meth) acrylate At least one of maleic acid, fumaric acid, phthalic acid, or succinic acid and at least one of ethylene glycol, propylene glycol, butylene glycol, trimethylolpropane, or pentaerythritol, and methacrylic acid Or reaction with acrylic acid

  As the active energy ray-sensitive catalyst, a catalyst that generates a radical source mainly in response to an active energy ray having a wavelength of 200 to 400 nm is more preferable. Specific examples include benzoin, benzoin monomethyl ether, benzoin isopropyl ether, acetoin, benzyl, benzophenone, p-methoxybenzophenone, diethoxyacetophenone, benzyldimethyl ketal, 2,2-diethoxyacetophenone, 1-hydroxycyclohexyl phenyl ketone, methylphenyl Carbonyl compounds such as glyoxylate, ethylphenylglyoxylate, 2-hydroxy-2-methyl-1-phenylpropan-1-one, sulfur compounds such as tetramethylthiuram monosulfide, tetramethylthiuram disulfide, 2, 4, Acylphosphine oxides such as 6-trimethylbenzoyldiphenylphosphine oxide are listed. These are used in one or a mixture of two or more. Among these, benzophenone, benzoin isopropyl ether, methylphenylglyoxylate, 1-hydroxycyclohexyl phenyl ketone, benzyldimethyl ketal, and 2,4,6-trimethylbenzoyldiphenylphosphine oxide are more preferable.

  Content of an active energy ray sensitive catalyst is 0.005-5 mass parts with respect to 100 mass parts of total amounts of a resin component, More preferably, it is 0.02-2 mass parts.

  In the lens layer, various additives such as an antioxidant, a heat stabilizer, a weather stabilizer, an ultraviolet absorber, an anti-yellowing agent, and an organic easiness can be used as long as the function as a lens is not impaired. Lubricants, pigments, dyes, bluing agents, organic or inorganic fine particles, fillers, antistatic agents, surfactants, leveling agents, nucleating agents, diffusing agents, and the like may be blended.

  The method of laminating the actinic radiation curable resin as a component of the lens layer on the surface of the adhesive modified layer of the adhesive modified substrate film is selected from various methods according to the required properties and applications. . For example, a method of applying the resin with a bar cut into a prism shape, or pouring the resin into a mold having a lens layer shape such as a prism shape, and the surface of the adhesion modified layer of the adhesive modified substrate film The method of superimposing is used.

  The actinic rays mean electromagnetic waves that polymerize acrylic vinyl groups such as ultraviolet rays, electron beams, radiation (α rays, β rays, γ rays, etc.). In practice, ultraviolet light is convenient. As the ultraviolet ray source, for example, an ultraviolet fluorescent lamp, a low pressure mercury lamp, a high pressure mercury lamp, an ultra high pressure mercury lamp, a xenon lamp, or a carbon arc lamp is used. The electron beam method is advantageous in that the apparatus is expensive and requires operation under an inert gas, but it does not need to contain a photopolymerization initiator or a photosensitizer.

  The thickness of the lens layer is arbitrarily selected depending on the purpose of the lens film and the shape of the lens unit. In general, the thickness of the lens layer is preferably from 0.1 to 5 mm, more preferably from 0.2 to 3 mm. When the thickness of the lens layer is less than 0.1 mm, there is a tendency that the effect as the lens layer cannot be obtained. On the other hand, when the thickness of the lens layer is thicker than 5 mm, the brightness tends to be insufficient.

  The pitch of the lens unit is also arbitrarily selected depending on the purpose of the lens film and the shape of the lens unit. In general, the distance between the centers of the lens layers is preferably 0.03 to 0.5 mm, more preferably 0.05 to 0.3 mm.

  In particular, a prismatic lens film in which prismatic lens layers are laminated is preferable in terms of luminance and ease of formation. The apex angle of the prism is preferably 80 to 150 degrees, more preferably 85 to 130 degrees.

(Light diffusion film)
In the present invention, the light diffusing film is an ionizing radiation curable hard coat layer containing inorganic fine particles on one side of an adhesive modified base film having an adhesive modified layer mainly composed of copolymer polyester and polyurethane. And a light diffusion layer on the opposite surface. The light diffusion film is sometimes called a light diffusion sheet, but in the present invention, the sheet is also included in the film.

  A light-diffusion layer is comprised from the composition containing binder resin and a light-diffusion agent. As the resin, an optically transparent resin is preferable. For example, acrylic resin, polyester resin, polyvinyl chloride, polyurethane, and silicone resin can be used. The resin is commercially available, for example, from Mitsubishi Rayon Co., Ltd. under the trade name “Dianar Series”.

  Further, as the particles used as the light diffusing agent, transparent particles are suitable. For example, silicone resin particles, acrylic resin particles, nylon resin particles, urethane resin particles, styrene resin particles, polyethylene resin particles, silica particles, polyester A resin particle is mentioned. These particles may be used alone or in combination of two or more. Further, the surface or the whole of the fine particles may be crosslinked. The mixing ratio of the particles to the resin is preferably 5 to 150 parts by mass with respect to 100 parts by mass of the resin from the viewpoint of obtaining sufficient light diffusibility while ensuring light transmittance.

  Moreover, the average particle diameter of said particle | grain is 1-70 micrometers normally, Preferably it is 5-50 micrometers. That is, when the average particle diameter of the particles is out of the above range, the balance between the light transmittance and the light diffusibility is lost, and the front luminance may not be increased. In addition, when spherical particles are used as the particles, each spherical particle acts as one type of lens and can have a more effective light diffusion effect. In particular, spherical particles are effective. The spherical particles are commercially available from Nippon Shokubai Co., Ltd. under the trade name Eposta, for example.

The typical manufacturing method of a light-diffusion film is shown below.
A coating solution in which a binder resin, solvent, and particles are mixed and dispersed at a specific ratio is applied to the surface of the adhesive modified layer of the adhesive modified base film (the surface opposite to the surface on which the hard coat layer is laminated). It is applied by a known application method. Next, the coating layer is dried and cured by a drying method such as natural drying or hot-air heating drying to form a light diffusion layer on the surface of the adhesive base film.

A suitable method for preparing the coating solution is as follows.
First, the binder resin is dissolved in a solvent at a specific ratio. In this solution, particles and, if necessary, other subcomponents are dispersed at a specific ratio to prepare a mixed dispersion. At this time, the viscosity of the mixed dispersion is adjusted to be in the range of 1 to 500 poise. The viscosity of the liquid can be measured using a Brookfield viscometer (B type viscometer).

  Subsequently, said coating liquid is apply | coated to the surface of the adhesive property modification layer of an adhesive property modification base film, and it is made to dry. The coating method for the coating solution is selected depending on the viscosity of the solution and the desired thickness of the coating layer. For example, examples of the coating method include a comma direct method, a roll coating method, a dipping method, a knife coating method, a curtain flow method, a spray coating method, a spin coating method, and a laminating method.

  In addition, as for the thickness of an adhesive property modification base film, 50-200 micrometers is preferable from the point of a use or workability | operativity. The thickness of the light diffusion layer is preferably 2 to 30 μm. Examples of the solvent include toluene, methyl ethyl ketone, xylene, cyclohexane, and ethyl acetate.

  In addition, although the mixing ratio of the solvent with respect to binder resin is suitably set by the coating method, workability | operativity, the kind of solvent, etc., 50-500 mass parts of solvents are preferable with respect to 100 mass parts of binder resins.

  Moreover, the mixing ratio of the solvent with respect to the particles is appropriately set in the range of 20 to 500 parts by mass of the solvent with respect to 100 parts by mass of the particles, depending on the coating method, workability, type of solvent, and the like. More preferably, it is 50-300 mass parts of solvent with respect to 100 mass parts of particle | grains. That is, when the mixing ratio of the solvent with respect to the particles is within the above range, the amount of the solvent with respect to the particles is an appropriate amount for softening the resin.

  In addition, as a secondary component of the light diffusion layer, for example, an isocyanate compound, an epoxy resin, a methylolated melamine resin, a methylolated urea resin, a metal salt, a metal hydroxide or other crosslinking agent, a guanidine derivative, a phosphate-containing anion activity Agent, sulfonic acid, quaternary ammonium salt, pyridinium salt, imidazoline derivative, morpholine derivative, polyoxyethylene-alkylphenol, alkylamide ether, sorbitan fatty acid ester and other antistatic agents, silane coupling agent Can be made.

  Next, although the hard coat film of this invention and an optical functional film using the same are demonstrated using an Example and a comparative example, this invention is naturally not limited to these Examples. Moreover, the physical properties and characteristics of the adhesion-modified base film, hard coat film, and optical functional film described in the examples were evaluated using the following methods.

(1) Phase separation structure of adhesive modified layer (1-1) Surface of adhesive modified layer of adhesive modified substrate film (1-1-1) Observation of phase image Surface of adhesive modified layer The phase-separated structure of the adhesive modified layer was evaluated in a phase measurement mode (phase mode) using a scanning probe microscope (SII Nanotechnology, SPI3800N system / SPA300). In the phase image, the larger the phase lag, the brighter the color image, and the smaller the phase lag, the darker the image. A small phase lag means that it is harder or has a relatively smaller adsorption force than the other phases. In the adhesion modified layer of the adhesion modified substrate film used in the present invention, the dark color phase is a polyester phase and the light color phase is a polyurethane phase.

  The measurement principle of the phase measurement mode in the scanning probe microscope is described in “1-2. Application (mode) on the website of STS Nanotechnology, Inc. (http://www.siint.com/technology/probe_applications.html). In the PDF file of “1. Phase measurement by SPM” in the Phase column.

  The cantilever used for the measurement was mainly DF3 (spring constant: about 1.6 N / m), and a new one was always used in order to prevent a decrease in sensitivity and resolution due to probe contamination. The scanner used was FS-20A. The phase image was observed with a resolution of 512 × 512 pixels or more, and the observation field of view was 5 μm × 5 μm. Measurement parameters such as the amplitude attenuation rate of the cantilever, the scanning speed, and the scanning frequency at the time of measurement were set to the conditions in which line scanning was performed and the sensitivity was highest and the resolution was observable.

(1-1-2) Measurement of area ratio of polyester phase (a) Image analysis The obtained phase mode image (bitmap format, 512 × 512 pixels) is read into image processing software (manufactured by Adobe, Photoshop ver 7.0). The image was displayed on the display so that the size of the image was 205 mm × 205 mm (see FIG. 1). Next, a black line was drawn at the boundary between the light hue and the dark hue with the pencil tool (master diameter: 3 px) of the same software to clarify the boundary between the two phases (see FIG. 2). Furthermore, using the paint tool of the same software, the dark hue was painted black and the light hue was painted white, and binarized (see FIG. 3). At this time, a dark color portion having a size on the screen and having a diameter of 2 mm or less in the light hue was determined to be particles unevenly distributed in the light hue, and was painted white. For example, when silica particles are used, it is confirmed that they are unevenly distributed in a light hue.

  This binarized image is displayed on the same software using a histogram with luminance (black, white) as the horizontal axis and frequency as the vertical axis, and the area ratio of the black part (polyester phase) is obtained to improve the adhesion. It was set as the area ratio of the polyester phase in the surface of the adhesive property modification layer in a base film.

(B) Paper weight method The area ratio of the polyester phase on the surface of the adhesive modified layer can be measured using a paper weight method in addition to the image analysis method. The measurement procedure is as follows.
The obtained phase mode image was stored as a digital image in bitmap format. Next, this image was printed out on A4 quality paper using a printer (Xerox, DocuPrint C830). For the output image (200 mm × 200 mm), the boundary between the light hue and the dark hue in the image was clarified with a 4B pencil in a bright room under 500 lux illumination by visual confirmation. At this time, it has been confirmed that the dark color portion having a diameter of 0.1 μm or less present in the light hue is a particle contained in the adhesive modified layer unevenly distributed in the light hue. Therefore, a line was not drawn between the light hue and the dark color portion inside the light hue, and the dark color portion was included in the light hue. Then, it divided | segmented by cutting on the boundary line which clarified the light hue and the dark hue with the cutter knife. Next, the mass of the light hue (polyurethane phase) and dark hue (polyester phase) paper is measured, and the ratio of the mass of the dark hue (polyester phase) to the total mass of the light hue and dark hue paper is determined in units of%. This was defined as the area ratio of the polyester phase on the surface of the adhesive modification layer.

(C) Fluctuation width of area ratio of polyester phase (difference between maximum value and minimum value)
(C-1) Longitudinal direction of film roll A roll composed of an adhesive modified base film having a length of 1000 m or more and a width of 50 mm or more was wound. About the longitudinal direction (MD) of this film, the area ratio of the polyester phase (it shows a dark hue in a phase image) in the surface of the said adhesive improvement layer was measured in the following location. Subsequently, the area ratio of the polyester phase in the surface of the adhesive property modification layer was calculated | required in each location. Furthermore, the difference between the maximum value and the minimum value was obtained from these area ratios.
The measurement of the area ratio of the polyester phase on the surface of the adhesive property modification layer is such that when one end of the steady region where the film physical properties are stable is the first end and the other end is the second end, The first measurement is performed within 2 m or less on the inner side, the final measurement is performed within 2 m or less on the inner side of the second end portion, and the measurement is performed every 100 m from the first measurement point.

(C-2) Width direction of film roll An adhesive modified substrate film roll having a length of 1000 m or more and a width of 50 mm or more was unwound, and the film was divided into four equal parts in the width direction with respect to the width direction (TD) of the film. . Subsequently, in each center part, the area ratio of the polyester phase (it shows a dark hue in a phase image) of the surface of the adhesive property modification layer was measured. Next, the difference between the maximum value and the minimum value of the area ratio of the polyester phase on the surface of the adhesive property modification layer in the width direction was determined. You may perform this measurement with the jumbo roll before slitting the width direction of a film to a small width size.

(1-2) Diagonal cutting surface of the adhesive modified layer in the hard coat film In the hard coat film of the present invention, the adhesive modified layer B is an intermediate layer between the thermoplastic resin film A and the hard coat layer C. is there. Therefore, it is difficult to directly observe the phase separation structure of the resin at the interface between the adhesive modified layer B and the hard coat layer C (the surface of the adhesive modified layer in the adhesive modified base film). is there. Therefore, the present inventors have found that the hard coat film is cut in the thickness direction, and the phase separation structure of the resin in the thickness direction of the adhesive property modification layer can be measured from the cut surface. In addition, since the thickness of the adhesive modified layer is generally thin, it is difficult to observe the phase separation structure of the resin from the cut surface of the adhesive modified layer. Therefore, the hard coat film was cut obliquely and at a shallow angle with respect to the thickness direction. As a result, the observation area in the thickness direction of the adhesive modification layer could be expanded. With this technique, it was possible to observe the phase separation structure of the resin constituting the adhesive modified layer in the vicinity of the interface between the adhesive modified layer B and the hard coat layer C.

  Below, the preparation method of the sample for evaluation and the evaluation method of the area ratio of the polyurethane phase in the cutting surface of the adhesive property modification layer in the vicinity of the interface with the hard coat layer C will be described in detail.

(1-2-1) Preparation of Cutting Sample The hard coat film of the present invention is A / B / C, where A is the thermoplastic resin film, B is the adhesive modification layer, and C is the hard coat layer. Or it is a laminated body containing the layer structure of B / A / B / C. The optical functional film using the hard coat film is a laminate including a layer configuration of D (including C) / B / A / B / C, where D is the other optical functional layer.

In the hard coat film or the optical functional film, the surface of the thermoplastic resin film A or the optical functional layer D is cut from the oblique direction using the cutting device 1 (SAICAS DN20-S type) under the following conditions. When the blade of the knife reaches a predetermined depth, a “cut limit” button is pressed to perform cutting at a certain depth. Moreover, when the thermoplastic resin film to cut is thick, it is preferable to perform cutting several times in the same place.
(A) Cutting means: diamond knife (rake angle: 40 degrees)
(B) Horizontal blade movement speed: 3000 nm / s
(C) Vertical blade movement speed: 200 nm / s

  The above-mentioned “predetermined depth” means a depth at which most of the thermoplastic resin film is cut and does not reach the adhesion modified layer. Further, “cutting restriction” means that the moving speed of the blade in the vertical direction is set to zero and cutting is performed only in the horizontal direction.

Subsequently, the same part was cut with high accuracy from an oblique direction under the conditions shown below using a cutting device 2 (SAICAS NN-04 type) to prepare a cutting sample.
(D) Cutting means: Diamond knife (rake angle: 40 degrees)
(E) Horizontal blade movement speed: 500 nm / s
(F) Vertical blade movement speed: 20 nm / s

  In addition, said cutting conditions are typical conditions for cutting the hard coat film obtained by the Example and comparative example as described in this invention. Depending on the sample, a three-dimensional cutting method using a three-dimensional cutting jig may be effective. The width of the diamond knife blade is usually 1 mm, but 0.3 mm may be effective. In the examples and comparative examples described in the present invention, a diamond knife having a blade width of 1 mm was used.

Therefore, when the material type of each layer of the hard coat film is different from the materials used in the examples and comparative examples described in the present invention, it is preferable to perform a preliminary test and determine appropriate cutting conditions.

  Moreover, when cutting from the surface of the optical functional layer D (including the hard coat layer C), depending on the physical properties of the optical functional layer, it may be necessary to heat or cool during cutting. For heating or cooling, a low / high temperature gas spraying device (TTFC-L type, manufactured by Daipura Wintes Co., Ltd.) may be used. The temperature at the time of heating or cooling or the gas flow rate is appropriately adjusted according to the state of the cutting surface.

(1-2-2) Observation of phase image On the cutting surface of the obtained cutting sample, the phase separation structure of the resin of the adhesive modification layer B is measured using the scanning probe microscope (SPM). Observation is made with the phase image obtained in the mode (phase mode). The phase mode is a phase lag measurement mode that is usually performed simultaneously with morphological observation in the dynamic force mode (DFM mode; when using SII NanoTechnology SPM). In the phase image of the cut surface of the adhesive property modification layer B, the dark color phase is a polyester phase and the light color phase is a polyurethane phase.

  The cantilever used for the measurement was mainly DF3 (spring constant: about 1.6 N / m), and a new one was always used in order to prevent a decrease in sensitivity and resolution due to probe contamination. The scanner used was FS-100A. The observation field of the phase image was 3 μm × 3 μm. The measurement parameters such as the amplitude attenuation rate of the cantilever, the scanning speed, and the scanning frequency during the measurement were set to the conditions under which line scanning was performed and the sensitivity was highest and the resolution was observable.

(1-2-3) Measurement of Area Ratio of Polyurethane Phase The drawings attached to the application documents include drawings displayed in color images, but for convenience of electronic filing, color images are Saved in file format and displayed in grayscale. Also, black and white images are stored in a JPEG file format and displayed in gray scale to prevent image quality deterioration.

(A) Reading of phase image The obtained phase image is read in color using SPIP software (Image Metrology, version 4.2.5).

(B) Enhancement of contrast of phase separation structure (see FIG. 8)
Next, with this software, a color equalization process is performed, and the contrast is enhanced so that the phase separation structure can be easily visualized.

(C) Determination of the observation range of the phase separation structure (see FIG. 9)
The phase image that has been subjected to the color uniformity processing is copied and pasted on the screen of presentation software (Microsoft PowerPoint 2002). Next, a red line 20 is drawn at the interface (B / C) between the adhesion modified layer B and the hard coat layer C. At this time, if the interface is unclear, the contrast is adjusted.

Further, from the interface (B / C) toward the adhesive property modification layer B, a red line indicating the above interface is copied and pasted in parallel at a depth of 20 nm in the vertical direction (see FIG. 9). Line 21). In addition, when producing the cutting sample, the laminated body is cut from the diagonal direction. Therefore, in the cutting conditions shown above, the position at a depth of 20 nm from the interface toward the adhesive property modification layer B corresponds to the position of 500 nm from the interface in FIG.
In this way, the range surrounded by these two red lines, that is, the range from the interface (B / C) to the depth of 20 nm of the adhesive modified layer B is the cutting surface of the adhesive modified layer B. The range in which the phase separation structure of the resin is observed.

(D) Image Processing of Phase Separation Structure The image of FIG. 8 is saved in the JPEG file format and pasted on the screen of image processing software (manufactured by Adobe, Photoshop ver 6.0.1). (See FIG. 10).

  Next, the image of FIG. 10 is pasted on the screen of the presentation software (Microsoft PowerPoint 2002). Then, the two red lines (20, 21) shown in FIG. 9 are displayed on the image of FIG. 10 so as to overlap with the image of FIG. 9 (see FIG. 11).

  The image shown in FIG. 11 is displayed on the screen of image processing software (manufactured by Adobe, Photoshop ver 6.0.1). Further, a portion other than the adhesive property modification layer B is painted in red using a brush tool (see FIG. 12). Using the same software, white, black, and red ternary images were displayed as a histogram with luminance (black, white) on the horizontal axis and frequency on the vertical axis.

In the phase image of the adhesive property modification layer B shown in FIG. 12, the black part is the polyester phase and particles, and the white part is the polyurethane phase. The area ratio of the polyurethane phase (white portion) of the adhesive modified layer B in the cut surface in the range from the interface between the adhesive modified layer B and the hard coat layer C to a depth of 20 nm is calculated by the following formula. Note that the “measurement area” on the right side of the following expression means a range surrounded by the line 20 (interface B / C) and the line 21 in the phase image of FIG.
Area ratio (%) of polyurethane phase = (area of white portion / measured area) × 100

(2) Presence / absence of locations where the width of the polyester phase is minimum and exceeds 1 μm In the above-mentioned phase mode image, the width in the minor axis direction is the narrowest in the polyester phase whose main component is the copolymer polyester at 10 different measurement locations. The presence or absence of a part exceeding 1 μm was examined.

(3) Fractal dimension of phase-separated structure Phase mode image (bitmap format) obtained by the phase measurement mode (phase mode) using the above-described scanning probe microscope (manufactured by SII Nano Technology, SPI3800N system / SPA300) 512 × 512 pixels) was read by image processing software (manufactured by Adobe, Photoshop ver. 7.0), and displayed on the display so that the image size was 205 mm × 205 mm (see FIG. 1). Next, a black line was drawn at the boundary between the light hue and the dark hue with the pencil tool (master diameter: 3 px) of the same software to clarify the boundary between the two phases (see FIG. 2). At this time, a dark color portion having a size of 2 mm or less in the bright hue with a size on the screen was determined to be a particle unevenly distributed in the bright hue, and the operation for drawing the boundary line was not performed on this portion. For example, when silica particles are used, it is confirmed that they are unevenly distributed in a light hue.

  An image with a clear boundary line was saved as a bitmap format image, and a fractal dimension analysis was performed by the box counting method. The obtained fractal dimension value was used as an index indicating the complexity of the phase separation boundary line. Image analysis software (AT-Image ver. 3.2) was used for analysis by the box counting method. Specifically, the saved bitmap image was opened on image analysis software (AT-Image ver. 3.2), and binarization processing by luminance histogram was performed from image extraction on the menu (see FIG. 6). The threshold value for binarization was 8. For the binarized image, the fractal dimension was selected from the image measurement on the menu, and the fractal dimension was obtained. At this time, for the calculation of the fractal dimension by the method of least squares, the counting result of a box having a side length of 6 pixels to 63 pixels was used.

  Note that the fractal dimension analysis by the box counting method is a known method, and using other image analysis software or program for the dimension analysis has other same functions as long as the reproducibility of the analysis result is sufficiently obtained. Software may be used. Examples of other software include image analysis such as “Fractal Analysis System Version 3.33 made by National Institute of Agricultural Sciences, Livestock Pasture Research Institute”, “PopImaging Ver. 3.40 made by Digital Being Kids”, etc. Software.

(4) Average particle size of inorganic fine particles in hard coat phase C A sample of a hard coat film was embedded in a visible light curable resin (for example, an epoxy resin) and allowed to cure at room temperature. Subsequently, an ultrathin section was prepared using an ultramicrotome equipped with a diamond knife and stained with ruthenium tetroxide. A cross section of the hard coat layer C was observed using a transmission electron microscope (TEM 2010, manufactured by JEOL Ltd.), and a photograph was taken of the stained ultrathin section. The magnification of the photograph is appropriately set in the range of 10,000 to 100,000 times according to the observed particle size of the inorganic particles. In Example 1 of the present invention, the magnification was set to 80,000 times (acceleration voltage 200 kv). From this photograph, the average particle diameter based on the number of inorganic fine particles in the hard coat layer C was determined.

(5) Haze Based on JIS K7136, using a haze meter (Nippon Denshoku make, NDH2000), haze was measured about three different places of a film sample, and the average value was used.

(6) Blocking resistance Adhesive modified layers of two adhesive modified substrate films were overlapped. Next, a pressure of 1 kgf / cm ² was applied to these, and they were brought into close contact under an atmosphere of 50 ° C. and 60% RH for 24 hours. Then, it peeled in the interface of the adhesive property modification layer of two adhesion modified base film and the adhesive property modification layer which adhered, and the peeling state was determined on the following reference | standard.
○: The adhesive modified layer is not easily transferred and can be peeled lightly. Δ: A peeling sound is generated, and the adhesive modified layer is partially transferred to the other surface. ×: Two films are fixed and peeled. That cannot be peeled off or that can be peeled, but the base polyester film is cleaved

(7) Hardness index of the adhesive modified layer The surface of the adhesive modified layer of the adhesive modified base film was scratched using a surface property measuring instrument (manufactured by Shintoa Chemical Co., HEIDON 14). At this time, a genuine needle having a sapphire with a radius of 75 μm at the tip was used as a scratching needle. The traveling speed of the needle was 150 mm / min, and the load was 5 gf.

  The surface shape of the scratches attached to the adhesive modified layer was measured under the following conditions using a three-dimensional non-contact surface shape measuring device (Micromap 550, manufactured by Micromap), and profile mode data was displayed. A representative example is shown in FIG. From the obtained shape data of the scratch, the height difference between the adjacent convex and concave portions was measured at 30 locations, and the average value thereof was determined and used as the hardness index of the adhesiveness modified layer. At this time, protrusions having a height of 30 nm or more were judged to be protrusions caused by particles contained in the adhesive modified layer or the thermoplastic resin film and excluded from the measurement data. Further, protrusions having a height of 1 nm or less were similarly excluded from the measurement data because of the influence of noise.

(Measurement condition)
-Profile mode: Wave mode-Objective lens: 10x-Resolution: 160 x 160 pixels-Measurement length: 207.1 nm

(8) Adhesiveness with hard coat layer (8-1) Adhesiveness between adhesion modified layer B and hard coat layer C In a glass plate having a thickness of 5 mm with a double-sided tape attached, in Examples and Comparative Examples The surface opposite to the hard coat layer C of the obtained hard coat film or optical functional film was attached. Next, 100 grid-like cuts that penetrated through the hard coat layer C and the adhesive modification layer B and reached the thermoplastic resin film A were made using a cutter guide with a gap interval of 2 mm. Next, an adhesive tape (manufactured by Nichiban Co., Ltd., No. 405; 24 mm width) was attached to the cut-like cut surface. The air remaining on the interface at the time of pasting was pushed with an eraser to bring it into close contact, and then the adhesive tape was peeled off vigorously and vertically. Further, a new adhesive tape was applied in the same manner, and it was peeled off in a vertical direction. This adhesive tape peeling operation was repeated a total of 10 times, and the adhesion was visually determined from the following formula. In addition, what is partially peeled within one square is also included in the number of peeled.
Adhesiveness (%) = (1-number of cells peeled off / 100) × 100

(8-2) Evaluation with Adhesive Modified Base Film A hard coat layer that is composed of two types of photocurable acrylic resins of a solvent dilution type and a solventless type and that does not contain particles is formed to form a hard coat. The adhesion between the layer and the adhesion modified layer B was evaluated according to the method described above. A sample for evaluating the adhesion of the adhesion-modified base film to the hard coat layer was prepared according to the following method.

(A) Adhesion with a hard coat layer composed of a solvent-diluted photocurable acrylic resin A hard coat agent (Seika Beam EXF01 (B) manufactured by Dainichi Seika Co., Ltd. )) 50 parts by weight, 25 parts by weight of toluene and 25 parts by weight of methyl ethyl ketone were mixed, and a well-stirred coating agent was applied with a wire bar, dried at 70 ° C. for 1 minute to remove the solvent, and then 200 mJ / cm with a high-pressure mercury lamp. ^2. A hard coat film having a hard coat layer having a thickness of 3 μm was obtained under an irradiation distance of 15 cm and a running speed of 5 m / min.

(B) Adhesion with a hard coat layer composed of a solvent-free photocurable acrylic resin On a 5 mm thick glass plate kept clean, a hard coat agent (manufactured by Dainichi Seika, Seika Beam EXF01 (B )) Put about 5g, superimpose so that the surface of the adhesion modified layer of the film sample and the hard coat agent are in contact, and stretch the hard coat agent with a manually loaded rubber roller 10cm wide and 4cm in diameter from above the film sample Crimped as follows. Next, from the film surface side, the hard coat layer was cured by irradiating ultraviolet rays with a high-pressure mercury lamp under conditions of 500 mJ / cm ² , an irradiation distance of 15 cm, and a running speed of 5 m / min. Subsequently, the film sample which has a hard-coat layer was peeled off from the glass plate, and the hard-coat film was obtained.

(9) Pencil hardness In accordance with JIS-K5400, the surface of the hard coat layer C is measured by a pencil hardness test. In the pencil hardness test, the test was repeated 5 times. When no abnormal appearance such as scratches was found on the surface of the hard coat layer C in all tests, the hardness of the pencil used in the test was determined as the pencil hardness. And For example, when a test is performed five times using a 3H pencil and no appearance abnormality occurs in all the tests, the pencil hardness of the material is at least 3H. In this evaluation, 3H or more was rated as ◯, and 2H or less as x.

Example 1
(1) Preparation of coating solution The coating solution used in the present invention was prepared according to the following method.
Dimethyl terephthalate (95 parts by mass), dimethyl isophthalate (95 parts by mass), ethylene glycol (35 parts by mass), neopentyl glycol (145 parts by mass), zinc acetate (0.1 parts by mass) and antimony trioxide (0. 1 part by mass) was charged into a reaction vessel, and a transesterification reaction was performed at 180 ° C. over 3 hours. Next, 5-sodium sulfoisophthalic acid (6.0 parts by mass) was added and the esterification reaction was performed at 240 ° C. over 1 hour, and then at 250 ° C. under reduced pressure (10 to 0.2 mmHg) for 2 hours. The polycondensation reaction was carried out to obtain a copolyester having a number average molecular weight of 19,500 and a softening point of 60 ° C.

  7.5 parts by mass of an aqueous dispersion of 30% by mass of the obtained copolyester (A) and a 20% by mass aqueous solution of a self-crosslinking polyurethane (B) containing an isocyanate group blocked with sodium bisulfite (first) 11.1 parts by mass of Elastolone H-3, manufactured by Ichiko Pharmaceutical Co., Ltd., 0.3 parts by mass of a catalyst for elastolone (Daiichi Kogyo Seiyaku, Cat 64), 39.8 parts by mass of water and 37.4 parts of isopropyl alcohol. Each part by mass was mixed. Furthermore, colloidal silica (manufactured by Nissan Chemical Industries, Snowtex OL; average particle) as 0.6 parts by mass of 10% by mass aqueous solution of a fluorine-based nonionic surfactant (manufactured by Dainippon Ink and Chemicals, MegaFuck F142D) 2.3 mass parts of a 20 mass% aqueous dispersion having a diameter of 40 nm), and 3.5 mass% aqueous dispersion of dry process silica (Nippon Aerosil, Aerosil OX50; average particle diameter 200 nm, average primary particle diameter 40 nm) as particles B 0.5 parts by mass of the liquid was added. Next, the pH of the coating solution is adjusted to 6.2 with a 5% by weight aqueous sodium bicarbonate solution, and the solution is precisely filtered with a felt type polypropylene filter having a filtration particle size (initial filtration efficiency: 95%) of 10 μm to prepare coating solution A. did. In addition, the said surfactant used what was pre-processed by the following method.

  Isopropyl alcohol (IPA) was added to the above-mentioned surfactant, and heated and dissolved in a 30 ° C. hot bath to prepare a 15 mass% surfactant IPA solution. This solution was filtered with a quantitative filter paper (Advantech Toyo, No. 5C) to remove insolubles and dust in the solution. After filtering the said solution, this solution was put into the airtight glass container, and it left still for 24 hours in a 0 degreeC freezer. After 24 hours, the solution containing the precipitated solid was subjected to suction filtration using the quantitative filter paper. The solid on the filter paper was vacuum-dried to obtain a solid, diluted with water to a 10% by mass aqueous solution, and used as a pretreated surfactant.

  The surfactant obtained by the pretreatment was analyzed with a TLC-coated plastic sheet (manufactured by Merck, silica gel 60) using methanol as a developing solution. As a result of coloring the sample spot with iodine vapor, it was confirmed that a spot corresponding to polyethylene glycol was not detected.

(2) Production of Adhesive Modified Base Film Polyethylene terephthalate (PET) resin pellets containing no particles and having an intrinsic viscosity of 0.62 dl / g as a raw material polymer are dried under reduced pressure at 135 ° C. for 6 hours (1 Torr) did. Next, the dried PET resin pellets were supplied to an extruder, melted and extruded into a sheet at about 285 ° C., and rapidly cooled and solidified on a metal roll maintained at a surface temperature of 20 ° C. to obtain a cast film. At this time, a stainless sintered filter medium having a filtration particle size (initial filtration efficiency: 95%) of 15 μm was used as a filter medium for removing foreign substances in the molten resin.

  The obtained cast film was heated to 95 ° 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 oriented PET film. Next, the coating solution A was microfiltered with a felt type polypropylene filter medium having a filtration particle size (initial filtration efficiency: 95%) of 10 μm, and applied to one side of a uniaxially oriented PET film by a reverse roll method. At this time, the application roll and the metalling roll of the coater were rolls having a surface with an ultra-hard chrome plating finish of 0.2 S or less and a roundness and cylindricity of 3/1000 mm.

Then, in a drying furnace divided into four zones arranged just above the coater, the first zone (135 ° C. for 1.0 second), the second zone (65 ° C. for 2.2 seconds), the third zone (40 ° C. 1.8 seconds), and the coated surface was dried in the fourth zone (1.8 seconds at 30 ° C.). The coating amount was 0.08 g / m ² as the final solid content. The transit time of the film from application to the film to the entrance of the drying oven was 0.8 seconds. Further, at this time, the wind speed of the drying air in the first zone is 30 m / sec, the supply air volume of the drying air is 130 m ³ / sec, the exhaust air volume is 170 m ³ / sec, and the air supply air volume from the second zone to the fourth zone Was set to 100 m ³ / sec, and the exhaust air volume was set to 150 m ³ / sec so that dry air did not flow to the coater side. The tension of the film was 7000 N / raw fabric, and both ends of the film were held with pinch rolls from the coating to the drying furnace inlet.

Furthermore, in the coating at this time, a coating apparatus in which the ratio of the capacity of the coating liquid tray, the capacity of the circulation tank, and the capacity of the preparation tank has the following relationship was used.
(A) Ratio of the volume of the coating liquid tray to the volume of the circulation tank = 1/50
(B) Capacity ratio of the circulation tank to the mixing tank = 1/40

  Subsequently, while holding the edge of the film with a clip, the film was guided to a hot air zone having a temperature of 120 ° C. and a wind speed of 15 m / sec, and stretched 4.3 times in the width direction. Next, while maintaining the width stretched in the width direction, the first heat setting zone (temperature: 200 ° C.), the second heat setting zone (temperature: 225 ° C.), and the third heat setting zone (temperature: 230 ° C.) , 4th heat setting zone (temperature: 230 ° C), 5th heat setting zone (temperature: 210 ° C), 6th heat setting zone (temperature: 170 ° C), 7th heat setting zone (temperature: 120 ° C) sequentially And let it pass. Note that a relaxation treatment of 3% in the width direction was performed in the sixth heat setting zone. Next, the uncoated portions at both ends of the film are trimmed, wound up by a winding device, further divided into four equal parts in the width direction, slitted, a width of 1000 mm, a film length of 1000 m, and a film thickness of 125 μm. The roll of the adhesion-modified polyester film was obtained. The hot air velocity in the heat fixing zone was 15 m / second, the passage time was 4.5 seconds in each zone, the nozzle interval for blowing hot air was 350 mm, and the number of nozzles per zone was 8.

  Table 4 shows the physical properties and characteristics of the adhesion-modified base film. In addition, the maximum and minimum values of the area ratio of the polyester phase on the surface of the adhesive modified layer in the longitudinal direction and the width direction of the roll of the obtained adhesive modified polyester film, the maximum value and the minimum value of hard Table 5 shows the maximum and minimum values of adhesion to the coating layer. In addition, about the blocking resistance, it was (circle) in all the measurement points.

(3) Manufacture of hard coat film Next, the hard coat layer C containing inorganic fine particles is laminated on one surface on the surface of the adhesive modified layer B of the above-mentioned adhesive modified base film by the following method. A coated film was obtained.

As an application liquid for forming a hard coat layer, an organic / inorganic hybrid hard coat agent (Desolite Z7410B; manufactured by JSR Corporation; solid content concentration) mainly composed of an ultraviolet curable acrylate monomer, zirconium oxide ultrafine particles, and methyl ethyl ketone : 50% by mass). This hard coat agent was applied to the surface of the adhesion modified layer B of the adhesion modified substrate film so as to have a dry thickness of 8 μm, and dried at 40 ° C. for 1 minute. Next, ultraviolet rays were irradiated with a high-pressure mercury lamp under the condition of 1000 mJ / cm ² to cure the resin and form a hard coat layer C.
The obtained hard coat layer contained 31 parts by mass of zirconium oxide ultrafine particles having an average particle diameter of 10 nm with respect to 100 parts by mass of the acrylate resin.

(Example 2)
In Example 1, a 10% by mass aqueous solution of a fluorine-based cationic surfactant (manufactured by Neos Co., Ltd., Aftergent 310) pretreated by the same method as in Example 1 was used as the surfactant used in the coating solution. An adhesive modified polyester film was obtained in the same manner as in Example 1 except that the coating liquid B was changed.
Next, a hard coat film in which a hard coat layer C containing inorganic fine particles is laminated on one surface is obtained in the same manner as in Example 1 on the surface of the adhesive modified layer B of the above-mentioned adhesive modified base film. It was.

(Example 3)
In the heat setting process of Example 1, the temperature of each heat setting zone is 190 ° C. in the first heat setting zone, 205 ° C. in the second heat setting zone, 220 ° C. in the third heat setting zone, and the fourth heat setting zone. The adhesive modified polyester film was obtained in the same manner as in Example 1 except that the temperature was 220 ° C.
Next, a hard coat film in which a hard coat layer C containing inorganic fine particles is laminated on one surface is obtained in the same manner as in Example 1 on the surface of the adhesive modified layer B of the above-mentioned adhesive modified base film. It was.

Example 4
In Example 1, except that the mass ratio of the copolyester and polyurethane in the coating solution was changed to the following coating solution C in which the mass ratio was changed to 60/40, the adhesive modified polyester was used in the same manner as in Example 1. A film was obtained.
(Preparation of coating liquid C)
9.0 parts by mass of a 30% by mass aqueous dispersion of the copolymerized polyester (A) used in Example 1 and 9.0 parts by mass of a 20% by mass aqueous solution of polyurethane (B) used in Example 1, for elastron A catalyst (Daiichi Kogyo Seiyaku Co., Ltd., Cat 64) 0.3 parts by mass, water 40.6 parts by mass, and isopropyl alcohol 37.3 parts by mass were mixed. Furthermore, the surfactant aqueous solution used in Example 1 was 0.6 parts by mass, and a 20% by mass aqueous dispersion of colloidal silica (manufactured by Nissan Chemical Industries, Snowtex OL; average particle size 40 nm) as particles A was 2.3. 0.5 parts by mass of a 3.5 mass% aqueous dispersion of dry process silica (manufactured by Nippon Aerosil Co., Ltd., Aerosil OX50; average particle diameter 200 nm, average primary particle diameter 40 nm) is added as mass parts and particles B, and 5 mass%. The pH was adjusted with an aqueous sodium bicarbonate solution, and a filter having a filtration performance of 5 μm and 1 μm was passed in this order to obtain coating solution C.

  Next, a hard coat film in which a hard coat layer C containing inorganic fine particles is laminated on one surface is obtained in the same manner as in Example 1 on the surface of the adhesive modified layer B of the above-mentioned adhesive modified base film. It was.

(Example 5)
In Example 1, except that the mass ratio of the copolyester and polyurethane in the coating solution was changed to the following coating solution D in which the mass ratio was changed to 40/60, the adhesive modified polyester was the same as in Example 1. A film was obtained.
(Preparation of coating solution D)
6.0 parts by mass of a 30% by mass aqueous dispersion of the copolyester (A) used in Example 1 and 13.5 parts by mass of a 20% by mass aqueous solution of polyurethane (B) used in Example 1 for elastron A catalyst (Daiichi Kogyo Seiyaku Co., Ltd., Cat 64) 0.3 parts by mass, water 38.9 parts by mass, and isopropyl alcohol 37.5 parts by mass were mixed. Furthermore, 0.6% by mass of a 10% by mass aqueous solution of the surfactant used in Example 1 and 20% by mass aqueous dispersion of colloidal silica (Nissan Chemical Industries, Snowtex OL; average particle size 40 nm) as particles A 0.5 parts by mass of a 3.5 mass% aqueous dispersion of 2.3 parts by mass of dry silica (Nippon Aerosil, Aerosil OX50; average particle size 200 nm, average primary particle size 40 nm) as particles B, The pH was adjusted to 6.2 with a 5% by weight aqueous sodium bicarbonate solution, and a filter having a filtration performance of 5 μm and 1 μm was passed in this order to obtain a coating solution D.

  Next, a hard coat film in which a hard coat layer C containing inorganic fine particles is laminated on one surface is obtained in the same manner as in Example 1 on the surface of the adhesive modified layer B of the above-mentioned adhesive modified base film. It was.

(Example 6)
In Example 1, an adhesion-modified polyester film was obtained in the same manner as in Example 1 except that the coating amount was 0.12 g / m ² as the final solid content.
Next, a hard coat film in which a hard coat layer C containing inorganic fine particles is laminated on one surface is obtained in the same manner as in Example 1 on the surface of the adhesive modified layer B of the above-mentioned adhesive modified base film. It was.

(Example 7)
In Example 1, the adhesive modified polyester film was prepared in the same manner as in Example 1 except that the following coating liquid E was used, in which the amount of the surfactant in the coating liquid was changed to 0.03% by mass. Got.
(Preparation of coating solution E)
In the preparation of the coating liquid of Example 1, 0.3 part by mass of a 10% by mass aqueous solution of a fluorine-based nonionic surfactant (manufactured by Dainippon Ink and Chemicals, MegaFuck F142D), 38.2 parts by mass of water, and Isopropyl alcohol was changed to 39.3 parts by mass.

  Next, a hard coat film in which a hard coat layer C containing inorganic fine particles is laminated on one surface is obtained in the same manner as in Example 1 on the surface of the adhesive modified layer B of the above-mentioned adhesive modified base film. It was.

(Example 8)
In Example 1, the modified adhesive polyester was used in the same manner as in Example 1 except that the amount of the surfactant in the coating solution was changed to 0.10% by mass and the following coating solution F was used. A film was obtained.
(Preparation of coating solution F)
In the preparation of the coating liquid of Example 1, 1.0 part by mass of a 10% by mass aqueous solution of a fluorine-based nonionic surfactant (manufactured by Dainippon Ink and Chemicals, MegaFuck F142D), 37.5 parts by mass of water, and Isopropyl alcohol was changed to 39.3 parts by mass.

  Next, a hard coat film in which a hard coat layer C containing inorganic fine particles is laminated on one surface is obtained in the same manner as in Example 1 on the surface of the adhesive modified layer B of the above-mentioned adhesive modified base film. It was.

Example 9
In Example 1, the film transit time from coating to the drying furnace inlet was 0.7 seconds, the drying time was 0.8 seconds, and the passage time of each zone in the heat setting treatment step was 3.5 seconds. An adhesive modified polyester film was obtained in the same manner as in Example 1 except that was changed to 100 μm.
Next, a hard coat film in which a hard coat layer C containing inorganic fine particles is laminated on one surface is obtained in the same manner as in Example 1 on the surface of the adhesive modified layer B of the above-mentioned adhesive modified base film. It was.

(Example 10)
In Example 1, the passage time of the film from the coating to the entrance of the drying furnace was 1.0 second, the drying time was 1.9 seconds, the passage time of each zone in the heat setting treatment step was 6.6 seconds, and the film thickness An adhesive modified polyester film was obtained in the same manner as in Example 1 except that was changed to 188 μm.
Next, a hard coat film in which a hard coat layer C containing inorganic fine particles is laminated on one surface is obtained in the same manner as in Example 1 on the surface of the adhesive modified layer B of the above-mentioned adhesive modified base film. It was.

(Example 11)
In Example 1, the adhesive modified polyester film was prepared in the same manner as in Example 1 except that the pH of the coating solution was changed to coating solution G adjusted to 7.9 using a 5% by mass aqueous sodium carbonate solution. Got.
Next, a hard coat film in which a hard coat layer C containing inorganic fine particles is laminated on one surface is obtained in the same manner as in Example 1 on the surface of the adhesive modified layer B of the above-mentioned adhesive modified base film. It was.

(Example 12)
In Example 1, an adhesive modified polyester film was obtained in the same manner as in Example 1 except that the adhesive modified layer B was applied to both sides of the uniaxially oriented polyester film. In addition, the passage time of the film from the application to the film to the entrance of the drying furnace was 0.8 second on one side and 1.0 second on the opposite side.

  A hard coat film in which the hard coat layer C was laminated on both sides of the above-mentioned adhesive modified base film via the adhesive modified layer B was obtained. In addition, the formation method of the hard-coat layer C is as follows.

On one surface of the adhesion modified layer B of the above-mentioned adhesion modified substrate film, the hard coat agent containing inorganic particles used in Example 1 is applied so that the film thickness after curing becomes 3 μm. And dried at 40 ° C. for 60 seconds. Furthermore, ultraviolet rays of 300 mJ / cm ² were irradiated to cure the resin, and the hard coat layer C was formed on one side.
Next, the same hard coat agent as described above was applied to the surface of the adhesive modified layer B on the opposite side with a Mayer bar so that the film thickness after curing was 3 μm, and dried at 40 ° C. for 60 seconds. I let you. Furthermore, the resin was cured by irradiating with 500 mJ / cm ² of ultraviolet rays to form a hard coat layer C on the other surface.

(Example 13)
In Example 1, an adhesion-modified polyester film was obtained in the same manner as in Example 1 except that the coating liquid H that was not subjected to the surfactant pretreatment was used.
Although the phase separation structure of the polyester phase and the polyurethane phase by the scanning probe microscope (SPM) on the surface of the adhesive modified layer of the obtained adhesive modified polyester film can be discriminated, it was somewhat unclear.

Next, a hard coat film in which a hard coat layer C containing inorganic fine particles is laminated on one surface is obtained in the same manner as in Example 1 on the surface of the adhesive modified layer B of the above-mentioned adhesive modified base film. It was.
The phase separation structure of the polyester phase and the polyurethane phase in the adhesion modified layer B on the cut surface of the obtained hard coat film was also somewhat unclear, as described above.

(Example 14)
In Example 1, the adhesive-modified polyester was prepared in the same manner as in Example 1 except that the following coating liquid I was used, in which the mass ratio of the dispersion medium (water / IPA) in the coating liquid was changed to 50/50. A film was obtained.
(Preparation of coating liquid I)
In preparation of the coating liquid of Example 1, 7.5 parts by mass of a 30% by mass aqueous dispersion of the copolymerized polyester used in Example 1 and 11.3% by mass of a 20% by mass aqueous solution of polyurethane used in Example 1 were used. Part, 0.3 parts by mass of elastolone catalyst (Daiichi Kogyo Seiyaku, Cat64), 30.4 parts by mass of water, and 46.8 parts by mass of isopropyl alcohol were mixed. Furthermore, 0.6% by mass of a 10% by mass aqueous solution of the surfactant used in Example 1 and 20% by mass aqueous dispersion of colloidal silica (Nissan Chemical Industries, Snowtex OL; average particle size 40 nm) as particles A 0.5 parts by mass of a 3.5 mass% aqueous dispersion of 2.3 parts by mass of dry silica (Nippon Aerosil, Aerosil OX50; average particle size 200 nm, average primary particle size 40 nm) as particles B, The pH was adjusted to 6.2 with a 5% by mass aqueous sodium bicarbonate solution, and a filter with a filtration performance of 5 μm and 1 μm was passed in this order to obtain a coating solution I.

  Next, a hard coat film in which a hard coat layer C containing inorganic fine particles is laminated on one surface is obtained in the same manner as in Example 1 on the surface of the adhesive modified layer B of the above-mentioned adhesive modified base film. It was.

(Example 15)
In Example 1, an adhesion-modified polyester film having a thickness of 125 μm was obtained in the same manner as in Example 1 except that the coating liquid J was used and the pH of the coating liquid was changed to 4.6 with acetic acid. .
Next, a hard coat film in which a hard coat layer C containing inorganic fine particles is laminated on one surface is obtained in the same manner as in Example 1 on the surface of the adhesive modified layer B of the above-mentioned adhesive modified base film. It was.

(Example 16)
In Example 1, an adhesive modified polyester film was obtained in the same manner as in Example 1 except that the coating liquid K was used in which the polyurethane (B) was changed to the following polyurethane. Polyurethane was obtained by the following method.
(Preparation of polyurethane)
93 polyester diols (OHV: 111.8 eq / ton, AV: 1.1 eq / ton) having a composition of adipic acid // 1.6-hexanediol / neopentyl glycol (molar ratio: 4 // 3/2) 22 parts by mass of xylylene diisocyanate were mixed and reacted at 95-100 ° C. for 1 hour under a nitrogen stream to obtain a urethane prepolymer (NCO / OH ratio: 1.50, free isocyanate group: theoretical value 3.29). Mass%, measured value 3.16 mass%).

  The obtained urethane prepolymer was cooled to 60 ° C., added with 4.5 parts by mass of methyl ethyl ketoxime, reacted at 60 ° C. for 50 minutes, contained 1.3% by mass of free isocyanate, and partially blocked. A urethane prepolymer was obtained. Then, the said urethane prepolymer was cooled to 55 degreeC, the mixed solvent which consists of 9 mass parts of isopropyl alcohol and 140 mass parts of methanol was added, and it mixed uniformly. Next, 9.3 parts by mass of a 50% by mass aqueous sodium bisulfite solution and 5.4 parts by mass of a 30% by mass aqueous solution of N-methyltaurine were added and vigorously stirred. Water solubility began to appear after about 30 minutes, and free sodium bisulfite became almost zero after 2 hours, and the reaction was completed. Water was added thereto to obtain a 20% by mass aqueous solution that was cloudy and viscous.

  Next, a hard coat film in which a hard coat layer C containing inorganic fine particles is laminated on one surface is obtained in the same manner as in Example 1 on the surface of the adhesive modified layer B of the above-mentioned adhesive modified base film. It was.

(Comparative Example 1)
(1) Preparation of coating liquid L 33.7 parts by mass of dimethyl terephthalate, 20.0 parts by mass of dimethyl isophthalate, 9.1 parts by mass of 5-Nasulfodimethylisophthalate, 40.0 parts by mass of ethylene glycol 10.0 parts by mass of diethylene glycol Part, 0.049 parts by mass of calcium acetate · monohydrate, and transesterification was performed at 200 to 230 ° C. until the theoretical amount of methanol was distilled off. Next, 0.09 part by mass of orthophosphoric acid was added and polymerized at 280 ° C. under reduced pressure to obtain a copolymerized polyester.

Polyether containing a sulfonate group obtained by sulfonating a polyether of ethylene oxide starting from allyl alcohol with sodium metabisulfite (SO ₃ content: 8.3% by mass, polyethylene oxide content: 83% by mass), 192 parts by mass, poly 1013 parts by mass of tetramethylene adipate (number average molecular weight: 2,250) and 248 parts by mass of polypropylene oxide polyether (number average molecular weight: 550) initiated with bisphenol A were mixed and dehydrated at 100 ° C. under vacuum.

  The mixture is brought to 70 ° C., to which is added a mixture of 178 parts by weight of isophorone diisocyanate and 244 parts of hexamethylene-1,6-diisocyanate, and then the resulting mixture is heated from 80 ° C. until the isocyanate content is 5.6% by weight. The mixture was stirred at 90 ° C. The prepolymer was cooled to 60 ° C., and 56 parts by mass of biuret polyisocyanate obtained from 3 mol of hexamethylene diisocyanate and 1 mol of water, and 175 parts by mass of bischemitin obtained from isophorodiamine and acetone were added successively to form an aqueous polyurethane dispersion. Obtained.

  The copolymer polyester and the polyurethane aqueous dispersion were blended so as to be 20 parts by mass and 80 parts by mass, respectively, and an aqueous dispersion having a solid content concentration of 10% by mass was prepared. Note that particles and a surfactant were not blended in the coating solution.

(2) Production of Adhesive Modified Substrate Film As a raw material polymer, polyethylene terephthalate resin pellets containing no particles and having an intrinsic viscosity of 0.66 dl / g were dried under reduced pressure (1 Torr) at 135 ° C. for 6 hours, It was supplied to an extruder, melted and extruded into a sheet at about 285 ° C., and rapidly cooled and solidified on a metal roll maintained at a surface temperature of 60 ° C. to obtain a cast film. At this time, as in the case of Example 1, a stainless sintered filter material having a filtration particle size (initial filtration efficiency: 95%) of 15 μm was used as a filter material for removing foreign matters from the molten resin.

Next, this cast film was heated to 95 ° 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 difference in peripheral speed to obtain a uniaxially oriented PET film. Next, the coating liquid L was microfiltered with a felt type polypropylene filter medium having a filtration particle size (initial filtration efficiency of 95%) of 10 μm, and applied to one side of a uniaxially oriented PET film by a reverse roll method. Then, the edge part of the film was hold | gripped with the clip, was guide | induced to the hot air zone heated at 110 degreeC, and was extended | stretched 3.5 times in the width direction after drying. At this time, the wind speed in the tenter was 15 m / second, and the drying time was 20 seconds. The time from application to the film to the tenter entrance was 10.0 seconds. The coating amount was 0.15 g / m ² as the final solid content.

Next, while maintaining the width of the film stretched in the width direction, the first heat setting zone (200 ° C.), the second heat setting zone (205 ° C.), the third heat setting zone, and the fourth heat setting zone (210 ° C), the fifth heat setting zone (215 ° C), the sixth heat setting zone (220 ° C), and the seventh heat setting zone (170 ° C). Further, after relaxation treatment of 3% in the width direction in the seventh heat setting zone, the uncoated portions at both ends of the film were trimmed to obtain an adhesive modified polyester film having a thickness of 125 μm. The hot air velocity in the heat fixing zone was 15 m / second, the passage time was 4.5 seconds in each zone, the nozzle interval for blowing hot air was 700 mm, and the number of nozzles per zone was four.
On the surface of the adhesive modified layer of the obtained adhesive modified polyester film, the phase separation structure of the copolyester and polyurethane was unclear.

(3) Production of Hard Coat Film Next, the hard coat layer C containing inorganic fine particles was applied to the surface of the adhesive modified layer B of the above-mentioned adhesive modified base film in the same manner as in Example 1. A hard coat film to be laminated on was obtained.

(Comparative Example 2)
(1) Preparation of coating liquid M 3.0 mass parts of 30 mass% aqueous dispersion of copolymerized polyester (A) used in Example 1 and 20 mass% aqueous solution of polyurethane (B) used in Example 1 18.0 parts by mass, elastolonic catalyst (Daiichi Kogyo Seiyaku Co., Ltd., Cat 64) 0.3 parts by mass, water 70.7 parts by mass, and isopropyl alcohol 4.7 parts by mass were mixed. Furthermore, as a surfactant, 0.6 part by mass of a 10% by mass aqueous solution of dodecylbenzenesulfonic acid, and as a particle A, a 20% by mass aqueous dispersion of colloidal silica (manufactured by Nissan Chemical Industries, Snowtex OL; average particle size 40 nm). 0.5 parts by mass of a 3.5 mass% aqueous dispersion of 2.3 parts by mass of dry silica (Nippon Aerosil, Aerosil OX50; average particle size 200 nm, average primary particle size 40 nm) as particles B, A coating solution M was obtained. The pH of the coating liquid M was 4.8 because pH was not adjusted.

(2) Production of Adhesive Modified Base Film A polyethylene terephthalate resin pellet having an intrinsic viscosity of 0.62 dl / g, which does not contain the particles used in Example 1, is dried under reduced pressure at 135 ° C. for 6 hours (1 Torr). ), And supplied to an extruder, melted and extruded into a sheet at about 285 ° C., and rapidly cooled and solidified on a metal roll maintained at a surface temperature of 20 ° C. to obtain a cast film. At this time, a stainless sintered filter medium having a filtration particle size (initial filtration efficiency: 95%) of 15 μm was used as a filter medium for removing foreign substances from the molten resin.

  The obtained cast film was heated to 95 ° 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 oriented PET film. Next, the coating liquid M was microfiltered with a felt type polypropylene filter medium having a filtration particle size (initial filtration efficiency: 95%) of 10 μm, and applied to one side of a uniaxially oriented PET film by a reverse roll method.

Subsequently, while holding the edge of the film with a clip, the film was guided to a hot air zone heated to 80 ° C., and the coated surface was dried and then stretched 4.0 times in the width direction. At this time, the wind speed in the tenter was 15 m / second, and the drying time was 20 seconds. The time from application to the tenter inlet was 10.0 seconds. The coating amount was set to 0.10 g / m ² as the final solid content. Further, the temperature in each heat setting treatment step is 200 ° C. in the first heat setting zone, 210 ° C. in the second heat setting zone, 220 ° C. in the third heat setting zone, 225 ° C. in the fourth heat setting zone, and the fifth heat. The film thickness is the same as in Comparative Example 1 except that the fixing zone is 230 ° C., the sixth heat fixing zone is 235 ° C., the seventh heat fixing zone is 240 ° C., and the relaxation treatment in the width direction is not performed. Of 125 μm was obtained.
A phase separation structure between the polyester phase and the polyurethane phase could not be observed on the surface of the adhesion modified layer of the obtained adhesion modified polyester film.

(3) Production of Hard Coat Film Next, the hard coat layer C containing inorganic fine particles was applied to the surface of the adhesive modified layer B of the above-mentioned adhesive modified base film in the same manner as in Example 1. A hard coat film to be laminated on was obtained.
The phase separation structure of the polyester phase and the polyurethane phase in the adhesion modified layer B on the cut surface of the obtained hard coat film could not be observed in the same manner as described above.

(Comparative Example 3)
(1) Preparation of coating liquid N 7.5 parts by mass of a 30% by mass aqueous dispersion of copolymerized polyester (A) used in Example 1 and a 20% by mass aqueous solution of polyurethane (B) used in Example 1 11.3 parts by mass, 0.3 parts by mass of an elastron catalyst (Daiichi Kogyo Seiyaku Co., Ltd., Cat 64), 40.5 parts by mass of water, and 39.5 parts by mass of isopropyl alcohol were mixed. Furthermore, 0.6 mass parts of a 10% by mass aqueous solution of an untreated fluorine-based nonionic surfactant (manufactured by Dainippon Ink and Chemicals, Megafuck F142D), aggregates as particles A without using particles B 0.03 parts by mass of a 3.5 mass% aqueous dispersion of silica (manufactured by Fuji Silysia Chemical Co., Ltd., Silicia 310; average particle size of 1.4 μm) was added to prepare a coating solution N. The pH of the coating liquid N was not adjusted. The pH of the coating liquid N was 4.6.

(2) Production of Adhesive Modified Base Film A polyethylene terephthalate resin pellet having an intrinsic viscosity of 0.62 dl / g that does not contain the particles used in Example 1 as a raw material polymer is supplied to an extruder and is about 285 ° C. And melt-extruded into a sheet and rapidly solidified on a metal roll maintained at a surface temperature of 20 ° C. to obtain a cast film. At this time, a stainless sintered filter medium having a filtration particle size (initial filtration efficiency: 95%) of 15 μm was used as a filter medium for removing foreign substances from the molten resin.

  The obtained cast film was heated to 95 ° 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 oriented PET film. Next, the coating liquid L was microfiltered with a felt type polypropylene filter medium having a filtration particle size (initial filtration efficiency: 95%) of 10 μm, and applied to one side of a uniaxially oriented PET film by a reverse roll method.

After the application, it was introduced into a drying furnace and dried at a temperature of 120 ° C. for 3.2 seconds. The coating amount was 0.08 g / m ² as the final solid content. The film transit time from coating to the drying furnace inlet was 3.2 seconds. Further, the wind speed in the first zone of the drying furnace is 15 m / second, and the wind speed in the second zone to the fourth zone is the same as in the first embodiment. Both zones were set to 70 m ³ / sec, and the exhaust air was naturally exhausted from before and after the drying furnace.

  Subsequently, the film was stretched in the same manner as in Example 1 except that the transverse stretching ratio was set to 4.0 times, and subjected to heat fixing and relaxation treatment in the width direction in the same manner as in Comparative Example 1, so that the film thickness was A 125 μm adhesive-modified polyester film was obtained. A phase separation structure between the polyester phase and the polyurethane phase could not be observed on the surface of the adhesion modified layer of the obtained adhesion modified polyester film.

(3) Production of Hard Coat Film Next, the hard coat layer C containing inorganic fine particles was applied to the surface of the adhesive modified layer B of the above-mentioned adhesive modified base film in the same manner as in Example 1. A hard coat film to be laminated on was obtained.
Similarly to the above, the phase separation structure of the polyester phase and the polyurethane phase in the adhesion modified layer B on the cut surface of the obtained hard coat film could not be observed.

(Comparative Example 4)
In Example 1, the adhesiveness with a film thickness of 125 μm was used in the same manner as in Example 1 except that the film transit time from application of coating solution A to the film to the entrance of the drying furnace was 3.2 seconds. A modified polyester film was obtained.
Next, a hard coat film in which a hard coat layer C containing inorganic fine particles is laminated on one surface is obtained in the same manner as in Example 1 on the surface of the adhesive modified layer B of the above-mentioned adhesive modified base film. It was.

(Comparative Example 5)
3.0 parts by mass of a 30% by mass aqueous dispersion of the copolyester (A) used in Example 1, 18.0 parts by mass of a 20% by mass aqueous solution of polyurethane (B) used in Example 1, for elastron A catalyst (Daiichi Kogyo Seiyaku Co., Ltd., Cat 64) 0.3 parts by mass, water 37.3 parts by mass, and isopropyl alcohol 37.8 parts by mass were mixed. Furthermore, 0.6% by mass of a 10% by mass aqueous solution of the surfactant used in Example 1 and 20% by mass aqueous dispersion of colloidal silica (Nissan Chemical Industries, Snowtex OL; average particle size 40 nm) as particles A 0.5 parts by mass of a 3.5 mass% aqueous dispersion of 2.3 parts by mass of dry silica (Nippon Aerosil, Aerosil OX50; average particle size 200 nm, average primary particle size 40 nm) as particles B, The pH was adjusted to 6.2 with a 5% by weight aqueous sodium bicarbonate solution to obtain a coating solution O. An adhesive modified polyester film having a film thickness of 125 μm was obtained in the same manner as in Example 1 except that the coating liquid O was used as the coating liquid.

  Next, a hard coat film in which a hard coat layer C containing inorganic fine particles is laminated on one surface is obtained in the same manner as in Example 1 on the surface of the adhesive modified layer B of the above-mentioned adhesive modified base film. It was.

(Comparative Example 6)
12.0 parts by mass of a 30% by mass aqueous dispersion of the copolyester (A) used in Example 1, 4.5 parts by mass of a 20% by mass aqueous solution of polyurethane (B) used in Example 1, for elastron The catalyst (Daiichi Kogyo Seiyaku Co., Ltd., Cat 64) 0.3 parts by mass, 42.3 parts by mass of water and 37.2 parts by mass of isopropyl alcohol were mixed, and 10 surfactants used in Example 1 were mixed. 0.6% by mass of a mass% aqueous solution, 2.3 parts by mass of a 20% by mass aqueous dispersion of colloidal silica (manufactured by Nissan Chemical Industries, Snowtex OL; average particle size 40 nm) as particles A, and dry process silica as particles B 0.5 parts by mass of a 3.5% by mass aqueous dispersion (manufactured by Nippon Aerosil Co., Ltd., Aerosil OX50; average particle size 200 nm, average primary particle size 40 nm) was added, and the pH was adjusted to 6.2 with a 5% by mass aqueous sodium bicarbonate solution. Adjustment , It was a coating liquid P. An adhesive modified polyester film having a film thickness of 125 μm was obtained in the same manner as in Example 1 except that the coating liquid P was used as the coating liquid.

  Next, a hard coat film in which a hard coat layer C containing inorganic fine particles is laminated on one surface is obtained in the same manner as in Example 1 on the surface of the adhesive modified layer B of the above-mentioned adhesive modified base film. It was.

(Comparative Example 7)
In Example 1, the temperature in each heat setting treatment step was 190 ° C. in the first heat setting zone, 195 ° C. in the second heat setting zone, and 200 ° C. in the third heat setting zone to the fifth heat setting zone. Obtained an adhesive modified polyester film having a film thickness of 125 μm in the same manner as in Example 1. A phase separation structure between the polyester phase and the polyurethane phase could not be observed on the surface of the adhesion modified layer of the obtained adhesion modified polyester film.

Next, a hard coat film in which a hard coat layer C containing inorganic fine particles is laminated on one surface is obtained in the same manner as in Example 1 on the surface of the adhesive modified layer B of the above-mentioned adhesive modified base film. It was.
Similarly to the above, the phase separation structure of the polyester phase and the polyurethane phase in the adhesion modified layer B on the cut surface of the obtained hard coat film could not be observed.

(Comparative Example 8)
In Example 1, an adhesive modified polyester film having a film thickness of 125 μm was obtained in the same manner as in Example 1 except that the wind speed in the drying furnace was changed to 15 m / sec.
Next, a hard coat film in which a hard coat layer C containing inorganic fine particles is laminated on one surface is obtained in the same manner as in Example 1 on the surface of the adhesive modified layer B of the above-mentioned adhesive modified base film. It was.

(Comparative Example 9)
In Example 1, an adhesive modified polyester film having a film thickness of 125 μm was obtained in the same manner as in Example 1 except that the final coating amount was 0.20 g / m ^2. It was.
Next, a hard coat film in which a hard coat layer C containing inorganic fine particles is laminated on one surface is obtained in the same manner as in Example 1 on the surface of the adhesive modified layer B of the above-mentioned adhesive modified base film. It was.

(Comparative Example 10)
In Example 1, the same procedure as in Example 1 was used except that the coating solution Q was adjusted to 9.0 with a 5% by weight aqueous sodium carbonate solution, and the adhesive modification with a film thickness of 125 μm was used. A quality polyester film was obtained.
Next, a hard coat film in which a hard coat layer C containing inorganic fine particles is laminated on one surface is obtained in the same manner as in Example 1 on the surface of the adhesive modified layer B of the above-mentioned adhesive modified base film. It was.

(Comparative Example 11)
In Example 1, an adhesion-modified polyester film having a film thickness of 125 μm was obtained in the same manner as in Example 1 except that the coating liquid R prepared without adding a surfactant to the coating liquid was used. It was.
Next, a hard coat film in which a hard coat layer C containing inorganic fine particles is laminated on one surface is obtained in the same manner as in Example 1 on the surface of the adhesive modified layer B of the above-mentioned adhesive modified base film. It was.

(Example 17)
7.5 parts by mass of a 30% by mass aqueous dispersion of the copolyester (A) used in Example 1 and 11.3 parts by mass of a 20% by mass aqueous solution of polyurethane (B) used in Example 1 for elastron A catalyst (Daiichi Kogyo Seiyaku Co., Ltd., Cat 64) 0.3 parts by mass, water 40.5 parts by mass and isopropyl alcohol 39.5 parts by mass were mixed. Furthermore, 0.6 part by mass of a 10% by mass aqueous solution of the surfactant used in Example 1 and particles A as aggregate silica (manufactured by Fuji Silysia Chemical, Silicia 310; average particle size of 1.4 μm) The coating solution S was obtained by adding 4.3 parts by mass of a 5% by mass aqueous dispersion, adjusting the pH to 6.2 with a 5% by mass aqueous sodium bicarbonate solution, and sequentially passing through a filter having a filtration performance of 5 μm and 1 μm. In addition, the particle | grains B were not mix | blended with the coating liquid. An adhesion-modified polyester film having a film thickness of 125 μm was obtained in the same manner as in Example 1 except that the coating solution S was used.

  Next, a hard coat film in which a hard coat layer C containing inorganic fine particles is laminated on one surface is obtained in the same manner as in Example 1 on the surface of the adhesive modified layer B of the above-mentioned adhesive modified base film. It was.

(Comparative Example 12)
In Example 1, the film thickness was the same as in Example 1 except that the coating liquid T prepared so that only the amount of the surfactant in the coating liquid was 0.60% by mass in terms of solid content was used. A 125 μm adhesive-modified polyester film was obtained.
Next, a hard coat film in which a hard coat layer C containing inorganic fine particles is laminated on one surface is obtained in the same manner as in Example 1 on the surface of the adhesive modified layer B of the above-mentioned adhesive modified base film. It was.

(Example 18)
In Example 1, the temperature in each heat setting treatment step is 200 ° C. in the first heat setting zone, 210 ° C. in the second heat setting zone, 215 ° C. in the third heat setting zone, 220 ° C. in the fourth heat setting zone, Example 1 except that 225 ° C. in the fifth heat setting zone, 230 ° C. in the sixth heat setting zone, 170 ° C. in the seventh heat setting zone, and 3% relaxation treatment in the width direction in the seventh heat setting zone In the same manner as above, an adhesive-modified polyester film having a film thickness of 125 μm was obtained by trimming the uncoated portions at both ends of the film.
Next, a hard coat film in which a hard coat layer C containing inorganic fine particles is laminated on one surface is obtained in the same manner as in Example 1 on the surface of the adhesive modified layer B of the above-mentioned adhesive modified base film. It was.

(Comparative Example 13)
In Example 1, 7.5 parts by mass of a 30% by mass aqueous dispersion of the copolyester (A) used in Example 1 and 11.3% of a 20% by mass aqueous solution of polyurethane (B) used in Example 1 were used. 0.3 parts by mass, elastron catalyst (Daiichi Kogyo Seiyaku, Cat 64), 51.0 parts by mass of water, and 26.2 parts by mass of isopropyl alcohol were mixed. Furthermore, 0.6% by mass of a 10% by mass aqueous solution of the surfactant used in Example 1 and 20% by mass aqueous dispersion of colloidal silica (Nissan Chemical Industries, Snowtex OL; average particle size 40 nm) as particles A 0.5 parts by mass of a 3.5 mass% aqueous dispersion of 2.3 parts by mass of dry silica (Nippon Aerosil, Aerosil OX50; average particle size 200 nm, average primary particle size 40 nm) as particles B, An adhesive modified polyester film was obtained in the same manner as in Example 1 except that the pH was adjusted to 6.2 with a 5% by weight aqueous sodium bicarbonate solution and the coating solution U was used.
Next, a hard coat film in which a hard coat layer C containing inorganic fine particles is laminated on one surface is obtained in the same manner as in Example 1 on the surface of the adhesive modified layer B of the above-mentioned adhesive modified base film. It was.

(Comparative Example 14)
In Example 1, a hard coat layer (Seika Beam EXF-01B, manufactured by Dainichi Seika Co., Ltd.) that does not contain inorganic fine particles and is composed of a solvent-diluted photocurable acrylate resin was used as the hard coat agent. Except for this, a hard coat film in which a hard coat layer containing no inorganic fine particles was laminated on one side was obtained in the same manner as in Example 1.
The obtained hard coat film was excellent in the adhesion between the hard coat layer and the adhesion modified layer, but the hardness decreased and the curl also increased.

(Example 19)
In the preparation of the coating liquid of Example 1, a fluorine-based nonionic surfactant (Dainippon Ink Chemical Co., Ltd.) instead of a 10% by mass aqueous solution of a fluorine-based nonionic surfactant (Dainippon Ink & Chemicals, MegaFuck F142D). An adhesive-modified polyester film was obtained in the same manner as in Example 1 except that the coating liquid V was used using a 5% by mass aqueous solution manufactured by Megafac F444). Next, a hard coat film in which a hard coat layer C containing inorganic fine particles is laminated on one surface is obtained in the same manner as in Example 1 on the surface of the adhesive modified layer B of the above-mentioned adhesive modified base film. It was.

(Example 20)
In Example 1, an adhesive modified polyester film was obtained in the same manner as in Example 1 except that the adhesive modified layer B was applied to both sides of the uniaxially oriented polyester film. In addition, the passage time of the film from the application to the film to the entrance of the drying furnace was 0.8 second on one side and 1.0 second on the opposite side.

  A prism lens film was obtained in which a hard coat layer C was laminated on one side and a prism lens sheet layer D was laminated on the other side of the above-mentioned adhesive modified base film via an adhesive modified layer B.

First, a method for forming the hard coat layer C will be described.
On one surface of the adhesion modified layer B of the above-mentioned adhesion modified substrate film, the hard coat agent containing inorganic particles used in Example 1 is applied so that the film thickness after curing becomes 3 μm. And dried at 40 ° C. for 60 seconds. Furthermore, 300 mJ / cm ² of ultraviolet rays were irradiated and cured to form a hard coat layer C on one side.

Next, a method for forming the prism lens layer D will be described.
After injecting an ultraviolet curable resin liquid (Desolite Z9590, manufactured by JSR Corporation) into a mold obtained by cutting a prism-shaped inverted mold having a pitch of 0.05 mm and an apex angle of 90 °, the hard coat layer C On the surface of the adhesion modified layer B opposite to the above, the above mold was overlaid. Next, from the hard coat layer C side, an ultraviolet lamp (output: 6.4 kw) was irradiated with 80 w / cm of ultraviolet rays to cure the resin, and then peeled to form a prism lens layer.

(Example 21)
In Example 1, an adhesive modified polyester film was obtained in the same manner as in Example 1 except that the adhesive modified layer was applied on both sides of the uniaxially oriented polyester film. In addition, the passage time of the film from the application to the film to the entrance of the drying furnace was 0.8 second on one side and 1.0 second on the opposite side.

  A light diffusing film in which a hard coat layer C was laminated on one side and a light diffusing layer D ′ on the other side was laminated on the above-mentioned adhesive modified base film via an adhesive modified layer B was obtained.

First, a method for forming the hard coat layer C will be described.
On one surface of the adhesion modified layer B of the above-mentioned adhesion modified substrate film, the hard coat agent containing inorganic particles used in Example 1 is applied so that the film thickness after curing becomes 3 μm. And dried at 40 ° C. for 60 seconds. Furthermore, 300 mJ / cm ² of ultraviolet rays were irradiated and cured to form a hard coat layer C on one side.

Next, a method for forming the light diffusion layer D ′ will be described.
The coating solution for light diffusion layer shown below was applied to the surface of the adhesion modified layer B opposite to the hard coat layer C and dried at 130 ° C. for 3 minutes.

(Composition of coating solution for light diffusion layer)
(A) Particle [26.3 parts by mass]
Spherical acrylic resin particles (Eposta-MA1010, manufactured by Nippon Shokubai Co., Ltd .; average particle size 10 μm)
(B) Resin [19.5 parts by mass]
Acrylic binder resin solution (Mitsubishi Rayon Co., Ltd., Dianar LR-1065; solid content concentration: 45% by mass)
(C) Solvent [54.2 parts by mass]
・ Methyl ethyl ketone [24.2 parts by mass]
・ Propylene glycol monomethyl ether [15.0 parts by mass]
・ Propylene glycol monomethyl ether acetate [15.0 parts by mass]

(Example 22)
In Example 1, an adhesion modified polyester film was obtained in the same manner as in Example 1 except that the coating amount was 0.02 g / m ² as the final solid content.
Next, a hard coat film in which a hard coat layer C containing inorganic fine particles is laminated on one surface is obtained in the same manner as in Example 1 on the surface of the adhesive modified layer B of the above-mentioned adhesive modified base film. It was.

(Example 23)
In Example 1, as a coating apparatus, the ratio of the capacity of the coating liquid tray, the capacity of the circulation tank, and the capacity of the preparation tank was the same as in Example 1 except that a coating apparatus having the following conditions was used. By the method, a roll of an adhesive modified polyester film having a film length of 2000 m, a width of 1000 mm, and a thickness of 125 μm was obtained.
(A) Capacity of coating liquid tray / capacity of circulation tank = 1/5
(B) Capacity of circulation tank / capacity of preparation tank = 1/50
(C) Roundness and cylindricity of application roll and metering roll: 6/1000 mm
(D) No pinch roll installed between coater and drying oven

  Next, a hard coat film in which a hard coat layer C containing inorganic fine particles is laminated on one surface is obtained in the same manner as in Example 1 on the surface of the adhesive modified layer B of the above-mentioned adhesive modified base film. It was.

  In Examples 1 to 23 and Comparative Examples 1 to 14, the composition and characteristics of the coating solution are shown in Table 1, the coating and drying conditions are shown in Table 2, the heat setting conditions are shown in Table 3, and the physical properties of the adhesion-modified base film. Table 4 shows the characteristics. Moreover, in the longitudinal direction and the width direction of the roll of the obtained adhesiveness-modified polyester film, the maximum value of PEs surface fraction, the minimum value, the maximum value of haze, the minimum value, the maximum value of adhesion to the hard coat layer, Table 5 shows the minimum values. In addition, about the blocking resistance, it was (circle) in all the measurement points.

  Since the hard coat film of the present invention is excellent in adhesion to the hard coat layer containing inorganic fine particles while maintaining high hardness, the prism lens sheet, the light diffusion film, the antireflection (AR) film, the transparent conductive material. It is suitable as a base material for optical functional films for displays such as a conductive film, an infrared absorbing film, and an electromagnetic wave absorbing film.

  Moreover, the hard coat film of this invention can be used also for the use for which concealment property is requested | required besides the optical functional film for a display. In that case, it is preferable to use a white film containing a white pigment or a cavity as the thermoplastic resin film of the substrate.

It is explanatory drawing of the phase image which observed the surface of the adhesive modification layer of the adhesive modification base film used for the hard coat film of this invention in the phase measurement mode of the scanning probe microscope. In the phase image of FIG. 1, it is explanatory drawing of the phase image which emphasized the outline of the interface of a light hue and a dark hue with image processing software. FIG. 3 is an explanatory diagram of a phase image in which the outline of the interface between the light hue and the dark hue in FIG. 2 is emphasized and the dark hue is filled with image processing software. FIG. 3 is an explanatory diagram illustrating a boundary line between a light hue and a dark hue in the phase image in which the outline of the interface between the light hue and the dark hue in FIG. 2 is emphasized. It is explanatory drawing which shows the height difference of the crack at the time of measuring the surface shape of the crack | wound attached to the surface of the adhesive property modification layer in wave mode using the three-dimensional non-contact surface shape measuring apparatus. In Example 1-23 and Comparative Examples 1, 4-6, and 8-14, the area ratio of the PEs phase on the surface of the adhesive modified layer does not correspond to the PEs mass ratio in the resin component of the adhesive modified layer. It is explanatory drawing which shows. It is explanatory drawing which shows the saucer of a coating liquid, the tank for circulation of the tank for circulation, arrangement | positioning of the tank for preparation, and the circulation path | route of a coating liquid. Explanatory drawing of the phase image which observed the cutting surface of the adhesive property modification layer at the time of cutting the hard coat film of this invention in the phase measurement mode of a scanning probe microscope, and color-enhanced and emphasized contrast It is. FIG. 9 is an explanatory diagram showing a range in which a phase separation structure is to be observed with two red lines in the phase image that has been subjected to the color equalization processing in FIG. 8. It is explanatory drawing of the phase image binarized with the image processing software about the phase image of FIG. It is explanatory drawing of the phase image which affixed the two red lines of FIG. 9 on the same position to the binarized phase image of FIG. 12 is an explanatory diagram of a phase image in which a portion not surrounded by two red lines in the phase image of FIG. 11 is painted red with image processing software. FIG.

Explanation of symbols

1: Dark hue (polyester phase mainly composed of copolymer polyester)
2: Light hue (polyurethane phase mainly composed of polyurethane)
3: Protrusions caused by particles 4: Lines highlighting the outline of the interface between light and dark hues 5: Profile curves of irregularities on the surface of the adhesive modified layer 6: Valley of scratches 7: Top of scratches 8: Implementation Example 1-23
9: Comparative Examples 1, 4-6, 8-14
10: Coater 11: Coating liquid tray 12: Die 13: Circulation tank 14: Preparation tank 15: Base film 16: Pinch roll 17: Hard coat layer C
18: Adhesive modified layer B
19: Thermoplastic resin film A
20: a line indicating the interface between the hard coat layer C and the adhesive modified layer B 21: a line moved in parallel from the interface 20 to the depth of 20 nm from the vertical direction inside the adhesive modified layer

Claims (7)

An adhesive modified base film in which an adhesive modified layer B containing a copolymerized polyester and polyurethane is formed on one or both sides of the thermoplastic resin film A, and an adhesive modified layer B on either side of the film A hard coat film comprising a layer structure of A / B / C or B / A / B / C, wherein a hard coat layer C containing inorganic fine particles is laminated on the surface of
Adhesive modified layer B has a micro phase separation structure or a nano phase separation structure of polyester (PEs) phase and polyurethane (PU) phase, and phase measurement of the cut surface of the hard coat film using a scanning probe microscope. When observed in the mode, the polyurethane phase (phase) of the adhesive modified layer B defined by the following formula (1) in the range from the interface between the adhesive modified layer B and the hard coat layer C to a depth of 20 nm. A hard coat film having an area ratio of 30% to 60%.
PU phase area ratio (%) = (PU phase area / measurement area) × 100 (1) An adhesive modified base film in which an adhesive modified layer B containing a copolymerized polyester and polyurethane is formed on one or both sides of the thermoplastic resin film A, and an adhesive modified layer B on either side of the film A hard coat film having a layer configuration of A / B / C or B / A / B / C, wherein a hard coat layer C containing inorganic fine particles is laminated on the surface of
The adhesive modification layer B has a microphase separation structure or a nanophase separation structure of a polyester (PEs) phase and a polyurethane (PU) phase, and the surface of the adhesion modification layer B using a scanning probe microscope. When observed in the phase measurement mode, the area ratio of the polyester phase (indicating a dark hue in the phase image) on the surface of the adhesive modified layer B defined by the following formula (2) is 35% within a range of 5 μm × 5 μm. Hard coat film characterized by being less than 90%.
PEs phase area ratio (%) = (PEs phase area / measurement area) × 100 (2)   The hard coat film according to claim 1 or 2, wherein the content of the inorganic fine particles in the hard coat layer C is 20 to 80% by mass.   3. The hard coat film according to claim 1, wherein the thermoplastic resin film does not contain particles or contains 50 ppm or less, and the adhesive modification layer contains 0.1 to 20 mass% of particles. .   The hard coat film according to claim 4, wherein the particles are silica particles.   The hard coat film according to claim 1, wherein the hard coat film is selected from a hard coat layer, a light diffusion layer, a prismatic lens layer, an electromagnetic wave absorption layer, a near-infrared shielding layer, and a transparent conductive layer on the surface opposite to the hard coat layer C. An optical functional film in which at least one optical functional layer is laminated.   An optical functional film in which an antireflection layer or an antifouling layer is laminated on the hard coat layer C of the hard coat film according to claim 1.