JP2014117904A - Laminate film, transparent conductive film, touch panel, and method for manufacturing laminate film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminate film having a hard coat layer, which eliminates interferential irregularity and has good adhesiveness between layers.SOLUTION: The laminate film comprises a polyester film, a polymer layer and a hard coat layer, successively laminated. The polyester film has a surface modified layer with a non-crystalline degree (noncrystalline degree/crystalline degree) of 5% or more on a surface side where the polymer layer is laminated. The surface modified layer has a thickness corresponding to a depth within a range of 40 to 330 nm from the surface of the polyester film. The polymer layer includes particles, while the hard coat layer includes a hydrolysis condensate of an alkoxysilane.

Description

  The present invention relates to a laminated film, a transparent conductive film, a touch panel, and a method for producing a laminated film. Specifically, the present invention relates to a laminated film in which a polyester film subjected to glow discharge treatment at Tg or more, a polymer layer containing particles, and a hard coat layer containing an alkoxysilane condensation polymer are sequentially laminated. Furthermore, this invention relates to the transparent conductive film and touch panel which have this laminated | multilayer film.

  In recent years, electronic devices equipped with a display device such as a liquid crystal display, a plasma display, and a touch panel display have been rapidly spread. These display devices are often provided on the surface layer of electronic devices, and are required to have scratch resistance and impact resistance. For this reason, the laminated film which has a hard-coat layer is provided in the surface layer of these display apparatuses. In order to provide the hard coat layer smoothly on the surface layer of the display device, the hard coat layer is provided on the polyester film, and the laminated film has a structure having the hard coat layer and the polyester film.

In general, since the polyester film and the hard coat layer are composed of different components, it is difficult to directly bond them together. For this reason, the polymer layer which functions as an easily bonding layer is provided on the polyester film, and the hard-coat layer is laminated | stacked on it, and it is set as the laminated film.
For example, Patent Document 1 discloses a laminated film having an undercoat layer (polymer layer) formed on a polyester film and a hard coat layer obtained by applying and curing a coating solution containing alkoxysilane or the like. ing. Here, it is proposed to add a metal oxide for the purpose of adjusting the refractive index of the polymer layer.

  Moreover, in order to improve the adhesiveness with the film laminated | stacked on a polyester film, performing surface treatments, such as a corona treatment and a glow discharge process, is known to a polyester film. For example, Patent Document 2 describes that a glow discharge treatment is performed on the surface of a polyester film, and it is proposed to improve the flatness of the surface of the polyester film and improve the adhesion of the laminated film by the glow discharge treatment. Has been. In Patent Document 2, the glow discharge treatment is performed at a temperature lower than the glass transition temperature (Tg) so that no curl or creaking occurs when the laminated film is rolled up.

JP 2012-116184 A Japanese Patent Laid-Open No. 9-230538

  In a laminated film having a hard coat layer as in Patent Document 1, there is a problem that interference unevenness occurs due to a difference in refractive index of each layer and a thickness unevenness of the hard coat layer, in order to eliminate such a difference in refractive index. In addition, fine particles have been added to the polymer layer. However, when fine particles are added to the polymer layer, there is a problem that the adhesion between the polymer layer and the polyester film deteriorates.

  By performing corona treatment or glow discharge treatment on the surface of the polyester film, the adhesion between the polymer layer and the polyester film can be enhanced to some extent. However, when the surface of the polyester film is subjected to glow discharge treatment under the conditions of Patent Document 2 and a polymer layer containing fine particles is laminated, it is clear from the examination by the present inventors that the adhesion between the layers is not sufficiently improved. became. Moreover, it became clear by examination of the present inventors that when the surface of the polyester film is subjected to corona treatment, the adhesiveness after wet heat aging significantly decreases.

That is, the conventional laminated film having a hard coat layer has a problem in that it cannot simultaneously solve the two problems of occurrence of unevenness in interference and reduction in adhesion between the layers of the laminated film.
Therefore, the present inventors provide a laminated film having a hard coat layer, in which interference unevenness is eliminated, and the adhesion between the layers is good, in order to solve such problems of the prior art. The study was advanced for the purpose.

As a result of intensive studies to solve the above problems, the present inventors have conducted a glow discharge treatment on the surface of the polyester film at Tg or higher to laminate a polymer layer containing particles. It was also found that excellent adhesion can be exhibited. Thereby, the present inventors succeeded in achieving both elimination of interference unevenness and improvement in adhesion in a laminated film having a hard coat layer, and completed the present invention.
Specifically, the present invention has the following configuration.

[1] A laminated film in which a polyester film, a polymer layer, and a hard coat layer are laminated in order, and the polyester film has an amorphous degree (non-crystallinity / crystallinity) on the side where the polymer layer is laminated. 5% or more of the surface modified layer, the surface modified layer has a thickness from the surface of the polyester film to any depth within the range of 40 to 330 nm, the polymer layer, The laminated film includes particles, and the hard coat layer includes a hydrolysis condensate of alkoxysilane.
[2] The laminated film according to [1], wherein the thickness of the polymer layer is 200 nm or less, and the average particle diameter of the particles is 0.65 times or less of the thickness of the polymer layer.
[3] The laminated film according to [1] or [2], wherein the average particle diameter of the particles is 5 to 130 nm or less.
[4] The laminated film according to any one of [1] to [3], wherein the particles have a refractive index of 1.60 to 3.00.
[5] The laminated film according to any one of [1] to [4], wherein the particles are metal oxide particles.
[6] The laminated film according to any one of [1] to [5], wherein the particles are tin oxide or zirconium oxide.
[7] The laminated film according to any one of [1] to [6], wherein the particles are contained in an amount of 40 to 80% by mass based on the solid content contained in the polymer layer.
[8] The hydrolyzed condensate of alkoxysilane is a hydrolyzed condensate of an epoxy group-containing alkoxysilane and an epoxy group-free alkoxysilane, according to any one of [1] to [7], Laminated film.
[9] The laminated film according to any one of [1] to [8], wherein the laminated film has a b ^* value of −2.0 to 2.0.
(Here, the b ^* value represents the b ^* value in the CIE 1976 L ^* a ^* b ^* color system.)
[10] The laminated film according to any one of [1] to [9], wherein the haze of the laminated film is 2% or less.
[11] The laminated film according to any one of [1] to [10], wherein the polyester film has a refractive index of 1.60 to 1.75.
[12] The laminated film according to any one of [1] to [11], wherein the polymer layer has a refractive index of 1.52 to 1.69.
[13] A step of performing glow discharge treatment on the surface of the polyester film heated to Tg or more, a step of forming a polymer layer containing particles on the surface of the polyester film subjected to glow discharge treatment, and the polymer layer A method for producing a laminated film, comprising a step of forming a hard coat layer containing a hydrolysis condensate of alkoxysilane on the substrate.
[14] The method for producing a laminated film according to [13], wherein the step of forming the hard coat layer includes a step of hydrolyzing the alkoxysilane and a step of condensing the hydrolyzed alkoxysilane.
[15] A laminated film produced by the production method according to [13] or [14].
[16] A transparent conductive film having the laminated film according to any one of [1] to [12] and [15].
[17] A touch panel having the laminated film according to any one of [1] to [12] and [15].

  According to the present invention, in a laminated film having a hard coat layer, the occurrence of interference unevenness can be suppressed and the adhesion between the layers of the laminated film can be enhanced. The laminated film of the present invention is suitably used for applications such as a transparent conductive film and a touch panel because interference unevenness is eliminated and adhesion between layers is good.

FIG. 1 is a cross-sectional view showing an example of the laminated film of the present invention. FIG. 2 is a TEM observation image of the surface of the polyester film.

  Hereinafter, the present invention will be described in detail. The description of the constituent elements described below may be made based on representative embodiments and specific examples, but the present invention is not limited to such embodiments. In the present specification, a numerical range expressed using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.

(Laminated film)
The present invention relates to a laminated film in which a polyester film, a polymer layer, and a hard coat layer are sequentially laminated. The polyester film has a surface modification layer having an amorphous degree (non-crystallinity / crystallinity) of 5% or more on the surface side on which the polymer layers are laminated. It has a thickness up to any depth within the range of 330 nm. The polymer layer contains particles in addition to the binder constituting the polymer layer, and the hard coat layer contains a hydrolysis-condensation product of alkoxysilane.

FIG. 1 is a cross-sectional view showing an example of a laminated film 10 of the present invention. As shown in FIG. 1, the laminated film 10 has a configuration in which a polyester film 1, a polymer layer 2, and a hard coat layer 4 are laminated in order. The polyester film 1 has a surface modification layer 5 on the surface side on which the polymer layer 2 is laminated. The surface modification layer 5 is formed so as to have a certain thickness from the surface of the polyester film 1 and is formed facing the polymer layer 2.
Further, the polymer layer 2 has particles 3. As shown in FIG. 1, the particles 3 preferably have an average particle size of a certain value or less with respect to the thickness of the polymer layer 2, and are formed by protruding the particles 3 on the surface of the polymer layer 2. It is preferable that there are few irregularities. That is, in the present invention, the surface shape of the polymer layer 2 is preferably flat. Thereby, scattering of light can be reduced and the color of the laminated film can be improved.

  In the present invention, since the polymer layer contains particles, it is possible to suppress the occurrence of interference unevenness caused by the difference in refractive index between the polyester film and the hard coat layer. Furthermore, in the present invention, the surface of the polyester film is subjected to glow discharge treatment at Tg or more to form a surface modified layer, thereby improving the adhesion between the polymer layer and the polyester film and between the polymer layer and the hard coat layer. It is also possible to improve the adhesion. That is, in the laminated film of the present invention, there is no occurrence of interference unevenness, and even when the laminated film is used for a long time, problems such as delamination do not occur.

Furthermore, in the present invention, the thickness of the polymer layer is preferably 200 nm or less, and the average particle diameter of the particles is preferably 0.65 times or less of the thickness of the polymer layer. The b ^* value and haze value of the polymer layer can be reduced by keeping the average particle size of the particles used in the present invention within a certain range. Thereby, coloring of the whole laminated | multilayer film can be suppressed, and color can be improved. Moreover, the laminated film excellent in transparency can be obtained.
When particles having a small average particle diameter are used, the adhesion between layers tends to be further deteriorated. However, in the present invention, by performing glow discharge treatment on the surface of the polyester film at Tg or more, even when particles having a small particle diameter are used, the interlayer adhesion can be kept good. Thereby, while maintaining adhesiveness, interference unevenness is eliminated, and a laminated film having a small b ^* value and a low haze value can be obtained.

The b ^* value of the laminated film of the present invention is preferably −2.0 to 2.0, more preferably −1.5 to 1.5, and −1.2 to 1.2. Is more preferable. In the present invention, the degree of yellowish coloring is represented by the b ^* value in the CIE 1976 L ^* a ^* b ^* color system.
Moreover, it is preferable that the haze value of the laminated | multilayer film of this invention is 2% or less, It is more preferable that it is 1.5% or less, It is further more preferable that it is 1% or less.
By setting the b ^* value and haze value of the laminated film within the above ranges, when the laminated film of the present invention is incorporated in a display device such as a touch panel, the coloring of the image can be reduced and the visibility is good. Can be.

(Polyester film)
The laminated film of the present invention includes a polyester film. The polyester film used in the present invention functions as a support for supporting the polymer layer and the hard coat layer.

  The polyester film in the present invention refers to a film whose main component is polyester, and usually refers to a film in which 98% by mass or more of the resin component is polyester, and preferably 90% by mass of the component constituting the polyester film is polyester. Is a film. The kind in particular of polyester is not restrict | limited, A well-known thing can be used as polyester. Specific examples include polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, and polybutylene naphthalate. Among them, it is particularly preferable to use polyethylene terephthalate (PET) from the viewpoint of cost and mechanical strength.

  The polyester film according to the present invention has a surface modified layer. The surface modified layer is a layer formed on the surface layer of the polyester film, and means a layer having an amorphous degree (non-crystalline degree / crystalline degree) of 5% or more. The surface modification layer has a thickness from the surface of the polyester film to any depth within the range of 40 to 330 nm. The surface modification layer preferably has a thickness up to any depth within the range of 330 nm, more preferably within the range of 50 to 220 nm, and within the range of 50 to 200 nm. Further preferred.

The non-crystallinity indicates the ratio of the non-crystalline part to the total of the non-crystalline part and the crystal part (content ratio of the non-crystalline part). The non-crystal part contains many Gauche crystal molecules, and the crystal part contains many trans-type crystal molecules. For this reason, the content rate of the non-crystal part and the crystal part can be calculated by the content rate of the crystal molecules. Specifically, the content ratio of the amorphous part and the crystalline part can be calculated by obtaining the spectrum of the surface modified layer by the ATR-IR method. A value obtained by dividing the amorphous degree (1175 cm ⁻¹ ) by the spectrum of the crystallinity spectrum (1341 cm ⁻¹ ) was defined as the amorphous degree (non-crystalline degree / crystalline degree).

  The non-crystallinity (non-crystallinity / crystallinity) of the surface modified layer of the polyester film is preferably 5% or more, more preferably 5 to 8.3%, and more preferably 5 to 8%. Further preferred. By setting the amorphousness of the surface modified layer within the above range, it is possible to improve the oligomer block property and adhesion while preventing yellowing of the polyester film.

FIG. 2 shows a TEM observation image representing the surface state of the polyester film according to the invention. FIG. 2A shows a TEM observation image of the surface of the polyester film not subjected to glow discharge treatment. FIG.2 (b) has shown the TEM observation image of the surface of the polyester film which performed the glow discharge process. A portion indicated by an arrow in FIGS. 2A and 2B is the surface of the polyester film. In FIG. 2B, it can be seen that the range indicated by A is discolored black. This represents the surface modified layer. As can be seen from FIG. 2A, the polyester film not subjected to the glow discharge treatment does not have a surface modified layer. The thickness of the surface modification layer is the distance indicated by A in FIG. 2B, and the average value of the distance indicated by the arrow and A is referred to as the thickness of the surface modification layer.
The thickness of the surface modification layer can be determined by osmium staining the PET surface and observing a cross-section TEM. It is said that the portion where the chromaticity is L = 30 or less is dyed black, and this is a modified portion. In the untreated case (FIG. 2 (a)), almost nothing can be seen, but it can be seen that when the glow discharge treatment is performed, the surface is stained black (FIG. 2 (b)).

By heating the polyester film to Tg or higher and performing glow discharge treatment, the surface modified layer as described above can be formed on the surface of the polyester film.
The glow discharge treatment is a method called vacuum plasma treatment or glow discharge treatment, in which plasma is generated by discharge in a gas (plasma gas) in a low-pressure atmosphere to treat the substrate surface. The low-pressure plasma used in the process of the present invention is a non-equilibrium plasma generated under conditions where the plasma gas pressure is low. The treatment of the present invention is performed by placing a film to be treated in this low-pressure plasma atmosphere.
In the glow discharge treatment of the present invention, as a method for generating plasma, methods such as direct current glow discharge, high frequency discharge, and microwave discharge can be used. The power source used for discharging may be direct current or alternating current. When alternating current is used, a range of about 30 Hz to 20 MHz is preferable. When alternating current is used, a commercial frequency of 50 or 60 Hz may be used, or a high frequency of about 10 to 50 kHz may be used. A method using a high frequency of 13.56 MHz is also preferable.

  As the plasma gas used in the glow discharge treatment of the present invention, an inorganic gas such as oxygen gas, nitrogen gas, water vapor gas, argon gas, helium gas can be used, and in particular, oxygen gas or oxygen gas and argon gas The mixed gas is preferable. Specifically, it is desirable to use a mixed gas of oxygen gas and argon gas. When oxygen gas and argon gas are used, the ratio between the two is preferably a partial pressure ratio of oxygen gas: argon gas = 100: 0 to 30:70, more preferably 90:10 to 70:30. In addition, a method in which a gas such as water entering the processing container due to a leak or water vapor coming out of the object to be processed is used as the plasma gas without introducing a gas into the processing container.

As the pressure of the plasma gas, a low pressure at which non-equilibrium plasma conditions are achieved is necessary. The specific plasma gas pressure is preferably in the range of about 0.005 to 10 Torr, more preferably about 0.008 to 3 Torr. When the pressure of the plasma gas is less than 0.005 Torr, the effect of improving adhesiveness may be insufficient. Conversely, when the pressure exceeds 10 Torr, the current may increase and the discharge may become unstable.
The plasma output cannot be generally specified depending on the shape and size of the processing vessel, the shape of the electrode, and the like, but is preferably about 100 to 10000 W, more preferably about 2000 to 10000 W.

  The treatment time of the glow discharge treatment of the present invention is preferably 0.05 to 100 seconds, more preferably about 0.5 to 30 seconds. If the treatment time is less than 0.05, the adhesion improving effect may be insufficient. Conversely, if the treatment time exceeds 100 seconds, problems such as deformation and coloring of the film to be treated may occur.

Discharge treatment intensity of the glow discharge treatment of the present invention will depend on the plasma power and treatment time, preferably in the range of 0.01~10kV · A · min / m ^2, 0.1~7kV · A · min / m ² Gayori preferable. Discharge treatment intensity that is sufficient adhesion improving effect of the 0.01 kV · A · min / m ² or more is obtained, and such deformation and coloration of the processed film by a 10 kV · A · min / m ² or less You can avoid problems.

  In the glow discharge treatment of the present invention, it is preferable to heat a polyester film that is a film to be treated in advance. The surface of the polyester film is preferably heated to a temperature equal to or higher than Tg and then subjected to glow discharge treatment. That is, during the glow discharge treatment, the surface of the polyester film is preferably heated to Tg (69 ° C.) or higher. The surface of the polyester film is more preferably heated within a temperature range of Tg to 200 ° C, and more preferably heated within a temperature range of Tg to 150 ° C. By performing glow discharge treatment after heating within the above temperature range, excellent adhesion can be exhibited even when a polymer layer containing particles is laminated on a polyester film. Moreover, by performing the glow discharge treatment after heating within the above temperature range, it is possible to prevent the oligomer from being deposited on the polyester film and to prevent the polyester film from being whitened. Furthermore, it can suppress that a polyester film yellows by performing a glow discharge process after heating in the said temperature range.

  Specific methods for raising the temperature of the film to be treated in vacuum include heating with an infrared heater, heating method by contacting with a hot roll, and the like.

  The polyester film in the present invention is preferably biaxially stretched. Biaxial stretching refers to stretching in both directions by regarding the width direction and the longitudinal direction of the film as uniaxial. Thus, the biaxially stretched polyester film has very good mechanical strength because the molecular orientation in the biaxial direction is sufficiently controlled. The draw ratio is not particularly limited, but the draw ratio in one direction is preferably 1.5 to 7 times, more preferably 2 to 5 times. In particular, a polyester film that has been biaxially stretched at a stretching ratio of 2 to 5 times per uniaxial direction has a very excellent mechanical strength because the molecular orientation is controlled more efficiently and effectively. Suitable as a film. By setting the draw ratio of the polyester film to 1.5 times or more, sufficient mechanical strength can be obtained as compared with the case of less than 1.5 times. Further, by setting the draw ratio to 7 times or less, a uniform thickness can be obtained as compared with the case where the draw ratio exceeds 7 times.

  The thickness of the polyester film is preferably 30 to 400 μm, and more preferably 100 to 250 μm. The polyester film in the present invention may consist of only one layer, or may be a laminate of two or more layers of polyester film (for example, co-flow film, co-extruded film, etc.). When the polyester film in this invention consists of two or more layers, the total thickness becomes the said range.

The polyester film according to the present invention preferably has a b ^* value of the polyester film of b ^* = 0.006t + 0.55 or less. The b ^* value is preferably b ^* = 0.006t + 0.38 or less, and more preferably b ^* = 0.006t + 0.25 or less. In the above formula, t represents the thickness (μm) of the polyester film. By making b ^* value below the said formula, yellowing of a polyester film can be prevented and the transparency of a polyester film can be improved.

In the present invention, the polyester film preferably has a b ^* value of 1.75 or less, more preferably 1.6 or less, and even more preferably 1.45 or less. The thickness of the polyester film used in the present invention is not particularly limited, but when the thickness of the polyester film is 10 to 100 μm, the b ^* value is preferably 1.2 or less, and 1.0 or less. More preferably, it is 0.9 or less. Moreover, when the film thickness of a polyester film is 100-150 micrometers, it is preferable that b ^* value is 1.45 or less, It is more preferable that it is 1.3 or less, It is further more preferable that it is 1.15 or less. Furthermore, when the film thickness of the polyester film is 150 to 200 μm, the b ^* value is preferably 1.75 or less, more preferably 1.6 or less, and even more preferably 1.45 or less.

Furthermore, in the present invention, the amount of change (Δb) between the b ^* value before the glow discharge treatment and the b ^* value after the glow discharge treatment is preferably 0.3 or less. Or less, more preferably 0.1 or less. A small change in the b ^* value before and after the glow discharge treatment indicates that no yellowing has occurred in the glow discharge treatment. In this invention, the polyester film in which yellowing was suppressed can be obtained by making the variation | change_quantity of b ^* value before and behind a glow discharge process below into the said upper limit.

  Although the value of the refractive index of the polyester film varies depending on the material used, it is preferably 1.60 to 1.75, and more preferably 1.62 to 1.68. When the refractive index is within the above range, it is possible to obtain a laminated film having excellent rigidity as a support for the laminated film and having excellent transparency. In the present invention, the refractive index represents a measured value at a wavelength of 660 nm.

  The polyester film may contain other additives as long as they do not depart from the spirit of the present invention, and examples thereof include antioxidants and ultraviolet inhibitors.

(Polymer layer)
The laminated film of the present invention includes a polymer layer. The polymer layer used for this invention functions as an easily bonding layer which adhere | attaches a polyester film and a hard-coat layer. The polymer layer is preferably formed on at least one surface of the polyester film, but may be formed on both sides of the polyester film. Further, the polymer layer may have a single layer structure or a laminated structure of two or more layers.

  The thickness of the polymer layer used in the present invention is preferably 200 nm or less, more preferably 180 nm or less, and further preferably 150 nm or less. Further, the thickness of the polymer layer is preferably 50 nm or more, and more preferably 80 nm or more. By setting the thickness of the polymer layer to the upper limit value or less, the surface state of the polymer layer can be made to be in a better state, and interference unevenness can be suppressed. Furthermore, when the polymer layer is formed by a coating process, it is possible to suppress an increase in the amount of coating solution used to prevent an increase in drying time and to suppress an increase in cost. Moreover, the adhesiveness at the time of a polymer layer functioning as an easily bonding layer can be improved because the thickness of a polymer layer shall be more than the said lower limit. In addition, when a polymer layer is made into the laminated structure of two or more layers, it is preferable that the sum total of the thickness of laminated structure is in said thickness range.

  The refractive index of the polymer layer used in the present invention is preferably adjusted according to the refractive index of the polyester film and the hard coat layer. For example, when the refractive index of the polyester film is 1.60 to 1.75 and the refractive index of the hard coat layer is 1.40 to 1.49, the refractive index of the polymer layer is 1.50 to 1.61. It is preferable that it is 1.52-1.59, and it is more preferable. By setting it as the said range, it can suppress that an interference nonuniformity arises in a laminated | multilayer film.

<Particle>
The polymer layer used in the present invention contains particles. The particles contained in the polymer layer are added for the purpose of adjusting the refractive index of the polymer layer. There may be only one type of particles used in the present invention, or two or more types.

  The average particle diameter of the particles used in the present invention is 0.65 times or less with respect to the thickness of the polymer layer. The average particle size of the particles is more preferably 0.50 times or less, and still more preferably 0.40 times or less. By setting it as the said range, an unevenness | corrugation becomes difficult to be formed in the surface of a polymer layer, scattering of light can be reduced, and the color of a laminated | multilayer film can be made favorable. The lower limit of the average particle diameter is not particularly limited, but is preferably 0.05 times or more.

  Specifically, the average particle diameter of the particles is preferably 5 to 130 nm. The average particle size of the particles is more preferably 5 to 80 nm, and further preferably 5 to 50 nm. By making the average particle diameter of the particles not more than the above upper limit value, the influence of light being scattered by the particles becomes small, and by making it not less than the above lower limit value, the particles can be prevented from agglomerating and becoming huge. it can.

Here, the average particle diameter of the particles in the present invention was measured using a laser diffraction / scattering particle size distribution measuring apparatus LA910 (manufactured by Horiba, Ltd.) using an aqueous dispersion of particles, and expressed in median diameter. .
In addition, after the production of the laminated film of the present invention, the average particle size of the particles contained in the polymer layer of the laminated film of the present invention is the same as that of the particles contained in the polymer layer after dissolving only the polymer layer in the solvent. It can measure using the said apparatus after preparing an aqueous dispersion.

  The refractive index of the particles used in the present invention is preferably 1.60 to 3.00, more preferably 1.80 to 2.80, and even more preferably 1.90 to 2.60. . By adjusting the refractive index of the particles within the above range, the refractive index of the polymer layer can be easily adjusted. In addition, it is preferable to adjust the refractive index of particle | grains suitably according to the refractive index of a hard-coat layer and a polyester film. In addition, the refractive index of particle | grains represents the measured value in wavelength 660nm.

  It is preferable that the particle | grains in this invention are contained 40-80 mass% with respect to solid content of a polymer layer. It is preferable that it is 45-75 mass%, and it is more preferable that it is 50-70 mass%. By setting it as the said range, while making it easy to adjust the refractive index of a polymer layer, particle | grains do not overflow from a polymer layer, but it can make it difficult to form the unevenness | corrugation on the surface of a polymer layer.

  Examples of the particles used in the present invention include conductive metal particles and metal oxide particles, and metal oxide particles are preferable.

  Examples of the conductive metal particles include particles of antimony, selenium, titanium, tungsten, tin, zinc, indium and the like.

  Examples of the particles used in the present invention include particles containing any one of tin oxide, zirconium oxide and titanium oxide as a main component. Here, the particles in the present invention contain any one of tin oxide, zirconium oxide and titanium oxide as a main component. Among these, it is preferable to use tin oxide or zirconium oxide. In the present invention, the blending amount of any one of tin oxide, zirconium oxide and titanium oxide is preferably 80% by mass or more.

As the tin oxide, tin (IV) oxide having a SnO ₂ composition is preferably used. In the case of using tin oxide, the use of tin oxide doped with antimony or the like has the effect of reducing the surface resistivity of the laminated film and preventing impurities such as dust from adhering because of its conductivity. Since it is obtained, it is preferable. Commercially available tin oxide doped with antimony can be used, and FS-10D, SN-38F, SN-88F, SN-100F, TDL-S, TDL-1 (all of which are Ishihara Sangyo) Etc.).

On the other hand, in order to prevent malfunction of the touch panel, inorganic oxide fine particles having no conductivity may be preferably used. For example, tin oxide prepared so as not to reduce the surface resistance without doping antimony or the like into tin oxide can be suitably used. Also, tin oxide doped with phosphorus (for example, manufactured by Mitsubishi Materials Electronics Chemical Co., Ltd., EP SPDL-2, an aqueous dispersion of P-doped SnO _{2 having} a particle size of 130 nm) and the like.
Among these, in the present invention, it is particularly preferable to use tin oxide not doped with antimony as tin oxide.

Zirconium oxide has a composition of ZrO _2, for example, NZS-20A, NZS-30A , OZ-S30K, ZR-30BF, ZR-30BS, ZR-40BL ( both, manufactured by Nissan Chemical Industries, Ltd.) and SZR -CW (manufactured by Sakai Chemical Industry Co., Ltd.) can be mentioned, and these can also be suitably used in the present invention.

As titanium oxide, titanium oxide (IV) having a composition of TiO ₂ is preferably used. Titanium oxide has a rutile type (tetragonal high-temperature type), anatase type (tetragonal low-temperature type), etc. depending on the difference in crystal structure, but is not particularly limited. Further, titanium oxide subjected to surface treatment may be used. Examples of the titanium oxide used in the present invention include IT-S, IT-O, IT-W (all manufactured by Idemitsu Kosan Co., Ltd.), TTO-W-5 (manufactured by Ishihara Sangyo Co., Ltd.), and the like. And can also be suitably used in the present invention.

  The shape of the particles used in the present invention may be acicular or spherical, but is preferably spherical. In addition, even when the shape of the particles used in the present invention is not perfectly spherical, the average particle diameter of the particles can be measured by the above-described method. However, when the shape of the particles is not perfectly spherical, When it is difficult to measure by the measuring method, the diameter of a circle circumscribing such shaped particles can be determined as the particle diameter in the present invention.

<Binder>
The polymer layer includes a binder suitable for increasing the adhesion between the polyester film and the hard coat layer. The binder used in the polymer layer is not particularly limited as long as it enhances the adhesion between the polyester film and the hard coat layer, but is at least one of polyolefin, acrylic, polyurethane, polyester, or rubber-based resin. It is preferable. Among them, it is preferable to use a polyolefin resin, and 30% by mass or more is preferably polyolefin, 50% by mass or more is preferably polyolefin, and 90% by mass or more is based on the total binder contained in the polymer layer. More preferably, it is a polyolefin. The elastic modulus of the polymer layer is preferably 50 MPa to 5 GPa, more preferably 100 MPa to 1 GPa. In addition, a binder having water solubility or water dispersibility is particularly preferable from the viewpoint that the load on the environment is small.

    A polyolefin having a polar group such as a carboxyl group is preferred as an ionomer of a polyolefin having a polar group. It may be used by dissolving in an organic solvent, or an aqueous dispersion may be used. However, since the environmental load is small, it is preferable to attach with an aqueous system using an aqueous dispersion. A commercially available product may be used as the aqueous dispersion and is not particularly limited. Examples of those that can be preferably used in the present invention include Chemipearl S75N (manufactured by Mitsui Chemicals), Arrow Base SE1200. Arrowbase SB1200 (above, manufactured by Unitika Ltd.), Hitech S3111, S3121 (above, produced by Toho Chemical Co., Ltd.), and the like. Only one type of polyolefin may be included, or two or more types may be included.

As the acrylic, acrylic containing methacrylate, ethyl acrylate and other copolymerization components is preferable, and those described in paragraphs [0145] to [0146] of JP 2012-101449 A can be used. Moreover, you may use a commercial item, and specifically, Daicel Finechem Co., Ltd. AS-563A etc. are mentioned.
The acrylic preferably has a glass transition temperature of −50 to 120 ° C., more preferably −30 to 100 ° C. The weight average molecular weight of acrylic is preferably 3000 to 1000000.

  The polyurethane is preferably composed of a polyol, a polyisocyanate, a chain extender, a crosslinking agent and the like, and those described in paragraph [0035] of JP2012-056220A can be used.

  As polyester, the polyester obtained from the following polybasic acid component and diol component can be used. That is, as the polyvalent base component, for example, terephthalic acid, isophthalic acid, phthalic acid, phthalic anhydride, 2,6-naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, adipic acid, sebacic acid, trimellitic acid, Examples include pyromellitic acid, dimer acid, and 5-sodium sulfoisophthalic acid. As the polyester constituting the polymer binder, it is preferable to use a copolymerized polyester using two or more kinds of dicarboxylic acid components. The polyester may contain an unsaturated polybasic acid component such as maleic acid or itaconic acid, or a hydroxycarboxylic acid component such as p-hydroxybenzoic acid, if it is in a slight amount.

  Polyester diol components include ethylene glycol, 1,4-butanediol, diethylene glycol, dipropylene glycol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, xylene glycol, dimethylolpropane, and the like, poly (ethylene oxide) ) Glycol and poly (tetramethylene oxide) glycol.

<Crosslinking agent>
The polymer layer used in the present invention may contain a crosslinking agent. Examples of the crosslinking agent include epoxy-based, isocyanate-based, melamine-based, carbodiimide-based, and oxazoline-based crosslinking agents. Among these, carbodiimide type crosslinking agents and oxazoline type crosslinking agents are preferably used.

As the carbodiimide-based crosslinking agent, a compound having a plurality of carbodiimide structures in the molecule is preferable. By including such a compound, the adhesiveness between the hard coat layer and the polymer layer tends to be improved when the hard coat layer is provided. A compound having a plurality of carbodiimide groups in the molecule can be used without particular limitation. Polycarbodiimide is usually synthesized by condensation reaction of organic diisocyanate, but the organic group of the organic diisocyanate used in this synthesis is not particularly limited, either aromatic or aliphatic, or a mixture thereof It can be used. From the viewpoint of reactivity, an aliphatic type is particularly preferable. As the synthetic raw material, organic isocyanate, organic diisocyanate, organic triisocyanate and the like are used. Examples of the organic isocyanate include those described in paragraph [0024] of JP2009-220316A.
Moreover, the carbodiimide type | system | group crosslinking agent used for this invention may use a commercial item, and specifically, Carbodilite V-02-L2 by Nisshinbo Co., Ltd. is mention | raise | lifted.

  As the oxazoline-based crosslinking agent, those described in paragraph [0078] of JP 2012-231029 A can be used. Commercial products may also be used, and examples include EPOCROS K2010E, K2020E, K2030E, WS500, WS700 and the like manufactured by Nippon Shokubai Chemical Industry Co., Ltd.

  The crosslinking agent used in the present invention is preferably added in the range of 1 to 200% by mass, more preferably in the range of 5 to 100% by mass with respect to the total amount of solids in the polymer layer. . By making the addition amount 1% by mass or more, the particles contained in the polymer layer can be effectively prevented from peeling off. On the other hand, when the addition amount is 200% by mass or less, the surface shape tends to be further improved. Two or more types of crosslinking agents may be included, and when two or more types are included, the total amount is preferably within the above range.

<Surfactant>
The polymer layer used in the present invention may have a surfactant to reduce repellency and the like when a functional layer such as a hard coat layer is applied to the surface of the polymer layer.
Examples of the surfactant include known anionic, nonionic, and cationic surfactants, and anionic and nonionic surfactants are preferably used. As the surfactant, for example, those described in “Surfactant Handbook” (issued in 1960 by Ichiro Nishi, Ichiichiro Imai, Shozo Kasai Sangyo Tosho Co., Ltd., 1960) can be used.

  Examples of commercially available anionic surfactants include Rapisol A-90, Rapisol A-80, Rapisol BW-30, Rapisol B-90, Rapisol C-70 (manufactured by NOF Corporation), NIKKOL OTP-100 ( Nikko Chemical Co., Ltd.), Koha Cool ON, Koha Cool L-40, Phosphanol 702 (Toho Chemical Industry Co., Ltd.), View Light A-5000, View Light SSS (Sanyo Chemical Industries Co., Ltd.), etc. Can be mentioned.

  Examples of commercially available nonionic surfactants include, for example, NAROACTY CL-95 (manufactured by Sanyo Chemical Industries, Ltd.), Risolex BW400 (manufactured by Higher Alcohol Industry Co., Ltd.), EMALEX ET-2020 (manufactured by Nippon Emulsion Co., Ltd.). ), Unilube 50MB-26, Nonion IS-4 (manufactured by NOF Corporation) and the like.

<Antistatic agent>
The polymer layer used in the present invention may have an antistatic agent in order to prevent the polymer layer from being charged by static electricity or the like.
The type of the antistatic agent is not particularly limited. For example, an electron conductive polymer such as polyaniline and polypyrrole, an ion conductive polymer having a carboxyl group or a sulfonic acid group in the molecular chain, conductive fine particles, etc. Is mentioned. Among these, the conductive tin oxide fine particles described in JP-A-61-20033 can be preferably used from the viewpoints of conductivity and transparency.

The addition amount of the antistatic agent is preferably added so that the surface resistivity of the polymer layer measured in an atmosphere of 25 ° C. and a relative humidity of 30% is 1 × 10 ⁵ Ω or more and 1 × 10 ¹³ Ω or less. The surface resistivity can be suppressed 1 × 10 and a ⁵ Omega or lower the amount of the antistatic agent tends to transparency improvement of the laminated film, by the following 1 × 10 ¹³ Omega, dust It tends to be more difficult to adhere.

(Hard coat layer)
The laminated film of the present invention includes a hard coat layer. The hard coat layer used in the present invention is laminated on the polymer layer, and is laminated on the opposite surface of the polyester film via the polymer layer. The laminated film of the present invention is a laminated film having a hard coat layer and functions as a hard coat film. The laminated film of the present invention may have a hard coat layer only on one side of the polyester film, or may have both sides. Moreover, when it has a hard-coat layer on both surfaces, a hard-coat layer may be the same structure and a mutually different structure.

  The hard coat layer used in the present invention is preferably mainly composed of a curable resin having high chemical resistance and scratch resistance. The hard coat layer may be formed by curing a curable resin by irradiating ultraviolet rays or an electron beam, but is preferably formed by condensing and curing an alkoxysilane hydrolyzate. When the hard coat layer is formed by condensing a hydrolyzate of alkoxysilane, it can be formed by applying an aqueous composition containing the hydrolyzate of alkoxysilane and drying it. For this reason, a hard-coat layer can be formed without using an organic solvent etc., and the load to an environment can be reduced significantly.

  When the hard coat layer is formed by condensing an alkoxysilane hydrolyzate, the thickness of the hard coat layer can be controlled by adjusting the coating amount of the aqueous composition. From the viewpoint of the hardness of the obtained hard coat layer, the thickness is more preferably constant in the range of 0.3 to 12 μm. If the thickness is less than 0.3 μm, sufficient hardness may not be exhibited and the function as a hard coat layer may not be obtained. If the thickness is greater than 12 μm, the internal stress of the hard coat layer increases and deformation such as curling May occur. A more preferable thickness range is 0.5 to 10 μm.

The refractive index of the hard coat layer in the present invention preferably satisfies n ₁ ≦ n _HC ± 1.0 when the refractive index of the hard coat layer is n _HC and the refractive index of the polymer layer is n _1. .

<Alkoxysilane>
The hard coat layer used in the present invention is formed by condensing a hydrolyzate of alkoxysilane. Alkoxysilane has a hydrolyzable group, and when this hydrolyzable group is hydrolyzed in an acidic aqueous solution, silanol is generated, and silanols condense with each other, so that a hydrolyzed condensate of alkoxysilane ( Oligomer) is produced. That is, the hard coat layer contains a hydrolysis condensate of alkoxysilane.
The hard coat layer may contain a portion of alkoxysilane or a hydrolyzate thereof in addition to the alkoxysilane hydrolysis condensate.
The hard coat layer used in the present invention can be formed by applying an aqueous composition containing alkoxysilane and drying it. The use of an aqueous composition is also preferable from the viewpoint of reducing environmental pollution caused by VOC (volatile organic compounds).

  Moreover, it is preferable to use an epoxy group-containing alkoxysilane and an epoxy group-free alkoxysilane as the alkoxysilane. Each of the epoxy group-containing alkoxysilane and the epoxy group-free alkoxysilane has a hydrolyzable group. Therefore, the hydrolyzable group is hydrolyzed in an acidic aqueous solution, and the resulting silanol is condensed to contain an epoxy group. A hydrolysis condensate of alkoxysilane and epoxy group-free alkoxysilane is produced. That is, the hard coat layer used in the present invention includes a hydrolysis condensate of an epoxy group-containing alkoxysilane and an epoxy group-free alkoxysilane.

  In the aqueous composition for forming the hard coat layer, the ratio of the epoxy group-containing alkoxysilane to the total alkoxysilane is preferably 20 to 85% by mass. The proportion of the epoxy group-containing alkoxysilane may be 20% by mass or more, preferably 25% by mass or more, and more preferably 30% by mass or more. Moreover, the ratio for which an epoxy-group-containing alkoxysilane accounts may be 85 mass% or less, it is preferable that it is 80 mass% or less, and it is more preferable that it is 75 mass% or less. By setting the ratio of the epoxy group-containing alkoxysilane to the total alkoxysilane within the above range, the stability of the aqueous composition can be increased, and further, a hard coat layer having strong alkali resistance can be formed. .

  The epoxy group-containing alkoxysilane is an alkoxysilane having an epoxy group. Any epoxy group-containing alkoxysilane may be used as long as it has one or more epoxy groups in one molecule, and the number of epoxy groups is not particularly limited. In addition to the epoxy group, the epoxy group-containing alkoxysilane may further have a group such as an alkyl group, an amide group, a urethane group, a urea group, an ester group, a hydroxy group, or a carboxyl group.

  Examples of the epoxy group-containing alkoxysilane used in the present invention include 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltriethoxysilane, and 2- (3,4-epoxy. Cyclohexyl) ethyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethylmethyldimethoxysilane, 2- (3,4-epoxycyclohexyl) ethylmethyldiethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3- Examples thereof include glycidoxypropyltriethoxysilane. Examples of commercially available products include KBE-403 (manufactured by Shin-Etsu Chemical Co., Ltd.).

  The epoxy group-free alkoxysilane is an alkoxysilane having no epoxy group. The epoxy group-free alkoxysilane may be an alkoxysilane having no epoxy group, and may have a group such as an alkyl group, an amide group, a urethane group, a urea group, an ester group, a hydroxy group, or a carboxyl group. good.

  The epoxy group-free alkoxysilane is preferably a tetraalkoxysilane or trialkoxysilane, or a mixture thereof. It is preferably a mixture of tetraalkoxysilane or trialkoxysilane, and contains a mixture of tetraalkoxysilane and trialkoxysilane, so that when a hard coat layer is formed, while having appropriate flexibility, Sufficient hardness can be obtained.

  When the epoxy group-free alkoxysilane is a mixture of tetraalkoxysilane and trialkoxysilane, the molar ratio of tetraalkoxysilane and trialkoxysilane is preferably 25:75 to 85:15, and 30:70 to 80:20 is more preferable, and 30:70 to 65:35 is even more preferable. By setting the molar ratio within the above range, it becomes easy to control the degree of polymerization of the alkoxysilane within a desired range and to control the hydrolysis rate and the solubility of the aluminum chelate.

  Tetraalkoxysilane is a tetrafunctional alkoxysilane, more preferably having 1 to 4 carbon atoms in each alkoxy group. Of these, tetramethoxysilane and tetraethoxysilane are particularly preferably used. By setting the number of carbon atoms to 4 or less, the hydrolysis rate of tetraalkoxysilane when mixed with acidic water does not become too slow, and the time required for dissolution until a uniform aqueous solution is shortened. Thereby, the manufacturing efficiency at the time of manufacturing a hard-coat layer can be improved. Examples of commercially available products include KBE-04 (manufactured by Shin-Etsu Chemical Co., Ltd.).

The trialkoxysilane is a trifunctional alkoxysilane represented by the following general formula (1).
RSi (OR ¹ ) ₃ (1)
Here, R is an organic group having 1 to 15 carbon atoms that does not contain an amino group, and R ¹ is an alkyl group having 4 or less carbon atoms such as methyl and ethyl groups.

  The trifunctional alkoxysilane represented by the general formula (1) does not contain an amino group as a functional group. That is, this trifunctional alkoxysilane has an organic group R having no amino group. When R has an amino group, if it is mixed with a tetrafunctional alkoxysilane and hydrolyzed, dehydration condensation is promoted between the produced silanols. For this reason, an aqueous composition becomes unstable and is not preferable.

  R in the general formula (1) may be an organic group having a molecular chain length that has 1 to 15 carbon atoms. By setting the number of carbon atoms to 15 or less, the flexibility when the hard coat layer is formed is not excessively increased, and sufficient hardness can be obtained. By setting the carbon number of R within the above range, a hard coat layer with improved brittleness can be obtained. Moreover, the adhesiveness of other films, such as a support body, and a hard-coat layer can be improved.

  Furthermore, the organic group represented by R may have a heteroatom such as oxygen, nitrogen, or sulfur. When the organic group has a hetero atom, adhesion with other films can be further improved.

  As trialkoxysilane, vinyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-chloropropyltrimethoxysilane, 3-ureidopropyltrimethoxysilane, propyltrimethoxysilane, Phenyltrimethoxysilane, vinyltriethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltriethoxysilane, 3-chloropropyltriethoxysilane, 3-ureidopropyltriethoxysilane, methyltriethoxysilane, methyl Trimethoxysilane, ethyltriethoxysilane, ethyltrimethoxysilane, propyltriethoxysilane, propyltrimethoxysilane, phenyltriethoxysilane, phenol It can be exemplified Le trimethoxysilane. Of these, methyltriethoxysilane and methyltrimethoxysilane are particularly preferably used. Examples of commercially available products include KBE-13 (manufactured by Shin-Etsu Chemical Co., Ltd.).

<Metal complex>
The hard coat layer used in the present invention may contain a metal complex as a curing agent. As the metal complex, a metal complex composed of Al, Mg, Mn, Ti, Cu, Co, Zn, Hf and Zr is preferable, and these can be used in combination.

  These metal complexes can be easily obtained by reacting a metal alkoxide with a chelating agent. Examples of chelating agents include β-diketones such as acetylacetone, benzoylacetone and dibenzoylmethane, β-keto acid esters such as ethyl acetoacetate and ethyl benzoylacetate.

  Preferable specific examples of the metal complex include ethyl acetoacetate aluminum diisopropylate, aluminum tris (ethyl acetoacetate), alkyl acetoacetate aluminum diisopropylate, aluminum monoacetyl acetate bis (ethyl acetoacetate), aluminum tris (acetyl) Magnesium chelate compounds such as ethyl acetoacetate magnesium monoisopropylate, magnesium bis (ethylacetoacetate), alkyl acetoacetate magnesium monoisopropylate, magnesium bis (acetylacetonate), zirconium tetraacetylacetate Narate, zirconium tributoxyacetylacetonate, zirconium acetate Le acetonate bis (ethyl acetoacetate), manganese acetylacetonate, cobalt acetylacetonate, copper acetylacetonate, titanium acetylacetonate and titanium oxy acetylacetonate. Of these, aluminum tris (acetylacetonate), aluminum tris (ethylacetoacetate), magnesium bis (acetylacetonate), magnesium bis (ethylacetoacetate), and zirconium tetraacetylacetonate are preferred, and storage stability Considering availability, aluminum tris (acetylacetonate) and aluminum tris (ethylacetoacetate), which are aluminum chelate complexes, are particularly preferable. Examples of commercially available products include aluminum chelate A (W), aluminum chelate D, aluminum chelate M (manufactured by Kawaken Fine Chemical Co., Ltd.), and the like.

The proportion of the metal complex is preferably 17 to 70 mol% with respect to the epoxy group-containing alkoxysilane. The proportion occupied by the metal complex may be 17% or more, and more preferably 20% or more. Moreover, the content rate of a metal complex should just be 70% or less, it is preferable that it is 65% or less, and it is more preferable that it is 60% or less.
In the present invention, when the metal complex is contained in the above lower limit or more, excellent alkali resistance can be obtained when the hard coat layer is formed. Moreover, by setting it as the said upper limit or less, the dispersibility in aqueous solution can be made favorable, and manufacturing cost can be suppressed.

<Inorganic fine particles>
The hard coat layer used in the present invention may contain inorganic fine particles. The inorganic fine particles are added for the purpose of adjusting the refractive index of the hard coat layer to a preferable range and for increasing the alkali resistance of the hard coat layer.
A preferable example of the inorganic fine particles is a transparent and insulating metal oxide. For example, it is preferable to use fine particles composed of silica, alumina, zirconia, and titanium. In particular, it is preferable to use fine silica particles from the viewpoint of crosslinking with alkoxysilane.

As the silica fine particles, dry powdery silica produced by combustion of silicon tetrachloride can be used, but colloidal silica in which silicon dioxide or a hydrate thereof is dispersed in water is more preferable. Specific examples include, but are not limited to, Snowtex series manufactured by Nissan Chemical Industries, Ltd. such as Snowtex O-33. The average particle diameter of colloidal silica is 3 nm to 50 nm, preferably 4 nm to 50 nm, more preferably 4 nm to 40 nm, and particularly preferably 5 nm to 35 nm.
Here, the average particle diameter can be determined from a photograph obtained by observing dispersed inorganic fine particles with a transmission electron microscope. The projected area of the particles is obtained, and the equivalent circle diameter is obtained therefrom, which is taken as the average particle size (average primary particle size). The average particle diameter of the inorganic fine particles can be calculated by measuring the projected area of 300 or more particles and obtaining the equivalent circle diameter.

  In addition, as for colloidal silica, it is more preferable that pH at the time of adding in an aqueous composition is adjusted to the range of 2-7. When this pH is 2 to 7, the stability of silanol, which is a hydrolyzate of alkoxysilane, is better than when it is less than 2 or greater than 7, and the dehydration condensation reaction of this silanol proceeds faster. It is possible to suppress an increase in the viscosity of the coating liquid due to this.

  When inorganic fine particles are contained, 0 <x ≦ 80, where x is the ratio (unit: mass%) of the inorganic fine particles to the total solid content contained in the aqueous composition. x is preferably 1 or more, and more preferably 3 or more. Moreover, x should just be 80 or less, it is preferable that it is 70 or less, and it is more preferable that it is 65 or less. By setting the proportion of the inorganic fine particles in the aqueous composition within the above range, higher alkali resistance can be obtained when the hard coat layer is formed.

  The ratio (unit: mass%) of the epoxy group-containing alkoxysilane to the total alkoxysilane is x, where x is the ratio (unit: mass%) of the inorganic fine particles to the total solid content in the aqueous composition. When y, it is preferable that y ≧ x−5. Furthermore, it is more preferable that y ≧ x. By setting the relationship between y and x in the above range, higher alkali resistance can be obtained, and a change in haze value when immersed in an alkaline solution can be suppressed. Furthermore, the stability of the aqueous composition can be increased.

<Other additives>
Furthermore, a surfactant, a slipping agent, and a matting agent may be added to the hard coat layer for the purpose of reducing friction on the coating film surface or further improving the coating property.
Further, the hard coat layer may be colored by dispersing pigments, dyes, and other fine particles. Furthermore, for the purpose of improving the weather resistance, an ultraviolet absorber, an antioxidant or the like may be added.

  As the surfactant, various surfactants such as a fluorine-based surfactant, a nonionic surfactant, a cationic surfactant, an anionic surfactant, and a silicone-based surfactant can be used.

  Examples of the fluorosurfactant include Megafac F171, F172, F173, F176, F176, F177, F141, F142, F143, F144, R30, F437, F475, F479, F482, F554, F780, F780, F781 (above DIC Corporation), Florard FC430, FC431, FC171 (above, Sumitomo 3M Limited), Surflon S-382, SC-101, Same SC-103, Same SC-104, Same SC-105, Same SC1068, Same SC-381, Same SC-383, Same S393, Same KH-40 (manufactured by Asahi Glass Co., Ltd.), PF636, PF656, PF6320 PF6520, PF7002 (manufactured by OMNOVA), and the like.

  Specific examples of nonionic surfactants include glycerol, trimethylolpropane, trimethylolethane, and ethoxylates and propoxylates thereof (for example, glycerol propoxylate, glycerin ethoxylate, etc.), polyoxyethylene lauryl ether, polyoxyethylene Stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene nonylphenyl ether, polyethylene glycol dilaurate, polyethylene glycol distearate, sorbitan fatty acid ester (Pluronic L10, L31, L61, L62 manufactured by BASF, 10R5, 17R2, 25R2, Tetronic 304, 701, 704, 901, 904, 150R1, Pi Nin D-6512, D-6414, D-6112, D-6115, D-6120, D-6131, D-6108-W, D-6112-W, D-6115-W, D-6115-X, D -6120-X (manufactured by Takemoto Yushi Co., Ltd.), Solsperse 20000 (manufactured by Nippon Lubrizol Co., Ltd.), NAROACTY CL-95, HN-100 (manufactured by Sanyo Chemical Industries, Ltd.) and the like.

  Specific examples of the cationic surfactant include phthalocyanine derivatives (trade name: EFKA-745, manufactured by Morishita Sangyo Co., Ltd.), organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.), (meth) acrylic acid ( Co) polymer polyflow no. 75, no. 90, no. 95 (manufactured by Kyoeisha Chemical Co., Ltd.), W001 (manufactured by Yusho Co., Ltd.) and the like.

  Specific examples of the anionic surfactant include W004, W005, W017 (manufactured by Yusho Co., Ltd.), sanded BL (manufactured by Sanyo Chemical Industries, Ltd.), and the like.

Examples of the silicone surfactant include “Toray Silicone DC3PA”, “Toray Silicone SH7PA”, “Toray Silicone DC11PA”, “Tore Silicone SH21PA”, “Tore Silicone SH28PA”, “Toray Silicone” manufactured by Toray Dow Corning Co., Ltd. “Silicone SH29PA”, “Toresilicone SH30PA”, “Toresilicone SH8400”, “TSF-4440”, “TSF-4300”, “TSF-4445”, “TSF-4460”, “TSF” manufactured by Momentive Performance Materials, Inc. -4552 "," KP341 "," KF6001 "," KF6002 "manufactured by Shin-Etsu Silicone Co., Ltd.," BYK307 "," BYK323 "," BYK330 "manufactured by Big Chemie.
Only one type of surfactant may be used, or two or more types may be combined.
The addition amount of the surfactant is preferably 0.001% by mass to 2.0% by mass, and more preferably 0.005% by mass to 1.0% by mass with respect to the total mass of the hard coat layer.

  As the slip agent, an aliphatic wax can be contained. Specific examples of the aliphatic wax include plant systems such as carbana wax, candelilla wax, rice wax, wood wax, jojoba oil, palm wax, rosin-modified wax, auricule wax, sugar cane wax, esparto wax, bark wax, etc. Animal waxes such as wax, beeswax, lanolin, whale wax, ibota wax, shellac wax, mineral waxes such as montan wax, ozokerite, ceresin wax, petroleum waxes such as paraffin wax, microcrystalline wax, petrolactam, fishertro push Examples thereof include synthetic hydrocarbon waxes such as wax, polyethylene wax, oxidized polyethylene wax, polypropylene wax, and oxidized polypropylene wax. Among these, carbana wax, paraffin wax, and polyethylene wax are particularly preferable because of easy adhesion to a hard coat layer and a pressure-sensitive adhesive and good lubricity. These are also preferably used as aqueous dispersions because they can reduce the environmental burden and are easy to handle. Examples of commercially available products include Cellosol 524 (manufactured by Chukyo Yushi Co., Ltd.).

As the matting agent, either organic or inorganic fine particles can be used. For example, polymer fine particles such as polystyrene, polymethyl methacrylate, silicone resin, and benzoguanamine resin, and inorganic fine particles such as silica, calcium carbonate, magnesium oxide, and magnesium carbonate can be used. Among these, polystyrene, polymethylmethacrylate, and silica are preferably used from the viewpoint of improving the slipperiness and cost.
These particles may be used alone or as a colloid dispersed in a dispersion medium such as water, such as colloidal silica. Examples of commercially available products include Snowtex XL (manufactured by Nissan Chemical Industries, Ltd.), Seahoster KE-P250 (manufactured by Nippon Shokubai Co., Ltd.), and the like. Two or more kinds of matting agents may be included.

(Transparent conductive film / touch panel)
By laminating a transparent electrode layer on the laminated film of the present invention, a transparent conductive film or a touch panel can be obtained. In addition, the transparent conductive film or the touch panel may be provided with other layers such as an optical adjustment layer, a gas barrier layer, a transparent electrode layer such as an ITO electrode, a prism layer, and an antireflection layer as necessary.

In general, ITO (indium tin oxide) is used for the transparent electrode layer, and the electrode pattern is produced by patterning an ITO conductive film. The hard coat layer and the transparent electrode layer may be laminated so as to be in contact with each other, or an adjustment layer such as an optical adjustment layer may be laminated between the hard coat layer and the transparent electrode. The optical adjustment layer is provided to adjust the difference in refractive index between the layers.
The refractive index of ITO is about 2.1, which is larger than the refractive index of 1.6 of the polyester film that is the support substrate. Therefore, since the reflection intensity due to external light is different between the place where ITO is present and the place where ITO is not present, the ITO pattern can be seen and display quality is remarkably deteriorated. This phenomenon is called ITO bone appearance. However, by providing the optical adjustment layer, the difference in refractive index with the transparent electrode layer can be adjusted, and the ITO bone appearance can be reduced.
As a manufacturing method of the optical adjustment layer, any film forming method may be used as long as the film thickness can be controlled. For example, a method described in JP 2012-206307 A can be used. As a manufacturing method of the optical adjustment layer, any film forming method may be used as long as the film thickness can be controlled. For example, a method described in JP 2012-206307 A can be used.

As a transparent electrode layer that can be used for the transparent conductive film or touch panel of the present invention, any one of indium oxide, zinc oxide, tin oxide, or two or three kinds of mixed oxides thereof, and other additions Although the thing etc. to which the thing was added are mentioned, A various material can be used by the objective and the application, and it does not specifically limit. At present, the most reliable and proven material is indium tin oxide (ITO).
As a method for producing the transparent electrode layer, any film forming method can be used as long as the film thickness can be controlled. For example, a method described in JP 2012-206307 A can be used.

The touch panel of the present invention can be used as an input device by being incorporated in a display device such as a liquid crystal display, a plasma display, an organic EL display, a CRT display, and electronic paper. By using the touch panel of the present invention, occurrence of interference unevenness can be suppressed and a touch panel with good color can be obtained.
There are two types of touch panel configurations, such as a resistance film type and a capacitance type. Capacitance type input devices have the advantage of simply forming a light-transmitting conductive film on a single substrate. A capacitance type is preferred. In such a capacitance-type input device, for example, electrode patterns are extended in a direction intersecting each other as transparent electrode layers, and when a finger or the like touches, it is detected that the capacitance between the electrodes changes. A type that detects the input position can be preferably used. With respect to the configuration of such a touch panel, for example, descriptions in JP 2010-86684 A, JP 2010-152809 A, JP 2010-257492 A, and the like can be referred to.
Regarding the configuration of an image display device equipped with a touch panel as a component, “Latest Touch Panel Technology” (published July 6, 2009, Techno Times), supervised by Yuji Mitani, “Technology and Development of Touch Panels”, CM Publishing (2004, 12), FPD International 2009 Forum T-11 lecture textbook, Cypress Semiconductor Corporation application note AN2292, and the like can be applied.
In addition, regarding the configuration of a liquid crystal display in which a touch panel can be incorporated, descriptions in JP-A-2002-48913 can be referred to.

(Laminated film manufacturing method)
The laminated film is obtained by forming a polymer layer on a polyester film subjected to glow discharge treatment, and further forming a hard coat layer on the polymer layer.
Specifically, the method for producing a laminated film includes a step of performing a glow discharge treatment on the surface of a polyester film heated to Tg or higher, and a polymer layer containing particles on the surface of the polyester film subjected to the glow discharge treatment. And a step of forming a hard coat layer containing an alkoxysilane hydrolysis condensate on the polymer layer.

<Production method of polyester film>
The polyester film used in the present invention can be produced using various known methods such as a solution casting method and a melt extrusion method. A commercially available polyester film can also be used.

The surface of the obtained polyester film is subjected to glow discharge treatment. The surface temperature of the polyester film during the glow discharge treatment is more preferably Tg to 200 ° C of the polyester film, and more preferably Tg to 180 ° C.
The glow discharge treatment step may be performed after the polyester film is stretched in a uniaxial direction, may be performed after biaxial stretching, or may be applied in a state where it is not stretched at all.

  For details of the heating of the polyester film, reference can be made to the corresponding description regarding the glow discharge treatment of the polyester film described above. Specific methods for raising the temperature of the film to be treated in vacuum include heating with an infrared heater, heating by contacting with a hot roll, and the like.

  The step of performing glow discharge treatment on the surface of the polyester film heated to Tg or higher is a step of generating glow discharge on the surface of the polyester film heated to Tg or higher. By performing glow discharge treatment on the surface of the polyester film heated to Tg or more, it is possible to prevent oligomers from being deposited on the polyester film and to prevent the polyester film from being whitened. Furthermore, yellowing of the polyester film can be suppressed.

The glow discharge treatment is preferably performed immediately after heating the polyester film. In the present invention, the glow discharge treatment is preferably performed when the surface temperature of the polyester film is Tg or higher. By performing the glow discharge treatment in a state where the surface of the polyester film is Tg or more, the adhesion between the polymer layer and the polyester film can be enhanced. Further, the amount of change in the b ^* value before and after the glow discharge treatment can be reduced, and the oligomer can be prevented from being precipitated from the polyester film. Therefore, the laminated film obtained in the present invention has high adhesion and transparency, and is suitably used for touch panels and the like.

<Method for producing polymer layer>
The step of forming a polymer layer in the present invention is a step of forming a polymer layer containing particles on the surface of the polyester film subjected to the glow discharge treatment. As a method for forming the polymer layer, there are a method of bonding a polymer sheet having easy adhesion to a polyester film and a method by coating, but the method by coating is simple and can be formed with a highly uniform thin film. It is preferable in a certain point. There is no restriction | limiting in particular as an application | coating method, Well-known methods, such as bar coater application | coating and slide coater application | coating, can be used.

  A solvent (coating solvent) can be used when the polymer layer is applied. As the coating solvent, water, toluene, methyl alcohol, isopropyl alcohol, methyl ethyl ketone and the like, and aqueous and organic solvent based coating solvents such as a mixed system thereof can be used. Among these, the method using water as a coating solvent is preferable in view of cost and ease of production. In these solvents, particles and a binder constituting the polymer layer can be mixed to obtain a coating solution for forming a polymer layer.

  The polymer layer is cured by applying a coating solution for forming a polymer layer in a layered manner on a polyester film and then drying it. When the polymer layer has a two-layer structure, it is preferable that the second layer is applied and then dried and cured.

The polyester film laminated with the polymer layer can be subjected to stretching treatment in the stretching step. In the stretching step, the laminated film is preferably stretched in the uniaxial direction or biaxial direction, and more preferably in the biaxial direction. Stretching in the biaxial direction (biaxial stretching) includes stretching in the longitudinal direction (MD: Machine Direction) (hereinafter also referred to as “longitudinal stretching”) and stretching in the width direction (TD: Transverse Direction) (hereinafter referred to as “lateral stretching”). It is also preferred that The longitudinal stretching and lateral stretching may each be performed once, or may be performed a plurality of times, and may be simultaneously performed longitudinally and laterally.
The stretching treatment is preferably performed at a glass temperature (Tg) ° C. to (Tg + 60) ° C. of the film, more preferably Tg + 3 ° C. to Tg + 40 ° C., and further preferably Tg + 5 ° C. to Tg + 30 ° C.

In the stretching step, the film can be heat-treated before or after the stretching treatment, preferably after the stretching treatment. By performing heat treatment, microcrystals can be generated, and mechanical properties and durability can be improved. About 180 ° C to 210 ° C (more preferably 185 ° C
The film may be subjected to a heat treatment for 1 second to 60 seconds (more preferably 2 seconds to 30 seconds) at ˜210 ° C.

  In the stretching step, a thermal relaxation treatment can be performed after the heat treatment. The thermal relaxation treatment is a treatment for shrinking the film by applying heat to the film for stress relaxation. The thermal relaxation treatment is preferably performed in both the MD and TD directions of the film. The various conditions in the thermal relaxation treatment are preferably a treatment at a temperature lower than the heat treatment temperature, and preferably 130 to 205 ° C. In the thermal relaxation treatment, the thermal shrinkage rate (150 ° C.) of the film is preferably 1 to 12% for both MD and TD, and more preferably 1 to 10%.

<Method for producing hard coat layer>
The step of forming the hard coat layer is a step of laminating the hard coat layer on the surface of the polymer layer opposite to the surface on which the polyester film is laminated. A hard-coat layer and a polyester film are arrange | positioned so that it may oppose through a polymer layer. The step of forming the hard coat layer may include a step of hydrolyzing the alkoxysilane and a step of condensing the hydrolyzed alkoxysilane.
A hard-coat layer is formed by apply | coating the aqueous composition which added the alkoxysilane to the surface of the polymer layer to the aqueous composition of this invention. The preparation procedure of the aqueous composition is not particularly limited, but the method of hydrolyzing the alkoxysilane and adding the colloidal silica dispersion and the aluminum chelate complex to the hydrolyzed solution in this order has the highest solubility and storage stability.

Before the aqueous composition is applied, it is preferable to add a pH adjusting agent to the aqueous composition to adjust the pH to a desired range. The pH adjuster is not particularly limited as long as it changes the pH. Specifically, as the acid (organic acid, inorganic acid), for example, nitric acid, oxalic acid, acetic acid, formic acid, hydrochloric acid, etc., as alkali Examples thereof include ammonia, triethylamine, ethylenediamine, sodium hydroxide, potassium hydroxide and the like. The pH adjusting agent may be added directly or as a solution such as an aqueous solution. The amount of the pH adjuster to be used is not particularly limited as long as the pH satisfies a desired range.
In this invention, it is preferable to adjust so that pH of an aqueous composition may be 2-6. As the pH adjuster, nitric acid, oxalic acid, acetic acid, formic acid, and hydrochloric acid are preferable, and acetic acid is particularly preferable.

Although the application | coating process of an aqueous composition may be provided in the middle of the extending process of the polyester film which laminated | stacked the polymer layer, it is preferable to be provided after an extending process. A known applicator can be used as appropriate for application of the aqueous composition. For example, a spin coater, a roll coater, a bar coater, a curtain coater, etc. can be mentioned.
A step of drying the coating solution is provided after the coating step. In the drying step, it is preferable to perform heat drying. In heat drying, it is preferable to heat so that the temperature of the coating film is 160 ° C. or higher, more preferably 170 ° C. or higher, and more preferably 180 ° C. or higher. Further, the temperature of the coating film is preferably 220 ° C. or lower, and more preferably 210 ° C. or lower. By setting the heating and drying temperature within the above range, the coating film can be sufficiently cured, and deformation of the hard coat layer can be prevented. The heating time is preferably 10 seconds to 5 minutes.

  The laminated film obtained after the drying step may then be wound into a roll or cut into a sheet.

  The features of the present invention will be described more specifically with reference to examples and comparative examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below.

Example 1
<Creation of polyester film>
Polyethylene terephthalate (hereinafter referred to as PET) resin having an intrinsic viscosity of 0.64 (dl / g) obtained by polycondensation using a Ti compound as a catalyst and a Tg temperature of 69 ° C. is dried to a moisture content of 50 ppm or less, and the heater temperature is 280 It was set to ˜300 ° C. and melted in an extruder. The melted PET resin was discharged from a die part onto a chill roll electrostatically applied to obtain an amorphous base. The obtained amorphous base was stretched 3.3 times in the base traveling direction, and then stretched 3.8 times in the width direction to obtain a PET film having a thickness of 125 μm. The refractive index was 1.66.

While the PET film formed as described above was conveyed at a conveyance speed of 80 m / min, glow discharge treatment was performed on both surfaces under vacuum conditions. The conditions for the glow discharge treatment were 4.0 KJ / m ² , and the surface temperature of the PET film before the glow discharge treatment was 150 ° C.

<Creation of polymer layer>
The following formulation was used for the polymer layer coating solution.
Tin oxide fine particle dispersion 8 parts by mass (average particle size 60 nm) as solid content
2.8 parts by mass of polyurethane (manufactured by Mitsui Chemicals, Takelac WS-5100)
Cross-linking agent 4.2 parts by mass (manufactured by Nisshinbo Chemical Co., Ltd., 10% dilution of Carbodilite V-02-L2)
Surfactant A 0.2 parts by mass (manufactured by Sanyo Chemical Industries, Ltd., 10% aqueous solution of sanded BL, anionic)
Surfactant B 0.2 parts by mass (manufactured by Sanyo Chemical Industries, Ltd., 10% diluted solution of NAROACTY CL-95, nonionic)
84.6 parts by weight of water

  The above formulation is adjusted so that the refractive index of the polymer layer after coating and drying is 1.58. A polymer layer coating solution was applied to the surface of the PET film subjected to the glow discharge treatment by a bar coating method. And this was dried at 150 degreeC for 2 minutes. A laminated film having a polymer layer coated on both sides of a PET film was obtained. The film thickness of the polymer layer was measured by observing the laminated film at a magnification of 200000 times using a transmission electron microscope (JEM2010 (manufactured by JEOL Ltd.)). The film thickness was 100 nm.

<Creation of hard coat film>
The polymer layer obtained as described above was subjected to corona treatment, and then an aqueous composition for forming a hard coat layer was applied. And this was dried at 150 degreeC for 2 minutes, and the hard-coat layer was formed. The film thickness of the hard coat layer was 1 μm.

The following formulation was used for the aqueous composition.
Acetic acid aqueous solution 100 parts by mass (manufactured by Daicel Chemical Industries, Ltd., 1% aqueous solution of industrial acetic acid)
80 parts by mass of 3-glycidoxypropyltriethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBE-403)
20 parts by mass of tetraethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBE-04)
Aluminum chelate complex 22.1 parts by mass (made by Kawaken Fine Chemicals, aluminum chelate D)
200 parts by weight of inorganic fine particles (manufactured by Nissan Chemical Industries, Snowtex O-33)
Surfactant A 0.2 parts by mass (manufactured by Sanyo Chemical Industries, Ltd., 10% aqueous solution of sanded BL, anionic)
Surfactant B 0.2 parts by mass (manufactured by Sanyo Chemical Industries, Ltd., 10% diluted solution of NAROACTY CL-95, nonionic)
Matting agent 0.02 part by mass (manufactured by Nippon Shokubai Co., Ltd., Seahoster KE-P250)

  The preparation was performed according to the following procedure. After 3-glycidoxypropyltriethoxysilane (KBE-403) was added to 100 parts by mass of 1% acetic acid and sufficiently hydrolyzed, tetraalkoxysilane (KBE-04) was added. A necessary part by mass of the aluminum chelate complex with respect to the epoxy group-containing alkoxysilane was added, and inorganic fine particles (Snowtex O-33) were added thereto. Add 0.2 parts by mass of 10% dilution of surfactant A (Sandet BL) and 10% dilution of surfactant B (Naroacty CL-95), and add matting agent (Seahoster KE-P250). And water was added so that solid content concentration might be 15%, and it was set as the aqueous composition.

  A laminated film was obtained as described above.

(Example 2)
A laminated film was prepared in the same manner as in Example 1 except that the average particle size of the particles contained in the polymer layer was 130 nm (manufactured by Mitsubishi Materials Electronics Chemical Co., Ltd., EP SPDL-2).

(Example 3)
A laminated film was prepared in the same manner as in Example 1 except that the average particle size of the particles contained in the polymer layer was 40 nm.

Example 4
A laminated film was prepared in the same manner as in Example 1 except that the amounts of 3-glycidoxypropyltriethoxysilane and tetraethoxysilane contained in the hard coat layer were changed as shown in Table 1.

(Example 5)
A laminated film was prepared in the same manner as in Example 1 except that the particles contained in the polymer layer were changed to zirconium oxide having an average particle diameter of 55 nm (manufactured by Nissan Chemical Industries, Ltd., ZR-30BS).

(Example 6)
A laminated film was prepared in the same manner as in Example 1 except that the surface temperature of the PET film before the glow discharge treatment was changed to 110 ° C.

(Examples 7 and 8)
Each condition of glow discharge treatment, except that the ^{7.0KJ / m 2, 30KJ / m} 2 was prepared a laminate film in the same manner as in Example 1.

(Comparative Example 1)
A laminated film was prepared in the same manner as in Example 1 except that the temperature at which the glow discharge treatment was performed on the surface of the polyester film was room temperature (25 ° C.).

(Comparative Example 2)
A laminated film was produced in the same manner as in Example 1 except that the surface treatment of the polyester film was a corona treatment.

(Comparative Example 3)
A laminated film was prepared in the same manner as in Comparative Example 2 except that the average particle size of the particles contained in the polymer layer was 130 nm.

(Comparative Example 4)
A laminated film was prepared in the same manner as in Comparative Example 2 except that the polymer layer did not contain particles.

(Evaluation)
The laminated films obtained in Examples 1 to 8 and Comparative Examples 1 to 4 were evaluated using the following method.

<Adhesion evaluation test (normal conditions)>
Using a single-blade razor on the surface of the sample, eleven scratches were made in the vertical and horizontal directions to form 100 squares. Next, a cellophane tape (No. 405 manufactured by Nichiban Co., Ltd., 24 mm width) is applied on this, and then completely adhered by rubbing with poppy rubber from above, and then peeled off in the direction of 90 ° to peel off the peeled-off mesh By determining the number, the following ranking was performed to evaluate the adhesion. The width of the scratch was 1 mm both vertically and horizontally.
Rank A: No peeling B rank: When the number of peeled squares is less than 5 Rank C: When the number of peeled squares is 5 or more and less than 10 D Rank: When the number of peeled squares is 10 or more and less than 30, Rank E : When the number of peeled cells is 30 or more

<Adhesion evaluation test (mandatory conditions)>
Evaluation of adhesion after wet heat aging was performed as follows.
Each polymer sheet was held for 500 hours under an environmental condition of 65 ° C. and a relative humidity of 95%, and then conditioned for 1 hour in an environment of 25 ° C. and a relative humidity of 60%, and then the same method as the evaluation of adhesion described above The adhesion was evaluated.
Rank A: No peeling B rank: When the number of peeled squares is less than 5 Rank C: When the number of peeled squares is 5 or more and less than 10 D Rank: When the number of peeled squares is 10 or more and less than 30, Rank E : When the number of peeled cells is 30 or more

<Evaluation of b ^* value>
The b ^* value was measured by a transmission method using a spectral color difference meter (SE-2000, Nippon Denshoku Industries Co., Ltd.).
A rank: 0 to 1.0
B rank: 1.0-1.2
C rank: 1.2 ~

<Evaluation of transparency>
Transparency was evaluated by measuring the total light transmittance and the amount of change in haze before and after heat treatment, and evaluating this result. The total light transmittance and haze were measured according to JIS-K-7105 using a haze meter (NDH-2000, Nippon Denshoku Industries Co., Ltd.).
For the amount of change in haze before and after heat treatment (unit:%), measure the haze before and after the heat treatment under the specified conditions (that is, without heat treatment) and after the heat treatment. When the haze after H1 and heat treatment was set to H2, it calculated | required by the type | formula of | H2-H1 | / H1 * 100.
The heat treatment in the haze measurement was performed by placing a sample sampled from the conductive film 10 in an oven set at an internal temperature of 150 ° C. and holding for 10 minutes. In addition, the haze measurement after heat processing was implemented after cooling the sample taken out from oven.
Rank A: 0.5% or less Rank B: 0.5-1%
C rank: 1% or more

<Evaluation of interference unevenness>
The sample coated with the hard coat layer was irradiated on the coated layer with diffused light from a fluorescent lamp through a milky white acrylic plate from a desk on which a black doskin cloth was attached, and the reflected light generated was visually observed. And the rainbow-shaped interference nonuniformity observed at this time was judged by the following reference | standard, and this was evaluated as a coating surface shape. Moreover, in visual judgment, the blackening process was performed with respect to the sample as forced condition evaluation, and it adjusted so that the transmittance | permeability of 500 nm light might be set to 1% or less. As blackening treatment, magic ink (artline oil-based marker supplement ink KR-20 black, manufactured by shachihata Co., Ltd.) was applied to the surface of the sample opposite to the surface to be observed, and then dried. .
Rank A: Iridescent interference unevenness is not visually confirmed in both the sample after blackening and the untreated sample.
Rank B: Irregular interference unevenness is visually confirmed in the sample after the blackening treatment, but is not confirmed in the untreated sample.
Rank C: Rainbow-like interference unevenness is visually confirmed in both the blackened sample and the untreated sample.

<Non-crystallinity / crystallinity>
The peak ratio was measured and calculated by the ATR-IR method.

<Surface modification depth>
The modified depth from the surface was evaluated by a cross-sectional TEM.

  Table 1 summarizes the evaluation results of the respective items of the laminated films obtained in Examples 1 to 8 and Comparative Examples 1 to 4.

The laminated films obtained in Examples 1 to 8 contain particles in the polymer layer, and have a surface modification with an amorphousness (non-crystallinity / crystallinity) of 5% or more within the range of 40 to 330 nm from the surface of the polyester film. Since it has a quality layer, it has excellent adhesion under normal conditions and forced conditions, and interference unevenness is eliminated. In particular, in Examples 1 and 3 to 8, since the particle diameter of the particles is below a certain value, both the b ^* value and the haze value are kept low, and it can be seen that the color and transparency are good.
On the other hand, in Comparative Example 1, since the glow discharge treatment is not performed at Tg or higher, a predetermined surface modification layer is not formed, and it can be seen that the adhesion under normal conditions and forced conditions is extremely poor. Further, in Comparative Example 2, since the glow discharge treatment is not performed, a predetermined surface modification layer is not formed, and it can be seen that the adhesion under normal conditions and forced conditions is extremely poor. In Comparative Example 3, although glow discharge treatment is not performed, particles having a relatively large particle size are used, and therefore, adhesion under normal conditions is exhibited to some extent. However, the adhesion under forced conditions is reduced. Since Comparative Example 4 does not contain particles, the adhesion is not lowered, but it is understood that the interference unevenness is not eliminated.

  According to the present invention, in a laminated film having a hard coat layer, the occurrence of interference unevenness can be suppressed and the adhesion between the layers of the laminated film can be enhanced. Moreover, since the interference unevenness is eliminated and the adhesion between layers is good, the laminated film of the present invention is suitable for applications such as a transparent conductive film and a touch panel, and has high industrial applicability.

DESCRIPTION OF SYMBOLS 1 Polyester film 2 Polymer layer 3 Particle | grains 4 Hard-coat layer 5 Surface modification layer 10 Laminated | multilayer film

Claims (17)

A laminated film in which a polyester film, a polymer layer, and a hard coat layer are laminated in order,
The polyester film has a surface modification layer having an amorphous degree (non-crystallinity / crystallinity) of 5% or more on the surface side on which the polymer layers are laminated, and the surface modification layer is a surface of the polyester film. To any depth within the range of 40 to 330 nm,
The polymer layer comprises particles;
The hard coat layer is a laminated film containing a hydrolyzed condensate of alkoxysilane.   The laminated film according to claim 1, wherein the thickness of the polymer layer is 200 nm or less, and the average particle size of the particles is 0.65 times or less of the thickness of the polymer layer.   The laminated film according to claim 1 or 2, wherein the particles have an average particle diameter of 5 to 130 nm or less.   The laminated film according to any one of claims 1 to 3, wherein the particle has a refractive index of 1.60 to 3.00.   The laminated film according to claim 1, wherein the particles are metal oxide particles.   The laminated film according to any one of claims 1 to 5, wherein the particles are tin oxide or zirconium oxide.   The laminated film according to any one of claims 1 to 6, wherein the particles are contained in an amount of 40 to 80 mass% with respect to a solid content contained in the polymer layer.   The laminated film according to any one of claims 1 to 7, wherein the hydrolysis condensate of alkoxysilane is a hydrolysis condensate of an epoxy group-containing alkoxysilane and an epoxy group-free alkoxysilane. The laminated film according to claim 1, wherein the laminated film has a b ^* value of −2.0 to 2.0.
(Here, the b ^* value represents the b ^* value in the CIE 1976 L ^* a ^* b ^* color system.)   The haze of the said laminated | multilayer film is 2% or less, The laminated | multilayer film of any one of Claims 1-9.   The refractive index of the said polyester film is 1.60-1.75, The laminated | multilayer film of any one of Claims 1-10 characterized by the above-mentioned.   The refractive index of the said polymer layer is 1.52-1.69, The laminated | multilayer film of any one of Claims 1-11 characterized by the above-mentioned. Performing a glow discharge treatment on the surface of the polyester film heated to Tg or higher;
Forming a polymer layer containing particles on the surface of the polyester film subjected to glow discharge treatment;
A method for producing a laminated film, comprising a step of forming a hard coat layer containing a hydrolysis condensate of alkoxysilane on the polymer layer.   The method for producing a laminated film according to claim 13, wherein the step of forming the hard coat layer includes a step of hydrolyzing the alkoxysilane and a step of condensing the hydrolyzed alkoxysilane.   A laminated film produced by the production method according to claim 13 or 14.   The transparent conductive film which has a laminated | multilayer film of any one of Claims 1-12 and Claim 15.   The touch panel which has a laminated | multilayer film of any one of Claims 1-12 and Claim 15.