JP6130718B2 - Method for evaluating patterning step of light-transmitting conductive film - Google Patents

Description

  The present invention relates to a method for evaluating a patterning step of a light transmissive conductive film.

  As a conductive film mounted on a touch panel, there are many light transmissive conductive films obtained by laminating a light transmissive conductive layer made of indium tin oxide (ITO) or the like on a light transmissive support layer made of plastic. It is used.

  These light-transmitting conductive films are usually mounted on a touch panel after further patterning the light-transmitting conductive layer by further etching. In the light-transmitting conductive film in which the light-transmitting conductive layer is patterned in this way, the pattern of the light-transmitting conductive layer can be visually recognized on the film surface (so-called bone visibility phenomenon). Are known. The light-transmitting conductive film in which the light-transmitting conductive layer is patterned in this manner has a region where the light-transmitting conductive layer is present (in this specification, sometimes referred to as “pattern portion”), light. Different spectral transmittances and spectral reflectances are shown in a region where there is no transmissive conductive layer (in the present specification, sometimes referred to as an “etching portion”). Such a difference between the spectral transmittance and the spectral reflectance is considered to be a cause of the bone appearance phenomenon.

  In recent years, it has been reported that the step of the pattern portion of the light-transmitting conductive film is increased by heat treatment, and as a result, the appearance is deteriorated (Patent Document 1). However, only a visual method has been reported as such a step evaluation method.

JP 2012-128629 A

  The inventors of the present invention have a transparent conductive film having a pattern part and an etching part as described above, and the cross-sectional shape of the pattern part is a convex arc shape, and the cross-sectional shape of the etching part is downward. Some of them have a convex arc shape, and in this case, it has been found that the degree of the bone appearance phenomenon tends to increase as the degree of roundness of these arc shapes increases.

  The main object of the present invention is to provide a method for detecting such an arc shape and further evaluating the roundness.

The inventors of the present invention have intensively studied to solve the above problems and have completed the present invention. The present invention solves the above-mentioned problems, and is as follows.
Item 1.
A light transmissive conductive film having a light transmissive conductive layer partially etched on at least one surface,
The surface is a method for evaluating a patterning step of a light transmissive conductive film having a striped pattern composed of a pattern portion having a light transmissive conductive layer and an etched portion, and the following steps (1) to ( 4) containing method:
(1) The light transmission is performed such that the longitudinal direction of the striped pattern is α ° (5 ° ≦ α ≦ 85 °) with respect to the x-axis direction, and the surface having the striped pattern faces the positive z-axis direction. A conductive conductive film is arranged on the xy plane, and a device for projecting a reference pattern on which at least one linear light-dark boundary appears, and a CCD camera are arranged on the yz plane so that the incident angle and the regular reflection angle are equal. The step of:
(2) projecting the reference pattern onto the surface of the light-transmitting conductive film;
(3) forming a fluctuation of the reflected image of the reference pattern and subjecting a video signal obtained by photographing with the CCD camera to image processing;
(4) In the image obtained by the image processing, when a saw-shaped light / dark boundary is observed, a cross section of a surface of the pattern portion corresponding to the light / dark boundary perpendicular to the longitudinal direction of the striped pattern A step of determining that the shape is an upwardly convex arc shape and that the cross-sectional shape of the etched portion corresponding to the light / dark boundary is a downwardly convex arc shape.
Item 2.
Item 2. The method according to Item 1, wherein, in the step (4), a step in the saw shape is calculated, and a curvature radius of each of the pattern portion and the etching portion having a circular cross section is obtained based on the value.
Item 3.
Item 3. The method according to Item 1 or 2, wherein α is 30 ° to 60 °.
Item 4.
further,
(5) including a step of obtaining, as a patterning step, a sum of an arc shape height of the pattern portion and an arc shape depth of the etching portion based on the radius of curvature obtained in the step (4). The method according to 2 or 3.
Item 5.
Item 5. A light-transmitting conductive film manufactured so that a patterning step measured by the method according to Item 4 is 0.3 µm or less.
Item 6.
Item 6. A touch panel comprising the light transmissive conductive film according to Item 5.
Item 7.
A light transmissive conductive film having a light transmissive conductive layer partially etched on at least one surface,
The surface has a striped pattern composed of a pattern portion having a light-transmitting conductive layer and an etched portion, and a cross-sectional shape of the surface of the pattern portion perpendicular to the longitudinal direction of the striped pattern is high. A convex arc shape, and the cross-sectional shape of the etched portion corresponding to the light-dark boundary is a downward convex arc shape,
A method for inspecting a patterning step of a light transmissive conductive film,
A method of determining that the patterning step is good when the patterning step obtained as the sum of the arcuate height of the pattern part and the arcuate depth of the etching part is 0.3 μm or less.
Item 8.
Item 8. The method according to Item 7, comprising the following steps (i) to (iv):
(I) The light transmission so that the longitudinal direction of the striped pattern is α ° (5 ° ≦ α ≦ 85 °) with respect to the x-axis direction, and the surface having the striped pattern faces the positive z-axis direction. A conductive conductive film is arranged on the xy plane, and a device for projecting a reference pattern on which at least one linear light-dark boundary appears, and a CCD camera are arranged on the yz plane so that the incident angle and the regular reflection angle are equal. The step of:
(Ii) projecting the reference pattern onto the surface of the light transmissive conductive film;
(Iii) forming a fluctuation of a reflected image of the reference pattern and subjecting a video signal obtained by photographing with the CCD camera to image processing;
(Iv) A step of calculating a step in the saw shape obtained by the image processing, and obtaining a radius of curvature of each of the pattern portion and the etching portion having a circular cross section based on the value.

  By using the present invention to evaluate a light-transmitting conductive film having a pattern portion and an etching portion, the cross-sectional shape of the pattern portion is an upwardly convex arc shape, and the cross-sectional shape of the etching portion is It can be confirmed whether or not it has a convex arc shape. Furthermore, the degree of roundness of these arc shapes can be evaluated. These evaluation results are useful for improving the bone appearance phenomenon in the light-transmitting conductive film.

It is drawing which shows arrangement | positioning of the coordinate system and observation system in the evaluation method of this invention. It is a photograph instead of a drawing showing an example of a measurement image. It is drawing which shows the measurement image in case a cross-sectional shape is a combination of a plane and a slope. It is drawing which shows the measurement image in case a cross-sectional shape is a combination of circular arc. It is sectional drawing which shows the transparent conductive film of this invention by which the transparent conductive layer is arrange | positioned adjacent to the single side | surface of a transparent support layer. It is sectional drawing which shows the light transmissive conductive film of this invention by which the light transmissive conductive layer is arrange | positioned adjacent to both surfaces of a light transmissive support layer. It is sectional drawing which shows the light-transmitting conductive film of this invention by which an undercoat layer and a light-transmitting conductive layer are arrange | positioned adjacent to each other in this order on the single side | surface of a light-transmitting support layer. It is sectional drawing which shows the light transmissive conductive film of this invention by which an undercoat layer and a light transmissive conductive layer are arrange | positioned adjacent to each other in this order on both surfaces of the light transmissive support layer. Sectional drawing which shows the light-transmitting conductive film of this invention by which a hard-coat layer, an undercoat layer, and a light-transmitting conductive layer (B) are arrange | positioned adjacent to each other in this order on the single side | surface of a light-transmitting support layer. It is. A hard coat layer, an undercoat layer, and a light transmissive conductive layer are arranged adjacent to each other in this order on one surface of the light transmissive support layer, and another hard coat layer is directly disposed on the other surface. It is sectional drawing which shows the transparent conductive film of this invention which is. It is sectional drawing which shows the light transmissive conductive film of this invention by which a hard-coat layer, an undercoat layer, and a light transmissive conductive layer are arrange | positioned adjacent to each other in this order on both surfaces of the light transmissive support layer.

1. 1. Method for Evaluating Patterning Step 1.1 Description of Light-Transmitting Conductive Film The present invention is a light-transmitting conductive film having a light-transmitting conductive layer partially etched on at least one surface, The surface is a method for evaluating a patterning step of a light-transmitting conductive film having a striped pattern including a pattern portion where a light-transmitting conductive layer is present and an etching portion.

1.1.1 Description of Light-Transparent Conductive Layer In the present invention, the light-transmissive conductive layer means a layer that conducts electricity and transmits visible light. Although it does not specifically limit as a light transmissive conductive layer, For example, what is normally used as a light transmissive conductive layer in the light transmissive conductive film for touch panels can be used.

  The material for the light transmissive conductive layer is not particularly limited, and examples thereof include indium oxide, zinc oxide, tin oxide, and titanium oxide. The light-transmitting conductive layer is preferably a light-transmitting conductive layer containing indium oxide doped with a dopant in terms of achieving both light transmittance and conductivity. The light transmissive conductive layer may be a light transmissive conductive layer made of indium oxide doped with a dopant. Although it does not specifically limit as a dopant, For example, a tin oxide, a zinc oxide, those mixtures, etc. are mentioned.

In the case where a material in which indium oxide is doped with tin oxide is used as the material for the light transmissive conductive layer, indium oxide (III) (In ₂ O ₃ ) is doped with tin oxide (IV) (SnO ₂ ) (tin− Doped indium oxide (ITO) is preferred. In this case, the addition amount of SnO ₂ is not particularly limited, and examples thereof include 1 to 15% by weight, preferably 2 to 10% by weight, and more preferably 3 to 8% by weight. In addition, a material in which another dopant is further added to indium tin oxide may be used as a material for the light-transmitting conductive layer so long as the total amount of dopant does not exceed the numerical range shown on the left. Although it does not specifically limit as another dopant in the left, For example, selenium etc. are mentioned.

  The light transmissive conductive layer may be composed of any one of the various materials described above, or may be composed of a plurality of types.

  The light-transmitting conductive layer is not particularly limited, but may be a crystalline body, an amorphous body, or a mixture thereof.

  The thickness of the light transmissive conductive layer is preferably 10 nm or more and 30 nm or less. If it is 10 nm or more, necessary conductivity is obtained, and if it is 30 nm or less, the bone appearance phenomenon is alleviated.

  The method for disposing the light transmissive conductive layer may be either wet or dry, and is not particularly limited. Specific examples of the method for disposing the light transmissive conductive layer include, for example, a sputtering method, a vacuum deposition method, an ion plating method, a CVD method, and a pulse laser deposition method.

1.1.2 Description of Pattern Unit and Etched Unit The patterning method is not particularly limited, and can be performed, for example, as follows. First, a resist (a protective film for protecting the layer from the etching solution) is applied to the region to be left on the light-transmitting conductive layer. The application means may be performed by screen printing depending on the type of the resist. If a photoresist is used, it is performed as follows. Apply the photoresist to the area you want to leave on the light-transmitting conductive layer using a spin coater or slit coater, etc., and partially irradiate light or an electron beam to change the solubility of the photoresist only in that area. Thereafter, the portion having relatively low solubility is removed (this is called development). In this way, the resist is present only in the region to be left on the light-transmitting conductive layer. Subsequently, an etching solution is allowed to act on the light-transmitting conductive layer to selectively dissolve a region of the light-transmitting conductive layer that is not protected by the resist, and finally, the dissolved matter is removed to thereby remove the pattern. Form.

  In the present invention, the light-transmitting conductive film to be evaluated may be subjected to heat treatment after patterning. The heat treatment is mainly performed for the purpose of crystallizing the light transmissive conductive layer. The heat treatment causes wavy undulations in the light-transmitting conductive film, which may cause the cross-sectional shape of the pattern portion to be convex upward and the cross-sectional shape of the etched portion to be convex downward. . According to the method of the present invention, the presence or absence of such an arc shape can be detected, and further, the degree of roundness in the arc shape can be evaluated.

  The striped pattern composed of the pattern portion and the etched portion is not particularly limited, but usually the width (pitch) of the pattern portion in the direction orthogonal to the longitudinal direction of the striped pattern is 0.01 mm to 5 mm, and the etched portion The width (pitch) in the same direction is 0.01 mm to 5 mm.

1.2 Description of Each Step The method of the present invention includes the following steps (1) to (4).
(1) The light transmission is performed such that the longitudinal direction of the striped pattern is α ° (5 ° ≦ α ≦ 85 °) with respect to the x-axis direction, and the surface having the striped pattern faces the positive z-axis direction. A conductive conductive film is arranged on the xy plane, and a device for projecting a reference pattern on which at least one linear light-dark boundary appears, and a CCD camera are arranged on the yz plane so that the incident angle and the regular reflection angle are equal. The step of:
(2) projecting the reference pattern onto the surface of the light-transmitting conductive film;
(3) forming a fluctuation of the reflected image of the reference pattern and subjecting a video signal obtained by photographing with the CCD camera to image processing;
(4) In the image obtained by the image processing, when a saw-shaped light / dark boundary is observed, a cross section of a surface of the pattern portion corresponding to the light / dark boundary perpendicular to the longitudinal direction of the striped pattern A step of determining that the shape is an upwardly convex arc shape and that the cross-sectional shape of the etched portion corresponding to the light / dark boundary is a downwardly convex arc shape.

1.2.1 Explanation of Steps (1) and (2) 1.2.1.1 Explanation of Arrangement An example of arrangement of a device for projecting a reference pattern, a CCD camera, and a light transmissive conductive film together with a coordinate system It is shown in 1.

  When the longitudinal direction of the pattern portion is the x-axis direction, α = 0 °, and when the longitudinal direction of the pattern portion is the y-axis direction, α = 90 °.

  Since the striped pattern is aligned in one direction, the reflected image does not fluctuate if the projected reference pattern is parallel or orthogonal to the direction of the striped pattern. In the present invention, the fluctuation of the reflected image means a phenomenon in which the linearity is disturbed (discontinuity) in the reflected image of the linear pattern. Therefore, it is necessary that the directions of the projected reference pattern in the striped pattern are not at least parallel and not orthogonal. Specifically, the present invention can be implemented by setting 5 ° ≦ α ≦ 85 °. α is preferably 30 ° to 60 ° from the viewpoint of easy observation of fluctuations in the reflected image. In particular, when α is within this range, the degree of fluctuation of the reflected image is increased, which not only facilitates determination in step (4), but is also advantageous when performing curvature calculation described later.

  The apparatus for projecting the reference pattern and the CCD camera are arranged on the yz plane so that the incident angle and the regular reflection angle are equal. As shown in FIG. 1, the incident angle is an angle at which the reference pattern is projected with respect to the z axis. The regular reflection angle is an angle at which the reference pattern is regularly reflected when the z-axis is also used as a reference. In the following, as shown in FIG. 1, these angles may be expressed as θ. That is, incident angle = regular reflection angle = θ.

  Although not particularly limited, usually, 10 ° <θ <60 °, and preferably 20 ° <θ <45 ° from the viewpoint of device arrangement and workability.

1.2.1.2 Description of Projection Device The projection device used in the present invention is a device that projects a reference pattern on which at least one linear light / dark boundary appears.

  The reference pattern may be one in which one linear light / dark boundary appears, but may be one in which two or more light / dark boundaries appear.

  The projection apparatus is not particularly limited as long as the fluctuation of the reflected image can be confirmed in step (3), and may be an apparatus having any configuration.

  The projection apparatus may have a reference pattern and a light source as separate means, and project on the light-transmitting conductive film by illuminating the reference pattern. In this case, although it does not specifically limit as a light source, For example, a general incandescent lamp, a fluorescent lamp, a large sized discharge lamp, etc. can be used. Examples of general incandescent bulbs include tungsten bulbs and halogen bulbs. Examples of the fluorescent lamp include a white fluorescent lamp, a color rendering improvement type (white), and a three-wavelength light emission type (lunch color). Examples of the large discharge lamp include a fluorescent mercury lamp, a high pressure mercury lamp, a metal hydride lamp, and a high pressure sodium lamp.

  Further, the projection apparatus may have a configuration in which the reference pattern and the light source do not exist as separate means and can directly project the reference pattern. Examples of such a device include a liquid crystal display.

  The projection device illuminates the reference pattern to give sufficient brightness that image processing in step (3) can be performed on the fluctuation of the reflected image projected on the surface of the light-transmitting conductive film. If it is.

1.2.1.3 Description of CCD Camera The CCD camera used in the present invention collects the fluctuation of the reflected image on the surface of the image pickup element by a lens system, performs photoelectric conversion, and extracts it as a video signal (video signal). There is no particular limitation as long as it is possible.

  A CCD camera having a higher number of pixels is preferable in that the fluctuation of the reflected image can be captured more clearly and the subsequent analysis can be performed more accurately. In this respect, a CCD camera having 1 million pixels or more is preferable.

1.2.2 Explanation of Step (3) FIG. 2 shows an example of a video signal (video signal) obtained by photographing with a CCD camera.

  Although not particularly limited, image processing of a video signal (video signal) can be performed as follows, for example. A video signal (video signal) from the CCD camera is taken into the computer via the interface. The luminance distribution indicating the fluctuation of the reflected image is calculated and drawn by performing image processing on the intensity (video signal) of the light received by the image sensor that forms the fluctuation of the reflected image by the computer. Further, the light / dark boundary is calculated from the luminance distribution obtained by the image processing. At this time, the baseline may not be horizontal due to the waviness of the light-transmitting conductive film. In such a case, the baseline can be corrected to be horizontal by processing on the image software. Based on the image obtained at this time, the determination in the step (4) can be performed.

  The series of measurements described above is not particularly limited, but can be performed using a commercially available spectroscope. Although it does not specifically limit, For example, Ark Harima Co., Ltd. mirror surface meter "Mirror SPOT * F" or its equivalent etc. can be used.

1.2.3 Description of Step (4) If the cross-sectional shape of the light-transmitting conductive film is a combination of a plane and a slope as shown in FIG. The measurement data obtained by this image processing is discrete as shown in FIG.

  On the other hand, when the measurement data obtained by the image processing in the step (3) has a saw shape as shown in FIG. 4 (b), the cross-sectional shape of the light-transmitting conductive film is the upper part of the pattern portion. It is assumed that the etched portion has a downwardly convex arc shape.

  Furthermore, in the step (4), the step in the saw shape can be calculated, and the radius of curvature of each of the pattern portion and the etching portion having a circular cross section can be obtained based on the value. This calculation can be performed as follows.

  First, the pattern portion (upwardly convex arc shape) is calculated. The equation of the cylinder when the longitudinal direction of the pattern of curvature radius r extends in the x-axis direction is

It is. If this pattern is rotated α around the z axis, and the upper surface of the cylinder becomes z = 0, the coordinate conversion formula is as follows.

Substituting these into equation (1) yields:

  On the other hand, the equation of the planar ray at the incident angle θ in the yz plane is

It is. The z-coordinate of the intersection line of Equation (5) and Equation (6) can be obtained as follows by substituting y = z tanθ into Equation (5) from Equation (6).

  Therefore, by giving the value of x, z is determined from equation (7), and y is determined from equation (6), so the point on the intersection line is determined as (x, y, z) = (X, Y, Z) . The range of x is −L / (2sinα) to L / (2sinα) as can be seen from the middle pattern in FIG.

  Now, from the point (x, y, z) = (X, Y, Z) on the intersection line of the cylinder (5) and the planar light beam (6) in the pattern part, the center line (x, y, z) = ( (t cosα, t sinα, −r)

From t to

Therefore, it is expressed as follows.

Dividing the vector connecting the point (x, y, z) = (X, Y, Z) on the intersection line by the size of the vector, the unit normal vector n of the cylinder of the pattern part is obtained . The unit incidence vector v of the planar ray (6) is

Therefore, using this and the unit normal vector n of the cylinder of the pattern portion, the reflection vector r is as follows.

  If the distance from the light-transmissive conductive film to the CCD camera is P, a straight line that passes through the point (x, y, z) = (X, Y, Z) on the intersection line and extends in the direction of the reflection vector

Is the observation surface

The points (O _x , O _y , O _z ) that intersect with

Because

It becomes. The step on this observation plane is

It is expressed. A series of calculations is performed while changing the radius of curvature r, and the step in equation (17) matches the step calculated from the image data obtained in step (3), that is, the step calculated from the comparison with the scale whose length is known. R becomes the radius of curvature of the pattern portion. By substituting the value r of the radius of curvature into the equation (1), the step d of the pattern portion can be obtained as follows.

  The calculation of the etched portion (downwardly convex arc shape) can be performed in the same manner. In this case, the bottom surface of the cylinder is considered to be z = 0, and instead of equations (4) and (7)

And the center line of the cylinder may be (x, y, z) = (t cosα, t sinα, r).

1.2.4 Description of Step (5) In addition to steps (1) to (4), the method of the present invention may further include the following step (5).
(5) A step of obtaining the sum of the arc shape height of the pattern portion and the arc shape depth of the etching portion as a patterning step based on the radius of curvature obtained in the step (4). Specifically, using the formulas (1) to (18) and the formulas (4 ′) and (7 ′), the height of the arc shape of the pattern portion (the height of the pattern portion; FIG. )) And the arc-shaped depth of the etched portion (etched portion depth; arrow in FIG. 4 (a)), and the sum of both is calculated as a patterning step (dashed arrow in FIG. 4 (a)). ).

  When the method of the present invention further includes the following step (5) in addition to steps (1) to (4), it can be said that this method is a patterning step measurement method.

2. Method for Inspecting Patterning Step A method for inspecting a patterning step of the present invention is as follows.
A light transmissive conductive film having a light transmissive conductive layer partially etched on at least one surface,
The surface has a striped pattern composed of a pattern portion having a light-transmitting conductive layer and an etched portion, and a cross-sectional shape of the surface of the pattern portion perpendicular to the longitudinal direction of the striped pattern is high. A convex arc shape, and the cross-sectional shape of the etched portion corresponding to the light-dark boundary is a downward convex arc shape,
A method for inspecting a patterning step of a light transmissive conductive film,
This is a method of determining that the patterning step is good when the patterning step obtained as the sum of the arcuate height of the pattern part and the arcuate depth of the etching part is 0.3 μm or less.

The patterning step inspection method of the present invention preferably includes the following steps (i) to (iv):
(I) The light transmission so that the longitudinal direction of the striped pattern is α ° (5 ° ≦ α ≦ 85 °) with respect to the x-axis direction, and the surface having the striped pattern faces the positive z-axis direction. A conductive conductive film is arranged on the xy plane, and a device for projecting a reference pattern on which at least one linear light-dark boundary appears, and a CCD camera are arranged on the yz plane so that the incident angle and the regular reflection angle are equal. The step of:
(Ii) projecting the reference pattern onto the surface of the light transmissive conductive film;
(Iii) forming a fluctuation of a reflected image of the reference pattern and subjecting a video signal obtained by photographing with the CCD camera to image processing;
(Iv) A step of calculating a step in the saw shape obtained by the image processing, and obtaining a radius of curvature of each of the pattern portion and the etching portion having a circular cross section based on the value.

  If the patterning level difference calculated | required with the patterning level | step difference test | inspection method of this invention is 0.3 micrometer or less, the patterning level | step difference will become easy to visually recognize and it is favorable.

  Moreover, if the patterning level | step difference calculated | required with the patterning level | step difference test | inspection method of this invention is 0.2 micrometer or less, the patterning level | step difference will become easier to visually recognize and it is more favorable. Therefore, the patterning level | step difference test | inspection method of this invention is more preferable if it is a method of determining that it is favorable when the patterning level | step difference measured is 0.2 micrometer or less.

  A substantially proportional relationship is established between the patterning step required by the patterning step inspection method of the present invention and the step in the saw shape observed in the image obtained in step (iii). Therefore, when the patterning step required as the sum of the arc shape height of the pattern portion and the arc shape depth of the etching portion is 0.3 μm or less or 0.2 μm, When the step in the saw shape observed in the image obtained in the step (iii) is equal to or less than a predetermined value (this value is appropriately calculated), it can be replaced with a step of determining that the step is good.

3. Light-transmitting conductive film having a specific step The light-transmitting conductive film having a specific step of the present invention is a patterning that is the sum of the arc-shaped height of the pattern portion and the arc-shaped depth of the etched portion. It is a light transmissive conductive film manufactured so that a level | step difference may be 0.3 micrometer or less.

  In the light-transmitting conductive film having the step, the degree of the bone appearance phenomenon is improved. Specifically, since the degree of roundness of the arc shape is suppressed within a specific range, the degree of the bone appearance phenomenon is improved.

  Further, in terms of the improvement of the bone appearance phenomenon, the patterning step, which is the sum of the height of the arc shape of the pattern portion and the depth of the arc shape of the etching portion, is 0.2 μm or less. More preferably, it is a light-transmitting conductive film.

  The light-transmitting conductive film of the present invention may be one in which the light-transmitting conductive layer is disposed on the light-transmitting support layer directly or via one or more other layers. Although it does not specifically limit as another layer, For example, an undercoat layer, a hard-coat layer, an adhesive layer, etc. are mentioned.

  In FIG. 5, the one aspect | mode of the transparent electroconductive film of this invention is shown. In this embodiment, the light transmissive conductive layers are disposed adjacent to each other on one side of the light transmissive support layer.

  FIG. 6 shows another embodiment of the light transmissive conductive film of the present invention. In this aspect, the light transmissive conductive layers are disposed adjacent to each other on both surfaces of the light transmissive support layer.

  The light transmissive support layer refers to a light transmissive conductive film containing a light transmissive conductive layer that plays a role of supporting a layer including the light transmissive conductive layer. Although it does not specifically limit as a light transmissive support layer, For example, in the light transmissive conductive film for touch panels, what is normally used as a light transmissive support layer can be used.

  The material for the light transmissive support layer is not particularly limited, and examples thereof include various organic polymers. The organic polymer is not particularly limited. For example, polyester resin, acetate resin, polyether resin, polycarbonate resin, polyacrylic resin, polymethacrylic resin, polystyrene resin, polyolefin resin, polyimide resin, etc. Examples thereof include resins, polyamide resins, polyvinyl chloride resins, polyacetal resins, polyvinylidene chloride resins, and polyphenylene sulfide resins. Although it does not specifically limit as polyester-type resin, For example, a polyethylene terephthalate (PET), a polyethylene naphthalate (PEN), etc. are mentioned. The material of the light transmissive support layer is preferably a polyester resin, and particularly preferably PET. The light transmissive support layer may be composed of any one of these, or may be composed of a plurality of types.

  Although the thickness of a light-transmissive support layer is not specifically limited, For example, the range of 2-300 micrometers is mentioned.

  The light transmissive conductive film of the present invention may further include an undercoat layer, and at least one light transmissive conductive layer may be disposed on the surface of the light transmissive support layer via at least the undercoat layer. Good.

  The light transmissive conductive layer may be disposed adjacent to the undercoat layer.

  In FIG. 7, the one aspect | mode of the single-sided transparent electroconductive film of this invention is shown. In this embodiment, the undercoat layer and the light transmissive conductive layer are disposed adjacent to each other in this order on one surface of the light transmissive support layer.

  In FIG. 8, the one aspect | mode of the double-sided transparent electroconductive film of this invention is shown. In this embodiment, the undercoat layer and the light transmissive conductive layer are disposed adjacent to each other in this order on both sides of the light transmissive support layer.

  Although the material of an undercoat layer is not specifically limited, For example, you may have a dielectric property. The material of the undercoat layer is not particularly limited. For example, silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, silicon alkoxide, alkylsiloxane and its condensate, polysiloxane, silsesquioxane, polysilazane, oxidation Niobium (V) and the like. The undercoat layer may be composed of any one of them, or may be composed of a plurality of types.

As the undercoat layer, a layer containing SiO _x (x = 1.0 to 2.0) is preferable. The undercoat layer may be a layer made of SiO _x (x = 1.0 to 2.0).

One layer of the undercoat layer may be disposed. Alternatively, two or more layers may be arranged adjacent to each other or separated from each other via other layers. Two or more undercoat layers are preferably arranged adjacent to each other. For example, when three layers are arranged adjacent to each other, an undercoat layer made of SiO ₂ is arranged in the middle, and an undercoat layer made of SiO _x (x = 1.0 to 2.0) is arranged so as to sandwich it. It is preferable to do so.

  Although it does not specifically limit as thickness per one layer of an undercoat layer, For example, 5-50 nm etc. are mentioned. When two or more layers are disposed adjacent to each other, the total thickness of all the undercoat layers adjacent to each other may be within the above range.

  The refractive index of the undercoat layer is not particularly limited as long as the light-transmitting conductive film of the present invention can be used as a light-transmitting conductive film for a touch panel. For example, 1.4 to 1.5 is preferable.

  The method for disposing the undercoat layer may be either wet or dry, and is not particularly limited. Examples of the wet include a sol-gel method, a fine particle dispersion, and a method of applying a colloidal solution.

  As a method for disposing the undercoat layer, as a dry method, for example, a sputtering method, an ion plating method, a vacuum evaporation method, a chemical vapor deposition method, a method of laminating on an adjacent layer by a pulse laser deposition method, or the like can be given. It is done.

  The light transmissive conductive film of the present invention may further contain a hard coat layer.

  When the light transmissive conductive film of the present invention contains a hard coat layer, at least one light transmissive conductive layer is disposed on the surface of the light transmissive support layer via at least the hard coat layer.

  One layer of the hard coat layer may be disposed. Alternatively, two or more layers may be arranged adjacent to each other or separated from each other via other layers.

  The hard coat layer may be disposed on both surfaces of the light transmissive support layer.

  In FIG. 9, the one aspect | mode of the single-sided transparent electroconductive film of this invention containing a hard-coat layer is shown. In this embodiment, the hard coat layer, the undercoat layer, and the light transmissive conductive layer are arranged adjacent to each other in this order on one surface of the light transmissive support layer.

  FIG. 10 shows another embodiment of the single-sided light-transmitting conductive film of the present invention containing a hard coat layer. In this embodiment, the hard coat layer, the undercoat layer, and the light transmissive conductive layer are arranged adjacent to each other in this order on one surface of the light transmissive support layer, and on the other surface of the light transmissive support layer. Another hard coat layer is placed directly.

  In FIG. 11, the one aspect | mode of the double-sided transparent electroconductive film of this invention containing a hard-coat layer is shown. In this embodiment, the hard coat layer, the undercoat layer, and the light transmissive conductive layer are arranged adjacent to each other in this order on both sides of the light transmissive support layer.

  In the present invention, the hard coat layer refers to a layer that plays a role of preventing scratches on the surface of the light-transmitting support layer. Although it does not specifically limit as a hard-coat layer, For example, what is normally used as a hard-coat layer in the transparent conductive film for touchscreens can be used.

  The material for the hard coat layer is not particularly limited, and examples thereof include acrylic resins, silicone resins, urethane resins, melamine resins, and alkyd resins. Examples of the material for the hard coat layer further include those obtained by dispersing colloidal particles such as silica, zirconia, titania and alumina in the resin. The hard coat layer may be composed of any one of these, or may be composed of a plurality of types. As the hard coat layer, an acrylic resin in which zirconia particles are dispersed is preferable.

  The thickness of the hard coat layer (the total thickness of the two layers when the two layers are arranged adjacent to each other) (μm) is 1 μm to 10 μm.

  The method of disposing the hard coat layer is not particularly limited, and examples thereof include a method of applying to a film and curing with heat, a method of curing with active energy rays such as ultraviolet rays and electron beams, and the like. From the viewpoint of productivity, a method of curing with ultraviolet rays is preferable.

  The light-transmitting conductive film of the present invention is used for manufacturing a touch panel. Details of the touch panel are as described below.

  The touch panel of the present invention includes the light-transmitting conductive film of the present invention, and further includes other members as necessary.

Specific examples of the configuration of the capacitive touch panel according to the present invention include the following configurations. The protective layer (1) side is used so that the operation screen side faces, and the glass (5) side faces the side opposite to the operation screen.
(1) Protective layer (2) Light transmissive conductive film of the present invention (Y-axis direction)
(3) Insulating layer (4) Light transmissive conductive film of the present invention (X-axis direction)
(5) Glass Although the touch panel of this invention is not specifically limited, For example, it can manufacture by combining said (1)-(5) and another member according to a normal method as needed.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

1. Sample Preparation A light transmissive conductive film using ITO as a light transmissive conductive film was cut into a 10 cm square, and heat-treated at 150 ° C. for 60 minutes to crystallize the ITO film. A photoresist was applied to the crystallized light-transmitting conductive film, and exposure and development processes were performed, and patterning was performed so that the pattern portion had a width L of 4 mm and an etching portion had a width S. After rinsing and drying, the ITO film was etched by immersing in an aqua regia type etching solution at 25 ° C. for 15 minutes. Thereafter, the photoresist was removed by immersion in a 1% potassium hydroxide solution at 25 ° C. for 5 minutes. Finally, heat treatment was performed at 130 ° C. for 40 minutes assuming a silver paste drying process.

2. Measurement Method The patterning step of the light transmissive conductive film prepared as described above was measured as follows.

  As a measuring device, a specular surface meter (trade name: Mirror SPOT · F) manufactured by Ark Harima Co., Ltd. was used. As a light source, a black and white pattern was displayed on the LED backlight attached to the apparatus, and the specular reflection at 20 degrees was measured with respect to the sample. The prepared light-transmitting conductive film was placed so that the longitudinal direction of patterning was 45 degrees with respect to the light / dark boundary of the light source, and a stainless steel ring-shaped jig was placed to reduce the undulation of the film. Image data was obtained by photographing 20-degree specular reflection light from the sample with a CCD camera attached to the apparatus.

  After extracting the center point of the light / dark boundary from the image data and performing baseline correction, the average value of the steps of the light / dark boundary was used as the measurement value.

  On the other hand, using the diameter of the ring-shaped jig as a reference from the image data itself, the level difference between the light and dark boundaries is read, and using the equations (1) to (18) and equations (4 ') and (7'), The height and the depth of the etched part were calculated, and the sum of the two was used as the patterning step.

The visual step evaluation method is as follows. It was arranged so that the patterned ITO layer side was on the upper side, and whether or not the pattern portion and the etched portion could be distinguished was evaluated according to the following criteria. The viewing distance was 20 cm, and the viewing angle was 45 degrees from the sample surface.
○: Difficult to distinguish between patterning part and non-patterning part.
(Triangle | delta): A patterning part and a non-patterning part can be discriminate | determined slightly.
X: A patterning part and a non-patterning part can be distinguished clearly.
Example 1 A transparent conductive film (product name SCP125-170, manufactured by Sekisui Nanocoat Technology Co., Ltd.) was subjected to patterning with a pattern portion having a width L of 4 mm and an etched portion having a width S of 2 mm.
Example 2 A transparent conductive film (product name: SCP125-170, manufactured by Sekisui Nanocoat Technology Co., Ltd.) was subjected to patterning with a pattern portion having a width L of 4 mm and an etched portion having a width S of 0.5 mm.
Example 3 A transparent conductive film (product name: SCP125-150V3, manufactured by Sekisui Nanocoat Technology Co., Ltd.) was subjected to patterning with a pattern portion having a width L of 4 mm and an etched portion having a width S of 0.07 mm.
Comparative Example 1 A transparent conductive film (product name: SCP125-170, manufactured by Sekisui Nanocoat Technology Co., Ltd.) was subjected to patterning with a pattern portion width L of 4 mm and an etched portion width S of 4 mm.
Comparative Example 2 A transparent conductive film (product name: SCP125-150V3, manufactured by Sekisui Nanocoat Technology Co., Ltd.) was subjected to patterning with a pattern portion width L of 4 mm and an etched portion width S of 4 mm.
Comparative Example 3 A transparent conductive film (product name: SCP125-150V3, manufactured by Sekisui Nanocoat Technology Co., Ltd.) was subjected to patterning with a pattern portion having a width L of 4 mm and an etched portion having a width S of 1 mm.

  The results are shown in Table 1. It has been found that a substantially proportional relationship is established between the light / dark boundary step of the specular recording and the patterning step measured by the method of the present invention, and the light / dark boundary step of the specular recording is 1.5 or less (the method of the present invention). The patterning step is less visible when the patterning step is 0.3 μm or less), and is less visible when the patterning step is less than 1 (the patterning step measured by the method of the present invention is less than about 0.2 μm). It was.

DESCRIPTION OF SYMBOLS 1 Light transmissive conductive film 11 Light transmissive support layer 12 Light transmissive conductive layer 13 Undercoat layer 14 Hard coat layer

Claims (5)

A light transmissive conductive film having a light transmissive conductive layer partially etched on at least one surface,
The surface is a method for evaluating a patterning step of a light transmissive conductive film having a striped pattern composed of a pattern portion having a light transmissive conductive layer and an etched portion, and the following steps (1) to ( 4) containing method:
(1) The light transmission is performed such that the longitudinal direction of the striped pattern is α ° (5 ° ≦ α ≦ 85 °) with respect to the x-axis direction, and the surface having the striped pattern faces the positive z-axis direction. A conductive conductive film is arranged on the xy plane, and a device for projecting a reference pattern on which at least one linear light-dark boundary appears, and a CCD camera are arranged on the yz plane so that the incident angle and the regular reflection angle are equal. The step of:
(2) projecting the reference pattern onto the surface of the light-transmitting conductive film;
(3) forming a fluctuation of the reflected image of the reference pattern and subjecting a video signal obtained by photographing with the CCD camera to image processing;
(4) When a saw-shaped light / dark boundary is observed in the image obtained by the image processing, a cross-sectional shape of a surface of the pattern portion corresponding to the light / dark boundary perpendicular to the longitudinal direction of the striped pattern Determining that the cross-sectional shape of the etched portion corresponding to the light-dark boundary is a downwardly convex arc shape. 2. The method according to claim 1, wherein in the step (4), a step in the saw shape is calculated, and a curvature radius of each of the pattern portion and the etching portion having a circular cross section is obtained based on the value. The method according to claim 1, wherein α is 30 ° to 60 °. further,
(5) The method includes a step of obtaining, as a patterning step, a sum of an arc shape height of the pattern portion and an arc shape depth of the etching portion based on the radius of curvature obtained in the step (4). Item 4. The method according to Item 2 or 3. A light transmissive conductive film having a light transmissive conductive layer partially etched on at least one surface,
The surface has a striped pattern composed of a pattern portion having a light-transmitting conductive layer and an etched portion, and a cross-sectional shape of the surface of the pattern portion perpendicular to the longitudinal direction of the striped pattern is high. A convex arc shape, and the cross-sectional shape of the etched portion corresponding to the light-dark boundary is a downward convex arc shape,
A method for inspecting a patterning step of a light transmissive conductive film,
The following steps (i) to (iv):
(I) The light transmission so that the longitudinal direction of the striped pattern is α ° (5 ° ≦ α ≦ 85 °) with respect to the x-axis direction, and the surface having the striped pattern faces the positive z-axis direction. Disposing the conductive film in the xy plane, and
Disposing an apparatus for projecting a reference pattern on which at least one linear light-dark boundary appears, and a CCD camera on the yz plane so that an incident angle and a regular reflection angle are equal;
(Ii) projecting the reference pattern onto the surface of the light transmissive conductive film;
(Iii) forming a fluctuation of a reflected image of the reference pattern and subjecting a video signal obtained by photographing with the CCD camera to image processing;
(Iv) calculating a step in the saw shape obtained by the image processing, and obtaining a curvature radius of each of the pattern portion and the etching portion having a circular cross section based on the value;
And the patterning step required as the sum of the arc-shaped height of the pattern portion and the arc-shaped depth of the etched portion is determined to be good when it is 0.3 μm or less. ,
Method.

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