JP2017206679A - Substrate film with transparent adhesive layer, transparent conductive film with transparent adhesive layer, and touch panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate film with a transparent adhesive layer, which shows no decrease in adhesiveness between the transparent adhesive layer and the substrate film and can suppress degradation in visibility, a transparent conductive film with a transparent adhesive layer using the above substrate film with a transparent adhesive layer, and a touch panel.SOLUTION: A substrate film 4 with a transparent adhesive layer includes a substrate film 2 for disposing a transparent conductive thin film on a side of one surface 2a thereof, and a transparent adhesive layer 3 laminated on the other surface 2b of the substrate film, in which the substrate film 2 has a transparent plastic film 6 and hard coat layers 7, 8 on both surfaces thereof, and the surface roughness on a face 3a of the transparent adhesive layer 3 opposite to the substrate film 2, in terms of a three-dimensional arithmetic average roughness Sa, is 30 nm or less.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a base film with a transparent adhesive layer, a transparent conductive film with a transparent adhesive layer, and a touch panel, and particularly to a base film with a transparent adhesive layer with improved visibility.

  Conventionally, capacitive touch panels have been widely used as devices that can input information by touching a display screen, such as smartphones and tablet terminals. Here, as a transparent conductive film for touch panels, what laminated | stacked indium tin oxide (ITO: indium tin oxide) by methods, such as vapor deposition or sputtering, was common on the base film (for example, Patent Document 1).

  This transparent conductive film may be damaged by crystallization of ITO or subsequent processes, such as scratching the plastic film. To prevent this, the ITO thin film or the ITO thin film in the base film is crystallized. The protective film provided with the adhesion layer was affixed on the surface on the opposite side to the side with the converted transparent conductive thin film.

  In addition to the case where the protective film is attached to a film having an ITO thin film or a film having a transparent conductive thin film (transparent conductive film) as described above, the substrate before the ITO thin film is laminated In some cases, the base film was prevented from being damaged during the lamination of ITO, the crystallization of ITO, or the subsequent steps.

  Then, after the above process, the transparent conductive film with the protective film is peeled off together with the adhesive film for bonding at the time of assembling the touch panel, and the optical transparent adhesive tape (OCA tape: optical clear adhesive) is applied. As a result, the transparent conductive film was newly provided with an optical transparent adhesive layer (OCA layer).

Japanese Patent Laid-Open No. 7-68690

  By the way, in the conventional transparent conductive film with a protective film, when the protective film is peeled off, the adhesive component in the adhesive layer of the protective film is, for example, a process for crystallizing ITO or heat in other processes. In some cases, adhesive residue remaining on the base film side may be generated due to the influence of the adhesive. For this reason, the substrate film and the optical transparent adhesive tape (OCA tape) to be bonded may impair the adhesion due to an air interface between them, or the transparent conductive film may be When used for a touch panel or the like, the visibility may be reduced. Moreover, this visibility was influenced not only by the state of the surface on the side where the base film is present in the transparent adhesive layer of the OCA tape, but also by the state of the opposite surface.

  The present invention has been made to solve the above-described conventional drawbacks, and the object of the present invention is not to impair the adhesion between the transparent adhesive layer and the base film, and to reduce visibility. It is providing the base film with a transparent adhesion layer, the transparent conductive film with a transparent adhesion layer, and a touch panel which can suppress.

The substrate film with a transparent adhesive layer, the transparent conductive film with a transparent adhesive layer, and the touch panel according to the present invention have the following configurations in order to achieve the object. That is,
The base film with a transparent adhesive layer according to the invention of claim 1 is formed by laminating a transparent adhesive layer on the other surface of a base film for providing a transparent conductive thin film on one surface side. Here, the base film with a transparent adhesive layer includes the base film having a transparent plastic film and the transparent adhesive layer formed by applying an adhesive to the other surface of the base film. And as for the surface roughness of the surface on the opposite side to the side with the said base film of the said transparent adhesion layer, three-dimensional arithmetic mean roughness Sa is 30 nm or less.

  According to this substrate film with a transparent adhesive layer, the transparent adhesive layer is formed by applying an adhesive to the other surface of the substrate film opposite to the one surface on which the transparent conductive thin film is provided. Is done. For this reason, the pasting to the transparent adhesive tape for optical (OCA tape) seen conventionally is unnecessary, the adhesive residue accompanying a pasting does not occur, and the adhesiveness of a transparent adhesive layer and a substrate film may be impaired. Furthermore, a decrease in visibility due to this poor adhesion can be suppressed. In addition, the transparent adhesive layer has a surface roughness on the side opposite to the side on which the base film is present, and the three-dimensional arithmetic average roughness Sa is 30 nm or less. Reduction is suppressed.

  Moreover, the base film with a transparent adhesive layer which concerns on invention of Claim 2 is a base film with a transparent adhesive layer of Claim 1, What is the side with the said base film of the said transparent adhesive layer? A release film is bonded to the opposite surface.

  Moreover, the base film with a transparent adhesive layer which concerns on invention of Claim 3 is a base film with a transparent adhesive layer of Claim 1 or 2, The said base film is one side of the said transparent plastic film The surface has a first hard coat layer, and the surface of the first hard coat layer opposite to the side having the transparent plastic film is one surface of the base film.

  Moreover, the base film with a transparent adhesive layer which concerns on invention of Claim 4 is a base film with a transparent adhesive layer of any one of Claim 1 thru | or 3, The said base film is the said transparent The other surface of the plastic film has a second hard coat layer, and the surface of the second hard coat layer opposite to the side on which the transparent plastic film is located is the other surface of the base film. It becomes.

  Moreover, the base film with a transparent adhesive layer which concerns on invention of Claim 5 is a base film with a transparent adhesive layer of any one of Claims 1 thru | or 4, The said adhesive is (meta). It is formed from an adhesive composition containing an acrylic ester copolymer, an isocyanate-based crosslinking agent, and an organic tin compound.

  Moreover, the base film with a transparent adhesive layer according to the invention of claim 6 is the base film with a transparent adhesive layer according to claim 5, wherein the organic tin compound is the isocyanate-based cross-linking. It contains 20-30 parts by weight with respect to 100 parts by weight of the agent.

  Moreover, the base film with a transparent adhesion layer which concerns on invention of Claim 7 is a base film with a transparent adhesion layer of Claim 5 or 6, The said (meth) acrylic acid ester copolymer is ( It is a copolymer comprising a (meth) acrylic acid alkyl monomer and a hydroxyl group-containing monomer as essential components.

  The transparent conductive film with a transparent adhesive layer according to the invention of claim 8 is provided with a transparent conductive thin film on one surface side of the base film, and the transparent adhesive layer on the other surface of the base film. Are laminated. Here, the transparent conductive film with a transparent adhesive layer includes the base film having a transparent plastic film, the transparent conductive thin film provided on one surface side of the base film, and the other of the base film. And the transparent adhesive layer formed by applying an adhesive to the surface. And as for the surface roughness of the surface on the opposite side to the side with the said base film of the said transparent adhesion layer, three-dimensional arithmetic mean roughness Sa is 30 nm or less.

  According to this transparent conductive film with a transparent adhesive layer, the transparent adhesive layer is coated with an adhesive on the other side of the base film opposite to the one side where the transparent conductive thin film is provided. It is formed. For this reason, the pasting to the transparent adhesive tape for optical (OCA tape) seen conventionally is unnecessary, the adhesive residue accompanying a pasting does not occur, and the adhesiveness of a transparent adhesive layer and a substrate film may be impaired. Furthermore, a decrease in visibility due to this poor adhesion can be suppressed. In addition, the transparent adhesive layer has a surface roughness on the side opposite to the side on which the base film is present, and the three-dimensional arithmetic average roughness Sa is 30 nm or less. Reduction is suppressed.

  The transparent conductive film with a transparent adhesive layer according to claim 9 is the transparent conductive film with a transparent adhesive layer according to claim 8, wherein the side of the transparent adhesive layer on which the base film is present. A release film is bonded to the surface on the opposite side.

  Moreover, the touchscreen which concerns on invention of Claim 10 is formed using the transparent conductive film with a transparent adhesive layer of Claim 8 by using 1 sheet or multiple sheets.

  According to the base film with a transparent adhesive layer, the transparent conductive film with a transparent adhesive layer, and the touch panel according to the present invention, the other side of the base film opposite to the one side on which the transparent conductive thin film is provided. The surface is provided with a transparent adhesive layer formed by applying an adhesive, and the three-dimensional arithmetic average roughness is the surface roughness of the surface of the transparent adhesive layer opposite to the side having the base film. By making Sa into 30 nm or less, the adhesiveness of a transparent adhesion layer and a base film is not impaired, and the fall of visibility can be suppressed.

It is a cross-sectional schematic diagram of the base film with a transparent adhesion layer of one embodiment of this invention. Similarly, it is a cross-sectional schematic diagram of a transparent conductive film with a transparent adhesive layer. Similarly, it is a cross-sectional schematic diagram of a touch panel.

  EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing the base film with a transparent adhesive layer which concerns on this invention, the transparent conductive film with a transparent adhesive layer, and a touch panel is demonstrated based on drawing.

  1 to 3 show an embodiment of the present invention. Reference numeral 1 in the figure indicates a transparent conductive thin film. 2 shows the base film for providing the said transparent conductive thin film 1 in the one surface 2a side. 3 shows a transparent adhesion layer. 4 shows a base film with a transparent adhesive layer, specifically, a base film with a transparent adhesive layer for a transparent conductive film. 5 shows a transparent conductive film with a transparent adhesive layer.

  As shown in FIG. 1, the base film 4 with a transparent adhesive layer is formed on the other surface 2b of the base film 2 (that is, the surface opposite to the one surface 2a side on which the transparent conductive thin film 1 is provided). The transparent adhesive layer 3 is laminated. Here, the base film 2 has a transparent plastic film 6. The transparent adhesive layer 3 is formed by applying an adhesive to the other surface 2 b of the base film 2. And as for the surface roughness of the surface 3a on the opposite side to the side with the base film 2 of the transparent adhesion layer 3, three-dimensional arithmetic average roughness Sa is 30 nm or less. In addition, in the base film 4 with the transparent adhesive layer, the release film 14 is bonded to the surface 3a of the transparent adhesive layer 3 opposite to the side on which the base film 2 is present.

  As shown in FIG. 2, the transparent conductive film 5 with the transparent adhesive layer is provided with the transparent conductive thin film 1 on the one surface 2 a side of the base film 2 and transparent on the other surface 2 b of the base film 2. The adhesive layer 3 is laminated. Here, the base film 2 has a transparent plastic film 6. The transparent adhesive layer 3 is formed by applying an adhesive to the other surface 2 b of the base film 2. And as for the surface roughness of the surface 3a on the opposite side to the side with the base film 2 of the transparent adhesion layer 3, three-dimensional arithmetic average roughness Sa is 30 nm or less. In addition, in the transparent conductive film 5 with the transparent adhesive layer, the release film 14 is bonded to the surface 3a of the transparent adhesive layer 3 opposite to the side on which the base film 2 is provided.

  That is, the transparent conductive film 5 with the transparent adhesive layer has a configuration in which the transparent conductive thin film 1 is provided on the one surface 2a side of the base film 4 with the transparent adhesive layer described above. However, in the production of the transparent conductive film 5 with the transparent adhesive layer, the transparent conductive thin film 1 is provided on the base film 4 with the transparent adhesive layer, or the transparent conductive thin film 1 is provided on the base film 2. And then laminating the transparent adhesive layer 3 or laminating, for example, indium tin oxide (ITO) on the base film 2, laminating the transparent adhesive layer 3 on the base film 2 on which the ITO is laminated, The process sequence is arbitrary, such as crystallizing ITO to form the transparent conductive thin film 1.

  Specifically, the base film 2 has a first hard coat layer 7 on one surface of the transparent plastic film 6, and the side of the first hard coat layer 7 on which the transparent plastic film 6 is provided. The opposite surface is the one surface 2 a of the base film 2. The base film 2 has a second hard coat layer 8 on the other surface of the transparent plastic film 6, and the second hard coat layer 8 is opposite to the side on which the transparent plastic film 6 is present. This surface is the other surface 2b of the base film 2.

  FIG. 3 shows a touch panel 9, which is formed by using one or a plurality of transparent conductive films 5 with a transparent adhesive layer (two in the illustrated embodiment). Specifically, the touch panel 9 includes a position input device 10 and a display device 11 such as a liquid crystal module. Then, the position input device 10 is formed by stacking two transparent conductive films 5 with a transparent adhesive layer from which the release film 14 has been peeled off, and a glass plate 13 is attached to the surface side with an OCA tape 12. Here, the two transparent conductive films 5 and 5 with a transparent adhesive layer are bonded together by the transparent adhesive layer 3 of the transparent conductive film 5 with a transparent adhesive layer located outside. The position input device 10 is bonded to the display device 11 by the transparent adhesive layer 3 of the transparent conductive film 5 with the transparent adhesive layer inside.

  Specifically, as the material of the transparent plastic film 6, for example, polyethylene terephthalate (PET), polyester such as polyethylene naphthalate, polycarbonate (polycarbonate: PC), polyalkyl (meth) acrylate, polystyrene, polyimide, Polyolefins such as polyarylate, polyacrylonitrile, cyclopolyolefin (cycloolefin polymer cyclic olefin polymer: COP, or cycloolefin copolymer cyclic olefin: COC), polyphenylene sulfide, polyvinylidene chloride, polyvinyl alcohol, etc., especially polyethylene terephthalate PET), polycarbonate (PC), cyclo polyolefin (COP, COC) is preferred. The thickness of the transparent plastic film 6 is preferably in the range of 2 to 500 μm, and in the range of 2 to 200 μm, the balance between the mechanical strength as a film for the transparent conductive film and the thinning of the film. And more preferable.

  Examples of the hard coat liquid used for the first and second hard coat layers 7 and 8 laminated on the transparent plastic film 6 include ultraviolet curable, electron beam curable, and thermosetting hard coat liquids. From the viewpoint of productivity and scratch resistance during the process, an ultraviolet curable hard coat liquid is preferred. Moreover, monofunctional (meth) acrylate, polyfunctional (meth) acrylate, etc. are mentioned as a main monomer which comprises this ultraviolet curable hard-coat liquid.

  The first hard coat layer 7 preferably has a refractive index in the range of 1.60 to 1.80 at a light wavelength of 589 nm, whereby the first hard coat layer 7 is made to be an optical adjustment layer ( IM layer). The first hard coat layer 7 is formed of, for example, an organic material, an inorganic material, or a mixture of an organic material and an inorganic material. Examples of the inorganic substance include zinc oxide, barium oxide, indium tin oxide, zirconium oxide, ytterbium oxide, yttrium oxide, tantalum oxide, aluminum oxide, cerium oxide, and titanium oxide. In particular, titanium oxide and zirconium oxide are preferable, and zirconium oxide is more preferable from the viewpoint of transparency of the transparent conductive film obtained later.

  The second hard coat layer 8 is formed of, for example, an organic material, an inorganic material, or a mixture of an organic material and an inorganic material.

  The thickness of the first and second hard coat layers 7 and 8 after curing is preferably 0.75 to 5.00 μm, and more preferably 0.75 to 2.00 μm. It is good. This is because if the thickness is small, the hardness as the hard coat layer is weak, and if it is too thick, it is disadvantageous in terms of cost.

  For forming the hard coat layers 7 and 8, for example, a reverse gravure coating method, a direct gravure coating method, a die coating method, a bar coating method, a wire bar coating method, a roll coating method, a spin coating method, a dip coating method, and a spray coating method. A coating method such as a knife coating method or a kiss coating method can be used. In addition, if the surface of the transparent plastic film 6 is subjected to surface easy adhesion treatment such as coating of an easy adhesion layer or corona discharge treatment, the adhesion of the hard coat layers 7 and 8 to the transparent plastic film 6 can be improved. .

  Examples of the pressure-sensitive adhesive forming the transparent pressure-sensitive adhesive layer 3 include an acrylic pressure-sensitive adhesive, a silicone pressure-sensitive adhesive, and a urethane pressure-sensitive adhesive. In particular, the acrylic pressure-sensitive adhesive is excellent in optical transparency and heat resistance. Therefore, it is preferable.

  The acrylic pressure-sensitive adhesive comprises a pressure-sensitive adhesive composition containing a (meth) acrylic acid ester copolymer ((meth) acrylate copolymer), an isocyanate-based crosslinking agent, and an organic tin compound (organotin compound). Preferably it is formed. In the present specification, the (meth) acrylic acid ester copolymer means an acrylic acid ester copolymer (methacrylic acid ester copolymer) or a methacrylic acid ester copolymer (methacrylic acid ester copolymer). The organotin compound functions as a crosslinking accelerator. Examples of the organotin compound include dioctyltin dilaurate, dibutyltin dilaurate, dibutyltin dimaleate, and dihexyltin diacetate (dihexyltin diacetate). dihexyltin diacetate). The organotin compound is preferably contained in an amount of 20 to 30 parts by weight with respect to 100 parts by weight of the isocyanate crosslinking agent. When the content is less than 20 parts by weight, the three-dimensional arithmetic average roughness Sa, which is the surface roughness of the surface 3a of the transparent adhesive layer 3 opposite to the side where the base film 2 is present, is 30 nm. There is a risk of exceeding. Further, when the content exceeds 30 parts by weight, the three-dimensional arithmetic average roughness Sa, which is the surface roughness of the surface 3a, is reduced, but the improvement of crosslinking is not so much recognized for the amount. In addition, a significant increase in viscosity occurs during the preparation of the pressure-sensitive adhesive composition, which may adversely affect its coatability. In this way, when the content of the organic tin compound is suppressed to a range that does not adversely affect the coatability, the three-dimensional arithmetic average roughness Sa that is the surface roughness of the surface 3a of the transparent adhesive layer 3 is reduced. There is a limit to this, and it is difficult to make the value less than 10 nm. In addition, when the three-dimensional arithmetic average roughness Sa, which is the surface roughness of the surface 3a, is adjusted to be less than 10 nm, the transparent adhesive layer 3 itself is often hard, and there is a possibility that the adhesive force is remarkably impaired. Therefore, the three-dimensional arithmetic average roughness Sa, which is the surface roughness of the surface 3a, is desirably 10 nm or more.

  Examples of the (meth) acrylate copolymer include isostearyl (meth) acrylate, stearyl (meth) acrylate, lauryl (meth) acrylate, dodecyl (meth) acrylate, decyl (meth) acrylate, ( Isononyl (meth) acrylate, nonyl (meth) acrylate, isooctyl (meth) acrylate, octyl (meth) acrylate, isobutyl (meth) acrylate, n-butyl (meth) acrylate, pentyl (meth) acrylate, (Meth) acrylic acid such as hexyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, propyl (meth) acrylate, ethyl (meth) acrylate, methyl (meth) acrylate, etc. Alkyl monomer (alkyl (meth) acrylate monome) r), or (meth) acrylic acid, or a carboxyl group-containing monomer such as carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, or 12-hydroxylauryl (meth) acrylate, (meth) 10-hydroxydecyl acrylate, 8-hydroxyoctyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, (meth) Hydroxyl group-containing monomers such as 2-hydroxyethyl acrylate are used, and these can be obtained by appropriately polymerizing them. However, from the viewpoint of the mechanical properties of the transparent adhesive layer 3, the (meth) acrylic acid ester copolymer is a copolymer having a (meth) acrylic acid alkyl monomer and a hydroxyl group-containing monomer as essential components. Is preferred.

  Examples of the isocyanate-based crosslinking agent include adduct-type isocyanate compounds, isocyanurate-type isocyanate compounds, burette-type isocyanate compounds, and urethane prepolymer-type isocyanate compounds.

  For forming the transparent adhesive layer 3, for example, reverse gravure coating method, direct gravure coating method, die coating method, bar coating method, wire bar coating method, roll coating method, spin coating method, dip coating method, spray coating method, knife Coating methods such as a coating method and a kiss coating method can be used.

  The thickness of the transparent adhesive layer 3 is preferably in the range of 5 to 100 μm, and more preferably in the range of 15 to 30 μm. If the thickness of the transparent adhesive layer 3 is thin, the necessary adhesive force cannot be obtained on the surface 3a opposite to the side where the base film 2 is present. Moreover, when too thick, there exists a possibility that it may become disadvantageous in terms of cost, such as raw material cost and coating efficiency.

  Next, the effect of the base film 4 with a transparent adhesion layer which consists of the above structure, the transparent conductive film 5 with a transparent adhesion layer, and the touch panel 9 is demonstrated. The transparent adhesive layer 3 in the base film 4 with the transparent adhesive layer, the transparent conductive film 5 with the transparent adhesive layer, or the touch panel 9 is the same as the surface 2a side of the base film 2 on which the transparent conductive thin film 1 is provided. Is formed by applying a pressure-sensitive adhesive on the opposite surface 2b. For this reason, the pasting to the transparent adhesive tape for optical (OCA tape) seen conventionally is unnecessary, the adhesive residue accompanying a pasting does not occur, and the adhesiveness of the transparent adhesive layer 3 and the base film 2 is impaired. In addition, a reduction in visibility due to this poor adhesion can be suppressed. The transparent adhesive layer 3 has a surface roughness of the surface 3a opposite to the side on which the base film 2 is present, and the three-dimensional arithmetic average roughness Sa is 30 nm or less. The surface 3a on the opposite side Visibility degradation due to is suppressed.

  That is, a transparent adhesive layer 3 formed by applying an adhesive to the other surface 2b of the base film 2 opposite to the one surface 2a side where the transparent conductive thin film 1 is provided, and The three-dimensional arithmetic average roughness Sa, which is the surface roughness of the surface 3a opposite to the side of the base film 2 of the transparent adhesive layer 3, is 30 nm or less, while simplifying the number of steps. The adhesiveness between the transparent adhesive layer 3 and the base film 2 is not impaired, and a decrease in visibility when applied to a touch panel or the like can be suppressed.

  The pressure-sensitive adhesive forming the transparent pressure-sensitive adhesive layer 3 is formed from a pressure-sensitive adhesive composition containing a (meth) acrylic acid ester copolymer, an isocyanate-based crosslinking agent, and an organic tin compound, and the organic tin compound is an isocyanate. 20-30 weight part is contained with respect to 100 weight part of the system crosslinking agent. Thus, by setting the content of the organotin compound to 20 parts by weight or more with respect to 100 parts by weight of the isocyanate-based crosslinking agent, the surface of the surface 3a on the opposite side of the transparent adhesive layer 3 from the side on which the base film 2 is present is sufficient. It can be made smooth, and by setting it to 30 parts by weight or less, an increase in the viscosity of the prepared pressure-sensitive adhesive composition can be suppressed, and coating properties can be kept good.

  In addition, this invention is not necessarily limited to embodiment mentioned above, A various other change is possible. For example, the transparent conductive thin film 1 may not be provided directly on the one surface 2a of the base film 2 but may be provided via an optical adjustment layer or other layers.

  The base film 2 may have other layers in addition to or instead of the first hard coat layer 7 or the second hard coat layer 8. One or both of the first and second hard coat layers 7 and 8 may be omitted. Here, when the transparent adhesive layer 3 is directly provided on the surface of the transparent plastic film 6 without providing the second hard coat layer 8, an easy-adhesion layer is applied to the surface of the transparent plastic film 6 in advance, or a corona is used. Depending on the material of the transparent plastic film 6, it is preferable to perform oligomer block treatment on the surface depending on the surface easy adhesion treatment such as electric discharge treatment.

  Moreover, although the two transparent conductive films 5 with a transparent adhesive layer are used for the touchscreen 9, the transparent conductive film 5 with a transparent adhesive layer of one of them is the transparent conductive film which does not have a transparent adhesive layer, and By replacing with an OCA tape, one transparent conductive film 5 with a transparent adhesive layer may be used. In addition to the position input device 10 in the touch panel 9, the transparent conductive film 5 with the transparent adhesive layer is used in a display device such as a liquid crystal module in the touch panel 9, a display having no position input device, and other devices. Also good.

  Hereinafter, the present invention will be described more specifically with reference to examples. In addition, the various physical properties of the base film 2 and the base film 4 with a transparent adhesive layer produced in the following examples and comparative examples were measured or calculated with the following equipment.

  The coating film thickness was measured using a reflective spectral film thickness meter (manufactured by Filmmetrics, trade name: F20 film thickness measurement system), and the three-dimensional arithmetic average roughness of the surface of the transparent adhesive layer 3 was measured by a white interferometer. The Sa value calculated by (Ryoka System Co., Ltd., trade name: VertScan), and the refractive index of the hard coat layers 7, 8 are the multi-wavelength Abbe refractometers (trade name: DR-M2 made by Atago Co., Ltd.). Using. Moreover, the adhesiveness of the transparent adhesive layer 3 to the base film 2 is determined based on whether the coating film is cut with a knife and the surface is rubbed off. For the visibility evaluation, a glass plate with a substrate film 4 with a transparent adhesive layer pasted is used, and an image reflected through the substrate film 4 with a transparent adhesive layer is visually observed through this. Judgment was made based on degree (clearness). The degree of distortion was evaluated according to the following three-stage criteria.

○ “There is no distortion in the image and there is no practical problem”
△ “Slight distortion is observed in the image, but there is no practical problem”
× "There is a problem in practical use due to obvious distortion in the image"

Example 1
A suspension for hard coat in which zirconium oxide is dispersed with a particle diameter of about 60 nm on one surface of a transparent plastic film 6 made of an easily adhesive polyester film (trade name: UH33, manufactured by Toray Industries, Inc.) having a thickness of 23 μm. Coating was performed with a roll coater, and the coated film was heat-dried using a dryer oven under the conditions of 80 ° C. × 1 minute. Next, the coated film after drying is irradiated with ultraviolet rays (irradiation amount: 200 mJ / cm 2), whereby a hard film having a refractive index of 1.65 at a light wavelength of 589 nm and a thickness of about 1 μm is formed on the transparent plastic film 6. A coat layer 7 was provided. By applying the liquid hard coat material on the other side in the same operation, a base film 2 (hard coat film) having hard coat layers 7 and 8 having a thickness of about 1 μm on both sides was produced. .

  An alkyl acrylate copolymer (containing a hydroxyl group) is formed on the surface of the hard coat layer 8 opposite to the hard coat layer 7 containing the zirconium oxide of the prepared base film 2 (that is, the other surface 2b of the base film 2). A pressure sensitive adhesive material in which 20 parts by weight of dioctyltin dilaurate is added to 100 parts by weight of an isocyanate-based crosslinking agent to an acrylic pressure-sensitive adhesive mainly comprising an isocyanate-based crosslinking agent) Coating is performed with a lip coater, and the coated film is heated and dried at 130 ° C. for 1 minute using a dryer oven to provide a transparent adhesive layer 3 having a thickness of 22 μm on one side of the base film 2. It was. Next, a silicone release film 14 (trade name: HY-S10, manufactured by Higashiyama Film Co., Ltd.) having a polyester base material thickness of 125 μm is bonded to the transparent adhesive layer 3 to a branch pipe having a winding tension of 280 N and a diameter of 6 inches. 150 m of a rolled base film 4 with a transparent adhesive layer (hard coat film with a transparent adhesive layer having a width of 1250 mm) was produced. After curing at 25 ° C. for 7 days, the release film 14 was peeled off, and the surface roughness of the 5 m portion from the core of the surface 3a of the transparent adhesive layer 3 that was in contact was 3D arithmetic average roughness Sa of 23.5 nm. there were.

Example 2
A transparent adhesive layer is provided in the same manner as in Example 1 except that the monomer composition constituting the acrylic pressure-sensitive adhesive mainly composed of an alkyl acrylate copolymer (including a hydroxyl group-containing monomer) and an isocyanate-based crosslinking agent is changed. 200 m of base film 4 (hard coat film with a transparent adhesive layer having a width of 1250 mm) was produced. After curing at 25 ° C. for 7 days, the release film 14 was peeled off, and the surface roughness of the 5 m portion from the core of the surface 3a of the transparent adhesive layer 3 that was in contact was 3D arithmetic average roughness Sa of 21.5 nm. there were.

Comparative Example 1
Substrate film 4 with a transparent adhesive layer (hard coat film with a transparent adhesive layer having a width of 1250 mm) in the same manner as in Example 2 except that 15 parts by weight of dioctyltin dilaurate was added to 100 parts by weight of the isocyanate-based crosslinking agent. Was made 155 m. After curing at 25 ° C. for 7 days, the release film 14 was peeled off, and the surface roughness of the 5 m portion from the core of the surface 3a of the transparent adhesive layer 3 that was in contact with the surface was 39.8-nm arithmetic average roughness Sa of 39.8 nm. there were.

Comparative Example 2
Substrate film 4 with a transparent adhesive layer (transparent adhesive with a width of 1250 mm) in the same manner as Example 2 and Comparative Example 1 except that dioctyltin dilaurate was added in an amount of 4.2 parts by weight based on 100 parts by weight of the isocyanate-based crosslinking agent. 200 m of a hard coat film with a layer) was produced. After curing at 25 ° C. for 7 days, the release film 14 was peeled off, and the surface roughness of the 5 m portion from the core of the surface 3a of the transparent adhesive layer 3 that was in contact was 3D arithmetic average roughness Sa of 49.2 nm. there were.

Comparative Example 3
A pressure-sensitive adhesive material obtained by adding 20 parts by weight of dioctyltin dilaurate to 100 parts by weight of the isocyanate-based crosslinking agent was applied to the release surface of the silicone-based release film, and the coating film was formed by using a dryer oven. The transparent adhesive layer 3 having a thickness of 22 μm was provided on the release surface of the release film 14 by heat drying under the condition of ° C. × 1 minute. Next, the surface of the hard coat layer 8 opposite to the hard coat layer 7 containing zirconium oxide of the base film 2 (hard coat film) produced in Example 1 (that is, the other surface 2b of the base film 2). And the surface of the transparent adhesive layer 3 were bonded together. Otherwise, in the same manner as in Examples 1 and 2 and Comparative Examples 1 and 2, 170 m of base film 4 with a transparent adhesive layer (hard coat film with a transparent adhesive layer having a width of 1250 mm) was produced. After curing at 25 ° C. for 7 days, the release film 14 was peeled off, and the surface roughness of the 5 m portion from the core of the surface 3a of the transparent adhesive layer 3 that was in contact was 3D arithmetic average roughness Sa of 25.8 nm. there were.

Comparative Example 4
150 m of a base film 4 with a transparent adhesive layer (hard coat film with a transparent adhesive layer having a width of 1250 mm) was produced in the same manner as in Comparative Example 3 except that dioctyltin dilaurate was not added. After curing at 25 ° C. for 7 days, the release film 14 was peeled off, and the surface roughness of the 5 m portion from the core of the surface 3a of the transparent adhesive layer 3 that was in contact was 3D arithmetic average roughness Sa of 44.4 nm. there were.

  About the base film 4 with a transparent adhesion layer (hard coat film with a transparent adhesion layer) produced in the above Examples 1 and 2 and Comparative Examples 1-4, the result of having evaluated adhesiveness and visibility is shown in Table 1. Street.

  As apparent from Table 1, the transparent adhesive layer 3 is coated with an adhesive on the other surface 2b of the base film 2 opposite to the one surface 2a side on which the transparent conductive thin film 1 is provided. By being formed, the adhesion between the transparent adhesive layer 3 and the base film 2 is not impaired. Moreover, the surface roughness of the surface 3a is made by making the dioctyltin dilaurate (organotin compound) added to the adhesive forming the transparent adhesive layer 3 20 parts by weight or more with respect to 100 parts by weight of the isocyanate-based crosslinking agent. The three-dimensional arithmetic average roughness Sa becomes 30 nm or less, and visibility with no practical problem is obtained.

DESCRIPTION OF SYMBOLS 1 Transparent conductive thin film 2 Base film 2a One side 2b The other side 3 Transparent adhesive layer 3a The surface on the opposite side to the side with a base film 4 Base film with a transparent adhesive layer 5 Transparent conductive with a transparent adhesive layer Film 6 Transparent plastic film 7 First hard coat layer 8 Second hard coat layer 9 Touch panel 14 Release film

Claims (10)

The base film for providing a transparent conductive thin film on one surface side is a base film with a transparent adhesive layer formed by laminating a transparent adhesive layer on the other surface,
The substrate film having a transparent plastic film, and the transparent adhesive layer formed by applying an adhesive to the other surface of the substrate film,
The surface roughness of the surface of the transparent adhesive layer opposite to the side on which the base film is present is a base film with a transparent adhesive layer having a three-dimensional arithmetic average roughness Sa of 30 nm or less.   The base film with a transparent adhesive layer according to claim 1, wherein a release film is bonded to a surface of the transparent adhesive layer opposite to the side having the base film.   The base film has a first hard coat layer on one surface of the transparent plastic film, and the surface of the first hard coat layer opposite to the side on which the transparent plastic film is present, The base film with a transparent adhesive layer according to claim 1 or 2, which becomes one surface of the base film.   The base film has a second hard coat layer on the other surface of the transparent plastic film, and the surface of the second hard coat layer opposite to the side on which the transparent plastic film is present, The base film with a transparent adhesive layer according to any one of claims 1 to 3, which is the other surface of the base film.   The said adhesive is formed from the adhesive composition containing a (meth) acrylic acid ester copolymer, an isocyanate type crosslinking agent, and an organic tin compound, The transparent adhesion of any one of Claim 1 thru | or 4 Layered substrate film.   6. The base film with a transparent adhesive layer according to claim 5, wherein the pressure-sensitive adhesive contains 20 to 30 parts by weight of the organotin compound with respect to 100 parts by weight of the isocyanate-based crosslinking agent.   The base material with a transparent adhesive layer according to claim 5 or 6, wherein the (meth) acrylic acid ester copolymer is a copolymer having a (meth) acrylic acid alkyl monomer and a hydroxyl group-containing monomer as essential components. the film. A transparent conductive film with a transparent adhesive layer, wherein a transparent conductive thin film is provided on one side of the base film, and a transparent adhesive layer is laminated on the other side of the base film,
The base film having a transparent plastic film, the transparent conductive thin film provided on one side of the base film, and an adhesive applied to the other side of the base film were formed. Comprising the transparent adhesive layer,
The surface roughness of the surface of the transparent adhesive layer opposite to the side on which the substrate film is present is a transparent conductive film with a transparent adhesive layer having a three-dimensional arithmetic average roughness Sa of 30 nm or less.   The transparent conductive film with a transparent adhesive layer according to claim 8, wherein a release film is bonded to a surface of the transparent adhesive layer opposite to the side on which the base film is present.   A touch panel formed by using one or more transparent conductive films with a transparent adhesive layer according to claim 8.

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