JP2010108878A - Conductive film for touch panel, conductive film forming photosensitive material, conductive material, and conductive film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a conductive film for a touch panel having suitable conductivity, and improved touch panel characteristics by sufficiently reducing moire. <P>SOLUTION: The conductive film 10 for the touch panel includes a conductive layer 14 containing silver, which is formed by exposing and developing a silver salt emulsion layer 16 on a support 12. The silver salt emulsion layer 16 includes a silver application amount of 1.5-3.1 g/m<SP>2</SP>. The conductive layer 14 is formed in a mesh pattern having a pitch of 600-800 μm, and the conductive layer has a surface resistance of 200-800 Ω/sq. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a conductive film, and more particularly to a conductive film for a touch panel mounted on a touch panel, a photosensitive material for forming a conductive film, a conductive material, and a conductive film.

  In recent years, conductive films by various production methods have been studied (for example, see Patent Documents 1 to 5). In this, a silver halide emulsion layer is applied, and the silver halide emulsion layer is patterned so as to have a pattern shape having a conductive portion of silver for conductivity and an opening portion for ensuring transparency. There is a silver salt type conductive film manufactured as a conductive film by exposure (for example, see Patent Documents 6 to 11). This silver salt type conductive film is intended for use as an electromagnetic shield, and generally has a low surface resistance. In addition, the surface resistance is reduced by means such as plating. Yes.

JP 2000-13088 A Japanese Patent Laid-Open No. 10-340629 Japanese Patent Laid-Open No. 10-41682 Japanese Patent Publication No.42-23746 JP 2006-228649 A JP 2004-221564 A JP 2004-221565 A JP 2007-95408 A JP 2006-228469 A JP 2006-332459 A JP 2008-244067 A

  On the other hand, various uses of the conductive film have been studied, and the present inventors have studied focusing on the use as an electrode for a touch panel.

  An object of the present invention is to provide a conductive film for a touch panel, a conductive material for forming a conductive film, a conductive material, and a conductive film that have conductivity suitable as a conductive film for a touch panel, have sufficiently reduced moire, and have excellent touch panel characteristics. There is to do.

  As a result of intensive studies, the present inventors have found that the above problems can be solved by adjusting the amount of silver applied to the silver salt emulsion layer and adjusting the pitch, and have completed the present invention. It was.

That is, the following problems can be solved by the following invention.
[1] The conductive film for a touch panel according to the first aspect of the present invention is a conductive film for a touch panel having a conductive layer containing silver formed by exposing and developing a silver salt emulsion layer on a support. The coated silver amount of the salt emulsion layer is 1.5 to 3.1 g / m ² , the conductive layer is formed in a mesh pattern with a pitch of 600 μm to 800 μm, and the surface resistance is 200 to 800 ohm / sq. It is characterized by being.
[2] In the first invention, the silver / binder volume ratio of the silver salt emulsion layer is ¼ or more.
[3] In the first invention, the silver / binder volume ratio of the silver salt emulsion layer is ½ or more and 1 / 0.7 or less.
[4] In the first aspect of the present invention, the conductive layer has a line width of 5 to 10 μm.
[5] In the first aspect of the present invention, the transparent conductive layer further includes a conductive fine particle and a binder, and a mass ratio of the conductive fine particle to the binder (conductive fine particle / binder) is 1. / 3 to 2/1.
[6] Next, the conductive film-forming photosensitive material according to the second aspect of the present invention is the conductive film-forming photosensitive material having a silver salt emulsion layer, wherein the silver salt emulsion layer has a coating silver amount of 1.5-3. 0.1 g / m ² , further having a transparent conductive layer, the transparent conductive layer containing conductive fine particles and a binder, and a mass ratio of the conductive fine particles to the binder (conductive fine particles / binder) is 1. / 3 to 2/1.
[7] In the second aspect of the present invention, the silver salt emulsion layer contains the conductive fine particles and also serves as the transparent conductive layer, and the content of the conductive fine particles is 0.15 to 0.5 g / characterized in that it is a m ^2.
[8] In the second aspect of the present invention, the transparent conductive layer is located on an upper layer side of the silver salt emulsion layer, and the content of the conductive fine particles in the transparent conductive layer is 0.2 to 0.4 g / m. characterized in that it is a ^2.
[9] In the second invention, the transparent conductive layer is located on a lower layer side of the silver salt emulsion layer, and the content of the conductive fine particles in the transparent conductive layer is 0.15 to 0.5 g / m. characterized in that it is a ^2.
[10] In the second aspect of the present invention, when the conductive fine particles are spherical, the average particle diameter is 0.085 to 0.12 μm, and when the conductive fine particles are needle-shaped, the average axial length is long. The axis is 0.2 to 20 μm, and the minor axis is 0.01 to 0.02 μm.
[11] Next, the conductive material according to the third aspect of the present invention is obtained by subjecting the above-described photosensitive material for forming a conductive film according to the second aspect of the present invention to pattern exposure and development processing.
[12] Next, the conductive film according to the fourth aspect of the present invention is a conductive film having a conductive layer on a support, and the conductive layer or a layer different from the conductive layer is formed of conductive fine particles and a binder. And the mass ratio of the conductive fine particles to the binder (conductive fine particles / binder) is 1/3 to 2/1.

  As described above, the conductive film for a touch panel according to the present invention has conductivity suitable as a conductive film for a touch panel, moire is sufficiently reduced, and the touch panel characteristics are excellent. In the conductive film for a touch panel of the present invention, the surface resistance of the conductive layer is 1000 to 2500 ohm / sq. Therefore, the signal characteristics of the touch panel (particularly the capacitance type) are excellent, and noise is sufficiently reduced. Further, by setting the mesh pattern pitch to 1400 μm or less, the mesh pattern of the conductive layer becomes inconspicuous and the appearance is improved. Therefore, the display of characters, images, and the like through the touch panel is easy to see, and the visibility is excellent. In addition, the conductive film for touch panel of the present invention has excellent linearity at the time of pen input requiring accuracy, and variation in surface resistance is sufficiently reduced, so that excessive setting on the touch panel side, for example, linearity And excessive setting for correcting variation in resistance can be eliminated.

  Moreover, the photosensitive material for conductive film formation, the conductive material, and the conductive film according to the present invention can produce a conductive film for a touch panel having the above-described effects.

  Hereinafter, an embodiment in which a conductive film for a touch panel, a photosensitive material for forming a conductive film, a conductive material, and a conductive film according to the present invention are applied to, for example, a touch panel will be described with reference to FIGS.

As shown in FIG. 1, the conductive film 10 for a touch panel according to the present embodiment has two conductive layers 14 containing silver on a support 12. The two conductive layers 14 are laminated so as to face each other with the gap 23 interposed therebetween. These conductive layers 14 are formed by exposing and developing the silver salt emulsion layer 16, and the coated silver amount of the silver salt emulsion layer 16 is 1.5 to 3.1 g / m ² .

  Further, as shown in FIG. 2, the conductive layer 14 is formed in a mesh pattern 18 having a pitch Pa of 600 μm or more and 800 μm or less, and its surface resistance is 200 to 800 ohm / sq. It is. The conductive layer 14 is a layer including the conductive portion 20 formed in a mesh shape and the other opening 22. In some cases, a transparent conductive layer is provided on the conductive film 10 for the touch panel, but even in that case, the surface resistance of the transparent conductive layer 14 is larger than the surface resistance of the conductive layer 14. It becomes the surface resistance of the conductive film 10.

  Such a conductive film 10 for a touch panel according to this embodiment can be obtained by exposing and developing a mesh pattern 18 having a specific shape on a silver salt emulsion layer 16 which is a specific silver halide photosensitive material described in detail below. .

  Note that a transparent conductive layer (not shown) may be interposed between the support 12 and the conductive layer 14, or a transparent conductive layer may be interposed between the conductive layer 14 and the surface layer of the touch panel.

  Here, the configuration of each layer of the conductive film for touch panel 10 according to the present embodiment will be described in detail below.

[Support 12]
Examples of the support 12 used in the conductive film 10 for a touch panel according to the present embodiment include a plastic film, a plastic plate, and a glass plate.

  Examples of the raw material for the plastic film and plastic plate include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN); polyolefins such as polyethylene (PE), polypropylene (PP), polystyrene, and EVA; Resin; In addition, polycarbonate (PC), polyamide, polyimide, acrylic resin, triacetyl cellulose (TAC) and the like can be used.

  Examples of the support 12 include PET (melting point: 258 ° C.), PEN (melting point: 269 ° C.), PE (melting point: 135 ° C.), PP (melting point: 163 ° C.), polystyrene (melting point: 230 ° C.), polyvinyl chloride ( A plastic film or a plastic plate having a melting point of about 290 ° C. or less, such as polyvinylidene chloride (melting point: 212 ° C.) or TAC (melting point: 290 ° C.), is preferred, particularly light transmittance and workability. From these viewpoints, PET is preferable. Since the transparent conductive film such as the conductive film 10 for the touch panel is required to be transparent, the support 12 is preferably highly transparent.

[Silver Emulsion Layer 16]
The silver salt emulsion layer 16 which becomes the conductive layer 14 of the conductive film 10 for touch panel contains additives such as a solvent and a dye in addition to the silver salt and the binder.

  Examples of the silver salt used in the present embodiment include inorganic silver salts such as silver halide and organic silver salts such as silver acetate. In the present embodiment, it is preferable to use silver halide having excellent characteristics as an optical sensor.

The coating silver amount (silver salt coating amount) of the silver salt emulsion layer 16 is 1.5 to 3.1 g / m ² in terms of silver. When the amount of coated silver does not satisfy the above range, a desired surface resistance cannot be obtained when the conductive film 10 for touch panel is used.

  Examples of the binder used in the present embodiment include gelatin, polyvinyl alcohol (PVA), polyvinyl pyrrolidone (PVP), starch and other polysaccharides, cellulose and derivatives thereof, polyethylene oxide, polyvinyl amine, chitosan, polylysine, and polyacryl. Examples include acid, polyalginic acid, polyhyaluronic acid, carboxycellulose and the like. These have neutral, anionic, and cationic properties depending on the ionicity of the functional group.

  The content of the binder contained in the silver salt emulsion layer 16 of the present embodiment is not particularly limited, and can be appropriately determined as long as dispersibility and adhesion can be exhibited. The content of the binder in the silver salt emulsion layer 16 is preferably 1/4 or more and more preferably 1/2 or more in terms of Ag / binder volume ratio. The Ag / binder volume ratio is preferably 100/1 or less, and more preferably 50/1 or less. The Ag / binder volume ratio is more preferably 1/2 to 2/1. Most preferably, it is 1/2 to 0.7 / 1. By setting the Ag / binder volume ratio in the silver salt emulsion layer 16 within this range, even when the amount of coated silver is adjusted, variation in resistance value is suppressed, and the conductive film 10 for a touch panel having uniform surface resistance is obtained. Can do.

<Solvent>
The solvent used for forming the silver salt emulsion layer 16 is not particularly limited. For example, water, organic solvents (for example, alcohols such as methanol, ketones such as acetone, amides such as formamide, dimethyl, etc. Sulfoxides such as sulfoxide, esters such as ethyl acetate, ethers, etc.), ionic liquids, and mixed solvents thereof.

  Content of the solvent used for the silver salt emulsion layer 16 of this Embodiment is the range of 30-90 mass% with respect to the total mass of the silver salt, binder, etc. which are contained in the silver salt emulsion layer 16, 50 It is preferable to be in the range of ˜80 mass%.

<Other additives>
There are no particular restrictions on the various additives used in the present embodiment, and known ones can be preferably used.

[Other layer structure]
A protective layer (not shown) may be provided on the silver salt emulsion layer 16. In the present embodiment, the “protective layer” means a layer made of a binder such as gelatin or a high molecular polymer, on the silver salt emulsion layer 16 having photosensitivity in order to exhibit the effect of preventing scratches and improving mechanical properties. Formed. The thickness is preferably 0.2 μm or less. The coating method and forming method of the protective layer are not particularly limited, and a known coating method and forming method can be appropriately selected.

  An undercoat layer, for example, can be provided below the silver salt emulsion layer 16.

[Conductive polymer layer, conductive fine particle layer]
The conductive film 10 for a touch panel according to the present embodiment may further include a conductive polymer layer containing a conductive polymer such as PEDOT or a conductive fine particle layer containing conductive fine particles. The conductive polymer layer and the conductive fine particle layer have a size of 1.0 × 10 ⁷ ohm / sq. This is a highly conductive transparent conductive layer with low conductivity. By providing such a high-resistance transparent conductive layer, in-plane variation in surface resistance can be made uniform when the conductive film for touch panel 10 is formed, and linearity when pen input is performed is improved. Such a high-resistance transparent conductive layer may be in a position where it is electrically connected to the conductive layer 14 after the conductive film 10 for a touch panel is manufactured. For example, the high-resistance transparent conductive layer is a silver salt emulsion at the time of manufacture. It is preferably formed adjacent to the layer 16 (conductive layer 14).

  The conductive fine particle layer is the silver salt emulsion layer 16 itself, a layer formed at a position adjacent to the silver salt emulsion layer 16, a layer interposed between the silver salt emulsion layer 16 and the surface layer, or the surface layer itself. Alternatively, it is formed by containing conductive fine particles and a binder in a layer interposed between the support 12 and the silver salt emulsion layer 16. The mass ratio of the conductive fine particles and the binder (conductive fine particles / binder) is preferably 1/3 to 2/1, and more preferably 1/3 to 1/1. When the silver salt emulsion layer 16 itself contains conductive fine particles and a binder, the conductive fine particle layer is formed in the openings 22 of the mesh pattern 18 of the conductive layer 14. That is, the opening 22 of the mesh pattern 18 functions as a light transmission part in which conductive fine particles are dispersed.

  When the conductive fine particle layer is formed at a position different from the silver salt emulsion layer 16, the conductive fine particle layer is preferably formed at a position adjacent to the silver salt emulsion layer 16. Preferably, it is formed between the supports 12. When the conductive fine particle layer is interposed between the silver salt emulsion layer 16 and the surface layer, or when it is the surface layer itself, the conductive fine particle reacts in the manufacturing process of the conductive film for touch panel 10 and is used for the touch panel. There is a possibility that the transparency of the conductive film 10 may be reduced.

<Conductive fine particles and binder>
The conductive fine particles include metal oxides such as SnO ₂ , ZnO, TiO ₂ , Al ₂ O ₃ , In ₂ O ₃ , MgO, BaO and MoO ₃ , and composite oxides thereof (an oxidation containing two or more kinds of metal ions). And metal oxide particles further containing different atoms in these metal oxides. As the metal oxide, SnO ₂ , nO, TiO ₂ , Al ₂ O ₃ , In ₂ O ₃ and MgO are preferable, and SnO ₂ is particularly preferable.

  There is no restriction | limiting in particular about the shape of the electroconductive fine particles used for this Embodiment, A granular form, needle shape, etc. are mentioned. The size of the spherical particles is preferably 0.085 to 0.12 μm. In the case of needles, the average axial length is preferably 0.2-20 μm in the long axis and 0.01-0.02 μm in the short axis.

When the conductive fine particles and the binder are contained in the silver salt emulsion layer 16, the coating amount of the conductive fine particles is preferably 0.15 to 0.5 / m ² . When the conductive fine particle layer is positioned above the silver salt emulsion layer 16, the coating amount of the conductive fine particles is preferably 0.2 to 0.4 g / m ² . When the conductive fine particle layer is positioned on the lower layer side than the silver salt emulsion layer 16, the coating amount of the conductive fine particles is preferably 0.15 to 0.5 g / m ² .

  In the conductive fine particle layer, a binder is additionally used for the purpose of bringing the conductive fine particles into close contact with the support 12. As such a binder, it is preferable to use a water-soluble polymer.

  Examples of the binder include polysaccharides such as gelatin, carrageenan, polyvinyl alcohol (PVA), polyvinyl pyrrolidone (PVP), starch, cellulose and derivatives thereof, polyethylene oxide, polysaccharides, polyvinylamine, chitosan, polylysine, and polyacrylic acid. , Polyalginic acid, polyhyaluronic acid, carboxycellulose, gum arabic, sodium alginate and the like. These have neutral, anionic, and cationic properties depending on the ionicity of the functional group.

  In addition to lime-processed gelatin, acid-processed gelatin may be used as gelatin. Hydrolyzate of gelatin, enzyme-decomposed gelatin, other gelatin modified with amino group and carboxyl group (phthalated gelatin, acetylated gelatin) Can be used.

[Touch panel conductive film 10]
The conductive film 10 for a touch panel according to the present embodiment can be obtained by pattern-exposing the silver salt emulsion layer 16 formed on the support 12 in a mesh shape and developing it.

  In the present embodiment, the mesh pattern 18 formed by the pattern exposure / development process is a linear lattice pattern having a mesh shape and substantially straight lines as shown in FIG. 2, as shown in FIG. There is a wavy grid pattern in which the conductive portion 20 between the intersecting portions 24 has at least one curve. In the present embodiment, the pitch Pa (the total of the line width Wa of the conductive portion 20 and the width Wb of the opening 22) of the mesh pattern 18 of the conductive layer 14 is preferably 600 μm or more and 800 μm or less.

  In the present embodiment, a transparent conductive layer having a higher resistance may be formed by further applying a conductive polymer on the conductive layer 14.

[exposure]
A method of exposing the silver salt emulsion layer 16 in a pattern may be performed by surface exposure using a photomask or by scanning exposure using a laser beam. At this time, refractive exposure using a lens or reflection exposure using a reflecting mirror may be used, and exposure methods such as contact exposure, proximity exposure, reduced projection exposure, and reflection projection exposure can be used.

[Development processing]
The silver salt emulsion layer 16 is further subjected to development processing after pattern exposure as described above. The development processing can be performed by a normal development processing technique used for silver salt photographic film, photographic paper, printing plate-making film, photomask emulsion mask, and the like.

  In the present embodiment, by performing the above-described pattern exposure and development process, a mesh pattern-shaped conductive portion 20 (metal silver portion) is formed in the exposed portion, and an opening portion 22 (light-transmitting property) in the unexposed portion. Part) is formed.

  The development processing on the silver salt emulsion layer 16 can include a fixing processing performed for the purpose of removing and stabilizing the silver salt in an unexposed portion. The fixing process for the silver salt emulsion layer 16 may be a fixing process technique used for silver salt photographic film, photographic paper, printing plate making film, emulsion mask for photomask, and the like.

  The conductive layer 14 of the conductive film 10 for the touch panel according to the present embodiment thus obtained has an opening 22 (from which the silver salt is removed when the silver salt emulsion layer 16 contains conductive fine particles. The conductive fine particles are dispersed in the light transmitting portion), and a transparent conductive layer having a higher resistance than that of the conductive portion 20 (metal silver portion) is formed.

  Further, by forming the conductive fine particle layer at a position other than the silver salt emulsion layer 16, the portion of the conductive fine particle layer corresponding to the opening 22 of the conductive layer 14 is the same as described above. It will function as a dispersed light transmission part.

  In addition, in the manufacturing method of the electrically conductive film 10 for touchscreens concerning this Embodiment, processes, such as plating, are unnecessary. This is because in the method for manufacturing the conductive film 10 for the touch panel according to the present embodiment, a desired surface resistance can be obtained by adjusting the coating silver amount and the silver / binder ratio of the silver salt emulsion layer 16. In addition, you may perform a calendar process etc. as needed.

(Hardening after development)
After the silver salt emulsion layer 16 is developed, it is preferably immersed in a hardener to perform the hardening process. Examples of the hardener include dialdehydes such as glutaraldehyde, adipaldehyde, 2,3-dihydroxy-1,4-dioxane, and those described in JP-A-2-141279 such as boric acid. .

  As described above, the silver salt emulsion layer 16 and the conductive material of the present embodiment described above can be used by appropriately combining the techniques disclosed in the publicly known documents listed below.

  JP 2004-221564 A, JP 2004-221565 A, JP 2007-200902 A, JP 2006-352073 A, International Publication No. 2006/001461 pamphlet, JP 2007-129205 A, JP 2007-235115, JP 2007-207987, JP 2006-012935, JP 2006-0110795, JP 2006-228469, JP 2006-332459, JP 2007. JP-A-207987, JP-A-2007-226215, WO2006 / 088059, JP-A-2006-261315, JP-A-2007-072171, JP-A-2007-102200, JP-A-2006. 228473 Gazette, JP-A-2006-26997, JP-A-2006-267635, JP-A-2006-267627, pamphlet of International Publication No. 2006/098333, JP-A-2006-324203, JP-A-2006-228478 JP 2006-228836 A, JP 2006-228480 A, WO 2006/098336 pamphlet, WO 2006/098338 pamphlet, JP 2007-009326 A, and JP 2006-336057 A. JP, 2006-339287, JP, 2006-336090, JP, 2006-336099, JP, 2007-039738, JP, 2007-039739, JP, 2007-039740, Open No. 007-002296, JP 2007-088886, JP 2007-092146, JP 2007-162118, JP 2007-200902, JP 2007-197809, JP 2007-. No. 270353, No. 2007-308761, No. 2006-286410, No. 2006-283133, No. 2006-283137, No. 2006-348351, No. 2007-270321. JP, 2007-270322, WO 2006/098335 pamphlet, JP 2007-088218, JP 2007-201378, JP 2007-335729, WO 2006/098334. Pamphlet JP, 2007-134439, JP, 2007-149760, JP, 2007-208133, JP, 2007-178915, JP, 2007-334325, JP, 2007-310091, JP 2007-311646, JP 2007-013130, JP 2006-339526, JP 2007-116137, JP 2007-088219, JP 2007-207883, JP 2007. JP-A-207893, JP-A-2007-207910, JP-A-2007-013130, WO 2007/001008, JP-A 2005-302508, JP-A-2005-197234.

[Undercoat layer]
In order to prevent the conductive layer 14 from peeling from the support 12, it is preferable to provide an undercoat layer on the support 12. As the material for the undercoat layer, acrylic acid ester copolymer, polyvinylidene chloride, styrene-butadiene rubber, polyester, and the like can be used. The thickness of the undercoat layer is preferably 0.05 to 0.5 μm.

<Touch panel>
The conductive film 10 for a touch panel according to the present embodiment is suitable for use in, for example, a resistive film type touch panel.

  A resistive film type touch panel is generated between two conductive layers 14 because the conductive layers 14 of the part are in contact with each other when a fingertip is pressed against the surface of the touch panel, and current flows between the two conductive layers 14. The coordinates of the fingertip are obtained by detecting the voltage to be applied.

  In particular, the conductive film 10 for a touch panel according to the present embodiment has a surface resistance of 200 to 800 ohm / sq. Therefore, the signal characteristics of the resistive touch panel are excellent, and noise can be sufficiently reduced. This makes it possible to realize position detection with high accuracy and high response speed.

  Further, since the pitch Pa of the mesh pattern 18 of the conductive layer 14 is 600 μm or more, moire is sufficiently reduced, and since the pitch Pa is 800 μm or less, the mesh pattern 18 of the conductive layer 14 becomes inconspicuous and looks Becomes better. Therefore, it is easy to see the display of characters and images through the touch panel, and a touch panel with excellent visibility can be provided.

  Furthermore, since the transparent conductive layer such as the conductive fine particle layer or the conductive polymer layer is formed at a position different from the opening 22 or the conductive layer 14 of the conductive layer 14, the entire surface of the conductive film 10 for the touch panel has conductivity. It is possible to perform coordinate detection that faithfully follows pen input, and for example, it is possible to improve linearity when pen input is performed.

  In addition, since an undercoat layer is formed on the support 12 and the silver salt emulsion layer 16 is further developed, it is dipped in a hardener and hardened, so that the slidability of the touch panel is improved. Even when the pen slides with respect to the vicinity of the terminal, the conductive layer is not disconnected, and a situation in which the surface resistance is locally increased can be avoided.

  Hereinafter, the present invention will be described in detail based on examples, but the present invention is not limited thereto.

[Example 1]: See Table 1 (Preparation of Emulsion A)
・ 1 liquid:
750 ml of water
Gelatin (phthalated gelatin) 8g
Sodium chloride 3g
1,3-Dimethylimidazolidine-2-thione 20mg
Sodium benzenethiosulfonate 10mg
Citric acid 0.7g
・ Two liquids 300ml
150 g silver nitrate
・ 3 liquid water 300ml
Sodium chloride 38g
Potassium bromide 32g
Hexachloroiridium (III) potassium salt
(0.005% KCl 20% aqueous solution) 5 ml
Ammonium hexachlororhodate
(0.001% NaCl 20% aqueous solution) 7 ml

  Potassium hexachloroiridium (III) (0.005% KCl 20% aqueous solution) and ammonium hexachlororhodate (0.001% NaCl 20% aqueous solution) used in the three liquids were mixed with their respective complex powders, KCl 20% aqueous solution and NaCl 20%, respectively. It was dissolved in an aqueous solution and prepared by heating at 40 ° C. for 120 minutes.

  To 1 liquid maintained at 38 ° C. and pH 4.5, 90% of the 2 and 3 liquids were simultaneously added over 20 minutes while stirring to form 0.16 μm core particles. Subsequently, the following 4th and 5th liquids were added over 8 minutes, and the remaining 10% of the 2nd and 3rd liquids were added over 2 minutes to grow to 0.21 μm. Further, 0.15 g of potassium iodide was added and ripened for 5 minutes to complete grain formation.

・ 4 liquid water 100ml
Silver nitrate 50g
・ 5 liquid 100ml
Sodium chloride 13g
Potassium bromide 11g
Yellow blood salt 5mg

  Then, it washed with water by the flocculation method according to a conventional method. Specifically, the temperature was lowered to 35 ° C., and the pH was lowered using sulfuric acid until the silver halide precipitated (the pH was in the range of 3.6 ± 0.2).

  Next, about 3 liters of the supernatant was removed (first water washing). Further, 3 liters of distilled water was added, and sulfuric acid was added until the silver halide settled. Again, 3 liters of the supernatant was removed (second water wash). The same operation as the second water washing was further repeated once (third water washing) to complete the water washing / desalting process.

The emulsion after washing and desalting is adjusted to pH 6.4 and pAg 7.5, and 10 mg of sodium benzenethiosulfonate, 3 mg of sodium benzenethiosulfinate, 15 mg of sodium thiosulfate and 10 mg of chloroauric acid are added. And 1,3,3a, 7-tetraazaindene (100 mg) as a stabilizer and 100 mg of proxel (trade name, manufactured by ICI Co., Ltd.) as a preservative were added. Finally, a silver iodochlorobromide cubic grain emulsion containing 70 mol% of silver chloride and 0.08 mol% of silver iodide and having an average grain diameter of 0.22 μm and a coefficient of variation of 9% was obtained. The final emulsion was pH = 6.4, pAg = 7.5, conductivity = 40 μS / m, density = 1.2 × 10 ³ kg / m ³ , and viscosity = 60 mPa · s.

(Preparation of coating solution)
The emulsion A was subjected to spectral sensitization by adding sensitizing dye (SD-1) 5.7 × 10 ⁻⁴ mol / mol Ag. Further KBr3.4 × 10 ^-4 mol / mol Ag, Compound (Cpd-3) 8.0 × 10 -4 mol / mol Ag was added and mixed well.

Then, 1,3,3a, 7-tetraazaindene 1.2 × 10 ⁻⁴ mol / mol Ag, hydroquinone 1.2 × 10 ⁻² mol / mol Ag, citric acid 3.0 × 10 ⁻⁴ mol / mol Ag 2,4-dichloro-6-hydroxy-1,3,5-triazine sodium salt at 90 mg / m ² , colloidal silica having a particle size of 10 μm of 15 wt% based on gelatin, and aqueous latex (aqL-6) at 50 mg / m ² m ² , 100 mg / m ^{2 of} polyethyl acrylate latex, 100 mg of latex copolymer (mass ratio 88: 5: 7) of methyl acrylate, 2-acrylamido-2-methylpropanesulfonic acid sodium salt and 2-acetoxyethyl methacrylate / m ^2, the core-shell latex core: styrene / butadiene copolymer (weight ratio 37/63), shell: styrene / 2-acetoxyethyl acrylate (weight ratio 84/16, core / shell ratio = 50/50) was added 100 mg / m ^2, 4 wt% of the compound to gelatin (Cpd-7), coated with citric acid The liquid pH was adjusted to 5.6.

(Undercoat layer)
An undercoat layer was provided on the support as described below (polyethylene terephthalate (PET) (thickness: 100 μm) was used as the support. The surface was hydrophilized in advance). As an undercoat layer of a silver halide emulsion layer formed according to the following description, gelatin was provided at 0.195 g / m ² . This undercoat layer also serves as a transparent conductive layer.
・ 1 liquid:
410ml water
11.4g of gelatin
Sb-doped tin oxide (trade name SN100P, manufactured by Ishihara Sangyo Co., Ltd.) 19.5g
A surface active agent known in the photographic art may be added to the undercoat layer.

(Silver halide emulsion layer)
With emulsion A, it was coated an emulsion layer coating liquid prepared as described above so that on Ag1.5g / m ^2, gelatin 0.21 g / m ² for the undercoat layer. That is, coating was performed so that the ratio of Ag to gelatin (binder) was 1 / 1.1 (volume ratio).

(Protective layer)
A protective layer was provided on the silver halide emulsion layer.
・ 1 liquid:
985 ml of water
15g gelatin
In addition, surfactants, preservatives, and ph regulators known in the photographic art were added as appropriate.

The coated product thus obtained is dried and used as sample A. The conductive fine particles are applied to the transparent conductive layer (undercoat layer) with conductive fine particles of 0.3354 g / m ² and a conductive fine particle / binder ratio of 1.71 / 1 (mass ratio). In order to investigate the resistance (surface resistance of the opening) of the conductive fine particles alone, this sample A was not subjected to exposure / development processing, but only fixed, and the surface resistance was measured by removing silver halide. .5 × 10 ⁹ ohm / sq. Met.

(Exposure and development processing)
Next, a photomask having a grid-like space with a grid-like photomask line / space = 692 μm / 8 μm (pitch 700 μm) capable of giving a developed silver image of line / space = 8 μm / 692 μm to the sample A prepared above. Then, it is exposed using parallel light using a high-pressure mercury lamp as a light source, developed with the following developer, and further developed with a fixer (trade name: N3X-R for CN16X: manufactured by Fujifilm). After that, rinsing with pure water was performed to obtain a conductive film for a touch panel according to Example 1.

[Developer composition]
The following compounds are contained in 1 liter of developer.
Hydroquinone 0.037mol / L
N-methylaminophenol 0.016 mol / L
Sodium metaborate 0.140 mol / L
Sodium hydroxide 0.360 mol / L
Sodium bromide 0.031 mol / L
Potassium metabisulfite 0.187 mol / L

[Hardening after development]
After development, the film was dipped in a glutaraldehyde aqueous solution and subjected to hardening.

[Example 2]: See Table 1 The conductive film for a touch panel according to Example 2 is the same as Example 1 except that the coating solution of the silver halide emulsion layer is applied so as to be Ag 1.7 g / m ^2. A membrane was obtained.

[Example 3]: See Table 1 The conductive film for a touch panel according to Example 3 is the same as Example 1 except that the coating solution of the silver halide emulsion layer is applied so as to be Ag 1.9 g / m ^2. A membrane was obtained.

[Example 4]: See Table 1 The conductive film for a touch panel according to Example 4 is the same as Example 1 except that the coating solution for the silver halide emulsion layer is applied to have an Ag of 2.1 g / m ^2. A membrane was obtained.

[Example 5]: See Table 1 The conductive film for a touch panel according to Example 5 is the same as Example 1 except that the coating solution of the silver halide emulsion layer is applied so as to be Ag 2.3 g / m ^2. A membrane was obtained.

[Example 6]: See Table 1 The conductive film for a touch panel according to Example 6 is the same as Example 1 except that the coating solution of the silver halide emulsion layer is applied to have an Ag of 2.5 g / m ^2. A membrane was obtained.

[Example 7]: See Table 1. The conductive film for a touch panel according to Example 7 is the same as Example 1 except that the coating solution of the silver halide emulsion layer is applied so as to be Ag 2.7 g / m ^2. A membrane was obtained.

[Example 8]: See Table 2 The conductive film for a touch panel according to Example 8 is the same as Example 1 except that the coating solution of the silver halide emulsion layer is applied so as to be Ag 2.9 g / m ^2. A membrane was obtained.

[Example 9]: See Table 2. The conductive film for a touch panel according to Example 9 is the same as Example 1 except that the coating solution of the silver halide emulsion layer is applied so as to be Ag 3.1 g / m ^2. A membrane was obtained.

[Example 10]: Refer to Table 2. A point where a silver halide emulsion layer coating solution was applied so as to have an Ag of 2.1 g / m ² , and a lattice-like photo capable of giving a developed silver image of line / space = 8 μm / 592 μm A conductive film for a touch panel according to Example 10 is obtained in the same manner as in Example 1 except that the mask line / space = 592 μm / 8 μm (pitch 600 μm) is exposed through a photomask having a grid-like space. It was.

[Example 11]: Refer to Table 2. The point where the coating solution of the silver halide emulsion layer was applied so as to be Ag 2.1 g / m ^2, and the lattice-like photo capable of giving a developed silver image of line / space = 8 μm / 792 μm A conductive film for a touch panel according to Example 11 is obtained in the same manner as in Example 1 except that the mask line / space = 792 μm / 8 μm (pitch 800 μm) is exposed through a photomask having a grid-like space. It was.

[Example 12]: See Table 2. Example except that the coating solution of the silver halide emulsion layer was applied to Ag 2.1 g / m ² and the support was not surface hydrophilized. In the same manner as in Example 1, a conductive film for a touch panel according to Example 12 was obtained.

[Example 13]: See Table 2 Other than the point that the coating solution of the silver halide emulsion layer was applied so as to be Ag 2.1 g / m ² , and the film hardening treatment by immersion in glutaraldehyde aqueous solution was not performed after the development processing. Obtained the conductive film for touchscreens which concerns on Example 13 like Example 1. FIG.

[Comparative Example 1]: See Table 3. The conductive film for a touch panel according to Comparative Example 1 is the same as Example 1 except that the coating solution of the silver halide emulsion layer is applied so as to be Ag 1.4 g / m ^2. A membrane was obtained.

[Comparative Example 2]: See Table 3 The conductive film for a touch panel according to Comparative Example 2 is the same as Example 1 except that the coating solution of the silver halide emulsion layer is applied so as to have an Ag of 3.2 g / m ^2. A membrane was obtained.

[Comparative Example 3]: Refer to Table 3. Lattice-shaped photo that can give a developed silver image of line / space = 8 μm / 492 μm, in which the silver halide emulsion layer coating solution was applied to Ag 2.1 g / m ^2. A conductive film for a touch panel according to Comparative Example 3 is obtained in the same manner as in Example 1 except that the mask line / space is 492 μm / 8 μm (pitch: 500 μm), and is exposed through a photomask having a grid-like space. It was.

[Comparative Example 4]: Refer to Table 3. A point where a silver halide emulsion layer coating solution was applied to give an Ag of 2.1 g / m ² , a line / space = 8 μm / 892 μm lattice-like photo capable of giving a developed silver image A conductive film for a touch panel according to Comparative Example 4 is obtained in the same manner as in Example 1 except that the mask line / space = 892 μm / 8 μm (pitch 900 μm) is exposed through a photomask in which the space is a grid. It was.

[Comparative Example 5]
Lattice-shaped photomask lines / spaces = 592 μm / 8 μm (line / space = 8 μm / 592 μm) that can give a developed silver image at a point where the silver halide emulsion layer coating solution was applied to Ag 2.1 g / m ^2. The conductive film for a touch panel according to Comparative Example 5 was prepared in the same manner as in Example 1 except that the space was exposed through a photomask having a pitch of 600 μm and the transparent conductive layer was not formed. Obtained.

[Comparative Example 6]
For the touch panel according to Comparative Example 6, except that the silver halide emulsion layer coating solution was applied to Ag 2.1 g / m ² and the transparent conductive layer was not formed. A conductive film was obtained.

[Comparative Example 7]
A point where the silver halide emulsion layer coating solution was applied to have an Ag of 2.1 g / m ² , and a lattice-like photomask line / space = 792 μm / 8 μm (line / space = 8 μm / 792 μm). A conductive film for a touch panel according to Comparative Example 7 was prepared in the same manner as in Example 1 except that the exposure was performed through a photomask having a pitch of 800 μm) and the transparent conductive layer was not formed. Obtained.

[Evaluation]
(Measurement of surface resistance and evaluation of variation in surface resistance)
The surface resistance of the conductive layer 14 was measured with a non-contact resistance meter 717B (H) manufactured by Coper Electronics Co., Ltd. The surface resistance of the opening 22 was measured with a digital super high resistance (SR meter) R8340A manufactured by ADVANTEST.

(Evaluation of moire)
A Matsushita Electric PDP (TH-42PX300) from which the electromagnetic shielding film on the surface has been removed is prepared, and a rotating disk for installing the conductive film for the touch panel prepared thereon is disposed thereon. The turntable is made of glass having a thickness of 5 mm and imitates a PDP front plate. Furthermore, an angle scale is provided so that the bias angle of the installed conductive film for touch panel can be seen. The PDP is powered on, and the PDP HDMI terminal is connected to the pattern generator (ASTROVG828D). The white color signal with the maximum output value is sent from the pattern generator to the PDP. Fix the conductive film for touch panel on the turntable with tape so that it does not bend. The room was set as a dark room, and the rotating disk was rotated between a bias angle of −45 ° and + 45 °, and visual observation and evaluation of moire were performed. Visibility of moire is observed at a distance of 1.5 m from the front of the PDP, ◎ when moire does not appear, ◎ when moire is seen only at a level where there is no problem, ○ when moire appears. Each bias angle was evaluated as x. The overall score is ○ 5 when the angle range that is ◎ is 15 ° or more, ○ 4 when the angle range that is ◎ is less than 15 °, 10 ° or more, and when the angle range that is ◎ is less than 10 ° When there is no angle range that is Δ3 and ◎ and the angle range that is × is less than 10 °, Δ2 is that there is no angle range that is Δ2 and ◎ and there is an angle range that is × 10 ° or more.

(Evaluation of appearance)
The display of the PDP used in the moire evaluation was gradually changed from black to white, and when viewed with the naked eye, the gray gradation at the time when the mesh pattern of the conductive film for the touch panel was conspicuous was normalized and evaluated. . At this time, when the mesh pattern is conspicuous with a gradation close to black, it is evaluated as “× 1”, when it is conspicuous with a gradation close to white, or when it is not conspicuous at all, “○ 5” is evaluated. When it was conspicuous in the key, it was assigned in the order of “◯ 4”, “Δ3”, “Δ2” in order from the side closer to white toward black.

(Evaluation of linearity)
A square with a side of 5 cm was input to the touch panel with a pen, and it was visually confirmed whether or not there was a break or disorder (fine irregularities) on each side of the square drawn. And, when there is no disconnection or disorder on all four sides, ○ 5, when there is a disconnection or disorder on any one side, ○ 4, when any two sides have disconnection or disorder, Δ3, either 3 When the side was disconnected or disturbed, it was evaluated as x2, and when all the sides were disconnected or disordered, it was evaluated as x1.

(Slidability evaluation)
One end of the long conductive film for a touch panel was fixed, and a 0.5 mm portion of the conductive film for the touch panel was slid with a 0.8 R polyacetal nib. A load of 500 g was applied to the pen tip, the sliding speed was 5 times / second, and the sliding length was 20 m. After sliding with the pen tip, the surface resistance of the conductive film for the touch panel was measured with the above-mentioned Lorester GP (model number MCP-T610) series 4-probe probe (ASP), and the rate of increase with respect to the initial surface resistance was observed. When the rate of increase was less than 1.5, it was evaluated as ◯, when it was 1.5 or more and less than 2.0, Δ, and when it was 2,000 or more, it was evaluated as x.

  In Examples 1 to 13, the surface resistance is 200 to 800 ohm / sq. It can be seen that it is a conductive film for a touch panel suitable for use in, for example, a resistive film type touch panel. Moreover, since the pitch Pa of the mesh pattern 18 of the conductive layer 14 is 600 μm or more, it can be seen that moire is sufficiently reduced. Further, since the pitch Pa of the mesh pattern 18 is 800 μm or less, the mesh pattern 18 of the conductive layer 14 becomes inconspicuous, and the appearance is good. Therefore, in particular, the first to thirteenth embodiments make it easy to see the display of characters and images through the touch panel, and can provide a touch panel with excellent visibility.

  Furthermore, since Examples 1-13 formed the transparent conductive layer in which the electroconductive fine particles were disperse | distributed separately from the conductive layer 14, it turns out that the linearity at the time of pen input is improving. In Examples 1 to 11, it was found that the slidability was improved because an undercoat layer was formed on the support and further the film hardening treatment was performed. Since Example 12 did not form an undercoat layer, the evaluation was x. Moreover, since Example 13 did not perform a hardening process, evaluation was (triangle | delta).

  On the other hand, Comparative Examples 1 and 2 both have a surface resistance of 200 to 800 ohm / sq. Deviated from the scope. In Comparative Example 3, since the pitch was 500 μm (less than 600 μm), moire was conspicuous and the evaluation was × 2. On the contrary, in Comparative Example 4, since the pitch was 900 μm (exceeding 800 μm), the mesh pattern was conspicuous and the evaluation was × 2. Since Comparative Examples 5-7 did not form a transparent conductive layer, the linearity was poor and the evaluations were both x1.

  In addition, the conductive film for touch panels and the manufacturing method thereof according to the present invention are not limited to the above-described embodiments, and it is needless to say that various configurations can be adopted without departing from the gist of the present invention.

It is sectional drawing which abbreviate | omits and shows the electrically conductive film for touchscreens which concerns on this Embodiment. It is a top view which shows an example (linear lattice pattern) of the mesh pattern of a conductive layer. It is a top view which shows the other example (a wavy lattice pattern) of the mesh pattern of a conductive layer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Conductive film 12 for touchscreen ... Support body 14 ... Conductive layer 16 ... Silver salt emulsion layer 18 ... Mesh pattern 20 ... Conductive part 22 ... Opening part Pa ... Pitch

Claims (12)

A conductive film for a touch panel having a conductive layer containing silver formed by exposing and developing a silver salt emulsion layer on a support,
Coated silver amount of the silver salt emulsion layer is 1.5~3.1g / m ^2,
The conductive layer is formed in a mesh pattern having a pitch of 600 μm to 800 μm,
The surface resistance is 200 to 800 ohm / sq. A conductive film for a touch panel, characterized in that The conductive film for a touch panel according to claim 1,
A conductive film for a touch panel, wherein the silver / binder volume ratio of the silver salt emulsion layer is 1/4 or more. The conductive film for a touch panel according to claim 1,
The conductive film for a touch panel, wherein the silver / binder volume ratio of the silver salt emulsion layer is from 1/2 to 1 / 0.7. In the electrically conductive film for touchscreens of any one of Claims 1-3,
A conductive film for a touch panel, wherein the conductive layer has a line width of 5 to 10 μm. In the electrically conductive film for touchscreens of any one of Claims 1-4,
Furthermore, a transparent conductive layer is provided,
The transparent conductive layer contains conductive fine particles and a binder, and a mass ratio of the conductive fine particles to the binder (conductive fine particles / binder) is 1/3 to 2/1. . In a photosensitive material for forming a conductive film having a silver salt emulsion layer,
The coating silver amount of the silver salt emulsion layer is 1.5 to 3.1 g / m ² ,
Furthermore, it has a transparent conductive layer,
The transparent conductive layer contains conductive fine particles and a binder, and a mass ratio of the conductive fine particles to the binder (conductive fine particles / binder) is 1/3 to 2/1. Photosensitive material. In the photosensitive material for electrically conductive film formation of Claim 6,
The silver salt emulsion layer contains the conductive fine particles, and also serves as the transparent conductive layer,
Content of the said electroconductive fine particles is 0.15-0.5 g / m < ² >, The photosensitive material for electrically conductive film formation characterized by the above-mentioned. In the photosensitive material for electrically conductive film formation of Claim 6,
The transparent conductive layer is located on the upper side of the silver salt emulsion layer,
Content of the said electroconductive fine particles of the said transparent conductive layer is 0.2-0.4g / m < ² >, The photosensitive material for electrically conductive film formation characterized by the above-mentioned. In the photosensitive material for electrically conductive film formation of Claim 6,
The transparent conductive layer is located on the lower layer side of the silver salt emulsion layer,
The content of the conductive fine particles of the transparent conductive layer, the conductive film forming photosensitive material, which is a 0.15~0.5g / m ^2. In the photosensitive material for electrically conductive film formation of any one of Claims 7-9,
When the conductive fine particles are spherical, the average particle size is 0.085 to 0.12 μm,
When the conductive fine particles are needle-shaped, an average axis length is 0.2 to 20 μm in the major axis and 0.01 to 0.02 μm in the minor axis, and a photosensitive material for forming a conductive film, characterized in that:   A conductive material obtained by subjecting the photosensitive material for forming a conductive film according to claim 6 to pattern exposure and development treatment. A conductive film having a conductive layer on a support,
The conductive layer or another layer different from the conductive layer contains conductive fine particles and a binder,
A conductive film having a mass ratio of the conductive fine particles to the binder (conductive fine particles / binder) of 1/3 to 2/1.

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