JP4630683B2 - Electrode printing method and electrode plate provided with the electrode - Google Patents

Description

  The present invention relates to an electrode printing method and an electrode substrate provided with the electrode, and more specifically, an apparatus for forming a fine electrode pattern from a conductive nanometal powder on a substrate using a reverse offset printing method, an image forming apparatus This is suitably used when forming the TFT electrode.

2. Description of the Related Art Conventionally, many electrode substrates that are mounted on electrical / electronic components such as image forming apparatuses are mainly formed by printing a circuit on a substrate by a photographic technique called a photolithography method. In the photolithographic method, a metal film having good conductivity is formed in advance on the entire surface of the substrate by sputtering or the like, a photosensitive resin is formed thereon, exposed to light and developed to form a pattern, and etching is performed. Thus, unnecessary portions of the metal film are washed away to form the required electrodes.
The photolithography method is excellent in that a very fine pattern can be formed with high accuracy, but the process is very complicated and not only a series of management is difficult, but also a process such as exposure, development, and drying is performed. A series of production lines are very expensive because they require high precision and cleanliness of production equipment. In addition, in order to obtain a sputtered film having good conductivity, a high-temperature treatment exceeding 200 ° C. is required as sputtering conditions, which increases the thermal burden on the substrate and causes distortion and deterioration of the substrate.

  As a printing method not using the photolithographic method, in Japanese Patent Laid-Open No. 11-58921 (Patent Document 1), a resin is entirely applied to a blanket surface provided with a silicone rubber on the surface layer portion, and a predetermined amount is applied to the coated surface An image forming method is disclosed in which a convex portion of a relief printing plate formed in a shape is pressed to partially remove the resin on the blanket, and the remaining resin is transferred to a substrate.

  In the above method, it is necessary to apply a resin to the entire surface of the silicone rubber having a very high water repellency (very poor wettability), and the surface of the silicone rubber has no unevenness for the purpose of improving the printing shape. Since it is designed to be 1 μm or less, there is a problem that the ink is repelled on the surface of the silicone rubber and the resin cannot be uniformly applied. In addition, when continuous printing is performed, the surface of the silicone rubber swells, so that the wettability of the surface changes, thereby changing the applicability, and there is a problem that a stable application surface cannot be formed. Furthermore, when the drying property of the resin is poor, the transferability to the printing medium is deteriorated, and there is a problem that it is piled.

  Furthermore, when a metal powder is mixed with a resin to form an electrode by printing, the resin has a very high viscosity, and it is difficult to adjust to a low viscosity (50 to 500 cps) necessary for offset printing. As a result, there is no choice but to take a method of forming a pattern with a high-viscosity offset printing ink and then forming a metal film on it using ink containing metal powder. This also causes a rise in costs.

JP-A-11-58921

  The present invention has been made in view of the above problems, and in the case where an electrode pattern is formed by a reverse offset printing method similar to Patent Document 1, colloidal ink containing conductive nano metal powder is stabilized in blanket silicone rubber. Electrode printing method and electrode plate which can be applied to the substrate and can be heated at a low temperature after being transferred to the substrate, and can form an electrode pattern with excellent conductivity and high accuracy. It is an issue to provide.

In order to solve the above problems, the present invention provides:
On the surface of a blanket made of smooth silicone rubber with a hydrophilic treatment on the surface,
A conductive nano metal powder having an average particle size of 0.1 to 100 nm is dispersed in the ink component, and a colloidal ink whose viscosity is adjusted to 5 to 50 cps is applied, and then,
Removing the ink of unnecessary portions from the blanket surface by pressing an intaglio or letterpress having a predetermined pattern against the application surface;
The ink left in the required pattern on the surface of the blanket is transferred to the substrate,
Then, the printed material is heated, and the conductive nano metal powder in the transferred ink is fused,
Then, an electrode printing method is provided, in which an electrode is formed by curing and fixing a fused conductive nano metal powder on a substrate to be printed.

In the present invention, as described above, the colloidal ink to be applied to the silicone rubber surface of a blanket (hereinafter referred to as silicone blanket) having silicone rubber on the surface layer portion is obtained by dispersing conductive nanometal powder in the ink component. The colloidal ink has a low viscosity of 5 to 50 cps.
The manufacturing method of the nano metal powder having a diameter of 100 nm or less includes a wet method in which a dispersion material is coated on the outermost surface of the particles to prevent aggregation when reducing and metallizing solution-like silver ions, and a high energy is applied to the metal surface. There is a dry method for producing a fine metal powder by liquefying, and in the present invention, a nano metal powder by any of these methods can be adopted.

The nano metal powder is blended in the ink component as a dispersion previously dispersed in a solvent, and stirred to be uniformly dispersed in the ink component.
As the solvent, there are a solvent system and an aqueous system, but the use of the aqueous solvent hardly swells the silicone rubber, and as a result, stable printing is possible even if continuous printing is performed. Furthermore, there is little influence on the environment, and no special exhaust device is required, which is advantageous in terms of cost. And in the case of a solvent system, if the kind of solvent is changed, the dispersion stability of a nano metal powder will collapse | crumble and there also exists a problem which is easy to generate | occur | produce condensation.

  However, when a colloidal ink in which nano metal powder is dispersed in an aqueous solvent is applied to the surface of the silicone blanket, the surface tension of the ink almost corresponds to the surface tension of the solvent. There is a problem that ink is repelled on the surface of the silicone blanket.

In this regard, in order to improve the wettability of the silicone rubber surface of the silicone blanket without reducing the surface tension of the ink using an aqueous solvent, in the present invention, as described above, the surface of the silicone rubber is previously hydrophilized. Even if the colloidal ink in which the nano metal powder is dispersed in an aqueous solvent has a low viscosity of 5 to 50 cps, it can be easily adapted to the surface of the silicone rubber and can be applied uniformly without being repelled on the entire surface. it can.
In addition, if the surface of the blanket is replaced with silicone rubber and a high-energy polymer material is used, the wettability of the surface can be improved. In this case, the applied ink is strongly adhered to the blanket surface, and the ink transferability is improved. Remarkably worse. Therefore, it is preferable to hydrophilize the surface using a silicone blanket.

  Although there are various methods for the hydrophilic treatment, a method in which the surface is not brought into contact with the surface of the silicone rubber is preferable, and from this viewpoint, the method of hydrophilicizing the silicone rubber by irradiating with ultraviolet rays is most preferable. Silicone rubber is a material that has very strong light resistance to radiation such as ultraviolet rays, but the diene part (Si-C = C-) contained in the silicone rubber is hydrophilic by being oxidized by receiving ultraviolet rays. It has the property of improving the properties. Moreover, hydrophilicity can be improved by previously blending silicone oil having a highly hydrophilic hydroxyl group (—OH) in silicone rubber. Furthermore, a modified silicone rubber in which a hydroxyl group (—OH) is partially introduced into the silicone rubber molecule may be used.

It is simple and effective to evaluate the degree of hydrophilization with the contact angle of pure water. The contact angle of pure water with a normal silicone rubber surface not subjected to hydrophilic treatment is as large as about 110 degrees, and in this state, the water-based nanometal powder ink is greatly repelled on the surface during application.
As described above, the contact angle of pure water can be reduced to 30 to 70 degrees by hydrophilizing the silicone rubber by ultraviolet light irradiation or the like. As a result, the colloidal ink in which the nano metal powder is dispersed in the aqueous solvent can be applied uniformly without being repelled from the surface of the hydrophilized silicone rubber. In addition, the transferability and transferability of the ink, which are the original functions of the silicone blanket, are not impaired. The contact angle and the flipping property are highly correlated, and the contact angle is 70 degrees or less, preferably 50 degrees or less, in order to suppress playing.

The viscosity of the colloidal ink is set to 5 to 50 cps. If it is less than 5 cps, the fluidity is too good, so that the coating property on the silicone blanket surface is not stable. On the other hand, if it exceeds 50 cps, the coating stability is improved. However, a lot of viscosity modifiers are required. And by setting it as the said viscosity range, the removal of the said ink apply | coated to the surface of the silicone blanket by the intaglio or the letterpress, the transfer to the to-be-printed body of the ink remaining in the blanket, and a transfer can also be performed exactly.
The viscosity of the colloidal ink is more preferably 10 to 30 cps.

Moreover, since the metal powder contained in the colloidal ink is a nano metal powder having an average particle diameter of 0.1 to 100 nm, the entire surface area of the metal powder can be remarkably increased. As a result, the melting point of the metal powder is greatly increased. Can be lowered. Specifically, when silver having a melting point of 900 ° C. is finely dispersed at the 10 nm level, the melting point can be lowered to 150 ° C.
Therefore, after the ink remaining on the blanket surface is transferred to a substrate such as a substrate, it is heated to fuse the nanometal powders together, and a desired electrode made of a conductive metal layer is fixed on the substrate. The heating temperature can be reduced to 150 ° C. Thus, when the heating temperature is lowered, the heat burden on the substrate is reduced, and the occurrence of distortion and deterioration of the substrate can be prevented.
That is, conventionally, since a high temperature treatment exceeding 250 ° C. is necessary as described above, the influence on the substrate was great. Low electrodes can be formed by printing.
In view of the above, it is preferable to lower the heating temperature, and the heating temperature is 250 ° C. or lower, more preferably 200 ° C. or lower. Moreover, the shorter the heating time, the more preferable, 5 minutes to 60 minutes, and more preferably 10 minutes to 30 minutes.

  For the reasons described above, the average particle size of the conductive nanometal powder is set to 100 nm or less, and if it exceeds 100 nm, the fusion temperature between metals tends to increase, and the heating temperature needs to be increased. On the other hand, the reason why the thickness is 0.1 nm or more is that when it is less than 0.1 nm, it is difficult to handle, and the dispersibility in the colloidal solution tends to deteriorate. The average particle size of the conductive nanometal powder is preferably 1 to 100 nm, and most preferably 5 to 20 nm.

  On the other hand, the boiling point of the colloidal ink is also an important parameter. As the ink is applied onto the silicone blanket, the solvent evaporates and the ink viscosity decreases with evaporation. Accordingly, when the boiling point of the ink is low, the evaporation is accelerated and the viscosity of the ink is increased rapidly, so that it is difficult to apply the ink. In this regard, when water having a boiling point of 100 ° C. is used as a solvent, water has a large latent heat of vaporization, and the ink viscosity rises slowly at room temperature, so that it becomes relatively easy as a printing ink.

As the conductive nanometal powder used in the present invention, gold, silver, copper, platinum, palladium, nickel and a mixture thereof are preferably used. These metals have excellent conductivity and can be easily formed into the above-mentioned very fine nanoparticles. In particular, silver is suitable from the viewpoint of cost and conductivity, but is not limited to the metal described above.
The particle shape of the nano metal powder can be various shapes such as a spherical shape, an elliptical spherical shape, a columnar shape, a scale shape, and a fibrous shape within the range of the average particle diameter.

The ink component mixed with the nano metal powder is made of a resin, and a resin having compatibility with an aqueous solvent such as a polyester-melamine resin, an acrylic resin, a melamine resin, and a phenol resin is used.
As the aqueous solvent for the nano metal powder, alcohol or the like can be used in addition to pure water.
A dispersion in which nano metal powder is dispersed in a solvent is blended in the ink resin, pre-stirred with a planetary mixer, and then sufficiently stirred and dispersed with a bead mill or the like to prepare the colloidal solution. is doing.

  It is desirable that the conductive nanometal powder is uniformly dispersed in the colloidal solution at a ratio of 10 to 95% by volume of the total volume. This is because if the range is less than 10% by volume, the metal powders are hardly adhered to each other, and the metal layer is difficult to form during heating. On the other hand, if it exceeds 95% by volume, the colloidal solution aggregates without being stable, the particle size becomes large, and melting at a low temperature becomes impossible. More desirably, it is 30 to 80% by volume.

The colloidal ink is applied to the hydrophilic silicone rubber surface of the blanket by a method selected from a slit die coater, a bar coater, a spin coater, screen printing, a roll coater and the like.
At that time, as described above, when an aqueous solvent is used, in a state where it is applied to the surface of the silicone rubber blanket, since the latent heat of evaporation is large, drying is not fast, and the viscosity of the ink does not increase rapidly, It becomes easy to control the removal of ink in the plate or the transfer to a printing medium.

  The surface hardness of the silicone rubber to which the colloidal ink is applied is preferably 70 to 20 in terms of JIS-A hardness. If it exceeds 70, it is too hard to deform and the ink on the plate cannot be transferred sufficiently. On the other hand, if the hardness is less than 20 and the hardness is low, the deformation of the surface rubber becomes large and it becomes difficult to print with high accuracy. More preferably, it is 60-30.

  Further, the surface roughness of the silicone rubber greatly affects the printing accuracy as the printing pattern becomes finer. For forming a fine pattern with a line width of about 20 μm, the surface roughness is preferably 10 μm or less in terms of 10-point average roughness, and more preferably a smooth surface of 0.5 μm or less.

  As the plate for removing a part of the colloidal ink (non-printing portion) applied to the silicone rubber surface, either an intaglio plate or a relief plate can be used. As the plate material, a soda glass, non-alkaline glass, or the like that has been subjected to an etching process and provided with irregularities corresponding to a desired circuit pattern, or a metal material that has been similarly etched is employed. The As the glass material, inexpensive soda glass is preferably used in a field where high dimensional accuracy is not required. Also, as the metal material, stainless steel, 42 alloy (Fe—Ni alloy), copper, brass, amber material, etc., which have good etching properties can be used.

Since the electrode plate obtained by the above printing method forms an electrode with a metal layer in which conductive nano metal powders are fused together, the electrode has excellent conductivity, low electrical resistance, and no shading. It is possible to provide a uniform electrode circuit pattern that is uniform and unbroken. Therefore, it is extremely excellent as an electrode plate such as a TFT on which an electrode used in a liquid crystal image forming apparatus is formed or an electrode plate for other electronic components.
The thickness of the metal layer constituting the electrode circuit pattern is desirably adjusted to be 1 to 15 μm. If it is thinner than 1 μm, it is easy to disconnect, and the conductivity tends to decrease. On the other hand, even if it is thicker than 15 μm, the conductivity is sufficiently satisfied and the material cost is wasted, and the flatness of the surface is deteriorated.

As is clear from the above description, according to the present invention, the colloidal ink in which the conductive nano metal powder is dispersed is directly applied in a state where the silicone rubber surface of the silicone blanket is hydrophilized, and the intaglio or letterpress is applied thereto. This is a simple process that does not cause an increase in equipment cost because it removes unnecessary ink and transfers the remaining ink to the substrate to be printed, followed by heating at a low temperature for curing and fixing. Thus, it is possible to easily print and manufacture an electrode plate having an excellent conductivity and a precise electrode circuit pattern.
In particular, since the surface of the silicone rubber is wetted by a hydrophilization treatment, it can be stably applied without being repelled from the surface of the silicone rubber while being a low-viscosity colloidal ink. At the same time, it is possible to stably transfer the required pattern onto the surface of the substrate to be printed, and it is possible to reliably obtain a precise electrode pattern with excellent conductivity.
In addition, since the conductive nano metal powder dispersed in the colloidal ink has a very fine average particle size of 0.1 to 100 nm, the surface area of the entire metal powder to be blended can be increased. The deposition temperature can be significantly reduced. As a result, the metal powders can be fused together at a low temperature, the heating temperature after transfer to the printing medium can be lowered to 250 ° C. or less, the thermal load on the printing medium can be reduced, and the printing medium It is possible to prevent thermal deterioration and the like from occurring.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1A, 1B and 1C show a printing process according to an example of the electrode printing method of the present invention, and FIGS. 2A and 2B are enlarged views of the main parts of FIGS. 1B and 1C, respectively. FIG. 3 shows a schematic view of an electrode plate obtained by the printing method.

The printing machine 1 shown in FIG. 1 is a reverse offset printing machine.
The silicone blanket 20 is made of a silicone blanket in which the surface of a cylindrical blanket cylinder is covered with the silicone rubber 2. The silicone rubber 2 coated with the blanket copper has been subjected to hydrophilic treatment by irradiating with ultraviolet rays in advance. The degree of hydrophilicity is set so that the contact angle of pure water is in the range of 30 to 70 degrees. The thickness of the silicone rubber 2 is 0.1 mm to 2 mm, the hardness is in the range of 20 to 70 according to JIS-A, and the surface roughness is a smooth surface with an average of 10 points of 1.0 μm or less.

  The silicone blanket 20 does not show a moving mechanism, but is moved in the order of steps as shown in FIGS. 1A, 1B and 1C, and a rotating shaft 25 attached to a movable frame is pivoted. It is configured to penetrate through the core and rotate at a required rotational speed.

  In the position shown in FIG. 1A, a slit die coater device 3 for applying colloidal ink Q is disposed above the silicone blanket 2, and a drying device 6 is disposed on the side. The drying device 6 includes a heating device 61 and a cooling device 62, and hot air and / or cold air is blown onto the ink application surface from the respective air blowing ports 61a and 62a. The heating device 61 and the cooling device 62 are properly used or used appropriately according to conditions such as room temperature and coating film.

A base 10 is fixed to the position shown in FIG. 1B where the colloidal ink is applied to the surface of the silicone rubber 2 of the silicone blanket 20, and the intaglio 4 is placed on the upper surface of one side of the base 10. Is placed. The concave portion 4a of the intaglio 4 has an electrode pattern shape, and the other portion is a convex portion 4b.
The transferred silicone blanket 2 is moved while rotating on the surface of the intaglio plate 4, and the convex portion 4 b of the intaglio plate 4 is pressed against the ink application surface to transfer the ink Q onto the surface of the convex portion 4 a. On the other hand, the portion of the concave portion 4 a that becomes the electrode pattern is configured to leave the ink Q on the surface of the silicone blanket 2.

  A printing substrate 5 such as a glass substrate is fixed on the upper surface of the base 10 on the silicone blanket conveyance side, unnecessary ink Q is removed by the intaglio plate 4, and the ink Q remaining in the electrode pattern is printed. The image is transferred to the upper surface of the body 5 while being rotated, and a required electrode pattern is printed on the surface of the substrate 5 to be printed.

An electrode printing method using the reversal offset printer having the above-described configuration will be described below.
Colloidal ink Q is prepared by pre-stirring polyester-melamine resin as a resin component and water-based dispersed conductive nano metal powder (average particle size 0.1-100 nm) with a planetary mixer, and finally dispersing with a bead mill. And the viscosity is adjusted to 5 to 50 cpc. The conductive nano metal powder is 10 to 95% by volume of the colloidal ink Q.
The colloidal ink Q prepared in this way is applied to the blanket cylinder rotating in the direction of the arrow in FIG. It applies so that it may become 5-20 micrometers. At that time, since the surface of the silicone rubber 2 is hydrophilized, the colloidal ink Q can be applied uniformly without being repelled.

After the application, the applied colloidal ink Q is dried by heating or / and cooling with a drying device 6. After drying, the silicone blanket 20 is conveyed above the base 10 as shown in FIG.
When reaching above the intaglio 4 of the base 10, the silicone blanket 20 is moved in the direction of the arrow while being rotated at a required rotational speed, and is rolled along the upper surface of the intaglio 4. Thereby, as shown in the enlarged view of FIG. 2A, the convex portion 4b of the intaglio 4 is sequentially pressed against the ink Q application surface of the silicone blanket 20. At this time, the ink Q1 in the pressing portion is transferred to the surface of the convex portion 4b, and the ink Q2 in the non-pressing portion corresponding to the concave portion 4a remains on the surface of the silicone blanket 2.

  The silicone blanket 20 that has finished rolling on the intaglio 4 has the ink (ink pattern) Q2 corresponding to the recess 4a held on the surface of the silicone rubber 2, and continues in the direction of the arrow as shown in FIG. To roll on the substrate 5. While the silicone blanket 20 rolls on the substrate 5, the ink pattern Q2 is sequentially transferred to the substrate 5 in contact with the surface of the substrate 5 as shown in the enlarged view of FIG. A transfer ink pattern Q3 is formed. The printed material 5 on which the transfer ink pattern Q3 is formed is held in a clean oven (not shown) at 200 ° C. or lower for 10 to 20 minutes, heat-treated, the nano metal powders are fused together, and the transfer A metal band composed of the ink pattern Q3 is cured and fixed on the substrate 5 using the cured layer of the ink resin as an adhesive.

FIG. 3 shows the manufactured electrode substrate, and an electrode pattern 7 is formed on the substrate 5 to be printed.
Since the electrode pattern 7 is formed by fusing nano metal powder, the electrode pattern 7 is excellent in conductivity and has an electric resistance value of 1 × 10 ⁻⁵ Ω · cm to 2 × 10 ⁻⁶ Ω · cm (specific resistance). can do.

As described above, in the electrode forming method of the present invention, the silicone rubber on the surface of the silicone blanket is hydrophilized to improve the wettability, so that the colloidal ink Q in which the nano metal powder is dispersed is not repelled. It can be applied stably with a uniform thickness.
Moreover, since the average particle diameter of the nano silver powder dispersed in the ink Q is very fine, 0.1 to 100 mm, even if the heat treatment temperature is lowered to 200 ° C. or less, the nano silver powders Can be fused together. By this low temperature treatment, the printing medium 5 made of a glass substrate or the like can prevent thermal distortion or the like from occurring. Therefore, the electrode substrate thus obtained has excellent suitability as an electrode substrate for TFTs and the like.
Moreover, even if continuous printing is performed using the printing machine 1, the silicone rubber 2 of the silicone blanket 20 does not swell, so that a stable coating surface can be formed without any change in coating properties, and continuous printing can be performed with high accuracy. It can be carried out.

In addition, in the said embodiment, although the ink supply apparatus uses the slit die coater apparatus 3, it is not limited to this, Moreover, the dryer 6 is not limited to embodiment but can also be made unnecessary, The printing machine 1 The configuration is not limited to the configuration of the embodiment.
Moreover, although the example using the intaglio plate 4 as a plate for transferring and removing a part of the colloidal ink Q applied to the surface of the silicone rubber blanket 20 has been described, it may be a relief plate. Furthermore, it goes without saying that a glass substrate, a resin substrate, a metal substrate, a ceramic substrate, and the like can also be used as the substrate to be printed.

"Example"
The example was prepared as an electrode substrate to be used for the Alui wiring portion of the TFT liquid crystal substrate (diagonal 30 inches).

The silicone blanket 20 was prepared by making the silicone rubber 2 of the surface layer with silicone rubber manufactured by Sumitomo Rubber Co., Ltd. (rubber hardness JIS-A is 40, room temperature curing type silicone rubber addition type), and the rubber thickness was 600 μm. As a support layer of the silicone rubber 2, a laminated film and a PET (polyethylene terephthalate) film having a thickness of 350 μm were integrated.
The surface roughness of the silicone rubber was 10 μm and the average roughness was 0.1 μm.
The surface of the silicone rubber 2 was subjected to a hydrophilic treatment by irradiating the surface with ultraviolet light using an ultraviolet lamp having a peak at 250 nm. The irradiation condition was an irradiation time of 60 seconds. After irradiation, the degree of hydrophilicity of the silicone rubber was about 40 degrees in terms of contact angle with pure water.

The colloidal ink Q was prepared by pre-stirring a polyester-melamine resin as a resin component and an aqueous dispersion of silver nanopowder (average particle size 10 nm) with a planetary mixer and finally dispersing with a bead mill. Silver nanopowder was blended at 75% by volume of the colloidal ink.
The colloidal ink Q was applied on the surface of the silicone rubber 2 of the silicone blanket 20 using the slit die coater 3 so as to have a thickness of 10 μm.
After application, the colloidal ink Q was dried by heating at 100 ° C. for 1 minute with the drying device 6.
After drying, the silicone blanket 20 was rolled on the surface of the intaglio 4.

  The intaglio 4 was provided with a concave portion 4a and a convex portion 4b by etching so as to have the same shape and pattern as the printed pattern on a soda lime glass plate. The printed pattern was the same as the aluminum electrode pattern with a line width of 20 μm, the width of the recess 4a was 20 μm, and the depth was 10 μm. Since the concavo-convex part is an electrode drawn from the TFT array, the pattern direction is assumed to be a mixture of vertical and horizontal directions.

By rolling the silicone blanket 20 on the intaglio plate 4, the ink Q is transferred to the surface of the convex portion 4b, and only the ink of the non-pressing portion corresponding to the concave portion 4a is left on the surface of the silicone rubber 2 of the silicone blanket 20. It was.
Subsequently, the silicone blanket 20 was rolled while applying a required pressing force on the glass substrate, and the ink on the silicone rubber 2 was sequentially brought into contact with the glass substrate 5 and transferred.
After the transfer, the glass substrate 5 was heat-treated in a clean oven at 200 ° C. for 20 minutes.

The electric resistance of the electrode of the electrode substrate formed by the above method was 4 × 10 ⁻⁶ Ω · cm. In addition, the electrode has a line width of 20 μm and is formed in a predetermined pattern with a high density.

"Comparative example"
The same silicone rubber as in the example was not subjected to a hydrophilic treatment. Therefore, the contact angle of pure water with the surface of the silicone rubber was 110 degrees.
Other conditions were the same as in the example.
First, application of the colloidal ink Q to the surface of the silicone rubber 2 of the silicone blanket 20 was attempted. Immediately after the application, the ink Q was repelled on the surface of the silicone rubber 2. Thereafter, in the same manner as in the Examples, after removing and removing unnecessary portions of ink by the intaglio, it was transferred to a glass substrate and heat-treated to cure and fix the ink.

  The manufactured electrode on the glass substrate had many pinholes, and a good printed product could not be obtained.

  The present invention is most preferably used as an electrode printing method, and can be used as a method for producing a PDP front electrode, a back electrode, a flexible printed circuit board, a high-density laminated circuit board, an electromagnetic wave shield from an electric device, and the like.

(A) (B) (C) is explanatory drawing of the printing process by an example of the electrode printing method of this invention. (A) (B) is an enlarged view of the principal part of FIG. 1 (B) (C), respectively. It is a conceptual perspective view which shows an example of the electrode plate obtained by the printing method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Printing machine 20 Silicone blanket 2 Silicone rubber 3 Slit die coater device 4 Intaglio 5 Printed object (glass substrate)
7 Electrode pattern Q Colloidal ink Q2 Ink pattern Q3 Transfer ink pattern

Claims (7)

On the surface of a blanket made of smooth silicone rubber with a hydrophilic treatment on the surface,
A conductive nano metal powder having an average particle size of 0.1 to 100 nm is dispersed in the ink component, and a colloidal ink whose viscosity is adjusted to 5 to 50 cps is applied, and then,
Removing the ink of unnecessary portions from the blanket surface by pressing an intaglio or letterpress having a predetermined pattern against the application surface;
The ink left in the required pattern on the surface of the blanket is transferred to the substrate,
Then, the printed material is heated, and the conductive nano metal powder in the transferred ink is fused,
Next, an electrode printing method is characterized in that an electrode is formed by curing and fixing a fused conductive nano metal powder on a substrate to be printed. The electrode printing method according to claim 1, wherein any one of the following methods (1) to (3) is used as a method for hydrophilizing the silicone rubber surface.
(1) Irradiating the silicone rubber surface with ultraviolet rays to oxidize a part of the surface rubber;
(2) A silicone oil having a hydroxyl group in the molecule is blended in the silicone rubber;
(3) Modified silicone rubber in which hydroxyl groups are partially introduced into the silicone rubber molecule is used.   The electrode printing method according to claim 2, wherein the contact angle of pure water to the silicone rubber is set to a hydrophilization degree in the range of 30 to 70 degrees by the hydrophilic treatment of the silicone rubber surface.   The electrode printing method according to any one of claims 1 to 3, wherein the conductive nano metal powder is made of any one of gold, silver, copper, platinum, palladium, nickel, and a mixture thereof. The colloidal inks, a dispersion of the conductive nano metallic powder dispersed in an aqueous solvent, electrode printing according to any one of the ink components in the formulation to claims 1 to have prepared 4 Law.   The electrode printing method according to any one of claims 1 to 5, wherein a temperature during the heat treatment after the colloidal ink is transferred to the substrate to be printed is 250 ° C or lower.   An electrode substrate comprising an electrode printed by the electrode printing method according to any one of claims 1 to 6 on a substrate.

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