JP2008201815A - Printing ink composition, method for producing the same, method for forming electrode for plasma display panel using the composition and electrode - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printing ink composition enabling high-precision printing, leaving less or no residues of organic components in baking and satisfying the high-precision printing and the good electrical conductivity at the same time. <P>SOLUTION: The printing ink composition 11 is composed of the mixture of a conductive metal powder, glass frit, resin component and solvent component, and is printed on a substrate 14 with a desired pattern and dried and baked. The resin component of the printing ink composition 11 is an alicyclic resin component obtained by hydrogenating a resin containing an aromatic component, and the amount of the aromatic component in the alicyclic resin component is ≤0.5 pt.wt. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a printing ink composition that can be used to form a bus electrode of a front panel for a plasma display panel (hereinafter referred to as PDP) or an address electrode of a back panel for a PDP. And a method for producing the composition, a method for forming the bus electrode and the address electrode using the composition, and an electrode formed using the ink composition.

  Conventionally, a photolithography method has been used to form electrodes and the like in semiconductor devices such as electronic circuit boards and display devices. However, this photolithography method has a complicated manufacturing process and has a lot of material loss, so that pattern formation can be performed. There is a problem that the manufacturing cost becomes extremely high because a huge amount of cost is required for manufacturing equipment such as an exposure apparatus. Furthermore, the cost of processing the waste liquid generated in the development process at the time of pattern formation is high, and the waste liquid has a problem from the viewpoint of environmental protection.

  Thus, various researches have been conducted on pattern formation methods that are low in cost and do not generate harmful waste liquids. In particular, the intaglio offset printing method is attracting attention as an alternative to the photolithography method because it can form a fine pattern with high accuracy. In the intaglio offset printing method, 100% of the printing ink composition is transferred from the printing blanket to a transfer medium such as a glass substrate. Therefore, a silicone rubber sheet is used on the printing blanket surface, and printing is performed on the printing ink composition. It is easy to peel off the printing ink composition from the silicone rubber by adding a solvent that easily wets the silicone rubber on the surface of the printing blanket and does not easily penetrate, and reduces the tension at the interface between the printing ink composition and the silicone rubber. Thus, the printing ink composition is transferred from the printing blanket onto the substrate.

  Examples of the printing ink composition include conductive metal powder, glass frit, transition metal oxide and dispersant, polyiso-butyl methacrylate, polyiso-propyl methacrylate, polymethyl methacrylate, polytetrafluoroethylene or poly-α. -The conductive ink comprised from the vehicle containing the at least 1 sort (s) or more of organic binder of methylstyrene is disclosed (for example, refer patent document 1). With the conductive ink configured in this way, it is possible to prepare ink suitable for offset printing, and it is easy to create a high-definition pattern on the circuit board by offset printing, and the edge linearity than the conventional screen printing method In addition, it is possible to form a fine pattern with less occurrence of scratches and chips, and to obtain a high quality pattern from the viewpoint of accuracy.

The printing ink composition comprises at least a conductive powder and an organic component that can be removed by baking, contains the conductive powder in a range of 60 to 90% by weight, and contains 10 to 40 organic components that can be removed by baking. A photocurable conductive ink contained in the range of wt% is disclosed (for example, see Patent Document 2). This photocurable conductive ink contains a photoreactive acrylic resin, a photoreactive monomer, and an oligomer to which a functional group reactive with styrene is added in an organic component. In the photocurable conductive ink thus configured, the dispersibility of the conductive powder is improved, and the viscosity of the ink can be controlled to a desired value, so that a highly accurate electrode pattern can be formed by the lithographic offset printing method. It has become.
JP-A-4-213373 (Claim 2, paragraph [0007], paragraph [0012]) JP 2002-285063 A (claim 1, paragraph [0008], paragraph [0012])

As for electrodes for PDP, it is essential to obtain high-quality fine patterns with excellent edge linearity and few occurrences of chipping, etc. In recent years, with the miniaturization of electrodes accompanying the increase in resolution of display parts Ensuring high quality with thinner electrodes is an issue.
In the conventional conductive ink shown in Patent Document 1 and the photocurable conductive ink shown in Patent Document 2, since an aromatic resin such as styrene is used as an organic binder, printing with higher accuracy is possible. Is possible.
However, when an aromatic resin is used as the resin component of the printing ink composition, such as the conductive ink shown in the above-mentioned conventional Patent Document 1 and the photo-curable conductive ink shown in Patent Document 2, when firing, The organic component was not completely burned out but remained in the electrode, and the conductivity of the electrode could be lowered.
An object of the present invention is to provide a printing ink composition that can be printed with high accuracy, and has no or almost no organic component left during firing, and can achieve both high-precision printability and good conductivity. It is an object of the present invention to provide an electrode, a manufacturing method thereof, a method of forming an electrode for a plasma display panel using the composition, and an electrode thereof.

As shown in FIG. 1, the invention according to claim 1 is composed of a mixture containing conductive metal powder, glass frit, a resin component and a solvent component, printed on a substrate 14 in a desired pattern, dried and fired. This is an improvement of the printing ink composition 11.
The characteristic structure is that the resin component is an alicyclic resin component obtained by hydrogenating a resin containing an aromatic component, and the aromatic component contained in the alicyclic resin component is 0. The amount is 5 parts by weight or less.
In the printing ink composition described in claim 1, the resin component in the printing ink composition 11 is an alicyclic resin component obtained by hydrogenating a resin containing an aromatic component. Since the alicyclic resin component has good dispersibility of the conductive metal powder and the viscosity of the ink composition 11 can be easily adjusted, the printing ink composition 11 containing the alicyclic resin component is desirable. Can be printed with high definition on the pattern. Moreover, since the aromatic component containing the benzene ring which causes a flame hardly in the resin component in the printing ink composition 11 is 0.5 parts by weight or less, the printing ink composition 11 is patterned on the substrate 14. In the electrode obtained by printing and forming a coating film, drying and baking this coating film, the organic component which inhibits electroconductivity does not remain at all or hardly, and can improve the electroconductivity of an electrode.

The invention according to claim 3 includes a step of obtaining an alicyclic resin component in which the aromatic component is 0.5 parts by weight or less by hydrogenating a resin containing the aromatic component, and an alicyclic resin component; A method for producing a printing ink composition comprising a step of preparing a printing ink composition by mixing conductive metal powder, glass frit and a solvent component.
In the method for producing a printing ink composition according to claim 3, the resin component in the printing ink composition is an alicyclic resin component obtained by hydrogenating a resin containing an aromatic component, and is conductive. Since the dispersibility of the metal powder is good and the viscosity of the ink composition 11 can be easily adjusted, using the printing ink composition containing this alicyclic resin component, high-definition printing is performed in a desired pattern. Can do. In addition, since the aromatic component containing a benzene ring that causes incombustibility in the resin component is 0.5 parts by weight or less, this printing ink composition is pattern-printed on a substrate to form a coating film. When the film is dried and baked, there is no or almost no organic component that inhibits conductivity in the electrode, and the conductivity of the electrode can be improved.

As shown in FIG. 1, the invention according to claim 4 includes a step of printing a printing ink composition 11 according to claim 1 or 2 in a desired pattern on a substrate 14 to form a coating film, A method of forming an electrode for a plasma display panel, comprising: drying and baking the film to form an electrode.
The invention according to claim 5 includes a step of printing the ink composition 11 for printing produced by the method of claim 3 in a desired pattern on the substrate 14 to form a coating film, and drying the coating film. A method of forming an electrode for a plasma display panel including a step of forming an electrode by firing.
In the method for forming an electrode for a plasma display panel according to claim 4 or claim 5, an electrode having high-definition printability and good conductivity can be formed relatively easily.

The invention according to claim 6 is an electrode for a plasma display panel formed using the printing ink composition according to claim 1 or 2.
The invention according to claim 7 is an electrode for a plasma display panel formed by using the method for producing a printing ink composition according to claim 3.
The invention according to claim 8 is an electrode for a plasma display panel formed by using the electrode forming method according to claim 4 or 5.
The electrode for a plasma display panel according to any one of claims 6 to 8 is an electrode having high-definition printability and good conductivity.

According to the present invention, the resin component of the printing ink composition is an alicyclic resin component obtained by hydrogenating a resin containing an aromatic component, and is included in the alicyclic resin component. Since the aromatic component is 0.5 parts by weight or less, this printing ink composition is pattern-printed on a substrate, dried, and further baked, resulting in excellent edge linearity and occurrence of chipping and the like. It is possible to obtain an electrode with a small number of high-quality fine patterns, and the resin component does not remain in the electrode and the specific resistance of the electrode can be reduced. As a result, an electrode that achieves both high-precision printability and good conductivity can be formed using the printing composition.
Moreover, after obtaining the alicyclic resin component which made the aromatic component 0.5 weight part or less by hydrogenating the resin containing an aromatic component, this alicyclic resin component, electroconductive metal powder, and glass If a frit and a solvent component are mixed to prepare a printing ink composition, the printing ink composition is pattern-printed on a substrate, dried, and further baked to achieve high-precision printability and good conductivity. Therefore, it is possible to relatively easily form an electrode having both properties.
Furthermore, after printing the ink composition for printing in a desired pattern on a substrate to form a coating film, the coating pattern is dried by baking the coating film to form an electrode for a plasma display panel. Becomes high definition and has good conductivity.

Next, the best mode for carrying out the present invention will be described.
The printing ink composition of the present invention comprises a mixture containing conductive metal powder, glass frit, a resin component and a solvent component. When the conductive metal powder is 100 parts by weight, the glass frit is preferably blended so as to have a ratio of 1 to 10 parts by weight, more preferably 2 to 5 parts by weight. Moreover, about the ratio of a resin component and a solvent component, when a resin component shall be 100 weight part, it mix | blends so that a solvent component may become the ratio of preferably 30-200 weight part, More preferably, 50-120 weight part. . Furthermore, when the conductive metal powder is 100 parts by weight, the total amount of the resin component and the solvent component is preferably 10 to 50 parts by weight, more preferably 15 to 30 parts by weight. Here, the glass frit was limited to the range of 1 to 10 parts by weight with respect to 100 parts by weight of the conductive metal powder. This is because the adhesion is poor, and if it exceeds 10 parts by weight, the conductivity of the electrode after firing is lowered. Further, the solvent component is limited to the range of 30 to 200 parts by weight with respect to 100 parts by weight of the resin component. If the amount is less than 30 parts by weight, printing failure occurs due to volatilization of the solvent. This is because sagging of the ink composition after printing due to a decrease in the viscosity of the ink occurs. Further, the total amount of the resin component and the solvent component is limited to the range of 10 to 50 parts by weight with respect to 100 parts by weight of the conductive metal powder. This is because if the amount exceeds part by weight, dripping of the ink composition after printing due to a decrease in the viscosity of the ink composition occurs.

  On the other hand, the average particle size of the conductive metal powder is preferably set within a range of 0.1 to 1.0 μm. Examples of the conductive metal powder include silver powder, copper powder, aluminum powder, gold powder, and nickel powder. The glass frit is composed of one or more oxides selected from the group consisting of lead oxide, bismuth oxide, zinc oxide, boron oxide, silicon oxide, aluminum oxide, phosphorus oxide, calcium oxide and titanium oxide, An oxide having a softening point of ˜500 ° C. is preferred. The average particle size of the glass frit is preferably set within a range of 0.1 to 1.0 μm. Here, the average particle size of the conductive metal powder is limited to the range of 0.1 to 1.0 μm, and if it is less than 0.1 μm, the viscosity of the ink composition becomes high, and offset printing by the intaglio is difficult. This is because if the thickness exceeds 1.0 μm, the sinterability of the electrode after firing is poor and the conductivity is lowered. Further, the softening point of the glass frit is limited to the range of 350 to 500 ° C. If the temperature is lower than 350 ° C., the sintering of the conductive metal powder is inhibited at the time of firing, and the conductivity is lowered. This is because the adhesion of the subsequent electrode to the base material (glass substrate or the like) is lowered. Furthermore, the average particle size of the glass frit is limited to the range of 0.1 to 1.0 μm. If the average particle size is less than 0.1 μm, the adhesion of the electrode after firing to the base material (glass substrate or the like) decreases. If the thickness exceeds 1.0 μm, the conductivity of the electrode after firing is lowered.

  As the resin component, a resin containing a large amount of an aromatic component as 80 to 100 parts by weight, and a resin in which an alicyclic resin component is synthesized by hydrogenating the resin containing the aromatic component is used. The limitation to such resins is that if the resin containing a large amount of aromatic components is used, carbonization will occur during firing and organic components will remain, whereas hydrogenation will result in no or little aromatic components. This is because the resin of the formula does not carbonize at all or hardly at the time of firing, and all or almost all is burned out. Specifically, the alicyclic resin component is selected from the group consisting of hydrogenated styrene resin, hydrogenated bisphenol A type epoxy resin, hydrogenated bisphenol F type epoxy resin, and long-chain aliphatic diglycidyl ether. In addition, one or a mixture of two or more single or mixed resin components. In addition, when synthesizing an alicyclic resin by hydrogenation, unreacted aromatics may remain in the resin as residual components. However, the ratio of the unreacted aromatics depends on the alicyclic resin component. When it is 100 parts by weight, it is 0.5 parts by weight or less, preferably 0.4 parts by weight or less. Here, the content of the unreacted aromatic is limited to 0.5 parts by weight or less. If the content of the unreacted aromatic exceeds 0.5 parts by weight, the resin disappearance at the time of firing deteriorates and the conductivity of the electrode decreases. Because it ends up. As a specific method for synthesizing an alicyclic resin component by hydrogenating a resin containing an aromatic component, a resin containing the aromatic component is dissolved in ethers such as tetrahydrofuran, and then a platinum group such as rhodium is used. Examples thereof include a method of synthesizing an alicyclic resin component by hydrogenation in the presence of a catalyst at a temperature of 50 to 130 ° C. and a hydrogen pressure of 3 to 15 MPa.

  The solvent component is not particularly limited as long as it is an organic solvent that can dissolve the resin component. Specific examples of the solvent component include alcohol solvents, ketone solvents, ether solvents, carbitol solvents, hydrocarbon solvents, diol solvents, glycol solvents, glycol ether solvents, and the like. A solvent in which a plurality of solvents are mixed can also be used. In order to cure after drying, an unsaturated monomer such as an acrylic monomer or a methacrylic monomer and a thermal radical compound such as butyl peroxide may be added to the printing ink composition. In addition, in order to cure by ultraviolet rays rather than heat curing, an unsaturated monomer such as an acrylic monomer and a methacrylic monomer, and 2-methyl-1 (4-methylthio) phenyl) -2-monoforinopropane- You may add the compound which generate | occur | produces a radical with an ultraviolet-ray like 1-one. Such heat curing or ultraviolet curing additives are selected according to the equipment environment of the electrode forming process and are not directly related to the present invention.

A method for forming an electrode for PDP on a glass substrate by an intaglio offset printing method using the thus configured printing ink composition will be described with reference to FIG.
First, as shown in FIG. 1A, a flat intaglio 10 having a predetermined concave pattern 10a is prepared as a printing plate, and a predetermined amount of a printing ink composition 11 is supplied to the surface of the flat intaglio 10. The squeegee 12 is applied to the surface of the flat intaglio 10 and is slid to embed the printing ink composition 11 in the intaglio pattern 10a. Next, as shown in FIG. 1B, a blanket roll 13 having a silicone blanket 13a attached to the surface is prepared as a printing blanket, and the printing ink composition 11 is placed on the flat intaglio 10 embedded in the concave pattern 10a. In this state, the blanket roll 13 is pressed, and the blanket roll 13 is rotated to roll on the planographic intaglio 10 so that a portion of the ink 11 embedded in the concave pattern 10 a of the flat intaglio 10 is transferred to the silicone of the blanket roll 13. Transfer to the surface of the rubber sheet 13a. The transfer rate at this time is approximately 50 to 60%, although it varies depending on the concave pattern of the plane intaglio, the components and ratios contained in the ink composition, and the pressure of the blanket. Next, as shown in FIG.1 (c), the blanket roll 13 which transcribe | transferred the printing ink composition 11 is press-contacted to the glass substrate 14 (base material: to-be-transferred body), the blanket roll 13 is rotated in this state, By rolling on the glass substrate 14, the printing ink composition 11 is transferred to the surface of the glass substrate 14 in a predetermined pattern to form a coating film having a desired printing pattern (FIG. 1 (d)). Furthermore, after drying the glass substrate 14 on which the coating film having the desired print pattern is formed at 100 to 200 ° C. for 1 to 30 minutes in the air, the glass substrate 14 is dried at 500 to 600 ° C., preferably 540 to 580 in the air. Calcination is performed at 0 ° C. The firing temperature holding time is preferably 5 to 30 minutes, more preferably 10 to 20 minutes.

Next, examples of the present invention will be described in detail together with comparative examples.
<Example 1>
A spherical silver powder having an average particle diameter of 0.4 μm was prepared as the conductive metal powder, and a bismuth oxide-boron oxide glass frit having a softening point of 450 ° C. was prepared as the glass frit. Also, a hydrogenated bisphenol A type epoxy resin obtained by hydrogenating a bisphenol A type epoxy resin as a resin component was prepared, and a glycol ether solvent was prepared as a solvent component. At this time, the aromatic component contained in the hydrogenated bisphenol A type epoxy resin was 0.3 parts by weight. 100 parts by weight of the above conductive metal powder, 3 parts by weight of glass frit, 10 parts by weight of resin component, and 7 parts by weight of glycol ether solvent are mixed, and this mixture is dispersed for 30 minutes using a planetary mixer. Then, a paste-like printing ink composition was prepared by further dispersing for 3 minutes using a three-roll mill.
On the other hand, as shown in FIG. 1, as a printing plate used in the intaglio offset printing method, a planar intaglio 10 having a plurality of concave patterns with line width, depth and pitch of 150 μm, 30 μm and 300 μm, respectively, is prepared. As a material (transfer object), a 50-inch diagonal glass substrate 14 (front electrode substrate manufactured by Asahi Glass Co., Ltd .: PD200) having a thickness of 2.8 mm was prepared. As a printing blanket, a blanket roll 13 having a silicone rubber sheet (room temperature curing type silicone rubber (additional type)) having a thickness of 700 μm and a hardness of 40 (JIS K 6253 type A) attached to the surface. Prepared.

  First, a predetermined amount of the above-mentioned printing ink composition 11 was supplied to the surface of the flat intaglio 10, and the printing ink composition 11 was embedded in the concave pattern 10 a of the flat intaglio 10 using a SUS squeegee 12. Next, the blanket roll 13 is rotated in a state of being pressed against the flat intaglio 10 and is rolled on the flat intaglio 10, whereby a part of the printing ink composition 11 embedded in the concave pattern 10 a is blanket roll 13. Was transferred to the surface of the silicone rubber sheet 13a. Next, the blanket roll 13 is rotated in a state of being pressed against the glass substrate 14, and the printing ink composition 11 having a predetermined pattern is transferred to the surface of the glass substrate 14 by rolling on the glass substrate 14. A coating film of a printing ink composition having a desired pattern was formed. Further, the glass substrate 14 after printing is dried at 150 ° C. for 5 minutes in the air, then heated to 560 ° C. at a rate of 10 ° C./min in the air, and kept at 560 ° C. for 10 minutes for coating. The film was baked. By passing through the above process, the glass substrate in which the electrode was formed on the surface was produced. This glass substrate was referred to as Example 1.

<Example 2>
A glass substrate having an electrode formed on the surface was prepared in the same manner as in Example 1 except that a hydrogenated bisphenol F type resin obtained by hydrogenating a bisphenol F type epoxy resin was used as the resin component. . This glass substrate was referred to as Example 2. The aromatic component contained in the hydrogenated bisphenol F type epoxy resin was 0.4 parts by weight.
<Example 3>
A glass substrate having an electrode formed on the surface was prepared in the same manner as in Example 1 except that a hydrogenated styrene resin obtained by hydrogenating a styrene resin was used as the resin component. This glass substrate was referred to as Example 3. The aromatic component contained in the hydrogenated styrene resin was 0.2 parts by weight.

<Comparative Example 1>
A glass substrate having an electrode formed on the surface was prepared in the same manner as in Example 1 except that a styrene resin was used as the resin component. This glass substrate was designated as Comparative Example 1. The aromatic component contained in the styrene resin was 100 parts by weight.
<Comparative example 2>
A glass substrate having an electrode formed on the surface was prepared in the same manner as in Example 1 except that the aromatic component contained in the hydrogenated bisphenol A type epoxy resin was 1.0 part by weight. This glass substrate was designated as Comparative Example 2.
<Comparative Example 3>
A glass substrate having an electrode formed on the surface was prepared in the same manner as in Example 1 except that an acrylic resin was used as the resin component. This glass substrate was designated as Comparative Example 3. In addition, the aromatic component contained in an acrylic resin was 0 weight part.

<Comparative test 1 and evaluation>
While measuring the specific resistance of the electrode formed on the glass substrate of Examples 1-3 and Comparative Examples 1-3, the printability of these electrodes was evaluated. The specific resistance of the electrode was measured with a Lorester (Mitsubishi Chemical Corporation). In addition, the printability of the electrodes is determined by measuring the line widths of nine locations at predetermined positions on each substrate, and the maximum and minimum values of the above measured values are within ± 2 μm with respect to the line width of the concave pattern of the planar intaglio. The time was set as “good”, and the time when it exceeded ± 2 μm was set as “bad”. The results are shown in Table 1 below.

  As is clear from Table 1, the electrode of Comparative Example 1 using a styrene resin which is an aromatic resin as the resin component, or the electrode of Comparative Example 2 containing 1.0 part by weight of the aromatic component in the resin component is printed. In the electrode of Comparative Example 3 using an acrylic resin that does not contain any aromatic component as a resin component, the specific resistance was increased to 10.5 μΩ · cm and 5.2 μΩ · cm, respectively. Although the specific resistance was relatively good at 2.8 μΩ · cm, the printability was poor. On the other hand, by hydrogenating a resin component containing an aromatic component, a hydrogenated alicyclic resin component containing only 0.2 to 0.4 parts by weight of the aromatic component in the resin component is obtained. In the electrodes of Examples 1 to 3 used, the printability was good and the specific resistance was as small as 2.6 to 3.1 μΩ · cm. From the above, it was confirmed that a printing ink composition having both high-precision printability suitable for fine wiring and good electrical conductivity with small specific resistance was obtained. As in Examples 1 to 3, electrodes that are suitable for fine wiring and have a small specific resistance are optimal as bus electrodes for the front panel for PDP and address electrodes for the rear panel for PDP.

It is the schematic of the intaglio offset printing method of embodiment of this invention.

Explanation of symbols

11 Ink composition for printing 14 Glass substrate (base material)

Claims (8)

In a printing ink composition comprising a mixture containing conductive metal powder, glass frit, resin component and solvent component, printed on a substrate in a desired pattern, dried and baked,
The resin component is an alicyclic resin component obtained by hydrogenating a resin containing an aromatic component,
The printing ink composition, wherein the aromatic component contained in the alicyclic resin component is 0.5 parts by weight or less.   The alicyclic resin component is one or two selected from the group consisting of hydrogenated styrene resin, hydrogenated bisphenol A type epoxy resin, hydrogenated bisphenol F type epoxy resin and long chain aliphatic diglycidyl ether The printing ink composition according to claim 1, wherein the printing ink composition is one or more resin components. Obtaining an alicyclic resin component having an aromatic component of 0.5 parts by weight or less by hydrogenating a resin containing the aromatic component;
A step of mixing the alicyclic resin component, conductive metal powder, glass frit and solvent component to prepare a printing ink composition. Printing the ink composition for printing according to claim 1 or 2 on a substrate in a desired pattern to form a coating film;
A method of forming an electrode for a plasma display panel, comprising: drying and baking the coating film to form an electrode. Printing the ink composition for printing produced by the method according to claim 3 in a desired pattern on a substrate to form a coating film;
A method of forming an electrode for a plasma display panel, comprising: drying and baking the coating film to form an electrode.   The electrode for plasma display panels formed using the ink composition for printing of Claim 1 or 2.   The electrode for plasma display panels formed using the manufacturing method of the printing ink composition of Claim 3.   The electrode for plasma display panels formed using the formation method of the electrode of Claim 4 or 5.

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