JP2009110948A - Ink composition for printing and method for forming black matrix and bus electrode of front plate for plasma display panel using the composition - Google Patents

Abstract

Provided is a printing ink composition capable of achieving both conductivity and blackness and capable of forming a black matrix and a bus electrode on a substrate with one kind of printing ink composition. To do.
An electrically conductive metal powder comprising a conductive metal powder, a black pigment powder, a glass frit, a resin component, a solvent component, and a dispersant, and the conductive metal powder is a non-spherical anisotropic conductive metal powder 33. The average value of the maximum length of the conductive metal powder 33 is 30 μm or less, the average value of the minimum length is 0.05 to 2 μm, and the average value of the aspect ratio of the anisotropic conductive metal powder 33 is 1. / 2 or less.
[Selection] Figure 1

Description

  The present invention relates to a printing ink composition that can be used for forming a black matrix or a bus electrode of a front plate for a plasma display panel (hereinafter referred to as PDP), and a PDP using the composition. The present invention relates to a method of forming a black matrix and a bus electrode on a front plate, and a fired body formed by this method.

  In recent years, a PDP attracting attention as a large color display is composed of a front plate and a back plate used as a display unit. In the front plate, a black matrix is formed on the transparent electrode of the front plate in order to increase display contrast.

  Also, the pattern of the bus electrode is prepared by applying a black photosensitive paste to the entire surface of the front plate, further adjusting the photosensitive silver paste to a predetermined thickness, drying it, It is formed by photolithography that exposes and develops according to the shape of the pattern (see, for example, Patent Document 1).

Further, when forming the front plate electrode for PDP by the intaglio offset printing method, using a transfer body in which the surface rubber layer is made of silicone rubber, (1) with black ink containing black metals on a transparent substrate A step of pattern printing, and (2) a step of laminating and printing a conductive metal ink on the black ink pattern, and (3) a step of firing the layered and printed ink pattern at 500 ° C. or higher, Before the PDP, wherein the black ink contains the resin (A) and the silicone oil (B) in a ratio of 3 to 50 parts by weight of (B) with respect to 100 parts by weight of (A). A method for manufacturing a face plate has been proposed (see, for example, Patent Document 2).
JP 2003-151450 A ([0040] to [0047]) JP 2004-362830 A (Claim 1)

  The reason why the two types of pastes are required to be applied to the bus electrode is that the black photosensitive paste can make the bus electrode black enough, but the conductivity is insufficient, whereas the photosensitive silver paste This is because although it is possible to make the conductivity good, it is difficult to achieve both good conductivity and sufficient blackness, such as insufficient blackness.

  In the photolithography method as described in Patent Document 1, most of the black paste and silver paste applied to the entire surface of the front plate are washed and removed after the exposure / development process, which is problematic in terms of material utilization efficiency. There is. In addition, since it is necessary to repeat the processes such as coating, exposure, and development in each of the black photosensitive paste and the photosensitive silver paste, a large cost is required for manufacturing the bus electrode.

  Moreover, regarding the electrode forming method by the intaglio offset printing method as in Patent Document 2, the problem of material utilization efficiency can be cleared, but black ink and conductive metal ink need to be printed twice at a time. There is still a problem in terms of production efficiency.

  The objective of this invention is providing the ink composition for printing which can improve blackness, without impairing electroconductivity.

  Another object of the present invention is to provide a printing ink composition that can be commonly used for forming a black matrix and a bus electrode.

  Still another object of the present invention is to provide a method for forming a black matrix and a bus electrode of a PDP front plate using the above printing ink composition, and a fired body formed by this method.

  According to the first aspect of the present invention, a plasma display is formed by printing on a transparent electrode provided on the surface of a transparent substrate to form a coating film having a desired printing pattern, and drying and baking the coating film having the formed printing pattern. A printing ink composition for forming a black matrix and a bus electrode of a front plate for a panel, the composition comprising a conductive metal powder, a black pigment powder, a glass frit, a resin component, a solvent component, and a dispersant. The conductive metal powder is a non-spherical anisotropic conductive metal powder, the average value of the maximum length of the anisotropic conductive metal powder is 30 μm or less, and the average value of the minimum length is 0.05. The printing ink composition is characterized in that the average aspect ratio of the anisotropic conductive metal powder is ½ μm or less.

  The invention according to claim 2 is the invention according to claim 1, which is an ink composition for offset printing having a viscosity of 1 to 10 Pa · s.

  The invention according to claim 3 is the ink composition for screen printing according to claim 1, which has a viscosity of 10 to 1000 Pa · s.

  The invention according to claim 4 forms the coating film of the printing pattern by printing the printing ink composition according to any one of claims 1 to 3 on the transparent electrode provided on the surface of the transparent substrate, A method for forming a black matrix and a bus electrode of a front plate for a plasma display panel, wherein the formed coating film of the printed pattern is dried and fired.

  The invention according to claim 5 is the invention according to claim 4, wherein printing when forming a coating film is performed by an offset printing method using a printing ink composition having a viscosity of 1 to 10 Pa · s. This is a method of forming a black matrix and a bus electrode of a front panel for a plasma display panel.

  The invention according to claim 6 is the invention according to claim 4, wherein printing when forming the coating film is performed by a screen printing method using a printing ink composition having a viscosity of 10 to 1000 Pa · s. This is a method of forming a black matrix and a bus electrode of a front panel for a plasma display panel.

  The invention according to claim 7 is a fired body formed by the method according to any one of claims 4 to 6.

  According to the present invention, the conductive metal powder is a non-spherical anisotropic conductive metal powder comprising a conductive metal powder, a black pigment powder, a glass frit, a resin component, a solvent component, and a dispersant, and is anisotropic. The average value of the maximum length of the conductive conductive metal powder is 30 μm or less, the average value of the minimum length is 0.05 to 2 μm, and the average value of the aspect ratio of the anisotropic conductive metal powder is 1 / It is possible to collectively form a black matrix and bus electrodes that achieve both conductivity and blackness by pattern printing a printing ink composition of 2 or less on a substrate, drying, and firing. Become. Furthermore, this invention can provide the method of forming the black matrix and bus electrode of the front plate for PDP using this printing ink composition, and the fired body formed by this method.

  Next, the best mode for carrying out the present invention will be described with reference to the drawings.

  The printing ink composition of the present invention is printed on a transparent electrode provided on the surface of a transparent substrate to form a coating film having a desired printing pattern, and after the coating film having the formed printing pattern is dried, printing is performed. It is a composition for firing a coating film of a pattern to form a black matrix and a bus electrode of a front panel for a plasma display panel.

  The printing ink composition includes a powder component composed of pigment powder and glass frit, a resin component, a solvent component, and a dispersant. The pigment powder is composed of a conductive metal powder and a black pigment powder. When the conductive metal powder is 100 parts by mass, the pigment powder is preferably blended so that the black pigment powder has a ratio of 2 to 50 parts by mass. -20 mass parts is more preferable. It is preferable to mix so that the glass frit is 5 to 30 parts by mass with respect to 100 parts by mass of the conductive metal powder, and more preferably 10 to 20 parts by mass. About the ratio of a resin component and a solvent component, when making a resin component into 100 mass parts, it is preferable to mix | blend so that a solvent component may be a ratio of 30-200 mass parts, and also 50-100 mass parts is more preferable. When the total amount of the pigment powder is 100 parts by mass, it is preferably blended so that the total of the resin component and the solvent component is 20 to 200 parts by mass, and more preferably 30 to 100 parts by mass. Moreover, 2-30 mass parts is preferable and, as for the compounding quantity of a dispersing agent, when the sum total of a pigment powder is 100 mass parts, 3-20 mass parts is more preferable.

  The conductive metal powder contained in the printing ink composition of the present invention is an anisotropic conductive metal powder having a non-spherical conductive metal powder.

  FIG. 2 is a diagram schematically showing the internal structure of a fired body formed of a printing ink composition using a conventional spherical conductive metal powder. In FIG. 2, components other than the conductive metal powder and the black pigment powder are omitted. FIG. 1 is a diagram schematically showing the internal structure of a fired body formed of a printing ink composition using the anisotropic conductive metal powder of the present invention. In FIG. 1, components other than the anisotropic conductive metal powder and the black pigment powder are omitted. The fired bodies shown in FIGS. 1 and 2 are used as a black matrix and a bus electrode of a PDP front plate.

  In a fired body formed using a conventional printing ink composition, as shown in FIG. 2, since spherical conductive metal powder 31 is used, this spherical conductive metal powder 31 and black pigment powder 32 are used. Depending on the particle size, contact between the spherical conductive metal powders 31 is greatly hindered, making it difficult to obtain high conductivity. In the present invention, since the non-spherical anisotropic conductive metal powder is used, as shown in FIG. 1, the anisotropic conductive metal powders 33 are bridged to form the metal powder by the black pigment powder 32. While avoiding the contact obstruction between 33, high electrical conductivity is obtained because the metal powder 33 is in good contact.

  The specific shape of the non-spherical anisotropic conductive metal powder of the present invention is not particularly limited, and examples thereof include a planar shape, a needle shape, a plate shape, a rod shape, and a spindle shape. Of these, a planar or plate-like shape is particularly preferable. This is because the planar or plate-like shape is higher in conductivity because the contact area between the conductive metal powders is wider than that of, for example, the needle-like and bar-like shapes.

  The anisotropic conductive metal powder contained in the printing ink composition of the present invention has an average maximum length of 30 μm or less, an average minimum length of 0.05 to 2 μm, and is anisotropic. The average aspect ratio of the conductive conductive metal powder is 1/2 or less.

  The specific definition that the maximum length, the average value of the minimum length, and the aspect ratio of the anisotropic conductive metal powder show the above range is an electron microscope such as SEM (Scanning Electron Microscope). The maximum length and the minimum length of each of the 500 or more anisotropic conductive metal powders contained in the printing ink composition are measured, and the respective average values satisfy the above range, and each anisotropic The aspect ratio (minimum length / maximum length) of the conductive metal powder is measured, and the average value satisfies the above range. The minimum length when the anisotropic conductive metal powder is planar means the minimum length excluding the thickness. The reason why the average value of the maximum length is 30 μm or less is that when it exceeds 30 μm, the dispersibility is deteriorated, and the conductivity and the blackness are lowered. In addition, the average value of the minimum length is within the above range because if the average value of the minimum length is less than the lower limit value, the effect of improving the conductivity cannot be obtained. This is because the black color of the matrix is hindered by the conductive metal powder, resulting in a problem that the blackness is lowered. Furthermore, the average value of the aspect ratio of the anisotropic conductive metal powder was set to 1/2 or less because when the average value of the aspect ratio exceeds 1/2, the shape of the powder becomes closer to the spherical shape conventionally used. This is because the effect of improving conductivity cannot be obtained.

  Examples of the anisotropic conductive metal powder include silver powder, copper powder, aluminum powder, gold powder, and nickel powder.

  An anisotropic conductive metal powder can be manufactured by the following methods, for example, when this is a silver powder. An aqueous solution A in which silver nitrate is dissolved in pure water and a liquid B in which L-ascorbic acid is dissolved in pure water are prepared. An aqueous solution of ammonium polyacrylate is added to and mixed with the B liquid. The liquid A and liquid B are injected and mixed at a time in a beaker rotating with a stirrer to cause a reaction. This stirring is continued for several minutes to precipitate silver powder. The produced silver powder is washed several times with water to remove impurities, dehydrated with isopropanol and dried to obtain anisotropic silver powder.

  As the black pigment powder, it is preferable to use a powder having an average particle diameter of 0.01 to 0.5 μm. When the average particle diameter of the black pigment powder is less than the lower limit, the black color tends to be lowered because the black color development of the black matrix is inhibited by the anisotropic conductive metal powder. If the average particle size of the black pigment powder exceeds the upper limit, the conductivity tends to decrease due to the black pigment powder inhibiting the contact between the anisotropic conductive metal powders in the coated film after printing. . Among these, it is particularly preferable to use a powder having an average particle size of 0.03 to 0.2 μm. As the black pigment powder, a composition comprising a metal oxide containing one or more metal elements selected from the group consisting of Co, Cr, Cu, Mn, Ru, Fe and Ni, or a composite oxide thereof. Is mentioned.

  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 0.1 to 1.0 μm.

The average particle size of the glass frit and black pigment powder used in the present invention was measured according to JIS R 1629 using a laser diffraction / scattering particle size distribution measuring device (LA-910, manufactured by Horiba, Ltd.). The 50% diameter value (D ₅₀ ) in the volume-based integrated fraction.

  A synthetic resin is mentioned as a resin component. This synthetic resin is not particularly limited as long as it is not carbonized during firing, and specifically, epoxy resin, cellulose resin, urethane resin, butyral resin, acrylic resin, polyester resin, styrene Resins, phenol resins, and the like can be used, and even resins obtained by mixing a plurality of these resins to undergo a crosslinking reaction can be used.

  The solvent component is not particularly limited as long as it is an organic solvent capable of dissolving the resin component. Specifically, alcohol solvents, ketone solvents, ether solvents, carbitol solvents, hydrocarbon solvents. Diol-based solvents, glycol-based solvents, glycol ether-based solvents and the like, and a solvent obtained by mixing a plurality of these solvents can also be used.

  As the dispersant, higher fatty acids are preferred. The length of the fatty chain of the higher fatty acid is not particularly limited, but is preferably C8 or more. Further, dicarboxylic acids in which the terminal functional group of the higher fatty acid has two carbonyl groups are more preferred. This is because the presence of two carbonyl groups improves the dispersibility of the conductive metal powder and the black pigment in the printing ink composition.

  The method for forming the black matrix and the bus electrode of the front plate for PDP of the present invention is to apply the above-mentioned printing ink composition of the present invention on the transparent electrode provided on the surface of the transparent substrate and apply a desired print pattern. A film is formed, and the coating film of the formed printed pattern is dried and baked. Printing is performed by adjusting the viscosity of the printing ink composition according to the printing method. When printing by the offset printing method when forming a coating film, it is preferable to use a printing ink composition prepared so that the viscosity is 1 to 10 Pa · s, preferably 2 to 8 Pa · s. . Also, when printing is performed by screen printing to form a coating film, it is preferable to use a printing ink composition prepared so that the viscosity is 10 to 1000 Pa · s, preferably 100 to 500 Pa · s. It is. Here, in this specification, the viscosity is a value at a rotational speed of 5 rpm measured according to JIS K 5600-2-3 using a rotary cone / plate viscometer (ELD / EMD / EHD manufactured by Tokimec Co., Ltd.). Say.

  A method of forming an electrode for PDP by printing on a glass substrate having a transparent electrode by an intaglio offset printing method using a printing ink composition prepared so that the viscosity is in the range of 1 to 10 Pa · s and baking it. Will be explained.

  First, as shown in FIG. 3A, 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. 3B, 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 planar 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 about 50 to 60%, although it varies depending on the concave pattern of the plane intaglio, the components and ratios contained in the ink composition, or the pressure of the blanket. Next, as shown in FIG. 3 (c), the blanket roll 13 to which the printing ink composition 11 has been transferred is pressed against a glass substrate 14 (transfer object) having a transparent electrode, and the blanket roll 13 is rotated in this state. By rolling on the glass substrate 14 having a transparent electrode, the printing ink composition 11 is transferred in a predetermined pattern onto the surface of the glass substrate 14 having a transparent electrode, thereby forming a coating film having a desired printing pattern. (FIG. 3 (d)). In FIG. 3, the transparent electrode formed on the glass substrate is not shown.

  Furthermore, after drying the glass substrate 14 on which the coating film of this desired printing pattern was formed at 100 to 200 ° C. for 1 to 30 minutes in the air, the heating rate was 6 to 12 ° C./min in the air. Preferably, the firing is performed at a temperature of 8 to 10 ° C./min, 500 to 600 ° C., preferably 540 to 580 ° C. The firing temperature holding time is preferably 5 to 30 minutes, more preferably 10 to 20 minutes.

  As described above, the PDP electrode is formed through the steps of FIGS. 3A to 3D. A black matrix for PDP is formed through the same process.

  The fired body formed in this way has a black matrix and a bus electrode integrated as compared with a fired body formed by a conventional technique, which simplifies the manufacturing process and is excellent in manufacturing cost. .

  Next, using the printing ink composition prepared so that the viscosity is in the range of 10 to 1000 Pa · s, printing is performed on a glass substrate having a transparent electrode by a screen printing method, and baking is performed to form an electrode for PDP. A method will be described.

  First, the screen plate 21 is stretched on the screen frame 22, and the screen plate 21 is fixed in a tensioned state, and a predetermined amount of a printing ink composition 23 is supplied onto the surface of the screen plate 21 as shown in FIG. . Next, as shown in FIG. 4B, the printing ink composition 23 is embedded in the slit 21a by sliding the scraper 24 in the direction opposite to the printing operation direction shown in FIGS. . Next, as shown in FIG. 4 (c), after the squeegee 25 is placed on the surface of the screen plate 21, as shown in FIGS. 4 (d) and (e), the surface of the screen plate 21 with the squeegee 25 pressurized. The printing ink composition 23 embedded in the slits 21a is slid onto the glass substrate (transfer object) 20 having a transparent electrode. In FIG. 4, the transparent electrode formed on the glass substrate is not shown. As shown in FIG. 4E, the printing ink composition 23 embedded in the slit 21a is discharged when the squeegee 25 passes through the slit 21a of the screen plate 21, and is transferred to the glass substrate 20 having a transparent electrode. Is done. In this way, the printing ink composition 23 is transferred in a predetermined pattern onto the surface of the glass substrate 20 having a transparent electrode, thereby forming a coating film 26 having a desired printing pattern (FIG. 4F).

  Furthermore, after drying the glass substrate 20 on which the coating film of this desired printing pattern was formed at 100 to 200 ° C. for 1 to 30 minutes in the air, the heating rate was 6 to 12 ° C./min in the air. Preferably, the firing is performed at a temperature of 8 to 10 ° C./min, 500 to 600 ° C., preferably 540 to 580 ° C. The firing temperature holding time is preferably 5 to 30 minutes, more preferably 10 to 20 minutes.

  As described above, the PDP electrode is formed through the steps shown in FIGS. 4A to 4F. A black matrix for PDP is formed through the same process.

  The fired body formed in this way has a black matrix and a bus electrode integrated as compared with a fired body formed by a conventional technique, which simplifies the manufacturing process and is excellent in manufacturing cost. .

  Next, examples of the present invention will be described in detail together with comparative examples.

<Example 1>
An anisotropic silver powder having an average maximum length of 3 μm and an average minimum length of 0.1 μm, that is, an average aspect ratio of 1/30, as a conductive metal powder is black Black pigments (composition ratio, Mn: Cu: Fe = 35: 25: 8.3), which are composite oxides of spherical Mn, Cu and Fe with an average particle diameter of 0.2 μm, are prepared as pigment powders, respectively. did. Further, a bismuth oxide-boron oxide glass frit having a softening point of 400 ° C. was prepared as a glass frit. An acrylic resin was prepared as a resin component, and a glycol ether solvent was prepared as a solvent component. Further, stearic acid, which is a higher fatty acid, was prepared as a dispersant.

  60 parts by mass of the silver powder, 6 parts by mass of the black pigment powder, 10 parts by mass of the glass frit, 15 parts by mass of the acrylic resin, 8 parts by mass of the glycol ether solvent, and 6 parts by mass of the dispersant are mixed, and this mixture is mixed with the planetary mixer. Was then dispersed for 30 minutes, and further dispersed for 3 minutes using a three-roll mill to prepare a paste-like printing ink composition. At this time, the viscosity of the obtained printing ink composition was 5 Pa · s.

  On the other hand, as shown in FIG. 3, a planar intaglio plate 10 having a plurality of concave patterns with a line width of 150 μm, a depth of 30 μm, and a pitch of 300 μm is prepared as a printing plate used in the intaglio offset printing method, and a thickness of 2. A glass substrate 14 (front electrode substrate: PD200 manufactured by Asahi Glass Co., Ltd.) of 8 mm and diagonal 50 inches was prepared. Further, a blanket roll 13 having a thickness of 700 μm on the surface as a printing blanket and attached with a silicone rubber sheet (room temperature curing type silicone rubber (additional type)) having a hardness of 40 (JIS K 6253 type A) is attached. Using.

  First, a predetermined amount of the above-mentioned printing ink composition 11 was supplied to the surface of the planar intaglio 10, and the printing ink composition 11 was embedded in the concave pattern 10 a of the planar intaglio 10 using a SUS squeegee 12. Next, the blanket roll 13 is rotated in a state of being pressed onto the flat intaglio 10 and is rolled on the flat intaglio 10 so that a part of the printing ink composition 11 embedded in the concave pattern 10 a is transferred to the blanket roll 13. 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 having a transparent electrode, and is rolled on the glass substrate 14 having the transparent electrode, whereby a predetermined pattern is formed on the surface of the glass substrate 14 having the transparent electrode. The printing ink composition 11 was transferred to form a coating film of the printing ink composition having a desired pattern.

  Next, the glass substrate 14 after printing was dried at 150 ° C. for 5 minutes in the air. After this drying, the temperature was raised to 560 ° C. in air at a temperature rising rate of 10 ° C./min, and then held at 560 ° C. for 10 minutes. By passing through the above process, the glass substrate in which the electrode was formed on the surface was produced.

<Example 2>
An anisotropic silver powder having an average maximum length of 1 μm and an average minimum length of 0.5 μm, that is, an average aspect ratio of 1/2, is black A glass substrate having an electrode formed on the surface thereof was prepared in the same manner as in Example 1 except that a black pigment powder having an average particle diameter of 0.1 μm was used as the pigment powder and a printing ink composition was prepared.

<Example 3>
An anisotropic silver powder having an average maximum length of 5 μm and an average minimum length of 0.2 μm, that is, an average aspect ratio of 1/25 as a conductive metal powder is black. A glass substrate having an electrode formed on the surface was prepared in the same manner as in Example 1 except that a black pigment powder having an average particle diameter of 0.05 μm was used as the pigment powder to prepare a printing ink composition.

<Example 4>
An anisotropic silver powder having an average value of the maximum length of 30 μm and an average value of the minimum length of 0.3 μm, that is, an average aspect ratio of 1/100 is used as the conductive metal powder. A glass substrate having an electrode formed on the surface was prepared in the same manner as in Example 1 except that the printing ink composition was prepared.

<Example 5>
An anisotropic silver powder having an average value of the maximum length of 4 μm and an average value of the minimum length of 0.1 μm, that is, an average aspect ratio of 1/40 as a conductive metal powder is black. A glass substrate having an electrode formed on the surface was prepared in the same manner as in Example 1 except that a black pigment powder having an average particle size of 0.5 μm was used as the pigment powder to prepare a printing ink composition.

<Comparative Example 1>
A spherical silver powder having an average maximum length of 0.6 μm and an average minimum length of 0.6 μm, that is, an average aspect ratio of 1/1, is black as a conductive metal powder. A glass substrate having an electrode formed on the surface thereof was prepared in the same manner as in Example 1 except that a black pigment powder having an average particle diameter of 0.1 μm was used as the pigment powder and a printing ink composition was prepared.

<Comparative example 2>
An anisotropic silver powder having an average maximum length of 40 μm and an average minimum length of 0.5 μm, that is, an average aspect ratio of 1/80 as a conductive metal powder is black. A glass substrate having an electrode formed on the surface thereof was prepared in the same manner as in Example 1 except that a black pigment powder having an average particle diameter of 0.1 μm was used as the pigment powder and a printing ink composition was prepared.

<Comparative Example 3>
Printing using an anisotropic silver powder having an average maximum length of 30 μm and an average minimum length of 3 μm, that is, an average aspect ratio of 1/10 as the conductive metal powder A glass substrate having an electrode formed on the surface thereof was prepared in the same manner as in Example 1 except that the ink composition was prepared.

<Comparative example 4>
An anisotropic silver powder having an average maximum length of 1 μm and an average minimum length of 0.01 μm, that is, an average aspect ratio of 1/100, is black as a conductive metal powder. A glass substrate having an electrode formed on the surface thereof was prepared in the same manner as in Example 1 except that a black pigment powder having an average particle diameter of 0.1 μm was used as the pigment powder and a printing ink composition was prepared.

<Evaluation 1>
About the electrode on the glass substrate obtained in Examples 1-5 and Comparative Examples 1-4, resistance was measured with the Lorester (made by Mitsubishi Chemical Corporation). The blackness of the electrode was evaluated by measuring the L value (lightness) with a color computer (manufactured by Suga Test Instruments Co., Ltd.). In addition, the measured value of L value shows that the lightness is so low that a numerical value is small, ie, it is closer to black. The results are shown in Table 1 below.

表１から明らかなように、導電性金属粉末が異方性導電性金属粉末であり、最大長さの平均値が３０μｍ以下であり、最小長さの平均値が０．０５〜２μｍであり、かつ異方性導電性金属粉末のアスペクト比の平均値が１／２以下である実施例１〜５では、従来技術の印刷用インキ組成物に使用されていた球状の導電性金属粉末を使用した比較例１に比べ、導電性及び黒色度ともに優れた結果が得られた。最大長さの平均値が３０μｍを越える比較例２では分散性が悪く、導電性及び黒色度が低下した。また最小長さの平均値が２μｍを越える比較例３では高い導電性は得られたものの、Ｌ値が高くなり黒色度が低下した。一方、最小長さの平均値が０．０５μｍ未満の比較例４では十分な黒色度は得られたものの、導電性が低下した。このことから、異方性導電性金属粉末が、最大長さの平均値が３０μｍ以下であり、最小長さの平均値が０．０５〜２μｍであり、かつ異方性導電性金属粉末のアスペクト比の平均値が１／２以下とすることで、本発明の効果が得られることが確認された。

As is clear from Table 1, the conductive metal powder is an anisotropic conductive metal powder, the average value of the maximum length is 30 μm or less, the average value of the minimum length is 0.05 to 2 μm, In Examples 1 to 5 in which the average value of the aspect ratio of the anisotropic conductive metal powder was 1/2 or less, the spherical conductive metal powder used in the printing ink composition of the prior art was used. Compared to Comparative Example 1, excellent results were obtained in both conductivity and blackness. In Comparative Example 2 in which the average value of the maximum length exceeded 30 μm, the dispersibility was poor and the conductivity and the blackness were lowered. In Comparative Example 3 in which the average value of the minimum length exceeded 2 μm, high conductivity was obtained, but the L value increased and the blackness decreased. On the other hand, in Comparative Example 4 in which the average value of the minimum length was less than 0.05 μm, sufficient blackness was obtained, but the conductivity was lowered. From this, the anisotropic conductive metal powder has an average value of the maximum length of 30 μm or less, an average value of the minimum length of 0.05 to 2 μm, and an aspect of the anisotropic conductive metal powder. It was confirmed that the effect of the present invention can be obtained by setting the average value of the ratio to ½ or less.

<Example 6>
An electrode was formed on the surface in the same manner as in Example 1 except that 10 parts by mass of the acrylic resin and 10 parts by mass of the glycol ether solvent were used to prepare the printing ink composition so that the viscosity was 2 Pa · s. A glass substrate was produced.

<Example 7>
A glass substrate having an electrode formed on the surface thereof was prepared in the same manner as in Example 1 except that the printing ink composition was prepared so that the viscosity was 8 Pa · s with 6 parts by mass of the glycol ether solvent.

<Example 8>
An electrode was formed on the surface in the same manner as in Example 1 except that 5 parts by mass of the acrylic resin and 10 parts by mass of the glycol ether solvent were used to prepare the printing ink composition so that the viscosity was 1 Pa · s. A glass substrate was produced.

<Example 9>
A glass substrate having an electrode formed on the surface was prepared in the same manner as in Example 1 except that the printing ink composition was prepared so that the viscosity was 10 Pa · s with 5 parts by weight of the glycol ether solvent.

<Comparative Example 5>
An electrode is formed on the surface in the same manner as in Example 1 except that the ink composition for printing is prepared so that the viscosity is 0.8 Pa · s with 8 parts by mass of the acrylic resin and 16 parts by mass of the glycol ether solvent. A glass substrate was prepared.

<Comparative Example 6>
An electrode was formed on the surface in the same manner as in Example 1 except that 12 parts by mass of the acrylic resin and 4 parts by mass of the glycol ether solvent were used to prepare the printing ink composition so that the viscosity was 15 Pa · s. A glass substrate was produced.

<Evaluation 2>
About the electrode on the glass substrate obtained in Example 1, Examples 6-9 and Comparative Examples 5 and 6, the printability by the intaglio offset printing method was evaluated.

  The specific evaluation method of printability measured the line width of nine places in the predetermined position of each board | substrate about the printing line formed in the surface of the glass substrate after baking, respectively. Among the measured values of the line widths at these nine locations, when the maximum value and the minimum value are both within the range of ± 2 μm with respect to the line width of 150 μm of the concave pattern of the planar intaglio, When one or both of the minimum values exceed the range of ± 2 μm and both the maximum value and the minimum value are within the range of ± 5 μm, it is defined as “good”, and one or both of the maximum or minimum values are ± 5 μm When the range was exceeded, it was determined as “bad”. The maximum value and the minimum value in printability in Table 2 are shown by the difference with respect to the line width of 150 μm of the plane intaglio printing pattern. For example, “+1.0” is measured data is 151.0 μm, and “−0.2” is 149.8 μm.

表２から明らかなように、印刷用インキ組成物の粘度が１〜１０Ｐａ・ｓの範囲である実施例１及び実施例６，７では、上記最大値及び最小値の双方が平面凹版の凹状パターンのライン幅１５０μｍに対して±２μｍの範囲内となり、また実施例８，９では、上記最大値又は最小値の一方或いは双方が平面凹版の凹状パターンのライン幅１５０μｍに対して±２μｍ範囲の範囲を超え、かつ上記最大値及び最小値の双方が±５μｍの範囲内となり、凹版オフセット印刷法による印刷性において優れた結果が得られた。一方、印刷用インキ組成物の粘度が１Ｐａ・ｓ未満である比較例５、及び印刷用インキ組成物の粘度が１０Ｐａ・ｓを越える比較例６では、上記最大値又は最小値の一方或いは双方が平面凹版の凹状パターンのライン幅１５０μｍに対して±５μｍの範囲を越え、凹版オフセット印刷法による印刷性が不良となった。このことから、塗膜を形成する際の印刷をオフセット印刷法により行う場合には、粘度が１〜１０Ｐａ・ｓになるように調製した印刷用インキ組成物を使用することが好適であることが確認された。

As is apparent from Table 2, in Example 1 and Examples 6 and 7 in which the viscosity of the printing ink composition is in the range of 1 to 10 Pa · s, both the maximum value and the minimum value are concave intaglio patterns. Within the range of ± 2 μm with respect to the line width of 150 μm, and in Examples 8 and 9, one or both of the maximum value and the minimum value are within the range of ± 2 μm with respect to the line width of 150 μm of the concave indentation pattern And both the maximum value and the minimum value are in the range of ± 5 μm, and excellent results were obtained in printability by the intaglio offset printing method. On the other hand, in Comparative Example 5 in which the viscosity of the printing ink composition is less than 1 Pa · s and in Comparative Example 6 in which the viscosity of the printing ink composition exceeds 10 Pa · s, one or both of the maximum value and the minimum value are The range of ± 5 μm was exceeded with respect to the line width of 150 μm of the concave pattern of the planar intaglio, and the printability by the intaglio offset printing method was poor. From this, when printing by the offset printing method is performed when forming the coating film, it is preferable to use a printing ink composition prepared so that the viscosity is 1 to 10 Pa · s. confirmed.

<Example 10>
An anisotropic silver powder having an average maximum length of 3 μm and an average minimum length of 0.1 μm, that is, an average aspect ratio of 1/30, as a conductive metal powder is black Black pigments (composition ratio, Mn: Cu: Fe = 35: 25: 8.3), which are composite oxides of spherical Mn, Cu and Fe with an average particle diameter of 0.2 μm, are prepared as pigment powders, respectively. did. Further, a bismuth oxide-boron oxide glass frit having a softening point of 400 ° C. was prepared as a glass frit. Moreover, ethyl cellulose resin was prepared as a resin component, and α-terpineol was prepared as a solvent component. Further, stearic acid, which is a higher fatty acid, was prepared as a dispersant.

  50 parts by mass of the above silver powder, 5 parts by mass of black pigment powder, 10 parts by mass of glass frit, 10 parts by mass of ethyl cellulose resin, 7 parts by mass of α-terpineol, and 5 parts by mass of a dispersant are mixed, and this mixture is mixed with a planetary mixer. After using and dispersing for 30 minutes, a paste-like printing ink composition was prepared by further dispersing for 3 minutes using a three-roll mill. At this time, the viscosity of the obtained printing ink composition was 330 Pa · s.

  On the other hand, MT-320 manufactured by Microtech Co., Ltd. was prepared as a screen printing machine, and a polyester screen plate having a surface mesh having a plurality of patterns with a line width of 150 μm and a pitch of 300 μm was prepared as a printing plate. Further, a glass substrate having a thickness of 2.8 mm and a diagonal of 50 inches (front side electrode substrate manufactured by Asahi Glass Co., Ltd .: PD200) was prepared as a transfer target.

  First, a predetermined amount of the printing ink composition was supplied onto the screen plate surface, and the scraper was slid on the screen plate surface to embed the printing ink composition in the slit. Next, the squeegee was placed on the surface of the screen plate, and the squeegee was slid on the surface of the screen plate under pressure, whereby the printing ink composition embedded in the slit was transferred to the glass substrate having a transparent electrode. In this manner, the printing ink composition was transferred in a predetermined pattern onto the surface of the glass substrate having the transparent electrode, thereby forming a coating film having a desired printing pattern.

  Next, the glass substrate after printing was dried in air at 150 ° C. for 5 minutes. After this drying, the temperature was raised to 560 ° C. in air at a temperature rising rate of 10 ° C./min, and then held at 560 ° C. for 10 minutes. By passing through the above process, the glass substrate in which the electrode was formed on the surface was produced.

<Example 11>
A glass substrate having an electrode formed on the surface was prepared in the same manner as in Example 10 except that the printing ink composition was prepared so that the viscosity was 110 Pa · s as 10 parts by mass of α-terpineol.

<Example 12>
A glass substrate having an electrode formed on the surface was prepared in the same manner as in Example 10 except that the printing ink composition was prepared so that the viscosity was 490 Pa · s as 6 parts by mass of α-terpineol.

<Example 13>
A glass substrate having an electrode formed on the surface was prepared in the same manner as in Example 10 except that the printing ink composition was prepared so that the viscosity was 30 Pa · s as 15 parts by mass of α-terpineol.

<Example 14>
Glass with electrodes formed on the surface in the same manner as in Example 10 except that the printing ink composition was prepared so that the viscosity was 1000 Pa · s as 9 parts by mass of ethyl cellulose resin and 3 parts by mass of α-terpineol. A substrate was produced.

<Comparative Example 7>
Glass with electrodes formed on the surface in the same manner as in Example 10, except that the printing ink composition was prepared so that the viscosity was 9 Pa · s as 12 parts by mass of ethyl cellulose resin and 18 parts by mass of α-terpineol. A substrate was produced.

<Comparative Example 8>
A glass substrate having an electrode formed on the surface was prepared in the same manner as in Example 10 except that the printing ink composition was prepared so that the viscosity was 1150 Pa · s as 3 parts by mass of α-terpineol.

<Evaluation 3>
About the electrode on the glass substrate obtained in Examples 10-14 and Comparative Examples 7 and 8, the printability by the screen printing method was evaluated.

  The specific evaluation method of printability measured the line width of nine places in the predetermined position of each board | substrate about the printing line formed in the surface of the glass substrate after baking, respectively. Of these nine measured line widths, when both the maximum and minimum values are within the range of ± 2 μm for the screen plate slit line width of 150 μm, the value is “very good”. When one or both of the values exceed the range of ± 2μm and both the maximum value and the minimum value are within the range of ± 5μm, it is judged as “good”, and either the maximum value or the minimum value is within the range of ± 5μm When it exceeded the limit, it was defined as “bad”. The maximum value and the minimum value in printability in Table 3 are shown by the difference with respect to the line width of 150 μm of the slit of the screen plate. For example, “+1.4” has measurement data of 151.4 μm, and “−1.6” has measurement data of 148.4 μm.

表３から明らかなように、印刷用インキ組成物の粘度が１０〜１０００Ｐａ・ｓの範囲である実施例１０〜１２では、上記最大値及び最小値の双方がスクリーン版のスリットのライン幅１５０μｍに対して±２μｍの範囲内となり、また実施例１３，１４では、上記最大値又は最小値の一方或いは双方がスクリーン版のスリットのライン幅１５０μｍに対して±２μｍの範囲を越え、かつ上記最大値及び最小値の双方が±５μｍの範囲内となり、スクリーン印刷法による印刷性において優れた結果が得られた。一方、印刷用インキ組成物の粘度が１０Ｐａ・ｓ未満である比較例７、及び印刷用インキ組成物の粘度が１０００Ｐａ・ｓを越える比較例８では、上記最大値又は最小値の一方或いは双方がスクリーン版のスリットのライン幅１５０μｍに対して±５μｍを越え、スクリーン印刷法による印刷性が不良となった。このことから、塗膜を形成する際の印刷をスクリーン印刷法により行う場合には、粘度が１０〜１０００Ｐａ・ｓになるように調製した印刷用インキ組成物を使用することが好適であることが確認された。

As is clear from Table 3, in Examples 10 to 12 where the viscosity of the printing ink composition is in the range of 10 to 1000 Pa · s, both the maximum value and the minimum value are set to a line width of 150 μm of the slit of the screen plate. On the other hand, in Examples 13 and 14, one or both of the maximum value and the minimum value exceed the range of ± 2 μm with respect to the line width of 150 μm of the screen plate slit, and the maximum value described above. And the minimum value are both within the range of ± 5 μm, and excellent results were obtained in printability by the screen printing method. On the other hand, in Comparative Example 7 in which the viscosity of the printing ink composition is less than 10 Pa · s and in Comparative Example 8 in which the viscosity of the printing ink composition exceeds 1000 Pa · s, one or both of the maximum value and the minimum value are The screen width exceeded ± 5 μm with respect to the slit line width of 150 μm, and the printability by the screen printing method was poor. From this, when performing printing when forming a coating film by screen printing, it is preferable to use a printing ink composition prepared so that the viscosity is 10 to 1000 Pa · s. confirmed.

It is the figure which showed typically the internal structure of the baking body formed using the printing ink composition of this invention. It is the figure which showed typically the internal structure of the baking body formed using the conventional ink composition for printing. It is the schematic of the intaglio offset printing method of embodiment of this invention. It is the schematic of the screen printing method of embodiment of this invention.

Explanation of symbols

10 Plane intaglio (printing plate)
10a Concave pattern 11 Printing ink composition 12 Blanket roll (printing blanket)
13a Silicone rubber sheet (silicone sheet)
14 Glass substrate (transfer object)
20 Glass substrate (transfer object)
21 Screen 21a Slit 22 Screen frame 23 Ink composition for printing 24 Scraper 25 Squeegee 26 Printed coating 32 Black pigment powder 33 Anisotropic conductive metal powder

Claims (7)

Printing on the transparent electrode provided on the surface of the transparent substrate to form a coating film of a desired printing pattern, drying and baking the coating film of the formed printing pattern, and a black matrix of a front panel for a plasma display panel And a printing ink composition for forming a bus electrode,
The composition contains conductive metal powder, black pigment powder, glass frit, resin component, solvent component and dispersant,
The conductive metal powder is a non-spherical anisotropic conductive metal powder, the average value of the maximum length of the anisotropic conductive metal powder is 30 μm or less, and the average value of the minimum length is 0.00. An ink composition for printing, wherein the average value of the aspect ratio of the anisotropic conductive metal powder is 1/2 or less.   The ink composition for offset printing according to claim 1, which has a viscosity of 1 to 10 Pa · s.   The ink composition for screen printing according to claim 1, which has a viscosity of 10 to 1000 Pa · s.   A printing pattern coating film is formed by printing the printing ink composition according to any one of claims 1 to 3 on a transparent electrode provided on a surface of a transparent substrate, and the coating pattern coating pattern thus formed is formed. A method for forming a black matrix and a bus electrode on a front panel for a plasma display panel, wherein the substrate is dried and fired.   The black matrix and the bus electrode of the front plate for a plasma display panel according to claim 4, wherein printing when forming the coating film is performed by an offset printing method using a printing ink composition having a viscosity of 1 to 10 Pa · s. Forming method.   The black matrix and the bus electrode of the front plate for a plasma display panel according to claim 4, wherein printing when forming the coating film is performed by a screen printing method using a printing ink composition having a viscosity of 10 to 1000 Pa · s. Forming method.   A fired body formed by the method according to any one of claims 4 to 6.

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