JP5688217B2 - Paste composition and fired product pattern - Google Patents

Description

  The present invention relates to, for example, a paste composition used for producing a bus electrode of a plasma display panel and a fired product pattern obtained by firing a pattern of this paste composition.

  In a plasma display panel (hereinafter referred to as PDP), a black pigment is contained in a bus electrode and a black pattern formed on a front plate in order to improve contrast. For example, in a bus electrode having a two-layer structure, a black layer containing a black pigment as a lower layer and a white layer containing Ag or the like as an upper layer are formed on a transparent electrode such as ITO (Indium Tin Oxide).

  As the black pigment in such a black layer, generally used is an inorganic oxide such as carbon black, a copper / iron / manganese composite oxide, or cobalt trioxide. Of these, cobalt tetroxide does not exhibit redness or yellowness, that is, it is known that it is excellent in blackness, which is usually evaluated as an L value, and is stable even under severe use conditions (for example, , See Patent Document 1).

  However, cobalt trioxide has a high contact resistance value with a transparent electrode or a white layer, and there is a problem that power consumption increases particularly in a large-screen PDP. Furthermore, when a photosensitive resin or the like is added to form an electrode pattern to form a paste, there is a problem that the viscosity increases with time and it is difficult to store the paste composition for a long period of time.

JP 2003-138160 A (Claims etc.)

  INDUSTRIAL APPLICABILITY The present invention provides a paste composition that can form a black layer with good blackness and low contact resistance, can obtain good storage stability, and has good blackness and low contact resistance. It aims at providing the baked material pattern which can be used as a black layer.

  The paste composition of one embodiment of the present invention includes Mn, a black inorganic oxide containing a composite oxide of at least one of Fe and Sr, and an organic binder. With such a paste composition, a black layer with good blackness and low contact resistance can be formed, and good storage stability can be obtained.

  In the paste composition of one embodiment of the present invention, the black inorganic oxide preferably contains a composite oxide of Mn, Fe, and Sr. With such a configuration, the storage stability can be further improved.

In the paste composition of one embodiment of the present invention, the black inorganic oxide is a Mn—Fe oxide in which the molar ratio of Mn to Fe is Mn _x Fe _1-x (0 <x ≦ 0.8). Preferably there is. By setting the molar ratio of Mn to Fe in the Mn—Fe composite oxide within this range, better storage stability can be obtained.

In the paste composition of one embodiment of the present invention, the black inorganic oxide has a molar ratio of Mn, Fe, and Sr of Mn _x Fe _y Sr _1-xy (0 <x ≦ 0.8, 0 < It is preferable that the Mn—Fe—Sr composite oxide satisfying y ≦ 0.6 and 0 <1-xy ≦ 0.6). Mn in Mn-Fe-Sr composite oxide, by a molar ratio of Fe and Sr in this range, further improving storage stability of, it is possible to achieve at least one of suppression of blackness deteriorated.

The fired product pattern of one embodiment of the present invention is formed over a substrate and includes a composite oxide of Mn and at least one of Fe and Sr. In particular, when the complex oxide is a Mn—Fe complex oxide, the molar ratio of Mn to Fe is Mn _x Fe _1-x (0 <x ≦ 0.8), Mn—Fe—Sr complex oxide, The molar ratio of Mn, Fe and Sr is Mn _x Fe _y Sr _1-xy (0 <x ≦ 0.8, 0 <y ≦ 0.6, 0 <1-xy ≦ 0.6) By doing so, a black layer with better blackness and a low contact resistance value can be constituted.

  Further, such a fired product pattern is preferably used for the PDP. In the PDP, by having the fired product pattern of one embodiment of the present invention, uneven light emission, image defects, and increase in power consumption can be suppressed.

  According to one embodiment of the present invention, a black composition with good blackness and a low contact resistance value can be formed, a paste composition with good storage stability, and blackness with good contact resistance value. It is possible to provide a fired product pattern capable of forming a low black layer.

FIG. 6 shows a pattern used for measurement of a contact resistance value according to one embodiment of the present invention.

Below, the paste composition of this embodiment is demonstrated in detail.
The paste composition of this embodiment contains Mn, a black inorganic oxide containing a composite oxide of at least one of Fe and Sr, and an organic binder.

  The black inorganic oxide of the present embodiment includes a complex oxide of Mn and at least one of Fe and Sr. By including such a complex oxide, the storage stability can be improved without deteriorating the blackness and the contact resistance value. Among these, it is more preferable to include a composite oxide of Mn, Fe, and Sr. By containing both Fe and Sr, the storage stability can be further improved.

When the Mn—Fe composite oxide does not contain Sr, the molar ratio of Mn to Fe is preferably Mn _x Fe _1-x (0 <x ≦ 0.8). When the molar ratio of Mn exceeds 0.8, the storage stability tends to deteriorate.

In the case of a composite oxide of Mn—Fe—Sr containing Sr, the molar ratio of Mn, Fe, and Sr is Mn _x Fe _y Sr _1-xy (0 <x ≦ 0.8, 0 < It is preferable that y ≦ 0.6 and 0 <(1-xy) ≦ 0.6). By including Sr, the storage stability can be further improved, but by making this molar ratio range, it is possible to achieve at least one of further improvement of storage stability and suppression of blackness deterioration. Become.

  The black inorganic oxide particles preferably have a primary particle size D50 (meaning a particle size having a cumulative frequency of 50% in the number distribution curve of the primary particle size) of 0.10 to 0.60 μm. . When the primary particle size D50 is smaller than 0.10 μm, the redness and yellowness of the particles become strong, and when the primary particle size D50 is larger than 0.60 μm, the blackness of the particles becomes low. More preferably, it is 0.16-0.60 micrometer, More preferably, it is 0.20-0.40 micrometer. And it is preferable that a maximum primary particle size is 2.0 micrometers or less. When the maximum primary particle size is larger than 2.0 μm, the blackness of the particles tends to decrease.

Such a black inorganic oxide can be prepared, for example, as follows.
First, in a reaction tank, a complexing agent is added to a mixed aqueous solution of metal salts (Mn salt, Fe salt, Sr salt) while maintaining a reaction temperature of 30 to 70 ° C. in an inert gas atmosphere while adding sufficient stirring. As an aqueous ammonia solution is added. And the aqueous solution of an alkali metal hydroxide is added so that pH may be maintained at 9-12, and a Mn- (Fe-Sr) composite hydroxide is produced | generated. The Mn— (Fe—Sr) composite hydroxide is solid-liquid separated, washed with water, dried, then heat-treated at a temperature of 600 to 800 ° C. in an air atmosphere or an oxygen atmosphere, and pulverized as necessary.
In this way, a black inorganic oxide can be obtained.

  The content of the black inorganic oxide in the paste composition is preferably 1 to 30% by mass. When it is less than 1% by mass, good blackness cannot be obtained when a black layer is formed, and when it exceeds 30% by mass, dispersibility is deteriorated. More preferably, it is 5-25 mass%.

  The organic binder of this embodiment is used for imparting adhesiveness of the coating film, photocuring property, and the like. Examples of the organic binder include a resin having a carboxyl group, specifically, a carboxyl group-containing photosensitive resin having an ethylenically unsaturated double bond and a carboxyl group-containing resin having no ethylenically unsaturated double bond. Can be used. Specifically, the following resins (any of oligomers and polymers) are preferably used.

(1) A carboxyl group-containing resin obtained by copolymerizing an unsaturated carboxylic acid and a compound having an unsaturated double bond.
(2) A carboxyl group-containing photosensitive resin obtained by adding an ethylenically unsaturated group as a pendant to a copolymer of an unsaturated carboxylic acid and a compound having an unsaturated double bond.
(3) An unsaturated carboxylic acid is reacted with a copolymer of an epoxy group, a compound having an unsaturated double bond, and a compound having an unsaturated double bond, and a polybasic acid anhydride is added to the resulting secondary hydroxyl group. A carboxyl group-containing photosensitive resin obtained by reaction.
(4) A carboxyl group-containing photosensitive resin obtained by reacting a copolymer of an acid anhydride having an unsaturated double bond and a compound having an unsaturated double bond with a compound having a hydroxyl group and an unsaturated double bond. .
(5) A carboxyl group-containing photosensitive resin obtained by reacting an epoxy compound with an unsaturated monocarboxylic acid and reacting the resulting secondary hydroxyl group with a polybasic acid anhydride.
(6) Reaction of an organic acid having one carboxyl group in one molecule and not having an ethylenically unsaturated bond with the epoxy group of a copolymer of a compound having an unsaturated double bond and glycidyl (meth) acrylate And a carboxyl group-containing resin obtained by reacting the resulting secondary hydroxyl group with a polybasic acid anhydride.
(7) A carboxyl group-containing resin obtained by reacting a hydroxyl group-containing polymer with a polybasic acid anhydride.
(8) A carboxyl group-containing photosensitive resin obtained by further reacting a carboxyl group-containing resin obtained by reacting a hydroxyl group-containing polymer with a polybasic acid anhydride and a compound having an epoxy group and an unsaturated double bond.
These carboxyl group-containing photosensitive resins and carboxyl group-containing resins can be used alone or in combination.
Here, (meth) acrylate is a term that collectively refers to acrylate, methacrylate, and mixtures thereof, and the same applies to other similar expressions.

  In these carboxyl group-containing photosensitive resins and carboxyl group-containing resins, the weight average molecular weight is preferably 1,000 to 100,000. When the molecular weight is lower than 1,000, the adhesion of the coating film during development is adversely affected. On the other hand, when the molecular weight is higher than 100,000, poor development tends to occur. More preferably, it is 5,000-70,000.

  And it is preferable that the acid value is 50-250 mgKOH / g. When the acid value is lower than 50 mg KOH / g, the solubility in an alkaline aqueous solution is insufficient, and development failure tends to occur. On the other hand, when the acid value is higher than 250 mg KOH / g, the adhesion of the coating film is deteriorated during development and the photocured part (exposed part). ) Will be dissolved.

  In the case of a carboxyl group-containing photosensitive resin, the double bond equivalent is preferably 350 to 2,000. If the double bond equivalent is less than 350, a residue is likely to remain during baking. On the other hand, if it is greater than 2,000, the work margin during development is narrow, and a high exposure amount is required during photocuring. More preferably, it is 400-1500.

  Such an organic binder is preferably blended at a rate of 10 to 80% by mass of the total amount of the paste composition. When the amount is less than 10% by mass, the distribution in the coating film to be formed tends to be non-uniform, and it becomes difficult to obtain sufficient photocurability and photocuring depth, so that patterning by selective exposure and development becomes difficult. On the other hand, when it exceeds 80 mass%, the pattern at the time of baking and line width shrinkage will arise.

  In the paste composition of this embodiment, a dispersant can be blended in order to disperse the black inorganic oxide in the slurry. Such a dispersant is preferably water-soluble in order to suppress separation of the solvent and the black inorganic oxide in the slurry during long-term storage of the slurry.

  Such a dispersant is preferably an amphoteric dispersant having an acid value of 30 mgKOH / g or more and an amine value of 20 mgKOH / g or more. When the acid value is less than 30 mgKOH / g or the amine value is less than 20 mgKOH / g, the dispersibility between the black inorganic oxide and the organic binder is lowered, so that developability is lowered and a residue is easily generated. In addition, the storage stability is lowered, and separation is likely to occur over time.

  Such a dispersant preferably has a 10 mass% aqueous solution pH of 6.0 to 10.0. When the pH is less than 6.0, the black inorganic oxide in the paste composition reacts with the dispersant, and the black inorganic oxide may be dissolved when stored for a long period of time. On the other hand, when the pH is higher than 10.0, the black inorganic oxide and the solvent are easily separated during long-term storage of the paste composition.

  Examples of the dispersant having such characteristics include Disperbyk-180, Disperbyk-187, Disperbyk-191 (all manufactured by Big Chemie) as commercial products.

  It is preferable that the compounding quantity of such a dispersing agent is 0.1-20 mass parts with respect to 100 mass parts of organic binders. When the amount is less than 0.1 parts by mass, sufficient dispersibility cannot be obtained. On the other hand, when the amount exceeds 20 parts by mass, the blackness is lowered. More preferably, it is 0.5-10 mass parts, More preferably, it is 1-6 mass parts.

  In the present embodiment, a photopolymerizable monomer can be blended in order to promote photocurability and improve developability of the composition. Specific examples of such photopolymerizable monomers include 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, polyethylene glycol diacrylate, polyurethane diacrylate, and trimethylolpropane. Triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, trimethylolpropane ethylene oxide modified triacrylate, trimethylolpropane propylene oxide modified triacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate and each methacrylate corresponding to the above acrylate Phthalic acid, adipic acid, ma Mono-, di-, tri- or higher polyesters of polybasic acids such as inacid, itaconic acid, succinic acid, trimellitic acid, terephthalic acid and the like and hydroxyalkyl (meth) acrylate may be mentioned. It is not limited to things.

  Among these, a polyfunctional monomer having two or more acryloyl groups or methacryloyl groups in one molecule is preferable. These photopolymerizable monomers can be used alone or in combination of two or more.

  The amount of such a photopolymerizable monomer is appropriately 20 to 100 parts by mass per 100 parts by mass of the organic binder. When the blending amount of the photopolymerizable monomer is less than 20 parts by mass, it is difficult to obtain sufficient photocurability of the paste composition. On the other hand, when the amount exceeds 100 parts by mass, photocuring of the surface portion is accelerated as compared with the deep portion of the coating film, so that uneven curing tends to occur.

  Moreover, in the paste composition of this embodiment, in order to accelerate | stimulate photocuring, a photoinitiator can be mix | blended. Examples of such photopolymerization initiators include benzoin and benzoin alkyl ethers such as benzoin, benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether; acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2- Acetophenones such as diethoxy-2-phenylacetophenone and 1,1-dichloroacetophenone; 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino Aminoacetophenones such as -1- (4-morpholinophenyl) -butanone-1; anthraquinones such as 2-methylanthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone, 1-chloroanthraquinone; 2 Thioxanthones such as 4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-diisopropylthioxanthone; ketals such as acetophenone dimethyl ketal and benzyldimethyl ketal; benzophenones such as benzophenone; or xanthones; (2,6-dimethoxybenzoyl) -2,4,4-pentylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, ethyl Phosphine oxides such as -2,4,6-trimethylbenzoylphenyl phosphinate; various peroxides. These photopolymerization initiators can be used alone or in combination of two or more.

  The blending amount of these photopolymerization initiators is suitably 1 to 30 parts by mass per 100 parts by mass of the organic binder. If it is less than 1 part by mass, it will be difficult to obtain sufficient photocurability of the paste composition. On the other hand, when it exceeds 30 parts by mass, it is difficult to obtain sufficient blackness. More preferably, it is 5-20 mass parts.

  Examples of such photopolymerization initiators include tertiary compounds such as N, N-dimethylaminobenzoic acid ethyl ester, N, N-dimethylaminobenzoic acid isoamyl ester, pentyl-4-dimethylaminobenzoate, triethylamine, and triethanolamine. One or a combination of two or more amine photosensitizers can be used. Furthermore, when a deeper photocuring depth is required, a titanocene photopolymerization initiator that initiates radical polymerization in the visible region, a leuco dye, or the like can be used in combination as a curing aid if necessary. Examples of titanocene photopolymerization initiators include Irgacure 784 (manufactured by Ciba Specialty Chemicals) as a commercial product.

Furthermore, in the paste composition of this embodiment, a glass powder can be mix | blended as needed for the adhesive improvement of the pattern after baking. As such a glass powder, those having a glass transition point (Tg) of 300 to 500 ° C. and a glass softening point (Ts) of 400 to 600 ° C. are preferable from the viewpoint of the base glass substrate.
From the viewpoint of resolution, it is preferable to use glass powder having an average particle size of 20 μm or less, more preferably 5 μm or less.

As such a glass powder, an amorphous frit mainly composed of lead oxide, bismuth oxide, zinc oxide or the like is preferably used.
The blending amount of such glass powder is suitably 1 to 25% by mass in the paste composition. If it is less than 1% by mass, sufficient adhesion cannot be obtained, and if it exceeds 25% by mass, it is difficult to obtain good blackness. More preferably, it is 5-20 mass%.

  In the paste composition of the present embodiment, in order to suppress deterioration of storage stability and application workability due to gelation and fluidity reduction, black inorganic oxides and metals that are components of glass powder and oxides thereof It is preferable to add a stabilizer, such as a complex or a salt-forming compound such as an organic acid or an inorganic acid. The amount of the stabilizer added is preferably 0.1 to 10 parts by mass per 100 parts by mass of the black inorganic oxide and glass powder. When the amount is less than 0.1 parts by mass, a sufficient addition effect cannot be obtained, and when the amount exceeds 10 parts by mass, sufficient patterning by selective exposure and development becomes difficult.

  In addition, in the paste composition of the present embodiment, an organic solvent can be appropriately blended as a diluent for making a paste or adjusting the viscosity according to various coating methods. Specifically, ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene and tetramethylbenzene; cellosolve, methyl cellosolve, carbitol, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, di Glycol ethers such as propylene glycol monomethyl ether, dipropylene glycol monoethyl ether, triethylene glycol monoethyl ether; ethyl acetate, butyl acetate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, butyl carbitol acetate, propylene glycol monomethyl ether acetate Acetic acid esters such as ethanol, propanol, ethylene glycol, propylene glycol , Alcohols such as terpineol; octane, aliphatic hydrocarbons such as decane; petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and petroleum solvents such as solvent naphtha. These diluents can be used alone or in combination of two or more.

  Further, if necessary, additives such as a defoaming / leveling agent such as silicone and acrylic, and a silane coupling agent for improving the adhesion of the coating film can be blended. Further, if necessary, fine particles such as known antioxidants and metal oxides, silicon oxides, boron oxides and the like as a binding component with the substrate at the time of firing can be added.

  After the paste composition configured in this way is prepared with a predetermined composition, it is adjusted to a viscosity suitable for the application method with a diluent, for example, on a base material such as a glass substrate that becomes a front substrate of a PDP. Applied. As a coating method, a dip coating method, a flow coating method, a roll coating method, a bar coater method, a screen printing method, a curtain coating method, or the like is used. Using such a coating method, a coating film having a desired film thickness is formed.

  The coating film thus formed is volatilized and dried in order to obtain touch dryness. For the volatile drying, for example, a hot-air circulating drying furnace, a far-infrared drying furnace, or the like is used. Using such a drying furnace, for example, the organic solvent is evaporated by drying at about 60 to 120 ° C. for about 5 to 40 minutes to form a dry coating film (tack-free coating film).

  The dry coating film thus formed on the substrate is selectively irradiated (exposed) with active energy rays to form a pattern. As the exposure method, contact type or non-contact type exposure using a photomask on which a predetermined negative pattern is formed, or direct drawing is used. As the exposure light source, a halogen lamp, a high-pressure mercury lamp, a laser beam, a metal halide lamp, a black lamp, an electrodeless lamp, or the like is used.

  Specifically, an exposure machine equipped with a metal halide lamp, an exposure machine equipped with a (super) high-pressure mercury lamp, an exposure machine equipped with a mercury short arc lamp, or, for example, directly draws an image with a laser using CAD data from a computer. A direct drawing apparatus such as a laser direct imaging apparatus or a direct drawing apparatus using an ultraviolet lamp such as a (super) high pressure mercury lamp can be used.

It is preferable to use an active energy ray having a wavelength of 350 to 410 nm. By setting the wavelength within this range, radicals can be efficiently generated from the photopolymerization initiator, and the photopolymerization reaction can be promoted. The exposure amount is preferably about 50 to 1000 mJ / cm ² .

  In this manner, the exposed portion (the portion irradiated with the active energy ray) is cured by selectively exposing the dry coating film.

  Subsequently, the coating film selectively cured in this way is developed. At this time, as a developing method, a dipping method, a shower method, a spray method, a brush method, or the like can be used.

  Further, as the developer, aqueous metal alkali solutions such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate and sodium silicate, and aqueous amine solutions such as monoethanolamine, diethanolamine and triethanolamine, particularly about 1.5 mass. A dilute alkaline aqueous solution having a concentration of not more than% is preferably used, but is not limited thereto. For example, when a carboxyl group-containing resin is contained in the paste composition, the carboxyl group may be saponified and the uncured part (unexposed part) may be removed. In addition, after developing in this way, it is preferable to perform water washing and acid neutralization in order to remove an unnecessary developer.

  Further, the coating film thus developed is baked. In the baking step, the coated film after development is subjected to heat treatment at about 400 to 600 ° C. in air or in a nitrogen atmosphere to form a desired pattern. In addition, it is preferable to set the temperature increase rate at this time to 20 ° C./min or less for sufficient baking of the organic component in the pace composition.

By firing in this way, a fired product pattern that becomes a black layer is formed on the substrate. At this time, the fired product pattern includes a composite oxide of Mn and at least one of Fe and Sr. In the composite oxide in such a fired product pattern, when the composite oxide is a Mn—Fe composite oxide, the molar ratio of Mn to Fe is Mn _x Fe _1-x (0 <x ≦ 0.8), Mn In the case of -Fe-Sr composite oxide, the molar ratio of Mn, Fe and Sr is Mn _x Fe _y Sr _1-xy (0 <x ≦ 0.8, 0 <y ≦ 0.6, 0 ≦ 1). -X-y ≦ 0.6). By setting it as this range, a black layer with more favorable blackness and a low contact resistance value can be comprised.

  Moreover, it is preferable that 10-100 mass% of black inorganic oxides containing such a complex oxide are contained in the fired product pattern. It is because it will become difficult to obtain a favorable contact resistance value and blackness as it is less than 10 mass%.

  Such a fired product pattern is used as, for example, a bus electrode formed on a front plate of a PDP, a black pattern, or the like.

  Hereinafter, although an Example and a comparative example are shown and this embodiment is described concretely, it cannot be overemphasized that this invention is not limited to the following Examples. “Parts” and “%” are based on mass unless otherwise specified.

(Preparation of black inorganic oxide)
Manganese sulfate, iron sulfate and strontium carbonate were dissolved in ion-exchanged water so as to have a predetermined molar ratio to prepare a 1.5 mol / L metal salt aqueous solution.

  While controlling the prepared aqueous metal salt solution in a nitrogen atmosphere so that the reaction vessel temperature is 50 ° C., the pH of the aqueous solution is dropped into an effective volume 15 L reaction vessel containing 10 L of ion exchange water together with the aqueous ammonium sulfate solution. An aqueous sodium hydroxide solution was added dropwise so as to maintain 10.8. In this way, a spherical composite hydroxide was obtained.

  The spherical composite hydroxide was heat-treated at a firing temperature of 650 ° C. for 5 hours and pulverized to obtain black inorganic oxides having the compositions and molar ratios shown in Table 1.

  Here, a part of the obtained black inorganic oxide was dissolved in hydrochloric acid, and the content of each metal was measured using ICP emission analysis.

(Preparation of black inorganic oxide slurry)
15 kg of the black inorganic oxide thus obtained was mixed with a mixed solution of 5.09 kg of tripropylene glycol monomethyl ether as a diluent and 0.21 kg of BYK (registered trademark) 180 (manufactured by Big Chemie) as a dispersant. did. And it stirred for 1 hour using the bead mill so that the powder lump which the black inorganic oxide powder aggregated did not remain in a mixed solution, and the preliminary | backup slurry was obtained.

  The pre-slurry thus obtained was introduced into a bead mill (LMZ4 type manufactured by Ashizawa Finetech Co., Ltd.) filled with zirconia beads having a diameter of 0.1 mm in a volume conversion by a volume, and the rotation of the rotor. Circulation and wet pulverization were performed at a peripheral speed of 12 m / s to obtain a black inorganic oxide slurry containing a black inorganic oxide having the composition and molar ratio shown in Table 1. At this time, when the average particle size of the black inorganic oxide in the slurry reached 0.26 to 0.31 μm in the particle size measurement by the laser diffraction method, the end point was set.

(Synthesis of organic binder)
A flask equipped with a thermometer, stirrer, dropping funnel, and reflux condenser is charged with methyl methacrylate and methacrylic acid in a molar ratio of 0.87: 0.13, diethylene glycol monomethyl ether acetate as a solvent, and azobisisobutyrate as a catalyst. Ronitrile was added, and the mixture was stirred at 80 ° C. for 2 to 6 hours under a nitrogen atmosphere to obtain an organic binder.

  The obtained organic binder had a weight average molecular weight of about 30,000, an acid value of 90 mgKOH / g, and a solid content of 50%. The weight average molecular weight was measured by high performance liquid chromatography in which three Shimadzu pumps LC-6AD and Showa Denko columns Shodex (registered trademark) KF-804, KF-803, and KF-802 were connected.

(Preparation of glass slurry)
As glass powder, Bi ₂ O ₃ 50%, B ₂ O ₃ 16%, ZnO 14%, SiO ₂ 2%, BaO 18%, thermal expansion coefficient α ₃₀₀ = 86 × 10 ⁻⁷ / ° C., glass softening point 501 ° C. I used one.

Such glass powder was pulverized using a bead mill. At this time, beads made of ZrO ₂ with a media diameter of 0.3 to 0.8 mmφ were used, and the grinding conditions were 2,000 to 3,300 rpm and 3 to 9 hours.

After roughly pulverizing the glass powder, filtering was performed with a 300-mesh screen. And, 70 parts by mass of this glass powder, 29,16 parts by mass of 2,2,4-trimethyl-1,3-pentanediol monobutyrate as a diluent, and BYK-410 (by Big Chemie) as a dispersant 0.14 parts by mass and 0.7 parts by mass of BYK-182 (manufactured by Big Chemie) were added and finely pulverized with a bead mill. In this way, a slurry having a glass powder content of 70% by mass was obtained. Incidentally, by using a Horiba laser diffraction / scattering particle size distribution analyzer LA-920, was measured particle size distribution of the glass _{powder, D 50: 1.0μm, D max} : was 3.9 .mu.m.
Furthermore, the produced glass slurry was filtered with a mesh made of SUS 200 × 1400 twill. At this time, no change was observed in the particle size distribution.

(Preparation of paste)
The black inorganic oxide slurry containing the black inorganic oxide having the composition and molar ratio shown in Table 1 thus obtained, the organic binder, the glass slurry, and other additives in a plastic container at the following blending ratios, respectively. The mixture was mixed and stirred for 10 minutes at 500 rpm using a dissolver. Then, the obtained mixture was kneaded twice with a ceramic three roll to obtain each paste.
Black inorganic oxide slurry: 67.0 parts Organic binder: 100.0 parts Glass slurry: 43.0 parts Diluent: Diethylene glycol monomethyl ether acetate: 110.0 parts Trimethylolpropane EO-modified triacrylate: 30.0 parts Diventa Erythritol hexaacrylate: 15.0 parts Polyester acrylate (trade name M-7100, manufactured by Toagosei Co., Ltd.): 50.0 parts 2,4-diethylthioxanthone: 3.0 parts 4,4-bis (diethylamino) benzophenone: 1. 0 parts Leveling agent (Modaflow (registered trademark), manufactured by Monsanto): 3.0 parts Phosphate ester: 1.0 part 2-Methyl-1- (4-methylthiophenyl) -2-morpholinopropane-1- On: 10.0 parts γ-methacryloxypropyltrimethoxysilane: 3.0 parts

Each paste composition obtained was evaluated as follows.
(Evaluation of blackness)
<Preparation of blackness measurement specimen>
First, each paste was applied on the entire surface of a glass substrate using a 300 mesh polyester screen. Subsequently, it dried for 20 minutes at 90 degreeC using the hot-air circulation type drying furnace, and formed the dry coating film about 4 micrometers thick.

The obtained dried coating film was subjected to pattern exposure at an exposure amount (integrated light amount on the dried coating film) of 600 mJ / cm ² using an ultra-high pressure mercury lamp as a light source, and then a 0.4 wt% sodium carbonate aqueous solution having a liquid temperature of 25 ° C. It was used for development and washed with water.
The solid film with the pattern thus obtained was baked at a heating rate of 14 ° C./min and a baking temperature of 590 ° C. for 10 minutes.

Next, a dielectric (YPT-065F (AP5655AE), manufactured by Asahi Glass Co., Ltd.) was applied over the entire surface of the fired film using a 100 mesh polyester screen.
Furthermore, after drying at 90 ° C. for 20 minutes using a hot-air circulating drying furnace, the test piece was obtained by firing at a heating rate of 14 ° C./min and a firing temperature of 590 ° C. for 10 minutes.

<Measurement of blackness>
About the test piece produced in this way, L value was measured using the spectrocolorimeter (Minolta Camera Co., Ltd. CM2600d), and L value which is an index representing brightness was evaluated as an index of blackness. The evaluation criteria are as follows.
○: L value is 30 or less ×: L value exceeds 30

(Evaluation of contact resistance value)
<Preparation of Ag paste>
An Ag paste used for preparing a contact resistance measurement substrate was prepared as follows.

  First, in a flask equipped with a thermometer, a stirrer, a dropping funnel, and a reflux condenser, diethylene glycol monoethyl ether acetate as a solvent and azobisisobutyronitrile as a catalyst are placed and heated to 80 ° C. in a nitrogen atmosphere. A monomer mixed at a molar ratio of methacrylic acid: 0.4 mol and methyl methacrylate: 0.6 mol was added dropwise over about 2 hours.

  After further stirring for 1 hour, the temperature was raised to 115 ° C. to inactivate to obtain a resin solution. After cooling this resin solution, tetrabutylammonium bromide was used as a catalyst, and 95 mol to 115 ° C. for 30 hours. Reacted and cooled. Further, 0.26 mol of tetrahydrophthalic anhydride was added to the OH group of the obtained resin solution under the conditions of 95 to 105 ° C. and 8 hours, cooled and taken out to obtain an organic binder having a solid content of 55%. Obtained.

The obtained organic binder, silver powder having an average particle size (D50) of 2.2 μm, a maximum particle size (Dmax) of 6.3 μm, a surface area of 0.3 m ² / g, and other additives are mixed in a plastic container at the following blending ratio. And stirred for 10 minutes at 500 rpm using a dissolver. Then, the obtained mixture was kneaded twice with a ceramic three roll to obtain an Ag paste.
Organic binder: 100.0 parts Silver powder: 450.0 parts Diethylene glycol monoethyl ether acetate: 90.0 parts Trimethylolpropane triacrylate: 25.0 parts Trimethylolpropane EO-modified triacrylate: 25.0 parts 2-Benzyl-2 -Dimethylamino-1- (4-morpholinophenyl) butan-1-one: 10.0 parts Glass slurry: 22.0 parts Phosphate ester: 1.0 part Antifoam agent (BYK-354: Big Chemie Japan) Manufactured): 1.0 part

<Preparation of substrate for contact resistance measurement>
Each paste was applied to the entire surface of a glass substrate (PD200 manufactured by Asahi Glass Co., Ltd.) on which an ITO film was previously formed using a 200 mesh polyester screen. Subsequently, it dried for 20 minutes at 90 degreeC using the hot-air circulation type drying furnace, and formed the dry coating film of about 5 micrometers.

Next, using an ultra-high pressure mercury lamp as a light source and exposing so that the integrated light quantity on the dried coating film becomes 600 mJ / cm ² , the prepared Ag paste is used on the exposed coating film using a 200 mesh polyester screen. Applied to the entire surface.
The obtained Ag paste coating film was dried at 90 ° C. for 20 minutes in a hot air circulation type drying furnace to form a dry coating film of about 10 μm.

The obtained dried coating film was subjected to pattern exposure at an exposure amount (cumulative light amount on the dried coating film) of 400 mJ / cm ² using an ultra-high pressure mercury lamp as a light source, and then a 0.4 wt% sodium carbonate aqueous solution having a liquid temperature of 25 ° C. It was used for development and washed with water.
The solid film with the pattern thus obtained was baked at a heating rate of 14 ° C./min and a baking temperature of 590 ° C. for 10 minutes to obtain a test piece having the pattern shown in FIG.

<Measurement of contact resistance value>
In the firing pattern shown in FIG. 1, measurement of the contact resistance value ((1) to (5)) in the pattern formed from each paste composition is performed using a HIOKI (registered trademark) 3540 mΩ hitester manufactured by HIOKI, The average value of each was obtained.

(Evaluation of storage stability)
In each paste composition, the initial viscosity was measured and stored at 40 ° C. for 7 days, and then the viscosity after storage was measured in the same manner as the initial viscosity.
From the measured initial viscosity and viscosity after storage, the rate of increase in viscosity was determined by the following formula.
(Viscosity after storage-initial viscosity) x 100 / initial viscosity (%)

The storage stability was evaluated from the viscosity increase rate thus determined. The evaluation criteria are as follows.
○: Viscosity increase rate is less than 30% ×: Viscosity increase rate is more than 30% Gelation: Paste composition is changed from liquid to semi-solid after storage

Table 1 shows the evaluation results of blackness, contact resistance value, and storage stability.

As shown in Table 1, in Comparative Examples 1 and 2 using Mn oxide or Mn—Fe—Cu composite oxide using Cu instead of Sr, the storage stability is clearly deteriorated. In Comparative Example 2 and Comparative Example 3 using Co oxide, the contact resistance value is high. On the other hand, in Examples 1 to 3 , it can be seen that in the fired product, good blackness and low contact resistance can be obtained, and good storage stability in the paste can be obtained.

Claims (3)

It contains a resin having a black inorganic oxide, and a carboxyl group containing a composite oxide of M n, Fe and Sr,
The molar ratio of Mn, Fe and Sr of the composite oxide is Mn _x Fe _y Sr _1-xy (0 <x ≦ 0.8, 0 <y ≦ 0.6, 0 <1-xy ≦). 0.6). A paste composition characterized in that it is 0.6). Is formed on a substrate, a sintered product pattern comprising a composite oxide of M n, Fe and Sr,
The molar ratio of Mn, Fe and Sr of the composite oxide is Mn _x Fe _y Sr _1-xy (0 <x ≦ 0.8, 0 <y ≦ 0.6, 0 <1-xy ≦). 0.6) , a fired product pattern.   A plasma display panel comprising the fired product pattern according to claim 2.

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