JP4954647B2 - Plasma display panel having photosensitive paste and fired product pattern formed from the photosensitive paste - Google Patents

Description

  The present invention relates to a photosensitive paste useful for forming a partition pattern, a dielectric pattern, an electrode pattern, and a black matrix pattern of a plasma display panel (hereinafter abbreviated as PDP). More specifically, it can be suitably used to form the fired product pattern for PDP having stable printability, and has excellent adhesion to the substrate, resolution, and drying, exposure, development, and firing processes. The present invention relates to a photosensitive paste that can form a fired film without impairing the fireability.

  The PDP is a flat display that displays images and information using light emission by plasma discharge, and is classified into a DC type and an AC type depending on a panel structure and a driving method. The principle of color display by PDP is that plasma discharge is generated in the cell space (discharge space) between the opposing electrodes formed on the front glass substrate and the rear glass substrate separated by ribs (partition walls), and each cell space. The phosphor formed on the inner surface of the rear glass substrate is excited by ultraviolet rays generated by the discharge of a gas such as He or Xe enclosed therein, and three primary colors of visible light are generated. Each cell space is defined by grid-like ribs in the DC type PDP, and is defined by ribs arranged in parallel to the substrate surface in the AC type PDP. Made by ribs. Hereinafter, it will be briefly described with reference to the accompanying drawings.

  FIG. 1 partially shows an example of the structure of a surface discharge AC type PDP having a three-electrode structure for full color display. On the lower surface of the front glass substrate 1, a large number of a pair of display electrodes 2a and 2b, each consisting of transparent electrodes 3a and 3b for discharging and bus electrodes 4a and 4b for reducing the line resistance of the transparent electrodes, are formed at a predetermined pitch. It is lined up. On these display electrodes 2a and 2b, a transparent dielectric layer 5 (low melting point glass) for accumulating charges is formed by printing and baking, and a protective layer (MgO) 6 is deposited thereon. . The protective layer 6 has a role of protecting the display electrode, maintaining a discharge state, and the like. On the other hand, on the rear glass substrate 11, striped ribs (partitions) 12 partitioning the discharge space and a plurality of address electrodes (data electrodes) 13 arranged in each discharge space are arranged in a predetermined pitch. Yes. In addition, on the inner surface of each discharge space, phosphor films of three colors of red (14a), blue (14b), and green (14c) are regularly arranged, and in full color display, as described above, red, blue The three primary color phosphor films 14a, 14b, and 14c constitute one pixel.

  Further, striped black patterns 10 and 10 are similarly formed on both sides of the pair of display electrodes 2a and 2b forming the discharge space in order to further increase the contrast of the image.

  In the PDP having the above structure, an alternating pulse voltage is applied between the pair of display electrodes 2a and 2b to cause discharge between the electrodes on the same substrate.

  In the PDP having the above structure, ultraviolet light generated by discharge excites the phosphor films 14a, 14b, and 14c of the back substrate 11, and the generated visible light is viewed through the transparent electrodes 3a and 3b of the front substrate 1. It has become.

  In the PDP having such a structure, the bus electrodes 4a and 4b and the address electrodes 2a and 2b are conventionally formed by depositing three layers of Cr—Cu—Cr by vapor deposition or sputtering, and then patterning by photolithography. Has been done.

  However, since the number of steps is high and the cost is high, recently, a method of baking after conductive printing such as silver paste is performed, or in order to obtain a line width of 150 μm or less, photosensitive conductive paste is used. A method of applying, exposing through a pattern mask, developing, and baking is performed.

  In recent years, PDP substrates on which electrodes are formed in this way have been subjected to multi-sided production of several substrates from a single large substrate in order to increase the screen size and cost. However, when the paste is applied to the substrate by screen printing, there is a problem that pinholes and printing unevenness are likely to occur.

  Accordingly, the present invention has been made to solve such problems of the conventional technology, and its main purpose is to provide a high-definition electrode pattern for a plasma display panel that can be printed without pinholes or uneven printing. Is a photosensitive paste that can form a fired film without impairing excellent adhesion, resolution, and fireability to the substrate in each step of drying, exposure, development, and firing. Is to provide a sex paste.

  Another object of the present invention is to provide a plasma display panel in which a high-definition fired product pattern is formed from such a photosensitive paste.

In order to achieve the above object, according to a first aspect of the present invention, (A) an organic binder, (B) a photopolymerizable monomer, (C) a photopolymerization initiator, (D) inorganic fine particles, (E) A photosensitive paste containing an organic solvent and (F) additive, the organic solvent (E) contains a high boiling point organic solvent having a boiling point of 210 ° C. or higher, and acrylic leveling as the additive (F) amine and phosphorus-based content of one or a plasma display panel photosensitive paste containing two or more dispersants selected from powders are provided with agent.

  In one form of the present invention, diethylene glycol monomethyl ether acetate is contained in the organic solvent (E) as a high boiling point organic solvent having a boiling point of 210 ° C. or higher, and the content thereof is 5% by mass or more based on the total amount of the photosensitive paste.

  Furthermore, according to another aspect of the present invention, there is provided a plasma display panel comprising an electrode formed from a fired product of the photosensitive paste.

  By forming a coating film with few pinholes using the photosensitive paste of the present invention, it is possible to stably produce a panel free from electrode defects and shape defects, which is extremely useful for mass production and cost reduction of PDPs. It is.

  As a result of intensive research aimed at realizing the above object, the present inventors have found that (A) an organic binder, (B) a photopolymerizable monomer, (C) a photopolymerization initiator, (D) inorganic fine particles, and (E) an organic solvent. And (F) a photosensitive paste containing an additive, the organic solvent (E) contains a high-boiling organic solvent having a boiling point of 210 ° C. or higher, and an acrylic leveling agent as the additive (F) A photosensitive paste containing one or more dispersants selected from amine-based, phosphorus-based and carboxylic acid-based dispersants has a uniform coating film after glass substrate printing and has few pinholes. As a result, it has been found that a panel free from electrode defects and shape defects can be stably produced, and the present invention has been completed.

  Examples of the organic binder (A) used in the photosensitive paste of the present invention include a carboxyl group-containing resin, specifically, a carboxyl group-containing photosensitive resin having an ethylenically unsaturated double bond and an ethylenically unsaturated group. Any carboxyl group-containing resin having no double bond can be used. Specific examples include the following.

(1) a carboxyl group-containing resin obtained by copolymerizing an unsaturated carboxylic acid such as (meth) acrylic acid and a compound having an unsaturated double bond such as methyl (meth) acrylate,
(2) A copolymer of an unsaturated carboxylic acid such as (meth) acrylic acid and a compound having an unsaturated double bond such as methyl (meth) acrylate, glycidyl (meth) acrylate, (meth) acrylic acid chloride, etc. A carboxyl group-containing photosensitive resin obtained by adding an ethylenically unsaturated group as a pendant,
(3) A copolymer of an epoxy group such as glycidyl (meth) acrylate and an unsaturated double bond and a compound having an unsaturated double bond such as methyl (meth) acrylate, (meth) acrylic acid, etc. A carboxyl group-containing photosensitive resin obtained by reacting an unsaturated carboxylic acid of the product, and reacting a polybasic acid anhydride such as tetrahydrophthalic acid anhydride with the generated secondary hydroxyl group,
(4) To a copolymer of an acid anhydride having an unsaturated double bond such as maleic anhydride and a compound having an unsaturated double bond such as styrene, a hydroxyl group such as 2-hydroxyethyl (meth) acrylate and A carboxyl group-containing photosensitive resin obtained by reacting a compound having a saturated double bond;
(5) A carboxyl obtained by reacting a polyfunctional epoxy compound with an unsaturated monocarboxylic acid such as (meth) acrylic acid, and reacting the resulting secondary hydroxyl group with a polybasic acid anhydride such as tetrahydrophthalic anhydride. Group-containing photosensitive resin,
(6) An epoxy group of a copolymer of an unsaturated double bond such as methyl (meth) acrylate and a glycidyl (meth) acrylate has one carboxyl group in one molecule, and an ethylenically unsaturated bond A carboxyl group-containing resin obtained by reacting an organic acid not having a hydrogen atom, and reacting a polybasic acid anhydride with the generated secondary hydroxyl group,
(7) a carboxyl group-containing resin obtained by reacting a polybasic acid anhydride with a hydroxyl group-containing polymer such as polyvinyl alcohol, and (8) a hydroxyl group-containing polymer such as polyvinyl alcohol with a polytetrahydrophthalic anhydride Examples include carboxyl group-containing photosensitive resins obtained by further reacting a carboxyl group-containing resin obtained by reacting a basic acid anhydride with a compound having an unsaturated double bond with an epoxy group such as glycidyl (meth) acrylate. In particular, the resins (1), (2), (3), and (6) are preferably used.

  In addition, in this specification, (meth) acrylate is a term that collectively refers to acrylate, methacrylate, and mixtures thereof, and the same applies to other similar expressions.

  These carboxyl group-containing resins and carboxyl group-containing photosensitive resins may be used alone or in combination, but in any case, they should be blended in a proportion of 10 to 80% by mass of the total mass of the composition. Is preferred. When the blending amount of these polymers is less than the above range, the distribution of the resin in the film to be formed tends to be non-uniform, and it is difficult to obtain sufficient photocurability and photocuring depth, and selective exposure and development. Makes patterning difficult. On the other hand, if it is more than the above range, it is not preferable because the pattern during baking and the shrinkage of the line width are likely to occur.

  The carboxyl group-containing resin and the carboxyl group-containing photosensitive resin each have a weight average molecular weight of 1,000 to 100,000, more preferably 5,000 to 70,000, and an acid value of 50 to 250 mgKOH / g, and In the case of a carboxyl group-containing photosensitive resin, those having a double bond equivalent of 350 to 2,000, more preferably 400 to 1,500 can be suitably used. When the molecular weight of the resin is lower than 1,000, the adhesion of the film during development is adversely affected. On the other hand, when the molecular weight is higher than 100,000, development defects are liable to occur. On the other hand, when the acid value is lower than 50 mgKOH / 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 mgKOH / g, the adhesion of the film is deteriorated during development and the photocured part (exposure) Part) is not preferable. Further, in the case of a carboxyl group-containing photosensitive resin, if the double bond equivalent of the photosensitive resin is less than 350, a residue is likely to remain at the time of baking, whereas if it is greater than 2,000, a work margin at the time of development. Is narrow, and a high exposure amount is required at the time of photocuring.

  The photopolymerizable monomer (B) used in the photosensitive paste of the present invention is used for promoting photocurability and improving developability of the composition. For example, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, polyethylene glycol diacrylate, polyurethane diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, tri Methylolpropane 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, maleic acid, itaconic acid, Succinic acid, trimellitic acid, Examples include mono-, di-, tri- or higher polyesters of polybasic acids such as phthalic acid and hydroxyalkyl (meth) acrylates, but are not limited to specific ones. Or two or more types can be used in combination. Among these photopolymerizable monomers, polyfunctional monomers having two or more acryloyl groups or methacryloyl groups in one molecule are preferable.

  The blending ratio of such a photopolymerizable monomer (B) is suitably 20 to 100 parts by mass per 100 parts by mass of the organic binder (carboxyl group-containing photosensitive resin and / or carboxyl group-containing resin) (A). . When the amount of the photopolymerizable monomer (B) is less than the above range, it is difficult to obtain sufficient photocurability of the composition. On the other hand, when the amount exceeds the above range, the surface is larger than the deep part of the film. Since the photo-curing of the part is accelerated, uneven curing is likely to occur.

  Specific examples of the photopolymerization initiator (C) used in the photosensitive paste of the present invention include benzoin and benzoin alkyl ethers such as benzoin, benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether; acetophenone, 2, Acetophenones such as 2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone; 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopro Pan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, 2- (dimethylamino) -2-[(4-methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone and the like Minoacetophenones; anthraquinones such as 2-methylanthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone, 1-chloroanthraquinone; 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2 Thioxanthones such as 1,4-diisopropylthioxanthone; ketals such as acetophenone dimethyl ketal and benzyl dimethyl 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-2,4,6-tri Phosphine oxide such as chill benzoylphenyl phosphinate Nate; various peroxides and the like can be used alone or in combination of two or more of these conventionally known photopolymerization initiator.

  The mixing ratio of these photopolymerization initiators (C) is suitably 1 to 30 parts by mass per 100 parts by mass of the organic binder (carboxyl group-containing photosensitive resin and / or carboxyl group-containing resin) (A), Preferably, it is 5-20 mass parts.

  The photopolymerization initiator (C) is composed of N, N-dimethylaminobenzoic acid ethyl ester, N, N-dimethylaminobenzoic acid isoamyl ester, pentyl-4-dimethylaminobenzoate, triethylamine, triethanolamine. It can be used in combination with one or more photosensitizers such as tertiary amines.

  Furthermore, when a deeper photocuring depth is required, a titanocene photopolymerization initiator such as Irgacure 784 manufactured by Ciba Specialty Chemicals, which starts radical polymerization in the visible region, and leuco dyes are cured as necessary. It can be used in combination as an auxiliary agent.

  Furthermore, when a deeper photocuring depth is required, a thermal polymerization catalyst can be used in combination with the photopolymerization initiator (C) as necessary. This thermal polymerization catalyst is capable of reacting an uncured photopolymerizable monomer by aging at a high temperature for several minutes to about 1 hour. Specifically, a peroxide such as benzoyl peroxide, azoisobutyronitrile, etc. Azo compounds such as 2,2′-azobisisobutyronitrile, 2,2′-azobis-2-methylbutyronitrile, 2,2′-azobis-2,4-gibarero Nitrile, 1'-azobis-1-cyclohexanecarbonitrile, dimethyl-2,2'-azobisisobutyrate, 4,4'-azobis-4-cyanovaleric acid, 2-methyl-2,2'-azo Bispropanenitrile, 2,4-dimethyl-2,2,2 ′, 2′-azobispentanenitrile, 1,1′-azobis (1-acetoxy-1-phenylethane), 2, , 2 ′, 2′-azobis (2-methylbutanamide oxime) dihydrochloride and the like, and more preferable are environmentally friendly non-cyanide and non-halogen type 1,1′-azobis (1-acetoxy-1-phenyl) Ethane).

The photosensitive paste of the present invention contains inorganic fine particles (D), and the inorganic fine particles (D) contain glass fine particles, pigments, conductive metal powders or metal oxides, and one or more of inorganic fillers. It is preferable to do.
The content of the inorganic component varies depending on the desired fired product pattern. First, in the case of forming a partition pattern and a dielectric pattern, glass fine particles are used, and in the case of a black matrix pattern, glass fine particles and a black pigment are used. On the other hand, in the case of electrode pattern formation, conductive powder (conductive metal powder and / or metal oxide) is used, but an appropriate amount of glass fine particles may be used in combination in order to improve firing properties as will be described later. Further, when forming a black electrode pattern, a black pigment is also used. In addition, an aggregate (inorganic filler) can be added to the photosensitive paste composition as desired.

  As the glass fine particles, those having a glass transition point (Tg) of 300 to 500 ° C. and a glass softening point (Ts) of 400 to 600 ° C., for example, those mainly composed of lead oxide, bismuth oxide, or zinc oxide are preferably used. it can. From the viewpoint of resolution, glass fine particles having an average particle diameter of 10 μm or less, preferably 3 μm or less are suitably used.

  The black pigment in the inorganic fine particles (D) is used when black is required for the fired product pattern, and is composed of one or more metal oxides such as Fe, Co, Ni, Cu, Mn, and Al. Can be added.

As the conductive metal powder or metal oxide in the inorganic fine particles (D), any conductive powder having a specific resistance value of 1 × 10 ³ Ω · cm or less can be used widely. Silver (Ag), gold (Au ), Nickel (Ni), copper (Cu), aluminum (Al), tin (Sn), lead (Pb), zinc (Zn), iron (Fe), platinum (Pt), iridium (Ir), osmium (Os) ), Palladium (Pd), rhodium (Rh), ruthenium (Ru), tungsten (W), molybdenum (Mo), etc. and their alloys, as well as tin oxide (SnO ₂ ), indium oxide (In ₂ O ₃ ) Indium Tin Oxide (ITO), ruthenium oxide (RuO ₂ ), or the like can be used. These can be used alone or as a mixed powder of two or more.

  Various shapes such as a spherical shape, a flake shape, and a resin shape can be used for the conductive metal powder or the metal oxide, but it is preferable to use a spherical shape in consideration of optical characteristics and dispersibility. The average particle diameter is suitably 10 μm or less, preferably 5 μm or less from the viewpoint of resolution. In order to prevent the conductive metal powder from being oxidized, to improve the dispersibility in the composition, and to stabilize the developability, it is particularly preferable to treat Ag, Ni, and Al with a fatty acid. Examples of the fatty acid include oleic acid, linoleic acid, linolenic acid, stearic acid, and the like.

  The mixing ratio of the conductive metal powder or metal oxide is appropriately 50 to 80% by mass with respect to the total amount of the photosensitive paste. When the blending amount of the conductive powder is less than the above range, sufficient conductivity of the conductor pattern obtained from such a paste cannot be obtained. On the other hand, when the amount exceeds the above range, the adhesion to the substrate is poor. Since it gets worse, it is not preferable.

  As the inorganic filler in the inorganic fine particles (D), any material that can contribute to improving the denseness inside the fired product pattern such as partition walls, such as alumina, silica, zircon, and titanium oxide, can be used. That is, the glass component shrinks during firing, but the shrinkage rate and internal denseness can be adjusted by the blending amount of the inorganic filler.

  As the organic solvent (E) used in the photosensitive paste of the present invention, it is particularly preferable to use a high boiling organic solvent having a boiling point of 210 ° C. or higher, and glycol esters (for example, diethylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether). Acetate, butyl carbitol acetate, 2,2,4-trimethyl-1,3-pentanediol diisobutyrate, etc.); glycol ethers (for example, ethylene glycol 2-ethylhexyl ether, ethylene glycol phenyl ether, diethylene glycol monobutyl ether, diethylene glycol) n-hexyl ether, diethylene glycol 2-ethylhexyl ether, triethylene glycol monomethyl ether, triethylene glycol monotri Tylene glycol monoethyl ether, triethylene glycol monobutyl ether, dipropylene glycol monobutyl ether, dipropylene glycol n-butyl ether, tripropylene glycol monomethyl ether, tripropylene glycol tripropylene glycol n-butyl ether, etc.); alcohols (for example, diethylene glycol, Triethylene glycol, 1,4-butanediol, octanediol, butyl carbitol and the like); hydrocarbons (for example, trade names Solvesso # 150, Solvesso # 200) and the like. These may be used alone or in combination of two or more. It can be used by mixing. Of these, diethylene glycol monomethyl ether acetate is preferred. The upper limit of the boiling point is not particularly limited, but is suitably 300 ° C. or less from the viewpoint of drying and the like.

  A suitable blending ratio of such an organic solvent (E) is preferably 5% by mass or more, more preferably 5% by mass or more and 30% by mass or less, based on the total amount of the paste. If it is less than 5% by mass, a plate separation failure occurs during printing, which is not preferable. Moreover, when it contains exceeding 30 mass%, since the viscosity of a paste falls and the coating film after printing becomes difficult to dry, it is unpreferable.

  Furthermore, as a solvent other than the high boiling organic solvent having a boiling point of 210 ° C. or higher, such as diethylene glycol monomethyl ether acetate, an appropriate amount of an organic solvent can be blended. Specifically, ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene and tetramethylbenzene; cellosolve, methylcellosolve, carbitol, methylcarbitol, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether Glycol ethers such as ethyl acetate, butyl acetate, cellosolve acetate, butyl cellosolve acetate, propylene glycol monomethyl ether acetate, 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate, and esters such as γ-butyrolactone Alcohols such as ethanol, propanol, ethylene glycol, propylene glycol, and terpineol; aliphatic hydrocarbons such as octane and decane Petroleum solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha, 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate, and the like can be mentioned. Can be used in combination.

  In the photosensitive paste of the present invention, when a large amount of inorganic powder is blended in the photocurable resin composition, the storage stability of the resulting composition is poor, and the coating workability is deteriorated due to gelation and fluidity reduction. Tend. Therefore, in the composition of the present invention, in order to improve the storage stability of the composition, a compound having an effect of complexing or forming a salt with a metal or oxide powder which is a component of the inorganic powder is added as a stabilizer. be able to. As stabilizer, boric acid as inorganic acid, organic acid; formic acid, acetic acid, malic acid, malonic acid, acetoacetic acid, citric acid, stearic acid, maleic acid, fumaric acid, phthalic acid, benzenesulfonic acid, sulfamic acid Other than phosphoric acid, phosphorous acid, hypophosphorous acid, methyl phosphate, ethyl phosphate, butyl phosphate, phenyl phosphate, ethyl phosphite, diphenyl phosphite, mono (2-methacryloyloxyethyl) acid Acids, such as various phosphoric acid compounds (inorganic phosphoric acid, organic phosphoric acid), such as a phosphate, are mentioned, It can use individually or in combination of 2 or more types.

  The photosensitive paste of the present invention contains one or more dispersants selected from amine-based, phosphorus-based and carboxylic acid-based dispersants together with an acrylic leveling agent as an additive (F).

  As acrylic leveling agents (antifoaming agents), specifically, acrylates such as methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate cyclohexyl acrylate and the like Can be used alone or as a copolymer obtained by copolymerizing two or more of them. Examples of commercially available products include Modaflow (manufactured by Surface Specialties), Polyflow No. 75, no. 77, no. 85, no. 90, no. 95, Polyflow S (all manufactured by Kyoeisha Chemical Co., Ltd.), BYK-354, -350, -352, -355, -356 (all manufactured by BYK Chemie) can be used. Acrylic leveling agents have moderate compatibility with acrylic organic binders, thus preventing problems such as repellency due to poor compatibility, as seen when using silicones as leveling agents. it can.

  As a commercially available product as a dispersant, for example, Disperbyk (registered trademark) -112, -161, -182, -191 (all manufactured by BYK Chemie) as an amine dispersant; Light ester P-1M (manufactured by Osaka Organic Chemical Industry Co., Ltd.), JPA-514 (manufactured by Johoku Chemical Industry Co., Ltd.), Disperbyk-110, -111, -142, -180 (all manufactured by BYK Chemie), DA- 325 (manufactured by Enomoto Kasei Co., Ltd.); BYK-P105 (manufactured by BYK Chemie), Florene G-700 (manufactured by Kyoeisha Chemical Co., Ltd.) and the like can be used as the carboxylic acid dispersant.

  In this invention, the suitable mixture ratio of an acrylic leveling agent and a dispersing agent is 1-10 mass parts per 100 mass parts of said organic binder (A), respectively. The blending ratio between the acrylic leveling agent and the dispersant is preferably 1:10 to 10: 1.

  Furthermore, if necessary, known and conventional antioxidants, thermal polymerization inhibitors for improving the thermal stability during storage, metal oxides and silicon oxides as a binding component to the substrate during firing Fine particles such as boron oxide can also be added.

  The viscosity of the photosensitive paste of the present invention at 25 ° C. is preferably 50 to 200 dPa · s, more preferably 80 to 180 dPa · s. If the viscosity is lower than 50 dPa · s, dripping or repelling is likely to occur after printing, while if it is higher than 200 dPa · s, the workability is lowered, which is not preferable.

  The photosensitive paste of the present invention is applied to a substrate, for example, a glass substrate to be a back substrate of a PDP by a screen printing method, and then, for example, in a hot air circulation drying oven, a far infrared drying oven, etc. The organic solvent is evaporated by drying at 60 to 120 ° C. for about 5 to 40 minutes to obtain a tack-free coating film. Thereafter, selective exposure, development, and baking are performed to form a predetermined pattern.

As the exposure step, contact exposure and non-contact exposure using a negative mask having a predetermined exposure pattern are possible. As the exposure light source, a halogen lamp, a high-pressure mercury lamp, a laser beam, a metal halide lamp, an electrodeless lamp, or the like is used. The exposure amount is preferably about 50 to 1000 mJ / cm ² .

  As the development process, a spray method, an immersion method, or the like is used. Developers include aqueous alkali metal solutions such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate and sodium silicate, and aqueous amine solutions such as monoethanolamine, diethanolamine and triethanolamine, especially about 1.5% by mass or less. A dilute alkaline aqueous solution having a concentration of 1 is preferably used, as long as the carboxyl group of the carboxyl group-containing resin in the composition is saponified and the uncured part (unexposed part) is removed. It is not limited to. Further, it is preferable to perform washing with water and acid neutralization in order to remove unnecessary developer after development.

  In the baking step, the substrate after development is subjected to heat treatment at about 500 to 600 ° C. in air or in a nitrogen atmosphere to form a desired pattern.

EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, it cannot be overemphasized that this invention is not limited to the following Example. In the following, “parts” are all parts by mass unless otherwise specified.
As the glass powder, a lead-free glass powder composed of Bi ₂ O ₃ , B ₂ O ₃ , ZnO, SiO ₂ and BaO was pulverized to an average particle diameter of 1.6 μm.

  The mixture was blended at the composition ratio shown in Table 1, stirred with a stirrer, and then kneaded with a three-roll mill to form a paste. As a result of measuring the viscosity (dPa · s) of the obtained paste (Composition Examples 1 to 3 and Comparative Examples 1 to 5), they were 158, 171, 165, 162, 177, 150, 162, and 151, respectively. .

Viscosity measuring method Using an E-type viscometer, the viscosity was measured when rotated 5 times at 25 ° C.

  The printing characteristics of the obtained photosensitive paste were examined by the following evaluation method. The results are shown in Table 2 below.

  An evaluation paste was applied on the entire surface of a glass substrate using a 300 mesh polyester screen. At that time, the separation of the screen was observed. Subsequently, it dried for 15 minutes at 90 degreeC with the far-infrared drying oven, and formed the membrane | film | coat. Next, the dried coating film was observed on a light table, and the state of printing unevenness, pinholes and repellency was observed.

  The state of plate separation was evaluated by ○ to ×.

○: Good plate separation △: Part of the screen and the coating film stick together during printing but leaves after printing ×: Part of the screen and coating film sticks together during printing and does not peel off after printing It was evaluated with.

◯: No printing unevenness △: Partly present ×: Printing unevenness large Whether or not there is a pinhole was evaluated by ○ and ×.

○: Almost no pinholes ×: Many pinholes Whether or not there is a repellency was evaluated by ○ and ×.

○: Almost no repelling ×: Many repelling

  As is clear from the results shown in Table 2, the paste according to the composition of the present invention has excellent printability compared to the paste of the comparative composition, and can form a uniform and pinhole-free coating film. It was shown that when 5% by mass or more of a high boiling point organic solvent having a temperature of 210 ° C. or higher is contained, the separation of the plate is improved, which is useful for forming a high-definition electrode with a large screen.

The partial exploded perspective view of a surface discharge type AC type PDP.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Front glass substrate 2a, 2b Display electrode 3a, 3b Transparent electrode 4a, 4b Bus electrode 5 Transparent dielectric layer 6 Protective layer 10 Black pattern 11 Back glass substrate 12 Rib 13 Address electrode 14a, 14b, 14c Phosphor film 100 For PDP Front substrate 100

Claims (4)

A photosensitive paste containing (A) an organic binder, (B) a photopolymerizable monomer, (C) a photopolymerization initiator, (D) inorganic fine particles, (E) an organic solvent, and (F) an additive, contain a solvent (E) high-boiling organic solvents having a boiling point above 210 ° C. during and additive (F) 1, two or more selected from amine and phosphorous-based dispersing agent with an acrylic leveling agent as The photosensitive paste for plasma display panels containing the dispersing agent of.   The photosensitive paste according to claim 1, wherein the content of the high-boiling organic solvent having a boiling point of 210 ° C or higher contained in the organic solvent (E) is 5% by mass or more based on the total amount of the photosensitive paste.   The photosensitive paste of Claim 1 or 2 which contains diethylene glycol monomethyl ether acetate as a high boiling point organic solvent with a boiling point of 210 degreeC or more in an organic solvent (E).   The plasma display panel which has the baked material pattern formed from the baked product of the photosensitive paste of any one of Claims 1 thru | or 3.

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