TW201428773A - Conductive composition, electrode, plasma display panel and touch panel - Google Patents

Abstract

Provided are: a conductive composition which contains aluminum particles and exhibits excellent electrical conductivity, acid resistance and adhesion to a base after firing and an electrode which uses this conductive composition. A conductive composition which is characterized by containing (A) aluminum particles and (B) a resin that has a thermal decomposition end temperature within the range of 500-650 DEG C. It is preferable that the conductive composition additionally contains a photosensitive monomer and a photopolymerization initiator. It is also preferable that the resin (B) that has a thermal decomposition end temperature within the range of 500-650 DEG C is a resin having a bisphenol structure, a polyvinyl acetal resin, a resin having a phenolic novolac structure, or a resin having a cresol novolac structure.

Description

Conductive composition, electrode, plasma display panel and touch panel

The present invention relates to a conductive composition, an electrode, a plasma display panel (hereinafter also referred to as "PDP"), and a touch panel, and more particularly to an aluminum-containing particle, which is electrically conductive, acid-resistant, and base-based after firing. A conductive composition excellent in adhesion of a material, an electrode using the composition, a PDP having the electrode, and a touch panel.

The conductive composition containing aluminum, which is a conductive paste, has been used as an electrode material among PDPs, solar cells, ceramic capacitors, etc., and has been reviewed as a gold or silver in the past. A substitute for the conductive composition of these precious metals.

In order to efficiently obtain the electric power generated by the solar cell, an aluminum-containing conductive composition is applied to the back surface of the germanium wafer, that is, the entire surface opposite to the light receiving surface. If it is fired at a high temperature, aluminum will be formed. The tantalum alloy layer is further formed with a p ⁺ layer of aluminum diffusion under it.

In the PDP, an aluminum-containing conductive composition is used to form an auxiliary electrode in the display electrode on the front glass substrate and an address electrode on the back glass substrate. Auxiliary electrode, address electrode is on each glass substrate The strips are striped and formed perpendicular to each other. Further, any of the electrodes is formed with a fine pitch of about several hundred μm, but it is particularly required that the addressed electrode has high definition.

Among the electrodes for PDP, conductivity is an important characteristic in terms of miniaturization or thinning of the electrode pattern, reduction in power consumption, and the like. However, aluminum is less conductive than silver or gold. Even aluminum has a problem that it is easily oxidized, and oxidation during firing or the like causes a decrease in conductivity. Therefore, various methods have been proposed in the literature. For example, Patent Document 1 discloses an aluminum-containing photosensitive conductive paste having a large amount of glass powder.

Prior technical literature Patent literature

Patent Document 1: Japanese Patent No. 4862692

Since aluminum is easily oxidized, the surface of the aluminum particles is covered by a naturally oxidized film. Therefore, the conductive composition usually burns the organic component by firing to exhibit conductivity. However, in the conductive resin composition containing aluminum particles, the interface between the aluminum particles does not fuse after firing. If it is closed, there will be a situation where the desired conductivity cannot be obtained.

On the other hand, in the manufacturing step of the plasma display back sheet, after the dielectric layer is applied to the address electrode and fired, a barrier rib is formed. The partition wall material is generally shaped by chemical etching using an acid, and an etchant is infiltrated into the addressed electrode. It is a concern that the conductive composition used for the address electrode is required to have high acid resistance. Further, when the adhesion between the electrode and the substrate is not good, peeling of the electrode or the like may occur, which may cause a defect in the product. Therefore, it is required that the conductive composition and the substrate have excellent adhesion.

Accordingly, an object of the present invention is to provide a conductive composition containing aluminum particles, which is excellent in electrical conductivity, acid resistance, and adhesion to a substrate after firing, an electrode using the composition, a PDP, and a touch panel.

In order to solve the above problems, the present inventors have found that by using a resin having a thermal decomposition end point in a specific temperature range among the conductive compositions containing aluminum particles, the above problems can be solved and the present invention can be completed. .

That is, the conductive composition of the present invention is characterized by containing (A) aluminum particles and (B) a resin having a thermal decomposition end point in the range of 500 to 650 °C.

In the conductive composition of the present invention, the resin having the (B) thermal decomposition end point in the range of 500 to 650 ° C is a resin having a bisphenol structure, a polyvinyl acetal resin, a resin having a phenol novolak structure, and Any of the resins of the cresol novolac structure is preferred.

Further, the conductive composition of the present invention preferably contains a photosensitive monomer and a photopolymerization initiator.

The electrode of the present invention is characterized in that the conductive composition of any of the above is fired.

A plasma display panel of the present invention is characterized by having the above electrode.

The touch panel of the present invention is characterized by having the above electrode.

According to the present invention, it is possible to provide a conductive composition containing aluminum particles, which is excellent in conductivity, acid resistance, and adhesion to a substrate after firing, an electrode using the composition, and a PDP having the electrode. Control panel.

Further, in the case where the conductive material is formed using the conductive composition of the present invention, it is possible to suppress the resistance value from fluctuating depending on the magnitude of the line width. The conductive composition whose resistance value does not easily vary with the line width is suitable for the electrode of a large PDP.

Fig. 1 is a graph showing the results of TG-DTA measurement of the resin C used in the examples.

Fig. 2 is a graph showing the relationship between the line width and the electric resistance value of the electroconductive compositions of Examples 15 to 19.

Fig. 3 is a graph showing the relationship between the line width and the electric resistance value of the electroconductive compositions of Comparative Examples 3 to 7.

The electroconductive composition of the present invention is characterized by containing aluminum particles and a resin having a thermal decomposition end point in the range of 500 to 650 °C. A conductive composition containing metal powder or metal particles is generally burned to burn a resin component The metals are bonded to each other to exhibit electrical conductivity. After the baking step, if the resin component or the carbonized resin component (hereinafter referred to as residual carbon) remains, bubbles or swelling may occur, which may adversely affect the characteristics of the inorganic layer. Therefore, the resin used for the conductive composition has been selected from those having high volatility or being hard to generate residual carbon after firing. On the other hand, the resin of the component (B) of the present invention has a thermal decomposition end point in a relatively high temperature region of 500 to 650 °C. Thereby, the resin of the component (B) of the present invention is considered to have at least a part of the resin remaining in the composition in the firing step of, for example, about 600 °C. As described above, among the conventional conductive compositions, residual carbon has been considered to be an unsuitable property. However, the present inventors have found that a conductive composition containing a resin having a thermal decomposition end point in the range of 500 to 650 ° C is excellent in conductivity, acid resistance, and adhesion to a substrate after firing. In the case of aluminum particles, the surface of the particles is covered with residual carbon, which protects the aluminum from acid contact and enhances acid resistance. It is considered to be one of the reasons for explaining the effects of the present invention, but the detailed mechanism is not known. It is also believed that residual carbon also contributes to adhesion to the substrate. Further, in order to suppress the growth of the oxide film covering the aluminum particles caused by the residual carbon, it is also conceivable to improve the conductivity. The components are described in detail below.

[aluminum particles]

(A) The aluminum particles are not particularly limited as long as they can be used for the conductive composition, and any of the well-known ones can be used. The average particle diameter (D50) of the aluminum particles (A) is preferably 1 to 6 μm, more preferably 2 to 5 μm. If the average particle diameter of the aluminum particles is within the above range, the volume of the aluminum particles and the resin is obtained. In the balance, the coating produced by the component (B) is sufficient, and the effects of the present invention can be satisfactorily obtained. Further, the specific surface area of the aluminum particles is in an appropriate range, and the influence of oxidation of aluminum can be suppressed.

The average particle diameter of aluminum can be measured by D50 in a weight distribution curve obtained by, for example, a laser diffraction type particle size distribution measuring apparatus.

(A) The content of the aluminum particles is preferably from 70 to 520 parts by mass, more preferably from 100 to 400 parts by mass, based on 100 parts by mass of the component (B).

(A) The aluminum particles are preferably aluminum particles produced by a nitrogen atomization method. The nitrogen atomization method is not limited to a method in which a metal (aluminum) melt is made into a fluid in a nitrogen atmosphere, and a nitrogen gas is blown to finely pulverize the melt to form a droplet and solidify it to obtain a metal powder. Specially limited.

[Resin with a thermal decomposition end point in the range of 500 to 650 ° C]

The resin to which the component (B) of the present invention is related is a resin having a thermal decomposition end point in the range of 500 to 650 °C. It should be 550~650°C.

The resin to which the component (B) of the present invention is associated can function as a binder. The thermal decomposition end point is defined as a change in weight of a resin sample caused by an increase in temperature using a TG measuring device (thermogravimetric measuring device) or a TG-DTA measuring device (thermogravimetric-differential heat simultaneous measuring device), and the change in weight with respect to time The (TG) curve was plotted to produce a TG curve, and the temperature at which the weight was reduced by heating was no longer observed.

In addition, the weight average molecular weight of the resin may vary depending on the resin skeleton, and is generally in the range of 2,000 to 150,000, further A range of 5,000 to 100,000 is preferred. When the weight average molecular weight is within the above range, deterioration of non-sticking performance, deterioration of moisture resistance of the coating film after exposure, film loss at the time of development, and deterioration of resolution can be suppressed. In addition, deterioration in development or storage stability can be suppressed.

Examples of the resin which can be used as the component (B) include a phenoxy group such as a bisphenol A type phenoxy resin, a bisphenol F type phenoxy resin, and a copolymerized phenoxy resin of bisphenol A/bisphenol F. An epoxy resin such as a resin, a bisphenol A epoxy resin, a bisphenol F epoxy resin, or a copolymerization type of bisphenol A/bisphenol F, or an epoxy obtained by denaturation of acrylic acid at the end of the epoxy resin A polyvinyl acetal resin such as an acrylate resin or a polyvinyl butyral resin, a polyester resin, a block copolymer or the like. The resin to which the component (B) is related may be used singly or in combination of two or more.

The component (B) is preferably a resin having a bisphenol structure in its main chain, a polyvinyl acetal resin, a phenol novolak type resin, and a cresol novolac type resin. Further, from the viewpoint that the conductive composition can be made into a photocurable composition, a resin having an ethylenically unsaturated double bond is preferred. Further, in order to enable alkali development of the resin of the present invention, a carboxyl group-containing resin obtained by denaturation of a side chain carboxylic acid may be used.

The phenoxy resin is a polyhydroxy polyether obtained by a reaction of a divalent phenol compound with an epihalohydrin or a divalent epoxy compound and a divalent phenol compound. Examples of the divalent phenol compound include bisphenols. Examples of the phenoxy resin include a phenoxy resin having a bisphenol A structure (skeleton), a phenoxy resin having a bisphenol F structure, a phenoxy resin having a bisphenol S structure, and a benzene having a bisphenol M structure. Oxygen resin with bisphenol P A phenoxy resin having a bisphenol structure such as a phenoxy resin having a structure or a phenoxy resin having a bisphenol Z structure. Other examples include a phenoxy resin having a skeleton structure such as a phenolic structure, a fluorene structure, a fluorene structure, a dicyclopentadiene structure, a norbornene structure, a naphthalene structure, a biphenyl structure, or an adamantane structure. A variety of the above skeleton configurations are also possible. Among the above, it is desirable to have a bisphenol structure.

The epoxy resin is a resin obtained by polymerizing a polyfunctional epoxy compound having two or more epoxy groups (oxirane rings) in one molecule or the polyfunctional epoxy compound. The polyfunctional epoxy compound may, for example, be an epoxidized vegetable oil; a bisphenol A type epoxy resin; a hydroquinone type epoxy resin, a bisphenol type epoxy resin, a thioether type epoxy resin; a brominated epoxy resin; a phenolic type ring; Oxygen resin; biphenol novolac type epoxy resin; bisphenol F type epoxy resin; hydrogenated bisphenol A type epoxy resin; glycidyl amine type epoxy resin; hydantotype epoxy resin; alicyclic epoxy resin ; trihydroxyphenylmethane type epoxy resin; dixylenol type or biphenol type epoxy resin or a mixture of the same; bisphenol S type epoxy resin; bisphenol A phenolic type epoxy resin; tetraphenol B Alkyl epoxy resin; heterocyclic epoxy resin; diglycidyl phthalate resin; tetraglycidyl decyl phenol resin; naphthalene-containing epoxy resin; epoxy having a dicyclopentadiene skeleton Resin; glycidyl methacrylate copolymerized epoxy resin; copolymerized epoxy resin of cyclohexylmaleimide and glycidyl methacrylate; polybutadiene rubber derivative modified by epoxy , CTBN modified epoxy resin, etc., without being limited by these. These epoxy resins may be used singly or in combination of two or more. Among these, a bisphenol type epoxy resin is particularly preferable.

The epoxy acrylate-based resin is a resin obtained by reacting the epoxy resin and (meth)acrylic acid or a derivative thereof having an ethylenically unsaturated group and a carboxyl group in the molecule. Further, it may be a carboxyl group-containing resin obtained by reacting a polybasic acid anhydride to form a carboxyl group. For example, an epoxy acrylate resin having a bisphenol structure obtained by denaturation of (meth)acrylic acid with an epoxy resin having a bisphenol structure such as bisphenol A or bisphenol F is used.

Specific examples of the carboxyl group-containing resin include the following compounds (any of an oligomer and a polymer).

(1) A compound having a plurality of phenolic hydroxyl groups in one molecule is reacted with an alkylene oxide such as ethylene oxide or propylene oxide, and the obtained reaction product is generated with a monocarboxylic acid containing an unsaturated group. The reaction is carried out, and then the obtained reaction product is reacted with a polybasic acid anhydride to obtain a carboxyl group-containing photosensitive resin.

(2) A carboxyl group-containing photosensitive resin obtained by reacting a bifunctional or higher polyfunctional (solid) epoxy resin with (meth)acrylic acid to form a dibasic acid anhydride in a hydroxyl group of a side chain.

(3) further epoxidizing the hydroxyl group of the bifunctional (solid) epoxy resin with epichlorohydrin, reacting the formed polyfunctional epoxy resin with (meth)acrylic acid, and adding a 2-salt group to the generated hydroxyl group. A carboxyl group-containing photosensitive resin obtained from an acid anhydride.

(4) reacting a bifunctional oxetane resin with a dicarboxylic acid such as adipic acid, citric acid or hexahydrophthalic acid to form a hydrazine anhydride, tetrahydrophthalic anhydride, or a hexahydrophthalic acid A carboxyl group-containing non-photosensitive polyester resin obtained by a dibasic acid anhydride such as hydroquinone anhydride.

(5) The carboxyl group-containing photosensitive resin obtained by further adding a compound having one epoxy group and one or more (meth)acryl fluorenyl groups in one molecule to the resin of the above (1) to (4).

Further, in the present specification, (meth) acrylate means a term collectively referred to as acrylate, methacrylate, and the like, and other similar expressions are also the same.

Since the carboxyl group-containing resin as described above has a plurality of carboxyl groups in the side chain of the main polymer, it can be visualized by a dilute aqueous alkali solution.

Further, the acid value of the carboxyl group-containing resin is suitably in the range of 40 to 200 mgKOH/g, preferably in the range of 45 to 120 mgKOH/g. When the acid value of the carboxyl group-containing resin is 40 mgKOH/g or more, the alkali developability is improved. On the other hand, when it is 200 mgKOH/g or less, the dissolution of the exposed portion is suppressed by the developing liquid, and the wire can be suppressed. If it is more than necessary, or if the exposed portion is not separated from the unexposed portion and the developing solution is dissolved and peeled off, the normal electrode pattern can be easily drawn.

The polyvinyl acetal resin is obtained by acetalizing a polyvinyl alcohol resin with an aldehyde. The aldehyde is not particularly limited, and examples thereof include formaldehyde, acetaldehyde, ketone aldehyde, butyraldehyde, valeraldehyde, hexanal, heptaldehyde, 2-ethylhexanal, cyclohexanal, furaldehyde, benzaldehyde, and the like. 2-methylbenzaldehyde, 3-methylbenzaldehyde, 4-methylbenzaldehyde, p-hydroxybenzaldehyde, m-hydroxybenzaldehyde, phenylacetaldehyde, β-phenylpentanone aldehyde, etc., preferably butyraldehyde. These aldehydes may be used alone or in combination of two or more. The polyvinyl acetal resin is preferably a polyvinyl butyral resin.

The above polyester resin is a polymer type copolymerized aromatic polyester resin. good. The above block copolymer is preferably an A-B-A or A-B-A' type block copolymer. A or A' is preferably composed of poly(methyl) methacrylate (PMMA), polystyrene (PS), etc., and B contains polybutyl acrylate (PBA), polybutadiene (PB), etc. It is better.

The component (B) is preferably a resin having an aromatic ring, and particularly preferably a resin having a bisphenol structure, a resin having a phenol novolak structure, and a resin having a cresol novolac structure. Further, the component (B) is preferably a phenoxy resin, a polyvinyl acetal resin, a polyester resin or a block copolymer. Among these, a phenoxy resin, a polyvinyl acetal resin, and a polyester resin are preferable.

(other resin)

The conductive composition of the present invention may contain other resins than the resin to which the component (B) is concerned, insofar as the effects of the present invention are not impaired. Examples of the other resin include resins which have been used as an organic binder among the conductive compositions in the past, and which have a thermal decomposition end point outside the range of 500 to 650 °C.

Examples of such an organic binder include various modified polyester resins such as a polyester resin, an urethane-modified polyester resin, an epoxy-modified polyester resin, an acrylic modified polyester resin, a polyether urethane resin, and a poly Carbonate urethane resin, urethane acrylate resin, vinyl chloride-vinyl acetate copolymer, epoxy resin, phenol resin, acrylic resin, polyvinyl butyral resin, polyamidoximine, poly Amine, polyamine, nitrocellulose, cellulose. Acetate. Butyrate (CAB), cellulose. Acetate. C Denatured celluloses such as acid esters (CAP).

(photosensitive monomer)

In order to impart photocurability to the composition, the conductive composition of the present invention preferably contains a photosensitive monomer which can be patterned by development. The photosensitive monomer is a compound having an ethylenically unsaturated bond in the molecule, and is used to adjust viscosity, promote photocurability, or enhance developability. As such a compound, conventional and well-known polyester (meth) acrylate, polyether (meth) acrylate, urethane (meth) acrylate, carbonate (meth) acrylate, epoxy can be used. (meth) acrylate and ethyl urethane (meth) acrylate, specific examples thereof include hydroxyalkyl acrylates such as 2-hydroxyethyl acrylate and 2-hydroxypropyl acrylate; ethylene glycol and methoxy Diacrylates of glycols such as tetraethylene glycol, polyethylene glycol, and propylene glycol; N,N-dimethyl decylamine, N-methylol acrylamide, N,N-dimethylamine Acrylamides such as propyl acrylamide; amide alkyl acrylates such as N,N-dimethylaminoethyl acrylate and N,N-dimethylaminopropyl acrylate; hexanediol, trishydroxyl Polyol such as propane, pentaerythritol, dipentaerythritol, cis-hydroxyethyl isocyanurate or the like, or such ethylene oxide adduct, propylene oxide adduct, or ε-caprolactone adduct And other polyvalent acrylates; phenoxy acrylate, bisphenol A diacrylate, and polyvalent acrylates such as ethylene oxide adducts or propylene oxide adducts of these phenols; Multivalent acrylates of glycidyl ethers such as oleo-glycidyl ether, glycerol triglycidyl ether, trimethylolpropane triglycidyl ether, triglycidyl isocyanurate, etc.; not limited to the above To make polyether polyols, polycarbonate diols, Polyols such as hydroxy-terminated polybutadiene and polyester polyol are directly acrylated, or acrylates and melamine acrylates which are acrylated by diisocyanate, and acrylates corresponding to the above acrylates At least any one of methacrylates and the like.

In the case of blending, a suitable blending amount is preferably 5 to 200 parts by mass per 100 parts by mass of the component (B).

(photopolymerization initiator)

In order to impart sensitivity to the composition, it is possible to form a pattern by development, and the conductive composition of the present invention preferably contains a photopolymerization initiator. The photopolymerization initiator may be any of known ones, and among them, an oxime ester photopolymerization initiator having an oxime ester group, an α-aminoacetophenone photopolymerization initiator, a mercaptophosphine oxide system A photopolymerization initiator and a titanocene photopolymerization initiator are preferred. The photopolymerization initiator may be used alone or in combination of two or more.

The oxime ester photopolymerization initiator is a photopolymerization initiator having a partial structure (an oxime group) represented by the following general formula (1).

(wherein R ¹ represents a hydrogen atom, a phenyl group (which may be substituted by an alkyl group having 1 to 6 carbon atoms, a phenyl group or a halogen atom), or an alkyl group having 1 to 20 carbon atoms (may be substituted by one or more hydroxyl groups) , the middle of the alkyl chain may have more than one oxygen atom), the cycloalkyl group having 5 to 8 carbon atoms, the alkyl fluorenyl group having 2 to 20 carbon atoms or the benzhydryl group (the alkyl group having a carbon number of 1 to 6) Or a phenyl group); R ² represents a phenyl group (which may be substituted by an alkyl group having 1 to 6 carbon atoms, a phenyl group or a halogen atom), or an alkyl group having 1 to 20 carbon atoms (which may be substituted by one or more hydroxyl groups). The middle of the alkyl chain may have one or more oxygen atoms), the cycloalkyl group having 5 to 8 carbon atoms, the alkyl alkene group having 2 to 20 carbon atoms or the benzamidine group (alkyl group having 1 to 6 carbon atoms) Or phenyl substituted))

The oxime ester photopolymerization initiator, commercially available products include CGI-325 manufactured by BASF Japan Co., Ltd., Irgacure (registered trademark) OXE01, Irgacure OXE02, N-1919 manufactured by ADEKA, and Adeka Arkls (registered trademark) NCI-831. Wait.

In the case of using an oxime ester photopolymerization initiator, the blending amount is preferably 0.01 to 5 parts by mass based on 100 parts by mass of the component (B). When the amount is 0.01 parts by mass or more, the photocurability is sufficient, and deterioration of the cured product such as peeling of the cured product or chemical resistance can be suppressed. On the other hand, when it is 5 parts by mass or less, excessive light absorption on the surface of the cured product can be avoided, and the hardenability in the deep portion can be ensured. It is preferably 0.5 to 3 parts by mass based on 100 parts by mass of the component (B).

The α-aminoacetophenone photopolymerization initiator is specifically 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinylacetone-1, 2- Benzyl-2-dimethylamino-1-(4-morpholinylphenyl)-butan-1-one, 2-(dimethylamino)-2-[(4-methylphenyl) Methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone, N,N-dimethylaminoacetophenone and the like. Commercially available products include Irgacure 907, Irgacure 369, and Irgacure 379 manufactured by BASF Japan.

A mercaptophosphine oxide photopolymerization initiator, specifically 2,4,6-trimethylbenzimidyldiphenylphosphine oxide, bis(2,4,6-trimethylbenzylidene)-phenylphosphine oxide, bis(2,6-dimethoxy Benzobenzhydryl)-2,4,4-trimethyl-pentylphosphine oxide and the like. Commercially available products include LUCIRIN (registered trademark) TPO and Irgacure 819 manufactured by BASF Japan.

In the case of using an α-aminoacetophenone photopolymerization initiator or a mercaptophosphine oxide photopolymerization initiator, each blending amount is 0.01 to 15 by mass based on 100 parts by mass of the component (B). It is better. When the amount is 0.01 parts by mass or more, the photocurability is sufficient, and deterioration of the cured product such as peeling of the cured product or chemical resistance can be suppressed. On the other hand, if it is 15 parts by mass or less, the effect of reducing the fugitive gas is sufficient, and further, the light absorption on the surface of the cured product can be prevented from being excessive, and the hardenability in the deep portion can be ensured. It is preferably 0.5 to 10 parts by mass based on 100 parts by mass of the component (B).

Further, as the photopolymerization initiator, Irgacure-389 manufactured by BASF Japan Co., Ltd., or Irgacure-784 of a titanocene photopolymerization initiator is suitably used.

In addition to the photopolymerization initiator, photoinitiating aids or sensitizers are also suitable. Examples of the photoinitiator or the sensitizer include a benzoin compound, an acetophenone compound, an anthraquinone compound, a thioxanthone compound, a ketal compound, a benzophenone compound, a tertiary amine compound, and a ketone compound. These compounds are also used as a photopolymerization initiator, and are preferably used in combination with a photopolymerization initiator. Further, the photoinitiating aid or the sensitizer may be used alone or in combination of two or more.

(glass frit)

Since the conductive composition of the present invention does not contain a glass frit, it is excellent in adhesion to a substrate, so that the content of the glass frit can be reduced. However, if there is only a small amount, it can also contain glass frit. From the viewpoint of obtaining high conductivity, it is preferred that the glass frit is not contained.

The glass frit is not particularly limited, and those containing lead oxide, cerium oxide, zinc oxide, lithium oxide, or alkali borosilicate can be used as a main component.

The average particle diameter (D50) of the glass particles can be measured by a laser diffraction-scattering method, and is preferably 0.3 to 5.0 μm, preferably 0.5 to 3.0 μm. When the average particle diameter is 0.3 μm or more, the yield can be ensured, and the cost can be avoided. On the other hand, if it is 5.0 μm or less, the film can be easily formed or easily shrunk uniformly, and the shape or density of the wire can be suppressed. Sexual deterioration.

By setting the softening point of the glass frit to, for example, 550 ° C or lower, conductivity can be excellent.

In the case of containing a glass frit, the blending amount is not particularly limited, and is preferably 15% by mass or less, preferably 4% by mass or less, and most preferably 0%, based on the entire composition. As long as the amount of the glass frit having a high softening point is not excessive, the decrease in the adhesion can be suppressed.

Further, in order to uniformly disperse the glass frit in the conductive composition, a dispersing agent may be added. The dispersing agent is not particularly limited as long as the glass frit can be uniformly dispersed in the conductive composition. Examples of the dispersant include a polycarboxylic acid type polymer surfactant, a denatured acrylic block copolymer, an acrylic copolymer having a pigment affinity group, a block copolymer having a basic or acidic pigment adsorption group, and a pigment affinity. Combination of denatured polyalkoxylates, polyamine guanamine salts and polyesters, or polar acid esters and high molecular alcohols A combination of an alkylammonium salt of an acidic polymer, a high molecular weight block copolymer having a pigment affinity group, a specially modified urea, and the like. These dispersing agents may be used alone or in combination of two or more.

(fatty acid)

The conductive composition of the present invention may also contain a fatty acid. By containing fatty acids, it is expected that the preservation stability will be improved. The fatty acid may be either a saturated fatty acid or an unsaturated fatty acid, and is preferably an unsaturated fatty acid having two or more unsaturated bonds. Specific examples of the fatty acid include behenic acid, oleic acid, linoleic acid, stearic acid, thiodiacetic acid, and the like. In the case of blending a fatty acid, the blending amount is preferably 0.1 to 5 parts by mass based on 100 parts by mass of the component (B).

(stabilizer)

In order to improve the storage stability of the composition, it is possible to suppress the deterioration of the colloidal property or the fluidity, and the coating workability is deteriorated. The conductive composition of the present invention may be added with a stabilizer other than the above fatty acid. The stabilizer may be a compound having an effect of causing misalignment or formation of a salt with aluminum in the conductive composition. Specific examples thereof include various inorganic acids such as nitric acid, sulfuric acid, hydrochloric acid, and boric acid; various organic acids such as formic acid, acetic acid, acetamidine acetic acid, citric acid, citric acid, benzenesulfonic acid, and sulfamic acid; and phosphoric acid and phosphorous acid. , hypophosphorous acid, methyl phosphate, ethyl phosphate, butyl phosphate, phenyl phosphate, ethyl phosphite, diphenyl phosphite, mono(2-methylpropenyloxyethyl) acid phosphate, Acids such as various phosphoric acid compounds (inorganic phosphoric acid, organic phosphoric acid) such as bis(2-methylpropenyloxyethyl) acid phosphate, and phosphoric acid and phosphorus Acid esters and organic acids are preferred. Commercially available products include Lightester P-1M (manufactured by Kyoeisha Chemical Co., Ltd.) and the like. These stabilizers may be used alone or in combination of two or more.

The blending amount of the stabilizer is preferably 0.05 to 10 parts by mass, preferably 0.1 to 5 parts by mass, per 100 parts by mass of the component (B).

(solvent)

In order to adjust the viscosity of the composition, the conductive composition of the present invention may also contain an organic solvent. As long as the organic solvent can dissolve the resin associated with the component (B), a well-known and conventional one can be used. For example, toluene, xylene, ethyl acetate, butyl acetate, methanol, ethanol, isopropanol, isobutanol, 1-butanol, diacetone alcohol, ethylene glycol monobutyl ether, propylene glycol monoethyl ether, propylene glycol single Methyl ether acetate, terpineol, methyl ethyl ketone, carbitol, carbitol acetate, butyl carbitol, butyl carbitol acetate, and the like. Two or more of these may be included as necessary.

(other additives)

The conductive composition of the present invention may be blended with a component which is generally blended with the aluminum-containing conductive composition used for forming an electrode or an electric wiring, as long as the effect of the present invention is not impaired. Examples of such a component include a binder, a colorant, a surface treatment agent, an antifoaming agent, a leveling agent, a surface tension reducing agent, a diluent, a plasticizer, a filler, a coupling agent, an antioxidant, a dispersing agent, and the like. Further, a conductive powder other than aluminum such as silver particles or copper particles may be contained.

Further, the photosensitive conductive composition of the present invention can be obtained by a three-roll mill Wait for mixing and paste.

<electrode>

The electrode of the present invention is formed using the conductive composition of the present invention. Examples of the method of forming the electrode are as follows. But it is not limited by it.

The conductive composition of the present invention is applied to a glass substrate as a front plate of a PDP in a predetermined pattern by screen printing, and then fired to form an electrode for PDP.

Further, in the case where the photosensitive composition of the present invention is provided with photosensitivity, pattern formation can be carried out by photolithography. For example, the conductive composition of the present invention is applied onto a glass substrate by a suitable coating method such as a screen printing method, a bar coater or a knife coater to form a coating film. Next, in order to make the obtained coating film have dryness to the touch, it is dried in a hot air circulating drying oven, a far-infrared drying oven, etc., for example, at about 70 to 120 ° C for about 5 to 40 minutes to evaporate the organic solvent. Non-stick coating (dry coating). In this case, when the conductive composition is applied to the film in advance and dried to form a dry film, the dry film may be laminated on the substrate.

Next, the obtained dried coating film pattern is exposed. The exposure method may be contact exposure and non-contact exposure using a negative mask having a predetermined exposure pattern. The exposure light source may be a halogen lamp, a high pressure mercury lamp, a laser beam, a metal halide lamp, a black light lamp, an electrodeless lamp or the like. The exposure amount is preferably about 100 to 800 mJ/cm ² . Alternatively, exposure can be performed using a direct drawing device using a laser excitation light source having a maximum wavelength of 350 to 420 nm.

Further, the exposure film is exposed to a predetermined pattern to be developed. The development method may employ a spray method, a dipping method, or the like. The developing solution is preferably a metal alkali aqueous solution such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate or sodium citrate, or an aqueous amine solution such as monoethanolamine, diethanolamine or triethanolamine, especially about 1.5% by weight or less. A concentrated aqueous solution of dilute alkali. Further, in order to remove an unnecessary developing liquid after development, it is preferred to carry out water washing or acid neutralization.

In the firing step, the conductive composition of the present invention is formed in an air atmosphere or a nitrogen atmosphere, preferably at 650 ° C or lower, preferably about 400 to 650 ° C, more preferably about 500 to 600 ° C. The patterned glass substrate is subjected to a heat treatment to form a desired electrode. Further, at this time, the temperature increase rate is preferably set to 20 ° C / min or less. By setting the firing temperature to 650 ° C or lower, the disappearance of residual carbon can be prevented.

The electrodes of the present invention are suitable for use in PDPs or touch panels, but are not limited by them. The electrode for the touch panel can be cited as a lead wire electrode.

[Examples]

The present invention will be specifically described below in the examples, but the present invention is not limited by the following examples and comparative examples.

(TG-DTA)

For each of the resins described in the following Table 1, a TG-DTA measuring device (manufactured by Seiko Instruments Co., Ltd.) was used to measure the change in weight of the resin sample as the temperature increased.

The temperature is measured from room temperature to 600 ° C and is maintained at the temperature reached. 30 minutes. Further, the temperature rising condition was set to 20 ° C / min. The temperature at which weight reduction is no longer observed is defined as the end point of thermal decomposition. The results obtained are disclosed in Table 1 below. Further, the pattern obtained by the resin C is shown in Fig. 3 .

(Examples 1 to 10, Comparative Example 1) (modulation of conductive composition)

The components were mixed at a ratio shown in the following Table 2, and kneaded in a three-roll mill to prepare a conductive composition. The unit of the blending amount in the table is parts by mass.

(Production of test pieces of Examples 1 to 3, 8 to 10, and Comparative Examples 1 and 2)

Each of the conductive compositions for evaluation was applied to the entire surface of the glass substrate using a 200 mesh polyester mesh, and then dried in a hot air circulating drying oven at 80 ° C for 20 minutes to form a good touch dryness. Coating film. Then, exposure was performed using a metal halide lamp as a light source and making the cumulative amount of light on the composition 300 mJ/cm ² . Finally, it was baked at 580 to 600 ° C for 30 minutes to prepare a test piece in which an electrode was formed.

(Production of test pieces of Examples 4 to 7)

Each of the conductive compositions for evaluation was applied to the entire surface of the glass substrate using a 200 mesh polyester mesh, and then dried in a hot air circulating drying oven at 80 ° C for 20 minutes to form a good touch dryness. Coating film. Then, it was baked at 580 to 600 ° C for 30 minutes to prepare a test piece in which an electrode was formed.

Specific resistance value:

A four-point probe (PSP) for a micro sample was attached to a Loresta GP manufactured by Mitsubishi Chemical Analytech, and the test piece (0.1 cm × 40 cm) was measured by a four-point probe method. The film thickness of the sample was measured using a digital micrometer (MDC-25MJ) manufactured by Mitutoyo.

Adhesion:

According to the cross cutting method (JIS K-5600), in the test piece (2cm × The coating film of 5 cm) was engraved with 25 grids of 1 mm intervals. The tape was attached thereto, and the adhesion was evaluated from the state after the tearing. Further, in Comparative Example 2, acid resistance could not be obtained, and therefore it was not evaluated.

No peeling at all: ◎, part of the surface layer peeled off: ○, the whole surface peeling: △, the whole peeling off from the substrate interface: ×

Acid resistance: The test piece was immersed in a 0.3% by mass aqueous solution of nitric acid for 10 minutes. The acid resistance was then evaluated in the same manner as the above evaluation of the adhesion.

No peeling at all: ◎, part of the surface layer peeled off: ○, the whole surface peeling: △, the whole peeling off from the substrate interface: ×

Resolution:

(Production of Test Pieces of Examples 1 to 3, Examples 8 to 10, and Comparative Examples 1 and 2)

Each of the conductive compositions for evaluation was applied to the entire surface of the glass substrate using a 200 mesh polyester mesh, and then dried in a hot air circulating drying oven at 80 ° C for 20 minutes to form a good touch dryness. Coating film. Then, using a metal halide lamp as a light source, a negative mask having a line width of 40 μm and 20 μm was used, and the cumulative amount of light on the composition was 300 mJ/cm ² for exposure, and then 0.4 wt% Na ₂ at a liquid temperature of 30 ° C was used. For the CO ₃ aqueous solution, the development time was set to 10 seconds or 20 seconds for development, and after washing with water, it was dried with an air knife. Then, it was baked at 580 to 600 ° C for 30 minutes.

It is observed whether a 40 μm line and a 20 μm line can be formed on the test piece, and the minimum line width is selected. Further, since Comparative Example 2 failed to obtain acid resistance, it was not evaluated.

(Examples 11, 12)

In the same manner as in the above Example, each component was blended as described in the following Table 4, and a photosensitive conductive resin composition was produced and evaluated. The results obtained are disclosed in Table 5 below.

(Examples 13, 14)

In the same manner as in the above Example, each component was blended as described in the following Table 6, and a photosensitive conductive composition was produced and evaluated. estimate. The results obtained are disclosed in Table 7 below.

(Method for measuring the resistance value of each line width) (Example 15)

The conductive composition of Example 3 was coated on the entire surface of the glass substrate using a 200 mesh polyester mesh, and then dried in a hot air circulating drying oven at 80 ° C for 20 minutes to form a good touch dryness. Coating film. Then, using a metal halide lamp as a light source, a negative type mask having a line width of 70, 80, 90, 100, 110, and 120 μm was used, and the integrated light amount on the composition was 300 mJ/cm ² for exposure, and then the liquid temperature was used. The development time was set to 10 seconds or 20 seconds for a development time of a 0.4 wt% Na ₂ CO ₃ aqueous solution at 30 ° C, and after water washing, it was dried with an air knife. It was then baked at 600 ° C for 30 minutes.

A resistance value of 100 cm in length was measured for each line width pattern. The resistance value at this time is shown together with the resistance values of the following Examples 16 to 19 in Fig. 2 .

(Embodiment 16)

In the composition of Example 3, the glass was blended at 3% of the total amount of the composition. The same procedure as in Example 15 was carried out except that the glass material A (softening point: 515 ° C, organic solvent and a rocking agent was mixed) to prepare a conductive composition.

(Example 17)

The same procedure as in Example 16 was carried out except that the content of the glass frit A was set to 7% of the total amount of the composition.

(Embodiment 18)

In the composition of Example 3, the glass frit B (softening point: 595 ° C, organic solvent and a rocking agent) was blended in an amount of 3% of the total amount of the composition to prepare a conductive composition, and other examples were carried out. Example 15 is the same.

(Embodiment 19)

The same procedure as in Example 18 was carried out except that the content of the glass frit B was set to 7% of the total amount of the composition.

(Comparative Example 3)

The resistance value was measured in the same manner as in Example 15 except that the conductive composition of Comparative Example 1 was used instead of Example 3. The resistance value is shown in Fig. 3 together with the resistance values of Comparative Examples 4 to 7 below.

(Comparative Example 4)

In the composition of Comparative Example 1, the glass frit A was blended with 3% of the total amount of the composition (softening point 515 ° C, organic solvent mixed with a shaker), and prepared. The same procedure as in Comparative Example 3 was carried out except that the conductive composition was produced.

(Comparative Example 5)

The content of the glass frit A was determined to be 6% of the total amount of the composition, except that it was the same as in Comparative Example 4.

(Comparative Example 6)

In the composition of Comparative Example 1, glass frit B (softening point 595 ° C, organic solvent mixed with a rocking agent) was blended at 3% of the total amount of the composition to prepare a conductive composition, and other comparisons were made. Example 3 is the same.

(Comparative Example 7)

The content of the glass frit B was determined to be 6% of the total amount of the composition, and otherwise the same as Comparative Example 6.

(Comparative Examples 8 to 10, Examples 20 to 22)

In the same manner as in the above-mentioned Example, each component was blended as described in the following Table 8, and a photosensitive conductive resin composition was produced. Similarly to the above-described Example 15, a test piece having a line width pattern was used. Evaluate acid resistance. The results obtained are disclosed in Table 9 below. Further, the numerical value in the parentheses of the blending amount of the glass frit is the mass % with respect to the entire composition.

Claims (6)

A conductive composition characterized by comprising (A) aluminum particles and (B) a resin having a thermal decomposition end point in the range of 500 to 650 °C. The conductive composition of claim 1, wherein the resin having the (B) thermal decomposition end point in the range of 500 to 650 ° C is a resin having a bisphenol structure, a polyvinyl acetal resin, a resin having a phenol novolac structure, and Any of the resins of cresol novolac structure. The conductive composition of claim 1 or 2, which further comprises a photosensitive monomer and a photopolymerization initiator. An electrode characterized by firing the conductive composition according to any one of claims 1 to 3. A plasma display panel characterized by having an electrode as in claim 4. A touch panel characterized by having an electrode as in claim 4.