WO2014065112A1 - 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°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°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 specifically, contains aluminum particles, and is electrically conductive after baking, acid resistance, and adhesion to a substrate. The present invention relates to a conductive composition having excellent properties, an electrode using the composition, a PDP having the electrode, and a touch panel.

Conductive compositions containing aluminum, so-called conductive pastes, have been used as electrode materials in PDPs, solar cells, ceramic capacitors, etc., and are replaced by conductive compositions containing noble metals such as gold and silver in terms of cost. Has been considered as something to do.

In a solar cell, in order to efficiently extract generated electric power, a conductive composition containing aluminum is applied to the back surface of the silicon wafer, that is, the entire surface opposite to the light receiving surface. When this is fired at a high temperature, an aluminum-silicon alloy layer is formed, and a p ⁺ layer in which aluminum is diffused is formed thereunder.

In the PDP, a conductive composition containing aluminum urine is used to form a bus electrode in the display electrode on the front glass substrate and an address electrode on the rear glass substrate. The bus electrode and the address electrode are formed in a stripe shape on each glass substrate and orthogonal to each other. Each of the electrodes is formed with a fine pitch of about several hundreds of μm, but the address electrode is required to have high definition.

In the electrode for PDP, conductivity is an important characteristic for miniaturization and thinning of the electrode pattern and reduction of power consumption. However, aluminum is less conductive than silver or gold. Furthermore, since aluminum easily oxidizes and there is a problem that the conductivity is reduced by oxidation during firing or the like, various solutions have been proposed so far. For example, Patent Document 1 discloses an aluminum-containing photosensitive conductive paste in which the amount of glass powder is relatively large.

Japanese Patent No. 48262962

Since aluminum is easily oxidized, the surface of aluminum particles is covered with a naturally oxidized film. For this reason, the conductive composition usually develops conductivity by burning off the organic component by firing. However, in the conductive resin composition containing aluminum particles, the fusion and binding between the aluminum particle interfaces are still performed after firing. In some cases, the desired conductivity could not be obtained.

On the other hand, in the manufacturing process of the plasma display back plate, a dielectric layer is applied on the address electrodes and fired, and then a barrier rib material (barrier rib) is formed. The partition material is generally processed by chemical etching using an acid, and the etching agent may permeate to reach the address electrode. Therefore, the conductive composition used for the address electrode includes: High acid resistance is required. In addition, if the adhesion between the electrode and the substrate is poor, the electrode may be peeled off, which may cause a product defect. Therefore, the conductive composition is required to have excellent adhesion with the substrate.

Accordingly, an object of the present invention is to provide a conductive composition containing aluminum particles and having excellent conductivity after baking, acid resistance and adhesion to a substrate, and an electrode, PDP and touch panel using this composition. There is.

As a result of intensive studies to solve the above problems, the present inventors have found that the conductive composition containing aluminum particles can solve the above problems by using a resin whose thermal decomposition end point is within a specific temperature range. The headline and the present invention were 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 (B) whose thermal decomposition end point is 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 a cresol novolak. Any one of the resins having a structure is preferable.

Moreover, it is preferable that the conductive composition of the present invention further contains a photosensitive monomer and a photopolymerization initiator.

The electrode of the present invention is obtained by firing one of the above conductive compositions.

The plasma display panel of the present invention has the above-described electrode.

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

According to the present invention, a conductive composition containing aluminum particles and having excellent conductivity after baking, acid resistance, and adhesion to a substrate, an electrode using the composition, and a PDP and a touch panel having the electrode are provided. It becomes possible to provide.
Furthermore, when a line is formed using the conductive composition of the present invention, it is possible to prevent the resistance value from being shifted depending on the width of the line. Such a conductive composition whose resistance value is less likely to fluctuate due to the width of the line is suitable for an electrode of a large PDP.

It is a chart showing the TG-DTA measurement result of resin C used in the examples. FIG. 4 is a graph showing the relationship between line width and resistance value for the conductive compositions of Examples 15 to 19. FIG. 6 is a graph showing the relationship between line width and resistance value for the conductive compositions of Comparative Examples 3 to 7.

The conductive 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. In general, a conductive composition containing metal powder or metal particles burns away a resin component and develops conductivity by binding metals together. If a resin component or a carbonized resin component (hereinafter referred to as residual charcoal) remains after the firing step, bubbles and expansion may occur, and the properties of the inorganic layer may be adversely affected. Therefore, as the resin used for the conductive composition, one having high volatility or one that hardly generates residual carbon after firing has been selectively used. In contrast, the resin as the component (B) of the present invention has a thermal decomposition end point in a relatively high temperature range of 500 to 650 ° C. Thereby, it is considered that at least a part of the resin which is the component (B) of the present invention remains in the composition in a baking step of about 600 ° C., for example. As mentioned above, residual charcoal has been regarded as an undesirable property in conventional conductive compositions. However, the present inventor has 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 after baking, acid resistance, and adhesion to a substrate. It was. Although the detailed mechanism is not necessarily clear, the effect of the present invention is to improve the acid resistance of aluminum particles by protecting the aluminum from acid by covering the particle surface with residual carbon. It can be considered as one of the reasons to explain. Moreover, it is thought that residual charcoal contributes also to adhesiveness with a base material. Furthermore, it is considered that the conductivity is improved in order to suppress the growth of the oxide film covering the aluminum particles by the remaining carbon.
Hereinafter, each component will be described in detail.

[Aluminum particles]
(A) Aluminum particle will not be restrict | limited especially if it is used for an electroconductive composition, All can use a well-known thing. (A) The average particle diameter (D50) of the aluminum particles is preferably 1 to 6 μm, and more preferably 2 to 5 μm. When the average particle diameter of the aluminum particles is within the above range, the volume balance between the aluminum particles and the resin can be achieved, the coating with the component (B) is sufficiently achieved, and the effects of the present invention can be obtained favorably. Further, the specific surface area of the aluminum particles is in an appropriate range, and the influence of aluminum oxidation can be suppressed.
The average particle diameter of aluminum can be measured, for example, as D50 in a weight distribution curve measured by a laser diffraction particle size distribution measuring apparatus.
The content of (A) aluminum particles is preferably 70 to 520 parts by mass, and more preferably 100 to 400 parts by mass, when the component (B) is 100 parts by mass.
(A) As aluminum particle, the aluminum particle manufactured by the nitrogen gas atomizing method is preferable. The nitrogen gas atomization method is a method in which a molten metal is blown into fine particles by blowing nitrogen gas as a fluid to a molten metal (aluminum) in a nitrogen atmosphere to obtain a metal powder by solidifying the droplets. There is no particular limitation.

[Resin whose thermal decomposition end point is in the range of 500 to 650 ° C.]
The resin according to the component (B) of the present invention is a resin having a thermal decomposition end point in the range of 500 to 650 ° C. Preferably, it is 550 to 650 ° C.
The resin according to the component (B) of the present invention functions as a binder. The pyrolysis end point is measured using a TG measuring device (thermogravimetric measuring device) or a TG-DTA measuring device (thermogravimetric-suggested thermal simultaneous measuring device) to measure the weight change of the resin sample due to the temperature rise. A TG curve in which weight change is plotted against time (temperature) is prepared, and is defined as a temperature at which weight loss due to heating is not observed.
Further, the weight average molecular weight of the resin varies depending on the resin skeleton, but is preferably in the range of 2,000 to 150,000, more preferably 5,000 to 100,000. When the weight average molecular weight is within the above range, it is possible to suppress deterioration of tack-free performance, deterioration of moisture resistance of the coated film after exposure, film reduction during development, and deterioration of resolution. Moreover, the deterioration of developability and storage stability can be suppressed.

Examples of the resin that can be used as the component (B) include phenoxy resins such as bisphenol A type phenoxy resin, bisphenol F type phenoxy resin, bisphenol A / bisphenol F copolymer type phenoxy resin, and bisphenol A type epoxy resin. Bisphenol F type epoxy resin, bisphenol A / bisphenol F copolymer type epoxy resin, epoxy acrylate resin obtained by acrylic modification of the end of the epoxy resin, polyvinyl acetal resin such as polyvinyl butyral resin , Polyester resins, block copolymers and the like. (B) The resin concerning a component may be used individually by 1 type, and may use 2 or more types together.
As the component (B), any one of a resin having a bisphenol structure in the main chain, a polyvinyl acetal resin, a phenol novolac resin, and a cresol novolac resin is preferable. Moreover, since an electroconductive composition can be made into a photocurable composition, resin which has an ethylenically unsaturated double bond is preferable. Further, the resin of the present invention may be a carboxyl group-containing resin having a side chain modified with a carboxylic acid in order to enable alkali development.

The phenoxy resin is a polyhydroxy polyether obtained from a reaction between a divalent phenol compound and an epihalohydrin or obtained by reacting a divalent epoxy compound with 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, a phenoxy resin having a bisphenol M structure, a phenoxy resin having a bisphenol P structure, Examples thereof include a phenoxy resin having a bisphenol structure, such as a phenoxy resin having a bisphenol Z structure. In addition, a phenoxy resin having a skeleton structure such as a novolak structure, an anthracene structure, a fluorene structure, a dicyclopentadiene structure, a norbornene structure, a naphthalene structure, a biphenyl structure, an adamantane structure, or the like can be given. As said skeleton structure, you may have multiple types. Of the above, those having a bisphenol structure are preferred.

The above epoxy resin is a polyfunctional epoxy compound having two or more epoxy groups (oxirane rings) in one molecule, or a resin obtained by polymerizing the polyfunctional epoxy compound. Examples of the polyfunctional epoxy compounds include epoxidized vegetable oils; bisphenol A type epoxy resins; hydroquinone type epoxy resins, bisphenol type epoxy resins, thioether type epoxy resins; brominated epoxy resins; novolac type epoxy resins; biphenol novolac type epoxy resins; F type epoxy resin; hydrogenated bisphenol A type epoxy resin; glycidylamine type epoxy resin; hydantoin type epoxy resin; alicyclic epoxy resin; trihydroxyphenylmethane type epoxy resin; bixylenol type or biphenol type epoxy resin or a mixture thereof Bisphenol S type epoxy resin; bisphenol A novolac type epoxy resin; tetraphenylol ethane type epoxy resin; heterocyclic epoxy resin; Ruphthalate resin; Tetraglycidylxylenoylethane resin; Naphthalene group-containing epoxy resin; Epoxy resin having dicyclopentadiene skeleton; Glycidyl methacrylate copolymer epoxy resin; Copolymer epoxy resin of cyclohexylmaleimide and glycidyl methacrylate; Examples thereof include, but are not limited to, polybutadiene rubber derivatives and CTBN-modified epoxy resins. These epoxy resins can be used alone or in combination of two or more. Among these, bisphenol type epoxy resins are particularly preferable.

The epoxy acrylate resin is a resin obtained by reacting the epoxy resin with (meth) acrylic acid or a derivative thereof having an ethylenically unsaturated group and a carboxyl group in the molecule. Moreover, the carboxyl group-containing resin which made the polybasic acid anhydride react and added the carboxyl group may be sufficient. For example, it is an epoxy acrylate resin having a bisphenol structure obtained by modifying (meth) acrylic acid an epoxy resin having a bisphenol structure such as bisphenol A or bisphenol F.

Specific examples of the carboxyl group-containing resin include the following compounds (any of oligomers and polymers).
(1) Reaction product obtained by reacting a reaction product obtained by reacting a compound having a plurality of phenolic hydroxyl groups in one molecule with an alkylene oxide such as ethylene oxide or propylene oxide, with an unsaturated group-containing monocarboxylic acid. A carboxyl group-containing photosensitive resin obtained by reacting a product with a polybasic acid anhydride.

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

(3) A carboxyl obtained by reacting (meth) acrylic acid with a polyfunctional epoxy resin obtained by epoxidizing the hydroxyl group of a bifunctional (solid) epoxy resin with epichlorohydrin and adding a dibasic acid anhydride to the resulting hydroxyl group Group-containing photosensitive resin.

(4) A difunctional acid such as adipic acid, phthalic acid or hexahydrophthalic acid is reacted with a bifunctional oxetane resin, and the resulting primary hydroxyl group has two bases such as phthalic anhydride, tetrahydrophthalic anhydride or hexahydrophthalic anhydride. A carboxyl group-containing non-photosensitive polyester resin to which an acid anhydride is added.

(5) A carboxyl group-containing photosensitive resin obtained by adding a compound having one epoxy group and one or more (meth) acryloyl groups in one molecule to the resins (1) to (4).
In addition, in this specification, (meth) acrylate is a term which generically refers to acrylate, methacrylate and a mixture thereof, and the same applies to other similar expressions.

Since the carboxyl group-containing resin as described above has a large number of carboxyl groups in the side chain of the backbone polymer, development with a dilute alkaline aqueous solution becomes possible.
The acid value of the carboxyl group-containing resin is suitably in the range of 40 to 200 mgKOH / g, more 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 good, while when it is 200 mgKOH / g or less, dissolution of the exposed portion by the developer is suppressed, and the line becomes thinner than necessary. Occurrence of a phenomenon such as dissolution and peeling with a developer without distinction between an exposed part and an unexposed part can be suppressed, and a normal electrode pattern can be easily drawn.

The polyvinyl acetal resin can be obtained by acetalizing a polyvinyl alcohol resin with an aldehyde. The aldehyde is not particularly limited. For example, formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, amylaldehyde, hexylaldehyde, heptylaldehyde, 2-ethylhexylaldehyde, cyclohexylaldehyde, furfural, benzaldehyde, 2-methylbenzaldehyde, 3- Examples include methylbenzaldehyde, 4-methylbenzaldehyde, p-hydroxybenzaldehyde, m-hydroxybenzaldehyde, phenylacetaldehyde, β-phenylpropionaldehyde, and the like, butyraldehyde is preferred. These aldehydes may be used alone or in combination of two or more. As the polyvinyl acetal resin, polyvinyl butyral resin is preferable.

The polyester resin is preferably a polymer-type copolymerized aromatic polyester resin.
The block copolymer is preferably an ABA or ABA ′ type block copolymer. A or A ′ preferably includes polymethyl (meth) acrylate (PMMA), polystyrene (PS) or the like, and B preferably includes poly n-butyl acrylate (PBA) or polybutadiene (PB).

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

(Other resins)
The electrically conductive composition of this invention may contain other resin other than resin concerning the said (B) component in the range which does not impair the effect of this invention. Examples of the other resin include resins that have been used as organic binders in conductive compositions so far and have a thermal decomposition end point outside the range of 500 to 650 ° C.
Examples of such organic binders include various modified polyester resins such as polyester resins, urethane-modified polyester resins, epoxy-modified polyester resins, and acrylic-modified polyester resins, polyether urethane resins, polycarbonate urethane resins, acrylic urethane resins, vinyl chloride, Vinyl acetate copolymer, epoxy resin, phenolic resin, acrylic resin, polyvinyl butyral resin, polyamideimide, polyimide, polyamide, nitrocellulose, cellulose acetate butyrate (CAB), modified cellulose such as cellulose acetate propionate (CAP) And the like.

(Photosensitive monomer)
The conductive composition of the present invention preferably contains a photosensitive monomer in order to impart photocurability to the composition and enable pattern formation by development. The photosensitive monomer is a compound having an ethylenically unsaturated bond in the molecule, and is used for viscosity adjustment, acceleration of photocurability and improvement of developability. As such a compound, conventionally known polyester (meth) acrylate, polyether (meth) acrylate, urethane (meth) acrylate, carbonate (meth) acrylate, epoxy (meth) acrylate, urethane (meth) acrylate can be used, Specifically, hydroxyalkyl acrylates such as 2-hydroxyethyl acrylate and 2-hydroxypropyl acrylate; diacrylates of glycols such as ethylene glycol, methoxytetraethylene glycol, polyethylene glycol, and propylene glycol; N, N-dimethylacrylamide Acrylamides such as N-methylolacrylamide and N, N-dimethylaminopropylacrylamide; N, N-dimethylaminoethyl acrylate, N Aminoalkyl acrylates such as N-dimethylaminopropyl acrylate; polyhydric alcohols such as hexanediol, trimethylolpropane, pentaerythritol, dipentaerythritol, tris-hydroxyethyl isocyanurate, or ethylene oxide adducts thereof, propylene oxide adducts Or polyhydric acrylates such as ε-caprolactone adduct; polyhydric acrylates such as phenoxy acrylate, bisphenol A diacrylate, and ethylene oxide adduct or propylene oxide adduct of these phenols; glycerin diglycidyl ether, glycerin Such as triglycidyl ether, trimethylolpropane triglycidyl ether, triglycidyl isocyanurate Polyacid acrylates of lysidyl ether; not limited to the above, acrylates and melamine acrylates obtained by directly acrylated polyols such as polyether polyols, polycarbonate diols, hydroxyl-terminated polybutadienes, polyester polyols, or urethane acrylates via diisocyanates , And at least one of each methacrylate corresponding to the acrylate.
When blended, the preferred blending amount is preferably 5 to 200 parts by weight per 100 parts by weight of component (B).

(Photopolymerization initiator)
The conductive composition of the present invention preferably contains a photopolymerization initiator in order to impart photosensitivity to the composition and enable pattern formation by development. As the photopolymerization initiator, any known photopolymerization initiator can be used, and among them, an oxime ester photopolymerization initiator having an oxime ester group, an α-aminoacetophenone photopolymerization initiator, and an acylphosphine oxide photopolymerization initiator. Initiators and titanocene photopolymerization initiators are preferred. A photoinitiator may be used individually by 1 type and may be used in combination of 2 or more type.

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

(Wherein R ¹ represents a hydrogen atom, a phenyl group (which may be substituted with an alkyl group having 1 to 6 carbon atoms, a phenyl group, or a halogen atom), an alkyl group having 1 to 20 carbon atoms (one or more). Or a cycloalkyl group having 5 to 8 carbon atoms, an alkanoyl group having 2 to 20 carbon atoms, or benzoyl. Represents a group (which may be substituted with an alkyl group having 1 to 6 carbon atoms or a phenyl group), and R ² is a phenyl group (substituted with 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 with one or more hydroxyl groups, and may have one or more oxygen atoms in the middle of the alkyl chain), carbon number 5 -8 cycloalkyl groups, It represents an alkanoyl group or a benzoyl group primes 2-20 (carbon atoms may be substituted with an alkyl group or a phenyl group having 1 to 6).)

Examples of commercially available oxime ester photopolymerization initiators include CGI-325, Irgacure (registered trademark) OXE01, Irgacure OXE02 manufactured by BASF Japan, N-1919 manufactured by ADEKA, and Adeka Arcles (registered trademark) NCI- 831 etc. are mentioned.

When the oxime ester photopolymerization initiator is used, the blending amount is preferably 0.01 to 5 parts by mass with respect to 100 parts by mass of the component (B). If it is 0.01 mass part or more, photocurability will become enough and the fall of cured | curing material characteristics, such as peeling of cured | curing material and chemical resistance, can be suppressed. On the other hand, if it is 5 parts by mass or less, excessive light absorption on the surface of the cured product can be avoided, and deep curability can be ensured. More preferably, it is 0.5 to 3 parts by mass with respect to 100 parts by mass of component (B).

Specific examples of the α-aminoacetophenone photopolymerization initiator include 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropanone-1, 2-benzyl-2-dimethylamino-1 -(4-morpholinophenyl) -butan-1-one, 2- (dimethylamino) -2-[(4-methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone, N, N-dimethylaminoacetophenone and the like can be mentioned. Examples of commercially available products include Irgacure 907, Irgacure 369, and Irgacure 379 manufactured by BASF Japan.

Specific examples of the acylphosphine oxide photopolymerization initiator include 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, and bis (2,6-dimethoxy). And benzoyl) -2,4,4-trimethyl-pentylphosphine oxide. Examples of commercially available products include Lucillin (registered trademark) TPO, Irgacure 819 manufactured by BASF Japan.

In the case of using an α-aminoacetophenone photopolymerization initiator or an acylphosphine oxide photopolymerization initiator, the blending amount thereof is 0.01 to 15 parts by mass with respect to 100 parts by mass of component (B). preferable. If it is 0.01 mass part or more, photocurability will become enough and the fall of cured | curing material characteristics, such as peeling of cured | curing material and chemical resistance, can be suppressed. On the other hand, if it is 15 parts by mass or less, the effect of reducing outgas is sufficient, and further, light absorption on the surface of the cured product can be avoided, and deep curability can be ensured. More preferably, it is 0.5 to 10 parts by mass with respect to 100 parts by mass of component (B).

Also, as the photopolymerization initiator, Irgacure 389 manufactured by BASF Japan Ltd. and Irgacure 784 which is a titanocene photopolymerization initiator can be suitably used.

In addition to the photopolymerization initiator, a photoinitiator aid or a sensitizer can be suitably used. Examples of the photoinitiation assistant or sensitizer include benzoin compounds, acetophenone compounds, anthraquinone compounds, thioxanthone compounds, ketal compounds, benzophenone compounds, tertiary amine compounds, and xanthone compounds. These compounds may be used as a photopolymerization initiator in some cases, but are preferably used in combination with a photopolymerization initiator. Moreover, a photoinitiator auxiliary or a sensitizer may be used individually by 1 type, and may use 2 or more types together.

(Glass frit)
Since the conductive composition of the present invention is excellent in adhesiveness to a substrate without containing glass frit, the content of glass frit can be reduced. However, the glass frit may be included in a small amount. Since high electroconductivity is obtained, it is preferable not to include glass frit.
Although it does not specifically limit as glass frit, The thing which has lead oxide, bismuth oxide, zinc oxide, lithium oxide, or an alkali borosilicate as a main component is used.

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, more preferably 0.5 to 3.0 μm. If the average particle size is 0.3 μm or more, the yield can be secured and it can be avoided that the cost is high. It is possible to easily reduce the deterioration of the line shape and the denseness.

The softening point of a glass frit is excellent in electroconductivity by being 550 degrees C or less, for example.

The blending amount when glass frit is included is not particularly limited, but is preferably 15% by mass or less, more preferably 4% by mass or less, and most preferably 0% in the entire composition. If the amount of the glass frit having a high softening point is not excessive, a decrease in adhesion can be suppressed.

Furthermore, a dispersing agent may be added in order to uniformly disperse the glass frit in the conductive composition. The dispersant is not particularly limited as long as the glass frit can be uniformly dispersed in the conductive composition. Dispersants include polycarboxylic acid type polymer surfactants, modified acrylic block copolymers, acrylic copolymers having pigment affinity groups, block copolymers having basic or acidic pigment adsorbing groups, pigments Modified polyalkoxylate having affinity group, combination of polyaminoamide salt and polyester, or combination of polar acid ester and high molecular alcohol, alkyl ammonium salt of acidic polymer, high molecular weight block copolymer having pigment affinity group, special Examples include modified urea. The said dispersing agent may be used individually by 1 type, and may use 2 or more types together.

(fatty acid)
The conductive composition of the present invention may contain a fatty acid. By containing a fatty acid, an improvement in storage stability can be expected. The fatty acid may be either a saturated fatty acid or an unsaturated fatty acid, but is preferably an unsaturated fatty acid having two or more unsaturated bonds. Specific examples of fatty acids include behenic acid, oleic acid, linolenic acid, stearic acid, thiodiacetic acid and the like. When the fatty acid is blended, the blending amount is preferably 0.1 to 5 with respect to 100 parts by mass of the component (B).

(Stabilizer)
The conductive composition of the present invention can be added with a stabilizer other than the above fatty acid in order to improve the storage stability of the composition and to suppress the deterioration of the coating workability due to the gelation and fluidity deterioration. . As the stabilizer, a compound having an effect of complexing with aluminum or forming a salt in the conductive composition can be used. Specifically, for example, various inorganic acids such as nitric acid, sulfuric acid, hydrochloric acid, boric acid; various organic acids such as formic acid, acetic acid, acetoacetic acid, citric acid, phthalic acid, benzenesulfonic acid, sulfamic acid; phosphoric acid, nitrous acid Phosphoric acid, hypophosphorous acid, methyl phosphate, ethyl phosphate, butyl phosphate, phenyl phosphate, ethyl phosphite, diphenyl phosphite, mono (2-methacryloyloxyethyl) acid phosphate, di (2-methacryloyl) Examples thereof include acids such as various phosphoric acid compounds (inorganic phosphoric acid, organic phosphoric acid) such as oxyethyl) acid phosphate, and phosphoric acid, phosphoric acid ester and organic acid are preferable. Examples of commercially available products include light ester P-1M (manufactured by Kyoeisha Chemical Co., Ltd.). The said stabilizer may be used individually by 1 type, and may use 2 or more types together.

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

(solvent)
The conductive composition of the present invention may contain an organic solvent in order to adjust the viscosity of the composition. Any known organic solvent can be used as long as it can dissolve the resin of component (B). For example, toluene, xylene, ethyl acetate, butyl acetate, methanol, ethanol, isopropyl alcohol, isobutyl alcohol, 1-butanol, diacetone alcohol, ethylene glycol monobutyl ether, propylene glycol monoethyl ether, propylene glycol monomethyl 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)
As long as the effects of the present invention are not impaired, the conductive composition of the present invention can be blended with components generally blended in the aluminum-containing conductive composition used for forming electrodes and electrical wiring. Examples of such components include binders, colorants, surface treatment agents, antifoaming agents, leveling agents, surface tension reducing agents, diluents, plasticizers, fillers, coupling agents, antioxidants, and dispersants. It is done. Moreover, electroconductive powder other than aluminum, such as silver particles and copper particles, may be included.
The photosensitive conductive composition of the present invention can be paste-formed by kneading with a three-roll mill or the like.

<Electrode>
The electrode of the present invention is formed using the conductive composition of the present invention. An example of an electrode forming method will be described below. However, it is not limited to this.

The conductive composition of the present invention can be applied by screen printing, for example, to a glass substrate serving as a front substrate of a PDP in a predetermined pattern, and then baked to form a PDP electrode.

In addition, when photosensitivity is imparted to the conductive composition of the present invention, a pattern can be formed by a photolithography method. For example, the conductive composition of the present invention is applied to a glass substrate by an appropriate application method such as a screen printing method, a bar coder, or a blade coater to form a coating film. Next, the obtained coating film is dried in a hot-air circulating drying oven, a far-infrared drying oven or the like, for example, at about 70 to 120 ° C. for about 5 to 40 minutes to evaporate the organic solvent in order to obtain a touch-drying property. A tack-free coating (dry coating) is formed. At this time, when the conductive composition is previously applied on the film and dried to form a dry film, the dry film may be laminated on the substrate.

The resulting dried coating film is subjected to pattern exposure. As an exposure method, 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, a black lamp, an electrodeless lamp, or the like is used. The exposure amount is preferably about 100 to 800 mJ / cm ² . Further, exposure can also be performed using a direct drawing apparatus using a laser oscillation light source having a maximum wavelength of 350 to 420 nm.

Furthermore, the coating film exposed to a predetermined pattern is developed. As a developing method, a spray method, a dipping method or the like is used. As the developer, for example, a metal alkali aqueous solution such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium silicate, or an amine aqueous solution such as monoethanolamine, diethanolamine, or triethanolamine, particularly about 1.5 wt%. A dilute alkaline aqueous solution having the following concentration is preferably used. Moreover, it is preferable to perform washing with water and acid neutralization in order to remove an unnecessary developer after development.

In the firing step, the glass substrate on which the conductive composition of the present invention is patterned is preferably 650 ° C. or less, more preferably about 400 to 650 ° C., and still more preferably about 500 to 500 ° C. in an air atmosphere or a nitrogen atmosphere. Heat treatment is performed at 600 ° C. to form a desired electrode. At this time, the temperature rising rate is preferably set to 20 ° C./min or less. When the firing temperature is 650 ° C. or lower, the disappearance of residual charcoal can be prevented.
The electrode of the present invention can be suitably used for a PDP or a touch panel, but is not limited thereto. As the electrode for the touch panel, a lead-out wiring electrode can be mentioned.

Hereinafter, the present invention will be specifically described by way of examples. However, the present invention is not limited to the following examples and comparative examples.

(TG-DTA)
For each of the resins listed in Table 1 below, the weight change of the resin sample as the temperature increased was measured using a TG-DTA measuring device (manufactured by Seiko Instruments Inc.).
The measurement temperature condition was room temperature to 600 ° C., and the temperature was maintained for 30 minutes. The temperature raising condition was 20 ° C./min. The temperature at which no weight reduction was observed was defined as the end point of thermal decomposition. The obtained results are shown in Table 1 below. For the resin C, the obtained chart is shown in FIG.

* 1: THPA-modified carboxyl group-containing resin of trisphenylmethane epoxy acrylate * 2: Carboxylic acid-modified carboxyl group-containing resin of bisphenol F-type epoxy acrylate * 3: Carboxylic acid-modified carboxyl group-containing resin of bisphenol F-type epoxy acrylate * 4 : Polyvinyl butyral resin * 5: Bisphenol A type phenoxy resin * 6: Bisphenol A type polyester resin * 7: Copolymer resin of butyl acrylate and methyl methacrylate * 8: Addition of HHPA to copolymer of methacrylate and BG methacrylate (hexahydrophthalic acid Anhydrous) carboxyl group-containing resin

(Examples 1 to 10, Comparative Example 1)
(Preparation of conductive composition)
Each component was mixed in the ratio shown in Table 2 below, and kneaded with a three-roll mill to prepare a conductive composition. The unit of the blending amount in the table is part by mass.

* 1: Average particle size 2 μm, manufactured by N ₂ atomization method * 2: Average particle size 4 μm, manufactured by N ₂ atomization method * 3: Average particle size 6 μm, manufactured by N ₂ atomization method * 4: Average particle size 2 μm, Manufactured by atmospheric atomization method * 5: Average particle size 2.5μm
* 6: THPA (1,2,3,6-tetrahydrophthalic anhydride) modified carboxyl group-containing resin of trisphenylmethane epoxy acrylate, thermal decomposition end temperature = 591 ° C
* 7: Carboxylic acid-modified carboxyl group-containing resin of bisphenol F type epoxy acrylate, thermal decomposition end temperature = 592 ° C.
* 8: Carboxylic acid-modified carboxyl group-containing resin of bisphenol F type epoxy acrylate, thermal decomposition end temperature = 592 ° C.
* 9: Polyvinyl butyral resin, thermal decomposition end temperature = 595 ° C
* 10: Bisphenol A type phenoxy resin, thermal decomposition end temperature = 597 ° C
* 11: Bisphenol A type polyester resin, thermal decomposition end temperature = 603 ° C.
* 12: Copolymerized resin of butyl acrylate and methyl methacrylate, thermal decomposition end temperature = 594 ° C
* 13: Carboxyl group-containing resin obtained by adding HHPA (hexahydrophthalic anhydride) to copolymerization of methacrylate and BG (butyl glycidyl) methacrylate, thermal decomposition end temperature = 474 ° C.
* 14: Aminoacetophenone photopolymerization initiator * 15: Trifunctional EO-modified trimethylolpropane triacrylate * 16: Polyester acrylate * 17: Hydrocarbon aromatic solvent

(Production of test pieces of Examples 1 to 3, 8 to 10 and Comparative Examples 1 and 2)
Each conductive composition for evaluation was applied on the entire surface of a glass substrate using a 200-mesh polyester screen, and then dried at 80 ° C. for 20 minutes in a hot-air circulating drying oven to provide a touch-drying property. A good coating film was formed. Thereafter, using a metal halide lamp as a light source, exposure was performed so that the integrated light amount on the composition was 300 mJ / cm ² . Finally, baking was performed at 580 to 600 ° C. for 30 minutes to produce a test piece on which an electrode was formed.

(Preparation of test pieces of Examples 4 to 7)
Each conductive composition for evaluation was applied on the entire surface of a glass substrate using a 200-mesh polyester screen, and then dried in a hot-air circulating drying oven at 80 ° C. for 20 minutes for good touch drying properties. A good coating was formed. Thereafter, it was baked at 580 to 600 ° C. for 30 minutes to produce a test piece on which an electrode was formed.

Specific resistance value:
The test piece (0.1 cm × 40 cm) was measured by a four-probe method by attaching a four-probe probe (PSP) for a micro sample to a Loresta GP manufactured by Mitsubishi Chemical Analytic. The thickness of the sample was measured using a Mitutoyo Digimatic Micrometer (MDC-25MJ).

Adhesion:
With respect to the test piece (2 cm × 5 cm), 25 coating films were cut into a 1 mm-interval grid according to the cross-cut method (JIS K-5600). Adhesion was evaluated according to the state when a tape was applied and peeled off. Comparative Example 2 was not evaluated because acid resistance was not obtained.
Not peeled at all: ◎,
Part of the surface layer is peeled off: 〇,
The entire surface peels off: △,
The whole peels off from the substrate interface: ×

Acid resistance:
The test piece was immersed in a 0.3% by mass nitric acid aqueous solution for 10 minutes. Thereafter, the acid resistance was evaluated in the same manner as the evaluation of adhesion.
Not peeled at all: ◎,
Part of the surface layer is peeled off: 〇,
The entire surface peels off: △,
The whole peels 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 conductive composition for evaluation was applied on the entire surface of a glass substrate using a 200-mesh polyester screen, and then dried at 80 ° C. for 20 minutes in a hot-air circulating drying oven to provide a touch-drying property. A good coating film was formed. Thereafter, using a metal halide lamp as a light source and using a negative mask having a line width of 40 μm and 20 μm, exposure was performed so that the integrated light amount on the composition was 300 mJ / cm ^2, and then 0.4 wt% Na at a liquid temperature of 30 ° C. Development was performed using a ₂ CO ₃ aqueous solution at a development time of 10 seconds or 20 seconds, washed with water, and dried with an air knife. Thereafter, baking was performed at 580 to 600 ° C. for 30 minutes.
Regarding the test piece, whether or not a 40 μm line and a 20 μm line could be formed was observed, and the minimum line width was selected. Comparative Example 2 was not evaluated because acid resistance was not obtained.

(Examples 11 and 12)
In the same manner as in the above examples, each component was blended as shown in Table 4 below to prepare and evaluate a photosensitive conductive resin composition. The obtained results are shown in Table 5 below.

* 1: Average particle size of 2 μm, manufactured by N ₂ atomization method * 2: Carboxylic acid-modified carboxyl group-containing resin of bisphenol F type epoxy acrylate, thermal decomposition end temperature = 592 ° C.
* 3: Aminoacetophenone photopolymerization initiator * 4: Trifunctional EO-modified trimethylolpropane triacrylate * 5: Polyester acrylate * 6: Softening point 515 ° C, organic solvent and thixotropic agent mixture * 7: Softening point 595 ° C, Mixing organic solvent and thixotropic agent

(Examples 13 and 14)
In the same manner as in the above Examples, each component was blended as shown in Table 6 below, and a photosensitive conductive composition was prepared and evaluated. The obtained results are shown in Table 7 below.

* 1: Average particle size of 2 μm, manufactured by N ₂ atomization method * 2: Carboxylic acid-modified carboxyl group-containing resin of bisphenol F type epoxy acrylate, thermal decomposition end temperature = 592 ° C.
* 3: Softening point 515 ° C, organic solvent and thixotropic agent mixture * 4: Aminoacetophenone photopolymerization initiator * 5: Trifunctional EO-modified trimethylolpropane triacrylate * 6: Polyester acrylate * 7: Hydrocarbon aromatic solvent

(Measurement method of resistance value in each line width)
(Example 15)
On the glass substrate, the conductive composition of Example 3 was applied to the entire surface using a 200-mesh polyester screen, and then dried at 80 ° C. for 20 minutes in a hot-air circulating drying oven to provide a touch-drying property. A good coating film was formed. Then, using a metal halide lamp as a light source, using a negative mask with a line width of 70, 80, 90, 100, 110, and 120 μm, exposure was performed so that the integrated light amount on the composition was 300 mJ / cm ^2, and then the liquid temperature Development was performed using a 0.4 wt% Na ₂ CO ₃ aqueous solution at 30 ° C. with a development time of 10 seconds or 20 seconds, washed with water, and dried with an air knife. Then, it baked for 30 minutes at 600 degreeC.
In each line width pattern, a resistance value of 100 cm in length was measured. The resistance values at that time are shown in FIG. 2 together with the resistance values of Examples 16 to 19 below.
(Example 16)
Except that the composition of Example 3 was mixed with glass frit A (softening point 515 ° C., mixed with organic solvent and thixotropic agent) so as to be 3% of the total amount of the composition, and the conductive composition was prepared. Same as Example 15.
(Example 17)
Example 16 was the same as Example 16 except that the content of the glass frit A was 7% of the total amount of the composition.
(Example 18)
Except that the composition of Example 3 was mixed with glass frit B (softening point 595 ° C., mixed with organic solvent and thixotropic agent) so as to be 3% of the total amount of the composition, and the conductive composition was prepared. Same as Example 15.
(Example 19)
Example 18 was the same as Example 18 except that the content of the glass frit B was 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 values are shown in FIG. 3 together with the resistance values of Comparative Examples 4 to 7 below.
(Comparative Example 4)
Comparative Example 1 except that the composition of Comparative Example 1 was mixed with glass frit A (softening point 515 ° C., mixed with organic solvent and thixotropic agent) so as to be 3% of the total amount of the composition. Same as Example 3.
(Comparative Example 5)
It was the same as Comparative Example 4 except that the content of glass frit A was 6% of the total amount of the composition.
(Comparative Example 6)
Comparative Example 1 except that the composition of Comparative Example 1 was mixed with glass frit B (softening point 595 ° C., mixed with organic solvent and thixotropic agent) so as to be 3% of the total amount of the composition. Same as Example 3.
(Comparative Example 7)
It was the same as Comparative Example 6 except that the content of glass frit B was 6% of the total amount of the composition.

(Comparative Examples 8 to 10, Examples 20 to 22)
In the same manner as in the above example, each component was blended as shown in Table 8 below to prepare a photosensitive conductive resin composition, and a test piece on which a line width pattern was formed in the same manner as in the above example 15 was used. The acid resistance was evaluated. The obtained results are shown in Table 9 below. In addition, the numerical value in the parenthesis of the blending amount of the glass frit is mass% with respect to the whole composition.

* 1: Average particle size 2 μm, manufactured by N ₂ atomization method * 2: Average particle size 2.5 μm
* 3: Carboxylic acid-modified carboxyl group-containing resin of bisphenol F type epoxy acrylate, thermal decomposition end temperature = 592 ° C.
* 4: Carboxyl group-containing resin obtained by adding HHPA (hexahydrophthalic anhydride) to the copolymerization of methacrylate and BG methacrylate, thermal decomposition end temperature = 474 ° C
* 5: Aminoacetophenone photopolymerization initiator * 6: Trifunctional EO-modified trimethylolpropane triacrylate * 7: Polyester acrylate * 8: Softening point 515 ° C, organic solvent and thixotropic agent mixture * 9: Softening point 595 ° C, Mixing organic solvent and thixotropic agent

Claims (6)

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

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