JP2002260442A - Conductive paste - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a circuit material having good resistance to flex and connector resistance in a thin-film circuit. SOLUTION: This conductive paste is characterized in that conductive powder (A), a cellulose derivative (B) as a binder and the other organic resins (C) are contained. It is preferred that the conductive powder (A) contains silver powder alone or silver powder not less than 60% by weight, preferably not less than 70% by weight and more preferably not less than 80% by weight. The cellulose derivative (B) contains, for example, celluloseacetatebutylate(CAB) and celluloseacetate(CA) and the like. Suitable other organic resin added has molecular weight not less than 3000 but its sort is not limited.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductive paste, and more particularly, to applying a conductive paste on a film or a substrate, or printing and curing the conductive paste to impart conductivity, thereby forming a circuit or forming an electronic circuit. Adhesion of the terminals and lead wires of parts and the prevention of electromagnetic interference (E
MI), which is related to conductive paste used to protect from electrical shocks, especially for circuits that require excellent connector insertion / removal resistance, connector blocking resistance, high conductivity, bending resistance, and fine pattern printability. It relates to a suitable conductive paste.

[0002]

2. Description of the Related Art A membrane circuit formed by printing a conductive paste on a PET film or the like is low-cost and lightweight, and is widely used for keyboards and switches. However, the required characteristics are becoming stricter year by year, and a higher degree of bending resistance than before, resistance to insertion / extraction when using a connector, resistance to blocking, and printability of fine patterns are required. In particular, with respect to the insertion / extraction resistance and the blocking resistance when the connector is mounted, the finer the pitch of the connector terminals, the smaller the crimping area needs to provide strength, and the local pressure is considerable, which is a severe condition.
At present, there is no connector having sufficient connector resistance even at the expense of bending resistance.

[0003]

As a known conductive paste, there is JP-A-59-206459. This is a silver paste for a membrane circuit using a polybutadiene-based resin and a blocked isocyanate compound obtained by blocking an isocyanate group with an oxime-based compound or caprolactam as a binder, but has relatively good bending resistance. However, a considerably soft binder is used to provide bending resistance, and the connector insertion / removal resistance and the connector blocking resistance are poor.

Further, Japanese Patent Application Laid-Open No. 1-159906 discloses a silver paste having excellent bending resistance using flake (flake) silver powder, a copolymerized polyester resin and a blocked isocyanate compound as a binder. . When cured sufficiently, good bending resistance is obtained, but resistance to connector insertion / removal and resistance to connector blocking are poor.

In Japanese Patent Application Laid-Open No. 9-306240, by combining a silver powder having a special shape with a binder having a high glass transition temperature, relatively good bending resistance, connector insertion / removal resistance and connector blocking resistance are obtained to some extent. It is known to be improved. However, since a binder having a high glass transition temperature is used, the MIT bending test is good, but the strict 360-degree bending test is not sufficient. Further, when a polyester resin having a low glass transition temperature of 10 ° C. or less is used as a binder, the connector insertion / removal resistance and the connector blocking resistance are insufficient. Also, 60 ° C
Even when the polyester having the above high glass transition temperature is used, it is insufficient for recent demands, that is, fine pitch connectors. Similarly, when a polyvinyl chloride-vinyl acetate copolymer having a high glass transition temperature is used as a binder, the connector insertion / removal resistance and the connector blocking resistance of a fine pitch connector are also insufficient.

Japanese Patent Application Laid-Open No. Hei 9-286968 proposes an evaporation-drying type conductive paste using a polyester resin obtained by copolymerizing polyalkylene glycol or polycaprolactone, which also has relatively good bending resistance. However, the resistance to connector insertion / removal and the resistance to connector blocking are poor.

As described above, according to the prior art, those having good bending resistance have poor connector insertion / removal resistance and connector blocking resistance, and are relatively good using a binder having a high glass transition temperature. Even a connector provided with excellent connector resistance is inadequate in recent fine-pitch connectors, and strong improvement is desired.

[0008]

Means for Solving the Problems As a result of intensive studies to solve such a problem, a conductive paste characterized by containing a conductive powder and a fibrous derivative as a binder is obtained.
It has been found that even at a fine pitch of 300 μm or less in terminal pitch, excellent connector insertion / removal resistance and connector blocking resistance are obtained, and furthermore, excellent bending resistance and high conductivity can be achieved, and the present invention has been reached. .
That is, the present invention is a conductive paste comprising a conductive powder (A), a fibrous derivative (B) having an average degree of polymerization of 100 or more as a binder, and another organic resin (C).

The conductive powder (A) used in the present invention preferably contains silver powder alone or silver powder in an amount of 60% by weight or more, particularly 70% by weight or more, and more preferably 80% by weight or more. Examples of the shape of the silver powder include known flakes (flakes), spheres, dendrites (dendrites),
There is a shape in which spherical primary particles are three-dimensionally aggregated as described in JP-A-306240. Among these, flake-like silver powder and the above-mentioned spherical primary particles are three-dimensional because of the conductive surface.
Silver powder having a dimensionally aggregated shape is preferred, but flake silver powder, which is generally used, is particularly preferred in terms of dispersibility and cost. As the conductive powder, in addition to silver powder, carbon-based fillers such as carbon black and graphite powder, precious metal powders such as gold powder, platinum powder and palladium powder, copper powder, nickel powder, aluminum powder,
Base metal powder such as brass powder, base metal powder plated and alloyed with noble metal such as silver, inorganic filler such as silica, talc, mica, barium sulfate, etc. can be mixed with silver powder and used, but conductivity, moisture resistance etc. Environmental characteristics and cost
20 carbon black and graphite powder in all conductive powder
It is preferred that the compounding be performed in an amount of up to 10% by weight, more preferably up to 10% by weight.

The amount of the conductive powder (A) used in the present invention is preferably such that the ratio of (A) / binder is 60/40 to 95/5 (weight ratio), more preferably 80/20 to 90/1.
0. (A) 60/4 in (A) / binder ratio
If it is less than 0, good electrical conductivity and bending resistance may not be obtained, and if it exceeds 95/5, the bending resistance, adhesion, and printability may decrease, which is not preferable.

It is necessary that the binder used in the present invention contains the cellulose derivative (B). By including this, the connector insertion / removal resistance and the connector blocking resistance at the time of fine pattern are greatly improved. Examples of the cellulose derivative (B) include cellulose acetate butyrate (CAB), cellulose acetate (CA), cellulose acetate propionate (CAP), ethyl cellulose, methyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl methyl cellulose, hydroxyethyl cellulose, and nitrification. Cotton (nitrocellulose) and the like. Of these, CAB, CA, CAP, and nitrified cotton having good solubility in general-purpose organic solvents are preferable. Nitrified cotton is J
It is preferable to use what is called industrial nitrocellulose according to IS K6703 and having a nitrogen content of about 10 to 13%. The average degree of polymerization of the fibrous derivative (B) is preferably 50 or more, more preferably 100 or more, from the viewpoint of bending resistance, and the higher the degree of polymerization, the better the connector insertion / extraction and connector blocking resistance. Is obtained.

The binder used in the present invention requires the use of another organic resin (C) in addition to the cellulose derivative (B). When the cellulose derivative (B) alone is used, the adhesion to the substrate becomes poor, and the bending resistance is also poor. The type of the other organic resin (C) to be blended is not limited, but the number average molecular weight is 3,
It is preferably at least 000, more preferably at least 8,000. When the number average molecular weight is less than 3,000, it is difficult to obtain good bending resistance, and the paste viscosity is undesirably reduced. Since the connector insertion / extraction resistance and the connector blocking resistance can be imparted by the cellulose derivative (B),
Other resins can be used even if the glass transition temperature is less than 25 ° C., and both good bending resistance and connector resistance can be achieved.
The more preferable glass transition temperature of the other organic resin (C) is 10 to -30C.

Other types of the organic resin (C) include:
Copolymerized polyester resin, polyester urethane resin,
Examples thereof include polyether urethane resin, polycarbonate urethane resin, vinyl chloride / vinyl acetate copolymer, epoxy resin, phenol resin, and acrylic resin.
When PET film is used as a substrate,
In terms of bending resistance and adhesion to the substrate, copolymerized polyester resin, polyester urethane resin, vinyl chloride
Vinyl acetate copolymers are particularly preferred. It is particularly preferable to mix a curing agent to form a thermosetting type from the viewpoint of bending resistance, connector blocking resistance, and insertion / extraction properties. The fibrin derivative (B) is effective even in a very small amount, but the preferred amount is at least 1% by weight, more preferably at least 3% by weight, and at most 30% by weight, more preferably Is at most 20% by weight. If the amount of the fibrin derivative (B) exceeds 30% by weight, the flex resistance and adhesion may decrease, which is not preferable.

When a polyurethane resin is used as the other organic resin (C), a resin synthesized by reacting a polyol and, if necessary, a chain extender with an isocyanate compound can be used by a known method. Polyols having a molecular weight of 500 or more used for the polyurethane resin include polyether polyols, (meth) acrylic polyols, polyester polyols, polycarbonate diols, and polybutadiene polyols. Diols or polyester carbonate diols are particularly preferred. As the polyol having a molecular weight of less than 500 used as a chain extender, neopentyl glycol,
6-hexanediol, ethylene glycol, HPN
(Hydroxypivalic acid ester of neopentyl glycol), trimethylolpropane, glycerin and the like are known. Further, a carboxyl group-containing polyol such as dimethylolpropionic acid can also be used as a chain extender.

Examples of the diisocyanate compound used in the polyurethane resin include tetramethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, and isophorone diisocyanate. The urethane group concentration of the polyurethane resin as the other organic resin (C) is from 500 to 4000 equivalent / 10 ⁶ from the viewpoint of adhesion and bending resistance.
g is preferred. The number average molecular weight is preferably from 8,000 to 40,000 from the viewpoint of bending resistance and paste viscosity.

When a copolyester resin is used as the other organic resin (C), a resin obtained by polycondensation under normal pressure or reduced pressure by a known method can be used. The copolymerized polyester is preferably a saturated polyester. After polymerization of the polyester resin, ε at 180 to 230 ° C.
-A cyclic ester such as caprolactone may be post-added (ring-opening addition) to block, or an acid anhydride such as trimellitic anhydride or phthalic anhydride may be post-added to impart an acid value. Dicarboxylic acids copolymerized with polyester include terephthalic acid, isophthalic acid, orthophthalic acid, aromatic dicarboxylic acids such as 2,6-naphthalenedicarboxylic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, dodecanedicarboxylic acid, azelaic acid Such as aliphatic dicarboxylic acids, dibasic acids having 12 to 28 carbon atoms, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 4-methylhexahydrophthalic anhydride, 3-methylhexahydrophthalic anhydride, 2-methylhexahydrophthalic anhydride, dicarboxy hydrogenated bisphenol A, dicarboxy hydrogenated bisphenol S, dimer acid, hydrogenated dimer acid, hydrogenated naphthalenedicarboxylic acid, tricyclodecanedicarboxylic acid Fats such as acids It is family dicarboxylic acid. Further, within the range not impairing the content of the invention, polyvalent carboxylic acids such as trimellitic anhydride and pyromellitic anhydride, unsaturated dicarboxylic acids such as fumaric acid, and 5
-A dicarboxylic acid containing a sulfonic acid metal base such as sulfoisophthalic acid sodium salt may be used in combination.

The alkylene glycol used for the polyester used as the other organic resin (C) includes ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, Pentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 2-methyl-1,5-pentanediol, 2,2-
Diethyl-1,3-propanediol, 2-butyl-2
-Ethyl-1,3-propanediol, 1,9-nonanediol, 1,10-decanediol, 1,4-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,2-cyclohexanedimethanol, dimer diol And the like. Polyhydric polyols such as trimethylolethane, trimethylolpropane, glycerin, pentaerythritol, and polyglycerin may be used in combination as long as the content of the invention is not impaired. Among these, from the viewpoint of durability, the acid component is preferably a combination of an aromatic dicarboxylic acid, an alicyclic dicarboxylic acid, and an aliphatic dicarboxylic acid having 10 or more carbon atoms, and the glycol component is neopentyl glycol, which has 5 to 10 carbon atoms. Long-chain aliphatic diols are particularly preferred.

As the vinyl chloride / vinyl acetate copolymer used as the other organic resin (C), known commercial products can be used. The content of vinyl chloride in the polymer is preferably 85 to 95%. Further, as a monomer other than vinyl chloride and vinyl acetate, a polar group may be introduced by copolymerizing a small amount of maleic acid, vinyl alcohol, or the like. When a carboxyl group is introduced with maleic acid, adhesion to a metal is improved, and when a hydroxyl group is introduced with vinyl alcohol, an isocyanate compound can be used as a curing agent.

As the other organic resin (C), a known epoxy resin or phenol resin may be used. From the viewpoint of bending resistance, these resins are not used alone, but are preferably used in combination with the above-described polyester resin, polyurethane resin, or the like. By mixing an appropriate amount of an epoxy resin or a phenol resin, the adhesiveness can be improved.

The binder of the present invention includes a cellulose derivative (B)
And / or a curing agent capable of reacting with another organic resin (C) may be blended. Although the kind of the curing agent is not limited, an isocyanate compound is particularly preferable from the viewpoint of adhesiveness, bending resistance, curability and the like. Further, it is preferable that these isocyanate compounds are used after being blocked, from the viewpoint of storage stability. As a curing agent other than the isocyanate compound, methylated melamine, butylated melamine, benzoguanamine,
Known compounds such as amino resins such as urea resins, acid anhydrides, imidazoles, epoxy resins and phenol resins are exemplified.

As the isocyanate compound, aromatic,
There are aliphatic diisocyanate and trivalent or higher polyisocyanate, and either low molecular weight compound or high molecular weight compound may be used. For example, tetramethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate or trimers of these isocyanate compounds, and excess of these isocyanate compounds Amount and, for example, ethylene glycol, propylene glycol, trimethylolpropane, glycerin, sorbitol, ethylenediamine, monoethanolamine, diethanolamine, low molecular active hydrogen compounds such as triethanolamine or various polyester polyols, polyether polyols, polyamides By reacting with a high molecular weight active hydrogen compound, etc. Terminal isocyanate group-containing compounds to be.

Examples of the blocked isocyanate agent include phenols such as phenol, thiophenol, methylthiophenol, ethylthiophenol, cresol, xylenol, resorcinol, nitrophenol and chlorophenol, and oximes such as acetoxime, methylethylketoxime and cyclohexanone oxime. Alcohols such as methanol, ethanol, propanol and butanol, ethylene chlorohydrin,
Halogen-substituted alcohols such as 1,3-dichloro-2-propanol, tertiary alcohols such as t-butanol and t-pentanol, ε-caprolactam, δ-valerolactam, γ-butyrolactam, β-propyrolactam And other active amines such as aromatic amines, imides, acetylacetone, acetoacetate, and malonic acid ethyl ester; mercaptans, imines, imidazoles, ureas, and diaryl compounds. And sodium bisulfite. Of these, oximes, imidazoles, and amines are particularly preferred over curability.

A known catalyst or accelerator selected according to the type of the crosslinking agent may be used in combination with these crosslinking agents.

The type of the solvent used in the present invention is not limited, and may be an ester type, a ketone type, an ether ester type,
Chlorine type, alcohol type, ether type, hydrocarbon type and the like can be mentioned. Among them, when screen printing is performed, a high boiling point solvent such as ethyl carbitol acetate, butyl cellosolve acetate, isophorone, cyclohexanone, and γ-butyrolactone is preferable.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments. In the examples, the term “parts” indicates parts by weight. Each measurement item followed the following method.

1. Reduced viscosity, ηsp / c (dl / g) The sample resin was phenol / tetrachloroethane (60
/ 40 weight ratio) It was dissolved in a mixed solvent at a concentration of 0.400 g / 100 ml and measured at 30 ° C. using an Ostwald viscometer.

2. Molecular weight The number average molecular weight in terms of polystyrene was measured by GPC.

3. Glass transition point temperature (Tg) Measured at a heating rate of 20 ° C./min using a differential scanning calorimeter (DSC). As a sample, 5 mg of the sample was placed in an aluminum holding lid type container and crimped.

4. Acid value 0.2 g of sample was precisely weighed and dissolved in 20 ml of chloroform. Then, it was determined by titration with 0.01 N potassium hydroxide (ethanol solution). A phenolphthalein solution was used as an indicator.

5. Preparation of test piece Conductive paste with 100 μm thickness annealed PET
A pattern having a line width of 150 μm, a pitch of 300 μm (line width of 150 μm, and a line interval of 150 μm) and a length of 75 mm (connector resistance against connector, connector blocking resistance, bending resistance test) so that the film thickness after drying becomes 8 to 10 μm. And a pattern (for measuring specific resistance) having a width of 25 mm and a length of 50 mm were screen-printed. Using a conveyor-type far-infrared oven, the surface temperature of the
What was dried at 0 ° C. for 3 minutes was used as a test piece.

6. Specific resistance5. Using the test piece prepared in the above section, the film thickness and the sheet resistance film thickness were measured using a 4-deep needle resistance measuring instrument, and the specific resistance was calculated from these.

7. 4. Flex resistance The test piece prepared in the above was weighed 50 g / cm ² , R
Under the condition of = 0, bending at 360 ° was repeated 5 times at the same location, and the resistance change rate of the conductor was evaluated. Flex resistance (%) = {(R−R ○) / R｝} × 100 where RＲ = initial circuit resistance R = resistance after flex test

8. Connector insertion / removal resistance A test piece prepared in 5 with a 125 μm reinforcing film adhered to the back surface was repeatedly inserted and removed 10 times using a fine pitch connector (300 μm pitch).
Evaluation was made based on the degree of peeling of the conductive paste coating film. ：: No peeling △: Slight peeling ×: Peeling

9. Connector blocking resistance A fine-pitch connector (300 μm pitch) was attached to a 125 μm reinforcing film adhered to the back surface of the test piece prepared in 5, and left at 60 ° C. and 95% RH for 500 hours. Then, the conductive paste coating film was extracted and evaluated by the degree of perforation. ○: No perforation △: Slightly perforated ×: Perforated

Synthesis Example 1 (Polyester resin I) 101 parts of dimethyl terephthalic acid, 35 parts of dimethyl isophthalic acid, 93 parts of ethylene glycol, neopentyl glycol 73
Parts, and 0.068 parts of tetrabutyl titanate, and 1
The S-exchange was performed at 80 ° C. for 3 hours. Then, 61 parts of sebacic acid was charged, and an esterification reaction was further performed. Next, the pressure was gradually reduced to 1 mmHg or less,
Polymerization was carried out at 1 ° C. for 1 hour. The composition of the obtained copolymerized polyester was terephthalic acid / isophthalic acid / sebacic acid // ethylene glycol / neopentyl glycol = 52/1.
Reduced viscosity 0.64 at 8/30 // 55/45 (molar ratio)
dl / g, number average molecular weight 22,000, acid value 1.5 mg
KOH / g, Tg = 7 ° C.

Synthesis Example 2 (Polyester resin II) Synthesis example. Compound 1 was synthesized in the same manner. The composition of the obtained copolyester was as follows: terephthalic acid / isophthalic acid / adipic acid // ethylene glycol / neopentyl glycol / 1,4-butanediol = 33/27/40 // 30
/ 36/46 (molar ratio), reduced viscosity 0.57 dl / g,
Number average molecular weight 20,000, acid value 15 mg KOH / g,
Tg = -7 ° C.

Preparation of Silver Powder A-1 275 parts of a 37% aqueous silver nitrate solution and 220 parts of an 18% aqueous sodium hydroxide solution were reacted with stirring at 40 to 50 ° C., and after the reaction was completed, 70 parts of distilled water was added. did. Then, 60 parts of a formalin aqueous solution having a concentration of 23% was added thereto and reacted at 30 to 40 ° C. PH after the reaction is 8
Met. The obtained silver powder was filtered, washed and dehydrated repeatedly, replaced with methanol, and filtered.
It dried under reduced pressure for 4 hours. The obtained silver powder had the shape shown in FIG. 1 and the average particle size of the primary particles was 0.5 μm from a scanning electron micrograph, and the average particle size of the secondary particles was 11 μm as measured by a light scattering method. , Specific surface area 1.62m ²
/ G.

Preparation of Silver Powder A-2 A commercially available flake silver powder (manufactured by Fukuda Metal Foil & Powder Co., Ltd.) was used as it was. Average particle size by light scattering method is 4.5μ
m, specific surface area was 0.7 m ² / g.

Embodiment 1 1 Silver powder A-2, 89 parts, 7.7 solids of polyester resin (I), cellulose acetate butyrate resin CAB-3
81-20 (Eastman Chemical Japan Co., Ltd.)
0.8 solid part, blocked isocyanate compound C-1
(Hexamethylene diisocyanate, methyl ethyl ketoxime block of isocyanurate adduct, solid content 80%) 2.5 solids, 0.5 parts of leveling agent, 0.04 parts of dibutyltin dilaurate as a curing catalyst are blended, and then sufficiently premixed Thereafter, the mixture was dispersed three times by a chilled three-roll kneader. Butyl carbitol acetate was used for dissolving each resin. The obtained silver paste had a low specific resistance of 6.5 × 10 ⁻⁵ Ω · cm, and the bending resistance was very good because the increase in resistance after 5 times of 360 ° bending was + 40%. Printability of fine pattern is 25μm thick width
Was good. In addition, despite the use of low Tg polyester as the main binder resin, the addition of CAB provides very good fine pitch connector insertion / removal resistance and connector blocking resistance. Compatibility with flexibility is possible.

Embodiment 1 In the same manner as in Example 1, the conductive pastes of Examples 2 to 5 were prepared and evaluated. Table 1 shows the results.

[0041]

[Table 1]

1) Conductive carbon black (manufactured by Lion Akzo Co., Ltd.) 2) Cellulose acetate butyrate resin (manufactured by Eastman Chemical Japan Co., Ltd.) 3) Cellulose acetate propionate resin (Eastman Chemical Japan Co., Ltd.) 4) Cellulose acetate (manufactured by Eastman Chemical Japan Co., Ltd.) 5) Nitrified cotton (manufactured by Asahi Kasei Kogyo Co., Ltd.) 6) Nitrified cotton (manufactured by Asahi Kasei Kogyo Co., Ltd.) 7) Vinyl chloride copolymerized with phenyl alcohol -Vinyl acetate copolymer (manufactured by Union Carbide Co., Ltd.) 8) Polyester urethane resin (manufactured by Toyobo Co., Ltd.) in which the solvent is replaced with ethyl acetate 9) Blocked isocyanate compound (hexamethylene diisocyanate, isocyanurate) Adduct methyl ethyl ketoxime bromide Click member) 10) blocked isocyanate compounds (hexamethylene diisocyanate, biuret trimer methyl ethyl ketoxime block body)

Embodiment 1 In the same manner as in Example 1, the conductive pastes of Comparative Examples 1 to 5 were prepared and evaluated. Table 2 shows the results. It can be seen that when no cellulose derivative is blended, the connector blocking resistance is particularly poor.

[0044]

[Table 2]

1) Polyester urethane resin (manufactured by Toyobo Co., Ltd.) in which the solvent is replaced with ethyl carbitol acetate

[0046]

The conductive paste of the present invention, which contains a fibrous derivative as a binder, can achieve both high bending resistance, fine-pitch connector insertion / removal resistance and blocking resistance, and solve the problems of the prior art. Can be overcome.
As a result, the density and size of the product can be further increased, and the defect rate can be reduced.

[Brief description of the drawings]

FIG. 1 is a scanning atomic microscope photograph of silver powder A-1 used in Examples of the present application.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 75/06 C08L 75/06 H01B 1/22 H01B 1/22 A F term (Reference) 4J002 AB022 AB032 BD041 BD081 CF001 CK021 DA076 FD116 GQ05 HA08 5G301 DA03 DA18 DA42 DA46 DA53 DA59 DD01

Claims (2)

[Claims] 1. A conductive paste comprising a conductive powder (A), a cellulose derivative (B) and another organic resin (C) as a binder. 2. The conductive paste according to claim 1, wherein the other organic resin (C) contains at least one selected from a polyester resin, a polyester urethane resin, and a vinyl chloride copolymer.