JPH01203470A - Electrically conductive composition - Google Patents

Abstract

PURPOSE:To obtain the present composition outstanding in storage stability and resistance to environment, by blending an electrically conductive coating component made up of copper powder, resin binder and solvent with a mixture, as the dispersant, of titanium acylate polymer and higher saturated fatty acid ester. CONSTITUTION:The objective electrically conductive composition comprising (A) copper powder, (B) a resin binder (e.g., acrylic resin, polyester resin), (C) a mixture of C1: 20-80wt.% of a titanium acylate polymer, i.e., a condensate of at least dimer having recurring unit(s) of formula I, II and/or III (R' is 1-10C hydrocarbon group; R<1>-R<3> are each 1-17C hydrocarbon group; l>1, m>1, n>=1) and C2: 80-20wt.% of a higher saturated fatty acid ester, pref. a compound of formula IV (R is 1-17C hydrocarbon group; R<1> is 1-10C hydrocarbon group) (D) a solvent in such amounts as to be, based on the weight of the final composition except the component D, 40-90wt.%, 10-60wt.% and 0.05-10wt.% for the components A, B and C, respectively, with the component A covered with 0.1-10wt.% of the component C (based on the component A).

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a conductive paint, and more specifically, the present invention relates to a conductive paint, and more specifically, a conductive paint that can be coated without reducing the conductivity and electromagnetic shielding effect of copper powder.
The present invention relates to a conductive composition that improves the storage stability and environmental resistance of a paint, as well as the conductivity, aging resistance, and adhesion of a coating film to a substrate.

[Prior Art] Conventionally, conductive fillers such as nickel powder, silver powder, copper powder, and carbon powder are mixed with various binder resins as one of the electromagnetic shielding materials that protect electronic devices from electromagnetic interference. There are paints that can be applied to the surface of plastic molded products by spraying or brushing to shield them from electromagnetic waves. Among various conductive paints, copper-based conductive paints are cheaper than paints using silver powder or nickel powder, and have excellent shielding effects.

However, copper-based conductive paints have poor storage stability because the copper powder aggregates in the paint, making it difficult to obtain a good dispersion state. Furthermore, they are easily oxidized in environments such as heat and humidity, and therefore have poor environmental resistance. Also, there is a problem that conductivity is easily deteriorated (shielding effect is attenuated). Various proposals have been made in the past to solve this problem. For example, conductive paints are manufactured by blending copper powder with a binder resin and organic titanate (Japanese Patent Laid-Open No. 56-36553), and surface treatment of copper powder with a coupling agent (Japanese Patent Laid-Open No. 60-30
No. 200), coating electrolytic copper powder with organic titanate (Japanese Unexamined Patent Publication No. 59-174661), and coating copper powder with organic aluminum (Japanese Unexamined Patent Publication No. 59-17967).
Publication No. 1) etc. have been proposed.

These conductive paints can improve storage stability and environmental resistance to some extent without reducing the conductivity and electromagnetic shielding effect of copper powder.

[Problem 8 to be solved by the invention] However, when conventional conductive paints are applied to a base material and used, they have poor adhesion to the base material, and they do not necessarily have excellent storage stability and environmental resistance. does not indicate gender.

This invention was made based on the above-mentioned background, and its purpose is to eliminate the drawbacks of the conventional conductive paint mentioned above, and to reduce the conductivity and electromagnetic shielding effect of the coating film made of copper powder. An object of the present invention is to provide a conductive composition that can improve the storage stability and environmental resistance of a paint, as well as the adhesion of a paint film, without causing problems.

[Means for Solving the Problems] The present inventors have conducted various tests and studies on conductive paints, and have found that if a mixture of titanium acylate polymer and higher saturated fatty acid ester is used as a dispersant in a composition, this can be achieved. This invention was found to be effective in achieving the purpose of the invention, and the invention was completed.

That is, the conductive composition of the present invention is made by adding a mixture of a titanium acylate polymer and a higher saturated fatty acid ester as a dispersant to conductive paint components of copper powder, a resin binder, and a solvent. It is.

This invention will be explained in more detail below.

Copper powder The shape of the copper powder used in this invention can be obtained by electrolytic method, reduction method,
There are dendritic, granular, and spherical shapes obtained by the atomization method.
Furthermore, there are flakes obtained by mechanically processing these materials using a ball mill or the like.

The dendritic copper powder obtained by the electrolytic method used in this invention is 0.50 to 2. Apparent density of OOg/cat, 1.00
It is preferable to have a specific surface area of less than 100 μm, a particle size distribution of less than 100 μm, and an average particle size of 3 to 30 μm. This means that the apparent density is less than 0.50 g/cd or 2.0 μm.
If the specific surface area exceeds 1.00 rrr/g, the oxidation resistance will be markedly poor, and if the particle size distribution exceeds 100 μm, the paint will be difficult to apply due to coarse particles. This is because the coating workability deteriorates, a uniform coating film cannot be obtained, and the nozzle tip becomes clogged when the coating material is sprayed. In the case of granular or spherical copper powder obtained by reduction method or atomization method, 2,
OO~5. 0 Og/cir tap density, 1.00
rr? /g or less specific surface area, 0.3-50. It is preferable to have a particle size distribution of czm and an average particle size of 0.5 to 15 μm.

In order to improve contact between copper powders or the degree of filling of copper powder, copper powders having different shapes may be mixed to improve conductivity.

For example, flaky copper powder, granular copper powder, and spherical steel powder can be mixed with dendritic copper powder using a V-type mixer or the like. In this case, it is better to increase the content of dendritic copper powder.

Copper powder that can be used in this invention includes metal,
There are coated copper powders coated with alloys, organic surface treatment agents, etc., which can prevent oxidation of the copper powder surface. Such surface treatment agents include metals such as silver, nickel, zinc, platinum, and palladium, alloys such as solder, metal organic compounds such as silicon, titanium, and aluminum, surfactants, amino acids, various amines, carboxylic acids, and There are organic compounds such as its derivatives. The amount of these coatings on the copper powder is a part or the entire surface area of the copper powder.

Further, inorganic or organic processing agents or lubricants used in the copper powder manufacturing process may be attached to the raw copper powder.

In this invention, the preferred coated copper powder is copper powder coated with a mixture of titanium acylate polymer and higher saturated fatty acid ester. The coating amount of the mixture of titanium acylate polymer and higher saturated fatty acid ester on the copper powder is 0.01 to 15% by weight, preferably 0.0% by weight.
It is 5 to 10% by weight. If the amount is less than 0.05% by weight, the copper powder tends to aggregate with each other, and the conductivity, heat resistance, and moisture aging resistance of the coating film begin to deteriorate, and if it is less than 0.01% by weight, this tendency becomes significant. In addition, if the amount exceeds 10% by weight, a hydrophobic film of excessive titanium acylate polymer and higher saturated fatty acid ester is formed on the surface of the copper powder, which prevents sufficient contact between the copper powders and deteriorates the conductivity and heat resistance of the coating film.
This is because the moisture aging resistance begins to deteriorate, and this tendency becomes remarkable when the content exceeds 15% by weight.

If necessary, the oxidized coating from the surface of the copper powder can be removed by using reagents such as inorganic acids, organic acids, various reducing agents, or by ammonia or hydrogen gas reduction as pretreatment. The copper powder can be dried as a pretreatment.

The content of copper powder in the conductive composition can be changed as appropriate depending on the use of the composition, desired characteristics, etc., but for example, the content of copper powder is 40 to 90% based on the weight of the conductive composition excluding the solvent.
% by weight, preferably 50 to 80% by weight. This is because if the copper powder is less than 50% by weight, sufficient contact between the copper powders will not be achieved, and the conductivity and heat and humidity resistance of the coating film will begin to deteriorate, and if it is less than 40% by weight, this tendency will become significant. In addition, when the content exceeds 80% by weight, the content of the resin binder decreases, and the shrinkage rate of the resin binder decreases accordingly, and the conductivity, heat resistance, and moisture aging resistance of the coating film begin to decrease, and when the content exceeds 90% by weight. This is because this tendency becomes remarkable and it becomes difficult to form a coating film.

Resin Binder The resin binder that can be used in the present invention preferably consists of a resin that exhibits good adhesion to plastics used in common electronic devices. Examples of such resins include thermoplastic resins such as acrylic resins, polyester resins, styrene resins, and urethane resins, and thermosetting resins such as phenolic resins.

The content of the resin binder in the conductive composition can be changed as appropriate depending on the use of the composition, desired properties, etc., but for example, based on the weight of the conductive composition excluding the solvent,
10 to 60% by weight, preferably 20 to 50% by weight
It is. This is because when the content is less than 20% by weight, the content of the resin binder decreases, and the shrinkage rate of the resin binder decreases accordingly, and the conductivity, heat resistance, and moisture aging resistance of the coating film begin to decrease. This tendency becomes remarkable and it becomes difficult to form a coating film.On the other hand, as the content of the resin binder exceeding 50% by weight increases, the contact rate between copper powders begins to decrease, resulting in a decrease in electrical conductivity, heat resistance, and moisture resistance of the coating film. This is because the aging properties begin to deteriorate, and this tendency becomes remarkable when the content exceeds 60% by weight.

Titanium acylate polymer One of the components coated on the copper powder is titanium acylate polymer. Specifically, the titanium acylate polymer is a condensation product of a dimer or more containing the following repeating units Ln and/or III.

0COR'OR' (In the formula, R' is a hydrocarbon group having 1 to 10 carbon atoms, 0CO
R1, R2 and R3 of 0COR2 and 0COR3 are the same or different hydrocarbon groups having 1 to 17 carbon atoms, ■ and m satisfy l>1 and m>1, respectively, and n satisfies n≧1. In addition to the above, the titanium acylate polymer used in this invention is also specified as follows, and falls under any of these definitions.

That is, the titanium acylate polymer has a main chain → -Ti
It has an easily hydrolyzable alkoxy group bonded to the titanium atom of -0← and a hardly hydrolyzable and lipophilic acylate group also bonded to the titanium atom, and has an easily hydrolyzable alkoxy group at the end. or the titanium acylate polymer has easily hydrolyzable end groups as shown below.

-OR' and/or -R' In this formula, OR' is a hydrocarbon group R having 1 to 10 carbon atoms.
', R' is a hydrogen atom, R
SR', 0COR1, 0COR2 or 0COR3.

This titanium acylate polymer is produced by reacting carboxylic acid, acid anhydride, inorganic acid, etc. with tetraalkoxytitanium T i (OR) 4, and also with tetrachlorotitanium T i
It can be obtained by reacting (Cl)4 with ammonia/carboxylic acid, carboxylic acid sodium salt, etc.

A preferred method for synthesizing a titanium acylate polymer is a method in which tetraalkoxytitanium T i (OR) 4 is reacted with several times the molar amount of carboxylic acid, particularly higher saturated fatty acid. This is due to the following reasons. Firstly, it is possible to suppress the formation of monoacylate compounds and titanium acylate polymers and quantitatively obtain titanium acylate polymers, secondly, no chlorides or inorganic acids are produced as reaction by-products, and thirdly, By using a higher saturated fatty acid, the side chains of the titanium acylate polymer are acylated by the higher saturated fatty acid, making the titanium acylate polymer film more hydrophobic and enhancing the dispersion effect, and furthermore, the obtained reaction mixture can be used in this invention. This is because it can be used as a raw material for coating copper powder and adding it to a composition.

A method for preparing tetraalkoxytitanium T i (OR) 4 from several times the molar amount of carboxylic acid or an isomer includes, for example, adding 1 mol or more, preferably 3 to 6 mol, of stearic acid to 1 mol of tetraisopropyl titanium. , higher saturated fatty acids such as valmitic acid, mystilic acid, lauric acid, and capric acid and their isomers.

Separation and purification of the synthesized titanium acylate polymer can be performed by methods such as distillation, extraction, recrystallization, and column chromatography.

Higher saturated fatty acid ester The higher saturated fatty acid ester in this invention has a large number of carbon atoms, and preferred esters include those represented by the following general formula.

RCOOR' (wherein, R is a hydrocarbon group having 1 to 17 carbon atoms, and R' is a hydrocarbon group having 1 to 10 carbon atoms). Specific examples of such carboxylic acid esters include stearic acid ester, These include higher saturated fatty acids such as palmitic acid esters, mystylic acid esters, lauric acid esters, and capric acid esters, and their isomers. This is because if the carboxylic acid ester used is low grade, the hydrophobicity of the carboxylic acid film formed on the surface of the copper powder will be impaired, and the good dispersion state of the copper powder will not be achieved in the formation of paints and coatings with the binder resin. Because you can't get it.

Separation and purification of the synthesized carboxylic acid ester can be performed by methods such as distillation, extraction, recrystallization, and column chromatography.

Manufacture of conductive composition The conductive composition according to the present invention is produced by combining copper powder as a composition raw material, a resin binder, a mixture of a titanium acylate polymer as a dispersant and a higher saturated fatty acid ester, and a solvent simultaneously or sequentially. It can be carried out by adding and mixing.

The mixture of titanium acylate polymer and higher saturated fatty acid ester added as a dispersant can be obtained by mixing predetermined amounts of titanium acylate polymer and higher saturated fatty acid ester, and also by mixing predetermined amounts of titanium acylate polymer and higher saturated fatty acid ester. can be obtained from a reaction mixture with

The mixing ratio of titanium acylate polymer and higher saturated fatty acid ester in this mixture is 5
~95@Higher saturated fatty acid ester 95-5 for child%
m; %, preferably titanium acylate polymer 20-8
Higher saturated fatty acid ester 80-20% by weight, more preferably titanium acylate polymer 40-20% by weight relative to 0% by weight
Higher saturated fatty acid ester 60-40% by weight
Weight%. This is because titanium acylate polymer has 4
If it is less than 0% by weight, the hydrophobicity of the surface of the copper powder will be insufficient, and the heat resistance and moisture aging resistance of paints and coatings will gradually begin to deteriorate.If it is less than 5% by weight, this tendency will be remarkable, and titanium acylate This is because when the polymer content exceeds 80% by weight, the conductivity of the copper powder in paints and coatings begins to gradually decrease, and when the content exceeds 95% by weight, this tendency becomes remarkable.

The mixture of titanium acylate polymer and higher saturated fatty acid ester can be diluted with, for example, an organic solvent. Organic solvents that can be used here include preferably nonpolar solvents such as toluene and hexane, as well as polar solvents such as alcohol and acetone.

When a mixture of titanium acylate polymer and higher saturated fatty acid ester is obtained from a reaction mixture of tetraalkoxytitanium and higher saturated fatty acid, 1 mole of tetraalkoxytitanium and 2 to 6 moles of higher saturated fatty acid, preferably 1 mole of tetraalkoxytitanium. and higher saturated fatty acid in a ratio of 3 to 4 moles. If it is less than this range, it will become an acylate, such as a monoacylate,
This is because titanium alkoxy polymer is produced and titanium acylate polymer is not produced, and if the amount exceeds this range, titanium acylate polymer can be obtained quantitatively, but by-products such as carboxylic acid ester and alcohol will increase excessively. . The alkoxy group of the tetraalkoxytitanium used here has 1 to 15 carbon atoms, preferably 1 to 10 carbon atoms. This is because when the number of carbon atoms exceeds 10, the hydrolysis reaction with water adsorbed on the surface of the copper powder does not proceed quickly, and the reactivity of forming acylate with carboxylic acid decreases, and when the number of carbon atoms exceeds 15, the reactivity becomes significant. This is because the reaction rate will decrease and the reaction will hardly proceed.

The total content of the mixture of titanium acylate polymer and higher saturated fatty acid ester in the conductive composition is 0.01 to 15% by weight, preferably 0.05 to 15% by weight, based on the weight of the conductive composition excluding the solvent. It is 10%. If it is less than 0.05% by weight, it is not possible to obtain a good dispersion state of copper powder in paints and coatings, and it is difficult to obtain good dispersion of copper powder in paints and coatings.
Moisture aging resistance begins to deteriorate, and if it is less than 0.01% by weight, this tendency becomes noticeable. On the other hand, if it exceeds 10% by weight, contact between the copper powders is hindered, and if it exceeds 15% by weight, this tendency becomes noticeable.

When producing a conductive composition, a mixture of titanium acylate polymer and higher saturated fatty acid ester can be added to raw materials such as copper powder, for example, by adding it directly little by little, or by diluting it with an organic solvent, water, etc. Add. It is desirable to appropriately select operational parameters such as addition rate and post-addition stirring time.

The solvent that can be used in this invention is preferably an organic solvent that dissolves additives such as a resin binder and a dispersant and has low reactivity.

Examples of such substances include hydrocarbons such as toluene, hexane, and xylene, ketones such as methyl ethyl ketone and methyl isobutyl ketone, alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol, and butyl alcohol, and ethyl acetate and butyl acetate. There are ethers such as esters, methyl cellosolve, and ethyl cellosolve. These can be used singly or in combination of two or more in consideration of workability and the like.

In addition to the above components, various additives can be included depending on the purpose. Such agents include reducing agents, surfactants, antisettling agents, antifoaming agents, thickeners, thixotropic agents, rust preventives, flame retardants, and the like.

[Function] In this invention and preferred embodiments having the above configuration,
It works as follows.

When a titanium acylate polymer and a higher saturated fatty acid ester are added to a dispersion system of copper powder, a resin binder, and a solvent, a portion of the titanium acylate polymer covers the surface of the copper powder, and the rest is mixed into the dispersion system. The titanium acylate polymer covering the surface of the copper powder mainly contributes to the formation of a hydrophobic film on the surface of the copper powder. That is, the alkoxy group, which is a hydrolyzable group at the end of the titanium acylate polymer, reacts with adsorbed water on the surface of the copper powder or the coating, and forms a hydrophobic film of the titanium acylate polymer with the hydrophobic portion facing outside. Since titanium acylate polymer is a macromolecule, it cannot form a complete hydrophobic film, and gaps are created in the film. However, like the titanium acylate polymer, the added higher saturated fatty acid ester reacts with the adsorbed water on the surface of the copper powder or the coating, and forms a higher saturated fatty acid acylate hydrophobic film with the hydrophobic portion on the outside.

Therefore, the higher saturated fatty acid ester forms a dense hydrophobic film on the surface of the copper powder in combination with the titanium acylate polymer. Furthermore, the titanium ester polymer and the higher saturated fatty acid ester contribute to the dispersibility of the copper powder. In other words, the long-chain titanium acylate polymer side chain moiety and the hydrophobic moiety of the higher saturated fatty acid ester are skillfully bonded to binder resin molecules in paints and coatings through van der Waals forces, hydrogen bonds, ionic bonds, covalent bonds, etc. The shear stress generated during the mixing, stirring, and kneading processes forms a good dispersion state of the copper powder in the paint and coating film, eliminates the unevenness of the copper powder, further improves the storage stability of the paint, and improves the storage stability of the paint. Significantly improves adhesion to

Furthermore, the higher saturated fatty acid ester and titanium acylate polymer remaining in the dispersion system exist around the copper powder flowing and dispersing in the dispersion system, preventing the copper powders from aggregating with each other and preventing deterioration over time. control and further improve the storage stability of paints.

[Effect of the invention] The conductive composition of the present invention provides the following effects.

(1) In the conductive composition of claim 1, a mixture of a higher saturated fatty acid ester and a titanium acylate polymer is added as a dispersant, so a part of it covers the surface of the copper powder and the rest covers the dispersion. The titanium acylate polymer and higher saturated fatty acid ester mixed into the system and covering the surface of the copper powder contribute to the formation of a complete and dense hydrophobic film on the surface of the copper powder.
Therefore, the present invention prevents the oxidation of copper powder in paints and coating films, and exhibits aging resistance superior to the effect of conventional monomolecular films of organic substances, particularly organic titanate compounds.

On the other hand, the higher saturated fatty acid ester and titanium acylate polymer remaining in the dispersion system exist around the copper powder flowing and dispersing in the dispersion system, preventing the copper powders from aggregating with each other and preventing deterioration over time. and improves the storage stability and aging resistance of paints.

(2) In the conductive composition of claim 2, since the raw copper powder is coated with a mixture of titanium acylate polymer and higher saturated fatty acid ester, a complete and dense hydrophobic film is more reliably formed on the surface of the copper powder. Therefore, conductivity, aging resistance, and tightness with the base material can be further improved.

(3) In the conductive composition of claim 3, since the coating amount of the mixture of titanium acylate polymer and higher saturated fatty acid ester is set to 0.05% to 10% by weight, the copper powder is No agglomeration occurs, and no hydrophobic film of excessive titanium acylate polymer and higher saturated fatty acid ester is formed on the surface of the copper powder. It is possible to improve and maintain the conductivity, heat resistance, moisture resistance, and aging characteristics of the coating film.

(4) In the conductive composition of claim 5, the content of copper powder in the conductive composition is 40 to 90% by weight, so
Copper powders can come into sufficient contact with each other, and the content of the resin binder can be adjusted to an appropriate level, improving the conductivity and heat-resistant, moisture-resistant, and aging properties of the coating film.

Further, the content of the resin binder in the conductive composition is 10
Since it is 60% by weight, the shrinkage rate of the resin binder can be maintained, the contact rate between copper powders does not decrease, and the conductivity and heat-resistant, moisture-resistant, and aging characteristics of the coating film can be maintained favorably.

(5) In the conductive composition of claim 8, since the total content of the mixture of titanium acylate polymer and higher saturated fatty acid ester is 0.05 to 10% by weight, It is possible to maintain the copper powder in a well-dispersed state and maintain contact between the copper powders, thereby improving conductivity, heat resistance, and moisture aging resistance.

(6) In the conductive composition of claim 9, the mixing ratio of the titanium acylate polymer and the higher saturated fatty acid ester is 80 to 20% by weight of the higher saturated fatty acid ester to 20 to 80% by weight of the titanium acylate polymer. Therefore, the surface of the copper powder has sufficient hydrophobicity, the dispersibility of the copper powder in the paint and the coating film is maintained, and the heat resistance and moisture aging resistance of the paint and the coating film are improved.

[Example] The invention will be illustrated by the following example.

Experimental material a, titanium acylate polymer The titanium acylate polymer used in this experiment was prepared by mixing 1 mole of tetraisopropyl titanium and the higher saturated fatty acids shown in Table 1 in the same proportions and reacting them. .

Table 1 Titanium acylate polymer No. Higher saturated fatty acid mole number 1-
1 Isostearic acid 31-2
Valmitic acid 51-3 Mystylic acid 31-4 Lauric acid
61-5 Capric acid 3
b. Higher saturated fatty acid ester Higher saturated fatty acid esters 2-1 to 2-5 used in this experiment were prepared by reacting isopropyl alcohol and higher saturated fatty acids shown in Table 2.

Table 2 Higher saturated fatty acid ester No. Higher saturated fatty acid 2-1
Isostearic acid 2-2 Valmitic acid 2-3 Mystiric acid 2-4 Lauric acid 2-5 Capric acid C1 Organotitanate compounds For comparison, the organotitanate compounds in Table 3 below were used.

Table 3 Organic titanate compound no.

3-1...Isopropyl tridodecylbenzenesulfonyl titanate 3-2...Isopropyl tris(dioctylpyrophosphate) titanate 3-3...Bis(dioctylpyrophosphate)oxyacetate titanate 3-4...Tetraisopropylbis (Dioctyl phosphate) titanate 3-5... Isopropyl tricumylphenyl titanate 3-6... Isopropyl tri(dioctyl phosphate) titanate 3-7... Bis(dioctyl pyrophosphate) ethylene titanate d, lower fatty acid ester comparison For this purpose, the fatty acid esters listed in Table 4 below were used.

Table 4 Fatty acid ester No.

4-1... Isopropyl isoacetate 4-2.
... Isopropyl valerate 4-3...
Isopropyl caproate 4-4... Isopropyl propionate e, copper powder Dendritic electrolytic copper powder shown in Table 5 (manufactured by Mitsui Mining & Smelting Co., Ltd., MF-D2) was used.

Table 5 Apparent Density 0.8-1. 1g/cm3 Specific surface area 0.40g/g Purity 99.2% or more HNO3 insoluble content Less than 0.03% Reduction reduction less than o, so% Average particle size
8.0 μm f, mixture of titanium acylate polymer and higher saturated fatty acid ester (present invention) The titanium acylate polymer shown in Table 1 and the higher saturated fatty acid ester shown in Table 2 are combined in the combination and composition shown in Table 6. A mixture according to the invention was prepared.

Table 6 No. Titanium reed High saturated fat rate polymer Acid ester 6-1 1-1 50vt% 2-150vt%6-
2 1-2 50vt% 2-250vt%6-3
1-3 50vt% 2-350vt%6-4 1-
4 50vt% 2-450vt%6-5 1-5
50wt% 2-550wt%6-6 1-1 40
vt% 2-560vt%6-7 1-2 70wt
% 2-430vt%6-8 1-3 40wt%
2-160vt%6-9 1-4 70wt% 2
-230vt%6-10 1-5 40wt% 2-
160vt%6-11 1-1 60wt% 2-4
40vt%6-12 1-2 40vt% 2-16
0wt%6-H1-360vt% 2-2-24O
%6-14 1-4 40vt% 2-560v
t%6-15 1-5 60sit% 2-2
40wt%6-16 1-6 51wt%2
-649vL% For the combination of 1-6 and 2-6 in No. 6-6, a reaction mixture of 1 mol of tetraisopropyl titanium and 3 mol of isostearic acid was used as it was. The titanium acylate polymer was identified by extracting the reaction mixture with acetone and analyzing the acetone-insoluble portion by liquid chromatography, IR spectrum, NMR spectrum, mass spectrum, and elemental analysis, and confirmed that it was a titanium acylate polymer. was confirmed.

g. Mixture of organic metal compound and fatty acid ester for comparison A mixture for this comparison was prepared using the combination and composition shown in Table 7 of the organic titanate compound of Table 3 and the fatty acid ester of Table 4. .

Table 7 No. Metal organic compound fatty acid ester 7-
1 3-1 50νt% 4-150wt%7-2
3-2 50wt% 4-2 50wt%7-3 3
-3 50vt% 4-3 50sit%7-4 3-
4 50vt% 4-450vt%7-5 3-5
50vt% 4-150vt%7-6 3-6 50
vt% 4-2 50vt%7-7 3-7 50v
t% 4-350vt%h, mixtures of metal organic compounds and fatty acid esters for comparison, combinations of titanium acylate polymers in Table 1 and fatty acid esters in Table 4, and combinations of organic titanate compounds in Table 3 and fatty acid esters. Combinations with the higher saturated fatty acid esters shown in Table 2 and mixtures for comparison shown in Table 8 with compositions were prepared.

Table 8 No. Metal H compound Fatty acid ester 8-
1 1-1 50νt% 4-150wt%8-2
1-2 50vt% 4-2 50sit%8-3 3
-1 50wt% 2-150vt%8-4 3-2
50wt% 2 2 50wt% Experimental example 1 Rust prevention effect The copper powder shown in Table 5 was stirred and dispersed in a toluene solvent, and the mixture shown in Table 6 was added little by little into the copper powder dispersion bath to remove copper. Processed powder. After drying the copper powder, it was left to stand for 1350 hours in a high humidity environment of 85° C. and 60° C./95% RH, and was tested for heat resistance and humidity resistance. In addition, the processing amount of the mixture is 0.05.0.1.0.5.1.0.3.
It was 0.5.0.10.0.10.5@% by weight.

As a result, it was found that copper powder according to a preferred embodiment of the present invention treated with Mixture Nos. 6-1 to 16 in a treatment amount of 0.1 to 10.5% by weight had no discoloration and no patina. Ta.

Comparative Experiment Example 2 Antirust Effect The copper powder shown in Table 5 was stirred and dispersed in a toluene solvent, and the mixture shown in Tables 7 and 8 was added little by little into the copper powder dispersion bath to obtain copper powder. processed.

After drying the copper powder, the temperature of 85℃, 60℃/95%
Heat resistance and humidity resistance tests were conducted by leaving the product for 1350 hours in a RH high humidity environment. In addition, the processing amount of the mixture is 0.05, respectively.
．． 0,1.0.5.1.0.3.0.5.0.10.0
．． It was 10.5% by weight.

As a result, the copper powders treated with Mixture Nos. 7-1 to 7 and 8-3 to 4 exhibited significant discoloration and patina. In addition, the copper powders treated with Mixtures No. 8-1 and 8-2 had no discoloration at all and did not develop verdigris.

From the results of Experimental Examples 1 and 2, the steel powder according to the present invention has the following properties:
It was found that it has an excellent rust prevention effect.

Experimental Example 3 Volume resistivity and aging resistance 45% by weight methacrylic resin solution (acrylic bond B) based on copper powder
C-415B manufactured by Mitsubishi Rayon), the copper powder in Table 5, the mixture in Table 6 for the solid content of methacrylic resin, respectively,
0,05.0°1.0.5.1.0.3.0.5.0.
10.0.10.5% by weight and a solvent (toluene) were stirred to prepare a conductive paint. The obtained conductive paint was used to form a circuit on an acrylic board using a screen printing machine, and then heated at 25°C.
After being left in the atmosphere for 24 hours, the volume resistivity of this circuit was measured.

The circuit obtained from the conductive paint according to this invention is 5X10
It had a volume resistivity of ˜8×10′Ω.

After the same conductive paint was left in an environment of 20-b RH for 3 months, a circuit was formed by the same operation, and the volume resistivity of the circuit was measured.

The circuit obtained from the conductive paint according to this invention is 5X10
It had a volume resistivity of ˜8×10 −4 Ω.

Experimental Example 4 Volume Resistivity and Aging Resistance For copper powder, methacrylic resin solution (acrylic bond BC-415B manufactured by Mitsubishi Rayon) with a weight of 45 and 96, copper powder shown in Table 5,
0.05.0.1.0 for each of the mixtures in Tables 7 and 8 based on the solid content of methacrylic resin. 5.1.0,
3.0°5.0.10.0.10.5% by weight and a solvent (toluene) were stirred to prepare a conductive paint. A circuit was formed on an acrylic plate using the obtained conductive paint using a screen printing machine, and the circuit was left in the atmosphere at 25° C. for 24 hours, and then the volume resistivity of this circuit was measured.

As a result, the circuit obtained from the comparative conductive paint was 2×1
It had a volume resistivity of 0 to 5×10 −3 Ω·(1).

After the same conductive paint was left in an environment of 20-bRH for 3 months, an attempt was made to measure the volume resistivity of the circuit.

As a result, the separation of the copper powder, resin binder, and solvent was severe, and the copper powder solidified, making it impossible to form it into a paint.

From the results of Experimental Examples 3 and 4, it was found that the conductive paint of the present invention has excellent dispersibility, good electrical conductivity, and good aging resistance.

Experimental Example 5 Heat resistance, humidity resistance, and aging resistance of coating film A conductor circuit was formed on an acrylic board in the same manner as in Experimental Example 3, and the resistance was determined after being left for 1350 hours in a heat resistance test at 85°C and a humidity resistance test at 60°C/95% RH. The rate of change (%) was measured.

As a result, in a heat resistance test at 85°C, most of the circuits obtained from the conductive paint according to the present invention showed a resistance of around 10%.
It showed a resistance change rate of at least 5% and at most 20%. In the humidity test at 60° C./95% RH, most of the samples showed a resistance change rate of around 5%, at least 15%, and at most 10%.

Comparative Experiment Example 6 Heat resistance, moisture resistance, and aging properties of coating film A conductive circuit was formed on an acrylic board in the same manner as in Comparative Experiment Example 4, and 85
℃ heat resistance test, 60℃/95%RH humidity test, 13
The resistance change rate (%) was measured after being left for 50 hours.

As a result, in the heat resistance test at 85° C., most of the circuits obtained from the comparative conductive paint showed a resistance change rate of 70 to 100%, and many showed a resistance change rate of 150% or more. In the humidity test at 60° C./95% RH, most of the samples showed a resistance change rate of 50 to 70%, and many showed a resistance change rate of 100% or more.

From the results of Experimental Example 5 and Comparative Experimental Example 6 above, it was found that the coating film obtained from the conductive paint of the present invention had good heat resistance and moisture aging resistance.

Experimental Example 7 Salt Water Spray Test on Paint Film A conductor circuit was formed on an acrylic board in the same manner as in Experiment 3, and a salt water spray test was conducted. The salt spray test was based on the JIS standard, using an aqueous solution with a salt water concentration of 5% by weight (liquid temperature: 35°C), and observing the development of patina on the surface of the coating 72 hours after spraying.

As a result, no patina was observed in the coating film obtained from the conductive paint of the present invention.

Comparative Experimental Example 8 Salt Water Spray Test on Paint Film A conductor circuit was formed on an acrylic board in the same manner as Experimental Example 4, and a salt water spray test was conducted. The salt spray test was based on the JIS standard, using an aqueous solution with a salt water concentration of 5% by weight (liquid temperature: 35°C), and observing the development of patina on the surface of the coating 72 hours after spraying.

As a result, 50 to 100% of the coating film obtained from the comparative conductive paint exhibited severe patina.

From the results of Experimental Example 7 and Comparative Experimental Example 8 above, it was found that the coating film obtained from the conductive paint of the present invention had good durability that could withstand salt water spray.

Experimental Example 9 Adhesion of Coating Film The conductive paint of the present invention prepared in Experimental Example 3 was printed on an acrylic substrate, a polyester substrate, a phenol substrate, a glass epoxy substrate, a glass substrate, and an alumina ceramic Ml using a screen printing machine. A 2×2 dragon pad coating was formed and a 90° boulevard test was conducted. This test uses a room temperature curing epoxy resin on top of the paint film.
A 5φm+s tin-plated copper wire was attached. The thickness of the coating film was 70±20 μm.

As a result, the peel strength of the acrylic substrate was 0.8 to 1. 0k
g/mrr? , peel strength 0, 8-1 on polyester substrate
．． 0kg/mrr? , peel strength 0.0 for phenol substrate.
9-1.0kg/mrf, peel strength with glass epoxy substrate 0.9-1.0kg/m, peel strength with glass substrate 0
．． 8~1.0kg/mrr? , peel strength of alumina ceramic substrate 0.8-1.1kg/mrr? Met.

Comparative Experimental Example 10 Adhesion of Coating Film The comparative conductive paint prepared in Experimental Example 4 was printed on an acrylic substrate, a polyester substrate, a phenol substrate, a glass epoxy substrate, a glass substrate, and an alumina ceramic substrate using a screen printing machine. Therefore, 2X2+am
A pad coating was formed and a 90° pool test was conducted. This test uses a room temperature curing epoxy resin on top of the paint film.
This was done by gluing 5φ dragon tin plated copper wire. The thickness of the coating is
It was 70±20 μm.

As a result, the peel strength of the acrylic substrate was 0.5 to 0.6 kg.
/mrr? , Peel strength on polyester substrate: 0, 5~
0.6 kg/mrr? , phenol substrate with peel strength of 0.5 to 0. 6kg/mrr? , peel strength of glass epoxy substrate is 0. 5-0. 6kg/mry
? , the peel strength is 0.0 on the glass substrate. 5-0. 6kg/m
rrr, peel strength 0.5~ with alumina ceramic substrate
It was 0.6 kg/m.

From the results of Experimental Example 9 and Comparative Experimental Example 10 above, it was found that the coating film according to the present invention has adhesiveness to all substrates.

An electron micrograph of a cross section of a 2×2+am coating film according to the present invention is shown in FIG. From this sample No. 45, a good dispersion state of the copper powder in the resin binder and a strong adhesion state between the base material and the resin binder were observed.

An electron micrograph of a cross-section of a 2×2 coating film for comparison is shown in FIG. From this photograph, poor dispersion of the copper powder in the resin binder and poor adhesion between the base material and the resin binder due to unevenness of the copper powder can be observed.

Experimental Example 11 Electromagnetic Shielding Effect The conductive paint of the present invention obtained in Experimental Example 3 was applied to an acrylic plate by a spray method, and was applied under the initial, high temperature conditions of 85°C, and at 60°C/
The electromagnetic shielding effect after aging for 1350 hours under high humidity conditions of 95% RH was measured by the Atopane test method.

The thickness of the coating film was 70±20 μm.

The results are as follows.

At a frequency of 500 M) Iz and initial conditions, the coating according to the invention has a shielding effect in the near field (electric field) of 54-62 dB, a shielding effect in the near field (magnetic field) of 52-64 dB, and a shielding effect in the far field of 47-56 dB. Demonstrated shielding effect in the world.

Also, frequency 500MHz, high temperature of 85℃, 1350℃
Under conditions after standing for a period of time, the coating film according to the present invention has a 42 to 5
Shielding effect in 4 dB near field (electric field), 41-54
Shielding effect in dB near field (magnetic field), 37-52d
This shows the shielding effect of B in the far field.

Furthermore, under the conditions of a frequency of 500 MHz, high humidity of 60°C/95% RH, and after being left for 1350 hours, the coating film according to the present invention has a near field (electric field) shielding effect of 44 to 58 dB, and a near field shielding effect of 45 to 58 dB. (magnetic field) and a shielding effect in a far field of 40 to 57 dB.

Comparative Experimental Example 12 Electromagnetic Shielding Effect The comparative conductive paint obtained in Experimental Example 4 was applied to an acrylic plate by a spray method, and was applied under the initial, high temperature conditions of 85°C, and 60°C/95°C.
The electromagnetic shielding effect after aging for 1350 hours under high humidity conditions of %RH was measured using the atpan test method. The thickness of the coating film was 70±20 μm.

The results are as follows.

At a frequency of 500 MHz and initial conditions, the comparative coating film was 4
Shielding effect in near field (electric field) of 0 to 50 dB, 39
~46dB near field (magnetic field) shielding effect, 34~
It showed a shielding effect in the far field of 41 dB.

Also, frequency 500M1lz, high temperature of 85℃, 135
Under conditions after 0 hours of standing, the comparative coating film was 25 to 39 dB.
It showed a shielding effect in a near field (electric field) of 25 to 34 dB, a shielding effect in a near field (magnetic field) of 23 to 31 dB, and a shielding effect in a far field of 23 to 31 dB.

Furthermore, under the conditions of a frequency of 500 MHz, high humidity of 60°C/95% RH, and after being left for 1350 hours, the comparative coating film was 2.
Shielding effect in near field (electric field) of 9 to 39 dB, 29
~34dB near field (magnetic field) shielding effect, 25~
It showed a shielding effect in the far field of 34 dB.

From the above results, the coating film made of the conductive paint of the present invention containing a mixture of titanium acylate polymer and higher carboxylic acid ester shows extremely excellent electromagnetic shielding effect both in the initial stage and after aging, and is heat resistant and moisture resistant. It was found that it has aging properties.

[Brief explanation of the drawing]

Figure 1 is a 700x scanning electron micrograph showing the structure of copper powder particles in a cross section of a coating film of the paint according to the present invention, and Figure 2 shows the structure of copper powder particles in a cross section of a coating film of a comparative paint. This is a scanning electron micrograph at 700x magnification. Applicant's agent Mr. Sato

Claims (1)

[Claims] 1. A conductive composition comprising copper powder, a resin binder, a dispersant of a titanium acylate polymer and a higher saturated fatty acid ester, and a solvent. 2. The conductive composition according to claim 1, wherein the copper powder is coated with a mixture of a titanium acylate polymer and a higher saturated fatty acid ester. 3. The conductive composition according to claim 2, wherein the amount of the mixture of titanium acylate polymer and higher saturated fatty acid ester coated on the copper powder is 0.1 to 10% by weight. 4.Claim 1, wherein the resin binder is a thermoplastic resin.
4. The conductive composition according to any one of items 3 to 3. 5. The conductive material according to any one of claims 1 to 4, wherein the copper powder content is 40 to 90% by weight and the resin binder is 10 to 60% by weight, based on the weight of the conductive composition excluding the solvent. Composition. 6. Titanium acylate polymer has the following repeating unit I,
The conductive composition according to any one of claims 1 to 4, which is a condensate of dimer or more having II and/or III. ▲There are mathematical formulas, chemical formulas, tables, etc.▼...I ▲There are mathematical formulas, chemical formulas, tables, etc.▼...II ▲There are mathematical formulas, chemical formulas, tables, etc.▼...III (In the formula, R' is Hydrocarbon group having 1 to 10 carbon atoms, OCO
R^1, R of R^1, OCOR^2 and OCOR^3
^2 and R^3 are the same or different carbon numbers 1 to 17
is a hydrocarbon group, l and m are 1>1 and m, respectively.
>1, and n satisfies n≧1) 7. The conductive composition according to any one of claims 1 to 6, wherein the higher saturated fatty acid ester is represented by the following general formula. RCOOR' (in the formula, R is a hydrocarbon group having 1 to 17 carbon atoms, R' is a hydrocarbon group having 1 to 10 carbon atoms) 8, based on the weight of the conductive composition excluding the solvent, The conductive composition according to any one of claims 1 to 7, wherein the total content of the rate polymer and higher saturated fatty acid ester is 0.05 to 10% by weight. 9. The mixing ratio of titanium acylate polymer and higher saturated fatty acid ester is 20 to 80
The conductive composition according to any one of claims 1 to 8, which contains 80 to 20% by weight of higher saturated fatty acid ester.