JPS60118776A - Electroconductive adhesive composition - Google Patents

Abstract

PURPOSE:An alpha-cyanoacrylate adhesive composition that is obtained by adding an acid-treated metal powder or carbon powder to alpha-cyanoacrylate, thus showing stabililzed storability and good electroconductivity. CONSTITUTION:The objective composition is obtained by an acid-treated metal powder or carbon powder to alpha-cyanoacrylate and mixing them homogeneously. The amount of the carbon powder is 10-20wt% based on the alpha-cyanoacrylate, while the metal powder is 60-100%. Further, the addition of 1,000- 10,000ppm of hydroquinone and hydroquinone monomethyl ether as a stabilizer for alpha-cyanoacrylate, is preferred for increased storage stability.

Description

[Detailed description of the invention] TECHNICAL FIELD The present invention relates to α-cyanoacrylate-based adhesives.

More specifically, the present invention relates to a conductive α-cyanoacrylate-1-based adhesive composition characterized by adding acid-treated metal powder or carbon powder to α-cyanoacrylate-1.

The adhesive that is the object of the present invention is mainly composed of a compound having the following general formula.

(In the above formula, R represents an alkyl group of c, -c, or 6, an alkenyl group, an alkoxyalkyl group, a tetrahydrofurfuryl group, a phenyl group, a cyclohexyl group, etc.).

) When this compound is applied to bonding between two objects, the above compound is quickly applied to the bonding surfaces of two adherends, and the bonding surfaces are simply overlapped. Bonds extremely firmly within a few seconds to several tens of seconds without the need for pressure, heating, etc. Because of these properties of .alpha.-cyanoacrylate-1-, adhesives currently based on it are generally called instant adhesives.

Instant adhesives based on α-cyanoacrylate-1 are currently widely used in the production of precision instruments and light electrical equipment, and demand has recently increased for household use, including various metal products, ceramics, glass, and adhesives. Used for adhesion of products, plastic products, etc.

In this way, α-cyanoacrylate-1-based adhesives are required to have a variety of performances depending on the intended use, such as the target adherend, the method of adhesion, the time required for fixation, and the properties of the adhesive after adhesion.
Correspondingly, a wide variety of adhesive compositions of this type are commercially available.

Among these, in the light electrical industry, electronic parts are bonded together, and even after bonding,
There is a strong desire to provide conductivity between objects. For this reason, various companies have been making efforts to develop various conductive adhesives.

In general, the greatest obstacle in attempts to modify α-cyanoacrylate adhesives is the high activity characteristic of this type of monomer. Adding additives to α-cyanoacrylate generally increases the activity of the monomer, and even if it improves the desired properties, the storage stability of α-cyanoacrylate-1 adhesive deteriorates and becomes a product. It loses its value.

Therefore, in order to improve the α-cyanoacrylate-1 adhesive without impairing its storage stability, the number of substances that can be added is extremely small and difficult to predict, and furthermore, the amount of addition is also limited to an extremely small amount.

Under these circumstances, the present inventors have proceeded with the development of an α-cyanoacrylate-1-based adhesive that has the original properties of α-cyanoacrylate and has electrical conductivity without compromising storage stability. We have arrived at the present invention.

That is, the present invention is a conductive α-cyanoacrylate-1-based adhesive composition characterized by adding acid-treated metal powder or carbon powder to α-cyanoacrylate-1-.

To explain the present invention in more detail, all esters commonly used as instant adhesives can be used as α-cyanoacrylate-1- used in the present invention. These include, for example, methyl, ethyl, propyl, butyl, amyl, hexyl, cyclo\xyl, benzyl, phenyl, octyl, dodecyl, allyl, propargyl, di-xyethyl, furfuryl, di-hydro α-cyanoacrylates such as furfuryl, chloroethyl, fluoroethyl', and hexafluoroethyl.

The conductivity-imparting substance that can be used in the present invention is acid-treated metal powder or carbon powder, and metals include those normally used as conductive adhesives for plastics, such as gold, silver, nickel, etc. Examples of Kobal 1 include aluminum, copper, iron, etc., but oxides, alloys, etc. of these may also be used. A composition in which metal powder or carbon powder is directly added to α-cyanoacrylate,
Although it varies somewhat depending on the metal extraction 51i, the amount added, etc., it generally tends to gel and solidify and has poor storage stability.

However, these powders treated with acid by an appropriate method can fully satisfy the first objective of the present invention.

For acid treatment of metal powder and carbon powder, inorganic or organic acidic substances such as hydrochloric acid, sulfuric acid, phosphoric acid, formic acid,
Wash with 1 volume of acetic acid, malic acid, succinic acid, p-+ luenesulfonic acid, benzenesulfonic acid, benzoic acid, etc. diluted in water or a solvent, or wash with an acidic gas such as SO2, C
Examples include a method of catalytically adsorbing o1, NO, etc.

The nails of acidic gas adsorbed as part of these iYJ treatments,
The degree of acidic solution used for cleaning may be arbitrarily selected depending on the type of acid used and the intended use.

The amount of acid-treated metal powder or carbon powder to be added should be determined appropriately depending on the intended use, but in the case of carbon powder, 10% If the amount is less than 10 parts by weight, the conductivity-imparting substance will be insufficient, and if it is more than 20% by weight, the adhesive will quickly gel and its storage stability will be poor. In addition, in the case of metal powder, it is desirable that the ratio is 60% to 10% (ljp: percentage) based on 1 to the monomer of α-cyanoatelyl.

The conductive adhesive of the present invention is made of α-cyanoacrylic acid-treated metal powder or carbon 1'5] unk i,
It can be easily applied by adding 1 and mixing uniformly.

The lambda thinning agent contains conventional α-cyanoacrylate-1 to Jt stabilizers (e.g. SO2, hydroquinone), thickeners (e.g. PMMA, PVAc), which are used in adhesives.
Colorants, solvents, etc. can also be used as additives.

Characteristics of the conductive adhesive 711J of the present invention (J mentioned above, 1
Its purpose is to exhibit excellent conductivity without sacrificing the properties of conventional α-cyanoacrylates, and it is usually used as a stabilizer for α-cyanoacrylates. Hydroquinone and Hyde 1. j;\If you use more non-monomethyl ether than the normal amount,
Preferably 1000 for α-cyanoataryl 1-
When ~110,000 pp was added, an improvement in storage stability was observed that could not be expected with the normal addition amount.

Although the reason for this surprising phenomenon is not clear, it is thought to be due to some kind of interaction between the acid-treated metal powder or carbon powder and hydroquinone.

Thus? α-cyanoacrylate-1- of the present invention
It goes without saying that conductive adhesives exhibit excellent effects when used to bond adherends mainly made of metal that require electrical conductivity, but they can also be used to bond adherends that require electrical conductivity, such as conventional α-C'noacrylic adhesives.
- It can also be used as an instant adhesive on various adherends such as plastics, ceramics, wood, glass, etc. to which the adhesive is applied.

The present invention will be clarified by the following examples and shark examples, but the present invention is not limited to these examples. In the example, the conductivity of a 3 dM fat is 14 product 11 (expressed as resistivity, but if the volume resistivity is measured ^S'l'M-11-2734I
It was carried out according to the method.

In addition, for the storage stability test, the adhesive was placed in a 20 cc polyethylene container, sealed, and placed in a 70-inch circulating tank, and the number of containers until the adhesive was assimilated was measured.

Ta.

Furthermore, regarding adhesive speed and adhesive strength, the former S K (il
i61 "Test method for cyanoacrylate-1-based adhesives" was followed.

Examples 1 to 11, Comparative Examples 1 to 4 Dry nitrogen gas is circulated in a polyethylene container containing dried carbon powder at a flow rate of 1.501/l+r for 8 hours. Then, while shaking the polyethylene container,
After reaching the desired adsorption nail shown in Table 1, the blowing of the 5()2 gas was stopped, and the mixture was allowed to stand for about 1.41 hours to obtain SOx gas adsorbed carbon.

30220ppm and star hydroquinone shown in Table 1 with a small amount ++? Dissolved ethyl-α-cyanoacrylate-1
An adhesive composition was prepared by adding and mixing an amount of S (h) adsorbed carbon shown in Table 1 to .

Volume resistivity of bonded products using these adhesives.

The tensile shear strength and stability were measured and the results are shown in /<1.

The following can be seen from the results in Table 1.

By adding carbon powder to α-cyanoacrylate 1-, the adhesive becomes electrically conductive (=J-da), but the stability deteriorates deeply and the gelation occurs in a short period of time. Even if the drug is increased, the effect is poor.

By adding acid-treated carbon powder, α-cyanoacrylate-1 has a good shelf life! LR conductive adhesive could be obtained. It is clear that increasing bar-droquinone in this adhesive doubles the storage stability without compromising the physical properties of the adhesive pond.

Examples 12-17, Comparative Examples 5-8 Silver powder 50H was placed in IOwL, % acetic acid-dichloromethane solution at 5°Og and stirred for about 1 hour. Filter this and tR
The m powder was taken out and dried at a constant temperature of 80''C until it became a star to obtain an acid-treated metal powder.

An adhesive composition was prepared by adding and mixing the star acid-treated metal powder shown in Table 2 to ethyl-α-cyanoacrylate-1- in which 20 ppm of S(b) and hydroquinone in the amount shown in Table 2 were added and dissolved.

Volume resistivity of adhesives using these adhesives.

The tensile shear strength and stability were determined as 1l11, and the X-1 results are shown in Table 2.

Claims (1)

[Claims] 1. A conductive α-cyanoacrylate-1 adhesive composition, characterized in that α-cyanoacrylate is added with acid-treated metal powder or carbon powder.