JPS6289780A - Conductive adhesive composition - Google Patents

Abstract

PURPOSE:To obtain the titled composition of good storage stability, easy to handle, capable of instantaneously working at ambient temperatures for coating, by useful for fixation of lead wire joints, by blending specific cyanoacrylate, conductive powder, acidic substance and basic substance. CONSTITUTION:The objective composition can be obtained by blending (A) 2-cyanoacrylate, (B) conductive powder (e.g., of silver), (C) an acidic substance (e.g., boron trifluoride) and (D) a basic substance (e.g., amine), successively, for example, in this order followed by agitation. The component B is preferably used after being brought into contact with an acid or coupling agent (i.e., surface-treating agent).

Description

Detailed Description of the Invention (a) Purpose of the Invention "Industrial Application Field" The composition of the present invention is used in the electrical and electronic materials industry for fixing lead wires to contacts, making circuits, and coating for electromagnetic shielding. It is used for such purposes and is widely used in the electronic equipment industry, electrical machinery industry, and general machine manufacturing industry.

"Prior Art" Conventionally, for the above-mentioned purposes, paints, conductive paints, etc. have been widely used and have played an important role.

Also, fast curing of 2-cyanoacrylate adhesives.

Attempts have also been made to add conductive powder to a 2-cyanoacrylate adhesive and use it as a conductive adhesive.

``Problems to be solved by the invention'' ・The wire used for fixing lead wires, etc. needs to be heated when it is used, which deteriorates the performance of electronic components and requires the energy of a large amount of VC1. It has points.

Further, conventional conductive paints also have the problem that they require a large amount of heat or light to cure, and also take a long time.

Furthermore, attempts have been made to add conductive powder to 2-cyanoacrylate adhesive and use it as a conductive adhesive, but it is difficult to stably disperse the conductive powder in 2-cyanoacrylate, and furthermore, it is difficult to disperse the conductive powder stably in 2-cyanoacrylate, and Storage for a period of time (also in some cases, 2-
There is a problem in that cyanoacrylate deteriorates so severely that it is not suitable for practical use.

The inventors of the present invention conducted extensive research to find a conductive adhesive that does not have the above-mentioned problems.

(b) Structure of the invention "Means for solving the problem" The present inventors have discovered that the above problem can be solved by using 2-cyanoacrylate, a conductive powder, an acidic substance, and a basic substance in combination. Heading The invention has been completed.

That is, the present invention relates to a conductive adhesive composition characterized by containing four components: A; 2-cyanoacrylate B; conductive powder C; acidic substance D; and basic substance.

o2-cyanoacrylate In the present invention, 2-cyanoacrylate (2-cyanoacrylic acid ester) is the main component of cyanoacrylate adhesives widely used as instant adhesives.
In the present invention, it is also possible to use these instant adhesives as they are as 2-cyanoacrylate.

Specific examples of 2-cyanoacrylates used in instant adhesives include the following esters, and in the present invention, it is of course possible to use them alone or in combination of two or more. Methyl, ethyl, chloroethyl, n-7', i-7', allyl, propargyl, n-butyl, i-butyl, t-butyl, n-pentyl, n-hexyl, cyclohexyl, phenyl of cyanacrylate , tetrahydrofurfuryl, heftyl, 2-ethylhexyl, n
- esters such as octyl, nonyl, oxononyl, decyl, n-dodecyl, ethoxyethyl, 6-medoxyptel, ethoxyethogylethyl, trifluoroethyl, and hexafluoroisopropyl.

02. Qualitative Powder The conductive powder used in the present invention may include various conductive powders. Specific examples include silver, copper, nickel, aluminum, gold, palladium, platinum, These include ruthenium and composite powders containing them.

The conductive powder in the composition of the present invention is preferably 10 to 4 parts by weight per 100 parts by weight of 2-cyanoacrylate.
00 parts by weight, more preferably 100 to 600 parts by weight (if the proportion exceeds 400 parts by weight, there is a risk that the storage stability and adhesive strength of the composition will decrease). , the adhesive performance will not be damaged,
If the number of overlapping parts is less than 10, it becomes difficult to impart sufficient electrical conductivity to the composition, which is the objective of the present invention.

It is preferable to bring the conductive powder used in the present invention into contact with an acid or a coupling agent (surface treatment agent) before using it in the present invention, since the desired effects of the present invention are further improved.

Examples of acids whose effects can be improved by contacting the conductive powder include protonic acids or their anhydrides, and specifically, inorganic acids such as hydrochloric acid, sulfuric acid, and phosphoric acid, and organic acids such as those exemplified below. Examples include acids, organic acid anhydrides, and organic acid esters having an acid group5. Examples of organic acids include acetic acid, propionic acid, butyric acid, trifluoroacetic acid, valeric acid, hexanoic acid, malonic acid, succinic acid, glutaric acid, Adipic acid, maleic acid, fumaric acid, cinnamic acid, benzoic acid, methanesulfonic acid, toluenesulfonic acid, trifluoromethanesulfonic acid, toluenedisulfonic acid, itaconic acid, aconitic acid, phthalic acid, trimellitic acid, etc. Examples of organic acid anhydrides include acetic anhydride, propionic anhydride, butyric anhydride, valeric anhydride, succinic anhydride, glutaric anhydride, adipic anhydride, maleic anhydride, itaconic anhydride, aconitic anhydride, phthalic anhydride, and trimellitic acid, etc.

Examples of the acidic acid ester having an acid group include compounds such as ethylene glycol ditrimellitate, trimethylene glycol ditrimellitate, and Ricarezino TM i'A (part name manufactured by Shin Nippon Chemical Co., Ltd.).

Preferred acids among these acids are organic acids such as toluenesulfonic acid and organic acid anhydrides such as trimellitic anhydride.

Various types of coupling agents (surface treatment agents) can be used, and specific examples include β-15, β-15,
4)-Epoxycyclohexylethyltrimethoxysilane, α-chloropropyltrimethoxysilane, γ-glycidoxyglobyltrimethoxysilane, vinyltriacetoxysilane, vinyltriethoxysilane, vinyltrichlorane, vinyltris(2-methoxyethoxy)
Silane, vinyltrimethoxysilane, r-methacryloxypropyltrimethoxysilane, ethyltrimethoxysilane, butyltrimethoxy7rane, octyltrimethoxysilane, phenyltrimethoxysilane, dimethylsiloxane oil, hexamethylsilazane, isopropylinstearoyl diacrylic Titanate, Isopropyl dimethacrylic isostearoyl titanate, Isopropyl triisostearoyl titanate, Isobrobyl trioctainoltitanate, Isopropyl tricumylphenyl titanate, Isopropyl tris(dioctyl pyrophosphate) titanate, Isopropyl tri(dioctyl phosphate) titanate, Isopropyl tridodecylbenzenesulfonyl Titanate, dicumylphenyloxyacetate titanate, diisostearoyl ethylene titanate, tetraisopropyl bis(dioctyl phosphite) titanate, tetraoctyl bis(ditridecyl phosphite) titanate, tetra(2,2
-diallylmethyl-1-butyl)bis(di-tridecyl)phosphite titanate, bis(dioctylpyrophosphate)ethylene titanate, bis(dioctylpyrophosphate)oxyacetate titanate, and the like.

In addition, in the present invention, it is also possible to use a conductive powder that has been brought into contact with the above acid and a coupling agent at the same time.

A method for bringing the conductive powder used in the present invention into contact with an acid or a coupling agent such as the above-mentioned inorganic acid, organic acid, organic acid anhydride, or organic acid ester having an acid group is to immerse it in a solution of the agent. However, some of these drugs are strong acids or are solid at room temperature, so it is best to use them as a solution in the dipping or application process as a contact method. This is a preferable method from the viewpoint of not impairing the properties of the material.

The solvent for preparing the solution is not particularly limited as long as it is used as a solvent, but the following solvents are preferably used.

Water, aliphatic alcohols having up to 9 carbon atoms such as methanol, ethanol, cyclohexanol, etc., ketones having up to 9 carbon atoms such as acetone, methyl ethyl ketone, esters from acids with up to 3 carbon atoms and alcohols having up to 7 carbon atoms, such as ethyl acetate. , butyl acetate etc., aliphatic ethers such as diethyl ether, tetrahydrofuran, dioxane etc., halogenated hydrocarbons such as chloroform, trichloroethane, trichlorotrifluoroethane etc.

There is no difference in the effect of the present invention whether these solvents are used alone or as a mixed solvent.

The concentration of the drug in the solvent solution is preferably 20% by weight or less, more preferably 0.5 to 5% by weight.

The method of bringing the powder into contact with the above-mentioned drug, that is, immersing it in a solution of the above-mentioned drug or applying the solution, includes:
The conventional method is to immerse the powder in the same solution for about 1 minute to 1 hour at room temperature or apply it with a spray gun.
It is preferable to separate the excess bath liquid by static separation, centrifugation, etc. [14.3. The acidic substances used in the present invention refer to electron pair acceptors and their coordination complexes, and include, for example, boron trifluoride and its derivatives, sulfo/acids, and halogenated aliphatic carbon atoms. Examples include acids and 57) hyaluronan, phosphorus hexafluoride, etc.

Examples of boron trifluoride and its derivatives include boron trifluoride, boron trifluoride acetate complex, boron trifluoride formate complex, boron trifluoride propionate complex, boron trifluoride butyrate complex, and boron trifluoride benzoate. Acid complex, boron trifluoride methyl ether complex, boron trifluoride ethyl ether j-4, boron trifluoride n-glopylether complex 1
41:, boron trifluoride isopropyl ether complex, boron trifluoride n-butyl ether complex, boron trifluoride tetrahydro 7-rane complex, boron trifluoride ethyl formate complex, boron trifluoride methyl acetate complex, boron trifluoride Examples include ethyl acetate complex, boron trifluoride methanol complex, boron trifluoride boron fluoride benzonitrile complex, and fluoroboric acid.

In addition, sulfonic acids include toluenesulfonic acid, )IJ
Examples include fluoromethanesulfonic acid, chlorosulfonic acid, fluorosulfonic acid, magic acid, and 2-sulfonebenzoic anhydride.

Furthermore, examples of halogenated aliphatic carboxylic acids include trifluoroacetic acid, trichloroacetic acid, dichloroacetic acid, and the like.

Among the above compounds, preferred compounds for the present invention are boron trifluoride, boron trifluoride acetic acid complex, boron trifluoride ethyl ether complex, boron trifluoride methanol complex, boron trifluoride phenol complex, and the like. Boron and its derivatives sulfonic acids such as toluenesulfonic acid, trifluoromethanesulfonic acid, chlorosulfonic acid, and fluorosulfonic acid; particularly preferred compounds are boron trifluoride acetic acid complex, boron trifluoride ethyl ether complex, toluenesulfone acids, trifluoromethanesulfonic acid and dichlorosulfonic acid.

The amount of the above-mentioned acidic substance in the composition of the present invention is 10 to 10 s based on the 2-cyanoacrylate present in the composition.
The amount is preferably from 100 to 5,000 ppm, and more preferably from 100 to 5,000 ppm. If this amount is less than 10 ppm, it will be difficult to stably cause the conductive powder to exist in the composition, and
If it exceeds 0 ppm, the curing speed of the composition will be slow;
This is not preferable because instantaneous adhesion cannot be expected.

0 Basic Substances The basic substances used in the present invention refer to electron donors, and specifically include amines, crown ethers, polyalkylene glycols and derivatives thereof, fatty acid amides, and the like.

The amines include triethylamine, triethanolamine, aniline, N,N-dimethylaniline, N,
Examples include N-diethylaniline, toluidine, N,N-dimethyltoluidine, N,N-diethyltoluidine, polyvinylpyridine, polyvinylcarbazole, and polyvinylpyrrolidone.

Crown ethers include 18-crown-6,
15'-crown-5,12-crown-4,1,1-
Dimethylsilar 11-crown-4,1,1-dimethylsilar 14-crown-5,1,1-dimethylsilar 1
7-crown-6, keto-11-crown-4, keto-
14-crown-5, keto-17-crown-6,1-
Methylphosphono-11-crown-4,1-ethylphosphono-11-crown-4,1-phenyl-11-crown-4,1-methylphosphono-14-crown-5,
1-Ethylphosphono-14-crown-5,1-phenyl-14-crown-5,1-methylphosphono-17-
Crown-6,1-ethylphosphono-1fucrown-
Examples include 6,1-phenylphosphono-1fucrown-6.

Polyalkylene glycols and their derivatives include polyethylene glycol, polyethylene glycol methyl ether, polyethylene glycol ethyl ether,
Polyethylene glycol acrylate, polyethylene glycol methacrylate, polypropylene glycol, amylphenol/decaethylene glycol, p-octylphenol/decaethylene glycol, polyethylene glycol 400 monolaurate, polyethylene glycol oleate, polyethylene glycol tall oil ester, polyethylene glycol sorbitan mono Laurate, alkyl polyethylene glycol thioether, oleyl polyethylene glycol ether, ethylene glycol propylene glycol pronoc copolymer, (polyoxyethylene) polysilalt, (polyoxypropylene) polysilalt, (polyoxyisoprene) polysilal- (polyoxytetramethylene) polysilate, (polyoxyethylene/succinic acid) polyester, (polyoxypropylene/succinic acid) polyester, (polyoxyisoprene/succinic acid) polyester, (polyoxytetramethylene/succinic acid) ) polyester, (polyoxyethylene/malonic acid) polyester, (polyoxypropylene/malonic acid) polyester, (polyoxyisoprene/malonic acid) polyester,
(polyoxytetramethylene/maron ff) polyester, (polyoxyethylene/phthalic acid) polyester,
(BOIJ, t-xypropylene/phthalic acid) polyester, (polyoxyisoprene/phthalic acid) polyester, (polyoxytetramethylene/phthalic acid) polyester, (polyoxyethylene) polycarbonate, (polyoxyethylene) polyphosphate, ( polyoxypropylene) polyphosphate, (polyoxyisoprene)
Examples include polyphosphate, (polyoxytetramethylene) polyphosphate, (polyoxyethylene) polyphosphonate, etc.

Furthermore, fatty acid amides include lauric acid monoethanolamide, lauric acid jetanolamide, coconut oil fatty acid monoethanolamide, coconut oil fatty acid jetanolamide, caprylic acid ethanolamide, capric acid ethanolamide, myristic acid ethanolamide, and valmitic acid ethanol. amide, stearic acid ethanolamide, caprylic acid impropaturamide, capric acid isopropaturamide, myristic acid isopropaturamide, palmitic acid impropaturamide, stearic acid isopropaturamide, etc.
) Among the above basic substances, preferred compounds for the present invention are crown ethers, polyalkylene glycols and derivatives thereof, and particularly preferred compounds are 18-crown-6, polyethylene glycol, polyethylene glycol methyl ether, polyethylene glycol ethyl ether, Polyethylene glycol acrylate, polyethylene glycol methacrylate, polypropylene glycol, polyethylene glycol 400 monolaurate,
Polyethylene glycol oleate, alkyl polyethylene glycol thioether, ethylene glycol brobylene glycol pronoc copolymer, oleyl polyethylene glycol ether theal.

The amount of the above-mentioned basic substance in the composition of the present invention is 10 to 5
The amount is preferably 0,000 ppm, more preferably 100 to 5. DOOppm. If this amount is less than 10 ppm, the curing speed will be slow, and if it exceeds 50,000 ppm, the stability will be poor, which may render the adhesive composition useless. do not have.

The ratio of acidic substances and basic substances in the composition of the present invention varies depending on each substance, but in general, when the ratio of the acidic substance and the basic substance is equimolar or slightly excessive, the storage stability and -Vt It is easy to obtain the effect of fast curing speed on the surface of the adherend.

○Preparation method The composition of the present invention may be prepared by simply mixing the above four components constituting the composition M1 of the present invention.
Or, when considering the stability of 2-cyanoacrylate,
A preferred method is to add an acidic substance, a basic substance, and 4 electric pole powder to 2-cyanoacrylate in this order and mix them with stirring. Note that when acidic substances and basic substances are mixed alone, some or all of them form salts or complex salts, but even if such forms are used, the purpose of the present invention cannot be achieved. This effect can be fully obtained.

MM As I did, I also used 0T11 using a commercially available cyanoacrylate adhesive as 2-cyanoacrylate.
Stabilizers, thickeners, plasticizers, crosslinking agents, etc. that are usually added to cyanoacrylate adhesives may be added to the composition of the present invention. As a stabilizer, for example, SO
□, sultone, lactone, hydroquinone, hydroquinone monomethyl ether, catechol, virocalol, etc. 1 to i for 2-cyanoacrylate,
oooppm added. Thickeners include methyl methacrylate polymer, 2-cyanoacrylate polymer,
Several polymers such as acrylic rubber are added. Plasticizers include dioctyl phthalate, sebanic acid ester, phosphoric acid ester, etc., and crosslinking agents include alkylene diacrylate, alkylene dimethacrylate,
Examples include polyfunctional vinyl monomers such as trimethylolpropane triacrylate and triallyl isocyanurate.

Furthermore, in order to increase the viscosity (and impart thixotropy), several thixotropic agents such as fumed silica should be added.

[-Action 1] In the adhesive composition of the present invention, the acidic substance and the basic substance combine to act as ρ on the surface of the conductive powder, stably dispersing the conductive powder, and creating a conductive effect. It became possible to store the composition stably without damaging it.

Moreover, when the composition is applied to an adherend, it hardens due to a new effect of moisture on the surface of the adherend or in the air. It is possible to provide a conductive adhesive that can replace solder and conductive paint.

"Examples" The present invention will be specifically described below with reference to Examples and Comparative Examples.

Example 1 Silver powder was immersed in a methanol solution containing 5 parts by weight of para-toluenesulfonic acid and γ-methacryloxypropyltrimethoxysilane for about 10 minutes, and the silver powder adhering to the solution was collected by filtration. The solvent was then removed under reduced pressure in a vacuum for about 1Q hours to obtain a silver powder that had been in contact with the acid and the canogling agent.

2000 ppm of this powdered boron trifluoride ether complex
, polyethylene glycol 15001000 ppm
, 200 parts by weight for 100 parts by weight of ethyl 2-cyanoacrylate containing 5% by weight of polymethyl methacrylate.
A conductive adhesive composition was obtained by adding parts by weight and kneading at a constant temperature.The composition thus obtained was subjected to the following tests.

Storage stability: (2) after filling in a polyethylene container
Judgment was made based on the condition after being left for one month under conditions of 5±2° C. and 65±5% RH.

Chemical throat time is tested using a copper test piece according to JIS standards.
Measured according to K6861.

The curing time of the thin film is 25 μm after coating to a film thickness of 20 μm.
The time until the surface tank ran out was measured under the conditions of ±2°C and 65±5% l(H).

The specific resistance value of the cured product σ is 11] 5 + n x thickness 50
It was calculated from the resistance value in the length direction of a cured product of 11 m x 50 m length with 18 coatings. These results are shown in Table 1.33 Example 2-9 Using the compositions shown in Table 1, the same tests as in Example 1 were carried out. The results are shown in Table 1.

Comparative Example 1 10 parts by weight of ethyl 2-cyanoacrylate in 100 parts by weight of silver powder
When 0 parts by weight was added, ethyl 2-cyanoacrylate immediately underwent exothermic polymerization, rendering the adhesive composition useless.

Comparative Example 2 100 parts by weight of ethyl 2-cyanoacrylate was added to 200 parts by weight of silver powder treated with a 5-weight range methanol bath solution of para-toluenesulfonic acid, and the storage stability of the well-kneaded composition was observed. Thickening occurred in one week, and after one month it had almost completely cured, making it impossible to use it as an adhesive.

Comparative Examples 3 to 5 The same tests as in Example 1 were conducted using the compositions shown in Table 1. The results are shown in Table 1.

(c) Effects of the Invention By using the composition of the present invention, work such as fixing lead wires to contacts, fabricating circuits, and painting for electromagnetic shielding can be done instantly at room temperature with the desired effects, and furthermore, Electrical/electronic parts, plastic cases, etc. will not be damaged by heat.

Furthermore, the composition of the present invention has excellent storage stability and is easy to handle, so it can be effectively used under extreme pressure in the field of manufacturing electrical and electronic parts as a substitute for solder and conductive paint. , the effects produced by the composition of the present invention are immeasurable.

Claims (1)

[Scope of Claims] 1. A conductive adhesive composition characterized by containing the following four components. A: 2-cyanoacrylate B: Conductive powder C: Acidic substance D: Basic substance