JPS61296077A - Electrically-conductive adhesive of two-pack contact curing type - Google Patents

Abstract

PURPOSE:The titled adhesive of cold-setting type useful as an electromagnetic wave-shielding material, etc., having high curing rate, obtained by adding a (meth)acrylate polymer, a (meth)acrylate monomer and an electrically-conductive material to both solutions, a polymerization initiator to one of the solution and a polymerization initiator to the other. CONSTITUTION:(A) A (meth)acrylate (co)polymer or oligomer or their mixture (e.g., methyl methacrylate polymer, etc.), (B) a (meth)acrylate monomer and (C) an electrically-conductive material (e.g., Ni, etc.) in a ratio of the components A+B: the component C=35:15-65:85 (weight ratio) are added to both solutions, (D) a polymerization initiator is added to one of them and, (E) a polymerization promoter is added to the other, to give the aimed adhesive.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an adhesive that is used particularly for adhering or fixing electronic parts, etc., and is also used as an electromagnetic shielding material, and is particularly a room temperature curing type adhesive. The present invention relates to a two-liquid contact curing type conductive adhesive which has a fast curing speed and strong adhesion to plastic materials, metals, etc.

[Prior art and its problems]

BACKGROUND ART Epoxy-based adhesives are conventionally known as conductive adhesives used for adhering or fixing electronic components or as electromagnetic shielding materials. There are two types of epoxy adhesives: one-part type and two-part type. -The disadvantage of liquid-type epoxy adhesives is that they do not harden unless heated, so they cannot be used for electronic parts that are sensitive to high temperatures.
It was not suitable for use in mass production processes because of its limited use locations and slow curing speed.

However, the disadvantage of two-component epoxy adhesives is that they are mixed curing types, which require accurate measurement of the two components and thorough mixing, making them difficult to work with and not suitable for mass production. Furthermore, there was a lot of waste because there was leftovers.

Furthermore, both one-component and two-component epoxy adhesives have poor adhesion to plastic materials such as ABS' and styrene, making it difficult to use them as electromagnetic shielding materials.

[Purpose of the invention]

The object of the present invention is to be a room-temperature curing type, which has a fast curing speed, and has high adhesion to various plastic materials, and is a contact curing type, in which two components are applied separately to an adherend and then come into contact with each other. To provide a two-component contact curing adhesive that can be bonded with a chisel, does not require accurate metering or mixing operations of two components, and therefore does not leave any unused adhesives or waste, and improves the drawbacks of the above-mentioned known techniques. It is in.

[Key points of the invention]

In order to achieve the above object, according to the present invention, both of the two components contain a polymer, copolymer or oligomer of (meth)acrylate, or a mixture thereof (component A);
meth)acrylate monomer (component) and conductive material (
It is characterized in that one of the two liquids contains a polymerization initiator (component 2) and the other contains a polymerization accelerator (component e).

The aforementioned component A is a polymer, copolymer or oligomer of (meth)acrylic ester, vinyl ester or unsaturated polyester, or a mixture thereof, specifically methyl methacrylate polymer, ethyl methacrylate polymer, methyl acrylate polymer. ,
selected from ethyl acrylate polymers, ethylene acrylic copolymers, or isobutyl methacrylate copolymers, vinyl propionate or styrene acrylic copolymers, polyester polymers, etc.
Particularly preferred among these are methyl methacrylate polymers, vinyl propionate or styrene acrylic copolymers, and ethylene acrylic copolymers.

The aforementioned ingredients are recognized as factors that affect adhesion to adherends, storage stability, and curing speed, and are compatible with the aforementioned polymers, copolymers, or oligomers, and specifically include methyl methacrylate. , ethyl methacrylate, glycidyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, ethylene glycol dimethacrylate, dipropylene glycol dimethacrylate, trimethylolpropane trimethacrylate, dimethacrylate with ethylene oxide added to bisphenol A, methoxydiethylene glycol methacrylate, Neopentyl glycol diacrylate, tetrahydrofurfuryl methacrylate, teirahydrofurfuryl acrylate, ethyl methacrylate, phenoxyethyl acrylate, butoxyethyl acrylate, ethylcarpitol acrylate, 1,3-butylene glycol dimethacrylate, 1,6- Hexanethiol dimethacrylate, neopentyl glycol dimethacrylate, 2-hydroxy 1,3-dimethacryloxypropane dimethacrylate, or a mixture thereof.In addition, the aforementioned component C, that is, the conductive material is Ni
, Ag, A-11, A1. , a metal conductive material such as Cu, a non-metallic conductive material such as carbon, and preferably Ni or Ag.

Furthermore, the aforementioned component 2, that is, a polymerization initiator, is diisopropylbenzene, hydroperoxide, cumene hydroperoxide, t-butyl hydroperoxide, methyl ethyl ketone peroxide, t-butyl peroxyisoglopyl carbonate, acetyl peroxide, hydrogen oxide, urea peroxide, diisopropyl ether peroxide, acetyl peroxide, tetralin hydroperoxide, cumene hydroperoxide, t-butyl hydroperoxide, or a mixture thereof;
Polymerization accelerators include thiourea and its derivatives, hydrazine and its derivatives, mercaptans, heavy metal chelate compounds, amines, Lewis acids, Schiff bases, etc. Specifically, N,N thylenetriamine, triethylenetetramine, penta Polyamines such as ethylene hexamine, thioureas such as thiourea, ethylene thiourea, benzoylthiourea, acetylthiourea, and tetramethylthiourea, organic or inorganic acid salts of metals such as copper, cobalt, manganese, and vanadium, ascorbic acid , mercaptans such as sodium sulfite, sodium hydrogen sulfite, sodium metasulfite, methyl mercaptan, and ethyl mercaptan.

The above-mentioned components (a), (1) and (c) are contained in both liquids, and components (2) and (e) are contained separately.

The blending ratio of these components is the total amount of component A and the conductive material, which are resin components, and the ratio by weight of component C, which is the conductive material.
A value in the range of 85 is good; if the amount of the conductive material (c) is more than the above range, the adhesive strength will decrease and the viscosity will become too high, making it unusable, and if it is less, the conductivity will decrease. do. Further, the appropriate mixing ratio of component A and component A is within the range of Yellow 20 = 80 to 35:65 by weight, but this ratio is not particularly limited as long as it has a viscosity that maintains a liquid state when conductive material C is added. .

Incidentally, in the present invention, in addition to the above-mentioned components (22), (22), (22), (22), and (5), radical polymerization inhibitors, adhesive force improvers, antioxidants, etc. may be used in combination.

Examples of radical polymerization inhibitors include methyl hydroquinone, catechol, hydroquinone monomethyl ether,
Monotert-butyl hydroquinone, 2,5 di-tert-butyl hydroquinone, P-benzoquinone, 2
, 5-diphenyl-P-benzoquinone, 2,5-ditertiary-butyl-P-benzoquinone, picric acid, phenothiazine, tertiary-butylcatechol, 2-butyl-4-hydroxyanisole, 2,6-ditertiary-butyl acresole, etc. can be used, and several types may be used in combination depending on the type of monomer and metal filler; particularly preferred are P-benzoquinone, 2
．． Examples thereof include 5-diphenyl-P-benzoquinone and 2,5-ditertiary-butyl-P-benzoquinone.

As the adhesive force improver, a phosphorus compound of bisacid phosphate is suitable, and as the antioxidant, a phenolic antioxidant is preferable, such as 2,6-di-tert-butyl-P-cresol, butylated Hydroxyrinizole, 2,2(-methylene-bis-(4-methyl-6-
tert-butylphenol), 2,6-di-t-butyl-
4-ethylphenol, 4,4'-thiobis-(3-methyl-6-tert-butylphenol), 2,2'-methylene-bis-(4-ethyl-6-tert-butylphenol), 4.4 '-Butylidene bis-(3-methyl-6-
tert-butylphenol), 1,1,3-tris-(2
-Methyl-4-hydroxy-5-tert-butylphenyl)butane, 1,3.5-)listyl-2,4,6-)lis(3,5-di-tert-butyl-4-hydroxybenzyl) ) benzene, tetrakis-[methylene-3-(3'
, 5'-di-tert-butyl-4'-hydroxyphenyl)propionate comethane.

A small amount of solvent may be added to make it easier to mix the adhesive.

When the adhesive of the present invention prepared as described above is used, for example, after applying two components separately to an adherend at room temperature, these coated surfaces are brought into contact with each other to quickly cure and bond, and to bond the adhesive to a plastic material. 0, which exhibits great adhesion even to
Therefore, the adhesive of the present invention not only has a fast curing speed and high adhesive strength, but also has good workability because it does not require accurate metering and mixing of two components unlike conventional epoxy adhesives. In addition, there is no leftover material, so there is no waste.

In the present invention, contact curing means that the reaction proceeds from the part where the two components come into contact to the entire two components, and there is no particular problem even if the two components are mixed in advance and used.

[Embodiments of the invention]

Hereinafter, the present invention will be explained in detail with reference to Examples.

Example-1 Two liquids (liquid A, liquid B) of each formulation shown in Table 1 were prepared.

The formulations (liquid A, liquid B) shown in Table-1 are shown in Table-2 below.
After applying liquid A uniformly to one side and liquid B to the other side in the same combination as shown, stick them together, rub them together once or twice to bond them, and after curing at 25°C for 24 hours, the adhesive strength and volume resistivity The test piece used in the zero adhesion test was J.
The test was carried out by measuring a copper plate (Ω·m) of 5H3100. In addition, in the storage test, 202 was placed in a plastic container, left in a constant temperature bath at 40°C, and the time until gelation was measured. It can be seen that it can be used without being limited to specific substances.

Example 2 In order to demonstrate that the amounts of liquids A and B are not fixed, the liquid mixtures shown in Table 3 were prepared.

Using the above formulation, the following two experiments 1) and 11) were conducted.

1) Changes in the conductivity of the adhesive wafer due to differences in the mixing ratio were measured using two curing methods, and the results are shown in Table 4.

Contact method C. Apply liquid A and liquid B to one of the two test pieces at a predetermined ratio and bond them together. (Contact curing) Mixing method C. Mix liquids A and B in advance at a predetermined ratio, and apply this mixed liquid to one of the two test pieces to adhere them. (Mixture curing) The measurement method was the same as in Example 1.

++) The strength of adhesion was measured by changing the material of the adherend.

The test heath was created by applying approximately equal amounts of A and B solutions using the contact method described in 1) and pasting them together.

Various measurements shall be made in accordance with I).

The test pieces used were Cu-Cu, ABS-ABS, and glass epoxy-glass epoxy.

Table 4 [Effects of the Invention] As described above, the present invention is a two-component contact curing conductive adhesive, in which both of the two components contain components A, C, and C, and either one of the two components contains Since component 2 is contained in one part and component E is contained in the other part, it is a room temperature curing type, has a fast curing speed, has high adhesive strength to various plastic materials, and can be used after separately applying the two parts to the adherend. It adheres only by contact with pressure, and does not require accurate metering or mixing operations of the two liquids, thus offering various advantages such as no leftovers and no waste.

Claims (1)

[Claims] Both of the two components contain a (meth)acrylate polymer, copolymer, or oligomer, or a mixture thereof (component A), a (meth)acrylate monomer (component B), and a conductive material (component C), and A two-component contact curing conductive adhesive comprising a polymerization initiator (component (d)) in one of the liquids and a polymerization accelerator (component (e)) in the other.