JPS60229966A - Electrically conductive paint - Google Patents

Abstract

PURPOSE:To provide an electrically conductive paint for the coating of an electric or electronic circuit, etc., keeping its electrical conductivity stably for a long period, and resistant to the degradation of the electrical conductivity of the coating film even under the exposure to a hot atmosphere, by adding a phosphorous acid ester to a paint composition composed mainly of the powder of copper, etc. and a resin component. CONSTITUTION:The objective paint can be prepared by compounding (A) preferably 50-95pts.(wt.) of the powder of copper or a copper alloy with (B) 5-50pts. of a resin component (e.g. acrylic ester resin), and adding (C) 0.1-10pts. of a phosphorous acid ester (e.g. trimethyl phosphite) to 100pts. of the mixture of the components (A) and (B). EFFECT:The cost can be reduced compared with a copper-based conductor.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved electrically conductive paint comprising a powdered material 8-1 based on copper or copper alloy.

Recently, with the development of electronic devices, the demand for electromagnetic shielding has increased, and currently, resin paints containing silver thread or nickel-based conductive materials are used as conductive paints for shielding. On the other hand, there is also an increasing demand for button paste as a conductor for electrical and electronic circuits. However, the use of silver is economically disadvantageous because it is expensive, and nickel-based conductive materials have poor performance in terms of conductivity. For these reasons, the use of copper powder or copper alloy powder as a conductive material is attracting attention, but copper-based powder is very easily oxidized, and even if it shows conductivity during preparation, it may be stored for a long time or the coating film may be heated to high temperatures. When placed in an atmosphere, conductivity is immediately lost.

For this reason, when electromagnetic shielding C2 is used with a conductive paint containing cap-type conductive material, the conductivity gradually decreases and the electromagnetic shielding performance deteriorates, and it is also used as a conductor for electrical and electronic circuits. Conductivity is lost during curing or deterioration over time, making it impossible to maintain the required characteristics.As a result of intensive research by the present inventors in order to improve these disadvantages, we found that some of these problems occur when copper-based materials are used as conductive materials. The present invention was completed based on the discovery that the deterioration of conductivity over time can be significantly suppressed by incorporating the following additives.

That is, the present invention relates to a conductive paint made by incorporating a phosphite into a silk composition mainly consisting of a powdered material based on copper or a metal alloy and a resin component. The conductivity is further improved and maintained stably for a long period of time, and even when the coating film is exposed to high temperature atmosphere, the deterioration of conductivity is extremely small, and it is significantly better than when using silver thread conductive material (( The advantage is that it is cost effective.

The following is a detailed explanation of ``Ki-ni IV''.

The copper or copper alloy powder used as the conductive material used in the present invention is preferably a spherical, dendritic, or scale-like powder with a particle size of 100 μm or less, and the copper alloy includes copper and zinc, Examples include copper-based materials (F@50% or more) consisting of soot, nickel, silver, etc.

Various resin components used in general paints include acrylic ester resins, vinyl chloride resins, vinyl chloride-vinyl acetate copolymers, vinyl chloride-vinylidene chloride copolymers, and ethylene. - Thermoplastic resins such as vinyl acetate copolymers and vinyl acetate resins, and thermosetting resins such as polyurethane resins, epoxy resins, phenolic resins, melamine resins, melamine alkyd resins, algide resins, and thermosetting acrylic resins are exemplified. Ru.

The mixing ratio of the conductive material and the resin component is 50 to 95 parts by weight (preferably 60 to 9 parts by weight) of the former and 5 to 50 parts by weight (preferably 10 to 9 parts by weight) of the latter resin component.
40 parts by weight), and the amount of the conductive material is 50 parts by weight.
If the amount is less than 95 parts by weight, the desired conductive properties will be insufficient, while if the amount exceeds 95 parts by weight, the film formability will be poor, and even if such a large amount is used, the conductivity will be insufficient. does not improve.

The present invention obtains the above effects by blending phosphorous esters into a commercial composition mainly consisting of such a copper or copper alloy conductive material and a resin component. Examples include trimethyl phosphite,
Alkyl phosphites, triphenyl phosphite, tris (nonyl Aryl phosphites such as phenyl) phosphite, tris(2,4-di-t-butylphenyl) phosphite, diphenyl monodecyl phosphite, diphenyl mono (tridecyl) phosphite, phenyl didecyl phosphite, phenyl di(tridecyl) phosphite Alkylaryl phosphite such as phosphite, dilauryl hydrogen phosphite, distearyl hydrogen phosphite, lauryl phenyl hydrogen phosphite,
Diester hydrogen phosphites such as diphenyl hydrogen phosphites, tetraphenyl dipropylene glycol diphosphites, tetraphenyl tetra(
tridecyl) pentaerythritol tetraphosphite, bisphenol A pentaerythritol phosphite, distearyl pentaerythritol diphosphite,
Dihydric alcohol-based or tetrahydric alcohol-based such as di-tridecyl-pentaerythritol fuji/phosphite, dinonylphenyl pentaeryth 9-to-diphosphite, and tetra(tridecyl)-4,4'-isobrohylidene diphenyl diphosphite. Polyphosphites such as bisphosphite, hydrogenated bisphenol A phosphite polymer, pentaerythritol/hydrogenated bisphenol/triphenylphosphite polycondensate are exemplified.

In addition to those exemplified above, chelators belonging to phosphorous esters that are commercially available as plastic stabilizers are also effective in achieving the object of the present invention.
This includes Adeka Argus' Mark C and Mark 1500.
, Mark SC! 101, Mark 5C102, etc., or Adbastab CH300J, Adbastab C) T400J, Adbastab cHsoo, r, etc. manufactured by Katsuta Kako Co., Ltd.

When using the various phosphorous esters mentioned above,
It is not limited to just the type, and two or more types may be used together at the same time, but the composition is the sum of the phase and the paint resin component! ?
It is best to add 0.1 to 10 parts by weight (preferably 0.5 to 5 parts by weight) per 100 parts by weight; if it is less than 01 parts by weight, the effect of addition will be small; on the other hand, if it is added in a large amount exceeding 10 parts by weight, However, no further effect will be obtained, and the physical properties of the coating film will deteriorate.

The conductive paint according to the present invention is usually diluted with an organic solvent to a coating-enabled concentration, and the organic solvent includes aliphatic hydrocarbons such as hexane, and aromatic hydrocarbons such as toluene and xylene. , esters such as ethyl acetate and butyl acetate, ketones such as methyl isobutyl ketone, alcohols, and the like.

This conductive paint C2 may contain plasticizers, curing accelerators, desiccants, thickeners, anti-skinning agents, anti-sagging agents, ultraviolet absorbers, antioxidants, resin stabilizers, etc. as necessary. may be added.

Next, a specific example will be given.

Example 1 (Meji experiment 1 to 12) 80 parts by weight of 'Tun' M copper powder with an average diameter of 20 μm, 20 parts by weight of the resin components (solid content equivalent) shown in Table 1 (2), A conductive paint was prepared by thoroughly mixing phosphorous esters of the type and amount shown in the same table using a mixing line.

A coating film was formed using a C near applicator to a thickness of 50 μm on the surface of a 75 μm polyester film, dried at room temperature for a day and night, and then dried with ventilation at 60° C. for 5 hours. A test piece was cut into a rectangle with a size of .

Each end of this test piece in the longitudinal direction had a width of 10 mm (two pieces were coated with silver paste to form electrodes, and the Yokogawa Hokushin Electric [
Digital multimeter MODe 12506A
When 'Qi and 'A resistance (volume specific resistance) were measured using J, the results were as shown in Table 1 (initial values). In addition, in order to check the heat resistance and durability of the conductive paint, the same table also shows the value of the volume resistivity measured after the test piece was left in air at 100+2° C. for a predetermined period of time.

(Types of resin components) R-1 Niacrylic resin, manufactured by Toshi Co., Ltd., product name 1 Kotax LG-5421 (solid content concentration 43% by weight) R-2: Polyurethane resin, manufactured by Dainippon Ink Co., Ltd. (2) liquid type), product name "Parnock DN-950, Acridic A 311" R-3: Epoxy resin, manufactured by Dainippon Toyo Co., Ltd. (two-component type), product name "Epoex #10 Clear 1 (phosphite ester) P-1 = Trimethyl phosphite P-2: Triethyl phosphite P-3: Tri-n-butyl phosphite P-4: Tridecyl phosphite, P-5:) Lis (2,4 -d-t-butylphenyl) phosphite P-6: Mark C (Chelator product name manufactured by Adeka Argus Co., Ltd.) P-7: Mark 1500 (Chelator product name manufactured by Adeka Argus Co., Ltd.) P-8 Niadopa tab CH300, T (Katsuyama Kako Co., Ltd.) Example 2 (Experiment/% 13-20) Metal components, resin components (solid content equivalent), and phosphite esters of the types and types shown in Table 2 C2 were mixed in a mixing machine. A conductive paint was prepared by mixing thoroughly using a machine.

Using these conductive paints, a coating film was formed in the same manner as in the previous example, a test piece was made, and 1. When the volume resistivity was measured, the results were as shown in Table 2.

(Types of metal components) M-1: Electrolytic copper powder, average particle size of about 10 μm M-2 Nistump copper powder (flake copper powder), average particle size of about 40 μm M-3: Brass powder (alloy ratio Cu: Zn = 90
:10), average particle diameter of about 40 μm M-4: Brass powder (alloy ratio Ou:Zn=70:30)
, average particle size of about 40 μm (resin component type) R-4: Toluene-methyl isobutyl ketone (50150 Weight ratio) Mixed solvent solution (resin concentration 20% by weight).

(Types of phosphite esters) P-9: HBP (Hydrogenated bisphenol A manufactured by Johoku Kagaku Co., Ltd.)
Phosphite polymer) P-10: JPP3300 (bisphenol octapentaerythritol phosphite manufactured by Johoku Kagaku Co., Ltd.) JPP31 in P-1 (dinonylphenyl pentaerythritol diphosphite manufactured by Johoku Kagaku Co., Ltd.) p-12:, rA805C Johoku Kagaku Co., Ltd. [Tetra(tridecyl)-4,4'-isopropylidene diphenyl diphosphite manufactured by Kagaku Co., Ltd.] P-13 Nidiphenyl mono (tridecyl) phosphite p-14: Jp260 (Diphenyl hydrogen phosphite manufactured by Johoku Kagaku Co., Ltd.)

Claims (1)

[Scope of Claims] 1. A conductive paint comprising a phosphite ester contained in a paint composition mainly consisting of a copper or copper alloy powder and a resin component. 2. A copper or copper alloy powder. The conductive paint 3 according to claim 1, wherein the blending ratio of the resin component is 5 to 50 parts by weight to 50 to 95 parts by weight, the total amount of ffil or copper alloy powder and the resin component is 100 The conductive paint according to claim 1, in which the proportion of phosphites is 0.1 to 10 parts by weight per part by weight.