JPH0818000B2 - Method for producing epoxy resin-based low electrical resistance material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an epoxy resin-based resin suitable for use in electronic component materials (printed wiring boards, electrode materials, etc.), antistatic clothing, surface heating elements, etc. The present invention relates to a novel method for manufacturing an electric resistance material.

(Prior Art) Epoxy resin has a large mechanical strength and a large adhesive force in addition to the lightweight and inexpensive characteristics of synthetic resin,
It is well known that it is widely used as various molded products and adhesives, and recently its use is spreading to electronic component materials and the like. By the way, since epoxy resin, isocyanate resin and other synthetic resins are generally insulators,
When used for electronic parts, particularly for electrode materials and printed wiring boards, it is necessary to coat the surface of these resin molded products with a conductive metal film or a conductive paint. Moreover, since the synthetic resin is rich in electrostatic properties and easily attracts dust in the air, it is given conductivity not only in the above-mentioned electronic parts but also in the field of clothing and the like.

(Problems to be Solved by the Invention) There are electroless plating method, vacuum deposition method, sputtering method, ion plating method, coating method and the like as a method for forming a conductive coating as described above. Both require complicated steps and expensive equipment, the manufacturing cost is high, the cheap properties of the synthetic resin are offset, and the adhesion of the obtained coating is weak and the initial performance is not maintained for a long time. There was a flaw. Taking the case of electroless plating, which is most frequently used, as an example, the surface roughening process of treating the surface of the resin molded product with mixed acid, and sensitizing to adsorb tin ions on the roughened surface to increase the surface sensitivity. The process, the activating process for displacing tin ions with platinum to activate the roughened surface, and the electroless plating process for depositing the target metal using the catalytic action of platinum are required, and the labor, time and materials required. Etc. were extremely large.

Also, when a conductive coating is formed with a conductive paint (especially used for a housing with an electromagnetic shield), there is a problem such as a short circuit due to peeling due to poor adhesion. .

Further, nichrome wire is enclosed in a plastic substrate, or conductive carbon black is kneaded to form a surface heating element (for example, heating floor material, electric blanket, etc.). The product shape is naturally limited. There is also a method of obtaining a planar heating element with a tin oxide coating, but there is a drawback in that the substrate material is necessarily limited by heat treatment of 800 ° C. or higher.

The present invention has been made in view of the above, to form a copper sulfide coating film by chemical bonding on the epoxy resin surface,
It is intended to provide an effective and simple manufacturing method of an epoxy resin-based low electric resistance material which enables the above-mentioned applications and development of other new applications.

(Means for Solving Problems) The constitution of the present invention for achieving the above-mentioned object is to immerse a base material having a surface of an epoxy resin in a solution in which hydrogen sulfide is dissolved or exposed to a hydrogen sulfide gas atmosphere, Then, the base material is immersed in a copper ion-containing solution to deposit a conductive layer of copper sulfide on the resin surface of the base material, and a method for producing an epoxy resin-based low electrical resistance material is characterized. It is in.

The base material used in the method of the present invention is composed of the epoxy resin itself as described above, or is composed of another insulating material coated with the epoxy resin. The former is various molded epoxy resin products (for example, a box). Shape, plate-like or powder-grained molded product, etc., the latter is glass, plastics, ceramics,
The surface of an insulating material such as wood or fiber and a powdery primary material thereof is coated with an epoxy resin, which is appropriately selected according to the application.

The above base material is immersed in a solution in which hydrogen sulfide is dissolved or exposed to a hydrogen sulfide gas atmosphere, and 0 to 100 ° C. is applied to the base material.
After being acted for 4 to 40 minutes to chemically bond the sulfur element (S) in the structure of the resin, it is immersed in the following copper ion-containing solution.

The copper ion-containing solution is one or several kinds of salt solutions selected from a copper sulfate solution, a copper nitrate solution, a copper acetate solution, a cupric chloride solution, etc., and 1-ascorbic acid, D-xylose, formaldehyde, and sulfurous acid gas. It is prepared by mixing any one or several kinds selected from reducing agents such as
Cu ⁺ ions are mainly produced in the solution by the salt solution and the reducing agent, and the Cu ⁺ ion concentration in this solution is 0.01 mol.
/ ~ Saturation concentration is suitable, particularly 0.05-1.5 mol / is a suitable range, but is not necessarily limited to this range. Further, the pH is suitably in the acidic region of 7 or less, and particularly preferably adjusted to pH 2-5. Also,
It is also possible to use a solution in which Cu ⁺ ions are produced from a cuprous chloride solution.

In addition to the above, by adding an appropriate amount of various surfactants, additives such as propylene carbonate and ethylene glycol, it is possible to form a uniform and glossy copper sulfide film on the surface of the substrate.

(Operation) When hydrogen sulfide is applied to the base material, S is incorporated into the structure of the epoxy resin on the surface of the base material in a chemically bonded state.
This chemical reaction is represented by the following equation, respectively.

Reaction of epoxy resin with hydrogen sulfide; S incorporated in the resin structure in a chemically bonded state as described above is chemically active, and when the above-mentioned copper ion-containing solution is allowed to act on it, S and copper ions are bonded to each other, and mainly S Copper sulfide (in some cases, cupric sulfide is mixed and precipitated, but in the following, this is generically referred to as copper sulfide) is formed in clusters.

The copper sulfide thus produced is deposited on the resin surface as a stable conductive layer. This fact was clarified by the analysis of the treated product by photoelectron spectroscopy (ESCA), which revealed that copper sulfide appeared in place of the functional group of the epoxy resin. Since the chemical action of the copper ion-containing solution is a reaction between S incorporated in the resin structure and copper ions, excess copper sulfide does not precipitate in the solution,
Therefore, the solution can be used repeatedly until the copper ions are exhausted. Moreover, since the formed copper sulfide coating is chemically bonded to the resin surface, it is a very stable layer with high peel resistance.

Furthermore, by adding the additives as described above, the wettability of the epoxy resin surface is improved, the copper sulfide film is formed uniformly and the particles of the copper sulfide are uniformly fine, and the film has excellent transparency and gloss. Is formed.

The surface resistance value of the obtained treated product is 10 ¹ to 10 ⁴ Ω, and 10 ² Ω in most cases. Therefore, when applied to a material such as an electronic component material or a heating element, the required performance can be sufficiently satisfied.

(Example) Hereinafter, the present invention will be described in more detail with reference to Examples.

(Example-2) (1) Preparation of substrate: Epoxy resin [a main agent (bisphenol A type, epoxy equivalent 190) and a curing agent (polyamide resin, active hydrogen equivalent 75) are mixed in equivalent amounts on a polycarbonate plate] It was applied and cured at 120 ° C. for 10 minutes to form an epoxy resin film.

(2) Preparation of copper ion-containing solution: An equivalent amount of D-xylose was added to a 1 mol / copper nitrate solution to prepare a copper ion-containing solution.

(3) Conductivity treatment: The above substrate was immersed in a saturated hydrogen sulfide aqueous solution at 0 ° C for 10 minutes, and then immersed in the above copper ion-containing solution at 0 ° C for 10 minutes.

(4) Measurement of surface resistance value; measured value ... Takeda Riken Co., Ltd.
Manufactured by DIGITAL MULTIMETER TR-6843 Electrodes ... Copper plate Measurement method ... Placing the treated sample between the electrodes, the distance between the electrodes is 2 cm
The resistance was measured by setting the value constant and connecting both electrodes to the measuring instrument with a conductor.

 As a result, a surface resistance value of 320Ω was obtained.

(Example-3) (1) Preparation of base material; epoxy resin (Example-2) on a polycarbonate plate.
The same) was applied and cured at 120 ° C. for 60 minutes to form a film of epoxy resin.

(2) Preparation of copper ion-containing solution; same as in Example 2 (3) Conducting treatment; dipping the above base material in a saturated hydrogen sulfide aqueous solution at 20 ° C for 10 minutes, and then subjecting it to the above copper ion containing solution at 20 ° C. And soaked for 10 minutes.

(4) Measurement of surface resistance value: Measured in the same manner as in Example-2. As a result, a surface resistance value of 460Ω was obtained.

(Example-4) The difference in the appearance of the copper sulfide coating film depending on the additive was examined.

(1) Preparation of base material: Epoxy resin [main material (bisphenol A type, epoxy equivalent 190) and curing agent (polyamide type resin) are mixed in equal amounts] is applied on a glass plate, and the mixture is applied at 80 ° C. for 10 minutes. Then 12
It was cured at 0 ° C for 15 minutes to form an epoxy resin film.

(2) Preparation of Copper Ion-Containing Solution: Propylene carbonate and ethylene glycol were added to the copper ion-containing solution of Example-2 in the proportions shown in Table 1.

(3) Conductivity treatment: The above substrate was immersed in a saturated hydrogen sulfide aqueous solution at 20 ° C for 10 minutes, and then immersed in the above copper ion-containing solution at 20 ° C for 10 minutes.

(4) Measurement of surface resistance value and observation of appearance: The surface resistance value was measured in the same manner as above, and the appearance was visually compared. The results are shown in Table 1.

However, * 1 shows the ratio of the additive to the copper ion-containing solution. Further, A and B represent propylene carbonate and ethylene glycol, respectively. Furthermore, "Excellent", "Good", and "Good" in the column of the appearance of the copper sulfide coating show relative evaluation by visual observation with respect to the blank (without addition of an additive).

From the results in Table 1, it is understood that the additive improves the appearance of the copper sulfide coating.

(Adhesion test) The adhesion of the copper sulfide coating in the treated products of Examples-2 to -3 was examined.

(1) Evaluation method: 10 × 10 mm cross-cutting method.

(2) Results; Table 2 shows the results.

It is understood from Table 2 that the adhesion of the copper sulfide coating to the epoxy resin is good. Others, as mentioned above, ESCA
From the analysis result of 1., the copper sulfide coating is chemically bonded to the epoxy resin and is extremely stable.

In addition to the above examples, the same process was performed on a single plate of epoxy resin, for example, but substantially the same results as above were obtained. Similar results were also obtained when the treatment with hydrogen sulfide was performed in a hydrogen sulfide gas atmosphere.

(Effects of the Invention) As described above, the method for manufacturing the residence electrical resistance material of the present invention is
Since the base material having the surface of the epoxy resin is treated with hydrogen sulfide and then the copper ion-containing solution is allowed to act, the sulfur element and the copper which are chemically bonded to the resin structure by the hydrogen sulfide treatment are incorporated. The copper ions in the ion-containing solution are chemically bonded to form a very stable conductive film of copper sulfide on the surface of the base material. Moreover, the manufacturing procedure is extremely simple, the manufacturing cost and labor required are remarkably reduced as compared with the conventional electroless plating method and other conductive treatment methods, and the facility cost is also cheaper. Since it reacts with the sulfur element in an equivalent amount, excess copper sulfide, etc. does not precipitate, and the copper ion-containing solution can be repeatedly used as long as copper ions do not disappear, and therefore, in designing these production processes. It is also possible to automate a series of steps from hydrogen sulfide treatment to conductivity treatment. The low electric resistance material obtained by the method of the present invention maintains a low level surface resistance value due to the stable conductive coating having high adhesion of copper sulfide, and has excellent properties of the epoxy resin (especially good properties for various materials). In combination with the adhesive properties), various valuable uses that promise desired product shapes by various material selections are promised. It has remarkable effects such as ... and its industrial utility is extremely large.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical display location H01B 1/20 Z H01C 17/06 MH05B 3/14 B 7512-3K (72) Inventor Nakahira Makoto, Takiron Co., Ltd., 2-30 Azuchi-cho, Higashi-ku, Osaka City, Osaka Prefecture (56) Reference JP-A-61-40362 (JP, A) JP-A-61-273804 (JP, A)

Claims (1)

[Claims] 1. A substrate having an epoxy resin surface is immersed in a solution in which hydrogen sulfide is dissolved or exposed to a hydrogen sulfide gas atmosphere, and then the substrate is immersed in a solution containing copper ions.
Method for producing an epoxy resin-based low electrical resistance material in which a conductive layer of copper sulfide is formed on the resin surface of the base material by deposition.