JPH058528B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to electronic component materials (printed wiring boards,
The present invention relates to a novel epoxy resin-based low electrical resistance material suitable for use in electrode materials, antistatic clothing, surface heating elements, etc., and a method for producing the same. (Prior art) Epoxy resin is widely used as a material for various molded products and adhesives because it has high mechanical strength and adhesive strength in addition to being lightweight and inexpensive as a synthetic resin, and has recently been used as a material for electronic parts. As is well known, its use is becoming widespread. By the way, since epoxy resins and other synthetic resins are generally insulators, when used for electronic component-related applications, especially electrode materials and printed wiring boards, the surfaces of these resin moldings are coated with conductive metal films or other materials. Coating with conductive paint is required. Furthermore, since synthetic resins are highly chargeable and easily attract dust in the air, they are often used to impart conductivity not only to electronic components but also to clothing and other fields. (Problems to be Solved by the Invention) There are electroless plating methods, vacuum evaporation methods, sputtering methods, ion plating methods, painting methods, etc. as methods for forming the above-mentioned conductive film. All of these methods require complicated processes and expensive equipment, which increases manufacturing costs and offsets the inexpensive properties of synthetic resins.Furthermore, the resulting coatings have poor adhesion and do not maintain their initial performance for a long time. There were flaws. Taking the most frequently used electroless plating method as an example, there is a surface roughening process in which the surface of a resin molded product is treated with a mixed acid, and a sensitizing process in which tin ions are adsorbed on the roughened surface to increase the sensitivity of the surface. The process requires an activating process in which tin ions are replaced with platinum to activate the roughened surface, an electroless plating process in which the target metal is deposited using the catalytic action of platinum, and the labor, time and materials required. etc. were extremely large. Furthermore, when forming a conductive film using conductive paint (particularly used in electromagnetic shielded housings, etc.), adhesion is poor, resulting in problems such as short circuits due to peeling. Furthermore, nichrome wires are encapsulated in plastic substrates, and conductive carbon black is kneaded to make planar heating elements (for example, heating floor materials, electric blankets, etc.), but the materials used are This naturally limits the product shape. There is also a method of obtaining a planar heating element using a tin oxide film, but this method has the disadvantage that the substrate material is inevitably limited by the need for heat treatment of 800° C. or higher. The present invention has been made in view of the above, and is a novel epoxy resin that forms a copper sulfide coating tightly on the surface of the epoxy resin through chemical bonding, thereby making it possible to develop the above-mentioned and other new applications. The object of the present invention is to provide a low electrical resistance material and an effective manufacturing method thereof. (Means for Solving the Problems) The configuration of the present invention to achieve the above object is that the specific invention is made from an epoxy resin cured with a curing agent containing an amine type, a polyamine type, a polyamide type, or a polythiol type. Copper sulfide film is deposited on the surface of a base material made of a base material or an insulating material coated with an epoxy resin cured with an amine-based, polyamine-based, polyamide-based, or polythiol-based curing agent. The present invention relates to an epoxy resin-based low electrical resistance material comprising at least a base material or an insulating material made of an epoxy resin cured with a curing agent containing an amine-based, polyamine-based, polyamide-based, or polythiol-based curing agent. A mixed solution of a copper ion-containing solution and a reducing compound solution containing sulfur is applied to a base material made of an epoxy resin cured with an amine-based, polyamine-based, polyamide-based, or polythiol-based curing agent. A method for producing an epoxy resin-based low electrical resistance material, characterized in that copper sulfide is deposited on the surface of the substrate by a reduction reaction of the mixed solution. For convenience, the manufacturing method, which is the second aspect of the present invention, will be described in detail first. The base material used in the method of the present invention is made of an epoxy resin itself cured with a curing agent containing an amine type, polyamine type, polyamide type, or polythiol type as described above;
and an insulating material are coated with epoxy resin cured with the above-mentioned curing agent.
The latter is made of insulating materials such as glass, plastics, ceramics, wood, fibers, etc., and the surfaces of these powders and granules are coated with epoxy resin, depending on the application. Selected appropriately. These substrates are immersed in a mixed solution of a copper ion-containing solution and a reducing compound solution containing sulfur.
It is prepared from one or more selected from salt solutions such as copper acetate solution and copper chloride solution, and the concentration thereof is 0.01 mol/~ the respective saturated concentration (for example, if the saturated concentration of copper chloride is taken, 0.01 ~
4.9mol/) or less is suitable, especially 0.05~
A suitable range is 1.5 mol/, but it is not necessarily limited to this range. Furthermore, its PH
An acidic range of 7 or less is appropriate, and it is particularly desirable to adjust it to 2-5. In addition, the reducing compound solution used together with the copper ion-containing solution is composed of one or more compounds selected from sulfur-containing compounds such as sodium thiosulfate, sodium sulfite, and hydrogen sulfide, and the concentration of this reducing compound solution is teeth
0.05 to 1.5 mol/ is preferable, but not limited to this, and it is desirable that the amount added is approximately chemical equivalent to the above-mentioned copper ion-containing solution, but it goes without saying that it is not limited to this. Nor. The substrate may be immersed in the above mixed solution by immersing the substrate in the copper ion-containing solution and then adding the reducing compound solution, or by immersing the substrate in the reducing compound solution and then adding the copper ion-containing solution. Alternatively, both solutions may be mixed in advance and then the substrate may be immersed in the mixture.In short, it is sufficient that the substrate is immersed during the reduction reaction of both solutions. When the reaction vessel containing the copper ion-containing solution and the reducing solution and in which the substrate is immersed is heated in a hot bath at 60 to 90°C for about 10 minutes to 3 hours while stirring or shaking, the substrate is heated. On the surface of the epoxy resin, mainly cuprous sulfide (in some cases, cupric sulfide is mixed and precipitated, but hereinafter these will be collectively referred to as copper sulfide) is precipitated to form a coating. At this time, various surfactants, propylene carbonate,
If you add an appropriate amount of additives such as ethylene glycol,
A uniform and glossy copper sulfide film can be formed on the surface of the epoxy resin. (Function) As mentioned above, according to the reduction reaction of mixing a copper ion-containing solution and a reducing compound solution, when these are respectively used as a copper sulfate solution and a sodium thiosulfate solution, the following reaction mainly occurs, and 2CuSO ₄ +2Na ₂ S ₂ O ₃ + 2H ₂ O = Cu ₂ S + S + 2Na ₂ SO ₄ + 2H ₂ SO _4Copper sulfide (Cu ₂ S) precipitates and adheres to the epoxy resin surface of the base material. At this time, the copper sulfide in the precipitation process is fixed as a film on the surface of the cured epoxy resin in a chemical bond state with the functional groups on the surface of the cured epoxy resin cured by the curing agent containing the above-mentioned amine type or the like. This fact is based on the fact that when the above-mentioned treated product was analyzed by photoelectron spectroscopy (ESCA), it was confirmed that the peak associated with the functional group of the epoxy resin disappeared and the presence of copper and sulfur appeared instead. it is obvious. In addition, by adding the additives mentioned above, the wettability of the epoxy resin surface improves, a copper sulfide coating is formed uniformly, and the precipitated copper sulfide particles become uniform and fine, resulting in excellent transparency and gloss. A film is formed. The surface resistance value of the obtained processed product is 10 ¹ to 10 ⁴ Ω,
Often 10 ² Ω. Therefore, when it is suitable for electronic component materials, heating elements, etc., the required performance can be fully satisfied. (Example) The present invention will be explained in further detail with reference to Examples below. Example 1 (1) Preparation of base material; Apply an epoxy resin prepared by mixing bisphenol A type epoxy resin (epoxy equivalent: 190) and a curing agent (shown in Table 1) in equivalent amounts on a glass plate, It was cured at 80±5° C. for 5 hours to form an epoxy resin film. (2) Preparation of reaction solution: 10 ml of a 1 mol/mol copper nitrate solution and 10 ml of a 1 mol/sodium thiosulfate solution were prepared. (3) Reaction conditions: Place the above substrate into a reaction container, add the above reaction solution, and shake on a 65°C hot bath for 3 hours.
Thereafter, the base material was taken out, washed with water, and dried. (4) Measurement of surface resistance value; Measuring device…manufactured by Takeda Riken Co., Ltd., DIGITAL
MULTIMETER TR-6843 Electrode...Copper plate Measuring method...The treated sample was sandwiched between the electrodes, the distance between the electrodes was kept constant at 2 cm, and both electrodes were connected to a measuring device with a conductive wire to measure the resistance value. The results are shown in Table 1.

[Table] Example 2 (1) Preparation of base material: An epoxy resin prepared by mixing bisphenol A type epoxy resin (epoxy equivalent: 190) and a curing agent (shown in Table 2) in equivalent amounts was placed on a glass plate. It was applied and cured at 80°C for 10 minutes and then at 120°C for 15 minutes to form an epoxy resin film. (2) Preparation of reaction solution: Same as Example 1. (3) Reaction conditions: Same as Example 1. (4) Measurement of surface resistance: Measured as in Example 1. The results are shown in Table 2.

[Table] Example 3 Surface resistance values were measured when the reaction time was shortened. An epoxy resin prepared by mixing bisphenol A type epoxy resin (epoxy equivalent: 190) and a curing agent (shown in Table 3) in equivalent amounts is applied onto a glass plate, and cured at 80±5°C for 5 hours to form an epoxy resin. A resin film was formed. (2) Preparation of reaction solution; 0.2mol/copper sulfate solution adjusted to PH2 10
ml and 0.2 mol/ml of sodium thiosulfate solution were prepared. (3) Reaction conditions: The mixture was placed in a reaction vessel in the same manner as in Example 1, shaken on a 65°C hot bath for 15 minutes, taken out, washed with water and dried. (4) Measurement of surface resistance value; Measure the surface resistance value in the same manner as in Example 1,
The results are shown in Table 3.

[Table] From Tables 1, 2, and 3 of Examples 1, 2, and 3 above, the surface resistance value remains 10 even if the type of curing agent, curing conditions, and reaction conditions of the epoxy resin change. It is understood that it is on the order of ¹ to 10 ⁴ Ω. Example 4 Differences in appearance of copper sulfide coatings depending on additives were investigated. (1) Preparation of the base material; Apply an epoxy resin made by mixing equivalent amounts of bisphenol A type epoxy resin (epoxy equivalent: 190) and curing agent (polyamide resin) onto a glass plate, and heat at 80°C for 10 minutes. , then 15 at 120℃
This was cured for a few minutes to form an epoxy resin film. (2) Preparation of reaction solution; 10 ml of a 0.2 mol/mol copper sulfate solution and 10 ml of a 0.2 mol/sodium thiosulfate solution containing propylene carbonate and ethylene glycol in the proportions shown in Table 4 were prepared. (3) Reaction: Same as Example 3. (4) Measurement of surface resistance value and observation of appearance; In the same manner as above, the surface resistance value was measured and the appearance was visually compared. The results are shown in Table 4.

[Table] However, *1 indicates the ratio to the copper sulfate solution.
Further, A and B represent propene carbonate and ethylene glycol, respectively. Further, in the column for the appearance of the copper sulfide coating, Excellent, Good, and Fair indicate relative evaluations by visual observation with respect to a blank (no additives added). From the results in Table 4, it is understood that the additive improves the appearance of the copper sulfide coating. Example 5 The treated products in Example 3 were arbitrarily selected and the adhesion of the copper sulfide coating was examined. (1) Evaluation method: 10×10mm grid cross cutting method. (2) Results: The results are shown in Table 5.

[Table] It is understood from Table 5 that the adhesion of the copper sulfide coating to the epoxy resin surface is good. also,
As mentioned above, the ESCA analysis results show that this copper sulfide coating is extremely stable because it is chemically bonded to the epoxy resin. In addition to the above-mentioned examples, for example, a polycarbonate resin plate coated with epoxy resin on the surface instead of a glass plate, or a single epoxy resin plate was also treated in the same manner, but almost the same results as above were obtained. Obtained. (Effects of the Invention) As described above, the low electrical resistance material of the present invention maintains a low level of surface resistance due to the highly adhesive and stable coating of copper sulfide, and is suitable for use with various materials, especially those with excellent epoxy resins. On the other hand, combined with good adhesive properties, it promises a variety of valuable applications, making it possible to create desired product shapes through a variety of material selections. Moreover, the manufacturing method is extremely simple, as it simply involves immersing an epoxy resin base material in a reaction solution of a copper ion-containing solution and a reducing compound solution containing sulfur. Compared to the chemical treatment method, the manufacturing cost and required labor are significantly reduced, and equipment costs are also lower.

Claims (1)

[Claims] 1. An amine-based, polyamine-based, polyamide-based, or polythiol-based base material or insulating material made of an epoxy resin cured with an amine-based, polyamine-based, polyamide-based, or polythiol-based curing agent. An epoxy resin-based low electrical resistance material made by depositing and depositing a copper sulfide coating on the surface of a base material coated with an epoxy resin cured by a curing agent contained therein. 2 Epoxy cured with an amine-, polyamide-, or polythiol-containing curing agent on a base material or insulating material made of an epoxy resin cured with an amine-, polyamine-, polyamide-, or polythiol-containing curing agent A base material coated with resin is immersed in a solution containing copper ions and a reducing compound solution containing sulfur, and copper sulfide is deposited on the surface of the base material through a reduction reaction of the mixed solution. A method for producing an epoxy resin-based low electrical resistance material.