JPS59102953A - Electrically conductive synthetic resin composition - Google Patents

Abstract

PURPOSE:To provide a composition imparted with excellent electrical conductivity and high shielding capability of electromagnetic wave, and suitable as the casing of electronic apparatus, economically without lowering the physical properties and formability, applying metallic film to the surface of small pieces of synthetic resin by electroless plating, and using the pieces as a filter for the composition. CONSTITUTION:The objective synthetic resin composition contains a filler comprising small pieces of a synthetic resin applied with metallic film (e.g. silver, copper, nickel, cobalt, copper-nickel alloy, nicke-cobalt alloy, nickel-iron alloy, etc.) by electroless plating. The maximum dimension of the piece is preferably 0.01-3mm. for particle, 1-3mm. for flake, and 0.01-1mm. in diameter and 0.5- 1mm. in length for fiber, and pieces having high aspect ratio are used. The thickness of the metallic film is preferably 1-3microns. The amount of the filler is >=10% based on the base resin, and the resin constituting the piece is selected to have higher heat resistant temperature than the base resin.

Description

[Detailed description of the invention] The present invention relates to a method and a synthetic resin composition obtained by adding the same.

With the recent rapid development of computer equipment and other electronic devices that apply dental technology, interference caused by unnecessary electromagnetic waves emitted from these devices to the outside is becoming a serious social problem. As is well known, the above-mentioned electronic equipment has penetrated into every corner of human society, supported by the development of circuit elements such as semiconductors, their large-scale integration, and advances in backing technology.

The high-frequency pulses emitted during operation of these commercial equipment interfere with each other and cause malfunctions.
2) General public use of receivers, radio communication equipment, audio equipment, etc. 19 "City R Installation I] Harm to LJ, so-called electromagnetic wave pollution, a new pollution +J, l cause is born. I'm trying to make it happen.

In the past, various methods have been proposed to overcome such serious f)E magnetic wave disturbances (, -), but at present there are only a few methods that can be used to overcome the source of the magnetic waves. The only practical method is to electrically shield the

The purpose of the present invention is to provide an improved manufacturing method for conductive fillers that are added to synthetic resins, synthetic rubbers, etc. for the purpose of electromagnetic shielding, which are conveniently used in the outer casings of electrical equipment. It is about providing.

Conventionally proposed methods for applying electromagnetic shielding include ■) methods that form a conductive film on the external surface of a plus-sealed molded product, such as zinc solvent, conductive coating containing metal particles such as copper or nickel; Vacuum deposition, plating, Nupanotalink, etc. can be mentioned. 2) A conductive filler is mixed into the molding material, and the filler includes carbon black, metal flakes, fibers, metal powder, carbon fiber, metallized glass, etc. Can be mentioned.

Various shortcomings have been pointed out in these conventional methods, and no definitive practical shielding method has yet been found. For example, the zinc packaging method 1 has an excellent shielding effect, but requires expensive equipment (DLL), and conductive coating requires less expensive equipment, but the cost of coating 1 is high.

11su (suC4<1.-j in the song]・4, knee kel,
In the No.
J's 1, me 1 kiuHihi] There is a limit on month A.

White letters M2!
Juice 1) f'horn is kaho~) ``i, evening is Kotsuto Ante 9 Luka J!'i', lLl'l: UIKgu, jN] Ha, 1 Tsuta'' ya total i74 judgment (1 , medium', 'R in p
>61 oxidation K J: Le Yaichi 1'1) Low 1・, -y-
> -y, -t-'J'y l, l-1-:lt
y) B”y, 2r, Rika I] between! 11n, etc. 3. The present inventors have solved the problem of the high-level (]! I and the changes in the set material 11. 1 [, poor performance 1'↓' As a result of the inspection d-1 to solve the shortcomings of Kinuta, a metal 11 film was applied to the surface by electroless plating method, and the synthetic resin was ) 1 is added to one or more different types of base synthetic resins,
By dispersing or kneading, the combination of these 1+1
21st place 1 The 'tE magnetic wave darkening ability (, i, 1j
Headline what you can do.

By means of the 71-sized synthetic resin (la f+'i is 無'市1II'I') made of 71 images of Shin'tunka 1', a densely scorched metallic surface is formed on these surfaces. Membrane 1) Extensive heat (Isuj (11 to 1'l) and heat to all ≠ 1 ml fat, typical examples include female, urea, noramino, polyester,
Epoxy, urethane/, polyolefin, polyamide I-,
Polyimide 1-1 ABS1 Polycarbo-1-, Polystyrene, Yen 0, Tsutacryl, Fluorine-containing 71! Lyoreff f]
,I? 1. 1,1. ．． 1. ! Is there any particular restriction on the shape of the small 11 of each resin?
) "f-1 spherical shape, disk shape, beret 1-shape, thin IH shape, or fiber shape, and collection of these [11 Q lines, 4 ropes, 1□Kameji JU ,, 1st order lL,
The various shapes developed in the next step i1 can be selected as good. Konemo small j1's 1st method is the maximum iY or o, o + my ~ 30 questions, Shima 14 for external grains.
The maximum diameter is 1, Q mm to 3. Qmm,
In the case of fiber-shaped ones, B 0.0 ] nm to 1. OII
Im, length 05xm ~ l (1+m is a suitable range when used as a general electromagnetic wave shielding scoop, and in particular, fillings exhibiting a flaky, 1-shaped and fibrous shape with a large aspect ratio of 1-1) Provides an electromagnetic shielding effect.

In order to deposit a metal film on these synthetic resin small Jj, an appropriate method is selected from among various conventionally known electroless plating methods depending on the type of metal to be shielded.

Electroless plating method has different effects depending on the person.
Live 111. It consists of the steps of oxidation and plating, all of which are accomplished by simple immersion in a bath, and the method of the present invention also follows this order in principle. However, depending on the surface condition of the object to be plated, etching, tinting and sensitization may be omitted.

The electroless plating method depends on the type of reducing agent used.
Next 111i monophosphoric acid method, formalin method, human run method,
Hydrogen (1-Ho7+2 method and various improved methods are known, but any of these can be applied to water droplets, and the plating bath should contain one of the above reducing agents, f or tΦ11,
+rf lI&j Make sure that the nf bath salt of the metal to be mixed is not present, and add JT regulators, buffers, stabilizers, complexing agents, auxiliaries, etc. as required. Aqueous solution. In the case of copper, formalin, human
In the case of nickel, cobalt, and alloys, hydrazine, hypophosphorous acid sorter, and boron hydroxide are preferable, and the nJ solubility of the metals listed above is preferable.
Suitable examples of 9 are sulfates, hydrochlorides, etc. As a complexing agent, tartaric acid, citric acid, 1.:1day'Δ
, condensed phosphates, polysulfonates, ethylenecyamine, etc., low molecular weight carboxylic acid or oxycarboxylic acid, and other auxiliary agents such as ammonium sulfate, ammonium chloride, boric acid, etc. can be used.

-1- Prior to the steps described above, enotinic sensitization and activation are required as a pretreatment. Enotink has 1. In the case of the object of the present invention, it is achieved by immersing it in a mixed solution of sulfuric acid and crotic acid. Sensitization treatment is carried out to facilitate the precipitation of the activated metal in the next step, and is usually carried out by immersion in 1% chloride-pumped water solution.
The activation treatment is accomplished by immersion in an aqueous solution containing 10,000 ions of gold at 11%.

・Ream plating 1 (, l, u depending on the operating conditions and operating methods
:! t, 7 Is there no other restriction? Since the wave pattern is made of water droplets and the kimono is made of synthetic resin (small) 1, it is -. , and the specific surface [
[1f increases exponentially 1, this, y) The bath ratio expressed by the ratio of the valley surface curve of the volume of the bath (Lli and i + υ plated material) and the H of the plating film: The management of operation 1, which is applied to the gold DA precipitation 1jt during immersion, is intermediate to 115, and the Meki film p7 is directly attached to l'brip as the object of the present invention. In other words, the larger the film piece, the more the film's electric current (resistance 1) i'
, if i is low 1-shi, one can obtain a shielding effect, while (
Since it is necessary to increase the amount of metal deposited per month's medium EF and fit, the plating bath requires frequent replenishment, which is economically disadvantageous. From this point U,
(2) A plating film thickness of 1 to 3 microns is suitable for obtaining a magnetic shielding effect and being economical.

In the case of electroless removal of small pieces of synthetic resin, the first step is to contaminate the culm with the bath liquid from the first stage to the second stage. In order to prevent this, after completing the treatment at each stage, thoroughly wash with water by the usual method, and if necessary, use the pressure offshore filtration method, centrifugal filtration method, filtration method, etc. The washing liquid is removed as much as possible and the treated material is transferred to the next stage. The plating conditions and bath management 'η other than these special notes are based on 71 conditions.Metals can be manufactured using the 3° electroless plating method, which can be carried out one by one by following the previously proposed procedures. The base resin, which can be considered as the addition of the resin 11 for forming a film, is curable, heat-curable, heat-curable,
,! ! Covers all of the 'El characteristics, as a representative example) 1 no-
Le, FuGq polynis-al, urea, ebon, polyurethane, polyamide 1-, polyimide 1-, polyolefzuno, l' 111 'l', yen・1. ′
1. '・11+man, polyacrylonyl l-lyl, J Jiaohi'
, polycarbonate, polystyrene, methacrylic, polyacetal, fluorine-containing polyolefin, phosphoricone, and composite resins thereof. When using the coating resin 11 as an electromagnetic shielding material, the desired base resin is molded into the object 1) By the same conventional means as mixing the ordinary filling material 1 into II, It is sufficient to simply add, disperse or knead. In addition to being simply added to base resins and expedited, it can also be used as a material for composite materials such as SMC' or as a filler for paints.

Generally, the heat distortion temperature of the base resin to be added is 75
If the thermal temperature of the resin particles is higher than that of the resin particles, the two resins will melt into each other during the kneading operation, and at the same time the metal film on the surface of the small resin will become B), and the resulting blend will be dissolved in the resin. It becomes fine particles and is evenly dispersed. On the other hand, if the heat resistance temperature of the resin pieces is high, the coated pieces will be dispersed in the base resin while maintaining their original shape within a certain temperature range.31 The combination of resins due to the difference in heat resistance between the two is (It can be selected arbitrarily depending on the purpose, but except for special cases, generally speaking, by dissolving a different type of resin, 4'\1\1\1 of the base resin is lost and small The metal film of j11- is destroyed and the fine r1:
1 Tr! As a result, the cross-linking effect is impaired, resulting in a low electromagnetic shielding ability with an IQ of 11t! Due to +-11,
The base resin has high heat resistance and quality.It is preferable to select IJ' + resin. Various resins such as polyethylene, polystyrene, △ToS, and Mekkryl M were used, and phenol,
Resins such as polyester, epoxy, polyurethane', polyamide, polyimide 1-', polycarbonyl-1I'PO, and polyacetal can be mentioned as general selection criteria, but of course both resins can be used as necessary. It is also possible to choose from 1. - distribution -. When applying a metal coating to a small j1 of resin with higher heat resistance and uniformly dispersing it in the target base resin, I? It has an electromagnetic shielding ability that can exceed f:I'':, L, and at the same time it also has the function of reinforcing the material and improving the quality.Ordinary synthetic resin molded products have the following properties: In general, Krass wool or inorganic powder is added, but by adding the electromagnetic shielding paulownia according to the present invention and OL use, it is even more effective in April modification and 0/light IIF. It is possible to improve the

The addition ratio of wood to synthetic resin, etc., should be at least about 10% (j), so that the electromagnetic shielding effect for normal purposes can be sufficiently obtained. Since only the metal is deposited on the film, there is no heavy 4:A month seen in the use of conventional metal paratars, and there is almost no change in the monthly yield per volume of i4i. In addition, it is easy to dismiss because it does not cause the sedimentation separation that occurs when metal balata is added to liquid resin.

Honesty! (According to
There is no need for large-scale equipment found in conductive coating and metal melting, and the intended purpose can be fully achieved with ordinary small-scale electroless plating equipment.

In general, the electromagnetic wave shielding effect (S l>) of a material is expressed by the following formula 8%. ), and it is considered practical if the SIE value is 30 to 40c+b. According to this formula, the frequency l QMITz ~ l GHz (7
) It can be seen that a volume resistivity of lOΩ·rmpJ, l-' is required for practical use in the range.

Adding 10 to 40 parts by weight of the metal-coated small JA resin obtained by the method of the present invention to 100 parts by weight of the synthetic resin;
The volume specific resistivity of the molded product obtained by kneading is 10-2
~10'Ω·cm, and it was confirmed that the electromagnetic wave shielding material was sufficiently covered.

This will be specifically explained below using examples.

Example 1 Particulate AI with an average particle size of 50 microns; Resin 50F was sequentially treated with a mixture of 60% sulfuric acid and 2% chromic anhydride, washed with water, sensitized with 1% tin chloride, washed with water, and washed with 0.05% tin chloride.
The product activated with 01% parachloride was immersed in a plating bath 1r having the following composition at 25'C for 30 minutes and gently stirred.

Plating bath composition Copper nitrate 0.05 mol/r Thorium tartrate 01 Caustic soda
05 // formaldehyde
10 pH 11.5 (by hydrochloric acid) After completion of plating, washing with water and drying resulted in a copper plating film having a ridged metallic luster on the surface of each particle of At:3S resin.

The volume specific resistivity of the molded product obtained by heating and kneading 20 parts by weight of this treated product with 100 parts by weight of /\IIs resin base material according to a conventional method is 127Ω·α, which is sufficient? +・It was confirmed that it can be used for magnetic shielding purposes.

Example 2 A fibrous polycarbonate with a diameter of 20 microns and a length of 3M 1-resin 50 y was sequentially pretreated with isopropyl alcohol, washed with water, and treated with a mixture of 60% sulfuric acid and 2% chromic anhydride, washed with water, and 1% Sensitivity with stannous chloride and activation with 0.001% palladium chloride were applied to the plating bath 1e with the following composition.
Soak at C for 30 minutes and stir gently.

Plating bath composition Di, Kel sulfate 01 mol/e hydrazine
10 1-lium tartrate
0.1 //匡D 'I'Δ 2Na
O,05'/■Old 11.0 (1
As a result of washing with water and drying after completing the plating (according to υ, 0[]), a Nino Kermeggi film with a clear metallic luster was obtained on the polycarbonate 1 - fibrous surface.

The volume specific resistivity of the molded product obtained by heating and kneading 15 parts by weight of this product into Δl'' (S resin) according to a conventional method is 0.3 parts by weight.
It was confirmed that the resistance was 8Ω・m and that it could be used for electromagnetic shielding purposes.

Example 3 Thickness 50 microns, 2 questions and 3 questions in the vertical and horizontal directions, respectively
Thin J42OF of polypropylene of mm thickness was sequentially treated with a mixture of 60% sulfuric acid and 5% chromic anhydride, washed with water, and washed with water.
% stannous chloride, washed with water, and activated with 0.01% palladium chloride, the plate was immersed in a plating bath 1e having the following composition at 70C for 20 minutes, and then gently tf, tid, and so on.

Plating bath composition Dinogel sulfate 01 mol/f Sodium diphosphate 1. 0,2 // Sodium citrate J, 0,2 // Ammonium sulfate J-,
Q, 5 // [Old 100 After completion of plating (with ammonia), washing with water and drying resulted in a Niacel film having a clear metallic luster on the surface of the thin polypropylene j1.

The Oat part of the treated product I was mixed with 100 tonne parts of epoxy resin (Cy-206, manufactured by Chiha Co., Ltd.) according to the usual method, along with a 20Φ meter part of hydrated alumina with an average particle size of 35 microns. After kneading, hardening agent (Ill-1951
, manufactured by Chiha t1-) and cured by adding
The volume specific resistivity of the body was 341Ω·CM, and it was confirmed that it could be used for -1° min.71 magnetic shielding purposes.

Example 4 Polyester polyol-v (Mo 618, Shell Chemical)
and isocyanun-1-(karate-1-30, shelled'/);
Sensitization III with 1% tinnous chloride: (IS,
Washed with water and treated with 0.01% palladium chloride, then immersed in N-bath 1e for 15 minutes at 6.0°C and gently stirred. 3
, plating bath composition 1i4e acid dinokel 0.
08 mol/ r copper sulfate 0.02 // nextrnr phosphoric acid I-liul, 02 〃citric acid-noturiul, 03〃I+ll
After completion of plating (with caustic soda), washing with water and drying resulted in a copper-nickel alloy plating film having a bright metallic luster on the inner surface of each cell of the polyurethane foam.

The volume specific resistivity of the molded product obtained by heating and kneading 15 parts of this treated material according to a conventional method into 100 parts of general purpose 11 mm styrene is 074 Ω, which is sufficient for electromagnetic shielding purposes. It was confirmed that the food could be served.

Examples 5 to 7 Using the resin stopper 11 of the plating 11 shown in the table, the plating bath, and the base resin to be added, plating and resin stopper 1 were carried out in the same manner as in Examples 1 to 4. The results of the measurement of the specific volume resistivity of 100% of the total resistivity are summarized below, and it was confirmed that both of them can be used for both electromagnetic and direct applications in 1' minutes.

Claims (2)

[Claims] (1) An electrically conductive synthetic resin composition, characterized in that a small piece of synthetic resin is applied as a filler by applying an osmanthus-like film on the surface by the 1 hour 1 hour barley method. (2) Metallic haze 8R1 copper, nickel, cobal
-1i-nickel alloy, nickel-coba) v1゛ alloy,
The conductive synthetic resin composition according to claim 1, which is a nickel-iron alloy.