JPS59182819A - Electrically conductive molding material - Google Patents

Abstract

PURPOSE:The titled molding material, consisting of master pellets obtained by using an electrically conductive filler having a carbon layer and a synthetic resin layer formed on the surface of metallic fibers and natural pellets, having improved mechanical strength and electromagnetic wave shielding effect, and containing the uniformly dispersed filler. CONSTITUTION:A molding material obtained by incorporating one pts.wt. master pellets 12 prepared by forming a carbon layer 2 and synthetic resin layer 3, preferably (modified) polystyrene resin, on the surfaces of metal fibers 1, preferably copper fibers, collecting the resultant electrically conductive filler into a bundle 10, integrating the bundle 10 with a synthetic resin layer 11, and cutting the integrated bundle 10 with preferably 1-20pts.wt. natural pellets, preferably forming a blend polymer with the synthetic resin layer 3 of the master pellets 12 such as (modified) polystyrene resin.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a conductive molding material in which the conductive filling side can be uniformly dispersed without reducing the strength of the synthetic resin and has a large electromagnetic wave shielding effect.

[Technical Background of the Invention and its Problems] In recent years, in order to protect electronic circuits from external interference radio waves and to prevent unnecessary radio waves generated from transmitting circuits from leaking to the outside, electronic It is required that the body be made of electromagnetic shielding material. Examples of such electromagnetic wave shielding materials include metals and conductive synthetic resins, but while the former metals have excellent electromagnetic wave velocity tIk effects, they are heavy, 1[, pentavalent, and have poor workability, etc. Due to these drawbacks, the use of conductive synthetic resins is becoming mainstream.

Method C of imparting conductivity to synthetic resin is
After molding the resin, a conductive paint is applied to the surface. There is an internal addition method in which a conductive filler is added to the powder.

The former method of forming and covering a conductive layer on the surface of a synthetic resin has the drawback of increasing the number of steps, resulting in poor 111 productivity, and the fact that the conductive layer peels off when used between resins, so we are looking forward to the latter internal addition method. has been received.

However, the latter internal addition method also had the following problems.

In order to have the desired electromagnetic shielding effect (J,
It is necessary to mix a large amount of conductive filler such as carhonya metal, which results in poor dispersion and a reduction in the mechanical strength of the molded product. Furthermore, there was a problem in that the entire length of the platform was filled with synthetic resin, which deteriorated the synthetic resin.

The reality is that it has not been possible to obtain an FE fi molding material that has a large electromagnetic shielding effect, can be mixed uniformly with synthetic resin, and does not reduce or deteriorate the strength of the synthetic resin.

[Objective of the Invention] The present invention has been made to address these problems, and it is possible to uniformly disperse a conductive filler in a synthetic resin, and to create a conductive material that has high mechanical strength and a large electromagnetic wave shielding effect. The purpose is to provide molding materials.

[Summary of the Invention] As a result of intensive research to achieve the above-mentioned object, it was discovered that the object could be achieved by using Master Pellet 1~ and J Chicoral Pellet as the main ingredients. .

That is, the conductive molding material of the present invention mainly consists of master pellets 1-, which use a conductive filler made by forming a synthetic resin layer on the surface of metal fibers having a carbon layer, and natural pellets. It is a conductive molding material characterized by the following.

The conductive A1 molding + A material of the present invention will be further explained below with reference to the drawings.

FIG. 1 shows a cross section of a conductive ↑1 filling cell used in the present invention. A carbon layer 2 is formed on the surface of the metal fiber 1,
Furthermore, a synthetic resin layer 3 is formed on the surface of this carbon layer 2. As the metal fiber, ffil, nickel, aluminum, etc. are used.

The synthetic resin used to cover the metal edge Iff may be the same type as the synthetic resin 1j; It is preferable that the third synthetic 4frl fat has a reinforcing effect, that is, a blended polymer. For example, in the case of 1:1 styrene polymer molded articles, good results can be obtained by using polyphenylene oxylate resin N17, polybutadiene resin, polycarbonate 1-6'J resin, etc. By doing this, the third synthetic resin formed at the interface has a reinforcing effect, and the properties of the molded product are improved. FIG. 2 shows a longitudinal sectional view of the conductor plate 1 formed using the conductive filling 4 shown in FIG.

Eleven long edges of the conductive filler shown in FIG. 1 are bundled and integrated with a synthetic resin layer to form a master pellet. Fibrous filling (Δ is shown thick in Figure 2, but in reality it is thin and there are many fibers.

The natural beret 1 used in the present invention is selected from a synthetic resin that forms a blended polymer as described above. General 7” plastic 1! For example, in injection molding of polystyrene resin, it is preferable that 1 to 20 layers of natural pellets (polystyrene) are combined in the most raw part to one part of the raw material of the master pellet.

The method for manufacturing master pellets will be explained using FIG. 3. A long fibrous electrically conductive filling layer having a carbon layer 2 and a synthetic resin layer 3 shown in FIG. 1 is bundled to form a filling material. The bundled conductive filler 4 is passed through a tie 6 of an extruder 5, and the conductive filler 4 bundled with a synthetic resin is coated and molded 7, and further cut 8 to form pellets 9. FIG. 4 shows an enlarged sketch of pellets 9, in which the bundled conductive fillers 1o were coated with a synthetic resin 11 to form master pellets 1 to 12.

[Embodiment 1 of the invention Next, embodiments of the present invention will be described.

A carbon layer with a thickness of about 1 μm is formed on the surface of a long copper fiber with a diameter of about 50 μm, which is made of polystyrene-modified polyphenylene A.
Killyid resin was dip-coated onto A0.
The conductive filler thus obtained is bundled and integrated with a synthetic resin coating to have a diameter of about 2...nl and a length of about 5.
The pellets cut into mm were designated as master pellets.

Conductive molding 1 by mechanically mixing 9 volumes of polystyrene plastic pellets for 1 volume of this master pellet.
The Δ family was produced. B using the obtained molded ablation 31
"The electromagnetic shielding effect of the 1C8 molded product was 5 (40d3 for IOMH7). The conductive filler was uniformly dispersed in the molded product, and the molded product had a conductive filler uniformly dispersed. No decrease in strength or deterioration was observed.

[Effects of the Invention] As explained above, since the conductive molded feed of the present invention uses metal fibers coated with carphone layer C, the electromagnetic wave shielding effect is very large.Moreover, the outermost layer of the conductive filler is Since the base material synthetic resin has good affinity with the synthetic resin and is easy to form a blend polymer, it can be uniformly dispersed in the synthetic resin to produce synthetic resin molded products with high strength and no deterioration. I can do it.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of the conductive filler used in the present invention, Figure 2 is a cross-sectional view of the conductive filler used in the present invention.
The figure is a longitudinal sectional view of the master pellet, FIG. 3 is a diagram showing a method for manufacturing master pellets 1 to 1 used in the present invention, and FIG. 4 is an enlarged sketch of the master pellet. 1... Metal fiber, 2... Carbon layer, 3...
Synthetic resin layer, 4, 10... bundled conductive filler,
5... Extruder, 6... Dice, 7.11...
Synthetic resin coating, 8... Cutting, 9, 12.
...Master pellet.

Claims (1)

[Claims] 1. A master pellet using a conductive filling material formed by forming a synthetic resin layer on the surface of a metal fiber that holds a carbon layer, and natural pellets 1 to 1 as main components. conductive molding material. 2. One knot to the master is made by forming a synthetic resin layer on the surface of a bundle of conductive Tsukuji-filled moons in the form of long fibers. Conductive I11 molding monthly rate as described in range 1. 3 The synthetic resin layer of the master pellet is polystyrene or borisdyrene modified resin, and the metal fiber is j: Naha Il.
The conductive molding material according to item 1 or 2 of the scope of the crystallization request b21, characterized in that it is natural pellets 111 boris dyrene or boris dyrene modified resin Berets 1-. 4. The conductive molding material according to any one of Items 1 to 3 of Patent '[Claim Il] 1, wherein the synthetic resin layer of the master pellet and the synthetic resin of the natural pellet form a blend polymer. 5. The conductive molding material according to any one of claims 1 to 4, wherein the metal fiber is copper 51if111.