JPH0417215B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an FRP with electromagnetic shielding effect.
It's about the product.

Many ICs and LSIs are used in computer equipment, electronic games, TV games, electronic cash registers, switching power supplies, word processors, digital clocks, calculators, and other electronic devices that apply digital technology. The electromagnetic waves emit electromagnetic waves, which cause electromagnetic interference that adversely affects surrounding televisions, radios, stereos, and other peripheral equipment, such as noise, deterioration of images, and generation of abnormal signals. For this reason, regulations have begun to be implemented in the United States and West Germany to shield electromagnetic waves emitted from electronic devices that apply digital technology, such as computer equipment.

In order to shield the electromagnetic waves emitted from the above-mentioned electronic devices, it is necessary to encase the electronic devices in a case made of a material that is a good conductor and is opaque to electromagnetic waves, such as metal or conductive plastic. It is most practical to store it in Among these, electrically conductive plastic casings are widely used in place of sheet metal, die-cast, and other metal casings because of their flexibility in molding, light weight, corrosion resistance, sound absorption, and excellent mass production. There is a tendency to Methods for imparting electrical conductivity to such a plastic housing include a method of forming a zinc film on the plastic surface by zinc spraying, a method of applying a conductive paint to form a conductive film, a method of pasting a conductive foil, A method of forming a conductive coating by vacuum evaporation, sputtering, ion plating, plating, etc., or adding carbon fiber, metal fiber, carbon powder, metal powder, etc. to the plastic.
Examples include methods of adding metal flakes, metal-coated glass fibers, and metal-coated glass powder. Coating the plastic surface with the above-mentioned zinc spraying, conductive paint, etc. involves molding the plastic into a predetermined shape, then surface-treating the molded surface, and then applying the coating, making it difficult to mass-produce.
There are disadvantages that it is time consuming and labor intensive, resulting in high costs, and that the coated film has poor corrosion resistance and adhesion. On the other hand, the method of mixing conductive powder, flakes, fibers, etc.
Since it is only necessary to mix these into plastic and mold it, it has the advantage of being excellent in mass production, requiring little labor and time, and having excellent corrosion resistance. Among them, the method using metal-coated fibers can provide conductivity and reinforcing effects at the same time, and
Since it is molded using a method similar to that of FRP, it is easy to mass produce, requires less time and effort, and makes it easy to obtain a plastic casing with uniform conductivity and electromagnetic shielding effect. Among such metal-coated fibers, what is known as metal-coated glass fiber was produced by immersing the glass fiber in a molten aluminum bath to form an A1 film on the surface of the glass fiber. However, this method
The A1 film peeled off easily and the manufacturing cost was high.

The present invention provides a metal-coated glass fiber that does not have such drawbacks, is easy to manufacture, is low in cost, and has a high-quality electromagnetic wave shielding effect that has excellent adhesion of the metal film to the glass fiber and is difficult to peel off.
We also use FRP products that have an electromagnetic shielding effect, and aim to provide FRP products that have an electromagnetic shielding effect.

The present invention will be explained in more detail below.

In the present invention, the conductive metal to be coated on the surface of the glass fiber is a metal that can form a coating on the surface of the glass fiber by electroless plating, or a metal that can be coated on the surface of the glass fiber by electroplating on the metal film formed on the surface by the above method. Metals that can be formed, namely Ni,
Cu, Ag, Pb, Fe, Co, P or alloys consisting of two or more of these metals, such as Cu-Ni alloy, Fe-Ni alloy (permalloy), Fe-Co alloy,
Ni-Co alloy, Ni-P alloy, Co-P alloy, etc. are selected. Among them, it is easy to form a film using the electroless plating method, and has excellent adhesion to the glass fiber surface.
Electrical properties that have sufficient chemical and physical durability and provide a sufficient electromagnetic shielding effect, such as electrical resistance of a square with a side of 10 cm, conductivity of about 10 ² to 10 ³ Ω, and transparency of 1 to 8000 Ω. Ni, Cu, with magnetic properties
Fe-Ni alloy etc. are most suitable.

In forming the metal film on the glass fiber surface, the glass fiber surface is subjected to sensitization treatment and/or activation treatment. As such a treatment, the glass fibers are generally washed with water, brought into contact with an aqueous solution of tinnous chloride, and then brought into contact with an aqueous palladium salt solution.

The method of forming the above-mentioned metal film on the surface of glass fiber requires the above-mentioned metal salt and reducing agent, as well as a complexing agent, a pH buffer, a pH adjuster, a stabilizer, or other additive components. A method of spraying or applying an electroless metal plating solution added accordingly to the surface of the glass fiber, or immersing the glass fiber in such a plating solution, and forming the above metal film on the surface of the glass fiber by a reduction reaction, or the method described above. Complexing agent, pH buffering agent,
An electroless metal plating solution containing a pH adjuster and other desired additives as necessary and a solution containing a reducing agent and a stabilizer are sprayed on the glass fiber surface almost simultaneously to cause a reduction reaction on the glass fiber surface. The method of forming the metal film described above is adopted.

Examples of metal salts used in the electroless metal plating solution in the present invention include inorganic or organic acids such as nickel chloride, nickel sulfate, nickel acetate, nickel bromide, and nickel iodide in the case of forming an N1 film. Water-soluble nickel salts or a mixture of at least two of these are used, and Cu
In the case of film formation, water-soluble copper salts of inorganic or organic acids, such as copper nitrate, copper sulfate, and copper acetate, or a mixture of at least two of these are used;
Metal salts such as those described above are also used when forming Ag films, Fe films, Pb films, etc. Further, when forming an alloy film, the above-mentioned metal salts of the metals constituting the alloy are used in combination. Usually, these salts are used in the form of an aqueous solution, but in some cases, they can also be used in the form of an organic solvent or a solution using an organic solvent and water.

In addition, the metal salt solution contains an alkalinity-imparting agent to adjust the pH to the desired value and a complexing agent such as Rothsiel's salt, EDTA, etc. to facilitate the reduction reaction.
Sodium citrate, sodium glyconate, etc. are added, and malic acid, boric acid, etc. are added as pH buffering agents. As reducing agents, stabilizers such as formalin, sodium hypophosphite, sodium borohydride, hydrazine, hydrazine sulfate, glyoxal, dimethylamine borane, methylamine borazane, hydrosulfide, and diethyl borazane were added. are used as representative items. Furthermore, desired additional components can be added as necessary.

In the present invention, the thickness of the metal film formed on the surface of the glass fiber is selected such that a desired electromagnetic shielding property can be obtained. For example 0.1 μm ~
A film thickness of 100 μm is optimal. The film thickness is adjusted by adjusting the temperature of the electroless metal plating solution, the metal salt concentration, the electroless plating treatment time, the number of times, etc.

In the present invention, the metal film formed on the surface of the glass fiber may be a single layer of the above metal or alloy, or may be a multilayer combination of two or more metals or alloys.

Further, on the surface of the metal film formed by electroless plating, a metal film or alloy film of the same or different type can be further formed by electroplating using the metal film as an electrode. By using such a method, the thickness of the metal film can be increased and the desired conductivity and durability can be adjusted.

The glass fiber in the present invention refers to various types of glass fiber, such as cloth, roving, chopped strand, chopped strand mat, yarn, roving, etc.
Cloth, continuous fiber mat, etc. can be used. Among them, film-like, mat-like, and sheet-like materials such as cloth, roving cloth, chopped strand mat, and continuous fiber mat can be coated with electroless plating solution easily and easily by spraying, dipping, and various other coating methods. It can be done gracefully.

The metal-coated glass of the present invention can be used for housings, covers, etc. that have an electromagnetic wave shielding effect by forming it into a predetermined shape, pasting it inside, or inserting it into a predetermined shape. Mixed or inserted into plastic or thermosetting plastic and molded into a predetermined shape of casing, plate-shaped body, etc.
FRP products are ideal as electromagnetic shielding parts. Electromagnetic shielding using such metal-coated fibers
FRP products can be molded using the same molding method as regular FRP products, and the workability is good, and the products are also ideal for their high strength and chemical durability.

Examples of the present invention will be described below.

Example 1 Water-washed roving type glass fibers (dimensions, diameter 12-13 μm, 2000 fluor product type) were injected into an aqueous solution of stannous chloride (SnCl ₂ 2H ₂ O, 1 g/
Immersed in water 1), held for 60 seconds for sensitization treatment, washed with water, then immersed in palladium chloride aqueous solution (PdC ₂ nH ₂ O, 0.1 g/water 1),
After being activated by holding for 60 seconds, it was washed with water. This treated glass fiber is then treated with nickel sulfate.
30g/1, sodium hypophosphite 10g/1, sodium acetate 10g/1, sodium citrate 10g/1
After forming a Ni film with a thickness of 1 to 2 μm on the above glass fiber by holding it in an electroless Ni plating solution with a composition of 1 at a temperature of 70°C for 150 seconds (plating speed 80 m/hr), the following process was performed. The liquid was kept in a permalloy electroplating bath at a temperature of 50°C for 150 seconds, and the current density was 5A/
Electroplating was carried out as dm ² to form a permalloy film having a thickness of approximately 2 to 3 μm on the Ni-coated glass fibers and having a square shape of 10 cm on each side when woven in a cross-like manner and an electrical resistance of 0.01 Ω.

Liquid composition Nickel sulfate 300g / Nickel chloride 20g / Ferrous sulfate 20g / Boron 30g / As mentioned above, the metal film formed on the glass fiber surface by the electroless plating method as in the present invention is conventionally known. The adhesion strength of the film is higher than that of fused A1-coated glass fiber, and the bending strength of FRP products made using this glass fiber is also high, and the electromagnetic shielding effect is on the same level. Furthermore, by using the electroless plating method, the electroless plating method, and the electroplating method, it is easy to coat the glass fiber surface with a metal film.
The advantages are that mass production is easy and costs can be reduced.

Claims (1)

[Claims] 1 An electroless plated metal film is provided on the surface of the glass fiber, and a metal-coated glass fiber is provided as a reinforcing agent, with an electrolytically plated metal film provided on the electroless plated metal film.
For FRP products, the metal films formed by the electroless plating method include Ni film, Cu film, Co film, Fe film,
Ni-Cu alloy film, Ni-P alloy film, Co-P alloy film,
Co-Ni-P alloy film, Fe-Ni alloy film, or Fe-
Co alloy film has electromagnetic shielding effect
FRP products.