JPH10130853A - Metal plating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To firmly deposit plating metal to the smooth surface of a substrate. SOLUTION: Pretreatment and plating treatment are executed. In the pretreatment, a mat material 2 is formed on a substrate 1, and the fine particles of the applied mat material are deposited to the surface of the substrate 1 to form raggedness, by which the adsorptivity of a plating catalyst can be improved. In the plating treatment, plating metallic film 3 obtained by electroless plating is formed on the surface of the substrate 1. The plating metallic film 3 is uniformly formed on the substrate 1 via the mat materials 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal coating method for coating a surface of a substrate which is non-conductive and on which a plating metal is not easily applied, with a plating metal film.

[0002]

2. Description of the Related Art A technique for imparting conductivity to a non-conductive substrate, for example, a synthetic resin foam or a synthetic resin fiber product, is used for manufacturing an electromagnetic wave shielding material. Conventionally, as a method for imparting conductivity to a non-conductive substrate, an electroless plating method, a sputtering method, a metal deposition method, and the like are known.

However, the sputtering method and the metal deposition method require special equipment including a deaerator since they are performed in a high vacuum. In this regard, the electroless plating method uses
The substrate can be made conductive simply by immersing it in the plating bath.

[0004] Electroless plating (chemical plating) is a method in which metal ions in a solution are chemically reduced to deposit deposited metal on a substrate. Etching, degreasing, sensitization,
Processing such as activation is performed.

[0005] For example, as an etching treatment, a method of forming a pretreatment coating film containing a large amount of metal particles in an organic binder on the surface of a base material, performing an alkali etching treatment, and then performing ordinary electroless plating is disclosed in a published patent publication. 1987-500
No. 344.

Japanese Patent Application Laid-Open No. 7-42072 discloses a method of forming a metal film on the surface of a fibrous structure composed of polyester fibers by electroless plating, based on the weight of the fibrous structure prior to electroless plating. 0.0
100% boiling point, containing 1-5% sodium hydroxide
After refining and degreasing the fibrous structure using an organic solvent composed of at least one set of azeotropic mixtures at a temperature of not more than 0 ° C., the fiber structure is treated with a solution of a urethane-based resin dissolved in the same kind of organic solvent as described above. A metal coating processing method for a polyester fiber structure is proposed, and according to this method, the effect of forming a uniform and good-adhesion metal film on the surface of the polyester fiber structure is emphasized.

[0006]

According to the method described in the above-mentioned Japanese Patent Publication No. 62-500344, problems such as metal spillage due to waste liquid and deterioration of the working environment tend to occur.
Further, since the surface of the substrate is directly damaged to roughen the surface, problems such as deterioration of the physical properties of the substrate occur.

The method disclosed in Japanese Patent Application Laid-Open No. 7-42072 is
It is an attempt to use a urethane-based resin with excellent adhesion for the adhesion of the metal film.However, since the urethane-based resin adheres to the rough surface formed on the fiber surface, when compared with the conventional method, However, this is only a difference whether the metal film is backed by a urethane resin or not.After all, this prior example also forms a rough surface by scratching the surface of the base material surface by etching etc., and using this rough surface This is within the range of the concept of making the metal film adhere.

It is an object of the present invention to provide a metal coating method for fixing a metal film by electroless plating without damaging the substrate surface.

[0009]

To achieve the above object, a metal coating method according to the present invention comprises a pretreatment and a plating process,
The pre-treatment is a treatment for applying fine particles of the mat material to the base material, and the plating treatment is to perform electroless plating on the pre-treated base material and bury the fine particles of the mat material applied to the base material. This is a process of forming a plated metal film by using

The pretreatment is a process of applying an emulsion containing a mat material and an adhesive to a substrate, drying the substrate, and fixing the mat material to the substrate.

The fine particles of the matting material adhere to the base material to form irregularities on the surface of the base material, thereby improving the adsorption of the plating catalyst in the plating process.

[0012]

Embodiments of the present invention will be described below. In FIG. 1A, according to the present invention, an inorganic mat material 2 is applied to a base material 1 as a pretreatment, and then electroless plating is performed as a plating process, and as shown in FIG. To form a plated metal film 3 on the substrate 1.

In the present invention, the base material 1 is a material to be processed into, for example, an electromagnetic wave shielding material, a conductive material, an antistatic material, and the like. Although a body block or the like is used, a polyolefin resin or the like on which a plated metal is hardly applied can also be used as a base material. Such a base material does not require any special treatment such as an etching treatment on the base material surface, and thus does not cause a problem of waste liquid such as strong alkali.

The mat material is a matting agent or a polishing agent. The matting agent is an agent added to a fiber or a rayon to be applied to the surface during spinning to reduce the gloss of the rayon, or added to a paint or varnish to give a matte matte finish to the material surface.

[0015] Polishing agents are powders, liquids, semi-liquids used for smoothing, protecting and decorating the surface of leather or wood when finishing the surface of leather or wood, or glue added when polishing fibers. Materials and fillers.

In the present invention, the mat material comprises a matting agent,
It is used as a polishing agent and takes the form of fine particles. For example, silicon-based compounds such as silicon dioxide, carbon powder, activated carbon powder, metal powder, synthetic resin powder, and the like can be used. The average diameter of the fine particles is preferably about 10 to 200 μm, more preferably about 30 μm.
８０80 μm. The fine particles of the matting agent adhere to the substrate and form irregularities on the surface of the substrate. If the particle size of the fine particles of the matting agent is less than 10 μm, the matting agent may be buried in an adhesive for adhering to the substrate, and the adhering effect may be lost. On the other hand, if the particle size exceeds 200 μm, the irregularities on the surface of the base material become large, and there is a possibility that the plating layer may be cracked or missing.

In order to attach this mat material to a substrate,
Disperse in the adhesive solution. As the adhesive, an emulsion type adhesive such as an acrylic type, a urethane type or an epoxy type is preferable in view of workability. The resin content of these adhesives is appropriately selected depending on the adhesive used and the application method. However, if the amount is too small, the adhesive strength between the mat material and the base material becomes insufficient, and the mat material may be lost during the plating process. And the plating adhesion becomes non-uniform. Further, if the viscosity of the adhesive is too high due to too much resin, it is difficult to uniformly apply the adhesive to the base material, and it is difficult to uniformly disperse the mat material in the adhesive, which causes plating failure. there is a possibility.

The amount of the mat material added to the adhesive is 0.1 to 5% based on the adhesive, and more preferably,
Add about 0.5-1%.

The amount of the mat material adhered to the substrate depends on the type and shape of the substrate, but may be about 1.0 to 10 g / m ² as a solid content after drying. The amount of this adhesion is 10 g
If it exceeds / m ² , in the plating process, the adsorption of the catalyst increases, the aging of the plating solution is accelerated, and the formed plating layer is liable to be chipped or cracked. On the other hand, when the adhesion amount is 1.0 g / m ² or less, plating unevenness easily occurs due to insufficient adsorption of the catalyst.

The pretreatment is a process of applying a mat material to a substrate, or applying fine particles of the mat material to the substrate by a method such as dipping or spraying.

The method of electroless plating as the plating treatment is not particularly limited, and any of the electroless plating methods conventionally used for metal plating of synthetic resins and synthetic fibers can be used. For example, in the case of electroless nickel plating, a sensitizing-activating method, a catalizing-activating method, or the like is used as an activation process of the electroless nickel plating. Electroless plating is performed by immersion in a plating bath using a water-soluble nickel salt such as nickel chloride, nickel formate, and nickel acetate. As a reducing agent for electroless nickel plating, sodium hypophosphite, dimethylamine borane, or sodium borohydride is used. The metal film 3 is coated on the substrate 1 by covering the mat material adhered to the substrate structure by the electroless plating. Is formed.

[0022]

Examples of the present invention will be described below.

Woven cloth (polyester taffeta, thread thickness 75
Denier, thickness 0.08 m / m, weight 60 g / m ² ), and matting material [Matte Shionogi Pharmaceutical Co., Ltd.]
Carplex FPS-1, amorphous silicon dioxide fine powder, particle size of 50 to 97 μm] was added to an acrylic emulsion binder [DICN manufactured by Dainippon Ink and Chemicals, Incorporated.
AL-E7210K 5% aqueous solution]. As a coating treatment, a mat material mixture was applied to the substrate with a roll coater, and then dried in an oven at 70 to 90 ° C.

When a nickel film is formed on the dried base material using a conventional electroless nickel plating method as a plating treatment, nickel quickly adheres to the base material structure, and the entire surface of the base material structure is formed. , A nickel film was formed uniformly. When the resistance value of the obtained nickel film was measured, the variation of the resistance value was 5 Ω · cm ² or less in 1 m ² .

For comparison, when the same plating treatment was applied directly to the base material without performing the coating treatment, a portion where nickel did not adhere was formed on the base material, and the resistance value variation in 1 m ² was large. It was not practical. In the above examples, the fine particles of silicon oxide, which is a component of the matting agent, adhere to the smooth surface of the texture of the base material with a binder, and irregularities are formed on the texture surface, and the plating used in the electroless plating treatment is performed. It is conceivable that the catalyst is effectively adsorbed on the substrate structure and the deposited plating metal is uniformly attached.

As described above, the examples in which the matting agent is adhered to the substrate have been described. However, the same effect can be obtained even with fine particles used for the polishing agent.

[0027]

As described above, according to the present invention, prior to the electroless plating treatment, fine particles of a matting agent or a polishing agent as a mat material are adhered to a substrate structure to thereby form a plated metal such as a polyolefin resin. Even if the material is difficult to mount, it can be used as a base for chemical plating to form a plated metal film by electroless plating uniformly, and the metal coating obtained by the method of the present invention can be used as an electromagnetic wave shield. It can be widely used for materials, conductive materials, antistatic materials and the like.

[Brief description of the drawings]

FIGS. 1A and 1B are diagrams showing a method of the present invention in the order of steps.

[Explanation of symbols]

 1 base material 2 mat material 3 plated metal film

Claims (3)

[Claims] 1. A metal coating processing method comprising a pretreatment and a plating treatment, wherein the pretreatment is a treatment for applying fine particles of a mat material to a base material, and the plating treatment is performed by a pretreatment. A metal coating processing method, wherein electroless plating is performed on the base material thus formed, and fine particles of a mat material adhered to the base material are embedded to form a plated metal film. 2. The pretreatment is a process of applying an emulsion containing a mat material and an adhesive to a substrate, drying the substrate, and fixing the mat material to the substrate. 2. The metal coating method according to item 1. 3. The fine particles of the mat material adhere to the base material,
The metal coating method according to claim 1 or 2, wherein irregularities are formed on the surface of the substrate to improve the adsorption of a plating catalyst in the plating process.