JP2861059B2 - Metal-coated nonwoven fabric and method of manufacturing - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a fibrous body having conductivity, and more particularly to a metal-coated nonwoven fabric used as an electromagnetic wave shielding material, an antistatic material, and the like, and a method for producing the same.

(Prior art and its problems) Conventionally, as shown in JP-A-63-262900, for example, it has been proposed to use an organic fiber coated with nickel or copper as a nonwoven fabric as an electromagnetic wave shielding material or the like. However, nickel has poor conductivity, so the shielding effect is not sufficient, and copper is easily oxidized, so that the initial performance cannot be maintained. Both of them lack reliability and their use is limited. It is possible to coat silver, but silver has excellent oxidation resistance, but discoloration in a sulfurizing atmosphere poses a problem.

Copper sulfide coating is also used for antistatic applications, but cannot be used for electromagnetic wave shielding due to poor conductivity.

On the other hand, the use of metal fibers themselves as woven or non-woven fabrics is also being considered, but stainless steel and nickel have drawbacks such as poor conductivity and copper are easily oxidized, and these metals are heavy and difficult to process. It is rarely used.

(Objects of the Invention) In view of these circumstances, the present inventors have repeatedly studied a fibrous body having excellent conductivity, environmental stability, and a wide range of application.
The present inventors have found that a high-performance fibrous body which solves the conventional problems can be obtained by coating an organic fiber with silver or copper to form a nonwoven fabric and then coating with a resin paint, and has reached the present invention.

(Constitution of the Invention) That is, according to the present invention, (1) a metal-coated nonwoven fabric comprising an organic fiber, a nonwoven fabric made of a metal coated on the organic fiber, and a resin paint coated on the nonwoven fabric; A method for producing a metal-coated nonwoven fabric, which comprises coating an organic fiber with a metal to form a nonwoven fabric, and then coating the nonwoven fabric with a resin paint.

Here, organic fibers are natural and synthetic organic fibers,
That is, cotton, hemp, regenerated cellulose, polyamide, acrylic,
Fibers such as polyolefin and polyester.

The thickness of organic fiber is 0.1-15d (d = denier), 0.1d
If it is thinner, a larger amount of metal is required and the specific gravity is higher. If the thickness is more than 15 d, the amount of metal is reduced, but the fibers are hard and the weaving becomes difficult.

The metal to be coated is silver or copper, and the other metals have no advantage in terms of conductivity, cost, and the like.

The method of coating the metal is an electroless plating method, and other methods include a vacuum deposition method and the like, but the electroless plating method is excellent in mass productivity.

The coating amount of the metal is 5 to 50% by weight. If the amount is less than 5% by weight, the fiber cannot be sufficiently coated, and the conductivity becomes poor.
When the content is more than the percentage by weight, the specific gravity increases and the conductivity also reaches a plateau.

The method of coating the resin paint may be any method such as an immersion method, a spray method, and a coating method, but the immersion method is preferable in order to uniformly coat the fiber surface and increase the strength. The coating of resin paint eliminates metal oxidation and discoloration, strengthens the bonding force between fibers, and is excellent in conductivity and environmental safety.
It has been confirmed that a nonwoven fabric having a wide range of applications can be obtained.

Examples of the resin paint used include a cold-setting resin such as an epoxy resin paint, an acrylic resin paint, a polyester resin paint, a polyurethane resin paint, and a phenol resin paint. The coating amount of the resin paint is 5 to 60% by weight. If it is less than 5% by weight, uniform coating is difficult, and if it is more than 60% by weight, flexibility is lost.

When processing into a nonwoven fabric, only metal-coated organic fibers may be used, but depending on the required conductivity and other physical properties, it is also possible to mix the same or different organic fibers to form a nonwoven fabric. . In this case, the mixing ratio of the same kind or different kinds of organic fibers is 99.8% by weight or less, and if it exceeds 99.8% by weight, the conductivity is remarkably deteriorated and the antistatic effect may be lost.

The non-woven fabric may be a single layer of non-woven fabric containing metal-coated organic fibers, or may have other physical properties or design by being multi-layered with non-woven fabric of other organic fibers or non-woven fabric of pre-dyed organic fibers. It is also possible.

Specific examples of application include electrocardiograms utilizing safety,
Electrode materials used for measurement of brain waves, etc., electromagnetic wave shield materials for filters and housings that emit heat using air permeability, electromagnetic wave shield materials for electric wires using flexibility, blanket covers and bed covers using design, etc. Anti-static bedding materials.

Next, the present invention will be described specifically with reference to Examples.
The following examples do not limit the scope of the invention.

Examples Acrylic fiber, polyamide fiber, polyester fiber,
Organic fibers composed of polypropylene fiber and rayon fiber were coated with silver and copper by an electroless plating method.

Electroless plating was immersed in a scouring agent, washed with water, immersed in an aqueous solution containing stannous chloride 10 g / L, hydrochloric acid 20 mL / L, washed with water, and then contained palladium chloride 1 g / L and hydrochloric acid 20 mL / L. After the catalyst was immersed in an aqueous solution and catalyzed, the plating solution having the following composition was quantitatively used. Since all metal ions in the plating solution are reduced and precipitated, an amount of the plating solution containing an amount of the metal ion to be coated was used.

Using these, a non-woven fabric having a fiber basis weight of 50 g shown in Table 2 was prepared, and in the comparative example, as it was, a resin coating was coated in the example, the tensile strength was measured, and then a sulfuration test and a moisture resistance test were performed. The surface resistance before and after the test was measured. Table 3 shows the results. In the sulfidation test, the sample was immersed in a 10% aqueous solution of potassium polysulfide at 25 ° C. for 5 minutes, and in the humidity resistance test, the sample was allowed to stand in saturated steam at 70 ° C. for 10 days.

(Effects of the Invention) The metal-coated nonwoven fabric of the present invention has the following effects by adopting the above configuration. That is, it is a novel conductive material which is excellent in conductivity, tensile strength, sulfidation resistance, moisture resistance, flexibility and the like.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01B 13/00 501 H01B 5/14-5/12 H05K 9/00

Claims (9)

(57) [Claims] 1. 5 to 50% by weight based on the weight of the fiber after coating
Characterized in that the fibers in the nonwoven fabric are coated with 5 to 60% by weight of a resin based on the weight of the nonwoven fabric after resin coating. Conductive non-woven fabric. 2. The conductive nonwoven fabric according to claim 1, wherein said organic fibers have a thickness of 0.1 to 15 d. 3. The conductive nonwoven fabric according to claim 1, wherein the metal is silver or copper. 4. The conductive nonwoven fabric according to claim 1, wherein the conductive nonwoven fabric is laminated with another organic fiber nonwoven fabric to form a multilayer structure. 5. The method according to claim 1, wherein the organic fiber coated with the metal is made into a nonwoven fabric, and then the nonwoven fabric is coated with a resin paint.
A method for producing the conductive nonwoven fabric according to any one of claims 1 to 4. 6. The method according to claim 5, wherein the coating of the metal is performed by an electroless plating method. 7. The method according to claim 5, wherein the resin coating is a room temperature curing type. 8. The nonwoven fabric according to claim 5, wherein said metal-coated organic fiber is mixed with an organic fiber of the same or different kind in an amount of 99.8% by weight or less based on the whole nonwoven fabric. The described method. 9. The method according to claim 5, further comprising stacking another nonwoven fabric on the nonwoven fabric containing the metal-coated organic fibers to form a multilayer structure.