Stock material or miscellaneous articles – Coated or structually defined flake – particle – cell – strand,... – Rod – strand – filament or fiber
Reexamination Certificate
2000-11-09
2004-03-09
Kelly, Cynthia H. (Department: 1774)
Stock material or miscellaneous articles
Coated or structually defined flake, particle, cell, strand,...
Rod, strand, filament or fiber
C428S389000, C428S395000, C428S378000, C428S379000, C428S381000, C428S394000
Reexamination Certificate
active
06703123
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a metal-coated white conductive fiber having a high degree of whiteness and superior conductivity, in which a metal coating provided on the fiber has superior adhesiveness. In particular, the present invention relates to a conductive fiber having a high degree of whiteness, comprising a metal coating having superior adhesion strength and conductivity provided on a fiber material composed of a polymer, such as a polyamide fiber or a polyester fiber. The conductive fibers of the present invention can be used as material for various cloths and clothing, and in addition, can be used in industrial materials, such as electromagnetic shielding materials, antistatic materials, and alternative materials for electrodes and electric cables.
2. Description of the Related Art
Conductive fibers are conventionally known in which metal thin-films are coated on the surfaces of fibers composed of polymer materials, such as polyamide fibers and polyester fibers, and in order to improve the adhesion of metal coatings thereto, various methods have been attempted. For example, in the case in which copper sulfide is coated, a method is disclosed in Japanese Examined Patent Application Publication No. 1-37513 in which a polymer material is pretreated with a dye having groups for binding copper ions so as to form bonds with copper ions and is then sulfurized, and a method is disclosed in Japanese Unexamined Patent Application Publication No. 6-298973 in which groups for binding copper ions are adhered to a fiber surface roughened by an alkaline treatment, and copper sulfide is then bonded thereto. In addition, in the case of materials which are difficult to plate with metal, such as aramid fibers, a method is disclosed in, for example, Japanese Translation of PCT International Publication for Patent Application No. 6-506267, in which metal ions are adhered to the fiber surface by using polyvinylpyrrolidone (PVP) and are then reduced so as to perform metal plating.
However, the plating method using PVP cannot be commonly used since it can only be applied to limited types of fibers. In addition, in the coating methods using the groups for binding copper ions, there are problems in that the metal coating obtained is only composed of copper or compounds thereof, and the adhesion strength of the metal coatings is not always sufficient. In this connection, adhesion strengths of metal coatings can be generally enhanced when fiber materials are roughened by alkaline treatment; however, when the degree of roughening of the surface and the conditions of the metal coating are not properly controlled, satisfactory effects cannot be obtained.
In addition, as a conventional method for manufacturing white conductive fiber, there are methods, for example, a method (a) for melt spinning a starting material for fiber compounded with a white conductive component, a method (b) for coating a white component on the surface of a fiber material containing a carbon component, which are disclosed in Japanese Unexamined Patent Application Publication Nos. 4-2808, 2-169715, 4-361613, and 60-126321, and a method (c) for coating a metal on fiber material by various methods, which are disclosed in Japanese Unexamined Patent Application Publication Nos. 7-179769 and 4-263667. However, the methods described above have the following problems as described below. That is, in the methods (a) and (b), the conductive fiber manufactured thereby has a volume resistivity of 10
5
to 10
6
&OHgr;·cm or more, which is not sufficient conductivity for use in electromagnetic shielding, and hence, the conductive fiber thus formed can be applied only to antistatic applications and the like. In addition, in the method (c), pretreatment is performed using a dye prior to the metal coating in order to enhance the adhesion between the fiber and the metal to be coated, and due to the dye mentioned above, the original whiteness of the fiber material is degraded so that the coating has a slightly blue, green, gray, or black tone, whereby there are problems when they are used for textiles and for clothing.
In addition, a silver coated fiber used for conductive fillers and electromagnetic shielding materials is known which is formed by silver plating on an organic fiber; however, the longer fibers produced thereby are approximately 20 cm, and hence, the silver coated fiber cannot be commonly used since it is not a continuous fiber. In the case in which metal plating is performed on a continuous fiber in a state in which the fiber is wound around a shaft in the melt spinning step, when the continuous fiber in a wound state (wound fiber body) is metal plated by dipping in a plating solution, the plating solution may not sufficiently infiltrate inside the wound fiber body around which the continuous fiber is repeatedly wound, and almost all of the fibers are defective products having mottled plating, whereby it is difficult to obtain a continuous fiber in which the entire surface thereof is uniformly plated with metal.
SUMMARY OF THE INVENTION
The present invention solves the problems in the conventional white conductive fiber described above, and accordingly, an object of the present invention is to provide a white conductive fiber having a high degree of whiteness, and superior conductivity, and is to provide a manufacturing method therefor. The white conductive fiber described above has a metal coating uniformly coated on the entire surface thereof even though the fiber is a continuous fiber in a wound form. In addition, another object of the present invention is to provide a metal-coated conductive fiber having a metal coating thereon, in which the metal coating has superior adhesion strength and superior coating strength in addition to high conductivity. Furthermore, the present invention provides a method for manufacturing the conductive film described above and an apparatus therefor.
Conductive Fiber
The present invention relates to a conductive fiber composed of a fiber material provided with a metal coating thereon having a degree of whiteness (L value in accordance with the Lab method) of 50 or more and a volume resistivity of 100 &OHgr;·cm or less. In addition, the present invention relates to a conductive fiber composed of a fiber provided with a metal coating thereon, in which the surface of the metal coating has an orange peel texture.
The conductive fiber according to the present invention preferably has a degree of whiteness (L value) of 50 or more and a volume resistivity of 100 &OHgr;·cm or less and has a metal coating thereon having an orange peel texture. As a fiber material, a polyester fiber, a polyamide fiber, or an acrylic fiber can be used. As a metal coating, silver, gold, platinum, copper, nickel, tin, zinc, palladium, or an alloy thereof may be used. The conductive fiber of the present invention more preferably has a degree of whiteness (L value) of 55 or more, a volume resistivity of 0.1 &OHgr;·cm or less, and a metal coating provided with an orange peel surface having a surface roughness of 0.01 to 1 &mgr;m.
Since the conductive fiber according to the present invention can be obtained in a continuous fiber form, the fiber is easily used for woven fabrics and the like and can be widely used for clothing materials and various fabric materials. In addition, since the fiber has superior conductivity, by weaving a small amount thereof with a base material, superior conductivity can be obtained without impairing the hue and the feeling of the base material. The conductive fiber can also be used for various conductive materials such as an electromagnetic shielding material. In addition, since the conductive fiber has beautiful whiteness, when spun with cloths or base materials provided with a hue having a high degree of whiteness, a product can be obtained without impairing the original colors thereof. Furthermore, since the conductive fiber can be formed of a commonly used continuous fiber, such as a polyamide fiber, a polyester fiber, and an acrylic f
Furuya Nobuo
Imai Hiroyuki
Maeda Yusuke
Shibuta Daisuke
Tsunashima Makoto
Kelly Cynthia H.
Mitsubishi Materials Corporation
Thompson Camie
LandOfFree
Conductive fiber, manufacturing method therefor, apparatus,... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Conductive fiber, manufacturing method therefor, apparatus,..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Conductive fiber, manufacturing method therefor, apparatus,... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3234485