Metal-coated fibrous objects comprising a fibrous base material, such as raw fibers, yarns, fabrics and final textile products; a synthetic resin base coat applied thereto; and a layer of metal deposited on said base coat by sputtering to a thickness in the range from 50 to 10,000 .ANG.. The metal is selected from the group consisting of gold, silver, aluminum, tin zinc, nickel, copper, cobalt and chromium, or selected from the group consisting of Hastelloy X, Permalloy, stainless steels, titanium nitride and cobalt alloys. The sputtering is carried out in an atmosphere of an inert gas selected from argon, neon and xenon, under a pressure in the range from 3.times.10.sup.-4 to 9.times.10.sup.-2 Torr, and at an impressed voltage in the range from 200 to 1,000 volts.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to metal-coated fibrous objects comprising a 
fibrous base material, such as raw fibers, yarns, fabrics and final 
textile products, and a layer of metal deposited thereon. 
2. Description of the Prior Art 
Vacuum deposition and electroless plating have been proposed as a means for 
the manufacture of metal-coated fibrous objects. 
For example, a technique is known in which a thin layer of aluminum is 
formed on the surface of twisted yarns by vacuum deposition, and woven, 
knitted and nonwoven fabrics are made from the metal-coated yarns thus 
prepared. This method, however, can hardly be put into practical use 
because of poor adhesion of the aluminum layer to the substrate fiber; the 
deposited metal tends to become detached in the succeeding fabric making 
steps or when resulting fabrics are strongly rubbed. Furthermore, fabrics 
made of such yarns cannot be laundered because the deposited aluminum is 
removed almost completely by a single normal laundering. 
Our study revealed that such troubles are caused by the facts that, in the 
vacuum deposition process, the energy of metal vapor bombarding the 
substrate fiber is too low to achieve sufficient adhesion and that light 
metals such as aluminum have poor resistance to acids and alkalis. 
Another problem associated with vacuum deposition is that the metals that 
can be used are limited only to those which melt at relatively low 
temperatures and vaporize with relative ease. This eliminates the use of 
highly corrosion-resistant materials, such as stainless steel and 
tungsten. 
Metal-coated fibrous objects made by electroless plating are also known. 
For example, dyed pieces of cloth are plated through immersion in an 
electroless plating solution, followed by several processing steps. This 
method is disadvantageous in that the discharged plating solution can 
cause pollution problems and hence a significant cost is added for the 
treatment of the used solution. In addition, this wet process requires 
drying and related steps, and suffers from deterioration of plated 
fabrics. 
Other difficulties are that, although copper, nichel, chromium, cobalt and 
some other metals can be plated with comparative ease, the method is not 
applicable to alloys, the metals which are difficult to be put into 
solution, and the metals which are unstable in solution, and that firm 
attachment of metal layer to fiber substrate cannot be expected because 
the plated layer is likely to be thick. 
SUMMARY OF THE INVENTION 
An object of the present invention is to offer new metal-coated fibrous 
objects with favorable metallic appearance and excellent light- and 
heat-shielding properties, in which any desired metal is firmly and 
reliably attached to substrate fiber while maintaining the characteristic 
functions of the fibrous base materials (raw fibers, yarns, fabrics and 
final textile products). 
Another object of the present invention is to offer metal-coated fibrous 
objects with improved resistance to acids, alkalis, water, weathering and 
abrasion and assuming colored metallic appearance. 
To accomplish these objects, the metal-coated fibrous objects of the 
present invention comprise a fibrous base material, such as raw fibers, 
yarns, fabrics and final textile products; a synthetic resin base coat 
applied thereto; and a layer of metal deposited on said base coat by 
sputtering to a thickness in the range from 50 to 10,000 .ANG.. 
Other objects of the present invention will become apparent from the 
preferred embodiments described below and the appended claims, and many 
other advantages not mentioned herein will be understood by those skilled 
in the art who put the present invention into practice.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
A first preferred embodiment of the present invention will be explained 
below by referring to FIGS. 1 and 3. 
The fibrous base material 1 may be any type of raw fiber, such as synthetic 
and natural fibers (e.g., polyesters, polyacrylonitriles, polyamides, 
rayon, cotton and wool), special fibers such as glass fiber and carbon 
fiber, or any combination thereof; a twisted yarn made from such raw 
fibers; a woven, knitted or nonwoven fabric made therefrom, which may have 
been raised or flocked for higher quality or rendered flame-retardant 
with, for example, a phosphorus compound; or the like. In Examples 1 and 2 
described later, plain weave fabrics made of 1-denier and 2-denier 
polyester fibers were used respectively as the fibrous base material 1. 
As the base coat 2 to be applied to the fibrous base material 1 may be used 
any synthetic resin coating of acrylic or polyester type. In Examples 1 
and 2, a clear, two-can urethane coating of acrylic type and a clear, 
two-can urethane coating of polyester type were applied respectively to a 
coating thickness of 2 to 10 microns. 
The base coat 2 may be applied to the fibrous base material 1 by spraying, 
dipping, roller coating or flow coating, each process having 
characteristic features of its own as shown later. 
The metal 3 to be deposited on the base coat 2 may be any metal or alloy 
that can be sputtered. Of particular advantage are metals such as gold, 
silver, aluminum, tin, zinc, nickel, copper, cobalt and chromium, 
Hastelloy X and Permalloy which are corrosion-resistant, nickel-base 
alloys, SUS316 (JIS) which is a stainless steel, titanium nitride, 
cobalt-base alloys, and others. The type of metal to be used may be 
selected depending of the particular use, the color desired, cost and 
other factors. In Examples 1 and 2, Hastelloy X and Permalloy were used 
respectively. 
The sputtering operation to deposite the metal 3 on the base coat 2 will be 
explained below by referring to FIG. 3. In this figure, numeral 11 
represents a vertical, low-temperature, high-rate sputtering apparatus 
equipped with an evacuating unit 15 and an argon gas cylinder 16 on the 
side at bottom portion. Numeral 12 shows a cylindrical target which is 
made, at least at its surface layer, of the metal to be deposited, such as 
Hastelloy X or Permalloy. Numeral 13 expresses a rod-shaped anode, which 
is designed to be impressed with a DC voltage of 200 to 1,000 volts 
against the target 12. Behind this anode 13 is set a fabric 14 (fibrous 
base material), which has previously been thoroughly scoured with a 
neutral detergent to remove oil, dirt and any other foreign substances and 
dried. 
The sputtering apparatus 11 is first evacuated by running the evacuating 
unit 5 to a pressure on the order of 10.sup.-5 Torr, argon gas is 
introduced to a pressure of 4.times.10.sup.-4 Torr, and a proper voltage 
is applied across the target 12 and anode 13. Metal molecules emitted from 
the surface of the target 12 are thus deposited on the opposite surface of 
the fabric 14. In Examples 1 and 2, the thickness of metal layer formed 
were 500 .ANG. for both, and the time required was about 30 seconds. 
Table 1 summarizes the properties of the treated fabrics thus obtained, 
together with those of a comparative example in which Hastelloy X was 
directly deposited by sputtering on a plain weave fabric made of 1-denier 
polyester fiber to a thickness of 500 .ANG.. The adhesion was herein 
evaluated by visual observation after immersion in 40.degree. C. hot water 
for 120 hours. 
TABLE 1 
______________________________________ 
Metallic Light 
Gloss Reflectance 
Adhesion 
______________________________________ 
Example 1 .circleincircle. 
100% .circleincircle. 
Example 2 .circleincircle. 
100% .circleincircle. 
Comparative Example 
.circle. 99% .circle. 
______________________________________ 
.circleincircle.: Excellent .circle. : Good 
As may be apparent from the table, the metal-coated fabrics obtained in 
Examples 1 and 2 are excellent in metallic gloss, light reflectance and 
adhesion to base coat 2, indicating that a metal coating thickness of 500 
.ANG. is sufficient to achieve satisfactory results. In Comparative 
Example, on the other hand, metallic gloss, light reflectance and adhesion 
are all slightly poorer with the same thickness because of the absence of 
base coat 2 on fabric 14. 
Applying a base coat 2 to the fibrous base material 1 prior to sputtering 
helps smooth the fine unevenness on fiber surface, minimizing irregular 
reflection at the metal layer 3 and giving treated fabrics of better 
metallic look. The base coat also serves to achieve higher adhesion of 
deposited metal, thus imparting higher resistance to repeated laundering. 
Other advantages over conventional methods include higher resistance to 
heat, melting and weathering, as well as better water repellency, 
electromagnetic-wave shielding property and electroconductivity, which 
make the metal-coated fibrous objects of the present invention usable for 
a wide range of applications. 
Suitable conditions of sputtering are detailed below. Neon, xenon and many 
other inert gases may also be used in place of argon at a pressure in the 
range from 3.times.10.sup.-4 to 9.times.10.sup.-2 Torr. If the pressure is 
less that 3.times.10.sup.-4 Torr, it is difficult to effect satisfactory 
sputtering, while blacking is likely to occur if the pressure exceeds 
9.times.10.sup.-2 Torr. Any impressed voltage may be adopted so long as 
sputtering can be effected satisfactory, but its preferable range is 
normally between 200 and 1,000 volts. 
The thickness of deposited metal layer may be selected in the range from 50 
to 10,000 .ANG.. When the thickness reaches about 100 .ANG., a faint metal 
color begins to appear, and a full metal color can be obtained at a 
thickness of about 300 .ANG.. When the thickness increases to about 500 
.ANG., the metal layer exhibits electroconductivity, light- and 
heat-shielding properties, and still other useful charactristics. 
Table 2 lists experimental examples for typical application methods of base 
coat 2 to fibrous base material 1 (spraying, dipping, roller coating and 
flow coating), and compares their features. 
TABLE 2 
______________________________________ 
Method Experimental Examples Features 
______________________________________ 
Spray A plain weave fabric made of 2-denier 
Fibrous feel 
Coating 
polyester fiber was sueded by raising, 
not impaired; 
and two-can urethane coating of acrylic 
stereoscopic 
type (non-yellowing) was applied with 
metallic 
an add-on of 20 g/m.sup.2, followed by drying 
look. 
(80.degree. C. .times. 120 min) and sputtering. 
Dip A plain weave fabric made of 1-denier 
Enhanced 
Coating 
polyester fiber was applied with two- 
film-like 
can urethane coating of polyester type 
feel; flat 
(non-yellowing) with an add-on of 
metallic 
100 g/m.sup.2, followed by drying (80.degree. C. 
gloss.. 
120 min) and sputtering. 
Roller A stretch fabric made of 1-denier cotton 
Same as 
Coating 
fiber was applied with one-can urethane 
above. 
coating with an add-on of 50 g/m.sup.2, which 
was set by immersion in water, followed 
by drying (80.degree. C. .times. 120 min) and sputter- 
ing. 
Flow A plain weave fabric made of 1-denier 
Same as 
Coating 
polyester fiber was sueded by raising, 
spray coat- 
and two-can urethane coating of poly- 
ing. 
ester type (non-yellowing) was applied 
with an add-on of 30 g/m.sup.2, followed by 
drying (80.degree. C. .times. 120 min) and sputtering. 
______________________________________ 
A second preferred embodiment of the present invention will be explained 
below by referring to FIG. 2. In this case, the synthetic resin topcoat 4 
is further applied to the surface of the metal layer 3 deposited by 
sputtering. 
As the material of topcoat 4 may be used any of the clear, two-can urethane 
coatings of acrylic or polyester type employed for the base coat 2, or any 
clear, one-can urethane coating of acrylic type. The topcoat 4 serves to 
protect the metal layer 3 deposited by sputtering, thus imparting the 
final product with improved resistance to acids, alkalis, water, 
weathering and abrasion. It is also possible to give metal-coated fibrous 
objects having a colored metallic look if a dye or pigment (organic or 
inorganic) is incorporated in this topcoat. The topcoat 4 may be applied 
by any of the coating methods described in the first preferred embodiment, 
but spray coating and roller coating are advantageous in terms of coating 
efficiency. 
The metal-coated fibrous objects of the present invention have various 
useful characteristics mentioned above while retaining the properties of 
the fibrous base materials used: lightweight, pliability, air 
permeability, water absorbing capability, and ease of cutting and sewing. 
With these outstanding features, they are of great value in the following 
applications: 
a. Draperies (light- and heat-shielding properties and weatherability) 
b. Lining cloths (favorable hand and antistatic property) 
c. Automobile ceiling materials and coldproof clothes (high light- and 
heat-shielding properties, ability to keep warm) 
d. Automobile fabric linings around ashtrays and fireproof clothings 
(incombustibility, flame retardancy and thermal resistance) 
e. Computer malfunction preventive materials and protective clothings 
against electromagnetic wave (electromagnetic shielding property) 
f. Automobile interior fabrics to prevent sparks caused by electrostatic 
charges (electroconductivity and antistatic property) 
As may be apparent from the foregoing, the metal-coated fibrous objects of 
the present invention feature improved metallic look, higher adhesion of 
deposited metal and better light- and heat-shielding properties, have 
higher resistance to acids, alkalis, heat, weathering and abrasion, and 
also assume colored metallic look as desired. 
While only a few preferred embodiments have been shown by way of 
illustration, many widely different embodiments may be made without 
departing from the scope and spirit of the present invention as defined in 
the appended claims.