US 2099641 A
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Nbv. 16, 1937. mm-A1. I ,6
GOLD LEAF SUBSTITUTE Filed Nov; 14, 1935 Smart 1300 The /'r- W3 Patented Nov. 16, 1937 umrso STATES PATENT OFFICE aosam ApplicatlonNovember In Germany Claims.
This invention relates to metal embossing foils and particularly to embossing foils of real gold, and to methods of producing the same.
Heretofore beaten gold leaf has largely been employed for the manufacture of real gold embossing foils. however, causes considerable difliculty and can only be carried out satisfactorily by carefully trained workers with extensive experience, owing to the fact that the beaten gold leaves are extremely difficult to handle. They tear very easily while being applied to the backing consisting of pergamyn paper coated with a layer of fusible material, which melts under the heat of the dye. After the embossing, the backing can be stripped of! leaving the gold leaves adhering to the article in the parts heated by the dye. I
These known foils are, however, also open to several other objections. Only nearly pure gold can be employed for producing the leaves, because alloys containing too' little pure gold cannot be beaten to the thinness necessary for producing sharp-edged embossings. Pure gold is. however, extremely expensive both to purchase and to beat, as the beating can only be carried out by skilled labor. Even the thinnest beaten gold is too thick to conform exactly to the con- :lours of the dye and give a very sharp impreson. go The objections are overcome according to the invention by employing cathodically deposited gold instead of beaten gold leaves for the manufacture of gold embossing foils. This presents the advantage that the gold layers can be made very much cheaper, because thinner and more uniform in thickness than those of beaten gold leaves. The gold alloy employed may contain a much lower proportion of pure gold, which further reduces the cost of the gold layer. The application of the gold by the known cathode atomization process does not need to be carried out by highly trained workers. Better embosslngs are obtained with the cathodically deposited gold embossing foils, owing to the extreme and uniform thinness of the gold layer, which conforms more accurately to the contours of the dye.
If the sizing layer is not transparent and consists of a light-reflecting covering color or lacquer, a substantially smaller weight of gold will give the desired effect.
Several embodiments of the new precious metal embossing foils and new methods of manufac turing certain of these foils are illustrated in the drawing, in which 55 Fig. 1 is a diagrammatic perspective view of an The employment of such leaves,
14, 1938, Serial No. 697,962 February 6, 1933 embosing foil in accordance with the invention of a modified form of the it has recently become possible to reduce the temperature about the atomizing cathodes to 23 C.-
Flg. 2 shows an embossing foil comprising a hard smooth layer next to the gold layer. In this figure the embossing foil consists of the support 0 of glassine paper, for instance, a fusible layer s of wax or the like, a harder and smoother varnish layer h, a layer a of gold or gold alloy atomized by the cathode and of a sizing layer 7c. Experiments have shown that the embosslngs produced with this foil adhere much longerunder stresses caused by friction than embossings of rolled gold foils with beaten gold leaf. The latter consist of glassine paper, a fusible layer, the gold leaf and the sizing substance. Consequently, the varnish layer directly on the gold leaf is lacking. After embossing the fusible layer is therefore the only coating remaining on the. outer side of the gold. If the embossing isfor example on a pencil, this remainder of the fusible layer will be first veryquickly rubbed out. of the em-' bossed recesses and then the beaten gold leaf, when the pencil is used. It has been found that the gold script thus embossed is already illegible and defaced before the pencil is worn out.
If the script is, however, embossed with the new foil atomized by cathode shown in Fig. 2, it remains without fading or being defaced until the pencil is entirely used up. Experiments have shown that the embossing lasts five times as long as with the known gold leaf, although the gold layer embossed thereon is considerably thinner than beaten gold. This durability, which even exceeds the practical requirements, is due to the fact that the embossed gold is protected against being rubbed off by the hard and smooth varnish layer. Instead of an ordinary varnish layer a layer may be employed produced from liquid cellulose substance, such as acetyl cellulose or nitro-cellulose. An extremely thin protecting fllm produced by applying zapon varnish offers a very great resistance to rubbing off. However,
the protecting film might consist of some other substance applied in liquid state, for example liquid celluloid, without departing from the invention.
When embossing pencils or other small articles produced in large quantities, it is important that the embossing foils illustrated in Fig. 2 and described can be supplied wound on rolls.
The term gold layer includes also a layer oi gold alloys or of any other metal or metal alloys capable of being cathodically atomized.
In stamping with the embossing foils described, the die hits the supporting layer and the sizing layer k sticks the foil 0 to the material which is to be covered.
Metal maybe saved by using a covering colour or sizing layer which is not transparent; preferably white or yellow covering colours of shiny brilliance are to be used.
l. A metallic embossing strip or sheet, comprising a cathodically deposited dense metallic foil of uniformthickness, a support, a releasable layer between said foil and said support, and a sizing layer on the side of said foil opposite said support.
2. A metallic embossing strip or sheet, comprising a cathodically deposited dense metallic foil of uniform thickness, a support, a releasable layer between said foil and said support, a hard, smooth, transparent layer next to said metallic foil composed of material selected from the group consisting of varnishes and lacquers and a sizing layer on the side of said foil opposite said support.
3. A metallic embossing strip or sheet, comprising a support, a releasable layer thereon, a hard, smooth, transparent layer on said releasable layer composed of material selected from the group consisting of varnishes and lacquers, a dense metallic toll of uniform thickness cathodically deposited on said transparent layer, and a sizing layer coated upon said metallic foil.
4. A metallic embossing strip or sheet as described in claim 1, wherein said sizing layer is opaque.
5. A metallic embossing strip or sheet as described in claim 1, wherein said sizing layer is a bright opaque substance.
STEFAN BACH. KONRAD KURZ.