A card is disclosed that incorporates a removable scratch-off coating to hide printed symbols. The card is constructed so that the scratch-off coating is selectively retained by the card, in the form of symbols, or as a background for symbols, when the scratch-off coating is removed. The selective retention of scratch-off coating material to the card is accomplished by incorporating into the card, between the substrate and the scratch-off coating, a clear release coat patterned to form symbols. When the scratch-off coating material is applied to the card during construction, it either adheres directly to the substrate in the form of symbols, or it adheres to the substrate in the background for the symbols, depending on how the release coat is applied. When a player rubs the scratch-off coating material, it releases from the release coat and remains adhered to the substrate to create either symbols or the background for symbols.

FIELD OF THE INVENTION 
The present invention relates to removable scratch-off coatings and items 
that incorporate scratch-off coatings to obscure images from view. 
BACKGROUND OF THE INVENTION 
Many instant-win lottery cards are coated in one or more regions by 
scratch-off coating compositions in order to hide symbols that comprise 
game indicia. When a purchaser of such a card scratches off the coating, 
he or she reveals the symbols and learns the results of the game. 
Instant-win tickets, promotional labels and other games similarly 
incorporate scratch-off coatings to hide symbols. 
Instant-win lottery cards, like other games that incorporate scratch-off 
coatings, typically are layered with a complex array of coatings of 
varying compositions. The complex construction provides a card that is 
both durable and relatively secure from tampering. U.S. patent application 
Ser. No. 08/407,185 (which application is incorporated herein in its 
entirety by this reference) discloses several arrays of coatings that a 
card can incorporate. 
The substrate, or base, of many instant-win lottery cards is cut from 
cellulosic board stock. A metallic foil is then laminated to the board 
stock. The metallic foil is coated with a primer to minimize oxidation and 
to provide a surface that is receptive to ink. After symbols have been 
printed atop the primer in pigmented ink, a sealant is frequently applied 
over them to protect the printed symbols. A scratch-off coating, which 
typically is comprised of an opaque metallic latex, is applied over the 
printed symbols and sealant to obscure the symbols from view. To 
facilitate removal of the latex from the card, existing cards often 
further include at least one "release" coat interposed between the 
scratch-off coating and ink sealant. 
In addition to providing a durable substrate for the production of 
instant-win cards, a cellulosic board stock and foil combination provides 
a level of opacity and impermeability that is important to the security of 
the card. The board stock and foil combination inhibits unscrupulous 
players from viewing the printed symbols by examining the ticket before a 
light source, a process known as candling. The non-porous foil also 
protects the card from chemical tampering by preventing unscrupulous 
players from chemically wicking the hidden symbols to the underside of the 
substrate where they might become visible. 
While existing foil-based cards may be durable and secure, they are 
difficult and expensive to manufacture because they are constructed of 
numerous coatings and layers. Many times these coatings and layers are 
comprised of specialty chemicals to ensure that the layers are compatible 
with and adhere to one another. These specialty chemicals are often very 
expensive. The foil in foil-based cards is another significant raw 
material expense, and it adds an element of complexity to the 
manufacturing process. Foil-based cards also are difficult to recycle 
because the metal foil interferes with conventional paper recycling 
processes. The foil further prevents electrostatic printing techniques 
from being employed, reducing the variety of graphics available for use. 
The use of ink to print the symbols is also problematic. Ink printing 
requires that two additional processing steps be incorporated into the 
card manufacturing process, one printing step and another sealant step. 
Each of these steps substantially increases the time and expense required 
to manufacture existing cards. 
An instant-win card that is different from those discussed above was 
recently introduced. This card appears to omit foil from its base, and 
instead to incorporate a water-based black coating over the conventional 
board stock. The black coating is approximately one micron thick and 
comprised of carbon, chlorine, and calcium. This black coating is believed 
to be either identical or virtually identical visually to the composition 
of the ink used to print the hidden images on the card thus diminishing 
the possibility that an unscrupulous player could distinguish the hidden 
images from the coating through candling. To contrast the hidden images 
from the black base coating, and to receive more readily printed symbols, 
the card interposes a lighter color coating between them. This card 
however, like others discussed above, is complex. 
SUMMARY OF THE INVENTION 
Cards produced according to the present invention are simplified greatly 
because pigmented ink is not used to print the hidden symbols. It thus is 
not necessary to disguise the ink or physically to protect the ink from 
tampering processes. In one embodiment, the card is constructed so that 
the scratch-off coating is selectively retained by the card, in the form 
of symbols, when the bulk of the scratch-off coating material is rubbed 
off the card. The scratch-off coating material effectively becomes the 
medium used to visualize legible symbols. The selective retention of 
scratch-off coating material to the card in the form of symbols is 
accomplished by incorporating into the card, between the substrate and the 
scratch-off coating, a clear release coat having voids in it in the form 
of symbols. During card construction, when the scratch-off coating 
material is applied to the card over the release coat, it adheres directly 
to the substrate through the voids in the release coat in the form of 
symbols. When a player rubs the scratch-off coating material, it releases 
from the areas where the release coat is applied and remains adhered to 
the substrate in the form of symbols where the release coat is not 
applied. 
The card also can be constructed so that the release coat is applied to the 
card in the form of the desired symbols. When a player rubs the 
scratch-off coating material, the scratch-off coating material is released 
selectively from the card where the symbols have been printed with the 
release coat. A portion of the scratch-off coating material that is 
applied directly to the substrate is retained by the card at the interface 
between the card and the scratch-off coating. In such a construction the 
scratch-off coating material becomes the background for the symbols and, 
because the scratch-off coating material separates from the card in the 
form of symbols where the clear release coat is applied, the substrate to 
which the release coat is applied becomes the medium through which legible 
symbols appear. 
Because the medium that forms the symbols is typically either the 
scratch-off coating material or substrate, and because the release coat 
that patterns the symbols is typically clear, an unscrupulous player is 
less likely by candling to discern the symbols in an item produced 
according to the present invention. Moreover, because pigmented ink is not 
employed to print the hidden symbols, unscrupulous players are less able 
to compromise the game prematurely through chemical wicking. Lastly, 
because the substrate or scratch-off coating material can double as the 
printing medium the construction of the card and the complexity of the 
coatings and layers is greatly simplified. 
It is an object of the present invention, therefore, to construct a simple 
instant-win game that incorporates a removable scratch-off coating that 
does not contain a complex array of layers and coatings. 
It is also an object of the present invention to construct an instant-win 
card that incorporates a removable scratch-off coating that inhibits 
candling and other means of tampering that prematurely compromise the 
game. 
It is a further object of this invention to overcome the need for pigmented 
ink to produce legible symbols in a game card. 
A still further object of this invention is to overcome the need to use 
excessive amounts of specialty chemicals and compositions in layers and 
coatings of game cards, and to increase the number of compositions that 
can be incorporated suitably into the layers and coatings of cards. 
Other aspects, objects, and advantages of the invention will become 
apparent to those skilled in the art upon reference to this specification.

DETAILED DISCUSSION 
FIG. 1 illustrates a card 5 constructed according to one embodiment of the 
present invention. Card 5, configured as an instant-win lottery card, is 
divided into secure and unsecure areas 7 and 8 respectively. Promotional 
material to which the player is first exposed typically is printed in 
unsecure area 8. Promotional material also may be printed atop secure area 
7. Legible symbols that inform a player of the results of the game are 
hidden by the scratch-off coating material contained in the secure area 7 
of card 5. A player reveals the hidden symbols in secure area 7 by 
removing the scratch-off coating material. 
As illustrated in FIG. 2, card 5 is constructed of several layers and 
coatings. Layer 10 forms the substrate, or base ply, of card 5. Eight or 
ten point board stock typically is used as the base ply in instant-win 
lottery cards and because of its durability and structural rigidity is 
suitable for use as the substrate in cards of the present invention. 
Durability and structural rigidity are not critical to the invention, 
however, and lighter paper such as 60 lb. paper also can be employed. 
Indeed, because the scratch-off coating does not have to be as thick as 
the scratch-off coating in other cards (as will be discussed later in this 
specification), lighter and less expensive substrates can be used readily 
with this invention. Although foil conceivably could be laminated to the 
board stock, card 5 of the present invention omits foil so that it is 
simpler and more readily recycled. Indeed, base layer 10 itself may be 
constructed of recycled fibers. Alternatively, other materials, both 
natural and synthetic, can be used for the substrate without departing 
from the scope or spirit of this invention. Any substrate material can be 
employed that provides a surface that can retain the layers applied to the 
card and that provides the rigidity and strength to withstand forces 
applied to the card during processing, handling, and use of the item or 
game. 
Much commercially available substrate material is not suitably colored to 
receive printed symbols and to provide a visible contrast with such 
symbols. In addition, the rough texture of most commercially available 
board stock makes it ill-suited to receive printed symbols directly, 
especially symbols that are finely detailed and defined. Moreover, 
commercial board stock and other substrate materials may be incompatible 
with certain printing media. A primer may be employed to overcome such 
problems. In FIG. 2 a primer, shown as layer 20, is coated over the 
substrate to receive printed symbols more readily and to create a better 
contrast with which to view printed symbols. A suitable primer is adapted 
to adhere to base ply 10, to receive the scratch-off coating material 
composition, and to resist separating from the base ply 10 when the 
scratch-off coating material is removed. In addition, the primer must be 
capable of receiving the composition of release coat 30 that is also 
applied to the primer. 
Many compositions and types of materials are suitable for use as a primer. 
The primer may be a sheet of material adhered to the base ply, or it can 
be a coating chemically or otherwise applied over the base ply. Many 
compositions of commercially known and available coatings are suitable for 
use as primers in cards of the present invention, including primers that 
are used in existing cards. A suitable composition of primer 20, that can 
be applied to a cellulosic substrate, is a vinyl chloride resin dissolved 
in acetate solvent with titanium dioxide pigment. Other pigments or 
colorants can be added to the primer to impart the desired color to the 
primer, to best contrast the primer with the scratch-off coating material. 
Release coat 30 is applied over primer 20 so that a player can rub 
scratch-off coating 40 from the card where release coat 30 is applied. In 
the embodiment shown in FIG. 2 release coat 30 also acts as the negative 
pattern through which scratch-off coating material is adhered selectively 
to the primer 20 in the form of predetermined symbols. Voids in release 
coat 30 in the form of symbols dictate the symbols that appear on the card 
5 when a player removes scratch-off coating 40. Exemplary voids 31 and 32, 
in the form of symbols "G" and "I", are shown in the release coat 30 of 
card 5. When scratch-off coating is applied to card 5 during construction, 
it adheres to the release coat 30, but also adheres directly to primer 20 
at voids 31 and 32 in the form of the symbols "G" and "I." When the 
scratch-off coating 40 is separated from the release coat 30 by rubbing, 
the material from scratch-off coating 40 that was adhered to the primer 20 
remains adhered thereto at the interface between the scratch-off coating 
and the primer, revealing imprinted symbols "G" and "I." 
In another embodiment of the invention, card 5' shown in FIG. 3, the 
release coat 30' is applied directly to the primer 20' in the form of the 
symbols that comprise the game indicia. When rubbed, the scratch-off 
coating 40' that is applied over the release coat 30' completely separates 
from the card where the symbols have been imprinted by the release coat. A 
thin layer 31' and 32' of the scratch-off coating material remains bonded 
to the card in the area surrounding the symbols 31' and 32', thereby 
creating a background for the symbols G and I formed by the primer. 
While it is possible to use. a tinted or opaque release coat, release coat 
30 usually is clear so that it does not interfere with the contrast 
between primer 20 and the scratch-off coating material that adheres to the 
primer to create symbols. The clarity of the release coat also inhibits 
optical compromise through candling, because one cannot visibly 
distinguish voids 31 and 32 where release coat 30 is not applied from the 
clear release coat 30 itself Release coat 30 can be comprised of many 
different compositions that are known and commercially available. Any 
release composition that adheres to primer 20 more than it adheres to the 
scratch-off coating 40 is suitable because it permits a player to rub the 
scratch-off coating 40 from card 5 while the release composition is 
retained by primer 20. Compositions of alcohol soluble polyamide resins 
and zinc stearate are frequently employed as release compositions in 
instant-win lottery cards and are especially suitable for cards of the 
present invention when primer 20 is a vinyl chride resin dissolved in 
acetate solvent, and the scratch-off coating composition is a metallic 
latex. 
Another release coat composition that can be used when primer 20 is a vinyl 
chloride resin dissolved in acetate solvent and the scratch-off coating 
composition is a metallic latex is a varnish that is cured by ultraviolet 
radiation. Because this type of coating is not air-dried it remains 
unfixed until exposed to ultraviolet radiation. Exemplary compositions for 
such a release coating include (by weight) approximately 30-70% monomer, 
5-40% epoxy oligomer, and, if appropriate, 3-12% benzophenone and various 
anti-foamants, flow/leveling agents, photo-initiators, and synergists. 
Because these components cross-link when exposed to ultraviolet radiation, 
this alternative release coating typically cures to a hard and durable 
finish. 
Applied atop release coat 30 is scratch-off coating 40. The composition of 
the scratch-off coating 40 is adapted to adhere to the release coat 
composition, yet to separate from the release coat composition when 
scratched or rubbed off. The scratch-off coating material also is adapted 
to remain at least partly adhered to the primer 20 when the scratch-off 
coating is scratched or rubbed. The composition of the scratch-off coat 40 
also should be tinted or colored suitably to provide a visible contrast 
between the scratch-off coating material that remains adhered to primer 20 
after the scratch-off coating has been rubbed or scratched off If the 
primer 20 is a light color, for example, dark colors can be incorporated 
into the scratch-off coating composition for beneficial visual effects. 
Although many scratch-off coating materials are suitable for use in the 
present invention, latex based compositions laced with metallic particles 
such as aluminum, copper, or bronze have proven especially effective for 
use with the release coat compositions disclosed herein. Latex based 
compositions also have proven effective to adhere, in the form of discreet 
and finely defined symbols, to primer compositions of vinyl chloride 
resins dissolved in acetate solvent. Latex based compositions are used as 
scratch-off coating materials in many applications and are readily 
available for use. 
Many other scratch-off coating materials can be used with cards of the 
present invention. Indeed, because of the minimal amount of coating that 
must be applied to cards of the present invention, many coating materials 
that would not be suitable for other cards are suitable for cards of the 
present invention. In contrast to scratch-off coatings in many cards, 
which generally must be completely opaque to hide the symbols printed to 
the card, the scratch-off coating of the present invention can be very 
thin and generally needs only to cancel the reflectivity of the release 
coat in order to hide the symbols incorporated into the card. Mat-like 
finishes are especially suitable for application to reflective release 
coats, because they tend to cancel reflectivity efficiently. Any 
composition that remains bound to the primer at its interface with the 
primer, releases from the release coat, and can be scratched off a card is 
generally suitable for use as a scratch-off coating material in cards of 
the present invention. 
Cards 5 and 5' in FIGS. 2 and 3 form only two embodiments of the present 
invention, and many other items can be constructed according to the 
present invention. Indeed, while much of the foregoing discussion relates 
to instant-win lottery cards, the invention can be practiced with any item 
or game in which a scratch-off coating is incorporated to hide symbols 
printed thereon. The foregoing is provided only for purposes of 
illustrating, explaining, and describing embodiments of the present 
invention. Modifications and adaptations to these embodiments will be 
apparent to those skilled in the art and may be made without departing 
from the scope or spirit of this invention.