Patent Application
20070287143
With reference to the figures,
With reference to the figures,
On one side (i.e., the back side) of the polypropylene substrate sheet 12, a layer of adhesive 14 is applied. Alternatively, the adhesive 14 may be pre-applied to the substrate sheet 12 rather than independently applied. The adhesive 14 is preferably a conventional very low-tack, pressure sensitive adhesive that is commercially available, which allows the inventive chalkboard surface to attach and detach easily from a flat surface at the discretion of a user without damaging the surface to which it attaches. In the context of the present invention a smooth, even layer of adhesive 14 is applied to the polypropylene substrate sheet 12, however, it should be understood that a non-even layer of adhesive may be applied, where more adhesive is applied at the corners and/or at the center of the polypropylene sheet than in other areas, or where adhesive is applied at the corners and/or at the center of the polypropylene sheet, but none is applied elsewhere. Selectively applying adhesive in such designated areas rather than across the entire back side of the polypropylene sheet further assists in keeping the total weight of the chalkboard surface 10 down to a desired level. The DCM VinyLike product mentioned as the preferred polypropylene substrate is manufactured with an acceptable adhesive layer which is pre-applied to the back side of the substrate.
On the same back side of the polypropylene substrate 12, a selectively removable, protective, paper-based, silicone backing release sheet or liner 16 is applied to the adhesive layer 14 to prevent the adhesive layer 14 from attaching to other surfaces in an unwanted fashion and/or to prevent foreign materials from attaching to the adhesive layer 14, when the chalkboard surface 10 is not in use or is placed in storage. In applying the chalkboard surface 10 to a door, for example, a user first peels the liner 16 away from the adhesive layer 14, then places the chalkboard surface 10 against a door, and then manually smoothes the chalkboard surface 10 so that it is flat against the door. The DCM VinyLike product mentioned as the preferred polypropylene substrate is manufactured with an acceptable release liner layer which is pre-applied to the adhesive layer.
On the reverse side (i.e., the front side) of the polypropylene substrate, at least one coat of ink 20 is applied, which forms an abrasive exterior after it dries, and importantly, results in a chalkboard surface 10 that is lighter in weight, with all other aspects of the chalkboard surface 10 being equal (i.e., type and dimension of substrate, release liner and adhesive). In a preferred embodiment, a single coat of ink 20 is sufficient to provide for a desirably coarse surface suitable for use with chalk. When utilizing ink 20, the chalkboard surface 10 remains attached to a wall for a much greater period of time than a similar final product made with paint, which typically falls off the wall from its own weight relatively quickly. Further, even after the initial use (and subsequent uses), the chalkboard surface 10 may be removed and then re-applied to a wall or other suitable surface for later use.
In a preferred embodiment, the ink 20 utilized in connection with the invention is a combination of UV Stampable Matte Varnish and a pigment or dye such as that marketed under the trade name Sinvacure UV IMP #50 Black (or other similarly colored dye or pigment), both available through the Flint Group of Ann Arbor, Mich. Most preferably, the ink layer 20 is formed by combining the UV Stampable Matte Varnish and the Sinvacure UV IMP #50 Black in a ratio of about 4 to 1, such that the ink composition comprises approximately 80% of the UV Stampable Matte Varnish and approximately 20% of the Sinvacure UV IMP #50 Black. In forming the chalkboard ink 20, no other additives are required. In particular, aside from the ingredients described herein, the ink 20 does not require adding of mildly abrasive materials, resinous or plastic materials or bulking agents as used in conjunction with prior art devices.
It should be understood, that other dyes or pigments instead of the Sinvacure UV IMP #50 Black may be employed to change the color of the ink that is used. Even when another dye or pigment is used, the UV Stampable Matte Varnish should remain constant, although relative ratios may change somewhat. In connection with the foregoing, traditional shades of green or grey may be used. Likewise, lighter colors, including light shades of pink, yellow and even white (preferably for use with colored chalk), may be prepared by replacing the Sinvacure UV IMP #50 Black, or the like, with another appropriately colored dye or pigment, or combination thereof.
After the ink 20 dries, the coating is approximately 1 mm thick (or less). The resulting surface has a dull, matte finish which is abrasive, allowing the surface to receive and to erasably retain markings made with conventional chalk. The applications of this product range from regular walls, doors, tables, children's rooms, kitchens, play areas, home offices, or wherever else one might find a chalkboard marking surface to be useful.
The advantages of the present invention, particularly, the lesser relative weight of the inventive chalkboard surface 10, are readily apparent from the following experiment which was performed to compare the present invention with other products that are available on the market and are representative of the prior art. In the experiment, a layer of conventional chalkboard paint sold under the trademark Benjamin Moore Studio Finishes™ chalkboard paint (307) was applied to a sample section of DCM VinylLike polypropylene substrate. When the chalkboard paint was applied, it did not properly adhere to the VinylLike surface, receding instead and forming a light-gray film. To form a grittier surface to which the chalkboard paint could properly adhere, an intermediate layer of primer was applied with a roller to the vinyl, as suggested by a paint specialist. Although the primer was required for the chalkboard paint to adhere, it added significantly to the overall weight of the marking surface. Once the primer was applied, the surface began to noticeably curl at its edges due to the weight and thickness of the primer. After the primer dried, the chalkboard paint was evenly applied to the primed surface. A 19″×19″ section of the primer-paint treated surface was removed and compared to a section of the inventive chalkboard marking surface 10 which was formed from the same VinylLike substrate 12.
Thus, the only significant difference between the marking surface 10 of the present invention and the experimental surface created for comparison purposes was the use of the ink 20 versus use of the primer-paint combination. The sample coated with primer and chalkboard paint weighed 101.3 grams, while the inventive chalkboard marking surface 10 weighed only 55.8 grams. Once the primer-paint treated surface was applied to a vertical wall, it became detached from the wall within about 15 minutes. Contrastingly, the inventive chalkboard marking surface, having the same amount of adhesive, tightly clung to the wall until it was manually removed (i.e., it remained attached indefinitely). Of course, additional adhesive may be utilized to retain additional weight. However, it is desirable to use only as little or as much adhesive as is necessary so that the failure rate is only about a 1% (or less). “Failure” should be understood to include various situations where the marking surface 10 does not adhere as intended. These situations include those where the marking surface 10 strips paint from, for example, a wall to which it is applied when the surface 10 is removed, or where the marking surface 10 becomes detached from a wall due to its own weight.
Although the invention has been described with reference to particular embodiments, it is to be understood that these are merely illustrative of the application of the principles of the invention. Thus, it is to be understood that numerous modifications may be made in the invention and other arrangements may be devised without departing from the spirit and scope of the invention.
This application claims the benefit of prior co-pending U.S. Provisional Patent Application Ser. No. 60/811,915, filed Jun. 8, 2006.
| Number | Date | Country | |
|---|---|---|---|
| 60811915 | Jun 2006 | US |
