The protective coatings currently used on commercially-available wall coverings adequately protect the underlying PVC sheet, including its fanciful design, from damage and abuse. Nonetheless, it is still difficult to remove certain types of markings from such products. For example, markings made from crayon, ink, paints and other materials often found in homes with children are often difficult to remove. That is why children in most homes are encouraged, in the strongest of terms, not to write on the walls.

Summary of the Invention Against this background, the present invention provides a new, decorative vinyl wall covering for use in decorating walls found in homes and other structures which is specifically designed to be writable and erasable.

This new, write-on/wipe-off wall covering takes the form of an elongated sheet composed of a continuous sheet of flexible plastic material having essentially the same size

and shape as conventional vinyl wall coverings. The front face of this continuous sheet bears a decorative design of the same type as conventional wall coverings, and a protective covering is also applied to this front face to prevent it from being damaged or destroyed. However, in the case of the present invention, this protective coating is formed from a fluorocarbon polymer that is dry erasable-- i. e., it can be easily erased with a suitable dry eraser when marked with a dry erasable ink.

With this structure, the inventive wall covering can be used in the same way as conventional wallpaper or other wall covering to provide a fanciful, decorative design covering some or all of the walls of a child's bedroom, for example. However, in this room, the child can be allowed or even encouraged to mark up the"covered"walls with his/her own designs, preferably using a dry erasable marker provided by his parents for this purpose, since these marks can be easily removed whenever desired. Similarly, the inventive wall covering can also be used by adults in a variety of different applications such as office areas, board rooms, conference rooms, near desks, in hallways or meeting areas, etc. Because the inventive wall covering is so easy to clean, individuals can"write on"its decorative design and then"wipe off"the notes/comments/drawings etc. so written without disturbing or destroying the design aesthetics of the wall covering itself.

Brief Description of the Drawings The present invention may be more readily understood by reference to the following drawings wherein: FIGURE 1 is a schematic cross-section illustrating the structure of a preferred write-on/wipe-off wall covering made in accordance with the present invention; FIGURE 2 is a schematic view illustrating two sections of wall covering of the present invention mounted on a wall in side-by-side relation, the two sections being separated from one another in the figure for illustrative purposes; and,

FIGURE 3 is a schematic view similar to FIGURE 2 illustrating another wall covering of the present invention having a different design than the wall covering of FIGURE 2.

Detailed Description FIGURE 1 shows an example of the write-on/wipe-off wall covering of the present invention generally indicated at 10. The wall covering 10 is formed from a continuous sheet 12 of plastic material, preferably a polyvinyl chloride homopolymer or copolymer resin. A front face 14 of the continuous sheet 12 carries discrete markings or areas of single or multiple colors, hereinafter"indicia"16, typically formed by printing which, in the aggregate, form a decorative design on the front face 14 of the sheet 12. A protective coating 18 is bonded to the front face 14 to protect the continuous sheet 12 including the indicia 16 thereon. An optional backing layer 20 is bonded to the rear face 22 of the continuous sheet 12 to impart dimensional stability to the overall product, when desired.

The inventive wall covering 10 is intended to be a replacement for, and to be used in the same way as, conventional vinyl wall coverings. Therefore, the wall covering 10 is made to have essentially the same size, shape and flexibility as conventional vinyl wall covering. Thus, the wall covering 10 typically takes the form of an elongated sheet 0.30 to 0.91 meters, more typically 0.61 to 0.69 meters, wide for residential use and 0.10 to 0.76 millimeters thick, preferably 0.20 to 0.56 millimeters thick. For commercial use, such as in businesses, hospitals, hotels, convention centers and the like, the inventive wall covering can be made any conventional length and width such as 1.35 to 1.42 meters wide and 24.4 to 30.5, preferably 27.4, meters long. Like conventional wall coverings, the inventive wall covering is intended to be supplied to the consumer in "rolls,"with"single rolls"having about 2.79 to 3.71 square meters of material and being about 4.57 to 7.62 meters long and"double rolls"containing about 5.57 to 7.43 square meters of material and being about 9.14 to 13.7 meters long. For

commercial use, rolls having on the order of 37.6 square meters of material, or any other convenient amount, can be used.

In the particular embodiment shown, the continuous sheet 12 is formed from polyvinyl chloride, optionally filled with a suitable material to provide opacity and a base color.

Alternatively, the continuous sheet 12 can be unfilled for allowing transparency. Other conventional materials used for forming wall coverings can be used in place of the polyvinyl chloride.

In the particular embodiment shown, the backing layer 20 is composed of a web of flat, woven polyester fibers, the web being bonded to the rear face 22 of the sheet 12 using a PVC plastisol. The web forming backing layer 20 can be made form other materials such as cotton, a mixture of cotton and polyester fiber or other materials, and it can be a non-woven fabric or the like. The backing layer 20 can also be made from a continuous sheet rather than a foraminous web, if desired.

The indicia 16 are provided on the front face 14 of sheet 12 by printing in a conventional manner. The indicia 16 have a different color form the color of the sheet 12 so that the indicia 16, in the aggregate, form a fanciful design on the front face 14 of the sheet 12. Preferably, different indicia 16 have different colors so that a multi-colored design is produced. The fanciful design formed by the indicia 16 can take essentially any form. It can be definite in its composition in the sense that it defines a picture or likeness of something, letters, numbers, outlines of information, games such as tic tac toe, etc. It can also contain information for specific uses, such as multiplication tables for schools, graphs, business slogans, mottoes, business forms, etc. Alteratively, the design can be random in form such as a stucco design. The design can also be regular, free form in its composition such as a weave pattern or stripes. In addition, the indicia 16 may also be provided on the front face 14 of the sheet 12 by embossing in the

conventional manner to impart a degree of texture or an aesthetically pleasing textured pattern to the sheet 12.

FIGURE 2 illustrates two sections of wall covering taken from a roll of the inventive wall covering, one section marked A and the other marked B, these two sections being mounted on a wall in side-by-side relation. As shown in this figure, a design D is formed by indicia 16 in a rectangular area of the wall covering, design D having a top 24, a bottom 26, a length L and a width corresponding to the width of the wall covering itself. As also shown, design Di repeats itself a number of times in the longitudinal direction of the inventive wall paper in a conventional manner. Typically, design D repeats itself at least ten times, more typically, at least twenty times, over the length of a"single roll"of the inventive wall covering. Also as typical, the length L of the design is preferably chosen so that the design repeats itself in the longitudinal direction an integral number of times, e. g. six to ten times, in the standard height of most dwelling rooms, 2.44 meters.

As further shown in FIGURE 2, design D is so formed that the left side of the design forms a complementary match with the right side of the design. Specifically, indicia 28 in the upper left hand corner of design D forms a complementary match with indicia 30 in the upper right hand corner of design D,. This means that when the adjacent section B of the wall covering 10 is placed contiguous to the first section A so that the right side of design D matches the left side of design D2, the top 62 of design D2 registers exactly with the top 24 of design D in section A.

Specifically, indicia 40 in the upper left hand corner of design D2 registers exactly with indicia 30 in the upper right hand corner of design D1, while indicia 42 in the lower left hand corner of design D2 registers exactly with indicia 44 in the lower right hand corner of design D1.

FIGURE 3 illustrates another example of the inventive wall covering which is similar to that of FIGURE 2, except that its design is different. In particular, design Q in this wall covering is so made that the top 56 of design

Q1 in section X does not register with the top 58 of design in section Y when the right side of design Q, matches the left side of design Q2 Rather, sections X and Y are offset by a distance M representing one-half of the length L of design Q in order that the left and right sides of the design in adjacent sections match. In any event, it can be seen that in both embodiments of the present invention as shown in FIGURES 2 and 3, contiguous sections of the wall covering 10 when properly aligned on the wall form a continuous pattern of the wall covering's decorative design repeating itself across the wall.

In another embodiment of the invention, the individual sections of wall covering taken from a roll of the inventive wall covering, such as sections A and B in FIGURE 2, are arranged on a wall horizontally rather than vertically as shown in FIGURES 2 and 3. This arrangement eliminates vertical seams form by adjacent sections of wall covering, which is beneficial where the inventive wall covering 10 is intended to be marked by writing words or the like in a conventional manner.

Referring again to FIGURE 1, protective covering 18 is made form a fluorocarbon polymer which is dry wipeable.

"Dry erasable"or"dry wipeable"surfaces are known. These surfaces are typically formed from fluorocarbon polymers so formulated that a solvent-based ink, capable of drying to a powder after it has been applied to the surface, can be removed by wiping with a dry eraser or cloth. The ink, after it dries, will adhere to the dry erasable writing surface for a long period of time without significant degradation, but can be readily and easily removed by simple wiping. See, for example, U. S. Patent No. 5,361,164, the disclosure of which is incorporated herein by reference.

A number of different fluorocarbon polymers are known which will form writable/dry wipeable surfaces.

Examples include polymers and co-polymers which contain one or more polymerized monomers selected from the group consisting of tetrafluoroethylene (TFE), chlorotrifluoroethylene (CTFE), vinyl fluoride (VF),

vinylidene fluoride (VDF) and hexafluouropropylene (HFP).

Preferred polymers and co-polymers are those containing at least 50% by weight TFE, CTFE, VF, VDF, HFP or mixtures thereof. Preferred polymers are poly- ethylene/tetrafluoroethylene (poly ETFE), poly- ethylene/chlorotrifluoroethylene (poly ECTFE), poly- tetrafluoroethylene (poly TFE), poly-vinyl fluoride (poly-VF) and poly-vinylidene fluoride (poly-VDF). Especially preferred polymers are co-polymers containing at least 50% by weight VDF, especially VDF/HFP copolymers. An especially preferred polymer is sold by Elf-Autochem North America Inc. of King of Prussia, Pennsylvania, in the United States under the designation of Kynar 2800. Other examples of suitable writable/dry wipeable fluorocarbon polymers are disclosed in U. S. Patent Nos. 4,746,576 and 3,922,457, the disclosures of which are incorporated herein by reference.

Particular commercially available polymers which are useful in forming the protective covering 18 are ACLAR (available from Allied Signal Corp. and believed to be a chlorotrifluoroethylene copolymer), KORTON-K 720 (available from Norton/Allied and believed to be a polyvinylidene chloride polymer), and KYNAR 730 (available form Autochem North America and believed to be a polyvinylidene chloride homopolymer).

The thickness of the protective layer 18 can vary widely and any suitable thickness can be employed so long as the protective function of this layer is retained. Also, the protective layer 18 can be made with a matte finish so as to give a dull, non-glare surface appearance or with a"polished" finish to give a high gloss surface appearance. The inventive wall covering 10 is preferably made by laminating the protective coating 18 onto the continuous sheet 12 after it has been printed and/or embossed with the indicia 16. For this purpose, a film formed form the fluorocarbon polymer and having a thickness of approximately 0.005 to 0.051, preferably 0.008 to 0.025 millimeters, more preferably about 0.013 millimeters, has been found suitable. If desired, an

adhesive can be used to increase the bonding strength of the protective coating 18 to the continuous layer 12.

In this regard, adhesives capable of bonding fluoropolymers to other surfaces are known and commercially available. The chemical compositions of many of these adhesives are proprietary, and in the particular embodiment shown herein, a proprietary adhesive of unknown composition was employed. Also, the surface of the protective coating 18 can be treated to enhance its adhesion to the continuous sheet 12, with or without adhesive. Corona discharge and other treatment techniques are well known in the art for enhancing the bonding strength of fluorocarbon and other polymer films to substrates. Any of these techniques can be used in accordance with the present invention to increase the bonding strength of the protective coating 18 to the continuous layer 12.

In a particular embodiment illustrating the present invention, Kynar 2800 fluorocarbon resin obtained from Autochem North America was in the form of a sheet 1.52 meters wide and 0.008 millimeters thick was laminated to a formulated PVC sheet containing vinyl chloride resin, a filler, a plasticizer, a colorant and a stabilizer. The composite so formed was tested by marking with a number of commercially available markers including Sharpie, Major Accent, Berol, Mighty Mark, Avery Dennison and Carter pens.

The marks made by these pens were all removed using liquid cleaner. The composite was also marked with an Expo marker (manufactured by Sanford) and the mark so made was dry erased after four days exposure. This demonstrates that marks made by conventional markers can be easily removed using liquid cleaners, while dry erasable inks can be readily dry erased from this composite.

The inventive wall covering 10 can be used in the same way as conventional decorative wallpaper or other wall covering. For example, it can be used to cover all of the walls of a room, half the walls or only some of the walls, such as all of one wall only or the top half of one or more walls, etc. Like conventional wall coverings, the inventive

wall covering 10 serves a decorative function in that it imparts a pattern of its decorative design over the entire wall area it covers. However, the inventive wall covering 10 also provides a marking surface over all of the area it covers which can be readily marked and easily erased with dry erasers or liquid solvents. This enables the walls of a room to be purposely used as a writing/marking surface even though they have been decorated with the fanciful, decorative designs previously available only in expensive commercial wall coverings. Thus, the inventive wall covering 10 can be used not only as a decorative device in the manner of conventional wall coverings, but also simultaneously as an instructional and/or informational tool for proving suitable information for a variety of different purposes.

Although only a few embodiments of the present invention have been described above, it should be appreciated that many modifications can be made without departing form the spirit and scope of the present invention. All such modifications are intended to be included within the scope of the present invention, which is to be limited only by the following claims.