BACKGROUND OF THE INVENTION In the current floor covering market there is generally increasing demand for durable floor covering articles, particularly durable rugs. For instance, rugs and bath mats used in institutions such as hotels and healthcare facilities are subjected to frequent laundering at high temperatures. Typically, these rugs are backed with a latex material containing a blend of natural rubber and styrene butadiene rubber (SBR), referred to as either"natural/SBR latex"or as "standard latex."Over repeated washings, the combined effect of excessive handling and high washing and drying temperatures results in yellowing of the standard latex rug backing. After about twenty-five washings, the aesthetic appearance of the backing material of most rugs or bath mats is significantly diminished. After a greater number of washings, the latex degrades, resulting in cracking and crumbling of the rug backing.

It would be desirable if a rug were available having a more durable backing than known rug backings, that would maintain an acceptable appearance after being subjected to a high level of handling and laundering. It would further be desirable to have a process for making a rug having a durable backing without the need for modifications to standard equipment currently used for making rugs.

SUMMARY OF THE INVENTION The invention provides a floor covering article comprising a fabric having an upper surface and a lower surface, pile yarns forming a pile surface projecting from and covering the upper surface of the fabric, and a coating on the lower surface of the fabric to secure the pile yarns to the fabric, the coating comprising a blend of natural rubber and neoprene rubber. The fabric is preferably a tufted fabric, but may be any other fabric type useful as a floor covering article, such as velour, woven, non-woven, knitted, flocked, stitch-bonded, needle-punched or fusion-bonded.

In another aspect the invention is directed to a process for making a floor covering article comprising coating the lower surface of a pile fabric with a coating comprising a blend of natural rubber and neoprene rubber.

DESCRIPTION OF THE DRAWINGS The invention will be more fully understood from the following detailed description, taken in connection with the accompanying drawings, in which: Figure 1 is a perspective view of a floor covering article in accordance with the present invention; and Figure 2 is a schematic representation of the steps of a process for making the floor covering article of the present invention.

DETAILED DESCRIPTION OF THE INVENTION Throughout the following detailed description, similar reference numerals refer to similar elements in all figures of the drawings.

The floor covering article generally indicated in Figure 1 by reference character 10 comprises a fabric 12 having an upper surface 12A and lower surface 12B, a pile surface 14 of pile yarns 14P projecting from the upper surface 12A of the fabric 12, and a

coating 16 disposed on the lower surface 12B of the fabric 12. In accordance with the present invention, the coating 16 is formed of a blend of natural rubber and neoprene rubber. The pile yarns 14P are preferably tufted into the fabric 12.

The pile yarn 14P is preferably polyamide, and more preferably bulked continuous filament polyamide.

The pile yarn 14P may also be polyolefin, polyester, cotton, acrylic or wool. The yarn must be able to withstand the temperature of the coating and curing operations of the coating 16 without melting or degrading. The temperature at which the coating is cured may need to be reduced and/or the curing time extended if cotton or polyolefin yarn is to be used as the pile yarn 14P, as cotton and polyolefin yarns degrade or melt at lower temperatures than other fibers conventionally used in floor covering articles.

The pile yarn 14P may be a white dyeable yarn or a producer-colored (or"solution-dyed") yarn. An advantage of using producer-colored yarns is that such yarns have inherently better bleach resistance than dyed yarns, so that rugs made therewith maintain better appearance after laundering with bleach than do rugs made with dyed yarns. This is an important feature for rugs used in health care facilities, since bleach is commonly used to clean the wide variety of spills and stains occurring there.

The natural rubber used in the coating 16 is of the same type as is commonly used in standard latex rug backing. The amount of neoprene rubber present in the coating 16 may vary greatly and still afford the benefits of a more durable rug backing. Generally, it has been found that the more neoprene present, the more durable the coating 16 will be, although the relative amounts of neoprene and natural rubber may vary according to the end use requirements of the rug. It has been found that a coating consisting of one-hundred percent (100%) neoprene rubber can not be embossed and

changes color undesirably after repeated washings and dryings, so that some natural rubber must be present.

For most rug applications the amount of neoprene rubber in the coating should vary between ten percent (10%) and eighty percent (80%), based on the weight of the coating. For institutional or industrial rugs, such as bath mats for hotel rooms and health care facilities, the coating 16 will contain between fifty percent (50%) and eighty percent (80%) neoprene rubber, based on the weight of the coating. For more demanding end uses, the coating 16 will contain between seventy percent (70%) and eighty percent (80%) neoprene rubber, based on the weight of the coating. For residential use, it is possible to reduce the neoprene content to between ten percent (10%) and fifty percent (50%) and still maintain a high level of durability.

It is understood that the composition of the coating 16 may also contain conventional latex additives, including soaps, antioxidants, jelling agents, pigments (e. g., Ti02) and filles, and certain vulcanization additives to aid the drying and curing process. The vulcanization additives may include accelerators, including zinc and sulfur.

To prepare the coating 16, the latex additives are combined and the vulcanization additives are separately combined, as is standard practice in the carpet and rug making industry. Prior to the application of the coating 16 to the lower surface 12B of the pile fabric 12, all components are mixed with the natural rubber and the neoprene rubber in a storage tank from which the mixture is pumped to the coating system.

The coating 16 is applied to the lower surface 12B of the fabric 12 in the form of a foam by a foam application system 22 as shown in Figure 2. The coated fabric 10 is passes a doctor blade 24, which levels the coating 16 and ensures that the coating is applied at a uniform thickness over the entire surface 12B. Other

methods (not shown) of applying the coating 16 may be used, such as spraying the coating onto the lower surface 12B of the fabric 12. In order to spray the coating, the coating viscosity must be lower than when applied as a foam. The viscosity of the coating 16 may be lowered by reducing the amount of fillers present in the natural rubber.

The coating 16 is applied to the lower surface 12B of the pile fabric 12 in an amount sufficient to impart the desired durability to the resulting rug 10.

This amount will vary with the specific coating composition used and the durability requirement of the rug. For instance, when the coating 16 is a blend of fifty percent (50%) natural rubber and fifty percent (50%) neoprene rubber and when the rug must maintain its appearance after 60 industrial washings, the preferred weight of the coating 16 is between twenty- four (24) and twenty-six (26) ounces per square yard.

If the amount of the coating 16 is insufficient, adhesion to the fabric 12 is poor and the coating may be rubbed off easily.

After passing the doctor blade 24, the coated fabric 10 is optionally passed through a set of embossing rolls 26A and 26B. Embossing rolls are used when the rug backing is intended to have a skid- resistant relief pattern thereon, typically in the form of a basket weave or decorative pattern. This is accomplished by passing the coated fabric under pressure through the rolls 26A and 26B, one of which has a pattern in the surface thereof. Embossing the coating 16 also increases the level of"tuft bind," meaning the degree to which the coating material encapsulates and binds the pile yarns 14P on the lower surface 12B of the fabric 12.

The embossing step is omitted when the rug backing (the lower surface of the coating 16) is intended to be completely smooth.

The coated fabric 10 is forwarded to a drying oven 28 in which the coating 16 is dried and cured, according to standard practice in the rug making industry. The fabric 10 is then typically pulled by take-up rolls and wound onto a roll for further handling.

TEST METHODS Subjective Rating A rug backing is examined visually and given one of the following ratings: "Okay"-No visible wear, appearance is very close to that of the control "Mild"-Some abrasive wear visible "Moderate"-More abrasive wear visible "Failed"-Primary backing is visible, or at least three pinholes are visible in the backing "Separated"-Backing visibly puckered or pulled away from primary backing EXAMPLES Rugs were tufted using 1100 denier, producer- colored bulked continuous nylon multifilament yarn as the pile yarn, each filament having a denier of eight (8). Each filament had a trilobal cross-section with a modification ratio of 2.8. The rugs were tufted according to the following specifications: cut pile, 1/8 inch gauge, thirty-three (33) ounces per square yard weight, 11/16 inch pile height, 8.5 stitches per inch.

The rugs were passed through the coating operation at a line speed of twenty (20) feet per minute, under three hundred fifty (350) pounds of pressure by a doctor blade.

The coatings applied were blends of neoprene rubber and natural rubber, along with latex and vulcanization additives. Latex 654, commercially

available from DuPont Dow Elastomers, L. L. C., Wilmington, Delaware, was used as the neoprene rubber.

The natural rubber used was a generic rubber, commercially available from latex compounders.

The coated rug was then passed under pressure between a set of two embossing rolls, one of which having a"basket weave"or"waffle"relief pattern in its surface.

The rug was passed through a drying oven at three hundred ten (310) degrees F.

The control rug (example number 18) was made using a white dyeable pile yarn, having the same denier, denier per filament, cross-section and tufted weight as the examples, a rug was made to the above rug specifications, with twenty-four (24) ounces per square yard weight of natural/SBR latex backing.

Table 1 lists the rugs made, and indicates for each rug whether the yarn is dyeable or producer- colored, the weight of the tufted rug, the ratio of neoprene to natural rubber in the coating, and the weight of the coating.

Table 1 Example Yam type: Dveable Tufted weight. Ratio of neoprene Weight of Weight of or Producer-ounces per to natural rubber coating, ounces neoprene, colored square yard per square yard ounces per square yard 1 Dyeable 32 70: 30 19 13 2 Producer-colored 32 70: 30 20 14 3 Dyeable 36 70: 30 20 14 4 Producer-colored 36 70: 30 20 14 5 Dyeable 32 50: 50 20 10 6 Producer-colored 32 50: 50 20 10 7 Producer-colored 36 50: 50 22 11 8 Dyeable 36 50: 50 20 10 9 Producer-colored 36 50: 50 16 8 10 D eable 36 50: 50 26 13 11 Producer-colored 36 50: 50 22 22 12 Producer-colored 32 50: 50 27 13.5 13 Dyeable 32 50: 50 23 11.5 14 Producer-colored 32 70: 30 31 21 15 Dyeable 32 70: 30 24 16 16 Dyeable 36 70: 30 26 18 17 Producer-colored 36 70: 30 26 18 18 Dyeable 32 0: 100 (100% 24 0 (Control) standard latex)

Dyeable and producer-colored rug data are herein separated because, in general, rugs made from producer-colored yarns are subjected to treatment with bleach and rugs made from dyeable yarns are not subjected to treatment with bleach.

Table 2 indicates the performance of each rug made using dyeable yarn after an increasing number of washings.

Table 2 Number of Washings- Ex Oun 10 20 30 40 50 60 ZQ 80 90 100 ces neoo rene 1 13 OK Mild Mod Mod Mod Failed 3 14 OK Mild Mild Mild Mild Mild Mild Mod Mod Mod 5 10 OK OK Mild Mild Mod Mod Failed 8 10 OK OK Mild Mild Mod Failed 10 13 OK OK OK Mild Mild Mild Mild Mod Mod Mod 13 11.5 OK OK OK Mild Mild Mild Mod Failed 15 16 OK OK Mild Mild Mild Mod Mod Mod Mod Mod 16 18 OK OK OK Mod Mod Mod Mod Mod Mod 18 o OK OK Failed

Table 3 indicates the performance of each rug made using producer-colored yarns after an increasing number of washings including an increasing number of washings in which bleach was added. The number of washings includes the number of washings with bleach.

Table 3 Ex Ounces 10 wash 20 wash 30 wash 40 wash 50 wash 60 wash 70 wash 80 wash neoorene 1 5 10 15 25 35 45 55 bleach bleach bleach bleach bleach bleach bleach bleach 2 14 OK Failed 4 14 OK Failed 6 10 OK Failed 7 11 OK Failed 9 8 OK Mild Mod Mod Mod Mod Failed 11 22 OK Mild Mild Mod Mod Mod Mod Failed 12 13.5 OK Mild Mild/Mod Mod Mod Failed +Sep Mod 14 21 OK Mild Mild/Mod Mod Failed +Se Mod 17 18 OK OK Mild Mod Mod Mod Failed 1

The results generally indicate that the higher the level of neoprene in the rug backing composition, the more washings the rug backing is able to withstand (Tables 2 and 3), and the more washings with bleach the rug backing is able to withstand (Table 3). It is noted that Examples 12 and 14 failed prematurely as a result of the coating having separated from the primary backing. This separation indicates a poor quality coating operation.

The backing performance does not appear to depend on fiber type (i. e., dyeable or producer- colored).