FIELD OF THE INVENTION

The present invention relates to a composite polymeric film wear layer. The wear layer of the present invention can be applied as a surface protection layer to impart lower gloss and higher scratch resistance, wear performance and comfort to hard surface substrates.

BACKGROUND OF THE INVENTION

Hard surface substrates such as Luxury Vinyl flooring have a balancing layer at the bottom, a core layer of polyvinyl chloride (PVC) and limestone, a printed layer of PVC, a wear layer of clear PVC, and a top layer coating that is UV curable polyurethane. To meet the need for lower gloss, the top layer coating typically contains silica particles having particle size diameter of about 1 to about 40 microns that act as a matting agent. The coating also has abrasion resistant agents such as aluminum oxide, to resist scratches.

Various coating layers and processes for application to hard surface substrates have been described.

U.S. Pat. No. 8,658,274 discloses a thermoplastic laminate plank with an optional overlay. The overlay or wear layer is an overlay paper, which upon being fixed to the print layer of the plank, is clear in appearance. Listed preferred high abrasive overlays with aluminum oxide embedded in the surface of a paper impregnated with an aminoplast resin for use in this thermoplastic plastic laminate plank include those from Mead Specialty Paper with the product numbers TMO 361, 461 (70 grams/m2premium overlay from Mead), and 561.

U.S. Pat. No. 9,156,233 discloses waterproof engineered floor and wall planks with a wear layer bonded to the core via a water-resistant adhesive. The wear layer is disclosed as waterproof and is selected from a number of possible materials including tile or stone veneer, rubber, decorative plastic, decorative vinyl, linoleum and any material such as cork, bamboo or wood veneer encapsulated in vinyl or resin to render the layer waterproof and wear resistant. An optional cover layer applied over the veneer of melamine resin with aluminum oxide and polyurethane is also disclosed.

U.S. Pat. No. 8,800,245 discloses a piece for flooring which includes a PVC wear layer, a pattern layer, a base layer, and a backing layer.

Published U.S. Patent Application No. 2015/0375471 discloses tiles for use in ceilings, walls, and floors, with a wear layer that comprises any suitable known abrasion resistance materials such as abrasion resistance macromolecular material coated on the layer beneath it, or a known ceramic bead coating. Alternatively, the wear layer may comprise an organic polymer layer and/or an inorganic material layer such as an ultraviolet coating, or a combination of another organic polymer layer and an ultraviolet coating. A disclosed example is an ultraviolet paint capable of improving the scratch resistance, glossiness, antimicrobial resistance and other properties of the product. Additional agents disclosed for inclusion as needed include organic polymers, polyvinyl chloride resins and vinyl resins, plasticizing agents and other processing additives.

U.S. Pat. No. 4,176,210 discloses a decorative sheet-type covering material having both PVC and polyurethane wear layers made by forming a sheet of gelled, foamable PVC plastisol or organosol on a substrate, and then applying and gelling, but not curing, a layer of nonfoamable PVC plastisol or organosol to the gelled, foamable layer. A layer of polyurethane is then applied to the gelled nonfoamable layer, and the entire sheet is heated to a temperature sufficient to decompose the blowing agent in the foamable layer and cure both the PVC layers and the polyurethane layer.

European Patent No. 2 424 911 discloses ultraviolet (UV) V spectra light emitting diode curable coatings for flooring and other applications to enhance their durability and finish.

PCT/US2008/071446 discloses a floor plank comprising a first sheet having at least one base layer, a print design located above the base layer, and at least one wear layer located above the print design and a second sheet adhered to the lower surface of the first sheet, wherein the two adjacent sides of the second sheet have projections to interlock with projections from an adjacent floor plank with complementary shape to each other to be interlockingly engageable with corresponding projections or recesses on adjacent floor planks. A disclosed preferred wear layer is a transparent PVC layer from about 5 mils to about 50 mils. Other examples of wear layers disclosed include acrylic polymers, polyolefins, and the like. Further, it is disclosed that the wear layer topcoat can be a thermoset layer or thermoplastic layers. Additional examples of wear layers are disclosed in U.S. Pat. Nos. 4,333,987; 4,180,615; 4,393,187; 4,507,188; and 8,591,696 and published U.S. Patent Application No. 2016/0201324.

However, these types of coatings result in several negatives. For example, when the surface is scratched using a Martindale scratch tester with 100 grit sand paper for 45 cycles, it generates a white powder of silica and polymeric dust and abrasion agent from the coating that is undesirable and concerning to consumers. Further, these coatings are expensive as, for example, the industry standard manufacturing process must include a line for substrate coating, complete with UV lamps and optional thermal annealing. In addition, there is potential for the coating to crack or fail, due to poor adhesion, thus creating unnecessary waste.

Similar issues exist in wood flooring, with as many as nine coating layers, with a top coat made up of UV curable polyurethane.

In addition, hard surfaces are known to be uncomfortable under foot compared to soft surfaces such as rugs and carpets. Standing for long times on hard flooring results in more fatigue and could result in pain at joints. Home owners have tried to solve this problem by using soft gel mats over hard surfaces in kitchens and other locations where they need to stand for long times. Underlayment backings below the core substrates do not help in this regard.

Protective layers for hard substrate surfaces which minimize or eliminate white powder generation due to scratching, and eliminate expensive coating chemistry and the additional process step of applying the coating are thus a long-felt need. Further, there is need to have a softer and more comfortable feel under the feet for hard surfaces while preserving existing advantages such as design and looks, and easy to install click lock joints.

SUMMARY OF THE INVENTION

An aspect of the present invention relates to a composite polymeric film wear layer for hard surfaces.

In one nonlimiting embodiment, the composite polymeric wear layer comprises a bottom polymeric layer comprising a polymer and matting agents dispersed therein, and a top polymeric layer comprising a polymer and a plurality of abrasion resistant particles. In some embodiment, the top layer further comprises a matting agent to lower gloss. In some embodiments, in between the bottom polymeric layer and the top polymeric layer is a middle polymeric layer.

In another nonlimiting embodiment, the composite polymeric wear layer comprises a bottom polymeric layer comprising a polymer and matting agents dispersed therein, and a clear transparent polymeric layer, and a top polymeric layer comprising a polymer and a plurality of abrasion resistant particles.

In another nonlimiting embodiment, the composite polymeric wear layer comprises a bottom polymeric layer comprising a polymer and matting agents dispersed therein, and a top polymeric layer comprising a polymer and a plurality of abrasion resistant particles. These two layers can have a Shore A hardness rating of 50 to 100. In this nonlimiting embodiment, between the bottom polymeric layer and the top polymeric layer is a clear and transparent middle polymeric layer which is softer and has a Shore OO Hardness rating of 20 to 100. This provides comfort under foot when this layer is mounted on a hard surface core. This composite layer can be mounted on top of a print layer which in turn is mounted on a core substrate or mounted on a digitally printed core substrate to create flooring.

In another nonlimiting embodiment, the composite polymeric wear layer comprises a bottom polymeric layer comprising a polymer and matting agents dispersed therein, and a top polymeric layer comprising a polymer and a plurality of abrasion resistant particles. In this nonlimiting embodiment, the bottom polymeric layer can be reverse printed to provide design. These two layers can have a Shore A hardness rating of 50 to 100. Underneath the bottom layer is a polymeric layer which is softer and has a Shore OO Hardness rating of 20 to 100. This may or may not be transparent. This composite layer can be mounted on top of a hard substrate core to create flooring.

Another aspect of the present invention relates to hard surface flooring. In one nonlimiting embodiment, the hard surface flooring comprises a bottom balancing layer, a core layer on top of the bottom balancing layer; a decorative or print layer on top of the core layer; and a composite polymeric wear layer of the present invention. In one nonlimiting embodiment, the bottom balancing layer, the core layer and the decorative or print layer of the hard surface flooring comprise polyvinyl chloride. In another nonlimiting embodiment, the bottom balancing layer, the core layer and the decorative or print layer of the hard surface flooring comprise nonvinyl polymers. In yet another nonlimiting embodiment of this hard surface flooring, the bottom balancing layer comprises wood, the core layer comprises a core platform, and the decorative or print layer comprises a wood veneer.

Another aspect of the present invention relates to a hard surface substrate comprising a core substrate and a composite polymeric wear layer of the present invention. Nonlimiting examples of core substrates that can be protected via the present invention include packaging film, countertops, and furniture.

Another aspect of the present invention relates to a method for protecting a surface of a hard surface substrate from scratching by applying the composite polymeric wear layer of the present invention to the hard surface substrate.

Yet another aspect of the present invention relates to a method for imparting lower gloss to a surface of a hard surface substrate by applying the composite polymeric wear layer of the present invention to the hard surface substrate.

