The present invention is directed toward removable nonslip foamed surface coverings which are used as rug underlay pads or, alternatively, as shelf, drawer or storage liners. In particular, the covering features an improved composite material having a primary layer of polymeric foam combined to at least one coherent layer consisting of a water-resistant blend of styrene-maleic anhydride and acrylic resin. The structure of the multilayered composite material facilitates the secured and reusable application of the surface covering after repeated washings.
Nonslip foamed surface coverings have been extensively sold at retail venues and are commonly utilized as rug underlay materials or as shelf and drawer liners. One type of nonslip covering consists of a knitted polyester scrim featuring a coating of thermally foamed polyvinyl chloride (PVC) resin. The knitted construction of the scrim provides an arrangement of woven yarns defining a pattern of apertures that correspond to a configuration of openings extending through the thickness of the cured PVC material. Alternatively, the PVC resin may be knife coated to either side of a knitted scrim devoid of openings, or to a non-woven fabric of autogenously bonded fibers, producing a continuous layer of supported foam. The PVC compound also includes a plasticizer that imparts a removable nonslip mechanical bond between the foamed covering and an applied surface. Although thermally foamed nonslip coverings provide a layer of cushioning and surface protection, such unanchored materials require frequent repositioning because they are prone to bunch up or shift through repetitive use.
Another problem with thermally foamed PVC coverings relates to the migration of monomeric and polymeric plasticizers that have been known to cause marring of certain types of underlying surfaces. Such vulnerable surfaces include lacquered or oil-based painted finishes, along with composite wood shelving and furnishings embellished with dry thermal transfer appliqués, which simulate decorative wood grained facings and are made from acrylic or nitrocellulose resins. Plasticizers within foamed PVC compounds may also react negatively with vinyl flooring and wood laminates coated with polyurethane varnishes. In addition, the application of plasticizers within foamed PVC coverings—although useful in providing nonslip properties to such materials—are also known to adversely affect the performance of anchor coatings that are formulated from conventional acrylic and rubber based adhesives.
The primary disadvantage of the prior art, inherent within foamed PVC coverings that feature self-adhesive anchor coatings, concerns the inadvertent disintegration of the material upon removal. For example, U.S. Pat. No. 5,120,587, issued on Jun. 9, 1992 to L. McDermott, III et al., discloses a support binder for carpeting in the form of a scrim having a plurality of alternating spaced frame elements sheathed within a thermally foamed coating of polymeric resin. The foamed binder includes corresponding layers of adhesive to secure carpets and area rugs onto floors or other carpeting. Over time, the cellular structure of the polymeric foam degrades with age, while the self-adhesive anchor coating becomes fully cured to a selected surface. Consequently, replacement of the self-adhesive covering will result in the residual adhesion of miniscule fragments of foam to the underside of carpeting and to subjacent flooring surfaces.
One remedy in the prior art includes the application of an intermediate layer of polymeric film to act as a mechanical barrier between the polymeric foam and the underlying coating of adhesive. The polymeric film provides an increased surface area to enhance the adhesion of the PVC covering and prevents the transfer of residual foam to flooring or to the interiors of cabinets and drawers. For instance, U.S. Pat. No. 7,601,653, issued on Oct. 13, 2009 to S. Price, discloses an adhesive grip liner comprising a foam sheet material which is joined to a layer of vinyl film. The underside of the vinyl is coated with a continuous or imprinted layer of adhesive. Similarly, U.S. Patent Application Publication US 2002/0145089 A1 by M. Calkins, published on Oct. 10, 2002, discloses a protective covering sheet having a scrim-supported foamed PVC working surface, which is adhered to a layer of polymeric film. As in the previous related example, a pressure sensitive adhesive is applied to the reverse face of the polymeric film. In both embodiments, a removable release liner serves as a protective masking to the layer of adhesive. Although the use of release liners enable the efficient packaging of self-adhesive foamed surface coverings, the dissimilar thicknesses of the component layers that make up such materials create an unbalanced laminated construction, thereby causing the inadvertent wrinkling of the finished goods when they are wound into rolls for retail distribution.
The systems, methods, and inventions described in the above-identified patent publications are found lacking in disclosing an improved reusable surface covering material, which is comprised of a layer of polymeric foam combined to a water-resistant layer of coherent resin.
Accordingly, it is a principal object of the present invention to provide an improved multilayered composite material for use as rug underlay pads, or shelf and storage liners, having a resilient layer of polymeric foam combined to an anchor coating of coherent resin that facilitates the secured and reusable application of the surface covering after repeated washings.
It is a further object of the present invention to provide a multilayered composite material having a layer of thermally cured polymeric foam encasing an intermediate reinforcing layer of knitted or nonwoven scrim.
It is an alternate object of the present invention to provide a multilayered composite material having a continuous layer of thermally cured unsupported polymeric foam.
It is another object of the present invention to provide a multilayered composite material having at least one coherent layer composed of a water-resistant blend of styrene-maleic anhydride and acrylic resin.
It is yet another object of the present invention to provide a multilayered composite material having a coherent layer of a styrene-maleic anhydride and acrylic resin that impedes the migration of monomeric and polymeric plasticizers.
It is an additional object of the present invention to provide a multilayered composite material that does not require an integral release coating or separable release liner to protect the layer of coherent resin.
Finally, an object of the present invention is to provide a multilayered composite material having a coherent anchor coating that prevents the adhesion of residual polymeric foam to subjacent surfaces upon removal.
The disadvantages and limitations of the background art discussed above are overcome by the present invention. With this invention, a removable nonslip foamed surface covering is provided, wherein an improved multilayered composite material, having at least one layer of resilient polymeric foam, is combined to at least one layer of a coherent blend of styrene-maleic anhydride and acrylic resin. In a preferred embodiment, the polymeric foam is an expanded polyvinyl chloride (PVC) resin that is thermally cured to a knitted or nonwoven reinforcing scrim. Alternatively, The PVC layer may also consist of a continuous unsupported sheet of polymeric foam. The structure of the multilayered composite material facilitates the secured and reusable application of the covering, even after repeated washings, to a broader range of horizontal and vertical surfaces.
In accordance with the present invention, the primary layer of expanded foam consists of a polymeric compound that includes: a plasticizer; polyvinyl chloride resins; calcium carbonate; a chemical foaming agent; a heat stabilizer; and a pigment. In a preferred embodiment, the plasticizer may be selected from the group of Diisononyl phthalates (DINP), Dioctyl terephthalates (DOTP), Epoxidized Soybean Oils (ESO), or mixtures thereof. The compound is further comprised of a copolymeric blend of two dissimilar PVC homopolymer dispersion resins which respectively exhibit low and medium viscosities. A calcium carbonate powder is additionally used as filler within the polymeric formulation. The PVC copolymeric admixture also contains a chemical blowing agent that is selected from the group of hydrazine derivatives, and is more particularly an Azodicarbonamide powder that is suspended in the resin formulation. Under thermal decomposition, Azodicarbonamide releases nitrogen when exposed to temperatures in the range of 200° to 215° C., thereby causing the expansion of the polymeric composition. To impede the heat-induced deterioration of the compound during processing, Zinc Octoate is used as a stabilizing additive to lower the thermal activation range of the Azodicarbonamide powder. Finally, the PVC foam may be colored with a pigment system that is compatible with the selection of plasticizers used within the polymeric formulation.
The primary layer of expanded PVC foam may comprise a thermally cured formulation that is reinforced with an intermediate layer of knitted or nonwoven scrim. The polymeric suspension may be applied by way of dip coating the reinforcing substrate or, optionally, through a transfer roll coating method in which the compound is meted out from an underlying reservoir. The coated material is then conveyed through an oven to activate the blowing agent and to solidify the composition. Alternatively, the polymeric formulation may be cured by means of a thermal calendering process, wherein the polyvinyl chloride admixture is uniformly coated on a releasable belt or casting paper which is compressed against a heated roller. In the absence of a knitted scrim or non-woven substrate, the releasable belt or casting paper provides support and dimensional stability to the unsupported polymeric compound while maintaining the uniform thickness of the nonslip material during solidification.
The present invention features at least one coherent layer consisting of a water-resistant blend of Styrene-Maleic Anhydride (SMAnh) copolymer and Acrylic resin. SMAnh is a synthetic copolymer that is composed of almost perfectly alternating Styrene (STY) and Maleic Anhydride (MAnh) monomers. The main characteristics of SMAnh, which is achieved through the controlled radical polymerization of STY and MAnh monomers, includes its transparent appearance, high heat resistance, superior dimensional stability, and the specific reactivity of the anhydride groups. Styrene-Maleic Anhydride is also soluble in water-based alkaline solutions and dispersions, and the specific reactivity of the copolymer makes it a suitable agent for compatibilizing normally incompatible polymers. Accordingly, the dispersion of SMAnh copolymer, blended in combination with the suspension of Acrylic resin, functions as an essential crosslinking agent between the coherent anchor coating and the primary layer of PVC foam.
Further objects and advantages of the present invention will be apparent from the following description of the preferred embodiments when considered in conjunction with the accompanying drawings.
Similar reference characters denote corresponding features consistently throughout the attached drawings.
The present invention is a multilayered composite material suitable for use as a rug underlay pad or, alternatively, as a shelf, drawer or storage liner, and generally designated as 10 in the drawings. With reference to
As detailed in
With further reference to
Turning once again to
As further illustrated in
In a similar technique used to produce the primary layer of polymeric foam 11, the coherent layer 12, 120a, 120b, or 220 can be applied according to the method schematically illustrated in
In a preferred embodiment, and as shown in
Even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the preferred embodiments, the above disclosure is illustrative only. Changes may be made in detail, especially in matters of shape, size and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
Number | Date | Country | |
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61683655 | Aug 2012 | US |