COMPOSITIONS AND METHOD FOR RENEWING A FLOOR

Abstract: Old, embossed vinyl floor coverings, which may contain asbestos and the like, can be renewed within one working day, without replacement, by applying a leveling composition to the old floor covering prior to installing a new floor covering over the old. The embossing inherent in the old covering is not telegraphed into the new floor covering.

Description: COMPOSITIONS AND METHOD FOR RENEWING A FLOOR FIELD OF THE INVENTION This invention is in the field of floor coverings. More particularly, it relates to compositions and methods for renewing or restoring an old floor, especially old resilient floor coverings, e.g., of the embossed vinyl type, which contain noxious materials, such as asbestos. The art of floor coverings has experienced a number of advances. After walking on wooden floors and area rugs for years, the introduction of asphalt-based linoleum made it possible for many families to install relatively durable, decorative, wall-to-wall' floor coverings for the first time. Various other resins have now largely supplanted the asphalt, and vinyl tile and sheet flooring represents the state of the art. The application of plastiεol coating technology has permitted a number of refinements, including the addition of embossing to enhance the decorative appeal of the flooring. In the manufacture of resilient embossed vinyl sheet, an;, other materials for use as floor coverings., it is common practice to apply various coating layers and processing steps sequentially to a moving web, beginning with a backing. The backing may be predominately a woven fabric, paper, felt, etc. , but for many years it was the industry practice to incorporate asbestos into the backing. Today there are in use many floors covered with such asbestos-containing products, which are either worn out and should be replaced, or need to be replaced for aesthetic reasons. Replacement of an old, worn out resilient floor covering can be effected by peeling the old sheet material from the floor, cleaning the underlying floor, and applying a new floor covering. However, in removing the old floor covering, there is a danger that some of the asbestos may be liberated, with as yet unknown environmental consequences. Whereas one solution to the environmental problem is to simply encapsulate the old flooring with its noxious component •by applying a new floor covering over the old, if the old flooring is embossed there is an added complication; the embossed pattern present in the old flooring may be telegraphed into the new resilient floor covering, an aesthetically unacceptable result. It is to these problems that this invention is directed, and a new floor leveling composition, containing a polymer-modified cement, is a key element in solving them. REPORTED DEVELOPMENTS A polymer-modified cement is disclosed in U.S. Parent 3,947,398 for use in flooring applications, including underlayment for tiles. That is, gypsum plaster is modified by adding to the gypsum a resin latex containing vinyl, acrylate, or methacrylate resins. The two-part composition is mixed prior to application and is said to be self-leveling. The resin is not chemically reactive in the composition. U.S. Patent 4,108,813 describes a cementitious floor covering composition containing Portland cement, a resin emulsion and spherical quartz sand. Although a wide range of resins is disclosed as being useful, resins which are chemically reactive in the composition are not included. A self-leveling flooring composition containing gypsum cement, Portland cement, sand, and water is disclosed in U.S. Patent 4,159,912; no polymeric constituent is included. SUMMARY OF THE INVENTION In one aspect, this invention provides a leveling composition which is applied to the old floor covering and forms an interface between the exposed surface of the old floor covering and the backing of a new floor covering. The leveling composition is selected such that any embossed pattern in the old floor covering is not telegraphed into the new floor covering and so that, when the new floor covering is peeled from the floor, the leveling composition adheres preferentially to the new floor covering. Although the leveling composition is advantageously employed over an old, embossed vinyl floor covering, it may also be employed over non-embossed floor coverings, and over floor coverings which are other than vinyl, e.g., over ceramic tile and resilient tile, such as vinyl, asbestos, and vinyl/asbestos tile, and over strip wood flooring. In another aspect, this invention provides a method for safely renewing an old floor covering which may contain noxious material. In yet a third aspect, this invention provides a floor covering per se, which includes both the old and the new floor coverings. It will be noted the leveling composition of. this invention, which includes a polymer-modified cement, a modified acrylic resin latex, and water, is a key element in each aspect. In addition to the attributes set forth above, the leveling composition of this invention is readily applied over the old flooring and, within a short period of time, the new floor covering can be applied over the hardened composition. Thus, in a single working day, an old floor covering can be renewed. In contrast to the aforesaid floor covering compositions described in the prior art, the leveling composition of this invention includes resin which is chemically reactive and cures in the composition. DETAILED DESCRIPTION OF THE INVENTION The leveling composition of this invention includes, as an inorganic component, a high-hydrate Portland or calcined gypsum cement. The cement is combined with an organic polymeric material, e.g., an ethylene/vinyl acetate copolymer. The resultant polymer-modified cement contains between about 2 and about 10 percent by weight of the organic polymeric material and may also contain a small amount of a dispersing agent, such as sodium citrate, for example. Because of its reactivity with water, the polymer-modified cement is stored in a dry state prior to its incorporation into the leveling composition. Additionally, the leveling composition of this invention includes an acrylic resin which has been modified to contain chemically reactive functional groups, e.g., epoxide groups or precursors thereto which give rise to such functional groups in the composition. The reactive groups serve to cure the acrylic resin, e.g., by cross-linking it. The curing may be effected, or the reactive functional groups produced by, the addition of a catalyst. Although the modified acrylic resin can be " incorporated into the aforesaid dry polymer-modified cement, suitable acrylic resins are commercially available as aqueous latexes, and when so employed, the aqueous modified acrylic resin is preferably mixed with the polymer-modified cement just prior to using the leveling composition. In the event the acrylic resin contains an epoxide group or precursor, cross-linking can be effected with a basic catalyst, such as sodium bicarbonate, sodium hydroxide, magnesium oxide, or zinc oxide, for example. A preferred catalyst is sodium carbonate sesquihydrate. Between about 1 and about 5 percent of the latter, based upon the weight of the acrylic resin, is added at the time the components of the leveling composition are mixed. Alternatively, the catalyst may be present in the polymer-modified cement as a curing accelerator. At the time the dry polymer-modified cement, the modified acrylic resin latex, and any necessary catalyst are mixed, additional water may be added to provide the desired consistency for spreading the leveling composition over the old flooring. In general terms, the leveling composition will contain by weight about 2 to about 4 parts polymer-modified cement, about 1 part modified acrylic resin, about 1 to 3 parts water, and catalyst. Example 1 sets forth ingredients in a typical leveling composition of this invention. EXAMPLE 1 LEVELING COMPOSITION Component Quantity Polymer-Modified Cement a 2 Parts Modified Acrylic Resin b 1 Part Catalyst 0 Water 1 Part a Portland cement modified with 5% ethylene/vinyl acetate copolymer. Available commercially as "Ardex ' K-55" from Ardex, Inc., 630 Stoops Ferry Road, Caraopolis, PA 15108. b Latex containing approximately 60% solids. Available commercially as ROBOND LEC-58 from Rohm and Haas Company, Independence Mall West, Philadelphia, PA 19105. c Sodium carbonate sesquihydrate; 1% by weight, based on the modified acrylic resin latex. In addition to the leveling composition, this invention provides a method for renewing an old floor covering which utilizes the leveling composition. In order to renew such an old floor covering, the old floor covering should be firmly adhered to the floor. Then, if at some later date it is desired to again replace the floor covering, the topmost floor covering can be peeled from the floor, leaving the original, old floor covering behind, and another floor covering can be installed over a new application of the leveling composition. In the event the old floor covering cannot be thoroughly cleaned, it is desirable to begin the renewal by applying a primer to the exposed surface of the old floor covering. Although a number of primers are satisfactory, a latex which includes a polymeric component and one or more surfactants is desirable. The polymeric component can include acrylic, vinyl/acrylic, and styrene/acrylic resins, for example. When required, the primer is first applied to the old floor covering and dried. The next step in practicing the method is to select a leveling composition. This selection can be made from leveling compositions which are within the scope of this invention as described above. Alternatively, certain leveling compounds and compositions, e.g. , cementitiouε compositions disclosed in the prior art, can be satisfactory. Having selected a leveling composition, it is applied to produce a smooth-faced stratum over the old floor covering, and the leveling composition is then cured. If a leveling composition of this invention has been selected, curing is generally effected by allowing the leveling composition to harden at ambient temperature, drying to some extent, during which the modified acrylic resin begins to cross-link. Sufficient hardening and curing generally take place at ambient temperature in about 1 to about 2 hours, and higher temperatures promote faster curing. The new floor covering is then adhered to the exposed surface of the hardened leveling composition. The new floor covering can be laid down using one of the latex adhesiveε. commonly used in the flooring industry for such purposes. The practice of the method of this invention is illustrated in Example 2. EXAMPLE 2 METHOD OF RENEWING OLD FLOORING A^ A piece of embossed, cushioned vinyl floor covering is taped down to a 2 ft. X 2 ft. panel of 1/2 in. plywood with double-faced tape to hold it flat. The leveling composition of Ex. 1 is applied and smoothed with a trowel. Prior to drying, 1 in. wide cotton cloth strips are embedded in the wet leveling compound. The composite is allowed to dry approximately 90 minutes. Then 1 in. wide by 6 in. long strips of the composite, which consists of the resilient flooring, the leveling compound, and the cloth strips are cut and subjected to tensile testing. A duplicate piece of resilient flooring is similarly taped down to another 2 ft. X 2 ft. panel and the same leveling compound is applied in the identical manner. After approximately 90 minutes of curing time, a second piece of resilient flooring is adhered to the exposed face of the hardened leveling compound using techniques standard in the industry, including a multi-purpose latex adhesive made from a styrene-butadiene rubber (available from Congoleum Corporation, Trenton, New Jersey as No. 3033) . After approximately 72 hours, 1 in. X 6 in. strips of the composite are cut and similarly subjected to tensile testing. The composite strips are placed in a standard tensile testing machine and peeled apart at an angle of approximately 90°. The force required to peel the composites apart is recorded as is the failure mechanism. The results of such tests appear in Table 1. TABLE 1 PEEL ADHESION TESTS Sample 90" Peel Failure Cloth embedded in 1.2 - 3.5 pli* Within the leveling compound leveling compound New floor covering 0.3 - 0.5 pli* leveling compound over leveling compound to old flooring *pli — pounds per linear inch B. A 4 ft. X 4 ft. text floor panel is constructed from 2 in. X 4 in. studs and 1/2 in. thick plywood which is conditioned for six weeks at 85°F and 85% R.H. to swell them to a state simulating summer ambient structure conditions in a home. After the 4 ft. X 4 ft. deck is assembled, resilient flooring of various types is adhered to the plywood face. The leveling compound of Ex. 1 is applied to the resilient flooring and allowed to cure for 90 minutes. After the leveling compound has hardened, a new piece of resilient flooring is adhered to the exposed face of the leveling compound using various adhesives standard in the art. The composite is cured at ambient conditions for 72 hours and is then placed in a 110°F oven for six weeks to allow the deck to shrink to a state simulating winter ambient structure conditions in a home. The deck is removed after the six-week period and examined for buckles or loose spots as an indication of the shear resistance of the composite. The results of such tests appear in Table 2. TABLE 2 SHEAR ADHESION TESTS Sample Adhesive Type Failure Vinyl flooring over Multi-purpose None vinyl flooring Styrene-butadiene Rubber * Vinyl flooring over Multi-purpose None urethane coated flooring Styrene-butadiene Rubber * Vinyl flooring over Acrylic latex b None vinyl flooring a Latex available as No. 3033 from Congoleum Corporation, Trenton, NJ. b Available as No. 3010 from Congoleum Corporation, Trenton, NJ. Although the aforesaid detailed description of the invention is limited to preferred embodiments, it will be apparent that other embodiments will be readily accessible to those skilled in the art.

Claims: What is claimed is: 1. A method for renewing an old floor covering adhered to a floor which comprises (1) selecting a leveling composition; (2) applying said leveling composition to produce a smooth-faced stratum over the old floor covering; (3) curing said leveling composition, bonding said stratum to the old floor covering; and (4) adhering a new floor covering onto said cured leveling composition. 2. The method of claim 1 wherein said leveling composition comprises in combination a polymer-modified cement, a modified acrylic resin latex, catalyst, and water. 3. The method of claim 2 wherein said polymer-modified cement includes an ethylene/vinyl acetate copolymer. 4. The method of claim 3 wherein said copolymer comprises between about 2 and about 10 percent by weight of said polymer-modified cement. 5. The method of claim 2 wherein said polymer-modified cement includes an inorganic component selected from high hydrate Portland or gypsum cement. 6. The method of claim 2 wherein said modified acrylic resin latex contains an acrylic polymer in which reactive groups are generated in the presence of a catalyst. 7. The ' method of claim 6 wherein said reactive groups are epoxide groups. 8. The method of claim 6 wherein said reactive groups cross¬ link said acrylic polymer. 9. The method of claim 7 wherein said catalyst is a basic catalyst. 10. The method of claim 7 wherein said catalyst is sodium carbonate sesquihydrate. 11. The method of claim 10 wherein sodium carbonate sesquihydrate comprises between about 1 and about 5 percent by weight of said modified acrylic resin latex. 12. A method for renewing an old floor covering which comprises (1) selecting a leveling composition which includes in combination (a) a polymer-modified cement comprising an inorganic component selected from Portland or gypsum cement and between about 2 and about 10 percent by weight of ethylene/vinyl acetate copolymer, (b) a modified acrylic resin latex comprising an acrylic polymer in which epoxide groups are produced in the presence of between about 1 and about 5 percent by weight of a basic catalyst, and (c) water; (2) applying said leveling composition to produce a smooth-faced stratum over the old floor covering; (3) curing said leveling composition to bond said stratum to the old floor covering; and (4) adhering a new floor covering onto said cured leveling composition. 13. The method of claim 2 wherein said leveling composition includes by weight about 2 to about 4 parts polymer-modified cement, about 1 part modified acrylic resin latex, and about 1 to about 3 parts water. 14. The method of claim 1 which further comprises applying a latex primer to the old floor covering prior to applying said leveling composition. 15. The method of claim 14 wherein said primer comprises at least one resin selected from the group consisting of acrylic, vinyl/acrylic and styrene/acrylic resins, together with a surfactant. 16. The method of claim 12 wherein the old floor covering is an embossed floor covering. 17. A composite floor covering which comprises (1) an old floor covering firmly adhered to a floor, . (2) a new floor covering, and (3) a cured leveling composition sandwiched between said old and said new floor coverings. 18. The composite floor covering of claim 17 wherein said old floor covering is embossed. 19. The composite floor covering of claim 17 wherein said cured leveling composition is produced from a combination of a polymer-modified cement, a modified acrylic resin latex, catalyst, and water. 20. The composite floor covering of claim 19 wherein said polymer-modified cement includes an ethylene/vinyl acetate copolymer. 21. The composite floor covering of claim 20 wherein said copolymer comprises between about 2 and about 10 percent by weight of said polymer-modified cement. 22. The composite floor covering of claim 19 wherein said polymer-modified cement includes an inorganic component selected from high hydrate Portland or gypsum cement. 23. The composite floor covering of claim 19 wherein said modified acrylic resin latex contains an acrylic polymer in which reactive groups are generated in the presence of a catalyst. 24. The composite floor covering of claim 23 wherein said reactive groups are epoxide groups. 25. The composite floor covering of claim 23 wherein said reactive groups cross-link said acrylic polymer. 26. The composite floor covering of claim 24 wherein said . catalyst is a basic catalyst. 27. The composite floor covering of claim 24 wherein said catalyst is sodium carbonate sesquihydrate. 28. The composite floor covering of claim 17 which further comprises a primer stratum between said old floor covering and said cured leveling composition. 29. The composite floor covering of claim 17 wherein the peel adhesion between the old floor covering and said cured leveling composition is between about 0.1 and about 1 lb./in., and the cohesive strength of said cured leveling composition is greater than about 1 lb./in. 30. A leveling composition for renewing an old floor covering which comprises in combination a polymer-modified cement, a modified acrylic resin latex, catalyst, and water. 31. The leveling composition of claim 30 wherein said polymer-modified cement includes an ethylene/vinyl acetate copolymer. 32. The leveling composition of claim 31 wherein said copolymer comprises between about 2 and about 10 percent by weight of said polymer-modified cement. 33. The leveling composition of claim 30 wherein said polymer-modified cement includes an inorganic component selected from high hydrate Portland or gypsum cement. 34. The leveling composition of claim 30 wherein said modified acrylic resin latex contains an acrylic polymer in which reactive groups are generated in the presence of a catalyst. 35. The leveling composition of claim 34 wherein said reactive groups are epoxide groups. 36. The leveling composition of claim 34 wherein said reactive groups cross-link said acrylic polymer. 37. The leveling composition of claim 35 wherein said catalyst is a basic catalyst. 38. The leveling composition of claim 35 wherein said catalyst is sodium carbonate sesquihydrate. 39. The leveling composition of claim 38 wherein sodium carbonate sesquihydrate comprises between about 1 and about 5 percent by weight of said modified acrylic resin latex. 40. The leveling composition of claim 30 which includes by weight about 2 to about 4 parts polymer-modified cement, about 1 part modified acrylic resin latex, and about 1 to about 3 parts water.

Inventors: SAPIENZA MICHAEL A, SAPIENZA, MICHAEL, A.
Applicants: CONGOLEUM CORP, SAPIENZA MICHAEL A, CONGOLEUM CORPORATION, SAPIENZA, MICHAEL, A.
Application year: 1989
Main classification: C04B26
IPC codes: C04B28, E04F15