Peelable protective composite

Abstract

An adhesive, peelable, sheet-form composite for flooring has a warp knit embedded in a polymerized polyvinyl butyral resin film having a tensile strength of at least megapascals, an elongation of more than 1,000 percent, and an adhesive strength of no more than about one megapascal. The adhesive, peelable, sheet-form composite has a maximum peel adhesion to a finished concrete surface of at least 60 ounces / inch but no more than 100 ounces / inch.

Description

[0001] PEELABLE PROTECTIVE COMPOSITE

[0002] Field of Invention

[0003] This invention relates to peelable protective covers for flooring, and the like.

[0004] Background of Invention

[0005] A need exists to protect non-porous surfaces, such as concrete flooring, from damage caused by weathering, abrasion, staining, scratching, and the like by a temporary, peelable cover which can be subsequently easily removed from a non- porous concrete surface without damaging the surface. The present peelable protective composite satisfies that need.

[0006] Summary of Invention

[0007] An adhesive, peelable, sheet-form composite is provided over a concrete flooring surface, and the like, in need of temporary protection during construction, due to moving of heavy equipment, and similar operations. The adhesive, sheetform composite has a relatively high tensile strength, resists abrasion, and comprises a warp knit fabric embedded in a polymerized resin film. The present sheet-form composite is also useful for enhanced curing of freshly poured concrete.

[0008] The peelable, sheet-form composite is formed by first placing a liquid permeable, warp knit fabric web, preferably a warp knit polyester web, contiguous with the flooring surface, such as a concrete slab, thereafter applying to the warp knit fabric web a water-based, film forming liquid containing dispersed, polymerizable solids, preferably a polyvinyl butyral resin composition, in an amount sufficient to pass through the web, wet the flooring surface, surround the web, and form a liquid layer, preferably having a thickness of at least 250 microns. Thereafter, the liquid layer is solidified by drying so as to polymerize dispersed solids and to produce a removable composite comprising the warp knit fabric embedded in a polymerized resin film. The film preferably has a thickness of at least about 100 microns, a tensile strength of at least 5 megapascals (MPa), an elongation of more than 1,000 percent, and an adhesive strength of no more than about one megapascal (MPa). The adhesive, peelable, sheet-form composite has a peel adhesion to a finished concrete surface of at least 60 ounces / inch but no more than 100 ounces / inch as determined by ASTM D3330-04 (2018), Method F.

[0009] The preferred water-based, film forming liquid is a water dispersion of polymerizable polyvinyl butyral resins having a solids content of at least 30 percent by weight, preferably in the range of about 30 to about 60 percent by weight.

[0010] Brief Description of Drawings

[0011] In the drawings,

[0012] FIGURE 1 is a plan view of a portion of the protective composite applied to a concrete flooring; and

[0013] FIGURE 2 is an enlarged sectional view taken along plane 2-2 shown in FIGURE 1.

[0014] Description of Preferred Embodiments

[0015] Referring to the drawings, FIGURE 1 shows a peelable protective composite 10 which is a warp knit fabric web 12 embedded in a polymerized polyvinyl butyral resin film 14. The composite is releasable from a solid, non- porous surface such as concrete 16, as shown in FIGURE 2.

[0016] The warp knit fabric web suitable for practicing the present invention is permeable to a water-based, film-forming liquid that forms a peelable film by direct emulsion polymerization and has a weight in the range of about 4.5 ounces / square yard to about 6.5 ounces / square yard. Preferably the warp knit fabric has a weight of about 5.25 ounces / square yard to about 5.45 ounces / square yard, and more preferably about 5.35 ounces / square yard. Illustrative warp knit fabrics are polyester warp knit fabrics, and the like. Preferred polyester warp knit fabrics are commercially available from Apex Mills, 2350 Long Dairy Rd, Graham, North Carolina 27253. The water-based, film-forming liquid suitable for practicing the present invention is a polymerizable resin, preferably a polyvinyl butyral resin, dispersion in water.

[0017] Viscosity of the water-based polymerizable resin dispersions is in the range of about 16,000 to about 20,000 centipoise (cP) at 20 degrees C. The water based polymerizable resin dispersions have a solids content of at least about 30 percent by weight, preferably in the range of about 30 percent to about 60 percent by weight, more preferably about 40 percent to about 55 percent by weight.

[0018] A peelable, protective composite embodying the present invention is formed on a flooring surface by first placing the warp knit fabric on the surface to be protected and contiguous therewith. The water-based, film-forming liquid thereafter is applied to the web by pouring and spreading in any convenient manner in an amount sufficient to wet the flooring surface, surround the web, and form a wet liquid layer that encompasses the warp knit fabric and forms a liquid layer, preferably having a thickness of at least 250 microns, more preferably about 250 to about 500 microns, which is then solidified by air drying to induce direct emulsion polymerization and to form a film which surrounds the warp knit web and releasably adheres to the flooring surface.

[0019] The peelable, protective composite has a peel adhesion to a finished concrete floor of at least 60 ounces / inch but no more than 100 ounces / inch according to ASTM D3330-04 (2018), Method F, preferably in the range of about 70 ounces / inch to about 80 ounces / inch. Peel adhesion greater than 100 ounces / inch tends to leave undesirable residue on the flooring surface upon removal.

[0020] The protective covering produced in the aforedescribed manner has the warp knit fabric embedded in a film having thickness of at least 100 microns, a tensile strength of at least five megapascals (MPa), an elongation of more than 1,000 percent, and an adhesive strength of no more than about one megapascal (MPa). Example

[0021] An adhesive, peelable, protective, sheet-form composite is formed on a concrete floor by first placing on the concrete floor a warp knit weave fabric having a weight of 5.35 ounces / square yard. A film forming dispersion of a polyvinyl butyral resin in water (about 45 weight percent of solids; pH 7-8; viscosity 18,000 ± 2,000 cP @ 20°C.) is then spread over the warp knit fabric to form a liquid layer about 250 microns thick.

[0022] The formed liquid layer together with the warp knit fabric is then exposed to ambient air and dried to induce polymerization of the resin and to produce a dry film about 100 microns thick and having the warp knit fabric embedded therein.

[0023] The dry, peelable, protective composite obtained in the foregoing manner is manually peeled from the concrete floor. Surface of the composite that was in contact with the concrete floor is defined primarily by the dry film. The peel adhesion is about 73 ounces / inch, according to ASTM D3330-04 (2018), Method F.

[0024] The peelable protective composite embodying the invention can also be utilized to enhance and promote curing of freshly poured concrete.

[0025] It is well known that during an initial time period after concrete is poured it is necessary to maintain proper temperature and dampness to insure proper curing of the concrete. An uncured, or improperly cured slab of concrete is likely to develop crazing (fine cracks) and the slab surface is likely to have low strength and low resistance to abrasion. It has been found that such problems can be ameliorated by the application of the peelable protective composite after a freshly poured concrete has been sufficiently set for surface grinding and polishing, usually about ten days after pouring.

[0026] In a typical application the following events take place:

[0027] Day 1 - concrete slab is poured

[0028] Days 2 to 10 - poured concrete is permitted to cure in a conventional manner, e.g., by wet cure, blanket cure, chemical cure, and the like

[0029] Day 10 - the poured concrete is sufficiently solidified, and is subjected to surface grinding and polishing

[0030] Day 10+ - the present peelable composition is applied to the polished concrete surface and is kept in place for at least ten days, preferably for 15 to 18 days

[0031] The description above and the drawings are illustrative of the present invention and are not to be construed as limiting. Still other variants within the spirit and scope of the claimed invention are possible and will readily present themselves to those skilled in the art.

Claims

CLAIM:

1. An adhesive, peelable, sheet-form composite suitable for temporary protection of a finished concrete surface and comprising a warp knit fabric embedded in a film of polymerized polyvinyl butyral resin, said composite having a peel adhesion to a finished concrete floor of at least 60 ounces / inch but no more than 100 ounces / inch according to ASTM D3330-04 (2018), Method F; and said warp knit fabric having a weight in the range of about 4.5 ounces / square yard to about 6.5 ounces / square yard.

2. The adhesive, peelable, sheet-form composite in accordance with claim 1 wherein the peel adhesion is in the range of about 70 ounces / inch to about 80 ounces / inch.

3. The adhesive, peelable, sheet-form composite in accordance with claim 1 wherein the film of polymerized butyral resin has thickness of at least 100 microns, a tensile strength of at least 5 megapascals, an elongation of more than 1,000 percent, and an adhesive strength of no more than about 1 megapascal.

4. The adhesive, peelable, sheet-form composite in accordance with claim 1 wherein the warp knit fabric has a weight in the range of about 5.25 ounces per square yard to about 5.45 ounces per square yard.

5. The adhesive, peelable, sheet-form composite in accordance with claim 1 wherein the warp knit fabric has a weight in the range of about 5.35 ounces per square yard.

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