Modified cement tile adhesive and grout

Abstract

Methods of formulating, premixed cement-based tiling compositions and application of such premixed cement-based tiling compositions as an adhesive or grout. The premixed cement-based tiling compositions include a premixed cementitious formulation having a pH and an alkali activation constituent. The premixed cementitious formulation includes an aluminous or a calcium aluminate cement slurry in an amount of about 35 wt. % to 50 wt. % in combination with one or more filler or modifier materials present in an amount of about 40 wt. % to 65 wt. %. The alkali activation constituent destabilizes the premixed cementitious formulation by increasing the pH thereof to generate a reaction between the premixed cementitious formulation and the alkali activation constituent resulting in the cement-based tiling composition for use as an adhesive or a grout. The alkali composition may be sodium hydroxide supersaturated with lithium carbonate.

Claims

1. A cement-based tiling composition for use as an adhesive or grout comprising: a premixed cementitious formulation having a pH, the premixed cementitious formulation including a cement slurry in an amount of about 35 wt. % to less than 50 wt. % in combination with at least one filler material present in an amount of about 40 wt. % to about 65 wt. % based on a total weight of the formulation, the cement slurry comprising an aluminous cement slurry or a calcium aluminate cement slurry; and an activation constituent that destabilizes the premixed cementitious formulation by increasing the pH thereof to generate a reaction between the premixed cementitious formulation and the activation constituent resulting in the cement-based tiling composition for use as an adhesive or a grout.

2. The cement-based tiling composition of claim 1 wherein the premixed cementitious slurry has a neutral pH.

3. The cement-based tiling composition of claim 2 wherein the premixed cementitious slurry is increased to a pH at or above 11.

4. The cement-based tiling composition of claim 1 wherein the activation constituent is an alkali activation constituent.

5. The cement-based tiling composition of claim 4 wherein the alkali constituent comprises a solution of sodium hydroxide saturated with lithium carbonate.

6. The cement-based tiling composition of claim 5 wherein the sodium hydroxide is present in the solution from about 3-15% and the lithium carbonate is present in the solution from about 2-8%.

7. The cement-based tiling composition of claim 1 wherein the premixed cementitious formulation further includes one or more of the following additives selected from the group consisting of thickeners, defoamers, surfactants, modifiers, biocide, preservatives, and plasticizers.

8. The cement-based tiling composition of claim 1 wherein the at least one filler material is silica sand present in an amount of about 40 wt. % to about 60 wt. %.

9. A cement-based tiling composition for use as an adhesive or grout consisting essentially of: a premixed cementitious formulation having a pH, the premixed cementitious formulation including a cement slurry in an amount of about 35 wt. % to less than 50 wt. % in combination with at least one filler material present in an amount of about 40 wt. % to about 65 wt. % based on a total weight of the formulation, the cement slurry comprising an aluminous cement slurry; and an alkali activation constituent that destabilizes the premixed cementitious formulation by increasing the pH thereof to generate a reaction between the premixed cementitious formulation and the alkali activation constituent resulting in the cement-based tiling composition for use as an adhesive or a grout.

10. The cement-based tiling composition of claim 9 wherein the alkali activation constituent comprises a solution of sodium hydroxide saturated with lithium carbonate.

11. The cement-based tiling composition of claim 10 wherein the sodium hydroxide is present in the solution from about 3-15% and the lithium carbonate is present in the solution from about 2-8%.

12. The cement-based tiling composition of claim 9 wherein the premixed cementitious formulation further includes one or more of the following additives selected from the group consisting of thickeners, defoamers, surfactants, modifiers, biocide, preservatives, and plasticizers.

13. A cement-based tiling composition comprising: a premixed cementitious formulation comprising; a first filler in an amount of about 40 to 60 wt. %, a cement slurry in an amount of about 35 to less than 50 wt. %, the cement slurry comprising an aluminous cement slurry or a calcium aluminate cement slurry, cellulose ether in an amount of about 0 to 0.45 wt. %, defoamer in an amount of about 0 to 0.1 wt. %, polymer fibers in an amount of about 0 to 2 wt. %, a second filler being a recycled light weight filler in an amount of about 0 to 15 wt. %, biocide in an amount of about 0 to 0.02 wt. %, clays and/or thickeners in an amount of about 0 to 1 wt. %, redispersible polymer powder in an amount of about 0 to 10 wt. %, superplasticizers in an amount of about 0 to 2 wt. %, and an activator solution that destabilizes the premixed cementitious formulation by increasing the pH thereof to provide the cement-based tiling composition, the cement-based tiling composition suitable for use as an adhesive or a grout for tiling.

14. The cement-based tiling composition of claim 13 wherein the cement slurry includes calcium aluminate cement present in an amount of about 35 to 49 wt. % based on said total weight of the slurry.

15. The cement-based tiling composition of claim 13 wherein the cement slurry includes aluminous cement present in an amount of about 35 to less than 50 wt. % based on said total weight of the slurry.

16. The cement-based tiling composition of claim 13 wherein the activator solution is an alkali activator solution comprising a solution of sodium hydroxide saturated with lithium carbonate, the sodium hydroxide is present in the solution from about 3-15% and the lithium carbonate is present in the solution from about 2-8%.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The features of the invention believed to be novel and the elements characteristic of the invention are set forth with particularity in the appended claims. The figures are for illustration purposes only and are not drawn to scale. The invention itself, however, both as to organization and method of operation, may best be understood by reference to the detailed description which follows taken in conjunction with the accompanying drawings in which:

(2) FIGS. 1A-B are tables showing exemplary premixed calcium aluminate cement formulations suitable for use in the cement-based adhesive and/or grout compositions in accordance with one or more embodiments of the invention.

(3) FIG. 2 is a plot showing correlation between an activator composition, addition levels and the raise in pH.

(4) FIG. 3 is a plot comparison of vitreous tile shear strength (psi) as a function of concentration of the activator solution.

DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

(5) In describing the preferred embodiment of the present invention, reference will be made herein to FIGS. 1-3 of the drawings in which like numerals refer to like features of the invention.

(6) The embodiments of the present invention can comprise, consist of, and consist essentially of the features and/or steps described herein, as well as any of the additional or optional ingredients, components, steps, or limitations described herein or would otherwise be appreciated by one of skill in the art. It is to be understood that all concentrations disclosed herein are by weight percent (wt. %.) based on a total weight of the composition unless otherwise indicated.

(7) The present invention refers to the use of a unique, ready to use formulation, suitable for use as an adhesive (e.g., a Ceramic Tile Adhesive CTA) or as a tile grout, filling spaces between ceramic tiles or mosaics after installation. The various embodiments of the invention relate to application of a stabilized cement formulation as a grout or CTA. The compositions utilize a formulated two part system. In one or more embodiments the invention is directed to activation of the present formulated cements to perform as a CTA/grout that meets appropriate ANSI standards for a grout (ANSI A118.7) or a CTA ANSI A118.15.

(8) In accordance with the invention, one or more embodiments are directed to cement-based tiling compositions formulated for use as grouts and adhesives. As used herein the term tiling compositions refers to the present cement-based compositions suitable for use as an adhesive to adhere tile to a substrate, or as a grout to fill spaces between tiles or mosaics after installation. These cementitious compositions include formulating a stabilized aluminous or calcium aluminate based cement slurry into a premixed adhesive (e.g., CTA) or a grout. Advantageously, these adhesive and grout compositions are ready to use formulations. To obtain the necessary performance attributes, the premixed adhesive and/or grout formulations need to be activated on site just before application thereof. Upon activation, it has been found that the adhesive and/or grout behave like conventional aluminous or calcium aluminate cement based formulas with respect to application, workability, strength development and time to traffic.

(9) The various premixed cement-based compositions of the invention are two-component part formulations that include both a premixed aluminous or calcium aluminate cement formulation and an activator solution. The premixed aluminous or calcium aluminate cement formulation and activator solution are mixed together, just prior to use thereof, to render the various cement-based compositions of the invention formulated as adhesives and/or grouts.

(10) The first component of the present two-part formulations is the premixed aluminous or calcium aluminate cement formulation. This premixed cement formulation may include an aluminous or calcium aluminate cement slurry, fillers, thickeners and other modifiers such as defoamers, surfactants and the like. In one or more embodiments other adhesive and/or grouting constituents or compositions may also be included within the present compositions to provide desired adhesive and/or grouting properties. These various premixed aluminous or calcium aluminate formulations may be provided as thick materials or solutions that are shelf stable and do not lose rheological behavior when stored in a container over long periods of time.

(11) In accordance with the various embodiments, the premixed cement formulations/compositions may include an aluminous or calcium aluminate cement slurry. In one or more preferred embodiments the premixed cement formulation is a premixed calcium aluminate cement slurry. The aluminous or calcium aluminate cement slurry may be present in an amount of about 35 wt. % to about 50 wt. %, based on a total weight of the premixed cement composition. An exemplary aluminous and/or calcium aluminate cement slurry suitable for use in the present formulations may be that of the stabilized aluminous or calcium aluminate cement slurry as described in the patent publication number WO 2013093344 A1 by Pascal Taquet et al., which is herein incorporated by reference in its entirety.

(12) The premixed cement formulations also include filler materials. The filler materials may be present in an amount of about 40 wt. % to about 65 wt. %, based on a total weight of the premixed cement composition. These filler materials may include silica sand filler present in an amount of about 40 wt. % to about 60 wt. %, as well as a light weight filler present in an amount of about 0 wt. % to about 15 wt. %. Exemplary silica sand fillers include, but are not limited to, fine silica, limestone (calcium carbonate), various minerals, reflective particles, glass, colored beads, dyes, pigments, and combinations thereof. The light weight filler may be, for instance, recycled light weight glass filler.

(13) The thickeners of the premixed cement formulations/compositions may include clays and/or other thickeners to provide the resultant slurry with the desired viscosity and/or density. These clays and/or thickeners may be present in an amount of about 0 wt. % to about 1.45 wt. %, based on a total weight of the premixed cement composition. Exemplary clays and thickeners may include, but are not limited to, cellulose ether, water soluble polymer, starch ethers, hydroxymethyl cellulose, hydroxyethyl cellulose, fibers, fumed silica, associative and alkali swellable thickeners, and combinations thereof.

(14) The premixed cement composition may also include various other modifiers in amounts ranging from about 0 wt. % to about 20 wt. %, based on a total weight of the premixed cement composition. These modifiers may include, for example, defoamers present in an amount of about 0 wt. % to about 0.2 wt. %. Exemplary defoamers may include, but are not limited to, polyether chemistries, fatty acids, modified siloxanes, and combinations thereof. Modifiers may also include surfactants to decrease water surface tension, reduce viscosity, eliminate entrained air, and even stabilize the premixed cement formulations. In one or more embodiments the surfactants may include superplasticizers present in amounts ranging from about 0 wt. % to about 2 wt. %. Exemplary superplasticizers include, but are not limited to, polycarboxylate based water reducers, and the like.

(15) The various embodiments of the present premixed cement compositions may also have other modifiers including, but not limited to, biocides, in-can preservatives, fibers/rheological modifiers, redispersible polymer powder, and combinations thereof. Biocides may be present in the premixed cement compositions in amounts of about 0 wt. % to about 0.02 wt. %. Biocides may include, but are not limited to, conventional powder and liquid based biocides, or combinations thereof. The in-can preservatives may also include conventional organic and/or inorganic preservatives in amounts of about 0.001 wt. % to about 0.002 wt. %.

(16) The fibers and/or rheological modifiers may be included in the present premixed cement compositions in amounts of about 0 wt. % to about 0.2 wt. %. Exemplary fibers and/or rheological modifiers may include, but are not limited to, polymer fibers of different lengths, glass fibers of different lengths, and combinations thereof. The redispersible polymer powder may be present in the compositions in amounts of about 0 wt. % to about 10 wt. % to provide the compositions with increased flexibility, water resistance and compatibility with various hydraulic systems. Exemplary redispersible polymer powders may include, but are not limited to, styrene acrylic based polymer powders, styrene butadiene based polymer powders, and combinations thereof.

(17) In certain embodiments of the invention, other modifiers may include inorganic pigments, inorganic fillers, water repellants, and combinations thereof. The inorganic pigments may be present in amounts of about 0 wt. % to about 4 wt. %. Exemplary inorganic pigments may include, but are not limited to, iron oxides, titanium dioxides, chrome oxides, and combinations thereof. Inorganic fillers may be present in amounts of about 0 wt. % to about 10 wt. %, with such exemplary fillers including limestone and/or dolomitic Limestone. The premixed cement formulations may also include water repellants, such as, lignosulphonates and/or polycarboxylates. The water repellants may be present in amounts of about 0 wt. % to about 2 wt. %.

(18) Referring to FIGS. 1A-B, exemplary premixed cement formulations are shown that are suitable for use as cement-based adhesive and grout compositions in accordance with the invention. Preferably, the premixed cement formulations are premixed calcium aluminate cement formulations.

(19) FIG. 1A shows a premixed cement formulation for a Ceramic Tile Adhesive CTA of the invention. In this embodiment, the first component premixed CTA cement formulation may include at least about 40 to 60 wt. % silica sand filler in combination with about 35 to 50 wt. % calcium aluminate slurry. The CTA cement formulation may also include one or more of the following: 0 to 0.45 wt. % cellulose ether; 0 to 0.1 wt. % defoamer; 0 to 2 wt. % fibers/rheological modifiers; 0 to 15 wt. % recycled light weight filler; 0 to 0.02 wt. % biocide; 0.001 to 0.002 wt. % in-can preservative; 0 to 1 wt. % clays and/or thickeners; 0 to 10 wt. % redispersible polymer powder; 0 to 2 wt. % superplasticizers, and any combination thereof. Again, it should be appreciated and understood that these CTA embodiments can comprise, consist of, and/or consist essentially of any of the foregoing ingredients/constituents.

(20) The present premixed cement formulations may also be formulated as a premixed grout cement formulation. The table of FIG. 1B shows a premixed cement grout formulation of the invention. In this embodiment, the first component premixed cement grout formulation may include at least about 40 to 55 wt. % silica sand filler in combination with about 35 to 50 wt. % calcium aluminate slurry. The CTA cement formulation may also include one or more of the following: 0 to 0.45 wt. % cellulose ether; 0.01 to 0.2 wt. % defoamer; 0 to 2 wt. % fibers/rheological modifiers; 0 to 15 wt. % recycled light weight filler; 0 to 0.02 wt. % biocide; 0.001 to 0.002 wt. % in-can preservative; 0 to 1 wt. % clays and/or thickeners; 0 to 3 wt. % redispersible polymer powder; 0 to 2 wt. % superplasticizers, 0 to 4 wt. % inorganic pigments; 0 to 10 wt. % inorganic fillers (limestone); 0 to 2 wt. % water repellant; and any combination thereof. It should also be appreciated and understood that these premixed cement grout formulation embodiments can comprise, consist of, and/or consist essentially of any of the foregoing ingredients/constituents.

(21) In accordance with the invention, the above first component (of the two-component part formulations) comprises a stabilized premixed cement slurry formulation having fillers and/or modifiers. These premixed cement slurry formulations are neutral slurries having a pH of about pH7, and are stable in slurry when fully formulated. The premixed cement slurries preferably have high freeze/thaw temperatures while maintaining a stable compound, which are formulated without other pozzolans (i.e., siliceous or siliceous and aluminous material, or materials capable of reacting with calcium hydroxide and water (e.g., volcanic tuff or ash used in making hydraulic cement)).

(22) The various premixed cement slurry formulations, preferably premixed calcium aluminate cement slurries, are mixed with the second component part of the instant two-component part formulations. The second component part is an activation formulation rendered as an activator solution. The activator solution destabilizes the premixed cement slurry formulations to initiate the hydration process for the premixed cement slurries of the various CTA and/or grouts of the invention. The various embodiments of the invention use different combinations of alkalis to bring the premixed cement slurry formulations to a higher pH, thereby initiating reaction between these two-component parts of the instant compositions.

(23) In accordance with one or more embodiments of the invention the activator solution may include, but is not limited to, one or more sodium hydroxide solutions at different concentrations, each saturated with different amounts of lithium carbonate at different concentrations within the solution as an activator. For instance, the activator solution may include sodium hydroxide solutions having sodium hydroxide concentrations of 3%, 5%, 7%, 14%, 21% or 28%, while such solutions are supersaturated with 2%, 4%, 6% and/or 8% of lithium carbonate as the activator. To activate the premixed cement slurry, the pH of the activator solution is preferably at or above 11.

(24) FIG. 2 shows plotted correlations between the above activator composition concentrations, addition levels and the raise in pH of CTA and/or grout formulation slurries of various embodiments of the invention. As is shown, solutions of sodium hydroxide are saturated with different concentrations of lithium carbonate activator. At each of the composition and addition levels the pH were recorded, and properties of applied various CTA and/or grouts of the invention measured. For instance, Plot 2 of FIG. 3 shows a comparison of vitreous tile shear strength (psi) as a function of concentration of the activator solution.

(25) It has unexpectedly been found that the various CTA and/or grouts of the invention provide a continuous surface that is easy to keep clean. In the different embodiments of the present CTA and/or grouts, once applied to a substrate the dried products of the invention exhibit enhanced hardness, abrasion resistance and stain resistance over conventional premixed CTAs and grouts. Also, the instant CTA and/or grouts develop hardness of the final dried products at a fast rate as compared to conventional products. In the CTA embodiments of the invention the instant CTAs may be used as an adhesive to bond tiles to wood, concrete or any kind of flooring material. Key performance requirements of the CTAs of the invention are workability, open time and strength development.

(26) While the present invention has been particularly described, in conjunction with a specific preferred embodiment, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. It is therefore contemplated that the appended claims will embrace any such alternatives, modifications and variations as falling within the true scope and spirit of the present invention.