Redispersible dry powder

Abstract

The present disclosure provides for a redispersible dry powder formed from a latex polymer, a filler and lignin. For the various embodiments, the redispersible dry powder can also include a sulfosuccinate surfactant. The redispersible dry powder can also be included with a hydraulic binder to provide a dry hydraulic setting mixture.

Description

[0001] REDISPERSIBLE DRY POWDER

[0002] Technical Field

[0003] The present disclosure relates generally to redispersible dry powders and more particularly to redispersible dry powders that include organic fillers.

[0004] Background

[0005] Hydraulic setting mixtures, like concrete and mortar, are important building products in the construction industry. However, their production generates carbon dioxide waste. To address this issue, research has explored incorporating organic materials such biochar, agricultural waste, and / or recycled organic matter into these mixtures. The goal is to reduce or offset the carbon footprint while maintaining the quality and performance of the final product. One challenge, however, is ensuring that these organic materials do not compromise the quality or performance of the resulting hydraulic setting mixture. Additionally, the cost-effectiveness of using organic materials can vary depending on specific applications.

[0006] Therefore, there is a continuing need in the art to reduce waste and carbon dioxide emissions in producing hydraulic setting mixtures while maintaining cost-effectiveness and ensuring the quality of the mixtures for the construction industry.

[0007] Summary

[0008] The aforementioned needs may be met by various aspects of the present disclosure. Embodiments of the present disclosure provide for a redispersible dry powder for use in the construction industry, and more specifically in the hydraulic setting mixtures area. When used with hydraulic setting mixtures, the redispersible dry powder of the present disclosure can help to sequester carbon dioxide while still providing cost-effectiveness and ensuring the quality of the hydraulic setting mixture.

[0009] Specifically, the present disclosure provides for a redispersible dry powder (RDP) comprising components that include (a) 40 to 80 weight percent (wt.%) of a latex polymer; (b) 10 to 30 wt.% of a filler; and (c) 5 to 50 wt.% lignin, where the wt.% are based on the total weight of the redispersible dry powder and a sum of the components totals 100 wt.%. For the various embodiments, lignin can be selected from the group consisting of a Kraft lignin, soda lignin, organosolv lignin, hydrolytic lignin and combinations thereof. For the various embodiments, the lignin can have a weight average molecular weight of 10,000 to 100,000 Daltons. For the various embodiments, the components of the RDP can include (c) 10 to 25 wt.% lignin. In addition, for the various embodiments the components of the RDP can include (c) 10 to 50 wt.% lignin. In alternative embodiments, the components of the RDP can include (c) 15 to 20 wt.% lignin.

[0010] For the various embodiments, the components of the RDP can further include (d) 0.01 to 0.5 wt.% of a sulfosuccinate surfactant, where the wt.% of the components are based on the total weight of the RDP and a sum of the components totals 100 wt.%. In additional embodiments, the components of the RDP can include (d) 0.05 to 0.2 wt.% of the sulfosuccinate surfactant, where the wt.% of the components are based on the total weight of the RDP and a sum of the components totals 100 wt.%. For the various embodiments, the (d) sulfo succinate surfactant is of Formula I:

[0011] MSO3— R1— (— COOR2)n(Formula I) where M represents a hydrogen, metal or ammonium cation; R ' represents a linear or branched, saturated or unsaturated Cl- 10 alkylene moiety that is optionally substituted with one or more hydroxyl, halogen, nitro and / or cyano groups; each R2independently represents a linear or branched, saturated or unsaturated Cl -22 alkyl radical or a hydrogen, metal or ammonium cation; and n represents an integer from 1 to 10. More specifically, the sulfo succinate surfactant according to Formula I can be selected from the group consisting of a dioctyl sulfo succinate salt, a dihexyl sulfo succinate salt and combinations thereof.

[0012] For the various embodiments, (b) the filler can be selected from the group consisting of silica sand, dolomite, limestone, perlite, expanded polystyrene, hollow glass spheres, rubber crumbs, fly ash and combinations thereof. For the various embodiments, (a) the latex polymer can be formed from a latex dispersion comprising vinyl acetate-based polymer particles. For the various embodiments, the vinyl acetate-based polymer particles are formed of a copolymer formed with 50 to 95 weight percent (wt.%) vinyl acetate and 50 to 5 wt.% of a comonomer selected from the group consisting of styrene, butadiene, vinyl versatate, propionate, laurate, vinyl chloride, vinylidene chloride, ethylene, acrylates and combinations thereof, where the wt.% is based on the total weight of the copolymer. In more specific embodiments, the vinyl acetate- based polymer particles are formed from at least one of a vinyl acetate-ethylene copolymer and a vinyl acetate / vinyl-versatate copolymer.

[0013] The present disclosure also provides for a dry hydraulic setting mixture that includes a hydraulic binder and 0.2 to 10 wt.% of the RDP as provided above, where the wt.% are based on a total dry weight of the hydraulic binder and the RDP. For the various embodiments, the hydraulic binder can be selected from the group consisting of a Portland cement-based binder, lime aluminous cement and combinations thereof.

[0014] Detailed Description

[0015] Redispersible polymers (RPs) are a type of polymer that can be dried and then redispersed in water without losing their original properties. This unique characteristic makes RPs valuable in various applications, particularly in the construction industry. In the construction industry, RPs help to enhance the properties of construction materials like tile adhesives, mortars, and other hydraulic setting mixtures by forming a continuous polymer film in the system. The formation of a continuous polymer film inside the hydraulic setting mixture has a strong influence on its physical properties, such as durability, water resistance, rheology and its adhesion between the cementitious matrix and the substrates, as well as the reduction of the water demand. On the other hand, the use of RPs can significantly contribute to the carbon footprint of the hydraulic setting mixture.

[0016] Embodiments of the present disclosure address the above identified issues by combining a latex polymer, a filler, and lignin to provide a redispersible dry powder (RDP) that provides acceptable adhesive, flexural and / or compressive strength to hydraulic setting mixtures all while helping to reduce the carbon footprint of the RDP of the present disclosure.

[0017] As is known, lignin is a complex organic polymer found in the cell walls of all types of plants, and is obtained as a by-product in the pulp and paper industry in different forms, depending on the process of production / extraction. While it is abundant, the use of lignin with RPs and hydraulic setting mixtures is challenging due at least in part to its heterogeneous structure, incompatibility with many adhesives and low reactivity, which makes it difficult to predict and / or control its impact on the resulting hydraulic setting mixtures.

[0018] In contrast to these general understandings, the use of lignin in the RDP of the present disclosure for use in hydraulic setting mixtures is surprisingly effective, resulting in little to no loss in the required strength and resistance properties of the examples provided herein without changing the products’ initial characteristics and current properties. In addition, lignin has a low biogenic process carbon footprint, which can contribute significantly to the reduction of carbon emissions from the RDP of the present disclosure.

[0019] Throughout the specification, any reference to “percent” or “percent weight” is expressed in terms of dry weight of the composition, formulation or mixture unless otherwise specified.

[0020] As used herein, the term “hydraulic setting mixture” means a composition used in the construction field that can comprise a hydraulic binder, filler(s), water retention agent(s), and, further optionally, polymer containing additives such as a polymer dispersion and / or a redispersible polymer powder, such as the RDP of the present disclosure.

[0021] As used herein, the term “water soluble” refers to any compound that is soluble in water at 20 °C (e.g., forms a homogeneous solution).

[0022] As used herein, the term “hydraulic binder” refers to a mineral composition, normally of finely ground materials, which upon addition of an appropriate quantity of water forms a binding paste or slurry capable of hardening of hydration in air as well as under water and binds together the granulates.

[0023] As used herein “RDP” stands for the redispersible dry powder of the present disclosure.

[0024] Embodiments of the present disclosure provide for a RDP for use in the construction industry, and more specifically in the hydraulic setting mixtures area. When used with hydraulic setting mixtures, the RDP of the present disclosure can help to sequester carbon dioxide while still providing cost-effectiveness and ensuring the quality of the hydraulic setting mixture.

[0025] Specifically, embodiments of the present disclosure provide for a redispersible dry powder (RDP) that includes particles of a latex polymer, a filler and lignin. The RDP of the present disclosure helps to provide for a reduction in the carbon footprint associated with construction products as discussed herein. Specifically, the present disclosure replaces a portion of a carbon dioxide intensive component of the RPs, as discussed herein, with lignin with little to no impact on the strength and efficacy of the resulting hydraulic setting mixture. In other words, the present disclosure advantageously uses lignin to increase the bio-based content in the RDP of the present disclosure without, surprisingly, significant impact on its overall performance and characteristics of the hydraulic setting mixture. This is surprising in that it is generally known that it is difficult to incorporate lignin in construction products that require strength and resistance, without negatively impacting these properties.

[0026] As discussed herein, the present disclosure provides for a redispersible dry powder (RDP) comprising components that include (a) 40 to 80 weight percent (wt.%) of a latex polymer; (b) 10 to 30 wt.% of a filler; and (c) 5 to 50 wt.% lignin, where the wt.% are based on the total weight of the RDP and a sum of the components totals 100 wt.%. Preferably, the RDP of the present disclosure can include 50 to 70 wt.% of the latex polymer, where the wt.% is based on the total weight of the RDP. More preferably, the RDP of the present disclosure can include 60 to 70 wt.% of the latex polymer, where the wt.% is based on the total weight of the RDP.

[0027] For the various embodiments, (a) the latex polymer can be formed from a latex dispersion comprising vinyl acetate-based polymer particles. For the various embodiments, the vinyl acetate-based polymer particles can be formed of a copolymer formed with 50 to 95 weight percent (wt.%) vinyl acetate and 50 to 5 wt.% of a comonomer selected from the group consisting of styrene, butadiene, vinyl versatate, propionate, laurate, vinyl chloride, vinylidene chloride, ethylene, acrylates and combinations thereof, where the wt.% is based on the total weight of the copolymer. In more specific embodiments, the vinyl acetate-based polymer particles can be formed of a copolymer formed with 50 to 95 wt.% vinyl acetate and 50 to 5 wt.% of a comonomer selected from the group consisting of ethylene, vinyl versatate and combinations thereof. In a specific embodiment, the vinyl acetate-based polymer particles are formed from at least one of a vinyl acetate-ethylene copolymer and a vinyl acetate / vinyl- versatate copolymer. For the various embodiments, the vinyl acetate-based polymer particles provide the latex dispersion with a solids content of 40 to 65 wt.%, where the wt.% is based on the total weight of the latex dispersion.

[0028] The process of preparing the vinyl acetate-based polymer particles useful in the present invention may be conducted by free-radical polymerization, such as suspension polymerization or emulsion polymerization, from the monomers described above. Emulsion polymerization is a preferred process. The total weight concentration of monomers for preparing the vinyl acetate- based polymer particles is equal to 100%. A mixture of monomers for preparing the vinyl acetate-based polymer particles may be added neat or as an emulsion in water; or added in one or more additions or continuously, linearly or nonlinearly, over the reaction period of preparing the vinyl acetate-based polymer particles. Temperatures suitable for emulsion polymerization processes may be lower than 100 °C, in the range of from 30 to 95 °C, or in the range of from 50 to 90 °C. Multistage free-radical polymerizations using the monomers described above can be used, in which at least two stages are formed sequentially.

[0029] In the polymerization process of preparing the vinyl acetate-based polymer particles, free radical initiators may be used. The polymerization process may be thermally initiated or redox initiated. Examples of suitable free radical initiators include hydrogen peroxide, t-butyl hydroperoxide, cumene hydroperoxide, ammonium and / or alkali metal persulfates, sodium perborate, perphosphoric acid, and salts thereof; potassium permanganate, and ammonium or alkali metal salts of peroxy di sulfuric acid. The free radical initiators may be used typically at a level of 0.01 to 3.0% by weight, based on the total weight of monomers. Redox systems comprising the above-described initiators coupled with a suitable reductant may be used in the polymerization process. Examples of suitable reductants include sodium sulfoxylate formaldehyde, ascorbic acid, isoascorbic acid, alkali metal and ammonium salts of sulfur- containing acids, such as sodium sulfite, bisulfite, thiosulfate, hydrosulfite, sulfide, hydrosulfide or dithionite, formadinesulfinic acid, acetone bisulfite, glycolic acid, hydroxymethanesulfonic acid, glyoxylic acid hydrate, lactic acid, glyceric acid, malic acid, tartaric acid and salts of the preceding acids. Metal salts of iron, copper, manganese, silver, platinum, vanadium, nickel, chromium, palladium, or cobalt may be used to catalyze the redox reaction. Chelating agents for the metals may optionally be used.

[0030] In the polymerization process of preparing the vinyl acetate-based polymer particles a surfactant may be used. The surfactant may be added prior to or during the polymerization of the monomers, or combinations thereof. A portion of the surfactant can also be added after the polymerization. These surfactants may include anionic and / or nonionic emulsifiers. Examples of suitable surfactants include alkali metal or ammonium salts of alkyl, aryl, or alkylaryl sulfates, sulfonates or phosphates; alkyl sulfonic acids; sulfo succinate salts; fatty acids; ethylenically unsaturated surfactant monomers; and ethoxylated alcohols or phenols. In some preferred embodiments, the alkali metal or ammonium salts of alkyl, aryl, or alkylaryl sulfates surfactant are used. The surfactant used is usually from 0.1% to 6% by weight, preferably from 0.3% to 1.5% by weight, based on the weight of total monomers used for preparing the vinyl acetate- based polymer particles. After completing the polymerization of the vinyl acetate-based polymer particles, the obtained vinyl acetate-based polymer particles may be neutralized by one or more bases as neutralizers to a pH value, for example, at least 4, from 4 to 10, from 6 to 10. or from 7 to 9. Examples of suitable bases include ammonia; alkali metal or alkaline earth metal compounds such as sodium hydroxide, potassium hydroxide, calcium hydroxide, zinc oxide, magnesium oxide, sodium carbonate; primary, secondary, and tertiary amines, such as triethyl amine, ethylamine, propylamine, monoisopropylamine, monobutylamine, hexylamine, ethanolamine, diethyl amine, dimethyl amine, di-npropylamine, tributylamine, triethanolamine, dimethoxyethylamine, 2-ethoxyethylamine, 3-ethoxypropylamine, dimethylethanolamine, diisopropanolamine, morpholine, ethylenediamine, 2-diethylaminoethylamine, 2,3- diaminopropane. 1,2-propylenediamine, neopentanediamine, dimethylaminopropylamine, hexamethylenediamine, 4,9-dioxadodecane-l,12-diamine, polyethyleneimine or polyvinylamine; aluminum hydroxide; or mixtures thereof.

[0031] For the various embodiments, the vinyl acetate-based polymer particles can have a weight average molecular weight of 80,000 or more, 100,000 or more, or even 200,000 or more. The weight average molecular weight may be determined by SEC analysis using a polystyrene standard. For the various embodiments, the vinyl acetate-based polymer particles of the present disclosure may have a glass transition temperature (Tg) of about -30 °C to 35 °C, or from - 10 °C to 20 °C. For the various embodiments, the vinyl acetate-based polymer particles may have a particle size of from 0.1 micrometers (pm) to 2.5 pm, from 0.2 pm to 1.0 pm, or from 0.3 pm to 600 pm.

[0032] The latex polymer can also include other polymer particles besides those derived from the latex dispersion comprising vinyl acetate-based polymer particles discussed herein. For example, the latex polymer of the present disclosure can also include or be formed from styrenebutadiene copolymers. Particles of styrene-butadiene copolymers can be formed in a variety of ways known to those skilled in the art, including emulsion polymerization in a water-based emulsion in which the styrene and butadiene monomers are dispersed with at least one suitable surfactant, initiated with a water-soluble initiator, such as potassium persulfate and the polymerization allowed to proceed to form and subsequently precipitate the latex dispersion of particles from which the latex polymer is derived. Particles of styrene-butadiene copolymers can also be formed using a solution polymerization technique as is known in the art. The latex polymer of the present disclosure can also be a blend of two or more of the particles discussed herein. For example, vinyl acetate-based polymer particles, as provided herein, can be a blend of two or more of the vinyl acetate-ethylene copolymer, the vinyl acetate / vinyl-versatate copolymer, vinyl acetate / ethylene / vinyl acetate-neohexene (VAE / VeoVA)), ethylene / vinyl chloride / vinyl laurate terpolymer; vinyl acetate / ethylene / vinyl ester of versatic acid terpolymer, and particles of styrene-butadiene copolymers. Other blends from the possible particles discussed herein are also possible.

[0033] For the various embodiments, the latex dispersion can also include a stabilizer. For example, the latex dispersion can include 4 to 15 wt.% of a stabilizer, where the wt.% is based on the total weight of the latex dispersion. For the various embodiments, the stabilizer can be polyvinyl alcohol having a degree of hydrolysis of 85 to 90 mole percent. For the various embodiments, the polyvinyl alcohol can be derived from polyvinyl acetate in which 85 to 95% of the vinyl acetate groups are hydrolyzed to vinyl alcohol units. In addition, other possible stabilizers can include partially hydrolyzed cellulose derivatives such as ethyl hydroxyethyl cellulose, 2-hydroxyethyl cellulose, hydroxybutyl methyl cellulose, hydroxypropyl methyl cellulose; partially hydrolyzed rubbers such as acacia gum and xanthan gum poly(meth)acrylic acid and derivatives; and styrene maleic acid copolymers and derivatives. For the various embodiments, the stabilizer of the present disclosure can have a weight average molecular weight in a range of 10,000 to 200,000 g / mol.

[0034] Forming the latex polymer from the latex dispersion, as provided herein, can be accomplished using spray drying techniques as are known. Briefly, spray drying can be carried out in customary spray drying plants, with atomization being carried out by means of single- fluid, two-fluid or multifluid nozzles or a rotary disc atomizer. In general, air, nitrogen or nitrogen enriched air may be employed as the drying gas, the inlet temperature of the drying gas generally not exceeding 200 °C, preferably from 110 °C to 180 °C, more preferably from 120 °C to 150 °C. The outlet temperature may generally be from 45 °C to 100 °C, preferably from 45 °C to 70 °C, depending on the plant, the Tg of the latex polymer particles and the desired degree of drying. Operating nozzle pressures of the spray drying process can be in a range of 2 to 5 bar. In one example, the viscosity of the aqueous mixture to be spray-dried may be adjusted via the solids content so that a value of less than 1000 mPas (Brookfield viscosity at 20 rpm and 23 °C), preferably less than 250 mPas is obtained. The solids content of the mixture to be spray-dried may generally be from 25% to 60% by weight, preferably from 35% to 50% by weight, based on the total weight of the mixture. The resulting latex polymer can be a free-flowing powder.

[0035] As discussed herein, the components of the RDP also include (b) 10 to 30 wt.% of a filler, where the wt.% is based on the total weight of the RDP. Preferably, the RDP of the present disclosure can include 15 to 25 wt.% of the filler, where the wt.% is based on the total weight of the RDP. More preferably, the RDP of the present disclosure can include 17 to 23 wt.% of the filler, where the wt.% is based on the total weight of the RDP. For the various embodiments, (b) the filler can be selected from the group consisting of silica sand, dolomite, limestone, perlite, expanded polystyrene, hollow glass spheres, rubber crumbs, fly ash and combinations thereof. For the various embodiments, the filler can have a particle size of no more than 1.0 mm.

[0036] For the various embodiments, the components of the RDP can include (c) 5 to 50 wt.% lignin, where the wt.% is based on the total weight of the RDP. Preferably, the RDP of the present disclosure can include 10 to 50 wt.% lignin, where the wt.% is based on the total weight of the RDP. In another preferred embodiment, the RDP of the present disclosure can include 10 to 25 wt.% lignin, where the wt.% is based on the total weight of the RDP. More preferably, the RDP of the present disclosure can include 15 to 20 wt.% lignin, where the wt.% is based on the total weight of the RDP. For the various embodiments, the lignin can have a weight average molecular weight of 1,000 to 100,000 Daltons. In additional embodiments, the lignin can have a weight average molecular weight of 5,000 to 100,000 Daltons. In further embodiments, the lignin can have a weight average molecular weight of 10,000 to 100,000 Daltons.

[0037] For the various embodiments, the RDP of the present disclosure can include from 6 wt.% lignin to 50 wt.% lignin based on the total weight of latex polymer and lignin contained in the RDP. Preferably, the RDP of the present disclosure can include from 10 wt.% lignin to 35 wt.% lignin based on the total weight of latex polymer and lignin contained in the RDP.

[0038] For the various embodiments, the lignin used in the RDP can be selected from the group consisting of a Kraft lignin, soda lignin, organosolv lignin, hydrolytic lignin and combinations thereof. The lignins of the present disclosure can be produced using soft wood and / or hard wood sources. Kraft lignin is obtained from the kraft pulping process, which uses a mixture of sodium hydroxide and sodium sulfide to break down wood fibers. Kraft lignin typically has a high weight average molecular weight (e.g., 10,000 to 100,000 Daltons), and contains a high content of condensed phenolic units. Soda lignin is produced using a sodium hydroxide solution in the soda pulping process, where the resulting lignin has a high weight average molecular weight (e.g., 5,000 to 15,000 Daltons), and contains a higher proportion of guaiacyl units. Organosolv lignins are isolated using organic solvents, such as ethanol or methanol and have weight average molecular weights of 1,000 to 20,000 Daltons. Hydrolytic lignin is produced through acid hydrolysis of plant biomass and can have a weight average molecular weights of around 1,000 Daltons.

[0039] The RDP of the present disclosure, or the hydraulic setting mixture that contains the RDP, may further comprise additional components or additives. For example, for applications in which the hydraulic setting mixture should have good workability (e.g. tile adhesives), the RDP of the present disclosure, or the hydraulic setting mixture that contains the RDP, may further include one or more stabilizers selected from lime, air entraining agents (the presence of which leads to air filled voids in hydraulic mixtures), coalescents, superplasticizers, rheological modifiers and mixtures thereof. Further additives can be selected from organic or inorganic thickening agents and / or secondary water retention agents, anti-sag agents, wetting agents, defoamers, dispersants, calcium complexing agents, retarders, accelerators, water repellents, biopolymers and fibers, all of which are well known in the art and are available from commercial sources. Preferably, when included in the RDP of the present disclosure, such additives are present in amounts from 0.001 to 5 weight percent, based on the total dry weight of the hydraulic mortar.

[0040] An anti-caking agent is often dispersed with the RDP of the present disclosure. Anticaking agents are useful when spray drying a dispersion to isolate the particles. Typical anticaking agents include mineral filler such as calcium carbonate, kaolin, barium sulphate, titanium oxide, talc, hydrated alumina, bentonite, calcium sulphoaluminate and silica. The concentration of anti-caking agent in the RDP can typically be 50 wt.% or less, preferably 20 wt.% or less, more preferably 15 wt.% or less, still more preferably 10 wt.% or less and even more preferably 5 wt.% or less relative to total RDP weight. The RDP can be free of anti-caking agent, but can contain 0.5 wt.% or more, preferably 2 wt.% or more and more preferably 5 wt.% or more relative to total RDP weight.

[0041] For the various embodiments, the components of the RDP can further include (d) 0.01 to 0.5 wt.% of a sulfosuccinate surfactant, where the wt.% are based on the total weight of the RDP and a sum of the components (e.g., (a) through (d)) totals 100 wt.%. Preferably, the components of the RDP can further include (d) 0.05 to 0.20 wt.% of a sulfosuccinate surfactant, where the wt.% are based on the total weight of the RDP and a sum of the components totals 100 wt.%. More preferably, the components of RDP can further include (d) 0.07 to 0.15 wt.% of a sulfosuccinate surfactant, where the wt.% are based on the total weight of the RDP and a sum of the components totals 100 wt.%.

[0042] For the various embodiments, the (d) sulfo succinate surfactant is of Formula I: MSO3— R1— (— COOR2)n(Formula I) where M represents a hydrogen, metal or ammonium cation; R ' represents a linear or branched, saturated or unsaturated C1-C10 alkylene moiety that is optionally substituted with one or more hydroxyl, halogen, nitro and / or cyano groups; each R2independently represents a linear or branched, saturated or unsaturated C1-C22 alkyl radical or a hydrogen, metal or ammonium cation; and n represents an integer from 1 to 10. Preferably, n is an integer from 1 to 5.

[0043] More preferably, in Formula I, n represents 2 and, still more preferably, the surfactant is a compound according to Formula (II) or Formula (III)

[0044] Formula (II

[0045] Still more preferably, the sulfosuccinate surfactant according to Formula I can be selected from the group consisting of a dioctyl sulfo succinate salt, a dihexyl sulfo succinate salt and combinations thereof. Still more preferably, the surfactant is a dioctyl sulfosuccinate salt, most preferably sodium dioctyl sulfosuccinate, i.e. sodium l,4-bis(2-ethylhexoxy)-l,4-dioxobutane-2- sulfonate.

[0046] The embodiments of the present disclosure also provide for a dry hydraulic setting mixture. For the various embodiments, the dry hydraulic setting mixture includes a hydraulic binder and the RDP as provided herein, where the RDP can help to enhance the bond strength of hydraulic setting mixture and improve the workability of dry hydraulic setting mixture. For the various embodiments, the dry hydraulic setting mixture can include 0.2 to 10 wt.% of the RDP of the present disclosure, where the wt.% are based on a total dry weight of the hydraulic binder and the RDP. For the various embodiments, the hydraulic binder can be selected from the group consisting of a Portland cement-based binder, lime aluminous cement and combinations thereof. Preferably, the hydraulic binder is cement and more preferably, the hydraulic binder is Portland cement, in particular, the types of CEM I, II, III, IV and V, and / or alumina cement (aluminate cement) and combinations thereof.

[0047] Applications for RDP of present disclosure can include construction adhesives, tile adhesives, joint mortars, external wall putty, building binders, filling compositions like concrete repair joints, crack isolation membranes, and waterproofing membrane applications, among other applications.

[0048] Examples

[0049] Some embodiments of the disclosure shall now be further described by way of exemplification only. All ratios, parts and percentages are expressed by dry weight unless otherwise specified. All components purchased from commercial vendors and used as received unless otherwise noted.

[0050] Table 1 - Materials list

[0051] Experimental Procedures

[0052] In the following Examples (EX) and Comparative Examples (CE), different proportions of dolomite were replaced with lignin as the filler for the RDP compositions. Product compositions are seen in Table 2, below, for which 100 grams total weight of each EX and CE were prepared. Each of the components were weighted and placed into a plastic container, which was sealed and shaken by hand for 3 minutes to mix the dry components into a homogeneous composition.

[0053] After preparation the performance of each EX and CE was evaluated in a Brazilian standard cementitious based tile adhesive formulation, according to ABNT NBR 14081-2 (Industrialized adhesive mortar for laying ceramic tiles) and Execution of the standard substrate and application of the mortar for testing, ABNT NBR 13817 - Ceramic tiles for cladding - Classification.

[0054] Table 2 - RDP Composition of EX and CE

[0055] CBTA formulation: 22% Cement CPU E40, 0.22% MKX 40000 PF01, 1% RDP (CEA or EXI), 76,78% Areia M60. W / S = 0,195.

[0056] Table 3 - Results comparing EXI and CEA (both are RDP extended with fillers)

[0057] Table 3 - Comparison between Adhesive Formulation CE B, CE D (DLP 2000, pure

[0058] VAE) and CE C, CE E (CE A)

[0059] Table 3 provides a comparison between the pure RDP (DLP 2000) and the extended RDP with fillers -no lignin added) Table 4 - Cl CBTA formulation prepared with lignin. By replacing 50% of RDP is possible to achieve Cl performance as per EN 12004,

[0060] Data Analysis

[0061] Table 3 provides a comparative example showing the test results without any additives.

[0062] Table 4 provides examples that show the benefit of adding lignin in the composition of redispersible polymers. These examples show the performance of the product is not changed with the addition of the lignin.

Claims

CLAIMS:

1. A redispersible dry powder, comprising: components that include:(a) 40 to 80 weight percent (wt.%) of a latex polymer;(b) 10 to 30 wt.% of a filler; and(c) 5 to 50 wt.% lignin; wherein the wt.% are based on the total weight of the redispersible dry powder and a sum of the components totals 100 wt.%.

2. The redispersible dry powder of claim 1, wherein lignin is selected from the group consisting of a Kraft lignin, soda lignin, organosolv lignin, hydrolytic lignin and combinations thereof.

3. The redispersible dry powder of any one of claims 1-2, wherein the lignin has a weight average molecular weight of 10,000 to 100,000 Daltons.

4. The redispersible dry powder of any one of claims 1-3, wherein the redispersible dry powder includes (c) 10 to 25 wt.% lignin.

5. The redispersible dry powder of any one of claims 1-3, wherein the redispersible dry powder includes (c) 15 to 20 wt.% lignin.

6. The redispersible dry powder of any one of claims 1-5, wherein the components of the redispersible dry powder further include (d) 0.01 to 0.5 wt.% of a sulfosuccinate surfactant, wherein the wt.% of the components are based on the total weight of the redispersible dry powder and a sum of the components totals 100 wt.%.

7. The redispersible dry powder of claim 6, wherein the redispersible dry powder includes(d) 0.05 to 0.2 wt.% of the sulfosuccinate surfactant.

8. The redispersible dry powder of any one of claims 6-7, wherein the (d) sulfosuccinate surfactant is of Formula I:MSO3— R1— (— COOR2)n(Formula I) wherein M represents a hydrogen, metal or ammonium cation; R ' represents a linear or branched, saturated or unsaturated Cl -CIO alkylene moiety that is optionally substituted with one or more hydroxyl, halogen, nitro and / or cyano groups; each R2independently represents a linear or branched, saturated or unsaturated C1-C22 alkyl radical or a hydrogen, metal or ammonium cation; and n represents an integer from 1 to 10.

9. The redispersible dry powder of claim 8, wherein the sulfo succinate surfactant according to Formula I is selected from the group consisting of a dioctyl sulfo succinate salt, a dihexyl sulfo succinate salt and combinations thereof.

10. The redispersible dry powder of any one of claims 1-9, wherein (b) the filler is selected from the group consisting of silica sand, dolomite, limestone, perlite, expanded polystyrene, hollow glass spheres, rubber crumbs, fly ash and combinations thereof.

11. The redispersible dry powder of any one of claims 1-10, wherein (a) the latex polymer is formed from a latex dispersion comprising vinyl acetate-based polymer particles.

12. The redispersible dry powder of claim 11, wherein the vinyl acetate-based polymer particles are formed of a copolymer formed with 50 to 95 weight percent (wt.%) vinyl acetate and 50 to 5 wt.% of a comonomer selected from the group consisting of styrene, butadiene, vinyl versatate. propionate, laurate, vinyl chloride, vinylidene chloride, ethylene, acrylates and combinations thereof, where the wt.% is based on the total weight of the copolymer.

13. The redispersible dry powder of any one of claims 11-12, wherein the vinyl acetate-based polymer particles are formed from at least one of a vinyl acetate-ethylene copolymer and a vinyl acetate / vinyl- versatate copolymer.

14. A dry hydraulic setting mixture, comprising: a hydraulic binder; and0.2 to 10 wt.% of the redispersible dry powder of any one of claims 1-13, wherein the wt.% are based on a total dry weight of the hydraulic binder and the redispersible dry powder.

15. The hydraulic setting mixture of claim 14, wherein the hydraulic binder is selected from the group consisting of a Portland cement-based binder, lime aluminous cement and combinations thereof.

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