WO2025064125A1

WO2025064125A1 - Granular wetting agent for dry mix

Info

Publication number: WO2025064125A1
Application number: PCT/US2024/043129
Authority: WO
Inventors: Sabrina SALVATI; Jean-Paul Lecomte; Jouko Vyorykka; Eduardo OLIVEIRA CRUZ; Margarita Perello
Original assignee: Dow Global Technologies LLC; Dow Silicones Corp
Current assignee: Dow Global Technologies LLC; Dow Silicones Corp
Priority date: 2023-09-18
Filing date: 2024-08-21
Publication date: 2025-03-27
Anticipated expiration: 2026-03-18

Abstract

A granular wetting agent contains adsorbent inorganic powdered carrier, water-soluble polymer binder adhered to the carrier, and a non-ionic surfactant adhered to the carrier. The granular wetting agent can be used in dry mixes, such as mortar, grout and concrete, to improve wetting of the dry mix. It may be especially useful when the filler in the dry mix contains polymer particles, such as polyurethane or polyisocyanurate.

Description

GRANULAR WETTING AGENT FOR DRY MIX

FIELD

This invention relates to the field of dry mix cement compositions.

INTRODUCTION

Concretes, mortars and grouts are frequently stored and shipped as a dry mix that contains cement, filler and additives. The dry mix is blended with water just before use to make a wet mix, which is used in the intended end-use and allowed to cure.

Fillers have traditionally been inorganic materials, such as sand or aggregate. More recently, ground organic polymer fillers have been added to concretes and mortars to replace some or all of the inorganic fillers. See, for example, Rahman et al., “Recycled Polymer Materials as Aggregates for Concrete and Blocks”, 27 Journal of Chemical Engineering, IEB 53 (2012). Organic polymer fillers can provide a useful outlet for recycled polymers, and can produce concretes and mortars that are lighter and have improved flexibility and thermal insulation.

Polymer used in fillers include polyethylene, polypropylene, polystyrene, PET, polyurethane, polyisocyanurate and polyurethane-polyisocyanurate copolymers. However, some polymer fillers, including polyurethanes, polyisocyanurates and polyurethane-polyisocyanurate copolymers (collectively called PU/PIR polymers), are strongly hydrophobic with low surface energy. Water that is added to a dry mix containing hydrophobic polymer fillers does not effectively wet the fillers unless a large quantity of water is used. It is difficult to maintain a homogenous wet mix because the water and polymer fillers separate easily.

Wetting agents can help to effectively wet the ground polymer fillers and incorporate them into the wet mix. However, many effective wetting agents for polymer fillers are liquids, which cannot be used as part of a dry mix. What is needed is a dry granular wetting agent that is effective to wet polymer fillers and incorporate them into a cementitious wet mix.

SUMMARY

One aspect of this invention is a granular wetting agent for use in a cementitious dry mix comprising the following components:

(a) An adsorbent inorganic powdered carrier;

(b) At least 5 weight percent of a nonionic surfactant adhered to the carrier; and

(c) A water-soluble polymer binder adhered to the carrier in a quantity sufficient to bind the surfactant to the carrier; wherein all weight percentages are based on the combined weight of components (a), (b) and (c).

A second aspect of this invention is dry mix comprising:

(a) A dry unhydrated particulate cement;

(b) From 40 to 95 volume percent of a filler; and

(c) A granular wetting agent that contains, (i) An adsorbent inorganic powdered carrier;

(ii) At least 1 weight percent of a nonionic surfactant adhered to the carrier; and

(iii) A water-soluble polymer binder adhered to the carrier in a quantity sufficient to bind the surfactant to the carrier, in a quantity sufficient to enable wetting of the filler when the dry mix is mixed with water.

A third aspect of this invention is a wet mix composition comprising a dry mix from the second aspect of the invention; and a quantity of water sufficient to homogeneously wet the dry mix.

A fourth aspect of this invention is a cured mortar, grout or concrete composition comprising a cured wet mix from the third aspect of the invention.

The granular wetting agents of this invention are dry powders that can be incorporated into a dry mix. They allow homogeneous integration and wetting of dry mixes that contain ground polymers such as PU/P1R polymer foam, using low amounts of water. In some embodiments, the cured wet mix may have mechanical properties that are improved over a wet mix made using the equivalent liquid wetting agent.

DETAILED DESCRIPTION

Granular Wetting Agent

The granular wetting agents of this invention contain an adsorbent inorganic powdered carrier, a nonionic surfactant and a water-soluble polymer binder. The binder and the surfactant are adhered to the carrier. In some embodiments, the sur factant may be adsorbed on the carrier, and the binder may form a coating over both. In some embodiments, a mixture of binder and sur factant may coat the carrier. In some embodiments, both situations may exist. In some embodiments, the coating causes particles of carrier to adhere together to form agglomerated particles larger than the earner particles.

In many embodiments, the carrier is a porous inorganic material such as a gypsum, calcium sulfate, silica or aluminosilicate. Examples of suitable aluminosilicate compounds include zeolites, feldspar, sodalite and octahedrally coordinated aluminum, such as andalusite, kyanite and sillimanite.

In some embodiments, the carrier has high surface area. For example, in some embodiments, the carrier has a Brunauer-Emmett-Teller (BET) surface area of at least 100 nr/g or at least 200 m²/g or at least 300 m²/g or at least 400 m²/g or at least 500 m²/g. In some embodiments, the carrier has a BET surface area of at most 2000 m²/g or at most 1500 m²/g or at most 1000 m²/g or at most 800 m²/g or at most 600 m²/g.

In some embodiments, the carrier has an average pore size of at least 3 A or at least 4 A. In some embodiments, the carrier has an average pore size of at most 100 A or at most 50 A or at most 25 A or at most 15 A or at most 10 A or at most 7 A.

In some embodiments, the carrier has an average pore volume of at least 5 cm³/g or at least 10 em’/g. In some embodiments, the carrier has an average pore volume of at most 60 em’/g or at most 40 cm³/g. In some embodiments, the carrier can undergo a pozzolanic reaction with the cement in the dry mix. Pozzolans are known to densify and improve the durability of concretes and mortars that they are added to, as well as reducing greenhouse gas emission. Selecting a carrier that can undergo pozzolanic reaction can provide some or all of these benefits.

In some embodiments, an aluminosilicate carrier may have an Si/Al molar ratio from 1 to 1000. All individual values and subranges of a molar ratio from 1 to 1000 are disclosed and included herein, including from 1 to 100, from 1 to 200, from 1 to 300, from 1 to 400, from 1 to 500, from 1 to 600, from 1 to 700, from 1 to 800, from 1 to 900, from 100 to 1000, from 200 to 1000, from 300 to 1000, from 400 to 1000, from 500 to 1000, from 600 to 1000, from 700 to 1000, from 800 to 1000, or from 900 to 1000.

In certain embodiments, the carrier is a zeolite. In some embodiments, the zeolite has a silica to alumina ratio (SiGh/AbOj) of at least 1 or at least 1.5 or at least 1.7 or at least 1.8 or at least 1.9 or at least 2. In some embodiments, the zeolite has a silica to alumina ratio (SiOz/AlzOa) of at most 10 or at most 5 or at most 3 or at most 2.5 or at most 2.3 or at most 2.2.

In some embodiments, the zeolite has static water adsorption capacity (at 25°C and 50% relative humidity) of at least 15 weight percent or at least 18 weight percent or at least 20 weight percent or at least 21 weight percent. In some embodiments, the zeolite has static water adsorption capacity (at 25°C and 50% relative humidity) of at most 50 weight percent or at most 35 weight percent or at most 30 weight percent or at most 25 weight percent.

In some embodiments, the zeolite is a class A zeolite. Examples of suitable class A zeolites include 3A, 4A and 5A zeolites. In some embodiments, the zeolite comprises a 4A zeolite.

Suitable zeolites are commercially available, such as under the Siolite, Advan and STPP trademarks. Other zeolites are available in nature or can be manufactured by known processes such as are described in Introduction to Zeolite Science and Practice - 3rd Revised Edition (J. Cejka, H. at al - editors) at Chapter 3 (Synthesis of Zeolites by Jihing Yu).

In some embodiments, the carrier has a mean (D50) particle size of at least 1 micron or at least 2 microns. In some embodiments, the carrier has a mean particle size of at most 100 microns or at most 50 microns or at most 20 microns or at most 10 microns or 6 microns. Selecting small carrier particles with high surface area increases the ratio of surfactant and binder as compared to carrier. This is particularly true when the binder adheres multiple carrier particles together to form a larger granule as the particulate wetting agent is dried.

In some embodiments, the carrier is white. This may be important in some mortars and grouts, where a white, clean appearance is often desirable.

The granular wetting agents contain a nonionic surfactant that is effective to wet a filler. Nonionic surfactants are well-known and commercially available. They comprise a hydrophobic group linked to a nonionic hydrophilic group.

Examples of hydrophobic groups include fatty aliphatic groups and fatty aliphatic-aromatic groups that contain on average at least 8 carbon atoms or at least 10 carbon atoms or at least 12 carbon atoms. In some embodiments, the fatty aliphatic groups and fatty aliphatic-aromatic groups contain on average at most 24 carbon atoms or at most 20 carbon atoms or at most 18 carbon atoms or most 16 carbon atoms. Other examples of hydrophobic groups include hydrophobic polymers such as polyethylene, polypropylene and polypropylene oxide. In some embodiments, the hydrophobic group is an organic (carbon-backbone) moiety, as opposed to a siloxane (silicon-backbone) moiety.

Examples of nonionic hydrophilic groups include alkylene glycol groups, polyalkylene glycol polymers and oligomers and glucose -derived groups.

Major types of nonionic surfactants include fatty alcohol ethoxylates, alkyl phenol ethoxylates, fatty acid alkoxylates and fatty glucoside derivatives. Examples of commonly used nonionic surfactants include alkyl glucosides such as octyl, decyl and lauryl glucoside, Polysorbate 20, Polysorbate 80 and lsolaureth-10.

In some embodiments, the nonionic surfactant comprises a fatty alcohol derivative in which the hydroxyl group has been substituted with a hydrophilic group containing one or more ethylene glycol or propylene glycol groups. In some embodiments, the fatty alcohol derivative is aliphatic or alkyl. The number of carbon atoms in the fatty alcohol derivative is previously described. In some embodiments, the hydrophilic group contains on average at least one ethylene glycol or propylene glycol group. In some embodiments, the hydrophilic group contains on average at most six ethylene glycol or propylene glycol groups or at most four ethylene glycol or propylene glycol groups or at most three ethylene glycol or propylene glycol groups or at most two ethylene glycol or propylene glycol groups. In some embodiments, the hydrophilic group contains on average a single ethylene glycol or propylene glycol group. Examples of appropriate surfactants are sold under the TERGITOL™ and TRITON™ trademarks.

In some embodiments, the nonionic surfactant is siloxane surfactant, in which the hydrophobic group comprises a siloxane oligomer or polymer. Examples of such siloxane surfactants are described in US Publication 2015/0259249 Al.

The granular wetting agents contain a water-soluble polymer binder adhered to the carrier. The binder binds the surfactant to the carrier, until the binder dissolves in the wet mix. In some embodiments, the binder further causes particles of coated carrier to agglomerate and adhere together, so that the average particle size of the granular wetting agent in this invention is larger than the average particle size of the carrier particles.

In some embodiments, the binder is a film-forming polymer. The concept of film-forming polymers is well understood. “Film-forming” means that a substance is capable of forming a film upon application to a solid surface. In the case of water-soluble binders used in this invention, the binder is applied as an aqueous solution and, as water in the solution evaporates, the polymer in the solution coalesces to form a continuous film on the support, which may also cause particles of support to adhere together. In some cases, the film-forming ability of polymers increases with lower molecular weight and/or lower Tg and decreases with higher molecular weight and/or higher Tg. Examples of water-soluble polymers that are useful in the binder include some polyacrylic acid polymers and polyvinyl alcohol polymers. All of these water-soluble polymers are known and commercially available.

Polyacrylic acid (PAA) polymers are polymers that contain repeating units derived from acrylic acid or methacrylic acid. In some embodiments, the PAA polymer is a homopolymer, in which essentially all repeating units are derived from acrylic acid or methacrylic acid.

In some embodiments, the PAA polymer is a copolymer in which some repeating units are derived from acrylic acid or methacrylic acid and some repeating units are derived from a comonomer. In some embodiments, at least 1 weight percent of repeating units in the PAA polymer are derived from acrylic acid or methacrylic acid, or at least 3 weight percent or at least 5 weight percent or at least 7 weight percent or at least 9 weight percent. In some embodiments, up to 100 weight percent of repeating units in the PAA polymer are derived from acrylic acid or methacrylic acid, or at most 50 weight percent or at most 25 weight percent or at most 20 weight percent or at most 15 weight percent or at most 12 weight percent. In some embodiments, at least 50 weight percent of repeating units in the PAA polymer are derived from comonomers, or at least 75 weight percent or at least 80 weight percent or at least 85 weight percent or at least 88 weight percent. In some embodiments, up to 99 weight percent of repeating units in the PAA polymer are derived from comonomers, or up to 97 weight percent or up to 95 weight percent or up to 93 weight percent or up to 91 weight percent.

Suitable comonomers include unsaturated monomers capable of free -radical polymerization. Examples of suitable comonomers include methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethylene, propylene and styrene. In some embodiments, the comonomer is ethylene.

In some embodiments, at least 10 percent of acid groups in the PAA polymer remain in an acidic state (i.e. the hydrogen has not been neutralized with a base or otherwise replaced with another substituent), or at least 30 percent or at least 50 percent or at least 70 percent or at least 80 percent. In some embodiments, essentially all of acid groups in the polyacid polymer (up to 100 percent) remain in an acidic state.

Suitable PAA polymers are commercially available, such as under the ACUSOL™ and NUCREL™ trademark. Other PAA polymers can be made by free-radical polymerization of acrylic acid or methacrylic acid, optionally with comonomers, according to known processes. See for example, US Patent 2,289,540 and Zahran et al., “Poly Acrylic Acid: Synthesis, Aqueous Properties and their Applications as Scale Inhibitor”, published by KGK Rubberpoint at https://www.kgk-rubberpoint.de/wp- content/uploads/2016/08/KGK_7-8_2016_53-58.pdf.

Poly -vinyl alcohol (PVOH) polymers are homopolymers or copolymers that contains repeating units derived from vinyl alcohol. In some embodiments, the PVOH polymer is a homopolymer, in which essentially all repeating units are derived from vinyl alcohol. In some embodiments, the PVOH polymer is a copolymer in which some repeating units are derived from vinyl alcohol and some repeating units are derived from a comonomer. Suitable comonomers include unsaturated monomers capable of free-radical polymerization. Examples of suitable comonomers include vinyl acetate, ethylene, propylene and styrene.

Suitable PVOH polymers are commercially available, such as under the trademarks Eval, Soamol, Elvanol and Vinarol. Others can be made by a two-step process of (1) polymerizing ethylene vinyl acetate, optionally with comonomers, to make a vinyl acetate polymer, and (2) hydrolyzing at least some of the pendant acetate groups on the vinyl acetate polymer to form pendant hydroxyl groups. See, for example, European Patent EP 3 564 294 Bl (13 Apr 2022) and Ketels, H. H. T. M. ( 1989). “Synthesis, Characterization and Applications of Ethylene Vinyl Alcohol Copolymers'” [Ph.D. Thesis 1 (Research TU/e / Graduation TU/e), Chemical Engineering and Chemistry], Technische Universiteit Eindhoven. https://doi.org/10.6100/lR316591.

The binder should be water soluble. In some embodiments, the binder is soluble in water at 20°C in quantities up to at least 20 weight percent, or at least 40 weight percent or at least 50 weight percent or at least 60 weight percent, based on the weight of the water. No maximum solubility is desired, but solubility over 100 weight percent or 80 weight percent may be unnecessary for some uses.

The binder should be solid at temperatures at which it is expected to be used. In some embodiments, the binder has a melting temperature of at least 40°C or at least 50°C or at least 60°C or at least 70°C. There is no maximum desired melting temperature, but in some cases a melting temperature over 200°C or 150°C or 100°C may be unnecessary.

The granular wetting agent should contain enough surfactant to be useful in wetting the components of a dry mix and enough binder to hold the surfactant in place on the support.

In some embodiments, the granular wetting agent contains at least 40 weight percent carrier or at least 50 weight percent or at least 55 weight percent or at least 57 weight percent or at least 60 weight percent. In some embodiments, the granular' wetting agent contains at most 95 weight percent carrier or at most 90 weight percent or at most 87 weight percent or at most 85 weight percent or at most 80 weight percent or at most 75 weight percent.

The granular wetting agent contains at least 1 weight percent surfactant. In some embodiments, the granular wetting agent contains at least 3 weight percent surfactant or at least 5 weight percent or at least 8 weight percent or at least 12 weight percent or at least 16 weight percent or at least 20 weight percent or at least 24 weight percent. In some embodiments, the granular wetting agent contains at most 50 weight percent surfactant or at most 40 weight percent or at most 36 weight percent or at most 32 weight percent or at most 28 weight percent.

In some embodiments, the granular wetting agent contains at least 2 weight percent binder or at least 4 weight percent or at least 6 weight percent. In some embodiments, the granular wetting agent contains at most 20 weight percent binder or at most 18 weight percent or at most 16 weight percent.

In some embodiments, the granular wetting agent contains no more than 8 weight percent of a silicone based antifoam agent, or no more than 7 weight percent or no more than 6 weight percent or no more than 5 weight percent or no more than 4 weight percent or no more than 3 weight percent or no more than 2 weight percent or no more than 1 weight percent. Silicone based antifoam agents are not important for the present invention, and the granular wetting agent may contain essentially no (0 weight percent) silicone -based anti-foam agent. Silicone -based antifoam agents are described in detail in Germain, et al., US Patent 5,767,053 (1998). Silicone antifoams are foam regulating compositions which comprise a liquid organopolysiloxane polymer and a filler particle the surface of which has been rendered hydrophobic.

In some embodiments, the nonionic surfactant is an organic surfactant, and the granular wetting agent contains no more than 8 weight percent of polysiloxane compound, or no more than 7 weight percent or no more than 6 weight percent or no more than 5 weight percent or no more than 4 weight percent or no more than 3 weight percent or no more than 2 weight percent or no more than 1 weight percent.

The granular wetting agent can be made by applying the surfactant and the binder to the carrier in an aqueous solution and drying. The surfactant and binder may be applied in two steps:

• First, the surfactant is adsorbed onto the carrier; and

• Second, an aqueous solution of the binder is applied to the carrier and dried.

Alternatively, the surfactant and binder may be applied together in a single step: applying an aqueous solution that contains both the surfactant and the binder to the earner and drying.

The application can be accomplished by simple physical blending, such as with known mixers and impellers. The drying can be accomplished by known means, such as spray-drying or fluidized bed drying. See for example US Patent 4892932A.

The resulting granular wetting agent comprise the carrier with the surfactant and the binder adhered to the carrier. In some embodiments, the surfactant and binder form a coating on the carrier. The proportions of each component are as previously described. In some embodiments, the granular wetting agent contains only a small amount of water that would naturally be absorbed from the air after the drying step. In some embodiments, the granular wetting agent comprises less than 5 weight percent water or less than 3 weight percent water or less than 1 weight percent water.

As stated earlier, in some embodiments the coating causes particles of the carrier to agglomerate and adhere together. In some embodiments, granular wetting agent has a DIO particle size of at least 80 micron or at least 100 micron or at least 120 micron or at least 150 micron. In some embodiments, granular wetting agent has a D90 particle size of at most 1000 micron or at most 800 micron or at most 500 micron. In some embodiments, the median particle size (D50) also falls within these ranges.

The granular wetting agent is in the form of solid particles that can be easily blended into a dry mix.

Dry Mix

The granular wetting agent can be used in dry mixes, which contain: (a) a dry unhydrated particulate cement, (b) from 40 to 95 volume percent of a filler; and (c) a granular wetting agent in a quantity sufficient to wet the filler, which granular wetting agent contains (i) an adsorbent inorganic powdered carrier as previously described; (ii) at least 1 weight percent of a nonionic surfactant as previously described adhered to the carrier; and (iii) a water-soluble polymer binder as previously described adhered to the carrier in a quantity sufficient to bind the surfactant to the earner. It is particularly useful when the filler contains polymer particles such as PU/P1R polymers.

The dry mix contains a dry, unhydrated, particulate cement. In the US, cements are commonly listed in five different categories: Type 1 (ordinary Portland cement); Type 2 (moderate sulfate resistant cement); Type 3 (rapid hardening cement), Type 4 (low heat cement) and Type 5 (high sulfate resistant cement). Any of these cements may be used in the dry mix/mortar. In some embodiments, the cement is ordinary Portland cement. In some embodiments, the cement is a variation of ordinary Portland cement, known as white cement. In some embodiments, the cement is a more specialized cement, such as a high alumina cement or a calcium sulfoaluminate cement. Useful cements are commercially available.

The dry mix also contains a filler. Optionally, the filler may contain ordinary inorganic fillers such as sand. However, the granular wetting agents of this invention may provide more benefits when the filler comprises low surface energy particles such as polymer particles. In some embodiments, the filler comprises both ordinary inorganic fillers and polymer particles.

Examples of inorganic fillers include gravel, silica sand, quartz sand, kaolin, calcium carbonate, magnesium carbonate, talc or mixture thereof. Suitable inorganic fillers are commercially available. Inorganic fillers are known and commercially available.

Examples of polymer particles include particles of polyethylene, polypropylene, polystyrene, PET, and PU/PIR polymers (polyurethane, polyisocyanurate or polyurethane-polyisocyanurate copolymers). In some embodiments, the polymer particles contain PU/PIR polymers. In some embodiments, the polymer particles contain ground, recycled polymer.

Polyurethanes (PU) are a well-known class of polymers. They contain repeating units linked by urethane linkages as illustrated in Formula 1:

(1) -[-R'-NH-CO-O-R²-]- wherein R¹ and R² are independently organic moieties. PU polymers are made by the reaction of a polyisocyanate monomer with a polyol. They are usually highly crosslinked. For more information, see de Souza et al., “Introduction to Polyurethane Chemistry”, published by the American Chemical Society at https://pubs.acs.org/doi/full/10.1021/bk-2021 -1380.ch001. Polyurethanes are commercially used and available in a number of forms, which may be ground to make the filler. In some embodiments, the filler is derived from a rigid foam, which is commonly used for insulation and packaging.

Polyisocyanurates (PIR) are a well-known class of polymers. They contain repeating units linked by isocyanurate linkages as illustrated in Formula 1 :

wherein each R is independently an organic moiety that may be linked to further isocyanurate or urethane linkages. P1R polymers are made by the reaction of a polyisocyanate monomer with a polyester. They are usually highly crosslinked. For more information, see M. lonescu, Chemistry and Technology of Polyols for Polyurethanes (2005). Polyisocyanurates are commercially used and available as rigid insulating foams, such as foam sheets for insulation. They are commercially available under the TRYMER™ and THERMAX™ trademarks.

In some cases, the filler may contain a polyurethane-polyisocyanurate copolymer that contains both urethane and isocyanurate linkages. The copolymers are made by the reaction of polyisocyanate monomer with comonomers that contain both polyol and polyester. Polyurethane-polyisocyanurate copolymers are used as rigid insulating foams, such as foam sheets for insulation. They are commercially available under the TRYMER™ trademark.

Fillers are generally in the form of particles with a size suitable for the intended use. Fillers in large scale uses, such as concreted slabs and walls, may have large particles, whereas filler in mortars and grouts generally have smaller particle sizes. Polymer foam fillers may be more useful in mortars and grouts, and less desirable in concretes that need high compressive strength.

In some embodiments, coarse filler in a large scale concrete structure may have particle sizes up to 50 mm or up to 40 mm or up to 30 mm or up to 20 mm. In some embodiments, the median particle size (D50) for coarse filler is at least 8 mm or at least 9 mm or at least 10 mm. In some embodiments, fine filler in a large scale concrete structure may have a median particle size up to 10 mm or 9.5 mm. In some embodiments, the median particle size for fine filler is at least 0.5 mm or at least 1 mm or at least 2 mm. In some embodiments, filler in a large scale concrete structure may have a mix of fine and coarse filler.

In some embodiments, a filler in a mortar or grout may have a D95 particle size up to 4760 micron (4 mesh) or 4000 micron (5 mesh) or 3360 micron (6 mesh) or 2830 micron (7 mesh) or 2380 micron (8 mesh). In some embodiments, a filler in a masonry mortar may have a DI 0 particle size of at least 74 micron (200 mesh) or at least 88 micron (170 mesh) or at least 105 micron (140 mesh) or at least 149 micron (100 mesh). In some embodiments, the filler meets the particle size profile in ASTM C144. In some embodiments, the filler meets the coarse particle size profile in ASTM C404. In some embodiments, the filler meets the fine particle size profile in ASTM C404. Polymer fillers may be substantially lighter than traditional inorganic fillers. In some embodiments, a polymer filler has a density of at most 1 g/cm³ or at most 0.9 g/cm³ or at most 0.8 g/cm³ or at most 0.5 g/cm³ or at most 0.3 g/cm³ or at most 0.1 g/cm³ or at most 0.08 g/cm³ or at most 0.06 g/cm³. In some embodiments, a polymer filler has a density of at least 0.005 g/cm³ or at least 0.010 g/cm³ or at least 0.015 g/cm³ or at least 0.020 g/cm³.

Polymer materials can be reduced to suitable particle sizes by known techniques, such as shredding, milling, ordinary grinding, cryogenic grinding and wet grinding. Suitable equipment is commercially available. In addition, ground polymers are commercially available from recyclers, such as micronized polyurethane available from Mobius Technologies GmbH.

In some embodiments, the filler contains a mixture of polymer fillers and inorganic fillers. In some embodiments, the polymer fillers make up at least 5 volume percent of the filler or at least 10 volume percent or at least 20 volume percent or at least 40 volume percent or at least 60 volume percent or at least 80 volume percent or at least 90 volume percent. In some embodiments, the polymer filler makes up essentially 100 volume percent of the filler.

In some embodiments, the dry mix contains at least 40 volume percent filler, or at least 45 volume percent or at least 50 volume percent or at least 55 volume percent or at least 60 volume percent or at least 65 volume percent. In some embodiments, the dry mix contains at most 95 volume percent filler, or at most 90 volume percent or at most 85 volume percent or at most 80 volume percent. In many embodiments, the dry mix contains from 40 to 95 volume percent filler and from 5 to 60 volume percent cement, based solely on the volume of cement and filler.

Weight percentages of filler may vary greatly depending on the proportions of inorganic filler and polymer filler. Inorganic filler is much heavier than polymer filler, especially polymer filler made from foamed polymers such as ground PU/P1R polymers. In some embodiments, polymer filler makes up at least 1 weight percent of the dry mix or at least 2 weight percent or at least 3 weight percent or at least 4 weight percent or at least 5 weight percent or at least 6 weight percent. In some embodiments, polymer filler makes up at most 15 weight percent of the dry mix composition or at most 12 weight percent or at most 10 weight percent or at most 9 weight percent or at most 8 weight percent.

In addition to cement and filler, some embodiments of the dry mix may optionally contain other ingredients. An exemplary list of common additives for concrete and mortar includes the following:

• Pozzolans such as fly ash, calcined kaolin, pumices, or fumed silica. Pozzolans and their use in mortars and concrete are well-known and described in US Patent 9,181,131 B2

• Organic binders, such as a water-dispersible acrylic copolymer, vinyl ester copolymer or styrene -butadiene (SB) copolymer. Organic binders are frequently accompanied by a surfactant to help disperse them in the wet mix.

• Cellulose ethers, such as methyl cellulose, ethyl cellulose and methyl ethyl cellulose, can increase the water retention of the mortar and lengthen open time. Appropriate cellulose ethers are commercially available, such as under the WALOCEL™ trademark. • Starch ethers, such as hydroxypropyl starch ether, can improve the anti-sagging and anti-slip performance of the mortar, as well as lengthening open time and providing a smoother surface. Appropriate starch-ethers are commercially available, such as under the Aquaion trademark.

• Fibers can improve the tensile strength of the cured concrete or mortar. Examples of fibers include steel fibers, glass fibers, polymer fibers such as polypropylene or polyester, and natural fibers. In some embodiments, the fibers chopped short before they are added, such as to a length that provides an aspect ratio of 30 to 150. Suitable fibers are commercially available.

• Air-entraining agents cause the formation of small air-bubbles in the mortar, which can improve its resilience under freeze-thaw cycles. Air-entrainment agents are frequently surfactants. Suitable air-entrainment additives are commercially available.

• Accelerators speed the setting of the mortar. They may be especially useful in cold-weather application. Examples of common accelerants include calcium nitrate, calcium nitrite, calcium formate and certain aluminum compounds. Accelerator formulations with instructions for their use are commercially available.

• Retarders slow the setting time of the mortar. Examples of common retarders include calcium, sodium and ammonium salts of lignosulfonic acid, hydroxycarboxylic acids such as hydroxylic acid, carbohydrates, lead oxides, zinc oxides, phosphates, borates and fluorates. Retarder formulations with instructions for their use are commercially available.

• Defoamers can reduce air-entrainment and voids in the mortar. Examples of defoamers include mineral oils, polyglycols and polyethersiloxanes. Defoamers with instructions for their use are commercially available.

• Pigments color the concrete or mortar. Examples of pigments include titanium dioxide, carbon black, various iron oxides, chromium oxide and cobalt oxide. Pigments for concretes and mortars are commercially available.

In some embodiments, the dry mix contains at most 25 weight percent of the other ingredients or at most 20 weight percent or at most 15 weight percent or at most 10 weight percent or at most 5 weight percent or at most 2 weight percent, based on the dry ingredients in the composition and excluding water. In some embodiments, the dry mix contains no measurable content of the other ingredients (essentially 0 weight percent) or at least 1 weight percent or at least 2 weight percent, based on the weight of dry ingredients in the composition and excluding water.

The dry mix contains a granular wetting agent, in a quantity sufficient to wet the filler when the dry mix is mixed with water. The granular wetting agent in the dry mix contains at least 1 weight percent nonionic surfactant; in some embodiments it contains at least 3 weight percent nonionic surfactant or at least 5 weight percent or higher levels as previously described.

Optimal proportions of granular wetting agent may vary depending upon the selection of filler, the quantity of filler, the proportion of surfactant in the granular wetting agent and other factors. In some embodiments, the dry mix contains at least 0.5 weight percent granular wetting agent, or at least 1.0 weight percent or at least 1.5 weight percent or at least 2.0 weight percent. In some embodiments, the dry mix contains at most 20 weight percent granular wetting agent or at most 15 weight percent or at most 12 weight percent or at most 10 weight percent or at most 9 weight percent or at most 8 weight percent or at most 7 weight percent.

In some embodiments, the quantity of granular wetting agent is sufficient to deliver at least 0.01 weight percent surfactant to the dry mix or at least 0.03 weight percent or at least 0.05 weight percent or at least 0.1 weight percent or at least 0.2 weight percent or at least 0.3 weight percent or at least 0.4 weight percent. In some embodiments, the quantity of granular wetting agent is sufficient to deliver at most 5 weight percent surfactant to the dry mix or at most 3 weight percent or at most 2 weight percent or at most 1 weight percent or most 0.8 weight percent or most 0.7 weight percent or most 0.6 weight percent.

Wet Mix and Use

For use, the dry mix and other ingredients (if any) are mixed with water until homogeneous. The quantity of water is selected to thoroughly wet the dry mix and other ingredients (if any) and produce a homogenous composition with viscosity suitable for its intended use.

Workability wet mixes is commonly measured by the cone slump test, European Standard DIN EN 1015-3. In some embodiments, the wet mix has a slump of at least 0.5 inches (13 mm), or at least 1.0 inches (25 mm) or at least 1.5 inches (38 mm) or at least 2 inches (50 mm) or at least 3 inches (76 mm) or at least 4 inches (100 nini) or at least 5 inches (130 mm). In some embodiments, the wet mix has a slump of at most 8 inches (200 mm), or at most 7 inches (180 mm) or at most 6 inches (150 mm) or at most 5 inches (130 mm) or at most 4 inches (100 mm) or at most 3 inches (76 mm) or at most 2 inches (50 mm).

The density of the dry mix varies widely depending on the quantity of polymer filler used, and so the weight ratio of water to dry mix in a wet mix may also vary widely depending on the quantity of polymer filler used. When the filler contains only polymer fillers, in some embodiments the weight ratio of water to dry mix (and other solids if any) in the wet mix is at least 0.5 or at least 0.6 or at least 0.7 or at least 0.8 or at least 0.9; and in some embodiments the weight ratio of water to dry mix (and other solids if any) in the wet mix is at most 2 or at most 1.7 or at most 1.5 or at most 1.2 or at most 1.1.

Mixing can be accomplished by any known means, such as with a paddle, impeller or rotating drum.

Optionally other additives may be added before, during or after the mixing, such as additional fillers or concrete additives as previously described. Liquid additives are commonly added when the wet mix is made.

The composition of the wet mix reflects the components of the dry mix, the water added, and any other components added. Proportions are also the same.

The wet mix can be used as is ordinary for mortar or grout or concrete, and is allowed to dry and cure. For example, mortars may be applied between bricks, blocks or stones to hold them in place. Grouts may adhere tiles to a substrate and fill the spaces between tiles. Concretes may be poured into molds or cavities, and may optionally be smoothed. As with other wet mixes, in some cases, the wet mix of this invention may dry and cure enough to bear weight and be used in a period of 1-72 hours (depending on the contents of the wet mix and the conditions of curing), while full curing may take many days or weeks.

The product that results from curing of the wet mix, depends on the application that the wet mix was used in. A cured mortar of this invention may hold bricks, blocks or other structural elements in place. A cured grout may hold tile in place. A cured concrete may form solid structures, such as a pavement, pavers, floors, blocks, walls, pillars or other concrete article. Mortars and grouts of this invention, particularly using polymer fillers such as ground PU/PIR polymer foam, may have advantages over conventional concretes. They may be lighter and have improved thermal insulation.

Test Methods

Unless stated otherwise, measurements listed in this application are made using the following test methods:

Examples

The following examples illustrate specific embodiments of the invention, but do not limit the broadest scope of the invention. The materials in Table 1 are used for the Examples:

Table 1

Preparation of Granular Wetting Agent (GW A) (9% surfactant)

A 75g portion of the binder tritosolution is mixed with 25 g of the liquid wetting agent using a 4 pitch-blade. No gelling is observed. An 84g portion of the binder/surf actant solution is slowly added onto 200 g of the carrier using a batch high shear mixer equipped with rotating blades, until wet free- flowing agglomerates with a median particle size from 80 to 300 microns are formed. The wet agglomerates are dried using a laboratory fluidized bed (Strea-1 from Niro) for 20 minutes with an air temperature set at 60°C. The dry powder that is recovered is sieved. The fraction between 150 microns- 500 microns is kept, and contains 9 weight percent surfactant, based on the weight of the dry granular wetting agent.

Preparation of Granular Wetting Agent (GWA) (24% surfactant)

A 25g portion of the binder solution is mixed with 75 g of the liquid wetting agent using a 4 pitch-blade. No gelling is observed. An 80g portion of the binder/surfactant solution is slowly added onto 200 g of the carrier using a batch high shear mixer equipped with rotating blades, until wet free- flowing agglomerates with a median particle size from 80 to 300 microns are formed. The wet agglomerates are dried using a laboratory fluidized bed (Strea-1 from Niro) for 20 minutes with an air temperature set at 60°C. The dry powder that is recovered is sieved. The fraction between 150 microns- 500 microns is kept, and contains 24 weight percent surfactant, based on the weight of the dry granular wetting agent. Preparation and Testing of Concrete Formulations:

For experimental examples IE 1 to IE4, a dry mix is made by hand-mixing ordinary Portland cement, ground polyurethane filler, granular wetting agent made above, methyl cellulose and redispersible powder in the proportions shown in Table 2.

The dry mix is mixed with water in a Bluhm & Feuerherdt mortar mixer for 1 minute at speed 1 to make a wet mix. The quantity of water is tested to provide a wet mix that has a slump of 170 to 175 mm. The slump and amount of water needed to accomplish this slump are recorded in Table 2.

For comparative examples Cl, C2 and C5, a similar dry mix is made by the same procedures, except no granular wetting agent is added. Instead, a liquid wetting agent is added when the wet mix is made. Proportions of each component are shown in Table 2. A wet mix is made by the same procedure.

For comparative example C6, a similar dry mix is made by the same procedures, except no granular wetting agent is added. Proportions of each component are shown in Table 2. A wet mix is made by the same procedure.

For comparative example C4, a similar dry mix is made by the same procedures, except inorganic fillers arc used and no granular wetting agent is added. Proportions of each component arc shown in Table 2. A wet mix is made by the same procedure.

It is observed in testing that wet mixes made without wetting agent required more water to reach the same slump range. Water retention was also lower. The workability of samples that contained polymer filler was reduced because both water and filler separated over time.

The density of each wet mix is measured at intervals of 0, 5, 10, 15, 30 and 60 minutes. Table 2 shows the density after 0 minutes. It is observed that the samples containing polymer filler have lower density than the comparative example containing inorganic filler.

Each wet mix is poured into a mold for a test plaque and allowed to cure indoors at about 25°C for 7 days. The mold forms test plaques that are 40 cm long, 40 cm wide and 160 mm thick, Flexural and compressive strength of each test plaque is measured and shown in Table 2. It is observed that samples containing the granular wetting agents of the invention show improved flexural and compressive strength over the samples containing liquid wetting agent.

Claims

CLAIMS:

1. A granular wetting agent comprising the following components:

(a) An adsorbent inorganic powdered carrier;

2. The granular wetting agent of Claim 1 wherein the carrier comprises gypsum, calcium sulfate, silica or aluminosilicate.

3. The granular wetting agent of Claim 1 wherein the carrier comprises zeolite.

4. The granular wetting agent of Claim 1 wherein the binder has a melting temperature of at least 40°C.

5. The granular wetting agent of Claim 4 wherein the binder comprises polyacrylic acid polymer or polyvinyl alcohol polymer.

6. The granular wetting agent of Claim 4 wherein the binder comprises polyacrylic acid polymer.

7. The granular wetting agent of Claim 1 wherein the surfactant comprises fatty alcohol ethoxylate, alkyl phenol ethoxylate, fatty acid alkoxylate or fatty glucoside derivatives.

8. The granular wetting agent of Claim 1 wherein:

(a) The carrier makes up from 50 to 87 weight percent of the granular wetting agent;

(b) The binder makes up from 5 to 20 weight percent of the granular wetting agent; and

(c) The nonionic surfactant makes up from 8 to 30 weight percent of the granular wetting agent, wherein all weight percentages are based on the combined weight of components (a), (b) and (c).

9. The granular wetting agent of Claim 1 wherein:

(a) The carrier comprises a zeolite and makes up from 50 to 87 weight percent of the granular wetting agent;

(b) The binder comprises polyacrylic acid polymer that has a melting temperature of at least 50°C and makes up from 5 to 20 weight percent of the granular wetting agent; and

(c) The nonionic surfactant comprises fatty alcohol ethoxylate, alkyl phenol ethoxylate, fatty acid alkoxylate or fatty glucoside derivatives and makes up from 8 to 30 weight percent of the granular wetting agent, wherein all weight percentages are based on the combined weight of components (a), (b) and (c).

10. The granular wetting agent of Claim 1 wherein the binder adheres particles of carrier together to form agglomerated granules that have a median particle size from 150 micron to 500 micron.

11. The granular wetting agent of any one of Claims 1 to 10 wherein the granular wetting agent contains no more than 8 weight percent silicone anti-foam agent based on the combined weight of components (a), (b) and (c).

12. The granular wetting agent of Claim 11 wherein the granular wetting agent contains no more than 5 weight percent silicone anti-foam agent based on the combined weight of components (a), (b) and (c).

13. The granular wetting agent of Claim 11 wherein the granular wetting agent contains no more than 5 weight percent polysiloxane based on the combined weight of components (a), (b) and (c).

14. A dry mix comprising:

(a) A dry unhydrated particulate cement

(b) From 40 to 95 volume percent of a filler

(c) A granular wetting agent that contains: (i) An adsorbent inorganic powdered carrier;.

(ii) At least 1 weight percent of a nonionic surfactant adhered to the carrier; and in a quantity sufficient to enable wetting of the filler when the dry mix is mixed with water

15. The dry mix of Claim 14 wherein the filler comprises an organic polymer particles.