Classifications

• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
  • C04B41/60—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone of only artificial stone
  • C04B41/61—Coating or impregnation
  • C04B41/62—Coating or impregnation with organic materials
  • C04B41/63—Macromolecular compounds
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
  • C04B41/009—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone characterised by the material treated
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
  • C04B41/45—Coating or impregnating, e.g. injection in masonry, partial coating of green or fired ceramics, organic coating compositions for adhering together two concrete elements
  • C04B41/46—Coating or impregnating, e.g. injection in masonry, partial coating of green or fired ceramics, organic coating compositions for adhering together two concrete elements with organic materials
  • C04B41/48—Macromolecular compounds
  • C04B41/483—Polyacrylates
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D183/00—Coating compositions based on macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon, with or without sulfur, nitrogen, oxygen, or carbon only; Coating compositions based on derivatives of such polymers
  • C09D183/04—Polysiloxanes
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
  • C09D5/02—Emulsion paints including aerosols
  • C09D5/022—Emulsions, e.g. oil in water
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
  • C04B2111/20—Resistance against chemical, physical or biological attack
  • C04B2111/21—Efflorescence resistance

Definitions

• the present disclosure relates generally to coating compositions and more specifically to coating compositions for controlling efflorescence in porous construction materials.
• Efflorescence is a phenomenon describing the migration and precipitation of salts to the surface of porous construction materials, like concrete, where the salts form blotchy, powdery and/or crystalline deposits. Efflorescence occurs when absorbed moisture dissolves the salts in the porous construction material. The salts then migrate to the surface of the porous construction material. Once at the surface, the water evaporates leaving the salts as a white coating on the surface of the porous construction material.
• Acrylic based protection is based on the formation of a film at the surface of the porous construction material and leads to some surface appearance modification. Even if no pigments/filler are added in the acrylic, the surface of the porous construction materials will have a clear visual gloss. For some applications, there is a need to provide protection for porous construction which leave the appearance of the material un-modified (i.e., to have a“natural look”) and with no visual gloss.
• the present disclosure provides a coating composition for reducing absorption of water and at the same time for controlling efflorescence in porous construction materials that not only helps protect the porous construction materials from efflorescence, but also does not change the appearance of the porous construction material.
• the coating composition includes an acrylic polymer waterborne emulsion, where the acrylic polymer in the acrylic polymer waterborne emulsion has a Tg of 15 °C to 60 °C, and an oil-in- water silicon-based emulsion, where the oil phase of the oil-in-water silicon-based emulsion based provides the only coalescing agent for the acrylic polymer waterborne emulsion in the coating composition.
• the present disclosure further includes an aqueous composition for controlling efflorescence in porous construction materials, where the aqueous composition includes the coating composition and water sufficient to provide the aqueous composition with a solids content of 2 to 25 weight percent (wt.%) based on the total weight of the aqueous composition.
• the coating composition for use in controlling efflorescence in porous construction materials includes 25 wt.% to 95 wt.% of the acrylic polymer waterborne emulsion based on the total weigh of the coating composition, where the acrylic polymer in the acrylic polymer waterborne emulsion has a Tg of 15 °C to 60 °C; and 75 wt.% to 5 wt.% of the oil-in water silicon-based emulsion based on the total weigh of the coating composition.
• the oil-in water silicon-based emulsion includes an oil phase formed from compounds selected from the group consisting of an alkoxy silane, a silicone resin, poly dimethyl siloxane, polymethyl hydrogen siloxane and combinations thereof.
• the oil phase of the oil-in-water silicon-based emulsion based provides the only coalescing agent for the acrylic polymer waterborne emulsion in the coating composition.
• the coating composition of the present disclosure can have a variety of embodiments.
• coating composition for use in controlling efflorescence in porous construction materials can consist essentially of, or can consist of, 25 wt.% to 95 wt.% of the acrylic polymer waterborne emulsion based on the total weigh of the coating composition, where the acrylic polymer has a Tg of 15 °C to 60 °C; and 75 wt.% to 5 wt.% of the oil-in- water silicon-based emulsion based on the total weigh of the coating composition, where the oil-in-water silicon-based emulsion includes an oil phase formed from compounds selected from the group consisting of an alkoxy silane, a silicone resin, poly dimethyl siloxane, polymethyl hydrogen siloxane and combinations thereof, where the oil phase of the oil- in-water silicon-based emulsion based provides the only coalescing agent
• the acrylic polymer waterborne emulsion of the coating composition includes an acrylic polymer having a Tg of 25 °C to 55 °C.
• the acrylic polymer waterborne emulsion can have an acid level of up to 2 percent by weight of acid monomers based on a dry weight of the acrylic polymer.
• the acrylic polymer of the acrylic polymer waterborne emulsion can be formed with non-ionic monomers selected from the group consisting of methyl methacrylate, methyl acrylate, ethyl acrylate, butyl acrylate, styrene, butyl methacrylate, 2-ethylhexyl acrylate, t-butyl acrylate, a- methyl styrene, vinyl acetate, hexyl acrylate and combinations thereof.
• the acrylic polymer of the acrylic polymer waterborne emulsion is formed with non-ionic monomers selected from the group consisting of methyl methacrylate and butyl acrylate.
• the acrylic polymer of the acrylic polymer waterborne emulsion is formed with non-ionic monomers selected from the group consisting of methyl methacrylate and 2-ethylhexyl acrylate.
• non-ionic monomers selected from the group consisting of methyl methacrylate and 2-ethylhexyl acrylate.
• Other embodiments for the non-ionic monomers used to form the acrylic polymer of the acrylic polymer waterborne emulsion are also possible.
• the oil phase of the oil-in-water silicon-based emulsion can be formed from an alkoxy silane, where the alkoxy silane is selected from the group consisting of Si(OR)4, R'Si(OR)v (R 1 )2Si(OR)2 and combinations thereof, wherein each R 1 is
• the alkoxy silane is R 1 Si(OR)3.
• the R 1 has 8 carbon atoms and R has 2 carbon atoms to provide triethoxy(octyl)silane.
• the oil phase of the oil-in-water silicon-based emulsion can be formed from a silicone resin, where the silicone resin is formed from a hydrolysis- condensation reaction of any combination of compounds selected from the group consisting of Si(OR)4, R 1 Si(OR)3, (R 1 )2Si(OR)2 and combinations thereof, wherein each R 1 is independently selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, a substituted alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms or a substituted aryl group having 6 to 20 carbon atoms, and each R is independently an alkyl group having 1 to 6 carbon atoms.
• the oil phase of the oil-in-water silicon-based emulsion can be formed from a polymethyl hydrogen siloxane, where the polymethyl hydrogen siloxane is selected from compounds having the formulae: R 4 (R 5 ) 2 Si— (O— SiR3 ⁇ 4) a— (O— SiR 5 R 6 )b— Si (R 5 ) 2 R 4 (I); or (OSiR(R 5 )H) c (OSiR 5 R 6 )d (II) wherein; R 4 is hydrogen or an alkyl having 1 to 4 carbon atoms; R 5 is an alkyl having 1 to 4 carbon atoms; R 6 is an alkyl having 1 to 18 carbon atoms; a is an integer from 0 to 35; b is an integer from 0 to 32; and c and d are each
• the oil phase of the oil-in-water silicon-based emulsion can be formed from an organosiloxane, where the organosiloxane is selected from compounds having the formulae; (R 7 ) 3 Si— (O— Si(R 7 ) 2 ) a— (O— SiR 7 R 8 )b— SiR 7 3 (I); or HO(R 7 ) 2 Si— (O— Si(R 7 ) 2 ) a— (O— SiR 7 R 8 )b— Si(R 7 ) 2 OH (II) wherein; R 7 is an alkyl having 1 to 4 carbon atoms; R 8 is an alkyl having 1 to 18 carbon atoms; a is an integer from 0 to 35; b is an integer from 0 to 32; and c and d are each independently an integer from 1 to 10.
• Embodiments of the present disclosure also include an aqueous composition for use in controlling efflorescence in porous construction materials.
• the aqueous composition includes the coating composition, as described herein, and water in an amount sufficient to provide the aqueous composition with a solids content of 2 to 25 wt.% based on the total weight of the aqueous composition.
• the coating composition and the water of the aqueous composition add to 100 wt.% based on the total weight of the aqueous composition.
• aqueous composition of the present disclosure can be used with a porous
• porous construction material can include an inorganic porous construction material, where the inorganic porous construction material can be a cement based porous construction material.
• the present disclosure provides a coating composition for reducing absorption of water and at the same time controlling efflorescence in porous construction materials that not only helps protect the porous construction materials from efflorescence, but also do not change the appearance of the porous construction material.
• the coating composition includes an acrylic polymer waterborne emulsion, where the acrylic polymer in the acrylic polymer waterborne emulsion has a Tg of 15 °C to 60 °C, and an oil-in- water silicon-based emulsion, where the oil phase of the oil-in-water silicon-based emulsion provides the only coalescing agent for the acrylic polymer waterborne emulsion in the coating composition.
• the present disclosure further includes an aqueous composition for controlling efflorescence in porous construction materials, where the aqueous composition includes the coating composition and water sufficient to provide the aqueous composition with a solids content of 2 to 25 wt.% based on the total weight of the aqueous composition.
• the ingredients of the coating composition are described as being present as a weight percent, it is understood to mean that the weight of the coating composition is 100 percent and that all ingredients, including any optional additives, will sum up to 100 weight percent.
• a coating composition having 25 wt.% to 95 wt.% of the acrylic polymer waterborne emulsion based on the total weigh of the coating composition and 75 wt.% to 5 wt.% of the oil-in-water silicon-based emulsion based on the total weigh of the coating composition is understood to encompass a coating composition in which the amount of the acrylic polymer waterborne emulsion and oil-in-water silicon-based emulsion will sum up to 100 weight percent, or the amount of acrylic polymer waterborne emulsion, oil-in-water silicon-based emulsion and an optional additive or additives will sum up to 100 weight percent.
• the oil-in-water silicon- based emulsion can be any amount greater than 5 and up to 10 weight percent. In the instances when the oil-in- water silicon-based emulsion is less than 10 weight percent, optional additives in an amount sufficient to sum up to 100 weight percent are present in the coating composition.
• both the acrylic polymer waterborne emulsion and the oil-in-water silicon-based emulsion of the present disclosure are aqueous based continuous emulsions comprising a dispersed phase and a non-dispersed (continuous) phase in which the dispersed phase is either the acrylic polymer or silicon-based compounds and the non-dispersed phase is water or an aqueous solution or mixture.
• the coating composition of the present disclosure does not include another coalescing agent.
• coalescing agents are used to assist in the formation of films in film-forming compositions. Coalescing agents assist in film formation by, among other things, reducing the minimum film-forming temperature (MFFT) of polymer(s) dispersed in the composition. Reducing the MFFT of the polymer(s) helps them to better coalesce, where the coalescing agent functions as a temporary plasticizer for the polymer(s). So, coalescing agents help with film formation at temperatures that are below the MFFT of the polymer(s) present in the composition.
• MFFT film-forming temperature
• the use of the oil-in-water silicon-based emulsions as provided in the present disclosure have not been recognized nor used as a coalescing agent in coating compositions for use in controlling efflorescence in porous construction materials.
• the use of the oil-in-water silicon-based emulsions as provided in the present disclosure demonstrates low volatility and do not include volatile organic compounds (VOC), features which are both highly beneficial for the environment.
• the coating composition of the present disclosure does not include any additional coalescing agent(s) besides the oil-in-water silicon-based emulsions as provided in the present disclosure as they are not needed.
• the oil-in-water silicon-based emulsions includes an oil phase formed from compounds selected from the group consisting of an alkoxy silane, a silicone resin, poly dimethyl siloxane, polymethyl hydrogen siloxane and combinations thereof, where the oil phase of the oil-in-water silicon-based emulsion provides the only coalescing agent for the acrylic polymer waterborne emulsion in the coating composition.
• the oil-in water silicon-based emulsion refer to an emulsion having an aqueous based continuous phase with the oil phase dispersed therein.
• the oil phase is formed from the silicon-based compounds provided herein and the non-dispersed phase is water or an aqueous solution or mixture.
• the alkoxy silane is selected from the group consisting of Si(OR)4, R'Si(OR)v (R 1 )2Si(OR)2 and combinations thereof, wherein each R 1 is independently selected from an alkyl group having 1 to 20 carbon atoms, a substituted alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms or a substituted aryl group having 6 to 20 carbon atoms, and wherein each R is independently selected from an alkyl group having 1 to 6 carbon atoms.
• the alkoxy silane is R ⁇ ilOR ⁇
• the R 1 has 8 carbon atoms and R has 2 carbon atoms to provide
• triethoxy(octyl)silane triethoxy(octyl)silane.
• commercial alkoxy silanes useful for the oil-in-water silicon-based emulsion in the present disclosure include those sold under the tradenames DOWSILTM OFS 6341 and DOWSILTM OFS 6403.
• substituted as used in relation to another group, for example, an alkyl group, means, unless indicated otherwise, one or more hydrogen atoms in the alkyl group has been replaced with another substituent.
• substituents include, an alkyl group having 1 to 6 carbon atoms, halogen atoms such as chlorine, fluorine, bromine, and iodine; halogen atom containing groups such as chloromethyl, perfluorobutyl, trifluoroethyl, and
• oxygen atoms oxygen atom containing groups such as (meth)acrylic and carboxyl
• nitrogen atoms nitrogen atom containing groups such as amines, amino-functional groups, amido-functional groups, and cyano-functional groups
• sulphur atoms and sulphur atom containing groups such as mercapto groups.
• the silicone resin is formed from a hydrolysis-condensation reaction of any combination of compounds selected from the group consisting of Si(OR)4, R ⁇ SiiOR ⁇ , (R 1 )2Si(OR)2 and combinations thereof, wherein each R 1 is independently selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, a substituted alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms or a substituted aryl group having 6 to 20 carbon atoms, and each R is independently an alkyl group having 1 to 6 carbon atoms.
• the silicone resin may also contain reactive groups such as silanol groups (hydroxy bonded to a silicon atom) or alkoxy groups (OR groups bonded to a silicon atom).
• the amount of silanol groups present on the silicone resin may vary from 0.1 to 35 mole percent silanol groups, ], SiOR groups, alternatively from 2 to 30 mole percent alkoxy groups, alternatively from 5 to 20 mole percent alkoxy groups.
• the alkoxy groups may be present on any siloxy units within the silicone resin. The mole fractions of the various siloxy units and alkoxy content may be readily determined by 29 Si NMR techniques.
• the molecular weight of the silicone resin is not limited.
• the silicone resin may have a Mn (number average molecular weight) of at least 1,000 g/mole, alternatively M n of at least 2,000 g/mole, or alternatively M n of at least 5,000 g/mole.
• the number average molecular weight may be readily determined using Gel Permeation Chromatography (GPC) techniques.
• the polymethyl hydrogen siloxane is selected from compounds having the formulae: R 4 (R 5 )2Si— (O— SiR3 ⁇ 4) a— (O— SiR 5 R 6 )b— Si (R 5 )2R 4 (I); or (OSiR(R 5 )H) c (OSiR 5 R 6 )d (II) wherein; R 4 is hydrogen or an alkyl having 1 to 4 carbon atoms; R 5 is an alkyl having 1 to 4 carbon atoms; R 6 is an alkyl having 1 to 18 carbon atoms; a is an integer from 0 to 35; b is an integer from 0 to 32; and c and d are each independently an integer from 1 to 10.
• the organosiloxane is selected from compounds having the formulae; (R 7 ) 3 Si— (O— Si(R 7 ) 2 ) a— (O— SiR 7 R 8 )b— SiR 7 3 (I); or HO(R 7 ) 2 Si— (O— Si(R 7 ) 2 ) a—
• R 7 is an alkyl having 1 to 4 carbon atoms
• R 8 is an alkyl having 1 to 18 carbon atoms
• a is an integer from 0 to 35
• b is an integer from 0 to 32
• c and d are each independently an integer from 1 to 10.
• Representative, non-limiting examples of commercial polymethyl hydrogen siloxanes useful for the oil-in-water silicon-based emulsion in the present disclosure include those sold under the tradenames DOWSILTM 6-3570 Polymer, and Xiameter OFX-5625 fluid.
• the oil-in-water silicon-based emulsion of the present disclosure is formed from, more generally, a silane based emulsion, a silicone based emulsion or a mixture of both a silane and a silicone based emulsion.
• examples of silanes for the oil phase of the silane based emulsions can include the alkoxy silanes
• examples of the silicone based emulsion can include the silicone resin, the poly dimethyl siloxane and/or the polymethyl hydrogen siloxane provided herein.
• the coating composition of the present disclosure can include a combination of two or more of these compounds for the oil phase of the oil-in water silicon-based emulsion of the present disclosure.
• a ratio of silane based compounds to silicone based compounds in the oil phase of the oil-in-water silicon- based emulsion can range from 0: 1 to 1 :0 (silane: silicone). Ratios within this range are also possible, and include 0: 1, 0.01 :0.99, 0.05:0.95, 0.l :0.9, 0.2:0.8, 0.3:0.7, 0.4:0.6, 0.5:0.5, 0.6:0.4, 0.7:0.3, 0.8:0.2, 0.9:0. 1. 0.95:0.05, 0.99:0.01 and 1:0.
• Forming the oil-in-water silicon-based emulsion of the present disclosure can include forming a mixture by combining the desired ratio of the silane based compound(s) to silicone based compound(s), as provided herein, and mixing and homogenizing with water or an aqueous based solution to form the oil-in-water silicon-based emulsion of the present disclosure.
• Water as used herein, can include deionized water, whereas an aqueous based solution can include water and one or more hydrophilic additives.
• Such hydrophilic additives include, but are not limited to, low molecular weight alcohols such as methanol, ethanol, propanol, isopropanol and the like.
• One or more of a foam control agent and/or a pH control agent can be included with the oil-in-water silicon-based emulsion as desired.
• Oil-in-water silicon-based emulsion can be accomplished by known methods and may occur either as a batch, a semi-continuous, or a continuous process.
• Forming the oil-in-water silicon-based emulsion of the present disclosure can include adding from 30 to 900 parts of water or the aqueous based solution for every 100 parts of the silane based compound(s) and/or silicone based compound(s). This allows for the oil-in-water silicon- based emulsion to have an oil phase content of (e.g., a“solids” content) of 11% to 79% by volume.
• the average volume particle size of the oil phase content can be from 0.3 to 10 pm.
• the viscosity of the oil-in-water silicon-based emulsion of the present disclosure may be from 5 centipoises to 500 centipoises, as measured using a Brookfield viscometer; viscosities appropriate for different application methods vary considerably.
• the process of combining and mixing the components for the oil-in-water silicon-based emulsion may occur in a single step or multiple step process. Thus, the components may be combined in total, and subsequently mixed via any of the techniques described herein.
• a portion(s) of the components may first be combined, mixed, and followed by combining additional quantities of the components and further mixing.
• One skilled in the art would be able to select optimal portions of the components for combing and mixing, depending on the selection of the quantity used and the specific mixing techniques utilized in forming the oil-in-water silicon-based emulsion.
• the coating composition of the present disclosure also includes 25 wt.% to 95 wt.% of the acrylic polymer waterborne emulsion based on the total weigh of the coating composition.
• acrylic polymer waterborne emulsion refers to a water based emulsion, where the acrylic polymer of the acrylic polymer waterborne emulsion is formed with non-ionic monomers selected from the group consisting of methyl methacrylate, methyl acrylate, ethyl acrylate, butyl acrylate, styrene, butyl methacrylate, 2-ethylhexyl acrylate, t-butyl acrylate, a-methyl styrene, vinyl acetate, hexyl acrylate and combinations thereof.
• the use of the term "meth” followed by another term such as methacrylate refers to both acrylates and methacrylates.
• the acrylic polymer of the acrylic polymer waterborne emulsion is formed with non-ionic monomers selected from the group consisting of methyl methacrylate and butyl acrylate.
• the acrylic polymer of the acrylic polymer waterborne emulsion is formed with non-ionic monomers selected from the group consisting of methyl methacrylate and 2-ethylhexyl acrylate.
• the acrylic polymer is substantially uncross-linked, that is the acrylic polymer includes less than 1 weight %, preferably less than 0.2 weight %, based on the weight of the polymer, and more preferably 0% of a copolymerized multi-ethylenically unsaturated monomer.
• Multi- ethylenically unsaturated monomers include, for example, allyl (meth)acrylate, diallyl phthalate, 1, 4-butylene glycol di(meth)acrylate, 1, 2-ethylene glycol di(meth)acrylate, 1 ,6-hexanediol di(meth)acrylate, and divinyl benzene.
• the acrylic polymer waterborne emulsion has an acid level of up to 2 percent by weight of acid monomers based on a dry weight of the acrylic polymer.
• Acid monomers include carboxylic acid monomers such as, for example, acrylic acid, methacrylic acid, crotonic acid, itaconic acid, fumaric acid, maleic acid, monomethyl itaconate, monomethyl fumarate, monobutyl fumarate, and maleic anhydride; and sulfur- and phosphorous-containing acid monomers.
• Preferred acid monomers are carboxylic acid monomers. More preferred monomers are (meth)acrylic acid.
• the acid level can be calculated by determining the number of milliequivalents of acid per gram in the acrylic polymer and multiplying by the molecular weight of potassium hydroxide.
• the glass transition temperature (“Tg") of the acrylic polymer can be from 15 °C to 60 °C.
• the acrylic polymer in the acrylic polymer waterborne emulsion has a Tg of 25 °C to 55 °C.
• the Tg of the acrylic polymer can be calculated by using the Fox equation (T. G. Fox, Bull. Am. Physics Soc., Volume 1, Issue No. 3, page 123 (1956)), where calculating the Tg of a copolymer of monomers Ml and M2 is determined using the equation:
• Tg(calc) is the glass transition temperature calculated for the copolymer
• w(Ml) is the weight fraction of monomer Ml in the copolymer
• w(M2) is the weight fraction of monomer M2 in the copolymer
• Tg(Ml) is the glass transition temperature of the homopolymer of Ml
• Tg(M2) is the glass transition temperature of the homopolymer of M2, all temperatures being in degree Kelvin.
• the glass transition temperature of homopolymers may be found, for example, in "Polymer Handbook", edited by J. Brandrup and E. H. Immergut, Interscience Publishers. In calculating Tgs herein the contribution of copolymerized graftlinking monomers is excluded.
• the calculated Tg is calculated from the total overall composition of the acrylic polymer particle.
• the polymerization techniques used to prepare the acrylic polymer of the acrylic polymer waterborne emulsion include emulsion polymerization, which is well known in the art (e.g., examples disclosed in U.S. Pat. Nos. 4,325,856; 4,654,397; and 4,814,373 among others).
• surfactants such as, for example, anionic and/or nonionic emulsifiers such as, for example, alkali metal or ammonium alkyl sulfates, alkyl sulfonic acids, fatty acids, and oxy ethylated alkyl phenols.
• the amount of surfactant used can be from 0.1% to 6% by weight, based on the weight of total monomer. Either thermal or redox initiation processes may be used.
• free radical initiators such as, for example, hydrogen peroxide, t-butyl hydroperoxide, t-amyl hydroperoxide, ammonium and/or alkali persulfates, typically at a level of 0.01% to 3.0% by weight, based on the weight of total monomer.
• Redox systems using the same initiators coupled with a suitable reductant such as, for example, sodium sulfoxylate formaldehyde, sodium hydrosulfite, isoascorbic acid, hydroxylamine sulfate and sodium bisulfite may be used at similar levels, optionally in combination with metal ions such as, for example iron and copper, optionally further including complexing agents for the metal.
• the monomer mixture for a stage may be added neat or as an emulsion in water.
• the monomer mixture for a stage may be added in a single addition or more additions or continuously over the reaction period allotted for that stage using a uniform or varying composition; preferred is the addition of the polymer monomer(s) emulsion as a single addition.
• Additional ingredients such as, for example, free radical initiators, oxidants, reducing agents, chain transfer agents, neutralizers, surfactants, and dispersants may be added prior to, during, or subsequent to any of the stages.
• the average particle diameter of the acrylic polymer particles can be from 40 to 400 nanometers (measured with a Brookhaven Instruments particle size analyzer).
• the solids content of the acrylic polymer waterborne emulsion of the present disclosure may be from 30% to 70% by weight based on the total weight of the acrylic polymer waterborne emulsion.
• the viscosity of the acrylic polymer waterborne emulsion of the present disclosure may be from 10 centipoises to 5000 centipoises, as measured using a Brookfield viscometer; viscosities appropriate for different application methods vary considerably.
• the acrylic polymer waterborne emulsion of the present disclosure can have a pH of 3 to 11 as measured at 23 °C.
• the coating composition can be prepared by techniques that are well known in the coatings art.
• the acrylic polymer waterborne emulsion and the oil-in-water silicon-based emulsion can be added under low shear stirring along with other coatings adjuvants as desired.
• the coating composition may contain, in addition to the acrylic polymer waterborne emulsion and the oil-in-water silicon-based emulsion, inorganic fillers such as quartz, biocides when water is present, untreated and treated silicas, metal hydroxide micropowders such as aluminum hydroxide micropowder, calcium hydroxide micropowder, and magnesium hydroxide micropowder, bisamides, flake-form fillers such as mica, dimethylpolysiloxanes, epoxy functional diorganopolysiloxanes, and amino-functional diorganopolysiloxanes, as well as pigments, curing agents, buffers, corrosion inhibitors, neutralizers, humectants, wetting agents, antifoaming agents, UV absorbers, fluorescent brighteners, light or heat stabilizers, biocides, dispersants, colorants, colorant dispersions, waxes, water-repellants, pigments, extenders, anti oxidants and dyes can be added to the coating composition. Additional
• the present disclosure also provides for an aqueous composition for use in controlling efflorescence in porous construction materials.
• the aqueous composition includes the coating composition as described herein and water in an amount sufficient to provide the aqueous composition with a solids content of 2 to 25 wt.% based on the total weight of the aqueous composition.
• the coating composition as described herein can be considered to be a concentrate form of the aqueous composition, where the coating composition is diluted with water or an aqueous composition to arrive at the aqueous composition.
• an embodiment of the present disclosure includes where the coating composition and the water of the aqueous composition add to 100 wt.% based on the total weight of the aqueous composition.
• aqueous composition with a solids content of 2 to 25 wt.% based on the total weight of the aqueous composition can be accomplished by known methods and may occur either as a batch, a semi-continuous, or a continuous process.
• Forming the aqueous composition of the present disclosure can include water or an aqueous composition to the coating composition, as provided herein, to arrive at the solids content of 2 to 25 wt.% based on the total weight of the aqueous composition.
• arriving at the solids content for the aqueous composition will depend on the solids content of each of the acrylic polymer waterborne emulsion and the oil-in-water silicon-based emulsion.
• the process of combining and mixing the acrylic polymer waterborne emulsion and the oil-in-water silicon-based emulsion may occur in a single step or multiple step process.
• the components may be combined in total, and subsequently mixed via any of the techniques described herein.
• a portion(s) of the components may first be combined, mixed, and followed by combining additional quantities of the components and further mixing.
• One skilled in the art would be able to select optimal portions of the components for combing and mixing, depending on the selection of the quantity used and the specific mixing techniques utilized in forming the aqueous composition.
• aqueous composition can be used for controlling efflorescence in porous construction materials.
• the aqueous composition of the present disclosure can be used with a porous construction material.
• the aqueous composition of the present disclosure can be used to at least partially coat the porous
• porous construction material can include an inorganic porous construction material, where the inorganic porous construction material can be a cement based porous construction material.
• the aqueous composition of the present disclosure is applied to the porous construction material and, dried, or allowed to dry.
• the aqueous composition is typically applied to a porous construction material such as, for example, wood and/or inorganic porous substrates such as those made with cement or gypsum.
• a porous construction material such as, for example, wood and/or inorganic porous substrates such as those made with cement or gypsum.
• inorganic porous substrates include concrete, stucco, dry wall, and mortar that are either new and not previously painted or treated, previously printed, painted or primed surfaces, or weathered surfaces.
• the aqueous composition of the present disclosure may be applied to the porous construction material using conventional coatings application methods such as, for example, paint brush, paint roller, gravure roll, curtain coater and spraying methods such as, for example, air-atomized spray, air-assisted spray, airless spray, high volume low pressure spray, and air-assisted airless spray. Drying of the aqueous composition may proceed under ambient conditions such as, for example, at 5 °C to 35 °C or the coating may be dried at elevated temperatures such as, for example, from 35 °C to 100 °C.
• conventional coatings application methods such as, for example, paint brush, paint roller, gravure roll, curtain coater and spraying methods such as, for example, air-atomized spray, air-assisted spray, airless spray, high volume low pressure spray, and air-assisted airless spray. Drying of the aqueous composition may proceed under ambient conditions such as, for example, at 5 °C to 35 °C or the coating may be dried at elevated temperatures such as,
• FC board used in the examples were prepared using the Hatscheck process and were air cured.
• the FC board has a thickness of 0.8 cm.
• the FC board was stored at room temperature (23 °C) at a relative humidity of 40 to 50%. Perform the following coating tests at room temperature (23 °C) at a relative humidity of 40 to 50%.
• Comparative Example dilute each of the oil-in-water silicon-based emulsion and the acrylic polymer waterborne emulsion of the coating composition seen in Tables 2 and 4 with deionized water to achieve the aqueous composition, where the aqueous composition has a solids content of 15 weight percent (wt.%) based on the total weight of the aqueous composition.
• FC board Place a FC board on top of a refrigerated cold pack having a temperature of -18 °C to form an assembly. Place the assembly in a weather chamber in which the relative humidity is set > 80% . The cold surface leads to forced condensation of cold water at the surface of the FC boards. Replace the cold pack every day. FC boards are left for a week (7 days) in the weather chamber. Efflorescence is visually assessed after drying the FC boards.
• Table 3 shows a dramatic decrease in absorption of water by treating FC boards with pure silane/siloxane formulation (CE A) or aqueous compositions formed with the coating compositions of the present disclosure (Ex 1-3), provided the acrylic polymer content is not larger than 75% by weight based on the total weight of the coating composition (e.g., Ex 4).
• Table 3 also demonstrates that some whitening of the surface of the FC boards occurs as a result of the lack of Resistance to Efflorescence Test described above.
• Table 4 provides an additional Example (Ex 6) and Comparative Examples (CE E - CE H) of the coating composition.
• Each of CE E through CE H further includes 8 wt.% (based on the total weight of the polymer content in the acrylic polymer waterborne emulsion) of the coalescing agent.
• Use deionized water to prepare aqueous compositions having a solids content of 10% using coating compositions from each of Ex 6 and CE E-H seen in Table 4.
• Ex 6 shows that FC boards treated with an aqueous composition containing only the acrylic polymer waterborne emulsion with the acrylic polymer having a Tg of greater than 15 °C and the oil-in-water silicon-based emulsion of the present disclosure having no additional coalescing agent shows no sign of efflorescence.

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• 2019
  • 2019-09-23 CA CA3112956A patent/CA3112956A1/en active Pending
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