Water-based acrylic texture layer forming composition for a topcoat of a synthetic sports surface

Abstract

The invention provides a two-component aqueous texture layer forming composition useful for forming a flexible finish layer of a sports surface. The composition comprises vulcanized or crosslinked rubber particles, for example EPDM rubber, a soft acrylic emulsion copolymer:hard acrylic emulsion copolymer blend having a solids weight ratio of vulcanized or crosslinked rubber particles solids in the range of less than 1:4 to 1:9, a polyalkylene oxide rheology modifier, one or more high boiling alcohols, and as separate components a water dispersion of an aliphatic polyisocyanate and an epoxy silane. The vulcanized or crosslinked rubber particles can have a sieve particle size of 8 mm or less. The finish layer of the invention has enhanced tensile strength and elongation as well as improved shelf life and color stability.

Description

Technical Field

[0001] This invention relates to aqueous acrylic textured layer forming compositions that can be used to form textured topcoat layers on moving surfaces. More specifically, this invention relates to two-component aqueous acrylic compositions comprising, as one component, an acrylic emulsion polymer blend of a soft emulsion polymer and a hard emulsion polymer, rubber particles, a polyoxyalkylene rheology modifier, and a high-boiling-point alcohol, and as another component, a water-dispersible polyisocyanate. The invention also relates to methods for preparing multilayer moving surfaces using these compositions, and multilayer moving surfaces prepared by these methods. Background Technology

[0002] Synthetic sports surfaces are widely used as running tracks, school sports surfaces, tennis courts, and playgrounds. Sports surfaces can comprise layers of rubber granules bonded together by thermosetting polymers such as polyurethane (PU). These sports surfaces can be formed on top of a durable cement, concrete, rammed stone, or asphalt substrate in multiple layers (e.g., two or three): a primer layer that improves adhesion to the cement, concrete, rammed stone, or asphalt substrate; a base layer or buffer layer comprising an elastomeric composite material, such as an aromatic polyurethane matrix containing an aromatic polyurethane prepolymer with dispersed rubber granules; and a topcoat layer that provides friction and additional cushioning, as well as weather resistance and durability, such as, for example, ultraviolet (UV) stability and color retention. These layers of the sports surface can be applied to the substrate using conventional pavers, screeners, or troweling equipment (such as by hand).

[0003] The same equipment can be used to form all the layers, making application easier. For example, PU compositions can be used to form the individual layers as adhesives. However, using PU compositions as a topcoat layer for moving surfaces has several disadvantages. Aromatic isocyanates are not UV stable and can cause color changes over time. Aliphatic isocyanates do not have this disadvantage. However, they are less reactive and result in lower physical properties.

[0004] WIPO Publication No. WO 2017 / 185332A1, granted to Dow Global Technologies LLC, discloses an acrylic multilayer system for sports flooring, comprising a composition for forming an acrylic topcoat layer, preferably sprayed. However, the physical properties (such as elongation and tensile strength) of the topcoat layer formed from the acrylic composition can be improved. In addition, conventional thickeners are used to increase the viscosity of the acrylic coating composition to prevent it from separating from the rubber particles. However, the resulting water-based coating composition does not adhere properly to the rubber particles under shear and during mixing and application.

[0005] The inventors have worked to solve the problem of providing an aqueous composition for preparing textured topcoat layers for moving surfaces, which provides improved mechanical properties in UV-stable, weather-resistant topcoat layers. Summary of the Invention

[0006] According to the present invention, the two-component aqueous textured layer forming composition comprises:

[0007] The first component comprises (i) an acrylic emulsion copolymer blend of (a) a first acrylic emulsion copolymer A and (b) a second acrylic emulsion copolymer B in a solid weight ratio of copolymer A to copolymer B of 25:75 to 90:10 or preferably 30:70 to 80:20, wherein the first acrylic emulsion copolymer A has a calculated glass transition temperature (calculated Tg) of -60°C to -5°C and the second acrylic emulsion copolymer B has a calculated Tg of 15°C to 60°C; and (ii) vulcanized or crosslinked rubber particles, preferably ethylene propylene diene monomer (EPDM) rubber or reclaimed rubber, wherein the ratio of the acrylic emulsion copolymer blend to the vulcanized or crosslinked rubber particles is [missing information]. The solid weight ratio is in the range of less than 1:4 to 1:9 or preferably 1:4.5 to 1:8; (iii) one or more polyoxyalkylene rheology modifiers having a viscosity-average molecular weight of 400,000 to 5,000,000 or preferably 480,000 to 2,500,000, such as polyethylene oxide having a viscosity-average molecular weight of 400,000 to 5,000,000 or preferably 480,000 to 2,500,000; and (iv) one or more high-boiling alcohols having a standard boiling point of 170°C to 315°C or preferably 180°C to 300°C and further having a molecular weight of 100 to 250 (such as 130 to 250) of the formula MW; and

[0008] The second component (v) comprises a crosslinking agent containing both a water-dispersible polyisocyanate composition and an epoxy silane, preferably wherein the polyisocyanate is an aliphatic water-dispersible polyisocyanate. The solid weight ratio of the water-dispersible isocyanate composition to the epoxy silane can be in the range of 0.4:1 to 5:1 or preferably 0.6:1 to 2.5:1. Based on the total weight of the acrylic emulsion copolymer blend, (iii) a suitable amount of one or more polyoxyalkylene rheology modifiers can be in the range of 0.1 wt.% to 0.5 wt.% or preferably 0.1 wt.% to 0.4 wt.% based on the total weight of the acrylic emulsion copolymer blend, (iv) a suitable amount of one or more high-boiling alcohols can be in the range of 0.5 wt.% to 10 wt.% or preferably 0.5 wt.% to 7 wt.% based on the total weight of the acrylic emulsion copolymer blend. The amount of crosslinking agent can be in the range of 1 wt.% to 10 wt.%, or 1 wt.% to 8 wt.%, or preferably 2 wt.% to 6 wt.%, based on the total solid weight of the acrylic emulsion copolymer blend.

[0009] The (i) acrylic emulsion copolymer blend of the aqueous texture layer forming composition according to the invention may comprise a copolymer of one or more acrylate monomers in copolymer form with one or more C1-C8 alkyl esters of (meth)acrylate (preferably methyl methacrylate) in copolymer form as a first acrylic emulsion copolymer A, wherein the one or more acrylate monomers are selected from methyl acrylate, ethyl acrylate, butyl acrylate, ethylhexyl acrylate, ethylhexyl methacrylate, aliphatic alkyl (meth)acrylates, or mixtures thereof. Based on the total weight of the monomers used to prepare the copolymer, the first acrylic emulsion copolymer A may also contain, in copolymer form, up to 5 wt.% or preferably 0.1 wt.% to 2 wt.% of a monomer or salt thereof containing an olefinically unsaturated carboxylic acid group, such as acrylic acid or methacrylic acid, or a monomer or salt thereof containing a carboxylic amide group (such as (meth)acrylamide) or preferably a monomer or salt thereof containing an olefinically unsaturated carboxylic acid group. In the acrylic emulsion copolymer blend according to (i) of the present invention, the second acrylic emulsion copolymer B may comprise one or more C1-C8 alkyl methacrylates (preferably methyl methacrylate) in copolymer form or one or more C5-C acrylates. 12The second acrylic emulsion copolymer B may also contain copolymers of alkyl esters or cycloalkyl acrylates (such as isobornyl acrylate or cyclohexyl acrylate) with one or more other acrylic or vinyl monomers (such as those selected from alkyl (meth)acrylates, (meth)acrylonitrile, allyl-containing monomers, aryl groups, or mixtures thereof) in copolymer form. Based on the total weight of the monomers used to prepare the copolymer, the second acrylic emulsion copolymer B may also contain up to 5 wt.% or preferably 0.1 wt.% to 2 wt.% of a monomer or salt thereof containing an olefinically unsaturated carboxylic acid group in copolymer form, such as acrylic acid or methacrylic acid or a monomer or salt thereof containing a carboxylic amide group (such as (meth)acrylamide), preferably a monomer or salt thereof containing an olefinically unsaturated carboxylic acid group. Based on the total weight of the monomers used to prepare the copolymer, the first acrylic emulsion copolymer A or the second acrylic emulsion copolymer B may also contain up to 3 wt.% or preferably 0.05 wt.% to 2 wt.% of one or more tackifying monomers (such as urea-containing (meth)acrylates) in copolymer form.

[0010] Vulcanized or cross-linked rubber particles may have a sieve size of 0.7 mm to 8 mm or preferably 0.85 mm to 5 mm.

[0011] In the composition for forming an aqueous textured layer, (iv) one or more high-boiling alcohols may be selected from hydroxyl-containing esters of C3-C8 alkyl esters, such as isobutyrates containing hydroxyl groups; alkyl fatty acid esters containing hydroxyl groups; alkyl ethers containing hydroxyl groups; C6-C 12 Branched alkanols; and aliphatic ethers containing hydroxyl groups, preferably, at least one of the aliphatic ethers containing hydroxyl groups is an isobutyrate containing hydroxyl groups.

[0012] The first component of the composition for forming an aqueous textured layer may also contain fillers, preferably fillers containing hydroxyl or hydrolyzable groups in an aqueous medium, such as silicates or alumina.

[0013] In another aspect of the invention, a method of using the aqueous texture layer forming composition of the first aspect of the invention includes applying the two-component aqueous texture layer forming composition to a substrate, such as by using a paver, a sieving device, or a trowel to form a topcoat layer as a topcoat layer. The method may further include drying the topcoat layer. The substrate may be selected from any of the following: cement, concrete, compacted stone or asphalt substrate (substrate), a primer substrate containing a substrate having a primer layer thereon, a buffer layer having a composite containing vulcanized or cross-linked rubber particles or an elastomer layer thereon, or a primer substrate having both a buffer layer and a primer layer thereon. The method may include mixing the two components of the aqueous texture layer forming composition of the invention before or during application. The aqueous texture layer forming composition used in the method of the invention may contain the composition described in any one of paragraphs

[0006] ,

[0007] ,

[0008] ,

[0009] , or

[0010] above.

[0014] In yet another aspect of the invention, the multilayer moving surface comprises a cement, concrete, rammed stone, or asphalt substrate (base), on which a buffer layer comprising a composite comprising vulcanized or cross-linked rubber particles or an elastomer layer is provided, further comprising a primer layer on the buffer layer, and even further comprising a weather-resistant textured topcoat layer comprising a matrix comprising a polyurethane (polyurethane) cross-linked acrylic copolymer blend, the polyurethane (polyurethane) cross-linked acrylic copolymer blend comprising (a) a first acrylic copolymer A having a calculated glass transition temperature (calculated Tg) of -60°C to -5°C and (b) a second acrylic copolymer B having a calculated Tg of 15°C to 60°C in a solid weight ratio of copolymer A to copolymer B of 25:75 to 75:25 or preferably 30:70 to 70:30; the matrix having a certain amount of vulcanized or cross-linked rubber The granules, preferably ethylene propylene diene monomer (EPDM) rubber or reclaimed rubber, wherein the solid weight ratio of the acrylic copolymer blend to the vulcanized or crosslinked rubber granules is in the range of less than 1:4 to 1:9 or preferably 1:4.5 to 1:8; wherein, further, the matrix comprises each of one or more polyoxyalkylene rheology modifiers and one or more high-boiling alcohols, wherein the one or more polyoxyalkylene rheology modifiers have a viscosity-average molecular weight of 400,000 to 5,000,000 or preferably 480,000 to 2,500,000, such as polyoxyethylene oxide having a viscosity-average molecular weight of 400,000 to 5,000,000; and the one or more high-boiling alcohols have a standard boiling point of 170°C to 315°C or preferably 180°C to 300°C and have a molecular weight of 100 to 250 (such as 130 to 250). The crosslinked acrylic copolymer blend comprises a crosslinked aliphatic polyurethane and silane-containing groups. Preferably, one or more high-boiling-point alcohols in the textured topcoat layer can be selected from hydroxyl-containing esters of C3-C8 alkyl esters, such as hydroxyl-containing isobutyrates; hydroxyl-containing fatty acid alkyl esters; hydroxyl-containing alkyl ethers; C6-C 12 Branched alkanols; and aliphatic ethers containing hydroxyl groups. Detailed Implementation

[0015] According to the present invention, an aqueous composition comprising vulcanized or crosslinked rubber particles enables the formation of a weather-resistant topcoat layer. In the aqueous composition, a blend of soft acrylic emulsion copolymers and hard acrylic emulsion copolymers, along with a high-boiling-point alcohol and a polyoxyalkylene rheology modifier, allows for a higher proportion of vulcanized or crosslinked rubber particles to be provided in use. This, in turn, provides a topcoat layer with enhanced color and ultraviolet (UV) stability, tensile strength, and elongation at break. The aqueous composition has two components, whereby the acrylic emulsion copolymer blend is crosslinked with polyisocyanates and epoxy silanes in the aqueous texture layer forming composition. The present invention avoids the problem that adding a compatible thickener (such as polyethylene oxide (PEO)) to the aqueous composition would require increasing the water load in the composition by 50 wt.% or more shear levels. Using lower alkanols to introduce thickeners into the composition, the low boiling point of which would result in unsuitable high VOC levels. The inclusion of high-boiling-point, high-molecular-weight alcohols (such as 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate (boiling point: 255°C)) in the composition avoids an increase in VOC levels. Simultaneously, the high-boiling-point alcohols act as coalescing agents, making the copolymer matrix in the topcoat layer more flexible, thereby improving the function of the track or playground topcoat layer, for example, at cooler temperatures. Despite the high content of rubber particle solids in the aqueous texture layer forming composition of the present invention, the composition still exhibits a good shelf life after the two components are mixed together. Furthermore, even if the buffer layer composition contains aromatic polyisocyanates, the aqueous texture layer forming composition can be mixed in the same equipment used to form the buffer layer without adversely affecting the shelf life of the aqueous texture layer forming composition.

[0016] Unless otherwise indicated, all temperature and pressure units are room temperature (21°C to 23°C) and standard pressure (1 atm). In addition, unless otherwise specified, all conditions include a relative humidity (RH) of 45% to 55%.

[0017] Unless the context clearly indicates otherwise, the singular forms “a”, “an”, and “the” include plural indicators.

[0018] Unless otherwise indicated, the technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art.

[0019] All ranges are inclusive and composable. Thus, for example, a disclosure that includes ranges less than 1:4 to 1:9 or preferably 1:4.5 to 1:8 will be understood to include ranges less than 1:4 to 1:9, or less than 1:4 to 1:8, or 1:4.5 to 1:9, or less than 1:4 to 1:4.5 or preferably 1:4.5 to 1:8.

[0020] All phrases containing parentheses indicate either or both of the substances enclosed in the parentheses and their absence. For example, in an alternative, a phrase including "(meth)acrylate" includes both acrylates and methacrylates.

[0021] As used herein, the term "acrylic monomer" refers to any of (meth)acrylic acid, (meth)acrylate alkyl esters, (meth)acrylamide, (meth)acrylonitrile, and their functionalized forms (e.g., (meth)acrylate hydroxyalkyl esters).

[0022] As used herein, the term "aqueous" includes water and mixtures consisting essentially of water and water-miscible solvents, where "consisting essentially of" means that only the listed materials are included or added to the solvent composition. Some impurities or other trace materials (e.g., less than 0.5 wt.%) may still be present in the composition which substantially contains or lists the materials.

[0023] Unless otherwise stated, as used herein, the terms “sieve size” or “PS” refer to the average particle size determined by sieving, wherein the reported particle size is the sieve aperture size or linear resolution (in mm or micrometers) of the smallest sieve aperture through which the entire composition will pass, excluding impurities.

[0024] As used herein, unless otherwise stated, the terms “calculated Tg” or “calculated glass transition temperature” refer to the Tg of a polymer calculated using the Fox equation (TGFox, Bulletin of the American Physical Society, Vol. 1, No. 3, p. 123 (1956)). For reference and use in calculating Tg, a comprehensive compilation of available data describing the glass transition temperatures of homopolymers of suitable monomers can be found in the Polymer Handbook, Vol. 1, edited by Brandrup, J., Immergut, EH, and Grulke, EA, 1999, pp. 193-277.

[0025] Unless otherwise specified, as used herein, the phrase “application conditions” refers to standard pressure and ambient outdoor temperature or room temperature (21°C to 23°C). Application conditions include all temperatures and pressures at which the two-component aqueous composition is mixed or applied to any substrate.

[0026] As used herein, the phrase “based on the total weight of monomers used to form the emulsion polymer” refers to all addition monomers, such as carboxylic acid-functional vinyl or olefinically unsaturated monomers, and chain transfer agents that leave residues in the polymer, such as hypophosphite or their salts.

[0027] As used herein, the term “copolymer” in alternative contexts refers to a polymer prepared from one or more different monomers, such as copolymers, terpolymers, quaternary copolymers, pentpolymers, etc., and can be any of random polymers, block polymers, graft polymers, sequence polymers, or gradient polymers.

[0028] As used herein, the term “formula MW” refers to the atomic or molar mass of a mole of a molecule having an idealized or representative structure, regardless of its distribution or the molecular weight of an isomer mixture.

[0029] As used in this article, the term "ISO" refers to the publications of the International Organization for Standardization (Geneva, CH) in Geneva, Switzerland.

[0030] As used herein, unless otherwise stated, the term "standard boiling point" refers to the boiling point of a liquid or fluid at 760 mm / Hg.

[0031] As used herein, the term "substantially free of" any given material, composition, or ingredient (such as formaldehyde, volatile amines, alkylphenyl ethoxylates, or solution polymers) means any composition, article comprising them, and method of preparation or use thereof, wherein the reference composition, article, or method does not contain such added material or ingredient. The amount of a given material, composition, or ingredient will be less than 5000 ppm, or preferably less than 1000 ppm, based on the total weight of the composition said to be substantially free of it.

[0032] As used herein, the phrase “total solids” or “solids weight” or its equivalents refer to the weight of all non-volatile components or materials in a given composition relative to the total weight of a reference material or composition that may include volatiles. Volatile components include water and ammonia, as well as volatile solvents that evaporate at standard pressure and at 40°C or lower.

[0033] As used herein, unless otherwise stated, the term “viscosity-average molecular weight” or “MWv” refers to the molecular weight of a composition determined by comparing the viscosity of the composition with the viscosity of a set of calibrated appropriate reference standards (such as polyethylene oxide for polyoxyethylene rheology modifiers) having known molecular weights and viscosities, wherein the viscosities of the reference standards are measured in the same manner, using the same indicated solids, the same carriers or solvents, and under the same temperature, shear, and measurement conditions as the viscosity of the analyte.

[0034] As used in this article, the term "wt.%" means weight percentage.

[0035] The first component of the aqueous textured layer forming composition according to the present invention comprises a blend of acrylic emulsion copolymers A and B. The acrylic emulsion copolymer blend is a blend of soft acrylic emulsion copolymer A and hard acrylic emulsion copolymer B. The acrylic emulsion copolymer according to the present invention comprises a polymerization product of an olefinically unsaturated monomer (such as a vinyl or acrylic monomer) capable of addition polymerization. Preferably, the aqueous textured layer forming composition is substantially free of alkylphenyl ethoxylates (APEO). More preferably, the aqueous textured layer forming composition is substantially free of volatile organic compounds and alkylphenyl ethoxylates (APEO).

[0036] Acrylic emulsion copolymers that can be used in compositions for forming waterborne textured layers may comprise, in copolymer form, various combinations of one or more acrylate monomers, one or more monomers containing olefinically unsaturated carboxylic acid groups or their salts (such as acrylic acid or methacrylic acid), one or more monomers containing carboxylic amide groups or their salts (such as (meth)acrylamide), and one or more additional acrylic monomers or vinyl monomers. The combination of monomers can be selected in a manner known to those skilled in the art in the provision of mixtures and proportions of acrylic emulsion copolymers having a calculated Tg as described in the present invention.

[0037] Suitable vinyl or acrylic monomers for preparing the acrylic emulsion copolymers of the present invention may include: olefinically unsaturated monomers, such as (meth)acrylate monomers (e.g., C1-C18 alkyl methacrylates), such as methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, nonyl acrylate, decyl acrylate, lauryl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, nonyl methacrylate, isodecyl methacrylate, lauryl methacrylate; (meth)acrylate hydroxyalkyl esters, such as hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, and hydroxypropyl methacrylate; diene-bonded unsaturated monomers, such as 1,3-butanediol dimethacrylate; (meth)acrylamide; alkyl allyl ethers; allyl alcohol; (meth)acrylonitrile; styrene or alkyl-substituted styrene; or mixtures thereof.

[0038] The suitable acrylic emulsion copolymer B is PRIMAL. TM AC-261K adhesive (The Dow Chemical Co., Midland, MI); an example of a suitable acrylic emulsion copolymer A could be Elastene. TM 2848 NG adhesive or PRIMAL TM EC-2949 APEO Free Adhesive (Dow).

[0039] Suitable aqueous emulsion polymerization techniques for preparing acrylic emulsion copolymer blends according to the present invention are well known in the art. Thermal initiation, redox initiation, photochemical initiation, and electrochemical initiation methods can be used, wherein the aqueous polymerization medium comprises one or more initiators and one or more surfactants or emulsifiers. The copolymer can be prepared as an aqueous mixture with a solids content of 20 wt.% to 70 wt.%, preferably in the range of 30 wt.% to 60 wt.%.

[0040] Suitable free radical initiators or oxidants may include, for example, persulfates, such as ammonium persulfate and / or alkali metal persulfates; peroxides, such as sodium or potassium hydroperoxide, tertiary alkyl peroxides, tertiary alkyl hydroperoxides, dicumyl hydroperoxides; perboronic acids and their salts, such as sodium perborate; and ammonium or alkali metal salts of peroxydisulfuric acid. The amount of such initiators may range from 0.05 wt.% to 3.0 wt.% based on the total weight of the monomers used to prepare the copolymer. Suitable redox catalysts can be the same radical initiators coupled with suitable reducing agents (such as, for example, (iso)ascorbic acid, sodium formaldehyde sulfoxylate, sodium sulfite, or alkali metal (heavy) bisulfite); thiosulfates, bisulfites; (hydro)sulfides or dithionites; formamidine sulfinic acid; hydroxymethanesulfonic acid; sodium 2-hydroxy-2-sulfinylacetate; and acetone bisulfite; and the amount of such salts can be from 0.01 wt.% to 5.0 wt%, based on the total weight of the monomers used to prepare the copolymer.

[0041] Conventional surfactants or emulsifiers can be used in polymerization reactions, including: anionic emulsifiers such as bases or ammonium alkyl sulfates and oxyethylated alkylphenol sulfates; nonionic emulsifiers such as polyoxyethyleneized alkyl alcohols, amine polyethylene glycol condensates, and alkyl polyether alcohols; or combinations thereof. Based on the total weight of the monomers used to prepare the copolymer, the typical range of surfactants is 0.05 wt.% to 10 wt.%, or preferably 0.05 wt.% to 5 wt.%.

[0042] Chain transfer agents can be used to control the molecular weight of copolymers. Examples of suitable chain transfer agents include thiols, polythiols, and polyhalogen compounds, including alkyl thiols (such as n-dodecyl thiols), used in amounts ranging from 0 wt.% to 6 wt.% or 0.1 wt.% to 3 wt.% based on the weight of the olefinically unsaturated monomers in the monomer mixture used to prepare the copolymer. Thiols are preferred. The polymer molecular weight can be controlled by other techniques known in the art, such as selecting the ratio of initiator to olefinically unsaturated monomers.

[0043] In the acrylic emulsion copolymer blends according to the invention, copolymers A and B can have a weight-average particle size of 100 nm to 500 nm, or preferably 200 nm to 400 nm. The diameter of the copolymer particles can be controlled in one or more of several ways known in the art. To increase the weight-average particle size, the amount of conventional surfactants or emulsifiers added during emulsion polymerization can be reduced, or the shear rate during polymerization can be reduced, or the content of metal ions or salts present during and after polymerization can be increased, or any combination thereof. Preferably, pre-prepared polymer seeds with a sufficiently small weight-average particle size (e.g., 25 nm to 60 nm) can also be used to allow the copolymer to grow to the desired average particle size.

[0044] The first component of the aqueous textured layer forming composition of the present invention further comprises (ii) vulcanized or cross-linked rubber particles. Examples of suitable vulcanized or cross-linked rubber particles for use in the present invention include styrene-butadiene rubber (SBR), ethylene-propylene-diene monomer (EPDM) rubber, ethylene-propylene rubber, cis-butadiene rubber, natural rubber, styrene-butadiene copolymer, hydrogenated nitrile rubber, nitrile rubber, chloroprene rubber, polychloroprene, or recycled rubber (such as ground tire rubber (GTR) or waste rubber or mixtures thereof). Waste rubber can be from any known source, such as, for example, tires, shoe soles, and ground tire rubber. The vulcanized or cross-linked rubber for use in the present invention can have a sieve particle size of 0.5 mm or larger, 0.7 mm or larger, or even 0.85 mm or larger, and simultaneously 8 mm or smaller or even 5 mm or smaller.

[0045] The vulcanized or cross-linked rubber particles may preferably be selected from ethylene propylene diene monomer (EPDM) rubber, polyurethane rubber, styrene-butadiene rubber, natural rubber, acrylonitrile or acrylonitrile butadiene styrene rubber (ABN) or recycled rubber (such as the solid weight ratio of ground tire rubber (GTR) to rubber particles in the total solids of an acrylic emulsion copolymer being less than 1:4 to 1:9 or preferably 1:4.5 to 1:8).

[0046] To adjust rheological properties, the first component of the aqueous textured layer forming composition according to the invention comprises (iii) one or more polyoxyalkylene oxides, or preferably polyethylene oxides, with a viscosity-average molecular weight of at least 500,000. Rheology modifiers have been found to provide some internal adhesion and wet adhesion / tackiness to crosslinked or vulcanized rubber particles. In addition, the aqueous textured layer forming composition comprises one or more (iv) high-boiling-point alcohols. High-boiling-point alcohols can help disperse the rheology modifiers in the absence of any volatile organic compounds.

[0047] One or more (iv) high-boiling alcohols in the aqueous texture layer forming composition may be selected from hydroxyl-containing alkyl esters, alkyl oxide esters, and branched alkyl esters of C3-C8 alkyl esters, such as, for example, isobutyrates (e.g., 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate or 2,2,4-trimethyl-1,3-pentanediol diisobutyrate); hydroxyl-containing (branched) alkyl esters, alkyl aryl esters, or alkoxyalkyl esters, glycerides, amides, or alkoxylates of fatty acids; or hydroxyl-containing (branched) alkyl ethers, alkyl aryl ethers, or alkoxyalkyl ethers and alkoxylates of fatty alcohols. A suitable amount of one or more high-boiling alcohols may be in the range of 1 wt.% to 10 wt.% based on the total weight of the acrylic emulsion copolymer blend of the aqueous texture layer forming composition.

[0048] The aqueous textured layer forming composition according to the invention may further include one or more defoamers in the first component. Suitable defoamers may be silicone-containing defoamers, mineral oil-containing defoamers, ethylene oxide or propylene oxide-containing defoamers, or mixtures thereof. Suitable commercially available defoamers may include, for example, NOPCO. TM NXZ Metal Soap, TEGO TM Airex902 W and TEGO TM Foamex 1488 polyether silicone copolymer emulsion (Tego, Evonik Industries, Essen, DE) of Evonik Industries, Germany, BYK-024 silicone defoamer (BYK, BYK-Chemie GmbH, Wesel, DE) of BYK-Chemie GmbH, Wesel, Germany, or mixtures thereof. Suitable amounts of the defoamer may be in the range of 0.01 wt.% to 1 wt.%, 0.05 wt.% to 0.8 wt.%, or 0.1 wt.% to 0.3 wt.%, based on the total weight of the first component of the composition for forming the aqueous textured layer.

[0049] The first component of the aqueous textured layer forming composition according to the invention preferably further comprises a lubricant, such as a fatty acid metal salt (e.g., calcium stearate). Based on the total weight of the first component of the aqueous textured layer forming composition, a suitable amount of lubricant, in solids, may be 0.05 wt.% to 1 wt.%, 0.1 wt.% to 0.8 wt.%, or 0.1 wt.% to 0.5 wt.%.

[0050] The first component of the aqueous texture layer forming composition according to the invention preferably further comprises a filler, or more preferably a filler comprising hydrolyzable groups or hydroxyl-containing groups, such as silicates (e.g., sodium-potassium alumina silicates (nepheline syenite)) or alumina. Such fillers form hydroxyl or hydrolyzable groups in water. Based on the total weight of the first component of the aqueous texture layer forming composition, a suitable amount of filler, in solids, can range from 0 wt.% to 50 wt.% or from 1 wt.% to 40 wt.%.

[0051] The first component of the composition for forming an aqueous textured layer may also contain any one or a combination of the following additives: inorganic extenders, pigments, fillers, buffers, neutralizers, dispersants, humectants, fungicides, biocides, antiskinning agents, colorants, flow agents, antioxidants, plasticizers, leveling agents, dispersants, tackifiers, diluents, and abrasives.

[0052] Based on the total weight of the first component of the composition for forming an aqueous textured layer, the amount of any additive may be from 0.001 wt.% to 10 wt.% or from 0.01 wt.% to 2 wt.%.

[0053] As a second component, the aqueous textured layer forming composition of the present invention comprises (v) one or more aqueous polyisocyanate dispersions as crosslinking agents and epoxy silanes. Such aqueous polyisocyanate dispersions can be prepared from polyisocyanates by reacting the polyisocyanate with at least partially the following: at least one reactant containing an anionic group, at least one polyethylene oxide, both the reactant containing an anionic group and polyethylene oxide, a tertiary amine (such as triethylamine) or an amino alcohol (such as triethanolamine) (preferably anionic). After neutralization, the polyurethane can be dispersed in water under stirring to produce a dispersion. As used herein, the term "anionic group" refers to a chemical group that carries a negative charge when mixed with water. The anionic group can be combined with one or more cations, which can be metal cations or organic compounds having cationic groups. Preferred anionic groups may be selected from sulfonate groups, carboxylate groups, carboxylate groups (such as in dimethylpropionic acid), phosphonate groups, or mixtures thereof.

[0054] Suitable polyisocyanates are any compounds containing isocyanate functional groups having two or more isocyanate groups. Polyisocyanates can be prepolymers prepared by reacting an excess of one or more organic polyisocyanates with one or more organic compounds (especially polyols) containing two or more isocyanate reactive groups. The reaction can be carried out in the presence of catalysts such as organotin compounds and / or tertiary amines.

[0055] Polyisocyanates are well known in the art and include aliphatic, alicyclic, and / or aromatic isocyanates containing at least two isocyanate groups per molecule. Suitable aliphatic diisocyanates may include, for example, hexamethylene diisocyanate and propylene diisocyanate. Suitable alicyclic diisocyanates include, for example, isophorone diisocyanate and hydrogenated products of aromatic diisocyanates, such as methylene diphenyl isocyanate (MDI). Suitable aromatic diisocyanates include, for example, toluene diisocyanate and methylene diphenyl diisocyanate and other diisocyanates known in the art, as well as isomers or mixtures thereof. Suitable triisocyanates may include, for example, biuret (such as biuret of hexamethylene diisocyanate and water), isocyanurates (such as isocyanurates of hexamethylene diisocyanate), and addition products of isophorone diisocyanate and trimethylolpropane. Other suitable aliphatic polyisocyanates include 1,6-hexamethylene diisocyanate (HDI), 1-isocyano-3-isocyanomethyl-3,5,5-trimethyl-cyclohexane (IPDI), 4,4′-diisocyanate dicyclohexylmethane (HMDI), diisocyanomethyl-cyclohexane (ADI), their isomers, their polymers, or mixtures thereof. Other suitable aromatic polyisocyanates are toluene-2,4-diisocyanate (2,4-TDI), toluene-2,6-diisocyanate (2,6-TDI), naphthylene-1,5-diisocyanate, diphenylmethane-4,4′-diisocyanate (MDI), their isomers, their polymers, and mixtures thereof.

[0056] Suitable commercially available water-dispersible isocyanate compositions include, for example, BAYHYDUR prepared from hexamethylene diisocyanate. TM XP2655 is a hydrophilic aliphatic polyisocyanate, or BAYHYDUR prepared from hexamethylene diisocyanate. TM ULTRA 2487 / 1 hydrophilic aliphatic polyisocyanate (Covestro, Pittsburgh, PA).

[0057] Based on the total solids weight of the acrylic emulsion copolymer blend, the concentration of the polyisocyanate crosslinking agent in the aqueous textured layer forming composition of the present invention can be in the range of 1 wt.% or more, 2 wt.% or more, and simultaneously in the range of 10 wt.% or less, 8 wt.% or less, or 5 wt.% or less. Preferably, based on the total solids weight of the acrylic emulsion copolymer blend, the concentration of the polyisocyanate composition is in the range of 2 wt.% to 8 wt.%.

[0058] The second component of the aqueous textured layer forming composition according to the invention preferably further comprises an epoxy silane, such as epoxypropoxypropyltrialkoxysilane. Based on the total weight of the components of the aqueous textured layer forming composition, a suitable amount of epoxy silane, in solids, can be from 0.5 wt.% to 8 wt.% or from 1 wt.% to 7 wt.%. The weight ratio of the water-dispersible isocyanate composition to the epoxy silane can be 0.4:1 or greater, 0.6:1 or greater, or even 1.5:1 or greater; and simultaneously within the range of 10:1 or less, 5:1 or less, or even 2.5:1 or less.

[0059] Suitable commercially available epoxy silanes include, for example, SILQUEST, available from Momentive Performance Materials. TM A-187, SILQUEST TM WetLink 78, SILQUEST TM A-186 and COATOSIL TM 2287 epoxy silane, or OFS 6040 silane (Dow Corning, Midland, MI).

[0060] In another aspect of the invention, a method is provided comprising applying a two-component aqueous textured layer forming composition to a substrate to form a textured topcoat layer. The application may include known troweling, spreading, or grading equipment. The same application equipment may be used for any or all layers, whether the substrate is a primer layer, a buffer layer, or a cement or asphalt substrate, or any layer of a multilayer moving surface according to the invention. The method may further include curing the textured topcoat layer. Furthermore, the method may include mixing the two components of the aqueous textured layer forming composition just before or during application, which may include mixing within the application equipment itself.

[0061] In the method according to the invention, any aqueous composition can be applied to the substrate by any known method, such as manual troweling or using conventional runway paving equipment (such as PlanoMatic). TM P928 automatic paver type synthetic runway paver or PlanoMatic TM P211 Semi-Automatic Paver (Germany) SMG Sportplatzmaschinenbau GmbH, The surface is applied by a machine. The resulting surface can be further smoothed by polishing. The substrate can be any material, such as concrete, asphalt, metal, or wood. Before applying the water-based texture layer forming composition, the substrate or buffer layer can be primed with a polyurethane-containing primer composition (such as a polyurethane primer). When preparing a multi-layered moving surface, the drying and curing of any water-based composition can be carried out at a predetermined temperature and for a predetermined period of time sufficient to evaporate the water. Drying and curing can be carried out at ambient temperature.

[0062] The aqueous textured layer forming composition of the present invention can generally be cured at temperatures ranging from 5°C to 80°C, or from 10°C to 50°C, or from 15°C to 40°C, or from 20°C to 35°C. The curing time of the polymer mixture can range from 30 minutes to 8 hours, 1 hour to 48 hours, or 2 hours to 10 hours. Higher temperatures accelerate curing. It is also possible to partially cure the polymer mixture and then complete the curing process at a later time.

[0063] In preparing the multilayer moving surface according to the invention, the time interval between the application of any composition (such as a first layer of a composition for forming a buffer layer, a composition for forming a primer layer, or a composition for forming a water-based texture layer) and the application of the layer of water-based composition or its second layer can be, for example, 8 hours or less, 6 hours or less, or even 5 hours or less, and simultaneously within the range of 2 hours or more, 2.5 hours or more, or even 3 hours or more.

[0064] In yet another aspect, the present invention provides a multilayer moving surface comprising a substrate having a buffer layer thereon, a primer layer thereon, and a weather-resistant textured topcoat layer thereon. The buffer layer comprises a composite or elastomer layer of vulcanized or crosslinked rubber particles, for example, a crosslinked composite dispersion of vulcanized or crosslinked rubber particles dispersed in a matrix of polyurethane, elastomeric acrylic polymer, or mixtures or combinations thereof. The elastomeric acrylic may be formed from the same acrylic emulsion copolymer blend used to form the textured topcoat layer or composition, or from an acrylic emulsion copolymer comprising a diene-bonded unsaturated monomer in copolymer form (such as divinylbenzene and having a calculated Tg of -60°C to 5°C). The polyurethane may be formed from the reaction product of a polyisocyanate and a polyol (such as a polyether polyol) of the textured topcoat layer, wherein the polyisocyanate is preferably an aromatic polyisocyanate. The primer layer comprises a composition for forming a polymer matrix and an epoxy silane or epoxy resin, such as γ-glycidoxypropyltrialkoxysilane; the polymer matrix of the primer layer may be formed from a composition (such as an acrylic emulsion copolymer blend of a textured topcoat composition, or an acrylic emulsion copolymer having a calculated Tg of -60°C to 5°C, as in a buffer layer). Based on the total solid weight of the composition for forming the polymer matrix, the amount of epoxy resin or silane in the composition for forming the primer layer may range from 0.1 wt.% to 5 wt.%. In the buffer layer of the multilayer moving surface of the present invention, the weight ratio of acrylic emulsion copolymer and / or polyurethane solids to vulcanized or crosslinked rubber particles may be 1:6.5 or lower or even 1:7 or lower, and simultaneously 1:11 or higher or even 1:10 or higher. The vulcanized or crosslinked rubber particles in the base layer may have a sieve particle size of 0.7 mm to 8 mm, preferably 0.85 mm to 5 mm, more preferably 1 mm to 5 mm. The vulcanized or cross-linked rubber particles in the base layer preferably comprise recycled rubber or styrene-butadiene rubber.

[0065] The primer layer of the multilayer moving surface of the present invention can be used to further improve the adhesion of the multilayer article to a substrate or other layered substrate. The primer layer can be made of a primer composition comprising a first acrylic emulsion copolymer A, a second acrylic emulsion copolymer B, a mixture thereof as a blend of acrylic emulsion copolymers, or another acrylic emulsion copolymer. The primer composition may also contain an epoxy silane to further improve the adhesion of the resulting multilayer article to the substrate under humid conditions. The primer composition may also contain an isocyanate prepolymer composition, such as an isocyanate prepolymer composition for an aqueous texture layer forming composition. Preferably, the primer composition comprises a first acrylic emulsion copolymer A and a second acrylic emulsion copolymer B as a blend, an epoxy silane, and a water-dispersible polyisocyanate composition. When the above materials are used in an aqueous texture layer forming composition, their amounts in the primer composition can be within the ranges described above. The multilayer article of the present invention may also include other functional layers. For example, the multilayer article may also include a protective layer such that a top layer is located between the protective layer and the substrate layer. The presence of this protective layer can be used to further improve the abrasion resistance and aging resistance of the multilayer article.

[0066] The multi-layer sports surface and water-based textured layer composition according to the present invention can be used for:, for example, sound insulation materials, sound insulation pads, floor pads and mats; industrial or sports facilities (such as artificial running tracks and playground surfaces, ball cores) and consumer products (such as floor tiles and coverings); molded products; and road paving and maintenance applications. In particular, the multi-layer sports surface can be used for running tracks, tennis courts or rubber playground surfaces.

[0067] Example

[0068] The following examples illustrate the invention. Unless otherwise stated, all parts and percentages are by weight, and all temperatures are in °C. In the examples below and in Tables 1, 2, and 3, the following abbreviations are used: AA: acrylic acid; AN: acrylonitrile; DVB: divinylbenzene; MAA: methacrylic acid; S: styrene; MMA: methyl methacrylate; BA: butyl acrylate; SHP: sodium hypophosphite; UEMA: ureoethyl functionalized methacrylate; BP: benzophenone. Table 1 below shows the materials used.

[0069] In the following examples, the tested formulations are shown in Tables 2A and 2B below. In all formulations, the high-boiling-point alcohol and polyoxyalkylene rheology modifier were premixed by hand with a spatula, and each of the individual components was premixed with the first component, and milled at 600 rpm to disperse the rubber particles and any fillers. Prior to use, the materials were mixed to form an aqueous composition, which was applied and used according to the test methods described below.

[0070] The following test methods are used in the following embodiments.

[0071] Tensile strength and elongation when compressing dog bone-shaped specimens: The formulation shown, containing rubber granules, was mixed and spread onto a mold with a PTFE release liner, with a 1cm steel gasket secured with tape to form a sheet with an area of ​​18cm × 30cm. The formulation was pressed into the frame with a spatula to obtain a textured topcoat layer with a thickness of 1cm. To obtain a more uniform layer, silicone release paper and then a 3kg fiber-reinforced cement board were placed on top of the layer to press it for 30 minutes. The layer was cured for 7 days at 23°C and 50% RH before testing and cut to produce 15 samples with a dog-bone shape (ISO 527-2 Typ 1A) cut mold. Ten samples were tested at room temperature (RT), and five samples were tested after immersion in water for 1 day. Tensile and elongation measurements were performed using a Zwick Roell Allround-Line 2.5 kN tester (Zwick GmbH & Co. KG, Ulm, DE, Germany). The tensile speed was set to 100 mm / min; a clamp clearance of 110 mm was used. The maximum tensile strength and elongation at break were recorded. The results are shown in Table 3 below.

[0072] Rectangular specimens for tensile strength and elongation: Except for the absence of release paper and fiber cement pressing, the prepared formulation as described above was cured into a 1 cm thick sheet and cut into rectangular shapes of 3.5 cm × 10 cm. Tensile tests were then performed using a ZwickRoell Z005 mechanical testing machine (Zwick Ltd.). The clamp gap was 50 mm, and the tensile speed was set to 50 mm / min. The maximum tensile strength was recorded. The recorded elongation values ​​are the elongation at break values. The results are shown in Table 3 below.

[0073] Color stability The two components of the indicated formulation were mixed together and then mixed with the indicated rubber particles for 2 minutes. The resulting composition was then placed in a Piper petri dish to form a layer and aged in an ultraviolet (UV) chamber with a xenon lamp for 48 hours. After aging, the yellowing of each layer was visually observed.

[0074] Table 1: Materials Used

[0075]

[0076]

[0077] Table 2A: High-boiling-point alcohol preparations

[0078]

[0079] * indicates a comparative example; 1. The EPDM particle size range is 1mm-3mm; 2. It contains 2.39g of secondary alcohol polyoxyethylene ether (98%) surfactant.

[0080] Table 2B: Filler formulations or proportions of various polymers

[0081]

[0082] * indicates a comparative example; 1. Portaflame TM SG-10 filler for the synthesis of aluminum hydroxide (D50: 3.5 microns, Sibelco (Antwerp, BE), Belgium); 2. Minex TM 4. Nepheline syenite (Silbiko); 3. Orotan TM 2500 dispersant S-AA copolymer 24.8 wt.%, 25% ammonia (6.7 wt.%) and DI water (68.5 wt.%) (Dow); 4. Wash and sieve the rubber granules in water before use; 5. EPDM particle size range is 1 mm-3 mm; 6. Methylene diphenyl isocyanate (MDI) (47 wt.% of the 2,4′ isomer).

[0083] Table 3: Tensile and Elongation Results

[0084] Test methods 7-day RT tensile (MPa) - rectangular specimen 0.637 1.084 1.139 0.981 1.053 7-day RT fracture elongation % - rectangular specimen 34.97 67.77 71.73 95.23 109.17

[0085] * indicates a comparative example.

[0086] As shown in Table 3 above, the compositions of the present invention containing high-boiling-point alcohols in Examples 2, 3, 4 and 5 exhibit significantly improved room-temperature tensile strength and elongation at break compared to the same aqueous composition containing ethanol in Comparative Example 1.

[0087] Table 4: Tensile and Elongation Results

[0088]

[0089] * indicates a comparative example.

[0090] As shown in Table 4 above, the compositions of the present invention in Examples 6, 7, 8, 9, and 10 all exhibited the same level of improved wet tensile and elongation and dry tensile and elongation in dog bone-shaped specimens as the compositions in Examples 2, 3, 4, and 5. All compositions of the present invention are aqueous, substantially VOC-free, substantially APEO-free, and contain high-boiling-point alcohols.

[0091] The composition of Example 6 of the present invention Color stabilityTest results showed only slight yellowing after 48 hours of ultraviolet (UV) aging, while the same composition, based on the total solids weight of the acrylic emulsion copolymer blend, showed significant yellowing after 48 hours of UV aging, even at lower concentrations of aromatic diisocyanates instead of aliphatic polyisocyanates. Color stability tests indicated that the aqueous texture-forming composition of the present invention, with an aliphatic crosslinking agent, provides a more UV-stable product compared to the same aqueous texture-forming composition using aromatic diisocyanates as crosslinking agents.

[0092] Storage period test and results Using aromatic crosslinking agent 3, three compositions substantially the same as those in Comparative Example 1 were formed without rubber particles and stretched into layers. The compositions contained 2.5 wt.%, 5 wt.%, and 10 wt.%, respectively, of the crosslinking agent. The compositions containing 5 wt.% and 10 wt.% of the aromatic crosslinking agent exhibited almost complete curing of the film on the layer after one hour, while the compositions containing 2.5 wt.% of the aromatic crosslinking agent remained film-free after 1 and 3 hours. This indicates that compositions such as those of the present invention, which can achieve a higher proportion of rubber particles while maintaining an operable viscosity, will also have a longer shelf life than known compositions. A lower amount of crosslinking agent relative to the total weight of the composition for forming the aqueous textured layer also contributes to a longer shelf life.

Claims

1. A two-component aqueous textured layer forming composition, said two-component aqueous textured layer forming composition comprising: The first component comprises (i) an acrylic emulsion copolymer blend of (a) a first acrylic emulsion copolymer A and (b) a second acrylic emulsion copolymer B, wherein the solid weight ratio of copolymer A to copolymer B is 25:75 to 90:10, the first acrylic emulsion copolymer A having a calculated glass transition temperature of -60°C to -5°C, and the second acrylic emulsion copolymer B having a calculated glass transition temperature of 15°C to 60°C; and (ii) vulcanized or crosslinked rubber particles, wherein the acrylic emulsion copolymer blend comprises: The solid weight ratio of the vulcanized or crosslinked rubber particles is less than 1:4 and greater than or equal to 1:9; (iii) one or more polyoxyalkylene rheology modifiers having a viscosity-average molecular weight of 400,000 to 5,000,000; and (iv) one or more high-boiling alcohols having a standard boiling point of 170°C to 315°C and a molar mass of 100 to 250, wherein the one or more high-boiling alcohols are selected from hydroxyl-containing esters of C3-C8 alkyl esters, hydroxyl-containing alkyl esters of fatty acids, hydroxyl-containing alkyl ethers, and C6-C6 alkyl esters. 12 Branched alkanols; and aliphatic ethers containing hydroxyl groups; and The second component (v) comprises a crosslinking agent containing both an aliphatic water-dispersible polyisocyanate composition and an epoxy silane.

2. The composition for forming an aqueous textured layer according to claim 1, wherein the (ii) vulcanized or crosslinked rubber particles comprise ethylene propylene diene monomer EPDM rubber or recycled rubber.

3. The composition for forming an aqueous textured layer according to claim 1, wherein... The solid weight ratio of the acrylic emulsion copolymer blend to the vulcanized or cross-linked rubber particles is in the range of 1:4.5 to 1:

8.

4. The composition for forming an aqueous textured layer according to claim 1, wherein... The one or more polyoxyalkylene rheology modifiers mentioned in (iii) are polyoxyethylene.

5. The composition for forming an aqueous textured layer according to claim 1, wherein one or more high-boiling alcohols (iv) are selected from 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate and dipropylene glycol n-butyl ether.

6. The composition for forming an aqueous textured layer according to claim 1, wherein at least one of the (iv) one or more high-boiling alcohols is an isobutyrate containing a hydroxyl group.

7. The composition for forming an aqueous textured layer according to claim 1, wherein... Based on the total weight of the acrylic emulsion copolymer blend, the amount of (iv) one or more high-boiling alcohols is in the range of 0.5 wt.% to 10 wt.%.

8. The composition for forming an aqueous textured layer according to claim 1, wherein... The composition also includes fillers.

9. The composition for forming an aqueous textured layer according to claim 8, wherein the filler comprises hydroxyl groups or hydrolyzable groups in an aqueous medium.

10. A method of using the aqueous texture layer forming composition according to claim 1, the method comprising applying the two-component aqueous texture layer forming composition onto a substrate to form a layer as a topcoat layer.

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