Artificial turf containing washable adhesive composition

Abstract

The present disclosure provides an artificial turf. In one embodiment, the artificial turf includes a primary backing layer having a plurality of artificial turf yarns extending upwardly therefrom. The artificial turf also includes a secondary backing layer in contact with the primary backing layer. The secondary backing layer is made of an acrylic adhesive. The acrylic adhesive comprises (i) an acrylic polymer consisting of polymerized units of (a) a first monomer which is a C4-C18 alkyl acrylate, and (b) a second monomer selected from the group consisting of acrylic acid, methacrylic acid, and optionally a C1-C3 alkyl acrylate containing a hydroxyl group. The acrylic adhesive further comprises (ii) at least one inorganic neutralizing agent, and (iii) at least one surfactant.

Description

Background Art

[0001] In recent years, there has been a surge in interest in artificial turf. Artificial turf (also known as "synthetic grass") is increasingly being used to replace natural grass on playing surfaces, particularly on sports pitches and playgrounds. Artificial turf is also suitable for use in landscaping and leisure settings.

[0002] Current turf structures contain different materials, i.e. turf yarn, primary backing layer and secondary backing layer, which results in the difficulty of recyclability of asphalt. The secondary backing layer is typically a coated layer that provides the "tuft-lock" of the turf yarn in the primary backing layer, which is an important parameter for asphalt durability. The conventional coated layer composition used as the secondary backing layer is made of latex (several types of latex exist natural rubber (NR), SIS (styrene-isoprene rubber), SBR (styrene-butadiene rubber) etc.). SBR is the most common type of synthetic latex used in the production of artificial turf; however, a combination of two rubber layers as SBR / NR and / or polyurethane layers is also used as a secondary backing layer. These conventional secondary backing layers adversely affect the recyclability of artificial turf.

[0003] The art recognizes the need for artificial turf with improved recyclability. In particular, there is a need for an artificial turf having a secondary backing layer that provides suitable tuft lock properties and is also removable, allowing the artificial turf to be separated into its individual material components. Summary of the invention

[0004] The present disclosure provides an artificial turf. In one embodiment, the artificial turf includes a primary backing layer having a plurality of artificial turf yarns extending upward therefrom. The artificial turf also includes a secondary backing layer in contact with the primary backing layer. The secondary backing layer is made of an acrylic adhesive (interchangeably referred to as an "adhesive composition"). The acrylic adhesive comprises (i) an acrylic polymer composed of the following polymerized units: (a) a first monomer, the first monomer being an acrylic acid C4-C 18 The acrylic adhesive further comprises (ii) at least one inorganic neutralizing agent, and (iii) at least one surfactant.

[0005] definition

[0006] Any reference to the Periodic Table of the Elements is to the Periodic Table as published by CRC Press, Inc., 1990-1991. A group of elements in this table is referred to by a new notation for numbering the groups.

[0007] For purposes of U.S. patent practice, the contents of any referenced patent, patent application, or publication are incorporated by reference in their entirety (or their equivalent U.S. versions are incorporated by reference), particularly with respect to disclosure of definitions (to the extent not inconsistent with any definitions specifically provided in this disclosure).

[0008] Numerical ranges disclosed herein include all values ​​from the lower limit to the upper limit, and include the lower limit and the upper limit. For ranges containing explicit values ​​(e.g., 1 or 2, or 3 to 5, or 6, or 7), any sub-range between any two explicit values ​​is included (e.g., the above range 1 to 7 includes sub-ranges of 1 to 2, 2 to 6, 5 to 7, 3 to 7, 5 to 6, etc.).

[0009] Unless stated to the contrary, implicit from the context, or customary in the art, all parts and percentages are based on weight and all test methods are current as of the filing date of this disclosure.

[0010] An "acrylic polymer" is a polymer containing polymerized acrylic acid monomers and optionally may contain at least one comonomer. As used herein, an "acrylic acid monomer" is a monomer having the following structure (I):

[0011] Structure (I)

[0012]

[0013] Where R1 is H or C1-C 18 alkyl, and R2 is H or CH3. Non-limiting examples of acrylic monomers include acrylic acid, methacrylic acid, acrylic acid esters, and methacrylic acid esters.

[0014] The term "alkyl" is a monovalent hydrocarbon. A "hydrocarbon" is a compound consisting only of hydrogen and carbon atoms and containing straight and / or branched chains.

[0015] The terms "amine" and "amino" refer to unsubstituted amines (e.g., NH3 and NH4 + ) and substituted amines (e.g., mono-substituted amines or di-substituted amines), wherein the substituents may include, for example, alkyl, cycloalkyl, heterocyclyl, alkenyl, and aryl groups.

[0016] The term "blend" or "polymer blend" as used refers to a mixture of two or more polymers. A blend may be miscible or immiscible (not phase separated at the molecular level). A blend may or may not be phase separated. A blend may or may not contain one or more domain configurations, as determined by transmission electron spectroscopy, light scattering, x-ray scattering, and other methods known in the art. A blend may be achieved by physically mixing two or more polymers at a macroscopic level (e.g., melt blending resins or compounding) or a microscopic level (e.g., simultaneously formed in the same reactor).

[0017] The term "composition" refers to a mixture of materials comprising the composition, as well as reaction products and decomposition products formed from the materials of the composition.

[0018] The terms "comprising", "including", "having" and their derivatives are not intended to exclude the presence of any additional components, steps or procedures, whether or not these components, steps or procedures are specifically disclosed. For the avoidance of any doubt, unless stated to the contrary, all compositions claimed by using the term "comprising" may include any additional additives, adjuvants or compounds, whether in polymeric form or otherwise. In contrast, the term "consisting essentially of excludes any other components, steps or procedures (except those that are not essential to operability) from the scope of any subsequent statements. The term "consisting of" excludes any components, steps or procedures that are not specifically described or listed. Unless otherwise stated, the term "or" refers to the listed members individually and in any combination. The use of the singular includes the use of the plural, and vice versa.

[0019] "Ethylene-based polymers" or "ethylene polymers" are polymers that contain a majority amount of polymerized ethylene, based on the weight of the polymer, and optionally may contain at least one comonomer. Ethylene-based polymers typically contain at least 50 mole percent (mol%) units derived from ethylene (based on the total amount of polymerizable monomers).

[0020] An "olefin-based polymer" is a polymer that contains, in polymerized form, a majority mole % of polymerized olefin monomer (based on the total amount of polymerizable monomers) and optionally may contain at least one comonomer. Non-limiting examples of olefin-based polymers include ethylene-based polymers and propylene-based polymers.

[0021] As used herein, the term "polymer" or "polymeric material" refers to a compound prepared by polymerizing monomers, whether monomers of the same type or different types, which provide multiple and / or repeating "units" or "monomer units" constituting the polymer in a polymerized form. Therefore, the general term polymer covers the term homopolymer, which is usually used to refer to polymers prepared from only one type of monomer, and the term copolymer, which is usually used to refer to polymers prepared from at least two types of monomers. It also covers all forms of copolymers, such as random copolymers, block copolymers, etc. The terms "ethylene / α-olefin polymer" and "propylene / α-olefin polymer" refer to copolymers prepared by polymerizing ethylene or propylene and one or more additional polymerizable α-olefin monomers, respectively, as described above. It should be noted that although polymers are often referred to as "made of" one or more specified monomers, "based on" a specified monomer or monomer type, "containing" a specified monomer content, etc., in this context, the term "monomer" should be understood to refer to the polymerized residue of the specified monomer rather than the unpolymerized substance. Generally, the polymers herein are referred to as "units" based on the polymerized form of the corresponding monomers.

[0022] "Propylene-based polymers" are polymers that contain a majority amount of polymerized propylene, based on the weight of the polymer, and optionally may include at least one comonomer. Propylene-based polymers typically contain at least 50 mole percent (mol%) units derived from propylene (based on the total amount of polymerizable monomers).

[0023] Test Method

[0024] Coating weight. Acrylic adhesive coating weight is expressed as the weight of dry adhesive on a standard area of ​​material in grams per square meter (gsm or g / m 2 The conditions for drying the coating on the primary backing layer include a drying temperature of 100° C. and a drying time of 15 to 20 minutes. The size of the sample on which the coating was applied was 15 cm×15 cm.

[0025] Removability. The removability of the secondary backing layer is defined as follows:

[0026]

[0027] Removability is defined as the difference in tuft lock after washing and before washing. A high removability means that the tuft lock has been reduced enough to ensure proper separation of the yarn from the primary backing afterwards, while a low removability would mean that no secondary backing has been removed and therefore separation of the yarn and primary backing has not occurred.

[0028] The tuft lock test measures the retraction force (in Newtons / inch or N / inch) required to remove a yarn tuft from a primary backing layer. The tuft lock test is performed according to ISO 4919. The process begins with mounting the base plate so that it is flat in a plane perpendicular to the direction of tuft retraction. One of the entire tufts is selected and attached to the fixture, while the carpet should be clamped to the base plate. The test is performed according to the conditions in the table below. The test is repeated for a minimum of 20 tufts spread over the sample. The results are then recorded as the average tuft retraction force. The tuft lock conditions are provided in the table below. The size of the sample is 15 cm×15 cm.

[0029]

[0030] BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a side view of an artificial turf according to one embodiment of the present disclosure.

[0032] Figure 2 is a graph showing the tuft locks obtained on the comparative samples and the inventive examples before being subjected to a washing step. DETAILED DESCRIPTION

[0033] The present disclosure provides an artificial turf. In one embodiment, the artificial turf includes a primary backing layer having a plurality of artificial turf yarns extending upward therefrom. The artificial turf also includes a secondary backing layer in contact with the primary backing layer. The secondary backing layer is made of an acrylic adhesive (interchangeably referred to as an "adhesive composition"). The acrylic adhesive comprises (i) an acrylic polymer composed of the following polymerized units: (a) a first monomer, the first monomer being an acrylic acid C4-C 18 The acrylic adhesive further comprises (ii) at least one inorganic neutralizing agent, and (iii) at least one surfactant.

[0034] Figure 1 An embodiment of an artificial turf 10 of the present invention is shown having a primary backing layer 13 having a plurality of artificial turf yarns 11 extending upwardly therefrom. As used herein, the term "artificial turf" is a carpet-like covering having substantially upright, or upright polymer chains of artificial turf yarns 11 extending upwardly from a substrate, which is the primary backing layer 13. The artificial turf 10 may optionally include a filler 12 and a shock absorbing layer 15. The artificial turf 10 also includes a secondary backing layer 14. The secondary backing layer 14 contacts the primary backing layer 13. As shown in FIG. Figure 1As shown, the artificial turf yarn 11, the primary backing layer 13, the secondary backing layer 14 and the shock absorbing layer 15 may be attached to each other, and the filling material 12 may be spread on top of the artificial turf yarn 11. The artificial turf 10 may be set on the ground 16 or other desired surface.

[0035] The artificial turf 10 of the present invention includes a plurality of artificial turf yarns 11 extending upward from a primary backing layer 13. As used herein, the term "artificial turf yarn" or "yarn" hereinafter includes fibrillated tape yarn, coextruded tape yarn, single tape yarn and monofilament yarn. "Fibrillated tape" or "fibrillated tape yarn" is a cast extrusion film cut into a tape (usually about 1 cm in width), the film is stretched and a long slit is cut (fibrillated) into a tape, so that the size of the grass blade is a tape. "Monofilament yarn" is extruded into individual yarns or strands with a desired cross-sectional shape and thickness, and then the yarn is oriented and relaxed in a hot oven. Artificial turf yarn forms polymer strands of artificial turf. Artificial turf requires resilience (rebound), toughness, flexibility, ductility and durability. Therefore, artificial turf yarn excludes yarns for fabrics (i.e., woven and / or knitted fabrics).

[0036] The artificial turf yarn 11 is composed of a polymer material. Non-limiting examples of polymer materials suitable for yarns include olefin-based polymers (such as propylene-based polymers and / or ethylene-based polymers), polyesters, nylons, and combinations thereof. In one embodiment, the artificial turf yarn 11 is composed of an ethylene-based polymer.

[0037] The artificial turf 10 may optionally include an infill 12. Non-limiting examples of infill materials include mixtures of granulated rubber particles such as SBR (styrene butadiene rubber) recycled from automobile tires, EPDM (ethylene / propylene / terpolymer), other vulcanized rubbers or rubber recycled from belts, thermoplastic elastomers (TPE), thermoplastic vulcanizates (TPV), and mixtures thereof.

[0038] The primary backing layer 13 is one or more sheets to which the artificial turf yarn 11 is sewn or woven so that the artificial turf yarn 11 extends outward from the top side of the primary backing layer 13. The primary backing layer can be a polymer sheet of a woven fabric or a polymer sheet of a non-woven fabric. The primary backing layer provides dimensional stability for the artificial turf system.

[0039] Non-limiting examples of polymer materials suitable for the primary backing layer include styrene-butadiene (SB) latex and propylene-based polymers. In one embodiment, the primary backing layer is composed of an olefin-based polymer (such as a propylene-based polymer). In another embodiment, the primary backing layer is composed of a propylene homopolymer (or "polypropylene").

[0040] The artificial turf 10 may optionally include a shock absorbing layer 15 below the secondary backing layer 14 of the artificial turf 10. The shock absorbing layer 15 may be made of polyurethane, PVC foam or polyurethane foam, rubber, closed-cell cross-linked polyethylene foam, polyurethane backing with voids, elastomeric foam of polyvinyl chloride, polyethylene, polyurethane, polypropylene, and mixtures thereof. Non-limiting examples of the shock absorbing layer include, for example ENFORCE TM Sports Polyurethane Systems and ENHANCE TM Sports polyurethane system.

[0041] The artificial turf 10 may optionally include a drainage system ( Figure 1 The drainage system allows water to be removed from the artificial turf 10 and prevents the artificial turf 10 from being soaked by water. Non-limiting examples of drainage systems include stone-based drainage systems, EXCELDRAIN TM Sheet 100, EXCELDRAIN TM Sheet 200 and EXCELDRAIN TM EX-T STRIP (available from American Wick Drain Corp., Monroe, NC).

[0042] The secondary backing layer 14 is a material layer that is in direct contact with the bottom side of the primary backing layer 13 and provides a tuft lock to the artificial turf yarn 11. The term "in direct contact with" or "direct contact" refers to the following layer configuration, whereby the first layer is positioned next to the second layer, and there is no intermediate layer or intermediate structure between the first layer and the second layer. The "tuft lock" of the artificial turf yarn is defined as the force (in N / inch) required to remove a bundle of yarn from the primary backing layer. This parameter is required in landscaping as well as sports applications to ensure the correct durability of the field, because the lack of tuft lock will result in low durability of the field.

[0043] The secondary backing layer comprises an acrylic adhesive (interchangeably referred to as an "adhesive composition"). The acrylic adhesive comprises an acrylic polymer composed of the following polymerized units: (a) a first acrylic acid-based monomer, the adhesive being an acrylic acid C4-C 18 (b) a second acrylic acid-based monomer selected from the group consisting of acrylic acid, methacrylic acid, C1-C3 alkyl acrylate optionally containing a hydroxyl group, and combinations thereof.

[0044] Suitable acrylic acid C4-C 18Non-limiting examples of alkyl esters include butyl acrylate (BA), butyl methacrylate, 2-ethylhexyl acrylate (2-EHA), octyl acrylate, isooctyl methacrylate, decyl methacrylate, isodecyl methacrylate, lauryl methacrylate, pentadecyl methacrylate, and octadecyl methacrylate.

[0045] Non-limiting examples of suitable C1-C3 alkyl acrylates optionally containing hydroxyl groups include methyl acrylate, ethyl acrylate, propyl acrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, and hydroxypropyl methacrylate.

[0046] In one embodiment, the acrylic polymer contains no olefin monomers. Non-limiting examples of olefin monomers (excluded from the acrylic polymer) include ethylene, propylene, 1,3-butadiene, pentene, hexene, octene, styrene, and 5-ethylidene-2-norbornene.

[0047] In one embodiment, the acrylic polymer is free of vinyl chloride monomers.

[0048] In one embodiment, the acrylic polymer contains a third acrylic acid-based monomer having a carboxylic acid functional group. Non-limiting examples of the third monomer include acrylic acid, methacrylic acid, and itaconic acid. In one embodiment, the acrylic polymer is a 2-ethylhexyl acrylate / ethyl acrylate / acrylic acid terpolymer.

[0049] In one embodiment, the acrylic polymer contains: (i) 50 wt % to 90 wt %, 60 wt % to 80 wt %, 65 wt % to 75 wt %, or 50 wt % to 71 wt % of a first monomer, based on the total weight of the acrylic polymer, wherein the first monomer is an acrylic acid C4-C 18 alkyl esters, (ii) 20 wt % to 50 wt %, greater than 20 wt % to 40 wt % or 25 wt % to 40 wt % of a second monomer selected from acrylic acid, methacrylic acid and optionally a hydroxyl-containing C1-C3 alkyl acrylate, and optionally (iii) 0.5 wt % to 20 wt %, 1 wt % to 10 wt % or 1 wt % to 5 wt % of a third monomer having a carboxylic acid functional group.

[0050] In addition to the acrylic polymer, the adhesive composition for the secondary backing layer also includes an inorganic neutralizer. The term "neutralizer" refers to an alkaline substance that can react with an acidic substance in an acid-base reaction. The term "inorganic neutralizer" refers to a neutralizer composed of a metal cation and an alkaline anion. Non-limiting examples of metal cations include cations of alkali metals (Group I of the periodic table) and alkaline earth metals (Group II of the periodic table), such as Li + 、Na + , K+ , Cs + Mg 2+ and Ca 2+ Non-limiting examples of basic anions include hydroxide (OH - ). Non-limiting examples of suitable inorganic neutralizing agents include sodium hydroxide, potassium hydroxide, lithium hydroxide, and combinations thereof.

[0051] In one embodiment, the at least one inorganic neutralizing agent is sodium hydroxide.

[0052] In one embodiment, the inorganic neutralizing agent does not include an organic amine, or does not contain an amino group. In other words, the inorganic neutralizing agent does not include or contain a nitrogen atom (N).

[0053] The acrylic adhesive of the secondary backing layer includes at least one surfactant. The surfactant may be a fatty alcohol ether sulfate. In one embodiment, the fatty alcohol ether sulfate includes C 12 -C 14 Sodium salt of fatty alcohol ether sulfate. Commercially available examples of suitable surfactants include, but are not limited to FES 77 (containing sodium ethoxylated lauryl ether sulfate), FES 32 (containing sodium salt of fatty alcohol polyglycol ether sulfate), FES 993 (containing sodium salt of fatty alcohol polyglycol ether sulfate), and FES 61 (containing sodium salt of fatty alcohol polyglycol ether sulfate), each available from BASF.

[0054] In one embodiment, the acrylic adhesive comprises other surfactants. Non-limiting examples of suitable additional surfactants include sodium dioctyl sulfosuccinate and acetylenic glycol ethylene oxide / propylene oxide adduct surfactants.

[0055] In one embodiment, the acrylic adhesive contains 0.1 wt % to 3 wt %, or 0.2 wt % to 1.5 wt %, or 0.2 wt % to 1 wt % of dioctyl sodium sulfosuccinate surfactant, based on the total weight of the acrylic adhesive. Non-limiting examples of suitable commercially available dioctyl sodium sulfosuccinate surfactants are OT-75.

[0056] In one embodiment, the acrylic adhesive contains 0.05 wt % to 1.5 wt %, or 0.1 wt % to 1 wt %, or 0.1 wt % to 0.5 wt % of an acetylene glycol ethylene oxide / propylene oxide adduct surfactant, based on the total weight of the adhesive composition. Non-limiting examples of suitable commercially available acetylene glycol ethylene oxide / propylene oxide adduct surfactants include 440, 104. 420, 450, 465 and 485.

[0057] In one embodiment, the acetylenic glycol ethylene oxide / propylene oxide adduct surfactant may be replaced or combined with a nonionic branched secondary alcohol ethoxylate surfactant. Non-limiting examples of suitable nonionic branched secondary alcohol ethoxylate surfactants include TERGITOL TM TMN-10.

[0058] In one embodiment, the adhesive composition optionally contains a defoamer. Commercially available defoamers include, but are not limited to, Tego Antifoam 2291, Foamaster MO S090, Tego Antifoam KS 53, Tego Antifoam 2450, Tego Antifoam D 2315, BYK 011.

[0059] Additionally, acid-containing cross-linked acrylic emulsion copolymers, such as alkali swellable acrylic emulsions (ASE), may be added to aid in the rheology and wash-off properties of the polymer. Acceptable additives include, but are not limited to, ACRYSOL TM ASE-60. In addition, rheology modifiers such as hydrophobically modified alkali swellable (HASE) associative thickeners may be added to aid in the rheology and wash-off properties of the polymer. Acceptable additives include, but are not limited to, ACRYSOL TM RM-7 and ACRYSOL TM RM-55.

[0060] In one embodiment, the acrylic adhesive contains water.

[0061] Other additives that can be added to the acrylic adhesive include one or more water-soluble additives that can improve the wash-off performance of the secondary backing layer. Non-limiting examples of water-soluble additives include synthetic water-soluble polymers such as polyethylene glycol (PEG), polyvinyl pyrrolidone (PVP), poly (vinyl alcohol) (PVOH), polyacrylic acid (PAA), polyacrylamide, N- (2-hydroxypropyl) methacrylamide (HPMA), divinyl ether-maleic anhydride (DIVEMA), polyoxazoline, polyphosphate, polyphosphazene; natural water-soluble polymers such as xanthan gum, pectin, chitosan derivatives, dextran, carrageenan, guar gum, cellulose ethers, hyaluronic acid (HA), albumin, starch or starch-based derivatives, or combinations thereof. Non-limiting examples of water-soluble additives include PEG 400, PEG 600, PEG1000, PEG1450, PEG3350, PEG8000, PVP K60, and PVP K90 with different molecular weights. In one embodiment, the acrylic adhesive comprises 0.05 wt % to 20 wt %, or 0.25 wt % to 10 wt % of one or more additives, based on the total weight of the acrylic adhesive.

[0062] In one embodiment, the acrylic adhesive is free or substantially free of one, some or all of the following: olefin monomers, crosslinking components, tackifiers, adipic acid dihydrazide (ADH), waxes, photocrosslinkable monomers, vinyl acetate, vinyl acetate derivatives, and any combination thereof.

[0063] In one embodiment, the acrylic adhesive forms a secondary backing layer and comprises:

[0064] 80 wt % to 99 wt %, or 85 wt % to 99 wt %, or 90 wt % to 99 wt %, or 95 wt % to 99 wt % of an acrylic polymer, based on the total weight of the acrylic adhesive;

[0065] 0.05 wt % to 5 wt %, or 0.5 wt % to 3 wt %, or 0.5 wt % to 1 wt % of at least one inorganic neutralizing agent, based on the total weight of the acrylic adhesive;

[0066] 0.1 wt % to 5 wt %, or 0.5 wt % to 3 wt %, or 1 wt % to 3 wt % of at least one surfactant, based on the total weight of the acrylic adhesive.

[0067] In one embodiment, the acrylic adhesive forms a secondary backing layer and comprises:

[0068] (1) Based on the total weight of the acrylic adhesive, 80 wt % to 99 wt %, or 85 wt % to 99 wt %, or 90 wt % to 99 wt %, or 95 wt % to 99 wt % of an acrylic polymer, the acrylic polymer being a 2-ethylhexyl acrylate / ethyl acrylate / acrylic acid terpolymer, the terpolymer consisting of:

[0069] (i) 50 wt% to 90 wt%, 60 wt% to 80 wt%, 65 wt% to 75 wt%, or 50 wt% to 71 wt% of 2-ethylhexyl acrylate monomer, based on the total weight of the terpolymer;

[0070] (ii) 20 wt% to 50 wt%, greater than 20 wt% to 40 wt%, or 25 wt% to 40 wt% of ethyl acrylate monomer, based on the total weight of the terpolymer; and

[0071] (iii) 0.5 wt % to 20 wt %, or 1 wt % to 10 wt %, or 1 wt % to 5 wt % of acrylic acid monomer, based on the total weight of the terpolymer;

[0072] (2) 0.05 wt % to 5 wt %, or 0.5 wt % to 3 wt %, or 0.5 wt % to 1 wt % of at least one inorganic neutralizing agent, based on the total weight of the acrylic adhesive, the inorganic neutralizing agent being sodium hydroxide; and

[0073] (3) based on the total weight of the acrylic adhesive, 0.1 wt % to 5 wt %, or 0.5 wt % to 3 wt %, or 1 wt % to 3 wt % of at least one surfactant, the surfactant being C 12 -C 14 Sodium salt of fatty alcohol ether sulfate or sodium ethoxylated lauryl ether sulfate; and

[0074] The acrylic adhesive is in direct contact with the primary backing layer at a coating weight of 10 grams per square meter (gsm) to 500 gsm, or 100 gsm to 300 gsm, or 100 gsm to 200 gsm.

[0075] The present disclosure provides a method. The method includes providing a batch containing the artificial turf of the present invention and a washing solution. The artificial turf includes a primary backing layer having a plurality of artificial turf yarns extending upwardly therefrom. The artificial turf also includes a secondary backing layer in contact with the primary backing layer. The secondary backing layer includes an acrylic adhesive. The acrylic adhesive includes (i) an acrylic polymer composed of the following polymerized units: (a) a first monomer, the first monomer being an acrylic acid C4-C 18(b) a second monomer selected from acrylic acid, methacrylic acid and C1-C3 alkyl acrylates optionally containing a hydroxyl group, (ii) at least one inorganic neutralizing agent, and (iii) at least one surfactant.

[0076] The method includes providing a batch containing the artificial turf of the present invention and a washing solution. The washing solution of the batch includes water, a surfactant and an alkali. Non-limiting examples of surfactants that can be included in the washing solution include secondary alcohol ethoxylates. In one embodiment, the surfactant in the washing solution includes a non-ionic secondary alcohol ethoxylate surfactant. Non-limiting examples of suitable non-ionic secondary alcohol ethoxylate surfactants include TERGITOL TM 15-S-9. In one embodiment, the washing solution contains 0.05 wt% to 5 wt%, or 0.1 wt% to 3 wt%, or 0.5 wt% to 1 wt% of the surfactant, based on the total weight of the washing solution.

[0077] The washing solution comprises an alkali. A non-limiting example of a suitable alkali that may be included in the washing solution is sodium hydroxide. In one embodiment, the alkali in the washing solution is sodium hydroxide, and it is added to adjust the pH of the washing bath to a pH of 7 to 14 or 10 to 14.

[0078] In one embodiment, the wash solution comprises 0.05 wt % to 5 wt %, or 0.5 wt % to 3 wt %, or 1 wt % or 2 wt % base, based on the total weight of the wash solution.

[0079] In one embodiment, the washing solution comprises (i) water, (ii) 0.05 wt % to 5 wt %, or 0.1 wt % to 3 wt %, or 0.5 wt % to 1 wt % of a surfactant, based on the total weight of the washing solution, the surfactant comprising a nonionic secondary alcohol ethoxylate, and (iii) 0.05 wt % to 5 wt %, or 0.5 wt % to 3 wt %, or 1 wt % to 2 wt % of a base, based on the total weight of the washing solution, the base being sodium hydroxide.

[0080] The method includes contacting the artificial turf with a washing solution under conditions sufficient to separate the secondary backing layer from the primary backing layer.

[0081] In one embodiment, the term "contacting" refers to immersing the artificial turf in a washing solution. The term "under conditions sufficient to separate the secondary backing layer from the primary backing layer" includes (i) introducing the batch material into a container (such as, for example, a mixing device) and (ii) stirring the batch material (or mixture) under conditions sufficient to separate the secondary backing layer from the primary backing layer. The mixing device can mechanically stir the batch material, or the batch material can be manually stirred with a stirring rod. Non-limiting examples of suitable mixing devices include buckets, buckets, flasks, beakers, horizontal ribbon mixers, paddle mixers, drum mixers, drum mixers, static mixers, planetary mixers, and premixers. Any mixing device in the aforementioned mixing device can be equipped with suitable equipment to mix, stir, blend, rotate, and / or stir the batch material (artificial turf and washing solution) therein. The mixing device mixes the artificial turf with the washing solution and fully contacts the secondary backing layer with the washing solution.

[0082] The term "agitation" refers to the motion of mixing, blending, spinning, tumbling, shaking and / or stirring the artificial turf in the wash solution.

[0083] The term "conditions sufficient to separate the secondary backing layer from the primary backing layer" also includes operating parameters that promote neutralization of the secondary backing layer. In one embodiment, the conditions sufficient to separate the secondary backing layer from the primary backing layer include (i) the agitation rate of the batch comprising artificial turf and the washing solution, (ii) the temperature of the washing solution, and (iii) the pH of the washing solution.

[0084] In one embodiment, the conditions sufficient to separate the secondary backing layer from the primary backing layer include one, some, or all of the following parameters:

[0085] (i) agitating the artificial turf immersed in the washing solution at a rate of 50 rpm to 1000 rpm, or 100 rpm to 600 rpm, or 100 rpm to 500 rpm; and / or

[0086] (ii) heating the wash solution to a temperature of 20°C to 90°C, or 30°C to 85°C, or 50°C to 85°C, or 60°C to 85°C, or 70°C to 85°C; and / or

[0087] (iii) adjusting the pH of the washing solution to 7 to 14, or 7 to 10, or 7 to 8. In another embodiment, only the secondary backing layer swells, separates and disperses in the washing bath, and the rest of the artificial turf does not react with the washing solution.

[0088] Without being bound by a particular theory, it is believed that the wash solution swells the secondary backing layer causing some or all of the secondary backing layer to separate and move away from the primary backing layer.The term "separating" means removing some or all of the secondary backing layer from the primary backing layer.

[0089] In one embodiment, the method further comprises removing the artificial turf (having the primary backing layer and a portion of the secondary backing layer or having no secondary backing layer) from the washing solution and rinsing the artificial turf with water.

[0090] In one embodiment, the method comprises:

[0091] (1) providing a batch comprising artificial turf and a washing solution, wherein the artificial turf comprises

[0092] A. a primary backing layer having a plurality of artificial turf yarns extending upwardly therefrom; and

[0093] B. A secondary backing layer, the secondary backing layer is in contact with the primary backing layer, the secondary backing layer comprises an acrylic adhesive, the acrylic adhesive comprises

[0094] (i) based on the total weight of the acrylic adhesive, 80 wt % to 99 wt %, or 85 wt % to 99 wt %, or 90 wt % to 99 wt %, or 95 wt % to 99 wt % of an acrylic polymer comprising the following polymerized units:

[0095] (a) based on the total weight of the acrylic polymer, 50 wt% to 90 wt%, 60 wt% to 80 wt%, 65 wt% to 75 wt%, or 50 wt% to 71 wt% of the first monomer, the first monomer being acrylic acid C4-C 18 Alkyl esters; and

[0096] (b) 20 to 50 wt%, greater than 20 to 40 wt%, or 25 to 40 wt%, based on the total weight of the acrylic polymer, of a second monomer selected from the group consisting of C1-C3 alkyl acrylates optionally containing hydroxyl groups, acrylic acid, and methacrylic acid; and

[0097] (c) 0.5 wt % to 20 wt %, 1 wt % to 10 wt %, or 1 wt % to 5 wt % of a third monomer having a carboxylic acid functional group, based on the total weight of the acrylic polymer;

[0098] (ii) 0.05 wt % to 5 wt %, or 0.5 wt % to 3 wt %, or 0.5 wt % to 1 wt % of at least one inorganic neutralizing agent (such as sodium hydroxide), based on the total weight of the acrylic adhesive; and

[0099] (iii) 0.05 wt % to 5 wt %, or 0.5 wt % to 3 wt %, or 1 wt % to 3 wt % of at least one surfactant (such as sodium ethoxylated lauryl ether sulfate), based on the total weight of the acrylic adhesive; and

[0100] A washing solution comprising

[0101] (i) water,

[0102] (ii) 0 wt %, or 0.05 wt % to 5 wt %, or 0.1 wt % to 3 wt %, or 0.5 wt % to 1 wt % of a surfactant (such as, for example, a secondary alcohol ethoxylate), based on the total weight of the wash solution, and

[0103] (iii) 0.1 to 5 wt %, or 0.5 to 3 wt %, or 1 to 2 wt % of a base (such as, for example, sodium hydroxide), based on the total weight of the wash solution; and

[0104] (2) immersing the artificial turf in the washing solution;

[0105] (3) agitating the artificial turf and the washing solution under conditions sufficient to separate the secondary backing layer; and

[0106] (4) Removing the secondary backing layer from the primary backing layer.

[0107] Artificial turf cannot be effectively recycled without separating the individual components from each other. Conventional secondary backing layers (such as polyurethane or rubber latex) cannot be easily separated from the rest of the artificial turf components. Mechanical waste treatment is a common procedure used in the recycling industry, however the quality of the waste stream is low due to incompatibilities between the different materials that make up the artificial turf system. Developing an artificial turf system that can be separated into its individual components is of major interest to the industry as it would allow for a cleaner waste stream.

[0108] The artificial turf of the invention and the method of the invention advantageously enable the secondary backing layer to be removed from the primary backing layer, enabling the individual components; turf yarn, primary backing layer and shock absorbing layer to be separated from each other. The low density components will float on the surface of the washing solution, as each component has a density of less than 1 g / cm 3 The unit density of the secondary backing will be reduced and the acrylic binder from the secondary backing will be dispersed in the washing solution in the form of small particles which can be easily filtered out. In this way, each individual artificial turf component can be easily removed from the recycling stream. The turf yarn and the primary backing can be mechanically recycled together or they can be further separated, but the quality of the waste stream will be further improved by separating the secondary backing layer from the artificial turf structure.

[0109] By way of example and not limitation, some embodiments of the present disclosure will now be described in detail in the following examples.

[0110] Example

[0111] 1. Materials

[0112] The materials used in the inventive examples ("IE") and comparative samples ("CS") are provided in Table 1 below.

[0113] Table 1

[0114]

[0115]

[0116] A. Preparation of CS1-CS3

[0117] Comparative samples (CS) CS1 and CS2 were prepared using uncoated artificial turf samples, where the secondary backing layer was manually applied to the primary backing layer 1 (with artificial turf yarn 1) by brush and then dried in an oven. For CS1, the secondary backing layer was based on a material called HYPOD TM The primary backing layer was fixed to the primary backing layer by a Dow latex latex of commercial origin. The secondary backing layer was fixed to the primary backing layer by a brush.

[0118] B. Synthesis of Acrylic Polymer in Acrylic Binder in IE1 Secondary Backing Layer

[0119] A monomer emulsion containing 86.31 wt % of a monomer mixture was prepared by mixing: (i) a monomer composition containing 71 wt % of a first monomer, 2-ethylhexyl acrylate, 26 wt % of a second monomer, ethyl acrylate, and 3 wt % of a third monomer, acrylic acid, based on the total weight of the first, second, and third monomers, (ii) sodium dodecylbenzene sulfonate (branched), (iii) Aerosol A-102, and (iv) a small amount of sodium hydroxide (monomer emulsion buffer). The wt % is based on the total weight of the polymer batch / emulsion.

[0120] With the reactor water maintained at 90-92°C, heating was stopped and a solution of 0.054 wt% sodium carbonate and 0.312 wt% sodium persulfate in water was added to the reactor.

[0121] 0.22 wt% of the polymer latex with seeds of 250 nm diameter was added to the kettle and held for two minutes, followed by the addition of 0.13 wt% of the second polymer latex with seeds of 100 nm diameter.

[0122] With the reactor at 83 °C, a step-addition thermal polymerization was conducted by feeding the monomer emulsion into the reactor over 150 minutes along with a co-feed of sodium persulfate (0.23 wt%) while maintaining the reactor temperature between 85 and 87 °C.

[0123] After adding 60 wt% of the monomer emulsion feed, 0.26 wt% of a polymer latex having seeds with diameters <50 nm (wt% based on weight of monomer composition) was added to the reactor to produce a third smaller particle size polymer mode.

[0124] At 84°C, the accelerator was added and then a chase redox pair of tert-butyl hydroperoxide (0.16 wt%) and D(-)-isoascorbic acid (0.064 wt%) co-feed reagents were fed to the reactor over 45 minutes to reduce the residual monomer level to the final specification.

[0125] At a temperature of 55° C. or less, the reaction was adjusted to a pH of 4 to 4.5 by adding ammonium hydroxide to produce an acrylic polymer containing 71 wt % 2-EHA, 26 wt % EA, and 3 wt % AA based on the total weight of the acrylic polymer.

[0126] C. Preparation of Acrylic Adhesive in IE1 Secondary Backing Layer

[0127] A post addition solution containing 0.26 wt % Surfynol 440, 1.21 wt % Disponil Fes 77 and 0.42 wt % Aerosol OT-75 was added to the acrylic polymer in the kettle over 30 minutes while cooling to 40-45° C., where the weight percentages are based on the total weight of the emulsion.

[0128] At a temperature below 45° C., an inorganic neutralizer (10 wt % sodium hydroxide in water) was added until the latex pH reached 8 to 8.5. Fifteen minutes later, the biocide package was added and the final solids were about 57.5 to 58.5 wt % based on the total weight of the emulsion.

[0129] The obtained acrylic adhesive (adhesive composition) was filtered through a 100-mesh bag and filled.

[0130] D. Preparation of IE1

[0131] The obtained acrylic adhesive was applied to the primary backing layer 1 (with artificial turf yarn 1) by a paint brush at a coating weight of 150 gsm (wet) and then dried in an oven at 100° C. for 15 to 20 minutes. The samples were then conditioned in a climate temperature controlled room (CTR) at 23° C. ± 2° C. and 50% RH ± 5% RH. Tuft lock testing was performed before washing the acrylic adhesive (Inventive Example 1 or “IE1”).

[0132] E. Washing Procedure for CS1, CS2 and IE1

[0133] A mixture containing 20 kg water, 203 g NaOH (1 wt % aqueous solution) and 100 g TERGITOL TM The washing was carried out by washing with a washing solution of 15-S-9 (secondary alcohol ethoxylate) (0.5 wt% aqueous solution). After the washing solution was prepared, the temperature of the washing solution was increased to 75°C.

[0134] CS1, CS2, and IE1 were added and immersed in the wash solution. The mixing speed of the wash solution was set to 350 rpm. After agitating CS1, CS2, and IE1 in the wash solution for 12 minutes, the samples were removed with tweezers, rinsed with fresh water, and then dried overnight in a convection oven at 50°C.

[0135] F. Results

[0136] The tuft lock before the washing (pre-washing) step was obtained (measured) on CS1, CS2 and IE1 as reference. The tuft lock values ​​(pre-washing) for CS1, CS2, CS3 and IE1 are shown in Figure 2 CS1 and CS2 had tuft lock values ​​between 50 N / inch and 60 N / inch, while IE1 had a tuft lock value of 20 N / inch. Compared to the tuft lock value of CS3 without any coating on its secondary backing layer (i.e., less than 5 N / inch), IE1 showed acceptable tuft lock performance. Even though the tuft lock values ​​obtained on CS1 and CS2 were higher than that of IE1, IE1 also showed tuft lock performance relevant to specific artificial turf yarn applications (e.g., landscaping or leisure).

[0137] Tuftlock measurements after caustic bath washing were also performed on CS1, CS2, and IE1 (after the washing step) to determine whether the secondary backing layer was removed. The washability of the secondary backing layer in CS1, CS2, and IE1 in the washing solution was defined as removability. The removability of CS1, CS2, and IE1 is provided in Table 2 below.

[0138] Table 2: % Removability of Secondary Backing Layers Containing CS1, CS2, and IE1

[0139] sample Removability % CS1 0 CS2 0 IE1 >60

[0140] The removability of the secondary backing layer in IE1 was greater than 60%, while the removability of the secondary backing layer in CS1 and CS2 was 0%.

[0141] Overall, IE1 contains a secondary backing layer that exhibits acceptable tuft lock performance (20 N / inch) and has a high removability (greater than 60%), allowing the artificial turf of the present invention to be recycled.

[0142] It is particularly intended that the present disclosure is not limited to the embodiments and descriptions contained herein, but includes modifications of those embodiments including parts of the embodiments and combinations of elements of different embodiments as appear within the scope of the following claims.

Claims

1. An artificial turf, comprising: A. a primary backing layer having a plurality of artificial turf yarns extending upwardly therefrom; and B. A secondary backing layer, the secondary backing layer is in contact with the primary backing layer, the secondary backing layer comprises an acrylic adhesive, the acrylic adhesive comprises (i) an acrylic acid polymer comprising the following polymerized units: (a) a first monomer, wherein the first monomer is acrylic acid C4-C 18 Alkyl esters; and (b) a second monomer selected from the group consisting of acrylic acid, methacrylic acid and a C1-C3 alkyl acrylate optionally containing a hydroxyl group; (ii) at least one inorganic neutralizing agent; and (iii) at least one surfactant.

2. The artificial turf according to claim 1, wherein the acrylic acid C4-C 18 The alkyl ester is selected from the group consisting of butyl acrylate, butyl methacrylate, ethylhexyl acrylate, octyl acrylate, isooctyl methacrylate, decyl methacrylate, isodecyl methacrylate, lauryl methacrylate, pentadecyl methacrylate, and octadecyl methacrylate.

3. The artificial turf according to claim 1 or 2, wherein the C1-C3 alkyl acrylate optionally containing a hydroxyl group is selected from the group consisting of methyl acrylate, ethyl acrylate, propyl acrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate and hydroxypropyl methacrylate.

4. The artificial turf according to any one of claims 1 to 3, wherein the acrylic polymer is a terpolymer of 2-ethylhexyl acrylate / ethyl acrylate / acrylic acid.

5. The artificial turf according to claim 4, wherein the terpolymer comprises, based on the total weight of the terpolymer: (i) 50% to 71% by weight of ethylhexyl acrylate; (ii) 25 to 40 wt. % of ethyl acrylate, and (iii) 1 to 10 wt% of acrylic acid.

6. Artificial turf according to any one of claims 1 to 5, wherein the at least one inorganic neutralizing agent is sodium hydroxide.

7. Artificial turf according to any one of claims 1 to 6, wherein the at least one surfactant comprises a fatty alcohol ether sulfate.

8. The artificial turf according to any one of claims 1 to 7, wherein the acrylic adhesive comprises, based on the total weight of the acrylic adhesive: 80 to 99 wt % of said acrylic polymer; 0.05 wt % to 5 wt % of the at least one inorganic neutralizing agent; and 0.1 wt. % to 5 wt. % of the at least one surfactant.

9. A method comprising: (1) Providing a batch comprising artificial turf and a washing solution, wherein the artificial turf comprises: A. a primary backing layer having a plurality of artificial turf yarns extending upwardly therefrom; and B. A secondary backing layer, the secondary backing layer is in contact with the primary backing layer, the secondary backing layer comprises an acrylic adhesive, the acrylic adhesive comprises (i) an acrylic acid polymer comprising the following polymerized units: (a) a first monomer, wherein the first monomer is acrylic acid C4-C 18 Alkyl esters; and (b) a second monomer selected from the group consisting of C1-C3 alkyl acrylates optionally containing a hydroxyl group, acrylic acid and methacrylic acid; (ii) at least one inorganic neutralizing agent; and (iii) at least one surfactant; and The washing solution comprises water, a surfactant and an alkali; (2) contacting the artificial turf with the washing solution under conditions sufficient to separate the secondary backing layer from the primary backing layer.

10. The method of claim 9, wherein the contacting step comprises immersing the artificial turf in the washing solution and agitating the artificial turf and the washing solution.

11. The process according to claim 9 or 10, wherein the base is sodium hydroxide.

12. The method of any one of claims 9 to 11, wherein the surfactant comprises a nonionic secondary alcohol ethoxylate.

13. The method of any one of claims 9 to 12, wherein the scrubbing solution has 0.1 wt% to 5 wt% of the base, based on the total weight of the scrubbing solution.

14. The method of any one of claims 9 to 13, wherein the wash solution has 0.05 wt% to 5 wt% of the surfactant, based on the total weight of the wash solution.

Images