Artificial mushroom filling material and artificial mushroom having passive temperature control

Abstract

A filling material (151) for artificial ganoderma, comprising a plurality of particles (141) at least partially coated by a PCM shell layer (143) containing at least one PCM material, and a thermally conductive shell layer (145) formed on the PCM shell layer (143).

Description

Technical Field

[0001] The present invention generally relates to a filling material for artificial turf, and more specifically, to a filling material having passive temperature control and an artificial turf using the same.

Background Art

[0002] Artificial turf is easier to maintain than natural turf and has superior surface characteristics in many respects, so its use is increasing. Usually, artificial turf is manufactured by extruding a thermoplastic resin to form artificial turf fibers and inserting them into a carrier through a process known as tufting. The polymer fibers or blades on the surface of artificial turf often take the form of loops called pile. Often, a polymer resin is installed on the back side of the carrier to enhance the structural stability of the artificial turf and the tensile properties of the pile. Artificial turf is used in many applications, including household floor mats, sports arena surfaces such as soccer, football, rugby, tennis, golf, playgrounds, and landscaping.

Summary of the Invention

Problems to be Solved by the Invention

[0003] A problem with existing artificial turf is that they tend to overheat rapidly on sunny warm days.

[0004] The concept of using a phase change material ("PCM") to cool various surfaces is generally known. For example, U.S. Patent Application Publication No. US20130199755A1 describes a filling material for artificial turf having a PCM member, which reduces heat accumulation in or near the upper part of the artificial turf. Korean Patent Document No. KR102149423B1 describes a filling material for artificial turf having a PCM member, which reduces heat accumulation in or near the upper part of the artificial turf. Also described is a sandblast layer containing silica sand in a turf system.

[0005] Despite the aforementioned and other relatively limited attempts to use PCM for cooling the surface of artificial mushrooms, there has been no solution widely accepted in the market to date. Therefore, in order to provide a cooling measure for the surface of artificial mushrooms with satisfactory performance characteristics under various weather conditions over a long period, further improvement is needed.

[0006] Accordingly, an object of the present invention is to provide a filling material and artificial mushrooms having improved temperature control characteristics. Another object of the present invention is to provide a method for manufacturing such a filling material and artificial mushrooms.

Means for Solving the Problems

[0007] In one embodiment of the present invention, a filling material for artificial mushrooms having passive temperature control is provided. In certain embodiments, the filling material has a plurality of particles or fragments, at least a portion of which is coated by a shell layer having at least one PCM. The PCM is encapsulated in microcapsules or macro-capsules. The PCM includes paraffin wax encapsulated in microcapsules dispersed in a matrix of an acrylic or PU cured polymer. In certain embodiments, the microcapsules are encapsulated within larger macro-capsules.

[0008] The filling material may further have a heat conduction layer including a heat conductive material. The heat conductive material may preferably be granite, graphene, or a combination thereof. The heat conductive material may be dispersed within a polyurethane or acrylic polymer material. The heat conduction layer is installed on the PCM shell layer and the PCM shell layer may be at least partially coated.

[0009] The filling material is used between the turf blades in artificial turf, where the blades are maintained upright, providing the necessary cushioning and preventing or reducing overheating of the turf blades and the entire artificial turf structure during hot sunny days. The filling material is characterized by a combination of a PCM shell layer and a thermally conductive shell layer, thereby providing a more efficient way to prevent or reduce overheating of the artificial turf blades and the structure as a whole. Without wishing to be bound by theory, the thermally conductive material forms a continuous thermally conductive framework, and heat is transferred from the turf blades to the PCM dispersed in the PCM shell layer of the filler particles and also to the underlying turf structure, thus preventing the turf blades in contact with the user of the turf from overheating.

[0010] In particular, the present invention provides a filling material, an artificial turf structure (also simply referred to as artificial turf) using at least one PCM, and a method of forming the artificial turf structure, as defined in the independent claims. Various embodiments of the present invention are described in the dependent claims. Embodiments of the present invention can be freely combined with each other, unless they are mutually exclusive.

[0011] The filling material may be used with any type of artificial turf. In some embodiments, the artificial turf may have a carrier and artificial turf fibers incorporated into the carrier, wherein a first portion of the artificial turf fibers protrudes from the back side of the carrier, a second portion of the artificial turf fibers protrudes from the front side of the carrier, a third portion of the artificial turf fibers is inside the carrier, and a polyurethane backing formed on the back side of the carrier. The artificial turf is characterized in that the filling material of the present invention, including a PCM shell layer and a thermally conductive shell layer, is disposed between the turf fibers protruding over the upper side of the carrier.

[0012] In some embodiments, the PCM shell layer formed on the filler particles may have first and second PCM shell layers, and the second PCM shell layer is disposed on the first PCM shell layer. The first PCM shell layer includes at least one first PCM, and the second PCM shell layer includes at least one second PCM. The first and second PCMs may be dispersed within the first and second acrylic or polyurethane materials. Two or more PCMs having staggered melting points within a desired temperature control range may be added.

[0013] The thermal conduction layer provides improved thermal conductivity between the turf fibers (also referred to as turf blades) and the PCM shell layer. It has been recognized that the combination of the thermally conductive shell layer and the PCM shell layer is particularly significant in preventing the turf blades from overheating.

[0014] The at least one first and second PCMs may be the same or different and may have a melting point of 15°C to 45°C, preferably 25°C to 40°C, more preferably 25°C to 37°C. In some embodiments, the amount of PCM in the first PCM shell layer may be at least 5.0%, particularly 10 to 30%, and even 10 to 25% less than the amount of PCM in the second PCM shell layer.

[0015] In some embodiments, the thermally conductive cell layer may have an amount of graphene, graphite, or a combination of graphene and graphite in a weight ratio of 6.0 to 24 wt%, particularly 7.0 to 17.0 wt%, particularly 10.0 to 14.0 wt% based on the total weight of the thermally conductive sublayer.

[0016] The PCM may be in an amount of 5.0 to 12.5 wt%, particularly 6.0 to 10.0 wt%, particularly 7.0 to 9.0 wt% by weight ratio based on the total weight of the at least one PCM shell layer.

[0017] In some embodiments, at least one PCM shell layer may have a thickness of from 200 mm to 800 mm, particularly from 400 mm to 600 mm, and even more particularly from 450 mm to 550 mm.

[0018] In some embodiments, the thermally conductive shell layer has a thickness of from 5 mm to 500 mm, from 50 mm to 300 mm, preferably from 100 mm to 150 mm.

[0019] The PCM may be a paraffinic material including paraffin wax, preferably encapsulated within microcapsules or macro-capsules, and each macro-capsule has a plurality of micro-capsules. In some embodiments, the PCM is dispersed within a secondary support structure of hydrophilic silica powder, and the PCM solid may maintain its macro form.

[0020] The macro-capsules may have a particle size of from 200 to 800 micrometers, preferably from 200 to 400 micrometers, more preferably from 200 to 400 micrometers. The micro-capsules may have a particle size of from 15 to 30 micrometers.

[0021] In some embodiments, the thermally conductive material is a nano-graphite composite, and the content of nano-graphite may be in the range of 5.0 to 15.0 wt%, particularly 8.0 to 12.0 wt%, and even more particularly 9.0 to 11.0 wt% by weight ratio based on the total weight of the thermally conductive layer composition. The thermal conductivity gradually increases with the content of nano-graphite.

[0022] The turf fibers or blades may be composed of any suitable polymeric material, for example, including polyamide, polypropylene, and polyethylene. Preferably, the turf fibers or turf blades may be composed of a hydrophobic polyethylene selected from the group consisting of polyethylene homopolymers, polyethylene alloys, polyethylene copolymers, and polyethylene impact copolymers.

[0023] The step of incorporating the fungal fiber or blade into the carrier includes arranging the fiber such that a first portion of the fiber is disposed on the back side of the carrier (hereinafter also referred to as the rear portion of the fiber), a second portion of the fiber protrudes from the front side of the carrier (hereinafter also referred to as the front portion of the fiber), and a third portion of the fiber is inside the carrier (also referred to as the middle portion of the fiber or the carrier portion of the fiber).

[0024] In some embodiments, the polyurethane reaction mixture includes at least one polyol, at least one isocyanate, and a curing agent. In embodiments where at least one PCM is used in the PU backing, at least one PCM is mixed into the PU reaction mixture along with other additives and an antibacterial agent. Preferably, at least one PCM in encapsulated powder form is mixed into either the polyol or isocyanate container added to the reaction mixture and is mixed immediately prior to applying the polyurethane reaction mixture to the back side of the artificial turf carrier.

[0025] In some embodiments, the polyurethane is a reaction product of a first and a second polyol with an isocyanate, the first polyol is a polyether polyol and / or a polyester polyol having at least two hydroxyl groups per unit molecule, the second polyol is polybutadiene diol, and the isocyanate includes an isocyanate monomer, an isocyanate polymer, an isocyanate prepolymer, or a mixture thereof, and the isocyanate monomer, isocyanate polymer, and isocyanate prepolymer have two or more isocyanate groups per unit molecule.

[0026] These and other features and advantages of the present invention will be better understood from the following detailed description of the invention with reference to the accompanying drawings.

Brief Description of the Drawings

[0027]

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[0028] Various embodiments of the present invention will now be described in more detail with reference to the accompanying drawings, in which like referenced elements are equivalent elements or perform the same function, and in which an element already described previously is not necessarily described in a subsequent figure, if the function is equivalent.

[0029] Referring to FIG. 1, a method for manufacturing artificial turf is provided. This method includes, in step 102, preparing a first polyurethane reaction mixture (PU-RM), where the first polyurethane reaction mixture includes a phase change material (PCM) dispersed in the polyurethane reaction mixture; in step 104, incorporating artificial turf fibers into a carrier; and in step 108, adding the PCM to the fluid (viscous) polyurethane reaction mixture on the back side of the carrier and curing the polyurethane reaction mixture to form a polyurethane backing. This method is characterized in that an effective amount of PCM is added to the polyurethane reaction mixture. The PCM is added and dispersed by being mixed within the polyurethane reaction mixture before the polyurethane reaction mixture is placed on the back side of the carrier. Once the polyurethane reaction mixture is placed on the back side of the carrier, the polyurethane reaction mixture is cured, and a solid polyurethane backing is formed in which a portion of the turf fibers protruding from the back side of the carrier is firmly embedded within the solid mass of the polyurethane backing. The polyurethane backing enhances the structural strength of the artificial turf and improves the fiber tensile properties of the turf fibers. Also, with the addition of the PCM, the artificial turf becomes equipped with passive cooling control properties (also simply referred to as cooling properties).

[0030] Preferably, since the polyurethane reaction mixture enters the carrier structure before completely solidifying, the carrier is provided with cooling properties. Depending on the structure of the carrier, the viscosity of the polyurethane reaction mixture, and the rate of solidification of the polyurethane reaction mixture, the polyurethane reaction mixture can penetrate deeper inside the carrier and enhance the cooling properties of the artificial turf. In some other embodiments, the polyurethane reaction mixture passes through the carrier before completely solidifying, and a thin coating is formed on the front side of the carrier, thereby completely covering both the back side and the front side of the carrier and filling any voids within the carrier.

[0031] The production of artificial turf fibers includes the steps of generating a polymer mixture, extruding the polymer mixture into monofilaments, quenching the monofilaments, reheating the monofilaments, and stretching the reheated monofilaments to form the monofilaments into artificial turf fibers. The generated polymer mixture further has a nucleating agent, and the polymer crystallizes inside and on the surface of the monofilaments. Artificial turf fibers are bundles of monofilaments.

[0032] For example, it may be desirable to produce artificial turf fibers or blades having a set of desired properties such as smoothness, tensile strength, resistance to shear forces, and / or resistance to splices of the fibers or blades.

[0033] In some embodiments, the artificial turf fibers are hydrophobic polyolefin fibers inserted into a carrier via a tufting process or by weaving the artificial turf fibers into the carrier.

[0034] In some embodiments, the polyurethane is a reaction product of a first and a second polyol and an isocyanate, the first polyol is a polyether polyol and / or a polyester polyol having at least two (''2'') hydroxyl groups per unit molecule, the second polyol is polybutadiene diol, and the isocyanate includes an isocyanate monomer, an isocyanate polymer, or an isocyanate prepolymer, or a mixture thereof, and the isocyanate monomer, the isocyanate polymer, and the isocyanate prepolymer have two or more isocyanate groups per unit molecule.

[0035] The polybutadiene diol is used in an amount of 0.5 to 10% by weight ratio of the combination of the first polyol and the isocyanate, more preferably in an amount of 1.0 to 9.0% by weight ratio of the combination, and most preferably in an amount of 4.0 to 8.0% by weight ratio of the combination. The number average molecular weight of the polybutadiene diol is in the range of 1000 to 6000 g / mol, more preferably in the range of 1500 to 4500 g / mol.

[0036] The polyurethane reaction mixture further contains a surfactant in an amount of 0.01% to 1.2% by weight ratio of the combination of the first and second polyols and the isocyanate, more preferably 0.8% to 1.0% by weight ratio of the combination, and most preferably 0.05% to 0.15% by weight ratio of the combination. The flowable polyurethane mass has a density exceeding 1000 g / l, preferably in the range of 1100 g / l to 1500 g / l, more preferably in the range of 1200 g / l to 1400 g / l.

[0037] The curing treatment of the flowable polyurethane mass can be carried out by heating the polyurethane reaction mixture on the back side of the carrier to a temperature of 70 to 140 °C.

[0038] Once the polyurethane backing is formed, the artificial turf is wound into a roll and stored.

[0039] The artificial turf composed of PCM is significant in that it can prevent overheating of the turf.

[0040] In certain embodiments, the isocyanate is a diisocyanate. In certain embodiments, at least two hydroxyl groups per unit molecule of the first polyol are two terminal hydroxyl groups. In certain embodiments, the polybutadiene diol is present in an amount of 0.5 to 10% by weight ratio of the combination of the first polyol (i.e., polyester polyol or polyether polyol) and the isocyanate. In some of the above embodiments, the polybutadiene diol is present in an amount of 1.0 to 9% by weight ratio of the combination, preferably in an amount of 4.0 to 8.0% by weight ratio of the combination. Significantly, with this PBD concentration, a polyurethane backing is formed, and the polyolefin fiber or blade embedded therein is strongly fixed to this polyurethane backing. In particular, when using a highly hydrophobized monofilament such as a PE monofilament, it has been observed that the so-called "stick-slip effect" occurs. The stick-slip effect represents a specific form of the relative movement of two surfaces (e.g., the PE fiber surface and the polyurethane surface surrounding the fiber), whereby the movement of the surfaces alternately repeats binding to each other and sliding over each other, and the frictional force changes accordingly. Usually, the coefficient of static friction (empirical value) between two surfaces is greater than the coefficient of kinetic friction. When the applied force is large enough to overcome the static friction, the reduction of friction to kinetic friction causes the speed of movement to suddenly increase. Usually, the stick-slip effect is considered an undesirable effect because, for example, for the relative movement between human skin and PE (polyethylene) fibers, there is a risk of injury or skin burns. However, the applicant surprisingly observed that the stick-slip effect regarding the movement of the PE / polyurethane surface is a desirable and beneficial effect because it increases the resistance of the fiber to the tuft pull-out force. The farther the fiber is pulled out from the backing, even when the tensile force is sufficiently large, due to the stick-slip effect, the fiber stops again, whereby the coefficient of static friction rather than the coefficient of kinetic friction comes into play.

[0041] As used in this application, the "back side" of a carrier is the side opposite to the side where most of the fibers or blades extend.

[0042] The term "tufting" as used in this application refers to a method of incorporating fibers into an existing carrier. Short U-shaped loops of fibers or blades are introduced through the carrier from one side. Their endpoints are on the outside of the carrier in another direction. Usually, the tuft yarn forms a regular array of "dots" on the opposite side. On the side of the carrier where the U-shaped loops are placed, the tuft fibers or blades are tied for safety, but this is not always necessary. Subsequently, the ends of the tuft yarn are frayed or otherwise processed as needed, and then a dense layer of fibers or blades protruding from the carrier is formed.

[0043] The term "weaving" as used in this application is a method of incorporating artificial turf fibers (monofilaments or bundles of monofilaments) into an existing carrier, whereby the artificial turf fibers and the fibers constituting the carrier are woven together. The woven fibers or blades and meshes form a fabric-like structure or a cloth-like structure. When artificial tuft fibers are incorporated by weaving, the fibers are woven together with at least three series of mesh fibers or blades. Thus, when the fibers are incorporated by weaving rather than tufting, a higher proportion of the artificial turf fibers are woven into the carrier material. This can improve the resistance of the artificial turf to wear and tearing.

[0044] In certain embodiments, the method further comprises the step of adding a catalyst to a polyol or isocyanate or a reaction mixture containing these.

[0045] In one embodiment, the fluid polyurethane mass has a density greater than 1000 g / l, preferably a density in the range of 1100 g / l to 1500 g / l, more preferably a density in the range of 1200 g / l to 1400 g / l. The first polyol and / or catalyst may be selected such that the density of the resulting polyurethane reaction mixture is at least one of the specified density ranges. In said density range, it has been observed that a polyurethane artificial turf backing is provided that can be easily laid without bulging and is elastic and robust against various tensile, pressing, and shear forces.

[0046] In some embodiments, the liquid polyurethane reaction mixture is a non-foamed polyurethane, i.e., a (substantially) non-porous polyurethane. The foams and fluids in this high-density range are often highly viscous and often do not suitably wet fibers or blades, especially monofilaments within a monofilament bundle. However, by using a more hydrophobic polyurethane form and, if necessary, further containing a wetting agent, the PE filaments can be firmly fixed by van der Waals forces using the polyurethane reaction mixture having the aforementioned high density. Thus, in embodiments of the present invention, hydrophobic fibers or blades can also be firmly fixed to the high-density polyurethane backing.

[0047] In one embodiment, the step of incorporating the artificial turf fibers into the carrier includes the step of tufting the artificial turf fibers onto the carrier. In another embodiment, the step of incorporating the artificial turf fibers into the carrier includes the step of weaving the artificial turf fibers into the carrier.

[0048] In one embodiment, the artificial turf fibers are a bundle of monofilaments. In this context, it is particularly significant to use a more hydrophobic polyurethane version, optionally in combination with a wetting agent. This is because standard polyurethane foams and fluids are usually unable to wet the monofilaments disposed inside the monofilament bundle. Also, by wetting the monofilaments inside the bundle, the mechanical fixation is greatly enhanced.

[0049] In one embodiment, the artificial turf fibers are hydrophobic polyolefin fibers, such as polyethylene (PE) fibers, polypropylene (PP) fibers, polybutylene fibers, or fibers made of a polymer blend containing hydrophobic polyolefin as a main component.

[0050] Depending on the embodiment, the curing process may be carried out passively, for example, by incubating a liquid polyurethane reaction mixture installed and dispersed on the back side of the carrier at room temperature, or by heating the polyurethane backing to a temperature significantly higher than room temperature for a given time.

[0051] In some embodiments, the curing treatment of the fluid polyurethane mass includes heating the polyurethane mass installed and dispersed on the back side of the carrier to a temperature of 70 to 140 °C. For example, the heat is applied for 1 to 5 minutes, preferably 2 to 3 minutes.

[0052] The hardening process, also referred to as the "curing" process, is carried out such that the polyurethane reaction mixture cures and develops its strength. The hardening (or curing) treatment includes reacting an NCO-terminated diisocyanate with a hydroxyl-terminated polyol. The hardened polyurethane reaction mixture of the backing firmly surrounds the portion of the fiber or blade incorporated into the fluid polyurethane mass.

[0053] Figure 2 shows a flowchart of a method for manufacturing artificial turf having a PCM polyurethane backing and a heat conduction layer on the back side of the PCM polyurethane backing according to another embodiment of the present invention. This method has the bed of steps 102 to 108 of FIG. 1, collectively referred to as step 110. The method further has a step of preparing a polyurethane reaction mixture containing a heat conductive material (HCM) in step 112. In step 114, the polyurethane reaction mixture having the heat conductive material is placed on the back side of the first polyurethane backing, and in step 116, the polyurethane is cured to form a second polyurethane having the heat conductive material, also referred to herein as the heat conductive polyurethane backing or the heat conduction layer. The heat conductive material may include graphite, graphene, or a combination thereof to improve the heat conductivity between the substrate and the top layer. It has been understood that the combination of the heat conduction layer and the PCM in the backing layer of the turf structure is particularly significant in preventing the surface of the paving structure from overheating.

[0054] Figure 3 shows a flowchart of a method for manufacturing artificial turf having two PCM layers formed on the upper side of a carrier material and a thermally conductive material formed on the back side of a PU backing according to yet another embodiment of the present invention. In this embodiment, the PCM is not added to the PU backing. Instead, the PCM is added to two coating layers formed on the upper side of the carrier. According to Figure 3, the method includes, in operation 118, forming a first and a second coating layer on the upper side of the carrier; in operation 112, incorporating turf fibers onto the carrier; forming a first PU backing PCM on the back side of the carrier; and in operation 114, forming a second PU backing having an HCM on the back side of the first PU backing. In the embodiment of Figure 3, it is described that two PCM layers are formed, but it should be noted that in a variation of this embodiment, only one PCM layer may be formed. Forming two PCM layers can be significant. This is because it facilitates the installation of additional PCM and because different PCMs can be used in each of the two coatings having different melting points. Thus, the two PCM layers may be the same or different. Also, in another variation of the embodiment of Figure 3, the step of forming a second PU backing having a thermally conductive material may be omitted.

[0055] Figure 4 shows a plurality of tanks and mixers including extracts for producing a polyurethane reaction mixture according to an example. A first mixing unit 201 (also referred to as a first tank or a first container) is used to produce a first mixture 202 including a polyether polyol or a polyester polyol. For example, the first mixture 202 has a polyether-polyol and includes, for example, a polyether-polyol having a number average molecular weight of about 4000 g / mol, for example, a polyol based on polymerized propylene oxide. The polyether polyol may be obtained, for example, in the form of an existing polyol.

[0056] If necessary, the first mixture 202 includes a filler material. Adding a filler reduces costs and / or helps achieve a particular appearance or weight. The filler can be selected from the group of, for example, ground limestone, precipitated calcium carbonate, clay, coal fly ash, silicates, and other inert materials including non-reactive liquids. Further, aluminum hydroxide (Al(OH) 3 ) or ammonium polyphosphate (NH 4 PO 3 ) n (OH) 2 ) such fillers having a flame retardant and / or swelling effect, or a mixture of the aforementioned fillers can be used.

[0057] Furthermore, the first mixture 202 may include a catalyst that promotes the polyaddition reaction to produce polyurethane. The catalyst may be, for example, an amine compound and a metal-organic complex. Common amine catalysts are tertiary amines such as triethylenediamine (TEDA, 1,4-diazabicyclo[2.2.2]octane or DABCO), dimethylcyclohexylamine (DMCHA), and dimethylethanolamine (DMEA). Metal-organic complexes used as polyurethane catalysts may be based on, for example, mercury (e.g., mercury carboxylate), lead, tin (e.g., alkyltin carboxylate and oxide), bismuth, and zinc (e.g., bismuth and zinc carboxylate). Next, the first mixture is stored in a first tank 201, for example, a day tank, i.e., a tank sized to provide a day's worth of use.

[0058] Preferably, a mixture of an organotin compound and an amine catalyst is used. Suitable amines include, for example, cyclohexyldimethylamine, 2-dimethylaminoethanol, 4-ethylmorpholine, N,N,4-trimethylpiperazine-1-ethylamine, 1,4-dimethylpiperazine, 3-aminopropyldimethylamine, 2,2’-iminodiethanol, 1-methylimidazole, 1,2-dimethylimidazole, 2-[[2-(dimethylamino)ethyl]methylamino]ethanol, N-[3-(dimethylamino)propyl]-N,N’,N’-trimethylpropane-1,3-diamine, formic acid, a compound (2:1) with 2,2’-oxybis[N,N-dimethylethylamine], 1,1’-[[3-(dimethylamino)propyl]imino]bispropan-2-ol, +2-[(2-[2-(dimethylamino)ethoxy]ethyl)methylamino]ethanol, benzyldimethylamine 4-methylmorpholine, N,N,N’,N’-tetramethylhexamethylenediamine, 2-[2-(dimethylamino)ethoxy]ethanol, 1,4-diazabicyclooctane, bis(2-dimethylaminoethyl)amine, N,N,N’,N’-tetramethyl-2,2’-oxybis(ethylamine, 2,2’-dimorpholinylethyl ether, 1,8-diazabicyclo[5.4.0]undec-7-ene (7-undecene), N’-[3-(dimethylamino)propyl]-N,N-dimethylpropane-1,3-diamine, N,N,N’,N’,N”,N”-hexamethyl-1,3,5-triazine-1,3,5(2H,4H,6H)-tripropanamine, and N,N-bis[3-(dimethylamino)propyl]-N’,N’-dimethylpropane-1,3-diamine.

[0059] The second mixture 204, i.e., the isocyanate monomer / polymer / prepolymer mixture, e.g., MDI, is preferably stored in a second tank 203, which is preferably a day tank. Usually, another container 205, which is smaller in size than the first and second tanks, contains a third substance mixture 206 containing PCM. In the embodiment of FIG. 3, no PCM is added to the tank 205.

[0060] In the embodiment shown in FIG. 4, PBD is also added to the third substance mixture 206, but it is understood that in other embodiments, PBD is not added.

[0061] If necessary, other substances such as antibacterial agents, wetting agents, pearlescent oils and / or one or more additional additives may be added. One or more additional additives can be, for example, flame retardants, pigments, extenders, crosslinking agents, foaming agents, etc. Containers 201, 203, and 205 may be part of blender 208 or coupled to blender 210. Blender 208 receives the first mixture 202 from the first container 201, the second mixture 204 from the second container 203, and PBD, PCM, and one or more optional substances (wetting agent, pearlescent oil, and / or additional additives) from the third container 205. Blender 208 blends the first, second, and third mixtures received from their respective tanks in amounts suitable for the production of the polyurethane reaction mixture 210. The substance concentrations are within the ranges specified in the embodiments of the present invention. For example, the first, second, and third mixtures are blended such that the number of OH groups in the first polyol molecules in the first mixture combined with the number of OH groups in the PBD molecules in the third mixture is approximately corresponding to the number of NCO groups in the isocyanate molecules (monomers and prepolymers) (for example, in the range of ratios in the range of "0.9:1" to "1:0.9"). The third mixture 206 is added to the reaction mixture 210 by blender 208 in an amount such that the amount of PCM in the reaction mixture is in the concentration range of 5.0 to 12.5% by weight relative to the total weight of the PU reaction mixture.

[0062] Blender 208 may be a low-pressure gear pump that produces the desired mixing ratios of the first, second, and third mixtures. The ratios and material distribution are driven by a computer-aided device. Regardless of the viscosity of the polyurethane reaction mixture 210, the polyurethane reaction mixture penetrates deeply into the turf tufts of artificial turf and wets the textile carrier and the monofilaments contained therein.

[0063] The polyurethane reaction mixture 210 produced by the blender 208 is discharged into a container 212 which may be in the form of a hose. The chamber 212 has an opening 214 leading to a coater, for example a "knife over roll" backing assembly, as shown in FIG. 5 for example. Usually, the reaction mixture discharged by the blender 208 reaches the opening 214 which is part of the backing assembly within 30 seconds. At this point, the polyaddition reaction which results in the production of the liquid polyurethane reaction mixture used for backing the artificial turf carrier textile has already almost been completed. However, some reactions may still continue during the backing process.

[0064] In certain embodiments, the first polyol, (PBD if necessary) and the isocyanate together constitute at least 25% of the total amount of the entire reaction mixture used to produce the liquid polyurethane reaction mixture which is used as artificial turf backing after the curing process, at least 40% in some other embodiments, or even more than 95%. In one example, the reaction mixture comprises, by weight, about 21.5% isocyanate, 0.5% PBD, 21.5% first polyol, 2.1% catalyst, 10% PCM, 2.5% additives such as oil, pigment or flame retardant, and the remaining filler material.

[0065] In another specific example, the reaction mixture comprises about 20% isocyanate, 0.1% PBD, 20% first polyol, 2.1% catalyst, 7.5% PCM, 2.0% additives such as oil, pigment or flame retardant, and the remaining filler material.

[0066] In a preferred embodiment, the liquid polyurethane reaction mixture is a non-foamed polyurethane, i.e. a (substantially) non-porous polyurethane.

[0067] Figure 5 shows the "knife over roll" polyurethane backing process and the corresponding backing assembly. A liquid, viscous reaction mixture 210, also referred to as a liquid polyurethane reaction mixture, exits the opening 214 of the container 212 and is placed onto the carrier 308. A plurality of artificial turf fibers or blades 501 project from the front side of the carrier. The liquid polyurethane reaction mixture 210 is placed on the back side of the carrier. The polyurethane reaction mixture is continuously placed while the carrier 308 is moved in the direction indicated by the arrow by the roll 306. The "knife" 304 shown in the cross-sectional view is disposed at a defined distance above the carrier 308, and the viscous polyurethane reaction mixture 210 passing through the space between the knife 304 and the carrier 308 is caused to have a defined thickness.

[0068] The high viscosity of the polyurethane reaction mixture according to the present invention, the configuration and dimensions of the opening 214, and the velocity of the polyurethane reaction mixture flowing through this opening are selected such that a regulated amount of the polyurethane reaction mixture is built up and accumulated in front of the knife 304. Thereby, the thickness of the polyurethane backing of the piece on which the artificial turf is produced can be reliably made constant.

[0069] After the polyurethane reaction mixture 210 has been uniformly placed on the back side of the carrier 308, the coated artificial turf piece is held at room temperature for about 10 minutes, whereby it is cured (the viscosity increases). Usually, the polyurethane backing becomes solid 30 minutes after being placed on the carrier.

[0070] Preferably, in order to accelerate the curing, once the polyurethane reaction mixture has been placed on the back side of the artificial turf, the artificial turf is exposed to a high temperature of about 100 °C. Usually, after 90 seconds at the high temperature, 90 to 95% of the polyurethane reaction mixture is "cured" (becomes solid). The heating may be carried out, for example, in an oven. For example, the backing assembly may automatically transport the coated artificial turf piece into the oven.

[0071] Figure 6 shows a liquid polymer mixture 400 in the production of monofilaments 412 in an extrusion process. The polymer is a polyolefin, for example a polyethylene mixture. The polymer mixture 400 includes additives 404, 406 such as UV stabilizers, pigments, flame retardants. A screw, piston, or other device is used to pass the polymer mixture 400 through the holes 410 in the plate 408. Thereby, the polymer mixture 400 is extruded into the monofilament 412.

[0072] In some embodiments, the polymer mixture may include more rigid polymer beads, such as polyamide polymer beads. Due to the hydrodynamics during the extrusion process, the beads tend to concentrate in the center of the monofilament 412. This leads to the concentration of a rigid filamentous PA region in the core region of the monofilament, while the surface of the monofilament is composed almost entirely of hydrophobic PE. Thus, a fiber with improved elasticity is provided, which has a soft PE surface that protects against wounds and skin burns, while having a highly hydrophobic surface and can thus be easily peeled off from a polar polyurethane backing.

[0073] Thus, the monofilament is produced by supplying the polymer mixture 400 to a fiber production extrusion line. The molten mixture passes through an extrusion tool, i.e., a spinneret plate or a wide slot nozzle, the flow of the melt is shaped into filament or tape form, quenched or cooled in a spinning water bath, and dried and drawn by passing through rotating heated godets and / or a heating oven having different rotational speeds. The monofilament or fiber may be annealed online in a second step by passing through a further set of heating ovens and / or heated godets.

[0074] In one embodiment, step 412 of manufacturing artificial turf fibers (which may include one or more monofilaments) includes the step of forming the drawn monofilament into a thread. A plurality of, for example, 4 to 8 monofilaments can be formed or finished into a yarn.

[0075] In one embodiment, the extrusion process is carried out at a pressure between 40 and 140 bar, more preferably between 60 and 100 bar. The polymer mixture may be formed by adding polymer granules to a solid polymer composition, mixing the same, and heating it until all the polymers are melted. For example, the polymer mixture may be heated to reach a temperature of 190 to 260°C, more preferably 210 to 250°C, at the timing of extrusion.

[0076] In one embodiment, the stretching process includes the step of stretching the reheated monofilament according to a stretching coefficient in the range of 1.1 to 8, more preferably in the range of 3 to 7.

[0077] In one embodiment, the quenching process is carried out in a quenching solution having a temperature between 10 and 60°C, more preferably between 25°C and 45°C.

[0078] In one embodiment, the process of incorporating artificial turf fibers into a carrier includes the step of tufting or weaving the artificial turf fibers into the carrier.

[0079] In one embodiment, the quenching solution, such as a water bath, has a temperature between 10 and 60°C, more preferably between 25°C and 45°C, even more preferably between 32°C and 40°C (the temperature immediately after the extrusion nozzle or hole).

[0080] In one embodiment, the extrusion process is carried out at a pressure of 80 bar, the polymer mixture at the time of extrusion has a temperature of 230°C, the stretching coefficient is 5, and the quenching solution, such as a water bath, has a temperature of 35°C.

[0081] Referring to FIGS. 7a and 7b, the step of incorporating the turf fiber 501 into the carrier 308 includes arranging the fiber 302 such that a first portion of the fiber 501 protrudes to the front side of the carrier (hereinafter also referred to as the front portion of the fiber), a second portion 506 of the fiber is disposed on the rear side of the carrier (hereinafter also referred to as the rear portion of the fiber), and a third portion of the fiber 504 is inside the carrier (also referred to as the middle portion of the fiber).

[0082] FIG. 7a shows how the backing of artificial turf fibers and a plurality of artificial turf fibers or blades can be arranged on a carrier 308, such as a textile plane, by tufting. The carrier 308 may be a textile made of a hydrophobic polymer, such as PE. Tufting is a type of textile fabric in which artificial tuft fibers 501 (which may be a monofilament 412 or a bundle of monofilaments) are inserted into the carrier 308.

[0083] As used herein, a "monofilament" is a filament produced by extruding a liquid polymer mixture through a single orifice, or a slice of a polymer tape produced by slit film technology.

[0084] As shown in FIG. 5a, after the insertion, the short U-shaped loop of the fiber faces the outside of the surface of the carrier. Next, one or more blade cuts 502 cut the loop. As a result of the cutting step, two artificial turf fiber ends per unit loop and monofilament face outward from the carrier, and a turf-like artificial turf surface is generated as shown in FIG. 5b. Thereby, the first portion 506 of the monofilament inserted into the carrier 308 (corresponding to the first portion of the artificial turf fiber or blade) is exposed on the bottom side (back side) of the carrier, and the second portion 302 of the monofilament is exposed on the upper side of the carrier. A part 504 of the monofilament / fiber or blade is disposed within the carrier. The fiber or fiber bundle may protrude as a loop 503 outside the back side of the carrier. The artificial turf piece generated in the tufting process may be sent to the backing assembly shown in FIG. 3 for placing the polyurethane reaction mixture 210 on the back side of the carrier.

[0085] FIGS. 8a and 8b show a monofilament and a portion of a fiber or blade embedded in a polyurethane backing. Reference numeral 600 represents the total thickness of a piece of artificial turf coated with the polyurethane reaction mixture 210 produced according to an embodiment of the present invention.

[0086] Figure 8a shows a piece of artificial turf having a closed mesh carrier 810 composed of a highly viscous polyurethane reaction mixture and / or where the polyurethane reaction mixture penetrates the carrier 308 and is prevented from passing beyond the carrier 308. In this embodiment, the second portion 302 of the fiber or blade 501 projects from the carrier 308 to the front side of the artificial turf and is not embedded in the polyurethane film. This is because the liquid polyurethane reaction mixture 210 cannot reach the front side of the carrier during the backing process. Also, in this embodiment, the fiber portion 504 within the carrier is not wetted by the polyurethane reaction mixture. However, the back side portion 506 of the fiber or blade is embedded in the liquid polyurethane reaction mixture 210 during the backing process. Although the length of these rear side portions is relatively small, due to the high hydrophobicity and improved wettability of the fiber or blade by the polyurethane reaction mixture 210, the fiber or blade is firmly fixed within the backing by van der Waals forces, and the slip-stick effect ensures that the fiber or blade is further protected from tuft pull-out forces. Figure 8b shows a piece of artificial turf composed of a lower viscosity polyurethane reaction mixture and / or having a carrier 308 with a coarse mesh (compared to the embodiment of Figure 6a). The carrier may be a textile mesh or another type of material, and the polyurethane reaction mixture 210 includes perforations that allow it to enter the carrier and reach the front side of the artificial turf. Accordingly, the front portion 302 of the fiber or blade in Figure 6b has an outer portion 604 that is not embedded in the polyurethane film 210 and an inner portion 602 that is embedded in the polyurethane film 210.2 that has entered the carrier. Also, portions 504 and 506 are wetted by the liquid polyurethane reaction mixture 210 and are embedded in the liquid polyurethane reaction mixture 210. Accordingly, the carrier, the portion of the fiber or blade inserted into the carrier, and another portion 602 of the fiber or blade on the front side of the carrier may also be in a state of being embedded in the polyurethane backing in addition to the rear side portion 506 of the carrier.The present embodiment of FIG. 6B is significant in that the PCM-containing PU backing is applied to both the back side and the front side of the carrier, and as a result, cooling protection is provided to the entire artificial turf structure except for the outer portion 604 of the fiber or blade.

[0087] The liquid polyurethane reaction mixture 210 applied to the back side of the carrier in the backing process surrounds at least a part of the monofilaments of the artificial turf fibers or blades arranged, thereby mechanically fixing them. Then, the liquid polyurethane mixture 210 is solidified into the polyurethane artificial turf green backing 210' at room temperature or in an oven. The solid film functions as the backing of the artificial turf. In some examples, an additional backing layer may be added to the bottom of the artificial turf backing.

[0088] Referring to FIG. 9, a diagram of the artificial turf structure obtained by the method of FIG. 2 is shown. This structure is similar to the structure of FIG. 8a, but further has a second PU backing 318, which contains a heat-conductive material (HCM) such as graphite, graphene, or a combination of the two.

[0089] FIG. 10 is a diagram of the artificial turf structure obtained by the method of FIG. 3. This structure further includes a PCM coating 312 formed on the carrier 308. The PCM coating 312 may be a single layer of coating installed in a single operation, or a double layer of coatings sequentially installed on the carrier 308. In this embodiment, the PU backing 211 is formed as described above with respect to the backing 210', but no PCM is added. The turf structure of the embodiment of FIG. 10 further has a heat-conductive layer 318, which may be configured as described above for the embodiment of FIG. 9.

[0090] FIG. 11 shows a modification of the embodiment of FIG. 10. There is no heat-conductive layer 318 formed under the PU backing 211. Therefore, the structure of FIG. 11 is the same as the structure of FIG. 10 except that there is no heat-conductive layer 318.

[0091] Referring to FIG. 12, in some embodiments, the PCM coating 312 of the embodiments of FIGS. 10 and 11 has first and second PCM layers 312a, 312b, each of which may have at least one PCM for passive control of the temperature of the turf structure. Also, the turf structure may include a heat conduction layer 318 as shown in the embodiment of FIG. 10. The heat conduction layer 318 may be adjacent to the substrate of the turf attachment member for effective transfer of heat to and from the ground and the PCM layers.

[0092] The first and second PCM layers 312a, 312b may function to control the temperature of the turf structure and to seal the turf structure to prevent rain from penetrating into the interior of the turf structure. Also, in some embodiments, the first and second PCM layers may function as a cushion and / or a coloring coating. Any suitable cushion material and / or coloring material may be used.

[0093] Referring now to FIGS. 13 through 15, one embodiment is shown, where the filling material 151 is formed to contain a PCM shell layer 143 around filler particles 141 (also referred to as filling particles) according to operation 131. The filling material 151 is further formed to include a thermally conductive shell layer 145 in which graphite or graphene (G) is dispersed according to operation 133. The filling particles may be of any suitable type or size, such as, for example, rubber or other polymer particles or fragments, olive seeds, cherry seeds, or bio-based material particles or fragments.

[0094] The filling material 151 may be disposed on the carrier 308 of the turf structure as shown in FIG. 15. In some embodiments, first and second PCM shell layers (not shown) may be formed over the filler particles.

[0095] The PCM may include at least one PCM, preferably at least two PCMs, and most preferably at least three PCMs. When at least two PCMs or at least three PCMs are used, the PCMs may be selected to have different melting points within a desired range to provide improved temperature control of the turf structure.

[0096] The first and second PCM layers 312a, 312b of FIG. 12 or the PCM shell layer 143 of FIG. 14 may contain, by weight ratio, from 4.0 to 10.0 wt%, particularly from 5.0 to 9.0 wt%, and further from 6.0 to 8.0 wt%, based on the total weight of each PCM layer on a wet basis. On a dry basis, i.e., after application and drying of any water (or solvent), each respective PCM layer may contain, by weight ratio, from 5.0 to 12.5 wt%, particularly from 6.0 to 10.0 wt%, and further from 7.0 to 9.0 wt%, based on the total weight of each PCM layer.

[0097] In some embodiments, the PCM in each of the first and second PCM layers 312a, 312b, or the PCM in the PCM shell layer 143 may be, on a wet basis, from 6.5 to 7.5 wt% by weight ratio based on the total weight of each PCM layer, or from 7.5 to 8.5 wt% by weight ratio on a dry basis.

[0098] Each of the first and second PCM layers 312a, 312b, and the PCM shell layer 143 may be a layer based on an acrylic latex layer, a styrolbutadiene (also known as styrene butadiene) layer, or a combination of an acrylic latex and a carboxylated styrolbutadiene. Each of the first and second PCM layers 312a, 312b, and the PCM shell layer 143 may have a significant proportion (e.g., more than 40% or more than 60% of its weight) of a filler material such as sand and / or chalk to improve surface roughness and grip.

[0099] Each of the first and second PCM layers 312a, 312b, and / or the PCM shell layer 143 may have a thickness (also referred to as thickness) of from 100 μm to 400 μm, particularly from 200 μm to 300 μm, more specifically from 225 μm to 275 μm. In some embodiments, the first and second PCM layers may each have a thickness of 250 μm. Thus, when two PCM layers 312a, 312b are used, the total thickness of the combined PCM layers may be from 200 μm to 800 μm, particularly from 400 μm to 600 μm, more specifically from 450 μm to 550 μm.

[0100] It is understood that two PCM shell layers 151 may be formed on top of each other on the filler particles 142 before forming the thermal conductive shell layer 145. In the case of two PCM shell layers, they may be the same. However, in some embodiments, the two PCM shell layers may contain the same PCM, but the amount of PCM in the second PCM shell layer may be a different amount that is higher (or more) than the amount of PCM in the first PCM shell layer. For example, the amount of PCM in the first PCM shell layer may be at least 5.0 wt%, particularly 10 to 30 wt%, particularly 10 to 25 wt% less than the amount of PCM in the second PCM shell layer. The amount of PCM in the first PCM layer represents the weight of the PCM relative to the weight of the total material of the first PCM shell layer. The amount of PCM in the second PCM shell layer represents the weight of the PCM relative to the weight of the total material of the second PCM shell layer. Preferably, the first PCM shell layer may be attached to the particles 141, and the second PCM shell layer may be attached to the first PCM shell layer.

[0101] By decreasing the PCM content from the highest amount in the outermost second PCM shell layer towards the innermost layer of the innermost first PCM shell layer, the utilization rate of the PCM used to remove heat when the temperature rises to the melting point of the PCM can be improved, while preventing the temperature of the turf fibers or blades from rising above the desired temperature range. This can also be significant in that when the temperature drops, it returns the PCM to its solid phase, thereby releasing heat and preventing the temperature of the turf structure from dropping significantly. Therefore, this configuration with a PCM gradient between the two layers can be particularly significant in controlling the temperature of the outdoor turf structure of a sports coat or stadium within the desired temperature range.

[0102] In some embodiments, the first and second PCM shell layers may each include a first PCM and a second PCM, and the first and second PCMs may be different and may have different melting points. For example, the first PCM and the second PCM or multiple PCMs may be selected to have different melting points. The first PCM in the first PCM shell layer may have a lower melting point.

[0103] In some embodiments, the first and second PCM layers 312a, 312b, and / or the first and second PCM shell layers may each include two PCMs, and in each layer, the total amounts of the two PCMs may be different, and the total amount of the two PCMs may be less in the first layer than in the second layer.

[0104] In some embodiments, the first and second PCM layers 312a, 312b, and / or the first and second PCM shell layers may each include three PCMs, and the total amounts of the three PCMs in each layer may be different, and the total amount of the three PCMs may be less in the first layer than in the second layer.

[0105] By using multiple layers of the PCM layer, the amount of PCM and sand added to the paving structure can be increased, and thus the cooling characteristics, surface roughness, grip, and robustness of the paving structure can be increased. Also, the type of PCM and their melting points in each layer may be varied, thereby further improving the temperature control of the turf structure.

[0106] The heat conduction layer 318 (FIG. 10) and / or 508 (FIG. 9) and / or the heat conductive shell layer 145 may include a heat conductive material. The heat conductive material may preferably be graphite, graphene, or a combination thereof. In some embodiments, the graphite may be nanographite. The heat conduction layer 318 or 508 may be disposed between the PU backing layers 211, 210' and a substrate (not shown). Also, the heat conduction layer 318 or 508 may be adapted to improve the bonding of the multi-layer PCM turf structure to the substrate.

[0107] The amount of graphene, graphite, or a combination of graphene and graphite in the heat conduction layer 318 and / or 508, and / or the heat conductive shell layer may be, on a wet basis, by weight ratio, 4.0 to 20%, particularly 6.0 to 14.0%, and further 8.0 to 12.0% with respect to the total mass of each layer. The amount of graphene or graphite or a combination of graphene and graphite in the heat conduction layer 318 and / or 508, and / or the heat conductive shell layer may be, on a dry basis, by weight ratio, 6.0 to 24%, particularly 7.0 to 17.0%, and further 10.0 to 14.0% with respect to the total weight of each layer.

[0108] In some embodiments, the graphene, graphite or combination of graphene and graphite in the thermal conduction layer 318 and / or 508, and / or the thermal conduction shell layer 145 may be 11.0 to 12.0% by weight based on the total weight of each layer on a dry basis. In some embodiments, the thermally conductive material may include nanographite. It has been observed that the thermal conductivity gradually increases with the content of nanographite.

[0109] In certain embodiments, the thermal conduction layer and / or the thermal conduction shell layer is at least one coating layer of a synthetic resin mixed with a thermally conductive material. In some embodiments, the thermal conduction layer and / or the thermally conductive shell layer may be a polyurethane layer in which the thermally conductive material is uniformly dispersed. The synthetic resin may be a polymer of an acrylic resin or an epoxy resin.

[0110] In the thermal conduction layer 318, the graphene and / or graphite may be uniformly mixed with a main material, such as an acrylic primer material. The thermal conduction layer 318 improves the heat transfer between the PCM layers 312a, 312b and the substrate. Also, the thermal conduction layer 318 may seal any cracks in the substrate and fill them. Also, in some embodiments, the thermal conduction layer 318 may function as a filler layer adapted to fill gaps in the substrate and thus be sufficiently fluid at ambient temperature to pass through the interior of any gaps or pores in the substrate. The filler may include, for example, any suitable acrylic-based filler or epoxy-based filler. Thus, the filler layer is used to smooth a rough substrate. An example of a rough substrate is aged asphalt that has lost some of its aggregate. In some embodiments, the filler may be composed of acrylic or SBR latex, mineral filler, rheology modifier, pigment, water.

[0111] In the illustrated embodiments, only one or two PCM layers and / or PCM shell layers are shown, but in some embodiments, three or more PCM layers may be used without departing from the scope of the present invention. By using multiple PCM layers, the amount of PCM can be decreased more stepwise in the direction from the outermost PCM layer to the innermost PCM layer, and thus, the overall utilization and effectiveness of the PCM used to maintain the turf structure within the desired temperature range can be further improved even in extremely hot / warm climates or freezing climates.

[0112] The substrate 10 (see FIG. 12) may be, for example, concrete, asphalt, a composite material of asphalt, or a composite material, a layer of gravel and / or stone, a flattened ground, etc.

[0113] A suitable PCM may be encapsulated inside microcapsules having walls made of a polymer resin. For example, the walls of the microcapsules may be composed of melamine resin, or urea resin, or modified urea resin, or any combination thereof. An example of a suitable PCM includes a PCM-based paraffin. For example, the PCM may contain 50 to 65 wt% paraffin wax and 20 to 30 wt% water by weight on a wet basis, and the balance may be a resin forming the walls of the microcapsules and macro-capsules. On a dry basis, the water content may be close to about 3%. By changing the specific type of paraffin wax, the melting point of the PCM may be changed. The paraffin-based PCM may be encapsulated within a polymer wall composed of a polymer resin such as, for example, melamine resin and modified urea resin. For example, in the case of encapsulated PCM, the amount of melamine resin may be 5 to 15% by weight based on the total weight of the PCM, and the amount of modified urea resin may be 0 to 10%.

[0114] In some embodiments, the PCM is incorporated within a secondary support structure of hydrophilic silica powder, and the PCM may be maintained as a solid in its macro form. When the PCM structure is exposed to heat on a hot day, the PCM bonded to the secondary silica support structure melts, thus a large amount of heat is stored and the floor surface is maintained at a low temperature. At night, or when the ambient temperature drops, the PCM solidifies, thus releasing the latent heat associated with the phase change process.

[0115] In some embodiments, the PCM may be incorporated within the interior of microcapsules and used as is by being mixed within the interior of the PCM layer material.

[0116] In some embodiments, the PCM microcapsules may be housed within larger capsules, referred to as macro-capsules. Each macro-capsule may have a plurality of micro-capsules. Macro-capsules may be easier to process. The manufacture of macro-capsules is disclosed in U.S. Patent No. 6,835,334 to Davis et al., which includes the steps of providing a plurality of micro-capsules containing a PCM, and suspending the plurality of micro-capsules in a gelling agent solution, thereby forming a suspension of micro-capsules in the gelling agent. Next, the suspension is dropwise added into a cross-linking solution, the gelling agent cross-links, and discrete macro-capsules are formed. The formed macro-capsules are separated and dried until the moisture content is less than 1%, and the PCM macro-capsules are manufactured. Any suitable gelling agent may be used, including, for example, polysaccharides, non-ionic polymers, inorganic polymers, polyanions, and polycations.

[0117] Examples of polysaccharides include alginates and natural ionic polysaccharides such as chitosan, gellan gum, xanthan gum, hyaluronic acid, heparin, pectin, and carrageenan. Examples of suitable ion-crosslinkable polyanions include polyacrylic acid and polymethacrylic acid. Also suitable are ion-crosslinkable polycations such as polyethyleneimine and polylysine. A specific example of a nonionic polymer is polyvinyl alcohol. Sodium silicate is an example of a beneficial inorganic polymer. The crosslinking solution may generally contain any suitable material capable of crosslinking a gelling agent to form a crosslinked gelling agent. Common crosslinking materials include polyvalent ions, in particular cations such as, for example, magnesium, calcium, zinc, barium, strontium, aluminum, iron, manganese, nickel, cobalt, copper, cadmium, lead, or any mixture of two or more thereof. The crosslinking agent may be used in an amount sufficient to crosslink the gelling agent, as is known in the art.

[0118] The macrocapsules are mixed with a carrier material that forms the bulk of the PCM structure to form a PCM mixture, which may then be placed on top of the thermally conductive sublayer to form a PCM layer. In the case of the two-layer PCM structure shown in FIG. 11, the PCM mixture may be placed twice. The two-step placement process for forming the first and second PCM layers 312a and 312b is significant because it allows an effective amount of PCM to be added and enables easier processing. It also allows the amount and type of PCM in each layer, as well as the carrier material composition, to be varied. For example, when constructing the first PCM layer 312a, the carrier material may be formulated to provide specific cushioning properties to the turf structure, while when constructing the second PCM layer 312b, the carrier material may be selected to provide the desired color and surface hardness to the floor coating.

[0119] Due to coating thickness and application limitations, the macro capsules may have a particle size in the range of 200 to 800 micrometers (μm). Preferably 200 to 400 micrometers, more preferably 200 to 400 micrometers. The macro capsules may have a PCM content of at least 50%, preferably at least 60%, more preferably 70% by weight.

[0120] The size of the microcapsules may be in the range of 1 to 100 micrometers, preferably 1 to 80 micrometers, more preferably 10 micrometers to 50 micrometers. The microcapsules may have a relatively high amount of PCM, preferably at least 80% by weight of PCM.

[0121] Suitable PCMs include paraffinic hydrocarbons having 13 to 28 carbon atoms. The melting point of the homologous series of paraffin hydrocarbons is directly related to the number of carbon atoms. Other suitable PCMs may include straight or branched chain hydrocarbon acids such as 2,2-dimethyl 1,3-propanediol, 2-hydroxymethyl-2-methyl-1,3-propanediol, eicosanoic acid, and esters such as methyl palmitate, and crystalline materials such as aliphatic alcohols. Other suitable PCMs include encapsulated PCMs in the form of a white powder, commercially available under the trade name NEXTEK from Microtek Laboratories, having an average particle size of 15 to 30 μm and the following melting points.

[0122]

Table 1

[0123] (Example) (Example 1) The turf structure according to FIG. 4 has a concrete base material, and the concrete base material is composed of first and second PCM layers 312a and 312b having the same type and the same amount of PCM (PCM_1, PCM_2) according to the following wet-based composition.

[0124]

Table 2

[0125]

Table 3

[0126] The heat conduction layer contained about 60% PU prepolymer, about 22% solvent naphtha (a mixture of light aromatic hydrocarbons obtained from coal tar or petroleum), about 8% propylene glycol methyl ether acetate (PGMEA, 1-methoxy 2-propanol acetate) (adhesive), and about 10% graphite. Here, all percentages represent weight percentages.

[0127] In a modification of Example 1, for the heat conduction layer, an aqueous acrylic emulsion was mixed and used in water with a composition containing about 60% carboxylated styrene butadiene resin, about 20% water, about 10% propylene glycol methyl ether acetate, and about 10% graphene.

[0128] In Example 1, the same PCM (referred to as PCM_1 and PCM_2) was used for the first and second PCM layers 312a and 312b. The PCM had three PCMs, PCM1, PCM2, and PCM3, as shown in the following table. The PCM was selected to have shifted melting points in the desired range from 24°C to 37°C. The PCM was encapsulated in macro-capsules having a size of 300 micrometers, and each micro-capsule contained a plurality of micro-capsules of the three PCMs. The three types of PCM used and their melting points were as follows.

[0129]

Table 4

[0130] (Example 3) In Example 3, the same PCM cooling structure as in Example 1 was applied on the concrete substrate. However, only graphite was added to the heat conduction layer 318. A significant decrease in the cooling effect was observed.

[0131] (Example 4) In Example 4, the same PCM cooling structure as in FIG. 9 was used, and PCM was added to the PU backing layer 210' and the heat conduction layer 508 as in Example 1. In Example 4, there was no PCM layer 312 on the carrier 308. Excellent cooling was observed, but the decrease in the overheat temperature was smaller than that in Example 1.

[0132] (Examples 5, 6, 7) In Examples 5, 6, and 7, a turf structure was formed in the same manner as in Example 1, except that different combinations of the three PCMs were used in each of these examples as shown in the following table.

[0133]

Table 5

[0134] (Example 8) Using the same PCM material as in Example 1, a filler material containing filler rubber particles was coated with a PCM shell layer having a thickness of 400 micrometers. The PCM material in liquid form was mixed with the filler rubber particles, the particles were dried, the PCM shell layer was cured and solidified. Next, a thermally conductive shell layer 145 containing graphite was formed on the PCM shell layer 143. The thermally conductive layer was mixed in liquid form with the filler particles having the PCM shell layer, dried, cured, and solidified to obtain a filler material having a plurality of filler particles as shown in FIG. 14. The thermally conductive mixture in liquid form contains about 60% PU prepolymer, about 22% solvent naphtha (a mixture of light aromatic hydrocarbons obtained from coal tar or petroleum), about 8% propylene glycol methyl ether acetate (PGMEA, 1-methoxy 2-propanol acetate) (adhesive), and about 10% graphite. Here, all percentages represent weight percentages.

[0135] In a modification of Example 8, an aqueous acrylic emulsion was used for the thermally conductive shell layer. This was a composition containing about 60% carboxylated styrene butadiene resin, about 20% water, about 10% propylene glycol methyl ether acetate, and about 10% graphene, mixed in water. All percentages represent weight percentages.

[0136] To overcome processing problems, an encapsulated PCM having a suitable melting point was selected, which is in the form of a powder of small micron-sized particles. With such an encapsulated PCM, it becomes possible to carry out the processing using existing dispersion techniques during the formulation and preparation of various layer compositions.

[0137] Also, the installation speed for controlling the wet film thickness of the textured aqueous PCM layer (top coat) is at least controlled (e.g., measured) by the particle size distribution of the aggregate material used. Accordingly, the particle size of the encapsulated PCM was selected to prevent adverse changes to the installed thickness of the PCM layer.

[0138] In the above examples, adding encapsulated PCM into the top coat or into the PU backing, and adding graphite / graphene into the thermal conductive layer, respectively, have been shown to require no additional dispersion technology or process changes other than changes to masterbatch (MB) thickeners and colorants for rheology and color adjustment. Also, no adverse effects were observed on the adhesion of the intermediate layer or substrate.

[0139] Although the invention has been described with reference to specific embodiments, it should be understood that the invention is not limited to these examples only, and that many variations of these embodiments can be readily envisioned by those skilled in the art after reading this disclosure.

Explanation of Signs

[0140] 102, 104, 106, 108, 110, 112, 114, 116, 118 Method steps 141 Filler particles 143 PCM shell layer 145 Thermally conductive shell layer 151 Filling material 201 First tank for the first mixture 202 First mixture 203 Second tank for the second mixture 204 Second mixture 205 Third tank or container for the third mixture 206 Third mixture 208 Blender 210 Polyurethane reaction mixture 210’ Polyurethane backing with PCM 211 Polyurethane backing without PCM Hose of the 212 backing assembly Opening of the 214 hose Fibers or blades protruding from the 302 carrier 304 Knife 306 Roll 308 Carrier, e.g., textile mesh 312 PCM layer 318 Heat conduction layer 400 Polymer mixture for fiber formation 402 Hydrophobic fiber polymer 404 Additive 406 Additive 408 Plate Opening of the 410 extrusion nozzle 412 Extruded monofilament 501 Artificial turf fiber 502 Cutting step 503 Fiber loop Fiber portion within the 504 carrier Fiber portion protruding from the back side of the 506 carrier 508 Heat conduction layer 600 Artificial turf Fiber portion protruding from the front side of the carrier, embedded in the 602 polyurethane reaction mixture Fiber portion protruding from the front side of the carrier, not embedded in the 604 polyurethane reaction mixture PU Polyurethane PCM Phase change material HCM Heat conductive material

Claims

1. An infill material for artificial turf, comprising: The filling material is a plurality of particles at least partially coated with a PCM shell layer comprising at least one PCM; a thermally conductive shell layer formed on the PCM shell layer, the thermally conductive shell layer covering at least a portion of the PCM shell layer; having The thermally conductive shell layer comprises a thermally conductive material of graphite, graphene, or a combination thereof.

2. The filling material of claim 1 , wherein the PCM is encapsulated in a microcapsule or macrocapsule.

3. the PCM comprises paraffin wax encapsulated in microcapsules having a diameter of 15 to 30 micrometers, the microcapsules being dispersed within a polymer matrix; or 3. The filling material of claim 1 or 2, wherein the PCM comprises paraffin wax encapsulated in microcapsules having a diameter of 15 to 30 micrometers, the microcapsules being encapsulated within macrocapsules, and the macrocapsules being dispersed within the polymer matrix.

4. The filler material of claim 1 , wherein the thermally conductive material comprises a nano-graphite composite.

5. 5. The filler material of claim 4, wherein the thermally conductive material is dispersed on a polyurethane or acrylic material.

6. 2. The filling material of claim 1, wherein the PCM has a melting point of from 15°C to 45°C, preferably from 25°C to 40°C, more preferably from 25°C to 37°C.

7. the PCM shell layer comprises a first and a second PCM shell layer, and the amount of the PCM in the first PCM shell layer is at least 5.0%, in particular 10 to 30%, in particular 10 to 25% less than the amount of the PCM in the second PCM shell layer; or 2. The infill material according to claim 1, wherein the PCMs are preferably at least two different PCMs, or more preferably three different PCMs, which have different melting points from each other within the desired operating temperature of the artificial turf.

8. the thermally conductive shell layer comprises graphene, graphite, or a combination of graphene and graphite in an amount of 6.0 to 24 wt.%, in particular 7.0 to 17.0 wt.%, in particular 10.0 to 14.0 wt.%, based on the total weight of the thermally conductive shell layer on a dry basis; the amount of PCM in the PCM shell layer is from 5.0 to 12.5 wt.-%, in particular from 6.0 to 10.0 wt.-%, in particular from 7.0 to 9.0 wt.-%, based on the total weight of the PCM shell layer on a dry basis; the PCM shell layer has a thickness of 200 μm to 800 μm, in particular 400 μm to 600 μm, in particular 450 μm to 550 μm; 2. The filling material of claim 1, wherein the thermally conductive shell layer has a thickness of 5 μm to 500 μm, 50 μm to 300 μm, preferably 100 μm to 150 μm.

9. An artificial turf, Career and an artificial turf fiber or blade embedded in the carrier, a first portion of the artificial turf fiber or blade protruding on a back side of the carrier, a second portion of the artificial turf fiber or blade protruding on a front side of the carrier, and a third portion of the artificial turf fiber or blade being inside the carrier; a polyurethane backing formed on the back side of the carrier; having The infill material according to claim 1 is placed on top of the carrier between the artificial turf fibers or blades; On a hot, sunny day, heat from the fibers of the blade is conducted through the thermally conductive shell layer of the filler material particles, to the PCM shell layer of the filler material particles, and further towards the carrier of the artificial turf.

10. 10. The artificial turf of claim 9, further comprising the polyurethane backing formed within the carrier, and a layer also formed on the carrier, the layer including a PCM.

11. moreover, At least one PCM layer formed on the carrier containing a PCM; and / or at least one thermally conductive layer formed on the back side of the polyurethane backing; The artificial turf according to claim 10, having

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