[0001] The invention relates to artificial turf and a method for the manufacture of an artificial
turf infill.
[0002] Artificial turf or artificial grass is a surface that is made up of fibers and is
used to replace grass. The structure of the artificial turf is designed such that
the artificial turf has an appearance that resembles grass. Artificial turf is typically
used as a surface for sports such as soccer, American football, rugby, tennis and
golf, or for playing fields or exercise fields. Furthermore, artificial turf is frequently
used for landscaping applications.
[0003] Artificial turf may be manufactured using techniques for manufacturing carpets. For
example, artificial turf fibers, which have the appearance of grass blades, may be
tufted or attached to a backing. Oftentimes, artificial turf infill is placed between
the artificial turf fibers.
[0004] Artificial turf infill is a granular material that covers the bottom portion of the
artificial turf fibers. The use of artificial turf infill may have a number of advantages.
For example, artificial turf infill may help the artificial turf fibers stand up straight.
Artificial turf infill may also absorb impact from walking or running and provide
an experience similar to being on real turf. The artificial turf infill may also help
keep the artificial turf carpet flat and in place by weighing it down.
[0005] Even though the artificial turf known from the art is in constant development,, artificial
turf is often subjected to bad weather conditions, such as severe heat and temperature
variations, which may lead to rapid degradation of the artificial turf, or even to
problems in upkeep and maintaining the artificial turf in its optimal conditions for
use.
[0006] Further, in the hot season, when the outside surfaces are subjected to severe heat,
the use of artificial turf as a surface is extremely taxing for the person spending
time on the turf, since the artificial turf with conventional artificial turf infill
materials, as e.g. rubber, tend to heat up.
[0007] US 10,066,345 B2 discloses an artificial turf field system comprising a plurality of turf strands
attached to a backing layer and an infill material positioned between the synthetic
turf strands. The infill material includes a plurality of porous particles, wherein
at least a portion of the porous particles have a partial polymer coating thereon
and wherein the porous particles have varying amounts of their outer surface covered
by the coating. Since the porous particles disclosed in
US 10,066,345 show good water retention and the particles are partially covered, the porous particles
are beneficial in inclement weather and the wear of the porous particles is reduced
due to the partial cover.
US 10,066,345 B2 further discloses that this polymer cover is applied to the porous particles by e.g.
atomization of the polymer and spraying the polymer onto the particles as the particles
are moving or falling. Hence, the particles are partially covered on one side with
the polymer. The cover completely covers the pores of the porous particles in the
area of the cover.
[0008] It is therefore the purpose of the invention to provide an alternative or improved
artificial turf.
[0009] The invention provides for an improved artificial turf and artificial turf infill.
The problem is solved by the features as specified in the independent claims. Embodiments
of the invention are given in the dependent claims. The embodiments and examples described
herein can freely be combined with each other unless they are mutually exclusive.
[0010] In one aspect, the invention relates to an artificial turf, comprising an artificial
turf carpet, wherein the artificial turf carpet comprises multiple artificial turf
fiber tufts and an artificial turf infill. The artificial turf may have a pile height
between 2.5 cm and 7.5 cm. The pile height is the length of the artificial turf fibers
above the backing or base of the artificial turf carpet. The artificial turf fiber
tufts may be arranged in rows and may have a row spacing between 0.5 cm and 1.95 cm.
The artificial turf further comprises granular artificial turf infill spread between
the multiple artificial turf fiber tufts. The artificial turf infill material may
provide support for the artificial turf grass fibers and may have a thickness of about
5-60 mm.
[0011] The artificial turf infill is scattered or brushed between the multiple artificial
turf fiber tufts. It is within the scope of the invention that the artificial turf
infill comprises a plurality of microporous zeolite mineral particles.
[0012] The term "zeolite mineral" as used herein refers to a group of more than 60 soft,
white aluminosilicate minerals of tectosilicate type - a three-dimensional framework
of interconnected tetrahedra, comprising to a large extent aluminum, silicon and oxygen
atoms. Zeolite minerals have a crystalline structure built from [AlO
4]
5- and [SiO
4]
4- bonded together in such a way that all four oxygen atoms, located at the corners
of each tetrahedron, are shared with adjacent tetrahedral crystals. The general formula
of zeolites can be described as Me
2/nO·Al
2O
3·xSiO
2·yH
2O, whereby Me is any alkaline or alkaline earth atom, n is the charge on that atom,
x is the number of Si tetrahedrons (varying from 2 to 10), and y is the number of
water molecules, typically between 2 and 7. Examples of natural zeolites include chabazite,
erionite, mordenite, clinoptilolite, phillipsite and stilbite. Preferred zeolites
according to the invention may include chabazite, erionite, mordenite, clinoptilolite,
phillipsite and stilbite and may be obtained by mining due to their abundance in nature,
resulting in lower production costs compared with the same amount of synthetic zeolites,
such as faujasite, zeolite A, zeolite L, zeolite Y, zeolite X and ZSM-5. Synthetic
zeolite minerals may also be used instead of or in addition to natural zeolites. The
term "microporous zeolite mineral particle" as used in the invention refers to porous
zeolite mineral particles such as those disclosed above, which are able to absorb
and adsorb (also referred to as sorption) water, which can be reversibly released
from the microporous zeolite mineral particles.
[0013] Since the microporous zeolite mineral particles are distributed between the artificial
turf fiber tufts, water may be taken up by the microporous zeolite mineral particles
and stored within the microporous zeolite mineral particles in an enhanced matter,
compared to known commonly used infill materials, such as rubber granules. In addition,
seeping of water into the deeper layers of the sports flooring, from where it is not
recoverable, may be reduced.
[0014] The microporous zeolite mineral particles have pores that form openings on the outer
surface of the microporous zeolite mineral particles. Hence, the use of the microporous
zeolite mineral as an infill material is advantageous, as the particles are able to
regulate the presence of water and may thus provide for a cooling effect of the surface
of the artificial turf. Hence, an increased playing comfort can be reached when the
outside temperatures are high.
[0015] It is hereby envisaged that the outer surface of at least some microporous zeolite
mineral particles is partly covered with a polyurethane coating. It may be feasible
that 75 % to 99 % of the outer surface of a microporous zeolite mineral particle is
partly covered with a polyurethane coating.
[0016] It is provided that the partial covering is applied on each side of each microporous
zeolite mineral particle, but that there are gaps (holes) in the covering enclosing
the particles. The partial coating is advantageous, since water can be absorbed and/or
released by the microporous zeolite mineral particles through the pores contained
in its surface areas, which are not covered by the polyurethane coating. In addition,
since the microporous zeolite mineral particles are partly coated with the polyurethane
coating, natural occurrence of abrasion and wear of the microporous zeolite mineral
during use may be reduced, since the polyurethane coating may provide for a harder
and thus protective surface compared to uncoated microporous zeolite mineral particles.
It may also be advantageous that the Mohs hardness of polyurethane coating can be
chosen to be higher or much higher than the Mohs hardness of the microporous zeolite
mineral particles. It may be thus beneficial that the Mohs hardness of the polyurethane
coating is at least one Mohs unit higher than the Mohs hardness of the selected microporous
zeolite mineral particles.
[0017] The gaps in the coating of the inventive infill material may result during the manufacture
of the infill material, as during the mixing, e.g. in a flow reactor or a batch reactor
or a tumbler, the microporous zeolite mineral particles and a liquid polyurethane
reaction mixture are mixed and while they are being mixed a solidification reaction
is initiated. During the mixing and while the solidification takes place, the microporous
zeolite mineral particles physically touch and interact with each other, thereby causing
collision defects (e.g. gaps) in the coating and partly leaving the surface of the
microporous zeolite particles uncovered. Thus, water may still be absorbed and released
by the microporous zeolite mineral particles in these areas in which the pores of
the microporous zeolite minerals are not covered by the polyurethane coating.
[0018] It is further envisaged that the polyurethane coating extends over some of the pores
forming respective covers of the pore openings, wherein the polyurethane coating coats
a portion of the inner surface of the covered pores in the region of the cover. The
coating may penetrate a slight distance, for example between 0.2 µm and 500 µm, preferably
between 1 and 150 µm and most preferred between 10 µm and 100 µm into the surface
pores and thus may interfere with the pores in a form-locking manner. Thereby the
hold of the coating on the microporous zeolite mineral particles may be increased
and at the same time the overall stability and hardness of the microporous zeolite
mineral particles may be increased.
[0019] Further, since the infill material is preferably produced by mixing the microporous
zeolite mineral particles with a liquid polyurethane reaction mixture and initializing
the solidification reaction during the mixing, the microporous zeolite mineral particles
have the same amount of their outer surface covered by the coating relative to the
total outer surface. Substantially the same amount means that the outer surface of
each of the partly coated microporous zeolite mineral particle is coated between 20
% and 99 %, preferably between 50 % to 98 % or between 70% to 99 %, with the polyurethane
coating. Further, since the outer surface of each of the partly coated microporous
zeolite mineral particle is - with the exception of the gaps - essentially fully coated,
fine dusts may be bound.
[0020] The granular artificial turf infill may further be comprised of microporous zeolite
mineral particles, the surfaces of which are partly coated with a polyurethane coating,
which are mixed with other artificial turf infill granules, such as rubber granules
and/or cork granules. Hereby, the rubber granules and/or cork granules may be coated
with a polyurethane coating.
[0021] As described above, the artificial turf infill comprising microporous zeolite mineral
particles, which may be in the form of a granule, may be advantageous for regulating
the presence of water on an artificial turf. For example, before a football game that
is scheduled to be held in the sun or in hot conditions, water may be sprayed onto
the artificial turf, and the microporous zeolite mineral particles of the turf infill
may absorb an amount of water. As the sun or hot air heats the artificial turf with
the artificial turf infill during the game, the evaporation of water may cool the
playing surface and make the use of the artificial turf more pleasant for the players.
[0022] The spraying of water may be performed manually with a water hose or automatically
with a sprinkler system.
[0023] In one embodiment of the invention, the artificial turf comprises a sprinkler system.
[0024] The use of a sprinkler system may be beneficial because it may be used to automatically
moisten the surface of the artificial turf. For example, this may be a convenient
means of watering the artificial turf surface during a time period that is defined
based on the minimum release rate of the water from the microporous zeolite mineral.
For example, the selected microporous mineral may have a specific surface area that
enables the water to steadily release over a time period of two to three hours. In
this case, the sprinkler system may be configured to water the artificial turf at
a predefined time (or predefined time duration) before a match.
[0025] In one embodiment, the microporous zeolite mineral particle is selected from the
group consisting of chabazite, erionite, mordenite, clinoptilolite, faujasite, phillipsite,
zeolite A, zeolite L, zeolite Y, zeolite X and ZSM-5. The zeolite used within the
scope of the invention may thus be a zeolite that can be natural or obtained by synthesis.
[0026] Since artificial turf infill may be used to modify an artificial turf carpet to have
more earth-like properties, a microporous zeolite, with a Mohs hardness above 3 and/or
a strong absorbent power and/or a color that approximately resembles one of the well-known
surface colors (e.g., red, brown, green), may preferably be used. The most preferred
microporous zeolite mineral may be of the chabazite and/or clinoptinolite and/or mordenite
type.
[0027] Further, the specific surface area of the microporous zeolite mineral particle can
be chosen to be smaller than a predetermined maximum specific surface area. The maximum
specific surface area of the mineral may, for example, be determined as the surface
specific area that enables the water in the mineral to release, under a certain ambient
temperature, at a predefined minimum rate.
[0028] In one embodiment of the invention, the polyurethane coating of the artificial turf
infill is based on a liquid polyurethane reaction mixture, which may be a dispersion
or solution, comprising
- at least one isocyanic prepolymer with a totally blocked isocyanic functionality;
- a hydroxyl component, wherein the hydroxyl component is selected from the group of
polyether polyol or polyester polyol; and
- at least one catalyst selected from the group consisting of linear or cyclic tertiary
amines such as triethylenediamine, or e.g.1,4-Diazabicyclo[2.2.2]octane, cyclic amines
such as 1,8-Diazabicyclo(5.4.0)undec-7-ene (DBU) and inorganic compounds such as sodium
hydroxide (NaoH), chromium(III) oxide and zinc oxide (ZnO).
[0029] The use of an above-described liquid polyurethane reaction mixture may be advantageous,
because it is a reaction mixture that can be solidified or cured (e.g., by cross-linking)
under heat and/or by adding water. Therefore, the zeolite mineral particles and the
liquid polyurethane reaction mixture may be mixed and solidified simultaneously in
a batch reactor, a continuous reactor or a tumbler, resulting in the partial polyurethane
coating or the coating with gaps. Further, the resulting polyurethane coating may
be a waterborne polyurethane coating.
[0030] In an alternative embodiment of the invention, the polyurethane coating of the artificial
turf infill is based on a liquid polyurethane reaction mixture comprising:
- i. NCO terminal polymer, one or more component selected from a prepolymer, a polymeric
isocyanate, an oligomeric isocyanate, a monomer, such as
- a. aromatic diisocyanate of the group of toluene diisocyanate and/or methylene- 2,2
-diisocyanate or
- b. aliphatic diisocyanate of the group hexamethylene diisocyanate, isophorone diisocyanate,
and/or 1,4-cyclohexyldisiocyanate; and ii. Hydroxyl component, wherein the hydroxyl
component is selected from the group of polyether polyol or polyester polyol.
[0031] The use of an above-described liquid polyurethane reaction mixture may be advantageous,
because it is a reaction mixture that can be solidified or cured (e.g., by cross-linking)
by adding a catalyst, e.g. a secondary amine catalyst, a tertiary amine catalyst,
such as triethylenediamine or e.g.1,4-Diazabicyclo[2.2.2]octane, cyclic amines such
as 1,8-Diazabicyclo(5.4.0)undec-7-ene (DBU) or a metal organic catalyst, and water.
Therefore, the zeolite mineral particles and the liquid polyurethane reaction mixture
may be mixed and solidified simultaneously in a controlled manner in a batch or continuous
reactor, resulting in the partial polyurethane coating or the coating with holes.
[0032] In one embodiment, the polyurethane coating of the artificial turf infill comprises
at least one further component selected from the group consisting of sand, colored
sand, chalk, lime, colored pigments, copper(II)sulfate particles, flame retardants,
UV absorbers and fillers.
[0033] Adding one or more of these further components to the polyurethane coating of the
artificial turf infill may be beneficial in several different situations.
[0034] The colored pigments may be infrared-reflective pigments, which are beneficial due
to their ability to reflect infrared light. This may further reduce the heating of
the artificial turf infill. Further, as the infrared-reflective colored pigments may
be contained solely in the partially applied polyurethane coating, the costs for the
comparably expensive and precious pigments, since they are merely on the partly covered
surface of the zeolite minerals, is reduced compared to fully coated infill materials.
[0035] It is further feasible that the colored pigments may be copper(II) sulfate particles,
chromium oxide particles or iron oxide particles.
[0036] Copper(II) sulfate particles and/or or iron oxide particles and/or chromium oxide
particles may be beneficial due to their color, relatively low manufacturing costs
and/or antibacterial properties. Other antibacterial components that may be used are
silver and/or chitosan particles, which both have natural antibacterial properties.
[0037] Sand, colored sand, chalk or lime can be beneficial since they are relatively cheap
starting materials and they are naturally earth-colored. In addition, sand, colored
sand, chalk or lime can be beneficial due to their ability to increase the viscosity
of the polyurethane coating during the coating process.
[0038] The coating, which is based on a liquid polyurethane reaction mixture, may thus solidify
into the polyurethane coating while covering the microporous zeolite mineral particles.
High viscosity of the polyurethane coating may largely prevent too deep of penetration
of the polyurethane coating into the surface pores of the microporous minerals.
[0039] According to embodiments, the color of the artificial turf infill is identical or
similar to the color of the fibers or tufts that are used to manufacture an artificial
turf carpet. This may provide a more realistic-looking playing surface or field.
[0040] According to embodiments, the zeolite mineral particles, which are usually softer
than conventionally used artificial turf infill materials, are strengthened by the
polyurethane coating with added further components and may therefore have superior
wear qualities or increased weight, or may be better protected from environmental
influences such as rain, acid rain, wind or others.
[0041] Fillers can be beneficial as they are ably to increase the weight of the coating
and thus the overall weight of the artificial turf infill. The used fillers may be
selected from the group consisting of barium sulphate (barite), calcium carbonate
(chalk), china clay (kaolin) or cold fly ash.
[0042] It may be envisaged that the coating may comprise between 0.1 wt.% to 80 wt.% of
fillers.
[0043] According to one embodiment of the invention it may be envisaged that the polyurethane
coating of the artificial turf infill comprises fillers, in particular barium sulphate
(barite) and/or calcium carbonate (chalk), to increase the total weight of the artificial
turf infill.
[0044] Barium sulphate and calcium carbonate may be particular advantageous, as they have
a high density, e.g. calcium carbonate has a density of 2.7 g/cm
3 and barium sulphate has a density between 4.0 and 4.5 g/cm
3, are relatively cheap materials and may be used to provide a dense coating.
[0045] For this embodiment it is thus envisaged that the coating may comprise between 0.1
wt.% to 80 wt.%, preferably between 20 wt.% to 50 wt.%, of barium sulfate as filler
or between 0.1 wt.% to 65 wt.%, preferably between 20 wt.% to 40 wt.%, of calcium
carbonate as filler.
[0046] The increase in total weight of the artificial turf infill may provide the advantage
that the artificial turf infill can be better protected from being washed away by
rain or wind.
[0047] In another embodiment, the polyurethane coating of the artificial turf infill comprises
a rheology additive that is adapted to induce a thixotropic flow behavior in the liquid
polyurethane reaction mixture.
[0048] Adding a rheology additive with thixotropic capabilities may be advantageous in order
to achieve a controllable viscosity-increasing thixotropic flow behavior of the (e.g.,
liquid or fluid) polyurethane coating while applying it, e.g. by mixing the liquid
polyurethane reaction mixture with the microporous zeolite mineral particles, to the
surface of the microporous zeolite mineral particles in order to control or reduce
the depth of penetration of the liquid polyurethane reaction mixture into the pores
contained in the surfaces of the microporous zeolite mineral particles.
[0049] Suitable rheology additives may be e.g. fumed silica (e.g. synthetic, hydrophobic,
amorphous silica), also known as pyrogenic silica, made from flame pyrolysis of silicon
tetrachloride or from quartz sand vaporized in a 3000 °C electric arc, hydrophobic
fumed silica, bentonite, acrylates or a combination of the aforementioned additives.
[0050] It can also be within the present invention that the grain size of the microporous
zeolite minerals is between 0.03 mm and 8.0 mm.
[0051] It is further within the present invention that the layer thickness of the polyurethane
coating is between 0.001 mm and 2.0 mm.
[0052] In one embodiment, the polyurethane coating contains the following components, stated
by weight:
0.1 - 80 wt.% |
of the at least one isocyanic prepolymer, |
0.001 - 0.5 wt.% |
of 1,8-diazabicyclo(5.4.0)undec-7-ene (DBU) |
and at least one further component selected from the group consisting of
0.001 |
- 30.0 wt.% |
colored pigments, |
0.001 |
- 3.0 wt.% |
copper(II) sulfate, |
0.05 |
- 60.0 wt.% |
flame retardants, |
0.01 |
- 1.0 wt.% |
U.V. absorbers, |
0.01 |
- 60 wt.% |
filler, |
0.01 |
- 1.0 wt.% |
rheology additive, |
0.001 |
- 20.0 wt.% |
water, |
wherein the amounts by weight add up to 100 wt.% and the amounts by weight are based
on the total weight of the polyurethane coating.
[0053] The colored pigments in this embodiment may be copper(II)sulfate particles and/or
or iron oxide particles and/or chromium oxide particles. Which colored particles are
used depends on the desired color. The filler in this embodiment may be calcium carbonate
and/or china clay. The rheology additive in this embodiment may be fumed silica and/or
bentonite.
[0054] The advantages of adding color pigments and copper(II) sulfate to the polyurethane
coating are described above. As a U.V. absorber a hindered amine light stabilizer
(HALS), which is able to protect the polyurethane coating against UV degradation,
may be used.
[0055] In another embodiment, the at least one further component further comprises a thermo-stabilizing
agent, protecting the polyurethane coating against thermal degradation.
[0056] For all of the above embodiments, it may be envisaged that the microporous zeolite
mineral particles may be charged with salt ions, in order to allow for an increased
water adsorption and/or water desorption effect.
[0057] This incorporation of salt into the microporous zeolite mineral particles allows
a synergy to operate between the following properties: the adsorption, absorption
and release of water of the microporous zeolite mineral particle, and the ability
to lower the freezing temperature of the water. Actually, in the presence of humidity,
the microporous mineral particle is in a position to adsorb and/or absorb this humidity
in order to prevent, on the one hand, a surface formation of a layer of slippery frost,
in the case of a negative temperature, and on the other hand, an agglomeration of
the artificial turf infills.
[0058] In the context of using the microporous mineral particle as infill material on outside
artificial turf surfaces that are subjected to severe heat, the microporous mineral
particle, loaded with salt and water, further may allow a further increased release
of the water and the maintenance of relative humidity at the surface of said turf.
Thus, on a turf surface subjected to severe heat, when it is refreshed by watering,
the microporous mineral particle loaded with salt adsorbs and/or absorbs the water
and then continuously releases those water molecules by desorption. This continuous
release of the water by the microporous mineral particles avoids rapid evaporation
of the water after watering the surface and allows a lower temperature to be maintained
at the level of the field surface compared to the ambient temperature. Said microporous
mineral particles loaded with salt thus further allows the amount of watering usually
necessary to refresh a turf surface to be further reduced.
[0059] In a further aspect, the invention relates to an artificial turf infill, wherein
the artificial turf infill comprises a plurality of microporous zeolite mineral particles.
The microporous zeolite mineral particles comprise pores that form openings on the
outer surface of the microporous zeolite mineral particles. It is within the scope
of the invention that the outer surface of at least some of the microporous zeolite
mineral particles is partly coated with a polyurethane coating, wherein the coating
extends over some of the pores forming respective covers of the openings and wherein
the polyurethane coating coats a portion of the inner surface of the covered pores
in the region of the cover. Further, it is provided that each of the partly coated
microporous zeolite mineral particles have approximately the same amount of their
outer surface coated by the coating relative to the total outer surface.
[0060] The artificial turf infill may be an artificial turf infill as described above.
[0061] The artificial turf infill may comprise the same features and advantages as herein
described embodiments and examples of the artificial turf infill of the artificial
turf.
[0062] In one embodiment the polyurethane coating comprises at least one further component
selected from the group consisting of sand, colored sand, chalk, lime, colored pigments,
copper(II) sulfate particles, chromium particles, flame retardants, U.V. absorbers
and fillers.
[0063] In one embodiment the artificial turf infill further comprises at least one granular
component selected from the group consisting of cork granules, coated cork granules,
rubber granules and coated rubber granules.
[0064] In one embodiment at least some of the microporous zeolite mineral particles are
charged with a salt solution.
[0065] In one embodiment, the microporous zeolite mineral particles are selected from the
group consisting of chabazite, erionite, mordenite, clinoptilolite, faujasite, phillipsite,
zeolite A, zeolite L, zeolite Y, zeolite X and ZSM-5.
[0066] In one embodiment the polyurethane coating of the microporous zeolite mineral particles
comprises a rheology additive, in particular fumed silica, hydrophobic fumed silica,
bentonite, acrylate or a combination thereof.
[0067] In one embodiment the polyurethane coating of the microporous zeolite mineral particles
comprises fillers, in particular barium sulphate (barite) and/or calcium carbonate
(chalk), to increase the total weight of the artificial turf infill.
[0068] In one embodiment the polyurethane coating of the microporous zeolite mineral particles
is based on a liquid polyurethane reaction mixture comprising
- at least one isocyanic prepolymer with a totally blocked isocyanic functionality;
- a hydroxyl component, wherein the hydroxyl component is selected from the group of
polyether polyol or polyester polyol; and
- at least one catalyst selected from the group consisting of linear or cyclic tertiary
amines such as triethylenediamine, or e.g.1,4-Diazabicyclo[2.2.2]octane, cyclic amines
such as 1,8-Diazabicyclo(5.4.0)undec-7-ene (DBU) and inorganic compounds such as sodium
hydroxide (NaoH), chromium(III) oxide and zinc oxide (ZnO).
[0069] The use of an above-described liquid polyurethane reaction mixture may be advantageous,
because it is a reaction mixture that can be solidified or cured (e.g., by cross-linking)
under heat and/or by adding water. Therefore, the zeolite mineral particles and the
liquid polyurethane reaction mixture may be mixed and solidified simultaneously in
a batch reactor, a continuous reactor or a tumbler, resulting in the partial polyurethane
coating or the coating with gaps. Further, the resulting polyurethane coating may
be a waterborne polyurethane coating.
[0070] In an alternative embodiment the polyurethane coating of the microporous zeolite
mineral particles is based on liquid polyurethane reaction mixture comprising:
- i. NCO terminal polymer, one or more component selected from a prepolymer, a polymeric
isocyanate, an oligomeric isocyanate, a monomer, such as
- a. aromatic diisocyanate of the group of toluene diisocyanate and/or methylene- 2,2-diisocyanate
or
- b. aliphatic diisocyanate of the group hexamethylene diisocyanate, isophorone diisocyanate,
and/or 1,4-cyclohexyldisiocyanate; and ii. Hydroxyl component, wherein the hydroxyl
component is selected from the group of polyether polyol or polyester polyol.
[0071] The use of an above-described liquid polyurethane reaction mixture may be advantageous,
because it is a reaction mixture that can be solidified or cured (e.g., by cross-linking)
by adding a catalyst, e.g. a secondary amine catalyst, a tertiary amine catalyst,
such as triethylenediamine or e.g.1,4-Diazabicyclo[2.2.2]octane, cyclic amines such
as 1,8-Diazabicyclo(5.4.0)undec-7-ene (DBU) or a metal organic catalyst, and water.
Therefore, the zeolite mineral particles and the liquid polyurethane reaction mixture
may be mixed and solidified simultaneously in a controlled manner in a batch or continuous
reactor, resulting in the partial polyurethane coating or the coating with holes.
[0072] It is understood that one or more of the aforementioned embodiments of the invention
may be combined as long as the combined embodiments are not mutually exclusive.
[0073] Below, the following embodiments of the invention are explained in greater detail,
by way of example only, making reference to the drawings, in which:
- Fig. 1
- illustrates an example of an artificial turf carpet;
- Fig. 2
- illustrates an example of artificial turf;
- Fig. 3
- illustrates a sectional view of a microporous zeolite mineral;
- Fig. 4
- illustrates a section of the sectional view of Fig. 3;
- Fig. 5
- illustrates a sectional view of a microporous zeolite mineral particle, which is partially
coated with a polyurethane coating;
- Fig. 6
- illustrates a section of the sectional view of Fig. 5, in which the polyurethane coating
comprises a further component and a rheology additive;
- Fig. 7
- illustrates a further section of the sectional view of Fig. 6; and
- Fig. 8
- illustrates an artificial turf infill.
[0074] Like-numbered elements in these figures are either equivalent elements or perform
the same function. Elements that have been discussed previously will not necessarily
be discussed in later figures if the function is equivalent.
[0075] Figs. 1 and 2 illustrate the manufacture of an artificial turf 600 using an artificial
turf carpet 500 and artificial turf infill 10.
[0076] In Fig. 1, an artificial turf carpet 500 is shown. The artificial turf carpet 500
contains a backing 502. The artificial turf carpet 500 shown in Fig. 1 is a tufted
artificial turf carpet. The artificial turf carpet is formed by artificial turf fiber
tufts 504 that are tufted into the backing 502. The artificial turf fiber tufts 504
are tufted in rows. There is row spacing 506 between adjacent rows of tufts. The artificial
turf fiber tufts 504 also extend a distance above the backing 502. The distance that
the fibers 504 extend above the backing 502 is the pile height 508. In Fig. 1, it
can be further seen that the artificial turf carpet 500 has been installed by placing
or attaching it to the ground 510 or a floor. To manufacture the artificial turf,
the artificial turf infill is made with partially polyurethane-coated zeolite mineral
particles such as those shown in Figs. 5 to 6 and is spread out on the surface and
distributed between the artificial turf fiber tufts 504.
[0077] Fig. 2 shows the artificial turf carpet 500 after the artificial turf infill 10 has
been spread out and distributed between the artificial turf fiber tufts 504. It can
be seen that the artificial turf infill 10 is a granulate made up of individual grains
100 or granules, such as is depicted in Figs. 3 and 5.
[0078] Fig. 3 shows a schematic sectional view of a microporous zeolite mineral particle
110, whose surface contains pores (indicated by the dots). For example, the microporous
zeolite mineral 110 could be of the chabazite, erionite, and mordenite or clinoptilolite
type. In Fig. 3 a dotted circle is indicated, the schematic content of which is enlarged
in Fig. 4. As shown in the enlarged sectional view in Fig. 4, the surface of the microporous
zeolite mineral particle 110 contains pores 111, through which water may be absorbed
and adsorbed and through which water can be reversibly released.
[0079] Fig. 5 shows the same microporous zeolite mineral particle after it has been partially
coated with a polyurethane coating 120 and may thus be used as an infill material
10. As can be seen, at least some parts of the surface of the coated microporous zeolite
mineral particle 110 are not covered by the polyurethane coating. In Fig. 5 a dotted
circle is also indicated, the schematic content of which is enlarged in Fig. 6.
[0080] As shown in the enlarged sectional view in Fig. 6 the microporous zeolite mineral
particle 110, which contains pores 111, has been partially coated with a polyurethane
coating 120. The polyurethane coating 120 was formed by providing microporous zeolite
mineral particles 110 and a liquid polyurethane reaction mixture in a batch reactor,
tumbler or continuous reactor. Simultaneous mixing and initialization of the solidification
reaction lead to the desired partial coating of the polyurethane coating 120 on the
surface of the microporous zeolite mineral particle 110. The partial coating results
from microporous zeolite mineral particles 110 colliding while being mixed with the
initialized liquid polyurethane reaction mixture. Since the initialization of the
solidification reaction takes place simultaneously, uncovered spaces (gaps or holes),
created by collisions, remain on the surface of the microporous zeolite mineral particles
and thus the artificial turf infill 10. Further, as shown in Fig. 6 the polyurethane
coating 120 coats a portion of the inner surface of the microporous zeolite mineral
particle 110 in the region of the cover. The coating 120 may penetrate with a slight
distance, for example between 0.2 µm and 500 µm, preferably between 1 and 150 µm and
most preferred between 10 µm and 100 µm into the surface pores 111 and thus may interfere
with the pores 111 in a form-locking manner. Thereby the hold of the coating on the
microporous zeolite mineral particle 110 may be increased and at the same time the
overall stability and hardness of the microporous zeolite mineral particle 110 may
be increased. Further, since the infill material 10 is preferably produced by mixing
the microporous zeolite mineral particles with a liquid polyurethane reaction mixture
and initializing the solidification reaction during the mixing, the microporous zeolite
mineral particles have substantially the same amount of their outer surface covered
by the coating relative to the total outer surface. Substantially the same amount
means that the outer surface of each microporous zeolite mineral particle is covered
between 20 % and 99 %, preferably between 50 % to 98 % or between 70% to 99 %, with
the polyurethane coating 120. Since the outer surface of each microporous zeolite
mineral particle 110 is - with the exception of the gaps - essentially fully coated,
fine dusts may be bound. As further shown in another embodiment, the polyurethane
coating 120 of this artificial turf infill granule contains a further component 121.
The further component 121 may be for example sand and/or colored sand and/or chalk
and/or lime. With the addition of sand and/or colored sand and/or chalk and/or lime
to the liquid polyurethane reaction mixture of the polyurethane coating 120, the viscosity
of the liquid polyurethane reaction mixture can be increased. Thus during the mixing
of the liquid polyurethane reaction mixture with the microporous zeolite mineral particle
110 while manufacturing the artificial turf infill, some portions of the surfaces
of the microporous zeolite mineral particles remain open upon application of the polyurethane
coating, since the penetration depth of the polyurethane coating is a function of
the viscosity. As further shown, the polyurethane coating 120 of this artificial turf
infill may comprise a rheology additive 122. The rheology additive may be added in
order to achieve thixotropic flow behavior of the liquid polyurethane reaction mixture
during mixing of the liquid polyurethane reaction mixture with the microporous zeolite
mineral particle 110. The viscosity of the liquid polyurethane reaction mixture is
controllable via the addition of the rheology additive and thus the depth of penetration
of the liquid polyurethane reaction mixture into the pores 111 contained in the surfaces
of the microporous zeolite mineral particles 110 can be controlled. As can be seen
in Fig. 6, the polyurethane coating is mainly solidified or cured on the outer surface
of the microporous zeolite mineral particles 110, however the polyurethane coating
120 also coats a portion of the inner surface of the pores 111 in the region of the
cover. The coating 120 may penetrate a slight distance, for example between 1 µm and
500 µm, into the surface pores 111, thereby interfering with the pores 111 in a form-locking
manner. Thus the hold of the coating on the microporous zeolite mineral particles
110 may be increased and at the same time the overall stability and hardness of the
microporous zeolite mineral particles 110 may be increased.
[0081] As shown in Fig. 7, which is an enlarged sectional view of the enlarged sectional
view indicated in Fig. 6 by the dotted square, the microporous zeolite mineral particle110,
which contains pores 111, has been partially coated with a polyurethane coating 120.
The microporous zeolite mineral particles 110 contain pores 111 that have openings
on the outer surface of the microporous zeolite mineral particles 110. As depicted,
the outer surface of the microporous zeolite mineral particle 110 is partly coated
with a polyurethane coating 120, wherein the coating extends over some of the pores
111 forming respective covers (equals the pore size at the outer surface; indicated
by 130) of the openings. The cover 130 covers the pore 111 in the area of the pore
opening. As shown in the Fig. 7 for the two covered pores (i.e., the two right pores),
the polyurethane coating 120 coats a portion of the inner surface of the covered pores
111 in the region of the cover 130. Hereby, the polyurethane coating 120 of the inner
surface may be in the form of a plug, as indicated in the left covered pore 111 or
in the form of a film, as indicated in the right covered pore 111.
[0082] Fig. 8 depicts an inventive artificial turf infill granule 10 (i.e., partly coated
microporous zeolite mineral particles 110). The microporous zeolite mineral particle
110 has pores 111 that form openings on the outer surface of the microporous zeolite
mineral particles 110. As shown, the outer surface of the microporous zeolite mineral
particles 110 is partly coated with a polyurethane coating 120, wherein the coating
extends over most of the pores 111, thereby forming respective covers of the openings.
The polyurethane coating 120 was formed by providing a plurality of microporous zeolite
minerals particles 110 and a liquid polyurethane reaction mixture in a batch reactor,
tumbler or continuous reactor. Simultaneous mixing and initialization of the solidification
reaction lead to the desired partial coating of the polyurethane coating 120 on the
surface of the microporous zeolite mineral particle 110. The partial coating results
from collisions of microporous zeolite mineral particles 110 while being mixed with
the initialized liquid polyurethane reaction mixture. Since the initialization of
the solidification reaction takes place simultaneously, uncovered spaces (e.g., gaps
or holes), created by collisions, remain on the surface of the microporous zeolite
mineral particles and thus the artificial turf infill 10 granule. As indicated in
Fig. 8, it may be feasible that 75 % to 99 % of the outer surface of the microporous
zeolite mineral particle is partly covered with a polyurethane coating 120.
List of Reference Numerals
[0083]
- 10
- artificial turf infill
- 100
- grains or granules
- 110
- microporous zeolite mineral particle (grain or granule)
- 111
- pores
- 120
- polyurethane coating
- 121
- further component of polyurethane coating
- 122
- rheology additive
- 130
- cover
- 500
- artificial turf carpet
- 502
- backing
- 504
- artificial turf fiber tufts
- 506
- row spacing between adjacent rows of tufts
- 508
- pile height
- 510
- ground or floor
- 600
- artificial turf
1. An artificial turf (600), comprising:
- an artificial turf carpet (500), wherein the artificial turf carpet comprises multiple
artificial turf fiber tufts (504); and
- an artificial turf infill (10), which is scattered between the multiple artificial
turf fiber tufts (504), wherein the artificial turf infill (10) comprises a plurality
of microporous zeolite mineral particles (110), the microporous zeolite mineral particles
(110) having pores (111) that form openings on the outer surface of the microporous
zeolite mineral particles (110), wherein the outer surface of at least some of the
microporous zeolite mineral particles (110) is partly coated with a polyurethane coating
(120), wherein the coating extends over some of the pores (111) forming respective
covers (130) of the openings, wherein the polyurethane coating (120) coats a portion
of the inner surface of the covered pores (111) in the region of the cover (130) and
wherein the microporous zeolite mineral particles (110) have the same amount of their
outer surface coated by the coating (120) relative to the total outer surface.
2. The artificial turf (600) of claim 1, wherein the microporous zeolite mineral particles
(110) are selected from the group consisting of chabazite, erionite, mordenite, clinoptilolite,
faujasite, phillipsite, zeolite A, zeolite L, zeolite Y, zeolite X and ZSM-5.
3. The artificial turf (600) of any of the preceding claims, wherein the polyurethane
coating (120) is based on a liquid polyurethane reaction mixture comprising
- at least one isocyanic prepolymer with blocked isocyanic functionality;
- a hydroxyl component, wherein the hydroxyl component is selected from the group
of polyether polyol or polyester polyol; and
- at least one catalyst selected from the group consisting of linear or cyclic tertiary
amines such as triethylenediamine, 1,4-Diazabicyclo[2.2.2]octane, cyclic amines such
as 1,8-Diazabicyclo(5.4.0)undec-7-ene (DBU) and inorganic compounds such as sodium
hydroxide (NaOH), chromium(III) oxide and zinc oxide (ZnO).
4. The artificial turf (600) of any of the preceding claims, wherein the polyurethane
coating (120) is based on liquid polyurethane reaction mixture comprising at least
one of the following components:
i. NCO terminal polymer, one or more component selected from a prepolymer, a polymeric
isocyanate, an oligomeric isocyanate, a monomer, such as
a. aromatic diisocyanate of the group of toluene diisocyanate and/or methylene-2,2-diisocyanate
or
b. aliphatic diisocyanate of the group hexamethylene diisocyanate, isophorone diisocyanate,
and/or 1,4-cyclohexyldisiocyanate; and
ii. Hydroxyl component, wherein the hydroxyl component is selected from the group
of polyether polyol or polyester polyol.
5. The artificial turf (600) according to at least one of the preceding claims, wherein
the polyurethane coating (120) comprises at least one further component (121) selected
from the group consisting of sand, colored sand, chalk, lime, color pigments, copper(II)
sulfate particles, flame retardants, U.V. absorbers and fillers.
6. The artificial turf (600) according to one of the claims 1 to 4 or 5, wherein the
polyurethane coating (120) comprises fillers, in particular barium sulphate (barite)
and/or calcium carbonate (chalk), to increase the total weight of the artificial turf
infill (10).
7. The artificial turf (600) according to at least one of the preceding claims, wherein
the polyurethane coating (120) comprises a rheology additive (122), in particular
fumed silica, hydrophobic fumed silica, bentonite, acrylate or a combination thereof.
8. An artificial turf infill (10), wherein the artificial turf infill (10) comprises
a plurality of microporous zeolite mineral particles (110), the microporous zeolite
mineral particles (110) having pores (111) that form openings on the outer surface
of the microporous zeolite mineral particles (110), wherein the outer surface of at
least some of the microporous zeolite mineral particles (110) is partly coated with
a polyurethane coating (120), wherein the coating extends over some of the pores (111)
forming respective covers (130) of the openings, wherein the polyurethane coating
(120) coats a portion of the inner surface of the covered pores in the region of the
cover (130) and wherein the microporous zeolite mineral particles (110) have the same
amount of their outer surface coated by the coating (120) relative to the total outer
surface.
9. The artificial turf infill (10) according to claim 8, wherein the polyurethane coating
(120) comprises a rheology additive (122), in particular fumed silica, hydrophobic
fumed silica, bentonite, acrylate or a combination thereof.
10. The artificial turf infill (10) according to claim 8 or claim 9, wherein the polyurethane
coating (120) comprises at least one further component (121) selected from the group
consisting of sand, colored sand, chalk, lime, colored pigments, copper(II) sulfate
particles, flame retardants, U.V. absorbers and fillers.
11. The artificial turf infill (10) according to one of the claims 8 to 10, wherein the
polyurethane coating (120) comprises fillers, in particular barium sulphate (barite)
and/or calcium carbonate (chalk), to increase the total weight of the artificial turf
infill (10).
12. The artificial turf infill (10) according to one of claims 8 to 11, wherein the artificial
turf infill (10) further comprises at least one granular component selected from the
group consisting of cork granules, coated cork granules, rubber granules and coated
rubber granules.
13. The artificial turf infill (10) according to one of claims 8 to 12, wherein at least
some of the microporous zeolite mineral particles (110) are charged with a salt solution.
14. The artificial turf infill (10) according to one of claims 8 to 13, wherein the microporous
zeolite mineral particles (110) are selected from the group consisting of chabazite,
erionite, mordenite, clinoptilolite, faujasite, phillipsite, zeolite A, zeolite L,
zeolite Y, zeolite X and ZSM-5.
15. The artificial turf infill (10) according to one of claims 8 to 14, wherein the polyurethane
coating (120) is based on a liquid polyurethane reaction mixture comprising
- at least one isocyanic prepolymer with a totally blocked isocyanic functionality;
- a hydroxyl component, wherein the hydroxyl component is selected from the group
of polyether polyol or polyester polyol; and
- at least one catalyst selected from the group consisting of linear or cyclic tertiary
amines such as triethylenediamine, or e.g.1,4-Diazabicyclo[2.2.2]octane, cyclic amines
such as 1,8-Diazabicyclo(5.4.0)undec-7-ene (DBU) and inorganic compounds such as sodium
hydroxide (NaoH), chromium(III) oxide and zinc oxide (ZnO).
16. The artificial turf infill (10) according to one of claims 8 to 14, wherein the polyurethane
coating (120) is based on liquid polyurethane reaction mixture comprising at least
one of the following components:
i. NCO terminal polymer, one or more component selected from a prepolymer, a polymeric
isocyanate, an oligomeric isocyanate, a monomer, such as
a. aromatic diisocyanate of the group of toluene diisocyanate and/or methylene-2,2-diisocyanate
or
b. aliphatic diisocyanate of the group hexamethylene diisocyanate, isophorone diisocyanate,
and/or 1,4-cyclohexyldisiocyanate; and
ii. Hydroxyl component, wherein the hydroxyl component is selected from the group
of polyether polyol or polyester polyol.