WATER-RETAINING ARTIFICIAL TURF

Abstract

The invention relates to artificial turf, synthetic backing material, synthetic filament, and cooling of artificial turf. The artificial turf comprises synthetic turf filaments, the synthetic turf filaments comprise a blend, the blend comprises 65-99.5% by total weight of the blend of a polyolefin, and 0.5-35% by total weight of the blend of a hydrophilic polymer, wherein the polyolefin is polyethylene, polypropylene, or any combination thereof, and wherein the artificial turf is preferably in the form of a tile carpet.

Claims

1. Artificial turf, comprising synthetic turf filaments, the synthetic turf filaments comprise a blend, and the blend comprises 65-99.5% by total weight of the blend of a polyolefin, and 0.5-35% by total weight of the blend of a hydrophilic polymer, wherein the polyolefin is polyethylene, polypropylene, or any combination thereof.

2. Artificial turf according to claim 1, wherein the blend further comprises an ionomer resin.

3. Artificial turf according to claim 1, wherein the artificial turf is in the form of a tile or carpet.

4. Artificial turf according to claim 1, wherein the blend comprises i) 65-95% by total weight of the blend of the polyethylene, and/or ii) 1-30% by total weight of the blend of the hydrophilic polymer, and/or iii) 0.1-10% by total weight of the blend of an ionomer resin.

5. Artificial turf according to claim 1, wherein the blend further comprises up to 25% by total weight of the blend of one or more additives.

6. Artificial turf according to claim 1, wherein the polyethylene has i) a density, as measured according to ISO 1183, in the range of 0.88-0.99 g/cm.sup.3, and/or ii) a melt flow index, as measured according to ISO 1133 at a load of 2.16 kg and at a temperature of 190° C., of 0.1-10 g/10 min, and/or iii) a melting point, as measured according to ISO 11357, in the range of 100-180° C.

7. Artificial turf according to claim 1, wherein the polyethylene comprises one or more selected from the group consisting of very low-density polyethylene, low-density polyethylene, linear low-density polyethylene, medium- density polyethylene, and high-density polyethylene.

8. Artificial turf according to claim 1, wherein the polypropylene is selected from the group consisting of homopolymers of propylene, random copolymers of propylene and one or more other olefins, block copolymers of propylene and one or more other olefins, and terpolymers of propylene, ethylene and dienes.

9. Artificial turf according to claim 1, wherein the hydrophilic polymer comprises one or more synthetic polymers and/or one or more natural polymers, wherein the one or more synthetic polymers are selected from the group consisting of polyvinyl alcohol, polyvinyl acetate, polyvinylpyrrolidone, polyacrylic acid, polyacrylamide, polyethylene glycol, polyurethane, N-(2-hydroxypropyl)methacrylamide, xanthane gum, and derivatives thereof, and/or wherein the one or more natural polymers are selected from the group consisting of pectins, chitin, chitosan, dextran, cellulose ethers, starch and derivatives thereof.

10. Artificial turf according to claim 2, wherein the ionomer resin comprises ionised repeating units, wherein said ionised repeating units comprise one or more ionic groups selected from the group consisting of sulphonate, phosphate, phosphonate, and carboxylate ionic groups.

11. Artificial turf according to claim 2, wherein the ionomer resin comprises acrylic acid comonomer, methacrylic acid comonomer or a combination of acrylic acid and methacrylic acid comonomers.

12. Artificial turf according to claim 2, wherein the ionomer resin comprises one or more from the group consisting of a random copolymer of poly(ethylene-co-(meth)acrylic) acid, a polyvinyl sulphonic acid or a sulphonated derivative of a poly(ether ether-ketone), wherein the ionomer resin may be neutralised.

13. Artificial turf according to claim 1, further comprising a functionalised polyethylene having one or more hydrophilic groups grafted on polyethylene, wherein the one or more hydrophilic groups are selected from the group consisting of anhydride groups, carboxylic acid groups, and hydroxyl groups.

14. Artificial turf according to claim 13, wherein the functionalised polyethylene is present in the blend in an amount of 1-10% by total weight of the blend.

15. Artificial turf according to claim 5, wherein the additives comprise one or more selected from the group consisting of compatibilisers, flame retardants, colouring agents, heat stabilisers, processing aids, antioxidants, UV-stabilisers, and pigments.

16. Artificial turf according to claim 1, wherein the synthetic turf filaments have a Young's modulus, as measured according to ISO 527, in the range of 1-50 cN/tex.

17. Artificial turf according to claim 1, wherein the blend comprises 65-99.5% by total weight of the blend of linear low-density polyethylene, and 0.5-35% by total weight of the blend of polyvinyl alcohol.

18. Artificial turf according to claim 1, wherein the synthetic turf filaments comprise 5% or less by total weight of the synthetic turf filaments of filler.

19. Artificial turf, comprising a synthetic backing, the synthetic backing comprises a blend, the blend comprises i) 65-99.5% by total weight of the blend of a polypropylene, and ii) 0.5-35% by total weight of the blend of a hydrophilic polymer, preferably the a hydrophilic polymer as defined in claim 9.

20. Artificial turf according to claim 19, wherein the artificial turf is in the form of a tile or carpet.

21. Artificial turf comprising synthetic turf filaments as defined in claim 1, and comprising a synthetic backing, the synthetic backing comprises a blend, the blend comprises i) 65-99.5% by total weight of the blend of a polypropylene, and ii) 0.5-35% by total weight of the blend of a hydrophilic polymer, preferably the hydrophilic polymer comprises one or more synthetic polymers and/or one or more natural polymers, wherein the one or more synthetic polymers are selected from the group consisting of polyvinyl alcohol, polyvinyl acetate, polyvinylpyrrolidone, polyacrylic acid, polyacrylamide, polyethylene glycol, polyurethane, N-(2-hydroxypropyl)methacrylamide, xanthan gum, and derivatives thereof, and/or wherein the one or more natural polymers are selected from the group consisting of pectins, chitin, chitosan, dextran, cellulose ethers, such as hydroxypropylcellulose, starch and derivatives thereof.

22. Synthetic backing material, comprising a blend as defined in claim 19.

23. Synthetic filament, comprising a blend as defined in claim 1.

24. Method of cooling artificial turf, comprising inserting a plurality of synthetic turf filaments as defined in claim 1 into artificial turf.

Description

EXAMPLES

Example 1

[0071] Extrusion experiments were performed on a 25 mm twin-screw extruder (L/D40). Different compounds were prepared and extruded into tapes of 15 mm width×1 mm thickness (w×t×∞). A first set of experiments (MY19001 to MY19008) was performed with LLDPE A, a LLDPE type C4 for grass production having a melt flow index as measured according to ISO 1133 at a load of 2.16 kg and at a temperature of 190° C. of 2.8 g/10 min, a density as measured according to ISO 1183 of 0.918 g/cm.sup.3, and a melting point as measured by DSC of 121° C., and 25 phr of extrudable PVOH (having a T.sub.g of 50-60° C.) with different compatibilising agents.

Example 2

[0072] Similar experiments as in Example 1 (MY19010 to MY19027) with lower PVOH content are performed, based on LLDPE B, a LLDPE type C4 for grass production having a melt flow index as measured according to ISO 1133 at a load of 2.16 kg and at a temperature of 190° C. of 1.0 g/10 min, a density as measured according to ISO 1183 of 0.918 g/cm.sup.3, and a melting point as measured by DSC of 121° C.

Example 3

[0073] A third set of samples was prepared (MY19028 to MY19039), equal to the set of Example 1, based on LLDPE B. Afterwards, SEM analysis was performed by a FEI Desktop Electron Microscope (see FIGS. 1 and 2). Samples were cross sectioned after cryogenic treatment by liquid nitrogen.

Example 4

[0074] Extrusion experiments were performed on a 25 mm twin-screw extruder (L/D40). Different compounds were prepared and extruded into tapes of 15 mm width×1 mm thickness (w×t×∞), then elongated 2.5 times into tapes of 7 mm width×500 μm thickness. A fourth set of experiments (MY19065 to MY19089) was performed with LLDPE C, a LLDPE type C4 for grass production having a melt flow index as measured according to ISO 1133 at a load of 2.16 kg and at a temperature of 190° C. of 2.0 g/10 min, a density as measured according to ISO 1183 of 0.918 g/cm.sup.3, and a melting point as measured by DSC of 122° C. and 8 phr of extrudable PVOH (having a T.sub.g of 50-60° C.) with different ionomers based on a copolymer of ethylene and methylacrylate.

Example 5

[0075] Extrusion experiments were performed on a 25 mm twin-screw extruder (L/D40). Different compounds were prepared and extruded into tapes of 15 mm width×1 mm thickness (w×t×∞), then elongated 4.5 times into tapes of 2.5 mm width×200 μm thickness. A fifth set of experiments (MY19093 to MY19117) was performed with LLDPE C and 8 phr of extrudable PVOH (having a T.sub.g of 50-60° C.) with different ionomers based on a copolymer of ethylene and methylacrylate.

[0076] Cyclic water absorption and release tests were performed on sample specimens of 1.00 m length by mass determination. Water absorption values of maximum 2 wt. % were reported (see FIG. 3).

Example 6

[0077] Extrusion experiments were performed on an artificial yarn extrusion production line. A set of experiments (TYR200003 to TYR200005) were performed with compounds similar to the fifth set, based on LLDPE C. These compounds were extruded into artificial grass fibres.

[0078] Cyclic water absorption and release tests are performed on sample specimen of 1.00 m length by mass determination. Water absorption values of maximum 4 wt. % were reported (see FIG. 4).