COMPOSITION FOR A SPORTS SURFACE, IN PARTICULAR FOR AN EQUESTRIAN SPORT, AND METHOD FOR PRODUCING SUCH A COMPOSITION

Abstract

The present invention relates to a composition for the production of a sports surface, especially for equestrian sports, advantageously comprising at least 50% by mass of sand, optionally at least one filler, and at most 10% by mass of an organic coating comprising at least one flexible polymer A having a tensile modulus less than or equal to 1 MPa at room temperature, as well as a process for manufacturing such a composition.

Claims

1-16. (canceled)

17. A composition, comprising: at least 50% by mass of sand; at most 10% by mass of an organic coating comprising at least one flexible polymer A having a tensile modulus less than or equal to 1 MPa at room temperature, and wherein the composition does not comprise waxes and oils.

18. The composition according to claim 17, comprising at least one filler.

19. The composition according to claim 17, wherein the polymer A has a glass transition temperature of less than or equal to 10 C.

20. The composition according to claim 17, wherein the polymer A has an elongation at break of greater than or equal to 300%.

21. The composition according to claim 17, wherein the polymer A has a degradation temperature greater than or equal to 180 C.

22. The composition according to claim 17, wherein the polymer A comprises repeat units resulting from the polymerization of at least one monomer comprising (meth)acrylate and/or (meth)acrylic functions.

23. The composition according to claim 17, wherein the polymer A is selected from the list consisting of: a (meth)acrylic acid (co)polymer, (co)polymer of a (meth)acrylic acid and of a repeat unit comprising one or more aromatic ring(s), an alkyl (meth)acrylate (co)polymer; a styrene-(meth)acrylic acid-alkyl (meth)acrylate copolymer, a copolymer of (meth)acrylic acid and styrene, a (co)polymer of (meth)acrylate and fatty alcohol, a (co)polymer of (meth)acrylate and of poly-terpene derivatives, or a mixture thereof.

24. The composition according to claim 17, comprising at least one polymer B selected from the list consisting of: polyisoprene, polyurethane, polysiloxane, polyacrylics, epoxyacrylates, poly-epoxy, polyesters; fluorinated polyacrylates; or a mixture thereof.

25. The composition according to claim 17, wherein the number-average distribution D50 of the sand is greater than or equal to 63 m.

26. The composition according to claim 18, wherein said at least one filler is selected from the list consisting of: synthetic fibers, plastic granules or rubber.

27. A process for manufacturing a composition for the production or refurbishing of a sports surface, comprising: mixing an aqueous emulsion of at least one polymer A with sand, said polymer A having a tensile modulus less than or equal to 1 MPa at room temperature, so as to form a first composition comprising at least 50% by mass of sand and not comprising waxes and oils; evaporating water from said first composition; obtaining the composition for the production or refurbishing of the sports surface, the composition comprising at most 10% by mass of an organic coating comprising at least said polymer A.

28. The manufacturing process according to claim 27, wherein the at least aqueous emulsion of at least one polymer A is mixed with sand and at least one filler.

29. The manufacturing process according to claim 27, wherein the mixing of the aqueous emulsion of at least one polymer A with sand is carried out at ambient temperature.

30. The manufacturing process according to claim 27, wherein the evaporating of water comprises passing the first composition over a fluidized-bed drying apparatus.

31. The manufacturing processing according to claim 27, comprising mixing the composition with a composition to be refurbished comprised in the sports surface thereby refurbishing the sports surface.

32. A process for refurbishing a sports surface comprising a composition to be refurbished comprising at least 50% by mass of sand, said process comprising: providing an aqueous emulsion of at least one polymer A having a tensile modulus of less than or equal to 1 MPa at room temperature; mixing said composition to be refurbished with said aqueous emulsion; evaporating water from the mixture; and obtaining a composition comprising at least 50% by mass of sand for the production of the sports surface, comprising at most 10% by mass of an organic coating comprising at least said polymer A and not comprising waxes and oils.

33. The process according to claim 32, wherein the composition to be refurbished comprises at least one filler.

34. A sports surface comprising a composition according to claim 1.

35. A sports surface comprising a composition obtained using the process of claim 27.

36. A sports surface comprising a composition obtained using the process of claim 32.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0121] The present invention will be better understood by reading the example embodiments described below, cited in a non-limiting manner.

Example 1

[0122] The composition comprises 67.45% by mass of silica sand with a grain size of 63 m to 500 m. The sand does not include any fines (size less than 63 m) and has a mass-average particle size distribution D50 of about 198 m. In addition, the composition comprises about 1.75% of a mixture of PP and PE fibers with lengths between 20 mm and 40 mm and about 27.90% by mass of PVC granules in the range of 3 mm to 5 mm. Finally, the composition comprises 2.90% by mass of an aqueous emulsion whose dry mass fraction is of the order of 60%. The polymer A is a copolymer of styrene, acrylic acid and butyl acrylate, whose Tg is of the order of 28 C. and the tensile or Young's modulus E is of the order of 0.2 MPa. The aqueous emulsion comprises 10% by mass (per to the total weight of the aqueous emulsion) of a wetting agent (for example Disperbyk P190). The elongation at break of the polymer A is of the order of 1100%. The sand, at ambient temperature (of the order of 20-25 C.) is first mixed with the PVC fibers and granules, then the aqueous emulsion, also at ambient temperature (of the order of 20-25 C.), is mixed with the pre-mixed sand and fillers. The mixture is dried so as to evaporate the water or left it at ambient temperature until the water evaporates. The mixture obtained is then emulsified again to destructure the agglomerates likely to form, at ambient temperature (around 20-25 C.) in order to form the final composition.

Example 2

[0123] The composition comprises 68.31% by mass of silica sand with a grain size of 63 m to 400 m. The sand does not include fines (size less than 63 m) and has a number-average distribution D50 of about 210 m. The composition further comprises about 1.82% of a mixture of PP and PE fibers with lengths between 20 mm and 40 mm and about 27.32% by mass of PVC granules in the range of 3 mm to 5 mm. Finally, the composition comprises 2.55% by mass of an aqueous emulsion whose dry mass fraction is of the order of 60%. The polymer A is a copolymer of styrene, acrylic acid and butyl acrylate, whose Tg is of the order of 28 C. and the tensile or Young's modulus E is of the order of 0.2 MPa. The aqueous emulsion comprises 10% by mass (per to the total weight of the aqueous emulsion) of a wetting agent (for example Disperbyk P190). The elongation at break of the polymer A is of the order of 1100%. The sand, at ambient temperature (of the order of 20-25 C.) is first mixed with the PVC fibers and granules, then the aqueous emulsion, also at ambient temperature (of the order of 20-25 C.), is mixed with the pre-mixed sand and fillers. The mixture is dried so as to evaporate the water or left at room temperature until the water evaporates. The mixture obtained is then emulsified again to destructure the agglomerates likely to form, at ambient temperature (around 20-25 C.) so as to form the final composition with the desired granular aspect.

Example 3

[0124] The composition comprises 87.49% by mass of silica sand with a grain size of 63 m to 400 m. The sand does not include fines (size less than 63 m) and has a number-average distribution D50 of about 210 m. The composition further comprises about 2.19% of a mixture of PP and PE fibers with lengths between 20 mm and 40 mm, and about 7.87% by mass of recycled and ground rubber granules of the order of 3 mm to 5 mm. Finally, the composition comprises 2.45% by mass of an aqueous emulsion whose dry mass fraction is of the order of 60%. The polymer A is a copolymer of styrene, acrylic acid and butyl acrylate, whose Tg is of the order of 28 C. and the tensile or Young's modulus E is of the order of 0.2 MPa. The aqueous emulsion comprises 10% by mass (per to the total weight of the aqueous emulsion) of a wetting agent (for example Disperbyk P190). The elongation at break of the polymer A is of the order of 1100%. The sand, at ambient temperature (of the order of 20-25 C.) is first mixed with the fibers and granules, then the aqueous emulsion, also at ambient temperature (of the order of 20-25 C.), is mixed with the pre-mixed sand and fillers. The mixture is dried so as to evaporate the water or left at room temperature until the water evaporates. The mixture obtained is then emulsified again to destructure the agglomerates likely to form, at ambient temperature (around 20-25 C.) so as to form the final composition with the desired granular aspect.

Example 4

[0125] The composition comprises 96.44% by mass of silica sand with a grain size of 63 m to 400 m. The sand does not include fines (size less than 63 m) and has a number-average distribution D50 of about 210 m. In addition, the composition comprises approximately 1.92% of a mixture of PP and PE fibers with lengths between 20 mm and 40 mm (without PVC granules). Finally, the composition comprises 1.64% by mass of an aqueous emulsion with a dry mass fraction of the order of 60%. The polymer A is a copolymer of styrene and acrylic acid, whose Tg is of the order of 8 C. and the tensile or Young's modulus E is of the order of 0.4 MPa. The aqueous emulsion comprises 10% by mass (per to the total weight of the aqueous emulsion) of a wetting agent (for example Disperbyk P190). The elongation at break of the polymer A is of the order of 1100%. The sand, at ambient temperature (of the order of 20-25 C.) is first mixed with the fibers and then the aqueous emulsion, also at ambient temperature (of the order of 20-25 C.), is mixed with the sand and the pre-mixed fibers. The mixture is dried so as to evaporate the water or left at ambient temperature until the water evaporates. The mixture obtained is then broken up again to destructure the agglomerates that may form, at ambient temperature (around 20-25 C.) so as to form the final composition with the desired granular appearance.

[0126] The composition of Example 4 is intended for sports surfaces requiring less deformability.

[0127] The energy return (rebound), ground sinking (cohesion) and damping properties of the final composition according to Example 1) were evaluated in comparison with a control composition 1 comprising sand (about 85% by mass of the total mass of the final composition), wax with 20% mineral oil (about 5% by mass of the total mass of the final composition), fibers of lengths between 20 and 40 mm, and PVC granules (about 10% by mass of the total mass of the final composition).

[0128] The instrumented shock tests, with an energy of 117 joules (allowing the measurement of the deceleration on the ground of a mass in free fall, by accelerometric sensors, to determine the speed and movement of the mass, before and after impact, by successive integrations of the deceleration), carried out under conditions simulating the impact of horses, were performed on a sports surface comprising the different compositions according to the invention and a control composition, the latter having a thickness of 13 cm, and comprising a first layer 4 cm thick highly compacted with a 1500 g rammer, then a second layer 6 cm thick compacted less strongly than the first layer and a third finishing layer of about 3 cm slightly scratched to obtain the surface swelling.

Return of Energy Transmitted During Hoof Impact in %.

[0129]

TABLE-US-00001 TABLE 1 Temperature of the composition 9 C. 17 C. 29 C. 40 C. Composition 20% 15% 11% 11% example 1 Control 11% 9% 8.3% composition

[0130] Ground Depression on Hoof Impact in Mm

TABLE-US-00002 TABLE 2 Temperature of the composition 9 C. 17 C. 29 C. 40 C. Composition 21.1 mm 24.2 mm 29.6 mm 30.1 mm example 1 Control 23 mm 31.7 mm 40.4 mm composition

[0131] Damping: Maximum Force Felt by the Horse (Newtons)

TABLE-US-00003 TABLE 3 Temperature of the composition 9 C. 17 C. 29 C. 40 C. Composition 8109 N 7233 N 6606 N 6590 n example 1 Control 6995 N 6430 N 5705 N composition
Shock Test Performed with a Clegg Hammer Device.

TABLE-US-00004 TABLE 4 Values of 60-70 Gm Temperatures of the compositions tested ( C.) 5 C. 2.3 C. 14 C. 27 C. 44 C. 63 C. Control 170 Gm 118 Gm 110 Gm 64 Gm 42 Gm 37 Gm Composition 2 Composition of 80 Gm 57 Gm 55 Gm 56 Gm 54 Gm 41 Gm Example 2

[0132] The control composition 2 comprises sand (about 67.51% by mass of the total mass of the final composition), wax with 20% mineral oil (about 3.69% by mass of the total mass of the final composition), fibers of lengths between 20 and 40 mm (1.80% by mass of the total mass of the final composition), and PVC granules (about 27% by mass of the total mass of the final composition).

[0133] The Clegg Hammer Test is a device with a mass of 2500 g classically used to evaluate sports surfaces for animals. This device comprises an accelerometer to record the deceleration experienced at the moment of impact. This deceleration is expressed in Gm, which increases with the hardness of the material.

[0134] The composition according to Example 1 provides better energy return than the control composition. In addition, the composition according to Example 1 is less sensitive to temperature variations for ground sinking than the control composition, the amplitude of deformation between 9 C. and 40 C. is also lower (less than 10 mm variation for the composition according to Example 1 against almost 20 mm for the control composition). Finally, the composition according to Example 1 offers a damping of the same order as that offered by the control composition and this in a homogeneous manner from 9 C. to 40 C.

[0135] The composition according to Example 1 provides better elasticity. The sports surface with such a composition is easier to regain its position after impact. The energy return is higher than the values obtained for the control composition. The overall properties reflect a lower sensitivity of the composition in Example 1 to temperature with a lower deformation providing a less stressful and more constant contact for the horse.

[0136] Finally, the water permeability measured over a height of 10 cm of composition of Example 1 after compaction with a load of 1.5 MPa is 0.17 mm/sec, i.e. 612 mm of water per hour (value measured by monitoring the time necessary for migration, within a graduated cylinder, of a water height of 30 mm). This permeability value allows the composition of Example 1 to avoid water retention on the surface, thus ensuring a good draining effect.

Comparative Example 5

[0137] A composition comprising 100 parts of silica sand having a sand grain size between 63 m and 400 m. The sand does not include fines (size less than 63 m) and has a number-average distribution D50 of about 210 m. In addition, the composition comprises about 1.8 parts of a mixture of PP and PE fibers with lengths between 20 mm and 40 mm (without PVC granules). Finally, the composition comprises 2.5 parts of an aqueous emulsion whose dry mass fraction is of the order of 50%. The polymer is a copolymer of styrene and acrylic acid, whose Tg is of the order of 4 C. and the tensile or Young's modulus E is of the order of 3.2 MPa (at 23 C.). The aqueous emulsion comprises 10% by mass (based on the total weight of the aqueous emulsion) of a wetting agent (for example Disperbyk P190).

Examples 6 and 7

[0138] The compositions are identical to the composition in Comparative Example 5 with the difference that for Example 6, the polymer A is the same as in Example 1, and for Example 7, the polymer A is the same as in Example 4. In the internal cohesion test consisting of observing the state of the composition following a fall from a height of 40 cm of a ball compacted in said composition, it is observed that the loops are integral, without loss of cohesion between the sand and the fillers.

[0139] The compositions of Examples 6 and 7 give elastic surfaces with good mobility, with a satisfactory bond between the sand and the fibers so that the soil does not leak under the impact of the hooves. In comparison, the composition of Comparative Example 5 shows a strong separation between sand and fillers, making the surface unsuitable for use as it is much more leaking under the impact of the hooves. The cohesion between the sand and the loads is too weak. In the internal cohesion test, it is observed that the compacted ball is burst without cohesion between the sand and the loads.

[0140] Instrumented impact tests were performed on equestrian surfaces including the compositions of Examples 6 and 7. These tests involve the fall of a mass of 33 kg and developing an energy of 272 kJ with an angle of 12 with respect to the vertical of the tested surface. These tests simulate the impact of the horses' hooves on the surface. The results are reported in Table 5 and are in accordance with the recommendations of the sports federations.

TABLE-US-00005 TABLE 5 Example 6 Example 7 T C. 23 C. 35 C. 50 C. 23 C. 35 C. 50 C. Strike: damping capacity in kN 5.77 12.49 11.5 14.6 13.6 12.6 Response: energy return %. 46 59 63 48 57 56 Digging: firmness on contact in g 120 84 69 95 83 77 Leakage: hoof slippage in mm 5.85 5.9 6.25 6.25 6.3 6.6