Composition for a water permeable court surface and method for production of same

Abstract

A water permeable court surface comprises a porous substrate (5) on which there is a porous rubber shock layer (3) on which is at least one layer (1,2) of an acrylic composition, wherein the acrylic composition comprises a two pack water based polyurethane.

Claims

1. A composite for a water permeable court surface which comprises a porous substrate on which there is a porous rubber shock layer on which is at least one layer of an acrylic composition, wherein the acrylic composition comprises a two part water based polyurethane and wherein the acrylic composition comprises a first component which comprises an organic solvent-free aqueous dispersion of a copolymer based on an aliphatic polycarbonate polyurethane and a polyacrylate.

2. The composite according to claim 1, wherein the first component is blended with a second component, which is a water miscible polyiscocyanate.

3. The composite of claim 2, wherein the first component and the second component are blended with a water based acrylic.

4. The composite of claim 1, wherein the porous substrate is of a bituminous or tar derived material.

5. The composite of claim 1, wherein the rubber shock layer is formed of rubber granules bonded together by a polyurethane binder.

6. The composite of claim 5, wherein the rubber granules have a granule size having a diameter of from about 1 to about 3 mm.

7. The composite of claim 1, wherein the rubber shock layer has a thickness of about 4 mm to about 6 mm.

8. The composite of claim 1, wherein the rubber shock layer is fixed to the substrate by means of an adhesive.

9. The composite of claim 8, wherein the adhesive is a two part polyurethane adhesive.

10. The composite of claim 8, wherein the adhesive is applied in the form of beads.

11. The composite of claim 10, wherein a gap is provided between the beads of adhesive are about 10 mm wide.

12. The composite of claim 1, wherein the rubber shock layer is treated with a detergent.

13. The composite of claim 12, wherein the detergent comprises a blend of sodium metasilicate, anionic and non-ionic surfactants, sequestering agent, solubiliser and glycol ether.

14. The composite of claim 1, wherein the acrylic composition is spray applied in two applications.

15. The composite of claim 14, wherein the acrylic composition applied in a first application contains about 20% to about 30% acrylic by weight.

16. The composite of claim 14, wherein a final coat comprises about 40% to about 50% acrylic by weight.

17. A method for production of the composite of claim 1 for a water permeable court surface which comprises the steps of providing a porous substrate, providing a porous rubber shock layer on top of the porous substrate and providing at least one layer of acrylic composition on top of the porous rubber shock layer, wherein the acrylic composition comprises a two pack water based polyurethane.

18. The method of claim 17, wherein the method comprises the step of fixing a rubber shock layer to the substrate by means of an adhesive.

19. The method of claim 18, wherein the method comprises the step of applying adhesive in bead form whereby beads of glue are formed in substantially parallel lines with gaps in between to allow water to pass therethrough.

20. The method of claim 18, wherein the method does not include the step of applying adhesive by means of dot gluing.

21. The method of claim 17, wherein the method comprises the step of treating the rubber shock layer with a detergent.

22. The method of claim 17, wherein the method includes the step of blending the two part water based polyurethane with an acrylic resin.

23. The method of claim 17, wherein the method includes the step of applying the acrylic composition by spraying.

24. The method of claim 17, wherein the step of applying the acrylic composition is applied in two applications.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will now be further described with reference to the accompanying drawings in which:

(2) FIG. 1 shows a diagram of an embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

(3) It will be appreciated that aspects, embodiments and preferred features of the invention have been described herein in a way that allows the specification to be written in a clear and concise way. However, unless circumstances clearly dictate otherwise, aspects, embodiments and preferred features can be variously combined or separated in accordance with the invention. Thus, preferably, the invention provides a device having features of a combination of two or more, three or more, or four or more of the aspects described herein. In a preferred embodiment, a device in accordance with the invention comprises all aspects of the invention.

(4) Within the context of this specification, the word about means plus or minus 20%, more preferably plus or minus 10%, even more preferably plus or minus 5%, most preferably plus or minus 2%.

(5) Within the context of this specification, the word substantially means preferably at least 90%, more preferably 95%, even more preferably 98%, most preferably 99%.

(6) Within the context of this specification, the word comprises means includes, among other things and should not be construed to mean consists of only.

(7) The invention provides a water permeable court surface which comprises a porous substrate on which there is a porous rubber shock layer on top of which is at least one layer of acrylic composition. According to the invention, the structure of the surface combines the advantages of a porous textured surface and a cushioned surface. This provides the advantage that the invention can be used to provide a surface for a tennis court and/or other sports, because it provides a level of grip, ball speed and comfort comparable to traditional cushioned acrylic surfaces but with the added advantage of porosity for play in wet weather. Furthermore, many tennis courts are covered with an air dome to protect from the weather. A common problem with these domes is that they collect condensation which then drips onto the surface causing water retention to some areas. With the surface of the invention water is absorbed into the surface maintaining an even grip across the entire court.

(8) As shown in FIG. 1, an embodiment of the invention comprises a porous substrate (5) on which there is a porous rubber shock layer (3) on top of which is at least one layer of acrylic composition (1) (2).

(9) Preferably, the porous substrate (5) is of a bituminous or tar derived material of the type currently used.

(10) The rubber shock layer (3) is of rubber granules bonded together by a polyurethane binder. The rubber granules have a granule size having a diameter of from about 2 mm. The rubber shock layer has a thickness of about 5 mm.

(11) The rubber is a conventional rubber material and contains conventional additives such as fillers etc.

(12) The rubber shock layer is fixed to the substrate by means of a two part polyurethane adhesive (4) having a low viscosity to enable the correct flow to be achieved through the application device and applied in bead form. The beads of glue (4) are formed in parallel lines with gaps in between to allow water to pass therethrough. The beads of adhesive (4) and the gaps between the beads of adhesive are about 10 mm wide.

(13) A specially designed piece of equipment is used for applying and distributing the adhesive. The equipment comprises a wheeled trolley with a trough to contain the adhesive which pivots and has a plurality of holes defined at one end. When wheeled across the surface and angled correctly the adhesive pours through the holes forming beads of adhesive on the surface.

(14) After the adhesive has set, the rubber shock layer is treated with a detergent which comprises a blend of sodium metasilicate, anionic and non-ionic surfactants, sequestering agent, solubiliser and glycol ether. It has been found that this is critical as it breaks down lubricating agents present in the rubber, which if untreated prevent adhesion of the subsequent coatings.

(15) As standard acrylic coatings commonly used on tennis courts will not adhere to the rubber mat, because of their chemical properties, a specially formulated two part water based polyurethane composition is used. This composition has a first component which comprises an organic solvent-free aqueous dispersion of copolymer based on an aliphatic polycarbonate polyurethane and a polyacrylate, and a second component comprising a water miscible polyiscocyanate which is blended with the first component. The composition is further blended with an acrylic resin and spray applied in two applications.

(16) The first application contains about 20% to about 30% acrylic by weight. In contrast, a higher acrylic content of about 40% to about 50% acrylic by weight is provided in the final application to provide the preferred playing characteristics.

EXAMPLES

Example 1

(17) A taber abrasion test was carried out.

(18) A taber abrasion test is a test to determine a plastic surface's resistance to abrasion.

(19) A comparative test between a surface according to the invention as described above (Formula (a)) and a surface described in GB2346331 (Formula (b)) were tested: Taber abrasion (CS 17) after 1000 cycles (a): Abrasion Result=24 mg weight loss (b): Abrasion Result=37 mg weight loss

(20) The results clearly showed that the surface of the invention performed better than the surface described in GB2346331.

Example 2

(21) A second comparative test was carried out.

(22) One sample of rubber mat was coated according to the invention and a second rubber mat was coated as described in GB2346331.

(23) Once the surfaces were fully cured, they were rubbed together face to face constantly for such a period of time that it was possible to see that the surface coated as described in GB2346331 was wearing while the surface coated according to the invention was still intact.

(24) This demonstrated that the surface according to the invention was remarkably more resistant to wear.

(25) The above described embodiments have been given by way of example only, and the skilled reader will naturally appreciate that many variations could be made thereto without departing from the scope of the invention.