WO2015077376A1

WO2015077376A1 - Improved modified sand sports surfaces

Info

Publication number: WO2015077376A1
Application number: PCT/US2014/066468
Authority: WO
Inventors: Nicholas Attwood; Steve I. LAW
Original assignee: Equestrian Surfaces Inc
Current assignee: Equestrian Surfaces Inc
Priority date: 2013-11-19
Filing date: 2014-11-19
Publication date: 2015-05-28
Anticipated expiration: 2016-05-19

Abstract

The wear life of coated artificial sports surfaces, such as equestrian surfaces based on coated sand, can be improved by incorporating into the coating, more specifically at the interface between coating and particulate base material, a coupling agent. The coated sport surfaces include a compound comprising at least a silane moiety that is capable of transforming to a silanol which, it is believed, then reacts with hydroxyl groups on the substrate surface, such as those found on a silica sand surface, thereby improving the coupling or adhesion performance of the organic coating compound on the substrate surface.

Description

IMPROVED MODIFIED SAND SPORTS SURFACES

Priority Statement

[0001] This application claims the benefit of priority from U.S. Prov. Pat. Appl. No. 61/906,401, filed November 19, 2013. This application, in its entirety, is incorporated herein by reference.

Background

[0002] This invention relates to the formulation, manufacture and use of a sports and recreation surface designed to be laid over a more substantive underlayer, to provide a relatively loose but cohesive, cushioned surface, particularly suitable for equestrian use.

[0003] The disclosure relates to the formulation, manufacture and use of improved surfacing materials that provide increased wear life. It is anticipated that these materials when used as equestrian surfacing materials will be particularly useful as a ground cover/flooring for a wide range of equestrian activities and sports, particularly as applied to horse training and race tracks, riding arenas, round pens and walkers. It is further anticipated that these equestrian surfacing materials would be suitable for use during training, thoroughbred racing, show jumping, dressage, English pleasure riding and western pleasure riding. Furthermore, the current invention provides for an improved formulation with improved properties over prior art formulations, such as those disclosed in U.S. Pat.

No. 8,324,306 ("the '306 patent"), the contents of which are incorporated herein, in their entirety, by reference. [0004] At present, there are no universal recommendations for the perfect riding arena surfacing or surfacing material but the general goals include providing a surface that:

• provides cushioning to reduce concussion on horse's legs and reduce the

chance of injuries during a fall;

• has sufficient cohesion between the particles to provide adequate traction;

• tends to suppress dust generation;

• is not unduly abrasive or damaging to a horse's hooves either through abrasion or agglomeration within and around the hoof;

• that maintains an acceptable combination of properties over the temperature and precipitation ranges typically experienced throughout the year at the installation site;

• does not require significant or excessive maintenance; and

• over a significant lifetime, provides good value.

[0005] First generation or conventional footing materials included, for example, sand, soil, stone dust, wood particles, rubber particles, stall waste and combinations thereof. These products are deficient in at least one, often many performance parameters. For instance, certain of these conventional footing materials have to be kept wet to maintain sufficient particle-to-particle adhesion and avoid being blown away or generating dust in the atmosphere above the riding surface when ridden upon. Where watering is not an option, the materials can be coated in a low volatility oil-based product which helps to bind particles together and prevent dust generation, but provides for little cohesion and cushioning. The oil coatings, however, tend to have a limited life span and tend to either evaporate or be worn off the riding surface such that the advantageous properties are degraded or lost over a short period of time.

[0006] Second generation products were developed to address some of the deficiencies of the first generation products, but still do not satisfy all of the necessary attributes. Such a surface material is described in U.S. Patent No. 5,961,389, the contents of which are incorporated herein, in their entirety, by reference. Such second generation surfaces generally comprise sand or other particulate material, combined with a waxy substance that is said to somewhat bind the particles together so that dust generation is suppressed. The wax also tends to give the whole surface a texture that resembles a watered conventional footing such that regular watering may be reduced or eliminated.

[0007] However such waxes tend to exhibit poor temperature stability, their viscosity rapidly changing with temperature such that at high ambient temperatures the material becomes sticky and the 'going' is made drastically softer. Conversely at low ambient temperatures the wax viscosity increases markedly, and the 'going' becomes much harder. Furthermore, the properties of such surfaces can deteriorate over time depending on ambient conditions and the level of after-care applied. It has also been determined that in some instances, portions of the wax coating become detached from the underlying particulate carrier, such that the particulate carrier becomes uncoated and the footing material loses cohesion, and can create dust due to airborne particles.

[0008] An improvement over such second generation wax-based surfaces was disclosed by the applicant in the '306 patent. These surfacing materials are based on sand that is coated with a polymer or combinations of polymer and oil, and fibers. The use of polymers to coat sand particles provides for a considerably more consistent reaction to ambient temperature. Additionally, the use of a polymer with viscoelastic properties provides for considerably more cushioning and rebound than the wax -based materials. However, it has been determined that the polymer/oil coating, particularly in the presence of moisture, can, over time, detach from the sand particles leaving them essentially uncoated and the advantageous properties of the surfacing material degraded.

[0009] The feature of loss of coating from an equestrian surface is a particular problem facing these types of footing materials. For instance, wax coated footing materials are used in a number of commercial horse race tracks around the world, but have been plagued with longevity problems. The cohesive properties provided by the wax coating can be lost over time, and this loss can be exacerbated by extremes of temperature and moisture. It is thought that the wax coating detaches, under the action of abrasion wear, from the particulate, usually sand and filler material, often fibers, leaving essentially uncoated sand and filler. The desirable properties of cohesion, low dust generation, and cushioning are consequently degraded or lost, and the material has to be recoated to bring it back to its original properties. In addition the uncoated sand tends to sink to the base of the riding surface, providing a less water permeable layer, resulting in drainage problems.

Summary of the Invention

[0010] The present invention is concerned with improving the usable life of such coated surfacing materials, by providing coatings that adhere to the particulate material for significantly longer periods of time, even in extremes of weather.

[0011] It has been discovered that the wear life of coated artificial sports surfaces, such as equestrian surfaces based on coated sand, can be significantly improved by incorporating into the coating, more specifically at the interface between coating and particulate base material, a compound comprising a silane moiety that is capable of transforming to a silanol which can then react with hydroxyl groups on a substrate surface, such as those on a silica sand surface, ultimately leading to stable covalent bonding. These steps lead to improved coupling or adhesion of the coating compound to the substrate surface.

[0012] The invention encompasses surfacing compositions comprising from 80 to 98 wt sand; from 1 to 10 wt of an organic coating selected from a group consisting of coating polymers, coating waxes and mixtures, blends and combinations thereof; from 0.1 to 5 wt of fibers, preferably having a staple length of 3.2 to 25.4 mm and an average fiber diameter of 0.5 to 12 Denier; and at least 0.002 wt of a coupling agent and methods of making such compositions from both new and used materials. The coupling agent can be selected from monomelic silanes, polymeric silanes, and mixtures and combinations thereof. Alkylalkoxysilanes, particularly those including one or more trimethoxysilane or

triethoxysilane functional groups, have proven effective as coupling agents. The sand used in such surfacing compositions preferably includes a major portion of the sand grains that are classified as angular or sub-angular. A wide range of fibers may be utilized including, for example, rayons, nylons, polyesters, acrylics, polypropylenes, polyethylenes and

combinations and mixtures thereof. The organic coating can include one or more

components selected from a group including waxes, poly- a-olef ins, ethylene vinyl acetates (EVA), polyamides, polybutylenes (PB), polystyrenes (PS), polyvinylchlorides (PVC), polyvinylidenechlorides, acrylonitrile butadiene styrenes (ABS), acrylics, polyisobutylenes, natural rubber, polyethylenes, polypropylenes, and mixtures and combinations thereof.

[0013] When a coating polymer is utilized in the surfacing composition, it is preferred that the polymer or polymer blend exhibit both a softening point of 80 to 165° C, as measured according to ASTM D36-06 or DIN EN 1427, and a melt viscosity at 190° C. of 2 to 120 Pa-s, as measured according to ASTM D3236-88 or DIN 53 019. If one or more oils is included in the surfacing composition, it is preferred that the oil or blend exhibit a viscosity at 40° C. of 20 to 100 centistokes as measured according to ASTM D445 and that wherein the oil or blend is suitable for forming a dispersion, e.g. , suspension, emulsion or solution, with the coupling agent. The oil(s) may be selected from a group including mineral oils, paraffinic oils, aromatic oils, naphthenic oils, and mixtures and combinations thereof.

[0014] The invention encompasses methods of manufacturing such surfacing compositions, a method according to a first embodiment including the steps of heating a charge of dry, cleaned sand to a temperature above a softening point temperature of the organic coating that is to be applied; distributing the organic coating and the coupling agent throughout the heated sand and onto the surfaces of the sand grains while maintaining the sand at a temperature above the softening point temperature of the organic coating to form a coated mixture; and distributing the fibers throughout the coated mixture to form the surfacing composition. As will be appreciated, in alternative embodiments of the method, the fibers can be distributed in the heated sand before application of the organic coating or distributed simultaneously with the organic coating.

[0015] A method of manufacturing the surfacing composition according to a second embodiment includes the steps of heating a charge of dry, cleaned sand to a temperature above a softening point temperature of the organic coating; distributing the coupling agent throughout the heated sand to obtain pretreated sand; distributing the organic coating throughout pretreated sand while maintaining the pretreated sand at a temperature above the softening point temperature of the organic coating to form a coated mixture; and distributing the fibers throughout the coated mixture to form the surfacing composition. As will be appreciated, in alternative embodiments of the method, the fibers can be distributed in the heated sand before application of the organic coating or distributed simultaneously with the organic coating.

[0016] A method of manufacturing the surfacing composition according to a third embodiment, specifically rejuvenating a worn out or otherwise degrades surfacing material, includes the steps of identifying a quantity, volume or charge of the degraded surfacing composition, typically a composition that originally comprised from 80 to 98 wt sand, from 1 to 10 wt of an organic coating and from 0.1 to 5 wt of fibers; and distributing the coupling agent throughout the degraded surfacing composition to rejuvenate the degraded surfacing composition. The coupling agent may be combined with an oil, a coating polymer or a blend thereof to form a dispersion that is, in turn, distributed throughout the degraded surfacing compound, thereby improving the adhesion between the organic coating and the sand particles and improving the desired surfacing material properties.

[0017] The coupling agent may be combined with the oil, coating polymer or blend thereof in various ratios including, for example, from 1 :1 to 1:50, from 1 :1 to 1 :10 or from 1 :1 to 1:5 depending on the particular components selected and the degree of degradation of the used surfacing material. If an oil is used, it may be selected from a group consisting of mineral oils, paraffinic oils, aromatic oils, naphthenic oils, and mixtures and combinations thereof. If a coating polymer is used, low viscosity polymers would be preferred, particularly when working under ambient temperature conditions including, for example, polyisobutylene (PIB). As will be appreciated, depending on the state of the degraded surfacing material, the organic coating used and the ambient conditions, the rejuvenating process may include a step of heating the degraded surfacing material to aid in the distribution of the coupling agent and, at temperatures above a softening point temperature of the organic coating to aid in the redistribution and attachment of the organic coating to the sand grains.

Description of the Drawings

[0018] Example embodiments of compositions and methods that could be used for practicing the invention are described more fully below with reference to the attached drawings in which:

[0019] FIGS. 1 and 2 illustrate the condition of the surfacing material of Sample 1 before and after the wet wear test procedure;

[0020] FIGS. 3 and 4 illustrate the condition of the surfacing material of Sample 2 before and after the wet wear test procedure;

[0021] FIGS. 5 and 6 illustrate the condition of the surfacing material of Sample 3 before and after the wet wear test procedure;

[0022] FIGS. 7 and 8 illustrate the condition of the surfacing material of Sample 4 before and after the wet wear test procedure;

[0023] FIGS. 9 and 10 illustrate the condition of the surfacing material of Sample 5 before and after the wet wear test procedure;

[0024] FIGS. 11 and 12 illustrate the condition of the surfacing material of Sample 6 before and after the wet wear test procedure;

[0025] FIG. 13 and 14 illustrate the condition of the surfacing material of Sample 7 before and after the wet wear test procedure; [0026] FIG. 15 illustrates the condition of "spent" surfacing material from which samples 8 and 9 were drawn;

[0027] FIGS. 16 and 17 illustrate the condition of the surfacing material of Sample 8 before and after the wet wear test procedure;

[0028] FIGS. 18 and 19 illustrate the condition of the surfacing material of Sample 9 before and after the wet wear test procedure;

[0029] FIGS. 20-24 illustrate the condition of various embodiments of a degraded surfacing material that has been rejuvenated according to the methods of the invention and then subjected to the wet wear test procedure;

[0030] It should be noted that these figures are intended to illustrate the general characteristics of methods and compositions according to the invention with reference to certain example embodiments and thereby supplement the detailed written description provided below. These drawings are not, however, to scale and may not precisely reflect the characteristics of any given embodiment, and should not be interpreted as defining or limiting the range of values or properties of embodiments within the scope of this invention.

Detailed Description

[0031] As noted above, the wear life of coated artificial sports surfaces can be significantly improved by incorporating into the coating, more specifically at the interface between coating and particulate base material, a compound comprising a silane moiety. Such compounds are capable of transforming to a silanol which, in turn, can react with hydroxyl groups on a substrate surface, such as a silica sand surface, to provide improved coupling or adhesion of the coating compound to the substrate surface. [0032] Further, if another part of the coupling compound has a structure that is compatible with the coating, either through chemical reaction, or simple chemical compatibility, then the coating tends to be coupleed or coupled to the substrate through these reaction(s) and/or interaction(s). Similar coupling can, for example, take place between the coating and other additives such as rubber particles, fibers, etc. The coupling compound can be applied to the substrate before the coating operation.

[0033] Surprisingly the coupling compound can also be formulated with the coating so that it is applied at the time of application of coating to the substrate. Even though the coupling compound is not applied directly to the substrate surface, it nevertheless performs the function of coupling the coating to the substrate surface. Even more surprising, it is possible to apply the coupling compound to a tired, or spent surface, either singly or as part of a rejuvenating compound during a rejuvenation process to improve the durability of the coating of the rejuvenated material.

[0034] The coupling compound can be monomeric or polymeric. Examples of suitable monomeric coupling compounds include, without limitation, octyltrimethoxysilane (such as Momentive's SILQUEST A- 137) and vinylpropyltriethoxysilane (such as Evonik's DYNASYLAN 6598). An example of a suitable polymeric coupling compound is silane- modified polyalphaolefin such as those supplied commercially by Evonik as

VESTOPLAST 206. Alternative silane modified polymers include the TEROSTAT range supplied by Henkel.

[0035] The use of so-called coupling agents with coated sports surfacing materials has been mentioned in, for example, U.S. Pub. Pat. Appl. No. 2006/0100342, the contents of which are incorporated herein, in their entirety, by reference. This reference does not, however, teach or disclose the required functional nature of the coupling agent necessary for use with a particular coating composition and substrate or the use of such coupling or coupling agents to repair or rejuvenate a spent sports surface.

[0036] The use of such compounds results in significantly improved wear resistance in coated sports surfaces, particularly equestrian riding surfaces. The coating on typical equestrian riding surfaces is based on hydrophobic compounds such as an oil or wax, for example as described in WO 99/19567, the contents of which are incorporated herein, in their entirety, by reference, or a hydrophobic polymer such as a polyolefin as described, for example, in the '306 patent. One part of the coupling compound therefore needs to be either chemically compatible with this type of coating, or capable of undergoing reaction with this type of coating.

[0037] It will be appreciated by those skilled in the art that a number of moieties are available, hence a number of possible products incorporating one or more of the moieties could be prepared in order to satisfy the conditions inherent in a particular mixture of substrate materials. For example, the product VESTOPLAST 206 has as one part of its structure a polyalphaolefin (poly-a-olefin) which is entirely compatible with typical hydrophobic polymeric and/or wax -based equestrian surface coatings. When used either as an additive in a coating, or as part of a pre-treatment before coating, the resistance of the coating to detachment from the substrate is significantly improved. This results in improved wear resistance, particularly in wet or moist conditions.

[0038] Wear resistance of artificial equestrian riding surfaces can be measured by subjecting the material to repeated abrasion in wet conditions. This simulates actual use conditions where the surface, often wet through rain or dew formation is ridden upon by horses, which creates abrasive conditions on the surface. In addition, in order to loosen the surface and make its height even, the surface is regularly harrowed by either a 'static' harrow where special tines are simply pulled through the surface or a power harrow which incorporates rotating tines or blades for agitating the surface material. Repeated application of the harrowing operations can contribute to the breakdown of a coating.

[0039] Although the breakdown of a coated surface under real use conditions can typically take several months or even several years, this time frame is not particularly helpful for product development. Accelerated testing is, therefore, a conventional and extremely useful tool in the development and assessment of many new materials and products.

Consequently, the long term break-down of a riding surface can be simulated by imposing greater loading rates and/or more sustained abrasion to the material to produce accelerated wear.

[0040] Such a test has been developed based on continuous tumbling for evaluating the wear resistance performance of a prospective or existing riding surface material. The test involves placing a sample of footing material contained within a glass jar is tumbled continuously in the presence of water by rotating the jar on a roller mixer. Samples (typically about 25 g weight) are placed into suitable receptacles including, for example, glass jars (6 cm diameter x 8 cm height), along with four 15 mm diameter glass balls and a volume of water having a mass equal to that of the footing material under test.

[0041] The jars are then sealed and placed onto a bottle roller, and rotated at 1 revolution per second for a total of 10,800 revolutions over a three-hour testing period. Whilst this testing period has not been theoretically related to any particular period of real- world use of such surfacing materials, the empirical evidence reveals that the degradation reflected in the samples of the conventional polymer- and wax-coated surface materials correlated well with the degradation seen in samples pulled from spent track surfaces. After the target number of revolutions has been achieved, the material is then removed and dried in a circulating oven at 40° C. The resulting material is then visually inspected, and observations noted.

[0042] In all the following examples sand with particle size distribution, measured by sieve analysis, given in Table 1 was used.

TABLE 1. Sieve Analysis of Sand Comparative Example 1 : Preparation of prior art material - Sample 1

[0043] An amorphous polyalphaolefin (APAO) polymer was melted and mixed with a mineral oil, which mixture was then coated onto sand and fibers according to the teachings in prior art, contained for example in the '306 patent, in the following proportions: 1.8% APAO, 1.8% mineral oil, 1.5% polypropylene staple fibers, 94.9% sand. The material was then allowed to cool before measurement. The material was a reasonably cohesive, reasonably soft material.

Comparative Example 2: Preparation of prior art material - Sample 2

[0044] A petroleum hydrocarbon wax product designed as an equestrian riding surface coating material was coated onto dry sand and polypropylene fibers by mixing at above ambient temperature, according to prior art taught in, for example, WO 2008/024523, the contents of which are incorporated herein, in their entirety, by reference, in the following proportions: 4% hydrocarbon wax, 1.5% polyester staple fibers, 94.5% sand. The material was then allowed to cool before measurement. The material was a reasonably cohesive, reasonably soft material.

Comparative Example 3: Preparation of prior art material - Sample 3

[0045] A hydrocarbon oil product designed to be used as a dust suppressant on equestrian riding surfaces was coated onto sand and fibers by mixing the components at ambient temperature, in the following proportions: 2% hydrocarbon oil, 1.5% polyester fibers, the balance dry sand. The material was then allowed to cool before measurement. The material was a reasonably cohesive, reasonably soft material. Present Invention Example 1 : Preparation of material of the present invention - Sample 4

[0046] The amorphous polyalphaolefin polymer used in Comparative Example 1 was melted and mixed with a mineral oil, VESTOPLAST 206 (a silane-modified polyalphaolefin), and polypropylene fibers in the following proportions: 1.8% APAO, 1.8% mineral oil, 0.04% VESTOPLAST 206, 1.5% polypropylene staple fibers, and the balance dry sand. The material was then allowed to cool before measurement. The material was a reasonably cohesive, reasonably soft material.

Present Invention Example 2: Preparation of material of the present invention - Sample 5

[0047] The petroleum hydrocarbon wax used in the preparation of Sample 2 was melted and mixed with VESTOPLAST 206, the mixture then coated onto dry sand and polypropylene fibers by mixing at above ambient temperature, in the following proportions: 4% Hydrocarbon wax, 1.5% polyester fibers, 0.04% VESTOPLAST 206, 1.5% polyester staple fibers and the balance dry sand. The material was then allowed to cool before measurement. The material was a reasonably cohesive, reasonably soft material.

Present Invention Example 3: Preparation of material of the present invention - Sample 6

[0048] The hydrocarbon oil used in the preparation of Sample 3 was heated and mixed with VESTOPLAST 206 whereby the VESTOPLAST 206 dissolved in the oil and the mixture was coated onto dry sand and polyester fibers by mixing, in the following proportions: 2% hydrocarbon oil, 0.04% VESTOPLAST 206, 1.5% polyester fibers and the balance dry sand. The material was then allowed to cool before measurement. The material was a reasonably cohesive, reasonably soft material. Present Invention Example 4: Preparation of material of the present invention - Sample 7

[0049] A monomeric silane, specifically an octyltrimethoxysilane, manufactured and sold by Momentive as SILQUEST A- 137, was mixed with APAO and mineral oil and coated onto sand and fibers in the following proportions: 1.8% APAO, 1.8% mineral oil, 1.5% polypropylene staple fibers, 0.04% SILQUEST A- 137, the balance being sand. The material was then allowed to cool before measurement. The material was a reasonably cohesive, reasonably soft material.

Example of improvement in wear resistance of rejuvenated material - samples 8 & 9

[0050] A sample of worn out equestrian riding surface based on a sand/ AP AO/oil binder/fiber system from a riding arena in Virginia, U.S.A. (FIG. 15), that exhibits separation of sand from fibres, and poor cohesion and cushioning, was treated in the following way to rejuvenate it: to one sample was added 0.5% by weight mineral oil, and the material worked by stirring with a spatula for 2 minutes. The material transformed from a poorly mixed, low cohesion, dusty mixture, to a well mixed, cohesive continuous structure. (Sample 8). To a second sample was added 0.5% by weight mineral oil containing 0.04% by weight SILQUEST A- 137 silane coupling agent. The material was worked by stirring with a spatula for 2 minutes. The material transformed from a poorly mixed, low cohesion, dusty mixture, to a well mixed, cohesive continuous structure. (Sample 9).

Present Invention Example 5 : Alternative monomeric coupling compound

[0051] A sample was produced in the same manner as Sample 7, but using

DYNASYLAN 9116 supplied by Evonik. This compound is hexadecyltrimethoxysilane so has a long chain paraffinic functional group, likely to interact well with hydrophobic coatings. A level of 0.02% was used. This sample is designated Sample 10. Accelerated Measurement of Resistance to Wear

[0052] Samples of material from each of the examples (Samples 1-14) were placed respectively in a glass jar, along with an equal weight of distilled water, and four 15 mm diameter glass beads. The jars were sealed and placed on a bottle roller rotating at 1 revolution per minute for a total of 10,800 revolutions. The materials were then removed and dried in a circulating oven at 40°C. to remove the moisture. The samples were then visually inspected and photographed, with the following observations noted, and the separated sand weighed and calculated as a percentage of the total footing weight. In the case of

Samples 10-14, an alternative method was adopted in which the weight of intact footing was recorded as a measure of wear resistance, rather than the separated sand.

Footing Material % Weight of Observations After Accelerated Wear Testing Description separated sand Protocol

Prior art - Sample 1 50.4 Significant separation of sand from fibers. Sand has no cohesion.

Prior art - Sample 2 33.2 Significant separation of sand from fibers. Sand has slight cohesion.

Prior art - Sample 3 31.6 Significant separation of sand from fibers. Sand has no cohesion.

Sample 4 2.0 Very slight separation of sand from fibers. Sand has cohesion.

Sample 5 1.6 Very slight separation of sand from fibers. Sand has cohesion.

Sample 6 21.6 Slight separation of sand from fibers. Sand has cohesion.

Sample 7 14.4 Slight separation of sand from fibers. Sand has cohesion.

Sample 8 72.0 Significant separation of sand from fibers. Sand has no cohesion Sample 9 44.4 Some separation of sand from fibers. Sand has cohesion

TABLE 2

[0053] As noted above in the Description of the Drawings, photographs of the samples both before and/or after wet wear testing are shown below in FIGS. 1-24. As reflected in the post- wear test values obtained and the corresponding photographs, the use of an appropriate coupling compound improves the resistance of the footings to wet wear.

[0054] In a separate set of experiments the level of coupling agent required to bring about an improvement in wear resistance was investigated.

[0055] Three samples were produced in a similar way to Sample 7, but containing different levels of A-137 coupling agent, i.e., 0.02%, 0.01% and 0.002% by weight on total weight of sample, designated Samples 11, 12, 13 respectively. In addition, a similar sample was prepared but using a different coupling agent, XIAMETER OFS-6032 (in which the active agent is vinylbenzylaminoethylaminopropyltrimethoxysilane) produced by Dow Corning (available as a 40% solution in methanol), at a level of 0.01%. The 0.01% level refers to the proportion of the active compound, i.e., it does not include the methanol portion. The sample was given the designation Sample 14.

[0056] Samples 11-14 were subjected to the Accelerated Wear test described earlier, but the level of wear was quantified by measuring the weight of intact footing, rather than the weight of the separated sand. [0057] Figures 20-23 respectively show the 0.02%, 0.01% and 0.002% A-137 samples after the wear test, whist Figure 24 illustrates the 0.01% OFS-6032 sample also after the wear test.

[0058] The quantitative data is shown in the table below (Table 3).

TABLE 3

[0059] It appears that silane-modified coupling agents such as A-137 tend to be effective down to levels of about about 0.02%, whilst the OFS-6032 is still effective at a level of 0.01%. It is suspected that the improved performance of the OFS-6032 may be attributable to the presence of two effective functional groups that may interact with the coating layer, vinylbenzene and ethylenediaminopropyl, while also including a moiety better configured for binding to the sand or other particles, the trimethoxysilyl. This material seems particularly effective at improving the wear resistance of the APAO-based materials, and would be expected also to be effective with the wax-based materials. [0060] Those skilled in the art will also appreciate that the surfacing compositions disclosed herein may be further modified for particular applications by taking into consideration such factors as the anticipated temperature range, the depth of the surfacing composition and the moisture control available. While the invention has been particularly shown and described with reference to certain example embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the following claims.

Claims

1. A surfacing composition comprising:

from 80 to 98 wt% sand;

from 1 to 10 wt of an organic coating, the coating selected from a group consisting of coating polymers, coating waxes and mixtures, blends and combinations thereof;

from 0.1 to 5 wt of fibers having a staple length of 3.2 to 25.4 mm and an average fiber diameter of 0.5 to 12 Denier; and

at least 0.002 wt of a coupling agent.

2. The surfacing composition according to claim 1, wherein:

the coupling agent is selected from a group consisting of monomeric silanes, polymeric silanes, and mixtures and combinations thereof.

3. The surfacing composition according to claim 1, wherein:

the coupling agent is an alkylalkoxysilane.

4. The surfacing composition according to claim 1, wherein:

the coupling agent includes a functional group selected from a group consisting of trimethoxysilane, triethoxysilanes and mixtures thereof.

5. The surfacing composition according to claims 1-4, wherein:

a major portion of the sand comprises grains classified as angular or sub-angular; the fibers are selected from a group of synthetic fibers consisting of rayons, nylons, polyesters, acrylics, polypropylenes, polyethylenes and combinations and mixtures thereof; and

the organic coating includes at least one component selected from a group consisting of waxes, poly-a-olefins, ethylene vinyl acetates (EVA), polyamides, polybutylenes (PB), polystyrenes (PS), polyvinylchlorides (PVC), polyvinylidenechlorides, acrylonitrile butadiene styrenes (ABS), acrylics, polyisobutylenes, natural rubber, polyethylenes, polypropylenes, and mixtures and combinations thereof.

6. The surfacing composition according to claims 1-5, wherein: a coating polymer is present in the organic coating, the coating polymer being selected from a group consisting of polymers that exhibit both a softening point of 80 to 165° C, as measured according to ASTM D36-06 or DIN EN 1427, and

a melt viscosity at 190° C. of 2 to 120 Pa-s, as measured according to ASTM D3236- 88 or DIN 53 019.

7. The surfacing composition according to claims 1-6, further comprising:

from 0.1 to 10 wt of an oil characterized by a viscosity at 40° C. of 20 to

100 centistokes as measured according to ASTM D445 and wherein the oil is suitable for forming a dispersion with the coupling agent.

8. The surfacing composition according to claim 7, wherein:

the oil is selected from a group consisting of mineral oils, paraffinic oils, aromatic oils, naphthenic oils, and mixtures and combinations thereof.

9. A method of manufacturing the surfacing composition according to claim 1 comprising:

heating a charge of dry, cleaned sand to a temperature above a softening point temperature of the organic coating;

applying the organic coating and the coupling agent to the surfaces of the heated sand while maintaining the sand at a temperature above the softening point temperature of the organic coating to form a coated mixture; and

distributing the fibers throughout the coated mixture to form the surfacing composition.

10. A method of manufacturing the surfacing composition according to claim 1 comprising:

distributing the coupling agent throughout the heated sand to obtain pretreated sand; distributing the organic coating throughout pretreated sand while maintaining the pretreated sand at a temperature above the softening point temperature of the organic coating to form a coated mixture; and

11. A method of manufacturing the surfacing composition according to claim 1 comprising:

defining a charge of a degraded surfacing composition, the degraded surfacing composition comprising from 80 to 98 wt sand, from 1 to 10 wt of an organic coating and from 0.1 to 5 wt of fibers; and

distributing the coupling agent throughout the degraded surfacing composition to rejuvenate the degraded surfacing composition.

12. The method of manufacturing the surfacing composition according to claim 11, the step of distributing the coupling agent further comprising:

mixing the coupling agent with an oil to form a dispersion; and

distributing the dispersion throughout the degraded surfacing compound.

13. The method of manufacturing the surfacing composition according to claim 12, wherein:

the coupling agent and the oil are present in the dispersion in a ratio of from 1 : 1 to

1:50.

14. The method of manufacturing the surfacing composition according to claim 12, wherein:

1:10.

15. The method of manufacturing the surfacing composition according to claim 12, wherein:

1:5.

16. The method of manufacturing the surfacing composition according to claims 12-15, wherein:

17. The method of manufacturing the surfacing composition according to claim 11, the step of distributing the coupling agent further comprising: mixing the coupling agent with a low viscosity polymer to form a dispersion; and distributing the dispersion throughout the degraded surfacing compound.

18. The method of manufacturing the surfacing composition according to claim 17, wherein:

the low viscosity polymer is polyisobutylene (PIB).

19. The method of manufacturing the surfacing composition according to claims 11-18, further comprising:

heating the charge of the degraded surfacing composition to a temperature above a softening point temperature of the organic coating; and

distributing the coupling agent throughout the heated charge of the degraded surfacing composition to rejuvenate the degraded surfacing composition.