FIELD OF THE INVENTION

[0001] The subject matter of the present invention relates to a rubber mix having increased thermal conductivity, similar energy dissipation, and increased durability comprised of a reinforcing filler consisting of a high specific surface area and high structure acetylene carbon black.

BACKGROUND OF THE INVENTION

[0002] There is a need for a rubber composition having high thermal conductivity. A rubber composition having high thermal conductivity could be used to construct efficient curing bladders, more performant tires for heavy machines, specific rubber products in vehicle tires and non-tire performant rubber products.

[0003] Tires are cured in a ridged mold that forms the exterior of the tire. An uncured rubber “green” tire is placed into the mold and a flexible rubber curing bladder is pressurized with hot steam, pressing the green tire against the ridged mold. The heat triggers the vulcanization of the rubber, curing the tire in its finished shape. Improvements to the thermal conductivity of the curing bladder would increase the efficiency of the curing process and speed up cure time, reducing manufacturing cost and enabling new curing procedures by allowing increased heat transfer to the curing rubber product.

Because these bladders have a limited lifespan and eventually tear and rupture, they are considered a consumable in the tire manufacturing process. A bladder constructed of an cost-effective rubber mix having superior thermal conductivity and reasonable tear resistance would be particularly useful.

[0004] Rubber mixtures useful for tire construction with an increased thermal conductivity will enable tires to perform at increased load levels or/and at increased speeds. In industries such as mining, heavy equipment operates at the limits of the vehicle’s tire’s ability to dissipate heat that would otherwise damage the rubber tire. A tire constructed of a rubber having a higher thermal conductivity could be useful to allow for increased vehicle speed or load carrying capacity, reducing mining costs and increasing productivity. For example, a very large earth mover tire with tread rubber having increased thermal conductivity will reduce the operational temperature of the tread rubber and the under-tread layer. Of particular use would be a rubber mixture having increased wear resistance, aggression resistance, summit endurance, and thermal conductivity.

[0005] Rubber having an increased thermal conductivity would be of particular use in certain locations of a tire where heat is of a particular concern. For example, increasing the thermal conductivity of some specific rubber products in the tire will decrease the operational temperature of the corresponding location in the finished cured tire product such as the tread rubber, the under- tread rubber layer, the belt wedges, or the bead area. Of particular use would be a rubber mix having superior thermal conductivity with reasonable fatigue resistance or aggression resistance.

[0006] Other applications that can benefit from a rubber mixture having superior thermal conductivity and reasonable durability would include high performance rubber gaskets and seals.

[0007] Furnace carbon black is a material produced by the incomplete combustion of heavy petroleum products such as FCC tar or coal tar. Carbon black is mainly used as a reinforcing filler, UV inhibitor, and pigment in tires and other rubber products. Furnace carbon black has a limited ability to enhance the thermal conductivity of rubber. Carbon blacks are usually described and compared using an ASTM designation and corresponding names which are used to help group the carbon blacks by method of production and physical characteristics. For example, ASTM International’s D1765 “Carbon Black Used in Rubber Products” defines typical property values for 43 rubber grade carbon blacks. Within this standard’s target properties (Iodine Adsorption Number and Oil Absorption Number), typical properties (Oil Absorption Number of Compressed Sample, NSA Multipoint, STSA, Tint Strength, and Pour Density) have been defined and accepted in the global carbon black industry to ease communication of product requirements between carbon black suppliers and rubber compound manufacturers.

[0008] Acetylene carbon black is a type of carbon black made from the thermal decomposition of acetylene gas, resulting in a relatively high thermally conductive rubber when used in a rubber mix. It is known that utilizing acetylene carbon black in a rubber mixture can increase the thermal conductivity of the finished rubber product, but it has long been recognized that acetylene carbon black lacks the ability to increase the structural reinforcement of the rubber to sufficient levels without an additional reinforcing filler. It has been common practice to mix acetylene carbon black with other carbon blacks (like furnace carbon blacks) and reinforcing fillers, such as silica, to create a durable rubber product. The addition of these reinforcing fillers at iso-total volume of the fillers, or at iso rigidity of the pure acetylene carbon black mix, however, decreases the thermal conductivity properties of the finished product. Of particular use would be the identification of a rubber mixture using acetylene black having a sufficient reinforcing effect on the finished rubber product.

[0009] For example, US Patent Application No. 2005/0159353 A1 by L.R. Spadone and P.H. Sandstrom (“Spadone”) discloses the use of hybrid mixes containing two distinct types of carbon blacks: an acetylene carbon black with another reinforcing carbon black for the tread of tires such as off-road tires, airplane tires, and large truck tires. The mixtures contained a reinforcing filler in addition to the acetylene carbon black.

[0010] Another example of a tire with rubber tread highly loaded with a combination of filler reinforcement and oil is US 2007/0072984 A1 also by P.H. Sandstrom. In this rubber composition for racing tires, a composition with acetylene carbon black alone having a specific surface area of between 80 and 120 m ² /g is disclosed. This publication teaches away, however, from use of acetylene carbon blacks alone because “they present a less reinforcing capability for tire component rubber compositions.”

[0011] Other applications recommend not using high surface area acetylene carbon black. For example publication US 2004/0198890 by D. Kanenari describes a rubber composition containing acetylene carbon black having a surface area of less than 70 m ² /g, for a use in the sidewall or the bead of a run-flat tire.

[0012] Likewise in the publication EP 1582559 A1 by J. Kleffmann, K. Thielemann, T. Neddenriep, and A. Topp, a hybrid mix using ASTM reinforcing carbon black/acetylene carbon black in a tire tread for truck tires is disclosed. It is explained that a pure acetylene carbon black mix cannot be used, as the wear properties would be affected significantly.

But the authors found that when using it with a reinforcing ASTM carbon black, relatively high concentrations can be incorporated without any major decrease of the wear resistance. The claimed concentration is between 15 to 20 phr (with 25 to 35 phr of the reinforcing carbon black). The acetylene black that is reported in the examples has a specific surface area of 75 m ² /g.

[0013] What is needed is a rubber mix having a high thermal conductivity and reinforcing properties without having to resort to other reinforcing fillers than acetylene carbon black to enhance the structural properties of the finished rubber product. SUMMARY OF THE INVENTION

[0014] Aspects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.

[0015] In one exemplary embodiment, a rubber composition is provided based on at least one diene elastomer, a crosslinking system, and a filler consisting of acetylene carbon black having a surface area of approximately 155 m ² /g +/- 35 m ² /g.

[0016] These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS [0017] A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which:

[0018] FIG. 1 provides RPA curing profiles at 150°C. Rubber mixes made with N234 carbon black and the high specific surface area acetylene carbon black products at iso volume concentration, plus one mix at 35 phr of Li 435, which is at iso-rigidity vs. the mix with N234 carbon black.

[0019] FIG. 2 shows MSV curves of rubber mixes made with N234 carbon black and the high specific surface area acetylene carbon black products at iso-volume concentration, plus one mix at 35 phr of Li 435 acetylene carbon black which is at iso-rigidity vs. the mix with N234 carbon black.

[0020] FIG. 3 provides a DMA analysis of rubber mixes made with N234 carbon black and the high specific surface area acetylene carbon black products at iso- volume concentration, plus one mix at 35 phr of Li 435 acetylene carbon black which is at iso rigidity vs. the mix with N234 carbon black, showing G* (MPa) across a strain %.

[0021] FIG. 4 provides a DMA strain sweep of tangent delta versus strain percentage of rubber mixes made with N234 carbon black and the high specific surface area acetylene carbon black products at iso-volume concentration, plus one mix at 35 phr of Li 435 acetylene carbon black which is at iso-rigidity vs. the mix with N234 carbon black). Strain sweep at 23 °C. [0022] The use of identical or similar reference numerals in different figures denotes identical or similar features.

DETAILED DESCRIPTION OF THE INVENTION [0023] The present invention provides a thermally conductive durable rubber composition. For purposes of describing the invention, reference now will be made in detail to embodiments and/or methods of the invention, one or more examples of which are illustrated in or with the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features or steps illustrated or described as part of one embodiment, can be used with another embodiment or steps to yield a still further embodiment or method. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.

[0024] In the examples that follow, various material properties are described. These properties were obtained using tests as ordinarily used to quantify such properties and are described as follows:

[0025] A true secant modulus of elongation (MPa) was measured at 10% (MA10), 100% (MA100) and 300% (MA300) at temperature of 23°C based on ASTM Standard D412 on dumb bell test pieces. The measurements were taken in the second elongation; i.e., after an accommodation cycle.

[0026] The elongation property was measured as strain at break (%) and the corresponding stress at break (MPa), which is measured at 23 °C in accordance with ASTM Standard D412 on ASTM C test pieces.

[0027] The shear modulus G* at 10% strain and the maximum tan delta dynamic properties for the rubber compositions were measured at 23 °C on a Metravib Model VA400 ViscoAnalyzer Test System in accordance with ASTM D5992-96. The response of a sample of vulcanized material (double shear geometry with each of the two 10 mm diameter cylindrical samples being 2 mm thick) was recorded as it was being subjected to an alternating single sinusoidal shearing stress at a frequency of 10 Hz under a controlled temperature of 23° C. Scanning was effected at an amplitude of deformation of 0.05 to 50% (outward cycle) and then of 50% to 0.05% (return cycle). The shear modulus G* at 10% strain and the maximum value of the tangent of the loss angle tan delta were determined during the return cycle.

[0028] To test fatigue of the elastomer samples, testing in accordance with ASTM D4482 - 11(2017) Standard Test Method for Rubber Property was carried out. The extension cycling fatigue temperature was set at 25 °C. Testing was stopped at 500 kilocycles, so any non-broken sample at the end of the test was automatically assigned a value of 500 kilocycles. The true fatigue resistance of the material is then not assessed if it survives 500 kilocycles, but for our study, it was sufficient to show differences, as N234 at 50 phr broke at much lower values.

[0029] To test tear strength of the elastomer samples, testing in accordance with ASTM D624 - 00(2012) “Standard Test Method for Tear Strength of Conventional Vulcanized Rubber and Thermoplastic Elastomers” was conducted at 100°C.

[0030] Testing of thermal conductivity of the rubber mix was performed in accordance with the following equation:

The mix density was calculated based on its composition using the rule of mixtures applied to the densities of the individual components, the specific heat was measured by Differential Scanning Calorimetry (DSC) and the thermal diffusivity was measured with a LFA 447 NanoFlash system from Netzsch.

[0031] Particular embodiments of the present invention include tire treads, tire under tread layer, belt wedges, and bead filler rubber and tires having such components, and other useful articles manufactured at least in part with the rubber compositions disclosed herein.

It has been found that when tires are made from such rubber compositions, a reduction in the peak temperature, decreased wear, increased aggression resistance, increased summit endurance, and increased maximal operational speed of the tire can be achieved. The use of high specific surface area acetylene carbon black without additional reinforcing fillers, surprisingly provide enhanced physical characteristics of the finished rubber product.

Three grades of acetylene carbon black, available from Denka Co. (560 Highway 44 La Place, LA 70068, U.S.A.), were characterized: Li 400, PG06365, and Li 435. PG06365 is in pelletized form and the other two references are not. An ASTM classified reinforcing carbon black, N234, was used as the reference for the following examples.

[0032] Particular embodiments of such rubber compositions include high specific surface area acetylene carbon black with synthetic rubber specifically styrene-butadiene rubber as the majority rubber component without significant additional reinforcing filler. Alternatively, other embodiments may utilize natural rubber, synthetic polyisoprene, and/or essentially saturated elastomers such as butyl rubber. Because of the improved wear, rolling resistance, and processability of these disclosed rubber compositions, they are particularly useful for manufacturing treads for heavy earthmover tires as well as for passenger and truck tires. The combination of tear resistance and increased heat conductivity makes them particularly useful for tire bladder construction.

[0033] As is well known in the art, a tire tread may be mounted on a tire during a rebeading process, wherein the old tread on a tire is ground off and a new tread band is bonded to the tire to provide new tread life for a used tire carcass. Such tread bands may be cured before they are bonded to a tire or may be cured after they are mounted on the tire. [0034] It is well known that treads may be formed as tread bands and then later made a part of a tire or they may be formed directly onto a tire carcass by, for example, extrusion and then cured in a mold.

[0035] As used herein, "phr" is “parts per hundred parts of rubber by weight” and is a common measurement in the art wherein components of a rubber composition are measured relative to the total weight of rubber in the composition, i.e., parts by weight of the component per 100 parts by weight of the total rubber(s) in the composition.

[0036] As used herein, elastomer and rubber are synonymous terms.

[0037] As used herein, “based upon” is a term recognizing that embodiments of the present invention are made of vulcanized or cured rubber compositions that were, at the time of their assembly, uncured. The cured rubber composition is therefore “based upon” the uncured rubber composition. In other words, the cross-linked rubber composition is based upon or comprises the constituents of the cross-linkable rubber composition.

[0038] Reference will now be made in detail to embodiments of the invention. Each example is provided by way of explanation of the invention. For example, features illustrated or described as part of one embodiment can be used with another embodiment to yield still a third embodiment. It is intended that the present invention include these and other modifications and variations. [0039] As is known generally, a tire tread is the road-contacting portion of a vehicle tire that extends circumferentially around the tire. It is designed to provide the handling characteristics required by the vehicle; e.g., traction, dry braking, wet braking, cornering and so forth - all being preferably provided with a minimum amount of noise being generated and at a low rolling resistance.

[0040] The undertread rubber is a layer of rubber that has a different composition than the tread rubber, placed between the tread and the tire’s reinforcements. The undertread may be a layer used in retreading to provide adhesion of the tread rubber to the carcass, or may be formed as a part of the new tire from a rubber composition that has properties different than the tread rubber to increase the performance of the tire, such as high-speed durability or fuel economy.

[0041] The bead filler, alternatively called the “bead apex”, is layer of rubber above the bead of the tire. Generally, the bead filler has a triangular cross section and is positioned to the outside of the carcass ply, or between the carcass ply and a portion of the carcass ply that wraps around the bead. The bead filler provides additional stiffness and support to the lower sidewall.

[0042] It is known that the mechanical properties of a rubber mix will depend on the filler specific surface area, its structure, and its surface chemistry. Particular embodiments of such rubber compositions include high specific surface area and high structure acetylene carbon black as a heat conductive reinforcing filler.

[0043] The specific surface areas of the acetylene blacks are reported in Table 1. It is clear that a wide range of specific surface areas is covered, from low surface area (around 40 m ² /g) to high surface area (around 160 m ² /g). The specific surface area was determined by ASTM Standard D6556 for determining the total and external surface area by nitrogen adsorption.

Table 1. Specific surface areas of the acetylene carbon blacks and N234 carbon black.

[0044] Mercury porosimetry gives 1 mL.g ^-1 of inter- aggregates porosity for Li 435 versus 0.4-0.7 mL.g ¹ for an ASTM 300 series carbon black. [0045] The elemental composition of the three references of acetylene carbon black was relatively similar, as measured by Energy Dispersive X-ray Spectroscopy (EDS) with a Scanning Electron microscope (SEM), in accordance with ASTM E1508-12a. The JEOLJSM-7100F Field Emission Scanning Electron Microscope equipped with a JED- 2300 Energy Dispersive X-Ray Analyzer was used. All the references were made of carbon and oxygen only, with a high carbon content superior to 99.0% (Table 2). One thing that can be noticed is that N234 contains some sulphur, which is not the case for the acetylene carbon blacks.

Table 1: Elemental composition of the acetylene carbon blacks and of N234 carbon black.

[0046] Mixes were made in solution SBR at iso- volume concentration in carbon black (Table 3). In this particular embodiment, the SBR elastomer was 27% styrene with an Mn of 118,700 g/mol and the butadiene portion having 24% vinyl, 46% trans and 30% cis bonds. The concentration of the filler was 50 phr. Conventional mixing (Bandbury mixer) and milling processes were used.

Table 2: Composition of the rubber mixes made with each acetylene carbon black and the N234 carbon black reference.

[0047] The rubber formulations were prepared by mixing the components given in Table 3, except for the sulphur and the accelerator, in a Banbury mixer operating between 30 and 90 RPM until a temperature between 130 degrees Celsius and 165 degrees Celsius was reached. The accelerator and sulfur were added in the second phase on a mill.

[0048] Rubber Process Analysis (RPA) curves obtained at 150°C show that the curing profiles of the rubber mixes made with the acetylene carbon black products are similar to the profile obtained with N234 carbon black, except for a longer scorch as shown in FIG. 1 and Table 4. The curing law of the rubber mixes made with acetylene carbon black products is therefore shown to be compatible with industrial practices.

Table 3: Scorch times corresponding to rubber mixes made with N234 carbon black and the acetylene carbon black products at iso-volume.

[0049] The static tensile properties of the rubber mixes at iso- volume concentration show that the three acetylene carbon black mixes have varying degrees of reinforcing properties, even with Li 400 which is the low specific surface area reference, as can be observed in FIG. 2. This is unexpected from acetylene carbon black and other graphitic- type carbon blacks, as it is believed that a graphitization of carbon black leads to poor interfacial adhesion and low reinforcement. The slope of the MSV curve decreases at high strain for Li 400 and PG06365, which highlights a lack of interfacial adhesion, still.

[0050] Most surprisingly, the Li 435 reference is more reinforcing than N234 when comparing the tensile stress at break and the value of MA300/MA100. Such a characteristic is both surprising, unique and until now, undisclosed for an acetylene carbon black. The high specific surface area and high structure are shown here to be correlated with this effect. The inventor believes that the high specific surface area and/or the interparticle porosity are responsible for this reinforcing characteristic of the high specific surface area acetylene carbon black. [0051] Except for Li 400, the acetylene carbon blacks show higher rigidifying effect than N234. Also, the upturn of the MSV curve occurs at lower strain, which suggests that the overall structure of the acetylene carbon blacks is also higher.

[0052] When comparing mixes at iso-rigidity, that is a mix having 35 phr of Li 435 acetylene carbon black and a mix having 50 phr of N234 carbon black, the mix with Li 435 acetylene carbon black is less reinforced than with N234 carbon black.

Table 4: Tensile properties indicators corresponding to Figure 2.

[0053] The dynamic properties confirmed a higher rigidity for acetylene carbon black PG06365 and acetylene carbon black Li 435 versus carbon black N234 at iso-volume as shown in FIG. 3, LIG. 4 and Table 6. The strain sweep shown in LIG. 4 is taken at 23 degrees Celsius.

[0054] A better rigidity versus energy dissipation compromise is obtained for PG06365 and Li 435 vs. N234, which should lead to less self -heating of the corresponding rubber products in a rolling tire. Indeed, mixes with 50 phr of N234 and 50 phr of PG06365 have a similar tan delta, but the rigidity is much higher with the Denka product. Mixes with 50 phr of N234 and 35 phr of Li 435 have identical rigidities, but max tan delta is slightly lower with the acetylene carbon black.

Table 6: Dynamic properties indicators corresponding to Figure 4.

[0055] At iso-rigidity, a mix with Li 435 revealed to have much better fatigue properties than with N234 (Table 7). This is very interesting for the design of rubber products that are located where heat is typically generated (end of the belts in the shoulder area of the tire, end of NC in the bead area). Fatigue is typically the main reason for the generation of cracks in the rubber part of the belts. That could also be interesting for rubber products located in the shoulder that separates the belts like belt wedges.

Table 7: Fatigue properties of the reference mix with N234 and the equivalent mix at iso-rigidity with Li 435.

[0056] One drawback associated to the use of these acetylene carbon blacks was a deterioration of the tear resistance (Table 8). At iso-volume concentration, the higher specific surface area acetylene carbon blacks (PG06365 and Li 435) still give a decent value vs. N234. But at lower concentration, the deterioration is significant (example of a mix with 35 phr of Li 435).

Table 5: Tear resistance values for the rubber mixes made with N234 and the Denka products at iso-volume concentration (plus one mix at 35 phr of Li 435 which is at isorigidity vs. the mix with N234). [0057] At iso- volume concentration, the thermal conductivity of the mixes with the Denka acetylene carbon blacks was much higher than with N234 (+40% with Li 435, +28% with Li 400 - Table 9). One surprising observation is that Li 435 leads to a higher thermal conductivity than Li 400 (it is usually considered that larger graphitic particles with lower specific surface area give higher thermal conductivity).

Table 9: Thermal conductivities of rubber mixes made with N234 and the Denka products at iso-volume concentration (plus one mix at 34 phr of Li 435 which is at isorigidity vs. the mix with N234).

[0058] More reinforcing fillers are usually more energy dissipative. When comparing rubber mixes at iso-rigidity with N234 and Li 435, the thermal conductivity is much higher AND the energy dissipation is slightly lower in the case of Li 435. This should enable a large decrease of operational temperatures for rubber mixes containing Li 435 in comparison to mixes made with N234.

[0059] Mixes using high specific surface area acetelyne carbon blacks, that is, using acetylene carbon black having a specific surface area greater than 120 m ² /g could increase the lifetime and the efficiency of curing bladders, as the mix would have enhanced thermal conductivity properties. High surface area acetylene carbon black, as defined herein refers to acetylene black having a specific surface area of approximately 155 m ² /g and more specifically in a range between 120 m ² /g and 190 m ² /g. Even more specifically a range between 150 m ² /g and 160 m ² /g.

[0060] A rubber mixture comprising high specific surface area acetylene carbon black could accelerate the diffusion of heat in the green tire during curing. For large tires like large earthmover tires weighing hundreds of pounds, that could result in decreased curing times and gain in productivity, or enable a change of the curing package for the different rubber products, therefore potentially enabling significant changes in thermo-mechanical properties and resistance to ageing.

[0061] For tread and undertread formulation, the use of high specific surface area acetylene carbon black would reduce the need to use mixes containing another reinforcing filler that compensates for the deterioration of the mechanical properties when otherwise using low specific surface area acetylene carbon black. Rubber mixes containing high specific surface area acetylene carbon black such as Li 435 as the sole reinforcing filler can be considered, which should lead to new tread rubber formulations with much higher thermal conductivity. The high speed limits set by concern for tire self-heating is a performance that could be improved as well.

[0062] Because the fatigue properties were also very good, it seems logical that high specific surface area acetylene carbon black such as Li 435 could be used in rubber products that are subjected to heat generation and which performance are defined by their resistance to fatigue. This is typically the case for rubber mixes used in belts and carcass plies, rubber mixes used in belt insulation, rubber products used in the bead area, and rubber products used in the sidewall.

[0063] The good mechanical properties/thermal conductivity compromise obtained with high specific surface area acetylene carbon black such as Li 435 is also very interesting for non- tire and high value rubber applications like rubber gaskets.

[0064] Selected combinations of aspects of the disclosed technology correspond to a plurality of different embodiments of the present invention. It should be noted that each of the exemplary embodiments presented and discussed herein should not insinuate limitations of the present subject matter. Features or steps illustrated or described as part of one embodiment may be used in combination with aspects of another embodiment to yield yet further embodiments. Additionally, certain features may be interchanged with similar devices or features not expressly mentioned which perform the same or similar function. [0065] The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “40 mm” is intended to mean “about 40 mm.” Also, the dimensions and values disclosed herein are not limited to a specified unit of measurement. For example, dimensions expressed in English units are understood to include equivalent dimensions in metric and other units (e.g., a dimension disclosed as “1 inch” is intended to mean an equivalent dimension of “2.5 cm”).

[0066] As used herein, the term “method” or “process” refers to one or more steps that may be performed in other ordering than shown without departing from the scope of the presently disclosed invention. As used herein, the term "method" or "process" may include one or more steps performed at least by one electronic or computer-based apparatus. Any sequence of steps is exemplary and is not intended to limit methods described herein to any particular sequence, nor is it intended to preclude adding steps, omitting steps, repeating steps, or performing steps simultaneously. As used herein, the term "method" or "process" may include one or more steps performed at least by one electronic or computer-based apparatus having a processor for executing instructions that carry out the steps.

[0067] The terms "a," "an," and the singular forms of words shall be taken to include the plural form of the same words, such that the terms mean that one or more of something is provided. The terms "at least one" and "one or more" are used interchangeably. Ranges that are described as being "between a and b" are inclusive of the values for "a" and "b." [0068] The citation of any document is not an admission that it is prior art with respect to any invention disclosed or claimed herein or that it alone, or in any combination with any other reference or references, teaches, suggests or discloses any such invention.

Further, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern.