Silicone rubber compositions

Abstract

This disclosure relates to curable high temperature vulcanizable or HTV silicone rubber compositions (i.e., usually cured / vulcanised at temperatures between about 100oC to 200oC) comprising physically recycled and / or reclaimed condensation cured elastomeric silicone particulates, silicone rubber elastomeric materials cured from said HTV curable silicone rubber compositions comprising physically recycled and / or reclaimed condensation cured elastomeric silicone particulates and a method for preparing said HTV curable silicone rubber compositions comprising physically recycled and / or reclaimed condensation cured elastomeric silicone particulates.

Description

[0001]SILICONE RUBBER COMPOSITIONS This disclosure relates to curable high temperature vulcanizable or HTV silicone rubber compositions (i.e., usually cured / vulcanised at temperatures between about 100oC to 200oC) comprising physically recycled and / or reclaimed condensation cured elastomeric silicone particulates, silicone rubber elastomeric materials cured from said HTV curable silicone rubber compositions comprising physically recycled and / or reclaimed condensation cured elastomeric silicone particulates and a method for preparing said HTV curable silicone rubber compositions comprising physically recycled and / or reclaimed condensation cured elastomeric silicone particulates. Silicone rubber compositions which are formed by HTV curable reactions are typically prepared by initially making a silicone rubber base composition by mixing polydiorganosiloxane polymers containing at least two alkenyl (or alkynyl) groups per molecule with reinforcing silica fillers but may include reinforcing and non-reinforcing inorganic or resinous siloxane fillers, and in some elastomeric applications may be unfilled, such as gels or coatings for protection of electronics. HTV curable silicone elastomers are distinguished from condensation curable or moisture curable (also known as room temperature vulcanizing (RTV)) silicone elastomers in that the curing reaction that forms the crosslinked network does not generate a leaving group, such as an alcohol, ketoxime or carboxylic acid. Examples of HTV curable silicone elastomers include those curable by hydrosilylation or by free radical initiation using e.g., peroxides. Despite the name, HTV materials can be cured at ambient or even sub-ambient conditions by an appropriate selection of catalysts, stabilizers and accelerants. Reinforcing silica fillers, when used are provided to enhance the physical properties of cured silicone materials. They are naturally hydrophilic which renders them difficult to inter-mix with the polydiorganosiloxane polymer(s) and as such said fillers are usually either pre-treated with a treating agent to render them hydrophobic, or alternatively are provided in a hydrophilic form. In the latter case a hydrophobic treating agent is usually (but not always) provided to treat the silica in situ during the base mixing process. i.e., incorporation and dispersion of silica in polymer is done in presence of a treating agent. The product of this mixing step is a silicone rubber base composition. This may be provided in a form suitable for mixing with other ingredients as discussed below. Alternatively, it may be in the form of a concentrate (often referred to by the industry as a “masterbatch” (MB)) which is typically diluted with further polydiorganosiloxane polymer(s) before use. A variety of treating agents may be utilised to render the filler hydrophobic. The treating agents reacts with OH-groups on the silica filler surface resulting in a reduced number of free OH-groups on the silica and as such rendering the silica surface increasingly hydrophobic. Once the silicone rubber base composition has been prepared, organohydrogen polysiloxanes and hydrosilylation catalyst(s) may be added to the base, in order to provide a hydrosilylation curable composition or in the case of free radical initiator curable formulations, they can be used to promote more effective curing. However, commercial hydrosilylation cure compositions, are usually produced in multiple parts, typically in two-parts, to prevent premature cure in storage prior to use. In such two-part compositions, one part, often referred to as Part A, comprises the pre-prepared base and a hydrosilylation catalyst and the second part, often referred to as Part B, comprises pre- prepared base and one or more organohydrogen polysiloxane cross-linker(s). Optionally one or more cure inhibitors may be added to the Part A composition, the Part B composition or both the Part A and the Part B compositions. Preferably both parts (A and B) are pumpable liquids, typically prepared using the pre-prepared base having a standard formulation with up to e.g., 30% silica and the remainder largely being liquid polydiorganosiloxanes containing at least two alkenyl groups per molecule. Probably the most commonly used alternative route to making silicone elastomeric materials other than via HTV cure processes as described above is using room temperature vulcanization (RTV) condensation curable compositions. However, the preparation of HTV and RTV elastomers involves very different cure chemistries and as such whilst potentially attractive, these different cure chemistries create issues for preparing hybrid HTV and RTV elastomers, as, for example, the condensation catalysts and additives used for RTV cure can poison platinum (Pt) catalysts in the hydrosilylation cure process and potentially create major safety hazards associated with hydrogen gas (H2) generation. Likewise, the condensation catalysts, crosslinkers and adhesion promoters present in RTV chemistry can cause various undesirable side effects such as inhibition, retardation or acceleration and instability of free radical initiator HTV cure systems. Therefore, mixing uncured HTV and RTV ingredients in a single composition is challenging and potentially dangerous. Given they are thermoset materials, silicone elastomers cannot be melted and reprocessed into polymers which are suitable to be used in their intended applications and as such it is difficult to provide an effective recycling and / or reclaiming alternative to incineration or landfilling as an end- of-life option to meet the desired “carbon footprint” reduction targets increasingly found in the manufacturing industry today. There are two main method types for recycling / reclaiming elastomeric materials these tend to be via “chemical processes” such as pyrolysis, chemical degradation and chemical reversion and by “physical processes”, i.e., mechanical processes such as mechanical reclaiming, thermo-mechanical reclaiming and cryo-mechanical reclaiming and wet / solution grinding methods. Given silicone elastomers are thermoset materials chemical recycling of silicone elastomers is not ideal because reclaiming / recycling requires significant separation and often generate solid residues that are typically of low value. That said, physically recycled and / or reclaimed silicone elastomeric particulates are typically incorporated as fillers in conjunction with a binder material that serves as an encapsulating matrix. The binder can be either a new silicone composition or an organic polymer material that can also be combined with an inorganic mixture such as an asphaltic or cementitious mixture and serves the function of entrapping and / or encapsulating the discrete particulates. However, physically recycled and / or reclaimed silicone elastomeric particulates have not been considered useful in higher value applications because of their inconsistency and variability in performance and therefore the value proposition for such recycled and / or reclaimed silicone elastomeric particulates is poor with the particulates only being deployed in lower value applications, lowering economic and technological incentives for reuse, as a result of: (i) poor incorporation of the silicone elastomeric particulates within the binder matrix; (ii) Interfacial adhesion and binding between the silicone elastomeric particulates and matrix being typically poor such that the preformed silicone elastomeric particulates can serve as defects in the matrix, creating voids, surface protrusions or other heterogeneities in the matrix, resulting in inferior properties to new silicone elastomers. A more sustainable hydrosilylation curable silicone rubber composition is provided for use in the manufacture of the silicone rubber elastomers described herein which provides a lower carbon footprint by enabling replacement of a significant amount of new liquid silicone masterbatch greater than ((>) 10 weight % (wt. %)) with physically recycled and / or reclaimed condensation cured elastomeric silicone particulates. It was surprisingly found that the varying sources of physically recycled and / or reclaimed silicone rubber particulates were unexpectedly compatible with the hydrosilylation curable compositions used. There is provided herein a curable high temperature vulcanizable (HTV) silicone rubber composition comprising: a) an organopolysiloxane polymer having a zero-shear viscosity of between 100 and 200,000mPa.s inclusive at 25 ºC having at least two unsaturated groups per molecule, which unsaturated groups are selected from alkenyl and / or alkynyl groups, or an organopolysiloxane polymer gum having a Williams plasticity of from 75mm / 100 to 500mm / 100 measured in accordance with ASTM D926-08, having at least two unsaturated groups per molecule, which unsaturated groups are selected from alkenyl and / or alkynyl groups; b) optionally reinforcing fillers comprising fumed silica, precipitated silica or a mixture thereof; either (c) or (d) wherein (c) Is a free radical initiator; or (d) Is a hydrosilylation catalyst package comprising (i) an organosilicon compound having an average of at least two or alternatively an average of at least three Si-H groups per molecule; and (ii) a hydrosilylation catalyst; and (e) physically recycled and / or reclaimed condensation cured silicone elastomer particulates (e)(i) having an average unswollen particle size of 1 mm or less, which physically recycled and / or reclaimed condensation cured silicone elastomer particulates (e)(i) have been penetrated and swollen by an organopolysiloxane polymer swelling agent (e)(ii) having a zero-shear viscosity of less than or equal to (≤) 15,000 mPa.s at 25oC. There is also provided a method of preparing a curable high temperature vulcanizable (HTV) composition comprising the steps of (1) mixing physically recycled and / or reclaimed condensation cured silicone elastomer particulates (e)(i) having an average unswollen particle size of 1 mm or less, with an organopolysiloxane polymer swelling agent (e)(ii) having a zero-shear viscosity of less than or equal to (≤) 15,000 mPa.s at 25oC to enable said organopolysiloxane polymer swelling agent (e)(ii) to penetrate and swell said physically recycled and / or reclaimed condensation cured silicone elastomer particulates (e)(i) to form component (e); (2) forming a step (2) mixture comprising at least part of component (a) with component (e) and optionally one or more of components (b) and (c) or (d); wherein a) an organopolysiloxane polymer having a zero-shear viscosity of between 100 and 200,000mPa.s inclusive at 25 ºC having at least two unsaturated groups per molecule, which unsaturated groups are selected from alkenyl and / or alkynyl groups, or an organopolysiloxane polymer gum having a Williams plasticity of from 75mm / 100 to 500mm / 100 measured in accordance with ASTM D926- 08, having at least two unsaturated groups per molecule, which unsaturated groups are selected from alkenyl and / or alkynyl groups; b) optionally reinforcing fillers comprising fumed silica, precipitated silica or a mixture thereof; either (c) or (d) wherein (c) Is a free radical initiator; and (d) Is a hydrosilylation catalyst package comprising (i) an organosilicon compound having an average of at least two or alternatively an average of at least three Si-H groups per molecule; and (ii) a hydrosilylation catalyst; (3) mixing the step (2) mixture with the remainder of components (b) and (c) or (d); to produce a hydrosilylation curable silicone rubber composition. In one embodiment step (1), step (2) and optionally step (3) may be undertaken together as a single step. There is also provided herein a cured product of a high temperature vulcanizable (HTV) composition obtained in accordance with the above method. There is also provided a use of physically recycled and / or reclaimed condensation cured silicone elastomer particulates (e)(i) having an average unswollen particle size of 1 mm or less, which physically recycled and / or reclaimed condensation cured silicone elastomer particulates (e)(i) have been penetrated and swollen by an organopolysiloxane polymer swelling agent (e)(ii) having a zero- shear viscosity of less than or equal to (≤) 15,000 mPa.s at 25oC; in a high temperature vulcanizable (HTV) composition otherwise comprising: a) an organopolysiloxane polymer having a zero-shear viscosity of between 100 and 200,000mPa.s inclusive at 25 ºC having at least two unsaturated groups per molecule, which unsaturated groups are selected from alkenyl and / or alkynyl groups, or an organopolysiloxane polymer gum having a Williams plasticity of from 75mm / 100 to 500mm / 100 measured in accordance with ASTM D926- 08, having at least two unsaturated groups per molecule, which unsaturated groups are selected from alkenyl and / or alkynyl groups; b) optionally reinforcing fillers comprising fumed silica, precipitated silica or a mixture thereof; either (c) or (d) wherein (c) Is a free radical initiator; or (d) Is a hydrosilylation catalyst package comprising (i) an organosilicon compound having an average of at least two or alternatively an average of at least three Si-H groups per molecule; and (ii) a hydrosilylation catalyst; in the preparation of a curable high temperature vulcanizable (HTV) composition. High temperature vulcanizable or HTV silicone rubber compositions are compositions which ae curable at high temperatures typically between 100 and 200oC. It is to be noted however that whilst most hydrosilylation cure processes take place in that range some hydrosilylation cure processes may be achieved at lower temperatures with selected ingredients. The terms recycling and reclaiming as used herein are intended to define the function of recovering and converting waste materials into new materials and usable products. For the avoidance of doubt, the term average unswollen particle size is intended to mean the average particle size of the physically recycled and / or reclaimed condensation cured silicone elastomer particulates (e)(i) used herein subsequent to physical recycling the source of the physically recycled and / or reclaimed condensation cured silicone elastomer particulates (e)(i) and prior to mixing with a “swelling agent” otherwise identified as component (e)(ii) and / or organopolysiloxane polymer (e)(ii). This provides a more sustainable curable high temperature vulcanizable (HTV) composition offering a lower carbon footprint to the user by enabling replacement of a significant amount of new liquid silicone rubber (LSR) compositions or high consistency rubber (HCR), e.g., 10wt. % or more of the composition, with physically recycled and / or reclaimed condensation cured silicone elastomer particulates (e)(i), from a variety of sources, sufficiently compatible with said curable high temperature vulcanizable (HTV) composition s. Hence, this solution provides both the benefit, of reducing the carbon footprint associated with producing new curable high temperature vulcanizable (HTV) compositions, as well as providing a high value alternative to incineration or landfilling as an end-of-life option for the silicone elastomers used in the preparation of the physically recycled and / or reclaimed condensation cured silicone elastomer particulates (e)(i). The ability to penetrate and swell the physically recycled and / or reclaimed condensation cured silicone elastomer particulates (e)(i) with an organopolysiloxane polymer swelling agent (e)(ii) as described above results in the formation of interpenetrating networks between the new silicone composition and the physically recycled and / or reclaimed condensation cured silicone elastomer particulates (e)(i), resulting in of the presence of physically recycled and / or reclaimed condensation cured silicone elastomer particulates (e)(i) in a high temperature (i.e., 100oC to 200oC) cured elastomeric material without substantial degradation in mechanical properties (and potentially even “upcycling” through improved properties) of the resulting elastomeric material once cured. This has a direct benefit on the Life Cycle Assessment (LCA) of the curable high temperature vulcanizable (HTV) composition s by replacing carbon dioxide equivalence which goes into the making of the ingredients which go into curable high temperature vulcanizable (HTV) compositions with a recycled material that does not require capital- and energy-intensive molecular level purification steps like distillation. Physically recycled and / or reclaimed condensation cured silicone elastomer particulates (e)(i) The physically recycled and / or reclaimed condensation cured silicone elastomer particulates (e)(i) may be derived from any suitable source such as post-industrial scrap or waste rubber, pre-consumer scrap or waste rubber, or post-consumer scrap or waste rubber obtained from for example condensation cured (RTV) silicone elastomers formerly used as adhesives, refrigerant spacers, potting agents, coatings and sealants such as weatherproofing sealants and coatings and / or tire sealants. Physical recycling methods are utilised to transform silicone elastomers into powders, granules, crumbs, or pellets (referred to collectively herein as “particulates”). For the avoidance of doubt and for the sake of this disclosure physically (mechanically) recycled / reclaimed particulates have their original crosslinked structure preserved, whereas chemically recycled materials would not. When the origin of the cured silicone rubber elastomeric particulates is unknown a priori, the cured material from which it originates or the physically recycled or reclaimed particulates can be characterized by a variety of known methods to ascertain the composition including spectroscopic techniques including infrared techniques such as Fourier transform infrared (FTIR) spectroscopy, attenuated total reflectance infrared spectroscopy (ATR-IR), infrared microscopy, Raman spectroscopy, Raman microscopy, solid state nuclear magnetic resonance (NMR) spectroscopy; chemical derivatization and titration techniques; chemical digestion followed by chromatography such as gas chromatography (GC), gas chromatography-mass spectrometry (GC-MS), liquid chromatography (LC), or by a variety of known elemental or ion analysis techniques such as inductively coupled plasma-optical emission spectroscopy (ICP-OES), x-ray fluorescence (XRF), and neutron activation analysis (NAA). The physically recycled and / or reclaimed condensation cured silicone elastomer particulates (e)(i) are prepared by any suitable physical recycling method e.g., by grinding, milling, or pulverizing methods for example by mechanical reclaiming, thermo-mechanical reclaiming, cryo-mechanical reclaiming, and wet / solution grinding. Specific examples of methods which may be utilised to generate the particulates include, for the sake of example, cryomilling (at liquid nitrogen temperatures), using milling equipment known in the art such as ball mills, pin mills, and the like, tornado milling (which can be done at either ambient or cryogenic temperatures in the solid state) and wet jet milling (e.g., wet jet) where the rubber is pulverized by an intense water stream. The physically recycled and / or reclaimed condensation cured silicone elastomer particulates (e)(i) have an average particle size of 1 mm or less. Smaller particle sizes are preferable to minimize stress-concentrating defects in the new article, but satisfactory performance has been achieved even for relatively large 1 mm sized milled physically recycled and / or reclaimed condensation cured silicone elastomer particulates (e)(i). In one embodiment the average particle size of the physically recycled and / or reclaimed condensation cured silicone elastomer particulates (e)(i) was 600µm or less, alternatively the average particle size of the preformed silicone elastomeric particulates was 500µm or less, alternatively the average particle size of the preformed silicone elastomeric particulates was 400µm or less, alternatively the average particle size of the preformed silicone elastomeric particulates was 300µm or less, alternatively the average particle size of the preformed silicone elastomeric particulates was 200µm or less. Particulates of an acceptable size may be obtained by mechanical screening through a sized mesh. Smaller particles are obtained by filtering through increasingly small meshes. If desired for more accurate particle size measurements samples can be measured using laser diffraction with e.g., a Beckman CoulterTMLS 13320 Particle Size Analyzer with the Tornado (dry) module commercially available from Beckman Coulter Inc. relying on the Beckman CoulterTMsoftware to deconvolute the diffraction signal to a particle size distribution determined using Fraunhofer diffraction model. If the silicone elastomer to be made into particulates is adhered to another material in prior use, they are preferably separated or delaminated. After which the resulting silicone elastomer may be broken down into particulates using one of the processes listed above. However, it is to be understood that delamination or separation of silicone materials from certain substrates or articles may be imperfect and can lead to some residual minority fraction of adventitious non-silicone contaminants in the resulting particulates, such as small fragments of fabric or plastic substrates that may be present in quantities less than 10 wt. % of a particulate mixture, preferably 5 wt. % or less, with less being desirable. Physical recycling and / or reclamation using one or more of the different methods described above offers: 1) the advantage of being able to reuse inorganic fillers, 2) the ability to incorporate contaminated feedstocks from deployed silicone elastomers, and the ability to tolerate residual groups such as Si-H from hydrosilylation cured silicone elastomers without needing to undergo the depolymerization, neutralization, filtration, and stripping steps associated with chemical recycling processes. Penetration and Swelling of the physically recycled and / or reclaimed condensation cured silicone elastomer particulates (e)(i) with an organopolysiloxane polymer swelling agent (e)(ii) having a zero-shear viscosity of less than or equal to (≤) 15,000 mPa.s at 25oC. As discussed above the physically recycled and / or reclaimed condensation cured silicone elastomer particulates (e)(i) in the curable high temperature vulcanizable (HTV) composition which is cured herein have an average unswollen particle size of 1 mm or less. However, the physically recycled and / or reclaimed condensation cured silicone elastomer particulates (e)(i) are not just mixed directly into a standard curable high temperature vulcanizable (HTV) composition. to be encapsulated therein as the composition cures. They are initially immersed and / or soaked in a low viscosity organopolysiloxane polymer having a zero-shear viscosity of less than or equal (≤) to 15,000 mPa.s at 25oC (e)(ii), alternatively a zero-shear viscosity of from 100 to 13,000 mPa.s at 25oC (e)(ii), alternatively a zero-shear viscosity of from 100 to 10,000 mPa.s at 25oC (e)(ii), alternatively a zero- shear viscosity of from 100 to 7,500 mPa.s at 25oC (e)(ii), alternatively a zero-shear viscosity of from 100 to 5,000 mPa.s at 25oC (e)(ii), alternatively a zero-shear viscosity of from 100 to 2,000 mPa.s at 25oC (e)(ii). Examples of (e)(ii) include vinyl dimethyl terminated Divinyl-functional polydimethylsiloxanes, hydroxyl terminated polydiorganosiloxanes, alkoxy terminated polydiorganosiloxanes or siloxane cross-linkers as defined as component (d)(i) herein such as a polymethylhydrogen dimethylsiloxane copolymers. They may also be unreactive silicone plasticizers such as trimethyl terminated polydimethylsiloxanes. The organopolysiloxane polymer swelling agent (e)(ii) is present in the composition in an amount of from about 1.0 to 5.0wt. % of the composition. The physically recycled and / or reclaimed condensation cured silicone elastomer particulates (e)(i) may or may not be reactive with the organopolysiloxane polymer having a zero-shear viscosity of ≤ 15,000 mPa.s at 25oC (e)(ii), equally it may or may not be reactive with components of the composition in which it is to be situated. It was found that the inclusion of a pre-cured phase of physically recycled and / or reclaimed condensation cured silicone elastomer particulates (e)(i) within a second curable network with an organopolysiloxane polymer having a zero-shear viscosity of ≤ 15,000 mPa.s at 25oC (e)(ii) capable of penetrating and swelling particulates (e)(i) provides a means of forming double networks or inter-penetrating networks (IPNs). Without being bound to currently held theories it is believed that particulates component (e)(i) consists of a pre-cured cross-linked “mesh” component and composition of which component (e)(ii) forms a part also forms a cross- linked network and because of the ability for component (e)(ii) to penetrate and swell component (e)(i). The two networks physically entangle so that there is physical engagement rather than mere encapsulation. It was found that the lower the viscosity value of component (e)(ii) the greater the penetration and swelling of component (e)(i) occurred. Furthermore, penetration and swelling did not occur or occurred minimally when the component (e)(ii) had a zero-shear viscosity of greater 15,000 mPa.s at 25oC. Components (e)(i) and (e)(ii) were compatible, so there appeared to be no problems with component (e)(ii) penetrating into and swelling component (e)(i) providing the zero-shear viscosity of component (e)(ii) was within the range stated. However, given physically recycled and / or reclaimed condensation cured silicone elastomer particulates (e)(i) are thermoset materials and due to their crosslinked nature unable to dissolve in component (e)(ii). So, it instead swells to accommodate the organopolysiloxane polymer of component (e)(ii). The physically recycled and / or reclaimed condensation cured silicone elastomer particulates (e)(i) are thus physically well bound in the matrix and cannot serve as defects in the matrix, creating voids, surface protrusions or other heterogeneities which is often a problem when merely encapsulated and used as a filler. In a first embodiment the physically recycled and / or reclaimed condensation cured silicone elastomer particulates (e)(i) may be penetrated and soaked in organopolysiloxane polymer swelling agent (e)(ii) having a zero-shear viscosity of less than or equal to (≤) 15,000 mPa.s at 25oC for a suitable period of time. In this embodiment the organopolysiloxane polymer swelling agent (e)(ii) is preferably neat or unadulterated. The suitable period of time may be at least 1 hour, alternatively at least 12 hours, alternatively at least 24 hours, alternatively at least 48 hours. This enables said organopolysiloxane polymer swelling agent (e)(ii) to penetrate and swell said physically recycled and / or reclaimed condensation cured silicone elastomer particulates (e)(i) to form component (e). This equates to step (1) of the method above. Subsequently the resulting mixture of swollen (e)(i) and residual (e)(ii) are added to the curable high temperature vulcanizable (HTV) composition, especially in the case of a hydrosilylation curable silicone rubber composition or a part thereof, typically the Part B composition (as discussed elsewhere) which comprises step (2) in the above method. As indicated previously, alternatively steps (1), (2) and optionally (3) can alternatively be carried out simultaneously. In this embodiment component (e) may be prepared by swelling the physically recycled and / or reclaimed condensation cured silicone elastomer particulates (e)(i) in the hydrosilylation curable silicone rubber composition containing component (e)(ii) or more often in a part composition of the curable high temperature vulcanizable (HTV) composition, especially in the case of hydrosilylation curable silicone rubber compositions when being stored in multiple parts prior to use. In such an embodiment swelling can occur throughout the period during which particulates (e)(i) are stored in the presence of component (e)(ii) in said part of the curable high temperature vulcanizable (HTV) composition containing component (e)(ii). When the organopolysiloxane polymer swelling agent (e)(ii) is initially stored in one part of a two- part composition, e.g., in a Part B composition of a hydrosilylation cure composition, it may be present in an amount of from 2.wt. % to 10 wt. % of the part B composition prior to mixing in a 1 : 1 weight ratio with Part A. Typically, the part B composition of said hydrosilylation cure composition is used as it does not contain any catalyst the particulates may contain Si-H groups which could initiate some curing during storage if mixed with the catalyst. In this embodiment organopolysiloxane polymer swelling agent (e)(ii) may comprise or consist of component (d)(i) the cross-linker or at least 1.0 wt. % of component (a) or a mixture of both component (d)(i) and said at least 1.0 wt. % of component (a) or may be an organopolysiloxane polymer plasticiser, the particulates (e)(i) are swelled after being added to the relevant part of the composition containing component (e)(ii). For example, the swelling agent may be introduced into the Part B composition (described in more detail later) and the physically recycled and / or reclaimed condensation cured silicone elastomer particulates (e)(i) are swollen for a predetermined period of time in the Part B composition, after which the parts A and B compositions are mixed together and the composition is cured. Typically, physically recycled and / or reclaimed condensation cured silicone elastomer particulates (e)(i) will remain swollen by the presence of organopolysiloxane polymer swelling agent (e)(ii) throughout the lifetime of its use, even after cure. Swelled component (e) Typically said component (e), after component (e)(i) has been swelled by component (e)(ii) for a predetermined time, is present in an amount of from 5 wt. % to 80 wt. % of the composition, alternatively is present in an amount of from 5 wt. % to 50 wt. % of the composition, n, alternatively in an amount of from 7.5 wt. % to 35 wt. % of the composition, alternatively in an amount of from 7.5 wt. % to 30 wt. % of the composition, alternatively in an amount of from 9.0 wt. % to 25 wt. % of the composition. In addition to components (e)(i) and (e) (ii) the curable high temperature vulcanizable (HTV) composition comprises the following components: Component (a) Component (a) of the curable high temperature vulcanizable (HTV) composition is either: (i) an organopolysiloxane polymer having a zero-shear viscosity of between 100 and 200,000mPa.s inclusive at 25 ºC having at least two unsaturated groups per molecule, which unsaturated groups are selected from alkenyl and / or alkynyl groups; or (ii) an organopolysiloxane polymer gum having a Williams plasticity of from 75mm / 100 to 500mm / 100 measured in accordance with ASTM D926-08, having at least two unsaturated groups per molecule, which unsaturated groups are selected from alkenyl and / or alkynyl groups. Each organopolysiloxane polymer of component (a) comprises multiple siloxy units, of formula (I): R’aSiO(4-a) / 2 (I) Siloxy units may be described by a shorthand (abbreviated) nomenclature, namely - "M," "D," "T," and "Q", when R’ is as described above, alternatively an alkyl group, typically a methyl group. The M unit corresponds to a siloxy unit where a = 3, that is R’3SiO1 / 2; the D unit corresponds to a siloxy unit where a = 2, namely R’2SiO2 / 2; the T unit corresponds to a siloxy unit where a = 1, namely R’1SiO3 / 2; the Q unit corresponds to a siloxy unit where a = 0, namely SiO4 / 2. The organopolysiloxane polymer of component (a) is substantially linear but may contain a proportion of branching due to the presence of T units (as previously described) within the molecule, hence the average value of a in structure (I) is about 2. The unsaturated groups of component (a) may be positioned either terminally or pendently on the organopolysiloxane polymer, or in both locations. The unsaturated groups of component (a) may be alkenyl groups or alkynyl groups as described above. Each alkenyl group, when present, may comprise for example from 2 to 30, alternatively 2 to 24, alternatively 2 to 20, alternatively 2 to 12, alternatively 2 to 10, and alternatively 2 to 6 carbon atoms. When present the alkenyl groups may be exemplified by, but not limited to, vinyl, allyl, methallyl, propenyl, and hexenyl and cyclohexenyl groups. Each alkynyl group, when present, may also have 2 to 30, alternatively 2 to 24, alternatively 2 to 20, alternatively 2 to 12, alternatively 2 to 10, and alternatively 2 to 6 carbon atoms. Examples of alkynyl groups may be exemplified by, but not limited to, ethynyl, propynyl, and butynyl groups. Preferred examples of the unsaturated groups of component (a) include vinyl, propenyl, isopropenyl, butenyl, allyl, and 5-hexenyl. In formula (I), each R’, other than the unsaturated groups described above, is independently selected from an aliphatic hydrocarbyl group, a substituted aliphatic hydrocarbyl group, an aromatic group or a substituted aromatic group. Each aliphatic hydrocarbyl group may be exemplified by, but not limited to, alkyl groups having from 1 to 20 carbons per group, alternatively 1 to 15 carbons per group, alternatively 1 to 12 carbons per group, alternatively 1 to 10 carbons per group, alternatively 1 to 6 carbons per group or cycloalkyl groups such as cyclohexyl. Specific examples of alkyl groups may include methyl, ethyl, propyl, pentyl, octyl, undecyl, and octadecyl groups, alternatively methyl and ethyl groups. Substituted aliphatic hydrocarbyl group are preferably non-halogenated substituted alkyl groups. The aliphatic non-halogenated organyl groups are exemplified by, but not limited to alkyl groups as described above with a substituted group such as suitable nitrogen containing groups such as amido groups, imido groups; oxygen containing groups such as polyoxyalkylene groups, carbonyl groups, alkoxy groups and hydroxyl groups. Further organyl groups may include sulfur containing groups, phosphorus containing groups, boron containing groups. Examples of aromatic groups or substituted aromatic groups are phenyl groups and substituted phenyl groups with substituted groups as described above. Component (a) may, for example, be selected from polydimethylsiloxanes, alkylmethylpolysiloxanes, alkylarylpolysiloxanes or copolymers thereof (where reference to alkyl means any suitable alkyl group, alternatively an alkyl group having two or more carbons) providing each polymer has a viscosity of organopolysiloxane polymer (a) should be between 100 and 200,000mPa.s inclusive at 25 ºC, Hence component (a) may, for the sake of example, be: a dialkylalkenyl terminated polydimethylsiloxane, e.g., dimethylvinyl terminated polydimethylsiloxane; a dialkylalkenyl terminated dimethylmethylphenylsiloxane, e.g., dimethylvinyl terminated dimethylmethylphenylsiloxane; a trialkyl terminated dimethylmethylvinyl polysiloxane; a dialkylvinyl terminated dimethylmethylvinyl polysiloxane copolymer; a dialkylvinyl terminated methylphenylpolysiloxane, a dialkylalkenyl terminated methylvinylmethylphenylsiloxane; a dialkylalkenyl terminated methylvinyldiphenylsiloxane; a dialkylalkenyl terminated methylvinyl methylphenyl dimethylsiloxane; a trimethyl terminated methylvinyl methylphenylsiloxane; a trimethyl terminated methylvinyl diphenylsiloxane; or a trimethyl terminated methylvinyl methylphenyl dimethylsiloxane. In each case when the organopolysiloxane polymer of component (a) has a zero-shear viscosity of between 100 and 200,000mPa.s inclusive at 25 ºC and at least two unsaturated groups per molecule, which unsaturated groups are selected from alkenyl and / or alkynyl groups the viscosity of organopolysiloxane polymer (a) should be between 100 and 200,000mPa.s inclusive at 25 ºC, alternatively from 1000 to 150,000mPa.s at 25 ºC, alternatively, from 1000mPa.s to 125,000mPa.s, alternatively from 1000mPa.s to 100,000mPa.s at 25 ºC. These polymers are utilised in the making of “liquid silicone rubbers” (LSRs). Unless otherwise indicated all viscosity measurement given are zero-shear viscosity (ηo) values, obtained by extrapolating to zero the value taken at low shear rates (or simply taking an average of values) in the limit where the viscosity-shear rate curve is rate-independent, which is a test-method independent value provided a suitable, properly operating rheometer is used. For example, the zero- shear viscosity of a substance at 25 °C may be obtained by using commercial rheometers such as an Anton-Parr MCR-301 rheometer or a TA Instruments AR-2000 rheometer equipped with cone-and- plate fixtures of suitable diameter to generate adequate torque signal at a series of low shear rates, such as 0.01 s-1, 0.1 s-1and 1.0 s-1while not exceeding the torque limits of the transducer. Alternatively, the viscosity measurements may be obtained using an ARES-G2 rotational rheometer, commercially available from TA Instruments using a steady rate sweep from 0.1 to 10 s-1on a 25 mm cone and plate. If the zero-shear plateau region cannot be observed at shear rates accessible to the rheometer or viscometer, we report the viscosity measured at a standard shear rate of 0.1 s-1at 25 °C. Alternatively, the organopolysiloxane polymer of component (a) has a Williams plasticity of from75mm / 100 to 500mm / 100 measured in accordance with ASTM D926-08, having at least two unsaturated groups per molecule, which unsaturated groups are selected from alkenyl and / or alkynyl groups, Organopolysiloxane polymer gums have viscosity values of at least 1,000,000mPa.s at 25oC and often many millions of mPa.s at 25oC. Because of the difficulty in measuring viscosity at these values, gums tend to be described by way of their Williams plasticity values in accordance with ASTM D926-08 as opposed to by viscosity. Hence, when component (a) is an organopolysiloxane gum, the gum has a Williams’s plasticity of from 75mm / 100 to 500mm / 100 measured in accordance with ASTM D926-08, alternatively from 100mm / 100 to 450mm / 100 measured in accordance with ASTM D926-08, alternatively from 120mm / 100 to 400mm / 100 measured in accordance with ASTM D926-08, alternatively from 120mm / 100 to 375mm / 100 in accordance with ASTM D926-08. These gums are utilised in the making of high consistency silicone rubber materials (HCRs). Typically, the alkenyl and / or alkynyl content, e.g., vinyl content of the polymer is from 0.01 to 3 wt. % for each organopolysiloxane polymer containing at least two silicon-bonded alkenyl groups per molecule of component (a), alternatively from 0.01 to 2.5 wt. % of component (a), alternatively from 0.001 to 2.0 wt. %, alternatively from 0.01 to 1.5 wt. % of component (a) of the or each organopolysiloxane polymer containing at least two unsaturated groups per molecule, which unsaturated groups are selected from alkenyl and / or alkynyl groups per molecule of component (a). The alkenyl / alkynyl content of component (a) is determined using quantitative infra-red analysis in accordance with ASTM E168. Component (a) may be present in the curable high temperature vulcanizable (HTV) composition in an amount of from 40 wt. % to about 80 wt. % of the curable high temperature vulcanizable (HTV) composition, alternatively from 45 to 80 wt. % of the composition, alternatively from 50 to 80 wt. % of the curable high temperature vulcanizable (HTV) composition. Typically, component (a) is present in an amount which is the difference between 100 wt. % and the cumulative wt. % of the other components / ingredients of the composition. Component (b) (optional) Component (b) of the curable high temperature vulcanizable (HTV) composition is optional and is a reinforcing filler comprising fumed silica, precipitated silica or a mixture thereof. Finely divided forms of silica are preferred. The reinforcing filler is provided, when present, to reinforce the physical properties of the elastomers provided when the composition is cured. Reinforcing fillers (b) e.g., silica fillers having a relatively high surface area, typically at least 50 m² / g (BET method in accordance with ISO 9277: 2010) are utilized. For example, fillers, (e.g., fumed silica) having surface areas of from 50-450m2 / g, alternatively, 50 – 400m2 / g m2 / g, alternatively from 50 to 300 m² / g, alternatively 100 - 300m2 / g (BET method in accordance with ISO 9277: 2010) are typically used. Typically, the reinforcing filler(s) (b) is / are naturally hydrophilic (e.g., untreated) silica fillers, and are therefore treated with a treating agent to render it / them hydrophobic. These surface modified reinforcing fillers (b) do not clump and can be homogeneously incorporated into organopolysiloxane polymer (a), described below, as the surface treatment makes the fillers easily wetted by organopolysiloxane polymer (a). When present in the curable high temperature vulcanizable (HTV) composition the reinforcing filler (b) may be surface treated with any low molecular weight organosilicon compounds disclosed in the art applicable to prevent creping of organosiloxane compositions during processing. For example, organosilanes, polydiorganosiloxanes, or organosilazanes e.g., hexaalkyl disilazane, short chain siloxane diols or fatty acids or fatty acid esters such as stearates may be used to render the filler(s) hydrophobic and therefore easier to handle and obtain a homogeneous mixture with the other ingredients. Specific examples include but are not restricted to silanol terminated trifluoropropylmethyl siloxane, silanol terminated vinylmethylsiloxane, tetramethyldi(trifluoropropyl)disilazane, tetramethyldivinyl disilazane, hexamethyl disilazane (HMDZ), silanol terminated MePh siloxane, liquid hydroxyl-terminated polydiorganosiloxane containing an average from 2 to 20 repeating units of diorganosiloxane in each molecule, hexaorganodisiloxane, hexaorganodisilazane. A small amount of water can be added together with the silica treating agent(s) as a processing aid. The reinforcing silica fillers (b) may be pre-treated prior to introduction into the hydrosilylation curable silicone rubber composition or may be treated in situ (i.e., in the presence of at least a portion of the other ingredients of the hydrosilylation curable silicone rubber composition herein by blending these ingredients together at room temperature or above until the filler is completely treated. Typically, when present untreated reinforcing filler (b) is treated in situ with a treating agent in the presence of organopolysiloxane polymer (a) which results in the preparation of a silicone rubber base material which can subsequently be mixed with other ingredients. When the reinforcing filler (b) is present in the curable high temperature vulcanizable (HTV) composition in an amount of from 1.0 to 50wt. %. of the composition, alternatively of from 1 to 30wt. %. of the composition, alternatively of from 5.0 to 25wt. %. of the composition. Preferably the reinforcing filler (b) is present in the curable high temperature vulcanizable (HTV) composition. Component (c) Component (c) of the composition herein is a free-radical initiator, typically in the form of an organic peroxide. The organic peroxide free-radical initiator may be any of the well-known commercial peroxides used to cure high temperature vulcanizable (HTV) composition. Typically, the free-radical initiators are used to make high consistency rubber compositions in combination with the organopolysiloxane gums of component (a) and when present the reinforcing fillers of component (b). The amount of the free-radical initiators, e.g., organic peroxides used is determined by the nature of the curing process, the organic peroxide used, and the composition used. Typically, the amount of peroxide catalyst utilised in a composition as described herein is from 0.2 to 3 wt. %, alternatively 0.2 to 2 wt. % in each case based on the weight of the composition. Suitable organic peroxides which may be used as free radical initiators include but are not limited to substituted or unsubstituted dialkyl-, alkylaroyl-, diaroyl-peroxides, e.g., benzoyl peroxide and 2,4- dichlorobenzoyl peroxide, ditertiarybutyl peroxide, dicumyl peroxide, t- butyl cumyl peroxide, bis(t- butylperoxyisopropyl) benzene bis(t-butylperoxy)-2,5-dimethyl hexyne 2,4-dimethyl-2,5-di(t- butylperoxy) hexane, di-t-butyl peroxide and 2,5-bis(tert-butyl peroxy)-2,5-dimethylhexane. Mixtures of the above may also be used. Component (d) Component (d) of the curable high temperature vulcanizable (HTV) composition herein is a hydrosilylation catalyst package comprising (i) a polydiorganosiloxane polymer having at least 2, or at least 3 Si-H groups per molecule which is utilised as a cross-linker; and (ii) a hydrosilylation catalyst. Component (d)(i) Component (d)(i) of the curable high temperature vulcanizable (HTV) composition functions as a cross-linker and is provided in the form of an organosilicon compound having an average of at least two, alternatively at least three Si-H groups per molecule. Component (d)(i) normally contains three or more silicon-bonded hydrogen atoms so that the hydrogen atoms can react with the unsaturated groups (alkenyl and / or alkynyl groups) of component (a) and / or the rest of the composition to form a network structure therewith and thereby cure the composition. Some or all of Component (d)(i) may alternatively have two silicon bonded hydrogen atoms per molecule. However, such a molecule is only used as the sole cross-linker when e.g., polymer (a) has greater than two unsaturated groups per molecule in which case a network can be produced during the cure process. Otherwise, when component (d)(i) partially comprises molecules having an average of two silicon bonded hydrogen atoms per molecule, said molecules may function as a chain extender. The molecular configuration of the organosilicon compound having an average of at least two, alternatively at least three Si-H groups per molecule (d)(i) is not specifically restricted, and it can be a silane or a straight chain, branched (a straight chain with some branching through the presence of T units) or cyclic polymer or be silicone resin based. All viscosities are measured at 25oC and are zero-shear measurements using the method described previously. Silicon-bonded organic groups used in component (d)(i) may be exemplified by alkyl groups such as methyl, ethyl, propyl, n-butyl, t-butyl, pentyl, hexyl; aryl groups such as phenyl tolyl, xylyl, or similar aryl groups; 3-chloropropyl, 3,3,3-trifluoropropyl, or similar halogenated alkyl group, preferred alkyl groups having from 1 to 6 carbons, especially methyl ethyl or propyl groups or phenyl groups. Preferably the silicon-bonded organic groups used in component (d)(i) are alkyl groups, alternatively methyl, ethyl or propyl groups. Examples of the organosilicon compound having an average of at least two, alternatively at least three Si-H groups per molecule (d)(i) include but are not limited to: (a’) trimethylsiloxy-terminated methylhydrogenpolysiloxane, (b’) trimethylsiloxy-terminated polydimethylsiloxane-methylhydrogensiloxane, (c’) dimethylhydrogensiloxy-terminated dimethylsiloxane-methylhydrogensiloxane copolymers, (d’) dimethylsiloxane-methylhydrogensiloxane cyclic copolymers, (e’) copolymers and / or silicon resins consisting of (CH3)2HSiO1 / 2 units, (CH3)3SiO1 / 2 units and SiO4 / 2 units, (f’) copolymers and / or silicone resins consisting of (CH3)2HSiO1 / 2 units and SiO4 / 2 units, (g’) Methylhydrogensiloxane cyclic homopolymers having between 3 and 10 silicon atoms per molecule; alternatively, component (d)(i), the cross-linker, may be a filler, e.g., silica treated with one of the above, and mixtures thereof. In one embodiment the Component (d)(i) is selected from a methylhydrogenpolysiloxane capped at both molecular terminals with trimethylsiloxy groups; a copolymer of a methylhydrogensiloxane and a dimethylsiloxane capped at both molecular terminals with trimethylsiloxy groups; dimethylsiloxane capped at both molecular terminals with dimethylhydrogensiloxy groups; a copolymer of a methylhydrogensiloxane and a dimethylsiloxane capped at both molecular terminals with dimethylhydrogensiloxy groups. The cross-linker (d)(i) is generally present in the curable high temperature vulcanizable (HTV) composition, particularly a hydrosilylation curable silicone rubber composition such that the molar ratio of the silicon-bonded hydrogen atoms in component (d)(i) to the total unsaturated groups selected from alkenyl and / or alkynyl groups in the composition is from 0.5:1 to 20:1. When this ratio is less than 0.5:1, a well-cured composition will not be obtained. When the ratio exceeds 20:1, there is a tendency for the hardness of the cured curable high temperature vulcanizable (HTV) composition to increase when heated. The molar ratio of silicon-bonded hydrogen atoms of component (d)(i) to total unsaturated groups selected from alkenyl and / or alkynyl groups in the organopolysiloxane (a) is preferably at least 0.8:1, alternatively 1 : 1and can be up to 8:1 or 10:1. Most preferably the molar ratio of Si-H groups to aliphatically unsaturated groups is in the range from 1.1:1 to 5:1. The silicon-bonded hydrogen (Si-H) content of component (d)(i) is determined using quantitative infra-red analysis in accordance with ASTM E168. In the present instance the silicon-bonded hydrogen to alkenyl (vinyl) and / or alkynyl ratio is important when relying on a hydrosilylation cure process. Generally, this is determined by calculating the total weight % of alkenyl groups in the curable high temperature vulcanizable (HTV) composition e.g., a hydrosilylation curable silicone rubber composition e.g., vinyl [V] and the total weight % of silicon bonded hydrogen [H] in the composition and given the molecular weight of hydrogen is 1 and of vinyl is 27 the molar ratio of silicon bonded hydrogen to vinyl is 27[H] / [V]. Typically, dependent on the number of unsaturated groups in component (a) and the rest of the curable high temperature vulcanizable (HTV) composition e.g., a hydrosilylation curable silicone rubber composition as well as the number of Si-H groups in component (d)(i), component (d)(i) will be present in an amount of from 0.1 to 10 wt. % of the curable high temperature vulcanizable (HTV) composition, alternatively 0.1 to 7.5 wt. % of said curable high temperature vulcanizable (HTV) composition, alternatively 0.25 to 7.5wt. %, further alternatively from 0.25% to 5 wt. % of said curable high temperature vulcanizable (HTV) composition. (d)(ii) Hydrosilylation catalyst Component (d)(ii) of the curable high temperature vulcanizable (HTV) composition, e.g., a hydrosilylation curable silicone rubber composition, is a hydrosilylation catalyst comprising or consisting of a platinum group metal or a compound thereof. These are usually selected from catalysts of the platinum group of metals (platinum, ruthenium, osmium, rhodium, iridium and palladium), or a compound of one or more of such metals. Alternatively, platinum and rhodium compounds are preferred due to the high activity level of these catalysts in hydrosilylation reactions, with platinum compounds most preferred. In a hydrosilylation (or addition) reaction, a hydrosilylation catalyst such as component (d)(ii) herein catalyses the reaction between an unsaturated group, usually an alkenyl group e.g., vinyl with Si-H groups. The hydrosilylation catalyst of component (d)(ii) can be a platinum group metal, a platinum group metal deposited on a carrier, such as activated carbon, metal oxides, such as silicon dioxide, silica gel or powdered charcoal, or a compound or complex of a platinum group metal. Preferably the platinum group metal is platinum. Examples of preferred hydrosilylation catalysts of component (d)(ii) are platinum based catalysts, for example, platinum black, platinum oxide (Adams catalyst), platinum on various solid supports, chloroplatinic acids, e.g., hexachloroplatinic acid (Pt oxidation state IV) (Speier catalyst), chloroplatinic acid in solutions of alcohols e.g., isooctanol or amyl alcohol (Lamoreaux catalyst), and complexes of chloroplatinic acid with ethylenically unsaturated compounds such as olefins and organosiloxanes containing ethylenically unsaturated silicon-bonded hydrocarbon groups, e.g., tetra- vinyl-tetramethylcyclotetrasiloxane-platinum complex (Ashby catalyst). Soluble platinum compounds that can be used include, for example, the platinum-olefin complexes of the formulae (PtCl2.(olefin)2 and H(PtCl3.olefin), preference being given in this context to the use of alkenes having 2 to 8 carbon atoms, such as ethylene, propylene, isomers of butene and of octene, or cycloalkanes having 5 to 7 carbon atoms, such as cyclopentene, cyclohexene, and cycloheptene. Other soluble platinum catalysts are, for the sake of example a platinum-cyclopropane complex of the formula (PtCl2C3H6)2, the reaction products of hexachloroplatinic acid with alcohols, ethers, and aldehydes or mixtures thereof, or the reaction product of hexachloroplatinic acid and / or its conversion products with vinyl-containing siloxanes such as methylvinylcyclotetrasiloxane in the presence of sodium bicarbonate in ethanolic solution. Platinum catalysts with phosphorus, sulfur, and amine ligands can be used as well, e.g., (Ph3P)2PtCl2; and complexes of platinum with vinylsiloxanes, such as sym-divinyltetramethyldisiloxane (Karstedt’s catalyst). Hence, specific examples of suitable platinum-based catalysts of component (d)(ii) include: (i) complexes of chloroplatinic acid with organosiloxanes containing ethylenically unsaturated hydrocarbon groups are described in US 3,419,593; (ii) chloroplatinic acid, either in hexahydrate form or anhydrous form; (iii) a platinum-containing catalyst which is obtained by a method comprising reacting chloroplatinic acid with an aliphatically unsaturated organosilicon compound, such as divinyltetramethyldisiloxane; (iv) alkene-platinum-silyl complexes as described in US Pat. No.6,605,734 such as (COD)Pt(SiMeCl2)2where “COD” is 1,5-cyclooctadiene; and / or (v) Karstedt's catalyst, a platinum divinyl tetramethyl disiloxane complex typically containing about 1 wt. % of platinum typically in a vinyl siloxane polymer. Solvents such as toluene and the like organic solvents have been used historically as alternatives but the use of vinyl siloxane polymers by far the preferred choice. These are described in US3,715,334 and US3,814,730. In one preferred embodiment component (d)(ii) may be selected from co-ordination compounds of platinum. In one embodiment hexachloroplatinic acid and its conversion products with vinyl-containing siloxanes, Karstedt's catalysts and Speier catalysts are preferred. In one embodiment the catalyst may be encapsulated during storage, especially in the case of one-part compositions to prevent premature cure. The catalytic amount of the hydrosilylation catalyst is generally between 0.001 ppm, and 10,000 parts by weight of platinum-group metal, per million parts (ppm), based on the weight of the curable high temperature vulcanizable (HTV) composition; alternatively, between 0.1 and 7500ppm; alternatively, between 100 and 75000 ppm, and alternatively between 500 and 6,000 ppm. The ranges may relate solely to the metal content within the catalyst or to the catalyst altogether (including its ligands) as specified, but typically these ranges relate solely to the metal content within the catalyst. The catalyst may be added as a single species or as a mixture of two or more different species. Typically, dependent on the form / concentration in which the catalyst is provided e.g., in a polymer or solvent, the amount of component (d)(ii) present will be within the range of from 0.001 to 3.0 wt. % of the curable high temperature vulcanizable (HTV) composition, alternatively from 0.001 to 1.5 wt. % of the composition, alternatively from 0.01–1.5 wt. %, alternatively 0.01 to 0.1.0 wt. %, of the curable high temperature vulcanizable (HTV) composition e.g., a hydrosilylation curable silicone rubber composition. Components (a), and (d)(i), invariably consist of a mixture of macromolecular species with different degrees of polymerization and therefore of different molecular weights. There are different types of average polymer molecular weight, which can be measured in different experiments. The two most important are the number average molecular weight (Mn) and the weight average molecular weight (Mw). The Mn and Mw of a silicone polymer and / or resin can be determined by Gel permeation chromatography (GPC) using polystyrene calibration standards. This technique is standard and yields Mw, Mn and polydispersity index (PI). The degree of polymerisation (DP) =Mn / Mu where Mn is the number-average molecular weight coming from the GPC measurement and Mu is the molecular weight of a monomer unit. PI=Mw / Mn. The DP is linked to the viscosity of the polymer via Mw, the higher the DP, the higher the viscosity. The silicone polymer typically has a weight- average molecular weight (Mw) of from 2,000 to 50,000 Daltons, alternatively from 3,000 to 40,000, alternatively from 3,000 to 30,000, alternatively from 4,000 to 30,000, alternatively 5,000 to 25,000 where the molecular weight is determined by gel permeation chromatography employing a triple detector system e.g., light-scattering detector, a refractive index detector, and / or a viscosity detector and polystyrene standards. Additional optional ingredients Additional optional ingredients may be present in the curable high temperature vulcanizable (HTV) composition as hereinbefore described depending on the intended final use thereof. Examples of such optional ingredients include cure inhibitors, adhesion promoters, pot life extenders, flame retardants, lubricants, metal deactivators, non-reinforcing fillers, pigments and / or colouring agents, bactericides, wetting agents, heat stabilizers, compression set additives, plasticizers, silicone resins and mixtures thereof. Component (d)(i) may also be present in free-radical initiator cured HTV curable silicone rubber compositions. It is optional, as the stoichiometry of Si-H to ethylenically unsaturated groups is less critical and can extend beyond the ranges cited for hydrosilylation curable compositions and still provide effective curing. In these cases, generally smaller quantities of component (d)(i) may be used than when used in a hydrosilylation cure composition to assist with effective curing. The curable high temperature vulcanizable (HTV) composition as hereinbefore described may comprise a cure inhibitor to inhibit the cure of the composition when the composition is designed to be a hydrosilylation cure composition. These cure inhibitors are utilized to prevent premature cure in storage and / or to obtain a longer working time or pot life of a hydrosilylation cured composition by retarding or suppressing the activity of the catalyst. Cure inhibitors of hydrosilylation catalysts (d)(ii), e.g., platinum metal-based catalysts are well known in the art and may include hydrazines, triazoles, phosphines, mercaptans, organic nitrogen compounds, acetylenic alcohols, silylated acetylenic alcohols, maleates, such as dibutyl maleate; fumarates, ethylenically or aromatically unsaturated amides, ethylenically unsaturated isocyanates, olefinic siloxanes, such as tetramethyltetravinylcyclotetrasiloxane; unsaturated hydrocarbon monoesters and diesters, conjugated ene-ynes, hydroperoxides, nitriles, and diaziridines. Alkenyl-substituted siloxanes as described in US 3,989,667 may be used, of which cyclic methylvinylsiloxanes are preferred. One class of known cure inhibitors of hydrosilylation catalysts, e.g., platinum catalysts (d)(ii) include the acetylenic compounds disclosed in US 3,445,420. Acetylenic alcohols such as 2-methyl-3-butyn-2-ol constitute a preferred class of cure inhibitors that will suppress the activity of a platinum-containing catalyst at 25 ºC. Compositions containing these cure inhibitors typically require heating at temperature of 70 ºC or above to cure at a practical rate. Examples of acetylenic alcohols and their derivatives include 1-ethynyl-1-cyclohexanol (ETCH), 2- methyl-3-butyn-2-ol, 3-butyn-1-ol, 3-methyl butynol 3-butyn-2-ol, propargyl alcohol, 2-phenyl-2- propyn-1-ol, 3,5-dimethyl-1-hexyn-3-ol, 1-ethynylcyclopentanol, 1-phenyl-2-propynol, 3-methyl-1- penten-4-yn-3-ol, and mixtures thereof. In one alternative the cure inhibitor is selected from one or more of 1-ethynyl-1-cyclohexanol (ETCH), tetramethyltetravinylcyclotetrasiloxane, 3-methyl butynol and / or dibutyl maleate. When present, cure inhibitor concentrations as low as 1 mole of cure inhibitor per mole of the metal of catalyst (d)(ii) will in some instances impart satisfactory storage stability and cure rate. In other instances, cure inhibitor concentrations of up to 500 moles of cure inhibitor per mole of the metal of catalyst (d)(ii) are required. The optimum concentration for a given cure inhibitor in a given hydrosilylation curable silicone rubber composition herein is readily determined by routine experimentation. Mixtures of the above may also be used. Dependent on the concentration and form in which the cure inhibitor selected is provided / available commercially, when present in the composition, the cure inhibitor is typically present in an amount of from 0.0001-10wt. %, alternatively 0.001-5%, cure inhibitor, alternatively 0.0125 to 5wt. % of the composition. Adhesion promoters When present, any suitable adhesion promoter may be utilised if desired. The adhesion promoter may for example be an alkoxysilane coupling agent, Examples of adhesion promoters which may be incorporated in curable compositions according to the invention include alkoxysilanes such as aminoalkylalkoxysilanes, for example 3-aminopropyltriethoxysilane, epoxyalkylalkoxysilanes, for example, 3-glycidoxypropyltrimethoxysilane and, mercapto-alkylalkoxysilanes, and reaction products of ethylenediamine with silylacrylates. Isocyanurates containing silicon groups such as 1, 3, 5-tris(trialkoxysilylalkyl) isocyanurates may additionally be used. Further suitable adhesion promoters are reaction products of epoxyalkylalkoxysilanes such as 3- glycidoxypropyltrimethoxysilane with amino-substituted alkoxysilanes such as 3- aminopropyltrimethoxysilane and optionally with alkylalkoxysilanes such as methyltrimethoxysilane. When present, the adhesion promoter may be present in an amount of from 0.1 to 5.0 wt. % of the composition, alternatively from 0.1 to 3.5 wt. % of the composition alternatively from 0.1 to 2.5 wt. % of the composition, alternatively from 0.1 to 2.25 wt. % of the composition alternatively from 0.2 to 2.0 wt. % of the composition. Further suitable adhesion promoters are reaction products of epoxyalkylalkoxysilanes such as 3- glycidoxypropyltrimethoxysilane with amino-substituted alkoxysilanes such as 3- aminopropyltrimethoxysilane and optionally with alkylalkoxysilanes such as methyltrimethoxysilane. In one alternative the adhesion promoter may be a combination of an alkoxysilane coupling agent with an organometallic adhesion catalyst such as zirconium (IV) tetraacetyl acetonate, (sometimes referred to as zirconium AcAc4), or aluminium (III) triacetyl acetonate, (sometimes referred to as aluminium AcAc3). Typically, such a catalyst is introduced in an amount of from 0.05 – 0.3 wt.% of the composition. Pot life extenders, such as triazole, may be used, but are not considered necessary in the scope of the present invention. Curable high temperature vulcanizable (HTV) composition may thus be free of pot life extender. Examples of flame retardants include calcium carbonate, e.g., precipitated calcium carbonate, aluminium trihydrate (ATH), magnesium dihydroxide (MDH) and HMH (a mixture of hydromagnesite and huntite), chlorinated paraffins, hexabromocyclododecane, triphenyl phosphate, dimethyl methylphosphonate, tris(2,3-dibromopropyl) phosphate (brominated tris), and mixtures or derivatives thereof. When present in composition, if required the flame retardant may be present in an amount of from 5 to 50 wt. % of the composition. Examples of lubricants include tetrafluoroethylene, resin powder, graphite, fluorinated graphite, talc, boron nitride, fluorine oil, silicone oil, molybdenum disulfide, and mixtures or derivatives thereof. When present in the curable high temperature vulcanizable (HTV) composition, flame retardants are typically present in an amount of from 0.1 to 5% by weight of the composition. Non-reinforcing fillers may include crushed quartz, diatomaceous earths, barium sulphate, iron oxide, titanium dioxide precipitated calcium carbonate, ground calcium carbonate and carbon black, talc, wollastonite. Other fillers which might be used alone or in addition to the above include aluminite, calcium sulphate (anhydrite), gypsum, calcium sulphate, magnesium carbonate, clays such as kaolin, magnesium hydroxide e.g., brucite, graphite, copper carbonate, e.g., malachite, nickel carbonate, e.g., zarachite, barium carbonate, e.g., witherite and / or strontium carbonate e.g., strontianite. Other fillers may include silicates from the group consisting of olivine group; garnet group; aluminosilicates; ring silicates; chain silicates; and sheet silicates. The olivine group comprises silicate minerals, such as but not limited to, forsterite and Mg2SiO4. The garnet group comprises ground silicate minerals, such as but not limited to, pyrope; Mg3Al2Si3O12; grossular; and Ca2Al2Si3O12. Aluminosilicates comprise ground silicate minerals, such as but not limited to, sillimanite; Al2SiO5; mullite; 3Al2O3.2SiO2; kyanite; and Al2SiO5. Ring silicates may be utilized as non-reinforcing fillers, these include silicate minerals, such as but not limited to, cordierite and Al3(Mg,Fe)2[Si4AlO18]. The chain silicates group comprises ground silicate minerals, such as but not limited to, wollastonite and Ca[SiO3]. Sheet silicates may alternatively or additionally be used as non-reinforcing fillers where appropriate group comprises silicate minerals, such as but not limited to, mica; K2AI14[Si6Al2O20](OH)4; pyrophyllite; Al4[Si8O20](OH)4; talc; Mg6[Si8O20](OH)4; serpentine for example, asbestos; Kaolinite; Al4[Si4O10](OH)8; and vermiculite. Examples of pigments include titanium dioxide, chromium oxide, bismuth vanadium oxide, iron oxides and mixtures thereof. Examples of colouring agents for which may be utilized in the curable high temperature vulcanizable (HTV) composition include pigments, vat dyes, reactive dyes, acid dyes, chrome dyes, disperse dyes, cationic dyes and mixtures thereof. The curable high temperature vulcanizable (HTV) composition as described herein may further comprise one or more pigments and / or colorants which may be added if desired. The pigments and / or colorants may be coloured, white, black, metal effect, and luminescent e.g., fluorescent and phosphorescent. Pigments are utilized to colour the composition as required. Any suitable pigment may be utilized providing it is compatible with the composition herein. Suitable white pigments and / or colorants include titanium dioxide, zinc oxide, lead oxide, zinc sulfide, lithophone, zirconium oxide, and antimony oxide. Suitable non-white inorganic pigments and / or colorants include, but are not limited to, iron oxide pigments such as goethite, lepidocrocite, hematite, maghemite, and magnetite black iron oxide, yellow iron oxide, brown iron oxide, and red iron oxide; blue iron pigments; chromium oxide pigments; cadmium pigments such as cadmium yellow, cadmium red, and cadmium cinnabar; bismuth pigments such as bismuth vanadate and bismuth vanadate molybdate; mixed metal oxide pigments such as cobalt titanate green; chromate and molybdate pigments such as chromium yellow, molybdate red, and molybdate orange; ultramarine pigments; cobalt oxide pigments; nickel antimony titanates; lead chrome; carbon black; lampblack, and metal effect pigments such as aluminium, copper, copper oxide, bronze, stainless steel, nickel, zinc, and brass. Suitable organic non-white pigments and / or colorants include phthalocyanine pigments, e.g., phthalocyanine blue and phthalocyanine green; monoarylide yellow, diarylide yellow, benzimidazolone yellow, heterocyclic yellow, DAN orange, quinacridone pigments, e.g., quinacridone magenta and quinacridone violet; organic reds, including metallized azo reds and nonmetallized azo reds and other azo pigments, monoazo pigments, diazo pigments, azo pigment lakes, β-naphthol pigments, naphthol AS pigments, benzimidazolone pigments, diazo condensation pigment, isoindolinone, and isoindoline pigments, polycyclic pigments, perylene and perinone pigments, thioindigo pigments, anthrapyrimidone pigments, flavanthrone pigments, anthanthrone pigments, dioxazine pigments, triarylcarbonium pigments, quinophthalone pigments, and diketopyrrolo pyrrole pigments. Typically, the pigments and / or colorants, when particulates, have average particle diameters in the range of from 10 nm to 50 µm, preferably in the range of from 40 nm to 2 µm. The pigments and dyes may be used in form of pigment masterbatch composed of them dispersed in component (a) at the ratio of 25:75 to 70:30. The curable high temperature vulcanizable (HTV) composition may be heat stabilised. Examples of heat stabilizers may include metal compounds such as red iron oxide, yellow iron oxide, ferric hydroxide, cerium oxide, cerium hydroxide, lanthanum oxide, copper phthalocyanine, fumed titanium dioxide, iron naphthenate, cerium naphthenate, cerium dimethylpolysilanolate and acetylacetone salts of a metal chosen from copper, zinc, aluminum, iron, cerium, zirconium, titanium and the like. Other examples of heat stabilizers may include suitable antioxidants or metal scavengers such as salicyloylaminotriazole, 1,2-bis(3,5-di-tert-butyl-4- hydroxylhydrocinnamoyl)hydrazine, 2-Hydroxy-N-1H-1,2,4-triazol-3-ylbenzamide, and N’1,N’12- Bis(2-hydroxybenzoyl)dodecanedihydrazide. The amount of heat stabilizer when present in the curable high temperature vulcanizable (HTV) composition may range from 0.01 to 1.0 % weight of the curable high temperature vulcanizable (HTV) composition. Silicone Resins Silicone resins may optionally be incorporated in the curable high temperature vulcanizable (HTV) composition. These may be silicone resins containing unsaturated groups selected from alkenyl groups, alkynyl groups or a mixture of alkenyl groups and alkynyl groups, selected from T silicone resins (silsesquioxanes), DT silicone resins, MQ silicone resins, MDT silicone resins, MTQ silicone resins, QDT silicone resins or mixtures thereof. Such resins using the MDTQ notation comprise Q type (SiO4 / 2) siloxane units T type (R21SiO3 / 2) siloxane units; D type (R21SiO3 / 2) siloxane units and R2₃SiO1 / 2 (M) siloxane units as indicated. These resins can be classified into two broad categories: silsesquioxanes and silicates. Silsesquioxanes, or T resins, are predominantly comprised of T units and can be synthesized by the hydrolysis and condensation of alkoxysilanes, chlorosilanes, or mixtures thereof. Silicates, or MQ resins, are predominantly comprised of M and Q units and can be synthesized through the hydrolysis and condensation of alkoxysilanes and chlorosilanes. Alternatively, MQ resins can be synthesized through the polymerization of aqueous alkali silicates in the presence of acid followed by reaction with triorgano alkoxysilanes, triorgano chlorosilanes, hexaorganodisiloxanes or mixtures thereof. Preferably, when present a silicone resin is one or more MQ resins. Typically, the MQ resins when present, comprise SiO4 / 2(Q) siloxane units and R2₃SiO1 / 2(M) siloxane units wherein each R2may be the same or different and denotes a monovalent group selected from hydrocarbon groups, having from 1 to 20 carbon atoms and, alternatively from 1 to 12 carbon atoms. Examples of suitable R2groups include alkyl groups, such as methyl, ethyl, propyl, pentyl, octyl, undecyl and octadecyl; cycloaliphatic groups, such as cyclohexyl; alkenyl groups, having from 2 to 12 carbons, such as vinyl, propenyl, butenyl, pentenyl, hexenyl, and the like; alkynyl groups selected from ethynyl, propynyl, butynyl, pentynyl or hexynyl and the like; aryl groups such as phenyl, tolyl, xylyl, benzyl, alpha-methyl styryl and 2-phenylethyl; alternatively R2groups are vinyl, methyl, ethyl or phenyl groups, e.g., examples of preferred R2₃SiO1 / 2 (M) siloxane units include Me₃SiO1 / 2, PhMe₂SiO1 / 2, ViMe₂SiO1 / 2 and Ph₂MeSiO1 / 2, where Me hereinafter denotes methyl, Vi is vinyl and Ph hereinafter denotes phenyl. T silicone resins may alternatively be referred to as silsesquioxanes. The silicone resin can be a single silicone resin or a mixture comprising two or more different silicone resins, each as described above. Typically, they are MQ resins comprising ViMe₂SiO1 / 2In combination with Me₃SiO1 / 2, and / or PhMe₂SiO1 / 2 groups. Additionally, the silicone resin is an MQ resin which may contain residual OZ5, where Z5can represent hydrogen or alkyl groups. O Z5groups remain on the Q components after synthesis of silicone MQ resins indicative of incomplete condensation during the reaction to produce the MQ resin providing the OZ content meets the above hydroxyl per mole Si requirements. Residual O Z5is inherent to the processes and reactions utilized to make MQ resins. The MQ resin may also undergo a subsequent silylation reaction to further minimize residual O Z5. The silicone resin when present, is typically delivered in a hydrocarbon or silicone solvent, free from solvent the silicone resin is typically a solid but preferably herein the silicone resin is delivered in a silicone solvent such as a non-functional polydimethylsiloxane or a polydimethylsiloxane comprising two or more alkenyl groups per molecule, such as for example component (a) herein. For example, any suitable MQ resin may be utilized if required. The molar ratio of M siloxane units to Q siloxane units has a value of from 0.5:1 to 1.2:1, alternatively 0.6:1 to 1.1:1, alternatively 0.8:1 to 1.1:1, alternatively 0.9:1 to 1.1:1. In one embodiment MQ resin I includes a resinous portion wherein the M units are bonded to SiO4 / 2 siloxane units (i.e., Q units) and each of Q units is bonded to at least one other SiO4 / 2 siloxane unit. The molar ratio of M units to Q units is from 0.3 : 1 to 1.2 : 1, alternatively 0.4:1 to 1.1:1, alternatively 0.5:1 to 1:1, alternatively 0.6:1 to 0.9:1. Such an MQ resin) may have a number-average molecular weight (Mn) of from 2000 to 50,000g / mol, alternatively from 3,000 to 30,000 g / mol. In one embodiment the silicone resin may be described in the terms of a molar fraction as an MQ silicone resin having the formula: (R43SiO1 / 2)u(SiO4 / 2)v wherein R4is a C1 to C10 hydrocarbon group free of aliphatic unsaturation, u is from 0.3 to 0.6, alternatively 0.37 to 0.52, v is from 0.4 to 0.7, alternatively 0.48 to 0.63, and the value of u + v is 1.0. When present, a silicone resin as described above may be present in the curable high temperature vulcanizable (HTV) composition n an amount of from 1-60wt. %, alternatively 1-40wt. %, and is preferably in the form of an MQ resin. Hence the curable high temperature vulcanizable (HTV) composition comprises: a) an organopolysiloxane polymer having a zero-shear viscosity of between 100 and 200,000mPa.s inclusive at 25 ºC, alternatively from 1000 to150,000mPa.s at 25 ºC, alternatively, from 1000mPa.s to 125,000mPa.s, alternatively from 1000mPa.s to 70,000mPa.s at 25 ºC, having at least two unsaturated groups per molecule selected from alkenyl and / or alkynyl groups, or an organopolysiloxane polymer gum having a Williams plasticity of from 75mm / 100 to 500mm / 100 measured alternatively from 100mm / 100 to 450mm / 100, alternatively from 120mm / 100 to 400mm / 100, alternatively from 120mm / 100 to 375mm / 100 all in accordance with ASTM D926-08, having at least two unsaturated groups per molecule, which unsaturated groups are selected from alkenyl and / or alkynyl groups; in an amount of from 40 wt. % to about 80 wt. % of the composition, alternatively from 45 to 80 wt. % of the composition, alternatively from 50 to 80 wt. % of the composition of the composition; Unless otherwise indicated viscosity measurements given are all zero-shear viscosity (ηo) values determined as described above and in the examples at 25 °C. (b) optional reinforcing fillers comprising fumed silica, precipitated silica or a mixture thereof; having a particle size of at least 50 m² / g (BET method in accordance with ISO 9277: 2010) alternatively, 50-450m2 / g, alternatively, 50 – 400m2 / g m2 / g, alternatively from 50 to 300 m² / g, alternatively 100 – 300m2 / g (BET method in accordance with ISO 9277: 2010); said reinforcing fillers (b) are typically treated to render them hydrophobic and are present in an amount of from 1.0 to 50wt. %. Of the composition, alternatively of from 1 to 30wt. %. of the composition, alternatively of from 5.0 to 25wt. %. based on the weight % of the composition; either (c) or (d) wherein (c) Is a free radical initiator catalyst utilised in a composition as described herein in an amount of from 0.2 to 3 wt. %, of the composition, alternatively 0.2 to 2 wt. % in each case based on the weight of the composition such as substituted or unsubstituted dialkyl-, alkylaroyl-, diaroyl-peroxides, e.g., benzoyl peroxide and 2,4-dichlorobenzoyl peroxide, ditertiarybutyl peroxide, dicumyl peroxide, t- butyl cumyl peroxide, bis(t- butylperoxyisopropyl) benzene bis(t-butylperoxy)-2,5-dimethyl hexyne 2,4-dimethyl- 2,5-di(t- butylperoxy) hexane, di-t-butyl peroxide and 2,5-bis(tert-butyl peroxy)-2,5- dimethylhexane. Mixtures of the above may also be used. (d) Is a hydrosilylation catalyst package comprising (d)(i) an organosilicon compound having an average of at least two or alternatively an average of at least three Si-H groups per molecule, preferably wherein the molar ratio of the silicon-bonded hydrogen atoms in component (d)(i) to the total unsaturated groups selected from alkenyl and / or alkynyl groups in the composition is from 0.5:1 to 20:1, alternatively the molar ratio of silicon- bonded hydrogen atoms of component (d)(i) to the total unsaturated groups selected from alkenyl and / or alkynyl groups in the organopolysiloxane (a) is preferably at least 0.8:1 and can be up to 8:1 or 10:1. Most preferably the molar ratio of Si-H groups to aliphatically unsaturated groups is in the range from 1.1:1 to 5:1; said organosilicon compound having an average of at least two, alternatively at least three Si-H groups per molecule being present in an amount of from 0.1 to 10 wt. % of the curable high temperature vulcanizable (HTV) composition e.g., a hydrosilylation curable silicone rubber composition, alternatively 0.1 to 7.5wt. % of the curable high temperature vulcanizable (HTV) composition, alternatively 0.5 to 7.5wt. %, further alternatively from 0.5% to 5 wt. % of curable high temperature vulcanizable (HTV) composition. Component (d)(i) functions as a cross-linker; and (d) (ii) a hydrosilylation catalyst; and (d)(ii) a hydrosilylation cure catalyst wherein the catalytic amount of the hydrosilylation catalyst is between 0.01 ppm, and 10,000 parts by weight of platinum-group metal, per million parts (ppm), based on the weight of the curable high temperature vulcanizable (HTV) composition; alternatively, between 0.1 and 7500ppm; alternatively, between 100 and 75000 ppm, and alternatively between 500 and 6,000 ppm of metal based on the weight of the composition and wherein dependent on the form / concentration in which the catalyst is provided e.g., in a polymer or solvent, the amount of component (d)(ii) present will be within the range of from 0.001 to 3.0 wt. % of the composition, alternatively from 0.001 to 1.5 wt. % of the composition, alternatively from 0.01–1.5 wt. %, alternatively 0.01 to 0.1.0 wt. %, of the curable high temperature vulcanizable (HTV) composition; and (e) physically recycled and / or reclaimed condensation cured silicone elastomer particulates (e)(i) having an average unswollen particle size of 1 mm or less, which physically recycled and / or reclaimed condensation cured silicone elastomer particulates (e)(i) have been penetrated and swollen by an organopolysiloxane polymer swelling agent (e)(ii) having a zero-shear viscosity of less than or equal to (≤) 15,000 mPa.s at 25 C; said component (e) after component (e)(i) has been swelled by component (e)(ii), for a predetermined time, is present in the composition in an amount of from 7.5 wt. % to 30 wt. % of the composition, alternatively in an amount of from 7.5 wt. % to 25 wt. % of the composition, alternatively in an amount of from 9.0 wt. % to 20 wt. % of the composition.The composition may also include one or more of the optional additives described above as and when required. The total wt. % (weight %) of the composition is 100wt. %. The curable high temperature vulcanizable (HTV) composition may be a hydrosilylation cure composition comprising components (a), (d), (e) and optionally (b) or a free radical activated composition comprising components (a), (c) (e) and optionally (b). Typically, when the curable high temperature vulcanizable (HTV) composition is a hydrosilylation curable silicone rubber composition, prior to use the hydrosilylation curable silicone rubber composition utilised herein is stored in two parts, Part A and Part B to keep components (d)(i) cross- linker and (d)(ii) hydrosilylation cure catalyst apart to avoid premature cure. Typically, a Part A composition will comprise components (a) polymer, (b) reinforcing filler and (d)(ii) hydrosilylation cure catalyst and Part B will comprise components (a), reinforcing filler (b), cross-linker (d)(i), and optional cure inhibitor, when present. Component (e) may be introduced into the Part B composition after the particulates (e)(i) have been pre-swollen by (e)(ii). Alternatively, particulates (e)(i) may undergo the swelling step in the Part B composition. In such a case the swelling agent (e)(ii) being utilised is mixed into the Part B composition typically before the addition of particulates (e)(i). In one alternative, when some of component (a) has a sufficiently low viscosity (i.e., less than 15,000mPa.s) said component (a) may be utilised to function as component (e)(ii), in which case component (e)(i) can be added directly into the Part B composition and be allowed to swell for a period of time. When component (e)(i) and component (e)(ii) are mixed together in a pre-mix, the pre-mix of component (e) may, once said period of time allowed for swelling component (e)(i) has expired, be added directly into Part B or may be kept separately in a Part C composition alone or with additional component (a) which Part C is then mixed into the final composition simultaneously to when parts A and B are mixed together. Other optional additives (i.e., other than cure inhibitor when present in a hydrosilylation curable silicone rubber composition may be in either Part A or Part B, providing they do not negatively affect the properties of any other components present (e.g., catalyst inactivation). Part A and Part B of the hydrosilylation curable silicone rubber composition described herein are mixed together shortly prior to use to initiate cure of the full composition into a silicone elastomeric material. The Part A and Part B compositions (and optional Part C containing component (e)) can be designed to be mixed in any suitable weight ratio e.g., Part A : Part B may be mixed together in weight ratios of from 10:1 to 1:10, alternatively from 5:1 to 1:5, alternatively from 2:1 to 1:2, but most preferred is a weight ratio of 1:1. The ingredients of the Part A composition and the ingredients of the Part B may be respectively mixed together in any suitable manner with components being introduced individually or may be introduced into the composition in pre-prepared combinations for, e.g., ease of mixing the final composition. For example, components (a) and (b) when present are often mixed together to form a polymer base or masterbatch with silica optionally being treated in situ, prior to addition with other ingredients. Similarly, component (e) may also be premixed with component (a), if desired. These may then be mixed with the other ingredients of Part B made directly or may be used to make pre-prepared concentrates commonly referred to in the industry as masterbatches. Any mixing techniques and devices described in the prior art can be used for making the Part A and Part B compositions. The particular device to be used will be determined by the viscosities of components and the final composition. Suitable mixers include but are not limited to paddle type mixers e.g., planetary mixers and kneader type mixers. Cooling of components during mixing may be desirable to avoid premature curing of the composition. The curable high temperature vulcanizable (HTV) composition as hereinbefore described may be placed in a mold or applied onto a substrate or the like prior to cure by any suitable known technique. Curing of the curable high temperature vulcanizable (HTV) composition can take place in a mold to form a molded part, by injection molding, using e.g., a liquid injection molding system (LIMS) press moulding, extrusion moulding, transfer moulding, press vulcanization, or calendaring. The curable high temperature vulcanizable (HTV) composition is cured at any suitable temperature e.g., at a temperature of from 100oC to 200oC, alternatively from about 100oC to 180oC, alternatively from about 120oC to 180oC. However, when the curable high temperature vulcanizable (HTV) composition is a hydrosilylation curable silicone rubber composition, the cure temperature can be less than 100oC when appropriate ingredients make up the composition. The cured materials made from the compositions herein may be used for example in or as airbag coatings, gaskets and seals, adhesives, coatings, molded rubber articles, hoses and tubing like medical tubing, encapsulants and potting agents or the like. For example, in one alternative the curable high temperature vulcanizable (HTV) composition may be in the form of a hydrosilylation curable silicone rubber composition which may be coated onto a substrate such as an airbag by spraying, gravure coating, bar coating, knife coating, e.g., coating by knife-over-roller, coating by knife-over-air; padding, dipping and screen-printing. For example, a hydrosilylation curable silicone rubber composition can be applied onto one or both sides of a textile or fabric material substrate, e.g., an airbag fabric which is to be cut into pieces and sewn to assemble an airbag or may be applied onto a one-piece woven airbag. Curing of such a hydrosilylation curable silicone composition applied onto the woven fabric is typically conducted by heating the composition at a temperature of from 150 to 200°C for 45 seconds to 2 minutes which can be accomplished using a suitable oven or through drying tunnel of circulating hot-air ovens. Examples In the following examples, the compositions are defined in weight % (wt. %) unless otherwise stated. Vinyl group and silicone bonded hydrogen (Si-H) content was measured by Infrared spectroscopy in accordance with ASTM E168 using standards of the carbon double bond stretch and silicon- hydrogen bond stretch respectively. Unless otherwise indicated all viscosity measurement given are zero-shear viscosity (ηo) values, obtained by extrapolating to zero the value taken at low shear rates (or simply taking an average of values) in the limit where the viscosity-shear rate curve is rate-independent, which is a test-method independent value provided a suitable, properly operating rheometer is used. For example, the zero- shear viscosity of a substance at 25 °C may be obtained by using commercial rheometers such as an Anton-Parr MCR-301 rheometer or a TA Instruments AR-2000 rheometer equipped with cone-and- plate fixtures of suitable diameter to generate adequate torque signal at a series of low shear rates, such as 0.01 s-1, 0.1 s-1and 1.0 s-1while not exceeding the torque limits of the transducer. Alternatively, the viscosity measurements may be obtained using an ARES-G2 rotational rheometer, commercially available from TA Instruments using a steady rate sweep from 0.1 to 10 s-1on a 25 mm cone and plate. If the zero-shear plateau region cannot be observed at shear rates accessible to the rheometer or viscometer, we report the viscosity measured at a standard shear rate of 0.1 s-1at 25 °C. All viscosity measurements were taken at 25oC unless otherwise indicated. All Shore hardness measurements were measured using either the Shore A method or the Shore 00 method as defined ASTM D2240-15 dependent on the apparent softness, with the Shore 00 method being used for softer elastomers. Swelling Reference Example In order to show that low viscosity organopolysiloxane polymers will swell a condensation cured silicone elastomer, when the elastomer is soaked / immersed in a low viscosity organopolysiloxane polymer, the following experiment was undertaken. A slab of a condensation cured two-part sealant composition cured using a tin catalyst was prepared was prepared following the instructions supplied with the product for mixing the two-part compositions provided. Three 1-inch x 1-inch x 0.08 inches (2.54cm x 2.54 cm x 2mm) rectangular samples were cut from the slabs. The three rectangular samples were immersed in three dimethylvinyl terminated polydimethylsiloxane having different viscosities, the first fluid had an approximate zero-shear viscosity of 30mPa.s, the second fluid had an approximate zero-shear viscosity of 430mPa.s and the third fluid had an approximate zero-shear viscosity of 44,000mPa.s in each case zero-shear values measured as described above at 25oC. Each sample remained immersed in the respective fluid for 24 hours after which they were analysed for changes. It was found that the sample immersed in 44,000mPa.s gained no mass and did not change in size. The sample soaked in 430 mPa.s fluid had an 8% increase in mass and size. The sample immersed in 30 mPa.s fluid had a 30% increase in mass and size. Hence, it can be seen the swelling does take place when the samples are immersed / soaked in low viscosity organopolysiloxane polymers. Laboratory Preparation of particulates In one example, cured condensation cured silicone elastomer block samples were shredded with a paper shredder and cut with scissors until they were of a predetermined size of less than 2cm particle size. They were then fed into a MikroTMUMP-B mill commercially available from Hosokawa Micron Corporation. The shredded / cut rubber samples were mixed with dry ice (the dry ice had been previously crushed to a powder using mortar and pestle) in a weight ratio of approximately 1:1 in order to reduce the temperature of the rubber and help stiffen it for milling. The condensation cured silicone elastomer / dry ice mixture was then fed into the mill using a knife blade rotor rotating at an rpm of > 10,000. The rubber was then allowed to leave the milling chamber through a stainless-steel screen when it was cut finer than the hole size of the screen. The screen had 2-3 mm diameter round holes for a first pass. The condensation cured silicone elastomer milled in the first pass was then subjected to a second pass with dry ice again as before and fed through the MikroTMUMP-B mill for a second pass this time using a 1mm slotted screen. Analytical Assessment of Particle Size The particle size distribution of the milled condensation cured silicone elastomer particulates was measured using laser diffraction. A Beckman CoulterTMLS 13320 Particle Size Analyzer with the Tornado (dry) module was used. Approximately 25 mL of a milled bulk solids sample was added into a vial, which was placed in the LS 13320 Tornado module which was then activated. When activated, the Tornado module automatically vacuumed the sample past a laser and the diffraction signal of the sample was measured. Beckman CoulterTMsoftware then used to deconvolute the diffraction signal to a particle size distribution determined using Fraunhofer diffraction model. A curable high temperature vulcanizable (HTV) composition in the form of a hydrosilylation curable silicone rubber composition was prepared using the composition depicted in Table 1. Table 1: hydrosilylation curable silicone rubber composition (LSR 1) (wt. %) Part A Part B Vinyldimethylsiloxy terminated polydimethylsiloxane having a zero-shear 79.57 70.08 T e S ore A ardness o t e above once cured was about 10 and as suc t was cons dered t at any samples which had a lower hardness would not be captured properly using the Shore A scale and as such it was decided to measure other samples based on the 00 Scale, in order to gauge the effects of different additives more precisely on the hardness values. The reactive swelling agent was vinyldimethyl terminated polydimethylsiloxane having a zero-shear viscosity of about 450mPa.s. The cross-linker used in the above composition was a trimethyl terminated methylhydrogen dimethylsiloxane polymer having a zero-shear viscosity of about 5 mPa.s. In Ref.1, and Ex.1 to 2 the Part B composition depicted in Table 1 was prepared. The relevant physically recycled and / or reclaimed particulates as indicated from Table 2 below were introduced into the part B compositions of Ex.1 and 2 and the particulates were allowed to swell by interaction with the reactive swelling agent in the Part B composition. Table 2: Part B compositions of Ref.1, Ex.1 and 2 and compositions including particulates in Ex.1 and 2 (in parts by weight per 100 parts by weight of the Part B composition) Ingredient type Ref.1 Ex.1 Ex.2 Part B composition of liquid silicone rubber (Table 1) 100 100 100 the Part B composition. Physically recycled and / or reclaimed condensation cured silicone rubber 1 particulates were prepared from an unfilled 2-part titanium cured room temperature vulcanizate sealant having a Shore 00 hardness of about 40. The sealant was cured in a sheet at ambient laboratory conditions for a minimum of 30 days. Physically recycled and / or reclaimed condensation cured silicone rubber 2 particulates were prepared from a calcium carbonate containing 2-part tin-cured room temperature vulcanizate sealant having a Shore A hardness of about 40. Swelling took place for approximately 24 hours. After completion of the swelling step the resulting mixture containing 100 parts by weight of the Part B composition incorporating the swelled particulates was inter-mixed with 100 parts by weight of the part A composition of LSR 1 (a Part A: Part B weight ratio of 1 : 1 excluding the particulates) resulting in there being equivalent to about 10 wt. % (unswelled weight) of particulates in the total composition of Part A + Part B. The resulting curable high temperature vulcanizable (HTV) composition in the form of a hydrosilylation curable silicone rubber composition was cured by compression molding rectangular slabs of dimensions 5 in by 5 in by 0.08 in (12.7cm x 12.7 cm x 0.2 mm) of the different compositions at 150 °C for 10 minutes. Subsequent to cure, cured samples were analysed for their physical properties in accordance with the ASTM methods described below and the results are depicted in Tables 3a (Shore 00 Hardness) and 3b (tensile testing). For the tensile testing, tensile bars with a 40 mm gauge length were cut from the rectangular slab using a metal die, otherwise tensile strength, elongation at break and modulus at 100% elongation results were determined in accordance with ASTM D412. Five replicates were performed for each sample. Table 3a: Shore 00 hardness of Ref.1 and Ex.1 and 2 (ASTM D2240-15) Shore 00 Hardness Ref.1 71 Modulus (MPa) at % value of Elongation % value Tensile % value 100% extension M100 of at break of E of Strength of TS of new silicone rubber composition alone (Ref.1). The high elongations at break and tensile strengths belie the successful curing of these compositions comprising physically recycled and / or reclaimed condensation cured elastomer particulates in hydrosilylation cured systems, demonstrating that no or minimal poisoning of the Pt based catalyst was observed. A further comparative example was contemplated as a means of depicting dual curing a mixture of a condensation curable RTV composition and a Pt-catalyzed hydrosilylation curable liquid silicone rubber, but it was decided that this could not be undertaken safely without a risk of generating large amounts of explosive hydrogen gas. Hence, in our view the ability to obtain cured materials at all from Ex.1 and Ex.2 in a safe manner was considered surprising and unexpected, much less cured rubbers with such high tensile properties as shown in Table 3b.

Claims

CLAIMS 1. A curable high temperature vulcanizable (HTV) silicone rubber composition comprising : a) an organopolysiloxane polymer having a zero-shear viscosity of between 100 and 200,000mPa.s inclusive at 25 ºC having at least two unsaturated groups per molecule, which unsaturated groups are selected from alkenyl and / or alkynyl groups, or an organopolysiloxane polymer gum having a Williams plasticity of from 75mm / 100 to 500mm / 100 measured in accordance with ASTM D926-08, having at least two unsaturated groups per molecule, which unsaturated groups are selected from alkenyl and / or alkynyl groups; b) optionally reinforcing fillers comprising fumed silica, precipitated silica or a mixture thereof; either (c) or (d) wherein (c) is a free radical initiator; or (d) Is a hydrosilylation catalyst package comprising (i) an organosilicon compound having an average of at least two or alternatively an average of at least three Si-H groups per molecule; and (ii) a hydrosilylation catalyst; and e) physically recycled and / or reclaimed condensation cured silicone elastomer particulates (e)(i) having an average unswollen particle size of 1 mm or less, which physically recycled and / or reclaimed condensation cured silicone elastomer particulates (e)(i) have been penetrated and swollen by an organopolysiloxane polymer swelling agent (e)(ii) having a zero-shear viscosity of less than or equal to 15,000 mPa.s at 25oC.

2. A curable high temperature vulcanizable (HTV) silicone rubber composition in accordance with claim 1 wherein physically recycled and / or reclaimed condensation cured silicone elastomer particulates (e)(i) are obtained from condensation cured (RTV) silicone elastomers.

3. A curable high temperature vulcanizable (HTV) silicone rubber composition in accordance with claim 2 wherein physically recycled and / or reclaimed silicone condensation cured silicone elastomer particulates (e)(i) were obtained from adhesives, refrigerant spacers, potting agents, coatings and sealants.

4. A curable high temperature vulcanizable (HTV) silicone rubber composition in accordance with claim 1, 2 or 3 wherein component (e)(ii) has a zero-shear viscosity of from 100 to 5,000mPa.s at 25oC.

5. A curable high temperature vulcanizable (HTV) silicone rubber composition in accordance with claim 1, 2, 3 or 4 wherein the composition comprises an adhesion promoter selected from alkoxysilanes epoxyalkylalkoxysilanes, and, mercapto-alkylalkoxysilanes, reaction products of ethylenediamine with silylacrylates; Isocyanurates containing silicon groups; reaction products of epoxyalkylalkoxysilanes amino-substituted alkoxysilanes and optionally with alkylalkoxysilanes; or a combination of an alkoxysilane coupling agent with an organometallic adhesion catalyst.

6. A curable high temperature vulcanizable (HTV) silicone rubber composition in accordance with claim 1, 2, 3, 4 or 5 wherein the composition additionally comprises one or more of the group selected from cure inhibitors, pot life extenders, flame retardants, lubricants, metal deactivators, non-reinforcing fillers, pigments and / or colouring agents, bactericides, wetting agents, heat stabilizers, compression set additives, plasticizers, silicone resins and mixtures thereof.

7. A curable high temperature vulcanizable (HTV) silicone rubber composition in accordance with claim 1, 2, 3, 4, 5 or 6 wherein the physically recycled and / or reclaimed condensation cured silicone elastomer particulates (e)(i) having an average unswollen particle size of 600µm or less.

8. A curable high temperature vulcanizable (HTV) composition in accordance with any preceding claim which is a hydrosilylation cure composition comprising components (a), (d), (e) and optionally (b) or a free radical activated composition comprising components (a), (c) (e) and optionally (b).

9. A method of preparing a curable high temperature vulcanizable (HTV) composition comprising the steps of (1) mixing physically recycled and / or reclaimed condensation cured silicone elastomer particulates (e)(i) having an average unswollen particle size of 1 mm or less, with an organopolysiloxane polymer swelling agent (e)(ii) having a zero-shear viscosity of less than or equal to 15,000 mPa.s at 25oC to enable said organopolysiloxane polymer swelling agent (e)(ii) to penetrate and swell said physically recycled and / or reclaimed condensation cured silicone elastomer particulates (e)(i) to form component (e); (2) forming a step (2) mixture comprising at least part of component (a) with component (e) and optionally one or more of components (b) and (c) or (d); wherein a) an organopolysiloxane polymer having a zero-shear viscosity of between 100 and 200,000mPa.s inclusive at 25 ºC having at least two unsaturated groups per molecule, which unsaturated groups are selected from alkenyl and / or alkynyl groups, or an organopolysiloxane polymer gum having a Williams plasticity of from 75mm / 100 to 500mm / 100 measured in accordance with ASTM D926- 08, having at least two unsaturated groups per molecule, which unsaturated groups are selected from alkenyl and / or alkynyl groups; b) optionally reinforcing fillers comprising fumed silica, precipitated silica or a mixture thereof; either (c) or (d) wherein (c) is a free radical initiator; or (d) is a hydrosilylation catalyst package comprising (i) an organosilicon compound having an average of at least two or alternatively an average of at least three Si-H groups per molecule; and (ii) a hydrosilylation catalyst; (3) mixing the step (2) mixture with the remainder of components (b) and (c) or (d); to produce a hydrosilylation curable silicone rubber composition.

10. A method of preparing a curable high temperature vulcanizable (HTV) silicone rubber composition in accordance with claim 9 wherein step (1), step (2) and optionally step (3) are undertaken together as a single step.

11. A method of preparing a curable high temperature vulcanizable (HTV) silicone rubber composition in accordance with claim 9 or 10 wherein component (e)(i) are physically recycled and / or reclaimed silicone elastomer particulates (e)(i) obtained from condensation cured (RTV) silicone elastomers.

12. A method of preparing a curable high temperature vulcanizable (HTV) silicone rubber composition in accordance with claim 11 wherein the physically recycled and / or reclaimed silicone elastomer particulates (e)(i) are prepared by grinding, milling, or pulverizing silicone elastomers into particulates.

13. A method of preparing a curable high temperature vulcanizable (HTV) silicone rubber composition in accordance with claim in accordance with claim 9, 10, 11 or 12 wherein component (e)(ii) has a zero-shear viscosity of from 100 to 5,000mPa.s at 25oC.

14. A method of preparing a curable high temperature vulcanizable (HTV) silicone rubber composition in accordance with claim 9, 10, 11, 12 or 13 wherein the composition is a hydrosilylation curable composition comprising components (a), (d), (e) and optionally (b) or a free radical activated composition comprising components (a), (c) (e) and optionally (b).

15. A cured product of a curable high temperature vulcanizable (HTV) silicone rubber composition obtained in accordance with the method of any one of claims 9, 10, 11, 12, 13 or 14.

16. A use of physically recycled and / or reclaimed condensation cured silicone elastomer particulates (e)(i) having an average unswollen particle size of 1 mm or less, which physically recycled and / or reclaimed condensation cured silicone elastomer particulates (e)(i) have been penetrated and swollen by an organopolysiloxane polymer swelling agent (e)(ii) having a zero-shear viscosity of less than or equal to (≤) 15,000 mPa.s at 25oC; in a high temperature vulcanizable (HTV) composition otherwise comprising: a) an organopolysiloxane polymer having a zero-shear viscosity of between 100 and 200,000mPa.s inclusive at 25 ºC having at least two unsaturated groups per molecule, which unsaturated groups are selected from alkenyl and / or alkynyl groups, or an organopolysiloxane polymer gum having a Williams plasticity of from 75mm / 100 to 500mm / 100 measured in accordance with ASTM D926- 08, having at least two unsaturated groups per molecule, which unsaturated groups are selected from alkenyl and / or alkynyl groups; b) optionally reinforcing fillers comprising fumed silica, precipitated silica or a mixture thereof; either (c) or (d) wherein (c) is a free radical initiator; or (d) is a hydrosilylation catalyst package comprising(i) an organosilicon compound having an average of at least two or alternatively an average of at least three Si-H groups per molecule; and (ii) a hydrosilylation catalyst; in the preparation of a curable high temperature vulcanizable (HTV) composition.

17. Use in accordance with claim 16 wherein the curable high temperature vulcanizable (HTV) composition is a hydrosilylation curable composition comprising components (a), (d), (e) and optionally (b) or a free radical activated composition comprising components (a), (c), (e) and optionally (b).

18. Use of a curable high temperature vulcanizable (HTV) silicone rubber composition in accordance with any one of claim 1 to 8 in or as airbag coatings, gaskets and seals, adhesives, coatings, molded rubber articles, hoses, tubing encapsulants and potting agents.

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