Application of heat-conducting organic silicon rubber

Abstract

A fabric-reinforced thermally conductive silicone rubber tube, the fabric-reinforced thermally conductive silicone rubber tube comprising (A) a first inner layer being a thermally conductive silicone rubber tube in the form of an extruded cured product of a hydrosilylated (addition) curable thermally conductive silicone rubber composition; (B) a second intermediate layer covering a reinforcing fabric of the tube (A), the reinforcing fabric being selected from the group consisting of glass fiber fabrics, polyester fiber fabrics, polyamide fiber fabrics and / or aramid fiber fabrics or a reinforcing fabric comprising a mixture of any two or more thereof; and (C) a third outer layer which is a thermally conductive silicone rubber tube in the form of an extrusion cured product of a hydrosilylated (addition) curable thermally conductive silicone rubber composition on the second intermediate layer (B); wherein the first inner layer (A) and the third outer layer (C) are each made of a cured product of the hydrosilylated (addition) curable thermally conductive silicone rubber composition.

Description

[0001] The present disclosure relates to fabric-reinforced thermally conductive silicone rubber tubing suitable for use in liquid (e.g., water) cooling systems. These tubings preferably have a thermal conductivity of at least 0.5 Watts / meter Kelvin (W / mK) while being capable of withstanding fluid (e.g., water) pressures exceeding 1 MPa. The present disclosure also relates to a method for manufacturing the fabric-reinforced thermally conductive silicone rubber tubing and, by extension, to the uses of such tubing.

[0002] The properties of cured silicone-based products, including organosilicone elastomers, make them ideal for a variety of end-use applications, including in the field of electronics and other forms of electrical applications. Compositions that produce cured silicone-based products can, for example, be used to coat solid-state electronic devices and, upon curing, encapsulate solid-state electronic devices such as transistors and integrated circuits, as well as the circuit boards on which these devices are typically mounted, to protect them from contact with moisture, corrosive materials, and other impurities present in the environments in which these devices operate. However, while organosiloxane compositions and the resulting cured silicone-based products are effective in protecting solid-state devices from materials that can adversely affect their operation, they generally do not possess the thermal conductivity required to dissipate the large amounts of heat generated during such uses.

[0003] One way to increase heat dissipation is to increase the thermal conductivity of the material used to coat or encapsulate solid-state devices by adding thermally conductive fillers (sometimes referred to as thermally conductive fillers) such as metal powders (e.g., silver, nickel, and copper) and carbonaceous powders (such as carbon black, graphite powder, and / or carbon fibers) to the coating or encapsulation material. However, such compositions can encounter various problems, particularly because high levels of such fillers are required to produce high thermal conductivities of, for example, at least 0.5 W / mK (measured according to ASTM D7896-hot disk method). Such high thermal conductivities are achieved by increasing the amount of thermally conductive fillers in the corresponding compositions, but the presence of such fillers in amounts of, for example, greater than 70% or 75% by weight (wt.%) of the composition typically results in a significant increase in the viscosity of the pre-cured composition, resulting in impaired handling characteristics, and in addition, after curing, the physical properties of the cured silicone-based product are poor because the vast majority of thermally conductive fillers do not have a reinforcing effect, i.e., the addition of thermally conductive fillers does not enhance the mechanical properties of the cured silicone-based product. Although such cured silicone-based products may be acceptable for some applications, there is an increasing need in the industry for compositions that produce cured materials having the following two properties:

[0004] (i) the required high level of thermal conductivity, and

[0005] (ii) the required level of physical properties,

[0006] While previously, only one of these options might have been desired. Solutions to (i) have been identified, but at the expense of adequate physical properties. For example, the high viscosity of pre-cured compositions due to the presence of thermally conductive fillers can be avoided by diluting the composition with a non-reactive silicone or organic solvent, but this has been found to lead to compatibility issues with the diluent leaching out of subsequently cured silicone-based products over time. Furthermore, such products have historically failed to meet customer physical property requirements. Similarly, when compared to silicone elastomers containing optimized amounts of reinforcing fillers, etc., the physical properties (e.g., tensile strength and elasticity) of cured materials with such high levels of thermally conductive, non-reinforcing fillers are relatively poor and / or inconsistent, thus limiting their potential use. Without such physical properties, the ability of cured silicone materials to function for extended periods in many of their preferred applications (e.g., as gaskets, encapsulants, or in shock absorbing pads) is hampered by such undesirable consequences, which can lead to failure.

[0007] PCT / CN2022 / 114896 provides a thermally conductive high-consistency silicone rubber (HCR) composition comprising a thermally conductive filler having a volume median particle size of 0.1 to 100 microns (μm) measured by laser diffraction particle size analysis, in an amount of 80 to 95% by weight of the composition, typically 85 to 90% by weight of the composition. Aluminum oxide (also referred to as aluminum hydroxide) is found to be particularly suitable for molding thermally conductive silicone rubber parts using a compression molding process. However, it is generally found that it is not suitable for extrusion applications because the composition is too soft and / or has too low William's plasticity, resulting in the inability to form a consistently acceptable extruded component for a liquid cooling system, such as a tube (and / or pipe), which is used, for example, in fast charging equipment for electric vehicles.

[0008] The growing popularity of electric vehicles (EVs) and hybrid electric vehicles (HEVs) has led to a dramatic increase in research and development of EV charging infrastructure. The three biggest issues that remain problematic for EV drivers and hinder the use of EV vehicles for long-distance travel are:

[0009] (i) Lack of charging infrastructure,

[0010] (ii) the distance that can be travelled before recharging is required and

[0011] (iii) Time required for recharging.

[0012] While there are various methods for recharging EV batteries, the development of the aforementioned "fast charging" technology has become increasingly important as it is increasing the speed at which vehicles can be charged. However, they generate a large amount of heat, which leads to the problem of how to extract the heat generated in the charging cable from the high voltage and / or current utilized. The solution is to use liquid cooling systems, which are designed to cool the charging equipment and cables using a low-temperature liquid passing through liquid cooling tubes. The cooling tubes are positioned near the charging cable, and a low-temperature liquid (e.g., water) is designed to flow through the cooling tubes so that the charging cable can be cooled and / or the fast charging equipment can be maintained at a safe temperature, with the heat generated being transferred to the cooling liquid through the tube walls. Given the heat generated, the cooling liquid (e.g., water) is typically transported through the tubes at a high pressure (e.g., greater than (>) 1 MPa), which necessitates that the tubes be able to transfer the generated heat through the tube walls to the cooling liquid and be structurally reliable enough to avoid tube rupture due to the fluid pressure of the cooling liquid passing through the tubes. However, currently commercial materials used to form such tubes, such as cross-linked polyolefins (XLPO) for cooling tubes, are not suitable for long-term durability and conformability at high temperatures because tubes made from XLPO are believed to be much stiffer and therefore much less flexible than silicone elastomers, and furthermore, XLPO products such as tubes cannot match the heat resistance properties of silicone elastomers at temperatures above (>) 150°C for long-term applications.

[0013] This article provides a fabric-reinforced thermally conductive silicone rubber tube, which includes

[0014] (A) a first inner layer, which is a thermally conductive silicone rubber tube in the form of an extruded cured product of a hydrosilylation (addition)-curable thermally conductive silicone rubber composition;

[0015] (B) a second intermediate layer of a reinforcing fabric covering the tube (A), the reinforcing fabric being selected from glass fiber fabric, polyester fiber fabric, polyamide fiber fabric and / or polyaramid fiber fabric or a reinforcing fabric comprising a mixture of any two or more thereof; and

[0016] (C) a third outer layer, which is a thermally conductive silicone rubber tube in the form of an extruded cured product of a hydrosilylation (addition)-curable thermally conductive silicone rubber composition on the second intermediate layer (B);

[0017] The first inner layer (A) and the third outer layer (C) are both made of a cured product of a hydrosilylation (addition) curable thermally conductive silicone rubber composition comprising the following components:

[0018] a) a polydiorganosiloxane having a degree of polymerization of at least 2,500 calculated from a number average molecular weight determined by gel permeation chromatography and at least two unsaturated groups per molecule, the unsaturated groups being selected from alkenyl groups or alkynyl groups;

[0019] b) an organosilicon compound having at least two, alternatively at least three Si—H groups per molecule,

[0020] c) an organopolysiloxane filler treating agent having a degree of polymerization of between 4 and 500 calculated from the number average molecular weight determined by gel permeation chromatography and comprising:

[0021] (i) at least one alkenyl group per molecule, and

[0022] (ii) at least one hydroxyl group or at least one alkoxy group, or a mixture of hydroxyl groups and alkoxy groups per molecule;

[0023] The amount thereof is 0.1% to 10% by weight of the composition;

[0024] d) a hydrosilylation catalyst comprising or consisting of a platinum group metal or a compound thereof; and

[0025] (e)(i) at least one thermally conductive filler having a volume median particle size of 0.1 to 20 micrometers (μm) as measured by laser diffraction particle size analysis, in an amount of 70 to 95 weight percent, alternatively 80 to 95 weight percent, of the composition; or

[0026] (e) A combination of (ii) and (f), where

[0027] (e)(ii) is at least one thermally conductive filler having a volume median particle size greater than 20 micrometers to 100 micrometers (μm) as measured by laser diffraction particle size analysis and

[0028] f) precipitated silica, fumed silica, colloidal silica, or a mixture of any two or more of precipitated silica, colloidal silica, and fumed silica in an amount from greater than 0% to 5% by weight of the composition;

[0029] wherein the combination of (e)(ii) + (f) is present in the composition in an amount from 70 wt% to 95 wt% of the composition, alternatively from 80 wt% to 95 wt% of the composition, and wherein the total wt% of the composition is 100 wt%.

[0030] This article also provides a method for preparing a fabric-reinforced thermally conductive silicone rubber tube, which comprises the following steps:

[0031] 1) preparing a hydrosilylation (addition) curable thermally conductive silicone rubber composition comprising the following components:

[0032] a) a polydiorganosiloxane having a degree of polymerization of at least 2,500 calculated from a number average molecular weight determined by gel permeation chromatography and at least two unsaturated groups per molecule, the unsaturated groups being selected from alkenyl groups or alkynyl groups;

[0033] b) an organosilicon compound having at least two, alternatively at least three Si—H groups per molecule,

[0034] c) an organopolysiloxane filler treating agent having a degree of polymerization of between 4 and 500 calculated from the number average molecular weight determined by gel permeation chromatography and comprising:

[0035] (i) at least one alkenyl group per molecule, and

[0036] (ii) at least one hydroxyl group or at least one alkoxy group, or a mixture of hydroxyl groups and alkoxy groups per molecule;

[0037] The amount thereof is 0.1% to 10% by weight of the composition;

[0038] d) a hydrosilylation catalyst comprising or consisting of a platinum group metal or a compound thereof; and

[0039] (e)(i) at least one thermally conductive filler having a volume median particle size of 0.1 to 20 micrometers (μm) as measured by laser diffraction particle size analysis, in an amount of 70 to 95 weight percent, alternatively 80 to 95 weight percent, of the composition; or

[0040] (e) A combination of (ii) and (f), where

[0041] (e)(ii) is at least one thermally conductive filler having a volume median particle size greater than 20 micrometers to 100 micrometers (μm) as measured by laser diffraction particle size analysis and

[0042] f) precipitated silica, fumed silica, colloidal silica, or a mixture of any two or more of precipitated silica, colloidal silica, and fumed silica in an amount from greater than 0% to 5% by weight of the composition;

[0043] wherein the combination of (e)(ii) + (f) is present in the composition in an amount from 70% to 95% by weight of the composition, alternatively from 80% to 95% by weight of the composition, and wherein the total wt% of the composition is 100% by weight;

[0044] II) introducing a hydrosilylation (addition) curable thermally conductive silicone rubber composition into an extruder, extruding the hydrosilylation (addition) curable thermally conductive silicone rubber composition from the extruder to form a thermally conductive silicone rubber tube (A) and cooling the tube;

[0045] III) covering the tube produced by step (II) with a layer (B) of a reinforcing fabric selected from glass fiber fabric, polyester fiber fabric, polyamide fiber fabric and / or polyaramid fiber fabric or a reinforcing fabric comprising a mixture of any two or more thereof to form a step (III) product;

[0046] IV) extruding an outer layer (C) of the hydrosilylation (addition)-curable thermally conductive silicone rubber composition surrounding the product of step (III) from an extruder to form a fabric-reinforced thermally conductive silicone rubber tube.

[0047] This article also provides a fabric-reinforced thermally conductive silicone rubber tube, which is prepared according to the above method.

[0048] A use of a thermally conductive organosilicon rubber composition, the thermally conductive organosilicon rubber composition comprising the following components:

[0049] a) a polydiorganosiloxane having a degree of polymerization of at least 2,500 calculated from a number average molecular weight determined by gel permeation chromatography and at least two unsaturated groups per molecule, the unsaturated groups being selected from alkenyl groups or alkynyl groups;

[0050] b) an organosilicon compound having at least two, alternatively at least three Si—H groups per molecule,

[0051] c) an organopolysiloxane filler treating agent having a degree of polymerization of between 4 and 500 calculated from the number average molecular weight determined by gel permeation chromatography and comprising:

[0052] (i) at least one alkenyl group per molecule, and

[0053] (ii) at least one hydroxyl group or at least one alkoxy group, or a mixture of hydroxyl groups and alkoxy groups per molecule;

[0054] an amount ranging from 0.1% to 10% by weight of the composition; and

[0055] d) a hydrosilylation catalyst comprising or consisting of a platinum group metal or a compound thereof; and

[0056] (e)(i) at least one thermally conductive filler having a volume median particle size of 0.1 to 20 micrometers (μm) as measured by laser diffraction particle size analysis, in an amount of 70 to 95 weight percent, alternatively 80 to 95 weight percent, of the composition; or

[0057] (e) A combination of (ii) and (f), where

[0058] (e)(ii) is at least one thermally conductive filler having a volume median particle size greater than 20 micrometers to 100 micrometers (μm) as measured by laser diffraction particle size analysis and

[0059] f) precipitated silica, fumed silica, colloidal silica, or a mixture of any two or more of precipitated silica, colloidal silica, and fumed silica in an amount from greater than 0% to 5% by weight of the composition;

[0060] wherein the combination of (e)(ii) + (f) is present in the composition in an amount from 70% to 95% by weight of the composition, alternatively from 80% to 95% by weight of the composition, and wherein the total wt% of the composition is 100% by weight;

[0061] In the manufacture of a fabric-reinforced thermally conductive organic silicone rubber tube, the fabric-reinforced thermally conductive organic silicone rubber tube comprises

[0062] (A) a first inner layer, which is a thermally conductive silicone rubber tube in the form of an extruded cured product of the hydrosilylation (addition)-curable thermally conductive silicone rubber composition;

[0063] (B) a second intermediate layer of a reinforcing fabric covering the tube (A), the reinforcing fabric being selected from glass fiber fabric, polyester fiber fabric, polyamide fiber fabric and / or polyaramid fiber fabric or a reinforcing fabric comprising a mixture of any two or more thereof; and

[0064] (C) A third outer layer, which is a thermally conductive silicone rubber tube in the form of an extruded cured product of the hydrosilylation (addition)-curable thermally conductive silicone rubber composition on the second intermediate layer (B).

[0065] The fabric reinforced thermally conductive silicone rubber tube herein may have a circular, rectangular, i.e., square, or oval cross-section as determined by the desired end use, but typically has a circular cross-section that may have any suitable size, typically having an inner diameter (ID) of the hollow interior of 1.0 mm to 20.0 mm, alternatively 2 mm to 15 mm, alternatively 2 mm to 10 mm, alternatively 2 mm to 8 mm, alternatively 2 mm to 6 mm.

[0066] The tube may have any suitable wall thickness (WT) depending on the thickness of its three layers and an outer diameter (OD) which is therefore the sum of ID + 2WT.

[0067] The fabric-reinforced thermally conductive silicone rubber tube must be sufficiently strong to withstand the (fluid) pressure from the liquid (e.g., water) passing through the hollow interior of the tube during use. That is, the fabric-reinforced thermally conductive silicone rubber tube must not be subjected to a fluid pressure (i.e., water pressure) exceeding a "rupture pressure" that would cause the tube to rupture. Typically, for example, where the tube herein is used to improve the safety of an EV charging cable water cooling system, such a fabric-reinforced thermally conductive silicone rubber tube must be sufficiently flexible for use while being able to withstand fluid pressure, such as a water pressure greater than (>) 1.0 MPa according to the Chinese National Standard Test Method GB / T5563-2013. However, given that the tube herein is a thermally conductive silicone rubber tube, additional requirements exist, as it is important to ensure that the tube has sufficient thermal conductivity. Therefore, where the tube herein is used in an EV charging cable water cooling system, the tube of such a fabric-reinforced thermally conductive silicone rubber tube must also exceed a thermal conductivity of at least 0.5 W / mK. Typically, the fabric-reinforced thermally conductive silicone rubber tubing described herein produced from the thermally conductive silicone rubber composition comprising at least 70 wt. % of the thermally conductive filler (e)(i) or (e)(ii) described herein (in combination with (f)) will have a high thermal conductivity of at least 0.5 W / mK as measured according to ASTM D7896 - Hot Disc Method.

[0068] Furthermore, when used as a tube for an EV charging cable water cooling system, such a fabric-reinforced thermally conductive silicone rubber tube may have a wall thickness (WT) of 0.5 mm to 10.0 mm so as to be accommodated in a standard-sized EV charging cable as a water cooling system. For example, the first inner layer (A) of the fabric-reinforced thermally conductive silicone rubber tube may have a wall thickness of 0.25 mm to 7.5 mm, alternatively 0.50 mm to 5.0 mm, and the third outer layer (C) of the fabric-reinforced thermally conductive silicone rubber tube may have a wall thickness of 0.25 mm to 7.5 mm, alternatively 0.50 mm to 5.0 mm. For example, in one embodiment, when the tube herein is used as a cooling tube for a 24 mm (OD) EV charging cable water cooling system, the first inner layer (A) may have a wall thickness of 0.6 mm to 0.8 mm, and the third outer layer (C) may have a wall thickness of 0.4 mm to 0.6 mm.

[0069] Tubes prepared by extruding a single layer of the hydrosilylation (addition) curable thermally conductive silicone rubber composition described herein were found to be sufficiently flexible and strong enough to be extruded into a single-layer tube having, for example, a WT of 1 to 2 mm. However, when water was directed through the tube during a water pressure test, such tubes in this form were subjected to fluid pressure, for example, greater than (>) 1.0 MPa according to the Chinese National Standard Test Method GB / T5563-2013.

[0070] This problem is surprisingly overcome by the tubes described in the present disclosure by replacing the single layer tube with a fabric reinforced thermally conductive silicone rubber tube as described herein and prepared using the methods described herein.

[0071] Fabric layer B provides additional strength to the resulting cured fabric-reinforced thermally conductive silicone rubber tube. The reinforcing fabric used for intermediate layer B may include any suitable fabric or combination of fabrics. The fabric layer may include one or more suitable synthetic fibers, such as, for example, glass fiber fabric, polyester fiber fabric (such as polyethylene terephthalate), polyamide fiber fabric, and / or polyaramid fiber fabric, or any other suitable reinforcing fabric comprising two or more thereof. Fabric layer B may be provided and utilized in any suitable form. For example, it may be provided in any suitable woven, non-woven, or knitted form. The fabric is used to cover inner layer A in any suitable manner, for example, if desired, this may include winding or knitting or any other suitable method, or indeed a combination of two or more methods. Optional examples preferably use any suitable mesh size (e.g., 14*14 mesh, 10*10 mesh, 8*8 mesh, 5*5 mesh, i.e., the number of meshes per inch (2.54 cm) in the warp and weft) wound or knitted around inner tube A.

[0072] It was found that this fabric-reinforced thermally conductive silicone rubber hose achieved and maintained all of the desired parameters described above, and therefore the fabric-reinforced thermally conductive silicone rubber hose is considered suitable as a cooling tube positioned next to the charging cable in a fast-charging device for EV applications. When cold water was directed through the tube during the hydrostatic test of rubber and plastic hoses and hose assemblies according to the Chinese National Standard Test Method GB / T5563-2013, the fabric-reinforced thermally conductive silicone rubber hose was strong enough to withstand higher fluid pressures of >1.0 MPa to cool the EV charging cable. This is highly beneficial because it appears that current commercial materials (such as cross-linked polyolefins used for cooling tubes) have questionable long-term durability and conformability under high temperature conditions. The fabric-reinforced thermally conductive silicone rubber hoses as described herein and prepared by the methods described herein have improved parameters, among which good flexibility and sufficient mechanical strength make them a potentially better choice in terms of heat resistance for cooling tubes.

[0073] The fabric-reinforced thermally conductive silicone rubber tubing described herein and prepared by the methods described herein utilizes two layers of thermally conductive silicone rubber prepared by extruding and curing a hydrosilylation (addition)-curable thermally conductive silicone rubber composition comprising:

[0074] Component (a)

[0075] Component (a) of the hydrosilylation (addition)-curable thermally conductive silicone rubber composition used to prepare the fabric-reinforced thermally conductive silicone rubber tube described herein is a polydiorganosiloxane having a degree of polymerization of at least 2,500 and at least two unsaturated groups per molecule, the unsaturated groups being selected from alkenyl groups and / or alkynyl groups.

[0076] Thus, each polydiorganosiloxane of component (a) has a degree of polymerization of at least 2,500, alternatively at least 3,500, alternatively at least 4000, i.e., thus has at least 2,500, alternatively at least 3,500, alternatively at least 4000 siloxy units of formula (I):

[0077] R' a SiO (4-a) / 2 (I)

[0078] The subscript "a" is 0, 1, 2, or 3.

[0079] When R' is, for example, an independently selected substituted or unsubstituted hydrocarbyl group having 1 to 18 carbon atoms, alternatively an alkyl group (typically a methyl group), the siloxy unit can be described by a shorthand (abbreviated) nomenclature, i.e., - "M," "D," "T," and "Q" (further teaching on organosilicon nomenclature can be found in Walter Noll, Chemistry and Technology of Silicones, 1962, Chapter 1, pp. 1-9). The M unit corresponds to a siloxy unit, where a = 3, i.e., R'3SiO 1 / 2 ; D unit corresponds to a siloxy unit, where a = 2, ie R'2SiO 2 / 2 ; T unit corresponds to a siloxy unit, where a = 1, ie R'1SiO 3 / 2 ; Q unit corresponds to a siloxy unit, where a = 0, i.e. SiO 4 / 2 Polyorganosiloxanes such as the polydiorganosiloxane of component (a) are substantially linear but may contain a certain proportion of branches due to the presence of T units (as previously described) within the molecule, so that the average value of a in structure (I) is about 2.

[0080] The unsaturated groups of component (a) can be positioned on the end or side chain of polydiorganosiloxane, or be positioned on these two positions.The unsaturated groups of component (a) can be alkenyl groups or alkynyl groups as described above.When present, each alkenyl group can comprise, for example, 2 to 30, alternatively 2 to 24, alternatively 2 to 20, alternatively 2 to 12, alternatively 2 to 10, alternatively 2 to 6 carbon atoms.When present, alkenyl groups can be exemplified by, but not limited to, vinyl, allyl, methallyl, propenyl and hexenyl and cyclohexenyl groups.When present, each alkynyl group can also have 2 to 30, alternatively 2 to 24, alternatively 2 to 20, alternatively 2 to 12, alternatively 2 to 10, alternatively 2 to 6 carbon atoms.The example of alkynyl groups can be exemplified by, but not limited to, ethynyl, propynyl and butynyl groups. Preferred examples of the unsaturated group of component (a) include a vinyl group, an isopropenyl group, an allyl group, and a 5-hexenyl group.

[0081] In formula (I), except above-mentioned unsaturated groups, each R ' is the substituted or unsubstituted alkyl group with 1 to 18 carbon atoms that independently selects.These groups can be selected individually from aliphatic alkyl group, substituted aliphatic alkyl group, aromatic group or substituted aromatic group.Each aliphatic alkyl group can be by following but not limited to following illustration: there is 1 to 20 carbon / group, alternatively 1 to 15 carbon / group, alternatively 1 to 12 carbon / group, alternatively 1 to 10 carbon / group, alternatively 1 to 6 carbon / group alkyl group or cycloalkyl group, such as cyclohexyl.The specific example of alkyl group can comprise methyl, ethyl, propyl group, amyl group, octyl group, undecyl and octadecyl group, alternatively methyl and ethyl group.The aliphatic alkyl group that replaces is preferably the alkyl group of non-halogenation replacement.

[0082] Aliphatic non-halogenated organic groups are exemplified by, but not limited to, the above-mentioned alkyl groups with substituted groups, such as suitable nitrogen-containing groups such as acylamino groups, imino groups; oxygen-containing groups (such as polyoxyalkylene groups, carbonyl groups, alkoxy groups, and hydroxyl groups). Additional organic groups may include sulfur-containing groups, phosphorus-containing groups, and boron-containing groups. Examples of aromatic groups or substituted aromatic groups are phenyl groups and substituted phenyl groups with substituted groups as described above.

[0083] Component (a) can be, for example, selected from polydimethylsiloxanes, alkylmethylpolysiloxanes, alkylarylpolysiloxanes, or copolymers thereof (wherein reference to alkyl refers to any suitable alkyl group, alternatively an alkyl group having two or more carbons), provided that each polymer contains at least two unsaturated groups, typically alkenyl groups as described above, and has a degree of polymerization of at least 2,500. They can, for example, be trialkyl-terminated, alkenyldialkyl-terminated, alkynyldialkyl-terminated, or can be terminated with any other suitable combination of end groups, provided that each polymer contains the required at least two unsaturated groups per molecule and a degree of polymerization of at least 2,500.

[0084] Thus, for example, component (a) may be:

[0085] Dialkyl alkenyl terminated polydimethylsiloxanes, such as dimethylvinyl terminated polydimethylsiloxanes; dialkyl alkenyl terminated dimethylmethylphenylsiloxanes, such as dimethylvinyl terminated dimethylmethylphenylsiloxanes; trialkyl terminated dimethylmethylvinyl polysiloxanes; dialkyl vinyl terminated dimethylmethylvinyl polysiloxane copolymers; dialkyl vinyl terminated methylphenyl polysiloxanes, dialkyl alkenyl terminated methylvinylmethylphenylsiloxanes;

[0086] Dialkyl alkenyl terminated methylvinyl diphenyl siloxane; dialkyl alkenyl terminated methylvinyl methylphenyl dimethyl siloxane; trimethyl terminated methylvinyl methylphenyl siloxane; trimethyl terminated methylvinyl diphenyl siloxane; or trimethyl terminated methylvinyl methylphenyl dimethyl siloxane.

[0087] In each case, component (a) has a degree of polymerization (DP) of at least 2,500, alternatively at least 3,500, alternatively at least 4000. Since polydiorganosiloxane polymers of this magnitude have very high viscosities and high molecular weights (at least 1,000,000 mPa.s at 25°C, typically several million mPa.s at 25°C), they are often referred to in the industry as polydiorganosiloxane gums, silicone gums, or silicone gels (hereinafter referred to as silicone gels), and therefore have a high DP of, for example, at least 2500, taking into account the degree of polymerization (DP) calculated from the number average molecular weight of the polymer. Since it is difficult to measure the viscosity of highly viscous polymers such as silicone gels, gums are often defined by their Williams plasticity value rather than viscosity. When component (a) is a silicone gum, the gum has a Williams plasticity of at least 30 mm / 100 measured according to ASTM D-926-08, alternatively at least 50 mm / 100 measured according to ASTM D-926-08, alternatively at least 100 mm / 100 measured according to ASTM D-926-08. Typically, silicone gums have a Williams plasticity of about 100 mm / 100 to 300 mm / 100 measured according to ASTM D-926-08, but some silicone gums may have greater values.

[0088] The number average molecular weight and weight average molecular weight of such polymers are usually determined by gel permeation chromatography using polystyrene standards. In the present disclosure, the number average molecular weight and weight average molecular weight values ​​of the organosilicon used as component (a) herein are measured using a Waters 2695 separation module (Waters Corporation, MA, USA) equipped with a vacuum degasser and a Waters 2414 refractive index detector. Analyzed using certified toluene flowing at 1.0 mL / min as eluent. Data collection and analysis are performed using Waters Empower GPC software.

[0089] The degree of polymerization of a polymer is approximately the number average molecular weight of the polymer divided by 74 (the molecular weight of one component (I) described above).

[0090] Typically, the polymer has an alkenyl and / or alkynyl content (e.g., vinyl content) of from 0.01% to 3% by weight for each polydiorganosiloxane containing at least two silicon-bonded alkenyl groups per molecule of component (a), alternatively from 0.01% to 2.5% by weight of component (a) per molecule of the polydiorganosiloxane or each polydiorganosiloxane containing at least two unsaturated groups selected from alkenyl groups or alkynyl groups per molecule of component (a), alternatively from 0.01% to 1.5% by weight of component (a). The alkenyl / alkynyl content of component (a) is determined using quantitative infrared analysis according to ASTM E168.

[0091] Component (a) can be present in the composition in an amount from 4% to about 30% by weight of the composition, alternatively from 6% to about 27% by weight of the composition, alternatively from 8% to 24% by weight of the composition, alternatively from 10% to 20% by weight of the composition. Typically, component (a) is present in an amount that is the difference between 100% by weight of the composition and the cumulative weight % of the other components / ingredients.

[0092] Component (b)

[0093] Component (b) of the hydrosilylation (addition)-curable thermally conductive silicone rubber composition used to prepare the fabric-reinforced thermally conductive silicone rubber tubing described herein serves as a crosslinking agent and is provided in the form of an organosilicon compound having at least two, and alternatively at least three, Si—H groups per molecule. Component (b) typically contains three or more silicon-bonded hydrogen atoms, which can react with the unsaturated olefinic and / or alkynyl groups of polymer (a) to form a network structure and thereby cure the composition. When polymer (a) has more than two unsaturated groups per molecule, some or all of component (b) may alternatively have two silicon-bonded hydrogen atoms per molecule.

[0094] The molecular configuration of the organosilicon compound (b) having at least two, alternatively at least three Si—H groups per molecule is not particularly limited, and it may be linear, branched (a linear chain having some branches due to the presence of T groups), cyclic, or based on an organosilicon resin.

[0095] While there are no specific limitations on the molecular weight of component (b), to achieve good compatibility with polymer (a), the viscosity at 25°C is typically 5 to 50,000 mPa.s, depending on the Brookfield DV-III Ultra programmable rheometer with a viscosity greater than or equal to 50,000 mPa.s and the Brookfield DV 3T rheometer with a viscosity less than 50,000 mPa.s. The silicon-bonded organic group used in component (b) can be exemplified by: an alkyl group such as methyl, ethyl, propyl, n-butyl, tert-butyl, pentyl, or hexyl; an aryl group such as phenyl, tolyl, xylyl, or similar aryl groups; a 3-chloropropyl, 3,3,3-trifluoropropyl, or similar halogenated alkyl group, preferably an alkyl group having 1 to 6 carbon atoms, particularly a methyl, ethyl, or propyl group, or a phenyl group. Preferably, the silicon-bonded organic group used in component (b) is an alkyl group, alternatively a methyl, ethyl, or propyl group.

[0096] Examples of organosilicon compounds (b) having at least two, alternatively at least three Si—H groups per molecule include, but are not limited to:

[0097] (a) trimethylsiloxy-terminated methylhydrogenpolysiloxane,

[0098] (b) trimethylsiloxy-terminated polydimethylsiloxane-methylhydrogensiloxane,

[0099] (c) a dimethylsiloxane-methylhydrogensiloxane copolymer terminated with dimethylhydrogensiloxy groups,

[0100] (d) a dimethylsiloxane-methylhydrogensiloxane cyclic copolymer,

[0101] (e) (CH3)2HSiO 1 / 2 Unit, (CH3)3SiO 1 / 2 unit and SiO 4 / 2 Unit composed of copolymers and / or silicone resins,

[0102] (f) (CH3)2HSiO 1 / 2 unit and SiO 4 / 2 Unit composed of copolymers and / or silicone resins,

[0103] (g) a methylhydrogensiloxane cyclic homopolymer having 3 to 10 silicon atoms per molecule,

[0104] Alternatively, component (b) the crosslinking agent can be a filler, such as silica treated with one of the above-mentioned substances, and mixtures thereof.

[0105] In one embodiment, component (b) is selected from methylhydrogenpolysiloxane end-capped at both molecular ends with trimethylsiloxy groups; copolymers of methylhydrogensiloxane and dimethylsiloxane end-capped at both molecular ends with trimethylsiloxy groups; dimethylsiloxane end-capped at both molecular ends with dimethylhydrogensiloxy groups; copolymers of methylhydrogensiloxane and dimethylsiloxane end-capped at both molecular ends with dimethylhydrogensiloxy groups.

[0106] The crosslinker (b) is typically present in the thermally conductive silicone rubber composition such that the molar ratio of the total number of silicon-bonded hydrogen atoms in component (b) to the total number of alkenyl and / or alkynyl groups in polymer (a) and component (c) is from 0.5:1 to 20:1. When this ratio is less than 0.5:1, a well-cured composition is not obtained. When this ratio exceeds 20:1, the hardness of the cured composition tends to increase when heated. Preferably, the amount is such that the molar ratio of silicon-bonded hydrogen atoms of component (b) to alkenyl / alkynyl groups, alternatively alkenyl groups, of components (a) and (c) is in the range of 0.7:1.0 to 5.0:1.0, preferably 0.9:1.0 to 2.5:1.0, and most preferably 0.9:1.0 to 2.0:1.0.

[0107] The silicon-bonded hydrogen (Si-H) content of component (b) is determined using quantitative infrared analysis according to ASTM E168. In this context, when relying on a hydrosilylation cure process, the ratio of silicon-bonded hydrogen to alkenyl (vinyl) and / or alkynyl groups is important. Generally, this is determined by calculating the total weight percent of alkenyl groups (e.g., vinyl) [V] in the composition and the total weight percent of silicon-bonded hydrogen [H] in the composition, and assuming a molecular weight of hydrogen of 1 and a molecular weight of vinyl of 27, the molar ratio of silicon-bonded hydrogen to vinyl is 27 [H] / [V].

[0108] Typically, depending on the number of unsaturated groups in component (a) and component (c) and the number of Si—H groups in component (b), component (b) will be present in an amount from 0.1% to 10% by weight of the thermally conductive silicone rubber composition, alternatively from 0.1% to 7.5% by weight of the thermally conductive silicone rubber composition, alternatively from 0.5% to 7.5% by weight of the thermally conductive silicone rubber composition, further alternatively from 0.5% to 5% by weight of the thermally conductive silicone rubber composition.

[0109] Component (c)

[0110] Component (c) of the hydrosilylation (addition) curable thermally conductive silicone rubber composition for preparing the fabric-reinforced thermally conductive silicone rubber tube described herein is used as a treating agent for thermally conductive fillers (e.g., (e)(i) or (e)(ii)), and comprises an organopolysiloxane having a degree of polymerization between 4 and 500, and comprises

[0111] (i) at least one alkenyl group per molecule, and

[0112] (ii) at least one hydroxyl group or at least one alkoxy group, or a mixture of hydroxyl groups and alkoxy groups per molecule.

[0113] Each organopolysiloxane of component (c) therefore has a degree of polymerization between 4 and 500, ie therefore has 4 to 500 siloxy units of formula (I) as described for component (a):

[0114] R' a SiO (4-a) / 2 (I)

[0115] The subscript "a" is 0, 1, 2, or 3.

[0116] The unsaturated groups of component (c) may be located at the terminal or side chain of the polydiorganosiloxane, or, when the number is greater than one (>1), at both positions. The unsaturated groups of component (c) may be alkenyl groups or alkynyl groups as described above for component (a).

[0117] In component (c), there is also at least one hydroxyl group or at least one alkoxy group or a mixture of hydroxyl and alkoxy groups per molecule. When present, the alkoxy group may have 1 to 20 carbon atoms per group, alternatively 1 to 15 carbon atoms per group, alternatively 1 to 12 carbon atoms per group, alternatively 1 to 10 carbon atoms per group, alternatively 1 to 6 carbon atoms per group, preferably a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentoxy group, and / or a hexoxy group. The organopolysiloxane of component (c) may be linear or branched.

[0118] In component (c) of formula (I) again, in addition to the unsaturated groups described above, each R' and at least one hydroxyl group or at least one alkoxy group or mixture of hydroxyl and alkoxy groups per molecule are independently selected from the same aliphatic hydrocarbyl groups, substituted aliphatic hydrocarbyl groups, aromatic groups or substituted aromatic groups as described above for component (a).

[0119] Component (c) may be selected from polydimethylsiloxanes, alkylmethylpolysiloxanes, alkylarylpolysiloxanes or copolymers thereof (wherein reference to alkyl means any suitable alkyl group, alternatively an alkyl group having two or more carbons), provided that they have a degree of polymerization between 4 and 500 and contain

[0120] (i) at least one alkenyl group per molecule, and

[0121] (ii) at least one hydroxyl group or at least one alkoxy group, or a mixture of hydroxyl groups and alkoxy groups per molecule.

[0122] The alkenyl groups, hydroxyl groups and alkoxy groups may be pendant groups or terminal groups. In a preferred alternative, the unsaturated groups, hydroxyl groups and alkoxy groups are terminal groups.

[0123] For example, component (c) herein may be a linear or branched polydimethylsiloxane having one dimethylalkenyl end per molecule and one trialkoxy end per molecule or one hydroxydialkyl end per molecule, such as M Vi D f Si(OMe)3, which can alternatively be written as

[0124] (CH2=CH)(CH3)2SiO[(CH3)2SiO] f Si(OCH3)3

[0125] wherein f is an integer such that the degree of polymerization is 4 to 500, alternatively f is an integer such that the degree of polymerization is 4 to 250, f is an integer such that the degree of polymerization is 4 to 150, alternatively f is an integer such that the degree of polymerization is 4 to 100. An example thereof is when f is 25, i.e., M Vi D 25 Si(OMe)3, otherwise written as

[0126] (CH2=CH)(CH3)2SiO[(CH3)2SiO] 25 SiO(CH3)3

[0127] Alternative examples of component (c) may be polydimethylmethylvinylsiloxane polymers or polymethylvinylsiloxane polymers having a degree of polymerization of 4 to 500 with dialkylhydroxyl end or dialkylmethoxy end, such as the following

[0128] R 1 (CH3)2SiO[(CH3)2SiO] m [(CH2=CH)(CH3)SiO] n SiO(CH3)3R 1

[0129] where R1 is hydroxy or alkoxy, m is zero or an integer and n is an integer such that the degree of polymerization is 4 to 500, alternatively such that the degree of polymerization is 4 to 250, alternatively such that the degree of polymerization is 4 to 150, alternatively such that the degree of polymerization is 4 to 100, alternatively such that the degree of polymerization is 4 to 50, for example wherein m+n=4 to 17.

[0130] In each case, component (c) has a degree of polymerization of from 4 to 500 and comprises

[0131] (i) at least one alkenyl group per molecule, and

[0132] (ii) at least one hydroxyl group or at least one alkoxy group, or a mixture of hydroxyl groups and alkoxy groups per molecule.

[0133] A degree of polymerization of between 4 and 500 means that the viscosity at 25°C is a minimum of about 20 mPa.s and that the number average molecular weight (Mw) of the composition is at least about 300. Molecular weight values ​​can again be determined by gel permeation chromatography, but polymers at the lower end of the range, for example with a DP of about 4 to 20, can be analyzed by gas chromatography-mass spectrometry (GC-MS).

[0134] Component (c) is present in the compositions herein in an amount of 0.1% to 10% by weight, alternatively 0.1% to 5% by weight of the composition, alternatively 0.25% to 5% by weight of the composition, alternatively 0.25% to 2.5% by weight of the composition.

[0135] Component (d)

[0136] Component (d) of the heat-conducting silicone rubber composition that can be hydrosilylated (addition) cured for preparing the fabric-reinforced heat-conducting silicone rubber tube described herein is a hydrosilylation catalyst, which comprises a platinum group metal or a compound thereof or is composed of a platinum group metal or a compound thereof. These catalysts are generally selected from catalysts of platinum group metals (platinum, ruthenium, osmium, rhodium, iridium and palladium), or compounds of one or more metals in such metals. Alternatively, due to the high activity levels of these catalysts in the hydrosilylation reaction, platinum and rhodium compounds are preferred, with platinum compounds being the most preferred. In the hydrosilylation (or addition) reaction, the hydrosilylation catalyst, such as component (d) herein, catalyzes the reaction between an unsaturated group (typically an alkenyl group, for example, a vinyl group) and a Si-H group.

[0137] The hydrosilylation catalyst of component (d) may be a platinum group metal, a platinum group metal deposited on a carrier such as activated carbon, a metal oxide such as alumina or silica, silica gel or charcoal powder, or a compound or complex of a platinum group metal. Preferably, the platinum group metal is platinum.

[0138] Examples of preferred hydrosilylation catalysts for component (d) are platinum-based catalysts, such as platinum black, platinum oxide (Adams catalyst), platinum on various solid supports, chloroplatinic acid, such as hexachloroplatinic acid (Pt oxidation state IV) (Speier catalyst), chloroplatinic acid in solution in alcohols, such as 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, such as tetravinyltetramethylcyclotetrasiloxane-platinum complex (Ashby catalyst). Soluble platinum compounds that can be used include, for example, platinum-olefin complexes of the formula (PtCl2.olefin)2 and H(PtCl3.olefin), in this context preferably being used olefins having 2 to 8 carbon atoms, such as ethylene, propylene, isomers of butene and isomers of octene, or cycloalkanes having 5 to 7 carbon atoms, such as cyclopentene, cyclohexene and cycloheptene. Other soluble platinum catalysts are, for example, platinum-cyclopropane complexes of the formula (PtCl2C3H6)2, reaction products of hexachloroplatinic acid with alcohols, ethers and aldehydes or mixtures thereof, or reaction products of hexachloroplatinic acid and / or its conversion products with vinyl-containing siloxanes (e.g., methylvinylcyclotetrasiloxane) in the presence of an ethanolic solution containing sodium bicarbonate. Platinum catalysts with phosphorus, sulfur and amine ligands, for example (Ph3P)2PtCl2, and complexes of platinum with vinyl siloxanes, such as symmetrical divinyltetramethyldisiloxane, can also be used.

[0139] Thus, specific examples of suitable platinum-based catalysts for component (d) include

[0140] (i) Complexes of chloroplatinic acid with organosiloxanes containing ethylenically unsaturated hydrocarbon groups as described in US Pat. No. 3,419,593;

[0141] (ii) chloroplatinic acid in hexahydrate or anhydrous form;

[0142] (iii) a platinum-containing catalyst obtained by a process comprising the steps of reacting chloroplatinic acid with an aliphatically unsaturated organosilicon compound such as divinyltetramethyldisiloxane;

[0143] (iv) olefin-platinum-silyl complexes such as (COD)Pt(SiMeCl2)2 as described in U.S. Patent No. 6,605,734, wherein "COD" is 1,5-cyclooctadiene; and / or

[0144] (v) Karstedt catalyst, i.e., a vinyl siloxane polymer typically containing about 1% by weight

[0145] Platinum divinyltetramethyldisiloxane complexes of platinum. Solvents such as toluene and similar organic solvents have historically been used as alternatives, but the use of vinylsiloxane polymers is currently the preferred choice. These are described in US Pat. No. 3,715,334 and US Pat. No. 3,814,730. In a preferred embodiment, component (d) can be selected from coordination compounds of platinum. In one embodiment, hexachloroplatinic acid and its conversion products with vinyl-containing siloxanes, Karstedt's catalyst, and Speier's catalyst are preferred.

[0146] The catalytic amount of the hydrosilylation catalyst is typically between 0.01 ppm and 10,000 parts by weight per million (ppm) of platinum group metal, based on the weight of the composition; alternatively between 0.01 ppm and 5000 ppm; alternatively between 0.01 ppm and 3,000 ppm and alternatively between 0.01 ppm and 1,000 ppm. In a specific embodiment, the catalytic amount of the catalyst may be in the range of 0.01 ppm to 1,000 ppm, alternatively 0.01 ppm to 750 ppm, alternatively 0.01 ppm to 500 ppm, and alternatively 0.01 ppm to 100 ppm of metal, based on the weight of the composition. This range may relate only to the metal content in the catalyst or to the entirety of the catalyst as described in detail (including its ligands), but typically these ranges relate only to the metal content in the catalyst. The catalyst may be added as a single substance or as a mixture of two or more different substances. Typically, depending on the form / concentration in which the catalyst is provided (e.g., in a polymer or solvent), component (d) will be present in an amount ranging from 0.001% to 3.0% by weight of the composition, alternatively from 0.001% to 1.5% by weight of the composition, alternatively from 0.01% to 1.5% by weight of the composition, alternatively from 0.01% to 0.1.0% by weight of the thermally conductive silicone rubber composition.

[0147] Component (e)(i)

[0148] When present, component (e)(i) of the hydrosilylation (addition)-curable thermally conductive silicone rubber composition used to prepare the fabric-reinforced thermally conductive silicone rubber tubing described herein is at least one thermally conductive filler having a volume median particle size D(v,0.5) between 0.1 micrometers and 20 micrometers (μm), in an amount of 70% to 95% by weight of the composition, alternatively 80% to 95% by weight of the composition.

[0149] The volume median particle size D(v,0.5) is D 50The particle size value of a particle size distribution (or median particle size distribution) wherein 50% of the distribution is above the stated value and 50% is below the stated value. The thermally conductive filler (e)(i) may be a single thermally conductive filler or a combination of two or more thermally conductive fillers differing in at least one property such as particle shape, volume median particle size, particle size distribution and filler type. The volume median particle size D(v,0.5) values ​​herein are taken from supplier data sheets and / or measured by laser diffraction particle size analysis using a Malvern Mastersizer 2000 with a Hydro 2000MU dispersing unit. The parameters relied upon are refractive index (RI) of the particles: 1.78 / 0.1; dispersant: water (1.33); opacity: ~10%; internal stirring speed: 3000 rpm.

[0150] The samples were prepared before analysis by mixing 0.5 g filler + 25 ml water, shaking well and placing in a Hydro 2000MU dispersion unit and subjecting to internal sonication for 2 minutes.

[0151] Any suitable thermally conductive filler may be used as component (e)(i). Examples include: metals such as bismuth, lead, tin, antimony, indium, cadmium, zinc, silver, copper, nickel, aluminum, iron, and silicon;

[0152] alloys, such as alloys of one or more of bismuth, lead, tin, antimony, indium, cadmium, zinc, silver, aluminum, iron, and / or silicon; for example, Fe-Si alloys, Fe-Al alloys, Fe-Si-Al alloys, Fe-Si-Cr alloys, Fe-Ni alloys, Fe-Ni-Co alloys, Fe-Ni-Mo alloys, Fe-Co alloys, Fe-Si-Al-Cr alloys, Fe-Si-B alloys, and Fe-Si-Co-B alloys;

[0153] Ferrites, Mn-Zn ferrite, Mn-Mg-Zn ferrite, Mg-Cu-Zn ferrite, Ni-Zn ferrite, Ni-Cu-Zn ferrite and Cu-Zn ferrite;

[0154] Metal oxides, such as aluminum oxide (aluminum oxide), zinc oxide, silicon oxide, magnesium oxide, beryllium oxide, chromium oxide, and titanium oxide;

[0155] Metal hydroxides, such as magnesium hydroxide, aluminum hydroxide, barium hydroxide, and calcium hydroxide;

[0156] Metal nitrides, such as boron nitride, aluminum nitride, and silicon nitride;

[0157] Metal carbides, such as silicon carbide, including boron carbide and titanium carbide; and

[0158] Metal silicides such as magnesium silicide, titanium silicide, zirconium silicide, tantalum silicide, niobium silicide, chromium silicide, and tungsten and molybdenum silicides.

[0159] The thermally conductive filler (e)(i) may be a mixture of two or more of the above. In some embodiments, a combination of a metal filler and an inorganic filler may be used as the thermally conductive filler (e)(i), such as a combination of an aluminum filler and an aluminum oxide filler; a combination of an aluminum filler and a zinc oxide filler; or a combination of an aluminum filler, an aluminum oxide filler, and a zinc oxide filler.

[0160] Among them, aluminum oxide, aluminum hydroxide, aluminum nitride, boron nitride and mixtures thereof are preferred.

[0161] The shape of the thermally conductive filler particles (e)(i) is not particularly limited, for example, they may be powders and / or fibers, however, round or spherical particles can prevent the viscosity from increasing to an undesirable level after a high loading of the thermally conductive filler in the composition and are therefore preferred. 50 The particle size will depend on various factors, including the type of thermally conductive filler selected and the exact amount added to the curable composition, as well as the thickness of the bond line of the device in which the cured silicone-based product of the composition will be used. In some specific cases, the thermally conductive filler (e)(i) may have a volume median particle size in the range of 0.1 micrometer to 20 micrometers (μm), alternatively 0.1 micrometer to 15 micrometers, alternatively 0.1 micrometer to 12.5 micrometers as measured by laser diffraction particle size analysis. When the hydrosilylation (addition) curable thermally conductive silicone rubber composition used to prepare the fabric reinforced thermally conductive silicone rubber tubing described herein contains the thermally conductive filler (e)(i),

[0162] The composition comprises 70 wt% to 95 wt%, alternatively such as 75 wt% to 90 wt% of the thermally conductive filler (e)(i), alternatively such as 80 wt% to 90 wt% of the thermally conductive filler (e)(i).

[0163] When the thermally conductive filler in the hydrosilylation (addition) curable thermally conductive silicone rubber composition used to prepare the fabric-reinforced thermally conductive silicone rubber tubing described herein is component (e)(i), preferably no precipitated silica or fumed silica is present in the composition. In one embodiment, when at least one thermally conductive filler is component (e)(i), no precipitated silica or fumed silica is present in the composition described herein (except at trace levels).

[0164] As discussed above, in the hydrosilylation (addition)-curable thermally conductive silicone rubber composition used to prepare the fabric-reinforced thermally conductive silicone rubber tubing described herein, component (e)(i) may be replaced by a combination of components (e)(ii) and (f).

[0165] Component (e)(ii)

[0166] When present, component (e)(ii) of the hydrosilylation (addition) curable thermally conductive silicone rubber composition used to prepare the fabric reinforced thermally conductive silicone rubber tubing described herein is at least one thermally conductive filler having a volume median particle size D(v, 0.5) of greater than 20 microns to 100 microns (μm). Any suitable thermally conductive filler as determined for component (e)(i) can be used for component (e)(ii), except that the volume median particle size D(v, 0.5) is required to be greater than 20 microns to 100 microns (μm) (determined in the same manner as discussed above). Component (e)(ii) is the same as component (e)(i), except that it has a volume median particle size D(v, 0.5) of greater than 20 microns to 100 microns (μm), and therefore, the description is not repeated here. The volume median particle size and D(v, 0.5) of the thermally conductive filler are the same as those of component (e)(i). 50 The particle size distribution will also depend on various factors, including the type of thermally conductive filler selected and the exact amount added to the curable composition, and the thickness of the bond line of the device in which the cured silicone-based product of the composition will be used. In some specific cases, the thermally conductive filler (e)(ii) can have a volume median particle size in the range of 20.0 micrometers to 100 micrometers (μm), alternatively 25 micrometers to 90 micrometers, alternatively 30 micrometers to 75 micrometers, as measured by laser diffraction particle size analysis.

[0167] In combination, component (e)(ii) and component (f) are present in an amount from 70% to 95% by weight of the composition.

[0168] Component (f)

[0169] Precipitated silica, fumed silica, colloidal silica or precipitated silica, colloidal silica and A mixture of any two or more of the fumed silicas in an amount from greater than 0% to 5% by weight of the composition

[0170] As previously indicated, when the hydrosilylation (addition)-curable thermally conductive silicone rubber composition used to prepare the fabric-reinforced thermally conductive silicone rubber tubing described herein is component (e)(i), preferably no precipitated silica, fumed silica, or colloidal silica (component (f)) is present in the composition.

[0171] When the thermally conductive filler in the hydrosilylation (addition)-curable thermally conductive silicone rubber composition used to prepare the fabric-reinforced thermally conductive silicone rubber tubing described herein is component (e)(ii), component (f) comprising precipitated silica, fumed silica, colloidal silica, or a mixture of any two or more of precipitated silica, colloidal silica, and fumed silica is also present in the composition in an amount from greater than 0% to 5% by weight of the composition.

[0172] When present, the function of precipitated silica, fumed silica and / or colloidal silica is to strengthen the composition. Such silica is preferably finely divided. Precipitated silica, fumed silica and / or colloidal silica are preferred because of their relatively high surface area (typically at least 50 m 2 / g (BET method according to ISO 9277:2010)) is specifically selected; alternatively, a surface area of ​​50m2 is usually used. 2 / g to at least 450m 2 / g (according to the BET method of ISO 9277:2010), alternatively the surface area is 50m 2 / g to 300m 2 / g (BET method according to ISO 9277:2010). All these types of silica are commercially available.

[0173] Typically, the fabric-reinforced thermally conductive silicone rubber tubing described herein produced from the thermally conductive silicone rubber composition comprising at least 70 wt. % of the thermally conductive filler (e)(i) or (e)(ii) described herein (in combination with (f)) will have a high thermal conductivity of at least 0.5 W / mK as measured according to ASTM D7896 - Hot Disc Method.

[0174] The thermal conductivity of the fabric reinforced thermally conductive silicone rubber tubing will depend on the thermally conductive filler (e)(i) or (e)(ii) utilized. In the case of thermally conductive fillers (e)(i) or (e)(ii) with poor thermal conductivity, such as aluminum oxide and aluminum hydroxide, when present in an amount of 70% by weight of the composition, the thermal conductivity of the product is generally between 0.5 W / mK and 1.0 W / mK (ASTM D7896-Hot Plate Method), and therefore the composition may require up to about 85% by weight of these thermally conductive fillers for the cured silicone-based product to have a thermal conductivity of at least 2.0 W / mK (ASTM D7896-Hot Plate Method).

[0175] However, when the thermally conductive filler (e)(i) or (e)(ii) is a nitride such as aluminum nitride, aluminum nitride, and / or boron nitride, the fabric-reinforced thermally conductive silicone rubber tube from the thermally conductive silicone rubber composition described above will have a greater thermal conductivity. In this case, they can have a significantly higher thermal conductivity, for example, at least 2.0 W / mK (ASTM D7896-hot disk method).

[0176] As previously discussed, when thermally conductive filler (e)(i) is present, the thermally conductive silicone rubber composition as described herein comprises 70% to 95% by weight, alternatively, for example, 75% to 90% by weight of thermally conductive filler (e)(i). When both thermally conductive filler (e)(ii) and component (f) are present in the composition, at least 80% by weight of the composition is thermally conductive filler (e)(ii), at least 75% by weight of the composition is thermally conductive filler (e)(ii), at least 70% by weight of the composition is thermally conductive filler (e)(ii), and the cumulative amount of thermally conductive filler and reinforcing filler (when the latter is present) is a maximum of 95% by weight.

[0177] Additional optional components

[0178] Depending on its intended end use, additional optional components may be present in the hydrosilylation (addition) curable thermally conductive silicone rubber composition used to prepare the fabric-reinforced thermally conductive silicone rubber tube described herein. Examples of such optional components include cure inhibitors, hydrophobic treatment agents (excluding component (c) herein for the avoidance of doubt), compression set additives, pigments and / or colorants, and additional additives thereof such as metal deactivators, mold release agents, UV light stabilizers, fungicides, and mixtures thereof.

[0179] Optional hydrosilylation reaction inhibitor

[0180] The heat-conducting silicone rubber composition of the hydrosilylation (addition) curing for preparing the fabric-reinforced heat-conducting silicone rubber tube described herein may also include one or more optional hydrosilylation reaction inhibitors. When needed, a hydrosilylation reaction inhibitor is used to prevent or delay the hydrosilylation reaction inhibitor curing process, especially during storage. The optional hydrosilylation reaction inhibitor based on a platinum-based catalyst is well known in the art and includes hydrazine, triazole, phosphine, mercaptan, organic nitrogen compound, alkynol, methane silyl alkynol, maleate, fumarate, ethylenic or aromatic unsaturated amide, ethylenic unsaturated isocyanate, olefinic siloxane, unsaturated hydrocarbon monoester and diester, conjugated alkene-yne, hydroperoxide, nitrile and diaziridine. Alkenyl-substituted siloxanes as described in US3989667 can be used, wherein preferred cyclic methyl vinyl siloxane.

[0181] One class of known hydrosilylation reaction inhibitors is the acetylenic compounds disclosed in US Pat. No. 3,445,420. Alkynols such as 2-methyl-3-butyn-2-ol constitute a preferred class of inhibitors that will inhibit the activity of platinum-containing catalysts at 25°C. Compositions containing these inhibitors typically require heating at temperatures of 70°C or above in order to cure at an achievable rate.

[0182] Examples of alkynols and their derivatives include 1-ethynyl-1-cyclohexanol (ETCH), 2-methyl-3-butyn-2-ol, 3-butyn-1-ol, 3-butyn-2-ol, propargyl alcohol, 1-phenyl-2-propyn-1-ol, 3,5-dimethyl-1-hexyn-3-ol, 1-ethynylcyclopentanol, 3-methyl-1-pentene-4-yn-3-ol, and mixtures thereof. Alkynol derivatives may include those compounds having at least one silicon atom.

[0183] When present, the hydrosilylation inhibitor concentration can be as low as 1 mole of hydrosilylation inhibitor per mole of metal of catalyst (d) and still provide satisfactory storage stability and cure rates in some cases. In other cases, a hydrosilylation inhibitor concentration of up to 500 moles of inhibitor per mole of metal of catalyst is desired. The optimal concentration of a given hydrosilylation inhibitor in a given composition is readily determined by routine experimentation. Depending on the concentration and form of the selected hydrosilylation inhibitor provided / commercially available, when present in the composition, the inhibitor is typically present in an amount of 0.0125 wt.% to 10 wt.% of the composition.

[0184] In one embodiment, the inhibitor, when present, is selected from 1-ethynyl-1-cyclohexanol (ETCH) and / or 2-methyl-3-butyn-2-ol and is present in an amount from greater than zero to 0.1% by weight of the composition.

[0185] Hydrophobic treatment agent for treating component (f) (when present)

[0186] When component (f) is present in combination with thermally conductive filler (e)(ii) in a hydrosilylation (addition) curable thermally conductive silicone rubber composition for preparing the fabric-reinforced thermally conductive silicone rubber tube described herein, the precipitated silica, fumed silica and / or colloidal silica of component (f) are naturally hydrophilic and can therefore be treated with a treating agent to render them hydrophobic. Component (f) can be treated with component (c) together with component (e)(ii), or can be treated alone with an alternative hydrophobic treating agent. In this case, component (f) can be surface treated with any suitable hydrophobic treating agent other than component (c) disclosed in the art. For example, low molecular weight organosilicon compounds such as organosilanes, polydiorganosiloxanes or organosilazanes, for example hexaalkyldisilazane and short chain siloxane diols. Specific examples include, but are not limited to, silanol-terminated trifluoropropylmethylsiloxane, silanol-terminated vinylmethyl (ViMe) siloxane, silanol-terminated methylphenyl (MePh) siloxane, liquid hydroxydimethyl-terminated polydiorganosiloxanes containing an average of 2 to 20 repeating units of diorganosiloxane per molecule, hydroxydimethyl-terminated phenylmethylsiloxane, hexaorganodisiloxanes such as hexamethyldisiloxane, divinyltetramethyldisiloxane; hexaorganodisilazanes such as hexamethyldisilazane (HMDZ), divinyltetramethyldisilazane, and tetramethylbis(trifluoropropyl)disilazane; hydroxydimethyl-terminated polydimethylmethylvinylsiloxane, octamethylcyclotetrasiloxane, and silanes including, but not limited to, methyltrimethoxysilane, dimethyldimethoxysilane, vinyltrimethoxysilane, methyltriethoxysilane, vinyltriethoxysilane, trimethylchlorosilane, dimethyldichlorosilane, trichloromethylsilane. In one embodiment, the treating agent may be selected from silanol-terminated vinylmethyl (ViMe) siloxanes, liquid hydroxydimethyl-terminated polydiorganosiloxanes containing an average of 2 to 20 diorganosiloxane repeating units per molecule, hexaorganodisiloxanes such as hexamethyldisiloxane and divinyltetramethyldisiloxane; hexaorganodisilazanes such as hexamethyldisilazane (HMDZ) and divinyltetramethyldisilazane; and hydroxydimethyl-terminated polydimethylmethylvinylsiloxane, octamethylcyclotetrasiloxane, and silanes including but not limited to methyltriethoxysilane, dimethyldiethoxysilane, and / or vinyltriethoxysilane. A small amount of water may be added along with the silica treating agent as a processing aid.

[0187] Surface treatment of the untreated component (f) can be performed prior to introduction into the composition or in situ (i.e., by blending the components together at room temperature or higher in the presence of at least a portion of the other components of the composition herein until the filler is completely treated). If the treating agent used is component (c) described above, the reinforcing filler and the thermally conductive filler (component (e)(ii)) are treated simultaneously. If separate filler treating agents are used for component (f) and component (e)(ii), respectively, they will need to be treated separately or sequentially.

[0188] Generally, any untreated component (f) is preferably treated in situ with a treating agent in the presence of the polydiorganosiloxane polymer (a), which results in the preparation of a silicone rubber matrix material which can then be mixed with the other components.

[0189] Optional compression set additive

[0190] While compression set is not generally considered a critical property for typical thermally conductive applications such as silicone greases, silicone gels, and gap fillers, standard thermally conductive silicone rubber compositions often exhibit very high compression set due to the high loading of thermally conductive fillers in the composition to achieve thermal conductivity. As discussed elsewhere, when thermally conductive silicone rubber compositions are designed to produce high thermal conductivity, for example, of at least 1.5 W / mK (measured according to ASTM D7896 - hot plate method), the level of thermally conductive filler required often results in a significant increase in the viscosity of the pre-cured composition, resulting in compromised handling characteristics and, in addition, after curing, in poor physical properties of the cured silicone-based product. While such products may be acceptable for some applications, there is a growing need in the industry for compositions that produce cured materials having both the following properties:

[0191] (i) the required high level of thermal conductivity, and

[0192] (ii) the required level of physical properties,

[0193] Previously, one might have expected only one of these. In the past, the presence of large amounts of thermally conductive fillers in thermally conductive silicone rubber compositions significantly reduced the elasticity / resilience of the silicone rubber, but the compositions provided herein appear to overcome this problem. However, it has been determined that, if desired, the inclusion of certain compression set additives in the hydrosilylation-curable thermally conductive silicone rubber compositions used to prepare the fabric-reinforced thermally conductive silicone rubber tubing described herein has a significant improvement in compression set. Compression set is measured herein according to ASTM D395 and is the permanent deformation remaining after the force applied to it is removed. When using elastomers, this term is generally a property of interest. Compression set occurs when a material is compressed to a specific deformation at a specific temperature for a specific time. The compression set test measures the ability of a rubber to recover to its original thickness after a long period of compressive stress at a given temperature and flexure. When a rubber material is compressed over time, it loses the ability to recover to its original thickness. This loss of elasticity (memory) may reduce the ability of a resilient gasket, seal, or cushion to perform over the long term. Gaskets may undergo permanent deformation over time, which may lead to leaks; or in the case of shock-absorbing pads, may compromise the ability to protect the unit from accidental drops. The compression set results of the materials are expressed as a percentage. The lower the percentage, the better the material's ability to resist permanent deformation under a given flexure and temperature range. The compression set additive used in this article may be selected from, for example, dodecanedioic acid, bis[2-(2-hydroxybenzoyl)hydrazide], diphenyl sulfide, salicyloylaminotriazole, 1,2-bis[-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hydrazine, phthalocyanine ketone (II) and mixtures thereof, such as dodecanedioic acid, bis[2-(2-hydroxybenzoyl)hydrazide] and copper (II) phthalocyanine. When present, the compression set additive is added to the composition in an amount of 0.01% to 5% by weight of the composition, alternatively 0.01% to 2% by weight of the composition.

[0194] Optional pigments / colorants

[0195] The hydrosilylation (addition) curable thermally conductive silicone rubber composition used to prepare the fabric-reinforced thermally conductive silicone rubber tube described herein may further include one or more pigments and / or colorants. If desired, the one or more pigments and / or colorants may be added. The pigments and / or colorants may be colored, white, black, metallic, or luminescent, such as fluorescent and phosphorescent.

[0196] Suitable white pigments and / or colorants include titanium dioxide, zinc oxide, lead oxide, zinc sulfide, lithopone, zirconium oxide, and antimony oxide.

[0197] Suitable non-white inorganic pigments and / or colorants include, but are not limited to, iron oxide pigments such as goethite, lepidocrocite, hematite, maghemite, and maghemite black, yellow, brown, and red iron oxides; 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 chrome yellow, molybdenum red, and molybdenum orange; ultramarine pigments; cobalt oxide pigments; nickel antimony titanate; lead chromium; carbon black; lamp black, and metallic effect pigments such as aluminum, copper, copper oxide, bronze, stainless steel, nickel, zinc, and brass.

[0198] Suitable organic non-white pigments and / or colorants include phthalocyanine pigments such as phthalocyanine blue and phthalocyanine green; monoarylate yellows, diarylate yellows, benzimidazolone yellows, heterocyclic yellows, DAN orange, quinacridone pigments such as quinacridone magenta and quinacridone violet; organic reds including metallized and non-metallized azo reds and other azo pigments, monoazo pigments, diazo pigments, azo pigment lakes, β-naphthol pigments, naphthol AS pigments, benzimidazolone pigments, diazo condensation pigments, isoindolinone and isoindolinone pigments, polycyclic pigments, perylene and perindigo pigments, thioindigo pigments, anthrapyrimidone pigments, flavonoid pigments, anthraquinone pigments, dioxazine pigments, triarylcarbonium pigments, quinophthalone pigments, and diketopyrrolopyrrole pigments.

[0199] When present, pigments and / or colorants are present in the range of 2%, alternatively 3%, alternatively 5% by weight of the composition to 15%, alternatively 10% by weight of the composition.

[0200] Other optional additives

[0201] Other optional additives in the hydrosilylation (addition)-curable thermally conductive silicone rubber composition used to prepare the fabric-reinforced thermally conductive silicone rubber tubing described herein may include metal deactivators, i.e., fuel and oil additives used to stabilize liquids by deactivating (usually by chelation) metal ions that are introduced largely through the action of acids naturally present in fuels and acids generated in lubricants through oxidation processes with metal parts of the system, such as dodecanedioic acid, bis[2-(2-hydroxybenzoyl)hydrazide].

[0202] If desired, a pot life extending agent, such as a triazole, may be used but is not considered necessary. The thermally conductive silicone rubber composition may therefore be free of a pot life extending agent.

[0203] Examples of flame retardants include aluminum trihydrate, chlorinated paraffin, hexabromocyclododecane, triphenyl phosphate, dimethyl methylphosphonate, tris(2,3-dibromopropyl)(tris)bromide) phosphate, and mixtures or derivatives thereof.

[0204] Therefore, in one alternative, the hydrosilylation (addition) curable thermally conductive silicone rubber composition used to prepare the fabric-reinforced thermally conductive silicone rubber tube described herein comprises:

[0205] a) a polydiorganosiloxane having a degree of polymerization of at least 2,500 calculated from a number average molecular weight measured by gel permeation chromatography and at least two unsaturated groups per molecule, the unsaturated groups being selected from alkenyl groups or alkynyl groups, and comprising 4% by weight of the composition

[0206] is present in the composition in an amount from about 30% by weight, alternatively from 6% to about 27% by weight of the composition, alternatively from 8% to 24% by weight of the composition, alternatively from 10% to 20% by weight of the composition, alternatively the difference between 100% by weight and the cumulative amounts of all other ingredients present in the composition;

[0207] b) an organosilicon compound having at least two, alternatively at least three Si—H groups per molecule, component (b) is present in an amount of 0.1 wt % to 10 wt % of the hydrosilylation (addition) curable thermally conductive silicone rubber composition for preparing a textile-reinforced thermally conductive silicone rubber tube, alternatively 0.1 wt % to 7.5 wt % of the hydrosilylation (addition) curable thermally conductive silicone rubber composition, alternatively 0.5 wt % to 7.5 wt % of the hydrosilylation (addition) curable thermally conductive silicone rubber composition, further alternatively 0.5 wt % to 5 wt % of the hydrosilylation (addition) curable thermally conductive silicone rubber composition.

[0208] c) an organopolysiloxane filler treating agent having a degree of polymerization of between 4 and 500 calculated from the number average molecular weight determined by gel permeation chromatography and comprising:

[0209] (i) at least one alkenyl group per molecule, and

[0210] (ii) at least one hydroxyl group or at least one alkoxy group, or a mixture of hydroxyl groups and alkoxy groups per molecule;

[0211] in an amount of 0.1% to 10% by weight of the composition, alternatively in an amount of 0.1% to 5% by weight of the composition, alternatively in an amount of 0.25% to 5% by weight of the composition, alternatively in an amount of 0.25% to 2.5% by weight of the composition; and

[0212] d) a hydrosilylation catalyst comprising or consisting of a platinum group metal or a compound thereof, in an amount, depending on the form / concentration in which the catalyst is provided, of 0.001 wt % to 3.0 wt % of the composition, alternatively 0.001 wt % to 1.5 wt % of the composition, alternatively 0.01 wt % to 1.5 wt % of the thermally conductive silicone rubber composition,

[0213] Alternatively within the range of 0.01 wt% to 0.1.0 wt%, and

[0214] (e)(i) at least one thermally conductive filler having a volume median particle size of 0.1 micrometer to 20 micrometers (μm) as measured by laser diffraction particle size analysis, in an amount from 70% to 95% by weight of the composition, alternatively from 80% to 95% by weight of the composition; or

[0215] (e) A combination of (ii) and (f), where

[0216] (e)(ii) is at least one thermally conductive filler having a volume median particle size greater than 20 micrometers to 100 micrometers (μm) as measured by laser diffraction particle size analysis and

[0217] f) precipitated silica, fumed silica, colloidal silica, or a mixture of any two or more of precipitated silica, colloidal silica, and fumed silica in an amount from greater than 0% to 5% by weight of the composition;

[0218] wherein the combination of (e)(ii) + (f) is present in the composition in an amount of from 70 wt% to 95 wt% of the composition, alternatively from 80 wt% to 95 wt% of the composition, provided that the total wt% of the composition is 100 wt%.

[0219] The composition may also contain one or more of the above-mentioned optional additives in the amounts again indicated, provided that the total weight % of the composition is 100 weight %.

[0220] Prior to step (I) of preparing the fabric-reinforced thermally conductive silicone rubber hose described herein, the mixture of the aforementioned components (a), (b), and (d) from the hydrosilylation (addition) curable thermally conductive silicone rubber composition may begin to cure at ambient temperature or higher. Thus, if a mixture of multiple components and additives needs to be stored between mixing and final use, the composition may be stored in multiple parts. However, considering that component (a) in the hydrosilylation (addition) curable thermally conductive silicone rubber composition used to prepare the fabric-reinforced thermally conductive silicone rubber hose described herein is a high viscosity (>1000,000 mPa.s at 25°C) polymer commonly referred to in the industry as silicone rubber, it is preferred that the compositions be mixed together as a one-part composition as an aspect of the method step for preparing the aforementioned hose.

[0221] In the latter case of preparing a one-part composition, the heat-conducting silicone rubber composition that can be cured by hydrosilylation (addition) curing for preparing the heat-conducting silicone rubber tube of fabric reinforcement described herein can be prepared by combining all components together into a one-part composition. Usually, a matrix is ​​first prepared to enable in-situ treatment of heat-conducting fillers, and then the remaining ingredients can be introduced into the mixture in any suitable order. Any mixing technology and device described in the prior art can be used to complete step (I) of the method. The specific device to be used will be determined by the viscosity of the component and the final curable coating composition. Suitable mixers include but are not limited to paddle mixers, such as planetary mixers and kneader type mixers. However, when component (a) is glue, it can be preferably mixed using, for example, a double-roll grinder or a kneading mixer. It may be desirable to cool the components during mixing to avoid premature solidification of the composition.

[0222] However, such hydrosilylation (addition) curable thermally conductive silicone rubber compositions can be stored in multiple parts, typically two parts, and when the composition is not to be used immediately, the two parts are mixed together immediately before use. In this case, the two parts are typically referred to as part (A) and part (B), and are designed to keep components (b) crosslinking agent and (d) catalyst separate to avoid premature curing.

[0223] Typically, in such cases, the Part A composition will comprise components (a) polymer, (c) treating agent, (d) catalyst and a combination of (e) (i) or (e) (ii) and (f), and Part B will comprise components (a) polymer, (b) crosslinking agent, (c) treating agent and a combination of (e) (i) or (e) (ii) and (f), and inhibitor (when present). Other optional additives, when present in the composition, may be in Part A or Part B, provided that they do not adversely affect the properties of any other component (e.g., catalyst deactivation). Although it is preferred to use a one-part composition, in the case where the hydrosilylation (addition) curable thermally conductive silicone rubber composition for preparing the fabric-reinforced thermally conductive silicone rubber tubing described herein is stored in two parts, the Part A and Part B compositions are mixed together shortly before use to initiate curing of the entire composition into a silicone elastomeric material. The compositions can be designed to be mixed in any suitable weight ratio. Typically, the Part A and Part B compositions are mixed together using a two-roll mill or a kneading mixer.

[0224] The components in each of part A and / or part B can be mixed together individually, or can be introduced into the composition in a pre-prepared combined form, such as to be easy to mix the final composition. For example, component (a) and component (e) (i) or a combination of (e) (ii) and (f) can be mixed together to form a base material composition. In such cases, component (c) treating agent is usually introduced into the mixture so that the thermally conductive filler (e) can be processed in situ. Alternatively, the combination of component (e) (i) or (e) (ii) and (f) can be pre-treated with component (c), although this is not preferred. The resulting base material can be divided into two or more parts, usually part A and part B, and if necessary and when necessary, suitable additional components and additives can be added.

[0225] Once the hydrosilylation (addition) curable thermally conductive silicone rubber composition for preparing a fabric-reinforced thermally conductive silicone rubber hose is prepared in step (I) of the method, the resulting composition is introduced into a suitable extruder and extruded therefrom to form a thermally conductive silicone rubber hose (A), after which the resulting hose is cooled or allowed to cool, typically to room temperature or thereabouts. The thermally conductive silicone rubber hose (A) serves as the inner layer of the final fabric-reinforced thermally conductive silicone rubber hose product.

[0226] Any suitable extruder may be used. The extruder may be a single-screw extruder or a twin-screw extruder, and may be in the form of a horizontal extruder optionally having a vertical extrusion head. The extruder may have at least two heating tunnels, alternatively two heating tunnels. When the extruder has two heating tunnels, and the first heating tunnel is maintained at a higher temperature than the second heating tunnel, the hydrosilylation (addition) curable heat-conductive silicone rubber composition used to prepare the fabric-reinforced heat-conductive silicone rubber tube is conveyed through the first heating tunnel, and the composition is conveyed through the second heating tunnel. For example, the temperature of the first heating tunnel is maintained at a temperature of 350°C to 600°C, alternatively 350°C to 550°C, alternatively 400°C to 500°C; and the temperature of the second heating tunnel is maintained at a temperature of 150°C to 300°C, alternatively 200°C to 300°C, alternatively 200°C to 250°C.

[0227] However, the hydrosilylation (addition) curable thermally conductive silicone rubber composition used to prepare the fabric-reinforced thermally conductive silicone rubber passes through the first heating tunnel in no more than about 20 seconds, for example, 5 to 15 seconds, alternatively 5 to 10 seconds, and the composition passes through the second heating tunnel for a period of between 60 and 420 seconds, alternatively between 90 and 360 seconds, alternatively between 100 and 300 seconds.

[0228] The above requirements enable a horizontal extruder with a vertical extrusion head to control tube outer diameter (OD) and layer thickness, with the latter preferably being 0.1 mm to 10.0 mm, alternatively 0.25 mm to 7.5 mm, alternatively 0.5 mm to 5.0 mm.

[0229] Once the above step (II) is completed and the resulting tube (A) has cooled sufficiently, a fiber layer is applied to the outer surface of the tube from step (II).

[0230] As previously indicated, the fabric used to cover the tube (A) is made of a reinforcing fabric selected from glass fiber fabric, polyester fiber fabric, polyamide fiber fabric and / or polyaramid fiber fabric, or a mixture thereof. Step (III) can be carried out in any suitable manner, for example the fabric can be in the form of a sleeve that is slipped over the top of the tube A produced in step (II). Alternatively, the fibers can be woven or knitted onto the inner tube (A), and the fabric can then be wrapped around the inner tube A to form layer B.

[0231] In one embodiment, an optional priming step may be performed between steps (III) and (IV) to enhance the interaction between the reinforcing fabric and the Si tube layer. This may be achieved by applying an adhesion primer to the fabric. Any suitable adhesion promoter may be used, for example, one or more commercially available coupling agents such as alkoxysilanes, ethoxysilanes, and titanates, dissolved in an organic solvent.

[0232] After fabric layer B is applied, step (IV) is performed wherein a top layer of the hydrosilylation (addition) curable thermally conductive silicone rubber composition is extruded on top of fabric layer B using a similar method as used to prepare inner tube A.

[0233] Aside from the extrusion head, the same extruder as used in step (II) can be used for step (IV), and thus the same temperature range can be utilized if desired, but full details are not repeated here.

[0234] The layer thickness of the outer layer C can also be designed to have such a layer thickness, wherein the latter is preferably 0.1mm to 10.0mm, alternatively 0.25mm to 7.5mm, alternatively 0.5mm to 5.0mm, alternatively 0.5mm to 2.5mm, alternatively 0.5mm to 2.0mm. When necessary, the fabric-reinforced thermally conductive silicone rubber tube can be post-cured.

[0235] The post-cure will be conducted at a temperature ranging from about 120° C. to about 200° C. The post-cure step may be conducted for a period of about 1 hour to about 8 hours, as needed or desired.

[0236] The total wall thickness of the fabric-reinforced thermally conductive silicone rubber tubing produced by this method is designed to meet the actual requirements of the final application of the tubing itself. For example, if the tubing is to be used as a fabric-reinforced thermally conductive silicone rubber cooling tubing positioned next to a 24 mm (OD) charging cable in a fast-charging device for EV applications, the outer diameter of the tubing will be between 6 mm and 7 mm, with a wall thickness between 1 mm and 2 mm.

[0237] The fabric-reinforced thermally conductive silicone rubber tubing described herein can be used as a cooling device in a variety of applications, including, for example, any cable / device requiring a liquid cooling system, such as in automotive and electronic device applications, including EV super charging guns, high-power cooling cables, and any device for heat dissipation components of motor drive modules and control modules. Example

[0238] Unless otherwise specified, all viscosities are measured at 25°C. Unless otherwise specified, the viscosity of each component in the following examples was measured using a Brookfield DV-III Ultra Programmable Rheometer for viscosities greater than or equal to 50,000 mPa.s, and a Brookfield DV 3T Rheometer for viscosities less than 50,000 mPa.s. The molar ratio of SiH:vinyl for all examples and comparative examples was 1.5:1.

[0239] A series of compositions for comparative formulation examples and formulation composition examples were prepared and are described in Table 1a and Table 1b, respectively.

[0240] Table 1a: Composition of Comparative Examples FC1 to FC4 (wt%)

[0241] FC1 FC2 FC3 Organic silicone 1 20.44 15.42 12.53 Alumina 1 32.00 34.00 35.00 Alumina 2 46.22 49.24 51.13 Total alumina content 78.22 83.24 86.13 Treatment agent 1 1.00 1.00 1.00 Crosslinker 1 0.15 0.15 0.15 ETCH 0.04 0.04 0.04 Karstedt Catalyst 0.15 0.15 0.15 total 100.00 100.00 100.00

[0242] The above is also compared with FC4, which is manufactured by Dow Silicones Corporation of Midland Michigan, USA under the name XIAMETER TM RBB-2400-70 silicone rubber is sold commercially.

[0243] Table 1b: Composition of Reference Examples F.Ex.1 to F.Ex.5 (wt%)

[0244] F.Ex.1 F.Ex.2 F.Ex.3 F.Ex.4 F.Ex.5 Organic silicone 1 7.73 5.73 6.04 16.54 Silicone rubber base 1 10.00 12.00 10.00 16.04 Alumina 1 33.00 33.00 34.00 34.00 80.27 Alumina 2 47.75 47.75 48.44 48.44 Total alumina content 80.75 80.75 82.44 82.44 80.27 Treatment agent 1 1.00 1.00 1.00 1.00 1.00 Treatment agent 2 1.00 Crosslinker 1 1.00 Crosslinker 2 0.33 0.33 0.33 0.33 ETCH 0.04 0.04 0.04 0.04 0.04 Karstedt Catalyst 0.15 0.15 0.15 0.15 0.15 total 100.00 100.00 100.00 100.00 100.00

[0245] The components identified in Table 1a and Table 1b are as follows:

[0246] Silicone Gel 1 is a dimethylvinyl terminated polydimethylsiloxane having a degree of polymerization (DP) of 5840 and a William's plasticity of 150 mm / 100 according to ASTM D-926-08.

[0247] Silicone rubber base 1: 70.56 wt% silicone rubber 1 and 29.44 wt% HDK TM T30P sells fumed silica;

[0248] Alumina 1 is ALM-41-01 sold by Sumitomo Chemical Co., Japan, having a particle size between 1 μm and 2 μm (manufacturer's information).

[0249] Alumina 2 is grade ADM-40K from Denka Company Limited, the average particle size of which is spherical in form with a volume median particle size of 40 μm (manufacturer's information).

[0250] Treatment agent 1 is (CH2=CH)(CH3)2SiO[(CH3)2SiO] 25 SiO(CH3)3

[0251] Treatment 2: dimethylhydroxy terminated dimethylmethylvinylsiloxane with a DP between 4-17.

[0252] Si—H crosslinker 1 is trimethyl terminated dimethylmethylhydrogensiloxane having a viscosity of approximately 15 mPa·s at 25°C.

[0253] Si—H crosslinker 2 is trimethyl terminated dimethylmethylhydrogensiloxane, which has a viscosity of approximately 5 mPa·s at 25°C.

[0254] The Si—H / vinyl molar ratio of the comparative formulations FC1, FC2, and FC3 was 1.5:1.

[0255] ETCH is ethynylcyclohexanol.

[0256] A series of tests were conducted to evaluate the physical properties of each of the formulations Reference Examples 1 to 5 and the Comparative Example according to the ASTM International Standard test methods indicated in Table 2a and Table 2b below.

[0257] The samples for this test were prepared as follows:

[0258] The composition was prepared by first gradually charging the silicone rubber base 1 starting material (component (a)) with the thermally conductive filler and filler treatment agent into a 5L laboratory kneading mixer to prepare an intermediate base composition. The mixture was then mixed at 120°C for approximately one hour until homogeneous, continuing for one hour. The resulting base was then cooled to room temperature. After cooling, the Si-H crosslinker, Karstedt catalyst, and hydrosilylation cure inhibitor were added and mixed into the composition on a two-roll mill. The resulting composition was then compression molded using a pressurized curing apparatus at 120°C for 10 minutes, with a sample thickness of 2 mm.

[0259] Thermal conductivity testing was performed using 6 mm plaques that were cured in a pressurized apparatus at 120° C. for 20 minutes. Thermal conductivity testing was also performed on 6 mm thick plaques that had been post-cured at 200° C. for 4 hours to assess any changes in thermal conductivity properties.

[0260] Table 2a: Physical properties / performance after curing at 120°C for 10 minutes and comparative examples FC1 to FC3 and FC4 (XIAMETER TM Thermal conductivity test of RBB-2400-70 silicone rubber .

[0261] Tested characteristics FC1 FC2 FC3 FC4 Hardness (Shore A, ASTM D2240) 55 70 80 75 Tensile strength (MPa, ASTM D412) 2.92 3.44 3.87 10 Elongation at break (%, ASTM D412) 255 171 125 400 Modulus at 100% elongation (MPa, ASTM D412) 1.33 2.31 3.37 2.31 Tear strength (kN / m, ASTM D624DIE C) 9.86 8.29 9.08 27 <![CDATA[Specific gravity (g / cm 3 , ASTM D792)]]> 2.36 2.59 2.74 1.21 Thermal conductivity (W / mK, hot plate (HD)) Non-post-curing (6mm, 120℃ / 20min) 1.17 1.67 2.22 0.22 Post-curing (6mm, 200℃ / 4h) 1.18 1.63 2.18 0.22

[0262] Table 2b: Physical properties / performance after curing at 120°C for 10 minutes and thermal conductivity tests of F.Ex. 1 to 5

[0263]

[0264] The physical properties of all comparative and reference examples were found to be acceptable. In each example and comparative example, a large amount of alumina filler has been filled to achieve the desired level of thermal conductivity, so when compared to the commercial product XIAMETER TM Compared with RBB-2400-70 silicone rubber, the physical properties are significantly reduced. For the highly filled examples and comparative examples, it is found that the examples described above have better thermal conductivity and extrusion processability.

[0265] Each of the above compositions was then also tested for suitability for extrusion into, for example, pipes, which would demonstrate suitability as cooling pipes and plasticity, and the results are provided in Tables 3a and 3b.

[0266] When evaluating extrudability, samples were prepared as follows:

[0267] All ingredients of the relevant composition are mixed together on a two-roll mill to form a one-part composition. Once mixing is complete, the composition is introduced into a horizontal extruder with a vertical extrusion head, which has a first heating tunnel and a second heating tunnel. The composition is present in the first heating tunnel, which is maintained at a temperature range of 400°C to 500°C for a period of between 6 seconds and 10 seconds. It is then passed into the second heating tunnel, maintained at a temperature range of 200°C to 250°C for a period of between 100 seconds and 300 seconds, and the resulting extrudate is discharged from the extrusion head.

[0268] The various comparative and example compositions were evaluated for their suitability for use in extruded tubes.

[0269] F.Ex. 1 to 5 were found to be suitable for use in extrusion molding of cooling tubes and the like, but it was found that, given the very high proportion of thermally conductive filler (aluminum oxide) present, while the tubes could be readily prepared, those produced were not considered strong enough to confidently withstand the passage of liquid through the tube at a fluid pressure of at least 1 MPa in accordance with the Chinese National Standard Test Method GB / T5563-2013 without rupture.

[0270] However, it was determined that by providing a reinforcement in the shape of a second layer of reinforcing fibers in a composite tube as described herein, the resulting tube both meets the thermal conductivity values ​​and is capable of withstanding the passage of at least a liquid at a fluid pressure of at least 1 MPa through the tube according to the Chinese National Standard Test Method GB / T5563-2013 without rupture.

[0271] Table 3a: Comparative results of plasticity and extrusion suitability of compositions FC1 to FC.3

[0272] FC1 FC2 FC3 Plasticity (mm / 100) (ASTM D-926-08) 176 180 181 Extrusion processability Difference Difference Difference

[0273] The comparative compositions were found to have poor extrudability and also had plasticity values ​​below 200 mm / 100. The plasticity of these materials was not high enough to keep the materials consistent during extrusion. In other words, the green strength of these materials was not strong enough. These materials could not be conveyed consistently through the screw. They would break during extrusion and entrap air.

[0274] Table 3b: Plasticity results and extrusion suitability of comparative compositions F.Ex. 1 to 5

[0275]

[0276] In contrast, F.Ex. 1 to 5 all have higher plasticity results, specifically >200 mm / 100, and in fact greater than 225 mm / 100, and are considered suitable for extrusion. For the avoidance of doubt, all of F.Ex. 1 to 5 are considered suitable for use as the extrudable hydrosilylation (addition) curable thermally conductive silicone rubber compositions required for preparing the fabric reinforced thermally conductive silicone rubber tubing herein, but it is believed that fabric reinforcement as described herein is required to ensure that the prepared tubing can withstand the required fluid pressure.

[0277] Good extrusion processability was considered satisfied for samples that exhibited a consistent stable OD, a smooth surface, and no bubbles or other defects detected on the tube surface and / or in the cross section of the tube.

[0278] As evidence, an additional series of examples were produced, primarily based on the composition of F.Ex.5 as shown in Table 1b, and compared with the single-layer tube of Ex.1 and a comparative tube made from a composition identified as C.4. The method utilized is described below, and the results are shown in Table 4 below.

[0279] The process for forming the single-layer tubes in Comparative Examples C.1 and C.2 was carried out using the method described previously.

[0280] For C.3 and Ex.1 and Ex.2, produce the fabric-reinforced thermally conductive silicone rubber tubing using the following method:

[0281] The components of the composition are mixed together on a two-roll mill, with the catalyst added last. The resulting composition is introduced into a suitable horizontal extruder with a vertical extrusion head, equipped with a first heating tunnel and a second heating tunnel. An inner tube with a wall thickness of approximately 0.7 mm is extruded through the first heating tunnel, maintained at a temperature in the range of 400°C to 500°C for a period of between 6 and 10 seconds. It is then passed through a second heating tunnel, maintained at a temperature in the range of 200°C to 250°C for a period of between 100 and 300 seconds, and the resulting extrudate is discharged from the extrusion head. Once the inner tube has been allowed to cool sufficiently, a second layer of polyethylene terephthalate reinforcement fabric is knitted onto it. After the fabric layer is applied, a top layer with a wall thickness of approximately 0.5 mm is extruded on top of the knitted fabric intermediate layer using the same method as the inner tube layer.

[0282] The hydrostatic tests in Tables 4a and 4b are in accordance with the Chinese National Standard Test Method GB / T 5563-2013 for Rubber and Plastic Hoses and Hose Assemblies as previously discussed.

[0283] Table 4a: Properties / performance of comparative examples C.1 to C.3 .

[0284]

[0285] Table 4b: Properties / Performance Table of Comparative Examples 1 to 6

[0286]

[0287] As can be seen from C.1 and C.2, tubes with a wall thickness (WT) of 1.0 mm or 1.2 mm made using the composition of the Ex.1 hydrosilylation (addition)-curable thermally conductive silicone rubber composition used to prepare the fabric-reinforced thermally conductive silicone rubber tube described herein give good thermal conductivity results, but the relatively poor GB / T 5563-2013 results indicate that such tubes will potentially break during use as cooling tubes, for example, for EV fast charging systems, and are therefore not reliable enough for such purposes. In the case of C.3, a three-layer composite tube was prepared using a standard silicone rubber composition. In this case, as expected, the tube provided excellent GB / T 5563-201 results, undoubtedly aided in part by the presence of the reinforcement layer. However, this tube had very poor thermal conductivity results (almost zero). Examples 1 and 2 provide very good composite tubes with high resistance to fluid (water) pressure and high thermal conductivity results.

Claims

1. A fabric-reinforced thermally conductive organic silicone rubber tube, comprising (A) a first inner layer, the first inner layer being a thermally conductive silicone rubber tube in the form of an extruded cured product of a hydrosilylation (addition)-curable thermally conductive silicone rubber composition; (B) a second intermediate layer of a reinforcing fabric covering the tube (A), the reinforcing fabric being selected from glass fiber fabric, polyester fiber fabric, polyamide fiber fabric and / or polyaramid fiber fabric or a reinforcing fabric comprising a mixture of any two or more thereof; and (C) a third outer layer, the third outer layer being a thermally conductive silicone rubber tube in the form of an extruded cured product of a hydrosilylation (addition)-curable thermally conductive silicone rubber composition on the second intermediate layer (B); The first inner layer (A) and the third outer layer (C) are both made of a cured product of the hydrosilylation (addition) curable thermally conductive silicone rubber composition comprising the following components: a) a polydiorganosiloxane having a degree of polymerization of at least 2,500 calculated from a number average molecular weight determined by gel permeation chromatography and at least two unsaturated groups per molecule, the unsaturated groups being selected from alkenyl groups or alkynyl groups; b) an organosilicon compound having at least two, alternatively at least three Si—H groups per molecule, c) an organopolysiloxane filler treating agent having a degree of polymerization of between 4 and 500 calculated from the number average molecular weight determined by gel permeation chromatography and comprising: (i) at least one alkenyl group per molecule, and (ii) at least one hydroxyl group or at least one alkoxy group, or a mixture of hydroxyl groups and alkoxy groups per molecule; The amount thereof is 0.1% to 10% by weight of the composition; d) a hydrosilylation catalyst comprising or consisting of a platinum group metal or a compound thereof; as well as (e)(i) at least one thermally conductive filler having a volume median particle size of 0.1 to 20 micrometers (μm) as measured by laser diffraction particle size analysis, in an amount of 70 to 95 weight percent of the composition; or (e) A combination of (ii) and (f), where (e)(ii) is at least one thermally conductive filler having a volume median particle size of greater than 20 micrometers to 100 micrometers (μm) as measured by laser diffraction particle size analysis and f) precipitated silica, fumed silica, colloidal silica, or a mixture of any two or more of precipitated silica, colloidal silica, and fumed silica in an amount from greater than 0% to 5% by weight of the composition; wherein the combination of (e)(ii) + (f) is present in the composition in an amount of 70 wt% to 95 wt% of the composition, and wherein the total wt% of the composition is 100 wt%.

2. The fabric-reinforced thermally conductive silicone rubber tube according to claim 1, wherein component (a) has a degree of polymerization of at least 4,000 as determined by gel permeation chromatography.

3. A fabric-reinforced thermally conductive silicone rubber tube according to any preceding claim, wherein the tube has a thermal conductivity of at least 0.5 W / mK measured according to ASTM D7896 - Hot Disc Method, while being capable of withstanding a fluid (e.g., water) pressure greater than 1 MPa according to standard test method GB / T5563-201.

4. The fabric-reinforced thermally conductive silicone rubber tube according to any preceding claim, wherein the fabric-reinforced thermally conductive silicone rubber tube has a wall thickness of 0.50 mm to 10 mm.

5. The fabric-reinforced thermally conductive silicone rubber tube according to any preceding claim, used as a tube for a water cooling system of an electric vehicle charging cable.

6. A method for preparing a fabric-reinforced thermally conductive silicone rubber tube, the method comprising the following steps: 1) preparing a hydrosilylation (addition) curable thermally conductive silicone rubber composition comprising the following components: a) a polydiorganosiloxane having a degree of polymerization of at least 2,500 calculated from a number average molecular weight determined by gel permeation chromatography and at least two unsaturated groups per molecule, the unsaturated groups being selected from alkenyl groups or alkynyl groups; b) an organosilicon compound having at least two, alternatively at least three Si—H groups per molecule, c) an organopolysiloxane filler treating agent having a degree of polymerization of between 4 and 500 calculated from the number average molecular weight determined by gel permeation chromatography and comprising: (i) at least one alkenyl group per molecule, and (ii) at least one hydroxyl group or at least one alkoxy group, or a mixture of hydroxyl groups and alkoxy groups per molecule; The amount thereof is 0.1% to 10% by weight of the composition; d) a hydrosilylation catalyst comprising or consisting of a platinum group metal or a compound thereof; as well as (e)(i) at least one thermally conductive filler having a volume median particle size of 0.1 to 20 micrometers (μm) as measured by laser diffraction particle size analysis, in an amount of 70 to 95 weight percent of the composition; or (e) A combination of (ii) and (f), where (e)(ii) is at least one thermally conductive filler having a volume median particle size of greater than 20 micrometers to 100 micrometers (μm) as measured by laser diffraction particle size analysis and f) precipitated silica, fumed silica, colloidal silica, or a mixture of any two or more of precipitated silica, colloidal silica, and fumed silica in an amount from greater than 0 wt % to 5 wt % of the composition; wherein the combination of (e)(ii) + (f) is present in the composition in an amount from 70 to 95 wt % of the composition, and wherein the total wt % of the composition is 100 wt %; II) introducing a hydrosilylation (addition) curable thermally conductive silicone rubber composition onto an extruder, extruding the hydrosilylation (addition) curable thermally conductive silicone rubber composition from the extruder to form a thermally conductive silicone rubber tube (A) and cooling the tube; III) covering the tube produced by step (II) with a layer (B) of a reinforcing fabric selected from glass fiber fabric, polyester fiber fabric, polyamide fiber fabric and / or polyaramid fiber fabric or a reinforcing fabric comprising a mixture of any two or more thereof to form a step (III) product; IV) extruding an outer layer (C) of the hydrosilylation (addition) curable thermally conductive silicone rubber composition surrounding the product of step (III) from the extruder to form a fabric-reinforced thermally conductive silicone rubber tube. 7 . The method for preparing a fabric-reinforced thermally conductive silicone rubber tube according to claim 6 , wherein the extruder is a horizontal extruder optionally having a vertical extrusion head.

8. The method according to claim 7, wherein the extruder has two heating tunnels, and a first heating tunnel is maintained at a higher temperature than a second heating tunnel, the hydrosilylation (addition)-curable thermally conductive silicone rubber composition for preparing the fabric-reinforced thermally conductive silicone rubber tube is conveyed through the first heating tunnel, and the composition is conveyed through the second heating tunnel.

9. The method for preparing a fabric-reinforced thermally conductive silicone rubber tube according to claim 6, 7 or 8, wherein component (a) of the composition is an organic silica gel having a Williams plasticity of at least 100 mm / 100 measured according to ASTM D-926-08.

10. The method for producing a fabric-reinforced thermally conductive silicone rubber tube according to claim 6, 7, 8 or 9, wherein the layer (B) of reinforcing fabric is wound or knitted around the inner layer (A).

11. A fabric-reinforced thermally conductive organic silicone rubber tube, prepared according to any one of claims 6 to 10.

12. A water-cooling system pipe for an electric vehicle charging cable, comprising or consisting of the fabric-reinforced thermally conductive silicone rubber tube according to claim 11.

13. Use of a thermally conductive organosilicon rubber composition, the thermally conductive organosilicon rubber composition comprising the following components: a) a polydiorganosiloxane having a degree of polymerization of at least 2,500 calculated from a number average molecular weight determined by gel permeation chromatography and at least two unsaturated groups per molecule, the unsaturated groups being selected from alkenyl groups or alkynyl groups; b) an organosilicon compound having at least two, alternatively at least three Si—H groups per molecule, c) an organopolysiloxane filler treating agent having a degree of polymerization of between 4 and 500 calculated from the number average molecular weight determined by gel permeation chromatography and comprising: (i) at least one alkenyl group per molecule, and (ii) at least one hydroxyl group or at least one alkoxy group, or a mixture of hydroxyl groups and alkoxy groups per molecule; an amount ranging from 0.1% to 10% by weight of the composition; and d) a hydrosilylation catalyst comprising or consisting of a platinum group metal or a compound thereof; as well as (e)(i) at least one thermally conductive filler having a volume median particle size of 0.1 to 20 micrometers (μm) as measured by laser diffraction particle size analysis, in an amount of 70 to 90 weight percent of the composition; or (e) A combination of (ii) and (f), where (e)(ii) is at least one thermally conductive filler having a volume median particle size of greater than 20 micrometers to 100 micrometers (μm) as measured by laser diffraction particle size analysis and f) precipitated silica, fumed silica, colloidal silica, or a mixture of any two or more of precipitated silica, colloidal silica, and fumed silica in an amount from greater than 0% to 5% by weight of the composition; wherein the combination of (e)(ii) + (f) is present in the composition in an amount from 70% to 90% by weight of the composition, and wherein the total wt% of the composition is 100% by weight; In the manufacture of a fabric-reinforced thermally conductive organic silicone rubber tube, the fabric-reinforced thermally conductive organic silicone rubber tube comprises (A) a first inner layer, the first inner layer being a thermally conductive silicone rubber tube in the form of an extruded cured product of the hydrosilylation (addition)-curable thermally conductive silicone rubber composition; (B) a second intermediate layer of a reinforcing fabric covering the tube (A), the reinforcing fabric being selected from glass fiber fabric, polyester fiber fabric, polyamide fiber fabric and / or polyaramid fiber fabric or a reinforcing fabric comprising a mixture of any two or more thereof; and (C) a third outer layer which is a thermally conductive silicone rubber tube in the form of an extruded cured product of the hydrosilylation (addition)-curable thermally conductive silicone rubber composition on the second intermediate layer (B).

14. Use of the fabric-reinforced thermally conductive organic silicone rubber tube according to any one of claims 1 to 5, wherein the fabric-reinforced thermally conductive organic silicone rubber tube is used in a cable and / or equipment liquid cooling system.

15. Use of the fabric-reinforced thermally conductive silicone rubber tube according to claim 14, wherein the cable and / or device liquid cooling system is in or used for an electric vehicle charging cable device.

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