Applications of thermally conductive silicone rubber

Abstract

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

Description

[Technical Field]

[0001] This disclosure relates to a fabric-reinforced thermally conductive silicone rubber tube suitable for liquid (e.g., water) cooling systems. The tube preferably has a thermal conductivity of at least 0.5 watts / meter Kelvin (W / mK) while being able to withstand fluid (e.g., water) pressures exceeding 1 MPa. This disclosure also relates to a method for manufacturing the fabric-reinforced thermally conductive silicone rubber tube, and extends to the use of such a tube. [Background technology]

[0002] Cured silicone products containing organosiloxane elastomers are desirable for a variety of end applications, including those in the electronics field and other forms of electrical applications, due to their properties. Compositions that produce cured silicone products can be used, for example, to coat and encapsulate solid-state electronic devices such as time transistors and integrated circuits, as well as circuit boards on which these devices are often mounted, to protect them from contact with moisture, corrosive substances, and other impurities present in the environment in which these devices operate. However, while organosiloxane compositions and the resulting cured silicone products effectively protect solid devices from materials that could adversely affect their operation, they typically lack the thermal conductivity necessary to dissipate the large amounts of heat generated during such use.

[0003] One way to increase heat dissipation is to increase the thermal conductivity of materials used to coat or encapsulate solid devices by adding thermally conductive fillers (sometimes called thermally conductive fillers) to the coating or encapsulation material, such as metal powders like silver, nickel, and copper, and carbonaceous powders like carbon black, graphite powder, and / or carbon fibers. However, such compositions may suffer from various problems, particularly those resulting from the high levels of such fillers required to produce high thermal conductivity, for example, at least 0.5 W / mK (measured according to the ASTM D7896-hot disk method). Such high thermal conductivity is achieved by increasing the amount of thermally conductive filler in each composition, but if such fillers are present in amounts exceeding about 70 or 75 wt.% of the composition, a pre-cured composition with significantly increased viscosity is generally obtained, which impairs handling properties and, in addition, results in a cured silicone product with poor physical properties during curing. This is because most thermally conductive fillers do not provide reinforcement; that is, their addition does not improve the mechanical properties of the cured silicone product. While such cured silicone products may be acceptable in some applications, in industry, compositions for producing cured materials are considered unacceptable. (i) a desired high level of thermal conductivity, and (ii) Required level of physical properties It has both, There is a growing demand for compositions in which either one or the other can be predicted in advance. Solutions for (i) have been identified, but at the expense of suitable physical properties. For example, the high viscosity of pre-cured compositions due to the level of thermally conductive fillers present can be avoided by diluting the composition with non-reactive silicone or organic solvents, but this has been found to cause compatibility problems due to the diluent seeping out of the cured silicone product over time, and furthermore, such products have historically not met the customer's requirements regarding physical properties. Similarly, the physical properties of cured materials with such high levels of thermally conductive unreinforced fillers, e.g., tensile strength and elasticity, are relatively inferior and / or inconsistent compared to silicone elastomers containing optimized amounts of reinforcing fillers, etc., and as a result their availability is limited on the grounds that they do not have such physical properties, and such poor performance can cause them to break, as it limits the ability of cured silicone materials to function over long periods in many preferred applications of such materials, e.g., as gaskets, sealants, or impact insulation pads.

[0004] International application PCT / CN2022 / 114896 provides a high-consistency silicone rubber (HCR) composition comprising 80–95% by weight of a thermally conductive filler having a median volume particle size of 0.1–100 micrometers (μm) as measured by laser diffraction particle size analysis, typically 85–90% by weight of alumina (also known as aluminum hydroxide) of the composition. Such compositions have been found to be particularly suitable for molding thermally conductive silicone rubber parts using compression molding processes. However, it has been found that, generally, the compositions are too soft and / or have too low a William plasticity to form consistently acceptable extruded parts, such as tubes (and / or pipes) for liquid cooling systems used in fast-charging devices for electric vehicles, and are therefore unsuitable for extrusion applications.

[0005] 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. Three of the biggest problems that remain an issue for EV drivers and prevent the use of EV vehicles for long-distance travel are: (i) Lack of charging infrastructure, (ii) The distance that can be traveled before recharging is required, (iii) Time required for recharging That is the case.

[0006] While various methods exist for recharging EV batteries, the development of the aforementioned "fast charging" technology is becoming increasingly important as the speed at which vehicles are charged increases. However, recharging generates a significant amount of heat, which leads to the problem of how to remove the heat generated within the charging cable from the high voltage and / or current used. The solution was to use a liquid cooling system designed to cool the charging device and cable using a cryogenic liquid that passes through liquid cooling tubes. The cooling tubes are positioned adjacent to the charging wires, and the charging cable can be cooled and / or the fast charging device can be kept at a safe temperature by a cryogenic liquid, such as water, flowing through the cooling tubes, and the heat generated is designed to be transferred through the tube walls to the coolant. Given the heat generated, the coolant, such as water, is typically transported through the tube at high pressure (e.g., over 1 MPa), so the tubes must be structurally robust enough to transfer the generated heat through the tube walls to the coolant and to avoid damage to the tubes due to the fluid pressure of the coolant passing through them. However, commercially available materials used to form such tubes, such as cross-linked polyolefins (XLPO) for cooling tubes, are not suitable for long-term durability and suitability at high temperatures. This is because tubes made from XLPO are much harder and therefore much less flexible than those made from silicone elastomers. Furthermore, XLPO products such as tubes are not considered to meet the heat resistance requirements of silicone elastomers at temperatures exceeding 150°C for long-term use. [Overview of the Initiative]

[0007] This specification describes a thermally conductive silicone rubber tube reinforced with a fabric, (A) A first inner layer which is 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 of reinforcing fabric covering the tube (A), comprising a reinforcing fabric selected from glass fiber fabric, polyester fiber fabric, polyamide fiber fabric, and / or polyaramid fiber fabric, or any two or more mixtures thereof, (C) comprising a third outer layer which is a thermally conductive silicone rubber tube in the form of an extruded curing product of a hydrosilylated (addition) curable thermally conductive silicone rubber composition on a second intermediate layer (B), The first inner layer (A) and the third outer layer (C) both consist of the following components: a) A polydiorganosiloxane having a degree of polymerization of at least 2,500 calculated from the number-average molecular weight determined by gel permeation chromatography and at least two unsaturated groups per molecule, wherein the unsaturated groups are selected from alkenyl groups or alkynyl groups, b) An organosilicon compound having at least two or at least three Si-H groups per molecule, c) An organopolysiloxane packing agent having a degree of polymerization of 4 to 500, calculated from the number average molecular weight determined by gel permeation chromatography, (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 a hydroxyl group and an alkoxy group per molecule The composition contains an organopolysiloxane filler treatment agent in an amount of 0.1 to 10% by weight, d) A hydrosilylation catalyst comprising or consisting of platinum group metals or compounds thereof, (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% by weight of the composition, or in an amount of 80 to 95% by weight of the composition, (e)(ii) and (f) are combinations, (e)(ii) is at least one thermally conductive filler having a volume median particle size of more than 20 to 100 micrometers (μm) as measured by laser diffraction particle size analysis, f) is any combination of precipitated silica, fumed silica, colloidal silica, or any two or more mixtures of precipitated silica, colloidal silica, and fumed silica in an amount greater than 0 to 5% by weight of the composition. It is made from the curing product of a hydrosilylated (addition) curable thermal conductive silicone rubber composition containing, A fabric-reinforced thermally conductive silicone rubber tube is provided, wherein the combination of (e)(ii)+(f) is present in the composition in an amount of 70-95% by weight, or in an amount of 80-95% by weight, and the total weight of the composition is 100% by weight.

[0008] Furthermore, this specification provides a method for preparing a thermally conductive silicone rubber tube reinforced with a fabric, I) The following ingredients: a) A polydiorganosiloxane having a degree of polymerization of at least 2,500 calculated from the number-average molecular weight determined by gel permeation chromatography and at least two unsaturated groups per molecule, wherein the unsaturated groups are selected from alkenyl groups or alkynyl groups, b) An organosilicon compound having at least two or at least three Si-H groups per molecule, c) An organopolysiloxane packing agent having a degree of polymerization of 4 to 500, calculated from the number average molecular weight determined by gel permeation chromatography, (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 a hydroxyl group and an alkoxy group per molecule The composition contains an organopolysiloxane filler treatment agent in an amount of 0.1 to 10% by weight, d) A hydrosilylation catalyst comprising or consisting of platinum group metals or compounds thereof, (e)(i) At least one thermally conductive filler having a volume median particle size of 0.1 to 20 micrometers (μm) measured by laser diffraction particle size analysis, in an amount of 70 to 95% by weight of the composition, or in an amount of 80 to 95% by weight of the composition, or (e)(ii) A combination of (e)(ii) and (f), (e)(ii) is at least one thermally conductive filler having a volume median particle size of greater than 20 to 100 micrometers (μm) measured by laser diffraction particle size analysis, f) is any of a combination of fumed silica, precipitated silica, colloidal silica, or a mixture of any two or more of precipitated silica, colloidal silica, and fumed silica, in an amount of greater than 0 to 5% by weight of the composition, A process for preparing a hydrosilylation (addition) curable thermally conductive silicone rubber composition comprising (e)(ii)+(f) is present in the composition in an amount of 70 to 95% by weight of the composition, or in an amount of 80 to 95% by weight of the composition, and the total weight percentage of the composition is 100% by weight, II) Introducing the 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, III) Covering the tube obtained from step (II) with a reinforcing fabric layer (B) selected from a glass fiber fabric, a polyester fiber fabric, a polyamide fiber fabric, and / or a polyaramid fiber fabric, or a reinforcing fabric containing a mixture of any two or more thereof to form the product of step (III), IV) Extruding an outer layer (C) of the hydrosilylation (addition) curable thermally conductive silicone rubber composition around the product of step (III) from an extruder to form a thermally conductive silicone rubber tube reinforced with a fabric, and a method is also provided.

[0009] This specification also provides a thermally conductive silicone rubber tube reinforced with a fabric, which is manufactured according to the method described above.

[0010] Use of a thermally conductive silicone rubber composition, wherein the composition comprises the following components: a) A polydiorganosiloxane having a degree of polymerization of at least 2,500 calculated from the number-average molecular weight determined by gel permeation chromatography and at least two unsaturated groups per molecule, wherein the unsaturated groups are selected from alkenyl groups or alkynyl groups, b) An organosilicon compound having at least two or at least three Si-H groups per molecule, c) An organopolysiloxane packing agent having a degree of polymerization of 4 to 500, calculated from the number average molecular weight determined by gel permeation chromatography, (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 a hydroxyl group and an alkoxy group per molecule The composition contains an organopolysiloxane filler treatment agent in an amount of 0.1 to 10% by weight, d) A hydrosilylation catalyst comprising or consisting of platinum group metals or compounds thereof, (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% by weight of the composition, or in an amount of 80 to 95% by weight of the composition, (e)(ii) and (f) are combinations, (e)(ii) is at least one thermally conductive filler having a volume median particle size of more than 20 to 100 micrometers (μm) as measured by laser diffraction particle size analysis, f) comprises, in an amount of more than 0 to 5% by weight of the composition, any combination of precipitated silica, fumed silica, colloidal silica, or any two or more mixtures of precipitated silica, colloidal silica, and fumed silica, The combination of (e)(ii)+(f) is present in the composition in an amount of 70-95% by weight, or 80-95% by weight, and the total weight of the composition is 100% by weight. Use in the manufacture of thermally conductive silicone rubber tubing reinforced with the following fabrics is provided: (A) A first inner layer which is a thermally conductive silicone rubber tube in the form of an extruded cured product of the hydrosilylated (addition) curable thermally conductive silicone rubber composition, (B) A second intermediate layer of reinforcing fabric covering the tube (A), selected from glass fiber fabric, polyester fiber fabric, polyamide fiber fabric, and / or polyaramid fiber fabric, or a mixture of any two or more of these, and (C) A third outer layer on the second intermediate layer (B), which is a thermally conductive silicone rubber tube in the form of an extruded curing product of the hydrosilylated (addition) curable thermally conductive silicone rubber composition. [Modes for carrying out the invention]

[0011] The fabric-reinforced thermally conductive silicone rubber tubing described herein may have a circular, rectangular, i.e., square, or elliptical cross-section, depending on the desired end application, but typically has a circular cross-section which can be any preferred size having an inner diameter (ID) of 1.0 to 20.0 mm, or 2 mm to 15 mm, or 2 mm to 10 mm, or 2 mm to 8 mm, or 2 mm to 6 mm.

[0012] The tube may have any suitable wall thickness (WT) that depends on the thickness of its three layers, and an outer diameter (OD) that is the sum of ID + 2WT.

[0013] A woven thermal conductive silicone rubber tube must be strong enough to withstand the (fluid) pressure exerted on the tube by a liquid, such as water, passing through its hollow interior during use; that is, a woven thermal conductive silicone rubber tube must not be subjected to fluid pressure (i.e., water pressure) exceeding the "burst pressure" that would cause the tube to rupture. Typically, for example, when using the tubes specified herein to improve the safety of an EV charging cable water cooling system, such a woven thermal conductive silicone rubber tube must be sufficiently flexible for use, but on the other hand, it must be able to withstand fluid pressures exceeding 1.0 MPa, such as water pressure, according to the Chinese National Standard Test Method GB / T5563-2013. However, given that the tubes specified herein are thermal conductive silicone rubber tubes, an additional requirement exists in that it is important to ensure that the tubes have sufficient thermal conductivity for the purpose when using the tubes specified herein in an EV charging cable water cooling system, and such a woven thermal conductive silicone rubber tube must also exceed a thermal conductivity of at least 0.5 W / mK. Typically, a thermally conductive silicone rubber tube reinforced with the fabric described herein, obtained from a thermally conductive silicone rubber composition comprising at least 70% by weight of the thermally conductive filler described herein (e)(i) or (e)(ii) (in combination with (f)), has a high thermal conductivity of at least 0.5 W / mK, as measured according to the ASTM D7896-hot disk method.

[0014] Furthermore, such fabric-reinforced thermal conductive silicone rubber tubing may have a wall thickness (WT) of 0.5 to 10.0 mm when used as an EV charging cable water cooling system tubing for housing in a standard-sized EV charging cable as part of a water cooling system. For example, the first inner layer (A) of the fabric-reinforced thermal conductive silicone rubber tubing may have a wall thickness of 0.25 to 7.5 mm or 0.50 to 5.0 mm, and the third outer layer (C) of the fabric-reinforced thermal conductive silicone rubber tubing may have a wall thickness of 0.25 to 7.5 mm or 0.50 to 5.0 mm. As an example of charging, in one embodiment, when the tubing described herein is used as a cooling tubing for a 24 mm (OD) EV charging cable water cooling system, the first inner layer (A) may have a wall thickness of 0.6 to 0.8 mm, and the third outer layer (C) may have a wall thickness of 0.4 to 0.6 mm.

[0015] Tubes prepared by single-layer extrusion of the hydrosilylated (addition) curable thermally conductive silicone rubber compositions described herein have been found to be sufficiently flexible and sufficiently strong to be extruded to form single-layer tubes having, for example, a WT of 1-2 mm. However, such tubes in this form struggled to withstand fluid pressures exceeding 1.0 MPa, for example, hydrostatic pressure, according to the Chinese National Standard Test Method GB / T5563-2013, when water is introduced through the tube during a hydrostatic pressure test.

[0016] Surprisingly, this problem was overcome by the tube described herein by replacing the single-layer tube with a thermally conductive silicone rubber tube reinforced with a fabric prepared using the method described herein.

[0017] The woven layer B provides additional strength to the resulting cured woven fabric-reinforced thermally conductive silicone rubber tube. The reinforcing fabric used in the intermediate layer B may include any suitable woven fabric or combination of woven fabrics. The woven layer may include one or more suitable synthetic fibers, such as glass fiber woven fabrics, polyester fiber woven fabrics such as polyethylene terephthalate, polyamide fiber woven fabrics, and / or polyaramid fiber woven fabrics, or any other suitable reinforcing fabrics including two or more of these. The woven layer B may be provided and utilized in any suitable form. For example, it may be provided in the form of any suitable woven, nonwoven, or knitted fabric. The woven fabric is used to cover the inner layer A in any suitable way, for example, this may include wrapping, or braiding, or any other suitable method, or, if desired, a combination of two or more processes. An example of an optional choice is preferably any suitable net size, such as 14×14 mesh, 10×10 mesh, 8×8 mesh, or 5×5 mesh, i.e., using the number of grids per inch (2.54 cm) in the warp and weft threads, which is wrapped around or woven around the inner tube A.

[0018] Such fabric-reinforced thermal conductive silicone rubber tubing has been found to achieve and maintain all of the necessary parameters described above, and therefore, said fabric-reinforced thermal conductive silicone rubber tubing is considered suitable as cooling tubing to be placed alongside charging wires in fast charging devices for EV applications. These have sufficient strength to withstand higher fluid pressures of over 1.0 MPa when cold water is introduced through the tubing during a hydrostatic test in accordance with the Chinese National Standard Test Method GB / T5563-2013 for rubber and plastic hoses and hose assemblies for cooling EV charging cables. This is highly beneficial considering that currently available materials such as cross-linked polyolefins used for cooling tubing appear to have questionable long-term durability and suitability under high-temperature conditions. The fabric-reinforced thermal conductive silicone rubber tubing described herein and produced by the process described herein has improved parameters with good flexibility and sufficient mechanical strength, thereby making it a potentially better option in terms of heat resistance for cooling tubing.

[0019] The fabric-reinforced thermal conductive silicone rubber tubes described herein and produced by the methods herein utilize two layers of thermal conductive silicone rubber produced by extruding and curing a hydrosilylated (addition) curable thermal conductive silicone rubber composition containing the following components:

[0020] Ingredient (a) Component (a) of the hydrosilylated (addition) curable thermal conductive silicone rubber composition used in the preparation of the fabric-reinforced thermal conductive silicone rubber tube described herein is a polydiorganosiloxane having at least 2,500 degrees of polymerization and at least two unsaturated groups per molecule, wherein the unsaturated groups are selected from alkenyl groups and / or alkynyl groups.

[0021] Therefore, each polydiorganosiloxane of component (a) has a degree of polymerization of at least 2,500, or at least 3,500, or at least 4,000, that is, it has at least 2,500, or at least 3,500, or at least 4,000 siloxy units of formula (I). R' a SiO (4-a) / 2 (I)

[0022] The subscript "a" is 0, 1, 2, or 3.

[0023] Siloxy units are sometimes denoted by abbreviated nomenclature, i.e., -"M", "D", "T", and "Q", when R' is, for example, an independently selected substituted or unsubstituted hydrocarbyl group having 1 to 18 carbon atoms; or an alkyl group, typically a methyl group (further instruction on silicone nomenclature can be found in Walter Noll, Chemistry and Technology of Silicones, dated 1962, Chapter I, pages 1-9). The M unit is a siloxy unit in the formula a=3, i.e., R'3SiO 1 / 2 This corresponds to the D unit, which is the siloxy unit where a=2 in the formula, i.e., R'2SiO 2 / 2 This corresponds to the siloxy unit where a=1 in the formula, i.e., R'1SiO 3 / 2 This corresponds to the siloxy unit where a=0 in the formula, i.e., SiO 4 / 2 This corresponds to the polydiorganosiloxane, such as polyorganosiloxane, component (a), is substantially linear, but may contain a certain proportion of branching due to the presence of T units (as described above) within the molecule, and therefore the average value of a in structure (I) is approximately 2.

[0024] The unsaturated group of component (a) may be located at either the terminal or pendant position of the polydiorganosiloxane, or both. The unsaturated group of component (a) may be an alkenyl group or an alkynyl group, as described above. Each alkenyl group, if present, may contain, for example, 2 to 30, 2 to 24, 2 to 20, 2 to 12, 2 to 10, or 2 to 6 carbon atoms. If present, alkenyl groups may be exemplified by, but are not limited to, vinyl, allyl, methallyl, propenyl, hexenyl, and cyclohexenyl groups. Each alkynyl group, if present, may have, 2 to 30, alternatively 2 to 24, alternatively 2 to 20, alternatively 2 to 12, alternatively 2 to 10, or alternatively 2 to 6 carbon atoms. Examples of alkynyl groups may be exemplified by, but are not limited to, ethynyl, propynyl, and butynyl groups. Preferred examples of the unsaturated group of component (a) include vinyl, isopropenyl, allyl, and 5-hexenyl.

[0025] In formula (I), each R' other than the unsaturated group is an independently selected substituted or unsubstituted hydrocarbyl group having 1 to 18 carbon atoms. These can be individually selected from aliphatic hydrocarbyl groups, substituted aliphatic hydrocarbyl groups, aromatic groups, or substituted aromatic groups. Each aliphatic hydrocarbyl group can be exemplified, but is not limited to, alkyl groups having 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, or cycloalkyl groups such as cyclohexyl. Specific examples of alkyl groups include methyl, ethyl, propyl, pentyl, octyl, undecyl, and octadecyl groups, with methyl and ethyl groups being alternatives. The substituted aliphatic hydrocarbyl group is preferably a non-halogenated substituted alkyl group.

[0026] Aliphatic non-halogenated organyl groups are exemplified by, but are not limited to, the above-mentioned alkyl groups having substituents such as amide groups and imide groups, polyoxyalkylene groups, carbonyl groups, alkoxy groups, and oxygen-containing groups such as hydroxyl groups. Further examples of organyl groups 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 having the above substituents.

[0027] Component (a) may be selected from, for example, polydimethylsiloxane, alkylmethylpolysiloxane, alkylarylpolysiloxane, or copolymers thereof (where alkyl refers to any suitable alkyl group or an alkyl group having two or more carbon atoms), provided that each polymer contains at least two unsaturated groups, typically the alkenyl groups described above, and has a degree of polymerization of at least 2,500. They may be terminated, for example, with trialkyl groups, alkenyl dialkyl groups, or alkynyl dialkyl groups, or with any other suitable combination of terminal groups, as long as each polymer contains the required at least two unsaturated groups and a degree of polymerization of at least 2,500 per molecule.

[0028] Therefore, component (a) could be, for example, the following: Dialkylalkenyl-terminated polydimethylsiloxanes, for example, dimethylvinyl-terminated polydimethylsiloxanes; dialkylalkenyl-terminated dimethylmethylphenylsiloxanes, for example, dimethylvinyl-terminated dimethylmethylphenylsiloxanes; trialkyl-terminated dimethylmethylvinylpolysiloxanes; dialkylvinyl-terminated dimethylmethylvinylpolysiloxane copolymers; dialkylvinyl-terminated methylphenylpolysiloxanes; dialkylalkenyl-terminated methylvinylmethylphenylsiloxanes; dialkylalkenyl-terminated methylvinyldiphenylsiloxanes; dialkylalkenyl-terminated methylvinylmethylphenyldimethylsiloxanes; trimethyl-terminated methylvinylmethylphenylsiloxanes; or trimethyl-terminated methylvinylmethylphenyldimethylsiloxanes.

[0029] In all cases, component (a) has a degree of polymerization (DP) of at least 2,500, or at least 3,500, or at least 4,000. Polydiorganosiloxane polymers of this magnitude have very high viscosity (at least 1,000,000 mPa.s at 25°C, often several million mPa.s at 25°C) and high molecular weight, and as a result, having a high DP of, for example, at least 2,500, given that the degree of polymerization (DP) is calculated from the number-average molecular weight of the polymer, they are commonly referred to in the industry as polydiorganosiloxane gum, siloxane gum, or silicone gum (hereinafter referred to as silicone gum). Because measuring the viscosity of high-viscosity polymers such as silicone gum is difficult, gums tend to be defined using Williams plasticity values, as opposed to viscosity. If component (a) is silicone gum, the gum has a Williams plasticity of at least 30 mm / 100 as measured according to ASTM D-926-08, or at least 50 mm / 100 as measured according to ASTM D-926-08, or at least 100 mm / 100 as measured according to ASTM D-926-08. Typically, silicone gum has a Williams plasticity of about 100 mm / 100 to 300 mm / 100 as measured according to ASTM D-926-08, although some may have higher values.

[0030] The number-average and weight-average molecular weights of such polymers are typically determined by gel permeation chromatography using a polystyrene standard. In this disclosure, the number-average and weight-average molecular weights of the silicone gum used as component (a) herein were determined using a Waters 2695 Separations Module with a vacuum degasser and a Waters 2414 refractive index detector (Waters Corporation, MA, USA). The analysis was performed using certified grade toluene flowing at 1.0 mL / min as the eluent. Data collection and analysis were performed using Waters Empower GPC software.

[0031] The degree of polymerization of the polymer was approximately the number-average molecular weight of the polymer divided by 74 (the molecular weight of one component (I) mentioned above).

[0032] Typically, the alkenyl and / or alkynyl content of the polymer, e.g., vinyl content, is 0.01 to 3% by weight of component (a) for each polydiorganosiloxane containing at least two silicon-bonded alkenyl groups per molecule, or 0.01 to 2.5% by weight of component (a), or 0.001 to 2.0% by weight of component (a), or 0.01 to 1.5% by weight of each polydiorganosiloxane containing at least two unsaturated groups per molecule, where the unsaturated groups are selected from alkenyl or alkynyl groups per molecule of component (a). The alkenyl / alkynyl content of component (a) is determined using quantitative infrared analysis according to ASTM E168.

[0033] Component (a) may be present in the composition in amounts of 4% to about 30% by weight, or about 6% to 27% by weight, or 8% to 24% by weight, or 10% to 20% by weight. Typically, component (a) is present in an amount that is the difference between 100% by weight and the cumulative weight percentage of the other components / constituents of the composition.

[0034] Ingredient (b) Component (b) of the hydrosilylated (addition) curable thermal conductive silicone rubber composition used in the preparation of the fabric-reinforced thermal conductive silicone rubber tubing described herein functions as a crosslinking agent and is provided in the form of an organosilicon compound having at least two or at least three Si-H groups per molecule. Component (b) typically contains three or more silicon-bonded hydrogen atoms such that hydrogen atoms can react with the unsaturated alkenyl and / or alkynyl groups of polymer (a) to form a network structure with them, thereby curing the composition. Alternatively, if polymer (a) has more than two unsaturated groups per molecule, some or all of component (b) may have two silicon-bonded hydrogen atoms per molecule.

[0035] The molecular structure of organosilicon compounds (b) having at least two or at least three terminal-Si-H groups per molecule is not particularly limited and may be linear, branched (linear with several branches through the presence of T groups), cyclic, or silicone resin-based.

[0036] The molecular weight of component (b) is not particularly limited, but the viscosity is typically 5 to 50,000 mPa.s at 25°C, depending on either the Brookfield DV-III Ultra Programmable Rheometer for viscosities of 50,000 mPa.s or more, and the Brookfield DV 3T Rheometer for viscosities less than 50,000 mPa.s, in order to obtain good miscibility with polymer (a). The silicon-bonded organic group used in component (b) may be exemplified by alkyl groups such as methyl, ethyl, propyl, n-butyl, t-butyl, pentyl, and hexyl; aryl groups such as phenyl, tolyl, xylyl, or similar aryl groups; and 3-chloropropyl, 3,3,3-trifluoropropyl, or similar halogenated alkyl groups, preferably alkyl groups having 1 to 6 carbon atoms, particularly methyl, ethyl, or propyl groups, or phenyl groups. Preferably, the silicon-bonded organic group used in component (b) is an alkyl group, or a methyl, ethyl, or propyl group.

[0037] Examples of organosilicon compounds (b) having at least two or at least three Si-H groups per molecule include, but are not limited to, the following: (a) Trimethylsiloxy-terminated methylhydrogenpolysiloxane, (b) Trimethylsiloxy-terminated polydimethylsiloxane-methylhydrogensiloxane, (c) Dimethylhydrogensiloxy-terminated dimethylsiloxane-methylhydrogensiloxane copolymer, (d) Dimethylsiloxane-methylhydrogensiloxane cyclic copolymer, (e)(CH3)2HSiO 1 / 2Unit, (CH3)3SiO 1 / 2 Unit, and SiO 4 / 2 A copolymer and / or a silicone resin composed of units, (f)(CH3)2HSiO 1 / 2 Unit and SiO 4 / 2 A copolymer and / or a silicone resin composed of units, (g) A methylhydrogen siloxane cyclic homopolymer having 3 to 10 silicon atoms per molecule, Alternatively, component (b) which is a crosslinking agent may be a filler, for example, silica treated with one of the above, and mixtures thereof.

[0038] In one embodiment, component (b) is selected from methylhydrogen polysiloxane blocked at both molecular ends with trimethylsiloxy groups; a copolymer of methylhydrogen siloxane and dimethylsiloxane blocked at both molecular ends with trimethylsiloxy groups; dimethylsiloxane blocked at both molecular ends with dimethylhydrogen siloxy groups; a copolymer of methylhydrogen siloxane and dimethylsiloxane blocked at both molecular ends with dimethylhydrogen siloxy groups.

[0039] The crosslinking agent (b) is generally 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 0.5:1 to 20:1. When this ratio is less than 0.5:1, a fully cured composition cannot be obtained. When this ratio exceeds 20:1, the hardness of the cured composition tends to increase when heated. Preferably, the molar ratio of the silicon-bonded hydrogen atoms of component (b) to the alkenyl / alkynyl groups, or 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.

[0040] The silicon-bonded hydrogen (Si-H) content of component (b) is determined using quantitative infrared analysis in accordance with ASTM E168. In the present invention, the ratio of silicon-bonded hydrogen to alkenyl (vinyl) and / or alkynyl is important when it depends on the hydrosilylation curing process. Generally, this is determined by calculating the total weight % of alkenyl groups in the composition, e.g., vinyl [V] and the total weight % of silicon-bonded hydrogen [H] in the composition, where if the molecular weight of hydrogen is 1 and the molecular weight of vinyl is 27, the molar ratio of silicon-bonded hydrogen to vinyl is 27 [H] / [V].

[0041] Typically, depending on the number of unsaturated groups in components (a) and (c) and the number of Si-H groups in component (b), component (b) is present in an amount of 0.1 to 10% by weight of the thermally conductive silicone rubber composition, or 0.1 to 7.5% by weight of the thermally conductive silicone rubber composition, or 0.5 to 7.5% by weight of the thermally conductive silicone rubber composition, or even 0.5% to 5% by weight.

[0042] Ingredient (c) Component (c) of the hydrosilylated (addition) curable thermal conductive silicone rubber composition used in the preparation of the fabric-reinforced thermal conductive silicone rubber tube described herein comprises an organopolysiloxane having a degree of polymerization of 4 to 500, and (i) at least one alkenyl group per molecule, and (ii) Used as a treatment agent for thermally conductive fillers (e.g., (e)(i) or (e)(ii)), comprising at least one hydroxyl group or at least one alkoxy group or a mixture of a hydroxyl group and an alkoxy group per molecule.

[0043] Therefore, each organopolysiloxane of component (c) has a degree of polymerization of 4 to 500, that is, as described with respect to component (a), formula (I): R' a SiO (4-a) / 2 (I) It has 400 to 500 siloxy units.

[0044] The subscript "a" is 0, 1, 2, or 3.

[0045] The unsaturated group of component (c) may be located at either the terminal or pendant of the polydiorganosiloxane, or at both positions if there is more than one (>1). The unsaturated group of component (c) may be an alkenyl group or an alkynyl group, as described above with respect to component (a).

[0046] In component (c), there may be at least one hydroxyl group or at least one alkoxy group or a mixture of a hydroxyl group and an alkoxy group per molecule. If present, the alkoxy group may have 1 to 20 carbon atoms per group, or 1 to 15 carbon atoms per group, or 1 to 12 carbon atoms per group, or 1 to 10 carbon atoms per group, or 1 to 6 carbon atoms per group, and methoxy, ethoxy, propoxy, butoxy, pentoxy, and / or hexoxy groups are preferred. The organopolysiloxane of component (c) may be linear or branched.

[0047] In component (c), which again refers to formula (I), each R' other than the unsaturated group described above, and at least one hydroxyl group or at least one alkoxy group or a mixture of a hydroxyl group and an alkoxy group per molecule, are independently selected from the same aliphatic hydrocarbyl groups, substituted aliphatic hydrocarbyl groups, aromatic groups, or substituted aromatic groups as described above with respect to component (a).

[0048] Component (c) may be selected from polydimethylsiloxane, alkylmethylpolysiloxane, alkylarylpolysiloxane, or copolymers thereof (where alkyl refers to any suitable alkyl group, or an alkyl group having two or more carbon atoms), provided that they have a degree of polymerization of 4 to 500. (i) at least one alkenyl group per molecule, and (ii) Each molecule contains at least one hydroxyl group or at least one alkoxy group or a mixture of a hydroxyl group and an alkoxy group.

[0049] The alkenyl group, hydroxyl group, and alkoxy group may be pendant groups or terminal groups. One preferred option is that the unsaturated group, hydroxyl group, and alkoxy group are terminal groups.

[0050] For example, component (c) in this specification is a linear or branched polydimethylsiloxane having one dimethylalkenyl terminus per molecule and one trialkoxy terminus per molecule or one hydroxyl dialkyl terminus per molecule, for example, M Vi D f It may be Si(OMe)3, which can also be written as follows:

[0051] [ka] In the formula, f is an integer such that the degree of polymerization is between 4 and 500, or f is an integer such that the degree of polymerization is between 4 and 250, or f is an integer such that the degree of polymerization is between 4 and 150, or f is an integer such that the degree of polymerization is between 4 and 100. An example of this is when f is 25, that is, M Vi D 25 This is the case when Si(OMe)3 is used, and other cases are described as follows.

[0052] [ka] Another example of component (c) may be a polydimethylmethylvinylsiloxane polymer or polymethylvinylsiloxane polymer having a degree of polymerization of 4 to 500 and having dialkylhydroxy or dialkylmethoxy terminators, as follows:

[0053] [ka] In the formula, R 1m is a hydroxyl or alkoxyl, m is 0 or an integer, and n is an integer such that the degree of polymerization is 4 to 500, or 4 to 250, or 4 to 150, or 4 to 100, or 4 to 50, for example, m + n = 4 to 17.

[0054] In all cases, component (c) has a degree of polymerization of 4 to 500, (i) at least one alkenyl group per molecule, and (ii) Each molecule contains at least one hydroxyl group or at least one alkoxy group or a mixture of a hydroxyl group and an alkoxy group.

[0055] A degree of polymerization of 4-500 means a viscosity of at least approximately 20 MPa·s at 25°C, and a number-average molecular weight (Mw) of the composition of at least approximately 300. Molecular weight can also be determined by gel permeation chromatography, but polymers at the lower end of the range with a DP of approximately 4-20 can be analyzed by gas chromatography-mass spectrometry (GC-MS).

[0056] Component (c) is present in the composition as specified in an amount of 0.1 to 10% by weight, or 0.1 to 5% by weight, or 0.25 to 5% by weight, or 0.25 to 2.5% by weight.

[0057] Ingredient (d) Component (d) of the hydrosilylation (addition) curable thermal conductive silicone rubber composition used in the preparation of the fabric-reinforced thermal conductive silicone rubber tubing described herein is a hydrosilylation catalyst comprising or consisting of a platinum group metal or a compound thereof. These are usually selected from catalysts of platinum group metals (platinum, ruthenium, osmium, rhodium, iridium, and palladium) or compounds of one or more such metals. Alternatively, platinum and rhodium compounds are preferred due to the high activity levels of these catalysts in the hydrosilylation reaction, with platinum compounds being most preferred. In the hydrosilylation (or addition) reaction, the hydrosilylation catalyst, such as component (d) herein, catalyzes the reaction between an unsaturated group, usually an alkenyl group, for example, vinyl and a Si-H group.

[0058] The hydrosilylation catalyst of component (d) may be a platinum group metal, a support such as activated carbon, a metal oxide such as aluminum oxide or silicon dioxide, a platinum group metal deposited on silica gel or powdered charcoal, or a compound or complex of a platinum group metal. Preferably, the platinum group metal is platinum.

[0059] Examples of preferred hydrosilylation catalysts for component (d) include platinum-based catalysts, e.g., platinum black, platinum oxide (Adams catalyst), platinum on various solid supports, chloroplatinic acid, e.g., hexachloroplatinic acid (Pt oxidation state IV) (Speier catalyst), chloroplatinic acid in solution of alcohol, e.g., isooctanolic acid or amyl alcohol (Lamoreaux catalyst), and complexes of chloroplatinic acid with ethylenically unsaturated compounds, e.g., olefins and organosiloxanes containing ethylenically unsaturated silicon-bonded hydrocarbon groups, e.g., tetra-vinyl-tetramethylcyclotetrasiloxane-platinum complex (Ashby catalyst). Examples of usable soluble platinum compounds include platinum-olefin complexes of the formula (PtCl2.(olefin)2 and H(PtCl3.olefin)), in which case the use of alkenes having 2 to 8 carbon atoms, such as ethylene, propylene, butene isomers and octene isomers, or cycloalkanes having 5 to 7 carbon atoms, such as cyclopentene, cyclohexene, and cycloheptene, is preferred. Other soluble platinum catalysts include, for example, platinum-cyclopropane complexes of the formula (PtCl2C3H6)2. The reaction products are those of hexachloroplatinic acid with alcohols, ethers, and aldehydes, or mixtures thereof, or those of hexachloroplatinic acid and / or its conversion products with vinyl-containing siloxanes such as methylvinylcyclotetrasiloxane in an ethanolic solution in the presence of sodium bicarbonate. Platinum complexes with vinylsiloxanes, such as platinum catalysts having phosphorus, sulfur, and amine ligands, e.g., (Ph3P)2PtCl2, and sym-divinyltetramethyldisiloxane, can also be used.

[0060] Therefore, specific examples of platinum-based catalysts with preferred component (d) include: (i) A complex of chloroplatinic acid and an organosiloxane containing an ethylenically unsaturated hydrocarbon group, as described in U.S. Patent No. 3,419,593, (ii) Chloroplatanic acid in either hexahydrate or anhydrous form, (iii) A platinum-containing catalyst obtained by a method comprising reacting chloroplatinic acid with an aliphatic unsaturated organosilicon compound such as divinyltetramethyldisiloxane, (iv)(COD)Pt(SiMeCl2)2 In the formula, "COD" is 1,5-cyclooctadiene, an alkene-platinum-silyl complex as described in U.S. Patent No. 6,605,734, and / or (v) Examples include the Karrstedt catalyst, which is a platinum divinyltetramethyldisiloxane complex, typically containing about 1% by weight of platinum in a vinylsiloxane polymer. While solvents such as organic solvents like toluene have historically been used as alternatives, the use of vinylsiloxane polymers is a far more preferred choice. These are described in U.S. Patents 3,715,334 and 3,814,730. In one preferred embodiment, component (d) may be selected from platinum coordination compounds. In one embodiment, hexachloroplatinic acid and its conversion products with vinyl-containing siloxanes, the Karrstedt catalyst, and the Speier catalyst are preferred.

[0061] The catalytic amount of the hydrosilylation catalyst is generally 0.01 ppm to 10,000 ppm, or 0.01 to 5,000 ppm, or 0.01 to 3,000 ppm, or 0.01 to 1,000 ppm, based on the weight of the composition, in parts by weight (ppm) of platinum group metals per million parts. In certain embodiments, the catalytic amount of the catalyst may range from 0.01 to 1,000 ppm, alternatively 0.01 to 750 ppm, alternatively 0.01 to 500 ppm, or alternatively 0.01 to 100 ppm, based on the weight of the composition. The range may relate only to the metal content in the catalyst, or to the catalyst as a whole (including its ligands), as specified, but typically these ranges relate only to the metal content in the catalyst. The catalyst may be added as a single type or as a mixture of two or more different types. Typically, depending on the form / concentration in which the catalyst is provided in the polymer or solvent, for example, the amount of component (d) present is in the range of 0.001 to 3.0% by weight of the composition, or 0.001 to 1.5% by weight of the composition, or 0.01 to 1.5% by weight of the thermally conductive silicone rubber composition, or 0.01 to 0.1.0% by weight.

[0062] Ingredients (e)(i) Component (e)(i) of the hydrosilyl (addition) curable thermal conductive silicone rubber composition used in the preparation of the fabric-reinforced thermal conductive silicone rubber tube described herein is, if present, at least one thermal conductive filler having a volume median particle size D(v,0.5) of 0.1 to 20 micrometers (μm) in an amount of 70 to 95% by weight of the composition, or 80 to 95% by weight of the composition.

[0063] The median volume particle size D(v,0.5) is defined as the value at which 50% of the distribution is above the specified value and 50% is below the specified value. 50This is the particle size value of the particle size distribution (or median particle size distribution). The thermal conductive filler (e)(i) may be a single thermal conductive filler, or a combination of two or more thermal conductive fillers that differ in at least one characteristic, such as particle shape, volume median particle size, particle size distribution, and type of filler. The volume median particle size D(v,0.5) values ​​used herein were obtained from the supplier's datasheet and / or measured by laser diffraction particle size analysis using a Malvern Mastersizer 2000 equipped with a Hydro 2000 MU dispersion unit. The parameters used were: particle refractive index (RI): 1.78 / 0.1; dispersant: water (1.33); obscuration: approximately 10%; internal stirring speed: 3000 rpm.

[0064] The sample was prepared before analysis by mixing 0.5 g of packing material with 25 mL of water, shaking, and then placed in a Hydro2000MU dispersion unit for internal sonication for 2 minutes.

[0065] 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 metallic silicon; Alloys, for example, alloys of one or more of bismuth, lead, tin, antimony, indium, cadmium, zinc, silver, aluminum, iron, and / or silicon; for example, Fe-Si alloy, Fe-Al alloy, Fe-Si-Al alloy, Fe-Si-Cr alloy, Fe-Ni alloy, Fe-Ni-Co alloy, Fe-Ni-Mo alloy, Fe-Co alloy, Fe-Si-Al-Cr alloy, Fe-Si-B alloy, and Fe-Si-Co-B alloy; Ferrite, Mn-Zn ferrite, Mn-Mg-Zn ferrite, Mg-Cu-Zn ferrite, Ni-Zn ferrite, and Ni-Cu-Zn ferrite and Cu-Zn ferrite; Metal oxides, such as aluminum oxide (alumina), zinc oxide, silicon oxide, magnesium oxide, beryllium oxide, chromium oxide, and titanium oxide; Metal hydroxides, such as magnesium hydroxide, aluminum hydroxide, barium hydroxide, and calcium hydroxide; Metal nitrides, such as boron nitride, aluminum nitride, and silicon nitride; Metal carbides such as silicon carbide, including boron carbide and titanium carbide; and Examples include metallic silicides such as magnesium silicide, titanium silicide, silicides, zirconium, tantalum silicide, niobium silicide, chromium silicide, tungsten silicide, and molybdenum silicide.

[0066] The thermally conductive filler (e)(i) may be a mixture of two or more of the above. In some embodiments, the thermally conductive filler (e)(i) may be a combination of a metal filler and an inorganic filler, such as a combination of an aluminum filler and an aluminum oxide filler, a combination of aluminum and a zinc oxide filler, or a combination of an aluminum filler, an aluminum oxide filler, and a zinc oxide filler.

[0067] Of the above, aluminum oxide, aluminum hydroxide, aluminum nitride, boron nitride, and mixtures thereof are preferred.

[0068] The shape of the thermally conductive filler particles (e)(i) is not particularly limited and may be, for example, powder and / or fibrous, but circular or spherical particles are preferred because they can prevent the viscosity from increasing to an undesirable level due to a high load of thermally conductive filler in the composition. Volume median particle size and D 50The particle size distribution depends on various factors, including the type of thermally conductive filler selected, the exact amount added to the curable composition, and the thickness of the bond line in the device in which the cured silicone product of the composition is used. In some specific examples, the thermally conductive filler (e)(i) may have a volume median particle size in the range of 0.1 to 20 micrometers (μm), or 0.1 to 15 micrometers, or 0.1 to 12.5 micrometers, as measured by laser diffraction particle size analysis. The hydrosilylated (addition) curable thermally conductive silicone rubber composition used in the preparation of the fabric-reinforced thermally conductive silicone rubber tubing described herein comprises the thermally conductive filler (e)(i), The composition comprises 70% to 95% by weight, or for example, 75% to 90% by weight, of a thermally conductive filler (e)(i), or for example, 80% to 90% by weight, of a thermally conductive filler (e)(i).

[0069] When the thermal conductive filler in the hydrosilylated (addition) curable thermal conductive silicone rubber composition used in the preparation of the fabric-reinforced thermal conductive silicone rubber tubing described herein is component (e)(i), preferably, neither precipitated silica nor fumed silica is present in the composition. In one embodiment, when at least one thermal conductive filler is component (e)(i), neither precipitated silica nor fumed silica is present in the composition described herein (except at trace levels).

[0070] As described above, in the hydrosilylated (addition) curable thermal conductive silicone rubber composition used in the preparation of the fabric-reinforced thermal conductive silicone rubber tube described herein, component (e)(i) may be replaced with a combination of components (e)(ii) and (f).

[0071] Components (e)(ii) If present, component (e)(ii) of the hydrosilyl (addition) curable thermal conductive silicone rubber composition used in the preparation of the fabric-reinforced thermal conductive silicone rubber tubing described herein is, if present, at least one thermal conductive filler having a median volume particle size D(v,0.5) greater than 20 to 100 micrometers (μm). Any suitable thermal conductive filler identified for component (e)(i) may be used for component (e)(ii), except that it requires a median volume particle size D(v,0.5) greater than 20 to 100 micrometers (μm) (determined in the same manner as above). Component (e)(ii) is the same as component (e)(i), except that it has a median volume particle size D(v,0.5) greater than 20 to 100 micrometers (μm), and therefore will not be repeated here. Median volume particle size and D of thermal conductive filler 50 The particle size distribution also depends on various factors, including the type of thermally conductive filler selected, the exact amount added to the curable composition, and the thickness of the bond line in the device in which the cured silicone product of the composition is used. In some specific examples, the thermally conductive filler (e)(ii) may have a volume median particle size in the range of greater than 20.0 to 100 micrometers (μm), or 25 to 90 micrometers, or 30 to 75 micrometers, as measured by laser diffraction particle size analysis.

[0072] In the combination, components (e), (ii), and (f) are present in an amount of 70-95% by weight of the composition.

[0073] Ingredients (f) A mixture of any two or more of precipitated silica, fumed silica, colloidal silica, or precipitated silica, colloidal silica, and fumed silica in an amount of more than 0 to 5% by weight of the composition. As described above, if the hydrosilylated (addition) curable thermal conductive silicone rubber composition used in the preparation of the fabric-reinforced thermal conductive silicone rubber tube described herein is component (e)(i), then preferably, neither precipitated silica, fumed silica, nor colloidal silica (component (f)) is present in the composition.

[0074] If the thermal conductive filler in the hydrosilyl (addition) curable thermal conductive silicone rubber composition used in the preparation of the fabric-reinforced thermal conductive silicone rubber tubing described herein is component (e)(ii), then component (f), which comprises precipitated silica, fumed silica, colloidal silica, or any two or more mixtures of precipitated silica, colloidal silica, and fumed silica, is also present in the composition in an amount greater than 0 to 5% by weight of the composition.

[0075] If present, the function of precipitated silica, fumed silica, and / or colloidal silica is to reinforce the composition. Such silica is preferably finely fragmented. Precipitated silica, fumed silica, and / or colloidal silica are typically present in a quantity of at least 50 m 2 / g (BET method according to ISO9277:2010), or 50 to at least 450m 2 It has a surface area of ​​ / g (BET method according to ISO9277:2010), or 50-300m 2 They are typically selected from silica with a relatively high surface area, having a surface area of ​​ / g (BET method according to ISO9277:2010). All of these types of silica are commercially available.

[0076] Typically, a thermally conductive silicone rubber tube reinforced with the fabric described herein, obtained from a thermally conductive silicone rubber composition comprising at least 70% by weight of the thermally conductive filler (e)(i) or (e)(ii) (in combination with (f)) described herein, has a high thermal conductivity of at least 0.5 W / mK, as measured according to the ASTM D7896-hot disk method.

[0077] The thermal conductivity of a woven-reinforced thermally conductive silicone rubber tube depends on the thermally conductive filler (e)(i) or (e)(ii) used. In the case of low-conductivity thermally conductive fillers (e)(i) or (e)(ii), such as aluminum oxide and aluminum hydroxide, if present in an amount of 70% by weight of the composition, the thermal conductivity of the product is typically 0.5 W / mK to 1.0 W / mK (ASTM D7896 - hot disk method). Therefore, in order for the cured silicone-based product to have a thermal conductivity of at least 2.0 W / mK (ASTM D7896 - hot disk method), the composition may require up to approximately 85% by weight of these thermally conductive fillers.

[0078] However, thermally conductive silicone rubber tubes reinforced with fabrics from the above thermally conductive silicone rubber composition will have greater thermal conductivity if the thermally conductive filler (e)(i) or (e)(ii) is a nitride such as aluminum nitride, silicon nitride, and / or boron nitride. In this case, they may have significantly higher thermal conductivity, for example, at least 2.0 W / mK (ASTM D7896 - Hot Disk Method).

[0079] As described above, when thermal conductive filler (e)(i) is present, the thermal conductive silicone rubber composition described herein comprises 70% to 95% by weight, or for example, 75% to 90% by weight, of thermal conductive filler (e)(i). When both thermal conductive fillers (e)(ii) are present, at least 80% by weight of the composition is thermal conductive filler (e)(ii), and component (f) is present in the composition, at least 75% by weight of the composition is thermal conductive filler (e)(ii), and at least 70% by weight of the composition is thermal conductive filler (e)(ii), and the cumulative amount of thermal conductive filler and reinforcing filler is at most 95% by weight when the latter is present.

[0080] Regular optional components Depending on its intended end use, additional optional components may be present in the hydrosilylated (addition) curable thermal conductive silicone rubber composition used in the preparation of the fabric-reinforced thermal conductive silicone rubber tubing described herein. Examples of such optional components include curing inhibitors, hydrophobic treatment agents (except for component (c) herein, to avoid ambiguity), compression set additives, pigments and / or colorants, as well as other additional additives such as metal deactivators, mold release agents, UV light stabilizers, bactericides, and mixtures thereof.

[0081] Optional hydrosilylation inhibitors The hydrosilylation (addition) curable thermal conductive silicone rubber compositions used in the preparation of the fabric-reinforced thermal conductive silicone rubber tubing described herein may also include one or more optional hydrosilylation inhibitors. Hydrosilylation inhibitors are used, if necessary, to prevent or delay the hydrosilylation inhibitor curing process, particularly during storage. Optional hydrosilylation inhibitors of platinum-based catalysts are well known in the art and include hydrazines, triazoles, phosphines, mercaptans, organic nitrogen compounds, acetylene alcohols, silylated acetylene alcohols, maleates, fumarates, ethylenically or aromatically unsaturated amides, ethylenically unsaturated isocyanates, olefinic siloxanes, unsaturated hydrocarbon monoesters and diesters, conjugated en-yines, hydroperoxides, nitriles, and diaziridines. Alkenyl-substituted siloxanes, such as those described in U.S. Patent No. 3,989,667, may also be used, of which cyclic methylvinylsiloxanes are preferred.

[0082] One known type of hydrosilylation inhibitor is an acetylene compound disclosed in U.S. Patent No. 3,445,420. Acetylene alcohols such as 2-methyl-3-butyne-2-ol constitute a preferred type of inhibitor that suppresses the activity of platinum-containing catalysts at 25°C. Typically, compositions containing these inhibitors need to be heated to temperatures above 70°C to cure at a practical rate.

[0083] Examples of acetylene alcohols and their derivatives include 1-ethynyl-1-cyclohexanol (ETCH), 2-methyl-3-butyne-2-ol, 3-butyne-1-ol, 3-butyne-2-ol, propargyl alcohol, 1-phenyl-2-propyne-1-ol, 3,5-dimethyl-1-hexyne-3-ol, 1-ethynylcyclopentanol, 3-methyl-1-penten-4-in-3-ol, and mixtures thereof. Examples of derivatives of acetylene alcohols include these compounds having at least one silicon atom.

[0084] If present, even low concentrations of hydrosilylation inhibitors, such as approximately 1 mole per mole of metal in catalyst (d), may, in some cases, still provide satisfactory storage stability and curing rate. In other cases, concentrations of up to 500 moles of hydrosilylation inhibitor per mole of metal in catalyst are required. The optimal concentration of a given hydrosilylation inhibitor in a given composition is easily determined by routine experiments. Depending on the concentration and form in which the selected hydrosilylation inhibitor is commercially available, if present in the composition, the inhibitor is typically present in an amount of 0.0125–10% by weight of the composition.

[0085] In one embodiment, the inhibitor, if present, is selected from 1-ethynyl-1-cyclohexanol (ETCH) and / or 2-methyl-3-butyne-2-ol and is present in an amount greater than 0 to 0.1% by weight of the composition.

[0086] If present, a hydrophobic treatment agent for treating component (f) If component (f) is present in combination with thermal conductive fillers (e) and (ii) in a hydrosilylated (addition) curable thermal conductive silicone rubber composition used in the preparation of the fabric-reinforced thermal conductive silicone rubber tubes described herein, then component (f), which is precipitated silica, fumed silica, and / or colloidal silica, (s) is naturally hydrophilic and therefore can be treated with a treatment agent to make it hydrophobic. Component (f) may be treated together with components (e) and (ii) using component (c), or separately with another hydrophobic treatment agent. In such cases, component (f) may be surface-treated with any suitable hydrophobic treatment agent other than component (c) disclosed in the art. For example, low molecular weight organosilicon compounds such as organosilanes, polydiorganosiloxanes, or organosilazanes, e.g., hexaalkyldisilazanes and short-chain siloxanediols. Specific examples, though not limited to them, include silanol-terminated trifluoropropylmethylsiloxane, silanol-terminated vinylmethyl (ViMe)siloxane, and silanol-terminated methylphenyl (methyl)siloxane. Examples of silanes include, but are not limited to, phenyl,MePh)siloxanes, liquid hydroxyldimethyl-terminated polydiorganosiloxanes containing an average of 2 to 20 repeating units of diorganosiloxane in each molecule, hexaorganodisiloxanes such as hydroxyldimethyl-terminated phenylmethylsiloxane and hexamethyldisiloxane, divinyltetramethyldisiloxane; hexaorganodisilazanes such as hexamethyldisilazane (HMDZ), divinyltetramethyldisilazane, and tetramethyldi(trifluoropropyl)disilazane; hydroxyldimethyl-terminated polydimethylmethylvinylsiloxane, octamethylcyclotetrasiloxane, and silanes including, but not limited to, methyltrimethoxysilane, dimethyldimethoxysilane, vinyltrimethoxysilane, methyltriethoxysilane, vinyltriethoxysilane, chlorotrimethylsilane, dichlorodimethylsilane, and trichloromethylsilane.In one embodiment, the treatment agent may be selected from silanes including, but not limited to, silanol-terminated vinylmethyl (ViMe)siloxanes, liquid hydroxyldimethyl-terminated polydiorganosiloxanes containing an average of 2 to 20 repeating units of diorganosiloxane in each molecule, hexaorganodisiloxanes such as hexamethyldisiloxane, divinyltetramethyldisiloxane; hexaorganodisilazanes such as hexamethyldisilazane (HMDZ), divinyltetramethyldisilazane, and hydroxyldimethyl-terminated polydimethylmethylvinylsiloxane, octamethylcyclotetrasiloxane, and methyltriethoxysilane, dimethyldiethoxysilane, and / or vinyltriethoxysilane. A small amount of water may be added together with the silica treatment agent as a processing aid.

[0087] Surface treatment of untreated component (f) may be carried out before or in situ before introduction into the composition, i.e., by blending these components together at room temperature or above until the fillers are completely treated, in the presence of at least some of the other components of the composition herein. If the treatment agent used is component (c), the reinforcing fillers and thermally conductive fillers (components (e)(ii)) may be treated simultaneously. If separate filler treatment agents are used for component (f) and component (e)(ii), they must be treated separately or sequentially.

[0088] Typically, any untreated component (f) is treated in situ with a treatment agent, preferably in the presence of a polydiorganosiloxane polymer (a), thereby preparing a silicone rubber base that can later be mixed with other components.

[0089] Optional compression set additives While compression set is not typically considered a critical performance characteristic for typical thermally conductive applications such as silicone greases, silicone gels, and gap fillers, standard thermally conductive silicone rubber compositions typically exhibit very high compression set due to the high load of thermally conductive fillers in the composition to achieve thermal conductivity. As discussed elsewhere, when a thermally conductive silicone rubber composition is designed to produce a high thermal conductivity, for example, of at least 1.5 W / mK (measured according to ASTM D7896 - Hot Disk Method), the required level of thermally conductive filler generally results in a pre-cured composition with significantly increased viscosity that impairs handling properties, and furthermore, upon curing, yields a cured silicone product with poor physical properties. While such products may be acceptable in some applications, in industry, compositions for producing cured materials, (i) a desired high level of thermal conductivity, and (ii) Required level of physical properties It has both, There is a growing demand for compositions that allow for the prediction of either one or the other in advance. In the past, large amounts of thermally conductive fillers present in thermally conductive silicone rubber compositions significantly reduced the elasticity / resilience of the silicone rubber; however, the compositions provided herein are considered to overcome this problem. Nevertheless, it has been confirmed that the inclusion of certain compression set additives in the hydrosilylated (addition) curable thermally conductive silicone rubber compositions used in the preparation of the fabric-reinforced thermally conductive silicone rubber tubing described herein, if desired, has a significant improvement effect on compression set. Compression set, as measured herein according to ASTM D395, is the permanent deformation remaining after the applied force is removed. This term is often a property that comes into play when using elastomers. Compression set occurs when a material is compressed to a specific deformation over a specific period of time at a specific temperature. Compression set testing measures the ability of rubber to return to its original thickness after prolonged compressive stress at a given temperature and deflection. Rubber materials lose their ability to return to their original thickness when compressed over a long period of time. This loss of resilience (memory) may reduce the ability of elastomer gaskets, seals, or cushioning pads to function over long periods. Permanent deformation that may occur in gaskets over time may cause leakage, or, in the case of impact insulation pads, may impair their ability to protect units that have been accidentally dropped. The result of compression set in a material is expressed as a percentage. The lower the percentage, the greater the material's resistance to permanent deformation under a given deflection and temperature range. Compression set additives used herein may be selected from, for example, dodecanedioic acid, bis[2-(2-hydroxybenzoyl)hydrazide], diphenyl sulfide, salicyloylaminotriazole, 1,2-di[-(3,5-di-tert-butyl-4-hydroxyp-phenyl)propionyl]hydrazine, copper(II) phthalocyanine, and mixtures thereof, for example, dodecanedioic acid, bis[2-(2-hydroxybenzoyl)hydrazide] and copper(II) phthalocyanine. If present, compression set additives are added to the composition in an amount of 0.01 to 5% by weight, or 0.01 to 2% by weight.

[0090] Optional pigments / colorants The hydrosilylated (addition) curable thermal conductive silicone rubber composition used in the preparation of the fabric-reinforced thermal conductive silicone rubber tubing described herein may further comprise one or more pigments and / or colorants, which may be added as desired. The pigments and / or colorants may be colored, white, black, metallic, and luminescent, such as fluorescent and phosphorescent.

[0091] Suitable white pigments and / or colorants include titanium dioxide, zinc oxide, lead oxide, zinc sulfide, lithopone, zirconium oxide, and antimony oxide.

[0092] Suitable non-white inorganic pigments and / or colorants include, but are not limited to, iron oxide pigments such as goethite, hematite, hematite, maghemite, and magnetite black iron oxide, yellow iron oxide, brown iron oxide, and red iron oxide; blue iron pigments; chromium oxide pigments; cadmium pigments such as cadmium yellow, cadmium red, and cadmium cinnabar; bismuth pigments such as bismuth vanadate and bismuth molybdate vanadate; mixed metal oxide pigments such as cobalt green titanate; chromate pigments and molybdate pigments such as chromium yellow, molybdate red, and molybdate 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.

[0093] Suitable organic non-white pigments and / or colorants include phthalocyanine pigments, e.g., phthalocyanine blue and phthalocyanine green; monoallylide yellow, diallylide yellow, benzimidazolon yellow, heterocyclic yellow, DAN orange, quinacridone pigments, e.g., quinacridone magenta and quinacridone violet; organic reds including metallated azored and non-metallated azored and other azo pigments; monoazo pigments; diazo pigments; azo pigment lakes; β-naphthol pigments; naphthol AS pigments; benzimidazolon pigments; diazo condensation pigments; isoindolinone and isoindoline pigments; polycyclic pigments; perylene and perinone pigments; thioindigo pigments; anthrapyrimidone pigments; flavanthron pigments; ansanthron pigments; dioxazine pigments; triarylcarbonium pigments; quinophthalone pigments; and diketopyrrolopyrrole pigments.

[0094] Pigments and / or colorants, if present, are present in amounts ranging from 2% by weight, or 3% by weight, or 5% by weight to 15% by weight, or 10% by weight of the composition.

[0095] Other optional additives Other optional additives in the hydrosilylated (addition) curable thermal conductive silicone rubber composition used in the preparation of the fabric-reinforced thermal conductive silicone rubber tubing described herein may include, as herein, metal deactivators, i.e., fuel and oil additives used to stabilize the liquid by deactivating (usually by sealing) metal ions introduced by the action of naturally occurring acids in the fuel and acids produced in the lubricant by oxidation processes with metal parts of the system, such as dodecanediic acid and bis[2-(2-hydroxybenzoyl)hydrazide].

[0096] Pot life extenders such as triazole may be used if desired, but are not considered necessary. Therefore, the thermally conductive silicone rubber composition does not need to contain a pot life extender.

[0097] Examples of flame retardants include aluminum trihydrate, chlorinated paraffin, hexabromocyclododecane, triphenyl phosphate, dimethylmethylphosphonate, tris(2,3-dibromopropyl) phosphate (brominated tris), and mixtures or derivatives thereof.

[0098] Therefore, in one alternative form, the hydrosilylated (addition) curable thermal conductive silicone rubber composition used in the preparation of the fabric-reinforced thermal conductive silicone rubber tube described herein is a) A polydiorganosiloxane having a degree of polymerization of at least 2,500 and at least two unsaturated groups per molecule, calculated from the number average molecular weight determined by gel permeation chromatography, wherein the unsaturated groups are selected from alkenyl groups or alkynyl groups, and present in the composition in an amount of 4% to about 30% by weight, or 6 to about 27% by weight, or 8 to 24% by weight, or 10 to 20% by weight, or the difference between 100% by weight and the cumulative amount of all other components present in the composition, b) an organosilicon compound having at least two or at least three Si-H groups per molecule, which is present in an amount of 0.1 to 10% by weight of the hydrosilylated (addition) curable thermal conductive silicone rubber composition used in the preparation of a fabric-reinforced thermal conductive silicone rubber tube, or 0.1 to 7.5% by weight of the hydrosilylated (addition) curable thermal conductive silicone rubber composition, or 0.5 to 7.5% by weight of the hydrosilylated (addition) curable thermal conductive silicone rubber composition, or a further 0.5% to 5% by weight of the component (b), c) An organopolysiloxane packing agent having a degree of polymerization of 4 to 500, calculated from the number average molecular weight determined by gel permeation chromatography, (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 a hydroxyl group and an alkoxy group per molecule An organopolysiloxane packing agent is included in an amount of 0.1 to 10% by weight of the composition, or 0.1 to 5% by weight, or 0.25 to 5% by weight of the composition, or 0.25 to 2.5% by weight of the composition. d) Depending on the form / concentration of the catalyst provided, a hydrosilylation catalyst comprising or consisting of platinum group metals or compounds thereof in an amount within the range of 0.001 to 3.0% by weight of the composition, or 0.001 to 1.5% by weight of the composition, or 0.01 to 1.5% by weight of the thermally conductive silicone rubber composition, or 0.01 to 0.1.0% by weight, (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% by weight of the composition, or in an amount of 80 to 95% by weight of the composition, (e)(ii) and (f) are combinations, (e)(ii) is at least one thermally conductive filler having a volume median particle size of more than 20 to 100 micrometers (μm) as measured by laser diffraction particle size analysis, f) A combination in which the composition is precipitated silica, fumed silica, colloidal silica, or any two or more mixtures of precipitated silica, colloidal silica, and fumed silica in an amount greater than 0 to 5% by weight of the composition. One of the following, Includes, The combination of (e)(ii)+(f) is present in the composition in an amount of 70-95% by weight, or in an amount of 80-95% by weight, provided that the total weight of the composition is 100% by weight.

[0099] The composition may also contain one or more of the above optional additives in specified amounts, wherein the total weight percentage of the composition is 100% by weight.

[0100] Prior to step (I) of the preparation of the fabric-reinforced thermal conductive silicone rubber tube described herein, the mixture of the aforementioned components (a), (b), and (d) from the hydrosilylated (addition) curable thermal conductive silicone rubber composition may begin to cure at temperatures above ambient temperature. Therefore, if the mixture of multiple components and additives needs to be stored between mixing and final use, the composition may be stored in multiple parts. However, given that a given component (a) in the hydrosilylated (addition) curable thermal conductive silicone rubber composition used in the preparation of the fabric-reinforced thermal conductive silicone rubber tube described herein is a high-viscosity polymer (more than 1,000,000 MPa·s at 25°C), often referred to in the industry as silicone gum, the composition is preferably mixed together as part of the process steps in producing the aforementioned tube to form a single-part composition.

[0101] In the latter case, where a partial composition is prepared, the hydrosilylated (addition) curable thermal conductive silicone rubber composition used in the preparation of the fabric-reinforced thermal conductive silicone rubber tube described herein may be prepared by combining all components together to form a partial composition. Typically, the base may be prepared first to allow the thermal conductive filler to be processed in situ, and then the remaining components may be introduced into the mixture in any preferred order. Any mixing techniques and apparatus described in the prior art can be used to complete step (I) of the process. The specific apparatus used will depend on the viscosity of the components and the final curable coating composition. Suitable mixers include, but are not limited to, paddle-type mixers, such as planetary mixers, and kneading-type mixers. However, if component (a) is a gum, mixing may preferably be carried out using, for example, a two-roll mill or kneading mixer. It may also be desirable to cool the components during mixing to avoid premature curing of the composition.

[0102] However, such hydrosilylated (addition) curable thermally conductive silicone rubber compositions may be stored in multiple parts, typically two parts, which are mixed together immediately before use if the composition is not prepared for immediate use. In such cases, the two parts are generally referred to as part (A) and part (B) and are designed to keep components (b) crosslinking agent and (d) catalyst separate in order to avoid premature curing.

[0103] Typically, in such cases, the Part A composition would include component (a) polymer, (c) treatment agent, (d) catalyst, and a combination of (e)(i) or (e)(ii) and (f), while Part B would include component (a) polymer, (b) crosslinking agent, (c) treatment agent, and a combination of (e)(i) or (e)(ii) and (f), as well as an inhibitor, if present. Any other additives present in the composition may be present in either Part A or Part B, provided they do not adversely affect the properties of any other component of choice (e.g., catalyst deactivation). While the use of a partial composition is preferred, if the hydrosilylated (addition) curable thermal conductive silicone rubber composition used in the preparation of the fabric-reinforced thermal conductive silicone rubber tubing described herein is stored in two parts, the Part A and Part B compositions are mixed together immediately before use to initiate curing of the entire composition into a silicone elastomer material. The compositions can be designed to be mixed in any suitable weight ratio. Typically, the A and B components are mixed together using a two-roll mill or a kneading mixer.

[0104] Each component of Part A and / or Part B may be mixed together individually, or they may be introduced into the composition in a pre-prepared combined state, for example, to facilitate mixing of the final composition. For example, component (a) and a combination of component (e)(i) or (e)(ii) and (f) may be mixed together to form a base composition. In such a case, the treatment agent component (c) is usually introduced into the mixture so that the thermally conductive filler (e) can be treated in situ. Alternatively, the combination of component (e)(i) or (e)(ii) and (f) may be pre-treated with component (c), but this is not preferred. The resulting base material may be divided into two or more parts, typically Part A and Part B, and appropriate additional components and additives may be added if necessary.

[0105] Once the hydrosilylated (addition) curable thermal conductive silicone rubber composition used in the preparation of fabric-reinforced thermal conductive silicone rubber tubing is prepared in process step (I), the resulting composition is introduced into a suitable extruder and extruded therefrom to form thermal conductive silicone rubber tubing (A), which is then cooled to or near room temperature, and the thermal conductive silicone rubber tubing (A) serves as the inner layer of the final fabric-reinforced thermal conductive silicone rubber tubing product.

[0106] Any suitable extruder can be used. The extruder may be a single-screw extruder or a twin-screw extruder, and may optionally be a horizontal extruder with a vertical extruder head. The extruder may have at least two heating tunnels, or two heating tunnels. If the extruder has two heating tunnels, the continuous first heating tunnel through which the hydrosilylated (addition) curable thermal conductive silicone rubber composition used to prepare the fabric-reinforced thermal conductive silicone rubber tube is transported is maintained at a higher temperature than the continuous second heating tunnel through which the composition is transported. For example, the temperature of the continuous first heating tunnel is maintained at 350°C to 600°C, or 350°C to 550°C, or 400°C to 500°C, and the temperature of the continuous second heating tunnel is maintained at 150°C to 300°C, or 200°C to 300°C, or 200°C to 250°C.

[0107] However, the hydrosilylated (addition) curable thermal conductive silicone rubber composition used in the preparation of fabric-reinforced thermal conductive silicone rubber passes through the first heating tunnel within approximately 20 seconds, for example, within 5 to 15 seconds or 5 to 10 seconds, and the composition passes through the second heating tunnel over a period of 60 to 420 seconds, or 90 to 360 seconds, or 100 to 300 seconds.

[0108] The above requirements enable a horizontal extruder equipped with a vertical extruder head to control the outer diameter (OD) and layer thickness of the tube, the latter preferably being 0.1 to 10.0 mm, or 0.25 to 7.5 mm, or 0.5 to 5.0 mm.

[0109] Once step (II) is completed and the resulting tube (A) has cooled sufficiently, the fiber layer is applied to the outer surface of the tube from step (II).

[0110] As described above, the fabric used is made from a fabric selected from glass fiber fabrics, polyester fiber fabrics, polyamide fiber fabrics, and / or polyaramid fiber fabrics, or a reinforcing fabric containing a mixture thereof that covers the tube (A). Step (III) may be carried out in any preferred manner, for example, the fabric may be in the form of a sleeve that slides over the pipe A made in step (II). Alternatively, the fibers may be woven or knitted onto the inner pipe (A), and then the fabric can be wrapped around the inner pipe A to form layer B.

[0111] In one embodiment, an optional priming step may be provided between steps (III) and (IV) to enhance the interaction between the reinforcing fabric and the Si tube layer. This can be achieved by applying an adhesive primer to the fabric. Any suitable adhesion promoter can be used, which may be one or more commercially available coupling agents dissolved in organic solvents, such as alkoxysilanes, ethoxysilanes, and titanates.

[0112] Following the application of fabric layer B, step (IV) is performed, but here, Using a process similar to that used to prepare inner tube A, the upper layer of the hydrosilyl (addition) curable thermal conductive silicone rubber composition is extruded onto / above fabric layer B.

[0113] Except for the extrusion head, the same extruder used in process (II) may be used in process (IV), and therefore the same temperature range may be used if desired, but the details will not be fully repeated here.

[0114] The thickness of the outer layer C may be designed to have a thickness of 0.1 to 10.0 mm, or 0.25 to 7.5 mm, or 0.5 to 5.0 mm, or 0.5 to 2.5 mm, or 0.5 to 2.0 mm. If desired, a thermally conductive silicone rubber tube reinforced with a fabric may be post-cured.

[0115] Post-curing is carried out within a temperature range of approximately 120°C to 200°C. The post-curing process may be carried out for a period of approximately 1 to 8 hours, as needed or desired.

[0116] The overall wall thickness of the fabric-reinforced thermal conductive silicone rubber tube prepared by this process is designed to meet the practical requirements of the tube's end application. For example, if the tube is used as a fabric-reinforced thermal conductive silicone rubber cooling tube positioned alongside 24 mm (OD) charging wires in a fast-charging device for EV applications, the outer diameter of the tube is 6-7 mm and the wall thickness is 1-2 mm.

[0117] The fabric-reinforced thermally conductive silicone rubber tubing described herein can be used as a cooling means in a wide variety of applications, including, for example, any cables / devices requiring a liquid cooling system in automotive and electronics applications, such as EV supercharging guns, high-power cooling cables, and any devices for heat dissipation components for motor drive modules and control modules. [Examples]

[0118] All viscosities were measured at 25°C unless otherwise specified. The viscosities of individual components in the following examples were measured using a Brookfield DV-III Ultra Programmable rheometer for viscosities of 50,000 mPa.s or higher, and a Brookfield DV 3T rheometer for viscosities below 50,000 mPa.s, unless otherwise specified. The SiH:vinyl molar ratio for all examples and comparative examples was 1.5:1.

[0119] A series of compositions for comparative formulations and examples of formulation compositions were prepared and are shown in Tables 1a and 1b, respectively.

[0120] [Table 1]

[0121] Furthermore, the above was compared with FC4, which is commercially available from Dow Silicones Corporation (Midland, Michigan, USA) as XIAMETER® RBB-2400-70 silicone rubber.

[0122] [Table 2]

[0123] The components specified in Tables 1a and 1b are as follows: Silicone gum 1 was a dimethylvinyl-terminated polydimethylsiloxane having a degree of polymerization (DP) of 5840 and a Williams plasticity of 150 mm / 100, according to ASTM D-926-08. Silicone rubber base 1: consists of 70.56% by weight of silicone gum 1 and 29.44% by weight of fumed silica sold by Wacker AG as HDK(trademark) T30P. Alumina 1 was ALM-41-01, sold by Sumitomo Chemical Co., Ltd. (Japan), with a particle size of 1-2 μm (according to the manufacturer's information). Alumina 2 was ADM-40K grade manufactured by Denka Co., Ltd., and the average particles were spherical alumina with a volume median particle size of 40 μm (according to the manufacturer's information). Treatment agent 1 is,

[0124] [ka] That was the case. Treatment agent 2: Dimethylhydroxy-terminated dimethyl, methyl vinylsiloxane having DP of 4-17. Si-H crosslinking agent 1 was a trimethyl-terminated dimethyl, methylhydrogensiloxane with a viscosity of approximately 15 mPa·s at 25°C. Si-H crosslinking agent 2 was a trimethyl-terminated dimethyl, methylhydrogensiloxane with a viscosity of approximately 5 mPa·s at 25°C. The Si-H / vinyl molar ratio of comparative formulations FC1, FC2, and FC3 was 1.5:1. ETCH is ethinylcyclohexanol.

[0125] A series of tests were conducted to evaluate the physical properties of each formulation reference example 1-5 and comparative example, according to the ASTM international standard test methods specified in Tables 2a and 2b below.

[0126] The samples for this test were prepared as follows:

[0127] First, the composition was prepared by gradually adding the silicone gum 1 (component (a)), silicone rubber base 1 starting material, and, if present, the thermal conductive filler and filler treatment agent, to a 5 L laboratory mixer, and then mixing at 120°C for 1 hour until homogeneous, thereby preparing an intermediate base composition. Next, the obtained base was cooled to room temperature. After cooling, the Si-H crosslinking agent, Karstedt catalyst, and hydrosilylation curing inhibitor were added and mixed into the composition using a two-roll mill. The obtained composition was then compression molded using a press curing apparatus, with a thickness of 2 mm, at 120°C for 10 minutes.

[0128] The thermal conductivity test was performed on a 6 mm thick slab that had been in a press-hardening apparatus at 120°C for 20 minutes. To evaluate any changes in thermal conductivity characteristics, the thermal conductivity test was also performed on a 6 mm thick slab that had been hardened at 200°C for 4 hours.

[0129] [Table 3]

[0130] [Table 4]

[0131] The physical properties of all comparative examples and reference examples were found to be acceptable. In each example and comparative example where a large amount of alumina filler was used to achieve the required level of thermal conductivity, the physical properties were clearly inferior compared to the commercially available XIAMETER® RBB-2400-70 silicone rubber. As mentioned above, the high-filled examples and comparative examples were found to have better thermal conductivity and extrudeability.

[0132] Next, each of the above compositions was tested for extrusion suitability and plasticity into tubes that are proven to be suitable, for example, as cooling tubes, and the results are shown in Tables 3a and 3b.

[0133] To evaluate extrusion properties, samples were prepared as follows: All components of the related composition were mixed together in a two-roll mill to form a partial composition. Once mixing was complete, the composition was introduced into a horizontal extruder equipped with a vertical extruder head having first and second heating tunnels. The composition was kept in the first heating tunnel for 6 to 10 seconds, maintained at a temperature range of 400°C to 500°C. It was then passed through the second heating tunnel and held at a temperature range of 200°C to 250°C for 100 to 300 seconds, after which the resulting extruded product was removed from the extruder head.

[0134] The capabilities of different comparative and example compositions were evaluated in terms of their suitability for extruding tubes.

[0135] F.Ex.1~5 were found to be suitable for extrusion to produce cooling tube analogues, etc., but considering the very high proportion of thermally conductive filler (alumina), while tubes can be easily prepared, the resulting products were not found to be strong enough to reliably withstand a liquid passing through the tube at a fluid pressure of at least 1 MPa according to the Chinese National Standard Test Method GB / T5563-2013 without rupture.

[0136] However, as described herein, by providing reinforcement in the shape of a second layer of reinforcing fibers in the composite tube, the resulting tube was found to satisfy the thermal conductivity value and to withstand the passage of liquid through the tube at a fluid pressure of at least 1 MPa in accordance with at least the Chinese National Standard Test Method GB / T5563-2013 without rupture.

[0137] [Table 5]

[0138] The comparative compositions were found to have poor extrudeability and plasticity values ​​of less than 200 mm / 100. The plasticity of these materials is not high enough to maintain consistency during extrusion; in other words, the raw strength of these materials is not sufficiently high. These materials could not be consistently conveyed by the screw. They broke and trapped air during screw extrusion.

[0139] [Table 6]

[0140] In contrast, F.Ex.1-5 all exhibited higher plasticity, particularly exceeding 200 mm / 100, and in fact exceeding 225 mm / 100, and were considered suitable for extrusion. To avoid any doubt, F.Ex.1-5 were all considered suitable for use as extrudeable hydrosilylated (addition) curable thermal conductive silicone rubber compositions necessary for producing the fabric-reinforced thermal conductive silicone rubber tubes described herein, but fabric reinforcement as described herein was considered necessary to ensure that the prepared tubes could reliably withstand the required fluid pressures.

[0141] Samples that consistently exhibited a stable OD (Obstruction Diode) and a smooth surface, and in which no bubbles or other defects were detected on the tube surface and / or cross-section of the tube, were considered to meet the criteria for good extrusion processability.

[0142] As evidence, a further series of examples were prepared, mainly based on the composition of F.Ex.5 as shown in Table 1b, and compared with the single-layer tubes of Ex.1 and comparative tubes prepared from the composition identified as C.4. The methods used are described below, and the results are shown in Table 4.

[0143] The process used to form the single-layer tubes in Comparative Examples C.1 and C.2 was carried out using the process described above.

[0144] For C.3, Ex.1, and Ex.2, woven thermal conductive silicone rubber tubes were fabricated using the following process: The components of the composition were mixed together in a two-roll mill, and the catalyst was added last. The resulting composition was introduced into a suitable horizontal extruder equipped with a vertical extruder head having first and second heating tunnels, and an inner layer tube with a wall thickness of approximately 0.7 mm was extruded for 6 to 10 seconds through the first heating tunnel, which was maintained at a temperature range of 400°C to 500°C. It was then extruded through the second heating tunnel and held at a temperature range of 200°C to 250°C for 100 to 300 seconds, and the resulting extruded product was removed from the extruder head. After the inner tube had cooled sufficiently, a second layer of polyethylene terephthalate reinforced fabric was woven onto the inner tube. After applying the fabric layer, an upper layer with a wall thickness of approximately 0.5 mm was extruded onto the woven fabric intermediate layer using the same method as the inner tube layer.

[0145] The hydrostatic tests in Tables 4a and 4b were conducted according to the Chinese National Standard Test Method GB / T5563-2013 for rubber and plastic hoses and hose assemblies, as previously mentioned.

[0146] [Table 7]

[0147] [Table 8]

[0148] Using tubes with a wall thickness (WT) of 1.0 or 1.2 mm prepared from the composition of Ex.1, good thermal conductivity results were obtained from the hydrosilylated (addition) curable thermal conductive silicone rubber composition used in the preparation of the fabric-reinforced thermal conductive silicone rubber tubes described herein. However, the GB / T5563-2013 results were relatively poor from compositions C.1 and C.2, suggesting that such tubes may rupture during use, for example, as cooling tubes for EV fast charging systems, and therefore were not sufficiently reliable 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 / T5563-201 results, undoubtedly partially aided by the presence of the reinforcing layer. However, this tube had a very low thermal conductivity result (almost zero). Ex.1 and Ex.2 provide very good composite tubes that have both high resistance to fluid (water) pressure and high thermal conductivity.

Claims

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

2. A thermally conductive silicone rubber tube reinforced with the fabric 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 thermally conductive silicone rubber tube reinforced with a fabric according to claim 1, having a thermal conductivity of at least 0.5 W / m.K. as measured according to ASTM D7896 - Hot Disk Method, and at the same time being able to withstand a fluid (e.g., water) pressure exceeding 1 MPa according to the standard test method GB / T5563-201.

4. A thermally conductive silicone rubber tube reinforced with the fabric described in claim 1, having a wall thickness of 0.50 to 10 mm.

5. A thermally conductive silicone rubber tube reinforced with the fabric described in claim 1, which is used as a water-cooling system tube for electric vehicle charging cables.

6. A method for preparing a thermally conductive silicone rubber tube reinforced with a fabric, I) The following ingredients: a) A polydiorganosiloxane having a degree of polymerization of at least 2,500 calculated from the number-average molecular weight determined by gel permeation chromatography and at least two unsaturated groups per molecule, wherein the unsaturated groups are selected from alkenyl groups or alkynyl groups, b) An organosilicon compound having at least two or at least three Si-H groups per molecule, c) An organopolysiloxane packing agent having a degree of polymerization of 4 to 500, calculated from the number average molecular weight determined by gel permeation chromatography, (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 a hydroxyl group and an alkoxy group per molecule The composition contains an organopolysiloxane filler treatment agent in an amount of 0.1 to 10% by weight, d) A hydrosilylation catalyst containing or consisting of platinum group metals or compounds thereof, (e) (i) At least one thermally conductive filler in an amount of 70 to 95% by weight of the composition, having a volume median particle size of 0.1 to 20 micrometers (μm) as measured by laser diffraction particle size analysis, or (e) is a combination of (ii) and (f), (e)(ii) is at least one thermally conductive filler having a volume median particle size of more than 20 to 100 micrometers (μm) as measured by laser diffraction particle size analysis, f) is any combination of precipitated silica, fumed silica, colloidal silica, or any two or more mixtures of precipitated silica, colloidal silica, and fumed silica in an amount of more than 0 to 5% by weight of the composition, A step of preparing a hydrosilylated (addition) curable thermal conductive silicone rubber composition containing, The step is to have the combination of (e), (ii) + (f) present in the composition in an amount of 70 to 95% by weight, and the total weight of the composition is 100% by weight. II) A step of introducing a hydrosilylated (addition) curable thermal conductive silicone rubber composition into an extruder, extruding the hydrosilylated (addition) curable thermal conductive silicone rubber composition from the extruder to form a thermal conductive silicone rubber tube (A), and cooling the tube, III) A step of covering the tube obtained from step (II) with a layer (B) of reinforcing fabric selected from glass fiber fabric, polyester fiber fabric, polyamide fiber fabric, and / or polyaramid fiber fabric, or any two or more mixtures thereof, to form the product of step (III), IV) A method comprising the step of extruding the outer layer (C) of the hydrosilylated (addition) curable thermal conductive silicone rubber composition from the extruder around the product of step (III) to form a fabric-reinforced thermal conductive silicone rubber tube.

7. A method for preparing a fabric-reinforced thermally conductive silicone rubber tube according to claim 6, wherein the extruder is optionally a horizontal extruder equipped with a vertical extruder head.

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

9. A method for preparing a fabric-reinforced thermally conductive silicone rubber tube according to claim 6, wherein component (a) of the composition is a silicone gum, the gum having a Williams plasticity of at least 100 mm / 100 as measured according to ASTM D-926-08.

10. A method for preparing a thermally conductive silicone rubber tube reinforced with a fabric according to claim 6, wherein the reinforcing fabric layer (B) is wrapped around or woven into the inner layer (A).

11. A thermally conductive silicone rubber tube reinforced with a fabric, manufactured according to any one of claims 6 to 10.

12. An electric vehicle charging cable water cooling system tube comprising or consisting of a thermally conductive silicone rubber tube reinforced with the fabric described in claim 11.

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

14. Use of a thermally conductive silicone rubber tube reinforced with the fabric according to any one of claims 1 to 5 in a cable and / or device liquid cooling system.

15. The use of a fabric-reinforced thermally conductive silicone rubber tube according to claim 14, wherein the cable and / or device liquid cooling system is located within or for an electric vehicle charging cable means.