Thermal conductive composition

Abstract

A composition comprising (A) an organopolysiloxane and (B) a thermal conductivity enhancing agent is provided, the thermal conductivity enhancing agent (B) comprises a first thermal conductivity enhancing agent having a particle size in the range of 50 to about 200 µm; a second thermal conductivity enhancing agent having a particle size in the range of 0.5 to about 120 µm; and optionally a third thermal conductivity enhancing agent having a particle size in the range of 0.01 to less than 15 µm.

Description

THERMAL CONDUCTIVE COMPOSITION FIELD OF INVENTION

[0001] The present invention relates to a composition comprising anorganopolysiloxane and a thermal conductivity enhancing agent comprising a first thermal conductivity enhancing agent, a second thermal conductivity enhancing agent, and a third thermal conductivity enhancing agent. BACKGROUND

[0002] With the development of electronic devices toward miniaturizationand high density and integration, the heat generation of electronic devices is gradually increasing, and thermal failure becomes the primary problem hindering the performance, reliability, and life of electronic devices. Hence, efficient thermal management becomes the key to solving this challenge. Thermal interface materials (TIMs) are widely employed between the two solid contact surfaces of heat sources and heat sinks to increase heat removal for electronic devices. These materials come in variety of formats such as greases, gap-fillers, pre-cured gels, curable materials (1 or 2 parts), phase change materials, elastomeric pads, adhesives, thermal tapes, metal alloys and solders etc. The gap between two solid surfaces (chip and heat sink) is uneven, and otherwise filled with air which has poor thermal conductivity. This gap is filled with a thermal interface material to provide the heat conduction pathway. Depending on the requirement, multiple thermal interface materials may be used between different solid surfaces to provide continuous conductive pathways for heat removal.

[0003] The advent of 5G communications technology, in telecom space andinternet of things (IoT) in consumer and industrial spaces will further elevate the performance requirement for TIMs. 5G and IoT devices (using 5G) work at higher frequencies, higher device densities, higher bandwidths, lower latency, small feature sizes and low power along with much higher reliability and availability requirements. These factors have made the heat removal requirement from electronic devices much more stringent and there is general trend in industry to 1 35749276.1move towards higher performance, i.e., higher thermal conductivity TIMs, for example going from low thermal conductivity of 3-5 W / mK to average of 6-10 W / mK and prompted for development of even higher thermal conductivities > 10 W / mK. The development of the next generations of integrated circuits (ICs), three- dimensional (3D) integration, and ultrafast high-power density communication devices makes the thermal management requirements extremely severe.

[0004] Conventional TIMs filled with thermally conductive particlesrequire high-volume fractions v of filler (v > 50%) like Alumina, ZnO to achieve thermal conductivity (TC) of the composite in the range of 1−5 W / mK. Many products also utilize metallic fillers like Aluminum when electrical conductivity conditions are relaxed. However, to achieve high TC (>10 W / mK) additional fillers such as BN, AlN, Diamond, SiC fillers and their combinations are disclosed in many patent applications. The advantage of these fillers is that they are electrically insulating and possess much higher thermal conductivities (High TC Fillers). Apart from thermal conductivity TIM formulations must demonstrate a range of other critical properties to be utilized in applications. These may include low thermal resistance, low volatiles, pump-out, bleed out, cracking, thermal stability, low hardness build up, high dispensing flow-rate for application at defined viscosities, shear-rate, pump pressure etc. Stability of properties during in low-high temperature cycling / shock also needs to be shown by conducting testing up to 500- 1000 hrs. These properties are achieved by careful design of TIM formulation combining high filler compositional loadings with suitable polymer-resin- dispersing agent combinations as disclosed below.

[0005] CN116814081A described a composition comprising a fillercombination of diamond, alumina and cubic boron nitride filler wherein cubic boron nitride is a mixture with the grain diameter of 5um and the grain diameter of 30um and the diamond with the grain diameter of 100um, along with nano alumina powder with the particle size of 30nm. The composition results in ultra-high heat conduction low dielectric interface material with the heat conductivity coefficient larger than 7 and the dielectric constant smaller than 5. 2 35749276.1

[0006] CN112457673A describes high-thermal-conductivity insulatingsilica gel gasket comprising of at least one of nano aluminum nitride, cubic boron nitride and nano silicon carbide and dodecyltrimethoxysilane modified spherical aluminum oxide. Through filler modification treatment and compounding design, the silica gel has excellent properties of high thermal conductivity, high insulation, chemical stability and the like, the thermal conductivity coefficient can reach 8 W / mK or above.

[0007] However, there is a scope for improving the thermal conductivityand hardness of such compositions. SUMMARY

[0008] The present invention offers compositions comprising polymer andmixture of thermal conductive fillers where the packing of the thermal conductive fillers in the composition provides high thermal conductivity while maintaining low hardness build up at very high temperature 150oC. The present invention incorporates cubic boron nitride as the key filler into thermal formulations. Here, we demonstrate that cubic boron nitride in combination with Alumina, AlN, BN, SiC, ZnO, fillers form an ideal combination, along with silicone polymers, resins to achieve >12W / mK of thermal conductivity with low hardness build up. All these formulations are electrically non-conducting.

[0009] The following presents a summary of this disclosure to provide abasic understanding of some aspects of the invention. This summary is intended to neither identify key or critical elements nor define any limitations of embodiments or claims. Furthermore, this summary may provide a simplified overview of some aspects that may be described in greater detail in other portions of this disclosure.

[0010] In one aspect, provided is a composition comprising:(A) an organopolysiloxane, wherein the organopolysiloxane comprises (i) an alkenyl-functionalized diorganopolysiloxane of formula (Ia) M1aM2bD1cD2dT1eT2fQg (Ia)M1= R1R2R3SiO1 / 2 3 35749276.1M2= R4R5R6SiO1 / 2D1= R7R8SiO2 / 2 D2= R9R10SiO2 / 2T1= R11SiO3 / 2 T2= R12SiO3 / 2Q = SiO4 / 2 where R2, R3, R4, R5, R6, R8, R9, R10, R12are each independently selected from an aliphatic, aromatic, or fluoro monovalent hydrocarbon having from 1 to 60 carbon atoms or alkoxy groups; R1, R7, R11are each independently selected from an aliphatic, aromatic, or fluoro monovalent hydrocarbon having from 1 to 60 carbon atoms and containing at least one terminal olefin bond; and the subscripts a, b, c, d, e, f, and g are zero or a positive integer subject to the following limitations: 1≤a+b+c+d+e+f+g ≤6000, and a+c+e≥1; and (ii) a hydrogen-functionalized organopolysiloxane of formula (Ib) M1a'M2b'D1c'D2d'T1e'T2f’'Qg'(1b) wherein: M1= R13R14R15SiO1 / 2M2= R16R17R18SiO1 / 2D1= R19R20SiO2 / 2D2= R21R22SiO2 / 2T1= R23SiO3 / 2T2= R24SiO3 / 2 Q = SiO4 / 2where R14, R15, R16, R17, R18, R20, R21, R22, R24are aliphatic, aromatic or fluoro monovalent hydrocarbon having from 1 to 60 carbon atoms; 4 35749276.1R13, R19, R23are hydrogen; the subscript a', b', c', d', e', f', and g' are zero or a positive integer subject to the following limitations: 1≤a'+b'+c'+d'+e'+f'+g' ≤6000, and a'+c'+e' ≥ 1; with the proviso that when a'+c'+e' =1 then a+c+e >1 and when a+c+e =1 then a'+c'+e' >1; or a crosslinked product of (i) and (ii) and (B) a thermal conductivity enhancing agent comprising a first thermal conductivity enhancing agent having particle size in the range of 50 to about 200 µm; a second thermal conductivity enhancing agent having particle size in the range of 0.5 to about 120 µm, and a third thermal conductivity enhancing agent having particle size in the range of 0.01 to 15 µm. As used herein, “particle size” refers to a volume average particle size unless the context indicates otherwise.

[0011] In one embodiment, the composition further comprises a dispersingagent represented by formula II,R25is a group having an alkoxysilyl group having 1 to 4 carbon atoms; R26is a linear organosiloxy group (III): 28 28 R R5 35749276.1wherein each R28is independently a monovalent hydrocarbon group having 1 to 12 carbon atoms; L is selected from a monovalent hydrocarbon group having 1 to 6 carbon atoms, and an alkoxysilyl group having 1 to 4 carbon atoms; and k is an integer from 10 to 500; each X is independently a divalent hydrocarbon group having 2 to 10 carbon atoms; each of h and i is independently an integer of 1 or more; j is an integer of 0 or more; h+i+j is an integer of 4 or more; and each R27is independently selected from hydrogen and a monovalent hydrocarbon group having 1 to 6 carbon atoms; or by formula IV 30 31 32 34 R R R ORwherein, R29represents an unsubstituted or substituted alkyl group, alkenyl group or aryl group, each R30represents, independently, an unsubstituted or substituted alkyl group, alkenyl group or aryl group, R31and R32each represent identical or different unsubstituted or substituted monovalent hydrocarbon groups, each R33represents, independently, a hydrogen atom, or an unsubstituted or substituted monovalent hydrocarbon group, each R34represents, independently, an unsubstituted or substituted alkyl group, alkoxyalkyl group, alkenyl group or acyl group, and n represents an integer from 2 to 20.

[0012] In another embodiment, the dispersing agent comprises two or morehydrolyzable organopolysiloxane compounds of the formula (II).

[0013] In still another embodiment, the dispersing agent comprises a firsthydrolyzable organopolysiloxane represented by formula (II) and having a value of k in the range of 10 to 50, and a second hydrolyzable organopolysiloxane represented by formula (II) and having a value of k in the range of 100 to 500.

[0014] In one embodiment, the organopolysiloxane comprises a H / Vi ratioof more than 0.4. 6 35749276.1

[0015] In yet another embodiment, the composition comprises a firstthermal conductivity enhancing agent in an amount of from about 15 wt.% to about 50 wt.% based on the total weight of the composition. The first thermal conductivity enhancing agent has an average particle size in the range of 50 to about 200 μm, preferably 80 to 150 μm.

[0016] In another embodiment, the first thermal conductivity enhancingagent is cubic boron nitride.

[0017] In another embodiment, cubic boron nitride has a surface oxygencontent of more than 5%.

[0018] In another embodiment, the composition comprises a second thermalconductivity enhancing agent in an amount of from about 20 wt.% to about 50 wt.% based on the total weight of the composition.

[0019] In another embodiment, the second thermal conductivity enhancingagent is selected from a group consisting of aluminum oxide, boron nitride, cubic boron nitride and aluminum nitride.

[0020] In another embodiment, the second thermal conductivity enhancingagent is present in a first average particle size in the range of 0.5 to less than 2 µm, a second average particle size in the range of 2 μm to less than 10μm, and a third average particle size in the range of 10 µm to about 120 µm.

[0021] In another embodiment, the second thermal conductivity enhancingagent having the first average particle size is present in an amount of from about 5 wt.% to about 25 wt.% based on the total weight of the composition; the second thermal conductivity enhancing agent having the second average particle size is present in an amount of from about 3 wt.% to about 10 wt.% based on the total weight of the composition; and the second thermal conductive filler having the third average particle size is present in an amount of from about 5 wt.% to about 25 wt.% based on the total weight of the composition.

[0022] In another embodiment, the second thermal conductivity enhancingagent is selected from aluminum nitride. 7 35749276.1

[0023] In yet another embodiment, a third thermal conductivity enhancingagent is selected from the group consisting of aluminum oxide, zinc oxide, SiC, and aluminum nitride.

[0024] In yet another embodiment, a third thermal conductivity enhancingagent is present in an amount of from about 1 wt.% to about 10 wt.% based on the total weight of the composition.

[0025] In another embodiment, the third thermal conductivity enhancingagent is zinc oxide having a particle size in the range of 0.01 to 15 µm.

[0026] In another aspect, provided is a device comprising a first substrate,a second substrate, and an interface material bridging an interface between the first and second substrate, wherein the thermal interface material comprises the one- component thermal-gel composition of any of the previous embodiments.

[0027] In another aspect, the present invention provides a heat dissipatingmaterial comprising the composition of the invention.

[0028] In another aspect, the present invention provides a method ofdissipating heat from a substrate, the method comprising contacting the substrate with the composition of the invention.

[0029] In yet another aspect, the present invention provides a method ofpreparing a treated substrate comprising applying the composition of the invention to a surface of a substrate.

[0030] In a further aspect, the present invention provides a devicecomprising a treated substrate wherein the treated substrate comprises the composition of the present invention.

[0031] The following description and the drawings disclose variousillustrative aspects. Some improvements and novel aspects may be expressly identified, while others may be apparent from the description and drawings. BRIEF DESCRIPTION OF DRAWING FIGURES

[0032] Figure 1 is a graph showing the hardness buildup data (Shore E) of1-Part Pre-cured silicone Gel CBN based thermal compositions at 150oC aging (Ex-3-7). 8 35749276.1DETAILED DESCRIPTION

[0033] Reference will now be made to exemplary embodiments, examplesof which are illustrated in the accompanying drawings. It is to be understood that other embodiments may be utilized, and structural and functional changes may be made. Moreover, features of the various embodiments may be combined or altered. As such, the following description is presented by way of illustration only and should not limit in any way the various alternatives and modifications that may be made to the illustrated embodiments. In this disclosure, numerous specific details provide a thorough understanding of the subject disclosure. It should be understood that aspects of this disclosure may be practiced with other embodiments not necessarily including all aspects described herein, etc.

[0034] As used herein, the words “example” and “exemplary” means aninstance, or illustration. The words “example” or “exemplary” do not indicate a key or preferred aspect or embodiment. The word “or” is intended to be inclusive rather than exclusive, unless context suggests otherwise. As an example, the phrase “A employs B or C,” includes any inclusive permutation (e.g., A employs B; A employs C; or A employs both B and C). As another matter, the articles “a” and “an” are generally intended to mean “one or more” unless context suggests otherwise.

[0035] As used herein, the term “thermal conductivity enhancing agent”means a solid compound or a mixture of compounds that enhances the thermal conductivity of a composition. Examples of thermal conductivity enhancing agent include, but are not limited to, solid inorganic compounds such as boron nitride, aluminum nitride, aluminum oxide, zinc oxide, aluminum metal, silicon carbide, carbon-based fillers like graphite and cubic boron nitride, metal fillers like aluminum, silver or a mixture thereof.

[0036] As used herein, the term “pre-cured gel” or “cross-linked siliconegel” means a fluid-extended polymer system which may include a continuous polymeric phase or network, which may be chemically, e.g., ionically or covalently, or physically cross-linked, and an oil, such as a silicone or other oil, a plasticizer, 9 35749276.1unreacted monomer, or other fluid extender which swells or otherwise fills the interstices of the network. The cross-linking density of such network and the proportion of the extender can be controlled to tailor the modulus, i.e., softness, and other properties of the gel. The term “pre-cured gel” also should be understood to encompass materials which alternatively may be classified broadly as pseudogels or gel-like as having viscoelastic properties similar to gels, such has by having a “loose” cross-linking network formed by relatively long cross-link chains, but as, for example, lacking a fluid-extender.

[0037] The expression “monovalent hydrocarbon” means any hydrocarbongroup from which one or more hydrogen atoms has been removed and is inclusive of alkyl, alkenyl, alkynyl, cyclic alkyl, cyclic alkenyl, cyclic alkynyl, aryl, aralkyl and arenyl and may contain heteroatoms.

[0038] The term “alkyl” means any monovalent, saturated straight,branched or cyclic hydrocarbon group; the term “alkenyl” means any monovalent straight, branched, or cyclic hydrocarbon group containing one or more carbon- carbon double bonds where the site of attachment of the group can be either at a carbon-carbon double bond or elsewhere therein; and, the term “alkynyl” means any monovalent straight, branched, or cyclic hydrocarbon group containing one or more carbon-carbon triple bonds and, optionally, one or more carbon-carbon double bonds, where the site of attachment of the group can be either at a carbon-carbon triple bond, a carbon-carbon double bond or elsewhere therein. Examples of alkyls include methyl, ethyl, propyl and isobutyl. Examples of alkenyls include vinyl, propenyl, allyl, methallyl, ethylidenyl norbornane, ethylidene norbornyl, ethylidenyl norbornene and ethylidene norbornenyl. Examples of alkynyls include acetylenyl, propargyl and methylacetylenyl.

[0039] The expressions “cyclic alkyl”, “cyclic alkenyl”, and “cyclicalkynyl” include bicyclic, tricyclic and higher cyclic structures as well as the aforementioned cyclic structures further substituted with alkyl, alkenyl, and / or alkynyl groups. Representative examples include norbornyl, norbornenyl, ethylnorbornyl, ethylnorbornenyl, cyclohexyl, ethylcyclohexyl, ethylcyclohexenyl, cyclohexylcyclohexyl and cyclododecatrienyl. 10 35749276.1

[0040] The term “aryl” means any monovalent aromatic hydrocarbongroup; the term “aralkyl” means any alkyl group (as defined herein) in which one or more hydrogen atoms have been substituted by the same number of like and / or different aryl (as defined herein) groups; and, the term “arenyl” means any aryl group (as defined herein) in which one or more hydrogen atoms have been substituted by the same number of like and / or different alkyl groups (as defined herein). Examples of aryls include phenyl and naphthalenyl. Examples of aralkyls include benzyl and phenethyl. Examples of arenyls include tolyl and xylyl.

[0041] The present disclosure provides reworkable pre-cured thermal gelcomposition consisting of cross-linked silicone gel, alkenyl-functionalized diorganopolysiloxane fluids, hydrogen-functionalized organopolysiloxane, alkoxy functionalized surface wetting agent (dispersing agent) or hydrolyzable organopolysiloxane, thermal conductive fillers, additives and pigments. By using dispersing agent and organofunctional silicone fluids, with cubic boron nitride and other thermal conductive fillers, ultra-high thermal conductivity was achieved. Even though these thermal compositions consisted of hard fillers like cubic boron nitride and AlN fillers, they showed remarkable thermal stability at very high temperature (150oC) for more than 1000h owing to not only the optimization of fillers and filler ratios but also optimization of composition of organofunctional silicone fluids along with dispersing agent.

[0042] In one-part pre-cured thermal gels compositions, thermalconductivity >12 W / mK with less hardness buildup was achieved (shore E was within the 25 even after 1000 h of aging at 150oC).

[0043] The combination of fillers is optimized to arrive at bestcombinations which can provide us with high TC as well as dispensable formulations. It may be noted that, as such any two or three or more fillers can be combined to arrive at a formulation, but such an approach seldom works and results in powdery or low TC Formulations. Only after doing DOE and optimization can we arrive at optimal filler combinations that enhance the filler packing, thus providing for high thermal conductivity while maintaining paste like rheology, viscosity and flow properties. The filler combination can be described as made up 11 35749276.1of 3 or more fillers – (C-1) is the largest filler type (50-200 μm), which provides the biggest crystal domain sizes to provide for high heat conductive path and thus enhanced thermal conductivity. For largest filler, intrinsically high TC materials like BN, cubic BN, SiC, Diamond and AlN, which enhances the overall conductivity of the formulation are utilized. The next fillers, (C-2) are the middle size fillers ~0.5-120 μm, which provide enhanced contacts and gap-filling between the large-fillers, these fillers are made up of Alumina, cubic BN or Aluminum Nitride powders or their combination. The smallest fillers (C-3) of D50 ~ 0.01-15 μm, which can be made up of ZnO, Alumina, SiC, and / or Aluminum nitride fillers or combination – these fillers even though they have large surface areas, they enhance the overall TC by building multitude of filler-polymer-dispersing agent contacts, along with filler-filler and filler-substrate contacts. They may also provide the desired lubrication and thixotropic effect for the formulation. As a result of careful experimental studies, we are demonstrating here, specific fillers and filler combinations, to be used as the heat conductive filler to achieve a heat conductive formulation that is excellent in thermal conductivity (>12W / mK), flexibility and moldability, and can be easily manufactured at low cost, and the present invention has been completed.

[0044] Herein, to achieve ultra-high thermal conductivity along with goodand stable dispensability and good thermal stability, filler optimization was done (cubic boron nitride along with other fillers) along with the optimization of organofunctional silicone fluids (organosilicone hydride, vinyl organosilicones, pre-cured silicone gel), and dispersing agent was optimized.

[0045] The disclosure may identify a number of different ranges for acomponent or components in the composition. It will be appreciated if the numerical values of the respective ranges can be combined to form new and non- specified ranges.

[0046] In one aspect, provided is a composition comprising:(A) an organopolysiloxane, wherein the organopolysiloxane comprises (i) an alkenyl-functionalized diorganopolysiloxane of formula (Ia) M1aM2bD1cD2dT1eT2fQg (Ia) 12 35749276.1wherein: M1= R1R2R3SiO1 / 2 M2= R4R5R6SiO1 / 2D1= R7R8SiO2 / 2 D2= R9R10SiO2 / 2T1= R11SiO3 / 2 T2= R12SiO3 / 2Q = SiO4 / 2 where R2, R3, R4, R5, R6, R8, R9, R10, R12are each independently selected from an aliphatic, aromatic, or fluoro monovalent hydrocarbon groups having from 1 to 60 carbon atoms or alkoxy groups; R1, R7, R11are monovalent radical containing at least one terminal olefin bond; and the subscripts a, b, c, d, e, f, and g are zero or a positive integer subject to the following limitations: 1≤a+b+c+d+e+f+g ≤6000, and a+c+e≥1; and (ii) a hydrogen-functionalized organopolysiloxane of formula (Ib) M1a'M2b'D1c'D2d'T1e'T2f’'Qg'(1b) wherein: M1= R13R14R15SiO1 / 2M2= R16R17R18SiO1 / 2D1= R19R20SiO2 / 2D2= R21R22SiO2 / 2T1= R23SiO3 / 2T2= R24SiO3 / 2 Q = SiO4 / 2where R14, R15, R16, R17, R18, R20, R21, R22, R24are aliphatic, aromatic or fluoro monovalent hydrocarbon groups having from 1 to 60 carbon atoms; 13 35749276.1R13, R19, R23are hydrogen; the subscript a', b', c', d', e', f', and g' are zero or a positive integer subject to the following limitations: 1≤a'+b'+c'+d'+e'+f'+g' ≤6000, and a'+c'+e' ≥ 1; with the proviso that when a'+c'+e' =1 then a+c+e >1 and when a+c+e =1 then a'+c'+e' >1; or a crosslinked product of (i) and (ii) and

[0047] (B) a thermal conductivity enhancing agent comprising a firstthermal conductivity enhancing agent having particle size in the range of 50 to about 200 µm; a second thermal conductivity enhancing agent having particle size in the range of 0.5 to about 120 µm , and a third thermal conductivity enhancing agent having particle size in the range of 0.01 to 15 µm.

[0048] The component (i) is an organopolysiloxane represented by formula(Ia) and having, in one molecule, at least two alkenyl groups bonded to silicon atoms. The viscosity of the component (i) at 25 °C may be in the range of 0.01 to 10 Pa·s, preferably 0.06 to 1 Pa·s. If the viscosity at 25 °C is below 0.01 Pa·s, the storage stability of the composition deteriorates, and if it exceeds 10 Pa·s, flowability cannot be maintained. The viscosity values mentioned above and elsewhere in the application are measured using a Brookfield rotary viscometer. The organopolysiloxane is not particularly limited as far as it meets the aforementioned viscosity and alkenyl group content and known organopolysiloxanes may be used. The molecular structure of the organopolysiloxane may be straight-chain, branched-chain, partially branched straight-chain, dendritic, or the like. Preferably, the structure is straight-chain or partially branched straight-chain. The component (i) may be a single polymer with such structure, a copolymer with such structure, or a mixture of two or more organopolysiloxanes having different viscosities. Further, the component (i) may be used in combination with a mono alkenyl-terminated organopolysiloxane having one alkenyl group bonded to a silicon atom per molecule. The viscosity of this organopolysiloxane at 25 °C may range from 0.001 to 1 Pa·s, preferably 0.006 to 0.1 Pa·s. Combining this organopolysiloxane with the component (i), an 14 35749276.1organopolysiloxane having at least two alkenyl groups bonded to silicon atoms per molecule, improves fluidity and facilitates, in the case of cured products, achieving the necessary low hardness for thermal interface materials.

[0049] The component (ii) is an organohydrogen polysiloxanerepresented by formula (Ib) and having hydrogen atoms directly bonded to silicon atoms. Specifically, it is an organohydrogen polysiloxane having at least two hydrogen atoms directly bonded to silicon atoms (hydrosilyl groups) in one molecule, and functions as a crosslinking agent for the component (i). The hydrosilyl groups of the component (ii) and the alkenyl groups of the component (i) are added together by way of a hydrosilylation reaction promoted by a platinum- based metal catalyst, later described, resulting in a three-dimensional network structure including crosslinked structures. If the number of hydrosilyl groups is less than two in the component (ii), curing is not obtained. The amount of addition of the component (ii) is such that the hydrosilyl groups of the component (ii) are 0.1 to 5.0 moles relative to one mole of alkenyl groups of the component (i), i.e., the molar quantity of hydrogen atoms directly bonded to silicon atoms is 0.1 to 5.0 times the molar quantity of alkenyl groups of the component (i), preferably 0.2 to 2.0 moles, and more preferably 0.3 to 1.0 moles. If the quantity of hydrosilyl groups of the component (ii) is less than 0.1 mole relative to one mole of alkenyl groups of the component (i), curing may not be obtained or the strength of the cured product may be insufficient, making it difficult to handle as a molded object. If it exceeds 5.0 moles, the flexibility of the cured product is lost, and the cured product becomes brittle.

[0050] In one embodiment, the composition further comprises a dispersingagent represented by formula II, 15 35749276.125 26 R RR25is a group having an alkoxysilyl group having 1 to 4 carbon atoms; R26is a linear organosiloxy group (III): 28 28 R Ra monovalent hydrocarbon group having 1 to 12 carbon atoms; L is selected from a monovalent hydrocarbon group having 1 to 6 carbon atoms, and an alkoxysilyl group having 1 to 4 carbon atoms; and k is an integer from 10 to 500; each X is independently a divalent hydrocarbon group having 2 to 10 carbon atoms; each of h and i is independently an integer of 1 or more; j is an integer of 0 or more; h+i+j is an integer of 4 or more; and each R27is independently selected from hydrogen and a monovalent hydrocarbon group having 1 to 6 carbon atoms; or by formula IV 30 31 32 34 R R R OR 3416 35749276.1wherein, R29represents an unsubstituted or substituted alkyl group, alkenyl group or aryl group, each R30represents, independently, an unsubstituted or substituted alkyl group, alkenyl group or aryl group, R31and R32each represent identical or different unsubstituted or substituted monovalent hydrocarbon groups, each R33represents, independently, a hydrogen atom, or an unsubstituted or substituted monovalent hydrocarbon group, each R34represents, independently, an unsubstituted or substituted alkyl group, alkoxyalkyl group, alkenyl group or acyl group, m represents an integer from 0 to 4, and n represents an integer from 2 to 20.

[0051] In another embodiment, the dispersing agent comprises two or morehydrolyzable organopolysiloxane compounds of the formula (II).

[0052] In still another embodiment, the dispersing agent comprises a firsthydrolyzable organopolysiloxane represented by formula (III) and having a value of k in the range of 10 to 50, and a second hydrolyzable organopolysiloxane represented by formula (III) and having a value of k in the range of 100 to 500.

[0053] In one embodiment, the organopolysiloxane comprises a H / Vi ratioof more than 0.4.

[0054] In yet another embodiment, the composition comprises a firstthermal conductivity enhancing agent in an amount of from about 15 wt.% to about 50 wt.% based on the total weight of the composition. The first thermal conductivity enhancing agent has an average particle size in the range of 50 to about 200 μm, preferably 80 to 150 μm.

[0055] In another embodiment, the first thermal conductivity enhancingagent is cubic boron nitride.

[0056] In another embodiment, cubic boron nitride has a surface oxygencontent of more than 5%.

[0057] In another embodiment, the composition comprises a second thermalconductivity enhancing agent in an amount of from about 20 wt.% to about 50 wt.% based on the total weight of the composition.

[0058] In another embodiment, the second thermal conductivity enhancingagent is selected from a group consisting of aluminum oxide, boron nitride, cubic boron nitride and aluminum nitride. 17 35749276.1

[0059] In another embodiment, the second thermal conductivity enhancingagent is present in a first average particle size in the range of 0.5 to less than 2 µm, a second average particle size in the range of 2 μm to less than 10μm, and a third average particle size in the range of 10 µm to about 120 µm.

[0060] In another embodiment, the second thermal conductivity enhancingagent having the first average particle size is present in an amount of from about 5 wt.% to about 25 wt.% based on the total weight of the composition; the second thermal conductivity enhancing agent having the second average particle size is present in an amount of from about 3 wt.% to about 10 wt.% based on the total weight of the composition; and the second thermal conductive filler having the third average particle size is present in an amount of from about 5 wt.% to about 25 wt.% based on the total weight of the composition.

[0061] In another embodiment, the second thermal conductivity enhancingagent is selected from aluminum nitride.

[0062] In yet another embodiment, a third thermal conductivity enhancingagent is selected from the group consisting of aluminum oxide, zinc oxide, SiC, and aluminum nitride.

[0063] In yet another embodiment, a third thermal conductivity enhancingagent is present in an amount of from about 1 wt.% to about 10 wt.% based on the total weight of the composition.

[0064] In another embodiment, the third thermal conductivity enhancingagent is zinc oxide having a particle size in the range of 0.01 to 15 µm.

[0065] In another aspect, provided is a device comprising a first substrate,a second substrate, and an interface material bridging an interface between the first and second substrate, wherein the thermal interface material comprises the one- component thermal-gel composition of any of the previous embodiments.

[0066] In another aspect, the present invention provides a heat dissipatingmaterial comprising the composition of the invention.

[0067] In another aspect, the present invention provides a method ofdissipating heat from a substrate, the method comprising contacting the substrate with the composition of the invention. 18 35749276.1

[0068] In yet another aspect, the present invention provides a method ofpreparing a treated substrate comprising applying the composition of the invention to a surface of a substrate.

[0069] In a further aspect, the present invention provides a devicecomprising a treated substrate wherein the treated substrate comprises the composition of the present invention.

[0070] It will be appreciated that the thermal conductivity enhancing agentmay comprise a mixture of a single type of compound where the mixture includes compounds of different average particle size. In one embodiment, the thermal conductivity enhancing agent comprises aluminum nitride, boron nitride, SiC, and aluminum oxide.

[0071] The particle size of the thermal conductivity enhancing agent maybe chosen as desired for a particular purpose or intended application. It will be appreciated that the composition may comprise a combination of thermal conductivity enhancing agents of different average particle sizes. Such combinations may be chosen as desired for a particular purpose or intended application. In one embodiment, the composition comprises a first thermal conductivity enhancing agent having an average particle size from about 50 to about 200 µm; a second thermal conductivity enhancing agent having an average particle size of about 0.5 µm to about 120 µm; and optionally a third thermal conductivity enhancing agent having an average particle size of about 0.01 µm to less than 15 µm. The first, second, and third thermal conductivity enhancing agents may be the same or different from one another in terms of the chemical makeup of the filler. Particle size can be determined by any suitable method. Average particle size is often provided or reported from the supplier of the material. The average particle size can be determined by measuring the particle size distribution by laser diffraction and scattering according to JIS R1629. In this study, the median diameter (D50) on a volume basis obtained from the measurement was used as the average particle diameter. 19 35749276.1

[0072] The filler(s) may be present in an amount of from about 80 wt.% toabout 99 wt.%, from about 82 wt.% to about 96 wt.%, or from about 85 wt.% to about 95 wt.% based on the total weight of the composition.

[0073] The cross-linked silicone gel may also be referred to herein as a pre-cured gel or a polymer gel. The cross-linked silicone gel is made by reacting the alkenyl-functionalized diorganopolysiloxane with hydrogen-functionalized organopolysiloxane. The reaction may be conducted via hydrosilylation reaction conditions using an appropriate catalyst. A conventional hydrosilylation catalyst are platinum-based catalysts (such as, but not limited to, Karstedt’s catalyst). In one embodiment, the pre-cured gel can be made by reacting a linear vinyl capped polysiloxanes with pendent poly(hydrosiloxane) or poly(methylhydrosiloxane) copolymers (cross-linker) or a crosslinked MT or MQ resin containing Si-H reactive groups through Pt catalyzed hydrosilylation reaction. A similar gel network can also be achieved by reacting a pendant vinyl silicone polymer with an end capped poly(hydrosiloxane) or poly(methylhydrosiloxane) copolymers or a crosslinked MT or MQ resin containing Si-H reactive groups via Pt catalyzed hydrosilylation route. The effective Si-H / Si-alkenyl mole ratio [r] which will be made to react to form a Si-C linkage must satisfy r ≤ 0.3. The final “Gel Rheology” must satisfy the condition a) 0.2 ≤ G′ ≤ 1000 (Pa); b) 0.1 ≤ G′′ / G′ ≤ 10; where the term G′ represents the “storage shear modulus” of the final pre-cured gel composition to be used in the thermal interface material formulation measured at T= 25oC under an oscillation frequency of 1 Hz or 6.28 rad / s by a stress or strain controlled rheometer, and the term G′′ represents the “loss shear modulus” of the final pre-cured gel composition to be used in thermal interface material formulation measured at T= 25oC under an oscillation frequency of 1 Hz or 6.28 rad / s by a stress or strain-controlled rheometer. G′′ and G′ are collectively measured in the respective viscoelastic region.

[0074] The following examples are intended to illustrate aspects andembodiments of the present technology. All parts and percentages are by weight 20 35749276.1and all temperatures are in Celsius unless explicitly stated otherwise. All patents, other publications, and U.S. patent applications referred to in the instant application are incorporated herein by reference in their entireties.

[0075] Examples

[0076] Steady shear viscosity and thixotropy were determined usingRheometer (RS-600) instrument with parallel plate geometry (measuring geometry gap was 500 µm).

[0077] Hardness test: The hardness of the gels was measured usingASTMD2240 Type durometer (Shore E) and ASTM D-217 penetrometer (penetration range: 0-400 Pen~40 mm; penetration time: 5 sec).

[0078] Hardness test of pre-cured (1-part) and post-cured (2-Part)formulations were measured using ASTMD2240 Type durometer (Shore E).

[0079] Bulk thermal conductivity of the thermal compositions wasmeasured using hot disk instrument at 22 °C and also ASTM D5470 was used to measure the thermal resistance and thermal conductivity.

[0080] Dispensability measurements were made by filling EFD's Optimum30cc syringe with 2 mm nozzle size with sample and dispensing at 90 psi, using an automatic dispenser Nordson EFD, and measuring the dispensed volume per minute.

[0081] BLT was determined by applying the compression at 1MPa for 30seconds on 10 x 10 x 0.5mm Si chip.

[0082] Crystallite size was measured by XRD using X-ray diffractometersystem with copper target (Kα line) of wavelength 1.54 Å, accelerating voltage of 40 kV, tube current of 30 mA, scan speed of 4° / min with step width of 0.02°.

[0083] Surface oxygen content was measured by XPS using X-rayPhotoelectron spectroscope with Al K alpha source, vacuum level of 2 X 10-9 Torr, hemispherical analyzer, dwell time of 0.7 sec, energy step of 1eV and HR scan 0.1eV.

[0084] The Pre-cured Gel thermal formulations were made in a Thinkymixer. First, the specific amount of dispersing agent, Vinyl PDMS fluids and gel were weighed in plastic container and mixed for 30 sec at 2000 rpm. To this 21 35749276.1mixture, fillers with the variable particle size were added step wise and all the materials were mixed using Thinky mixer at 2000 rpm for 30 sec at each step. In each step, after mixing for 30 sec, the formulation was hand mixed with broad blade spatula for 2 min. At the end, 1-2 times mixed for 30 sec at 2000 rpm to get the uniform paste.

[0085] 2-part curable formulations were also made similar to pre-cured gelformulations. A part and B part were made separately and mixed equal amount and cured at 70 oC for 1 h.

[0086] Two-part addition curable compositions were prepared according toexamples 1 to 2

[0087] Thermal Conductive pre-cured gel compositions were preparedaccording to the examples 3 to 7.

[0088] Table 1 provides properties of Two-part addition curable thermalcompositions.

[0089] Table 2 provides properties of Thermal Conductive pre-cured gelcompositions.

[0090] Divinyl terminated organopolysiloxane (A-1a) has a viscosity of 0.1Pa·s and represented by the following formula:to 400.

[0091] Divinyl terminated organopolysiloxane (A-1b) has aviscosity of 0.03 Pa·s and represented by the following formula:wherein each X is vinyl and n is 10 to 20 22 35749276.1

[0092] Monovinyl terminated organopolysiloxane (A-2a) has a viscosity of0.02 Pa·s and represented by the following formula:organopolysiloxane (A-2b) has a viscosity of0.01 Pa·s and represented by the following formula:

[0094] Crosslinker organohydrogenpolysiloxane (B-1) has the viscosityranges from 0.01 to 0.1 Pa·s with Si-H content from 0.05 to 0.5 wt%, and a compound of the following formula having a viscosity of 0.02 Pa·s is used in Examples:and p is 2 to 20

[0096] Cubic boron nitride was purchased from Funik (China).

[0097] Aluminum nitride was purchased from Toyo aluminium.

[0098] Nano Zinc oxide was procured from Zochem

[0099] Cubic BN with a volume-averaged particle size of 50-200 μm ((C-1a:90 μm), (C-1b:152 μm), (C-1c:95 μm), (C-1d:113 μm), (C-1e:114 μm)) with surface oxygen content of more than 5%. 23 35749276.1

[0100] Aluminum nitride with a volume-averaged particle size of 1.2 , 5, 20and 70 μm size (C-2a, C-2b, C-2c and C-2d respectively).

[0101] Nano Zinc oxide with a volume-averaged particle size of 0.16 μmsize (C-3).

[0102] (D-1) is a hydrolyzable organopolysiloxane (II-i) represented by acompound of the formula:

[0103] (D-2) is a hydrolysable polyorganosiloxane represented by acompound of the formula (II-ii):

[0104] E-1 is selected from Didodecyl3,3′-thiodipropionate or 2,4,6-Tris(3',5'-di-tert-butyl-4'-hydroxybenzyl)mesitylene used as an additive in the formulations. 24 35749276.1

[0105] F-1 is an inhibitor. Bis(1,1-dimethyl-2-propynyloxy) dimethylsilane

[0106] Example 1:

[0107] Part-A: Polysiloxanes A-1a (1.00 g) and A-2a (1.21 g), hydrolysablepolysiloxane D-1 (1.0 g), Pt-catalyst G-1 (18 wt% solution of Pt dimer complex (2 wt% Pt) in monovinyl terminated organopolysiloxane (viscosity 0.02 Pa·s)) (0.286 g) were weighed in plastic container and mixed for 30 sec at 2000 rpm using a Thinky mixer. To this mixture, thermal conducting fillers C-1a (45.0 g), C-2a (15.0 g), C-2b (10.0 g), C-2c (20.75 g), C-3 (5.75 g) were added step wise, and all the materials were mixed together using a Thinky mixer at 2000 rpm for 30 sec at each step. After 30 sec of each mixing, the formulation was hand mixed with broad blade spatula for 2 min. The mixture was further mixed in Thinky mixer at 2000 rpm for 30 sec. After mixing, the formulation was degassed at room temperature to remove any trapped air within. The total weight of the formulation was 100 g.

[0108] Part-B: Polysiloxanes A-1a (1.00 g) and A-2a (1.18 g), hydrolysablepolysiloxane D-1 (1.0 g), cross-linker B-1 (hydrogen functionalized organopolysiloxane) (0.12 g), inihibitor F-1 (Bis(1,1-dimethyl-2-propynyloxy) dimethylsilane) (1.5 wt% solution in hydrogen functionalized organopolysiloxane (viscosity 0.02 Pa·s) (0.2 g) were weighed in plastic container and mixed for 30 sec at 2000 rpm using a Thinky mixer. To this mixture, thermal conducting fillers C- 1a (45.0 g), C-2a (15.0 g), C-2b (10.0 g), C-2c (20.75 g), C-3 (5.75 g) were added step wise, and all the materials were mixed together using a Thinky mixer at 2000 rpm for 30 sec at each step. After 30 sec of each mixing, the formulation was hand mixed with broad blade spatula for 2 min. The mixture was further mixed in Thinky mixer at 2000 rpm for 30 sec. After mixing, the formulation was degassed at room temperature to remove any trapped air within. The total weight of the formulation was 100 g.

[0109] Example 2 was prepared same as example 1 where in

[0110] Part-A: Polysiloxanes A-1a (1.0 g) and A-2a (1.21 g), hydrolysablepolysiloxane D-1 (1.0 g), Pt-catalyst G-1 (18 wt% solution of Pt dimer complex (2 wt% Pt) in monovinyl terminated organopolysiloxane (viscosity 0.02 Pa·s)) (0.286 g) were mixed with thermal conducting fillers C-1b (45.0 g), C-2a (15.0 g), C-2b 25 35749276.1(10.0 g), C-2c (20.75 g), C-3 (5.75 g) The total weight of the formulation was 100 g.

[0111] Part-B: Polysiloxanes A-1a (1.0 g) and A-2a (1.18 g), hydrolysableD-1 (1.0 g), cross-linker B-1(hydrogen functionalized organopolysiloxane) (0.20 g), inihibitor F-1(Bis(1,1-dimethyl-2-propynyloxy) dimethylsilane) (1.5 wt% solution in hydrogen functionalized organopolysiloxane (viscosity 0.02 Pa·s)) (0.2 g) were mixed with thermal conducting fillers C-1b (45.0 g), C-2a (15.0 g), C-2b (10.0 g), C-2c (20.75 g), C-3 (5.75 g). The total weight of the formulation was 100 g.

[0112] Synthesis of Pre-cured gel or crosslinked Polysiloxane: Vinylstopped PDMS (500 g, MW ~ 17280 g / mol, Vinyl meq ~0.115) along with Pt catalyst (2 wt. % Karstedt’s catalyst, 10 ppm Pt) and inhibitor (Surfynol® 61, 200 ppm) were charged to a double planetary mixer at room temperature and allowed to mix at room temperature for 30 minutes at 20 rpm. To the reaction mixture at 50 oC, silicone hydride (55.4 g, MW ~ 40802, Hydride meq ~0.1586) was added and continued the mixing for an additional 1 hour at 20 rpm. While the mixing continues at the same speed at 50oC, the vacuum is applied for 60 minutes to remove the inhibitor to form the gel network. The reaction temperature then increases to 90 oC and is continued till all the hydride gets consumed and a gel is formed.

[0113] Example 3: Polysiloxanes A-1a (1.75 g), cross-linked polysiloxaneX-1 (1.0 g), hydrolysable polysiloxane D-1 (1.5 g) were weighed in plastic container and mixed for 30 sec at 2000 rpm using a Thinky mixer. To this mixture, thermal conducting fillers C-1c (48.5 g), C-2a (15.0 g), C-2b (5.0 g), C-2c (20.95 g), C-3 (6.0) were added step wise, and all the materials were mixed together using a Thinky mixer at 2000 rpm for 30 sec at each step. After 30 sec of each mixing, the formulation was hand mixed with broad blade spatula for 2 min. The mixture was further mixed in Thinky mixer at 2000 rpm for 30 sec. After mixing, the formulation was degassed at room temperature to remove any trapped air within. The total weight of the formulation was 100 g. 26 35749276.1

[0114] Example 4 was prepared same as example 3 where Polysiloxanes A-1a (1.75 g), cross-linked polysiloxane (1.0 g), hydrolysable polysiloxane D-1 (1.5 g) were mixed with thermal conducting fillers C-1a (48.5 g), C-2a (15.0 g), C-2b (5.0 g), C-2c (20.95 g), C-3 (6.0) The total weight of the formulation was 100 g.

[0115] Example 5 was prepared same as example 3 where Polysiloxanes A-1a (1.75 g), cross-linked polysiloxane (1.0 g), hydrolysable polysiloxane D-1 (1.5 g) were mixed with thermal conducting fillers C-1d (48.5 g), C-2a (15.0 g), C-2b (5.0 g), C-2c (20.95 g), C-3 (6.0). The total weight of the formulation was 100 g.

[0116] Example 6 was prepared same as example 3 where Polysiloxanes A-1a (1.75 g), cross-linked polysiloxane (1.0 g), hydrolysable polysiloxane D-1 (1.5 g) were mixed with thermal conducting fillers C-1e (48.5 g), C-2a (15.0 g), C-2b (5.0 g), C-2c (20.95 g), C-3 (6.0) The total weight of the formulation was 100 g.

[0117] Example 7 was prepared same as example 3 where Polysiloxanes A-1a (1.75 g), cross-linked polysiloxane (1.0 g), hydrolysable polysiloxane D-1 (1.5 g) were mixed with thermal conducting fillers C-1b (48.5 g), C-2a (15.0 g), C-2b (5.0 g), C-2c (20.95 g), C-3 (6.0) The total weight of the formulation was 100 g.

[0118] As shown in table 2 and Figure-1, composition comprising a mixtureof thermal conductivity enhancing agent and CBN showed better thermal conductivity and stability.

[0119] Ultra-high Thermal Conductive two-part addition curable thermalCompositions: Table 1 TIA2101GF Ex. 1 Ex. 2 Pt A P t B P t A P t B P t A P t B27 35749276.1TR (mm2K / W) (ASTM 27.3 28.2 31.3 29.9 D5470) ced

[0121] Two-part addition curable thermal compositions were made withdifferent filler percentage loading and achieved ultra-high thermal conductivity (>16 W / mK) with good dispensability (>13 g / min). By mixing 1:1 ratio of part-A and part-B, it was cured at 70oC for 1 h. The cured samples H / Vi ratios are in the range of 0.4-1.0.

[0122] As can be seen from table 2, examples 3, 4, 5, 6 and 7 show thermalconductivity >14 W / mK with less hardness buildup at high temperature of 150oC aging.

[0123] Ultra-high Thermal Conductive pre-cured gel compositions:Table 2 Ex.3 Ex.4 Ex.5 Ex.6 Ex.728 35749276.1Viscosity at 1 s-14190 2927 2607 16430 1536 (Pa·s)thermalgel formulations were designed and which gave very high thermal conductivity in the range from 12-16 W / mK (Table 2). Even though these thermal gel formulations are having hard fillers like AlN and Cubic Boron nitride fillers; and also, highly filler loaded thermal compositions, they showed very good thermal stability over very high temperatures. These thermal gel formulations showed very less hardness buildup at 150oC. For instance, Example 3, 4, 5 and 7 showed very less hardness buildup (Shore E) at 150oC even up to 1000 h of aging.

[0125] Figure 1 shows hardness buildup data (Shore E) of 1-Part Pre-curedsilicone Gel CBN based thermal compositions at 150oC aging (Ex-3-7).

[0126] What has been described above includes examples of the presentspecification. It is, of course, not possible to describe every conceivable combination of components or methodologies for purposes of describing the present specification, but one of ordinary skill in the art may recognize that many further combinations and permutations of the present specification are possible. Accordingly, the present specification is intended to embrace all such alterations, modifications and variations that fall within the spirit and scope of the appended claims. Furthermore, to the extent that the term “includes” is used in either the detailed description or the claims, such term is intended to be inclusive in a manner similar to the term “comprising” as “comprising” is interpreted when employed as a transitional word in a claim.

[0127] The foregoing description identifies various, non-limitingembodiments of thermal gel composition. Modifications may occur to those skilled in the art and to those who may make and use the invention. The disclosed embodiments are merely for illustrative purposes and not intended to limit the scope of the invention or the subject matter set forth in the claims. 29 35749276.1

[0128] Further embodiments of the present invention are provided in thefollowing.

[0129] Embodiment 1: A composition comprising:(A) an organopolysiloxane, wherein the organopolysiloxane comprises (i) an alkenyl-functionalized diorganopolysiloxane of formula (Ia) M1aM2bD1cD2dT1eT2fQg (Ia) wherein: M1= R1R2R3SiO1 / 2 M2= R4R5R6SiO1 / 2D1= R7R8SiO2 / 2 D2= R9R10SiO2 / 2T1= R11SiO3 / 2 T2= R12SiO3 / 2Q = SiO4 / 2 where R2, R3, R4, R5, R6, R8, R9, R10, R12are each independently selected from an aliphatic, aromatic, and fluoro monovalent hydrocarbon having from 1 to 60 carbon atoms or alkoxy groups; R1, R7, R11are each independently selected from an aliphatic, aromatic, or fluoro monovalent hydrocarbon having from 1 to 60 carbon atoms and containing at least one terminal olefin bond; and the subscripts a, b, c, d, e, f, and g are zero or a positive integer subject to the following limitations: 1≤a+b+c+d+e+f+g ≤6000, and a+c+e≥1; and (ii) a hydrogen-functionalized organopolysiloxane of formula (Ib) M1a'M2b'D1c'D2d'T1e'T2f'Qg'(1b)M1= R13R14R15SiO1 / 2 M2= R16R17R18SiO1 / 2D1= R19R20SiO2 / 2 D2= R21R22SiO2 / 2T1= R23SiO3 / 2 30 35749276.1T2= R24SiO3 / 2Q = SiO4 / 2 where R14, R15, R16, R17, R18, R20, R21, R22, R24are aliphatic, aromatic or fluoro monovalent hydrocarbon having from 1 to 60 carbon atoms; R13, R19, R23are hydrogen; the subscript a', b', c', d', e', f', and g' are zero or a positive integer subject to the following limitations: 1≤a'+b'+c'+d'+e'+f'+g' ≤6000, and a'+c'+e' ≥ 1; with the proviso that when a'+c'+e' =1 then a+c+e >1 and when a+c+e =1 then a'+c'+e' >1; or a crosslinked product of (i) and (ii) and (B) a thermal conductivity enhancing agent comprising a first thermal conductivity enhancing agent having particle size in the range of 50 to about 200 µm; a second thermal conductivity enhancing agent having particle size in the range of 0.5 to about 120 µm, and a third thermal conductivity enhancing agent having particle size in the range of 0.01 to 15 µm.

[0130] Embodiment 2: The composition according to Embodiment 1 furthercomprising a dispersing agent represented by formula II, 25 26 R RR25is a group having an alkoxysilyl group having 1 to 4 carbon atoms; R26is a linear organosiloxy group (III): 31 35749276.128 28 R R hydrocarbon group havinga monovalent hydrocarbon group having 1 to 6 carbon atoms, and an alkoxysilyl group having 1 to 4 carbon atoms; and k is an integer from 10 to 500; each X is independently a divalent hydrocarbon group having 2 to 10 carbon atoms; each of h and i is independently an integer of 1 or more; j is an integer of 0 or more; h+i+j is an integer of 4 or more; and each R27is independently selected from hydrogen and a monovalent hydrocarbon group having 1 to 6 carbon atoms; or by formula IV 30 31 32 34 R R R OR 34wherein, R29represents an unsubstituted or substituted alkyl group, alkenyl group or aryl group, each R30represents, independently, an unsubstituted or substituted alkyl group, alkenyl group or aryl group, R31and R32each represent identical or different unsubstituted or substituted monovalent hydrocarbon groups, each R33represents, independently, a hydrogen atom, or an unsubstituted or substituted monovalent hydrocarbon group, each R34represents, independently, an unsubstituted or substituted alkyl group, alkoxyalkyl group, alkenyl group or acyl group, and n represents an integer from 2 to 20.

[0131] Embodiment 3: The composition according to Embodiment 1wherein the organopolysiloxane comprises a H / Vi ratio of more than 0.4. 32 35749276.1

[0132] Embodiment 4: The composition according to Embodiment 2,wherein the dispersing agent is a compound represented by 25 26 R Rto Embodiment 4,wherein the dispersing agent comprises two or more hydrolyzable organopolysiloxane compounds of the formula (II).

[0134] Embodiment 6: The composition according to Embodiment 4,wherein the dispersing agent comprises a first hydrolyzable organopolysiloxane represented by formula (II) and having a value of k in the range of 10 to 50, and a second hydrolyzable organopolysiloxane represented by formula (II) and having a value of k in the range of 100 to 500.

[0135] Embodiment 7: The composition according to any one of theEmbodiments 1 to 6 wherein the composition comprises the first thermal conductivity enhancing agent in an amount of from 15 wt.% to 50 wt.% based on the total weight of the composition.

[0136] Embodiment 8: The composition according to Embodiment 7wherein the first thermal conductivity enhancing agent is cubic boron nitride.

[0137] Embodiment 9: The composition according to Embodiment 8 wherethe cubic boron nitride has a surface oxygen content of more than 5%.

[0138] Embodiment 10: The composition according to Embodiment 1 to 6wherein the second thermal conductivity enhancing agent is selected from the group consisting of aluminum oxide, boron nitride, cubic boron nitride and aluminum nitride. 33 35749276.1

[0139] Embodiment 11: The composition according to Embodiment 10wherein the composition comprises the second thermal conductivity enhancing agent in an amount of from 20 wt.% to 50 wt.% based on the total weight of the composition.

[0140] Embodiment 12: The composition according to Embodiment 10 or11 wherein the second thermal conductivity enhancing agent is present in a first average particle size in the range of 0.5 to less than 1.5µm, a second average particle size in the range of 1.5 µm to less than 10 µm, and a third average particle size in the range of 10 µm to 120 µm.

[0141] Embodiment 13: The composition according to Embodiment 12wherein the second thermal conductivity enhancing agent having the first average particle size is present in an amount of from 5 wt.% to 25wt.% based on the total weight of the composition; the second thermal conductivity enhancing agent having the second average particle size is present in an amount of from 3 wt.% to 10 wt.% based on the total weight of the composition; and the second thermal conductivity enhancing agent having the third average particle size is present in an amount of from 5 wt.% to 25 wt.% based on the total weight of the composition.

[0142] Embodiment 14: The composition according to any one of theEmbodiments 10 to 13 wherein the second thermal conductivity enhancing agent is selected from aluminum nitride.

[0143] Embodiment 15: The composition according to any one of theEmbodiments 1 to 6 wherein the third thermal conductivity enhancing agent is selected from the group consisting of aluminum oxide, zinc oxide, SiC, and aluminum nitride.

[0144] Embodiment 16: The composition according to any one of theEmbodiments 1 to 13 comprising the third thermal conductivity enhancing agent in an amount of from 1 wt.% to 10 wt.% based on the total weight of the composition.

[0145] Embodiment 17: The composition according to Embodiment 14wherein the third thermal conductivity enhancing agent is ZnO having a particle size in the range of 0.01 to 15 µm. 34 35749276.1

[0146] Embodiment 18: A device comprising a first substrate, a secondsubstrate, and an interface material bridging an interface between the first and second substrate, wherein the thermal interface material comprises the composition of any one of Embodiments 1 to 15.

[0147] Embodiment 19: A heat dissipating material comprising thecomposition of any one of Embodiments 1 to 15.

[0148] Embodiment 20: A method of dissipating heat from a substrate, themethod comprising contacting the substrate with the composition of any one of Embodiments 1 to 15.

[0149] Embodiment 21: A method of preparing a treated substratecomprising applying the composition of any one of Embodiments 1 to 15 to a surface of a substrate.

[0150] Embodiment 22: A device comprising a treated substrate whereinthe treated substrate comprises the composition of any one of Embodiments 1 to 15. 35 35749276.1

Claims

WE CLAIM:

1. A composition comprising:(A) an organopolysiloxane, wherein the organopolysiloxane comprises (i) an alkenyl-functionalized diorganopolysiloxane of formula (Ia) M1aM2bD1cD2dT1eT2fQg(Ia) wherein: M1= R1R2R3SiO1 / 2M2= R4R5R6SiO1 / 2 D1= R7R8SiO2 / 2D2= R9R10SiO2 / 2 T1= R11SiO3 / 2T2= R12SiO3 / 2 Q = SiO4 / 2where R2, R3, R4, R5, R6, R8, R9, R10, R12are each independently selected from an aliphatic, aromatic, and fluoro monovalent hydrocarbon having from 1 to 60 carbon atoms or alkoxy groups; R1, R7, R11are each independently selected from an aliphatic, aromatic, or fluoro monovalent hydrocarbon having from 1 to 60 carbon atoms and containing at least one terminal olefin bond; and the subscripts a, b, c, d, e, f, and g are zero or a positive integer subject to the following limitations: 1≤a+b+c+d+e+f+g ≤6000, and a+c+e≥1; and (ii) a hydrogen-functionalized organopolysiloxane of formula (Ib) M1a'M2b'D1c'D2d'T1e'T2f'Qg'(1b) wherein: M1= R13R14R15SiO1 / 2M2= R16R17R18SiO1 / 2 D1= R19R20SiO2 / 2D2= R21R22SiO2 / 2 T1= R23SiO3 / 236 35749276.1T2= R24SiO3 / 2Q = SiO4 / 2 where R14, R15, R16, R17, R18, R20, R21, R22, R24are aliphatic, aromatic or fluoro monovalent hydrocarbon having from 1 to 60 carbon atoms; R13, R19, R23are hydrogen; the subscript a', b', c', d', e', f', and g' are zero or a positive integer subject to the following limitations: 1≤a'+b'+c'+d'+e'+f'+g' ≤6000, and a'+c'+e' ≥ 1; with the proviso that when a'+c'+e' =1 then a+c+e >1 and when a+c+e =1 then a'+c'+e' >1; or a crosslinked product of (i) and (ii) and (B) a thermal conductivity enhancing agent comprising a first thermal conductivity enhancing agent having particle size in the range of 50 to about 200 µm; a second thermal conductivity enhancing agent having particle size in the range of 0.5 to about 120 µm, and a third thermal conductivity enhancing agent having particle size in the range of 0.01 to 15 µm.

2. The composition as claimed in claim 1, further comprising a dispersingagent represented by formula II, 25 26 R R IIR26is a linear organosiloxy group (III): 37 35749276.128 28 R R hydrocarbon groupfrom a monovalent hydrocarbon group having 1 to 6 carbon atoms, and an alkoxysilyl group having 1 to 4 carbon atoms; and k is an integer from 10 to 500; each X is independently a divalent hydrocarbon group having 2 to 10 carbon atoms; each of h and i is independently an integer of 1 or more; j is an integer of 0 or more; h+i+j is an integer of 4 or more; and each R27is independently selected from hydrogen and a monovalent hydrocarbon group having 1 to 6 carbon atoms; or by formula IV 30 31 32 34 R R R OR 34wherein, R29represents an unsubstituted or substituted alkyl group, alkenyl group or aryl group, each R30represents, independently, an unsubstituted or substituted alkyl group, alkenyl group or aryl group, R31and R32each represent identical or different unsubstituted or substituted monovalent hydrocarbon groups, each R33represents, independently, a hydrogen atom, or an unsubstituted or substituted monovalent hydrocarbon group, each R34represents, independently, an unsubstituted or substituted alkyl group, alkoxyalkyl group, alkenyl group or acyl group, and n represents an integer from 2 to 20.

3. The composition as claimed in claim 1, wherein the organopolysiloxanecomprises a H / Vi ratio of more than 0.

4. 38 35749276.

14. The composition as claimed in claim 2, wherein the dispersing agent is acompound represented by 25 26 R R5.agentcomprises two or more hydrolyzable organopolysiloxane compounds of the formula (II).

6. The composition as claimed in claim 4, wherein the dispersing agentcomprises a first hydrolyzable organopolysiloxane represented by formula (II) and having a value of k in the range of 10 to 50, and a second hydrolyzable organopolysiloxane represented by formula (II) and having a value of k in the range of 100 to 500.

7. The composition as claimed in any one of claims 1 to 6, wherein thecomposition comprises the first thermal conductivity enhancing agent in an amount of from 15 wt.% to 50 wt.% based on the total weight of the composition.

8. The composition as claimed in claim 7, wherein the first thermalconductivity enhancing agent is cubic boron nitride.

9. The composition as claimed in claim 8, wherein the cubic boron nitride has asurface oxygen content of more than 5%.

10. The composition as claimed in claim 1 to 6, wherein the second thermalconductivity enhancing agent is selected from the group consisting of aluminum oxide, boron nitride, cubic boron nitride and aluminum nitride. 39 35749276.

111. The composition as claimed in claim 10, wherein the composition comprisesthe second thermal conductivity enhancing agent in an amount of from 20 wt.% to 50 wt.% based on the total weight of the composition.

12. The composition as claimed in claim 10 or 11, wherein the second thermalconductivity enhancing agent is present in a first average particle size in the range of 0.5 to less than 1.5µm, a second average particle size in the range of 1.5 µm to less than 10 µm, and a third average particle size in the range of 10 µm to 120 µm.

13. The composition as claimed in claim 12, wherein the second thermalconductivity enhancing agent having the first average particle size is present in an amount of from 5 wt.% to 25wt.% based on the total weight of the composition; the second thermal conductivity enhancing agent having the second average particle size is present in an amount of from 3 wt.% to 10 wt.% based on the total weight of the composition; and the second thermal conductivity enhancing agent having the third average particle size is present in an amount of from 5 wt.% to 25 wt.% based on the total weight of the composition.

14. The composition as claimed in claim 10 to 13, wherein the second thermalconductivity enhancing agent is selected from aluminum nitride.

15. The composition as claimed in claim 1 to 6, wherein the third thermalconductivity enhancing agent is selected from the group consisting of aluminum oxide, zinc oxide, SiC, and aluminum nitride.

16. The composition as claimed in any one of claims 1 to 15, comprising thethird thermal conductivity enhancing agent in an amount of from 1 wt.% to 10 wt.% based on the total weight of the composition.

17. The composition as claimed in claim 16, wherein the third thermalconductivity enhancing agent is ZnO having a particle size in the range of 0.01 to 15 µm. 40 35749276.

118. A device comprising a first substrate, a second substrate, and an interfacematerial bridging an interface between the first and second substrate, wherein the interface material comprises the composition as claimed in any one of claims 1 to 17.

19. A heat dissipating material comprising the composition as claimed in anyone of claims 1 to 17.

20. A method of dissipating heat from a substrate, the method comprisingcontacting the substrate with the composition as claimed in any one of claims 1 to 17.

21. A method of preparing a treated substrate comprising applying thecomposition as claimed in any one of claims 1 to 17 to a surface of a substrate.

22. A device comprising a treated substrate wherein the treated substratecomprises the composition as claimed in any one of claims 1 to 15. 41 35749276.1

Images