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CN-122029209-A - Thermal interface material with high temperature aging properties

CN122029209ACN 122029209 ACN122029209 ACN 122029209ACN-122029209-A

Abstract

The thermally conductive composition comprises an isocyanate component comprising a blocked isocyanate prepolymer having a mole percent of 0.003 mole percent or greater, and one or more alkylalkoxysilanes comprising a C12 or higher alkyl chain, an isocyanate reactive component comprising one or more polyetheramines, and one or more catalysts selected from the group of carboxylates, tertiary amines, amidines, guanidine, and diazabicyclo compounds, and one or more glycol ether ester plasticizers present in one or more of the isocyanate component and the isocyanate reactive component, and a thermally conductive filler.

Inventors

  • P. AGARWAL

Assignees

  • 陶氏环球技术有限责任公司

Dates

Publication Date
20260512
Application Date
20231020

Claims (12)

  1. 1.A thermally conductive composition, the thermally conductive composition comprising: an isocyanate component comprising a blocked isocyanate prepolymer in a mole percentage of 0.003 mole% or greater, an One or more of the alkyl-alkoxy-silane, the one or more alkylalkoxysilanes comprise a C12 or higher alkyl chain; An isocyanate-reactive component that is capable of reacting, the isocyanate-reactive component comprises: one or more polyetheramines, and One or more catalysts selected from the group consisting of carboxylates, tertiary amines, amidines, guanidine, and diazabicyclo compounds, and One or more glycol ether ester plasticizers present in one or more of the isocyanate component and the isocyanate reactive component, and And a heat conductive filler.
  2. 2. The composition of claim 1, wherein the one or more glycol ether ester plasticizers are one or more glycol ether ester plasticizers selected from the group of glycol ether esters of the formula: (I) wherein R 1 is a saturated, unsaturated, and/or substituted carbon chain containing 2 to 12 carbon atoms, R 2 is hydrogen or methyl, R 3 is a saturated, unsaturated, and/or substituted carbon chain containing 2 to 12 carbon atoms, and n is an integer in the range of 1 to 4; formula (II): (II) Wherein R 1 and R 4 are independently saturated, unsaturated, and/or substituted carbon chains containing 2 to 12 carbon atoms, R 2 is hydrogen or methyl, R 3 is a saturated, unsaturated, and/or substituted carbon chain containing 2 to 12 carbon atoms, and n is an integer in the range of 1 to 4, or formula (III): (III) Wherein R 1 and R 3 are independently saturated, unsaturated and/or substituted carbon chains containing from 2 to 12 carbon atoms, R 2 is hydrogen or methyl, and n is an integer in the range of from 1 to 4.
  3. 3. The composition of claim 1, wherein the alkylalkoxysilane is present at 1.5 weight percent (wt%) or greater of the isocyanate component.
  4. 4. The composition of claim 1, wherein the alkylalkoxysilane can have a chemical structure Si (OR) n (R') 4-n , where n is an integer from 1 to 3, R is independently a C1 to C3 alkyl group, and R' is independently an alkyl group having 12 to 20 carbons.
  5. 5. The composition of claim 1, wherein the thermally conductive filler is a hydrophobic surface modified Aluminum Trihydrate (ATH).
  6. 6. The composition of claim 1, wherein the cured article exhibits less than 20% change in shore 00 hardness after 10 days aging at 100 ℃.
  7. 7. The composition of claim 1, wherein the isocyanate component exhibits <20% change in extrusion force after heating at 60 ℃ for 7 days.
  8. 8. The composition of claim 1, wherein the thermally conductive composition is compatible with butyl rubber as indicated by a butyl rubber hardness that does not change by more than 20% after 28 days of contact with the thermally conductive composition at 60 ℃.
  9. 9. The composition of claim 1, wherein the isocyanate-reactive component further comprises 0.5 to 2 wt% water.
  10. 10. The composition of claim 1, wherein the isocyanate-reactive component further comprises from 0.5 wt% to 2 wt% of one or more antioxidants.
  11. 11. A thermally conductive gap filler prepared by combining an isocyanate component and an isocyanate-reactive component and curing the resulting thermally conductive composition according to any one of claims 1 to 10.
  12. 12. A method of using the thermally conductive composition of any one of claims 1-11, the method comprising combining the isocyanate component and the isocyanate-reactive component, and placing the thermally conductive composition between a heat source and a heat sink in an EV battery.

Description

Thermal interface material with high temperature aging properties Technical Field Embodiments relate to thermally conductive compositions for use as thermal interface materials (such as gap fillers, sealants, gap pads or pastes) in applications requiring thermal management (such as electronic devices and automotive applications), and methods of use thereof. Background Thermal interface materials such as gap fillers, adhesives, and gels are widely used for thermal management in electronic devices and automotive applications. For example, an Electric Vehicle (EV) battery is cooled by mounting one or more battery modules to a cooling plate that redirects heat. For efficient cooling, good thermal contact between the battery module and the cooling plate is required. The gap filler bridges the gap and provides thermal contact between the battery module and the cooling plate. Thermal gap pads and dispensable gap fillers are two of the primary gap filler technologies. In both techniques, the dispensable gap filler has the advantage of providing more efficient heat transfer and less material wastage than thermal pads that may need to be trimmed and customized during installation. It is desirable to have a thermal interface material composition that has high thermal conductivity (> 0.5W/m.k), the ability to form a cured solid part without the application of heat, low density, and ease of processing. In addition, the physical properties of the thermal interface material should remain stable at high temperatures and resist thermal aging effects and degradation. Disclosure of Invention In one aspect, the thermally conductive composition comprises an isocyanate component comprising a blocked isocyanate prepolymer in the thermally conductive composition, the isocyanate component comprising a blocked isocyanate prepolymer comprising 0.003 mole percent or greater, and one or more alkylalkoxysilanes comprising a C12 or higher alkyl chain, an isocyanate reactive component comprising one or more polyetheramines, and one or more catalysts selected from the group of carboxylates, tertiary amines, amidines, guanidine, and diazabicyclo compounds, and one or more glycol ether ester plasticizers present in one or more of the isocyanate component and the isocyanate reactive component, and a thermally conductive filler. In another aspect, the thermally conductive gap filler may be prepared by combining an isocyanate component and an isocyanate-reactive component and curing the resulting thermally conductive composition. In another aspect, a method of using a thermally conductive composition is provided that includes combining an isocyanate component and an isocyanate-reactive component and placing the thermally conductive composition between a heat source and a heat sink in an EV battery. Detailed Description Embodiments disclosed herein relate to thermally conductive compositions for thermal management applications, including enhancing heat transfer in batteries, electronics, and automotive applications, among others. The thermally conductive composition may comprise an isocyanate component and an isocyanate-reactive component, which are combined and applied in situ to cure at room temperature and also exhibit durable shore OO hardness when aged at elevated temperatures. The isocyanate component may comprise a blocked isocyanate prepolymer composition and an alkylalkoxysilane having a C12 or higher alkyl chain, and the isocyanate-reactive component may comprise one or more polyetheramines. The thermally conductive composition may further comprise a combination of one or more of a viscosity-reducing glycol ether ester plasticizer, water, and an antioxidant that improves heat aging properties. The thermally conductive compositions disclosed herein can be formulated with plasticizers that improve processability while also being compatible with non-polar materials such as butyl rubber. For example, plasticizers may be selected that have properties such as polarity, water solubility, and viscosity that minimize plasticizer leaching into the surrounding non-polar material used in conjunction with the gap filler during installation, as well as low extrusion forces. During the cell assembly process, the gap filler composition is applied to the substrate and the cell module is assembled ("extruded") onto the pre-dispensed gap filler. Once installed, the high temperatures encountered during the life of the vehicle can degrade conventional gap fillers. To meet these needs, gap fillers can be investigated using thermal aging tests, which can involve heating the cured material to an elevated temperature for an extended period of time as a predictor of the long-term durability of the final product. The thermally conductive compositions disclosed herein may comprise a combination of alkylalkoxysilanes and plasticizers that reduce viscosity and reduce extrusion forces during preparation and application, while also producing materials that remain sta