Thermal conductive potting composition

Abstract

To provide a thermal conductive potting composition having a low viscosity, a high thermal conductivity, a high toughness and excellent thermal shock performance for new energy vehicles.SOLUTION: There is provided a thermal conductive potting composition, comprising: A) an epoxy resin having a viscosity of at least 500 mPa s at 25°C; B) a modified epoxy resin with at least three epoxy functional groups, having a viscosity of at least 10 mPa s and 1000 mPa s or less at 25°C; C) core shell nanoparticles, 20% by weight of which have a particle size of 0.01 to 1 μm; D) fillers, which comprises: D1) a silane surface-modified spherical alumina, which has an average particle size of more than 15 μm and 100 μm or less and D2) a thermal conductive powder having an average particle size of more than 0.01 μm and 15 μm or less; and E) a curing agent.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a thermally conductive potting composition, particularly to a thermally conductive potting composition having low viscosity, high thermal conductivity, high toughness (i.e., excellent bonding strength), and excellent thermal shock performance for new energy vehicles. [Background technology]

[0002] In order to reduce oil dependency, air pollution, and carbon dioxide emissions, the development of new energy vehicles (NEVs), which are vehicles that are partially or fully powered by electricity, such as battery electric vehicles (BEVs) and plug-in hybrid electric vehicles (PHEVs), has progressed rapidly in recent years worldwide, particularly in China. For example, the cumulative number of new energy vehicles sold in China increased from just 8,159 units in 2011 to 1,728,447 units in 2017.

[0003] With the development of the new energy vehicle industry, high horsepower requires high power density from electrical components such as batteries, motors, and generators. Smaller, lighter, and cheaper components will become increasingly popular. Such components will not only save space, but also improve operational efficiency and reduce costs. Traditional impregnation processes have not been able to meet the new thermal conductivity requirements. The application of thermally conductive potting compositions is an ideal method for effectively transferring heat from power components to heat sinks.

[0004] In new energy vehicles, the entire coil assembly is typically encapsulated in a casting resin, such as an epoxy resin. All spaces between the conductors are impregnated without voids or bubbles. The casting resin, which may be a potting composition, has a wide variety of properties. These include, for example, a low viscosity during processing to ensure complete impregnation of all spaces between the conductors (e.g., without voids or bubbles) and a high modulus of elasticity to provide high overall rigidity and thereby more accurate positioning of each winding. The casting resin may have good thermal conductivity to ensure efficient heat transfer from the conductor structure to the cooling layer. The casting resin may have high heat resistance, reflected by a high glass transition temperature, to achieve a property profile as consistent as possible over the operating temperature range. The casting resin may have a low thermal expansion coefficient (e.g., comparable to that of the other materials used (copper conductor, insulating layer)) to limit mechanical stresses (which can lead to cracks and delamination in the coil assembly when heated both during use and during cooling from the curing temperature) and thereby prevent simple crack formation. From this perspective, high crack resistance, high partial discharge resistance, low dielectric loss factor, flame retardancy, and economical efficiency should also be mentioned.

[0005] Epoxy-based casting resins can be used as potting compositions. For example, US 9,074,108 B2 discloses a potting composition comprising a support matrix in which at least one polymer nanoparticle filler is dispersed, and which is suitable for potting electronic components, particularly large-capacity coils such as gradient coils. Although this potting composition has good flame retardancy and low viscosity, it cannot meet the thermal management requirements of new energy vehicles, nor can it simultaneously meet the bonding requirements and thermal shock resistance requirements of new energy vehicles. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] US 9,074,108 B2 Summary of the Invention [Problem to be solved by the invention]

[0007] There is a need for thermally conductive potting compositions that have low viscosity, high thermal conductivity, high toughness and excellent thermal shock performance.

[0008] It is an object of the present invention to provide a thermally conductive potting composition that has low viscosity, high thermal conductivity, high toughness and excellent thermal shock performance. [Means for solving the problem]

[0009] The present invention provides A) an epoxy resin having a viscosity at 25°C of at least 500 mPa·s; B) a modified epoxy resin having at least three epoxy functional groups and a viscosity at 25°C of at least 10 mPa·s and not more than 1000 mPa·s; C) 20% by weight of which are core-shell nanoparticles having a particle size of 0.01 to 1 μm; D) D1) silane surface-modified spherical alumina having an average particle size of greater than 15 μm and less than or equal to 100 μm; and D2) Thermally conductive powder with an average particle size of greater than 0.01 μm and less than 15 μm a filler comprising: E) Hardener A thermally conductive potting composition is provided, comprising:

[0010] The present invention also provides a two-component thermally conductive potting composition comprising: Part A is A) an epoxy resin having a viscosity at 25°C of at least 500 mPa·s; B) a modified epoxy resin having at least three epoxy functional groups and a viscosity at 25°C of at least 10 mPa·s and not more than 1000 mPa·s; C) 20% by weight of which are core-shell nanoparticles having a particle size of 0.01 to 1 μm; D) D1) silane surface-modified spherical alumina having an average particle size of greater than 15 μm and less than or equal to 100 μm; and D2) Thermally conductive powder with an average particle size of greater than 0.01 μm and less than 15 μm A filler comprising comprising Part B is E) Hardener A two-component thermally conductive potting composition is provided, comprising:

[0011] The present invention further provides a use of the thermally conductive potting composition of the present invention or the two-component thermally conductive potting composition of the present invention for new energy vehicles.

[0012] The present invention also provides a new energy vehicle comprising the thermally conductive potting composition of the present invention or the cured product of the two-component thermally conductive potting composition of the present invention.

[0013] The thermally conductive potting composition of the present invention has low viscosity, high thermal conductivity, high toughness (ie, excellent bond strength), and excellent thermal shock performance for new energy vehicles. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a photograph of a device for measuring the thermal shock resistance of the compositions of Examples 1 to 5 and Comparative Examples 1 to 6. DETAILED DESCRIPTION OF THE INVENTION

[0015] The present invention will be described in more detail in the following paragraphs. Each described embodiment may be combined with other embodiments unless expressly stated to the contrary. In particular, any feature described as being preferred or advantageous may be combined with any other feature described as being preferred or advantageous.

[0016] Terms used in this specification shall be construed in accordance with the following definitions unless otherwise specified.

[0017] As used herein, the singular forms "a," "an," and "the" include both the singular and the plural unless the specification clearly indicates otherwise.

[0018] As used herein, the terms "comprises," "comprises," and "including" are synonymous with "include," "includes," or "contains," and are inclusive or open-ended and do not exclude additional, unrecited components, elements, or process steps.

[0019] The recitation of numerical endpoints includes all numbers and fractions subsumed within each range, as well as the recited endpoints.

[0020] All references cited herein are incorporated herein by reference in their entirety.

[0021] Unless otherwise defined, all terms used herein, including technical and scientific terms, have the meaning commonly understood by one of ordinary skill in the art to which this invention belongs. By way of further guidance, definitions of terms are included to better understand the teachings of the present invention.

[0022] In the present invention, the thermally conductive potting composition comprises: A) an epoxy resin having a viscosity at 25°C of at least 500 mPa·s; B) a modified epoxy resin having at least three epoxy functional groups and a viscosity at 25°C of at least 10 mPa·s and not more than 1000 mPa·s; C) 20% by weight of which are core-shell nanoparticles having a particle size of 0.01 to 1 μm; D) D1) silane surface-modified spherical alumina having an average particle size of greater than 15 μm and less than or equal to 100 μm; and D2) Thermally conductive powder with an average particle size of greater than 0.01 μm and less than 15 μm a filler comprising: E) Hardener The compound comprises:

[0023] A) Epoxy resin In the present invention, the epoxy resin has a viscosity at 25°C of at least 500 mPa·s, preferably at least 1000 mPa·s, more preferably at least 5000 mPa·s, and especially preferably at least 10000 mPa·s. Unless otherwise specified, all viscosity values herein are measured using a Brookfield Viscometer.

[0024] Preferably, the epoxy resin may be selected from the group consisting of bisphenol-A epoxy resin, bisphenol-F epoxy resin, cycloaliphatic epoxy resin and phenolic epoxy resin, and more preferably, the epoxy resin may be bisphenol-A epoxy resin.

[0025] Epoxy resins suitable for the present invention include, for example, NPEL-127, NPEL-127E, NPEL-127H, NPEL-128, NPEL-128E, NPEL-128G, NPEL-128R, NPEL-128S, NPEF-170, NPEF-180, NPEF-185, NPEF-187, NPEF-198, NPPN-630L, NPPN-630, and NPPN-631 (all commercially available from Nanya Epoxy Resin); 850 (commercially available from Blue Star New Chemical Materials Co., Ltd.); CYD 128 (commercially available from Baling Petrochemical Corporation); YD 128 (commercially available from Nippon Steel Chemical & Material Co., Ltd.); EP4100 (commercially available from ADEKA Corporation); R140 (commercially available from Mitsui Chemicals, Inc.); DER 331 (commercially available from Dow Chemical Company); NPEL128 (Nanya Epoxy Resin); and YD128 (available from Kukdo Chemical Co., Ltd.). A preferred example of a commercially available epoxy resin is NPEL-128.

[0026] The epoxy resin is present in an amount of 1 to 40 wt %, preferably 5 to 25 wt %, based on the total weight of the thermally conductive potting composition. If the epoxy resin content is less than 1%, the thermally conductive potting composition does not exhibit good bond strength and good thermal shock resistance. If the epoxy resin content is more than 40 wt %, the viscosity of the thermally conductive potting composition is too high, making it impossible to add a thermally conductive filler to the composition, and therefore the composition cannot exhibit low viscosity and high thermal conductivity.

[0027] B) Modified epoxy resin having at least three epoxy functional groups In the present invention, the modified epoxy resin having at least three epoxy functional groups has a viscosity at 25°C of at least 10 mPa·s and not more than 1000 mPa·s, preferably 50 to 800 mPa·s, and more preferably 100 to 600 mPa·s.

[0028] In a preferred embodiment, the modified epoxy resin contains three epoxy functional groups.

[0029] In the thermally conductive potting composition of the present invention, the modified epoxy resin having at least three epoxy functional groups acts as an epoxy-reactive diluent, not only reducing the viscosity of the composition but also participating in the curing reaction. Preferably, the modified epoxy resin can be selected from the group consisting of triglycidyl ethers. More preferably, the modified epoxy resin is trimethylolpropane triglycidyl ether.

[0030] Modified epoxy resins suitable for the present invention include, for example, Heloxy TM Modifier 48, Heloxy TM Modifier 84 and Heloxy TM Modifier 505 (all commercially available from Hexion Specialty Chemicals, Inc.); Epodil® 733 and Epodil® 762 (both commercially available from Evonik Industries AG). Preferred examples of commercially available modified epoxy resins include Heloxy TM Modifier 48.

[0031] The modified epoxy resin is present in an amount of 0.1 to 20 wt %, preferably 0.5 to 10 wt %, and more preferably 1.5 to 5 wt %, based on the total weight of the thermally conductive potting composition. If the content of the modified epoxy resin is less than 0.1%, the viscosity of the thermally conductive potting composition will not be reduced. If the content of the modified epoxy resin is greater than 20%, the thermally conductive potting composition will have poor physical properties, and the cured product of the potting composition will be very brittle.

[0032] C) Core-shell nanoparticles In the present invention, 20% by weight of the core-shell nanoparticles have a particle size of 0.01 to 1 μm, preferably 0.1 to 0.8 μm, more preferably 0.3 to 0.7 μm.

[0033] In the thermally conductive potting composition of the present invention, the core-shell nanoparticles act as a reinforcing agent. The core-shell nanoparticles suitable for the present invention may be any core-shell nanoparticles as long as they can be used for the purposes of the present invention. Preferably, the core-shell nanoparticles may be selected from the group consisting of reactive liquid rubbers such as carboxyl-terminated butadiene acrylonitrile (CTBN) liquid rubber, amine-terminated butadiene acrylonitrile (ATBN) liquid rubber, and vinyl-terminated butadiene acrylonitrile (VTBN) liquid rubber; preformed particles such as core-shell polymers or thermoplastic powders made from elastomer latex; and Interpentrating Polymer Network (IPN) reinforcing agents having a core-shell structure.

[0034] Modified epoxy resins suitable for the present invention include, for example, Hypox TM RA840 (available from CVC Thermoset Specialties); Kane Ace TM MX267, Kane Ace TM MX120, Kane Ace TM MX125, Kane Ace TM MX153, Kane Ace TM MX154, Kane Ace TMMX156, Kane Ace TM MX257, Kane Ace TM MX960, Kane Ace TM MX170, Kane Ace TM MX135, Kane Ace TM MX136, Kane Ace TM MX416, Kane Ace TM MX451, Kane Ace TM MX217 and Kane Ace TM MX717 (all commercially available from Kaneka Corporation).

[0035] The core-shell nanoparticles are present in an amount of 1 to 50 wt %, preferably 2 to 20 wt %, based on the total weight of the thermally conductive potting composition. If the content of core-shell nanoparticles is less than 1%, the toughness of the thermally conductive potting composition cannot be improved, the potting composition becomes too hard, and it does not exhibit thermal shock resistance. If the content of core-shell nanoparticles is more than 50%, the viscosity of the thermally conductive potting composition becomes too high, and its heat resistance becomes poor.

[0036] D) Filler D1) Silane surface-modified spherical alumina having an average particle size of greater than 15 μm and less than 100 μm In the present invention, the silane surface-modified spherical alumina has an average particle size of more than 15 μm and not more than 100 μm, preferably more than 15 μm and not more than 70 μm, more preferably more than 17 μm and not more than 35 μm.

[0037] In the present invention, the silane surface-modified spherical alumina may be modified with various types of polyfunctional silanes. The silane surface-modified spherical alumina suitable for the present invention is Hypox TM RA840 (available from CVC Thermoset Specialties); Kane Ace TM MX267 (available from Kaneka Corporation); and dynasylan 1146 and 9496 (both available from Evonik Industries AG). Preferably, the silane surface-modified spherical alumina is HypoxTM RA840 and Kane Ace TM MX267.

[0038] Preferably, component D1) contains 0.001 to 5% by weight of silane.

[0039] Component D1) is present in an amount of 30 to 80 wt. %, preferably 42 to 75 wt. %, more preferably 45 to 68 wt. %, based on the total weight of the thermally conductive potting composition.

[0040] D2) Thermally conductive powder with an average particle size of greater than 0.01 μm and less than 15 μm In the present invention, the thermally conductive powder has an average particle size of more than 0.01 μm and not more than 15 μm, preferably more than 2 μm and not more than 10 μm, more preferably more than 3 μm and not more than 5 μm.

[0041] The thermally conductive powder suitable for the present invention may be any thermally conductive powder having an average particle size of greater than 0.01 μm and less than or equal to 15 μm, as long as it can be used for the purposes of the present invention. For example, the thermally conductive powder of the present invention may be Al2O3, MgO, SiO2, Al(OH)3, Mg(OH)2, BN, AlN, SiC, SiN, or a combination thereof. Preferably, the thermally conductive powder of the present invention is a spherical alumina powder. For example, examples of thermally conductive powders include BAK-2, BAK-5, and BAK-10 (all commercially available from Bestry Performance Materials Corporation).

[0042] The thermally conductive powder is present in an amount of 5 to 80 wt %, preferably 8 to 50 wt %, and more preferably 10 to 25 wt %, based on the total weight of the thermally conductive potting composition. If the content of the thermally conductive powder is less than 5%, the thermal conductivity of the thermally conductive potting composition will be too low, and in this case, the thermally conductive powder will not be able to effectively dissipate heat from the device. If the content of the thermally conductive powder is more than 80%, the viscosity of the thermally conductive potting composition will be too high, which is disadvantageous for processing the potting composition.

[0043] E) Hardener In the present invention, the curing agent may be any curing agent as long as it can be used for the purpose of the present invention. Curing agents suitable for the present invention include anhydride and amine curing agents. Preferably, the curing agent may be selected from low viscosity anhydride and amine curing agents. More preferably, the curing agent may be selected from the group consisting of methylhexahydrophthalic anhydride and polyetheramine. For example, examples of curing agents include MHHPA (commercially available from Shangdong QING YANG Corporation); D230 (commercially available from Huntsman Corporation).

[0044] The curing agent is present in an amount of 1 to 20% by weight, preferably 5 to 15% by weight, based on the total weight of the thermally conductive potting composition. If the curing agent content is less than 1% or more than 20%, the thermally conductive potting composition cannot be cured.

[0045] The thermally conductive potting composition of the present invention may optionally contain various other additives. Optional additives in the potting composition include, for example, one or more types of cure accelerators, adhesion promoters, thixotropes, other adjuvants, or combinations thereof, to impart desired physical and chemical properties to each of Components A)-E) and / or mixtures of any two or more of Components A)-E), and to impart desired physical and chemical properties to the cured reaction product of the potting composition obtained therefrom. Of course, the additives must not adversely affect the properties of the cured reaction product that enable its use in the intended application.

[0046] Curing accelerator Cure accelerators are materials that significantly shorten gel time and / or accelerate the completion of cure. Various compounds, such as tertiary amines, imides, polyamines, cyclic amines, and arylamines, can be incorporated into the thermally conductive potting composition of the present invention. Potential accelerators include, but are not limited to, strong acids, organic and inorganic acids, fluoroacids, fluorosulfonic acids, fluoroacetic acids, water, alcohols, phenols, fluorophenols, salicylic acids, amines, calcium, and metal salts of any or all of the above acids, polyols, active hydrogen materials, and salts and / or complexes thereof. For example, a cure accelerator suitable for the present invention includes DMP-30 (commercially available from Huntsman Corporation).

[0047] Useful amounts of accelerators are typically in the range of 0 to 30% by weight of the total composition. Preferably, the accelerator is present in an amount of 0.001 to 10% by weight of the total composition.

[0048] Adhesion promoter The thermally conductive potting composition of the present invention can include one or more products to help improve the adhesion of the reaction product of the potting composition to the substrate surface. Useful adhesion-promoting materials include reaction products of epoxy resins with compounds containing chelate functional groups (referred to herein as "chelate-modified epoxy resins"), and functional silanes.

[0049] Such reaction products include materials commonly referred to as "chelating epoxies" or "chelating epoxy resins." Chelating functional groups include functional groups that can form chelate bonds with divalent or polyvalent metal atoms, either by themselves or in combination with other functional groups located on the same molecule. Chelating functional groups suitable for the present invention include, for example, phosphorus-containing acid groups (e.g., --PO(OH)), carboxylic acid groups (--COH), sulfur-containing acid groups (e.g., --SOH), amino groups, and hydroxyl groups (especially hydroxyl groups adjacent to each other on an aromatic ring). Preparation of such reaction products may be carried out by methods known to those skilled in the art, such as those described in U.S. Pat. Nos. 4,702,962 and 4,340,716, European Patent No. EP 342 035, and JP 58-063758 and JP 58-069265 (each of which is incorporated herein by reference in its entirety). Reaction products of epoxy resins and chelating functional group-containing compounds are also commercially available, examples of which include ADEKA Resins EP-49-10N, EP-49-55C, EP-49-10, EP-49-20, EP-49-23 and EP-49-25 (sold by Asahi Denka Co., Ltd.).

[0050] Other compounds having metal chelating properties may be used to help enhance adhesion of the reaction product of the potting composition to the substrate surface, including, for example, the adhesion promoters described in U.S. Patent Application Publication No. 2005 / 0129955, which is incorporated herein by reference in its entirety. Also suitable for use as an adhesion promoter is an acetoacetic acid functionalized modified resin sold by King Industries under the trade name K-FLEX XM-B301.

[0051] Some functional silanes include a reactive moiety that can bond or interact with the composition, a silane moiety that can react with the substrate, and / or other silane-modified materials and hydrolyzable moieties. Some epoxy-reactive moiety-containing functional silanes are sold by Momentive Performance Materials Inc. (Connecticut).

[0052] The thermally conductive potting compositions of the present invention may contain, for example, up to 6% by weight of an adhesion promoter, which can be incorporated into any one, two or more of components A) through E) as desired.

[0053] thixotrope Any suitable thixotrope can be incorporated into the thermally conductive potting composition of the present invention. Suitable thixotropic agents include, for example, Disparlon 6100, Disparlon 6200 (King Industries, Science Rd., Norwalk, Connecticut), organoclay, fumed silica, inert and / or functional fillers, plastic fillers, and polyamide powders. Useful amounts of thixotropes typically range from 0 to 30% by weight of the total composition. Preferably, the thixotrope is present in an amount of 1 to 10% by weight of the total composition.

[0054] auxiliary agent The thermally conductive potting compositions of the present invention can optionally include other common adjuvants such as flow aids, coupling agents (e.g., silanes), tackifiers, flame retardants, rheology modifiers, inhibitors, corrosion inhibitors, antioxidants, stabilizers, thickeners, plasticizers, elastomers, thermoplastic resins, colorants, shelf life extenders (e.g., zinc chloride), industrial microbiosaturates, surfactants or wetting agents (e.g., Zonyl® FSO available from DuPont), polymerization inhibitors, and other well-known additives, and combinations thereof, to further modify the physical and chemical properties of the potting composition and / or the cured reaction product obtained from the potting composition.

[0055] Depending on the properties required, the proportions of the individual components may vary within relatively wide ranges. Auxiliaries may be incorporated into any one, two or more of the components as required.

[0056] The thermally conductive potting composition of the present invention may be prepared by mixing components A) to E) together with other additives, if necessary, using a known method for preparing a thermally conductive potting composition. For example, the composition may be prepared by mixing the components in the amounts described above. The order of addition of the components is not particularly limited as long as a thermally conductive potting composition suitable for the purpose of the present invention is obtained.

[0057] In the thermally conductive potting composition of the present invention, components A) to D) and component E) can be stored separately. Just before use, all of the above components can be uniformly mixed to form the potting composition. In a preferred embodiment, the mixture is degassed under reduced pressure, since degassing under reduced pressure removes air bubbles upon mixing of the components. The mixed composition can be applied at room temperature or at an elevated temperature, preferably at 60°C. In another preferred embodiment, the product obtained therefrom is used for potting at 60°C with reduced pressure within 20 to 60 minutes.

[0058] In a preferred embodiment, the thermally conductive potting composition of the present invention comprises: A) 1 to 40% by weight of an epoxy resin having a viscosity at 25°C of at least 500 mPa·s; B) 0.1 to 20% by weight of a modified epoxy resin having at least three epoxy functional groups and a viscosity at 25°C of at least 10 mPa·s and not more than 1000 mPa·s; C) 1 to 50 wt. % of core-shell nanoparticles, 20 wt. % of which have a particle size of 0.01 to 1 μm; D) 30 to 80 wt. % of D1) silane-surface-modified spherical alumina having an average particle size of greater than 15 μm and less than or equal to 100 μm, and 5 to 80% by weight of D2) a thermally conductive powder having an average particle size of more than 0.01 μm and not more than 15 μm a filler comprising: E) 1 to 20% by weight of a curing agent wherein the weight ratios of the components are based on the total weight of the thermally conductive potting composition.

[0059] The present invention also provides a two-component thermally conductive potting composition comprising: Part A is A) an epoxy resin having a viscosity at 25°C of at least 500 mPa·s; B) a modified epoxy resin having at least three epoxy functional groups and a viscosity at 25°C of at least 10 mPa·s and not more than 1000 mPa·s; C) 20% by weight of which are core-shell nanoparticles having a particle size of 0.01 to 1 μm; D) D1) silane surface-modified spherical alumina having an average particle size of greater than 15 μm and less than or equal to 100 μm; and D2) Thermally conductive powder with an average particle size of greater than 0.01 μm and less than 15 μm A filler comprising comprising Part B is E) Hardener A two-component thermally conductive potting composition is provided, comprising:

[0060] When present, the above additives may be present in either or both parts A and B.

[0061] Part A and Part B are stored separately. The two parts and the above-mentioned additives, if present, can be uniformly mixed immediately before use to form the thermally conductive potting composition of the present invention. In a preferred embodiment, the mixture is degassed under reduced pressure, since degassing under reduced pressure removes air bubbles upon mixing of Parts A and B. The mixed composition can be applied at room temperature or at an elevated temperature, preferably at 60°C. In another preferred embodiment, the product obtained therefrom is used for potting at 60°C with reduced pressure within 20 to 60 minutes.

[0062] In one embodiment, Part A and Part B may each be components of a two-part potted package, with each part chemically separated and packaged for ease of use.

[0063] The thermally conductive potting compositions of the present invention can be used in applications such as new energy vehicles, including battery electric vehicles (BEVs) and plug-in hybrid electric vehicles (PHEVs), industrial equipment, and aerospace and consumer electronics.

[0064] Therefore, the present invention provides the use of the thermally conductive potting composition of the present invention or the two-component thermally conductive potting composition of the present invention for new energy vehicles, industrial equipment, aerospace and consumer electronics, and also provides a new energy vehicle comprising the thermally conductive potting composition of the present invention or the cured product of the two-component thermally conductive potting composition of the present invention.

[0065] The thermally conductive potting composition of the present invention has low viscosity, high thermal conductivity, high toughness (ie, excellent bond strength), and excellent thermal shock performance for new energy vehicles.

[0066] The following examples are intended to aid those skilled in the art in better understanding and practicing the present invention. The scope of the present invention is not limited by the examples, but is defined in the appended claims. All parts and percentages are by weight unless otherwise specified. [Example]

[0067] The following materials were used in the examples: NPEL 128 is commercially available from NAN YA EPOXY RESIN and is a liquid bisphenol A epoxy resin with a viscosity at 25°C of 12,000-15,000 mPa·s. HELOXY TM Modifier 48 is commercially available from Hexion Specialty Chemicals, Inc. and is a modified epoxy resin, trimethylolpropane triglycidyl ether, with a viscosity at 25° C. of 125-250 mPa·s and three epoxy functional groups. HELOXY TMModifier 8 is commercially available from Hexion Specialty Chemicals, Inc. and is a modified epoxy resin having a viscosity of 6-9 mPa·s at 25° C. and one epoxy functional group. ED523T is commercially available from ADEKA Corporation and is a modified epoxy resin with a viscosity of 18 mPa·s at 25° C. and two epoxy functional groups. AEROSIL® R974 is commercially available from Evonik Industries AG and has a viscosity of 170±20 m 2 / g BET surface area and a pH of 3.7 to 4.7. Hypox TM RA840, commercially available from CVC Thermoset Specialties, has a viscosity at 52°C of 150,000 to 230,000 mPa·s and is a liquid elastomer-modified bisphenol A epoxy resin and 20% by weight of its acrylonitrile containing core-shell nanoparticles with particle sizes between 0.01 and 1 μm.

[0068] Kane Ace TM MX267 is commercially available from Kaneka Corporation and has a viscosity of 7000 mPa·s at 50°C, and is a core-shell rubber nanoparticle with 20% by weight of the nanoparticles having a particle size of 0.01 to 1 μm. Fortegra 202 is a toughening agent commercially available from Dow Chemical Company and has a viscosity at 25°C measured according to ISO 3219 of 4500 to 10000 mPa·s. QS-N12 is commercially available from BEIJING JIN DAO QI SHI MATERIAL TECHNOLOGY CO., LTD. and is a pale yellow, transparent liquid toughening agent with a viscosity at 25°C of less than 4000 mPa·s. QS-VA-3 is commercially available from BEIJING JIN DAO QI SHI MATERIAL TECHNOLOGY CO., LTD. and is a yellow to light brown, transparent liquid toughening agent with a viscosity at 25°C of less than 8000 mPa·s. BAK-20 is commercially available from Yaan Bestry Performance Materials Corporation and is a silane surface modified spherical alumina with an average particle size of 20±2.0 μm. SJR-20 is commercially available from AnHuI Estone Materials Technology Co., Ltd. and is a crystalline quartz crystal with an average grain size of 20 μm.

[0069] BAH-20H4 is commercially available from Yaan Bestry Performance Materials Corporation and is a spherical alumina powder with an average particle size of 20 μm. BAH-40 is commercially available from Yaan Bestry Performance Materials Corporation and is a spherical alumina powder having an average particle size of 40 μm. BAK-5 is commercially available from Yaan Bestry Performance Materials Corporation and is a spherical alumina powder having an average particle size of 5.0±1.0 μm. DMP-30 is tris(dimethylaminomethyl)phenol commercially available from Huntsman Corporation. MHHPA is methylhexahydrophthalic anhydride commercially available from Shangdong QING YANG Corporation. D230 is a polyetheramine commercially available from Huntsman Corporation.

[0070] Example 1 (Ex1) 3.2g NPEL 128, 0.8g HELOXY TM Modifier 48, and 2g of Hypox TMRA840 was introduced into a Speedmixer DC600 and mixed at 2000 rpm for 2 minutes. Then, 4.6 g of BAK-5 and 0.1 g of AEROSIL® R974 were added to the mixer and mixed at 2000 rpm for 3 minutes. Subsequently, 18.4 g of BAK-20 was added to the mixer and mixed at 2000 rpm for 3 minutes. The mixture thus obtained was mixed under vacuum at 2000 rpm for 2 minutes. Next, 0.1 g of DMP 30 and 3.54 g of MHHPA were added to the mixture and mixed. The composition thus obtained was then placed in a haven for curing.

[0071] Example 2 (Ex2) 3.2g NPEL 128, 0.8g HELOXY TM Modifier 48, and 2g of Kane Ace TM MX267 was introduced into a Speedmixer DC600 and mixed at 2000 rpm for 2 minutes. Then, 4.6 g of BAK-5 and 0.1 g of AEROSIL® R974 were added to the mixer and mixed at 2000 rpm for 3 minutes. Subsequently, 18.4 g of BAK-20 was added to the mixer and mixed at 2000 rpm for 3 minutes. The mixture thus obtained was mixed under vacuum at 2000 rpm for 2 minutes. Next, 0.1 g of DMP 30 and 3.74 g of MHHPA were added to the mixture and mixed. The composition thus obtained was then placed in a Haven for curing.

[0072] Example 3 (Ex3) 3.2g NPEL 128, 0.8g HELOXY TM Modifier 48, and 2g of Hypox TMRA840 was introduced into a Speedmixer DC600 and mixed at 2000 rpm for 2 minutes. Then, 4.6 g of BAK-5 and 0.1 g of AEROSIL® R974 were added to the mixer and mixed at 2000 rpm for 3 minutes. Subsequently, 18.4 g of BAH-20H4 was added to the mixer and mixed at 2000 rpm for 3 minutes. The mixture thus obtained was mixed under vacuum at 2000 rpm for 2 minutes. Next, 0.1 g of DMP 30 and 3.54 g of MHHPA were added to the mixture and mixed. The composition thus obtained was then placed in a Haven for curing.

[0073] Example 4 (Ex4) 3.2g NPEL 128, 0.8g HELOXY TM Modifier 48, and 2g of Hypox TM RA840 was introduced into a Speedmixer DC600 and mixed at 2000 rpm for 2 minutes. Then, 4.6 g of BAK-5 and 0.1 g of AEROSIL® R974 were added to the mixer and mixed at 2000 rpm for 3 minutes. Subsequently, 18.4 g of BAK-20 was added to the mixer and mixed at 2000 rpm for 3 minutes. The mixture thus obtained was mixed under vacuum at 2000 rpm for 2 minutes. Next, 0.1 g of DMP 30 and 3.54 g of D230 were added to the mixture and mixed. The composition thus obtained was then placed in a Haven for curing.

[0074] Example 5 (Ex5) 3.2g NPEL 128, 0.8g HELOXY TM Modifier 48, and 2g of Hypox TMRA840 was introduced into a Speedmixer DC600 and mixed at 2000 rpm for 2 minutes. Then, 4.6 g of BAK-5 and 0.1 g of AEROSIL® R974 were added to the mixer and mixed at 2000 rpm for 3 minutes. Subsequently, 18.4 g of BAH-40 was added to the mixer and mixed at 2000 rpm for 3 minutes. The mixture thus obtained was mixed under vacuum at 2000 rpm for 2 minutes. Next, 0.1 g of DMP 30 and 3.54 g of MHHPA were added to the mixture and mixed. The composition thus obtained was then placed in a Haven for curing.

[0075] The components and their amounts in Examples 1 to 5 are shown in Table 1. [Table 1]

[0076] Comparative example 1 (CE1) 3.2g NPEL 128, 0.8g HELOXY TM Modifier 8, and 2g of Hypox TM RA840 was introduced into a Speedmixer DC600 and mixed at 2000 rpm for 2 minutes. Then, 4.6 g of BAK-5 and 0.1 g of AEROSIL® R974 were added to the mixer and mixed at 2000 rpm for 3 minutes. Subsequently, 18.4 g of BAK-20 was added to the mixer and mixed at 2000 rpm for 3 minutes. The mixture thus obtained was mixed under vacuum at 2000 rpm for 2 minutes. Next, 0.1 g of DMP 30 and 3.2 g of MHHPA were added to the mixture and mixed. The composition thus obtained was then placed in a Haven for curing.

[0077] Comparative Example 2 (CE2) 3.2g of NPEL 128, 0.8g of ED523T, and 2g of Hypox TMRA840 was introduced into a Speedmixer DC600 and mixed at 2000 rpm for 2 minutes. Then, 4.6 g of BAK-5 and 0.1 g of AEROSIL® R974 were added to the mixer and mixed at 2000 rpm for 3 minutes. Subsequently, 18.4 g of BAK-20 was added to the mixer and mixed at 2000 rpm for 3 minutes. The mixture thus obtained was mixed under vacuum at 2000 rpm for 2 minutes. Next, 0.1 g of DMP 30 and 3.54 g of MHHPA were added to the mixture and mixed. The composition thus obtained was then placed in a Haven for curing.

[0078] Comparative Example 3 (CE3) 3.2g NPEL 128, 0.8g HELOXY TM Modifier 48 and 2g of Fortegra 202 were added to a Speedmixer DC600 and mixed at 2000 rpm for 2 minutes. 4.6g of BAK-5 and 0.1g of AEROSIL® R974 were then added to the mixer and mixed at 2000 rpm for 3 minutes. 18.4g of BAK-20 was then added to the mixer and mixed at 2000 rpm for 3 minutes. The mixture was mixed under vacuum at 2000 rpm for 2 minutes. 0.1g of DMP 30 and 3.35g of MHHPA were then added to the mixture and mixed. The resulting composition was then placed in a Haven for curing.

[0079] Comparative Example 4 (CE4) 3.2g NPEL 128, 0.8g HELOXY TM Modifier 48, and 2g of Hypox TMRA840 was introduced into a Speedmixer DC600 and mixed at 2000 rpm for 2 minutes. Then, 4.6 g of BAK-5 and 0.1 g of AEROSIL® R974 were added to the mixer and mixed at 2000 rpm for 3 minutes. Then, 18.4 g of SJR-20 was added to the mixer and mixed at 2000 rpm for 3 minutes. The mixture thus obtained was mixed under vacuum at 2000 rpm for 2 minutes. Then, 0.1 g of DMP 30 and 3.54 g of MHHPA were added to the mixture and mixed. The composition thus obtained was then placed in a Haven for curing.

[0080] Comparative Example 5 (CE5) 3.2g NPEL 128, 0.8g HELOXY TM Modifier 48 and 2 g of QS-N12 were added to a Speedmixer DC600 and mixed at 2000 rpm for 2 minutes. Next, 4.6 g of BAK-5 and 0.1 g of AEROSIL® R974 were added to the mixer and mixed at 2000 rpm for 3 minutes. Subsequently, 18.4 g of BAK-20 was added to the mixer and mixed at 2000 rpm for 3 minutes. The resulting mixture was mixed under vacuum at 2000 rpm for 2 minutes. Next, 0.1 g of DMP 30 and 3.54 g of MHHPA were added to the mixture and mixed. The resulting composition was then placed in a Haven for curing.

[0081] Comparative example 6 (CE6) 3.2g NPEL 128, 0.8g HELOXY TMModifier 48 and 2 g of QS-VA-3 were added to a Speedmixer DC600 and mixed at 2000 rpm for 2 minutes. Next, 4.6 g of BAK-5 and 0.1 g of AEROSIL® R974 were added to the mixer and mixed at 2000 rpm for 3 minutes. Subsequently, 18.4 g of BAK-20 was added to the mixer and mixed at 2000 rpm for 3 minutes. The resulting mixture was mixed under vacuum at 2000 rpm for 2 minutes. Next, 0.1 g of DMP 30 and 3.54 g of MHHPA were added to the mixture and mixed. The resulting composition was then placed in a Haven for curing.

[0082] The components and amounts thereof in Comparative Examples 1 to 6 are shown in Table 2. [Table 2]

[0083] Performance evaluation viscosity: The viscosity of the compositions of Examples 1 to 5 and Comparative Examples 1 to 6 was tested using a Rheometer MCR 301 at 25° C. and 5 l / s.

[0084] Thermal Conductivity: The thermal conductivity of the compositions of Examples 1-5 and Comparative Examples 1-6 was tested at 25° C. using an LFA 467 commercially available from NETZSCH according to ASTM E1461 of the American Society for Testing and Materials.

[0085] Lap shear strength: The lap shear strength of the compositions of Examples 1-5 and Comparative Examples 1-6 was tested at 25°C using Al and Al using an Instron 5569 according to ASTM D1002 of the American Society for Testing and Materials.

[0086] Thermal shock resistance: The test was carried out as follows: As shown in Figure 1, a device simulating a motor stator was made using an aluminum lid, a steel ring, and insulating paper; each composition of Examples 1 to 5 and Comparative Examples 1 to 6 was poured into the device until the aluminum lid was no longer visible, and then the device was placed in an oven for curing. The device with the cured product of the composition was then placed in a thermal shock machine for shock cycling at -40°C for 1 hour and 150°C for 1 hour. The shock cycling continued until cracks appeared in the cured product. The thermal shock resistance of the composition was measured by the number of cycles. The higher the number of cycles, the better the thermal shock resistance of the composition.

[0087] The test results of the performance evaluation of the thermally conductive potting compositions of the Examples and Comparative Examples are shown in Tables 3 and 4, respectively.

[0088] [Table 3]

[0089] As shown in Table 3, the thermally conductive potting composition of the present invention had low viscosity and simultaneously exhibited excellent bonding performance and thermal shock resistance.

[0090] [Table 4]

[0091] As shown in Table 4, the comparative composition containing a modified epoxy resin with one epoxy functionality (CE1) or a modified epoxy resin with two epoxy functionality (CE2) exhibited poor thermal shock resistance; the comparative composition containing Fortegra 202 (CE3) or QS-VA-3 (CE6) exhibited poor bonding performance and thermal shock resistance; the comparative composition containing QS-N12 (CE5) exhibited poor bonding performance; and the comparative composition containing SJR-20 (CE4) had such a high viscosity that the potting composition could not be processed. In summary, thermally conductive potting compositions outside the scope of the present invention failed to simultaneously exhibit low viscosity and excellent bonding performance and thermal shock resistance.

[0092] While certain preferred embodiments have been described, many modifications and variations thereto may be made in light of the above teachings. It is therefore to be understood that the invention may be practiced otherwise than as specifically described without departing from the scope of the appended claims.

Claims

1. A) an epoxy resin having a viscosity at 25°C of at least 500 mPa·s; B) a modified epoxy resin having at least three epoxy functional groups and a viscosity at 25°C of at least 10 mPa·s and not more than 1000 mPa·s; C) 20% by weight of which are core-shell nanoparticles having a particle size of 0.01 to 1 μm; D) D1) silane surface-modified spherical alumina having an average particle size of greater than 15 μm and less than or equal to 100 μm; and D2) Thermally conductive powder having an average particle size of more than 0.01 μm and not more than 15 μm a filler comprising: E) Hardener 1. A thermally conductive potting composition comprising:

2. 10. The thermally conductive potting composition of claim 1, wherein the content of component A) is 1 to 40 wt. %, based on the total weight of the composition.

3. 3. The thermally conductive potting composition of claim 1, wherein the content of component B) is 0.1 to 20 wt. %, based on the total weight of the composition.

4. The thermally conductive potting composition of any of claims 1 to 3, wherein component B) is a modified epoxy resin having three epoxy functional groups.

5. The thermally conductive potting composition according to any one of claims 1 to 4, wherein the content of component C) is 1 to 50 wt % based on the total weight of the composition.

6. The thermally conductive potting composition according to any one of claims 1 to 5, wherein the content of component D1) is 30 to 80 wt %, based on the total weight of the composition.

7. The thermally conductive potting composition of any of claims 1 to 6, wherein component D1) contains 0.001 to 5 wt. % of the silane.

8. The thermally conductive potting composition according to any one of claims 1 to 7, wherein the content of component D2) is 5 to 80 wt. % based on the total weight of the composition.

9. The thermally conductive potting composition according to any one of claims 1 to 8, wherein the content of component E) is 1 to 20 wt %, based on the total weight of the composition.

10. The thermally conductive potting composition of any one of claims 1 to 9, further comprising a cure accelerator.

11. 1. A two-component thermally conductive potting composition comprising: Part A is A) an epoxy resin having a viscosity at 25°C of at least 500 mPa·s; B) a modified epoxy resin having at least three epoxy functional groups and a viscosity at 25°C of at least 10 mPa·s and not more than 1000 mPa·s; C) 20% by weight of which are core-shell nanoparticles having a particle size of 0.01 to 1 μm; D) D1) silane surface-modified spherical alumina having an average particle size of greater than 15 μm and less than or equal to 100 μm; and D2) Thermally conductive powder having an average particle size of more than 0.01 μm and not more than 15 μm A filler comprising comprising Part B is E) Hardener 1. A two-component thermally conductive potting composition comprising:

12. Use of the thermally conductive potting composition according to any one of claims 1 to 10 or the two-component thermally conductive potting composition according to claim 11 for new energy vehicles.

13. A new energy vehicle comprising a cured product of the thermally conductive potting composition of any one of claims 1 to 10 or the two-component thermally conductive potting composition of claim 11.

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