WO2016198425A1 - High thermally conductive low pressure mouldable hotmelt - Google Patents

High thermally conductive low pressure mouldable hotmelt Download PDF

Info

Publication number
WO2016198425A1
WO2016198425A1 PCT/EP2016/062972 EP2016062972W WO2016198425A1 WO 2016198425 A1 WO2016198425 A1 WO 2016198425A1 EP 2016062972 W EP2016062972 W EP 2016062972W WO 2016198425 A1 WO2016198425 A1 WO 2016198425A1
Authority
WO
WIPO (PCT)
Prior art keywords
thermally conductive
adhesive composition
μιη
composition according
hotmelt adhesive
Prior art date
Application number
PCT/EP2016/062972
Other languages
French (fr)
Inventor
David Briers
Gunther Dreezen
Jianfen CAI
Callum POOLE
Anthony Chapman
Dale R. Starkey
Original Assignee
Henkel Ag & Co. Kgaa
Henkel IP & Holding GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Henkel Ag & Co. Kgaa, Henkel IP & Holding GmbH filed Critical Henkel Ag & Co. Kgaa
Priority to KR1020177035072A priority Critical patent/KR20180016381A/en
Priority to EP16728671.5A priority patent/EP3303494A1/en
Priority to JP2017563583A priority patent/JP2018522968A/en
Priority to CN201680032339.7A priority patent/CN107667156A/en
Publication of WO2016198425A1 publication Critical patent/WO2016198425A1/en
Priority to US15/830,152 priority patent/US20180094171A1/en

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C35/00—Heating, cooling or curing, e.g. crosslinking or vulcanising; Apparatus therefor
    • B29C35/16—Cooling
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
    • B29C70/68—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts by incorporating or moulding on preformed parts, e.g. inserts or layers, e.g. foam blocks
    • B29C70/70—Completely encapsulating inserts
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
    • B29C70/88—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts characterised primarily by possessing specific properties, e.g. electrically conductive or locally reinforced
    • B29C70/882—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts characterised primarily by possessing specific properties, e.g. electrically conductive or locally reinforced partly or totally electrically conductive, e.g. for EMI shielding
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K3/00—Use of inorganic substances as compounding ingredients
    • C08K3/01—Use of inorganic substances as compounding ingredients characterized by their specific function
    • C08K3/013—Fillers, pigments or reinforcing additives
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K3/00—Use of inorganic substances as compounding ingredients
    • C08K3/18—Oxygen-containing compounds, e.g. metal carbonyls
    • C08K3/20—Oxides; Hydroxides
    • C08K3/22—Oxides; Hydroxides of metals
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K7/00—Use of ingredients characterised by shape
    • C08K7/16—Solid spheres
    • C08K7/18—Solid spheres inorganic
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J11/00—Features of adhesives not provided for in group C09J9/00, e.g. additives
    • C09J11/02—Non-macromolecular additives
    • C09J11/04—Non-macromolecular additives inorganic
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J177/00—Adhesives based on polyamides obtained by reactions forming a carboxylic amide link in the main chain; Adhesives based on derivatives of such polymers
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K7/00—Constructional details common to different types of electric apparatus
    • H05K7/20—Modifications to facilitate cooling, ventilating, or heating
    • H05K7/2039—Modifications to facilitate cooling, ventilating, or heating characterised by the heat transfer by conduction from the heat generating element to a dissipating body
    • H05K7/20436—Inner thermal coupling elements in heat dissipating housings, e.g. protrusions or depressions integrally formed in the housing
    • H05K7/20445—Inner thermal coupling elements in heat dissipating housings, e.g. protrusions or depressions integrally formed in the housing the coupling element being an additional piece, e.g. thermal standoff
    • H05K7/20472—Sheet interfaces
    • H05K7/20481—Sheet interfaces characterised by the material composition exhibiting specific thermal properties
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
    • B29K2077/00—Use of PA, i.e. polyamides, e.g. polyesteramides or derivatives thereof, as moulding material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
    • B29K2105/00—Condition, form or state of moulded material or of the material to be shaped
    • B29K2105/06—Condition, form or state of moulded material or of the material to be shaped containing reinforcements, fillers or inserts
    • B29K2105/16—Fillers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
    • B29L2031/00—Other particular articles
    • B29L2031/34—Electrical apparatus, e.g. sparking plugs or parts thereof
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K3/00—Use of inorganic substances as compounding ingredients
    • C08K3/18—Oxygen-containing compounds, e.g. metal carbonyls
    • C08K3/20—Oxides; Hydroxides
    • C08K3/22—Oxides; Hydroxides of metals
    • C08K2003/2227—Oxides; Hydroxides of metals of aluminium
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K2201/00—Specific properties of additives
    • C08K2201/001—Conductive additives
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K2201/00—Specific properties of additives
    • C08K2201/002—Physical properties
    • C08K2201/005—Additives being defined by their particle size in general
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K2201/00—Specific properties of additives
    • C08K2201/016—Additives defined by their aspect ratio
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J2203/00—Applications of adhesives in processes or use of adhesives in the form of films or foils
    • C09J2203/326—Applications of adhesives in processes or use of adhesives in the form of films or foils for bonding electronic components such as wafers, chips or semiconductors
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J2301/00—Additional features of adhesives in the form of films or foils
    • C09J2301/30—Additional features of adhesives in the form of films or foils characterized by the chemical, physicochemical or physical properties of the adhesive or the carrier
    • C09J2301/304—Additional features of adhesives in the form of films or foils characterized by the chemical, physicochemical or physical properties of the adhesive or the carrier the adhesive being heat-activatable, i.e. not tacky at temperatures inferior to 30°C
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J2301/00—Additional features of adhesives in the form of films or foils
    • C09J2301/30—Additional features of adhesives in the form of films or foils characterized by the chemical, physicochemical or physical properties of the adhesive or the carrier
    • C09J2301/312—Additional features of adhesives in the form of films or foils characterized by the chemical, physicochemical or physical properties of the adhesive or the carrier parameters being the characterizing feature
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J2301/00—Additional features of adhesives in the form of films or foils
    • C09J2301/30—Additional features of adhesives in the form of films or foils characterized by the chemical, physicochemical or physical properties of the adhesive or the carrier
    • C09J2301/314—Additional features of adhesives in the form of films or foils characterized by the chemical, physicochemical or physical properties of the adhesive or the carrier the adhesive layer and/or the carrier being conductive
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J2400/00—Presence of inorganic and organic materials
    • C09J2400/10—Presence of inorganic materials
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J2477/00—Presence of polyamide

Definitions

  • the present invention relates to thermally conductive hotmelt adhesives, with improved thermal conductivity, uses thereof and methods for the encapsulating heat generating devices by using said thermally conductive hotmelt adhesive compositions.
  • Adhesives which are thermally conductive are employed in several applications where a component has to be fixed upon a structure and where heat has to be deflected from the component. Many applications are therefore in the electronic components in heat exchangers, mainly encapsulates to encapsulate heat generating devices.
  • composition increases, the flowability of the composition decreases at given
  • the current process to encapsulate the heat generating devices widely uses liquid thermoset materials containing fillers in a certain percentage to enable the required thermal conductivity.
  • the current process involves mixing liquid thermoset materials and fillers together followed by potting into the package.
  • the potting step often done under vacuum to ensure sufficient degassing to avoid voids.
  • a cure schedule has to be done to harden the liquid into a thermally conductive thermoset. Such a cure schedule can take up to several hours ranging from 0.5 hours up to five or more hours.
  • the present invention relates to a thermally conductive hotmelt adhesive composition
  • a thermally conductive hotmelt adhesive composition comprising: a) at least one thermally conductive filler, wherein said at least one thermally conductive filler contains a mixture of flake particles and first spherical particles in a ratio of 10 : 1 , and wherein said flake particles have an aspect ratio of 1.25 to 7, or said at least one thermally conductive filler contains a mixture of second spherical particles having an average particle size from 35 - 55 ⁇ and third spherical particles having an average particle size from 2 - 15 ⁇ in a ratio of 10 : 1 , and wherein said at least one thermally conductive filler is selected from the group consisting of tin oxide, indium oxide, antimony oxide, aluminum oxide, titanium oxide, iron oxide, magnesium oxide, zinc oxide, oxides of rare earth metals; alkaline and alkaline earth metal sulphates; chalk; boron nitride; alkaline silicate
  • the present invention also relates to a method of encapsulating a heat generating device comprising steps of: a) applying the thermally conductive hotmelt adhesive composition according to the to the surface of said heat generating device by low pressure moulding; b) cooling; and c) removing from the mould.
  • the present invention relates to use of the thermally conductive hotmelt adhesive composition according to the present invention in pipes, preferably cooling coils; in electronic components, preferably in light emitting devices, computer devices, mobile phones, tablets, touch screens, automotive technology hifi systems, and audio systems; in joints between heat pipes and water tanks in solar heated heating; in fuel cells and wind turbines; in the manufacture of computer chips; in light devices; batteries; in housings; coolers; heat exchanging devices; wires; cables; heating wires; refrigerators; dishwashers; air conditionings; accumulators; transformers; lasers; functional clothing; car seats; medical devices; fire protection; electric motors; planes; and trains; as a filament in 3D printing material.
  • the present invention also encompasses use of the thermally conductive hotmelt adhesive composition according to the present invention as a potting or moulded encapsulant for encapsulating heat generating devices Detailed description of the invention
  • a molecular weight of a polymer refers to the average number molecular weight M n , if not explicitly stated otherwise.
  • the number average molecular weight M n of a polymer can, for example, be determined by gel permeation chromatography according to DIN 55672-1 :2007-08 with THF as the eluent. If not stated otherwise, all given molecular weights are those determined by GPC, calibrated with polystyrene standards.
  • the weight average molecular weight M w can also be determined by GPC, as described for M n .
  • Aspect ratio refers to an average aspect ratio of 50, preferably 100, particles of the respective filler as measured in accordance with the measurement method described below.
  • the present invention is based on the inventor's surprising finding that incorporation of a combination of different shaped thermally conductive filler materials, more particularly mixture of first spherical filler material and flake filler material or mixture of second spherical filler material and third spherical filler material, into a hotmelt adhesive composition can on the one hand provide for a synergistic increase in thermal conductivity, while maintaining desirable values for viscosity and retaining adhesive and mechanical properties without filler settling.
  • thermally conductive hotmelt adhesive needs to have adhesive strength high enough for bonding two substrates, such as metals and unpolar polymers or metals and metals. Adhesives need also to provide mechanical resistance. In addition, adhesives need to have the desired high thermal conductivity to allow efficient heat transfer. Furthermore, the viscosity of the hotmelt adhesive composition according to the present invention must be on desired level in order it to be suitable for low pressure moulding.
  • the hotmelt adhesive according to the present invention provides the possibility for a fast and clean, high volume process to encapsulate electronic parts with a heat dissipating layer.
  • the hotmelt adhesive according to the present invention is an alternative for current thermally conductive, thermoset potting materials.
  • the adhesive hotmelt compositions according to the present invention therefore have to include adhesive agents that meet the above adhesive requirements, and at the same time materials that provide the improved thermal conductivity.
  • the present invention provides a thermally conductive hotmelt adhesive composition
  • a thermally conductive hotmelt adhesive composition comprising: a) at least one thermally conductive filler, wherein said at least one thermally conductive filler contains a mixture of flake particles and first spherical particles in a ratio of 10 : 1 , and wherein said flake particles have an aspect ratio of 1.25 to 7, or said at least one thermally conductive filler contains a mixture of second spherical particles having an average particle size from 35 - 55 ⁇ and third spherical particles having an average particle size from 2 - 15 ⁇ in a ratio of 10 : 1 , and wherein said at least one thermally conductive filler is selected from the group consisting of tin oxide, indium oxide, antimony oxide, aluminum oxide, titanium oxide, iron oxide, magnesium oxide, zinc oxide, oxides of rare earth metals; alkaline and alkaline earth metal sulphates; chalk; boron nitride; alkaline silicate, si
  • compositions according to the present invention comprises at least one thermally conductive filler.
  • Suitable thermally conductive filler is selected from the group consisting of tin oxide, indium oxide, antimony oxide, aluminum oxide, titanium oxide, iron oxide, magnesium oxide, zinc oxide, oxides of rare earth metals; alkaline and alkaline earth metal sulphates; chalk; boron nitride; alkaline silicate, silica, iron, copper, aluminum, zinc, gold, silver and tin, alkaline and alkaline earth metal halides; alkaline and alkaline earth metal phosphates; and mixtures thereof.
  • said thermally conductive filler is boron nitride or aluminum oxide, more preferably said thermally conductive filler is aluminum oxide.
  • Suitable thermally conductive filler for use in the present invention contains a mixture of flake particles and first spherical particles or a mixture of second spherical particles and third spherical particles.
  • a mixtures of flake particles and spherical particles or a mixture of second spherical particles and third spherical particles are preferred, because the mixture provides ideal packing density, resulting in low viscosity adhesive hotmelt composition having a high thermal conductivity. Relative low viscosity adhesive hotmelt composition is preferred for the low pressure moulding.
  • the mixture of flake particles and first spherical particles reduce the costs of the adhesive hotmelt composition.
  • Suitable thermally conductive filler for use in the present invention contains a mixture of flake particles and first spherical particles in a ratio of 10 : 1 , preferably from 4.5 : 1 to 6.5 : 1 , and preferably from 5 : 1 to 6 : 1.
  • suitable thermally conductive filler for use in the present invention contains a mixture of second spherical particles and third spherical particles in a ratio of 10 : 1 , preferably from 4.5 : 1 to 6.5 : 1 , and preferably from 5 : 1 to 6 : 1.
  • the packing density may be insufficient to provide the needed thermal conductivity.
  • Such a high ratio may also increase the viscosity of the composition too high.
  • Suitable flake particles for use in the present invention have an aspect ratio from 1.25 to 7, preferably from 1.5 to 5, more preferably from 1.75 to 4 and most preferably from 2 to 3.
  • Aspect ratio relates to the ratio between sizes in different dimensions of a three-dimensional object, more particularly the ratio of the longest side to the shortest side, for example height to width.
  • Ball-shaped or spherical particles therefore have an aspect ratio of about 1
  • fibres, needles or flakes have aspect ratio of more than 1 , as they have in relation to their length or length and width a comparable small diameter or thickness.
  • the aspect ratio can be determined by scanning electron microscopy (SEM) measurements.
  • SEM scanning electron microscopy
  • the magnification is between x250 to x1000 and the aspect ratio is a mean value obtained by measuring the width and the length of at least 50, preferably 100 particles in the picture.
  • the SEM measurements can be obtained with a tilt angle of 45° of the sample.
  • Suitable flake particles for use in the present invention have an average particle size (dso) from 30 to 60 ⁇ , preferably from 35 to 50 ⁇ , and more preferably from 42 to 47 ⁇ and most preferably from 44 to 46 ⁇ .
  • the particle size can, for example, be determined by laser diffraction method according to ISO 13320:2009.
  • Suitable spherical particles for use in the present invention have aspect ratio of 1.
  • the aspect ratio is measured according to the test method described above.
  • Suitable first spherical particles for use in the present invention have an average particle size (dso) from 3 to 50 ⁇ , preferably from 4 to 48 ⁇ , and more preferably from 5 to 45 ⁇ .
  • the particle size can, for example, be determined by laser diffraction method according to ISO 13320:2009.
  • Suitable second spherical particles for use in the present invention have an average particle size (dso) from 40 to 50 ⁇ , and preferably from 42 to 48 ⁇ .
  • the particle size can, for example, be determined by laser diffraction method according to ISO 13320:2009.
  • Suitable third spherical particles for use in the present invention have an average particle size (dso) from 2 to 10 ⁇ , preferably from 3 to 8 ⁇ , and more preferably from 4 to 6 ⁇ .
  • the particle size can, for example, be determined by laser diffraction method according to ISO 13320:2009.
  • a thermally conductive hotmelt adhesive composition according to the present invention comprises a thermally conductive filler from 50 to 80 % by weight of the total weight of the composition, preferably from 60 to 80%. If the quantity of the thermally conductive filler is above 80%, the viscosity of the hotmelt adhesive becomes too high to mould. On the other hand, if the quantity of the thermally conductive filler is less 50%, the thermal conductivity of the adhesive composition is too low.
  • the thermally conductive filler is aluminium oxide, mixture of flake aluminium oxide particles and first spherical aluminium oxide particles in a ratio of 10 : 1.
  • the flake shape filler particle has an aspect ratio from 1.25 to 7 and an average particle size (dso) from 30 to 60 ⁇
  • the spherical filler particle has an aspect ratio of 1 and an average particle size (dso) from 3 to 50 ⁇ .
  • the thermally conductive filler is aluminium oxide, mixture of flake aluminium oxide particles and first spherical aluminium oxide particles in a ratio of 10 : 1.
  • the flake shape filler particle has an aspect ratio from 1.5 to 5 and an average particle size (dso) from 30 to 60 ⁇ , whereas, the spherical filler particle has an aspect ratio of 1 and an average particle size (dso) from 3 to 50 ⁇ .
  • the thermally conductive filler is aluminium oxide, mixture of flake aluminium oxide particles and first spherical aluminium oxide particles in a ratio from 4.5 : 1 to 6.5 : 1.
  • the flake shape filler particle has an aspect ratio from 1.75 to 4 and an average particle size (dso) from 35 to 50 ⁇
  • the spherical filler particle has an aspect ratio of 1 and an average particle size (dso) from 4 to 48 ⁇ .
  • the thermally conductive filler is aluminium oxide, mixture of flake aluminium oxide particles and first spherical aluminium oxide particles in a ratio from 5 : 1 to 6 : 1.
  • the flake shape filler particle has an aspect ratio from 2 to 3 and an average particle size (dso) from 42 to 47 ⁇
  • the spherical filler particle has an aspect ratio of 1 and an average particle size (dso) from 5 to 45 ⁇ .
  • the thermally conductive filler is aluminium oxide, mixture of flake aluminium oxide particles and first spherical aluminium oxide particles in a ratio from 5 : 1 to 6 : 1.
  • the flake shape filler particle has an aspect ratio from 2 to 3 and an average particle size (dso) from 44 to 46 ⁇ ⁇
  • the spherical filler particle has an aspect ratio of 1 and an average particle size (dso) from 5 to 45 ⁇ .
  • the thermally conductive filler is aluminium oxide, mixture of second spherical aluminium oxide particles and third spherical aluminium oxide particles in a ratio of 10 : 1.
  • the second spherical filler has an average particle size (dso) from 35 to 55 ⁇
  • third spherical filler particle has an average particle size (dso) from 2 to 15 ⁇ .
  • the thermally conductive filler is aluminium oxide, mixture of second spherical aluminium oxide particles and third spherical aluminium oxide particles in a ratio from 4.5 : 1 to 6.5 : 1.
  • second spherical filler particle has an average particle size (dso) from 40 to 50 ⁇
  • third spherical filler particle has an average particle size (dso) from 2 to 10 ⁇ .
  • the thermally conductive filler is aluminium oxide, mixture of second spherical aluminium oxide particles and third spherical aluminium oxide particles in a ratio from 5 : 1 to 6 : 1.
  • second spherical filler particle has an average particle size (dso) from 42 to 48 ⁇
  • third spherical filler has an average particle size (dso) from 3 to 8 ⁇ .
  • the thermally conductive filler is aluminium oxide, mixture of second spherical aluminium oxide particles and third spherical aluminium oxide particles in a ratio from 5 : 1 to 6 : 1.
  • second spherical filler particle has an average particle size (dso) from 42 to 48 ⁇
  • third spherical filler has an average particle size (dso) from 4 to 6 ⁇ .
  • a thermally conductive hotmelt adhesive composition according to the present invention comprises a (co)polymer as binding agent.
  • the term (co)polymer includes homopolymers, copolymers, block copolymers and terpolymers.
  • thermoplastic polyamides preferably thermoplastic polyamides, polyolefins, preferably alpha-olefins, more preferably butyl rubber or polybutene, poly(meth)acrylates, polystyrene, polyurethanes, preferably thermoplastic polyurethane, polyesters, ethylene copolymers, ethylene vinyl copolymers, styrenic block copolymers, preferably styrene-butadiene (SB), styrene-ethylene-butadiene- styrene (SEBS), styrene-isoprene (SI), styrene-isoprene-styrene (SIS), styrene- butadiene-styrene (SBS),
  • (co)polymers are selected from the group consisting of polyamide, thermoplastic polyamide or copolyamide, preferably polyamide or thermoplastic polyamide. These (co)polymers are preferred because they are non-toxic and safer to use compared to typical potting solutions, which contain for example amines
  • thermosets amine/epoxy thermosets
  • isocyanates polyurethane thermosets
  • a thermally conductive hotmelt adhesive composition according to the present invention may further comprise one or more additional additives, preferably selected from the group consisting of plasticizers, dyes, waxes, antioxidants, surfactants, stabilizers, rheology modifiers, cross-linking agents, and combinations thereof.
  • a thermally conductive hotmelt adhesive composition according to the present invention may further comprise waxes.
  • waxes that can be used include, without limitation, polar waxes selected from functionalized polyolefins with a molecular weight MN range as determined by GPC between about 4000 and 80000 and based on ethylene and/or propylene with acrylic acid, methacrylic acid, C1-4 alkyl esters of (meth)acrylic acid, itaconic acid, fumaric acid, vinyl acetate, carbon monoxide, and in particular maleic acid and mixtures thereof.
  • Preferred are ethylene, propylene or ethylene-propylene (co)polymers grafted or copolymerized with polar monomers with saponification and acid values, respectively, between 2 and 50 mg KOH/g.
  • Saponification and acid values can be determined by titration.
  • the rheology of the composition according to the present invention and/or the mechanical properties of the glue joint can be adjusted by the addition of so-called extender oils, i.e. aliphatic, aromatic or naphthenic oils, low molecular weight polybutenes or polyisobutylenes.
  • extender oils i.e. aliphatic, aromatic or naphthenic oils, low molecular weight polybutenes or polyisobutylenes.
  • poly-alpha-olefins which are liquid at 25°C can be employed which are commercially available for example under the tradename Synfluid PAO.
  • conventional plasticizers such as dialkyl or alkylaryl esters of phthalic acid or dialkyl esters of aliphatic dicarboxylic acids can be used, optionally in admixture with the afore-mentioned extender oils.
  • a thermally conductive hotmelt adhesive composition according to the present invention may comprise a plasticizer or an extender oil from 0 to 10 % of by weight of the total weight of the composition.
  • Suitable stabilizers that can be used in the compositions according to the present invention include, without limitation, 2-(hydroxyphenyl)-benzotriazole, 2- hydroxybenzophenone, alkyl-2-cyano-3-phenylcinnamate, phenylsalicylate or 1 ,3,5- tris(2'-hydroxyphenyl)triazine.
  • Suitable antioxidants include, without limitation, those commercially available under the trademark name Irganox® (BASF, SE).
  • distearyl-pentaerythritdiphosphate compounds octadecyl esters of 3,5-bis(1 ,1 - dimethylethyl)-4-hydroxybenzylpropanoic acid (Irganox® 1076), 2,4-bis(n-octylthio)-6- (4-hydroxy-3,5-di-tert-butylanilino)-1 ,3,5-triazine (Irganox® 565), 2-tert-butyl-6-(3-tert- butyl-2-hydroxy-5-methylbenzyl)-4-methylphenylacrylate, phosphite antioxidants, such as tris(nonylphenyl)phosphite (TNPP), tris(mono-nonylphenyl)phosphite, and tris(di- nonylphenyl)phosphite, bis(2,4-di-tert-butylphenyl)p
  • a thermally conductive hotmelt adhesive composition according to the present invention may comprise a stabilizer from 0 to 5 % of by weight of the total weight of the composition.
  • a thermally conductive hotmelt adhesive composition according to the present invention have a thermal conductivity of at least 0.500 W/(m * K), preferably at least 0.700 W/(m * K), more preferably at least 0.750 W/(m * K), most preferably at least 0.800 W/(m * K).
  • the thermal conductivity can be determined by using Holometric's laser flash according to ASTM1461.
  • the adhesive compositions while having a high thermal conductivity, the adhesive compositions still retain a viscosity that allows simple application on to the substrate.
  • the viscosity of the thermally conductive hotmelt adhesive according to the present invention is meant viscosity in the molten state. More particularly, in preferred embodiments, the viscosity of the adhesive composition is from 500 to 50,000 mPas, preferably from 5,000 to 25,000 mPas, more preferably from 5,000 to 15,000 mPas.
  • the viscosity can be determined according to ASTM D 3236, except that the temperature was 210°C or 240 °C instead of 175°C.
  • Low viscosity enables a low pressure moulding, meaning that the moulding can be done between 2 and 30 bar. This leads to the use of aluminium moulds instead of steel moulds, which decrease the price of the process.
  • low pressure allows faster cycle times on production (10-50 seconds).
  • Lower pressure also increase the productivity of the process, because it allows higher output compared to liquid, thermoset potting solutions (reduced number of process steps).
  • Lower pressure also causes less damage to the electronic components.
  • a thermally conductive hotmelt adhesive composition according to the present invention can be produced by conventional means. Preferred methods include the manufacture by mixers, for example planetary mixer, planetary dissolver, kneader, internal mixer and extruder.
  • a thermally conductive hotmelt adhesive composition according to the present invention can be produced by melting first the (co)polymer and optionally additive(s) and then mixing until a homogenous mixture is obtain. Subsequently, the filler particles are added into the mixture in any order. The final composition is then thoroughly mixed and allowed to cool to a room temperature.
  • the thermally conductive hotmelt adhesive composition according to the present invention is intended to encapsulate heat generating devices, such as printed circuit boards to provide better heat dissipation.
  • the encapsulates can be prepared via low pressure moulding.
  • the invention is directed to a method of encapsulating a heat generating device comprising steps of: a) applying by using injection moulding the thermally conductive hotmelt adhesive composition according to the present invention to the surface of said heat generating device by low pressure moulding;
  • the liquefied thermally conductive hotmelt adhesive composition is injected at temperature of 210°C and under low pressure.
  • the thermally conductive hotmelt adhesive composition according to the present invention can be applied using low pressure injection moulding instead of the typical potting process. Low pressure can be used, between 2 and 30 bar.
  • the hotmelt adhesive according to the present invention also enables fast curing cycle times from 10 to 50 seconds instead of prolonged curing cycles.
  • the hotmelt adhesive according to the present invention provides clean and simple process, having no need to mix two components or perform the process under vacuum.
  • the process according to the present invention requires less energy, because the heat curing step has been eliminated.
  • thermally conductive hotmelt adhesive composition according to the present invention can also be used in the gluing of components of the electronic devices together e.g. circuit boards, electronic components, sensors and control systems.
  • the present invention also covers method for bonding two substrates and for producing an article of manufacture by bonding two substrates.
  • the thermally conductive hotmelt adhesive composition according to the present invention is applied in molten state onto the substrate surface, for example by a roll coating or by bead application.
  • the substrate surface with the adhesive is then pressed onto the other substrate to be bonded.
  • the substrate may include metal plates.
  • a thermally conductive hotmelt adhesive composition according to the present invention may therefore be used to bond metal plating to a plastic or metal substrate. In these applications the thermal conductivity of the adhesive is of particular importance.
  • the invention is directed to a method of manufacturing an article comprising at least two bonded substrates, comprising steps of:
  • steps (a) and (b) may be repeated to bond a third or further substrate to the already bonded substrates.
  • the method would comprise further step (c) optionally repeating steps (a) and (b) with a third or further substrate to be bonded.
  • the adhesive compositions described herein can be used in various fields, the manufacture of electronic devices. More specifically, they can be used in the
  • pipes preferably cooling coils
  • electronic components preferably in light emitting devices, computer devices, mobile phones, tablets, touch screens, and audio systems
  • automotive technology in joints between heat pipes and water tanks in solar heated heating; in fuel cells and wind turbines; in the manufacture of computer chips; in light devices; batteries; in housings; coolers; heat exchanging devices; wires, such as heating wires; cables; refrigerators; dishwashers; air
  • conditionings accumulators; transformers; lasers; functional clothing; car seats; medical devices; fire protection; electric motors; planes; and trains; and as a filament in 3D printing material.
  • the thermally conductive hotmelt adhesive composition according to the present invention can be used as a potting or moulded encapsulant to encapsulate heat generating devices such as printed circuit boards to provide improved heat dissipation.
  • compositions first the (co)polymer and optionally additive(s) were heated until the (co)polymer is molten and then mixed until a homogenous phase is obtain. To this phase, the fillers are subsequently given in any order. The final composition is then thoroughly mixed and allowed to cool to room temperature.
  • Polyamide 1 is Technomelt OM673 from Henkel; Spherical alumina 1 is DAW/DAM-12 from Denka; Spherical alumina 2 is DAW/DAM-05 from Denka; Spherical alumina 3 is DAW/DAM-50 from Denka; Spherical alumina 4 is DAW/DAM-45 from Denka; Tabular alumina is Tabular alumina T60/T64 from Almatis.

Abstract

The present invention relates to hotmelt adhesives with improved thermal conductivity, uses thereof. The adhesive composition of the present invention comprise at least one (co)polymer binder and at least one filler, as defined herein. The thermally conductive hotmelt adhesive composition according to the present invention is also intended to encapsulate heat generating devices such as printed circuit boards to provide better heat dissipation.

Description

High thermally conductive low pressure mouldable hotmelt
Technical field
[001] The present invention relates to thermally conductive hotmelt adhesives, with improved thermal conductivity, uses thereof and methods for the encapsulating heat generating devices by using said thermally conductive hotmelt adhesive compositions.
Background of the invention
[002] Adhesives, which are thermally conductive are employed in several applications where a component has to be fixed upon a structure and where heat has to be deflected from the component. Many applications are therefore in the electronic components in heat exchangers, mainly encapsulates to encapsulate heat generating devices.
[003] Materials used in conjunction with electronic applications face challenges, mainly due their poor thermal properties, too high viscosity or poor filler stability. Material having too high viscosity is not suitable for low-pressure moulding, which is preferred moulding method for electronic components. Low pressure moulding is preferred because it causes less damage to the electronic components. Material with high viscosity may have issues with filler settling. In addition, when viscosity of the
composition increases, the flowability of the composition decreases at given
temperature, and pressure slows down the process.
[004] The current process to encapsulate the heat generating devices widely uses liquid thermoset materials containing fillers in a certain percentage to enable the required thermal conductivity. The current process involves mixing liquid thermoset materials and fillers together followed by potting into the package. The potting step often done under vacuum to ensure sufficient degassing to avoid voids. To finish the process, a cure schedule has to be done to harden the liquid into a thermally conductive thermoset. Such a cure schedule can take up to several hours ranging from 0.5 hours up to five or more hours.
[005] Alternatively, one component materials have also been developed to eliminate the mixing step from the above process. However, such materials usually need cold storage as well as a vacuum and a prolonged curing process.
[006] An attempt to meet these challenges in the past has been to provide thermally conductive adhesive compositions changes in the resin and filler materials. For example polyamides and polyurethanes have been used in the combination with various thermally conductive filler materials.
[007] However, there is still a need in the art for adhesive hotmelt compositions that exhibit excellent thermal conductivity, while the negative effects on viscosity, filler stability and mechanical properties are minimized. While the composition would also provide the possibility for a fast and clean, high volume process to encapsulate electronic parts with a heat dissipating layer.
Summary of the invention
[008] The present invention relates to a thermally conductive hotmelt adhesive composition comprising: a) at least one thermally conductive filler, wherein said at least one thermally conductive filler contains a mixture of flake particles and first spherical particles in a ratio of 10 : 1 , and wherein said flake particles have an aspect ratio of 1.25 to 7, or said at least one thermally conductive filler contains a mixture of second spherical particles having an average particle size from 35 - 55 μιη and third spherical particles having an average particle size from 2 - 15 μιη in a ratio of 10 : 1 , and wherein said at least one thermally conductive filler is selected from the group consisting of tin oxide, indium oxide, antimony oxide, aluminum oxide, titanium oxide, iron oxide, magnesium oxide, zinc oxide, oxides of rare earth metals; alkaline and alkaline earth metal sulphates; chalk; boron nitride; alkaline silicate, silica, iron, copper, aluminum, zinc, gold, silver and tin, alkaline and alkaline earth metal halides; alkaline and alkaline earth metal phosphates; and mixtures thereof; and b) at least one (co)polymer selected from the group consisting of polyamides, thermoplastic polyamides, copolyamides, butyl rubber, polybutene, poly(meth)acrylates, polystyrene, polyurethanes, thermoplastic polyurethane, polyesters, ethylene copolymers, ethylene vinyl copolymers, styrene- butadiene (SB), styrene-ethylene-butadiene-styrene (SEBS), styrene-isoprene (SI), styrene-isoprene-styrene (SIS), styrene-butadiene-styrene (SBS), styrene-isoprene- butadiene (SIB), styrene-isoprene-butadiene-styrene (SIBS), polylactic acid (PLA), silicones, epoxies, polyols and mixtures thereof.
[009] The present invention also relates to a method of encapsulating a heat generating device comprising steps of: a) applying the thermally conductive hotmelt adhesive composition according to the to the surface of said heat generating device by low pressure moulding; b) cooling; and c) removing from the mould.
[010] In addition the present invention relates to use of the thermally conductive hotmelt adhesive composition according to the present invention in pipes, preferably cooling coils; in electronic components, preferably in light emitting devices, computer devices, mobile phones, tablets, touch screens, automotive technology hifi systems, and audio systems; in joints between heat pipes and water tanks in solar heated heating; in fuel cells and wind turbines; in the manufacture of computer chips; in light devices; batteries; in housings; coolers; heat exchanging devices; wires; cables; heating wires; refrigerators; dishwashers; air conditionings; accumulators; transformers; lasers; functional clothing; car seats; medical devices; fire protection; electric motors; planes; and trains; as a filament in 3D printing material.
[011] The present invention also encompasses use of the thermally conductive hotmelt adhesive composition according to the present invention as a potting or moulded encapsulant for encapsulating heat generating devices Detailed description of the invention
[012] In the following passages the present invention is described in more detail. Each aspect so described may be combined with any other aspect or aspects unless clearly indicated to the contrary. In particular, any feature indicated as being preferred or advantageous may be combined with any other feature or features indicated as being preferred or advantageous.
[013] In the context of the present invention, the terms used are to be construed in accordance with the following definitions, unless a context dictates otherwise.
[014] As used herein, the singular forms "a", "an" and "the" include both singular and plural referents unless the context clearly dictates otherwise.
[015] The terms "comprising", "comprises" and "comprised of" as used herein are synonymous with "including", "includes" or "containing", "contains", and are inclusive or open-ended and do not exclude additional, non-recited members, elements or method steps.
[016] The recitation of numerical end points includes all numbers and fractions subsumed within the respective ranges, as well as the recited end points.
[017] When an amount, a concentration or other values or parameters is/are expressed in form of a range, a preferable range, or a preferable upper limit value and a preferable lower limit value, it should be understood as that any ranges obtained by combining any upper limit or preferable value with any lower limit or preferable value are specifically disclosed, without considering whether the obtained ranges are clearly mentioned in the context.
[018] All references cited in the present specification are hereby incorporated by reference in their entirety. [019] Unless otherwise defined, all terms used in the disclosing the invention, including technical and scientific terms, have the meaning as commonly understood by one of the ordinary skill in the art to which this invention belongs to. By means of further guidance, term definitions are included to better appreciate the teaching of the present invention.
[020] If reference is made herein to a molecular weight of a polymer, this reference refers to the average number molecular weight Mn, if not explicitly stated otherwise. The number average molecular weight Mn of a polymer can, for example, be determined by gel permeation chromatography according to DIN 55672-1 :2007-08 with THF as the eluent. If not stated otherwise, all given molecular weights are those determined by GPC, calibrated with polystyrene standards. The weight average molecular weight Mw can also be determined by GPC, as described for Mn.
[021] "Aspect ratio" as employed herein refers to an average aspect ratio of 50, preferably 100, particles of the respective filler as measured in accordance with the measurement method described below.
[022] The present invention is based on the inventor's surprising finding that incorporation of a combination of different shaped thermally conductive filler materials, more particularly mixture of first spherical filler material and flake filler material or mixture of second spherical filler material and third spherical filler material, into a hotmelt adhesive composition can on the one hand provide for a synergistic increase in thermal conductivity, while maintaining desirable values for viscosity and retaining adhesive and mechanical properties without filler settling.
[023] The adhesive compositions described herein are suitable as a thermally conductive hotmelt adhesive composition by virtue of the specific filler combination used. [024] Thermally conductive hotmelt adhesive according to the present invention needs to have adhesive strength high enough for bonding two substrates, such as metals and unpolar polymers or metals and metals. Adhesives need also to provide mechanical resistance. In addition, adhesives need to have the desired high thermal conductivity to allow efficient heat transfer. Furthermore, the viscosity of the hotmelt adhesive composition according to the present invention must be on desired level in order it to be suitable for low pressure moulding.
[025] The hotmelt adhesive according to the present invention provides the possibility for a fast and clean, high volume process to encapsulate electronic parts with a heat dissipating layer. The hotmelt adhesive according to the present invention is an alternative for current thermally conductive, thermoset potting materials.
[026] The adhesive hotmelt compositions according to the present invention therefore have to include adhesive agents that meet the above adhesive requirements, and at the same time materials that provide the improved thermal conductivity.
[027] The present invention provides a thermally conductive hotmelt adhesive composition comprising: a) at least one thermally conductive filler, wherein said at least one thermally conductive filler contains a mixture of flake particles and first spherical particles in a ratio of 10 : 1 , and wherein said flake particles have an aspect ratio of 1.25 to 7, or said at least one thermally conductive filler contains a mixture of second spherical particles having an average particle size from 35 - 55 μιη and third spherical particles having an average particle size from 2 - 15 μιη in a ratio of 10 : 1 , and wherein said at least one thermally conductive filler is selected from the group consisting of tin oxide, indium oxide, antimony oxide, aluminum oxide, titanium oxide, iron oxide, magnesium oxide, zinc oxide, oxides of rare earth metals; alkaline and alkaline earth metal sulphates; chalk; boron nitride; alkaline silicate, silica, iron, copper, aluminum, zinc, gold, silver and tin, alkaline and alkaline earth metal halides; alkaline and alkaline earth metal phosphates; and mixtures thereof; and b) at least one (co)polymer selected from the group consisting of polyamides, thermoplastic polyamides, copolyamides, butyl rubber, polybutene, poly(meth)acrylates, polystyrene, polyurethanes, thermoplastic polyurethane, polyesters, ethylene copolymers, ethylene vinyl copolymers, styrene- butadiene (SB), styrene-ethylene-butadiene-styrene (SEBS), styrene-isoprene (SI), styrene-isoprene-styrene (SIS), styrene-butadiene-styrene (SBS), styrene-isoprene- butadiene (SIB), styrene-isoprene-butadiene-styrene (SIBS), polylactic acid (PLA), silicones, epoxies, polyols and mixtures thereof.
[028] The compositions according to the present invention comprises at least one thermally conductive filler. Suitable thermally conductive filler is selected from the group consisting of tin oxide, indium oxide, antimony oxide, aluminum oxide, titanium oxide, iron oxide, magnesium oxide, zinc oxide, oxides of rare earth metals; alkaline and alkaline earth metal sulphates; chalk; boron nitride; alkaline silicate, silica, iron, copper, aluminum, zinc, gold, silver and tin, alkaline and alkaline earth metal halides; alkaline and alkaline earth metal phosphates; and mixtures thereof. Preferably, said thermally conductive filler is boron nitride or aluminum oxide, more preferably said thermally conductive filler is aluminum oxide.
[029] Suitable thermally conductive filler for use in the present invention contains a mixture of flake particles and first spherical particles or a mixture of second spherical particles and third spherical particles. A mixtures of flake particles and spherical particles or a mixture of second spherical particles and third spherical particles are preferred, because the mixture provides ideal packing density, resulting in low viscosity adhesive hotmelt composition having a high thermal conductivity. Relative low viscosity adhesive hotmelt composition is preferred for the low pressure moulding. Also the mixture of flake particles and first spherical particles reduce the costs of the adhesive hotmelt composition. [030] Suitable thermally conductive filler for use in the present invention contains a mixture of flake particles and first spherical particles in a ratio of 10 : 1 , preferably from 4.5 : 1 to 6.5 : 1 , and preferably from 5 : 1 to 6 : 1.
[031] Alternatively, suitable thermally conductive filler for use in the present invention contains a mixture of second spherical particles and third spherical particles in a ratio of 10 : 1 , preferably from 4.5 : 1 to 6.5 : 1 , and preferably from 5 : 1 to 6 : 1.
[032] If the ratio is too high, for example 25:1 or 1 :25, the packing density may be insufficient to provide the needed thermal conductivity. Such a high ratio may also increase the viscosity of the composition too high.
[033] Suitable flake particles for use in the present invention have an aspect ratio from 1.25 to 7, preferably from 1.5 to 5, more preferably from 1.75 to 4 and most preferably from 2 to 3.
[034] If the aspect ratio is above 7, it becomes more difficult to uniformly disperse the particles in the (co)polymer. Even though such particles may provide desired thermal conductivity, it may be difficult to achieve a uniformly dispersed mixture at the threshold volume concentration needed for bulk, thermal conductivity.
[035] "Aspect ratio", as used herein, relates to the ratio between sizes in different dimensions of a three-dimensional object, more particularly the ratio of the longest side to the shortest side, for example height to width. Ball-shaped or spherical particles therefore have an aspect ratio of about 1 , while fibres, needles or flakes have aspect ratio of more than 1 , as they have in relation to their length or length and width a comparable small diameter or thickness. The aspect ratio can be determined by scanning electron microscopy (SEM) measurements. As the software, "Analysis pro" from Olympus Soft Imaging Solutions GmbH can be used. The magnification is between x250 to x1000 and the aspect ratio is a mean value obtained by measuring the width and the length of at least 50, preferably 100 particles in the picture. In case of relatively big and flaky fillers, the SEM measurements can be obtained with a tilt angle of 45° of the sample.
[036] Suitable flake particles for use in the present invention have an average particle size (dso) from 30 to 60 μιη, preferably from 35 to 50 μιη, and more preferably from 42 to 47 μιη and most preferably from 44 to 46 μιη. The particle size can, for example, be determined by laser diffraction method according to ISO 13320:2009.
[037] Suitable spherical particles for use in the present invention have aspect ratio of 1. The aspect ratio is measured according to the test method described above.
[038] Suitable first spherical particles for use in the present invention have an average particle size (dso) from 3 to 50 μιη, preferably from 4 to 48 μιη, and more preferably from 5 to 45 μιη. The particle size can, for example, be determined by laser diffraction method according to ISO 13320:2009.
[039] Suitable second spherical particles for use in the present invention have an average particle size (dso) from 40 to 50 μιη, and preferably from 42 to 48 μιη. The particle size can, for example, be determined by laser diffraction method according to ISO 13320:2009.
[040] Suitable third spherical particles for use in the present invention have an average particle size (dso) from 2 to 10 μιη, preferably from 3 to 8 μιη, and more preferably from 4 to 6 μιη. The particle size can, for example, be determined by laser diffraction method according to ISO 13320:2009.
[041]For a given volume percentage of the filler, if the particle size is too small, the surface area of particles will increase too high, which will result in composition having too high viscosity. Whereas, too large particle size may make low pressure moulding impossible. For low pressure moulding, the nozzle orifice (opening to the mould) has a certain diameter, which will have an effect on the maximum particle size, which can be used in the composition.
[042] A thermally conductive hotmelt adhesive composition according to the present invention comprises a thermally conductive filler from 50 to 80 % by weight of the total weight of the composition, preferably from 60 to 80%. If the quantity of the thermally conductive filler is above 80%, the viscosity of the hotmelt adhesive becomes too high to mould. On the other hand, if the quantity of the thermally conductive filler is less 50%, the thermal conductivity of the adhesive composition is too low.
[043] In one preferred embodiment, the thermally conductive filler is aluminium oxide, mixture of flake aluminium oxide particles and first spherical aluminium oxide particles in a ratio of 10 : 1. In this embodiment the flake shape filler particle has an aspect ratio from 1.25 to 7 and an average particle size (dso) from 30 to 60 μιη, whereas, the spherical filler particle has an aspect ratio of 1 and an average particle size (dso) from 3 to 50 μιη.
[044] In one preferred embodiment, the thermally conductive filler is aluminium oxide, mixture of flake aluminium oxide particles and first spherical aluminium oxide particles in a ratio of 10 : 1. In this embodiment the flake shape filler particle has an aspect ratio from 1.5 to 5 and an average particle size (dso) from 30 to 60 μιη, whereas, the spherical filler particle has an aspect ratio of 1 and an average particle size (dso) from 3 to 50 μιη.
[045] In another preferred embodiment, the thermally conductive filler is aluminium oxide, mixture of flake aluminium oxide particles and first spherical aluminium oxide particles in a ratio from 4.5 : 1 to 6.5 : 1. In this embodiment the flake shape filler particle has an aspect ratio from 1.75 to 4 and an average particle size (dso) from 35 to 50 μιη, whereas, the spherical filler particle has an aspect ratio of 1 and an average particle size (dso) from 4 to 48 μιη.
[046] Yet in another preferred embodiment, the thermally conductive filler is aluminium oxide, mixture of flake aluminium oxide particles and first spherical aluminium oxide particles in a ratio from 5 : 1 to 6 : 1. In this embodiment the flake shape filler particle has an aspect ratio from 2 to 3 and an average particle size (dso) from 42 to 47 μιη, whereas, the spherical filler particle has an aspect ratio of 1 and an average particle size (dso) from 5 to 45 μιη.
[047] Yet in another preferred embodiment, the thermally conductive filler is aluminium oxide, mixture of flake aluminium oxide particles and first spherical aluminium oxide particles in a ratio from 5 : 1 to 6 : 1. In this embodiment the flake shape filler particle has an aspect ratio from 2 to 3 and an average particle size (dso) from 44 to 46 μιη μιη, whereas, the spherical filler particle has an aspect ratio of 1 and an average particle size (dso) from 5 to 45 μιη.
[048] In one preferred embodiment, the thermally conductive filler is aluminium oxide, mixture of second spherical aluminium oxide particles and third spherical aluminium oxide particles in a ratio of 10 : 1. In this embodiment the second spherical filler has an average particle size (dso) from 35 to 55 μιη, whereas, third spherical filler particle has an average particle size (dso) from 2 to 15 μιη.
[049] In another preferred embodiment, the thermally conductive filler is aluminium oxide, mixture of second spherical aluminium oxide particles and third spherical aluminium oxide particles in a ratio from 4.5 : 1 to 6.5 : 1. In this embodiment second spherical filler particle has an average particle size (dso) from 40 to 50 μιη, whereas, third spherical filler particle has an average particle size (dso) from 2 to 10 μιη.
[050] Yet in another preferred embodiment, the thermally conductive filler is aluminium oxide, mixture of second spherical aluminium oxide particles and third spherical aluminium oxide particles in a ratio from 5 : 1 to 6 : 1. In this embodiment second spherical filler particle has an average particle size (dso) from 42 to 48 μιη, whereas, third spherical filler has an average particle size (dso) from 3 to 8 μιη.
[051] Yet in another preferred embodiment, the thermally conductive filler is aluminium oxide, mixture of second spherical aluminium oxide particles and third spherical aluminium oxide particles in a ratio from 5 : 1 to 6 : 1. In this embodiment second spherical filler particle has an average particle size (dso) from 42 to 48 μιη, whereas, third spherical filler has an average particle size (dso) from 4 to 6 μιη.
[052] A thermally conductive hotmelt adhesive composition according to the present invention comprises a (co)polymer as binding agent. The term (co)polymer includes homopolymers, copolymers, block copolymers and terpolymers.
[053] In particular suitable for use in the present invention are elastomeric
(co)polymers, more preferably elastomeric thermoplastic (co)polymers. Exemplary (co)polymers that are suitable as components of the binder matrix of the compositions according to the present invention include, polyamides, preferably thermoplastic polyamides, polyolefins, preferably alpha-olefins, more preferably butyl rubber or polybutene, poly(meth)acrylates, polystyrene, polyurethanes, preferably thermoplastic polyurethane, polyesters, ethylene copolymers, ethylene vinyl copolymers, styrenic block copolymers, preferably styrene-butadiene (SB), styrene-ethylene-butadiene- styrene (SEBS), styrene-isoprene (SI), styrene-isoprene-styrene (SIS), styrene- butadiene-styrene (SBS), styrene-isoprene-butadiene (SIB), or styrene-isoprene- butadiene-styrene (SIBS), polylactic acid (PLA), copolyamides, silicones, epoxies, polyols or combinations thereof.
[054] Preferably, (co)polymers are selected from the group consisting of polyamide, thermoplastic polyamide or copolyamide, preferably polyamide or thermoplastic polyamide. These (co)polymers are preferred because they are non-toxic and safer to use compared to typical potting solutions, which contain for example amines
(amine/epoxy thermosets) or isocyanates (polyurethane thermosets).
[055] A thermally conductive hotmelt adhesive composition according to the present invention may further comprise one or more additional additives, preferably selected from the group consisting of plasticizers, dyes, waxes, antioxidants, surfactants, stabilizers, rheology modifiers, cross-linking agents, and combinations thereof.
[056] A thermally conductive hotmelt adhesive composition according to the present invention may further comprise waxes. Exemplary waxes that can be used include, without limitation, polar waxes selected from functionalized polyolefins with a molecular weight MN range as determined by GPC between about 4000 and 80000 and based on ethylene and/or propylene with acrylic acid, methacrylic acid, C1-4 alkyl esters of (meth)acrylic acid, itaconic acid, fumaric acid, vinyl acetate, carbon monoxide, and in particular maleic acid and mixtures thereof. Preferred are ethylene, propylene or ethylene-propylene (co)polymers grafted or copolymerized with polar monomers with saponification and acid values, respectively, between 2 and 50 mg KOH/g.
Saponification and acid values can be determined by titration.
[057] The rheology of the composition according to the present invention and/or the mechanical properties of the glue joint can be adjusted by the addition of so-called extender oils, i.e. aliphatic, aromatic or naphthenic oils, low molecular weight polybutenes or polyisobutylenes. Additionally poly-alpha-olefins which are liquid at 25°C can be employed which are commercially available for example under the tradename Synfluid PAO. Also conventional plasticizers, such as dialkyl or alkylaryl esters of phthalic acid or dialkyl esters of aliphatic dicarboxylic acids can be used, optionally in admixture with the afore-mentioned extender oils.
[058] A thermally conductive hotmelt adhesive composition according to the present invention may comprise a plasticizer or an extender oil from 0 to 10 % of by weight of the total weight of the composition. [059] Suitable stabilizers that can be used in the compositions according to the present invention include, without limitation, 2-(hydroxyphenyl)-benzotriazole, 2- hydroxybenzophenone, alkyl-2-cyano-3-phenylcinnamate, phenylsalicylate or 1 ,3,5- tris(2'-hydroxyphenyl)triazine. Suitable antioxidants include, without limitation, those commercially available under the trademark name Irganox® (BASF, SE). Also suitable are distearyl-pentaerythritdiphosphate compounds, octadecyl esters of 3,5-bis(1 ,1 - dimethylethyl)-4-hydroxybenzylpropanoic acid (Irganox® 1076), 2,4-bis(n-octylthio)-6- (4-hydroxy-3,5-di-tert-butylanilino)-1 ,3,5-triazine (Irganox® 565), 2-tert-butyl-6-(3-tert- butyl-2-hydroxy-5-methylbenzyl)-4-methylphenylacrylate, phosphite antioxidants, such as tris(nonylphenyl)phosphite (TNPP), tris(mono-nonylphenyl)phosphite, and tris(di- nonylphenyl)phosphite, bis(2,4-di-tert-butylphenyl)pentaerythrit diphosphate, tris(2,4-di- tert-butylphenyl)phosphite and combinations or 2 or more of the afore-mentioned compounds.
[060] A thermally conductive hotmelt adhesive composition according to the present invention may comprise a stabilizer from 0 to 5 % of by weight of the total weight of the composition.
[061] A thermally conductive hotmelt adhesive composition according to the present invention have a thermal conductivity of at least 0.500 W/(m*K), preferably at least 0.700 W/(m*K), more preferably at least 0.750 W/(m*K), most preferably at least 0.800 W/(m*K). The thermal conductivity can be determined by using Holometric's laser flash according to ASTM1461.
[062] In various embodiments, while having a high thermal conductivity, the adhesive compositions still retain a viscosity that allows simple application on to the substrate. The viscosity of the thermally conductive hotmelt adhesive according to the present invention is meant viscosity in the molten state. More particularly, in preferred embodiments, the viscosity of the adhesive composition is from 500 to 50,000 mPas, preferably from 5,000 to 25,000 mPas, more preferably from 5,000 to 15,000 mPas. The viscosity can be determined according to ASTM D 3236, except that the temperature was 210°C or 240 °C instead of 175°C.
[063] Low viscosity enables a low pressure moulding, meaning that the moulding can be done between 2 and 30 bar. This leads to the use of aluminium moulds instead of steel moulds, which decrease the price of the process. In addition, low pressure allows faster cycle times on production (10-50 seconds). Lower pressure also increase the productivity of the process, because it allows higher output compared to liquid, thermoset potting solutions (reduced number of process steps). Lower pressure also causes less damage to the electronic components.
[064] A thermally conductive hotmelt adhesive composition according to the present invention can be produced by conventional means. Preferred methods include the manufacture by mixers, for example planetary mixer, planetary dissolver, kneader, internal mixer and extruder.
[065] Generally, a thermally conductive hotmelt adhesive composition according to the present invention can be produced by melting first the (co)polymer and optionally additive(s) and then mixing until a homogenous mixture is obtain. Subsequently, the filler particles are added into the mixture in any order. The final composition is then thoroughly mixed and allowed to cool to a room temperature.
[066] The thermally conductive hotmelt adhesive composition according to the present invention is intended to encapsulate heat generating devices, such as printed circuit boards to provide better heat dissipation. The encapsulates can be prepared via low pressure moulding.
[067] Accordingly, the invention is directed to a method of encapsulating a heat generating device comprising steps of: a) applying by using injection moulding the thermally conductive hotmelt adhesive composition according to the present invention to the surface of said heat generating device by low pressure moulding;
b) cooling; and
c) removing from the mould.
[068] Preferably, the liquefied thermally conductive hotmelt adhesive composition is injected at temperature of 210°C and under low pressure.
[069] The thermally conductive hotmelt adhesive composition according to the present invention can be applied using low pressure injection moulding instead of the typical potting process. Low pressure can be used, between 2 and 30 bar. The hotmelt adhesive according to the present invention also enables fast curing cycle times from 10 to 50 seconds instead of prolonged curing cycles. In addition the hotmelt adhesive according to the present invention provides clean and simple process, having no need to mix two components or perform the process under vacuum. Finally, the process according to the present invention requires less energy, because the heat curing step has been eliminated.
[070] The thermally conductive hotmelt adhesive composition according to the present invention can also be used in the gluing of components of the electronic devices together e.g. circuit boards, electronic components, sensors and control systems.
[071] The present invention also covers method for bonding two substrates and for producing an article of manufacture by bonding two substrates. In these methods, the thermally conductive hotmelt adhesive composition according to the present invention is applied in molten state onto the substrate surface, for example by a roll coating or by bead application. The substrate surface with the adhesive is then pressed onto the other substrate to be bonded. The substrate may include metal plates. [072] A thermally conductive hotmelt adhesive composition according to the present invention may therefore be used to bond metal plating to a plastic or metal substrate. In these applications the thermal conductivity of the adhesive is of particular importance.
[073] Accordingly, the invention is directed to a method of manufacturing an article comprising at least two bonded substrates, comprising steps of:
a) applying the thermally conductive hotmelt adhesive composition according to the present invention to the surface of a first substrate to be bonded; and
b) bringing the surface of the first substrate to be bonded comprising the thermally conductive hotmelt adhesive composition into contact with a second substrate to be bonded.
[074] Depending on the number of substrates to be bonded, steps (a) and (b) may be repeated to bond a third or further substrate to the already bonded substrates.
Therefore, the method would comprise further step (c) optionally repeating steps (a) and (b) with a third or further substrate to be bonded.
[075] Also encompassed by the present invention are the articles of manufacture that are obtainable according to the methods described herein and that include the adhesives described herein.
[076] The adhesive compositions described herein can be used in various fields, the manufacture of electronic devices. More specifically, they can be used in the
manufacturing and bonding of pipes, preferably cooling coils; electronic components, preferably in light emitting devices, computer devices, mobile phones, tablets, touch screens, and audio systems; automotive technology; in joints between heat pipes and water tanks in solar heated heating; in fuel cells and wind turbines; in the manufacture of computer chips; in light devices; batteries; in housings; coolers; heat exchanging devices; wires, such as heating wires; cables; refrigerators; dishwashers; air
conditionings; accumulators; transformers; lasers; functional clothing; car seats; medical devices; fire protection; electric motors; planes; and trains; and as a filament in 3D printing material.
[077] In highly preferred embodiment, the thermally conductive hotmelt adhesive composition according to the present invention can be used as a potting or moulded encapsulant to encapsulate heat generating devices such as printed circuit boards to provide improved heat dissipation.
[078] The invention is further illustrated by the following examples. It is however understood that these examples are for purpose of illustration only and not to be construed as limiting the invention.
Examples
[079] Examples E1 to E3 and Comparative Examples V1 to V4.
Different adhesive compositions were prepared with their compositions shown in Table
1.
To obtain the compositions, first the (co)polymer and optionally additive(s) were heated until the (co)polymer is molten and then mixed until a homogenous phase is obtain. To this phase, the fillers are subsequently given in any order. The final composition is then thoroughly mixed and allowed to cool to room temperature.
Table 1: Adhesive compositions
Figure imgf000020_0001
Polyamide 1 is Technomelt OM673 from Henkel; Spherical alumina 1 is DAW/DAM-12 from Denka; Spherical alumina 2 is DAW/DAM-05 from Denka; Spherical alumina 3 is DAW/DAM-50 from Denka; Spherical alumina 4 is DAW/DAM-45 from Denka; Tabular alumina is Tabular alumina T60/T64 from Almatis.
The adhesive formulations were then tested with respect to their thermal conductivity and viscosity. The measurements have been made according to the test methods described above. The viscosity has been measured at 210 °C. The results are shown in Table 2. Table 2: Thermal conductivity and viscosity measurements
Figure imgf000021_0001
[080] It can be seen from the examples and comparative examples that a significantly improved thermal conductivity can be obtained by compositions according to the present invention.

Claims

What is Claimed is:
1. A thermally conductive hotmelt adhesive composition comprising:
a) at least one thermally conductive filler, wherein
said at least one thermally conductive filler contains a mixture of flake particles and first spherical particles in a ratio of 10 : 1 , and wherein said flake particles have an aspect ratio of 1.25 to 7,
or
said at least one thermally conductive filler contains a mixture of second spherical particles having an average particle size from 35 - 55 μιη and third spherical particles having an average particle size from 2 - 15 μιη in a ratio of 10 : 1 , and wherein
said at least one thermally conductive filler is selected from the group consisting of tin oxide, indium oxide, antimony oxide, aluminum oxide, titanium oxide, iron oxide, magnesium oxide, zinc oxide, oxides of rare earth metals; alkaline and alkaline earth metal sulphates; chalk; boron nitride; alkaline silicate, silica, iron, copper, aluminum, zinc, gold, silver and tin, alkaline and alkaline earth metal halides; alkaline and alkaline earth metal phosphates; and mixtures thereof; and
b) at least one (co)polymer selected from the group consisting of polyamides, thermoplastic polyamides, copolyamides, butyl rubber, polybutene, poly(meth)acrylates, polystyrene, polyurethanes, thermoplastic polyurethane, polyesters, ethylene
copolymers, ethylene vinyl copolymers, styrene-butadiene (SB), styrene-ethylene- butadiene-styrene (SEBS), styrene-isoprene (SI), styrene-isoprene-styrene (SIS), styrene-butadiene-styrene (SBS), styrene-isoprene-butadiene (SIB), styrene-isoprene- butadiene-styrene (SIBS), polylactic acid (PLA), silicones, epoxies, polyols and mixtures thereof.
2. A thermally conductive hotmelt adhesive composition according to claim 1 , wherein sad flake particles have an aspect ratio from 1.5 to 5, preferably from 1.75 to 4 and most preferably from 2 to 3.
3. A thermally conductive hotmelt adhesive composition according to claim 1 or 2, wherein said flake particles have an average particle size (dso) from 30 to 60 μιη, preferably from 35 to 50 μιη, and more preferably from 42 to 47 μιη and most preferably from 44 to 46 μιη.
4. A thermally conductive hotmelt adhesive composition according to any of claims 1 to 3, wherein said first spherical particles have an average particle size (dso) from 3 to 50 μιη, preferably from 4 to 48 μιη, and more preferably from 5 to 45 μιη.
5. A thermally conductive hotmelt adhesive composition according to any of claims 1 to 4, wherein ratio of flake particles to first spherical particles or ratio of second spherical particles to third spherical particles is from 4.5 : 1 to 6.5 : 1 , preferably from 5 : 1 to 6 : 1.
6. A thermally conductive hotmelt adhesive composition according to any of claims 1 to 5, wherein said second spherical particles have an average particle size (dso) from 40 to 50 μιη, and preferably from 42 to 48 μιη.
7. A thermally conductive hotmelt adhesive composition according to any of claims 1 to 6, wherein said third spherical particles have an average particle size (dso) from 2 to 10 μιη, preferably from 3 to 8 μιη, and more preferably from 4 to 6 μιη.
8. A thermally conductive hotmelt adhesive composition according to any of claims 1 to 7, wherein said at least one thermally conductive filler is boron nitride or aluminum oxide, preferably said at least one thermally conductive filler is aluminum oxide.
9. A thermally conductive hotmelt adhesive composition according to any of claims 1 to 8, wherein said at least one at least one (co)polymer is polyamide, thermoplastic polyamide or copolyamide, preferably polyamide or thermoplastic polyamide.
10. A thermally conductive hotmelt adhesive composition according to any of claims 1 to 8, wherein said composition comprises a thermally conductive filler from 50 to 80% by weight of the total weight of the composition, preferably from 60 to 80%.
11. A thermally conductive hotmelt adhesive composition according to any of claims
1 to 10, wherein said composition comprises a ( copolymer from 20 to 50% by weight of the total weight of the composition, preferably from 20 to 40%.
12. A thermally conductive hotmelt adhesive composition according to any one of claims 1 to 11 , wherein the viscosity of the adhesive composition is from 500 to 50,000 mPas, preferably from 5,000 to 25,000 mPas, more preferably from 5,000 to 15,000 mPas.
13. A thermally conductive hotmelt adhesive composition according to any one of claims 1 to 12, wherein the thermal conductivity of the adhesive composition is at least 0.500 W/(m*K), preferably at least 0.700 W/(m*K), more preferably at least 0.750 W/(m*K), most preferably at least 0.800 W/(m*K).
14. A method of encapsulating a heat generating device comprising steps of:
a) applying the thermally conductive hotmelt adhesive composition according to any of claims 1 - 13 to the surface of said heat generating device by low pressure moulding;
b) cooling; and
c) removing from the mould.
15. Use of the thermally conductive hotmelt adhesive composition according to any one of claims 1 to 13 in pipes, preferably cooling coils; in electronic components, preferably in light emitting devices, computer devices, mobile phones, tablets, touch screens, automotive technology hifi systems, and audio systems; in joints between heat pipes and water tanks in solar heated heating; in fuel cells and wind turbines; in the manufacture of computer chips; in light devices; batteries; in housings; coolers; heat exchanging devices; wires; cables; heating wires; refrigerators; dishwashers; air conditionings; accumulators; transformers; lasers; functional clothing; car seats; medical devices; fire protection; electric motors; planes; and trains; as a filament for 3D printing material.
16. Use of the thermally conductive hotmelt adhesive composition according to any one of claims 1 to 13 as a potting or moulded encapsulant for encapsulating heat generating devices.
PCT/EP2016/062972 2015-06-08 2016-06-08 High thermally conductive low pressure mouldable hotmelt WO2016198425A1 (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
KR1020177035072A KR20180016381A (en) 2015-06-08 2016-06-08 High thermally conductive low pressure mouldable hotmelt
EP16728671.5A EP3303494A1 (en) 2015-06-08 2016-06-08 High thermally conductive low pressure mouldable hotmelt
JP2017563583A JP2018522968A (en) 2015-06-08 2016-06-08 High thermal conductivity low pressure formable hot melt
CN201680032339.7A CN107667156A (en) 2015-06-08 2016-06-08 High thermal conductivity can low pressure molding hotmelt
US15/830,152 US20180094171A1 (en) 2015-06-08 2017-12-04 High thermally conductive low pressure mouldable hotmelt

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US201562172515P 2015-06-08 2015-06-08
US62/172,515 2015-06-08

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US15/830,152 Continuation US20180094171A1 (en) 2015-06-08 2017-12-04 High thermally conductive low pressure mouldable hotmelt

Publications (1)

Publication Number Publication Date
WO2016198425A1 true WO2016198425A1 (en) 2016-12-15

Family

ID=56119486

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2016/062972 WO2016198425A1 (en) 2015-06-08 2016-06-08 High thermally conductive low pressure mouldable hotmelt

Country Status (7)

Country Link
US (1) US20180094171A1 (en)
EP (1) EP3303494A1 (en)
JP (1) JP2018522968A (en)
KR (1) KR20180016381A (en)
CN (1) CN107667156A (en)
TW (1) TW201704413A (en)
WO (1) WO2016198425A1 (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2019158599A1 (en) 2018-02-16 2019-08-22 Covestro Deutschland Ag Method for applying a material containing a meltable polymer, more particularly a hot-melt adhesive, above the decomposition temperature thereof
WO2020016115A1 (en) 2018-07-16 2020-01-23 Covestro Deutschland Ag Method for applying a material containing a meltable polymer with blocked nco groups
WO2020016114A1 (en) 2018-07-16 2020-01-23 Covestro Deutschland Ag Method for applying a material containing a meltable polymer with free nco groups
EP3616915A1 (en) 2018-08-29 2020-03-04 3M Innovative Properties Company 3d printed component part comprising a composite material of a thermoplastically workable material and boron nitride, method for making a 3d printed component part and use of a 3d printed component part
US11332628B2 (en) 2018-08-29 2022-05-17 3M Innovative Properties Company 3D printed component part comprising a matrix material-boron nitride composite, method for making a 3D printed component part and use of a 3D printed component part
US11486545B2 (en) 2020-07-31 2022-11-01 Toyota Jidosha Kabushiki Kaisha Tank and manufacturing method for tank

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR3084202B1 (en) * 2018-07-20 2020-10-23 Inst Supergrid ELECTRICAL INSULATION MATERIAL INCLUDING A MIXTURE OF INORGANIC MICROMETRIC CHARGES AND METHOD OF MANUFACTURING
IT201800021346A1 (en) * 2018-12-28 2020-06-28 Enrico Luigi Seveso Hot-melt resin to dissipate heat, electrically non-conductive and / or electrically insulating.
CN112521758A (en) * 2019-09-19 2021-03-19 台橡股份有限公司 3D printed polymer composition, material and method thereof and molded product

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040118579A1 (en) * 2002-12-19 2004-06-24 3M Innovative Properties Company Flexible heat sink
US20130065987A1 (en) * 2011-09-13 2013-03-14 Nitto Denko Corporation Thermal conductive sheet and producing method thereof
CN104017529A (en) * 2014-04-14 2014-09-03 江苏嘉娜泰有机硅有限公司 Single-component epoxy resin conductive silver adhesive composition and preparation method thereof

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3474839B2 (en) * 1999-09-01 2003-12-08 北川工業株式会社 Thermal conductive sheet and manufacturing method thereof
JP4890063B2 (en) * 2006-03-20 2012-03-07 新日鐵化学株式会社 Resin composition, varnish obtained using this resin composition, film adhesive and copper foil with film adhesive
JP5089908B2 (en) * 2006-04-06 2012-12-05 株式会社マイクロン High thermal conductive resin compound / high thermal conductive resin molding / mixing particles for heat radiating sheet, high thermal conductive resin compound / high thermal conductive resin molding / heat radiating sheet, and manufacturing method thereof
EP2623562B1 (en) * 2010-09-30 2018-01-31 Ube Industries, Ltd. Polyamide resin composition and molded article comprising same
CN102690495B (en) * 2012-05-30 2014-10-22 日邦树脂(无锡)有限公司 Hot-melting type halogen-free fire-retardant heat conducting and dielectric insulating layer resin and application thereof
CN103045158B (en) * 2013-01-23 2014-12-24 北京海斯迪克新材料有限公司 Halogen-free high-flame retardance addition type heat conduction silicon rubber adhesive
JP6361352B2 (en) * 2013-08-12 2018-07-25 宇部興産株式会社 Polyamide elastomer composition and molded body using the same
CN103834352B (en) * 2014-02-26 2016-03-09 北京天山新材料技术有限公司 Two component height heat conduction joint sealants of excellent in mechanical performance and preparation method thereof

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040118579A1 (en) * 2002-12-19 2004-06-24 3M Innovative Properties Company Flexible heat sink
US20130065987A1 (en) * 2011-09-13 2013-03-14 Nitto Denko Corporation Thermal conductive sheet and producing method thereof
CN104017529A (en) * 2014-04-14 2014-09-03 江苏嘉娜泰有机硅有限公司 Single-component epoxy resin conductive silver adhesive composition and preparation method thereof

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
BOWEN P: "Particle Size Distribution Measurement from Millimeters to Nanometers and from Rods to Platelets", JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY, TAYLOR AND FRANCIS GROUP, NEW YORK, NY, US, vol. 23, no. 5, 1 January 2002 (2002-01-01), pages 631 - 662, XP009102859, ISSN: 0193-2691, DOI: 10.1081/DIS-120015368 *
DATABASE WPI Week 201479, Derwent World Patents Index; AN 2014-V38903, XP002760497 *

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2019158599A1 (en) 2018-02-16 2019-08-22 Covestro Deutschland Ag Method for applying a material containing a meltable polymer, more particularly a hot-melt adhesive, above the decomposition temperature thereof
WO2020016115A1 (en) 2018-07-16 2020-01-23 Covestro Deutschland Ag Method for applying a material containing a meltable polymer with blocked nco groups
WO2020016114A1 (en) 2018-07-16 2020-01-23 Covestro Deutschland Ag Method for applying a material containing a meltable polymer with free nco groups
EP3616915A1 (en) 2018-08-29 2020-03-04 3M Innovative Properties Company 3d printed component part comprising a composite material of a thermoplastically workable material and boron nitride, method for making a 3d printed component part and use of a 3d printed component part
WO2020044236A1 (en) 2018-08-29 2020-03-05 3M Innovative Properties Company 3d printed component comprising a composite material of a thermoplastic material and boron nitride, method for making a 3d printed component and use of 3d printed component
US11332628B2 (en) 2018-08-29 2022-05-17 3M Innovative Properties Company 3D printed component part comprising a matrix material-boron nitride composite, method for making a 3D printed component part and use of a 3D printed component part
US11486545B2 (en) 2020-07-31 2022-11-01 Toyota Jidosha Kabushiki Kaisha Tank and manufacturing method for tank

Also Published As

Publication number Publication date
KR20180016381A (en) 2018-02-14
CN107667156A (en) 2018-02-06
US20180094171A1 (en) 2018-04-05
TW201704413A (en) 2017-02-01
EP3303494A1 (en) 2018-04-11
JP2018522968A (en) 2018-08-16

Similar Documents

Publication Publication Date Title
EP3303494A1 (en) High thermally conductive low pressure mouldable hotmelt
US10689551B2 (en) Thermally conductive adhesive
JP5882581B2 (en) Thermally conductive sheet, method for producing the same, and heat dissipation device
TWI308171B (en) Thermal interface materials
JP7196200B2 (en) Conductive adhesive, raw material composition, electronic component, manufacturing method and use
KR102064318B1 (en) Electrically conductive adhesive compound and adhesive tape
JP5560630B2 (en) HEAT CONDUCTIVE SHEET, METHOD FOR PRODUCING THE HEAT CONDUCTIVE SHEET, AND HEAT DISCHARGE DEVICE USING HEAT CONDUCTIVE SHEET
KR101927474B1 (en) Electrically conductive heat-activated adhesive compound
CN105647405A (en) Conductive film-like adhesive, film-like adhesive attached dicing tape and manufacturing method of semiconductor device
CN106661390A (en) Maleimide film
WO2014103814A1 (en) Resin composition and tabular insert-molded body
TW201229185A (en) Anisotropic conductive film
TW201605944A (en) Composite magnetic material
JP5454300B2 (en) HEAT CONDUCTIVE SHEET, ITS MANUFACTURING METHOD, AND HEAT DISCHARGE DEVICE USING SAME
JP2017045934A (en) Adhesive film
JP2011184663A (en) Heat conductive sheet, method for producing the same, and heat radiation device using the same
CN114672262B (en) Heat-resistant self-adhesive protective film and preparation method thereof
JP5917968B2 (en) POLYMER TYPE ANTISTATIC AGENT, POLYMER COMPOSITION, AND MOLDED ARTICLE
JP2020196885A (en) Resin composition for electric/electronic component sealing
JP2009120825A (en) Stabilized resin cross-linking agent

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 16728671

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 20177035072

Country of ref document: KR

Kind code of ref document: A

ENP Entry into the national phase

Ref document number: 2017563583

Country of ref document: JP

Kind code of ref document: A

NENP Non-entry into the national phase

Ref country code: DE

WWE Wipo information: entry into national phase

Ref document number: 2016728671

Country of ref document: EP