Highly thermally-conductive moldable thermoplastic composites and compositions

• US 8,299,159 B2
• Filed: 05/04/2010
• Issued: 10/30/2012
• Est. Priority Date: 08/17/2009
• Status: Active Grant

• Current Assignee: Laird Technologies Incorporated (DuPont de Nemours, Inc.)
• Original Assignee: Laird Technologies Incorporated (DuPont de Nemours, Inc.)
• Inventors: Chandrasekhar, Bukkinakere Kapanipathaiya, Ramachandraiah, Manjunatha Hosahalli, Kumar, Bambore Lokeshwarappa Santhosh, Duraiswamy, Srinivasan
• Primary Examiner(s): Harlan, Robert D.
• Application Number:
  US12/773,422
• Publication Number:
  US 20110040007A1
• Time in Patent Office: 910 Days
• Field of Search: 524/404, 524/440, 524/428, 524/433, 977/742
• US Class Current: 524/404
• CPC Class Codes: B29C 45/0001 characterised by the choice of material
• CPC Class Codes: B29K 2995/0013 Conductive
• CPC Class Codes: H01B 1/22 the conductive material comprising metals or alloys
• CPC Class Codes: H01B 1/24 the conductive material comprising carbon-silicon compounds, carbon or silicon

Abstract

Thermally-conductive moldable thermoplastic compositions or composites may generally include a plurality of metal-coated filler particles; a plurality of secondary filler particles; and a polymer matrix in admixture with the metal-coated filler particles and the secondary filler particles. The composition or composite may have a thermal conductivity ranging from about 20 Watts per meter-Kelvin to about 35 Watts per meter-Kelvin. Injection molded articles having a moldable thermally-conductive thermoplastic composition or composite can be formed for microelectronics, automotive, avionic, and other heat dissipation applications.

Claims

1. A moldable thermally-conductive thermoplastic composition comprising:

a plurality of metal-coated filler particles; and

a polymer matrix in admixture with the metal-coated filler particles,

wherein the amount of metal-coated filler particles is at least about 50% volume of the total composition.

2. The moldable thermally-conductive thermoplastic composition of claim 1, wherein the plurality of metal-coated filler particles comprise one or more of:

metal-coated graphite particles; and

/or

metal-coated perlite particles having one or more metal coatings; and

/or combinations thereof.

3. The moldable thermally-conductive thermoplastic composition of claim 1, wherein the plurality of metal-coated filler particles comprise perlite particles having a first metal coating and a second metal coating that is the same metal or a different metal than the first metal coating.

4. The moldable thermally-conductive thermoplastic composition of claim 1, wherein the plurality of metal-coated filler particles comprise one or more of silver-coated graphite particles, silver-coated copper-coated perlite particles, nickel-coated copper-coated perlite particles, cobalt-coated copper-coated perlite particles, aluminum-coated copper-coated perlite particles, iron-coated copper-coated perlite particles, gold-coated copper-coated perlite particles, platinum-coated copper-coated perlite particles, palladium-coated copper-coated perlite particles, zinc-coated copper-coated perlite particles, or combinations thereof.

5. The moldable thermally-conductive thermoplastic composition of claim 1, wherein:

the plurality of metal-coated filler particles comprise one or more metal coatings of one or more of gold, silver, nickel, zinc, palladium, platinum, copper, iron, cobalt, aluminum, or combinations thereof; and

/or

the plurality of metal-coated filler particles comprise metal-coated perlite particles having a porosity ranging from 40% to about 99% or from about 80% to about 90%.

6. The moldable thermally-conductive thermoplastic composition of claim 1, wherein the moldable thermally-conductive thermoplastic composition further includes secondary filler particles, such that the amount of the metal-coated filler particles and the secondary filler particles combined range from about 40% to about 80% or from about 50% to about 70% of the total thermoplastic composition by volume.

7. The moldable thermally-conductive thermoplastic composition of claim 1, further including a plurality of secondary filler particles, wherein the plurality of secondary filler particles comprises one or more of carbon fiber, boron nitride, graphite, nano graphite platelets, carbon nanotubes, carbon black, aluminum nitride, silicon nitride, aluminum oxide, magnesium oxide, or combinations thereof.

8. The moldable thermally-conductive thermoplastic composition of claim 1, wherein the composition has a thermal conductivity ranging from about 10 Watts per meter-Kelvin to about 35 Watts per meter-Kelvin or from about 20 Watts per meter-Kelvin to about 35 Watts per meter-Kelvin, and the composition is formulated for injection molding applications.

9. The moldable thermally-conductive thermoplastic composition of claim 1, wherein the polymer matrix comprises one or more of acrylonitrile butadiene styrene (ABS) (chemical formula (C₈H₈.C₄H₆.C₃H₃N)_n);

polycarbonate/acrylonitrile butadiene styrene alloys (PC-ABS);

polybutylene terephthalate;

polyphenylene oxide;

polyphenylene sulfide (PPS);

polyphenylene ether;

modified polyphenylene ether containing polystyrene;

liquid crystal polymers;

polystyrene;

styrene-acrylonitrile copolymer;

rubber-reinforced polystyrene;

poly ether ether ketone (PEEK);

acrylic resins such as polymers and copolymers of alkyl esters of acrylic and methacrylic acid;

styrene-methyl methacrylate copolymer;

styrene-methyl methacrylate-butadiene copolymer;

polymethyl methacrylate;

methyl methacrylate-styrene copolymer;

polyvinyl acetate;

polysulfone;

polyether sulfone;

polyether imide;

polyarylate;

polyamideimide;

polyvinyl chloride;

vinyl chloride-ethylene copolymer;

vinyl chloride-vinyl acetate copolymer;

polyimides, polyamides;

polyolefins such as polyethylene;

ultra high molecular weight polyethylene;

high density polyethylene;

linear low density polyethylene;

polyethylene napthalate;

polyethylene terephthalate;

polypropylene;

chlorinated polyethylene;

ethylene acrylic acid copolymers;

polyamides, nylon, nylon 6, nylon 6,6,;

phenylene oxide resins;

phenylene sulfide resins;

polyoxymethylenes;

polyesters;

polyvinyl chloride;

vinylidene chloride/vinyl chloride resins; and

vinyl aromatic resins such as polystyrene, poly(vinylnaphthalene), and poly(vinyltoluene);

polyimides;

polyaryletheretherketone;

polyphthalamide;

polyetheretherketones;

polyaryletherketone;

polycarbonate;

polyphenylene;

or combinations thereof.

10. A moldable thermally-conductive thermoplastic composition of claim 1, wherein:

the plurality of metal-coated filler particles are silver-coated graphite, the moldable thermally-conductive thermoplastic composition further includes a plurality of secondary filler particles that are carbon fiber, and the polymer matrix is liquid crystal polymer;

or

the plurality of metal-coated filler particles are silver-coated copper-coated perlite, the moldable thermally-conductive thermoplastic composition further includes a plurality of secondary filler particles that are boron nitride and carbon fiber, and the polymer matrix is liquid crystal polymer;

or

the plurality of metal-coated filler particles are silver-coated graphite and silver-coated perlite and the polymer matrix is liquid crystal polymer;

or

the plurality of metal-coated filler particles are silver-coated copper-coated perlite, the moldable thermally-conductive thermoplastic composition further includes a plurality of secondary filler particles that are boron nitride and carbon fiber, and the polymer matrix is liquid crystal polymer;

or

the plurality of metal-coated filler particles are silver-coated copper-coated perlite, the moldable thermally-conductive thermoplastic composition further includes a plurality of secondary filler particles that are carbon fiber, and the polymer matrix is polyphenylene sulfide;

or

the plurality of metal-coated filler particles are silver-coated graphite and silver-coated copper-coated perlite, and the polymer matrix is liquid crystal polymer;

or

the plurality of metal-coated filler particles are silver-coated graphite and the polymer matrix is liquid crystal polymer.

11. An article comprising the moldable thermally-conductive thermoplastic composition of claim 1.

20. The moldable thermally-conductive thermoplastic composition of claim 1, wherein the plurality of metal-coated filler particles comprise graphite particles and perlite particles at least partially coated with metal.

21. The moldable thermally-conductive thermoplastic composition of claim 1, wherein the plurality of metal-coated filler particles comprise silver-coated copper-coated perlite particles.

22. The moldable thermally-conductive thermoplastic composition of claim 1, wherein the total amount of metal-coated filler particles is between 50% and 80% by volume of the total composition.

23. The moldable thermally-conductive thermoplastic composition of claim 1, wherein the plurality of metal-coated filler particles comprise graphite particles at least partially coated with metal in an amount ranging from about 5% to about 80% by volume, and an amount of perlite particles at least partially coated with metal such that the total amount of metal-coated filler particles is between about 50% and about 80% by volume of the total composition.

24. The moldable thermally-conductive thermoplastic composition of claim 1, wherein the plurality of metal-coated filler particles comprise perlite particles and silver dispersed over the perlite particles with approximately 67 percent or less surface coverage of the perlite particles by the silver.

12. A moldable thermally-conductive thermoplastic composition comprising a polymer matrix admixed with metal containing filler particles including one or more of graphite, perlite, and combinations thereof at least partially coated with metal, the moldable thermally-conductive thermoplastic composition having a thermal conductivity greater than 10 Watts per meter-Kelvin Kelvin and formulated for injection molding applications.

13. The moldable thermally-conductive thermoplastic composition of claim 12, wherein:

the metal containing filler particles comprise perlite particles having a first metal coating and a second metal coating that is the same metal or a different metal than the first metal coating; and

/or

the metal containing filler particles comprise perlite particles at least partially coated with one or more of gold, silver, nickel, zinc, palladium, platinum, copper, iron, cobalt, and aluminum; and

/or

the metal containing filler particles comprise metal-coated perlite particles having a porosity ranging from 40% to about 99% or from 80% to about 99%; and

/or

the metal containing filler particles comprise perlite particles having first and second metal coatings, and wherein the weight of the metal particles of the first and second metal coatings ranges from about 100% to about 400% of the weight of the perlite particles; and

/or

the metal containing filler particles comprise perlite particles having a first copper coating and a second silver coating.

14. The moldable thermally-conductive thermoplastic composition of claim 12, wherein the polymer matrix comprises one or more of acrylonitrile butadiene styrene (ABS) (chemical formula (C₈H₈.C₄H₆.C₃H₃N)_n);

polycarbonate/ acrylonitrile butadiene styrene alloys (PC-ABS);

polybutylene terephthalate;

polyphenylene oxide;

polyphenylene sulfide (PPS);

polyphenylene ether;

modified polyphenylene ether containing polystyrene;

liquid crystal polymers;

polystyrene;

styrene-acrylonitrile copolymer;

rubber-reinforced polystyrene;

poly ether ether ketone (PEEK);

acrylic resins such as polymers and copolymers of alkyl esters of acrylic and methacrylic acid;

styrene-methyl methacrylate copolymer;

styrene-methyl methacrylate-butadiene copolymer;

polymethyl methacrylate;

methyl methacrylate-styrene copolymer;

polyvinyl acetate;

polysulfone;

polyether sulfone;

polyether imide;

polyarylate;

polyamideimide;

polyvinyl chloride;

vinyl chloride-ethylene copolymer;

vinyl chloride-vinyl acetate copolymer;

polyimides, polyamides;

polyolefins such as polyethylene;

ultra high molecular weight polyethylene;

high density polyethylene;

linear low density polyethylene;

polyethylene napthalate;

polyethylene terephthalate;

polypropylene;

chlorinated polyethylene;

ethylene acrylic acid copolymers;

polyamides, nylon, nylon 6, nylon 6,6,;

phenylene oxide resins;

phenylene sulfide resins;

polyoxymethylenes;

polyesters;

polyvinyl chloride;

vinylidene chloride/vinyl chloride resins; and

vinyl aromatic resins such as polystyrene, poly(vinylnaphthalene), and poly(vinyltoluene);

polyimides;

polyaryletheretherketone;

polyphthalamide;

polyetheretherketones;

polyaryletherketone;

polycarbonate;

polyphenylene;

or combinations thereof.

15. The moldable thermally-conductive thermoplastic composition of claim 12, wherein:

the moldable thermally-conductive thermoplastic composition has a polymer matrix volume less than 40% by volume; and

/or

the moldable thermally-conductive thermoplastic composition has a polymer matrix volume varying from about 20% to about 40% by volume and an amount of metal containing filler particles ranging from about 40% to about 70%, the composition balanced to 100% volume with secondary filler particles, said composition having a thermal conductivity ranging from about 20 Watts per meter-Kelvin to about 35 Watts per meter-Kelvin; and

/or

the moldable thermally-conductive thermoplastic composition further comprises secondary filler particles including one or more of carbon fiber, boron nitride, graphite, nano graphite pellets, carbon nanotubes, carbon black, aluminum nitride, and combinations thereof.

16. An article comprising the moldable thermally-conductive thermoplastic composition of claim 12.

25. The moldable thermally-conductive thermoplastic composition of claim 12, wherein the metal containing filler particles comprise graphite particles and perlite particles at least partially coated with metal.

26. The moldable thermally-conductive thermoplastic composition of claim 12, wherein the metal containing filler particles comprise silver-coated copper-coated perlite particles.

27. The moldable thermally-conductive thermoplastic composition of claim 12, wherein the total amount of metal containing filler particles is at least about 50% by volume of the total composition.

17. A method of producing a moldable thermally-conductive thermoplastic composition comprising a plurality of metal-coated filler particles and a polymer matrix in admixture with the metal-coated filler particles and having a thermal conductivity of at least 10 Watts per meter Kelvin, the method comprising mixing the metal-coated filler particles in the polymer matrix such that the amount of metal-coated filler particles is at least about 50% volume of the total composition.

18. The method of claim 17, wherein mixing comprises melt blending and/or solution blending.

19. The method of claim 17, wherein:

the metal-coated filler particles comprise one or more of metal-coated graphite particles, metal-coated perlite particles having one or more metal coatings, silver-coated copper-coated perlite particles, silver-coated graphite particles, or combinations thereof; and

/or

the method includes mixing secondary filler particles in the polymer matrix, wherein the secondary filler particles comprise one or more of carbon fiber, boron nitride, and/or combinations thereof.