COMPOSITION COMPRISING CARBON BLACK AND EXPANDED GRAPHITE AND SHAPED ARTICLES AND SUBSTRATE COATINGS COMPRISING SAME, USES THEREOF AND METHODS FOR REDUCING VOLUME RESISTIVITY AND FOR PROVIDING ELECTROMAGNETIC INTERFERENCE SHIELDING AS WELL AS THERMAL CONDUCTIVITY
20240409747 ยท 2024-12-12
Inventors
Cpc classification
C08L77/02
CHEMISTRY; METALLURGY
C08K2201/003
CHEMISTRY; METALLURGY
C01P2004/61
CHEMISTRY; METALLURGY
C08K2201/006
CHEMISTRY; METALLURGY
C08L77/02
CHEMISTRY; METALLURGY
H05K9/0081
ELECTRICITY
C08K2201/014
CHEMISTRY; METALLURGY
C08K2201/005
CHEMISTRY; METALLURGY
C09C1/0081
CHEMISTRY; METALLURGY
C01P2004/64
CHEMISTRY; METALLURGY
International classification
C09C1/00
CHEMISTRY; METALLURGY
Abstract
The present invention is directed to compositions comprising carbon black and expanded graphite as well as shaped articles and coatings for substrates comprising the compositions. The present invention also relates to the use thereof and methods for reducing electrical resistivity and providing electromagnetic interference shielding as well as thermal conductivity. The compositions of the invention allow for high electrical conductivity, EMI shielding performance as well as thermal conductivity without compromising rheological properties like fluidity or viscosity, for example measured as the melt flow rate, or mechanical properties such as, impact resistance, tensile strength or elongation at break.
Claims
1-5. (canceled)
6. Composition comprising (a) carbon black; and (b) expanded graphite; wherein the carbon black is characterized by a BET specific surface area measured according to ASTM D-3037 under nitrogen of less than 950 m.sup.2.Math.g.sup.1; wherein the expanded graphite is characterized by one or more of the following: a particle size distribution D.sub.90 when measured according to ISO 13220 of 5 to 1000 m; and/or a bulk density when measured according to ASTM D-7481 standard of 0.01 to 1.00 g.Math.cm.sup.3.
7. The composition of claim 6, wherein the composition comprises the carbon black in an amount of 3 to 40 wt.-% based on the total weight of the composition; and wherein the composition comprises expanded graphite in an amount of 3 to 50 wt. %.
8. (canceled)
9. The composition according to claim 7, wherein the composition comprises carbon black and expanded graphite in a combined amount of 10 to 50 wt.-% based on the total weight of the composition.
10. The composition according to claim 9, wherein the ratio of wt.-% based on the total weight of the composition of carbon black to graphite is in the range of 0.1 to 9.
11. Composition comprising carbon black and expanded graphite, wherein the ratio of wt.-% based on the total weight of the composition of carbon black to graphite is in the range of 0.1 to 9 and wherein the carbon black is characterized by a BET specific surface area measured according to ASTM D-3037 under nitrogen of less than 950 m.sup.2.Math.g.sup.1; and/or wherein the expanded graphite is characterized by one or more of the following: a particle size distribution Do when measured according to ISO 13220 of 5 to 1000 m; and/or a bulk density when measured according to ASTM D-3037 of 0.01 to 1.00 g.Math.cm.sup.3.
12. The composition of claim 11, wherein the composition comprises the carbon black in an amount of 3 to 40 wt.-% based on the total weight of the composition; and wherein the composition comprises the expanded graphite in an amount of 3 to 50 wt.-% based on the total weight of the composition.
13. The composition according to claim 11, wherein the carbon black s characterized by one or more of the following: a primary article size measured according to ASTM D-3849-14a of 10 to 60 nm; and/or an oil absorption number OAN when measured according to ASTM D-2414 of less than 400 ml.Math.g.sup.1.
14. The composition according to claim 11, wherein the composition comprises carbon black and expanded graphite in a combined amount of 10 to 50 wt.-% based on the total weight of the composition.
15. The composition according to claim 6 comprising one or more fillers selected from the group consisting of metal powder, metal flakes, glass fibers, silicon fibers, carbon-based fillers selected from the group consisting of carbon conductive additives, natural graphite, synthetic graphite, surface modified graphite, graphite nanoplatelets, multiwall carbon nanotubes, single wall carbon nanotube, carbon nanostructures, metal-coated graphite, and combinations thereof.
16. The composition according to claim 6 comprising a polymer.
17. A shaped article of composite material comprising the composition according to claim 16.
18-19. (canceled)
20. The shaped article of claim 17, wherein the carbon black and the expanded graphite are dispersed in the polymer.
21. (canceled)
22. Method of providing electromagnetic interference (EMI) shielding measured according to ASTM D-4935 at a frequency of 10 MHz to 1000 MHz in a polymeric composition using the composition of claim 6, wherein the EMI shielding is at least 20 dB.
23. Method of providing volume resistivity when measured according to standard test method ASTM D-4496 in a polymeric composition using the composition of claim 6, wherein the volume resistivity is less than 1000 Ohm.Math.cm.
24. Method of providing in-plane thermal conductivity measured according to ASTM E 1461 in a polymeric composition using the composition of claim 6, wherein the thermal conductivity is greater than 0.5 W.Math.m.sup.1K.sup.1.
25. The method of providing electromagnetic interference (EMI) shielding of claim 22, wherein the EMI shielding is improved by at least 10 dB when compared to a reference material not comprising a composition according to claim 6.
26. The method of providing volume resistivity of claim 23, wherein the volume resistivity is reduced by a factor of 1.3 to 10.sup.9 when compared to a reference material not comprising a composition according to claim 6.
27. The method of providing thermal conductivity of claim 24, wherein the thermal conductivity is increased by a factor of 2 when compared to a reference material not comprising composition according to claim 6&.
28. The composition according to claim 6, wherein the carbon black is characterized by a BET specific surface area measured according to ASTM D-3037 under nitrogen of less than 850 m.sup.2.Math.g.sup.1.
29. The composition according to claim 6, wherein the expanded graphite is characterized by one or more of the following: a particle size distribution D.sub.90 when measured according to ISO 13220 of 20 to 800 m; and/or a bulk density when measured according to ASTM D-7481 standard of 0.02 to 0.9 g.Math.cm.sup.3.
Description
BRIEF DESCRIPTION OF THE FIGURES
[0029]
[0030]
[0031]
[0032]
[0033]
[0034]
[0035]
[0036]
[0037]
[0038]
[0039]
DETAILED DESCRIPTION OF THE INVENTION
Definitions
[0040] In context of the present invention, the term electrical resistivity sometimes also referred to as electrical resistivity, , volume resistivity or specific electrical resistance, is a material property related to the degree of the material's resistance to electric current expressed in the SI units Ohm.Math.m or Ohm.Math.cm (.Math.m or .Math.cm, respectively). Volume resistivity is usually determined according to ASTM D-4496 standard test method. A low-resistivity material is a material which readily conducts electric current.
[0041] In context of the present invention, the term thermal conductivity refers to a material property quantifying a material's ability to conduct heat expressed in the SI units W.Math.m.sup.1.Math.K.sup.1 or W.Math.cm.sup.1.Math.K.sup.1. A material having high thermal conductivity is very efficient at conducting heat. A material's thermal conductivity is commonly determined by standard tests according to ASTM E 1461 or ISO 22007. Thermal conductivity can be measured in in-plane and through-plane mode.
[0042] In context of the present invention, the term electromagnetic interference (EMI) is a physical phenomenon that occurs when an external source affects an electrical circuit by electromagnetic induction, electrostatic coupling or conduction. EMI perturbs or even completely degrades the performance of an electric circuit. Correspondingly, in context of the present invention, the term electromagnetic interference shielding refers to a material's ability to reduce or even completely eliminate the negative impact of EMI on electric circuits. In this regard, in the context of the present invention, the term EMI shielding efficiency (EMI SE) refers to a material's EMI shielding performance, commonly expressed as the attenuation in decibel (dB) of an electromagnetic wave at a certain frequency. EMI SE can for example be determined by standard tests according to ASTM D-4935 at a specific frequency range or methods derived therefrom. In context of the present invention, EMI SE is measured according to ASTM D-4935 at a frequency of 10 to 1000 MHz or method derived therefrom as detailed in the paper E. Hariya and U. Massahiro, Instruments for Measuring Shielding Effectiveness, EMC 1984 Tokyo.
[0043] In context of the present invention, the terms conductive additive and conductive filler are used interchangeably and refer to materials that are added to a polymer, e.g. a compounding composition, polymer binder or a resin, to provide thermal and/or electrical conductivity to the polymer. Conductive additive or conductive fillers are known to the skilled person and can be, for example, carbonaceous or metal-based or hybrid materials in various forms such as powders, fibers, or flakes.
Aspects of the Invention
[0044] In a first aspect, the present invention provides a composition comprising carbon black and expanded graphite. The composition of the invention is characterized by one or more of the following:
[0045] The composition of the present invention comprises carbon black in an amount of 3 to 40, preferably 5 to 35, more preferably 10 to 30, even more preferably 12 to 26, most preferably 13 to 18 wt.-% based on the total weight of the composition.
[0046] The composition of the present invention comprises expanded graphite in an amount of 3 to 50, preferably 3 to 40, more preferably 3 to 35, even more preferably 3 to 30, still more preferably 3.5 to 20, in particular more preferably 4 to 18, in particular still more preferably 5 to 17, most preferably 7 to 15 wt.-% based on the total weight of the composition.
[0047] The composition comprises carbon black and expanded graphite in a combined amount of 10 to 50, preferably 17 to 45, more preferably 19 to 40, even more preferably 20 to 35, still more preferably 22 to 34, in particular more preferably 24 to 31, most preferably 25 to 30 wt.-% based on the total weight of the composition.
[0048] The ratio of wt.-% based on the total weight of the composition of carbon black to expanded graphite in the composition of the present invention is in the range of 0.1 to 9, preferably 0.33 to 9, more preferably 0.4 to 9, even more preferably 0.4 to 7, still more preferably 0.4 to 5, in particular more preferably 0.4 to 3, in particular still more preferably 0.4 to 2, most preferably 0.6 to 1.7.
[0049] The composition of the present invention comprises carbon black characterized by a BET specific surface area measured according to ASTM D3037 under nitrogen of less than 950 m.sup.2.Math.g.sup.1, preferably less than 850 m.sup.2.Math.g.sup.1, more preferably less than 700 m.sup.2.Math.g.sup.1, even more preferably less than 600 m.sup.2.Math.g.sup.1, most preferably less than 500 m.sup.2.Math.g.sup.1, in particular in the range of 40 to 800, preferably 50 to 800, more preferably 30 to 100, even more preferably 50 to 80, most preferably 60 to 70 m.sup.2.Math.g.sup.1 and, optionally, one or more of a primary particle size measured according to ASTM D3849-14a of 10 to 60, preferably 15 to 55, more preferably 20 to 40, even more preferably 25 to 35 nm; and/or an oil absorption number OAN when measured according to ASTM D-2414 of less than 400 ml.Math.g.sup.1, preferably less than 390 ml.Math.g.sup.1, more preferably less than 380 ml.Math.g.sup.1, even more preferably less than 370 ml.Math.g.sup.1, most preferably less than 350 ml.Math.g.sup.1, in particular in the range of 100 to 330, preferably 150 to 230, more preferably 170 to 210, even more preferably 180 to 200, most preferably 185 to 195 ml.Math.g.sup.1.
[0050] The composition of the present invention comprises expanded graphite characterized by one or more of a particle size distribution D.sub.90 when measured according to ISO 13220 of 5 to 1000, preferably 20 to 800, more preferably 30 to 700, even more preferably 50 to 600, still more preferably 70 to 500, in particular more preferably 80 to 250, most preferably 85 to 150 m and/or a bulk density when measured according to ASTM D-7481 of 0.01 to 1.00, preferably 0.02 to 0.9, more preferably 0.05 to 0.7, even more preferably 0.1 to 0.55, still more preferably 0.13 to 0.50, in particular more preferably 0.16 to 0.45, most preferably 0.16 to 0.25 g.Math.cm.sup.3.
[0051] In a preferred embodiment, the composition of the present invention comprises (a) carbon black in an amount of 3 to 40, preferably 5 to 35, more preferably 10 to 30, even more preferably 12 to 26, most preferably 13 to 18 wt.-% based on the total weight of the composition; and (b) expanded graphite in an amount of 3 to 50, preferably 3 to 40, more preferably 3 to 35, even more preferably 3 to 30, still more preferably 3.5 to 20, in particular more preferably 4 to 18, in particular still more preferably 5 to 17, most preferably 7 to 15 wt.-% based on the total weight of the composition.
[0052] In another preferred embodiment, the composition of the present invention comprises (a) carbon black; and (b) expanded graphite, wherein the carbon black is characterized by a BET specific surface area measured according to ASTM D3037 under nitrogen of less than 950 m.sup.2.Math.g.sup.1, preferably less than 850 m.sup.2.Math.g.sup.1, more preferably less than 700 m.sup.2.Math.g.sup.1, even more preferably less than 600 m.sup.2.Math.g.sup.1, most preferably less than 500 m.sup.2.Math.g.sup.1, in particular in the range of 40 to 800, preferably 50 to 800, more preferably 30 to 100, even more preferably 50 to 80, most preferably 60 to 70 m.sup.2.Math.g.sup.1 and, optionally, one or more of a primary particle size measured according to ASTM D3849-14a of 10 to 60, preferably 15 to 55, more preferably 20 to 40, even more preferably 25 to 35 nm; and/or an oil absorption number OAN when measured according to ASTM D-2414 of less than 400 ml.Math.g.sup.1, preferably less than 390 ml.Math.g.sup.1, more preferably less than 380 ml.Math.g.sup.1, even more preferably less than 370 ml.Math.g.sup.1, most preferably less than 350 ml.Math.g.sup.1, in particular in the range of 100 to 330, preferably 150 to 230, more preferably 170 to 210, even more preferably 180 to 200, most preferably 185 to 195 ml.Math.g.sup.1 and/or wherein the expanded graphite characterized by one or more of a particle size distribution D90 when measured according to ISO 13220 of 5 to 1000, preferably 20 to 800, more preferably 30 to 700, even more preferably 50 to 600, still more preferably 70 to 500, in particular more preferably 80 to 250, most preferably 85 to 150 m and/or a bulk density when measured according to ASTM D-7481 of 0.01 to 1.00, preferably 0.02 to 0.9, more preferably 0.05 to 0.7, even more preferably 0.1 to 0.55, still more preferably 0.13 to 0.50, in particular more preferably 0.16 to 0.45, most preferably 0.16 to 0.25 g.Math.cm.sup.3.
[0053] In yet another preferred embodiment, the composition of the present invention comprises carbon black and expanded graphite, wherein the ratio of wt.-% based on the total weight of the composition of carbon black to graphite is in the range of 0.1 to 9, preferably 0.33 to 9, more preferably 0.4 to 9, even more preferably 0.4 to 7, still more preferably 0.4 to 5, in particular more preferably 0.4 to 3, in particular still more preferably 0.4 to 2, most preferably 0.6 to 1.7 and wherein the carbon black is characterized by a BET specific surface area measured according to ASTM D-3037 under nitrogen of less than 950 m.sup.2.Math.g.sup.1, preferably less than 850 m.sup.2.Math.g.sup.1, more preferably less than 700 m.sup.2.Math.g.sup.1, even more preferably less than 600 m.sup.2.Math.g.sup.1, most preferably less than 500 m.sup.2.Math.g.sup.1, in particular in the range of 40 to 800, preferably 50 to 800, more preferably 30 to 100, even more preferably 50 to 80, most preferably 60 to 70 m.sup.2.Math.g.sup.1; and optionally, one or more of a primary particle size measured according to ASTM D-3849-14a of 10 to 60, preferably 15 to 55, more preferably 20 to 40, even more preferably 25 to 35 nm; and/or an oil absorption number OAN when measured according to ASTM D-2414 of less than 400 ml.Math.g.sup.1, preferably less than 390 ml.Math.g.sup.1, more preferably less than 380 ml.Math.g.sup.1, even more preferably less than 370 ml.Math.g.sup.1, most preferably less than 350 ml.Math.g.sup.1, in particular in the range of 100 to 330, preferably 150 to 230, more preferably 170 to 210, even more preferably 180 to 200, most preferably 185 to 195 ml.Math.g.sup.1 and/or wherein the expanded graphite is characterized by one or more of a particle size distribution D.sub.90 when measured according to ISO 13220 of 5 to 1000, preferably 20 to 800, more preferably 30 to 700, even more preferably 50 to 600, still more preferably 70 to 500, in particular more preferably 80 to 250, most preferably 85 to 150 m and/or a bulk density when measured according to ASTM D-3037 of 0.01 to 1.00, preferably 0.02 to 0.9, more preferably 0.05 to 0.7, even more preferably 0.1 to 0.55, still more preferably 0.13 to 0.50, in particular more preferably 0.16 to 0.45, most preferably 0.16 to 0.25 g.Math.cm.sup.3.
[0054] In other preferred embodiments, it is also provided, that compositions according to the present invention comprise one or more fillers selected from the group consisting of metal powder, metal flakes, glass fibers, silicon fibers, carbon-based fillers selected from the group consisting of carbon conductive additives, natural graphite, synthetic graphite, surface modified graphite, graphite nanoplatelets, multiwall carbon nanotubes, single wall carbon nanotube, carbon nanostructures, metal-coated graphite, and combinations thereof. Such fillers may be used to optimize and fine tune chemical and physical properties of the compositions.
[0055] In other preferred embodiments, it is also provided, that the compositions comprise a polymer, preferably, the polymer being selected from the from the group consisting of polyolefins, preferably the polyolefins being selected from polyethylene, polypropylene and combinations thereof, more preferably the polyolefins are polypropylene, polyamides, polymethylmethacrylate (PMMA), polyacetal, polycarbonate, polyvinyls, polyacrylonitrile, polybutadiene, polystyrene, polyacrylate, epoxy polymers, polyesters, polycarbonates, polyketones, polysulfones, unsaturated polyesters, polyurethanes, polycyclopentadienes, silicones, rubber, thermosets, thermoplastics, binders for coating and combinations thereof. This way, the composition of the present invention can be applied to a broad spectrum of polymers.
[0056] In a second aspect, the present invention provides a shaped article of composite material comprising the composition according to the invention as described hereinabove.
[0057] In a third aspect, the present invention provides a substrate coated with a coating comprising the composition of the invention.
[0058] The shaped article or the coating for the substrate of the present invention can comprise a polymer selected from the group consisting of polyolefins, preferably the polyolefins being selected from polyethylene, polypropylene and combinations thereof, more preferably the polyolefins are polypropylene, polyamides, polymethylmethacrylate (PMMA), polyacetal, polycarbonate, polyvinyls, polyacrylonitrile, polybutadiene, polystyrene, polyacrylate, epoxy polymers, polyesters, polycarbonates, polyketones, polysulfones, unsaturated polyesters, polyurethanes, polycyclopentadienes, silicones, rubber, thermosets, thermoplastics, binders for coating and combinations thereof.
[0059] In preferred embodiments of the shaped article or the coating for the substrate of the present invention, the carbon black and the expanded graphite are dispersed in the polymer. This provides for equal distribution of the conductive additives in the polymer and provides for particular good effects like EMI shielding efficiency or thermal conductivity.
[0060] In a fourth aspect, the present invention provides for use of the composition, the shaped article or the coated substrate according to the invention as described hereinabove for providing one or more of electro-magnetic interference (EMI) shielding measured according to ASTM D-4935 at a frequency of 10 to 1000 MHz or method derived therefrom as detailed in the paper E. Hariya and U. Massahiro, Instruments for Measuring Shielding Effectiveness, EMC 1984 Tokyo, wherein the EMI shielding is at least 20 dB, preferably at least 30 dB, more preferably at least 40 dB; volume resistivity measured according to ASTM D-4496, wherein the volume resistivity is less than 1000 Ohm.Math.cm, preferably less than 100 Ohm.Math.cm, more preferably less than 10 Ohm.Math.cm, most preferably less than 1 Ohm.Math.cm; and/or in-plane thermal conductivity measured according to ASTM E 1461, wherein the inplane thermal conductivity is greater than 0.5 W.Math.m.sup.1K.sup.1, preferably greater than 0.7 W.Math.m.sup.1K.sup.1, more preferably greater than 0.9 W.Math.m.sup.1K.sup.1, in particular more preferably greater than 1.1 W.Math.m.sup.1K.sup.1, even more preferably greater than 1.3 W.Math.m.sup.1K.sup.1, still more preferably greater than 1.5 W.Math.m.sup.1K.sup.1, in particular still more preferably greater than 1.7 W.Math.m.sup.1K.sup.1, still more preferably greater than 2.0 W.Math.m.sup.1K.sup.1, still more preferably greater than 2.5 W.Math.m.sup.1K.sup.1, even more preferably greater than 3.0 W.Math.m.sup.1K.sup.1, in particular even more preferably greater than 4.0 W.Math.m.sup.1K.sup.1, in particular still more preferably greater than 5.0 W.Math.m.sup.1K.sup.1, still more preferably greater than 6.0 W.Math.m.sup.1K.sup.1, most preferably greater than 7.0 W.Math.m.sup.1K.sup.1.
[0061] In a fifth aspect, the present invention provides for a method of providing electromagnetic interference (EMI) shielding measured according to standard test method ASTM D-4935 at a frequency of 10 MHz to 1000 MHz or method derived therefrom as detailed in the paper E. Hariya and U. Massahiro, Instruments for Measuring Shielding Effectiveness, EMC 1984 Tokyo in a polymeric composition using the composition, the shaped article or the coated substrate according to the invention as described hereinabove, wherein the EMI shielding is at least 20 dB, preferably at least 30 dB, more preferably at least 40 dB.
[0062] In a sixth aspect, the present invention provides for a method of providing volume resistivity when measured according to standard test method ASTM D-4496 in a polymeric composition using the composition, the shaped article or the coated substrate according to the invention as described hereinabove, wherein the volume resistivity is less than 1000 Ohm.Math.cm, preferably less than 100 Ohm.Math.cm, more preferably less than 10 Ohm.Math.cm, most preferably less than 1 Ohm.Math.cm.
[0063] In a seventh aspect, the present invention provides for a method of providing in-plane thermal conductivity measured according to ASTM E 1461 in a polymeric composition using the composition, the shaped article or the coated substrate according to the invention as described hereinabove, wherein the inplane thermal conductivity is greater than 0.5 W.Math.m.sup.1K.sup.1, preferably greater than 0.7 W.Math.m.sup.1K.sup.1, more preferably greater than 0.9 W.Math.m.sup.1K.sup.1, in particular more preferably greater than 1.1 W.Math.m.sup.1K.sup.1, even more preferably greater than 1.3 W.Math.m.sup.1K.sup.1, still more preferably greater than 1.5 W.Math.m.sup.1K.sup.1, in particular still more preferably greater than 1.7 W.Math.m.sup.1K.sup.1, still more preferably greater than 2.0 W.Math.m.sup.1K.sup.1, still more preferably greater than 2.5 W.Math.m.sup.1K.sup.1, even more preferably greater than 3.0 W.Math.m.sup.1K.sup.1, in particular even more preferably greater than 4.0 W.Math.m.sup.1K.sup.1, in particular still more preferably greater than 5.0 W.Math.m.sup.1K.sup.1, still more preferably greater than 6.0 W.Math.m.sup.1K.sup.1, most preferably greater than 7.0 W.Math.m.sup.1K.sup.1.
[0064] In further preferred embodiments, the use or the method of providing electromagnetic interference (EMI) shielding of the present invention improve EMI shielding by at least 10 dB, preferably at least 20 dB, more preferably at least 25 dB, even more preferably at least 30 dB, still more preferably at least 35 dB, in particular more preferably at least 40 dB, most preferably at least 45 dB, in particular by 10 to 80 dB, preferably 15 to 70 dB, more preferably 18 to 60 dB, in particular more preferably 20 to 55 dB, even more preferably 25 to 50 dB, in particular even more preferably 27 to 50 dB, still more preferably 30 to 50 dB, in particular still more preferably 31 to 45 dB, most preferably 35 to 42 dB when compared to a reference material not comprising carbon black, expanded graphite or any other conductive filler or additive, in particular a composition according to the invention as described hereinabove.
[0065] In further preferred embodiments, the use or the method of providing volume resistivity of the present invention reduce volume resistivity by a factor of 1.3 to 109, preferably 1.5 to 108, more preferably 2 to 107, in particular preferably 2 to 106, even more preferably 2 to 105, in particular even more preferably 3 to 105, still more preferably 3 to 104, in particular still more preferably 5 to 104, even more preferably 7 to 104, still more preferably 7 to 103, in particular even more preferably 10 to 103, in particular still more preferably 15 to 103, even more preferably 50 to 103, most preferably 102 to 103 when compared to a reference material not comprising carbon black, expanded graphite or any other conductive filler or additive, in particular a composition according to the invention as described hereinabove.
[0066] In further preferred embodiments, the use or the method of providing in-plane thermal conductivity of the present invention increase in-plane thermal conductivity by a factor of 2, preferably 3, more preferably 4, in particular preferably 5, even more preferably 6, in particular even more preferably 7, still more preferably 8, in particular still more preferably 9, still more preferably 10, even more preferably 12, in particular still more preferably 14, in particular even more preferably 16, still more preferably 18, even more preferably 20, in particular still more preferably 25, in particular still more preferably 30, even more preferably 40, most preferably 50 when compared to a reference material not comprising carbon black, expanded graphite or any other conductive filler or additive, in particular a composition according to the invention as described hereinabove.
[0067] In summary, the subject matter of the present invention as described hereinabove advantageously allows to optimize both the amount of conductive additives and desired properties of compositions such as electrical conductivity, EMI shielding efficiency and in-plane thermal conductivity without compromising rheological and mechanical properties.
[0068] It is intended that all matter contained in the above description should be interpreted as illustrative and not in a limiting sense. Thus, certain changes may be made in the compositions, uses and methods described above without departing from the scope of the present invention.
[0069] The invention will be further described by the following examples which illustrate the preparation of compositions and their corresponding properties, without limiting the invention.
EXAMPLES
Materials Used:
Polymers:
[0070] Polypropylene, commercially available as PP 412 MN40; [0071] Polyamide, commercially available as Technyl C246.
Additives:
[0072] Conductive Carbon Black, commercially available as Ensaco 250G from Imerys characterized by an oil absorption number (OAN) of 190 mL/100 g and a BET specific surface area under nitrogen of 65 m.sup.2/g; [0073] Extra-Conductive Carbon Black, commercially available as Ensaco 350G from Imerys characterized by an OAN of 320 mL/100 g and a BET specific surface area under nitrogen of 770 m.sup.2/g; [0074] Expanded graphite (high aspect ratio graphite), commercially available as Timrex C-THERM 011 from Imerys characterized by a particle size distribution of D.sub.90=90 m; [0075] Expanded graphite (high aspect ratio graphite), commercially available as Timrex C-THERM 301 from Imerys characterized by a particle size distribution of D.sub.90=30 m; [0076] Expanded graphite (high aspect ratio graphite), commercially available as Timrex C-THERM MAX HD from Imerys characterized by a particle size distribution of D.sub.90>400 m; [0077] Synthetic graphite (low aspect ratio primary synthetic graphite), commercially available as Timrex SFG44 from Imerys characterized by a BET specific surface area of ca. 5 m.sup.2/g and a particle size distribution of D.sub.90=50 m; [0078] Synthetic graphite (low aspect ratio primary synthetic graphite), commercially available as Timrex KS44 from Imerys characterized by a BET specific surface area under nitrogen of ca. 9 m.sup.2/g and a particle size distribution of D.sub.90=46 m [0079] Carbon fiber, commercially available as Tenax A HT P802 3 mm from Teijin characterized by a fiber diameter of 7 m and a pellet length of 8 mm.
Methods and Equipment Used:
[0080] The melt flow rate (MFR) is measured via a Melt Flow Tester, CEAST according to norm ISO 1133 at 5 kg and 230 C. Other conditions used for the MFR measurements are indicated.
[0081] The volume resistivity is measured using a Loresta GX device from Nittoseiko-Mitsubishi, using the 4 points ASP Probe according to norm ASTM D4496.
[0082] EMI shielding was tested on 2.3-2.4 mm thick compressed plaques (150150 mm.sup.2 size) at frequencies in the range from 10 MHz to 1 GHz according to the TEM t cell method which is derived from ASTM D 4935 (details to be found in the paper E. Hariya and U. Massahiro, Instruments for Measuring Shielding Effectiveness, EMC 1984 Tokyo). For all samples having attenuation above 25 dB, a correction factor corresponding to the theoretical value of the empty TEM t cell as derived from the equivalent circuit was applied.
[0083] The thermal conductivity is measured using Laser Flash LFA 447 from Netzsch according to norm ASTM E 1461 at a temperature of 23 C. The measurements are made both in-plane and through-plane direction with regard to the material flow during the plaque filling stage.
[0084] The tensile properties are measured with an Instron Dynamometer 5966 according to ISO 527.
Tested Formulations:
A) Compositions with Polypropylene (PP)
A-1) PP Compositions with Blends of CB and EG
[0085] The polypropylene compositions listed in Table 1.1 were prepared with a final loading of conductive additives of 30 wt.-% based on the total weight of the composition with different blends of carbon black (Ensaco 250G from Imerys with OAN=190 mL/g and BET specific surface area under nitrogen of 65 m.sup.2/g) and expanded graphite (Timrex C-THERM 011 from Imerys with D.sub.90=90 m)
TABLE-US-00001 TABLE 1.1 Samples with polypropylene and a conductive additive loading (filler loading) of 30 wt.-% with different blends of carbon black and expanded graphite. CB.sup.1)/ EG.sup.2)/ Sample wt.-% %* wt.-% %* CB.sup.1):EG.sup.2)# PP-1 30 100 0 PP-2 26.2 87.3 3.8 12.7 6.9 PP-3 22.5 75 7.5 25 3 PP-4 18.7 62 11.3 38 1.65 PP-5 15 50 15 50 1 PP-6 11.3 38 18.7 62 0.6 PP-7 7.5 25 22.5 75 0.33 PP-8 3.8 12.7 26.2 87.3 0.15 PP-9 0 30 100 *% of total filler content; .sup.#wt.-% ratio of carbon black (CB) and expanded graphite (EG) .sup.1)Carbon black = Ensaco 250G from Imerys with OAN = 190 mL/g and BET specific surface area under nitrogen of 65 m.sup.2/g; .sup.2)Expanded graphite = Timrex C-THERM 011 from Imerys with D.sub.90 = 90 m;
A-2) PP Compositions with Further Blends of Conductive Fillers
[0086] For comparative tests, formulations with a final loading of conductive additives of 30 wt.-% based on the total weight of the composition (with the exception of sample PP-12 which only has 22.5 wt.-% based on the total weight of the composition) with different blends of different kinds of carbon black (Ensaco 250G from Imerys with OAN=190 mL/g and BET specific surface area under nitrogen of 65 m.sup.2/g, or Ensaco 350G from Imerys with OAN of 320 mL/100 g and BET specific surface area under nitrogen of 770 m.sup.2/g) and different kinds of expanded graphite (Timrex C-THERM Oil from Imerys with D.sub.90=90 m or Timrex C-THERM 301 from Imerys with D.sub.90=30 m or Timrex C-THERM MAX HD from Imerys with D.sub.90>400 m; see samples PP-10 to PP-12), optionally with carbon fibers (Tenax A HT P802 3 mm from Teijin with fiber diameter of 7 m and pellet length of 8 mm) as additional conductive additives (samples PP-13 to PP-14) were prepared, see Table 1.2.
TABLE-US-00002 TABLE 1.2 Samples with further blends of conductive fillers. EG and/or CB/ CF/ wt.-% Resistivity.sup./ Sample wt.-% %* wt.-% %* ratio.sup.# Ohm .Math. cm PP-10 15.sup.1) 50 15.sup.3) 50 1 1.37 .Math. E0 PP-11 15.sup.1) 50 15.sup.4) 50 1 2.13 .Math. E0 PP-12.sup. 7.5.sup.5) 0.33 15.sup. .sup.0.67.sup. 2 3.13 .Math. E0 PP-13 15.sup.1) 50 15 (CF) .sup.6) 50 1 0.41 .Math. E0 PP-14 10.sup.1) 0.33 10.sup.2) 0.33 1 1.99 .Math. E0 10 (CF) .sup.6) 0.33 *% of total filler content; .sup.#wt-% ratio of carbon black (CB) to: i) expanded graphite (EG) or ii) EG + carbon fiber (CF) or iii) CF alone; .sup.Resistivity expressed as average of parallel and perpendicular mode measurements; .sup.Total amount of filler for sample PP-12 = 22. 5 wt.-%; .sup.1)Carbon black = Ensaco 250G from Imerys with OAN = 190 mL/g and BET specific surface area under nitrogen of 65 m.sup.2/g; .sup.2)Expanded graphite = Timrex C-THERM 011 from Imerys with D.sub.90 = 90 m; .sup.3)Expanded graphite = Timrex C-THERM 301 from Imerys with D.sub.90 = 30 m; .sup.4)Expanded graphite = Timrex C-THERM MAX HD from Imerys with D.sub.90 > 400 m; .sup.5)Carbon black = extra-conductive carbon black Ensaco 350G from Imerys with OAN of 320 mL/100 g and BET specific surface area under nitrogen of 770 m.sup.2/g; total loading of conductive additives only 22.5 wt.-% based on the total weight of the composition; .sup.6) Carbon fiber (CF) = Tenax A HT P802 3 mm from Teijin with fiber diameter of 7 m and pellet length of 8 mm.
A-3) PP Compositions with Blends of CB and Synthetic Graphite
[0087] For comparative tests, formulations with a final loading of conductive additives of 30 wt.-% based on the total weight of the composition with different blends of carbon black (Ensaco 250G from Imerys with OAN=190 mL/g and BET specific surface area under nitrogen of 65 m.sup.2/g) and synthetic graphite (Timrex SFG44 Primary Synthetic Graphite from Imerys characterized by a BET specific surface area of ca. 5 g/m.sup.2 and a particle size distribution of D.sub.90=50 m) were prepared, see Table 1.3.
TABLE-US-00003 TABLE 1.3 Samples for comparative tests with synthetic graphite (SG) instead of expanded graphite (EG). CB.sup.1)/ SG.sup.2)/ Sample wt.-% %* wt.-% %* CB.sup.1):SG.sup.2)# PP-15 15 50 15 50 1 PP-16 7.5 25 22.5 75 0.33 PP-17 0 0 30 100 0 .sup.1)Carbon black = Ensaco 250G from Imerys with OAN = 190 mL/g and BET specific surface area under nitrogen of 65 m.sup.2/g; .sup.2)Synthetic graphite = Timrex SFG44 Primary Synthetic Graphite from Imerys with BET specific surface area of ca. 5 m.sup.2/g and D.sub.90 = 50 m; *% of total filler content; .sup.#wt.-% ratio of carbon black (CB) and expanded graphite (SG)
B) Compositions with Polyamide (PA)
[0088] The polyamide compositions listed in Table 2 were prepared with different final loadings of conductive additives and with different single component additives or blends of carbon black (Ensaco 250G from Imerys with OAN=190 mL/g and BET specific surface area under nitrogen of 65 m.sup.2/g) and expanded graphite (Timrex C-THERM 011 from Imerys with D90=90 m). For comparative tests, formulations with synthetic graphite (Timrex KS44 from Imerys with a BET specific surface area under nitrogen of ca. 9 m.sup.2/g and D.sub.90=46 m) were prepared.
TABLE-US-00004 TABLE 2 Samples for polyamide compositions with conductive fillers of single-component additives and binary blends of carbon black and expanded graphite. Total amount filler/ Sample Filler type wt.-% PA-1 CB.sup.1) 5 PA-2 10 PA-3 15 PA-4 20 PA-5 EG.sup.2) 5 PA-6 10 PA-7 15 PA-8 20 PA-9 30 PA-10 SG.sup.3) 10 PA-11 20 PA-12 30 PA-13 Blend of 25 CB.sup.1) + EG.sup.2) (12.5 CB + 12.5 EG) .sup.1)Carbon black = Ensaco 250G from Imerys with OAN = 190 mL/g and BET specific surface area under nitrogen of 65 m.sup.2/g; .sup.2)Expanded graphite = Timrex C-THERM 011 from Imerys with D.sub.90 = 90 m; .sup.3)Synthetic graphite = Timrex KS44 from Imerys with a BET specific surface area under nitrogen of ca. 9 m.sup.2/g and D.sub.90 = 46 m.
Example 1: Preparation of the Composites
[0089] Samples PP-1 through PP-17 and PA-1 through PA-13 described above are used as composites in at least some of the following examples, and the composites in the following examples are prepared by melt extrusion using a twin screw extruder, Leistritz ZSE 27 mm, with an L/D ratio of 48, equipped with two side feeders. The polymer melt temperature is set at 240 C., the screw speed are fixed at 200 rpm and the total output is 15 kg/h. The Polypropylene, Sabic, PP 412 MN40, is added in the main feeder. The conductive additives are added in the polymer melt using one or two side feeders fed by gravimetric feeders. The composites are extruded via a die, cooled down via water batch, granulated using rotating and cutting blades.
Example 2: Preparation of the Test Specimen (Plaques)
[0090] The samples for volume resistivity, mechanical tests, and thermal conductivity are prepared by injection molding using a Billion Proxima 50T.
[0091] The samples for EMI shielding tests are compressed using a LabTech press LPS20. Plaques of 1501502.4 mm.sup.2 are prepared.
Example 3: Measurement of the Viscosity (MFI)
[0092] The inventors of the present invention found that blends of carbon black and expanded graphite according to the present invention advantageously provide for acceptable rheologic properties:
3.1. Viscosity (MFI) Data for Polypropylene Compositions
TABLE-US-00005 TABLE 3.1 Viscosity (MFI) data for polypropylene compositions with blends of carbon black and expanded graphite (samples PP-3.1 to PP-3.5) and compositions with blends of different kinds of carbon black and different kinds of expanded graphite, optionally with carbon fibers as additional conductive additives (samples PP-3.6 to PP-3.10), also see FIG. 1. Viscosity (MFI)/ g/10 min) CB/ EG/ wt.-% @ 230 C./ Sample wt.-% %* wt.-% %* ratio .sup.# 5 kg Ctrl. 0.sup. 0.sup. 37.sup.) PP-3.1 30 .sup.1) 100 0.sup. 0.2 PP-3.2 22.5.sup.1) 75 7.5 .sup.2) 25 3 0.5 PP-3.3 15 .sup.1) 50 15 .sup.2) 50 1 1.4 PP-3.4 7.5 .sup.1) 25 22.5.sup.2) 75 0.33 2.2 PP-3.5 0.sup. 30 .sup.2) 100 5.4 PP-3.6 15 .sup.1) 50 15 .sup.3) 50 1 1.5 PP-3.7 15 .sup.1) 50 15 .sup.4) 50 1 8.2 PP-3.8.sup. 7.5 .sup.5) 33 15 .sup.2) 67 1 5.2 PP-3.9 15 .sup.1) 50 15.sup. 50 13.8 (CF) .sup.6) PP- 10 .sup.1) 33 10 .sup.2) 0.33 1 7.6 3.10.sup.7) 10.sup. 0.33 (CF) .sup.6) *% of total filler content; .sup.# wt.-% ratio of carbon black (CB) to: i) expanded graphite (EG) or ii) EG + carbon fiber (CF) or iii) CF alone; .sup.Total amount of filler for sample PP-3.8 = 22.5 wt.-%; .sup.)measured at 230 C./2.16 kg; .sup.1) Carbon black = Ensaco 250G from Imerys with OAN = 190 mL/g and BET specific surface area under nitrogen of 65 m.sup.2/g; .sup.2) Expanded graphite = Timrex C-THERM 011 from Imerys with D.sub.90 = 90 m; .sup.3) Expanded graphite = Timrex C-THERM 301 from Imerys with D.sub.90 = 30 m; .sup.4) Expanded graphite = Timrex C-THERM MAX HD from Imerys with D.sub.90 > 400 m; .sup.5) Carbon black = extra-conductive carbon black Ensaco 350G from Imerys with OAN of 320 mL/100 g and BET specific surface area under nitrogen of 770 m.sup.2/g; total loading of conductive additives only 22.5 wt.-% based on the total weight of the composition; .sup.6) Carbon fiber = Tenax A HT P802 3 mm from Teijin with fiber diameter of 7 m and pellet length of 8 mm. .sup.7)Conductive additives = 10 wt.-% CB (Ensaco 250G), 10 wt.-% EG (Timrex C-THERM 011), 10 wt.-% carbon fiber (Tenax A HT P802).
[0093] From the data presented in Table 3.1 and
[0094] Also, from comparing samples PP-3.3, PP-3.6, and PP-3.7 with CB:EG-ratios of 1 with different types of expanded graphite it can be derived that expanded graphite Timrex C-THERM 011 from Imerys with D.sub.90=90 m provides for the lowest MFI (highest viscosity) in blends with Ensaco 250 G carbon black.
[0095] Further, conductive additive blends with carbon fiber provide for lower viscosities (higher MFI) than blends without carbon fiber.
3.2. Viscosity (MFI) Data for Polyamide Compositions
TABLE-US-00006 TABLE 3.2 Viscosity (MFI) data for polyamide compositions with conductive fillers of single-component additives and binary blends of carbon black and expanded graphite, also see FIG. 2A and FIG. 2B. Total amount Viscosity (MFI)/ of filler/ g/10 min Sample Filler type wt.-% @ 240 C./5 kg Ctrl. 0 17.63 PA-3.1 CB.sup.1) 5 13.72 PA-3.2 10 5.81 PA-3.3 15 1.17 PA-3.4 EG.sup.2) 5 10.76 PA-3.5 10 6.59 PA-3.6 15 4.13 PA-3.7 20 1.20 PA-3.8 30 0.27 PA-3.9 SG.sup.3) 10 13.60 PA-3.10 20 10.23 PA-3.11 30 5.92 Total amount Viscosity (MFI)/ of filler/ g/10 min Sample Filler type wt.-% @ 240 C./10 kg PA-3.12 CB.sup.1) 20 2.31 PA-3.13 Blend of 25 1.45 CB.sup.1) + EG.sup.2) (12.5 CB:12.5 EG) Total amount Viscosity (MFI)/ of filler/ g/10 min Sample Filler type wt.-% @ 240 C./12.5 kg PA-3.14 CB.sup.1) 20 4.58 PA-3.15 30 0.39 PA-3.16 EG.sup.2) 20 19.40 PA-3.17 30 9.04 PA-3.18 Blend of 25 2.53 CB.sup.1) + EG.sup.2) (12.5 CB + 12.5 EG) .sup.#) wt.-% ratio of carbon black (CB) and expanded graphite (EG); 1.sup.)Carbon black = Ensaco 250G from Imerys with OAN = 190 mL/g and BET specific surface area under nitrogen of 65 m.sup.2/g; .sup.2)Expanded graphite = Timrex C-THERM 011 from Imerys with D.sub.90 = 90 m; .sup.3)Synthetic graphite = Timrex KS44 from Imerys with D.sub.90 = 46 m.
[0096] The inventors of the present invention found that polyamide compositions with more than 10 wt.-% carbon black (Ensaco 250 G) are very viscous and, thus, more difficult to handle compared with polyamide compositions with lower carbon black loadings or other fillers than carbon black such as expanded graphite or synthetic graphite. Against this background, for measuring the viscosity (determined as MFI) of samples PA-3.12 to PA-3.15 and sample PA-3.18) higher sample loadings of 10 and 12.5 kg, respectively, were necessary.
[0097] Also, the inventors of the present invention found that sample PA-3.15 with 30 wt.-% carbon black (Ensaco 250 G) could not be injection molded and that polyamide compositions with 15 wt.-% carbon black (Ensaco 250 G) and 15 wt.-% expanded graphite (Timrex C-THERM 011) could not be extruded any more.
[0098] According to the data presented in Table 3.2 above, at corresponding filler loadings, samples with 10% wt or more expanded graphite show lower viscosity (higher MFI) compared with samples comprising exclusively carbon black at same loading.
Example 4: Measurement of the Volume Resistivity
[0099] The inventors of the present invention found that blends of carbon black and expanded graphite according to the present invention advantageously provide for superior conductivity:
4.1. Volume Resistivity Data for Polypropylene Compositions
[0100] Volume resistivities of polypropylene compositions with blends of carbon black and expanded graphite as conductive additives at an additive loading of 30 wt.-% based on the total weight of the composition were measured (samples PP-4.1 to PP-4.9). For comparative tests, volume resistivities of polypropylene compositions with blends of carbon black and synthetic graphite as conductive additives at an additive loading of 30 wt.-% based on the total weight of the composition were measured (samples PP-4.10 to PP-4.12), see Table 4.1.
TABLE-US-00007 TABLE 4.1 Volume resistivity data for polypropylene compositions with blends of carbon black and expanded graphite (samples PP-4.1 to PP-4.9) and compositions with blends of different kinds of carbon black and different kinds of expanded graphite (samples PP-4.10 to PP-4.12), optionally with carbon fibers as additional conductive additives (samples PP-4.13 to PP-4.14) or with synthetic graphite instead of expanded graphite (samples PP-4.15 to PP-4.17), also see FIG. 3. CB/ EG/ wt.-% Resistivity.sup./ Sample wt.-% %* wt.-% %* ratio .sup.# Ohm .Math. cm Ctrl. 0 0 1.99 .Math. E+14 PP-4.1 30 .sup.1) 100 0 2.30 .Math. E0 PP-4.2 26.2.sup.1) 87.3 3.8 .sup.2) 12.7 6.9 6.67 .Math. E01 PP-4.3 22.5.sup.1) 75 7.5 .sup.2) 25 3 6.68 .Math. E01 PP-4.4 18.7.sup.1) 62 11.3 .sup.2) 38 1.65 6.00 .Math. E01 PP-4.5 15 .sup.1) 50 15 .sup.2) 50 1 9.23 .Math. E01 PP-4.6 11.3.sup.1) 38 18.7 .sup.2) 62 0.6 1.47 .Math. E0 PP-4.7 7.5 .sup.1) 25 22.5 .sup.2) 75 0.33 6.65 .Math. E0 PP-4.8 3.8 .sup.1) 12.7 26.2 .sup.2) 87.3 0.15 1.88 .Math. E+01 PP-4.9 0 30 .sup.2) 100 5.85 .Math. E+02 PP-4.10 15 .sup.1) 50 15.sup.3) 50 1 1.37 .Math. E0 PP-4.11 15 .sup.1) 50 15.sup.4) 50 1 2.13 .Math. E0 PP-4.12.sup. 7.5.sup.5) 0.33 15 .sup.2) 0.67.sup. 2 3.13 .Math. E0 PP-4.13 15 .sup.1) 50 15 (CF) .sup.6) 50 1 0.41 .Math. E0 PP-4.14 10.sup.1) 0.33 10.sup.2) 0.33 1 1.99 .Math. E0 10 (CF) .sup.6) 0.33 CB/ SG.sup.7)/ CB.sup.1): Resistivity.sup./ Sample wt.-% %* wt.-% %* SG.sup.7)# Ohm .Math. cm PP-4.15 15 .sup.1) 50 15 50 1 2.80 .Math. E0 PP-4.16 7.5 .sup.1) 25 22.5.sup. 75 0.33 1.03 .Math. E+02 PP-4.17 0 0 30 100 0 2.85 .Math. E+07 *% of total filler content; .sup.# wt.-% ratio of carbon black (CB) to: i) expanded graphite (EG) or ii) EG + carbon fiber (CF) or iii) CF alone; ; .sup.Resistivity expressed as average of parallel and perpendicular mode measurements; .sup.Total amount of filler for sample PP-4.12 = 22.5 wt.-%; .sup.1) Carbon black = Ensaco 250G from Imerys with OAN = 190 mL/g and BET specific surface area under nitrogen of 65 m.sup.2/g; .sup.2) Expanded graphite = Timrex C-THERM 011 from Imerys with D.sub.90 = 90 m; .sup.3)Expanded graphite = Timrex C-THERM 301 from Imerys with D.sub.90 = 30 m; .sup.4)Expanded graphite = Timrex C-THERM MAX HD from Imerys with D.sub.90 > 400 m; .sup.5)Carbon black = extra-conductive carbon black Ensaco 350G from Imerys with OAN of 320 mL/100 g and BET specific surface area under nitrogen of 770 m.sup.2/g; total loading of conductive additives only 22.5 wt.-% based on the total weight of the composition; .sup.6) Carbon fiber = Tenax A HT P802 3 mm from Teijin with fiber diameter of 7 m and pellet length of 8 mm. .sup.7)Synthetic graphite = Synthetic graphite = Timrex SFG44 Primary Synthetic Graphite from Imerys with BET specific surface area of ca. 5 m.sup.2/g and D.sub.90 = 50 m.
[0101] From Table 4.1 and
[0102] In particular, it can be derived from Table 4.1 and
4.2. Volume Resistivity Data for Polyamide Compositions
TABLE-US-00008 TABLE 4.2 Volume resistivity data for polyamide compositions with conductive fillers of single-component additives and binary blends of carbon black and expanded graphite, also see FIG. 4. Total amount Filler filler/ Resistivity/ St. dev./ Sample type wt.-% Ohm .Math. cm Ohm .Math. cm Ctrl. 0 8.07.Math.E+14 3.73.Math.E+14 PA-4.1 CB.sup.1) 5 5.78 .Math.+ 14 3.22.Math.E+13 PA-4.2 10 2.43.Math.E+14 3.46.Math.E+13 PA-4.3 15 1.96.Math.E+11 1.46.Math.E+11 PA-4.4 20 1.37.Math.E+06 2.51.Math.E+06 PA-4.5 EG.sup.2) 5 5.30.Math.E+14 3.90.Math.E+14 PA-4.6 10 2.60.Math.E+13 2.84.Math.E+13 PA-4.7 15 3.02.Math.E+06 2.85.Math.E+06 PA-4.8 20 2.77.Math.E+06 1.17.Math.E+06 PA-4.9 30 7.69.Math.E+06 1.44.Math.E+07 PA-4.10 SG.sup.3) 10 5.47.Math.E+14 2.06.Math.E+14 PA-4.11 20 8.45.Math.E+13 1.98.Math.E+13 PA-4.12 30 1.92.Math.E+08 1.20.Math.E+08 PA-4.13 Blend of 25 2.93.Math.E+02 4.62.Math.E+02 CB.sup.1) + EG.sup.2) (12.5 CB + 12.5 EG) .sup.1)Carbon black = Ensaco 250G from Imerys with OAN = 190 mL/g and BET specific surface area under nitrogen of 65 m.sup.2/g; .sup.2)Expanded graphite = Timrex C-THERM 011 from Imerys with D.sub.90 = 90 m; .sup.3)Synthetic graphite = Timrex KS44 from Imerys with a BET specific surface area under nitrogen of ca. 9 m.sup.2/g and D.sub.90 = 46 m.
[0103] As can be derived from Table 4.2 and
Example 5: Measurement of the EMI Shielding Efficiency of Polypropylene Compositions
[0104] The inventors of the present invention found that blends of carbon black and expanded graphite according to the present invention advantageously provide for superior EMI shielding:
EMI shielding data were obtained for polypropylene compositions at a frequency of 10 MHz to 1000 MHz. Selected data points for corrected EMI shielding efficiency (attenuation) in dB are reproduced in Table 5 below.
TABLE-US-00009 TABLE 5 EMI shielding data for polypropylene compositions with blends of carbon black and expanded graphite (samples PP-5.1 to PP-5.5) and compositions with blends of different kinds of carbon black and different kinds of expanded graphite (samples PP-5.6 to PP-5.8), optionally with additional carbon fibers as conductive additives (samples PP-5.9 to PP-5.10), also see FIG. 5A and FIG. 5B. EMI shielding CB/ EG/ wt.-% Frequ./ EMI SE/ Sample wt.-% %* wt.-% %* ratio.sup.# MHz dB () Ctrl. 0 0 10 1 (0.05) 50 1 (0.04) 104 1 (0.03) 203 1 (0.03) 401 1 (0.04) 604 1 (0.03) 802 1 (0.03) 1000 1 (0.02) PP-5.1 30.sup.1) 100 0 10 12 (5.42) 50 32 (0.35) 104 32 (0.08) 203 31 (0.08) 401 33 (0.05) 604 31 (0.08) 802 30 (0.12) 1000 31 (0.15) PP-5.2 22.5.sup.1) 75 7.5.sup.2) 25 3 10 18 (7.59) 50 38 (0.71) 104 39 (0.34) 203 38 (0.35) 401 40 (0.14) 604 39 (0.24) 802 38 (0.20) 1000 40 (0.17) PP-5.3 15.sup.1) 50 15.sup.2) 50 1 10 12 (1.71) 50 41 (0.30) 104 41 (0.50) 203 40 (0.26) 401 43 (0.36) 604 42 (0.42) 802 42 (0.42) 1000 44 (0.43) PP-5.4 7.5.sup.1) 25 22.5.sup.2) 75 0.33 10 15 (5.91) 50 37 (1.42) 104 39 (1.11) 203 36 (0.54) 401 39 (0.69) 604 38 (0.70) 802 38 (0.82) 1000 39 (0.92) PP-5.5 0 30.sup.2) 100 10 16 (3.20) 50 27 (0.52) 104 27 (0.55) 203 26 (0.47) 401 28 (0.48) 604 26 (0.46) 802 25 (0.46) 1000 25 (0.45) PP-5.6 15.sup.1) 50 15.sup.3) 50 1 10 16 (2.33) 50 36 (1.00) 104 36 (0.38) 203 34 (0.44) 401 36 (0.54) 604 35 (0.52) 802 34 (0.55) 1000 35 (0.60) PP-5.7 15.sup.1) 50 15.sup.4) 50 1 10 15 (4.77) 50 32 (0.58) 104 33 (0.47) 203 31 (0.14) 401 33 (0.23) 604 31 (0.21) 802 30 (0.19) 1000 31 (0.17) PP-5.8 7.5.sup.5) 33 15.sup.2) 67 1 10 16 (1.44) 50 32 (0.24) 104 32 (0.08) 203 31 (0.09) 401 33 (0.19) 604 31 (0. 16) 802 30 (0.15) 1000 31 (0.15) PP-5.9 15.sup.1) 50 15.sup.6) 50 10 12 (4.60) 50 36 (0.88) 104 37 (0.47) 203 35 (0.48) 401 37 (0.79) 604 36 (0.76) 802 35 (0.86) 1000 36 (0.95) PP-5.10.sup.7) 10.sup.1) 33 10.sup.2) 33 1 10 14 (6.81) 50 38 (0.77) 104 38 (0.61) 203 36 (0.50) 401 39 (0.79) 10.sup.6) 33 604 38 (0.65) 802 37 (0.70) 1000 38 (0.76) *% of total filler content; .sup.#wt.-% ratio of carbon black (CB) to: i) expanded graphite (EG) or ii) EG + carbon fiber (CF) or iii) CF alone; .sup.1)Carbon black = Ensaco 250G from Imerys with OAN = 190 mL/g and BET specific surface area under nitrogen of 65 m.sup.2/g; .sup.2)Expanded graphite = Timrex C-THERM 011 from Imerys with D.sub.90 = 90 m; .sup.3)Expanded graphite = Timrex C-THERM 301 from Imerys with D.sub.90 = 30 m; .sup.4)Expanded graphite = Timrex C-THERM MAX HD from Imerys with D.sub.90 > 400 m; .sup.5)Carbon black = extra-conductive carbon black Ensaco 350G from Imerys with OAN of 320 mL/100 g and BET specific surface area under nitrogen of 770 m.sup.2/g; total loading of conductive additives only 22.5 wt.-% based on the total weight of the composition; .sup.6)Carbon fiber Tenax A HT P802 3 mm from Teijin with fiber diameter of 7 m and pellet length of 8 mm. .sup.7)Conductive additives = 10 wt.-% CB (Ensaco 250G), 10 wt.-% EG (Timrex C-THERM 011), 10 wt.-% carbon fiber (Tenax A HT P802) .
[0105] As can be derived from Table 5 and
[0106] Also, the sample PP-5.3 comprising 15 wt.-% carbon black (Ensaco 250 G)/15 wt.-% expanded graphite (Timrex C-THERM 011) shows an attenuation of about 40 to 45 dB in the frequency region of about 20 to about 1000 MHz. The present inventors surprisingly found that this composition is even superior to compositions with carbon fibers, emphasizing the extraordinary EMI shielding performance of compositions according to the present invention.
Example 6: Measurement of the Thermal Conductivity
[0107] The inventors of the present invention found that blends of carbon black and expanded graphite according to the present invention advantageously provide for good thermal conductivity:
6.1 Thermal Conductivity Data for Polypropylene Compositions
TABLE-US-00010 TABLE 6.1 Thermal conductivity data for polypropylene compositions with blends of carbon black and expanded graphite (samples PP-6.1 to PP-6.5) and compositions with blends of different kinds of carbon black and different kinds of expanded graphite (samples PP-6.6 to PP-6.8), optionally with additional carbon fibers as conductive additives (samples PP-6.9 to PP-6.10), also see FIG. 6A. Thermal conductivity/ W .Math. m.sup.1K.sup.1 CE/ EG/ Wt.-% Through In Sample wt.-% %* wt.-% %* ratio.sup.# plane plane Ctrl. 0 0 0.23 0.31 PP-6.1 30.sup.1) 100 0 0.47 0.97 PP-6.2 22.5.sup.1) 75 7.5.sup.2) 25 3 0.70 1.86 PP-6.3 15.sup.1) 50 15.sup.2) 50 1 0.76 3.08 PP-6.4 7.5.sup.1) 25 22.5.sup.2) 75 0.33 0.87 6.40 PP-6.5 0 30.sup.2) 100 0.90 7.75 PP-6.6 15.sup.1) 50 .sup.15 .sup.3) 50 1 0.63 2.51 PP-6.7 15.sup.1) 50 .sup.15 .sup.4) 50 1 0.68 1.91 PP-6.8 7.5.sup.5) 33 15.sup.2) 67 1 0.67 2.62 PP-6.9 15.sup.1) 50 .sup.15 .sup.6) 50 0.34 0.72 PP-6.10.sup.7) 10.sup.1) 33 .sup.10 .sup.2) 33 1 0.55 1.97 .sup.10 .sup.6) 33 *% of total filler content; .sup.#wt.-% ratio of carbon black (CB) to: i) expanded graphite (EG) or ii) EG + carbon fiber (CF) or iii) CF alone; .sup.1)Carbon black = Ensaco 250G from Imerys with OAN = 190 mL/g and BET specific surface area under nitrogen of 65 m.sup.2/g; .sup.2)Expanded graphite = Timrex C-THERM 011 from Imerys with D.sub.90 = 90 m; .sup.3) Expanded graphite = Timrex C-THERM 301 from Imerys with D.sub.90 = 30 m; .sup.4) Expanded graphite = Timrex C-THERM MAX HD from Imerys with D.sub.90 > 400 m; .sup.5)Carbon black = extra-conductive carbon black Ensaco 350G from Imerys with OAN of 320 mL/100 g and BET specific surface area under nitrogen of 770 m.sup.2/g; total loading of conductive additives only 22.5 wt.-% based on the total weight of the composition; .sup.6) No expanded graphite but carbon fiber = Tenax A HT P802 3 mm from Teijin with fiber diameter of 7 m and pellet length of 8 mm. .sup.7)Conductive additives = 10 wt.-% CB (Ensaco 250G), 10 wt.-% EG (Timrex C-THERM 011), 10 wt.-% carbon fiber (Tenax A HT P802).
[0108] As can be derived from Table 6.1 and
[0109] At equal additive loadings of 30 wt.-% and ratios of carbon black to expanded graphite of 1 (i.e. samples PP-6.3, PP-6.6 and PP-6.7), sample PP-6.3 with Timrex C-THERM 011 from Imerys with D.sub.90=90 m as expanded graphite component provides for the highest thermal conductivity.
[0110] Also, use of carbon fibers results in inferior thermal conductivity compared with samples according to the present invention not comprising carbon fibers.
6.2. Thermal Conductivity Data for Polyamide Compositions
TABLE-US-00011 TABLE 6.2 Thermal conductivity data for polyamide compositions with conductive fillers of single-component additives and binary blends of carbon black and expanded graphite, also see FIG. 6B. Total Thermal conductivity/ amount W .Math. m.sup.1K.sup.1 Filler filler/ Through In Sample type wt.-% plane plane Ctrl. 0 0.29 0.34 PA-6.1 CB.sup.1) 5 0.32 0.37 PA-6.2 10 0.37 0.42 PA-6.3 15 0.40 0.47 PA-6.4 20 0.44 0.46 PA-6.5 EG.sup.2) 5 0.48 0.72 PA-6.6 10 0.76 1.39 PA-6.7 15 1.06 2.69 PA-6.8 20 1.14 5.42 PA-6.9 30 2.23 10.10 PA-6.10 SG.sup.3) 10 0.41 0.75 PA-6.11 20 0.60 1.55 PA-6.12 30 0.75 2.95 PA-6.13 Blend of 25 0.90 2.83 CB.sup.1) + EG.sup.2) (12.5 CB + 12.5 EG) .sup.1)Carbon black = Ensaco 250G from Imerys with OAN = 190 mL/g and BET specific surface area under nitrogen of 65 m.sup.2/g; .sup.2)Expanded graphite = Timrex C-THERM 011 from Imerys with D.sub.90 = 90 m; .sup.3)Synthetic graphite = Timrex KS44 from Imerys with a BET specific surface area under nitrogen of ca. 9 m.sup.2/g and D.sub.90 = 46 m.
[0111] As can be derived from Table 6.2 and
[0112] Also, sample PA-6.13 with a blend of 12.5 wt.-% carbon black (Ensaco 250G) and 12.5 wt.-% expanded graphite (Timrex C-THERM 011) provides for similar in-plane thermal conductivity as sample PA-6.12 with 30 wt.-% synthetic graphite.
Example 7: Measurement of Mechanical Properties: Tensile Strength
[0113] The inventors of the present invention found that blends of carbon black and expanded graphite according to the present invention advantageously provide for good tensile strength:
7.1. Tensile Strength Data for Polypropylene Compositions
TABLE-US-00012 TABLE 7.1 Tensile strength data for polypropylene compositions with blends of carbon black and expanded graphite (samples PP-7.1 to PP-7.9) or with synthetic graphite instead of expanded graphite (samples PP-7.10 to PP-7.12), also see FIG. 7A. Elasticity CB.sup.1)/ EG.sup.2)/ CB.sup.1): modulus/ Sample wt.-% %* wt.-% %* EG.sup.2)# MPa PP-7.1 30 100 0 1362 (51) PP-7.2 26.2 87.3 3.8 12.7 6.9 1562 (34) PP-7.3 22.5 75 7.5 25 3 1734 (42) PP-7.4 18.7 62 11.3 38 1.65 1907 (41) PP-7.5 15 50 15 50 1 2130 (16) PP-7.6 11.3 38 18.7 62 0.6 2269 (22) PP-7.7 7.5 25 22.5 75 0.33 2373 (21) PP-7.8 3.8 12.7 26.2 87.3 0.15 2477 (33) PP-7.9 0 30 100 2500 (58) Elasticity CB.sup.1)/ SG.sup.3)/ CB.sup.1): modulus/ Sample wt.-% %* wt.-% %* SG.sup.3)# MPa PP-7.10 15 50 15 50 1 1774 (51) PP-7.11 7.5 25 22.5 75 0.33 1820 (25) PP-7.12 0 30 100 1846 (65) *% of total filler content; .sup.#wt.-% ratio of carbon black (CB) and expanded graphite (EG) or synthetic graphite (SG); .sup.1)Carbon black = Ensaco 250G from Imerys with OAN = 190 mL/g and BET specific surface area under nitrogen of 65 m.sup.2/g; .sup.2)Expanded graphite = Timrex C-THERM 011 from Imerys with D.sub.90 = 90 m; .sup.3)Synthetic graphite = Synthetic graphite = Timrex SFG44 Primary Synthetic Graphite from Imerys with BET specific surface area of ca. 5 m.sup.2/g and D.sub.90 = 50 m.
[0114] The inventors of the present invention surprisingly found that compositions according to the invention of carbon black and expanded graphite provide for superior tensile properties when compared to blends of carbon black and synthetic graphite: As can be derived from Table 7.1 and
7.2. Tensile Strength Data for Polyamide Compositions
TABLE-US-00013 TABLE 7.2 Tensile strength data for polyamide compositions with conductive fillers of single-component additives and binary blends of carbon black and expanded graphite, also see FIG. 7B. Total amount Elasticity filler/ modulus/ St. dev./ Sample Filler type wt.-% MPa MPa Ctrl. 0 1233.54 313.10 PA-7.1 CB.sup.1) 5 1451.97 209.70 PA-7.2 10 1467.48 202.20 PA-7.3 15 1699.73 196.20 PA-7.4 20 1768.78 75.80 PA-7.5 EG.sup.2) 5 1594.32 91.20 PA-7.6 10 2150.04 74.00 PA-7.7 15 2268.10 93.80 PA-7.8 20 3670.68 144.50 PA-7.9 30 4545.61 182.80 PA-7.10 SG .sup.3) 10 1887.52 117.90 PA-7.11 20 2709.60 143.70 PA-7.12 30 3718.11 109.40 PA-7.13 Blend of 25 3044.65 107.20 CB.sup.1) + EG.sup.2) (12.5 CB + 2892.05 112.00 12.5 EG) .sup.1)Carbon black = Ensaco 250G from Imerys with OAN = 190 mL/g and BET specific surface area under nitrogen of 65 m.sup.2/g; .sup.2)Expanded graphite = Timrex C-THERM 011 from Imerys with D.sub.90 = 90 m; .sup.3) Synthetic graphite = Timrex KS44 from Imerys with a BET specific surface area under nitrogen of ca. 9 m.sup.2/g and D.sub.90 = 46 m.
CITED DOCUMENTS
[0115] WO 2012/020099 A1 [0116] U.S. Pat. No. 1,137,373 [0117] U.S. Pat. No. 1,191,383 [0118] U.S. Pat. No. 4,946,982 [0119] U.S. Pat. No. 5,582,781 [0120] U.S. Pat. No. 4,530,949 [0121] U.S. Pat. No. 4,704,231 [0122] US 2006/0148965 A1 [0123] US 2018/0022398 A [0124] U.S. Pat. No. 11,024,849 B2 [0125] Leo et al., Journal of Polymers and the Environment, 2020, 28, pp. 2021-2100, https://doi.org/10.1007/s10924-020-01753-4
LIST OF EMBODIMENTS
[0126] A 1st embodiment of the present invention relates to a composition comprising [0127] (a) carbon black in an amount of 3 to 40, or 5 to 35, or 10 to 30, or 12 to 26, or 13 to 18 wt.-% based on the total weight of the composition; [0128] and [0129] (b) expanded graphite in an amount of 3 to 50, or 3 to 40, or 3 to 35, or 3 to 30, or 3.5 to 20, or 4 to 18, or 5 to 17, or 7 to 15 wt.-% based on the total weight of the composition.
[0130] A 2nd embodiment of the present invention relates to a composition according to the 1st embodiment, wherein the combined amounts of carbon black and expanded graphite are 10 to 50, or 17 to 45, or 19 to 40, or 20 to 35, or 22 to 34, or 24 to 31, or 25 to 30 wt.-% based on the total weight of the composition.
[0131] A 3.sup.rd embodiment of the present invention relates to a composition according to any one of the preceding embodiments, wherein the ratio of wt.-% based on the total weight of the composition of carbon black to expanded graphite is in the range of 0.1 to 9, or 0.33 to 9, or 0.4 to 9, or 0.4 to 7, or 0.4 to 5, or 0.4 to 3, or 0.4 to 2, or 0.6 to 1.7.
[0132] A 4.sup.th embodiment of the present invention relates to a composition according to any one of the preceding embodiments, wherein the carbon black is characterized by [0133] a BET specific surface area measured according to ASTM D-3037 under nitrogen of less than 950 m.sup.2.Math.g.sup.1, or less than 850 m.sup.2.Math.g.sup.1, or less than 700 m.sup.2.Math.g.sup.1, or less than 600 m.sup.2.Math.g.sup.1, or less than 500 m.sup.2.Math.g.sup.1, in particular in the range of 40 to 800, or 50 to 800, or 30 to 100, or 50 to 80, or 60 to 70 m.sup.2.Math.g.sup.1 [0134] and, optionally, one or more of the following: [0135] a primary particle size measured according to ASTM D-3849-14a of 10 to 60, preferably 15 to 55, more preferably 20 to 40, even more preferably 25 to 35 nm; and/or [0136] an oil absorption number OAN when measured according to ASTM D-2414-01 of less than 400 ml.Math.g.sup.1, or less than 390 ml.Math.g.sup.1, or less than 380 ml.Math.g.sup.1, or less than 370 ml.Math.g.sup.1, or less than 350 ml.Math.g.sup.1, in particular in the range of 100 to 330, or 150 to 230, or 170 to 210, or 180 to 200, or 185 to 195 ml.Math.g.sup.1.
[0137] A 5th embodiment of the present invention relates to a composition according to any one of the preceding embodiments, wherein the expanded graphite is characterized by one or more of the following: [0138] a particle size distribution D.sub.90 when measured according to ISO 13220 of 5 to 1000, or 20 to 800, or 30 to 700, or 50 to 600, or 70 to 500, or 80 to 250, or 85 to 150 m; [0139] and/or [0140] a bulk density when measured according to ASTM D-7481 of 0.01 to 1.00, or 0.02 to 0.9, or 0.05 to 0.7, even or 0.1 to 0.55, or 0.13 to 0.50, or 0.16 to 0.45, or 0.16 to 0.25 g.Math.cm.sup.3.
[0141] A 6th embodiment of the present invention relates to a composition comprising [0142] (a) carbon black; and [0143] (b) expanded graphite; [0144] wherein the carbon black is characterized [0145] by a BET specific surface area measured according to ASTM D-3037 under nitrogen of less than 950 m.sup.2.Math.g.sup.1, or less than 850 m.sup.2.Math.g.sup.1, or less than 700 m.sup.2.Math.g.sup.1, or less than 600 m.sup.2.Math.g.sup.1, or less than 500 m.sup.2.Math.g.sup.1, in particular in the range of 40 to 800, or 50 to 800, or 30 to 100, or 50 to 80, or 60 to 70 m.sup.2.Math.g.sup.1; [0146] and, optionally, one or more of the following: [0147] a primary particle size measured according to ASTM D-3849-14a of 10 to 60, or 15 to 55, or 20 to 40, or 25 to 35 nm; and/or [0148] an oil absorption number OAN when measured according to ASTM D-2414 of less than 400 ml.Math.g.sup.1, or less than 390 ml.Math.g.sup.1, or less than 380 ml.Math.g.sup.1, or less than 370 ml.Math.g.sup.1, or less than 350 ml.Math.g.sup.1, in particular in the range of 100 to 330, or 150 to 230, or 170 to 210, or 180 to 200, or 185 to 195 ml.Math.g.sup.1; [0149] and/or [0150] wherein the expanded graphite is characterized by one or more of the following: [0151] a particle size distribution D.sub.90 when measured according to ISO 13220 of 5 to 1000, or 20 to 800, or 30 to 700, or 50 to 600, or 70 to 500, or 80 to 250, or 85 to 150 m; [0152] and/or [0153] or a bulk density when measured according to ASTM D-7481 of 0.01 to 1.00, or 0.02 to 0.9, or 0.05 to 0.7, or 0.1 to 0.55, or 0.13 to 0.50, or 0.16 to 0.45, or 0.16 to 0.25 g.Math.cm.sup.3.
[0154] A 7th embodiment of the present invention relates to a composition according to the 6th embodiment, wherein the composition comprises the carbon black in an amount of 3 to 40, or 5 to 35, or 10 to 30, or 12 to 26, or 13 to 18 wt.-% based on the total weight of the composition.
[0155] An 8th embodiment of the present invention relates to a composition according to any one of the 6th or 7th embodiments, wherein the composition comprises expanded graphite in an amount of 3 to 50, or 3 to 40, or 3 to 35, or 3 to 30, or 3.5 to 20, or 4 to 18, or 5 to 17, or 7 to 15 wt.-% based on the total weight of the composition.
[0156] A 9th embodiment of the present invention relates to a composition according to any one of the 6th to the 8th embodiment, wherein the composition comprises carbon black and expanded graphite in a combined amount of 10 to 50, or 17 to 45, or 19 to 40, or 20 to 35, or 22 to 34, or 24 to 31, or 25 to 30 wt.-% based on the total weight of the composition.
[0157] A 10th embodiment of the present invention relates to a composition according to any one of the 6th to the 9th embodiment, wherein the ratio of wt.-% based on the total weight of the composition of carbon black to graphite is in the range of 0.1 to 9, or 0.33 to 9, or 0.4 to 9, or 0.4 to 7, or 0.4 to 5, or 0.4 to 3, or 0.4 to 2, or 0.6 to 1.7.
[0158] An 11th embodiment of the present invention relates to a composition comprising carbon black and expanded graphite, wherein the ratio of wt.-% based on the total weight of the composition of carbon black to graphite is in the range of 0.1 to 9, or 0.33 to 9, or 0.4 to 9, or 0.4 to 7, or 0.4 to 5, or 0.4 to 3, or 0.4 to 2, or 0.6 to 1.7 and [0159] wherein the carbon black is characterized by a BET specific surface area measured according to ASTM D-3037 under nitrogen of less than 950 m.sup.2.Math.g.sup.1, or less than 850 m.sup.2.Math.g.sup.1, or less than 700 m.sup.2.Math.g.sup.1, or less than 600 m.sup.2.Math.g.sup.1, or less than 500 m.sup.2.Math.g.sup.1, in particular in the range of 40 to 800, or 50 to 800, or 30 to 100, or 50 to 80, or 60 to 70 m.sup.2.Math.g.sup.1; [0160] and, optionally, one or more of the following: [0161] a primary particle size measured according to ASTM D-3849-14a of 10 to 60, or 15 to 55, or 20 to 40, or 25 to 35 nm; and/or [0162] an oil absorption number OAN when measured according to ASTM D-2414 of less than 400 ml.Math.g.sup.1, or less than 390 ml.Math.g.sup.1, or less than 380 ml.Math.g.sup.1, or less than 370 ml.Math.g.sup.1, or less than 350 ml.Math.g.sup.1, in particular in the range of 100 to 330, or 150 to 230, or 170 to 210, or 180 to 200, or 185 to 195 ml.Math.g.sup.1; [0163] and/or [0164] wherein the expanded graphite is characterized by one or more of the following: [0165] a particle size distribution D.sub.90 when measured according to ISO 13220 of 5 to 1000, or 20 to 800, or 30 to 700, or 50 to 600, or 70 to 500, or 80 to 250, or 85 to 150 m; [0166] and/or [0167] or a bulk density when measured according to ASTM D-3037 of 0.01 to 1.00, or 0.02 to 0.9, or 0.05 to 0.7, or 0.1 to 0.55, or 0.13 to 0.50, or 0.16 to 0.45, or 0.16 to 0.25 g.Math.cm.sup.3.
[0168] A 12th embodiment of the present invention relates to a composition according to the 11th embodiment, wherein the composition comprises the carbon black in an amount of 3 to 40, or 5 to 35, or 10 to 30, or 12 to 26, or 13 to 18 wt.-% based on the total weight of the composition.
[0169] A 13th embodiment of the present invention relates to a composition according to any one the 11th or 12th embodiments, wherein the composition comprises the expanded graphite in an amount of 3 to 50, or 3 to 40, or 3 to 35, or 3 to 30, or 3.5 to 20, or 4 to 18, or 5 to 17, or 7 to 15 wt.-% based on the total weight of the composition.
[0170] A 14th embodiment of the invention relates to a composition according to any one of the 11th to the 13th embodiment, wherein the composition comprises carbon black and expanded graphite in a combined amount of 10 to 50, or 17 to 45, or 19 to 40, or 20 to 35, or 22 to 34, or 25 to 30 wt.-% based on the total weight of the composition.
[0171] A 15th embodiment of the present invention relates to a composition according to any one of the preceding embodiments comprising one or more further fillers selected from the group consisting of metal powder, metal flakes, glass fibers, silicon fibers, carbon-based fillers selected from the group consisting of carbon conductive additives, natural graphite, synthetic graphite, surface modified graphite, graphite nanoplatelets, multiwall carbon nanotubes, single wall carbon nanotube, carbon nanostructures, metal-coated graphite, and combinations thereof.
[0172] A 16th embodiment of the present invention relates to a composition according to any one of the preceding embodiments comprising a polymer, preferably, the polymer being selected from the from the group consisting of polyolefins, preferably the polyolefins being selected from polyethylene, propylene and combinations thereof, more preferably the polyolefins are polypropylene, polyamides, polymethylmethacrylate (PMMA), polyacetal, polycarbonate, polyvinyls, polyacrylonitrile, polybutadiene, polystyrene, polyacrylate, epoxy polymers, polyesters, polycarbonates, polyketones, polysulfones, unsaturated polyesters, polyurethanes, polycyclopentadienes, silicones, rubber, thermosets, thermoplastics, binders for coating and combinations thereof.
[0173] A 17th embodiment of the present invention relates to a shaped article of composite material comprising the composition according to any one of the 1st to the 16th embodiment.
[0174] An 18th embodiment of the present invention relates to a substrate coated with a coating comprising the composition according to any one of the 1st to the 16th embodiment.
[0175] A 19th embodiment of the present invention relates to the shaped article according to the 17th embodiment or the coated substrate according to the 18th embodiment comprising a polymer selected from the group consisting of polyolefins, preferably the polyolefins being selected from polyethylene, polypropylene and combinations thereof, more preferably the polyolefins are polypropylene, polyamides, polymethylmethacrylate (PMMA), polyacetal, polycarbonate, polyvinyls, polyacrylonitrile, polybutadiene, polystyrene, polyacrylate, epoxy polymers, polyesters, polycarbonates, polyketones, polysulfones, unsaturated polyesters, polyurethanes, polycyclopentadienes, silicones, rubber, thermosets, thermoplastics, binders for coating and combinations thereof.
[0176] A 20th embodiment of the present invention relates to the shaped article or the coated substrate according to the 19th embodiment, wherein the carbon black and the expanded graphite are dispersed in the polymer.
[0177] A 21st embodiment of the present invention relates to the use of the composition according to any one of the 1st to the 16th embodiment or the shaped article according to the 17th or 19th to 20th embodiments or the coated substrate according to any one of the 18th to the 20th embodiments for providing one or more of the following: [0178] electro-magnetic interference (EMI) shielding measured according to ASTM D-4935 at a frequency of 10 to 1000 MHz or method derived therefrom as detailed in the paper E. Hariya and U. Massahiro, Instruments for Measuring Shielding Effectiveness, EMC 1984 Tokyo, wherein the EMI shielding is at least 20 dB, or at least 30 dB, or at least 40 dB; [0179] volume resistivity measured according to ASTM D-4496, wherein the volume resistivity is less than 1000 Ohm.Math.cm, or less than 100 Ohm.Math.cm, or less than 10 Ohm.Math.cm, or less than 1 Ohm.Math.cm; and/or [0180] in-plane thermal conductivity measured according to ASTM E 1461 wherein the in-plane thermal conductivity is greater than 0.5 Wm.sup.1K.sup.1, or greater than 0.7 Wm.sup.1K.sup.1, or greater than 0.9 Wm.sup.1K.sup.1, or greater than 1.1 Wm.sup.1K.sup.1, or greater than 1.3 Wm.sup.1K.sup.1, or greater than 1.5 Wm.sup.1K.sup.1, or greater than 1.7 Wm.sup.1K.sup.1, or greater than 2.0 Wm.sup.1K.sup.1, or greater than 2.5 Wm.sup.1K.sup.1, or greater than 3.0 Wm.sup.1K.sup.1, or greater than 4.0 Wm.sup.1K.sup.1, or greater than 5.0 Wm.sup.1K.sup.1, or greater than 6.0 Wm.sup.1K.sup.1, or greater than 7.0 Wm.sup.1K.sup.1.
[0181] A 22nd embodiment of the present invention relates to a method of providing electromagnetic interference (EMI) shielding measured according to ASTM D-4935 at a frequency of 10 MHz to 1000 MHz or method derived therefrom as detailed in the paper E. Hariya and U. Massahiro, Instruments for Measuring Shielding Effectiveness, EMC 1984 Tokyo in a polymeric composition using the composition according to any one of the 1st to the 16th embodiment or the shaped article according to the 17th or 19th to 20th embodiments or the coated substrate according to any one of the 18th to the 20th embodiments, wherein the EMI shielding is at least 20 dB, or at least 30 dB, or at least 40 dB.
[0182] A 23rd embodiment of the present invention relates to a method of providing volume resistivity when measured according to standard test method ASTM D-4496 in a polymeric composition using the composition according to any one of the 1st to the 16th embodiment or the shaped article according to the 17th or 19th to 20th embodiments or the coated substrate according to any one of the 18th to the 20th embodiments wherein the volume resistivity is less than 1000 Ohm.Math.cm, or less than 100 Ohm.Math.cm, or less than 10 Ohm.Math.cm, or less than 1 Ohm.Math.cm.
[0183] A 24th embodiment of the present invention relates to a method of providing in-plane thermal conductivity measured according to ASTM E 1461 in a polymeric composition using the composition according to any one of the 1st to the 16th embodiments or the shaped article according to the 17th or 19th to 20th embodiments or the coated substrate according to any one of the 18th to the 20th embodiments, wherein the in-plane thermal conductivity is greater than 0.5 Wm.sup.1K.sup.1, or greater than 0.7 Wm.sup.1K.sup.1, or greater than 0.9 Wm.sup.1K.sup.1, or greater than 1.1 Wm.sup.1K.sup.1, or greater than 1.3 Wm.sup.1K.sup.1, or greater than 1.5 Wm.sup.1K.sup.1, or greater than 1.7 Wm.sup.1K.sup.1, or greater than 2.0 Wm.sup.1K.sup.1, or greater than 2.5 Wm.sup.1K.sup.1, or greater than 3.0 Wm.sup.1K.sup.1, or greater than 4.0 Wm.sup.1K.sup.1, or greater than 5.0 Wm.sup.1K.sup.1, or greater than 6.0 Wm.sup.1K.sup.1, or greater than 7.0 Wm.sup.1K.sup.1.
[0184] A 25th embodiment of the present invention relates to the use or the method of providing electromagnetic interference (EMI) shielding according to of any one of the 21st or 22nd embodiments, wherein the EMI shielding is improved by at least 10 dB, or at least 20 dB, or at least 25 dB, or at least 30 dB, or at least 35 dB, or at least 40 dB, or at least 45 dB, in particular by 10 to 80 dB, or 15 to 70 dB, or 18 to 60 dB, or 20 to 55 dB, or 25 to 50 dB, or 27 to 50 dB, or 30 to 50 dB, or 31 to 45 dB, or 35 to 42 dB when compared to a reference material not comprising carbon black, expanded graphite or any other conductive filler or additive, in particular a composition according to any one of the 1st to the 16th embodiments.
[0185] A 26th embodiment of the present invention relates to the use or the method of providing volume resistivity according to any one of the 21st or 23rd embodiments, wherein the volume resistivity is reduced by a factor of 1.3 to 109, or 1.5 to 108, or 2 to 107, or 2 to 106, or 2 to 105, or 3 to 105, or 3 to 104, or 5 to 104, or 7 to 104, or 7 to 103, or 10 to 103, or 15 to 103, or 50 to 103, or 102 to 103 when compared to a reference material not comprising carbon black, expanded graphite or any other conductive filler or additive, in particular a composition according to any one of the 1st to the 16th embodiments.
[0186] A 27th embodiment of the present invention relates to the use or the method of providing in-plane thermal conductivity according to any one of the 21st or 24th embodiments, wherein the in-plane thermal conductivity is increased by a factor of 2, or 3, or 4, or 5, or 6, or 7, or 8, or 9, or 10, or 12, or 14, or 16, or 18, or 20, or 25, or 30, or 40, or 50 when compared to a reference material not comprising carbon black, expanded graphite or any other conductive filler or additive, in particular a composition according to any one of the 1st to the 16th embodiments.