Thermal paste for improving thermal contacts

Abstract

A thermally conductive paste including porous agglomerates of carbon particles dispersed in a paste-forming vehicle is disclosed. The paste is useful as a thermally conductive interface material between a heat or cold source and an object. The paste is particularly useful as a thermally conductive interface material between a heat source and a heat sink. Apparatus and a method of removing heat from a heat source utilizing thermally conductive pastes of the present invention are also disclosed.

1 . A thermally conductive paste comprising porous agglomerates of carbon particles dispersed in a paste-forming vehicle.  
     
     
         2 . The paste as claimed in  claim 1 , wherein the porous agglomerates of carbon particles comprise a carbon black.  
     
     
         3 . The paste as claimed in  claim 1 , wherein the paste-forming vehicle is a paste-forming vehicle system comprising a solvent selected from the group consisting of silicates, glycol ethers, methoxypolyethylene glycol (“MPEG”), ethylene glycol, propylene glycol, ethylene oxide, propylene oxide, polyethylene glycol (“PEG”), PEG modified with various types of functional groups at the ends of a macromolecular chain, oil, water, alcohols, diethyl sulfate, diisobutyl carbinol, diisobutyl ketone, hexylene glycol, isobutyl acetate, isophorone, isopropyl acetate, methyl isobutyl carbinol, ketone, n-butyl acetate, n-propyl acetate, primary amyl acetate mixed isomers, primary amyl alcohol mixed isomers, n-propyl propionate, n-butyl propionate, n-pentyl propionate, methylene chloride, perchloroethylene, trichloroethylene, xylene, acetone, ethyl acetate, and chemically related substances.  
     
     
         4 . The paste as claimed in  claim 1 , wherein the solvent is an organic solvent.  
     
     
         5 . The paste as claimed in  claim 4 , wherein the solvent is polyethylene glycol.  
     
     
         6 . The paste as claimed in  claim 1 , wherein the paste-forming vehicle is a paste-forming vehicle system comprising a solute selected from the group consisting of cellulosic resin, thermoplastic resin, glycidyl methacrylate, hydroxy(meth)acrylate monomers, epsilon-caprolactone monomer, hydroxypropyl acrylate, hydroxyethyl acrylate, ethylene acrylic acid, divinylbenzene, styrene-butadiene latexes, acrylic latexes, vinyl acrylic latexes, styrene acrylic latexes, vinyl versatate latexes, vinyl chloride, vinylbenzyl chloride, chloromethylstyrene, vinyl acetate copolymers, epoxy resins, epoxy acrylate, aminoethylethanolamine, glycol ethers, propylene glycols, ethylene glycols, polyols, ethylene acrylic acid resins, methylcellulose, ethyl cellulose, hydroxyethyl cellulose, polyvinyl alcohol, starch, and chemically related substances.  
     
     
         7 . The paste as claimed in  claim 5 , wherein the paste-forming vehicle system comprises ethyl cellulose as a solute.  
     
     
         8 . The paste as claimed in  claim 7 , wherein the amount of ethyl cellulose present in the paste is in the range of about 3 to about 5 vol. %.  
     
     
         9 . The paste as claimed in  claim 8 , wherein the amount of ethyl cellulose present in the paste is about 3 vol. %.  
     
     
         10 . The paste as claimed in  claim 7 , wherein the amount of carbon particles dispersed in the paste is less than about 2 vol. %.  
     
     
         11 . The paste as claimed in  claim 10 , wherein the amount of carbon particles dispersed in the paste is less than about 1.50 vol. %.  
     
     
         12 . The paste as claimed in  claim 9 , wherein the amount of carbon particles dispersed in the paste is less than about 1.50 vol. %.  
     
     
         13 . The paste as claimed in  claim 12 , wherein the amount of carbon particles dispersed in the paste is about 1.25 vol. %.  
     
     
         14 . The paste as claimed in  claim 13 , wherein the porous agglomerates of carbon particles comprise a carbon black.  
     
     
         15 . The paste as claimed in  claim 4 , wherein the solvent is di(ethylene glycol) butyl ether.  
     
     
         16 . The paste as claimed in  claim 15 , wherein the paste-forming vehicle system comprises ethyl cellulose as a solute.  
     
     
         17 . The paste as claimed in  claim 16 , wherein the amount of ethyl cellulose present in the paste is about 40 vol. %.  
     
     
         18 . The paste as claimed in  claim 16 , wherein the amount of carbon particles dispersed in the paste is less than about 0.40 vol. %.  
     
     
         19 . The paste as claimed in  claim 17 , wherein the amount of carbon particles dispersed in the paste is less than about 0.40 vol. %.  
     
     
         20 . The paste as claimed in  claim 19 , wherein the amount of carbon particles dispersed in the paste is about 0.20 vol. %.  
     
     
         21 . The paste as claimed in  claim 20 , wherein the porous agglomerates of carbon particles comprise a carbon black.  
     
     
         22 . A thermally conductive interface material comprising the paste as claimed in  claim 1 .  
     
     
         23 . A thermally conductive interface material comprising the paste as claimed in  claim 14 .  
     
     
         24 . A thermally conductive interface material comprising the paste as claimed in  claim 21 .  
     
     
         25 . An apparatus comprising: 
 a heat source;    a heat sink for removing heat from the heat source; and    a layer of a thermally conductive paste disposed between and in contact with the heat source and the heat sink, the paste comprising porous agglomerates of carbon particles dispersed in a paste-forming vehicle.    
     
     
         26 . The apparatus as claimed in  claim 25 , wherein the porous agglomerates of carbon particles comprise a carbon black.  
     
     
         27 . The apparatus as claimed in  claim 25 , wherein the paste-forming vehicle is a paste-forming vehicle system comprising a solvent selected from the group consisting of silicates, glycol ethers, methoxypolyethylene glycol (“MPEG”), ethylene glycol, propylene glycol, ethylene oxide, propylene oxide, polyethylene glycol (“PEG”), PEG modified with various types of functional groups at the ends of a macromolecular chain, oil, water, alcohols, diethyl sulfate, diisobutyl carbinol, diisobutyl ketone, hexylene glycol, isobutyl acetate, isophorone, isopropyl acetate, methyl isobutyl carbinol, ketone, n-butyl acetate, n-propyl acetate, primary amyl acetate mixed isomers, primary amyl alcohol mixed isomers, n-propyl propionate, n-butyl propionate, n-pentyl propionate, methylene chloride, perchloroethylene, trichloroethylene, xylene, acetone, ethyl acetate, and chemically related substances.  
     
     
         28 . The apparatus as claimed in  claim 25 , wherein the solvent is an organic solvent.  
     
     
         29 . The apparatus as claimed in  claim 28 , wherein the solvent is polyethylene glycol.  
     
     
         30 . The apparatus as claimed in  claim 25 , wherein the paste-forming vehicle is a paste-forming vehicle system comprising a solute selected from the group consisting of cellulosic resin, thermoplastic resin, glycidyl methacrylate, hydroxy(meth)acrylate monomers, epsilon-caprolactone monomer, hydroxypropyl acrylate, hydroxyethyl acrylate, ethylene acrylic acid, divinylbenzene, styrene-butadiene latexes, acrylic latexes, vinyl acrylic latexes, styrene acrylic latexes, vinyl versatate latexes, vinyl chloride, vinylbenzyl chloride, chloromethylstyrene, vinyl acetate copolymers, epoxy resins, epoxy acrylate, aminoethylethanolamine, glycol ethers, propylene glycols, ethylene glycols, polyols, ethylene acrylic acid resins, methylcellulose, ethyl cellulose, hydroxyethyl cellulose, polyvinyl alcohol, starch, and chemically related substances.  
     
     
         31 . The apparatus as claimed in  claim 29 , wherein the paste-forming vehicle system comprises ethyl cellulose as a solute.  
     
     
         32 . The apparatus as claimed in  claim 31 , wherein the amount of ethyl cellulose present in the paste is in the range of about 3 to about 5 vol. %.  
     
     
         33 . The apparatus as claimed in  claim 32 , wherein the amount of ethyl cellulose present in the paste is about 3 vol. %.  
     
     
         34 . The apparatus as claimed in  claim 31 , wherein the amount of carbon particles dispersed in the paste is less than about 2 vol. %.  
     
     
         35 . The apparatus as claimed in  claim 34 , wherein the amount of carbon particles dispersed in the paste is less than about 1.50 vol. %.  
     
     
         36 . The apparatus as claimed in  claim 33 , wherein the amount of carbon particles dispersed in the paste is less than about 1.50 vol. %.  
     
     
         37 . The apparatus as claimed in  claim 36 , wherein the amount of carbon particles dispersed in the paste is about 1.25 vol. %.  
     
     
         38 . The apparatus as claimed in  claim 37 , wherein the porous agglomerates of carbon particles comprise a carbon black.  
     
     
         39 . The apparatus as claimed in  claim 28 , wherein the solvent is di(ethylene glycol).  
     
     
         40 . The apparatus as claimed in  claim 39 , wherein the paste-forming vehicle system comprises ethyl cellulose as a solute.  
     
     
         41 . The apparatus as claimed in  claim 40 , wherein the amount of ethyl cellulose present in the paste is about 40 vol. %.  
     
     
         42 . The apparatus as claimed in  claim 40 , wherein the amount of carbon particles dispersed in the paste is less than about 0.40 vol. %.  
     
     
         43 . The apparatus as claimed in  claim 41 , wherein the amount of carbon particles dispersed in the paste is less than about 0.40 vol. %.  
     
     
         44 . The apparatus as claimed in  claim 43 , wherein the amount of carbon particles dispersed in the paste is about 0.20 vol. %.  
     
     
         45 . The apparatus as claimed in  claim 44 , wherein the porous agglomerates of carbon particles comprise a carbon black.  
     
     
         46 . A method of removing heat from a heat source comprising: 
 providing a heat sink proximate the heat source and    disposing a layer of a thermally conductive paste between and in contact with the heat source and the heat sink, the paste comprising porous agglomerates of carbon particles dispersed in a paste-forming vehicle.    
     
     
         47 . The method as claimed in  claim 46 , wherein the porous agglomerates of carbon particles comprise a carbon black.  
     
     
         48 . The method as claimed in  claim 46 , wherein the paste-forming vehicle is a paste-forming vehicle system comprising a solvent selected from the group consisting of silicates, glycol ethers, methoxypolyethylene glycol (“MPEG”), ethylene glycol, propylene glycol, ethylene oxide, propylene oxide, polyethylene glycol (“PEG”), PEG modified with various types of functional groups at the ends of a macromolecular chain, oil, water, alcohols, diethyl sulfate, diisobutyl carbinol, diisobutyl ketone, hexylene glycol, isobutyl acetate, isophorone, isopropyl acetate, methyl isobutyl carbinol, ketone, n-butyl acetate, n-propyl acetate, primary amyl acetate mixed isomers, primary amyl alcohol mixed isomers, n-propyl propionate, n-butyl propionate, n-pentyl propionate, methylene chloride, perchloroethylene, trichloroethylene, xylene, acetone, ethyl acetate, and chemically related substances.  
     
     
         49 . The method as claimed in  claim 46 , wherein the solvent is an organic solvent.  
     
     
         50 . The method as claimed in  claim 49 , wherein the solvent is polyethylene glycol.  
     
     
         51 . The method as claimed in  claim 46 , wherein the paste-forming vehicle is a paste-forming vehicle system comprising a solute selected from the group consisting of cellulosic resin, thermoplastic resin, glycidyl methacrylate, hydroxy(meth)acrylate monomers, epsilon-caprolactone monomer, hydroxypropyl acrylate, hydroxyethyl acrylate, ethylene acrylic acid, divinylbenzene, styrene-butadiene latexes, acrylic latexes, vinyl acrylic latexes, styrene acrylic latexes, vinyl versatate latexes, vinyl chloride, vinylbenzyl chloride, chloromethylstyrene, vinyl acetate copolymers, epoxy resins, epoxy acrylate, aminoethylethanolamine, glycol ethers, propylene glycols, ethylene glycols, polyols, ethylene acrylic acid resins, methylcellulose, ethyl cellulose, hydroxyethyl cellulose, polyvinyl alcohol, starch, and chemically related substances.  
     
     
         52 . The method as claimed in  claim 50 , wherein the paste-forming vehicle system comprises ethyl cellulose as a solute.  
     
     
         53 . The method as claimed in  claim 52 , wherein the amount of ethyl cellulose present in the paste is in the range of about 3 to about 5 vol. %.  
     
     
         54 . The method as claimed in  claim 53 , wherein the amount of ethyl cellulose present in the paste is about 3 vol. %.  
     
     
         55 . The method as claimed in  claim 52 , wherein the amount of carbon particles dispersed in the paste is less than about 2 vol. %.  
     
     
         56 . The method as claimed in  claim 55 , wherein the amount of carbon particles dispersed in the paste is less than about 1.50 vol. %.  
     
     
         57 . The method as claimed in  claim 54 , wherein the amount of carbon particles dispersed in the paste is less than about 1.50 vol. %.  
     
     
         58 . The method as claimed in  claim 57 , wherein the amount of carbon particles dispersed in the paste is about 1.25 vol. %.  
     
     
         59 . The method as claimed in  claim 58 , wherein the porous agglomerates of carbon particles comprise a carbon black.  
     
     
         60 . The method as claimed in  claim 49 , wherein the solvent is di(ethylene glycol) butyl ether.  
     
     
         61 . The method as claimed in  claim 60 , wherein the paste-forming vehicle system comprises ethyl cellulose as a solute.  
     
     
         62 . The method as claimed in  claim 61 , wherein the amount of ethyl cellulose present in the paste is about 40 vol. %.  
     
     
         63 . The method as claimed in  claim 61 , wherein the amount of carbon particles dispersed in the paste is less than about 0.40 vol. %.  
     
     
         64 . The method as claimed in  claim 62 , wherein the amount of carbon particles dispersed in the paste is less than about 0.40 vol. %.  
     
     
         65 . The method as claimed in  claim 64 , wherein the amount of carbon particles dispersed in the paste is about 0.20 vol. %.  
     
     
         66 . The method as claimed in  claim 65 , wherein the porous agglomerates of carbon particles comprise a carbon black.  
     
     
         67 . A method of improving a thermal contact between a first object and a second object proximate the first object, comprising disposing a layer of a thermally conductive paste between and in contact with the first object and the second object, the paste comprising porous agglomerates of carbon particles dispersed in a paste-forming vehicle.  
     
     
         68 . The method as claimed in  claim 67 , wherein the first object is a heat source.  
     
     
         69 . The method as claimed in  claim 67 , wherein the first object is a cold source.  
     
     
         70 . The method as claimed in  claim 67 , wherein the porous agglomerates of carbon particles comprise a carbon black.  
     
     
         71 . The method as claimed in  claim 67 , wherein the paste-forming vehicle is a paste-forming vehicle system comprising a solvent selected from the group consisting of silicates, glycol ethers, methoxypolyethylene glycol (“MPEG”), ethylene glycol, propylene glycol, ethylene oxide, propylene oxide, polyethylene glycol (“PEG”), PEG modified with various types of functional groups at the ends of a macromolecular chain, oil, water, alcohols, diethyl sulfate, diisobutyl carbinol, diisobutyl ketone, hexylene glycol, isobutyl acetate, isophorone, isopropyl acetate, methyl isobutyl carbinol, ketone, n-butyl acetate, n-propyl acetate, primary amyl acetate mixed isomers, primary amyl alcohol mixed isomers, n-propyl propionate, n-butyl propionate, n-pentyl propionate, methylene chloride, perchloroethylene, trichloroethylene, xylene, acetone, ethyl acetate, and chemically related substances.  
     
     
         72 . The method as claimed in  claim 67 , wherein the solvent is an organic solvent.  
     
     
         73 . The method as claimed in  claim 72 , wherein the solvent is polyethylene glycol.  
     
     
         74 . The method as claimed in  claim 67 , wherein the paste-forming vehicle is a paste-forming vehicle system comprising a solute selected from the group consisting of cellulosic resin, thermoplastic resin, glycidyl methacrylate, hydroxy(meth)acrylate monomers, epsilon-caprolactone monomer, hydroxypropyl acrylate, hydroxyethyl acrylate, ethylene acrylic acid, divinylbenzene, styrene-butadiene latexes, acrylic latexes, vinyl acrylic latexes, styrene acrylic latexes, vinyl versatate latexes, vinyl chloride, vinylbenzyl chloride, chloromethylstyrene, vinyl acetate copolymers, epoxy resins, epoxy acrylate, aminoethylethanolamine, glycol ethers, propylene glycols, ethylene glycols, polyols, ethylene acrylic acid resins, methylcellulose, ethyl cellulose, hydroxyethyl cellulose, polyvinyl alcohol, starch, and chemically related substances.  
     
     
         75 . The method as claimed in  claim 73 , wherein the paste-forming vehicle system comprises ethyl cellulose as a solute.  
     
     
         76 . The method as claimed in  claim 75 , wherein the amount of ethyl cellulose present in the paste is in the range of about 3 to about 5 vol. %.  
     
     
         77 . The method as claimed in  claim 76 , wherein the amount of ethyl cellulose present in the paste is about 3 vol. %.  
     
     
         78 . The method as claimed in  claim 75 , wherein the amount of carbon particles dispersed in the paste is less than about 2 vol. %.  
     
     
         79 . The method as claimed in  claim 78 , wherein the amount of carbon particles dispersed in the paste is less than about 1.50 vol. %.  
     
     
         80 . The method as claimed in  claim 77 , wherein the amount of carbon particles dispersed in the paste is less than about 1.50 vol. %.  
     
     
         81 . The method as claimed in  claim 80 , wherein the amount of carbon particles dispersed in the paste is about 1.25 vol. %.  
     
     
         82 . The method as claimed in  claim 81 , wherein the porous agglomerates of carbon particles comprise a carbon black.  
     
     
         83 . The method as claimed in  claim 72 , wherein the solvent is di(ethylene glycol) butyl ether.  
     
     
         84 . The method as claimed in  claim 83 , wherein the paste-forming vehicle system comprises ethyl cellulose as a solute.  
     
     
         85 . The method as claimed in  claim 84 , wherein the amount of ethyl cellulose present in the paste is about 40 vol. %.  
     
     
         86 . The method as claimed in  claim 84 , wherein the amount of carbon particles dispersed in the paste is less than about 0.40 vol. %.  
     
     
         87 . The method as claimed in  claim 85 , wherein the amount of carbon particles dispersed in the paste is less than about 0.40 vol. %.  
     
     
         88 . The method as claimed in  claim 87 , wherein the amount of carbon particles dispersed in the paste is about 0.20 vol. %.  
     
     
         89 . The method as claimed in  claim 88 , wherein the porous agglomerates of carbon particles comprise a carbon black.  
     
     
         90 . An apparatus comprising: 
 a cold source;    an object proximate the cold source; and    a layer of a thermally conductive paste disposed between and in contact with the cold source and the object, the paste comprising porous agglomerates of carbon particles dispersed in a paste-forming vehicle.    
     
     
         91 . The apparatus as claimed in  claim 90 , wherein the porous agglomerates of carbon particles comprise a carbon black.  
     
     
         92 . The apparatus as claimed in  claim 90 , wherein the paste-forming vehicle is a paste-forming vehicle system comprising a solvent selected from the group consisting of silicates, glycol ethers, methoxypolyethylene glycol (“MPEG”), ethylene glycol, propylene glycol, ethylene oxide, propylene oxide, polyethylene glycol (“PEG”), PEG modified with various types of functional groups at the ends of a macromolecular chain, oil, water, alcohols, diethyl sulfate, diisobutyl carbinol, diisobutyl ketone, hexylene glycol, isobutyl acetate, isophorone, isopropyl acetate, methyl isobutyl carbinol, ketone, n-butyl acetate, n-propyl acetate, primary amyl acetate mixed isomers, primary amyl alcohol mixed isomers, n-propyl propionate, n-butyl propionate, n-pentyl propionate, methylene chloride, perchloroethylene, trichloroethylene, xylene, acetone, ethyl acetate, and chemically related substances.  
     
     
         93 . The apparatus as claimed in  claim 90 , wherein the solvent is an organic solvent.  
     
     
         94 . The apparatus as claimed in  claim 93 , wherein the solvent is polyethylene glycol.  
     
     
         95 . The apparatus as claimed in  claim 90 , wherein the paste-forming vehicle is a paste-forming vehicle system comprising a solute selected from the group consisting of cellulosic resin, thermoplastic resin, glycidyl methacrylate, hydroxy(meth)acrylate monomers, epsilon-caprolactone monomer, hydroxypropyl acrylate, hydroxyethyl acrylate, ethylene acrylic acid, divinylbenzene, styrene-butadiene latexes, acrylic latexes, vinyl acrylic latexes, styrene acrylic latexes, vinyl versatate latexes, vinyl chloride, vinylbenzyl chloride, chloromethylstyrene, vinyl acetate copolymers, epoxy resins, epoxy acrylate, aminoethylethanolamine, glycol ethers, propylene glycols, ethylene glycols, polyols, ethylene acrylic acid resins, methylcellulose, ethyl cellulose, hydroxyethyl cellulose, polyvinyl alcohol, starch, and chemically related substances.  
     
     
         96 . The apparatus as claimed in  claim 94 , wherein the paste-forming vehicle system comprises ethyl cellulose as a solute.  
     
     
         97 . The apparatus as claimed in  claim 96 , wherein the amount of ethyl cellulose present in the paste is in the range of about 3 to about 5 vol. %.  
     
     
         98 . The apparatus as claimed in  claim 97 , wherein the amount of ethyl cellulose present in the paste is about 3 vol. %.  
     
     
         99 . The apparatus as claimed in  claim 96 , wherein the amount of carbon particles dispersed in the paste is less than about 2 vol. %.  
     
     
         100 . The apparatus as claimed in  claim 99 , wherein the amount of carbon particles dispersed in the paste is less than about 1.50 vol. %.  
     
     
         101 . The apparatus as claimed in  claim 98 , wherein the amount of carbon particles dispersed in the paste is less than about 1.50 vol. %.  
     
     
         102 . The apparatus as claimed in  claim 101 , wherein the amount of carbon particles dispersed in the paste is about 1.25 vol. %.  
     
     
         103 . The apparatus as claimed in  claim 102 , wherein the porous agglomerates of carbon particles comprise a carbon black.  
     
     
         104 . The apparatus as claimed in  claim 93 , wherein the solvent is di(ethylene glycol).  
     
     
         105 . The apparatus as claimed in  claim 104 , wherein the paste-forming vehicle system comprises ethyl cellulose as a solute.  
     
     
         106 . The apparatus as claimed in  claim 105 , wherein the amount of ethyl cellulose present in the paste is about 40 vol. %.  
     
     
         107 . The apparatus as claimed in  claim 105 , wherein the amount of carbon particles dispersed in the paste is less than about 0.40 vol. %.  
     
     
         108 . The apparatus as claimed in  claim 106 , wherein the amount of carbon particles dispersed in the paste is less than about 0.40 vol. %.  
     
     
         109 . The apparatus as claimed in  claim 108 , wherein the amount of carbon particles dispersed in the paste is about 0.20 vol. %.  
     
     
         110 . The apparatus as claimed in  claim 109 , wherein the porous agglomerates of carbon particles comprise a carbon black.