Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D7/00—Features of coating compositions, not provided for in group C09D5/00; Processes for incorporating ingredients in coating compositions
  • C09D7/40—Additives
  • C09D7/48—Stabilisers against degradation by oxygen, light or heat
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
  • C09D5/004—Reflecting paints; Signal paints
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
  • C09D5/02—Emulsion paints including aerosols
  • C09D5/024—Emulsion paints including aerosols characterised by the additives
  • C09D5/028—Pigments; Filters
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
  • C09D5/08—Anti-corrosive paints
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D7/00—Features of coating compositions, not provided for in group C09D5/00; Processes for incorporating ingredients in coating compositions
  • C09D7/40—Additives
  • C09D7/60—Additives non-macromolecular
  • C09D7/61—Additives non-macromolecular inorganic
• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04D—ROOF COVERINGS; SKY-LIGHTS; GUTTERS; ROOF-WORKING TOOLS
  • E04D5/00—Roof covering by making use of flexible material, e.g. supplied in roll form
  • E04D5/10—Roof covering by making use of flexible material, e.g. supplied in roll form by making use of compounded or laminated materials, e.g. metal foils or plastic films coated with bitumen
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K3/00—Use of inorganic substances as compounding ingredients
  • C08K3/02—Elements
  • C08K3/04—Carbon
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
  • Y02B80/00—Architectural or constructional elements improving the thermal performance of buildings
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/25—Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles
  • Y10T428/254—Polymeric or resinous material
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/26—Web or sheet containing structurally defined element or component, the element or component having a specified physical dimension
  • Y10T428/263—Coating layer not in excess of 5 mils thick or equivalent
  • Y10T428/264—Up to 3 mils
  • Y10T428/265—1 mil or less
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/31504—Composite [nonstructural laminate]
  • Y10T428/31678—Of metal
  • Y10T428/31692—Next to addition polymer from unsaturated monomers

Definitions

• the present invention relates to coated sheet materials having high solar reflective index and corrosion resistance, and methods of making such coated sheet materials.
• Sheet materials used in architectural and other applications often require corrosion resistant properties.
• steel and other types of metal roofing sheet materials must withstand exposure to environmental conditions for extended periods of time.
• Galvanized steel roofing sheets have conventionally been pre-treated with cliromium-containing compositions to increase corrosion resistance. Such pretreatments may be conducted on long strips of the steel, which are then coiled into rolls for subsequent use.
• Galvanized steel and other types of metal roofing materials may have high solar reflectance properties, but they tend to heat up when exposed to sunlight due to their low thermal emittance properties. As a result of such solar heating, the underlying structures can require significant amounts of energy to cool, e.g., by air conditioning.
• Solar reflective index is calculated based upon the combination of solar reflectance and thermal emittance, with an SRI value of 65, 70 or higher being required to meet certain government regulations.
• Solar reflectance is measured as a percentage of solar radiation in the visible, infrared and ultraviolet regions of the electromagnetic spectrum that is reflected from a surface, with a value of 0 or 0% corresponding to zero reflectance and a value of 1 or 100% corresponding to total reflectance.
• Thermal emittance is measured as the ability of a surface to shed heat, with a value of 0 or 0% corresponding to zero thermal emittance and a value of 1 or 100% corresponding to total thermal emittance.
• metal roofing with both relatively high solar reflectance and thermal emittance is desired.
• An aspect of the invention provides a coated metal sheet comprising a metal substrate, and a cured coating covering at least a portion of the metal substrate, wherein: (a) the cured coating: (i) is deposited from a composition comprising a latex resin, (ii) is substantially clear, (iii) is substantially free of reflective pigments, and (iv) has a dry film thickness of at least 1 micron; and (b) the coated metal sheet has a solar reflective index of at least 65 and a corrosion resistance of at least 500h with no corrosion spots when subjected to an ASTMB117 salt spray test.
• Another aspect of the invention provides a coated roof sheeting material comprising a sheet metal substrate, and a coating covering at least a portion of the sheet metal substrate, wherein the coating consists essentially of a cured latex resin, and wherein the coated roof sheeting material has a solar reflectance of at least 65 percent, a thermal emittance of at least 40 percent, and a corrosion resistance of at least 500h with no corrosion spots when subjected to an ASTMB117 salt spray test.
• a further aspect of the invention provides a method of coating a sheet metal substrate comprising applying a coating composition comprising a latex resin that is substantially free of reflective pigments to the sheet metal substrate at a wet film thickness of at least 1 micron, and curing the coating composition to produce a coated metal sheet having a solar reflective index of at least 65 and a corrosion resistance of at least 500h with no corrosion spots when subjected to an ASTMB117 salt spray test.
• Fig. 1 is a partially schematic side view of a coated roof sheeting material in accordance with an embodiment of the present invention, illustrating solar reflectance and thermal emittance properties.
• Fig. 2 is a partially schematic side view illustrating a method of coating and coiling metal sheets in rolling mill, including the use of a roll coater for applying a coating composition to the sheets in accordance with an embodiment of the present invention.
• Fig. 3 is a graph of total solar reflectance (TSR) vs. dry film thickness (DFT) for coated metal sheets in accordance with embodiments of the present invention.
• Fig. 4 is a graph of thermal emittance (TE) vs. DFT for coated metal sheets in accordance with embodiments of the present invention.
• Fig. 5 is a graph of solar reflective index (SRI) vs. DFT for coated metal sheets in accordance with embodiments of the present invention.
• Fig. 6 is a graph of TSR vs. DFT for coated metal sheets in accordance with embodiments of the present invention.
• Fig. 7 is a graph of TE vs. DFT for coated metal sheets in accordance with embodiments of the present invention.
• Fig. 8 is a graph of SRI vs. DFT for coated metal sheets in accordance with embodiments of the present invention.
• Fig. 1 schematically illustrates a coated sheet material 10 in accordance with an embodiment of the present invention including a substrate sheet 12 and a coating layer 14.
• the coated sheet 10 may be used in architectural applications, such as roof sheeting material for a building 16 or other structure.
• the coating 14 has a dry film thickness T typically greater than 1 micron, for example, greater than 2 or 3 microns. In certain embodiments, the dry film thickness T of the coating 14 may be from 3 to 10 or 20 microns.
• the substrate sheet 12 may be of any desired thickness, such as from 0.5 to 3 mm. For example, the thickness of galvanized steel roof sheeting materials may range from 0.5 to 2 mm in certain embodiments.
• the sheet 12 shown in Fig. 1 is flat, any other shape may be provided, such as corrugated, ribbed, and the like.
• total solar reflectance means a measure of the ability of a surface material to reflect sunlight - including the visible, infrared, and ultraviolet wavelengths - on a scale of 0% to 100%.
• the total solar reflectance TSR of the coated sheet 10 is at least 60%, for example, at least 62% or 65%.
• the coated sheet 10 has thermal emittance TE properties.
• thermal emittance refers to the ability of a material to release absorbed heat. A number between 0 and 1 , or 0% and 100%, is used to express emittance.
• the thermal emittance TE of the coated sheet 10 is at least 0.3 (30%), for example, at least 0.4 (40%) or 0.5 (50%).
• the total solar reflectance TSR and emittance TE properties may be combined to yield a solar reflective index ("SRI").
• SRI solar reflective index
• the term "solar reflective index” is a value that incorporates both solar reflectance and emittance in a single value to represent a material's temperature in the sun. SRI quantifies how hot a surface would get relative to standard black and standard white surfaces. It is calculated using equations based on previously measured values of solar reflectance and emittance as laid out in the American Society for Testing and Materials Standard E 1980. In accordance with ASTM Standard E 1980, values of TSR and TE are input into a standard equation to calculate the SRI value.
• the solar reflective index SRI is at least 65, for example, at least 70 or 75.
• the coating composition comprises a latex resin.
• the latex resin may, or may not, be self- crosslinking.
• the latex resin typically comprises from 20 to 60 weight percent of the coating composition, for example, from about 30 to about 50 weight percent.
• suitable monomers used for preparing the latex resins may include vinyl aromatic monomers such as styrene, cyclo aliphatic monomers such as cyclohexyl methacrylate, and long-chain aliphatic monomers such as 2-ethylhexyl acrylate, MMA and/or 2-ethylhexyl methacrylate.
• monomers include cyclohexene, 2-ethyl-l-hexene, cyclohexanol, alpha- methylstyrene, 2-ethylhexanol, 2- ethylhexyl acetate, methyl-4-phenyl butyrate, methyl myristate and/or methyl palmitate.
• the monomers used in the latex resin comprise a vinyl aromatic compound, such as a vinyl aromatic monomer, which, in certain embodiments, comprises a compound that has a calculated Tg of least 100°C.
• vinyl aromatic compounds are styrene (which has a calculated Tg of 100°C), a-methylstyrene (which has a calculated Tg of 168°C), vinyltoluene, p- methylstyrene, ethylvinylbenzene, vinylnaphthalene, vinylxylenes, a-methylstyrene dimer (meth)acrylate, penta fiuoro styrene, and the like.
• styrene or another vinyl aromatic monomer may comprise the most predominant monomer of the resin on a weight percent basis.
• the monomers of the latex resin include cycloaliphatic (meth)acrylate monomers, such as trimethylcyclohexyl acrylate, t-butyl cyclohexyl acrylate, dicyclopentadiene (meth)acrylate, trimethylcyclohexyl methacrylate (calculated Tg of 98°C), cyclohexyl methacrylate (calculated Tg of 83°C), isobornyl methacrylate (calculated Tg of 110°C), 2-ethylhexyl methacrylate, tetrahydrofurfuryl methacrylate, 3, 3, 5 -trimethylcyclohexyl methacrylate (calculated Tg of 125°C), and/or 4-t-butylcyclohexyl methacylate, and the like.
• cycloaliphatic (meth)acrylate monomers such as trimethylcyclohexyl acrylate, t-butyl
• the monomers of the latex resin include an alkyl(meth)acrylate, which, in certain embodiments, comprises a compound that has a calculated Tg of least 100°C.
• alkyl(meth)acrylates are Ci-C 24 alkyl(meth)acrylates, such as methyl(meth) acrylate (which has a calculated Tg of 105°C), propyl(meth)acrylate, butyl(meth)acrylate, isobutyl(meth)acrylate, hexyl(meth) acrylate, 2-ethylhexyl(meth)acrylate, octyl(meth)acrylate,
• decyl(meth)acrylate dodecyl(meth) acrylate, pentadecyl(meth)acrylate,
• hexadecyl(meth)acrylate octadecyl(meth)acrylate
• nonadecyl(meth)acrylate and mixtures thereof.
• Other monomers include, for example, nitriles, such as acrylonitrile and/or methacrylonitrile.
• latex resins that may be used in the coating compositions of the present invention are commercially available from Nuplex, Lubrizol, Rohm and Haas, Alberdingk Boley Company, Omnova and DSM Neoresins, such as Joncryl 1982, Caroboset CR-781 , Alberdingk AC 2403, Alberdingk 2360, Neocryl XK-98 and the like.
• the latex resin may have an average particle size of from 50 nm to 300 nm, for example from 60 nm to 100 or 150 nm; a glass transition temperature (T G ) of from -20 to 100°C, typically from zero to 20 or 50°C; and an acid number of from 0 to 20, typically from 2 to 10.
• T G glass transition temperature
• the coating compositions of the present invention may be waterborne.
• water may comprise from 20 to 80 weight percent of the coating compositions, for example, from 50 to 65 weight percent.
• the coating compositions comprise less than 10 weight percent organic solvents, for example, less than 7 or 4 weight percent, based on the total weight of the composition.
• the resin solids content of the coating compositions may be relatively high, for example, greater than 35 or 40 weight percent, based on the total weight of the composition.
• the coating compositions may have little or no volatile organic content (VOC).
• the coating compositions may comprise less than 1.5 weight percent VOCs, for example, less than 1 or 0.5 weight percent VOCs, based on the total weight of the composition.
• the coating compositions are substantially free of VOCs.
• the coating compositions may further comprise at least one coalescing agent in an amount of up to 10 weight percent, for example, in an amount of from 2 to 3 weight percent, based on the total weight of the coating composition.
• suitable coalescing agents include butyl carbitol commercially available from Dow Chemical Company, Dowanol DPM, Dowanol DPnB, Dowanol PPh, butyl cellosolve or Dowanol DPnP.
• the coalescing agents form a thin film around the latex resin particles, which helps them coalesce.
• the average resin particle size may be less than 150 nanometers, for example, less than 100 or 80 nanometers.
• wax may be added to the coating compositions in amounts up to 10 weight percent, for example, from 0.5 to 3 weight percent, based on the total weight of the coating composition.
• Suitable types of wax include
• wax sold under the designation Aquamat 272 by BYK Chemie may be used.
• the type and amount of wax may be controlled in order to improve scratch resistance of the coated sheet materials.
• the use of wax additives may reduce or prevent scratching during the coiling an uncoiling processes, as well as during subsequent installation and use of the coated sheet materials.
• the amount of wax added to the coating composition is limited in order to avoid unwanted slippage when the coated sheets are coiled, e.g., to prevent unwanted "telescoping" of the coils due to low friction between the adjacent coil layers.
• additives may optionally be added to the coating compositions in accordance with certain embodiments of the invention.
• suitable additives include thickeners, defoamers, surfactants, rust inhibitors, pH control agents, silica, and tints.
• Suitable thickeners include Acrysol ASE-60, Aquatix 8421 , DSX- 1550, and Laponite RD. When used, such thickening agents may be present in amounts up to 7 weight percent, for example, from 0.5 to 4 weight percent, based on the total weight of the coating composition.
• Suitable defoamers include BYK-011 , BYK-20, BYK-32, BYK 34 and Drewplus L-419 available from Ashland in amounts up to 2 weight percent, for example, from 0.1 to 0.5 weight percent, based on the total weight of the coating composition.
• Suitable surfactants include Zonyl FSP available from DuPont, Surfynol 104E available from Air Products, BYK 346, and BYK348 in amounts up to 2 weight percent, for example, from 0.1 to 0.5 weight percent, based on the total weight of the coating composition.
• Suitable rust inhibitors include Halox 550, Halox Hash X- 150, 330, Halox SZP-391, ammonium benzoate, and sodium nitrite in typical amounts up to 1 weight percent, for example, from 0.4 to 0.6 weight percent, based on the total weight of the coating composition.
• the coating compositions are substantially free of certain metal salts such as metal phosphates, phosphocarbonates and
• compositions may be substantially free of zinc phosphate, calcium phosphate, calcium phosphosilicate and/or calcium-enriched silica.
• Suitable pH control agents include any water soluble amine such as dimethylethanol amine (DMEA) available from Avecia in typical amounts up to 1 weight percent, for example, from 0.01 to 0.2 weight percent, based on the total weight of the coating composition.
• DMEA dimethylethanol amine
• the coatings are substantially free of chrome.
• chrome is not purposely added to the coating compositions and is only present in trace levels or as an impurity.
• chromate-containing materials may be added to the coating compositions.
• Such chromate-containing coating compositions may be particularly useful as primer coatings.
• strontium chromate may be added in amounts up to 12 weight percent, for example, from 0.2 to 1 weight percent, based on the total weight of the coating composition.
• strontium chromate-containing additives may provide improved corrosion resistance properties.
• the coating compositions may further include colorants and tints typically used in primers, such as titanium dioxide and the like.
• silica may be added to the coating
• compositions for example, in amounts from 0.1 to 2 or 3 weight percent or more.
• silica include Lo-Vel 275 silica from PPG Industries and Aerosil 200 silica from Air Products.
• the coating compositions and cured coatings are substantially free of reflective pigments.
• the term "reflective pigment” means plate-like or sheet-like interference pigments such as mica, silicates, silicon dioxide and aluminum oxide. Solarfiair 9870 from Eckart is an example of a reflective pigment.
• the term “substantially free of reflective pigments” means that the coatings have zero or minimal amounts of reflective pigments while achieving the desired level of solar reflectance and/or solar reflective index.
• the cured coatings may have less than 2 or 1 weight percent reflective pigment.
• the coatings may be substantially free of reflective pigments, they still maintain sufficient solar reflectance properties and solar reflective index values, e.g., SRIs of 65 or greater. The cost of reflective pigment additives may thus be avoided, while still providing a desired level of solar reflectance.
• At least one colored pigment or tint may be added to the coating compositions.
• Colored pigments and tints are different from reflective interference pigments and include standard inorganic and organic pigments, such as those found in conventional paints and primers.
• various colored pigments are listed in the Dry Color Manufacturers Association (DCMA)
• Such colored pigments and tints typically comprise particles having substantially equiaxed morphologies, e.g., aspect ratios of about 1 : 1, in comparison with plate-like and sheet-like reflective interference pigments having relatively high aspect ratios.
• One suitable type of colored pigment includes T1O 2 in an amount up to 35 weight percent, for example, from 1 to 25 weight percent, based on the total weight of the coating composition.
• Aquext white tint commercially available from PPG Industries and Corrosperse 176E chrome tint commercially available from Wayne Pigments are examples of suitable tints.
• the coating is substantially free of colored pigments and tints.
• the coatings may be substantially clear and colorless.
• conductive particles such as graphenic carbon particles may be added to the coating compositions in amounts of to 5 weight percent, for example, from 1 to 2 weight percent, based on the total weight of the coating composition.
• Such graphenic carbon particles may provide improved thermal emissivity properties.
• the graphenic carbon particles may be obtained from commercial sources, or may be made in accordance with the methods and apparatus described in U.S. Application Serial Nos. 13/249,315 and 13/309,894, which are incorporated herein by reference. Exemplary commercially available graphenic carbon particles are available from Angstron and XG Sciences.
• grapheme carbon particles means carbon particles having structures comprising one or more layers of one-atom-thick planar sheets of sp 2 -bonded carbon atoms that are densely packed in a honeycomb crystal lattice.
• the average number of stacked layers may be less than 100, for example, less than 50. In certain embodiments, the average number of stacked layers is 30 or less, such as 20 or less, 10 or less, or, in some cases, 5 or less.
• the grapheme carbon particles may be substantially flat, however, at least a portion of the planar sheets may be substantially curved, curled, creased or buckled. The particles typically do not have a spheroidal or equiaxed morphology.
• the graphenic carbon particles present in the compositions of the present invention have a thickness, measured in a direction perpendicular to the carbon atom layers, of no more than 10 nanometers, no more than 5 nanometers, or, in certain embodiments, no more than 4 or 3 or 2 or 1 nanometers, such as no more than 3.6 nanometers.
• the graphenic carbon particles may be from 1 atom layer up to 3, 6, 9, 12, 20 or 30 atom layers thick, or more.
• the graphenic carbon particles present in the compositions of the present invention have a width and length, measured in a direction parallel to the carbon atoms layers, of at least 50 nanometers, such as more than 100 nanometers, in some cases more than 100 nanometers up to 500 nanometers, or more than 100 nanometers up to 200 nanometers.
• the graphenic carbon particles may be provided in the form of ultrathin flakes, platelets or sheets having relatively high aspect ratios (aspect ratio being defined as the ratio of the longest dimension of a particle to the shortest dimension of the particle) of greater than 3:1 , such as greater than 10:1.
• the graphenic carbon particles used in the compositions of the present invention have relatively low oxygen content.
• the graphenic carbon particles used in certain embodiments of the compositions of the present invention may, even when having a thickness of no more than 5 or no more than 2 nanometers, have an oxygen content of no more than 2 atomic weight percent, such as no more than 1.5 or 1 atomic weight percent, or no more than 0.6 atomic weight, such as about 0.5 atomic weight percent.
• the oxygen content of the graphenic carbon particles can be determined using X-ray Photoelectron Spectroscopy, such as is described in D. R. Dreyer et al., Chem. Soc. Rev. 39, 228- 240 (2010).
• the graphenic carbon particles used in the compositions of the present invention have a B.E.T. specific surface area of at least 50 square meters per gram, such as 70 to 1000 square meters per gram, or, in some cases, 200 to 1000 square meters per grams or 200 to 400 square meters per gram.
• B.E.T. specific surface area refers to a specific surface area determined by nitrogen adsorption according to the ASTMD 3663-78 standard based on the Brunauer-Emmett-Teller method described in the periodical "The Journal of the American Chemical Society", 60, 309 (1938).
• the graphenic carbon particles used in the compositions of the present invention have a Raman spectroscopy 2D/G peak ratio of at least 1.1 , for example, at least 1.2 or 1.3.
• 2D/G peak ratio refers to the ratio of the intensity of the 2D peak at 2692 cm “1 to the intensity of the G peak at 1,580 cm "1 .
• the graphenic carbon particles used in the compositions of the present invention have a relatively low bulk density.
• the graphenic carbon particles used in certain embodiments of the present invention are characterized by having a bulk density (tap density) of less than 0.2 g/cm 3 , such as no more than 0.1 g/cm 3 .
• the bulk density of the graphenic carbon particles is determined by placing 0.4 grams of the graphenic carbon particles in a glass measuring cylinder having a readable scale. The cylinder is raised approximately one -inch and tapped 100 times, by striking the base of the cylinder onto a hard surface, to allow the graphenic carbon particles to settle within the cylinder. The volume of the particles is then measured, and the bulk density is calculated by dividing 0.4 grams by the measured volume, wherein the bulk density is expressed in terms of g/cm 3 .
• the graphenic carbon particles used in the compositions of the present invention have a compressed density and a percent densification that is less than the compressed density and percent densification of graphite powder and certain types of substantially fiat graphenic carbon particles.
• Lower compressed density and lower percent densification are each currently believed to contribute to better dispersion and/or rheo logical properties than graphenic carbon particles exhibiting higher compressed density and higher percent densification.
• the compressed density of the graphenic carbon particles is 0.9 or less, such as less than 0.8, less than 0.7, such as from 0.6 to 0.7.
• the percent densification of the graphenic carbon particles is less than 40%, such as less than 30%, such as from 25 to 30%.
• the compressed density of graphenic carbon particles is calculated from a measured thickness of a given mass of the particles after compression. Specifically, the measured thickness is determined by subjecting 0.1 grams of the graphenic carbon particles to cold press under 15,000 pound of force in a 1.3 centimeter die for 45 minutes, wherein the contact pressure is 500 MPa. The compressed density of the graphenic carbon particles is then calculated from this measured thickness according to the following equation:
• the percent densification of the graphenic carbon particles is then determined as the ratio of the calculated compressed density of the graphenic carbon particles, as determined above, to 2.2 g/cm 3 , which is the density of graphite.
• the graphenic carbon particles have a measured bulk liquid conductivity of at least 100 microSiemens, such as at least 120
• percolation occurs between the conductive graphenic carbon particles.
• Such percolation may reduce the resistivity of the coating compositions.
• the conductive graphenic particles may occupy a minimum volume within the coating such that the particles form a continuous, or nearly continuous, network.
• the aspect ratios of the graphenic carbon particles may affect the minimum volume required for percolation.
• the surface energy of the graphenic carbon particles may be the same or similar to the surface energy of the elastomeric rubber. Otherwise, the particles may tend to flocculate or demix as they are processed.
• the graphenic carbon particles utilized in the compositions of the present invention can be made, for example, by thermal processes.
• the graphenic carbon particles are produced from carbon-containing precursor materials that are heated to high temperatures in a thermal zone.
• the graphenic carbon particles may be produced by the systems and methods disclosed in United States Patent Application Serial Nos. 13/249,315 and 13/309,894.
• the graphenic carbon particles may be made by using the apparatus and method described in United States Patent Application Serial No. 13/249,315 at [0022] to [0048] in which (i) one or more hydrocarbon precursor materials capable of forming a two-carbon fragment species (such as n-propanol, ethane, ethylene, acetylene, vinyl chloride, 1,2-dichloroethane, allyl alcohol, propionaldehyde, and/or vinyl bromide) is introduced into a thermal zone (such as a plasma); and (ii) the hydrocarbon is heated in the thermal zone to a temperature of at least 1 ,000°C to form the graphenic carbon particles.
• one or more hydrocarbon precursor materials capable of forming a two-carbon fragment species such as n-propanol, ethane, ethylene, acetylene, vinyl chloride, 1,2-dichloroethane, allyl alcohol, propionaldehyde, and/or vinyl bromide
• the graphenic carbon particles may be made by using the apparatus and method described in United States Patent AppUcation Serial No. 13/309,894 at [0015] to [0042] in which (i) a methane precursor material (such as a material comprising at least 50 percent methane, or, in some cases, gaseous or liquid methane of at least 95 or 99 percent purity or higher) is introduced into a thermal zone (such as a plasma); and (ii) the methane precursor is heated in the thermal zone to form the graphenic carbon particles.
• a methane precursor material such as a material comprising at least 50 percent methane, or, in some cases, gaseous or liquid methane of at least 95 or 99 percent purity or higher
• a thermal zone such as a plasma
• the methane precursor is heated in the thermal zone to form the graphenic carbon particles.
• a carbon-containing precursor is provided as a feed material that may be contacted with an inert carrier gas.
• the carbon-containing precursor material may be heated in a thermal zone, for example, by a plasma system.
• the precursor material is heated to a temperature ranging from 1,000°C to 20,000°C, such as 1,200°C to 10,000°C.
• the temperature of the thermal zone may range from 1,500 to 8,000°C, such as from 2,000 to 5,000°C.
• the thermal zone may be generated by a plasma system, it is to be understood that any other suitable heating system may be used to create the thermal zone, such as various types of furnaces including electrically heated tube furnaces and the like.
• the gaseous stream may be contacted with one or more quench streams that are injected into the plasma chamber through at least one quench stream injection port.
• the quench stream may cool the gaseous stream to facilitate the formation or control the particle size or morphology of the graphenic carbon particles.
• the ultrafine particles may be passed through a converging member. After the graphenic carbon particles exit the plasma system, they may be collected. Any suitable means may be used to separate the graphenic carbon particles from the gas flow, such as, for example, a bag filter, cyclone separator or deposition on a substrate.
• graphenic carbon particles are particularly suitable for producing graphenic carbon particles having relatively low thickness and relatively high aspect ratio in combination with relatively low oxygen content, as described above. Moreover, such methods are currently believed to produce a substantial amount of graphenic carbon particles having a substantially curved, curled, creased or buckled morphology (referred to herein as a "3D" morphology), as opposed to producing predominantly particles having a substantially two-dimensional (or flat) morphology.
• Fig. 2 schematically illustrates a roll coating method for applying coating compositions onto sheet materials in accordance with an embodiment of the present invention.
• the coating operation may be conducted in a conventional rolling mill.
• Metal sheet material such as galvanized steel or the like, is provided in a long strip 5 that passes under oppositely-rotating coating rollers 20 and 22, which are fed with a supply of a coating composition 24.
• the uncoated strip 5 passes under the coating rollers 20 and 22, where a layer of the coating composition 24 is deposited on the upper surface of the sheet material.
• the coated sheet material 10 may be formed into a coil 26 for storage and transportation for use in various applications, such as galvanized steel roof sheeting.
• the coating composition is typically applied to the sheet material 5 with a wet film thickness of at least 1 micron, typically at least 1 or 5 microns. In certain embodiments, the wet film thickness of the coating material is from 5 to 15 or 20 microns. In certain embodiments, the deposition rate of the coating composition may be at least 200 ft/min, typically at least 300 ft/min or 350 ft/min.
• the coating compositions typically dry and cure quickly with minimal VOC emissions. Curing times are typically in less than 1 minute, for example, less than 10 or 5 seconds. Typical curing temperatures are below 300°F, for example, below 275° or 250°F. In certain embodiments, curing times may be less than 3 or 2 seconds at temperatures of 225°F or 200°F, or less. [0065]
• the dry film thickness of the cured coating is typically at least 1 micron up to 15 or 20 microns. For example, the dry film thickness may be from 5 to 10 microns. In accordance with the present invention, such relatively thin coating layers have been found to significantly increase the solar reflective index of metal roof sheeting materials.
• Coating compositions were prepared and tested as described in Tables 1-4 below.
• ASTM Bl 17 panels are placed with taped cut edges in a 95F/5% NaCl solution cabinet for 1000 hours. The panels are then removed from the cabinet and visually evaluated for any red or white rust, black spots and blister defects on the faces of the panels.
• ASTM D7376-10A panels are sprayed with Dl-water, stacked face to face, and clipped together in a bundle to simulate a wound coil.
• the bundles are placed in a 1 OOF/100% humidity cabinet for 1000 hours.
• the bundles are then removed and visually evaluated for dark stains or white stains (pressure mottling).
• Sample No. 5 included graphenic carbon particles produced in accordance with U.S. Patent Application Serial No. 13/309,894.
• Sample No. 6 included commercially available graphenic carbon particles from Angstron sold under the designation N-006-010-P.
• Sample No. 7 included commercially available graphenic carbon particles from XG Sciences sold under the designation X-GNP-M-25. Panels were prepared by drawdown on a galvanized steel substrate at a film thickness of 5 microns. The panels were then cured at peak metal temperature of 190°F for 2 seconds using a conveyer oven. The panels were tested, with the results shown below in Table 4. Table 4
• any numerical range recited herein is intended to include all sub-ranges subsumed therein.
• a range of "1 to 10" is intended to include all sub-ranges between (and including) the recited minimum value of 1 and the recited maximum value of 10, that is, having a minimum value equal to or greater than 1 and a maximum value of equal to or less than 10.

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• Chemical & Material Sciences (AREA)
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• Organic Chemistry (AREA)
• Wood Science & Technology (AREA)
• Life Sciences & Earth Sciences (AREA)
• Dispersion Chemistry (AREA)
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• 2013
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