Source: http://patents.com/us-10057986.html
Timestamp: 2019-01-17 00:19:16
Document Index: 459281102

Matched Legal Cases: ['Application No. 2672', 'application No. 200680038183', 'Application No. 2008', 'Application No. 2', 'Application No. 10', 'Application No. 06', 'Application No. 2672']

US Patent # 1,005,7986. Thermal overload device containing a polymer composition containing thermally exfoliated graphite oxide and method of making the same - Patents.com
United States Patent 10,057,986
Prud'Homme , et al. August 21, 2018
Thermal overload device containing a polymer composition containing thermally exfoliated graphite oxide and method of making the same
A thermal overload device containing a polymer composite, which contains at least one polymer and a modified graphite oxide material, containing thermally exfoliated graphite oxide having a surface area of from about 300 m.sup.2/g to 2600 m.sup.2/g, and a method of making the same.
Family ID: 37963005
15/459,973
US 20170318672 A1 Nov 2, 2017
14515019 Oct 15, 2014 9642254
Current CPC Class: H01G 4/206 (20130101); B82Y 30/00 (20130101); B82Y 40/00 (20130101); H05K 1/095 (20130101); H05K 3/0091 (20130101); H05K 3/10 (20130101); C01B 32/23 (20170801); C01B 32/225 (20170801); C01B 32/192 (20170801); C01B 31/0476 (20130101); C01B 31/043 (20130101); C01B 31/0423 (20130101); C01B 2204/32 (20130101); H05K 2201/0323 (20130101); Y10T 428/13 (20150115); Y10T 428/1341 (20150115); Y10T 428/2982 (20150115); Y10T 428/1379 (20150115); Y02E 60/324 (20130101); Y02E 60/325 (20130101); Y02E 60/328 (20130101)
Current International Class: B82Y 30/00 (20110101); H01G 4/20 (20060101); C01B 32/192 (20170101); H05K 3/00 (20060101); H05K 3/10 (20060101); C01B 32/225 (20170101); C01B 32/23 (20170101); H05K 1/09 (20060101); B82Y 40/00 (20110101)
Office Action dated Jul. 26, 2011 in Indian Patent Application No. 2672/DELNP/2008. cited by applicant .
Chinese Office Action dated Feb. 21, 2012 in patent application No. 200680038183.X. cited by applicant .
Office Action dated Jun. 26, 2012, in Japanese Patent Application No. 2008-535562. cited by applicant .
Office Action dated Sep. 12, 2012 in Canadian Patent Application No. 2,623,451. cited by applicant .
Korean Office Action dated Apr. 25, 2013 in Patent Application No. 10-2008-7009095. cited by applicant .
Office Action dated Dec. 11, 2013 in European Patent Application No. 06 836 165.8. cited by applicant .
Office Action dated May 22, 2014 in Indian Patent Application No. 2672/DELNP/2008. cited by applicant.
This application is a Continuation of U.S. patent application Ser. No. 14/515,019, filed Oct. 15, 2014, now allowed, which was a Continuation of U.S. patent application Ser. No. 13/077,070, filed Mar. 31, 2011, now U.S. Pat. No. 8,891,247, which was a Divisional of U.S. patent application Ser. No. 12/194,030, filed Aug. 19, 2008, now U.S. Pat. No. 8,048,214, which was a Continuation of U.S. patent application Ser. No. 11/249,404, filed Oct. 14, 2005, now U.S. Pat. No. 7,658,901, the entire contents of each of which are hereby incorporated by reference.
1. A thermal overload protective device, comprising: a conductive composition comprising: a polymer matrix; and thermally exfoliated graphite oxide configured to: comprise a surface area of from about 300 m.sup.2/g to 2,600 m.sup.2/g; display no signature of graphite and no signature of graphite oxide, as determined by X-ray diffraction; and comprise a wrinkle topology at the nanoscale that mechanically interlocks with the polymer matrix; wherein the conductive composition is configured to undergo an event when the conductive composition receives a threshold amount of heat or a current; wherein the event comprises at least one member selected from the group consisting of an expansion of the polymer matrix and a decrease in electrical conductivity.
2. The thermal overload protective device of claim 1, wherein the thermally exfoliated graphite oxide has a bulk density of from about 40 kg/m.sup.3 to 0.1 kg/m.sup.3.
3. The thermal overload protective device of claim 1, wherein the thermally exfoliated graphite oxide has a C/O ratio of from about 60/40 to 95/5.
4. The thermal overload protective device of claim 1, wherein the polymer matrix comprises a polymer selected from the group consisting of polyethylene, polypropylene and copolymers thereof, polyesters, nylons, polystyrenes, polycarbonates, polycaprolactones, polycaprolactams, fluorinated ethylenes, polyvinyl acetate and its copolymers, polyvinyl chloride, polymethylmethacrylate and acrylate copolymers, high impact polystyrene, styrenic sheet molding compounds, polycaprolactones, polycaprolactams, fluorinated ethylenes, styrene acrylonitriles, polyimides, epoxys, polyurethanes, poly[4,4'-methylenebis(phenyl isocyanate)-alt-1,4-butanediol/poly(butylene adipate)], poly[4,4'-methylenebis(phenyl isocyanate)-alt-1,4-butanediol/poly(butylene adipate)], poly[4,4'-methylenebis(phenyl isocyanate)-alt-1,4-butanediol/poly(butylene adipate)], poly[4,4'-methylenebis(phenyl isocyanate)-alt-1,4-butanediol/di(propylene glycol)/polycaprolactone, poly[4,4'-methylenebis(phenyl isocyanate)-alt-1,4-butanediol/polytetrahydrofuran, amine terminated polybutadienes, carboxyl terminated polybutadienes, polybutadiene, dicarboxy terminated butyl rubber, styrene/butadiene copolymers, polyisoprene, poly(styrene-co-butadiene), polydimethysiloxane, and natural latex rubber.
5. The thermal overload protective device of claim 1, wherein the conductive composition comprises a thermally exfoliated graphite oxide loading level of 0.1 to 90% by weight based on the total weight of the conductive composition.
6. The thermal overload protective device of claim 1, wherein the event further comprises a loss of percolation of the thermally exfoliated graphite oxide.
7. A method for making a thermal overload protective device, comprising the step of: pattering the thermal overload protective device by application of a fluid comprising: a polymer; a solvent; and a modified graphite oxide material, comprising: thermally exfoliated graphite oxide comprising: a surface area of from about 300 m.sup.2/g to 2,600 m.sup.2/g; an X-ray diffraction pattern that displays no signature of graphite and no signature of graphite oxide; and a wrinkled topology at the nanoscale that mechanically interlocks with the polymer; wherein the fluid is configured to form a conductive composition, the conductive composition configured to undergo an event when the conductive composition receives heat or a current, the event comprising at least one member selected from the group consisting of an expansion of the polymer matrix and a decrease in electrical conductivity.
8. The method of claim 7, further comprising drying the fluid.
9. The method of claim 7, wherein the thermally exfoliated graphite oxide has a bulk density of from about 40 kg/m.sup.3 to 0.1 kg/m.sup.3.
10. The method of claim 7, wherein the thermally exfoliated graphite oxide has a C/O ratio of from about 60/40 to 95/5.
11. The method of claim 7, wherein the polymer comprises material selected from the group consisting of polyethylene, polypropylene and copolymers thereof, polyesters, nylons, polystyrenes, polycarbonates, polycaprolactones, polycaprolactams, fluorinated ethylenes, polyvinyl acetate and its copolymers, polyvinyl chloride, polymethylmethacrylate and acrylate copolymers, high impact polystyrene, styrenic sheet molding compounds, polycaprolactones, polycaprolactams, fluorinated ethylenes, styrene acrylonitriles, polyimides, epoxys, polyurethanes, poly[4,4'-methylenebis(phenyl isocyanate)-alt-1,4-butanediol/poly(butylene adipate)], poly[4,4'-methylenebis(phenyl isocyanate)-alt-1,4-butanediol/poly(butylene adipate)], poly[4,4'-methylenebis(phenyl isocyanate)-alt-1,4-butanediol/poly(butylene adipate)], poly[4,4'-methylenebis(phenyl isocyanate)-alt-1,4-butanediol/di(propylene glycol)/polycaprolactone, poly[4,4'-methylenebis(phenyl isocyanate)-alt-1,4-butanediol/polytetrahydrofuran, amine terminated polybutadienes, carboxyl terminated polybutadienes, polybutadiene, dicarboxy terminated butyl rubber, styrene/butadiene copolymers, polyisoprene, poly(styrene-co-butadiene), polydimethysiloxane, and natural latex rubber.
12. The method of claim 7, wherein the solvent comprises one or more of water, n-methylpyrolidone (NMP), dimethyformamide (DMF), tetrahydrofuran (THF), an alcohol, a glycol, an aliphatic ester, an aromatic ester, a phthalates, a dibutyl phthalate, a methylene chloride, an acetic ester, an aldehyde, a glycol ether, a propionic ester, and a chlorinated solvent.
13. The method of claim 12, wherein the glycol comprises one or more of ethylene glycol, propylene glycol, and butylene glycol.
14. The method of claim 7, wherein the event further comprises a loss of percolation of the thermally exfoliated graphite oxide.
15. The method of claim 7, wherein the solvent comprises water.
FIGS. 4a and 4b illustrate XRD patterns of TEGO and GO samples prepared by oxidation for 96 and 24 hours and rapidly expanded at 1050.degree. C. The incompletely oxidized GO in FIG. 4b produces a more pronounced peak at 2.THETA..apprxeq.26.50 after heat treatment.
Gases evolved during heating include water vapor from bound water between the GO layers, oxides of sulfur SO.sub.x and H.sub.2S from intercalated sulfates not removed by washing, oxides of nitrogen NO.sub.x if nitrates are used as intercalants, CO.sub.2, CO, and C.sub.nH.sub.mO.sub.o species from partial reduction and elimination of oxygenated species from the GO precursor. X, m, n, o are numbers, preferably integers. More than one kind of gas may evolve during the heating. In one embodiment, IR-spectra of the decomposition products in the vapor phase during exfoliation show the presence of SO.sub.2, CO.sub.2 and water in the unwashed GO sample and only CO.sub.2 and water in the washed sample. The SO2 arises from decomposition of the intercalated sulfate ions, and the CO.sub.2 comes from decomposition of oxygenated species on GO. Minor amounts of higher carbon number evolved gaseous products may be produced. And if nitrate intercalants are used there may be NOx species released.
The TEGO increases the conductivity of polymeric matrices by factors of 10.sup.11 to 10.sup.18 over the range of filler loadings between 0.1 to 20 wt %, preferably 1.5 and 5 wt %, based on the weight of the polymer composite or ink formulation. The amount of filler includes all values and subvalues there between, especially including 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4 and 4.5 wt %. This corresponds to conductivity increases from 10.sup.-19 S/m to 10.sup.-8-10.sup.-1 S/m for a 1.5 to 5 wt % loading of TEGO in PMMA. Higher conductivities above 0.01 to 1000 S/n can be attainable in more highly filled composite or ink formulations. The basic conductivity of the individual TEGO sheet is on the order of 1/2 to 1/10 of the conductivity of graphite based on the percentage of oxygens that disrupt the pure sp.sup.2 graphitic structure. Commonly reported values for the in-plane conductivity of pure graphite sheets are 2 to 5.times.10.sup.5 S/m.
Polar solvents into which TEGO can be dispersed include water, n-methylpyrolidone (NMP), dimethyformamide (DMF), tetrahydrofuran (THF), alcohols, glycols such as ethylene glycol, propylene glycol and butylene glycol, aliphatic and aromatic esters, phthalates such as dibutyl phthalate, chlorinated solvents such as methylene chloride, acetic esters, aldehydes, glycol ethers, propionic esters. Representative solvents of the desired classes can be found at the Dow Chemical web site (http://www.dow.com/oxvsolvents/prod/index.htm). The polar solvent may be used alone or in combination. Mixtures with non-polar solvents are possible.
Graphite oxide was prepared from Flake 1 graphite according to the method of Staudenmaier (L. Staudenmaier, Ber. Dtsh. Chem. Ges, 31, 1481, (1898)). Graphite (1 g) was added to a 500-ml round-bottom flask containing a stirred and cooled (0.degree. C.) mixture of concentrated sulfuric and nitric acid (2:1 v/v, 27 ml). Potassium chlorate (11 g) was then added gradually in small portions to ensure that the temperature of the reaction mixture did not rise above 30.degree. C. After the addition of potassium chlorate, the mixture was allowed to reach room temperature and stirring was continued for 96 h. Next, the mixture was poured into deionized water (1 l) and filtered over a 60-ml fritted funnel (coarse). The product was washed on the funnel with 5% aqueous HCl until sulfates were no longer detected (when 5-ml of the aqueous filtrate does not turn cloudy in the presence of one drop of saturated aqueous BaCl.sub.2) and then with deionized water (2.times.50 ml). The resulting graphite oxide was dried in an oven at 100.degree. C. for 24 h. Elemental analysis (Atlantic Microlab, Norcross, Ga.): C, 53.37%, O, 39.45%, H, 1.62%, N, 0.14%.
Graphite oxide (0.2 g) was placed in a 75-ml quartz tube equipped with a 14/20 ground glass joint. The tube was evacuated and backfilled with nitrogen three times and then attached to a nitrogen bubbler. Next, the GO was heated rapidly with a propane blow torch (Model TX9, BernzOmatic, Medina N.Y.) set at medium intensity until no further expansion of graphite oxide was observed (typically 15 s.). Elemental Analysis: C, 80.10%, O, 13.86%, H, 0.45%, N, 0%.
XPS measurements were performed using an Omicron ESCA Probe (Omicron Nanotechnology, Taunusstein, Germany) located at Northwestern University's Keck Interdisciplinary Surface Science Center with monochromated Al K.sub..alpha. radiation (h v=1486.6 eV). The sample was oriented with a 450 photoelectron take-off angle from the sample surface to the hemispherical analyzer. Data were collected using a 15-kV acceleration voltage at 20-mA power and vacuum of 10.sup.-9 mbar. An analyzer pass-energy of 50 eV with 500-meV steps was used for single-sweep survey scans. High-resolution spectra were averaged over three sweeps using an analyzer pass energy of 22 eV with 20-meV steps. TEGO samples were de-gassed overnight within the XPS chamber (10.sup.-3 mbar) prior to analysis. The raw C.sub.1s XPS data (FIG. 9) were analyzed using multipak and XPS peak 41 fitting software to determine the relative peak locations and areas in relation to standard binding energies for known carbon functionalities (Handbook of X-ray photoelectron spectroscopy, edited by J. Chestain, R. C. King Jr., Physical Electronic, Inc., Eden Prairie, USA (1992)). The main component at 284.6 eV is attributed to C in C--C bond. An additional component at 286.1 eV is attributed to C in --C--O-- or C--O--C moieties.
The TEGO used for nanocomposite was prepared via both methods A and B. Consistent composite properties were obtained regardless of the method of TEGO preparation. Depending on the wt % of the composite, each type of nano-filler was initially dispersed in tetrahydrofuran (THF, 10 ml) by bath sonication (Branson 3510, 335 W power) at room temperature. These solutions were then combined with a solution of PMMA in THF (10-30 ml). Shear mixing (Silverson, Silverson Machines, Inc., MA. USA) at 6000 rpm was then applied to the TEGO/PMMA and EG/PMMA systems for 60 min in ice-bath to reduce the frictional heat produced in polymer by the shear mixer while the SWNT/PMMA systems received additional bath sonication for 60 min (shear mixing was not used for SWNT/PMMA). The composite solutions were then coagulated with methanol, filtered under vacuum using polycarbonate filter paper (Millipore, Cat. No. TCTP04700; 10-.mu.m pore size), and dried at 80.degree. C. for 10 h to yield a solid flaky materials. Nano-filler/PMMA composite samples for mechanical testing were pressed into a thin film between stainless steel plates using 0.1-mm thick spacers in a Tetrahedron (San Diego, Calif.) hydraulic hot-press at 210.degree. C. under 2 MPa to approximately 0.12-0.15 mm thickness. A neat PMMA control sample was prepared in the same manner.
Composite samples were microwave plasma-etched (Plasma-Preen 11-862, Plasmatic Systems, N.J.) for 1 min at 2 Torr of O.sub.2 and 350 W of power. AC impedance measurements were performed using an impedance analyzer (1260 Solartron, Hampshire, UK) with a 1296 Solarton dielectric interface. The specimen was sandwiched between two copper electrodes that are held tightly together with two 2-mm thick polycarbonate plates. Electrically conductive colloidal graphite (Product no. 16053, Ted Pella Inc., Redding Calif., USA) was applied between the sample and copper electrode to avoid point-contacts caused through surface roughness of the nano-composites. Impedance values were taken for the nanocomposites between 0.01-10.sup.6 Hz. Conductivity of the polymer nanocomposites (see FIG. 15) is taken from the plateau at low frequencies at 0.1 Hz.
Hot-pressed composite samples having thickness about 0.1 mm were cut into strips that are 1-2 mm wide and 15-20 mm long. The strips were microwave plasma-etched (Plasma-Preen II-862, Plasmatic Systems, N.J.) for 1 min at 2 Torr of O.sub.2 and 350 W of power. Subsequently, 25-nm thick gold films were thermally deposited on the specimen surfaces: four pads on one side of the composite strip for the longitudinal measurements and one pad on two opposing sides of the strip for the transverse measurements. Pad spacing for longitudinal measurement were always 0.16 mm (determined by mask geometry during the deposition). Pad spacing for transverse measurements were preset by the sample thickness. Copper wires were attached to these gold-platted pads using silver-filled epoxy (H.sub.2OE, EPO-TEK, MA). Four-point probe DC-resistive measurements were performed using an HP multimeter (HP34401A). As a first approximation, the composite electrical resistivity was calculated from known specimen geometry. In these initial results, longitudinal and transverse resistivities diverged considerably, especially for EG-filled composites. Transverse resistivities were always higher than longitudinal ones. However longitudinal measurements, considering the electrical leads configuration, include both longitudinal, I.sub.l and transverse, I.sub.l components of the current path (FIG. 14). In order to separate these two components, the current distribution across the specimen was modeled based on the finite-element method (Femlab 3.1, Comsol AB). For each measured sample, we input actual specimen and electrical pads geometry, transverse resistivity, and longitudinal resistance to obtain the computed longitudinal resistivities that are reported in this paper.
XRD patterns of graphite, GO, and TEGO were recorded in a Rigaku MiniFlex diffractometer with Cu Ku radiation. Initial, final and step angles were 5, 30 and 0.02, respectively. The surface area of TEGO was measured by nitrogen adsorption at 77K using a Micromeritics FlowSorb apparatus with a mixture of N.sub.2 and He 30/70 by volume as the carrier gas. High-resolution XPS spectra were obtained using an Omicron ESCA Probe (Germany). Samples were de-gassed overnight within the XPS chamber (10-3 mbar) prior to analysis of the sample. Data were collected using 15 kV and 20 mA power at 10-9 mbar vacuum. The raw XPS data were analyzed to determine peak locations and areas in relation to specific binding energies that best fit the experimental data. The main C--C peak (C.sub.1s) at 284.6 eV was observed. An additional photoemission present at higher binding energy peaks at 286.1 eV represented --C--O-- or C--O--C bonding.
The solid-state magic angle spinning (MAS) 13C NMR spectrum of the graphite oxide was obtained using a Chemagnetics CMX-II 200 spectrometer with a carbon frequency of 50 MHz, a proton frequency of 200 MHz, and a zirconia rotor of 7.5 mm diameter spinning at 4000 Hz. To enable separation of the carbon peaks of the solid GO sample a so called, "Block pulse sequence" was used. This employs a decay pulse sequence with a 450 pulse angle of 2.25 ms, high-power proton decoupling (.about.50 kHz), and a 20 s delay between pulses. The spectrum was run at room temperature and 5120 scans were acquired with 4 K data points each. The chemical shifts were given in ppm from external reference of the hexamethylbenzene methyl peak at 17.4 ppm.
The surface area of TEGO samples prepared from a GO sample that was oxidized for 120 hours and heated for 30 seconds at different temperatures is shown in FIG. 6 (".cndot." denotes samples dried in vacuum oven for 12 hours at 60.degree. C., and ".circle-solid." represents samples equilibrated at ambient temperature and relative humidity prior to exfoliation).
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