Graphenic carbon particle dispersions and methods of making same.

(54) Title: DISPERSIONS OF GRAPHENIC CARBON PARTICLES AND METHODS TO MAKE THE SAME.

(54) Title: GRAPHENIC CARBON PARTIOLE DISPERSIONS AND METHODS OF MAKING SAME.

(57) Summary

The graphene carbon particle dispersions are produced using a polymeric dispersant. The polymeric dispersant includes an anchoring block comprising glycidyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, 2- (3,4-epoxycyclohexyl) (meth) acrylate, ethyl there glycidyl ether and mixtures thereof, reacting with a carboxylic acid comprising 3-hydroxy-2-naphthoic acid, para-nitrobenzoic acid, hexanoic acid, 2-ethylhexanoic acid, decanoic acid and / or undecanoic acid. The polymeric dispersant also includes at least one end block comprising at least one alkyl ester of (meth) acrylic acid.

(57) Abstract

Dispersions of graphenic carbon particles are produced using a polymeric dispersant. The polymeric disperse! includes an anchor block comprising glycidyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, 2- (3,4epoxycyclohexyl) ethyl (meth) acrylate, allyl glycidyl ether and mixtures thereof, reacted with a carboxylic acid comprising 3hydroxy-2 -naphthoic acid, para-nitrobenzoic acid, hexanoic acid, 2-ethyl hexanoic acid, decanoic acid and / or undecanoic acid. The polymeric dispersant also includes at least one tail block comprising at least one (meth) acrylic acid alkyl ester.

DISPERSIONS OF GRAPHENIC CARBON PARTICLES AND METHODS TO MAKE THE SAME

FIELD OF THE INVENTION

The present invention relates to dispersions of graphene carbon particles and methods for making such dispersions.

BACKGROUND OF THE INVENTION

Graphene carbon particles have many potential uses such as inks and coatings. However, graphene carbon particles have been found to be difficult to disperse in different media such as organic solvents and water. Ethylcellulose has been used as a dispersing aid in attempts to improve the dispersion of graphene carbon particles. However, there is a need for improved dispersions of graphene carbon particles in order to improve the properties of inks and coatings and other materials containing such particles. For example, electrical conductivity properties can be improved with improved dispersions of graphene carbon particles in different types of inks and coatings, such as clear coatings, colored coatings, primer coatings, printed electronics and static dissipation coatings, batteries, etc. capacitors, electrical traces, antennas, electrical heating coatings, and the like.

BRIEF DESCRIPTION OF THE INVENTION

One aspect of the invention provides a dispersion comprising a solvent, graphene carbon particles dispersed in the solvent, and a polymeric dispersant. The polymeric dispersant comprises a) an anchor block comprising glycidyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, ethyl 2- (3,4-epoxycyclohexyl) (meth) acrylate, allyl glycidyl ether and mixtures of the themselves, which react with a carboxylic acid comprising 3-hydroxy-2-naphthoic acid, para-nitrobenzoic acid, hexanoic acid, 2-ethylhexanoic acid, decanoic acid and / or undecanoic acid, and b) at least one end block comprising at least one (meth) acrylic acid alkyl ester.

Another aspect of the invention provides an electrically conductive coating produced from a dispersion comprising a solvent, graphene carbon particles dispersed in the solvent, and a polymeric dispersant. The polymeric dispersant comprises a) an anchor block comprising glycidyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, ethyl 2- (3,4-epoxycyclohexyl) (meth) acrylate, allyl glycidyl ether and mixtures of the themselves, which react with a carboxylic acid comprising 3-hydroxy-2-naphthoic acid, para-nitrobenzoic acid, hexanoic acid, 2-ethylhexanoic acid, decanoic acid and / or undecanoic acid, and b) at least one end block comprising at least one (meth) acrylic acid alkyl ester.

A further aspect of the invention provides a method for dispersing graphene carbon particles in a solvent which comprises mixing the graphene carbon particles in the solvent in the presence of a polymeric dispersant comprising a) an anchor block comprising (meth) acrylate of glycidyl, 3,4-epoxycyclohexylmethyl (meth) acrylate, ethyl 2- (3,4-epoxycyclohexyl) (meth) acrylate, allyl glycidyl ether and mixtures thereof, reacting with a carboxylic acid comprising 3-hydroxy-2-naphthoic acid, para-nitrobenzoic acid, hexanoic acid, 2-ethylhexanoic acid, decanoic acid and / or undecanoic acid, and b) at least one end block comprising at least one (meth) acrylic acid alkyl ester.

BRIEF DESCRIPTION OF THE DRAWINGS

Figures 1 and 2 are TEM images showing non-uniform and uniform dispersions of graphene carbon particles, respectively.

Figure 3 is a graph illustrating the electrical conductivity properties of coatings containing graphene carbon particles in accordance with embodiments of the invention.

DETAILED DESCRIPTION OF THE INVENTION

In accordance with embodiments of the present invention, the graphene carbon particles are dispersed in inks and coatings and other materials through the use of polymeric dispersants to provide desirable properties such as increased electrical conductivity. Although embodiments in which graphene carbon particles are dispersed within inks and coatings are primarily described herein, it should be understood that other types of materials having such dispersions are within the scope of the present invention, such as batteries, capacitors , electrical traces and the like.

As used herein, the term "dispersed" means that the graphene carbon particles are dispersed throughout a material without substantial agglomeration of the particles. The presence of agglomerations can be determined by standard methods such as visual analysis of TEM micrograph images. Figures 1 and 2 are examples of TEM images showing agglomerated and non-agglomerated graphene carbon particles, respectively, in a conventional automotive ground resin and a multi-block copolymer dispersant. Agglomerations can also be detected by means of standard particle size measurement techniques, as well as measurements of electrical conductivity or measurements of optical characteristics of materials containing the graphene carbon particles such as color properties, turbidity, degree of darkness, reflectance and transmission.

As used herein, the term electrically conductive, when referring to an ink or coating that contains graphene carbon particles, means that the ink or coating has an electrical conductivity of at least 0.001 S / m. For example, the coating can have a conductivity of at least 0.01 S / m, or at least 10 S / m. Generally, the conductivity can be from 100 to 100,000 S / m, or higher. In certain embodiments, the conductivity can be at least 1,000 S / m or at least 10,000 S / m. For example, the conductivity can be at least 20,000 S / m, or at least 30,000 S / m, or at least 40,000 S / m.

According to certain embodiments, the inks or coatings do not exhibit significant electrical conductivity absent from the addition of graphene carbon particles. For example, a cured polymeric resin used each may have conductivity that is not measurable, while the cured or dried polymeric resins of the present invention that include graphene carbon particles may exhibit conductivities as mentioned above.

In certain embodiments, the graphene carbon particles can be dispersed within a base material such as a resin to form film in amounts from 0.1 to 95 percent by weight based on the total solids of the material. For example, the graphene carbon particles may comprise 1 to 90 percent by weight, or 5 to 85 percent by weight of the material. In certain embodiments, the amount of graphene carbon particles contained in the materials can be relatively large, such as 40 or 50 percent by weight to 90 or 95 percent by weight. For example, the graphene carbon particles can comprise 60 to 85 percent by weight, or 70 to 80 percent by weight. In certain embodiments, the conductivity properties of the ink or coating can be significantly increased with relatively minor additions of graphene carbon particles, eg, less than 50 percent by weight, or less than 30 percent by weight. In certain embodiments, coatings or other materials have sufficiently high electrical conductivities at relatively low loads of graphene carbon particles. For example, the electrical conductivities mentioned above can be achieved at graphene carbon particle loads of less than 20 or 15 weight percent. In certain embodiments, the particulate charges can be less than 10 or 8 percent by weight, or less than 6 or 5 percent by weight. For example, for coatings that comprise polymers or film-forming resins that are themselves non-conductive, dispersion of 3 to 5 weight percent graphene carbon particles can provide an electrical conductivity of at least 0.1 S / m, p eg, or at least 10 S / m.

The compositions can comprise any of a variety of thermoplastic and / or thermosetting compositions known in the art. For example, coating compositions may comprise film-forming resins selected from epoxy resins, acrylic polymers, polyester polymers, polyurethane polymers, polyamide polymers, polyether polymers, bisphenol A-based epoxy polymers, polysiloxane polymers, styrenes, ethylenes, butylenes, copolymers thereof, and mixtures thereof. Generally, these polymers should be any such polymer made by any method known to those of skill in the art. Such polymers may be solvent based, water soluble or water dispersible, emulsifiable, or of limited water solubility. In addition, the polymers may be provided in sol-gel systems, they may be provided in encapsulated active substance and sheath (coreshell) polymer systems, or they may be provided in powder form. In certain embodiments, the polymers are dispersions in a continuous phase comprising water and / or organic solvent, for example emulsion polymers or non-aqueous dispersions.

In addition to resin and graphene carbon particle components, coatings or other materials in accordance with certain embodiments of the present invention may include additional components conventionally added to coating or ink compositions, such as cross-linkers, pigments, inks, aids, flux, defoamers, dispersants, solvents, UV absorbers, catalysts and surface active agents.

Thermoset or curable coating compositions generally comprise polymers or film-forming resins having functional groups that are reactive with either themselves or a cross-linking agent. Functional groups on the film-forming resin can be selected from any of a variety of reactive functional groups including, for example, carboxylic acid groups, amine groups, epoxide groups, hydroxyl groups, thiol groups, carbamate groups, amide groups, urea groups. , isocyanate groups (including blocked isocyanate groups and tris-alkylcarbamoyltriazine) mercaptan groups, styrenic groups, anhydride groups, acetoacetate acrylates, uretidione and combinations thereof.

Thermoset coating compositions generally comprise a crosslinking agent that can be selected from, for example, aminoplasts, polyisocyanates, including blocked isocyanates, polyepoxides, beta-hydroxyalkylamides, polyacids, anhydrides, organometallic acid functional materials, polyamines, polyamides, and mixtures of any of the previous. Suitable polyisocyanates include multifunctional isocyanates. Examples of multifunctional polyisocyanates include aliphatic diisocyanates such as hexamethylene diisocyanate and isophorone diisocyanate, and aromatic diisocyanates such as toluene diisocyanate and 4,4'-diphenylmethane diisocyanate. Polyisocyanates can be blocked or unblocked. Examples of other suitable polyisocyanates include isocyanurate trimers, allophanates, and uretdiones of diisocyanates. Examples of commercially available polyisocyanates include DESMODUR N3390, which is sold by Bayer Corporation, and TOLONATE HDT90, which is sold by Rhodia Inc. Suitable aminoplasts include amine and / or amide condensates with aldehyde. For example, melamine-formaldehyde condensate is a suitable aminoplast. Suitable aminoplasts are well known in the art. A suitable aminoplast is disclosed, for example, in US Patent No. 6,316,119 at column 5, lines 45-55, incorporated by reference herein. In certain embodiments, the resin can be self-crosslinking.

Self crosslinking means that the resin contains functional groups that are capable of reacting with themselves, such as alkoxysilane groups, or that the reaction product contains functional groups that are reactive, for example hydroxyl groups and blocked isocyanate groups.

The dry film thickness of the cured coatings can generally range from less than 0.5 microns to 100 microns or more, eg, 1 to 50 microns. As a particular example, the cured coating thickness can range from 1 to 15 microns. However, significantly greater coating thicknesses, and significantly greater material dimensions for non-coating materials, are within the scope of the invention.

As used herein, the term "graphene carbon particles" means carbon particles having structures that comprise one or more layers of flat sheets one atom thick of sp-bonding carbon atoms.² which are densely packed in a honeycomb-shaped 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 graphene carbon particles can be substantially flat, however, at least a portion of the flat sheets can be substantially curved, wavy, wrinkled, or twisted.

The graphene carbon particles to be dispersed in the compositions of the present invention can be made by means of thermal processes. In accordance with embodiments of the invention, the thermally produced graphene carbon particles are made from carbon-containing precursor materials that are heated to high temperatures in a thermal zone such as a plasma. As more fully described below, carbon-containing precursor materials are heated to a temperature high enough, eg, above 3500 ° C, to produce graphene carbon particles having characteristics such as those described. previously. The carbon-containing precursor, such as a hydrocarbon provided in liquid or liquid form, is heated in the thermal zone to produce the graphene carbon particles in or downstream of the thermal zone. For example, thermally produced graphene carbon particles can be made by the systems and methods disclosed in US Patent Nos. 8,486,363 and 8,486,364.

In certain embodiments, the thermally produced graphene carbon particles can be made using the apparatus and method described in US Patent No. 8,486,363 in paragraphs [0022] to [0048] in which (i) one or more hydrocarbon precursor materials capable of forming 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 form the graphene carbon particles . In other embodiments, the thermally produced graphene carbon particles can be made using the apparatus and method described in US Patent No. 8,486,364 in paragraphs [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 greater) is introduced into a thermal zone (such as a plasma), and (ii) the methane precursor is heated in the thermal zone to form the graphene carbon particles. Such methods can produce graphene carbon particles that have at least some, in some cases all, of the characteristics described above.

During the production of the graphene carbon particles by the thermal production methods described above, the carbon-containing precursor is provided as a feedstock that can be contacted with an inert carrier gas. The carbon-containing precursor material can be heated in a thermal zone, for example, by means of a plasma system. In certain embodiments, the precursor material is heated to a temperature of at least 3500 ° C, for example, from a temperature of more than 3500 ° C or 4000 ° C to 10,000 ° C or 20,000 ° C. Although the thermal zone can be generated by means of a plasma system, it should be understood that any other suitable heating system can be used to create the thermal zone, such as different types of furnaces including electrically heated tube furnaces and the like.

The gaseous stream may contact one or more quench streams that are injected into the plasma chamber through at least one quench stream injection port. The quench stream can cool the gas stream to facilitate the formation or control of the particle size or morphology of the graphene carbon particles. In certain embodiments of the invention, after the gaseous product stream is contacted with the quench streams, the ultrafine particles can pass through a convergence member. After the graphene carbon particles leave the plasma system, they can be collected. Any suitable means can be used to separate the graphene carbon particles from the gas flow, such as, for example, a bag filter, dust extractor (cyclone) separator or position on a substrate.

In certain embodiments, the graphene carbon particles can be obtained from commercial sources, eg, Angstron, XG Sciences, and other commercial sources. In such embodiments, commercially available graphene carbon particles may comprise exfoliated graphite and have different characteristics compared to thermally produced graphene carbon particles, such as different size distributions, thicknesses, aspect ratios, structural morphology, oxygen content. , and chemical functionality in the basal planes / edges.

In certain embodiments, different types of graphene carbon particles can be dispersed in the composition. For example, when the thermally produced graphene carbon particles are combined with commercially available graphene carbon particles according to the embodiments of the invention, a bi-modal distribution, tri-modal distribution, etc. can be achieved. graphene carbon particle characteristics. The graphene carbon particles contained in the compositions can have multi-modal particle size distributions, aspect ratio distributions, structural morphology, differences in edge functionality, oxygen content, and the like.

In one embodiment of the present invention in which both the thermally produced graphene carbon particles and the commercially available graphene carbon particles, e.g., from spolied graphite, are added to a coating composition to produce a size distribution of bi-modal graphene particles, the relative amounts of the different types of graphene carbon particles are controlled to produce desired conductivity properties of the coatings. For example, thermally produced graphene particles can comprise 1 to 50 percent by weight, and commercially available graphene carbon particles can comprise 50 to 99 percent by weight, based on the total weight of the graphene carbon particles. . In certain embodiments, the thermally produced graphene carbon particles may comprise 2 to 20 percent by weight, or 5 to 10 or 12 percent by weight.

In certain embodiments, the coating compositions or other materials produced with the present dispersions are substantially free of certain components such as polyalkyleneimines, graphite, or other components. For example, the term "substantially free of polyalgyleneimines" means that the polyalkyleneimines are not added on purpose, or are present as impurities or in trace amounts, eg, less than 1 percent by weight or less than 0.1 percent by weight. . The term "substantially free of graphite" means that the graphite is not added on purpose, or is present as an impurity or in trace amounts, eg, less than 1 percent by weight or less than 0.1 percent by weight. In certain embodiments, the graphite may be present in lesser amounts in the materials, eg, less than 5 percent by weight or less than 1 percent by weight of the material. If graphite is present, it is generally in an amount less than the graphene carbon particles, e.g., less than 30 percent by weight based on the combined weight of the graphite and the graphenic carbon particles, e.g. , less than 20 or 10 percent by weight.

In certain embodiments, the compositions of the present invention are prepared from a dispersion comprising: (a) graphene carbon particles such as any of those described above; (b) a carrier that can be selected from water, at least one organic solvent, or combinations of water and at least one organic solvent; (c) a polymeric dispersant, such as the y, copolymer generally described below;

optionally, (d) at least one resin as described above or other additives.

Certain compositions of the present invention comprise a polymeric dispersant. In certain embodiments, such a polymeric dispersant comprises a tri-block copolymer comprising: (i) a first segment comprising groups related to the graphene carbon, such as hydrophobic aromatic groups; (ii) a second segment comprising polar groups, such as hydroxyl groups, amine groups, ether groups, and / or acid groups; and (iii) a third segment that is different from the first segment and the second segment, such as a segment that is substantially non-polar, that is, substantially free of polar groups. As used herein, the term "substantially free" as used in reference to the absence of groups in a polymer segment, means that no more than 5% by weight of the monomer used to form the third segment comprises polar groups.

Suitable polymeric dispersants include acrylic copolymers produced from radical atom transfer polymerization. In certain embodiments, such copolymers have a weight average molecular weight of 1,000 to 20,000.

In certain embodiments, the polymeric pigment dispersant has a polymer chain structure represented by the following general formula (I),

Φ^-(G) _p- (W) _what-(AND) _ST (I) wherein G is a residue of at least one radically polymerizable ethylenically unsaturated monomer; W and Y are residues of at least one radically polymerizable ethylenically unsaturated monomer with W and Y being different from each other; Y is optional; * Is a hydrophobic residue of or derived from an initiator and is free from the radically transferred group; T is or is derived from the radically transferred group of the initiator; p, q and s represent average numbers of residues that occur in a block of residues; each of p, q and s is selected individually such that the polymeric dispersant has a number average molecular weight of at least 250.

The polymeric dispersant can be generally described as having a head and tail structure, that is, as having a polymeric head portion and a polymeric tail portion. The polymeric glue portion may have a hydrophilic portion and a hydrophobic portion, particularly at the terminus thereof. While not intended to be bound by any theory, it is believed that the polymeric head portion of the polymeric dispersant may be associated with graphene carbon particles, while the polymeric tail portion aids in the dispersion of the graphene carbon particles and may associate with other components of an ink or coating composition. As used herein, the terms hydrophobic and hydrophilic are related to each other.

In certain embodiments, the polymeric dispersant is prepared by Atom Transfer Radical Polymerization (ATRP). The ATRP process can generally be described as comprising: polymerizing one or more radically polymerizable monomers in the presence of an initiator system; form a polymer; and isolating the polymer formed. In certain embodiments, the initiation system comprises: a monomeric initiator having a single radically transferable atom or group; a transition metal compound, that is, a catalyst, that participates in a reversible redox cycle with the initiator; and a binder, which coordinates with the transition metal compound. The ATRP process is described in greater detail in International Patent Publication No. WO 98/40415 and United States Patent Nos. 5,807,937, 5,763,548 and 5,789,487.

Catalysts that can be used in the ATRP preparation of the polymeric dispersant include any transition metal compound that can participate in a redox cycle with the initiator and the growing polymer chain. It may be preferred that the transition metal compound does not form direct carbon-metal bonds with the polymer chain. The transition metal catalysts useful in the present invention can be represented by the following general formula (II),

M^{n +}X_n (II) where M is the transition metal; n is the formal charge on the transition metal that has a value from 0 to 7; and X is a covalently linked counterion or component. Examples of the transition metal M include, but are not limited to, Cu, Fe, Au, Ag, Hg, Pd, Pt, Co, Mn, Ru, Mo, Nb, and Zn. Examples of X include, but are not limited to, halide, hydroxy, oxygen, Ci-C₆-alkoxy, cyano, cyanate, thiocyanate and azido. In a specific example, the transition metal is Cu (I) and X is halide, eg, chloride. Consequently, a specific class of transition metal catalysts are the copper halides, eg, Cu (I) Cl. In certain embodiments, the transition metal catalyst may contain a small amount, eg, 1 mole percent, of a redox conjugate, eg, Cu (II) Cl₂ when using Cu (I) Cl. Additional catalysts useful in the preparation of the polymeric dispersant are described in US Patent Document

US No. 5,807,937 at column 18, lines 29 to 56. Redox conjugates are described in greater detail in US Patent No. 5,807,937 at column 11, line 1 to column 13, line 38 .

Binders that can be used in the ATRP preparation of the polymeric dispersant include, but are not limited to, compounds having one or more nitrogen, oxygen, phosphorous and / or sulfur atoms, which can coordinate with the catalyst compound of transition metal, for example, via sigma and / or pi bonds. Useful classes of binders include, but are not limited to, unsubstituted and substituted pyridines and bipyridines; porphyrins; cryptands; crown ethers; for example, 18 crown-β; polyamines, for example ethylenediamine; glycols, for example alkylene glycols, such as ethylene glycol; carbon monoxide; and coordination monomers, for example, styrene, acrylonitrile, and hydroxyalkyl (meth) acrylates. As used herein, the term (meth) acrylate and like terms refer to acrylates, methacrylates, and mixtures of acrylates and methacrylates. A specific class of binders are the substituted bipyridines, eg, 4,4'-dialkyl-bipyridyls. Additional binders that can be used in the preparation of the polymeric dispersant are described in US Patent No. 5,807,937 at column 18, line 57 to column 21, line 43.

Classes of monomeric initiators that can be used in the ATRP preparation of the polymeric dispersant include, but are not limited to, aliphatic compounds, cycloaliphatic compounds, aromatic compounds, polycyclic aromatic compounds, heterocyclic compounds, sulfonyl compounds, sulfenyl compounds, esters of carboxylic acids, nitrites, ketones, phosphonates, and mixtures thereof, each with a radically transferable group, and preferably a single radically transferable group. The radically transferable group of the monomeric initiator can be selected from, for example, cyano, cyanate, thiocyanate, azido and halide groups. The monomeric initiator can also be substituted with functional groups, for example oxiranyl groups, such as glycidyl groups. Additional useful initiators are described in US Patent No. 5,807,937 in column 17, line 4 to column 18, line 28.

In certain embodiments, the monomeric initiator is selected from l-halo-2,3-epoxypropane, ptoluenesulfonyl halide, p-toluenesulfenyl halide, C₆C2o^_alpha-halo-C acid alkyl₂-C₆-carboxylic, halomethylbenzene, (1-haloethyl) benzene, halomethylnaphthalene, halomethylanthracene and mixtures thereof. Ester examples

C₂-C6-alkyl alpha-halo-C acids₂~ C6-carboxylics include, hexyl alpha-bromopropionate, 2-ethylhexyl alpha-bromopropionate, 2-ethylhexyl alpha-bromohexionate, and icosanyl alpha-bromopropionate. As used herein, the term "monomeric initiator" is understood to be distinguishable from polymeric initiators, such as polyethers, polyurethanes, polyesters, and acrylic polymers that have radically transferrable groups.

In the preparation of ATRP, the polymeric dispersant and the relative amounts and proportions of the monomeric initiator, the transition metal compound, and the binder can be those for which ATRP is most effectively carried out. The amount of initiator used can vary widely and is generally present in the reaction medium in a concentration of 10 ~⁴ mol / liter (M) to 3 M, for example, from 10³ M to 10¹ M. Since the molecular weight of the polymeric dispersant can be directly related to the relative concentrations of the initiator and the monomer (s), the molar ratio of initiator to monomer is an important factor in polymer preparation. The molar ratio of initiator to monomer is generally within the range of 10⁴: the 0.5: 1, for example, 10³: the 5 x 10 '²: l.

In the preparation of the polymeric dispersant by means of ATRP methods, the molar ratio of the transition metal compound to the initiator is generally in the range of 10 ~⁴: 10: 1, for example, 0.1: 1 to 5: 1. The molar ratio of the binder to the transition metal compound is generally within the range of 0.1: 1 to 100: 1, for example 0.2: 1 to 10: 1.

The polymeric dispersant can be prepared in the absence of solvent, that is, by means of a bulk polymerization process. Often times, the polymeric dispersant is prepared in the presence of a solvent, generally water and / or an organic solvent. Classes of useful organic solvents include, but are not limited to, carboxylic acid esters, esters, cyclic esters, C5-C10 alkanes, C cycloalkanes₅-C₈, aromatic hydrocarbon solvents, halogenated hydrocarbon solvents , amides, nitrites, sulfoxides, sulfones, and mixtures thereof. Supercritical solvents, such as CO, can also be used.₂, C1-C4 alkanes and fluorocarbons. One class of solvents is that of aromatic hydrocarbon solvents, such as xylene, toluene, and mixed aromatic solvents such as those commercially available from Exxon Chemical America under the trade name SOLVESSO. Additional solvents are described in greater detail in US Patent No. 5,807,937, at column 21, line 44 to column 22, line 54.

The ATRP preparation of the polymeric dispersant is generally conducted at a reaction temperature within the range of 25 ° C to 140 ° C, example, from 50 ° C to 100 ° C, and at a pressure within the range of 1100 atmospheres, generally at ambient pressure.

The ATRP transition metal catalyst and its associated binder are generally separated or removed from the polymeric dispersant prior to use in the polymeric dispersants of the present invention. Removal of the ATRP catalyst can be accomplished using known methods, including, for example, adding a catalyst binding agent to the mixture of polymeric dispersant, solvent and catalyst, followed by filtration. Examples of suitable catalyst binding agents include, for example, alumina, silica, clay, or a combination thereof. A mixture of polymeric dispersant, solvent and ATRP catalyst can be passed through a bed of catalyst binding agent. Alternatively, the ATRP catalyst can be oxidized on-site, the oxidized residue of the catalyst being retained in the polymeric dispersant.

With reference to general formula (I), G may be a residue of at least one radically polymerizable ethylenically unsaturated monomer, such as a monomer selected from a carboxylic acid reacted oxirane functional monomer which may be an aromatic carboxylic acid or polycyclic aromatic carboxylic acid.

The oxirane functional monomer or its residue which is reacted with a carboxylic acid can be selected from, for example, glycidyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, 2- (3,4-epoxycyclohexyl) (meth) ethyl acrylate, allyl glycidyl ether, and mixtures thereof. Examples of carboxylic acids that can be reacted with the functional oxirane monomer or its residue include, but are not limited to, naphthoic acid, hydroxy naphthoic acids, para-nitrobenzoic acid, and mixtures thereof.

With continued reference to general formula (I), in certain embodiments, each of W and Y can independently be residues of, including, but not limited to, methyl (meth) acrylate, ethyl (meth) acrylate, (meth ) propyl acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, iso-butyl (meth) acrylate, tert-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meth ) lauryl acrylate, isobornyl (meth) acrylate, cyclohexyl (meth) acrylate, 3,3,5-trimethylcyclohexyl (meth) acrylate, isocane (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, butyl (meth) acrylate, mono (meth) methoxy poly (ethylene glycol) acrylate, mono (meth) acrylate poly (ethylene glycol), mono (meth) acrylate methoxy poly (propylene glycol), mono (meth) acrylate poly (propylene glycol), mono (meth) acrylate methoxy copoly (ethylene glycol / propylene glycol), copoly (ethylene glycol / propylene glycol) mono (meth) acrylate.

In general formula (I), in certain embodiments, each of W and Y can independently be residues of monomers having more than one (meth) acryloyl group, such as (meth) acrylic anhydride, diethylene glycol bis (meth) acrylate , 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 4,4'-isopropylidene diphenol bis (meth) acrylate (Bisphenol A di (meth) acrylate), 4,4'isopropylidene diphenol bis (meth) acrylate alkoxylated, trimethylolpropane tris (meth) acrylate, alkoxylated trimethylolpropane tris (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, and copoly (ethylene glycol / propylene glycol) di (meth) acrylate.

The numerals p, q and s represent the average total number of residues G, W and Y, respectively, that occur for what o segment of residues G (blog G or segment G), residues W (block W or segment W) and residuals Y (block Y or segment Y), respectively. When they contain more than one type of monomer residue species, each of the W and Y blocks can have at least one random block (eg, di-block and tri-block), alternating, and gradient architectures. Gradient architecture refers to a sequence of different monomer residues that gradually change in a systematic and predictable manner along the polymer backbone. For illustration purposes, a W block containing 6 residues of butyl methacrylate (BMA, Butyl Methacrylate) and 6 residues 5 of hydroxypropyl methacrylate (HPMA, Hydroxy Propyl

Methacrylate), for which q is 12, can have di-block, tetra-block, alternating, and gradient architectures as described in US Patent No. 6,642,301, column 10, lines 5-25. In certain embodiments, the G block can include about 5-15 glycidyl (meth) acrylate residues reacted with an aromatic carboxylic acid (such as 3-hydroxy-2-naphthoic acid), the W block can be a random block of about 20-30 BMA and HPMA residues and the Y block can be a uniform block of about 5-15 butyl acrylate residues (BA, Butyl Acrylate).

The order in which the monomer residues occur along the polymer backbone of the polymeric dispersant is generally determined by the order in which the corresponding monomers are fed into the vessel in which the controlled radical polymerization is conducted. . For example, monomers that are incorporated as residues in the G block of the polymeric dispersant are generally fed into the reaction vessel before those monomers that are incorporated as residues in the W block, followed by the residues of the Y block.

During the formation of the W and Y blocks, if more than one monomer is fed into the reaction vessel at the same time, the relative reactivities of the monomers generally determine the order in which they are incorporated into the living polymer chain. Gradient sequences of monomer residues with the W and Y blocks can be prepared by means of controlled radical polymerization, and in particular by means of ATRP methods by (a) varying the ratio of monomers fed to the reaction medium during the course of polymerization, (b) using a monomer feed containing monomers having different polymerization rates, or (c) a combination of (a) and (b). Copolymers containing gradient architecture are described in greater detail in US Patent No. 5,807,937, at column 29, line 29 to column 31, line 35.

In certain embodiments, each of the subscripts q and s has a value of at least 1, such as at least 5 for general formula (I). Also, the subscript sa often has a value of less than 300, such as less than 100, or less than 50 (for example 20 or less) for the general formula (I). The values ​​of the subscripts q and s can range from any combination of these values, inclusive of the recited values, for example, is e can be a number from 1 to 100. The subscript d can have a value of at least 1, such as at least 5. The subscript t also often has a value of less than 300, such as less than 100 or less than 50 (eg, 20 or less ). The value of the subscript p can range from any combination of these values, inclusive of the recited values, for example, p can be a number up to 50. The polymeric dispersant often has a number average molecular weight (Mn) of 250 to 40,000, for example 1,000 to 30,000 or 2,000 to 20,000, as determined by gel permeation chromatography using standard polystyrene.

The symbol Φ of the general formula (I) is, or is derived from, the residue of the initiator used in the preparation of the polymeric dispersant by means of controlled radical polymerization, and is free from the radically transferable group of the initiator. For example, when the polymeric dispersant is initiated in the presence of toluenesulfonyl chloride, the symbol Φ, more specifically Φ- is the residue,

<img file="MX2016007451A_D0001.tif" />

o = s = o.

The symbol Φ may also represent a derivative of the initiator residue.

In general formula (I), T is or is derived from the radically transferable group of the initiator of ATRP. The radically transferable group residue can be (a) left in the polymeric dispersant, (b) removed, or (c) chemically converted to another half. The radically transferable group can be removed by substitution with a nucleophilic compound, for example, an alkali metal alkoxylate. When the residue of the radically transferable group is, for example, a cyano (—CN) group, this can be converted to an amide group or carboxylic acid group by methods known in the art.

The polymeric dispersant is generally present in the graphene carbon particle dispersion described above in an amount of at least 0.1 weight percent, such as at least 0.5 weight percent, or, in some cases, at least 1 percent by weight. weight, based on the total weight of the dispersion of graphene carbon particles. The polymeric dispersant may generally be present in the dispersion of graphene carbon particles in an amount of less than 75 percent by weight, or less than 50 percent by weight, based on the total weight of the dispersion of graphene carbon particles. . In certain embodiments, the polymeric dispersant may be present in the dispersion of graphene carbon particles in an amount of less than 30 percent by weight, or less than 15 percent by weight, based on the total weight of the dispersion of particles. graphene carbon.

The dispersion of graphene carbon particles often also comprises at least water and / or at least one organic solvent. Classes of organic solvents that may be present include, but are not limited to, xylene, toluene, alcohols, e.g., methanol, ethanol, n-propanol, iso-propanol, n-butanol, sec-butyl alcohol, tert-butyl alcohol, alcohol iso-butyl, furfuryl alcohol, and tetrahydrofurfuryl alcohol; ketones or keto alcohols, for example acetone, methyl ethyl ketone, and diacetone alcohol; ethers, for example, dimethyl ether and methyl ethyl ether; cyclic ethers, for example tetrahydrofuran and dioxane; esters, for example, ethyl acetate, ethyl lactate, ethyl carbonate, and propylene carbonate; polyhydric alcohols, for example ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, tetraethylene glycol, polyethylene glycol, glycerol, 2-methyl-2,4-pentanediol and 1,2,6-hexatriol; hydroxide functional ethers of alkylene glycols, for example butyl 2-hydroxyethyl ether, hexyl 2-hydroxyethyl ether, methyl 2-hydroxypropyl ether and phenyl 2-hydroxypropyl ether; nitrogen containing cyclic compounds, for example, pyrrolidone, n-methyl-2-pyrrolidone and 1,3-dimethyl-2-imidazolidinone; and sulfur containing compounds such as thioglycol, dimethylsulfoxide, and tetramethylene sulfone. When the solvent comprises water, it can be used alone or in combination with organic solvents such as propylene glycol monomethyl ether, ethanol, and the like.

The graphene carbon particle dispersion can be prepared by means of methods that are known to those skilled in the art. Such known methods generally involve the use of high energy consuming mixing or grinding media, such as ball mills or media mills (eg, sand mills).

The graphene carbon particles can be mixed with resins to form film and other components in the compositions. For example, for two-part coating systems, the graphene carbon particles can be dispersed in part A and / or part B. In certain embodiments, the graphene carbon particles are dispersed in part A by means of different mixing techniques. such as sonication, high speed mixing, grinding media, and the like. In certain embodiments, the graphene carbon particles can be mixed into coating compositions using high energy and / or high shear techniques such as sonication, 3-roll milling, ball milling, attritor milling, rotor mixers. / stator, and the like.

The following examples are intended to illustrate different aspects of the invention, and are not intended to limit the scope of the invention.

Example 1

Compositions A, B, C and D listed in Table 1 were dispersed by adding 70 g of each in 8 oz glass jars with 220 g of 1.0-1.25 mm SEPR Ermil grinding media. The samples in the flasks were shaken for 4 hours using a Lau disperser or diffuser (Model DAS 200, Lau, GmbH). The grinding media was then filtered from the dispersions. Compositions E, F, and G listed in Table 1 were dispersed 12.5 percent by weight based on total solids by sonication for 2 hours in a bath sonicator in (E) n-methyl-2-pyrrolidone, (F ) propylene glycol methyl ether (Dowanol PM Acetate, Dow Chemical), and (G) n, n-dimethylacetamide.

Table 1

Solvent-containing dispersions

<td rowspan="2">Ingredients</td><td colspan="7">Samples (% by weight)</td>

<td>TO</td><td>B</td><td>C</td><td>D</td><td>AND</td><td>F</td><td>G</td>

<td>Acrylic Grinding Vehicle</td><td> 34.32</td><td> 34.32</td><td></td><td></td><td></td><td></td><td></td>

<td>Polyester resin solution</td><td> 15.43</td><td> 15.43</td><td></td><td></td><td></td><td></td><td></td>

<td>Polyethylene cutting</td><td> 0.48</td><td> 0.48</td><td></td><td></td><td></td><td></td><td></td>

<td rowspan="2">Ingredients</td><td colspan="7">Samples (% by weight)</td>

<td>TO</td><td>B</td><td>C</td><td>D</td><td>AND</td><td>F</td><td>G</td>

<td>Acrylic Grinding Vehicle</td><td> 34.32</td><td> 34.32</td><td></td><td></td><td></td><td></td><td></td>

<td>Polyester resin solution</td><td> 15.43</td><td> 15.43</td><td></td><td></td><td></td><td></td><td></td>

<td>Polyethylene cutting</td><td> 0.48</td><td> 0.48</td><td></td><td></td><td></td><td></td><td></td>

<td>N-butyl acetate</td><td> 36.70</td><td> 36.70</td><td> 48.72</td><td> 62.21</td><td></td><td></td><td></td>

<td>Diisobutyl ketone</td><td> 7.53</td><td> 7.53</td><td></td><td></td><td></td><td></td><td></td>

<td>n-methyl-2- pyrrolidone</td><td></td><td></td><td></td><td></td><td> 87.5</td><td></td><td></td>

<td>Propylene Glycol Methyl Ether</td><td></td><td></td><td></td><td></td><td></td><td> 87.5</td><td></td>

<td>n, n- dimethylacetamide</td><td></td><td></td><td></td><td></td><td></td><td></td><td> 87.5</td>

<td>Solvent-containing block copolymer dispersant¹</td><td></td><td></td><td> 42.73</td><td> 31.49</td><td></td><td></td><td></td>

<td>xGnP C-300²</td><td> 5.56</td><td></td><td> 8.55</td><td></td><td></td><td></td><td></td>

<td>Thermally produced graphene carbon³</td><td></td><td> 5.56</td><td></td><td> 6.30</td><td> 12.5</td><td> 12.5</td><td> 12.5</td>

43% by weight of n-butyl acetate and 57% by weight of block copolymer as disclosed in US 2008/0188610 ² graphene carbon particles looted from XG Sciences ³ Thermally produced graphene carbon according to the method disclosed in US Patent No. 8,486,364 having a measured BET surface area of ​​280 µm²/ g

Example 2

The dispersed formulations of Example 1 (Samples 1A, IB, 1C, ID, 1E, 1F, and 1G) were added to a commercial solvent-containing black basecoat available from PPG Industries, Inc., at a level such that each formulation of Basecoat contained 2.36% graphene carbon particles on a total solids basis, resulting in samples 2A, 2B, 2C, 2D, 2E, 2F, and 2G, respectively. In each paint formulation, the graphene carbon replaced the same weight of black pigment that is normally contained in this solvent-containing black basecoat. Samples 2E, 2F, and 2G were sandy, showing the poor dispersion that results from sonication of the graphene carbon particles in solvents.

Example 3

Samples 2A, 2B, 2C, and 2D from Example 2 were reduced with n-butyl acetate to spray viscosity, and then sprayed onto 4 x 12 in. (10.16 x 30.48 cm) steel panels with electrodeposition coating (e -coat). These panels received a standard ambient flash and were then coated with a commercial carbamate clear coat available from PPG Industries, Inc. and oven cured to produce Samples 3A, 3B, 3C and 3D.

To quantify the adequacy of the scattering of the graphene carbon particles in Samples 3A, 3B, 3C and 3D, the color of each panel was measured using a BYKmac multi-angle spectrophotometer (BYK-Gardner) and the degree of darkness of the Black was calculated using the 110 ° angle color data. The degree of darkness (Jetness) was calculated using the equation Jetness = [logio (X_n/ X) + log₁₀(AND_n/ Y) - logi₀(Z_n/ Z)] (Equation 12 of K.

Lippok-Lohmer, Praxisnahe Scharzmessungen, Farbe + Lack, 92 (1986) 1024-1029). If the graphene carbon particles are well dispersed in the paint film, then the resulting light scattering will be reduced and this results in a higher degree of blackness value.

The resulting test data is shown in Table

2. For each type of graphene carbon particle, the dispersion of the particles was improved by using the tri-block copolymer dispersant, as shown by an increase in the degree of darkness. The paints of the 20 sonicated dispersions (Examples 2E, 2F and 2G) were not pulverized, but would have necessarily shown extremely poor (low) darkness, due to the agglomeration state of the graphene carbon particles in these paints. The use of the 25 tri-block copolymer dispersant results in significant improvement in the dispersion of graphene carbon particles compared to conventional solvent sonication methods and conventional ground resin technology.

Table 2 Color measurements

<td>Sample Panel</td><td>L * 110 °</td><td>a * 110 °</td><td>b * 110 °</td><td>Grade of Darkness</td>

<td>3A</td><td> 6.03</td><td> 0.07</td><td> 0.15</td><td> 217</td>

<td>3B</td><td> 1.89</td><td> 0.02</td><td> -0.11</td><td> 269</td>

<td>3C</td><td> 5.32</td><td> 0.14</td><td> 0.32</td><td> 221</td>

<td>3D</td><td> 1.63</td><td> -0.04</td><td> -0.26</td><td> 279</td>

Example 4

The compositions listed in Table 3 were dispersed by adding 70 g of each in 8 oz glass jars with 220 g of 1.0-1.25 mm SEPR Ermil grinding media. The samples in the flasks were shaken for 4 hours using a Lau diffuser (Model DAS 200, Lau, GmbH). The grinding media was then filtered from the dispersions. Samples 4J, 4K and 4L were made by mixing, respectively, Samples 4A and 4E, Samples 4B and 4G, and Samples 4C and 41, to form compositions containing two types of graphene carbon particles where 92 wt% total graphene carbon consisted of xGnP

M-25 from XG Sciences and 8% by weight of the total graphene carbon was produced according to the method disclosed in US Patent No. 8,486,364 which has a measured BET surface area of ​​280 µm.²/ g.

Table 3

Dispersions

<td rowspan="2">Ingredients</td><td colspan="9">% in weigh</td>

<td>TO</td><td>B</td><td>C</td><td>D</td><td>AND</td><td>F</td><td>G</td><td>H</td><td>I</td>

<td>Ethylcellulose</td><td> 1.67</td><td></td><td></td><td> 1.67</td><td> 1.67</td><td></td><td></td><td></td><td></td>

<td>Solvent-containing block copolymer dispersant¹</td><td></td><td> 2.92</td><td></td><td></td><td></td><td> 2.92</td><td> 2.92</td><td></td><td></td>

<td>Block copolymer dispersant containing water</td><td></td><td></td><td> 1.71</td><td></td><td></td><td></td><td></td><td> 1.71</td><td> 1.71</td>

<td>Nbutyl acetate</td><td></td><td></td><td></td><td></td><td></td><td> 87.08</td><td></td><td></td><td></td>

<td>Ethanol</td><td></td><td></td><td></td><td> 88.33</td><td></td><td></td><td></td><td></td><td></td>

<td>n-methyl-2-pyrrolidone</td><td> 88.33</td><td> 87.08</td><td></td><td></td><td> 88.33</td><td></td><td> 87.08</td><td></td><td></td>

<td>Deionized water</td><td></td><td></td><td> 44.15</td><td></td><td></td><td></td><td></td><td> 88.29</td><td> 44.15</td>

<td>Propylene Glycol Monomethyl Ether²</td><td></td><td></td><td> 44.15</td><td></td><td></td><td></td><td></td><td></td><td> 44.15</td>

<td>xGnP M-25³</td><td> 10.00</td><td> 10.00</td><td> 10.00</td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>Thermally produced graphene carbon⁴</td><td></td><td></td><td></td><td> 10.00</td><td> 10.00</td><td> 10.00</td><td> 10.00</td><td> 10.00</td><td> 10.00</td>

solvent-containing block copolymer dispersant as disclosed in US Patent No. 8,129,466 ² propylene glycol monomethyl ether (Dowanol PM, Dow Chemical Co) ³ xGnP M-25 (XG Sciences) ⁴ thermally produced graphene carbon particles according to the method disclosed in US Patent No. 8,486,364 having a measured BET surface area of ​​280 μm²/ g

The water-containing block copolymer dispersant listed in Table 3 was made from a mixture of the following ingredients in weight ratios listed in Table 4.

Table 4

<td>Load 1</td><td></td>

<td>2,2'-Bipyridyl</td><td> 2.7</td>

<td>Copper powder (0)</td><td> 1.0</td>

<td>Para-Toluenesulfonyl Chloride</td><td> 85.4</td>

<td>Aromatic 100</td><td> 459.0</td>

<td></td><td> 0.0</td>

<td>Load 2</td><td></td>

<td>Glycidyl methacrylate</td><td> 576.0</td>

<td></td><td></td>

<td>Load 3</td><td></td>

<td>Methoxy polyethylene glycol methacrylate 350</td><td> 2499.0</td>

<td>Aromatic 100</td><td> 300.0</td>

<td></td><td></td>

<td>Load 4</td><td></td>

<td>acetic acid</td><td> 5.0</td>

<td>ion exchange resin (Amberlite IRC 7480)</td><td> 120.0</td>

<td></td><td></td>

<td>Load 5</td><td></td>

<td>3-hydroxy-2-naphthoic acid</td><td> 535.0</td>

<td>triethylamine</td><td> 3.4</td>

Charge 1 was mixed in a 5 liter round bottom flask equipped with an air motor stirrer, a thermocouple, a nitrogen adapter, and a condenser. The mixture was sparged with nitrogen for 15 minutes, and then heated to 80 ° C. Charge 2 was added for 5 minutes, and then held for 3.5 hours. After holding, Charge 3 was added for 5 minutes, and then held for: five hours. The reaction mixture was then filtered through filter paper to remove the copper volume. Charge 4 was then added at 80 ° C, and allowed to stir for 3 hours while exposed to air. The ion exchange resin was then filtered. Charge 5 was then added, and held at 150 ° C for 3 hours. After that, the solvent in the resin was removed by means of vacuum. The resulting material was found to be 98% solid with a number average molecular weight of 2.986 g / mol, a weight average molecular weight of 6159 g / mol, and Mn / Mw of 2.1.

Example 5

Each of the samples from Example 4 (4A, 4B, 4C, 4D, 4E, 4F, 4G, 4H, 41, 4J, 4K and 4L) were applied as 1-2 mm wide lines in a circuit pattern in serpentine into a 5.08 x 7.62 cm (2 x 3 in) glass slide (Fisherbrand, Plain, Precleaned) using a dispensing jet (PICO valve, MV-100, Nordson, EFD) and a desktop robot (2504N, Janome) and then dried in an oven at 100 ° C (212 ° F) for 30 minutes to produce, respectively, Samples 5A, 5B, 5C, 5D, 5E, 5F, 5G, 5H, 51, 5J, 5K and 5L. For each of the coated samples that provided sufficiently robust circuit lines, electrical conductivity was determined by first measuring the resistance of the serpentine circuit against length of the circuit line. The cross-sectional area of ​​the serpentine lines was then measured using a stylus profilometer (Dektak). Using the measured values ​​for the cross-sectional area (A) and resistance (R) for a given length (L) of the circuit, the resistivity (p) was calculated using the equation p = RA / L. The conductivity (o) was then calculated by taking the reciprocal of the resistivity, o = 1 / p. The conductivity results are shown in Table 5. The conductivity results listed in Table 5 are shown graphically in Figure 3.

Table 5

<td>Sample</td><td>Conductivity (S / m)</td><td>Resin</td><td>Solvent</td><td>GCP</td>

<td>5A</td><td> —</td><td>EC</td><td>nmp</td><td>TPG</td>

<td>5B</td><td> —</td><td>SB</td><td>nmp</td><td>TPG</td>

<td>5C</td><td> -</td><td>WB</td><td>DIW / DPM</td><td>TPG</td>

<td>5 D</td><td> 400</td><td>EC</td><td>EtOH</td><td>M-25</td>

<td>5E</td><td> 2600</td><td>EC</td><td>nmp</td><td>M-2 5</td>

<td>5F</td><td> 1600</td><td>SB</td><td>nba</td><td>M-2 5</td>

<td>5G</td><td> 8900</td><td>SB</td><td>nmp</td><td>M-25</td>

<td>5H</td><td> 5900</td><td>- WB</td><td>DIW</td><td>M-25</td>

<td> 51</td><td> 13300</td><td>WB</td><td>DIW / DPM</td><td>M-25</td>

<td>5J</td><td> 7000</td><td>EC</td><td>nmp</td><td>Mix</td>

<td>5K</td><td> 12800</td><td>SB</td><td>nmp</td><td>Mix</td>

<td>5L</td><td> 14900</td><td>WB</td><td>DIW / DPM</td><td>Mix</td>

In Table 5, the symbol indicates samples in which the circuit lines were not as robust as possible.

4 way that could not be measured. The abbreviations in Table 5 are: EC = ethylcellulose; nmp = n-methyl-2-pyrrolidone; GCP = graphene carbon particles; DIW = deionized water; DIW / DPM = 50/50 mixture of deionized water and Dowanol PM; EtOH = ethanol; nba = n-butyl acetate; TPG = thermally produced graphene carbon produced according to the method disclosed in US Patent No. 8,486,364 having a measured surface area of ​​BET 280 µm²/ g; M-25 = xGnP M-25; and Mix = mixture where 92% by weight of the total graphene carbon consisted of xGnP M-25 and 8% by weight of the total graphene carbon was that produced according to the method disclosed in US Patent No. 8,486,364 which has a measured surface area of ​​BET 280 m²/ g.

For the purposes of this detailed description, it should be understood that the invention may involve different alternative variations and sequences of steps, except where expressly specified otherwise. On the other hand, unlike in any, example of operation, or where indicated otherwise, all the numbers that express, for example, amounts of ingredients used in the specification and claims should be understood as modified in all cases by the term approximately. Consequently, unless otherwise stated, the numerical parameters that are set in the

5 The specification and the appended claims are approximations that may vary depending on the properties desired to be obtained by the present invention. Finally, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be interpreted in light of the number of significant digits reported and applying ordinary rounding techniques.

Although the numerical ranges and parameters that establish the broad scope of the invention are approximations, the numerical values ​​that are stated in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors that necessarily result from the standard variation found in their respective test measurements.

Also, it should be understood that any number range recited in this document is intended to include all sub-ranges included therein. For example, a range of 1 to 10 is intended to include all sub-ranges between (and including) the minimum recited value of 1 and the maximum recited value of 10, that is, having a minimum value equal to or greater than 1 and a maximum value equal to or less than 10.

In this application, the use of the singular includes the plural and the plural encompasses the singular, unless specifically stated otherwise. Additionally, in this application, the use of or means and / or unless specifically stated otherwise, although and / or may be used explicitly in certain cases.

It will be readily appreciated by those skilled in the art that modifications can be made to the invention without departing from the concepts disclosed in the foregoing description. Such modifications are to be considered as included within the following claims unless the claims, by their language, expressly state otherwise. Consequently, the particular embodiments described in detail herein are illustrative only and do not limit the scope of the invention to which the full breadth of the appended claims and any and all equivalents thereof must be granted.