The present invention provides a carbon material dispersion in which a carbon material is contained at a high concentration in a liquid medium containing an organic solvent but is unlikely to reaggregate and is stably dispersed, and from which various products, such as an ink capable of forming a coating film having excellent electric conductivity, can be formed. This carbon material dispersion contains a carbon material, an organic solvent, and a polymeric dispersant, wherein the polymeric dispersant is a polymer having 3 to 55% by mass of a constituent unit (1) represented by the following formula (1), wherein R represents a hydrogen atom or the like, A represents O or NH, B represents an ethylene group or the like, R.sub.1 and R.sub.2 each independently represent a methyl group or the like, Ar represents a phenyl group or the like, X represents a chlorine atom or the like, and p represents an arbitrary number of repeating units, and the polymeric dispersant has an amine value of 100 mgKOH/g or less and a number average molecular weight of 5,000 to 20,000.

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The present invention provides a carbon material dispersion in which a carbon material is contained at a high concentration in a liquid medium containing an organic solvent but is unlikely to reaggregate and is stably dispersed, and from which various products, such as an ink capable of forming a coating film having excellent electric conductivity, can be formed. This carbon material dispersion contains a carbon material, an organic solvent, and a polymeric dispersant, wherein the polymeric dispersant is a polymer having 3 to 55% by mass of a constituent unit (1) represented by the following formula (1), wherein R represents a hydrogen atom or the like, A represents O or NH, B represents an ethylene group or the like, R.sub.1 and R.sub.2 each independently represent a methyl group or the like, Ar represents a phenyl group or the like, X represents a chlorine atom or the like, and p represents an arbitrary number of repeating units, and the polymeric dispersant has an amine value of 100 mgKOH/g or less and a number average molecular weight of 5,000 to 20,000.

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The invention relates to an oil-in-water emulsion comprising an oil phase and an aqueous phase, and a primary surfactant, wherein the oil phase is dispersed in the aqueous phase, and wherein the oil-in-water emulsion has: an average droplet size distribution (D[4,3]) in the range of from 3 to 15 um and less than 3 wt % of the droplets have a particle size of greater than 125 um; a viscosity of greater than 100 and up to 700 mPas at 50 C.+10% and 20 s.sup.1+10%; and a static stability of less than 5% residue after centrifugation at 50 C.+10% and 2000 g=10% for 30 minutes+10%.

Suggested are new microbial glycolipids of formula (I), wherein X stands for nitrogen or oxygen; R.sup.1 represents hydrogen, CO-Alkyl, CO-Aryl, CON-Alkyl, CON-Aryl, SO.sub.2-Alkyl, SO.sub.2-Aryl, CO(CH.sub.2).sub.n COOH with n=1 to 4, or an amino acid; R.sup.2 represents OH or O-Glucose; R.sup.3 represents hydrogen or OH; n 1 or 2 has the meaning of a single or double bond.

Suggested are new microbial glycolipids of formula (I), wherein X stands for nitrogen or oxygen; R.sup.1 represents hydrogen, CO-Alkyl, CO-Aryl, CON-Alkyl, CON-Aryl, SO.sub.2-Alkyl, SO.sub.2-Aryl, CO(CH.sub.2).sub.n COOH with n=1 to 4, or an amino acid; R.sup.2 represents OH or O-Glucose; R.sup.3 represents hydrogen or OH; n 1 or 2 has the meaning of a single or double bond.

The present invention relates to a dispersant composition comprising: a) at least one oligomeric acid A, which has i) at least one acidic group selected from COOH and PO.sub.3H.sub.2, and ii) at least one polyoxyalkylene-ether radical of the formula (I): R(O-A).sub.xO-G-, where A is an C.sub.2-C.sub.4-alkan-1,2-diyl radical; X is an integer having a number average value in the range from 2 to 20; and R is hydrocarbon radical having from 1 to 30 carbon atoms; G is a chemical bond or a carbonyl group; and b) at least one polyamine B, which is selected from the group consisting of polyvinylamines, poly-C.sub.2-C.sub.3-alkyleneimines, modified poly-C.sub.2-C.sub.3-alkyleneimines, melamine compounds, modified melamine compounds, poly-(C.sub.2-C.sub.4-alkyleneether) amines, polyetheramine polyols, and modified polyetheramine polyols. The invention also relates to aqueous pigment compositions containing a dispersant composition as defined herein, a pigment component, selected from the group consisting of pigments and mixtures of at least one pigment and at least one filler, and an aqueous diluent.

The invention relates to an oil-in-water emulsion comprising an oil phase and an aqueous phase, and a primary surfactant, wherein the oil phase is dispersed in the aqueous phase, and wherein the oil-in-water emulsion has: an average droplet size distribution (D[4,3]) in the range of from 3 to 15 m and less than 3 wt % of the droplets have a particle size of greater than 125 m; a viscosity of greater than 100 and up to 700 mPas at 50 C.10% and 20 s.sup.110%; and a static stability of less than 5% residue after centrifugation at 50 C.10% and 2000 g=10% for 30 minutes10%. A process for preparing such an oil-in-water emulsion comprises preparing an aqueous phase comprising a primary surfactant, heating a hydrocarbon-containing oil-phase, and blending the hydrocarbon-containing oil and the aqueous phase under conditions sufficient to form an oil-in-water emulsion. The invention also relates to methods for determining the static and dynamic stability of oil-in-water emulsions. Static stability can be determined by a method comprising the steps of: providing an oil-in-water emulsion; centrifuging the oil-in-water emulsion under predetermined conditions for a predetermined period of time; determining the amount of residue deposited from the oil-in-water emulsion after the predetermined period of time; and determining the oil-in-water emulsion's static stability. A method for determining the dynamic stability of an oil-in-water emulsion comprises the steps of: providing an oil-in-water emulsion; analysing the oil-in-water emulsion at a first time; recirculating the oil-in-water emulsion in a recirculation loop; and analysing the oil-in-water emulsion at second time after recirculation has started; in which the oil-in-water emulsion's dynamic stability is determined based on the analysis at the first and second times.

The present invention provides a carbon material dispersion in which a carbon material is contained at a high concentration in a liquid medium containing an organic solvent but is unlikely to reaggregate and is stably dispersed, and from which various products, such as an ink capable of forming a coating film having excellent electric conductivity, can be formed. This carbon material dispersion contains a carbon material, an organic solvent, and a polymeric dispersant, wherein the polymeric dispersant is a polymer having 3 to 55% by mass of a constituent unit (1) represented by the following formula (1), wherein R represents a hydrogen atom or the like, A represents O or NH, B represents an ethylene group or the like, R.sub.1 and R.sub.2 each independently represent a methyl group or the like, Ar represents a phenyl group or the like, X represents a chlorine atom or the like, and p represents an arbitrary number of repeating units, and the polymeric dispersant has an amine value of 100 mgKOH/g or less and a number average molecular weight of 5,000 to 20,000. ##STR00001##

The present invention provides a carbon material dispersion in which a carbon material is contained at a high concentration in a liquid medium containing an organic solvent but is unlikely to reaggregate and is stably dispersed, and from which various products, such as an ink capable of forming a coating film having excellent electric conductivity, can be formed. This carbon material dispersion contains a carbon material, an organic solvent, and a polymeric dispersant, wherein the polymeric dispersant is a polymer having 3 to 55% by mass of a constituent unit (1) represented by the following formula (1), wherein R represents a hydrogen atom or the like, A represents O or NH, B represents an ethylene group or the like, R.sub.1 and R.sub.2 each independently represent a methyl group or the like, Ar represents a phenyl group or the like, X represents a chlorine atom or the like, and p represents an arbitrary number of repeating units, and the polymeric dispersant has an amine value of 100 mgKOH/g or less and a number average molecular weight of 5,000 to 20,000. ##STR00001##

A wellbore fluid includes a base fluid and an emulsifier composition comprising an emulsifier and glycerol. The emulsifier comprises a reaction product of a bis-amide and at least one of maleic acid, maleic anhydride, fumaric acid, succinic acid, or succinic anhydride. The bis-amide includes a reaction product of one or more fatty acid esters and a polyalkylamine. Related methods of operating a wellbore and forming the emulsifier composition are also disclosed.