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%.

The invention relates to a process for producing at least one alkoxylated polyphenol comprising the following successive steps: (a) reacting at least one polyphenol, at least one alkoxylating agent, at least one catalyst, in the presence of at least one alkoxylated polyphenol as a solvent, the polyphenol/polyphenol alkoxylated weight ratio as a solvent being less than 2, preferably less than or equal to 1.5, more preferably less than or equal to 1, even more preferably less than or equal to 0.5; (b) removing the residual alkoxylating agent;

A stable aqueous dispersion of solids in a liquid medium includes from 10 to 50 weight % (or 10 to 40 or 15 to 35 or 20 to 35 weight %), with respect to the total weight of the composition, of solids comprising a mixture of condensed and non-condensed lignin in an amount of at least 10 weight % (or 20 or 30 or 40 or 50 weight %) of the solids, and hemicellulose in an amount of at least 1 weight % (or 5 or 10 or 20 or 30 or 40 weight %) of the solids, in a substantially aqueous liquid medium.

The present invention provides a hydrolysate of a lignocellulosic material, and specifically a method of using a hydrolysis treatment liquid obtained by a hydrolysis treatment of a lignocellulosic material before kraft cooking in order to obtain dissolving pulp for uses other than use of a fuel. Specifically, the present invention provides a dispersant containing the hydrolysate obtained by hydrolysis treatment of the lignocellulosic material. The dispersant of the present invention has excellent dispersibility for a substance such as an inorganic substance and an organic substance without limitation of powder, particulate, granular, fiber, and flat plane shapes.

An oil-in-water emulsion comprising an aqueous phase, an oil phase, and an adsorption layer at the interface of the two phases, said adsorption layer consisting of a lignin matrix into which metal oxide nanoparticles are incorporated, characterised in that the lignin is present in a quantity of less than 2 wt. %, in particular in a quantity of between 0.5 wt. % and 2 wt. %, and in that the metal oxide nanoparticles are present in a quantity less than or equal to 1.5 wt. %, in particular in a quantity of between 0.5 wt. % and 1.5 wt. %, relative to the total weight of the emulsion.

The use of lignin in an oil-in-water emulsion, the oil phase representing at least 50 wt. % of the emulsion, in order to delay the evaporation of the oil phase and/or increase the mechanical strength of the adsorption layer formed by the lignin.

According to an example aspect of the present invention, there is provided a dispersant comprising alkaline-O.sub.2 oxidized lignin. Such dispersant may be used for example in inorganic pigments to reduce interactions between pigment particles and lower the viscosity of pigment mixtures, and thereby positively affect for example to the loading of fillers and pigments in paints and coatings, paper and board, constructions materials, printing inks and plastics. Dispersants may also be used in aiding the inorganic pigment grinding in the pigment mine. Another suitable use is as a plasticizer or as a retardant agent for construction materials, such as gypsum.

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.

From the viewpoint of a decrease in environmental impact in recent years, an object of the present invention is to effectively utilize lignin as a circulative biomass resource having high effect of reducing environmental impact. Specifically, the object is to provide a lignin derivative that can improve the dispersibility of various substances to be dispersed regardless of uses of cements, dyes, oil field drilling mud, and the like. The present invention provides a lignin derivative compound that is a reaction product of a lignin sulfonic acid-based compound with an aromatic water-soluble compound, and a dispersant containing the same. The lignin derivative compound preferably has an anionic functional group and/or a polyalkylene oxide chain.

A composition includes a polymer-grafted lignin formed by grafting one or more hydrophilic polyalkylene oxide polymers with lignin, wherein the average grafting density of the polymer-grafted lignin is less than 10 per lignin particle and the weight fraction of the one or more hydrophilic polyalkylene oxide polymers in the polymer grafted lignin is less than 40%.