Abstract: The present invention provides a wellbore fluid, such as a drilling, completion or workover fluid, said wellbore fluid comprising a glucomannan additive. Further provided is a method of forming a gel plug from the wellbore fluid, a method of modifying the properties of a wellbore fluid, a method of drilling a subterranean hole with such a fluid and the use of glucomannan in wellbore fluids.

Abstract: A method of grafting galactomannan-type polysaccharide polymers, preferably guar, to a functional group by irradiation with high energy electron beams in the presence of an unsaturated monomer-compressing the described functional group. The method may include the depolymerization of the grafted polymer to a pre-selected low molecular weight. The preferred galactomannans for treatment according to this method are guar gum, guar splits and hydroxypropyl guar. In a preferred embodiment the guar gum is also depolymerized, preferably to a molecular weight of below about 700,000 Daltons, and most preferably to a molecular weight of between about 100,000 Daltons to about 250,000 Daltons. The depolymerized guar most preferably has a polydispersity of less than about 3.0 and is useful in oil well fracturing to enhance oil production.

Abstract: A pseudoplastic water based ink for a ball-point pen comprising at least a colorant, water and an associative type viscosity control system, whereby the viscosity of the ink is comprised in a range from 20 to 40 mPa.s, when it is subjected to a shear rate of 1000 s−1, and between 10,000 and 12,000 mPa.s, when the shear rate is 1 s−1.

Abstract: An ink composition comprising at least one color suitable for food use and a liquid vehicle including water and an organic solvent miscible with water in a volumetric ratio variable from 3:1 to 1:10, wherein the organic solvent is ethanol or a mixture ethanol:acetone in a volumetric ratio variable from 1:2 to 3:1; this ink composition is suitable, in particular, even though not exclusively, for surface coloring and printing on supports, wrappings and objects intended for coming into contact with foods.

Abstract: Provided is a water based ink composition for a ball point pen comprising at least one selected from the group consisting of an alkylene oxide adduct of polyglycerin, an alkylene oxide adduct of glycerin and an alkylene oxide adduct of trimethylolpropane and further comprising a colorant, a white plastic pigment, a viscosity-controlling agent and water. The ink composition is excellent in a writing property as well as a coloring property of the drawn lines regardless of the kind of writing paper and is stable with the passage of time. In addition thereto, it provides the drawn lines with a color having the same color tone as that of the visual color when it is charged into an ink reservoir.

Abstract: An aqueous ink for a ball-point pen which is stable over time and has high pigment dispersion stability, includes a pigment, a water-soluble organic solvent, water, xanthane gum of about 0.01 to about 0.2 wt. % and a sodium alginate of about 0.2 to about 0.6 wt. % of a total amount of the ink.