Abstract: A dispersion wherein dispersoid particles including colloidal silica and zinc cyanurate are dispersed in a liquid medium. The colloidal silica particles may have an average diameter of 5 to 500 nm, and the dispersion may contain 0.1 to 40% by mass of the particles in terms of SiO2 concentration. Primary particles of the zinc cyanurate may have a major axis length of 50 to 1000 nm, a minor axis length of 10 to 300 nm, and a ratio of major to minor axis length of 2 to 25, and the dispersion may contain 0.1 to 50% by mass of the particles in terms of solids content. A mass ratio of the colloidal silica to the zinc cyanurate particles may be 1:0.01 to 100, and total solids content may be 0.1 to 50% by mass. The liquid medium may be water or an organic solvent.

Abstract: A borehole cement slurry additive that is capable of suppressing the generation of free water from cement slurries in any environment, whether cold regions, mild regions, or hot regions; and a method for storing the same. The borehole cement slurry additive contains: an aqueous dispersion of silica having an average particle size of 3-200 nm as determined via dynamic light scattering; and a compound having an alcoholic hydroxyl group as a dispersion stabilizer, the compound being included in an amount of 1-30 mol per 1,000 g dispersion medium in the aqueous silica dispersion.

Abstract: A fishing rod includes a hollow rod extending along a central axis; and a shaft member with an outer peripheral surface inclined relative to the central axis inserted into the rod from the one end, and that is supported by an inner peripheral surface of the rod at a support position on another end side of the one end in an axial direction along the central axis, wherein the inner peripheral surface of the rod has at least one convex portion protruding toward the central axis from a virtual curve between the support position and the one end position axially when drawing a virtual curve that is convex toward the central axis through the support position and the one end position at the end of the end side of the inner peripheral surface in an area radially outward from the outer peripheral surface of the shaft member.

Abstract: An additive capable of suppressing generation of free water from a cement slurry even under a high temperature environment of 150° C. or more and a silica-based additive that suppresses, in a cement slurry for cementing in oil fields and gas oil fields, free water under high temperature and high pressure environments of 100° C. or more, the silica-based additive containing an aqueous silica sol containing nanosilica particles with a true density of 2.15 g/cm3 or more and less than 2.30 g/cm3, and a cement slurry for cementing that contains the silica-based additive.

Abstract: An additive for a cement slurry for a well that is capable of suppressing the generation of free water and preventing flotation/separation of low-specific-gravity aggregate while securing sufficient cement strength even at a high temperature and a method for producing this additive are disclosed. The additive contains an aqueous dispersion of silica and a layered silicate.

Abstract: Provided is an additive for a cement slurry for a well that is capable of suppressing the generation of free water and preventing flotation/separation of low-specific-gravity aggregate while securing sufficient cement strength even at a high temperature. Also provided is a method for producing this additive. This additive for a cement slurry for a well contains an aqueous dispersion of silica and a layered silicate.

Abstract: Provided are: a borehole cement slurry additive that is capable of suppressing the generation of free water from cement slurries in any environment, whether cold regions, mild regions, or hot regions; and a method for storing the same. The borehole cement slurry additive contains: an aqueous dispersion of silica having an average particle size of 3-200 nm as determined via dynamic light scattering; and a compound having an alcoholic hydroxyl group as a dispersion stabilizer, the compound being included in an amount of 1-30 mol per 1,000 g dispersion medium in the aqueous silica dispersion.

Abstract: A fishing rod includes a hollow rod extending along a central axis; and a shaft member with an outer peripheral surface inclined relative to the central axis inserted into the rod from the one end, and that is supported by an inner peripheral surface of the rod at a support position on another end side of the one end in an axial direction along the central axis, wherein the inner peripheral surface of the rod has at least one convex portion protruding toward the central axis from a virtual curve between the support position and the one end position axially when drawing a virtual curve that is convex toward the central axis through the support position and the one end position at the end of the end side of the inner peripheral surface in an area radially outward from the outer peripheral surface of the shaft member.

Abstract: An additive capable of suppressing generation of free water from a cement slurry even under a high temperature environment of 150° C. or more and a silica-based additive that suppresses, in a cement slurry for cementing in oil fields and gas oil fields, free water under high temperature and high pressure environments of 100° C. or more, the silica-based additive containing an aqueous silica sol containing nanosilica particles with a true density of 2.15 g/cm3 or more and less than 2.30 g/cm3, and a cement slurry for cementing that contains the silica-based additive.

Abstract: A dispersion wherein dispersoid particles including colloidal silica and zinc cyanurate are dispersed in a liquid medium. The colloidal silica particles may have an average diameter of 5 to 500 nm, and the dispersion may contain 0.1 to 40% by mass of the particles in terms of SiO2 concentration. Primary particles of the zinc cyanurate may have a major axis length of 50 to 1000 nm, a minor axis length of 10 to 300 nm, and a ratio of major to minor axis length of 2 to 25, and the dispersion may contain 0.1 to 50% by mass of the particles in terms of solids content. A mass ratio of the colloidal silica to the zinc cyanurate particles may be 1:0.01 to 100, and total solids content may be 0.1 to 50% by mass. The liquid medium may be water or an organic solvent.

Abstract: A crude oil recovery chemical fluid is described and claimed. This fluid has been shown to exhibit excellent resistance to salt and high temperatures. This crude oil recovery chemical fluid includes a silane compound, an aqueous silica sol having an average particle diameter of from about 3 nm to about 200 nm, two or more anionic surfactants, and one or more nonionic surfactants.

Abstract: A crude oil recovery chemical fluid is described and claimed. This fluid has been shown to exhibit excellent resistance to salt and high temperatures. This crude oil recovery chemical fluid includes a silane compound, an aqueous silica sol having an average particle diameter of from about 3 nm to about 200 nm, two or more anionic surfactants, and one or more nonionic surfactants.

Abstract: A crude oil recovery chemical fluid is described and claimed. This fluid has been shown to exhibit excellent resistance to salt and high temperatures. This crude oil recovery chemical fluid includes a silane compound, an aqueous silica sol having an average particle diameter of from about 3 nm to about 200 nm, two or more anionic surfactants, and one or more nonionic surfactants.

Abstract: A crude oil recovery chemical fluid is described and claimed. This fluid has been shown to exhibit excellent resistance to salt and high temperatures. This crude oil recovery chemical fluid includes a silane compound, an aqueous silica sol having an average particle diameter of from about 3 nm to about 200 nm, two or more anionic surfactants, and one or more nonionic surfactants.

Abstract: A method produces a basic zinc cyanurate powder, the amount of a portion thereof which remains in a sieve having a mesh size of 1,000 ?m being less than 1 mass %. The method includes heating, at 30 to 300° C., a powder-form mixture which is composed of zinc oxide, cyanuric acid, and water, which has a ratio by mole of zinc oxide to cyanuric acid of 2 to 3, and which has a water content of 9 to 18 mass %, in a closed or unclosed state.

Abstract: A method produces a basic zinc cyanurate powder, the amount of a portion thereof which remains in a sieve having a mesh size of 1,000 ?m being less than 1 mass %. The method includes heating, at 30 to 300° C., a powder-form mixture which is composed of zinc oxide, cyanuric acid, and water, which has a ratio by mole of zinc oxide to cyanuric acid of 2 to 3, and which has a water content of 9 to 18 mass %, in a closed or unclosed state.

Abstract: Basic zinc cyanurate fine particles are produced by subjecting a mixed slurry to wet dispersion using a dispersion medium at a temperature in the range of 5 to 55° C., the mixed slurry being formed by blending water, cyanuric acid, and at least one component selected from zinc oxide and basic zinc carbonate such that the cyanuric acid concentration is 0.1 to 10.0 mass % with respect to water.

Abstract: Basic zinc cyanurate fine particles are produced by subjecting a mixed slurry to wet dispersion using a dispersion medium at a temperature in the range of 5 to 55° C., the mixed slurry being formed by blending water, cyanuric acid, and at least one component selected from zinc oxide and basic zinc carbonate such that the cyanuric acid concentration is 0.1 to 10.0 mass % with respect to water.