摘要:
Provided is a method of producing porous silica-based particles with the relatively larger average diameter of 1 micron or more and also having a low particle density. The method comprises the steps of (a) preparing two-layer separated liquid consisting of an organic silicon compound layer and a water layer, then adding an organic solvent, an alkali, and a surfactant into the water layer while agitating at least the water layer so that the organic silicon compound layer and the water layer are not completely mixed with each other, further hydrolyzing and/or partial hydrolyzing the organic silicon compound in the mixed aqueous solution to prepare silica-based particle precursors, (b) adding sodium aluminate into the mixed aqueous solution containing the silica-based particle precursors and then preparing silica-based particles having pores, cavities or voids inside the particles, and (c) washing and drying the silica-based particles. Thus obtained particles are useful for various applications such as microcapsules, adsorbents, catalysts, low refractive film, low dielectric film and low reflectivity film.
摘要:
The present invention provides a sol of spinous inorganic oxide particles not containing coarse particles, in which particles having extremely homogeneous particles are dispersed in a solvent. An acidic silicic acid is added to a dispersion liquid of core particles to grow core particles, and then again the acidic silicic acid is added at the addition rate 1.2 to 1.8 higher than that in the previous step to prepare a sol of spinous inorganic oxide particles. Then the sol is subjected to centrifugation to remove coarse particles having the diameter of 800 nm or more, thus spinous inorganic oxide particles having peculiar form such as a spinous one being obtained.
摘要:
The present invention provides a sol of spinous inorganic oxide particles not containing coarse particles, in which particles having extremely homogeneous particles are dispersed in a solvent. An acidic silicic acid is added to a dispersion liquid of core particles to grow core particles, and then again the acidic silicic acid is added at the addition rate 1.2 to 1.8 higher than that in the previous step to prepare a sol of spinous inorganic oxide particles. Then the sol is subjected to centrifugation to remove coarse particles having the diameter of 800 nm or more, thus spinous inorganic oxide particles having peculiar form such as a spinous one being obtained.
摘要:
Porous silica-based particles with relatively larger average diameter of 1 micron or more and a low particle density are prepared. The method includes the steps of (a) preparing two-layer separated liquid including an organic silicon compound layer and a water layer, then adding an organic solvent, an alkali, and a surfactant into the water layer while agitating at least the water layer so that the organic silicon compound layer and the water layer are not completely mixed with each other, further hydrolyzing and/or partial hydrolyzing the organic silicon compound in the mixed aqueous solution to prepare silica-based particle precursors, (b) adding sodium aluminate into the mixed aqueous solution containing the silica-based particle precursors and then preparing silica-based particles having pores, cavities or voids inside the particles, and (c) washing and drying the silica-based particles. The particles are useful for various applications such as microcapsules, adsorbents, catalysts, and so on.
摘要:
A coating liquid for forming porous silica coating, comprising a product of reaction between a short fiber silica and a hydrolyzate of an alkoxysilane of the formula XnSi(OR)4-n or a halogenated silane of the formula XnSiX′4-n (in the formula, X represents a hydrogen atom, a fluorine atom, an alkyl group having 1 to 8 carbon atoms, an aryl group or a vinyl group; R represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an aryl group or a vinyl group; X′ represents a chlorine atom or a bromine atom; and n is an integer of 0 to 3). A coated substrate comprising a porous silica coating film formed from the above coating liquid for forming porous silica coating. A short fiber silica having an average diameter (D) of 10 to 30 nm, a length (L) of 30 to 100 nm and an aspect ratio (L/D) of 3 to 10. The above coating liquid for forming porous silica coating enables forming an insulating film which is excellent in adherence to a substrate surface, mechanical strength, chemical resistance and crack resistance and enables flattening irregularities of a substrate surface to a high degree. The coating film of the coated substrate has the above excellent properties.
摘要:
The present invention provides a method of forming on a substrate a particle layer highly adherent to the substrate, which comprises the steps of spreading a dispersion (I) comprising a dispersing medium and, dispersed therein, solid particles being surface treated with a compound acting as a binder on a liquid (II) having a specific gravity higher than that of the dispersing medium, said liquid (II) being immiscible with the dispersing medium, subsequently removing the dispersing medium from the dispersion (I) to thereby arrange the solid particles on the liquid (II) so that a particle layer is formed on the liquid (II) and thereafter transferring the particle layer onto a substrate. Moreover, the present invention provides a method of planarizing an irregular surface of a substrate, which comprises transferring the above particle layer to an irregular surface of a substrate and removing parts of the particle layer formed on protrudent parts of the substrate to thereby planarize the irregular surface of the substrate and also provides a particle-layer-formed substrate comprising a substrate and, superimposed on a surface thereof, the particle layer obtained by each of the above methods.
摘要:
A coating liquid for forming porous silica coating, comprising a product of reaction between a short fiber silica and a hydrolyzate of an alkoxysilane of the formula X.sub.n Si(OR).sub.4-n or a halogenated silane of the formula X.sub.n SiX'.sub.4-n (in the formula, X represents a hydrogen atom, a fluorine atom, an alkyl group having 1 to 8 carbon atoms, an aryl group or a vinyl group; R represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an aryl group or a vinyl group; X' represents a chlorine atom or a bromine atom; and n is an integer of 0 to 3). A coated substrate comprising a porous silica coating film formed from the above coating liquid for forming porous silica coating. A short fiber silica having an average diameter (D) of 10 to 30 nm, a length (L) of 30 to 100 nm and an aspect ratio (L/D) of 3 to 10. The above coating liquid for forming porous silica coating enables forming an insulating film which is excellent in adherence to a substrate surface, mechanical strength, chemical resistance and crack resistance and enables flattening irregularities of a substrate surface to a high degree. The coating film of the coated substrate has the above excellent properties.
摘要:
Transparent conductive coatings excellent in transparency are provided on substrates such as glass, plastics, etc. by the use of conductive coating materials obtained by maintaining aqueous solutions of hydrolyzable tin containing or indium containing compounds at pH of 8-12, and gradually hydrolyzing said compounds in the solutions to form sols containing colloidal particles, followed by drying and calcining.
摘要:
The present invention provides a sol of spinous silica-based particles in which silica-based particles having peculiar forms, spinous forms are dispersed in a solvent. The spinous silica-based particles have verrucous projections formed on surfaces of spherical silica-based particles. In the spinous particles, a value of the surface roughness (SA1/SA2, SA1 indicating a specific surface area measured by the BET method or the Sears method and SA2 indicating a specific surface area converted from an average particle diameter (D2) measured by the image analysis method) is in the range from 1.7 to 10. Furthermore the average diameter (D2) measured by the image analysis method is in the range from 7 to 150 nm.
摘要:
Silica particles for polishing have a three-dimensional polycondensation structure with an average particle diameter in a range from 5 to 300 nm. The silica particles have residual alkoxy groups therein and a carbon content in a range from 0.5 to 5 weight % retained in the residual alkoxy groups.