Showing papers by "Sumio Sakka published in 1981"

Method of producing glass from metal alkoxide solution

Abstract: In producing silica glass, which may contain additional metal(s) such as Ti or Zr, from a solution of a silicon alkoxide, mixed with alkoxide(s) of the additional metal(s) where necessary, in water and a hydrophilic organic solvent by shaping the solution into a desired form such as a coating film on a substrate, self-supporting film, fiber or lump when the solution exhibits a suitably high viscosity and sufficiently heating the shaped solution, a water-soluble organic polymeric substance is added to the solution as a viscosity adjusting agent to soon increase the viscosity of the solution to the desirable level. Therefore, shaping of the solution can be performed without awaiting the progress of hydrolysis of the alkoxide in the solution, and the glass can be obtained with improved uniformity of its properties. A cellulose ether is preferred as the viscosity adjusting agent, and hydroxypropyl cellulose is particularly preferable.

Kinetic Study on Non-Isothermal Crystallization of Glass by Thermal Analysis (Commemoration Issue Dedicated to Professor Megumi Tashiro on the Occation of his Retirement)

Abstract: Kinetic Study on Non-Isothermal Crystallization of Glass by Thermal Analysis (Commemoration Issue Dedicated to Professor Megumi Tashiro on the Occation of his Retirement) Author(s) Matsushita, Kazumasa; Sakka, Sumio Citation Bulletin of the Institute for Chemical Research, Kyoto University (1981), 59(3): 159-171 Issue Date 1981-09-01 URL http://hdl.handle.net/2433/76947 Right Type Departmental Bulletin Paper Textversion publisher

of Glass by Thermal Analysis

Abstract: For the purpose of analyzing the crystallization of glass by thermal analysis, a modified Ozawa-type equation and a modified Kissinger-type equation were derived on the basis of the nucleation and growth equations, and the validity of these equations was ascertained by applying to Li5O.2SiO2 glass whose kinetic data of crystallization were available. The modified Kissinger-type equation was identical with the so-called Kissinger equation only when the crystallization started at the surface, proceeding towards the inside of glass one-dimensionally. The modified Ozawa-type equation was identical with the socalled Ozawa equation when the number of crystal particles was constant irrespective of heating rate. The conditions under which these equations could be applied were discussed. It was concluded that the crystallization mechanism should be known in order to obtain the meaningful activation energy for crystallization by applying these equations.

Process for production of glass from a metal alkoxide solution

Abstract: In the production of quartz glass, which may contain additional metals, for example Ti or Zr, from a solution of a silicon alkoxide, if necessary mixed with one or more alkoxides of an additional or additional metals, in water and a hydrophilic organic solvent, in which the solution is brought into a desired form, for example a coating on a substrate, a self-supporting layer, fibres or clumps, if the solution has a suitably high viscosity, and in which the shaped solution is sufficiently heated, a water-soluble organic polymeric substance is added to the solution as an agent for adjusting the viscosity so that the viscosity of the solution soon rises to the desired value. The shaping of the solution can therefore be carried out without having to await continuation of hydrolysis of the alkoxide in the solution, and the glass can be obtained with better uniformity of its properties. The agent for adjusting the viscosity is preferably a cellulose ether, and hydroxypropylcellulose is particularly preferred.

Procede de production de verres de silice et procede de recouvrement en verres de silice a partir d'une solution d'un alcoolate d'un metal

Abstract: LA PRESENTE INVENTION CONCERNE UN PROCEDE DE PRODUCTION DE VERRE A PARTIR D'UNE SOLUTION CONTENANT UN ALCOOLATE DE SILICIUM, DE L'EAU ET UN SOLVANT ORGANIQUE HYDROPHILE, EN CONFIGURANT LA SOLUTION A UNE FORME SOUHAITEE QUAND ELLE PRESENTE UNE VISCOSITE APPROPRIEE ET EN CHAUFFANT LA SOLUTION CONFIGUREE A UNE TEMPERATURE SUFFISANTE POUR LA CONVERTIR EN UN VERRE DE LA FORME SOUHAITEE. SELON L'INVENTION, ON AJOUTE UNE SUBSTANCE POLYMERIQUE ORGANIQUE SOLUBLE DANS L'EAU A LA SOLUTION, EN TANT QU'AGENT D'AJUSTEMENT DE LA VISCOSITE, POUR FORCER LA SOLUTION RESULTANTE A PRESENTER RAPIDEMENT LA VISCOSITE APPROPRIEE; LE DESSIN JOINT MONTRE LES CHANGEMENTS DE VISCOSITE DE SOLUTIONS PREPAREES EXPERIMENTALEMENT D'ALCOOLATES METALLIQUES AVEC L'ECOULEMENT DU TEMPS. L'INVENTION S'APPLIQUE NOTAMMENT A L'INDUSTRIE DU VERRE.

Procede de production d'une pellicule de verre en utilisant une solution contenant de l'alcoolate de silicium

Abstract: L'INVENTION CONCERNE UN PROCEDE DE PRODUCTION D'UNE PELLICULE DE VERRE. SELON L'INVENTION, IL CONSISTE A PREPARER UNE SOLUTION D'ALCOOLATE CONTENANT UN ALCOOLATE DE SILICIUM, DE L'EAU ET UN SOLVANT ORGANIQUE HYDROPHILE; A LAISSER L'ALCOOLATE DE SILICIUM DANS LA SOLUTION S'HYDROLYSER JUSQU'A CE QUE CETTE SOLUTION DEVIENNE UNE SOLUTION VISQUEUSE DE FACON APPROPRIEE; A FORMER UNE PELLICULE DE LA SOLUTION VISQUEUSE DANS UN ESPACE LIBRE; ET A CHAUFFER LA PELLICULE JUSQU'A UNE TEMPERATURE SUFFISANTE POUR LA CONVERTIR EN UNE PELLICULE DE VERRE. L'INVENTION S'APPLIQUE NOTAMMENT A LA FORMATION DE PELLICULES DE PROTECTION POUR AUTRES VERRES, MATIERES PLASTIQUES ET AUTRES.