Refractory laminate based on negative sols or silicates and polymeric lattices containing cationic surfactants

Abstract

Abstract A RAPID PROCESS FOR FORMING A REFRACTORY LAMINATE ON THE SURFACE OF A SUPPORT STRUCTURE WHICH COMPRISES DIPPING THE STRUCTURE IS A BATH COMPRISING A SOL OF NEGATIVELY CHARGED COLLOIDAL PARTICLES OF AN INORGANIC SUBSTANCE AND/ OR A SOLUTION OF AN ALKALINE IONIC SILICATE TO FORM A COATING ON THE SURFACE, CONTACTING THE COATED SURFACE WITH A SETTING AGENT, AN ORGANIC POLYMERIC LATEX CONTAINING A CATIONIC SURFACTANT TO FIRMLY SET THE COLLOIDAL SILICA OR SILICATE. THIS PROCEDURE IS REPEATED UNTIL A LAMINATE OF THE DESIRED THICKNESS IS BUILT UP ON THE SURFACE. IN ORDER TO INCREASE THE RATE OF LAMINATE BUILD-UP PARTICULATE REFRACTORY MATERIAL CAN BE INCLUDED IN THE BATH AND/OR THE COATED SURFACE CAN BE STUCCOED BETWEEN DIPS. INTERACTION BETWEEN THE NEGATIVELY CHARGED COLLODIAL PARTICLES OR SLICATE AND THE CATIONIC SURFACTANT SETTING AGENT RESULTS IN DESTABILIZATION OF THE LATEX, POLYMERIZATION OF THE SILICA OR SILICATE AND AGGREGATION OF SILICA-POLYMER PARTICLES AND THEREBY THE IMMOBILIZATION OF THE COATINGS. THIS TECHNIQUE MAKES IT POSSIBLE TO SUCCESSIVELY APPLY AND SET COATINGS TO BUILD REFRACTORY LAMINATES IN VERY SHORT TIMES WITHOUT INTERMEDIATE DRYING AND WITHOUT SLOUGHING OF COATS. THE PROCESS IS PARTICULARLY SUITED FOR MAKING EXPENDABLE, REFRACTORY SHELL MOLDS FOR PRECISION INVESTMENT CASTING OF METALS BY THE SO-CALLED "LOST-WAX" TECHNIQUE.

Inventors

• 👤 E Moore

Bibliographic Details