COATING LIQUID FOR FORMING POROUS SILICA-BASED COATED LAYER, BASE MATERIAL WITH COATED LAYER AND SHORT FIBER TYPE SILICA

摘要

PROBLEM TO BE SOLVED: To provide a coating liquid for forming a porous silica-based coated layer which can form an insulation layer showing good adherence to a surface to be coated, good mechanical properties, good resistances to chemicals and cracking and make undulation of the surface smooth, a base material coated with a porous silica-based layer having such excellent properties and short fiber type silica. SOLUTION: Coating liquid for forming a porous silica-based coated layer contains a reaction product of (i) short fiber type silica with (ii) a decomposed compound by hydrolysis of an alkoxysilane represented by Xn Si(OR)4-n or a halogenated silane represented by Xn SX'4-n (X is hydrogen, fluorine, an alkyl group having 1-8 carbon atoms, an aryl group or a vinyl group; R is hydrogen, an alkyl group having 1-8 carbon atoms, an aryl group or a vinyl group; X' is chlorine or bromine; and n is an integer of 0 to 3). A base material with a coated layer has a porous silica-based coated layer formed by use of a coating liquid for forming a porous silica-based coated layer. Short fiber type silica has a diameter of 10-30 nm, length (L) of 30-100 nm and an aspect ratio (L/D) of 3-10.