Liquid sodium silicate having improved water resistance property its preparation and use

PURPOSE: Provided is a liquid sodium silicate with improved water resistance after being dried and having increased flexibility, wherein at least one Si in a network structure of the liquid sodium silicate is substituted with B, P or Al, and further provided is a method for preparing the same liquid sodium silicate and its use. CONSTITUTION: The liquid sodium silicate has a network structure being comprised of SiO4, wherein at least one Si of the network structure is substituted with other elements selected from a group consisted of B, P and Al. The method comprises the steps of (a) adding complex network structure formation additives containing one or more elements selected from a group consisted of B, P and Al to a starting material of glassy sodium silicate by 0.1 to 10 wt.%, wherein the starting material is Si sand or Na2CO3, thereby producing glassy sodium silicate solution, (b) dissolving the glassy sodium silicate by applying heat and pressure, and (c) concentrating the solution obtained at the step (b) at a temperature in the range of 60 to 80 deg.C, wherein the complex network structure formation additive is B2O3, borax, boric acid, colemanite, P2O5, phospholite, Al(OH)3, aluminium phosphate, alkaline phosphate, calcium phosphate, or their mixtures. 본 발명은 SiO로 이루어진 망목구조의 Si 자리중 일부가 붕소(Boron), 인(Phosphorus) 및/또는 알루미늄(Aluminium) 원소로 대체된 액상규산나트륨에 관한 것으로, 본 발명에 따르는 액상규산나트륨은 기존의 액상규산나트륨 보다 내수성이 높아 접착제, 바인더, 시멘트, 복합재 등의 재료로 이용하기에 적합하다.