Process and binder for the manufacture of ceramic shells for use as molds

摘要

PCT No. PCT/EP91/01217 Sec. 371 Date Jan. 17, 1992 Sec. 102(e) Date Jan. 17, 1992 PCT Filed Jun. 28, 1991 PCT Pub. No. WO92/12813 PCT Pub. Date Aug. 6, 1992.For the manufacture of quickly drying dip coats whose drying time is comparable to the drying time of shells produced on the basis of alcoholic binders, the process uses as a binder for the dip a dispersion of aqueous colloidal silica sol to which synthetic high polymers and/or an emulsion from the group of silicon-organic compounds is formed which after drying is impermeable to water but permeable to water vapor.