Abstract: Aqueous suspensions of silicate shell microcapsules having a volume fraction of microcapsules of at least 30% that are gel free at 50° C. for at least one month and processes for obtaining them are disclosed. A process for improving the stability of an aqueous suspension of silicate shell microcapsules is disclosed which involves reducing non-volatile solid content of the continuous phase of the aqueous suspension of the silicate shell microcapsules to less than 0.3 weight percent. A process is also disclosed for improving the stability of an aqueous suspension of silicate shell microcapsules by adding a colloidal silicate sequestering agent to an aqueous suspension of silicate shell microcapsules and colloidal silicate particles.

Abstract: A process is disclosed for preparing microcapsules having a shell thickness of at least 18 nanometers by polymerizing a tetraalkoxysilane at the oil/water interface of an emulsion containing 0.1 to 0.3 weight percent of a cationic surfactant. The microcapsules are useful to prepare encapsulated sunscreens having sufficient robustness to prevent leakage of the encapsulated sunscreen in a formulated composition.