US 4,301,034 A · Silica from single phase controlled hydrolysis of silicate ester

Abstract

A method comprising combining a silicate ester and water under hydrolysis conditions in the presence of a sufficient amount of solvent that the reaction mixture remains as a single phase, adding sufficient acid neutralizing agent to form a gel and separating solvent and water from the resulting silica. In a preferred embodiment, the ester and water are added to a very small amount of solvent, the addition of water being sufficiently slow that it is added at about the rate it is used up in the hydrolysis reaction. The resulting silica does not require the washing step to remove alkali metal ions since it is not made from sodium silicate, and it has large pore structure because it can be made in a relatively concentrated solution because of the use of only a minimum amount of solvent and also because the hydrolysis is carried out under conditions wherein only a single phase is produced. The resulting silica is suitable for chromatographic columns and fillers in rubber and plastics but is of primary utility as a base for a chromium oxide catalyst because of its simplicity in production and inherent large pore volume.

Claims49

Dependent claims

A method comprising:

combining a silicate ester and water under hydrolysis conditions in the presence of a sufficient amount of solvent such that the reaction mixture remains a single phase, after hydrolysis is essentially complete adding more water and maintaining the resulting composition at an elevated temperature to induce particle growth, thereafter adding sufficient acid neutralizing agent to form a gel, and separating water and solvent from the resulting silica.

Dependencies are inferred from the claim text.

Silica from single phase controlled hydrolysis of silicate ester

Life of this patent

Silica from single phase controlled hydrolysis of silicate ester

Life of this patent

Abstract

Claims49