Patent · US Expired

Production of high silica glass microspheres

US4904293A · kind A · utility

15Cited by
4References
22Claims
0Family size

Assignee

Inventors

Key dates

Filing dateAug 2, 1988
Grant dateFeb 27, 1990
Priority date
Expiry dateAug 2, 2008

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC03C21/008
  • WIPO fieldMaterials, metallurgy
  • WIPO sectorChemistry

Abstract

Production of microspheres having a very high silica content produced from a starting glass whose silica content is less than 80% by weight, with the remainder being essentially made up of boron oxide and one or more alkaline oxide(s). This starting glass is reduced into fine particles by grinding, optionally mixed with a fluidizing agent, and then passed through the flame of a burner at a temperature at least equal to 1500.degree. C. to form molten hollow microspheres which are suddenly cooled to form solid hollow microspheres. The microspheres produced thereby are recovered and contacted with a dealkalization agent to increase the silica content thereof to at least 92%.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.