Spherical granules of porous silica or silicate, process for the production thereof, and applications thereof
US5342876A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 25, 1993 |
| Grant date | Aug 30, 1994 |
| Priority date | — |
| Expiry date | Jan 25, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/259
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
A porous and spherical silica is recovered in high yields from a neutralized product of an alkali silicate obtained by using an acrylamide type polymer as a coagulation growing agent, and the above silica is reacted as a precursor with a metal compound of the Group II of periodic table in an aqueous medium to obtain amorphous or fine, laminar and crystalline porous and spherical silica or silicate granules having a high degree of true sphericality, a symmetrical grain size distribution and a refractive index over a range of from 1.4 to 1.7. The porous and spherical granules have a primary grain diameter of 0.3 to 30 .mu.m as observed through an electron microscope, have an apparent specific gravity of from 0.05 to 0.5 g/ml, and are cheaply obtained in high yields, and can hence be used as a filler for various paints and resins. In particularly, the granules excellently disperse in the resins, have a refractive index close to those of the resins, are not crushed during the kneading with resins or extrusion, or do not damage the apparatus. The films obtained by using these granules exhibit very excellent transparency, anti-blocking property and scar resistance. Moreover, the porous a…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.