| 摘要 |
In mfre. of a Cr-oxide/SiO2 polymsn. catalyst, comprising reacting an aq. alkali metal-silicate soln. with an aq. acid to form a hydrogel, ageing the hydrogel, washing the same with an aq. soln. of an ammonium-salt, removing the water to form a xerogel, depositing Cr-oxide on the xerogel, and activating the resulting compsn. the ammonium-salt used to wash the hydrogel is an NH4NO3 soln. Prods. of superior quality are obtd. as shown by the MFI of the polymers prepd., using the claimed catalysts. Used in polymsn. of olefins. |
