| 摘要 |
<p>A continuous process for manufacturing water-soluble hydroxyalkyl cellulose, and water-soluble mixed ethers based on hydroxyalkyl cellulose, comprising producing a slurry comprising (by weight) 1 part cellulose, 0.02 to 0.6 parts alkali metal hydroxide, 5 to 10 parts inert organic solvent, and 0.4 to 2.5 parts water; continuously feeding the slurry to a first elevated pressure reactor and mixing the slurry therein with at least one normally gaseous etherifying agent which has been liquified under pressure; maintaining the slurry at a temperature up to 40 DEG C., and a gauge pressure up to 3 bars, for 15 to 90 minutes, to give a degree of substitution from 0.2 to 1.0; continuously circulating the slurry in the first reactor in a loop through a homogenizing device to form a homogenized slurry; continuously feeding the homogenized slurry through a tubular reactor having a conveying device, an inlet, and first and second parts, and reacting the homogenized slurry in the tubular reactor for 70 to 180 minutes at a temperature from 30 DEG to 120 DEG C., under a gauge pressure of up to 10 bars, continuously transferring the reacted slurry into a cooling device; and subsequently purifying the etherified compounds; and apparatus for performing the process utilizing pressurized etherifying reactors and a heated tubular reactor.</p> |
