CONTINUOUS PROCESS AND APPARATUS FOR PRODUCING WATER-SOLUBLE HYDROXYALKYL CELLULOSE AND RELATED ETHERS

摘要

Disclosed is a continuous process for the manufacture of water-soluble hydroxyalkyl cellulose, and water-soluble mixed ethers based on hydroxyalkyl cellulose, comprising the steps of producing an initial slurry comprising 1 part by weight of cellulose, about 0.02 to 0.6 parts by weight of an alkali metal hydroxide, about 5 to 10 parts by weight of an inert organic solvent, and about 0.4 to 2.5 parts by weight of water; continuously feeding the initial slurry into a first apparatus suitable for operation at elevated pressure, and mixing the initial slurry therein with at least one etherifying agent which is gaseous at atmospheric pressure and at room temperature, and which has been liquefied under pressure; maintaining the slurry in the first apparatus at a temperature of up to about 40.degree.C, and under a gauge pressure of up to about 3 bars, for a residence time of from about 15 to 90 minutes, to give a degree of substitution in the range of from about 0.2 to about 1.0, continuously circulating the slurry in the first apparatus in a loop through a homogenizing device, to form homogenized slurry; continuously feeding the homogenized slurry through a tubular reactor having a conveying device, an inlet, a first part, and a second part, and reacting said homogenized slurry in the reactor for a residence time of about 70 to 180 minutes at a temperature of from about 30.degree. to 120.degree.C, under a gauge pressure of up to about 10 bars; continuously transferring the reacted slurry from the reactor into a cooling devices and subsequently purifying the desired etherified compounds. Also disclosed is an apparatus for performing the process, utilizing pressurized etherifying reactors and a heated tubular reactor.