METHOD FOR DRYING NONIONIC ALKYLENE OXIDE-TYPE WATER-SOLUBLERESIN, METHOD FOR PACKAGING IT, AND METHOD FOR TRANSPORTING IT

摘要

For efficiently drying a nonionic alkylene oxide-type water-soluble resin to make it have a low water content within a short period of time, the resin is put into a container, then the container is degassed to a vacuum degree of at most 150 mmHg, and while the vacuum degree is kept as such, a dry gas having a dew point not higher than the dew point DP calculated according to the following formula (1) is introduced into the container at an introduction rate not lower than the introduction rate V calculated according to the following formula (2). For efficiently removing minor volatiles from a nonionic alkylene oxide-type water-soluble resin, used is a drying device that comprises an evaporation tank where the resin is put in and a stirring blade which revolves inside the evaporation tank as it rotates on its own axis. For protecting a dried nonionic alkylene oxide-type water-soluble resin from water,a preferred method comprises introducing a dry gas into a packing line that runs from a dry resin-feeding zone to a packaging container, thereby introducing the dry gas into the empty packaging container just before packed with the resin along with purging away the air initially existing in the container, then packing the packaging container with the resin, and sealing up the opening of the packaging container. A method of transporting a nonionic alkylene oxide-type water-soluble resin that ensures good processability of the resin and prevents the resin from being deteriorated comprises controlling the resin so as to have a solvent content of from 0.001 to 50 % by weight and a viscosity at 40.degree.C of at most 10,000 Pa.cndot.sec, and loading it into a transportation container equipped with a temperature control capability and/or unloading it out of the transportation container by the use of a pump. DP (.degree.C) = -21.6 log10 Vac ~~~(1), V (L/min) - 0.5 .times.[Vac/(273 + T)] .times. V0 ~(2), wherein Vac indicates the vacuum degree (mm Hg), T indicates the temperature inside the container (.degree.C), V0 indicates the volume of the container (ml).