| 摘要 |
<p>A coating base for pharmaceutical film, which comprises lowly polymerized cellulose ether, preferably a highly white one prepared by causticizing a pulp with a copper number of 0.4 g or less, adding an etherifying agent thereto to form a highly polymerized cellulose ether, purifying the ether with hot water, drying by heat, grinding, and depolymerizing. It is preferable that the lowly polymerized cellulose ether be one having a viscosity of 20 cSt or less as a 2 % aqueous solution thereof at 20 °C. The ether is selected among methylcellulose, hydroxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, and hydroxybutylmethylcellulose. The highly white, lowly polymerized cellulose ether is obtained by drying the highly polymerized cellulose ether kept at 40 to 80 °C in an inert gas or oxygen-deficient atmosphere kept at 100 °C or below into a moisture content of 1 to 5 wt% and grinding the dried ether on an impact grinder within one min.</p> |
