| 摘要 |
1,155,500. Drying cellulose esters. EASTMAN KODAK CO. 24 May, 1968 [29 May, 1967], No. 24868/68. Heading C3A. A wet cellulose ester having an I.V. of 0À01- 0À6 (measured in 9 : 1 v/v. methylene chloride : methanol at 25‹ C.) is subjected to drying conditions while above its melting point until a clear, brilliant melt is formed, and the melt is then cooled so that it solidifies within 3 minutes, preferably within 30 seconds. Many esters are listed, e.g. butyrate, acetate, acetate-butyrate, acetate-phthalate and propionate. The drying temperature is better not more than 30‹ C. above the ester m.pt., and the cooling is taken rapidly to preferably at least 40‹ C. below the m.pt. As coolants, solid CO 2 , cold air and water are listed. |
