| 摘要 |
Polyvinylbutyral (I) is produced by the reaction of polyvinyl alcohol (II) and butyraldehyde (III) in aq. soln., in the presence of an acid catalyst (IV) and an emulsifying agent which is an ethoxylated alkylphenol sulphate of formula (V): where n = 6 or 7. Specifically, the aq. soln., contg. 8-15 wt.% (II), is treated with (IV) and (V). (III) is then added at 5-12 deg. C in an amt. sufficient to react with 75-88% of the (II), and at such a rate that (I) is pptd. after 10-90 mins.. The resulting mixt. is stirred for above 30 mins. at 8-15 deg. C, then heated during 1.5-4 hrs. to 60-80 deg. C, and adjusted to pH 9-11 by addn. of a base. After maturing at this temp. for 5-10 mins., the pptd. (I) is sepd. and washed with water at 20 deg. C. |
