| 摘要 |
1314077 Propylene glycol alginate GRINDSTEDVAERKET AS 21 Sept 1970 [29 Sept 1969] 44837/70 Heading C3U Propylene glycol alginate is prepared by reacting alginic acid or partially-neutralized alginic acid with propylene oxide in the presence of a diluent in a reaction vessel 3, in which vessel the alginic acid starting material is retained by means 15 adapted to allow passage of liquids and gases, the propylene oxide and diluent passing through the retaining means until the reaction is complete. The alginic acid may be held stationary in the reaction vessel, in a basket of wire gauze or plastics netting (e.g. polypropylene) or held between perforated discs or wire netting (15) in the reactor. Alternatively the holding means may convey the alginic acid through a reactor. An imperforate screw conveyer in a perforated housing may be used, the diluent and propylene oxide passing through the housing, or a perforate screw in an imperforate housing, the diluent and propylene oxide passing countercurrent to the alginic acid. The reaction may be at 45-90‹ C. for 5 minutes to 5 hours. Preferably 1-25 moles propylene oxide is used per mole alginic acid. The diluent may be methanol, ethanol, isopropanol, acetone or methyl ethyl ketone. |
