Nova Patents
EP0333984A2

Process for the preparation of polyglycerins.

Abstract

The invention relates to a process for producing polyglycerols which are low in cyclic components, by reacting glycerol with chlorohydrins at elevated temperature. In this case, glycerol or diglycerol or a higher polyglycerol with epichlorohydrin (instead of chlorohydrin) at certain temperatures and certain molar ratios of glycerol or diglycerol or higher polyglycerol converted to epichlorohydrin and the resulting, non-separated reaction mixture at a temperature of 50 ° C to 120 ° C , preferably from 80 ° C to 95 ° C, added in accordance with the content of the reaction mixture of organically bound chlorine, an alkaline, preferably aqueous solution. The reaction mixture is desalted by adding water through one or more cation and subsequent anion exchangers, dehydrated by distillation and the Glycerinpolyglyceringemisch obtained by fractional distillation into glycerol, diglycerol and higher polyglycerols.

Term

Term ended

Projected expiry passed 17 January 2009, 17.7 years ago.

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16 claims: 14 independent, 2 dependent

  1. c-de-0001
    1. A method for producing polyglycerols which are low in cyclic components, by reacting glycerol with chlorohydrins at elevated temperature, characterized in that glycerol or diglycerol or a higher polyglycerol with epichlorohydrin (instead of chlorohydrin) at temperatures of 90 to 170 ° C, preferably from 120 ° C to 150 ° C, in a molar ratio of glycerol or diglycerol or higher polyglycerol to epichlorohydrin of 5:3 is reacted and the resulting, non-separated reaction mixture at a temperature of 50 ° C to 120 °: 1 to 1 C., preferably from 8o ° C to 95 ° C, corresponding to the content of the reaction mixture of organically bound chlorine an alkaline reacting medium, preferably an alkaline aqueous solution is added, the reaction mixture by adding water through one or more cation exchanger and subsequently using anion exchangers desalted, dehydrated by distillation and the Glycerinpolyglyceringemisch is separated by fractional distillation into glycerol, diglycerol and higher polyglycerols.
  2. c-de-0004
    4. The method according to one or more of claims 1 to 3, characterized in that the alkaline-reacting alkali carbonate solution to the non-separated reaction mixture from the reaction of epichlorohydrin with glycerol, diglycerol or a higher polyglycerol in an equivalent ratio of alkali carbonate to the content of organically bound chlorine from 1:1 to 1.2: 1, preferably 1.05: 1 to 1.1: 1, is added.
  3. c-de-0005
    5. The method according to one or more of claims 1 to 4, characterized in that the reaction mixture by the addition of the akalisch reacting aqueous solution to a pH range From 7.0 to 11.5, preferably 8 to 11, is set.
  4. c-de-0006
    6. The method according to one or more of claims 1 to 5, characterized in that the reaction mixture cooled to room temperature and separated off the main quantity of the precipitated salt, preferably is filtered off.
  5. c-de-0007
    7. The method according to one or more of claims 1 to 6, characterized in that the molar ratio of glycerol to epichlorohydrin of increasing the Diglycerinanteiles, 4:1 to 2.5: 1 is.
  6. c-de-0008
    8. The method according to one or more of claims 1 to 6, characterized in that the molar ratio of glycerol and / or diglycerol to epichlorohydrin to increase the incidental diglycerol Polyglycerinanteiles 2.49:1 to 0.5: 1, preferably 1.8: 1 to 0.4: 1, is.
  7. c-de-0009
    9. The method according to one or more of claims 1 to 8, characterized in that the regeneration of the cation exchange medium in the cation exchangers takes place by means of a direct current or composite-direct current regeneration.
  8. c-de-0010
    10. The method according to one or more of claims 1 to 8, characterized in that washed after regeneration the salts, according Beendi of Auswaschvorganges supply the polyglycerol, preferably diglycerol solution is passed through the ion exchanger and the anion exchanger leaving polyglycerol, preferably diglycerol solution until a polyglycerol content, preferably diglycerol content of 20 wt .-%, preferably until a polyglycerol content, preferably diglycerol content of 15 wt .-%, and returned to produce the 70-40 wt .-% strength by weight, preferably 60 -. 50% strength by weight, polyglycerol, preferably diglycerol starting solution is used concomitantly.
  9. c-de-0011
    11. The method according to one or more of claims 1 to 10, characterized in that the passage of the polyglycerol-containing, preferably diglycerol solution through the ion exchanger is effected under excess pressure.
  10. c-de-0012
    12. The method according to one or more of claims 1 to 11, characterized in that the polyglycerol-containing, preferably diglycerol solution under a pressure of 1.1 to 10 bar, preferably 2 - 6 bar, by several cation exchanger and at least one anion exchanger is passed one or.
  11. c-de-0013
    13. The method according to one or more of claims 1 to 12, characterized in that the ion exchanger mass of the cation exchanger and / or anion exchanger of a screen plate, perforated plate or arranged displaced in the height direction of the ion exchanger, covering the exchanger mass and a uniform liquid passage permitting device and / or an inert molding compound and / or elastic plastic material is covered.
  12. c-de-0014
    14. The method according to one or more of claims 1 to 13, characterized in that the anion exchange and used Kationenaustauschermassen temperature resistant to about 80 ° C, preferably to about 100 ° C, are.
  13. c-de-0015
    15. The method according to one or more of claims 1 to 14, characterized in that the strong acid cation exchange medium and the weakly basic anion exchange material having an inner surface (measured by the BET method) of more than 25 m² /, preferably 50 to 100 m² / g, exhibit.
  14. c-de-0016
    16. The method according to one or more of claims 1 to 15, characterized in that the polygly cerinhaltige, preferably diglycerol solution at a flow rate of 0.5 m / h to 15 m / h, preferably 1 m / h to 5 m / h, is passed through the ion exchanger.
Independent claims14