Oil-in-water emulsions

Abstract

The invention relates to oil-in-water emulsions based on fatty alcohols and the use thereof as antifoams or deaerators for aqueous compositions. Such oil-in-water emulsions consist to at least 95% by weight of the following constituents: a) 50 to 80% by weight, in particular 55 to 75% by weight and specifically 60 to 70% by weight, based on the total weight of the oil phase, of at least one alkanol having at least 16 carbon atoms, in particular having 16 to 20 carbon atoms, where the fraction of alcohols having 16 to 18 carbon atoms constitutes at least 80% by weight, in particular 90% by weight, specifically 95% by weight or at least 99%, based on the total amount of component A, b) 1 to 10% by weight, in particular to 2 to 8% by weight, specifically 3 to 6% by weight, based on the total weight of the oil phase, of at least one further component B, which is selected from esters of C 12 -C 36 -alkanecarboxylic acids with polyglycerol and esters of C 12 -C 36 -alkanecarboxylic acids with C 12 -C 36 -alkanols, and mixtures thereof, c) 10 to 49% by weight, in particular 20 to 40% by weight, specifically 25 to 35% by weight, based on the total weight of the oil phase, of at least one further component C, which is selected from organic substances which are liquid at 50° C. and 1013 mbar, at atmospheric pressure have a boiling point above 200° C., and at 25° C. and 1013 mbar have a solubility in water of less than 0.1 g/l.

1 : An oil-in-water emulsion, comprising:
 an oil phase,   wherein the oil phase comprises at least 95% by weight of
 from 50 to 80% by weight, based on a total weight of the oil phase, of an alkanol having at least 16 carbon atoms, wherein a fraction of the alkanol having 16 to 18 carbon atoms comprises at least 80% by weight, based on a total amount of the alkanol; 
 from 1 to 10% by weight, based on the total weight of the oil phase, of at least one ester selected from the group consisting of a C 12 -C 36 -alkanecarboxylic acid with polyglycerol and of a C 12 -C 36 -alkanecarboxylic acid with a C 12 -C 36 -alkanol; and 
 from 10 to 49% by weight, based on the total weight of the oil phase, of an organic substance, wherein the organic substance is liquid at 50° C. and 1013 mbar, at atmospheric pressure the organic substance has a boiling point above 200° C., and at 25° C. and 1013 mbar the organic substance has a solubility in water of less than 0.1 g/l. 
   
     
     
         2 : The oil-in-water emulsion according to  claim 1 , wherein the alkanol consists essentially of unbranched alkanols. 
     
     
         3 : The oil-in-water emulsion according to  claim 1 , wherein the alkanol comprises at least 80% by weight of at least one alkanol is selected from the group consisting of palmityl alcohol and stearyl alcohol. 
     
     
         4 : The oil-in-water emulsion according to  claim 1 , wherein the at least one ester is at least 80% by weight from the ester comprising a C 18 -C 24 -alkanecarboxylic acid with polyglycerol. 
     
     
         5 : The oil-in-water emulsion according to  claim 4 , wherein polyglycerol-comprising ester is obtained by esterification of polyglycerol with behenic acid. 
     
     
         6 : The oil-in-water emulsion according to  claim 1 , wherein the organic substance comprises at least 80% by weight of an aliphatic hydrocarbon oil. 
     
     
         7 : The oil-in-water emulsion according to  claim 1 , wherein a solid content of the oil-in-water emulsion is of from 10 to 50%. 
     
     
         8 : The oil-in-water emulsion according to  claim 1 , wherein a weight-average particle size of the oil-in-water emulsion is of from 0.5 to 10 μm. 
     
     
         9 : A method for producing an antifoam or deaerator in an aqueous composition, comprising:
 producing the antifoam or deaerator with the oil-in-water emulsion according to  claim 1 .   
     
     
         10 : A method for producing a deaerator for an aqueous paper stock suspension, comprising:
 producing the deaerator for the aqueous paper stock suspension with the oil-in-water emulsion according to  claim 1 .   
     
     
         11 : A method for producing a deaerator in a headbox of papermaking comprising:
 producing the deaerator in the headbox of papermaking with the oil-in-water emulsion according to  claim 1 .   
     
     
         12 : A method of employing the oil-in-water emulsion according to  claim 8 , comprising:
 employing the oil-in-water emulsion at a temperature of from 20 to 50° C.   
     
     
         13 : The method according to  claim 9 , wherein the producing is producing at a temperature of from 20 to 50° C. 
     
     
         14 : The method according to  claim 10 , wherein the producing is producing at a temperature of from 20 to 50° C. 
     
     
         15 : The method according to  claim 11 , wherein the producing is producing at a temperature of from 20 to 50° C.