Patent GB-748011-A (GB)
Title: Process for rapidly increasing the viscosity of a hydroxylated fatty glyceride oil
Filed: 1950-07-17
Abstract: The viscosity of a hydroxylated fatty glyceride oil is increased by heating it with an ester of a polysilicic acid or a mixture containing such an ester or esters.  The hydroxylated fatty glyceride oil may be natural or synthetic and specific examples are castor oil, partially dehydrated castor oil, and blown vegetable oils (especially those blown with moist air) such as blown castor oil and blown linseed oil.  The ester of a polysilicic acid may be prepared by the partial ydrolysis of alkyl silicates in the presence of a condensing agent such as a strong acid, particularly hydrochloric acid.  The product thus obtained may be freed from the condensing agent before reacting with the hydroxylated oil, or may be used directly.  The material known as "English ethyl silicate," produced by the reaction of silicon tetrachloride with industrial alcohol, and consisting of tetraethoxy silicane, hexa-ethoxy silicane (EtO)3 Si-O-Si(OEt)3, and esters of higher polysilicic acids, together with some ethyl alcohol, may be employed as the ester of polysilicic acid.  The reaction between the hydroxylated oil and the ester of a polysilicic acid may be conducted in an open or closed vessel, with or without refluxing, and under vacuum or under pressure; if desired, a solvent such as ethyl alcohol, or a mixture of ethyl alcohol and aromatic hydrocarbons such as benzene or toluene, may be present during the reaction.  In examples, castor oil, partially dehydrated castor oil or blown linseed oil is heated with English ethyl silicate.ALSO:The viscosity of a hydroxylated fatty glyceride oil is increased by heating it with an ester of a polysilicic acid or a mixture containing such an ester or esters.  The hydroxylated fatty glyceride oil may be natural or synthetic and specific examples are castor oil, partially dehydrated castor oil, and blown vegetable oils (especially those blown with moisture) such as blown castor oil and blown linseed oil.  The ester of a polysilicic acid may be prepared by the partial hydrolysis of alkyl silicates in the presence of a condensing agent such as a strong acid, particularly hydrochloric acid.  The product thus obtained may be freed from the condensing agent before reacting with the hydroxylated oil, or may be used directly.  The material known as "English ethyl silicate," produced by the reaction of silicon tetrachloride with industrial alcohol, and consisting of tetraethoxy silicane, hexa-ethoxy silicane (Eto)3 Si-O-Si (OEt)3, and esters of higher polysilicic acids, together with some ethyl alcohol, may be employed as the ester of polysilicic acid.  The reaction between the hydroxylated oil and the ester of a polysilicic acid may be conducted in an open or closed vessel, with or without refluxing, and under vacuum or under pressure; if desired, a solvent such as ethyl alcohol, or a mixture of ethyl alcohol and aromatic hydrocarbons such as benzene or toluene, may be present during the reaction.  In examples, castor oil, partially dehydrated castor oil or blown linseed oil is heated with English ethyl silicate.  The products of some of the examples are stand oils having drying properties.