Patent GB-897993-A (GB)
Title: Thixotropic agents and compositions containing them
IPC: C09D7/00
Filed: 1958-07-23
Abstract: A product suitable for addition to coating compositions to which it imparts thixotropic properties is obtained by reacting an alkylene diamine, suitably at 75 DEG -300 DEG C., with a bodied glyceride oil of a polyunsaturated fatty acid, and removing substantially all the glycerine formed in the reaction, e.g. by vacuum stripping.  Suitable diamines are 1:2- and 1:3-diaminopropane, 1:4-diaminobutane, 1:6-diaminohexane, and especially ethylene diamine.  The bodied oil is suitably a vegetable drying oil such as chinawood, linseed, or dehydrated castor oil, a vegetable semi-drying oil such as soyabean oil, or a marine oil; when chinawood oil is used the optimum reaction temperature is 170 DEG C., whilst for dehydrated castor oil or soyabean oil it is 200 DEG C.  The product may be employed in amounts of about 1-10%, preferably 4-8% (based on non-volatile content) in coating compositions, e.g. in varnish bases.  In Example IX, 1 part of the product obtained by reacting bodied soyabean oil with 1:6-diaminohexane is mixed with 12 parts of alkali refined linseed oil.  Reference has been directed by the Comptroller to Specification 836,218.ALSO:A product which imparts thixotropic properties to coating compositions containing alkyd resins or oil-modified alkyd resins is obtained by reacting an alkylene diamine, suitably at 75 DEG -300 DEG C., with a bodied glyceride oil of a polyunsaturated fatty acid, and removing substantially all the glycerine formed in the reaction, e.g. by vacuum stripping.  Suitable diamines are 1:2- and 1:3-diaminopropane, 1:4-diaminobutane, 1:6-diaminohexane, and especially ethylene diamine.  The bodied oil is suitably a vegetable drying oil such as chinawood, linseed, or dehydrated castor oil, a vegetable semi-drying oil such as soyabean oil, or a marine oil; when chinawood oil is used the optimum reaction temperature is 170 DEG C., whilst for soyabean or dehydrated castor oil it is 200 DEG C.  In the coating compositions, the product is generally employed in amounts of 1-10%, preferably 4-8%, based on the non-volatile content, and if preferred the product may be formed by reaction in situ in the vehicle to which thixotropy is to be imparted.  In Examples, VI-VIII, the respective reaction products of bodied soyabean oil, dehydrated castor oil and chinawood oil are mixed with an oil modified alkyd resin; in Example X, a soyabean oil modified alkyd resin is mixed with the reaction product of bodied soyabean oil and ethylene diamine; in Example XI, a linseed oil modified alkyd resin is mixed with the reaction product of chinawood oil and ethylene diamine; in Example XII, an oil modified flat wall alkyd is mixed with the reaction product of bodied soyabean oil and ethylene diamine and with odourless mineral spirits; in Example XIII, the mixture of Example XII is mixed with composite TiO2-CaCO3, whiting, mineral spirits, lead and cobalt naphthenate, and an antiskinning agent to provide a paint; in Example XIV, the mixture of Example XII is mixed with rutile, whiting, diatomaceous silica, mineral spirits, lead and cobalt naphthenates and an antiskinning agent to provide a paint; in Example XV, a soyabean oil modified alkyd resin is mixed with the reaction product of bodied soyabean oil and ethylene diamine and with odourless mineral spirits; in Example XVI, the mixture of Example XV is mixed with the same paint-forming materials as are used in Example XIII.  Reference has been directed by the Comptroller to Specification 836,218.