GB568388A - Improvements in aqueous dispersions containing synthetic resins - Google Patents

Abstract

An aqueous emulsion completely or substantially completely free from organic solvent contains an alkyd resin and a water-soluble dialkyl ether of dimethylol urea, water being in the continuous phase. Such emulsions may serve as a basis for water paints or enamels, as binders for cellulose, animal or mineral fibres, for sizing or coating paper or for preparing moulding powders or laminated materials. They may be used to obtain non-crease effects in textiles, for sizing or filling cloth or as a binder for pigment in textile printing processes. In all these processes final hardening of the resin components may be brought about by heat and/or acidic hardening agents. A suitable di-ether of methylol urea may be prepared by the method claimed in Specification 558,683. The ether may be partially resinified by a short heat treatment under acid conditions. To prepare the emulsions the partially resinified ether may be dissolved in water containing a wetting agent and a protective colloid, and the solution mixed with constant stirring with the molten alkyd resin. If desired, a blend of a solid alkyd resin and a partially resinified dialkyl ether of dimethylol urea may be melted and mixed with constant stirring to an aqueous solution of a wetting agent and a protective colloid. A suitable blend may be prepared as described in examples 1 and 2 of Specification 566,414. Alternatively the alkyd resin is melted and emulsified with an aqueous solution of a wetting agent and a protective colloid, and the diether of dimethylol urea is added either as a solid or as an aqueous solution. Suitable wetting agents are soluble soaps such as stearates or oleates of ammonia, triethanolamine, or soda and/or alkali salts of sulphonated fatty acids or fatty alcohols. They may be prepared in situ by adding the alkaline component to the dispersion medium and the acid component to the alkyd resin. Suitable protective colloids are bentonite, silica gel, water soluble cellulose ethers, casein, or gelatine. In Example 1 a castor oil modified glycerine phthalic anhydride resin is melted with a little stearic acid and added with stirring to a dispersion of bentonite in water which also contains the dimethyl ether of dimethylol urea and ammonia. (2) The molten alkyd resin is added with stirring to an aqueous solution containing a dimethyl ether of dimethylol urea, an emulsifying agent sold under the Registered Trade Mark "Belloid MN" and ammonia. (3) As resin blend prepared as in example 1 of Specification 566,414 is melted with stearic acid and added with stirring to an aqueous ammoniacal solution of Belloid MN. (4) The aqueous solution of ether is heated to 40 DEG C., added to a molten mixture of alkyd resin and stearic acid with stirring. Animal glue is used as the protective colloid. (5) An aqueous ammonical solution of animal glue is added with stirring to a molten mix of alkyd resin and stearic acid and an aqueous solution of partially resinified dimethyl ether of dimethylol urea is then added. Specification 527,520 also is referred to.