The dispersing of pigments and fillers in organic and aqueous media, that is, the destruction of the agglomerates formed from the primary pigment and filler particles, is a work operation required in the production of paints and other pigmented coating agents, which constitutes a considerable cost factor owing to the necessary expenditure of time and energy. This dispersing operation is performed mechanically by means of various machines such as kneaders, cylinder mills and ball mills. In order to shorten this working operation, the pigments or fillers are treated with organic compounds which are intended to decrease the interfacial tension between the pigment or filler granule and the organic or aqueous medium and thus facilitate the dispersion of the pigment or filler. As far as possible, the action of these organic compounds should be limited only to improving dispersibility without attendant negative phenomena.
It is already known from U.S. Pat. No. 1,722,174 to treat inorganic pigments and fillers with stearic acid and resinic acid and ammonium soaps thereof in order to improve the ability of the pigments and fillers to disperse. According to data presented in French Pat. Specification No. 1,276,739, triethanolamine or salts thereof serve the same purpose. Furthermore, aliphatic amines have already been proposed as agents for improving the dispersing effect. When choosing the agents to be used, it has to be borne in mind that many additives are products which are not compatible with lacquer and which, in addition to the desired dispersing effect, also have many undesirable properties such as water-solubility and emulsifying power. Many of them also lead to attendant negative phenomena such as loss of luster of the finished coating and delayed drying during formation of the films.
USPTO Backgrounds
USPTO Backgrounds