Development of zeolite for non-phosphated detergents in Japan

Under an increasing social demand for improving the so-called eutrophication problems in stagnant surface waters, the development of the zeolite for detergent-use was initiated according to the request of the detergent manufacturer. In a cooperative study with the zeolite supplier, the specifications of zeolite suitable to Japanese washing conditions were determined, and it was found that the acid clay method via activated silicic acid gel is suitable for the manufacturing process because of the economical viability and the quality of zeolite 4A obtained, which has small uniform-sized particles and high ion-exchange ability. By adding some improvements, specially prepared zeolite slurry was developed, which fulfills the requirements for the phosphate substitute builder. The related technology required for manufacturing of non-phosphated detergent was also developed, particularly on formulation, spray-dry processing and improvement of the final product's physical properties. Thus non-phosphated powder detergents of high-zeolite formulation were successfully introduced since 1980, and owing to their excellent performance properties, the switchover from phosphated detergents to them has almost been completed by last year in Japan.