| abstract |
Parent patent describes a dishwashing compsn. based on alkali silicates and/or carbonates and/or hydroxides (I) and finely-divided, water-insoluble cpds. of formula (Alk2O)x. Me2O3. (SiO2)y (II) (where Alk is an alkali ion exchangeable with Ca; x = 0.7-1.5; Me is B or Al and y is 0.8-6, pref. 1-3-4) to bond the water-hardening components of the water and which had a Ca-bonding capacity of 100-200 mg CaO/g anhydrous active substance as well as the usual other additives. In this addn. the compsn. contains 0.5-5 wt. % (1-3) of cpds. having di-/tri-valent cations (as their oxides) which are either sparingly water-soluble themselves or form sparingly water-soluble cpds. with the compsn's components without, however, using >20% of the Al silicate's original Ca-bonding capacity. Corrosion of the articles to be cleaned is reduced without significantly increasing the water's hardness. |