Patent ID: 6514429
Filing Date: 2003-02-04
Classification: C11D

Abstract:
Composition for use in a water tank characterized bya base composition (2; 3; 2â€²) in the form of a tablet (1; 1â€²), which evolves its function essentially following addition to a first filling of the water tank, and at least one particle (6; 6â€²; 6â€³) having at least one core (8; 8â€²; 8â€³) comprising at least one substance evolving its function substantially following an at least partial emptying of the first filling from the water tank and inflow of fresh water to the same and a covering (9; 9â€²; 9â€³) substantially surrounding the core or cores and comprising at least one compound, whose solubility increases with decreasing concentration of a specific ion in the surrounding medium, in which the at least one particle (6; 6â€²; 6â€³) is so placed in or on the tablet (1; 1â€²) that the surface of said particle is only partly in direct contact with the surface of the base composition (2; 3; 2â€²) surrounding the same and the concentration of the specific ion in the local environment of the particle is sufficiently high to prevent a significant dissolving of the covering or a significant detachment of the covering from the core or cores.