| 摘要 |
<p>A toilet cleaning block which releases a halogen disinfecting agent in a controlled, substantially constant rate for 2 to about 4 months of constant contact with water and is then completely dissolved in the water comprises an admixture of an agent which releases a halogen disinfecting agent when in contact with water, about 4 to 10% aluminum hydroxide based on the total weight of the block and up to about 1% by weight of a mold release lubricant, said admixture being in the form of a coherent solid resistant to internal water penetration having a density of 1.10 to 1.60 g/cc, a ratio of effective surface area to weight of about 1:1.05 to 1:1.25 and a crush fracturing strength of about 9-109 kg.</p> |
