| 摘要 |
Alkaline earth metal carbonate exhibiting a resistance to acids expressed as pH of less than 7 measured after suspending 1.0 g of the particles in a mixture made of 20 ml of toluene and 80 ml of an aqueous phase consisting of deionized water, 11.76 g/L of citric acid monohydrate, 2.57 g/L of NaCl and 0.068 mol/L of NaOH, after 35 minutes of stirring at 25°C and at 1 000 rpm,, or expressed as a moisture pick-up lower than or equal to 2 g water/kg of calcium carbonate after one week of storage at 22°C and 50 % relative humidity, or as a Different ial Scanning Calorimetry (DSC) spectrum showing at least one peak between 170 and 190°C when measured at a heating rate of 10°C/min under nitrogen atmosphere from 25 to 250°C in open cells. Process for the preparation of said particles, compositions containing said particles and the use thereof. |
