| 摘要 |
1462377 Mineral paper filler suspensions ASSOCIATED PORTLAND CEMENT MFRS Ltd 18 June 1974 [18 June 1973] 28840/73 Headings C3H and C3P A method of producing a suspension of an acid reactive mineral filler for use in paper making comprises preparing an aqueous colloidal solution of one or more hydrophilic polymers acceptable in paper making, e.g. starch, modified starch, a natural starch containing material, casein, gluten, soya bean meal or protein, or polyvinylalcohol, incorporating an effective amount of a substance which results, upon a substantial increase in pH or pCa in the precipitation or gelation of substantially the whole of the polymer or polymers, e.g. aluminium sulphate or aluminium chloride, the colloidal solution being prepared under sufficiently acid conditions that at least some of the polymer is not precipitated or gelled, and then mixing the solution with an aqueous suspension of the filler, the concentration of said filler suspension being such that the filler concentration in the final suspension is at least half of the Daniel flow point concentration of the filler when determined in water containing sufficient surfactant to deflocculate the filler particles, and the polymer content is between 2 and 25% by weight of the filler content. |
