Procedure for manufacture of aqueous suspensions of calcium carbonate and suspensions obtained, and their uses

摘要

The object of the invention consist of a process for the manufacture of aqueous suspensions of calcium carbonate using an acrylic polymer with an average by weight molecular weight of between 8,000 g/mole and 15,000 g/mole and a molar content of less than 20% of polymeric chains of molecular weight less than 3,000 g/mole. It also concerns the aqueous suspensions obtained, possibly dried, and their uses in the paper, paint, plastics and mastics industry.

主权项

1. A product prepared from the process comprising the following stages:
a) pre-grinding calcium carbonate under dry and/or wet conditions to obtain an average diameter of 0.5 to 500 μm (d50), with or without a dispersing agent, b) forming an aqueous suspension of the product derived from stage a) having a dry calcium carbonate content of between 10% and 80%, c) grinding the suspension derived from stage b) in the presence of a homopolymer and/or of a copolymer of (meth)acrylic acid having (i) an average molecular weight of between 8,000 g/mole and 15,000 g/mole, and (ii) less than 20% by mole of polymeric chains having a molecular weight less than 3,000 g/mole, d) optionally concentrating the aqueous suspension obtained in stage c), e) optionally adding a dispersing agent to the aqueous suspension during or after stage d), f) optionally drying the product obtained in stage c) or d) or e).