Preparation of systems of ground particulate material
US6087404A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 1, 1998 |
| Grant date | Jul 11, 2000 |
| Priority date | — |
| Expiry date | Jun 1, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S516/928
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
There is disclosed a process for preparing a concentrated aqueous suspension of a finely ground particular material, which process comprises (a) preparing an aqueous suspension comprising at least 20% by weight of the particulate material comprising calcium carbonate in coarse particular form; (b) grinding the suspension formed in step (a) in the presence of a polycarboxylate dispersing agent for the particular material in a grinding process where the pH is not less than 10 to produce an aqueous suspension wherein at least 90% by weight of the particles or the particulate material have an e.s.d. less than 2 .mu.m and 60% by weight have an e.s.d. less than 1 .mu.m; (c) adding an additive comprising an anionic polycarboxylate dispersing agent to the suspension of ground material formed in step (b). The process is characterized in that the aqueous suspension formed in step (c) has a pH which lies within the inclusive range 8.5 to 9.8 and in that, following addition of the anionic polycarboxylate dispersing agent in step (c), the suspension is not ground further. Using the method described, suspension can be prepared which are rheologically stable with time, and which contain a relativ…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.