| 摘要 |
Thioxotropic Fuller's earth clay minerals which are structurally double silica chains linked together through oxygen to form double-ribbed sheets held by aluminum and/or magnesium in octahedral coordination in an amphibole chain are vacuum dried and admixed with a stabilizing fluid, e.g., silicone fluid, to result in new, low moisture content thixotropic agents. The mineral products thus produced are superior thixotropes when compounded in plastics such as plastisols, adhesive sealants, coatings and other organic binder systems which are heat set or heat cured or moisture cured, and compliance coatings. The methods involve reducing the moisture content of Fuller's earth clay, e.g., attapulgite, by (1) heating it under vacuum at an elevated temperature, preferably between 100 DEG C. and 300 DEG C., or (2) heating it at an elevated temperature, preferably between 100 DEG C. and 350 DEG C., and adding a stabilizing fluid, or (3) heating it under vacuum at an elevated temperature, preferably below 300 DEG C. and adding a stabilizing fluid, to preserve its low moisture properties.
|
