A process for delamination of layered silicates

Abstract

The invention relates to a process for delamination of a layered silicate in an aqueous medium, wherein in a first step a layered silicate having a layer charge Lc from ≥0.25 to ≤1.0 and a charge equivalent area As=47.6 Å2/(2Lc), is treated with a delamination agent, and in a second step the thus treated layered silicate is contacted with an aqueous medium, whereby the delamination agent is a compound having exactly one positively charged atom, the positively charged atom being selected from the group consisting of nitrogen and phosphorous; contains of functional groups selected from the group consisting of hydroxyl groups, ether groups, sulfonic acid ester groups and carboxylic acid ester groups, nf being a number from 1 to 10; comprises a total number of carbon atoms nc being from 2 to 20; has a ratio nc/(1+nf) from 1 to 5, wherein nc is the total number of carbon atoms of the delamination agent and nf is the total number of functional groups in the delamination agent as defined under ii.; and has a charge equivalent area Ad being from at least 0.90-fold to 3-fold of the charge equivalent area of the layered silicate As; and wherein the delamination agent is used to treat the layered silicate in an amount of at least equal to the cation exchange capacity of the layered silicate, with the proviso that nf≥2, if Lc≤0.6. The invention further relates to the thus produced delaminated layered silicates, their use in the production of composite and coating material and as a barrier material. Moreover, the invention relates to compositions containing the thus produced delaminated layered silicates.

Dependencies are inferred from the claim text.