A PROCESS FOR DELAMINATION OF LAYERED SILICATES

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 / (2 Lc), 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 nf 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. L'invention concerne un procédé de délaminage d'un silicate en couches dans un milieu aqueux, dans lequel, dans une première étape, un silicate en couches ayant une charge de couche Lc de ≥ 0,25 à ≤ 1,0 et une surface équivalente de charge As = 47.6 Å2 / (2 Lc), est traité avec un agent de délaminage, et dans une seconde étape, le silicate en couches ainsi traité est mis en contact avec un milieu aqueux, l'agent de délaminage étant un composé ayant exactement un atome chargé positivement, l'atome chargé positivement étant choisi dans le groupe constitué par l'azote et le phosphore; contenant nf groupes fonctionnels choisis dans le groupe constitué par des groupes hydroxyle, des groupes éther, des groupes ester d'acide sulfonique et des groupes ester d'acide carboxylique, nf étant un nombre de 1 à 10; comprenant un nombre total d'atomes de carbone nc allant d