Use of multi-block copolymers as thermo-thickeners
AssigneeRhodia Chimie
InventorsPascale Corpart, Herve Adam, Dominique Charmot
Life of this patent
Estimating the term…
Abstract
The invention concerns the use as thermothickeners of multi-block copolymers of general formula (I) or (II): ##STR1## wherein E designates a polyoxyalkylene sequence; A designates a water-soluble polymer sequence; X is a sulphur or oxygen atom; Y is an oxygen atom or an --N--R' group, R' being a linear or branched alkyl; R is a linear or branched alkyl, aralky or alkylaryl group; and n is such that the molecular mass of the multi-block copolymers Mp is greater than 250,000 g/mol.
Claims17
A method for maintaining or increasing the viscosity of an aqueous medium comprising the step of adding a thermally-induced thickening amount of a multiblock copolymer of general formula (I) or (II):
- ##STR7## wherein:
- E represents a polyoxyalkylene block, each alkylene chain member having not more than 6 carbon atoms;
- A represents a water-soluble polymer block prepared from at least one ethylenic monomer;
- X is a sulfur or oxygen atom;
- Y is an oxygen atom or a group --N--R',R' being:
- a linear or branched alkyl group, optionally comprising at least one hetero atom or a tertiary amine group, a C.sub.3 -C.sub.8 -cycloalkyl radical, an aryl, an aralkyl or an alkylaryl group;
- R is a linear or branched alkyl, a linear or branched aralkyl or a linear or branched alkylaryl group;
- and
- n is such that the molecular mass of the multiblock copolymers Mp is greater than 250,000 g/mol;
- and
- said viscosity being maintained or increased at a temperature below the critical temperature of the polyoxyalkylene blocks E.
Dependencies are inferred from the claim text.