Novel fluorocopolymers for the hydrophobic and oleophobic treatment of various substrates

Fluorocopolymers capable of being obtained by polymerization of a monomer mixture comprising by weight:

• (a) from 50 to 92%, preferably from 70 to 90%, of one or more polyfluoromonomers of general formula:
• 7
• in which:
• Rf represents a perfluorinated radical having a straight or branched chain, containing 2 to 20 carbon atoms, preferably 4 to 16 carbon atoms,
• B represents a divalent linking which is linked to O by a carbon atom and which may comprise one or more oxygen, sulphur and/or nitrogen atoms,
• one of the symbols R represents a hydrogen atom and the other a hydrogen atom or an alkyl radical containing 1 to 4 carbon atoms;
• (b) from 1 to 25%, preferably from 8 to 18%, of one or more monomers of general formula:
• 8
• in which:
• B′ represents a linear or branched alkylene radical containing 1 to 4 carbon atoms,
• R′ represents a hydrogen atom or an alkyl radical containing 1 to 4 carbon atoms,
• the symbols R1 and R2, which are identical or different, each represent a hydrogen atom, a linear or branched alkyl radical containing 1 to 18 carbon atoms or a hydroxyethyl or benzyl radical, or R1 and R2 together with the nitrogen atom to which they are linked form a morpholino, piperidino or pyrrolidin-1-yl radical;
• (c) from 0.5 to 20% preferably from 1 to 10%, of an anionic monomer or a monomer which is potentially anionic by varying the pH (III), such as alkene carboxylic acids, monoolefinic derivatives of sulphonic acid, and their salts of alkali or alkaline-earth metals;
• (d) from 2 to 10% of a vinyl derivative of general formula:
• R″—CH=CH2 (IV)
• in which R″ may be an alkyl carboxylate or alkyl ether group containing from 1 to 18 carbon atoms;
• (e) from 0 to 10%, preferably from 0 to 8%, of any monomer other than the monomers of formulae I, II, III and IV;
• the said copolymerization comprising:
• the dissolving of the monomers in a distillable organic solvent;
• and then
• the diluting of the reaction mixture with water in the presence of a mineral or organic acid in order to salify the macromolecules.