Abstract: According to the present invention a dispersant is provided for stabilizing dispersions of metal oxides and/or carbon black in water in the presence of a hydrophilic binder. Said dispersant is a block-copolymer comprising at least one block of an ammonium group containing (meth)acrylate.

Abstract: According to the present invention a dispersant is provided for stabilizing dispersions of metal oxides and/or carbon black in water in the presence of a hydrophilic binder. Said dispersant is a block-copolymer comprising at least one block of an ammonium group containing (meth)acrylate.

Abstract: Process for the preparation of polymers by anionic (co)polymerization of ethylenically unsaturated organic monomers in the presence of an arylmethide initiator of the following general structure: ##STR1## wherein: X.sup.+ represents a cation;Y and Z (same or different) represent a hydrogen atom or an alkyl group;Ar represents a condensed aromatic group, including a substituted condensed aromatic group.

Abstract: A surface-active block copolymer which comprises chemically linked polymeric blocks (A) and (B), block (A) of said copolymer consisting of at least one homo- or copolymerized non-polar alpha,beta-ethylenically unsaturated monomer and block (B) of said copolymer is derived by polymerizing an alpha-beta ethylenically unsaturated monomer containing an epoxy group and transforming the epoxy group into an hydroxy-substituted ionic group, preferably an anionic group. These block copolymers are used as dispersing agents in aqueous dispersions, including polymeric latex dispersions, and as plasticizing agent in hydrophilic colloid layers, including colloid layers containing a dispersed light-sensitive silver halide emulsion or other auxiliary substances for photographic materials.

Abstract: This invention relates to a process for polymerizing acrylic monomers and possibly non-acrylic co-monomers by means of polymerization-initiating agents of the formula:R--M (I)in which M represents a metal selected among the alkaline and alkaline-earth metals and R represents an alkyl radical, which may have a straight or branched chain and contains 2 to 6 carbon atoms, or an aryl radical.The polymerization or copolymerization is effected in the presence of an additive consisting of a salt of an alkaline or alkaline-earth metal and of a mineral acid, such as lithium chloride.

Abstract: The invention relates to a process for preparing products containing polymer chains in which a linear prepolymer or polymer contains at least one free acid group at each chain and is reacted with an alkoxide of a metal having a valence of more than 2, such as zirconium, titanium or cerium, possibly in the presence of a non polar solvent, the alkoxide of the metal having a valence of more than 2 being used in such a quantity that the alkoxide functions are in excess with respect to the stoichiometric amount of the acid functions carried by said linear prepolymer or polymer, the reaction mixture being stirred in the presence of humidity until a product is obtained wherein the hydrogen atoms of the free acid end groups of the prepolymer or polymer are substituted by an atom of the metal (M) which is itself linked to another atom of said metal by M-O-M linkages. The invention relates also to the products containing a prepolymer or polymer .alpha.,.omega.