Synthesis of a particulate copolymer containing hydrophilic functionality

The present invention relates to a process for synthesizing a particulate copolymer comprising: providing a reaction mixture comprising a reaction medium, a polymerization stabilizer, a water-insoluble ethylenically unsaturated monomer and an ethylenically unsaturated monomer containing hydrophilic functionality, said reaction mixture having a viscosity value of at least 10 cps measured at 40° C., and polymerizing the water-insoluble ethylenically unsaturated monomer and the ethylenically unsaturated monomer containing hydrophilic functionality. The polymerization reaction is preferably conducted at a temperature lower than 100° C. and activated by a polymerization catalyst. The resulting particulate copolymer dispersion comprises copolymer particles showing a weight average diameter size in the range of microns and absence of defects, such as coagulant or agglomerates. The present invention also provides a dispersion of a particulate copolymer obtained by using the process described above and a photographic material comprising a support and at least one layer containing a particulate copolymer obtained by using the process described above. The photographic material presents improved physical and optical performance.