Process for the preparation of colloidal polymerized particles

A process for the preparation of colloidal polymerized particles (CPP) in the absence of emulsifier or other dispersing aid comprising the steps of:

• (a) forming a photopolymerizable aqueous colloidal dispersion (ACD) comprising:
• (i) at least one self-water dispersible compound (SW),
• (ii) at least one photoinitiator (PI), and
• (iii) optionally at least one photopolymerizable compound (B),
• (b) polymerizing the photopolymerizable aqueous colloidal dispersion (ACD) by photoinduced polymerization to form a dispersion of colloidal polymerized particles (DCPP), and
• (c) optionally isolating the particles obtained at step (b) from the aqueous phase to obtain isolated colloidal polymerized particles (ICPP),
• wherein the dispersion (ACD) comprises:
• (a) from 35 to 99.5 wt % of water calculated based on the total weight of the dispersion (ACD), and
• (b) from 0.5 to 65 wt % of dry content calculated based on the total weight of the dispersion (ACD),
• wherein the dry content comprises:
• (i) from 26 to 99.9 wt % of compound (SW),
• (ii) from 0.1 to 14 wt % of photoinitiator (PI), and
• (iii) from 0 to 60 wt % of compound (B),
• wherein the amounts of compound (SW), photoinitiator (PI) and compound (B) are calculated based on the dry content of the dispersion (ACD), and
• wherein
• the self-water dispersible compound (SW) comprises at least one photopolymerizable self-water dispersible compound (SW1),
• the self-water dispersible compound (SW) comprises at least one non photopolymerizable self-water dispersible compound (SW2) and at least one photopolymerizable compound (B) is present, or
• the self-water dispersible compound (SW) comprises at least one photopolymerizable self-water dispersible compound (SW1) and at least one non photopolymerizable self-water dispersible compound (SW2).