Production of crosslinked microparticles for use in coating and molding compositions, and as rheological, reinforcing and-or flexibility agents comprises dispersion polymerization in non-aqueous medium, with no stabilizer used

摘要

Crosslinked microparticles are new and are obtained using new preparation method. Crosslinkable microparticles, of size 10-300 nm, are obtained by polymerization in dispersion (in non-aqueous medium which also is not a solvent of obtained polymer) of composition (1) comprising ethylenically unsaturated polymerizable compounds, including: (i) at least one monomer A containing one ethylenically unsaturated group, radical- polymerizable and ensuring auto-stabilization of formed microparticles without use of stabilizing polymeric agent before, during and after polymerization; (ii) at least one compound B containing at least two ethylenically unsaturated radically polymerizable groups; and optionally (iii) at least one compound C containing one ethylenically unsaturated radically polymerizable group different from that of A; and/or (iv) at least one compound D different from A, B and C, containing at least one ethylenically unsaturated radically polymerizable group and at least one second functional reactive group f1, different from ethylenically unsaturated group. The composition (1) preferably comprises (in mol.%): A 5-99, B 0.03-30, and optional C 0-80 and D 0-80, and wt. ratio of total of polymerizable compounds to non-aqueous solvent is 10/90-505/50, preferably 15/85-30/70. Independent claims are also included for (1) the process of preparation of crosslinked microparticles comprising one stage dispersion-polymerization of composition as claimed in non-aqueous medium comprising at least one solvent selected from 6-10C alkanes and/or 3-5C alkanols, preferably from hexanes, heptanes, cyclohexanes, octanes, nonanes, isopropanol, butanol, and pentanol, while the medium preferably consists of a mixture of n-heptane/isopropanol at wt. ratio 0-100 to 75/25, preferably 25/75 to 50/50; (2) composition of crosslinkable coating or molding or composites, comprising microparticles as described as reactive or non-reactive components, especially as rheology controlling agents, reinforcing and/or flexibility improving agents, or multifunctional crosslinking agents; and (3) use of composition as claimed or crosslinked microparticles as claimed in protective varnishes, paints, adhesives, inks, composites, molding powders or coatings, and molding products.