Ripening agent for acrylic plastisols

Claim 1

A photosensitive thermally coalescible acrylic resin plastisol or organosol dispersion which comprises particles having a mean diameter in the range of 0.1 to 20 μm of a solid, single-phase, finely divided random acrylic polymer of copolymer containing at least 50% by weight of acrylic units and having an inherent viscosity in the range of 0.1 to 1.5, dispersed in a liquid medium that comprises (a) a liquid compatible with the single-phase particles that is nonvolatile at room temperature, has no substantial solvent activity for the polymer at room temperature, and is not a monomer that has the same chemical structure as a monomer of the polymer or copolymer, and (b) 0.2 to 40% by volume of the total volume of the dispersion of a liquid that is volatile at room temperature and has substantial solvent or swelling action on the polymer at said temperature, the liquid medium of said dispersion containing a nonvolatile photopolymerizable ethylenically unsaturated monomeric compound which is not a monomer that has the same chemical structure as a monomer of the polymer or copolymer and at least one photoinitiator, the solid polymer or copolymer particles/nonvolatile liquid ratio being 40/60 to 100/0, and the photopolymerizable ethylenically unsaturated monomeric compound being present in an amount of 10 to 150% by weight based on the weight of the solid particles.