Process for the preparation of monodisperse polymer particles

A process for the preparation of monodisperse polymer particles having diameters of 1 to 6 μm which process comprises:

• forming an aqueous dispersion comprising monodisperse swellable seed particles and an anionic surfactant;
• contacting the aqueous dispersion of seed particles with a monomer selected from the group consisting of acrylic monomers, methacrylate monomers and vinyl monomers selected from the group consisting of styrene, divinylbenzene (DVB), ethyl vinyl benzene, vinyl pyridine, amino-styrene, methyl-styrene, dimethylstyrene, ethyl styrene, ethyl-methyl-styrene, p-chlorostyrene and 2,4-dichlorostyrene;
• allowing the monomer to diffuse into the seed particles to form an aqueous dispersion of swollen seed particles;
• and
• initiating polymerization of the monomer in the aqueous dispersion of swollen seed particles wherein the aqueous phase of the aqueous dispersion of swollen seed particles during polymerisation further contains as a steric stabilizer a polyvinylpyrrolidone;
• wherein the monodisperse swellable seed particles are monodisperse swellable seed oligomer particles.

A process for the preparation of monodisperse polymer particles having diameters of 1 to 6 μm which process comprises:

• forming an aqueous dispersion comprising monodisperse swellable seed particles, an anionic surfactant, and droplets comprising dioctyladipate;
• contacting the aqueous dispersion of seed particles with a monomer selected from the group consisting of acrylic monomers, methacrylate monomers and vinyl monomers selected from the group consisting of styrene, divinylbenzene (DVB), ethyl vinyl benzene, vinyl pyridine, amino-styrene, methyl-styrene, dimethylstyrene, ethyl styrene, ethyl-methyl-styrene, p-chlorostyrene and 2,4-dichlorostyrene;
• allowing the monomer to diffuse into the seed particles to form an aqueous dispersion of swollen seed particles;
• and
• initiating polymerization of the monomer in the aqueous dispersion of swollen seed particles wherein the aqueous phase of the aqueous dispersion of swollen seed particles during polymerisation further contains as a steric stabilizer a polyvinylpyrrolidone;
• wherein the monomer is an amino-functionalized monomer and a polymerization initiator is added after the seed particles have been swollen.

A process for the preparation of monodisperse polymer particles which process comprises:

• forming an aqueous dispersion comprising monodisperse swellable seed particles and an anionic surfactant;
• contacting the aqueous dispersion of seed particles with a monomer;
• allowing the monomer to diffuse into the seed particles to form an aqueous dispersion of swollen seed particles having a mode diameter in the range 5 to 200 μm;
• and
• initiating polymerization of the monomer in the aqueous dispersion of swollen seed particles, wherein the aqueous phase of the aqueous dispersion of swollen seed particles during polymerisation further contains as a steric stabilizer a water soluble cellulose ether of weight average molecular weight 10 to 100 kD.

A process for the preparation of monodisperse polymer particles having a diameter of at least 16 μm which process comprises:

• forming an aqueous dispersion comprising monodisperse swellable seed particles and an anionic surfactant;
• contacting the aqueous dispersion of seed particles with a monomer;
• allowing the monomer to diffuse into the seed particles to form an aqueous dispersion of swollen seed particles;
• and
• initiating polymerization of the monomer in the aqueous dispersion of swollen seed particles to produce a polymer, wherein the swollen seed particles contain at least two porogens, at least one of which is a solvent for the polymer produced and at least one of which is not a solvent for the polymer produced and at least one porogen is an aliphatic hydrocarbon having up to 12 carbon atoms.

A process for the preparation of monodisperse polymer particles which process comprises

• forming an aqueous dispersion comprising monodisperse swellable seed particles and an anionic surfactant;
• contacting the aqueous dispersion of seed particles with at least two monomers;
• allowing the monomers to diffuse into the seed particles to form an aqueous dispersion of swollen seed particles that swell at least 3.5 times in diameter;
• and
• imitating polymerization of the monomers in the aqueous dispersion of swollen seed particles to produce polymer particles;
• wherein at least two monomers are selected from the group consisting of acrylic, methacrylic acid and ester monomers and combinations of these monomers;
• and
• wherein the aqueous phase of the aqueous dispersion of swollen seed particles during polymerisation further contains a steric stabilizer.