Abstract: A process for the preparation of monodisperse polymer particles which are formed by contacting monomers with aqueous dispersions comprising monodisperse swellable seed polymers/oligomers, and initiating polymerization in the presence of a steric stabilizer. The resulting swollen seed particles are characterized by the particle mode diameter.

Abstract: A process for the preparation of monodisperse polymer particles which are formed by contacting monomers with aqueous dispersions comprising monodisperse swellable seed polymers/oligomers, and initiating polymerization in the presence of a steric stabilizer. The resulting swollen seed particles are characterized by the particle mode diameter.

Abstract: A process for the preparation of monodisperse polymer particles which are formed by contacting monomers with aqueous dispersions comprising monodisperse swellable seed polymers/oligomers, and initiating polymerization in the presence of a steric stabilizer. The resulting swollen seed particles are characterized by the particle mode diameter.

Abstract: A process for the preparation of monodisperse polymer particles which are formed by contacting monomers with aqueous dispersions comprising monodisperse swellable seed polymers/oligomers, and initiating polymerization in the presence of a steric stabilizer. The resulting swollen seed particles are characterized by the particle mode diameter.

Abstract: A process for the preparation of monodisperse polymer particles which are formed by contacting monomers with aqueous dispersions comprising monodisperse swellable seed polymers/oligomers, and initiating polymerization in the presence of a steric stabilizer. The resulting swollen seed particles are characterized by the particle mode diameter.

Abstract: A process for the preparation of monodisperse polymer particles which are formed by contacting monomers with aqueous dispersions comprising monodisperse swellable seed polymers/oligomers, and initiating polymerization in the presence of a steric stabilizer. The resulting swollen seed particles are characterized by the particle mode diameter.

Abstract: A process for the preparation of monodisperse polymer particles which are formed by contacting monomers with aqueous dispersions comprising monodisperse swellable seed polymers/oligomers, and initiating polymerization in the presence of a steric stabilizer. The resulting swollen seed particles are characterized by the particle mode diameter.

Abstract: A procedure for the production of PVC particles with a narrow size distribution in the range 10-50 &mgr;m, preferably 10-30 &mgr;m, in which, in a first stage, a vinyl monomer or a mixture of monomers is polymerised to form a polymer/oligomer seed particle in the range 1-10 &mgr;m. In a second stage, another vinyl monomer or mixture of monomers is swelled into the polymer/oligomer seed particles and polymerisation takes place in such a way that they grow into polymer particles of the desired size. It is preferable to use aromatic vinyl monomers or acrylates as the monomer in the seed particles. The seed particles in the first stage can be produced in a two-stage swelling process or by dispersion polymerisation.

Abstract: A process for preparing an aqueous emulsion with a narrow droplet size distribution of an oily material comprising one or more highly water insoluble substances, wherein the oily material is homogenized in a hydrophilic phase in which the oily material is more soluble than in water, but still so insoluble that an emulsion is formed by the homogenization, and the emulsion is subsequently diluted with a high proportion of water to form a stable emulsion of the oily material having the desired narrow size distribution. The stable emulsion may be mixed with an excess of a partly water soluble material which becomes absorbed by the droplets of the oily material. Said partly water soluble material may comprise a polymerizable monomer, and polymerization is subsequently effected to prepare a dispersion of polymer particles, and if desired, the polymer particles are recovered from said dispersion.

Abstract: The present invention provides a method of linking a target particle to an insoluble support, wherein said particle is bound support by means of a specific binding partner, characterized in that the linkage between said binding partner and said support comprises hydroxyboryl/cis-diol bond. The invention has particular utility in the immobilization and isolation of cells.

Abstract: Process for producing a dispersion, wherein dispersed slightly crosslinked polyvinyl seed particles are swollen with an ionizing liquid, said seed particles containing covalently linked ionizable groups causing a swelling of the seed particles by the ionizing liquid to form a dispersion of droplets, wherein the resulting droplets after the swelling have a volume which is at least five times that of the seed particles. Said ionizing liquid may be or contain a polymerizable monomer or be charged with such a monomer. Polymerization of the monomers is effected in the droplets during or after the swelling, to form polymer particles.

Abstract: Magnetic polymer particles prepared by treating compact or porous polymer particles with a solution of iron salts and, if desired, salts of other metals which are capable of forming magnetic ferrites, in which the solution swells or penetrates into the particles. Iron hydroxide and possible other metal hydroxides are precipitated, for instance by raising the pH value, and the particles are optionally heated. In the iron salts used the ratio between di- and trivalent iron is suitably such that magnetic iron oxide is formed directly. It is also possible to use oxidizing or reducing groups or additives to obtain such a ratio. When other metal salts are used in addition to iron salts, the operation is carried out in the same manner. For instance, when Mn.sup.++, Co.sup.++ or Ni.sup.++ salts are used in addition to Fe.sup.++ salts, the divalent iron is oxidized to trivalent so that magnetic ferrite is obtained. The polymer particles which are treated with metal salts preferably contain metal-binding groups.

Abstract: Magnetic polymer particles prepared by treating compact or porous polymer particles with a solution of iron salts and, if desired, salts of other metals which are capable of forming magnetic ferrites, in which the solution swells or penetrates into the particles. Iron hydroxide and other metal hydroxides, if employed, are precipitated, e.g. by raising the pH value, and the particles are optionally heated. In the iron salts used, the ratio between di- and trivalent iron is suitably such that magnetic iron oxide is formed directly. It is also possible to use oxidizing or reducing groups or additives to obtain such a ratio. When other metal salts are used in addition to iron salts, the operation is carried out in the same manner. For instance, when Mn.sup.++, Co.sup.++ or Ni.sup.++ salts are used in addition to Fe.sup.++ salts, the divalent iron is oxidized to trivalent so that magnetic ferrite is obtained. The polymer particles which are treated with metal salts preferably contain metal-binding groups.

Abstract: The invention provides a process for the preparation of polymer latex by emulsification of an initiator or initiator mixture and optionally a solvent in the presence of emulsifier in water in a first step and adding a monomer and polymerizing in a second step. The process is carried out by emulsifying an essentially water-insoluble initiator or initiator mixture in the first step at a temperature above the melting point of the initiator or initiator mixture if no solvent is used, and below its decomposition temperature, optionally together with an essentially water-insoluble liquid solvent, which forms a liquid solution together with the initiator or the initiator mixture at the emulsification temperature, then, in a second step adding monomer, possibly additional emulsifier and that part of the desired amount of water which was not added in the first step, and initiating polymerization as per se known by heating.

Abstract: Process for preparing aqueous dispersions of a somewhat water-soluble low-molecular organic material, in which swellable particles prepared in a first step are swelled with the organic material in the second step. When the organic material is a polymerizable monomer the dispersion prepared is converted to a polymer dispersion. In the first step swellable oligomer or oligomer-polymer particles are prepared by(a) dispersing an aqueous mixture containing an oil-soluble initiator or a solution of an oil soluble initiator in an organic solvent, and then swelling the dispersed initiator-containing droplets with monomer and effecting polymerization, or(b) swelling polymer particles in aqueous dispersion with vinyl monomer and an oil-soluble initiator and effecting polymerization, the ratio between initiator and monomer used being so high that in the polymerization an oligomer having a degree of polymerization of 5-200 is formed.

Abstract: The invention provides monodisperse polymer particles and dispersions thereof, said particles having a diameter of preferably 5 .mu.m or more. Such polymer dispersions are prepared by in a first step preparing a dispersion of smaller monodisperse polymer particles containing one or more materials having a very low solubility in water, and a relatively low molecular weight, then in a second step adding a partly water-soluble monomer which diffuses into the particles from the first step, and then effecting polymerization.

Abstract: The invention provides a process for preparing an aqueous emulsion or dispersion of a partly water-soluble material, and optionally further conversion of the prepared dispersion or emulsion to a polymer dispersion when the partly water-soluble material is a polymerizable monomer. In a first step a dispersion of polymer particles is prepared containing one or more materials having a very low solubility in water, then in a second step there is added the partly water-soluble material which diffuses into the particles from the first step, and then, if the partly water-soluble material is a polymerizable monomer, polymerization may be effected.

Abstract: Process for producing finely divided aqueous emulsions from materials of ited water solubility. These materials are diffused into pre-formed particles dispersed in water which are formed from vinyl compounds by emulsion polymerization under conditions which cause the pre-formed seed latex to include in the particles 10-100 percent oligomers having a molecular weght of 200-10,000. These seed particles take up 20-500 times their own volume of the material of limited water solubility.

Abstract: A polymer emulsification process comprising intimately dispersing a liquified water insoluble polymer phase in an aqueous liquid medium phase containing at least one nonionic, anionic or cationic oil-in-water functioning emulsifying agent, in the presence of a compound selected from the group consisting of those hydrocarbons and hydrocarbyl alcohols, ethers, alcohol esters, amines, halides and carboxylic acid esters which are inert, non-volatile, water insoluble, liquid and contain a terminal aliphatic hydrocarbyl group of at least about 8 carbon atoms, and mixtures thereof, and subjecting the resulting crude emulsion to the action of comminuting forces sufficient to enable the production of an aqueous emulsion containing polymer particles averaging less than about 0.5 .mu. in size.

Abstract: A process for preparing a latex by efficiently homogenizing an aqueous mixture containing an emulsifier and a water-insoluble solvent for the monomer(s) to be polymerized, adding monomer and if desired further water to the homogenized mixture and also a water-soluble polymerization initiator. Instead of a water-soluble polymerization initiator an oil-soluble polymerization may be used having sufficient solubility to diffuse through the aqueous phase into the drops of water-insoluble solvent and monomer.