초록 ▼

A process for the preparation of coated polymer particles containing superparamagnetic crystals, said process comprising reacting porous, surface-functionalized, superparamagnetic crystal-containing polymer particles of diameter 0.5 to 1.8 μm with at least one polyisocyanate and at least one di

A process for the preparation of coated polymer particles containing superparamagnetic crystals, said process comprising reacting porous, surface-functionalized, superparamagnetic crystal-containing polymer particles of diameter 0.5 to 1.8 μm with at least one polyisocyanate and at least one diol or at least one epoxide.

대표청구항 ▼

What is claimed is: 1. A process for the preparation of coated polymer particles containing superparamagnetic crystals, said process comprising reacting porous, surface-functionalized, superparamegnetic crystal-containing polymer particles of diameter 0.5 to 1.8 μm with at least one polyisocya

What is claimed is: 1. A process for the preparation of coated polymer particles containing superparamagnetic crystals, said process comprising reacting porous, surface-functionalized, superparamegnetic crystal-containing polymer particles of diameter 0.5 to 1.8 μm with at least one polyisocyanate and at least one diol; wherein said diol is at least one selected from the group consisting of: polyethylene glycols and diols having the general formula HO((CH2)mO)nH (where n is an integer from between about 1 to 15 and m is an integer from between about 2 to 6). 2. A process as claimed in claim 1 wherein at least two diols are employed. 3. A process as claimed in claim 2 wherein said diols are diethyleneglycol and tetraethyleneglycol. 4. A process as claimed in claim 2 wherein one of said diols is polyethyleneglycol. 5. A process as claimed in claim 1 wherein said polyisocyanate is 4,4-methylene bis(phenylisocyanate) or a polyisocyanate comprising 4,4-methylene bis(phenylisocyanate) with CH2-phenylisocyanate residues. 6. A process as claimed in claim 1 wherein said polyisocyanate is a diisocyanate. 7. A process as claimed in claim 1 wherein said particles are, in a first stage, reacted with a mixture of polyisocyanate and at least one diol in which the polyisocyanate is in a molar excess relative to the diol(s) and, in a second stage, subsequently reacted with at least one diol. 8. A process as claimed in claim 7 wherein two diols are used in the first stage of the reaction and one or two diols are used in the second stage. 9. A process as claimed in claim 8 wherein diethyleneglycol and tetraethyleneglycol are used in both stages of the reaction. 10. A process as claimed in claim 1 wherein the particles are, in a first stage, reacted with polyisocyanate in the absence of diol and, in a second stage, reacted with at least one diol. 11. A process as claimed in claim 10 wherein one diol is employed and said diol is a polyethylene glycol. 12. A process as claimed in claim 1 wherein the particles are amine functionalised. 13. A process as claimed in claim 1 wherein said porous surface-functionalized polymer particles are nitrated and reduced styrene-divinylbenzene polymer particles. 14. A process as claimed in claim 1 wherein the diameter of the polymer particles is between 0.5 to 1.2 μm. 15. A process as claimed in claim 1 wherein the diameter of the polymer particles is about 1 μm. 16. A process as claimed in claim 1 in which said coated particle is subsequently tosylated. 17. A particle obtainable by a process comprising reacting porous, surface-functionalized, superpararmagnetic crystal-containing polymer particles of diameter 0.5 to 1.8 μm with at least one polyisocyanate and at least one diol.