Functionalized particles
Functionalized particles having fully formed shells and cores comprising a polyurethane or polyurea matrix obtained by interfacial addition polymerisation of (i) at least one polyisocyanate derivative selected from the group of partially blocked polyisocyanates and polyisocyanates partially modified with fiber reactive groups and (ii) at least one polyamine or polyhydric alcohol, said functionalized particles being capable to chemically or physically bind to a substrate.
1. Functionalized particles having fully formed outer shells and cores comprising a polyurethane or polyurea matrix said outer shells obtained by interfacial addition polymerisation of (i) at least one partially blocked polyisocyanate obtained by the reaction of a polyisocyanate with 10 to 15 mol % total, based on the stoichiometric amount of isocyanate groups contained within the polyisocyanate of a blocking group precursor selected from an active methylene compound, a bisulfite, a phenol, a pyridinol, a thiophenol, a mercaptopyridine, a mercaptane, an oxime, an amide, a cyclic amide, an imide, an imidazole, an amidine, a pyrazole, a triazole, a siloxane and a benzoxazolone and (ii) at least one polyamine or polyhydric alcohol, said fimetionalized particles being capable to chemically or physically bind to a substrate.
2. Functionalized particles according to claim 1 , wherein the blocking group precursor is an oxime.
3. Functionalized particles according to claim 1 , wherein the blocking group precursor is an imidazole.
4. Functionalized particles according to claim 1 , wherein the blocking group precursor is a siloxane.
5. Functionalized particles according to claim 1 , wherein the polyisocyanate is a diisocyanate or a triisocyanate.
6. A process for preparing functionalized particles comprising preparing an oil-in-water dispersion and causing condensation polymerisation at the oil-water interface around each dispersed oil droplet of (i) at least one partially blocked polyisocyanate dissolved in the oil phase and (ii) at least one polyamine or polyhydric alcohol dissolved in the aqueous phase wherein the partially blocked polyisocyanate is obtained by the reaction of a polyisocyanate with 10 to 15 mol %, based on the stoichiometric amount of isocyanate groups contained within the polyisocyanate of a blocking group precursor selected from an active methylene compound, a bisulfite, a phenol, a pyridinol, a thiophenol, a mercaptopyridine, a mercaptane, an oxime, an amide, a cyclic amide, an imide, an imidazole, an amidine, a pyrazole, a triazole, a siloxane and a benzoxazolone.
7. A process according to claim 6 , wherein the oil phase additionally contains a substance which is to be encapsulated.
8. A process for the preparation of a substrate modified with the functionalized particles according to claim 1 , comprising reacting the substrate with the functionalized particles according to claim 1 , so that the functionalized particles chemically or physically bind to the substrate.
9. A process according to claim 8 , wherein the substrate is a fiber material containing a hydroxyl group or nitrogen.
10. A process according to claim 8 , wherein the substrate is a cellulosic fiber material.
11. A process according to claim 8 , wherein the substratae is a natural or synthetic polyamide fiber material.