Method for producing capsules containing an active ingredient and having an ultra-thin coating

The method as claimed in any of the preceding claims, where the interfacial polymerization is light-induced and the irradiation time is preferably about 5 to about 60 min at an irradiation intensity of from about 5 to about 30 mW/m2 and at an irradiation maximum of about 254 nm.

The method as claimed in any of the preceding claims, where the reaction temperature for the interfacial polymerization is about 10° C. to about 100° C., preferably about 20 to about 50° C.

The method as claimed in any of the preceding claims, where the monomer concentration in the starting mixture is about 5 to about 60 mmol/l, preferably about 5 to about 30 mmol/l.

The method as claimed in any of the preceding claims, where the initiator concentration in the starting mixture is about 0.05 to about 0.5 mmol/l, preferably about 0.05 to about 0.2 mmol/l.

The method as claimed in any of the preceding claims, where the active ingredient concentration in the starting mixture is about 0.001 to about 50% by weight, preferably about 5 to about 40% by weight, in particular about 25 to about 40% by weight, based on the starting mixture.

The method as claimed in any of the preceding claims, where the dispersion time is about 0.5 to about 3 minutes.

The method as claimed in any of the preceding claims, where the interface-active monomer is chosen from the group of interface-active (meth)acrylates, succinates and sulfonates, and derivatives thereof.

The method as claimed in any of the preceding claims, where the comonomer is chosen from acrylic acids and derivatives, such as tetraethylene glycol diacrylates, tetrapropylene glycol diacrylates and mixtures thereof;

• methacrylic acids and derivatives, such as ethylene glycol dimethacrylates, triethylene glycol dimethacrylates, tetrapropylene glycol dimethacrylates and mixtures thereof;
• diallylamines;
• and diallyl sulfides.

The method as claimed in any of the preceding claims, where the polymer capsules, pellets or droplets which contain an active ingredient and have been prepared in this manner have a ratio of coating thickness to capsule diameter of from about 1:5000 to about 1:5, preferably from about 1:1000 to about 1:10, in particular from about 1:500 to about 1:100.

The method as claimed in any of the preceding claims, where the polymer capsules, pellets and droplets which contain an active ingredient and have been prepared in this way have average particle diameters of from about 50 nm to about 50,000 nm, preferably from about 100 nm to about 5000 nm, very particularly preferably from about 100 to 1000 nm.

The method as claimed in any of the preceding claims, where the polymer capsules, pellets or droplets which contain an active ingredient and have been prepared in this way have an active ingredient content of from about 1 to about 99% by weight, in particular from about 10 to about 80% by weight, preferably from about 50 to about 80% by weight, based on the total weight of the polymer capsules, pellets or droplets.

The method as claimed in any of the preceding claims for the encapsulation or for the enclosure of active ingredients in polymer capsules, pellets or droplets having an ultra-thin diffusion-tight coating.

A polymer capsule, pellet or droplet containing an active ingredient and which comprises at least one active ingredient enclosed in a polymer matrix and whose coating comprises a polymer obtainable by free-radical interfacial polymerization of at least one interface-active monomer and optionally at least one comonomer.