Granular coated fertilizer
The present invention provides a granular fertilizer which is coated with a water-insoluble material layer (first water-insoluble material layer), a thermosetting resin layer (first thermosetting resin layer), a water-insoluble material layer (second water-insoluble material layer) and a thermosetting resin layer (second thermosetting resin layer) from inner to outer layers, and it can release fertilizer ingredients for a long time, by a smaller amount of coating materials than known coated fertilizers.
1. A granular fertilizer which is coated with a water-insoluble material layer (first water-insoluble material layer), a thermosetting resin layer (first thermosetting resin layer), a water-insoluble material layer (second water-insoluble material layer) and a thermosetting resin layer (second thermosetting resin layer) from inner to outer layers.
2. A granular coated fertilizer according to claim 1 , wherein at least one of the first thermosetting resin and the second thermosetting resin is urethane resin.
3. A granular coated fertilizer according to claim 1 , wherein both of the first thermosetting resin and the second thermosetting resin are urethane resin.
4. A granular coated fertilizer according to claim 1 , wherein both of the first water-insoluble material and the second water-insoluble material are at least one selected from the group of waxes, fatty acids, fatty acid salts, fatty acid esters, higher alcohols, silicones and mixtures thereof.
5. A granular coated fertilizer according to claim 1 , wherein both of the first water-insoluble material and the second water-insoluble material are wax.
6. A granular coated fertilizer according to claim 1 , wherein the amounts of the first thermosetting resin, the second thermosetting resin, the first water-insoluble material and the second water-insoluble material are 1 to 5, 4 to 14, 0.01 to 0.8, 0.01 to 0.8 part by weight respectively based on 100 parts by weight of the granular fertilizer.