Sumitomo Chemical Company, Limited

Nobuaki Tabei

Hiroshi Sato

Kazuhisa Endo

Noriaki Saitou

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.

Granular coated fertilizer

The present invention provides a granular fertilizer which is coated with a thermosetting resin layer (first thermosetting resin layer), a 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.

The present invention provides a method for producing a controlled-release coated fertilizer which provides few floats when applied in water, gives uniform coat and makes it possible to release fertilizer ingredient constantly in a short time at ordinary temperature to low temperature. The method comprises adding water-absorptive polymer to granular fertilizer and then coating it with at least one urethane resin layer.

Method for producing granular coated fertilizer

A process for purifying 1,1,3,4,4,6-hexamethyltetralin is disclosed comprising melting crude 1,1,3,4,4,6-hexamethyltetralin in methanol with heating, cooling the resulting suspension, and adding seed crystals at a temperature of 45.degree.-60.degree. C.; as well as a process for purifying 1,1,3,4,4,6-hexamethyltetralin comprising recrystallizing crude 1,1,3,4,4,6-hexamethyltetralin from a mixed solvent of methanol and a solvent capable of easily dissolving 1,1,3,4,4,6-hexamethyltetralin, the proportion of this solvent being 10 to 25% by weight based on the weight of methanol. These processes make it possible to obtain 1,1,3,4,4,6-hexamethyltetralin of high purity easily with high recovery by purifying crude 1,1,3,4,4,6-hexamethyltetralin.

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Toyonaka, Japan

Nobuaki Tabei