| 摘要 |
1299746 Encapsulated materials MINNESOTA MINING & MFG CO 20 April 1970 [21 April 1969 8 May 1969] 18781/70 Heading ASE [Also in Divisions B8 and Cl] Capsules containing a liquid which is slowly released over a long period are made by encapsulating the liquid in a mantle composed of crystalline polyolefine and a compatible hydrocarbon resin, e.g. a petroleum resin, terpene resin or an indene or coumarone-indene resin. Optionally, a hydrocarbon wax, desirably of M.W. in the range 300 to 1500, may also be present. The liquid may in particular be a fertilizer or herbicide, those specifically mentioned being 2,4-dichloro-phenoxy acetic acid and trichloroacetic acid salts, 1,1'-ethylene- 2,2'-dipyridinium bromide (Diquat) and a fertilizer mixture comprising KCI, urea and NH 4 H 2 PO 4 . The capsules may be prepared by conventional methods, e.g. by subdividing a biliquid column, the outer portion of which is liquid encapsulating material, the inner portion being the liquid to be encapsulated and solidifying the encapsulating material. |
