Adsorbents, process for the production thereof and use thereof
View Patent ↗An adsorbent for organic compounds including filler granules, which contain 20 to 99.9 wt. % of fillers and a binder. The adsorbent is produced by mixing at least one binder with at least one filler and performing granulation in a mixing or granulation apparatus. The adsorbent may be used for adsorbing and/or absorbing organic and/or inorganic substances from a liquid or gaseous phase.
1. A spherical granular adsorbent for organic compounds consisting of granules which contain 20 to 99.9 wt.% of filler particles of silica and rubber as a binder, said adsorbent having been made by a process of mixing at least one binder which is rubber with at least one filler particle which is silica in a granulator having a spiked shaft, by injecting the binder by means of at least one nozzle into said granulator in at least one location and granulating resulting mixture, whereby the filler particles are incorporated into the surface of the binder such that the resulting adsorbent does not stick together, said mixing taking place at a temperature of from 20° to 140° C, with a rotational speed of the granulator being from 100 to 1500 rpm, and where the circumferential speed of spike tips in said spiked shaft is 1 to 30 meters/sec.
2. The spherical granular absorbent according to claim 1 , wherein the filler particles consist precipitated or pyrogenic silica, the surface of which is modified with one or more organosilicon of the formulae
[R 1 n (RO) 3-n Si-(Alk) m —(Ar)p]q[B] (I),
R 1 n (RO) 3-n Si-(Alkyl) (II),
or
R1 n (RO) 3-n Si-(Alkenyl) (III)
in which
B: means -SCN, -SH, -Cl, -NH 2 (if q=1) or —Sx—(if q=2)
B is attached to Ar when p=1, or B is attached to Alk when p=0,
R and R 1 : mean an alkyl group, branched or unbranched, having 1 to 4 carbon atoms,
a phenyl residue, wherein all residues R and R 1 may in each case have the same or a different meaning,
n: means 0; 1 or 2
Alk: means a divalent linear or branched carbon residue having 1 to 6 carbon atoms,
m: means 0 or 1
Ar: means an arylene residue having 6 to 12 C atoms
p: means 0 or 1, providing that p and n do not simultaneously mean 0,
q: is 1 or 2
x: means a number from 2 to 8,
Alkyl: means a monovalent linear or branched, unsaturated hydrocarbon residue having 1 to 20 carbon atoms,
Alkenyl: means a monovalent linear or branched, unsaturated hydrocarbon residue having 2 to 20 carbon atoms.
3. The spherical granular absorbent according to claim 2 wherein R and R 1 are each alkyl.
4. The spherical granular according to claim 2 wherein alkyl is 2 to 8 carbon atoms.
5. The spherical granular according to claim 2 wherein alkenyl is 2 to 8 carbon atoms.
6. The spherical granular adsorbent according to claim 1 , characterized in that natural rubber, emulsion SBR having a styrene content of 10 to 50%, butyl/acrylonitrile rubber, butyl rubber, nitrile rubber, terpolymers of ethylene, propylene (EPM) and unconjugated dienes (EPDM), butadiene rubber, DBR, produced by the solution polymerization process, having a styrene content of 10 to 25%, and 1,2-vinyl unit contents of 20 to 55% and isoprene rubbers, in particular 3,4-polyisoprene, fluororubber, chlorinated rubber, silicone rubber, carboxyl rubbers, epoxy rubbers, trans-polypentenamer, halogenated butyl rubbers, rubbers prepared from 2-chlorobutadiene, ethylene/vinyl acetate copolymers, block polymers, epichlorohydrins, chemically modified natural rubbers, such as for example epoxidised grades, are used as binder diluted or undiluted, individually or as a mixture, with a content of 0.1 to 80 wt.%.
7. A process for the production of the spherical granular adsorbent according to claim 1 , comprising mixing at least one binder with at least one filler particle which is silica and granulating resulting mixture in a mixing or granulation apparatus.
8. An article filled with the spherical granular adsorbent of claim 1 for use in containment of oil spills.