Patent GB-828536-A (GB)
Title: Low temperature polymerisation of iso-olefins
IPC: B01J19/18
Filed: 1956-06-27
Abstract: Monomers are fed into the reactor 1, through inlet tubes 5.  A dilute feed i.e. less than 8% of one of the monomers in a solvent at -143 DEG  to -144 DEG  F. is added until passages 3 are substantially full, the agitator 6 is started and the flow of refrigerant at -160 DEG  F. is begun while the dilute feed is replaced by a full strength feed of 24% of said monomer and optionally 1% of a comonomer in said solvent through inlet tubes 5, the flow being adjusted so that when the refrigerant completely fills the cooling jacket the composition is at least 11% of the first monomer and optionally 0.4% of the second monomer in a solvent.  The catalyst is introduced through retractable inlet nozzles 7, 8 in <PICT:0828536/III/1> the fully inserted position, so that the catalyst mixes with the reactants at a point adjacent to the point of feed before the monomers are drawn upwardly.  After the initial period the catalyst inlet nozzles are withdrawn and the catalyst fed at a point remote from the point of feed of the monomers to intermingle at the down-draught tubes 3.ALSO:<PICT:0828536/IV (a)/1> In a process for the polymerization of isoolefines, alone or with copolymerizable multiolefines, at a low temperature with a Friedel-Crafts catalyst, in a reactor with circulating passages and a cooling jacket, in which a solution of the iso-olefine in an inert diluent, non-solvent for the polymer, is fed at a temperature above its freezing-point and circulated and then cooled with a refrigerant at a temperature at least 10 DEG  F. below the freezing-point of the reactor contents, a solution of the catalyst in an inert diluent is fed at a temperature above its freezing-point to a point adjacent to the point of feed of the monomer until the reaction is initiated, and then fed to a point remote from the point of feed.  Isobutylene, 3-methylbutylene-1, 4-ethylpentene-1, isoprene, butadiene-1,3, piperylene, hexadiene-2,4, dimethallyl, cyclopentadiene, myrcene and 6,6-dimethyl fulvene are referred to.  In an example, butyl rubber is prepared using a methyl chloride diluent and aluminium chloride catalyst in an apparatus (Figure) in which the monomers are fed into the reactor 1, through inlet tubes 5.  A dilute feed, i.e. less than 8% of isobutylene in methyl chloride at - 143 DEG  to - 144 DEG  F. is added until passages 3 are substantially full, the agitator 6 is started and the flow of refrigerant at - 160 DEG  F. is begun while the dilute feed is replaced by a full strength feed of 24% isobutylene and 1% isoprene in methyl chloride through inlet tubes 5, the flow being adjusted so that when the refrigerant completely fills the cooling jacket the composition is 11% isobutylene and 0.4% isoprene in methyl chloride.  The catalyst is introduced through retractable inlet nozzles 7, 8, in the fully inserted position, so that the catalyst mixes with the reactants at a point adjacent to the point of feed before the monomers are drawn upwardly.  After the initial period the catalyst inlet nozzles are with drawn and the catalyst fed at a point remote from the point of feed of the monomers to intermingle at the down-draft tubes 3.  Specification 828,537 is referred to.