Patent GB-650831-A (GB)
Title: Process for polymerizing olefinic hydrocarbon monomers
IPC: C07C2/18
Filed: 1947-11-21
Abstract: Polymers of the formula (CnH2n)x wherein n represents a whole number from 3 to 5 and x represents an integer greater than 2 are prepared by polymerizing an olefinic hydrocarbon monomer of the group consisting of propylene, the butylenes and the amylenes in the presence of a solid polymerization catalyst in a polymerization reaction zone, separating from the resultant products a polymer fraction of molecular weight intermediate said polymer and said monomer, returning said intermediate polymer fraction to the reaction zone in an amount by weight exceeding the amount of the monomer charge simultaneously applied to the reaction zone, and effecting the polymerization at a pressure at which a primary vapour phase comprising at least a portion of said intermediate polymer is present in the reaction zone simultaneously with a primary liquid phase comprising the olefinic polymer (CnH2n)x. The process is particularly applicable to the preparation of propylene tetramer at a polymerization temperature of 150-250 DEG  C. under a pressure of up to 68 atmospheres.  The catalyst may be a phosphate-containing solid polymerization catalyst, a silica-zirconia composition, or a precalcined composition of a siliceous material and a phosphoric acid.  The olefinic monomer charge, which may be preheated to a temperature near the polymerization reaction temperature, may contain up to 1 per cent by weight of water vapour.  Specifications 437,188 and 463,272, [Group III], are referred to.  The Specification as open to inspection under Sect. 91 is not restricted in the relation between the weights of intermediate polymer fraction and monomer charge applied to the reaction zone, nor need the pressure be such that the primary vapour and liquid phases are present simultaneously. This subject-matter does not appear in the Specification as accepted.ALSO:Polymers of the formula (CnH2n)x wherein n represents a whole number from 3 to 5 and x represents an integer greater than 2 are prepared by polymerizing an olefinic hydrocarbon monomer of the group consisting of propylene, the butylenes and the amylenes in the presence of a solid polymerization catalyst in a polymerization reaction zone, separating from the resultant products a polymer fraction of molecular weight intermediate said polymer and said monomer, returning said intermediate polymer fraction to the reaction zone in an amount by weight exceeding the amount of the monomer charge simultaneously applied to the reaction zone, and effecting the polymerization at a pressure at which a primary vapour phase comprising at least a portion of said intermediate polymer is present in the reaction zone simultaneously with a primary liquid phase comprising the olefinic polymer (CnH2n)x. The process is particularly applicable to the preparation of propylene tetramer at a polymerization temperature of 150-250 DEG  C. under a pressure of up to 68 atmospheres.  The catalyst may be a phosphate-containing solid polymerization catalyst, a silicon-zirconia composition or a precalcined composition of a siliceous material and a phosphoric acid.  The olefinic monomer charge, which may be preheated to a temperature near the polymerization reaction temperature, may contain up to 1 per cent by weight of water vapour.  Specifications 437,188 and 463,272, [Group III], are referred to.  The Specification as open to inspection under Sect. 91 is not restricted in the relation between the weight of intermediate polymer fraction and monomer charge applied to the reaction zone, nor need the pressure be such that the primary vapour and liquid phases are present simultaneously. This subject-matter does not appear in the Specification as accepted.