| 摘要 |
Solutions of high molecular weight polymeric materials in liquids compatible therewith are prepared by extruding the polymer, passing the extruded polymer successively through a series of orifices and mixing chambers, the orifices being progressively diminishing in size, and admixing hot pressurized liquid with the polymeric material at the successive orifices and mixing chambers. The extruded polymer may be passed through a series of screens before entering the first mixing chamber. The process may be applied to the production of solutions of polyisobutylene, copolymers of isobutylene with olefinic substances such as styrene, polymers or copolymers of vinyl chloride and/or vinyl acetate, and polyethylene, in materials such as hydrocarbon wax, asphalt, lubricating oils, petroleum naphthas, gasoline, kerosene, ketones and esters. The process is particularly applicable to the production of oil solutions of high molecular weight copolymers of isobutylene and butadiene and/or isoprene.ALSO:Solutions of natural and synthetic rubber in liquids compatible therewith, particularly oils, are prepared by extruding the rubber, passing the extruded rubber successively through a series of orifices and mixing chambers, the orifices being progressively diminishing in size, and admixing hot pressurized liquid with the rubber at the successive orifices and mixing chambers.ALSO:The invention of the parent Specification is modified in that after the board is compressed and cooled it is moistened with water to raise the moisture content to at least 6 per cent. The resin is preferably a phenol-formaldehyde, urea formaldehyde, or furfural resin and may be used in a quantity of 5 to 8 per cent. based on the weight of the mixture being moulded.
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