Abstract: The constituents of an exhausted toluene-dimethylformamide solvent mixture used for removing polyvinyl chloride deposits from polymerization reactors, are separated by adding water to said mixture and distilling off toluene, thereby to obtain a distillation residue having a water content of at least 2 wt.% and a toluene content not exceeding 10 wt.%, precipitating the polymer by cooling the distillation residue, adding a further amount of water, distilling off any toluene present, recovering the precipitate and distilling the residual aqueous solution to recover the dimethylformamide.
Abstract: A tackifier composition comprised of a tackifying resin and a selected oily polymer distillation cut as well as an admixture thereof with selected rubbery polymers to achieve an adhesive composition. Said tackifier composition is comprised of both a tackifying resin derived from the polymerization of a mixture of at least one olefin and at least one diolefin as well as an oily polymer distillation cut at a temperature in the range of about 190.degree. C to about 250.degree. C of the product of polymerizing a monomer mixture comprised primarily of piperylene and selected monoolefins with the optional addition of dicyclopentadiene and .alpha.-methyl styrene.
Abstract: Hydrocarbon resins comprising about 95-35% by weight of units derived from 1,3-pentadiene, about 1-50% by weight of units derived from cyclododecatriene, and O-about 40% by weight of units derived from at least one monoolefin containing 5 carbon atoms, having a softening point of from about 100.degree. to about 160.degree. C., and being substantially gel-free. The hydrocarbon resins can be prepared by polymerizing a monomeric mixture comprising 1,3-pentadiene in the presence of a Friedel-Crafts type metal halide catalyst, said monomeric mixture comprising about 95-35% by weight of 1,3-pentadiene, about 1-50% by weight of cyclododecatriene, and 0-about 50% by weight of at least one monoolefin containing 5 carbon atoms.
Abstract: Residual vinyl chloride contents of aqueous polyvinyl chloride dispersions is reduced to less than 50 ppm by withdrawing steam and vinyl chloride contained in a boiling aqueous polyvinyl chloride dispersion at a temperature of 80.degree.-100.degree. C. and at a vaporization rate per minute of 0.006-0.2 kg. steam per kg. of polyvinyl chloride for a period of time from 3-60 minutes until a vinyl chloride content of less than 50 p.p.m. is achieved.
Type:
Grant
Filed:
August 28, 1975
Date of Patent:
April 12, 1977
Assignee:
Chemische Werke Huls Aktiengesellschaft
Inventors:
Hans Grosse-Wortmann, Bernhard Hentschel, Peter Rauth, Karl-Heinz Schoenberg, Bernd Terwiesch, Hermann Winter
Abstract: An improvement in the process for removing vinyl chloride from a water-polyvinyl chloride slurry, which contains unreacted vinyl chloride, by steam distillation is disclosed. In many instances, steam distillation of the slurry results in an increase in the number of gels or fish eyes. The improvement comprises conducting the steam distillation in the presence of a minor, but effective, amount of an alkali metal sulfite or carbonate. The improved process results in a polyvinyl chloride having no substantial increase in, or a reduced amount of, gels or fish eyes, while still having good heat stability and porosity properties.
Abstract: A cyclic process is provided for the polymerization and hydrogenation of certain polymers wherein the monomer is anionically polymerized in solution, the living polymers then being terminated by the use of a proton donor, after which the polymer is subjected to catalytic hydrogenation wherein the catalyst is optionally activated with certain polar compounds after which the polymer is coagulated and heated to remove any residual terminator and activator and the solvent is fractionally distilled to recover and recycle the solvent without contamination from the substantially higher boiling terminator and optional activator.
Abstract: Vinyl chloride is removed from wet cakes that comprise a vinyl chloride polymer, vinyl chloride, and water by contacting the wet cakes with steam, preferably at atmospheric pressure and at a temperature in the range of 100.degree. to 125.degree.C.
Type:
Grant
Filed:
June 24, 1974
Date of Patent:
May 11, 1976
Assignee:
Tenneco Chemicals, Inc.
Inventors:
Donald Goodman, Robert S. Miller, Robert J. Stanaback
Abstract: a process for the separation of diluent from an ethylene polymerization reaction mixture wherein ethylene is copolymerized using as a catalyst an organo-metallic compound supported on an inorganic material. Subsequent to reaction, there is added to the reaction mixture a wetting agent and the diluent is then removed from the reaction mixture by steam distillation to give a product having significant solubility in the diluent.A wide variety of wetting agents may be used, which may be either water-soluble or water-insoluble. However, water soluble wetting agents are much preferred, so that most or at least some of the wetting agent remains in the aqueous phase at the end of the steam distillation step. The wetting agent may also possess hydrocarbon solubility; but this does not appear to be of paramount importance. It should also be stable at the steam distillation temperature and should have low steam volatility.
Type:
Grant
Filed:
March 8, 1976
Date of Patent:
April 5, 1977
Assignee:
Imperial Chemical Industries Limited
Inventors:
Denis George Harold Ballard, Eric Jones
Abstract: a method of continuously treating an aqueous latex of a synthetic polymer which contains unreacted residual monomer from the polymerization reaction used for the production of the polymer, which method comprises feeding the aqueous latex as a spray into the top of a vertical column so that it forms a liquid film on the inner surface thereof which film then flows down the column, and contacting the spray and the descending film with an upward flow of a hot inert gas or vapor whereby residual monomer is separated from the latex and is removed with the flow of inert gas or vapor leaving the column. Apparatus for carrying out the method is also claimed. The method is advantageously employed for the removal of residual vinyl chloride monomer from a latex of a vinyl chloride polymer.