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NEWS
United States Patent Office
the newsmagazine of t h e chemical world VOLUME 35, NUMBER 52
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DECEMBER 30, 1 9 5 7
2,816,883 Patented Dec. 17, 1957
Unity. Other objects and advantages will hereinafter ap pear. This invention provides new ethylene polymers pos sessing a combination of properties unatlamed in any huherto known ethylene polymer. These ethylene poly mers melt in the range of 127* to 132* O , have a stiff ness modulus of from 137,000 to 215.00O lbs./in. a , a breaking strength, based on the drawn dimensions, of 40,000 to 55,000 ib./in. a , an elongation at break of 1200 ι to 1300%, a relative viscosity of from 1.0 to 1.5, measured No Drawing. Application August 2, 1951, at 0.125% concentration in xylene at 85* C., a degree Serial N o . 240,044 of chain branching corresponding to less than one side 6 Claims. (CL 260—94.9) chain per 200 carbon atoms in the main polymer chain, and an amorphous content of not more than 10%. > The novel ethylene polymers of this invention are made This invention relates to new macromolecular poly by subjecting ethylene to pressures of from about 5,000 mers of ethylene and to methods for tbeir preparation. to 20,000 atmospheres at temperatures above 45* C. but The application is a continuation-in-part of copending below 200* C , preferably in the presence of a material application, S. N. 739,264, filed April 3, 1947, now aban which yields reactive free radicals under the conditions of doned. Subject matter described and claimed herein was disclosed in applicants* copending continuation appiica- 20 reaction In a preferred method for preparing the novel ethylene tion, Serial Number 563,699, filed February 6r 1956, and polymers of this invenuon, a pressure reactor is charged now abandoned. with a solvent, such as an aromauc, cycloaliphauc, or It is known that when ethylene is subjected to pressures paraffmic hydrocarbon, or an alcohol, and from 0.01 to ΜψΜ. in the range of 500 to 3000 atmospheres, at temperatures 1%, based on the charge, of a substance wâich yields reof 100" to 300° C , it polymerizes to products ranging 25 acuve free radicals under the condiuons of reacuon, such from oily liquids to wax-uke solids. As generally pro as an organic peroxy compound or azonitrile, the reactor duced, the wax-like solids melt in the range of 100* to is connected to a source of ethylene and pressured to the 120" C , have an average density of 0.925, an elongation selected pressure with ethylene. The reactor is. then at break of 550 to 700%, a tensile strength on final crosssection of 16,000 lbs./in. a , a stiffness modulus in the 30 closed and heated to between 45 and 200* C , preferably a to between 40 and 100* C , and the pressure within the range of 16,000 to 21,000 lb./in. , an amorphous content reactor maintained by further compression. After the of the order of 22%, a degree of chain branching corredesired degree of reaction has been attained, the reactor sponding to about one side «chain per 20 carbon atoms is allowed to cool to room temperature, opened, and the m the chain, and an inherent viscosity of 0.92 measured at contents discharged. The polymer is then isolated by 0.125% concentration in xylroe at 85* C. Although this convenuonal methods. The polymers produced m acrepresents a remarkably combination of properties, for cordance with the process of tJbu> invcauon have melting many industrial u « s they fall short of meeting even minipoints ranging from 127* to 132* C mum requirements. Melting point is determined under a microscope having It is al«o known that in the presence of specific catalysts, and under certain conditions of temperature and pressure, 40 a micro-heating stage provided with controlled means for heating films of polymer of about 100-300 microns m „arbon monoxide and hydrogen react to give methanol and thickness to the fusion temperature. The melting point branched chain higher alcohoU (U. S. Patent 1,770,165). is taken as the temperature at which there is disappearance It is also well known that under certain other conditions of double refraction. 1 involving the use of certain cobalt-containing or ruthenium4 5 The examples which follow are submitted to illustrate contaimog catalysts, the reaction between carbon monoxand not to limit this invention. ide and hydrogen leads to the formation of paraffin waxes Example 1.—Eighty-nine parts of benzene, 0.425 part cher et aL» Brennstoff-Chemie 19, 226-30 (1938); of 2,2*-azobis-2,4-dimethylvaleronitrile, and 78 parts of , 20, 247-50 (1939); cf. also Briu 468,434). ethylene are charged into a pressure vessel capable of _ ι molecular weight straight chain alcohols and other ^Jslssn-cootaining organic compounds have also been oo- 50 withstanding internal pressures of at least 1000 atm. One isj end of the vessel is fitted with a needle valve for admitting ""*~ hydrogénation of carbon monoxide in the pres*"~~ '^suspended in paraffin compressed ethylene, for example, at 1000 atm., and the other end is fitted with a removable closure which makes the Field of Fis--Λ '?* , J g n l ***' when subjected to o-^nt/ynal pressure of sevfol. II, 1948, tr? ir^ung the folk '~~* -106.8' * 2.81M83 PRODUCT A N D PROCESS OF POLYMERIZING ETHYLENE Arthur W. Larchar, Mendenhall, P · . , and Donald C. Pease, Wilmington, Del n assignor* to E. I. da Poot de Nemours SL Company, Wilmington, Del., a corporation of Delaware
Legal Upheaval in Polyethylene Μ α ν erupt O v e r TSias **K^kfUi • JES B l l
