摘要:
Polymer compositions comprising .alpha.-olefin polymers and a minor proportion of synthetic basic zeolite are stabilized against the harmful effects of corrosion of metal surfaces when processed through mechanical equipment such as molds and extruders where the composition normally contacts metal surfaces.
摘要:
Polypropylene impact copolymer compositions demonstrate not only good low temperature properties, including impact strength, but also resistance to stress whitening when the numerical ratio of the intrinsic viscosity of the copolymer phase to the intrinsic viscosity of the homopolymer phase is near unity and ethylene contents of the copolymer phase are in the range of 38% to 60% by weight. The impact copolymer compositions are useful in the production of molded and extruded articles, shaped containers, and films having good clarity.
摘要:
Polypropylene impact copolymer compositions and visbroken derivatives thereof demonstrate a good balance of low temperature properties and resistance to stress whitening when the homopolymer phase is at least predominantly homopolymeric polypropylene and the rubber phase comprises a major proportion of ethylene with a minor proportion of .alpha.-olefin of at least 4 carbon atoms and a minor proportion of propylene.
摘要:
In the gas phase, two stage process for the production of polypropylene impact copolymer, the fouling of the second stage recycle loop and the heat exchange unit incorporated therein is reduced by the addition to the substantially gaseous material passing through the loop of a small amount of alkylene compound selected from alkylene glycol compounds, alkylene glycol derivatives of alkylene diamines or ethers or esters thereof.
摘要:
An improved process for making changes in polymer product type in an ongoing olefin polymerization process without undue disruption of the ongoing polymerization process comprises adding to the polymerization reactor a hydrogenation catalyst and sufficient molecular hydrogen to hydrogenate the unreacted olefin monomer, subsequently removing hydrogenated product and hydrogenation catalyst while resuming polymerization to produce polymer product of changed type upon addition to the reactor of olefin feed appropriate for production of such polymer product of changed type.
摘要:
A process for reacting molten polyolefin with a free radical generator wherein the molten polyolefin passes through an extruder and free radical generator is mixed with the molten polyolefin in increments along the extruder such that any previously added free radical generator is decomposed before the next increment of free radical generator is added to the molten polyolefin. Products of the process demonstrate improved efficiency of free radical generator utilization as measured by enhanced melt flow rates relative to the total amount of free radical generator used.
摘要:
A method for processing of recyclable polymeric materials comprising the addition of a relatively lower shear viscosity polybutylene and optionally at least one filler to these recyclable materials prior to or during processing. Products produced by this process have and exhibit improved performance properties.
摘要:
A process for making polymer pellets comprising unreacted free radical generator which can be degraded upon thermal treatment to form an ultra low melt viscosity polyolefin, which process comprises the steps of adding polyolefin and free radical generator required for the degradation in the extruder to the first half section of an extruder and injecting, optionally through a side-arm extruder, another portion of free radical generator near the exit of the extruder to provide a sufficient amount of unreacted free radical generator in the pellets produced, and followed by pelletizing the resulting molten mixture to form uniform non-sticky pellets.
摘要:
Polypropylene impact copolymer compositions containing a nucleating agent demonstrate not only good low temperature properties, including impact strength, but also resistance to stress whitening when the numerical ratio of the intrinsic viscosity of the copolymer rubber phase to the intrinsic viscosity of the homopolymer phase is near unity and ethylene contents of the copolymer phase are in the range of 38% to 60% by weight. The impact copolymer compositions are useful in the production of molded and extruded articles, shaped containers, and films having good clarity.
摘要:
A method for the prevention of fouling of metallic surfaces exposed to reactive alpha-olefin gases during the production of polymeric resins which comprise coating such metallic surfaces with an amino silicone fluid and thereafter curing said coating by hydrolysis to form a continuous solid coating.