A system and method of producing polyethylene, including: polymerizing ethylene in presence of a catalyst system in a reactor to form polyethylene, wherein the catalyst system includes a first catalyst and a second catalyst; and adjusting reactor conditions and an amount of the second catalyst fed to the reactor to control melt index (MI), density, and melt flow ratio (MFR) of the polyethylene.

A system and method of producing polyethylene, including: polymerizing ethylene in presence of a catalyst system in a reactor to form polyethylene, wherein the catalyst system includes a first catalyst and a second catalyst; and adjusting reactor conditions and an amount of the second catalyst fed to the reactor to control melt index (MI), density, and melt flow ratio (MFR) of the polyethylene.

Disclosed are biaxially stretched polyolefin films containing a) 10 to 45% by weight of a cycloolefin polymer with a glass transition temperature between 120 and 170° C., and b) 90 to 55% by weight of a semi-crystalline alpha-olefin polymer with a crystallite melting temperature between 150 and 170° C., wherein the glass transition temperature of component a) being less than or equal to the crystallite melting temperature of component b), and wherein the polyolefin film has a shrinkage at 130° C. after 5 minutes, as measured according to ISO 11501, of less than or equal to 2%.

These polyolefin films are excellent suited as dielectrics for capacitors but also for other applications and are distinguished by a low shrinkage at high temperatures.

A door assembly. The door assembly may include at least one door panel and a door frame having a plurality of frame members including a header and a pair of side jambs. The invention may also be considered a frame member. The frame member may include a core; and a two-piece top piece adjoining the core to form a structural member. The core and the top piece may be a composite of cellulosic material and at least one other material. The door assembly may further include at least one adjacent panel. Also disclosed are door jamb frame members and mullion frame members.

Disclosed is a method using a metallocene catalyst system so as to control the polymer structure of a diene-modified polypropylene through process simplification, thereby being capable of preparing a hyperbranched polypropylene resin having a low gel content and improved melt strength. The present invention provides a method using a catalyst so as to polymerize propylene and a diene compound, thereby preparing a diene-modified polypropylene resin having a branching index of 0.95 or less, a gel content of 3 wt % or less and an advanced rheometric expansion system (ARES) melt strength of 5 g or more.

Provided are an ethylene polymer mixture, a method of preparing the same, and a molded article using the same. More specifically, an ethylene polymer mixture in which two ethylene polymers having different densities are mixed, a method of preparing the same, and a molded article having a low haze and a low heat sealing temperature using the ethylene polymer mixture, are provided.

Ethylene-based polymers are characterized by a density from 0.92 to 0.955 g/cm.sup.3, a HLMI of less than 35 g/10 min, and a ratio of a number of short chain branches (SCBs) per 1000 total carbon atoms at Mz to a number of SCBs per 1000 total carbon atoms at Mn in a range from 11.5 to 22. These polymers can have a higher molecular weight (HMW) component and a lower molecular weight (LMW) component, in which a ratio of a number of SCBs per 1000 total carbon atoms at Mn of the HMW component to a number of SCBs per 1000 total carbon atoms at Mn of the LMW component is in a range from 10.5 to 22. These ethylene polymers can be produced using a dual catalyst system containing an unbridged metallocene compound with an indenyl group having at least one halogen-substituted hydrocarbyl substituent with at least two halogen atoms, and a single atom bridged metallocene compound with a fluorenyl group and a cyclopentadienyl group.

The present disclosure provides a method of determining a relative decrease in catalytic efficacy of a catalyst in a test sample of a catalyst solution with unknown catalytic activity. The method includes (a) mixing the test sample with a test solvent to form a test mixture and (b) measuring the increase in the temperature of the test mixture at predetermined time intervals immediately after forming the test mixture. A predetermined feature is used to determine both a test value in the increase in temperature measured in (b) and a control value in a known increase in temperature of a control mixture of the test solvent with a control sample of a control catalyst solution. The relative decrease in catalytic efficacy of the catalyst in the test sample having the unknown catalytic activity is then determined from: Relative Decrease in Catalytic Efficacy=Control Value−Test Value/Control Value

The present disclosure provides a method of determining a relative decrease in catalytic efficacy of a catalyst in a test sample of a catalyst solution with unknown catalytic activity. The method includes (a) mixing the test sample with a test solvent to form a test mixture and (b) measuring the increase in the temperature of the test mixture at predetermined time intervals immediately after forming the test mixture. A predetermined feature is used to determine both a test value in the increase in temperature measured in (b) and a control value in a known increase in temperature of a control mixture of the test solvent with a control sample of a control catalyst solution. The relative decrease in catalytic efficacy of the catalyst in the test sample having the unknown catalytic activity is then determined from: Relative Decrease in Catalytic Efficacy=Control Value−Test Value/Control Value

An olefin-based copolymer and a method of making the same are disclosed herein. In some embodiments, an olefin-based copolymer has a density (d) of 0.85 to 0.89 g/cc, a melt index (MI), measured at 190° C. and 2.16 kg load, of 15 g/10 min to 100 g/10 min, a number of unsaturated functional groups (total V) per 1,000 carbon atoms of 0.8 or less, a vinylene content, and a vinyl content, wherein the vinylene content, the vinyl content and the total V satisfy (a) vinylene content/total V=0.1 to 0.7 and (b) vinylene content/vinyl content=0.8 to 1.6. The olefin-based copolymer has controlled content and kind of an unsaturated functional group in the olefin-based copolymer and thus, has high flowability, and may show improved physical properties of hardness, flexural strength and tensile strength.