+

WO1996018679A1 - Compositions de polyethylene a aptitude de mise en ×uvre amelioree et presentant des proprietes physiques ameliorees - Google Patents

Compositions de polyethylene a aptitude de mise en ×uvre amelioree et presentant des proprietes physiques ameliorees Download PDF

Info

Publication number
WO1996018679A1
WO1996018679A1 PCT/US1995/016534 US9516534W WO9618679A1 WO 1996018679 A1 WO1996018679 A1 WO 1996018679A1 US 9516534 W US9516534 W US 9516534W WO 9618679 A1 WO9618679 A1 WO 9618679A1
Authority
WO
WIPO (PCT)
Prior art keywords
range
ethylene
film
polyethylene
percent
Prior art date
Application number
PCT/US1995/016534
Other languages
English (en)
Inventor
Robert L. Bamberger
Original Assignee
Exxon Chemical Patents Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Exxon Chemical Patents Inc. filed Critical Exxon Chemical Patents Inc.
Publication of WO1996018679A1 publication Critical patent/WO1996018679A1/fr

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
    • C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
    • C08L23/04—Homopolymers or copolymers of ethene
    • C08L23/08—Copolymers of ethene
    • C08L23/0807—Copolymers of ethene with unsaturated hydrocarbons only containing four or more carbon atoms
    • C08L23/0823—Copolymers of ethene with unsaturated hydrocarbons only containing four or more carbon atoms with aliphatic cyclic olefins
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L2205/00—Polymer mixtures characterised by other features
    • C08L2205/02—Polymer mixtures characterised by other features containing two or more polymers of the same C08L -group
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L2314/00—Polymer mixtures characterised by way of preparation
    • C08L2314/06—Metallocene or single site catalysts

Definitions

  • This invention relates to metallocene catalyzed ethylene polymers which are more easily processed and exhibit superior toughness when compared to more conventional metallocene catalyzed ethylene polymers..
  • linear polyolefin homopolymers and copolymers have increased steadily since their introduction in the 1940's. Advances in linear polyolefin technology have enabled the polymers to be used in a wide variety of end-use applications. Processes used to convert these polymers into useful items including film blowing, film casting, sheet extrusion, profile extrusion, injection molding, rotomolding, compression molding, thermoforming, a variety of fiber producing processes, and the like. In the 1970's new, more economical processes for the production of linear polyolefins came into wide use.
  • improved physical properties such as lower extractables, improved sealability, better clarity, and improved strength/toughness properties, especially impact resistance, puncture, and tensile strength as compared to the traditional Ziegler-Natta and chromium catalyzed products.
  • a third processing deficiency of linear polyolefins is their relatively low melt strength which manifests itself in poor bubble stability in film blowing processes, weak parisons in blow molding processes, poor control over part thickness in thermoforming and the like when the linear polyolefins are processed at relatively high temperatures and rates.
  • polydispersity index For purposes of this application, the term PDI, and lVI ⁇ /M,. (weight average molecular weight/number average molecular weight), will be used interchangeably.
  • PDI polydispersity index
  • lVI ⁇ /M weight average molecular weight/number average molecular weight
  • Z-N and chromium catalyzed polymers generally have higher extractables, lower strength / toughness properties, higher orientation, and poorer clarity and sealabiltiy than similar metallocene-catalyzed polymers.
  • European Patent Application EP 0 124 722 A2 (US 4,586,995) describes a blend of two polymers, each having a weight average molecular weight between 120,000 and 160,000.
  • the first polymer which constitutes 40-95 weight percent of the blend, is an ethylene homopolymer or copolymer with a density >0.95 g/cc, an energy of activation (EJ ⁇ 20 kcal/mole, and a long-chain branching (LCB) frequency ⁇ 0.2 LCB / 1000 carbons.
  • the second polymer which constitutes 5-60 percent of the blend, contains 0.5-5 LCB / 1000 carbons, ⁇ 10 short-chain branches, and has an E a >35 kcal/mole.
  • Long-chain branches are defined in EP 124 722 A2 as those side branches which are sufficiently long enough to affect the molecule's hydrodynamic volume. These branches are distinguishable from “short- chain branches” which are defined in the application as containing fewer than seven carbons and do not substantially effect hydrodynamic volume. Examples of short chain branches includes groups such as methyl, ethyl, propyl, butyl, amyl, and hexyl.
  • the long chain branches in the second polymer disclosed in this document are produced by irradiation of a portion of the first polymer under non-gelling conditions in the absence of oxygen. This irradiation causes molecules with vinyl end groups or fragments from molecular scission to attach themselves to the backbone of another polymer molecule, thus forming the "Y" structures referred to.
  • These branched molecules are distinguishable from the branched molecules produced in high-pressure, free-radical polymerization processes (LDPE) by the relative level of short-chain branches in each.
  • LDPE free-radical polymerization processes
  • the Y-branched products contain fewer than one short-chain branches / 1000 carbons, the free radically polymerized products contain 10-15 short chain branches / 1000 carbons.
  • Certain embodiments of the present invention are directed to a polymer or polymer blend that satisfy the need for lower extrusion energy, while maintaining or improving most end use article mechanical properties.
  • a linear polymer typically a polyolefin
  • a linear polymer is given improved processability, substantial freedom from melt fracture and improved physical mechanical properties, by the inclusion of long-chain branching.
  • the long chain branching is found generally only on the higher molecular weight molecules in the product distribution.
  • the high molecular weight entity of the product distribution will generally have a weight average molecular weight (ML ⁇ ,) typically greater than 120,000.
  • the low molecular weight entity of the product distribution will generally have an M w less than 120,000.
  • a composition comprises an ethylene polymer having an extrusion torque less than 52 meters-gram (m-g) and a dart drop impact of at least 850 grams/mil.
  • a film is made from the composition.
  • This invention concerns certain classes of polyethylene resins, their production and articles fabricated from these resins. These resins have unique properties which make them particularly well suited for use in producing certain classes of fabricated polymeric articles. Films and blow molded articles, for instance, have combinations of properties rendering them superior to articles and films previously available for many polymeric fabricated article applications. Additionally, the resins show a surprising increase in their ability to be melt processed. Following is a detailed description of certain preferred resins within the scope of this invention, preferred methods of producing these resins, and preferred applications of these resins. Those skilled in the art will appreciate that numerous modifications to these preferred embodiments can be made without departing from the scope of the invention. For example, while the properties of resins are exemplified in film applications, they have numerous other uses. To the extent that this description is specific, this is solely for the purpose of illustrating preferred embodiments of this invention and should not be taken as limiting this invention to these specific embodiments.
  • the metallocene catalyzed materials of certain embodiments of the present invention will have generally at least two components or groups of components a higher molecular weight group of components and a lower molecular weight group of components. Such combinations can be achieved by several schemes, including blending of independently produced or polymerized materials, polymerization in sequential reactors, prepolymerization of preferably the higher molecular portion or other schemes which will be known to those of ordinary skill in the art.
  • the lower molecular weight component will generally have a MI greater than 1 dg/min; a molecular weight (M ⁇ ,) below 120,000, the preferred range is 30,000 to 120,000, preferably in the range of from 50,000 to 120,000, more preferably in the range of from 70,000 to 120,000; a density in the range of from 0.90 g/cm 3 to 0.97 g/cm 3 , preferably in the range of from 0.910 to 0.950, more preferably in the range of from 0.915 to 0.94, most preferably in the range of from 0.915 to 0.930 g/cm 3 ; an M ⁇ /M,, less than 6, preferably less than 5, more preferably than 4, most preferably less than 3; an energy of activation (EJ less than 10 kcal/mole, preferably in the range of from 6 to 10, more preferably in the range of from 6.5 to 9, most preferably in the range of from 6.5 to 8.5 kcal/mole; and a CDBI greater than 50 percent.
  • the lower molecular weight component will generally be present in the combination in the range of from 50 to 99 weight percent, preferably in the range of from 70 to 99 weight percent, more preferably in the range of from 85 to 99 weight percent, most preferably in the range of from 90 to 99 weight percent based on the total weight of the combination.
  • the higher molecular weight component will have: a MI less than 1 dg/min, preferably less than 0.5 dg/min; a molecular weight (Iv ⁇ ) greater than
  • 120,000 preferably in the range of from 120,000 to 1,000,000, more preferably in the range of from 120,000 to 500,000, most preferably in the range of from 120,000 to 250,000; a density in the range of from 0.90 g/cm 3 to 0.970 g/cm 3 , preferably in the range of from 0.90 to 0.960, more preferably in the range of from 0.900 to 0.950, most preferably in the range of from 0.900 to 0.940 g/cm 3 ; an M M n less than 6, preferably less than 5, more preferably less than 4, most preferably less than 3; a CDBI greater than 50 percent; an E a greater than 12 kcal/mole, preferably in the range of from 12 to 30, more preferably in the range of from 12 to 25, most preferably in the range of from 12 to 20 kcal per mole.
  • the higher molecular weight component will be present in the combination in the range of from 1 to 50 weight percent, preferably in the range of from 1 to 30 weight percent, more preferably in the range of from 1 to 15 weight percent, most preferably in the range of from 1 to 10 weight percent based on the total weight of the combination.
  • Both higher and lower molecular weight components will be ethylene homopolymers, ethylene- ⁇ -olefin copolymers, or combinations of homopolymers and copolymers. If one or both components are ethylene- ⁇ -olefin copolymers, terpolymners and the like, the ⁇ -olefin or ⁇ -olefins may be the same or different in the high and low molecular weight components and the level of ⁇ -olefin or ⁇ - olefins incorporation may be the same or different.
  • the ⁇ -olefin or ⁇ -olefins may be selected from those having 3 to 20 carbon atoms, preferably 4 to 10 carbon atoms, more preferably 6 to 8 carbon atoms. Most preferred ⁇ -olefins are 1-butene, 4-methyl-l-pentene, 1-hexene, 1-octene, 1-decene and mixtures thereof.
  • the ⁇ -olefin when present, will be present in the ethylene- ⁇ - olefin copolymer or copolymers in the range of from 0.2 to 10 mole percent based on the total moles of monomer and comonomer incorporated into the copolymer, preferably in the range of 0.2 to 7.5 mole percent, more preferably in the range of from 0.2 to 6.5 mole percent, most preferably in the range of from 0.2 to 5.5 mole percent.
  • Melt processing of polymers represented by certain embodiments of the present invention will generally be characterized by reduced torque or power in a given piece of extrusion equipment, at a constant output (unit of weight/unit of time) compared to other metallocene catalyzed polyolefins, and Z-N catalyzed polyolefins. While the effects will be seen in larger equipment, routine laboratory testing can exhibit the effects, for instance, in a Haake Torque Rheometer. In such a piece of equipment the torque at the conditions discussed below, the compositions will exhibit torque less than 52 m-g preferably less than 50 m-g, more preferably less than 48 m-g, most preferably less than 46 m-g.
  • Films, molded articles and the like made from these components may also include, in addition to the two aforementioned polyolefin components, other adjuvants and blend components that will be understood by those of ordinary skill in the art to be components and/or additives that may aid melt processing, prevent oxidative damage, improve specific end use properties, and the like, all without substantial negative effect on either melt processability or physical properties of the fabricated article.
  • Such films may be used as stretch films (single or multi-layer), general packaging films, bags made from such films, and the like.
  • fabricated articles include extrusion blow-molded articles, injection molded articles, thermoformed articles and the like.
  • the dart drop impact will be at least 850 g/mil, preferably at least 950 g/mil, preferably at least 1,100 g/mil, more preferably at least 1,200 g/mil, most preferably at least 1,300 g/mil.
  • One technique predicted to verify that the long chain branches are present only on the larger molecules of the invention is to first fractionate the material according to the procedure described by J. J. Watkins, et. al., in The Journal of Supercritical Fluids, 1991, 4, 24-31, and then determine the Flow Activation Energy on each fraction.
  • the fractions containing very low or no long chain branching should have the same E a as linear molecules with the same short-chain branching frequency.
  • the fractions containing long-chain branching should have a much higher E a , after correcting the data for short-chain branching frequency.
  • the molecular weight distribution of a polymer can be determined with a Waters Gel Permeation Chromatograph equipped with Ultrastyrogel columns and a refractive index detector.
  • the operating temperature of the instrument was set at 145°C, and the eluting solvent was trichlorobenzene.
  • the calibration standards included sixteen polystyrenes of precisely known molecular weight, ranging from a molecular weight of 500 to a molecular weight of 5.2 million, and a polyethylene standard, NBS 1475.
  • the refractive index detector detects polymeric molecules in the GPC effluent which have been separated based on hydrodynamic volume. The assumption is that those molecules eluting through the detector at time T x have the same molecular weight as those molecules in the linear calibration standard that elute at time T x .
  • long chain branches do not increase the hydrodynamic volume of linear molecules by an amount proportional to the length of these branches. It is believed that their contribution is only a fraction of the branch length. Therefore, if a long chain branched sample is analyzed with a refractive index detector calibrated with linear standards, the reported GPC moments will be low.
  • a low angle laser light scattering detector (LALLS), on the other hand, produces a signal which is proportional to molecular weight, rather than hydrodynamic volume. Therefore, if the long chain branched sample is analyzed with both detectors, and M ⁇ (DRI) ⁇ M ⁇ (LALLS) then than the difference between the two ML ⁇ 's is attributed to, and provides addition evidence of long chain branching. The difference in the M w 's should indicate a minimum estimate of the average branch length.
  • E a energy of activation for viscous flow.
  • the E a of linear ethylene homopolymers is approximately 6.5 kcal/mole.
  • the E a of LDPEs is typically in the range of 11-15 kcal/mole.
  • E a is independent of molecular weight and polydispersity index, but does increase with increasing comonomer content and with increasing short chain branching length.
  • Ethylene-hexene copolymers with densities greater than 0.900 contain less than 20 weight percent hexene-derived polymer units.
  • the E a of ethylene-hexene copolymers which contain less than 20 weight percent hexene-derived units is less than 8 kcal/mole. Therefore, an E a greater than 8 kcal/mole is considered indicative of long chain branching in ethylene-hexene copolymers with densities greater than 0.900 g cc.
  • E a can be determined from parallel plate oscillatory shear melt viscoelastic measurements at four different temperatures. Zero shear viscosity at each temperature is plotted vs. the reciprocal of temperature. The slope of the linear regression of this plot is equal to E a / R, where R is the gas constant, 1.987 cal/deg-mole.
  • Composition distribution is a measure of how uniformly a comonomer is distributed in a linear ethylene-based copolymer.
  • Comonomer uniformity can be determined with a Temperature Rising Elution Fractionation (TREF) procedure similar to the one described in Wild, et al., J. Poly. Sci., Poly. Phys. Ed., Vol. 20, p. 441 (1982).
  • the test result is a distribution curve which illustrates the soluble fraction (weight percent) vs. temperature.
  • the temperature scale is transformed to comonomer content using TREF data obtained with calibration standards which have very narrowly distributed, known comonomer levels.
  • compositional attribute used in this development to distinguish between polymers is the breadth of the comonomer distribution, as indicated by its Composition Distribution Breadth Index (CDBI).
  • CDBI is defined as the weight percent of the polymer molecules having a comonomer content within ⁇ 50 percent of the median total molar comonomer content.
  • Extrusion energy i.e., the energy required to extrude a polyethylene product at a standard set of conditions, is expressed either as amps or torque.
  • Screw type Single flighted, blunt tip
  • Torque requirements were determined for comparative examples 7, 9, and 12-19 at 190°C and 128 Table 2. Results are summarized in following table, and are illustrated in Figure 1.
  • Comparative Example 1 is a linear ethylene-hexene copolymer produced in a gas phase process with a silica-supported, bis(l-methyl-3-n-butyl- cyclopentadienyl) zirconium dichloride / methyl alumoxane catalyst (not available commercially).
  • M ⁇ , MI, density, and melt flow ratio are 131,000, 0.6, 0.921, and 15.9, respectively. Comparative Example 2
  • Comparative Example 2 is a blend composed of 7 weight percent Escorene
  • Escorene LD-113 is a commercially available long-chain branched ethylene homopolymer produced in a high-pressure, tubular reactor with a peroxide initiator.
  • LD-113 are 2.3 and 0.921, respectively.
  • Comparative Example 3 is a linear ethylene-hexene copolymer produced in a gas phase process with a silica-supported, bis(l-methyl-3-n-butyl- cyclopentadienyl) zirconium dichloride / methyl alumoxane catalyst (not available commercially).
  • M ⁇ ,, MI and density are 119,000, 0.83 and 0.920, respectively.
  • Comparative Example 4 is a blend composed of 3 weight percent Escorene
  • HD-7000F and 97 weight percent Comparative Example 3.
  • Escorene HD-7000F is a commercially available linear ethylene-butene copolymer produced in a series slurry process with a titanium-based Ziegler-Natta catalyst.
  • Target MI and density of the HD-7000F are 0.045 and 0.952, respectively.
  • Typical M,, of HD 7000F is > 200,000.
  • Comparative Example 5 is a blend composed of 3 weight percent Escorene HD-9856B and 97 weight percent Comparative Example 3.
  • Escorene HD-9856B is a commercially available linear ethylene-butene copolymer produced in a series slurry process with a titanium-based Ziegler-Natta catalyst.
  • Target MI and density of the HD-9856B are 0.46 and 0.956, respectively.
  • Typical M of HD 9856 B is 140,000.
  • Comparative Example 6 is a blend composed of 6 weight percent Escorene HD-9856B and 94 weight percent Comparative Example 3. Escorene HD-9856B is described in Comparative Example 5. Comparative Example 7
  • Comparative Example 7 is Escorene LL-3001.63, a commercially available linear ethylene-hexene copolymer produced in a gas phase reactor with a titanium- based Ziegler-Natta catalyst.
  • Typical M ⁇ , MI, density, and melt flow ratio are 110,000, 1.9,0.922, and 27, respectively.
  • Comparative Example 8 is a blend composed of 30 weight percent LD-113 and 70 weight percent of the resin described in Comparative Example 7. LD-113 is described in Comparative Example 2.
  • Comparative Example 9 is a linear ethylene-hexene copolymer produced in a gas phase process with a silica-supported, bis(l-methyl-3-n-butyl- cyclopentadienyl) zirconium dichloride / methyl alumoxane catalyst (not available commercially).
  • M ⁇ MI, density, and melt flow ratio are 80,000, 3.04, 0.919, and
  • Comparative Example 10 is a linear ethylene-hexene copolymer produced in a gas phase process with a silica-supported, bis(l-methyl-3-n-butyl- cyclopentadienyl) zirconium dichloride/methyl alumoxane catalyst (not available commercially).
  • M ⁇ ,, MI, density, and melt flow ratio are 80,000, 3.31, 0.919, and 17.3, respectively.
  • Examples 1, 3, 9, and 10 are prepared according to a process disclosed in WO 94/26816 inco ⁇ orated herein by reference for pu ⁇ oses of U. S. Patent practice.
  • Example 11 is a blend composed of 95 weight percent Comparative
  • Example 10 and 5 weight percent Bl which is a high molecular weight, linear ethylene-hexene copolymer and which contains linear long chain branching.
  • Bl was prepared by adding 180 psig ethylene, 8 ml hexene-1, and a mono-Cp catalyst (dimethyl(tetramethylcyclopentadienyl)cyclododecylamidosilyl titanium dichloride) with a methyl-alumoxane activator to 500 ml toluene in a 2-liter autoclave reactor.
  • the reactor temperature was relatively controlled at 90°C, and the polymerization was terminated after 15 minutes.
  • the resulting product had a density of 0.912 g/cc, an E a of 14.1 kcal mole, an M w of 206,000 (DRI detector) and 231,000 (LALLS detector), a polydispersity of 2.56 (DRI detector, uncorrected for long chain branching); and a average butyl branching content of 22 br/1000 carbons.
  • Comparative Example 12 is Escorene LL-1001,30, a commercially available linear ethylene-butene copolymer produced in a gas phase reactor with a titanium-based Ziegler-Natta catalyst. MI is 1.06 dg/min., typical density is 0.918 g/cc.
  • Comparative Example 13 is Escorene LL-3002.37, a commercially available linear ethylene-hexene copolymer produced in a gas phase reactor with a titanium-based Ziegler-Natta catalyst. MI is 1.92 dg min., typical density is 0.918 g cc.
  • Comparative Example 14 is Escorene LL- 1002.09, a commercially available linear ethylene-butene copolymer produced in a gas phase reactor with a titanium-based Ziegler-Natta catalyst. MI is 2.16 dg min., typical density is 0.918 g/cc.
  • Comparative Example 15 is Escorene LL-3003.32, a commercially available linear ethylene-hexene copolymer produced in a gas phase reactor with a titanium-based Ziegler-Natta catalyst. MI is 3.06 dg/min., typical density is 0.918 g/cc.
  • Comparative Example 16 is LD-141.87, a commercially available long- chain branched ethylene-vinyl acetate copolymer produced in a high-pressure, tubular reactor with a peroxide initiator.
  • Target MI, density, and VA content are 2.3 dg/min, 0.921 g/cc, and 2%, respectively.
  • Comparative Example 17 is LD-312.09, a commercially available long- chain branched ethylene-vinyl acetate copolymer produced in a high-pressure, tubular reactor with a peroxide initiator. MI is 1.00 dg/min., typical density and VA content are 0.927 g/cc and 4.6 weight percent, respectively.
  • Comparative Example 18 is LD-105.30, a commercially available long- chain branched polyethylene-homopolymer produced in a high-pressure, tubular reactor with a peroxide initiator. MI is 2.00 dg/min., typical density is 0.925 g/cc.
  • Comparative Example 19 is LD-306.09, a commercially available long- chain branched ethylene-vinyl acetate copolymer produced in a high-pressure, tubular reactor with a peroxide initiator. MI is 2.00 dg/min., typical density and VA content are 0.926 g/cc and 5.5 weight percent, respectively.
  • Polyethylene products may be distinguished from each other by, for instance, their processability and their end-use properties. These attributes may be predicted by, among other things, the catalyst and process used to produce the product, (which define the product's molecular weight and comonomer distributions), and on the product's melt index, density, and comonomer type. Blending different products together allows converters to combine certain advantages of the individual blend components.
  • One combination which has been quite popular since linear polyethylenes (Z-N and/or chromium catalyzed) were first introduced is LLDPE plus LDPE, with the LLDPE content generally >70 weight percent.
  • LLDPEs can be drawn down to relatively thin gauges, and have higher modulus and significantly better strength/toughness properties than LDPEs.
  • LLDPEs have lower melt strength, require more extrusion energy, and are hazier than LDPEs.
  • LDPEs on the other hand, have higher melt strength and good clarity. The combination succeeds in improving LLDPE's melt strength and clarity, while retaining LLDPE's good drawability, but generally does not improve LLDPE's extrusion energy or mechanical properties.
  • Certain blend ratios e.g., 70- 80 percent LLDPE / 20-30 percent LDPE, are antagonistic relative to dart impact and tear resistance, i.e., the dart and tear of the blend is generally poorer than either the blend components by themselves.
  • Bl is a 0.912 g/cc density, linear ethylene-hexene copolymer with a relatively high molecular weight and an E a of 14 kcal/mole. Details of its preparation appear in Example 1 1.
  • the present invention is distinguishable from known polyethylenes on the basis of the nature and positioning of the long chain branches, and on the combination of reduced extrusion energy and substantially enhanced film impact resistance.
  • the long chain branches are of sufficient length, frequency, and intramolecular position to produce a component with an E a greater than 12 kcal/mole. They are more compatible with the linear blend component, and produces the appropriate solid state thermoplastic networks to deliver enhanced mechanical properties.
  • the ethylene copolymers described herein may be made from ethylene and an alpha-olefin where the alpha-olefin has in the range of from 4 to 20 carbon atoms, preferably in the range of from 4 to 10 carbon atoms, most preferably in the range of from 4 to 8 carbon atoms.
  • the choice of comonomer for the lower molecular weight component and the higher molecular weight component can be based on having the same alpha-olefin as the comonomer or different alpha-olefins as comonomers (for instance, lower molecular weight material may have a butene comonomer, the higher molecular weight material may have an octene comonomer).
  • the level of comonomer inco ⁇ oration in the members of the combination may be same or may be different. In general the range of comonomer inco ⁇ oration in copolymers described by an embodiment of the present invention are dependent on the type of comonomer.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
  • Compositions Of Macromolecular Compounds (AREA)
  • Manufacture Of Macromolecular Shaped Articles (AREA)

Abstract

Cette invention concerne des polyoléfines linéaires et plus spécifiquement des polymères d'éthylène qui possèdent des propriétés de mise en ÷uvre améliorées par rapport aux polyéthylènes linéaires connus jusqu'à présent. Pour améliorer l'aptitude de mise en ÷uvre, on introduit un constituant présentant une masse molaire (Mw) élevée, à savoir, supérieure à 120 000 dans un constituant à masse molaire (Mw) plus faible, à savoir, inférieure à 120 000. Le constituant à masse molaire élevée possède une ramification à chaîne longue. L'aptitude de mise en ÷uvre améliorée se manifeste par une plus grande sensibilité au cisaillement du polymère ou du mélange polymère, ce qui a pour effet de réduire la puissance et le couple nécessaire pour extruder ces polymères. En outre les propriétés physiques telles que la résistance à l'impact d'une flèchette ne sont pas négativement modifiées par l'incorporation du constituant à masse molaire plus élevée et peuvent donc être améliorées.
PCT/US1995/016534 1994-12-16 1995-12-18 Compositions de polyethylene a aptitude de mise en ×uvre amelioree et presentant des proprietes physiques ameliorees WO1996018679A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US35812594A 1994-12-16 1994-12-16
US08/358,125 1994-12-16

Publications (1)

Publication Number Publication Date
WO1996018679A1 true WO1996018679A1 (fr) 1996-06-20

Family

ID=23408405

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1995/016534 WO1996018679A1 (fr) 1994-12-16 1995-12-18 Compositions de polyethylene a aptitude de mise en ×uvre amelioree et presentant des proprietes physiques ameliorees

Country Status (1)

Country Link
WO (1) WO1996018679A1 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998026000A1 (fr) * 1996-12-12 1998-06-18 The Dow Chemical Company Compositions interpolymeres et film etirable coule produit a partir de celles-ci
US6812289B2 (en) 1996-12-12 2004-11-02 Dow Global Technologies Inc. Cast stretch film of interpolymer compositions
WO2007008361A1 (fr) * 2005-07-11 2007-01-18 Equistar Chemicals, Lp Compositions de polyethylene
CN116063598A (zh) * 2018-09-17 2023-05-05 切弗朗菲利浦化学公司 改性负载型铬催化剂和由其生产的基于乙烯的聚合物

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0274536A1 (fr) * 1986-07-04 1988-07-20 Mitsui Petrochemical Industries, Ltd. Composition a base de polyolefine pour le moulage par injection
US5210142A (en) * 1992-02-13 1993-05-11 The Dow Chemical Company Reduction of melt fracture in linear polyethylene

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0274536A1 (fr) * 1986-07-04 1988-07-20 Mitsui Petrochemical Industries, Ltd. Composition a base de polyolefine pour le moulage par injection
US5210142A (en) * 1992-02-13 1993-05-11 The Dow Chemical Company Reduction of melt fracture in linear polyethylene

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
ABRAHAM D ET AL: "STUDIES ON LDPE/LLDPE BLENDS", ANGEWANDTE MAKROMOLEKULARE CHEMIE, vol. 200, 1 September 1992 (1992-09-01), pages 15 - 25, XP000305374 *
MASHUKOV N I: "PROPERTIES OF BLENDS OF HIGH-DENSITY POLYETHYLENES WITH DIFFERENT MOLECULAR MASS CHARACTERISTICS", INTERNATIONAL POLYMER SCIENCE AND TECHNOLOGY, vol. 18, no. 10, 1 January 1991 (1991-01-01), pages T67 - T68, XP000249219 *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998026000A1 (fr) * 1996-12-12 1998-06-18 The Dow Chemical Company Compositions interpolymeres et film etirable coule produit a partir de celles-ci
US6812289B2 (en) 1996-12-12 2004-11-02 Dow Global Technologies Inc. Cast stretch film of interpolymer compositions
WO2007008361A1 (fr) * 2005-07-11 2007-01-18 Equistar Chemicals, Lp Compositions de polyethylene
CN116063598A (zh) * 2018-09-17 2023-05-05 切弗朗菲利浦化学公司 改性负载型铬催化剂和由其生产的基于乙烯的聚合物

Similar Documents

Publication Publication Date Title
JP6759263B2 (ja) 高い溶融強度を有する低密度エチレン系ポリマー
EP1333044B1 (fr) Film avec une resistance au choc elevée
KR100654593B1 (ko) Ｅｓｃｒ-강성 관계와 팽윤비가 개선된 폴리에틸렌 성형배합물, 이의 제조방법 및 이의 용도
EP1546252B1 (fr) Compositions de polyethylenes pour moulage par injection
EP0095253B1 (fr) Mélange à base de polyéthylène et pellicule
KR101768245B1 (ko) 성형 조성물
EP1937769B1 (fr) Composition
US5102955A (en) Broad distribution, high molecular weight low density polyethylene and method of making thereof
JP2004502852A (ja) エチレンインターポリマーブレンド
EP0808854B1 (fr) Resine de polyethylene, tuyau et joint pour tuyau fabriques avec cette resine
KR20090014329A (ko) 고밀도 폴리에틸렌 조성물, 이의 제조 방법, 이로부터제조된 물품, 및 이러한 물품의 제조 방법
EP0789726B1 (fr) Composition de moulage, procede d'elaboration, procede de moulage et articles moules
KR20100014214A (ko) 고-밀도 폴리에틸렌 조성물, 그의 제조 방법, 그로부터 만들어진 사출 성형 물품, 및 이러한 물품의 제조 방법
EP2994506A1 (fr) Polyéthylène haute densité
MX2014007930A (es) Composiciones de resina mejoradas para revestimiento por extrusion.
US5210142A (en) Reduction of melt fracture in linear polyethylene
EP1884527B1 (fr) Résine de polyéthylène, son procédé de fabrication, et tuyau et joint comprenant la résine
EP1819770B1 (fr) Composition de polyethylene multimodale pouvant etre obtenue avec un catalyseur a activite elevee
EP1461197A1 (fr) Individualisation par oxygene de resines de polyethylene
JP2004517196A (ja) 高収縮性ポリエチレンフィルム
WO1996018679A1 (fr) Compositions de polyethylene a aptitude de mise en ×uvre amelioree et presentant des proprietes physiques ameliorees
AU5030499A (en) Polyethylene compositions having improved mechanical properties and improved processability in the melted state
US6248840B1 (en) Process to produce a composition
KR20040070242A (ko) 에틸렌-알파-올레핀 상호중합체 필름의 제조 방법
EP1650233A1 (fr) Composant catalytique comprenant au moins trois composés métallocènes bisindényl pontés

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): CA

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FR GB GR IE IT LU MC NL PT SE

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
121 Ep: the epo has been informed by wipo that ep was designated in this application
122 Ep: pct application non-entry in european phase
NENP Non-entry into the national phase

Ref country code: CA

点击 这是indexloc提供的php浏览器服务，不要输入任何密码和下载