CA2161093A1 - Elastic polyethylene compositions - Google Patents
Elastic polyethylene compositionsInfo
- Publication number
- CA2161093A1 CA2161093A1 CA 2161093 CA2161093A CA2161093A1 CA 2161093 A1 CA2161093 A1 CA 2161093A1 CA 2161093 CA2161093 CA 2161093 CA 2161093 A CA2161093 A CA 2161093A CA 2161093 A1 CA2161093 A1 CA 2161093A1
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- CA
- Canada
- Prior art keywords
- weight
- polyethylene
- density
- low density
- composition
- Prior art date
- Legal status (The legal status 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 status listed.)
- Abandoned
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
- C08J5/18—Manufacture of films or sheets
-
- 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
- C08L23/06—Polyethene
-
- 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 more than three carbon atoms
- C08L23/0815—Copolymers of ethene with aliphatic 1-olefins
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2323/00—Characterised by the use of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Derivatives of such polymers
- C08J2323/02—Characterised by the use of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Derivatives of such polymers not modified by chemical after treatment
- C08J2323/04—Homopolymers or copolymers of ethene
-
- 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
- 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
- C08L2205/025—Polymer mixtures characterised by other features containing two or more polymers of the same C08L -group containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L2207/00—Properties characterising the ingredient of the composition
- C08L2207/06—Properties of polyethylene
- C08L2207/068—Ultra high molecular weight polyethylene
Abstract
Polyethylene compositions exhibiting varying degrees of crystalline-amorphous regions are disclosed. Such materials are obtained by combining high molecular weight homopolymer polyethylene chains (Mw greater than or equal to about 15 x 106) with conventional polyethylene polymers, such as low density, linear low density, and high density. Blend compositions in accordance with the invention exhibit non-linear elongational characteristics, due to enhanced elasticity, and are particularly suitable for film blowing and associated applications such as oriented and non-oriented packaging films and molding applications.
Description
WO ~N~ 2 1 6 1 0~9 3 ~CT~4/0l639 ELASTIC POLYETHYLENE COMPOSITIONS
Technical Field This invention relates to polyethylene blend compositions comprising one or more of conventional polyethylene polymers or copolymers, with additionally, high molecular weight polyethylene (Mw greater than 1.5x106), the blend compositions exhibiting enhanced elastic properties.
Background of the Invention The level of elasticity in polyethylene films is a critical property for both of film production speed and coating speed. For example, during the film blowing operation conventionally used, the bubble stability is controlled by the elasticity of the (partially melted) film as it is being stretched, cooled and picked up by the chill and take-up rolls. Additionally, the elastic properties are important in molding applications for both of processing and composition final properties.
Certain polyethylene blends comprising both of high Mw polyethylene and one or more conventional polyethylene polymers or copolymers are known- in the patent art, typically 'or injection molding compositions. This is because ultrahigh molecular weight polyethylenes are known to have exceptional abrasion and impact resistance.
An early description of molded polyethylene compositions, JP-A-59-232164, disclosed the use of A) 50 - 15 parts superhigh molecular weight polyethylene, having an intrinsic viscosity [~] in decalin at 135~C of at least 5 dl/g and a density of 0.930 g/cm3 or more, and b) 50 - 85 parts high-density polyethylene, having a density of 0.950 or more and and MFR of 0.1-500 g/lOmin, for the purpose of providins a latent-heat-type thermal energy material said to show excellent shape retention when being melted. The methods of production are said to include both i) mixing WO94/2~K4 ~ 6 ~ 9 PcTe~4/0l639 with melt-kneading and extrusion into pellets, st-ands, 'ilms, sheets, or nets and b) mixing with forming into strands or sheets by an injection or compression process.
vS-h-4 792 588 describes ethylene compositions said IO have excellent melt moldability comprising ~0 - g5 wt.~
ultrahigh-molecular-weight polyethylene with molecular weight of at least 1,650,000 and 80 - 5 w~.~ of a low-l ) molecular-weight to high molecular-weight ~olyethylene of about 1500 to about 360,000. The composit~ons are produced by a multi-stage, multi-reactor process. The mecnanical properties of high impact resistance or strength and ensile strength of the ultrahigh-molecular-weight polyethyiene is said tO be retained. Molàed produc~s are described, ncluding molded sheets of 2 - 5 mm. thic~.ness.
:iigh speed-formed, thin films of a thic}ness up to 6 microns ana mouldings from compositions comprising 85 - 50 wt.-j A) polyethylene compositions consisting of a broad ratio of low mol. wt. PE ( mol. wt. 5,000 - 50,000) and high mol. Wt. PE ( mol. wt. 100,000 - 1,500,000) and, 15 -50 wt.~ B) polyethylene having mol. wt. 90,000 - 500,000 are described in an Abstract of JP-A-0 026 049.
_nhanced elast city properties are not directly addressed in the above published documents, nor are morphoiogical characteristics described that would lead directly to development of the improved elasticity compositions that are the subject of the claimed invention.
Invention Disclosure It has been surprisingly found that by combining high weight-average molecular weight polyethylene (Mw greater -han about 1.5 x 106) with conventional polyethylene polymers, polyethylene compositions exhibiting varying degrees of crystalline-amorphous regions can be prerared.
WO ~U~ 3 These blenà compositions exhibit non-linear elongational characteristics, due to enhanced elasticity, and accordingly are particularly suitable for film blowing and associated applications such as orlented and non-oriented packaging films.
, ~
3est Mode and Examples of the Invention ~-, The high weight-average molecular-weight polyethylene (HMWPE) of the invention are those polyethylenes which have a Mw greater than or equal to about 1.5 x 106. Included are ~he ultrahigh molecular-weight ("UHMW") polyethylenes ~ef ned by 'he ASTM as ~hose linear polyethylenes which ^ave a relazive viscos t i sf 2.3 or greater, at a sclution concentrat_sn of 0.05~, at 135C., in decahydronaphthalene.
Typically ;DPE has molecular weights in the range of 100,000 to 200,000, and HMW HDPE has molecular weights in the range of 300,000 to 500,000 (see below). The high moiecular weight homopolymer polyethylene of the invention is substantially higher in Mw, and will typically be on the or~er of 1.5 x 106, or higher. Commercial grades are available f-om 3 x 106 to 6 x 106, normally in powder form.
Ty- cally he HMWPE can be prepared by any of radical polymerization of ethylene under high pressure, coordination polymerization of ethylene, and polymerization of ethylene with supported metal-oxide catalysts, preferably and, generally commercially, by means of the latter two. Additional background information on UHMW
appears in the technical literature, see e.g., Ency. of Doly. Sci. and Eng., vol. 6, pp. 490-494 and 383-490 (J.
Wiley & Sons, 1986), and Textbook of Polymer Science (3d ed.), F.W. 3illmeyer, Jr., Pages 366-367 ( J. Wiley & Sons, 1984).
W094/~ ~i 610 9 3 PCT~4/01639 The term "conventional polyethylene polymers" includes one or more of ultralow-density ("ULDPE"), very low density "'~LDPE"), low density ("LDPE"), linear low density ~"LL~?E"), high density ("HDPE"), and high molecular weight ;-igh-aensity ("HMW HDPE") as those terms are understood in .he ârt, see e.g., Ency. of Poly. Sci. and Eng., above, and Modern Plastics Encyclopedia (1988). Both~homopolymers and copolymers are included, the polyethyi~ene copolymers typically are those of ethylene with at least one alphaolefin having at least three carbon atoms, e.g., propylene, l-butene, l-hexene, l-octene, etc. Additionally these blends will encompass any of the polyethylene polymers and blends emerging from new technologies relating ~o -.etallocene coordination catalysis, such as those exempiifiec in PCT-A-WO 90/03414. The aisclosures addressing polyolefins and blends thereof in U.S.
application number U.S. application Ser. No. 252,094 filed 30 September 1988 and U.S. application Ser. No. 07/817,701 filea 7 January 1992 are incorporated by reference for purposes of U.S. patent practice.
Typically the invention blends comprise from 0.1 to 40 wt.~
based upon the total polymer weight, more particularly 2 to less Ihan 40 wt.~ of the HMWPE of the invention. The complement will comprise the conventional polyethylene polymers or copolymers. Additionally, as with other polyolefin blends, additives such as reinforcing fillers, pigments or colorants, W stabilizers, antioxidants, anti-block or slip agents, etc., can be provided in conventional amounts in accordance with conventional methods to achieve specifically desired end properties. Such additi~es can be added in any order convenient prior to or during melt blending of the blends.
31enas of the invention are prepared by blending the descr bed components in the desired proportions using either conventional solution or melt processing techniques W094/~ 21610 9 3~ PCT~4/01639 .~ .
and apparatus for example, solution-melt extruders, Banbury mixers, single or multiple screw extruders and the like.
The ultra high molecular weight polyethylene by itself is known to be be difficult to process via conventional polyethylene processing techniques. However it can be successfully processed by a newly developed but well established technique called gel spinning. Exceptionally high strength highly extended polyethylene fibers are produced by this technique. Similarly, they are processed in the solid-state by sintering and extrusion, a technique analogous to injection extrusion processes used for manufacturing pipes or plastics or ceramics. The techniques are known to those familiar with field of polyolefin processing. Any such technique could be used for preparing the said composition disclosed herein.
Alternatively, blends may be made by direct polymerization, using, for example, two or more catalysts in a single reactor or one or more catalysts in parallel or series reactors, where the catalysts, monomer feeds, and reactor conditions are provided that are suitable for the preparation of polymer components meeting the invention description. Such direct polymerization blends are well-known in the polyolefin art, see e.g., US-A-4 792 588.
Though not intended as a limitation on the invention as described, it is believed that there is synergistic formation of morphology having crystallite structure and associated amorphous regions such that surprisingly high elongations are achieved. Measurement by DSC (differential scanning calorimetry) showed that blends of conventional polyethylene polymer (LD-180 of Exxon Chemcal Belgium, M.I.
Technical Field This invention relates to polyethylene blend compositions comprising one or more of conventional polyethylene polymers or copolymers, with additionally, high molecular weight polyethylene (Mw greater than 1.5x106), the blend compositions exhibiting enhanced elastic properties.
Background of the Invention The level of elasticity in polyethylene films is a critical property for both of film production speed and coating speed. For example, during the film blowing operation conventionally used, the bubble stability is controlled by the elasticity of the (partially melted) film as it is being stretched, cooled and picked up by the chill and take-up rolls. Additionally, the elastic properties are important in molding applications for both of processing and composition final properties.
Certain polyethylene blends comprising both of high Mw polyethylene and one or more conventional polyethylene polymers or copolymers are known- in the patent art, typically 'or injection molding compositions. This is because ultrahigh molecular weight polyethylenes are known to have exceptional abrasion and impact resistance.
An early description of molded polyethylene compositions, JP-A-59-232164, disclosed the use of A) 50 - 15 parts superhigh molecular weight polyethylene, having an intrinsic viscosity [~] in decalin at 135~C of at least 5 dl/g and a density of 0.930 g/cm3 or more, and b) 50 - 85 parts high-density polyethylene, having a density of 0.950 or more and and MFR of 0.1-500 g/lOmin, for the purpose of providins a latent-heat-type thermal energy material said to show excellent shape retention when being melted. The methods of production are said to include both i) mixing WO94/2~K4 ~ 6 ~ 9 PcTe~4/0l639 with melt-kneading and extrusion into pellets, st-ands, 'ilms, sheets, or nets and b) mixing with forming into strands or sheets by an injection or compression process.
vS-h-4 792 588 describes ethylene compositions said IO have excellent melt moldability comprising ~0 - g5 wt.~
ultrahigh-molecular-weight polyethylene with molecular weight of at least 1,650,000 and 80 - 5 w~.~ of a low-l ) molecular-weight to high molecular-weight ~olyethylene of about 1500 to about 360,000. The composit~ons are produced by a multi-stage, multi-reactor process. The mecnanical properties of high impact resistance or strength and ensile strength of the ultrahigh-molecular-weight polyethyiene is said tO be retained. Molàed produc~s are described, ncluding molded sheets of 2 - 5 mm. thic~.ness.
:iigh speed-formed, thin films of a thic}ness up to 6 microns ana mouldings from compositions comprising 85 - 50 wt.-j A) polyethylene compositions consisting of a broad ratio of low mol. wt. PE ( mol. wt. 5,000 - 50,000) and high mol. Wt. PE ( mol. wt. 100,000 - 1,500,000) and, 15 -50 wt.~ B) polyethylene having mol. wt. 90,000 - 500,000 are described in an Abstract of JP-A-0 026 049.
_nhanced elast city properties are not directly addressed in the above published documents, nor are morphoiogical characteristics described that would lead directly to development of the improved elasticity compositions that are the subject of the claimed invention.
Invention Disclosure It has been surprisingly found that by combining high weight-average molecular weight polyethylene (Mw greater -han about 1.5 x 106) with conventional polyethylene polymers, polyethylene compositions exhibiting varying degrees of crystalline-amorphous regions can be prerared.
WO ~U~ 3 These blenà compositions exhibit non-linear elongational characteristics, due to enhanced elasticity, and accordingly are particularly suitable for film blowing and associated applications such as orlented and non-oriented packaging films.
, ~
3est Mode and Examples of the Invention ~-, The high weight-average molecular-weight polyethylene (HMWPE) of the invention are those polyethylenes which have a Mw greater than or equal to about 1.5 x 106. Included are ~he ultrahigh molecular-weight ("UHMW") polyethylenes ~ef ned by 'he ASTM as ~hose linear polyethylenes which ^ave a relazive viscos t i sf 2.3 or greater, at a sclution concentrat_sn of 0.05~, at 135C., in decahydronaphthalene.
Typically ;DPE has molecular weights in the range of 100,000 to 200,000, and HMW HDPE has molecular weights in the range of 300,000 to 500,000 (see below). The high moiecular weight homopolymer polyethylene of the invention is substantially higher in Mw, and will typically be on the or~er of 1.5 x 106, or higher. Commercial grades are available f-om 3 x 106 to 6 x 106, normally in powder form.
Ty- cally he HMWPE can be prepared by any of radical polymerization of ethylene under high pressure, coordination polymerization of ethylene, and polymerization of ethylene with supported metal-oxide catalysts, preferably and, generally commercially, by means of the latter two. Additional background information on UHMW
appears in the technical literature, see e.g., Ency. of Doly. Sci. and Eng., vol. 6, pp. 490-494 and 383-490 (J.
Wiley & Sons, 1986), and Textbook of Polymer Science (3d ed.), F.W. 3illmeyer, Jr., Pages 366-367 ( J. Wiley & Sons, 1984).
W094/~ ~i 610 9 3 PCT~4/01639 The term "conventional polyethylene polymers" includes one or more of ultralow-density ("ULDPE"), very low density "'~LDPE"), low density ("LDPE"), linear low density ~"LL~?E"), high density ("HDPE"), and high molecular weight ;-igh-aensity ("HMW HDPE") as those terms are understood in .he ârt, see e.g., Ency. of Poly. Sci. and Eng., above, and Modern Plastics Encyclopedia (1988). Both~homopolymers and copolymers are included, the polyethyi~ene copolymers typically are those of ethylene with at least one alphaolefin having at least three carbon atoms, e.g., propylene, l-butene, l-hexene, l-octene, etc. Additionally these blends will encompass any of the polyethylene polymers and blends emerging from new technologies relating ~o -.etallocene coordination catalysis, such as those exempiifiec in PCT-A-WO 90/03414. The aisclosures addressing polyolefins and blends thereof in U.S.
application number U.S. application Ser. No. 252,094 filed 30 September 1988 and U.S. application Ser. No. 07/817,701 filea 7 January 1992 are incorporated by reference for purposes of U.S. patent practice.
Typically the invention blends comprise from 0.1 to 40 wt.~
based upon the total polymer weight, more particularly 2 to less Ihan 40 wt.~ of the HMWPE of the invention. The complement will comprise the conventional polyethylene polymers or copolymers. Additionally, as with other polyolefin blends, additives such as reinforcing fillers, pigments or colorants, W stabilizers, antioxidants, anti-block or slip agents, etc., can be provided in conventional amounts in accordance with conventional methods to achieve specifically desired end properties. Such additi~es can be added in any order convenient prior to or during melt blending of the blends.
31enas of the invention are prepared by blending the descr bed components in the desired proportions using either conventional solution or melt processing techniques W094/~ 21610 9 3~ PCT~4/01639 .~ .
and apparatus for example, solution-melt extruders, Banbury mixers, single or multiple screw extruders and the like.
The ultra high molecular weight polyethylene by itself is known to be be difficult to process via conventional polyethylene processing techniques. However it can be successfully processed by a newly developed but well established technique called gel spinning. Exceptionally high strength highly extended polyethylene fibers are produced by this technique. Similarly, they are processed in the solid-state by sintering and extrusion, a technique analogous to injection extrusion processes used for manufacturing pipes or plastics or ceramics. The techniques are known to those familiar with field of polyolefin processing. Any such technique could be used for preparing the said composition disclosed herein.
Alternatively, blends may be made by direct polymerization, using, for example, two or more catalysts in a single reactor or one or more catalysts in parallel or series reactors, where the catalysts, monomer feeds, and reactor conditions are provided that are suitable for the preparation of polymer components meeting the invention description. Such direct polymerization blends are well-known in the polyolefin art, see e.g., US-A-4 792 588.
Though not intended as a limitation on the invention as described, it is believed that there is synergistic formation of morphology having crystallite structure and associated amorphous regions such that surprisingly high elongations are achieved. Measurement by DSC (differential scanning calorimetry) showed that blends of conventional polyethylene polymer (LD-180 of Exxon Chemcal Belgium, M.I.
2.0 (190C., 2.16 kg)) and ultra-high molecular weight polyethylene (GUR-412 of Hoechst Aktiengesellschaft, DE;
weight-average M.W. 2 x 106), exhibited not only phases of the two individual components, but also a third phase having a distinct melting temperature Tm. Thus, for example, a binary blend of these polymers in the ratio of wog4n~x~ 21 610 9 ~ PCT~W4/0l639 90/10 showed three melting endotherms at 10 , 124 and i33C
indicating three different kinds of crystalline lamellae populations. This is contrary to the published literature, see for example J. Polym. Sci., Phys. Ed., 25, 89 (1987) and Polymer, _, 426 (1991). Here it is ciearly men~ioned .hat the basic crystalline structure of either com?onent does not change during mixing, and upon cooling the melt of ;. ,.D~
blend of such polymers, the respec~ive crystalline structure of the components is retaine~. These published works clearly mention that only in ~certain cases, for example in blends of HDPE and LLDPE both having nominal molecular weights in the range of 50-100,000, does co-c-ystallization take place. The presently discoverea novel behavior of the Dlend demonstrated the existence ~f at east three types of c_ystalline phase st-lctures :-. the blends of said materials composition of blends of LD?E and UHMWPE.
The mechanisms by which the elongation of conventional polyethylene increases upon the addition of very long molecular weight polyethylene chains was not readily apparent. However the phenomenon is obtained in cases where the ratio of the molecular we-ight of conventional and high molecular weight polyethylene (''MC/MH''~ is preferably less than 1; more preferably less than 0.1 anc most preferably less than 0.01. In other words, the MC/MH, where MH is the molecular weight of UHMWPE and MC s the conventional polyethylene is such that MH/MC > 1; more preferably MH/MC > 10 and most preferably > 25. Note MH in examples 2-10 below is about 2,000,000 and Mc is 60,000.
~hus MH/MC is about 35.
Typical industrial applications for the blends cf the invention are the field of polyolefin films, especially in .hin guage films where strength and elasticity are important t~ fast processlng. The blends exhibit excellent bubble stability and fast drawdowns during film blowing W094~8~ ~ PCT~4/01639 -operations. All of unoriented and singly, or doubly, oriented packaging films for such end-use as food, health care or consumer articles enclosures can be prepared from the blends of this invention in accordance with conventional knowledge in the field. Additionally the invention blends are suitable for injection molding purposes. Items that are normally injection molded such as mechanical goods, household utensils, toys, etc. which use polyethylenes as such or polyethylene compositions incorporating polypropylene and/or ethylene-propylene copolymers, can be made from the disclosed compositions described in this invention.
ml he following examples are presented to illus~rate the foregoing discussion. All parts, proportions and percentages are by weight unless otherwise indicated.
Although the examples may be directed to certain embodiments of the present invention, they are not to be viewed as limiting the invention in any specific respect.
Examples 1 to 11 - Invention blend compositions of a commercial high density polyethylene (HDPE - 6950 YN, a product of Exxon Chemical Co., U.S.A.) and a commercial high density and ultrahigh molecular weight polyethylene (GUR-412 - Lot CM 331584, Hoechst Aktiengesellschaft, DE) were made. The weight-average molecular weight of the former as determined by GPC (gel permeation chromatography) was 62,000 and its Mw/Mn ratio about 4.6. Its melting temperature determined from DSC @ 10C/min was found to be 137.4C and room temperature density as determined by the standard ASTM D-1505 (equivalent DIN-53479D Iso-R-1183D) procedure was found to be 0.96 (g/cm3). Similarly, the weight-average molecular weight of UHMWPE was about 2,000,000 and its Mw/Mn ratio greater than 5Ø Its melting temperature and density values were 133.5 and 0.93 (g/cm3), respectively. The blend compositions were made by dissolving the appropriate quantities of the material in W094/~0~ 21610 9 3 : PCT~4/01639 _ hot xylene at 130C for at least 2 hours with constant mechanical stirring or occasional hand shaking of the flask. An oxidant (2,6-di-tert-butyl-p-creosol ("DBPC", Fluka A.G., Germany) in the amount 0.1 to 0.2 wt ~ was added in the solution to avoid any potential degradation of the polyethylenes. The nominal compositions of series of blends made under this series of experimén`ts are shown in Table-1 below.
At lower concentration of high molecular weight polyethylene, mechanical stirring was readily feasible.
However, at higher concentrations the solution required that they be mildly shaken as the mechanical stirring became difficult due to the observation that solution began to climb up the rod with agitation. In such cases occasional hand shaking of the flask was done to facilitate the dissolution of polymer. After the two polymers were homogeneously mixed, the solution was poured into an aluminum tray. The solvent was let evaporate under an evacuation hood for number of days, usually for 7-10 days.
After bulk of the solvent was removed, the final drying of the material was carried out in a vacuum oven (- 70C) for about 24-48 hours. Subsequently, the material was compression molded into thin sheets of about 1 mm in thickness @ 170-240C with 50-150 bars of pressure.
Dumbell specimens were cut from these sheets and following standard ASTM-D-638M ~equivalent to DIN-53457 Iso-R-527) tensile testing method, room temperature mechanical properties were evaluated. Reported values are of the average values of 3-5 measurements of equivalent samples.
W094/~ 21 610 9~3 ~ " PCT~4/01639 Table-1 Mechanical Properties of Blends of HDPE and UHMWPE
F.Y-~rle Nominal Composition Stress at Elongation (number, #) (HDPE/UHMWPE) Break at Break (MPa) (%) 1* ` ~100/0 21.5 125 2 99.9/0.1 23.2 398 3 99.8/0.2 22.7 609 4 99.5/0.5 20.7 214 99/1 21.4 245 6 98/2 20.3 419 7 95/5 19.8 909 8 90/10 19.7 477 9 80/20 39.4 939 60/40 44.2 708 11 * 0/100 52.9 536 * comparative examples s It is noted from column 3 and 4 where the tensile strength at break and elongation at break data are shown, that the blend compositions containing ultra-high molecular weight polyethylene have dramatically large elongations as compared to the pure HDPE (1) , and greater elongations than those to be expected from an average of the contributions of the HDPE and the UHMWPE (1,11). Thus, for example, example # 2 which contains only 0.1 % of the UHMWPE, exhibits elongation which is larger by a factor of at least 3 (i.e. more than 300 %) over the pure HDPE, while there is only a minor change in its tensile strength.
Similarly, example # 6 when 2 ~ of the UHMWPE is incorporated, elongation of the HDPE increases by about 700 % with simultaneous increase in the tensile strength of HDPE by nearly 100 %.
Example 12 - For illustrative and comparison purposes, polyethylene blends incorporating long chains were also W094/~064 21 61 0 9 3 PCT~P94101639 made by melt mixing. Generally speaking, the melt mixing and processing of very high molecular weight is not readily feasible at the conventional temperatures and torques available in laboratory scale units such as Brabender extruder. However, compositions containing up`to 5 wt ~ of the UHMWPE were found to be capable of effecti~ mixing and thus melt mixed in a Brabender mixer at 240~-C. These were subsequently extruded in the form of -~strip using a rectangular die of opening of 25 mm in width and 2.5 mm in thickness. A Haake model PL-2000-6 single-screw extruder with four heating zones each set nominally at 220C was used. Dumbbell specimens from the center portion of the extruded strip were cut for tensile measurements. Results obtained from the melt mixed materials compared to those obtained from solution matched satisfactorily and were within the experimental error of typical tensile tests, i.e. within 10 ~.
Examples 13 to 19 - Mechanical data evaluated for of blends of linear low density polyethylene with high molecular weight polyethylene are exemplified in Table-2. An LLDPE
SLP-4-2219 sold by Exxon Chemical Co., U.S.A., was used.
The SLP-4-2219 is a linear copolymer of ethylene and butene. Its weight average molecular weight was about 26,000 and Mw/Mn ~ 2.0, butene content ~ 8.7 wt ~1 and density of about 0.91 (g/cm3). DSC measurement provided a Tm value of about 103.4C. Blend preparation and testing was as described for Examples 1 to 11. For this series of blends MH/MC was about 75.
W094/~0~ 21610 9 3 ; PCT~4/01639 Table-2 Mechanical Properties of Blends of LLDPE and UHMWPE
ExampleNominal Composition Stress at Elongation (number, ~LLDPE/VHMWPE) Break at Break #) (MPa) (%) 13* 100/0 8.4 81 14 99/1 8.1 63 98/2 8.1 83 16 95/5 9.2 157 17 90/10 11.5 656 18 80/20 11.4 685 19 60/40 24.8 849 11* 0/100 52.9 536 * comparative examples It is clear from the data shown in above Table-2, that compositions containing less than about 5 wt.~ high molecular weight species dramatically enhanced the elongational properties of SLP-4-2219. Thus for example it is noted at 10-20 ~ of HMWPE that both the tensile strength (stress at break) and elongation at break increase. The former by about 30 ~ and the latter by more than 800 ~, respectively.
Examples 20 and 21 - Mechanical data evaluated for of blends of another linear low density polyethylene with the HMWPE of Examples 13 to 20 are exemplified in Table-3. An LLDPE Exxact3 3010C sold by Exxon Chemical Co., U.S.A., was used. This LLDPE is a linear copolymer of ethylene and butene having weight average molecular weight of about 78,000 and Mw/Mn ~ 2.0, butene content ~ 14 wt ~ and density of about 0.90 (g/cm3). DSC measurement provided a Tm value of about 91C. Blend preparation and testing was as described for Examples 1 to 11. For this series of blends MH/MC was about 25.
WO94/2WK~ 21610 9 3 PCT~4/01639 Table-3 M~ ni cal Properties of Blends of LLDPE and UHMWPE
F~a~rleNominal Composition Stress at Elongation (number,(LLDPE/HMWPE) Break at Break #) (MPa) ` ~ (%) 20* 100/0 25.1 ~-; 864 21 95/5 27.5 ;~ 946 11 0/100 52.9 536 * comparative examples Table-3 illustrates the significant enhancement of elongation when of another LLDPE-based composition contains the HMWPE as described for the invention, and as well an improved stress at break from the value to be expected from a linear contribution from the respective components.
Examples 22 and 23 - Mechanical data evaluated for a blend of a commercial low density polyethylene with the HMWPE of Examples 13 to 20 are exemplified in Table-4. LDPE-180 sold by Exxon Chemical Co., U.S.A., was used. This LDPE is a linear homopolymer of ethylene having weight average molecular weight of about 74,000, density of about 0.92 (g/cm3), and M.I. 2.0 (190C., 2.16 kg). DSC measurement provided a Tm value of about 108C. Blend preparation and testing was as described for Examples 1 to 11. For this series of blends MH/MC was about 27.
W0941~064 . 21 610~9 3 PCT~P94101639 . .
Table-4 Mechanical Properties of Blends of LDPE and UHMWPE
Example Nominal Composition Stress at Elongation (number,(LDPE/HMWPE) Break at Break #) (MPa) (%) 22* 100/0 14.2 641 23 80/20 25.8 815 11* 0/100 52.9 536 ~ comparative examples Table-4 illustrates the significant enhancement of elongation when an LDPE-based composition contains the UHMWPE as described for the invention, and as well the improved stress at break (exceeding by a factor of 80~ the value to be expected from a linear contribution from the respective components).
Although the invention has been described with respect to particular materials, means and embodiments it is to be understood that the invention is not limited to the particulars disclosed and extends to all equivalents within the scope of the appended claims.
weight-average M.W. 2 x 106), exhibited not only phases of the two individual components, but also a third phase having a distinct melting temperature Tm. Thus, for example, a binary blend of these polymers in the ratio of wog4n~x~ 21 610 9 ~ PCT~W4/0l639 90/10 showed three melting endotherms at 10 , 124 and i33C
indicating three different kinds of crystalline lamellae populations. This is contrary to the published literature, see for example J. Polym. Sci., Phys. Ed., 25, 89 (1987) and Polymer, _, 426 (1991). Here it is ciearly men~ioned .hat the basic crystalline structure of either com?onent does not change during mixing, and upon cooling the melt of ;. ,.D~
blend of such polymers, the respec~ive crystalline structure of the components is retaine~. These published works clearly mention that only in ~certain cases, for example in blends of HDPE and LLDPE both having nominal molecular weights in the range of 50-100,000, does co-c-ystallization take place. The presently discoverea novel behavior of the Dlend demonstrated the existence ~f at east three types of c_ystalline phase st-lctures :-. the blends of said materials composition of blends of LD?E and UHMWPE.
The mechanisms by which the elongation of conventional polyethylene increases upon the addition of very long molecular weight polyethylene chains was not readily apparent. However the phenomenon is obtained in cases where the ratio of the molecular we-ight of conventional and high molecular weight polyethylene (''MC/MH''~ is preferably less than 1; more preferably less than 0.1 anc most preferably less than 0.01. In other words, the MC/MH, where MH is the molecular weight of UHMWPE and MC s the conventional polyethylene is such that MH/MC > 1; more preferably MH/MC > 10 and most preferably > 25. Note MH in examples 2-10 below is about 2,000,000 and Mc is 60,000.
~hus MH/MC is about 35.
Typical industrial applications for the blends cf the invention are the field of polyolefin films, especially in .hin guage films where strength and elasticity are important t~ fast processlng. The blends exhibit excellent bubble stability and fast drawdowns during film blowing W094~8~ ~ PCT~4/01639 -operations. All of unoriented and singly, or doubly, oriented packaging films for such end-use as food, health care or consumer articles enclosures can be prepared from the blends of this invention in accordance with conventional knowledge in the field. Additionally the invention blends are suitable for injection molding purposes. Items that are normally injection molded such as mechanical goods, household utensils, toys, etc. which use polyethylenes as such or polyethylene compositions incorporating polypropylene and/or ethylene-propylene copolymers, can be made from the disclosed compositions described in this invention.
ml he following examples are presented to illus~rate the foregoing discussion. All parts, proportions and percentages are by weight unless otherwise indicated.
Although the examples may be directed to certain embodiments of the present invention, they are not to be viewed as limiting the invention in any specific respect.
Examples 1 to 11 - Invention blend compositions of a commercial high density polyethylene (HDPE - 6950 YN, a product of Exxon Chemical Co., U.S.A.) and a commercial high density and ultrahigh molecular weight polyethylene (GUR-412 - Lot CM 331584, Hoechst Aktiengesellschaft, DE) were made. The weight-average molecular weight of the former as determined by GPC (gel permeation chromatography) was 62,000 and its Mw/Mn ratio about 4.6. Its melting temperature determined from DSC @ 10C/min was found to be 137.4C and room temperature density as determined by the standard ASTM D-1505 (equivalent DIN-53479D Iso-R-1183D) procedure was found to be 0.96 (g/cm3). Similarly, the weight-average molecular weight of UHMWPE was about 2,000,000 and its Mw/Mn ratio greater than 5Ø Its melting temperature and density values were 133.5 and 0.93 (g/cm3), respectively. The blend compositions were made by dissolving the appropriate quantities of the material in W094/~0~ 21610 9 3 : PCT~4/01639 _ hot xylene at 130C for at least 2 hours with constant mechanical stirring or occasional hand shaking of the flask. An oxidant (2,6-di-tert-butyl-p-creosol ("DBPC", Fluka A.G., Germany) in the amount 0.1 to 0.2 wt ~ was added in the solution to avoid any potential degradation of the polyethylenes. The nominal compositions of series of blends made under this series of experimén`ts are shown in Table-1 below.
At lower concentration of high molecular weight polyethylene, mechanical stirring was readily feasible.
However, at higher concentrations the solution required that they be mildly shaken as the mechanical stirring became difficult due to the observation that solution began to climb up the rod with agitation. In such cases occasional hand shaking of the flask was done to facilitate the dissolution of polymer. After the two polymers were homogeneously mixed, the solution was poured into an aluminum tray. The solvent was let evaporate under an evacuation hood for number of days, usually for 7-10 days.
After bulk of the solvent was removed, the final drying of the material was carried out in a vacuum oven (- 70C) for about 24-48 hours. Subsequently, the material was compression molded into thin sheets of about 1 mm in thickness @ 170-240C with 50-150 bars of pressure.
Dumbell specimens were cut from these sheets and following standard ASTM-D-638M ~equivalent to DIN-53457 Iso-R-527) tensile testing method, room temperature mechanical properties were evaluated. Reported values are of the average values of 3-5 measurements of equivalent samples.
W094/~ 21 610 9~3 ~ " PCT~4/01639 Table-1 Mechanical Properties of Blends of HDPE and UHMWPE
F.Y-~rle Nominal Composition Stress at Elongation (number, #) (HDPE/UHMWPE) Break at Break (MPa) (%) 1* ` ~100/0 21.5 125 2 99.9/0.1 23.2 398 3 99.8/0.2 22.7 609 4 99.5/0.5 20.7 214 99/1 21.4 245 6 98/2 20.3 419 7 95/5 19.8 909 8 90/10 19.7 477 9 80/20 39.4 939 60/40 44.2 708 11 * 0/100 52.9 536 * comparative examples s It is noted from column 3 and 4 where the tensile strength at break and elongation at break data are shown, that the blend compositions containing ultra-high molecular weight polyethylene have dramatically large elongations as compared to the pure HDPE (1) , and greater elongations than those to be expected from an average of the contributions of the HDPE and the UHMWPE (1,11). Thus, for example, example # 2 which contains only 0.1 % of the UHMWPE, exhibits elongation which is larger by a factor of at least 3 (i.e. more than 300 %) over the pure HDPE, while there is only a minor change in its tensile strength.
Similarly, example # 6 when 2 ~ of the UHMWPE is incorporated, elongation of the HDPE increases by about 700 % with simultaneous increase in the tensile strength of HDPE by nearly 100 %.
Example 12 - For illustrative and comparison purposes, polyethylene blends incorporating long chains were also W094/~064 21 61 0 9 3 PCT~P94101639 made by melt mixing. Generally speaking, the melt mixing and processing of very high molecular weight is not readily feasible at the conventional temperatures and torques available in laboratory scale units such as Brabender extruder. However, compositions containing up`to 5 wt ~ of the UHMWPE were found to be capable of effecti~ mixing and thus melt mixed in a Brabender mixer at 240~-C. These were subsequently extruded in the form of -~strip using a rectangular die of opening of 25 mm in width and 2.5 mm in thickness. A Haake model PL-2000-6 single-screw extruder with four heating zones each set nominally at 220C was used. Dumbbell specimens from the center portion of the extruded strip were cut for tensile measurements. Results obtained from the melt mixed materials compared to those obtained from solution matched satisfactorily and were within the experimental error of typical tensile tests, i.e. within 10 ~.
Examples 13 to 19 - Mechanical data evaluated for of blends of linear low density polyethylene with high molecular weight polyethylene are exemplified in Table-2. An LLDPE
SLP-4-2219 sold by Exxon Chemical Co., U.S.A., was used.
The SLP-4-2219 is a linear copolymer of ethylene and butene. Its weight average molecular weight was about 26,000 and Mw/Mn ~ 2.0, butene content ~ 8.7 wt ~1 and density of about 0.91 (g/cm3). DSC measurement provided a Tm value of about 103.4C. Blend preparation and testing was as described for Examples 1 to 11. For this series of blends MH/MC was about 75.
W094/~0~ 21610 9 3 ; PCT~4/01639 Table-2 Mechanical Properties of Blends of LLDPE and UHMWPE
ExampleNominal Composition Stress at Elongation (number, ~LLDPE/VHMWPE) Break at Break #) (MPa) (%) 13* 100/0 8.4 81 14 99/1 8.1 63 98/2 8.1 83 16 95/5 9.2 157 17 90/10 11.5 656 18 80/20 11.4 685 19 60/40 24.8 849 11* 0/100 52.9 536 * comparative examples It is clear from the data shown in above Table-2, that compositions containing less than about 5 wt.~ high molecular weight species dramatically enhanced the elongational properties of SLP-4-2219. Thus for example it is noted at 10-20 ~ of HMWPE that both the tensile strength (stress at break) and elongation at break increase. The former by about 30 ~ and the latter by more than 800 ~, respectively.
Examples 20 and 21 - Mechanical data evaluated for of blends of another linear low density polyethylene with the HMWPE of Examples 13 to 20 are exemplified in Table-3. An LLDPE Exxact3 3010C sold by Exxon Chemical Co., U.S.A., was used. This LLDPE is a linear copolymer of ethylene and butene having weight average molecular weight of about 78,000 and Mw/Mn ~ 2.0, butene content ~ 14 wt ~ and density of about 0.90 (g/cm3). DSC measurement provided a Tm value of about 91C. Blend preparation and testing was as described for Examples 1 to 11. For this series of blends MH/MC was about 25.
WO94/2WK~ 21610 9 3 PCT~4/01639 Table-3 M~ ni cal Properties of Blends of LLDPE and UHMWPE
F~a~rleNominal Composition Stress at Elongation (number,(LLDPE/HMWPE) Break at Break #) (MPa) ` ~ (%) 20* 100/0 25.1 ~-; 864 21 95/5 27.5 ;~ 946 11 0/100 52.9 536 * comparative examples Table-3 illustrates the significant enhancement of elongation when of another LLDPE-based composition contains the HMWPE as described for the invention, and as well an improved stress at break from the value to be expected from a linear contribution from the respective components.
Examples 22 and 23 - Mechanical data evaluated for a blend of a commercial low density polyethylene with the HMWPE of Examples 13 to 20 are exemplified in Table-4. LDPE-180 sold by Exxon Chemical Co., U.S.A., was used. This LDPE is a linear homopolymer of ethylene having weight average molecular weight of about 74,000, density of about 0.92 (g/cm3), and M.I. 2.0 (190C., 2.16 kg). DSC measurement provided a Tm value of about 108C. Blend preparation and testing was as described for Examples 1 to 11. For this series of blends MH/MC was about 27.
W0941~064 . 21 610~9 3 PCT~P94101639 . .
Table-4 Mechanical Properties of Blends of LDPE and UHMWPE
Example Nominal Composition Stress at Elongation (number,(LDPE/HMWPE) Break at Break #) (MPa) (%) 22* 100/0 14.2 641 23 80/20 25.8 815 11* 0/100 52.9 536 ~ comparative examples Table-4 illustrates the significant enhancement of elongation when an LDPE-based composition contains the UHMWPE as described for the invention, and as well the improved stress at break (exceeding by a factor of 80~ the value to be expected from a linear contribution from the respective components).
Although the invention has been described with respect to particular materials, means and embodiments it is to be understood that the invention is not limited to the particulars disclosed and extends to all equivalents within the scope of the appended claims.
Claims (9)
1. Use in a polyethylene blend composition of at least 0.1 % by weight up to but less than 40 %, based on the total composition weight, of a high weight-average molecular-weight polyethylene having a weight-average mol. wt.
greater than 1.5 x 106, for the purpose of improving composition elasticity, wherein in addition to the high weight-average molecular-weight polyethylene the composition comprises from 99.9 to 60 % by weight, based on the total polymer weight, of conventional polyethylene polymers having a weight-average mol. wt. less than 1 x 105.
greater than 1.5 x 106, for the purpose of improving composition elasticity, wherein in addition to the high weight-average molecular-weight polyethylene the composition comprises from 99.9 to 60 % by weight, based on the total polymer weight, of conventional polyethylene polymers having a weight-average mol. wt. less than 1 x 105.
2. The use according to claim 1 wherein said conventional polyethylene polymers are selected from one or more of ultralow-density ("ULDPE"), very low density ("VLDPE"), low density ("LDPE"), linear low density ("LLDPE"), and high density ("HDPE") polyethylene.
3. The use according to either of claims 1 or 2 wherein said high weight-average molecular-weight polyethylene has a weight-average mol. wt. of at least 2 x 106.
4. The use according to any of the preceding claims wherein the ratio of the molecular weight of high molecular weight and conventional polyethylene (''MH/MC'') is greater than 1.
5. A polyethylene composition comprising a blend of a) more than 90 wt.%, based on total weight of polymer, of one or more of conventional polyethylene polymers, and b) from 0.5 to 10 wt. % of high weight-average molecular-weight polyethylene having a weight-average mol. wt.
greater than 1.5 x 106.
greater than 1.5 x 106.
6. A polyethylene film composition comprising a blend of a) more than 85 wt.%, based on total weight of polymer, of one or more of conventional polyethylene polymers or copolymers, and b) from 0.5 to 15 wt. % high weight-average molecular-weight polyethylene having a weight-average mol. wt. greater than 1.5 x 106.
7. The composition according to either of claim 5 or 6 wherein said conventional polyethylene polymers are selected from one or more of ultralow-density ("ULDPE"), very low density ("VLDPE"), low density ("LDPE"), linear low density ("LLDPE"), and high density ("HDPE") polyethylene.
8. The composition according to any of claims 5 - 7 wherein said b) polyethylene has a weight-average mol. wt. of at least 2 x 106.
9. The composition according to any of claims 5 - 8 wherein the ratio of the molecular weight of high molecular weight and conventional polyethylene ("MH/MC") is greater than 1.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9310559.1 | 1993-05-21 | ||
| GB939310559A GB9310559D0 (en) | 1993-05-21 | 1993-05-21 | Elastic polyethylene compositions |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2161093A1 true CA2161093A1 (en) | 1994-12-08 |
Family
ID=10735929
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2161093 Abandoned CA2161093A1 (en) | 1993-05-21 | 1994-05-16 | Elastic polyethylene compositions |
Country Status (5)
| Country | Link |
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| EP (1) | EP0699218A1 (en) |
| JP (1) | JPH09500919A (en) |
| CA (1) | CA2161093A1 (en) |
| GB (1) | GB9310559D0 (en) |
| WO (1) | WO1994028064A1 (en) |
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|---|---|---|---|---|
| GB8914703D0 (en) * | 1989-06-27 | 1989-08-16 | Dow Europ Sa | Bioriented film |
| US5582923A (en) * | 1991-10-15 | 1996-12-10 | The Dow Chemical Company | Extrusion compositions having high drawdown and substantially reduced neck-in |
| US5562958A (en) * | 1991-10-15 | 1996-10-08 | The Dow Chemical Company | Packaging and wrapping film |
| US5472775A (en) * | 1993-08-17 | 1995-12-05 | The Dow Chemical Company | Elastic materials and articles therefrom |
| EP0759047A1 (en) * | 1994-05-09 | 1997-02-26 | The Dow Chemical Company | Medium modulus film and fabrication method |
| US5858515A (en) * | 1995-12-29 | 1999-01-12 | Kimberly-Clark Worldwide, Inc. | Pattern-unbonded nonwoven web and process for making the same |
| EP0908400A1 (en) * | 1997-10-13 | 1999-04-14 | Rockwool International A/S | Packaged mineral wool products |
| US6680265B1 (en) | 1999-02-22 | 2004-01-20 | Kimberly-Clark Worldwide, Inc. | Laminates of elastomeric and non-elastomeric polyolefin blend materials |
| EP1605000A4 (en) * | 2003-03-10 | 2008-04-02 | Asahi Kasei Chemicals Corp | Ultrahigh-molecular ethylene polymer |
| EA015582B9 (en) * | 2007-05-23 | 2012-01-30 | ДСМ АйПи АССЕТС Б.В. | Colored suture |
| JP6457716B2 (en) | 2011-01-14 | 2019-01-23 | ダブリュー・アール・グレイス・アンド・カンパニー−コネチカット | Process for the preparation of modified metallocene catalysts, catalysts produced and their use |
| JP2011208162A (en) * | 2011-07-26 | 2011-10-20 | Sumitomo Chemical Co Ltd | Polyolefin resin film and composition for manufacturing polyolefin resin film |
| RU2609029C2 (en) | 2011-10-26 | 2017-01-30 | Бореалис Аг | Method |
| PT2828333T (en) * | 2012-03-20 | 2016-08-31 | Dsm Ip Assets Bv | Polyolefin fiber |
| KR101936456B1 (en) | 2012-10-05 | 2019-01-08 | 릴라이언스 인더스트리즈 리미티드 | Polymer composition and a process for preparing the same |
| EP2743305B1 (en) | 2012-12-17 | 2015-07-22 | Borealis AG | Process for the preparation of a high density polyethylene blend |
| EP2799487B1 (en) | 2013-05-01 | 2015-11-04 | Borealis AG | Composition |
| EP2907843B1 (en) | 2014-02-13 | 2017-11-15 | Borealis AG | Blend of bimodal polyethylene with unimodal ultra high molecular weight polyethylene with improved mechanical properties |
| EP3037469B1 (en) * | 2014-12-22 | 2017-10-18 | Borealis AG | Process for producing multimodal polyethylene blends including ultra-high molecular weight components |
| US20190256695A1 (en) | 2016-06-22 | 2019-08-22 | Borealis Ag | Polymer composition and a process for production of the polymer composition |
| EP3293208B1 (en) * | 2016-09-12 | 2021-06-16 | Thai Polyethylene Co., Ltd. | Bimodal polyethylene composition and pipe comprising the same |
| KR102183259B1 (en) | 2016-11-25 | 2020-11-30 | 보레알리스 아게 | Novel composition and method |
| EP3418330B2 (en) | 2017-06-21 | 2023-07-19 | Borealis AG | Polymer composition and a process for production of the polymer composition |
| JPWO2022158487A1 (en) * | 2021-01-21 | 2022-07-28 |
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| JPH0692509B2 (en) * | 1985-12-17 | 1994-11-16 | 日本石油株式会社 | Method for producing polyethylene solution for producing high-strength / high-modulus fiber or film |
| JPS63154753A (en) * | 1986-12-18 | 1988-06-28 | Nippon Oil Co Ltd | Polyethylene composition |
-
1993
- 1993-05-21 GB GB939310559A patent/GB9310559D0/en active Pending
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1994
- 1994-05-16 JP JP7500195A patent/JPH09500919A/en active Pending
- 1994-05-16 WO PCT/EP1994/001639 patent/WO1994028064A1/en not_active Application Discontinuation
- 1994-05-16 EP EP94918348A patent/EP0699218A1/en not_active Withdrawn
- 1994-05-16 CA CA 2161093 patent/CA2161093A1/en not_active Abandoned
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| Publication number | Publication date |
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| WO1994028064A1 (en) | 1994-12-08 |
| EP0699218A1 (en) | 1996-03-06 |
| GB9310559D0 (en) | 1993-07-07 |
| JPH09500919A (en) | 1997-01-28 |
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