Fina Technology, Inc.

Exxon Chemical Patents, Inc.

Total Research & Technology Feluy

Total Petrochemicals Research Feluy

William Rusty Wheat

Aiko Hanyu

John Bieser

Guillaume Pavy

Michel Daumerie

Alain Standaert

Hugues Haubruge

Philippe VanDeurzen

Lisa K Albe

Milind B Ajinkya

Stuart B Smith

Hughes Haubruge

William R Storey

Alain Sandaert

The present invention relates to fibers, particularly to as-spun fibers, having improved properties, in particular improved bonding performance and mechanical properties. In particular, the present invention relates to fibers comprising a metallocene random copolymer of propylene and one or more comonomers, said metallocene random copolymer having a broader molecular weight distribution. The present invention further relates to nonwovens comprising such fibers and to a process for producing such fibers and nonwovens. The fibers and the nonwovens of the present invention are characterized by improved properties, in particular improved bonding performance and mechanical properties, when compared to the prior art fibers and nonwovens.

Fibers and Nonwovens with improved mechanical and bonding properties

Bicomponent fibers, methods of forming bicomponent fibers and articles formed from bicomponent fibers are described herein. The bicomponent fibers generally include a sheath component and a core component, wherein the sheath component consists essentially of a first metallocene polypropylene and the core component consists essentially of a second metallocene polypropylene.

Process of making bicomponent fiber

This invention relates to the use of a cyclic ketone peroxide of half-life time larger than one second at a temperature of 225&#xb0; C., for producing a controlled rheology polypropylene heterophasic copolymer of melt index MI2 larger than 15 g/10 min, having simultaneously a very high impact resistance and a high flexural modulus.

Controlled rheology polypropylene heterophasic copolymers

The present invention relates to the improvement of metal bond strength in polypropylene films surface treated at higher levels through the addition to the basic isotactic polypropylene (iPP) polymer of an amount of syndiotactic polypropylene (sPP) in an amount no more than about 10 percent by weight and preferably in an amount between about 0.5 percent and about 8 percent by weight. The invention encompasses both the resulting metallized polypropylene films with enhanced bond strength and the process for producing such films. The prescribed use provides improved bonding properties over a simple non-blended isotactic polypropylene homopolymer, while maintaining at acceptable levels the optical and physical characteristics of a film made from non-blended iPP homopolymer. At increasing percentages of sPP above the preferred levels, bond strength continues to increase, but a deterioration in other properties may be noted, particularly in the optical property haze.

Metal bond strength in polypropylene films

The present invention is for the improvement of inter-layer bonding strength in polypropylene films through the addition of ethylene as a mini-random copolymer in an amount of no more than about 1 weight percent, more preferably no more than about 0.7 weight percent, and most preferably between about 0.3 weight percent to about 0.5 weight percent or even amounts less than about 0.2 weight percent. The invention allows the improvement of inter-layer bond strength in multi-layer films resulting specifically in improved heat seal strength. The invention encompasses both the resulting films with enhanced heat seal strength and the process for producing such films. In the preferred embodiment, the proposed mini-random copolymer is formed into a film layer used in place of a propylene homopolymer layer, providing improved bonding properties over a film formed of polypropylene homopolymer, while maintaining at acceptable levels the physical and optical characteristics of a film layer made from a propylene homopolymer, such as stiffness.

Heat-seal strength in polyolefin films

A process for the production of biaxially-oriented polypropylene film involving the provision of a polypropylene polymer produced by the polymerization of propylene in the presence of a metallocene catalyst characterized by a bridged racemic bis(indenyl) ligand substituted at the proximal position. The polypropylene contains 0.5 to 2% 2,1 insertions and has an isotacticity of at least 96% meso pentads and at least 99% meso diads. The film is formed by stressing the polymer produced from a slot die in the machine direction at a stretch ratio of about 5 or 6 and in the transverse direction at a stretch ratio of about 8 or 9 to produce a biaxially-oriented film having a non-uniform melt temperature of a peak value of less than 160&deg; C. The polypropylene polymer has meltflow index of less than 5 grams per 10 minutes and has an average molecular weight within the range of 100,000-400,000 grams per mole. The film, when configured having a thickness of 18 microns, is characterized by a machine direction secant modulus of at least 1400 MPa, a transverse direction secant modulus of at least 2200 MPa, a kinetic film-to-film co-efficient of friction of no more than 0.5, and permeabilities to water and oxygen of no more than 2.6 g/m /d and 2400 c /m /d, respectively. The film is further characterized by shrinkage factors of at least 8% in a transverse dimension and at least 16% in a transverse direction when heated to a temperature of at least 140&deg; C.

Biaxially-oriented metallocene-based polypropylene films

The present invention relates to the improvement of metal bonding strength in polypropylene films through the addition of ethylene in a mini-random ethylene-propylene copolymer in an amount of no more than about 1 weight percent, more preferably no more than about 0.7 weight percent, and most preferably between about 0.3 weight percent and about 0.5 weight percent, or even amounts between about 0.05 weight percent and about 0.2 weight percent. The invention allows the improvement of metal bond strength in metallizable films. The invention encompasses both the resulting films with enhanced metal bond strength and the process for producing such films. In the preferred embodiment, the proposed mini-random copolymer is formed into a film layer used in place of a propylene homopolymer layer, providing improved bonding properties over a simple polypropylene homopolymer, while maintaining at acceptable levels the physical and optical characteristics of a film layer made from a propylene homopolymer, such as stiffness.

Metal bond strength in polyolefin films

The present invention relates to improved processability of polyolefin films through the addition to the basic isotactic polypropylene (iPP) polymer of a syndiotactic polypropylene (sPP) in an amount within the range of about 2 to 10 weight percent and of a resin or rosin modifier in an amount within the range of 1 to 30 weight percent. Preferably, the composition could contain syndiotactic propylene in an amount within the range of about 2 to 5 weight percent. Preferably, about 3 weight percent of syndiotactic propylene is present in the polyolefin composition. The resin or rosin modifier could, preferably, be present in an amount within the range of 5 to 10 weight percent. Preferably, the composition should contain about 10 weight percent of the modifier. The present invention encompasses both the resulting polyolefin films and the process for producing such films. The improved processability of the film includes fewer webs breaks and drawability at higher line speeds, resulting in fewer shut downs of the processing line and a decrease in manufacturing time. These improvements are measured in terms of variable machine direction orientation draw ratios and transverse direction orientation oven temperatures.

Compositions for improved orientation processing

A process for the production of biaxially-oriented polypropylene film involving the provision of a polypropylene polymer produced by the polymerization of propylene in the presence of a metallocene catalyst characterized by a bridged racemic bis(indenyl) ligand substituted at the proximal position. The polypropylene contains 0.5 to 2% 2,1 insertions and has an isotacticity of at least 96% meso pentads and at least 99% meso diads. The film is formed by stressing the polymer produced from a slot die in the machine direction at a stretch ratio of about 5 or 6 and in the transverse direction at a stretch ratio of about 8 or 9 to produce a biaxially-oriented film having a non-uniform melt temperature of a peak value of less than 160.degree. C. The polypropylene polymer has meltflow index of less than 5 grams per 10 minutes and has an average molecular weight within the range of 100,000-400,000 grams per mole. The film, when configured having a thickness of 18 microns, is characterized by a machine direction secant modulus of at least 1400 MPa, a transverse direction secant modulus of at least 2200 MPa, a kinetic film-to-film co-efficient of friction of no more than 0.5, and permeabilities to water and oxygen of no more than 2.6 g/m.sup.2 /d and 2400 c.sup.3/ m.sup.2 /d, respectively. The film is further characterized by shrinkage factors of at least 8% in a transverse dimension and at least 16% in a transverse direction when heated to a temperature of at least 140.degree. C.

The fouling of the solid cocatalyst inlet nozzle in alpha-olefin Ziegler type polymerizations in stirred liquid phase, mass reaction is eliminated by positioning the inlet nozzle below the liquid surface on substantially the same horizontal plane as the bottom impeller and aligned with the impeller. The inlet nozzle extends from 30 to 80% of the distance between the wall of the reactor and the tip of the impeller. The ratio of the inlet velocity of the solid cocatalyst slurry to the reactor mass cross flow velocity is 2-3:1.

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Houston, TX, United States of America

William Rusty Wheat