Fina Technology, Inc.

Fina Research, S.a.

Mohan R Gownder

Jay Nguyen

Michael Musgrave

Eduardo E Zamora

B Raghava Reddy

Scott Cooper

Lisa Albe

David Young

George R Rowland, Jr

Pamela Lawyer

Jay Nguygen

Bicomponent fibers of syndiotactic polypropylene and ethylene-propylene random copolymer, can be prepared. The bicomponent fibers may exhibit self-crimp properties and high shrinkage characteristics.

Bicomponent fibers of syndiotactic polypropylene

A process for the production of partially oriented polypropylene fibers from syndiotactic polypropylene. Syndiotactic polypropylene is heated to a molten state and extruded to form a fiber preform. The fiber preform is spun at a forward spinning speed within the range of about 700&#x2013;3500 meters per minute to produce a partially oriented fiber. The partially oriented fiber is wound without further substantial orientation of the fiber at a draw ratio of less than 1.5. By operating at a forward spinning speed of about 700 meters per minute or more, the partially oriented fiber has a greater tenacity than would be observed for a fiber formed from a corresponding spun isotactic polypropylene. The fiber preform is spun at a forward spinning speed of at least 100 meters per minute to provide a tenacity on the order of about 2 grams per denier or more. The fiber preform may be spun at a forward spinning speed of at least 1500 meters per minute to provide a tenacity of about 3 grams per denier.

Syndiotactic polypropylene fibers

A method for the production of polypropylene fibers from a propylene polymer including isotactic polypropylene produced by the polymerization of propylene in the presence of an isospecific metallocene catalyst. The polymer is heated to a molten state and extruded to form a fiber preform at a temperature within the range of about 170&#xb0;-210&#xb0; C. The fiber preform is spun at a spinning speed of at least 200 meters per minute and quenched at a heat transfer rate of no more than 12 joules per second fiber. The spun fiber is then subjected to a winding operation. The fiber may be drawn subsequent to the quenching operation and prior to winding. The cooled fiber preform may be drawn to produce a fiber at a draw ratio within the range of about 1.5-4.0 with shrinkage of the fiber over the range of the draw ratio at a variance of &#xb1;25% of the median of the shrinkage factor over the draw ratio.

Process of making polypropylene fibers

Bicomponent fibers of isotactic polypropylene and syndiotactic polypropylene, methods of making such fibers and products made thereof are disclosed. Embodiments of the bicomponent fibers can exhibit self-crimp properties and high shrinkage characteristics.

Bicomponent fibers of isotactic and syndiotactic polypropylene

The present invention relates to a process for making polymer tapes utilizing metallocene catalysts. An isotactic propylene polymer is prepared by polymerizing propylene in the presence of an isospecific metallocene catalyst. The resulting polypropylene is heated, extruded and withdrawn as a sheet. The sheet is then slit longitudinally into tape segments and drawn in the longitudinal direction to a draw ratio of at least about 4.5:1 to produce an oriented tape. It has been found that these polypropylene tapes have different characteristics than those polypropylene tapes produced using Ziegler-Natta catalyst drawn at the same draw ratios.

Method of producing polypropylene tapes

The present invention relates to a method for the production of polypropylene fibers resulting in improved shrinkage percentages and to polypropylene fibers themselves having improved shrinkage percentages. The method includes providing a polypropylene polymer with a melt flow index of no more than about 25 grams per 10 minutes. This polymer should include isotactic polypropylene produced by the polymerization of propylene in the presence of an isospecific metallocene catalyst. The polymer is then heated to a molten state and extruded to form a fiber preform. The preform is spun and subsequently drawn at a take-away speed and a drawing speed providing a draw ratio of no more than about 3, and more preferably no more than about 2.5, to produce a continuous polypropylene fiber. The fiber based on metallocene catalyzed isotactic polypropylene demonstrates improved shrinkage properties of at least about 10% and at some draw ratios at least about 25% over the shrinkage properties of Ziegler-Natta catalyzed isotactic polypropylenes having similar melt-flow indices. In the same method, when the polymer is heated to a molten state, the polymer is preferably heated in a feeding zone to a temperature within the range of about 180&deg; C. to about 225&deg; C. followed by heating in an extrusion zone to a temperature within the range of about 215&deg; C. to about 240&deg; C. immediately prior to extruding the polymer.

Reduced shrinkage in metallocene isotactic polypropylene fibers

Bicomponent fibers of isotactic polypropylene and syndiotactic polypropylene, methods of making such fibers and products made thereof.

Bicomponent fibers of isotactic and syndiotactic polypropylene, methods of making, products made thereof

A polymer blend, fibers manufactured from the blend and method of producing the fibers is disclosed. The polymer blend includes from 92 wt % to 98.5 wt % of a base polypropylene having a melt flow rate of less than 20 g/10 min, and a maximum draw ratio D, a Crimp Stability of CS, when drawn into filaments at 1000 m/sec, and from 8 wt % to 1.5 wt % of an amorphous polystyrene having a melt flow rate of less than 15 g/10 min. The polymer blend is drawable at greater than 800 m/sec to produce filaments having a maximum draw ratio of D,, the ratio of D,: D,, being greater than 1.15:1 and a Crimp Stability of CS,, the ratio of CS,: CS,being greater than 1.45. Preferably, the base polypropylene has a melt flow rate of between 8 and 15 g/10 min. In one embodiment, the amorphous polystyrene is characterized by a melt flow between 2 and 15 g/10 min., a tensile strength of between 6000 and 9000 psi, a modulus of between 250,000 and 500,000 psi, a flexural strength of between 8000 and 16,000 psi, a flexural modulus of between 300,000 and 500,000 psi, a Vicat softening point of between 180&deg; F. and 240&deg; F., and an annealed heat distortion of between 170&deg; F and 220&deg; F.

Polypropylene/polystyrene polymer blend, improved fibers produced from the blend and method of manufacturing

Process for the production of polypropylene fibers from polypropylene polymers produced by the polymerization of polypropylene 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 95% meso diads and is heated to a molten state and extruded to form a fiber preform. The preform is subjected to spinning at a spinning speed of at least 500 meters per minutes and subsequent drawing at a speed of at least 1,500 meters per minute to provide a draw ratio of at least 3 to produce a continuous polypropylene fiber. The draw speed and/or the draw ratio can be varied to produce fibers of different mechanical properties. Different polypropylene polymers produced by different metallocene catalysts can be used. Such fibers can be characterized by having an elongation at break of at least 100% and a specific toughness of at least 0.5 grams per denier.

Polypropylene fibers

A process for the production and treatment of a stereoregular polypropylene, such as isotactic polypropylene in which a polymerization reactor is operated under conditions to react propylene supplied to the reactor to produce a stereoregular propylene polymer fluff. A product stream containing the fluff and unreacted propylene is withdrawn from the reactor and at least a portion of the unreacted propylene is separated from the product stream. The propylene polymer fluff is heated to a temperature sufficient to melt the propylene polymer, and a lactone is incorporated into the propylene polymer. The lactone is a 5,7 dialkyl-3-(2,3 dialkyl phenyl)-3H-benzofuran-2-one, in which the 5,7 and 2,3 substituents are of relatively low molecular weights. The phenyl alkyl substituents, each contain 1 or 2 carbon atoms, and the 5,7 alkyl substituents each contain from 2 to 5 carbon atoms. After the heating and incorporation of the lactone, the heated polymer fluff containing the lactone is extruded to produce particles of the propylene polymer. The polymer particles containing the lactone can be heated to a molten state and then extruded to form a fiber preform. The fiber preform is subject to spinning and drawing at differential spinning and drawing speeds to provide a draw ratio sufficient to form a continuous polypropylene fiber.

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LaPorte, TX, United States of America

Mohan R Gownder