KR20070019661A - High tenacity and toughness in metallocene polypropylene films - Google Patents

Abstract

The present invention provides a film article comprising a metallocene catalyst polypropylene and having a tenority of at least about 2.8 g / den and a method of making the same. The film product may be drawn at a draw ratio of about 5.0: 1-10.0: 1. The film product can also be processed into slit tape. The invention also provides a method of weaving a woven product from slit tape having a tenority within 10.0 percent of the film product tenority.

Film Products, Metallocene Catalysts, Polypropylene, Slit Tape

Description

Metallocene polypropylene film having high tenority and toughness {HIGH TENACITY AND TOUGHNESS IN METALLOCENE POLYPROPYLENE FILMS}

The present invention relates to the field of polymers and more particularly to the field of film products comprising metallocene catalyst polypropylene.

Polypropylene is generally produced in a continuous polymerization reactor, which may include loop reactors. The monomer stream can be introduced into a loop reactor so that the polypropylene can be circulated with the appropriate catalyst. Ziegler-Natta catalysts are conventional catalysts used to produce polypropylene by polymerization. After polymerization the polypropylene can generally be recovered from the reactor in powder or granule form. The granule polymer may then be subjected to appropriate purification and processing steps. After such a step, the polymer may be extruded in a molten state through an extruder and a die mechanism to be converted into a film or other product. Such film products can be used to make end-use products such as slit tapes, woven fabrics, and the like.

For example, conventional methods for making end-use products such as woven fabrics may include exposing the film product to high stress operations such that the end-use product has degraded strength and toughness properties. Accordingly, there is a need for film products that include high strength and toughness properties. There is also a need for a film product that can maintain its strength and toughness properties almost even after exposure to the high stress operations used to convert it to a desired end use product.

       One embodiment of the invention provides a film product comprising a metallocene catalyst polypropylene, having a tenority of at least about 2.8 g / den and capable of drawing at a draw ratio of about 5.0: 1-10.0: 1. . The film product also has a tenority of about 5.0 g / den and can be processed into at least one of slit tape and woven products. This film product and / or slit tape product may be woven into a woven product. The metallocene catalyst polypropylene may be a metallocene catalyst isotactic polypropylene.

       Another embodiment of the present invention provides a method for producing a metallocene catalyst polypropylene by polymerizing monomers in the presence of a metallocene catalyst system comprising a metallocene catalyst; Processing metallocene catalyst polypropylene into a film product; Provided is a method of drawing a film product at a draw ratio of about 5.0: 1-10.0: 1 to produce a film product having a tenority of at least about 2.5 g / den. The monomer may be made of propylene and the metallocene catalyst system may comprise a promoter such as an organoaluminum compound. The metallocene catalyst system may comprise at least one of a homogeneous catalyst system and a supported catalyst system. The polymerization of the monomers can be carried out in a loop reactor system. The method may further comprise extruding the metallocene catalyst polypropylene and drawing the metallocene catalyst polypropylene through the die. The method may also include processing the film product into a slit tape product, such as slitting the film product, and / or weaving the slit tape product into a fabric, and weaving the film product into a fabric. The film product may be a metallocene catalyst isotactic polypropylene having up to about 99.0 percent isotacticity.

       Another embodiment of the invention extrudes a metallocene catalyzed polypropylene, molds the metallocene catalyzed polypropylene into an almost flat product, cools an almost flat product, and converts the nearly flat product into a metallocene catalyst polypropylene film. Provided is a method of making a metallocene catalyzed polypropylene film article having a tenority of at least about 2.5 g / den, comprising stretching into an article. Molding can use a die to mold an almost flat product. The cooling may comprise (i) at least one chill roller; (ii) cooling the nearly flat product with a chiller selected from the group consisting of at least one quench bath. At least one cooling roller can cool the nearly flat product to a temperature of about 30-60 ° C. Elongation heats (i) an almost flat product; (ii) draws almost flat products; (iii) annealing the almost flat product. The heating may further comprise heating the nearly flat product to a temperature of about 130-180 ° C. The drawing further includes drawing the nearly flat product at a drawing ratio of about 5.0: 1-10.0: 1. Annealing may further comprise heating the substantially flat product to a temperature of about 130-170 ° C. The method may further comprise processing the film product into a slit tape product, weaving the slit tape product into a woven product, and weaving the film product into a woven product.

Another embodiment of the present invention provides a slit tape to a loom which is intended to be stored in a loom beam; From slit tape comprising a treated metallocene catalyzed polypropylene film product having a tenority of 2.5 g / den, comprising weaving the slit tape into a woven product having a tenority within 10.0 percent of the slit tape tenority. Provides a method of weaving woven products. This method may include weaving a plurality of fill yarns into a woven product. The woven product can have a tenority within 10.0 percent of the metallocene catalyst polypropylene film product tenority.

The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Further features and advantages of the invention are described below to make the subject matter of the invention claimed. It will be understood by those skilled in the art that the described concepts and specific embodiments can be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. Moreover, those skilled in the art will appreciate that such equivalent constructions do not depart from the spirit and scope of the present invention as set forth in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS In order to explain in detail the preferred embodiments of the invention, the accompanying drawings are presented by reference:

1 shows a process for producing a polypropylene resin and a film product.

2 shows a process for producing a film product and a slit tape.

3 shows a process for producing a film product and a slit tape.

4 shows a process for producing a woven product.

I. Polypropylene Polymerization and Film Products

1 shows a process for producing a polypropylene resin and a film product. Polypropylene resins are prepared by polymerizing in reactor system 5 using a metallocene catalyst. The polypropylene resin is then processed in the film processing unit 10 to produce a film product. Film products made from polypropylene of this reactor system 5 have high strength and high toughness properties. For example, the film product may exhibit a tenority of about 5.0 g / den when slit as in the process described in FIG. 3 (ASTM D-3218). Also, the tenority may be at least about 2.5 g / den. The film product may be drawn at a draw ratio of about 9.25: 1. Optionally, the film product may exhibit a draw ratio of about 5.0: 1-10.0: 1. The film product can be drawn at a drawing speed of 250-1000 feet per minute. In addition, when slit according to FIG. 3, the film product may exhibit a measured elongation of about 10-50% (ASTM D-882). In addition, the film product may include a measured secant modulus of about 10-50 g / den (ASTM D-882). In this discussion, a typical slit film may consist of about 500-2000 g denier per 9000 meters. This film product can almost maintain its strength and toughness even after the end-use processing such as the following weaving process. For example, a typical woven product made from a film product may contain a tenority of about 4.8 g / den. Optionally, a typical woven product may include tenority within about 10.0 percent of the film product tenority. Optionally, typical weaving products may contain tenority within about 4.0 percent of the film product tenority.

As can be seen in FIG. 1, the reactor system 5 comprises a prepolymerization system 22 having a loop reactor 15, a propylene feed line 20 and a catalyst system input line 25. The loop reactor 15 may have an impeller 30. The impeller 30 is rotatable and may be arranged such that the polymerization materials are continuously circulated through the loop reactor 15. The loop reactor 15 may be adapted to operate under controlled temperature and pressure conditions. The propylene feed line 20 may be connected to the loop reactor 15. In addition, the propylene feed line 20 may be arranged to supply propylene to the loop reactor 15. The catalyst system input line 25 may be connected to the loop reactor 15. The catalyst system input line 25 may be adapted to feed the metallocene catalyst system to the loop reactor 15.

The following describes an exemplary application of the reactor system 5 shown in FIG. 1. Catalyst system input line 25 feeds the metallocene catalyst system to loop reactor 15. In the prepolymerization system 22, the carrier solvent supply line 40 may supply the carrier solvent to the catalyst mixing line 35. Carrier solvents are well known in the art and examples of suitable carrier solvents may include hexane, heptane, propane, propene and the like. The crude catalyst supply line 45 may supply the crude catalyst to the catalyst mixing line 35. The electron donor line 50 may supply electron donors to the catalyst mixing line 35. Electron donors are well known in the art and include amines, amides, ethers, ketones, nitriles, phosphines, stybines, arsines, phosphoramides, thioethers, aldehydes, alcoholates, organic acids. Salts and the like. The metallocene catalyst input line 55 may supply a metallocene catalyst to the catalyst mixing line 35 to form a metallocene catalyst system. The metallocene catalyst may include a supported catalyst. Optionally, the metallocene catalyst may comprise at least one of a homogeneous catalyst and a mixture of a supported catalyst and a homogeneous catalyst. The mixer 60 may mix the metallocene catalyst system. Examples of available mixers are well known and may include any mixer suitable for mixing the catalyst system on line. Prepolymerization line 65 may expose the metallocene catalyst system to propylene. Propylene can be prepolymerized in loop reactor 62 with a short residence time. The metallocene catalyst system can then be introduced into catalyst system input line 25 as described in more detail below. Catalyst system input line 25 may introduce a metallocene catalyst system into loop reactor 15. The metallocene catalyst system and the propylene mixture may comprise a polymerization reactant. The impeller 30 may circulate the polymerization reactant. The polypropylene product may comprise a metallocene catalyst isotactic polypropylene (“m-iPP”). The m-iPP product of the loop reactor 5 exits the loop reactor 5 to the film processing unit 10. Introduced, whereby m-iPP can be processed into a film product. Optionally, the m-iPP product exiting the loop reactor can be sold to a filmmaker who, in combination with any additives, extrudes into granules or pellets and then supplies the granules to a film processing unit.

In another embodiment, m-iPP may be treated with an additive. Additives may be added to the reactor system 5 during the polymerization. Optionally, additives may be added to m-iPP after polymerization. The additive may comprise up to 4.0 weight percent m-iPP. Suitable additives include, but are not limited to, antioxidant process stabilizers, light stabilizers, antacids, lubricants, processing aids, anti-blocking additives, slip additives, antifogging additives, antistatic additives, fireproofing agents, nucleating agents , Fillers, pigments and antimicrobials.

II. Metallocene  Catalyst Loading and Support

Useful catalyst systems for the formation of isotactic polyolefins include racemic bis-indenyl compounds of the type described in US Pat. No. 4,794,096 to Ewen. Bis (indenyl) ligand structures may be unsubstituted or substituted as described below. Examples of bis (indenyl) type catalysts that can be used are: rac-dimethylsilyldiylbis (2-methyl-4-phenyl-1-indenyl) zirconium dichloride and rac-dimethylsilyldiylbis (2-methyl -1-indenyl) zirconium dichloride.

Other isospecific metallocenes useful in the practice of the present invention may be based on cyclopentadienyl fluorenyl ligand forms substituted without symmetry. Catalysts of this nature are described in US Pat. No. 5,416,228 to Ywen et al. The ligand structure is such that one cyclopentadienyl group of the crosslinked ligand has a bulky group on one of the terminal positions of the cyclopentadienyl ring. Typical of such metallocene catalysts is isopropylidene (3-tert-butyl butyl cyclopentadienyl fluorenyl) zirconium dichloride.

Other isospecific metallocenes that can be used in the present invention are based on cyclopentadienyl fluorenyl ligand structures as described in US Pat. No. 6,559,089 to Razavi et al. This ligand structure is characterized by bridged cyclopentadienyl and fluorenyl groups in which cyclopentadienyl groups are substituted in both adjacent and terminal positions. Terminal substituents are preferably bulky groups such as tertiary butyl groups and adjacent substituents are preferably less bulky groups such as methyl groups which may or may not be close to the terminal substituents. The fluorenyl group may be unsubstituted or substituted with eight substituents but is preferably unsubstituted at a position terminal to the bridgehead carbon atom. Specifically described in US Pat. No. 6,559,089 isopropylidene (3-tertiary butyl, 5-methyl cyclopentadienyl fluorenyl) zirconium dichloride and isopropylidene (3-tertiary butyl, 2-methyl cyclopenta Dienyl fluorenyl) zirconium dichloride.

Another isospecific metallocene based on bis (fluorenyl) ligand structure is described in US Pat. No. 5,945,365 to Reddy. Wherein the ligand structure is characterized by two crosslinked fluororenyl groups having one or two substituents at terminal positions on each fluorenyl group, wherein one group of substituents is transverse from the other with respect to the bilaterally symmetrical plane extending through the crosslinking group Is located. Preferred ligand structures are crosslinked bisfluorenyl ligands substituted at the 4, 4 'position by methyl, methoxy, isopropyl or tertiary butyl groups. For further description of isospecific metallocenes, see US Pat. Nos. 4,794,096, 5,416,228, 5,945,365, and 6,559,089, incorporated herein by reference.

Catalysts for producing isotactic polyolefins are described in US Pat. Nos. 4,794,096 and 4,975,403 to Yiwen. These patents describe stereorigid metallocenes that are particularly useful for polymerizing olefins to form isotactic polymers and for polymerizing high isotactic polypropylene. For example, stereorigidity in metallocene ligands is imparted by structural bridges extending between cyclopentadienyl groups as described in US Pat. No. 4,794,096, supra. Specifically described in this patent are stereoregular hafnium metallocenes which can be characterized by the following formula:

R "(C ₅ (R ') ₄ ) ₂ HfQ _p (5)

In formula (5), (C ₅ (R ′) ₄ ) is a cyclopentadienyl or substituted cyclopentadienyl group, R 'is independently hydrogen or a hydrocarbyl radical having 1-20 carbon atoms, R Is a structural bridge extending between cyclopentadienyl rings. Q is a hydrocarbon radical such as alkyl, aryl, alkenyl, alkylaryl or arylalkyl, having halogen or 1-20 carbon atoms, and p is 2 to be.

III. M- IPP

The metallocene propylene product of the loop reactor 5 may comprise stereoregularity (m-iPP) which is generally isotactic. Optionally, the polypropylene product may comprise stereoregularity (m-sPP) which is generally syndiotactic. The isotacticity of a polypropylene product can be measured as a percentage of the content of the meso form in the amount of the polypropylene product. For example, the isotacticity of m-iPP may have an isotacticity of about 99.0 weight percent or less of m-iPP. Optionally, m-iPP may have isotacticity of about 95.0 weight percent or less of m-iPP. Still other may include m-iPP having an isotacticity of about 90.0 weight percent or less of m-iPP. m-iPP may also include regioregularity with 1,2 insertions and 2,1 insertions, which may be indicated as insertion errors. Insertion errors can be measured as the percentage of occurrences of 2,1 insertions associated with 1,2 insertions. For example, m-iPP may have an insertion error of m-iPP up to about 5.0 weight percent. Optionally, m-iPP may have an m-iPP insertion error of about 2.0 weight percent or less. Still others include m-iPPs having an insertion error of about 0.5 weight percent or less of m-iPPs. Other properties of m-iPP include a melting temperature of about 125-165 ° C. In addition, m-iPP may have a melt flow rate (“MFR”) of about 2.0-100 dg / min as measured by ASTM D1238 “L”. Another property includes m-iPP with a molecular weight distribution (“MWD”) of about 2.0-7.0.

VII. Film products and Slit  Manufacture of tape

Processing polypropylene into film products that can be slit into tape is well known in the art. In the embodiment shown in FIG. 2 a line of "Bouligny Slit Tape" is used to make the slit tape. The film processing unit 10 may include a hopper 70, an extruder 75, a slot die 80, a quench jaw 160, one or more slitter blades 165, and side stretches 90.

The following describes an exemplary application of the embodiment shown in FIG. 2. The polypropylene is fed to the hopper 70 and stored there. Polypropylene is directed from the hopper 70 to the extruder 75 where sufficient heat can be applied to melt the polypropylene. Extruder 75 may comprise a temperature profile of about 196 ° C / 207 ° C / 218 ° C / 229 ° C / 242 ° C / 252 ° C. Optionally, the extruder 75 may be operated at a temperature profile that is higher or lower than that temperature profile as conditions such as the amount of polypropylene, the composition of the polypropylene, desired product properties, and the like change. The polypropylene may be directed from the extruder 75 to the slot die 80 where the polypropylene may be made into a flat film. The flat film may be directed to a quench bath where the flat film is at a temperature of about 37 ° C. Can be cooled. The film sharing unit 10 may include at least one slitter blade 165 capable of slitting a film product to manufacture a slit tape. At least one slitter blade 165, and preferably multiple slitter blades, may be disposed behind the quench bath 160 in the film processing unit 10. However, at least one slitter blade may be arranged in any other position suitable for producing the slit tape in the film processing unit 10. Roller 168 may have cooled slit tape from at least one slit blade 165 or quench bath 160 at a speed of about 100 feet per minute. The plurality of rollers 170 may direct the cooled slit tape to the lateral stretch 90 at a speed of about 100 feet per minute. The plurality of rollers 70 can exert a stretching force on the cooled slit tape.

In the lateral stretch 90 of FIG. 2, the preheating zone 135 may heat the slit tape in an oven at about 190 ° C. FIG. Slit tape from the preheat zone 135 may be directed to the draw zone 140. Slit tape can be drawn at a draw ratio of about 9.25: 1. Optionally, the slit tape may be drawn at a draw ratio of about 8.0: 1-10.0: 1. As another option, the slit tape may be drawn at a draw ratio of about 5.0: 1-12.0: 1. The slit tape is directed to the annealing portion 45 where the slit tape can be heated to a temperature of about 165 ° C. Optionally, the slit tape may be heated to a temperature of about 130-170 ° C. The slit tape is withdrawn from the side drawer 90 to the slit tape product and directed by a plurality of rollers to a plurality of collection spools (not shown) for storage. The collection spool may be arranged to store the slit tape product. It may include any suitable device. Slit tape may include properties that are nearly similar to film products. For example, the slit tape may comprise a tenority of about 5.0 g / den. Optionally, the tenority may be at least about 2.5 g / den.

In another embodiment shown in FIG. 3, the biaxially oriented film processing unit 10 is used to make a film that is slit with tape. Film processing unit 10, for example, a "Tenter Frame" orientation process, can produce biaxially oriented polypropylene products. The film processing unit 10 may include an extruder 75, a slot die 80, a transverse stretching unit 85, and a side stretching unit 90.

The following describes an exemplary application of the embodiment shown in FIG. 3. After leaving the reactor, the polymer is generally purified, dried, additive activated and pelletized. It may also be pellet blended with colorants, processing aids, fillers, and the like, which are common in the art. The polypropylene may then be fed from the hopper 70 to the extruder 75. The extruder 75 may also include any extruder sufficient to extrude the polypropylene within the operating conditions of the tenter frame process. Extruder 75 may comprise a temperature profile sufficient to provide a polymer melt temperature of about 200-260 ° C. Optionally, the extruder 75 may be operated at a temperature profile that is higher or lower than that temperature profile as conditions such as the amount of polypropylene, the composition of the polypropylene, and the like change. The molten polypropylene is then directed to the slot die 80 where the polypropylene can be turned into a flat film 95. Flat film 95 is applied to cooling roller 100 whereby flat film 95 may be cooled to a temperature of about 30-60 ° C. The cooled flat film 95 is introduced from the cooling roller 100 into the stretching portion 85 where the at least one idle roller 105 cools the flat film 95 to the at least one preheating roller 110. Can be oriented. The idle roller and at least one preheat roller 110 may stretch the cooled flat film 95. The at least one preheat roller 110 applies heat to the flat film 95 to increase the temperature of the flat film 95 to about 60-100 ° C. The heated flat film 95 is directed from the at least one preheat roller 110 to the slow roller. The slow roller 115 may be operated at a speed of about 10-40 feet per minute. The flat film 95 is directed from the slow roller 115 to the fast roller 120, which is about 150 feet per minute so that its surface velocity at its circumference is about 5-10 times that of the slow roller 115. Can be operated at speed. The slow roller 115 and the fast roller 120 may further stretch the flat film 95. Thereafter, the flat film 95 may be introduced into the orientation roller 125 at room temperature. At least one idle roller 130 from the orientation roller 125 directs the flat film 95 to the lateral stretch 90.

In the lateral stretch 90 of FIG. 3, the flat film 95 can be oriented by applying a force to stretch the flat film 95 in a substantially transverse direction. Side draw 90 may include at least one tandem heating roller (not shown), preheat 135, draw 140, and annealing 145. At least one tandem heating roller may direct flat film 95 to preheat 135 where the flat film 95 may be heated to a temperature of about 130-180 ° C. The flat film 95 is directed from the preheat 135 to the draw 140. The drawer 140 may include at least one attachment device that may be secured to the opposite side of the flat film 95 to provide a lateral force on the opposite side of the flat film 95. The attachment device may comprise a tenter clip or any other suitable attachment device. Flat film 95 may be stretched to a side draw ratio comprising about 8.0: 1-12.0: 1, which is a measure of the original width of flat film 95. Optionally, the lateral draw ratio may be about 5.0: 1-10.0: 1. The flat film 95 is then directed to the annealing portion 145 where the flat film 95 may be heated to a temperature of about 130-170 ° C. Annealing portion 145 may comprise an oven or any other suitable apparatus for heating flat film 95. The flat film 95 may be heated in the annealing portion 145 for a time of about 1-10 seconds. Thereafter, the flat film 95 may be recovered from the side drawing unit 90 to the film product and directed to the cooling roller 150. The cooling roller 150 may be arranged to reduce the temperature of the film product to about 50 degrees Celsius or less. The film product may be directed by a take up spool 150 to a collection spool (not shown) for storage. The film processing unit 10 may further include at least one slitter blade (not shown) capable of slitting the film product to produce the slit tape as described above. The slitter blade may comprise any slitting device suitable for slitting a film product with slit tape. The slitter blade may be disposed after the side drawing portion in the film processing unit 10. However, at least one slitter blade may be disposed at any other position in the film processing unit 10, which may be suitable for making slit tape. The slit tape can be made in any suitable width. While the above has described exemplary applications for producing film products, the present invention is not limited to the above description. For example, the film processing unit 10 may include apparatuses and steps in which the order is not limited to the described apparatuses and steps. In addition, the film processing unit 10 may include any additional device, as is well known in the art, for producing a film product. In addition, the film processing unit 10 can be fully operated in a smaller number than all of the apparatuses described in manufacturing the film product.

VIII. Of the woven fabric (WOOVEN FABRIC)  Produce

4 illustrates a weaving process 175 for making a woven fabric from a slit tape. The weaving process 175 may include at least one loom beam 180. In addition, the weaving process 175 may include at least one loom 185. The loom beam 180 supplies a loom 185 having a number of warp yarns (not shown) and at least one shuttle (not shown). Weaving processes are well known in the art and may include any suitable loom beams and looms from which the woven fabric can be made.

The following describes an exemplary embodiment of the weaving process 175 shown in FIG. As shown in FIG. 4, the slit tape is directed to the loom beam 180, where the slit tape can be stored. The loom beam 180 may be arranged to supply about 100-3000 slit tape warps to the loom 185. Optionally, the loom beam 180 may provide more or less slit tape inclination depending on factors such as the width of the loom beam 180, the width of the slit tape, the desired closeness of the woven product, and the like. Multiple fill yarns may be arranged to travel in a direction that substantially crosses the machine direction. Multiple fill yarns may be disposed outside of loom 185 in a package (not shown). Optionally, multiple peel yarns can be placed inside the loom 185 in the package. The package may include any suitable product or container that may be arranged to store a plurality of fill yarns in the weaving process 175. Multiple fill yarns may be supplied from the package to the loom 185 by a shuttle (not shown). Shuttles are well known in the art and may include any suitable device for feeding fill yarns. The shuttle can be arranged to pass a number of fill yarns almost across loom 185. Multiple peel yarns can then be cut and passed nearly behind the loom 185 so that the shuttle repeats the process again. Multiple fill yarns may then be woven with slit tape to produce the desired woven product. The woven fabric can include monofilament, strapping, netting, and the like.

IX. Example

The following examples are provided to further illustrate various examples of the present invention.

Example 1

In this example, m-iPP and zn-iPP polymers were prepared and their stereoregularity and regioregularity were compared. Table 1 sets forth the stereoregularity and regioregularity of m-iPP for Ziegler-Natta catalytic propylene ("zn-iPP"). In this example, stereoregularity in the isotacticity of m-iPP and zn-iPP and legoregularity in insertion error were measured by nuclear magnetic resonance ("NMR"). Table 1 shows the average result isotacticity and insertion error of such measurements. As shown in Table 1, the m-iPP measurements show about 15 percent lower isotacticity than the zn-iPP measurements. In addition, insertion errors can generally be more than doubled in m-iPP than in zn-iPP measurements. As a result, such high levels of chain deformation can be m-iPP which can produce stronger woven products than woven products made from zn-iPP film products.

TABLE 1

Example 2

In this example, m-iPP and zn-iPP polymers were prepared and slit tapes were made from film products made from these polymers. Propylene monomers were polymerized by methods common in the art for the preparation of m-iPP and zn-iPP polymers. In addition, similar additive packages were added to both m-iPP and zn-iPP prior to pelletization.

Table 2 shows typical MFR and MWD values for the polymers made in this example. As described in Table 2, the m-iPP polymer showed lower average MFR and MWD than the zn-iPP polymer.

TABLE 2

Table 3 shows the average characteristics of each slit tape made of film products made of m-iPP and zn-iPP polymers. The polymers were processed to their limit of drawability at their respective driving conditions, that is, they were treated with an acceptable and similar level of draw brake. The draw ratios used for m-iPP and zn-iPP, respectively, were chosen as the maximum. These average properties were measured by taking 5-10 measurements of each property using the procedure described above.

TABLE 3

The m-iPP and zn-iPP slit tapes had similar denier as described in Table 3. However, m-iPP slit tape showed higher module and lower tape stretch than zn-iPP slit tape. As will be further explained, m-iPP tapes exhibited maximum tenority at higher draw ratios than zn-iPP tapes. As will be explained further, the m-iPP slit tape showed about 16 percent higher tape tenity than the zn-iPP slit tape before weaving. In addition, the m-iPP slit tape showed a tape tenority about 4 percent after weaving (nonwoven and stripped for measurement), and the zn-iPP slit tape showed a tape tenority about 42 percent after weaving. As in the results shown in Tables 2 and 3, m-iPP slit tapes have a higher strength than zn-iPP slit tapes both before and after weaving. In addition, m-iPP slit tape can withstand stress during weaving better than zn-iPP slit tape. Thus, m-iPP woven articles may comprise fewer polymers than woven articles made of zn-iPPfh to produce woven articles with nearly similar toughness and strength properties.

Example 3-14

Examples 3-8 describe m-iPP slit tapes prepared at various draw ratios and Examples 9-14 describe zn-iPP slit tapes prepared at various draw ratios. The m-iPP polymer used to make the m-iPP slit tape showed an MFR of 4.0 g / 10 min. The zn-iPP polymer used to make the zn-iPP slit tape showed an MFR of 3.8 g / 10 min.

Slit tapes were prepared from m-iPP and zn-iPP polymers on a conventional Bouligny Tape Line with an extruder set at a temperature setting of about 200-210-220-230-240-250 ° C. The Bowlini tape line also included a quench tank operated at about 270 ° C. The speed coming from the quench tank was about 100 feet per minute. The film (or tape) was heated in an oven set to about 200 ° C. In the draw, the film product was drawn at a draw ratio of about 5.0: 1-8.0: 1. The drawn film product was annealed in the annealing section and was run at a setting temperature of about 160 ° C. The slit tape described in Examples 3-14 exhibited a denier of about 1000 g / 9000 m. Various properties of the slit tapes produced at various draw ratios were measured and the results are shown in Table 4, where Example 3-8 is m-iPP and Example 9-14 is zn-iPP.

TABLE 4

      As shown in the results of Table 4, the m-iPP tapes showed statistically the same or better tenority at a draw ratio of 6.5: 1 or higher and better elongation at all draw ratios, i.e. Much improved elongation.

       It is to be understood that the present invention is not limited to tender frame and bowie tape line processes, but may include any suitable process for the manufacture of film products and slit tapes. In addition, the present invention is not limited to looms in the manufacture of woven articles but may include any suitable process for the production of woven articles from film products or slit tape. Although the invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made without departing from the spirit and scope of the invention as defined in the appended claims.

Claims (44)

Metallocene catalyst polypropylene; Has a tenority of at least about 2.8 g / den, A film product, which can be drawn at a draw ratio of about 5.0: 1-10.0: 1. The film product of claim 1, further comprising a tenority of about 5.0 g / den. The film product of claim 2, wherein the film product can be processed into slit tape and woven product, the tenority of the woven product being about 4.8 g / den. The film product of claim 1, wherein the draw ratio is about 9.25: 1. The film article of claim 1, wherein the metallocene catalyst polypropylene comprises at least one additive. The film product of claim 1, wherein the film product can be processed into a slit tape product. The film product of claim 6, wherein the at least one film product and the slit tape product can be woven into a woven product. 8. The film product of claim 7, wherein the woven product comprises tenority within about 10.0 percent of the tenority of at least one of the film product and the slit tape product. The film article of claim 1, wherein the metallocene catalyst polypropylene comprises metallocene catalyst isotactic polypropylene. 10. The film article of claim 9, wherein the metallocene catalyst isotactic polypropylene comprises up to about 99.0 percent isotacticity. 10. The film article of claim 9, wherein the metallocene catalyst isotactic polypropylene comprises at least about 2.0 percent insertion error. The film article of claim 1, wherein the metallocene catalyst polypropylene comprises polymerized propylene. (A) polymerizing monomers in the presence of a metallocene catalyst system comprising a metallocene catalyst to produce a metallocene catalyst polypropylene; (B) processing metallocene catalyst polypropylene into a film product; (C) A film product according to the method comprising drawing a film product at a draw ratio of about 5.0: 1-10.0: 1 to produce a film product having a tenority of at least about 2.5 g / den. The film product of claim 13, wherein the monomer comprises propylene. The film article of claim 13, wherein the metallocene catalyst system comprises a crude catalyst. The film article of claim 13, wherein the crude catalyst comprises an organoaluminum compound. The film product of claim 13, wherein the metallocene catalyst system comprises at least one homogeneous catalyst system and a supported catalyst system. The film product of claim 13, wherein the polymerizing of the monomers is carried out in a loop reactor system. The method of claim 13, wherein the method is (i) extruding the metallocene catalyst polypropylene; (ii) drawing metallocene catalyst polypropylene through a die Film product comprising more. The film product of claim 13, wherein the polymerizing the monomer further comprises adding at least one additive. The method of claim 13, wherein the method is (i) processing the film product into a slit tape product, and further comprising slitting the film product. The method of claim 21 wherein the method is (i) a film product further comprising weaving the slit tape product into a fabric. The film product of claim 22, wherein the fabric comprises tenority within about 10.0 percent of the film product tenority. The method of claim 13, wherein the method is (i) a film product further comprising weaving the film product into a fabric. The film product of claim 24, wherein the fabric comprises tenority within about 10.0 percent of the film product tenority. The film article of claim 13, wherein the metallocene catalyst polypropylene further comprises a metallocene catalyst isotactic polypropylene. The film product of claim 13, wherein the film product comprises up to about 99.0 percent isotacticity. (A) extrude a metallocene catalyst polypropylene; (B) forming the metallocene catalyst polypropylene into an almost flat product; (C) cool the nearly flat product; (D) A method of making a metallocene catalyst polypropylene film product having a tenority of at least about 2.5 g / den, comprising stretching an almost flat product to a metallocene catalyst polypropylene film product. 29. The method of claim 28, wherein said molding further comprises forming a substantially flat product using a die. 29. The method of claim 28, wherein said cooling step (i) at least one cooling roller; And (ii) at least one quench bath And cooling the substantially flat product with a cooling device selected from the group consisting of: 31. The method of claim 30, wherein the at least one cooling roller cools the near flat product to a temperature of about 30-60 ° C. The method of claim 28, wherein said stretching step (i) heating a nearly flat product; (ii) draw a nearly flat product; (iii) annealing almost flat products How to include more. 33. The method of claim 32, further comprising heating the substantially flat product to a temperature of about 130-180 ° C. 33. The method of claim 32, wherein said drawing further comprises drawing a substantially flat product at a draw ratio of about 5.0: 1-10.0: 1. 33. The method of claim 32, wherein the draw further comprises drawing a substantially flat product at a draw ratio of 9.25: 1. 33. The method of claim 32, wherein the annealing further comprises heating the substantially flat product to a temperature of about 130-170 ° C. The method of claim 28, (i) processing the film product into a slit tape product. 38. The method of claim 37, further comprising weaving the slit tape article into a woven article. The method of claim 38, wherein the woven product comprises tenority within about 10.0 percent of the film product tenority. The method of claim 28, (i) further comprising weaving the film product into the woven product. 41. The method of claim 40, wherein the woven product comprises tenority within about 10.0 percent of the film product tenority. (A) feeding the slit tape to the loom, which is intended to be stored in the loom beam; (B) Weaving slit tapes into woven products with tenority within 10.0 percent of slit tape tenority A method of weaving a woven product from a slit tape having a tenority of 2.5 g / den, comprising a processed metallocene catalyst polypropylene film product. 43. The method of claim 42, wherein the weaving step further comprises weaving a plurality of fill yarns into a woven product. 43. The method of claim 42, wherein the woven product has tenority within 10.0 percent of the metallocene catalyzed polypropylene film product tenority.

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