CN1784459A - Alkyl acrylate copolymer modified oriented polypropylene films,tapes,fibers and nonwoven textiles - Google Patents

Abstract

Disclosed are films, tapes, slit film fibers and melt-spun fibers comprising (a) at least one polypropylene polymer selected from the group consisting of polypropylene homopolymers; random copolymers or block copolymers of polypropylene and ethylene; and random terpolymers or block terpolymers of polypropylene, ethylene and one other olefin; and (b) from 1 to 30 weight % of at least one ethylene/ alkyl acrylate copolymer. The tapes can be stretched (i.e. uniaxially oriented) to provide monofilament slit film fibers. Also disclosed are processes for preparing such fibers. Also disclosed are nonwoven textiles prepared from the melt-spun fibers.

Description

Oriented polypropylene films, tapes, fibers and nonwoven textiles modified with alkyl acrylate copolymers

                      

The present invention relates to films, tapes and fibers comprising polypropylene modified with ethylene/alkyl acrylate copolymers. The present invention also relates to nonwoven textiles prepared from melt-spun fibers prepared from these modified polypropylene compositions. The present invention also relates to a process for preparing slit fibers of these modified polypropylene compositions.

Background technique

Oriented films comprising polypropylene can be prepared using molten polymers by a variety of methods known in the art. The film can be oriented in one direction by thermally drawing in the machine direction and annealing using a stretching device. Films can also be oriented in two directions (machine and transverse) using suitable stretching equipment. Oriented polypropylene films are useful in a variety of packaging applications.

Fibers comprising polypropylene can be produced directly from the molten polymer by a variety of methods known in the art, including melt spinning, centrifugal spinning, and melt blowing.

Fibers can also be prepared from extruded polypropylene (PP) homopolymer or copolymer films. Flat films can be quenched by extrusion into a cooling water bath or onto chilled rolls. Alternatively, tubular blown film can be extruded through an annular die and air quenched. The quenched film was then slit into strips. These tapes are then thermally drawn in the machine direction by a stretching device and annealing the elongated tapes having a controlled width (e.g., about 2.5 mm to about 6.5 mm) to elongate (i.e., uniaxially orient) them to their original length. several times. The elongated ribbons provide monofilament fibers.

Melt-spun fibers can be incorporated into nonwoven textiles by a number of techniques, including dry-laying, wet-laying, air-laying, spunbonding, spray entangling, and needle punching. Nonwovens so produced can be used in a wide variety of applications including apparel, carpet backing, agricultural and geotextiles.

Polypropylene fibers can be used in string or rope or in the preparation of yarn for carpets. Polypropylene fibers can also be woven or knitted into fabrics for a variety of applications such as tarpaulins, padding, flags, bagging, carpet backing, agricultural and geotextiles.

In order to reduce the cost of weaving fabrics from elongated slit film flat yarns, it is necessary to:

Reduce the denier of the belt (the width remains the same but the thickness becomes thinner)

Increase the width of the tapes (with similar thickness) and reduce the structure of the woven fabric by reducing the number of tapes per dimension (e.g., from 8 x 8 tapes/square inch to a 5 x 5 tapes/square inch structure); and /or

• Increasing the amount of inert filler (eg CaCO ₃ ) in the polypropylene formulation.

It is very difficult to achieve all the above-mentioned objectives with conventional polypropylene compositions for making tapes. Higher elongation and reduced denier can lead to unacceptable loss of physical properties. Undesirable fibrillation of PP tapes at high elongation must also be overcome.

Likewise, there is a need to provide oriented polypropylene films and fibers with improved mechanical properties such as elongational break load, tensile strength (elongational break stress) and elongation at break.

Polypropylene fibers with improved mechanical properties have been prepared by adding small amounts of additives to polypropylene. For example PCT patent application publication WO 2003/048434 describes a process for preparing polypropylene monofilaments by adding 0.1 to 20% of an additive consisting of a combination of lubricant, filler and heat stabilizer. European patent EP0080274B1 describes the preparation of polypropylene melt-spun fibers by adding 0.1 to 10% of another polymer immiscible in molten polypropylene, in particular polyhexamethylene adipamide. Polypropylene is also modified by adding a small amount of liquid crystal polymer, polyethylene, polyethylene glycol and nylon 66 (Journal of Applied Polymer Science, 1986, 31 (8), 2753-68 (Journal of Applied Polymer Science, 1986, 31 (8), 2753-68)). The improvement in the mechanical properties of the modified composition was attributed to a reduction in spinning orientation or a suppression of winding speed.

Blends of polypropylene and ethylene/alkyl acrylate copolymers have been disclosed (see eg US Patent 3,433,573).

Invention Disclosure

The present invention relates to the improvement of mechanical properties such as elongational breaking load, tensile strength (elongational breaking stress) and elongation at break (%) of stretched polypropylene films and tapes and tensile strength of melt-spun polypropylene fibers And the improvement of elongation at break (%). These enhancements are achieved by adding small percentages (1 to 30, preferably 1 to 15% by weight) of ethylene/alkyl acrylate copolymers to PP formulations used to make films and fibers (PP formulations may optionally contain other fillers selected from (such as CaCO ₃ ) and additives (such as UV stabilizers, pigments, etc.) in materials). Blends of ethylene/alkyl acrylate copolymers with PP also improve the processability of PP resins by, for example, increasing the melt strength of molten PP resins. These blends provide improved stretchability and calendering of films and fibers over conventional polypropylene films and fibers. The calenderability of tapes made from these blends is improved during manufacture (ie, without or reduced tape fibrillation at increased calendering rates of the blends). The benefits of modified polypropylene blends include higher tensile strength at the same tape or fiber denier without loss in elongation at break.

Modified polypropylene blends can also reduce costs by producing finer denier polypropylene fibers with the same performance levels as unmodified fibers at the same equipment throughput conditions. Alternatively, higher throughputs with improved properties can be obtained for the same titer. The blends described herein reduce production downtime for most processes due to fewer interruptions.

It is an object of the present invention to improve the performance for films, melt-spun fibers, slit film flat yarns and fibers derived from them by adding ethylene/alkyl acrylate copolymers to PP resin formulations (for the preparation of polypropylene compositions). Mechanical properties of polypropylene compositions such as elongational load at break, tensile strength and elongation at break.

Another object of the present invention is to improve or maintain loading by incorporating certain levels of ethylene/alkyl acrylate copolymers in polypropylene formulations or using ethylene/alkyl acrylate copolymers as resin carriers (for loading fillers) Elastomeric properties of polypropylene homopolymer formulations with higher levels of inert fillers such as _CaCO3 . The goal is to improve the stretchability of films, tapes and slit fibers without loss of elongation properties.

Another object of the present invention is to improve the processability of PP formulations by adding small percentages of ethylene/alkyl acrylate copolymers. In general, cooling cast film (before slitting) with chill rolls is less efficient than cooling water baths. Stretchability of films cooled on chill rolls is poor because slower cooling results in more crystalline films. The addition of ethylene/alkyl acrylate copolymers increases the stretchability of the film and overcomes or reduces the fibrillation of slit flat yarns produced from such films during subsequent stretching. It also improves the calenderability of melt-spun fibers and improves the elongation properties of drawn fibers.

Another object of the present invention is to improve the tensile properties (elongational breaking load, tensile strength and elongation at break) of stretched tapes having a lower denier.

Additional benefits of the modified polypropylene blends described herein include improved uniformity of film and fiber thickness and width, reduced static, and improved abrasion resistance.

Accordingly, the present invention provides a film prepared from a composition comprising

(a) at least one polymer selected from the group consisting of polypropylene homopolymers, random or block copolymers of propylene and ethylene, ternary random or ternary block copolymers of propylene, ethylene and one other olefin Propylene polymers; and

(b) 1 to 30% by weight of at least one ethylene/alkyl acrylate copolymer.

The invention also provides a slit film flat yarn prepared from the film.

The present invention also provides fibers obtained by thermally drawing and annealing slit flat yarns prepared from said films.

The present invention further provides melt-spun fibers prepared from a composition comprising

(a) at least one polymer selected from the group consisting of polypropylene homopolymers, random or block copolymers of propylene and ethylene, ternary random or ternary block copolymers of propylene, ethylene and one other olefin Propylene polymers; and

(b) 1 to 15% by weight of at least one ethylene/alkyl acrylate copolymer.

The present invention also provides nonwoven textiles prepared from melt-spun fibers as described above.

Benefits of using the modified polypropylene blends described herein include improvements in tensile strength, "low speed" perforation, and "high speed" perforation.

The present invention also provides films, slit film flat yarns, fibers (such as slit film fibers or melt-spun fibers) and non-woven textiles, wherein the composition as described above further comprises (c) 0.01 to 40% by weight of at least one selected from Additional components of fillers, matting agents, UV stabilizers, pigments and other additives.

The present invention also provides a method of preparing slit fiber, the method comprising:

(1) Prepare a composition comprising the following components

(a) at least one polymer selected from the group consisting of polypropylene homopolymers, random or block copolymers of propylene and ethylene, ternary random or ternary block copolymers of propylene, ethylene and one other olefin Propylene polymer;

(b) 1 to 30% by weight of at least one ethylene/alkyl acrylate copolymer; and optionally

(c) 0.01 to 40% by weight of at least one additional component selected from fillers, matting agents, UV stabilizers, pigments and other additives;

(2) forming the composition into a film;

(3) cutting the film into strips;

(4) Hot drawing and annealing the tape of step (3).

Detailed description of the invention

"Copolymer" means a polymer comprising two or more different monomers. The terms "copolymer" and "terpolymer" refer to polymers comprising only two and three different monomers, respectively. The phrase "copolymer of various monomers" means a copolymer whose units are derived from various monomers.

As noted above, the films, tapes and fibers of the present invention are prepared from compositions comprising polypropylene resins modified with ethylene/alkyl acrylate copolymers.

Polypropylene (abbreviated as PP) polymers include homopolymers, random copolymers, block copolymers and terpolymers of propylene. Propylene copolymers include copolymers of propylene and other olefins such as ethylene, 1-butene, 2-butene, and various pentene isomers, etc., and are preferably copolymers of propylene and ethylene. Terpolymers of propylene include copolymers of propylene with ethylene and one other olefin. Random copolymers (also called statistical copolymers) are polymers in which propylene and comonomer are randomly distributed on the polymer chain in a ratio corresponding to the propylene/comonomer feed ratio. Block copolymers consist of chain segments consisting of homopolymers of propylene and chain segments of eg random copolymers of propylene and ethylene. The term "polypropylene" as used herein generally refers to any or all polymers comprising propylene as described above.

Polypropylene homopolymers or random copolymers can be prepared by any known method. Polypropylene polymers, for example, can be produced in the presence of Ziegler-Natta catalyst systems based on organometallic compounds and solids comprising titanium trichloride.

Block copolymers can be prepared in a similar manner, except that propylene is usually self-polymerized first in the first stage, followed by propylene and additional comonomers (e.g. ethylene) in the second stage. polymerization in the presence of . Each of these stages can be carried out continuously or discontinuously in the same reactor or in separate different reactors, for example in suspension in a hydrocarbon diluent, in suspension in liquid propylene or in the gaseous state.

Additional information on block copolymers and their preparation can be found inter alia in Chapters 4.4 and 4.7 of "Block Copolymers", edited by D.C. Allport and W.H. Janes, Applied Science Publishers, Inc., 1973 ( chapters 4.4 and 4.7 of the work "Block Copolymers" edited by D.C.Allport and W.H.Janes, published by Applied Science Publishers Ltd in 1973), which is incorporated herein by reference.

The term "ethylene/alkyl acrylate copolymer" includes copolymers of ethylene and alkyl acrylate wherein the alkyl moiety contains 1 to 6 carbon atoms. Examples of alkyl acrylates include methyl acrylate, ethyl acrylate, and butyl acrylate. "Ethylene/methyl acrylate (abbreviated EMA)" means a copolymer of ethylene (abbreviated E) and methyl acrylate (abbreviated MA). "Ethylene/ethyl acrylate (abbreviated EEA)" means a copolymer of ethylene (abbreviated E) and ethyl acrylate (abbreviated EA). "Ethylene/butyl acrylate (abbreviated EBA)" means a copolymer of ethylene (abbreviated E) and butyl acrylate (abbreviated BA).

The relative amount of alkyl acrylate comonomer added to the ethylene/alkyl acrylate copolymer can vary in principle over a wide range, from very few weight percents up to 40% or more of the total weight of the copolymer. Likewise, the choice of alkyl group can in principle also range from simple methyl up to 6 carbon atom alkyl groups (with or without significant branching). The relative amount and selection of the alkyl group in the alkyl acrylate comonomer can be seen as a factor in determining how and to what extent the resulting ethylene copolymer will function as the polar polymer component in the thermoplastic composition.

Preferably the alkyl group in the alkyl acrylate comonomer has 1 to 4 carbon atoms and the concentration of the alkyl acrylate comonomer is 5 to 30% by weight of the ethylene/alkyl acrylate copolymer, preferably 10 to 25 %weight. Most preferably the alkyl group in the alkyl acrylate comonomer is methyl.

Ethylene/alkyl acrylate copolymers can be prepared by methods well known in the polymer art using autoclaves or tubular reactors. Copolymerization can be carried out in an autoclave as a continuous process: ethylene, alkyl acrylate, and optionally solvent (e.g., methanol) (see U.S. Patent 5,028,674) are fed continuously to a stirred tank of the type disclosed in U.S. Patent 2,897,183 containing an initiator. in an autoclave. The rate of addition depends on variables such as polymerization temperature, pressure, alkyl acrylate monomer employed and the monomer concentration in the reaction mixture needed to achieve the target copolymer composition. In some cases, it may be necessary to use telogens such as propane to control molecular weight. The reaction mixture was continuously removed from the autoclave. After the reaction mixture leaves the reaction vessel, the copolymer is separated from unreacted monomer and solvent (if solvent is used) by conventional means, such as evaporation of unpolymerized material and solvent under reduced pressure and elevated temperature.

As is generally known in the art, tubular reactor produced ethylene/alkyl acrylate copolymers can be distinguished from more conventional autoclave produced ethylene/alkyl acrylates. Thus, the term or phrase "tubular reactor prepared" ethylene/alkyl acrylate copolymers means, for the purposes of the present invention, ethylene copolymers prepared at high pressure and temperature in a tubular reactor or similar , where the inherently different reaction kinetics of ethylene and alkyl acrylate comonomers are moderated or partially compensated by the deliberate introduction of the monomers along the reaction flow path in a tubular reactor. As generally known in the art, this tubular reactor copolymerization technique produces copolymers with a higher degree of relative heterogeneity along the polymer backbone (copolymers that are more closely distributed in blocks) to reduce long-chain Branching is present and produces copolymers characterized by higher melting points relative to copolymers prepared in high pressure stirred autoclave reactors with the same comonomer ratios. In general, the rigidity and elasticity of ethylene/alkyl acrylate copolymers prepared in tubular reactors are higher than those of ethylene/alkyl acrylate copolymers prepared in autoclave.

Tubular reactor-produced ethylene/alkyl acrylate copolymers of this nature are commercially available from E.I. du Pont de Nemours & Co., Wilmington, Delaware.

The actual preparation of the aforementioned tubular reactor ethylene/alkyl acrylate copolymer is preferably carried out in a tubular reactor at high temperature and pressure with additional reactant comonomer introduced along the reaction tube, while And not just in stirred high temperature and high pressure autoclave reactors. However, it is understood that similar ethylene/alkyl acrylate copolymer materials can be prepared in a series of autoclave reactors where comonomer replacement is achieved by multiple zone introduction of reactant comonomers, as described in U.S. Patent 3,350,372, 3,756,996 and 5,532,066 taught. Again, these high melting point materials should be considered equally for the purposes of the present invention.

To further illustrate and describe the comparison of ethylene/alkyl acrylate copolymers prepared in tubular reactors with conventional autoclave prepared copolymers, the following commercially available ethylene/methyl acrylate copolymers and their melting point data show tubular EMA resins have significantly higher melting points relative to autoclave EMA due to a very different MA distribution along the polymer chain:

Copolymers prepared in autoclave

EMA-A1 (21.5% by weight of MA) mp = 76°C

EMA-A2 (24% by weight of MA) mp = 69°C

EMA-A3 (20% by weight of MA) mp = 80°C

EMA-A4 (24 wt% MA) mp = 73°C.

Copolymers prepared in a tubular reactor

EMA-T1 (25% by weight of MA) mp = 88°C

EMA-T2 (20 wt% MA) mp = 95°C.

For an additional discussion of the differences between tubular reactor-produced and autoclave-produced ethylene/alkyl acrylate copolymers see Richard T. Chou, Mimi Y. Keating and Lester J. Hughes presented at the Plastics Engineering Society Annual Technical Meeting (2002), 60th (Volume 2), pp. 1832-1836 "High Flexibility EMA Made by High-Pressure Tubular Process" (Richard T. Chou, Mimi Y. Keating and Lester J. Hughes, "High Flexibility EMAmade from High Pressure Tubular Process", Annual Technical Conference-Society of Plastics Engineers (2002), 60th (Vol. 2), 1832-1836). CODEN: ACPED4 ISSN: 0272-5223; AN 2002: 572809; CAPLUS.

Ethylene/alkyl acrylate copolymers suitable for use in the present invention are available from DuPont. Specific examples of tubular reactor made ethylene/alkyl acrylate copolymers available from DuPont are shown in Table A.

Table A Ethylene alkyl acrylate copolymer Alkyl Acrylate % by weight Melt flow (g/10min) EMAEMAEMAEMAEMAEMAEMAEMAEMAEEAEEAEEAEEAEBAEBAEBAEBAEBAEBA 2525914182492013121615157717172717 0.40.6222268911671.11.11.51.847

The molecular weight of the ethylene/alkyl acrylate copolymers suitable for use in the present invention can vary considerably, as evidenced by an EMA with a melt flow index value up to about 10. The degree of specific selection of the ethylene/alkyl acrylate copolymer component for modifying polypropylene is influenced by balancing factors such as the melt flow index of the modifier and the polypropylene, the relationship between the ethylene/alkyl acrylate copolymer and Stretching temperatures and expected stretching profiles (stretching rate and stretching ratio) for the respective softening points of the polypropylenes. Other factors to consider in the selection of ethylene/alkyl acrylate copolymers include the increased elastic recovery associated with higher relative molecular weight copolymers (e.g., with an E/25% by weight MA of 0.7MI) and the relative lower molecular weight Copolymers (eg, with an E of 8 MI/20% by weight MA) are associated with a practical ability to more easily blend fillers (see below).

The composition of ethylene/alkyl acrylate copolymer and polypropylene used in the present invention can be mixed by dry blending, pellet blending, melt blending, by extruding a mixture of the various components and other methods known in the art method to prepare.

Compositions for use in the present invention may optionally further comprise fillers such as calcium carbonate ( _CaCO3 ) in amounts up to 30 to 40% by weight of the tape composition. For example, 0.01 to 20% by weight, 0.1 to 15% by weight, about 2 to about 10% by weight _CaCO3 may be present in some slit film flat yarns. The ethylene/alkyl acrylate copolymers described herein enhance the compatibility between polypropylene-based resins and optional fillers. Improved compatibility results in reduced "dusting" intensity (resulting from separation of filler and polypropylene resin), fewer _CaCO3 particles in the air during processing operations, and reduced wear and tear on weaving or knitting equipment. The use of the ethylene/alkyl acrylate copolymer modifiers described herein also provides higher filler loadings.

The composition used in the present invention may optionally further comprise other additives such as matting agents (eg TiO ₂ ), UV stabilizers, pigments and the like. These additives are well known in the art of film, slit film fibers and melt spun fibers. These conventional ingredients may be present in the compositions of the invention in amounts of 0.01 to 20% by weight, preferably 0.1 to 15% by weight.

Optional addition of such conventional ingredients to compositions comprising polypropylene modified with ethylene/alkyl acrylate copolymers can be carried out by any known method. Such incorporation can be performed by, for example, dry blending, extruding a mixture of the various components, by conventional color-concentrating techniques, and the like. A typical color concentrate may contain 75 to 90% by weight CaCO ₃ . Of note is the use of _CaCO3 -containing color concentrates and ethylene/alkyl acrylate copolymer modifiers.

The thermoplastic compositions described herein are suitable for use in the production of films and fibers by extrusion processing.

The films of the present invention, which can be used to make slit flat yarns and fibers, can be prepared by any film-forming method known to those skilled in the art. Thus, films and film structures can generally be cast, extruded, coextruded, etc. including orientation (uniaxial or biaxial), by various methods (eg, blown film, mechanical stretching, etc.). It is understood that various additives commonly practiced in the art may be present in the respective film layers (including in composite film tie layers, etc.), provided that their presence does not substantially alter the properties of the film or film structure . Therefore, it can be expected to be beneficial to employ various additives such as antioxidants and heat stabilizers, ultraviolet (UV) light stabilizers, pigments and dyes, fillers, matting agents, anti-slip agents, plasticizers and other processing aids, etc. .

In one embodiment, the film is formed by an extrusion process that results in the alignment of the polymer chains in the film generally along the direction of extrusion. Linear polymers, after being highly uniaxially oriented, have significant strength in the orientation direction and less strength in the transverse direction. This alignment adds strength to the film in the direction of extrusion (corresponding to the length dimension of the slit veil). Alternatively, films can be prepared by blowing methods known to those skilled in the art.

The present invention provides films prepared from compositions comprising polypropylene and ethylene/alkyl acrylate copolymers. The film can be unoriented, oriented in a uniaxial direction (eg, machine direction), or oriented in a biaxial direction (eg, machine direction and transverse direction).

Films are used in a wide range of packaging applications, including shrink films. As mentioned above, the films can also be used to make slit flat yarns and fibers.

Preferred films of the present invention include:

Preferred 1. A film wherein the amount of said alkyl acrylate in said ethylene/alkyl acrylate copolymer is from about 5 to about 30% by weight.

Preferred 2. The film of Preferred 1 wherein the amount of said alkyl acrylate in said ethylene/alkyl acrylate copolymer is from about 10 to about 25% by weight.

Preferred 3. The film of Preferred 2, wherein the alkyl acrylate is selected from methyl acrylate, ethyl acrylate and butyl acrylate.

Preferred 4. The film of Preferred 3, wherein the alkyl acrylate is methyl acrylate.

Preferred 5. The film of any one of Preferred 1 to Preferred 4, wherein the amount of component (b) is 2 to 30%, or 2 to 20%, or 2 to 10% by weight of the total composition.

Preferred 6. The film according to any one of Preferred 1 to Preferred 5, which further comprises

(c) 0.01 to 40% by weight of at least one additional component selected from fillers, matting agents, UV stabilizers, pigments and other additives.

Preferred 7. The film of Preferred 6, wherein said component (c) is present in an amount of 0.1 to 15% by weight.

Preferred 8. The film of any one of Preferred 1 to Preferred 7, which is produced by quenching the composition by extrusion into a cooling water bath.

Preferred 9. The film according to any one of Preferred 1 to Preferred 7, which is produced by quenching the composition by extruding it into a cooling roll.

Preferred 10. The film of any one of Preferred 1 to Preferred 7, which film is produced by extruding said composition through an annular die into an air-cooled tubular blown film.

Preferred 11. The film of any one of Preferred 1 to Preferred 10, wherein the composition comprises a tubular reactor produced ethylene/alkyl acrylate copolymer.

The present invention also provides a slit film flat yarn produced from the film of the present invention. Preferred tapes are made from the preferred films described above.

The present invention also provides fibers obtained by hot-drawing and annealing slit flat yarns obtained from said films. Preferred fibers are made from tapes (prepared from the preferred films described above).

The present invention also provides methods of making slit fibers. A preferred method is to use the preferred films described above.

As mentioned, slit film fibers are formed from polymeric materials that are formed into films, cut into tapes, and thermally drawn.

Woven or knitted textiles can be made from the aforementioned slit fibers. Preferred woven or knitted textiles are made from the preferred fibers described above.

Methods for preparing slit fibers based on polypropylene polymers by cutting films extruded from compositions comprising such polymers are well known. Common uses for these slit monofilament fibers include rope and twine manufacturing, fibers for synthetic fine screens and woven fabrics for bagging, carpet backing or geotextiles.

The preparation of slit fibers from the composition described above can itself be carried out according to any known method. It is possible, for example, to prepare primary films by extruding the composition using the so-called "blown film" or "flat die" method. Blown films are produced by extruding the polymer composition through an annular die and expanding the resulting tubular film with an air stream to provide a blown film. Cast flat films are made by extruding the composition through a flat die. The film leaving the die is passed through at least one roll containing a circulating fluid (chill roll) or cooled by a water bath to provide a cast film. Films of the present invention have a width of, for example, about 60 cm (2 feet). This primary film is then cut into slit flat yarns which are drawn into monofilament fibers before being wound up on rolls.

Slit film flat filaments may be prepared using a cutting device comprising a frame, a plurality of substantially coplanar cutting knives each comprising opposite edges and opposite ends for mounting the cutting knives to the frame The assembly structure and the feed roller connected to the bracket and configured to feed the film in the downstream direction over the exposed cutting edge of the blade. The mounting structure is configured to mount the cutting knives in substantially one row, parallel and spaced apart relationship, wherein the blades are mounted such that each blade exposes one of its cutting edges for cutting, and wherein the cutting edges of adjacent blades are spaced apart from each other by About 6mm to 8mm.

After cutting the film into tapes as described above, the stretching operation will be performed over a span of 3 to 6 meters (10 to 20 feet) in an oven heated to a temperature effective to soften the film to facilitate the stretching operation. What typically happens is that the film is cold at the start of its passage through the oven and is gradually heated and softened as the film passes through the oven. Necking occurs on the neckline located at some distance from the oven entrance. The location of the necked zone depends on a variety of factors, including draw speed, oven temperature, and the properties and thickness of the film material. A typical pre-stretched tape has a thickness of about 120 microns and a width of about 6 mm to 8 mm. After stretching, the resulting tape has a thickness of about 30 to 50 microns and a width of about 2.5 mm to 3 mm. Wider or narrower tapes can be prepared for specific applications. For example, the fibers used in the reduced filament count woven fabric have a final width of about 4 mm to about 6 mm. The polypropylene tapes were spun to a final width of about 10 mm to 15 mm.

Draw ratios generally range from about 2:1 to about 16:1, with typical draw ratios for some polymers ranging from about 4:1 to about 10:1. The stretch ratio of the woven tape is preferably from about 5:1 to about 8:1. Draw ratios for wider slit ribbons are typically from about 10:1 to about 15:1. The distance over which longitudinal stretching occurs varies according to the technique employed. In short stretches, the stretching occurs over a distance of a few inches, and other techniques include greater distances. After heat drawing, the resulting monofilament fibers for woven tapes typically have a denier of about 700 to about 1700. Polypropylene tapes are spun to a denier of about 3000 to about 6000.

The mechanical properties of the tapes of the present invention, such as tensile strength, elongational load at break, elongation at break, and denier, can be balanced by adjusting various parameters, including

· Resin formulation design (base resin, level and type of additives added ( _CaCO3 , UV stabilizers, pigments));

The amount and type of ethylene/alkyl acrylate employed;

· Film and tape processing equipment (cooling, cutting, stretching and annealing configurations); and

Processing conditions (extruder screw configuration, temperature profile and polymer throughput, stretching and annealing temperature and profile, line speed, etc.)

In general, manufacturing facilities used to make slit veils have limited ability to modify equipment and processing conditions. Thus, the ethylene/alkyl acrylate modification of the polypropylene resins of the present invention can significantly improve the mechanical properties of films, tapes and yarns prepared from them.

As noted above, fibers can also be prepared directly by extrusion processes, including centrifugal spinning, melt spinning, spunbonding, and meltblowing.

In centrifugal spinning, fibers are formed when a polymer melt is accelerated by a rapidly rotating source. Molten material from the furnace is conveyed to a rotary spinner where centrifugal force extrudes the material through small holes in the side of the spinning unit to produce fibers.

In melt spinning, the fiber-forming substance is melted, extruded through a spinneret and then directly solidified by cooling. Melt-spun fibers can be extruded from spinnerets in different cross-sectional shapes (circular, trilobal, five-lobal, octalobal, etc.). In-line drawing is accomplished by winding the moving filament around a set of rotating rolls operating at controlled temperature and speed. Depending on the specific melt spinning process and the corresponding processing steps, the product can be collected in the form of monofilaments, yarns, tows or nonwovens (eg spunbond). For a general reference on melt spun fibers see Synthetic Polymer Fibers , edited by Rowland Hill, Elsevier Publishing Co., NY, 1953 (Fibers FRom Synthetic Polymers, Rowland Hill, ed., Elsevier Publishing Co., NY, 1953).

Spunbond is the direct lay-up of a nonwoven web from melt-spun fibers. Continuous filaments are extruded through a spinneret, accelerated (by rollers or jets) and laid down on a moving belt to form a nonwoven. Bonding occurs at the intersections of molten fibers.

Meltblowing is another direct lay-up method in which fibers are extruded through a die tip, attenuated (and broken) by hot, high-velocity air, and deposited onto a moving belt or screen to form a microfine (low denier) fiber web.

Spunbond (S) and meltblown (M) webs after formation can be further bonded and/or patterned by calendering. Multilayer nonwovens (eg SMS, SMMS, SMMMS) can also be prepared using the fibers of the present invention.

The present invention further provides melt-spun fibers prepared from the above composition. Preferred melt-spun fibers include:

Preferred A. Fibers wherein the amount of said alkyl acrylate in said ethylene/alkyl acrylate copolymer is from about 5 to about 30% by weight.

Preferred B. The fiber of Preferred A wherein the amount of said alkyl acrylate in said ethylene/alkyl acrylate copolymer is from about 10 to about 25% by weight.

Preferred C. The fiber of Preferred B wherein the alkyl acrylate is selected from the group consisting of methyl acrylate, ethyl acrylate and butyl acrylate.

Preferred D. The fiber of Preferred C wherein the alkyl acrylate is methyl acrylate.

Preferred E. The fiber of any one of Preferred A to Preferred D, wherein said component (b) is present in an amount of 2 to 10% by weight.

Preferred F. The fiber of any one of Preferred A to Preferred E, said fiber further comprising

(c) 0.01 to 15% by weight of at least one additional component selected from fillers, matting agents, UV stabilizers, pigments and other additives.

Preferred G. The fiber of Preferred F, wherein said component (c) is present in an amount of 0.1 to 5% by weight.

Preferred H. The fiber of any of Preferreds A to Preferred G, wherein the composition comprises a tubular reactor produced ethylene/alkyl acrylate copolymer.

Nonwoven textiles can be prepared from melt-spun fibers as described above. Preferred nonwoven textiles are prepared from the preferred fibers described above.

Woven or knitted textiles can be prepared from melt-spun fibers as described above. Preferred woven or knitted textiles are prepared from the preferred fibers mentioned above.

Oriented films are used in a wide variety of packaging applications. As noted above, the films of the present invention are also useful in the preparation of slit strand fibers.

Fibers prepared as described herein, including slit strand fibers, can be used to make cords, strings, or ropes. A number of fibers are joined together by, for example, twisting, weaving, interlacing, etc. to form a cord. Strings generally contain a lower number of fibers and are smaller in diameter than cords. These cords, cords or cords may be roughly round or flat in cross-section. Cords or strings are used in shoelaces, bag and briefcase straps, etc., and in packaging applications. Ropes are used in a wide variety of industrial and marine applications. Cords, strings, and cords can also be further interlaced (eg, by knitting) to produce nets with a relatively open structure, such as fishing nets, handling nets, and the like.

The slit strand fibers of the present invention are useful as monofilament fibers for carpet tufting, synthetic mesh, matting, and the like. They can also be used as ribbon spinning.

Woven or knitted textiles can be prepared from slit-spun fibers or melt-spun fibers as described above. In general, woven fabrics can have a tighter structure than knitted fabrics. Polypropylene yarns prepared as described herein can be woven into applications such as filters, tarpaulins, canopies, canopies, flags, structural (e.g. roofing) membranes, machine belts, trunk or packing liners, heavy duty Sackcloths, carpet backings, furniture backings, apparel, agricultural fabrics (for seed inspection, weed control, horticulture, greenhouses and silage) and geotextiles (for erosion control and soil retention). Knitted fabrics are used in sackcloth (for carrying bulky materials such as groceries, firewood, etc.) as well as in construction, industry and fishing nets.

Woven fabrics using the modified polypropylene compositions described herein have a lower tendency to slip, especially for load-bearing bags.

The nonwoven textiles of the present invention can be used in diapers and other articles for personal hygiene (such as adult incontinence) and feminine hygiene products, medical clothing such as caps, gowns, baby socks, personal protective equipment including masks, etc., sanitary protective equipment such as drapes , covers, blankets, etc., wrappings, durable paper, wipes, coverings, flags, carpet backing, filter cloths, geotextiles, agricultural cloths, furniture backings, clothing, filters, pads or for building Building coverings for heat and moisture control.

For carpet backings, shrinkage of the textile is important (eg, less than 2.5% shrinkage at 45°C is desirable). Woven and nonwoven carpet backings are commonly used as the primary backing for carpets to provide strength, dimensional stability and shape to the carpet. They can be prepared from the spun-strip fibers or spunbond fabrics of the present invention.

The secondary carpet backing can be used to provide a backing to which the carpet yarns are fastened. They can be made from nonwoven materials. The melt-spun fibers of the present invention can be used to prepare nonwoven substrates that can be used as secondary carpet backings.

Geotextiles can be used under the gravel and pavement layers of roads to improve road quality. Geotextile fabrics are usually manufactured from woven PP tapes with a width of about 2.5 mm. Geotextiles can also be prepared from spunbond nonwovens obtained from melt-spun fibers. The shrinkage requirements for geotextiles are not as stringent as those for carpet backing. However, puncture resistance is extremely important for geotextiles.

While the present invention has been particularly illustrated and described with reference to preferred embodiments, it will be understood by those skilled in the art that various changes in form and details may be made without departing from the spirit and scope of the invention.

The following examples are for illustration only and should not be construed as limiting the scope of the inventions described and/or claimed herein.

Example

Cut film flat yarn

test 1

The tests were carried out on an extrusion caster using the resin formulations described below. The film was cast onto chilled (quench) rolls. The films were then cut into tapes and stretched 6 or 7X to 5 mm tapes in an annealing oven. The stretching and annealing of the ribbons are carried out simultaneously. Samples were taken 15 minutes after the manufacturing process and tested for tensile strength. A 250 mm long strip with a width of 5.0 mm was stretched on a universal tensile testing machine with a crosshead separation speed of 200 mm/min. The results are shown in Table 2.

materials used

PP-1: Polypropylene homopolymer with a melt index (MI) of 3 g/10 min (ASTM D-1238, 230° C., with a mass of 2.16 Kg), obtained from Titan Petrochemical (M) Sdn Bhd.

EMA-1: Ethylene/alkyl acrylate copolymer, containing 24% by weight of methyl acrylate, MI is 2g/10min (ASTM D-1238, 190°C, using 2.16Kg mass).

calcium carbonate as filler

Resin preparation:

Comparative Example C1: PP-1 (99%)+CaCO ₃ (1%)

Embodiment 2: PP-1 (89%)+CaCO ₃ (1%)+EMA-1 (10%)

Embodiment 3: PP-1 (94%)+CaCO ₃ (1%)+EMA-1 (5%)

Table 2 Comparative Example C1 Example 2 Example 2 Example 3 Tensile ratio Denier Tensile load at break (Kgf) Tensile strength (g denier) Elongation at break (%) 6-------- 6.129635.025.21231 7.0511786.055.13627 610585.244.95332

The test with comparative example C1 (0% EMA-1) was discontinued because of poor processability and instability under the conditions used for examples 2 and 3 (10% and 5% EMA-1). Fibrillation of the tape produced from comparative example 1 occurred during the test even at a draw ratio of 6.

Under normal production conditions using a neat PP formulation (see comparative example 1), the cast film is not stable at high extruder throughput (eg extruder screw speed above 180 rpm). Machine throughput is low and thus throughput is also reduced. Furthermore, if the draw ratio is increased beyond about 6, ribbon fibrillation begins to occur and the width of the ribbons is very non-uniform.

By adding 5 to 10% of an EMA resin such as EMA-1 to the PP formulation, production runs very smoothly under high throughput conditions and the cast film from the extruder is very stable. The new formulations have better processability and improved melt strength.

Slit film tape can be elongated up to 6 to 7 times with no tendency to fibrillation. The mechanical properties of the oriented tapes, such as tensile strength, elongational load to break and elongation at break, were satisfactory.

test 2

This test was carried out on an extrusion cast machine. The film was quenched in a cooling water bath. The films were then cut into tapes and stretched at least 6X to 3 mm tapes in an annealing oven. The stretching and annealing of the ribbons are carried out simultaneously. Samples were taken 15 minutes into the manufacturing process and tested for tensile strength. A 250mm long strip with a width of 3.0mm was stretched on a universal tensile testing machine with a crosshead separation speed of 200mm/min. The results are shown in Table 3.

materials used

PP-2: Polypropylene homopolymer resin with a melt index (MI) of 3 g/10 min (ASTMD-1238, 230°C/2.16 Kg), available from Titan Petrochemical (M) Sdn Bhd under the name PD855.

Ethylene/alkyl acrylate copolymer containing 24% by weight of methyl acrylate (EMA-1), MI 2g/10min (ASTM D-1238, 190°C/2.16Kg).

White concentrate, colorant/filler containing _CaCO3 .

Resin preparation

Comparative examples C4 and C6: PP-2 (95%)+ white concentrated color body (5%)

Examples 5 and 7 to 9: PP-2 (90%) + white concentrated body (5%) + EMA-1 (5%)

table 3 Comparative Example C4 Example 5 Comparative Example C6 Example 7 Example 8 Example 9 Tensile ratio denier Tensile load at break (Kgf) Tensile strength (g/denier) Elongation at break (%) 68864.85.431 68585.16.033 610755.65.230 610965.85.341 810166.76.826 77364.66.228

These test results demonstrate that the addition of 5% ethylene/alkyl acrylate copolymer to PP improves the mechanical properties of oriented PP tapes, such as elongational breaking load, elongation at break and tensile strength.

Comparing tapes with similar average denier (Comparative Example C4 and Example 5, Comparative Example C6 and Example 7), the tapes made from PP with 5% EMA added show similar tensile strength relative to standard PP tapes. Improved average elongation load at break, average elongation at break, and average tensile strength over lower tensile.

Improved average elongation at break and average tensile strength of modified PP tape (Example 8) at higher draw ratio (8X) compared to standard (Comparative Example C6) prepared at standard draw ratio (6X) ) or the modified PP tape (Example 7) is even more pronounced.

The tensile properties of the modified PP tape with a lower average denier (Example 5) are almost as high as the standard PP tape with a higher average denier (Comparative Example C6). The modified PP low-denier tape (Example 9) prepared with a high draw ratio (7X) had similar average elongation load at break and elongation at break to the standard PP tape (Comparative Example C4), but had a higher tensile strength.

Test 3

In these tests, various fibers were prepared in a manner suitable for incorporation into woven fabrics suitable for use in geotextiles.

PP-3: base polypropylene material prepared by blending polypropylene (Amoco GA 02, MFI: 1.8) with 2% by weight of colorant (Ampacet Noir 190826) and 3.5% by weight of _CaCO3 filler (Multibase ME 50004) prepared, labeled Comparative Example C10. The base material PP-3 was further blended with 3% by weight of polyolefin copolymer (Booster PO) to prepare Comparative Example 11. The base material PP-3 was blended with 5% by weight or 3% by weight of EMA-1 to prepare Comparative Examples 12 and 13.

Processing conditions

Extrusion temperature: 255°C

Oven (stretching): 163°C

Cooling roll: 27°C

Input: 270-300kg/hr

Cast film width: 1250mm

Cast film thickness: 175-180μm

Belt width before stretching: 6mm

Strip width after stretching: about 2.5mm

Processing started at 5% EMA-1 and a draw ratio of 7. The draw ratio was subsequently increased to 7.4 and 7.8 to improve strength.

Table 4 stretch ratio TEX[g/km] Strength [cN]/TEX Elongation C10C111212121212121213131313131313131313 6777.47.87.87.87.87.87.87.87.87.87.87.8888.28.2 172144140142142142148142 ¹ 143 ¹ 143143.6142.4143.8143.2140142.8141.4138138.6 4247-49454649.5484948.846.348.446.24847494950.747.853.549.5 302929.530.43029.530.828.827.427.528.128.527.328.42832.530.234.831.7

Note: 1.2 hours later. 2. Stretch roller adjustment. 3. The oven temperature is 160°C.

Tapes prepared from the composition of the invention demonstrated higher strength and similar elongation at higher draw ratio conditions compared to polypropylene (Example C10). Tapes prepared from compositions of the invention demonstrate slightly higher elongation and strength at higher draw ratio conditions than polypropylene plus 3% by weight Booster PO (Example C11).

In addition, use of the ethylene/alkyl acrylate modified compositions described herein allows for slightly lower energy consumption and slightly lower extruder pressures.

By adding ethylene/alkyl acrylate copolymer to PP formulation, it can be prepared

Highly stretched low denier tapes having very high elongational breaking load and tensile strength without significant loss in elongation; or

• Highly stretched high denier (wide but thin) tapes with good mechanical properties to reduce the cost of woven fiber bag or laminated substrate structures.

primary fiber

Test 4

The purpose of this test is to compare the spinning performance (maximum calenderability) and physical properties of PP yarns and PP/EMA blended yarns. The various yarns are drawn, wound and tested between pairs of heated rollers on the spinning machine. PP/EMA blends were melt blended before spinning.

materials used

Comparative Example C14: 100% PP-4 ( ^Profax® 6323)

Example 15: 95%/5% Blend of PP-4 and EMA-1

Example 16: 90%/10% Blend of PP-4 and EMA-1

Spinning conditions

Block material temperature 245℃

Spinneret 10 holes, 0.015 inches x 0.060 inches

Feed roller temperature 60℃

Feed roller speed 500 yards/minute (ypm)

Stretching roll temperature 80°C

The draw roll speed can be varied to determine the maximum draw (eg, 1500ypm for a 3X draw).

table 5 Example stretch ratio Yarn Denier Tensile strength (gd) Elongation(%) Modulus (gpd) average SD average SD average SD C14C1415151616 3.03.83.04.03.04.0 89.872.390.067.789.868.4 3.234.153.724.643.294.47 0.110.240.160.270.240.46 103.3866.65116.5160.82119.0363.14 9.786.596.367.2310.815.84 10.134.326.341.421.138.7 0.02.22.44.03.27.1

The addition of ethylene/alkyl acrylate copolymers increased the residual elongation and decreased the initial modulus of single-stage drawn melt-spun polypropylene fibers (indicating better calenderability). The addition also increases the maximum spin draw ratio resulting in desirably increased strength and/or reduced denier.

Trials 5 and 6

Two full-day spinning trials were performed. The first test was carried out with blends made on a twin-screw mixer (melt blend). The second test was performed with the polymer blend mixed in a tank mixer (dry blend). Blends were prepared with 5, 10 and 15% by weight of EMA-1.

The melt blend prepared on the twin-screw extruder was run in the first test:

Comparative example C17: 100% PP-5 (polypropylene, MFI is 4)

Example 18: 95%/5% Blend of PP-5 and EMA-1

Example 19: 90%/10% Blend of PP-5 and EMA-1

A dry blend prepared on a tank mixer was run in a second test:

Example 20: 95%/5% Blend of PP-5 and EMA-1

Example 21: 85%/15% Blend of PP-5 and EMA-1

Spinning conditions for the two tests:

Block material temperature 240℃

Melt temperature 240℃

Spinneret 600 holes

Feed roller temperature 137℃

Feeding roller speed 600rpm

Stretching roll temperature 23°C

The speed of the draw rolls is varied depending on the desired draw ratio (S.R.) (eg 1800 rpm corresponds to an S.R. of 3.0).

Table 6 melt blend Comparative Example C17 Example 18 Example 19 Maximum draw ratio 2.5 3.5 3.5 Tensile Specific Strength (g/den) Elongation at Break (%) Linear Density (den) Hardness (g/den) 1.93.02713057 2.53.9185235.4 1.93.0263306.6 2.53.9184235.3 34.41482148 1.92.9273305.8 2.53.61812548 34.2116213.7 dry blend Example 20 Example 21 Maximum draw ratio 3.5 3.5 Tensile Specific Strength (g/den) Elongation at Break (%) Linear Density (den) Hardness (g/den) 1.92.9246295.2 2.53.7168224.8 34.5135224.8 353.2229285.4 1.92.8254305.2 2.53.51762447 34.3136204.5 3.5599173.8

Blends of PP and EMA-1 spun well. The stretch ratio is significantly improved, along with increased strength. These tests showed higher elongation (no breakage) of PP with the addition of ethylene/alkyl acrylate copolymer. If the maximum draw ratio is 2.5 for 100% PP, adding 5, 10 or 15% by weight of EMA-1 increases the maximum draw ratio to 3.5. It can also be seen that the S.R. is increased while the tensile strength is increased, but the elongation at break is decreased.

Test 7

The purpose of this test was to evaluate the stretchability of films made from unmodified and modified PP on a tensile tester coupled to an oven running the test at elevated temperatures.

Materials used:

Comparative Example C22: 100% PP-6 (Moplen T 30 S)

Comparative Example C23: 90% PP-6+10% by weight Engage 8200 (metallocene catalyzed polyethylene)

Example 24: 95% PP-6 + 5% by weight EMA-1

Example 25: 90% PP-6 + 10% by weight EMA-1

We prepared 0.5 mm thick dumbbell-shaped samples and measured their tensile properties at 100°C. Above 100°C, the individual samples did not break within the limits of the test equipment (maximum 1500%). The results reported in Table 7 are the average of 20 samples of each formulation tested at 100°C.

Table 7 Example C22 C23 twenty four 25 Tensile Strength (MPa) Elongation at Break (%) 26.71366 19.91286 21.11371 22.51440

As shown in the table above, 10% EMA-1 showed a 5% improvement in elongation at break relative to 100% PP.

biaxially oriented film

Test 8

Individual samples were prepared from melt blended polypropylene and ethylene/alkyl acrylate copolymers and subsequently formed into cast films by extrusion. The equipment used to make biaxially oriented films has a gripper system that allows stretching in the machine and transverse directions.

Comparative example C26: 100% PP-7 (Basell HP 1078 polypropylene homopolymer, MFI is 2)

Example 27: EMA-1 of 95 weights of PP-7+5 weights

Example 28: 90% by weight of PP-7 + 10% by weight of EMA-1

The stretching conditions are as follows:

Stretching unit preheating: 30 or 40 seconds at 145°C

Fixture temperature: 82, 88, 100 or 105°C

Stretching speed: 400%/sec

Annealing temperature after stretching: 145°C Example stretch ratio Fixture temperature Preheat time Tensile strength MD Tensile strength TD Elongation at break MD Elongation at break TD C26 6×6 100 40 175 164 89 72 C26 6×6 100 40 169 168 91 85 27 6×6 100 40 164 178 88 99 27 6×6 100 40 176 184 89 75 28 6×6 100 40 160 152 98 106 28 6×6 100 40 161 177 88 87 28 6.5×6.5 100 40 177 176 76 83 C26 5×9 100 40 128 226 182 53 27 5×9 100 40 125 232 180 34 28 5×9 100 40 133 239 143 47 27 5×9 88 40 122 294 151 37 27 5×9 100 30 144 257 191 49 27 5×9 82 30 114 326 251 36 28 7×7 105 40 179 175 89 86 28 7×7 105 40 189 188 83 77

In the other tests mentioned above, the stretchability of the ethylene/alkyl acrylate modified polypropylene blend was higher than that of 100% PP using stretching rolls. In this test, stretchability comparisons are difficult because the film sometimes breaks on the jigs, which are very small (high stress concentrations) and have a large separation (approximately 10 cm) from each other. On industrial equipment, however, MD stretching is always performed with rolls rather than clamps.

However, it can be observed that higher tensile for some samples based on PP modified with EMA-1 gives better tensile strength and similar or higher elongation at break relative to 100% polypropylene.

For 7×7 stretched film made from 10% EMA-1, the tensile strength (average of MD and TD) is 8 times higher than 6×6 for 100% PP (maximum biaxial stretchability of PP) % and no loss of elongation at break.

For a 5×9 stretched film made from 5% EMA-1, the ratio of tensile strength (average of MD and TD) and elongation at break (average of MD and TD) ratios at the same stretch ratio of 5 The 100% PP of ×9 is 24% and 22% higher, respectively.

spunbond fabric

Test 9

The purpose of this test was to evaluate the effect of adding ethylene/alkyl acrylate copolymer to polypropylene to prepare spunbond fabrics.

Spunbond fabrics were produced by feeding a total of 68 spin positions using 2 extruders and laying the fibers onto a moving belt.

Comparative example C29: 100% polypropylene homopolymer PP-8 with a draw ratio of 2.5:1.

Example 30: 95% by weight PP-8 + 5% by weight EMA-1 with a draw ratio of 3:1.

The spinning condition of the fabric of embodiment 30 is:

Block material temperature 240℃

Melt temperature 240℃

Feed roller temperature 137℃

Feeding roller speed 600rpm

Stretching roll temperature 23°C

Stretching roller speed 1800rpm

These tests have shown that Example 30 provides improved stretchability. Example 30 was stretched at a ratio of 3:1, while Comparative Example C29 achieved a maximum stretch ratio of 2.5:1. The finished fabric Example 30 has significantly higher puncture resistance than the standard PP nonwoven (Comparative Example C29) at the same basis weight.

Claims (40)

1. A film prepared from a composition comprising: (a) at least one selected from the group consisting of polypropylene homopolymers, random or block copolymers of propylene and ethylene, terpolymers or ternary block copolymers of propylene, ethylene and one other olefin polypropylene polymers; and (b) 1 to 30% by weight of at least one ethylene/alkyl acrylate copolymer. 2. The film of claim 1 wherein the amount of said alkyl acrylate in said ethylene/alkyl acrylate copolymer is from about 5 to about 30% by weight. 3. The film of claim 3, wherein the amount of said alkyl acrylate in said ethylene/alkyl acrylate copolymer is from about 10 to about 25% by weight. 4. The film of any one of claims 1 to 3, wherein the alkyl acrylate is selected from the group consisting of methyl acrylate, ethyl acrylate and butyl acrylate. 5. The film of claim 4, wherein the alkyl acrylate is methyl acrylate. 6. The film according to any one of claims 1 to 5, wherein the amount of said component (b) is 2 to 30% by weight. 7. The film of claim 6, wherein the amount of said component (b) is 2 to 20% by weight. 8. The film of claim 6, wherein the amount of said component (b) is 2 to 10% by weight. 9. The film of any one of claims 1 to 8, wherein the composition further comprises: (c) 0.01 to 40% by weight of at least one additional component selected from fillers, matting agents, UV stabilizers, pigments and other additives. 10. The film of claim 9, wherein the amount of component (c) is 0.1 to 15% by weight. 11. The film of any one of claims 1 to 10 produced by quenching the composition by extrusion into a cooling water bath. 12. The film of any one of claims 1 to 10, produced by quenching the composition by extrusion onto a chill roll. 13. The film of any one of claims 1 to 10, produced by extruding the composition through an annular die to form a tubular blown film, and air quenching. 14. The film of any one of claims 1 to 13, wherein the composition comprises a tubular reactor produced ethylene/alkyl acrylate copolymer. 15. A tape produced by cutting the film according to any one of claims 1 to 14. 16. A fiber obtained by hot drawing and annealing the tape of claim 15. 17. A method of making fibers, the method comprising: (1) Prepare a composition comprising the following components (a) at least one selected from the group consisting of polypropylene homopolymers, random or block copolymers of propylene and ethylene, terpolymers or ternary block copolymers of propylene, ethylene and one other olefin polypropylene polymers; and (b) 1 to 30% by weight of at least one ethylene/alkyl acrylate copolymer; (2) forming the composition into a film; (3) cutting the film into strips; (4) Hot drawing and annealing the tape of step (3). 18. The method of claim 17, wherein the amount of said alkyl acrylate in said ethylene/alkyl acrylate copolymer is from about 5 to about 30% by weight. 19. The method of claim 18, wherein the amount of said alkyl acrylate in said ethylene/alkyl acrylate copolymer is from about 10 to about 25% by weight. 20. The method of any one of claims 17 to 19, wherein the alkyl acrylate is selected from methyl acrylate, ethyl acrylate and butyl acrylate. 21. The method of claim 20, wherein the alkyl acrylate is methyl acrylate. 22. The method of any one of claims 17 to 21, wherein the amount of component (b) is 2 to 30% by weight. 23. The method of claim 22, wherein the amount of component (b) is 2 to 20% by weight. 24. The method of claim 23, wherein the amount of component (b) is 2 to 10% by weight. 25. The method of any one of claims 17 to 24, wherein the composition further comprises: (c) 0.01 to 40% by weight of at least one additional component selected from fillers, matting agents, UV stabilizers, pigments and other additives. 26. The method of claim 21, wherein the amount of component (c) is 0.1 to 15% by weight. 27. The method of any one of claims 17 to 26, prepared by quenching the composition by extrusion into a cooling water bath. 28. The method of any one of claims 17 to 26, prepared by quenching the composition by extrusion onto chilled rolls. 29. The method of any one of claims 17 to 26, prepared by extruding the composition through an annular die to form a tubular blown film with simultaneous air quenching. 30. The method of any one of claims 17 to 29, wherein the composition comprises a tubular reactor produced ethylene/alkyl acrylate copolymer. 31. A melt-spun fiber prepared from a composition comprising: (a) at least one selected from the group consisting of polypropylene homopolymers, random or block copolymers of propylene and ethylene, terpolymers or ternary block copolymers of propylene, ethylene and one other olefin polypropylene polymers; and (b) 1 to 15% by weight of at least one ethylene/alkyl acrylate copolymer. 32. The fiber of claim 31, wherein the amount of said alkyl acrylate in said ethylene/alkyl acrylate copolymer is from about 5 to about 30% by weight. 33. The fiber of claim 32, wherein the amount of said alkyl acrylate in said ethylene/alkyl acrylate copolymer is from about 10 to about 25% by weight. 34. The fiber of any one of claims 31 to 33, wherein the alkyl acrylate is selected from the group consisting of methyl acrylate, ethyl acrylate and butyl acrylate. 35. The fiber of claim 34, wherein the alkyl acrylate is methyl acrylate. 36. The fiber of any one of claims 31 to 35, wherein the amount of component (b) is 2 to 10% by weight. 37. The fiber of any one of claims 31 to 36, wherein the composition further comprises: (c) 0.01 to 15% by weight of at least one additional component selected from fillers, matting agents, UV stabilizers, pigments and other additives. 38. The fiber of claim 37, wherein said component (c) is present in an amount of 0.1 to 5% by weight. 39. The fiber of any one of claims 31 to 38, wherein the composition comprises a tubular reactor produced ethylene/alkyl acrylate copolymer. 40. A nonwoven textile made from the melt-spun fibers of any one of claims 31 to 38.