CA2279217A1 - Polypropylene copolymer alloys and process for making - Google Patents

Abstract

The present invention relates to polypropylene alloys which are especially suited for soft fiber and fabric applications. An embodiment of these alloys comprises an ethylene-propylene random copolymer having an ethylene content of from 1.0 to 5.0 % by weight, in an amount of from 40 to 90 % by weight of the alloy; and an ethylene-propylene bipolymer having an ethylene content of from 10 to 30 % by weight, in an amount of from 10 to 60 % by weight of the alloy. The present invention further relates to a hybrid process for making these alloys.

Description

WO 98/39384 PCT/US9$/0428T

POLYRPOPYLENE COPOLYMER ALLOYS AND PROCESS FOR
MAKING

The present invention generally relates to polypropylene copolymer alloys, which are specially suited for soft fiber and fabric applications and a method for their production. An embodiment of the present invention) relates to ethylene-propylene copolymer alloys) comprising an ethylene-propylene random copolymer having an ethylene content of 3.5% by weight in an amount of from 40 to 90% by to weight of the alloy; and an ethylene-propylene bipolymer in an amount of from 10 to 60% by weight of the alloy, said bipolymer having an effective ethylene content that renders said bipoiymer miscible with said random copolymer.

Polypropylene is a well known article of commerce) and is utilized in a wide t 5 variety of applications which are well known to those of ordinary skill in the art.
Polypropylene is utilized widely in many fiber) fabric) or similar product applications. However) it is generally deficient in applications that require high softness such as nonwoven fabrics for disposable garments and diapers. For such soft-end use fiber and fabric applications macromolecules with a statistical 2o placement of propylene and ethylene monomer units (hereinafter random copolymers) have come into use since they can be processed into fibers and fabrics that exhibit improved softness and drape charauaistics in comparison to fibers and fabrics made from homopolymer polypropylene Random copolymers are made by adding small amounts of ethylene in the 25 reacting medium comprising propylene and a catalyst that is capable of randomly . incorporating the ethylene monomer into the macromolecule chain, to thereby reduce the overall crystallinity and rigidity of the macromolecule. Random copolymers, because of their lower crystallinity and rigidity) are preferred over homopolymer polypropylene in fiber and fabric applications that require enhanced 3o softness. However, a number of practical limitations have limited the application of random copolymers in soft-end fiber and fabric uses. One limitation has been the inability of polypropylene manufacturers to economically incorporate ethylene at levels generally above 5 % by weight of the random copolymer. Another limitation has been the inability of existing fiber and fabric processes to economically draw fine diameter fibers and good coverage fabrics from conventional high ethylene content random copolymers and in particular random copolymers having an ethylene content greater than 3% by weight. Coverage is defined as weight of polymer per unit area of the fabric. It is often the most important fabric parameter) since it is related to the yield and) thus the area cost.
These and other limitations will become apparent from the following discussion of a typical spunbond process.
Random copolymers have long been used in the making of nonwoven spunbonded fabrics. In a typical spunbond process a random copolymer resin in granular or pellet form is first fed into an extruder) wherein the resin simultaneously is melted and forced through the system by a heating melting screw.
At the end of the screw) a spinning pump meters the melted polymer through a filter to a die (hereinafter the spinneret) having a multitude of holes (hereinafter capillaries) where the melted polymer is extruded under pressure through the capillaries into fibers. The fibers exiting the spinneret are being solidified and drawn into finer diameter fibers by high speed air jets. The solidified fibers are laid 2o randomly on a moving belt to form a random fibrous) mesh-like structure known in the art as a fiber web. For optimum softness and drape characteristics) solidification of the fibers must occur before the fibers come into contact) in order to prevent the fibers form sticking together. This phenomenon) of the fibers sticking together) ultimately results in a more rigid and less soft fabric.
After web formation, the web is then bonded to achieve its final strength by pressing it between two heated steel rolls (hereinafter the thermobond calender). -The ethylene content of the random copolymer that is used to make the fibers is one of the parameters that affect the softness feel and drape characteristics of the spunbonded fabric. It has long been recognized that softer spunbonded 3o fabrics could be produced by raising the amount of ethylene content in the random copolymer. Generally the greater the ethylene content of the copolymer is, the less rigid and the more elastic each fiber becomes, thus imparting a softer feel characteristic to the fabric itself. However, fibers made from random copolymers having increasingly higher ethylene content take longer to solidify with the result that they tend to stick together forming coarser fibers before solidification occurs.
The result of this phenomenon is, inter ells, that the fabric's uniformity, coverage (basis weight per unit area) and drapelhandle characteristics suffer. The fabric becomes more rigid and less soft. Although, this problem could perhaps be somewhat alleviated by lowering the throughput rate, to allow more time for these resins to solidify before they come into contact, it generally becomes uneconomical to to process random copolymers having an ethylene content greater than 3.5%
by weight of the total polymer, because of the generally very low throughput rate required to prevent the fibers from sticking together.
Moreover, random copolymers having an ethylene content greater than 5%
by weight have not generally been feasible to be produced in liquid reactor or t 5 hybrid reactor technologies. The term "liquid reactor technology" as used herein encompasses slurry polymerization processes wherein polymerization is conducted in inert hydrocarbon solvents and bulk polymerization processes wherein polymerization is conducted in liquefied propylene. The term "hybrid reactor technology" as used herein refers to polymerization processes comprising one or 2o more liquid reactor systems followed by one or more gas phase reactors.
Liquid only and hybrid reactor systems account for the most part of polypropylene manufacturing capacity worldwide In a liquid reactor system) the liquid hydrocarbon solubilizes the atactic portion of the polymer, the levd of which is enhanced by the high incidence of ethylene monomer in the polymer chain. The 25 atactic material is tacky and creates flowability problems in the downstream equipment as soon as the liquid hydrocarbon is vaporized. Because of this phenomenon, ethylene incorporation in the random copolymer is limited to a maximum of 5% by weight) in a liquid reactor system. Above that level) tacky copolymer granules would agglomerate and/or stick to the metal walls of the 3o process equipment generally resulting in the clogging thereof.

Processes employing hybrid reactor technology have been widely used in the production of thermoplastic olefin resins (hereinafter TPO), but generally not in the production of random copolymers. A typical TPO resin, as per US Pat. Nos.
3,806,558, 4,143,099 and 5,023,300, comprises a first homopolymer or random copolymer component and a second rubber-like component known as an olefin copolymer elastomer. Generally, it has been a widely held belief, among persons skilled in the TPO art) that lowering the ethylene content of the elastomer component below 30 to 40% by weight range would result in severe fouling and shutdown of the gas phase reactor. Thus) conventional, TPO resins albeit of a high 1o ethylene content are generally not suitable for typical random copolymer applications such as fiber making) since the elastomer component of a TPO
resin contains large amount of ethylene that renders it immiscible with the homopolymer or random copolymer portion.
Therefore) it has been highly desirable to develop a polypropylene based t 5 resin having high ethylene content which would allow the making of softer fibers and fabrics without the processing and physical drawbacks of conventional high ethylene random copolymers and TPO resins.
SUMMARY OF TAE INVENTION
We have discovered polymer alloys that overcome the aforementioned 2o problems. The alloys in their overall concept comprise two polyolefinic polymeric components that though distinct) are miscable with one another. The team "miscible" as used herein means that the invention copolymers show a substantially single glass transition temperature (hereinafter Tg) peak when subjected to Dynamic Mechanical Thermal Analysis (hereinafter DMTA). A single Tg peak is 25 exemplified in figure 3 and it is to be contrasted with a dual or mufti-hump curvature such as shown in figure 2. Each component can be a copolymer of (having two monomers), or a terpolymer of (having three monomers) or a multipolymer of (having multiple monomers), propylene with any of a number of comonomers selected from the group comprising C3-C20 alpha-olefins and/or C3 3o C20 polyenes.

1) G U L J J V i V . L V G 1\ p 1 1 C L . W 1 1 ~/ C 1 1 1 T V V L vJ V I T V
i (..' . T

97Ep13.PCf Replscemeat Page An embodiment of the presort invetuion, relates to ate ethylene-propylene copolymer alloy which is particularly suited, inter alts, far the peaking of fibers and norewovea spuabonded fabrics having exceptional soSness at economically acceptable processing conditions. Such soflacss will be especially useful in diapers and disposable garments The term "copolymer alloy° as used herein refers to a copolymer comprising two or more polymeric wmpontats, wherein each polymeric comparncat being a copolymer of propylene vrith tthylcnc or other alpha olefins and having a distinct ethylene composition. The copolymer components coin be made eirthar sepazstely and there u~ixed into a single copolymer alloy using a coteve:nional mi~g technique or produced in a sequential stage polymaizadan scheme an embodiment of which is described below. Although, the invention is primsr~y descrined in terms of eths leno-propylene copolymez alloy embodiments it is to be emderstood that the same inventive couccpt may be ~rloycd is vrd,rr to givduce prvpylaae copolymer 13 alloys with other alpha olefins such s~s for instance 1-butane. Also terpolymer butane-ethyleno-propyleae alloys ue wrtb;n the scope of the present invention.
In an embodiment of the invention the copolymer alloy comprises a fast ethyleno-propyleae copolymer said copolymer being a random copolymer ltaviag inn ethylaale coateat of lrom 1.0 to 5_0% by weight, m as sasount of fi~om 40 to 90% by weight of the alloy, sad a second ethylene-propylene copolymer hsving an ethylene contain of firorte 8 to 40% by weight, in as smouat of from 14 to tSOYo by weight of the alloy. The ethyleno-propylcac copolymer alloy is further characterized in that the two copolymer componcats the. alloy arc miscible with acne another. In ~nu~ast, ThO resins denoonstrate at least two Tg peaks. The later Tl'O resins generally cannot be drawn into fibers.
AMENDED SHEET

[y.. 1 . . \ / . , l .I . 1 - 11. L.. \L v 11 .. . ~ , ~ ~V - - vJ.i ~ L n _ .
t v . ...t.~l m... ~tlv ~..n t a n 1'CAJ LV VV a V. ~uo~ I'm a~ 'CA 022L7921L7L 1999-07-27~ TuV:'eI~'u 1 Tun ~~p.~sr 97H013.PCI' ILeplscemeat Page -d Another embodiment of the presort invention, relates to a muki~reactor process for producing the invention copolymers. A particular embodiment of this pmcess comprises: a first stage of polymeriz~ag a miadure of tthylene and propylene is single or phual reactors, is the presence of a catalyst s~~stem capable of randomly incorponaing the ethylene monomer into the macromolecules to form a raadonn copolymer having an ethylene conxeat of from 1 to 5% by w~ghi in an au~ouut of fcmn 40 to 90% by weiglit of the alloy; and a xcond stage of then, in the fursher presence of the random copolymer containing active catalyst polymerizing a mi.~we of ethylene and pmpylene in single stage or it< plural I0~ stages to form as ethylene-propylene copolymer having an ethylene content of from 5 to 4090 by weight, in an amount of from 10 to 60% by weight of the alloy.
A particular embodiment of the invention re4rec to a hybrid p~cR having a 8r:~t poiymtrization stage camprisiag of single or phuat liquid reactors and a second polymexfratian stage comprising of single or phual gas phase rectors. Oehcr embodiments of the present invemioa further relate to Sbers and fabric articles made of the invention copolymer alloy and to methods of making these articles.
B~irf Deacr;~tion of the Drawings 3hese and other features, aspects) and advantages of the present invention will beconu helter understood with regard to the following drs'criptioa, appended claims, and accatnpanying drawings where:
higure 1, is a diagram of a hybrid two reactor process emboditste:et of the present invention.
Figure 2, a a l)MTA analysis of a convent'sonal reader IPO resin.
Figure 3) is a DMTA analysis of as anhodimenc of the prese~ut zuvemion ZS copolymer.
Figure 4, is a Trm~smisaion Eloctran Miorosoopy imago of a cross cut of n fiber prepared with an embodiment of the present invention copolymer.
Figure 5, shows the abetting point, as measured by Differential Scanning Calorimeter (;3SC) analysis, of an embodiment of the presort invention copolymer.
AMENDED SHEET

-7_ Figure 6, shows the softness as a function of the bonding temperature of a non woven spunbonded fabric made from an embodiment of the present invention copolymer.
Figure 7, shows the tenacity and elongation properties of fibers made using an embodiment of the present invention copolymer.
DetAiled Description of the lnvention While the invention will be described in connection with preferred embodiments, it will be understood that it is not intended to limit the invention to those embodiments. On the contrary) it is intended to cover all alternatives) 1o modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.
Alloy Compositions Conolymer AIItL~
An embodiment of the invention broadly relates to a polymer alloy which is ~ 5 especially suited for soft-end use applications. The term polymer alloy as used herein refers to a polymer comprising two distinct but miscible polyolefinic multipolymers of propylene with at least one alpha-olefin and/or polyene.
Generally, the alpha-olefins suitable for use in the invention include ethylene and those that contain in the range of 2 to 20 carbon atoms, preferably in the range of 3 2o to 16 carbon atoms) most preferably in the range of 3 to 8 carbon atoms.
Illustrative non-limiting examples of such alpha olefins are ethylene) 1-butene) 1-penter~e) 4-methyl-1-pentene) 1-hexene) 1-oetene, 1-dccene, 1-dodecene and the like. In one embodiment) the polyene is a diene, that has in the range of 3 to carbon atoms. Preferably) the diene is a straight chain) branched chain or cyclic 25 hydrocarbon diene having from 4 to 20 carbon atoms) preferably from 4 to 15 carbon atoms) and more preferably in the range of 6 to 15 carbon atoms.
Examples of suitable dienes are straight chain acyclic dienes such as: 1,3-butadiene) 1,4-hexadiene and 1,6-octadiene; branched chain acyclic dienes such as: 5-methyl-1,4-hexadiene, 3, 7-dimethyl-1, 6-octadiene, 3, 7-dimethyl-and dihydrooinene;
single 3o ring alicyclic dienes such as: 1,3-cyclopentadiene, 1,4-cyclohexadiene, 1,5-cyclooctadiene and 1,5-cyclododecadiene; and multiring alicyclic fused and bridged _g_ ring dienes such as: tetrahydroindene, methyl tetrahydroindene, dicyclopentadiene, bicyclo-(2,2,1 )-hepta-2-5-diene; alkenyl, alkylidene, cycloalkenyl and cycloalkylidene norbornenes such as 5-methylene-2-norbornene, 5-propenyl-2-norbornene 5-isopropylidene-2-norbornene, 5-(4-cyclopentenyl)-2-norbonnene, 5-s cyclohexylidene-2-nrbornene, 5-vinyl-2-norbornene and norbornene.
Particularly preferred dienes are 1,4-hexadiene, 5-ethylidene-2-norbornene) 5-vinylidene-2-norbornene, 5-methyl-2-norbornene, and dicyclopentadiene. Especially preferred dimes are S-ethylidene-2-norbornene and 1,4-hexadiene.
A particular embodiment relates to an ethylene-propylene copolymer alloy 1o comprising a first ethylene-propylene copolymer said first copolymer being a random copolymer and a second ethylene-propylene copolymer) wherein the ethylene content of the second copolymer is lower than a critical value to impart miscibility between the two copolymers. For sake of clarity, the second ethylene-propylene copolymer will be referred hereinafter as "bipolymer" to distinguish it ~s from the first copolymer component. We have discovered that if the ethylene content of the bipolymer is kept below 40% by weight, then the copolymer alloy of this bipolymer wish a random copolymer has a substantially single Tg peak and more importantly allows the making of fibers and fabrics having exceptional softness, generally without the processability problems associated with high in 2o ethylene random copolymers, or TPO resins. The relative amounts of the two components in the alloy may vary. The random copolymer component of the alloy may have an ethylene content of from 0.1 to 6.0% by weight) but preferably should be kept within the range of from 1 to 5 % by weight and most preferably of from 3 to 4 % by weight. lts molecular weight and molecular weight distribution may vary 25 within a wide range.
Generally) the ethylene content of the bipolymer component may vary from above 6 to 40 % by weight. The exact upper limit of the ethylene content in the bipolymer will be defined as the point at which the bipolymer ceases to be miscible with the random copolymer component. It is understood that at ethylene levels of 30 5 % by weight and or lower the bipolymer is in effect a random copolymer.
Blends of random copolymers having varying ethylene composition up to 5% by weight are well known in the art and are outside the scope of the invention copolymer alloy. Ethylene-propylene copolymers having an ethylene content of from 6 to by weight are also often times referred to as random copolymers, however, they begin to exhibit increased levels of blocky, crystalline ethylene. It is preferred, for s purposes of the present invention, that the ethylene content of the bipolymer be kept within the range of from 10 to 30% by weight of the bipolymer. For optimum results the ethylene content of the bipolymer should be kept within the range of from 10 to 20% by weight of the bipolymer.
There are a number of structural variables which affect the ultimate to properties of the alloy. These structural variables are important in the sense that they can define the exact ultimate properties of the alloy and may be tailored to meet the requirements of a particular application. Two of the most important are the overall ethylene content and molecular weight of the copolymer alloy. The overall ethylene content of the alloy is the primary factor determining the softness t s of the various articles made from the alloy and msy vary within a wide range from 3.5% to 30% depending upon the required softness for the particular end-use.
For fiber applications the overall ethylene content is preferably from 5% to 15 %
and most preferably from 6 to 8% by weight of the alloy. The molecular weight (MV1~
of the copolymer alloy determines its melt viscosity and ultimate desirable physical ~o properties. The MW of the alloy as determined by the MFR test (ASTM D I
238, Condition L) may vary within a wide range from fractional to 1000 g/10 minutes, preferably between 3 to 100 g/10 mirnrta and most preferably between 25 to 65 g/ 10 minuta Another important structural variable the molecular weight distribution (MWD) of the alloy may also vary within a wide range) but a generally is narrow overall MWD is preferred for fiber applications. MWD plays a role in melt processability as well as the level and balance of physical properties achievable.
The MWD may vary from extremely narrow (as in a polydispersity, Mw/Mn, of 2, obtained using metallocene catalysts), to broad (as in a polydispersity of 12). A
polydispersity in the range of from 2 to 6 is preferred and a polydispersity in the 3o range of from 2 to 4 is most preferred. Another variable, the composition distribution refers to the distribution of cornonomer between the alloy's molecules.

The overall structural variables of the alloy depend upon the structural variables of each of the alloy components and the weight of each of the components in the alloy.
The random copolymer component may have an ethylene content of from fractional to 5% by weight, a MFR of from fractional to 1000 g/10 minutes, a composition distribution ranging from very narrow (as in the case of metallocene made random copolymers wherein almost every molecule has almost the same content of ethylene comonomer) to broad (as in the case of typical Ziegler-Natta catalyst systems)) a MWD of from very narrow (polydispersity of 2 as in the case to of metallocene made random copolymers) to broad (polydispersity of from 3 to 8 as in the case of Ziegler-Natta catalyst systems) to extremely broad (polydispersity of from 8 to 50). The above structural variables of the random copolymer may be controlled with a number of well known in the art methods including catalyst selection andlor use of multiple reactors in series.
t5 The bipolymer component may have an ethylene content of from 6% to 40% by weight) a MFR of from fractional to 1000 g/ 10 minutes, a composition distribution ranging from very narrow (as would be the case with metallocene made bipolymers wherein each molecule has almost the exact same ethylene content) to broad (as in the case of typical Ziegler-Natta catalyst systems)) a MWD
20 of from very narrow (polydispersity of 2 as in the case of metallocene made random copolymers) to broad (polydispersity of from 3 to 8 as in the case of Ziegler-Natta catalyst systems) to extremely broad (polydispersity of from 8 to 50).
'The above structural variables of the random copolymer may be controlled with a number of well known in the art methods including catalyst selection and/or use of 25 multiple reactors in series. The ethylene content of the bipolymer should preferably be from 10 to 30 % by weight and most preferably from 10 to 20 % by weight.
The ethylene content of the bipolymer is critical in insuring the miscibility of the two components which in turn renders the alloy suitable for applications such as fiber spinning, where resins hitherto existing present processing problems because 30 of their immiscible, two phase regime. Also, the ratio of the bipolymer MFR
over the random copolymer MFR may vary within a wide range but should preferably be maintained within the range of from 0.1 to 10, and most preferably of from 0.5 to 5Ø
A particular embodiment of the invention alloy comprises an ethylene-propylene random copolymer having an ethylene content of from 1.0 to 5.0% by weight, in an amount of from 60 to 80% by weight of the alloy; and an ethylene-propylene bipolymer having an ethylene content of from 10 to 40 % by weight) in an amount of from 20 to 40% by weight of the alloy. An ethylene-propylene copolymer alloy comprising an ethylene-propylene random copolymer having an ethylene content of from 2.0 to 4.0% by weight, in an amount of from 60 to 80%
to by weight of the alloy; and an ethylene-propylene bipolymer having an ethylene content of from 10 to 25 % by weight) in an amount of from 20 to 40% by weight of the alloy) is a preferred embodiment. An ethylene-propylene copolymer alloy comprising an ethylene-propylene random copolymer having an ethylene content of from 2.5 to 3.5% by weight) in an amount of from 65 to 75% by of the alloy;
and an ethylene-propylene bipolymer having an ethylene content of from 10 to 20 %
by weight) in an amount of from 25 to 35% by weight of the alloy) is the most preferred embodiment.
These ethylene-propylene copolymer alloy embodiments are further characterized in that the random copolymer and bipolymer components are 2o essentially miscible with one another) as exemplified by the substantially single Tg peak obtained by DMTA analysis (Figure 3 }. The DMTA on the injection molded sunples were run on Polymer Laboratories Mark II instrument Samples were run in uniaxial extension configuratron from -100 to 160°C at a heating rate of 2°C/minute and at 1 or 10 Hz frequency. The data plotted were analyzed for storage, loss modulus and tan delta. These alloys are processed into fiber and nonwoven fabric articles having excellent softness) under generally improved processing conditions as described more in detail below.
In contrast, conventional TPO resins consisting of greater than 40 % by weight ethylene in the bipolymer cannot generally be spun into very soft fiber or 3o fabric articles. For instance, the DMTA analysis of a typical TPO resin produced according to the teachings of US Pat. No. 5,023,300, shows the immiscible nature 1\l.v r... .n \t..r . ,.. ._ _ (JV ~vv.y . v,a .~
1 f C V ' ~ L V , V y'... y V yL V O 1 \ O i ~ ~ y C L L 1 1 V C 1 y ri 'T ~V
V ~ ~L ~ V V f T V ~y r ~ ~ ...

97H013.PCT
Replacemeat Psge (two well disccrn.iibic Tg peaks) of its random copolymer and rubber cony~onenss.
(See F':$ure 2), This resin, consisting of a random copolymer hnvving as ethylcac content of 3% by weight and s bipolymer caa~onent having an ethylene content of 35% by weight, ~chibits two disslnct gloss transition temperntures»one Tg m 0°C and one Tg at -SO°C--which are i~adicxtive of the immisc~'b~rty of the two co~onents.
AMENDED SHEET

11.1 v v:.v ~ n..n .a-.ma. a. ,... .. ,. . ~ , -...u ~ . . ~ . . . .... ~.~., a v a- ~ ~r.u m.n ~mno~r~r~u.
nou .u .ru 'iu'.'~ r~°~ '~°'''~ CA 02279217,11999-07-27 , Tuu, ~'~u r-ray:.."r ' 97H013.PCf Replacement Page Procwa for Mskin~-the Invention Allovs A second object of the inveatio~, relates to s process for producntg these etbyleao- propylene copolymer alloys An embodiment of the process invention co~zipriscs: I) a first step ofpotyme:iang a of ethyleae and propylene is ~l4lE~lGED SNEE i lvs.l. '.m.'.~a a \\Ilt-.W11.. a ;~J ._v ~ -.J;J . 1. -m , ov.. mu n~av~1-~
r~tJ m.i _<u<..m a . .
- ~ 'cu 'v uu i a ~ r,o oral i ~ ~A 02279217 1999-07-27 Tun ~'"v ~'T" i ~h% .
~ca '~
97H013.hCT
Replacement Psgt singly or plural reactors in the preseaice of a catalyst to form an ethyleno-propyltrte randout copolymer having as athyle~ne content of from 1 to 5 % by weight in an amount of from 40 to 9n°.6 by weight of the alloy; and 2) a second step, in the further presence of catalyst containing random copolymer, polymsri~iu8 a mi~b~re of ethylene and propylene in sia8le or in plural reactors to form an ethyleno-propylene bipolymer having as ethylene contort of from 6 to 409'o by weight) in as amouar of &on: 10 to 6096 by w~oight of the alloy. In a particular embodiment of this pmcess, the first polymerization step is conducxcd in a p~~ Ic~op _r-actor end t5~t second polymerixadon step is conducted in a gas i 0 phase reactor. In another ernbodimeut of this invention bipolymer can be incorporated first.
The invention embodiments of. Table l , are made in a tx~n-stage mnki-reactnr process, ooa~risyng a first stage having two s~nrod tank auto-refiigesated bulk liquid reactors in series operation and a sxcnd sage corapriaing s siaglo gas phase W idized bed reactor. A propyizuo auto-r~rlgerated reactor operates at the liquid vapor equilibrium of propylene. The heat of polymerization is primart~y removed by the vagorization~ surd subsequent condensation of propylene. A
small, 5.5°C (10°F) temperature di~'erential is maintained the first and second reactors. ~thylcac and hydrogen oonoentratians iu Beech reactor are controlled to abcaia the desired ethylene incorporation and 11~R. Reactor pressure floats with the Teactar temperature and the ethylene sad hydrogen concentration, in the vapor space of the reactor.
The alloys utilizod in the present invention may'~l~e made by say ~
catalyst which allows for pmper cormol of the above mentioned structtual chancteristica !One possa'ble me:bvd is through the use of highly active olefin goiym~rtion catalysts kuawn as Zicgler'Natta catalysts. Cataly9ts of the Ziegle~Natia type, i. e., catahysts co~risin,g titanium halides supported on an inert carrier etch as magnesium chloride, orguaoahuninum coa~outtds and elegy donor compounds, are well known and are d~bed is US patent non 4,i 15,319, 4,98,548, 4,657,883. Also lerowst is incorporating an electron damor ~onnd into the titanium-containasg component. Art olefin polymtrizatbon typi~uy ~omp~ a solia AMENDED SHEET

~~°' L c' CA 02279217] 1999-07-27 ~v~ °'"V 1 TV L' ~y .:. ,,) ' 9TEal 3.PCT
- Replacement Page titanium contaiaimg compotmd, an alkyialuminum compolmd Jmowa in the art as a cocntalyst and an electron donor external modifier compo~md. 3 be cxtcmaI
electron donor is distinct from the elec:xon donor which may be incorporated with the titanium containing solid compound.
Illu~sdve examples of T.aepler-Natta type solid catalyst camponeats~
include magnesium-containing, trtaninm compounds such as those commercially known with the trade name F?4S and HMG101 and whivh are supplied by ~nomt Inc. Anothex possible catalyst compoaem of use is this invention is the TK catalyst contponeut, a proprietary titanium halide-based magnesium dtloride-containing catalyst coa~oaea: produced cotnnaarcially by AKZO Chemicals Inc.
Another possible, catalyst con~oneat is described in US Pat No. 4,540,b79. It is to be ~muletstood that Fhe these posmble solid components listed about are illustrative and that the present invention is in no way limited to any speci~c ~PP~ ~~-N~ tYPe catalyst or camlys~ cod.
The chemicals methyl-cycIohexyldimethoxy silane (MCMS) and tri-eshyl-ah~intun (VEAL) may be used as external electron donflr and cocatalyst, respectively, both during prepolymerixation and main polymerization at typical concentrations. The cuncentr~ioa of MCMS may vary from 10 to 100 is weight ppm per total Propylene feed in the lead reactor. At s conceabratioa lower tluan I O
weight ppm the polymer may become tacky while at a con~tion granter than 100 the overall catalyst e~ciency is siguificaatty reduced A concentration of MCMS from 30 to 60 weight ppm is preferred for ogti~m results. Many other elecsroa donors ar mixtures thereof may be 'uWized. facampics of suitable elecpro~n compounds include aliphatic and aromatic silanes such as the ones descn'bed in Ug Pat. Nos. 4,540,579, 4,420, 594, 4,525,35) 1,565,798 and 4,829,038.
TEtt.L concentration can vary $rom 50 to 400 weight ppm per total progyieno feed in tfie lead resetar. At coneemsrittians less than 50 ppm the catalyst ega~ncy suffers while at cancentrstioas greater than 400 peat the effect of TEAL is insignificant. A coaceatratioa of TEAL of ~rota 80 to 150 is preferred for aptiaxtm results. Mmy other a>Icylslumitium cont>pottads or mixtures thereof may AMENDED SNLtT

nw .,w~.~. t:n.t -an.L.,wu:.~ ,1., ' "''' -CA 0~2279217~ 1.999-07-27r"., _,.~«
(n:m- .r.t.a ts;~ ~s.<<,~.~.-tt~~ ~%i~u I CM LV ~JJ lV.LIC 1\DI iC TVV LVV ITV1 9T~013.PCT
Replst Page also be used as oncatalyst. Additional amounts of donor and cocatalyat can be added in the second stage to inctease the catalyst activity and improve the flowability of the polymer particles. Prepolynnerization is optional and may be performed ehher in a batch process or preferably is continuous process mode.
It is &uther understood that the concept pf ~.his invention should equally be applicable using a num~b~r of over Zieglor-Natta type catalyse systems disc.losod in the art. Possible internal modifiers are descn'bed in US Pat 5,218,052.
Another suitable method is thmugh the use of s class of highly active I0 olefin polymerization catalysts known as metatlocenes. A mesallocene casalysc would be preferred since it manld allow the .production of a copolymer alloy having ar MFIi' is the range offiom 35 to 20nO g/1 t1 mt»ntes with s very narrow M1VD in the reaaar system thus eliminuiag the need Eor post reactor oxidative de~sadati,aon ofthe alloy.
Looking at the simplified Sow diagram of F'ignro 1, Liquid propylene (PR), cthylcac gas (ET), a catalyst (CAT), as argattoa3ami~tum compound (COCAT1), an elearon donor (COCA'T2) and hydrogen (HYD) are fed i~o the lead reactor 11 of the &st Stage 10 to produce the desired ethyleno-propylenc random copolymer having sn ethylene content rangcag from 1 to 5 % by weight. IIydtogea is fed into the first stage reactors) to ~ntrol the melt Bow rate (MfR) of the random copolymer rests. 'The exact amonat of hydrogen needed to obtain a desired MFR
depends on the exact catalyst combination and the ethylene iacatporatioa The ratio of ethylan n to p~py~o .m the fled ~rols he, ethylene content of the random copolymer. Although the process c~oodiiions n~ded for making the 2S .aforementioned random capolytuers are wall known, for the sake of clarity.
the gcnoral typical rangc8 for the invcmion are roo'rted below. Thrse ranges should not be as limiting the scope of the grt;sent inveatian in any way, ~7STAGE REACTOR CONDITIAN~
Cacalysc: F'f.~S fnr examples 1 dt2 and HMC.101 for examples 3-5 ~bonor. MCMS
~MEiVDED Sf~EET

.\\. r. ~.. ~Ir ._ .'. ' ~ - .. . . . ~. ~. . a .... ~r~..a1 f lIl 1 ,. ~ ~v V ~ ~LV~~ VV i Vr.~L l G G ~yC CA ~~~~~~~~y 1999'7'27 TVV~ C~vJV f TV
yr ~,~r~ y y 9T8073.PCT
Replacement Page Alkyl: TEAL
First Reactor temperature, 54.4-71°C (130 -160 F) pressure, 2758-3447 kPa (400-500 psig) lte~dence Time, 0.5.3.0 hrs Hydrogen, 0.1-0.35 mole96 l thyieae, 1.0-Z. 2 utole9'o Second Reactor teu~perature, 4$.8-65.5°C (120-1~0 F) Pressure, 2b20-3309 kl°'a (380~480 prig) Residence Time, 0.5-3.0 hrs Hydrogen, 0.1-rD.33 mole%
Fthylcnc, 1.0-2.2 mole'°~f~
The random copolymer pradnct of the first Stage) is then transferred through s series of monomer disengaging devices, well lmown to those skilled in the art, and the result3mg prodnd is gramulsr form is then fed to a gas phase flaidizod bed resctor 21 for the second Stago 20 processing. ?he gas phase reactor can he any of a number of w~el~known fluidized bed type reacxors disclosed is US Patents 4,543,399; 4,588,790; 3,028,670; 5,382,638; and 3,332,949. Ptvpylene and ahylenc fcd into the gas phase reacxor of the socoad Stage era polymerized is the presence of the adivc catalyst containing random copolymer granules fed from the fast Stage. Hydrogen is also fed in order to regulate tire molecular weight of the bipolymcr i. e. tire copolymer made in said gas phase rector: Additional donor could be ut0ized if required for better powder flowabifrty. Also, s 'ddztianal cocatalyst could he added to sugt»Icnt the Catalyst activity, if needed. The ethylenelpropyleae gas mole ratio (C2 Ratio) in the gas phase reactor should be controlled at or below s crhical val;ra (Cr. v.) iu order to ensure that the bipolymer and random copolymer phases are miscible. The critical value is expected to vary sotnevvhat with the c:t:lyst system and process dons. The ethylenefpmpylene gas mole ratio in the gas phase reactor should be adjasted ZmtO the DMTA saalysis of the copolymer alloy thus noade shows substantisUy o single peak Far tlu psrticulsr etx~bodim~s of Table 1 the critical AME~VDE~ ~~i::E

y . . . .. ~ ..m , .. . . . ~ ...~ ~ . ~ ~ n ". ~ ,u, n .. 1 _ ~ 1 .J ...J
~J:).J1 f tJ:) ~ (i y 1 ~C.H .L\J, ...l.V..~LlO~ IvGI ~1C CA O~L.~L~J9~~LI~J~~1999'~7'2.7 ~ TVvJ~
LVV f'TV1 y 1L
9'TBO13.PG'1' Replacement Page _ I8_ value of the ethyleaelpropyleae gas mole ratio was found to be wound 0.35. A
gas mole ratio in the range of 0.10-0,25 is preferred. A gas mole ratio in the range of 0.15Ø2(3 is most preferred. For the catalyst utilized is the aforementioned examples tile second stage raac;tor oandition ranges ere provided herein, for the sake of clsrisY.
SECOND.SCAGE REACTOR CONDITIONS
Gas 1'haee Reactor tempersaac, 963-1172 kPa (140-170 psi$) Press~u~ 689-1241 kPa ( 100-1$0 psig) Residence Time, 0.2-3.0 hrs E~ykaelPropylenc Gas Mole patio 0. l0-0,3,~
A prsf~ embodiment of the present iuyeutio~ot employs two liquid pipe loop reactors in series in the fire( !asge. Pipe loop readers sre recirculating.
jacketed pipe reactors, similar to those disclosed is U~ Patent numbers 3,437,64E;
3,?32,335; 3,995,097; ~(,068,054; 4,18Z,81o; aced 4,740,530. The pressure is rnaiatainai ~Cientiy high to suppress prapykne vaporization. As an illustrative example, the temipe:ature and presQUre might be set at 71.I°C
(160°F~ anal 3447 kPa (500 prig) respectively. The best of polymezization is removed by a cooling water ~ackrt.
1n, an ombodimeat of the pros~emut savention butuoe mpy bo i~roduced in addition to the propylene and ethylene monomers in both or one of the two stages w pivducx a buteno-etltyleao-pmpyleae atlo3 comprising two components, the 5rst component being a polymer spledod from the group consisting of ethyleno propylene random copolynners; butmo-propylcne random copolymers, and bacene-ethylene-propylene teipoly:~rs, the secamd compaaeut being a polymer selected from the group consisting of ethyleno-propylene random copolymers, bateae-propylene readoni oopolymore, and buteao-etbykao-propyteae terpoIymers, wherein said two oono~oneats are distinct but misciiblc.
F~bara~ Made from the ~rvaation Ca,~dvmer Allova Another object of this invention is flue preparation of fibers made from the copolymer alloys, An ethyleno-pmpylene copolymer prepared as explained above. is then subjected to s ca~rolted theology (CR) process well lmown in the art, AMENDED SHEEP

y o . , ~ ~.n : ~W .. w..., ~.. _ . _ ,~.; . 1 . ~ _. . t..m. a r~tln. _ r~r.J
u:.u ~ n.n.mc~rv~J~ rr I.J
1 L~~ly, i~V VvI i V . L.VG~ .~Ql~l ~ ~CA 02279217 1999-X7'27 '"" ~""' r ~V a f... 1J
97Bb13.PCT
- lteplacemeat Page ~ 19~
wbcreby the copolymer is visbrokea into a resin having a narrower molxvlar weight distribution and lower average molecular weight in order to taeilitate h'ber spinning. The molecular weight (MVO of the visbroken copolymer alloy determines the level of melt viscosity sad the ultimate desirable physical properties of the fiber. The MW of the visbroketl alloy as determined by the MFIt test (ASTM D1238, Condition Ly may vary within a wide range 6rom frscrianal to 1000 g/10 m'raufes, preferably b3 to 100 and most preferably betw~ecn 25 to 65. The MWD of the visbrnkea alloy may also vary within a wide range, but a generally naaow overall MWD is preferred for fiber applications. MV~D plays a 1 a role in melt processability a s well as the level and balance of physical prapecties achievable. The IdWD of the visbmkea alloy may vary from extremely narrow (as is a polydispct'sity, MwlMn, of 2~ to broad (ae in a polydispcrshyr of 12). A
polydispersity na the range of fiom 2 to 6 is preferred anrl a polydispersity in tho range of from 2 to 4 is most preferred. The C'lt process msy also convert the polymer granules to pellets for easier feedang into the fiber spinning extcttder.
Additives such as stabilizes, Pigan~ts, fi3le~ autioJddants, ultra-viold screening agents, nucleating agents, ccttam processing oils and the flee may optio~tally be added; however, this should not be coasidecod s limitation of the present invention. CR pmcexaec are descn'bed m U. S. Pat. Na 4) I 43,A~.
The copolymer alloy is then d.-awn to a fine diameter fiber by one of ~vecsl wall lmown in the art modifications of the basic rne3c-cxtrusiaa fiber process. This process consists of the steps of ( 1 ) cammtiously feeding the copolymer alloy to a making screw extruder; (Z) snm~Gmeously melting and forcing the copolymer alloy through a spinneret whrreby the alloy is e~akcuded into fibers under press<ue through holes that, depending upon the desired fiber product, a,sty v~uy widely is number, size sad s)sslsr; (3) solidifying the fibers by transferring the heat to a srurouadiag nudium; and (4) winding of the solidified fbers onto padutges. F~hor pracessing typically iacyndes orienting the $bers by drawing it to many tinier its original length. Also, a variety of thermal and ttxzux~g atatmarts will Imowa in tho art may be etnplayed, depending on the desired final properties of the AMENDED SHEET

w~.~~u.~~..V ...iV~~~LVO' 1\01~1C 1~J~~ ~ u~w .. TVV~L~VV 't'w CA 02279217 1999-07-27 ~"" ~' 'T
y7H013.PGT
Replacement Page fiber. Embodiments of the presort invantivn copolymer alloy are drawn into f"me diameter fibers at generally ltigb draw down spetd, without the individual Sbers sticking together below the crystallization paint.
Although the terms of "dravwdown speed" and "crystallization point" are well lmown among those skilled is the aft, a brief explanation is provided herein in the interest of clarity. The dravwdown speed is measured by extruding the polymer through a capillary at s given rate throughout, typically 0.3-1.2 glbole>Fmda. The take up speed of the ~r is increased wail the fibezs break The maximum take up speed at which the bber breaks is defined as the draw down IO speed. For effective spinning in a spunbond process, a resin should have st least 1,000 nleter/minutes of draw-down speed capab'iInty. Hotnapolymer add conventional random copolymer resins used in spuabond appliratioas are processed at a draw.dovvn speed of from 1,000 to 5,000 trreters per minute.
TPfJ
rcsias arc gararally not ascd is fibs:r spinalag because of their poor pnoocasiag characteristics. Also, fibers made from TPO resins would be stiff and result in low coverage nanvvoveu fibrics as it is explained below. The draw down capabilisy of such a resin would be less than 1,000 meters per minute.
'The c~aIlizxtion poiru is the point st socaa distance below the spinneret where the fibers solidify. Fibers made $om the resin of the present invention crystallize faster than correspa~ng conventional random capotymG'rs i.c.
random c~npolymers having the same ethylene co~cnt. This charadtriatic is combaLation of their overall high dhyleae conttat results in the making of fabrics having exceptiooat balance of soi~ess, ~inniag capabifrty, and physical properties.
Fibers prepared tom embodiments of the present invention copolymer alloy exhibit exc>cllcat characteristics (see figurt 7). Tstrength is comparable to that of polypmpylefle. Moreover the fiber iR more tlexibk and fools icnfler.
S~a~nbondad Fabrics tram lnventioaa C mer ~,lIovs A paraicular embodiment of the prcscat inve>rdan mvvlves the uaaG of the invention copolymer alloys in the malting of spunbonded fabrics. Conventional spuabond proixsxs are illostratal in U. S. Patonts 3,825,379; 4,813,864;
4,405,297; 4,208,366; and 4,334,340.
A~1E~ JDE~ SNEE i purposes of US patent practice. The spunbonding process is one which is well known in the art of fabric production. Generally, continuous fibers are extruded, laid on an endless belt, and then bonded to each other, and often times to a second layer such as a melt blown layer, often by a heated calendar roll, or addition of a binder. An overview of spunbonding may be obtained from L. C. Wadsworth and B. C. Goswami, Nonwoven Fabrics: "Spunbonded and Melt Blown Processes"
proceedings Eight Annual Nonwovens Workshop, July 30 - August 3) 1990, sponsored by TANDEC, University of Tennessee, Knoxville) TN
A typical spunbond process consists of a continuous filament extrusion, to followed by drawing) web formation by the use of some type of ejector) and bonding of the web. First) the invention ethylene-propylene copolymer alloy is visbroken using peroxide into a resin having a narrower molecular weight distribution and 3 5 MFR. During this step the polymer granules are converted into pellets. The pelletized 35 MFR ethylene-propylene copolymer resin is then fed into ~ 5 an extruder. In the extruder, the pellets simultaneously are melted and forced through the system by a heating melting screw. At the end of the screw) a spinning pump meters the melted polymer through a filter to a spinneret where the melted polymer is extruded under pressure through capillaries) at a rate of 0.3-1.0 grams per hole per minute. The spinneret contains a few hundred capillaries) measuring 20 0.4-0.6 mm in diameter. The polymer is melted at 30°C-50°C
above its melting point to achieve sufficiently low melt viscosity for extrusion. The fibers exiting the spinneret are quenched and drawn into fine fibers measuring 10-40 microns in diameter by cold) 1000-6000 m/minutes velocity air jets. The solidified fibs is laid randomly on a moving belt to form a random netlike structure known in the art as 25 web. After web formation the web is bonded to achieve its final strength using a heated textile calendar known in the art as thermobond calendar. The calendar consists of two heated steel rolls; one roll is plain ant the other bears a pattern of raised points. The web is conveyed to the calendar wherein a fabric is formed by pressing the web between the rolls at a a bonding temperature of 130°C-150°C.
3o While bonding occurs within a wide temperature range the bonding temperature must be optimized for achieving a fabric having maximum mechanical strength. Overbonding, that is, bonding at a temperature greater than optimum results in fibers having significantly weaker fiber around the bonding point because of excessive melting of the fiber. These become the weak points in the fabric.
Underbonding) that is, bonding at a temperature lower than the optimum results in s insufficient bonding at the fiber-to-fiber links. The optimum bonding temperature depends upon the nature of the material that the fibers are made of.
Spunbond fabrics produced using the ethylene-propylene copolymer alloys of the present invention exhibit a surprisingly good balance of softness and mechanical strength. Moreover, their optimum bonding temperature is lower than ~o that of conventional random copolymers, thus permitting less expensive processing. (See Figure 6). Note that all copolymers were melt spun at the same low draw-down speed in order to allow for a. meaningful comparison.
Softness or "hand" as it is known in the art was measured using the Thwing-Albert Handle-O-Meter (Model 211-10-B/AERGLA). The quality of i 5 "hand" is considered to be the combination of resistance due to the surface friction and flexibility of a fabric material. The Handle-O-Meter measures the above two factors using an LVDT (Linear Variable )r~ifferential Transformer) to detect the resistance that a blade encounters when forcing a specimen of material into a slot of parallel edges. A 3-I/2 digit digital voltmeter (DVM) indicates the resistance 2o directly in grams. The "hand" of any given aheet of material is the average of four readings taken on both sides and both directions of a test sample and is recorded in grams per standard width of sample material.
jExamnles 1-S
Conolvmer Alloys 25 In order to provide a better understanding of the present invention including representative advantages thereof, particular embodiments of the present invention copolymer alloy containing a varying ethylene content in the bipolymer are provided in Table 1 herein. These examples are not in any way intended as a limitation on the scope of the invention.

EXAMPL1:S OF
ETHYLENE-PROPYLENE (:OPOLYMER ALLOYS
f ~
s312, ~;~~i ~ . ~~~, ,::~ .z.,~
RANDOM COPOLYMER ~ ; t'~ u' ~
""t F N' ~t~;
f MFR G/ 10 2. I .0 2. 2. 2.

C2 /0 3.4 3.1 3.3 1.1 3.0 ~~~~
_., '" h~': sf~,3.t~fk', !' BIPf~LY,I~IER ,;t.;y -r'Fii~i~f,' 12.8 25 ~3si9f'~~,:~
C2 in Bi of er wt. % 9.9 ~i3~

BIPOLYMER /0 36 35.8 24 15.6 24 BIPOLYMER MFR (G/10 MIN 10.6 0.75 0.65 1.30 1.0 COPOLYMER ALLOY

MFR (G/10 MIN 4.1 0.9 ~ .7 2.8 1.7 C2 WT% 7.0 7.7 8.3 5.0 8.3 Eaamnles tr7 Bntene-Ethylene-Pronvlene Alloys In order to provide a better undlerstanding of the present invention to including representative advantages thereof) particular embodiments of the present invention terpolymer alloys containing a var)ring ethylene and butene content in the terpolymer component are provided in Tablie 2 herein. The terpolymer alloys of examples 6 and 7 exhibit a single melting point peak which is indicative of the miscible nature of their two components These alloys are expected to show a 1 s single Tg peak and be exceptionally suitable for soft fiber applications.
These examples are not in any way intcndcd as a linutation on the scope of the invention.

WO 98!39384 PCT/US98/04287 EXAMPLES OF
BUTENE-ETHYLENE-PROPYLENE TERPOLYMER ALLOYS
h ~\, ~. QY Bt ~~~~ ~~ ~ ~ ~j,~i~ ~~J.
A ~ ~~~~~q#u ~ ';~i;~:m>:: , FIRST COMPONENT .
~
~

MFR G/ 10 0. 0.4 B~~ % 0.0 3.1 C2 /0 3.5 1.6 .~~E~ ND ~tJMP filF.N'P~ ,~. 9~ - ~3' ~.~a '..'. ~ f , ~
a~s ,~.,w...~.~

B~~ ~% 2.5 1.9 C2 wt. % 7.8 4.0 AMOUNT OF SECOND COMPONENT T% 49 27 TERPOLYMER ALLOY

MFR (G/10 M 1.2 1.6 BUTENE /0 1.2 3.6 C2 WT% 3.8 2.7 DSC PEAK C 138.7 136.8 ONSET C 123.3 120.8 DSC DELTA H (J/g) 57.6 61.8 These terpolymers were made in a two stage process consisting of two autorefrigerated continuous stirred tank reactors in series with a gas phase fluidized bed reactor as it is described above in the process section. The process parameters for making the aforementioned terpolymers are given below.

W .~. _ m.v ~ W.. .~-y. u...~~lll.~ m.u . _ -._;J . ~ _a, . W ~;~ _:~.; n rw i T~I:J
rS;J _~~;l;l~lhe~:~: Il 1:.) 1 CL.I,L.V VV 1V.LVO ~~~'1~ CA 02279217 1999-7-27 TVV ~-VV (TV1 f.'.1V
9 i~1 ~.~
Replacement Page FxA11~P1.ES t7~F
BUTENE-ETHYLENE-PROPYLENE '.~CERP(DL~'iIZER ALLOYS
PROCESS CON711'I"TONS

'.'T _ ~ J..~ : r . _1..
f~~ .., ._.
~..
~ .
...-CATALYST F,I,4S ~4S
"-._ ALKYL, TEAL TEAL

ALKYL concentration l 100 m er total ene feexi DONOR MCMS MCMS

DONOR m er total r lene fend) 40 40 FIRST COMPONENT STAGE FIRST REACT4lEt rrEt~PF~TtrR~. C (F> so(14o) 50(140) PROPYI~NE FEED RATE xGr~ w s ~2.
1. ~
s< ~
1 so) so 'ENE FEED RATE KCrIHR (LBII~R) 0 9(20) BU'I 0.0 _ 0.35 0.1 HYDROGEN CONCEN'TRA'TION OLE%

C2 CONCkIVTItA.'~',~ON MOLE 9'0) 2.0 1.0 RESIDENCE TIIvviE 8 i ,.....ta..'~ r w l r . v _. .gyp:,. '1f. ~, T.,fr.: r L~~ r r v 'r.
~a ~::~. . n ~.....
y ._...
y~ _.._.. ___.._.__._ ,rr,.. ___._.~._ ~Mp~'I'~ C ~~) 53.8(129) 53.8(129) FRESH PROPYLENE FEED RATE KC~~R(L.817~R45. 45.
100) 100) FRESH BUTENE FEED RATE K HIHI:) 0.0 0.0 HYDROGEN CONCENTRATION (MOLE%) I 0.1 0.35 _ C2 CONCENThCATION OLE 96 2.0 1.0 RESIDENCE TLME --1.5 ~1.5 SECOND COM~~1EN'T STAGE REACTOR
-.__-TEMPERATd.TRE!C o 7p(lg$) 70 (158) PRESSURE SICr _ i 200 RESD~ENCE TIME --2 -~2 HYDROGEN CONCEH'TRATION MOLEYo 3.0 3.0 C2 CONC'ENTRAT'ION (MOLE 9'0) X 3.0 3,0 PROPY~.EIVF CONCENTRATION (MOLE9'o b7.0 66.0 BUT1E CONCEN1'R?ITION MOLE Yo 5.0 5.0 NITROGEN GONCENI'1LA'TION OLE9'o Z2.0 22.0 Earn I~ber Pra~ductio~o Fibers are prepared as spun, partially oriented yarns (POY) by mechanical take-xtp of the fiber bundle or folly oriented yarns (FOY) by mechanical draw after POY spinning from its extruded melt. 'this is accomplished on a fiber-line assembled by J.J. Jerkins, Inc. (Stallings, NC). The line consists of a S cm Davis Standard Extruder (with 30:1 length/diameter ratio) and 6 cc/rev Zenith metering pump forcing molten polymer through a spinneret plate of 72 holes of 0.4 mm and 1.2 length to diameter ratio. A metering pump rate of 10 rpm is employed which will yield a through-put of 0.625 g/holelminL~te.
Fibers are drawn from the 232 °C (450 °F) melt by an axially spinning unheated godet at 2000 m/min. The fiber bundle, expressed as total denier/total filaments collected at each rate is 203/72. The fiber bundles are collected for characterization as five minute runs by a Leesona winder. Fiber testing is performed on an Instron machine) Model 1122 coupled with the Instron computer that supports the Sintech Sima (Testworks II) computerized system for material testing. Instron Pneumatic Cord and Yarn nrips (Model 2714) used for gripping the samples. A sample with 2.5 cm gauge ~md 0.1 gram pre-load is pulled at 500 mm/min. to break. Break sensitivity was 95 percent drop in force.
Fibers are melt spun from both a 22 and a 100 MFR visbroken versions of ethylene-propylene copolymer alloys having an ethylene content of 7% by weight of the alloy. These embodiments of the invention copolymer alloy are produced as previously described. Fibers spun from a conventional traditionally polypropylene 2o random copolymer containing 3 percent ethylene which is subjected to controlled rheology treatment (post-reactor oxidative degradation) having 33 MFR (Exxon Chemical Company) PD-9355) and will serve for comparison Results obtained from tenacity and elongation testing of those fibers which are spun with take-up rates of 2000 mlmin are shown in Figure 7.
Fxamnle 9 S~unbond Process and Fabrics Spunbonded nonwoven fabric is prepared on a one meter Reicofil Spunbond line made by the Reifenhauser GMBH of Troisdorf, Germany. The Reicofil employs a 7 cm (2.75 in.) extruder with a 30:1 length:diameter ratio.
3o There are 3719 die plate holes, each having a diameter of 0.4 mm with LID=4/1.

I.CV LV Vv.I1V. LJO W UI 1C LCA 0~~~~~~~~ 1999 07-27 ~ T~VV, ,LVU lZ4~l'' , .
~1.V
'97B013.PCF
Replacement pa~~e - z~ -In the following examples, spunboad la~rats of 17 grm= (0.50 oz/yd=) ue prepared. 'The processing conditions are typic»1 of those employed in Reicofil operation. They include a 420°F (215 °C) die melt temQeramre, 45-SOQF {5-10°C) cooling air temperature, and a 21 mlmin belt sp~xd. The process parameters and the fabric properties of the spttnbond fabric are provided herein.

SPU1VBONlIE~ FA~iI~ICS

BASE RESIN 7wc % 39o RCP 5% RCP
~1VHN1'IaN E>aON CONV~FONAL
~93ss rte.

CR'D RESIPi YES YES YES

ly~g 33 35 35 2.4 23 2.4 SPQNBOND PBtICE~ PAIi;AMETERS

~gl gyp. C 2i5.5(420F) 215.5(420F) 215.5(42t~F) THROiJGH PC'T RATE
0.35 ~ 0.35 0.35 AIB JET' SP~Lb mlmin2,000 2,000 2.~

AIB JET TElIIp C 4,4 I 4.4C(4Uf' 4,4CX
(I~

FIB1H'.R DIAMETER :.5 .'.5 2;
aticrons B4NbING TEMP.C 98.8(210 11 Z30 104.41220) R~~C ~~T~

S4~ESS ( i 0.33 l 0.96 0.55 BASIS WEIGHT (~aaslmZ)-a I 4o i 40 40 to Exatmnle 10 ~txosaect'rvel Dde~t Blosvin~ Procedure Melt blown fabric layers are prepared employing a 51 cm (20 inch) Au,-urate Producxs Melt Blown line bulk by A,ccuweb Mekblown Syt~tams of Hillside, NJ. The extruder is a 5 cm (2 in) Da3ris Standard with a 30:1 Iength:diameser ratio. 'fhe die aozziie has 501 di~: holes. The diameter or each is 0.4 zum ( 0.15 in. ). Die length: diameser ratio i~ 15: ? and the pit gap is set to 0.15 mm {0.060 in.). Mek blown fabric layers sre prepared whh weights of 30 glm=
(0.88 ovyd').

,_ .

Representative processing conditions include a polymer melt temperature of 520°F (271°C) and an air temperature of 520°F
(271°C).
The technology of preparing meltblo~,~m fabrics is also well known in the art of nonwoven fabric preparation production. An overview of the process may be obtained from "Melt Blown Process", Melt Blown Technology Today, Miller Freeman Publications, Inc. San Francisco, C.A, 1989, pps. 7-12.
Optimum Bonding TemJ~erature Determination The Optimum Bonding Temperature (OBT) is found by evaluation of the thermal bonding curve. The OBT is the point-bond calendar temperature at which 1o the peak bonding strength for a laminated nonwoven fabric is developed. The thermal bonding curve and OBT is determined in two steps.
1. Unbonded fabric laminates are passed through the nip of heated calendar rolls. The rolls are heated at temperatures between 200°F (94°C) and 320°F ( 160°C) in 5°F (-2.8°C) increments. A
series of fabric samples each bonded at a different temperature is produced.
2. The machine direction (MD) and transverse direction (TD) tensile strengths are then measured as set forth in ~~STM D 1682-64 (reapproved 1975).
The bonding curves are graphic cornparisions of calendar temperature and peak bond strength in MD and TD.
2o Comparisions of bonding temperature and peak bond strength on the bonding curves permits identification of the OBT.
Control Rrsins In the examples which follow) a cornmercial 32-38 dg/min MFR controlled theology polypropylene random copolymer polypropylene having 3% by weight 2s ethylene is employed in preparation of corvtrol spunbonded fabrics. The specific polymer is PD-9355 available from Exxon (:hemical Company, Houston, TX.
Control melt blown fabrics are prepared from Exxon's commercial PD-3795G which is a peroxide coated granular polyrpopylene homopolymer having a MFR of 800 dg/min.

WO 98139384 PCT/US98l04287 Prospective Example 11 Preparation of SM AND SMS Fabrics Lanninated with Invention Conolymer Allovs An unbonded, bilayer (SM) fabric consisting of a spunbonded layer (S) and a melt blown layer (Nl7 is prepared. The M layer, made with the commercial 800 MFR polypropylene, is directly extruded on nhe web of the S-layer. The latter is made from a 3 5 MFR invention ethylene-propylene copolymer alloy having an ethylene content of 7% by weight of the copolymer. This embodiment of the copolymer alloy invention is described previously and its main design Io characteristics and properties are shown in Table 1. The OBT of the bilayer fabric is then evaluated by point bonding of the fabric with heated calendar rolls and subsequent preparation and analysis of a thermal bonding curve. The anticipated properties are given below in Table 5 as compared to a control bilayer fabric.
A second S layer made from the copolymer alloy may be laminated either I5 on-line or offr line to form a composite SMS fabric.
Many modifications and variations besides the embodiments specifically mentioned may be made in the compositions .and methods described herein without departing from the concept of the present invention. Accordingly it should be clearly understood that the form of the invention described and illustrated herein is 2o exemplary only) and is not intended as a limit~ition on the scope thereof SM PROSPECTIVE. EXAAiPLES
S-LAYER M-LAYER OBT STRENGTH BARRIER SOFTNESS
8r.

(F) FILTRATION

EXAMPLE 7% PD-37956 210 GOOD GOOD ~ EXCELLENT

COPOLYMER

ALLOY

Claims (7)

CLAIMS:

We claim:

1. An ethylene-propylene copolymer alloy, said alloy having a substantially single glass transition temperature, an ethylene content of from 5 to 8 % by weight of the alloy, and a meat flow rate of from 3 to 150 g/10 minutes said alloy comprising:

(a) an ethylene-propylene random copolymer having an ethylene content of from 0.1 to 6.0 % by weight, said random copolymer having an MFR of from 0,1 to 250, present in an amount of from 4 to 90% by weight of the alloy; and (b) au ethylene-propylene bipolymer present in an amount of from 10 to 60% by weight of the alloy, said bipolymer having an ethylene content equal ar lower than a critical value to ensure the miscibility of the random and bipolymer copolymers.

2. A multi reactor process for producing the miscible ethylene-propylene copolymer alloy of claim1, comprising:
(a) polymerizing a mixture of ethylene and propylene, in the presence of a catalyst system to form a random copolymer having an ethylene content of 1-39% by weight in an amount corresponding to 40-90% by weight of the alloy;
(b) in the presence of said catalyst containing random copolymer, further polymerizing a mixture of ethylene and propylene, and controlling the ethylene (propylene mole ratio in the reacting medium at or below a critical value to form an ethylene-propylene bipolymer that is miscible with said random copolymer.

3. The process of claim 2, wherein the random copolymer is trade in a liquid reactor and the bipolymer is made in a gas phase reactor.

4. Use of the ethylene-propylene copolymer alloy of claim 1 in a soft nonwoven fabric application.

5. Use of the ethylene propylene copolymer alloy of claim 1 in a diaper application.

6. Use of the ethylene-propylene copolymer alloy of claim 1 in a diaper

7. Use of the ethylene-propylene copolymer alloy of claim 1 is a disposable garment.