CA2123793A1 - Polymeric monofilament and felt made therefrom - Google Patents

Abstract

According to the present invention, there is provided a monofilament, based on the total weight of the monofilament composition, (a) from about 10 weight % to about 60 weight % of a functionalized polyphenylene ether, (b) from about 40 weight % to about 90 weight % of a polyamide, and (c) from about 1 weight % to about 30 weight % of a functionalized elastomeric polymer, and industrial conveyer belts fabricated therefrom.

Description

WO ~3/13~1 PCr~US92/1073~
2123~93 POI.Y~RIC ~$O~OFII~T ~ F13~T ~aDl3 T~E~SFRO~
ROSS R~ æ TO REI.ATED APP~ TIO~
This application i~ a continuation- in-part of application Ser. No. ~14,977, filed on December 24, 1991.

=~ ~
~ e prese~t i~e~tion relate~ to a polymeric monof ~ lament and to a fel~ fabri~ated ~herefrom.
D~~c~p~1o~l o~ t~ Prior Ar~
Polymeri~ monof ilameTlt~, in general, are produced by melt-ext~u~ion proce~es a~ i8 well kno;~ irl ~che art. A
polymeric resin iY melt - extruded into co~ti~uou~ ~tra~ds 20 monofilame~t~ by an extrude!r equipped wi~h a moxlofilament die ~ a~d then the resul ing monof tlame~t are que~ched to orm ~olid ms~of ilaxnexlt~ reaf ter, th : 30l ~d mc~nof ilame~ts are ~u~j ected ~o a qtret~ch dxawing proce~
al~o knowrl a~ a~ orientation process, which irlcludes o~e or 25 more 3~cep~ o~ alter:~ati~gly heat tretch~ g and quenching proce~ure~, t o impaxt phy~ical ~trength.

Wc~Yen endle~s belt~ for co~veying:~and ~iding produc~s under ~ ufactllre axe widely u'cili~ed in variouC indu~trial 30 prof~es~e~ and are one group of numerou~ applicat:ions~ where polymeri~ mo~ofilame~ts are u ed exkensi~rely~ a~ of sus~h con~reye!r bQlt applicatio~ rol~e har~h chemical a~d ~e~?Q~a;~ure en~iro~nent~ in which ordina:ry ` polymeric m~erial~ canno'c with~tand.
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illu~tration of con~eyer b~lt applications in which con~yer belt~ are e~po~ed l:O har~h e~rironm2ntc~ the feltQ ~or paperma}~in~ mach~ are de~cribed below. ~
papermaking ~3achin~ ~ in e~en~e, i~ a de~rice f c)r WO 9?~/13~51 PCI'/USg2/1~73'1 ~equentially removing water from paper furni~h. A typical papexmaking machine i~ di~ided in~co three sections~
f ormi~g, we~ - pre~, and dryer ~ections . In the f orming section, the ~lurry of paper furrlish and water i~ depo~ited 5 on a ~orming grid and water is drai~ed, lea~ing a paper web of about 75 weight perce~t water content. The resulting web is carried into the wet-pres~ section on a felt twet-pre88 felt) a~d pa~ed through one or more of nip pre8~3e9 to redus:e the water content of the web to below about 65 10 weight p~rcent. The web i~ then rarried to the dryer section and dried by co~tactin~ hot dryer cylinder~ on a ~elt (dryer felt) to reduce the water conte~t of the web to below about 8 weight percent.

Although the felt~ for different section~ of papennaking machine must be de ig~ed a~d fabricat~d to meet specific r~eed~ e~sential to each ~ectio~, the ~elt~ ~t po~s~ ~he general characl:~ri~tic3 of dimen~ional ~tabil~ty, reRi~'ca~c~ to che~i~al aTld thermal degra~a~ion~, - 20 re~i~tanGe to abra~ioIl, resilie~cy - aTld tenacity. Both metal and 3y~thetic polymexs have been u ed to fabric~te ~he felt~ with ~arying degree of UCGe9 Me~cal :Eabric fel~c~ pro~ride superior therznal characteristicq, but are difficult to hasldle, have poor flexural re~ ta~ce and are 25 pro~e to chernical attack a~d corro~ion. The~e di~advantageou3 characteri ~3tiC8 of metal fabric felts led to a wide arceptance of f~ric felt~ made fr~m a variety of syrlthetic polymer~ such a polyolef in3, polyamides a~d polye~ter~. ~owe~er, such ~thetic polymer fel~ al~
30 e~ibi~ cerkai~ di~ad~antages. Polyolefi~ felt~, for exa%~ple, are dime~ionz.lly ~table bu~c have low thermal stability and are ~o~ rexista~t to the ~hemical~ ukilized i~ the papermaking proc~3~s . Felt~ made f rom polye~ters provide dime~io~al ~tabili'cy, a~d are re~ista~t to 35 abra3io~ a~d chemicals, but are prone to high te~perature W~ ~3/13251 PCI`~US92/10734 2~2'~793 hydrolysis. Felt~ made fro~n polyamide~, quch a nylon 6 and nylon 6, 6, provide abra~ion resistance, resiliency and tenacity, but do not ha~re the required climensional ~tability .
S
There are m~ny coxnmercially a~ailable ~pecialized synthetic polymers that are u eiEul for the felt applicatio~ Currelltly, one of the mo~c widely u~ed ~ thetil- polym~rs to ~abrica~ce f~lts for pape~nakirlg 10 machi~e~ are polyam~d~ ha~ g a loYlg carboIl-cha~n, such as nylon 11) ~ ~ylo~ 12, ~ylo~ h f 10, a:~ld nylo~ 6/12 . ~uch polyamide provide tenacity, re~iliency and abrasion resi~tan~e a~ well a~ dimensional ~t~bili~y.
Polyaryletherketone fa}:ri~ al~o ha~e bee~ utilized in the felt applic~io~ a~ di~cloeed i~ U.S.P. 4,3~9,501 to DiTullio. U.S.P. 4,159,~18 to So~arls di~clo~s yarn~
~abricated ~ro~ li~uid-cry~tal polymer~ ~uch as aramld~3, that are u8e~ul i~ the ~ ufacture of wo~e~ felts.
~lthough these ~pecialty polym~r felts ~rovide good propertieR t~at are re~ui.red i~ the papermaking felt applic~tion~, the high co~t of the e ~pecialty polymer~
preclude~ wide acceptance of ~uch felt~. Con eguently, it would be de3ixab1e tv have le~: expenRive polymeric material~ that exhibit the required characteristic ~ui~able for the felt app~ication.

The pre e~t inventors i~eRtigated pol ~ henyle~e ether/polyamlde ble~d compo~itio~ to create blend compo~itio~s that are highly ~uited for u~e in various monofilamen a~d con~eyer belt application Although, ~
i~ k~ow~ i~ the art, polyphenyle~e ethers and polyamides are incompatible polymers a~d the two polymer~ must be compa~ibilized to fo~m ble~d co~po~itio~ of any u~e, there axe num~rou~ prior art teachi~g~ of polyphenylene ether/polyamide ble~d moldi~g compo~kion~, e.g., ~.S.

WO ~3/13251 PCr~U~;92/~734 Paten~ ~,379,792 to Finholt~, 4,315,086 to Ue;no et al., and 41732,938 to Grant et al. However, the u~e of polyphenylene ether/polyanRide blends for monofilamen~
application~ ha~ not been conQiclered in the prior art.
5Thi~ i~ becau~e it i~ knowrl in the art that only the blend composition~ of c~m~atible polymer~ can succes~fully ~e fabricated i~to u~Pful mo~of ila~nent~ without breaking the monof ilamen~ ~ during the ~tr~tch drawing proce~ and that tha co~paJcibility level attained by the pric: r ar~
10polyphenyleIle ether/polyamide blerld molding Co~po2itloD~
are not ~uf f iciently hi~h e~ough to prod~ce u3eful mo~ofilamerlt~. The com~atibility of 'che two polymer~ in ~he prior art polypheIlyle~e ether/poiyamide bler~d compo~itiolls are not ~o high as to form homogeIleou~ blend, 15~d they contai~ relati~rely large domains of one polymer within the co~ti~uous matri.x o~ the ~ther polym~r. Such par ially con~patible polyphe~ylerle/po}y~id@ lbleIld~ c~ot be u~ed to produc~ monof ilamea~ ~ince the extrusion of dime~iorlally ullifonn monLo:Eiiame~t~ from ~uch partially 20ct~n~patible blend i3 not practical and the re~ulti~g monofilamen~s do ~ot have unifoxm phy~i~al properties throughout the length of the f ilame~ts ~ In addition O ~he monofilame~t fabricated rom 3uch partially compatible ble~d~ cazmot Yucce~sfully be Rubjected, without breaking ~5the mo~ofilame~t, to the ~tretch drawing proce~, which i~
a ~ece~ary proces~ to im~art ~trength to the monofilam~t.

It would therefore be deBirable to pro~ride highly compatible a~d homogeneou3 polyphe~ylene ether/polyamide 30blend compo~itio:n~ that are ~uitable ~or fabri~ati~g quality monofilaments and coIl~reyer bel~ ~abric~ made theref rom .

S ,~R.~ 0~ 1~",;~,~0,~
35P~ct::o~ding to the pre~ent i~ e~tioll~ th@re i~ provided 3~51 2 1 2 3 7 9 ~ P~r/US92~10734 a monofilament compri~ing, ba~ed on the total weight of ~he monofilameilt, (a) from about 10 weight ~ to a:bout 60 weight % of a ~unctionalized polyphenylene ether, ~b) ~rom abs:ut 4 0 weight ~ to about 9 0 weight ~ of a poly~nide, and ( c ) from about 1 weight ~ to about 30 weight ~ of a functionalized ela~tomeric polymer, wherein the monofilament exhibit~ a tenac~ ty of at least 3 gram per de~ier as mea~ured ill accordance with the AS~M D2256-90 breaking te~acity procedure,. - ;
' ' ' ' ' :~
The polyphe~yle~e e her sultabl~ for the present i~ve~tiorl preferably ha~ an inheren~ vi~c08ity between a~out 0.3 dl/g and about 0.1~ dl~g, more preferably between about 0 . 45 dl/g and aboul: 0 . 75 dl/g, m~t preferably between about 0.5 a~d about 0.7 dl~gl ~hen mea ured in chloroform at 30C, a~d the polyamid~ ~ui~able for use hexein pre~er~ ly ha~ a r~uced ~i~o~1ty between about 1 dl/g to about 4 dl/g, more! preferably:between about 1~5 dl/g to about 3~5 dl/~ mo3t preferably bet~ee~ about l.B
e 20 a~d about 3.0 dl/g, when mea~ured i~ m-cresol at 25C.

~ There i~ further provided herein a felt formed from a mo~ofilame~t compri i~, based on the total weight of ~he ~elt, (a) from abou 10 weight ~ to about 60 weight ~ of a funct onalized polyphe~yle~e ether, ~b) from about 40 weight ~ to about 90 weight ~ of a polyamide, and tc) from about 1 weight ~ to ab~ut 30 weight ~ of a ~u~tionalized elastomeric polymer.

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Th~ monofilame~t of the pre~e~t i~entio~ i5 a les3 eo~ly polymeric monofilam~t ha~in~ dim~io~al ~ability, abra~ion re~i~ta~ce, chemical re~i~ta~ce, hydroly~
resl~t~c~ a~d high temperature 3tabllity a~ well as 3trength a~d tenacity. The felt of t~e pre~e~t in~en~ion pro~ide~ excelle~t ch~mical and thexmal characteri3tics WO ~3/1~51 P~`/llSg2~0734 21237Y~ 6-that are Quitable f or varied induqtrial ~on~eyer belt application~, including the papermaking machine felt appl~ caltio~Q .

- 5 TAI:t 13D D13SCRIPTI~W OF T~rE3 I~v~r~
A3 mentio~ed above, the monof ilam2~t of the pre~en~
in~ention comprise~, ba~ed on the total weight of the monofilament, (a) from ab~ut 10 weight ~ to about 60 weight ~, more preferably frQm about 15 weig~t ~ to about 50 weight ~, mo~t preferably from about 20 to about 40 weight %, of a functio~alized p~lyphenylene ether, (b) from abou~c 4 0 weigh~c ~ to about 9 0 weight ~, more pref erably f rom about 45 weight ~ to about 85 weight ~, mo~t preferably from about S0 weight ~ to about 80 weight ~, o~ a polyamide, a~d (c) from al:out 1 weight ~ to about 30 weight %, more pre~rably f rom about 1. 5 weight ~ to about 10 weight percen~, mo~t preferably from abou~ 2 weig~ to about 5 weight %, of a fu~ctionali2ed ela~tomeric polym~r.
The i~ta~ mo~o~ilamerlt pro~rid@ dime~iollal 3tab~ lity, abrasion re i~ta~c~, ch~cal re~i~caIlce, hydroly~
resi~ance :and~ high temperatur~ tability as well a~
streIlgth and te~acity, re~dering the monofilament to be~an excell :nt polymeric material for use i~ the i~du~trial cc2~reyer b lt application9 where the belt i expo ed to chemically arld thermally har~h erlvironmeIlt . ~ The moIlofilament of the pre9ent invention e~ibit3 a tenacity of at le~t about 3 gram per denier (gpd) ,: preferabl~ at lea~t about 3 . 5 gpd, more preferably at lea9t 4 . O gpd, a mea~ured in accorda~ce with the ASTM I)2256-90 ~reakiny tenaci;ty pro~ure.

O~e compone~t of the prese~t mor~of ilament is a polyphenyle~e ether. Polypheny~lerle ether9 are amorph~u~
non-polar polymer~ ha~ g excellent electrical a~d mechanical propçrtie~, heat and hydroly~i~ re~i ta2lce~, and . .

WO 93/a32s1 Pcr~uss2~10734 2~2~7~

dimensional stability. The polyphenylene e~her3 u~eful i the pre~ent invention include homopolymers and copolymer^~
repreRented by the f s:)rmula:

~ Q Q4 ~o :
l Q2 Q1 m wherei~ Q1 through Q,, are ~elected indepe~dently of one a~oth~r f rom he group consi~cing of : hydroge~ arld hydrocaxboIl radicals and m de~Lo~e~ a nu~er s~f at lea~t 30.

The polypheTlyle~e e'ch~rs czm be f ormed by any of a number of cataly~cic and ~on-catalyltic proce~se fr~m corre~ponding phenols or reacti~e derival:i~e thereof. 13xample~ o such proce~e~ of preI?ari~g pol~yphen~le~ ether~ are de~ribed in U.S. Pate,t~ 3g306,875; 3,337,50~, ~d 3,787,361.

Specif ic ex~le of sui~ ble ~ub~ra~e~ phenol 2û compound~ i~clude phenvl; o-,m-, or p-cre ol; 2~,6, 2,S-, 2,4-, or 3,5-dimethy phenol; 2-rnethyl-6-phellylpheTlol;
2, 6-dipheIlyl-pheIlol; 2, 6-diethylph:enol;
2 -methyl - 6 - ethyIphe~ol; and 2, 3, 5 -, 2, 3, 6 - or 2, 4, 6 - trimethylphe~ol O The~e pheIlol compounds may be used as a mixture. Other phenol ~ompou~d~ which can: be: u~ed include dihydric phe~ol~ (e~gD ~ b;ispherlol A, t abromobi~phellol A, re~orGinol, and hydro~uinone) :.

Pref erred polyph~nylene ether~ sui~able f or the pre~ent in~rentio~ i~clude poly(2,6-dimethy1-1,4-phen~le~e ether), poly t2-m~thyl~ phe~yleIle ether~, poly ~ 3 -me~hy~ - 1, 4 - phenyle~e ether j, poly ( 2 9 6 - diethyl -1, 4 -phenyle~e ether), poly (2!6-dipropyl ~ /4-~h Ilyle2le eth~r) ~ poly(2-methyl 6-alkyl 3~ phenyle~e eth~r~, ~oly ( 2 , 6 - diGhloromethyl -~9~/13~S~ P~T/VS92/107~

1,4-phenylene ether), poly(2,3,6-trimethyl-1,4-phenylene ether), poly (2,3,5,6-tetramethyl-1,4-phenylene ether), - poly(2,6-dichloro -1,4-phenylene ether), poly(2,6-diphen~l-1,4-phenyle~e ether), poly(2~5-dimethyl-1,4-phenylene ether), and blends and copolymer~ thereof. Of these, the preferred pol~phenylene i~ poly(2,6-dimethy~-1,4-phe~yle~e ether).

The suitable polyphe~yle~e ether polymer for the present inventio~ are fuact o~alized with a fu~ctionalizi~g co$pou~d ha~ing a carbo~-carbo~ double bond or triple bo~d a~d a fu~ctional group ~elected from the group co~isti~
of carboxylic acid~, anhydrides, glycidyl functionalitie~, a~d mixtures thereof. The reacti~e groupq may be randomly distributed along the length of or at the ends of the polyphe~yle~e ether cha~, The carboxyl or car~o~ la~e functio~ality can be upplied by r~a~ti~g pol " he~yl~
ether with a modifier o~ ethylenically u~aturated monocarboxylic acidq, su~h a~ acrylic and methacryl~c acid~, a~ well as dicar~o~ylic acid~ h~ving from 4 ~ 8 carbo~ atoms~ Illu~tratiYe o~ ~uch acid and anhydride~ are - maleic acid, maleic a~hydride, fumaric ~cid, itaconic acid, itaconic anhydride, a~d mixture ther~of.

Prefer~bly, the functionalized polyphenylene ether of the pre~ent in~ention contai~ from about 0.05 to about 5 w~ more preferably from abou 0.1 to about 1.5 wt~, of ~he functionalizi~g compou~d ba~ed o~ ~he total weight of polyphe~yle~e e~her.
3~ ...
The fu~ctio~alized po~yphenylene e~her i9 preferably prepaxed by melt extrudl~g polyphenylene ether wi~h the funct~onalizin~ compou~d in the pre~e~ce o~ from about 0.01 wei~ht ~ to ~bout 0.2 weight ~, more preferably from about 0.05 weight ~ to 0.1 weight ~, of a free radical initiator WO g3/132S1 2 ~ 2 3 ~ 9 3 PCT/U$92/~734 that help~ i~itiation of the functionalization. Useful free radical initiator9 include peroxides ~uch as dialkyl, diaryl, and dia~yl peroxide~, uch a~ dicumyl peroxide and the lik~ Other u~eful ~ree radical i~itiator~ include - 5 N-bromoimide~ ~uch a~ N-bromo~uccinimide, dialkylazos and ~he like.

The polyphenylene e~her herein may be pre-fuIlctionalized u~ing an ext:ruder a~d pelletized iIl order ~co 10 provide a fully functi~alized and h~mogeneous polyphenylene ether compo~ition that can ea ily be mixed with the rest of 'che co~poYition con tituent~. In an alternative, the polyphenylene ether snay be funcitionalized during ~he final melt-blending pxoces3 by mixing ~n 15 Immodified polyphenylene e}:kaer, a functiorlalizi~g compou~d and a free-radical i~iti.ator along with all other co~ cuent~ of the pre~e~t pol}~phenylene ~th~r~nylon ~lelld co~o~ition, producing the mo~c)f ilameIlt in a one- ~tep proce ~ other con~onent of the pre e~t monof ilame~t i~ a polyamide. PQ1Yamide8, al~o co~nonly k~own in the art a3 ~ylo~, are ~emi- crystalline, polar polymer~ havix~g abra~ion ra~istance, 3trength, toughne~s and sol~en~
25 re~i~ta~c~ as well a~ good proce~ ibility. The polyamides ~uitable for the present i~ve~tion include tho~e which m~y be obtaiIled :by the pol~merizatio~ of a diamiIle having two or more C~OTl atom~ betwee~ the amine termi~al groups with a dica~bo~ylic acid, or alternately tho~e obtai~d by th~
30 poly~rizatioll of a monoan~no carbo~yllc acid or an internal lactam thereof. Ge~eral proce~res u~eful for he preparatio~ of polyamide~ are well k~owD to the ar~, a~d ~he d~tail~ of their f oxmatio~ are well de~ribed, f or ex~leJ under the heading "Polyamides" in the E2lcyclopedia 35 of Chemical Tech~ology publi~hed by Johrl Wiley & Son~, I~c, WO ~3/132Sl P~r/U~92/10734 21237~3 Vol. 18, pp~.32~-~36, (1984).

Suitable lactam~ that ca~ be polymerized to produce polyamides include lactam monomers ha~ring about 3 to about 5 12 or more carbon ato~r~, pref erably f rom about 5 to about 12 carbon atom~ . Non- limiting example~ of ~uch lac~am monomer include propiolactam, ep~iloncaprolacta~
pyrollido2~e, poperodone, valerolactamr cap~ylac~am, laury~ lac~ , etc. Suitable polycaprolactam ca~ be 10 h~m~polymer~ of onP of the abo~e or ~imilar ~ actam monorner~, or oopolym~r3 of two or more of ~he lactam monomer~.

Suitable diamine~ include those having the formula ~2N(CH2)nNH2 whereinnpref~rablyi~ an integer of1- 16, and i~clude~
~uch compound~ a~ trimethyl~nediaml~e, tetr~methylened~amine, pe~tamethylenediami~e, hexamethylenediamine, octamethylenediami~e, decamethyle~ediamine, dodecamethyle~ediamine, a~d hexadecamethylenediami~e; aromatic diami~e~ ~uch as p-phenylene~iami~e, m-~yle~ediamine, 4,4'-diami~odiphenyl ether, 4,4'-diaminodiphenyl ~ulphone, 4,~
diami~odiphe~ylmethane, alkylated diamine~ ~uch a~ 2,2-dimethylpentamet hyl enediamine, 2~2, 4-trimethylhexamethylenediamine, and 2,4,4-trimethylpe~t~ethyle~ediamine, a~ well a cycloaliphatic diami~e~, such a~ di~inodicyclohe~l~ethane, and other co~o~ds.

~ e dicarbo~lic acid~ u~eful in t~e ~o~tion of poly~de~ are pxefer~ly tho~e which are repre~e~ted by the gene~al fo~la HOOC-Z-COOH
~ ':
wherein Z i9 represe~tative of a divalent aliphatic radical containing at lea~t 2 carbon atoms, such a~ adiplc acid, 3ebacic acid, octadecan dioic acid, pimelic acid, subeic acid, azelaic acid, undecanedioic acid9 a~d glutaric acid;
or a dival~nt aromatic radical, ~uch a i~ophthalic acid a~d ~erephthalic acid.

By mea~ of e~ample, .uitable polyamides i~cluds:
polypropiolac am (nylon 3), pol~pyrDllido~e (~ylon 4)~
polycaprolactam (~ylon 6), polyheptolac~am (nylon 7), polycaprylactam (nylon 8), polyno~a~olactam (nylo~ 9), polyundeca~eolactam (nylo~ 11), polydodeca~olactam (nylo~
12), poly(t~tramethylen~diamlne-~Q-adipic acid) (nylon 4 , 6 ), poly ( tetramethyle~ediamine - ~Q- isoph~halic acid) (nylon 4 , I), polyhexamethyleIlediami~e adip~de (nylon 6 , 6 ), polyhexamethyl~Ile azelaiamide (~ylon 6 ~ 9 ), polyhexamethylene ~ebacamide (~ylo2l 6 ~10), 2-0 polyhexameth~rleIle i~ophth~lamide (~ylon 6, I), polyhexamethylene terephtchalamide (nylo~ 6,T), polymeta~lene adipamide (nylon MXD:6), poly (hexameth~lenediamine- o-dodecanedloic acid~ (nylon 6,l2), poly(decameth~le~ediamine- o-~ebacic acid) (nylon lO,lO), poly(dodPcamethylenediami~e-çQ-dodecanedioic acid) (nylon l2~l2)~poly(~a~4-~minocyclohexyl]methane-~Q-dodecanedioic acid) (PA~-12), a~ well aq copolymer~ of the above polyamlde~. By way of illu~tratio~ an~ ~ot limi~ation, such polyamide copolymers i~clu~e: caprolactam-he~am~thylene a~ipamide (nylon 6/6,6)~ hexamethyle~e adipam~de-caprolaCt~ (nylon 6,6/6), hexame~hylene adipamide/h~xamethylene-i50p~thalamlde (n~lo~ 6,6/6IP), he~ame~hyle~e adipamide/hexamethylene-~erephthalamide (~ylon 6,6t6T), trim thyle~e adipamide~he~amethylene-azelaiamide (nylon tximethyl 6,2/6,2), a~d he~amethyle~e WO(~3/13251 ~ 1 2 3 7 ~ ~ PCT/US92/10734 adipamide-~examethylene-azelaiamide caprolactam (nylon 6,6/6,9/6) a~ well as others polyamide copolymers which are not particularly delineated here~ Blend~ of two or more polyamideq may also be employed. Of these, the prefarred are polycaprolactam (nylon 6), polyhexamethylene adipamide (n~lon 6/6~, and copolymer~ and blend3 thereof.

A~ a preferred embodiment, the monofilament of the pre~e~t inve~tion i~ ~abricated fr~m the mo~o~ilame~ blend composition of the pre~nt inve~tion utilizing a high vi3co~ity polyphe~yl~ne ether and a h~gh ~i8co~ity polyamideO It has surprisi~gly been found ~hat ~he tenacity of the monofilame~t i~pro~es ~ig~ificantly without ~acrificing other useful pllys~cal and chemical properties when high vi~co~ity polyph~nylene ether and polyamide are employed in the blend compo~3ition~ The polyphenylene ether ~uitable for the pre~e~t ~ve~tion pre~e ~ l~ h~ an i~herent ~i~co~ity between about 0.3 dl/g and about 0.8 dl~g, mor@ preferably b~t~ee~ about 0.4S dlJg a~d 0.75 dl/g, mo3t p~ef~rably b~twee~ about 0.5 dl/g and 0.7 dl/g, a~ measured in chloroform at 30C, a~d the polyamide ~uitable for u~e herein preferably ha~ a reduced ~isco~ity between about 1 dl/g to about 4 dl/g, more preferably be~ween about l,5 dl/g to about 3.5 dl~g, most preferably between ab~ut l.8 dl/g to about 3.0 dl/g, a~ measured in m-cre~ol at 25C.

O~e further component of the monofil~ment compo~i~on of the pre ent inventio~ i~ a functio~alized elas~omeric pol~mer~ The ela~tomeric polymer~ ~uitable for u~e herein may be block or graft copolymer~ t i.e., the ela~tomeric pol~mers are made fro~ reacti~ mo~mers which fon~ part o~
~he polymer chai~ or bra~che~, or graf~ on~o the polymer.
Such sui~able ela~tomeric polymer~ include olefi~ic ela~tomer~, ~tyre~ic block copolymer~, core/~hell nubber~, WC) 93/13251 2 1 2 3 7 9 ~ PCr/~S92/10734 and mixture~ ~chereof.

An s~lef inic ela3tomer iG de~ined a~ having an ~STM
D638 ten ile modulus of le9s ~han about 40, OûO l?~i (276 MPa), typically le~s 'chan 25, 000 p~i (172 MPa), and pre~erably les~ than 20, 000 p~i (138 MPa.. ~ . U 9 e ~ u olefinic ela~tomer~ include block and graft elastomeric copolymer~ of one or m~re of ethylene, propyl~e, butyle~e, i~opropylene a~d i~obutylene. Pref~xred olefinic 10 copolyme~r~ ~uitable f or u~e hereiIl are ~h~ copolymerY of ethylen~ d at l~a~t one a-ole~i~ sel~cted fr~m a~-olefi~
having 3 to 3 carbo~ atoan~, uch a propyle~e, 1-butene, 1-I?entene, l-hexene, 1-hepte~e and 1-oc~ten~. The copolymer~
may also co~tairl ~ther mo~Iom~r~ such as die~es that are 15 conjugated or non~onjugated. Preferred dieIle~ include butadiene, 1, 4-hexadie~, dicyclopeIl~adi~, methylene ~orborene ~d the llke. O~ the~e cop~lymer, preferred ethyle~e/a- ole~in copolymexs are ethylene propyle~e a~d ethylene propylene diene copolymer~ having, ba~ed on the 20 e~yle~e, from aboul: 30 to about 60 weigh~ per~ent of the c~-olefin, such as ethylerle/propyle~e nlbber, ethylene/1-butene rubber, ethyle$le/butadiene ~ubber and the like, and ble~ds thereof~ The mo~t preferred i9 ethylene/propyle~e ruDl:~er O
2~
13la~tomeric polymer~ suitable for the pre~ent in~e~tio~ al~ lude ~tyrellic block ropolymer~. The ~tyre~c block copc~ r3 i~clude diblock copolyTnerY, ~uch a~ ~tyre~ne - ethylene/buP~rlene aIld styrene - ethyl~ne~propyle~e 30 block ccl,polym~r3, a~d triblocl~ copoly~ers, Yuch a~ ~tyre~e-e~hyler~e/butylene - ~'cyrene a~d 3tyren~ ~ ethyïene/propylene-~tyr~e. The styrenic block copolymer~ suîtable ~or the pre3e~ ~e2~tio;n are co~nercially a~railable, ~uch a~ ~rom Shell Chemical Co. urlder the l:radename :Itrato~.
3~

WO 93~1325~ PCr/US92/10734 Another group of ela~tomeric polymer3 quitable for the pre~ent in~rentioTl are the core/~hell r~bbers c:ompri~i~g a core of cros~linked polybutadiene or butyl acrylate copolymer, and a shell of polymethylene methacrylate and 5 optionally ~tyrene and/or acrylonitrile. The core/shell rubber~ ~uitable f or the pre~e~t in~rention are disclo~ed, for exaIr~ple, in U.S. PatO No. 4,495,324, the di~closure of which i~ hereby i~corporated by ref erence .

Ac~ordin~ to th~ pre~ent in~rention, the ela~tomeric polymer i~ funcl'cionalized with carbo;~yl or carbo~rlate functiorl~lities. The fu~ctionality can be ~upplied by reac~ing the olefi~ic ela9tomex with an unsatura'ced gra~t moiety takeIl ~rom the cla~s con~i~ting of a~"B-e~hyle~ically 15 url~aturated dicarboxylic ac:ids ha~ri~ from 4 to 8 carbo atoms and deri~rative~ thereof. Illustrative of ~uch aaid~
and deri~ra~ve~ ~ ar~ maleic acid, ~leic a~hydrid~, maleic acid mon~aethyl g~ter, met~l ~alt~ of maleic acid m~oethyl e~'cer , flamar~ c acid ,: furnari~ acid mono~thyl e~ter , itaconic 20 acid, vinyl be~zoic acid, ~i~yl phthalic acid, me~al alt~
of fum~ric acid ~m~oethyl es'cer, monoe~cers o~ maleic, fumaric or itaco~i c acid~ where the alcohol i methyl~
propyl t i~opropyl, butyl, i~obutyl I hexyl, cyclohexyl, octyl, 2-ethyl hexyl, decyl, ~tearyl, methoxy ethyl, ethoxy 25 e~hyl, hydroxy ethyl, and the like. The functio~al moiety can be graf ted to the olef inic ela~tomers by ~ a~ graf t proces~es known to the art, including but not limi:~ced tc the proce~ de~cribed in U~S. Patent No~. 3,48~,910;
3,480,5~0; 4,612,155 and 4,751,270. In p~rforming he 30 graft-polymerizatiorl of the ~ ctio~al moiety to thP
ela~tomer~, there have been utilized ~rariou~ method~ ~r i~itiating th~ grafti~g pol~nerizatio~ proce~ 3uch as ~-ra~r, X-ray or higt~-~peed cathode ray irrad~atio~ proceQse~, an,d a free-radical initi ator proc~8~ . The preferred 35 fu2lction~1ized ~lagtomeric pol~mer c:f the pre~nt in~rention W0 93/13251 Pcr/us92/~0734 contairl~ ~rom about 0 . 05 ~ to about 5 ~ by weight of the - functional moiety, rnore preferably from ~bout 0 . l % to about 2 ~, ba~ed on the total weight of the ela~tomeric poly~sler .
' S
The monofilament compo~lt' on xnay also ron ain one or m-re conventional additive~ ~own in the art to be uitable for ~ylon c~mposition3 ~uch a~ ~tabilizer~ a~d inhibitsxs c~f oxidatiYe, thennal, a~ ultra~riolet light degradatio~, 10 lubrica~t~, cs~lora~t~ cludi~g ~e~, and pigmeni::a~ flame-retardant~ ~ pla~ticix~r y ~ini~hers a~d. the like .

Illu~trative of the oxidative and thermal stabilizers uitable for u~e in the preseIlt inseIltion include, for 15 exam~le~ ~roup I metal hal:ide~, e.g., 80dium, pota~siwm, li~chium with cuprou~ halide~ , e . g O, chloride , bromide , iodide; hindered phenol~; hydroqui~one~; ~d ~rarieties oî
cituted member~ c~ tho~e groups and cosnbinatis~
thereof P

The mo~of ilament of the pre~ent in~re~tion may be prepared by coIlventio~al pol~er melt-blending technigues that blend or mix the con~tituent~ to fo~m a uniform di~per~io~. All of the con~tituent~ may ~e mixed 25 ~imulta~eou~ly or separately utilizi~g mixi~g . means well know~ in the art, such a3 a mixer or extnlder. The mono~ilament~ can be produced by a conti~ll~us or multi-step proce~s. Olle of ~uitable method~ for producislg the pre~en~
monof ilame~t i~ ~he traditio~al two- 8'cap method, which .... .
30 me'chod com~ri~e~ mel'c-k~eadin~ a pre~lou8ly~ dry-blended co~o~ition further in a heated ex~r~der provided with a single-~crew, or in ~che alte:rnative, a plurality of . crew, extrudi~g the u~if orm compo~ition into ~trand~ hoppi~g th@ extruded ~txa~d~ i~to pellet5, and ~ubse~uently mel'c~
3 5 extruding the pellet~ in an extruder eguipped with a WO g3/13251 2 1 2 ~ 7 9 3 Pcr/US92/10734 monofilament die to form monofilament3. I~ an alternative, the dry-blended ~onstituent~ of the compo3ition is provided to a mo~of ilamerlt forming apparatu~ which compri~es a hea~ed extruder having at least a ~ingle 3crew. The heated 5 extruder melt-blends the monofilament compo~ition, and the resulting melted and thoroughly ble~ded mo~o:filament compo~ition i~ fed into a metering pum~ which force~ the mPlted composition thxough a die to from mel~ed monofilame~t~. l~e melted mo~o~ilament ar~? quenched i~ a 10 waterbal:h ~o a~ to form solid monofilament~. Th~ latter continuous method i8 preiEerred since it pr~Yides an overall reduction of proce~ and ha~dliTlg step~ neces~ary to f orm a u3eful monofil~ent . ~e re~ultiny monofil ament i~
sub~equently draw~ or stretch orie~ted to impar~ p~rysical strength. Typical drawin~ proce~e~ c~mpri~e one or more cycle of heating the mo~ofilament to a t ~ erature near it~ ~ofte~ing poi~t a~d the~ ~tretchi~g the ~fte~d mo~ofilamen to a draw rat;io of from ~bout 2:1 to ~bout 6:i, pref~rably from about 3:1 to ~bout 5:1. The drawn mo~ofilame~t i~ que~hed and the~ B~bj e~ted to a relaxing procedure, which compri3e~ reheati~g the draw~
mono~ilame~t, allow1ng it to relax up to about 15 ~ a~d quenchin~ to $orm the fini~hed monofilament.

The re~ulting mo~ofilament can be fab~icated into differe~t i~du~trial conveyer bel~s of ~ariou de~ign~ and uses~ For example, the monofilament can be fabricated i~o the fel~ for u~e in papermaklng ~achi~e~. Numerous dP~ign for ~uch felt~ are well ~ncwn i~ the artj which include UOS.P 3,613,258 o ~amie~on et al., U~S.P.
4,~19r753 to Sn~art~ U.S.P. 4,427,734 to Joh~on, U.S.P.
4,973,512 to Sta~ley et alO, and U.S.P. 4,995,429 to Ko~itzke. ~el ~abricated from the monofilament of ~he present invention pro~ides dimen~io~al stability, abra~io~
a~d chemical re~i t~nce~, resiliency, and tenacity, making WO 93/13251 PCr/U~92/1(~734 the felt ~uitable for u3e in papermaking machines. The - felt~ of the in~tarlt invention i~ parti~ularly suitable a~
a pre~ felt for the wet-press ~ection o~ pape~making m~chine~. In additloIl, the ixlstant fel'cs exhibi~c a high 5 thermal ~ta~ility, rendering the felt sui~able for u3e in the dryer sectiorl of papermaking xnachi~e~ aY well as in other con~reyer belt application~ where the belt i~ e~o~ed to harsh telr~erature and chemical enlrironment~.

~0The pr~sent i~ve~'cion i more fully illuqtrated by th~
fs:~llowi:clg ~ ple, which i~ giverl by way of illu tratio and not by way of limi~:ation.

Poly(2,6-dimethyl-l,4~ph@~ylene ether) havi~g O.Sl intri~iG ~i~co~ity wa~ i~timately ble~ded ~ith ~lo~ 6, fumaric acid, a ma~eated ethyle~e/propyle~e rubber, a~d N-bromo~ucci~imide ak a weight ratio o~ 47.75:47:5:0.5:0.05~respectively. A ~ylon 6 r~in having a fonmic acid ~i~co~ity of ahout 58 and a molecular weight of about 25,000 wa~ employed, which i~ a~ailable from Aliied-Signal Inc. The s leated ethylene/propyle~e rub~er u3ed i~
available from Exxo~ Chemical under the trademark Bxelor~
l803, which rubber co~tains fro~ 0.5 to 0.9 weight % of maleic anhydride. The blended compo~ition was extruded in a Wer~er & Pfl eiderer ZSK 40 ~rml twi~ screw extruder equipped with nine separately heated barrel zo~es and o~e 30 die. me extruder temperature pro~ile wa3 240C for zo~e 1, 280C for zo~e~ 2-5, 260C for zone 6-9, a~d the die wa~ kept at 275C. The extruder pre~sure wa~ 6.89 ~Pa ~1000 p~i). me resultin~ polyphenylene ether/polyamide blerld compo~itioxl was pellet ized .

W~9~ 251 PCT/US92/10734 2:L23793 Sub~equently, the polyphenylene ether/polyamide pellet was extruded in a single ~crew extruder, ha~in~ three zone~, equipped with a monofilament die. The temperature profile wa~ 264C for zone 1, 26~C for zones 2-3 and 266~C
for the die. The re~ulting continuou~ monofllament wa~
quenched i~ a waterbath then ~ub~ected ~o a s~re~ch orienta~io~ proces~. The orientation proces~ con~i~ted o~
drawing and relaxing procedure~. The drawing procedure wa~
acco~ hed by pa~3i~g the monofilame~t through a tension 10 roll a~se~ly (ten~ioll godet) oper~ted at: 20 met@~rs per minute ~MPM), an o~re~ heated to 177C, a draw roll pre~
a~3~embly (draw godet) operated at 61 MPM, arl oven heated to 221C, and a draw roll pre~s a~ ly operated at 63 MPM, in ~equence. The re~ulting draw~ monofilament was ~ubjected to a relaxi~g prc)cedure by pa8~ing i~ through an ~ren heated to 229C a~d a relax xoll pres~ operated a~ 58 MPDq. ~e reRulti~g mo~o~:ilame~t. wa~ o~iented to a draw ratio of 4:1 a~d had a diameter of O.û2 cm ~0.008 inche~

The hreaking tenacity of the m~nofilamen~, measured in accorda~ce with the ASTM D2256-90 ~e~ti~g procedure, wa~
3.5 gram/denier ! i~dicating that the polyphenylene ether/polyamide mo~ofilament compo~ition of the pre~ent iIlYention i~ a highly comp~tible blend composition that ha~
a go~d ph~ ical ~trength a~d that the resulting monofilament i~ an excellent m~nofilament u~eful for variou~ indu~trial conveyer bel applications, e~pecially for the papermaking machine felt appllcatio~.

.. . :
The terlsile modulus of the moIlofilarnent wa~ measured, according to the AST~ DB~5-85 te~ting pro~e~ure at 70F and 6S~6 relati~re humidity, o~ the dry-a~-extruded and wet-colldition d monof ilament ~ample~ ~ The wet - conditio2~ed sample~ were prepared by ~ubm~rgirlg the mollof il~men~
sample~ in a waterbath at room temperature for ~raried WO 93~13251 PCI/U~;~2/10734 - 19 - :

dura~ion~. The result~ are shown in Table 1 below.

T~le 1 Sa~pl~/C~onditio~ T~ll~ ~o~lulu~
( grarn/denier) Dry-A~ xtrud~do 32.1 Wet - Co~dition~d:
2 hour3 2 6 O 8 24 hour~ 2~ . 5 4 8 hour~ 2 6 . 7 ~:

A~ can be ~een fr~m the abo~re, the te~ e modulus sf the m~rlof ilamerlt of the pre~ent in~ention doe~ not cha~ge af ter the iIlitial drop e~e~ when the mo~o~ilamen~
su~merged i~ water: for a~ extended duration. Thi~
u~expec~ed advarltage of th~ i~9~a~ monofila~s~ent ~ ce ~h~
25 high conte~t of nylon in tbe com~?o iti~on ~was e~pected to render the monofil~mellt to be highly moisture ~e~3itive and the amount of moi~'cure ab~orbed by the monof ilamen~c to be proportional: to:~the: duration of e~po~ure to moi~ture.

l'he mono~ilamen~9 fo~ xample~ 2-lL were :prepared i~
accorda~ce with the procedure~ outlined` in Ex~unp:~e~ ~ 1 utilizing the component~ li3ted in Table ~ : The monof ilament were drawn to ~reral of draw ~a io and 35 teste~- for their t~acity. The re~ult: are ~howIl in Table 2. :

;

WO 93~132Sl ~ PCI /US92/10734 ~12~7J~~ 20 -~ O .~
o o ~J In In ~r I ~DO I ~0 1 1 1 . rl V
~1 ~
V .~ -.
Ul U) D .,~
~: ' , ~ ,~, o , , , , ~ o o o o . ' U~
~D I o ~ ~0 ~ V O ~ -.
~:: 00 .~ '~
'S ~

X~ o R R r ~ . ~
~ ~ 7 t~
~ X o~ It') ~ U7 0~ ,~
;~ P3 ~ ~ ~ o O 0 ~ , ~ ~ ~ ~ ~
~ O S~î ~'7~
X ~ a~ 7 1 1 ,~,~ O ~ i W ~ 7X~ ~
: ~ :
O ~ 7 ~ O~ 7 0 ~ - . - . ,_~ ,,7 C~
li3 ~ W ~ ~ ~ d' ~ ~ o a 1~1 ~ d7 ~ ~ '~

~ : : ~
Xcn In I m o ~ . . a) ~
~ ~ ~ n ~7 ~ 'm ~
,,,,. .~ ..

B CD O ~ O ~ U~ O ~
W P~ ,1 ,J ~ ~ rd C~ ~ U~ ~D ~ t` CD ~D
P ~ ~5 Z ~ ~ ) 7 W(~ 93~132S1 2 1 2 3 7 9 3 PCr/USg2/10734 The results in Table 2 indicate ~hat the tenacity o~
the monofilaments incre~eR a~ the vi~co~itie~ of polyamide and polypheIlylene ether in~rea~e.

A~ di~cus~ed before and can be seen from the abo~ve example3, the instant monofilament offers dimen~ional ~tability, abra~ion re~i~tance, chemical ~e~istance, hydroly~i~ resi~taIlce arld high 'c~erature stabili'cy a~
well as 8 re~gth and tenac:ity, r~deriIlg the mollofilament to be a~ exs~ell~rl'c pc~ ric: material for u in 1:~du~trial conYeyex belt applicatio~, espe~ially where ~che l~elt i~
exposed to chemically and thermally har~h emrirorments, ~uch a~ ~he felt~ for papermaking machine~.

..

Claims (10)

What is claimed is:

1. A monofilament comprising, based on the total weight of the monofilament:
(a) from about 10 weight % to about 60 weight % of a fintionalized polyphenylene ether;
(b) from about 40 weight % to about 90 weight % of a polyamide; and (c) from about 1 weight % to about 30 weight % of a functionalized elastomeric polymer, wherein said monofilament exhibits a tenacity of at least 3 gram per denier as measured in accordance with the ASTM D2256-90 breaking tenacity testing procedure.

2. The monofilament according to claim 1, wherein said polyphenylene ether is selected from the group consisting of poly(2,6-dimethyl-1,4-phenylene ether), poly (2-methyl-1,4-phenylene ether), poly (3-methyl-1,4 -phenylene ether), poly(2,6-diethyl-1,4-phenylene ether), poly (2,6-dipropyl-1,4-phenylene ether), poly(2-methyl-6-alkyl -1,4-phenylene ether), poly(2,6-dichloromethyl-1,4-phenylene ether), poly(2,3,6-trimethyl-1,4-phenylene ether), poly (2,3,5,6-tetramethyl-1,4-phenylene ether), poly(2,6-dichloro-1,4-phenylene ether), poly(2,6-diphenyl-1,4-phenylene ether), poly(2,5-dimethyl-1,4-phenylene ether), and blends and copolymers thereof.

3. The monofilament according to claim 1, wherein said polyphenylene ether is functionalized with a functionalizing compound having a carbon-carbon double bond or triple bond and a functional group selected from the group consisting of carboxylic acids, anhydrides, glycidyl functionalities, and mixtures thereof.

4. The monofilament according to claim 1, wherein said polyamide is selected from the group consisting of nylon 6, nylon 6,6, and blends and copolymers thereof.

5. The monofilament according to claim 1, wherein said polyphenylene ether has an inherent viscosity between about 0.3 dl/g and about 0.8 dl/g and said polyamide has a reduced viscosity between about 1 dl/g to about 4 dl/g.

6. The monofilament according to claim 1, wherein said functionalized elastomeric polymer is selected from the group consisting of olefinic elastomers, styrenic block copolymers, core/shell rubbers, and mixture thereof.

7. The monofilament according to claim 1, wherein said functionalized elastomeric polymer contains, based on the total weight of said elastomeric polymer, from about 0.05 wt% to about 5 wt% of a functional moiety selected from the group consisting of .alpha.,.beta.-ethylenically unsaturated dicarboxylic acids having from 4 to 8 carbon atoms and derivatives thereof.

8. The monofilament according to claim 1, wherein said functionalized elastomeric polymer comprises from about 1.5 wt% to about 10 wt% of said funtionalized elastomeric polymer.

9. A felt formed from the monofilament according to claim 1.

10. A papermaking machine felt formed from the monofilament according to claim 1.