Note: Descriptions are shown in the official language in which they were submitted.
2~2~6
A~ ~cLL~l~nAr ~ J ~ J ' ~ V ~ .L~
. ~"
Tack-free, Highly Elastic Mono- and Mul~i-fil
Polyester/Polyurethane Elastomer Filaments,
a Process for the Preparation Thereof by Melt Spinning
and the Use Th~reof
.
The invention rela~es to tack-free, hi~hly elastic mono- and multi-fil polyester/poly-
urethane elastomer filaments, also referred to below as PES-PU filaments, which
are manufactured by spinning ~ melt of a partially crosslinked thermoplastic
polyurathane, also referred to below as rPU, which is obtainabla by reacting
a) at least ona organic diisocyanate with
b) at least one polyester-diol having a molecular weight of from 500 to 5900
preferably prepared by polycondensa~ion of at least one dicarboxylic acid and
.0 at least one alkanediol and/or alkylene glycol, by polycondensation of at least
one ~-hydroxycarboxylic acid or by polymerization of at least one b~-lactone,
.. ... ....
c) at least one difunctional hydroxyl ~roup containing chain ex~ender having a
molecular weight of from 62 to 380, and
- 16
d) at least one at least trifunctional hydroxyl group-containing crosslinking
a~ent,
to a process for the preparation thereof by the melt spinning procsss and to the20 use thereo~ for the preparation of fibers and textile flatware.
The method of preparing polyurethane(PU) filaments frorn PU elastomers based on
or~anlc diisocyanates, high molecular welght dihydroxy compounds and low
molecular wei~ht chain sxtenders, such as alkanediols and/or diamines, is weil
known. The ~las1~meric prop~rties of thss0 polyurethanes are ~ov~rn~d by the
antropy elastici~ resulting ~rom the segment or block structure, ie by a specific
arrang3ment of the so-called hard and soft phas0s. I~ is Influenced by th~ starting
materials used, the synthesis proccss, the spinning process ~nd the a~er-
treatment.
....
Since the urea structures formsd from diamines decompos0 on mel~ing, it is net
possible ~o spin such PU elastomers by the economical and environmentally
acceptable m~lt spinnin~ procBss. The formation of the filaments takes plac~, ~or
.
` 21219~ ~
~ .n~ o.~.ooSO/~14UY:~
. _
example, in the wet spinnin~ process by coagulation of ths dissolved polyurethan0
in non-dissolving, usually aqueous precipitation baths and in the reactive spinning
process by a combination of the chain extension of an NCO prspolyrner by means
of a diamine and the simultaneous formation o~ the filaments in ths spinning bath.
Although PU elastom0rs which are free from urea structures and which are based
on hi~her and lower molecular weight dihydroxy compounds are melt spinnable,
their d0flection temperature under load is too low, and this has a detrimental
influence on the spinning process, for exampla, on account of the marked tendency
of such an elastomer to adhere to itself, and on the subsequent textile prccessing,
.0 for example, thermosatting, dyein~, washin~ and ironing. Thus melt extrusion,which is accepted to be the most rational spinning technique, cannot be used forTPU (Kunststoff-Handbuch, Vol. 7, Polyurethanes, 2nd Edition, 1983, pp. 611-627,edited by Dr. G. Oertel, Carl llanser-Verlag, Munich, Vienna).
15 Previous proposals for avoiding tackiness include, for example, a special method
of quenching the spun filaments, the use of anti-tack agents and the use of tris(2-
hydroxyethyl)isocyanur~te in the spinning process. But these measures have not
been able to provide a satisfactory solution to this prnblem. ~ -
. ;.
20 For this reason, DE-A 2,204,470 (CA-A 999,394) describes a method of reducingtackinsss of continuously extruded PU fllaments which involves the incorpcrationof polyimide groups in the polyurethane chain or subsequently adding polyimides to
the polyurethane melt. The PU-filaments made from the resulting polyurethane
compositions must howsver be wound up at a very slow speed and orientated in a
21 second operation, so ~hat the productivity is inadequate and the process is
uneconomical. Another disadvantage is that the addition of additives causes a
reduction of the rnolecular weight of ths polyTer, this being accompanied by
lowering of the ~usion viscosity, which on the othar hand has a negativ~ influence
on the elastic properties, the percentage elollgation at break, and tha tenacity o~
t~ierssultingyarn.
DE-A 1,944,507 (GB-A 1,245,311 ) discloses a multistage process, which
rcduces tha tackiness of PU-filaments in the melt spinning process. In this
process, melt extrusion i~ carried ou~ in the first s~ep, and the resulting nlament is
~5 stabilized by quenching, whilst in the second step it is orienta~ed by at least 30 %
and is relaxed in a further step by at least 50 % prior to take-up. The dasign o~ ~he
process indicates that the haul-off go~et carries the finished, completely cooled
PU filament. This shows the typical properties ~f a PU-Elastomer, tha~ is to say, it
can no longer be orientated in the true sense but can, on account of its high
elasticity, be str~tched to a ~reat extent, ~his elongation being reversible.
_ 2
2 l 21 ~ 9 6 o z.~oso/44D95
According to W0 88/04703, the tackiness of the PU-filaments with respect to
each other and of the ~ibrils with respect to aach other can be avoided and
- filaments having a high modulus and improved processing properties can be
manufactured if the polyurethan~ and the orientation conditions are such that
. irreversible orisntation takes plac~ and no use is made of a relaxation stag~ and
the haul-off spssd is additionally increased. Using this process, It is possible to
process lPU having a softening temperature between 180 ~nd 230C, a
hardness of from 80 to 95 Shore A and a density of from 11 to 125g/cm3 . In
particular, the hardness of the lPU is an important factor governing the tackiness
of th~ PU filament. Drawbacks of this method comprise the low elas~icity of the
resulting PU filament and the complicated spinning process.
Tack-frea PU-filaments obtainabie by melt spinning can be produced, according toDE-A 3,911,725, from lPU containing plasticizers. A drawback of these PU-
16 filaments, which have a high tensile strength at break, a low set p~int and a highresilience, is at best their tendency toward migration of the plasticizer under
certain r~action canditions in subsequent processing.
Further, PU elastomers which can be process0d thermoplastically and which are
20 capable of being proc~sssd inter alia by melt spinning to form elastomer fibers,
can accordinQ to DE-A 3,233,384 (US-A 4,442,281) be manufactured by
polyaddition of substantially pure ~rans-cyclohexane-1,4-diisocyanate, diols having
a molecular weight of from 80~ to 4000 and bisethoxylated bisphenol A or
mixtures of bisethoxylated bisphenol A and oth0r short-chain diols actin~ as chain
25 ext~nders. A drawback of this lPU is th~ rslatively difficult and Uhus expensiv~
preparation of the starting component trans-cyclohexan0-1,4-diisocyanate and therelatively iow deflection temp~rature under load o~ the lPU, which hinders after-
treatrnent of the ~ibers in textile applications, for example, dyein~, thermosetting,
etc ~t elevated temperatures or may ev~n render such processing impossible.
It Ts an object of the presen~ invention to overcoms the aforemsntioned drawbacks
entirely or at least partially and to provide a simplified, improved process for ~h0
preparation of tack-free, highly elas~ic, mono- and multi-fil PU-fllamen~s by mel~
spinnin~ of TPU. A useful TPU for this purpos~ should have a hi~h deflection
temperature und0r load, be melt spinnable and be basad on commercially availableand thus inexpsnsive starting compon0nts. The filamsnts formed ~rom this TPU
should bs tack-fr3e and highly ~lastic and should be charactsrized by good
- processabili~ in subsequent textile applicaUons.
~ It has besn possibl~ to achiev~ this obj~ct, surprisin~ly, by tha use of a special
._ - 3
21 2~6
.. .. .....
partially crosslinked TPU based on polyester diols.
Thus the invention relates to tack-free, highly elastic mono- snd multi-fil
polyester/polyurethane elastomer filaments manufactured by spinning a melt of a
partially crosslinked lPU, which is obtainabla by the reaction of :
a) at least one organic, preferably aromatic, diisocyanate with ~`
b) at least one polyester diol having a molecular weight of from 500 to 5000,
tD
c) at least on~ difunctional hydroxyl group-containing chain ex~ender having a
molecular weight of from 62 to 380 and
d) at least on~ at l~ast trifunctional hydroxyl ~roup-con~ainin~ crosslinking
15 agent.
The invention further relates to a process for the preparation of said tack-free,
highly elastic mono- and multi-fil PES-PU filaments by m~lt spinning ~he partially
crosslinked ~PU as defined in claim 12, which partially crosslinked TPU is
20 preferably preparsd by the on~-shot proceæ, and ~o the us~ of the tack-free,
highly elastic mono- and multi-fil PES-PU filaments of the invention for the
prcparation of ~extile fibers, t~xtile flatware, and technical ffbars as definsd in claim
1 5.
2~ By the addition of at loast trifunctional, pre~erably trifunctional hydroxyl group~
containing crosslinking agents the deflection temperature under load of the TPU
can be raised without adversely influencing ~he spinnability of the TPU melt.
The PES-PU filaments prepared from the par~ially crcsslinked ~PU by melt
w spinnin~ are superior to PU-filaments obtained from uncrosslinked TPU in that they
havs improved tensile strength at break whils~ their elongation ~t break is at 7sast
~s ~ood as, and in many cases bener ~han, that of ~h~ latt~r. A particular
advantag~ is tha~ the PES-PU filaments of the invention can b~ sasily wound up in
a tack-free condition on accoun~ of th~ hi~her tack t~mperaturc of ~he partiallyas crosslinked TPU and consequently have ~ood processing prop~rties for subsequ0nt
textile applications. Ths PES-PU fllam~nts of the inv~ntion are highly elastic.
The following detailed description r31atss to ~h~ preparaUon of the partially
crosslinked TPU suitable for us~ in the invention and ~e relevan~ starting
compon~nts and to the preparation o~ th~ tack-free, highly elastic mono- and multi-
_ -- - 4
. .,:
`" ` 2~21~96
DJ~ rA~ ENGESELLSCHAFT OZ ooso/44~95
fil PES-PU filaments:
a) Suitable organic diisocyanates (a) are, ~or exampie, aliphatic, cycloaliphatic
and prefsrably aromatic diisocyanates. Specific examples th0reof are:
6 aliphatic diisocyanates advantageously having from 4 to not more than 12
c atoms in the alkylene radical, such as hexamethylene diisecyanate, cyclo-
aliphatic diisocyanates, such as isophorone diisocyanate, 1-methyl-2,4- and
1-methyl-2,6-cyclohexane diisocyanates and the correspondin~ isomer mix-
tures, 4,4'-, 2,4'- and 2,2'-dicyclohexylmethane dicyanates and the corres-
ponding isom0r mixtures and preferably aromatic diisocyanates, such as 2,4-
toluylene diisocyanate, mixtures of 2,4- and 2,6-toluylene diisocyanates, 4,4'-
2,4'- ~nd 2,2'-diphenylmethane diisocyanates, mixtures of 2,4'- and 4,4'-
diphenylmethane diisocyanates and 4,4'-diisocyanato-dipheny.ethan-(1.2). It
is preferred to use 1,6-hexamethylene diisocyanat~, isophorone diisocyanate,
diphenylmethane diisocyanate isomer mixtures having a 4,4'-diphenyl-
methane diisocyana~e con~ent o~ mora than 9wt% and in particular 4,4'-
diphenylmethane diisocyanate. -~
b) Suitable polyester diols (b) having a molecular weigh~ ~ from 500 to 5000,
praferably of from 800 to 3200 and more preferably of from 1 5D0 to 2500
are polycondensation polymers, which can be manufactured by polycondensa-
tion o~ dicarboxylic acids having from 2 to 12 c a~oms, preferably
alkanedicarboxylic acids having from 2 to 12 Catoms, in parlicular from 4 to
6 C atoms or mixtures of alkanedicarboxylic acids and aromatic dicarboxylic
2~ acids and alkanediols having ~rom 2 to 12 C~toms, preferably ~rom 2 to 6
C atoms or alkylen3 glycols havin~ from 4 to 8 c atoms, preferably from 4 to 6
c~toms or mixtures of alkanediols and alkylene glycols. The alkanediols or
~Ikylene ~Iycols may in each case bs used individually or in the form of
mi~tures. Suitable alkanedicarb~xylic acids are, for example, oxalic acid,
~D succinic acid, ~lutaric acid, pimelic acid, suberic acid, azelaic acid, selacic
acid,undecanedioic acid, dodecan0dioic acld and preferably adipic ~cid. The
oromatic dicarboxyiic ~cid which is pre~erably used is terephthalic acid.
Inst~ad of the free dicarboxylic acid it is possibl~ to use ths corrssponding
dicarboxylic acid derlvatives, su~h as mono- and/ordi-es~ers o~dicarboxylic
5 acids with alcohols having ~rom 1 ~o 4 carbon ~toms or dicarboxylic acid
~nhydrides. Examples of alkanediols or alkylene 01ycols are: a~hanediol,
diethylene ~Iycol, 1,2- or 1,3-propanediol, dipropylene ~Iycol, 1,4-butanediol,
1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,~-octanediol, 1,9-non-
anediol, 1,1 O-decanediGI, 1,1 2-dodecanediol, 2,2-dimethyl-~ ,3-propanediol,
2,3-butanediol, 2,~-hexanediol, 2,5-dimethyl-2,5-hexanediol and 2,q,4- or
2,2,4-trimethyl-1,6-hexanediol. It is preferred ~o use ethanediol, diathylene
_ - 5
. ..'
~A j~KTlE~OESE.LSCHA~ 2 1 2 1 9 ~ ~ oz ooso/q4uYa
glycol, 1,4-butanediol, 2,2-dimethyl-1,3-propanediol ~neopentyl glycol), 1,5
pentanediol, 1,6-hexanediol or mixtures of at ieast two alkanediols, for
example, mixtures of 1,4-butanediol/1,6-hexanediol, n00pentyl ~Iycol/1,6-
hexanediol, ethanediol/1,4-butanediol, ethanediol/1,6-hexaneJiol and 1,4-
6 butanediol/1,5-pentanediol/1,6-hexansdiol. The polycond~nsation polymers
which are preferably used are alkanediol poiyadipates, in particular ethane-
diol polyadipates, 1,2-propanediol polyadipates, 1,4-butanediol polyadipates,
1 ,6-hexanediol polyadipates, 1 ,4-butanediol/1 ,6-hexanediol polyadipates and
neopentylglycol/1,6-hexanediol/adipic acid polyesters. ;
.0 . ,
The preparation o~ the polyester diols may b~ carried out by polycondensing
the dicarboxylic acids, preferably alkanedicarboxylic acids and/or derivatives
thereof and alkanediols and/or alkylene ~Iycols without ~hs USB of a catalyst
or, prsferably, in the presence of an esterification catalyst, advantageously
15 under a blanket of inert gas such as nitrogen, helium, argon, inter alia, in the
melt at temperatures of from 150 to 250C, prsferably from 180 to 220C,
optionally under reduced pressure, until the desired acid number is reached,
this being advantageously smaller than 10, pre~erably smaller than 2. In a -preferred embodiment, the esterifica~ion mixture is polycondensed at the
aforementioned ~emperatures until the acid number is from 80 to 30,
preferably from 40 to 30, under standard pressure and subsequen~ly under a
pressure of less than 5ûOmbar, preferably frorn 50 to 150mbar. Sui~able
esterificatiQn catalysts are, ~or example, iron, cadmiurn, cobalt, lead, zinc,
antimony, magnesium, titanium, and tin catalysts in the form of rnetals, metal
26 oxides or metal salts. Alternatively, the polycondensation may be carri~d outin the liquid phase in the presence of diluents and/or entraining a~ants such
as benzene, toiuene, xylene or chlorobenzene, to effect removal ~f the water
of condensation byazeotropic destillation.
,0 Th~ preparatisn of the polyester-diols Ts carried out by polycondensing the
organic dicarboxylic ac5ds and/or derivatives thereof and alkanediols and/or
~ikylens alycols ~dvantageously in ~ molar ratio of from 1:1 to 1:8,
praferably frorn 1:1.05 ~o 1:2.
~6 Suitable polyester diols are polycondensation polyrners prepared from ~-
hydroxycarboxylic acid having from 4 ~o 12 c~toms, pre~erably from 4 to 8
Catoms, such as 4-hydroxybutyric acid, 5-hydroxyvaleriG acid, 8-hydroxy-
caprylic acid and preferably 6-hydroxycaproic scid ~nd polymerisation
products d~rived from Id-lacton~s having from 4 to 12 Catoms, preferably
JO from 4 to 8 C atoms, such as 7-butyrolactone, ~-valerolac~on~, 8-
hydroxyoctanoic acid lactone, 1 0-hydroxydecanoic acid lactone, 1 2-hydroxy-
_ 8
:
212~96
..
dodecanoic acid lactone and preferably -caprolactone.
c) Suitable difunc~ional hydroxyl ~roup-containing chain extenders having a
molecular weight o~ from 62 to 38~, preferably of lhrom 62 to 210 are
3 preferably alkanediols having from 2 to 12 carbon atoms, pref~rably 4 and/or
6 carbon atoms, such as ethanediol, 1,3-propanediol, 1,4-butanodiol, 1,5-
pentanediol, 1,6 hexanediol, 1,7-heptanediol, 1 ,8-octanediol, 1,1 0-decan~-
diol and 1,12-dodecanediol and dialkylene glycols such es diethylerle,
dipropylen~ and dibutylene glycols.
Examples nf other suitable chain extenders are, howevsr, di-esters o~
~erephthalic acid with glycols having from 2 to 4 carbon atoms, such as
1erephthalic acid bis-ethylene ~Iycol or ter~pmhalic acid bis-1,4-butanediol
~nd hydroxyalkylana ethers of hydroquinone, such as 1,4-di(~-hydroxye~hyl)-
16 hydroquinone.
Extrem~ly good results have been achi~vsd using the following chain
extend0rs, which are therefore preferably used: 1,6-hexanediol and in
particular 1,4-butanediol or mb(tures of 1,6-hexanediol and 1,4-butanediol.
d) An ess3ntial condition for the preparation olF ~h~ partially crosslinked TPU
us0d in th~ present invention is ths use of at least one, at l~ast trHunctional
and pref6rably tri- to octa-functional but in particular ~rifunctional hydroxyl
group-containing crosslinking agent (d~. Such crosslinking sgents advantage-
25 . ously hav~ a mol~cular weight of from ~0 to 400 and pref~rably from 90 to138. E~(amples of suitable crosslinking agents are: ~Iyc~rol, ~imethylol~
propane, glycerol and/or trimethylolpropan~ alkoxyla~ed with up to 3mol of
alkylene ~xide, for example, ethylene oxida, pentaerythri~ol, sorbitol and
swrose, it b~ing particularly pr2ferr~d to use ~Iycerol or ~rim~thylolpropan~
or mixtur~s of glycerol and trim~thylolpropane.
Adjustrnent of th~ hardnsss and me7ting point of ~h~ TPU m~y be effec~ed by
varying the molar ratio of lthe components (b) to (d) ov~r a rslatively wid~
range. Extremely ~ood reul~s have been obtainsd using molar ratios of
polyester diols (b) to chain ex~enders (c) of, say, from 1:05 to 1:20,
pr~f~rably from 1 :1 to 1 :10 and mora preferably from 1 :1 to 1 :5, with the
~ddition of ~ crosslinking agent (d) in ~n amount of, s~y, from 0.01 to
10mol%, preferably from 0.3 to 5mol~b and more pr0ferably ~rom 0.5 to
~1.0 mol%, based on the molar mass of the polyester diols (b).
' ':,''
The preparation of the partially crosslinked TPU used in the present invention
- 7
.,, ~
: '
2 1 2 ~ 9 9 fi oz DDsD/44095
is eff~cted by causing reaction of the building components (a) to (d) with
each other advantagaously in such amounts that th~ equivalent ratio of NCO
groups in ~he diisocyanates (a) to the sum of th~ roups in the
polyhydroxyl compounds (b) to ~d) is from 0.9 to 1.1:1, preferably from 0.95
6 to 1.05:1 and more prefsrably from O.g8 to 1.03:1. The polyhydro~(yl
compounds ~b) to (d) are caused to react with the diisocyanate adYantageous-
ly in the form of a mixture (a).
e) The partially crosslinked TPU used in the present 3nvention are preferably
synth~siz~d in th~ absence of a catalyst (e). Depending on the na~ure of the
starting components (a) to (d) used and in particular on the reactivity thareof
it may be ~dvantageous to accelerate the reaction between th~ NOO groups in
thc diisocyanates (a~ and th~ hydroxyl groups in the components (b) to (d) by
tn~ use o~ cstalysts. Suitable catalysts are, for example, the ter~iary amines
known in the art, such as triethylamine, N,N-dimethylcyclohexylamine, N~
methylmorpholine, N,~-dimethyl- or N,~-diethyl-piparazine, tris(dime~hyl-
~minoathyl)-(s)-triazine, pentamethyldiethylene ~riamine, N,N,~,N'-te~ra-
methylbutylene diamine, N,N,~,~-tetramethyl-4,4'-diamino-dicyclohexyl-
methane, 2-(dimethylaminoethoxy)e~hanol and diazabicycle-t2.2.2]-octane
and in particular organic rnetal compounds such as titanates, iron com-
pounds, tin compounds, for example, tin diacetate, tin dioctoate, tin dilaurate,or the Un dialkyl salts of aliphatic carboxylic acids such as dibutyltin
diacstate, dibutyltin dilaurate, and mixtur~s of tertiary amines and organic
metal compounds. Th~ catalysts ar~ usually employed in amounts of from
2C 0.001 to 0.1 pa~t by weight per 100 parts by weight of the polyhydroxyl compounds (b) to (d).
f) It is possibl0 to incorporate, besides ca~alysts, other auxiliaries and/or
additives (f) in th~ building compon~nts. Examplss thereof are lubricants,
,0 inhibitors, stabilizers to hydrelysis, li~ht, heat or yellowing influances, ~or
exampl0, attack by chlorine, and flame retardants, dy~s and pi0ments.
More d~tailad information on the aforem~ntioned auxiliaries and additives ~f)
is nvailable in technical literature, ~or exampl~, in the monegraph by J.H.
~8 Saunders and K.C. Frisch, High Polymers, Vol. XVI, "Polyurethanes", Parts 1
and 2, Interscience Publishers 1962 and 1964 respectively or in DE-A
2,901,774.
The partiaily crosslink~d TPU's us0d in the present invention are preferably
prepared by the one-shot procsss. In this case, the TPU may be obtained by an
~xtruding or, pref0rably, belt spinning process involvin~ batchwis~ or continuous
_ . ,
;,, ,;; -: ~
~ ~ 2 ~ 2 1 ~ 9 6 o~z ooSo/44o95
mixing of the building components (a) to (d) and optionally (e) and/or (f), allowing
the reaction mixture to react to conclusion in the extruder or on a conveyor belt at
temperatures of from 40 to 230C, preferably from 70 to 180C, and then
~ranulating th~ resultant TPU.
I~
In the preferred belt spinning process, the building components (a) to (d) and
optionally (e) and/or (f) are continuously blended at temperatures above the
melting point of the building componen~s (a) to (d) with the aid of a mixing head.
The reaction mixture is applied to a support, preferably a conveyor belt, for
0 exampl~, of metal, and fed through an annsaling zone havin~ a length of from 1 to
20m and preferably from 4 to 10m at a speed of from 1 to 20m/min and
preferably frorn 3 to 10 m/min. The reaction temperature in the annealing zone is
from 60 to 200~C and preferably ~rom 100 to 180C. Th0 resultiny partially
crosslinked TPU can be granulated after cooling and, if desired, storsd.
1~
The tack-free, hlghly elastic mono- and multi-fil PES-PlJ filamen~s of the invention
can be manufactured by melt spinning processes known in the art. Particularly
suitable, and thus prefsrably used, equipment for such manufacture are extruder
melt spinning plants which may, if desired, be equipped with water-cooling means2D for cooling th~ freshly spun PES-PU filaments, in addition to the conventionally
employed air-cooling means involving, for ~xarnple, the use of a drop shaft (?). ?
In a preferred embodiment of the process of the invention for the preparation ofthe PES-PU filaments of the invention the lPU suitable for use in the invention is
mslted in an extruder at a tempsrature ranging from 150 to 250~C and preferablyfrom 170 ~o 230C depending on the partially crosslinked TPU used, the melt is
converted to filaments by means of a tooth~d wheel spinning pump and a spinnerethaving one or more hDles, accompanied by melt filtration, and the resulting
filamen~s are cooled by water or air depending on the haul-off speed employed
and are wound onto conventional bobbin units.
~0 :
Ths PES-PU filaments prepared by the process of ~he invention ars ~dvantage~
ously wound on~o bobbins af~er being additionally treated with a spinning dope
based on, for example, a siliconic or silicic acid dispersion, which further improves
the already substantially tack-free windin~ and unwindin~ proper~ies of the
fllaments when wound onto and off from the spinning bobbin and thus further
improves the ease of subsequent processing of ~he mono and multi-fil PES-PU
filaments.
Such spinning dopes are well-known commercial produc~s. Suitable spinning
dopes based on polysiloxane elastomers or mixtures of polysiloxanes and a silicon
. .. ~
Dr ~rAKTIEN(~5ELLSCH~Fr o.Z.DDCD/44095
cornpound are, for example, marketed under the registered trade marks Siligen(~
SiP, Siligen~D MSI and Siligen~ ESI and ona based ~n silicic acid esters is
available, for example, under the registered trade mark Siligen(~)E (BASF : .
Aktiengesellschaft). : ~
:
Melt spinning can be carried out using nozles of conventional capillary geometry.
Advantageously however, melt spinning is eff~cted using nozles of a specific
capillary geometry, ie one in which the length is ~dvantageously from 1 D to 5D
and th~ capillary diameter is from 0.0~ to ~ mm, where capillary diameters of from
lD 0.1 to 0.5 mm ate particulalrly preferred in the case of rnultifilaments and capillary
diameters of frorn 0.5 to 2mm in the case of monofilaments, since by these
measures th0 mechanical properties of the PES-PU filam~nts of the invention can
receive additional lasting improvernent and in particular PES-PU filaments having
very good resilience and elongation at break can be obtained.
The PES-PU filaments of the invention ie the PES-PU filaments prepared by the
process of the invention do not stick together and neither do the individual fibrils of
the multifilaments~ and the filaments have a high tensile strength at break and an
elongation at break, as measured according to D~N 53,815, of more than 300 ~,
:~D preferably from 380 to 800~ and a low set point and a high resilience (DIN
53,835). Th0 elongation ratio, defined as the quotient of elastic elDngation ED and
total elongation Eges. (DIN 53,835), is greater than 0.8 and is preferably ~rom
û.85 to 0.9~
26 The textile properties of the PES-PU filaments of the invention, in particular with
regard to their resilience, tensile strength at break and elongation at break, may be
further irnproved, if desired, by a tharmal after-treatment, for example, by
annealing at temperatllres ranging from 50 to 1 70C and preferably from 75 to1 30C in air or in an atmosphere of steam or, ~or example, by h~t re-oriantation
0 using, for ex~mple, a filament t~nsion of advantageously from 0.05 to 0.2 cN/dtex.
On account of the high denection ~emperature under ioad of th~ partiaily
¢rosslinked lPU us~d in the process of the invsntion and as a result of i$s tack-
frea properties as regards winding and unwinding thereof onto and from the
J5 spinning bobbin, the PES-PU filaments of tile inven~ion ~ive advantageous results
when subJected to subsequent processing in textile applic~tions, such as dyeing
and thermosetting.
'
The tack-free, highly elastic mono- and multi-fil PES-PU filaments of the inven~ion
40 can be used for the preparation of technical fib~rs and textil~ fibers and flat
articles made from technical fibers or textile ~Ibers.
2~2~ 9~
~n~r l O.Z.00~0/4JIUY:~
Exampl~s
Examples 1 to 3 and Comparative Examples A and B
5 Genaral manu~acturing instructions: ~ ;
The preparation of the partially crosslinked TPU was carried out by tha one-shotprocess.
10 A mixture of polyester dioi and trimethylolpropane was degassed ovsr a pariod of
one hour at a temperature of 11 0C and a pressur~ of 5 mbar. The 1 ,4-butanediol
was stirred into th~ mixture and the resulting clsar solution was h~ated to 70C,
and subs~quently the 4,4'-diphenylmethan~ diisocyanat0 (heated at 65C) was
added with vigorous stirring (1000 ~pm).
After a reaction temperature of 120C had been reached, the homogeneous
reaction mixture was peured onto a hotplate heated at 125C and lined with
teflonized glass fiber cloth and having the dimensions 550 x 380 mm.
2D Following a reaction time of approximately 2 min, the resulting hot TPLI was broken
up into cearse pieces and annealed in a drying cabinet over a period of 15h at
1 00C. Following cooling to room temperature, the product was p~ssed through a
chopping mill to provid~ lPU-granules having a grain size ranging behveen 4 and
6 mm, which were then stored or, alternatively, immediately spun into filaments by
26 am01~spinningtechnique.
Prepara~ion of multifil PES-PU fllaments
.. . , ~
~he TPU thus prepared was then spun using extruder spinniny equipment having
.0 ~he following technical data~
extruder screw diameter: 25 mm,
:
extruderscrewlength: 25D,
~. . .
spinn~ret: 30 holes having a capillary diams~r of 0,3 ~n ~nd a capillatiy length of ~ :
0.6 mm, and
throughput: 1.2 kg/~, . .: -
- 11 `.
,t'' ~ t,
9 ~
. ~
the melt temperature being 220C and the spinning rate 450m/n~in with the --
application of a spinning dope based on polysiloxane (Siligen) MSI (BASF
Ak~iengesellschap) and air-cooling of the freshly spun PES-PU fîlaments.
The filaments, which were capable of being wound onto bobbins without sticking, .
wers subsequently after-treated for ~ p~riod of 10 n~in WiUl air having a
temperature of 1 00C.
Ths buildin3 components used to prepare tha TPU and the quantities thareof are
listed in Table I below, their names being abbreviat~d as follows~
.~ ... ~-
MDI: ~,4'-diphenylmethanediisocyanate, ~ i
BuOH: 1 ,4-butanediol,
TMP: trimethylolpropane, ::
PES: linear polyester diol having a molecular weight ef 2000, prepared by
polycondensation of adipic acid with a mixtur0 of 1,4-butanediol and 1,6-
hexanediol in a molar ratio of 2:1.
CAPA 223: linsar polyester diol having terminal primary hydroxyl groups and a
molecular weight of 2000, prepared from caprolactona (CAPA(E~) 223 ~Solvay ` :
lnterox). ; ~
~ '~
CAPA 212: linear polyester diol having terminal primary hydroxyl groups and a ~ ~:
molecular wei~ht of 1000, prepared from caprolactone ~CAPA~ 212 (Solva~
In~erox).
The PES-PU filaments thus prepared were found to have the mechanical :~
properties listed in Table II below.
12
1 9 9 6
.n~r I . O ~ oO50/44095
Table I
rPU Prepared by the One-shot Method
. ~
. E~ MDI Poiyester dlol BuOH Cro~;siinklng agent
Quantlty i~isrn~ Quantlty Quantlty Narne Quantlty
650.0g (2.60mol) PES 1500g tO;i6mol) 159.0g (1.76mol) TNP 3.0g (0.022mol)
2 722.9g (2.89mol) CAi'A-223 1500g (0.75mol) 187.5g (2.08mol) llHP 1.5g (O.Ol imol)
3 913.5g (3.65mol) CAi'A-212 1500g (1.50mol) 187.5g (2.08mol) TMP 1.4g (0.01 mol)
... _ . _ _ . .. .. _
o Cornparative i xarnples:
A ~09.5g (3.36mol) CAPA-212 1500g (1.50mol) 187.5g ~2.08mol)
i3 641.5g (2.56mol) ~ES 1500~ (0.76mol) 159 g (1.76mol) :~
..... . . .. _ . . . . _
Tabl~
16
Mechanical Properties of PES-PU Filam~n~s Prepared by M~lt Spinning th~ TPU
Synthesized as Described in Examples 1 to 3 and ~omparative Examples A and B ..
PES--PiJ Tit~r Tensiie Stren~th at Break Eiongatlon at 3reak Re~;ilbnce~ Ta~k Tern,oeraturc
~orn i~(DIN 53,815) (DIN 53,815) (DIN 53,835) C
1 521/30dtex0.8 cN/dtex 448~o 0.90 175
2 586/30dtex1.1 cN/dtex 399% 0.89 185
3 618/30dtex0.9 cN/dtex 394~o 0.89 165 i
.... ~
Comparative E~samples~
A 609/30dtex0.8 cN/dtex 414% 0.88 155
26 13 1514/30dtex0.6 cN/dtex 4 i7% 0.90 170
.. _ _ .. __ . _ .. _ _ . . ..
~elongation ratlo ;~ ~
. .~;
~' ~
..._._ .. . _ . . ~_ _
13
