U.S. patent application number 10/733528 was filed with the patent office on 2004-08-05 for process for the production of polyurethane urea fibers by including a combination of polydimethylsiloxane, alkoxylated polydimethylsiloxane and a fatty acid salt in the spinning solution.
This patent application is currently assigned to Bayer Faser GmbH. Invention is credited to Hutte, Stephan.
Application Number | 20040150134 10/733528 |
Document ID | / |
Family ID | 32336335 |
Filed Date | 2004-08-05 |
United States Patent
Application |
20040150134 |
Kind Code |
A1 |
Hutte, Stephan |
August 5, 2004 |
Process for the production of polyurethane urea fibers by including
a combination of polydimethylsiloxane, alkoxylated
polydimethylsiloxane and a fatty acid salt in the spinning
solution
Abstract
Polyurethane urea fibers produced by a dry or wet spinning
process and comprising, in finely dispersed or dissolved form, a
mixture of polydimethylsiloxane, alkoxylated polydimethylsiloxane
and a fatty acid salt; and a process for their production.
Inventors: |
Hutte, Stephan; (Leverkusen,
DE) |
Correspondence
Address: |
Norris, McLaughlin & Marcus P.A.
30th Floor
220 East 42nd Street
New York
NY
10017
US
|
Assignee: |
Bayer Faser GmbH
Dormagen
DE
|
Family ID: |
32336335 |
Appl. No.: |
10/733528 |
Filed: |
December 11, 2003 |
Current U.S.
Class: |
264/211 |
Current CPC
Class: |
D01F 6/70 20130101; D01F
1/10 20130101 |
Class at
Publication: |
264/211 |
International
Class: |
D01F 001/02 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 16, 2002 |
DE |
10258587.3 |
Claims
1. Process for the production of polyurethane urea fibers by the
dry spinning or wet spinning process, which comprises preparing a
polyurethane urea spinning solution, spinning the spinning solution
using a spinneret, forming threads beneath the spinneret by
removing the spinning solvent either by drying or in a
precipitation bath, finishing and optionally twisting and winding
the spun fibers, wherein, prior to spinning B) from 0.1 to 5 wt. %
polydimethylsiloxane having a viscosity of from 2 to 20 cSt
(25.degree. C.), C) from 0.1 to 5 wt. % alkoxylated
polydimethylsiloxane (PDMS) corresponding to the general formula
(1) 3wherein PE is the monovalent radical
--CH.sub.2--CH.sub.2--CH.sub.2--O(e- o.sub.v/po.sub.w).sub.mZ,
wherein eo=ethylene oxide, po=propylene oxide and Z is either
hydrogen or a C.sub.1-C.sub.6-alkyl radical, v and w are integers
greater than or equal to 0, wherein v and w are not simultaneously
0, x, y and m are integers greater than or equal to 1, which are
preferably so selected that the number average molecular weight of
the compound of formula (1) does not exceed 30,000 g/mol. and the
viscosity of component C) is from 10 to 5000 cSt (25.degree. C.),
and D) from 0.01 to 3.0 wt. % of a metal salt of a saturated or
unsaturated, mono- or bi-functional C.sub.6-C.sub.30 fatty acid,
wherein the metal is a metal from the first, second or third main
group of the periodic system, or is zinc based on the weight of the
finished polyurethane urea fibers.
2. Process according to claim 1, wherein said spinning process is a
dry spinning process.
3. Process according to claim 1, wherein said amount of
polydimethylsiloxane is from 0.2 to 3 wt. %.
4. Process according to claim 3, wherein said amount of
polydimethylsiloxane is from 0.3 to 2 wt %.
5. Process according to claim 1, wherein said amount of alkoxylated
polydimethylsiloxane is from 0.2 to 3 wt. %.
6. Process according to claim 5, wherein said amount of alkoxylated
polydimethylsiloxane is from 0.3 to 2 wt. %.
7. Process according to claim 1, wherein said amount of metal salt
is from 0.05 to 2 wt. %.
8. Process according to claim 7, wherein said amount of metal salt
is from 0.1 to 1.5 wt. %.
9. Process according to claim 1, wherein the polyurethane urea
content of the spinning solution is adjusted to produce finished
polyurethane urea fibers containing from 99.7 to 65 wt. %
polyurethane urea.
10. Process according to claim 9, wherein said fibers contain 99.5
to 80 wt. % polyurethane.
11. Process according to claim 10, wherein said fibers contain 99
to 85 wt. % polyurethane.
12. Process according to claim 1, wherein components B), C) and D)
are added to the spinning solution in such amounts as will result
in a weight ratio of polydimethylsiloxane B) to alkoxylated
polydimethylsiloxane C) in the finished fibers of 2:1 to 1:2 and a
weight ratio of polydimethylsiloxane B) to fatty acid salt D) of
2:1 to 1:2.
13. Process according to claim 1, wherein the polydimethylsiloxanes
B), alkoxylated polydimethylsiloxanes C) and fatty acid salts D)
are added to the spinning solution in the form of a 10 to 25 wt. %
stock formulation solution in the spinning solvent, based on the
sum of the amounts of components B), C) and D).
14. Process according to claim 1, wherein the denier of the
finished spun fibers is from 10 to 1280 dtex.
15. Polyurethane urea fibers comprising A) from 99.7 to 65 wt. %
polyurethane urea polymer, B) from 0.1 to 5 wt. %
polydimethylsiloxane having a viscosity of from 2 to 20 cSt
(25.degree. C.), C) from 0.1 to 5 wt. % alkoxylated
polydimethylsiloxane (PDMS) corresponding to the general formula
(1) 4wherein PE is the monovalent radical
--CH.sub.2--CH.sub.2--CH.sub.2--O(eo.sub.v/po.sub.w).sub.mZ, eo
represents ethylene oxide, po represents propylene oxide and Z is
either hydrogen or a C.sub.1-C.sub.6-alkyl radical, v and w are
integers greater than or equal to 0, wherein v and w are not
simultaneously 0, x, y and m are integers greater than or equal to
1, which are preferably so selected that the number average
molecular weight of the compound of formula (1) does not exceed
30,000 g/mol. and the viscosity of component C) is from 10 to 5000
cSt (25.degree. C.), D) from 0.01 to 3 wt. % of a metal salt of a
saturated or unsaturated, mono- or bi-functional C.sub.6-C.sub.30
fatty acid, wherein the metal is a metal selected from the first,
second or third main group of the periodic system, or is zinc, and
E) from 0 to 20 wt. % additives, wherein the polydimethylsiloxane,
the alkoxylated polydimethylsiloxane and the fatty acid salt are
finely dispersed or dissolved in the fibers.
16. Polyurethane urea fibers according to claim 15, wherein said
amount of polyurethane urea polymer is from 99.5 to 80 wt. %.
17. Polyurethane urea fibers according to claim 16, wherein said
amount of polyurethane urea polymer is from 99 to 85 wt. %.
18. Polyurethane urea fibers according to claim 15, wherein said
amount of polydimethylsiloxane is from 0.2 to 3 wt. %.
19. Polyurethane urea fibers according to claim 18, wherein said
amount of polydimethylsiloxane is from 0.3 to 2 wt. %.
20. Polyurethane urea fibers according to claim 15, wherein said
amount of alkoxylated polydimethylsiloxane is from 0.2 to 3 wt.
%.
21. Polyurethane urea fibers according to claim 20, wherein said
amount of alkoxylated polydimethylsiloxane is from 0.3 to 2 wt.
%.
22. Polyurethane urea fibers according to claim 15, wherein said
amount of metal salt is from 0.05 to 2 wt. %.
23. Polyurethane urea fibers according to claim 22, wherein said
amount of metal sale is from 0.1 to 1.5 wt. %.
24. Polyurethane urea fibers according to claim 15, wherein said
amount of additives is from 0 to 15 wt. %.
25. Elastic fabrics, knitted goods, or hosiery comprising the
polyurethane urea fibers of claim 15.
Description
[0001] The invention relates to a wet spinning or dry spinning
process, especially a dry spinning process, for the production of
polyurethane urea fibers, in which there are added to the
polyurethane urea composition, prior to spinning, from 0.1 to 5 wt.
% polydimethylsiloxane having a viscosity of from 2 to 20 cSt
(25.degree. C.), from 0.1 to 5 wt. % alkoxylated
polydimethylsiloxane having a number average molecular weight of
less than 30,000 g/mol. and a viscosity of from 10 to 5000 cSt
(25.degree. C.), and from 0.01 to 3 wt. % of a fatty acid salt (wt.
% based on the polyurethane urea fibers).
BACKGROUND OF THE INVENTION
[0002] Elastic polyurethane urea fibers are to be understood as
being fibers which are composed to the extent of at least 85 wt. %
of segmented polyurethanes based on, for example, polyethers,
polyesters and/or polycarbonates and aromatic and/or aliphatic
diisocyanates. Polyurethane urea fibers are usually produced by
spinning solutions in accordance with the melt spinning process,
the wet spinning process or, preferably, the dry spinning process.
Suitable solvents for the wet and dry spinning process are polar
solvents, e.g. dimethyl sulfoxide, dimethylformamide,
N-methylpyrrolidone and, preferably, dimethylacetamide. Such
spinning processes are described, for example, in
Polyurethan-Elastomerfasem, H. Gall and M. Kausch in
Kunststoff-Handbuch 7, Polyurethane, Ed.: G. Oertel, Carl Hanser
Verlag Munich Vienna, 1993, pages 679 to 694.
[0003] Polyurethane urea fibers exhibit outstanding elasticity and
pronounced extensibility in combination with high restoring forces.
Owing to that outstanding combination of properties, they are
widely used in the clothing sector. The most important field of use
of such fibers is the elasticizing function for linen, corsetry and
sportswear, such as, for example, bathing suits and bathing trunks,
as well as use in garter welts for hosiery, socks, elastic bands or
diapers.
[0004] The economy of the production of polyurethane urea fibers is
determined in a decisive manner by the spinning process. In the dry
spinning process, for example, the highly viscous spinning solution
is fed to the heated spinning shaft, filtered and pressed through
multihole nozzles, the solvent rapidly evaporating as a result of
hot spinning air that is supplied. The finished individual
filaments are bundled together in the spinning shaft--according to
the desired denier--to form a yarn and bonded together by a
twisting device to form a virtually monofilament thread. A
finishing oil can be applied. The finished thread is finally wound
onto bobbins. In that manner, a 480 dtex elastane thread, for
example, can be produced from 36 individual filaments.
[0005] The economy of that polyurethane urea fiber production
process is dependent in a decisive manner on the speed with which
the thread is wound onto the bobbin. If that speed is high, the
throughput of spinning solution per spinneret is also high. The
spinning solution or additives contained therein should therefore
be so selected that filters do not become blocked during the
spinning process. If blocking nevertheless occurs, the spinning
process must be interrupted. In such a case, the yield and the
economy, associated therewith, is reduced. A second, equally
important parameter in relation to the economy is the achievement
of textile thread data at a constant level throughout the spinning
process. If thread data change during the spinning process,
polyurethane urea fibers that are not within the specification may
be obtained. Products that do not comply with the specification are
removed, and the economy is reduced.
[0006] The object of this invention is to permit the production of
polyurethane urea fibers with constant textile thread data over the
entire spinning process and with increased productivity.
SUMMARY OF THE INVENTION
[0007] It has been found, surprisingly, that this object can be
achieved by adding to the solution of the polyurethane urea
composition, prior to spinning, a mixture of from 0.1 to 5 wt. %
polydimethylsiloxane (PDMS) having a viscosity of from 2 to 20 cSt
(25.degree. C.), from 0.1 to 5 wt. % alkoxylated
polydimethylsiloxane having a molar mass (number average) of less
than 30,000 g/mol. and a viscosity of from 10 to 5000 cSt
(25.degree. C.), and from 0.01 to 3 wt. % fatty acid salt (wt. %
based on the polyurethane urea fibers) and then carrying out the
spinning process.
[0008] The inclusion of pure polydimethylsiloxane in polyurethane
urea fiber spinning solutions is known in principle. It is
described, for example, in DE-A-3 912 510, which describes the
production of elastanes by a special spinning process with the
introduction of superheated steam to produce coarse denier elastane
fibers. Silicone oils are mentioned therein among other possible
additives as flow improvers. U.S. Pat. No. 4,973,647 also mentions
the inclusion of silicone oil in the spinning solution. Neither
document makes any reference to the inclusion of a special
combination of oils having particular properties in the spinning
solution.
[0009] The inclusion of amylsiloxane-modified polydimethylsiloxane
oils in the spinning solution, which is not the subject of the
invention, is also known from specification DE-AS 1 469 452.
[0010] The inclusion in the spinning solution of a combination of
polydimethylsiloxane having a viscosity of from 50 to 300 cSt
(25.degree. C.) and ethoxylated polydimethylsiloxane having a
viscosity of from 20 to 150 cSt (25.degree. C.) in order to produce
polyurethane urea fibers is mentioned in specification EP 643 159.
However, the inclusion of the mixture recommended in that
application in the spinning solution leads to a reduction in the
effectiveness of the anti-adhesion agent, e.g. magnesium stearate.
In order to establish the necessary adhesion for the processing of
the polyurethane urea fibers to, for example, textile fabrics, it
is necessary to include an additional, i.e. an increased, amount of
anti-adhesion agent in the fiber spinning solution. An increased
amount of anti-adhesion agent, e.g. magnesium stearate, leads to a
shortening of the useful lives of filters in the spinning process
owing to increased blocking. The spinning process is interrupted,
with a loss of yield, for the necessary premature filter exchange.
Furthermore, the mixture recommended in the application can, in
dependence on time and temperature, lead to agglomeration of
magnesium stearate before addition to the polyurethane urea
composition fed to the spinning process. As a result of the
agglomerates that form over time, the effectiveness of magnesium
stearate as an anti-adhesion agent can change. As the spinning
process continues, textile data, e.g. adhesion, can change over
time. Polyurethane urea fibers that are not within the
specification are then removed in a complex operation, with a
reduction in yield. That publication makes no reference to the fact
that the viscosity of the polydimethylsiloxane used must not be
below 50 cSt (25.degree. C.). By the inclusion according to the
invention of a mixture of polydimethylsiloxane (PDMS) having a
viscosity of from 2 to 20 cSt (25.degree. C.), alkoxylated
polydimethylsiloxane having a viscosity of from 10 to 5000 cSt
(25.degree. C.) and a fatty acid salt in the spinning solution, the
above-mentioned disadvantages relating to the economy of the
polyurethane urea fiber production do not occur.
[0011] The application of mixtures of polydimethylsiloxane and
polyether-modified PDMS to the finished spun elastane threads by
dipping, spraying or by means of a roller is likewise known (see in
this respect JP 57 128 276 or JP 03 146 774). The application of
such finishing oils serves to improve the take-off properties of
the elastane fibers in warping and knitting processes. There is no
mention in those specifications of the inclusion of the mixture in
the spinning solution. Likewise, there is no indication that
mixtures, especially those containing the compositions according to
the invention, included in the elastane fiber spinning solution can
lead to an improvement in the productivity of the spinning
process.
DETAILED DESCRIPTION
[0012] The invention provides polyurethane urea fibers,
characterised in that they are comprised of
[0013] A) from 99.7 to 65 wt. %, especially from 99.5 to 80 wt. %,
particularly preferably from 99 to 85 wt. %, polyurethane urea
polymer,
[0014] B) from 0.1 to 5 wt. %, especially from 0.2 to 3 wt. %,
particularly preferably from 0.3 to 2 wt. %, polydimethylsiloxane
having a viscosity of from 2 to 20 cSt (25.degree. C.),
[0015] C) from 0.1 to 5 wt. %, especially from 0.2 to 3 wt. %,
particularly preferably from 0.3 to 2 wt. %, alkoxylated
polydimethylsiloxane (PDMS) corresponding to the general formula
(1) 1
[0016] wherein
[0017] PE is the monovalent radical
--CH.sub.2--CH.sub.2--CH.sub.2--O(eo.s- ub.v/po.sub.w).sub.mZ,
[0018] eo represents ethylene oxide,
[0019] po represents propylene oxide and
[0020] Z is either hydrogen or a C.sub.1-C.sub.6-alkyl radical,
[0021] v and w are integers greater than or equal to 0, wherein v
and w are not simultaneously 0,
[0022] x, y and m are integers greater than or equal to 1, which
are preferably so selected that the number average molecular weight
(number average) of formula (1) does not exceed 30,000 g/mol. and
the viscosity of C) is from 10 to 5000 cSt (25.degree. C.),
[0023] D) from 0.01 to 3 wt. %, preferably from 0.05 to 2 wt. %,
particularly preferably from 0.1 to 1.5 wt. %, of a metal salt of a
saturated or unsaturated, mono- or bi-functional C.sub.6-C.sub.30
fatty acid, wherein the metal is a metal selected from the first,
second or third main group of the periodic system, or is zinc,
and
[0024] E) from 0 to 20 wt. %, especially from 0 to 15 wt. %,
additives.
[0025] The invention also provides a process for the production of
improved polyurethane urea fibers by the dry spinning or wet
spinning process, preferably by the dry spinning process, by
preparing the spinning solution, spinning the spinning solution
using a spinneret, forming threads beneath the spinneret by
removing the spinning solvent by drying or in a precipitation bath,
finishing and winding the threads, which process is characterised
in that the following components are added to the polyurethane urea
solution before the solution is spun to form polyurethane urea
fibers:
[0026] B) from 0.1 to 5 wt. %, especially from 0.2 to 3 wt. %,
particularly preferably from 0.3 to 2 wt. %, polydimethylsiloxane
having a viscosity of from 2 to 20 cSt (25.degree. C.),
[0027] C) from 0.1 to 5 wt. %, especially from 0.2 to 3 wt. %,
particularly preferably from 0.3 to 2 wt. %, alkoxylated
polydimethylsiloxane (PDMS) corresponding to the general formula
(1) 2
[0028] wherein
[0029] PE is the monovalent radical
--CH.sub.2--CH.sub.2--CH.sub.2--O(eo.s- ub.v/poO.sub.w).sub.mZ,
[0030] eo represents ethylene oxide,
[0031] po represents propylene oxide and
[0032] Z is either hydrogen or a C.sub.1-C.sub.6-alkyl radical,
[0033] v and w are integers greater than or equal to 0, wherein v
and w are not simultaneously 0,
[0034] x, y and m are integers greater than or equal to 1, which
are preferably so selected that the molecular weight (number
average) of formula (1) does not exceed 30,000 g/mol. and the
viscosity of component C) is from 10 to 5000 cSt (25.degree. C.),
and
[0035] D) from 0.01 to 3 wt. %, preferably from 0.05 to 2 wt. %,
particularly preferably from 0.1 to 1.5 wt. %, of a metal salt of a
saturated or unsaturated, mono- or bi-functional C.sub.6-C.sub.30
fatty acid, wherein the metal is a metal selected from the first,
second or third main group of the periodic system, or is zinc.
[0036] Preference is given also to fibers obtainable by the process
according to the invention.
[0037] The polyurethane urea fibers according to the invention
contain the polydimethylsiloxanes, alkoxylated
polydimethylsiloxanes and fatty acid salts mentioned under B), C)
and D) in finely dispersed form (domains) or in dissolved form. The
domains in the polyurethane urea fibers have a length in the
longitudinal direction of the filaments of especially less than 24
.mu.m, preferably less than 18 .mu.m and particularly preferably
less than 15 .mu.m. The domains in the transverse direction of the
filaments have a size of especially less than 6 .mu.m, preferably
less than 5 .mu.m and particularly preferably less than 4 .mu.m.
The polyurethane urea fibers according to the invention consist of
segmented polyurethane urea polymers. The polymers have a segment
structure, that is to say they consist of "crystalline" and
"amorphous" blocks (so-called hard segments and soft segments).
[0038] The polyurethane urea composition and the polyurethane urea
fibers can be produced especially from a linear homo- or co-polymer
each having a hydroxy group at the end of the molecule and a
molecular weight (number average) of from 600 to 6000 g/mol., such
as polyether diols, polyester diols, polyester amide diols,
polycarbonate diols, or of a mixture or of copolymers of that
group. They are also based on organic diisocyanates, with which the
polymeric diols are reacted to form terminally
isocyanate-functional prepolymers, and diamines or mixtures of
different diamines as chain extenders, with which the terminally
isocyanate-functional prepolymers are reacted to form high
polymers.
[0039] The described reactions are usually carried out in an inert
polar solvent, such as dimethylacetamide, dimethylformamide,
N-methylpyrrolidone or the like. The preparation of terminally
isocyanate-functional prepolymers can also be carried out in the
melt.
[0040] For the preparation of terminal isocyanate-functional
prepolymers it is also possible to use polyester diols and/or
polyether diols in combination with diols that contain tertiary
amino groups. N-Alkyl-N,N-bis-hydroxyalkylamines, for example, are
especially suitable. Examples of components which may be mentioned
here include: 4-tert.-butyl-3-aza-2,6-heptanediol,
4-methyl-4-aza-2,6-heptanediol, 3-ethyl-3-aza-1,5-pentanediol,
2-ethyl-2-dimethylaminomethyl-1,3-propaned- iol,
4-tert.-pentyl-4-aza-2,6-heptanediol,
3-cyclohexyl-3-aza-1,5-pentaned- iol,
3-methyl-3-aza-1,5-pentanediol,
3-tert.-butylmethyl-3-aza-1,5-pentane- diol and
3-tert.-pentyl-3-aza-1,5-pentanediol.
[0041] Examples of organic diisocyanates include
4,4'-dicyclohexylmethane diisocyanate, isophorone diisocyanate and
4,4'-diphenylmethane diisocyanate. Examples of diamines include
ethylenediamine, 1,2-propanediamine, 2-methyl-1,5-diaminopentane,
isophoronediamine, 1,3-diaminocyclohexane,
1-methyl-2,4-diaminocyclohexane and 1,2-diaminocyclohexane. The
desired molecular weight can be established by using a small amount
of monoamines as chain terminator, e.g. diethylamine, dibutylamine
or ethanolamine, during the chain extension. The chain extension
itself can be carried out using CO.sub.2 as retarding agent.
[0042] The polyurethane urea fibers can be prepared according to
processes which are known in principle, such as, for example,
according to those described in specifications U.S. Pat. No.
2,929,804, U.S. Pat. No. 3,097,192, U.S. Pat. No. 3,428,711, U.S.
Pat. No. 3,553,290 and U.S. Pat. No. 3,555,115 and in specification
WO 9 309 174.
[0043] The polyurethane urea fibers according to the invention can
be used in the production of elastic fabrics, knitted goods,
hosiery and other textile products. The invention also provides
that use.
[0044] In accordance with the process according to the invention,
the polydimethylsiloxane having a viscosity of from 2 to 20 cSt
(25.degree. C.) is introduced in a concentration of from 0.1 to 5
wt. %, the alkoxylated polydimethylsiloxane having a molar mass
(number average) of less than 30,000 g/mol. and a viscosity of from
10 to 5000 cSt (25.degree. C.) is introduced in a concentration of
from 0.1 to 5.0 wt. %, and the metal salt of a fatty acid is
introduced in a concentration of from 0.01 to 3.0 wt. %, based on
the polyurethane urea fibers. The weight ratio of
polydimethylsiloxane to alkoxylated polydimethylsiloxane in the
finished phase is preferably 2:1 to 1:2 after adjustment of the
sub-components B), C) and D). The weight ratio of
polydimethylsiloxane to fatty acid salt in the finished phase is
preferably 2:1 to 1:2. The data relating to concentrations mean the
content of oil or fatty acid salt in the finished spun elastane
filament.
[0045] The oils and the fatty acid salt can be added to the
polyurethane urea composition before the production of polyurethane
urea fibers at any desired point in the processing of the
composition. For example, the oils and the fatty acid salt can be
added in the form of a solution to a solution, dispersion or
suspension of other additives. During processing to fibers, they
can then be mixed with or injected into the polymer solution
upstream relative to the fiber spinnerets.
[0046] The incorporation of the oils and of the fatty acid salt
into the polyurethane urea composition is preferably carried out
with the aid of a stock formulation, in which the oils and the
fatty acid salt are dispersed, together with other spinning
auxiliaries, in the solvent, e.g. dimethylacetamide. The stock
formulation is then mixed with the spinning solution by means of a
dynamic or static mixer. The concentration of the two silicone oils
and of the fatty acid salt together in the common stock formulation
solution is preferably from 10 to 25 wt. %.
[0047] The polyurethane urea fibers are then produced from the
resulting spinning solution by the wet spinning or dry spinning
process, preferably by the dry spinning process. Fibers produced by
the process preferably have an individual denier of from 10 to 1280
dtex. The individual deniers can be produced in the form of
monofilaments or from multifilament fibers consisting of, for
example, from 2 to 200 coalesced individual capillaries. After
leaving the spinning shaft, the fibers may be provided with an
external finish.
[0048] Suitable fatty acid salts D) within the scope of the
invention are those whose metal is a metal of the first to third
main groups of the periodic system, or is zinc. The fatty acids are
saturated or unsaturated, are composed of at least six and not more
than 30 carbon atoms and are mono- or bi-functional. The fatty acid
salts according to the invention are especially lithium, magnesium,
calcium, aluminum and zinc salts of oleic, palmitic or stearic
acid, particularly preferably magnesium stearate, calcium stearate
or aluminum stearate.
[0049] The polyurethane urea compositions or polyurethane urea
fibers according to the invention produced therefrom can contain as
additives E) delustering agents, fillers, antioxidants, dyes,
pigments, staining agents, and stabilizers against heat, light, UV
radiation, chlorine-containing water, chemical fiber-cleaning
agents, especially chlorinated hydrocarbons, and against
vapors.
[0050] Examples of antioxidants and stabilizers against heat, light
or UV radiation are stabilizers from the group of the sterically
hindered phenols, HALS stabilizers (hindered amine light
stabilizer), triazines, benzophenones and benzotriazoles. Examples
of pigments and delustering agents are titanium dioxide, zinc oxide
and barium sulfate. Examples of dyes are acid dyes, dispersion and
pigment dyes and optical brightening agents. Examples of
stabilizers against degradation of the fibers by chlorine or
chlorine-containing water are zinc oxide, magnesium oxide,
calcium-magnesium carbonates, calcium-magnesium hydroxy carbonates
or magnesium-aluminum hydroxycarbonates, especially hydrotalcite.
The mentioned stabilizers can also be used in the form of mixtures
and contain an organic or inorganic coating agent.
[0051] The invention is explained in greater detail below by means
of Examples, which do not, however, represent any limitation of the
invention.
EXAMPLES
[0052] The polyurethane urea solution used for the following
Examples is prepared in accordance with the following
procedure:
[0053] In all the Examples, polyurethane urea compositions are
prepared from a polyester diol having a molecular weight (number
average) of 2000 g/mol., which consists of adipic acid, hexanediol
and neopentyl glycol and has been masked with methylene
bis(4-phenyldiisocyanate) (MDI, Bayer AG) and then chain-extended
with a mixture of ethylenediamine (EDA) and diethylamine (DEA).
[0054] The polyurethane urea compositions for each of the Examples
are prepared by the same process.
[0055] For the preparation of the polyurethane urea composition, 50
wt. % polyester diol having a molecular weight (number average) of
2000 g/mol. are mixed with 1 wt. % 4-methyl-4-aza-2,6-heptanediol,
and 36.2 wt. % dimethylacetamide (DMAC) and 12.8 wt. % MDI at
25.degree. C., heated to 50.degree. C. and maintained at that
temperature for 110 minutes in order to obtain an isocyanate-masked
polymer having an NCO content of 2.65% NCO.
[0056] After cooling to a temperature of 25.degree. C., 100 parts
by weight of the masked polymer are rapidly mixed into a solution
of 1.32 parts by weight of EDA and 0.04 parts by weight of DEA in
187 parts of DMAC so that a polyurethane urea composition in DMAC
having a solids content of 22% is formed. By addition of
hexamethylene diisocyanate (HDI, Bayer AG), the molecular weight of
the polymer is adjusted to give a viscosity of 70 Pa*s (25.degree.
C.).
[0057] Following the preparation of the polymers as described in
the preceding section, a stock formulation of additives is added
thereto. The stock formulation consists of 65.6 wt. % DMAC, 11.5
wt. % CYANOX.TM. 1790
((1,3,5-tris(4-tert.-butyl-3-hydroxy-2,5-dimethylbenzyl)-1,3,5-triazine-2-
,4,6-(1H,3H,5H)-trione, Cytec), 5.7 wt. % TINUVIN.TM. 622 (polymer
having a molar mass of about 3500 g/mol., consisting of succinic
acid and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidine ethanol, Ciba
Geigy), 17.2 wt. % 22% spinning solution and 0.001 wt. % of the dye
MAKROVOEVIOLETT.TM. B (Bayer AG). The stock formulation is metered
into the spinning solution in such a manner that the content of
CYANOX.TM. 1790 is 1.0 wt. % and the content of TINUVIN.TM. 622 is
0.5 wt. %, based on the total solids content in the polyurethane
urea composition.
[0058] A second stock formulation, consisting of 31 wt. % titanium
dioxide (TRONOX.TM. TiO.sub.2 R-KB-3, Kerr-McGee Pigments GmbH
& Co. KG), 44.5 wt. % dimethylacetamide and 24.5 wt. % 22%
spinning solution is added to the first spinning solution in such a
manner that the titanium dioxide content in the finished thread is
0.05 wt. %, based on the finished polyurethane urea fibers.
[0059] Further stock formulations are then added to that spinning
solution. They consist of 5.3 wt. % magnesium stearate (Peter
Greven), 49.6 wt. % DMAC, 33.8 wt. % 22% spinning solution, 6.0 wt.
% polydimethylsiloxane and 5.3 wt. % SILWET.TM. L 7607 (Crompton
Specialities GmbH; ethoxylated polydimethylsiloxane,
methyl-terminated, molecular weight 1000 g/mol., viscosity 50 cSt
(25.degree. C.)), which are so chosen that the percentage contents
indicated in Examples 1 to 3 are obtained in the finished
fibers.
Example 1
[0060] Additive content in the finished polyurethane urea
fibers:
[0061] 0.28 wt. % magnesium stearate
[0062] 0.28 wt. % SILWET.TM. L 7607
[0063] 0.32 wt. % BAYSILONE.TM. oil M 5 (polydimethylsiloxane GE
Bayer Silicones, viscosity 5 cSt (25.degree. C.)).
Example 2
[0064] Additive content in the finished polyurethane urea
fibers:
[0065] 0.19 wt. % magnesium stearate
[0066] 0.19 wt. % SILWET.TM. L 7607
[0067] 0.22 wt. % BAYSILONE.TM. oil M 5 (GE Bayer Silicones,
viscosity 5 cSt (25.degree. C.)).
Example 3 (Comparison)
[0068] Additive content in the finished polyurethane urea
fibers:
[0069] 0.28 wt. % magnesium stearate
[0070] 0.28 wt. % SILWET.TM. L 7607
[0071] 0.32 wt. % BAYSILONE.TM. oil M 100 (GE Bayer Silicones,
viscosity 100 cSt (25.degree. C.)).
[0072] In Examples 1 to 3, the polyurethane urea composition is
spun in a spinning apparatus typical for a dry spinning process to
form filaments having a denier of 11 dtex, 4 individual filaments
being combined to form coalesced filament yarns of 44 dtex and
being wound at a take-off speed of 550 m/min.
[0073] The filaments so obtained are tested for their mechanical
properties and characterised. To that end, the count-related
strength (CS) and the elongation at break (EB) in particular are
measured in accordance with DIN 53834 Part 1. For that purpose,
tensile tests are carried out on elastane filament yarns in the
air-conditioned state. To that end, the prepared test specimen is
placed in a loop around the hook of the measuring head and placed
round a 10 mm looping clamp with a pretensioning force of 0.001
cN/dtex. The clamped length is 200 mm overall. A small vane of
aluminum foil is suspended precisely at the level of a light
barrier. The slide travels at a rate of deformation of 400%/min
(800 mm take off) until the thread breaks, and returns to its
starting position again after the measurement. 20 measurements are
carried out per test specimen.
[0074] The adhesion of the thread to a bobbin is determined by
first detaching the thread from the bobbin above the bobbin case
with a weight of 500 g, except for 3 mm. A weight is then suspended
from the thread and the weight at which the thread unrolls from the
bobbin is determined. The adhesion so determined is a measure of
the processability of the bobbins. If the adhesion is too high,
processability to sheet-form textile products may be made more
difficult owing to the tearing of threads. If the adhesion is too
low, it is possible that, during the winding process in the dry
spinning shaft or during further processing of the bobbin to
textile fabrics, the thread may fall off the bobbin, tear and
accordingly not undergo further processing.
[0075] The optical uniformity is evaluated by the method described
hereinbelow.
[0076] In a first step, 1340 threads of denier dtex 44 are warped
with a preliminary draft of 156% and a final draft of 40% onto two
sectional warp beams (SWBs) of an elastane warping machine (type
DSE 50/30 from Karl Mayer, Oberhausen).
[0077] In a second step, an elastic warp-knitted fabric is produced
from those sectional warp beams together with two SWBs of polyamide
dtex 44/10 from Snia. A type HKS 2/E 32 warp loom (Karl Mayer,
Oberhausen) is used as the warp knitting machine.
[0078] The warp-knitted fabrics so produced are then relaxed on a
steaming table. In the further process, fixing with hot air is
carried out in the non-prewashed state on a tenter frame for 40
seconds at 195.degree. C. and with an overfeed of 8%. The fixing
width is 100 cm.
[0079] In a separate pass through the tenter frame, the fixed
fabric is wound cold onto perforated dyeing beams.
[0080] The fabric is dyed blue in a beam dyeing apparatus in
accordance with the following formulation:
[0081] 0.90% TELON.TM. Lichtblau RR 182% (Bayer AG; acid dye)
[0082] 0.05% TELON.TM. Echtorange AGT 200% (Bayer AG; acid dye)
[0083] 2.00 g/l sodium acetate
[0084] 1.50% LEVOGAL.TM. FTS (Bayer AG; leveling agent) and
[0085] 0.30 ml/l acetic acid.
[0086] Before all the auxiliaries are added, the closed apparatus
is first filled with water with no circulation of liquor. The
addition of the above-mentioned auxiliaries is carried out after
the circulation pump has been switched on and the required pressure
of 2.2 to 2.0 bar has been established. Heating of the liquor is
carried out at 1.degree. C. per minute, the chosen liquor direction
being outside/inside up to 80.degree. C. and the liquor being
pumped from the inside outwards above 80.degree. C. Once the
required final temperature of 98.degree. C. has been reached, the
further treatment time is 60 minutes. Indirect cooling to
70.degree. C. is then carried out, followed by continuous rinsing
by the supply of fresh cold water and, finally, rinsing once more
with fresh water.
[0087] After dyeing, the dyeing beams with the wet fabric are
delivered to the padding machine, passed through rinsing water
during passage through the padding machine and uniformly squeezed
dry.
[0088] Subsequent intermediate drying is carried out in a
perforated cylinder drier at 120.degree. C. with a rate of travel
of about 7 m/min. The fabric is folded flat on entering the
perforated cylinder drier.
[0089] The intermediately dried fabric is finally tentered in a
tenter frame at a temperature of 150.degree. C. and at a fabric
speed of 10 m/min and with an overfeed of 5%, resulting in a smooth
finished fabric which is wound up on leaving the tenter frame.
[0090] Optical uniformity is evaluated by means of a visual
inspection of the finished dyed fabrics both in transmitted light
and in reflected light and is evaluated by means of a scale of
ratings (test rating) which ranges from 1 to 9. For the
polyurethane urea fibers dtex 44 described here, rating 4
represents a very uniform fabric, rating 5 still corresponds to
good uniformity, rating 6 corresponds to satisfactory uniformity.
If a fabric is rated 7, it can be used only for special purposes.
Fabrics rated 8 and 9 are unsaleable.
[0091] Table 1 shows the determined filament properties and the
test ratings for evaluation of the optical uniformity.
1TABLE 1 Tabular comparison of the thread data and the test ratings
for evaluating optical uniformity: Example Denier CS EB Adhesion
number (dtex) (cN/dtex) (%) (cN) Test rating 1 43.6 1.24 417 0.05
n.d. 2 45.7 1.21 420 0.23 5.0 3 (comparison) 45.2 1.21 402 0.23 5.0
CS: count-related strength, EB: elongation at break.
[0092] As the Examples show, the adhesion is clearly changed by the
addition of a stock formulation based on BAYSILONE.TM. oil M5 in
comparison with one based on BAYSILONE.TM. oil M100. Accordingly,
the adhesion is considerably reduced by addition of a stock
formulation based on BAYSILONE.TM. oil M5 in comparison with
BAYSILONE.TM. oil M100. It can thus be demonstrated that the
effectiveness of magnesium stearate as an anti-adhesion agent is
clearly increased when a stock formulation based on BAYSILONE.TM.
oil M5 is used. In the case of the stock formulation based on
BAYSILONE.TM. oil M100, the effectiveness of magnesium stearate is
reduced as a result of agglomerate formation. By reducing the
inclusion of BAYSILONE.TM. oil M5 in the spinning solution, the
adhesion can readily be adjusted to the level of the stock
formulation based on BAYSILONE.TM. oil M100. By including a stock
formulation based on BAYSILONE.TM. oil M5 in the spinning solution,
the useful life of filters in the spinning process can be
lengthened and the productivity accordingly increased.
[0093] The count-related strength (CS) and the evaluation of
optical uniformity are independent of the stock formulation and
remain unchanged at a constant level.
[0094] In the series of tests for Examples 4 to 9, stock
formulations were prepared with different polydimethylsiloxanes and
alkoxylated polydimethylsiloxanes. The stock formulations consist
of 5.3 wt. % magnesium stearate (Peter Greven), 49.6 wt. % DMAC,
33.8 wt. % 30% spinning solution, 6.0 wt. % polydimethylsiloxane
and 5.3 wt. % alkoxylated polydimethylsiloxane.
[0095] The stock formulations are stored at 25.degree. C. and
50.degree. C. and their homogeneity is assessed immediately and
after standing for 24 hours.
[0096] The assessment of the homogeneity of the stock formulations
is shown in Table 2.
[0097] The 30% spinning solution used to prepare the stock
formulations is prepared from a polyether diol consisting of
polytetrahydrofuran (PTHF, e.g. Terathane 2000 from Du Pont) having
an average molecular weight (number average) of 2000 g/mol. The
diol is masked with methylene bis(4-phenyldiisocyanate) (MDI, Bayer
AG) at a molar ratio of 1 to 1.65 and then chain-extended with a
mixture of ethylenediamine (EDA) and diethylamine (DEA) in a weight
ratio of 97:3 in dimethylacetamide (DMAC). The ratio of the amount
of chain extender and chain terminator to unreacted isocyanate in
the prepolymer is 1.075. The solids content of the resulting
polyurethane urea solution is 30 wt. %.
[0098] A stock formulation of additives is then mixed with the
polymer. That stock formulation consists of 62.7 wt. %
dimethylacetamide (DMAC), 10.3 wt. % CYANOX.TM. 1790
((1,3,5-tris(4-tert.-butyl-3-hydroxy-2,5-dimet-
hylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, Cytec), 27.0 wt.
% 30% spinning solution and 0.001 wt. % of the dye
MAKROLEXVIOLET.TM. B (Bayer AG). The stock formulation is added to
the polyurethane urea composition in such a manner that the content
of CYANO.TM. 1790 is 1.0 wt. %, based on the total solids
content.
Example 4
[0099] 5.3 wt. % magnesium stearate
[0100] 6.0 wt. % BAYSILONE.TM. oil M 3 (GE Bayer Silicones,
viscosity 3 cSt (25.degree. C.))
[0101] 5.3 wt. % SILWET.TM. L7607 (Crompton Specialities GmbH;
ethoxylated polydimethylsiloxane, methyl-terminated, molecular
weight 1000 g/mol., viscosity 50 cSt (25.degree. C.)).
Example 5
[0102] 5.3 wt. % magnesium stearate
[0103] 6.0 wt. % BAYSILONE.TM. oil M 5 (GE Bayer Silicones,
viscosity 5 cSt (25.degree. C.))
[0104] 5.3 wt. % SILWET.TM. L7607 (Crompton Specialities GmbH;
ethoxylated polydimethylsiloxane, methyl-terminated, molecular
weight 1000 g/mol., viscosity 50 cSt (25.degree. C.)).
Example 6 (Comparison)
[0105] 5.3 wt. % magnesium stearate
[0106] 6.0 wt. % BAYSILONE.TM. oil M 100 (GE Bayer Silicones,
viscosity 100 cSt (25.degree. C.))
[0107] 5.3 wt. % SILWET.TM. L7607 (Crompton Specialities GmbH;
ethoxylated polydimethylsiloxane, methyl-terminated, molecular
weight 1000 g/mol., viscosity 50 cSt (25.degree. C.)).
Example 7
[0108] 5.3 wt. % magnesium stearate
[0109] 6.0 wt. % BAYSILONE.TM. oil M 5 (GE Bayer Silicones,
viscosity 5 cSt (25.degree. C.))
[0110] 5.3 wt. % SILWET.TM. L77 (Crompton Specialities GmbH;
ethoxylated polydimethyl-siloxane, methyl-terminated, molecular
weight 600 g/mol., viscosity 20 cSt (25.degree. C.)).
Example 8
[0111] 5.3 wt. % magnesium stearate
[0112] 6.0 wt. % BAYSILONE.TM. oil M 5 (GE Bayer Silicones,
viscosity 5 cSt (25.degree. C.))
[0113] 5.3 wt. % SILWET.TM. L7608 (Crompton Specialities GmbH;
ethoxylated polydimethylsiloxane, hydrogen-terminated, molecular
weight 600 g/mol., viscosity 35 cSt (25.degree. C.)).
Example 9 (Comparison)
[0114] 5.3 wt. % magnesium stearate
[0115] 6.0 wt. % BAYSILONE.TM. oil M 100 (GE Bayer Silicones,
viscosity 100 cSt (25.degree. C.))
[0116] 5.3 wt. % SILWET.TM. L7608 (Crompton Specialities GmbH;
ethoxylated polydimethylsiloxane, hydrogen-terminated, molecular
weight 600 g/mol., viscosity 35 cSt (25.degree. C.)).
2TABLE 2 Tabular comparison of the homogeneity of stock
formulations: Example Homogeneity Homogeneity Homogeneity numbers
after preparation after 24 h/25.degree. C.* after 24 h/50.degree.
C.* 4 very good very good Very good 5 very good very good Very good
6 (comparison) phase separation phase separation Agglomeration 7
very good very good Very good 8 very good very good Very good 9
(comparison) phase separation phase separation Agglomeration
*storage temperature of the stock formulations.
[0117] As the Examples show, the homogeneity of the stock
formulations is highly dependent on the viscosity of the
polydimethylsiloxanes used. Phase separation occurs and the
homogeneity of the stock formulations is lost if a more highly
viscous polydimethylsiloxane is used with BAYSILONE.TM. oil M100.
In such stock formulations, agglomerates even form at a storage
temperature of 50.degree. C., as is conventional in the preparation
of polyurethane urea compositions for the production of
polyurethane urea fibers. In the production of polyurethane urea
fibers, the formation of agglomerates leads to a reduction in the
effectiveness of magnesium stearate as an agent for adjusting the
adhesion, to a level of adhesion which changes over the duration of
the spinning process, and to shortened filter useful lives.
Accordingly, owing to the agglomerates, it is not possible to
establish constant textile fiber data (adhesion) during the
continuous production of polyurethane urea fibers. At the same
time, the productivity of the spinning process is reduced.
* * * * *