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Патент USA US3082067

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Patented Mar. 19, 1961
Ward ?nding other chemicals that would exert a mor
Bernard F. Walker, Asheville, N.C., assignor to American
Enka Corporation, Erika, N.C., a corporation of Delta
No Drawing. Filed Feb. 9, 1962, Ser. No. 172,089
3 Claims. ((31. 18—54)
This application is a continuation-impart of applica
tion Serial No. 61,039, ?led June 9, 1960, which in turn
is 1a continuation of application Serial No. 678,766, ?led
‘ August 19, 1957, now abandoned. This invention relates
to the production of shaped articles of regenerated cellu
desirable effect than the known additives. Along this lin
it was found that yarn properties are enhanced in a mo:
favorable manner when the viscose is spun in the presenc
of ethoxylated amines such as those disclosed in US
Patent No. 2,572,217 and quaternary derivatives of suc
ethoxylated primary amines.
However, when using these types of ethoxylated amine
and their derivatives, foaming problems were encountere
when the additive was incorporated during the dissolvin
of the xanthate crumbs and additionally, the viscose cor
taining the additive was very dif?cult to deaerate.
Another phenomenon that was observed was that th
viscose containing the additive became cloudy sever;
lose from viscose and more particularly to the produc
tion of specially modi?ed high tenacity viscose rayon yarn 15 hours after the modi?er was added to the viscose. A;
and rayon tire cord having physical properties superior
patently, a reaction occurs between the viscose and th
to normally modi?ed yarn and cord.
modi?er which may be either physical or chemical an
which produces objectionable products that may be eithe
Due to extensive research being conducted by various
soluble, giving clear viscose, or insoluble, giving cloud
rayon manufacturers, improvements in the physical prop
erties of rayon are being made constantly. Although vis 20 viscose. It seems likely that the by-products of this reac
cose rayon y-arn possesses many qualities that make it
especially suitable for use in reinforcing rubber articles
such as cord tires and the like, there is a continuing need
to improve the strength and resistance to ?ex fatigue of
tion are produced at a steady rate commencing as 500
as the viscose and the modi?er are mixed. It would als
seem probable that the sudden development ‘of cloudines
is only incidental and may occur at the time when th
the yarn. In recent years a most signi?cant technological 25 concentration of reaction products suddenly reaches th
limit of their solubility in the viscose. There are thu
advance in improving the tenacity and ?ex life of viscose
rayon yarns resulted from the discovery that certain
two probabilities, either (a) soluble, harmful reactio
chemicals under particular spinning conditions modify
products present in the viscose from the moment of mi)
and retard the regeneration of cellulose after extrusion.
ing, increasing in concentration with time; and (b) it
soluble, harmful reaction products which develop some
time after mixing, which apparently induce the form:
These chemical additives which improve the physical
properties of the yarn have become known in the art as
viscose modi?ers. Modi?ers that are already disclosed in
the prior art include, for example, certain aliphatic and
aromatic monoamines, quaternary ammonium compounds,
and N-substituted dithiocar-bamic acids having speci?c
solubilities (U.S. Patents 2,535,044—5, 2,536,014, and
The mechanisms by which a modi?er changes the nor
mal spinning process have not been de?nitely established,
although several theories have been advanced in this con
nection. However, the modi?ed yarns have characteris
tion of voids discussed above.
In an effort to overcome these problems, and mor
particularly the foaming and deaeration problems, th
modi?er was injected into the viscose just prior to spit
ning the viscose. The aforesaid problems were effective
ly overcome but, what was quite unexpected, the physicz
properties of the cord made from the yarn were signi?can'
ly improved, especially in regard to strength withot
sacri?cing resistance to ?ex fatigue, as will be shown hert
The injection method apparently circumvent
tics which are readily distinguishable over normal yarn.
the harmful effect of by-products whether soluble or it
crenulations. At the same time, it was found that a modi
Heretofore the point at which the modi?er was adde
to the spinning process was not considered critical as ion
as the additive was present when the viscose was extrude
soluble. The primary bene?t of using the injection sy:
At ?rst, investigators discovered that cross sections of the
tem seems to be that the strength of the cord is signi?can'
?laments produced under the influence of'a modi?er show
that the ?laments have a surface with notably reduced 45 1y improved, or in other words, the cording loss is Cit
- ?ed yarn has a very different skin and core structure
which could be observed by viewing stained cross sec
tions of the yarn under a microscope. A modi?ed yarn,
50 into the setting ‘bath. The prior art suggested very gene]
it was seen, has a greater proportion of skin to core, as
compared with yarn formed by the conventional methods.
In observing the skin structure of a modi?ed yarn, an
other visible characteristic was always associated with
modi?ed yarns. Dark spots could be seen throughout the
ally that the modi?er could ‘be added to the setting bat]
to the viscose, or in almost any stage in the productio
of viscose.
The primary considerations in this resper
were the stability and solubility of the modi?er with se<
55 ondary attention given to improvements in the physicz
cross sectional area of the yarns when cross sections of
properties of the yarn.
modi?ed yarns were stained and viewed under a light
microscope. Initially, no explanation could be given for
On the contrary, by the present invention it has bee
these dark spots, which later became known as “freckles.”
found that the time at which the modi?er is added t
Subsequently, it was discovered by observing longi
tudinal sections of modi?ed yarns under an electron mi
croscope, that the ‘so-called freckles were in fact tiny
voids or cavities in the yarns. Generally, the voids are
elliptical in cross section with the long axes thereof par
alleling the yarn axis which indicated that the voids are
the viscose spinning system is highly important to produc
a modi?er yarn which forms superior cords. It has no‘
been discovered that by adding the modi?er to the viscos
spinning solution shortly before it reaches the SPlIlIlCTv‘
and thereafter spinning the viscose, improved proces
ability and improved physical properties of the cord a1
present prior to the stretching of the yarn, because 65 obtained. In addition to avoiding the foaming and deaer:
tion problems and improving the strength and resistant
stretching orients and elongates the voids. Accordingly,
it was thought that the effectiveness of viscose modi?ers
was somewhat related to the formation of the voids within
the freshly spun yarn in View ‘of the fact that the voids
were always present in the known modi?ed yarns.
to ?ex fatigue, a brighter yarn is produced by the prese1
invention. Furthermore, the yarn of the present inventic
very surprisingly is substantially free from the voids :
After the discovery that certain chemicals modify the
regeneration of cellulose, research work was directed to
It is' an object of the present invention to provide
process for manufacturing high tenacity modi?ed regel
discussed above.
:rated cellulose yarn from viscose thatforms cords of
viewed under an electron microscope. Furthermore, the
yarn has a brighter luster than normally modi?ed yarn.
A further understanding of the process and the novel
yarn of this invention will be obtained from the following
speci?c examples which are intended to illustrate the
present invention, but not to limit the scope thereof.
Alkali cellulose prepared from wood pulp was aged
mproved physical properties as compared with known
nodi?ed yarn cord.
An additional object is to provide a high tenacity, highly
atigue-resistant modi?ed cord that is characterized by
he substantial absence of voids normally present in modi
ied yarns.
Other objects and advantages will become apparent
rom the following detailed description.
These objects are accomplished by incorporating in the 10 in a known manner. This alkali cellulose Was then
xanthated with 37.7% carbon disul?de, based on the
'iscose a modi?er at a time not too remote from the
weight of the cellulose. The xanthate crumbs so produced
pinning of the viscose into a setting bath. Compounds
were dissolved in a solution of sodium hydroxide of a pre
generally suitable for use in accordance with the present
determined strength to produce a viscose having 7.5%
nvention are those additives which, when added to a vis
‘ose solution in sufficient amounts, retard the subsequent 15 cellulose and 5.7% sodium hydroxide. During the dis
solving process a viscose modi?ed, namely the methyl
egeneration of the cellulose but during ripening of the
chloride quaternary derivative of an ethoxylated coconut
'iscose will normally form a cloudy viscose solution. In
oil amine having the general formula:
.ddition, these compounds may be distinguished by the
act that they tend to induce aeration and foaming in the
Among the compounds suitable in the practice of the
>resent invention are those described in application Serial
~10. 609,792, now abandoned, and in said U.S. Patent
~10. 2,572,217.
in which formula x plus y=approximately l5 and R is a
These compounds have the general
saturated hydrocarbon radical containing 8—l8 carbon
25 atoms, was added in the amount of 2.5% based on the
cellulose content.
Foaming was noticeable in the dis—
solving operation; and the viscose could not be ef?ciently
deaerated in the usual vacuum deaerating tanks. It was
observed that the viscose became somewhat turbid after
about four hours.
vhere R1 and R2 represent preferably an alkyl radical
The viscose, after being properly ?ltered and aged, was
rut may include an aryl or alicyclic radical with R1 pref
rably being an alkyl radical containing six or more
arbon atoms and R2 being an alkyl radical containing
me to three carbon atoms; Z represents an anion having
ubstantially no surface activity such as hydroxide, halide,
primary setting bath containing 4.8% sulfuric acid, 13.7%
ulfate, acetate, etc.; x and y are whole numbers of at
east one with the preferred combined value of x and y
icing 2 to 50 more, depending on the purpose for which
a high stretch in a second bath having the composition of
4.0% sulfuric acid, 4.0% sodium sulfate, and 0.7% zinc
sulfate, said bath being maintained at 93° C. The yarn
spun into yarn by extruding it through a spinneret into a
Na2S-O4 and 4.0% ZnSO4. The temperature of the bath
was maintained at 65° C. Thereafter the yarn was given
he additiveis used; 11 is also a whole number, possibly 40 was aftertreated in a conventional manner.
The conditioned and wet strength values of unslashed
me but preferably two or no more than four. These qua
singles of the yarn so produced were respectively 411
:rnary derivatives of ethoxylated primary amines are
g/ 100 denier and 305 g./100 denier. Singles given a
nown in the trade as “Ethoquads.”
' 10% slashing stretch had a conditioned strength of 445
The compounds of U.S. Patent No. 2,572,217 are known
g./ 100 denier and a wet strength of 321 g./100 denier.
1 the trade as “Ethomeens” and are reaction products of
The slashed singles were plied into the tire cord con
mg chain aliphatic primary amines with ethylene oxide,
struction seen in Table I wherein physical properties
1e reaction being represented generally as follows:
thereof are given.
(CnH2nO) :11
Table I
ENE: + (z + wonmno —> RN
(0 uHZnO) 11H
11 the above formula, R represents an aliphatic chain
aving from 8 to 24 carbon atoms therein and preferably
rom 12 to 14 carbon atoms.
Cord construction
x or y is at least one,
nd x plus y is the total number of alkylene oxide chains 55
lhlClZl may be as low as 5 without any de?nite restriction
n the upper limit, although 12 to 18 or about 15 have
een found to be quite effective, and n is a small whole
umber from 2 to 4, both inclusive.
A preferred method of adding the modi?er to the vis
ose is by injecting predetermined amounts, e.'g. 1.0%
11.4 x 10 6
Denier ............................... ..
3, 613
Conditioned strength, lbs ___________ ._
30. 6
Conditioned strength, g./100 den _ .
_ _ __
Oven dry strength, lbs _________ __
36. 4
Oven dry strength, g./l00 den _________ __
Firestone fatigue, hrs.
12 x 12
The yarn appeared to be dull and milky when observed
on a yarn viewing card. Cross sections of the yarn when
60 stained and viewed under a light microscope showed
the ifreckles as described above. By viewing longitudinal
.0% , of the material based on the weight of the cellulose
no a ?owing stream of viscose by any suitable type of
sections of the yarn under an electron microscope, it was
noted that the yarn had many voids within the yarn.
ijection system, such as that shown in application Serial
10. 655,004, ?led April 25‘, 1957, now Patent No. 65
329,731, and having common ownership‘ herewith,
A viscose was prepared in the same manner as de
aoroughly mixing the viscose and modi?er and thereafter
pinning the mixture in a conventional manner.
The yarn produced by the present invention is par
.cularly characterized by the fact that it is substantially
ll skin modi?ed viscose rayon yarn having tenacity and
atigue resistance in a cord construction superior to
ormally modi?ed yarn and further characterized by a
ubstantial absence of freckles when viewed under a light
iicroscope and a substantial absence of voids when
scribed in Example I with the exception that the viscose
modi?er was not added during the dissolving of the
xanthate crumbs. In the present example, a 6.4% aque
ous solution of the additive used in Example I was in
jected into the aged, ?ltered and deaerated viscose being
pumped to the spinnerets through a conduit. Between
the point of injection and the spinneret, the viscose con
taining the additive was continuously mixed in a blend
ing device provided with internal mixing means.
The viscose was extruded into a primary bath having
the same composition as in Example -I. The yarn was
stretched, passed through a second bath, and aftertreated
?cations may be made in the methods of procedure with
out departing from the spirit of the invention.
What is claimed is:
1. In a method of producing a high tenacity modi?er
in the manner also described in Example I.
The conditioned and wet strength values of unslashed
viscose rayon yarn involving the use of a type of modi?e
singles of the yarn so produced were respectively 395
which when added to the viscose solution in the re
g./ 100 denier and 310‘ g./€100 denier. Singles given a
quired amounts will normally induce aeration and foam
10% slashing stretch had a conditioned strength of 460
ing therein, the improvement that comprises injecting 1.0L
g./100* denier and a Wet strength of 325 g_/100 denier.
6.0%, based on the weight of the cellulose in the viscose
The slashed singles were plied into the tire cord con 10 of a modi?er of the class consisting of ethoxy-lated amine
struction seen in Table II wherein physical properties
and quaternary derivatives thereof, into a ?owing strean
thereof are ‘given.
of normally ripened viscose just prior to spinning, pass
Table II
Cord construction
Denier _______________________________ _ _
11.4 x 10 6
12 x 12
3. 565
3, 657
Conditioned strength, lbs ...... __
Conditioned strength, g./100 den
s _____ _.
35. 3
Oven dried strength, g./lOO den
Oven dried strengt ,
Firestone fatigue, hrs_
______ __
4. 5
An analysis of the data given in the tables showing a
highly signi?cant improvement in the cord strengths of
the yarn produced by injecting the additive into the ripened
viscose as compared with the yarn produced by incorporat
ing the additive during the dissolving operation.
ing the mixture into a blending zone, and before anj
objectionable aeration and foaming can occur in the vis
15 cose solution, directly extruding the same into a coagul-at
ing bath to ‘form yarn therefrom.
2. In a method of producing a high tenacity modi?er
viscose rayon yarn involving the use of a type of modi
?er which when added to the viscose solution in the re
quired amounts will normally induce aeration and foam
ing therein, the improvement that comprises injecting 1.0
6.0%, based on the Weight of the cellulose in the viscose
of an ethoxylated amine into a ?owing stream of normally
ripened viscose just prior to spinning, passing the mixturi
25 into a blending zone, and before any objectionable aera
tion and foaming can occur in the viscose solution, di
rectly extruding the same into a coagulating bath to forn
The yarn produced in the present example had a
yarn therefrom.
bright, lustrous appearance when observed on a yarn
3. In a method of producing a high tenacity modi?e<
viewing card. The spinnability of the viscose was im 30 viscose rayon yarn involving the use of a type of modi?e
proved and the viscose was very clear when extruded.
which when added to the viscose solution in the requiret
Cross sections of the yarn, when stained and viewed un
amounts will normally induce aeration ‘and foaming
der a light microscope, were practically free of freckles
therein, the improvement that comprises injecting 1.0
and had a homogeneous skin structure. By viewing
60%, based on the weight of the cellulose in the vis
longitudinal sections of the yarn under an electron micro 35 cose, of a quaternary derivative of an ethoxylated amini
scope, substantially no voids were noticed within the
into a ?owing stream of normally ripened viscose jus
y The yarn had a high degree of molecular orientation as
prior to spinning, passing the mixture into a blending
zone, and before any objectionable aeration and foam
ing can occur in the viscose solution, directly extruding
determined by X-ray diifraction measurement. Although
high orientation is characteristic of high tenacity but 40 the same into a coagulating bath to form yarn there
ordinarily brittle yarn, it was surprising that such proper
ties would be present in the yarn of the instant inven
tion, especially in view of the fact that the present yarn is
not brittle but is highly resist-ant to flex fatigue.
While the speci?c examples of the preferred methods
embodying the present invention have been set forth
above, it will be understood that many changes and modi
References Cited in the ?le of this patent
‘Stokes ______________ .__ Sept. 15, 193
Tallis et al ____________ __ Aug. 7, 195"
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