CA1051616A - Treated thermoplastic organic polymer fibers and method for preparing same - Google Patents

Abstract

--Abstract of the Disclosure - Desirable properties such as flame retardancy, dyeability, resistance to soiling, microorganisms, degradation by heat and/or light, and a reduced tendency to accumulate static electric charges can be imparted to fibers of thermoplastic organic polymers by applying a liquid modifier or a solution or dispersion containing one or more solid or liquid modifiers and a liquid medium to the fiber surface prior to drawing of the fiber, or preferably, as the fiber is being drawn. The imparted properties are not substantially affected following abrasion of the fiber surface or exposure of the fibers to liquids which are solvents for the modifier but not for the polymer comprising the fiber.

- i -

Description

-105~L61~
It is customary to employ various materials to treat textile fibers for the purpose of imparting cer-tain desirable properties or modifying those properties which are inherent in the composition or structure of the fiber. Flame retardancy, dyeability, resistance to the accumulation of static electrical charges, soiling and mildew are examples of properties which are often imparted or enhanced by means of relatively low molecular weight organic modifiers that are either present in the bulk polymer prior to the spinning operation or are applied to the surface of tlle fiber at some step during processing. Application of modifiers to a fiber surface using conventional techniques is often less than satisfactory ` ~~ -if the property imparted is to be retained for relatively long periods of time, since the modifiers may readily be removed by abrasion of the fiber surface or during con-ventional laundering or drycleaning operations.
The alternative method of incorporating the modifier into a solubilized polymer for use in a solution spinning process requires that the modifier be soluble or mechanically dispersed in the solvent(s) for the polymer at the desired concentration and that it not cause coagulation of the dissolved polymer. These - criteria limit to a significant extent the number of suitable modifiers, particularly if the modifiar is to withstand the elevated temperatures employed in a conventional "dry spinning" operation without undergoing sig~ific~nt decomposition or volatilization. If the polymer is to be shaped as a melt with the modifier present, the latter should be stable at the melt temperature.
''~'. '' .

-- 1 -- .

. : .. ",',' ~.' ' ' ' ' ' '~ '' '," . " ' ~: ,, , , . , ! ' :
' ' ' ' ' ' : '; ' ' ....

~05~616 This requirement is particularly stringent for polyamides, aromatic polyesters and polypropylene which are usually heated to temperatures of between 250-300C. prior to being extruded. Comparatively few monomeric organic compounds can withstand this amo~mt of heat without undergoing significant volatilization or decomposition.
In those instances when a white or colorless product is requiredJ any significant discoloration resulting from decomposition of the polymer or the modifier will render the product unacceptable. Additionally, the prior art techniques ~or incorporating modifiers within a fiber may not be feasible if the process is detrimental to other desirable properties or to the dyeability of the fiber.
It has now been found that many of the short-comings inherent in prior art methods for modifying fiber properties by the use of relatively low molecular weight liquid or solid additives can be avoided or significantly reduced by applying these additives in liquid, solubilized or dispersed form to the fiber prior to or concurrently with a drawing operation wherein the draw ratio employed is between about 2:1 and the breaking elongation of the fiber.
This invention concerns an~improved method for achieving long term modification of one or more properties exhibited by fibers prepared from synthetic organic thermoplastic polymers by treating the surface of said ~
fibers with a liquid comprising one or more liquid, ~;
solubilized or dispersed modifiers for enhancing at least one property selected from flame retardancy, dyeability, ,~ ;
,:
. .

6~L6 resistance to mildew, soiling, degradation by heat or light, and accumu lation of static electrical charges wherein the improvement resides in treating *he fibers with said liquid prior to or during the drawing oper-ation, employing a draw ratio from about 2:1 to the break elongation for :
the fibers, and applying an efficacious amount of said modifiers, which typically is equal to between 1 and 20% based on the weight of the fibers.
Preferably the liquid is applied immediately prior to or during drawing of the fibers.
The type of modifiers which can be employed in the process of this invention include liquid and solid compounds selected from those classes of ,,' ~, ' ~ .. , . ' . .

1C1 51~6 modifiers which are conventionally employed for treating textile fibers.Examples of suitable modifiers include:
Dye receptors such as carboxylic acids, sulfonic acids, and amines or salts thereof;
Flame retardan~s such as halogenated hydrocarbons, inorganic anti-mony compounds, and organophosphorus compounds;
Anti-static agents such as fatty carboxylic acids containing be-tween 10 and 20 carbon atoms, quaternary ammonium compounds, and polyalkylene glycols;
Stabilizers for inhibiting degradation by heat and/or light such as organotin compounds and organic phosphites, e.g. tris-nonylphenyl phosphite;
Mildewcides such as organotin, organoantimony and organomercury com-pounds, halogenated phenols, organic copper compounds and the copper and zinc salts of the naphthenic acids;
Agents for killing, controlling or repelling a variety of undesir-able organisms, including fungi, bacteria, rodents, mollusks and insects;
Ultraviolet stabili~ers containing conjugated double bonds, partic-ularly benzotriazoles and antioxidants such as hindered phenols.
A summary of the various classes of modifiers that are conventional-ly applied to textile fibers is contained in a text entitled ESSENTIAL FIBER
CHEMISTRY by Mary E. Carter (Marcel Dekker, Inc. New York, 1971).
The modifiers of the present invention can be undiluted, diluted, dissolved or dispersed using a variety of organic and inorganic liquids. The liquid should be relatively volatile to facilitate evaporation once the modi-fier has been deposited onto the fiber. Preferred liquids exhibit a boiling point between 50 and 200C. Alternatively, the higher boiling liquids can be removed by washing the fiber with a relatively low boiling solvent for the liquid.
In addition to being a solvent or dispersant for the modifier at 30 the desired concentration level, the liquid vehicle must be a non-solvent for the polymer from which the fiber is formed and should not adversely ;
affect the desirable properties of the fiber.

~ -4-~ ; '.
- , ~;
.. . ..

: ~ . : . ~:, . . .. .

~at516~6 Suitable liquid vehicles include water, liquid aliphatic or aromatic hydrocarbons containing between 5 and 12 carbon atoms, halogenated hydrocar-bons, alcohols, liquid carboxylic acids~ aldehydes and ketones, all of which contain between 1 and 10 carbon atoms, preferably between 1 and 8 carbon atoms.

-~a-.~ , .
, ~S~l616 The present process for modification of fiber properties is applicable to fibers formed from all types of synthetic thermoplastic fiber-forming polymers which are capable of being drawn, i,e. irreversibly lengthened to at least twice their as-extruded leng~dl. Suitable fiber f.orming polymers includes:
Polyolefins, exemplified l-y polyethylene and polypropylene;
Polyesters derived from one or more diols, such as ethylene glycol cm d one or more aromatic or aliphatic dicarboxylic acids. Dicarboxylic acids containing 4-10 carbon atoms and diols containing 2-8 carbon atoms yield high molecular weight polyesters wherein the repeating units are joined by ester linkages (-0-C-). Alternatively, O
the anhydrides of the acids or esters derived from reaction of the acids with lolr molecular ~eight alcohols, e g. methanol, ethanol, and propanol, can be employed in place of the dicarboxylic acids. Polyesters can also be prepared using -hydroxy acids and cyclic derivatives thereof, e.g.caprolactone;
Polyamides derived from the aforementioned dicarboxylic acids or suitable derivatives thereof and dic~mines.
Suitable polyamides include poly (hexamethylene adipamide) and poly (hexamethylene sebacamide), Polymerized amino acids and cyclic derivatives thereof, e.g. caprolactam, are also suitable;
Vinyl polymers, including those derived from vinyl chloride, vinyl esters of carboxylic acids, vinylidene chloride, styrene and copolymerizable mixtures of one or more of these compounds; ~

~.
_ 5 _ ~L~S~6~6 Acrylic polymers, including polymerized esters of acrylic and meth-acrylic acids, acrylonitrile, acrylamide and copolymers thereof.
Polyurethanes prepared by reacting polyfunctional isocyanates with one or more compounds containing hydroxyl groups exhibiting labile hydrogen atoms.
It is to be understood that this invention is also applicable to fibers prepared from copolymers belonging to one or more of the aforementioned classes of synthetic polymers, e.g. poly (amide-esters), and copolymers derived from a combination of acrylic and vinyl compounds.
; The process of this invention comprises treating thermoplastic fibers prepared using polymers selected from one or more of the aforementioned classes with a liquid composition consisting essentially entirely of one or more liquid modifiers or solubilized or dispersed solid modifiers. The liquid composition is applied during or prior to the drawing process, which consists of irreversibly elongating the fibers to between about twice the as-spun length to just below the breaking elongation. Preferably the modifier solution is applied as the fibers are being drawn, since this has been shown to -opti~ize the desired properties imparted to the fiber. Alternatively, the modifier can be applied prior to drawing, for example as a spinfinish which may be either sprayed on the fibers or applied by wicks, wheels, or other wiping contacts as the fibers emerge from the spinnerette.
This invention also provides an improved flame retardant textile denier fiber exhibiting a limiting oxygen index greater than 25.0 wherein the polymer comprising said fiber is thermoplastic and is selected from the group consisting of polyesters, polyamides and polyolefins and wherein at least a portion of the flame retardancy exhibited by the fiber result from the -presence within said fiber of between 1 and 20%, based upon the weight of said fiber, of at least one compound selected from the group consisting of: a) hal-ogen-containing organic esters of phosphoric acid, b) chlorine- and bromine-containing organic phosphonates, phosphinates, phosphines and phosphine oxides wherein all hydrocarbon and alkoxy radicals bonded to the phosphorus atom con-tain between 1 and 12 carbon atoms, c) triorganotin compounds of the general formula R3SnX or (R3Sn)2Y, d) quaternary ammonium compounds of the general formula R4NX, e) quaternary phosphonium compounds of the general formula R4PX, 1~5~ 6 f) organoantimony compounds of-the general formula R2SbOCR' wherein R and R' represents an aIkyl, aryl, aralkyl or alkaryl hydrocarbon radical containing between l and 12 carbon atoms, X represents a monovalent radical selected from :
the group consisting of halogen, hydroxyl, mercaptide (-SR') and carboxylate R'C-O- and Y represents oxygen or sulfur, g) halogen-containing organic thiophosphoryl chlorides, h) chlorendic anhydride and i) dibromoeopentyl alcohol, wherein said compound has been incorporated within said fiber during the drawing of the fiber.

... ..

- 6a -B

,, .

~5i~6~L6 Drawing iB desir~blc for cry6tallizal~1e thermoplastic polymers since it has been shown to increase the tensile strength and optimize other physical properties exhibited by these materials. This ef~ect is believed due to an elongation and reorientation of the polymer chainæ that comprise the fiber from their original more or less random, coiled ~orm in the as-spun fiber toward a direction that i~
more nearly parallel ~o the longitudinal axis of the fiber.
The drawing operation can be accomplished using methods that are well known in the art. A comprehensive treatment of this subject appears in volume 8 of the Encyclopedia of Polymer Science and Technology, edited by H. Mar~ and Nc Gaylord and published by Interscience Publishers (1968).
Application of the modifier prior to or during ¦ drawing can be accomplished by passing the fiber through a trough or other suitable vessel containing the modifier.
Alternatively, the liquid modifier can be applied using a roller or a wick which is in contact with both the fiber and the modi~ier. The modifier can be applied at any time prior to or during drawing, however ~rom a practical viewpoint it may not be desirable to allow the modifier to remain on the fiber for substantial periods of time prior to drawing, since this may initiate crystallization that could make the fiber di~fcult to draw.
Solid modi~iers are employed as solutions or uniform dispersions wherein the modi~ier concentration can be between 3% by weight and the concentration of a saturated solution at the desired temperature. Liquid modi~`iers can be employed without any diluen~ or at concentrations ~rom ll~S161~;

99+% to 1% or less, depending upon the fiber proccssing conditions such as drawing rate and the amount of modifier to be transferred to a given length of fiber.
The following examples demonstrate preferred embodiments of this invention and should not be interpreted as limiting the scope thereof either with regard to types of modifiers or fibers.

Yarns of undrawn poly~ethylene terephthalate) filaments containing

2% by weight titanium dioxide as a delusterant were treated as described in the accompanying table. The yarns contain 68 filaments and exhibited a total denier of 1368. As the filaments emerged from the spinnerette, they were sprayed with an ambient temperature spinfinish solution of specified concen-tration where applicable and then wound on conventional textile bobbins.
The resultant yarn was then drawn by passing it sequentially ~f ' .
.; . , - . : : , : ....................... :

' , '. ~ , : .

~051616 around a draw roll rotating at a surface speed of 50 feet (15.2 meters) per minute, through a rectangular metal container measuring 28 inches (71 cm.~ long, 3 inches (7.6 cm.) high, and 2.5 inches (6.3 cm.) wide and equipped witll a filament ~uide at either end thereof, around a snubbing pin and then around a second draw roll rotating at a surface speed of 200 feet (60.8 meters) per minute, thereby achieving a draw ratio of ~X. The metal container was partially filled with either a solution containing 50 g. of triphenyl phosphine oxide (TPPO) per 100 c.c.
o f isopropanol or a quantity of pure isopropanol. The liquid in the container was maintained at a temperature of 70C. The filament guides at either end of the container served to keep the yarn below the level of the liquid during the passage of the yarn through the container. After being processed~ the yarn was wound onto a U-shaped metal frame measu~ing 2 inches (5.1 cm.) in widtll and 5 inches (12.7~c~.) in lengtll. The treated yarn samples were then laundered by placing the frames ~
containing the yarn in a container of hot detergent solution ,!
(25 grams of a commercial laundrr detergent in one quart of water at a temperature of 75-80C.). The container was then covered and shaken for 1.5 hours. The test samples were then rinsed in ambient temperature water for one hour, after which the washing and rinsing procedures were each repeated two times and the yarn samples then allowed to dry in air.
The Limiting Oxygen Index (LOI) was determined in accordance with ASTM (American Society for Testing of Materials) test procedure 02863~70 by placing the yarn samples wound on the aforementioned U-shaped metal frames in a vertically orientated Pyrex (Trade Mark) glass tube exhibiting ~n inside diameter of :.. . ' . ~ ' : ': :, !: , ., .:.
,' . . ,~ ,. . .. . . . .

~: 11 lOS1616 1 .

¦ 3 inches (7.5 cm.) and a height of 17~8 inches (45 cm.). Th~
¦ tube had a ~ed of glas6 beads located a~ the bottom thereof and ¦ a clamp for the aforementioned metal frame located above the ¦ glass beads, by means of which the frame is maintain~d in a ¦ vertical position with respect to the longitudinal axis of the tube. Pure oxygen, pure nitrogen or a specified mixture of these two gases i9 introduced at the bottom of the tube by allowing it to flow up through the glass beads. The flow of gas is controlled and monitored by means of suitable valves and flow meters. A flame is then touched to the top of the wound yarn sample, while the gas is flowing through the tube and the minimum oxygen concentration required to support combustion is noted.
The limiting oxygen index is then calculated using the ~ollowing formula:
Limiting Oxygen Index = (L.O.I.) = ~

~herein [ 2 ] represents the minimum oxygen concentration required to support combustion and ~N2] represents the corresponding concentration of nitrogen.
Specimens exhibiting a limiting oxygen index vaLue less than 21.0 will burn readi1y in air, while those exhibiting a value greater than 21.0 will b~rn sluggishly, if at all 9 in air.
The treabments applied to each of the yarn samples and the resultant limiting oxygen index values are summari ed in the following table. For purposes of comparison an undrawn yarn to which no spinfinish had been applied exhi-bited a limiting oxygen index of 22.3. This yarn wa~ not laundered.

:

- 1~516~6 . ~
C~

o~ oo o o ~ U~ o ~ ~
Z
~ ~

:~:Z~ bO
, ;~i ,~ ~ O ~ O a l ~ O
~ ~ : ::

, b ' ~ . '~ 'X.~
E~ ~ O
~` H H H
H H a) ~ . ,1;
E~; <' o t o O O ~ ~bO
Q H ~4 Z; P ~ 1 E~
E~ ~
r~
Z ~ ~ '.

U~ ~ ¢ ¢ ¢ ,~ O
:I: H H H ~ td ~ E-I ~ 1 ~ Z ~ rl h ~ ~ Z 2 P. ~ ~ o ~
H ~ ~ O

~ ¦ ~ N ) ~ r) : tn ~z;

.. ':' ~ ' ' ' . ':' ,.,".. "'' ':" ' . .

-~ I i~S~6~

I E,YNMPI.E 2 I
Yarns of poly(ethylene terephthalate) ~ilaments ¦were spun, drawn, and laundered as described in Example 1 ¦with the only dif~erence being that no spinfinish was ¦used and the liquid in the metal container consisted of a S ¦solution containing 50 g. of tris(294,6-tribromophenyl) ¦phosphate per lO0 c.c. of toluene. The limiting oxygen index f the laundered yarn was 29Ø This procedure was repeated using yarn spun from an ethylene terephthalate polymer which was l modified to incorporate sites having an affinity ~or dispersed dyes. The ~iber did not contain a delusterantO The modifier was a solution exhibiting a concentration of 12 g. of tris(2,476-tribromophenyl) phosphate per lO0 c.c. of toluene. The modiier temperature was 70C. and the yarn exhibited a limiting oxygen index value o 32~8.
Undrawn yarns of polycaprolactam and polypropylene when processed using the procedure described in the first aragraph of this example exhibited L~O~Io value~ of 27.2 nd 24.7, respectively.

.....
The delustered poly(ethylene terephthàlate) yarn escribed in Example 1 was dra~n using the rectangular container and drawing conditions specified in Example l, without any pinfinish tre~tment. About one liter of each modifier was nitially present in the container. The compoæition o~ the odifier and the L.O.I. values obtained following laundering are ummarized in the following Table II. In alL inst~nces the emperature of the solution in the rectangular container was etween 40 and 50C.

' ..

;:)l~;~
¦ Tnble II
F.x<~mple Modi~ier L.O.I.
¦ No. ~10cli~ier Solllt~ Solvent Value I ~
; ¦ 3 T2CP2 (1)(32 ) toluene (500c.c.) 28.9 I 2 2 (2) ¦ 2 2 toluene (67Sc.c.) 28.7 T BP (73g.) 5. BTBPTC ( 3 ) ( 30g./300c.c. xylene 2~.3 of solution) 6. Tris(2j3-dibromopropyl acetone 26~7 phosphate) (lOg./lOOc.c.
of solution) 7. Chlorendic anhydride ( lOgo/ methanol 28~0 lOOc.c. of solution) 8. Dibromonepentyl alcohol toluene 28.7 (lOg~/lOOc.c. o~` solution) Notes: l-tris(2,4,6-trich1orophenyl) pho~phate 2-tris(2,4,6-tribromoph nyl) phosph~te

3-bis(2,4,6-tribromophenyl~ thiophosphoryl chloride E~MPLE 9 A 60 inch (152 cm.j length of the delustered poly (ethylene terephthaLate) carpet yarn described in Example 1 was completely immersed in undiluted bis(tri-n-butyltin) oxide and then dra~n by irreversibly stretching the yarn to a length of 20 feet at ambient temperature~ The drawn yarn was then wound on a U-shaped metal ~rame, and the wound yarn sample treated successively with acetone ~nd ~ater to remove the organotin compound from the ~iber surface. After exposure to ambient conditions or three days the yarn exhibited a faint odor characteristic o~ the organotin oxide and upon ana~ysis was ound to contain 2.16 weight ~ tin, which is equivalent to 12% o~ the organotin oxide. This indicates that fibers treated with biocidal agents such as triorganotin compounds in accordance with the present invent;on should , . . , . . : . ~ -. , ,., . ~ . .

~ l~S~ 6 ef~ecti.vely inhibi~ the development o~ v~riou~ microorg~nisms ¦ including mildew and gram positive bacteria.
Poly(ethyLene terephthalate) yarn treated as described l in the irst paragraph of this exa~ple using tri-n-butyltin S ¦ benzoate in place of the tr~organotin oxide exhibited a tin content o~ 1% by weight after being laundered 8~ described in Example 1.
FiberR which have been modified under the condition~
de6cribed in the foregoing specification and appended claims can be employed for a variety o~ end ~pplications, some o~
which were not hereofore possible using unmodified materials.
In addition to providing long term enhancemen$ of desirable ~iber propertie~ including flame r~tardancy, dyeability and resistance to degradation during exposure to heat or ultraviolet radiation7fibers which incorporate biologically active compounds can be employed in various ~orm~, including monofilamen~s, yarns, tows, staple~ and woven or nonwoven ~abrics to inhibit or repel undesirable organisms including microorganisms and larger life form8 such as in~ect~ rodents and molLusk~ in locations where these organisms are prevalentO Triorganotin compounds wherein each o~ the hydrocarbon radicals bonded to the tin atom contain between 1 and 12 c~rbon atoms conætitute a pre~erred class of biogically active compounds that are .
readily incorporated into ibers at concentration~ o~ be~ween about 0.5 and 20~ by weigh~, depending upon processing conditions and whether the modi~iers are liquid or ~olid at ambient temperature. The particular triorganotin derivative employed as a m~difier~ ~or example oxides, carboxylates~ haLides and sul~ides, will usually be determined by practical considerations such a~ cost, availability, solubility (for solid materials) ~ ' ' ' ' 105~

and ease of incorporation into the fiber structure. It has bcen demonstrated that the type of anion has only a minor efEect on the biological activity oE a pnrticular trioganotin radical, so long as the anion itself does not exhibit significant activity of its own.
Other use~ul biologically active compounds that can be employed as modifiers to prepare the p~oducts of this invention include~
Organomercury compounds Organocopper compounds Organophosphorus compQunds Fibers and shaped articles incorporating exposed ibers that have been modified with biologically active compounds can be placed in areas which are susceptible to attack by bacteria, insects, rodents, and other undesirable organisms.
¦ EXA~LE 10 . . .
This example demonstrates the efficacy o~ modi~ied poly(ethylene terephthalate) fibers as an inhibiting agent for Aspergillu~ niger.
A yarn of poly(ethylene terephthalate) ilaments (1368 denier, 68 filaments) containing 0.15% by weight of titanium dioxide as a delusterant was scoured for 15 minutes to remove the spinfinish. me scouring medium was an aqueous solution containing 1 g~ oE sodium carbonate and 0.5 g~ of sodi~m -N- aleoyl taurate (the sodium salt of N-oleoyl -2-aminoethane sulfonic acid) per 100 C~Cr Of solution9 and was maintained at a temperature of 50C. The scoured yarn was rinsed with water and then dried in air at ambient temperature.

- 15 ~

: ` ~L~S1616 A ten ~oot (3.1 meter)-long ynrn ~nmple was pa~ed at a rate of about 1 ~oot (0031 meter) p~r ~econd ~hrough a U-shaped tube containing an aqueous soLution which in turn contained 40~ by weight of diisobutylpheinylethoxyethyl dimethyl benzyl ammonium chloride monohydrate, 14.9% of i~opropanol and 503%
o~ tri~n-butyltin benzoateO The yarn,designated as sample ~, was then drawn to 2.3 time~ its original length. The drawing was performed in air at ambient temperature, after which the yarn was rinsed with water ~nd laundered as described in Example 1 using a commercial household laundry detergent, then dried at 60C. for two hours. The ~oregoing procedure was repeated with ~wo additional yarn samples, each of which wa~
treated with one of the following materials prior to being drawn:
bis(tris-n-butyltin oxide) as a soLution in isopropanol containing 20 g~ of oxide per 100 c.cO of solution (Sample B);
diphenyl antimony 2- ethy~ hexoate as a solution in isopropanol containing 10 g. of the antimony compound per 100 c.c. of solution. (Samp~e C)~
Following laundering a 4 inch (10 cm~ long ~egment from earh of the foregoing three yarn samples was placed in a petri dish containing potato dex~rose agar which had been inoculated with AspergilLus niger organisms. The agar was inoculated in the molten state 7 and then poured into the petri dishes. The yarn samples were placed in ~he petri dish when the agar solidified, a~ter which the dishes were covered and maintained at 30 ~ 1Co for two days~ Any æone of inhibîtion, i.e. area of zero growth, surrounding the ~iber was measured. An untreated poly(ethylene terephthalate) yarn was empLoyed a~ a control. The following results were ob~erved:

; ' ' ' ' ~ ~ ~ S~ ~6 ¦ SAmple Modi~ier ~idth o~ Inh~bition I Zone ~in millimeters) ¦ Control None None (agar completely overgrown) ¦ A quaternary ammoni~ 10-12 ¦ chLoride-orga~otin compound~
isopropanol mixture l B bis(tri-n-butyltin oxide~ 10-12 ¦ C diphenyl antimony 2-ethyl hexoate 5-6 Elemental analysis of the treated yarns yielded the ollowing results, all percentages being b~ weight.

Sample A - 0~31% tin, 0.25% nitrogen Sample B - 3.99% tin Sample C - 2.69% antimony These data indicate that sub6tantiaL amounts of modifiers were retained following laundering~
The ~oregoing proceduxe ~or preparing sample A wa~
repeated, with the exceptions that a) the ULshaped tube contained water and b) the drawn yarn was passed through a U shaped tube containing the modifier, after which the yarn was rinsed with water~ laundered using only 1 trea~ment with the detergent ~olution, and rinsed again as described in ExampLe 1. Upon analysis the yarn was found to contain 0.023% tin and no nitrogen. These data indicate that substantially no modifier was re~ained when the yarn iæ treated with the modifier folLow-ing ~he drawing operation.
EXAMPIE lL
This example demonstrates treatment o~ poly(ethylene terephthalate) yarn with an anti-static modi~ier.
An undrawn yarn of poly(ethylene terephthalate~ fibers (1368 denier, 68 filaments) was treated with a solution contain~
ing ~0 g. of dimethyl di(hydrog~nated ~allow~ ammoniwm chloride, 120 c.c. isopropano~ and 10 c.c~ water~ The ~olution was maintained at a temperature o 40C. and was nppli~d to the , . . ~ .

lOS1616 yarn prior to the drnwin~ operation as described in Rxample lO~
The ten foot (3.1 meter)-long yarn sample was drawn in air at a~bient temperature to three times its original length, washed briefly using a 12:1 weight ratio mixture of i~opropanol:
water, then laundered and dried as described in Example l. The yarn was found to contain 0.44-0.4G% by weight of nitrogen (equivalent to 3% ~y weight of the modifier).
The anti-static property of the yarn was evaLuate~
by placing a sample of the modified yarn and an unmodified control in a desiccator containing phosphous pentoxide a~ a dehydrating agent. After remaining in the desiccator for 18 hours, both yarn samples were weighed and then transferred to a desiccator toge$her with a saturated aqueous solution of I sodit~ chloride which was in contact with solid sodium chloride.
This combination is known to yield a relative humidity of 30%
in a closed container at a temperature of 18C~. The yarn sample~ were not in contact with the solution. After remaining in the desiccator for 18 hours the yarns were again weighed I to determine the weight gained during storage in the desiccator.
¦ The yarn treated with antistatic agent exhibited a 2.2% weight gain and the untreated control gained only 0.0016%. The amount of weight gained was due substantially completely to adsorption of water, which is proportional to the level of anti-static l property exhibited by the yarn. The test data indicate that a significant amount o~ the anti-static agent applied to the yarn was retained following lat~dering.

.

1~)5~6~6 SUPPLEMENTARY DISCLOSU~E
The amount of liquid modifier that can be incorporated into the fiber is a function of numerous variables including particle size of the modifier~ temperature of the modifier, contact angle between the fiber, the modifier and air.
In the case where the liquid modifier is a liquid compound or a mixture of liquid compounds, the maximum amount of liquid modifier that can be incorporated into the fiber is achieved when:
(i) the contact angle between the fiber surface and the liquid modifier is less than 90 .
~ii) the temperature of the modifier is below the effective glass transition temperature of the fiber.
(iii) the liquid modifier is a non-solvent for the fiber.
When the liquid modifier is a solubilized or dispersed solid com-pound, the amount of liquid modifier than can be incorporated into the fiber is maximi~ed when:
(i) the particle size of the modifier is less than two microns.
~ii) the contact angle between the fiber surface and the liquid modifier is less than 90 . ~ -~iii) the temperature of the modifier is below the effective glass transition temperature of the fiber.
(iv) the liquid modifier is a non-solvent for the fiber.
Under these conditions, modifier concentration of between 0.5 and 2% by weight can be achieved.
Thus~ the inven-tion provides a method for permanently and uniformly incorporating between 1 and 20~ by weight of an additive into an undrawn or partially drawn fiber formed from a molten polymer selected from~the group consisting of polyesters, polyamidesg polyesteramides, polypropylene and high density polyethylene, the method comprising cold drawing said fiber at a draw -- 19 -- .i -1~516~
ratio of between 2:1 and the breaking elongation of the fiber to achieve a localized reduction in diameter that occurs while the fiber is immersed in a liquid medium containing said additive as a solution, dispersion or emulsion, wherein 1) the maximum particle: size of a dispersed or emulsified addi-tive does not exceed two microns;
2) the medium is a non-solvent for the undrawn fiber, 3) the contact angle between the liquid medium and the fiber sur-face is less than 90 ;

4) the temperature of the medium is below the effective glass .
transition temperature of said fiber when in contact with the medium; and ~ .

5) the liquid medium displays the ability to penetrate into and fill a network of microvoids that are formed as the fiber is being drawn.

: ,

Claims (5)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. An improved method for treating fibers prepared from poly (ethyl-ene terephthalate) by applying to the surface of said fibers a liquid modi-fier which is a solution of triphenylphosphine oxide in isopropanol wherein the improvement resides in applying said liquid modifier prior to or during the drawing operation, employing a draw ratio about 4:1 to the break elongation for the fibers, and incorporating an amount of said triphenyl-phosphine oxide equal to between 1 and 20% based on the weight of the fibers.

CLAIM SUPPORTED BY SUPPLEMENTARY DISCLOSURE

2. A method for permanently and uniformly incorporating between 1 and 20% by weight of an additive into an undrawn or partially drawn fiber formed from a molten polymer selected from the group consisting of polyesters polyamides, polyesteramides, polypropylene and high density polyethylene, the method comprising cold drawing said fiber at a draw ratio of between 2:1 and the breaking elongation of the fiber to achieve a localized reduction in diameter that occurs while the fiber is immersed in a liquid medium containing said additive as a solution, dispersion or emulsion, wherein 1) the maximum particle size of a dispersed or emulsified additive does not exceed two microns;
2) the medium is a non-solvent for the undrawn fiber,

3) the contact angle between the liquid medium, and the fiber surface is less than 90°;

4) the temperature of the medium is below the effective glass transition temperature of said fiber when in contact with the medium; and

5) the liquid medium displays the ability to penetrate into and fill a network of microvoids that are formed as the fiber is being drawn.