CA1169206A - Lubricant compositions for finishing synthetic fibers - Google Patents

Abstract

Abstract LUBRICANT COMPOSITIONS FOR FINISHING SYNTHETIC FIBERS

Lubricant compositions for finishing synthetic fibers which exhibit improved thermal stability and low-fuming characteristics are provided which contain 50 to 90 percent by weight of a thermally stable lubricant and 10 to 50 percent by weight of an emulsifiably effective surfactant having the formula:
R - 0 ?Aa Bb? H
Wherein R is an alkyl having 6 to 14 carbon atoms, A is oxypropylene groups, B is oxyethylene groups, a is an integer having values of about 4 to 15, and b is an integer having values of 5 to 10.
S P E C I F I C A T I O N

Description

LUBRICANT COMPOSITIONS FOR FINISHIN~ SYNETHETIC FIB~RS
BACK~ROUND OF THE INVENTION

Thi~ invention pertains to lubricant composition~ for finishing 6ynthetic fiber~ and more par~icularly to 6uch compo~itions containing propylane oxide~ethylene oxide block co~polymer adduct6 o~
aliphatic monohydric alcohols having 6 to 14 carbon atoms as emulsifier~.
~ uring the conventional manufacture of ~yn~hetic continuous filament yarn, ~uch as polyamide~
and polye~ters, ~he yarn i8 treated with a lubricating compo~ition usually in the form of an aqueous emul~ion.
Such compo~ition~ normally contain a lubricant, such a~, fatty acid e6ter~, hydroc2rbon oil~, and~or ~egetable oils, an anti-static agent~ an anti-oxidant and an emul~ifier ~ystem to render the luhricant compo6ition water emul~ifiable. The complete lubricant composition 6hould serva the ~roce6sing and manufacturing needs of the f iber producer a~ well a~ the u~er of the synthetic yarn. The lubricant composition provides controlled lubricity (fric~ional properties) during yarn pr~cessing by high-~peed machinery, pro~ide~ proper yarn in~ra-frictional properties, and protects ~he yarn from damage during manufacturing and proce~ing handling requirements.

:~ ~&~2~6 D~13055 For high-speed and high-~emperature yarn proces~ing, such a6, hot-~tretching, bulking, cximping and texturizing, the lubricant compo~i~ion mu~t function adequa~aly at both ambient. and high temperature~. In addition to the aforementioned requirements, the lubricating compo~ition must exhibit ~pecial qualitie~
for high-temperature proces~ing, that is, tha composition should be sufficiently stable so as no~ ~o ~moke or fume nor re~ult in the formation of varni~hes or re in~ upon deposition onto machinery-heated 6urface~. In order to meet the thermal requirement~, each component of lubricating compo~:ition should posse~s the neces~ary thermal ~tability. However, in actual practice only ~ome of the components ~ul~ill the thermal prerequisi~es. In par~icular, ~ome emul~ifier systems fail to meet ~he thermal sta~ility standards becau~e of the chemical make-up of ~he emulsifier or emulsifiers which i~ de6igned to produce stable aqueous emulsion~ of lubricant composition. High fuming or smoking andJor varnish formation upon expo~ure to high temperature also are normally encountered with conventional ~urfact.ant used ~o formulate the emul~ification sy~tem6. In addition, the nece~ity of employing more than one ~urfactant to achieve ~table aqueous emulsions complicates the ~ituation.

~ ~6920~ ~-13~55 Commonly u~ed ~urfactants ~uch a~ alkylphenol ethoxylate~, ~orbitan ethoxylate e~er6, (hydrolyzed) vegetable oil ethGxylates, alkyl alcohol ethoxylates, fa~ty acid e~hoxylate6, and the like, do not meet all the requirements of an emulsifier in a lubricant composition for ~ynthetic yarn. For example, the sorbitan ethoxyla~e e~ters and the (hydrolyzed) vegetable oil ethoxylates, although good emulsifier~, produce high amoun~6 of thermo-oxida~ion varnishe~ and are high-vi~co6ity component6, a factor which i8 unde~irable due to the direct relationship between vi6cosity and fric~ion. The alkyl alcohol ethoxylate~
produce large amoun~ of ~moke and require complicated combinations of surfactant~ to yisld ~table lubricant compo6ition emul~ions. The alkylphenol ethoxylates are good low-fuming emul~ifier~, but create unacceptable varni~hes. Compared to the other nonionic ~urfactants li~ted above, the alkylphenol ethoxyla~e~ display the best overall properties a~ lubricant component6 for ~ynthetic yarn. Moreover, in Canadian Patent No.
1,122,96~ ued May 4, 1982, l~bricant compositions .
containing a ~articular propylene oxide/ethylene oxide block copolymer adduct of alkylphenol i~ shown to exhibit acceptable high temperature and emul~ifier , . . .

characteristics. However, it ha~ been found that ~uch 6ur~actan~6 have a vi~co~ity that may be le~s desirable for ~ome applications and it m~y al~o be de~irable from an environmental standpoint ~o employ ~urfactant~ that are not phenol containing.
It i8 therefore an object of thi~ invention to provide ~ynthetic yarn lubricant compo~ition~ ~ontaining emul~ifier~ which di6play the proper thermal ~tability, low fuming characteri~tic~ and emul~ification ver~a~.ili~y. It i~ a further object of thi6 invention to provide a single non-phenol-containing surfactant having acceptable high temperature stability and . .
,~ resistance to varni~h formation upon expo~ure to h0ated ~ur~ce~ and which vill emulsify conventional lubricant~
u~ed in high-temperature proce~ing of ~ynthetic fiber~.
A till further.object of thi6 invention i~ to provide ~urfactant~ which produce microemulsions with ~;~ conventional hiqh-temperature proces~ lubrisant~.
; An indication of the fumin~ tendencies of a : ~ub~tance is obtained by the measurement of the ~moke ,' point.
s.
SU~MARY OF THE INVENTION
The object~ of thi~ invention have been satisfied by a spin finish for ~ynthetic fibers con~i~ting e~6entially of:

2~

(A) about S0-90 percent by weight of a thermally ~table lubricant ~ele~ted from ~he grou~
con6isting of:
(1) e~ter~ of fatty acids ha~in~ 12 to 18 carbons and saturated aliphati~ alcohols having about 8 to 18 carbons:
~` ~2) triglyceride~ of fatty ~cids having 12 to 18 ~arbon Atoms (3~ e~ter6 of a polyhydric alcohol and an alkanoic acid having about 8 to 12 carbon atoms where the polyhydric al~ohol has ~he for~ula:

(R ' )--S~(CE~2 C)H )X
,' Y

wherein X i~ an integer having value6 o~ 3 or 4, R' i~ an alkyl hav;ng 1 to 3 carbon~, y is ~; an integer having value~ o~ 0 or 1 with the proviso that. when x = ~, y = 0: and (~) e~ters of dibasic fatty acid~
ha~ing 2 to 1~ carbons and saturated aliphatic alcohol~ having about 4 to 18 carbons:
(B) About 10-S0 percent by weight o~ a : surfactant having ~he formula:
-0-(A~Bb~ ~
wherein R i8 an alkyl having 6 to 14 carbons, A i6 ' ~ I

-CH -CH0-, B i~ -CH CH 0-, a i~ an integer having value6 of about 4 to 15, ~referably 5 to 130 and b i8 an integer having values of 5 to 10, pre~erably 6 to 9.
: The lubricants u~ed ;n thi6 invention are all commercially available. The e~ters of fatty acid~ are exemplified by 6uch e~ter~ a~ tridecyl stearate, hexadecyl ~tearate, dodecyl oleate, octyl linoleate, and the like.
Repre~entative triglyceride~ include natural triglyceride~, such a~ coconut oil, tallow oil, palm kernel oil, ca~tor oil, and ~he like.
Preferred e~ters of a polyhydric alcohol and an : alkanoic acid include trimethylolpropane tripelargonate, t~imethylolethane trioctano~e, pentaerythritol te~rapelargonate, and the like.
Thc surfactant6 of thi~ invention can be made by the reaction of propylene oxide and ethylene oxide with known aliphatic monohydric alcohols having 6 to 14, and preferably B to 12, carbon atom~. Alcohols which may be employed are those primary 6traight-and branched-chain alipha~ic monohydric alcohol6 which contain 6 to 14, and preferably 8 to 1~, ~arbon atom~ in the chain. Mixtures of the alcohol~ may al~o be u~ed.

: - 6 -.,,~ ,, ?s ~
,l :.

~92~6 Exemplary suitable alcohols are 2-e~hylhexanol;
n-heptanol: 2,6-dimethyl-1-heptanol: n-nonanol;
n-decanol; n-undecanol: 2,4,4 trimethyl-l-pentanol;
n-dodecanol and mixture~ thereof.
In a preferred embodiment, a typical aliphatic ~onohydric alcohol having 6 to 1~, and preferably ~ to 12, carbon atoms i~ converted to an alkoxide with potas~ium hydroxide followed by the addition first of propylene oxide to prepare a block o~ oxypropylene repeating unit6 at a temperature of about 100 to 150C
and a pre~sure of about 1 to 100 p8i~ followed by the addition of ethylene oxide ~o incor~orate oxyethylene block~ at a temperature of about 100 to 150C at a pressure of about 20 to 100 esig. Although the moles of ethylene oxide per mole of alcohol can vary from 5 to about 10, and preferably from about ~ to about 9, the number of molefi of ethylene oxide u6ed depend~ on the balance and combination of proper~ies that are desired.
It i6 preferred that the ratio of ethylene oxide to propylene oxide in the surfactant ~hould not be greater than about 2.5 or le~s than ~bou~ 0.3.
Preferred surfactants are liquids a~ ambient temperature6 having a melting point of about 15C or less and vi6cositie~ at 25C of 150 centisto~es or less.

1 ~9206 Although the range of lubricant in the ~pin fini~h can be about 50 ~o 90 weight percent of the total, it i~ preferred to use a range of about 60 to 80 percent. Corre~pondingly, while the surfactan~ can range between 10 and 50 percent of ~he total finish it is preferred to use 20 to 40 percen~. Stated ano~her way, the mole ratio of lubricant to surfactant aan vary feom about 9 ~o 1 to about 1 to 1.
For practical application of the spin ~inish to synthetic fiber6 they are u~ed a~ aqueous compo~ition~
containing about 10 to about 20 percent of the pln finish emul~ified in water.
A preferred ~urfactant according to thi~
inven~ion san be characterized a~ having~the follo~ing propertie6:
1. A ~moke point great~er than about 180~C.
2. A volatility at 200C of less ~han 12 percent per hour during a 5-hour test and a re6idue f rom the te~t which i~ a liquid.

3. A thin-film residue at 220C of le~s than 5 percent remaining after 24 hours which i6 a hot ~napy water removable ~tain.

4. A vi6cosity of le8~ than 200 centi6toke~, preferably le~s tha~ 150 centi~tokes at 25~C.

20~

5. A mel~ing point of le~6 than 15~C.

6. A cloud point (ASTM D2024-65) in a 1 percen~ aqueous 601ution greater ~han 5C but le~ than about 50C.

7. An emul~ification effec~ivene~6, when mixed with appropriate lubricant~, a~ mea~ured by the presence of a ~table emulsion at 25C la~ting for at least 24 hour~.
- The invention i~ further defined in ~he examples which follo~. All par~ and percentagei are by weight unle~s otherwise ~pecified.

EXAMPLE I

Preparation of 2-Ethylhexanol 12.6 PO (Propylene Oxide) - _~B.5 EO (Ethylene Oxide) Block PolYmer Preparation of S~arter Alkoxide . In a typical experiment, 393 g. (3.0 molei) of i 2-ethylhexanol wa~ charged to a 2-liter, 4-necked, round-bottom flaik equipped with a stirrer, thermowell, nitrogen purge, and heating mantle. The alcohol was heated to 40C with stirring, and the system was nitrogen-purged for 15 minutes. Flake 85 percent potas~ium hydroxide, 6.4 gram~, was added and the mix~ure was heated to 100C until the KOH di~solved. In order to remove the water from the reaction. a refl~x _ 9 _ ~i ,, ~ ~9206 D-13055 still head wa6 added to the appara~us and the pressure was reduced to 10 mm Hg. ~fter She water wa~ removed at 100C over a one-hour period, the product wa~ cooled and, while maintaining a nitrogen purge on the reactor, a sample, 15 gramG~ was removed for water analysis.
Water was determined using the po~entiometric Karl Fischer method. A value of 0.006 percent waR obtained.

Addition of Propylene Oxide (PO~
The starter alkoxide was charged to a 1.5 gal.
stirred stainle~6 steel reactor in a nitrogen atmosphere. After closing the ~ystem, 5 p6ig o~
nitrogen was put on the reactor and the content~ heated to 100C. The pressure was then adjusted to 10 psig and propylene oxide, which was previously added to the weighed ~eed tank, was fed to the reactor using a Lapp pump. Thi~ pump wa~ de&igned to re~ycle liquid back into the pump feed line if the reactor did not need oxide ~or any reason. Propylene oxide, 2080 ~rams (35.9 ~oles3, wa~ fed at 110C and the pressure was allowed to increa~e to 60 ~8ig with manual control of the 6ystem.
Once the reaation lined out at these conditions, tbe ~ystem was placed on automatic control with pre~sure controlling oxide feed. After the PO addition was complete - a~ter about 4 hour& - the ~yBtem was "cooked , .

D-13~55 out" at 110C for 3 additional hours or to a reduced con~tan~ ~re6sure to in6ure complete P0 reaction and cooled.

Addition of ~th~lene Oxide (E0) After 6tanding overn;ght, the reactor was pre&~urized with nitrogen to 15 p~ig and heated to 110C. The pre6sure wa6 adjusted to 20 p~ig and ethylene oxide, taken from the we;ghed feed tank~ wa6 fed carefully to the ~y~tem. E0 wa~ fed at 110C and 60 p8ig to the reactor un~il the product had a cloud point of 25C. The ethylene oxide wa~ cooked out ~or 2 hour6 after addition wa~ complete, and the product wa6 cooled and di6char~ed from the reactor in a nitrogen atmo~phere to a container containing glacial acetic acid. one ml of ~lacial acetic acid i6 used for every gram o~

, . -: pota6~ium hydroxide ini~ially added.
(~

The al~vxylate product was neutralized in the laboratory in the 6ame apparatus u~ed to prepare the starter alcohol with additional glacial acetic acid under a nitrogen atmo~phere to a pH of 6.8 to 6.5; pH
paper in the range of 6 to 8 wa~ u6ed for the mea6urement. The product was then ~tripped at 100C and ., ~ 11 -a pressure of one mm Hg for one hour to remove any unreacted oxide6. ~ormally, less than 0.5 weight percent was removed. A clear, colorles~ product was obtained a~ ket~le residue having a molecular weight of 1235 which was evaluated a~ a high-temperature ~urfactant in heat-stable finishe~ for texturi~ing polyester yarn.

Evaluation of the Produc~
The following test ~ere run on the alcohol ~lkoxylate to demonstra~e sati6~actory heat-s~able pxopertie~:

Smoke point ~00UC

Volatility 7.2 percent per ! hour leaving a brown liquid residue Thin-film re~idue 1.6 percent re~idue . on 6tainle~ steel which was a yellow ¦ varnish, hot 80apy water removable Other phy~ical propertie~ were:

Vi~co~ity 139 ~ks ~centi~tokes) a~

Specific Gravity 1.003 at 25C
Melting Point <-10C
r Cloud Point 25C

2 ~ ~

Vi6~0sity wa~ determined with a Cannon-Fen~kQ
viscome~er. Smoke point wa~ determined by placing 30 ml. of product in a 50 ~1. gla~s bea~er and heatin~ the beaker on a hot platQ at a rate of 15C/min. U~ing a thelmometer immer6ed in the product and a black background, the smoke point i~ recorded at the temperature when the ~irst smoke become~ visible.
Volatility te~ts were carried out in a forced-air oven at 200~C for 5 hour~ u~ing a lo g. sample in a Pyrex di~h having an area of 20 cm .
Residue te~ts ~ere carried out on a hot plate at 220C for 24 hour~ using an 0.2 g. sample on a 347 stainless 8teel disc having an area of 12 . 5 cm2 .
Twenty-four t24) Hour Emulsion Stability at 250C of textile finishes prepared using the 2-ethylhexanol 12.6 POt8.5 EO product is shown in I Table 1.

1 1692~

Table 1 EMULSION STABILITY DATA
Surfactant: 2-Ethylhexanol 12.6POJ8.5EO
aqueou~ emul~iona Wt.fWt. 10~ _ 20~
~ Lubricant - Coconut 0~1: 80/20 Stable (b) Stable : Surfactant 70/30 S~able Stable Ratio 60/40 St~blQ Stable , .
aqueou~ emulsiona Wt./Wt. 10% 20%
Lubricant - Trimethylol- ~0/20 S~able Stable propane Trispelargonate:
Surfactant 70/30 Stable Stable ; Ratio ~0/40 Stable Stable aqueou6 emulsiona Wt./Wt. 10 _ _20~
~ubricant -:Tridecyl 80/20; Stable~ Stable Stearate:
Surfactant 70~30 Stable Unstable Ratio 60/40 Stable : Stable ~. :
: (a) Concentration of the textile fini~h (lubricant~surfactant mixture) in:water.
j~ Emulsion prepared a~ 25C. (Vol./Vol.) ~b~ Stable - emul~ion ~table for Z4 hour~ or longer.
~
. , .
.

~ ~g2~6 EXAMPL~ 2 Pre~aration of Dodecanol 5.5 PO/6.8 EO Block Polymer Dodecanol (558 gram~, 3.0 mole~) wa~ mixed with pota~sium hydroxide (4.4 grams) a6 de~cribed in Example 1. After water removal, propylene oxide (847 gram~, 1~.6 mole6) was added to ~he reactor. After the . reac~ion period wa~ complete, ethylene oxide wa~ added i to ~be 6ystem as de6cribed in Example 1 to a cloud point of 38C. Product work-up gave a colorle~ liquid having a molecular weight of 803.

Evaluation o~ the Peoduct ~ The foliowing te~t~ using the procedure : described in Example 1 were run on the product to , de~onstrate satisfactory heat-~table propertie~:
!1 5moke point 180C
Thin-film re~idue on 1.2 percen~ residue ~i stainle~s steel which wa~ a yellow varni6h which was hot 60apy water removable Other phy~ical properties were: ~
vi6co~ity ' 83 ck~ (centi~okes at 25C) il Specific Gravity 0.993 at 25C
~elting Point -5C
Cloud Point 38C

~692~6 The ~e6t~ 6hown in Table 2 were carried out to ~how emul6iQn ~tability of tex~cile finishe~ using the pr~duct of thi~ ~3xample.
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1 1~92~

Table 2 EMULSION STABILITY DATA
Surfactant: Dodecanol 5.5PO/6.8EO
agueous emul~iona W~./Wt. 10%_ 20~
Lubricant - Coconut Oil: RO/20 Un~table Unstable Surfactant 70/30 Stable(b) Stable - ~atio 60/40 Stable Stable ~ aqueou6 emulsiona Wt./Wt. 10% ZO%
: Lubricant Trimethylol- 80/20 Unstable Unstable propane Tri~pelargonate:
: Surfactant 70/30Stable Stable :
Ratio 60/40~ Stable 5table :
aqueous:emul~iona Wt./Wt, 10% 20~
Lubricant - Tride~yl 80izo Stable Stable ~, Stearate: ~
Surfactant 70~30Stable Un~table Ratio 60f40~ Stable S~able .
~ ' :
: ~ (a) Concentration of the textile ~ini~h `~ llubricant/6urfactant mixture) in water.
! :: Emul~1On prepared at 25C. (Vol./Vol.) (b) Stable - emul~ion &tabIe for 24 hours or longer.
"
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~ ~92~

CONTROL A
Preparation~ o~ Butanol 14.9 Po/8.4 Eo Block Pol~er Butanol (222 gramfi, 3.0 ~ole6) wa6 mixed with po~as~ium hydroxide ~11.4 grams) as descr~bed in Example 1. After water removal, pro~ylene oxide (2610 g~am~, 45 mole~) was adaed to the reactor. After the reaction period ~as complete, ethylene oxide was added to the ~y6tem a6 de~cribed in Example 1 to a cloud point of 23~C. Product work-up gave a colorle~ liquid having a molecular weight o~ 1229 with excellent heat-stability but poor emulfiification eropertie6.
'~
IEvalua~ion of the Product - The Pollowing te~ts u~ing the procedure - de~cribed in E~ample 1 were run on the product to demon trate the hea~ ~tability propertie~:
Smoke point 255C

Thin-film re~idue on 0.8 percent re~idue ; 6tainles6 steel which was a yellow varnish which was hot, ~oapy water removable Cloud Point 23~C
The te~t~ shown in Table 3 were carried out to show emulsion ~tability of textile fini~heæ using the butanol alkoxylate product of ~hi6 control example.

.

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.. . . . .... . . ... .. . .. . ...

~ 16~2~

Table 3 EM~JLSION 5TABILITY_DATA
5urfactant: Butanol - 14.9 PO~8.4 EO

aqueou~ emulsiona Wt./Wt. _10% 20%
Lubricant - Coconut Oil: 80/20 Un~table Un~table Surfactant 60/40 Stable(b) Unstable Ratio aqueou~ emulsiona W~./Wt. 10% 20~
Lubricant - Trimethylol- aot20 Un~table Unstable propane Tri~pelargona~e:
Surfactant 70f30 Stable S~able Ratio .~
: aqueou~ emul~iona t Wt./Wt. 10% _ 20%
i Lubrican~ - Tridecyl 80~20 Un~table Unstable Stearate: :
Surfactant 70/30 Un~table Unstable - Ratio ~::: (a) Concentration of the textile fini~h (lubricant/surfactant mixture) in water.
.` ~mul~ion pre~ared at ~5C. (Vol./Vol.) b) Stable - emulsion 6tabl~ for 24 hour~ or longer ~ 16920~
' D-13055 CONTROL_B
Preparation of Mixed C16-C18 Alcohol 4.0 PO/9.5 EO Block Polymer Epal (~rademark) 16-18 purcha~ed from ~thyl Corp., which i~ a mixture of C16-ClB alcohol ~536 grams, 2.0 ~oles) wa~ mixed with pota~ium hydroxide (S.O grams) as de~cribed in Example 1. Af~er water removal, propylene oxide (~72 gram~. 8 moles) wa6 added to the reactor. Ater the reac~ion period was complete, ethylene oxide was added to the system as described in Example 1 to give a product having a cloud point of 38C. Product work-up gave a colorles~ liquid having a molecular weight of 913 that exhibited marginal heat-~tability and poor emul~ification properties.

.
: ~ Evaluation of the Product The following ~ect~ were run on the product to demonstrate heat-stablility properties:

Smoke point 17~C

Volatility 6.7 percent per hour leaving a l~uid ; ~ ~ re~idue varni6h Thin-film re~idue 5.4 percent re~idue on stainle~ 6teel which wa~ a yellow varni~h that wa~ hot soapy water removable Other phy6ical propertie~ were:

6~20e Viscos~ ty 12û cks (centistoke~) at 25C
Vi~c06it~r . 71 ck8 at 100F
Specif ic Gra-,rity 0 . 990 ~t 25C
Melting Po;n~. 11C
Cloud Poin~ 3~C
,~ The ~ollowirlq te~ts were carried ou~ ~o !:~ evalua~.e emulsion stabiliy of textile finishe6 prepared with the alkoxyla~e product of this control example.

.

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,~, 1 ~9~0~

Table 4 sur~actant: C16 1a Alcohol 4.0 PO/9.5EO

: aqueou~ emulsiona Wt./Wt. 10% 15% 20%
. Lubr i cant Coconu~. Oil: ~0/20 Unstable Un~table Unstable Surfactant 70/30Un~table Un~table Un~table Ratio 60i40Sta~le (b~ Unstable Un~able aqueou~ emulsiona Wt./Wt.10~ 15~ _ 20 Lubr i c a nt : Trimethylol- 80/ZOUnstable Un~table Un6table : propane Tri6pelargonate:
Surfactant 70/30Stable Un~table Unstable Ratio ~0/40Unstable Un~table Unstable (a) Concentration of the textile fini~h ubricant/6urfactant mixture) in wat~r.
Emulsion prepared at 25~C. ~Vol.~Vol.) ~ (b) Stable - emuIsion stable for 24 hours or longer - :
~. ~

.
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Claims (18)

WHAT IS CLAIMED IS:

1. A spin finish for synthetic fibers consisting essentially of:
(a) about 50-90% by weight of a thermally stable lubricant selected from the group consisting of (1) esters of fatty acids having about 12 to 18 carbons and saturated aliphatic alcohols having about 8 to 18 carbons: (2) triglycerides of fatty acids having 12 to 18 carbons; (3) esters of a polyhydric alcohol and an alkanoic acid having about 8 to 12 carbons where the polyhydric alcohol has the formula (R')y - C - (CH2 OH)x wherein x is an integer having values of 3 or 4, R' is an alkyl having 1 to 3 carbons, y is an integer having values of 0 or 1 and y = 0 when x = 4; and (4) esters of dibasic fatty acids having 2 to 18 carbons and saturated aliphatic alcohols having about 4 to 18 carbons; and (b) about 10-50% by weight of a nonionic surfactant having the formula R - O (Aa Bb) H
wherein R is an alkyl having 6 to 14 carbons A is , B is CH2CH2-0-, a and b are integers having values of about 4 to 15 and 5 to 10 respectively.

2. The spin finish of claim 1 wherein R of said nonionic surfactant is an alkyl group having 8 to 12 carbon atoms.

3. The spin finish of claim 1 wherein R-0 is the residue of 2-ethylhexanol.

4. The spin finish of claim 1 wherein the lubricant is an ester of a fatty acid having 12 to 18 carbons and a saturated aliphatic alcohol having about 8 to 18 carbons.

5. The spin finish of claim 4 wherein the fatty acid is stearic acid and the alcohol is tridecyl alcohol.

6. The spin finish of claim 4 wherein the fatty acid is stearic acid and the alcohol is hexadecyl alcohol.

7. The spin finish of claim 1 wherein the lubricant is a triglyceride of fatty acids.

8. The spin finish of claim 7 wherein the triglyceride is coconut oil.

9. The spin finish of claim 1 wherein the lubricant is an ester of a polyhydric alcohol and an alkanoic acid having about 8 to 12 carbons where the polyhydric alcohol has the formula (R')y - C - (CH2 OH)x wherein x is an integer having values of 3 or 4, R' is an alkyl having 1 to 3 carbons, y is an integer having values of 0 or 1 and y = 0 when x = 4.

10. The spin finish of claim 9 wherein the polyhydric alcohol is trimethlyolpropane.

11. The spin finish of claim 1 wherein the lubricant is an ester of dibasic fatty acids having 2 to 18 carbons and saturated aliphatic alcohols having about 4 to 18 carbons.

12. The spin finish of claim 9 wherein the polyhydric alcohol is pentaerythritol.

13. Method of lubricating synthetic yarns which comprises contacting said synthetic yarns with an aqueous emulsion containing about 10 to about 20 percent based on the weight of the total solution of a spin finish consisting essentially of:

(a) About 50-90% by weight of a thermally stable lubricant selected from the group consisting of (1) esters of fatty acids having about 12 to 18 carbons and saturated aliphatic alcohols having about 8 to 18 carbons: (2) triglycerides of fatty acids having 12 to 18 carbons; (3) esters of a polyhydric alcohol and an alkanoic acid having about 8 to 12 carbons where the polyhydric alcohol has the formula (R')y - C - (CH2 OH)x wherein x is an integer having values of 3 or 4, R' is an alkyl having 1 to 3 carbons, y is an integer having values of 0 or 1 and y = 0 when x = 4; and (4) esters of dibasic fatty acids having 2 to 18 carbons and saturated aliphatic alcohols having about 4 to 18 carbons; and (b) about 10-50% by weight of a surfactant having the formula R - O (Aa Bb) H
wherein R is an alkyl having 6 to 14 carbons A is , B is CH2CH2-0-, a and b are integers having values of about 4 to 15 and 5 to 10 respectively.

14. Method claimed in claim 13 wherein the spin finish consists essentially of about 60-80% by weight of lubricant and about 20-40% by weight of surfactant.

15. Method claimed in claim 13 wherein the lubricant is coconut oil and the surfactant is a 2-ethylhexanol based propylene oxide/ethylene oxide block copolymer containing about 11 to 13 moles of propylene oxide and about 7 to 9 moles of ethylene oxide per mole of 2-ethylhexanol.

16. Method claimed in claim 13 wherein the lubricant is tridecyl stearate.

17. Method claimed in claim 13 wherein the lubricant is trimethylolpropane tripelargonate.

18. Method claimed in claim 13 wherein the lubricant is pentaerythritol tetrapelargonate.