Method of spinning a nylon yarn having improved retention of a soil repellent finish on the nylon yarn

Abstract

This invention is a method to improve retention of a finish on nylon yarn, said finish containing the reaction product of epichlorohydrin with the reaction product of pyromellitic dianhydride with a long chain fluoroalcohol, comprising polymerizing said nylon in the presence of about 0.5 to 1 mole percent of a primary-tertiary diamine of the structure ##STR1## where R.sub.1 is an alpha, omega-alkylene group of 2 to 10 carbon atoms where cycloaliphatic, R.sub.2 and R.sub.3 are alkyl radicals of 1 to 4 carbon atoms, R.sub.4 is an alkylene radical of 1 to 10 carbon atoms and R.sub.5 is R.sub.4 or arylalkyl, R.sub.6 is H or alkyl of 1 to 4 carbons, so that said nylon polymer is melt stable. Also, for batch processing, polyethyleneimines of 300 to 1200 molecular weight, methylaminobispropylamine, N-(2-aminoethyl)-1,3-propanediamine, and 3,3'-iminobispropylamine are useful.

Description

BACKGROUND OF THE INVENTION

With the advent of the soil resistant yarn finish disclosed in U.S. Pat. No. 4,192,754, hereby incorporated by reference, it was desirable to modify the yarn polymer properties to enhance the retention by yarn of the fluorocarbon component in the yarn finish. It was discovered that yarn of deep dyeable polymer which has a high number of amine ends, also has improved permanency of the soil resistant fluorocarbon finish on the yarn. However, the amine additives, used to provide the prior art deep dyeable yarn polymers, such as cyclohexylamine or hexamethylenediamine were not entirely satisfactory. Cyclohexylamine, which is conventionally used in continuous melt polymerization processes to control dyeability and degree of polymerization, for example, did not provide enough amine ends for improved retention of the fluorocarbon component of the yarn finish; and hexamethylenediamine caused runaway polymerization rates, i.e., a polymer melt that was not stable during continuous polymerization and/or spinning of fiber.

SUMMARY OF THE INVENTION

It has been discovered that a melt stable polymer and a polymer that provides deep dyeable yarn with improved retention of the fluorocarbon component of the soil resistant finish for the yarn can be made using the additives of this invention as terminators for the polymer ends. The preferred amount of titratable amine ends is over 80, preferably over 90, gram equivalents per 10.sup.6 grams of polymer. Also, for melt stability in a continuous melt polymerization process, the product of reactive ends, obtained by multiplying equivalents of reactive amine ends by equivalents of carboxyl ends, must be low, such as preferably about 300 to 1100. This is achieved by producing a polymer with low carboxyl end groups, i.e., about 10 to 25 gram equivalents per 10.sup.6 grams of polymer. All this is achieved by use of the additives of this invention which provide the necessary additional amine sites for fluorocarbon retention yet are nonreactive. This invention is a method to improve retention of a finish on a nylon yarn, said finish containing a reaction product of the group consisting of propylene oxide, epibromohydrin and epichlorohydrin with the reaction product of pyromellitic dianhydride with a long chain fluoroalcohol, comprising polymerizing said nylon in the presence of between about 0.03 to 1 mole percent of a primary-tertiary diamine or a primary-tertiary triamine of the structure ##STR2## wherein R.sub.1 is an alkylene group of 2 to 10 carbon atoms or a cycloaliphatic, R.sub.2 and R.sub.3 are alkyl radicals of 1 to 4 carbon atoms, R.sub.4 is an alkylene group of 1 to 10 carbon atoms and R.sub.5 is R.sub.4 or an aralkyl, R.sub.6 is H or alkyl of 1 to 4 carbon atoms, so that said nylon polymer is melt stable.

When the polymerization is done in a batch process, the above compounds can be used, also the following compounds can be used:

polyethyleneimine of 300 to 1200 molecular weight, 3,3'-diamino-N-methyldipropylamine, N-(2-aminoethyl)-1,3-propanediamine, 3,3'-iminobispropylamine, N,N-bisaminopropylpiperazine, and N-(2-aminoethyl)piperazine. The preferred polyethyleneimine has the structure ##STR3## where x is 1 to 40 and R is hydrogen, lower alkyl or ##STR4## where y is 1 to 40 but x+y must be less than 43. Even more preferred is the polyethyleneimine which has a lower alkyl of 1 to 4 carbon atoms. The above compounds are useful both for continuous, coupled nylon polymerization exemplified in U.S. Pat. No. 4,310,659, hereby incorporated by reference, and batch polymerization. By batch polymerization is meant both conventional one-kettle batch polymerization and the use of a series of kettles for continuous batch polymerization exemplified in U.S. Pat. No. 3,294,756, hereby incorporated by reference.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the percent retention of fluorocarbon on fiber at 2 pH levels and 4 total amine levels for Beck-dyed fiber for the process of this invention and the control prior art method. See Table IV.

FIG. 2 is a reworking of the data in FIG. 1 to "damp-out" the effect of dye bath pH as explained in the text regarding Table IV.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Example 1

(A) A polymer was prepared by adding 10.3 grams of N-(3-aminopropyl)morpholine to a mixture of 1520 grams of caprolactam and 80 grams of omega-aminocaproic acid. The mixture was heated to 255.degree. C. over a one-hour period, under a nitrogen atmosphere and then held at 255.degree. C. for 6.5 hours. The polymer was washed 5 times with an equal weight of deionized water and then dried at 100.degree. C. under vacuum for 16 hours. A sample of this polymer was analyzed. The formic acid viscosity was 47, with 10 equivalents of carboxyl and 101 titratable equivalents of amine per 10.sup.6 grams of polymer.

(B) This polymer was spun at 260.degree. C. into yarn of 30 round filaments having a total denier of 250. The yarn was coated with a finish having an antisoiling fluorocarbon as that disclosed in U.S. Pat. No. 4,192,754, Example 1. The yarn was knitted into sleeves.

Two samples of the knitted sleeves were taken. One sample was steam autoclaved, that is, heat set at 270.degree. F., while the other was not.

Autoclaving consisted of putting the knitted sleeves into an autoclave, evacuating the chamber to 27 inches of vacuum and introducing steam to heat the chamber to 230.degree. F. The chamber is held at 230.degree. F. for five minutes, and the pressure released. The chamber is then repressurized with steam to heat to 230.degree. F. The pressure is held for five minutes and released. Then steam is introduced and the temperature is allowed to rise to 270.degree. F. The pressure is released and then steam is put in again until the temperature is 270.degree. F. It is held for five minutes and again the pressure released. Then it is repressurized to give a temperature of 270.degree. F. for eight minutes. The pressure is then released and the yarns removed from the autoclave.

The sleeves, both the nonheat set and heat set, were submitted for launderometer washing. After one hour of washing and again after five hours of washing, the sleeves were tested for oil drop repellency by A.A.T.C.C. Test Method 118-1975. A rating of 5 is best, 0 worst. Both the nonheat and the heat set sleeves were also tested for retention of the fluorine antisoil agent by use of the Schoniger combustion technique. The fluorides are quantitatively determined using the fluoride specific ion electrode. (See Light, T. S. and Mannion, R. F., "Microdetermination of Fluorine in Organic Compounds by Potentiometer Titration Using a Fluoride Electrode", Analytical Chemistry, Vol. 41, 1969, page 107.) This yarn retained 87% of the fluorocarbon which was initially on the yarn. A conventional continuous melt-process control yarn, shown below as Example 2, which had 53 gram-equivalents of amine and 25 gram-equivalents of carboxyl per million grams of polymer retained only 57% of the fluorocarbon.

The one-hour treatment in the launderometer simulates a conventional beck dyeing cycle. The five-hour treatment simulates dyeing and severe scouring of a fiber in use. The data on these yarns are shown in Table I below.

TABLE I______________________________________ Carboxyls TitratableEx- Per 10.sup.6 Amines Peram- Polymer, Grams 10.sup.6 Gramsple Additives, Grams FAV.sup.(a) Polymer Polymer______________________________________ 1 APM.sup.1 10.3 47 10 101 2* CHA.sup.2 6.4 51 25 53 3 DEAP.sup.3 7.4 46 19 92 4 GAMP.sup.4 3.9 48 10 102 5 GAMP 3.9 53 17 86 6 GAMP 5.6 68 20 72 7 AEP.sup.5 8.2 41 11 132 8 BAPP.sup.6 11.5 44 11 131 9 BAPP 19.3 51 23 123 TPA.sup.7 16.010 BAPP 2.86 58 26 79 HMDA.sup.8 3.74 TPA 2.411 BAPP 2.86 59 21 66 CHA 4.96 TPA 2.412 BAPP 8.6 47 29 86 CHA 4.96 TPA 7.1313** HMDA 2.5 63 27 5614** HMDA 3.7 49 30 7215** HMDA 5.8 41 17 7216** HMDA 7.1 39 13 9217 None, Control 57 48 4718 PEI.sup.9 11.9 45 15 18219 PEI 11.9 58 11 17120 TETA.sup.10 5.8 58 12 118______________________________________ Oil Drop Rating AATCC Method 118-1975 After 1 and 5-Hour Product LaunderometerTheoretical of Nonheat Set Heat Set Reactive Reactive 1 5 1 5Example Amine Ends Ends Hour Hours Hour Hours______________________________________ 1 53 530 4 2 4 1 2* 53 1425 5 4 4 3 3 54 1026 2 2 2 0 4 9 90 4 2 4 2 5 15 255 4 2 2 3 6 20 400 3 1 3 0 7 69 759 4 2 4 1 8 91 1001 4 2 3 1 9 42 966 4 3 4 210 59 1534 6 3 4 311 46 966 5 2 3 312 57 1653 5 4 4 313** 56 1512 4 3 3 014** 72 2160 5 2 4 315** 72 1224 5 3 4 316** 92 1196 4 3 5 117 47 2256 4 3 4 118 130 1950 5 3 5 319 120 1320 5 1-2 5 320 118 1416 3-4 1-2 5 3______________________________________Fluorine Level, ppmBefore AfterExample 5-Hour Launderometer % Fluorine Retention______________________________________ 1 368 320 87 2* 509 290 57 3 238 238 100 4 428 374 88 5 420 412 98 6 294 266 89 7 368 368 100 8 287 287 100 9 387 279 7210 381 343 9011 317 295 9312 434 295 6813** 400 268 6714** 543 337 6215** 323 301 9316** 357 357 10017 505 273 5418 504 302 6019 544 512 9420 512 428 84______________________________________ NOTES TO TABLE I .sup.1 N--(3aminopropyl)morpholine .sup.2 Cyclohexylamine .sup.3 N,N--diethyl1,3-propanediamine .sup.4 N--(3aminopropyl)-N'--methylpiperazine .sup.5 N--(2aminoethyl)piperazine .sup.6 N,N'--bis(3aminopropyl)piperazine .sup.7 Terephthalic Acid .sup.8 1,6Hexanediamine .sup.9 Polyethyleneimine (Corcat P12, Cordova Chemical Co.) .sup.10 Triethylenetetramine *Control and prior art **Prior art .sup.(a) Formic acid viscosity

Examples 3 Through 20

The polymer preparation, and yarn and sleeve preparation of Example 1 were repeated with the compounds listed, in the amounts shown, under the conditions shown, and providing the results shown in Table I. The yarns of Examples 1 through 17 had 30 round filaments with a total denier of 250. Examples 18, 19, and 20 had 70 Y-shaped filaments with a total denier of 1150.

Examples 1 and 3 through 6 are polymers which could be used in a continuous polymerization process or in a batch process. Examples 7 through 20 can be also used in a batch process. Examples 13 through 16 are prior art.

In Examples 9 through 12, TPA (terephthalic acid) is added so that additional amounts of N,N'-bis(3-aminopropyl)piperazine can be added without decreasing the degree of polymerization.

Example 17 is a control yarn to which the other batch process polymers should be compared.

Example 21

A nylon 6,6 polymer is prepared by dissolving 5840 grams of purified salt made from hexamethylenediamine and adipic acid (22-26 moles) in 5840 grams of water. As a molecular weight regulator, 17.5 grams of cyclohexylamine is added. Sodium hypophosphate, 5 grams, is added as a stabilizer. The mixture is heated to 135.degree. C. in an agitated pressure vessel, holding the pressure to a maximum of 15 psig. After the internal temperature reaches 135.degree. F. the reactor is heated rapidly to an internal temperature of 250.degree. C. The vessel is vented to hold the pressure to a maximum of 250 psig.

After the temperature reaches 250.degree. C. and 250 psi, the pressure is bled off slowly while raising the temperature to 270.degree. C. over a period of 90 minutes. The rate of temperature increase is constant and the rate of pressure release is such that equal fractions of the absolute pressure are released in equal intervals of time.

After the reactor temperature has reached 270.degree. C. and the pressure is 0 psig, nitrogen is swept across the surface of the molten polymer for one hour. Then the agitator is stopped and after 15 minutes the polymer is extruded from the bottom of the reactor and pelletized. The formic acid viscosity is 55 with 20 equivalents of carboxyl ends and 55 equivalents of amine ends per 10.sup.6 grams of polymer.

This polymer is spun at 285.degree. C. into yarn of 30 round filaments having a total denier of 250. The yarn is coated with the finish described in Example 1, and knitted into a sleeve. After five hours of launderometer washing the yarn retains 60% of the fluorine antisoil agent which was initially on the yarn.

Example 22

A nylon 6,6 polymer is prepared in the same manner as that described in Example 21 except that, in addition, 74 grams of the salt of terephthalic acid and N,N'-bis(3-aminopropyl)piperazine is added to the pressure vessel with the salt solution. After polymerization and pellitizing the polymer, FAV is 55 with 20 equivalents of carboxyl ends and 95 equivalents of amines per 10.sup.6 grams of polymer.

The polymer is spun and finished as in Example 23, and knitted into a sleeve. After the sleeve is given five hours of launderometer washing, the yarn retains 85% of the fluorine antisoil agent which is coated onto the yarn.

Example 23

A nylon 6,6 polymer is made as described in Example 21, but with the addition of 25.4 grams of N-(3-aminopropyl)morpholine instead of 17.5 grams of cyclohexylamine. The resulting polymer has a formic acid viscosity of 55 with 20 carboxyls and 90 amines per 10.sup.6 grams of polymer.

The polymer is spun and finished as in Example 21, and knitted into a sleeve. After the sleeve is given five hours of launderometer washing the yarn retains 90% of the fluorine antisoil agent which is coated onto the yarn.

Continuous Polymerization Examples

A comparison of the polymer of the method of this invention with a nylon 6 terminated with an amine containing no tertiary amino groups, cyclohexylamine, was made with polymers prepared with the process and apparatus similar to that shown in U.S. Pat. No. 4,310,659, hereby incorporated by reference, in toto. The following Table II shows the polymers used in the trials.

TABLE 11______________________________________Polymer Primary Tertiary TotalDesignation Amines* Amines* Amines* Terminator______________________________________A 54 0 54 CHAB 27 0 27 CHA/HACC 54 44 98 APMD 27 34 61 APM/HAC______________________________________ *In mol equivalents per 10.sup.6 grams of Terminators "HAC" -- Acetic Acid "CHA" -- Cyclohexylamine ##STR5## "APM" -- N(3Aminopropyl)morpholine- ##STR6##

The resulting polymers were spun with a finish similar to that of Example of U.S. Pat. No. 4,192,754 under conventional conditions into fibers and conventionally processed into staple yarn, dyed and tested for fading on knitted sleeves with the following results. A surprising improvement of over 0.5 on a Gray scale shows in ozone fastness in Table III.

TABLE III______________________________________Shade DAL NO.* B D A C______________________________________XENON LIGHT FASTNESS100 SFU (GRAY SCALE), AATCC-16EBurlington Gray 2008 +4 3-4 3 3Tectilon Olive 3015 3-4 3-4 3 3Lightfastness 5010 4 4 4 4Beige #1Burlington Rose 7001 +4 3 4 4Toasted Chestnut 9116 5 5 5 5Renoir Rose 9153 4 4 +3-4 2-3Argent Grey 9529 2 +2-3 2 -2Average 3.79 3.64 3.5 3.36Gray Scale(n = 7)Delta -0.15 -0.14OZONE FASTNESSAATCC-129, 3 CYCLES (GRAY SCALE)Burlington Gray 2008 1-2 1-2 3 4Tectilon Olive 3015 2-3 5 4-5 4-5Lightfastness Beige 5010 1-2 3 2-3 3-4Burlington Rose 7001 2 2 3 4Toasted Chestnut 9116 5 5 3-4 4-5Renoir Rose 9153 4 4 3-4 2-3Argent Grey 9529 2 2-3 2 2Average 2.21 2.93 3.57 4.07Gray Scale(n = 7)Delta -- +0.72 +0.5______________________________________ *The Dyeing Application Laboratory (DAL) number is explained following this table. ______________________________________DYE APPLICATION LABORATORY(DAL) FORMULATIONS % By Weight on Fabric______________________________________NUMBER 2008DyesTectilon Red 2B (Acid Red 361) 0.05Tectilon Orange 3G (Acid Orange 156) 0.04Telon Blue BRL (Acid Blue 324) 0.05ConditionsLiquid to Fabric Ratio 30/1Temperature, .degree.F. - BoilTime, Minutes - 45pH by MSP/TSP (1) - 7.0Chemicals Added: Dowfax 2A1 (2) - 1.5%NUMBER 3015DyesTectilon Blue 4R (Acid Blue 277) 0.018Tectilon Red 2B (Acid Red 361) 0.048Tectilon Yellow 4R (Acid Yellow 219) 0.030ConditionsLiquid to Fabric Ratio 30/1Temperature, .degree.F. - 205Time, Minutes - 45pH by MSP/TSP (1) - 7.0Chemicals Added: Triton X-100 - 0.5% (3)NUMBER 5010DyesTectilon Yellow 4R (Acid Yellow 219) 0.092Tectilon Red 2B (Acid Red 361) 0.061Tectilon Blue 4R (Acid Blue 277) 0.057ConditionsRatio of Liquid to Fabric - 30/1Temperature, .degree.F. - 205Time, Minutes - 60pH by MSP/TSP (1) - 7.0Chemicals Added: Dowfax 2A1 - 1.5%NUMBER 7001DyesTectilon Red 2B (Acid Red 361) 0.17Tectilon Orange 3G (Acid Orange 156) 0.079Telon Blue BRL 200% (Acid Blue 324) 0.032ConditionsRatio of Liquid to Fabric - 30/1Temperature - BoilTime, Minutes - 45pH by MSP/TSP (1) - 7.0Dowfax 2A1 - 1.5%NUMBER 9116DyesTelon Blue BRL 200% (Acid Blue 324) 0.0992Tectilon Red 2B (Acid Blue 361) 0.2529Tectilon Yellow 4R (Acid Yellow 219) 0.2454ConditionsRatio of Liquid to Fabric - 30/1Temperature .degree.F. - 205Time, Minutes - 45pH by MSP/TSP (1) - 7.0Chemicals Added:Dowfax 2A1 - 1.0%Triton X-100 - 0.5%NUMBER 9153DyesTelon Blue BRL 200% (Acid Blue 324) 0.0110Tectilon Red 2B (Acid Blue 361) 0.0937Tectilon Orange 3G (Acid Orange 156) 0.0359ConditionsLiquid to Fabric Ratio - 30/1Temperature, .degree.F. - 205Time, Minutes - 45pH by MSP/TSP (1) - 7.0Chemicals Added:Dowfax 2A1 - 1.0%Triton X-100 - 0.5%NUMBER 9529DyesTelon Blue BRL 200% (Acid Blue 324) 0.0135Tectilon Red 2B (Acid Red 361) 0.0121Tectilon Orange 3G (Acid Orange 156) 0.0115ConditionsLiquid to Fabric Ratio - 30/1Temperature, .degree.F. - 205Time, Minutes - 45pH by MSP/TSP (1) - 7.0Chemicals Added:Dowfax 2A1 - 1.0%Triton X-100 - 0.5%______________________________________ (1) MSP is monosodium phosphate TSP is trisodium phosphate (2) Dowfax 2A1 is a sodium dodecyl diphenyloxide disulfonate anionic liquid (3) Triton X100 is alkanyl polyether alcohol, a nonionic surfactant, from Rohm & Haas

Most importantly, a surprising improvement in fluorine retention of 4% to over 10% was found when measuring amounts of fluorocarbon from the spin finish remained on the fiber, with no loss of floor wear performance, including the improved staining and soiling of the carpet due to fluorocarbon on the fiber. The results in FIG. 1 are averages of tests of fibers of the polymers shown, Beck dyed yellow at the pH of the dye bath shown. The fiber was crimp set conventionally with Suessen equipment. Overall percent retention is affected by pH as can be seen in FIG. 1. The raw data used to calculate the points of FIG. 1 are shown in the following Table IV.

TABLE IV______________________________________Yarn 1 is bright, 2.7 modification ratio "Y" crosssection, deep dyeable, 15 denier per filament staple yarn,crimp stabilized. The fluorocarbon level was 0.14 weightpercent.Yarn 2 is bright, 3.0 modification ratio, "Y"cross section, deep dyeable, 17 denier per filament stapleyarn, crimp stabilized, with 0.14 weight percentfluorocarbon. -Yarn 3 is bright, 2.7 modification ratio "Y" crosssection, medium dyeable 15 denier per filament stapleyarn, crimp stabilized, with 0.14 weight percentfluorocarbon. -Polymer A is terminated with 44 equivalentscyclohexylamine per 10.sup.6 grams polymer.Polymer B is terminated with 34 equivalentscyclohexylamine per 10.sup.6 grams polymer and with 27equivalents acetic acid per 10.sup.6 grams polymer.Polymer C is terminated with 44 equivalentsaminopropyl morpholine per 10.sup.6 grams polymer.Polymer D is terminated with 34 equivalentsaminopropyl morpholine per 10.sup.6 grams polymer and with 27equivalents acetic acid per 10.sup.6 grams polymer.Polymers A and B are comparative, prior art polymers.Finally, to "damp-out" the effect of dye bath pH,FIG. 2 was prepared from data in Table IV "Averaging",showing a 4% to 10% improvement in fluorine retention overthe best prior art polymer. Using percent change inretention rather than the actual percent retentioneliminates differences due to pH.______________________________________ ppm of Fluorine______________________________________RUN 1 - YARN 1 Polymer A Polymer C______________________________________Suessen Set 506 572 559 319Beck Dyed (1)1 Hr. 307 391 320 2383 Hrs. 225 293 251 2035 Hrs. 176 198 191 1978 Hrs. 156 160 175 162______________________________________YARN 2 Polymer A Polymer C______________________________________Suessen Set 585 560 561 514Beck Dyed (1)1 Hr. 242 244 293 2853 Hrs. 197 188 223 2125 Hrs. 170 160 183 1868 Hrs. 159 150 231 150______________________________________YARN 3 Polymer B Polymer D______________________________________Suessen Set 604 568 448Beck Dyed (1)1 Hr. 248 302 2363 Hrs. 186 242 1955 Hrs. 173 190 1388 Hrs. 110 169 126______________________________________ (1) Beck dyed at pH 8.5 ______________________________________AVERAGING OF DATA ABOVERUN NO. 1______________________________________ % ppm Fluorine Average Retention______________________________________YARNS 1 AND 2 - POLYMER ASuessen Set 506 585 560 550 100Beck Dyed (1)1 Hour 307 242 244 264 48.03 Hours 225 197 188 203 36.95 Hours 176 170 160 169 30.78 Hours 156 159 150 155 28.2YARNS 1 AND 2 - POLYMER CSuessen Set 572 559 561 514 552 100Beck Dyed (1)1 Hour 391 320 293 285 322 58.33 Hours 293 251 223 212 245 44.45 Hours 198 191 183 186 190 34.48 Hours 160 175 231 150 179 32.4YARN 3 - POLYMER DSuessen Set 568 448 508 100Beck Dyed (1)1 Hour 302 236 269 53.03 Hours 242 195 219 43.15 Hours 190 138 164 32.38 Hours 169 126 148 29.1YARN 3 - POLYMER B 604 100 248 41.1 186 30.8 173 28.6 110 18.2______________________________________RUN 2 - YARN 1 Polymer A Polymer C ppm % ppm % Fluorine Rentention Fluorine Retention______________________________________Nonheat Set 555 100 551 100Suessen Set 549 98.9 475 86.2Beck Dyed (2)1 Hour 510 91.9 488 88.62 Hours 422 76.0 439 79.73 Hours 407 73.3 459 83.34 Hours 332 59.8 403 73.15 Hours 326 58.7 454 82.46 Hours 340 61.3 383 69.57 Hours 325 58.6 403 73.1______________________________________ (1) pH 8.5 (2) pH 6.5

Example 24 (Comparative)

A polymer was prepared by the process exemplified in U.S. Pat. No. 3,294,756 using no terminator to form a light stable bright polymer, spun under conventional spinning processing to form a commercial yarn and tested for the properties in Table I with the following results:

FAV--56 Carboxyls per 10.sup.6 grams per polymer--48 Theoretical Reactive Amine Ends--48 Product of Reactive Ends--2400 Oil Drop Rating-- Nonheat set--2 Heat set--0 Fluorine level, ppm--Before--388 After 5 hours launderometer--299 % Fluorine retention--77

Claims

1. A method to improve retention of a soil repellent finish on nylon yarn, said finish containing the reaction product of the group consisting of propylene oxide, epibromohydrin and epichlorohydrin with the reaction product of pyromellitic dianhydride with a long chain fluoroalcohol, comprising continuously polymerizing precursors of said nylon in contact with between about 0.03 and 1 mol percent of a primary-tertiary diamine or a primary-ditertiary triamine of the structure ##STR7## where R.sub.1 is an alpha, omega alkylene or group of 2 to 10 carbon atoms or a cyclo aliphatic,

R.sub.2 and R.sub.3 are alkyl radicals of 1 to 4 carbon atoms,

R.sub.4 is an alkylene group of 1 to 10 carbon atoms,

R.sub.5 is R.sub.4 or aralkyl, and

R.sub.6 is H or alkyl of 1 to 4 carbons so that said nylon is melt stable, continuously spinning said nylon into a yarn and coating said yarn with said finish, thereby improving retention of said finish on said yarn on exposure to heated water.

2. The method of claim 1 wherein the polyethyleneimine has the structure ##STR8## where x is 1 to 40 and R is hydrogen, lower alkyl or ##STR9## where y is 1 to 40, but x+y must be less than 43.

3. The method of claim 2 wherein the lower alkyl has 1 to 4 carbon atoms.

4. A method to improve retention of a soil repellent finish on nylon yarn, said finish containing the reaction product of the group consisting of propylene oxide, epibromohydrin and epichlorohydrin with the reaction product of pyromellitic dianhydride with a long chain fluoroalcohol, comprising polymerizing precursors of said nylon in a batch process in contact with between about 0.03 and 1 mol percent of a compound selected from the group consisting of polyethyleneimine of 300 to 1,200 molecular weight, 3,3'-diamino-N-methyldipropylamine, N-(2-aminoethyl)-1,3-propanediamine, 3,3'-iminobispropylamine, and a primary-tertiary diamine or a primary-ditertiary triamine of the structure ##STR10## where R.sub.1 is an alpha, omega alkylene or group of 2 to 10 carbon atoms or a cyclo aliphatic,

R.sub.2 and R.sub.3 are alkyl radicals of 1 to 4 carbon atoms,

R.sub.4 is an alkylene group of 1 to 10 carbon atoms,

R.sub.5 is R.sub.4 or aralkyl, and

R.sub.6 is H or alkyl of 1 to 4 carbons so that said nylon is melt stable, spinning said nylon into a yarn and coating said yarn with said finish, thereby improving retention of said finish on said yarn on exposure to heated water.

5. The method of claim 1 wherein the yarn is dyed and dye retention is improved on exposure to ozone.