US3542745A - Terpolyamides useful in preparing textile fibers consisting essentially of nylon 66,nylon 6,and nylon 2-6ia - Google Patents

Description

United States Patent 3,542,745 TERPOLYAMIDES USEFUL 1N PREPARING TEX- TILE FIBERS CONSISTING ESSENTIALLY OF NYLON 66, NYLON 6, AND NYLON 2-6IA Rupert J. Snooks, Jr., Gulf Breeze, Fla., assignor to Monsanto Company, St. Louis, Mo., a corporation of Delaware No Drawing. Filed Oct. 29, 1968, Ser. No. 771,617 Int. Cl. 008g 20/12, 20/20 US. Cl. 260--78 9 Claims ABSTRACT OF THE DISCLOSURE Textile fibers spun and drawn from a synthetic linear polyamide having a polymer chain consisting of at least 93 weight percent 0 0 -NnoH2)u-Nn hcn, b units, from 0.25 to 3 weight percent 0 NH(CH2)5&-

units and from 0.5 to 4 weight percent o 0 NH(CH2)NH( J J units in which n is 2 to 6 are of improved quality and dyeability.

. BACKGROUND OF THE INVENTION -Nylon 66 (po yhexamethylene adipamide) is well known for -its superior textile properties. However, it does have certain disadvantages when used in providing textile yarns. One disadvantage is that when nylon 66 is processed into drawn yarn, the yarn tends to contain one or more short segments along its length which have a denier greater than that intended. These segments are flaws in the yarn which result from defects in the polymer or from imperfections in the spinning operation. In knitting operations as the yarn passes through eyes of knitting machines such segments bind in the eyes causing the yarn to break. The term internal quality has been coined to reflect the number of these segments which exist along the length of the yarn and is deter mined by passing a sample of the yarn through a passage defined by two pairs of parallel blades, one pair being positioned parallel above the other pair and at a 90 angle thereto, i.e., The spacing between the parallel blades of each pair is set to permit yarn of a selected denier to pass through the passage defined by the blades without obstruction. However, if the yarn contains segments of larger denier, the blades cut the yarn. The number of cuts (breaks) in the yarn which occur in passing the yarn through the passage divided by the number of pounds of yarn involved is expressed as the internal quality (breaks per pound) of the yarn. In providing yarn for use in knitting operations, the internal quality of theyam is of major concern.

' Another disadvantage in processing nylon 66 into textile yarns is that fibers or fabrics prepared therefrom do not dye rapidly or uniformly.

An object of the present invention therefore is to provide a nylon yarn having physical properties comparable to nylon 66 as well as having improved internal quality, a high dye absorption rate and improved uniformity of dyeing.

3,542,745 Patented Nov. 24, 1970 SUMMARY OF THE INVENTION The above and other objects are accomplished by providing a textile filament spun and drawn from a synthetic linear terpolyamide having a polymer chain consisting of from about 93 to 99.25 weight percent of the repeating unit -NH(oH2)flNHi 1 oH2)4 (66 units) from 0.25 to 3 weight percent of the repeating unit 0 NH(CHz) J (6 units) and from 0.5 to 4 weight percent of the repeating unit in which n is 2 to 6, wherein said 66 units, 6 units and nIA units are randomly distributed throughout said polymer chain.

The terpolyarnides may be prepared by polymerizing a mixture consisting of appropriate amounts of the terpolyamide-forming components in the manner well known in the art and commonly employed in the manufacture of nylon 66. Thus, the terpolyarnides may be prepared according to a modified nylon 66 process wherein appropriate amounts of e-caprolactam and the selected diamine salt of isophthalic acid are added either separately or in combination to the nylon 66 salt at any point in the process prior to polymerization.

The amount of e-caprolactam or e-amino-caproic acid used in forming the terpolyarnides preferably ranges from about 0.25 to 3 mole percent, based on the total weight of the terpolyamide-forming components. Although slightly greater amounts could possibly be used without altering the character of the resulting terpolyamide, the improvement, if any, achieved thereby would be outweighed by cost considerations. The amount of diamine-isophthalic acid salt used in preparing the terpolyamides preferably ranges from about 0.5 to 4 mole percent. If greoater amounts are employed, the shrinkage and other physical properties of the terpolyarnides are noticeably changed.

The invention is further illustrated by the following examples.

PREFERRED EMBODIMENTS OF THE INVENTION Example 1 .Dry e-caprolactam monomer was added to 40% aqueous solution'of hexarnethylene diammonium isophthalate (nylon 6IA salt) and this combination was added to normal 50% aqueous solution of nylon 66 salt prior to beginning evaporation. The quantities of caprolactam and nylon 6IA salt were selected to produce a 250-pound batch of terpolyamide containing 4 weight percent 61A units, 0.5 weight percent 6 units and 95.5 weight percent 66 units. The salt mixture was charged to a stainless steel evaporator and heated to 137 C. while maintaining a pressure within the evaporator of 13 p.s.i.g. to obtain a solution. The solution is then transferred to a stainless steel autoclave wherein the temperature is gradually increased to 270 C. to effect polymerization. When the batch temperature reached 200 C., sufficient 30% aqueous Ti0 was added to provide 0.3 weight percent in the terpolymer. The molten terpolymer having a melt viscosity of 30 was extruded onto a casting wheel, solidified and cut into chips. The chips were subsequently charged to a spinning grid, melted at a temperature of 293 C., and pumped at a pressure of 4000 p.s.i.g. through a sand pack filter and 13-h0le spinneret to form a bundle of filaments which are quenched by a crosscurrent flow of air. After cooling, the filament bundle placed in a rotating cell and light is impinged on the yarn and the reflected light was measured and a value determined. The lower the value, the greater the dye depth and the diffusivity of the fiber. The standard deviation of the samples were determined statistically using 26 randomly was passed downward over a finish roll for application Selected bobbins from the P 20 P P Chwmacyl of finish and wound onto a bobbin. The spun yarn com- Black W (Acid Black is formed y Complexing two posed of 13 filaments and having a nominal total denier atoms of Chromium with three moles of! of 123 was drawtwisted using a conventional Whitin OH HO RG-4 drawtwister at a draw ratio of 3.51 to 1 to yield I 40 denier yarn having /2 Z twist. NaOaS -N=NC Nylon 66 yarns were also prepared for purposes of comparison according to the procedure just described with the exception that the caprolactam and nylon 61A salt I were omitted. Properties of the yarns were determined and NO: are given in Table I. The internal quality of the yarns It will be observed from the data obtained in Examples was determined by the procedure described above. 2 and 3 that the Chromacyl Black dye value determined TABLE I Drawtwist performance, Internal Draw Elon- Breaking breaks and quality, ratio Denier gatlon strength Tension wraps/lb. bks./lb.

Nylon 66 3. 23 39. 7 31. 5 188 4. 74 0. 107 1. 654 Terpolyamidea. 51 40. 1 29. a 191 4. 76 0. 075 0. 417

The results in Table I show that the drawtwist performfor each composition correlates closely with the percent ance and internal quality of the terpolyamide yarns, when diameter penetration value and the time to half dye value compared to nylon 66 yanrs, are signficantly superior. determined therefor. Thus, for example, a composition In the following examples the dye rate and dye pene- 0 having a lesser time to half dye value and a greater pertration of the yarns were also determined. cent diameter pentration value, will also have a lesser The dye rate of the yarns was measured by immersing Chromacyl Black dye depth value. However, the detera skein of yarn weighing 6 grams into a dye bath conmination of the time to half dye values and the percent taining 0.2 gram Ortolan Bordeaux RR (Acid Red 296) diameter pentration values are tedious analytical proceand 750 ml. of pure water. The dyebath was maintained dures, whereas the determination of Chromacyl Black dye at a temperature of 89:L-1 C. Acid Red 296 is a chrodepth values is a relatively simple procedure. mium complex derived from Example 2 9 A series of yarns, each having a different composition, C were prepared according to the procedure of Example 1, with the exception that a 26-hole spinneret was employed slozNflo rather than a 13-hole spinneret and the yarn was drawn to a denier of 30. The composition of each yarn in the series and is substantially equivalent to Perlon Fast Red 3B5 15 glven m Table The dye Penal-anon, dye rate and which is no longer produced. A Beckman DK2A record- Black depth values of e yam were ing spectophotometer measures and records the concen determined follow1ng the procedures described above and tration of dye in the bath as a function of time. From the drawtwlst Performance of each yam was observedthese data the time required for the yarn sample to reach The results are glven m Table half of its saturation value was calculated.

The dye penetration of the yarns was measured by immersing a skein of yarn weighing 5 grams into a dyebath containing 0.025 gram of Color Index Number Acid TABLE H Blue 113 (Pontacyl Fast Blue 5 R) and 1000 ml. of pure Y W D W1 t cgft'mkagter rerce nt TI water. The dy ebath was maintained at a temperature beg'g gt gf y 333335, g ,gg figgi to :3 tween 80 '90 C. Pontacyl Fast Blue 5R has the structure 66 6m 6 hm 5 0 w gt n 11 1 1; 1 1 7 -8- 21:22: as; ea 0. 028 118-30. 1 72. 3 1. 5 o. 084 227-33. 7 53. 3

After 30 minutes the yarn sample was dried, cross-sectioned and the percent radial penetration measured microscopically.

According to an alternative procedure for measuring the dye penetration and dye rate of yarns a skein of yarn, after scouring to remove the spin finish, was dyed in Chromocyl Black w solution containing 0.25 weight percent dye, 0.5 weight percent ammonia and 40 ml. of pure water per gram of yarn. When the yarn sample was immersed in the dyebath, the dyebath temperature was 70 F. The bath was increased to 190 F. in 10 minutes and then to 212 F. in 10' additional minutes. Dyeing was continued for minutes at 212 F. The yarn sample was then rinsed, dried and the reflectance thereof measured using a refiextometer as follows: the yarn sample was Example 3 A series of yarns, each having a dilferent composition, were prepared according to the procedure of Example 1 and tested in the same manner as described in Example 2. The results of these tests are given in Table III.

draw ratio required to produce a given yarn elongation (denier) is higher than that required for the other yarns.

What is claimed is: 1. A linear synthetic terpolyamide having a polymer chain consisting essentially of 93 to 99.25 weight percent or randomly repeating units of the structure 0.25 to 3 weight percent of randomly repeating units of the structure and 0.50 to 4 weight percent of randomly repeating units of the structure TABLE III Yarn composition, Drawtwist Colormaster weight percent perform- Internal dye depth, Diameter Time to ance, quality Draw Chromaeyl penetration, half dye, 66 61A 6 41A 21A breaks/lb. breaks/l ratio black percent seconds Unrunnable. Estimated.

The results in Table III further demonstrate that yarn 0 0 prepared from the terpolyamides of the present invention E ,E have excellentdrawtwlst performance, mternal quality and units, 4 weight percent dye characterlstlcs. Surpnsmgly, yarns composed of 6 6 6-4IA and -6662IA dyed darker with the Chromoacyl 20 Black dye than the yarns composed of 66, 66-61A or 66- NH(CHz) i3 6-6IA even though the draw ratio ofthe yarns was conunits and 2 Weight percent slderably higher. Moreover, an increase in spinning production is realized in spinning yarns composed of 66-6- E; E 41A and 66-6-2TA Since at constant spinning speeds the 25 NH(CH2)|1NH units in which n is an integer from 2 to 6.

7. The nylon filament of claim 6, wherein n is 6.

8. The nylon filament of claim 7, wherein n is 4.

9. The nylon filament of claim 7, wherein n is 2.

References Cited UNITED STATES PATENTS 2,071,253 2/1937 Carothers 260-78 2,252,555 8/ 1941 Carothers 260-78 2,252,557 8/1941 Czerwin 26078 3,310,534 3/1967 Brignac 26078 3,322,731 5/1967 Cook et al. 260-78 3,383,369 5/1968 Ridgway 260-78 3,399,108 8/1968 Olson 161173 3,454,536 7/1969 Schade et al. 260-78 FOREIGN PATENTS 1,025,098 4/1966 Great Britain.

1,114,541 5 1968 Great Britain.

WILLIAM H. SHORT, Primary Examiner H. SCHAIN, Assistant Examiner US. Cl. X.R. 8-55; 57-14'0