IL33257A - Self-crimpable fibers and filaments and their production - Google Patents

Description

Self-crimpable fibers and filaments and their production B.I.DU PONT NEMOURS AND COMPANY Cj 31528 This invention relates to improved composite filaments and to a process for the production of such filaments.

Composite filaments are well known. Such filaments usually consist of at least two different longitudinally ex-tending components which are arranged in eccentric manner with respect to the filament axis so that the differing shrinkage propensities of the components cause formation of a crimped fiber when the filament is appropriately treated, e.g., with hot water. Such filaments are produced by ex-truding the components in a side-by-side or sheath-core relationship.

In most cases, the composite filaments are maintained in a straight or substantially straight configuration until they are processed into a fabric, the fabric then being sub-jected to heat treatment to crimp the filaments and thereby produce a certain degree of bulkiness which enhances the covering power and aesthetics of the fabric.

While some prior art bicomponent fibers exhibit the characteristics of crimping to a greater degree when exposed to high pressure steams than when crimped in boiling water, such filaments after treatment in boiling water do not exhibit any appreciable difference in degree of crimping or crimp dimensions when subjected to dry heat treatment such as conventional commercial heat setting of fabrics.

This invention provides improved composite fibers and filaments having an improved response to after-treatments used in the manufacture of textile products such as carpets, fabrics, etc. and a process for their production. Surprisingly, thedyeability of the fibers and filaments is markedly changed different crimp dimensions permits a choice in the level of fabric bulk, softness, cover, loopiness and stretch in knit fabrics and pucker and crepe surface in woven fabrics. Thus, a single type of filament may be employed to produce a variety of fabric effects.

/ This Invention provides self-crimpable composite fibers or filaments comprised of at least two continuous, adherent, longitudinally extending, eccentrically positioned synthetic polyamlde components of different composition and shrinkage characteristics, each component being comprised of at least 50 mole percent of at least one type of repeating (recurring) units of the formula: wherein x is 1 or 2, R is the same or different member of the class consisting of hydrogen and methyl, y is 8-14 and S indicates a saturated ring, at least 40 weight percent of the diamino constituent of the repeating units of formula (I) being of a trans-trans stereoisomeric configuration and at least one of the components being a copolymer. Preferably the fibers or filaments consist of two components, x is 1 and R is hydrogen.

In one embodiment of the invention, one component consists essentially of the repeating units of formula (I), while the second component is comprised of a copolyamide con-taining 50-95 mole percent of the repeating units of formula (I). Preferably the copolyamlde contains 5-50 mole percent of repeating units prepared from a member of the class consisting of (l) the same diamine as employed for the formula (I) units and another dicarboxylic acid, and ( 2 ) the same -30 mole percent of the different polyamide units.

In another embodiment, at least one and preferably two of the components are comprised of copolymers containing at least 50 mole percent of repeating units of formula (I), the copolymers being identical except that (l) one copolymer contains at least 5 mole percent more of the repeating units of formula (I) than the second copolymer or (2) one copolymer contains at least 10 weight percent more of the diamino constituents in the trans-trans stereoisomeric configuration than the second copolymer (i.e., at least a 10 weight percent greater content of the trans-trans diamino constituent isomer).

This invention also provides a process for providing composite filaments of this Invention comprising (l) extruding the molten components as defined in this invention to form a composite filament comprising continuous, adherent, longitudinally extending, eccentrically positioned components, (2) quenching the filaments to solidify the components and (3) drawing the filaments. In one embodiment the process includes the further step of passing the yarn through a zone wherein the filaments under low tension are exposed to a turbulent gaseous atmosphere at elevated temperatures. The filaments are preferably drawn about 1.2 to 3X without added heat or at elevated temperatures, e.g. above 100°C.

The components may be extruded in a side-by-side or eccentric sheath-core relation. When maximum bulk is desired, multifilament yarns from the filaments of this invention may be passed through a zone where the filaments are exposed to a turbulent gaseous atmosphere at elevated temperature under low tension to insure that the crimps in the The drawing illustrates graphically the shrinkages at various temperatures of yarns prepared from various polymer compositions which may be employed as components in the bi-component filaments of this invention.

The polyamides of this invention are those conveniently prepared from dicarboxylic acids of the formula : 0 0 tt HO (CHJ •OH '2'y (ID wherein y is an integer in the range of 8-l4. These acids Include decanedioic acid (y»8), undecanedioic acid dodecanedloic acid (y=10), tridecanedioic acid (y=ll), tetradecanedioic acid (ye12), pentadecanedioic acid (y=lj5), and hexadecanedioic acid (y=l4).

The dicarboxylic acids are reacted with diamines of the formula : wherein x is 1 or 2, and R is hydrogen or methyl. The diamine "of formula (III) and in the recurring units of formula (l)_7 can exist in various stereoisomeric or geometric configuration, having trans-trans (tt), cis-cis (cc), and cis-trans (ct) configurations. It is necessary, for the purposes of this invention, that at least 40 weight percent of the diamine constituent be in the trans-trans configuration; at least 55 weight percent trans-trans is preferred. This minimum is generally necessary in order to achieve the desired shrinkage level as well as other filament properties. Among the - total carbon atoms; aromatic acids such as terephthalic acid, isophthalic acid, paraphenylene-diacetic acid, bibenzoic acid, and 2-methyl terephthalic acid. Suitable diamines include the alpha, omega aliphatic diamines of 6-lH carbon atoms such as hexamethylenediamine, 2-methyl hexamethylene-diamine, and ring-containing diamines such as piperazine, substituted piperazines, e.g., dimethylpiperazine, meta- or paraxylylenediamine, 4, 6-dimethylmetaxylylene diamine, para-phenylenediamine and 2, 2-bis( -aminocyclohexyl)propane.

The copolyamlde compositions are comprised of at least one type of recurring unit of formula (I), above, and from about 5 to 50 mole percent of at least one other type of recurring polyamide unit.

The above homopolymers and copolymers can be prepared from the corresponding amide-forming derivatives of the aforesaid diacids (e.g., esters or acid chlorides).

The composite filaments of this invention are usually prepared with substantially equal amounts of two components, i.e., bicomponent filaments with the components in a 50 :50 weight ratio. If desired, however, this ratio may be varied considerably in order to vary the crimp frequency and dimensions or for other reasons. Preferably the relative weights of the components will be held in the range of 30 :70-70 : JO. Some variation in the ratio among the various fila-ments of multi-filament yarns is frequently desirable, however, since this tends to cause the crimps in each filament to be out of phase with respect to the crimps in neighboring filaments in the same yarn, thus producing a bulkier yarn. Such variations tend to occur to some extent in many processes, e.g., a process of the type illustrated h r n since some fluctuation in the com onent ratio will If desired, the relative viscosity of the polymer in the component having the higher shrinkage is higher than that of the polymer in a second component in order to obtain a high crimp recovery when the yarn is stressed.

It is generally preferred that the filament components have a difference in shrinkage greater than about 1$. However, much greater differences are obtainable, e.g., from about k% to about 65$, and are highly preferred for many applications. While it is generally preferable as a practical matter to combine a homopolymer and a copolymer, it is possible, as can be seen from the drawing, to combine two copolymer components to produce crimpable bicomponent filaments .

The filaments of this invention have the charac-terlstlc that they crimp when exposed to hot aqueous solutions as would be expected of a bicomponent fiber but, in addition, when these filaments are exposed to treatments at higher temperature, e.g., with hot air or steam, the shrinkage and crimp characteristics vary with the severity and nature of the treating atmosphere. Also, the dyeability of the filaments varies with the nature of the heat treatment^ i.e., treatment with hot air increases dyeability slightly while treatment with steam reduces dyeability markedly. Thus, various desirable effects may be obtained in textile products such as carpets, knitted fabrics, etc., by varying the after-treatment of the fiber. While some prior art bicomponent fibers exhibit the characteristics of crimping to a greater degree when exposed to high pressure steams than when crimped in boiling water, such filaments after treatment in boiling water do not exhibit any appreciable difference in degree of crim in or crim dimensions when sub ected to dr heat after a hot water treatment, as shown by the filaments of this invention, is very important since such treatments may be employed to finish fabrics on a commercial scale in existing equipment while the use of high pressure steam treatment is frequently not practical, since control of fabric dimensions and tension is required during the heat treatment and this cannot be readily accomplished in available steaming equipment In addition to the above, it has been found that the ability to modify crimp dimension by application of dry heat can be important in reducing surface loops (sometimes referred to as "pickiness ") in knitted fabrics, especially those which are prepared in such manner as to have a soft texture. This condition is sometimes found in knitted fabrics from bicomponent crimped filaments or from filaments crimped in other ways. It has been observed, however, that the "pickiness" of fabrics from the yarns of this invention can be largely eliminated by passing the fabric between hot rolls so that the crimp amplitude is reduced.

Measurements and Tests Relative viscosity, as used herein, signifies the ratio of the flow time in a viscometer of a polymer solution relative to the flow time of the solvent alone. Measurements of relative viscosities given in the examples are made with 3.7 grams of polymer dissolved in 50 ml. of a 1 : 1 mixture of 98-100$ formic acid and phenol at 25°C. unless otherwise specified .

The shrinkage values shown are obtained by boiling a skein of the yarn under a load of 1.5 mg. /denier for > minutes, drying in room temperature air and then heating in air at the indicated temperature for 2 minutes under the same where c is the length of the skein before boiling and d is the final length after heating in air.

EXAMPLES The following examples are illustrative rather than limitative of the invention. Parts, proportions and percentages are by weight unless otherwise indicated. It should also be noted that in the examples, the amount of cis-cis isomer in the diamine does not vary greatly from about 5$; thus by giving the trans-trans content, any diamine isomer mixture of this invention is effectively identified.

EXAMPLE 1 A homopolymer is prepared in an autoclave from an aqueous salt solution containing 50 parts water and 50 parts of the salt of bis( -aminocyclohexyl)methane and dodecanedloic acid. The diamine consists of 80$ tt (trans-trans), 15$ ct (cis-trans), and about $ cc (cis-cis) isomers.

As a viscosity stabilizer, 0.71 mole percent of acetic acid is added. The solution also contains 0.005$ manganous hypophosphite, based on the weight of the salt.

This solution is heated under 300 psig ( 21 .4 atmospheres) pressure for two hours while the temperature is raised to j500°C. The pressure is then reduced to atmospheric while the temperature is raised to 315°C. over a period of 90 minutes and the polymer held under these conditions for two hours followed by an additional hour at 320°C. It is then extruded and cut to flake in the conventional manner.

A copolymer flake is prepared in a similar fashion using diamine containing 70$ of the tt isomer. The dibasic acid used in preparing the salt is a mixture of 9 parts by copolymer is held under a vacuum at the end of the cycle to achieve the desired viscosity level.

The homopolymer, having a relative viscosity of about 22, and the copolymer, having a relative viscosity of about 35 j are melted separately and extruded from pairs of closely adjacent orifices so that the polymer streams coalesce to form 34 blcomponent filaments each containing approximately equal weights of the components. The filament cross-sections are of dog-bone shape. Prior to extrusion the homopolymer is passed through a homogenizer where an antistatic agent, polyethylene ether alcohol of about 20, 000 molecular weight, is injected to provide a concentration of 6 by weight of the polymer. The filaments are air-quenched in the conventional manner and then converged into a yarn and wound into a package. The yarn is then drawn to a ratio of 3.0 by passing the yarn from a feed roll to and around an elongated heating element of about 3 inches (7.6 cm.) in length and having small rollers at either end to facilitate passage of the yarn and then to a draw roll rotating at a peripheral speed of 458 ypm (419 meters/min. ) . The yarn is given three passes around the heating element and three passes around the draw roll and an associated separator roll. The temperature of the heating element is 120°C. After drawing, the yarn is wound into a package in the conventional manner. The denier of the drawn yarn is about 510. Two ends of the drawn yarn are combined and passed through a hot air jet processing device of the type described by Hallden et al. in U.S. 3, 005 , 251 at a temperature of 120°C. and a pressure of 80 psig (6.44 atmospheres) to separate the filaments and produce a randomly crimped yarn, i.e., the crimps in the various filaments are out of phase When this yarn is placed in boiling water for 15 minutes, removed and air dried, it is found to have 9 crimps per inch based on the extended length of the yarn and the crimp elongation is 78 . When the yarn is heated in air at l6o°C. for 10 minutes, the number of crimps increases to 14 while the crimp elongation decreases to 6l indicating a larger number of crimps of lower amplitude. When the yarn is treated with steam at 2 psig (2.7 atmospheres) for 15 minutes, the number of crimps per inch is 12 and the crimp elongation is 67$. Crimp elongation is measured by determining the length (a) of a skein of the yarn in a relaxed state and the length (b) under a load of 0.1 grams per denier. Crimp elongation is calculated from the equation, CE = 100(b-a)/a When untreated yarn, yarn heated in air at l60°C, and yarn treated with steam at 25 psig (2.7 atmospheres) are dyed using Celanthrene Brilliant Blue FPS in a dyebath at about 95°C., the heat-set yarn dyes much darker than the steamed yarn while the untreated yarn is intermediate in dye depth.

A loop-pile carpet is prepared using untreated and steam treated yarns as above. The carpet is piece-dyed as above. The two yarns dye to considerably different depths giving as interesting effect and, in addition, due to the differences in crimping and shrinking characteristics, the tufts formed by the two yarns are quite different in appearance. These contrasts give a desirable aesthetic effect in the finished product.

EXAMPLE 2 Following the general procedure of Example 1, a homo ol mer is re ared from bis 4-aminoc clohex l methane polymer flake having the relative viscosity shown in Table I. During polymerization, a 0 aqueous slurry of Ti02 pigment is added in sufficient amount to provide 0. % by weight of Ti02 as a delusterant in the final polymer. Similarly, a series of copolymers is prepared as in Example 1, except the amount of isophthallc acid used is varied and the quantity of tt isomer in the diamine is also varied for some of the copolymers. These copolymers designated A, B, C, and D are identified as to composition and relative viscosity in Table I. Each of these copolymers is extruded to form side-by-side blcomponent filaments consisting of approximately equal amounts of each component. The side-by-side filaments are formed by extruding the homopolymer and copolymer from 20 pairs of closely adjacent orifices in the same spinneret so that the molten polymer streams coalesce immediately after extrusion to form bicomponent filaments. The components are in a 1:1 weight ratio.

The yarns, A, B, C, and D, corresponding to the bicomponent yarns containing copolymers A, B, C, and D, are air-quenched and wound into packages at 500 ypm (457 meters/min) in the usual manner. The yarns are then drawn on a draw winder; the draw ratio is designated in Table I. In drawing, the yarns are passed over a feed roll, then given one turn around a heated draw pin,* then in contact with a hot plate for a distance of inches (7.6 cm.) and then around the draw roll. The temperatures and speeds are shown in Table I. It should be noted that the yarns do not attain the temperature of the plate because of the short contact time. After drawing, the 20 filament yarn which has a denier of about JO is passed through a tubular air jet device where it is permitted to crimp and retract slightly while being subjected and then wound into a package in the conventional manner, the winding tension being sufficient to remove most of the crimp. The jet (air stream) treatment produces a randomly crimped yarn, i.e., the crimps in the various filaments are out of phase.

When these yarns are removed from the package, the filaments are substantially straight with only a slight curl or crimp. When the yarns are immersed in boiling water, they develop additional helical crimp. Crimp elongation, crimp frequency and amplitude values after boiling in water for minutes under 1.5 milligrams/denier load and air drying at room temperature are given in Table II. Crimp frequency is based on the length of the crimped filament under 1.5 mpd load. The restraining tension of 1.5 milligrams/denier is used because these yarns are to be knitted into tricot fabrics which impose some restraint on the yarn thus impeding crimp formation. When other samples of these yarns are subjected to heated air for 2 minutes, the crimp frequency and amplitude change as indicated in Table II. In contrast, Example 1 involves yarns for carpets where essentially no restraining force exists.

Tricot fabrics are prepared from yarns A, B, C, and D in the conventional manner. It is found that these fabrics can be finished over a range of scouring and heat-setting conditions which permit the selection of conditions to produce fabrics of a desired softness. Scouring the fabrics at a relatively low temperature, e.g., 50°C, permits a moderate degree of shrinkage and some additional coil formation in the yarns. Additional coil formation can be obtained and fabric restraint. Fabric bulk developed at several temperatures is illustrated in Table II. Finishing at temperatures over the range of 150°C. to 190°C. and restraining the fabric to maintain a low fabric weight generally produces fabrics which are lower in bulk and softness. Finishing at temperatures over the same temperature range under low restraint produces fabrics of increased weight and a higher degree of bulk and softness than when finished under high restraint. When the scouring is conducted at a higher temperature, e.g., 95°C., the amount of shrinkage and coil formation is increased resulting in a high weight fabric requiring a considerable amount of stretch during the heat-setting procedure to obtain a low fabric weight. On the other hand, heat-setting while maintaining high fabric weight or permitting moderate shrinkage of the fabric can produce fabrics with high bulk and good softness. If excessive shrinkage is allowed to occur with high temperatures, fabric bulk and softness are decreased.

TA3LE II *» «X . *Buik measured after 50°C. H O treatment **Bulk measured after l65°C. heat treatment ***Bulk "measured -.after 180°C. .heat treatment EXAMPLE 3 A homopolymer and copolymer are prepared following the general procedure of Example 2 except that the copolymer is prepared from dodecanedioic acid and a mixture of bis(4-aminocyclohexyl)methane (95$ tt isomer) and hexamethylene-diamine, the final copolymer containing 25$ by weight ( 30 mole percent) of hexamethylene dodecanedlamide units. The homopolymer having a relative viscosity of 44 and the copolymer having a relative viscosity of 69 are extruded to form a bl-component filament yarn and the yarn processed as described in Example 2 except that in drawing a ratio of 2. 2 is used, the drawing pin temperature is 120°C. and the hot plate temperature is 190°C. In the jet device, the yarn is permitted to relax 6. $ while being subjected to an air stream. at 45 psig. (4.06 atmospheres) and 190°C. temperature. When the yarn is subjected to boiling water, dried and then heated in air at various temperatures under 1 .5 milligrams/denier restraining force, the crimp dimensions change markedly. At 150°C. the yarn contains 25 crimps/inch (9. 8 crimps/cm.) and the crimp amplitude is 8.0 mils (0.203 mm.). When the temperature is increased, the crimp frequency increases and the amplitude decreases so that at 210°C. the yarn contains 50 crimps/inch ( 19.7 crimps/cm.) and the amplitude is 4.7 mils (0. II9 mm. ) .

EXAMPLE 4 This example illustrates the shrinkages at various temperatures of several different, monocomponent filaments made of homo and copolymers as shown in the drawing.

The homopolymer and copolymers are prepared following the general procedure of Example 1. Copolymer (l) is identical with the copolymer of Example 3. Copolymer (2 ) is ,.

D of Example 2 except that the trans-trans Isomer content Is 94$. Copolymer (4) Is Identical in composition and isomer content with copolymer B of Example 2. The homopolymer (5) composition and isomer content is identical with that of the homopolymer of Example 2. Copolymer (6) is the same as (4) except that the tt isomer content is These polymers are extruded as monocomponent filaments, the filaments air quenched and the yarn wound into packages. The yarns are then drawn substantially as described in Example 2, the draw pin temperature being 120°C, the hot plate temperature l60°C, the draw roll speed 250 yards/min. (229 meters/min.) and the draw ratio 5.0 X. The final yarns are 3 -36 denier and contain 13 filaments.

EXAMPLE 5 A copolymer is prepared in an autoclave from an aqueous salt solution containing 50 parts water and 50 parts of the salt of bis(4-aminocyclohexyl)methane (70$ tt) and a mixture of sebaclc and isophthalic acids, the mixture containing sufficient isophthalic acid to provide 20 by weight (21.6 mole percent) of isophthalamide units In the final polymer. The sebaclc acid used in this and subsequent examples is a technical grade acid containing - $ of a mixture of undecanedlolc and dodecanedlolc acids as an impurity. This solution is heated under 300 psig (21.4 atmospheres) pressure for two hours while the temperature is raised to 325°C The pressure is then reduced to atmospheric while the temperature is raised to 335°C. over a period of 90 minutes, and the polymer is then held at a temperature in the range of 325-335°C. for two hours, the autoclave being flushed with nitrogen during this period. The polymer is then ex Following the general procedure used in preparing the copolymer, two batches of homopolymer are prepared from the salt of bis(4-aminocyclohexyl)methane (70 tt) and sebacic acid. In preparing one batch, 2.5 mole percent of acetic acid is added to the salt solution while no acetic acid is added in the preparation of the other batch. The two batches of homo-polymer are mixed together in equal proportions to give a polymer having a relative viscosity of 39.

The homopolymer and copolymer are extruded to form 34 filaments containing approximately equal amounts of the two components as described in Example 1. The filaments are then air quenched in the conventional manner and converged into a yarn and wound into a package. The yarn is then removed from the package and drawn at a draw ratio of 1.35 by passage around a feed roll, then over a 90°C, 12-inch (3Ο.5 cm.) hot plate and around a draw roll rotating at a higher speed than the feed roll. The yarn is given 12 passes around the feed roll and an associated separator roll and 10 passes around the draw roll and its associated separator roll. The yarn is then wound into a package at 50 ft./min. (15.2 meters/min. ) .

When samples of the yarn prepared as above are boiled off, heated in hot air at various temperatures, and in steam at various temperatures, and tested as described in Example 1, the crimp characteristics vary as shown in the table following.

Table III Environment HgO Air Steam Temp., °C. 100 100 I30 I6O 190 108 121 131 Crimp Elongation, ig4 124 ι4γ 17g 85 l6l 158 13 Frequency, Crimps/Inch 9>2 8.5 10.5 16.3 38.5 10.3 24.523.0 Frequency, Crimps/cm. 5<6 5< >1 6.4 15.1 4.1 9.61L0 When a yarn is prepared as described above except that the draw ratio is 1.8 and the filaments contain about 38$ by weight of the homopolymer component and about 62$ by weight of the copolymer component, the crimp characteristics, determined as in Example 1, are as shown in Table IV below.

Table IV Environment HgO Air Steam Temp., °C. 100 100 Γ30 Ϊ60 190 108 121 131 Crimp Elongation,# 293 215 212 213 1 8 262 226 214 Frequency, Crimps/Inch 17.6 20.0 17.8 20.9 34.0 18.2 24.5 27.7 Frequency, Crimps/cm. 6.9 7.9 7.0 8.2 13. 7.2 9.6 10.9 Crimp Amplitude, Mils 23 20 20 19 12 22 l6 l6 Crimp Amplitude,mm. 0.6 0.5 0.5 0.5 0.3 0.6 0.4 0.4 EXAMPLE 6 A homopolymer is prepared following the general procedure of Example 1 from the salt of 70 tt, bis(4-amino-cyclohexyl)methane and dodecanedioic acid. The relative viscosity of the polymer is 3^. A copolymer is prepared as in Example * except that the relative viscosity is 39. The two polymers are processed into drawn yarn as described in Example 5, except that the draw ratio is 1.8. The crimp characteristics of the final yarn, determined as in Example 1, after boiling in water and in steam and heated air, at various temperatures, are shown in the following table.

Table V Environment HgO Air Steam Temp.,°C. 100 100 130 ΙδΟ 190 108 121 131 Crimp Elongation,# I63 l40 138 170 121 167 174 193 Frequency, Crimps/Inch 8.3 13.2 11.0 15.1 37.8 11.5 20.5 27.3 Frequency, Crimps/cm. 3 - 3 5.2 4.3 5.9 14.9 4.5 8.1 10.8 - EXAMPLE 7 A homopolymer having a relative viscosity of 46 is prepared from the salt of bis(4-aminocyclohexyl)methane (70 tt) and sebaclc acid following the procedure of Example 2. In a similar fashion, a copolymer is prepared from a salt solution containing 48 parts water and 52 parts of the salt of bis(4-aminocyclohexyl)methane and sebaclc acid with the addition of sufficient epsilon caprolactam to provide 10 by weight (27 mole percent) of caproamide units in the final polymer. The homopolymer and copolymer are extruded to form 6 bicomponent filaments, the filaments are quenched and wound into a package following the general procedure of Example 1 .

The yarn is then drawn at a draw ratio of 3.0 over a 95° C. hot plate as described in Example 2, except that 8 passes around the feed roll and 10 passes around the draw roll are employed and the windup speed is 100 yds./min. ( 30.5 meters/min) . The crimp characteristics of the final yarn, determined as in Example 1, after boiling in water, and after heating in air and steam at various temperatures, are shown in the table below.

Table VI Environment ¾o Air Steam Temp. , °C. 100 100 130 I60 1 0 108 121 131 Crimp Elongation, 215 126 134 146 142 143 157 146 Frequency, Crimps/Inch 8.9 7.2 8.1 11.7 12. 8 8.9 8.7 9.5 Frequency, Crimps/cm. 3.5 2.8 3.2 4.6 5.0 3.5 3. 3.6 Crimp Amplitude, Mils 40 50 40 30 30 40 50 50 Crimp Amplitude,mm. 1.0 1.3 1.0 0.8 0. 8 1.0 1.3 1.3 EXAMPLE 8 Following the general procedure of Example 1 , a homopolymer is prepared from the salt of bis(4-aminocyclohexyl) copolymer Is prepared from the salt of bis ( -aminocyclohexyl)-methane (70 tt) and a mixture of dodecanedioic and isophthallc acids, the mixture containing sufficient isophthallc acid to provide 10 by weight (11.7 mole percent) of isophthalamide units in the final polymer. This copolymer has a relative viscosity of 33.

The homopolymer and copolymer, in equal amounts by weight, are extruded in side-by-side relation from the same orifices of a spinneret to form 3 round, bicomponent filaments. The filaments are air quenched and converged into a yarn in the conventional manner. The yarn is cold-drawn in two stages to a draw ratio of 3.0 using power-driven rollers to affect the drawing. From the second draw roll, the yarn is given six passes around a heated roll at 170° C. and is then wound into a package at a speed of 1795 yds./min. (l64l meters/mln). The filaments in the final yarn are of 7 denier.

A number of ends of the yarns are combined to form a tow and the tow is mechanically crimped in a stuffer box crimper. The tow is then cut into 4-inch (10.2 cm.) staple in the conventional manner. The staple is carded and then pin drafted to form sliver. The sliver is wet in cold water, centrifuged, and then heated at l49°C. in air for 10 minutes to dry the sliver and develop bicomponent crimp in the filaments. The sliver is spun into yarn and the yarn processed into a plain weave fabric. The fabric is scoured and dyed in the conventional manner and heat-set at 177°C. The fabric is observed to be lofty and bulky and has attractive aesthetics. When a fabric is prepared in identical fashion, except that the step of wetting and heating the sliver to develop crimp is omitted, the resulting fabric is hard and stiff.

The preferred filaments are those consisting of two may be added if desired for any reason. The components may be extruded in side-by-side or sheath-core relation. If a sheath-core filament is prepared, the core should be highly eccentric with respect to the fiber axis to provide the maximum crimp. The relative amounts of components in the filament may also be varied to achieve the optimum results.

The filaments of this invention may contain suitable heat stabilizers, antioxidants, light stabilizers, ultraviolet light absorbers, delusterants, pigments, dyes, and the like. Polymer additives may also be present to reduce static propensity or to improve dyeabillty, soil repellence, crease resistance, hand, water repellency, wickability, strength, elongation, modulus, or melting point of the fiber.

The filaments may be of round or non-round cross sections as desired. Non-round cross sections such as heart shape, cruciform shape, multilobal shape, shield shape or other shapes may be employed as desired.

If desired, the filaments of this invention may contain a durable antistatic agent. The antistatic agent should be present in a concentration of at least 2$ by weight of the polymer and may be added to one of the components or all of the components in the filament as desired. Suitable antistatic agents include the high molecular weight poly-(alkylene ethers), i.e., those in the molecular weight range of I3OO to 200, 000. Suitable antistatic agents are disclosed in British Patent 963, 320.

The filaments of this invention may be used in continuous lengths as monofil or in multifilament yarns or may be cut into staple lengths if desired. In addition to their usefulness in carpets, they may be used to advantage in

Claims (2)

1. ( WHAT IS CLAIMED IS: 1. Self-crimpable composite fibers or filaments comprised of at least two continuous, adherent, longitudinally extending, eccentrically positioned synthetic polyamlde components of different composition and shrinkage characteristics^ each component being comprised of at least 50 mole percent of at least one type of repeating (recurring) units of the formula : wherein x is 1 or 2, R is the same or different member of the class consisting of hydrogen and methyl, y is 8-14 and S indicates a saturated ring, at least 40 weight percent of the diamino constituent of the repeating units of formula (I) being of a trans-trans stereoisomeric configuration and at least one of the components being a copolymer.

2. The fibers or filaments of claim 1 wherein two components are present, x is 1 and R is hydrogen. 5. The fibers or filaments of claim 2 wherein at least one of the components consists essentially of repeating units of formula (I). 4. The fibers or filaments of claim 3 wherein at least 5 weight percent of the diamino constituents of one of the components differs in stereoisomeric configuration from the diamino constituent in the other component. 5. The fibers or filaments of claim 2 wherein the trans-trans diamino constituent isomer content in one of the 6. The fibers or filaments of claim 2 wherein one of the components is a copolymer comprised of between 50 and 95 mole percent of at least one type of repeating unit of formula (I). 7. The fibers or filaments of claim 2 wherein one of the components is a copolymer comprised of between 70 and 90 mole percent of at least one type of repeating unit of formula (I). 8. The fibers or filaments of claim 2 wherein one of the components is a copolymer consisting essentially of a first type of repeating unit of formula (I) and a second type of repeating unit wherein either the diamino constituent or the dicarbonyl constituent are the same as that of the first type of repeating unit. 9. The fibers or filaments of claim 6 wherein one of the components is comprised of at least 5 mole percent more recurring units of formula (I) than the other component. 10. The fibers or filaments of claim 2 wherein the difference in shrlnkability of the components is at least one percent. 11. The fibers or filaments of claim 2 wherein the difference in shrlnkability of the components is -6 $. 12. The fibers or filaments of claim 2 wherein one of the components comprises 50-70 weight percent of the filament. 1>. The fibers or filaments of claim 12 wherein each of the components comprises approximately 0 weight percent of the filaments. 15. The fibers or filaments of claim 2 wherein the trans-trans diamino constituent isomer content is at least 55 weight percent. 16. Process for providing composite filaments of claim 1 comprising (l) extruding the molten components as defined in claim 1 to form a composite filament comprising continuous, adherent, longitudinally extending, eccentrically positioned components, (2) quenching the filaments to solidify the components and (3) drawing the filaments. 17. The process of claim 16 comprising the further step of passing the yarn through a zone wherein the filaments under low tension are exposed to a turbulent gaseous atmosphere at elevated temperatures.