Process for the preparation of a fiber, a fiber and a yarn made from such a fiber

Abstract

A fiber comprising polyethylene-2,5-furan-dicarboxylate, is prepared by melt spinning in a process wherein a molten composition comprising polyethylene-2,5-furan-dicarboxylate having an intrinsic viscosity of at least 0.55 dl/g, determined in dichloroacetic acid at 25 C., is passed through one or more spinning openings to yield molten threads; wherein the molten threads are cooled to below the melting temperature of the composition to yield spun fibers; and wherein the spun fibers are drawn to a linear density in the range of 0.05 to 2.0 tex per fiber. The invention also proves a fiber comprising polyethylene-2,5-furan-dicarboxylate having a linear density of 0.05 to 2.0 tex, wherein the polyethylene-2,5-furan-dicarboxylate has an intrinsic viscosity of at least 0.45 dl/g, determined in dichloroacetic acid at 25 C.

Claims

1. A process for the preparation of a fiber comprising polyethylene-2,5-furan-dicarboxylate, by melt spinning, wherein a molten composition comprising polyethylene-2,5-furan-dicarboxylate having an intrinsic viscosity of at least 0.55 dl/g, determined in dichloroacetic acid at 25 C., is passed through one or more spinning openings to yield molten threads; wherein the molten threads are cooled to below the melting temperature of the composition to yield spun fibers; wherein the spun fibers are drawn to a linear density in the range of 0.05 to 2.0 tex per fiber; wherein the molten composition further comprises at least one polymer different from polyethylene-2,5-furan-dicarboxylate; and wherein the molten composition further comprises polyethylene terephthalate or polyethylene naphthalate.

2. The process according to claim 1, wherein the molten composition comprises from 75 to 100% wt polyethylene-2,5-furan-dicarboxylate, based on the weight of the molten composition.

3. The process according to claim 1, wherein the at least one polymer different from polyethylene-2,5-furan-dicarboxylate has been selected from polyolefins, polyamides, polyesters and combinations thereof.

4. The process according to claim 1, wherein the at least one polymer different from polyethylene-2,5-furan-dicarboxylate is present in an amount of 99 to 75% wt or 1 to 25% wt, based on the weight of the at least one polymer different from polyethylene-2,5-furan-dicarboxylate and polyethylene-2,5-furan-dicarboxylate.

5. The process according to claim 1, wherein the spun fibers are drawn in a secondary drawing step at a draw ratio of 1:1.4 to 1:6.0.

6. The process according to claim 1, wherein the spun fibers are combined to a multifilament yarn before or after being drawn.

7. The process according to claim 1, wherein the molten composition is kept at a temperature of 20 to 70 C. above the melting temperature of the molten composition.

8. The process according to claim 1, wherein the spun fibers are drawn at a temperature of between glass transition temperature and the melting temperature of the polymer composition.

9. The process according to claim 1, wherein the polyethylene-2,5-furan-dicarboxylate has an intrinsic viscosity in the range of 0.55 to 1.55 dl/g, determined in dichloroacetic acid at 25 C.

10. The process according to claim 1, wherein the spun fibers are textured.

11. The process according to claim 1, wherein the fibers after drawing are subjected to a spin finishing step by treating the fibers with a liquid.

12. The process according to claim 1, wherein the fibers after drawing are subjected to a dyeing technique.

13. The process according to claim 1, wherein the polyethylene-2,5-furan-dicarboxylate has been modified by the introduction of a third monomer to facilitate dyeing, which third monomer contains functionalized groups or disturbs the regularity of the chain of the polyethylene-2,5-furan-dicarboxylate.

14. A fiber comprising polyethylene-2,5-furan-dicarboxylate having a linear density of 0.05 to 2.0 tex, wherein the polyethylene-2,5-furan-dicarboxylate has an intrinsic viscosity of at least 0.45 dl/g, determined in dichloroacetic acid at 25 C., wherein the fiber further comprises at least one polymer different from polyethylene-2,5-furan-dicarboxylate, and wherein the fiber further comprises polyethylene terephthalate or polyethylene naphthalate.

15. The fiber according to claim 14, having a linear density of 0.05 to 0.5 tex.

16. The fiber according to claim 14, which has a tenacity of 200 to 1,000 mN/tex.

17. The fiber according to claim 14, wherein the polyethylene-2,5-furan-dicarboxylate has an intrinsic viscosity in the range of 0.45 to 0.85 dl/g, determined in dichloroacetic acid at 25 C.

18. The fiber according to claim 14, wherein the fiber has a birefringence in the range of 0.01 to 0.4.

19. The fiber according to claim 14, wherein the fiber has a crystallinity of at least 5 J/g as determined by Differential Scanning calorimetry (DSC).

20. The fiber according to claim 14, wherein the fiber has been obtained by drawing an undrawn spun fiber at a draw ratio of 1:1.4 and 1:6.0 in a secondary drawing step.

21. The fiber according to claim 14, which has been dyed by a dyeing technique.

22. A yarn, comprising a plurality of fibers according to claim 14.

23. A knit, woven or non-woven article, comprising a yarn according to claim 22.

24. The article according to claim 23, which is selected from a textile, a carpet and a tire cord.

25. The process according to claim 1, wherein the molten composition further comprises polyethylene terephthalate or polyethylene naphthalate in an amount of 99 to 85% wt, based on the total composition.

26. The process according to claim 12, wherein the fibers after drawing are subjected to a dyeing technique selected from the group consisting of carrier or carrier free dyeing, high temperature and high pressure (HTHP) dyeing, thermosol dyeing, plasma techniques, solvent free, supercritical CO.sub.2-based dyeing, dyeing using swelling agents and combinations thereof.

27. The fiber according to claim 19, wherein the fiber has a crystallinity of at least 30 J/g, as determined by Differential Scanning calorimetry (DSC).

28. The fiber according to claim 24, wherein the fiber further comprises polyethylene terephthalate or polyethylene naphthalate in an amount of 99 to 85% wt, based on the total fiber.

29. The fiber according to claim 21, which has been dyed by a dyeing technique selected from the group consisting of carrier or carrier free dyeing, high temperature and high pressure (HTHP) dyeing, thermosol dyeing, plasma techniques, solvent free, supercritical CO.sub.2-based dyeing, dyeing using swelling agents and combinations thereof.

30. The process according to claim 25, wherein the molten composition further comprises polyethylene terephthalate or polyethylene naphthalate in an amount of 99 to 90% wt, based on the total composition.

31. The fiber according to claim 28, wherein the fiber further comprises polyethylene terephthalate or polyethylene naphthalate in an amount of 99 to 90% wt, based on the total fiber.

Description

EXAMPLE 1

(1) A sample of polyethylene-2,5-furandicarboxylate (hereinafter PEF) having a weight average molecular weight Mw of 75,600 determined by GPC with polystyrene standards, corresponding with an intrinsic viscosity of 0.74 dl/g, was melt spun in via a 48-hole spinneret at a temperature of 260 C. The molten threads were cooled and spun. The 48 filaments were combined to a yarn having a linear density of 115 tex, corresponding with a linear density of 2.40 tex per filament. The breaking tenacity was 96 mN/tex and the elongation to break was 239%. (both as determined according to ISO 5079-1995). The yarn as spun was subjected to stretching (drawing) to different draw ratios and at different draw temperatures. The yarn had an IV of 0.67 dl/g, corresponding with a weight average molecular weight of 66,400. The resulting linear densities per filament, breaking tenacities and elongations at break are shown in the Table 1 below.

(2) TABLE-US-00001 TABLE 1 Exp. Temperature, Draw Linear density, Tenacity, Elongation, No. C. ratio tex mN/tex % 1 90 1.5 1.59 156 137 2 90 2 1.20 209 83 3 90 2.5 0.98 247 46 4 90 3 0.80 319 25 5 100 1.5 1.58 146 148 6 100 2 1.20 186 85 7 100 2.5 0.96 230 53 8 100 3 0.77 287 27 9 110 1.5 1.57 123 139 10 110 2 1.19 153 94 11 110 2.5 0.95 182 61 12 110 3 0.56 269 22 13 120 1.5 1.59 116 138 14 120 2 1.19 199 108 15 120 2.5 0.95 220 75 16 120 3 0.81 293 28

(3) The above results show that PEF fibers with good linear densities and excellent strengths can be obtained. The results further show that when the draw temperature is 100 C. or below, the tenacity increases whereas the elongation does not seem to vary over temperature. The higher the draw ratio is, the better is the tenacity and the lower is the elongation at break.

EXAMPLE 2

(4) The same polymer that was used in Example 1 was subjected to a two-step stretching (drawing) process. First the polymer composition was melt spun in the same way as was done in Example 1. A resulting yarn was subsequently preliminarily drawn at 85 C. to a draw ratio of 2.5. In a second stage the preliminarily drawn fiber was further drawn to different final draw ratios in an oven heated to 125 or 130 C. The tenacity and elongation was again determine for each of the resulting yarns. The results are shown in Table 2.

(5) TABLE-US-00002 TABLE 2 Exp. Temperature, Final draw Linear Tenacity, Elongation, No. C. ratio density, tex mN/tex % 17 125 2.75 0.92 161 25 18 125 3 0.84 210 15 19 125 3.25 0.78 263 14 20 130 2.75 0.90 150 17 21 130 3 0.81 237 13 22 130 3.25 0.78 270 14

(6) The results indicate that after a first draw step at relatively low temperature a second step at a higher temperature can be carried out, wherein the variation of the temperature in the second step in the region of 125 to 130 C. hardly plays a role.

EXAMPLE 3

(7) The same polymer that was used in Example 2 and melt spun in the same way. In a first step the spun fibers were drawn at 90 C. to a first draw ratio of 2.4. Then the preliminarily drawn fibers were passed over a hot plate kept at 100 C. and drawn further to a final draw ratio ranging from 3 to 3.6. The results of these experiments are shown in Table 3.

(8) TABLE-US-00003 TABLE 3 Final draw Linear density, Tenacity, Exp. No. ratio tex mN/tex Elongation, % 23 3 0.87 345 22 24 3.2 0.81 368 13 25 3.4 0.76 429 5.4 26 3.6 0.72 485 5.4

(9) The results show that when the draw temperature also in the second step is at most 100 C., the tenacity of the resulting fibers is increased. The yarn showed a melting point of 204-210 C. The crystallinity of the yarn of Experiment No. 23, determined by the net enthalpy of melting via Differential Scanning Calorimetry (DSC), amounted to 14 J/g. The crystallinity of the yarn of Experiment No. 26 amounted to 30 J/g.

EXAMPLE 4

(10) Two samples of PEF, one having a Mw of 85,200 (sample A), corresponding with an intrinsic viscosity of 0.81 dl/g, and the second having a Mw of 111,000 (sample B), corresponding with an intrinsic viscosity of 0.99 dl/g, were melt spun in via a 48-hole spinneret at a temperature of 260 C. The 48 filaments were combined to yarns, one having a linear density of 144.2 tex, corresponding with a linear density of 3.00 tex per filament (yarn from Sample A), and the second having a linear density of 143.3 tex, corresponding with a linear density of 2.99 tex per filament (yarn from Sample B). The yarn from Sample A as spun had an IV of 0.71 dl/g, corresponding with a Mw of 71,600, and the yarn as spun from Sample B had an IV of 0.82, corresponding with a Mw of 86,600. The yarns as spun were subjected to stretching (drawing) to different draw ratio in one or two steps. The draw temperature in the first step was 90 C.; the temperature at the second step was 100 or 150 C. The resulting linear densities per filament, breaking tenacities and elongations at break are shown in the Table 4 below.

(11) TABLE-US-00004 TABLE 4 T, C. DR, DR, Linear Exp. 2.sup.nd 1.sup.st 2.sup.nd density, Tenacity, Bi-refringence Crystallinity, No. Sample step, step step tex mN/tex Elongation, % n, 10.sup.3 J/g 27 A 2 1.45 207 112 33.8 2 28 A 2.5 1.15 253 60 29 A 3 0.98 289 38 66.4 8 30 A 3.5 0.88 336 21 31 A 4 0.71 409 6 142.6 45 32 B 2 1.48 239 63 37.6 33 B 2.5 1.19 302 34 34 B 3 1.03 325 11 101.3 34 35 B 3.5 0.94 447 4.9 118.0 40 36 A 100 2.5 1 1.22 253 72 45.1 2 37 A 100 2.5 1.2 1.02 283 43 64.3 1 38 A 100 2.5 1.4 0.88 331 25 39 A 100 2.5 1.6 0.78 399 8 40 A 100 2.5 1.8 0.70 530 5.7 33 41 B 100 2 1.25 1.21 307 34 80.9 3 42 B 100 2 1.5 1.02 347 12 13.6 8 43 B 100 2 1.6 0.98 422 5.6 117.3 17 44 A 150 2.5 1 1.19 153 116 16.6 2 45 A 150 2.5 1.2 1.00 156 87 27.8 19 46 A 150 2.5 1.4 0.88 312 30 121.4 39 47 A 150 2.5 1.6 0.76 410 4 147.5 42 48 A 150 2.5 1.8 0.68 625 4.9 170.8 45 49 B 150 2.5 1 1.23 280 37 98.4 39 50 B 150 2.5 1.2 1.01 324 6 136.3 39 51 B 150 2.5 1.28 0.96 404 4.6 137.0 46 52 B 150 2.5 1.36 0.90 381 6 39

(12) The results show that when PEF fibers have a Mw 75,000, they have even higher tenacity.

EXAMPLE 5

(13) A sample of PEF having a weight average molecular weight Mw of 89,500, corresponding with an intrinsic viscosity of 0.84 dl/g, was melt spun via a 48-hole spinneret at a temperature of 290 C. The molten threads were cooled and spun. The 48 filaments were combined to a yarn having a linear density of 13 tex. The IV of the yarn was 0.71 dl/g, corresponding with an Mw of 71.800.

(14) The yarn was processed on a Barmag AFK 2 false twist texturing machine to produce textured drawn yarns. Thereto the spun yarn is heated in the texturing machine in an oven, heated to 160 or 170 C. so that it becomes malleable. In this state, it is drawn with a draw ratio of 1.6 or 1.7, and is twisted. Subsequently, the thread is cooled by means of a jet of air and the twist reversed, which creates crimping. At the end of this continuous process, the thus textured yarn is wound. The yarns with a draw ratio of 1.6 had an average linear density of 0.17 tex, the yarns with a draw ratio of 1.7 had an average linear density of 0.16 tex. Samples of the textured yarns were measured as to tenacity and elongation at break. The results, showing the average of 30 samples for each parameter, are shown in Table 5.

(15) TABLE-US-00005 TABLE 5 Exp. No. Temperature, C. Draw ratio Tenacity, mN/tex Elongation, % 53 160 1.6 302 23 54 160 1.7 300 8 55 170 1.6 288 20 56 170 1.7 289 15

(16) This example shows that textured yarns can be made with satisfactory tenacity.

EXAMPLE 6

(17) A sample of PEF, having an intrinsic viscosity of 0.66 dl/g, was used in a number of mixtures with polyethylene terephthalate (PET). The PET used had an intrinsic viscosity of 0.64 dl/g. The polymer, or polymer mixture, was melted to a temperature of 270 C. and melt spun via a 72-hole spinneret at a temperature of 270 C. The molten threads were cooled. The 72 filaments were combined to a yarn. The yarns were drawn in three steps at 60, 100 and 100 C. to a final draw ratio of 2.5. The linear densities per filament of the yarns were determined and found to be 0.560.01 tex. In addition to the tenacity and elongation, also the maximum draw ratio was determined by drawing the yarns in the third step till they broke. The results are shown in Table 6.

(18) TABLE-US-00006 TABLE 6 Exp. Tenacity, Maximum No. PET, % wt PEF, % wt mN/tex Elongation, % draw ratio 57 100 0 145 67.2 4.2 58 99 1 151 59.7 4.2 59 98 2 166 58.2 4.2 60 95 5 158 56.7 4.4 61 90 10 138 69.6 4.2 62 80 20 134 64.6 4.2
The result show that PEF can successfully mixed with PET in various amounts to yield fibers with properties that are similar to those of PET. When the amount of PEF is up to 10% wt, the tenacity is even further improved.

COMPARATIVE EXAMPLE 7

(19) A sample of polytrimethylene-2,5-furandicarboxylate (also known as polypropylene-2,5-furandicarboxylate, hereinafter PPF), was prepared with a number average molecular weight of 30,000. The melting temperature of the polymer was about 178-179 C. Because of the lower melting temperature the polymer was melted to a temperature of 210 C. and melt spun via a 48-hole spinneret. The molten threads were cooled and spun. The 48 filaments were combined to a yarn having a linear density of 110 tex, corresponding with a linear density of 2.29 tex per filament. During spinning the pressure in the spinneret increased such that the spinning had to be interrupted.

(20) The yarns were drawn at different temperatures. Since the glass transition temperature of PPF is about 50-51 C., the draw temperature can be lower than for PEF. Temperatures below 60 C. resulted in yarn breaks. Drawing at a temperature above 80 C. resulted in an undesirably low level of orientation and crystallization in the fiber. Therefore, the draw temperatures were kept between 60 and 80 C.

(21) The yarns obtained were drawn at different draw ratios (DR) in two steps at different temperatures. The draw conditions and the resulting tenacity of the yarns are shown in Table 7.

(22) TABLE-US-00007 TABLE 7 Temperature, Temperature, Linear Exp. DR, 1.sup.st step, DR, 2.sup.nd step, density, Tenacity, No. 1.sup.st step C. 2.sup.nd step C. tex mN/tex Elongation, % 63 2 62 2 70 0.59 130 21 64 2 62 2.25 70 0.53 100 14

(23) The results show that when a PPF fiber has been spun and drawn to a linear density of about 0.5 to 0.6 tex, the tenacity is unsatisfactorily low.

EXAMPLE 8

(24) A sample of PEF having a weight average molecular weight Mw of 57,700, corresponding with an intrinsic viscosity of 0.60 dl/g, was melt spun via a 48-hole spinneret at a temperature of 264 C. The molten threads were cooled, picked up on a roller rotating at a speed of 1500 rpm, and spun. The 48 filaments were combined to a yarn having a linear density of 33.4 tex, corresponding with a linear density of 0.70 tex per filament. The IV of the yarn was 0.48 dl/g, corresponding with an Mw of 43,100.

(25) The yarn was drawn at 110 C., followed by a heat set at 155 C. The resulting yarns and an crystallinity of more than 40 J/g, a Tg of about 80 C. and a melting temperature of 212 C. The shrinkage in boiling water was less than 5%.

(26) Other properties of the yarn are shown in Table 8.

(27) TABLE-US-00008 TABLE 8 Linear density, Tenacity, Exp. No. Draw ratio tex mN/tex Elongation, % 65 (as spun) 0.70 132 223 66 2.5 0.28 239 22