POLYMER FILLED POLYOLEFIN FIBER

Abstract

The present invention relates to a polyolefin fiber comprising polymeric structures, wherein the polymeric structures individually comprise a polycondensate and a functionalized polymer, and the polyolefin fiber is a gel-spun high-performance polyethylene fiber that has a tenacity of at least 1 N/tex. The polymeric structures are immiscible with and dispersed in the polyethylene fiber. The gel-spun high-performance polyethylene fiber is a gel-spun ultrahigh molecular weight polyethylene fiber. The present invention further relates to a process for making the polyolefin fiber comprising the steps of: melt-mixing the polycondensate or a polycondensate containing at least one additive, the functionalized polymer, and optionally the thermoplastic polymer and/or the at least one additive, to form polymeric structures; mixing polyolefin powder, the polymeric structures and a solvent to form a mixture; and spinning and drawing the mixture obtained in step ii) to form the polyolefin fiber comprising the polymeric structures.

Claims

1. A polyolefin fiber comprising polymeric structures, whereby the polymeric structures individually comprise a polycondensate and a functionalized polymer, and wherein the polyolefin fiber is a gel-spun high-performance polyethylene (HPPE) fiber having a tenacity of at least 1 N/tex whereby the polymeric structures are immiscible with and dispersed in the polyethylene fiber.

2. The polyolefin fiber according to claim 1, wherein the gel-spun high-performance polyethylene fiber is a gel-spun ultrahigh molecular weight polyethylene fiber.

3. The polyolefin fiber according to claim 1, further comprising a thermoplastic polymer.

4. The polyolefin fiber according to claim 1, wherein the polymeric structures are dispersed particles or dispersed fibers in the HPPE fiber and preferably further comprise at least one additive.

5. The polyolefin fiber according to claim 1, wherein the amount of the polycondensate is at least 0.1 wt % and at most 50 wt %, based on the total composition of the fiber.

6. The polyolefin fiber according to claim 1, wherein the amount of the functionalized polymer is at least 0.01 wt % and at most 50 wt %, based on the total amount of the polycondensate.

7. The polyolefin fiber according to claim 1, wherein the polycondensate is selected from a group consisting of a polyester, a polyamide and copolymers thereof.

8. The polyolefin fiber according to claim 1, wherein the functionalized polymer is selected from a group consisting of grafted (co)polyethylene and poly (glycidyl methacrylate).

9. The polyolefin fiber according to claim 1, wherein the tenacity of the high-performance polyethylene fiber comprising the polymeric structures is at least 1.5 N/tex.,

10. The polyolefin fiber according to claim 3, wherein the polymeric structures have a particle size, d50, of at least 50 nanometers and at most 1000 nanometers.

11. The polyolefin fiber according to claim 3, wherein the thermoplastic polymer is any polymer having a density as measured according to ISO1183-2004 in the range from 875 to 1000 kg/m.sup.3.

12. The polyolefin fiber according to claim 11, wherein the thermoplastic polymer is selected from a group consisting of a homopolymers of ethylene, homopolymers of propylene, ethylene copolymers and propylene copolymers, and/or mixtures thereof.

13. A process for making the polyolefin fiber according to claim 1 comprising the steps of: i) melt-mixing the polycondensate or a polycondensate containing at least one additive, the functionalized polymer, and optionally the thermoplastic polymer and/or the at least one additive, to form polymeric structures; ii) mixing polyolefin powder, the polymeric structures and a solvent to form a mixture; and iii) spinning and drawing the mixture obtained in step ii) to form the polyolefin fiber comprising the polymeric structures, as defined in any of the preceding claims.

14. A process according to claim 13 wherein step ii) can be performed by mixing the polyolefin powder and a solvent to form a first mixture; mixing the polymeric structures and a solvent to form a second mixture where after both first and second mixtures are mixed together.

15. An article comprising the polyolefin fiber according to claim 1.

16. The article according to claim 15, wherein the article is a fabric.

Description

FIGURES

[0085] FIG. 1 represents a cross section of a HPPE fiber comprising the dispersed and immiscible polymeric structures (1) or droplets (1), (2) refers to HPPE optionally comprising a thermoplastic polymer.

[0086] FIG. 2 represents a cross section of two neighbouring HPPE fibers containing the polymeric structures or droplets taken by Energy Dispersive X-ray (EDX) spectroscopy

EXAMPLES

[0087] Five samples of polymeric structures in the form of solid mixtures were prepared via masterbatch by mixing in the solid state in a tumbler having the quantities of the raw materials stated in Table 1. The resulting solid mixtures were metered with the aid of a K-tron metering unit via the throat to a twin-screw extruder (ZE 25UTS from Berstorff), and in this extruder converted into five polymeric structures compositions (MB01-MB05). Polyamide-based masterbatches (MB01, MB02 and MB03) were made in the extruder with a throughput of 20 kg/h at a speed of 400 rpm. The feed zone, barrel, die and outlet temperature of the material are respectively 20, 240, 240 and 300° C. Polyester-based masterbatches (MB04 and MB05) were made with a throughput of 23 kg/h at an extruder speed of 300 rpm. The feed zone, barrel, die and outlet temperature of the material are respectively 20, 260, 260 and 295° C.

TABLE-US-00001 TABLE 1 P3 P1, wt. % P2, wt. % wt. % P1-1 P1-2 P1-3 P1-4 P1-5 P2-1 P2-2 P3-1 MB01 30 — — — — 70   — — MB02 — — 30 — — 7.5 — 62.5  MB03 — — — 30 — 7.5 — 62.5  MB04 — 30 — — — — 9 61   MB05 — — — — 30 — 9 61  

Examples 1-10 (Ex. 1-10)

[0088] Each MB01-MB05 sample was then dissolved in decalin batches (95 wt % batch and 5 wt % decalin) of about 15 liters, stirring under N.sub.2 for about 1 hour at about 110° C. to form five different suspensions (suspension I-V).

[0089] Separately, a suspension of UHMWPE powder (M-1) was obtained in decalin, with a concentration of 9 wt. % (suspension VI).

[0090] Each of suspension I-V was mixed with suspension VI in a twin-screw extruder having a screw diameter of 25 mm and being equipped with a gear pump to form a mixture. Each mixture obtained was then heated in this way to a temperature of 180° C. The mixture was then pumped through a spinneret having 64 holes, each hole having a diameter of 1 millimeter. The so obtained filaments were drawn in total with a factor of 80 and dried in a hot air oven. After drying, the filaments were bundled and wound on a bobbin.

[0091] The composition and properties of fibers obtained according to the Examples 1-10 are shown in Table 2.

Comparative Experiments A-B (CE-A, CE-B)

[0092] CE-A was performed in the same way as described for Examples 1-10, with the only difference that suspensions I-V were not used, but only suspension VI was added to the extruder to form an (unfilled) UHMWPE fiber.

[0093] CE-B: was performed in the same way as described for Examples 1-10, with the only difference that, instead of using suspensions I-V, inorganic particles of zeolite (commercially available under the tradename Ultrastable Y Zeolide, from ACS Materials, particle size distribution d50 of 6 micron) were used that was mixed with suspension VI to form a zeolite-filled UHMWPE fiber.

[0094] The composition and properties of fibers obtained according to CE A-B are shown in Table 2.

TABLE-US-00002 TABLE 2 Modulus Elongation HPPE HPPE Filler HPPE at break fiber fiber HPPE Filler amount, fiber, HPPE Titer, Tenacity, fiber type wt % cN/dtex fiber, % dtex cN/dtex CE-A none none 1085.1 3.3 444 31.7 CE-B zeolite 10 652 3.2 446 23.7 Ex. 1  MB01  5 1028.2 3.4 450 32.8 Ex. 2  MB01 10 972.9 3.3 446 32.1 Ex. 3  MB02  5 1008.9 3.5 452 32.8 Ex. 4  MB02 10 904.9 3.4 443 30.2 Ex. 5  MB03  5 1001.9 3.5 444 32.8 Ex. 6  MB03 10 972.5 3.4 447 32.2 Ex. 7  MB04  5 1033.8 3.6 441 33.5 Ex. 8  MB04 10 915.2 3.5 455 30.9 Ex. 9  MB05  5 1018.8 3.6 445 33.6 Ex. 10 MB05 10 962.2 3.5 446 33.0

Examples 11-22

[0095] Subsequently, the HPPE fibers obtained according to Examples 1-10 and CE-A and CE-B (Dyneema® 440-SK65 fibers) were knitted on a flat knit 13 gauge Shima Seiki knitting machine into a fabric with areal density of 260 grams per square meter in a single jersey construction.

[0096] The washed and rinsed fabrics were then subjected to coloring processes with 2 wt % based on the dry fabric of Dark Red Serilene FL dye from Yorkshire.

[0097] The dye auxiliaries (2 g/l Univadine DFM, used as diffusion agent) and then the dye were added successively to water, in a dye bath, at a temperature of 50° C. The amounts of auxiliaries and the dye where each 2 wt % based on the weight of the dry fabric. The pH was set to 4.5 using acetic acid. The rinsed fabric was then submerged in the dye bath (approximately 1 liter for 100 g fabric) and then the dye bath temperature was raised (with a rate of 0.8° C./min) to a temperature of 130° C. and kept constant at this temperature for 60 min. The bath was then cooled down rapidly (with a rate of 2° C./min) to 60° C. before the liquid was drained. The dyed fabric was successively rinsed with hot (70° C.) and cold (15° C.) water. The so obtained fabrics were air dried for 24 hours at ambient conditions.

[0098] The so obtained colored fabrics have been evaluated for color intensity as reported in Table 3.

TABLE-US-00003 TABLE 3 ΔE cmc Crocking HPPE (CMC Wet Dry Wash, Wash, Fabric fiber 2:1) Warp Weft Warp Weft Sublimation 40° C. 60° C. Ex. 11 CE-A 0   4-5 4-5 4 4 2-3 4-5 3-4 Ex. 12 CE-B  4.14 4-5 4-5 4 4 3 4.5 4 Ex. 13 Ex. 1   1.70 4-5 4 4 3-4 3 4-5 4-5 Ex. 14 Ex. 2   1.53 4 4 3-4 3-4 4 4 4 Ex. 15 Ex. 3   1.39 4 4 4 3 3 4 4 Ex. 16 Ex. 4   2.15 4-5 3-4 3-4 3-4 4 4 4 Ex. 17 Ex. 5   1.94 4-5 3-4 4 3-4 3 4 3-4 Ex. 18 Ex. 6   2.60 4-5 3 3 3 3-4 4 3 Ex. 19 Ex. 7   2.50 4 4 4 3-4 3-4 4-5 4 Ex. 20 Ex. 8   4.68 4-5 4 4 3-4 4 4-5 4 Ex. 21 Ex. 9   2.67 4-5 4 3-4 3-4 3-4 4 4 Ex. 22 Ex. 10  3.60 4-5 4 4 3-4 4 4 3-4

[0099] The results obtained by applying the fiber according to the invention (Examples 1-10 and 13-22) compared with the results according to prior art (CE-A, CE-B and Ex. 11-12) clearly show that the fabrics containing the polymeric structures-filled HPPE fibers according to the present invention have good colourability and colour fastness (i.e. ΔE cmc values of higher than 1, with ΔE cmc being a known parameter used in the art and showing (visual) difference in color between fabrics; crocking and wash values of at least 3-4; and sublimation values of at least 3, see Table 3) and fiber tenacity values that remain at very high level even when increasing the amount of polymeric structures in the fiber (Table 2).