Multifilament polyester fibres

Abstract

The present invention concerns a multifilament fibre comprising at least one polymer comprising a polyester, and at least one filler comprising calcium carbonate. The present invention further relates to a process of producing such a multifilament fibre as well as the use of calcium carbonate as filler in a multifilament fibre comprising at least one polymer comprising a polyester.

Claims

1. A multifilament fibre comprising at least one polymer comprising a polyester, and at least one filler comprising calcium carbonate, wherein the calcium carbonate is present in the multifilament fibre in an amount of at least 2 wt.-%, based on the total weight of the multifilament fibre and the calcium carbonate is a surface-treated calcium carbonate comprising on at least a part of its accessible surface area a treatment layer comprising a hydrophobising agent, where the hydrophobising agent is selected from a phosphoric acid ester blend of one or more phosphoric acid mono-ester and/or reaction products thereof and one or more phosphoric acid di-ester and/or reaction products thereof and mixtures thereof.

2. The multifilament fibre of claim 1, wherein the polyester is selected from the group consisting of a polyglycolic acid, a polycaprolactone, a polyethylene adipate, a polyhydroxyalkanoate, a polyhydroxybutyrate, a polyalkylene terephthalate, a polyethylene terephthalate, a polytrimethylene terephthalate, a polybutylene terephthalate, a polyethylene naphthalate, a polylactic acid, or a mixture thereof, or copolymers thereof.

3. The multifilament fibre of claim 1, wherein the polyester is a polyethylene terephthalate and/or a polybutylene terephthalate.

4. The multifilament fibre of claim 1, wherein the calcium carbonate has a weight median particle size d50 from 0.1 to 3 μm.

5. The multifilament fibre of claim 1, wherein the calcium carbonate is present in the multifilament fibre in an amount from 2 to 50 wt.-%, based on the total weight of the multifilament fibre.

6. The multifilament fibre of claim 1, wherein the multifilament fibre has a linear mass density from 284 to 4000 dtex.

7. A textile article comprising at least one multifilament fibre according to claim 1.

8. The textile article according to claim 7, wherein said textile article is selected from construction products, consumer apparel, industrial apparel, medical products, home furnishings, protective products, packaging materials, cosmetic products, hygiene products, filtration materials, hoses, power belts, ropes, nets, threads, tire cords, auto upholsteries, sails, floppy disk liners, or fibrefills.

9. A process for producing a multifilament fibre comprising the steps of a) providing a mixture comprising at least one polymer comprising a polyester and at least one filler comprising calcium carbonate, b) melting the mixture of step a) and passing the same through shaped orifices to form a multifilament fibre, and c) quenching the multifilament fibre, wherein the calcium carbonate is present in the multifilament fibre in an amount of at least 2 wt.-%, based on the total weight of the multifilament fibre and the calcium carbonate is a surface-treated calcium carbonate comprising on at least a part of its accessible surface area a treatment layer comprising a hydrophobising agent, where the hydrophobising agent is selected from a phosphoric acid ester blend of one or more phosphoric acid mono-ester and/or reaction products thereof and one or more phosphoric acid di-ester and/or reaction products thereof and mixtures thereof.

10. The process of claim 9, wherein the mixture of step a) is a mixture of a masterbatch and an additional polymer, wherein the masterbatch comprises at least one polymer comprising a polyester and at least one filler comprising calcium carbonate.

11. The process of claim 9, wherein the process further comprises a step d) of drawing the multifilament fibre.

12. A process for producing a textile article comprising incorporating and/or manipulating at least one multifilament fibre according to claim 1 to produce the textile article.

13. The multifilament fibre according to claim 1 and/or a textile article comprising at least one multifilament fibre according to claim 1, wherein the multifilament fibre and/or textile article is suitable for use in construction products, waterproofing, thermal insulation, soundproofing, roofing, consumer apparel, upholstery and clothing industries, industrial apparel, medical products, home furnishings, protective products, packaging materials, cosmetic products, hygiene products, filtration materials, agritechnical applications, building applications, geotechnical applications, industrial applications, medical applications, transporting, ecotechnical applications, packaging applications, personal protection, property protection, or sport applications.

14. The multifilament fibre of claim 1, wherein the calcium carbonate has a weight median particle size d50 from 1.2 to 2.0 μm.

15. The multifilament fibre of claim 1, wherein the calcium carbonate is present in the multifilament fibre in an amount from 10 wt.-% to 30 wt.-%, based on the total weight of the multifilament fibre.

16. The multifilament fibre of claim 1, wherein the multifilament fibre has a linear mass density from 294 to 4000 dtex.

17. The process of claim 9, wherein the mixture of step a) is a mixture of a masterbatch and an additional polymer, wherein the masterbatch comprises at least one polymer comprising a polyester and at least one filler comprising calcium carbonate, and in the masterbatch the calcium carbonate is present in an amount from 40 wt.-% to 75 wt.-%, based on the total weight of the masterbatch.

18. The process of claim 12, wherein the incorporating and/or manipulating comprises layering, plaiting, braiding, knotting, weaving, knitting, crocheting, tufting, collecting on a surface or a carrier, bonding, thermal point bonding, calendering, ultrasonic bonding, hydroentanglement, needling, through-air bonding, dry laying, wet laying, direction orientation, creping, or embossing.

19. The multifilament fibre of claim 1, wherein the multifilament fibre has a linear mass density from 403 to 1500 dtex.

20. The process of claim 9, wherein the multifilament fibre has a linear mass density from 284 to 4000 dtex.

Description

EXAMPLES

1. Measurement Methods and Materials

(1) In the following, measurement methods and materials implemented in the examples are described.

(2) Particle Size

(3) The particle distribution of the calcium carbonate filler was measured using a Sedigraph 5120 from the company Micromeritics, USA. The method and the instruments are known to the skilled person and are commonly used to determine grain size of fillers and pigments. The measurement was carried out in an aqueous solution comprising 0.1 wt.-% Na.sub.4P.sub.2O.sub.7. The samples were dispersed using a high speed stirrer and supersonics.

(4) Titer or Linear Density

(5) The titer or linear density [dtex] was measured according to EN ISO 2062 and corresponds to the weight in grams of 10,000 m yarn. A sample of 25 or 100 metres was wound up on a standard reel under a pretension of 0.5 cN/tex and weighted on analytical scale. The grams per 10,000 m yarn length were then calculated.

(6) Tenacity, Maximum Force and Elongation at Maximal Load

(7) The tenacity was calculated from the breaking force and the linear density, and expressed in centinewton per dtex [cN/dtex]. The test was carried out on a dynamometer with a constant stretching speed. The maximum force is the force which can be maximally applied on a yarn and is expressed in Newton [N]. The elongation is the increase of the length produced by stretching a yarn to its maximal load and is expressed as a percentage [%] of its initial length. Applicable standards for these tests are EN ISO 5079 and ASTM D 3822.

(8) Ash Content

(9) The ash content in [%] of the fibres and the masterbatches was determined by incineration of a sample in an incineration crucible which is put into an incineration furnace at 570° C. for 2 hours. The ash content is measured as the total amount of remaining inorganic residues.

2. Materials

(10) PET: Polyethylene terephthalate, 4060, commercially available from INVISTA Resins & Fibres GmbH, Germany (intrinsic viscosity: 0.66-0.68 dl/g; carboxylic endgroups <50 meq/kg; diethylene glycol ≤1.1 wt.-%; amorphous polymer; crystallization at 140-180° C. for 30-60 min). Data taken from suppliers Technical Data Sheet (TDS).

(11) PBT: Polybutylene terephthtalate, Valox 315, commercially available from Sabic Innovative Plastics BV, Netherlands (melt viscosity: 7500 poise; Melt volume rate, MVR at 250° C./1.2 kg: 6 cm.sup.3/10 min). Data taken from suppliers Technical Data Sheet (TDS).

(12) CC1: Ground calcium carbonate, available from Omya International AG, Switzerland (d.sub.50:1.7 μm; d.sub.98:6 μm, untreated).

(13) CC2: Ground calcium carbonate, commercially available from Omya International AG, Switzerland (d.sub.50:1.7 μm; d.sub.98:6 μm), surface-treated with 1 wt.-% stearic acid (commercially available from Sigma-Aldrich, Croda), based on the total weight of the ground calcium carbonate.

(14) CC3: Ground calcium carbonate, commercially available from Omya International AG, Switzerland (d.sub.50:1.7 μm; d.sub.98:6 μm), surface-treated with 1.1 wt.-% polymethylhydrogen siloxane (Silres BS94, commercially available from Wacker Chemie AG, Germany), based on the total weight of the ground calcium carbonate.

(15) CC4: Ground calcium carbonate, commercially available from Omya International AG, Switzerland (d.sub.50:1.7 μm; d.sub.98:6 μm), surface-treated with 0.7 wt.-% succinic anhydride (Hydrores AS 1000, commercially available from Kemira Germany GmbH, Germany), based on the total weight of the ground calcium carbonate.

3. Examples

Example 1

Preparation of Masterbatches

(16) Masterbatches containing PBT or PET and one of the calcium carbonate fillers CC1 to CC4 were prepared on a lab scale Buss kneader (MKS 30 for PET and PR46 for PBT from Buss AG, Switzerland). The polymer PET was pre-dried prior processing in an oven at 160° C. for 4 hours. The compositions and filler contents of the prepared masterbatches are compiled in Table 1 below. The precise filler content was determined by the ash content.

(17) TABLE-US-00001 TABLE 1 Composition and filler content of prepared masterbatches. Masterbatch Polymer Filler Ash content [wt.-%] MB1 PBT CC1 49.9 MB2 PBT CC2 48.7 MB3 PBT CC3 48.7 MB4 PBT CC4 49.0 MB5 PET CC1 49.4 MB6 PET CC2 49.0 MB7 PET CC3 49.3 MB8 PET CC4 48.6

Example 2

Preparation of Multifilament Fibres

(18) Different amounts of the masterbatches produced according to Example 1 were mixed with further PBT or PET, wherein PET was pre-dried prior processing an oven at 160° C. for 4 hours. Multifilament fibres were produced from the obtained mixtures using a Collin Multifilament Lab Line CMF 100 (Dr. Collin GmbH, Germany), equipped with a single screw extruder with melt pump and spinneret diameter 50 mm with 34 filaments having a diameter of 0.3 mm. The spinning system was also equipped with a cooling chamber for quenching the multifilament fibre and stretching godets and a winder. Limanol 35F/1 (commercially available from Schill+Seilacher GmbH, Germany) was used as spinning oil. The machine conditions are given in Table 2 below. The compositions of the produced multifilament fibres are compiled in Table 3 below.

(19) The mechanical properties of the testing samples were determined using the elongation at maximum force test and tenacity test described above. The results of the mechanical tests are shown in Table 4 below.

(20) TABLE-US-00002 TABLE 2 Machine conditions for multifilament fibre spinning. Multifilament Multifilament Parameter fibres with PBT fibres with PET Extruder temperature 270-280° C. 300° C. Pump temperature 270° C. 300° C. Bypass temperature 270° C. 300° C. Adapter temperature 270° C. 300° C. Die temperature 270° C. 300° C. Godet Roll temperatures Roll1: 180° C. Roll 1: 130° C. Roll 2: 180° C. Roll 2: 130° C. Roll 3: 160° C. Roll 3: 100° C. Roll 4: 160° C. Roll 4: 100° C. Draw ratio 2, 3 or 4 2

(21) TABLE-US-00003 TABLE 3 Composition and draw ratio of produced multifilament fibres. Masterbatch filler Ash content Draw Sample Polymer Masterbatch content [wt.-%] [wt.-%] ratio 1 PBT — — — 2 2 PBT MB1 2 1.9 2 3 PBT MB1 5 2.6 2 4 PBT MB1 10 9.7 2 5 PBT MB2 2 1.4 2 6 PBT MB2 5 4.6 2 7 PBT MB2 10 10.8 2 8 PBT MB2 20 19.3 2 9 PBT MB2 30 28.9 2 10 PBT MB3 2 2.2 2 11 PBT MB3 5 4.9 2 12 PBT MB3 10 10.0 2 13 PBT MB3 20 19.4 2 14 PBT MB4 2 2.5 2 15 PBT MB4 5 4.0 2 16 PBT MB4 10 9.4 2 17 PBT MB4 20 20.4 2 18 PBT MB4 30 26.5 2 19 PET — — — 2 20 PET MB5 2 1.7 2 21 PET MB5 5 3.5 2 22 PET MB51 10 6.2 2 23 PET MB5 20 18.4 2 24 PET MB6 2 2.2 2 25 PET MB6 5 5.1 2 26 PET MB6 10 7.3 2 27 PET MB7 2 2.4 2 28 PET MB7 5 3.8 2 29 PET MB7 10 11.1 2 30 PET MB7 20 18.4 2 31 PET MB8 2 2.3 2 32 PET MB8 5 5.5 2 33 PET MB8 10 9.5 2 34 PET MB8 20 18.6 2 35 PET MB8 30 23.2 2 36 PBT — — — 4 37 PBT MB1 2 1.9 4 38 PBT MB1 4 2.8 3 39 PBT MB1 10 9.0 3

(22) TABLE-US-00004 TABLE 4 Mechanical properties and linear density of the produced multifilament fibres. Elongation at Maximum force maximum force Tenacity Linear density Sample [N] [%] [cN/dtex] [dtex] 1 8.29 118.6 0.81 1024 2 6.30 104.9 0.92 680 3 4.68 58.4 0.62 746 4 3.70 34.6 0.48 766 5 5.97 106.3 0.8 741 6 4.80 97.6 0.64 737 7 4.80 129.2 0.64 737 8 3.65 29.5 0.44 807 9 2.53 5.3 0.28 869 10 5.25 61.8 0.74 700 11 4.79 96.4 0.58 821 12 3.52 25.8 0.52 668 13 3.70 14.0 0.45 825 14 6.51 97.9 0.87 742 15 5.36 56.3 0.73 734 16 3.90 23.5 0.53 730 17 2.99 6.5 0.34 824 18 6.51 97.9 0.87 518 19 7.07 163.4 1.82 386 20 3.21 41.8 1.06 294 21 3.07 68.9 0.84 356 22 3.79 91.0 0.82 460 23 1.84 36.3 0.33 556 24 3.14 97.7 1.11 284 25 4.22 91.5 0.96 428 26 2.78 74.0 0.71 386 27 4.86 92.4 1.09 440 28 4.38 105.0 0.95 442 29 3.32 90.3 0.61 523 30 2.74 99.6 0.43 607 31 4.32 108.7 0.91 470 32 4.17 130.6 0.86 474 33 4.20 77.5 0.88 466 34 2.89 120.6 0.49 571 35 1.21 16.0 0.21 571 36 10.80 19.0 1.12 960 37 11.30 20.0 2.74 397 38 6.70 20.0 1.26 463 39 4.68 14.0 0.9 403

(23) The results shown in Table 4 reveal that polybutylene and polyethylene multifilament fibres comprising a calcium carbonate filler can be produced in good quality and mechanical properties with different filler amounts and draw ratio. Furthermore, it can be gathered from Table 4 that the calcium carbonate containing multifilament fibres show less elongation at maximum force and less tenacity, i.e. improved mechanical stiffness, compared to the multifilament fibres without calcium carbonate.