SYNTHETIC POLYMERIC FIBERS ADDITIVATED WITH LIGNIN, THEIR PROCESS OF OBTAINING AND USE FOR MANUFACTURING TEXTILE PRODUCTS

Abstract

Applied in the field of manufacturing textile products, the present invention provides compositions of synthetic polymeric fibers containing from 0.25% to 4.00% of lignin originated from the Kraft process, which are incorporated into the polymer through a subsequent extrusion process with the spinning process, by the use of a double-screw extruder coupled to a spinnerette. The obtained fibers are used in the production of textile products with anti-UV properties due to the presence of lignin, and with greater tenacity, resistance to bursting and antioxidant activity of the knit.

Claims

1. Synthetic polymeric fibers additivated with lignin comprising from 0.25% to 4.00% of lignin as an additive incorporated into thermoplastic polymeric materials.

2. Synthetic polymeric fibers additivated with lignin according to claim 1, wherein the thermoplastic polymeric materials are selected from the group consisting of polypropylene (PP), Poly (ethylene terephthalate) (PET), Polyethylene (PE), Poly (butylene terephthalate) (PBT), and Poly (lactic acid) (PLA).

3. Synthetic polymeric fibers additivated with lignin according to claim 1, wherein the lignin is obtained from eucalyptus, by the Kraft process.

4. Synthetic polymeric fibers additivated with lignin according to claim 1, containing 1.00% of lignin when produced from the polymers Polypropylene (PP), Polyethylene (PE), and/or Poly (butylene terephthalate) (PBT).

5. Synthetic polymeric fibers additivated with lignin according to claim 1, containing 0.50% of lignin when produced from the polymer Poly (ethylene terephthalate) (PET).

6. Synthetic polymeric fibers additivated with lignin according to claim 1, containing 2.00% of lignin when produced from the polymer Poly (lactic acid) (PLA).

7. Synthetic polymeric fibers additivated with lignin according to claim 1, presenting anti-UV protection.

8. Synthetic polymeric fibers additivated with lignin according to claim 1, presenting mechanical resistance to traction, tenacity and elongation of the threads.

9. Synthetic polymeric fibers additivated with lignin according to claim 1, presenting bursting resistance.

10. Synthetic polymeric fibers additivated with lignin according to claim 1, presenting antioxidant activity.

11. A process for obtaining synthetic polymeric fibers additivated with lignin being carried out in a single equipment that integrates a double-screw extruder and a spinnerette and is embodied through the following main steps: (A) thermoplastic extrusion with double-screw extruder; (B) generation of threads (spinning); and (C) stretching of threads.

12. The process for obtaining synthetic polymeric fibers additivated with lignin according to claim 11, promoting zones of gradual heating in step (1), according to temperature ranges varying between 50 and 300° C.

13. The process for obtaining synthetic polymeric fibers additivated with lignin according to claim 11, promoting the passage of the extruded product to the spinnerette coupled by means of an adapter using a pump interconnected to a clamp.

14. The process for obtaining synthetic polymeric fibers additivated with lignin according to claim 11, performing the spinning through the subsequent passage in matrixes, under a controlled temperature range located within the range from 150° C. to 300° C.

15. The process for obtaining synthetic polymeric fibers additivated with lignin according to claim 11, performing the stretching of synthetic fibers using heating rollers for continuous spinning (godets) with rotation levels gradually increasing.

16. A textile product comprising synthetic polymeric fibers additivated with lignin.

17. The textile product according to claim 16, wherein the textile product comprises an anti-UV fabrics with a sun protection factor (SPF) equal to or greater than 15.

18. The textile product according to claim 16, employed in the production of fabrics with mechanical resistance to traction, tenacity and elongation of the threads.

19. The textile product according to claim 16, wherein the textile product comprises a fabric having a resistance to bursting with a tenacity value equal to or greater than 13.9 (cN/tex).

20. The textile product according to claim 16, comprising a fabric having an antioxidant activity with oxidative induction time (OIT) equal to or greater than 6 minutes.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to aid the identification of the main characteristics of these compositions and process, the figures are presented, to which references are made as follows:

[0024] FIG. 1 shows the spinnerette attached to the extruder, with details for the flow of the additivated polymeric material. The double-screw extruder (1) is divided into five gradual heating zones (1A) (1B) (1C) (1D) (1E) and, by means of an adapter (2), the connection between the extruder and the spinnerette is made; the material leaving the extruder passes through a pump (3) which directs the flow to the clamp (4) and subsequently to the first spinning matrix (5A). The spinning process continues through the second matrix (5B) and finally ends up at the third matrix (5C).

[0025] FIG. 2 shows the spinnerette coupled to the extruder with details for the heating rollers for continuous spinning, usually called godets, at increasing intervals of rotation (6A) (6B) (6D) (6E), in order to promote stretching of the wires.

[0026] FIG. 3 shows a brief flowchart of the main steps in the processing of polymeric yarns, starting with: thermoplastic extrusion (A) of the polymeric material together with the lignin additive; wire generation (B) according to specific parameters; stretching on the spinnerette (C).

[0027] FIG. 4 shows the three types of fabrics that can be produced with the polymeric synthetic fibers object of this invention, characterizing their use for the production of “non-woven” structures (7A), flat fabrics (7B) and knits (7C).

DETAILED DESCRIPTION OF THE INVENTION

[0028] The present invention covers polymeric compositions, containing lignin from the Kraft process, from eucalyptus, according to the following contents in relation to the used polymeric materials:

TABLE-US-00001 Polymer Range Preferred Value Polypropylene (PP) 0.25%-4.00% 1.00% Poly(ethylene 0.25%-4.00% 0.50% terephthalate) (PET) Polyethylene (PE) 0.25%-4.00% 1.00% Poly(butylene 0.25%-4.00% 1.00% terephthalate) (PBT) Poly(lactic acid) 0.25%-4.00% 2.00% (PLA)

[0029] Polymeric material is considered to be any thermoplastic polymer with rheological characteristics that make it suitable for spinning, such as, for example, Polypropylene (PP), Polyethylene terephthalate (PET), Polyethylene (PE), Polybutylene terephthalate (PBT), Poly lactic acid (PLA), Polyamide (PA), but not limited to these.

[0030] PET and PP are the most used polymers in the spinning of synthetic textile fibers, PLA is an environmentally sustainable option, PE has high compatibility with lignin in terms of process temperature, as well as PP, and PBT has great chemical affinity with lignin, in addition to having consolidated use in specific applications in the textile industry.

[0031] The lignin used in this invention is isolated from eucalyptus biomass by means of the kraft process. It is noteworthy that although plant biomass is mainly composed of cellulose, hemicellulose and lignin, the processes to isolate lignin from lignocellulosic biomass generate structural alterations and splits in the lignin chain of origin. Thus, the isolated lignin does not have the same characteristics and effects in the application of lignin contained in biomass.

[0032] The use of lignin promoted technical benefits to such synthetic textile fibers, as well as implications related to the environmental advantages of being a product from a renewable and economical source.

[0033] The studies carried out showed improvements in the mechanical resistance to traction, tenacity and elongation of the threads, as well as an increase in the protection factor against ultraviolet rays and in the oxidative induction time (OIT), which improves the antioxidant activity. This improvement in the antioxidant activity results in the delay of the thermooxidative degradation of said fibers. Such protective effects are also verified in the knit produced by synthetic fibers, as well as the increase in resistance to bursting.

[0034] The results shown in the table below, obtained through fiber traction tests, demonstrated that the addition of lignin positively influences the mechanical properties of some of the aforementioned polymers, demonstrating an increase in tenacity related to the addition of lignin:

TABLE-US-00002 Addition of Tenacity Base polymer Lignin (cN/tex) Polypropylene .sup. 0% 13.8 (PP) 1.0% 14.3 Poly(ethylene .sup. 0% 12.07 terephthalate) 0.5% 15.32 (PET) Poly(butylene .sup. 0% 11.08 terephthalate) 2.0% 13.96 (PBT)

[0035] The developed production process is characterized by being a continuous process that promotes the incorporation of lignin into the polymeric material, through the extrusion process, carried out in a double-screw extruder coupled to a spinning matrix, so that the following steps are promoted in continuous flow: thermoplastic extrusion (A), generation of threads (B) and stretching (C).

[0036] The used spinnerette has 144 capillaries being the capillary length 0.3 mm and the capillary diameter 0.17 mm. The melt pressure can vary from 60-100 bar, while the pump rotation varies from 15 to 35 rpm.

[0037] The four stretching godets (rollers) have a gradual increase in rotation, the first being between 50 and 90 rpm, the second between 80 and 130 rpm, the third between 120 and 190 rpm and the fourth between 280 and 390 rpm.

[0038] Incorporation was carried out in the various polymers, balancing only the process parameters, mainly in drastic cases of thermo-mechanical requests for lignin, such as in the cases of PET and PBT. The ranges of the main temperature parameters used in the spinning and stretching of the aforementioned process are gathered in the table below:

TABLE-US-00003 Extrusion and spinning/stretching temperatures (° C.) Zone 1  50-170 Zone 2 170-250 Zone 3 170-250 Zone 4 170-270 Zone 5 170-270 Adaptor 200-280 Pump 200-280 Clamp 200-280 Matrix 1 150-300 Matrix 2 150-300 Matrix 3 150-300 Godets  50-120 Total stretching 2.5-7.5

[0039] It is important to emphasize the possibility of reusing fabrics after they are aged, through a recycling process, as lignin is already incorporated and, in this case, there is no need to go through the incorporation process again, configuring itself as an advantage both economic and environmental.

Example of the Invention: Polypropylene (PP)+Lignin

[0040] An example of incorporation of 1% lignin in Polypropylene (PP), carried out by means of the aforementioned continuous process of extrusion and spinning, will be discussed, in order to demonstrate the improvement of anti-UV effects according to the results obtained by the sun protection factor test.

[0041] The sun protection factor test was carried out in accordance with the Australian standard AS:NZS 4399:1996 and, for this test, RIB meshes were chosen, which are widely used in the production of collars and cuffs in the textile industry because they have a more aggregated interlacing.

[0042] The samples were produced using 2 cables according to the specification of pure fabric, composite or mixed:

AM1—Pure polypropylene (2 cables)
AM2—Mixed Mesh—pure PP (1 cable)/PP 1% lignin (1 cable)
AM3—Polypropylene with 1% lignin (2 cables)

[0043] The results were evaluated according to a classification basis based on the aforementioned Australian standard that categorizes UPF (Ultraviolet Protection Factor) values, wherein the samples AM2 and AM3 (containing lignin) showed an ultraviolet protection factor equal to or greater than 50, featuring an excellent protection against UV rays, according to the table below:

TABLE-US-00004 Reference Note Factor Category AM1 PP Pure  0 No Protection AM2 Mixed mesh 50 Excellent protection AM3 PP + 1%  50+ Excellent Lignin protection

[0044] In other words, it was found that the addition of 1% lignin through said process was an essential condition to obtaining the anti-UV effect in the spinning and consequent production of Polypropylene (PP) fabrics.

[0045] In addition, knit busting tests were performed, according to standard ISO13938-1:1999, in order to identify the effect of the addition of lignin on the mechanical properties of the textile artifact. The table below shows the results of bursting resistance, in MPa:

TABLE-US-00005 Bursting Reference Note Resistance (MPa) AMA PP Pure 1.26 AMB Mixed mesh 1.84 AMC PP + 1% Lignin 2.67

[0046] The obtained results showed that the breaking strength for the mesh produced exclusively with PP addivated with lignin (AMC) was 2.12 times greater than the sample of PP without additives. This equates to a 112% increase in bursting strength, while the AMB (Mixed Mesh) sample achieved a 46% increase in bursting strength.

[0047] Furthermore, Oxidative Induction Time (OIT) tests were performed to assess the level of thermal stability and oxidative resistance of the polymeric material in samples of approximately 5 mg inserted in aluminum crucibles.

[0048] The OIT test is performed using differential scanning calorimetry (DSC) in DSC Shimadzu equipment, model DSC-60, in order to predict the thermoxidative performance of a given material, that is, to assess the thermal stability in oxidant atmosphere of the material of interest.

[0049] Therefore, the OIT test consists of determining the time in which the material will undergo oxidation, at a given temperature, when subjected to an oxidant atmosphere (presence of O.sub.2).

[0050] The calculated OIT is the time measured between the moment of introduction of oxygen gas (O.sub.2) in the DSC oven and the Onset temperature, obtained from the exothermic oxidation peak. The table below exemplifies how the determination of the OIT of heat flux as a function of time is carried out.

TABLE-US-00006 Temper- Heating ature or cooling Range rate Used Gas Flow Sample Step (° C.) (° C./min) gas (ml/min) AM1 Heating 25-200 20 N.sub.2 50 AM2 Isotherm 200 5 mins N.sub.2 50 AM3 Isotherm 200 — O.sub.2 50

[0051] The following table presents the Oxidative Induction Time (OIT) results for samples AM1, AM2 and AM3, in minutes:

TABLE-US-00007 Reference Note OIT (min) AM1 PP Pure 0 AM2 Mixed mesh 6 AM3 PP + 1% Lignin 14

[0052] The obtained results showed that the oxidative induction time (OIT) for the mesh produced exclusively with PP additivated with lignin (AM3) was 14 minutes, while the PP sample without additives (AM1) had an OIT of 0 minutes and the sample AM2 (mixed mesh) had an OIT of 6 minutes. The OIT for the mesh produced exclusively with PP additivated with 1% lignin (AM3) was 2.33 times higher than the mixed mesh sample (AM2), which is equivalent to a 133% increase in the oxidative induction time (OIT).

Example of the Invention: Polyethylene Terephthalate (PET)+Lignin

[0053] An example of incorporation of 0.50% of lignin in Polyethylene terephthalate (PET), carried out by means of the aforementioned continuous process of extrusion and spinning, will be discussed, in order to demonstrate the improvement of the anti-UV effects according to results obtained by the sun protection factor test.

[0054] The sun protection factor test was carried out in accordance with the Australian standard AS:NZS 4399:1996 and, for this test, RIB meshes were chosen, which are widely used in the production of collars and cuffs in the textile industry because they have a more aggregated interlacing.

[0055] The samples were produced using 2 cables according to the specification of pure fabric, composite or mixed:

AN1—Pure polyethylene terephthalate (2 cables)
AN2—Mixed Mesh—Pure PET (1 cable)/PET 0.5% lignin (1 cable)
AN3—Polyethylene terephthalate with 0.5% lignin (2 cables)

[0056] The results were evaluated according to a classification basis based on the aforementioned Australian standard that categorizes UPF (Ultraviolet Protection Factor) values, wherein the samples AN2 and AN3 (containing lignin) showed an ultraviolet protection factor greater than 50, featuring an excellent protection against UV rays, according to the table below:

TABLE-US-00008 Reference Note Factor Category AN1 Pure PET 30  Very good protection AN2 Mixed mesh 50+ Excellent protection AN3 PET + 0.5% 50+ Excellent Lignin protection

[0057] In other words, it was found that the addition of 0.5% lignin through said process was an essential condition to obtain an increase in the anti-UV effect in the spinning and consequent production of Polyethylene terephthalate (PET) fabrics.

[0058] In addition, knit busting tests were performed, according to standard ISO13938-1:1999, in order to identify the effect of the addition of lignin on the mechanical properties of the textile artifact. The table below shows the results of bursting resistance, in MPa:

TABLE-US-00009 Bursting Reference Note Resistance (MPa) ANA Pure PET 1.02 ANB Mixed mesh 1.27 ANC PET + 0.5% 1.16 Lignin

[0059] The obtained results showed that the breaking resistance for the mesh produced exclusively with PET additivated with lignin (ANC) was 1.14 times greater than that of a PET sample without additives. This is equivalent to a 14% increase in bursting resistance, while in the ANB (Mixed Mesh) sample, a 25% increase in the bursting resistance was achieved.

[0060] Furthermore, Oxidative Induction Time (OIT) tests were performed to assess the level of thermal stability and oxidative resistance of the polymeric material in samples of approximately 5 mg inserted in aluminum crucibles.

[0061] The OIT test is performed using differential scanning calorimetry (DSC) in DSC Shimadzu equipment, model DSC-60, in order to predict the thermoxidative performance of a given material, that is, to assess the thermal stability in oxidant atmosphere of the material of interest.

[0062] Therefore, the OIT test consists of determining the time in which the material will undergo oxidation, at a given temperature, when subjected to an oxidant atmosphere (presence of O.sub.2).

[0063] The calculated OIT is the time measured between the moment of introduction of oxygen gas (O.sub.2) in the DSC oven and the Onset temperature, obtained from the exothermic oxidation peak. The table below exemplifies how the determination of the OIT of heat flux as a function of time is carried out.

TABLE-US-00010 Temper- Heating ature or cooling Range rate Used Gas Flow Sample Step (° C.) (° C./min) gas (ml/min) AN1 Heating 25-280 20 N.sub.2 50 AN2 Isotherm 280 5 mins N.sub.2 50 AN3 Isotherm 280 — O.sub.2 50

[0064] The following table presents the Oxidative Induction Time (OIT) results for samples AN1, AN2 and AN3, in minutes:

TABLE-US-00011 Reference Note OIT (min) AN1 Pure PET 0 AN2 Mixed mesh 9 AN3 PET + 0.5% 17 Lignin

[0065] The obtained results showed that the oxidative induction time (OIT) for the mesh produced exclusively with PET additivated with lignin (AN3) was 17 minutes, while the PET sample without additives (AN1) had an OIT of 0 minutes and the sample AN2 (mixed mesh) showed an OIT of 9 minutes. The OIT for the mesh produced exclusively with PET additivated with 0.5% lignin (AN3) was approximately 1.89 times higher than the mixed mesh sample (AN2), which is equivalent to an increase of almost 89% in the oxidative induction time (OIT).