COLORED SYNTHETIC FIBER
20230050671 · 2023-02-16
Inventors
Cpc classification
International classification
Abstract
The present invention relates to the field of polymers, in particular that of polyester fibers, and relates more specifically to a process for manufacturing a colored synthetic fiber, and to the uses thereof. More particularly, the present invention relates to a process for manufacturing a colored synthetic fiber from a semicrystalline thermoplastic polyester based on isosorbide, said fiber being colored by means of an aqueous solution of at least one disperse dye. The present invention also relates to a fiber colored by a disperse dye and also to the use thereof in the field of furnishings, textiles or sporting goods. The process according to the invention makes it possible to obtain colored synthetic fibers having improved quality and improved stability of the dyeing.
Claims
1. A process for manufacturing a colored synthetic fiber comprising the following steps of: 1) providing a semicrystalline thermoplastic polyester comprising at least one 1,4:3,6-dianhydrohexitol unit (A), at least one aliphatic diol unit (B) other than the 1,4:3,6-dianhydrohexitol units (A), and at least one aromatic dicarboxylic acid unit (C), wherein the (A)/[(A)+(B)] molar ratio is at least 0.05 and at most 0.30, the reduced viscosity in solution (35° C.; ortho-chlorophenol; 5 g/l of polyester) of which is greater than 50 ml/g; 2) preparing the synthetic fiber from said semicrystalline thermoplastic polyester; and 3) dyeing said synthetic fiber with an aqueous solution of at least one disperse dye.
2. The process according to claim 1, wherein the disperse dye is selected from azo-type dyes, anthraquinone-type disperse dyes, methine-type dyes, nitro-type dyes, naphthoquinone-type dyes, aminoketone-type dyes and mixtures thereof.
3. The process according to claim 2, wherein the disperse dye is an azo dye selected from the di-azo dyes or the mono-azo dyes derived from azobenzene.
4. The process according to claim 1, wherein the aqueous solution of disperse dye used for the dyeing step has a temperature of 120° C. to 140° C., preferably 130° C., and a pH of 3.5 to 5.5, preferably of 4 to 5.
5. The process according to claim 1, wherein the 1,4:3,6-dianhydrohexitol unit (A) is selected from isosorbide, isomannide, isoidide, or one of the mixtures thereof, preferably, the unit (A) is isosorbide.
6. The process according to claim 1, wherein the aliphatic diol unit (B) is 1,4-cyclohexanedimethanol.
7. The process according to claim 1, wherein the aromatic dicarboxylic acid unit (C) is terephthalic acid.
8. The process according to claim 1, wherein the semicrystalline thermoplastic polyester is free of non-cyclic aliphatic diol unit or comprises a molar amount of non-cyclic aliphatic diol units, with respect to the total number of monomer units of the polyester, of less than 1%; preferably, the polyester is free of non-cyclic aliphatic diol unit.
9. The process according to claim 1, wherein the preparation step of the synthetic fiber is carried out by the melt spinning method or by wet or dry solution processes.
10. A synthetic fiber colored by a disperse dye, said synthetic fiber consisting substantially of a semicrystalline thermoplastic polyester comprising at least one 1,4:3,6-dianhydrohexitol unit (A), at least one aliphatic diol unit (B) other than the 1,4:3,6-dianhydrohexitol units (A), at least one aromatic dicarboxylic acid (C), wherein the (A)/[(A)+(B)] molar ratio is at least 0.05 and at most 0.30, the reduced viscosity in solution (35° C.; ortho-chlorophenol; 5 g/l of polyester) of which is greater than 50 ml/g.
11. Use of the synthetic fiber as defined according to claim 10, in the field of furnishings, textiles or sporting goods.
Description
FIGURES
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EXAMPLES
[0090] Materials and Methods
[0091] A: Synthesis of the Polyesters
[0092] Different polyesters were prepared for the manufacture of the synthetic fibers.
[0093] Polymer A (PTIT): poly(trimethylene-co-isosorbide terephthalate).
[0094] Polymer A is a semicrystalline thermoplastic polyester according to the invention.
[0095] The synthesis of this polymer is carried out by melt route in 2 steps, via a transesterification and a polycondensation step. This synthesis takes place in a 60-l reactor equipped with a stirrer with torque measurement, a distillation column, a vacuum line and a nitrogen inlet.
[0096] First, the reactor is preheated to 100° C. before being loaded with the previously prepared reaction mixture.
[0097] The reaction mixture consists of: [0098] 18.7 kg of dimethyl terephthalate, [0099] 0.915 kg of isosorbide, [0100] 9.049 kg of 1,3-propanediol, [0101] 18.66 g of titanium butoxide, used as catalyst, [0102] 6.32 g of tetrahydroxyl ammonium, used as etherification inhibitor, [0103] 9.5 g of Hostanox PEPQ, used as antioxidant, [0104] 9.5 g of Irganox 1010, used as antioxidant.
[0105] The reactor is then inerted by 4 vacuum/nitrogen cycles.
[0106] The reaction medium is then heated to 220° C. for 1:30 h and then to 245° C. until the end of the trans-esterification reaction. This first step is carried out under 1.5 bar of nitrogen.
[0107] When the target transformation rate is reached, a decompression ramp is applied in order to obtain the maximum vacuum in 1:40 h and the temperature is increased to 255° C. after 80 minutes of vacuum ramp.
[0108] When the target torque is reached, the polymer is poured into a water bath and then granulated.
[0109] The polymer thus obtained has a reduced viscosity in solution (IV) of 73.7 ml/g.
[0110] The polymer pellets then undergo a post-condensation treatment in solid state in a 50-l glass flask heated by an oil bath, stirred and under nitrogen flow.
[0111] For the crystallization step, the oil bath is heated to 150° C. The flask is stirred and the granules are under nitrogen flow (flow rate=10 l/min). Crystallization is stopped after about 8 hours.
[0112] The pellets are then cooled under nitrogen to 40° C. to detach if necessary any pellets attached to the walls of the flask. Then, the oil bath is reheated to 210° C. while stirring and under nitrogen flow (10 l/min) for the post-condensation step. These conditions are maintained for 15 h.
[0113] The final polymer, denoted polymer A, has a final reduced viscosity in final solution IV of 102 ml/g, a molar ratio of isosorbide to diols of 5.2 mol %, a glass transition temperature Tg of 58° C., and a melting temperature Tm of 222° C.
[0114] Polymer B (PTIT) and Polymer C (PTT).
[0115] Polymer B is a semicrystalline thermoplastic polyester according to the invention while polymer C serves as comparison and does not contain isosorbide. These two polymers are obtained according to a process similar to that of polymer A and have the final properties mentioned in Table 1 hereunder.
TABLE-US-00001 TABLE 1 Amount of isosorbide Final IV Polymer reference (mol %) (ml/g) Tg (° C.) Tm (° C.) Polymer A PTI.sub.5T 5.2 102 59 221 Polymer B PTI.sub.10T 7.8 106 57 216 Polymer C PTT 0 99 56 228
[0116] Polymer D (PEIT): polyethylene-co-isosorbide terephthalate) (PEIT).
[0117] The synthesis of polymer D is carried out by melt route in 2 steps, via an esterification and a polycondensation step. This synthesis takes place in a 100-l reactor equipped with a stirrer with torque measurement, a distillation column, a vacuum line and a nitrogen inlet.
[0118] The reactor is first preheated to 100° C. before being loaded with the following reagents: [0119] 29 kg of terephthalic acid, [0120] 3.67 kg of isosorbide, [0121] 11.44 kg of ethylene glycol, [0122] 11.59 g of germanium oxide, used as catalyst, [0123] 2.65 g of cobalt acetate, [0124] 17.65 g of Hostanox, used as antioxidant, [0125] 17.65 g of Irganox 1010, used as antioxidant, [0126] 4.33 g of tetraethylammonium hydroxide, used as anti-DEG.
[0127] The reactor is then inerted by 4 vacuum/nitrogen cycles.
[0128] For the esterification step, the reaction medium is heated to 250° C. under 2.5 bar. The esterification is continued until a transformation rate of about 80% is obtained.
[0129] The pressure is then reduced in 15 minutes to atmospheric pressure (1024 hPa) in order to add phosphoric acid via an addition jar (3.53 g of phosphoric acid dissolved in 50 g of ethylene glycol).
[0130] A vacuum ramp is then applied to reach 3 mbar in 25 minutes. The temperature of the reactor is increased to 265° C. The polycondensation is monitored by a torque measurement.
[0131] When the target torque is reached the polymer is poured into a water tray and then granulated.
[0132] The polymer obtained has a reduced viscosity in solution (IV) of 54 ml/g.
[0133] The polymer pellets then undergo a post-condensation treatment in solid state in a 50-l glass flask heated by an oil bath, stirred and under nitrogen flow.
[0134] For the crystallization step, the oil bath is heated to 150° C. The flask is stirred and the granules are under nitrogen flow (flow rate=10 l/min). Crystallization is stopped after about 8 hours. The pellets are then cooled under nitrogen to 40° C. to remove any pellets attached to the walls of the flask. Then, the oil bath is reheated to 220° C. while stirring and under nitrogen flow (10 l/min) for the post-condensation step. These conditions are maintained for 90 h.
[0135] The final polymer denoted polymer D has a final reduced viscosity in solution (IV) of 106 ml/g, a ratio of isosorbide to diols of 11.9 mol %, a Tg of 91° C. and a Tm of 225° C.
[0136] Polymer E: (cyclohexanedimethylene-co-isosorbide terephthalate) (PITg)
[0137] The synthesis of polymer E was carried out according to example 3a of application WO2016/189239 A1. The polymer has the following properties: a molar ratio of isosorbide to diols of 15.2 mol %, a reduced viscosity in solution (IV) of 85 ml/g, a Tg of 109° C. and a Tm of 263° C.
[0138] Polymer F (PET):
[0139] Polymer F serves as a comparison and does not contain isosorbide. It is a commercial poly(ethylene terephthalate) from Invista.
[0140] B: Preparation of the Synthetic Fibers
[0141] Synthetic fibers A, B, D and E according to the invention were prepared by melt spinning on a pilot line from polymers A (PTIT), B (PTIT), D (PEIT), and E (PITg), respectively.
[0142] Comparative synthetic fibers C and F were also prepared from the isosorbide-free polymers C (PTT) and F (PET), respectively.
[0143] The extrusion temperature is 260° C. for polymers A (PTIT), B (PTIT) and C (PTT), and 300° C. for polymers D (PEIT), E (PITg) and F (PET).
[0144] The die used comprises a head with 48 holes having a diameter of 25 μm each, the material flow rate is of 2 kg/h, the drawing speed is 1200 m/min.
[0145] At the outlet of the die, cooling is done by air jet at room temperature (about 23° C.) then a sizing is applied to the surface of the fibers.
[0146] The fiber bundle is then passed over four pairs of buckets heated to different temperatures (between 30° C. and 115° C.) in order to adjust the mechanical properties, and the assembly is then wound.
[0147] The synthetic fibers obtained with each of the polyesters A to F are then soaked in dye baths.
[0148] C: Preparation of the Dye Baths
[0149] The disperse dyes used are marketed by Huntsman and listed hereunder: [0150] yellow: references Teratop GWL-01 (anthraquinone type) and Terasil W6GS (azo type) [0151] red: references Terasil 3BL-01 (azo type) and Terasil W4BS (azo type) [0152] blue: references Terasil 3RL-02 (anthraquinone type) and Terasil WBLS (azo type).
[0153] For each dye bath, three dyes are mixed with water, a dispersing agent (Univadine DIF, 1 g/L) and an anti-creasing agent (Albafluid CD, 1 g/L).
[0154] The mixture has a pH of 5 controlled by adding acetic acid in order to obtain the dye bath for each disperse dye.
[0155] Three dye baths are thus prepared by varying the amount of dye in order to obtain light, medium and dark colors. The amounts of each dye used are set out in Table 2 hereunder.
TABLE-US-00002 TABLE 2 Bath no. Dye used Amount of dye Light hue 1 Yellow 0.21% Teratop GWL-01 Red 0.036% Terasil 3BL-01 Blue 0.034% Terasil 3RL-02 Medium hue 2 Yellow 0.53% Teratop GWL-01 Red 0.1% Terasil 3BL-01 Blue 0.1% Terasil 3RL-02 Dark hue 3 Yellow 0.6% Terasil W6GS Red 0.65% Terasil W4BS Blue 0.3% Terasil WBLS
[0156] D: Dyeing of the Synthetic Fibers
[0157] The polyester synthetic fibers were colored with the light, medium and dark hues. For each of the dye baths, all the different fibers were put in the same bottle for dyeing.
[0158] The bottles are placed on an Ahiba Nuance top speed bottle-turner marketed by Datacolor.
[0159] The dyeing is carried out according to the time/temperature cycle having the following successive steps: [0160] inserting the fibers into the dyeing solution at room temperature (about 23° C.) then heating the whole to 60° C., [0161] holding at 60° C. for 10 min, then, [0162] increasing the temperature at a rate of 1.5° C./min up to 80° C., then, [0163] increasing the temperature at a rate of 1° C./min up to 130° C., then, [0164] holding at 130° C. for 45 min, and finally, [0165] reducing the temperature at a rate of 2.5° C./min to 60° C.
[0166] The various synthetic fibers are then recovered. Those dyed with baths 2 and 3 undergo an additional step of stripping in order to remove the excess disperse dye.
[0167] The stripping is carried out at 70° C. for 20 min in a bath comprising: [0168] 4 g/l of caustic soda, and [0169] 2 g/l of sodium hydrosulfite.
[0170] At the end of the 20 min, the synthetic fibers are hot and cold rinsed.
[0171] E: Test of Wash Fastness of the Dyes
[0172] Using the synthetic fibers E (PITg), three textiles are prepared and dyed with the light, medium and dark hue baths, respectively. The dyeing is carried out according to the previously disclosed protocol.
[0173] The same is done using the synthetic fibers F (PET).
[0174] For each of the textiles, the wash fastness is evaluated by means of a color fastness test carried out in accordance with standard ISO 105-006:2010.
[0175] The test comprises a step of washing the textiles at 40° C. for 30 min in 150 ml of detergent followed by a step of rinsing in two baths of water at 40° C.
[0176] Each textile is washed with a white strip of fabric made of 6 different materials, namely wool, acrylic, polyester, polyamide, cotton and acetate. This white strip of fabric serves as a control and thus makes it possible to check, where appropriate, whether the dye has bled out of the textile and to know onto what type(s) of material it has bled.
Results
[0177] The colored synthetic fibers obtained with the different baths are presented in
[0178] For the 3 hues tested, the synthetic fibers A, B, D, E obtained with the semicrystalline thermoplastic polyesters according to the invention absorb very rapidly a very large part of the dye. The coloring obtained is perfectly uniform and has a high-quality visual appearance.
[0179] Moreover, the dyeing kinetics are much faster with the synthetic fibers according to the invention than for comparative isosorbide-free synthetic fibers C and F in PTT and PET, respectively.
[0180] In order to confirm these results, color measurements were taken using a Konica Minolta spectrocolorimeter. The samples are placed on the cell and the measurement is taken in reflection mode.
[0181] The delta L corresponds to the difference in lightness (light or dark). The delta a corresponds to the difference in greenness-redness and finally, the delta b corresponds to the difference in blueness-yellowness.
[0182] The results of the color measurements are presented in Table 3 hereunder:
TABLE-US-00003 TABLE 3 Synthetic fiber Delta L Delta a Delta b Dark hue F (PET) D (PEI10T) −20.1 1.3 −4.75 C (PTT) A (PTI5T) −1.6 0.3 −0.85 B (PTI10T) −1.6 0.7 −1.25 Medium hue F (PET) D (PEI10T) −25.1 6.7 3.4 C (PTT) A (PTI5T) 0.6 1.65 1.2 B (PTI10T) −0.9 1 0.3 Light hue F (PET) D (PEI10T) −25.2 32 5.6 C (PTT) A (PTI5T) −0.6 1.3 1.5 B (PTI10T) 0.5 1.9 1.6
[0183] These results show that for synthetic fiber D (PEI10T), and regardless of the hue used, the dyeing kinetics are very fast. Moreover, the red pigment fixes much better than the other elements.
[0184] The results obtained on synthetic fibers A and B (PTIT) with respect to reference synthetic fiber C (PTT) show a slightly higher dye affinity, especially with the red and yellow pigments.
[0185] The dyeing behavior of synthetic fibers E (PITg) and F (PET) was compared on fabrics knitted from said fibers. The results are presented in
[0186] The knitted fabrics obtained with synthetic fibers E have a better dye affinity than those obtained with isosorbide-free synthetic fibers F.
[0187] Moreover, according to the test of wash fastness of the dyes, no bleeding was observed on the control strips, neither for the textile in synthetic fiber E or for the textile in synthetic fiber F.
[0188] This result shows that the synthetic fibers according to the invention thus have a wash fastness similar to that of the synthetic fibers commonly used and that the implementation of a thermoplastic polyester based on isosorbide does not alter this fastness.