Preparation method of PTT-PO3G linear multi-block copolymer, elastic fiber and preparation method thereof

Abstract

The present application belongs to the field of polymers and discloses a method for preparing a PTT-PO3G linear multi-block copolymer, comprising the following steps: Step 1: using terephthalic acid or terephthalate, 1,3-propylene glycol, and diamine as raw materials, and obtaining a prepolymer after esterification and acylation reaction; Step 2: adding polytrimethylene ether glycol to the reaction system of step 1, and performing polycondensation reaction to obtain a PTT-PO3G linear multi-block copolymer. The method adopts a two-step method, in which the PTT resin is synthesized in the first step, and the PO3G is segmented in the second step to obtain a PTT-PO3G linear multi-block copolymer. The copolymer has good fiber breaking strength, elongation at break, and elastic recovery rate. At the same time, the present invention also provides an elastic fiber and a preparation method thereof.

Description

Technical Field

[0001] The present invention relates to the field of polymers, and in particular to a preparation method of a PTT-PO3G linear multi-block copolymer, elastic fiber and a preparation method thereof. Background Art

[0002] Traditional spandex elastic fibers are mostly produced using solution spinning or dry spinning technology. During the preparation process, a large amount of toxic solvents are used, causing environmental pollution, which is contrary to the green development model advocated today. In addition, spandex elastic fibers have poor high temperature resistance and will produce large deformation under small stress.

[0003] Thermoplastic polyester elastomers have both the excellent elasticity of rubber and the processability of plastic. They can be used to prepare elastic fibers through melt spinning technology. The fibers have small deformation under large stress and excellent rebound performance and rebound fatigue resistance, which makes up for the shortcomings of traditional spandex elastic fibers.

[0004] CN109134850B discloses polyester amide, a preparation method thereof and fibers made from the polyester amide. Polyester amide is obtained by esterification and acylation reaction of diol, terephthalic acid and / or its derivatives, diamine and / or its derivatives.

[0005] CN103012761A discloses a method for preparing a copolyetherester elastomer, which comprises the following steps: mixing an aromatic dibasic acid, a polyether diol and a small molecule diol to carry out an esterification reaction, removing by-products tetrahydrofuran and water after the reaction is completed to obtain an esterified product; transferring the obtained esterified product to a pre-polycondensation reactor, adding an antioxidant and a catalyst, and reacting for 1-2 hours to obtain a prepolymer; transferring the prepolymer to a polycondensation reactor, polymerizing for 1.5-3 hours at a pressure of 100-200 Pa, and obtaining a copolyetherester elastomer after the reaction is completed.

[0006] The above scheme focuses more on optimizing the fiber breaking strength and elongation at break.

[0007] In actual production, for fibers with certain characteristic requirements, it is necessary to consider the coordinated improvement of the fiber's breaking strength, elongation at break, and elastic recovery rate.

[0008] The technical problem solved in this case is: how to improve the fiber breaking strength, elongation at break and elastic recovery rate of PTT resin. Summary of the Invention

[0009] The present invention aims to provide a method for preparing a PTT-PO3G linear multi-block copolymer. The method adopts a two-step process, wherein the first step is to synthesize a PTT resin, and the second step is to block PO3G to obtain a PTT-PO3G linear multi-block copolymer. The copolymer has good fiber breaking strength, elongation at break, and elastic recovery rate.

[0010] At the same time, the present invention also provides an elastic fiber and a preparation method thereof.

[0011] Unless otherwise specified in the present invention, nM represents nanomole / liter, μM represents micromole / liter, mM represents millimole / liter, and M represents mole / liter.

[0012] To achieve the above objectives, this application discloses:

[0013] A method for preparing a PTT-PO3G linear multi-block copolymer comprises the following steps:

[0014] Step 1: Using terephthalic acid or terephthalate, 1,3-propylene glycol, and diamine as raw materials, a prepolymer is obtained through esterification and acylation reactions;

[0015] Step 2: Add polytrimethylene ether glycol to the reaction system of step 1 to carry out polycondensation reaction to obtain a PTT-PO3G linear multi-block copolymer.

[0016] In the above preparation method, the molar ratio of terephthalic acid or terephthalate, 1,3-propylene glycol, and diamine is 4:7.2-7.996:0.004-0.8.

[0017] In the above preparation method, the weight of the polytrimethylene ether glycol is equivalent to 5 to 40 wt% of the total weight of terephthalic acid or terephthalate, 1,3-propylene glycol, diamine and polytrimethylene ether glycol.

[0018] In the above preparation method, the molecular weight of the polytrimethylene ether glycol is 1000 to 3000 g / mol.

[0019] In the above preparation method, the diamine is one or more of 1,6-hexanediamine, 1,10-decanediamine, and 1,12-diaminododecane;

[0020] The terephthalate ester is dimethyl terephthalate or diethyl terephthalate.

[0021] In the above preparation method, a catalyst is required to be added in both step 1 and step 2; the catalyst is one or more combinations of n-butyl titanate, isopropyl titanate, tetraethyl titanate, zinc acetate, magnesium acetate, manganese acetate, antimony trioxide, and antimony glycolate;

[0022] In step 2, a heat stabilizer is also required, and the heat stabilizer is one or more combinations of trimethyl phosphate, triphenyl phosphite, Irganox 1010, Irganox 168 and Irganox 245;

[0023] The molar ratio of the catalyst to terephthalic acid or terephthalate used in step 1 is 0.25-1.5:1000;

[0024] The molar ratio of the catalyst to terephthalic acid or terephthalate used in step 2 is 0.25-1.5:1000;

[0025] The molar ratio of the heat stabilizer to terephthalic acid or terephthalate used in step 2 is 0.25-1.5:1000.

[0026] In the above preparation method, the reaction pressure in step 1 is 1-2 bar, the reaction temperature is 190-240° C., and the reaction time is 1-2 h;

[0027] In step 2, the reaction is carried out at 190-240° C. for 1-2 hours, then to 250-260° C., while gradually reducing the pressure to below 100 Pa, and reacting for 2-5 hours.

[0028] At the same time, the present invention also discloses a method for preparing elastic fibers based on a PTT-PO3G linear multi-block copolymer, wherein the PTT-PO3G linear multi-block copolymer is prepared into slices and then dried and pre-crystallized in a drum oven at a pre-crystallization temperature of 100 to 120° C. for 6 to 10 hours. After drying, the slices have a moisture content of less than 70 ppm.

[0029] The elastic fiber can be obtained by melt spinning through a melt spinning machine.

[0030] In the above-mentioned method for preparing elastic fibers, the melt spinning method is as follows: dried and pre-crystallized chips are melt-extruded into a melt using a twin-screw extruder, enter the spinning assembly, are extruded from a spinneret, cooled by side blowing and a spinning tunnel, are oiled by an oiling roller, are wound at high speed on a winder to obtain spun fibers, are then heat-set by a first drafting hot roller and a second drafting hot roller, and are wound into filaments;

[0031] The heating temperature of the twin-screw extruder is 230-240°C, the temperature of the spinning assembly is 235-250°C, the winding speed of the spun fiber is 2000-3000 m / min, the drafting ratio is 2-4 times, the temperature of the drafting hot roller 1 is 70-80°C, and the temperature of the drafting hot roller 2 is 100-110°C.

[0032] Finally, the present invention also discloses an elastic fiber, which is prepared by the method described above.

[0033] This application has at least the following beneficial effects:

[0034] (1) The present invention introduces an amide group into the hard segment PTT molecular chain and performs segmentation through a two-step method, thereby enhancing the strength, resilience and resilience fatigue resistance of the modified PTT-PO3G elastic fiber, and the prepared elastic fiber has a soft feel and good hygroscopicity.

[0035] (2) The present invention prepares modified PTT-PO3G elastic fibers with excellent resilience through a melt spinning method, which can replace or partially replace spandex yarns, thereby reducing pollution in the spandex spinning process.

[0036] Specific embodiment

[0037] The present invention will be described clearly and completely below in conjunction with the examples of the present invention. In the description of the present invention, it should be noted that, where specific conditions are not specified in the examples, conventional conditions or conditions recommended by the manufacturer were used. Reagents or instruments used where the manufacturer is not specified are conventional products that can be purchased commercially.

[0038] Example 1

[0039] (1) Preparation of modified PTT-PO3G copolymer

[0040] (1.1) Terephthalic acid (4 mol, 664.5 g), PDO (7.84 mol, 596.6 g), 1,6-hexanediamine (0.16 mol, 18.6 g), and tetrabutyl titanate (4 mmol, 1.4 g) were added to a polymerization reactor. Nitrogen was introduced into the reactor to replace the air inside. The reactor was pressurized to 2 bar and heated to 230°C with a stirring speed of 100 r / min. The reaction was carried out for 1 h.

[0041] (1.2) After the reaction in step (1.1) is completed, the pressure is adjusted to normal pressure, and tetrabutyl titanate (4 mmol, 1.4 g), PO3G (5% of the total mass, molecular weight 2000 g / mol, 67.4 g), and trimethyl phosphate (4 mmol, 0.6 g) are added. The reaction is carried out at a temperature of 240°C and a stirring speed of 100 r / min for 2 h.

[0042] (1.3) After the reaction in step (1.2) is completed, reduce the pressure in the reactor to normal pressure. Slowly increase the temperature from 240°C to 260°C while slowly reducing the pressure to 30 Pa. Continue the reaction at 260°C for 3 hours.

[0043] The intrinsic viscosity of the prepared modified PTT-PO3G copolymer was 1.08 dL / g.

[0044] (2) Pretreatment

[0045] The prepared modified PTT-PO3G raw material was placed in a drum oven for drying, with a pre-crystallization temperature of 120° C. and a pre-crystallization time of 10 h. The water content after drying was less than 70 ppm.

[0046] (3) The pretreated modified PTT-PO3G is melt-spun, specifically, the melt is extruded by a twin-screw extruder, the melt enters the spinning assembly, the spinneret is extruded, the side blowing and the spinning tunnel are cooled, the oil is applied by an oiling roller, and the spun fiber is obtained by high-speed winding of a winder. The spun fiber is then stretched, heat-set, and wound into a filament to obtain the modified PTT-PO3G elastic fiber.

[0047] Among them, the process parameters of melt spinning include: the screw temperature of modified PTT-PO3G is 240°C, the temperature of the spinning assembly is 250°C, the pump supply of the metering pump is 40ml / min, the aperture of the spinneret is 0.25mm, the number of holes is 24, and the winding speed is 3000m / min; the stretching ratio is 2.0 times, the temperature of the stretching hot roller 1 is 80°C, and the temperature of the stretching hot roller 2 is 110°C.

[0048] Example 2

[0049] (1) Preparation of modified PTT-PO3G copolymer

[0050] (1.1) Dimethyl terephthalate (4 mol, 776.7 g), PDO (7.84 mol, 596.6 g), 1,10-decanediamine (0.16 mol, 27.6 g), and isopropyl titanate (4 mmol, 1.1 mg) were added to a polymerization reactor. Nitrogen was introduced into the reactor to replace the air inside. The reactor was pressurized to 2 bar and heated to 190°C with a stirring speed of 100 r / min for reaction for 1 h.

[0051] (1.2) After the reaction in step (1.1) is completed, the pressure is adjusted to normal pressure, and isopropyl titanate (4 mmol, 1.1 mg), PO3G (10% of the total mass, molecular weight 2000 g / mol, 155.7 g), and trimethyl phosphate (4 mmol, 0.6 g) are added. The reaction is carried out at a temperature of 220°C and a stirring speed of 100 r / min for 2 h.

[0052] (1.3) After the reaction in step (1.2) is completed, the pressure in the reactor is reduced to normal pressure, the temperature is slowly increased from 240°C to 260°C, and the pressure is slowly reduced to 30 Pa. The reaction is continued at 260°C for 3 hours.

[0053] The intrinsic viscosity of the prepared modified PTT-PO3G copolymer was 1.13 dL / g.

[0054] (2) Pretreatment

[0055] The prepared modified PTT-PO3G raw material was placed in a drum oven for drying. The pre-crystallization temperature was 110° C., the pre-crystallization time was 8 h, and the water content after drying was less than 70 ppm.

[0056] (3) The pretreated modified PTT-PO3G is melt-spun, specifically, the melt is extruded by a twin-screw extruder, the melt enters the spinning assembly, the spinneret is extruded, the side blowing and the spinning tunnel are cooled, the oil is applied by an oiling roller, and the spun fiber is obtained by high-speed winding of a winder. The spun fiber is then stretched, heat-set, and wound into a filament to obtain the modified PTT-PO3G elastic fiber.

[0057] Among them, the process parameters of melt spinning include: the screw temperature of modified PTT-PO3G is 240℃, the temperature of the spinning assembly is 250℃, the pump supply of the metering pump is 42ml / min, the aperture of the spinneret is 0.25mm, the number of holes is 24, and the winding speed is 2500m / min; the stretching ratio is 2.2 times, the temperature of the stretching hot roller 1 is 80℃, and the temperature of the stretching hot roller 2 is 110℃.

[0058] Example 3

[0059] (1) Preparation of modified PTT-PO3G copolymer

[0060] (1.1) Terephthalic acid (4 mol, 664.5 g), PDO (7.84 mol, 596.6 g), 1,12-diaminododecane (0.16 mol, 32.1 g), and isopropyl titanate (4 mmol, 1.1 g) were added to a polymerization reactor. Nitrogen was introduced into the reactor to replace the air inside. The reactor was pressurized to 2 bar and heated to 230°C with a stirring speed of 100 r / min. The reaction was continued for 1 h.

[0061] (1.2) After the reaction in step (1.1) is completed, the pressure is adjusted to normal pressure, and isopropyl titanate (4 mmol, 1.1 g), PO3G (15% of the total mass, molecular weight 2000 g / mol, 228.2 g), and trimethyl phosphate (4 mmol, 0.6 g) are added. The reaction is carried out at a temperature of 240°C and a stirring speed of 100 r / min for 2 h.

[0062] (1.3) After the reaction in step (1.2) is completed, the pressure in the reactor is reduced to normal pressure, the temperature is slowly increased from 240°C to 260°C, and the pressure is slowly reduced to 30 Pa. The reaction is continued at 260°C for 3 hours.

[0063] The intrinsic viscosity of the prepared modified PTT-PO3G copolymer was 1.24 dL / g.

[0064] (2) Pretreatment

[0065] The prepared modified PTT-PO3G raw material was placed in a drum oven for drying. The pre-crystallization temperature was 110° C., the pre-crystallization time was 8 h, and the water content after drying was less than 70 ppm.

[0066] (3) The pretreated modified PTT-PO3G is melt-spun, specifically, the melt is extruded by a twin-screw extruder, the melt enters the spinning assembly, the spinneret is extruded, the side blowing and the spinning tunnel are cooled, the oil is applied by an oiling roller, and the spun fiber is obtained by high-speed winding of a winder. The spun fiber is then stretched, heat-set, and wound into a filament to obtain the modified PTT-PO3G elastic fiber.

[0067] Among them, the process parameters of melt spinning include: the screw temperature of modified PTT-PO3G is 235°C, the temperature of the spinning assembly is 240°C, the pump supply of the metering pump is 45ml / min, the aperture of the spinneret is 0.25mm, the number of holes is 24, and the winding speed is 2500m / min; the stretching ratio is 2.5 times, the temperature of the stretching hot roller 1 is 80°C, and the temperature of the stretching hot roller 2 is 110°C.

[0068] Example 4

[0069] (1) Preparation of modified PTT-PO3G copolymer

[0070] (1) Dimethyl terephthalate (4 mol, 776.7 g), PDO (7.84 mol, 596.6 g), 1,6-hexanediamine (0.16 mol, 18.6 g) and antimony trioxide (4 mmol, 1.2 g) were added to a polymerization kettle. Nitrogen was introduced into the kettle to replace the air in the kettle, and the pressure was increased to 2 bar. The temperature was raised to 190°C with a stirring speed of 100 r / min and the reaction was carried out for 1 h.

[0071] (1.2) After the reaction in step (1.1) is completed, the pressure is adjusted to normal pressure, and antimony trioxide (4 mmol, 1.2 mg), PO3G (20% of the total mass, molecular weight 2000 g / mol, 348.0 g), and trimethyl phosphate (4 mmol, 0.6 g) are added. The reaction is carried out at a temperature of 220°C and a stirring speed of 100 r / min for 2 h.

[0072] (1.3) After the reaction in step (1.2) is completed, reduce the pressure in the reactor to normal pressure. Slowly increase the temperature from 240°C to 260°C while slowly reducing the pressure to 30 Pa. Continue the reaction at 260°C for 3 hours.

[0073] The intrinsic viscosity of the prepared modified PTT-PO3G copolymer was 1.30 dL / g.

[0074] (2) Pretreatment

[0075] The prepared modified PTT-PO3G raw material was placed in a drum oven for drying, the pre-crystallization temperature was 100° C., the pre-crystallization time was 6 h, and the water content after drying was less than 70 ppm.

[0076] (3) The pretreated modified PTT-PO3G is melt-spun, specifically, the melt is extruded by a twin-screw extruder, the melt enters the spinning assembly, the spinneret is extruded, the side blowing and the spinning tunnel are cooled, the oil is applied by an oiling roller, and the spun fiber is obtained by high-speed winding of a winder. The spun fiber is then stretched, heat-set, and wound into a filament to obtain the modified PTT-PO3G elastic fiber.

[0077] Among them, the process parameters of melt spinning include: the screw temperature of modified PTT-PO3G is 235°C, the temperature of the spinning assembly is 240°C, the pump supply of the metering pump is 45ml / min, the aperture of the spinneret is 0.25mm, the number of holes is 24, and the winding speed is 2000m / min; the stretching ratio is 2.4 times, the temperature of the stretching hot roller 1 is 70°C, and the temperature of the stretching hot roller 2 is 100°C.

[0078] Example 5

[0079] (1) Preparation of modified PTT-PO3G copolymer

[0080] (1.1) Terephthalic acid (4 mol, 664.5 g), PDO (7.84 mol, 596.6 g), 1,6-hexanediamine (0.16 mol, 18.6 g), and tetrabutyl titanate (1 mmol, 0.3 g) were added to a polymerization reactor. Nitrogen was introduced into the reactor to replace the air inside, and the reactor was pressurized to 2 bar. The temperature was raised to 230°C while stirring at 100 r / min and the reaction was carried out for 1 h.

[0081] (1.2) After the reaction in step (1.1) is completed, the pressure is adjusted to normal pressure, and tetrabutyl titanate (1 mmol, 0.3 g), PO3G (30% of the total mass, molecular weight 2000 g / mol, 548.4 g), and trimethyl phosphate (1 mmol, 0.2 g) are added. The reaction is carried out at a temperature of 240°C and a stirring speed of 100 r / min for 2 h.

[0082] (1.3) After the reaction in step (1.2) is completed, the pressure in the reactor is reduced to normal pressure, the temperature is slowly increased from 240°C to 260°C, and the pressure is slowly reduced to 30 Pa. The reaction is continued at 260°C for 3 hours.

[0083] The intrinsic viscosity of the prepared modified PTT-PO3G copolymer was 1.35 dL / g.

[0084] (2) Pretreatment

[0085] The prepared modified PTT-PO3G raw material was placed in a drum oven for drying, the pre-crystallization temperature was 100° C., the pre-crystallization time was 6 h, and the water content after drying was less than 70 ppm.

[0086] (3) The pretreated modified PTT-PO3G is melt-spun, specifically, the melt is extruded by a twin-screw extruder, the melt enters the spinning assembly, the spinneret is extruded, the side blowing and the spinning tunnel are cooled, the oil is applied by an oiling roller, and the spun fiber is obtained by high-speed winding of a winder. The spun fiber is then stretched, heat-set, and wound into a filament to obtain the modified PTT-PO3G elastic fiber.

[0087] Among them, the process parameters of melt spinning include: the screw temperature of modified PTT-PO3G is 235°C, the temperature of the spinning assembly is 240°C, the pump supply of the metering pump is 50ml / min, the aperture of the spinneret is 0.25mm, the number of holes is 24, and the winding speed is 2000m / min; the drawing ratio is 3.0 times, the temperature of the drawing hot roller 1 is 70°C, and the temperature of the drawing hot roller 2 is 100°C.

[0088] Example 6

[0089] (1) Preparation of modified PTT-PO3G copolymer

[0090] (1.1) Terephthalic acid (4 mol, 664.5 g), PDO (7.84 mol, 596.6 g), 1,10-decanediamine (0.16 mol, 27.6 g), and tetrabutyl titanate (4 mmol, 1.4 g) were added to a polymerization reactor. Nitrogen was introduced into the reactor to replace the air in the reactor. The reactor was pressurized to 2 bar and heated to 230°C with a stirring speed of 100 r / min for reaction for 1 h.

[0091] (1.2) After the reaction in step (1.1) is completed, the pressure is adjusted to normal pressure, and tetrabutyl titanate (4 mmol, 1.4 g), PO3G (40% of the total mass, molecular weight 2000 g / mol, 859.1 g), and trimethyl phosphate (4 mmol, 0.6 g) are added. The reaction is carried out at a temperature of 240°C and a stirring speed of 100 r / min for 2 h.

[0092] (1.3) After the reaction in step (1.2) is completed, reduce the pressure in the reactor to normal pressure. Slowly increase the temperature from 240°C to 260°C while slowly reducing the pressure to 30 Pa. Continue the reaction at 260°C for 3 hours.

[0093] The intrinsic viscosity of the prepared modified PTT-PO3G copolymer was 1.42 dL / g.

[0094] (2) Pretreatment

[0095] The prepared modified PTT-PO3G raw material was placed in a drum oven for drying, the pre-crystallization temperature was 100° C., the pre-crystallization time was 6 h, and the water content after drying was less than 70 ppm.

[0096] (3) The pretreated modified PTT-PO3G is melt-spun, specifically, the melt is extruded by a twin-screw extruder, the melt enters the spinning assembly, the spinneret is extruded, the side blowing and the spinning tunnel are cooled, the oil is applied by an oiling roller, and the spun fiber is obtained by high-speed winding of a winder. The spun fiber is then stretched, heat-set, and wound into a filament to obtain the modified PTT-PO3G elastic fiber.

[0097] Among them, the process parameters of melt spinning include: the screw temperature of modified PTT-PO3G is 230℃, the temperature of the spinning assembly is 240℃, the pump supply of the metering pump is 60ml / min, the aperture of the spinneret is 0.25mm, the number of holes is 24, and the winding speed is 2000m / min; the stretching ratio is 3.5 times, the temperature of the stretching hot roller 1 is 70℃, and the temperature of the stretching hot roller 2 is 100℃.

[0098] Example 7

[0099] (1) Preparation of modified PTT-PO3G copolymer

[0100] (1.1) Terephthalic acid (4 mol, 664.5 g), PDO (7.84 mol, 596.6 g), 1,12-diaminododecane (0.16 mol, 32.1 g), and tetrabutyl titanate (6 mmol, 2.0 g) were added to a polymerization reactor. Nitrogen was introduced into the reactor to replace the air in the reactor. The reactor was pressurized to 2 bar and heated to 230°C with a stirring speed of 100 r / min for reaction for 1 h.

[0101] (1.2) After the reaction in step (1.1) is completed, the pressure is adjusted to normal pressure, and tetrabutyl titanate (6 mmol, 2.0 g), PO3G (10% of the total mass, molecular weight 1000 g / mol, 143.7 g), and trimethyl phosphate (6 mmol, 0.8 g) are added. The reaction is carried out at a temperature of 240°C and a stirring speed of 100 r / min for 2 h.

[0102] (1.3) After the reaction in step (1.2) is completed, reduce the pressure in the reactor to normal pressure. Slowly increase the temperature from 240°C to 260°C while slowly reducing the pressure to 30 Pa. Continue the reaction at 260°C for 3 hours.

[0103] The intrinsic viscosity of the prepared modified PTT-PO3G copolymer was 1.09 dL / g.

[0104] (2) Pretreatment

[0105] The prepared modified PTT-PO3G raw material was placed in a drum oven for drying. The pre-crystallization temperature was 110° C., the pre-crystallization time was 8 h, and the water content after drying was less than 70 ppm.

[0106] (3) The pretreated modified PTT-PO3G is melt-spun, specifically, the melt is extruded by a twin-screw extruder, the melt enters the spinning assembly, the spinneret is extruded, the side blowing and the spinning tunnel are cooled, the oil is applied by an oiling roller, and the spun fiber is obtained by high-speed winding of a winder. The spun fiber is then stretched, heat-set, and wound into a filament to obtain the modified PTT-PO3G elastic fiber.

[0107] Among them, the process parameters of melt spinning include: the screw temperature of modified PTT-PO3G is 240℃, the temperature of the spinning assembly is 250℃, the pump supply of the metering pump is 40ml / min, the aperture of the spinneret is 0.25mm, the number of holes is 24, and the winding speed is 2500m / min; the stretching ratio is 2.3 times, the temperature of the stretching hot roller 1 is 80℃, and the temperature of the stretching hot roller 2 is 110℃.

[0108] Example 8

[0109] (1) Preparation of modified PTT-PO3G copolymer

[0110] (1.1) Terephthalic acid (4 mol, 664.5 g), PDO (7.84 mol, 596.6 g), 1,6-hexanediamine (0.16 mol, 18.6 g), and tetrabutyl titanate (4 mmol, 1.4 mg) were added to a polymerization reactor. Nitrogen was introduced into the reactor to replace the air inside. The reactor was pressurized to 2 bar and heated to 230°C with a stirring speed of 100 r / min. The reaction was carried out for 1 h.

[0111] (1.2) After the reaction in step (1.1) is completed, the pressure is adjusted to normal pressure, and tetrabutyl titanate (2 mmol, 0.7 g), zinc acetate (2 mmol, 0.4 g), PO3G (20% of the total mass, molecular weight 1000 g / mol, 320.0 g), and trimethyl phosphate (4 mmol, 0.6 g) are added. The reaction is carried out at a temperature of 240°C and a stirring speed of 100 r / min for 2 h.

[0112] (1.3) After the reaction in step (1.2) is completed, the pressure in the reactor is reduced to normal pressure, the temperature is slowly increased from 240°C to 260°C, and the pressure is slowly reduced to 30 Pa. The reaction is continued at 260°C for 3 hours.

[0113] The intrinsic viscosity of the prepared modified PTT-PO3G copolymer was 1.21 dL / g.

[0114] (2) Pretreatment

[0115] The prepared modified PTT-PO3G raw material was placed in a drum oven for drying. The pre-crystallization temperature was 110° C., the pre-crystallization time was 8 h, and the water content after drying was less than 70 ppm.

[0116] (3) The pretreated modified PTT-PO3G is melt-spun, specifically, the melt is extruded by a twin-screw extruder, the melt enters the spinning assembly, the spinneret is extruded, the side blowing and the spinning tunnel are cooled, the oil is applied by an oiling roller, and the spun fiber is obtained by high-speed winding of a winder. The spun fiber is then stretched, heat-set, and wound into a filament to obtain the modified PTT-PO3G elastic fiber.

[0117] Among them, the process parameters of melt spinning include: the screw temperature of modified PTT-PO3G is 235°C, the temperature of the spinning assembly is 240°C, the pump supply of the metering pump is 45ml / min, the aperture of the spinneret is 0.25mm, the number of holes is 24, and the winding speed is 2000m / min; the stretching ratio is 2.5 times, the temperature of the stretching hot roller 1 is 70°C, and the temperature of the stretching hot roller 2 is 100°C.

[0118] Example 9

[0119] (1) Preparation of modified PTT-PO3G copolymer

[0120] (1.1) Terephthalic acid (4 mol, 664.5 g), PDO (7.84 mol, 596.6 g), 1,6-hexanediamine (0.16 mol, 18.6 g), and isopropyl titanate (4 mmol, 1.1 g) were added to a polymerization reactor. Nitrogen was introduced into the reactor to replace the air inside. The reactor was pressurized to 2 bar and heated to 230°C with a stirring speed of 100 r / min. The reaction was carried out for 1 h.

[0121] (1.2) After the reaction in step (1.1) is completed, the pressure is adjusted to normal pressure, and isopropyl titanate (4 mmol, 1.1 g), PO3G (5% of the total mass, molecular weight 2700 g / mol, 67.4 g), and trimethyl phosphate (4 mmol, 0.6 g) are added. The reaction is carried out at a temperature of 240°C and a stirring speed of 100 r / min for 2 h.

[0122] (1.3) After the reaction in step (1.2) is completed, reduce the pressure in the reactor to normal pressure. Slowly increase the temperature from 240°C to 260°C while slowly reducing the pressure to 30 Pa. Continue the reaction at 260°C for 3 hours.

[0123] The intrinsic viscosity of the prepared modified PTT-PO3G copolymer was 1.10 dL / g.

[0124] (2) Pretreatment

[0125] The prepared modified PTT-PO3G raw material was placed in a drum oven for drying, with a pre-crystallization temperature of 120° C. and a pre-crystallization time of 10 h. The water content after drying was less than 70 ppm.

[0126] (3) The pretreated modified PTT-PO3G is melt-spun, specifically, the melt is extruded by a twin-screw extruder, the melt enters the spinning assembly, the spinneret is extruded, the side blowing and the spinning tunnel are cooled, the oil is applied by an oiling roller, and the spun fiber is obtained by high-speed winding of a winder. The spun fiber is then stretched, heat-set, and wound into a filament to obtain the modified PTT-PO3G elastic fiber.

[0127] Among them, the process parameters of melt spinning include: the screw temperature of modified PTT-PO3G is 240°C, the temperature of the spinning assembly is 245°C, the pump supply of the metering pump is 43ml / min, the aperture of the spinneret is 0.25mm, the number of holes is 24, and the winding speed is 2500m / min; the stretching ratio is 2.0 times, the temperature of the stretching hot roller 1 is 80°C, and the temperature of the stretching hot roller 2 is 110°C.

[0128] The modified PTT-PO3G elastic fiber produced by melt spinning has a breaking strength of 2.6 cN / dtex, an elongation at break of 35%, and an elastic recovery rate of 92% at an elongation of 10%.

[0129] Example 10

[0130] (1) Preparation of modified PTT-PO3G copolymer

[0131] (1.1) Terephthalic acid (4 mol, 664.5 g), PDO (7.68 mol, 584.5 g), 1,6-hexanediamine (0.32 mol, 37.2 g), and tetrabutyl titanate (4 mmol, 1.4 mg) were added to a polymerization reactor. Nitrogen was introduced into the reactor to replace the air inside. The reactor was pressurized to 2 bar and heated to 230°C with a stirring speed of 100 r / min. The reaction was carried out for 1 h.

[0132] (1.2) After the reaction in step (1.1) is completed, the pressure is adjusted to normal pressure, and tetrabutyl titanate (2 mmol, 0.7 g), zinc acetate (2 mmol, 0.4 g), PO3G (10% of the total mass, molecular weight 2000 g / mol, 143.0 g), and trimethyl phosphate (4 mmol, 0.6 g) are added. The reaction is carried out at a temperature of 240°C and a stirring speed of 100 r / min for 2 h.

[0133] (1.3) After the reaction in step (1.2) is completed, the pressure in the reactor is reduced to normal pressure, the temperature is slowly increased from 240°C to 260°C, and the pressure is slowly reduced to 30 Pa. The reaction is continued at 260°C for 3 hours.

[0134] The intrinsic viscosity of the prepared modified PTT-PO3G copolymer was 0.89 dL / g.

[0135] (2) Pretreatment

[0136] The prepared modified PTT-PO3G raw material was placed in a drum oven for drying. The pre-crystallization temperature was 110° C., the pre-crystallization time was 8 h, and the water content after drying was less than 70 ppm.

[0137] (3) The pretreated modified PTT-PO3G is melt-spun, specifically, the melt is extruded by a twin-screw extruder, the melt enters the spinning assembly, the spinneret is extruded, the side blowing and the spinning tunnel are cooled, the oil is applied by an oiling roller, and the spun fiber is obtained by high-speed winding of a winder. The spun fiber is then stretched, heat-set, and wound into a filament to obtain the modified PTT-PO3G elastic fiber.

[0138] Among them, the process parameters of melt spinning include: the screw temperature of modified PTT-PO3G is 235°C, the temperature of the spinning assembly is 240°C, the pump supply of the metering pump is 42ml / min, the aperture of the spinneret is 0.25mm, the number of holes is 24, and the winding speed is 2000m / min; the stretching ratio is 2 times, the temperature of the stretching hot roller 1 is 70°C, and the temperature of the stretching hot roller 2 is 100°C.

[0139] Example 11

[0140] (1) Preparation of modified PTT-PO3G copolymer

[0141] (1.1) Terephthalic acid (4 mol, 664.5 g), PDO (7.92 mol, 602.7 g), 1,6-hexanediamine (0.08 mol, 9.3 g), and tetrabutyl titanate (4 mmol, 1.4 mg) were added to a polymerization reactor. Nitrogen was introduced into the reactor to replace the air inside, and the reactor was pressurized to 2 bar. The temperature was raised to 230°C while stirring at 100 r / min and the reaction was carried out for 1 h.

[0142] (1.2) After the reaction in step (1.1) is completed, the pressure is adjusted to normal pressure, and tetrabutyl titanate (2 mmol, 0.7 g), zinc acetate (2 mmol, 0.4 g), PO3G (10% of the total mass, molecular weight 2000 g / mol, 141.8 g), and trimethyl phosphate (4 mmol, 0.6 g) are added. The reaction is carried out at a temperature of 240°C and a stirring speed of 100 r / min for 2 h.

[0143] (1.3) After the reaction in step (1.2) is completed, the pressure in the reactor is reduced to normal pressure, the temperature is slowly increased from 240°C to 260°C, and the pressure is slowly reduced to 30 Pa. The reaction is continued at 260°C for 3 hours.

[0144] The intrinsic viscosity of the prepared modified PTT-PO3G copolymer was 0.90 dL / g.

[0145] (2) Pretreatment

[0146] The prepared modified PTT-PO3G raw material was placed in a drum oven for drying, with a pre-crystallization temperature of 120° C. and a pre-crystallization time of 10 h. The water content after drying was less than 70 ppm.

[0147] (3) The pretreated modified PTT-PO3G is melt-spun, specifically, the melt is extruded by a twin-screw extruder, the melt enters the spinning assembly, the spinneret is extruded, the side blowing and the spinning tunnel are cooled, the oil is applied by an oiling roller, and the spun fiber is obtained by high-speed winding of a winder. The spun fiber is then stretched, heat-set, and wound into a filament to obtain the modified PTT-PO3G elastic fiber.

[0148] Among them, the process parameters of melt spinning include: the screw temperature of modified PTT-PO3G is 240℃, the temperature of the spinning assembly is 250℃, the pump supply of the metering pump is 40ml / min, the aperture of the spinneret is 0.25mm, the number of holes is 24, and the winding speed is 2500m / min; the stretching ratio is 2 times, the temperature of the stretching hot roller 1 is 80℃, and the temperature of the stretching hot roller 2 is 110℃.

[0149] Comparative Example 1

[0150] (1) Preparation of PTT-PO3G copolymer

[0151] (1.1) Terephthalic acid (4 mol, 664.5 g), PDO (8 mol, 608.8 g), and tetrabutyl titanate (4 mmol, 1.4 g) were added to a polymerization reactor. Nitrogen was introduced into the reactor to replace the air inside. The reactor was pressurized to 2 bar and heated to 230°C with a stirring speed of 100 r / min. The reaction was continued for 1 h.

[0152] (1.2) After the reaction in step (1.1) is completed, the pressure is adjusted to normal pressure, and tetrabutyl titanate (4 mmol, 1.4 g), PO3G (5% of the total mass, molecular weight 2000 g / mol, 67.0 g), and trimethyl phosphate (4 mmol, 0.6 g) are added and reacted at a temperature of 240°C and a stirring speed of 100 r / min for 2 h.

[0153] (1.3) After the reaction in step (1.2) is completed, the pressure in the reactor is reduced to normal pressure, and the temperature is slowly increased from 240°C to 260°C while the pressure is slowly reduced to 30 Pa.

[0154] The intrinsic viscosity of the prepared PTT-PO3G copolymer was 0.92 dL / g.

[0155] (2) Pretreatment

[0156] The prepared PTT-PO3G raw material was placed in a drum oven for drying. The pre-crystallization temperature was 120° C., the pre-crystallization time was 10 h, and the water content after drying was less than 70 ppm.

[0157] (3) The pretreated PTT-PO3G is melt-spun, specifically, the melt is extruded by a twin-screw extruder, the melt enters the spinning assembly, the spinneret is extruded, the side blowing and the spinning tunnel are cooled, the oil is applied by an oiling roller, and the spun fiber is obtained by a high-speed winding machine. The spun fiber is then stretched, heat-set, and wound into a filament to obtain the PTT-PO3G elastic fiber.

[0158] Among them, the process parameters of melt spinning include: the screw temperature of PTT-PO3G is 240℃, the temperature of the spinning assembly is 250℃, the pump supply of the metering pump is 40ml / min, the aperture of the spinneret is 0.25mm, the number of holes is 24, and the winding speed is 3000m / min; the stretching ratio is 2.0 times, the temperature of the stretching hot roller 1 is 80℃, and the temperature of the stretching hot roller 2 is 110℃.

[0159] The PTT-PO3G elastic fiber produced by melt spinning has a breaking strength of 1.8 cN / dtex, an elongation at break of 28%, and an elastic recovery rate of 82% at an elongation of 10%.

[0160] Comparative Example 2

[0161] (1) Preparation of PTT-PO3G copolymer

[0162] (1.1) Terephthalic acid (4 mol, 664.5 g), PDO (7.84 mol, 596.6 g), 1,6-hexanediamine (0.16 mol, 18.6 g), tetrabutyl titanate (4 mmol, 1.4 g), PO3G (5% of the total mass, molecular weight 2000 g / mol, 67.0 g), and trimethyl phosphate (4 mmol, 0.6 g) were added to a polymerization reactor. Nitrogen was introduced into the reactor to replace the air in the reactor, and the reactor was pressurized to 2 bar. The temperature was raised to 230°C with a stirring speed of 100 r / min and the reaction was carried out for 3 h.

[0163] (1.2) After the reaction in step (1.2) is completed, the pressure in the reactor is reduced to normal pressure, and the temperature is slowly increased from 240°C to 260°C while the pressure is slowly reduced to 30 Pa.

[0164] The intrinsic viscosity of the prepared PTT-PO3G copolymer was 0.88 dL / g.

[0165] (2) Pretreatment

[0166] The prepared PTT-PO3G raw material was placed in a drum oven for drying. The pre-crystallization temperature was 120° C., the pre-crystallization time was 10 h, and the water content after drying was less than 70 ppm.

[0167] (3) The pretreated PTT-PO3G is melt-spun, specifically, the melt is extruded by a twin-screw extruder, the melt enters the spinning assembly, the spinneret is extruded, the side blowing and the spinning tunnel are cooled, the oil is applied by an oiling roller, and the spun fiber is obtained by a high-speed winding machine. The spun fiber is then stretched, heat-set, and wound into a filament to obtain the PTT-PO3G elastic fiber.

[0168] Among them, the process parameters of melt spinning include: the screw temperature of PTT-PO3G is 240℃, the temperature of the spinning assembly is 250℃, the pump supply of the metering pump is 40ml / min, the aperture of the spinneret is 0.25mm, the number of holes is 24, and the winding speed is 3000m / min; the stretching ratio is 2.0 times, the temperature of the stretching hot roller 1 is 80℃, and the temperature of the stretching hot roller 2 is 110℃.

[0169] Performance Testing

[0170] Breaking strength and elongation at break: The tensile properties of the fibers were tested using an XL-1A yarn strength and elongation tester with a clamping distance of 250 mm and a tensile rate of 1000 mm / min.

[0171] Elastic recovery rate: The fiber resilience was tested using an LLY-06E electronic fiber strength tester with a clamping distance of 20 mm, a stretching and recovery rate of 20 mm / min, and a fixed elongation of 10%.

[0172] The test results can be found in Table 1

[0173] Table 1 Test results

[0174]

[0175]

[0176] Result analysis:

[0177] 1. With the increase of the mass fraction of PO3G polyether soft segment, the elastic recovery rate of PTT-PO3G elastic fiber gradually increases. This is attributed to the higher entropy elasticity of the soft segment. The increase of its content is conducive to reducing the plastic deformation of the fiber and increasing the elastic recovery rate.

[0178] 2. The introduction of a small amount of amide units and hydrogen bonding forces between molecular chains in PTT-PO3G improves the mechanical properties of the fiber, thereby increasing the fiber's breaking strength and resilience.

[0179] 3. The PTT-PO3G resin and fiber prepared by the two-step method have higher viscosity, strength and resilience than those prepared by the one-step method. This is because the terminal hydroxyl group of PO3G polyether has low reactivity, and its presence will affect the esterification reaction of PTA with diols and diamines.

[0180] The applicant declares that while the above-described embodiments illustrate the process of the present invention, the present invention is not limited to the above-described process steps, nor does it imply that the present invention must rely on the above-described process steps for implementation. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions for the raw materials used, additions of auxiliary ingredients, and selection of specific methods, etc., fall within the scope of protection and disclosure of the present invention.

Claims

1. A method for preparing a PTT-PO3G linear multi-block copolymer, characterized in that: The steps include: Step 1: Using terephthalic acid or terephthalate, 1,3-propylene glycol, and diamine as raw materials, a prepolymer is obtained through esterification and acylation reactions; Step 2: adding polytrimethylene ether glycol to the reaction system of step 1 to carry out polycondensation reaction to obtain a PTT-PO3G linear multi-block copolymer; The molar ratio of terephthalic acid or terephthalate, 1,3-propylene glycol, and diamine is 4:7.2-7.996:0.004-0.8; The weight of the polytrimethylene ether glycol is equivalent to 5 to 40 wt % of the total weight of terephthalic acid or terephthalate, 1,3-propylene glycol, diamine and polytrimethylene ether glycol.

2. The preparation method according to claim 1, characterized in that The molecular weight of the polytrimethylene ether glycol is 1000 to 3000 g / mol.

3. The preparation method according to claim 1, characterized in that The diamine is one or more of 1,6-hexanediamine, 1,10-decanediamine, and 1,12-diaminododecane; The terephthalate ester is dimethyl terephthalate or diethyl terephthalate.

4. The preparation method according to claim 1, characterized in that In both step 1 and step 2, a catalyst needs to be added; the catalyst is one or more combinations of n-butyl titanate, isopropyl titanate, tetraethyl titanate, zinc acetate, magnesium acetate, manganese acetate, antimony trioxide, and antimony glycolate; In step 2, a heat stabilizer is also required, and the heat stabilizer is one or more combinations of trimethyl phosphate, triphenyl phosphite, Irganox 1010, Irganox 168 and Irganox 245; The molar ratio of the catalyst to terephthalic acid or terephthalate used in step 1 is 0.25-1.5:1000; The molar ratio of the catalyst to terephthalic acid or terephthalate used in step 2 is 0.25-1.5:1000; The molar ratio of the heat stabilizer to terephthalic acid or terephthalate used in step 2 is 0.25-1.5:1000.

5. The preparation method according to claim 1, characterized in that The reaction pressure of step 1 is 1-2 bar, the reaction temperature is 190-240° C., and the reaction time is 1-2 h; In step 2, the reaction temperature is 190-240° C. for 1-2 hours, then raised to 250-260° C., while gradually reducing the pressure to below 100 Pa, and the reaction temperature is maintained for 2-5 hours.

6. A method for preparing an elastic fiber based on a PTT-PO3G linear multi-block copolymer, characterized in that: The PTT-PO3G linear multi-block copolymer prepared by the method according to any one of claims 1 to 5 is prepared into slices and dried in a drum oven and pre-crystallized, the pre-crystallization temperature is 100-120° C., the pre-crystallization time is 6-10 hours, and the moisture content of the slices after drying is less than 70 ppm; The elastic fiber can be obtained by melt spinning through a melt spinning machine.

7. The method for preparing elastic fiber according to claim 6, characterized in that: The melt spinning method comprises the following steps: drying and pre-crystallizing the slices into a melt by a twin-screw extruder, the melt is extruded into a spinning assembly, extruded from a spinneret, cooled by side blowing and a spinning tunnel, oiled by an oiling roller, and wound at high speed by a winder to obtain nascent fibers, which are then heat-set by a first drawing hot roller and a second drawing hot roller, and wound into filaments; The heating temperature of the twin-screw extruder is 230~240℃, the temperature of the spinning assembly is 235~250℃, the winding speed of the nascent fiber is 2000~3000m / min, the drafting ratio is 2~4 times, the temperature of the drafting hot roller 1 is 70~80℃, and the temperature of the drafting hot roller 2 is 100~110℃.

8. An elastic fiber, characterized in that: The method according to claim 6 or 7 is used for preparation.

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