CN103215685B - Preparation method of completely-biodegradable aliphatic copolyester monofilament - Google Patents

Abstract

The invention discloses a preparation method of completely biodegradable aliphatic copolyester monofilament, comprising the following steps: 1) preparing aliphatic copolyester melt: using succinic acid and ethylene glycol as raw materials, pentaerythritol as modified Add antimony-based catalysts to form a slurry in the beating tank; transport the above-mentioned slurry to the reactor continuously and stably for esterification reaction to obtain esterified products; then transport the above-mentioned esterified products by pumps Go to the polycondensation section for polycondensation to obtain aliphatic copolyester melt; 2) Preparation of aliphatic copolyester monofilament: pass the aliphatic copolyester melt prepared in step 1) through the melt conveying equipment, and measure, spray The filament is extruded, cooled and solidified in a cooling water tank, and then subjected to multi-stage stretching and heat setting to obtain a fully biodegradable aliphatic copolyester monofilament. The invention has the advantages of short process, low cost, stable melt quality and excellent spinning performance, and all physical indexes of the prepared monofilament can meet the use requirements.

Description

A kind of preparation method of completely biodegradable aliphatic copolyester monofilament

technical field

The present invention relates to a preparation method of fully biodegradable aliphatic copolyester monofilament, in particular to a preparation method of continuous polymerization and melt direct spinning fully biodegradable aliphatic copolyester monofilament, belonging to the field of chemical fibers .

Background technique

With the increasingly prominent environmental problems, biodegradable materials have attracted more and more attention from all over the world. The main chain of aliphatic polyester contains ester bonds that are easy to hydrolyze, and the main chain is flexible, and it is easy to degrade under the action of microorganisms through enzyme catalysis. As an environmentally friendly material, it has become a research and development hotspot worldwide. Among them, polylactic acid (PLA), polycaprolactone (PCL) and aliphatic dihydric alkyd polyester have been successfully industrialized, such as polybutylene succinate (PBS) as a typical biodegradable Aliphatic polyester is favored due to its excellent comprehensive performance and reasonable cost performance. It has developed rapidly in recent years. It is currently the biodegradable material with the most research and development at home and abroad, relatively mature technology and the largest industrialization scale. It is also the biodegradable material entering the market. One of the earliest varieties, mainly used in the production of packaging, film, agricultural, forestry and aquatic products, and civil engineering materials, etc., to achieve complete biodegradability and reduce environmental pollution. But at the same time, due to its high production cost and low melting point, the melt strength under high temperature spinning conditions is low, so the spinning performance is poor, which seriously hinders its application in the fiber field.

Polyethylene succinate (PES) polyester is a polymer of the same series as PBS polyester, and it is also a crystalline polymer. Its melting point is about 104°C, its glass transition temperature is about -12.5°C, and its crystallization speed is relatively fast. It has good thermal stability, is biodegradable, and has lower production costs than PBS. The synthesis of PES polyester has also been reported in relevant literature. For example, succinic anhydride and ethylene oxide are used as raw materials for ring-opening polymerization to obtain PES with a relatively high molecular weight. However, due to the high toxicity of ethylene oxide, it is easy to pollute the environment and endanger the health of operators. Very tightly controlled responses. Using decahydronaphthalene as a solvent, polyethylene succinate PES with a relatively high relative molecular weight was synthesized by solution polymerization, but the reaction speed of solution polymerization was slow, and the solvent recovery treatment was required, the production cost was high, and it was difficult to obtain practical application. In addition, it was reported that PES was synthesized by melt polycondensation, but the polycondensation reaction time was too long. Patent application number: 200810132792.2, patent name: a preparation method of polyethylene succinate, using succinic acid (SA) and ethylene glycol (EG) as raw materials, and preparing prepolymer by solution polymerization , and then obtain high-molecular-weight PES by chain extension, which is used for plastic production, but this method has the disadvantages of solvent recovery and long reaction time. Although the research on PES has just started at home and abroad, and no commercial products have been launched yet, PES is a kind of environmentally friendly polyester with great potential, no matter from the source of raw materials, or from the perspective of PES performance and cost. .

Therefore, to overcome the complex process flow, high production cost, difficult drying of slice crystallization, large molecular weight drop after remelting, low melt strength, and difficulty in meeting the processing requirements of high-speed spinning etc. in the preparation method of PES mentioned above The focus of invention breakthroughs.

content of the invention

The purpose of the present invention is to provide a preparation method of aliphatic copolyester monofilament that can be completely biodegradable, which has the advantages of short process, low cost, stable melt quality, excellent spinning performance, and various physical indicators of the obtained monofilament. All can meet the requirements of use, and the final product can be decomposed into carbon dioxide and water by microorganisms or enzymes in nature after being used and discarded. It is a completely biodegradable polymer material.

For achieving the above object, technical scheme of the present invention is:

A method for preparing a fully biodegradable aliphatic copolyester monofilament, comprising the following steps: 1) preparing an aliphatic copolyester melt: using succinic acid and ethylene glycol as raw materials, pentaerythritol as a modified monomer, And add an antimony-based catalyst, beat into a slurry in the beating tank; continuously and stably transport the above slurry to the reactor for esterification to obtain an esterified product; then use a pump to transport the above-mentioned esterified product to the polycondensation section for Polycondensation to obtain aliphatic copolyester melt; 2) Preparation of aliphatic copolyester monofilament: pass the aliphatic copolyester melt prepared in step 1) through the melt conveying equipment, and measure and extrude through the spinneret , cooled and solidified in a cooling water tank, and then multi-stage stretched and heat-set to obtain a fully biodegradable aliphatic copolyester monofilament.

The step 1) is specifically to use succinic acid and ethylene glycol as raw materials, pentaerythritol as a modified monomer, and add an antimony catalyst to make a slurry in a beating kettle; continuously and stably transport the above slurry to the ester In the Esterification-I reactor, the pressure is controlled at 0.12MPa, the temperature is 200.0°C, and the reaction time is 2.5 hours; then the materials after the reaction in the Esterification-I reactor are sent into the Esterification-II reactor, and stabilized agent, the temperature is controlled at 210°C, the reaction time is 0.5 hours, and the esterification rate is controlled at 97.0% to 98.5%; then the esterified product prepared above is pumped to the polycondensation section for polycondensation reaction, and the reaction temperature is 225 to 240 ℃, the degree of vacuum is 10-0.1KPa, the reaction time is less than 200min, and the aliphatic copolyester melt with the number average molecular weight greater than 50,000 is prepared.

In the step 1), the molar ratio of succinic acid to ethylene glycol is 1:1.05-1.25; the molar percentage of pentaerythritol and succinic acid is 0.1-0.3%; The molar percentage of diol is 5% solution; the weight percentage of the antimony-based catalyst and succinic acid is 500PPM; the weight percentage of the stabilizer and succinic acid is 200PPM.

The antimony-based catalyst in step 1) uses one of antimony ethylene glycol, antimony trioxide or antimony acetate (all provided by Jiangxi Eryuan Chemical Co., Ltd.); the stabilizer uses triphenyl phosphate (provided for Jiangxi Eryuan Chemical Co., Ltd.), phosphorous acid (provided for Jiangxi Eryuan Chemical Co., Ltd.), trimethyl phosphate (provided for Jiangxi Eryuan Chemical Co., Ltd.).

The antimony-based catalyst is preferably antimony glycol; the stabilizer is preferably triphenyl phosphate.

The temperature of the melt conveying pipeline in the step 2) is 200-210°C; the temperature of the spinning box is 220-240°C; the temperature of the cooling water is 10-30°C; the drawing temperature is 40-50°C; The temperature is 50-70° C.; the draw ratio is 4.5-5.5; the winding speed is 50-200 m/min; and the monofilament fineness of the prepared completely biodegradable aliphatic copolyester monofilament is 50-250 dtex.

The beneficial effect of the present invention is: the preparation method of a kind of fully biodegradable aliphatic copolyester monofilament provided by the present invention, in view of the deficiencies in the prior art, adopts melt polycondensation method, uses succinic acid and ethylene glycol as Raw material, pentaerythritol as modified monomer, antimony series as catalyst and phosphoric acid ester as stabilizer, high molecular weight PES copolyester is prepared on conventional continuous polyester equipment; then the synthesized copolyester is directly Through the melt conveying pipeline, it is metered, extruded through the spinneret, cooled and solidified in the cooling water tank, and then multi-stage stretched and heat-set to obtain a fully biodegradable aliphatic copolyester monofilament. The present invention has the following advantages: 1) By introducing pentaerythritol with tetrafunctionality, the shortcoming of too long reaction time for synthesizing PES by general melt polycondensation method is changed. Strength, improving the processability and fiber mechanical properties during high-speed spinning; 2) Using continuous polymerization to produce modified copolyester, further improving product quality and reducing production costs; 3) Using melt direct spinning to avoid Due to the low melting point of PES, the water is not easy to remove, resulting in the problem of too much viscosity drop during melt spinning, and the production cost is significantly reduced; 4) It has short process, low cost, stable melt quality, and excellent spinning performance. All physical indicators of the monofilament can meet the requirements of use, and the final product can be decomposed into carbon dioxide and water by microorganisms or enzymes in nature after being used and discarded. It is a completely biodegradable polymer material.

Detailed ways

Example 1

The preparation method of a completely biodegradable aliphatic copolyester monofilament referred to in this embodiment comprises the following steps: 1) preparing the aliphatic copolyester melt: on continuous polyester equipment, the molar ratio is 1: 1.25% of succinic acid and ethylene glycol, and the modified monomer pentaerythritol (pentaerythritol is formulated into a solution in which pentaerythritol accounts for 5% of the molar percentage of EG) with a molar percentage of succinic acid of 0.1 is added to the beating tank, and at the same time, the beating tank is added 500ppm (accounting for the weight percent of succinic acid) antimony-based catalyst ethylene glycol antimony is beaten into a slurry in the beating tank; the above-mentioned slurry is continuously and stably transported to the esterification-I reactor, and the pressure is controlled at 0.12MPa. The temperature is 200.0°C, and the reaction time is 2.5 hours; then the materials after the reaction in the esterification-I reactor are sent to the esterification-II reactor, and a stabilizer triphenyl phosphate accounting for 200PPM by weight of succinic acid is added , the control temperature is 210°C, the reaction time is 0.5 hours, and the esterification rate is controlled to be 97.8%; then the above-mentioned esterified product is transported to the polycondensation section by a pump for polycondensation reaction, the reaction temperature is 235-240°C, and the vacuum degree is 10-0.1KPa, the reaction time is 197min, and the aliphatic copolyester melt with the number average molecular weight greater than 50,000 is prepared. 2) Preparation of aliphatic copolyester monofilament: on the corresponding melt direct spinning filament production equipment, the aliphatic copolyester melt prepared in step 1) is passed through the melt conveying equipment, and is metered, spinneret Extrusion, cooling and solidification in the cooling water tank, and then multi-stage stretching and heat setting, the temperature of the melt conveying equipment (pipeline) is controlled at 200°C; the temperature of the spinning box is 220°C; the temperature of the cooling water is 30°C; The temperature is 40°C; the heat setting temperature is 50°C; the draft ratio is 4.5; the winding speed is 50m/min;

The intrinsic viscosity, melting point and number average molecular weight of the fully biodegradable aliphatic copolyester obtained by this embodiment are shown in Table 1; the spinning of the fully biodegradable aliphatic copolyester monofilament obtained by this embodiment See Table 2 for operational performance, breaking strength, and elongation at break.

Through the preparation method of a completely biodegradable aliphatic copolyester monofilament provided in this example, in view of the deficiencies in the prior art, the melt polycondensation method is adopted, with succinic acid and ethylene glycol as raw materials, and pentaerythritol as a modification Monomer, with antimony series as catalyst and phosphate ester as stabilizer, high molecular weight PES copolyester is prepared on conventional continuous polyester equipment; then the synthesized copolyester is directly passed through the melt conveying pipeline, After metering, spinneret extrusion, cooling and solidification in a cooling water tank, and then multi-stage stretching and heat setting, a completely biodegradable aliphatic copolyester monofilament is obtained. It has the following advantages: 1) By introducing pentaerythritol with tetrafunctionality, it has changed the shortcoming of too long reaction time for synthesis of PES by the general melt polycondensation method. Improve the processability and fiber mechanical properties during high-speed spinning; 2) The continuous polymerization method is used to produce modified copolyester, which further improves the quality of the product and reduces the production cost; 3) The direct spinning of the melt avoids the PES has a low melting point, and the moisture is not easy to remove, which causes the problem of too much viscosity drop during melt spinning, and the production cost is significantly reduced; 4) It has short process, low cost, stable melt quality, excellent spinning performance, and the obtained monofilament All physical indicators can meet the requirements of use. The final product can be decomposed into carbon dioxide and water by microorganisms or enzymes in nature after being used and discarded. It is a completely biodegradable polymer material.

Example 2

The preparation method of a completely biodegradable aliphatic copolyester monofilament referred to in this embodiment comprises the following steps: 1) preparing the aliphatic copolyester melt: on continuous polyester equipment, the molar ratio is 1: 1.15 succinic acid and ethylene glycol, the modified monomer pentaerythritol (pentaerythritol is formulated into a solution in which pentaerythritol accounts for 5% of the molar percentage of EG) accounting for 0.2% of the molar percentage of succinic acid is added to the beating tank, and at the same time Add 500ppm (accounting for the weight percentage of succinic acid) of antimony-based catalyst antimony trioxide, and make a slurry in the beating kettle; continuously and stably transport the above slurry to the esterification-I reactor, and control the pressure at 0.12MPa , the temperature is 200.0°C, and the reaction time is 2.5 hours; then the material after the reaction in the esterification-I reactor is sent into the esterification-II reactor, and the stabilizer phosphorous acid accounting for 200PPM of succinic acid weight percentage is added, The control temperature is 210°C, the reaction time is 0.5 hours, and the esterification rate is measured to be 98.1%. Then, the esterified product prepared above is pumped to the polycondensation section for polycondensation reaction. The reaction temperature is 230-235°C, and the vacuum degree is 10-0.1KPa, the reaction time is 185min, and the aliphatic copolyester melt with the number average molecular weight greater than 50,000 is prepared. 2) Preparation of aliphatic copolyester monofilament: on the corresponding melt direct spinning filament production equipment, the aliphatic copolyester melt prepared in step 1) is passed through the melt conveying equipment, and is metered, spinneret Extrusion, cooling and solidification in the cooling water tank, and then multi-stage stretching and heat setting, the temperature of the melt conveying equipment (pipeline) is controlled at 205°C; the temperature of the spinning box is 230°C; the temperature of the cooling water is 20°C; The temperature is 45°C; the heat setting temperature is 60°C; the draft ratio is 5.0; the winding speed is 125m/min;

The intrinsic viscosity, melting point and number average molecular weight of the fully biodegradable aliphatic copolyester obtained by this embodiment are shown in Table 1; the spinning of the fully biodegradable aliphatic copolyester monofilament obtained by this embodiment See Table 2 for operational performance, breaking strength, and elongation at break.

Through the preparation method of a completely biodegradable aliphatic copolyester monofilament provided in this example, in view of the deficiencies in the prior art, the melt polycondensation method is adopted, with succinic acid and ethylene glycol as raw materials, and pentaerythritol as a modification Monomer, with antimony series as catalyst and phosphate ester as stabilizer, high molecular weight PES copolyester is prepared on conventional continuous polyester equipment; then the synthesized copolyester is directly passed through the melt conveying pipeline, After metering, spinneret extrusion, cooling and solidification in a cooling water tank, and then multi-stage stretching and heat setting, a completely biodegradable aliphatic copolyester monofilament is obtained. It has the following advantages: 1) By introducing pentaerythritol with tetrafunctionality, it has changed the shortcoming of too long reaction time for synthesis of PES by the general melt polycondensation method. Improve the processability and fiber mechanical properties during high-speed spinning; 2) The continuous polymerization method is used to produce modified copolyester, which further improves the quality of the product and reduces the production cost; 3) The direct spinning of the melt avoids the PES has a low melting point, and the moisture is not easy to remove, which causes the problem of too much viscosity drop during melt spinning, and the production cost is significantly reduced; 4) It has short process, low cost, stable melt quality, excellent spinning performance, and the obtained monofilament All physical indicators can meet the requirements of use. The final product can be decomposed into carbon dioxide and water by microorganisms or enzymes in nature after being used and discarded. It is a completely biodegradable polymer material.

Example 3

The preparation method of a completely biodegradable aliphatic copolyester monofilament referred to in this embodiment comprises the following steps: 1) preparing the aliphatic copolyester melt: on continuous polyester equipment, the molar ratio is 1: 1.05 succinic acid and ethylene glycol, 0.3% of the molar percentage of succinic acid and modified monomer pentaerythritol (pentaerythritol is formulated into a solution in which pentaerythritol accounts for 5% of the molar percentage of EG) is added to the beating tank, and at the same time Add 500ppm (accounting for the weight percent of succinic acid) of antimony-based catalyst antimony acetate, and make a slurry in the beating kettle; continuously and stably transport the above slurry to the esterification-I reaction kettle, control the pressure at 0.12MPa, and the temperature The temperature is 200.0°C, and the reaction time is 2.5 hours; then the material after the reaction in the esterification-I reactor is sent into the esterification-II reactor, and a stabilizer trimethyl phosphate accounting for 200PPM by weight of succinic acid is added, The control temperature is 210°C, the reaction time is 0.5 hours, and the esterification rate is controlled to be 98.5%; then the esterified product prepared above is pumped to the polycondensation section for polycondensation reaction, the reaction temperature is 225-230°C, and the vacuum degree is 10 ~0.1KPa, the reaction time is 175min, and a completely biodegradable aliphatic copolyester melt with a number average molecular weight greater than 50,000 is prepared. 2) Preparation of aliphatic copolyester monofilament: on the corresponding melt direct spinning filament production equipment, the aliphatic copolyester melt prepared in step 1) is passed through the melt conveying equipment, and is metered, spinneret Extrusion, cooling and solidification in the cooling water tank, and then multi-stage stretching and heat setting, the temperature of the melt conveying equipment (pipeline) is controlled at 210°C; the temperature of the spinning box is 240°C; the temperature of the cooling water is 10°C; The temperature is 50°C; the heat setting temperature is 70°C; the draft ratio is 5.5; the winding speed is 200m/min;

The intrinsic viscosity, melting point and number average molecular weight of the fully biodegradable aliphatic copolyester obtained by this embodiment are shown in Table 1; the spinning of the fully biodegradable aliphatic copolyester monofilament obtained by this embodiment See Table 2 for operational performance, breaking strength, and elongation at break.

Through the preparation method of a completely biodegradable aliphatic copolyester monofilament provided in this example, in view of the deficiencies in the prior art, the melt polycondensation method is adopted, with succinic acid and ethylene glycol as raw materials, and pentaerythritol as a modification Monomer, with antimony series as catalyst and phosphate ester as stabilizer, high molecular weight PES copolyester is prepared on conventional continuous polyester equipment; then the synthesized copolyester is directly passed through the melt conveying pipeline, After metering, spinneret extrusion, cooling and solidification in a cooling water tank, and then multi-stage stretching and heat setting, a completely biodegradable aliphatic copolyester monofilament is obtained. It has the following advantages: 1) By introducing pentaerythritol with tetrafunctionality, it has changed the shortcoming of too long reaction time for synthesis of PES by the general melt polycondensation method. Improve the processability and fiber mechanical properties during high-speed spinning; 2) The continuous polymerization method is used to produce modified copolyester, which further improves the quality of the product and reduces the production cost; 3) The direct spinning of the melt avoids the PES has a low melting point, and the moisture is not easy to remove, which causes the problem of too much viscosity drop during melt spinning, and the production cost is significantly reduced; 4) It has short process, low cost, stable melt quality, excellent spinning performance, and the obtained monofilament All physical indicators can meet the requirements of use. The final product can be decomposed into carbon dioxide and water by microorganisms or enzymes in nature after being used and discarded. It is a completely biodegradable polymer material.

Comparative Example 1

1) Preparation of aliphatic copolyester melt: On the continuous polyester equipment, add succinic acid and ethylene glycol with a molar ratio of 1:1.25 into the beating kettle, and add 500ppm (accounting for succinic acid) into the beating kettle at the same time % by weight) antimony-based catalyst ethylene glycol antimony is beaten into a slurry in the beating tank; the above-mentioned slurry is continuously and stably transported to the esterification-I reactor, the control pressure is 0.12MPa, the temperature is 200.0°C, and the reaction time is It was 2.5 hours; then the material after the reaction in the esterification-I reactor was sent into the esterification-II reactor, and the stabilizer triphenyl phosphate accounting for 200PPM by weight of succinic acid was added, and the controlled temperature was 210°C. The reaction time is 0.5 hours, and the esterification rate is controlled to 97.8%; the above-mentioned esterified product is pumped to the polycondensation section for polycondensation reaction. It took 247min to obtain a completely biodegradable aliphatic copolyester. 2) Preparation of aliphatic copolyester monofilament: on the corresponding melt direct spinning filament production equipment, the aliphatic copolyester melt prepared in step 1) is passed through the melt conveying equipment, and is metered, spinneret Extrusion, cooling and solidification in the cooling water tank, and then multi-stage stretching and heat setting, the temperature of the melt conveying equipment (pipeline) is controlled at 200°C; the temperature of the spinning box is 220°C; the temperature of the cooling water is 30°C; The temperature is 40°C; the heat setting temperature is 50°C; the draft ratio is 4.5; the winding speed is 50m/min;

The intrinsic viscosity, melting point, and number average molecular weight of the fully biodegradable aliphatic copolyester obtained by this comparative example are shown in Table 1; The operating performance, breaking strength and elongation at break of silk are shown in Table 2.

Comparative Example 2

1) Preparation of aliphatic copolyester melt: On continuous polyester equipment, succinic acid and ethylene glycol with a molar ratio of 1:1.15, and a modified monomer pentaerythritol with a molar percentage of 0.2% of succinic acid (Pentaerythritol is formulated into a solution in which pentaerythritol accounts for 5% of the molar percentage of EG) into the beating kettle, and at the same time, 500ppm (accounting for succinic acid) antimony-based catalyst antimony trioxide is added to the beating kettle, and it is beaten into a beating kettle. Slurry: The above slurry is continuously and stably transported to the Esterification-I Reactor, the control pressure is 0.12MPa, the temperature is 200.0°C, and the reaction time is 2.5 hours; then the materials after the reaction in the Esterification-I Reactor are sent to Put it into the esterification-II reaction kettle, and add stabilizer phosphorous acid accounting for 200PPM of succinic acid weight percent, control temperature is 210 ℃, reaction time is 0.5 hour, and record esterification rate is 98.1%; The esterified product is pumped to the polycondensation section for polycondensation reaction. The reaction temperature is 230-235°C, the vacuum degree is 10-0.1KPa, and the reaction time is 185min. The aliphatic copolyester melt with a number average molecular weight of more than 50,000 is produced. . 2) The aliphatic copolyester melt obtained in step 1) is water-cooled and pelletized to obtain sliced particles, and then the slices are dried and melt-spun on a conventional slice spinning monofilament equipment; the slices are spun at 65°C Dry for 24 hours, spin box temperature is 230°C, cooling water temperature is 20°C; drawing temperature is 45°C; heat setting temperature is 60°C; drafting ratio is 5.0; winding speed is 125m/min; The monofilament fineness of the aliphatic copolyester monofilament is 150dtex.

In Comparative Example 2, because the drying conditions are not easy to control, the viscosity of the oil-free yarn drops to 0.647dl/g, the floating yarn increases during spinning, and the mechanical properties decrease.

The intrinsic viscosity, melting point, and number average molecular weight of the fully biodegradable aliphatic copolyester obtained by this comparative example are shown in Table 1; The operating performance, breaking strength and elongation at break of silk are shown in Table 2.

Embodiment 1-3 and comparative example 1, the mensuration of molecular weight in comparative example 1, 2 adopts gel chromatograph (GPC) of PL company, and chloroform is mobile phase, concentration is 0.3%, flow velocity 1ml/min, temperature 40 ℃, standard sample is narrow Distributed polystyrene. Intrinsic viscosity is tested with reference to GB/T14190-93 standard, using chloroform as solvent. The synthesis conditions and results of the aliphatic copolyester melt in Examples 1-3 and Comparative Examples 1 and 2 are shown in Table 1; in Examples 1-3 and Comparative Examples 1 and 2, the aliphatic copolymer can be completely biodegradable The preparation conditions and results of ester pre-oriented yarn (POY) filament (120dtex/48fPOY) are shown in Table 2.

As shown in Table 1, it can be seen from Examples 1 to 3 that the PES obtained by the present invention shortens the time of polycondensation reaction by adding pentaerythritol, improves production efficiency, and simultaneously obtains a higher molecular weight of PES; the comparison without adding pentaerythritol Embodiment 1, then the time of polycondensation reaction prolongs greatly, and the PES molecular weight that obtains is lower.

As shown in Table 2, it can be seen from Examples 1 to 3 that using the PES copolyesters obtained in Examples 1 to 3 in Table 1, the monofilaments obtained by melt direct spinning have excellent spinnability and fiber physical indicators. The difference between Comparative Example 1 and Example 1 is that no pentaerythritol is added during the preparation of PES copolyester, even if the melt direct spinning technology of Example 1 is compared by Table 2, it cannot satisfy post-processing and performance requirements well , poor spinnability and fiber physical indicators. The method for preparing PES copolyester in Comparative Example 2 is the same as in Example 2, and the monofilaments obtained by chip spinning later have poor spinnability and fiber physical indicators.

Table 1

Table 2

Claims (4)

1. oneplant the preparation method of completely-biodegradaliphatic aliphatic copolyester monofilament, it is characterized in that comprising the steps: 1) prepare aliphatic copolyester melt: with succinic acid and ethylene glycol for raw material, pentaerythrite is modified monomer, and adds antimony-based catalyst, in making beating still, break into slurry; Above-mentioned slurry continous-stable is delivered in reactor and carries out esterification and obtain carboxylate; Adopt transport pump to carry out polycondensation to polycondensation workshop section above-mentioned obtained carboxylate again and obtain aliphatic copolyester melt; 2) aliphatic copolyester monofilament is prepared: by aliphatic copolyester melt obtained for step 1) by melt Conveying equipment, through metering, spinning head extrudes, cooling curing in bosh, then through multistage stretching and HEAT SETTING, obtained completely-biodegradaliphatic aliphatic copolyester monofilament; Described step 1) is specially with succinic acid and ethylene glycol for raw material, and pentaerythrite is modified monomer, and adds antimony-based catalyst, in making beating still, break into slurry; Be delivered to by above-mentioned slurry continous-stable in esterification-I reactor, controlled pressure is 0.12MPa, and temperature is 200.0 DEG C, and the reaction time is 2.5 hours; Material after the reaction of esterification-I reactor being terminated again is sent in esterification-II reactor, and adds stabilizing agent, and control temperature is 210 DEG C, and the reaction time is 0.5 hour, and controlling esterification yield is 97.0% ~ 98.5%; Adopt transport pump to carry out polycondensation reaction to polycondensation workshop section above-mentioned obtained carboxylate again, reaction temperature is 225 ~ 240 DEG C, and vacuum is 10 ~ 0.1KPa, and the reaction time is less than 200min, the aliphatic copolyester melt that obtained number-average molecular weight is greater than 50,000; Described step 2) in the temperature of melt Conveying pipeline be 200 ~ 210 DEG C; Spinning body temperature is 220 ~ 240 DEG C; Cooling water temperature is 10 ~ 30 DEG C; Drawing temperature is 40 ~ 50 DEG C; Heat setting temperature is 50 ~ 70 DEG C; Drafting multiple is 4.5 ~ 5.5; Winding speed is 50 ~ 200 m/min; The filament number of obtained completely-biodegradaliphatic aliphatic copolyester monofilament is 50 ~ 250dtex.

2. the preparation method of a kind of completely-biodegradaliphatic aliphatic copolyester monofilament according to claim 1, is characterized in that the mol ratio of succinic acid and ethylene glycol in described step 1) is 1:1.05 ~ 1.25; Described pentaerythrite and the molar percentage of succinic acid are 0.1 ~ 0.3%; It is the solution of 5% that described pentaerythrite is made into the molar percentage that pentaerythrite accounts for ethylene glycol in advance; Described antimony-based catalyst and the percentage by weight of succinic acid are 500PPM; Described stabilizing agent and the percentage by weight of succinic acid are 200PPM.

3. the preparation method of a kind of completely-biodegradaliphatic aliphatic copolyester monofilament according to claim 1 and 2, is characterized in that in described step 1), antimony-based catalyst adopts the one in antimony glycol, antimonous oxide or antimony acetate; Described stabilizing agent adopts the one in triphenyl phosphate, phosphorous acid, trimethyl phosphate.

4. the preparation method of a kind of completely-biodegradaliphatic aliphatic copolyester monofilament according to claim 3, is characterized in that described antimony-based catalyst is antimony glycol; Described stabilizing agent is triphenyl phosphate.